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By PAGAN KENNEDY “Fingers!” Gerwin Schalk sputtered, waving his hands around in the air. “Fingers are made to pick up a hammer.” He prodded the table, mimicking the way we poke at computer keyboards. “It’s totally ridiculous,” he said. I was visiting Schalk, a 40-year-old computer engineer, at his bunkerlike office in the Wadsworth Center, a public-health lab outside Albany that handles many of New York State’s rabies tests. It so happens that his lab is also pioneering a new way to control our computers — with thoughts instead of fingers. Schalk studies people at the Albany Medical Center who have become, not by choice, some of the world’s first cyborgs. One volunteer was a young man in his 20s who suffers from a severe form of epilepsy. He had been outfitted with a temporary device, a postcard-size patch of electrodes that sits on the brain’s cortex, known as an electrocorticographic (ECoG) implant. Surgeons use these implants to home in on the damaged tissue that causes seizures. Schalk took advantage of the implant to see if the patient could control the actions in a video game called Galaga using only his thoughts. In the videotape of this experiment, you see a young man wearing a turban of bandages with wires running from his head to a computer in a cart. “Pew, pew,” the ship on the computer screen whines, as it decimates buglike creatures. The patient flicks the spaceship back and forth by imagining that he is moving his tongue. This creates a pulse in his brain that travels through the wires into a computer. Thus, a thought becomes a software command. © 2011 The New York Times Company
Keyword: Robotics
Link ID: 15807 - Posted: 09.17.2011
by Bob Holmes THE two men in the hospital ward had both hit their heads in car accidents, but that was where the similarities ended. One would spend weeks unconscious in critical care, near to death. The other had only a mild concussion; he never lost consciousness, but somehow didn't feel quite right. Yet months later their roles were reversed. "The one with the severe injury is almost back to normal function," says Douglas Smith, director of the Center for Brain Injury Repair at the University of Pennsylvania in Philadelphia, "and the one with concussion can't go back to work, probably ever." Smith's two patients illustrate one of the frustrating paradoxes of head injuries: even seemingly mild impacts can have devastating long-term consequences. And we have no way of predicting who will fully recover and who will have lingering problems. Concussion, or mild traumatic brain injury as doctors call it, has long been seen as a benign and temporary affliction. But over the past decade there has been growing realisation that longer-term symptoms can affect between 10 and 15 per cent of those diagnosed with it. These range from fuzzy thinking and memory lapses to, for the most unfortunate, serious neurological conditions such as premature Alzheimer's disease. In fact, concussion is thought to be the single biggest environmental cause of Alzheimer's. Even a mild impact can double the risk of developing early dementia, according to a massive study of older military veterans in the US, which was presented at the Alzheimer's Association International Conference in July (bit.ly/pDhlHJ). In that, the risk jumped from 7 to 15 per cent. © Copyright Reed Business Information Ltd.
Keyword: Brain Injury/Concussion
Link ID: 15806 - Posted: 09.15.2011
by Celeste Biever HOW intelligent are you? I'd like to think I know how smart I am, but the test in front of me is making me reconsider. On my computer screen, a puzzling row of boxes appears: some contain odd-looking symbols, while others are empty. I click on one of the boxes. A red sign indicates I made an error. Dammit. I concentrate, and try again. Yes, a green reward! Despite this small success, I am finding it tough to make sense of what's going on: this is unlike any exam I've ever done. Perhaps it's not surprising that it feels unfamiliar - it's not your average IQ test. I am taking part in the early stages of an effort to develop the first "universal" intelligence test. While traditional IQ and psychometric tests are designed to home in on differences between people, a universal test would rank humans, robots, chimps and perhaps even aliens on a single scale - using a mathematically derived definition of intelligence, rather than one tainted by human bias. What's the point? The idea for a universal test has emerged from the study of artificial intelligence and a desire for better ways to measure it. Next year, the most famous test for gauging the smarts of machines will be widely celebrated on the 100th anniversary of the birth of Alan Turing, its creator. The Turing test is, however, flawed. To pass it, a machine has to fool a human judge into believing he or she is conversing with another person. But exactly how much smarter are you than the cleverest robot? The test cannot tell you. It also cannot measure intelligence greater than a human's. Machines are getting smarter - possibly smarter than us, soon - so we need a much better way to gauge just how clever they are. © Copyright Reed Business Information Ltd.
Keyword: Intelligence; Evolution
Link ID: 15805 - Posted: 09.15.2011
By Laura Sanders Researchers have found a new way to make a temporary chink in the brain’s armor, opening the door for treatments to get in. The results of a rodent study, published September 14 in the Journal of Neuroscience, may highlight a method to sneak therapies for diseases such as Alzheimer’s, HIV and cancer past the blood-brain barrier. “It’s a very interesting development,” says Celia Brosnan of the Albert Einstein College of Medicine in the Bronx, N.Y. “It has considerable potential, but obviously there’s a lot that needs to be followed up on.” Many potentially useful compounds exist to treat neurological diseases, notes study coauthor Margaret Bynoe of Cornell University College of Veterinary Medicine in Ithaca, N.Y. “The problem is getting them into the brain,” she says, where walls of specialized cells line blood vessels and keep harmful substances out. Since this barrier also impedes drugs, researchers have been eager to find a safe and effective way to get past it. In the new study, Bynoe and colleagues targeted molecules that sit on the surface of blood-brain barrier cells. Using a compound called NECA to activate these molecules, called adenosine receptors, in mice caused the barrier to open for up to 18 hours, the team found. After this activation, bulky sugar molecules introduced by the researchers, along with giant antibodies engineered to scoop up the Alzheimer’s-related protein amyloid-beta, crossed from the blood into the brain. © Society for Science & the Public 2000 - 2011
Keyword: Drug Abuse
Link ID: 15804 - Posted: 09.15.2011
By JAMES GORMAN Laughter is regularly promoted as a source of health and well being, but it has been hard to pin down exactly why laughing until it hurts feels so good. The answer, reports Robin Dunbar, an evolutionary psychologist at Oxford, is not the intellectual pleasure of cerebral humor, but the physical act of laughing. The simple muscular exertions involved in producing the familiar ha, ha, ha, he said, trigger an increase in endorphins, the brain chemicals known for their feel-good effect. His results build on a long history of scientific attempts to understand a deceptively simple and universal behavior. “Laughter is very weird stuff, actually,” Dr. Dunbar said. “That’s why we got interested in it.” And the findings fit well with a growing sense that laughter contributes to group bonding and may have been important in the evolution of highly social humans. Social laughter, Dr. Dunbar suggests, relaxed and contagious, is “grooming at a distance,” an activity that fosters closeness in a group the way one-on-one grooming, patting and delousing promote and maintain bonds between individual primates of all sorts. In five sets of studies in the laboratory and one field study at comedy performances, Dr. Dunbar and colleagues tested resistance to pain both before and after bouts of social laughter. The pain came from a freezing wine sleeve slipped over a forearm, an ever tightening blood pressure cuff or an excruciating ski exercise. The findings, published in the Proceedings of the Royal Society B: Biological Sciences, eliminated the possibility that the pain resistance measured was the result of a general sense of well being rather than actual laughter. And, Dr. Dunbar said, they also provided a partial answer to the ageless conundrum of whether we laugh because we feel giddy or feel giddy because we laugh. © 2011 The New York Times Company
Keyword: Pain & Touch; Emotions
Link ID: 15803 - Posted: 09.15.2011
By Nicholas Luther A study by a team of UC Berkeley neuroscientists has uncovered new cerebral mechanisms behind tinnitus, a currently incurable condition that produces a constant ringing or buzzing sound in the ear in the absence of other noise. The study, published Sept. 6 in the journal Proceedings of the National Academy of Sciences, provides an alternative hypothesis to the prevailing view that tinnitus is associated with neurons in the region of the cortex that is affected by hearing loss. The research, which was conducted by the UC Berkeley Helen Wills Neuroscience Institute, shows that the higher-frequency neurons in the area of the cortex affected by hearing loss are responsible for the high-pitched noise characteristic of tinnitus. According to Shaowen Bao, co-author of the study and adjunct assistant professor of neuroscience at UC Berkeley, this study is the first to attribute tinnitus to the sensory-deprived region — which is affected by hearing loss — of the cortex. “Researchers have come up with the prevailing theory based on numerous studies and findings,” he said. “However, these findings are somewhat inconsistent. We hope we can get a more coherent idea of what’s happening.” According to the American Tinnitus Association, tinnitus affects more than 50 million Americans with varying degrees of severity ranging from barely noticeable to debilitating. Although scientists have yet to identify a cure for the condition, popular treatment options include masking the tinnitus noise with music, which provides temporary relief, and training the neurons in the auditory cortex to enhance their response to lost frequencies, which helps to gradually reconnect the ear to the sensory-deprived neurons. © Copyright 2011 The Daily Californian
Keyword: Hearing
Link ID: 15802 - Posted: 09.15.2011
By Charles Q. Choi Near-death experiences are often thought of as mystical phenomena, but research is now revealing scientific explanations for virtually all of their common features. The details of what happens in near-death experiences are now known widely—a sense of being dead, a feeling that one's "soul" has left the body, a voyage toward a bright light, and a departure to another reality where love and bliss are all-encompassing. Approximately 3 percent of the U.S. population says they have had a near-death experience, according to a Gallup poll. Near-death experiences are reported across cultures, with written records of them dating back to ancient Greece. Not all of these experiences actually coincide with brushes with death—one study of 58 patients who recounted near-death experiences found 30 were not actually in danger of dying, although most of them thought they were. Recently, a host of studies has revealed potential underpinnings for all the elements of such experiences. "Many of the phenomena associated with near-death experiences can be biologically explained," says neuroscientist Dean Mobbs, at the University of Cambridge's Medical Research Council Cognition and Brain Sciences Unit. Mobbs and Caroline Watt at the University of Edinburgh detailed this research online August 17 in Trends in Cognitive Sciences. For instance, the feeling of being dead is not limited to near-death experiences—patients with Cotard or "walking corpse" syndrome hold the delusional belief that they are deceased. © 2011 Scientific American,
Keyword: Vision; Attention
Link ID: 15801 - Posted: 09.15.2011
By PERRI KLASS, M.D. What makes a child nap? Most parents cherish toddlers’ naps as moments of respite and recharging, for parent and child alike; we are all familiar with the increased crankiness that comes when a nap is unduly delayed or evaded. But napping behavior has been somewhat taken for granted, even by sleep scientists, and napping problems have often been treated by pediatricians as parents’ “limit-setting” problems. Now, researchers are learning that it is not so simple: napping in children actually is a complex behavior, a mix of individual biology, including neurologic and hormonal development, cultural expectations and family dynamics. What parents usually want to know is simply how long a child should nap. That concern dates back a little over a hundred years: In the first decade of the 20th century, European experts published the original studies measuring the sleep patterns of children and promptly began worrying they were not getting enough sleep. Today, researchers believe that very young children take naps because so-called sleep pressure builds rapidly in their brains — that is, the need for sleep accumulates so quickly during waking hours that a nap becomes a biological necessity. It is not just a question of how much total sleep that children need in 24 hours. Possibly because of the intense synaptic activity that goes on in their highly active, highly connected brains, young children are less able to tolerate long periods of time awake. In the early 1980s, Dr. Alexander A. Borbély, a professor of pharmacology at the University of Zurich, Switzerland, posited a “two-process model of sleep regulation.” © 2011 The New York Times Company
Keyword: Sleep; Development of the Brain
Link ID: 15800 - Posted: 09.13.2011
By SINDYA N. BHANOO When male hummingbirds perform valiant dives in front of females, they are actually enticing them with high-frequency vibrations produced by their tail feathers, a new study reports. The vibrations are audible, precise and separate from the humming of the wings that gives the birds their name. Females may be making use of these vibrations to select mates, said the study’s lead author, Christopher Clark, an expert on biomechanics at Yale. Dr. Clark and his colleagues from Yale and the University of California, Berkeley, report their findings in the current issue of the journal Science. “The sounds of each species are fairly distinctive and fairly unique,” he said. “It clearly evolved as a communication signal.” The researchers studied 31 tail feathers from 14 species of hummingbirds. They placed the feathers in a wind tunnel and used a Doppler vibrometer to measure the vibrations. A light breeze produced no vibrations. But a higher velocity, simulating the wind speed generated when male birds are diving, touched off the sounds. The researchers learned that feathers of different shapes and sizes resulted in different frequencies with different harmonic structures. © 2011 The New York Times Company
Keyword: Sexual Behavior; Hearing
Link ID: 15799 - Posted: 09.13.2011
By ANTHONY DePALMA WEST POINT, N.Y. — The cartoon-purple boxes are hard to miss. The foresters who hang them from roadside trees all over the country call them Barney traps, for the friendly dinosaur whose color they resemble, but their purpose is anything but gentle. The three-sided contraptions, baited with a chemical lure and coated with glue, are designed to catch the attention of the emerald ash borer — a deceptively pretty little beetle from Asia that has killed tens of millions of ash trees in less than a decade. “Right now, the emerald ash borer is the most destructive insect we have in North America,” said Nathan Siegert, an entomologist with the United States Forest Service. Named for its wing covers, which look so much like emeralds that people in some countries string them into jewelry, the borer is thought to have come to North America in wooden pallets from China. Since they were discovered near Detroit in 2002, the beetles have spread to 15 states and Ontario. The ash is a commercially valuable tree whose straight trunk and true grain make its wood perfect for furniture legs, baseball bats and other products. It also makes great firewood, and foresters say the beetles’ rapid advancement has been aided by campers who unknowingly carry the infested wood, moving the beetles farther and faster than they could fly on their own. © 2011 The New York Times Company
Keyword: Vision
Link ID: 15798 - Posted: 09.13.2011
Four-year-olds who watched nine minutes of the fast-paced cartoon SpongeBob Squarepants showed temporary attention and learning problems, researchers found. The study compared 60 children who were randomly assigned to watch SpongeBob, the slower-paced PBS cartoon Caillou or to draw pictures as a control. After nine minutes, the children did four tests to tap their "executive function" — such as attention, problem-solving and delay of gratification — which allows people to set goals and implement them. Executive function is important for helping children to learn and function in school and be creative, the researchers said. "Just nine minutes of viewing a fast-paced television cartoon had immediate negative effects on four-year-olds’ executive function," Angeline Lillard and Jennifer Peterson of the psychology department at the University of Virginia concluded in Monday's issue of the journal Pediatrics. "Parents should be aware that fast-paced television shows could at least temporarily impair young children’s executive function." In the fast-paced show, the scenes changed, for example, from a swimming pool to a bedroom, every 11 seconds on average compared with every 34 seconds on average in the educational TV show, the researchers said. The children also watched for nine minutes, while many cartoons last 11 minutes. Two such episodes are often shown in a 30-minute programming slot, Lillard and Peterson noted in suggesting that watching a full fast-paced program could be more harmful. © CBC 2011
Keyword: Attention
Link ID: 15797 - Posted: 09.13.2011
By JANE E. BRODY If you have gained a lot of unwanted pounds at any time during the last 30-odd years, you may be relieved to know that you are probably not to blame. At least not entirely. Many environmental forces, from economic interests of the food and beverage industries to the way our cities and towns are built, have conspired to subvert the body’s natural ability to match calories in with calories out. And the solution to the nation’s most pressing health problem — the ever-rising epidemic of overweight and obesity at all ages — lies in the answer to this question: Why did this happen in the first place? That is the conclusion of an impressive team of experts who spent the last two years examining obesity-promoting forces globally. They recently published their findings online in a series of reports in The Lancet. But as has happened with smoking, it will take many years, a slew of different tactics and the political will to overcome powerful lobbying by culpable industries to turn the problem around and begin to bring the prevalence of overweight and obesity back to the levels of the 1970s. When I was growing up in the 1940s and ’50s, I had to walk or bike many blocks to buy an ice cream cone. There were no vending machines dispensing candy and soda, and no fast-food emporiums or shopping malls with food courts. Nor were we constantly bombarded with televised commercials for prepared foods and drinks laden with calories of fats and sugars. © 2011 The New York Times Company
Keyword: Obesity
Link ID: 15796 - Posted: 09.13.2011
by Elizabeth Norton Humans are probably the only species on Earth who nurture their young for 20 years or more. For men in particular, the intensive demands of parenting can come as such a shock that a built-in biological mechanism has evolved to help cope with the change. A new study shows that becoming a father leads to a sharp decline in testosterone, suggesting that although high levels of the hormone may help men win a mate, testosterone-fueled traits such as aggression and competition are less useful when it comes to raising children. Previous research had shown that among new fathers, testosterone levels were lower than in men of the same age who didn't have children. But no study addressed whether parenthood itself was responsible, or whether men who became committed partners and fathers started out with lower levels of the hormone than did their single, footloose friends. To sort out cause and effect, anthropologists Lee Gettler, Christopher Kuzawa, and colleagues at Northwestern University in Evanston, Illinois, and the University of San Carlos in Cebu City, Philippines, checked testosterone levels in a group of men participating in the ongoing Cebu Longitudinal Health and Nutrition Survey. The survey began with a group of some 3000 women who were pregnant in 1983 and followed the general health, nutrition, medical care, and survival of their children; it has since expanded into an intergenerational study of health, education, and sexual behavior as those children grew up and are now having children of their own. © 2010 American Association for the Advancement of Science.
Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 15795 - Posted: 09.13.2011
By GINA KOLATA A small pilot study has found preliminary evidence that squirting insulin deep into the nose where it travels to the brain might hold early Alzheimer’s disease at bay, researchers said on Monday. It comes at a time when there are no effective ways to prevent or delay the progress of Alzheimer’s. And although the results are preliminary and must be viewed with caution, “it is a provocative study,” said Dr. Jason Karlawish, an Alzheimer’s researcher and ethicist at the University of Pennsylvania. But he and other experts caution that a bigger and longer study is needed to see if the initial results hold up and whether there are adverse effects that might negate any benefits. “It’s important readers realize this is a pilot trial,” said Dr. P. Murali Doraiswamy, an Alzheimer’s researcher at Duke University who was not part of the study. “It’s not ready for prime time.” The study, published online in the Archives of Neurology, included 104 people, a group small enough that the promising results could have occurred by chance. Researchers at the University of Washington divided the subjects into three groups. One got a placebo, one got 20 international units of aerosolized insulin a day, and the third got 40 international units a day. In the four-month study, the group randomly assigned to receive intranasal insulin twice a day either improved slightly or remained the same in tests of memory and assessments of their ability to handle day-to-day activities. The lower dose seemed more effective than the higher one. Those who received placebos got worse. © 2011 The New York Times Company
Keyword: Alzheimers
Link ID: 15794 - Posted: 09.13.2011
Glioma, one of the most deadly and common types of brain tumor, is often associated with seizures, but the origins of these seizures and effective treatments for them have been elusive. Now a team funded by the National Institutes of Health has found that human gliomas implanted in mice release excess levels of the brain chemical glutamate, overstimulating neurons near the tumor and triggering seizures. The researchers also found that sulfasalazine, a drug on the market for treating certain inflammatory disorders, can reduce seizures in mice with glioma. About 80 percent of people with glioma will experience at least one seizure during their illness, often as the first symptom. About one-third of patients will develop recurring seizures, known as tumor-associated epilepsy. Sen. Ted Kennedy, D-Mass., whose death was caused by a malignant glioma in August 2009, was diagnosed after having a seizure 15 months earlier. "Seizures are a frequent symptom of glioma and are often poorly controlled by epilepsy medications," said Jane Fountain, Ph.D., a program director at NIH's National Institute of Neurological Disorders and Stroke (NINDS). "Understanding why the seizures occur and how to counteract them could help us substantially improve the quality of life for people with glioma." "People have assumed that tumors cause seizures by irritating the brain, but that really isn't a scientific explanation. We have now shown that the seizures are caused by glutamate release from the tumor," said Harald Sontheimer, Ph.D., a professor of neurobiology and director of the Center for Glial Biology in Medicine at the University of Alabama Birmingham (UAB). Dr. Sontheimer and his team published their results in Nature Medicine.
Keyword: Epilepsy
Link ID: 15793 - Posted: 09.13.2011
By Lauren Ware In a clear Plexiglas laboratory cage, a mouse sleeps. A thin fiber optic cable projects upward from the top of its head and out through the cage’s lid. The cable lights with a pulse of blue light. The mouse continues to sleep; the light continues to pulse. After a few more pulses, the mouse wakes up. It rubs its face, stretches its legs and runs over to its food cup and begins to eat voraciously, as though it were starving. It keeps eating as the blue light pulses. The optical fiber that carries the blue light goes directly into the mouse’s brain. It targets a specific group of brain cells that have been modified to react to light. The experiment uses a technique called optogenetics, developed seven years ago, which can selectively activate or silence groups of nerve cells, or neurons, in real time. And it allows scientists to interact with the brain and begin to map how it works with a degree of detail that was previously unimaginable. That’s what Scott Sternson has done with the apparently starving mouse at Janelia Farm in Ashburn, Va., an interdisciplinary biomedical research center that is part of the Howard Hughes Medical Institute. In fact, this mouse was well fed and should not have been hungry. Sternson’s research group targeted a type of cell called the agouti-related peptide (AGRP) neuron. AGRP cells live in the hypothalamus and have been linked to feeding behavior in other studies. The scientists used a virus to insert the DNA of a light-sensitive protein from bacteria, channelrhodopsin-2, into the AGRP neurons. Some of the AGRP neurons take up the DNA and begin to produce the protein and send it to the cell membrane. When the blue light is flashed into the mouse’s brain via the optical fiber, the protein causes the neurons to move ions across the cell membrane, effectively stimulating them to fire an electrical signal, the action potential, which neurons use to communicate with each other. Sternson found that the more AGRP neurons are stimulated, the more the mouse eats. And as soon as the light stops, so does the feeding. Miller-McCune © 2011
Keyword: Genes & Behavior
Link ID: 15792 - Posted: 09.13.2011
By Victoria Gill Science reporter, BBC Nature Big brown bats learn to hunt by eavesdropping on the sonar of other bats, according to researchers. A team from the University of Maryland, US, tracked bats as they flew around a room hunting for a mealworm suspended from the ceiling. Young bats that flew with "experienced" bats - that had been trained to find the worm - were quickly able to find the treat alone. The results are published in the journal Animal Behaviour. They are the first to show that the bats (Eptesicus fuscus) actively attend to the sonar of others in order to learn from them. This social learning is important to many mammals, but it had not been clearly demonstrated in bats. Genevieve Spanjer Wright, a graduate student from the University of Maryland led the research. She and her colleagues trained 12 "demonstrator bats" to catch a mealworm suspended from the ceiling by a string. By repeatedly changing the location of the food item, the researchers trained the bats to actively hunt for it using their sonar or echolocation pulses. BBC © 2011
Keyword: Hearing; Development of the Brain
Link ID: 15791 - Posted: 09.12.2011
By Katherine Harmon Just watching television footage of the terrorist attacks of September 11, 2001, was enough to cause clinically diagnosable stress responses in some people who did not even live near the attacks—let alone the millions of people who did. Like many other major disasters, 9/11 brought with it a host of psychological repercussions, one of the most severe of which has been post-traumatic stress disorder. PTSD is characterized by trouble sleeping, difficulty controlling anger, losing interest in activities, flashbacks, emotional numbness and/or other symptoms. If not treated, it can be debilitating. But these reactions are not uncommon after a major disaster—and teasing apart post-9/11 disorders has been tricky for psychologists and researchers. "We tend to use the terminology of PTSD very loosely. A lot of people will have traumatic reactions but not necessarily PTSD," says Priscilla Dass-Brailsford of Georgetown University Medical Center's psychiatry department. Researchers have been poring over the piecemeal collection of studies conducted over the past decade on the conditions of people after the attacks—how they felt and how well various treatments, and the passage of time, have helped them overcome mental afflictions. And from the literature, we are learning that old styles of early intervention, such as debriefing sessions, are not as effective as once thought—and that more often than not, people are incredibly resilient and can recover on their own and should be given the opportunity to do so. © 2011 Scientific American,
Keyword: Stress
Link ID: 15790 - Posted: 09.12.2011
Zoë Corbyn Scientists have developed a miniature fluorescence microscope small enough to implant in the head of a living mouse and gather images from its brain without hindering its movement. The 1.9-gram, 2.4-cubic-centimetre device is described today in Nature Methods1. The device has already yielded results. The authors, led by applied physicist Mark Schnitzer and electrical engineer Abbas El Gamal of Stanford University in Stanford, California, report findings regarding both the dilation of capillaries in mouse brains and the firing of motor-activity-related Purkinje neurons, as well as some potential in vitro applications for the device, such as counting cells or spotting bacteria in samples. With a maximum resolution of 2.5 microns, the microscope is not as powerful as conventional bench-top models, which have resolutions as fine as 0.5 microns. But it does have a "very good" field of view which is larger than some bench-top models, notes Schnitzer. "For neuroscientists, [this method] is going to enable some experiments that we couldn't do before – indeed it already has", he says. Schnitzer and three of his colleagues have already founded a company, called Inscopix, in hopes of capitalizing on their device. While miniature versions of fluorescence microscopes have been produced before, including one by the Stanford group in 2008 that was lighter, none have been self contained or made using mass produced components. This microscope "contains all the optical parts within a single, small and easily-transportable housing, and we use mass-fabricated components, which opens up the possibility of mass-producing the entire microscope," says Schnitzer. © 2011 Nature Publishing Group,
Keyword: Brain imaging
Link ID: 15789 - Posted: 09.12.2011
By Matt McGrath Science reporter, BBC World Service Scientists have discovered that female chickens have a remarkable ability to choose the father of their eggs. Wily hens have evolved the ability to eject the sperm of unsuitable mates say researchers working with Swedish birds. Promiscuous roosters try to ensure that their genes are passed on by mating with as many females as possible. But by removing the genetic material of males they consider socially inferior, the hens have managed to retain control of paternity. Many species ranging from zebras to insects use the strategy of sperm ejection - but the evolutionary ideas behind it are often uncertain. Among birds, male Dunnocks force females to eject the sperm of other suitors in order to protect their own genes. But this research indicates that among chickens, the battle of the sexes seems to be all about female empowerment. Working with feral fowl in Sweden, the scientists found that many matings were forced, as the roosters are twice the size of the hens. To cope with the unwanted attention, females have evolved the ability to remove the ejaculate of those males they consider undesirable. BBC © 2011
Keyword: Sexual Behavior; Evolution
Link ID: 15788 - Posted: 09.12.2011