By Jeanna Bryner The secret to why male organisms evolve faster than their female counterparts comes down to this: Males are simple creatures. In nearly all species, males seem to ramp up glitzier garbs, more graceful dance moves and more melodic warbles in a never-ending vie to woo the best mates. Called sexual selection, the result is typically a showy male and a plain-Jane female. Evolution speeds along in the males compared to females. The idea that males evolve more quickly than females has been around since 19th century biologist Charles Darwin observed the majesty of a peacock’s tail feather in comparison with those of the drab peahen. How and why males exist in evolutionary overdrive despite carrying essentially the same genes as females has long puzzled scientists. New research on fruit flies, detailed online last week in the journal Proceedings of the National Academy of Sciences, finds males have fewer genetic obstacles to prevent them from responding quickly to selection pressures in their environments. "It’s because males are simpler," said lead author Marta Wayne, a zoologist at the University of Florida in Gainesville. "The mode of inheritance in males involves simpler genetic architecture that does not include as many interactions between genes as could be involved in female inheritance." © 2007 Microsof

Keyword: Sexual Behavior; Evolution
Link ID: 10990 - Posted: 06.24.2010

By JANE E. BRODY There is one undeniable fact about chronic pain: More often than not, it is untreated or undertreated. In a survey last year by the American Pain Society, only 55 percent of all patients with noncancer-related pain and fewer than 40 percent with severe pain said their pain was under control. But it does not have to be this way. There are myriad treatments — drugs, devices and alternative techniques — that can greatly ease persistent pain, if not eliminate it. Chronic pain is second only to respiratory infections as a reason patients seek medical care. Yet because physicians often do not take a patient’s pain seriously or treat it adequately, nearly half of chronic-pain patients have changed doctors at least once, and more than a quarter have changed doctors at least three times. In an ideal world, every such patient would be treated by a pain specialist familiar with the techniques for alleviating pain. But “very few patients with chronic disabling pain have access to a pain specialist,” a team of experts wrote in a supplement to Practical Pain Management in September. As a result, most patients have to rely on primary care physicians for pain treatment, obliging them to learn as much as they can about treatment approaches and to persist in their search for relief. Copyright 2007 The New York Times Company

Keyword: Pain & Touch
Link ID: 10989 - Posted: 06.24.2010

By Carey Goldberg Cut off from their usual social group, the three macaque monkeys fell into simian depression. They no longer took pleasure in anything. They lost status and did not seem to care. more stories like thisColumbia University researchers gave three other exiled monkeys the antidepressant Prozac, and they showed no signs of depression. Later examination showed that in a key area deep in the monkeys' brains - the seahorse-shaped hippocampus - myriad new cells had sprouted. Then the scientists treated four more monkeys with X-ray radiation that blocked the hippocampus from making new cells. When those monkeys were sent into depressing exile, Prozac couldn't help them. And their brains later showed no signs of new cells in the hippocampus. That preliminary study, presented earlier this month at the annual Society for Neuroscience conference, adds the latest scientific backing to a hot theory of depression that has been gaining momentum - and drawing debate - for several years. It goes like this: Depression, which affects at least 19 million Americans a year, can involve problems not only with chemical messengers such as serotonin, but with the very structure of the brain, with the neurons and their connections. © 2007 NY Times Co

Keyword: Depression; Neurogenesis
Link ID: 10988 - Posted: 06.24.2010

By Christopher Shea Security screeners at airports might do a better job spotting weapons if they spent their downtime playing video games - specifically, wasting aliens in lurid first-person shooters like Halo 3. That's just one of the tentative findings emerging from psychologists trying boost the human ability to find threatening objects in X-rayed luggage. The subfield, once tiny and obscure, has bloomed in recent years, spawning competing theories and rival labs - and now provocative suggestions about how airport security screening might be improved. Though baggage screening might seem on the surface like a repetitive and uncomplicated job, it turns out to be devilishly hard. Even well-trained security officers have trouble spotting guns, knives, and plastic explosives amid the tsunami of hair dryers, socks, MP3 players, metal toys, and the occasional cured ham that flows by during a holiday week like this one. A government report issued last week noted that agents were able to sneak fake bombs past security at 19 airports by creating minor distractions, including carrying a roll of coins to set off a metal detector. And a Transportation Security Administration document obtained by USA Today revealed that when investigators placed simulated explosives into bags at Los Angeles International Airport last year, human screeners missed three-quarters of them. © 2007 NY Times Co.

Keyword: Vision
Link ID: 10987 - Posted: 06.24.2010

Initial results from a London pilot scheme where addicts inject themselves with heroin in a clinic suggest it has reduced drug use and crime. Clinics in Brighton and Darlington also form part of the trial. The injecting clinics, intended for hardened heroin addicts for whom conventional treatment has failed, have operated for about two years. The scheme, which has so far cost £2.5m, is funded by both the Home Office and the Department of Health. During the trial, a third of addicts are using heroin substitute methadone orally and a third will inject methadone under supervision. The remaining third, observed by nurses, are injecting themselves with diamorphine - unadulterated heroin - imported from Switzerland and provided by the clinic. Some 150 users will take part in the trial overall. Final results will not be known for another year but, in London, doctors and nursing staff say drug use has fallen significantly. They also say the lives of those on the scheme have stabilised because they are not buying from street dealers and getting involved in crime. Trial leader Professor John Strang, of the National Addiction Centre, based at London's Institute of Psychiatry, told BBC News that about 40% of users had "quit their involvement with the street scene completely". "Of those who have continued, which obviously is a disappointment, it goes down from every day to about four days per month," he added. "Their crimes, for example, have gone from 40 a month to perhaps four crimes per month. The reduction in crime is not perfect but is a great deal better for them and crucially a great deal better for society." People on the trial also attend regular counselling sessions and regular appointments with their GP. BBC correspondent Danny Shaw said initial results suggested the experiment was having a profound effect on hardened heroin addicts. Many were leading much more stable lives and were enjoying better family relationships because they were no longer in and out of prison, our correspondent added. (C)BBC

Keyword: Drug Abuse
Link ID: 10986 - Posted: 11.19.2007

By KATE ZERNIKE Former Justice Sandra Day O’Connor’s husband, suffering from Alzheimer’s disease, has a romance with another woman, and the former justice is thrilled — even visits with the new couple while they hold hands on the porch swing — because it is a relief to see her husband of 55 years so content. What culture tells us about love is generally young love. Songs and movies and literature show us the rapture and the betrayal, the breathlessness and the tears. The O’Connors’ story, reported by the couple’s son in an interview with a television station in Arizona, where Mr. O’Connor lives in an assisted-living center, opened a window onto what might be called, for comparison’s sake, old love. Of course, it illuminated the relationships that often develop among Alzheimer’s patients — new attachments, some call them — and how the desire for intimacy persists even when dementia steals so much else. But in the description of Justice O’Connor’s reaction, the story revealed a poignancy and a richness to love in the later years, providing a rare model at a time when people are living longer, and loving longer. “This is right up there in terms of the cutting-edge ethical and cultural issues of late life love,” said Thomas R. Cole, director of the McGovern Center for Health, Humanities and the Human Spirit at the University of Texas, and author of a cultural history of aging. “We need moral exemplars, not to slavishly imitate, but to help us identify ways of being in love when you’re older.” Copyright 2007 The New York Times Company

Keyword: Alzheimers; Sexual Behavior
Link ID: 10985 - Posted: 06.24.2010

By JON MOOALLEM Pete Bils’s background is in sales — or, as he puts it, “retail concepts.” He joined Select Comfort 12 years ago to teach its salespeople how to better sell the company’s Sleep Number Bed. The Sleep Number Bed is an air-filled mattress. Each side can be inflated with a little remote control to the ideal level of firmness for the person sleeping on it — his or her “sleep number,” zero to 100 — thus accommodating a husband who prefers his side firm and a wife who likes hers softer. You may recognize the Sleep Number Bed from its television commercials featuring the original Bionic Woman, Lindsay Wagner. Or you may have seen Bils himself explicating its many features and benefits in the loneliest hours of the night on the QVC shopping network. Off-camera, Bils spends much of his time reading scientific research. He mingles at medical conferences and is chairman of the company’s “Sleep Advisory Board,” a consortium of doctors. He “sleep tinkers,” coordinating pilot studies in sleep labs to understand how to build the mattress of the future. His goal at Select Comfort is to educate Americans about the science and benefits of healthful sleep, and this, plus his title — senior director of sleep innovation and clinical research — makes him seem deliberately more man-of-science than mattress-salesman. The distinction is less clear-cut when it comes to the man himself. “How’d you sleep last night?” Bils asked, strolling into a conference room to meet me at the company’s headquarters outside Minneapolis one morning last summer. He blared it, the way certain men blare, “Darn glad to meet you.” Copyright 2007 The New York Times Company

Keyword: Sleep
Link ID: 10984 - Posted: 06.24.2010

By STEPHEN J. DUBNER and STEVEN D. LEVITT Deborah Kattler Kupetz is a Los Angeles businesswoman and mother of three who tries to watch her weight. That’s why she recently bought two lifelike plastic models of human body fat from a medical-supply company, a one-pound blob and a five-pound blob, and put them on display in her kitchen. By doing so, Kattler Kupetz wouldn’t seem to have much in common with Han Xin, a legendary Chinese general who lived more than 2,000 years ago. But she does. Upon entering one battle, Han assembled his soldiers with their backs to a river so that retreat was not an option. With no choice but to attack the enemy head-on, Han’s men did just that. This is what economists call a commitment device — a means with which to lock yourself into a course of action that you might not otherwise choose but that produces a desired result. While not as severe as Han’s strategy, Kattler Kupetz’s purchase of those fat blobs was a commitment device, too: every mealtime, they force her to envision what a few extra pounds of fat looks like. It is hard to think of anyone who employs commitment devices as avidly as the overweight American. Perhaps you once bought a yearlong gym membership or had a three-month supply of healthful meals delivered to your doorstep. Maybe you joined friends in a group diet or even taped your refrigerator shut. The popular new weight-loss pill Alli, which partly blocks the body’s absorption of fat, is a commitment device with real consequences: a person who takes Alli and then eats too much fatty food may experience a bout of oily diarrhea. Copyright 2007 The New York Times Company

Keyword: Obesity
Link ID: 10983 - Posted: 06.24.2010

By JIM HOLT Most of us have no doubt that our fellow humans are conscious. We are also pretty sure that many animals have consciousness. Some, like the great ape species, even seem to possess self-consciousness, like us. Others, like dogs and cats and pigs, may lack a sense of self, but they certainly appear to experience inner states of pain and pleasure. About smaller creatures, like mosquitoes, we are not so sure; certainly we have few compunctions about killing them. As for plants, they obviously do not have minds, except in fairy tales. Nor do nonliving things like tables and rocks. All that is common sense. But common sense has not always proved to be such a good guide in understanding the world. And the part of our world that is most recalcitrant to our understanding at the moment is consciousness itself. How could the electrochemical processes in the lump of gray matter that is our brain give rise to — or, even more mysteriously, be — the dazzling technicolor play of consciousness, with its transports of joy, its stabs of anguish and its stretches of mild contentment alternating with boredom? This has been called “the most important problem in the biological sciences” and even “the last frontier of science.” It engrosses the intellectual energies of a worldwide community of brain scientists, psychologists, philosophers, physicists, computer scientists and even, from time to time, the Dalai Lama. Copyright 2007 The New York Times Company

Keyword: Miscellaneous
Link ID: 10982 - Posted: 06.24.2010

LONDON - Patients taking the Sanofi-Aventis anti-obesity drug Acomplia have well over double the risk of depression and anxiety, researchers said, adding to the bad news for a drug already linked to suicidal thoughts. Danish researchers reviewed four studies featuring 4,105 patients and found that people taking 20 milligrams per day of the drug were 2.5 times more likely to discontinue treatment due to depressive disorders and three times more likely to stop because of anxiety than those who received a placebo. The findings published in the Lancet journal follow a U.S. advisory panel decision in June that the drug should not be approved in the world’s largest drugs market because it may increase suicidal thoughts and depression. “Taken together with the recent U.S. Food and Drug Administration finding of increased risk of suicide during treatment with rimonabant, we recommend increased alertness by physicians to these potentially severe psychiatric reactions,” Arne Astrup of the University of Copenhagen and colleagues wrote. A study in the British Medical Journal on Friday also found that people taking anti-obesity drugs — including Acomplia — would only see “modest” weight loss with many remaining significantly obese or overweight. Copyright 2007 Reuters

Keyword: Obesity; Depression
Link ID: 10981 - Posted: 06.24.2010

By Larry Greenemeier The mere thought of being interrogated—by a parent, boss or significant other—is enough to make one's blood pressure rise and pulse and breathing rates race. But contrary to popular belief, these signs of anxiety are not reliable indicators of a person's honesty. Instead, researchers are looking into the brain to separate liars from truth tellers. The act of lying or suppressing the truth triggers activities in the brain that send blood to the prefrontal cortex (located just above the eye sockets), which controls several psychological processes, including the one that takes place when a person crafts a new rather than a known response to something. "Lying is an example of this type of executive response, because it involves withholding a truthful response," says Sean Spence, a professor of general adult psychiatry at the University of Sheffield in England. "When you know the answer to a question, the answer is automatic; but to avoid telling me the true answer requires something more." Spence and colleagues use functional Magnetic Resonance Imaging (fMRI) technology to determine whether someone is fibbing by tracing blood flow to certain areas of the brain, which indicates changes in neuronal activity at the synapses (gaps between the neurons). "If you're using fMRI, the scanner is detecting a change in the magnetic properties in the blood," he says. More specifically, hemoglobin molecules in red blood cells exhibit different magnetic properties depending on the amount of oxygen they contain. The most active brain regions use—and thereby contain—the most oxygen. © 1996-2007 Scientific American Inc.

Keyword: Emotions; Brain imaging
Link ID: 10980 - Posted: 06.24.2010

By Elizabeth Quill Your mother may have warned that you'd get a tummy ache if you scarfed down your food, but for one Australian snake, eating too fast could be deadly. The death adder dines on frogs, but some of them are poisonous. So the snake has learned patience: After striking a particular poisonous frog, it waits for its victim's toxin to degrade before it dines. The finding could help ecologists decipher how one species can outevolve another. The death adder stabs unsuspecting frogs with its fangs, injecting venom to kill its supper. The frogs have fought back, however, evolving various defenses--longer legs for bigger jumps or chemical substances that taste nasty and can kill. Ecologists Ben Phillips and Richard Shine, both of the University of Sydney, Australia, decided to study the snake's general feeding behavior. And when they did, they stumbled upon a strange twist in this evolutionary arms race. The team dropped frogs of various species in the snakes' glass pens and kept a video camera rolling to record the action as the snakes captured their prey. The snakes gobbled up nontoxic frogs right after injecting them with venom, but they took more time with two other species, the researchers report in the December issue of The American Naturalist. The snake waited 10 minutes before munching on the marbled frog, which produces a gluelike substance on its skin when irritated. © 2007 American Association for the Advancement of Science.

Keyword: Neurotoxins
Link ID: 10979 - Posted: 06.24.2010

Brian Vastag Scrutinizing the first days of development in abnormal embryonic stem cells, researchers have uncovered a basic mechanism underlying fragile X syndrome, the most common inherited cause of mental retardation in boys. "It could have important implications for treatment," says W. Ted Brown, cochair of the scientific committee of the National Fragile X Foundation, which helped fund the work. The research also highlights the value of embryonic stem cells for studying genetic diseases, says Yang Xu, a stem cell researcher at the University of California, San Diego. Fragile X syndrome is caused by a mutation in a gene called fmr1. By stopping the gene from making its protein, the mutation leads to learning disabilities, elongated facial features, speech and language difficulties, emotional problems, and other symptoms. In boys, who have only one copy of the X chromosome, a single bad fmr1 gene inherited from either parent induces the disorder. Fragile X syndrome more rarely affects girls, who have two X chromosomes. While researchers have long known that the fragile X mutation shuts down the gene, they were unsure how or at what developmental stage the disruption occurs. To study the shutdown, Nissim Benvenisty and his colleagues at the Hebrew University in Jerusalem created three embryonic stem cell lines carrying the mutation. ©2007 Science Service.

Keyword: Development of the Brain; Genes & Behavior
Link ID: 10978 - Posted: 06.24.2010

Roxanne Khamsi Contrary to what one might expect, the hormone melatonin – which helps regulate sleep cycles in humans and other animals – might actually disrupt memory formation, suggests a study in fish. Zebrafish exposed to melatonin take four times longer to recall a learned behaviour than usual, researchers report. The scientists do not know whether melatonin supplements have a negative impact on memory in people, but they believe more research into this hormone pathway is necessary. They add that a drug that blocks the influence of melatonin improved memory in the zebrafish when given at night. Zebrafish can retain information for days, according to Gregg Roman at the University of Houston, Texas, US. So Roman and his colleagues trained these fish to follow the path of a moving light source beamed through the side of the tank. Fish typically have an instinct to swim away from light – but in this experiment they received a mild shock when they did so. On average, it took the fish about 20 minutes to learn to stick close to the light. More importantly, when they were re-tested a day later, the zebrafish still remembered that they needed to keep close to the light. © Copyright Reed Business Information Ltd.

Keyword: Sleep; Learning & Memory
Link ID: 10977 - Posted: 06.24.2010

Michael Hopkin How are long term memories laid down while we sleep?PunchstockResearch on slumbering rats has shed light on how the brain processes its recent experiences into long-term memories. The experiment suggests that the brain creates such memories by 'playing back' the day's events several times faster than they actually happened. The study, carried out by neuroscientists at the University of Arizona in Tucson, boosts the theory that the brain region responsible for organizing long-term recall, known as the medial prefrontal cortex (mPFC), consolidates memory by playing back events during sleep. It also shows that the brain is quicker at re-running these events than it is at actually performing them. The researchers, led by Bruce McNaughton, trained two rats to run to a series of different locations within an area during 50-minute activity sessions. After the task, they allowed the rats to sleep for up to an hour. During the experiment, the researchers monitored the activity of selected brain cells in the rats' mPFC. While performing the task, the cells showed a characteristic pattern of activity. During the subsequent sleep, the same cells showed the same patterns, but at a higher speed. During sleep, the rats' brain replayed this characteristic activity at roughly six or seven times the original speed, McNaughton and his colleagues report in this week's Science. © 2007 Nature Publishing Group

Keyword: Sleep; Learning & Memory
Link ID: 10976 - Posted: 06.24.2010

Patients taking anti-obesity drugs lose only "modest" amounts of weight, and many remain significantly obese or overweight, research reveals. Fat pills like orlistat reduced weight by less than 5kg (11 pounds) or 5% of total body weight - which guidelines say makes their use unjustified. Experts said the Canadian work in the British Medical Journal shows pills are no substitute for healthy living. Eating less and exercising more is essential, they said. Over a billion people worldwide are overweight or obese, making the anti-obesity drug market big business. An estimated $1.2 billion was spent on anti-obesity drugs worldwide in 2005. The latest work by Professor Raj Padwal and his team at the University of Alberta suggests in many cases these pills achieve little in terms of weight loss. They reviewed the evidence from thirty placebo-controlled trials, involving nearly 20,000 people, where adults took one of three anti-obesity drugs - orlistat, sibutramine or rimonabant - for a year or longer. The National Institute for health and Clinical Excellence recommends stopping the use of anti-obesity drugs if 5% of total body weight is not lost after three months. All of the volunteers in the trials were deemed obese, and weighed an average of 100kg (15.7 stone). Orlistat reduced weight by 2.9kg, sibutramine by 4.2kg and rimonabant by 4.7kg. Patients taking the weight loss pills were significantly more likely to achieve 5%-10% weight loss, compared to those who took a dummy drug, however. But is was unclear whether the weight loss achieved was enough to have big health and survival benefits. (C)BBC

Keyword: Obesity
Link ID: 10975 - Posted: 11.17.2007

By Matt Kaplan Royalty has its privileges, even in the insect world. Queen honey bees can choose the sex of their offspring, a new study shows. Like a sharp stinger, that finding pokes a hole in the notion that queens are merely mindless egg layers and that worker bees have the final say on whether the queen lays eggs that give rise to males or females. Every young queen goes on a mating flight and then stores the sperm she collects from multiple matings for the rest of her life, using it up bit by bit as she lays eggs. Males, called drones, emerge from unfertilized eggs, and females emerge from fertilized ones and become the workers. So if the queen adds sperm to an egg, it will produce a female; if she withholds sperm, the egg will produce a male. That would appear to give the queen control over the sex of her offspring. However, the dogma among entomologists is that workers control the type of eggs the queen lays. The workers build the cavities, known as cells, in which the queen will lay her eggs. A queen will lay an unfertilized egg in a particular cell only if the cell is big enough to accommodate a male larva, which is bigger than a female one. So by controlling how many cells they build of each size, the workers can limit how many male offspring the queen produces. Despite these constraints, the queen can still tip the gender balance of the hive, report Katie Wharton and a team of entomologists at Michigan State University in East Lansing. To prove it, they confined queens inside their hives in specially built cages. © 2007 American Association for the Advancement of Science.

Keyword: Sexual Behavior
Link ID: 10974 - Posted: 06.24.2010

Eric Hand How, exactly, does a bat shoot sonar beams out of its nose? Rolf Müller, a computational physicist at Shandong University in Jinan, China, has combed the caves of Southeast Asia to find out. “We are looking at different species to understand their physical tricks,” says Müller, who models the way that bat noses act like antenna, and how their ears work as dishes to collect sound. The work matters not just to biophysicists who want to understand how animals evolve complex systems, but also to roboticists trying to find new ways of navigating in situations in which light sensors don’t work so well, including at night or underwater. Few biophysical studies of bat noses have been done. One researcher bent back a bat’s noseleaf — the complex structure surrounding its nostrils — to see what would happen; another scientist smeared the delicate structures with petroleum jelly. Both procedures messed up the bats’ navigation. To get a better picture of what’s going on in a bat nose, Müller took X-ray scans of the face of a Rufous horseshoe bat (Rhinolophus rouxii ), compiling scans to build a three-dimensional computer model of the nose cavities. He then shot sound waves of differing frequencies through the modelled nose to see where they resonated, and how they were emitted from the noseleaf. Zhuang, Q. & Müller, R. , Phys. Rev. E 76, 051902 (2007). © 2007 Nature Publishing Group –

Keyword: Hearing
Link ID: 10973 - Posted: 06.24.2010

CBC News New research suggests that the formation of memory may be the result of pairing stimulation in a certain region of the brain with a sensory experience. A team of scientists from the University of California found that by activating the nucleus basalis — a neuron-filled part of the brain believed to modulate the brain's interpretation of sensory information — while playing a particular sound, they could alter the neuronal response to the tones in rats. They said this finding may be a key to understanding memory formation. Previous research has shown that the sensory cortex, the part of the brain responsible for receiving and interpreting information from the senses, has a plastic quality, which allows it to reorganize itself in response to important experiences. "In this way, cortical representations of the sensory environment can incorporate new information about the world, depending on the relevance of value of particular stimuli," the study explained. For their experiment, the researchers played tones of different frequencies in a "pseudo-random" sequence to adult rats. The cortical neurons reacted equally to all the tones. Then, they played a tone repetitively for two to five minutes and electrically stimulated the nucleus basalis. © CBC 2007

Keyword: Learning & Memory
Link ID: 10972 - Posted: 06.24.2010

If you ever had a set of Micronauts — toy robots with removable body parts — you probably had fun swapping their heads, imagining how it would affect their behavior. Scientists supported by the National Institutes of Health have been performing similar experiments on ion channels — pores in our nerve cells — to sort out the channels' key functional parts. In the November 15 issue of Nature, one group of researchers shows that a part of ion channels called the paddle is uniquely transplantable between different channels. Writing in the same issue, another group exploited this property to probe the three-dimensional structure of ion channels on an atomic scale. "The effects of many toxins and therapeutic drugs, as well as some diseases, can be wholly explained by changes in ion channel function," says Story Landis, Ph.D., director of the National Institute of Neurological Disorders and Stroke (NINDS), part of the NIH. "We also know that ion channels are at least a contributing player in epilepsy, chronic pain, Parkinson's disease and other disorders. As we learn more about how channels work, we're able to pursue more approaches to treatment." Ion channels are proteins that control the flow of electrically charged salt particles (ions) across the nerve cell membrane. It's the opening and closing of these channels that enables nerve cells to fire off bursts of electrical activity. A built-in voltmeter, called a voltage sensor, pops the channel open when the nerve cell is ready to fire. The papers in Nature hone in on a part of the voltage sensor called the paddle, named for its shape.

Keyword: Miscellaneous
Link ID: 10971 - Posted: 06.24.2010