By DENISE GRADY The bacterial makeup of the intestines may help determine whether people gain weight or lose it, according to two new studies, one in humans and one in mice. The research also suggests that a popular weight-loss operation, gastric bypass, which shrinks the stomach and rearranges the intestines, seems to work in part by shifting the balance of bacteria in the digestive tract. People who have the surgery generally lose 65 percent to 75 percent of their excess weight, but scientists have not fully understood why. Now, the researchers are saying that bacterial changes may account for 20 percent of the weight loss. The findings mean that eventually, treatments that adjust the microbe levels, or “microbiota,” in the gut may be developed to help people lose weight without surgery, said Dr. Lee M. Kaplan, director of the obesity, metabolism and nutrition institute at the Massachusetts General Hospital, and an author of a study published Wednesday in Science Translational Medicine. Not everyone who hopes to lose weight wants or needs surgery to do it, he said. About 80 million people in the United States are obese, but only 200,000 a year have bariatric operations. “There is a need for other therapies,” Dr. Kaplan said. “In no way is manipulating the microbiota going to mimic all the myriad effects of gastric bypass. But if this could produce 20 percent of the effects of surgery, it will still be valuable.” In people, microbial cells outnumber human ones, and the new studies reflect a growing awareness of the crucial role played by the trillions of bacteria and other microorganisms that live in their own ecosystem in the gut. Perturbations there can have profound and sometimes devastating effects. © 2013 The New York Times Company

Keyword: Obesity
Link ID: 17959 - Posted: 03.28.2013

By Puneet Kollipara Blind fish that spend their lives in dark, underwater caves have lost a huge chunk of their ability to hear, scientists report in the March 27 Biology Letters. Two of the fish species studied could not hear high-pitched sounds. “I was really surprised,” says study coauthor Daphne Soares of the University of Maryland, College Park. “I expected them to hear much better than the surface fishes.” Cave-dwelling fish can lose their vision and even their eyes over many generations. And without light, eyesight can lose its importance in fish survival. Only two previous studies have explored what happens to hearing after fish lose their vision; both found no differences in hearing between cave fish and those that experience daylight. Soares and her colleagues collected fish of two blind cave-dwelling species, Typhlichthys subterraneus and Amblyopsis spelaea, from lakes in Kentucky. Specimens of a surface-dwelling species, Forbesichthys agassizii, which is closely related to the cave dwellers, came from a lake in south-central Tennessee. Back in the lab, the researchers tested fish hearing by seeing whether sounds across a range of pitches could stimulate nerve activity in the fishes’ brains. The researchers also measured the density of sound-detecting hair cells in the creatures’ ears. © Society for Science & the Public 2000 - 2013

Keyword: Vision; Hearing
Link ID: 17958 - Posted: 03.28.2013

by Niall Firth Automatic systems that analyse gestures and facial expressions may soon be helping psychologists pick up the easily missed symptoms of depression The interviewee shifts uncomfortably in his seat before stumbling over his answer. The movement, hesitation and telltale gaze aversion are noted: this person may be depressed. The probing questioner is SimSensei, a digital avatar that interviews humans to judge their state of mind. SimSensei is one of several new initiatives designed to partially automate one of the medical profession's trickiest tasks: diagnosing depression. SimSensei is more than an astute questioner. Behind the scenes, it uses face recognition technology and depth-sensing cameras built into Microsoft's Kinect to record and interpret the interviewee's body language. The animated psychologist can then respond appropriately. In work to be presented at the Automatic Face and Gesture Recognition conference in Shanghai, China, next month, Stefan Scherer of the University of Southern California and colleagues used the system to identify characteristic movements that indicate someone may be depressed. To extract the right features, his team interviewed a mixture of healthy volunteers and those who had previously been diagnosed with depression or post-traumatic stress disorder. © Copyright Reed Business Information Ltd

Keyword: Depression
Link ID: 17957 - Posted: 03.28.2013

By Meghan Rosen With parasitic flies gorging on her guts and the end approaching, a variable field cricket may have only one thing to do: Find a mate. Usually, female Gryllus lineaticeps prefer males with fast chirps. But when being eaten alive by fly larvae, female crickets don’t wait around for a snappy tune. Instead, they settle for slow-chirping sexual partners, evolutionary biologists Oliver Beckers of Indiana University in Bloomington and William Wagner Jr. of the University of Nebraska-Lincoln report in the April Animal Behaviour. Parasitic flies seek out crickets as potential homes (and meal tickets) for their young. Before the fly larvae chew through crickets’ bellies, female crickets have about a week to find a mate and lay eggs before dying. To find out whether infestation lowered females’ mating standards, Beckers and Wagner placed fly larvae on female crickets and then played slow and fast chirp recordings from loudspeakers set in separate corners of a square chamber. Healthy females walked toward the fast chirping sound about 80 percent of the time, while infested females split their devotion about equally. “They don’t invest a lot of time and energy finding the super sexy guy,” says Becker. “They’ll go for the average Joe.” © Society for Science & the Public 2000 - 2013

Keyword: Sexual Behavior; Evolution
Link ID: 17956 - Posted: 03.27.2013

by Beth Skwarecki If you thought the battle of the genders was complicated, try having seven sexes. When Tetrahymena, a single-celled creature covered in cilia, mates, the offspring isn't necessarily the same sex as either parent—it can be any of seven. Now, researchers have figured out the complex dance of DNA that determines the offspring's sex, and it's a random selection, they report today in PLOS Biology. Each Tetrahymena has a gene for its own sex—or mating type—in its regular nucleus, but it also carries a second nucleus used only for reproduction. This "germline nucleus" contains incomplete versions of all seven mating type genes, which are cut and pasted together until one complete gene remains and the other six have been deleted. The newly rearranged DNA becomes part of the offspring's regular nucleus, determining its mating type. Because the mating type gene helps Tetrahymena recognize others of a different sex, the researchers say that the finding could shed light on how other cells, including those in humans, recognize those that are different from themselves. © 2010 American Association for the Advancement of Science.

Keyword: Sexual Behavior; Evolution
Link ID: 17955 - Posted: 03.27.2013

Alternating between periods of eating and fasting is gaining in popularity among dieters and generating criticism in nutritional circles. Intermittent fasting, sometimes known as the 5:2 diet, asks people to eat very little or nothing at times, such as eating normally for five days a week and fasting for the other two. Brad Pilon designed one of the first intermittent fasts that became popular after he published a guide, Eat Stop Eat. Pilon said the diet allows followers to eat the foods they crave most of the time and still lose weight. "In the fasted state your body's set up to burn the calories you stored while eating," said Pilon. "So it's set up specifically for the act of burning body fat." Cutting down on weekly calorie intake is generally recommended. And there's research underway into the hypothesis that restricting calories could extend a healthy lifespan. Critics of intermittent fasting say that besides burning unwanted fat, the body will also burn its building blocks. "So when those energy stores start to drop the body looks for other sources and it goes to the muscles and burns muscle," said Margaret De Melo, a registered dietician at Toronto Western Hospital. © CBC 2013

Keyword: Obesity
Link ID: 17954 - Posted: 03.27.2013

by Anil Ananthaswamy, A YOUNG man lies unconscious on the table, his head clamped firmly in place. His eyes are closed. The hair over his left temple has been shaved. I'm in the operating room at University Hospital Zurich in Switzerland with neurologist Thomas Grunwald, who has diagnosed 22-year-old Jeremy Künzler with drug-resistant temporal lobe epilepsy. His symptoms during fits suggest that the seizures begin in the left temporal lobe. Often, this condition can only be treated by surgically removing the errant brain tissue. Unfortunately, brain scans have revealed nothing that would point to the source of Künzler's seizures – no obvious tumour, scar or lesion. In ordinary circumstances, Künzler would have to undergo exploratory brain surgery. But instead of this drastic operation, Grunwald is pioneering a technique to pinpoint the problem area. He has asked neurosurgeon Niklaus Krayenbühl to implant electrodes inside Künzler's skull: a grid electrode over his left temporal lobe, and two strip electrodes beneath the left and right lobes, used to monitor activity bilaterally in the hippocampi and amygdalae. Once they are in place, Grunwald will record brain signals in real time during seizures and use the information to try to identify the epileptogenic tissue. It's my first time inside an operating room. I'm anxious, as I have been told not to touch a thing for fear of contamination, especially the giant surgical microscope covered in clear, sterile plastic. "The nurses are very strict," says Grunwald. "If you touch this, even with your head, they get really angry." © Copyright Reed Business Information Ltd.

Keyword: Epilepsy
Link ID: 17953 - Posted: 03.27.2013

By HARRIET BROWN Mental-health care has come a long way since the remedy of choice was trepanation — drilling holes into the skull to release “evil spirits.” Over the last 30 years, treatments like cognitive-behavioral therapy, dialectical behavior therapy and family-based treatment have been shown effective for ailments ranging from anxiety and depression to post-traumatic stress disorder and eating disorders. The trouble is, surprisingly few patients actually get these kinds of evidence-based treatments once they land on the couch — especially not cognitive behavioral therapy. In 2009, a meta-analysis conducted by leading mental-health researchers found that psychiatric patients in the United States and Britain rarely receive C.B.T., despite numerous trials demonstrating its effectiveness in treating common disorders. One survey of nearly 2,300 psychologists in the United States found that 69 percent used C.B.T. only part time or in combination with other therapies to treat depression and anxiety. C.B.T. refers to a number of structured, directive types of psychotherapy that focus on the thoughts behind a patient’s feelings and that often include exposure therapy and other activities. Instead, many patients are subjected to a kind of dim-sum approach — a little of this, a little of that, much of it derived more from the therapist’s biases and training than from the latest research findings. And even professionals who claim to use evidence-based treatments rarely do. The problem is called “therapist drift.” “A large number of people with mental health problems that could be straightforwardly addressed are getting therapies that have very little chance of being effective,” said Glenn Waller, chairman of the psychology department at the University of Sheffield and one of the authors of the meta-analysis. Copyright 2013 The New York Times Company

Keyword: Depression
Link ID: 17952 - Posted: 03.26.2013

by Traci Watson You say you want to be alone? Think again. Researchers have found that older people with fewer human contacts are more likely to die—even if they're happy in their solitude—than are people with richer social lives. The study adds to the debate over whether loneliness, social isolation, or some combination of the two leads to higher mortality. Social isolation is an objective condition in which people have little interaction with others. Loneliness, on the other hand, is an emotional state felt by people who are dissatisfied with their social connections. "Someone who's socially isolated is likely to be lonely, and vice versa, but that's not completely the case," says epidemiologist and lead author Andrew Steptoe of University College London. To tease apart the effects of being alone versus just feeling lonely, Steptoe and his colleagues examined data from 6500 Britons aged 50 and up who had filled out questionnaires assessing their levels of loneliness. The researchers also tabulated the subjects' contacts with friends, family, religious groups, and other organizations to gauge their social connections. Then they counted how many subjects died over a 7-year period. The most socially isolated subjects had a 26% greater risk of dying, even when sex, age, and other factors linked to survival were accounted for, the researchers report online today in the Proceedings of the National Academy of Sciences. They then tweaked their model to determine whether the connection to death was due to the fact that isolated people are often lonely. It wasn't. © 2010 American Association for the Advancement of Science

Keyword: Emotions; Stress
Link ID: 17951 - Posted: 03.26.2013

Regina Nuzzo In a twist that evokes the dystopian science fiction of writer Philip K. Dick, neuroscientists have found a way to predict whether convicted felons are likely to commit crimes again from looking at their brain scans. Convicts showing low activity in a brain region associated with decision-making and action are more likely to be arrested again, and sooner. Kent Kiehl, a neuroscientist at the non-profit Mind Research Network in Albuquerque, New Mexico, and his collaborators studied a group of 96 male prisoners just before their release. The researchers used functional magnetic resonance imaging (fMRI) to scan the prisoners’ brains during computer tasks in which subjects had to make quick decisions and inhibit impulsive reactions. The scans focused on activity in a section of the anterior cingulate cortex (ACC), a small region in the front of the brain involved in motor control and executive functioning. The researchers then followed the ex-convicts for four years to see how they fared. Among the subjects of the study, men who had lower ACC activity during the quick-decision tasks were more likely to be arrested again after getting out of prison, even after the researchers accounted for other risk factors such as age, drug and alcohol abuse and psychopathic traits. Men who were in the lower half of the ACC activity ranking had a 2.6-fold higher rate of rearrest for all crimes and a 4.3-fold higher rate for nonviolent crimes. The results are published today in the Proceedings of the National Academy of Sciences1. © 2013 Nature Publishing Group

Keyword: Aggression; Brain imaging
Link ID: 17950 - Posted: 03.26.2013

By MARY ROACH WAGENINGEN, THE NETHERLANDS — When I told people I was traveling to Food Valley, I described it as the Silicon Valley of eating. At this cluster of universities and research facilities, nearly 15,000 scientists are dedicated to improving — or, depending on your sentiments about processed food, compromising — the quality of our meals. At the time I made the Silicon Valley comparison, I did not expect to be served actual silicone. But here I am, in the Restaurant of the Future, a cafeteria at Wageningen University where hidden cameras record diners as they make decisions about what to eat. And here it is, a bowl of rubbery white cubes the size of salad croutons. Andries van der Bilt has brought them from his lab in the brusquely named Department of Head and Neck, at the nearby University Medical Center Utrecht. “You chew them,” he said. The cubes are made of a trademarked product called Comfort Putty, more typically used in its unhardened form for taking dental impressions. Dr. Van der Bilt isn’t a dentist, however. He is an oral physiologist, and he likely knows more about chewing than anyone else in the world. He uses the cubes to quantify “masticatory performance” — how effectively a person chews. I take a cube from the bowl. If you ever, as a child, chewed on a whimsical pencil eraser in the shape of, say, an animal or a piece of fruit, then you have tasted this dish. “I’m sorry.” Dr. Van der Bilt winces. “It’s quite old.” As though fresh silicone might be better. © 2013 The New York Times Company

Keyword: Chemical Senses (Smell & Taste)
Link ID: 17949 - Posted: 03.26.2013

By Sandra G. Boodman, A year after her daughter’s stomach problems began, Margaret Kaplow began having pains of her own. When she sat down to dinner with her family, Kaplow’s gut would clench involuntarily as she waited to see if this was one of the nights Madeline would eat a few bites before putting down her fork, pushing away from the table and announcing, “I don’t feel good.” For nearly six years, Maddie Kaplow’s severe, recurrent abdominal pain, which began shortly before her 13th birthday, was attributed to a host of ailments. Specialists in the District, Maryland and Virginia decided at various times that she had a gluten intolerance, a ruptured ovarian cyst, a diseased appendix or irritable bowel syndrome (IBS). Some were convinced that her problem was psychological and that she was a high-strung teenaged girl seeking attention. “It was a freaking nightmare,” Kaplow recalled of those years. She said she never believed her daughter was exaggerating or faking her symptoms. And each time a new diagnosis was made, Kaplow said, she felt elated that a doctor had figured out the cause of Maddie’s pain, which would turn into crushing disappointment when it recurred. It was only after she landed in a college infirmary 400 miles from her Northern Virginia home that doctors finally determined what was wrong and treated Maddie for the illness that dominated her adolescence. © 1996-2013 The Washington Post

Keyword: Pain & Touch
Link ID: 17948 - Posted: 03.26.2013

By Susan Milius Hey evolution, thanks for nothing. When a mammal embryo develops, its middle ear appears to form in a pop-and-patch way that seals one end with substandard, infection-prone tissue. “The way evolution works doesn’t always create the most perfect, engineered structure,” says Abigail Tucker, a developmental biologist at King’s College London. “Definitely, it’s made an ear that’s slightly imperfect.” The mammalian middle ear catches sound and transfers it, using three tiny bones that jiggle against the eardrum, to the inner ear chamber. Those three bones — the hammer, anvil and stirrup — are a distinctive trait that distinguishes the group from other evolutionary lineages. Research in mouse embryos finds that the middle ear begins as a pouch of tissue. Then its lining ruptures at one end and the break lets in a different kind of tissue, which forms the tiny bones of the middle ear. This intruding tissue originates from what’s called the embryo’s neural crest, a population of cells that gives rise to bone and muscle. Neural crest tissue has never been known before to create a barrier in the body. Yet as the mouse middle ear forms, this tissue creates a swath of lining that patches the rupture, Tucker and colleague Hannah Thompson, report in the March 22 Science. © Society for Science & the Public 2000 - 2013

Keyword: Hearing; Development of the Brain
Link ID: 17947 - Posted: 03.25.2013

By JANE E. BRODY Noise, not age is the leading cause of hearing loss. Unless you take steps now to protect to your ears, sooner or later many of you — and your children — will have difficulty understanding even ordinary speech. Tens of millions of Americans, including 12 percent to 15 percent of school-age children, already have permanent hearing loss caused by the everyday noise that we take for granted as a fact of life. “The sad truth is that many of us are responsible for our own hearing loss,” writes Katherine Bouton in her new book, “Shouting Won’t Help: Why I — and 50 Million Other Americans — Can’t Hear You.” The cause, she explains, is “the noise we blithely subject ourselves to day after day.” While there are myriad regulations to protect people who work in noisy environments, there are relatively few governing repeated exposure to noise outside the workplace, from portable music devices, rock concerts, hair dryers, sirens, lawn mowers, leaf blowers, vacuum cleaners, car alarms and countless other sources. We live in a noisy world, and every year it seems to get noisier. Ms. Bouton notes that the noise level inside Allen Fieldhouse at the University of Kansas often exceeds that of a chain saw. After poor service, noise is the second leading complaint about restaurants. Proprietors believe that people spend more on food and drink in bustling eateries, and many have created new venues or retrofitted old ones to maximize sound levels. Copyright 2013 The New York Times Company

Keyword: Hearing
Link ID: 17946 - Posted: 03.25.2013

A lack of a protein in Down's syndrome brains could be the cause of learning and memory problems, says a US study. Writing in Nature Medicine, Californian researchers found that the extra copy of chromosome 21 in people with the condition triggered the protein loss. Their study found restoring the protein in Down's syndrome mice improved cognitive function and behaviour. The Down's Syndrome Association said the study was interesting but the causes of Down's were very complex. Prof Huaxi Xu, senior author of the study from the Sanford-Burnham Medical Research Institute, said that in experiments on mice they discovered that the SNX27 protein was important for brain function and memory formation. Mice with less SNX27 had fewer active glutamate receptors and therefore had impaired learning and memory. The SNX27-deficient mice shared some characteristics with Down's syndrome, so the researchers looked at human brains with the condition. This confirmed their findings in the lab - that people with Down's syndrome also have significantly lower levels of SNX27. BBC © 2013

Keyword: Development of the Brain; Genes & Behavior
Link ID: 17945 - Posted: 03.25.2013

Two years after New Brunswick decided to help multiple sclerosis patients pay for an unproven treatment that's only offered outside the country, the number of patients who have sought the so-called liberation treatment has fallen short of expectations. A leading authority on MS says he's not surprised the numbers are falling off. The Finance Department says since April 1, 2011, 82 people who wanted the treatment that widens constricted veins in the neck have been approved for payments of $2,500 each. Applicants get the government funding if a community group raises matching funds. The provincial government budgeted $400,000 for the program in its first two years of operation — or enough to help 160 people seek the treatment. The government approved 25 applications in the first four months the money was available, but interest has tapered off and there have been no applications in the last two months. “It's getting fewer and fewer because every month a negative study is coming out," said Dr. Jock Murray, a neurologist at Dalhousie University in Halifax. Italian vascular specialist Paolo Zamboni reported dramatic improvements in his patients after he pioneered the procedure, but Murray said none of the subsequent studies done around the world have had the same results. “Every study has tended to be negative," he said. © CBC 2013

Keyword: Multiple Sclerosis
Link ID: 17944 - Posted: 03.25.2013

By John Horgan Does anyone still remember “The Decade of the Brain“? Youngsters don’t, but perhaps some of my fellow creaky, cranky science-lovers do. In 1990, the brash, fast-growing Society for Neuroscience convinced Congress to name the ’90s the Decade of the Brain. The goal, as President George Bush put it, was to boost public awareness of and support for research on the “three-pound mass of interwoven nerve cells” that serves as “the seat of human intelligence, interpreter of senses and controller of movement.” One opponent of this public-relations stunt was Torsten Wiesel, who won a Nobel Prize in 1981 for work on the neural basis of vision. When I interviewed him in 1998 for my book The Undiscovered Mind, he grumbled that the Decade of the Brain was “foolish.” Scientists “need at least a century, maybe even a millennium,” to understand the brain, Wiesel said. “We are at the very beginning of brain science.” I recalled Wiesel’s irritable comments as I read about big new neuroscience initiatives in the U.S. and Europe. In January, the European Union announced it would sink more than $1 billion over the next decade into the Human Brain Project, an attempt to construct a massive computer simulation of the brain. The project, according to The New York Times, involves more than 150 institutions. Meanwhile, President Barack Obama is reportedly planning to commit more than $3 billion to a similar project, called the Brain Activity Map. © 2013 Scientific American

Keyword: Brain imaging
Link ID: 17943 - Posted: 03.25.2013

By Brian Palmer, As a columnist who tries to explain scientific and other puzzles, I get asked a lot of strange questions. Here’s one that has been bugging me for some time: Are there visually impaired animals? Are there nearsighted deer that could use glasses or farsighted elephants that could benefit from an enormous set of contacts? How about astigmatic alligators? It seems like an animal question, but, at its core, it’s motivated by an astute comparison with humans. We’re undeniably visual creatures, yet many of us have trouble seeing well. According to some estimates, up to 42 percent of Americans are myopic, or nearsighted. Isn’t this a failure of natural selection? Shouldn’t our blurry-sighted ancestors have starved to death or been consumed by predators because of their visual handicaps? Does nature allow other animals to have such poor vision? These questions turn out to be surprisingly complicated. Let’s start out with the non-human animals and work back to our own visual shortcomings. Ophthalmologists can’t ask lions to read an eye chart or put glasses on a whale. Instead, they shine a light into the animal’s eye to see how it refracts and focuses on the retina. And with a trainable animal, such as a hawk or a horse, researchers can teach it to respond to a visual cue, then determine how well the animal picks up the cue when it is far away, very close or somehow obscured. © 1996-2013 The Washington Post

Keyword: Vision
Link ID: 17942 - Posted: 03.25.2013

Michael Corballis, professor of cognitive neuroscience and psychology at the University of Auckland in New Zealand, responds: Although teaching people to become ambidextrous has been popular for centuries, this practice does not appear to improve brain function, and it may even harm our neural development. Calls for ambidexterity were especially prominent in the late 19th and early 20th centuries. For instance, in the early 20th century English propagandist John Jackson established the Ambidextral Culture Society in pursuit of universal ambidexterity and “two-brainedness” for the betterment of society. This hype died down in the mid-20th century as benefits of being ambidextrous failed to materialize. Given that handedness is apparent early in life and the vast majority of people are right-handed, we are almost certainly dextral by nature. Recent evidence even associated being ambidextrous from birth with developmental problems, including reading disability and stuttering. A study of 11-year-olds in England showed that those who are naturally ambidextrous are slightly more prone to academic difficulties than either left- or right-handers. Research in Sweden found ambidextrous children to be at a greater risk for developmental conditions such as attention-deficit hyperactivity disorder. Another study, which my colleagues and I conducted, revealed that ambidextrous children and adults both performed worse than left- or right-handers on a range of skills, especially in math, memory retrieval and logical reasoning. © 2013 Scientific American

Keyword: Laterality; Learning & Memory
Link ID: 17941 - Posted: 03.25.2013

Philip Ball No one with even a passing interest in scientific trends will have failed to notice that the brain is the next big thing. It has been said for at least a decade, but now it’s getting serious — with, for example, the recent award by the European Commission of €500 million (US$646 million) to the Human Brain Project to build a new “infrastructure for future neuroscience” and a $1-billion initiative endorsed by President Obama. Having failed to ‘find ourselves’ in our genome, we’re starting a search in the grey matter. It’s a reasonable objective, but only if we have a clear idea of what we hope and expect to find. Some neuroscientists have grand visions, such as that adduced by Semir Zeki of University College London: “It is only by understanding the neural laws that dictate human activity in all spheres — in law, morality, religion and even economics and politics, no less than in art — that we can ever hope to achieve a more proper understanding of the nature of man.” Zeki heads the UCL Institute of Neuroesthetics. This is one of many fields that attaches ‘neuro’ to some human trait with the implication that the techniques of neuroscience, such as functional magnetic resonance imaging, will explain it. We have neurotheology, neuroethics, neurocriminology and so on. Meanwhile, in popular media, a rash of books and articles proclaim (in a profoundly ugly trope) that “this is your brain on drugs/music/religion/sport”. It seems unlikely that studies of the brain will ever be able to wholly explain how we respond to art. © 2013 Nature Publishing Group

Keyword: Emotions; Vision
Link ID: 17940 - Posted: 03.23.2013