By Daniel Strain Fire ants know how to survive when the waters rise: They turn their bodies into life rafts. A new study explores the physics that keeps fire ant lifeboats, waterborne colonies sometimes containing tens of thousands of bugs, afloat. Linked together, the ants can form a watertight seal that keeps them from drowning, engineers from the Georgia Institute of Technology in Atlanta report the week of April 25 in the Proceedings of the National Academy of Sciences. And the whole is bigger than the sum of its parts, says Julia Parrish, a zoologist at the University of Washington in Seattle: "The properties the group displays are not necessarily predictable by just looking at one individual." Fire ants (Solenopsis invicta), an invasive species around much of the globe, are well-prepared for disaster. When their Brazilian homes flood, entire colonies — including queens, workers and workers carrying larvae — take to the sea. "They have to stay together as a colony to survive," says study coauthor Nathan Mlot of Georgia Tech. Their double-decked rafts — about half the ants float on the bottom holding the rest up — can bob along for days or even weeks. The ants' seafaring success comes down to both small and big properties. On the small scale, single ants can walk on water, at least to a degree, similar to a floating pin or a water-striding insect. When wet, fire ants can also capture tiny air bubbles, probably thanks to the thin layers of hair covering their bodies, giving these intrepid mariners added buoyancy. © Society for Science & the Public 2000 - 2011

Keyword: Miscellaneous
Link ID: 15264 - Posted: 04.26.2011

By Sandra G. Boodman, During the 11 years Sonja MacDonald and her family lived with her spells, they had planned what to do when she sensed — or they observed — one coming on. If she was driving, MacDonald was to pull over to the side of the road; her husband had taught their young children how to take the wheel if she was unable to steer, something that luckily never happened. When she took a shower, someone was always in the bathroom, in case she suddenly passed out. And if it happened in the nursing home where she worked, MacDonald gambled on being able to make it to an empty bed. Over the years doctors had given the Milton, Pa., resident various diagnoses for the episodes, which she said began with an aura — an odd feeling of disorientation sometimes tinged with fear. She would stare blankly, sometimes grasping at unseen objects or briefly losing consciousness. These incidents, which lasted two minutes at most, occurred without warning, leaving her feeling tired and cold but with no memory of what had just happened. Most specialists agreed that the spells were seizures that sometimes follow a migraine headache. But how, MacDonald wondered, could she have migraine seizures when the occasional headaches she had were not severe? Doctors brushed that question aside, and MacDonald resigned herself to living with whatever was wrong. “I told my husband, ‘I will not go back to another doctor. I guess when I drop over someone will believe me,’ ” said MacDonald, now 39. In 2009, a new neurologist took a fresh look at her case and in short order figured out what was wrong. The answer, this doctor subsequently learned, had been buried in MacDonald’s records for years.

Keyword: Epilepsy; Pain & Touch
Link ID: 15263 - Posted: 04.26.2011

by Carl Zimmer One day not long ago a 27-year-old woman was brought to the 
Tel Aviv Sourasky Medical Center, sleepy and confused. Fani Andelman, a neuropsychologist at the center, and colleagues gave the woman a battery of psychological tests to judge her state of mind. At first the woman seemed fine. She could see and speak clearly. She could understand the meaning of words and recall the faces of famous people. She could even solve logic puzzles, including a complex test that required her to plan several steps ahead. But her memory had holes. She could still remember recent events outside her own life, and she could tell Andelman details of her life up to 2004. Beyond that point, however, her autobiography was in tatters. The more doctors probed her so-called episodic memory—the sequential recollection of personal events from the past—the more upset she became. As for envisioning her personal future, that was a lost cause. Asked 
what she thought she might be doing anytime beyond the next day, she couldn’t tell them anything at all. The patient, Andelman realized, hadn’t just lost her past; she had lost her future as well. It was impossible for her to imagine traveling forward in time. During her examination, the woman offered an explanation for her absence of foresight. “I barely know where I am,” she said. “I don’t picture myself in the future. I don’t know what I’ll do when I get home. You need a base to build the future.” The past and future may seem like different worlds, yet the two are intimately intertwined in our minds. In recent studies on mental time travel, neuroscientists found that we use many of the same regions of the brain to remember the past as we do to envision our future lives. In fact, our need for foresight may explain why we can form memories in the first place. They are indeed “a base to build the future.” And together, our senses of past and future may be crucial to our species’ success. © 2011, Kalmbach Publishing Co.

Keyword: Learning & Memory
Link ID: 15262 - Posted: 04.26.2011

By Daryl Shorter, MD and Thomas R. Kosten, MD Substance use disorders (SUD) are recognized worldwide as causes of negative medical, psychological, and social outcomes, and they result in significant personal consequences for affected persons, their families, and society at large. Treatment of SUD has focused on a combination of pharmacotherapy and behavioral therapies in an effort to improve patients’ chances of successfully entering and maintaining recovery. Antidrug vaccines are a potentially important class of medications currently under investigation. They represent yet another frontier in the ongoing quest for novel pharmacological strategies that could be easily integrated into treatment plans to reduce substance use and establish abstinence. Ultimately, these vaccines reflect an important shift in our conceptualization of drugs of abuse, ie, that these substances are “foreign” and that the body’s own defenses can be used against them. Drugs of abuse act centrally on the reward and reinforcement pathways of the brain. After introduction into the body, via oral, intranasal, inhalation, or intravenous route, these substances rapidly enter the brain to activate target neurotransmitter systems. One factor of particular importance in addiction pharmacology relates to the size of the molecule, because substances of abuse must be small enough to traverse the blood-brain barrier. Once in the brain, the initial common pathway of the addictive process is through stimulation of dopamine(Drug information on dopamine) release from the ventral tegmental area to the nucleus accumbens; this, in part, determines the addictive liability of a substance. © 1996 - 2011 UBM Medica LLC,

Keyword: Drug Abuse
Link ID: 15261 - Posted: 04.25.2011

By JOHN ELIGON Drunken recollections, especially in rape trials, rarely play well to jurors. In a society that can be quick to turn a skeptical eye toward women who say they were raped — she was scantily dressed, she’s promiscuous, she’s just angry at him — prosecutors of sex crimes say one of their biggest obstacles in the courtroom is alcohol. A rape trial in Manhattan is the latest example. The accuser, who completed her testimony Monday, admitted that she was so drunk on the night in question that she could not remember most of what happened, even the cab ride home. Yet she provided a vivid description of the moment she said she was raped by the police officer who escorted her up to her apartment. Can someone be that drunk, yet remember specific details of an event? According to scientists, it’s possible. But it is also possible that any memory of a drunken episode is colored by suggestion or outside information. When drunk, people sometimes pass out; they become unconscious. Or they could black out — a condition in which they’re conscious but not storing memories. Blackouts tend to start at blood alcohol levels of at least 0.15 percent, about twice the legal limit for driving, especially when a person hits that level quickly. When alcohol floods the hippocampus — a brain region that records our lives as they unfold — neurons stop talking to each other and capturing memories, said Aaron White, a researcher with the National Institute on Alcohol Abuse and Alcoholism. When the hippocampus is off, no matter how hard one tries, a memory will not be recalled because it will not have been recorded in the first place, Dr. White said. © 2011 The New York Times Company

Keyword: Learning & Memory; Drug Abuse
Link ID: 15260 - Posted: 04.25.2011

By Robert Martone People may advise you to listen to your gut instincts: now research suggests that your gut may have more impact on your thoughts than you ever realized. Scientists from the Karolinska Institute in Sweden and the Genome Institute of Singapore led by Sven Pettersson recently reported in the Proceedings of the National Academy of Sciences that normal gut flora, the bacteria that inhabit our intestines, have a significant impact on brain development and subsequent adult behavior. We human beings may think of ourselves as a highly evolved species of conscious individuals, but we are all far less human than most of us appreciate. Scientists have long recognized that the bacterial cells inhabiting our skin and gut outnumber human cells by ten-to-one. Indeed, Princeton University scientist Bonnie Bassler compared the approximately 30,000 human genes found in the average human to the more than 3 million bacterial genes inhabiting us, concluding that we are at most one percent human. We are only beginning to understand the sort of impact our bacterial passengers have on our daily lives. Moreover, these bacteria have been implicated in the development of neurological and behavioral disorders. For example, gut bacteria may have an influence on the body’s use of vitamin B6, which in turn has profound effects on the health of nerve and muscle cells. They modulate immune tolerance and, because of this, they may have an influence on autoimmune diseases, such as multiple sclerosis. They have been shown to influence anxiety-related behavior, although there is controversy regarding whether gut bacteria exacerbate or ameliorate stress related anxiety responses. In autism and other pervasive developmental disorders, there are reports that the specific bacterial species present in the gut are altered and that gastrointestinal problems exacerbate behavioral symptoms. A newly developed biochemical test for autism is based, in part, upon the end products of bacterial metabolism. © 2011 Scientific American,

Keyword: Autism; Obesity
Link ID: 15259 - Posted: 04.25.2011

By James Gallagher Babies who cry excessively and have problems feeding and sleeping have a greater risk of serious behavioural problems later in life, say scientists. One in five babies has symptoms that could lead to conditions such as ADHD, according to research published in Archives of Disease in Childhood. The review of previous studies looked at nearly 17,000 children. A child-health expert said it would be wrong for parents to be "overly alarmed" by the results. Crying in babies is normal, but some cry "excessively" after the age of three months for reasons other than colic. An international group of researchers looked at this as well as problems eating and sleeping. By comparing data from 22 studies from 1987 to 2006, they found a link between these issues and problems later in life. There was an increased risk of ADHD (Attention Deficit Hyperactivity Disorder), anxiety and depression as well as aggressive behaviour. BBC © 2011

Keyword: ADHD; Development of the Brain
Link ID: 15258 - Posted: 04.23.2011

By Steve Mirsky All seemed well that morning when the rains came. I was warm and dry and didn’t need to leave the comfort of home. But that comfort swiftly departed. First, I heard the glug glug glug. Then I picked up a whiff both faint and foul. Something was entering the bathroom that should only exit the bathroom—raw sewage was reversing its natural course and fighting its way back into my house. The whiffs got stronger. Human waste includes some fascinating and fragrant organic compounds. Take skatole. (Please.) Skatole bears a heavy responsibility for making poo smell phooey. But remember the axiom: it’s the dose that makes the poison. Because in low concentrations, according to Wikipedia, skatole “has a flowery smell and is found in several flowers and essential oils,” such as orange blossoms and jasmine. It is even used—again, in very small amounts—in perfumes. Think about that when dabbing behind the ears. And Wikipedia notes that cigarette manufacturers add skatole as (drum roll) a flavoring ingredient. Just another reason to stop smoking. In addition, waste contains various stinky sulfur compounds, collectively called thiols or mercaptans. They are not your friends. When sewage is backing up into one’s home, the to-do list instantly becomes an un-doo list with only one item: get the plumbers to come immediately. Upon their swift arrival, they unsealed the trap to gain access to the line, which also sent the incoming waste fluid into the subbasement—still bad, but a big improvement. They then sent a camera down the line to examine the problem, performing their version of the closely related diagnostic technique of colonoscopy. © 2011 Scientific American,

Keyword: Chemical Senses (Smell & Taste)
Link ID: 15257 - Posted: 04.23.2011

By Bruce Bower Eat your heart out, Houdini. Average schmoes can make a gorilla-suited dude pounding his chest go poof, thanks in part to a common difficulty with focusing on distractions. People who don’t see unexpected happenings, such as a gorilla strolling by, while concentrating on a task often have difficulty with what amounts to mental multitasking, says a team led by psychology graduate student Janelle Seegmiller of the University of Utah in Salt Lake City. Individuals who do poorly on a test requiring them to perform two mental operations at once are especially prone to an experimental effect dubbed “the invisible gorilla,” Seegmiller and her colleagues report in the May Journal of Experimental Psychology: Learning, Memory and Cognition. Previous studies of this effect have instructed participants to count the number of times people in a video pass a basketball to one another. Nearly half of volunteers don’t notice a person in a gorilla suit walk among the players, pause for a few chest thumps and depart. Why people counting passes sometimes overlook a wandering ape is poorly understood. Explaining this effect is no laughing matter, though, since it corresponds to real-life attention mishaps, such as drivers gabbing on cell phones who fail to see pedestrians in crosswalks or red lights at intersections. “Some people may have enough extra flexibility in their attention to notice distractions while talking on a cell phone behind the wheel, or while counting basketball passes,” says Utah psychologist and study coauthor Jason Watson. © Society for Science & the Public 2000 - 2011

Keyword: Attention; ADHD
Link ID: 15256 - Posted: 04.23.2011

By Joshua Rothman What is morality? For millennia, the problem has bedeviled philosophers, who have debated whether it’s divinely inspired, instinctual, or an abstract set of rules that we should figure out rationally. Patricia Churchland, a philosopher at the University of California San Diego, thinks it’s time for a different kind of answer: Understanding morality, she argues, means understanding its roots in the brain. Churchland, a former MacArthur “genius” fellow, has built a career trying to knit together neuroscience and philosophy, two fields that usually prefer competition to cooperation. In her new book, “Braintrust: What Neuroscience Tells Us about Morality,” Churchland aims to combine the explanatory power of science with the caution and clarity of philosophy. She starts by explaining what’s most clearly known about how morality works in the brain. We know, she argues, that human moral behavior is rooted in the brain’s “circuitry for caring”—ancient biological circuitry that we share with other mammals. (When wolves care about their offspring, what happens in their brains and bodies is remarkably similar to what happens in ours.) Most mammals care only about themselves and their children. In human beings, though, the circle of caring extends widely, even to strangers. These broad circles of caring are the foundations, Churchland says, for morality. They create the tensions that are the essence of moral life. Tension is inevitable, because caring broadly raises challenging, practical problems: All those competing moral obligations need to be balanced out. Churchland argues that we solve those problems the same way we solve other practical problems: sometimes instinctually, but also by drawing on our learning, reasoning, and culture. In the end, her picture of morality recalls Hume’s, or even Aristotle’s: Aristotle, she writes, knew that morality had its roots in human nature, but he also recognized moral problems as “difficult, practical problems emerging from living a social life.” In this conception, morality is rooted in our instincts, but it isn’t entirely instinctual. © 2011 NY Times Co.

Keyword: Emotions
Link ID: 15255 - Posted: 04.23.2011

By Laura Sanders Scratching relieves an itch, sneezing clears out the nose and drinking relieves thirst. And yawning … does something. Researchers have been trying to finish that sentence for centuries. This involuntary, obvious and sometimes contagious behavior afflicts most humans — even those still in the womb — multiple times a day. Yawning isn’t even restricted to people: Snakes, ostriches, hedgehogs and fish have been spotted throwing their mouths open for a satisfying yawn. Yet for a behavior so commonplace, the yawn is still a big, gaping mystery. “Every single day, every person on the planet yawns,” says behavioral biologist Andrew Gallup of Princeton University. “Yet we have no idea why it is we do it.” Actually, people have lots of ideas; the problem is that nobody has proposed one that everybody can agree with. New laboratory experiments are only fueling the debate, supporting some theories and contradicting others. A full-fledged yawn is not restricted to the mouth. Carefully orchestrated pandiculations follow a routine: Lips part, the tongue hunkers down, and muscles in the face, mouth and diaphragm engage as the head tilts back. Air streams in. As the yawn reaches its peak, airflow halts briefly, eyes close, and muscles go rigid as they stretch. The long, slow exhale allows muscles to return to their normal positions. Many researchers are convinced that this complex series of movements, which takes about six seconds on average, must somehow affect the body. © Society for Science & the Public 2000 - 2011

Keyword: Emotions; Evolution
Link ID: 15254 - Posted: 04.23.2011

by Elizabeth Finkel Obesity is on the rise in nations across the globe, and more than diet and genetics may be to blame. A new study suggests a third factor is at work: DNA-binding molecules that can be passed down from mother to child in the womb. The finding could explain why what a woman eats while pregnant can sometimes influence the weight of her child—even into adulthood. Scientists first began to suspect that a mother’s diet could affect the weight of her offspring in 1976. Studying the Dutch famine of 1945, when the German army cut off food supplies to western Holland, researchers found that people born to mothers who were pregnant during the famine were more likely to be obese as adults. Rat studies at the University of Auckland in New Zealand bolstered the findings: mothers who were undernourished during pregnancy gave rise to obese adults. One possible explanation is that the moms are somehow programming their children to live in a food-scarce world by increasing their appetites and ability to store fat—and if the children grow up with plenty to eat, they become overweight. In the past few years, researchers have begun to suspect that so-called epigenetic modifications are behind this programming. Often these are chemical tags called methyl groups that can bind to DNA, where they act a bit like a volume knob, turning up or down the activity of certain genes. In a 2005 study at the University of Auckland, for example, researchers found that they could prevent obesity in rats born to starved mothers by removing methyl tags from their DNA. A recent survey of methyl groups on the DNA of adult people has also suggested that these tags are linked to obesity. But in that study, the authors could not determine whether the epigenetic changes were a consequence of being overweight or the cause of the obesity in the first place. © 2010 American Association for the Advancement of Science.

Keyword: Obesity; Development of the Brain
Link ID: 15253 - Posted: 04.23.2011

Dan Goleman "Keep Your Thumbs Still When I'm Talking to You" read a recent headline in the Sunday Styles section of the New York Times. The rudeness of texting during a conversation is but one of the new don'ts emerging in the unfolding universe of webequette, the new rules for social life on the web. But while such pointers may smooth over some trouble spots, they do nothing about the fundamental collision between the ways we connect digitally, and the connections our brain was designed to crave. Nature designed the brain for face-to-face interactions -- not the online world. A new field, social neuroscience, has discovered that large zones of the brain's frontal areas are dedicated to tuning in to the person we're with, picking up their emotions, movement, even intentions, and coordinating what we do with all that. We have what amounts to a neural WiFi which makes a brain-to-brain bridge while we interact, that operates instantly, unconsciously and powerfully to keep it all going smoothly. More important, when we feel rapport, or come away from a conversation with a friend glowing from a good talk, this is the circuitry that makes us feel that glow. So what's the problem? The online universe, from Facebook and Twitter to texting to email, has no channel for this vital brain-to-brain flow. All that dialogue seems, well, thin, compared to the richness of actually being with the other person. For the social brain, hundreds of contacts online in a day pale in comparison to a hug. © 2011 TheHuffingtonPost.com, Inc.

Keyword: Emotions
Link ID: 15252 - Posted: 04.23.2011

By John Roach Lefties were as outnumbered 600,000 years ago as they are today, according to telltale markings on teeth found on Neanderthal and Neanderthal ancestors in Europe. The finding serves as a new technique to determine whether a person was left- or right-handed from limited skeletal remains, and it also suggests that a key piece for the origin of language was in place at least half a million years ago, David Frayer, an anthropologist at the University of Kansas, told me today. But while ancient righties appeared to outnumber lefties nine to one, the findings don't reveal whether some of the ancient lefties dominated in sports, as baseball players do today; and in politics, where being left-handed seems to help open the door to the White House. The telltale tooth markings, based on experiments, appear to result from how these Neanderthals and their relatives processed hides with stone tools, explained Frayer, a co-author of a paper on the findings published this month in the journal Laterality. One of his colleagues in Spain had people wear a mouth guard and then strike a hide as if they were cutting or stretching it with a stone tool. Every now and then, the test subjects were asked to whack their guarded teeth, as the researchers think would have accidentally happened as the ancient humans worked away.

Keyword: Laterality; Evolution
Link ID: 15251 - Posted: 04.21.2011

By THE NEW YORK TIMES Dr. Wiesner and Dr. Volkmar respond: Several readers had questions about the range of adult outcomes in autism and how treatments may affect outcomes in individual children. This is a very interesting and complicated — in a happy way – topic, because it seems like things are improving on balance, though not for every child. More and more individuals with autism are now able to function independently as adults. This is a major change over past decades, probably reflecting earlier diagnosis and more effective treatments. There is a very good summary of this in a chapter by Patricia Howlin in the Handbook of Autism (2005, Wiley). Unfortunately not every child gets better. Sometimes the outcome seems to relate to the severity of the autism in childhood. Individuals whose disability is more profound continue, as adults, to need considerable support and help. It is unfortunately the case that for this population, services are often minimal, research is sparse and resources are lacking. The federal government has identified this as a priority area in autism work, and rightly so. But even when we are fairly optimistic about an individual child, he or she may not do well as an adult. This is one of the reasons those of us who have been in the field for a long time are very careful about predicting the future to parents. We can only talk, in general, about what on average are good or bad prognostic factors. For individuals with autism who can go on to college, a number of resources are available on the Yale Child Study Center Web site, including books and links to programs. Options range from small and very supportive programs specific to individuals with autism and related disorders, to traditional colleges and universities. Our book, “A Practical Guide to Autism,” also has a chapter on the topic of adults and discusses college services. © 2011 The New York Times Company

Keyword: Autism
Link ID: 15250 - Posted: 04.21.2011

by Jon Hamilton Researchers have found evidence that the placenta plays an important role in fetal brain development during the early stages of pregnancy. Experiments in mice show that during a key period, the placenta becomes a source of the chemical serotonin, which helps determine the wiring of key circuits in the brain. The finding, published in the journal Nature, could help explain what leads to brain disorders such as autism and schizophrenia. And it shows that the placenta does a lot more than simply transport nutrients from a mother to her unborn baby. "The placenta is not just a passive bag of cells sitting there just allowing things to flow freely between the mom and the fetus," says Pat Levitt, director of the Zilhka Neurogenetic Institute at the University of Southern California's Keck School of Medicine. "We can think of it as a machine that can produce its own hormones, its own chemicals that can have an effect on the developing fetus itself," Levitt says. Levitt's research team discovered this while studying the role of serotonin in early brain development. The placenta itself is the source of a specific signal at a very particular period in development which is influencing the brain of the new child. And that influence is likely to be long lasting. Copyright 2011 NPR

Keyword: Development of the Brain
Link ID: 15249 - Posted: 04.21.2011

by Dan Jones IT IS the year 2500. Physicists have long had a Grand Unified Theory of Everything and neuroscientists now know precisely how the hardware of the brain runs the software of the mind and dictates behaviour. Lately, reports have begun to emerge that computer engineers at the Institute for Advanced Behavioural Prediction have built a quantum supercomputer that draws on these advances to predict the future, including what people will do and when. Trusted sources say that IABP researchers have secretly run thousands of predictions about citizens' behaviour - and they have never been wrong. Suddenly, deep philosophical questions are making headlines as commentators sound the death knell for free will. On the face of it, the consequences of proving all our actions are predetermined look bleak. Psychological experiments have shown that undermining people's sense of free will leads them to behave more dishonestly, more selfishly and more aggressively. But perhaps there is no need to panic. Some philosophers have found that our sense of free will is less threatened by determinism than the commentators suppose - so even faced with incontrovertible evidence that behaviour is predetermined, we still see ourselves as free and responsible for our own actions. Nothing will change. Who is correct? Will the public buy this reassuring message? Or will the manifest truth of determinism kill off belief in free will, taking down notions of moral culpability and punishment with it? Will nihilism, moral disintegration and anarchy follow? This is not merely an esoteric thought experiment. Neuroscientists increasingly describe our behaviour as the result of a chain of cause-and-effect, in which one physical brain state or pattern of neural activity inexorably leads to the next, culminating in a particular action or decision. With little space for free choice in this chain of causation, the conscious, deliberating self seems to be a fiction. From this perspective, all the real action is occurring at the level of synapses and neurotransmitters - putting us a lot closer to that deterministic world of 2500 than most people think. © Copyright Reed Business Information Ltd.

Keyword: Attention
Link ID: 15248 - Posted: 04.21.2011

The Neuroscience of the Gut By Robert Martone People may advise you to listen to your gut instincts: now research suggests that your gut may have more impact on your thoughts than you ever realized. Scientists from the Karolinska Institute in Sweden and the Genome Institute of Singapore led by Sven Pettersson recently reported in the Proceedings of the National Academy of Sciences that normal gut flora, the bacteria that inhabit our intestines, have a significant impact on brain development and subsequent adult behavior. We human beings may think of ourselves as a highly evolved species of conscious individuals, but we are all far less human than most of us appreciate. Scientists have long recognized that the bacterial cells inhabiting our skin and gut outnumber human cells by ten-to-one. Indeed, Princeton University scientist Bonnie Bassler compared the approximately 30,000 human genes found in the average human to the more than 3 million bacterial genes inhabiting us, concluding that we are at most one percent human. We are only beginning to understand the sort of impact our bacterial passengers have on our daily lives. Moreover, these bacteria have been implicated in the development of neurological and behavioral disorders. For example, gut bacteria may have an influence on the body’s use of vitamin B6, which in turn has profound effects on the health of nerve and muscle cells. They modulate immune tolerance and, because of this, they may have an influence on autoimmune diseases, such as multiple sclerosis. They have been shown to influence anxiety-related behavior, although there is controversy regarding whether gut bacteria exacerbate or ameliorate stress related anxiety responses. In autism and other pervasive developmental disorders, there are reports that the specific bacterial species present in the gut are altered and that gastrointestinal problems exacerbate behavioral symptoms. A newly developed biochemical test for autism is based, in part, upon the end products of bacterial metabolism. © 2011 Scientific American

Keyword: Autism; Obesity
Link ID: 15247 - Posted: 04.21.2011

The longer a man's fourth or ring finger is compared to his index finger, the more likely he is to be judged attractive by women, according to a study released Wednesday. The results, published in the British Royal Society's journal Biological Sciences, unveil intricate links between foetal exposure of males to hormones, the development of certain physical traits, and what turns on the opposite sex. It also adds to a growing body of research -- conducted under the banner of evolutionary psychology -- suggesting that the drivers of human behavior are found, more than previously suspected, in "nature" rather than "nurture." Earlier studies had already shown that the size ratio between the fourth and second fingers, especially of the right hand, is a reliable indicator of the extent a man was exposed to testosterone while still in the womb. The bigger the gap between a longer ring finger and a shorter index, the greater the likely impact of the hormone. For the new study, scientists led by Camille Ferdenzi of the University of Geneva designed an experiment to find out if women are drawn to the telltale signs of high testosterone levels in men -- a symmetrical face, a deeper voice, a particular body odor -- who have this more "masculine" finger configuration. More than 80 women university students between 18 and 34 looked at pictures of 49 similarly aged men, and were asked to evaluate them for masculinity and attractiveness. © 2011 Discovery Communications, LLC.

Keyword: Sexual Behavior
Link ID: 15246 - Posted: 04.21.2011

By Janet Raloff Children exposed in the womb to substantial levels of neurotoxic pesticides have somewhat lower IQs by the time they enter school than do kids with virtually no exposure. A trio of studies screened women for compounds in blood or urine that mark exposure to organophosphate pesticides such as chlorpyrifos, diazinon and malathion. These bug killers, which can cross the human placenta, work by inhibiting brain-signaling compounds. Although the pesticides’ residential use was phased out in 2000, spraying on farm fields remains legal. The three new studies began in the late 1990s and followed children through age 7. Pesticide exposures stem from farm work in more than 300 low-income Mexican-American families in California, researchers from the University of California, Berkeley and their colleagues report. In two comparably sized New York City populations, exposures likely trace to bug spraying of homes or eating treated produce. Among the California families, the average IQ for the 20 percent of children with the highest prenatal organophosphate exposure was 7 points lower compared with the least-exposed group. A Columbia University study followed low-income black and Hispanic families. Here, each additional 4.6 picrograms of chlorpyrifos per gram of blood in a woman during pregnancy correlated with a drop of 1.4 percent in her youngster’s IQ and 2.8 percent in a measure of the child’s working memory. © Society for Science & the Public 2000 - 2011

Keyword: Development of the Brain; Neurotoxins
Link ID: 15245 - Posted: 04.21.2011