People who cannot sit still for more than a few minutes provide a clue to keeping slim and trim, a US study says. The Mayo Clinic team says some people have a biological need to fidget and, as a result, burn more calories. They used technology embedded in pants to log even the smallest movements of 10 obese and 10 lean volunteers. The team told Science Magazine that the calories people burned in everyday life were more important in determining weight than previously thought. While fidgeters burn off the calories, couch potatoes can pile on the pounds, they said. The technology was based on that used in fighter-jet control panels, and allowed the scientists to monitor body postures and movements every half-second, continuously for 10 days, from the volunteers' undergarments. The study participants were asked to go about their normal daily routines while wearing the undergarments for the first 10 days of the study. The Mayo team entered this data into a computer, along with the subjects' weights. For the second part of their experiment they asked 10 volunteers who were overweight and 10 who were lean to eat special diets. (C)BBC

Keyword: Obesity
Link ID: 6779 - Posted: 01.29.2005

By R. Douglas Fields In the movie thriller Memento, the principal character, Leonard, can remember everything that happened before his head injury on the night his wife was attacked, but anyone he meets or anything he has done since that fateful night simply vanishes. He has lost the ability to convert short-term memory into long-term memory. Leonard is driven to find his wife's killer and avenge her death, but trapped permanently in the present, he must resort to tattooing the clues of his investigation all over his body. That disturbing story was inspired by the real case history of a patient known in the medical literature only as "HM." When HM was nine years old, a head injury in a bicycle accident left him with debilitating epilepsy. To relieve his seizures that could not be controlled in any other way, surgeons removed parts of HM's hippocampus and adjoining brain regions. The operation succeeded in reducing the brain seizures but inadvertently severed the mysterious link between short-term and long-term memory. Information destined for what is known as declarative memory--people, places, events--must pass through the hippocampus before being recorded in the cerebral cortex. Thus, memories from long ago that were already stored in HM's brain remained clear, but all his experiences of the present soon faded into nothing. HM saw his doctor on a monthly basis, but at each visit it was as if the two had never met. © 1996-2005 Scientific American, Inc.

Keyword: Learning & Memory
Link ID: 6778 - Posted: 06.24.2010

Simply placing a cold cap on a baby's head may be enough to protect it from brain damage and possible death. So report researchers today in the first study to demonstrate an effective treatment for oxygen deprivation in newborns. Oxygen deprivation at birth is a serious matter. It can cause learning disabilities, cerebral palsy, or death in 0.1 to 0.2% of otherwise healthy full-term babies. To date, there has been no treatment available for this rare event, which results from abnormalities and complications during delivery. Pediatric and perinatal biologist Peter Gluckman, now at the Liggins Institute in Auckland, New Zealand, and colleagues first began investigating the problem 20 years ago. The team discovered that oxygen-deprived brain cells don't die immediately. The brain produces compounds that stop cell death, but it takes 2-3 days for the cells to accumulate sufficient levels. So the researchers hit on the idea of cooling the brain for 2-3 days to slow down the process of cell death and buy the brain time to heal itself. After testing the idea on sheep fetuses, the researchers developed a cooling cap for newborn babies. Cooled water is pumped through the cap, which lowers the baby's body temperature by 2-3 degrees Celsius for 3 days following birth. Copyright © 2005 by the American Association for the Advancement of Science.

Keyword: Development of the Brain; Apoptosis
Link ID: 6777 - Posted: 06.24.2010

Connecting brains to computers could circumvent disabilities Christen Brownlee At the University of Tübingen in Germany, neurobiologist Andrea Kübler works with a 49-year-old patient whom she identifies only as H.S. Like many of Kübler's patients, H.S. suffers from amyotrophic lateral sclerosis (ALS), a degenerative disease that slowly breaks down the nerve cells necessary for motion. The disease has paralyzed H.S., stripping him of the motor functions that most people take for granted: sitting up, eating, and even breathing. H.S. was diagnosed with ALS 14 years ago, and a permanent ventilator has done his breathing for him since 1993. From then until recently, H.S. could converse with Kübler and his caregivers only by blinking his eyes. Many people paralyzed by a variety of causes—strokes, tumors, or traumatic brain injuries, to name a few examples—communicate rather well by using their remaining, although impoverished, muscle power. For example, French editor Jean-Dominique Bauby, who was paralyzed by a stroke, dictated a 132-page novel (The Diving Bell and the Butterfly, 1997, Knopf) just by blinking his left eye. Similarly, decades after physicist Stephen Hawking was paralyzed by ALS, he continues to give world-renowned lectures by feeding words into a computer program with a flick of his finger. Eventually, H.S.'s paralysis might prevent him from even blinking his eyes to express himself. He'd then be in a state that doctors aptly refer to as "locked-in syndrome." Thousands of paralyzed people worldwide are in that socially closed-off state. Copyright ©2005 Science Service

Keyword: Robotics
Link ID: 6776 - Posted: 06.24.2010

Christen Brownlee While it hasn't yet been caught in the act, a single-celled parasite has been ready for sex for billions of years. A new research finding provides evidence that sexual reproduction started as soon as life forms that have nuclei and organelles within their cells branched off from their structurally simpler ancestors. The parasite Giardia intestinalis is well known for causing a diarrheal disease that animals and people contract after drinking contaminated water. Many researchers consider this species to be one of the most ancient living members of the eukaryote, or true nucleus, lineage. However, unlike most eukaryotes, G. intestinalis and its relatives have been long considered to reproduce only asexually—by division into two identical cells. To determine when reproduction via sperm and eggs originated, John Logsdon of the University of Iowa in Iowa City and his colleagues took a close look at G. intestinalis' mysterious reproductive life. They focused on the hallmark of sexual reproduction known as meiosis, the process that halves the number of an organism's chromosomes to make gametes such as sperm and eggs. Among available data on the G. intestinalis genome, the researchers searched for genes similar to those that control meiosis in other eukaryotes, including plants, animals, and fungi. Copyright ©2005 Science Service.

Keyword: Sexual Behavior; Evolution
Link ID: 6775 - Posted: 06.24.2010

Scientists say they have discovered the exact mechanism behind the death of brain cells following a stroke. The main culprit is an overload of charged calcium particles or ions, they told the journal Cell. As the brain is starved of oxygen by reduced blood flow, events occur that cause dangerously high levels of calcium ions within the brain cells. The Medical Research Council team believes correcting the calcium imbalance could help treat strokes. Scientists have suspected for some time that calcium was the culprit. But research had mainly concentrated on trying to block the entry of calcium ions into dying nerve cells. The latest study suggests that the main problem is actually a fault in the mechanism that removes calcium ions from the nerve cells. Professor Pierluigi Nicotera and colleagues at the MRC's toxicology unit in Leicester looked at what was happening in the brains of rats when these animals suffered a stroke. When the blood flow to the brain was abruptly stopped, as occurs with a stroke, the nerve cells deprived of oxygen released chemicals that they use to communicate with each other. One of these, called glutamate, causes more widespread damage by triggering a flood of calcium ions into the affected and neighbouring nerve cells. (C)BBC

Keyword: Stroke
Link ID: 6774 - Posted: 01.28.2005

By Christina Larson In September, Fox Searchlight, a film studio known for such offbeat sleeper-hits as Thirteen and Bend It Like Beckham, arranged one of the first screenings of its upcoming movie, Kinsey, which stars a tweed-clad Liam Neeson as 1940s sex researcher Alfred Kinsey. Movie previews are often glittering affairs, staged in posh Los Angeles or New York venues, attended by impeccably dressed actors, film critics, and publicists. But the Kinsey screening was different. It was held in a small theater in Washington D.C., and afterwards the guests—a motley crew of bloggers, political reporters, and think-tank denizens—hovered around the director, Bill Condon, lobbing high-minded questions about academic freedoms and rewiring societies. These are not the sort of people, that is, who can ensure a film's financial success. The event didn't make The Washington Post's gossip column the next morning, but its purpose was different: to win articulate friends. Both the studio and the director knew it needed them. Months earlier, conservative activists had launched an onslaught against the film. Radio host Laura Schlessinger and Judith Reisman, author of a book titled Kinsey, Sex, and Fraud, tried to place ads in a Hollywood trade publication alleging Kinsey was a pervert and a pedophile. (Their ads were declined as obscene.) Focus on the Family and Concerned Women for America, two social conservative organizations, later bombarded newspaper film critics with mailers impugning Kinsey's character and research. When Kinsey opened to the public, the Abstinence Clearinghouse, a network for chastity educators, organized foot soldiers to picket theaters and hand out pamphlets titled “Casualties of Kinsey.” The group's director, Leslee Unruh, explained that “Kinsey should be looked upon in the history books as Hitler, as Saddam Hussein.” Copyright © 2003 The Washington Monthly

Keyword: Sexual Behavior
Link ID: 6773 - Posted: 06.24.2010

NEW YORK, NY, – The causes of autism have long remained a mystery, but new research from Columbia University Medical Center has identified, for the first time, how a cellular defect may be involved in the often crippling neurological disorder. The research, which is published in today's issue of Science, examines how a defect in neuroligin genes may contribute to autism. Neuroligins are components of synapses, which connect individual neurons in the brain. The researchers found that the loss of neuroligins perturbs the formation of neuronal connections and results in an imbalance of neuronal function. This imbalance provides an explanation for the neurodevelopmental defects in autistic children. "Understanding the cellular defects that may underlie autism-spectrum disorders represents an important step towards the goal of providing therapies," said Peter Scheiffele, Ph.D., assistant professor of physiology and cellular biophysics at Columbia University Medical Center, and principal investigator on the study. A defect in the neuroligin genes had previously been observed in autistic patients, but its functional significance was not yet understood. Scheiffele's study showed that in rat neurons without any neuroligin, connections between neurons are altered in a way that is strikingly similar to those found in autistic children.

Keyword: Autism
Link ID: 6772 - Posted: 06.24.2010

In the first-ever study combing the entire human genome for genetic determinants of male sexual orientation, a University of Illinois at Chicago researcher has identified several areas that appear to influence whether a man is heterosexual or gay. The study, which is currently available online, will be published in the March issue of the biomedical journal Human Genetics. UIC's Brian Mustanski, working with colleagues at the National Institutes of Health, found stretches of DNA that appeared to be linked to sexual orientation on three different chromosomes in the nucleus of cells of the human male. "There is no one 'gay' gene," said Mustanski, a psychologist in the UIC department of psychiatry and lead author of the study. "Sexual orientation is a complex trait, so it's not surprising that we found several DNA regions involved in its expression." "Our best guess is that multiple genes, potentially interacting with environmental influences, explain differences in sexual orientation." The genomes of 456 men from 146 families with two or more gay brothers were analyzed. While earlier studies had focused solely on the X chromosome, one of the two sex chromosomes, the present study examined all 22 pairs of non-sex chromosomes in addition to the X chromosome. The other sex chromosome, called Y, was not explored because it is not believed to contain many genes.

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 6771 - Posted: 01.28.2005

— A scent exuded by young women as a subconscious sex attractant has been synthesized for post-menopausal women, who are finding it is luring men in droves, the British weekly New Scientist reported. Forty-four women took part in an experiment to see whether the pheromone — an odor received by heterosexual men as a sign of mating availability — worked for females beyond child-bearing age. Half the group added a chemical copy of the pheromone to their perfume, while the other added a lookalike dummy compound. None of the participants knew whether they were getting the real ingredient or the fake. For the next six weeks, the women kept diaries. Among the pheromone users, 41 percent reported they experienced more petting, kissing and affection with partners, compared with 14 percent among the placebo group. Overall, 68 percent of the pheromone groups reported increases in at least four "intimate socio-sexual behaviors," such as sex and formal dates. In the placebo group, only 41 percent reported increases. Copyright © 2005 Discovery Communications Inc.

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 6770 - Posted: 06.24.2010

Genes may be the key factor in determining how active a person naturally is, suggests a new study of "couch potatoes". But the research also suggests health authorities can tackle the growing obesity epidemic by promoting simple activities like standing up and walking. Previous research has shown that casual activities like shopping and even fidgeting can keep people trim. Now, James Levine, a physician at the Mayo Clinic in Rochester, Minnesota, US, and colleagues have investigated what makes people prone to these behaviours, called "non-exercise activity thermogenesis" (NEAT). The team designed undergarments fitted with sensors to study the posture and movements of 20 self-proclaimed "couch potatoes" for 10 days. Half of the participants were lean, while the others were mildly obese. The team found that the obese people sat for about 2.5 hours longer per day than the lean people. That translates to an extra 350 calories for the same daily food intake and could mean that these "extreme" couch potatoes pack on an extra 15 kilograms per year. Levine says the results show "you don't have to join a gym or buy expensive equipment to lose weight - it's available to you right now." © Copyright Reed Business Information Ltd.

Keyword: Obesity
Link ID: 6769 - Posted: 06.24.2010

Roxanne Khamsi Thanks to the rod and cone cells in our eyes, our brains can use light to build images. Recent studies identified a third type of cell that responds to light and dark. Three research groups have now confirmed that melanopsin is the pigment that this cell-type uses, opening possible avenues for treating blind people. In the classic model, mammals have two types of light-detecting cells, called photoreceptors, in the retina at the back of their eye. Rod cells use the rhodopsin pigment to pick up dim light, and cone cells use related pigments to discriminate colour. But three years ago, scientists found a third type of light-sensitive cell. In such cells, a pigment called melanopsin is used to tell night from day. But apparently the visual parts of the brain do not use this information. Instead, these cells communicate with the neurons at the base of the brain that set the daily body cycle. For example, mice without working rods or cones cannot see images. But researchers showed that they can still use a small set of melanopsin-containing cells in the retina to adjust their biological clocks. Exactly how melanopsin worked, however, remained a mystery. ©2005 Nature Publishing Group

Keyword: Vision; Biological Rhythms
Link ID: 6768 - Posted: 06.24.2010

THE secret of an African herb that helps drug addicts and alcoholics kick the habit has been discovered. The finding could lead to safer and more effective medications for treating addiction. Since the 1960s, many addicts have reported that even a single dose of ibogaine, a hallucinogenic alkaloid extracted from the root of an African shrub, helps them kick their habit by reducing their cravings for drugs. And there is hard evidence to back these claims, as well. However, troubling side effects - including heart problems and several deaths - have kept ibogaine from being widely accepted as a medical treatment. Instead, a few researchers have begun searching for ways to deliver ibogaine's benefits without its risks (New Scientist, 26 April 2003, p 34). A few previous studies have suggested that becoming addicted to a substance lowers the production of a nerve growth factor called glial cell-line derived neurotrophic factor, or GDNF. So Dorit Ron's team at the University of California, San Francisco, decided to test whether ibogaine affects GDNF levels in the brain. In rats injected with ibogaine, the researchers found that production of GDNF increased in a region of the brain called the ventral tegmental area. What's more, injecting either ibogaine or GDNF itself directly into this brain area decreased alcohol cravings in addicted rats, whereas injecting anti-GDNF antibodies eliminated any beneficial effect of ibogaine. The results appear in The Journal of Neuroscience. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse
Link ID: 6767 - Posted: 06.24.2010

Blasts of bitter cold air to the face, mountains of snow and sneaky black ice put few people in a sunny mood. But surprisingly, the weather has little affect on people's overall state of mind, according to research that will be published in an upcoming issue of the journal Psychological Science. Three years ago, Matthew Keller, the lead author of the article, found himself in the doldrums of a Michigan winter. He was completing his graduate degree in psychology and spending most of his time working indoors. Any time he was able to escape, Old Man Winter offered a chilling embrace. Finally Keller chased away his winter blues with a trip to Mexico. "When I left Michigan to go to Mexico, I just felt like there was color in life again," he says. When Keller returned that spring, he decided to test how the weather really affects people's mood and cognitive ability. He and his colleagues conducted three separate studies evaluating people's moods, memories and openness to new information. In the first of the three studies, nearly 100 volunteers filled out questionnaires reporting their general mood, the amount of time they spent outside that day, and their general activity level. The study's participants were also asked to perform two cognitive tests. The first tested volunteers' ability to listen to a string of numbers and accurately repeat them, while the second evaluated their willingness to change pre-established opinions after receiving new information regarding an issue or person. In all cases, higher scores indicated better moods and cognitive ability. Keller correlated this survey information with local weather data collected from the National Climatic Data Center. © ScienCentral, 2000- 2005.

Keyword: Depression; Biological Rhythms
Link ID: 6766 - Posted: 06.24.2010

Scientists have discovered how to make cells sensitive to light in what may lead to a new approach to treating certain forms of blindness. The research, published today (January 27) in the science journal Nature, shows that a gene called melanopsin causes nerve cells to become photoreceptive. The team of experts from The University of Manchester and Imperial College London found that activating melanopsin in cells that don't normally use the gene makes them sensitive to light. "The melanopsin made the cells photoreceptive which tells us that this protein is able to absorb light," said Dr Rob Lucas, who led the team in Manchester. "This discovery might provide food for thought for scientists looking for ways of treating visual loss." Dr Lucas, whose research concerns the effect light has on our daily rhythms, said the classical view of how the eye sees is through photoreceptive cells in the retina called rods and cones. But Dr Lucas and Professor Hankins were part of a team that recently discovered a third type of photoreceptor, although the mechanisms of how it worked had not been fully understood – until now. "Over the last few years it has become increasingly accepted that we have a third system that uses melanopsin and has lain undetected during years of vigorous scientific investigation," said Dr Lucas.

Keyword: Vision; Biological Rhythms
Link ID: 6765 - Posted: 06.24.2010

A mystery chemical that young women deploy as a sex attractant pheromone seems to work for post-menopausal women too. Joan Friebely of Harvard University, US, and Susan Rako, a private physician in Newton, Massachusetts, US, have studied 44 post-menopausal women. Half added Athena Pheromone 10:13, originally isolated from a woman's armpit sweat, to their perfume while half added a dummy compound. Neither the women nor the researchers knew who was in each group until the results were in. In diaries kept by the women for six weeks, 41% of pheromone users reported more petting, kissing and affection with partners compared with 14% receiving the placebo. Overall, 68% of pheromone users reported increases in at least one of four "intimate socio-sexual behaviours" such as formal dates and sex, as against 41% on the placebo. But the pheromone's discoverer, biologist Winnifred Cutler, is keeping its identity secret until patents have been granted to Cutler's Athena Institute for Women's Wellness Research in Chester Springs, Pennsylvania, US. "It's still a mystery substance being applied to individuals at unknown concentrations," says George Preti of the Monell Chemical Senses Centre in Philadelphia, Pennsylvania. Friebely and Rako say they have no financial interest in the product. Journal reference: The Journal of Sex Research (vol 41, p 372) © Copyright Reed Business Information Ltd.

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 6764 - Posted: 06.24.2010

BLOOMINGTON, Ind. -- Meeting a friend you haven't seen in years brings on a sudden surge of pleasant memories. You might even call it an avalanche. Recent studies suggest that avalanches in your brain could actually help you to store memories. Last year, scientists at the National Institutes of Health placed slices of rat brain tissue on a microelectrode array and found that the brain cells activated each other in cascades called "neuronal avalanches." New computer models now suggest that these brain avalanches may be optimal for information storage. If so, certain neurochemical treatments might someday improve life for people with memory problems. A report of this work will be published Feb. 4 in the journal Physical Review Letters. "When most people think of an avalanche, they imagine something huge," said biophysicist John Beggs, now a professor in the Biocomplexity Institute at Indiana University Bloomington, who helped perform the NIH experiments. "But avalanches come in all sizes, and the smaller ones are most common. That's just what we found in the brain cells." Copyright 2004, The Trustees of Indiana University

Keyword: Learning & Memory
Link ID: 6763 - Posted: 01.27.2005

By ANDREA LU How the nose knows remains one of the biggest puzzles in science. In an effort to better understand our olfaction, or smell, system, a team of UC Berkeley scientists led by psychology professor Noam Sobel discovered a mechanism in the brain that controls odor detection. “We live in a world in which we’re constantly surrounded by odors. We were trying to find out how it is that we’re not constantly overwhelmed by these odors around us, or how it is that we can tune then out and focus on other things,” said Christina Zelano, biophysics graduate student and lead author of the study. In the study published in December on Nature Neuroscience online, the scientists reported that a region in the primary olfactory cortex of the brain stops an individual from noticing surrounding scents unless the level of odor is high or the person is intentionally trying to smell something. “We ended up identifying a novel brain mechanism that functions as a gate, allowing our brain to focus on what our nose is telling us when we want it to, and more importantly, to tune it out when we’re working on other things,” Zelano said. Zelano says the paper is the first to demonstrate attention in olfaction. “In our study, we found that a frontal sub-region of primary olfactory cortex became more active when subjects were preparing for an olfactory task compared to when they were preparing for an auditory task. This is a very strong demonstration of the fact that sensory processing is an active, rather than a passive process—mammals have evolved to actively seek out the stimuli around them rather than to sit still and have stimuli thrown at them,” Zelano said.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 6762 - Posted: 06.24.2010

By Jennifer Warner -- Despite the famous link between ALS and baseball great Lou Gehrig, a new study shows that there's no medical link between the disease and physical activity. Researchers found no association between increased physical activity and the risk of developing ALS (amyotrophic lateral sclerosis). Those results contradict several previous studies that have shown that slim, athletic individuals may be more likely to develop ALS. ALS is also sometimes called "Lou Gehrig's disease," after the famous baseball player whose career was cut short by the disease, which gradually erodes muscle strength. Although ALS is often very disabling, many people live for years with the disease. The average life expectancy is only two to five years. In the study, researchers compared the amount of physical activity reported by 219 people with ALS with 254 healthy people. All of the participants were asked whether they engaged in sports as youngsters or as an adult or whether they performed extreme physical activity. They reported total physical activity levels as well as activity levels in three different phases of their lives: before age 25, the last 10 years before symptoms of the disease emerged, and one year before the start of the disease. ©1996-2005 WebMD Inc.

Keyword: ALS-Lou Gehrig's Disease
Link ID: 6761 - Posted: 06.24.2010

By WILLIAM GRIMES In the summer of 1849, Walt Whitman walked into an office on Nassau Street in Manhattan to have his head read. Lorenzo Niles Fowler, a phrenologist, palpated 35 areas on both sides of the skull corresponding to emotional or intellectual capacities in the brain. Fowler rated each one on a scale of 1 to 7, with 6 representing the ideal (7 meant dangerous excess). Whitman received a perfect score in nearly every one of Fowler's categories, which bore such fanciful names as "amativeness," "adhesiveness" and "combativeness." Thrilled with his report card, he became an instant convert to phrenology, defined by Ambrose Bierce as "the science of picking a man's pocket through the scalp." Later he donated his magnificent brain to the American Anthropometric Society, which collected it on his death in 1892 and added it to its collection of elite brains. There are quite a few such collections, scattered around the globe, and Brian Burrell visits all of them in his offbeat scientific tour in "Postcards From the Brain Museum." His wanderings take him from the Musée de l'Homme in Paris and the Wistar Institute of Anatomy and Biology in Philadelphia to the impressively stocked Institute of the Brain in Moscow, where the brains of Lenin, Stalin, Eisenstein and Pavlov lie in state, or states, having been sliced into thousands of paper-thin slices and stained for scientific study. Copyright 2005 The New York Times Company

Keyword: Miscellaneous
Link ID: 6760 - Posted: 01.26.2005