Few ailments sound scarier than mad cow disease and its human counterparts. They incubate silently for years, slowly eating the brain away and leaving it full of holes. So it's not surprising that many people want the U.S. Department of Agriculture to test all cattle for the illness, formally called bovine spongiform encephalopathy (BSE). Certainly testing all 35 million cattle slaughtered annually would reopen trade with Japan, which has refused American beef since the discovery of a mad cow in Washington State last December. It might prevent BSE-free countries from dominating the export market. And consumers might simply feel better about their steaks, roasts and burgers. Too bad there's not much science to back up the proposal. Commercial "rapid tests" are not designed to detect the disease reliably in most slaughtered bovines. They work best on those that have lived long enough to build up in their brains a detectable amount of prions, the proteins at the root of BSE. Typically those animals are older than 30 months or have symptoms, such as an inability to stand (called downer cattle). Most U.S. bovines, however, reach slaughter weight before 24 months of age--before the tests can accurately detect incubating BSE. Most European countries recognize those limitations and target cattle 30 months and older. But using current kits on all slaughtered animals, at least 80 percent of which are younger than 30 months, may give misleading assurance about the safety of beef. © 1996-2004 Scientific American, Inc.

Keyword: Prions
Link ID: 5729 - Posted: 06.24.2010

By Larry O'Hanlon — Elephants may be listening with their feet as well as with their ears, say researchers who are studying how well super-low frequency elephant song moves through the ground. For about 20 years it's been known that African elephants sing out and respond to calls so low that they are beyond human hearing. Until now, however, no one was sure if the rumbling calls were also moving through the Earth as seismic waves, possibly helping elephants communicate when there is too much noise above ground. "They are trying to prove the concept is possible," said elephant researcher Katy Payne of the Cornell University Bioacoustics Research Program, referring to a team of Stanford University researchers who have published a paper on seismic elephant infrasound calls in the current issue of Geophysical Research Letters. "We have several experiments going on right now to try to determine whether elephants perceive seismic cues via bone through their toenails and foot bones to their middle ear bones, or through vibration-detecting cells in the bottom of the foot," said Stanford's Caitlin O'Connell-Rodwell, now studying the matter in Namibia. Copyright © 2004 Discovery Communications Inc.

Keyword: Hearing
Link ID: 5728 - Posted: 06.24.2010

Using advanced imaging technology, Carnegie Mellon University scientist Eric Ahrens and co-investigators have conducted the first systematic examination of developmental and sex-associated changes in adolescent and adult mouse brains to reveal fundamental differences in key brain structures, such as those important for emotions, learning, and memory. The results, in press with NeuroImage, show that sex hormones alter the development of certain brain structures during puberty and that these effects persist into adulthood. The findings provide a much truer representation of how circulating hormones affect brain structures than could be derived from human imaging for several reasons, according to Ahrens. The animals studied were nearly genetically identical and reared in the same environment -- factors that cannot be controlled in human studies. And the imaging technology, magnetic resonance microscopy, allows high resolution, 3D imaging in the intact, tiny mouse brain. "The finding that specific brain structures change at puberty under the influence of sex hormones should help scientists understand how levels of sex hormones alter the brain's development," said Ahrens, assistant professor of biological sciences. "Researchers could artificially manipulate sex hormones and then use MRM technology to see how the hormones affect brain structures in animal models."

Keyword: Development of the Brain
Link ID: 5727 - Posted: 06.30.2004

Monkeys and apes who are good at deceiving their peers also have the biggest brains relative to their body size. The finding backs the "Machiavellian intelligence" theory, which suggests the benefits of complex social skills fuelled the evolution of large primate brains. Of all the terrestrial mammals, primates have by far the largest brains relative to their body size, with humans having the largest of all. The enlargement is almost exclusively in the neocortex, which makes up more than 80% of the mass of the human brain. Large brains, despite being energetically costly, benefited primates because they conferred complex cognitive skills. But which skills were the priority - was it clever food-finding strategies that were most valuable, for example, or complex social skills? Earlier studies have hinted that social abilities were the key. And now Richard Byrne and Nadia Corp, psychologists at St Andrews University in the UK, have found more direct evidence for this after studying records of primates deceiving each other for personal gain. © Copyright Reed Business Information Ltd.

Keyword: Evolution; Intelligence
Link ID: 5726 - Posted: 06.24.2010

–Bethesda, MD – Concurrent with the national obesity epidemic has been a rise in the discoveries about how the body controls appetite and food intake. In many of the new findings, research has identified a close relationship between the gastrointestinal endocrine system and the brain in regulating food intake. The relationship is expressed in coordination where circulating hormones convey information about food intake and appetite to brain pathways that control eating. A team of researchers has added to this knowledge through their investigation of cholecystokinin (CCK) and glucagon-like-peptide-1 (GLP-1), two pre-absorptive signals that indicate when the appetite is satisfied (“satiety”). Both peptides are classical gastrointestinal hormones that are released into the circulation in response to meal consumption. Earlier research has documented that these peptides participate in controlling the appetite in healthy volunteers, and also in patients with obesity or Type II diabetes. To further explore potential interactions between these two well-known satiety signals, the research team has examined the effects of CCK-33 and GLP-1 and the hormones’ interaction in the control of food intake and satiety in healthy subjects. The authors of the study, “Interaction between GLP-1 and CCK-33 in Inhibiting Food Intake and Appetite in Men,” are Jean-Pierre Gutzwiller, Lukas Degen, Daniel Matzinger, Sven Prestin, and Christoph Beglinger, all from the University Hospital, Basel, Switzerland. Their research appears in the Articles in PresS section of the American Journal of Physiology –Regulatory, Integrative and Comparative Physiology.

Keyword: Obesity
Link ID: 5725 - Posted: 06.24.2010

Electronic skin could give machines a sophisticated sense of touch. PHILIP BALL Robots are about to get more feeling. An electronic skin as sensitive to touch as our own is being developed by scientists in Japan. "Recognition of tactile information will be very important for future generations of robots," says Takao Someya at the University of Tokyo who developed the skin. A sense of touch would help them to identify objects, carry out delicate tasks and avoid collisions. But while a lot of effort has gone into vision and voice recognition for robots, touch sensitivity is still fairly rudimentary. Our own skin contains a battery of touch receptors that produce nerve signals when pressed. For gentle pressures, the main sensors are tiny bulbs of layered tissue called Meissner's corpuscles. Their behaviour is mimicked in plastics such as polyvinylidene fluoride, which generate an electric field when squeezed and are used to make pressure-sensitive pads for computer keyboards and other touch-triggered devices. © Nature News Service / Macmillan Magazines Ltd 2004

Keyword: Robotics; Pain & Touch
Link ID: 5724 - Posted: 06.24.2010

The risks of passive smoking could be twice as bad as previously feared, the British Medical Journal has reported. Researchers from London's St George's and Royal Free hospitals found passive smoking increased the risk of coronary heart disease by 50-60%. The team, which studied 4,792 men over 20 years, said earlier studies which had found a 25-30% increased risk focused on people living with smokers. They did not take account of exposure at work and other places, it added. Doctors at the British Medical Association conference this week have called for a workplace smoking ban. Previous research has linked passive smoking to increased risk of heart disease and stroke. (C)BBC

Keyword: Drug Abuse
Link ID: 5723 - Posted: 06.30.2004

By Caroline Ryan Botox could be used to treat a sexual condition which prevents women having full intercourse, scientists say. Iranian researchers have used the muscle-relaxing toxin - normally associated with wrinkle treatment - to treat women with vaginismus. The psychosomatic condition causes muscle spasms that prevent penetrative intercourse. Many thousands of UK women are thought to suffer from the condition, but cases are often unreported or undiagnosed. The work was presented to the European Fertility Conference in Berlin. Vaginismus can be triggered by traumatic events such as relationship problems or feelings of guilt about sex. Women with the condition associate sex with pain, which can have a huge impact on their lives and on their relationships with their partners. The aim of doctors treating the condition is to enable women to have pain-free intercourse, allowing them to break the pattern. Botox is made from the botulinum toxin produced by the bacterium which causes botulism food poisoning. (C)BBC

Keyword: Sexual Behavior
Link ID: 5722 - Posted: 06.30.2004

Does stationing themselves in front of the television for hours during the day affect children's ability to sleep? "Sleep experts have known for quite some time that staying up late and watching a lot of TV is one of the ways that people can have trouble falling asleep," says Jeffrey Johnson, professor of psychiatry at Columbia University and research scientist at the New York State Psychiatric Institute. Now, the first long-term study on the association between television viewing and sleep reveals a relationship between extensive TV watching and the development early adulthood sleep problems. Starting in 1975, Johnson's colleagues analyzed data about TV viewing habits from 759 parents and children. Television viewing was put into three categories: less than an hour per day, one to three hours per day, and three or more hours per day. When the study began, the children were six years old; some randomly selected children from the group were interviewed about their viewing habits at ages 14, 16, and 22 years (their mothers were interviewed separately). If parent and child had differing answers, the higher of the two answers was used. Johnson, whose research was published in Archives of Pediatrics and Adolescent Medicine, found that heavy TV viewing was associated with difficulty falling asleep, and waking up in the middle of the night and having trouble getting back to sleep. "Individuals who watched three or more hours of TV per day were about twice as likely as those who watched less than one hour of TV per day to have those two different kinds of sleep difficulties by the time they were young adults," he says. © ScienCentral, 2000- 2004.

Keyword: Sleep
Link ID: 5721 - Posted: 06.24.2010

By ANAHAD O'CONNOR Laurie Coots, a marketing executive who flies to meetings in other countries twice a week, spent years trying to conquer sleepless nights and chronic jet lag. But nothing worked, she says, and every day was a struggle to stay awake. "It was debilitating," said Ms. Coots, 46, who is from Los Angeles. "I couldn't give an effective presentation because I was always shaky and nervous from being amped up on caffeine and stimulants." Then she found modafinil, a small white pill that revs up the central nervous system without the jitteriness of caffeine or the addiction and euphoria of amphetamines. "Without it my life would not be possible," she said. Since 1998, modafinil, made by Cephalon and sold under the brand name Provigil, has quietly altered the lives of millions of people. No one knows exactly how it works, but sales of the drug are skyrocketing. Copyright 2004 The New York Times Company

Keyword: Sleep
Link ID: 5720 - Posted: 06.30.2004

Being called a bird-brain might not be so bad, after all. Canadian researchers have shown that humans just aren't cut out to discern certain pitches like their feathered friends. Testing completed on humans, rats, and three different species of birds shows that the birds--even ones that have been raised in isolation--are better at identifying, classifying, and memorizing absolute pitches than both humans and rats, with humans performing just slightly better than rats. "It's amazing how dissimilar the results of this test are when you compare humans and birds," said Dr. Chris Sturdy, a psychology professor at the University of Alberta. "Humans and rats are weak by any standard, and they're just awful when you compare them to the songbirds." For the study, humans were given monetary rewards when they memorized or recognized the pitches that were played for them, while the birds (zebra finches, white throated sparrows, and budgerigars) and rats were given food rewards. Sturdy said humans actually perform fairly well in tests of relative pitch, which refers to the relationship between two pitch sounds played one right after the other, allowing the listener to use one pitch as a reference for the other. However, when humans try to comprehend absolute pitch, which refers to pitches played alone without any external standard to contrast them with, their ability is "lackluster at best," he said.

Keyword: Hearing
Link ID: 5719 - Posted: 06.30.2004

Young women with a history of depression are twice as likely to have the metabolic syndrome, a cluster of symptoms that raise the risk of heart disease, according to a new study. Men with a similar history do not suffer as frequently from the same symptoms, writes Leslie S. Kinder, Ph.D., of the Veterans' Affairs Puget Sound Health Care System, in the journal Psychosomatic Medicine. "Perhaps the health risks linked to depression are more critical to women," Kinder says. Kinder and colleagues looked at results of a national health survey conducted between 1988 and 1994, covering more than 6,000 men and women ages 17 to 39. Women were more likely than men to have experienced a prior episode of depression, and those women who had had at least one episode were also more likely to suffer from the metabolic syndrome. People with the metabolic syndrome have at least three out of five factors linked to heart disease: high blood pressure; high triglycerides; low HDL (good) cholesterol; high fasting blood sugar; or abdominal obesity. "Depression in women was associated with the number of the metabolic syndrome components present," Kinder says, adding that the association between depression and high blood pressure was especially strong.

Keyword: Depression
Link ID: 5718 - Posted: 06.30.2004

Children who watch a lot of television produce less melatonin, new research suggests - the "sleep hormone" has been linked to timing of puberty. Scientists at the University of Florence in Italy found that when youngsters were deprived of their TV sets, computers and video games, their melatonin production increased by an average 30 per cent. “Girls are reaching puberty much earlier than in the 1950s. One reason is due to their average increase in weight; but another may be due to reduced levels of melatonin,” suggests Roberto Salti, who led the study. “Animal studies have shown that low melatonin levels have an important role in promoting an early onset of puberty.” Salti and colleagues studied 74 children aged between six and 12 years old, who normally watched an average three hours of television in the evening between 2000 and midnight. The youngsters, from the Tuscan town of Cavriglia, were encouraged to watch more TV than usual for a week preceding the study. © Copyright Reed Business Information Ltd.

Keyword: Hormones & Behavior; Development of the Brain
Link ID: 5717 - Posted: 06.24.2010

Rockville, MD ––Dogs' ability to discriminate brightness is about half as good as that of humans, according to a study appearing in Volume 4, Issue 3 in the Journal of Vision. In research conducted by scientists from the Veterinary University of Vienna and the University of Memphis, dogs showed a surprising lack of ability to discriminate between grey cards that varied in brightness, says researcher Ulrike Griebel of the University of Memphis. While a great deal is known about dogs' visual acuity and the cellular components of their eyes, there is a paucity of information about their ability to discriminate brightness, says Griebel. Furthermore, she notes that there is relatively little information on how well other animals discriminate brightness. The researchers tested three police dogs--two Belgian shepherds and a German shepherd. The dogs faced a series of pairs of grey squares, which differed in brightness. The task required the dog to determine how much the one square differed in brightness from the other. The correct choice was rewarded with a food treat. The dogs needed a far greater difference in brightness (known as the Weber fraction) than do humans to discriminate between two squares. For the Belgian shepherds the Weber fraction was 0.27; for the German shepherd it was 0.22. Although the researchers did not test humans in their study, previous studies found that humans need a Weber fraction of 0.14 to be able to discern a brightness difference.

Keyword: Vision; Evolution
Link ID: 5716 - Posted: 06.24.2010

Drug targets female brain to boost sex drive. LAURA NELSON Ever since Viagra worked for men - and didn't for women - researchers have been searching for a drug that turns women on. Now a hormone-like drug may hit the spot, by targeting not the genitals, but the brain. The way Viagra works is simple; it dilates blood vessels, increasing blood flow in the genitals. This purely physical effect seems to be sufficient for most men to perform and enjoy sex. But women are more complicated. "The difference between male and female orgasms is that brain effects are more important in women," says John Stevenson, an endocrinologist at the Royal Brompton and Harefield NHS Trust. In other words, physical arousal doesn't happen without desire. And that can be much harder to trigger. "People may get the sensory input, but they don't think, 'ooh I'm horny'." James Pfaus, Behavioural neurobiologist, Concordia University, Montreal © Nature News Service / Macmillan Magazines Ltd 2004

Keyword: Sexual Behavior
Link ID: 5715 - Posted: 06.24.2010

When an animal touches something, it stimulates a chain of nerve cells running from the body surface to the spinal cord to the brain. This system is capable of recording a huge variety and intensity of sensations. Amazingly, however, it all occurs through the firing -- or lack of firing -- of these neurons. How that firing, in electrical pulses called "action potentials," records sensory information is a mystery that neuroscientists have been slowly figuring out over 50 years. Last week, a team of researchers at the University of Maryland School of Medicine reported in the journal Science that they had taken a large step forward. Lauren M. Jones, a graduate student working with Asaf Keller, studied neurons hard-wired into the whisker follicles of rats. In those animals, whiskers are nearly as important as eyes in perceiving their surroundings. Certain neurons only fire when a whisker is moved in one direction but not in a different one -- a fact known for a long time. What Jones discovered is how that information is encoded in the timing of a cell's firing. © 2004 The Washington Post Company

Keyword: Pain & Touch
Link ID: 5714 - Posted: 06.24.2010

A new charity has pledged to stamp out "quack" interventions for people with autism and similar disorders. The Autism Intervention Research Trust says it will fund studies to see which treatments work and which ones do not. Geoffrey Maddrell, its chairman, said there was no scientific evidence to support some existing treatments. He said the charity would also fund research into new ways of treating autism and related disorders, which affect 500,000 Britons. Mr Maddrell said independent research was needed to help people with the condition. "Hundreds of treatments and other methods of intervention are available but few have been scientifically evaluated and there are still large numbers for whom there is currently no effective help. "In many instances, exaggerated or misleading claims are made for specific approaches. "In the UK, only 8% of autism research activity is currently concerned with intervention and the new research trust has been established to address this vital need". (C)BBC

Keyword: Autism
Link ID: 5713 - Posted: 06.28.2004

By BARRY MEIER Forest Laboratories has said a recently concluded test found that its antidepressant Lexapro did not help depressed children and adolescents, an announcement that comes amid the growing controversy over clinical drug tests. The company's announcement is significant because Lexapro contains essentially the same active ingredient as another Forest antidepressant, Celexa, which is widely prescribed for pediatric use. The company made its announcement late Thursday, when it also released a second statement addressing how it had handled its disclosure of results from two trials of Celexa in depressed children. The New York Times reported Monday that Forest officials had not told a medical journal about a failed unpublished study in 2002 of Celexa use in children and adolescents, before the journal published an article this month about a separate test indicating the drug could help young people. Some of the recent article's authors were Forest employees. Copyright 2004 The New York Times Company

Keyword: Depression; Development of the Brain
Link ID: 5712 - Posted: 06.28.2004

Of all the unsolved mysteries of the human body, it is the brain that most rigidly resists our efforts at understanding it; and that lack of understanding is costing us increasingly dear. Mental illness is reaching epidemic levels. The World Health Organisation claims that mental health problems "are fast becoming the number-one health issue of the 21st century". Clinical depression is the biggest international health threat after heart disease. At the same time, there is a growing dissatisfaction with the drug treatments available. In the UK, the number of prescriptions for antidepressants has more than doubled in 10 years, with 80% of GPs admitting they overprescribe drugs such as Prozac and Seroxat because of the lack of alternative forms of treatment. But though they might not be available on the NHS just yet, alternatives are starting to emerge - and with some promising results. Later this month Dr David Servan-Schreiber, a clinical professor of psychiatry and founding member of Medecins Sans Frontières in the US, will visit Britain to launch his book, Healing Without Freud or Prozac, which has already received an enthusiastic response in Belgium, Switzerland and Canada, where it has sold half a million copies. After a career in conventional medicine, Servan-Schreiber's theory is that exercise can be as effective in treating depression and stress as antidepressants. "It is not that I am against antidepressants," he says. "But there are some natural methods of treatment that have been demonstrated to work for milder forms of depression. It doesn't make any sense to ignore them any longer." Guardian Unlimited © Guardian Newspapers Limited 2004

Keyword: Depression; Schizophrenia
Link ID: 5711 - Posted: 06.24.2010

John Travis Find the kid a sports agent. Researchers studying an unusually muscular tot have found that he has gene mutations similar to ones that produce abnormally brawny cattle and mice. Less-severe variations in the same gene may underlie the success of some athletes, the scientists speculate. The boy's mutations disrupt both copies of the gene encoding a muscle protein called myostatin. Previous studies of the gene in animals had suggested that myostatin restrains muscle growth during development and adult life. But scientists didn't know whether the protein serves the same function in people. The boy's powerhouse physique "says pretty definitively that myostatin plays the same role in humans that it does in mice and cattle," concludes Se-Jin Lee of Johns Hopkins Medical Institutions in Baltimore. If so, he adds, then drugs to block myostatin might have some benefits in people with muscle-wasting diseases. Lee is a member of the international group of investigators who have studied the boy since 1999 and now report their results in the June 24 New England Journal of Medicine (NEJM). Copyright ©2004 Science Service.

Keyword: Muscles; Genes & Behavior
Link ID: 5710 - Posted: 06.24.2010