Tom Simonite A computer system that can rival some doctors' ability to diagnose early-stage Alzheimer's is being trialled in the US. It analyses a person's brain waves as they tackle a number of simple sound-based tests. An estimated 24 million people worldwide suffer the dementia caused by Alzheimer's disease. Early diagnosis is difficult and remains one of the greatest challenges in both patient care and the search for new treatments. The only way to make a definite diagnosis is to find the telltale plaques of protein in a person's brain after death. Prior to this, memory and cognition tests are used to diagnose sufferers. But not everyone gets access to the right expertise and a US study published in 1999 found that community health centres only spot around 75% of Alzheimer's cases, while specialist centres, including large hospitals, are 85% to 90% accurate. Now a team of US researchers have developed a computer system that could help close this gap. Developed by computer engineer Robi Polikar of Rowan University, in New Jersey, neurologist Christopher Clark from the Alzheimer's Disease Center in Pennsylvania and psychologist John Kounios at Drexel University in Philadelphia, the machine shows better accuracy than the average community centre. It uses an electrode cap to monitor a person's brain waves as they take a sound-based test. The person is played a series of low tones, with a much higher "oddball" tone occurring intermittently. When the oddball tone occurs, they must press a button, and their brain's response is also recorded. © Copyright Reed Business Information Lt

Keyword: Alzheimers; Hearing
Link ID: 10184 - Posted: 06.24.2010

Researchers funded by the National Institutes of Health have discovered how a defect in a single master gene disrupts the process by which several genes interact to create myelin, a fatty coating that covers nerve cells and increases the speed and reliability of their electrical signals. The discovery has implications for understanding disorders of myelin production. These disorders can affect the peripheral nervous system — the nerves outside the brain and spine. These disorders are known collectively as peripheral neuropathies. Peripheral neuropathies can result in numbness, weakness, pain, and impaired movement. They include one of the most common genetically inherited disorders, Charcot-Marie-Tooth disease, which causes progressive muscle weakening The myelin sheath that surrounds a nerve cell is analogous to the insulating material that coats an electrical cord or wire, keeping nerve impulses from dissipating, allowing them to travel farther and faster along the length of the nerve cell. The researchers discovered how a defect in just one copy of the gene, known as early growth response gene 2 (EGR2) affects the normal copy of the gene as well as the functioning of other genes, resulting in peripheral neuropathy. “The researchers have deciphered a key sequence essential to the assembly of myelin,” said Duane Alexander, M.D., Director of the NICHD, the NIH institute that funded the study. “Their discovery will provide important insight into the origins of disorders affecting myelin production.”

Keyword: Development of the Brain; Glia
Link ID: 10183 - Posted: 06.24.2010

By JOHN HEILPRIN WASHINGTON -- Companies that make or distribute toys, zippers and other children's products will face tougher government scrutiny to keep out any lead that could poison and kill children or harm their brain development. The Environmental Protection Agency agreed in response to legal pressure to write up to 120 importing and manufacturing companies by the end of the month, instructing them to provide health and safety studies if any lead might be found in the products they make for children. "Parents still need to be vigilant about the recalls on products marketed to children that might contain lead, and take those products away from children as soon as they are recalled," Jessica Frohman, co-chair of the Sierra Club's national toxics committee, said Sunday. The EPA letters are part of a settlement it signed Friday with the Sierra Club and another advocacy group, Improving Kids' Environment. The agency also must tell the Consumer Product Safety Commission "that information EPA has reviewed raises questions about the adequacy of quality control measures by companies importing and/or distributing children's jewelry." Lead, a highly toxic element, can cause severe nerve damage, especially in children. The EPA says lead emissions have dropped more than 90 percent since it was first listed as an air pollutant in 1976, mainly by removing lead from gasoline. Other sources of exposure to it include food and soil, solid waste, coal, oil, iron and steel production, lead smelters and tobacco smoke. © 2007 The Associated Press

Keyword: Neurotoxins; Development of the Brain
Link ID: 10182 - Posted: 06.24.2010

Andy Reynolds Spiders love to fly. Hundreds can touch down in an acre of land on a day when conditions are right. And before casting out a silk thread and swooping miles through the air, a spider checks the weather just as a human pilot might do during a pre-flight routine, a new study finds. Spiders somehow consider tradeoffs between wind speed and sunshine, preferring cloudy fall and spring days as the best flight weather, the researchers discovered. Called ballooning, a spider’s mode of transport involves casting out a “dragline” of silk thread, which gets carried by the wind, along with the attached critter. Since wind is the fuel and sunshine leads to updrafts helpful for take-off, scientists figured sunny, windy days would make for perfect ballooning conditions. But a team of biologists and mathematicians with Rothamsted Research in England calculated travel distances under a range of conditions for wind and sun levels. A resulting computer model revealed the best flight weather, from an arachnid's point of view, indeed corresponds with real-life peaks in spider ballooning on cloudy fall and spring days. While hot summer days will spawn more of the updrafts, the associated lack of breeze would mean they couldn’t drift anywhere once aloft, the scientists think. At the other extreme, for instance during winter storms, whipping winds that become too strong would interfere with the updrafts to make any flight impossible. © 2007 MSNBC.com © 2007 Microsoft

Keyword: Animal Migration
Link ID: 10181 - Posted: 06.24.2010

Jennifer Viegas, Discovery News — Humans pride themselves on their intellectual superiority over other animals. When playing a memory game, however, both humans and rhesus monkeys play equally well or, one might say, equally poorly. Each species appears to possess a three- to four-item short-term memory limit, meaning that both monkeys and humans often have trouble remembering details about this number of items. This is especially true when the game involves comparing this amount of stuff with another amount. The mental limit might even be a universal trait possessed by most all creatures. "It looks like both humans and nonhuman animals use the same type of short-term memory system to represent and count things in their environment, with a strict memory limit of three to four items," lead author Justin Wood told Discovery News. "To me, this is quite counterintuitive," Wood, a researcher in the Cognitive Evolution Laboratory and the Department of Psychology at Harvard University, added. "Our visual experience of the world is very rich, yet we can only retain a very small portion of it once we close our eyes!" Wood and colleagues Marc Hauser, David Glynn and David Barner conducted memory game experiments involving free-ranging rhesus macaques living on the island of Cayo Santiago, Puerto Rico. © 2007 Discovery Communications Inc.

Keyword: Learning & Memory; Evolution
Link ID: 10180 - Posted: 06.24.2010

Susan Milius A group of 35 labs this week unveiled a draft of the genome for the rhesus macaque, the most widely used laboratory primate and a close cousin to people. "The big question here is, 'What makes us human?'" says Richard A. Gibbs of the Baylor College of Medicine in Houston, who led the DNA-sequencing project. The rhesus macaque is the third primate to have its genome described. Scientists reported the detailed human sequence in 2003 (SN: 4/19/03, p. 245: Available to subscribers at http://www.sciencenews.org/articles/20030419/fob6.asp) and a draft of the chimpanzee genome in 2005 (SN: 9/3/05, p. 147: http://www.sciencenews.org/20050903/fob1.asp). With the macaque, human, and chimpanzee sequences now in hand, researchers can triangulate to learn what genes primates share and what genes are uniquely human. "Just seeing differences in chimpanzees and humans, it's been hard to say what's on the chimpanzee side and what's on the human side," says Gibbs. Chimps share 98 percent of their DNA with people. The consortium reports in the April 13 Science that 93 percent of the macaque genome resembles that of people and chimps. Chimps are so genetically close to people that it's been difficult to tell whether a similarity indicates a sequence valuable enough to persist through evolutionary history or just a happenstance of a shared family background. The macaque's extra bit of difference could help scientists make that distinction, says Gibbs. ©2007 Science Service.

Keyword: Genes & Behavior; Evolution
Link ID: 10179 - Posted: 06.24.2010

Retinal implant learns to polish the picture Tom Simonite Software that can be taught to refine the information sent from a bionic eye to its wearer is being trialled in Germany. Retinal implants can restore some vision to blind or partially blind people by taking over the job of turning light into signals transmitted to the brain. So far, about 10 people in Germany and 15 in the US have been fitted with such implants although expanded US trials are planned. "These people report seeing light and dark and maybe some limited fuzzy shapes," says Rolf Eckmiller, a computer scientist at Bonn University in Germany. "But they don't have any gestalt perception." Eckmiller says the secret to improving these implants is to match the signals they produce with the signals that a healthy eye sends to the brain. One team in California, US, is trying to do that by building a copy of the retina's neurons in silicon. Eckmiller, along with colleagues Oliver Baruth and Rolf Schatten, plan to use learning software instead. In their system, a camera feeds information to a "retina encoder" - software that mimics the image processing done by a healthy retina. "It has hundreds of different parameters [that can] be properly tuned," says Eckmiller. "But only one setting is appropriate to allow proper perception." © Copyright Reed Business Information Ltd

Keyword: Vision; Robotics
Link ID: 10178 - Posted: 06.24.2010

Alison Abbott Passively listening to Mozart — or indeed any other music you enjoy — does not make you smarter. But more studies should be done to find out whether music lessons could raise your child's IQ in the long term, concludes a report analysing all the scientific literature on music and intelligence, which was published last week by the German research ministry. The ministry commissioned the report — surprisingly the first to systematically review the literature on the purported intelligence effect of music — from a team of nine German neuroscientists, psychologists, educationalists and philosophers, all music experts. The ministry felt it had to tackle the subject because it had been inundated with requests for funding of studies on music and intelligence, which it didn't know how to assess. The interest in this scientific area was first sparked by the controversial 1993 Nature report1 in which psychologist Frances Rauscher and her colleagues at the University of California, Irvine, claimed that people perform better on spatial tasks — such as recognizing patterns, or folding paper — after listening to Mozart for 10 minutes. The 'Mozart effect' remained a marketing tool for the music industry, and some private schools, long after a torrent of additional studies started to cast doubt on the finding. In the wild commercial flurry, which often involved over-interpretation of available data, the issues of listening to music and actively practicing music were frequently mixed up. ©2007 Nature Publishing Group

Keyword: Intelligence; Hearing
Link ID: 10177 - Posted: 06.24.2010

Gautam Singh A woman prefers a more masculine man when she is fertile and looking for a fling rather than a mate for life, according to a new study. The finding suggests the value that women place on masculinity changes with context and with women’s reproductive cycles and immediate goals. A woman's preference for manly men also was found to vary based on how attractive she rated herself. And some of a woman's sex drive might involve tricks in the brain over which she has no control. Previous research has shown that women view facial masculinity—square jaws and well-defined brow ridges—as good characteristics for short-term partners, while more feminine traits are perceived as better for long-term mates. Another study found that women smell better to men at certain points in their menstrual cycles. In the new study, researchers asked women who were at different points in their menstrual cycles (and who were not on the pill) to rate their own attractiveness. Then researchers presented them with image pairs representing “feminized” and “masculinized” versions of the same male body. The women were asked to choose the body they thought was most attractive for a short-term relationship and then again for a long-term relationship. © 2007 MSNBC.com © 2007 Microsoft

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 10176 - Posted: 06.24.2010

By GARDINER HARRIS GAITHERSBURG, Md., — A panel of federal drug advisers voted 20 to 1 Thursday to reject an application by Merck to sell its pain pill Arcoxia because of concerns that the drug could cause as many as 30,000 heart attacks annually if widely used. Food and Drug Administration officials were unusually harsh in their criticism of the medicine. “What you’re talking about is a potential public health disaster” if Arcoxia is approved for sale, Dr. David Graham, an F.D.A. safety officer, told the panel. Arcoxia is a sister to Vioxx, which Merck withdrew in 2004 after a study showed that it also increased the risks of heart attacks and strokes. Merck sells Arcoxia in 63 countries, and the company underwrote an extensive safety testing program that involved 34,000 arthritis patients. The studies showed that Arcoxia caused nearly three times as many heart attacks, strokes and deaths as naproxen, a popular pain pill sold as Aleve, but was no more effective in curing pain. Patients taking Arcoxia suffered worrisome increases in blood pressure. Dr. Peter Kim, Merck’s research chief, told the panel that the nation’s estimated 21 million arthritis patients needed new therapy options. Representatives of his company who followed him said Arcoxia was no more effective than 20 older pain pills already marketed — some for pennies a pill — and just as risky for the heart than all but one of them. Copyright 2007 The New York Times Company

Keyword: Pain & Touch
Link ID: 10175 - Posted: 06.24.2010

West Virginia University neurosurgeon Vince Miele says it's rare for a boxer to be carried out of the ring on a stretcher. More often, by the time a contender who's suffered an acute brain injury seeks treatment, it's become life threatening. That's what happened to his patient, Jennifer Heater, now 28, who in 2002 went to the emergency room the day after leaving a match with a headache that turned out to be a blood clot in her brain. "The size of her clot could have easily been fatal," says Miele. Heater spent a year in the hospital having multiple brain surgeries. "I was so drugged up and just out of my mind, I cannot recall a lot about being in the hospital other than the neurosurgeons coming in at 4:30 in the morning with the flashlights," says Heater. "But afterwards, being so sick, I couldn't eat, it took me a really long time to eat food just regular food and just to be able to walk, and to get my speech back." Miele, who's served as a ringside physician, says it's not easy to protect athletes without any objective way to know when to stop a match. "Right now it's very subjective. You observe the fighters, you examine them before and after the matches, and that's it, really," he says. "You can't go get a CT scan, an MRI scan, you can't do a formal neuro exam during a match. So everything that we use right now to stop a fight or to protect the fighter is subjective." © ScienCentral, 2000-2007.

Keyword: Brain Injury/Concussion
Link ID: 10174 - Posted: 06.24.2010

Roxanne Khamsi People with a common gene variation have a 70% increased risk of obesity, according to a large new study of Europeans. Half of white Europeans have one defective copy of the gene FTO, which carries a 30% increased risk of obesity, the researchers found. But around 16% hold two altered copies of FTO, which carries a 70% increased obesity risk, the researchers say. They suspect that a similar proportion of other populations also hold the defective copies of FTO. Mark McCarthy at the University of Oxford in the UK and colleagues analysed the DNA in blood samples from 39,000 white people in the UK and Finland. They compared the genetic data with information about the subjects' physical health. Of the participants in the study, about 25% were obese. Individuals with a body-mass-index of 25 or higher are classified as overweight, while those with a BMI of 30 or more are categorised as obese. BMI is measured by dividing a person's weight by the square of their height. McCarthy's team found that small variations in FTO, which sits on chromosome 16, were more common among the obese subjects. People with two altered copies of the gene had a were three kilograms heavier, on average, than those with normal copies. Only 35% of this white European population had two normal copies of the gene. © Copyright Reed Business Information Ltd

Keyword: Obesity; Genes & Behavior
Link ID: 10173 - Posted: 06.24.2010

By Robynne Boyd Sleepwalkers do the strangest things. Many accounts attest to a somnambulist leaving their house clad only in underpants, or rising to cook a meal and returning to bed without so much as tasting it. A stern warning is frequently tacked onto these tales: waking a sleepwalker could kill them. The chances of killing a sleepwalker due to the shock of sudden awakening, however, is about as likely as somebody expiring from a dream about dying. While it is true that waking a sleepwalker, especially forcefully, may distress them, it is an absolutely false statement that someone would die from shock, says Michael Salemi, general manager at the California Center for Sleep Disorders. "You can startle sleepwalkers, and they can be very disoriented when you wake them up and they can have violent, or confused reactions, but I have not heard of a documented case of someone dying from being woken up." Sleepwalking's hazard is more closely linked to what the sleepwalker may encounter when roaming about in a nocturnal reverie. Sleepwalking, or "somnambulism," is part of a larger category of sleep-related disorders known as parasomnias, which include night terrors, REM behavior disorder, restless legs syndrome and sleepwalking. For the majority of people, sleepwalking consists of mundane activities such as sitting up in bed, ambling around the house or dressing and undressing. A minority of sleepwalkers, however, perform more complex behaviors, including preparing meals, having intercourse, climbing through windows and driving cars—all while actually asleep. These episodes can be as brief as a few seconds or can continue for 30 minutes or longer. © 1996-2007 Scientific American, Inc.

Keyword: Sleep
Link ID: 10172 - Posted: 06.24.2010

Peter Aldhous Whether you think of them as mad or bad, they are certainly dangerous to know. All societies contain a few extremely violent individuals, who are either psychopaths or have a related severe personality disorder. With no concern about the harm they inflict, little can be done to change their behaviour, psychiatrists say. Now the UK government is challenging this dogma in the hope of protecting the public from these highly risky people. It has already altered criminal law to allow certain violent offenders to be given indefinite jail sentences. Over the coming weeks, parliament will debate legislation that could broaden the definition of mental disorders and create powers to detain such people for treatment (see "Doctors or jailers...", below). Meanwhile, the government is rolling out an unprecedented treatment and research programme aiming to show it is possible to reduce the risks posed by the most dangerous violent offenders. Just like the changes to the law, the "Dangerous People with Severe Personality Disorder" (DSPD) programme is highly controversial. However, even critics concede that it holds the best chance yet of showing whether violent psychopaths can be reformed - and so psychiatrists worldwide will be watching. © Copyright Reed Business Information Ltd

Keyword: Aggression
Link ID: 10171 - Posted: 06.24.2010

Jennifer Viegas, Discovery News — From Southern drawls to Russian dialects, human language varies widely across regions and cultures. Now scientists have documented similar geographical variations in calls emitted by male bearded seals in the Arctic. The vocalizations of this seal are so different that an individual from Alaska may have trouble understanding a male of the same species from Canada. The discovery adds bearded seals to a growing list of animals, including bottlenose dolphins, bats, prairie dogs, crickets, and many other species, that show regional variations in their calls and acoustic signals. "Some of them, such as killer whales, even have real vocal dialects," lead author Denise Risch told Discovery News. Risch is a researcher at Humboldt University in Berlin and at the Norwegian College of Fisheries Science, University of Tromso. She and her colleagues obtained recordings over several years of male bearded seals from four Arctic sites: Alaska, Svalbard, the western Canadian Arctic and the Canadian High Arctic. © 2007 Discovery Communications Inc.

Keyword: Language; Animal Communication
Link ID: 10170 - Posted: 06.24.2010

Kenyon Wallace, OTTAWA (CP) - Women use more of their brains than men when it comes to driving a car, using a computer mouse or performing other visually guided actions, says a new study that suggests stroke victims should have different rehabilitation programs depending on their gender. The way your brain "fires" in the split second before doing tasks that require eye-hand co-ordination depends on whether you're a man or a woman, says Lauren Sergio, a York University professor and co-author of the study. The study found that for females, areas in both the left and right sides of the brain were active during eye-hand co-ordination experiments. That occurred for men only when they were planning their most complex task: moving a cursor on a screen in the opposite direction to the one expected, using a joystick. "We found that in females, there were three major brain areas involved in visually guided movement and they showed activity on both sides of the brain in most of the exercises in the study," Sergio said in an interview. "In contrast, male brains lit up on both sides only for the most complex exercise." The findings, published in February in the European Journal of Neuroscience, could have implications for the way stroke victims are rehabilitated, said Sergio, a kinesiologist who studies the mechanics of body movements. © 2007 CanWest Interactive

Keyword: Sexual Behavior
Link ID: 10169 - Posted: 06.24.2010

Childhood memories might best be kept in a photo album, not in your mind. Turns out, storing old memories can make you forget an important appointment or what you needed to buy at the store today. Too many long-term memories make it hard to properly filter new information and process short-term memories, according to a study last month in the Proceedings of the National Academy of Sciences. "In our world, we are constantly bombarded by new information so we are constantly filtering, and if we did not do this, we would be overwhelmed," said study team member Gaël Malleret of Columbia University Medical Center. The new research indicates that those with better working memory may have fewer new neurons being developed in their hippocampus — a region of the brain involved in formation of memories. This "helps them forget old and useless information sooner and enables them to take in new information faster,” Malleret said. Researchers previously believed that growth of new neurons in the hippocampus, known as neurogenesis, was beneficial to memory. © 2007 LiveScience.com.

Keyword: Learning & Memory; Neurogenesis
Link ID: 10168 - Posted: 06.24.2010

By Deborah Tannen I once showed my mother a photograph taken of me by a professional photographer. Instead of commenting on the glamorous pose and makeup-artist adornment, she said, "One of your eyes is smaller than the other." Then she turned to me and gripped my chin as she examined my face. "It is," she pronounced. "Your left eye is smaller." For a while after, whenever she saw me, she inspected my eye and reiterated her concern. During that time, I too became preoccupied with my left eye. My mother's perspective had become my own. When else does a slight imperfection -- a pimple, a small asymmetry -- become the most prominent feature on your face? When you're looking in a mirror. A mother who zeroes in on her daughter's appearance -- often on the Big Three: hair, clothes and weight -- is regarding her daughter in the same way that she looks at herself in a mirror. The more I thought about it, the more this seemed to account for some of the best and worst aspects of the mother-daughter relationship: Each tends to see the other as a reflection of herself. It's wonderful when this means caring deeply, being interested in details and truly understanding the other. But it can cause frustration when it means scrutinizing the other for flaws in the same way that you scrutinize yourself. The mirror image is particularly apt during the teenage years. At this age, a girl may spend hours in front of a full-length mirror, scouring her reflection for tiny imperfections that fill her with dread. And it is typically also at this age that she is most critical of her mother. (One woman recalls how her teenage daughter summed it up: "Everything about you is wrong.") The teenage girl is critiquing her mother -- and finding her wanting -- just as she scans her own mirror image for imperfections. © 2007 The Washington Post Company

Keyword: Anorexia & Bulimia
Link ID: 10167 - Posted: 06.24.2010

Dieting is unlikely to lead to long-term weight loss and may put a person's health at risk, a study says. US researchers found people typically lose between 5% and 10% of their weight during the first six months of a diet. But the review of 31 previous studies, by the University of California, said up to two-thirds put more weight on than they had lost within five years. Repeatedly losing and gaining weight is linked to heart disease and stroke, the American Psychologist journal reported. Lead researcher Traci Mann said: "We found that the majority of people regained all the weight, plus more. Diets do not lead to sustained weight loss or health benefits for the majority of people. We concluded most of them would have been better off not going on the diet at all. "Their weight would have been pretty much the same, and their bodies would not suffer the wear and tear of losing weight and gaining it all back." And she added some diet studies relied on participants to report their weight rather than having it measured by an impartial source while others had low follow-up rates which made their results unrepresentative. She said this might make diets seem more effective than they really were as those who gained weight might be less likely to take part in the follow-ups. In one study, 50% of dieters weighed more than 4.99kg (11lbs) over their starting weight five years after the diet. The study did not name any diets in particular, but looked at a broad spectrum of approaches. (C)BBC

Keyword: Obesity
Link ID: 10166 - Posted: 04.10.2007

By NATALIE ANGIER Even in the most sexually liberated and self-satisfied of nations, many people still yearn to burn more, to feel ready for bedding no matter what the clock says and to desire their partner of 23 years as much as they did when their love was brand new. The market is saturated with books on how to revive a flagging libido or spice up monotonous sex, and sex therapists say “lack of desire” is one of the most common complaints they hear from patients, particularly women. And though there may be legitimate sociological or personal underpinnings to that diminished desire — chronic overwork and stress, a hostile workplace, a slovenly or unsupportive spouse — still the age-old search continues for a simple chemical fix, Cupid encapsulated, a thrill in a pill. Since the spectacular success of Viagra and similar drugs, the pharmaceutical industry has been searching for the female equivalent of Viagra — a treatment that would do for women’s most common sexual complaint, lack of desire, what sildenafil did for men’s, erectile dysfunction. Initial trials of Viagra in women proved highly disappointing. True, the drug enhanced engorgement of vaginal tissue, just as it had of the penis, but that extra bit of pelvic swelling did nothing to amplify women’s desire for or enjoyment of sex. Copyright 2007 The New York Times Company

Keyword: Sexual Behavior
Link ID: 10165 - Posted: 06.24.2010