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By LARRY O'HANLON Everyone looks better after you've tipped back a pint or two, and now we may know why. It turns out that alcohol dulls our ability to recognize cockeyed, asymmetrical faces, according to researchers who tested the idea on both sober and inebriated college students in England. To find out if alcohol interfered with the ability to distinguish faces where the left and right sides were uneven, he and his colleagues designed an experiment involving images of faces that were tinkered with to make them perfectly symmetrical or subtly asymmetrical. The results of the study were published by Halsey, Joerg Huber, Richard Bufton and A.C. Little in a recent issue of the journal Alcohol. "Over an evening Joerg, Richard and I went out to the university campus bars with a laptop and asked students to participate," Halsey said. Men appear to be less prone to losing this ability than women when drinking. This included students taking a quick breathalyzer test to confirm their alcohol consumption. The students were classified as either sober or intoxicated, then examined the images. © 2010 ABC News Internet Ventures.
Keyword: Drug Abuse; Sexual Behavior
Link ID: 14387 - Posted: 08.23.2010
By Katherine Harmon Children with autism often focus intently on a single activity or feature of their environment. New research might help to explain this behavioral trend, providing evidence that the brains of young people with autism are slower to integrate input coming from more than one sense at the same time. During study of the disorder decades ago, research into these basic tendencies was common. But in subsequent years, scientists have tended to focus more on complex issues, ranging from communication troubles to underlying genetic patterns. Recently, however, more studies have set their sights back on some of the simple processes that most people take for granted, such as sensory intake, as a way to better understand more high-level manifestations, such as social interaction issues. "We believe that these things interact in very significant ways," says Sophie Molholm, an associate professor of neuroscience at Albert Einstein College of Medicine and co-author of a new study about multi-sensory processing. The research, published online August 19 in Autism Research, used electroencephalograms (EEGs) to measure electrical activity in the brain through the scalp of subjects as they encountered various stimuli. Seventeen children (ages six to 16 years) with autism—and 17 age- and IQ-matched normally developing kids—watched a silent video of their choice throughout the testing. Meanwhile, tones and vibrations were administered in random order, sometimes separately, sometimes at the same time. The EEG readings were time-stamped to the stimuli and compared across all of the children to assess brain activity trends during single- and multi-sensory stimulation. Although the video presented visual stimuli, Molholm points out that because it was a consistent exposure throughout the experiments and the EEG readings were set to pick up on the sound and somatosensory stimuli and averaged out over so many tests, it becomes akin to "background brain activity that will sum to zero," she notes. "It's really just something to keep them busy." © 2010 Scientific American,
Keyword: Autism
Link ID: 14386 - Posted: 08.23.2010
By Susan Milius In a long-running war between bats and moths, at least one bat has gotten the upper wing. Western barbastelle bats in Europe typically ping out their echolocation calls softly enough to locate a moth for dinner before the moth hears them coming, says Holger Goerlitz of the University of Bristol in England. It’s the first documented case of a bat species outwitting its prey by quiet stealth, he and his colleagues say online in a Current Biology paper released August 19. The battle between bats and moths has become a classic system for studying the evolution of predators and their prey. In searching for moths, barbastelles echolocate at about the 94 decibel level, roughly the equivalent of a busy highway, Goerlitz reports. This bat version of whispering is 10 to 100 times lower in amplitude than other aerial-hunting bats’ echolocation calls. Those rank more in the range of jet engines and the vuvuzelas blaring at the latest World Cup, Goerlitz says. People can’t hear frequencies high enough to detect any of this bat racket — “quite lucky for us,” Goerlitz says. To measure the loudness of the barbastelle calls, researchers needed to know how far away from a microphone a flying bat was when it pinged. So they set up a microphone array where bats swooped through at night. The slight differences in times that the calls took to reach different microphones let researchers figure out the bat’s position for each of more than 100 calls. © Society for Science & the Public 2000 - 2010
Keyword: Hearing
Link ID: 14385 - Posted: 08.23.2010
By Emily Sohn Chemicals on our produce may contribute to behavior problems in our kids, suggest three new studies. The studies, which looked at a class of pesticides called organophosphates (OP), linked exposure to the chemicals with attention disorders in children, with perhaps the most dramatic impacts to kids who are exposed in the womb and those who are genetically most susceptible. Because pesticide residues linger on fruits and vegetables, the findings suggest that people either buy organic or take the time to wash their produce well. "We don't want women to not eat fruits and vegetables because it's very important to eat them during pregnancy," said Brenda Eskenazi, an epidemiologist and neuropsychologist at the University of California, Berkeley. "I just let water run really thoroughly over fruits, and I rub them so they're clean." Organophosphates are a set of common pesticides that work by attacking the nervous systems of insects. When people are exposed to high levels of the chemicals, they can develop anxiety, confusion impaired concentration, and other serious symptoms. More recently, scientists have started to wonder how chronic exposure at low levels might be affecting people, especially kids, whose nervous systems are still developing. To find out, Eskenazi and colleagues followed up on a long-term study that has tracked more than 300 Mexican-American women in an agriculturally intensive region of California since they first became pregnant in 1999 or 2000. When the women were pregnant, the researchers measured levels of pesticide breakdown products in their urine. More recently, they collected urine samples from the kids and evaluated measures of attention. © 2010 Discovery Communications, LLC.
Keyword: ADHD; Neurotoxins
Link ID: 14384 - Posted: 08.23.2010
By Steve Yanda Across the spectrum of athletics from youth soccer to the National Football League, concussions are one of the most worrisome of injuries: hard to diagnose and even harder to know when an athlete has recovered. Now, in an unusual combination of real sports and their digital imitators, a handful of colleges, including the University of Maryland, are turning to a video game for help. Athletic trainers in College Park and on other campuses are using the Wii Fit video game as an objective and practical -- if unproven -- method of assessing athletes' balance, an important yardstick for determining recovery from concussion. For the past year, Maryland and Ohio State have partnered to conduct research into the reliability of Wii Fit -- an exercise video game played on Nintendo's Wii console, which allows for physical interaction between player and game -- as an effective concussion management instrument. Darryl Conway, Maryland's head athletic trainer, said this will be the third year the school has used components of the game to conduct baseline testing of its athletes' balance. Proponents of using Wii Fit as a tool to examine concussions praise its simplicity and affordability -- not to mention its popularity with student-athletes. "The athletes love it because what we've done is we've incorporated this fun game that they're playing at home into their rehab system," said Tamerah Hunt, director of research at the Ohio State Sports Concussion Program. "But they're also enjoying it at a time when they're injured or at a time when their spirits are down, and they have to come into the athletic training room every day and they have to get all this treatment . . . and it's kind of a reaction of, 'Oh, this is fun.' " © 2010 The Washington Post Company
Keyword: Brain Injury/Concussion
Link ID: 14383 - Posted: 08.20.2010
By GINA KOLATA The failure of a promising Alzheimer’s drug in clinical trials highlights the gap between diagnosis — where real progress has recently been made — and treatment of the disease. It was not just that the drug, made by Eli Lilly, did not work — maybe that could be explained by saying the patients’ illness was too far advanced when they received it. It was that the drug actually made them worse, the company said. And the larger the dose they took, the worse were patients’ symptoms of memory loss and inability to care for themselves. Not only that, the drug also increased the risk of skin cancer. So when Lilly announced on Tuesday that it was ending its large clinical trials of that drug, semagacestat, researchers were dismayed. “Obviously, this is disappointing news, to say the least,” said Dr. Steven Paul, an Alzheimer’s researcher and a recently retired executive vice president at Lilly. Beyond the setback for Lilly, the study raises questions about a leading hypothesis of the cause of Alzheimer’s and how to treat it. The idea, known as the amyloid hypothesis, says the disease occurs when a toxic protein, beta amyloid, accumulates in the brain. The idea is that if beta amyloid levels are reduced, the disease might be slowed, halted or even prevented if treatment starts early enough. The Lilly drug, like most of the more than 100 Alzheimer’s drugs under development, blocks an enzyme, gamma secretase, needed to make beta amyloid. It was among the first shown to breach the blood-brain barrier and reduce levels of beta amyloid in the brain. And, company studies showed, it did reduce amyloid production. Copyright 2010 The New York Times Company
Keyword: Alzheimers
Link ID: 14382 - Posted: 08.20.2010
By HELEN EPSTEIN For the fortunate, pain is temporary and finite, with a clear beginning, middle and end. But for more than 70 million Americans, including Melanie Thernstrom, pain is chronic, and the primary reason that they seek medical care. The medical profession has been slow to recognize this development. There is currently one board-certified pain specialist in the United States for every 25,000 patients, she writes in her new book, “The Pain Chronicles.” That number, however, is likely to grow as pain is redefined not as a symptom but as a disease that “can eventually rewrite the central nervous system, causing pathological changes to the brain and spinal cord, and ... greater pain.” There have been hundreds of books published in the last decades on pain and its management, but none that combine memoir, scholarly research and journalistic reportage in the way Ms. Thernstrom, the author of two previous books, does. A stellar example of literary nonfiction (parts of which first appeared in The New York Times Magazine), the book recounts the author’s own years with chronic pain and the preconceptions she brought to it (including the idea of pain as the price for romantic love); summarizes its social, cultural and medical history; and gives us a reporter’s view of state-of-the-art treatment. The book has a patchwork quilt structure: more than one hundred small captioned patches (or dispatches), organized into five parts and threaded with personal narrative. This invites differently motivated readers to skip or skim. You can chuckle over the aperçus of poets and philosophers like Aristotle, Coleridge, Dickinson, Sontag, and Foucault in the section entitled “Pain as Metaphor.” You can become absorbed, as I was, in the fascinating struggle over the use of anesthesia (and, later, opiates) in “Pain as History,” or play voyeur during absorbing clinical vignettes of “Pain as Disease.” Copyright 2010 The New York Times Company
Keyword: Pain & Touch
Link ID: 14381 - Posted: 08.20.2010
By David Biello Ketamine—a powerful anesthetic for humans and animals that lists hallucinations among its side effects and therefore is often abused under the name Special K—delivers rapid relief to chronically depressed patients, and researchers may now have discovered why. In fact, the latest evidence reinforces the idea that the psychedelic drug could be the first new drug in decades to lift the fog of depression. "We were trying to figure out what ketamine was doing to produce this rapid response," which can take as little as two hours to begin to act, says neuroscientist Ron Duman of the Yale University School of Medicine. So Duman and his colleagues gave a small amount of ketamine (10 milligrams per kilogram of body weight) to rats and watched the drug literally transform the animals' brains. "Ketamine… can induce a rapid increase in connections in the brain, the synapses by which neurons interact and communicate with each other, " Duman says. "You can visually see this response that occurs in response to ketamine." More specifically, as the researchers report in the August 20 issue of Science, ketamine seems to stimulate a biochemical pathway in the brain (known as mTOR) to strengthen synapses in a rat's prefrontal cortex—the region of the brain associated with thinking and personality in humans. And the ketamine helped rats cope with the depression analog experience brought on by forcing the rodents to swim or exposing them to inescapable stress. "Preclinical and clinical studies show that repeated stress or depression can cause a decrease in connections and an atrophy of connections in the same region of the brain," Duman explains, noting that magnetic resonance imaging shows that some depressed patients have a smaller prefrontal cortex as a result. "Ketamine has the opposite effect and can oppose or reverse the effects of depression" for roughly seven days per dose. © 2010 Scientific American
Keyword: Depression; Drug Abuse
Link ID: 14380 - Posted: 08.20.2010
By Kay Lazar New research suggests that athletes who have had multiple head injuries, and possibly others such as military veterans exposed to repetitive brain traumas, may be prone to developing a disabling neurological disease similar to amyotrophic lateral sclerosis, also known as ALS or Lou Gehrig’s disease. A team of researchers from Boston University School of Medicine and the Veterans Administration Hospital in Bedford said yesterday they have pinpointed evidence of a new disease that mimics ALS in the brains of two former National Football League players previously thought to have died of ALS. They also found the new disease in the brain of a deceased professional boxer who was a military veteran. In most cases, ALS strikes people — many in the prime of life — with no apparent rhyme or reason. The progressive nerve disorder, which affects an estimated 30,000 Americans, slowly paralyzes patients while leaving their mind intact. But if this early research is borne out by autopsies of additional athletes and veterans, it would support the idea that an ALS-type illness can be triggered by the traumas of sports and war. “We believe that these three cases are the tip of the iceberg,’’ said neurosurgeon Robert Cantu, who is a codirector of the BU Center for the Study of Traumatic Encephalopathy. “We don’t know whether this is linked to the increased incidence of ALS in the military, who are subject to blasts and other head injuries, but we are concerned that it may be.’’ The findings, the authors speculated, could mean that athletes and some others previously diagnosed with ALS actually had the related syndrome — perhaps even Gehrig himself, the New York Yankees star who is the iconic ALS sufferer. It’s a mystery that will never be solved, however, because Gehrig’s body was cremated. © 2010 NY Times Co
Keyword: ALS-Lou Gehrig's Disease
; Brain Injury/Concussion
Link ID: 14379 - Posted: 08.20.2010
by Michael Balter Why cooperate when you can be selfish? Many animal behaviors are self-centered and apparently evolved to pass on an individual's genes to future generations. Yet cooperative breeding, in which some members of a group help others to raise their young, has evolved independently many times, especially in birds and insects. A new study of birds concludes that parents get more help when they are sexually faithful to each other. Cooperation has been called an evolutionary paradox, and cooperative breeding is relatively rare, with members of only 3% to 10% of bird species helping to raise one another's young. Among the apes, only humans are cooperative breeders, although monkeys such as marmosets and tamarins do it, too. In the 1960s, British biologist William Hamilton proposed that natural selection could favor cooperation if individuals pass on their own genes by helping relatives raise offspring. But Hamilton argued that cooperation can arise only if such helpers are closely related to recipients and if the benefits outweigh the costs. Over the past few years, Jacobus Boomsma, an evolutionary biologist at the University of Copenhagen, has argued that strict monogamous behavior, such as an ant queen mating for life, spurred the evolution of cooperative breeding in some social insects. Monogamy helps fulfill Hamilton's conditions, because all siblings are equally related to each other and to each parent. Promiscuity, on the other hand, leads to many half-siblings and lowers the relatedness of individuals in a group. © 2010 American Association for the Advancement of Science.
Keyword: Sexual Behavior; Evolution
Link ID: 14378 - Posted: 08.20.2010
By Nathan Seppa The prevalence of hearing loss in teenagers rose by nearly one-third in recent years compared with the rate in the 1980s and 1990s, a new study shows. The findings come as a surprise to the study’s authors, who had expected overall hearing to improve thanks to publicity about the risks of exposure to loud music and the advent of childhood vaccines against meningitis and pneumonia that can prevent many ear infections. But in the August 18 Journal of the American Medical Association, the scientists report that the portion of U.S. adolescents aged 12 to 19 with any hearing loss rose from 14.9 percent during the 1988 to 1995 period to 19.5 percent in 2005 and 2006. Researchers based the analysis on information gathered from nearly 3,000 kids in the earlier time frame and more than 1,700 in the later sampling. The findings suggest that as many as 6.5 million teens in the United States now have some hearing loss. The surveys used largely similar questionnaires and standard hearing tests in which “any hearing loss” was defined as a loss of 15 decibels in at least one ear. That is, a person was determined to have some hearing loss if a tone had to be increased by 15 dB or more beyond the standard detection level to be heard at least half the time. Hearing loss of 25 dB or greater is less common, particularly in children. But it also rose, from 3.5 to 5.3 percent, between the study time frames. The rate of hearing loss increased in high — but not low — frequencies, the researchers found. © Society for Science & the Public 2000 - 2010
Keyword: Hearing
Link ID: 14377 - Posted: 08.20.2010
by Jon Cohen Thirty-five years ago, researchers studying chimpanzees in the wild noticed that neighboring communities had distinct grooming behaviors that could not be explained by differences in their environments. They contended that these behavioral idiosyncrasies were learned, or "cultural," and other scientists soon began noting group-specific tool uses and courting behaviors that also didn't appear to be environmental. But in a new study, researchers say some of these behaviors may be genetic after all. Before that 1975 revelation, few researchers had observed different communities of wild chimpanzees, and no one had even recognized that these behavioral differences existed. Investigators have been arguing about whether chimps truly have culture ever since. Proponents of culture published a landmark Nature paper in 1999 documenting 39 behaviors that were frequently observed in some communities and never seen in others. In the article's wake, a flood of reports began to appear about culture in other species, and the debates roiled on, with endless discussions about the meaning of the word itself. The new study, published online tomorrow in the Proceedings of the Royal Society B, examines partial sequences of the mitochondrial DNA (mtDNA) from wild chimpanzees in nine different groups. This DNA is handy because it's inherited only from mothers, and only chimp females typically move to new communities. Team members examined the links between the groups and 38 of the 39 supposed cultural variants documented in the earlier report. The study does not link behaviors to specific genes or even conclude that there is a genetic explanation. Rather, it assesses whether genetic differences can be excluded as an explanation for each behavior; it finds that they cannot more than half the time. © 2010 American Association for the Advancement of Science.
Keyword: Evolution; Genes & Behavior
Link ID: 14376 - Posted: 08.20.2010
Scientists are closer to understanding what triggers muscle damage in one of the most common forms of muscular dystrophy, called facioscapulohumeral muscular dystrophy (FSHD). FSHD affects about 1 in 20,000 people, and is named for progressive weakness and wasting of muscles in the face, shoulders and upper arms. Although not life-threatening, the disease is disabling. The facial weakness in FSHD, for example, often leads to problems with chewing and speaking. The new research was funded in part by the National Institutes of Health and appears in the journal Science. Until now, there were few clues to the mechanism of FSHD and essentially no leads for potential therapies, beyond symptomatic treatments, said John Porter, Ph.D., a program director at NIH's National Institute of Neurological Disorders and Stroke (NINDS). "This study presents a model of the disease that ties together many complex findings, and will allow researchers to test new theories and potential new treatments," Dr. Porter said. In the early 1990s, researchers found that FSHD is associated with a shortened DNA sequence located on chromosome 4. Experts predicted that discovery of one or more FSHD genes was imminent, but while a handful of candidate genes gradually emerged, none of them were found to have a key role in the disease. The mysteries surrounding FSHD deepened in 2002 when researchers, led by Silvere van der Maarel, Ph.D., at Leiden University in the Netherlands, found that the shortened DNA sequence on chromosome 4 is not enough to cause FSHD. They discovered that the disease occurs only among people who have the shortened DNA sequence plus other sequence variations on chromosome 4. That work was funded in part by NIH, the FSH Society and the Muscular Dystrophy Association.
Keyword: Movement Disorders; Muscles
Link ID: 14375 - Posted: 08.20.2010
By Emily Sohn When a woman is ovulating, her behavior changes in a startling number of ways from the way she walks, talks and dresses to the men she flirts with, according to new research. The findings might offer some practical tips for women to boost their online dating prospects; for scientists to develop new kinds of ovulation detection kits; or for marketers to target sales of clothes and jewelry. The work also suggests that going on or off the birth control pill might influence a woman's choice in men. Why does ovulation change women's behavior in such subtle yet fundamental ways? Experts propose that it's an innate and subtle strategy to both attract the most desirable guys and convince them to stick around for the long haul. "The idea is that women turn up everything that has to do with femininity" at ovulation, said Greg Bryant, an evolutionary psychologist at the University of California, Los Angeles. "This is showing that there are all sorts of phenomena that happen in our behavior that we're not actually aware of." For a long time, scientists assumed that the hormonal shifts of ovulation happened without measurable changes in how women behaved. That's because women have a strong motivation to hide the fact that they're fertile, unlike other members of the animal kingdom. While a female baboon's swollen red rump encourages males to mate and go, for example, a female human's ability to keep a man guessing should up the chances of him mating and then staying to help take care of their children. © 2010 Discovery Communications, LLC.
Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 14374 - Posted: 08.20.2010
by Carl Zimmer Every spring the National Football League conducts that most cherished of American rituals, the college draft. A couple of months before the event, prospective players show off their abilities in an athletic audition known as the combine. Last winter’s combine was different from that of previous years, though. Along with the traditional 40-yard dashes and bench presses, the latest crop of aspirants also had to log time in front of a computer, trying to solve a series of brainteasers. In one test, Xs and Os were sprinkled across the computer screen as the athletes took a test that measured how well they could remember the position of each letter. In another, words like red and blue appeared on the screen in different colors. The football players had to press a key as quickly as possible if the word matched its color. These teasers are not intended to help coaches make their draft picks. They are for the benefit of the players themselves—or, to be more precise, for the benefit of the players’ gray matter. Under pressure from Congress, the N.F.L. is taking steps to do a better job of protecting its players from brain damage. The little computer challenges that the draft candidates had to solve measure some of the brain’s most crucial functions, such as its ability to hold several pieces of information at once. Given the nature of football, it is extremely likely that a number of this year’s draft picks will someday suffer a head injury on the field. After that happens, N.F.L. doctors will give them the same tests again. By comparing the new results with the baseline scores recorded just before the draft, the doctors will get a clearer sense of how badly the football players have damaged their brains and what degree of caution to take during recovery.
Keyword: Brain Injury/Concussion
Link ID: 14373 - Posted: 08.20.2010
Melissa Dahl In Michelle Philpots' world, Bill Clinton is still president, everyone keeps telling each other that "life is like a box of chocolates" and no one can get Ace of Base's "The Sign"out of their heads. That's because Philpots is stuck in 1994. That year, Philpots suffered traumatic brain injuries in two car crashes. Since then, she's been unable to form new memories; every morning, her husband has to convince her that they're married, using a photo album as proof -- a real-life version of the Adam Sandler-Drew Barrymore movie "50 First Dates." She can remember everything that happened to her until 1994, but nothing after that -- not even her 1997 marriage. (She started dating her husband before her injury, but doesn't remember marrying the guy.) Philpots, 47, who lives in Spalding, England, has an extreme case of anterograde amnesia, a condition that inhibits the brain's ability to record any new memories. Other amnesiacs can't recall older memories, a condition called called retrograde amnesia. Amnesia is a handy plot device in pop culture, and memory experts say real-life "Memento" cases are rare, but they do exist. No case of amnesia is exactly alike, says Dr. Ronald Petersen, a Mayo Clinic neurologist and a member of the American Academy of Neurology. Some forget faces, some forget their native language, some "forget" their entire personality. But each case is caused by a head injury, a neurological disease or, in some cases, years of drug or alcohol abuse. Petersen, who did not treat Philpots, explains that the type of memory loss depends on what region of the brain is impacted; for example, retrograde amnesia generally happens when damage is done to the brain's temporal lobes, and both retrograde and anterograde amnesia, like Philpots has, can happen when the hippocampus is injured. But it's still not understood what makes someone's memory "reset" every 30 seconds or, in Philpots' case, every day. © 2010 msnbc.com
Keyword: Learning & Memory
Link ID: 14372 - Posted: 08.17.2010
By John von Radowitz, Mid-life stress can increase the risk of women developing Alzheimer's disease, a study has shown. Women who reported repeated episodes of stress and anxiety in middle age were up to twice as likely to develop dementia than those who did not, a team of Swedish scientists found. The majority of those affected were diagnosed with Alzheimer's, the most common form of dementia. Researchers followed the progress of 1,415 women between 1968 and 2000. Three surveys in 1968, 1974 and 1980 were carried out to assess levels of psychological stress experienced by the women, who were aged between 38 and 60 at the start of the study. Stress was defined as a "sense of irritation, tension, nervousness, anxiety, fear or sleeping problems" lasting a month or more. During the course of the study, 161 of the women taking part developed dementia, mainly in the form of Alzheimer's disease. Dementia risk was 65% higher in women who suffered frequent stress in middle age. ©independent.co.uk
Keyword: Stress; Alzheimers
Link ID: 14371 - Posted: 08.17.2010
by Bijal Trivedi CLAIRE CHESKIN used to live in a murky world of grey, her damaged eyes only seeing large objects if they were right next to her. She could detect the outlines of people but not their expressions, and could just about make out the silhouettes of buildings, but no details. Looking into the distance? Forget it. Nowadays things are looking distinctly brighter for Cheskin. Using a device called vOICe, which translates visual images into "soundscapes", she has trained her brain to "see through her ears". When travelling, the device helps her identify points of interest; at home she uses it to find things she has put down, like coffee cups. "I've sailed across the English Channel and across the North Sea, sometimes using the vOICe to spot landmarks," she says. "The lights on the land were faint but the vOICe could pick them up." As if the signposting of objects wasn't impressive and useful enough, some long-term users of the device like Cheskin eventually report complete images somewhat akin to normal sight, thanks to a long-term rewiring of their brains. Sometimes these changes are so profound that it alters their perceptions even when they aren't using the device. As such, the vOICe (the "OIC" standing for "Oh, I See") is now proving invaluable as a research tool, providing insights into the brain's mind-boggling capacity for adaptation. The idea of hijacking another sense to replace lost vision has a long history. One of the first "sensory substitution" devices was developed in 1969 by neuroscientist Paul Bach-y-Rita. He rigged up a television camera to a dentist's chair, on which was a 20-by-20 array of stimulators that translated images into tactile signals by vibrating against the participant's back. Despite the crudeness of the set-up, it allowed blind participants to detect the presence of horizontal, vertical and diagonal lines, while skilled users could even associate the physical sensations with faces and common objects. © Copyright Reed Business Information Ltd.
By Tina Hesman Saey Pumping up is easier for people who have been buff before, and now scientists think they know why — muscles retain a memory of their former fitness even as they wither from lack of use. That memory is stored as DNA-containing nuclei, which proliferate when a muscle is exercised. Contrary to previous thinking, those nuclei aren’t lost when muscles atrophy, researchers report online August 16 in the Proceedings of the National Academy of Sciences. The extra nuclei form a type of muscle memory that allows the muscle to bounce back quickly when retrained. The findings suggest that exercise early in life could help fend off frailness in the elderly, and also raise questions about how long doping athletes should be banned from competition, says study leader Kristian Gundersen, a physiologist at the University of Oslo in Norway. Muscle cells are huge, Gundersen says. And because the cells are so big, more than one nucleus is needed to supply the DNA templates for making large amounts of the proteins that give muscle its strength. Previous research has demonstrated that with exercise, muscle cells get even bigger by merging with stem cells called satellite cells, which are nestled between muscle fiber cells. Researchers had previously thought that when muscles atrophy, the extra nuclei are killed by a cell death program called apoptosis. © Society for Science & the Public 2000 - 2010
Keyword: Muscles
Link ID: 14369 - Posted: 08.17.2010
People who are aggressive may be at higher risk for heart attack or stroke, a new study suggests. The study of 5,614 Italians in Sardinia found that those who scored high for antagonistic traits like competitiveness and aggression on a standard personality test had more thickening of their neck arteries compared with those who were more agreeable. The thickness of this carotid artery is considered a risk factor for heart attack and stroke, researchers said in Monday's online issue of the journal Hypertension: Journal of the American Heart Association. "People who tend to be competitive and more willing to fight for their own self-interest have thicker arterial walls, which is a risk factor for cardiovascular disease," Angelina Sutin, the study's lead author and a postdoctoral fellow with the U.S. National Institute on Aging in Baltimore, Md., said in a news release. "Agreeable people tend to be trusting, straightforward and show concern for others while people who score high on antagonism tend to be distrustful, skeptical and at the extreme, cynical, manipulative, self-centered, arrogant and quick to express anger," she added. When researchers followed up with study participants three years after the initial tests, they found they found the link between artery thickening and antagonism had persisted. © CBC 2010
Keyword: Aggression
Link ID: 14368 - Posted: 08.17.2010


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