the black and white of me

technological lessons from nature...

2009-03-21T13:55:00.001+08:00

Biomimetics: Design by Nature

What has fins like a whale, skin like a lizard, and eyes like a moth? The future of engineering.

By Tom Mueller

One cloudless midsummer day in February, Andrew Parker, an evolutionary biologist, knelt in the baking red sand of the Australian outback just south of Alice Springs and eased the right hind leg of a thorny devil into a dish of water. The maneuver was not as risky as it sounds: Though covered with sharp spines, the lizard stood only about an inch high at the shoulder, and it looked up at Parker apprehensively, like a baby dinosaur that had lost its mother. It seemed too cute for its harsh surroundings, home to an alarmingly high percentage of the world's most venomous snakes, including the inland taipan, which can kill a hundred people with an ounce of its venom, and the desert death adder, whose name pretty well says it all. Fierce too is the landscape itself, where the wind hissing through the mulga trees feels like a blow dryer on max, and the sun seems three times its size in temperate climes. Constant reminders that here, in the driest part of the world's driest inhabited continent, you'd better have a good plan for where your next drink is coming from.

This the thorny devil knows, with an elegance and certainty that fascinated Parker beyond all thought of snakebite or sunstroke. "Look, look!" he exclaimed. "Its back is completely drenched!" Sure enough, after 30 seconds, water from the dish had wicked up the lizard's leg and was glistening all over its prickly hide. In a few seconds more the water reached its mouth, and the lizard began to smack its jaws with evident satisfaction. It was, in essence, drinking through its foot. Given more time, the thorny devil can perform this same conjuring trick on a patch of damp sand—a vital competitive advantage in the desert. Parker had come here to discover precisely how it does this, not from purely biological interest, but with a concrete purpose in mind: to make a thorny-devil-inspired device that will help people collect lifesaving water in the desert.

A slender English academic with wavy, honey-blond hair beneath a wide-brimmed sun hat, Parker busied himself with eyedroppers, misters, and various colored powders, the better to understand the thorny devil's water-collecting alchemy. Now and then he made soft, bell-like, English-academic sounds of surprise and delight. "The water's spreading out incredibly fast!" he said, as drops from his eyedropper fell onto the lizard's back and vanished, like magic. "Its skin is far more hydrophobic than I thought. There may well be hidden capillaries, channeling the water into the mouth." After completing his last experiment, we gathered up his equipment and walked back to our Land Cruiser. The lizard watched us leave with a faint look of bereavement. "Seeing the devil in its natural environment was crucial to understanding the nature of its adaptations—the texture of the sand, the amount of shade, the quality of the light," Parker said as we drove back to camp. "We've done the macro work. Now I'm ready to look at the microstructure of its skin."

A research fellow at the Natural History Museum in London and at the University of Sydney, Parker is a leading proponent of biomimetics—applying designs from nature to solve problems in engineering, materials science, medicine, and other fields. He has investigated iridescence in butterflies and beetles and antireflective coatings in moth eyes—studies that have led to brighter screens for cellular phones and an anticounterfeiting technique so secret he can't say which company is behind it. He is working with Procter & Gamble and Yves Saint Laurent to make cosmetics that mimic the natural sheen of diatoms, and with the British Ministry of Defense to emulate their water-repellent properties. He even draws inspiration from nature's past: On the eye of a 45-million-year-old fly trapped in amber he saw in a museum in Warsaw, Poland, he noticed microscopic corrugations that reduced light reflection. They are now being built into solar panels.

Parker's work is only a small part of an increasingly vigorous, global biomimetics movement. Engineers in Bath, England, and West Chester, Pennsylvania, are pondering the bumps on the leading edges of humpback whale flukes to learn how to make airplane wings for more agile flight. In Berlin, Germany, the fingerlike primary feathers of raptors are inspiring engineers to develop wings that change shape aloft to reduce drag and increase fuel efficiency. Architects in Zimbabwe are studying how termites regulate temperature, humidity, and airflow in their mounds in order to build more comfortable buildings, while Japanese medical researchers are reducing the pain of an injection by using hypodermic needles edged with tiny serrations, like those on a mosquito's proboscis, minimizing nerve stimulation.

"Biomimetics brings in a whole different set of tools and ideas you wouldn't otherwise have," says materials scientist Michael Rubner of MIT, where biomimetics has entered the curriculum. "It's now built into our group culture."

Shortly after our trip to the Australian desert, I met up with Andrew Parker again, in London, to watch the next phase of his research into the thorny devil. Walking from the Natural History Museum's entrance to his laboratory on the sixth floor, we traversed warehouse-size halls filled with preserved organisms of the most exuberant variety. In one room were waist-high alcohol jars of grimacing sea otters, pythons, spiny echidnas, and wallabies, and one 65-foot-long case containing a giant squid. Other rooms held displays of gaudy hummingbirds, over-the-top toucans and majestic bowerbirds, and shelf after shelf filled with beetles as bright as gemstones: emerald-green scarabs, sapphire-blue Cyphogastras, and opalescent weevils.

To Parker this was not a mere collection of specimens, but "a treasure-trove of brilliant design." Every species, even those that have gone extinct, is a success story, optimized by millions of years of natural selection. Why not learn from what evolution has wrought? As we walked, Parker explained how the metallic sheen and dazzling colors of tropical birds and beetles derive not from pigments, but from optical features: neatly spaced microstructures that reflect specific wavelengths of light. Such structural color, fade-proof and more brilliant than pigment, is of great interest to people who manufacture paint, cosmetics, and those little holograms on credit cards. Toucan bills are a model of lightweight strength (they can crack nuts, yet are light enough not to seriously impede the bird's flight), while hedgehog spines and porcupine quills are marvels of structural economy and resilience. Spider silk is five times stronger by weight and vastly more ductile than high-grade steel. Insects offer an embarrassment of design riches. Glowworms produce a cool light with almost zero energy loss (a normal incandescent bulb wastes 98 percent of its energy as heat), and bombardier beetles have a high-efficiency combustion chamber in their posterior that shoots boiling-hot chemicals at would-be predators. TheMelanophila beetle, which lays its eggs in freshly burned wood, has evolved a structure that can detect the precise infrared radiation produced by a forest fire, allowing it to sense a blaze a hundred kilometers away. This talent is currently being explored by the United States Air Force.

"I could look through here and find 50 biomimetics projects in half an hour," Parker said. "I try not to walk here in the evening, because I end up getting carried away and working until midnight."

In one such late-night creative burst eight years ago, Parker decided to investigate the water-gathering skills of a desert beetle by building an enormous sand dune in his laboratory. This tenebrionid beetle flourishes in the Namib Desert in southwestern Africa, one of the world's hottest, driest environments. The beetle drinks by harvesting morning fogs, facing into the wind and hoisting its behind, where hydrophilic bumps capture the fog and cause it to coalesce into larger droplets, which then roll down the waxy, hydrophobic troughs between the bumps, reaching the beetle's mouth. Parker imported several dozen beetles from Namibia, which promptly scampered all over the lab when he opened the box, but eventually settled contentedly on the dune. There, using a hair dryer and various misters and spray bottles, Parker simulated the conditions in the Namib Desert well enough to understand the beetle's mechanism. He then replicated it on a microscope slide, using tiny glass beads for the bumps and wax for the troughs.

For all nature's sophistication, many of its clever devices are made from simple materials like keratin, calcium carbonate, and silica, which nature manipulates into structures of fantastic complexity, strength, and toughness. The abalone, for example, makes its shell out of calcium carbonate, the same stuff as soft chalk. Yet by coaxing this material into walls of staggered, nanoscale bricks through a subtle play of proteins, it creates an armor as tough as Kevlar —3,000 times harder than chalk. Understanding the microscale and nanoscale structures responsible for a living material's exceptional properties is critical to re-creating it synthetically. So today Andrew Parker had arranged to view the skin of a thorny devil museum specimen under a scanning electron microscope, hoping to find the hidden structures that allow it to absorb and channel water so effectively.

With a microscopist at the helm, we soared over the surface of the thorny devil's skin like a deep-space probe orbiting a distant planet, dipping down now and then at Parker's request to explore some curious feature of the terrain. There seemed to be little of interest in the Matterhornlike macrostructure of an individual thorn, though Parker speculated that it might wick away heat from the lizard's body or perhaps help capture the morning dew. Halfway down the thorn, however, he noticed a series of nodules set in rows, which seemed to grade down to a larger water-collection structure. Finally we dove into a crevasse at the base of the thorn and encountered a honeycomb-like field of indentations, each 25 microns across.

"Ah-ha!" Parker exclaimed, like Sherlock Holmes alighting upon a clue. "This is clearly a superhydrophobic surface for channeling water between the scales." A subsequent examination of the thorny devil's skin with an instrument called a micro-CT scanner confirmed his theory, revealing tiny capillaries between the scales evidently designed to guide water toward the lizard's mouth. "I think we've pretty well cracked the thorny devil structure," he said. "We're ready to make a prototype."

Enter the engineers. As the next phase in his quest to create a water-collection device inspired by the lizard, Parker sent his observations and experimental results to Michael Rubner and his MIT colleague Robert Cohen, a chemical engineer with whom he has worked on several biomimetics projects in the past. Rubner and Cohen are neatly groomed gentlemen who speak in clipped phrases and look frequently at their watches. While Parker likes to explain his work via a stroll through a botanic garden or by pulling out drawerfuls of bright beetles in a museum, they are more likely to draw a tidy graph of force over time, or flip through a PowerPoint presentation on their laptop. But a pooling of biological insight and engineering pragmatism is vital to success in biomimetics, and in the case of Parker, Cohen, and Rubner, it has led to several promising applications inspired by the Namib beetle and other insects. Using a robotic arm that, in a predetermined sequence, dips slides into a series of nanoparticle suspensions and other exotic ingredients, they have assembled materials layer by layer that have the same special properties as the organisms. Soon they hope to apply the method to create a synthetic surface inspired by thorny devil skin.

Though impressed by biological structures, Cohen and Rubner consider nature merely a starting point for innovation. "You don't have to reproduce a lizard skin to make a watercollection device, or a moth eye to make an antireflective coating," Cohen says. "The natural structure provides a clue to what is useful in a mechanism. But maybe you can do it better." Lessons from the thorny devil may enhance the water-collection technology they have developed based on the microstructure of the Namib beetle, which they're working to make into water-harvesting materials, graffiti-proof paints, and self-decontaminating surfaces for kitchens and hospitals. Or the work may take them in entirely new directions. Ultimately they consider a biomimetics project a success only if it has the potential to make a useful tool for people. "Looking at pretty structures in nature is not sufficient," says Cohen. "What I want to know is, Can we actually transform these structures into an embodiment with true utility in the real world?"

Which, of course, is the tricky bit. Potentially one of the most useful embodiments of natural design is the bio-inspired robot, which could be deployed in places where people would be too conspicuous, bored to tears, or killed. But such robots are notoriously difficult to build. Ronald Fearing, a professor of electrical engineering at the University of California, Berkeley, has taken on one of the biggest challenges of all: to create a miniature robotic fly that is swift, small, and maneuverable enough for use in surveillance or search-and-rescue operations.

If a blowfly had buzzed into Fearing's office when we first sat down on a warm March afternoon, the windows flung wide to the garden-like Berkeley campus, I would have swatted it away without a second thought. By the time Fearing finished explaining why he had chosen it as the model for his miniature aircraft, I would have fallen on bended knee in admiration. With wings beating 150 times per second, it hovers, soars, and dives with uncanny agility. From straight-line flight it can turn 90 degrees in under 50 milliseconds —a maneuver that would rip the Stealth fighter to shreds.

The key to making his micromechanical flying insect (MFI) work, Fearing said, isn't to attempt to copy the fly, but to isolate the structures crucial to its feats of flying, while keeping a sharp eye out for simpler—and perhaps better—ways to perform its highly complex operations. "The fly's wing is driven by 20 muscles, some of which only fire every fifth wing beat, and all you can do is wonder, What on Earth just happened there?" says Fearing. "Some things are just too mysterious and complicated to be able to replicate."

After CalTech neurobiologist Michael Dickinson used foot-long plastic wings flapping in two tons of mineral oil to demonstrate how the fly's U-shaped beat kept it aloft, Fearing whittled the complexity of the wing joint down to something he could manufacture. What he came up with resembles a tiny automobile differential; though lacking the fly's mystical 20-muscle poetry, it can still bang out U-shaped beats at high speed. To drive the wing, he needed piezoelectric actuators, which at high frequencies can generate more power than fly muscle can. Yet when he asked machinists to manufacture a ten-milligram actuator, he got blank stares. "People told me, 'Holy cow! I can do a ten-gram actuator,' which was bigger than our whole fly."

So Fearing made his own, one of which he held up with tweezers for me to see, a gossamer wand some 11 millimeters long and not much thicker than a cat's whisker. Fearing has been forced to manufacture many of the other minute components of his fly in the same way, using a micromachining laser and a rapid prototyping system that allows him to design his minuscule parts in a computer, automatically cut and cure them overnight, and assemble them by hand the next day under a microscope.

With the microlaser he cuts the fly's wings out of a two-micron polyester sheet so delicate that it crumples if you breathe on it and must be reinforced with carbon-fiber spars. The wings on his current model flap at 275 times per second—faster than the insect's own wings—and make the blowfly's signature buzz. "Carbon fiber outperforms fly chitin," he said, with a trace of self-satisfaction. He pointed out a protective plastic box on the lab bench, which contained the fly-bot itself, a delicate, origami-like framework of black carbon-fiber struts and hairlike wires that, not surprisingly, looks nothing like a real fly. A month later it achieved liftoff in a controlled flight on a boom. Fearing expects the fly-bot to hover in two or three years, and eventually to bank and dive with flylike virtuosity.

To find a biomimetic bot already up and running—or at least ambling—one need only cross the bay to Palo Alto. Ever since the fifth century B.C., when Aristotle marveled at how a gecko "can run up and down a tree in any way, even with the head downward," people have wondered how the lizard manages its gravity-defying locomotion. Two years ago Stanford University roboticist Mark Cutkosky set out to solve this age-old conundrum, with a gecko-inspired climber that he christened Stickybot.

In reality, gecko feet aren't sticky—they're dry and smooth to the touch—and owe their remarkable adhesion to some two billion spatula-tipped filaments per square centimeter on their toe pads, each filament only a hundred nanometers thick. These filaments are so small, in fact, that they interact at the molecular level with the surface on which the gecko walks, tapping into the low-level van der Waals forces generated by molecules' fleeting positive and negative charges, which pull any two adjacent objects together. To make the toe pads for Stickybot, Cutkosky and doctoral student Sangbae Kim, the robot's lead designer, produced a urethane fabric with tiny bristles that end in 30-micrometer points. Though not as flexible or adherent as the gecko itself, they hold the 500-gram robot on a vertical surface.

But adhesion, Cutkosky found, is only part of the gecko's game. In order to move swiftly—and geckos can scamper up a vertical surface at one meter per second—its feet must also unstick effortlessly and instantly. To understand how the lizard does this, Cutkosky sought the aid of biologists Bob Full, an expert in animal locomotion, and Kellar Autumn, probably the world's foremost authority on gecko adhesion. Through painstaking anatomical studies, force tests on individual gecko hairlets, and slow-motion analysis of lizards running on vertical treadmills, Full and Autumn discovered that gecko adhesion is highly directional: Its toes stick only when dragged downward, and they release when the direction of pull is reversed.

With this in mind, Cutkosky endowed his robot with seven-segmented toes that drag and release just like the lizard's, and a gecko-like stride that snugs it to the wall. He also crafted Stickybot's legs and feet with a process he calls shape deposition manufacturing (SDM), which combines a range of metals, polymers, and fabrics to create the same smooth gradation from stiff to flexible that is present in the lizard's limbs and absent in most man-made materials. SDM also allows him to embed actuators, sensors, and other specialized structures that make Stickybot climb better. Then he noticed in a paper on gecko anatomy that the lizard had branching tendons to distribute its weight evenly across the entire surface of its toes. Eureka. "When I saw that, I thought, Wow, that's great!" He subsequently embedded a branching polyester cloth "tendon" in his robot's limbs to distribute its load in the same way.

Stickybot now walks up vertical surfaces of glass, plastic, and glazed ceramic tile, though it will be some time before it can keep up with a gecko. For the moment it can walk only on smooth surfaces, at a mere four centimeters per second, a fraction of the speed of its biological role model. The dry adhesive on Stickybot's toes isn't self-cleaning like the lizard's either, so it rapidly clogs with dirt. "There are a lot of things about the gecko that we simply had to ignore," Cutkosky says. Still, a number of real-world applications are in the offing. The Department of Defense's Defense Advanced Research Projects Agency (DARPA), which funds the project, has it in mind for surveillance: an automaton that could slink up a building and perch there for hours or days, monitoring the terrain below. Cutkosky hypothesizes a range of civilian uses. "I'm trying to get robots to go places where they've never gone before," he told me. "I would like to see Stickybot have a real-world function, whether it's a toy or another application. Sure, it would be great if it eventually has a lifesaving or humanitarian role.…"

His voice trailed off, in a wistful, almost apologetic tone I had heard undercutting the optimism of several other biomimeticists. For all their differences in background, temperament, and ultimate aims, most practitioners conclude their enthusiastic discourses on their bio-inspired invention with a few halfhearted theories on how it may someday make its way into the real world. Often it sounds like wishful thinking.

For all the power of the biomimetics paradigm, and the brilliant people who practice it, bio-inspiration has led to surprisingly few mass-produced products and arguably only one household word—Velcro, which was invented in 1948 by Swiss chemist George de Mestral, by copying the way cockleburs clung to his dog's coat. In addition to Cutkosky's lab, five other high-powered research teams are currently trying to mimic gecko adhesion, and so far none has come close to matching the lizard's strong, directional, self-cleaning grip. Likewise, scientists have yet to meaningfully re-create the abalone nanostructure that accounts for the strength of its shell, and several well-funded biotech companies have gone bankrupt trying to make artificial spider silk. Why?

Some biomimeticists blame industry, whose short-term expectations about how soon a project should be completed and become profitable clash with the time-consuming nature of biomimetics research. Others lament the difficulty in coordinating joint work among diverse academic and industrial disciplines, which is required to understand natural structures and mimic what they do. But the main reason biomimetics hasn't yet come of age is that from an engineering standpoint, nature is famously, fabulously, wantonly complex. Evolution doesn't "design" a fly's wing or a lizard's foot by working toward a final goal, as an engineer would—it blindly cobbles together myriad random experiments over thousands of generations, resulting in wonderfully inelegant organisms whose goal is to stay alive long enough to produce the next generation and launch the next round of random experiments. To make the abalone's shell so hard, 15 different proteins perform a carefully choreographed dance that several teams of top scientists have yet to comprehend. The power of spider silk lies not just in the cocktail of proteins that it is composed of, but in the mysteries of the creature's spinnerets, where 600 spinning nozzles weave seven different kinds of silk into highly resilient configurations.

The multilayered character of much natural engineering makes it particularly difficult to penetrate and pluck apart. The gecko's feet work so well not just because of their billions of tiny nanohairs, but also because those hairs grow on larger hairs, which in turn grow on toe ridges that are part of bigger toe pads, and so on up to the centimeter scale, creating a seven-part hierarchy that maximizes the lizard's cling to all climbing surfaces. For the present, people cannot hope to reproduce such intricate nanopuzzles. Nature, however, assembles them effortlessly, molecule by molecule, following the recipe for complexity encoded in DNA. As engineer Mark Cutkosky says, "The price that we pay for complexity at small scales is vastly higher than the price nature pays."

Nonetheless the gap with nature is gradually closing. Researchers are using electron- and atomic-force microscopes, microtomography, and high-speed computers to peer ever deeper into nature's microscale and nanoscale secrets, and a growing array of advanced materials to mimic them more accurately than ever before. And even before biomimetics matures into a commercial industry, it has itself developed into a powerful new tool for understanding life. Berkeley animal locomotion expert Bob Full uses what he learns to build running, climbing, and crawling robots—and they in turn have taught him certain fundamental rules of animal movement. He has discovered, for example, that every land animal, from centipedes to kangaroos to humans, has precisely the same springiness in its legs and generates the same relative energy when it runs. Kellar Autumn, the gecko-adhesion specialist and a former student of Full's, regularly borrows bits of Cutkosky's Stickybot to compare them with the animal's natural structures and to test central assumptions about gecko biology that cannot be learned from the geckos themselves.

"It's no problem to apply a 0.2 Newton preload to a patch of gecko adhesive and drag it in a distal direction at one micron per second," Autumn says. "But try asking a gecko to do the same thing with its foot. It'll probably just bite you."

differentiation

2008-12-11T02:24:00.004+08:00

ok it's been awhile since i've actually blogged about something. so here it goes.

heh, don't let the title scare you. its not about math, its about us.

what separates man from animal? i mean, ultimately everyone with the slightest bit of trust in our biological field knows that the current theory is that ah meng's our long long long long long distance cousin. but so many of us are so certain that there's something different and special about us that separates us from animals. so what's our trait that differentiates us from animals?

is it intelligence? i don't think so. so far, we've trained dolphins to learn our language. we've taught gorillas sign language. we've taught dogs to specifically pick out drugs (how many of us can stand outside a random kitchen and tell us exactly what are the spices being used and what's being cooked now?). we've trained pigeons to pilot missiles (trust me on this, its true). we've even taught chimpanzees to send electronic signals to a mechanical arm to bring bananas to them. heck, we've taught WASPS to pick out bombs. so far, we've shown how we can use animals, but really, all it has successfully done is to show to every alien in the universe that all the animals here have a significant ability to learn. heck, put food in a bottle and screw the cap on. leave it with an octopus, and it will figure out that the cover opens by unscrewing it. can we do that? i mean we've SEEN people open bottle caps. octopuses haven't. do we possess such abilities? how bout learning what dolphins are saying? or knowing which bark means i'm hungry and which means "dammit, i have to sit again?" all we have done so far is to show that we know how to make other things more knowledgeable. but does that equate intelligence?

is it love? HA don't even get me started. which other freaking species have waged a 106 year war with its own because one thinks that their jesus is better than their enemy's jesus? which other species have created weapons SPECIFICALLY DESIGNED to kill their own kind? i mean honestly speaking, i don't think you can use a gattling gun for ANY other reason. and neither do i think F-16 falcons were designed to kill pigeons. wanna know what other animals exhibit monogamy? lovebirds are monogamous. heck, lets move into the reptile category. shingleback lizards are one such examples. they have only one partner and will always remain faithful to that partner, even after that partner has died. we're talking about reptiles here.

self awareness. right. some studies have shown that bees possess self awareness. yes there are specific tests to show that one possesses such traits, and yes, it is possible to test it on a bee. so, example of insect. Q.E.D, don't need to go further.

logical mind. heh. if logical mind= beyond animal, then a VAST majourity of humans on earth are no different from savage donkeys. i mean really, honestly, how many of you dare to even sit in a room with an aids patient? even at lower secondary level, where you already know that HIV is only transmittable via intimate body contact. how many would dare share a meal with one of them? logically, they are perfectly harmless, as long as you don't start acting out your fantasies with them. the number of people who smoke, who take drugs, who endulge in alcohol, all with full knowledge that they're just heavily investing in a suicide. "addiction" you say, then why even start?

it took years to let people realise that they do not have divine right to rule over other people. how much longer do we need to take before we can finally accept the fact that we have no rights over any thing on this earth? if we can never understand such a truth, we don't even possess any of the above mentioned traits, and are really no better than self centred, egoistic, weak monkeys.

ooh airheaded reptiles

2008-12-10T00:21:00.001+08:00

hmm.. so herbivorous dinosaurs might have been warm blooded...

ScienceDaily (Dec. 9, 2008) — Paleontologists have long known that dinosaurs had tiny brains, but they had no idea the beasts were such airheads.

A new study by Ohio University researchers Lawrence Witmer and Ryan Ridgely found that dinosaurs had more air cavities in their heads than expected. By using CT scans, the scientists were able to develop 3-D images of the dinosaur skulls that show a clearer picture of the physiology of the airways.

“I’ve been looking at sinuses for a long time, and indeed people would kid me about studying nothing—looking at the empty spaces in the skull. But what’s emerged is that these air spaces have certain properties and functions,” said Witmer, Chang Professor of Paleontology in Ohio University’s College of Osteopathic Medicine.

Witmer and Ridgely examined skulls from two predators, Tyrannosaurus rex and Majungasaurus, and two ankylosaurian dinosaurs, Panoplosaurus and Euoplocephalus, both plant eaters with armored bodies and short snouts. For comparison, the scientists also studied scans of crocodiles and ostriches, which are modern day relatives of dinosaurs, as well as humans.

The analysis of the predatory dinosaurs revealed large olfactory areas, an arching airway that went from the nostrils to the throat, and many sinuses—the same cavities that give us sinus headaches. Overall, the amount of air space was much greater than the brain cavity.

The CT scans also allowed Witmer and Ridgely to calculate the volume of the bone, air space, muscle and other soft tissues to make an accurate estimate of how much these heads weighed when the animals were alive. A fully fleshed-out T. rex head, for example, weighed more than 1,100 pounds.

“That’s more than the combined weight of the whole starting lineup of the Cleveland Cavaliers,” Witmer said.

Witmer suggests that the air spaces helped lighten the load of the head, making it about 18 percent lighter than it would have been without all the air. That savings in weight could have allowed the predators to put on more bone-crushing muscle or even to take larger prey.

These sinus cavities also may have played a biomechanical role by making the bones hollow, similar to the hollow beams used in construction — both are incredibly strong but don’t weigh as much their solid counterparts. A light but strong skull enabled these predators to move their heads more quickly and helped them hold their large heads up on cantilevered necks, explained Witmer, who published the findings in a recent issue of The Anatomical Record.

Though most researchers have assumed that the nasal passages in armored dinosaurs would mimic the simple airways of the predators, Witmer and Ridgely found that these spaces actually were convoluted and complex. The passages were twisted and corkscrewed in the beasts’ snouts and didn’t funnel directly to the lungs or air pockets.

“Not only do these guys have nasal cavities like crazy straws, they also have highly vascular snouts. The nasal passages run right next to large blood vessels, and so there’s the potential for heat transfer. As the animal breathes in, the air passed over the moist surfaces and cooled the blood, and the blood simultaneously warmed the inspired air,” said Witmer, whose research is funded by the National Science Foundation. “These are the same kinds of physiological mechanisms we find all the time in warm-blooded animals today.”

These twisty nasal passages also acted as resonating chambers that affected how the ankylosaurs vocalized. The complex airways would have been somewhat different in each animal and might have given the dinosaurs subtle differences in their voices.

“It’s possible that these armored dinosaurs could recognize individuals based on the voice,” said Witmer, who noted that his research team’s studies of the inner ear revealed a hearing organ that probably had the capability to discriminate these subtle vocal nuances.

Though Witmer found few similarities between the dinosaur and human sinuses—our brain cavities take up much more space relative to our sinuses— the scientist did find a resemblance between the air spaces of the crocodiles and ostriches and the ancient beasts under study.

“Extra air space turns out to be a family characteristic,” he said, “but the sinuses may be performing different roles in different species. Scientists have tended to focus on things such as bones and muscle, and ignored these air spaces. If we’re going to decipher the mysteries of these extinct animals, maybe we need to figure out just why it is that these guys were such airheads.”

http://www.sciencedaily.com/releases/2008/12/081209052145.htm

hypocrisy, another fact that we need to think about..

2008-12-03T16:36:00.002+08:00

i've been outdone.. but really, a nice article to ponder over. sometimes, the emotional us can lead us to our undoing.

The Truth about Hypocrisy

Charges of hypocrisy can be surprisingly irrelevant and often distract us from more important concerns

By Scott F. Aikin and Robert B. Talisse

Former U.S. vice president Al Gore urges us all to reduce our carbon footprint, yet he regularly flies in a private jet. Former drug czar William Bennett extols the importance of temperance but is reported to be a habitual gambler. Pastor Ted Haggard preached the virtues of “the clean life” until allegations of methamphetamine use and a taste for male prostitutes arose. Eliot Spitzer prosecuted prostitution rings as attorney general in New York State, but he was later found to be a regular client of one such ring.

These notorious accusations against public figures all involve hypocrisy, in which an individual fails to live according to the precepts he or she seeks to impose on others. Charges of hypocrisy are common in debates because they are highly effective: we feel compelled to reject the views of hypocrites. But although we see hypocrisy as a vice and a symptom of incompetence or insincerity, we should be exceedingly careful about letting our emotions color our judgments of substantive issues.

Allegations of hypocrisy are treacherous because they can function as argumentative diversions, drawing our attention away from the task of assessing the strength of a position and toward the character of the position’s advocate. Such accusations trigger emotional reflexes that dominate more rational thought patterns. And it is precisely in the difficult and important cases such as climate change that our reflexes are most often inadequate.

Thus, listeners should temper such knee-jerk reactions toward the messenger and instead independently consider the validity of the message itself. It also pays to examine closely what the duplicitous deeds really mean: from some vantage points, such behavior may actually support a hypocrite’s point of view, significantly softening the hypocrisy charge in those cases.

Undermining Authority
One surprising truth about hypocrisy is its irrelevance: the fact that someone is a hypocrite does not mean that his or her position on an issue is false. Environmentalists who litter do not by doing so disprove the claims of environmentalism. Politicians who publicly oppose illegal immigration but privately employ illegal immigrants do not thereby prove that contesting illegal immigration is wrong. Even if every animal-rights activist is exposed as a covert meat eater, it still might be wrong to eat meat.

More generally, just because a person does not have the fortitude to live up to his or her own standards does not mean that such standards are not laudable and worth trying to meet. It therefore seems that charges of hypocrisy prove nothing about a topic. Why, then, are they so potent?

The answer is that such allegations summon emotional, and often unconscious, reactions to the argument that undermine it. Such indictments usually serve as attacks on the authority of their targets. Once the clout of an advocate is weakened, the stage is set for dismissal of the proponent’s position. Consider the following two examples:

Dad: You shouldn’t smoke, son. It’s bad for your health, and it’s addictive.
Son: But, Dad! You smoke a pack a day!

Amy: Have you seen Al Gore’s An Inconvenient Truth? We need to reduce our carbon footprint right away.
Jim: Al Gore? You know he leaves a huge footprint with all his private jet flights!

In the first example, the son feels that his father is not an appropriate source of information on smoking because Dad is a hypocrite. The accusation of hypocrisy does not so much defeat Dad’s position as nullify it, almost as if Dad had never spoken. The same holds in the case of Gore’s airplane, although the speaker, Amy, is not the alleged hypocrite but rather Gore, the authority to which she appeals. In both cases, hypocrisy is proffered as evidence of the insincerity or incompetence of a source, providing ammunition for ignoring his or her advice or instruction.

Such ammunition is particularly potent because of the power of such personal portrayals. Once people have characterized someone in a negative light, they tend to ignore evidence to the contrary. In a 2007 study psychologists David N. Rapp of Northwestern University and Panayiota Kendeou of McGill University asked student volunteers to read 24 different stories involving a character who behaves in a way that suggests he is sloppy or lazy. Later in each story, however, the individual acts in a manner that contradicts this judgment. Nevertheless, less than half of the respondents revised their view of the character.

These results suggest that a first impression of someone as lazy or hypocritical actively inhibits the consideration of other information that might be important to understanding that person or the issue at hand. In the smoking and airplane examples, the son and Jim foolishly focus on the father’s and Gore’s hypocrisy rather than on the perils of smoking or the human contribution to global warming.

Duplicity Understood
In fact, if the son and Jim had focused on the issues, they might have viewed the father’s and Gore’s behavior radically differently. Consider what Dad’s smoking suggests: Dad believes smoking is bad for him, yet he continues to smoke because, of course, he is addicted. So Dad’s behavior—his hypocrisy—actually supports his point that smoking is addictive. Gore’s behavior also bolsters one of his arguments for change in national energy policy: that certain ingrained aspects of the American lifestyle, such as our penchant for driving SUVs and distaste for riding city buses, lead to environmental irresponsibility—even Gore cannot escape it. (To his credit, Gore compensates for his plane trips by buying carbon offsets, which pay for projects that reduce greenhouse gas emissions.)

Of course, hypocrisy does not always support the hypocrite’s view. Spitzer’s visits to prostitutes do nothing to reinforce his official opposition on prostitution. And in some cases, hypocrisy has precisely the significance that the son and Jim assign to it: it is reason enough to dismiss a source because the person has lost his credibility. For example, when the preacher who presents himself as a moral authority gets caught having an adulterous affair, his followers may rightly call his teachings into question.

Thus, hypocrisy is sometimes sufficient to undermine a person’s authority. It can warrant the thought, “Why pay attention to what he says?” But hypocrisy does not always have this effect, as the Dad and Gore cases show.

Whether hypocrisy is relevant to a person’s credibility usually depends on the content of the hypocrite’s statements. And yet hypocrisy charges, as they are popularly deployed, tend to short-circuit rational examination of that content. To skirt this danger, people should suppress their instinctual responses to accusations of duplicity so that they can focus on the real issues at hand. Such concentration is essential to our ability to rationally judge our leaders, colleagues and friends as well as to make decisions about important social issues that affect our lives.

ants-fungus-bacterium: 3 way mutualism. nature still surprises us.

2008-12-01T00:29:00.000+08:00

ScienceDaily (Nov. 30, 2008) — One of the most important developments in human civilisation was the practice of sustainable agriculture. But we were not the first - ants have been doing it for over 50 million years. Just as farming helped humans become a dominant species, it has also helped leaf-cutter ants become dominant herbivores, and one of the most successful social insects in nature.

According to an article in the November issue of Microbiology Today, leaf-cutter ants have developed a system to try and keep their gardens pest-free; an impressive feat which has evaded even human agriculturalists.

Leaf-cutter ants put their freshly-cut leaves in gardens where they grow a special fungus that they eat. New material is continuously incorporated into the gardens to grow the fungus and old material is removed by the ants and placed in special refuse dumps away from the colony. The ants have also adopted the practice of weeding. When a microbial pest is detected by worker ants, there is an immediate flurry of activity as ants begin to comb through the garden. When they find the pathogenic 'weeds', the ants pull them out and discard them into their refuse dumps.

"Since the ant gardens are maintained in soil chambers, they are routinely exposed to a number of potential pathogens that could infect and overtake a garden. In fact, many of the ant colonies do become overgrown by fungal pathogens, often killing the colony," said Professor Cameron Currie from the University of Wisconsin-Madison, USA. "Scientists have shown that a specialized microfungal pathogen attacks the gardens of the fungus-growing ants. These fungi directly attack and kill the crop fungus, and can overrun the garden in a similar fashion to the way weeds and pests can ruin human gardens."

A curious observation was that some worker ants had a white wax-like substance across their bodies. When they looked at it under a microscope scientists discovered that this covering was not a wax, but a bacterium! These bacteria are part of the group actinobacteria, which produce over 80% of the antibiotics used by humans. The bacteria produce antifungal compounds that stop the microfungal pathogen from attacking the garden. This discovery was the first clearly demonstrated example of an animal, other than humans, that uses bacteria to produce antibiotics to deal with pathogens.

"Research in our laboratory has revealed a number of interesting properties between the bacteria and the pathogenic fungus. The bacteria appear to be specially suited to inhibiting the pathogenic fungi that infect the ants' fungus garden," said Professor Currie.

The interaction between the ants and their fungus crop, and the ants and the bacteria is known as a mutualistic relationship. In general a mutualism is established when both members of the interaction benefit from the relationship. In the ant–fungus mutualism, the ants get food from the fungus. This mutualism is so tight that if the fungus is lost, the entire colony may die. In return, the fungus receives a continuous supply of growing material, protection from the environment, and protection from disease-causing pests.

So what do the bacteria get out of producing pesticides for the ants? "For starters, they get food. Many species of fungus-growing ants have evolved special crypts on their bodies where the bacteria live and grow. Scientists believe that the ants feed the bacteria through glands connected to these crypts," said Dr Garret Suen, a post-doctoral fellow in Professor Currie's lab. "Also, the bacteria get a protected environment in which to grow, away from the intense competition they would face if they lived in other environments such as the soil."

"Interestingly, the tight association between ant, bacteria and pathogen will sometimes result in the pathogen winning. This interplay has been described as a chemical 'arms race' between the bacteria and fungus, with one side beating the other as new compounds are evolved," said Professor Currie. "At the moment, we are beginning to understand the chemical warfare at the genetic level, and it is likely that these types of interactions are more prevalent in nature than previously thought."

So how exactly does an ant go about forming partnerships with a fungus and a bacterium? No one really knows. With new advances in molecular and genetic technologies, such as whole-genome sequencing, Professor Currie and Dr Suen hope to discover how these associations were established, and to understand how these interactions resulted in the remarkable fungus-growing ability of the ants.

if i had fingers that fast, i could pinch off flesh

2008-11-30T02:05:00.000+08:00

Panamanian Termite Goes Ballistic: Fastest Mandible Strike In The World

ScienceDaily (Nov. 29, 2008) — A single hit on the head by the termite Termes panamensis (Snyder), which possesses the fastest mandible strike ever recorded, is sufficient to kill a would-be nest invader, report Marc Seid and Jeremy Niven, post-doctoral fellows at the Smithsonian Tropical Research Institute and Rudolf Scheffrahn from the University of Florida.

Niven and Seid conducted the study at the Smithsonian's new neurobiology laboratory in Panama, established by a donation from the Frank Levinson Family Foundation. The laboratory was built to use Panama's abundant insect biodiversity to understand the evolution of brain miniaturization.

"Ultimately, we're interested in the evolution of termite soldiers' brains and how they employ different types of defensive weaponry," says Seid. Footage of the soldier termite's jaws as they strike an invader at almost 70 meters per second was captured on a high speed video camera in the laboratory at 40,000 frames per second. "Many insects move much faster than a human eye can see so we knew that we needed high speed cameras to capture their behavior, but we weren't expecting anything this fast. If you don't know about the behavior, you can't hope to understand the brain," Seid adds.

Why are the termites so fast? When insects become small they have difficulty generating forces that inflict damage. "To create a large impact force with a light object you need to reach very high velocities before impact," Niven explains.

The Panamanian termite's strike is the fastest mandible strike recorded, albeit over a very short distance. Because a termite soldier faces down its foe inside a narrow tunnel and has little room to parry and little time to waste, this death blow proves to be incredibly efficient.

The force for the blow is stored by deforming the jaws, which are held pressed against one another until the strike is triggered. This strategy of storing up energy from the muscles to produce fast movements is employed by locusts, trap-jaw ants and froghoppers. "The termites need to store energy to generate enough destructive force. They appear to store the energy in their mandibles but we still don't know how they do this—that's the next question," says Niven.

A full report of the study appears in the Nov. 25, 2008 issue of the journal Current Biology.

beetles with antibiotics

2008-11-30T02:04:00.000+08:00

yay, enough emoing, back to awesome articles

Some Beetles Can Quickly Neutralize Bacteria And Reduce Emergence Of Resistant Bacteria At Same Time

ScienceDaily (Nov. 29, 2008) — In less than an hour, the immune system of the beetle Tenebrio molitor neutralizes most of the bacteria infecting its hemolymph (the equivalent to blood in vertebrates); this is rendered possible by a cascade of ready-to-use cells and enzymes.

Bacteria that resist these "front-line" defenses are then dealt with by antimicrobial peptides – a sort of natural antibiotic – which halt their proliferation. A clearer understanding of these actors in insect immunity may make it possible to design treatments that prevent the development of drug resistance.

This has been shown in the results of a study carried out by the Equipe Ecologie Evolutive in the Laboratoire Biogéosciences (CNRS/Université de Bourgogne in Dijon), in collaboration with a British research group, and published in the journal Science.

Microorganisms have a considerable capacity for adaptation to the many strategies implemented to destroy them. Over the past 400 million or so years, the immune system of animals, and notably the relatively simpler system in insects, appears to have succeeded in preventing the evolution of microbial resistance. The secret to this achievement lies in a small toolbox of targeted natural antibiotics, the antimicrobial peptides.

In the present case, the researchers showed that the so-called "constitutive" front-line of cellular and enzymatic defenses in the insect immune system spares a small number of bacteria and thereby favors the development of microbial resistance. However, a second line of defenses involving antimicrobial peptides synthesized following the elimination of most bacteria by the front line, is able to restrict the growth of these surviving microorganisms, which may lead to their removal.

Thus the principal function of the antimicrobial peptides produced by the insect immune system is to prevent the resurgence of bacteria resistant to the host's constitutive defenses, which will consequently reduce the emergence of resistant bacteria.

is it worth it?

2008-11-29T01:33:00.002+08:00

Alright, it's time for some reflection I guess. For the past 4 years, I gave up opportunities, just so that I could help set up a culture for the school. I changed not only my decisions, but also my way of life and personality, to tell the school that I would be there to help them build up what they need to build up, and set down what is needed. In the first year, I accepted 3 leadership positions, sleeping less in 3 days than I usually sleep in a day, just to get things going.

Scouts: we started with nothing. Absolutely nothing. In a year, we changed 3 different teacher mentors. Only i was left to make sure that everything flowed smoothly. I personally trained my juniors, forcing myself to relearn things that I probably would never need in my life. This set the foundations of the present scout troop.

House: how many people knew I was the house captain of 2005? Most, even within Nobel itself, thought I was the vice captain. The shit I put in, staying up till 1am to call everyone down, not an easy job. At least i had the help of my co captain to do the showy stuff, which of course led everyone to think that I was a nobody. We got first in 2005, whatever the school said.

Council: pretty much my pride and joy. Joined in 2005 because i befriended the right people. But at least I was in. Met 3 friends, who with me, organised one of the best youth days in the history of our school. I will never forget them. watched council rise, fall, rise again, always with it. sat till 9pm to stock take council supplies. stayed till 10 to ensure that programmes went well. stressed over limited resources. never once complained about the lack of recognition. just because i was the least public centred of the lot.

now i look back, how much have i put in? how much could i have done to bring up my name? should i be as glory hunting as the others? i could do less, and still get more in return. anyway, this is how life works no?

my first team in council: yingzhen, yunzhi, nat. All three have been awesome in many ways. just take a closer look at the awards given out on the 1st of december. outstanding contribution. turns out ultimately, i still haven't done enough to stand out from the remaining 80% of the level. to the school, i'm still just a face in the crowd. just another one of the could be's. 80% of the level, at least a fifth of them never done a single thing for the school. i can't differentiate myself from them. pathetic. i could have rejected the responsibilites. i could have taken a backseat in council, scouts, house. would that make any difference in what the school is now? let someone else take the lead. i would have more time, more sleep, less pain, but no less recognition. because in terms of recognition, i have already hit rock bottom. perhaps, my grades might even have been better, i might even be able to break into the distinction category. oh look, MORE recognition for doing less.

School: please don't give me false hopes. "because of your contribution to the school, we have decided to put you as vice president for alumni" was that to pacify me? because i think it's failed. 5 students given the award of outstanding contribution. 60% of them NOT in the alumni. ms valedictarian: NOT in alumni. they contributed so much already. why not let THEM lead the alumni? honestly speaking. you just had to pick 4 people from the list of volunteers, and give reasons for why you chose them. please give honest answers. "we needed to find people. we rolled some dice. you came up" will do. i can take it. telling me something you don't believe in. that, i won't.

4 years of my time in NUS High School. 3 years, attention was directed only at the school's wellbeing. last year to try and save my own sorry ass from the depths of "just another face". looks like it wasn't enough. was it worth it?

a plastic brain. interesting.

2008-11-22T14:02:00.000+08:00

Forgotten But Not Gone: How The Brain Re-learns

ScienceDaily (Nov. 22, 2008) — Thanks to our ability to learn and to remember, we can perform tasks that other living things can not even dream of. However, we are only just beginning to get the gist of what really goes on in the brain when it learns or forgets something. What we do know is that changes in the contacts between nerve cells play an important role. But can these structural changes account for that well-known phenomenon that it is much easier to re-learn something that was forgotten than to learn something completely new?

Scientists at the Max Planck Institute of Neurobiology have been able to show that new cell contacts established during a learning process stay put, even when they are no longer required. The reactivation of this temporarily inactivated "stock of contacts" enables a faster learning of things forgotten.

While an insect still flings itself against the window-pane after dozens of unsuccessful attempts to gain its freedom, our brain is able to learn very complex associations and sequences of movement. This not only helps us to avoid accidents like walking into glass doors, but also enables us to acquire such diverse skills as riding a bicycle, skiing, speaking different languages or playing an instrument. Although a young brain learns more easily, we retain our ability to learn up to an advanced age. For a long time, scientists have been trying to ascertain exactly what happens in the brain while we learn or forget.

Flexible connections

To learn something, in other words, to successfully process new information, nerve cells make new connections with each other. When faced with an unprecedented piece of information, for which no processing pathway yet exists, filigree appendages begin to grow from the activated nerve cell towards its neighbours. Whenever a special point of contact, called synapse, forms at the end of the appendage, information can be transferred from one cell to the next - and new information is learned. Once the contact breaks down, we forget what we have learned.

The subtle difference between learning and relearning

Although learning and memory were recently shown to be linked to the changes in brain structure mentioned above, many questions still remain unanswered. What happens, for example, when the brain learns something, forgets it after a while and then has to learn it again later? By way of example, we know from experience that, once we have learned to ride a bicycle, we can easily pick it up again, even if we haven’t practiced for years. In other cases too, "relearning" tends to be easier than starting "from scratch". Does this subtle difference also have its origins in the structure of the nerve cells?

Cell appendages abide the saying "a bird in the hand …"

Scientists at the Max Planck Institute of Neurobiology have now managed to show that there are indeed considerable differences in the number of new cell contacts made - depending on whether a piece of information is new or is being learned second time around. Nerve cells that process visual information, for instance, produced a considerably higher number of new cell contacts if the flow of information from their "own" eye was temporarily blocked. After approximately five days, the nerve cells had rearranged themselves so as to receive and process information from the other eye - the brain had resigned itself to having only one eye at its disposal. Once information flowed freely again from the eye that had been temporarily closed, the nerve cells resumed their original function and now more or less ignored signals from the alternative eye.

"What surprised us most, however, was that the majority of the appendages which developed in response to the information blockade, continued to exist, despite the fact that the blockade was abolished ", project leader Mark Hübener explains. Everything seems to point to the fact that synapses are only disabled, but not physically removed. "Since an experience that has been made may occur again at a later point in time, the brain apparently opts to save a few appendages for a rainy day", Hübener continues. And true enough, when the same eye was later inactivated again, the nerve cells reorganized themselves much more quickly - because they could make use of the appendages that had stayed in place.

Useful reactivation

Many of the appendages that develop between nerve cells are thus maintained and facilitate later relearning. This insight is crucial to our understanding of the fundamental processes of learning and memory. And so, even after many years of abstinence, it should be no great problem if we want to have a go at skiing again this winter.

should probably stop getting surprised at what earth can offer.

2008-11-22T02:14:00.001+08:00

New Life Beneath Sea And Ice

ScienceDaily (Nov. 21, 2008) — Scientists have long known that life can exist in some very extreme environments. But Earth continues to surprise us.

At a European Science Foundation and COST (European Cooperation in the field of Scientific and Technical Research) 'Frontiers of Science' meeting in Sicily in October, scientists described apparently productive ecosystems in two places where life was not known before, under the Antarctic ice sheet, and above concentrated salt lakes beneath the Mediterranean. In both cases, innumerable tiny microbes are fixing or holding onto quantities of organic carbon large enough to be significant in the global carbon cycle.

Lakes under the ice

Brent Christner of Louisiana State University, in the US, told the conference about the microbes living within and beneath the ice on Antarctica. In the last decade, scientists have discovered lakes of liquid water underneath the Antarctic ice sheet. So far we know of about 150 lakes, but this number will probably increase when the entire continent has been surveyed. These lakes occur as a result of geothermal heat trapped by the thick ice, melting it from underneath, and the great pressure from the ice above, which lowers the melting point of water.

The largest subglacial lake, Lake Vostok, lies beneath the coldest place on the planet, where the temperature at the surface often falls below minus 60 degrees Celsius. "It's the sixth largest freshwater lake on the planet by volume, and about the size of Lake Ontario," says Christner. "If you were on a boat in the middle of the lake, you would not see shores."

Christner has examined microbial life in ice cores from Vostok and many other global locations. While direct samples of water from subglacial Antarctic lakes have yet to be obtained, the lower 80m or so of the Vostok ice core represents lake water that progressively freezes onto the base as the ice sheet slowly traverses the lake. "Microbial cell and organic carbon concentrations in this accreted ice are significantly higher than those in the overlying ice, which implies that the subglacial environment is the source," says Christner.

Based on accumulating measurements of microbes in the subglacial environment, he calculates that the concentration of cell and organic carbon in the Earth's ice sheets, or 'cryosphere', may be hundreds of times higher than what is found in all the planet's freshwater systems. "Glacial ice is not currently considered as a reservoir for organic carbon and biology," says Christner, "but that view has to change."

Salt below the sea

Beneath the Mediterranean lurks a similar surprise. Michail Yakimov of the Institute of the Coastal Marine Environment, Messina, Italy is a project leader for the European Science Foundation's EuroDEEP programme on ecosystem functions and biodiversity in the deep sea. His team studies lakes of concentrated salt solution, known as anoxic hypersaline basins, on the floor of the Mediterranean. They have discovered extremely diverse microbial communities on the surfaces of such lakes.

The anoxic basins, so called because they are devoid of oxygen, occur below 3,000 m beneath the surface and are five to ten times more saline than seawater. One theory says they exist uniquely in the Mediterranean, because this sea entirely evaporated after it was cut off from the Atlantic around 250 million years ago. Its salt became a layer of rock salt, called evaporite, which was then buried by windblown sediment. Now the sea is filled again, the salt layer has been exposed in some places, perhaps by small seaquakes, and the salts from the ancient Mediterranean have dissolved again, making the water very salty.

Despite the harsh conditions, hypersaline brines have been shown to possess a wide range of active microbial communities. Together with other international partners, Yakimov's team has already identified more than ten new lineages of bacteria and archaea (these are ancient bacteria-like organisms), which they have named the Mediterranean Sea Brine Lake Divisions.

There is ample life at the boundary between the concentrated basin and the ordinary seawater. "Because of the very high density of the brine, it does not mix with seawater," he explains, "and there is a sharp interface, about 1m thick."

In that layer, microbial diversity is incredibly rich. The research shows that these microbes largely live by sulphide oxidation. Like the communities at hydrothermal vents in the deep ocean, they can survive independently of sunlight and oxygen. But they are an important store for organic carbon. "The deep-sea microbial communities in the Mediterranean fix as much or even more carbon dioxide each year as those in the surface layers," says Yakimov. "This carbon sink should be taken into account at the global scale."

This research was presented at the "Complex Systems: Water and Life" Frontiers of Science conference, organized by European Science Foundation and COST, 29-31 October, Taormina, Sicily.

fatal to dawin theory? creationists, take that!

2008-11-21T00:22:00.000+08:00

Darwin Was Right About How Evolution Can Affect Whole Group

ScienceDaily (Nov. 20, 2008) — Worker ants of the world, unite! You have nothing to lose but your fertility. The highly specialized worker castes in ants represent the pinnacle of social organization in the insect world. As in any society, however, ant colonies are filled with internal strife and conflict. So what binds them together? More than 150 years ago, Charles Darwin had an idea and now he's been proven right.

Evolutionary biologists at McGill University have discovered molecular signals that can maintain social harmony in ants by putting constraints on their fertility. Dr. Ehab Abouheif, of McGill's Department of Biology, and post-doctoral researcher, Dr. Abderrahman Khila, have discovered how evolution has tinkered with the genes of colonizing insects like ants to keep them from fighting amongst themselves over who gets to reproduce.

"We've discovered a really elegant developmental mechanism, which we call 'reproductive constraint,' that challenges the classic paradigm that behaviour, such as policing, is the only way to enforce harmony and squash selfish behaviour in ant societies," said Abouheif, McGill's Canada Research Chair in Evolutionary Developmental Biology.

Reproductive constraint comes into play in these ant societies when evolutionary forces begin to work in a group context rather than on individuals, the researchers said. The process can be seen in the differences between advanced ant species and their more primitive cousins. The study was published in the Nov. 18 edition of the Proceedings of the National Academy of Sciences.

Ants – organized in colonies around one or many queens surrounded by their specialized female workers – are classic examples of what are called eusocial organisms.

"More primitive, or ancestral, ants tend to have smaller colony sizes and have much higher levels of conflict over reproduction than the more advanced species," Abouheif explained. "That's because the workers have a much higher reproductive capacity and there is conflict with the queen to produce offspring."

To their surprise, Khila and Abouheif discovered that "evolution has tinkered with the molecular signals that are used by the egg to determine what's going to be the head and what's going to be the tail, to stop the worker ants from producing viable offspring," Abouheif explained. "Different species of ants have different levels of this "reproductive constraint," and we believe those levels provide a measure of how eusocial the colony is. The less the workers reproduce, the more coherent the group becomes."

The existence of sterile castes of ants tormented Charles Darwin as he was formulating his Theory of Natural Selection, and he described them as the "one special difficulty, which at first appeared to me insuperable, and actually fatal to my theory." If adaptive evolution unfolds by differential survival of individuals, how can individuals incapable of passing on their genes possibly evolve and persist?

Darwin proposed that in the case of ant societies natural selection applies not only to the individual, because the individual would never benefit by cutting its own reproduction, but also to the family or group. This study supports Darwin's prescient ideas, and provides a molecular measure of how an entire colony can be viewed as a single or "superorganism."

2008-11-18T00:57:00.003+08:00

philosophy can eat shit today. i'm blogging about this.

i'm starting to get pissed. i mean, what's wrong with courts? they tell me the comp is nice, i pay 1.6k for it, they send me the wrong comp, take another 2 weeks to get it right, decide to come over to add the ram later, effectively destroying the acer warrantee, while looking like freaking beginners while adding it.

NOW, with no acer warrantee, but only with courts warrantee, my comp starts screwing up with the stupid flickering screen, which doesn't happen when i put it on my 4 year old comp, and then my comp starts blue screening for starting up windows, i send it over to courts, and they tell me my comp is fine? after handling it myself (means the goodness knows how much paid for the 3 year courts warrantee is pointless), i get it to normal. and now it's still crashing on me. for? using google chrome. for? using msn. software problem? no. i reformatted it, deleting all my beautiful saved games and anime cos it crashes when i try to back THAT up.

what's the freaking problem with courts man? give me lousy shit, then tell me the shit's strawberries? you think i'm a 2 year old pooper? i know shit when i get smacked in the face with it. should have realised it was shit when i saw it from 2 miles off.

catalytic power of emzymes

2008-11-11T21:45:00.000+08:00

Without Enzyme, Biological Reaction Essential To Life Takes 2.3 Billion Years

ScienceDaily (Nov. 11, 2008) — All biological reactions within human cells depend on enzymes. Their power as catalysts enables biological reactions to occur usually in milliseconds. But how slowly would these reactions proceed spontaneously, in the absence of enzymes – minutes, hours, days? And why even pose the question?

One scientist who studies these issues is Richard Wolfenden, Ph.D., Alumni Distinguished Professor Biochemistry and Biophysics and Chemistry at the University of North Carolina at Chapel Hill. Wolfenden holds posts in both the School of Medicine and in the College of Arts and Sciences and is a member of the National Academy of Sciences.

In 1995, Wolfenden reported that without a particular enzyme, a biological transformation he deemed "absolutely essential" in creating the building blocks of DNA and RNA would take 78 million years.

"Now we've found a reaction that – again, in the absence of an enzyme – is almost 30 times slower than that," Wolfenden said. "Its half-life – the time it takes for half the substance to be consumed – is 2.3 billion years, about half the age of the Earth. Enzymes can make that reaction happen in milliseconds."

With co-author Charles A. Lewis, Ph.D., a postdoctoral scientist in his lab, Wolfenden published a report of their new findings recently in the online early edition of the Proceedings of the National Academy of Science. The study is also due to appear in the Nov. 11 print edition.

The reaction in question is essential for the biosynthesis of hemoglobin and chlorophyll, Wolfenden noted. But when catalyzed by the enzyme uroporphyrinogen decarboxylase, the rate of chlorophyll and hemoglobin production in cells "is increased by a staggering factor, one that's equivalent to the difference between the diameter of a bacterial cell and the distance from the Earth to the sun."

"This enzyme is essential for both plant and animal life on the planet," Wolfenden said. "What we're defining here is what evolution had to overcome, that the enzyme is surmounting a tremendous obstacle, a reaction half-life of 2.3 billion years."

Knowing how long reactions would take without enzymes allows biologists to appreciate their evolution as prolific catalysts, Wolfenden said. It also enables scientists to compare enzymes with artificial catalysts produced in the laboratory.

"Without catalysts, there would be no life at all, from microbes to humans," he said. "It makes you wonder how natural selection operated in such a way as to produce a protein that got off the ground as a primitive catalyst for such an extraordinarily slow reaction."

Experimental methods for observing very slow reactions can also generate important information for rational drug design based on cellular molecular studies.

"Enzymes that do a prodigious job of catalysis are, hands-down, the most sensitive targets for drug development," Wolfenden said. "The enzymes we study are fascinating because they exceed all other known enzymes in their power as catalysts."

Wolfenden has carried out extensive research on enzyme mechanisms and water affinities of biological compound. His work has also influenced rational drug design, and findings from his laboratory helped spur development of ACE inhibitor drugs, now widely used to treat hypertension and stroke. Research on enzymes as proficient catalysts also led to the design of protease inhibitors that are used to treat HIV infection.

"We've only begun to understand how to speed up reactions with chemical catalysts, and no one has even come within shouting distance of producing, or predicting the magnitude of, their catalytic power," Wolfenden said.

Support for this research came from the National Institute of General Medicine, a component of the National Institutes of Health.

another you

2008-11-11T01:19:00.001+08:00

this is a nice song... ^^

Female models and male self consciousness

2008-11-08T01:26:00.001+08:00

Surprisingly, Female Models Have Negative Effect On Men

ScienceDaily (Nov. 7, 2008) — Many studies have shown that media images of female models have had a negative impact on how woman view their own bodies, but does this same effect hold true when men view male models? A leading researcher of media effects on body image at the University of Missouri looked at the effect of male magazines on college-age men.

Completing three different studies, Jennifer Aubrey, assistant professor of communication in the College of Arts and Science, found that unlike their female classmates, it was not the same-sex models that affected the males negatively, but quite the opposite.

In her research, which will be published in Human Communication Research, Aubrey found that the cultural expectation for men is not that they have to be as attractive as their peers, but that they need to be attractive enough to be sexually appealing to women.

In her first study, Aubrey measured male exposure to 'lad' magazines, such as Maxim, FHM and Stuff, which she observes contains two main messages: the visual, which mostly contain sexually suggestive images of women; and textual, which contain articles that speak in a bawdy, male voice about topics including fashion, sex, technology and pop culture. Aubrey also measured male body self-consciousness (a participant's awareness and tendency to monitor one's appearance) and appearance anxiety (the anticipation of threatening stimuli). Participants were asked questions such as "During the day, I think about how I look," and then asked the same questions a year later.

"We found that reading lad magazines was related to having body self-consciousness a year later," said Aubrey. "This was surprising because if you look at the cover of these magazines, they are mainly images of women. We wondered why magazines that were dominated by sexual images of women were having an effect of men's feelings about their own bodies."

To help answer this question, Aubrey collaborated with University of California-Davis Assistant Professor Laramie Taylor. The researchers divided male study participants into three groups. Group one examined layouts from lad magazines that featured objectified women along with a brief description of their appearances. The second group viewed layouts about male fashion, featuring fit and well-dressed male models. The final group inspected appearance-neutral layouts that featured topics including technology and film trivia.

"Men who viewed the layouts of objectified females reported more body self-consciousness than the other two groups," Aubrey said. "Even more surprising was that the male fashion group reported the least amount of body self-consciousness among the three groups."

Aubrey speculated that the exposure to objectified females increased self-consciousness because men are reminded that in order to be sexually or romantically involved with a woman of similar attractiveness, they need to conform to strict appearance standards.

To test her theory, Aubrey and Taylor completed a third study that involved breaking men into two groups. Group one received lad magazine layouts of sexually idealized females and group two received the same layouts with average-looking 'boyfriends' added to the photos, with captions about how the female models are attracted to the average-looking men.

"We found that the men who view the ads with the average-looking boyfriend in the picture reported less body self-consciousness than the men who saw the ads with just the model," Aubrey said. "When the men felt that the model in the ad liked average-looking guys, it took the pressure off of them and made them less self-conscious about their own bodies."

Sexy red one, male brain zero

2008-10-29T00:41:00.001+08:00

Now I have even less to say when someone tells me men think only with the trouser titan.

Red Enhances Men's Attraction To Women, Psychological Study Reveals

Psychologist Daniel Niesta holding one of the images used in the study. Participants were asked questions including: "Imagine that you are going on a date with this person and have $100 in your wallet. How much money would you be willing to spend on your date?"' (Credit: Image courtesy of University of Rochester)

ScienceDaily (Oct. 28, 2008) — A groundbreaking study by two University of Rochester psychologists to be published online Oct. 28 by the Journal of Personality and Social Psychology adds color—literally and figuratively—to the age-old question of what attracts men to women.

Through five psychological experiments, Andrew Elliot, professor of psychology, and Daniela Niesta, post-doctoral researcher, demonstrate that the color red makes men feel more amorous toward women. And men are unaware of the role the color plays in their attraction.

The research provides the first empirical support for society's enduring love affair with red. From the red ochre used in ancient rituals to today's red-light districts and red hearts on Valentine's Day, the rosy hue has been tied to carnal passions and romantic love across cultures and millennia. But this study, said Elliot, is the only work to scientifically document the effects of color on behavior in the context of relationships.

"It's only recently that psychologists and researchers in other disciplines have been looking closely and systematically at the relationship between color and behavior. Much is known about color physics and color physiology, but very little about color psychology," said Elliot. "It's fascinating to find that something as ubiquitous as color can be having an effect on our behavior without our awareness."

Although this aphrodisiacal effect of red may be a product of societal conditioning alone, the authors argue that men's response to red more likely stems from deeper biological roots. Research has shown that nonhuman male primates are particularly attracted to females displaying red. Female baboons and chimpanzees, for example, redden conspicuously when nearing ovulation, sending a clear sexual signal designed to attract males.

"Our research demonstrates a parallel in the way that human and nonhuman male primates respond to red," concluded the authors. "In doing so, our findings confirm what many women have long suspected and claimed – that men act like animals in the sexual realm. As much as men might like to think that they respond to women in a thoughtful, sophisticated manner, it appears that at least to some degree, their preferences and predilections are, in a word, primitive."

To quantify the red effect, the study looked at men's responses to photographs of women under a variety of color presentations. In one experiment, test subjects looked at a woman's photo framed by a border of either red or white and answered a series of questions, such as: "How pretty do you think this person is?" Other experiments contrasted red with gray, green, or blue.

When using chromatic colors like green and blue, the colors were precisely equated in saturation and brightness levels, explained Niesta. "That way the test results could not be attributed to differences other than hue."

In the final study, the shirt of the woman in the photograph, instead of the background, was digitally colored red or blue. In this experiment, men were queried not only about their attraction to the woman, but their intentions regarding dating. One question asked: "Imagine that you are going on a date with this person and have $100 in your wallet. How much money would you be willing to spend on your date?"

Under all of the conditions, the women shown framed by or wearing red were rated significantly more attractive and sexually desirable by men than the exact same women shown with other colors. When wearing red, the woman was also more likely to score an invitation to the prom and to be treated to a more expensive outing.

The red effect extends only to males and only to perceptions of attractiveness. Red did not increase attractiveness ratings for females rating other females and red did not change how men rated the women in the photographs in terms of likability, intelligence or kindness.

Although red enhances positive feelings in this study, earlier research suggests the meaning of a color depends on its context. For example, Elliot and others have shown that seeing red in competition situations, such as written examinations or sporting events, leads to worse performance.

The current findings have clear implications for the dating game, the fashion industry, product design and marketing.

http://www.sciencedaily.com/releases/2008/10/081028074323.htm

more ironies: skin moisturizing cream makes skins dryer

2008-10-24T11:48:00.002+08:00

hmm, expected i guess? just like taking medicine, or painkillers, the more you take, the less your body is adapted to it.

Skin Creams Can Make Skin Drier

ScienceDaily (Oct. 23, 2008) — Many people have noticed that as soon as you start using a skin cream, you have to continue with it; if you stop lubricating, your skin becomes drier than when you started. And now there is research to confirm for the first time that normal skin can become drier from creams.

Izabela Buraczewska presents these findings in the dissertation she is publicly defending at Uppsala University in Sweden on October 24.

The findings in Izabela Buraczewska’s dissertation confirm what many have suspected: creams can make the skin drier. She has studied what happens in the skin at the molecular level and also what positive and negative effects creams have on the skin. Her research shows that differences in the pH of creams do not seem to play any role.

Different oils were also studied in a seven-week treatment period, but no difference was established between mineral oil and a vegetable oil. Both oils resulted in the skin being less able to cope with external stresses. Treatment with a more complex cream compound, however, resulted in more resistant skin with no signs of dryness.

Tissues samples taken from the treated skin areas also show that the weakening of the skin’s protective barrier can be tied to changes in the activity of certain genes involved in producing skin fats, among other functions. The conclusion is that the contents of creams impact these effects on the skin. This knowledge enhances our potential to develop creams that reinforce the skin’s protective barrier in a positive way, without making the skin drier. Such creams would mean that various groups of patients with dry skin, for example eczema and ichthyosis, could enjoy a better quality of life.

“My findings show that creams differ and that knowledge of the effect of various ingredients is important for us to be able to tailor the treatment to various skin types,” says Izabela Buraczewska.

Vetenskapsrådet (The Swedish Research Council) (2008, October 23). Skin Creams Can Make Skin Drier. ScienceDaily. Retrieved October 24, 2008, from http://www.sciencedaily.com /releases/2008/10/081022101500.htm

twitter?

2008-10-21T21:45:00.002+08:00

right, was in a state of "I'M BLOODY PISSED WITH THE SCHOOL EMAIL FOR MAKING ME CLICK 700 TIMES JUST TO DELETE MY INBOX" when i decided these kinds of rants shouldn't go on my blog since its so "high and mighty and so educational" and stuff. technically this shouldn't even be here -.-

alright.. stuff like this shall go on my twitter instead. XD

ok. since this IS supposed to be educational, i'll just throw in a couple of food for thought.

these giant magnets are smaller than i thought... =/

Ancient microbes made giant magnets

Magnetic fossils show how climate change creates new extremes.

Ashley Yeager

Scientists have unearthed giant magnetic fossils, the remnants of microbes buried in 55-million-year-old sediment. The growth of these unusual structures during a period of massive global warming provides clues about how climate change might alter the behaviour of organisms.

Some bacteria, both living and fossilized, contain magnetite — magnetic iron oxide crystals — that the organisms are thought to use to navigate, orienting themselves along the magnetic field lines of the Earth. But the new fossils are "unlike any magnetite crystal ever described", says Dirk Schumann of McGill University in Montreal, Canada.

Schumann and his colleagues found the fossils in sediment taken from a borehole in Ancora, New Jersey. The team dissolved the sediment in water and used a magnet to extract magnetite, which they then studied under the electron microscope. They found that the magnetite crystals contained oxygen isotopes that showed they were of aquatic origin.

Here be giants

Most of the fossils were "giants" in the world of magnetite producing microorganisms, says Schumann, up to eight times as large as those previously seen. Some were up to 4 micrometres in length. Even the shapes, like spear heads and elongated diamonds, were forms that have never been seen before in the magnetite structures of fossils or living organisms. The team reports its findings in the Proceedings of the National Academy of Sciences.¹

Scientists know of no microorganisms that create such large or oddly shaped magnetite crystals. Schumann says that the newly discovered crystals must have come from eukaryotes — a more complex form of life than the bacteria from which most previous magnetite crystals are thought to have come. "That's a convincing argument, and these new fossils are very intriguing," says Richard Frankel, a retired California Polytechnic State University physicist in San Luis Obispo, who studied magnetite-loving bacteria.

The giant microbes may have been using their crystals for orientation. It is also possible that some used the spear-like crystals as coats of armour, says co-author Robert Kopp of Princeton University in New Jersey. A type of living snail, discovered near deep-sea vents in the Indian Ocean, uses a similar material for protection. The snail grows iron-sulphide scales over its foot, from which it can excrete toxic sulphides.

Perfect climate

The sediments in which the crystals were found dated back 55 million years, to the Paleocene-Eocene Thermal Maximum. This was a time period stretching tens of thousands of years, during which Earth's global temperature spiked abruptly by around 5–9° Celsius.

This suggests that major changes in climate made the conditions perfect for bigger microbes to start "loving" iron oxide, says earth scientist James Zachos at University of California, Santa Cruz. The finding backs predictions that the ecology of the coastal oceans will change in unexpected ways as temperatures rise with current global warming, he says.

To pin down the function of the crystals, the team will search for modern microorganisms that make magnetite structures of the same sizes and shapes. They might find them in tropical oceanic shelves fed by energetic river systems, such as the Amazon, where the amount of reactive iron is twice that of delta environments such as New Jersey's coast. This will tell scientists "a lot about the conditions that allowed these structures to grow in the first place", says Kopp.

References
1. Schumann, D. et al. Proc. Natl Acad. Sci doi: 10.1073/pnas.0803634105 (2008).

Again, women takes the backseat in research front..

2008-10-09T22:18:00.001+08:00

Who cares about eggs and ovaries when you can get the same from sperm and balls?

We have more too! XD

Human Testicles Yield Stem Cells

Brian Handwerk
for National Geographic News

October 8, 2008

Scientists have derived potentially therapeutic stem cells from adult, human testicles—a development that may eventually make new medical treatments possible while avoiding moral dilemmas.

Stem cell generation for individual therapies could address a wide range of ailments, including Parkinson's disease, leukemia, and spinal cord injuries.

So far, the most versatile human stem cells have come from embryos—fertilized eggs—that critics say should not be used in scientific research because they are potential humans.

(Read about the stem cell divide in National Geographic Magazine.)

Study co-author Thomas Skutella, of the University of Tübingen in Baden-Württemberg, Germany, and his team isolated stem cells from adult, human testicles and cultivated them to become pluripotent cells, which can develop into many other types of cells.

"In the sense that they become pluripotent, they are like embryonic stem cells," Skutella wrote in an email.

Easing Concerns

A major breakthrough was made in 2006, when several research teams harvested stem cells from the testicles of adult mice.

Duplicating the feat in humans had proved elusive prior to research published online this week in Nature.

Japanese researchers announced in August that they had isolated stem cells in adult, human teeth, but the team's work was not peer reviewed.

"As you might imagine, this is a pretty significant step forward," said Chad Cowan of Harvard University's Department of Stem Cell and Regenerative Biology.

Cowan is unaffiliated with the research.

"It looks like [the cells] have a broader development potential to become a lot of the different cell types we'd be interested in," he added.

"It's very exciting that we may now have a non-ethically troubling source of pluripotent cells for humans—or at least males."

One's Own Cells

The cells, which can be harvested from living men, may also remove some immunological obstacles.

"The exciting thing about this source of stem cells is that they are the patient's own and can be used to develop individual cell-based therapies that will not provoke any kind of immune reaction," Skutella said.

"That is one of the big drawbacks of embryonic stem cells: Quite aside from the grave ethical considerations, they remain a foreign body and will always create immunological problems."

Scientists hope that a similar cell source can be found in women.

Cellular Toolbox

But Skutella cautioned that the research is just a valuable step forward, and scientists must learn how to harness the cells to benefit patients.

Though pluripotent stem cells can be differentiated into any other kind of cell, they can't be implanted in their pluripotent state. They must be differentiated so that they self-renew as only one specific type of cell.

"Stem cell therapy is extremely promising, but it is still in its infancy," Skutella explained.

"You could think of it like this: What we have successfully done right now is identify a mother lode. That ore now needs to be forged into tools, i.e. the various differentiated cell lines," he wrote.

"Then someone needs to figure out how to use those tools to fix what's broken, [that is] to develop concrete therapies."

Enzymes that do TWO things! Whoa!

2008-10-07T14:46:00.001+08:00

Cool, more general than it's supposed to be. Also, the bio teacher's nightmare: proteins are extremely specific, and can only do one thing. "but sir, there's this virus with a protein that can do TWO things! HA!!"

'Two In One' Enzyme: Unusually Flexible

ScienceDaily (Oct. 6, 2008) — Scientists from the Ruhr-University Bochum (RUB) have solved the structure of an unusually flexible enzyme in a virus that infects marine bacteria.

The virus, which infects the marine cyanobacterium Prochlorococcus, can produce specific pigments more effectively than its host can. It requires only one enzyme, in contrast to the host Prochlorococcus, which needs two enzymes. The virus makes use of phycoerythrobilin synthase, a "two in one" enzyme.

As part of his dissertation, Thorben Dammeyer, a member of the research team under the supervision of Prof. Nicole Frankenberg-Dinkel (Physiology of Microorganisms) and Assistant Professor Dr. Eckhard Hofmann (X-ray diffraction analysis of proteins), solved the 3D structure of the enzyme. An unexpected flexibility was discovered, allowing sections of the protein to assume different positions – an unusual property for proteins in combination with their substrate.

The scientists have documented their results, honored as "Paper of the Week," in the current issue of the Journal of Biological Chemistry.

Pigments are produced in two steps

The so-called P-SSM2 virus with the "two in one" enzyme infects the cyanobacterium Prochlorococcus, a cyanobacterium found in extremely large numbers in the worlds oceans. The virus does however differ in that - in contrast to its cyanobacterial relatives - it does not harvest light for photosynthesis via red and blue pigments, but with chlorophyll, as is the case with higher plants. Nevertheless Prochlorococcus contains all the genetic information for the entire machinery required to produce these pigments. This takes place in two steps with two different enzymes as catalysts.

Green turns red in one step

Nicole Frankenberg-Dinkel stated that "we have discovered the genetic blueprint for an enzyme within the virus. This enzyme is capable of producing the red pigment more effectively than its host, which has convinced us that the pigment cannot be unimportant for Prochlorococcus, even if it is not required for light trapping. On the other hand, we obviously wanted to know how this enzyme can combine two functions."

The scientists used X-ray diffraction analysis to determine the 3D structure of the enzyme at atomic resolution both alone and in complex with its natural substrate, the green biliverdin IXa. This molecule was found in the binding pocket of the protein, where the conversion into a red pigment takes place.

Prof. Frankenberg-Dinkel explained that the scientists were able to observe how different parts of the enzyme around the binding pocket are capable of assuming different positions. "This property might not be unusual for proteins in solution, but is extremely rarely found in protein crystals." The structural variations observed supplied the scientists with the first indications of the movements of the enzyme during catalysis.

Next step: tracking the evolution

The next stage of research will consist of studies of targeted and randomly genetically altered forms of the unusually flexible protein. Using this system, the scientists want to observe the in vitro evolution of this specific enzyme. Nicole Frankenberg-Dinkel's and Eckhard Hofmann's research teams are funded by the Collaborative Research Centre 480 "Molecular Biology of Complex Functions in Botanical Systems."

Not kidding. This article is not for the faint of heart.

2008-10-06T15:41:00.001+08:00

Big Bang or Big Bounce?: New Theory on the Universe's Birth

Our universe may have started not with a big bang but with a big bounce—an implosion that triggered an explosion, all driven by exotic quantum-gravitational effects

By Martin Bojowald

Atoms are now such a commonplace idea that it is hard to remember how radical they used to seem. When scientists first hypothesized atoms centuries ago, they despaired of ever observing anything so small, and many questioned whether the concept of atoms could even be called scientific. Gradually, however, evidence for atoms accumulated and reached a tipping point with Albert Einstein's 1905 analysis of Brownian motion, the random jittering of dust grains in a fluid. Even then, it took another 20 years for physicists to develop a theory explaining atoms—namely, quantum mechanics—and another 30 for physicist Erwin Müller to make the first microscope images of them. Today entire industries are based on the characteristic properties of atomic matter.

Physicists' understanding of the composition of space and time is following a similar path, but several steps behind. Just as the behavior of materials indicates that they consist of atoms, the behavior of space and time suggests that they, too, have some fine-scale structure—either a mosaic of spacetime "atoms" or some other filigree work. Material atoms are the smallest indivisible units of chemical compounds; similarly, the putative space atoms are the smallest indivisible units of distance. They are generally thought to be about 10^–35 meter in size, far too tiny to be seen by today's most powerful instruments, which probe distances as short as 10^–18 meter. Consequently, many scientists question whether the concept of atomic spacetime can even be called scientific. Undeterred, other researchers are coming up with possible ways to detect such atoms indirectly.

The most promising involve observations of the cosmos. If we imagine rewinding the expansion of the universe back in time, the galaxies we see all seem to converge on a single infinitesimal point: the big bang singularity. At this point, our current theory of gravity—Einstein's general theory of relativity—predicts that the universe had an infinite density and temperature. This moment is sometimes sold as the beginning of the universe, the birth of matter, space and time. Such an interpretation, however, goes too far, because the infinite values indicate that general relativity itself breaks down. To explain what really happened at the big bang, physicists must transcend relativity. We must develop a theory of quantum gravity, which would capture the fine structure of spacetime to which relativity is blind.

The details of that structure came into play under the dense conditions of the primordial universe, and traces of it may survive in the present-day arrangement of matter and radiation. In short, if spacetime atoms exist, it will not take centuries to find the evidence, as it did for material atoms. With some luck, we may know within the coming decade.

Pieces of Space
Physicists have devised several candidate theories of quantum gravity, each applying quantum principles to general relativity in a distinct way. My work focuses on the theory of loop quantum gravity ("loop gravity," for short), which was developed in the 1990s using a two-step procedure. First, theorists mathematically reformulated general relativity to resemble the classical theory of electromagnetism; the eponymous "loops" of the theory are analogues of electric and magnetic field lines. Second, following innovative procedures, some that are akin to the mathematics of knots, they applied quantum principles to the loops. The resulting quantum gravity theory predicts the existence of spacetime atoms [see "Atoms of Space and Time," by Lee Smolin; Scientific American, January 2004].

Other approaches, such as string theory and so-called causal dynamical triangulations, do not predict spacetime atoms per se but suggest other ways that sufficiently short distances might be indivisible [see "The Great Cosmic Roller-Coaster Ride," by Cliff Burgess and Fernando Quevedo; Scientific American, November 2007, and "The Self-Organizing Quantum Universe," by Jan Ambjørn, Jerzy Jurkiewicz and Renate Loll; Scientific American, July]. The differences among these theories have given rise to controversy, but to my mind the theories are not contradictory so much as complementary. String theory, for example, is very useful for a unified view of particle interactions, including gravity when it is weak. For the purpose of disentangling what happens at the singularity, where gravity is strong, the atomic constructions of loop gravity are more useful.

The theory's power is its ability to capture the fluidity of spacetime. Einstein's great insight was that spacetime is no mere stage on which the drama of the universe unfolds. It is an actor in its own right. It not only determines the motion of bodies within the universe, but it evolves. A complicated interplay between matter and spacetime ensues. Space can grow and shrink.

Loop gravity extends this insight into the quantum realm. It takes our familiar understanding of particles of matter and applies it to the atoms of space and time, providing a unified view of our most basic concepts. For instance, the quantum theory of electromagnetism describes a vacuum devoid of particles such as photons, and each increment of energy added to this vacuum generates a new particle. In the quantum theory of gravity, a vacuum is the absence of spacetime—an emptiness so thorough we can scarcely imagine it. Loop gravity describes how each increment of energy added to this vacuum generates a new atom of spacetime.

The spacetime atoms form a dense, ever shifting mesh. Over large distances, their dynamism gives rise to the evolving universe of classical general relativity. Under ordinary conditions, we never notice the existence of these spacetime atoms; the mesh spacing is so tight that it looks like a continuum. But when spacetime is packed with energy, as it was at the big bang, the fine structure of spacetime becomes a factor, and the predictions of loop gravity diverge from those of general relativity.

Attracted to Repulsion
Applying the theory is an extremely complex task, so my colleagues and I use simplified versions that capture the truly essential features of the universe, such as its size, and ignore details of lesser interest. We have also had to adapt many of the standard mathematical tools of physics and cosmology. For instance, theoretical physicists commonly describe the world using differential equations, which specify the rate of change of physical variables, such as density, at each point in the spacetime continuum. But when spacetime is grainy, we instead use so-called difference equations, which break up the continuum into discrete intervals. These equations describe how a universe climbs up the ladder of sizes that it is allowed to take as it grows. When I set out to analyze the cosmological implications of loop gravity in 1999, most researchers expected that these difference equations would simply reproduce old results in disguise. But unexpected features soon emerged.

Gravity is typically an attractive force. A ball of matter tends to collapse under its own weight, and if its mass is sufficiently large, gravity overpowers all other forces and compresses the ball into a singularity, such as the one at the center of a black hole. But loop gravity suggests that the atomic structure of spacetime changes the nature of gravity at very high energy densities, making it repulsive. Imagine space as a sponge and mass and energy as water. The porous sponge can store water but only up to a certain amount. Fully soaked, it can absorb no more and instead repels water. Similarly, an atomic quantum space is porous and has a finite amount of storage space for energy. When energy densities become too large, repulsive forces come into play. The continuous space of general relativity, in contrast, can store a limitless amount of energy.

Because of the quantum-gravitational change in the balance of forces, no singularity—no state of infinite density—can ever arise. According to this model, matter in the early universe had a very high but finite density, the equivalent of a trillion suns in every proton-size region. At such extremes, gravity acted as a repulsive force, causing space to expand; as densities moderated, gravity switched to being the attractive force we all know. Inertia has kept the expansion going to the present day.

In fact, the repulsive gravity caused space to expand at an accelerating rate. Cosmological observations appear to require such an early period of acceleration, known as cosmic inflation. As the universe expands, the force driving inflation slowly subsides. Once the acceleration ends, surplus energy is transferred to ordinary matter, which begins to fill the universe in a process called reheating. In current models, inflation is somewhat ad hoc—added in to conform to observations—but in loop quantum cosmology, it is a natural consequence of the atomic nature of spacetime. Acceleration automatically occurs when the universe is small and its porous nature still quite significant.

Time before Time
Without a singularity to demarcate the beginning of time, the history of the universe may extend further back than cosmologists once thought possible. Other physicists have reached a similar conclusion [see "The Myth of the Beginning of Time," by Gabriele Veneziano; Scientific American, May 2004], but only rarely do their models fully resolve the singularity; most models, including those from string theory, require assumptions as to what might have happened at this uneasy spot. Loop gravity, in contrast, is able to trace what took place at the singularity. Loop-based scenarios, though admittedly simplified, are founded on general principles and avoid introducing new ad hoc assumptions.

Using the difference equations, we can try to reconstruct the deep past. One possible scenario is that the initial high-density state arose when a preexisting universe collapsed under the attractive force of gravity. The density grew so high that gravity switched to being repulsive, and the universe started expanding again. Cosmologists refer to this process as a bounce.

The first bounce model investigated thoroughly was an idealized case in which the universe was highly symmetrical and contained just one type of matter. Particles had no mass and did not interact with one another. Simplified though this model was, understanding it initially required a set of numerical simulations that were completed only in 2006 by Abhay Ashtekar, Tomasz Pawlowski and Parampreet Singh, all at Pennsylvania State University. They considered the propagation of waves representing the universe both before and after the big bang. The model clearly showed that a wave would not blindly follow the classical trajectory into the abyss of a singularity but would stop and turn back once the repulsion of quantum gravity set in.

An exciting result of these simulations was that the notorious uncertainty of quantum mechanics seemed to remain fairly muted during the bounce. A wave remained localized throughout the bounce rather than spreading out, as quantum waves usually do. Taken at face value, this result suggested that the universe before the bounce was remarkably similar to our own: governed by general relativity and perhaps filled with stars and galaxies. If so, we should be able to extrapolate from our universe back in time, through the bounce, and deduce what came before, much as we can reconstruct the paths of two billiard balls before a collision based on their paths after the collision. We do not need to know each and every atomic-scale detail of the collision.

Unfortunately, my subsequent analysis dashed this hope. The model as well as the quantum waves used in the numerical simulations turned out to be a special case. In general, I found that waves spread out and that quantum effects were strong enough to be reckoned with. So the bounce was not a brief push by a repulsive force, like the collision of billiard balls. Instead it may have represented the emergence of our universe from an almost unfathomable quantum state—a world in highly fluctuating turmoil. Even if the preexisting universe was once very similar to ours, it passed through an extended period during which the density of matter and energy fluctuated strongly and randomly, scrambling everything.

The fluctuations before and after the big bang were not strongly related to each other. The universe before the big bang could have been fluctuating very differently than it did afterward, and those details did not survive the bounce. The universe, in short, has a tragic case of forgetfulness. It may have existed before the big bang, but quantum effects during the bounce wiped out almost all traces of this prehistory.

Some Scraps of Memory
This picture of the big bang is subtler than the classical view of the singularity. Whereas general relativity simply fails at the singularity, loop quantum gravity is able to handle the extreme conditions there. The big bang is no longer a physical beginning or a mathematical singularity, but it does put a practical limitation on our knowledge. Whatever survives cannot provide a complete view of what came before.

Frustrating as this may be, it might be a conceptual blessing. In physical systems as in daily life, disorder tends to increase. This principle, known as the second law of thermodynamics, is an argument against an eternal universe. If order has been decreasing for an infinite span of time, the universe should by now be so disorganized that structures we see in galaxies as well as on Earth would be all but impossible. The right amount of cosmic forgetfulness may come to the rescue by presenting the young, growing universe with a clean slate irrespective of all the mess that may have built up before.

According to traditional thermodynamics, there is no such thing as a truly clean slate; every system always retains a memory of its past in the configuration of its atoms [see "The Cosmic Origins of Time's Arrow," by Sean M. Carroll; Scientific American, June]. But by allowing the number of spacetime atoms to change, loop quantum gravity allows the universe more freedom to tidy up than classical physics would suggest.

All that is not to say that cosmologists have no hope of probing the quantum-gravitational period. Gravitational waves and neutrinos are especially promising tools, because they barely interact with matter and therefore penetrated the primordial plasma with minimal loss. These messengers might well bring us news from a time near to, or even before, the big bang.

One way to look for gravitational waves is by studying their imprint on the cosmic microwave background radiation [see "Echoes from the Big Bang," by Robert R. Caldwell and Marc Kamionkowski; Scientific American, January 2001]. If quantum-gravitational repulsive gravity drove cosmic inflation, these observations might find some hint of it. Theorists must also determine whether this novel source of inflation could reproduce other cosmological measurements, especially of the early density distribution of matter seen in the cosmic microwave background.

At the same time, astronomers can look for the spacetime analogues of random Brownian motion. For instance, quantum fluctuations of spacetime could affect the propagation of light over long distances. According to loop gravity, a light wave cannot be continuous; it must fit on the lattice of space. The smaller the wavelength, the more the lattice distorts it. In a sense, the spacetime atoms buffet the wave. As a consequence, light of different wavelengths travels at different speeds. Although these differences are tiny, they may add up during a long trip. Distant sources such as gamma-ray bursts offer the best hope of seeing this effect [see "Window on the Extreme Universe," by William B. Atwood, Peter F. Michelson and Steven Ritz; Scientific American, December 2007].

In the case of material atoms, more than 25 centuries elapsed between the first speculative suggestions of atoms by ancient philosophers and Einstein's analysis of Brownian motion, which firmly established atoms as the subject of experimental science. The delay should not be as long for spacetime atoms.

Ig Nobel Prize.. what the heck??

2008-10-04T14:11:00.001+08:00

This is totally random, but the sperm study just takes it home. Best when it's tied to an opposing study.

P.S. Ovulating women are happier? O.o

Smart Slime, Ovulating Strippers Among 2008 Ig Nobels

Brian Handwerk
for National Geographic News

October 3, 2008

Some fake drugs are better than others, armadillos are assaulting our history, and slime mold is smarter than we think—these and other offbeat scientific triumphs were honored Thursday night at the 2008 Ig Nobel Prize ceremony.

The prizes celebrate "achievements that first make people laugh, and then make them think."

More than 1,200 people attended a raucous affair at Harvard University, dubbed the "18th First Annual Ig Nobel Prize Ceremony" in honor of this year's theme—redundancy.

William Lipscomb, who had won the Nobel Prize in chemistry in 1976, dispensed prizes to the ten honorees. He himself was the prize in the Win a Date With a Nobel Laureate contest.

The gala is thrown every year by the science/humor journal Annals of Improbable Research (AIR).

(Related: "Poop Vanilla, Endless Soup Among 2007 Ig Nobels" [October 5, 2007].)

Generics and Jerks

Duke University business professor Dan Ariely, author of Predictably Irrational: The Hidden Forces That Shape Our Decisions, took home the Ig Nobel Prize for medicine.

In one study covered in the book, a group of people took placebos—fake pharmaceuticals—that they were told were expensive. Another group took the same pills but was told the drugs were inexpensive.

The "expensive" pills were found to be more effective pain relievers than the "cheap" ones.

The study could have implications for patients given generic, instead of brand-name, medications.

An eight-year-old girl, Miss Sweetie-Poo, chased Ariely from the podium when he delivered an acceptance speech longer than the allotted 60 seconds.

Organizers employed the child to loudly repeat "Please stop! I'm bored!" when winners exceeded the time limit.

David Sims of Cass Business School, London, won the Ig Nobel Prize for literature for a workplace study entitled "You Bastard: A Narrative Exploration of the Experience of Indignation Within Organizations."

Sims explained that consistent behavior, even bad behavior, isn't as maddening as that which leaves one struggling for an explanation. A predictable jerk, in other words, isn't as distressing as a loose cannon.

"Hero, fool, villain—what is this person going to be in [the story of my life]?" he asked. "The people you get really angry with are the ones who don't settle into a single character—you just can't work out what they're up to."

The findings had stuck a familiar chord with many readers.

"When I was taking this around as a seminar paper, everyone was convinced that I had gathered my data in their institution."

Snacks, Smart Mold, and Super Fleas

The Ig Nobel for nutrition was bestowed for an unusual taste test. Scientists had electronically enhanced the sound made when a person bites into a potato chip. Testers were fooled into thinking their snack was crisper and fresher than it actually was.

Japanese and Hungarian scientists captured the Ig Nobel in cognitive science for proving that slime mold can navigate a maze.

When placed in a maze with food sources on both ends, the organism had spread "like mayonnaise on a slice of bread," said Ryo Kobayashi of Hiroshima University in Japan.

But after about ten hours, the mold had abandoned the maze's dead ends and inhabited only the most direct route between the food sources.

Three French scientists took the Ig Nobel biology honors by demonstrating that fleas living on dogs can jump higher than those living on cats.

And though history may be written by the winners, archaeological history can be rewritten by the burrowing of armadillos. A Brazilian team won the archaeology Ig Nobel for demonstrating live armadillos can scramble the locations of artifacts in an archaeological dig site.

Reflections on Plants, Strippers, and Coca-Cola

Urs Thurnherr, of the Swiss Federal Ethics Committee on Non-Human Biotechnology, accepted the Ig Nobel Peace Prize on behalf of the citizens of Switzerland—who have adopted the constitutional principle that plants have inherent dignity.

On stage, Thurnherr asked, "Have you ever been away or forgotten to water one of your house plants and then had to throw it away? Did that make you feel uneasy in any way?"

The prize in economics went to Geoffrey Miller, Joshua Tybur, and Brent Jordan of the University of New Mexico, who had discovered that lap dancers' tip earnings rise and fall with their ovulatory cycles—from an average of U.S. $70 per hour when about to ovulate to just $35 during menstruation.

Previous studies had shown that women in mid-cycle have faces and breasts that are more attractive to men, as well as a more appealing scent, Miller said.

Research also suggests that many women are happier at this time.

"Men are probably responding partly to physical appearance and smell, and quite a bit to behavior, happiness, and outgoingness—but we really don't know yet," Miller said.

The physics prize went to a team that had unveiled a new type of string theory. This version was a mathematical proof that piles of string or hair will inevitably tangle themselves up in knots.

*The chemistry prize was shared by two groups that had conclusively put an urban legend to rest—sort of.

Deborah Anderson, of Boston University School of Medicine and Harvard Medical School, was recognized for her 1980s discovery that Coca-Cola is an effective spermicide (though not a reliable form of birth control).

"I'd like to thank the Ig Nobels for recognizing our seminal study," she quipped.

However, Anderson shared the prize with a team of Taiwanese scientists who had proved just the opposite.

With the winners crowned and the stage swept clear of paper airplanes tossed by the audience, Marc Abrahams, editor of the Annals of Improbable Research, closed the evening in traditional style.

"If you didn't win an Ig Nobel Prize tonight—and especially if you did—better luck next year."

Follow the leader

2008-10-04T13:34:00.001+08:00

Bees can follow too, so don't look down on their intelligence. J

Bee Swarms Follow High-speed 'Streaker' Bees To Find A New Nest

ScienceDaily (Oct. 3, 2008) — It's one of the hallmarks of spring: a swarm of bees on the move. But how a swarm locates a new nest site when less than 5% of the community know the way remains a mystery. Curious to find out how swarms cooperate and are guided to their new homes, Tom Seeley, a neurobiologist from Cornell University, and engineers Kevin Schultz and Kevin Passino from The Ohio State University teamed up to find out how swarms are guided to their new home.

According to Schultz there are two theories on how swarms find the way. In the 'subtle guide' theory, a small number of scout bees, which had been involved in selecting the new nest site, guide the swarm by flying unobtrusively in its midst; near neighbours adjust their flight path to avoid colliding with the guides while more distant insects align themselves to the guides' general direction. In the 'streaker bee' hypothesis, bees follow a few conspicuous guides that fly through the top half of the swarm at high speed.

Schultz explains that Seeley already had still photographs of the streaks left by high-speed bees flying through a swarm's upper layers, but what Seeley needed was movie footage of a swarm on the move to see if the swarm was following high-velocity streakers or being unobtrusively directed by guides. Passino and Seeley decided to film swarming bees with high-definition movie cameras to find out how they were directed to their final destination.

But filming diffuse swarms spread along a 12·m length with each individual on her own apparently random course is easier said than done. For a start you have to locate your camera somewhere along the swarm's flight path, which is impossible to predict in most environments. The team overcame this problem by relocating to Appledore Island, which has virtually no high vegetation for swarms to settle on. By transporting large colonies of bees, complete with queen, to the island, the team could get the insects to swarm from a stake to the only available nesting site; a comfortable nesting box. Situating the camera on the most direct route between the two sites, the team successfully filmed several swarms' chaotic progress at high resolution.

Back in Passino's Ohio lab, Schultz began the painstaking task of analysing over 3500 frames from a swarm fly-by to build up a picture of the insects' flight directions and vertical position. After months of bee-clicking, Schultz was able to find patterns in the insects' progress. For example, bees in the top of the swarm tended to fly faster and generally aimed towards the nest, with bees concentrated in the middle third of the top layer showing the strongest preference to head towards the nest.

Schultz also admits that he was surprised at how random the bees' trajectories were in the bottom half of the swarm, 'they were going in every direction,' he says, but the bees that were flying towards the new nest generally flew faster than bees that were heading in other directions; they appeared to latch onto the high-speed streakers. All of which suggests that the swarm was following high-speed streaker bees to their new location.

And why I laugh at you XD, More sleep = better study.

2008-10-03T12:27:00.001+08:00

Ask the Brains: Why Do We Laugh When Someone Falls?

Also: Does napping after a meal affect memory formation?

By The Editors

Why do we find it funny when some one falls down?
—William B. Keith, Houston

William F. Fry, a psychiatrist and laughter researcher at Stanford University, explains:

Every human develops a sense of humor, and everyone's taste is slightly different. But certain fundamental aspects of humor help explain why a misstep may elicit laughter.

The first requirement is the "play frame," which puts a real-life event in a nonserious context and allows for an atypical psychological reaction. Play frames explain why most people will not find it comical if someone falls from a 10-story building and dies: in this instance, the falling person's distress hinders the establishment of the nonserious context. But if a woman casually walking down the street trips and flails hopelessly as she stumbles to the ground, the play frame may be established, and an observer may find the event amusing.

Another crucial characteristic is incongruity, which can be seen in the improbable or inconsistent relation between the "punch line" and the "body" of a joke or experience. Falls are incongruent in the normal course of life in that they are unexpected. So despite our innate empathetic reaction—you poor fellow!—our incongruity instinct may be more powerful. Provided that the fall event establishes a play frame, mirth will likely ensue.

Play frames and incongruity are psychological concepts; only recently has neurobiology caught up with them. In the early 1990s the discovery of mirror neurons led to a new way to understand the incongruity aspect of humor. When we fall down, we thrash about as we reach out to catch ourselves. Neu rons in our brain control these movements. But when we observe another person stumbling, some of our own neurons fire as if we were the person doing the flailing—these mirror neurons are duplicating the patterns of activity in the falling person's brain. My hypothesis regarding the relevance of this mechanism for humor behavior is that the observer's brain is "tickled" by that neurological "ghost." The observer experiences an unconscious stimulation from that ghost, reinforcing the incongruity perception.

Does napping after a meal affect memory formation?
—Yadhu Kumar, Konstanz, Germany

Neuroendocrinologists Manfred Hallschmid and Susanne Diekelmann of the University of Lübeck in Germany reply:

The past two decades have yielded considerable evidence for sleep's pivotal role in memory consolidation. The lion's share of research has focused on the relevance of longer periods of nocturnal rest. For that reason, the duration that is actually needed for sleep's effects on memory to become behaviorally relevant has not yet been exhaustively investigated. We have reason to assume, however, that even short periods of rest can indeed improve memory formation.

There are only a handful of studies investigating the effect of a short nap on the consolidation of declarative memories, which involve facts and events. Most of these studies have reported better memory performance after sleep as compared with wakefulness, revealing improvements of 4 to 46 percent in word-pair memory after a nap and a 3 percent loss to a 28 percent improvement after wakefulness. Even an ultrashort catnap of about six minutes resulted in better memory retention than staying awake did, but a longer doze of 35 minutes was clearly superior. Interestingly, a number of experiments have indicated that sleep improves memory regardless of whether it occurs during the night or the day, which further highlights the cognitive potential of a postprandial nap.

Research on procedural memory, which comprises perceptual and motor skills (such as learning to play an instrument), has found that a short siesta of 60 to 90 minutes improves visual perception only if the nap includes both slow-wave and rapid-eye-movement sleep, the two phases that the brain cycles through while we doze. In studies focusing on motor skills, such as those in which subjects were asked to repetitively type certain keyboard sequences, a posttraining nap of 60 to 90 minutes likewise improved finger-tapping performance. Even so, the study participants did not show as much improvement after the nap as they did after the following full night of sleep.

In sum, these observations suggest that napping may indeed help you remember what you have just learned but that you need longer periods of shut-eye to tap the full potential of sleep.

Note: This story was originally published with the title, "Ask the Brains".

What’s cooking? Ask my pet wasps XD

2008-10-03T12:08:00.002+08:00

seriously, this is cool. the method's gonna be a better deterrent than catching him red handed. "we suspect you have drugs in your rectum" "i do not!" "we strongly suggest you give up or we'll put you in this room full of wasps that can smell drugs. imagine what they'll do to your butt" "fine! i have drugs in my rectum! just don't let them sting my ass!"

Wasps: Man's New Best Friend!
Entomologists Train Insects to Act Like Sniffing Dogs

July 1, 2006 — If rewarded with sugary water, wasps can be trained in minutes to follow specific smells. The olfactory sensors in their antennae can sense chemicals in the air in concentrations as tiny as a few parts per billion. Wasps could be cost-effective helpers in searching for explosives, toxic chemicals, and even fungi on crops.

ATHENS, Ga. -- Wasps are not man's best friend -- probably their worst. But when it comes to sniffing out trouble, scientists believe they may be better than dogs.

They ward off intruders, track down criminals, find bombs and detect toxic chemicals, but dogs could soon be replaced by wasps. They have the same sensitive odor detection as dogs and are now being trained to sniff out trouble.

"The advantages of a wasp over a dog is you can produce them by the thousands. They are real inexpensive, and you can train them in a matter of minutes," Joe Lewis, a research entomologist at University of Georgia in Athens, tells DBIS.

He and Biological and agricultural engineer Glen Rains are doing just that. Olfactory sensors on the wasps' antennae can smell chemicals in concentrations as tiny as a few parts per billion in the air.

"So far, they've been able to detect, to some level, any chemical that we've trained them to," Rains tells DBIS.

Training is simple and quick. The wasps are fed sugar water. At the same time they're introduced to a smell for 10 seconds. The process is repeated two more times.

Lewis says, "We can train a wasp within a matter of 10 to 15 minutes."

For example, a set of wasps is trained to detect the smell of coffee. When they are put into a simple container, a tiny web camera watches their actions. When the smell of orange is pumped into the pipe, nothing. But when it's coffee, the wasps crowd around the smell.

So far, Rains and Lewis have not found anything the wasps cannot be trained to detect. They can be trained to detect everything from drugs to human remains to fungi on crops. They could one day even be able to detect deadly diseases like cancer.

BACKGROUND: Scientists from the University of Georgia and the USDA Agricultural Research Service are training wasps to detect the telltale odors of concealed explosives, drugs and human remains, and possibly one day certain diseases like cancer. They are now investigating whether it is possible to train mosquitoes as living odor detectors as well, and plan to eventually study other insects with excellent sniffing ability, like honeybees and moths.

HOW IT WORKS: The Georgia scientists have built a device they call the Wasp Hound: an odor-detection device that costs around $60. It is made of a small PVC tube containing five wasps that can be trained to detect any target odor within minutes. The device has a fan at the top, which draws odors into the tube through a filter. If the wasps catch a whiff of whatever they've been trained to smell, they crowd around a hole in the filter. A web cam inside the tube is attached to a computer, which alerts the operator to the wasps' reaction with a beep or a flashing light. The Wasp Hound could be used by farmers to monitor crops for diseases and pests; to check for explosives in airport security applications; to help doctors monitor diseases, or even by defense forces searching for buried land mines.

ADVANTAGES: Unlike dogs and the electronic sensors more commonly used today, wasps are cheap and disposable. It costs pennies and takes minutes to train them: Feed them sugar water while introducing them to a target smell for 10 seconds; give them a 30-second break, repeat the process twice more, and they are completely trained to track that single scent.

ABOUT WASPS: Wasps have olfactory sensors on their antennae that they use to stay alive. For instance, one strain of wasp lays its eggs inside a specific variety of caterpillar. The insects are attracted to the caterpillars by chemicals released by plans as the caterpillars much on them -- a type of SOS signal from the plants. This is also how wasps attract mates. Wasps can sense chemicals in concentrations as tiny as a few parts per billion in the air ý the same range to which dogs and chemical sensors are sensitive. Some species can pick up scents at concentrations as low as one part in a thousand billion, which is a hundred thousand times weaker that the concentrations detectable by commercial "electronic noses."

Note: This story and accompanying video were originally produced for the American Institute of Physics series Discoveries and Breakthroughs in Science by Ivanhoe Broadcast News and are protected by copyright law. All rights reserved.

OOOH, scientific backing to gossip XD

2008-10-01T20:03:00.001+08:00

Girls, you now have an evolutionary reason to gossip XD

The Science of Gossip: Why We Can't Stop Ourselves

It helped us thrive in ancient times, and in our modern world it makes us feel connected to others—as long as it is done properly

By Frank T. McAndrew

In the past few years I have heard more people than ever before puzzling over the 24/7 coverage of people such as Paris Hilton who are "celebrities" for no apparent reason other than we know who they are. And yet we can't look away. The press about these individuals' lives continues because people are obviously tuning in. Although many social critics have bemoaned this explosion of popular culture as if it reflects some kind of collective character flaw, it is in fact nothing more than the inevitable outcome of the collision between 21st-century media and Stone Age minds.

When you cut away its many layers, our fixation on popular culture reflects an intense interest in the doings of other people; this preoccupation with the lives of others is a by-product of the psychology that evolved in prehistoric times to make our ancestors socially successful. Thus, it appears that we are hardwired to be fascinated by gossip.

Only in the past decade or so have psychologists turned their attention toward the study of gossip, partially because it is difficult to define exactly what gossip is. Most researchers agree that the practice involves talk about people who are not present and that this talk is relaxed, informal and entertaining. Typically the topic of conversation also concerns information that we can make moral judgments about. Gossip appears to be pretty much the same wherever it takes place; gossip among co-workers is not qualitatively different from that among friends outside of work. Although everyone seems to detest a person who is known as a "gossip" and few people would use that label to describe themselves, it is an exceedingly unusual individual who can walk away from a juicy story about one of his or her acquaintances, and all of us have firsthand experience with the difficulty of keeping spectacular news about someone else a secret.

Why does private information about other people represent such an irresistible temptation for us? In his book Grooming, Gossip, and the Evolution of Language (Harvard University Press, 1996), psychologist Robin Dunbar of the University of Liverpool in England suggested that gossip is a mechanism for bonding social groups together, analogous to the grooming that is found in primate groups. Sarah R. Wert, now at the University of Colorado at Boulder, and Peter Salovey of Yale University have proposed that gossip is one of the best tools that we have for comparing ourselves socially with others. The ultimate question, however, is, How did gossip come to serve these functions in the first place?

An Evolutionary Adaptation?
When evolutionary psychologists detect something that is shared by people of all ages, times and cultures, they usually suspect that they have stumbled on a vital aspect of human nature, something that became a part of who we are in our long-forgotten prehistoric past. Evolutionary adaptations that enabled us not only to survive but to thrive in our prehistoric environment include our appreciation of landscapes containing freshwater and vegetation, our never-ending battle with our sweet tooth and our infatuation with people who look a certain way.

It is obvious to most people that being drawn to locations that offer resources, food that provides energy, and romantic partners who appear able to help you bear and raise healthy children might well be something that evolution has selected for because of its advantages. It may not be so clear at first glance, however, how an interest in gossip could possibly be in the same league as these other preoccupations. If we think in terms of what it would have taken to be successful in our ancestral social environment, the idea may no longer seem quite so far-fetched.

As far as scientists can tell, our prehistoric forebears lived in relatively small groups where they knew everyone else in a face-to-face, long-term kind of way. Strangers were probably an infrequent and temporary phenomenon. Our caveman ancestors had to cooperate with so-called in-group members for success against out-groups, but they also had to recognize that these same in-group members were their main competitors when it came to dividing limited resources. Living under such conditions, our ancestors faced a number of consistent adaptive problems such as remembering who was a reliable exchange partner and who was a cheater, knowing who would be a reproductively val uable mate, and figuring out how to successfully manage friendships, alliances and family relationships.

The social intelligence needed for success in this environment required an ability to predict and influence the behavior of others, and an intense interest in the private dealings of other people would have been handy indeed and would have been strongly favored by natural selection. In short, people who were fascinated with the lives of others were simply more successful than those who were not, and it is the genes of those individuals that have come down to us through the ages. Like it or not, our inability to forsake gossip and information about other individuals is as much a part of who we are as is our inability to resist doughnuts or sex—and for the same reasons.

A related social skill that would have had a big payoff is the ability to remember details about the temperament, predictability and past behavior of individuals who are personally known to you; there would have been little use for a mind that was designed to engage in abstract statistical thinking about large numbers of unknown outsiders. In today's world, it is advantageous to be able to think in terms of probabilities and percentages when it comes to people, because predicting the behavior of the strangers with whom we deal in everyday life requires that we do so. This task is difficult for many of us because the early wiring of the brain was guided by different needs. Thus, natural selection shaped a thirst for, and a memory to store information about, specific people; it is even well established that we have a brain area specifically dedicated to the identification of human faces.

For better or worse, this is the mental equipment we must rely on to navigate our way through a modern world filled with technology and strangers. I suppose I should not be surprised when the very same psychology students who get glassy-eyed at any mention of statistical data about human beings in general become riveted by case studies of individuals experiencing psychological problems. Successful politicians take advantage of this pervasive "power of the particular" (as cognitive psychologists call it) when they use anecdotes and personal narratives to make political points. Even Russian dictator Joseph Stalin noted that "one death is a tragedy; a million deaths is a statistic." The prevalence of reality TV shows and nightly news programs focusing on stories about a missing child or the personal gaffes of politicians is a beast of our own creation.

Is Gossip Always Bad?
The aspect of gossip that is most troubling is that in its rawest form it is a strategy used by individuals to further their own reputations and selfish interests at the expense of others. This nasty side of gossip usually overshadows the more benign ways in which it functions in society. After all, sharing gossip with another person is a sign of deep trust because you are clearly signaling that you believe that this person will not use this sensitive information in a way that will have negative consequences for you; shared secrets also have a way of bonding people together. An individual who is not included in the office gossip network is obviously an outsider who is not trusted or accepted by the group.

There is ample evidence that when it is controlled, gossip can indeed be a positive force in the life of a group. In a review of the literature published in 2004, Roy F. Baumeister of Florida State University and his colleagues concluded that gossip can be a way of learning the unwritten rules of social groups and cultures by resolving ambiguity about group norms. Gossip is also an efficient way of reminding group members about the importance of the group's norms and values; it can be a deterrent to deviance and a tool for punishing those who transgress. Rutgers University evolutionary biologist Robert Trivers has discussed the evolutionary importance of detecting "gross cheaters" (those who fail to reciprocate altruistic acts) and "subtle cheaters" (those who reciprocate but give much less than they get). [For more on altruism and related behavior, see "The Samaritan Paradox," by Ernst Fehr and Suzann-Viola Renninger; Scientific American Mind, Premier Issue 2004.]

Gossip can be an effective means of uncovering such information about others and an especially useful way of controlling these "free riders" who may be tempted to violate group norms of reciprocity by taking more from the group than they give in return. Studies in real-life groups such as California cattle ranchers, Maine lobster fishers and college rowing teams confirm that gossip is used in these quite different settings to enforce group norms when an individual fails to live up to the group's expectations. In all these groups, individuals who violated expectations about sharing resources and meeting responsibilities became frequent targets of gossip and ostracism, which applied pressure on them to become better citizens. Anthropological studies of hunter-gatherer groups have typically revealed a similar social control function for gossip in these societies.

Anthropologist Christopher Boehm of the University of Southern California has proposed in his book Hierarchy in the Forest: The Evolution of Egalitarian Behavior (Harvard University Press, 1999) that gossip evolved as a "leveling mechanism" for neutralizing the dom inance tendencies of others. Boehm believes that small-scale foraging societies such as those typical during human prehistory emphasized an egalitarianism that suppressed internal competition and promoted consensus seeking in a way that made the success of one's group extremely important to one's own fitness. These social pressures discouraged free riders and cheaters and encouraged altruists. In such societies, the manipulation of public opinion through gossip, ridicule and ostracism became a key way of keeping potentially dominant group members in check.

Favored Types of Gossip
According to one of the pioneers of gossip research, anthropologist Jerome Barkow of Dalhousie University, we should be especially interested in information about people who matter most in our lives: rivals, mates, relatives, partners in social exchange, and high-ranking figures whose behavior can affect us. Given the proposition that our interest in gossip evolved as a way of acquiring fitness-enhancing information, Barkow also suggests that the type of knowledge that we seek should be information that can affect our social standing relative to others. Hence, we would expect to find higher interest in negative news (such as misfortunes and scandals) about high-status people and potential rivals because we could exploit it. Negative information about those lower than us in status would not be as useful. There should also be less interest in passing along negative information about our friends and relatives than about people who are not allies. Conversely, positive information (good fortune and sudden elevation of status, for example) about allies should be likely to be spread around, whereas positive information about non allies should be less enticing because it is not useful in advancing one's own interests.

For a variety of reasons, our interest in the doings of same-sex others ought to be especially strong. Because same-sex members of one's own species who are close to our own age are our principal evolutionary competitors, we ought to pay special attention to them. The 18-year-old male caveman would have done much better by attending to the business of other 18-year-old males rather than the business of 50-year-old males or females of any age. Interest about members of the other sex should be strong only when their age and situational circumstances would make them appropriate as mates.

The gossip studies that my students and I have worked on at Knox College over the past decade have focused on uncovering what we are most interested in finding out about other people and what we are most likely to spread around. We have had people of all ages rank their interest in tabloid stories about celebrities, and we have asked college students to read gossip scenarios about unidentified individuals and tell us about which types of people they would most like to hear such information, about whom they would gossip and with whom they would share gossip.

In keeping with the evolutionary hypotheses suggested earlier, we have consistently found that people are most interested in gossip about individuals of the same sex as themselves who happen to be around their own age. We have also found that information that is socially useful is always of greatest interest to us: we like to know about the scandals and misfortunes of our rivals and of high-status people because this information might be valuable in social competition. Positive information about such people tends to be uninteresting to us. Finding out that someone already higher in status than ourselves has just acquired something that puts that person even further ahead of us does not supply us with ammunition that we can use to gain ground on him. Conversely, positive information about our friends and relatives is very interesting and likely to be used to our advantage whenever possible. For example, in studies that my colleagues and I published in 2002 and in 2007 in the Journal of Applied Social Psychology, we consistently found that college students were not much interested in hearing about academic awards or a large inheritance if it involved one of their professors and that they were also not very interested in passing that news along to others. Yet the same information about their friends or romantic partners was rated as being quite interesting and likely to be spread around.

We have also found that an interest in the affairs of same-sex others is especially strong among females and that women have somewhat different patterns of sharing gossip than men do. For example, our studies reveal that males report being far more likely to share gossip with their romantic partners than with anyone else, but females report that they would be just as likely to share gossip with their same-sex friends as with their romantic partners. And although males are usually more interested in news about other males, females are virtually obsessed with news about other females.

This fact can be demonstrated by looking at the actual frequency with which males and females selected a same-sex person as the most interesting subject of the gossip scenarios we presented them with in one of our studies published in 2002. On hearing about someone having a date with a famous person, 43 out of 44 women selected a female as the most interesting person to know this about, as compared with 24 out of 36 males who selected a male as most interesting. Similarly, 40 out of 42 females (versus 22 out of 37 males) were most interested in same-sex academic cheaters, and 39 out of 43 were most interested in a same-sex leukemia sufferer (as opposed to only 18 out of 37 males). In fact, the only two scenarios among the 13 we studied in which males expressed more same-sex interest than females did involved hearing about an individual heavily in debt because of gambling or an individual who was having difficulty performing sexually.

Why Such Interest in Celebrities?
Even if we can explain the intense interest that we have in other people who are socially important to us, how can we possibly explain the seemingly useless interest that we have in the lives of reality-show contestants, movie stars and public figures of all kinds? One possible explanation may be found in the fact that celebrities are a recent occurrence, evolutionarily speaking. In our ancestral environment, any person about whom we knew intimate details of his or her private life was, by definition, a socially important member of the in-group. Bar kow has pointed out that evolution did not prepare us to distinguish among members of our community who have genuine effects on our life and the images and voices that we are bombarded with by the entertainment industry. Thus, the intense familiarity with celebrities provided by the modern media trips the same gossip mechanisms that have evolved to keep up with the affairs of in-group members. After all, anyone whom we see that often and know that much about must be socially important to us. News anchors and television actors we see every day in soap operas become familiar friends.

In our modern world, celebrities may also serve another important social function. In a highly mobile, industrial society, celebrities may be the only "friends" we have in common with our new neighbors and co-workers. They provide a common interest and topic of conversation between people who otherwise might not have much to say to one another, and they facilitate the types of informal interaction that help people become comfortable in new surroundings. Hence, keeping up on the lives of actors, politicians and athletes can make a person more socially adept during interactions with strangers and even provide segues into social relationships with new friends in the virtual world of the Internet. Research published in 2007 by Charlotte J. S. De Backer, a Belgian psychologist now at the University of Leicester in England, finds that young people even look to celebrities and popular culture for learning life strategies that would have been learned from role models within one's tribe in the old days. Teenagers in particular seem to be prone to learning how to dress, how to manage relationships and how to be socially successful in general by tuning in to popular culture.

Thus, gossip is a more complicated and socially important phenomenon than we think. When gossip is discussed seriously, the goal usually is to suppress the frequency with which it occurs in an attempt to avoid the undeniably harmful effects it often has in work groups and other social networks. This tendency, however, overlooks that gossip is part of who we are and an essential part of what makes groups function as well as they do. Perhaps it may become more productive to think of gossip as a social skill rather than as a character flaw, because it is only when we do not do it well that we get into trouble. Adopting the role of the self-righteous soul who refuses to participate in gossip at work or in other areas of your social life ultimately will be self-defeating. It will turn out to be nothing more than a ticket to social isolation. On the other hand, becoming that person who indiscriminately blabs everything you hear to anyone who will listen will quickly get you a reputation as an untrustworthy busybody. Successful gossiping is about being a good team player and sharing key information with others in a way that will not be perceived as self-serving and about understanding when to keep your mouth shut.

In short, I believe we will continue to struggle with managing the gossip networks in our daily lives and to shake our heads at what we are constantly being subjected to by the mass media, rationally dismissing it as irrelevant to anything that matters in our own lives. But in case you find yourself becoming just a tiny bit intrigued by some inane story about a celebrity, let yourself off the hook and enjoy the guilty pleasure. After all, it is only human nature.

Note: This article was originally printed with the title, "Can Gossip Be Good?"

http://www.sciam.com/article.cfm?id=the-science-of-gossip

Cool stuff XD

2008-09-24T12:59:00.001+08:00

Looking Vs. Seeing

Hafed designed a series of experiments where the subjects had to infer the invisible center of a visual target consisting of two peripheral features and track it for several seconds. (Credit: Image courtesy of Salk Institute)

ScienceDaily (Sep. 23, 2008) — The superior colliculus has long been thought of as a rapid orienting center of the brain that allows the eyes and head to turn swiftly either toward or away from the sights and sounds in our environment. Now a team of scientists at the Salk Institute for Biological Studies has shown that the superior colliculus does more than send out motor control commands to eye and neck muscles.

Two complementary studies, both led by Richard Krauzlis, Ph.D., an associate professor in the Systems Neurobiology Laboratory at the Salk Institute, have revealed that the superior colliculus performs supervisory functions in addition to the motor control it has long been known for. The results are published in the Aug. 6 and Sept. 17 issues of the Journal of Neuroscience.

"Beyond its classic role in motor control, the primate superior colliculus signals to other brain areas the location of behaviorally relevant visual objects by providing a 'neural pointer' to these objects," says Krauzlis.

The superior colliculus is currently under renewed scrutiny because recent findings have suggested that it does more than help orient the head and eyes toward something seen or heard. Results hinted that the superior colliculus might play a role in analyzing the current environment and deciding whether one specific aspect is worth paying closer attention to than another. Definitive proof, however, has been lacking.

The Salk scientists adopted a more "naturalistic" approach in their experiments to understand this role of the superior colliculus. Historically, physiological studies of eye movement control have relied on individual spots of light representing visual targets, but the real world is much more complex than a single dot on a computer screen. "For example, we can smoothly track a large airplane, with all its intricate visual details, by directing our gaze at its center," explains Ziad Hafed, Ph.D., Sloan-Swartz Fellow in the Systems Neurobiology Laboratory and lead author on both studies. "At night, we might only be able to see the strobe lights on the wing tips, but we are still able to track the object's invisible center."

Hafed designed a series of experiments where the subjects had to infer the invisible center of a visual target consisting of two peripheral features — much like the above airplane's strobe lights in the night sky — and track it for several seconds (http://www.cnl.salk.edu/~zhafed/tracking.mov) or fixate on a stationary dot while the peripheral features were moving back and forth (http://www.cnl.salk.edu/~zhafed/fixation.mov). (The green crosshair indicates the subject's eye position.)

For one study, the Salk researchers recorded the activity of single neurons in the superior colliculus while the subjects either fixated on the stationary dot or tracked the invisible center of the moving object. "The SC contains a topographic map of the visual space around us just as conventional maps mirror geographical areas," explains Hafed. "This allowed us to record either from peripheral neurons, representing one of the 'wing tips,' or central neurons, representing the foveal location of the invisible center that was tracked," he adds. (The fovea, which is responsible for sharp, central vision, is located in the center of the macular region of the retina, while peripheral vision occurs outside the center of our gaze.)

Surprisingly, the central neurons were the most active during this tracking behavior, despite the lack of a visual stimulus in the center of gaze. "These neurons highlighted the behavioral importance of the location of the invisible center, because it is this location that was the most important for the subjects to successfully track the object," says Krauzlis (http://www.cnl.salk.edu/~zhafed/rostral_neuron_track.mov). When the subjects ignored the invisible center, the same neurons were significantly less active (http://www.cnl.salk.edu/~zhafed/rostral_neuron_fix.mov).

As part of the second study, the Salk researchers, in collaboration with Laurent Goffart, Ph.D., a professor at the Institut de Neurosciences Cognitives de la Méditerranée in Marseille, France, temporarily inactivated a subset of superior colliculus neurons and analyzed the resulting changes in tracking performance. While the subjects still tracked well, their gaze consistently and predictably shifted away from the center, demonstrating clearly that the superior colliculus is essential for defining the object location (http://www.cnl.salk.edu/~zhafed/sample_inactivation.mov).

"By showing that the SC is not just a motor map, but also a map of behaviorally relevant object locations, our results provide a conceptual framework for understanding the role of the SC in non-motor functions such as visual attention and the functional links between motor control and sensory processing," says Hafed.

Zen Meditation reduces stress. Sort of..

2008-09-24T12:48:00.001+08:00

Turns out that Zen Meditation, a practice of detachment from an emotional state is more than just beneficial to your spiritual well-being, but also to your emotional well-being.

Step Back To Move Forward Emotionally, Study Suggests

ScienceDaily (Sep. 24, 2008) — When you're upset or depressed, should you analyze your feelings to figure out what's wrong? Or should you just forget about it and move on?

New research suggests a solution to these questions and to a related psychological paradox: Pocessing emotions is supposed to facilitate coping, but attempts to understand painful feelings often backfire and perpetuate or strengthen negative moods and emotions.*

The solution is not denial or distraction. According to University of Michigan psychologist Ethan Kross, the best way to move ahead emotionally is to analyze one's feelings from a psychologically distanced perspective.

With University of California, Berkeley, colleague Ozlem Ayduk, Kross has conducted a series of studies that provide the first experimental evidence of the benefits of analyzing depressive feelings from a psychologically distanced perspective.

"We aren't very good at trying to analyze our feelings to make ourselves feel better," said Kross, a faculty associate at the U-M Institute for Social Research (ISR) and an assistant professor of psychology. "It's an invaluable human ability to think about what we do, but reviewing our mistakes over and over, re-experiencing the same negative emotions we felt the first time around, tends to keep us stuck in negativity. It can be very helpful to take a sort of mental time-out, to sit back and try to review the situation from a distance."

This approach is widely associated with eastern philosophies such as Buddhism and Taoism, and with practices like Transcendental Meditation. But according to Kross, anyone can do it with a little practice.

"Using a thermostat metaphor is helpful to many people. When negative emotions become overwhelming, simply dial the emotional temperature down a bit in order to think about the problem rationally and clearly," he said.

Kross, who is teaching a class on self-control this fall at U-M, has published two papers on the topic this year. One provides experimental evidence that self-distancing techniques improve cardiovascular recovery from negative emotions. Another shows that the technique helps protect against depression.

In the July 2008 issue of Personality and Social Psychology Bulletin, Kross and Ayduk randomly assigned 141 participants to one of three groups that required them to focus (or not focus) on their feelings using different strategies in a guided imagery exercise that led them to recall an experience that made them feel overwhelmed by sadness and depression.

In the immersed-analysis condition, participants were told, "Go back to the time and place of the experience, and relive the situation as if it were happening to you all over again…try to understand the emotions that you felt as the experience unfolded…why did you have those feelings? What were the underlying causes and reasons?"

In the distanced-analysis condition, they were told, "Go back to the time and place of the experience…take a few steps back and move away from your experience…watch the experience unfold as if it were happening all over again to the distant you… try to understand the emotions that the distant you felt as the experience unfolded…why did he (she) have those feelings? What were the underlying causes and reasons?"

In the distraction condition, participants were asked to think about a series of non-emotional facts that were unrelated to their recalled depression experience. Among the statements: "Pencils are made with graphite" and "Scotland is north of England."

After the experience, participants completed a questionnaire asking how they felt at the moment, and wrote a stream-of-thought essay about their thoughts during the memory recall phase of the experiment.

Immediately after the session those who used the distanced-analysis approach reported lower levels of depression than those who used immersed-analysis, but not distraction. Thus distraction and distanced-analysis were found to be equally effective in the short-term. Participants then returned to the lab either one day or one week later. At that time, they were asked to think about the same sad or depressing experience, and their mood was reassessed.

Those who had used the distanced-analysis approach continued to show lower levels of depression than those who had used self-immersed analysis and distraction, providing evidence to support the hypothesis that distanced-analysis not only helps people cope with intense feelings adaptively in the short-term, but critically also helps people work-through negative experiences over time.

In a related study, published earlier this year in Psychological Science, Ayduk and Kross showed that participants who adopted a self-distanced perspective while analyzing feelings surrounding a time when they were angry showed smaller increases in blood pressure than those who used a self-immersed approach.

In future research, Kross plans to investigate whether self-distancing is helpful in coping with other types of emotions, including anxiety, and the best ways of teaching people how to engage in self-distanced analysis as they proceed with their lives, not just when they are asked to recall negative experiences in a laboratory setting.

*The studies were supported by funding from the National Institutes of Health.

Tree produces electricity

2008-09-23T22:18:00.001+08:00

Interesting. I was thinking along the lines of linking up 200 million trees as a power source though.. I wonder what the practicality in that is. Obviously the cost would be a killer, but if the price can drop?

Preventing Forest Fires With Tree Power: Sensor System Runs On Electricity Generated By Trees

ScienceDaily (Sep. 23, 2008) — MIT researchers and colleagues are working to find out whether energy from trees can power a network of sensors to prevent spreading forest fires.

What they learn also could raise the possibility of using trees as silent sentinels along the nation's borders to detect potential threats such as smuggled radioactive materials.

The U.S. Forest Service currently predicts and tracks fires with a variety of tools, including remote automated weather stations. But these stations are expensive and sparsely distributed. Additional sensors could save trees by providing better local climate data to be used in fire prediction models and earlier alerts. However, manually recharging or replacing batteries at often very hard-to-reach locations makes this impractical and costly.

The new sensor system seeks to avoid this problem by tapping into trees as a self-sustaining power supply. Each sensor is equipped with an off-the-shelf battery that can be slowly recharged using electricity generated by the tree. A single tree doesn't generate a lot of power, but over time the "trickle charge" adds up, "just like a dripping faucet can fill a bucket over time," said Shuguang Zhang, one of the researchers on the project and the associate director of MIT's Center for Biomedical Engineering (CBE).

The system produces enough electricity to allow the temperature and humidity sensors to wirelessly transmit signals four times a day, or immediately if there's a fire. Each signal hops from one sensor to another, until it reaches an existing weather station that beams the data by satellite to a forestry command center in Boise, Idaho.

Scientists have long known that trees can produce extremely small amounts of electricity. But no one knew exactly how the energy was produced or how to take advantage of the power.

In a recent issue of the Public Library of Science ONE, Zhang and MIT colleagues report the answer. "It's really a fairly simple phenomenon: An imbalance in pH between a tree and the soil it grows in," said Andreas Mershin, a postdoctoral associate at the CBE.¬ The first author of the paper is Christopher J. Love, an MIT senior in chemistry who has been working on the project since his freshman year.

To solve the puzzle of where the voltage comes from, the team had to test a number of theories - many of them exotic. That meant a slew of experiments that showed, among other things, that the electricity was not due to a simple electrochemical redox reaction (the type that powers the 'potato batteries' common in high school science labs,http://en.wikipedia.org/wiki/Lemon_battery). The team also ruled out the source as due to coupling to underground power lines, radio waves or other electromagnetic interference.

Testing of the wireless sensor network, which is being developed by Voltree Power, is slated to begin in the spring on a 10-acre plot of land provided by the Forest Service.

According to Love, who with Mershin has a financial interest in Voltree, the bioenergy harvester battery charger module and sensors are ready. "We expect that we'll need to instrument four trees per acre," he said, noting that the system is designed for easy installation by unskilled workers.

"Right now we're finalizing exactly how the wireless sensor network will be configured to use the minimum amount of power," he concluded.

The original experiments were funded by MagCap Engineering, LLC, through MIT's Undergraduate Research Opportunities Program.

Muscle stem cells exist! -.-

2008-09-19T13:53:00.002+08:00

And i remembered certain teachers telling me that muscle cells do not regenerate when lost. -.-

Muscle Stem Cell Identity Confirmed By Researchers

ScienceDaily (Sep. 19, 2008) — A single cell can repopulate damaged skeletal muscle in mice, say scientists at the Stanford University School of Medicine, who devised a way to track the cell's fate in living animals. The research is the first to confirm that so-called satellite cells encircling muscle fibers harbor an elusive muscle stem cell.

Identifying and isolating such a cell in humans would have profound therapeutic implications for disorders such as muscular dystrophy, injury and muscle wasting due to aging, disuse or disease.

"We were able to show at the single-cell level that these cells are true, multipotent stem cells," said Helen Blau, PhD, the Donald E. and Delia B. Baxter Professor of Pharmacology. "They fit the classic definition: they can both self-renew and give rise to specialized progeny." Blau is the senior author of the research, which will be published Sept. 17 in the online issue of Nature.

"We are thrilled with the results," said Alessandra Sacco, PhD, senior research scientist in Blau's laboratory and first author of the research. "It's been known that these satellite cells are crucial for the regeneration of muscle tissue, but this is the first demonstration of self-renewal of a single cell."

One-tenth of the body's mass is skeletal muscle. Satellite cells hang out between a muscle fiber and its thin, membrane-like sheath, waiting to spring into action when the fiber is damaged by exercise or trauma. When necessary, they begin to divide to make more specialized muscle cells. This property alone, however, doesn't qualify them as stem cells. That designation requires them to be able to also make copies of themselves for future use.

Although many researchers suspected that the satellite cell population included muscle stem cells, it was difficult to prove because not all satellite cells are identical. It was possible that one subpopulation was responsible for making lots of specialized muscle cells, while another replenished the supply of satellite cells.

This divide-and-conquer approach might be efficient, but doesn't have the same exciting clinical applications as identifying a true stem cell. However, analyzing the specific properties of a single cell is technically difficult, and usually requires hundreds of hours of painstaking microscopic analysis of tissue slices from many laboratory animals.

Sacco used a trick to overcome these hurdles. She isolated satellite cells from a mouse genetically engineered to express a glowing protein, luciferase, first identified in fireflies. She then used a novel imaging technique developed at Stanford to follow their fate after transplantation into living animals that did not express the protein. Because this non-invasive method allows repeated imaging of the same animal, fewer mice are needed for the research.

"To be able to detect the presence of the cells by bioluminescence was really a breakthrough," said Blau, the director of the Baxter Laboratory of Genetic Pharmacology. "It taught us so much more. We could see how the cells were responding, and really monitor their dynamics."

Sacco transplanted a single satellite cell expressing the glowing protein into the hind leg muscles of each of 144 mice; in six of the mice, these cells went on to proliferate and self-renew in the recipient's existing muscle. The relatively low success rate is most likely due in part to the fact that not all of the satellite cells are stem cells and also to the difficulty of keeping a lone cell alive and happy during isolation and transplantation.

The leg muscles of these six mice were repopulated with between 20,000 to 80,000 glowing progeny of the original satellite cell. Many cells made new muscle fibers or contributed to the recipient's muscle fibers. Most exciting, several of the glowing cells expressed cell markers specific only to satellite cells, indicating the original cell was also making more copies of itself and confirming that it was a stem cell.

In another set of experiments, Sacco and her colleagues transplanted between 10 and 500 satellite cells expressing the glowing protein into each mouse leg muscle. These cells also engrafted and proliferated extensively, increasing approximately a hundredfold in number after transplantation and a hundredfold more in response to muscle damage. They contributed extensively to the recipient's muscle, both by forming new fibers and by fusing with injured fibers. Furthermore, once the need for reinforcements had been met, the satellite stem cells stopped proliferating; that is, unlike tumor cells, the transplanted cells were responsive to local cues.

Finally, the researchers were able to induce a second and third wave of proliferation of the glowing satellite cells with repeated incidences of damage, showing that the stem cell function persisted over time.

"Now we can monitor the same mouse over time, and see how various treatments affect muscle regeneration," said Sacco. She and her collaborators are now turning their attention to isolating similar muscle stem cells from humans.

In addition to visually following the fate of the glowing cells, researchers can also use the intensity of the signal to assess the speed and strength of the stem cells' rescue response under a variety of conditions - an important feature that will allow researchers to directly compare the function of putative stem cells in a variety of injury and disease models.

"This technique provides the first quantitative way to compare stem cells in solid tissues," said Blau. "By providing a means of assessing the efficacy of a range of stem cell therapies in a variety of tissues, I think it will greatly impact not only the study of muscle stem cells in regenerative medicine, but also the stem cell field in general."

Sacco and Blau's Stanford collaborators included Regis Doyonnas, PhD, senior scientist; Peggy Kraft, research assistant; and Stefan Vitorovic, a research assistant and Stanford undergraduate student. The research was funded by the National Institutes of Health and by the Baxter Foundation.

where command economy fails and market economy succeeds

2008-09-18T16:02:00.003+08:00

Although i always believed that coorperation will always beat competition, but if you think about it, without competition, this would never have been possible..

From Xbox To T-cells: Borrowing Video Game Technology To Model Human Biology

Within a few minutes, the GPU-driven software developed by the Michigan Tech team provides a 3-D model of the human immune response to a TB infection. (Credit: Image courtesy of Michigan Technological University)
ScienceDaily (Sep. 18, 2008) — A team of researchers at Michigan Technological University is harnessing the computing muscle behind the leading video games to understand the most intricate of real-life systems.
Led by Roshan D'Souza, the group has supercharged agent-based modeling, a powerful but computationally massive forecasting technique, by using graphic processing units (GPUs), which drive the spectacular imagery beloved of video gamers. In particular, the team aims to model complex biological systems, such as the human immune response to a tuberculosis bacterium.
Computer science student Mikola Lysenko, who wrote the software, demonstrates. On his computer monitor, a swarm of bright green immune cells surrounds and contains a yellow TB germ. These busy specks look like 3D-animations from a PBS documentary, but they are actually virtual T-cells and macrophages—the visual reflection of millions of real-time calculations.
"I've been asked if we ran this on a supercomputer or if it's a movie," says D'Souza, an assistant professor of mechanical engineering–engineering mechanics. He notes that their model is several orders of magnitude faster than state-of-the art agent modeling toolkits. According to the researchers, however, this current effort is small potatoes.
"We can do it much bigger," says D'Souza. "This is nowhere near as complex as real life." Next, he hopes to model how a TB infection could spread from the lung to the patient's lymphatic system, blood and vital organs.
Dr. Denise Kirschner, of the University of Michigan in Ann Arbor, developed the TB model and gave it to D'Souza's team, which programmed it into a graphic processing unit. Agent-based modeling hasn't replaced test tubes, she says, but it is providing a powerful new tool for medical research.
Computer models offer significant advantages. "You can create a mouse that's missing a gene and see how important that gene is," says Kirschner. "But with agent-based modeling, we can knock out two or three genes at once." In particular, agent-based modeling allows researchers to do something other methodologies can't: virtually test the human response to serious insults, such as injury and infection.
While agent-based modeling may never replace the laboratory entirely, it could reduce the number of dead-end experiments. "It really helps scientists focus their thinking," Kirschner said. "The limiting factor has been that these models take a long time to run, and [D'Souza's] method works very quickly and efficiently," she said.
Dr. Gary An, a surgeon specializing in trauma and critical care in Northwestern University's Feinberg School of Medicine, is a pioneer in the use of agent-based modeling to understand another matter of life and death: sepsis. With billions of agents, including a variety of cells and bacteria, these massive, often fatal infections have been too complex to model economically on a large scale, at least until now.
"The GPU technology may make this possible," said An. "This is very interesting stuff, and I'm excited about it."
About agent-based modeling
Agent-based modeling simulates the behaviors of complex systems. It can be used to predict the outcomes of anything from pandemics to the price of pork bellies. It is, as the name suggests, based on individual agents: e.g., sick people and well people, predators and prey, etc. It applies rules that govern how those agents behave under various conditions, sets them loose, and tracks how the system changes over time. The outcomes are unpredictable and can be as surprising as real life.
Agent-based modeling has been around since the 1950s, but the process has always been handicapped by a shortage of computing power. Until recently, the only way to run large models quickly was on multi-million-dollar supercomputers, a costly proposition.
D'Souza's team sidestepped the problem by using GPUs, which can run models with tens of millions of agents with blazing speed.
"With a $1,400 desktop, we can beat a computing cluster," says D'Souza. "We are effectively democratizing supercomputing and putting these powerful tools into the hands of any researcher. Every time I present this research, I make it a point to thank the millions of video gamers who have inadvertently made this possible."
The Tech team also looks forward to applying their model in other ways. "We can do very complex ecosystems right now," said Ryan Richards, a computer science senior. "If you're looking at epidemiology, we could easily simulate an epidemic in the US, Canada and Mexico."
"GPUs are very difficult to program. It is completely different from regular programming," said D'Souza, who deflects credit to the students. "All of this work was done by CS undergrads, and they are all from Michigan Tech. I've had phenomenal success with these guys—you can't put a price tag on it."
D'Souza's work was supported by a grant from the National Science Foundation. In addition to Lysenko and Richards, computer science undergraduate Nick Smolinske also contributed to the research.

I can't believe this

2008-09-16T20:40:00.003+08:00

ok, i don't wanna do this, but i just feel like the school just plain wanted to mock me. -.-

"some of the year 6 students have been requested to attend a tea session by "

ok, so i didn't get selected, fine. even though 51 of the students in the level were, fine. i'm in the lower 37 of the batch, fine. but you really didn't have to drive in the final nail by inviting 2 students who are not even in the school anymore. am i that unwanted? "oh i'd rather place the name of someone who can't even make it anymore than to let you go in"? to be placed in the same category as ?

i probably wouldn't be interested in the talk? so can someone tell me why more than 7 students from the B class are invited to a tea session on clinical sciences? why in the world would anyone of them be interested in MBBS-Phd scholarship?

i guess it's time for me to be disappointed in the school as well? or maybe i should take back whatever that i have ever given to the school?

So we google what we hear…

2008-09-15T22:33:00.001+08:00

Scientists Watch As Listener's Brain Predicts Speaker's Words

ScienceDaily (Sep. 15, 2008) — Scientists at the University of Rochester have shown for the first time that our brains automatically consider many possible words and their meanings before we've even heard the final sound of the word.

Previous theories have proposed that listeners can only keep pace with the rapid rate of spoken language—up to 5 syllables per second—by anticipating a small subset of all words known by the listener, much like Google search anticipates words and phrases as you type. This subset consists of all words that begin with the same sounds, such as "candle", "candy," and "cantaloupe," and makes the task of understanding the specific word more efficient than waiting until all the sounds of the word have been presented.

But until now, researchers had no way to know if the brain also considers the meanings of these possible words. The new findings are the first time that scientists, using an MRI scanner, have been able to actually see this split-second brain activity. The study was a team effort among former Rochester graduate student Kathleen Pirog Revill, now a postdoctoral researcher at Georgia Tech, and three faculty members in the Department of Brain and Cognitive Sciences at the University of Rochester.

"We had to figure out a way to catch the brain doing something so fast that it happens literally between spoken syllables," says Michael Tanenhaus, the Beverly Petterson Bishop and Charles W. Bishop Professor. "The best tool we have for brain imaging of this sort is functional MRI, but an fMRI takes a few seconds to capture an image, so people thought it just couldn't be done."

But it could be done. It just took inventing a new language to do it.

With William R. Kenan Professor Richard Aslin and Professor Daphne Bavelier, Pirog Revill focused on a tiny part of the brain called "V5," which is known to be activated when a person sees motion. The idea was to teach undergraduates a set of invented words, some of which meant "movement," and then to watch and see if the V5 area became activated when the subject heard words that sounded similar to the ones that meant "movement."

For instance, as a person hears the word "kitchen," the Rochester team would expect areas of the brain that would normally become active when a person thought of words like "kick" to momentarily show increased blood flow in an fMRI scan. But the team couldn't use English words because a word as simple as "kick" has so many nuances of meaning. To one person it might mean to kick someone in anger, to another it might mean to be kicked, or to kick a winning goal. The team had to create a set of words that had similar beginning syllables, but with different ending syllables and distinct meanings—one of which meant motion of the sort that would activate the V5 area.

The team created a computer program that showed irregular shapes and gave the shapes specific names, like "goki." They also created new verb words. Some, like "biduko" meant "the shape will move across the screen," whereas some, like "biduka," meant the shape would just change color.

After a number of students learned the new words well enough, the team tested them as they lay in an fMRI scanner. The students would see one of the shapes on a monitor and hear "biduko," or "biduka." Though only one of the words actually meant "motion," the V5 area of the brain still activated for both, although less so for the color word than for the motion word. The presence of some activation to the color word shows that the brain, for a split-second, considered the motion meaning of both possible words before it heard the final, discriminating syllable—ka rather than ko.

"Frankly, we're amazed we could detect something so subtle," says Aslin. "But it just makes sense that your brain would do it this way. Why wait until the end of the word to try to figure out what its meaning is? Choosing from a little subset is much faster than trying to match a finished word against every word in your vocabulary."

The Rochester team is already planning more sophisticated versions of the test that focus on other areas of the brain besides V5—such as areas that activate for specific sounds or touch sensations. Bavelier says they're also planning to watch the brain sort out meaning when it is forced to take syntax into account. For instance, "blind venetian" and "venetian blind" are the same words but mean completely different things. How does the brain narrow down the meaning in such a case? How does the brain take the conversation's context into consideration when zeroing in on meaning?

"This opens a doorway into how we derive meaning from language," says Tanenhaus. "This is a new paradigm that can be used in countless ways to study how the brain responds to very brief events. We're very excited to see where it will lead us."

http://www.sciencedaily.com/releases/2008/09/080911140815.htm

stupid things done by stupid people

2008-09-13T15:23:00.002+08:00

they hack into a potential black hole/antimatter making machine, play around with it and say that the security is lacking? that's like a random person sneaking into a nuclear powerplant, playing with all the controls, and blaming it on the owner for not having good security. -.-

article goes like this:

As the first particles began circulating in the Large Hadron Collider (LHC) this week, a group of hackers calling themselves the "Greek Security Team" penetrated computer systems inside CERN's Geneva, Switzerland, facility, where the world's biggest particle accelerator is housed, the Telegraph.co.uk reported today.

The hackers were reportedly targeting the Compact Muon Solenoid Experiment (CMS), a device in Cessy, France, built to monitor a wide range of particles and phenomena produced in high-energy collisions in the LHC. The 12,500-ton detector's different layers (weighing, according to CERN, as much as 30 jumbo jets or 2,500 African elephants) stop and measure the different particles, and use this data to form a picture of events at the heart of the collision. Scientists plan to use the info to help answer questions about what the university is really made of and what forces act within it.

On Wednesday, as the LHC was revving up, CMS engineers searched computers for half a dozen files uploaded by the hackers. The interlopers accessed the computer that monitors the CMS software system as the CMS collects data during particle collisions.

CERN scientists says no harm was done but that the break-in raises security concerns, given that intruders were able to penetrate so close to the CMS's computer control system, according to the Telegraph.co.uk. In other words, the hackers came this close to being able to switch off some CMS controls.

"We are 2600 - dont mess with us. (sic)," the group warned in a message to CERN engineers. The "2600" refers to a U.S. magazine published quarterly that appeals to the hackers worldwide by publishing technical information about telephone switching systems, the Internet and other technology, as well as computer-related news. The mindset behind the sharing of this information is to find vulnerabilities in the computer systems used by government and industry and force them to improve their security by exploiting their flaws. In fact, 2600 has become a brand in the hacker world: in addition to 2600: The Hacker Quarterly; an organization known as 2600 hosts hacker conferences and there's even a film company of that name that's made a documentary on legendary hacker Kevin Mitnick.

Given the huge interest not to mention the enormity of the LHC's task, it's "highly disturbing" that hackers were able to compromise and change data on its Web site, Graham Cluley, security researcher with Sophos Plc (a security services firm based in both the UK and Burlington, Mass.) wrote in his blog today. "Theoretically," he noted, "hackers could have planted malicious code which could have stolen identities or installed malware onto the computers of millions of web visitors."

http://www.sciam.com/blog/60-second-science/post.cfm?id=hackers-attack-large-hadron-collide-2008-09-12

Smart people? (not me)

2008-09-03T21:36:00.001+08:00

So.. are smart people smart because they have faster impulses, or because they have more efficient ones?

High-Aptitude Minds: The Neurological Roots of Genius

Researchers are finding clues to the basis of brilliance in the brain

By Christian Hoppe and Jelena Stojanovic

Within hours of his demise in 1955, Albert Einstein's brain was salvaged, sliced into 240 pieces and stored in jars for safekeeping. Since then, researchers have weighed, measured and otherwise inspected these biological specimens of genius in hopes of uncovering clues to Einstein's spectacular intellect.

Their cerebral explorations are part of a century-long effort to uncover the neural basis of high intelligence or, in children, giftedness. Traditionally, 2 to 5 percent of kids qualify as gifted, with the top 2 percent scoring above 130 on an intelligence quotient (IQ) test. (The statistical average is 100. See the box on the opposite page.) A high IQ increases the probability of success in various academic areas. Children who are good at reading, writing or math also tend to be facile at the other two areas and to grow into adults who are skilled at diverse intellectual tasks [see "Solving the IQ Puzzle," by James R. Flynn; Scientific American Mind, October/November 2007].

Most studies show that smarter brains are typically bigger—at least in certain locations. Part of Einstein's parietal lobe (at the top of the head, behind the ears) was 15 percent wider than the same region was in 35 men of normal cognitive ability, according to a 1999 study by researchers at McMaster University in Ontario. This area is thought to be critical for visual and mathematical thinking. It is also within the constellation of brain regions fingered as important for superior cognition. These neural territories include parts of the parietal and frontal lobes as well as a structure called the anterior cingulate.

But the functional consequences of such enlargement are controversial. In 1883 English anthropologist and polymath Sir Francis Galton dubbed intelligence an inherited feature of an efficiently functioning central nervous system. Since then, neuroscientists have garnered support for this efficiency hypothesis using modern neuroimaging techniques. They found that the brains of brighter people use less energy to solve certain prob lems than those of people with lower aptitudes do.

In other cases, scientists have observed higher neuronal power consumption in individuals with superior mental capacities. Musical prodigies may also sport an unusually energetic brain [see box on page 67]. That flurry of activity may occur when a task is unusually challenging, some researchers speculate, whereas a gifted mind might be more efficient only when it is pondering a relatively painless puzzle.

Despite the quest to unravel the roots of high IQ, researchers say that people often overestimate the significance of intellectual ability [see "Coaching the Gifted Child," by Christian Fischer]. Studies show that practice and perseverance contribute more to accomplishment than being smart does.

Size Matters
In humans, brain size correlates, albeit somewhat weakly, with intelligence, at least when researchers control for a person's sex (male brains are bigger) and age (older brains are smaller). Many modern studies have linked a larger brain, as measured by magnetic resonance imaging, to higher intellect, with total brain volume accounting for about 16 percent of the variance in IQ. But, as Einstein's brain illustrates, the size of some brain areas may matter for intelligence much more than that of others does.

In 2004 psychologist Richard J. Haier of the University of California, Irvine, and his colleagues reported evidence to support the notion that discrete brain regions mediate scholarly aptitude. Studying the brains of 47 adults, Haier's team found an association between the amount of gray matter (tissue containing the cell bodies of neurons) and higher IQ in 10 discrete regions, including three in the frontal lobe and two in the parietal lobe just behind it. Other scientists have also seen more white matter, which is made up of nerve axons (or fibers), in these same regions among people with higher IQs. The results point to a widely distributed—but discrete—neural basis of intelligence.

The neural hubs of general intelligence may change with age. Among the younger adults in Haier's study—his subjects ranged in age from 18 to 84—IQ correlated with the size of brain regions near a central structure called the cingulate, which participates in various cognitive and emotional tasks. That result jibed with the findings, published a year earlier, of pediatric neurologist Marko Wilke, then at Cincinnati Children's Hospital Medical Center, and his colleagues. In its survey of 146 children ages five to 18 with a range of IQs, the Cincinnati group discovered a strong connection between IQ and gray matter volume in the cingulate but not in any other brain structure the researchers examined.

Scientists have identified other shifting neural patterns that could signal high IQ. In a 2006 study child psychiatrist Philip Shaw of the National Institute of Mental Health and his colleagues scanned the brains of 307 children of varying intelligence multiple times to determine the thickness of their cerebral cortex, the brain's exterior part. They discovered that academic prodigies younger than eight had an unusually thin cerebral cortex, which then thickened rapidly so that by late childhood it was chunkier than that of less clever kids. Consistent with other studies, that pattern was particularly pronounced in the frontal brain regions that govern rational thought processes.

The brain structures responsible for high IQ may vary by sex as well as by age. A recent study by Haier, for example, suggests that men and women achieve similar results on IQ tests with the aid of different brain regions. Thus, more than one type of brain architecture may underlie high aptitude.

Low Effort Required
Meanwhile researchers are debating the functional consequences of these structural findings. Over the years brain scientists have garnered evidence supporting the idea that high intelligence stems from faster information processing in the brain. Underlying such speed, some psychologists argue, is unusually efficient neural circuitry in the brains of gifted individuals.

Experimental psychologist Werner Krause, formerly at the University of Jena in Germany, for example, has proposed that the highly gifted solve puzzles more elegantly than other people do: they rapidly identify the key information in them and the best way to solve them. Such people thereby make optimal use of the brain's limited working memory, the short-term buffer that holds items just long enough for the mind to process them.

Starting in the late 1980s, Haier and his colleagues have gathered data that buttress this so-called efficiency hypothesis. The researchers used positron-emission tomography, which measures glucose metabolism of cells, to scan the brains of eight young men while they performed a nonverbal abstract reasoning task for half an hour. They found that the better an individual's performance on the task, the lower the metabolic rate in widespread areas of the brain, supporting the notion that efficient neural processing may underlie brilliance. And in the 1990s the same group observed the flip side of this phenomenon: higher glucose metabolism in the brains of a small group of subjects who had below-average IQs, suggesting that slower minds operate less economically.

More recently, in 2004 psychologist Aljoscha Neubauer of the University of Graz in Austria and his colleagues linked aptitude to diminished cortical activity after learning. The researchers used electroencephalography (EEG), a technique that detects electrical brain activity at precise time points using an array of electrodes affixed to the scalp, to monitor the brains of 27 individuals while they took two reasoning tests, one of them given before test-related training and the other after it. During the second test, frontal brain regions—many of which are involved in higher- order cognitive skills—were less active in the more intelligent individuals than in the less astute subjects. In fact, the higher a subject's mental ability, the bigger the dip in cortical activation between the pretraining and posttraining tests, suggesting that the brains of brighter individuals streamline the processing of new information faster than those of their less intelligent counterparts do.

The cerebrums of smart kids may also be more efficient at rest, according to a 2006 study by psychologist Joel Alexander of Western Oregon University and his colleagues. Using EEG, Alexander's team found that resting eight- to 12-hertz alpha brain waves were significantly more powerful in 30 adolescents of average ability than they were in 30 gifted adolescents, whose alpha-wave signal resembled those of older, college-age students. The results suggest that gifted kids' brains use relatively little energy while idle and in this respect resemble more developmentally advanced human brains.

Some researchers speculate that greater energy efficiency in the brains of gifted individuals could arise from increased gray matter, which might provide more resources for data processing, lessening the strain on the brain. But others, such as economist Edward Miller, formerly of the University of New Orleans, have proposed that the efficiency boost could also result from thicker myelin, the substance that insulates nerves and ensures rapid conduction of nerve signals. No one knows if the brains of the quick-witted generally contain more myelin, although Einstein's might have. Scientists probing Einstein's brain in the 1980s discovered an unusual number of glia, the cells that make up myelin, relative to neurons in one area of his parietal cortex.

Hardworking Minds
And yet gifted brains are not always in a state of relative calm. In some situations, they appear to be more energetic, not less, than those of people of more ordinary intellect. What is more, the energy-gobbling brain areas roughly correspond to those boasting more gray matter, suggesting that the gifted may simply be endowed with more brainpower in this intelligence network.

In a 2003 trial psychologist Jeremy Gray, then at Washington University in St. Louis, and his colleagues scanned the brains of 48 individuals using functional MRI, which detects neural activity by tracking the flow of oxygenated blood in brain tissue, while the subjects completed hard tasks that taxed working memory. The researchers saw higher levels of activity in prefrontal and parietal brain regions in the participants who had received high scores on an intelligence test, as compared with low scorers.

In a 2005 study a team led by neuroscientist Michael O'Boyle of Texas Tech University found a similar brain activity pattern in young male math geniuses. The researchers used fMRI to map the brains of mathematically gifted adolescents while they mentally rotated objects to try to match them to a target item. Compared with adolescent boys of average math ability, the brains of the mathematically talented boys were more metabolically active—and that activity was concentrated in the parietal lobes, the frontal cortex and the anterior cingulate.

A year later biologist Kun Ho Lee of Seoul National University in Korea similarly linked elevated activity in a frontoparietal neural network to superior intellect. Lee and his co-workers measured brain activity in 18 gifted adolescents and 18 less intelligent young people while they performed difficult reasoning tasks. These tasks, once again, excited activity in areas of the frontal and parietal lobes, including the anterior cingulate, and this neural commotion was significantly more intense in the gifted individuals' brains.

No one is sure why some experiments indicate that a bright brain is a hardworking one, whereas others suggest it is one that can afford to relax. Some, such as Haier—who has found higher brain metabolic rates in more astute individuals in some of his studies but not in others—speculate one reason could relate to the difficulty of the tasks. When a problem is very complex, even a gifted person's brain has to work to solve it. The brain's relatively high metabolic rate in this instance might reflect greater engagement with the task. If that task was out of reach for someone of average intellect, that person's brain might be relatively inactive because of an inability to tackle the problem. And yet a bright individual's brain might nonetheless solve a less difficult problem efficiently and with little effort as compared with someone who has a lower IQ.

Perfection from Practice
Whatever the neurological roots of genius, being brilliant only increases the probability of success; it does not ensure accomplishment in any endeavor. Even for academic achievement, IQ is not as important as self-discipline and a willingness to work hard.

University of Pennsylvania psychologists Angela Duckworth and Martin Seligman examined final grades of 164 eighth-grade students, along with their admission to (or rejection from) a prestigious high school. By such measures, the researchers determined that scholarly success was more than twice as dependent on assessments of self-discipline as on IQ. What is more, they reported in 2005, students with more self-discipline—a willingness to sacrifice short-term pleasure for long-term gain—were more likely than those lacking this skill to improve their grades during the school year. A high IQ, on the other hand, did not predict a climb in grades.

A 2007 study by Neubauer's team of 90 adult tournament chess players similarly shows that practice and experience are more important to expertise than general intelligence is, although the latter is related to chess-playing ability. Even Einstein's spectacular success as a mathematician and a physicist cannot be attributed to intellectual prowess alone. His education, dedication to the problem of relativity, willingness to take risks, and support from family and friends probably helped to push him ahead of any contemporaries with comparable cognitive gifts.

Note: This article was originally published with the title, "High-Aptitude Minds".

Quiz for everyone!

2008-09-03T18:29:00.001+08:00

If you ever swim or paddle upstream, you will notice two things. First, a river's speed varies a lot. Second, those variations should cause you to pull harder when you hit rapidly flowing water. If you don't, you will simply make no progress. This puzzle replaces your muscles with a motor, but still asks you to figure out how to trade off energy for time.

Here are the facts:

• You want to go 72 kilometers (km) upriver.
• The first 24 km has a downstream speed of 7 kilometers per hour (kmh).
• The next 18 km has a downstream speed of 2 kmh.
• The last 30 km has a downstream speed of 0 kmh (the river becomes a lake).

You have an electric motor with three settings that can push the boat forward at a water speed of:

• 5 kmh using 1 kilowatt (kW) of power
• 10 kmh using 3 kW
• 15 kmh using 5 kW

Recall that land speed = water speed - downstream speed.
So, for example, if your water speed upstream is 15 kmh but the river has a downstream speed of 2 kmh, then your land speed is 13 kmh.

Warm-up:
Suppose you went full speed on all legs of the voyage. How long would the journey take and how much energy would you expend?

Solution to Warm-Up

Here now are the challenges for you.

1. What is the least energy you could use to make the entire trip, assuming you were in absolutely no rush? How would you do it?

Hint: On a lake, you would use the slowest speed, but this may not hold on all parts of the trip.

2. Suppose you have a battery that holds 30 kWh. How could you arrange to arrive as quickly as possible without consuming more than 30 kWh?

Click here for the solution

ABOUT THE AUTHOR(S)
Dennis Shasha is at the Courant Institute of Mathematical Sciences, New York University. His most recent puzzle book, Puzzles for Programmers and Pros, was published in 2007 by John Wiley and Sons/Wrox.

http://www.sciam.com/article.cfm?id=puzzling-adventures-river-run-sept-08&sc=rss

Putting known concepts together..

2008-09-01T12:54:00.001+08:00

I know that changing levels of UV exposure would result in changes in melanin levels. I also know that heavy exposure to UV can cause massive extinction. But I couldn't put the 2 together… It's not even rocket science. -.-

Spores may fill gap in atmospheric records.

A gaping hole in atmospheric scientists' records could soon be filled thanks to the spores of a primitive moss.

Led by Barry Lomax, at the University of Nottingham, UK, a team of researchers has devised a way to reconstruct past levels of ozone by measuring levels of the chemicals that act as protective 'sunscreens' in the spores.

Lomax had previously used this technique to try to find out whether massive exposure to UV radiation caused the Permian extinction around 250 million years ago, after volcanic eruptions triggered a massive loss of ozone (see 'Plant pollen records ozone holes'). Although that attempt failed because of a lack of suitable fossils, the technique may end up answering wider questions about the evolution of our atmosphere.

Until now, atmospheric scientists have been limited to ozone measurements made by satellites that date back only to the late 1970s and data from ground-based spectrophotometers going back to the 1920s. Lomax's team say that the levels of ultraviolet-absorbing compounds in plant spores can show how much of this radiation they were exposed to, and hence show what the ozone levels were in the atmosphere millennia ago.

"At the moment it's very much an unknown how ozone has changed over recent and geological time," says Lomax. "[This method] could help address issues of climate change and whether we're seeing recovery [in the ozone layer] now, or whether it's natural variation."

The story's in the spores

In a paper published online by Nature Geoscience Lomax details how spores can be use as a 'biological proxy' for ozone levels. Plants subjected to increased levels of UV-B radiation make more of the natural phenolic 'sunscreen' compounds that absorb the potentially harmful rays¹.

By analysing the concentration of these UV-absorbing compounds in the walls of spores from herbarium collections, it is possible to work out how much radiation they have been subjected to. From this it is possible to work out how much ozone was in the atmosphere between the plant and the Sun, says Lomax.

Traces of these compounds are even preserved in fossils. "We certainly should be able to go back into the Tertiary, about 55 million years ago, without a problem," says Lomax. "It will work on fossil spores provided they haven't been heated to over 200 ºC."

The paper details analysis of spores of clubmosses from high- and low-latitude locations, which were found to contain concentrations of UV-absorbing compounds that strongly correlate with known historical changes in UV-B levels. Spores from Ecuador, where there have been no historic changes in UV-B, showed no change in 'sunscreen' concentrations over the same time period.

Using spores from Greenland, Lomax reconstructed historical ozone levels between 1907 and 1993 and found strong correlations between their reconstructions and atmospheric ozone measurements made within this period.

"It would be extremely interesting if we could reconstruct the UV climates in the past," says Geir Braathen, an atmospheric chemist and senior scientific officer at the World Meteorological Organization in Geneva, Switzerland. "It would be very interesting to see how the ozone layer has developed."

Lomax now hopes to do just that. "We're planning to look through to the Holocene and the Quaternary to see just how far back we can take it," he says.

References
- Lomax, B. et al. Nature Geosci. advance online publiction doi:10.1038/ngeo278 (2008)

http://www.nature.com/news/2008/080831/full/news.2008.1071.html?s=news_rss

free will (the actual post)

2008-08-21T16:02:00.002+08:00

ok i've been doing alot of random articles with a very small amount of actual reflection. mostly because there really isn't much to think about.

this article has a couple of flaws that fails. but, there is one thing it did cause me to think about. first and most importantly, do we have free wills? most people on the road would prefer to think that we do. otherwise, who's responsibility is it to preserve order in society? the scientists would prefer to think that we don't. cos, who's making this decisions then? then the question of a soul comes in, and what it's powered by.
our brain, as far as scientists know, is basically a couple hundred million neurons firing at indeterminable times. can such a thing create a free will? how does a couple trillion electrical impulses translate to, say anger? or happiness? or even an M16? if we see our brain as a series of on and off switches, then we can never say that we're anymore different than that of a computer. one that receives information and gives an output. if that's the case, then why should we be blamed for anything said or done by us? we couldn't have made another choice could we? if time were to go back, we would still have to make the same decision. that's cos the input is the same. however, if we were to have a free will, all is fine and well, except that it just doesn't tie up fundamentally with how our brain works. does it become more than a sum of its parts beyond a certain level? what is that level? an ant makes a fixed action pattern, even though some is learnt. we have free will. but really, how different are we from an ant, apart from the complexity? can we say the ant follows a pheromone trail by instinct, or is it their mode of communication? can we react to a song by instinct too?
to me, a brain is a collection of neurons, that receive, store, and sorts information. these information will always be accessed again and again as reference to assign priority to each new information we receive, ones with higher priority, of course, gets stored and the rest discarded. over time, a collection of these memories make up our habits and ultimately, our personalities. now, how does this result in whatever we see now and what our decisions are? very simply, our minds use the stored information, also known as memories, to determine our next step. so, for example, me thinking of this topic is a decision by referencing previous memories, collectively ranking philosophy as a higher priority than say, marking my assessments. makes sense don't you think? that's why people very close to you can actually double guess your actions and even your words. if something in the lab were to break, my supervisor would automatically decide it's probably me. that's also why experts can easily read your body behavior and thus, guess what you plan to do. everything fits right?
i have made a previous speech on why rules on morality can be kept and followed even though they might not be absolute. now, however, a new problem is up. if our responses are truly a response to a stimuli, then why should i be blamed for what happened as a result of my behavior? it's not like i have a choice right? my response is just a fixed pattern from a stimulus right? so if time rewinds, i would still make the same choice. this is quite difficult to put together. really, how can i blame someone who cannot attempt to do it intentionally? this is bad for society. who can we blame for a murder? should we blame the parents who brought up the murderer? do the parents have a choice to bring the murderer up in any other way? can i blame a computer for translating my documents into greek? it was simply programmed wrongly. blame the programmer? if the programmer was another computer, can i blame it? what to do?
i pondered over this for awhile, considering that perhaps, we can choose what the priorities are when we rank each information. that doesn't work. what are our priorities? the answers to these question is based on a previous priority and so forth. in the end, it's "turtles all the way down". right at the bottom, it's still the floor. so, how? very tough question.

i finally found the answer. it's not an assuring one, but it works. up till now, i've said that everything we aim for, is simply for advancement of society. this is just the same. if i were to blame you for the actions you did, other people will receive a stimulus that tells them that this specific action would result in pain or unpleasantness in general. to avoid unpleasantness, this stimulus would be registered as high priority. thus, people will avoid it. as such, this would contribute to society. thus, the idea of blame is not accountability, but a warning that such an action will result in undesirable effects. the aim of avoidance is based on a very shortsighted goal, but, on the whole, it serves to reduce these actions. so why do you want to avoid doing something wrong, because doing so would cause you to be blamed. simple as that.
not the most assuring of concepts. in fact, many would hate it. they not only lose the only feeling of control over their lives: free will, but much more, their perceived importance in society. it's not that you are blamed because you could choose to do otherwise, but that you're blamed to prevent it from happening again. once again, man ends up as a tiny gear in the grand scheme of chance.

P.S. grand scheme of chance IS an oxymoron.

free will?

2008-08-21T15:59:00.000+08:00

Free Will vs. the Programmed Brain

If our actions are determined by prior events, then do we have a choice about anything—or any responsibility for what we do?

By Shaun Nichols

Many scientists and philosophers are convinced that free will doesn’t exist at all. According to these skeptics, everything that happens is determined by what happened before—our actions are inevitable consequences of the events leading up to the action—and this fact makes it impossible for anyone to do anything that is truly free. This kind of anti-free will stance stretches back to 18th century philosophy, but the idea has recently been getting much more exposure through popular science books and magazine articles. Should we worry? If people come to believe that they don’t have free will, what will the consequences be for moral responsibility?

In a clever new study, psychologists Kathleen Vohs at the University of Minnesota and Jonathan Schooler at the University of California at Santa Barbara tested this question by giving participants passages from The Astonishing Hypothesis, a popular science book by Francis Crick, a biochemist and Nobel laureate (as co-discoverer, with James Watson, of the DNA double helix). Half of the participants got a passage saying that there is no such thing as free will. The passage begins as follows: “‘You,’ your joys and your sorrows, your memories and your ambitions, your sense of personal identity and free will, are in fact no more than the behavior of a vast assembly of nerve cells and their associated molecules. Who you are is nothing but a pack of neurons.”
The passage then goes on to talk about the neural basis of decisions and claims that “…although we appear to have free will, in fact, our choices have already been predetermined for us and we cannot change that.” The other participants got a passage that was similarly scientific-sounding, but it was about the importance of studying consciousness, with no mention of free will.

After reading the passages, all participants completed a survey on their belief in free will. Then comes the inspired part of the experiment. Participants were told to complete 20 arithmetic problems that would appear on the computer screen. But they were also told that when the question appeared, they needed to press the space bar, otherwise a computer glitch would make the answer appear on the screen, too. The participants were told that no one would know whether they pushed the space bar, but they were asked not to cheat.

The results were clear: those who read the anti-free will text cheated more often! (That is, they pressed the space bar less often than the other participants.) Moreover, the researchers found that the amount a participant cheated correlated with the extent to which they rejected free will in their survey responses.

Varieties of Immorality

Philosophers have raised questions about some elements of the study. For one thing, the anti-free will text presents a bleak worldview, and that alone might lead one to cheat more in such a context (“OMG, if I’m just a pack of neurons, I have much bigger things to worry about than behaving on this experiment!”). It might be that one would also find increased cheating if you gave people a passage arguing that all sentient life will ultimately be destroyed in the heat death of the universe.

On the other hand, the results fit with what some philosophers had predicted. The Western conception idea of free will seems bound up with our sense of moral responsibility, guilt for misdeeds and pride in accomplishment. We hold ourselves responsible precisely when we think that our actions come from free will. In this light, it’s not surprising that people behave less morally as they become skeptical of free will. Further, the Vohs and Schooler result fits with the idea that people will behave less responsibly if they regard their actions as beyond their control. If I think that there’s no point in trying to be good, then I’m less likely to try.

Even if giving up on free will does have these deleterious effects, one might wonder how far they go. One question is whether the effects extend across the moral domain. Cheating in a psychology experiment doesn’t seem too terrible. Presumably the experiment didn’t also lead to a rash of criminal activity among those who read the anti-free will passage. Our moral revulsion at killing and hurting others is likely too strong to be dismantled by reflections about determinism. It might well turn out that other kinds of immoral behavior, like cheating in school, would be affected by the rejection of free will, however.

Is the Effect Permanent?

Another question is how long-lived the effect is. The Vohs and Schooler study suggests that immediately after people are made skeptical of free will, they cheat more. But what would happen if those people were brought back to the lab two weeks later? We might find that they would continue to be skeptical of free will but they would no longer cheat more.

There is no direct evidence on this question, but there is recent evidence on a related issue. Philosopher Hagop Sarkissian of the City Univeristy of New York and colleagues had people from Hong Kong, India, Colombia and the U.S. complete a survey on determinism and moral responsibility. Determinism was described in nontechnical terms, and participants were asked (in effect): whether our universe was a deterministic universe and whether people in a deterministic universe are morally responsible for their actions.

Across cultures, they found that most people said that our universe is not deterministic and also that people in the deterministic universe are not responsible for their actions. Although that isn’t particularly surprising—people want to believe they have free will—something pretty interesting emerges when you look at the smaller group of people who say that our universe is deterministic. Across all of the cultures, this substantial minority of free will skeptics were also much more likely to say that people are responsible even if determinism is true. One way to interpret this finding is that if you come to believe in determinism, you won’t drop your moral attitudes. Rather, you’ll simply reverse your view that determinism rules out moral responsibility.

Many philosophers and scientists reject free will and, while there has been no systematic study of the matter, there’s currently little reason to think that the philosophers and scientists who reject free will are generally less morally upright than those who believe in it. But this raises yet another puzzling question about the belief in free will. People who explicitly deny free will often continue to hold themselves responsible for their actions and feel guilty for doing wrong. Have such people managed to accommodate the rest of their attitudes to their rejection of free will? Have they adjusted their notion of guilt and responsibility so that it really doesn’t depend on the existence of free will? Or is it that when they are in the thick of things, trying to decide what to do, trying to do the right thing, they just fall back into the belief that they do have free will after all?

it appears that this idea also exists in bacteria.

2008-08-21T12:03:00.002+08:00

Kamikaze bacteria illustrate evolution of co-operation

Suicidal Salmonella sacrifice themselves to allow their clones to get a foothold in the gut.

James Morgan

Bacteria can commit suicide to help their brethren establish more damaging infections — and scientists think that they can explain how this behaviour evolved.

The phenomenon, called self-destructive cooperation, can help bacteria such as Salmonella typhimurium and Clostridium difficile to establish a stronghold in the gut.

By studying mice infected with S. typhimurium, researchers from Switzerland and Canada have now demonstrated how this 'kamikaze' behaviour arose.

The team, led by Martin Ackermann of ETH Zurich in Switzerland, studied how S. typhimurium expresses the Type III secretion systems virulence factors (TTSS-1) that inflame the gut. This eradicates intestinal microflora that would otherwise compete for resources — but also kills most of the S. typhimurium cells in the vicinity. After this assault, the way is clear for remaining S. typhimurium to take advantage and further colonise the gut.

But in the middle of the gut cavity, or lumen, only about 15% of the S. typhimurium population actually expresses TTSS-1. In contrast, in the tissue of the gut wall, almost all bacteria express TTSS-1. As more bacteria invade the tissue, gut inflammation increases and kills off the invaders (especially those within the tissue) - along with the other competing gut flora.

"We thought it was a very strange phenomenon," says team member Wolf-Dietrich Hardt, also at ETH Zurich. "The bacteria in the gut lumen are genetically identical, but some of them are prepared to sacrifice themselves for the greater good. You could compare this act to Kamikaze fighter pilots of the Japanese army."

Kamikaze genes

This self-destructive cooperation relies on the genes controlling this suicidal behaviour not always being expressed. This 'phenotypic noise' means that only a fraction express TTSS-1, allowing the kamikaze genes to persist in the population. If every cell expressed the genes, they would all commit suicide, benefiting none of the population.

The team concluded that acts of self-destructive cooperation can arise, providing that the level of "public good" — in this case, the inflammation of the gut — is high enough. Crucially, cooperative individuals must also benefit from other cooperative acts more often than individuals who are not cooperating, a situation the scientists call 'assortment'.

In the case of gut bacteria, assortment can arise if the minimum number of pathogens required to infect a host is relatively small — as few as 100 cells, in cases such as Escherichia coli.

Change of strategy

The findings, published in Nature¹, chime well with long-established theories on the evolution of altruism and co-operation.

If a gene for sibling altruism is always expressed, it will tend to disappear, because those members of a clutch or litter who possess it may sacrifice themselves for those who do not. However, if the gene is present but not always expressed, it can persist, because some of its carriers may survive to pass it on to subsequent generations.

The research could also aid the design of more potent strategies against pathogenic bacteria. The Salmonella bacterium causes one of the most common bacterial infections in western countries, and is highly dangerous among the elderly and frail. "There is no doubt that a vaccine for Salmonella in humans is needed," says Hardt. "And many strains infecting livestock are becoming resistant to antibiotics.

"But based on our results, I would suggest that the usual strategy of targeting the vaccine against a virulence factor might not be the best strategy, if only a small fraction of the bacteria express it."

References
1. Ackermann, M. et al. Nature 454, 987-990 (2008).

hmm, so there's fat cells that remove fat.. interesting.

2008-08-21T11:52:00.000+08:00

Boosting 'good' fat to burn off the bad

Origins of calorie-sizzling fat cells uncovered in mice.

Heidi Ledford

To most dieters, no fat is good fat. But in work published this week in Nature, an insight into the origin of a special class of calorie-burning fat cells could lead to new ways of boosting metabolism and combating obesity, researchers say.

The sworn enemy of the dieter is the 'white' fat cell. Such cells are little more than sacks of fat, storing energy and providing padding. Less known — and less reviled — is brown fat, made up of heat-producing cells chock full of fat and energy-generating structures called mitochondria. The iron attached to proteins in these mitochondria gives brown fat its characteristic colour.

White fat is by far the more abundant of the two; adults carry many pounds of white fat, but only a few grams of brown fat, concentrated mainly in the front part of the neck and the upper chest. Brown-fat pads between the shoulder blades are thought to help newborns stay warm, but precisely what purpose the cells serve in adults is still unclear.

What is clear is that brown fat burns a tremendous amount of energy: about 50 grams of brown fat could burn up 20% of a person's daily caloric intake, says Ronald Kahn of the Joslin Diabetes Center at Harvard Medical School in Boston, Massachusetts, and one of the researchers involved in the latest study.

"It's a very efficient tissue at wasting energy," agrees Bruce Spiegelman of the Dana-Farber Cancer Institute and Harvard Medical School, another member of the team. "It's basically a fire that's just burning."

That would seem to prompt a simple solution to the growing obesity problem: find a way to generate a extra brown fat and let the body burn away the energy stored in its excess white fat.

Fuel for the fire

That notion surfaced last year when a team of researchers led by Spiegelman found that a protein called PRDM16 could trigger cells that usually produce white fat cells to make brown fat cells instead (see Metabolic switch delivers healthy fat).

Now, two papers in Nature extend that work. Spiegelman and his colleagues have traced the natural origin of brown fat cells¹. They used a fluorescent protein to label a population of cells (called myoblasts) that usually generates muscle, and found that PRDM16 could trigger these cells to form brown, but not white, fat cells. Blocking production of the PRDM16 protein caused these brown fat cells to revert back to muscle. The result runs counter to the previous notion that brown and white fat cells shared similar origins.

Meanwhile, Kahn together with Yu-Hua Tseng and their colleagues have identified another protein, called 'bone morphogenic protein 7' or BMP7, that is crucial to the generation of brown fat cells. When researchers overexpressed the protein, mice developed slightly more brown fat, slightly higher body temperatures and exhibited slightly lower weight gain than untreated mice after just five days².

Kahn feels that the change in weight gain could be more dramatic over a longer time period. His team is testing — thus far only in mice — a commercially available form of BMP7 that is used to encourage bone healing after some surgeries. Because BMP7 can also stimulate bone formation, it must be used with care, Kahn says. His lab is working out conditions that could encourage accumulation of brown fat without forming bone tissue in undesired locations. "Otherwise you could have rock hard abs but not in the way you'd expected," he says.

The work could open new therapeutic avenues, says Dominique Langin, a clinical biochemist at the National Institute of Health and Medical Research (INSERM) in Toulouse, France. But it will be important, he adds, to characterize the process further in humans. In large mammals such as humans, the brown fat present at birth disappears and then reforms in other locations, and the contribution that brown fat makes to overall metabolism is unclear. In mice, brown fat does not undergo the same shift, and it plays a clear role in regulating body temperature.

References
1. Seale, P. et al. Nature 454, 961–967 (2008).
2. Tseng, Y.-H. et al. Nature 454, 1000–1004 (2008).

free labour!!!

2008-08-20T11:39:00.000+08:00

If You Use the Web, You May Have Already Been Enlisted as a Human Scanner

Those anti-bot security forms that slow you down when you're entering information just might serve a larger purpose

By Adam Hadhazy

You're just about ready to buy a pair of tickets on Ticketmaster, but before you can take the next step, an annoying box with wavy letters and numbers shows up on your screen. You dutifully enter in what you see—and what a bot presumably can't—in the name of security.

But what you may not know is that you also have helped archivists decipher distorted characters in old books and newspapers so that they can be posted on the Web.

You might think that computer scientists would have figured out a way to get computers to decipher those characters. But they haven't, so instead they've figured out a way to harness all that effort you're making to protect your security. "When you're reading those squiggly characters, you are doing something that computers cannot," says Luis von Ahn, a computer scientist at Carnegie Mellon University (C.M.U.) in Pittsburgh.

Von Ahn and colleagues reported last week in the journal Science that Web users have transcribed the equivalent of 160 books a day—that's more than 440 million words—in the year since researchers kicked off the program. The initiative is similar to "distributed computing" schemes like SETI@home, which take advantage of unused personal computer processing power to sift through signals received from space for those that might be generated by extraterrestrial intelligence or to figure out how proteins fold. But the difference with this system is that people, not processors, do the calculations.

"We are getting people to help us digitize books at the same time they are authenticating themselves as humans," von Ahn says. "Every time people are typing these [answers] out, they are actually taking old books or newspapers and helping to transcribe them."

Other large digitization projects, such as the Google Books Project and the Internet Archive, rely on optical character recognition (OCR) software. Basically, computers take a digital image of a book or newspaper page, then try to discern the individual letters, von Ahn says. But he and other C.M.U. researchers estimate that these programs misinterpret or fail to read up to one out of every five words on weathered, yellowed paper or on pages with faded or smeared ink. Such electronically illegible words and texts must then be manually transcribed by human workers at a relatively high cost, he says.

Von Ahn's team's method is a twist on the Web site tests known as CAPTCHAs (Completely Automated Public Turing test to tell Computers and Humans Apart), which have been in use since 2000. The new twist on CAPTCHAs is to use a set of letters from old, weathered books and newspapers that computerized transcribing programs cannot recognize. Much of the raw "fuel" comes courtesy of the Internet Archive project, which transmits words that its OCRs cannot recognize or do not appear in the dictionary.

About 40,000 Websites now use the service, called reCAPTCHA, which the project's site offers for free. Facebook was one of its first major patrons.

Von Ahn estimates that at reCAPTCHA's current rate of transcription (about four million words a day missed by OCR systems), the program does a week's worth of transcription from 1,500 professional transcribers in a single day. This data is stored on hard drives at C.M.U. and then sent back to the organization that requested the transcription. (The New York Times, for example, has enlisted reCAPTCHA to digitize the newspaper's archives dating back to 1851.)

Von Ahn acknowledges that the overall cost for reCAPTCHA is still a bit higher than just using OCR for more recently written, more easily scanned texts. He would not say exactly how much, citing nondisclosure agreements with clients using the software.

When the researchers compared how reCAPTCHA and OCR transcribed five Times articles, reCAPTCHA did a significantly better job—99.1 percent accuracy—than OCR of the sort that Google uses for its book project, which came in at 83.5 percent. (Google declined to comment for this story.)

But as is the way with most technology, today's innovation is tomorrow's VHS tape. Eventually computers will be able to decipher reCAPTCHAs, too. "We'll get a few good years out of reCAPTCHAs," says co-author Manuel Blum, a professor of computer science at Carnegie Mellon and key developer of some of the first CAPTCHAs.

OCR will continue to improve as well, Blum says, along with so-called machine learning in general.

Either way, with some 100 million books published prior to the dawn of the digital era, says von Ahn, that "makes for a lot of words."

http://www.sciam.com/article.cfm?id=human-book-scanners-on-the-web&sc=rss

ancient civilizations! XD

2008-08-15T19:31:00.001+08:00

maybe...

http://news.nationalgeographic.com/news/2008/08/080815-sahara-video-vin.html

Ah, a scientific research to the phrase “learning from mistakes”

2008-08-13T21:35:00.002+08:00

Minding Mistakes: How the Brain Monitors Errors and Learns from Goofs

Brain scientists have identified nerve cells that monitor performance, detect errors and govern the ability to learn from misfortunes

By Markus Ullsperger

April 26, 1986: During routine testing, reactor number 4 of the Chernobyl nuclear power plant explodes, triggering the worst catastrophe in the history of the civilian use of nuclear energy.

September 22, 2006: On a trial run, experimental maglev train Transrapid 08 plows into a maintenance vehicle at 125 mph near Lathen, Germany, spewing wreckage over hundreds of yards, killing 23 passengers and severely injuring 10 others.

Human error was behind both accidents. Of course, people make mistakes, both large and small, every day, and monitoring and fixing slipups is a regular part of life. Although people understandably would like to avoid serious errors, most goofs have a good side: they give the brain information about how to improve or fine-tune behavior. In fact, learning from mistakes is likely essential to the survival of our species.

In recent years researchers have identified a region of the brain called the medial frontal cortex that plays a central role in detecting mistakes and responding to them. These frontal neurons become active whenever people or monkeys change their behavior after the kind of negative feedback or diminished reward that results from errors.

Much of our ability to learn from flubs, the latest studies show, stems from the actions of the neurotransmitter dopamine. In fact, genetic variations that affect dopamine signaling may help explain differences between people in the extent to which they learn from past goofs. Meanwhile certain patterns of cerebral activity often foreshadow miscues, opening up the possibility of preventing blunders with portable devices that can detect error-prone brain states.

Error Detector
Hints of the brain's error-detection apparatus emerged serendipitously in the early 1990s. Psychologist Michael Falkenstein of the University of Dortmund in Germany and his colleagues were monitoring subjects' brains using electroencephalography (EEG) during a psychology experiment and noticed that whenever a subject pressed the wrong button, the electrical potential in the frontal lobe suddenly dropped by about 10 microvolts. Psychologist William J. Gehring of the University of Illinois and his colleagues confirmed this effect, which researchers refer to as error-related negativity, or ERN.

An ERN may appear after various types of errors, unfavorable outcomes or conflict situations. Action errors occur when a person's behavior produces an unintended result. Time pressure, for example, often leads to misspellings while typing or incorrect addresses on e-mails. An ERN quickly follows such action errors, peaking within 100 milliseconds after the incorrect muscle activity ends.

A slightly more delayed ERN, one that crests 250 to 300 milliseconds after an outcome, occurs in response to unfavorable feedback or monetary losses. This so-called feedback ERN also may appear in situations in which a person faces a difficult choice—known as decision uncertainty—and remains conflicted even after making a choice. For instance, a feedback ERN may occur after a person has picked a checkout line in a supermarket and then realizes that the line is moving slower than the adjacent queue.

Where in the brain does the ERN originate? Using functional magnetic resonance imaging, among other imaging methods, researchers have repeatedly found that error recognition takes place in the medial frontal cortex, a region on the surface of the brain in the middle of the frontal lobe, including the anterior cingulate. Such studies implicate this brain region as a monitor of negative feedback, action errors and decision uncertainty—and thus as an overall supervisor of human performance.

In a 2005 paper, along with psychologist Stefan Debener of the Institute of Hearing Research in Southampton, England, and our colleagues, I showed that the medial frontal cortex is the probable source of the ERN. In this study, subjects performed a so-called flanker task, in which they specified the direction of a central target arrow in the midst of surrounding decoy arrows while we monitored their brain activity using EEG and fMRI simultaneously. We found that as soon as an ERN occurs, activity in the medial frontal cortex increases and that the bigger the ERN the stronger the fMRI signal, suggesting that this brain region does indeed generate the classic error signal.

Learning from Lapses
In addition to recognizing errors, the brain must have a way of adaptively responding to them. In the 1970s psychologist Patrick Rabbitt of the University of Manchester in England, one of the first to systematically study such reactions, observed that typing misstrikes are made with slightly less keyboard pressure than are correct strokes, as if the typist were attempting to hold back at the last moment.

More generally, people often react to errors by slowing down after a mistake, presumably to more carefully analyze a problem and to switch to a different strategy for tackling a task. Such behavioral changes represent ways in which we learn from our mistakes in hopes of avoiding similar slipups in the future.

The medial frontal cortex seems to govern this process as well. Imaging studies show that neural activity in this region increases, for example, before a person slows down after an action error. Moreover, researchers have found responses from individual neurons in the medial frontal cortex in monkeys that implicate these cells in an animal's behavioral response to negative feedback, akin to that which results from an error.

In 1998 neuroscientists Keisetsu Shima and Jun Tanji of the Tohoku University School of Medicine in Sendai, Japan, trained three monkeys to either push or turn a handle in response to a visual signal. A monkey chose its response based on the reward it expected: it would, say, push the handle if that action had been consistently followed by a reward. But when the researchers successively reduced the reward for pushing—a type of negative feedback or error signal—the animals would within a few trials switch to turning the handle instead. Meanwhile researchers were recording the electrical activity of single neurons in part of the monkeys' cingulate.

Shima and Tanji found that four types of neurons altered their activity after a reduced reward but only if the monkey used that reduction as a cue to push instead of turn, or vice versa. These neurons did not flinch if the monkey did not decide to switch actions or if it did so in response to a tone rather than to a lesser reward. And when the researchers temporarily deactivated neurons in this region, the monkey no longer switched movements after a dip in its incentive. Thus, these neurons relay information about the degree of reward for the purpose of altering behavior and can use negative feedback as a guide to improvement.

In 2004 neurosurgeon Ziv M. Williams and his colleagues at Massachusetts General Hospital reported finding a set of neurons in the human anterior cingulate with similar properties. The researchers recorded from these neurons in five patients who were scheduled for surgical removal of that brain region. While these neurons were tapped, the patients did a task in which they had to choose one of two directions to move a joystick based on a visual cue that also specified a monetary reward: either nine or 15 cents. On the nine-cent trials, participants were supposed to change the direction in which they moved the joystick.

Similar to the responses of monkey neurons, activity among the anterior cingulate neurons rose to the highest levels when the cue indicated a reduced reward along with a change in the direction of movement. In addition, the level of neuronal activity predicted whether a person would act as instructed or make an error. After surgical removal of those cells, the patients made more errors when they were cued to change their behavior in the face of a reduced payment. These neurons, therefore, seem to link information about rewards to behavior. After detecting discrepancies between actual and desired outcomes, the cells determine the corrective action needed to optimize reward.

But unless instructed to do so, animals do not generally alter their behavior after just one mishap. Rather they change strategies only after a pattern of failed attempts. The anterior cingulate also seems to work in this more practical fashion in arbitrating the response to errors. In a 2006 study experimental psychologists Stephen Kennerley and Matthew Rushworth and their colleagues at the University of Oxford taught rhesus monkeys to pull a lever to get food. After 25 trials, the researchers changed the rules, dispensing treats when the monkeys turned the lever instead of pulling it. The monkeys adapted and switched to turning the lever. After a while, the researchers changed the rules once more, and the monkeys again altered their behavior.

Each time the monkeys did not immediately switch actions, but did so only after a few false starts, using the previous four or five trials as a guide. After damage to the anterior cingulate, however, the animals lost this longer-term view and instead used only their most recent success or failure as a guide. Thus, the anterior cingulate seems to control an animal's ability to evaluate a short history of hits and misses as a guide to future decisions.

Chemical Incentive
Such evaluations may depend on dopamine, which conveys success signals in the brain. Neurophysiologist Wolfram Schultz, now at the University of Cambridge, and his colleagues have shown over the past 15 years that dopamine-producing nerve cells alter their activity when a reward is either greater or less than anticipated. When a monkey is rewarded unexpectedly, say, for a correct response, the cells become excited, releasing dopamine, whereas their activity drops when the monkey fails to get a treat after an error. And if dopamine quantity stably altered the connections between nerve cells, its differential release could thereby promote learning from successes and failures.

Indeed, changes in dopamine levels may help to explain how we learn from positive as well as negative reinforcement. Dopamine excites the brain's so-called Go pathway, which promotes a response while also inhibiting the action-suppressing "NoGo" pathway. Thus, bursts of dopamine resulting from positive reinforcement promote learning by both activating the Go channel and blocking NoGo. In contrast, dips in dopamine after negative outcomes should promote avoidance behavior by inactivating the Go pathway while releasing inhibition of NoGo.

In 2004 psychologist Michael J. Frank, then at the University of Colorado at Boulder, and his colleagues reported evidence for dopamine's influence on learning in a study of patients with Parkinson's disease, who produce too little of the neurotransmitter. Frank theorized that Parkinson's patients may have trouble generating the dopamine needed to learn from positive feedback but that their low dopamine levels may facilitate training based on negative feedback.

In the study the researchers displayed pairs of symbols on a computer screen and asked 19 healthy people and 30 Parkinson's patients to choose one symbol from each pair. The word "correct" appeared whenever a subject had chosen an arbitrarily correct symbol, whereas the word "incorrect" flashed after every "wrong" selection. (No symbol was invariably correct or incorrect.) One of them was deemed right 80 percent of the time, and another 20 percent. For other pairs, the probabilities were 70:30 and 60:40. The subjects were expected to learn from this feedback and thereby increase the number of correct choices in later test runs.

As expected, the healthy people learned to prefer the correct symbols and avoid the incorrect ones with about equal proficiency. Parkinson's patients, on the other hand, showed a stronger tendency to reject negative symbols than to select the positive ones—that is, they learned more from their errors than from their hits, showing that the lack of dopamine did bias their learning in the expected way. In addition, the patients' ability to learn from positive feedback outpaced that from negative feedback after they took medication that boosted brain levels of dopamine, underscoring the importance of dopamine in positive reinforcement.

Dopamine-based discrepancies in learning ability also appear within the healthy population. Last December, along with psychology graduate student Tilmann A. Klein and our colleagues, I showed that such variations are partly based on individual differences in a gene for the D2 dopamine receptor. A variant of this gene, called A1, results in up to a 30 percent reduction in the density of those receptors on nerve cell membranes.

We asked 12 males with the A1 variant and 14 males who had the more common form of this gene to perform a symbol-based learning test like the one Frank used. We found that A1 carriers were less able to remember, and avoid, the negative symbols than were the participants who did not have this form of the gene. The A1 carriers also avoided the negative symbols less often than they picked the positive ones. Noncarriers learned about equally well from the good and bad symbols.

Thus, fewer D2 receptors may impair a person's ability to learn from mistakes or negative outcomes. (This molecular quirk is just one of many factors that influence such learning.) Accordingly, our fMRI results show that the medial frontal cortex of A1 carriers generates a weaker response to errors than it does in other people, suggesting that this brain area is one site at which dopamine exerts its effect on learning from negative feedback.

But if fewer D2 receptors leads to impaired avoidance learning, why do drugs that boost dopamine signaling also lead to such impairments in Parkinson's patients? In both scenarios, dopamine signaling may, in fact, be increased through other dopamine receptors; research indicates that A1 carriers produce an unusually large amount of dopamine, perhaps as a way to compensate for their lack of D2 receptors. Whatever the reason, insensitivity to unpleasant consequences may contribute to the slightly higher rates of obesity, compulsive gambling and addiction among A1 carriers than in the general population.

Foreshadowing Faults
Although learning from mistakes may help us avoid future missteps, inexperience or inattention can still lead to errors. Many such goofs turn out to be predictable, however, foreshadowed by telltale changes in brain metabolism, according to research my team published in April in the Proceedings of the National Academy of Sciences USA.

Along with cognitive neuroscientist Tom Eichele of the University of Bergen in Norway and several colleagues, I asked 13 young adults to perform a flanker task while we monitored their brain activity using fMRI. Starting about 30 seconds before our subjects made an error, we found distinct but gradual changes in the activation of two brain networks.

One of the networks, called the default mode region, is usually more active when a person is at rest and quiets down when a person is engaged in a task. But before an error, the posterior part of this network—which includes the retrosplenial cortex, located near the center of the brain at the surface—became more active, indicating that the mind was relaxing. Meanwhile activity declined in areas of the frontal lobe that spring to life whenever a person is working hard at something, suggesting that the person was also becoming less engaged in the task at hand.

Our results show that errors are the product of gradual changes in the brain rather than unpredictable blips in brain activity. Such adjustments could be used to foretell errors, particularly those that occur during monotonous tasks. In the future, people might wear portable devices that monitor these brain states as a first step toward preventing mistakes where they are most likely to occur—and when they matter most.

Editor's Note: This story was originally published with the title "Minding Mistakes"

http://www.sciam.com/article.cfm?id=minding-mistakes

Are Viruses Alive?

2008-08-11T23:25:00.001+08:00

So, are they?

Although viruses challenge our concept of what "living" means, they are vital members of the web of life

By Luis P. Villarreal

In an episode of the classic 1950s television comedy The Honeymooners, Brooklyn bus driver Ralph Kramden loudly explains to his wife, Alice, "You know that I know how easy you get the virus." Half a century ago even regular folks like the Kramdens had some knowledge of viruses—as microscopic bringers of disease. Yet it is almost certain that they did not know exactly what a virus was. They were, and are, not alone.

For about 100 years, the scientifi c community has repeatedly changed its collective mind over what viruses are. First seen as poisons, then as life-forms, then biological chemicals, viruses today are thought of as being in a gray area between living and nonliving: they cannot replicate on their own but can do so in truly living cells and can also affect the behavior of their hosts profoundly. The categorization of viruses as nonliving during much of the modern era of biological science has had an unintended consequence: it has led most researchers to ignore viruses in the study of evolution. Finally, however, scientists are beginning to appreciate viruses as fundamental players in the history of life.

Coming to Terms

It is easy to see why viruses have been diffi cult to pigeonhole. They seem to vary with each lens applied to examine them. The initial interest in viruses stemmed from their association with diseases—the word "virus" has its roots in the Latin term for "poison." In the late 19th century researchers realized that certain diseases, including rabies and foot-and-mouth, were caused by particles that seemed to behave like bacteria but were much smaller. Because they were clearly biological themselves and could be spread from one victim to another with obvious biological effects, viruses were then thought to be the simplest of all living, gene-bearing life-forms.

Their demotion to inert chemicals came after 1935, when Wendell M. Stanley and his colleagues, at what is now the Rockefeller University in New York City, crystallized a virus— tobacco mosaic virus—for the fi rst time. They saw that it consisted of a package of complex biochemicals. But it lacked essential systems necessary for metabolic functions, the biochemical activity of life. Stanley shared the 1946 Nobel Prize— in chemistry, not in physiology or medicine—for this work.

Further research by Stanley and others established that a virus consists of nucleic acids (DNA or RNA) enclosed in a protein coat that may also shelter viral proteins involved in infection. By that description, a virus seems more like a chemistry set than an organism. But when a virus enters a cell (called a host after infection), it is far from inactive. It sheds its coat, bares its genes and induces the cell's own replication machinery to reproduce the intruder's DNA or RNA and manufacture more viral protein based on the instructions in the viral nucleic acid. The newly created viral bits assemble and, voilà, more virus arises, which also may infect other cells.

These behaviors are what led many to think of viruses as existing at the border between chemistry and life. More poetically, virologists Marc H. V. van Regenmortel of the University of Strasbourg in France and Brian W. J. Mahy of the Centers for Disease Control and Prevention have recently said that with their dependence on host cells, viruses lead "a kind of borrowed life." Interestingly, even though biologists long favored the view that viruses were mere boxes of chemicals, they took advantage of viral activity in host cells to determine how nucleic acids code for proteins: indeed, modern molecular biology rests on a foundation of information gained through viruses.

Molecular biologists went on to crystallize most of the essential components of cells and are today accustomed to thinking about cellular constituents—for example, ribosomes, mitochondria, membranes, DNA and proteins—as either chemical machinery or the stuff that the machinery uses or produces. This exposure to multiple complex chemical structures that carry out the processes of life is probably a reason that most molecular biologists do not spend a lot of time puzzling over whether viruses are alive. For them, that exercise might seem equivalent to pondering whether those individual subcellular constituents are alive on their own. This myopic view allows them to see only how viruses co-opt cells or cause disease. The more sweeping question of viral contributions to the history of life on earth, which I will address shortly, remains for the most part unanswered and even unasked.

To Be or Not to Be
The seemingly simple question of whether or not viruses are alive, which my students often ask, has probably defi ed a simple answer all these years because it raises a fundamental issue: What exactly defi nes "life?" A precise scientifi c defi nition of life is an elusive thing, but most observers would agree that life includes certain qualities in addition to an ability to replicate. For example, a living entity is in a state bounded by birth and death. Living organisms also are thought to require a degree of biochemical autonomy, carrying on the metabolic activities that produce the molecules and energy needed to sustain the organism. This level of autonomy is essential to most definitions.

Viruses, however, parasitize essentially all biomolecular aspects of life. That is, they depend on the host cell for the raw materials and energy necessary for nucleic acid synthesis, protein synthesis, processing and transport, and all other biochemical activities that allow the virus to multiply and spread. One might then conclude that even though these processes come under viral direction, viruses are simply nonliving parasites of living metabolic systems. But a spectrum may exist between what is certainly alive and what is not.

A rock is not alive. A metabolically active sack, devoid of genetic material and the potential for propagation, is also not alive. A bacterium, though, is alive. Although it is a single cell, it can generate energy and the molecules needed to sustain itself, and it can reproduce. But what about a seed? A seed might not be considered alive. Yet it has a potential for life, and it may be destroyed. In this regard, viruses resemble seeds more than they do live cells. They have a certain potential, which can be snuffed out, but they do not attain the more autonomous state of life.

Another way to think about life is as an emergent property of a collection of certain nonliving things. Both life and consciousness are examples of emergent complex systems. They each require a critical level of complexity or interaction to achieve their respective states. A neuron by itself, or even in a network of nerves, is not conscious—whole brain complexity is needed. Yet even an intact human brain can be biologically alive but incapable of consciousness, or "brain-dead." Similarly, neither cellular nor viral individual genes or proteins are by themselves alive. The enucleated cell is akin to the state of being braindead, in that it lacks a full critical complexity. A virus, too, fails to reach a critical complexity. So life itself is an emergent, complex state, but it is made from the same fundamental, physical building blocks that constitute a virus. Approached from this perspective, viruses, though not fully alive, may be thought of as being more than inert matter: they verge on life.

In fact, in October, French researchers announced fi ndings that illustrate afresh just how close some viruses might come. Didier Raoult and his colleagues at the University of the Mediterranean in Marseille announced that they had sequenced the genome of the largest known virus, Mimivirus, which was discovered in 1992. The virus, about the same size as a small bacterium, infects amoebae. Sequence analysis of the virus revealed numerous genes previously thought to exist only in cellular organisms. Some of these genes are involved in making the proteins encoded by the viral DNA and may make it easier for Mimivirus to co-opt host cell replication systems. As the research team noted in its report in the journal Science, the enormous complexity of the Mimivirus's genetic complement "challenges the established frontier between viruses and parasitic cellular organisms."

Impact on Evolution
Debates over whether to label viruses as living lead naturally to another question: Is pondering the status of viruses as living or nonliving more than a philosophical exercise, the basis of a lively and heated rhetorical debate but with little real consequence? I think the issue is important, because how scientists regard this question infl uences their thinking about the mechanisms of evolution.

Viruses have their own, ancient evolutionary history, dating to the very origin of cellular life. For example, some viral- repair enzymes—which excise and resynthesize damaged DNA, mend oxygen radical damage, and so on— are unique to certain viruses and have existed almost unchanged probably for billions of years.

Nevertheless, most evolutionary biologists hold that because viruses are not alive, they are unworthy of serious consideration when trying to understand evolution. They also look on viruses as coming from host genes that somehow escaped the host and acquired a protein coat. In this view, viruses are fugitive host genes that have degenerated into parasites. And with viruses thus dismissed from the web of life, important contributions they may have made to the origin of species and the maintenance of life may go unrecognized. (Indeed, only four of the 1,205 pages of the 2002 volume The Encyclopedia of Evolution are devoted to viruses.)

Of course, evolutionary biologists do not deny that viruses have had some role in evolution. But by viewing viruses as inanimate, these investigators place them in the same category of infl uences as, say, climate change. Such external infl uences select among individuals having varied, genetically controlled traits; those individuals most able to survive and thrive when faced with these challenges go on to reproduce most successfully and hence spread their genes to future generations.

But viruses directly exchange genetic information with living organisms—that is, within the web of life itself. A possible surprise to most physicians, and perhaps to most evolutionary biologists as well, is that most known viruses are persistent and innocuous, not pathogenic. They take up residence in cells, where they may remain dormant for long periods or take advantage of the cells' replication apparatus to reproduce at a slow and steady rate. These viruses have developed many clever ways to avoid detection by the host immune system— essentially every step in the immune process can be altered or controlled by various genes found in one virus or another.

Furthermore, a virus genome (the entire complement of DNA or RNA) can permanently colonize its host, adding viral genes to host lineages and ultimately becoming a critical part of the host species' genome. Viruses therefore surely have effects that are faster and more direct than those of external forces that simply select among more slowly generated, internal genetic variations. The huge population of viruses, combined with their rapid rates of replication and mutation, makes them the world's leading source of genetic innovation: they constantly "invent" new genes. And unique genes of viral origin may travel, finding their way into other organisms and contributing to evolutionary change.

Data published by the International Human Genome Sequencing Consortium indicate that somewhere between 113 and 223 genes present in bacteria and in the human genome are absent in well-studied organisms—such as the yeast Saccharomyces cerevisiae, the fruit fly Drosophila melanogaster and the nematode Caenorhabditis elegans—that lie in between those two evolutionary extremes. Some researchers thought that these organisms, which arose after bacteria but before vertebrates, simply lost the genes in question at some point in their evolutionary history. Others suggested that these genes had been transferred directly to the human lineage by invading bacteria.

My colleague Victor DeFilippis of the Vaccine and Gene Therapy Institute of the Oregon Health and Science University and I suggested a third alternative: viruses may originate genes, then colonize two different lineages—for example, bacteria and vertebrates. A gene apparently bestowed on humanity by bacteria may have been given to both by a virus.

In fact, along with other researchers, Philip Bell of Macquarie University in Sydney, Australia, and I contend that the cell nucleus itself is of viral origin. The advent of the nucleus— which differentiates eukaryotes (organisms whose cells contain a true nucleus), including humans, from prokaryotes, such as bacteria—cannot be satisfactorily explained solely by the gradual adaptation of prokaryotic cells until they became eukaryotic. Rather the nucleus may have evolved from a persisting large DNA virus that made a permanent home within prokaryotes. Some support for this idea comes from sequence data showing that the gene for a DNA polymerase (a DNAcopying enzyme) in the virus called T4, which infects bacteria, is closely related to other DNA polymerase genes in both eukaryotes and the viruses that infect them. Patrick Forterre of the University of Paris-Sud has also analyzed enzymes responsible for DNA replication and has concluded that the genes for such enzymes in eukaryotes probably have a viral origin.

From single-celled organisms to human populations, viruses affect all life on earth, often determining what will survive. But viruses themselves also evolve. New viruses, such as the AIDS-causing HIV-1, may be the only biological entities that researchers can actually witness come into being, providing a real-time example of evolution in action.

Viruses matter to life. They are the constantly changing boundary between the worlds of biology and biochemistry. As we continue to unravel the genomes of more and more organisms, the contributions from this dynamic and ancient gene pool should become apparent. Nobel laureate Salvador Luria mused about the viral infl uence on evolution in 1959. "May we not feel," he wrote, "that in the virus, in their merging with the cellular genome and reemerging from them, we observe the units and process which, in the course of evolution, have created the successful genetic patterns that underlie all living cells?" Regardless of whether or not we consider viruses to be alive, it is time to acknowledge and study them in their natural context—within the web of life.

http://www.sciam.com/article.cfm?id=are-viruses-alive-2004&print=true

Must read! All who lack sleep!

2008-08-07T18:33:00.001+08:00

Interesting.. why do we need sleep? I think the second argument is more likely yea?

Sleep on It: How Snoozing Makes You Smarter

During slumber, our brain engages in data analysis, from strengthening memories to solving problems

By Robert Stickgold and Jeffrey M. Ellenbogen

In 1865 Friedrich August Kekulé woke up from a strange dream: he imagined a snake forming a circle and biting its own tail. Like many organic chemists of the time, Kekulé had been working feverishly to describe the true chemical structure of benzene, a problem that continually eluded understanding. But Kekulé's dream of a snake swallowing its tail, so the story goes, helped him to accurately realize that benzene's structure formed a ring. This insight paved the way for a new understanding of organic chemistry and earned Kekulé a title of nobility in Germany.

Although most of us have not been ennobled, there is something undeniably familiar about Kekulé's problem-solving method. Whether deciding to go to a particular college, accept a challenging job offer or propose to a future spouse, "sleeping on it" seems to provide the clarity we need to piece together life's puzzles. But how does slumber present us with answers?

The latest research suggests that while we are peacefully asleep our brain is busily processing the day's information. It combs through recently formed memories, stabilizing, copying and filing them, so that they will be more useful the next day. A night of sleep can make memories resistant to interference from other information and allow us to recall them for use more effectively the next morning. And sleep not only strengthens memories, it also lets the brain sift through newly formed memories, possibly even identifying what is worth keeping and selectively maintaining or enhancing these aspects of a memory. When a picture contains both emotional and unemotional elements, sleep can save the important emotional parts and let the less relevant background drift away. It can analyze collections of memories to discover relations among them or identify the gist of a memory while the unnecessary details fade—perhaps even helping us find the meaning in what we have learned.

Not Merely Resting
If you find this news surprising, you are not alone. Until the mid-1950s, scientists generally assumed that the brain was shut down while we snoozed. Although German psychologist Hermann Ebbinghaus had evidence in 1885 that sleep protects simple memories from decay, for decades researchers attributed the effect to a passive protection against interference. We forget things, they argued, because all the new information coming in pushes out the existing memories. But because there is nothing coming in while we get shut-eye, we simply do not forget as much.

Then, in 1953, the late physiologists Eugene Aserinsky and Nathaniel Kleitman of the University of Chicago discovered the rich variations in brain activity during sleep, and scientists realized they had been missing something important. Aserinsky and Kleitman found that our sleep follows a 90-minute cycle, in and out of rapid-eye-movement (REM) sleep. During REM sleep, our brain waves—the oscillating electromagnetic signals that result from large-scale brain activity—look similar to those produced while we are awake. And in subsequent decades, the late Mircea Steriade of Laval University in Quebec and other neuroscientists discovered that individual collections of neurons were independently firing in between these REM phases, during periods known as slow-wave sleep, when large populations of brain cells fire synchronously in a steady rhythm of one to four beats each second. So it became clear that the sleeping brain was not merely "resting," either in REM sleep or in slow-wave sleep. Sleep was doing something different. Something active.

Sleep to Remember
The turning point in our understanding of sleep and memory came in 1994 in a groundbreaking study. Neurobiologists Avi Karni, Dov Sagi and their colleagues at the Weizmann Institute of Science in Israel showed that when volunteers got a night of sleep, they improved at a task that involved rapidly discriminating between objects they saw—but only when they had had normal amounts of REM sleep. When the subjects were deprived of REM sleep, the improvement disappeared. The fact that performance actually rose overnight negated the idea of passive protection. Something had to be happening within the sleeping brain that altered the memories formed the day before. But Karni and Sagi described REM sleep as a permissive state—one that could allow changes to happen—rather than a necessary one. They proposed that such unconscious improvements could happen across the day or the night. What was important, they argued, was that improvements could only occur during part of the night, during REM.

It was not until one of us (Stickgold) revisited this question in 2000 that it became clear that sleep could, in fact, be necessary for this improvement to occur. Using the same rapid visual discrimination task, we found that only with more than six hours of sleep did people's performance improve over the 24 hours following the learning session. And REM sleep was not the only important component: slow-wave sleep was equally crucial. In other words, sleep—in all its phases—does something to improve memory that being awake does not do.

To understand how that could be so, it helps to review a few memory basics. When we "encode" information in our brain, the newly minted memory is actually just beginning a long journey during which it will be stabilized, enhanced and qualitatively altered, until it bears only faint resemblance to its original form. Over the first few hours, a memory can become more stable, resistant to interference from competing memories. But over longer periods, the brain seems to decide what is important to remember and what is not—and a detailed memory evolves into something more like a story.

In 2006 we demonstrated the powerful ability of sleep to stabilize memories and provided further evidence against the myth that sleep only passively (and, therefore, transiently) protects memories from interference. We reasoned that if sleep merely provides a transient benefit for memory, then memories after sleep should be, once again, susceptible to interference. We first trained people to memorize pairs of words in an A-B pattern (for example, "blanket-window") and then allowed some of the volunteers to sleep. Later they all learned pairs in an A-C pattern ("blanket-sneaker"), which were meant to interfere with their memories of the A-B pairs. As expected, the people who slept could remember more of the A-B pairs than people who had stayed awake could. And when we introduced interfering A-C pairs, it was even more apparent that those who slept had a stronger, more stable memory for the A-B sets. Sleep changed the memory, making it robust and more resistant to interference in the coming day.

But sleep's effects on memory are not limited to stabilization. Over just the past few years, a number of studies have demonstrated the sophistication of the memory processing that happens during slumber. In fact, it appears that as we sleep, the brain might even be dissecting our memories and retaining only the most salient details. In one study we created a series of pictures that included either unpleasant or neutral objects on a neutral background and then had people view the pictures one after another. Twelve hours later we tested their memories for the objects and the backgrounds. The results were quite surprising. Whether the subjects had stayed awake or slept, the accuracy of their memories dropped by 10 percent for everything. Everything, that is, except for the memory of the emotionally evocative objects after night of sleep. Instead of deteriorating, memories for the emotional objects actually seemed to improve by a few percent overnight, showing about a 15 percent improvement relative to the deteriorating backgrounds. After a few more nights, one could imagine that little but the emotional objects would be left. We know this culling happens over time with real-life events, but now it appears that sleep may play a crucial role in this evolution of emotional memories.

Precisely how the brain strengthens and enhances memories remains largely a mystery, although we can make some educated guesses at the basic mechanism. We know that memories are created by altering the strengths of connections among hundreds, thousands or perhaps even millions of neurons, making certain patterns of activity more likely to recur. These patterns of activity, when reactivated, lead to the recall of a memory—whether that memory is where we left the car keys or a pair of words such as "blanket-window." These changes in synaptic strength are thought to arise from a molecular process known as long-term potentiation, which strengthens the connections between pairs of neurons that fire at the same time. Thus, cells that fire together wire together, locking the pattern in place for future recall.

During sleep, the brain reactivates patterns of neural activity that it performed during the day, thus strengthening the memories by long-term potentiation. In 1994 neuroscientists Matthew Wilson and Bruce McNaughton, both then at the University of Arizona, showed this effect for the first time using rats fitted with implants that monitored their brain activity. They taught these rats to circle a track to find food, recording neuronal firing patterns from the rodents' brains all the while. Cells in the hippocampus—a brain structure critical for spatial memory—created a map of the track, with different "place cells" firing as the rats traversed each region of the track [see "The Matrix in Your Head," by James J. Knierim; Scientific American Mind, June/July 2007]. Place cells correspond so closely to exact physical locations that the researchers could monitor the rats' progress around the track simply by watching which place cells were firing at any given time. And here is where it gets even more interesting: when Wilson and McNaughton continued to record from these place cells as the rats slept, they saw the cells continuing to fire in the same order—as if the rats were "practicing" running around the track in their sleep.

As this unconscious rehearsing strengthens memory, something more complex is happening as well—the brain may be selectively rehearsing the more difficult aspects of a task. For instance, Matthew P. Walker's work at Harvard Medical School in 2005 demonstrated that when subjects learned to type complicated sequences such as 4-1-3-2-4 on a keyboard (much like learning a new piano score), sleeping between practice sessions led to faster and more coordinated finger movements. But on more careful examination, he found that people were not simply getting faster overall on this typing task. Instead each subject was getting faster on those particular keystroke sequences at which he or she was worst.

The brain accomplishes this improvement, at least in part, by moving the memory for these sequences overnight. Using functional magnetic resonance imaging, Walker showed that his subjects used different brain regions to control their typing after they had slept. The next day typing elicited more activity in the right primary motor cortex, medial prefrontal lobe, hippocampus and left cerebellum—places that would support faster and more precise key-press movements—and less activity in the parietal cortices, left insula, temporal pole and frontopolar region, areas whose suppression indicates reduced conscious and emotional effort. The entire memory got strengthened, but especially the parts that needed it most, and sleep was doing this work by using different parts of the brain than were used while learning the task.

Solutions in the Dark
These effects of sleep on memory are impressive. Adding to the excitement, recent discoveries show that sleep also facilitates the active analysis of new memories, enabling the brain to solve problems and infer new information. In 2007 one of us (Ellenbogen) showed that the brain learns while we are asleep. The study used a transitive inference task; for example, if Bill is older than Carol and Carol is older than Pierre, the laws of transitivity make it clear that Bill is older than Pierre. Making this inference requires stitching those two fragments of information together. People and animals tend to make these transitive inferences without much conscious thought, and the ability to do so serves as an enormously helpful cognitive skill: we discover new information (Bill is older than Pierre) without ever learning it directly.

The inference seems obvious in Bill and Pierre's case, but in the experiment, we used abstract colored shapes that have no intuitive relation to one another, making the task more challenging. We taught people so-called premise pairs—they learned to choose, for example, the orange oval over the turquoise one, turquoise over green, green over paisley, and so on. The premise pairs imply a hierarchy—if orange is a better choice than turquoise and turquoise is preferred to green, then orange should win over green. But when we tested the subjects on these novel pairings 20 minutes after they learned the premise pairs, they had not yet discovered these hidden relations. They chose green just as often as they chose orange, performing no better than chance.

When we tested subjects 12 hours later on the same day, however, they made the correct choice 70 percent of the time. Simply allowing time to pass enabled the brain to calculate and learn these transitive inferences. And people who slept during the 12 hours performed significantly better, linking the most distant pairs (such as orange versus paisley) with 90 percent accuracy. So it seems the brain needs time after we learn information to process it, connecting the dots, so to speak—and sleep provides the maximum benefit.

In a 2004 study Ullrich Wagner and others in Jan Born's laboratory at the University of Lübeck in Germany elegantly demonstrated just how powerful sleep's processing of memories can be. They taught subjects how to solve a particular type of mathematical problem by using a long and tedious procedure and had them practice it about 100 times. The subjects were then sent away and told to come back 12 hours later, when they were instructed to try it another 200 times.

What the researchers had not told their subjects was that there is a much simpler way to solve these problems. The researchers could tell if and when subjects gained insight into this shortcut, because their speed would suddenly increase. Many of the subjects did, in fact, discover the trick during the second session. But when they got a night's worth of sleep between the two sessions, they were more than two and a half times more likely to figure it out—59 percent of the subjects who slept found the trick, compared with only 23 percent of those who stayed awake between the sessions. Somehow the sleeping brain was solving this problem, without even knowing that there was a problem to solve.

The Need to Sleep
As exciting findings such as these come in more and more rapidly, we are becoming sure of one thing: while we sleep, our brain is anything but inactive. It is now clear that sleep can consolidate memories by enhancing and stabilizing them and by finding patterns within studied material even when we do not know that patterns might be there. It is also obvious that skimping on sleep stymies these crucial cognitive processes: some aspects of memory consolidation only happen with more than six hours of sleep. Miss a night, and the day's memories might be compromised—an unsettling thought in our fast-paced, sleep-deprived society.

But the question remains: Why did we evolve in such a way that certain cognitive functions happen only while we are asleep? Would it not seem to make more sense to have these operations going on in the daytime? Part of the answer might be that the evolutionary pressures for sleep existed long before higher cognition—functions such as immune system regulation and efficient energy usage (for instance, hunt in the day and rest at night) are only two of the many reasons it makes sense to sleep on a planet that alternates between light and darkness. And because we already had evolutionary pressure to sleep, the theory goes, the brain evolved to use that time wisely by processing information from the previous day: acquire by day; process by night.

Or it might have been the other way around. Memory processing seems to be the only function of sleep that actually requires an organism to truly sleep—that is, to become unaware of its surroundings and stop processing incoming sensory signals. This unconscious cognition appears to demand the same brain resources used for processing incoming signals when awake. The brain, therefore, might have to shut off external inputs to get this job done. In contrast, although other functions such as immune system regulation might be more readily performed when an organism is inactive, there does not seem to be any reason why the organism would need to lose awareness. Thus, it may be these other functions that have been added to take advantage of the sleep that had already evolved for memory.

Many other questions remain about our nighttime cognition, however it might have evolved. Exactly how does the brain accomplish this memory processing? What are the chemical or molecular activities that account for these effects? These questions raise a larger issue about memory in general: What makes the brain remember certain pieces of information and forget others? We think the lesson here is that understanding sleep will ultimately help us to better understand memory.

The task might seem daunting, but these puzzles are the kind on which scientists thrive—and they can be answered. First, we will have to design and carry out more and more experiments, slowly teasing out answers. But equally important, we are going to have to sleep on it.

Note: This article was originally published with the title, "Quiet! Sleeping Brain at Work."

HA i knew viruses were alive! not that this makes it any clearer -.-

2008-08-07T15:26:00.000+08:00

'Virophage' suggests viruses are alive

Evidence of illness enhances case for life.

The discovery of a giant virus that falls ill through infection by another virus¹ is fuelling the debate about whether viruses are alive.

“There’s no doubt this is a living organism,” says Jean-Michel Claverie, a virologist at the the CNRS UPR laboratories in Marseilles, part of France’s basic-research agency. “The fact that it can get sick makes it more alive.”

Giant viruses have been captivating virologists since 2003, when a team led by Claverie and Didier Raoult at CNRS UMR, also in Marseilles, reported the discovery of the first monster². The virus had been isolated more than a decade earlier in amoebae from a cooling tower in Bradford, UK, but was initially mistaken for a bacterium because of its size, and was relegated to the freezer.

Closer inspection showed the microbe to be a huge virus with, as later work revealed, a genome harbouring more than 900 protein-coding genes³ — at least three times more than that of the biggest previously known viruses and bigger than that of some bacteria. It was named Acanthamoeba polyphaga mimivirus (for mimicking microbe), and is thought to be part of a much larger family. “It was the cause of great excitement in virology,” says Eugene Koonin at the National Center for Biotechnology Information in Bethesda, Maryland. “It crossed the imaginary boundary between viruses and cellular organisms.”

Now Raoult, Koonin and their colleagues report the isolation of a new strain of giant virus from a cooling tower in Paris, which they have named mamavirus because it seemed slightly larger than mimivirus. Their electron microscopy studies also revealed a second, small virus closely associated with mamavirus that has earned the name Sputnik, after the first man-made satellite.

With just 21 genes, Sputnik is tiny compared with its mama — but insidious. When the giant mamavirus infects an amoeba, it uses its large array of genes to build a ‘viral factory’, a hub where new viral particles are made. Sputnik infects this viral factory and seems to hijack its machinery in order to replicate. The team found that cells co-infected with Sputnik produce fewer and often deformed mamavirus particles, making the virus less infective. This suggests that Sputnik is effectively a viral parasite that sickens its host — seemingly the first such example.

The team suggests that Sputnik is a ‘virophage’, much like the bacteriophage viruses that infect and sicken bacteria. “It infects this factory like a phage infects a bacterium,” Koonin says. “It’s doing what every parasite can — exploiting its host for its own replication.”

Sputnik’s genome reveals further insight into its biology. Although 13 of its genes show little similarity to any other known genes, three are closely related to mimivirus and mamavirus genes, perhaps cannibalized by the tiny virus as it packaged up particles sometime in its history. This suggests that the satellite virus could perform horizontal gene transfer between viruses — paralleling the way that bacteriophages ferry genes between bacteria.

The findings may have global implications, according to some virologists. A metagenomic study of ocean water⁴ has revealed an abundance of genetic sequences closely related to giant viruses, leading to a suspicion that they are a common parasite of plankton. These viruses had been missed for many years, Claverie says, because the filters used to remove bacteria screened out giant viruses as well. Raoult’s team also found genes related to Sputnik’s in an ocean-sampling data set, so this could be the first of a new, common family of viruses. “It suggests there are other representatives of this viral family out there in the environment,” Koonin says.

By regulating the growth and death of plankton, giant viruses — and satellite viruses such as Sputnik — could be having major effects on ocean nutrient cycles and climate. “These viruses could be major players in global systems,” says Curtis Suttle, an expert in marine viruses at the University of British Columbia in Vancouver.

“I think ultimately we will find a huge number of novel viruses in the ocean and other places,” Suttle says — 70% of viral genes identified in ocean surveys have never been seen before. “It emphasizes how little is known about these organisms — and I use that term deliberately.”

References
1. La Scola, B. et al. Nature doi:10.1038/nature07218 (2008).
2. La Scola, B. et al. Science 299, 2033 (2003).
3. Raoult, D. et al. Science 306, 1344–1350 (2004).
4. Monier, A. , Claverie, J.-M. & Ogata, H. Genome Biol. 9, R106 (2008).

http://www.nature.com/news/2008/080806/full/454677a.html?s=news_rss

Synaesthesia: a world of wonders

2008-08-06T22:14:00.001+08:00

People with synaesthesia can't help but get two sensory perceptions for the price of one. Some perceive colours when they hear words or musical notes, or read numbers; rarer individuals can even get tastes from shapes.

Neuroscientists have now reported¹ another variant, in which flashes and moving images trigger the perception of sounds. The finding could help to identify the precise neural causes of the phenomenon, reportedly experienced by at least one in every hundred people, and suggests that at least some types of synaesthesia are closely related to ordinary perception.

"This [study] will make a big impact," says synaesthesia expert Edward Hubbard of France's biomedical research organization INSERM. "It will affect not just the synaesthesia community, but also researchers interested in how the brain handles information from multiple senses."

Neuroscientist Melissa Saenz of the California Institute of Technology (Caltech) in Pasadena stumbled across the variant last year while giving a group of undergraduate students a tour of her perception research lab. In front of a silent display (see picture) designed to evoke activity in the motion processing centre of the visual cortex, one of the students asked: "Does anybody else hear something?"

The student, Johannes Pulst-Korenberg, reported hearing a distinct whooshing sound when he watched the display. "Everybody was looking at me, like, 'Are you crazy?'" he remembers.

Saenz could find no description of this variant of synaesthesia in the scientific literature. But to her surprise, after screening several hundred people in the Caltech community, she found three more who reported a similar experience.

"They're generally soft sounds, but they can't be ignored, even when they're distracting," says Saenz. "One of the synaesthetes told me that the moving images on computer screen savers are terribly annoying to her. She can't do anything about it but look away."

Pulst-Korenberg, who is pursuing a doctorate in neuroscience and economics at Caltech, says that he has experienced the same effect watching a butterfly fly. "For some reason, the jerky motion generates little clicks," he says.

The sound of change

Saenz and her lab director, Christof Koch, confirmed the four cases with a test that gave true 'hearing–motion' synaesthetes a distinct advantage. They asked 14 people, including the 4 with synaesthesia, to watch two quick sequences of Morse-code type flashes, and then determine whether the sequences were the same or subtly different. As they were able to 'hear' the sequences too, the synaesthetes, could distinguish them much more accurately than 10 people without synaesthesia. When the sequences instead comprised auditory beeps, the synaesthetes again performed well, but having lost their advantage they scored no better than the non-synaesthete controls.

Some neuroscientists attribute synaesthesia to remnant cross-links between closely-spaced cortical areas — links that develop in the early stages of life but are usually pruned away during childhood. In letter-to-colour synaesthesia, for example, the relevant cortical area for recognizing letters turns out to be immediately adjacent to the one for perceiving colour. Another leading theory explains the condition as an excess of feedback signals from multi-sensory regions, where perceptions are usually integrated, down to single-sensory areas.

Brain-imaging studies have provided evidence for both theories, says Hubbard. "But I don't think the type of synaesthesia that Melissa has discovered really fits neatly into either one."

Instead, it might be an enhanced form of the fast, cross-cortical correspondences the brain makes all the time, he suggests. "For example, we find it easier to understand what someone is saying if we can also see their mouth move. So the brain is constantly integrating audition and vision." Delineating how the brain performs this ordinary integration, says Hubbard, "is probably a part of what will be required if we're to explain the type of synaesthesia that Melissa has discovered here."

If hearing–motion synaesthesia is closely related to ordinary cross-sensory correspondence, it might also explain why it has taken so long to discover. "In real life," says Saenz, "things that move or flash usually do make a sound, so that association is more logical than, say, numbers-to-colours."

References
- Saenz, M. and Koch, C. Current Biol. 18, R650-R651 (2008) | Article |

http://www.nature.com/news/2008/080805/full/news.2008.1014.html?s=news_rss

OOO monster…

2008-08-05T02:59:00.001+08:00

Nothing like a bizarre-looking sea "monster" to draw crowds to a tony resort town. The blogosphere has been abuzz since Gawker.com
early this week featured a story and photo of a bulky hairless corpse with sharp teeth and a snout that reportedly washed up in Montauk on the eastern tip of Long Island, N.Y. Another Big Foot or Loch Ness Monster, perhaps?

The report of the cryptid was picked up by Fox News, CNN and other TV nets, magazines and newspapers as far away as London hungry for a hot story to spice up the summer news doldrums.

"We were looking for a place to sit when we saw some people looking at something," Jenna Hewitt, 26, told Newsday. "We were kind of amazed, shocked and amazed." Hewitt was among a bunch of locals who insist they saw the odd-looking corpse. Most of those weighing in on the creature's identity subscribed to the theory that it was a dog. (A pit bull was the prevailing favorite.)

Others, some who only saw the snapshot, speculated it may have been a raccoon or, perhaps, a sea turtle that lost its shell.

But we may never know for sure. It seems, you see, that the body has been moved. And nobody (at least nobody talking) knows by whom—or where it was taken.

"They say an old guy came and carted it away," Hewitt said. "He said, "I'm going to mount it on my wall."

Charming.

http://www.sciam.com/blog/60-second-science/post.cfm?id=mystery-of-the-montauk-monster-2008-08-01&sc=rss

Other catalyst for hydrogen…

2008-07-25T23:43:00.001+08:00

Hmm interesting… once again, man gets technology from nature.

Iron and carbon monoxide are the crucial ingredients that nature uses to process hydrogen, according to researchers. Resolving the structure of the last of the three known hydrogenase enzymes has excited chemists, who are keen to follow nature's clear advice and develop their own hydrogen catalysts for energy applications.

The dream of replacing oil with hydrogen is in danger of stalling without a cheap and clean way to make it and release its stored chemical energy. The best synthetic catalysts use platinum to do those jobs — which involve splitting hydrogen molecules into ions, or recombining the ions to make molecules again. But this rare, expensive metal is hardly the answer to sustainable living.

Nature manages the process with a cheap metal – iron. There are three iron-containing hydrogenase enzymes to choose from. All three are found in unrelated organisms that have evolved their enzymes separately. Two have been found in bacteria in soil and oil wells; the third is used to provide energy for certain microbes living around hydrothermal vents, by combining hydrogen and carbon dioxide to make methane.

The first two contain a pair of metal atoms at their active site — either iron–iron, or iron–nickel — buried deep inside the enzymes' structures. But researchers in Germany, led by Seigo Shima at the Max Planck Institute for Terrestrial Microbiology in Marburg, and Ulrich Ermler at the Max-Planck Institute for Biophysics in Frankfurt, have now achieved what others had failed to do — figure out the detailed structure of the third hydrogenase, known as [Fe] hydrogenase.

Mix and match

The active site in [Fe] hydrogenase is light sensitive, so previous crystal structures had shown just the bare skeleton of the enzyme, leaving biochemists in the dark about exactly how it worked.

To get a high-quality crystal of the enzyme, Shima and Ermler's groups first took the active part of the hydrogenase from Methanothermobacter marburgensis, and separately extracted the enzyme without its active component from another organism, Methanocaldococcus jannaschii.

The active site of [Fe] hydrogenase hooks up with carbon monoxide, water and an unknown ligand (Unk).SCIENCE

They then reconstituted the whole active enzyme by carefully mixing the two together in a dark, air-free environment. This gave enough material to grow a crystal of the intact enzyme, the structure of which is published in Science¹.

[Fe] hydrogenase's active site has just one iron atom, linked to two CO groups and two other organic groups. The active site also contains an as-yet uncharacterized ligand, and another vacant site which, in the team's structure, is occupied by water (see graphic, right).

The structure shows that the enzyme splits hydrogen in a different way to the other two hydrogenases. Normally, a molecule of hydrogen is split by a metal at the centre of the enzyme, leaving positive and negative hydrogen ions. The positive ion is whipped away, whereas the negatively charged hydride has its two electrons removed to make another positively charged ion.

Once, twice, three times an enzyme

But [Fe] hydrogenase has an active site that sits near the edge of the enzyme. When the hydrogen molecule is broken up, the negative hydride is quickly grabbed by an organic molecule that also sits near the enzyme's surface. This mopped-up hydride is eventually used by the host organism to make methane.

"It works quite differently, it's very surprising," says Tom Rauchfuss, a catalysis expert at the University of Illinois at Urbana-Champaign. But the three hydrogenases have an obvious similarity — all three active sites contain an iron atom stuck to a CO group. "This is almost a religious moment," says Rauchfuss. "This is nature saying three times: I like iron and CO

Both metal and ligand seem to be crucial, says Juan Fontecilla-Camps at Joseph Fourier University in Grenoble, France. "These active sites are the only ones known that have CO bound to metal," he says. "The iron–CO unit is unique to hydrogen metabolism."

John Peters, an expert on the iron–iron hydrogenase enzyme at Montana State University in Bozeman, reckons that organic chemists will now look for ways to make the molecule that mops up the freshly minted hydride ion, whereas inorganic chemists will try to produce a range of structures based on iron and CO. Between them, they might just take nature's hint and create a catalyst to keep the hydrogen dream alive.

References
- Shima, S. et al. Science 321, 572–575 (2008).

http://www.nature.com/news/2008/080724/full/news.2008.972.html?s=news_rss

School project? Crazy effort more like.

2008-07-23T16:05:00.001+08:00

Ok, I usually won't put these kinds of rants on my blog, but I think this one's worth it ^^

So, yesterday, normal day, went to class, rushed homework. I was about to leave, when I saw the sad, sad, condition of our house mascot. Really, a dragon? It looks like an elderly, toothless crocodile. So, I decided to stay. Anyway, 963 is always so darn crowded that by 6pm, the bus wouldn't even stop for you. So, I listened in on what was needed to be done, which was obviously, a lot. The whiskers of the dragon was soft, the paper Mache thingy they did to cover the boxes was still wet, there was no eye of the dragon (pun not intended for the fans of ninja gaiden), head was unbalanced... So who was left to deal with this hunk of junk? Me, Nat, Jingmin and Aaron. 4 people to handle a head. We decided that we would need some extra materials, so Nat volunteered to go out in his dad's car and buy the lot. Aaron got bored and went off to handle his stuff first, saying that he'd come back later when Nat arrives. So there we were, stuck between staring at a soggy dragon head and watching a more entertaining show: Fleming doing THEIR mascot.

Their mascot is griffin. Which griffin? The one with the eagle stuck to the torso of a lion, or simply a huge eagle? Whatever the case, not much difference if you're just gonna make the head yea? It still looks like a large bird. Whatever the case was, they asked Michael to buy a wok, to act as a helmet and a support. Idea was pretty good. They also got him to buy masking tape and… something else. So essentially, the whole Fleming team sat there waiting for a clueless boy to come back with some of the weirdest combinations of materials possible. Daniel told me Michael was really blur. "I told him to buy a wok. He asked me metal or wooden" -.- I've never heard of a wooden wok. As long as Michael doesn't come back with a ladle, Fleming ain't killing him, and my source of entertainment would be gone. So we waited for him to be back. (and Nat wasn't back yet.) 10min ETA, Yunhui said that Michael couldn't find a wok, so he bought a cooker instead. *grins* someone's gonna die! During that 10min, we laughed over a huge running joke about buying hookers off the cash converters (someone misheard cooker). When Michael returned, we had the biggest laugh of our lives. Our good friend here bought a steamboat set, heating element included. It was HILARIOUS! Oh well, with Johnny on their team, they quickly got the heating element off, and got to work. In the mean time, I had gotten bored with their team and I went back to our sorry headset. NAT'S NOT BACK!!!

He finally returned with all the things we needed, together with his dad's car tool kit. Aaron came back, and we got to work stripping the hangers as backing for the whiskers. In the mean time, Jingmin went on to paint the boney plates of the dragon. Nat was having fun trying to make the dragon's nostrils. Aaron helped some, then went off for study time. By the time he was back, we managed to strip all the hangers, attach 2 to the whiskers, and we were already trying to staple it to the front of the dragon. Johnny was really nice and gave us some thin wires to fasten the whiskers to the head. ½ hour later, my dad arrived to pick me up. We weren't done yet, so I asked for his help. With his brilliant idea, we realized we could make life easier by making holes in the top of the head to slide the horns through. Now to make the horns. After awhile, curfew, so Aaron had to go back. Strength, back to me, Jingmin and Nat. Soon, DUDE came by. (we decided to call the security guard that after arguments on what name to call him) He told us that we couldn't stay here any longer as it was already 10 30. For some reason, we didn't even have time to pack. What to do? That guy was doing his job. Nat went crazy. He suddenly thought of a crazy idea to bring everything out of the school, sit next to the AYE where the bus stop is, and do the rest there. So, we happily moved everything there, and plunked our butts down on the pavement and started working. DUDE couldn't do anything since we were already out of the school. My dad went home first to put my bag back. After awhile, we realized that we were down to less than 2m of masking tape. PANIC! We were stuck outside school, with almost no masking tape left, and the bus drivers were staring at us for being such a sight. More Nat crazy ideas. He came up with this completely nutcase idea to get Aaron to throw the masking tape out of the school campus onto the pavement. So there we were, me, sitting there and cutting cardboard and endangering my jewels, Jingmin either drawing the designs, or painting, and Nat running up and down trying to organize a masking tape throwing contest. Of course it failed. Landed on the curb inside the school. More crazy ideas, CMF's turn. She stays on the 10 floor I think? So that means more distance and thus further? Possibly. So, more masking tape throwing contest. Nat helped us while CMF went around trying to find more masking tape. By the way, to all anti nobellers, the horns on the dragon head are also hanger wire reinforced. Do not try to smash it or you might end up in hospital. So, anyway, by the time she was done, we had already made the frills for the dragon. Out of cardboard. Frail frills… regardless, we were happily getting ready to get our masking tape when nice teacher comes (I'm starting to forget names already ><). She realized that we were stuck outside school with limited masking tape and a Jingmin who was freaking out from all the ghost stories that Nat was telling (if you do read this, remember the wind XD). She moved us to a brighter place, outside the hostel office. Then there we were so happy that we could finally do our work in a more workable place and stuff. CMF wasn't happy that she couldn't throw her masking tape, so she lowered it down to us anyway with twine. XD thanks for the twine Mel! So there we sat, working on our head furiously against the deadline the nice teacher set for us. Me and Nat called our dad in again (Yay to dads!) and they helped us attached the frills on. So now we have a frilled dragon, with whiskers that actually looks like a dragon. If you see it on black and white TV. So we finished up the dragon, decided to leave the headgear attachment and painting to later, and packed up. Jingmin got home safely, and both me and Nat went home in our respective cars. Clock, 2:04am.

There, 2am, no dinner, very sleepy, excess of masking tape, dragon… mostly done. And 2 very pissed off security guards XD. Job done!

I would like to take this opportunity to thank all the people who helped us with the dragon: Nat, Jingmin, for being there at the scene all the way and helping; Aaron, for helping with ½ the work and his masking tape XD; CMF for being extremely helpful at 12am in the morning, providing masking tape; Mel for her twine; both security guards for being extremely patient to 3 overenthusiastic students; nice teacher for being nice; last but far from the least, both Dads for being super helpful and supportive! I mean, whose dad will come down at 1am in the morning to school to help their kids on a head? Twice?

Migraines

2008-07-23T14:59:00.001+08:00

For those with migraines, here you go:

Why Migraines Strike

Biologists finally are unraveling the medical mysteries of migraine, from aura to pain

By David W. Dodick and J. Jay Gargus

For the more than 300 million people who suffer migraines, the excruciating, pulsating pain that characterizes these debilitating headaches needs no description. For those who do not, the closest analogous experience might be severe altitude sickness: nausea, acute sensitivity to light, and searing, bed-confining headache. "That no one dies of migraine seems, to someone deep into an attack, an ambiguous blessing," wrote Joan Didion in the 1979 essay "In Bed" from her collection The White Album.

Historical records suggest the condition has been with us for at least 7,000 years, yet it continues to be one of the most misunderstood, poorly recognized and inadequately treated medical disorders. Indeed, many people seek no medical care for their agonies, most likely believing that doctors can do little to help or will be downright skeptical and hostile toward them. Didion wrote "In Bed" almost three decades ago, but some physicians remain as dismissive today as they were then: "For I had no brain tumor, no eyestrain, no high blood pressure, nothing wrong with me at all: I simply had migraine headaches, and migraine headaches were, as everyone who did not have them knew, imaginary."

Migraine is finally starting to get the attention it deserves. Some of that attention is the result of epidemiological studies revealing just how common these headaches are and how incapacitating: a World Health Organization report described migraine as one of the four most disabling chronic medical disorders. Additional concern results from recognition that such headaches and their aftermaths cost the U.S. economy $17 billion a year in lost work, disability payments and health care expenses. But most of the growing interest comes from new discoveries in genetics, brain imaging and molecular biology. Though of very different natures, those findings seem to converge and reinforce one another, making researchers hopeful that they can get to the bottom of migraine's causes and develop improved therapies to prevent them or halt them in their tracks.

The Ascent of Vapors
Any plausible explanation of migraine needs to account for a wide and varied set of symptoms. The frequency, duration, experience and catalysts of episodes differ greatly. Victims have, on average, one or two daylong attacks every month. But 10 percent get them weekly, 20 percent experience them for two to three days, and up to 14 percent have them more than 15 days a month. Often the pain strikes just one side of the head, but not always. Migraines in people prone to them can be set in motion by such a variety of events that they seem inescapable; alcohol, dehydration, physical exertion, menstruation, emotional stress, weather changes, seasonal changes, allergies, sleep deprivation, hunger, altitude and fluorescent lights are all cited as triggers. Migraines occur in all ages and both genders, yet women between the ages of 15 and 55 are disproportionately hit—two thirds of cases occur in this population.

Physicians over the years have proposed many reasons for why these headaches arise. Galen in ancient Greece attributed them to the ascent of vapors, or humors, from the liver to the head. Galen's description of hemicrania—a painful disorder affecting approximately one half of the head—is indeed what we refer to as migraine today: the old word "hemicrania" eventually became "megrim" and ultimately "migraine."

Blood flow replaced humors as the culprit in the 17th century, and this vascular hypothesis held sway, with few exceptions, until the 1980s. The accepted idea, based on the observations and inferences of several physicians, including Harold G. Wolff of New York–Presbyterian Hospital, was that migraine pain stems from the dilation and stretching of brain blood vessels, leading to the activation of pain-signaling neurons. Wolff thought the headache was preceded by a drop in blood flow brought about by the constriction of these same blood vessels.

Fresh observations from brain scans have altered understanding of the vascular changes. It turns out that in many the pain is preceded not by a decrease in blood flow but by an increase—an increase of about 300 percent. During the headache itself, though, blood flow is not increased; in fact, circulation appears normal or even reduced. Not only has the specific understanding of blood flow changed, but so has the prevailing view of the root of migraine. Migraine is now thought to arise from a disorder of the nervous system—and likely from the most ancient part of that system, the brain stem.

Aura's Origin
This newer insight has come mainly from studying two aspects of migraine: the aura, which precedes the pain in 30 percent of sufferers, and the headache itself. The term "aura" has been used for nearly 2,000 years to describe the sensory hallucinations immediately preceding some epileptic seizures; for 100 years or so, it has also been used to describe the onset of many migraines. (Epilepsy may occur in people with migraine, and vice versa; the reasons are under investigation.) The most common form of aura is a visual illusion of brilliant stars, sparks, flashes of light, lightning bolts or geometric patterns, which are often followed by dark spots in the same shape as the original bright image. For some people, the aura can include a feeling of tingling or weakness, or both, on one side of the body as well as speech impairment. Usually the aura precedes the headache, but it may start after the pain begins and persist through it.

Aura appears to stem from cortical spreading depression—a kind of "brainstorm" anticipated as the cause of migraine in the writings of 19th-century physician Edward Lieving. Although biologist Aristides Leão first reported the phenomenon in animals in 1944, it was experimentally linked to migraine only recently. In more technical terms, cortical spreading depression is a wave of intense nerve cell activity that spreads through an unusually large swath of the cortex (the furrowed, outer layer of the brain), especially the areas that control vision. This hyperexcitable phase is followed by a wave of widespread, and relatively prolonged, neuronal inhibition. During this inhibitory phase, the neurons are in a state of "suspended animation," during which they cannot be excited.

Neuronal activity is controlled by a carefully synchronized flow of sodium, potassium and calcium ions across the nerve cell membrane through channels and pumps. The pumps keep resting cells high in potassium and low in sodium and calcium. A neuron "fires," releasing neurotransmitters, when the inward flow of sodium and calcium through opened channels depolarizes the membrane—that is, when the inside of the cell becomes positively charged relative to the outside. Normally, cells then briefly hyperpolarize: they become strongly negative on the inside relative to the outside by allowing potassium ions to rush out. Hyperpolarization closes the sodium and calcium channels and returns the neurons to their resting state soon after firing. But neurons can remain excessively hyperpolarized, or inhibited, for a long time following intense stimulations.

The phases of hyperexcitability followed by inhibition that characterize cortical spreading depression can explain the changes in blood flow that have been documented to occur before migraine pain sets in. When neurons are active and firing, they require a great deal of energy and, thus, blood—just what investigators see during brain scans of patients experiencing aura. But afterward, during inhibition, the quiet neurons need less blood.

Various other observations support the idea that cortical spreading depression underlies aura. When recorded by advanced imaging technology, the timing of the depolarizing wave dovetails neatly with descriptions of aura. The electrical wave travels across the cortex at a rate of two to three millimeters a minute, and the visual illusions that accompany aura are exactly those that would arise from an activation spreading across the cortical fields at just that rate. The suite of sensations that aura can entail—visual, sensory, motor—suggest that corresponding areas of the cortex are affected in sequence as the "storm" crosses them. The dark spots that patients experience after the bright hallucinations are consistent with neuronal inhibition in the regions of the visual cortex that have just experienced the hyperexcitability.

Genetic studies have offered a clue to why cortical spreading depression occurs in some migraine sufferers. Nearly all migraine is thought to be a common complex polygenetic disorder—in the same camp as diabetes, cancer, autism, hypertension and many other disorders. Such diseases run in families. Identical twins are much more likely to share migraine than fraternal twins are, indicating a strong genetic component. But the disease is clearly not caused by a single genetic mutation; rather a person apparently becomes susceptible by inheriting mutations in a number of genes, each probably making a small contribution. Nongenetic components operate as well, because even identical twins are "discordant" for the disorder: sometimes one twin will suffer from migraine, and the other will not.

Investigators do not know which genes increase susceptibility to migraine and its aura in the general population, but studies of people affected by a rare form of the disorder, called familial hemiplegic migraine, indicate that flaws in neuronal ion channels and pumps cause the aura and pain in these patients. Notably, three genes have been shown to carry mutations that individually are potent enough to cause the disease—and all three encode neuronal ion channels and pumps. What is more, the genes are altered by mutations that increase the excitability of nerve cells, presumably by altering the properties of the encoded ion channels and pumps. These findings strongly support the idea that migraine could be a channelopathy, a newly recognized type of disease that arises from disturbances in ion transport systems—a known cause of ailments such as cardiac arrhythmia and seizures.

It is not clear whether malfunctioning ion pumps and channels are the only means by which aura can be produced. Nor is it clear that the common forms of migraine involve perturbations in the three genes implicated in familial hemiplegic migraine. But the genetic insights remain very exciting because they suggest a relation between cortical spreading depression and ion channel problems, one that could prove crucial to designing new medications.

From Aura to Ache
At the same time that researchers have been making headway in understanding the relation between aura and cortical spreading depression, they have been probing the source of migraine pain—the headache that is felt in those who experience aura as well as those who do not. The immediate source of the pain itself is obvious. Although most regions of the brain do not register or transmit pain signals, a network of nerves called the trigeminal nerve system does. These neurons carry pain signals from the membranes that surround the brain, called the meninges, as well as from the blood vessels that infuse the membranes. Pain is relayed through the trigeminal network to an area called the trigeminal nucleus in the brain stem and, from there, can be conveyed up through the thalamus to the sensory cortex, which is involved in our awareness of pain and other senses. What first activates the trigeminal nerves in migraine, however, is under debate. There are essentially two schools of thought.

Some researchers contend that cortical spreading depression directly stimulates the trigeminal nerves. As the wave of hyperexcitability travels across the cortex, it brings about the release of neurotransmitters, such as glutamate and nitric oxide, as well as of ions. These chemicals serve as messengers that induce the trigeminal nerves to transmit pain signals. Researchers have observed in animals that cortical spreading depression does indeed activate the trigeminal nerves in this way.

That pathway to pain could even explain what happens in patients who do not experience aura. According to this view, cortical spreading depression might occur in areas of the cortex whose activation produces no outward symptoms before the onset of pain. Or spreading depression might occur in subcortical regions in certain people and stimulate the trigeminal nerves. In this case, although patients may not experience aura, the basic physiology would be the same as in those who do. Good evidence supports this hypothesis. Spreading depression can be evoked in laboratory animals in subcortical regions.

Moreover, the changes in cerebral blood flow that reflect the phases of cortical excitation and subsequent inhibition in migraine sufferers with aura have also been seen in people who experience migraine without aura; those patients, too, show a large increase in blood flow followed by normal or reduced flow. This finding raises the possibility that cortical spreading depression is fundamental to migraine but that only in some instances does it give rise to visual symptoms recognized as aura. Instead the process might generate less obvious symptoms, such as fatigue or difficulty concentrating. The finding may also explain why many people who experience aura will at times undergo attacks without it.

Other investigators place the root of migraine pain not in cortical or subcortical spreading depression but in the brain stem—Grand Central Station for information passing to and from the body and the brain. It is also home to the control center for alertness, perception of light and noise, cerebral blood flow, respiration, sleep-wake cycles, cardiovascular function and, as described earlier, pain sensitivity.

Positron-emission tomography has revealed that three clusters of cells, or nuclei, in thebrain stem—the locus coeruleus, raphe nucleus and periaqueductal gray—are active during and after migraine. According to this hypothesis, abnormal activity in those nuclei could induce pain in two ways. The nuclei normally inhibit trigeminal neurons within the trigeminal nucleus, continuously saying, in effect, "don't fire." The nuclei's misbehavior could impair this ability and thus allow the trigeminal neurons to fire even when the meninges send no pain signals. In that situation, the trigeminal nucleus would relay pain messages to the sensory cortex in the absence of incoming pain signals from the meninges or blood vessels. The three nuclei might also trigger spreading depression.

Researchers have noted that if one were to alter a part of the brain stem so as to bring about other symptoms of migraine as well, including aura, the place to do it would be these three nuclei. One of their most important functions is to control the flow of sensory information—such as light, noise, smell and pain—that reaches the sensory cortex. Occasional dysfunction in these clusters of cells could therefore explain why migraine sufferers may experience sensitivity to light, sound and odors.

In addition, the activity of these cells is modulated by the behavioral and emotional state of the individual—factors that can trigger migraines. These brain stem areas receive input from only two areas of the cortex, the limbic and paralimbic cortices, regions that regulate arousal, attention and mood. Through its connection with the brain stem, the limbic cortex affects the functioning of the rest of the cortex—a fact that might explain how emotional and psychological stress could catalyze migraines, why mood fluctuates during migraine, and why there is an association between migraine and depression and anxiety disorders, both of which occur more commonly in migraine sufferers than in others.

Finally, the spontaneous, pacemakerlike activity of the raphe nucleus neurons—crucial to regulating pain pathways, circadian rhythms and sleep-wake cycles—depends on the perfect working of ion channels in neurons of that region and on the neurons' release of the neurotransmitters norepinephrine and serotonin into other brain areas. Such neurotransmission may be an ancient mechanism that is perturbed in migraine: experiments in the roundworm Caenorhabditis elegans have revealed that two genes very like those mutated in familial hemiplegic migraine are critical regulators of serotonin release. This finding opens the possibility that mutations in ion channels may lead to aberrant function in these brain stem areas and perhaps, as a result, to hyperexcitability in the cortical areas they influence.

The question then becomes, Does pain typically arise from the intrinsic hyperexcitability of cortical neurons (which leads to cortical spreading depression, activation of meningeal trigeminal pain fibers and the pain of a migraine)? Or does some glitch in brain stem activity incite the pain (by directly rendering the trigeminal neurons spontaneously active or by facilitating cortical spreading depression, or both)? The latter scenario is more convincing to some researchers because the pivotal control exerted by the brain stem over so many aspects of our experience could explain the varied symptoms of migraine.

What the Future May Hold
At the moment, only a few drugs can prevent migraine. All of them were developed for other diseases, including hypertension, depression and epilepsy. Because they are not specific to migraine, it will come as no surprise that they work in only 50 percent of patients—and, in them, only 50 percent of the time—and induce a range of side effects, some potentially serious.

Recent research on the mechanism of these antihypertensive, antiepileptic and antidepressant drugs has demonstrated that one of their effects is to inhibit cortical spreading depression. The drugs' ability to prevent migraine with and without aura therefore supports the school of thought that cortical spreading depression contributes to both kinds of attacks. Using this observation as a starting point, investigators have come up with novel drugs that specifically inhibit cortical spreading depression. Those drugs are now being tested in migraine sufferers with and without aura. They work by preventing gap junctions, a form of ion channel, from opening, thereby halting the flow of calcium between brain cells.

The medicines prescribed for use during an attack have been as problematic as the ones used preventively. Triptans—as the class of drug is called—constrict blood vessels throughout the body, including coronary arteries, seriously limiting their use. These treatments were developed based on the mistaken idea that blood vessel dilation caused the pain and thus constriction was necessary to alleviate it.

It now appears that triptans ease migraine by interrupting the release of messenger molecules—specifically calcitonin gene–related peptide—from trigeminal nerves that feed signals into the trigeminal nucleus. The interruption blocks those trigeminal nerves from communicating with the brain stem's pain-transmitting network of neurons. It is also possible that triptans prevent such communication by operating in the thalamus and the periaqueductal gray.

The new understanding of triptan activity has opened up possibilities for drug development, including a focus on calcitonin gene–related peptide. Several medicines that block the action of that pain-producing neurotransmitter are in clinical trials, and they appear not to constrict arteries. In addition, researchers are devising therapies that target other trigeminal neurotransmitters, such as glutamate and nitric oxide, in a further effort to interrupt the communication between trigeminal nerves innervating the meninges and the trigeminal nucleus in the brain stem. These compounds will be the first specifically designed to combat migraine during an attack by targeting neurons without constricting blood vessels.

Researchers have also examined nonpharmaceutical approaches. A handheld device that transmits brief pulses of magnetic stimulation is being evaluated, for example, for the treatment of migraine with and without aura. The premise is that this technology, called transcranial magnetic stimulation, or TMS, may interrupt cortical spreading depression and possibly prevent pain from arising or progressing.

For millions of people, these developments mark a breakthrough—not only in terms of relief from pain if all goes well but also in regard to attitudes about migraine. Scientists and physicians are finally coming to see migraine for the complex, biologically fascinating process it is and to recognize its powerfully debilitating effects. The disorder is "imaginary" no longer.

http://www.sciam.com/article.cfm?id=why-migraines-strike

Mr Valles, here's evidence that math is not innate.

2008-07-18T13:55:00.001+08:00

it seems 1, 2, many, much doesn't even put it.

Counting is one of the first things we teach our kids. I mean, every parent’s probably said, “You had better be in that bed by the time I count to three.” Followed by “One…two…two-and-a-half…” But counting might not be as universal as it seems. Because scientists from M.I.T. have found that a tribe living in the Amazon has no words for numbers.
Back in 2004, the M.I.T. team reported that the Piraha people seemed to have terms that described “one,” “two,” or “many.” This was based on asking tribe members to count objects, like sticks or nuts or AA batteries, as the researchers laid them out. This time, the scientists had the subjects count backward as they removed things. And they discovered that tribe members used the word previously thought to mean “two” for as many as five or six objects. And they used the word “one” for anything less than that. So the words don’t stand for numbers, so much as relative amounts. The findings appear in the online edition of the journal Cognition.
Although the Piraha people might not need numbers, think of what they’re missing. “A large number of trombones led the big parade, with an even larger number of cornets close at hand…”

http://www.sciam.com/podcast/episode.cfm?id=3124266A-AADE-2EB6-5A6402D740B0658F&sc=rss

This bird is pro….

2008-07-17T21:43:00.001+08:00

http://news.nationalgeographic.com/news/2008/07/080716-ukbird-video-ap.html

I wonder how to rip that video and embed it in my blog though..

New findings for TEMs

2008-07-17T21:40:00.001+08:00

Wow, finally we can actually see a hydrogen atom directly…

Single atoms spied on graphene sliver

Electron microscope spots hydrogen atoms resting on invisible carbon sheet.

Katharine Sanderson

The smallest of atoms can now be seen sitting in splendid isolation with a standard transmission electron microscope, thanks to the most fashionable form of carbon, graphene.

The technique, developed by scientists at the University of California, Berkeley, and the Lawrence Berkeley National Laboratory, California, could help to produce images of individual molecules in atomic detail using relatively conventional laboratory kit. The research is reported in this week's Nature¹.

A transmission electron microscope (TEM) works by firing a beam of electrons through a very thin sample supported by a scaffold. Electrons are scattered to different degrees by different atoms — heavier atoms containing more electrons tend to repel the electron beam to a greater extent, which translates as a brighter spot in the TEM image.

The transmission electron microscope reveals hydrogen atoms (purple) lying on a graphene sheet (red) with a single carbon atom (yellow tipped) in the centre.Nature

"Historically, light atoms have been very hard to image in the TEM," says Alex Zettl, who led the team. The problem is that in many fields of science, light atoms such as carbon, hydrogen, oxygen and nitrogen – the four major components of organic molecules – are the most interesting to study.

The solution arrived thanks to a little bit of luck, recalls Jannik Meyer, who was part of the Berkeley team but now works at the University of Ulm in Germany. Meyer was using standard laboratory TEM to study an individual sheet of graphene — which comprises a single layer of carbon atoms arranged into a flat, honeycomb pattern.

But he noticed that tiny impurities were sitting on top of the graphene sheet. "We were just trying to get the best signal-to-noise ratio," explains Meyer. "But I was surprised to see these atoms and see how stable they were."

By comparing the changes in the electron beam to theoretical values for the expected scattering, the team verified that they were indeed seeing single carbon and hydrogen atoms. Meyer thinks that the atoms form chemical bonds with the graphene, and that these hold them in place long enough to be detected with the TEM.

And the evenly-spaced carbon atoms in graphene are so close together that they are almost invisible to the TEM, making stray atoms even more conspicuous. "If you put additional atoms on top of the [graphene] grid, the grid is giving you a background," says Zettl.

High hopes

"This is something that was a little unexpected," says John Silcox, who develops electron spectroscopy techniques at Cornell University, Ithaca, New York. "Having an atomic grid that seems to be so stable and robust under an electron beam is going to be a great boost to seeing how individual atoms interact," he says. "I have high hopes that it will improve the ability to determine where the atoms are in sizeable molecules."

Small hydrocarbon chains were also present as contaminants in the TEM's sample chamber, and Meyer managed to film them as they moved around on the graphene surface. This means that small molecules could potentially be tracked as they react, or the mechanics of DNA followed in great detail, Zettl suggests.

Graphene grids could easily be used with any standard TEM, improving the sensitivity vastly, says Zettl, adding that his own is by no means the highest resolution on the market.

"In principle, using our sample foil with a higher-resolution machine you would be able to see every atom in a molecule," says Zettl. "I think a lot of people will jump forward and start using this in their TEMs. They'll be able to image whatever molecules and atoms they like."

References
- Meyer, J. C., Girit, C. O., Crommie, M. F. & Zettl, A. Nature 454, 319–322 (2008)

http://www.nature.com/news/2008/080716/full/news.2008.958.html?s=news_rss

the black and white of me

technological lessons from nature...

differentiation

ooh airheaded reptiles

hypocrisy, another fact that we need to think about..

The Truth about Hypocrisy

Charges of hypocrisy can be surprisingly irrelevant and often distract us from more important concerns

ants-fungus-bacterium: 3 way mutualism. nature still surprises us.

if i had fingers that fast, i could pinch off flesh

Panamanian Termite Goes Ballistic: Fastest Mandible Strike In The World

beetles with antibiotics

Some Beetles Can Quickly Neutralize Bacteria And Reduce Emergence Of Resistant Bacteria At Same Time

is it worth it?

a plastic brain. interesting.

Forgotten But Not Gone: How The Brain Re-learns

should probably stop getting surprised at what earth can offer.

New Life Beneath Sea And Ice

fatal to dawin theory? creationists, take that!

Darwin Was Right About How Evolution Can Affect Whole Group

catalytic power of emzymes

Without Enzyme, Biological Reaction Essential To Life Takes 2.3 Billion Years

another you

Female models and male self consciousness

Sexy red one, male brain zero

more ironies: skin moisturizing cream makes skins dryer

hmm, expected i guess? just like taking medicine, or painkillers, the more you take, the less your body is adapted to it.

Skin Creams Can Make Skin Drier

twitter?

Ancient microbes made giant magnets

Here be giants

Perfect climate

References

Again, women takes the backseat in research front..

Enzymes that do TWO things! Whoa!

Not kidding. This article is not for the faint of heart.

Ig Nobel Prize.. what the heck??

Follow the leader

And why I laugh at you XD, More sleep = better study.

What’s cooking? Ask my pet wasps XD

OOOH, scientific backing to gossip XD

Cool stuff XD

Zen Meditation reduces stress. Sort of..

Tree produces electricity

Muscle stem cells exist! -.-

Muscle Stem Cell Identity Confirmed By Researchers

where command economy fails and market economy succeeds

I can't believe this

So we google what we hear…

stupid things done by stupid people

Smart people? (not me)

Quiz for everyone!

Putting known concepts together..

free will (the actual post)

free will?

Free Will vs. the Programmed Brain

If our actions are determined by prior events, then do we have a choice about anything—or any responsibility for what we do?

it appears that this idea also exists in bacteria.

Kamikaze bacteria illustrate evolution of co-operation

Kamikaze genes

Change of strategy

References

hmm, so there's fat cells that remove fat.. interesting.

Boosting 'good' fat to burn off the bad

Fuel for the fire

References

free labour!!!

If You Use the Web, You May Have Already Been Enlisted as a Human Scanner

Those anti-bot security forms that slow you down when you're entering information just might serve a larger purpose

ancient civilizations! XD

Ah, a scientific research to the phrase “learning from mistakes”

Are Viruses Alive?

Must read! All who lack sleep!

HA i knew viruses were alive! not that this makes it any clearer -.-

'Virophage' suggests viruses are alive

References

Synaesthesia: a world of wonders

OOO monster…

Other catalyst for hydrogen…

School project? Crazy effort more like.

Migraines