Scientists are perfecting a test which they hope will confirm mad cow disease (vCJD) in humans. At present doctors test for the presence of abnormal proteins called prions which are thought to cause the disease by killing off brain cells. But this can only be definitively done at post mortem by examining the brain. An Edinburgh University team has found a way to boost prion numbers to confirm a diagnosis. Their work features in the Journal of Pathology. The technique, known as protein misfolding cyclic amplification (PMCA), works by by mimicking and accelerating the replication of prions so they are more easily detected in test samples. It has so far been tested mainly in animal models. But the Edinburgh team has shown for the first time that it is possible to use the technique to amplify the number of vCJD prions in infected human brain tissue extracts by using normal blood cells (platelets) to drive the reaction. The sample is incubated with platelets and exposed to repeated rounds of ultrasound, which break the prions up into more numerous smaller particles. Further research is needed to establish whether the technique can be applied to other tissues, such as blood, that might be used in tests for vCJD. Professor James Ironside, of Edinburgh University's National CJD Surveillance Unit, said the test took too long to carry out to be used to obtain a rapid diagnosis in a blood donation centre. (C)BBC

Keyword: Prions
Link ID: 10460 - Posted: 07.06.2007

By DONALD G. McNEIL Jr. Briefly: Who talks more? Man? Woman? Who Talks More? Conventional wisdom: women use 20,000 words a day, men 7,000. Come cocktail hour, hubby played out. Wife frustrated: 13,000 words to go, no takers. Bad for sex. But wisdom comes from populist 2006 book “The Female Brain.” Data shaky. Skeptics abound. Today, study published Science magazine: 396 subjects wear tiny microphones. Result: whoops. Women emit 16,125 words per day, men 15,669. Statistically, even-steven. But authors admit flaw: all 396 were college students — congenitally loquacious, no jobs, no commutes, no need for aphonic mesmerization by Monday Night Football. Despite flaw, says lead author, Matthias R. Mehl, University of Arizona psychologist, “Our paper puts to rest the idea that the female brain evolved to be talkative and the male brain evolved to be reticent.” But fact slyly not mentioned in Science study: after first printing of “Female Brain,” author, Louann Brizendine, began worrying that 20,000 vs. 7,000 figure was just invented by marriage counselors and removed it. Thirteen printings in 21 languages later, myth clings on anyway. Copyright 2007 The New York Times Company

Keyword: Sexual Behavior; Language
Link ID: 10459 - Posted: 06.24.2010

From The Economist print edition FROM an evolutionary perspective, monogamy looks good for females and bad for males. For mothers, it means devotion as dad is going to be around to help look after the kids. For fathers it is more of a prison sentence, because it restricts a male's ability to inseminate lots of females at relatively low cost. In most circumstances, unless the young are likely to die without paternal support, a male has little incentive to stay with an individual female when he has so many other females to breed with. That, at least, was the conventional wisdom until fairly recently. But modern genetic techniques have shown that in many species females in apparently monogamous relationships often produce families that have more than one father. To explain this, biologists have theorised that these females are mating with males who are genetically superior to their regular mates, thus getting the benefit of parental assistance from a cuckold and good genes from a Lothario. Proving that, though, is a lengthy process. And it is only now that Aurélie Cohas and her colleagues at the University of Lyon, in France, seem to have done so. Their paper in July's edition of the Journal of Animal Ecology shows that for marmots, at least, a bit on the side can help a female's evolutionary chances no end. © The Economist Newspaper Limited 2007

Keyword: Sexual Behavior
Link ID: 10458 - Posted: 06.24.2010

By Constance Holden "Women's tongues are like lambs' tails--they are never still." --Old English saying From old adages to modern pop psychology, the notion that women yak more than men is pervasive. But according to a new study, the biggest to date, the two sexes are in fact pretty much neck and neck. Girls have a jump on boys in verbal fluency early in life, but research is confusing on the subject of whether they actually talk more than boys do as adults. One oft-cited statistic, whose origins are shrouded in the mists of time, has it that the average woman utters 20,000 words a day, compared to only 7000 issuing from the laconic male. But until now, there has been "no large-scale study that systematically has recorded the natural conversations of large groups of people for [an] extended period of time,” says psychologist James Pennebaker of the University of Texas at Austin. To remedy that, Pennebaker, along with Arizona psychologist Matthias Mehl and other colleagues equipped 396 college students--210 of them women--for several days with voice recorders that automatically turned on every 12.5 minutes to record for 30 seconds during their waking hours. All words spoken by the wearer were transcribed, counted, and extrapolated to estimate a daily word count. Pennebaker says the findings, appearing in today's issue of Science, should put the myths to rest: Both men and women averaged roughly 16,000 words a day. And there was no appreciable international difference either, at least in North America. U.S. students had about the same average as a sample of 51 students in Mexico. © 2007 American Association for the Advancement of Science

Keyword: Sexual Behavior; Language
Link ID: 10457 - Posted: 06.24.2010

By Krista Zala Rats given a helping paw are more prone to helping others--even complete strangers. This suggests that the animals' social life may be richer than we thought, according to the researchers whose new study revealed this rodent altruism. Many animals, including rats, demonstrate direct reciprocity--described as "I'll help you if you help me." But generalized reciprocity, in which individuals remember how they were treated in the recent past and apply it to others, including strangers, was thought to be a uniquely human trait, explains behavioral ecologist Claudia Rutte at the University of Lausanne in Switzerland. However, she notes, previous studies haven't specifically looked for generalized reciprocity in other animals. To find out if rats have this capacity, Rutte and Michael Taborsky of the University of Bern in Switzerland trained rats to pull a lever that would deliver an oat flake reward to another rat on the other side of a wire mesh wall in a shared cage. Some of these rats were then put on the receiving side, paired for several days with either other rats trained to be helpful—-three different ones over the span--or with untrained rats that didn't pull the lever and provide food. After several days of living with such generous or not-so-generous neighbors, these test rats were then switched back to the lever side of the cage, paired with a new neighbor rat, and watched to see if they would provide food for it. Rats who had been paired with food-providing neighbors helped their new partner more often than those who had had unhelpful neighbors, the researchers report online this week in Public Library of Science Biology. Rutte's team also found that when a test rat was paired with one of the rats that had earlier provided it with oak flakes, it pulled the food lever even more--showing direct reciprocity. When the cage was empty of any neighbor rat, it barely pulled the food lever at all. © 2007 American Association for the Advancement of Science

Keyword: Emotions; Evolution
Link ID: 10456 - Posted: 06.24.2010

Just as the Bee Gees' disco style sounds antique compared to hip-hop, birdsong can also go out of fashion. Such stylistic changes may help explain how mating barriers arise, eventually leading to new species. Behavioural ecologists have long known that some songbirds develop local dialects, and that individual birds respond more strongly to their own dialect than to a foreign one. Less is known about how, or how quickly, such differences arise. To study how a dialect changes over time, Elizabeth Derryberry, a behavioural ecologist at Duke University in Durham, North Carolina, compared recordings of male white-crowned sparrows' song from 1979 - when the Bee Gees topped the charts - and 2003. The modern song, she found, was slower and lower in pitch. This difference mattered to the birds. When Derryberry played the songs to 10 female and 20 male birds, she found that females solicit more copulations and males showed more aggressive territorial behaviour to the contemporary song than to the older ones - even though the recordings were of equal quality and no bird had ever met any of the recorded individuals (Evolution, DOI: 10.1111/j.1558-5646.2007.00154.x). The result shows that meaningful differences in song styles can arise within just a few years, and thus that mating barriers can be erected quickly, says Derryberry. From issue 2611 of New Scientist magazine, 05 July 2007, page 17 © Copyright Reed Business Information Ltd

Keyword: Language; Animal Communication
Link ID: 10455 - Posted: 06.24.2010

Louis Buckley Orang-utans can solve a brain-teaser that would vex many human minds, researchers have found. Faced with a vertical transparent tube, a quarter filled with water, in which a peanut floats tantalizingly beyond reach, what should you do? Five orang-utans from Leipzig Zoo in Germany all came to the same conclusion. Taking mouthfuls of water from a nearby bottle, they spat into the tube until the peanut floated into reach. The apes' ingenuity amazed the study's leader, Natacha Mendes from the Max Planck Institute for Evolutionary Anthropology in Leipzig. "Before we started we thought this was really complicated," she says. "If you asked someone in an office to solve this problem many people wouldn't be able to give a quick answer, and some probably wouldn't be able to figure it out at all." What made the task especially challenging is that the water was concealed inside a drinker, like a hamster's water bottle, and was some distance from the tube. This suggests that the orang-utans had to think at a more abstract level, says Mendes. "They have to have a mental image of the water in order to solve the problem." The results are reported in Biology Letters1. ©2007 Nature Publishing Group |

Keyword: Intelligence; Evolution
Link ID: 10454 - Posted: 06.24.2010

(AP) Difficulty identifying common smells such as lemon, banana and cinnamon may be the first sign of Alzheimer's disease, according to a study that could lead to scratch-and-sniff tests to determine a person's risk for the progressive brain disorder. Such tests could be important if scientists find ways to slow or stop Alzheimer's and the severe memory loss associated with it. For now, there's no cure for the more than 5 million Americans with the disease. Researchers have long known that microscopic lesions considered the hallmarks of Alzheimer's first appear in a brain region important to the sense of smell. "Strictly on the basis of anatomy, yeah, this makes sense," said Robert Franks, an expert on odor perception and the brain at the University of Cincinnati. Franks was not involved in the new study, appearing in Monday's Archives of General Psychiatry. Other studies have linked loss of smell to Alzheimer's, Franks said, but this is the first to measure healthy people's olfactory powers and follow them for five years, testing along the way for signs of mental decline. In the study, 600 people between the ages of 54 and 100 were asked to identify a dozen familiar smells: onion, lemon, cinnamon, black pepper, chocolate, rose, banana, pineapple, soap, paint thinner, gasoline and smoke. © MMVII, CBS Interactive Inc

Keyword: Alzheimers; Chemical Senses (Smell & Taste)
Link ID: 10453 - Posted: 06.24.2010

Scientists believe they have found a way to dampen down the impact of bad memories in people's brains. A US and Canadian team used a drug called propranolol to target unwanted memories, while leaving others intact. They injected the drug, which is more often used to treat heart patients, while a volunteer was asked to recall a painful memory. The Journal of Psychiatric Research study found that this seemed to disrupt the way the memory was then stored. The researchers, from McGill University, in Montreal, and Harvard University in Boston, hope their work could lead to new treatments for patients with psychiatric disorders, such as post-traumatic stress. However, others have warned the research is still at a very early stage - and expressed concern that it could potentially easily be abused. The researchers treated 19 crash or rape victims for 10 days with a drug, or a placebo. The volunteers were asked to recall their memories of a traumatic event that had happened 10 years earlier. A week later the researchers found that those people who were given a shot of propranolol showed fewer signs of stress such as raised heart rate when recalling their trauma. The researchers believe that memories are initially stored in the brain in a malleable, fluid state before becoming hard-wired into the circuitry. Then, when they are recalled, they once again become fluid - and capable of being altered. They believe propranolol disrupts the biochemical pathways that allow a memory to "harden" after it has been recalled. In a separate study, a New York University team said they had successfully erased a single memory from the brains of rats while leaving the rest of their memory intact. Dr Monica Thompson, a consultant clinical psychologist at London's Traumatic Stress Clinic, stressed that post traumatic stress disorder was a complex condition with many other symptoms other than bad memories. (C)BBC

Keyword: Learning & Memory
Link ID: 10452 - Posted: 07.03.2007

By Joanne Kenen David Thibault grows orchids as a hobby, but the elegant flower on his bedside tray did little to lift his spirits. He stared out the window of his room at George Washington University Hospital, waiting for lab results that could tell him if he had months, weeks or maybe only days to live. A month earlier, in April, Thibault and his wife, Judy Thibault Klevins, had been preparing for a trip to Japan when he felt pain that was different from the pain he had long experienced from Crohn's disease, an inflammatory bowel ailment. It turned out to be small-bowel cancer. If the disease weren't so rare, he now ventured aloud, maybe more research money would have gone into it, maybe he wouldn't be facing death at age 67. Joan Panke, a nurse practitioner, listened intently. The coordinator of GW's Palliative Care Service, Panke and her team ease the pain of those with serious or terminal illness. They walk families like the Thibaults through the difficult work of understanding options, making decisions and, sometimes, trying to find a measure of peace as they say goodbye. About a third of U.S. hospitals now offer some form of palliative care, which adapts aspects of the hospice philosophy without requiring patients to forgo curative care or to have a life expectancy of six months or less. Late last year the American Board of Medical Specialties recognized palliative medicine as a specialized field -- a move that will expand training, said Cameron Muir, a palliative care physician at Capital Hospice, the Washington area's largest hospice organization, and the president of the American Academy of Hospice and Palliative Medicine, based in Glenview, Ill. © 2007 The Washington Post Company

Keyword: Pain & Touch
Link ID: 10451 - Posted: 06.24.2010

By Coco Ballantyne Liquid H2O is the sine qua non of life. Making up about 66 percent of the human body, water runs through the blood, inhabits the cells, and lurks in the spaces between. At every moment water escapes the body through sweat, urination, defecation or exhaled breath, among other routes. Replacing these lost stores is essential but rehydration can be overdone. There is such a thing as a fatal water overdose. Earlier this year, a 28-year-old California woman died after competing in a radio station's on-air water-drinking contest. After downing some six liters of water in three hours in the "Hold Your Wee for a Wii" (Nintendo game console) contest, Jennifer Strange vomited, went home with a splitting headache, and died from so-called water intoxication. There are many other tragic examples of death by water. In 2005 a fraternity hazing at California State University, Chico, left a 21-year-old man dead after he was forced to drink excessive amounts of water between rounds of push-ups in a cold basement. Club-goers taking MDMA ("ecstasy") have died after consuming copious amounts of water trying to rehydrate following long nights of dancing and sweating. Going overboard in attempts to rehydrate is also common among endurance athletes. A 2005 study in the New England Journal of Medicine found that close to one sixth of marathon runners develop some degree of hyponatremia, or dilution of the blood caused by drinking too much water. © 1996-2007 Scientific American, Inc.

Keyword: Miscellaneous
Link ID: 10450 - Posted: 06.24.2010

Some people with schizophrenia who become violent may do so for reasons unrelated to their current illness, according to a new study analyzing data from the Clinical Antipsychotic Trials for Intervention Effectiveness (CATIE). CATIE was funded by the National Institutes of Health’s National Institute of Mental Health (NIMH). The study was published online on June 30, 2007, in the journal Law and Human Behavior. “Most people with schizophrenia are not violent,” said NIMH Director Thomas R. Insel, M.D. “But this study indicates that the likelihood of violence is higher among people with schizophrenia who also have a history of other disorders, namely childhood conduct problems.” Using data from 1,445 CATIE participants, Jeffrey Swanson, Ph.D., of Duke University, and colleagues examined the relationship between childhood antisocial behavior, including conduct disorder symptoms, and adult violence among people with schizophrenia. The overall percentage of participants who committed acts of violence was 19 percent. Those with a history of childhood conduct problems reported violence twice as frequently (28 percent) as those without conduct problems (14 percent). In both groups, violence was more likely among those who were unemployed or underemployed, living with family or in restrictive settings (such as a halfway house or hospital), been recently arrested, or involved with the police. Violence was associated with alcohol and substance abuse in both groups.

Keyword: Schizophrenia
Link ID: 10449 - Posted: 06.24.2010

Louis Buckley Rats that benefit from the charity of others are more likely to help strangers get a free meal, researchers have found. This phenomenon, known as 'generalized reciprocity', has only ever been seen before in humans. A good example, says Michael Taborsky of the University of Bern, Switzerland, is what happens when someone finds money in a phone box. In controlled experiments such people have been shown to be much more likely to help out a stranger in need following their good luck. In humans, such benevolence can be explained by cultural factors as well as by underlying biology, says Taborsky. But if similar behaviour can be found in other animals, he reasons, an evolutionary explanation would be far more likely. To test for this behaviour in animals, Taborsky trained rats to pull a lever that produced food for its partner, but not for itself. Rats who had received a free meal in this way were found to be 20% more likely to help out an unknown partner than rats who had received no such charity1. Taborsky believes this behaviour isn't confined to just rats and humans. "I'm convinced generalized reciprocity will be very widespread and found in many different animal species, as our study suggests that an underlying evolutionary mechanism is responsible." ©2007 Nature Publishing Group

Keyword: Evolution
Link ID: 10448 - Posted: 06.24.2010

By Rob Stein Scientists reported yesterday that they have uncovered a biological switch by which stress can promote obesity, a discovery that could help explain the world's growing weight problem and lead to new ways to melt flab and manipulate fat for cosmetic purposes. In a series of experiments on mice, researchers showed that the neurochemical pathway they identified promotes fat growth in chronically stressed animals that eat the equivalent of a junk-food diet. The international team also showed that blocking those signals can prevent fat accumulation and shrink fat deposits and that stimulating the pathway can strategically create new deposits -- possibly offering new ways to remove fat as well as to mold youthful faces, firmer buttocks and bigger breasts. "It's very exciting," said Zofia Zukowska of Georgetown University's Department of Physiology and Biophysics, who led the research, published online by the journal Nature Medicine. "This could be revolutionary." While cautioning that the safety and effectiveness of the approach remain to be proven in people, other researchers said the findings reveal new clues about the basic biology of fat and why obesity has been increasing so quickly, particularly in Western countries. "There is a lot of uncontrollable stress right now in our societies. There's also a lot of inexpensive high-fat food," said Mary F. Dallman of the University of California at San Francisco, who co-wrote a commentary accompanying the research. "This could help explain the obesity epidemic." © 2007 The Washington Post Company

Keyword: Obesity
Link ID: 10447 - Posted: 06.24.2010

By BENEDICT CAREY AT times, adult life can feel like an extended exercise in escaping high school, a scramble to shed wallflower memories, to show all those snickering swells what happens when a worm grows wings or a spine (or a hedge fund). A study released a little over a week ago, which found that eldest children end up, on average, with slightly higher I.Q.’s than younger siblings, was a reminder that the fight for self-definition starts much earlier than freshman year. Families, whatever the relative intelligence of their members, often treat the firstborn as if he or she were the most academic, and the younger siblings fill in other niches: the wild one, the flirt. These imposed caricatures, in combination with the other labels that accumulate from the sandbox through adolescence, can seem over time like a miserable entourage of identities that can be silenced only with hours of therapy. But there’s another way to see these alternate identities: as challenges that can sharpen psychological skills. In a country where reinvention is considered a birthright, many people seem to treat old identities the way Houdini treated padlocked boxes: something to wriggle free from, before being dragged down. And psychological research suggests that this ability can be a sign of mental resilience, of taking control of your own story rather than being trapped by it. Copyright 2007 The New York Times Company

Keyword: Intelligence
Link ID: 10446 - Posted: 06.24.2010

Rowan Hooper Yawning is not something we usually aim to provoke among our readers, but have a yawn now. Does your brain feel cooler? Do you feel more attentive? According to psychologists Andrew Gallup and Gordon Gallup of the State University of New York at Albany, that is why we yawn: to boost blood flow and chill the brain. Not only that, brain-cooling explains why you can "catch" a yawn, says Gordon Gallup. "We think contagious yawning is triggered by empathic mechanisms which function to maintain group vigilance." In other words, yawn-catching evolved to help raise the attentiveness of the whole group. The pair recruited 44 college students to watch, individually, films of people yawning and recorded the number of contagious yawns each volunteer made. Students were told to inhale and exhale in one of four ways: strictly orally; strictly nasally; orally while wearing a nose plug; or just breathe normally. Fifty per cent of people told to breathe normally or through their mouths yawned while watching other people yawn, while none of those told to breathe through their noses yawned. The researchers also found that subjects who held a cold pack to their forehead did not catch yawns from the film, while those who held a warm or room-temperature pack yawned normally (Evolutionary Psychology, vol 5, p 92). © Copyright Reed Business Information Ltd.

Keyword: Sleep
Link ID: 10445 - Posted: 06.24.2010

Helen Pilcher Female mice make new brain cells when they detect a dominant male's urine, researchers have found. The discovery gives a clue as to how the chemical messages shape their receiver's taste in mates. Urine is rich in the sex pheromones that many animals use to recognize and choose their mates. But how they work is unclear. So Samuel Weiss from the University of Calgary in Alberta, Canada, and his colleagues looked at their effects on the brain. The team housed adult female mice with soiled litter for a week. Animals exposed to urine from dominant males showed around a 25% increase in new neurons in two brain regions. Those exposed to clean bedding, or urine from females or subordinate males showed no such increase. The results, published in Nature Neuroscience1, suggest that pheromones from dominant males stimulate the female brain to make new neurons. Female mice prefer dominant males, but females given a chemical that blocks neuron production became indifferent to status. "Adult neurogenesis may be involved in female mate selection," says Weiss. ©2007 Nature Publishing Group

Keyword: Hormones & Behavior; Neurogenesis
Link ID: 10444 - Posted: 06.24.2010

Proteins which cause mad cow disease may also protect against Alzheimer's disease, UK researchers say. Prions naturally present in the brain appear to prevent the build up of a key protein associated with the condition. In laboratory tests, beta amyloid, the building block of Alzheimer's "plaques", did not accumulate if high levels of the prions were present. The findings could lead to new treatments, the Proceedings of the National Academy of Sciences reported. In variant Creutzfeldt-Jakob disease (vCJD), the human version of mad cow disease, the normal version of the prion protein present in brain cells is corrupted by infectious prions causing it to change shape, resulting in brain damage and death. But little is known about purpose of the normal prion proteins. Due to the similarities between Alzheimer's and diseases such as variant CJD, researchers at the University of Leeds, looked for a link. They found that in cells in the laboratory, high levels of the prions reduced the build-up of beta-amyloid protein, which is found in the brains of people with Alzheimer's disease. In comparison, when the level of the prions was low or absent, beta amyloid formation was found to go back up again, suggesting they have a preventive effect on the development of the condition. The researchers also looked at mice who had been genetically engineered to lack the prion proteins and again found that the harmful beta-amyloid proteins were able to form. (C)BBC

Keyword: Alzheimers; Prions
Link ID: 10443 - Posted: 06.30.2007

By GARDINER HARRIS WASHINGTON, — As states begin to require that drug companies disclose their payments to doctors for lectures and other services, a pattern has emerged: psychiatrists earn more money from drug makers than doctors in any other specialty. How this money may be influencing psychiatrists and other doctors has become one of the most contentious issues in health care. For instance, the more psychiatrists have earned from drug makers, the more they have prescribed a new class of powerful medicines known as atypical antipsychotics to children, for whom the drugs are especially risky and mostly unapproved. Vermont officials disclosed Tuesday that drug company payments to psychiatrists in the state more than doubled last year, to an average of $45,692 each from $20,835 in 2005. Antipsychotic medicines are among the largest expenses for the state’s Medicaid program. Over all last year, drug makers spent $2.25 million on marketing payments, fees and travel expenses to Vermont doctors, hospitals and universities, a 2.3 percent increase over the prior year, the state said. The number most likely represents a small fraction of drug makers’ total marketing expenditures to doctors since it does not include the costs of free drug samples or the salaries of sales representatives and their staff members. According to their income statements, drug makers generally spend twice as much to market drugs as they do to research them. Copyright 2007 The New York Times Company

Keyword: Schizophrenia; Depression
Link ID: 10442 - Posted: 06.24.2010

Bruce Bower Many researchers have asserted that only people will assist strangers without receiving anything in return, sometimes at great personal cost. However, a new study suggests that chimpanzees also belong to the Good Samaritan club, as do children as young as 18 months of age. Without any prospect of immediate benefit, chimps helped both people and other chimps that they didn't know, and the 18-month-olds spontaneously assisted adults they'd never seen before, say psychologist Felix Warneken of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and his colleagues. The roots of human altruism reach back roughly 6 million years to a common ancestor of people and chimps, the researchers propose in the July PLoS Biology. "Learning and experience are involved in altruistic helping, but our claim is that there is a predisposition [in chimps and people] to develop such behavior without explicit training," Warneken says. His team conducted three experiments with adult chimps living on an island sanctuary in Uganda and two experiments with 18-month-old German children. In the chimp version of the first experiment, 36 animals watched one at a time from a barred enclosure as an experimenter in an adjacent room—who had had virtually no prior contacts with the animals—reached through the bars for a stick on the other side. The stick was within reach of only the observing chimp. ©2007 Science Service

Keyword: Evolution; Emotions
Link ID: 10441 - Posted: 06.24.2010