Chapter 16. None

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A study suggests that a chemical in dark chocolate and red wine can slow the progression of Alzheimer’s disease. But how conclusive is the data, and does this mean we should all drink more wine? New Scientist looks at the evidence. What is resveratrol? Found in grapes, red wine and dark chocolate, many claims have been made about resveratrol. It has been touted as a potential panacea for a range of age-related disorders, including cancer, diabetes and neurological problems, but so far most of the data supporting these claims has come from lab studies and work in animals. There have been only a few, small studies in humans. How might resveratrol protect us from age-related illness? Extremely calorie-restricted diets greatly reduce age-related diseases in lab animals. This is thought to happen through the activation of a group of enzymes called sirtuins, which seem to affect gene expression and protect against the effects of stress, including a poor diet. The hope is that resveratrol activates sirtuins to get the same benefits – like preventing the onset of age-related diseases, including Alzheimer’s – without having to stick to such a low-energy diet. But some experiments have suggested slowed ageing from caloric restriction may not be down to sirtuins after all. What does the latest study show? To see if resveratrol could delay the progression of Alzheimer’s disease in people , Scott Turner at Georgetown University Medical Centre in Washington DC and his team gave 119 people with mild to moderate symptoms of the disease either a gram of synthesised resveratrol twice a day in pills for a year, or a placebo. © Copyright Reed Business Information Ltd.

Keyword: Alzheimers
Link ID: 21404 - Posted: 09.14.2015

James Gorman If spiders had nightmares, the larvae of ichneumonid wasps would have to star in them. The wasp lays an egg on the back of an orb weaver spider, where it grows fat and bossy, and occupies itself with turning the spider into a zombie. As Keizo Takasuka and his colleagues point out in The Journal of Experimental Biology, this is a classic case of “host manipulation.” Using more colorful language, he described the larva turning the spider into a “drugged navvy.” The larva forces the spider to turn its efforts away from maintaining a sticky, spiral web to catch prey, and to devote itself to building a safe and sturdy web to serve as a home for the larva’s cocoon, in which it will transform itself into a wasp. This process was well known, but Dr. Takasuka and Kaoru Maeto at Kobe University, working with other Japanese researchers, wanted to explore how the wasp overlords controlled their spiders. They suspected that the larvae were co-opting a natural behavior of the spiders. Turning on a behavior already in the spiders’ repertoire would be much easier than controlling every step of modifying a sticky web. So they compared the cocoon web to one that the spiders themselves build to rest in when they are molting. It’s called a resting web. The similarities were striking. In both the resting and cocoon webs, the sticky, spiraling threads that make the webs of orb weavers so appealing were gone. Instead, the spokes of the web remained, decorated with fibrous spider silk that the researchers found reflected ultraviolet light. That would be a highly useful quality to warn away birds and some large insects from flying into the web because those creatures can see in the ultraviolet spectrum. The strength of the two silk webs was also similar. © 2015 The New York Times Company

Keyword: Miscellaneous; Evolution
Link ID: 21403 - Posted: 09.14.2015

Mo Costandi At some point back in deep time, a group of fish were washed into a limestone cave somewhere in northeastern Mexico. With no way out and little more than bat droppings to eat, the fish began to adapt to their new troglodytic lifestyle. Unable to see other members of their group in the dark, they lost their colourful pigmentation. Then they lost their eyesight, their eyes gradually got smaller, and then disappeared altogether. This was accompanied by a dramatic reduction in the size of the brain’s visual system. Yet, the question of why the blind cave fish lost its eyes and a large part of its brain remains unresolved. Now, biologists in Sweden believe they have found the answer. In new research published today, they report that loss of the visual system saves the fish a substantial amount of energy, and was probably key to their stranded ancestors’ survival. The blind cave fish Astyanax mexicanus is adapted to its subterranean environment in other ways. As its vision regressed, it became more reliant on smell and taste, and its taste buds grew larger and more numerous. They also developed an enhanced ability to detect changes in mechanical pressure, which made them more sensitive to water movements. Last year, Damian Moran of Lund University and his colleagues reported that blind cave fish eliminated the circadian rhythm in their metabolism during their course of evolution, and that this leads to a massive 27% reduction in their energy expenditure. This new study was designed test whether or not they lost their visual system for the same reason. © 2015 Guardian News and Media Limited

Keyword: Evolution; Vision
Link ID: 21401 - Posted: 09.12.2015

Eating two and a half times more than you should will leave you overweight and prone to type 2 diabetes, although no one is entirely sure why. Now a team that fed volunteers a whopping 6000 calories a day have found some clues. Obesity is only one problem caused by eating too much. An overly large food intake can also increase a person’s risk of diabetes, heart disease and some cancers, but no one is sure why this should be the case. Resistance to the hormone insulin seems to play a role. When a healthy person eats a meal, their blood glucose levels rise, and the body responds by making insulin. This hormone prompts the body to store un-needed glucose, but people who develop insulin resistance are not able to absorb excess glucose in the same way. This means that, after eating, their blood glucose levels remain high, and over time, this can damage the kidneys, nervous system and heart, for example. Guenther Boden and Salim Merali at Temple University, Philadelphia, and their team set out to investigate how overeating might lead to insulin resistance. They fed six healthy male volunteers 6000 calories’ worth of food every day for a week – around two and a half times what they should have been eating. “It was a regular, American diet, composed of pizzas, hamburgers and that sort of thing,” says Merali. Each volunteer stayed at a hospital for the duration of the experiment, where they were bed-bound, carefully monitored and prevented from doing any sort of exercise. © Copyright Reed Business Information Ltd.

Keyword: Obesity
Link ID: 21400 - Posted: 09.12.2015

Ever waited for a bus rather than take the short walk to work? Headed for the escalator instead of the stairs? Humans clearly harbour a deep love of lethargy – and now we know how far people will go to expend less energy. We will change our walking style on the fly when our normal gait becomes even a little more difficult. The finding could have implications for the rehabilitation offered to people with spinal injuries. Jessica Selinger and her colleagues at Simon Fraser University in Burnaby, British Columbia, Canada, strapped volunteers into a lightweight robotic exoskeleton and put them on a treadmill. Initially, the team let the volunteers find their preferred walking rhythm – which turned out to be 1.8 steps per second, on average. Then the researchers switched on the exoskeleton, programming it to make it more difficult for the volunteers to walk at their preferred pace by preventing the knee from bending – and leg swinging – as freely. The exoskeleton didn’t interfere with the human guinea pigs’ ability to walk faster or slower than they preferred. Within minutes the volunteers had found a walking style that the exoskeleton would allow without offering resistance. Remarkably, though, they did so despite the fact that the exoskeleton only ever offered minimal resistance. By using breathing masks to analyse the volunteers’ metabolic activity, Selinger’s team found that subjects would shift to an awkward new gait even if the energy saving was only 5 per cent. “People are able to adapt and fine-tune in order to move in the most energetically optimal way,” says Selinger. “People will change really fundamental characteristics of their gait.” © Copyright Reed Business Information Ltd.

Keyword: Movement Disorders
Link ID: 21398 - Posted: 09.11.2015

By JOHN NOBLE WILFORD Acting on a tip from spelunkers two years ago, scientists in South Africa discovered what the cavers had only dimly glimpsed through a crack in a limestone wall deep in the Rising Star Cave: lots and lots of old bones. The remains covered the earthen floor beyond the narrow opening. This was, the scientists concluded, a large, dark chamber for the dead of a previously unidentified species of the early human lineage — Homo naledi. The new hominin species was announced on Thursday by an international team of more than 60 scientists led by Lee R. Berger, an American paleoanthropologist who is a professor of human evolution studies at the University of the Witwatersrand in Johannesburg. The species name, H. naledi, refers to the cave where the bones lay undisturbed for so long; “naledi” means “star” in the local Sesotho language. In two papers published this week in the open-access journal eLife, the researchers said that the more than 1,550 fossil elements documenting the discovery constituted the largest sample for any hominin species in a single African site, and one of the largest anywhere in the world. Further, the scientists said, that sample is probably a small fraction of the fossils yet to be recovered from the chamber. So far the team has recovered parts of at least 15 individuals. “With almost every bone in the body represented multiple times, Homo naledi is already practically the best-known fossil member of our lineage,” Dr. Berger said. The finding, like so many others in science, was the result of pure luck followed by considerable effort. Two local cavers, Rick Hunter and Steven Tucker, found the narrow entrance to the chamber, measuring no more than seven and a half inches wide. They were skinny enough to squeeze through, and in the light of their headlamps they saw the bones all around them. When they showed the fossil pictures to Pedro Boshoff, a caver who is also a geologist, he alerted Dr. Berger, who organized an investigation. © 2015 The New York Times Company

Keyword: Evolution
Link ID: 21396 - Posted: 09.11.2015

Bill McQuay and Christopher Joyce Acoustic biologists who have learned to tune their ears to the sounds of life know there's a lot more to animal communication than just, "Hey, here I am!" or "I need a mate." From insects to elephants to people, we animals all use sound to function and converse in social groups — especially when the environment is dark, or underwater or heavily forested. "We think that we really know what's going on out there," says Dartmouth College biologist Laurel Symes, who studies crickets. But there's a cacophony all around us, she says, that's full of information still to be deciphered. "We're getting this tiny slice of all of the sound in the world." Recently scientists have pushed the field of bioacoustics even further, to record whole environments, not just the animals that live there. Some call this "acoustic ecology" — listening to the rain, streams, wind through the trees. A deciduous forest sounds different from a pine forest, for example, and that soundscape changes seasonally. Neuroscientist Seth Horowitz, author of the book The Universal Sense: How Hearing Shapes the Mind, is especially interested in the ways all these sounds, which are essentially vibrations, have shaped the evolution of the human brain. "Vibration sensitivity is found in even the most primitive life forms," Horowitz says — even bacteria. "It's so critical to your environment, knowing that something else is moving near you, whether it's a predator or it's food. Everywhere you go there is vibration and it tells you something." © 2015 NPR

Keyword: Hearing; Evolution
Link ID: 21394 - Posted: 09.10.2015

By Siri Carpenter Alex, age 10, bounds onto his bed to pose with his Aaron Rodgers poster, grinning as proudly as if he had recruited the Green Bay Packers’ quarterback himself. Continuing the tour of his suburban New York bedroom, he points out his Packers-themed alarm clock, his soccer trophy, his Boy Scout trophy, and then the big reveal: a homemade foam box in Packers green and gold. “Mmm, very nice,” I say. Alex grins—part shy, part sly—as he turns it around to show me the message on the back: “Jets stink.” Even though he seems to be an entirely ordinary boy, there’s something unusual about Alex: He once had autism, and now he does not. There was a time when Alex’s parents didn’t know if he would ever speak in full sentences, let alone joke around with a stranger. His autism, they suspected, might prevent any such future. Alex’s parents began to worry about him before he was even a year old. He wasn’t learning to sit, crawl, or stand as his fraternal twin brother was. Even more striking was how much less social he was than his brother. “Alex was an expressionless child,” says his mother, Amy. (Alex’s and Amy’s names have been changed to protect their privacy.) She remembers a friend trying in vain to get Alex to laugh—jumping up and down, gesturing wildly, making silly faces. “His brother would be in belly laughs, and Alex would be just glazed over,” Amy says. © 2015 The Slate Group LLC.

Keyword: Autism
Link ID: 21393 - Posted: 09.10.2015

By Ann Gibbons From the moment in 2013 when paleoanthropologist Lee Berger posted a plea on Facebook, Twitter, and LinkedIn for “tiny and small, specialised cavers and spelunkers with excellent archaeological, palaeontological and excavation skills,” some experts began grumbling that the excavation of a mysterious hominin in the Rising Star Cave in South Africa was more of a media circus than a serious scientific expedition. Daily blogs recorded the dangerous maneuvers of “underground astronauts” who squeezed through a long, narrow chute to drop 30 meters into a fossil-filled cavern, while Berger, who is based at the University of the Witwatersrand in Johannesburg, South Africa, became the “voice from the cave” in radio interviews. When it came time to analyze the fossils, Berger put out a call for applications from “early career scientists” to study them at a workshop in Johannesburg in March 2014. Handing over much of the analysis of such potentially important specimens to inexperienced researchers didn’t inspire confidence among Berger’s colleagues either, though it did win him the nickname Mr. Paleodemocracy. Many thought the expedition “had more hype than substance,” paleoanthropologist Chris Stringer of the Natural History Museum in London writes in a commentary accompanying the fossils’ official presentation this week in the journal eLIFE. But the substance has now been unveiled, and few dispute that the findings are impressive. In their report, Berger and his team describe 1550 fossils representing more than 15 ancient members of a strange new kind of hominin, which they named Homo naledi. (Naledi means “star” in the Sotho language spoken in the region of the cave.) © 2015 American Association for the Advancement of Science.

Keyword: Evolution
Link ID: 21392 - Posted: 09.10.2015

By Steve Mirsky It's nice to know that the great man we celebrate in this special issue had a warm sense of humor. For example, in 1943 Albert Einstein received a letter from a junior high school student who mentioned that her math class was challenging. He wrote back, “Do not worry about your difficulties in mathematics; I can assure you that mine are still greater.” Today we know that his sentiment could also have been directed at crows, which are better at math than those members of various congressional committees that deal with science who refuse to acknowledge that global temperatures keep getting higher. Studies show that crows can easily discriminate between a group of, say, three objects and another containing nine. They have more trouble telling apart groups that are almost the same size, but unlike the aforementioned committee members, at least they're trying. A study in the Proceedings of the National Academy of Sciences USA finds that the brain of a crow has nerve cells that specialize in determining numbers—a method quite similar to what goes on in our primate brain. Human and crow brains are substantially different in size and organization, but convergent evolution seems to have decided that this kind of neuron-controlled numeracy is a good system. (Crows are probably unaware of evolution, which is excusable. Some members of various congressional committees that deal with science pad their reactionary résumés by not accepting evolution, which is astonishing.) © 2015 Scientific American

Keyword: Intelligence; Attention
Link ID: 21390 - Posted: 09.09.2015

By Susan Milius The larger Pacific striped octopus hunts shrimp using a strategy worthy of a schoolyard prank. And that’s not the only oddity about the species. It’s only the second octopus known with females that prolong motherhood, instead of dying after weeks of all-out coddling a single brood. But what everyone wants to talk about, researchers who study the species have found, is beak-to-beak mating. Before writhing, wrestling videos of the larger Pacific striped octopus (nicknamed LPSO), biologists knew of two forms of eight-armed sex. Some species mate at a distance, says Roy Caldwell of the University of California, Berkeley. The male extends one arm, always the same one, toward the female and up under her mantle. A travel-ready package of sperm emerges onto his skin and settles into a specialized groove on his mating arm. Waves of arm flexing resembling mammal intestinal motions nudge the packet toward one of two openings to her reproductive tracts. “It’s a messy way of reproducing,” Caldwell says. A lot of sperm packets “are wasted and go floating off.” Distance mating has other challenges. In an Indonesian octopus species, Caldwell’s former student Christine Huffard of the Monterey Bay Aquarium Research Institute discovered males hunkered in their dens sending an arm across the seafloor into the den of the female next door. On occasion, such females leave their dens on some octopus errand, dragging the male along by his mating arm. © Society for Science & the Public 2000 - 2015.

Keyword: Sexual Behavior
Link ID: 21389 - Posted: 09.09.2015

By Emily Chung, Whadd'ya at? Ow ya goin'? If you were at a picnic with a bunch of Newfoundlanders or Australians, those are the greetings you might fling around. Similarly, scientists who eavesdrop on sperm whales – Moby Dick's species — have found they also have distinct "dialects." And a new study suggests like human dialects, they arise through cultural learning. "Cultural transmission seems key to the partitioning of sperm whales into… clans," the researchers wrote in a paper published today in the journal Nature Communications. Sperm whales live around the world, mainly in deeper waters far offshore. The solitary males live in colder areas, and roam in Canadian waters in areas where the ocean depth is more than 1000 metres, says Mauricio Cantor, the Dalhousie University PhD. student who led the new study with Hal Whitehead, a Dalhousie biology professor. The females live in warmer, more southern waters, in loose family groups of around seven to 12 whales – sisters, aunts, grandmothers, cousins, and the occasional unrelated friend and their calves. Sometimes, they meet up with other families for gatherings of up to 200 whales, similar to human picnics or festivals. These can last from a few hours to a few days. The whales that gather in these groups, called clans, have distinct "dialects" of patterns of clicks called codas that are distinct from the clicks they use in echolocation when they're hunting for food. They use codas talk to each other when they surface between dives. ©2015 CBC/Radio-Canada.

Keyword: Language; Evolution
Link ID: 21388 - Posted: 09.09.2015

By Bruce Bower Lemurs don’t yawn in the face of danger. They wait a few minutes after perils have passed before breaking into breathy mouth gapes. Lemurs in a southern Madagascar reserve yawned frequently within 10 minutes of fighting with other lemurs, surviving attacks by predatory birds and coming close to snakes, tourists or other potential dangers, primatologist Elisabetta Palagi of the University of Pisa in Italy and her colleagues report August 28 in the American Journal of Primatology. Lemurs largely stopped yawning after that brief outburst. This pattern held for 13 ring-tailed lemurs and 15 Verreaux’s sifakas tracked daily for three months in 2011. Recurring dangers that lemurs learn to escape or avoid elicit moderate, brief anxiety, the researchers suspect. Yawning amps up as animals rapidly return to calmness, much as it increases when lemurs take rest breaks during the day, Palagi’s team says. Many physiological and social forces contribute to yawning, they add. Citations A. Zannella et al. Testing yawning hypotheses in wild populations of two strepsirrhine species: Propithecus verreauxi and Lemur catta. American Journal of Primatology. Published August 28, 2015. doi:10.1002/ajp.22459. © Society for Science & the Public 2000 - 2015.

Keyword: Emotions
Link ID: 21387 - Posted: 09.09.2015

A particular region of the brain may drive smoking addiction, say scientists who found stroke survivors with damage to their insular cortex more easily kicked the habit. They studied 156 stroke patients with different patterns of brain injury. More of those with insular cortex damage successfully gave up smoking and reported fewer withdrawal symptoms than the other stroke patients. Experts say targeting this brain area may help other smokers quit. Most stop smoking medicines currently on the market work by blocking the brain's reward pathways in response to nicotine. And patches and gums aim to lessen cravings by supplying a controlled dose of nicotine as the person weans themselves off tobacco. But post-graduate researcher Amir Abdolahi and colleagues believe the insular cortex could be a valuable new target for quit smoking aids. Therapies that could hone in on this area of the brain and disrupt its role in addiction, potentially with new drugs or other techniques such as deep brain stimulation or transcranial magnetic stimulation, should be explored, they say. "Much more research is needed in order for us to more fully understand the underlying mechanism and specific role of the insular cortex, but it is clear that something is going on in this part of the brain that is influencing addiction," Mr Abdolahi said. The research findings are published in two medical journals - Addiction and Addictive Behaviors. The patients in the study were smokers who had been admitted to hospital because of a stroke. Medical scans revealed that 38 of them had suffered damage to the insular cortex, while the remaining 118 had damage to other parts of the brain. All of the patients were encouraged by their doctor to quit smoking. © 2015 BBC.

Keyword: Drug Abuse
Link ID: 21385 - Posted: 09.08.2015

By Michael Balter If you find yourself along the Atlantic coastal border between Spain and France, here are some phrases that might come in handy: Urte askotarako! (“Pleased to meet you!”), Eskerrik asko! (“Thank you!”), and Non daude komunak? (“Where is the toilet?”). Welcome to Basque Country, where many people speak a musical language that has no known relationship to any other tongue. Many researchers have assumed that Basque must represent a “relic language” spoken by the hunter-gatherers who occupied Western Europe before farmers moved in about 7500 years ago. But a new study contradicts that idea and concludes that the Basques are descended from a group of those early farmers that kept to itself as later waves of migration swept through Europe. The great majority of Europeans speak languages belonging to the Indo-European family, which includes such diverse tongues as German, Greek, Spanish, and French; a smaller number speak Uralic languages like Finnish, Hungarian, and Estonian. But Basque stands truly alone; what linguists call a “language isolate.” This uniqueness is a source of pride among the nearly 700,000 Basque speakers, some of whom have called for the creation of an independent nation separate from Spain and France. For scientists, however, Basque is a major unsolved mystery. In the 19th century, some anthropologists claimed that Basques had differently shaped skulls than other Europeans. Yet although that racial idea had been discredited by the 20th century, researchers have been able to show that the Basques have a striking number of genetic differences that set them apart from other Europeans. Variations in their immune cells and proteins include a higher-than-normal frequency of Rh-negative blood types, for example. Those findings led to the hypothesis that the Basques descended from early hunter-gatherers who had somehow avoided being genetically overwhelmed when farming spread into Europe from the Near East. But some recent studies have questioned just how genetically distinct the Basques really are. © 2015 American Association for the Advancement of Science.

Keyword: Language
Link ID: 21384 - Posted: 09.08.2015

Erin Wayman Nose picking isn’t a mark of distinction among people — but it is among monkeys. For the first time, researchers have reported a wild capuchin monkey using a tool to pick its nose and teeth. The monkey was caught in the act last year by Michael Haslam of the University of Oxford. For about five minutes, an adult female bearded capuchin (Sapajus libidinosus) in northeastern Brazil repeatedly inserted a twig or stem into its nostril, usually inducing a sneeze. The monkey also rubbed sticks back and forth against the base of its teeth, probably to dislodge debris, Haslam and Oxford colleague Tiago Falótico report in the July Primates. After picking its nose or teeth, the monkey often licked the tool tip, perhaps to wipe the stick clean. Bearded capuchins are quite handy, brandishing rocks to crack open nuts (SN Online: 4/30/15) and sticks to retrieve insects from crevices or to collect honey. But until now, no one had seen a wild capuchin use a tool as a nasal probe or toothpick. M. Haslam and T. Falótico. Nasal probe and toothpick tool use by a wild female bearded capuchin (Sapajus libidinosus). Primates. Vol. 56, July 2015, p. 211. doi: 10.1007/s10329-015-0470-6. © Society for Science & the Public 2000 - 2015

Keyword: Evolution
Link ID: 21382 - Posted: 09.08.2015

By Olivia Campbell Leave it to childbirth to cause a woman who’s never felt pain in her life to now experience persistent discomfort. When a 37-year-old woman with a condition known as congenital insensitivity to pain gave birth, her labor was as painless as expected. But during the delivery, she sustained pelvic fractures and an epidural hematoma that impinged on a nerve in her lower spine. Since then, she has added an unfortunate variety of words to her vocabulary: Her hips “hurt” and “ache;” she feels a “continuous buzzing in both legs and a vice-like squeezing in the pelvis.” When resting, she is left with “tingling” and “electric shocks.” She now has headaches, backaches, period pains, and stomach cramps; and even describes “the sting” of a graze and “the sharpness” of an exposed gum. According to doctors who treated her, the woman's sensitivity to pain -- tested on the tops of her feet -- is 10 times higher than it was before she gave birth. Congenital insensitivity to pain is an incredibly rare genetic disorder — there are only 20 recorded cases — that causes individuals to be totally unaware of pain. Co-author of the paper Michael Lee explained how pain pathways start with specialized nerves, called nociceptors, that sense damaging temperatures or pressure and then fire off signals to the brain. Those signals make us feel pain to prevent further damage. In people with CIP, a defective gene prevents these signals from going through. But pain can also arise when nociceptors or nerves are damaged, as was the case when this woman’s lumbar nerve was pinched during childbirth.

Keyword: Pain & Touch
Link ID: 21379 - Posted: 09.03.2015

In 1938, an Austrian pediatrician named Hans Asperger gave the first public talk on autism in history. Asperger was speaking to an audience of Nazis, and he feared that his patients — children who fell onto what we now call the autism spectrum — were in danger of being sent to Nazi extermination camps. As Asperger spoke, he highlighted his "most promising" patients, a notion that would stick with the autistic spectrum for decades to come. "That is where the idea of so-called high-functioning versus low-functioning autistic people comes from really — it comes from Asperger's attempt to save the lives of the children in his clinic," science writer Steve Silberman tells Fresh Air's Terry Gross. Silberman chronicles the history of autism and examines some of the myths surrounding our current understanding of the condition in his new book, NeuroTribes. Along the way, he revisits Asperger's calculated efforts to save his patients. Steve Silberman's articles have been published in Wired, The New Yorker, Nature and Salon. Silberman shies away from using the terms high-functioning and low-functioning, because "both of those terms can be off base," he says. But he praises Asperger's courage in speaking to the Nazis. "I would literally weep while I was writing that chapter," he says. NeuroTribes also explores how a 1987 expansion of the medical definition of autism (which was previously much narrower and led to less frequent diagnoses) contributed to the perception that there was an autism epidemic. © 2015 NPR

Keyword: Autism
Link ID: 21378 - Posted: 09.03.2015

Boer Deng Palaeontologist Stephen Gatesy wants to bring extinct creatures to life — virtually speaking. When he pores over the fossilized skeletons of dinosaurs and other long-dead beasts, he tries to imagine how they walked, ran or flew, and how those movements evolved into the gaits of their modern descendents. “I'm a very visual guy,” he says. But fossils are lifeless and static, and can only tell Gatesy so much. So instead, he relies on XROMM, a software package that he developed with his colleagues at Brown University in Providence, Rhode Island. XROMM (X-ray Reconstruction of Moving Morphology) borrows from the technology of motion capture, in which multiple cameras film a moving object from different angles, and markers on the object are rendered into 3D by a computer program. The difference is that XROMM uses not cameras, but X-ray machines that make videos of bones and joints moving inside live creatures such as pigs, ducks and fish. Understanding how the movements relate to the animals' bone structure can help palaeontologists to determine what movements would have been possible for fossilized creatures. “It's a completely different approach” to studying evolution, says Gatesy. XROMM, released to the public in 2008 as an open-source package, is one of a number of software tools that are expanding what researchers know about how animals and humans walk, crawl and, in some cases, fly (see ‘Movement from inside and out’). That has given the centuries-old science of animal motion relevance to a wide range of fields, from studying biodiversity to designing leg braces, prostheses and other assistive medical devices.“We're in an intense period of using camera-based and computer-based approaches to expand the questions we can ask about motion,” says Michael Dickinson, a neuroscientist at the California Institute of Technology in Pasadena. © 2015 Nature Publishing Group

Keyword: Movement Disorders
Link ID: 21370 - Posted: 09.01.2015

By LISA FELDMAN BARRETT Boston — IS psychology in the midst of a research crisis? An initiative called the Reproducibility Project at the University of Virginia recently reran 100 psychology experiments and found that over 60 percent of them failed to replicate — that is, their findings did not hold up the second time around. The results, published last week in Science, have generated alarm (and in some cases, confirmed suspicions) that the field of psychology is in poor shape. But the failure to replicate is not a cause for alarm; in fact, it is a normal part of how science works. Suppose you have two well-designed, carefully run studies, A and B, that investigate the same phenomenon. They perform what appear to be identical experiments, and yet they reach opposite conclusions. Study A produces the predicted phenomenon, whereas Study B does not. We have a failure to replicate. Does this mean that the phenomenon in question is necessarily illusory? Absolutely not. If the studies were well designed and executed, it is more likely that the phenomenon from Study A is true only under certain conditions. The scientist’s job now is to figure out what those conditions are, in order to form new and better hypotheses to test. A number of years ago, for example, scientists conducted an experiment on fruit flies that appeared to identify the gene responsible for curly wings. The results looked solid in the tidy confines of the lab, but out in the messy reality of nature, where temperatures and humidity varied widely, the gene turned out not to reliably have this effect. In a simplistic sense, the experiment “failed to replicate.” But in a grander sense, as the evolutionary biologist Richard Lewontin has noted, “failures” like this helped teach biologists that a single gene produces different characteristics and behaviors, depending on the context. © 2015 The New York Times Company

Keyword: Attention
Link ID: 21369 - Posted: 09.01.2015