By James Gallagher Health reporter, BBC News The idea of making brain cancers glow to help surgeons operate is being tested in the UK. Patients will be given a drug, 5-amino-levulinic acid (5-ALA), which causes a build-up of fluorescent chemicals in the tumour. The theory is that the pink glow will clearly mark the edges of the tumour, making it easier to ensure all of it is removed. More than 60 patients with glioblastoma will take part in the trial. They have cancerous glial cells, which normally hold the brain's nerves cells in place. On average patients survive 15 months after being diagnosed. No room for error In some cancers, such as those of the colon, some of the surrounding tissue can be removed as well as the tumour. Removing a brain tumour needs to be more precise. Dr Colin Watts, who is leading the trial at the University of Cambridge, told the BBC that surgeons "don't want to take too much functional tissue away". BBC © 2011

Keyword: Neurotoxins
Link ID: 15967 - Posted: 11.01.2011

by Helen Fields Happy people don't just enjoy life; they're likely to live longer, too. A new study has found that those in better moods were 35% less likely to die in the next 5 years when taking their life situations into account. The traditional way to measure a person's happiness is to ask them about it. But over the past few decades, psychologist and epidemiologist Andrew Steptoe of University College London (UCL) says, scientists have realized that those measures aren't reliable. It's not clear whether they "assess how they're actually feeling or how they remember feeling," he says. When answering, people are more likely to count their blessings and compare their experience with the lives of others. The English Longitudinal Study of Ageing tried to get more specific. It has followed more than 11,000 people age 50 and older since 2002. In 2004, about 4700 of them collected saliva samples four times in one day and, at those same times, rated how happy, excited, content, worried, anxious, and fearful they felt. The saliva samples are still awaiting analysis for stress hormones, but Steptoe and his UCL colleague Jane Wardle publish findings today on the links between mood and mortality in the Proceedings of the National Academy of Sciences . Of the 924 people who reported the least positive feelings, 7.3%, or 67, died within 5 years. For people with the most positive feelings, the rate fell in half, to 3.6%, or 50 of 1399 people. Of course, it's possible that people who died sooner weren't as chipper because they were deathly ill or because of any number of other factors that affect both mortality and mood. The researchers adjusted for age, sex, demographic factors such as wealth and education, signs of depression, health (including whether they'd been diagnosed with major diseases), and health behaviors such as smoking and physical activity. Even with those adjustments, the risk of dying in the next 5 years was still 35% lower for the happiest people. © 2010 American Association for the Advancement of Science

Keyword: Emotions
Link ID: 15966 - Posted: 11.01.2011

By Danielle Perszyk Are humans the only species with enough smarts to craft a language? Most of us believe that we are. Although many animals have their own form of communication, none has the depth or versatility heard in human speech. We are able to express almost anything on our mind by uttering a few sounds in a particular order. Human language has a flexibility and complexity that seems to be universally shared across cultures and, in turn, contributes to the variation and richness we find among human cultures. But are the rules of grammar unique to human language? Perhaps not, according to a recent study, which showed that songbirds may also communicate using a sophisticated grammar—a feature absent in even our closest relatives, the nonhuman primates. Kentaro Abe and Dai Watanabe of Kyoto University performed a series of experiments to determine whether Bengalese finches expect the notes of their tunes to follow a certain order. To test this possibility, Abe and Watanabe took advantage of a behavioral response called habituation, where animals zone-out when exposed to the same stimulus over and over again. In each experiment, the birds were presented with the same songs until they became familiarized with the tune. The researchers then created novel songs by shuffling the notes around. But not every new song caught the birds’ attention; rather, the finches increased response calls only to songs with notes arranged in a particular order, suggesting that the birds used common rules when forming the syntax of that song. When the researchers created novel songs with even more complicated artificial grammar—for example, songs that mimicked a specific feature found in human (Japanese) language—the birds still only responded to songs that followed the rules. © 2011 Scientific American

Keyword: Language; Evolution
Link ID: 15965 - Posted: 10.29.2011

Sandrine Ceurstemont, editor, New Scientist TV A ring trapped in a box seems determined to escape in this latest illusion by psychophysiologist Marcel de Heer. To create the brain trick, he created a virtual material with unique properties. The exterior surface is transparent and the interior is lined with a red and yellow pattern. "The material is similar to a one-way mirror," says de Heer. "From one side, you can see through it. From the other side, you see a coloured pattern instead of a mirror." As the box turns, the ring's behaviour starts to get unusual. When viewed from behind, you can see through it. But as it rotates so that it faces you, it sometimes seems to spin in the opposite direction and escape from the box. De Heer isn't exactly sure why we experience the effect, although it's a variation of the hollow mask illusion. Since we are used to seeing convex surfaces like faces, our brain is sometimes tricked by hollow structures and they appear to bulge out. In this case, the curious material seems to confuse our brain in the same way. © Copyright Reed Business Information Ltd.

Keyword: Vision
Link ID: 15964 - Posted: 10.29.2011

by Arran Frood The visions induced by an Amazonian brew used by shamans may be as real as anything the eyes actually see, according to brain scans of frequent users of the drug. Draulio de Araujo of the Brain Institute at the Federal University of Rio Grande do Norte in Natal, Brazil, and colleagues recruited 10 frequent users of the brew – called ayahuasca. They asked the volunteers to look at images of people or animals while their brains were scanned using functional MRI, then asked the volunteers to close their eyes and imagine they were still viewing the image. Unsurprisingly, the researchers found that neural activity in the primary visual cortex dropped off when volunteers imagined seeing the image rather than actually viewing it. But when the team then gave the volunteers a dose of ayahuasca and repeated the experiment, they found that the level of activity in the primary visual cortex was virtually indistinguishable when the volunteers were really viewing an image and when they were imagining it. This means visions seen have a real, neurological basis, says de Araujo – they are not made up or imagined. Michael Brammer, head of the brain imaging unit at King's College London, says the study's statistics appear to indicate something relatively robust. However, he says it's difficult to pin down whether the eyes-closed responses on the drug are quantitatively the same as normal, eyes-open neural activity. "Functional MRI is not a one-to-one mapping of cerebral activity. If it were, things would be easier," he says. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse; Brain imaging
Link ID: 15963 - Posted: 10.29.2011

IF YOU think the art of mind-reading is a conjuring trick, think again. Over the past few years, the ability to connect first monkeys and then men to machines in ways that allow brain signals to tell those machines what to do has improved by leaps and bounds. In the latest demonstration of this, just published in the Public Library of Science, Bin He and his colleagues at the University of Minnesota report that their volunteers can successfully fly a helicopter (admittedly a virtual one, on a computer screen) through a three-dimensional digital sky, merely by thinking about it. Signals from electrodes taped to the scalp of such pilots provide enough information for a computer to work out exactly what the pilot wants to do. That is interesting and useful. Mind-reading of this sort will allow the disabled to lead more normal lives, and the able-bodied to extend their range of possibilities still further. But there is another kind of mind-reading, too: determining, by scanning the brain, what someone is actually thinking about. This sort of mind-reading is less advanced than the machine-controlling type, but it is coming, as three recently published papers make clear. One is an attempt to study dreaming. A second can reconstruct a moving image of what an observer is looking at. And a third can tell what someone is thinking about. First, dreams. To study them, Martin Dresler, of the Max Planck Institute of Psychiatry, in Munich, and his colleagues recruited a group of what are known as lucid dreamers. They report their results in this week’s Current Biology. © The Economist Newspaper Limited 2011

Keyword: Brain imaging; Sleep
Link ID: 15962 - Posted: 10.29.2011

By Laura Sanders Human brains all work pretty much the same and use roughly the same genes in the same way to build and maintain the infrastructure that makes people who they are, two new studies show. And by charting the brain’s genetic activity from before birth to old age, the studies reveal that the brain continually remodels itself in predictable ways throughout life. In addition to uncovering details of how the brain grows and ages, the results may help scientists better understand what goes awry in brain disorders such as schizophrenia and autism. “The complexity is mind-numbing,” says neuroscientist Stephen Ginsberg of the Nathan Kline Institute and New York University Langone Medical Center, who wasn’t involved in the studies. “It puts the brain in rarefied air.” In the studies, published in the Oct. 27 Nature, researchers focused not on DNA — virtually every cell’s raw genetic material is identical — but on when, where and for how long each gene is turned on over the course of a person’s life. To do this, the researchers measured levels of mRNA, a molecule whose appearance marks one of the first steps in executing the orders contained in a gene, in postmortem samples of donated brains that ranged in age from weeks after conception to old age. These different patterns of mRNA levels distinguish the brain from a heart, for instance, and a human from a mouse, too, says Nenad Šestan of Yale University School of Medicine and coauthor of one of the studies. “Essentially, we carry the same genes as mice,” he says. “However, in us, these genes are up to something quite different.” © Society for Science & the Public 2000 - 2011

Keyword: Genes & Behavior
Link ID: 15961 - Posted: 10.29.2011

Despite vast differences in the genetic code across individuals and ethnicities, the human brain shows a "consistent molecular architecture," say researchers supported by the National Institutes of Health. The finding is from a pair of studies that have created databases revealing when and where genes turn on and off in multiple brain regions through development. "Our study shows how 650,000 common genetic variations that make each of us a unique person may influence the ebb and flow of 24,000 genes in the most distinctly human part of our brain as we grow and age," explained Joel Kleinman, M.D., Ph.D., of the National Institute of Mental Health (NIMH) Clinical Brain Disorders Branch. Kleinman and NIMH grantee Nenad Sestan, M.D., Ph.D. of Yale University, New Haven, Conn., led the sister studies in the Oct. 27, 2011 issue of the journal Nature. genetic difference vs. transcriptional distance colored by race comparison. Our brains are all made of the same stuff. Despite individual and ethnic genetic diversity, our prefrontal cortex shows a consistent molecular architecture. For example, overall differences in the genetic code (“genetic distance”) between African -Americans (AA) and caucasians (cauc) showed no effect on their overall difference in expressed transcripts (“transcriptional distance”). The vertical span of color-coded areas is about the same, indicating that our brains all share the same tissue at a molecular level, despite distinct DNA differences on the horizontal axis. Each dot represents a comparison between two individuals. The AA::AA comparisons (blue) generally show more genetic diversity than cauc::cauc comparisons (yellow), because caucasians are descended from a relatively small subset of ancestors who migrated from Africa, while African Americans are descended from a more diverse gene pool among the much larger population that remained in Africa. AA::cauc comparisons (green) differed most across their genomes as a whole, but this had no effect on their transcriptomes as a whole. Source: Joel Kleinman, M.D., Ph.D., NIMH Clinical Brain Disorders Branch

Keyword: Genes & Behavior
Link ID: 15960 - Posted: 10.29.2011

By Dina ElBoghdady, A chemical used widely in plastic bottles, metal cans and other consumer products could be linked to behavioral and emotional problems in toddler girls, according to a government-funded study published online Monday in the journal Pediatrics. After tracking 244 Cincinnati-area mothers and their 3-year-olds, the study concluded that mothers with high levels of bisphenol A (BPA) in their urine were more likely to report that their children were hyperactive, aggressive, anxious, depressed and less in control of their emotions than mothers with low levels of the chemical. While several studies have linked BPA to behavioral problems in children, this report is the first to suggest that a young girl’s emotional well-being is linked to her mother’s exposure during pregnancy rather than the child’s exposure after birth. Girls were more sensitive to the chemical in the womb than boys, maybe because BPA mimics the female hormone estrogen, which is thought to play a role in behavioral development. The results add to a growing body of research that suggests exposure to BPA poses health risks in humans. While the federal government has long maintained that low doses of BPA are safe, the Food and Drug Administration and other federal agencies are taking a closer look and investing in more research about the chemical’s health effects. © 1996-2011 The Washington Post

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 15959 - Posted: 10.29.2011

by Kim Krieger Some sounds are excruciating. Take fingernails squeaking on a chalkboard. The noise makes many people shudder, but researchers never knew exactly why. A new study finds that there are two factors at work: the knowledge of where the sound is coming from and the unfortunate design of our ear canals. Previous research found that the painful parts of unpleasant sounds appear to be in the middle range of audible frequencies. But scientists didn’t nail down exactly which frequencies or explain why the sounds were painful. So musicologists Michael Oehler of the Macromedia University for Media and Communication in Cologne, Germany, and Christoph Reuter of the University of Vienna asked listeners to rank sounds in a listening test. Fingernails raking against a chalkboard and chalk squeaking against slate were the most unpleasant sounds from a family of recordings, which also included sounds such as Styrofoam squeaks and scraping a plate with a fork. The researchers then modified the recordings of fingernails and chalk, removing or attenuating various frequency ranges. They also modified the sounds by selectively extracting either the tonal, musical-pitch parts or the scraping, growling, noiselike parts of the sound. Some listeners were told the true source of the sounds, whereas others were told that the sounds were part of contemporary musical compositions. The same listeners then rated the pleasantness or unpleasantness of the sounds while the researchers measured physical indicators of distress: the listeners’ heart rate, blood pressure, and the electrical conductivity of their skin. As they will report next week at the Acoustical Society of America conference in San Diego, California, Oehler and Reuter found that a listener’s skin conductivity changed significantly when the person heard a sound he or she later reported as unpleasant, showing that disturbing sounds do cause a measurable physical reaction. More surprisingly, they found that the frequencies responsible for making a sound unpleasant were commonly found in human speech, which ranges from 150 to 7000 hertz (Hz). The offending frequencies were in the range of 2000 to 4000 Hz. Removing those made the sounds much easier to listen to. Deleting the tonal parts of the sound entirely also made listeners perceive the sound as more pleasant, whereas removing other frequencies or the noisy, scraping parts of the sound made little difference. © 2010 American Association for the Advancement of Science.

Keyword: Hearing
Link ID: 15958 - Posted: 10.29.2011

by David Eagleman Only a tiny fraction of the brain is dedicated to conscious behavior. The rest works feverishly behind the scenes regulating everything from breathing to mate selection. In fact, neuroscientist David Eagleman of Baylor College of Medicine argues that the unconscious workings of the brain are so crucial to everyday functioning that their influence often trumps conscious thought. To prove it, he explores little-known historical episodes, the latest psychological research, and enduring medical mysteries, revealing the bizarre and often inexplicable mechanisms underlying daily life. Eagleman’s theory is epitomized by the deathbed confession of the 19th-century mathematician James Clerk Maxwell, who developed fundamental equations unifying electricity and magnetism. Maxwell declared that “something within him” had made the discoveries; he actually had no idea how he’d achieved his great insights. It is easy to take credit after an idea strikes you, but in fact, neurons in your brain secretly perform an enormous amount of work before inspiration hits. The brain, Eagleman argues, runs its show incognito. Or, as Pink Floyd put it, “There’s someone in my head, but it’s not me.” There is a looming chasm between what your brain knows and what your mind is capable of accessing. Consider the simple act of changing lanes while driving a car. Try this: Close your eyes, grip an imaginary steering wheel, and go through the motions of a lane change. Imagine that you are driving in the left lane and you would like to move over to the right lane. Before reading on, actually try it. I’ll give you 100 points if you can do it correctly. © 2011, Kalmbach Publishing Co.

Keyword: Attention
Link ID: 15957 - Posted: 10.29.2011

By Wynne Parry Marijuana hurts memory and cognition, and a new rat study indicates this is because it causes once-coordinated brain regions to fall out of sync with each other. The result resembles the effects of schizophrenia, the neuroscientists found. The researchers measured the electrical activity in nerve cells of rats given a drug that mimics the effect of the psychoactive ingredient in marijuana, called tetrahydrocannabinol (THC). The drug had only subtle effects on individual brain regions; however, it disrupted the coordinated activity between regions of the brain. Specifically, they found the drug disrupted the coordinated fluctuations in electrical activity -- called brain waves -- across the hippocampus and prefrontal cortex. The result resembled two instruments within an orchestra playing out of sync. A lack of synchronization between the hippocampus and the prefrontal cortex -- areas of the brain associated with memory and decision-making -- is also associated with schizophrenia. A group of severe brain disorders, schizophrenia causes people to interpret reality abnormally. Its symptoms may include a combination of hallucinations, delusions and disordered thinking and behavior, according to the Mayo Clinic. As a result of the disruption to their brain activity, the rats became unable to make accurate decisions when navigating around a maze. © 2011 CBS Interactive Inc

Keyword: Learning & Memory; Drug Abuse
Link ID: 15956 - Posted: 10.27.2011

by Valerie Ross Some might call skin the unsung hero of organs. It provides waterproofing, mediates sensation, guards against germs, and—as if that’s not enough—now researchers believe it may serve as a valuable repository of brain cells. Last spring, scientists at the Salk Institute in California announced the creation of a technique for transforming simple skin cells scraped from patients with schizophrenia into functional neurons, a major step toward more personalized, noninvasive approaches to drug testing. “Psychiatrists give patients first line, second line, third line drugs, hoping that one will work,” says Salk neuroscientist Fred Gage, who led the research. Pre-screening drugs on patient-derived cells could increase the odds of picking the right drug from the beginning. After collecting skin cells from people with and without schizophrenia, Gage and team genetically reprogrammed the cells to become pluripotent stem cells, with the youthful ability to give rise to any of the more than 200 cell types in the body. From there, the blank-slate cells were bathed in a biochemical solution designed to mimic the developmental conditions of a brain cell. A month later, the cells from the healthy volunteers looked nearly identical to conventional brain cells, while the cells from the schizophrenic patients were smaller and formed fewer connections, hinting at the physical root of the disease. In further tests, the diseased neurons responded in petri dishes to five schizophrenia drugs. One common medication, loxapine, boosted the number of connections among the cells, providing a window into how the medication might work in the brain. © 2011, Kalmbach Publishing Co.

Keyword: Stem Cells; Schizophrenia
Link ID: 15955 - Posted: 10.27.2011

Analysis by Marianne English Experts say a surplus of alcohol -- not a lack of it-- killed British singer Amy Winehouse in July. The news overturns the idea that alcohol withdrawal led to the pop star's death. Instead, pathology reports point to alcohol poisoning as the culprit. So what's alcohol poisoning, and how's it different from alcoholism? Alcohol poisoning occurs from drinking large amounts within a short period of time, most likely from binge drinking. In some cases, poisoning stems from extensive exposure to lotions, paints and cleaning products, according to the Mayo Clinic. Poisoning calls for immediate medical attention. Depending on the situation, emergency rooms can help flush alcohol out of a person's system. Other cases might be too severe and can kill a person. Most events involve people abusing alcoholic beverages. Drinking too fast, or consuming more alcohol than the liver can metabolize in a given period of time, causes a person's blood alcohol level to spike. High levels limit involuntary functions, including regular heart beating and breathing. A person's gag reflex, which can help expel the alcohol (through vomiting), can be suppressed as well. © 2011 Discovery Communications, LLC.

Keyword: Drug Abuse
Link ID: 15954 - Posted: 10.27.2011

By Tina Hesman Saey A genetic variant that makes small tweaks in an important brain protein may cause aging to hit some people’s brains harder than others. Pilots’ performance on a flight simulator test generally declines slightly with age. But a new study shows that pilots with a particular version of a gene called BDNF have a faster drop than others. Researchers also observed a decline in the size of an important learning and memory center in the brains of those with the variant, Ahmad Salehi of the Department of Veterans Affairs Palo Alto Health Care System and Stanford University, and colleagues report online October 25 in Translational Psychiatry. About 38 percent of pilots in the new study carried the variant in either one or both of their copies of the BDNF gene. Over the course of two years the flight simulator scores of all the pilots in the study declined a little with age. But scores of pilots carrying the variant dropped about three times faster than scores of pilots who have the normal version of the gene. The drop in scores was not so dramatic that pilots should be removed from the cockpit, says Salehi. “It certainly did not disable them at all,” he says. But the score drop did reflect a slightly faster decline in factors like reaction time, navigation skills, plane positioning and performance in emergency situations. For some of the pilots, the researchers measured the size of the hippocampus, a structure in the brain that is important for learning and memory. After age 65, men who had the alternate version of the gene also lost more hippocampus volume than men with the normal version of the gene, the researchers found. The size of the hippocampus did not correlate with scores on flight simulator tests, probably because flying a plane requires much more of the brain than just the hippocampus, Salehi says. © Society for Science & the Public 2000 - 2011

Keyword: Genes & Behavior; Development of the Brain
Link ID: 15953 - Posted: 10.27.2011

By GINA KOLATA For years, studies of obesity have found that soon after fat people lost weight, their metabolism slowed and they experienced hormonal changes that increased their appetites. Scientists hypothesized that these biological changes could explain why most obese dieters quickly gained back much of what they had so painfully lost. But now a group of Australian researchers have taken those investigations a step further to see if the changes persist over a longer time frame. They recruited healthy people who were either overweight or obese and put them on a highly restricted diet that led them to lose at least 10 percent of their body weight. They then kept them on a diet to maintain that weight loss. A year later, the researchers found that the participants’ metabolism and hormone levels had not returned to the levels before the study started. The study, being published Thursday in The New England Journal of Medicine, is small and far from perfect, but confirms their convictions about why it is so hard to lose weight and keep it off, say obesity researchers who were not involved the study. They cautioned that the study had only 50 subjects, and 16 of them quit or did not lose the required 10 percent of body weight. And while the hormones studied have a logical connection with weight gain, the researchers did not show that the hormones were causing the subjects to gain back their weight. Nonetheless, said Dr. Rudolph Leibel, an obesity researcher at Columbia, while it is no surprise that hormone levels changed shortly after the participants lost weight, “what is impressive is that these changes don’t go away.” © 2011 The New York Times Company

Keyword: Obesity
Link ID: 15952 - Posted: 10.27.2011

By Jennifer Nalewicki After years of fumbling while reading the written word, Christian Boer, a graphic designer from the Netherlands, has developed a way to help tackle his dyslexia. The 30-year-old created a font called Dyslexie that has proved to decrease the number of errors made by dyslexics while reading. The font works by tweaking the appearance of certain letters of the alphabet that dyslexics commonly misconstrue, such as "d" and "b," to make them more recognizable. This month Boer released the font in English for U.S. users to purchase online. Boer began designing the font in 2008 while studying at the University of Twente in the Netherlands. It eventually became his graduate school project. In December 2010 a fellow student conducted an independent study on the font as part of a master's thesis and discovered a significant reduction in reading errors by dyslexics when reading Dutch text typed in Dyslexie as opposed to the Arial font. Boer's research could likewise have a big impact on English speakers, given the prevalence of dyslexia when reading that language, as compared with Italian, whose words are pronounced more closely to how they are spelled. In the U.S. one out of every five persons is dyslexic, according to the National Institutes of Health. Unlike other readers, dyslexics have a tendency to rotate, swap and mirror letters, making it difficult for them to comprehend what they’re reading. For years it was thought that dyslexia was a vision problem, but scientists now know that the condition stems from the brain. Scans of dyslexic brains show that there are structural differences—including in the thalamus, which serves an information way station—when compared with other brains. Some dyslexics even see letters as suspended 3-D animations that twist before their eyes. "I perceived letters floating like balloons in my head," Boer says. As a means to finally "tie down" these balloons, Boer dedicated his time and graphic design skills to come up with Dyslexie. © 2011 Scientific American,

Keyword: Dyslexia
Link ID: 15951 - Posted: 10.27.2011

By Tina Hesman Saey The spark that ignites multiple sclerosis may come from within. A new study in mice points to normal intestinal bacteria as a trigger for the immune disorder. In patients with multiple sclerosis, the body’s immune system attacks the brain, stripping away a protective sheath called myelin from nerve cells. This causes inflammation that leads to the disease. Although the exact causes of MS are not known, scientists generally agree that a genetic predisposition combines with one or more environmental triggers to set off the attack on the brain. The new study provides evidence that friendly bacteria may be one of those triggers. Mice genetically engineered to develop multiple sclerosis–like symptoms don’t get the disease when raised without any bacteria in their guts, a research team from Germany reports online October 26 in Nature. But germ-free mice that were then colonized with intestinal bacteria quickly developed the disease, the team found. About 80 percent of mice with intestinal bacteria developed MS-like symptoms, but none of the germ-free mice did. The result is not a total surprise. Previous reports had indicated that gut bacteria might be involved in autoimmune disorders such as MS, juvenile diabetes and arthritis, says Simon Fillatreau, an immunologist at the German Rheumatism Research Center in Berlin. “So maybe it was expected, but that it is really such a black-and-white response? Probably not,” says Fillatreau, who was not involved in the study. “It’s very big news.” © Society for Science & the Public 2000 - 2011

Keyword: Multiple Sclerosis
Link ID: 15950 - Posted: 10.27.2011

Many yoghurts are loaded with live bacteria, and labelled with claims that consuming these microorganisms can be good for your health. But a study published today shows that such yoghurts have only subtle effects on the bacteria already in the gut and do not replace them. Nathan McNulty, a microbiologist at Washington University in St Louis, Missouri, recruited seven pairs of identical twins, and asked one in each pair to eat twice-daily servings of a popular yoghurt brand containing five strains of bacteria. By sequencing bacterial DNA in the twins' stool samples, the team showed that the yoghurt microbes neither took up residence in the volunteers' guts, nor affected the make-up of the local bacterial communities. Jeffrey Gordon, the microbiologist at Washington University who led the study, was not surprised. "We were only giving several billion bacterial cells in total to the twins, who harbour tens of trillions of gut microbes in their intestines," he says. McNulty also fed the five bacterial strains from the yoghurt to 'gnotobiotic' mice — animals raised so that the only microorganisms that their guts contain are 15 species found in humans. As with the twins, the yoghurt bacteria did not change the composition of the rodents' resident communities. However, the activity of genes that allow the native bacteria to break down carbohydrates did increase. One of the five yoghurt strains — Bifidobacterium animalis lactis — also showed a similar boost in its ability to metabolize carbohydrates. © 2011 Nature Publishing Group,

Keyword: Obesity
Link ID: 15949 - Posted: 10.27.2011

By Nick Collins, Science Correspondent Children who are short-sighted spend an average of 3.7 fewer hours a week outside compared with those who have normal vision or are long sighted, a review of previous research has found. Nearsightedness, or myopia, runs in families and has also been linked to a host of factors including the amount of time spent focusing on near objects, for example when reading, and levels of physical activity. But simply spending time out of the house may also be enough to protect the eyesight. The positive effect from being outdoors appeared to be independent from the amount of time children spent reading or playing computer games, or to an increased amount of exercise, researchers said. Between 15 and 20 per cent of British people are short-sighted but the problem is much more serious in parts of east Asia where as many as 80 per cent of the population is myopic. One study comparing Chinese children living in different countries found that those in Australia had better vision on average than their peers in China and Singapore. The Australian group read as much and achieved the same results academically as those in other countries, but tended to spend more time outdoors. The review of eight studies by Dr Justin Sherwin and Dr Anthony Khawaja, covering 10,400 participants in total, was presented to the American Academy of Opthalmology on Monday. © Copyright of Telegraph Media Group Limited 2011

Keyword: Vision; Development of the Brain
Link ID: 15948 - Posted: 10.27.2011