A common question flowing across holiday tables trimmed with turkey this week may be "white meat or dark?" Now scientists have identified the genetic switch that governs the formation of the two types during development. White and dark meat differ in appearance because each is made up of a distinct type of muscle fiber. Dark meat comprises so-called slow twitch muscle fibers, which are specialized for extended exertion, whereas white meat is made up of fast twitch fibers that fuel short, intense bursts of energy. That much has been known for some time. The genetic mechanism underlying the specification of one muscle type versus the other was unclear, however. Philip Ingham of the University of Sheffield and his colleagues studied muscle cells of developing zebrafish and found that a gene dubbed u-boot (ubo ) plays a key role in determining what type of muscle develops by controlling the transcription factor protein known as Blimp-1. © 1996-2003 Scientific American, Inc.

Keyword: Muscles
Link ID: 4726 - Posted: 06.24.2010

First UK case of variant CJD from blood. NICOLA JONES A patient who died from the human form of mad cow disease may have caught the illness from a blood transfusion. Policies governing blood donation may require a rethink as a result. It is not possible to tell whether the patient caught the fatal disease - called variant Creutzfeldt-Jakob disease (vCJD) - from the transfusion or contracted it by eating infected meat. But the incident is the first case of "possible transmission" through transfusion - something that scientists have long known to be a possibility. Britain's Department of Health and the National Blood Service have since contacted 15 other patients who also received blood from donors who later died from vCJD. The patients have been offered counselling. © Nature News Service / Macmillan Magazines Ltd 2003

Keyword: Prions
Link ID: 4725 - Posted: 06.24.2010

Emotions triggered by wailing tots. HELEN R. PILCHER The brains of mums and dads are tuned in to the sound of toddlers' cries, reveals a brain-imaging study. Non-parents, on the other hand, remain largely oblivious. Researchers at the University of Basel, Switzerland, played parents and childless adults recordings of babies' cries and laughter. They measured their brain activity using functional magnetic resonance imaging (fMRI). Parents' brains fired up more in response to sobs than giggles, the researchers found1. The cries activated one brain region in particular, called the amygdala, which is involved in processing emotions. © Nature News Service / Macmillan Magazines Ltd 2003

Keyword: Emotions
Link ID: 4724 - Posted: 06.24.2010

Scientists have found an explanation for those mornings where you put coffee on your cornflakes and the cat in the washing machine. They say it is because of a change in the kind of brainwaves someone produces. But the researchers, who presented their findings to the Physiological Society Conference, said the change could have more serious consequences. They say it may have been a factor in accidents like the Chernobyl disaster. A team from the Medical Research Council's cognitive and brain sciences unit in Cambridge examined brainwaves produced by people as they made mistakes. Volunteers took part in a 10-minute repetitive action test that requires prolonged periods of concentration. (C) BBC

Keyword: Miscellaneous
Link ID: 4723 - Posted: 12.20.2003

A drug used to treat epilepsy can also control debilitating symptoms of multiple sclerosis. Levetiracetam was effective in all 11 patients studied by doctors at Southwestern Medical Center in Dallas, Texas. Research published in the Archives of Neurology showed the drug also reduced nerve pain. Multiple sclerosis (MS) experts said the majority of people with the disease experienced muscle spasms and cramps. Spasms and cramps can be extremely debilitating for those affected, leading to loss of balance, increased risk of falls, pain, fatigue, and walking difficulties. People who have experienced a stroke or spinal-cord injury may also be affected. Drugs currently used to treat spasticity may cause memory problems, weakness and lethargy in some patients. (C) BBC

Keyword: Multiple Sclerosis; Epilepsy
Link ID: 4722 - Posted: 12.20.2003

ANN ARBOR, Mich.----The proportion of American 10th- and 12th-grade students who reported using the drug ecstasy in the prior 12 months has fallen by more than half just since 2001. The usage rate among eighth-graders is down considerably, as well, over the same two-year interval. That is just some of the encouraging news to emerge from the 2003 Monitoring the Future (MTF) survey of nearly 50,000 students in 392 secondary schools across the country. Ecstasy rose rapidly in popularity from 1998 through 2001, but in 2001 the study's investigators detected the beginning of an increase in the proportion of students coming to see ecstasy as a dangerous drug. That perception strengthened further in 2002 as use began to decline, and use dropped more sharply in 2003 as the perceived dangers of ecstasy continued to increase. "We have been saying for several years that use of this newly popular drug was not going to diminish until young people began to perceive its use as dangerous," said Lloyd Johnston, the study's principal investigator. "It now appears that teens are finally getting the word about ecstasy's potential consequences, probably due to extensive media coverage of the issue and concerted efforts by several organizations active in educating young people about the dangers of ecstasy." These organizations include the National Institute on Drug Abuse, the White House Office on National Drug Control Policy, and the Partnership for a Drug-Free America. The latter two organizations launched an anti-ecstasy ad campaign in January 2002.

Keyword: Drug Abuse
Link ID: 4721 - Posted: 12.20.2003

'Tis the season for the fun ritual of decorating Christmas trees for many families. But for bowerbirds, a type of bird native to Australia and New Guinea, decoration is a serious business. Bowerbirds build elaborate structures called bowers to attract potential mates. The bower's primary function is to relate a sense of protection. "A bower makes the female comfortable by making it so that the male cannot jump on top of her and copulate with her against her will," says Gerald Borgia, a biologist at the University of Maryland and an expert on bowerbirds who has been studying them for 24 y ears. Borgia says the bowers have another important function: "The females seem to use the bowers in part of their mate choice process. So males with better built bowers are more attractive to females." As seen on the PBS documentary series NOVA , some bowers are small, and others can reach up to 9 feet tall or 6 feet wide. And bowerbirds use everything at their disposal, both natural and man-made, to decorate their creations. "The kind of natural objects they use include parrot feathers, blueberries, yellow leaves, skins from snakes, skulls from rodents, and those kinds of things," says Borgia. "They also use man-made objects including blue clothespins, and occasionally you find yellow condoms on bowers. They often use spoons, money—with the shiny coins in the middle of the bower and the dull coins toward the outside. They use jewelry—invariably if you go out in the Outback of Australia, the local people will tell you stories about spotted bowerbirds stealing wedding rings and putting them on their bowers, and it's said by many people that that's where they go to look for rings when they lose them." © ScienCentral, 2000-2003.

Keyword: Sexual Behavior; Animal Communication
Link ID: 4720 - Posted: 06.24.2010

First-of-its kind study concludes circulating endogenous hormone profile is more dependent on exercise mode or intensity than exercise volume as measured by caloric expenditure in men (Bethesda, MD) -- There are a number of reasons why, in men, the manipulation of anabolic hormones (such as testosterone) and the anabolic/catabolic hormone ratio (e.g., testosterone/cortisol) might be beneficial. From the perspective of an athlete, an increase in anabolic-androgenic hormones can improve performance by decreasing body fat and increasing lean body mass and muscular strength. Among older men, it may help to replace the decline in testosterone, which can negatively affect body composition and physical function. Studies have shown that endurance-trained men tend to have lower levels of testosterone compared to their sedentary counterparts and that resistance-trained men have higher basal testosterone levels. Studies have also found that both endurance- and resistance-trained males had lower testosterone levels than sedentary control subjects. Thus, while it is known that training status can influence the hormone response to exercise, it is not clear whether the mode of training can affect the hormone response to different modes of exercise. Such information could be useful in designing training regimes that will result in the most favorable ratio of anabolic and catabolic hormones.

Keyword: Hormones & Behavior
Link ID: 4719 - Posted: 12.19.2003

Scientists at Johns Hopkins have discovered the first direct evidence in mammals that a chemical intermediate in the production of fatty acids is a key regulator of appetite, according to a report in a recent issue of the Proceedings of the National Academy of Sciences. Scientists have long known that hunger causes increases in some brain chemicals while lowering others. However, the root cause of hunger's effects -- the initial chemical trigger of appetite -- has been elusive. In experiments with mice, the Johns Hopkins researchers showed that appetite is immediately and directly tied to amounts of a chemical called malonyl-CoA. In hungry mice, malonyl-CoA was almost undetectable in the brain. Once fasting mice were given food, however, amounts of the chemical increased to high levels within two hours. Furthermore, chemically reducing appetite by injecting a compound called C75 into the brain brought levels of malonyl-CoA up to those of mice given food, helping to explain C75's effects.

Keyword: Obesity
Link ID: 4718 - Posted: 12.19.2003

Singing fish sometimes let meek males join a menage a trois David Perlman, Chronicle Science Editor Most Sausalito residents know the humming toadfish, whose loud and incessant underwater droning all summer long keeps angry shore dwellers and houseboat residents awake for nights. The sound -- a perfect A-flat -- was a mystery for years, blamed by some conspiracy theorists in the 1980s on secret experiments by the Army Corps of Engineers lab on the city's waterfront, on the local water treatment plant or even on extraterrestrials. Then, a San Francisco marine biologist recognized it as the annoying sound that he'd heard as a graduate student studying fish and trying to sleep on the beach in Baja California: It was the sex call of a species known as the plainfin midshipman. ©2003 San Francisco Chronicle | Feedback | FAQ

Keyword: Sexual Behavior; Animal Communication
Link ID: 4717 - Posted: 06.24.2010

NewScientist.com news service A British man has died from variant CJD after receiving a blood transfusion seven years earlier from a donor who also later died from the disease. The UK secretary of state for health announced the case in an emergency statement to parliament on Wednesday. The case may be the first in the world where the human form of BSE - mad cow disease - has been transmitted via a blood transfusion. But John Reid told the House of Commons: "This is a possibility not a proven causal connection." Both individuals might have acquired the devastating illness separately by eating BSE-infected meat, he says, but "the possibility of this being transfusion-related cannot be discounted". © Copyright Reed Business Information Ltd.

Keyword: Prions
Link ID: 4716 - Posted: 06.24.2010

By Larry O'Hanlon, Discovery News — The bills and brains of duck-billed platypuses are specially equipped with electro-sensors to home in on the electrical signals of prey in muddy night-time stream bottoms, say Australian biologists. A row of nerves in platypus bills, wired to the touch and electro-sensing part of the platypus brain, work like a short-range radar system to pick up the electrical signals of fish, shrimp, crayfish and other invisible food in the murky platypus feeding grounds. The sensory system is just one more remarkable asset for the egg-laying, aquatic Australian mammal. Copyright © 2003 Discovery Communications Inc.

Keyword: Pain & Touch
Link ID: 4715 - Posted: 06.24.2010

Carvings show early Europeans' prodigious skill. MICHAEL HOPKIN A set of ivory figurines found in southwestern Germany add to a growing cache of the oldest art known. The 30,000-year-old carvings underline the remarkable creativity of our earliest European ancestors. Nicholas Conard of the University of Tübingen, Germany, discovered the 2-centimetre-high figures in the Hohle Fels Cave in the country's Swabia region1. The figurines, and similar relics previously unearthed in Swabia, are the earliest known representations of living forms. "Without question, they are the oldest corpus of figurative art in the world," says archaeologist Anthony Sinclair of the University of Liverpool, UK. © Nature News Service / Macmillan Magazines Ltd 2003

Keyword: Evolution
Link ID: 4714 - Posted: 06.24.2010

Stroke experts have issued a warning about the dangers of binge drinking linked to the Christmas party season. The Stroke Association says women are particularly at risk if they drink large amounts of alcohol. Men who drink more than five units of alcohol - half a bottle of wine or two and a half pints of beer - have double the normal stroke risk. The Stroke Association's Margaret Goose said: "By getting too 'merry' people are risking their lives." Small amounts of alcohol - one or two units a day - actually appear to reduce the risk of stroke caused by blood clots blocking the arteries supplying the brain - the cause of the majority of strokes. However, even small amounts of alcohol may increase the smaller risk of a stroke caused by a rupture of a blood vessel. (C) BBC

Keyword: Stroke; Drug Abuse
Link ID: 4713 - Posted: 12.17.2003

By DAVID F. MUSTO In the 1860's a new drug-delivery system, the hypodermic syringe, was perfected. An injection of a small amount of morphine was found to produce the same effect as a larger dose by mouth. Physicians assumed, therefore, that hypodermic injections offered more protection against addiction. Patients with chronic but not life-threatening pain, say osteoarthritis, were provided with morphine and a syringe and told to inject themselves when there was pain. It took some years to appreciate the mistake, but the sad outcome was that the hypodermic syringe not only did not protect from addiction, but it also facilitated it. By 1920 the president of the American Medical Association, Dr. Alexander Lambert of Cornell, somberly stated that "nearly 80 percent of the morphine addicts have acquired the habit from legitimate medication" provided by physicians. During the 1920's the fear of prescribing addictive medicine permeated American medical practice. Pain medication had to be doled out with great care and parsimony. Inadequate pain relief characterized the life of some cancer sufferers as well as postoperative patients. In the 1960's a movement to bring adequate pain relief attracted both researchers and practitioners. Copyright 2003 The New York Times Company

Keyword: Pain & Touch; Drug Abuse
Link ID: 4712 - Posted: 12.17.2003

We humans are proud of our big noggins. The average human skull, which packs some 1350 cubic centimeters (cc) of brainpower, is larger than that of any other animal, relative to body size. Now a molecular biologist suggests that a recently identified gene called ASPM might be implicated in the impressive expansion hominid brains have undergone over the last 2 million years. The work builds on studies of a rare disease called autosomal recessive primary microcephaly (MCPH). In this inherited malady, the brain is typically just 400 cc--roughly the same size as that of the early hominid Australopithecus africanus, of which "Lucy" is the best-known specimen. A earlier report concluded that the most common cause is a mutated ASPM gene (ScienceNOW, 23 September 2002). Jianzhi Zhang of the University of Michigan, Ann Arbor, hypothesized that ASPM might have played a key role in human brain expansion. To test this hypothesis, he looked for evidence that the gene was under "positive selection," meaning that it had provided an evolutionary advantage to hominids. Zhang compared the DNA nucleotide sequence of the human version of ASPM to that of two of our great ape cousins, the chimpanzee and the orangutan, as well to more distantly related animals such as rhesus monkeys, seals, dogs, and hamsters. A gene is considered to have undergone positive selection when it has a relatively high ratio of nucleotide changes that lead to a change in the amino acid sequence of the corresponding protein, compared to changes that make no difference. This ratio was quite high in humans but much lower in chimpanzees and orangutans, Zhang reports in the December issue of Genetics. Copyright © 2003 by the American Association for the Advancement of Science.

Keyword: Genes & Behavior; Evolution
Link ID: 4711 - Posted: 06.24.2010

How you react to stress influences how easily you resist or succumb to disease, including viruses like HIV, discovered UCLA AIDS Institute scientists. Reported in the Dec.15 edition of Biological Psychiatry, the new findings identify the immune mechanism that makes shy people more susceptible to infection than outgoing people. "Since ancient Greece, physicians have noticed that persons with a 'melancholic temperament' are more vulnerable to viral infections," said Steve Cole, principal investigator and assistant professor of hematology-oncology at the David Geffen School of Medicine and a member of the UCLA AIDS Institute. "During the AIDS epidemic, researchers found that introverted people got sick and died sooner than extroverted people," said Bruce Naliboff, co-author and a clinical professor at the UCLA Neuropsychiatric Institute and Veterans Affairs Greater Los Angeles Healthcare System. "Our study pinpoints the biological mechanism that connects personality and disease."

Keyword: Neuroimmunology
Link ID: 4710 - Posted: 12.17.2003

By Ellen Barry, Globe Staff, The way Ernest Hemingway had a drinking problem and Fyodor Dostoevsky had a gambling problem, Dr. Alice Flaherty, a Harvard neurologist, had a writing problem. During a severe bout of postpartum depression three years ago, she wrote so compulsively that the sight of a blank computer screen gave her a narcotic rush. Worried about damaging her family, Flaherty started taking a psychiatric drug to calm her mood swings -- and found that, although ideas still churned in her brain, she was no longer able to put them on paper. It was an excruciating case of writer's block. Thus begins her exploration of "hypergraphia" -- a term used by doctors to describe the overwhelming desire to write -- and its agonizing opposite. In her new book, "The Midnight Disease: The Drive to Write, Writer's Block and the Creative Brain," Flaherty lays out all that neurology has discovered about the artist's brain, from the strange profusion of literary giants with temporal lobe epilepsy to the composer Dmitry Shostakovich's certainty that musical notes radiated from a piece of shrapnel lodged in his brain. The drive to create, Flaherty concludes, is not the same thing as literary talent -- and doctors sometimes ignore it when they are prescribing medications. For her part, Flaherty chose to protect her drive, abnormal though it may be. As she finished the last page of her manuscript, she noted that it was 5:30 a.m., and she had been writing for so long that her legs had become numb. © Copyright 2003 Globe Newspaper Company.

Keyword: Miscellaneous
Link ID: 4709 - Posted: 06.24.2010

Study: Researchers say a communication system high in the nose increases the contrast in odors. By Jonathan Bor, Sun Staff When molecules of freshly ground coffee waft into your nose through a kitchen full of aromas, what makes you notice the coffee? And what, to the trained nose, suggests gourmet rather than canned, espresso rather than regular? Though the complete answer might be years off, smell researchers at the University of Maryland School of Medicine say they've found an important clue: a communications system high in the nose that heightens the contrast between odors so the brain can make better sense of them. Nerve bundles that capture particular scents relay their information to the brain, but not before negotiating with each other to decide what odors should be turned up and down, they said. The system evolved not simply to enhance our appreciation of aromas but, on the most basic level, to help animals survive in the wild. Copyright © 2003, The Baltimore Sun | Get home delivery

Keyword: Chemical Senses (Smell & Taste)
Link ID: 4708 - Posted: 06.24.2010

By REBECCA M. MILZOFF, Crimson Staff Writer The zebrafish looks like any other run of the mill aquarium-inhabitant—a small, glittery swimmer suited to the fishbowl world of a childhood pet. But to Gund Professor of Neuroscience John E. Dowling, this fish represents a living window into the complex interactions between vision and the brain. As Dowling and his laboratory researchers have discovered, study of retinal activity and development in zebrafish provides clues to the connection between what we see and how we act. “I’ve long been interested in the visual system,” Dowling says. He has always used the retina as a model for research in the brain, in part due to the variety of cells involved in retinal actions. Aside from photoreceptors, five other types of neurons in the retina connect with the brain to help start the process of visual imaging. Copyright © 2003, The Harvard Crimson Inc.

Keyword: Vision
Link ID: 4707 - Posted: 06.24.2010