By Emily Harrison For all the delights and horrors human vision provides, it has only one way of collecting information about life: cells in the retina register photons of light for the brain to interpret into images. When it comes to seeing structures too small for the eye to resolve, ones that reflect too few photons for the eye to detect, microscopy must lead the way. The images displayed here, honored in the 2007 Olympus BioScapes Digital Imaging Competition for both their technical merit and their aesthetics, represent the state of the art in light micro­scopy for biological research. Call it a renaissance, call it a revolution; in the field of light microscopy, it is well under way. Palettes of light are diversifying as scientists develop new fluorescent markers and new genetic techniques for incorporating them into samples, throwing open doors to discovery. For example, the researchers responsible for this year’s first-prize image employed a new technique, called Brainbow, to turn each neuron in a mouse’s brain a distinct color under the microscope. The method allows them to trace individual axons through a dizzying neuronal mesh and to map the wiring of the brain in a way that was impossible using earlier imaging techniques. The precision of the tools is changing, too. Individual proteins can be tagged to watch how a molecule walks, and the minute details of cell division and differentiation can be witnessed live. Microscopists can paint fast in broad strokes of light to capture ephemeral events or more slowly in tiny strokes of light to see a piece of life in exquisite detail. © 1996-2007 Scientific American Inc.

Keyword: Brain imaging
Link ID: 11030 - Posted: 06.24.2010

An experimental drug shows promise for people at high risk of advanced age-related macular degeneration, a condition that causes vision loss in older people, researchers say. Japanese and Harvard researchers found that endostatin significantly reduced or completely halted the abnormal growth of blood vessels within the eyes in tests on mice. Advanced age-related macular degeneration is an age-related, degenerative disease of the macula, a small area at the centre of the retina. The overgrowth of blood vessels into the retina can lead to central vision loss, preventing sufferers from seeing fine details. It can also lead to blindness. Researchers separated mice into two groups — one group of normal mice naturally produced endostatin, a protein in collagen, while the other group had endostatin removed in lab experiments. Using lasers, researchers induced new blood vessel growth in the edge of the retinas of all the mice, simulating age-related macular degeneration. The mice that had had the endostatin removed were three times as likely to develop the degenerative eye disease. © CBC 2007

Keyword: Vision
Link ID: 11029 - Posted: 06.24.2010

By Matt Kaplan What makes an ideal man? For some women, it's a charming personality; others just want to see a nice set of abs. Things aren't quite so complicated in the rest of the animal kingdom. In most species, every female prizes the same trait in a male, whether it be bright plumage or a pretty song. So researchers have been surprised to discover that female yellowthroats don't always agree on what turns them on--a finding that may offer a window onto speciation. Male yellowthroats sport large black masks and bright yellow bibs. Vibrant colors result from pigments called carotenoids, which are also antioxidants and thus a sign of health. So it was little surprise when biologist Corey Freeman-Gallant of Skidmore College in Saratoga Springs, New York, and colleagues found in 2001 that local female yellowthroats preferred males with the most vivid yellow bibs. But in the same year, biologist Peter Dunn of the University of Wisconsin, Milwaukee, published something different about his local population of yellowthroats: Females seemed to be targeting the size of males' black masks to determine whether they were worth a fling. That didn't make sense, because the black masks are generated from melanin, which has no connection to health. "I was taken aback," says Dunn. To confirm the findings, Dunn and colleagues brought yellowthroats from the New York state and the Wisconsin populations back to aviaries near Skidmore College. They spied on the females from behind a blind a few meters away as the birds were presented with multiple bachelors, some with big masks, some with bright yellow throats. Dunn measured the amount of time females spent ogling the various males and confirms in a future issue of the Journal of Avian Biology that both he and Freeman-Gallant were correct. New York state yellowthroats want males with large yellow bibs, and Wisconsin yellowthroats prefer males with big black masks. © 2007 American Association for the Advancement of Science.

Keyword: Sexual Behavior; Evolution
Link ID: 11028 - Posted: 06.24.2010

LONDON - It was once scientific heresy to suggest that smoking contributed to lung cancer. Now, another idea initially dismissed as nutty is gaining acceptance: the graveyard shift might increase your cancer risk. Next month, the International Agency for Research on Cancer, the cancer arm of the World Health Organization, will classify shift work as a "probable" carcinogen. That will put shift work in the same category as cancer-causing agents like anabolic steroids, ultraviolet radiation, and diesel engine exhaust. If the shift work theory proves correct, millions of people worldwide could be affected. Experts estimate that nearly 20 percent of the working population in developed countries work night shifts. It is a surprising twist for an idea that scientists first described as "wacky," said Richard Stevens, a cancer epidemiologist and professor at the University of Connecticut Health Center. In 1987, Stevens published a paper suggesting a link between light at night and breast cancer. Back then, he was trying to figure out why breast cancer incidence suddenly shot up starting in the 1930s in industrialized societies, where nighttime work was considered a hallmark of progress. Most scientists were bewildered by his proposal. Copyright 2007 The Associated Press.

Keyword: Biological Rhythms; Stress
Link ID: 11027 - Posted: 11.30.2007

By Diane F. Halpern, Camilla P. Benbow, David C. Geary, Ruben C. Gur, Janet Shibley Hyde and Morton Ann Gernsbacher For years, blue-ribbon panels of experts have sounded the alarm about a looming shortage of scientists, mathematicians and engineers in the U.S.—making dire predictions of damage to the national economy, threats to security and loss of status in the world. There also seemed to be an attractive solution: coax more women to these traditionally male fields. But there was not much public discussion about the reasons more women are not pursuing careers in these fields until 2005, when then Harvard University president Lawrence Summers offered his personal observations. He suggested to an audience at a small economics conference near Boston that one of the major reasons women are less likely than men to achieve at the highest levels of scientific work is because fewer females have “innate ability” in these fields. In the wake of reactions to Summers’s provocative statement, a national debate erupted over whether intrinsic differences between the sexes were responsible for the underrepresentation of women in mathematical and scientific disciplines. As a group of experts with diverse backgrounds in the area of sex differences, we welcome these ongoing discussions because they are drawing the public’s attention to this important issue. In this article, we present an analysis of the large body of research literature pertaining to the question of female participation in these fields, information that is central to understanding sex differences and any proposal designed to attract more women to the science and mathematics workforces. Contrary to the implications drawn from Summers’s remarks, there is no single or simple answer for why there are substantially fewer women than men in some areas of science and math. Instead a wide variety of factors that influence career choices can be identified, including cognitive sex differences, education, biological influences, stereotyping, discrimination and societal sex roles. © 1996-2007 Scientific American Inc.

Keyword: Sexual Behavior
Link ID: 11026 - Posted: 06.24.2010

By Faye Flam, Inquirer Staff Writer While some sex differences are still up for debate, one that's hard to argue away is men's greater fondness for pornography. Over the years I've heard men explain this in various ways. One of the most popular is that men are "more visual" than women, a convenient excuse for ogling at the beach. Is there any science behind this? "More visual" is too vague to investigate, but some studies have offered insight about why men consume most of the world's vast store of Internet porn. Neurobiologist and anthropologist Michael Platt of Duke University is studying differences in how the sexes respond to pictures in general. On average, his research shows, men will pay to see images of women. But you have to pay women to look at images of men! Platt started with similar studies in monkeys. While most animals are indifferent to photos even of individuals in their own species, monkeys and apes respond to pictures much as humans do. Rhesus macaques that Platt studied, for example, easily recognized the faces of familiar monkeys. And they liked some faces more than others, though the face wasn't always the favorite part.

Keyword: Sexual Behavior; Emotions
Link ID: 11025 - Posted: 11.30.2007

By Benjamin Lester Who says males are always the persistent sex? Female topi--a type of African antelope--become so intent on mating repeatedly with the most desirable partner that males sometimes have to fend off their aggressive advances to avoid running out of sperm, a researcher reports. The study is the first to suggest that sperm depletion causes such a role reversal in a mammal. Topi are "lek" breeders. For a month and a half each year, males congregate at a mating arena, or lek, to compete for barren patches of about 30 square meters. The biggest, fittest males, known as lek males, command plots in the center of the arena, and females, which come into heat for just 1 day per year, seek them out. These prized bulls mate as many as 36 times in just 30 minutes. A female copulates with about four males during her visit to the arena, usually mating with each male multiple times. Although they prefer lek males, nearly 75% of females also mate with less hunky males. The males keep this up for the entire rut, only occasionally nipping off for a bite to eat, says behavioral ecologist Jakob Bro-Jørgensen of the Institute of Zoology in London. Bro-Jørgensen studies topi in Kenya's Masai Mara National Reserve, and the sheer length of the rut interested him in the role that sperm depletion might play. In related species, he says, repeated mating can deplete sperm, meaning that with each additional ejaculation, the male is less likely to fertilize the female. © 2007 American Association for the Advancement of Science.

Keyword: Sexual Behavior; Evolution
Link ID: 11024 - Posted: 06.24.2010

Nora Schultz There is a cure for zombies after all – if you are a cockroach. A new study has shown that cockroaches that turned into zombies after being stung by a parasitic wasp can be revived with an antidote. Cockroaches can lose their ability to walk when stung by jewel wasps (Ampulex compressa) – the females of which use the cockroaches to feed their young. The wasp, being much smaller than the cockroach, has evolved a fine sting that can deliver a venom cocktail directly into the cockroach’s brain. The poisons effectively turn the cockroach into a zombie. The cockroach is not entirely paralysed, but loses its ability to escape. The wasp then grabs it by the antennae and pulls it into its burrow and lays an egg on its abdomen. The cockroach sits still while the wasp's larva hatches, chews a hole into its belly, and slowly eats its living host from the inside over a period of eight days. To find out if he could revive the cockroaches, Frederic Libersat from Ben-Gurion University in Be'er Sheva, Israel, injected stung zombie cockroaches with candidate chemicals that resembled various neurotransmitters in the brain. Journal reference: The Journal of Experimental Biology (vol 210, p 4411) © Copyright Reed Business Information Ltd.

Keyword: Neurotoxins
Link ID: 11023 - Posted: 06.24.2010

By Denise Winterman Modern life is too demanding to turn out the lights and we're more sleep deprived than ever before. How can we get back in the habit of grabbing shut-eye? Ask someone how they are and their response, more often than not, is "fine but a bit tired". Not surprising when one in three of us have sleep problems, according to recent research. The medical profession calls it tatt, short for "tired all the time". It's one of the most common complaints that doctors hear. The disappearance of rest from daily life is also one of the themes of a major new exhibition on sleep at the Wellcome Collection in London. We just aren't getting enough sleep and it's slipping down people's list of priorities. It seems modern life is just too demanding - and exciting - to switch off. As a result sleep deprivation is becoming a national problem, say experts. Sleep is so important because it allows the brain to recover from the rigours of the day. Not getting enough has been found to increase the risk of obesity, heart disease and depression. The government is keen to tackle these health issues, efforts doomed to failure unless getting enough sleep is made a priority as well. (C)BBC

Keyword: Sleep
Link ID: 11022 - Posted: 11.29.2007

By GINA KOLATA Obesity rates in women have leveled off and stayed steady since 1999, long enough for researchers to say the plateau appears to be real. And, they say, there are hints that the rates may be leveling off for men, too. The researchers’ report, published online at cdc.gov/nchs, used data from its periodic national surveys that record heights and weights of a representative sample of Americans. Those surveys, said Cynthia L. Ogden, an epidemiologist at the National Center for Health Statistics and the lead author of the new report, are the only national ones that provide such data. Dr. Ogden added that the trend for women was “great news.” Obesity rates have held at about 35 percent since 1999, convincing her that the tide had changed. “I’m optimistic that it really is leveling off,” she said. Men’s rates increased until 2003, when they hit 33 percent and stayed there through 2005-6. Dr. Ogden said she would like to see a few more years of data before declaring that men’s rates had stopped increasing. Obesity is defined as a body mass index, a measure of weight for height, of 30 or greater. For example, someone 5 feet 6 inches tall would be obese at 186 pounds. The goal at the Centers for Disease Control and Prevention is for the obesity rate to be no more than 15 percent by 2010. The last time that rate was seen was 1980. Copyright 2007 The New York Times Company

Keyword: Obesity
Link ID: 11021 - Posted: 06.24.2010

High blood pressure coupled with Alzheimer's may make patients more vulnerable to the effects of the neurological disease, finds a new study. Researchers at the University of Pittsburgh discovered that high blood pressure reduces the flow of blood to the brain. "While hypertension is not a cause of Alzheimer's disease, our study shows that it is another hit on the brain that increases its vulnerability to the effects of the disease," said study co-author Cyrus Raji, a scientist and Ph.D. candidate at the University of Pittsburgh, in a release. High blood pressure, in which blood circulates through the body too forcefully, leads to an elevated risk for heart attack, stroke and aneurysm, say researchers. The findings were presented Tuesday in Chicago at the annual meeting of the Radiological Society of North America. "These results suggest that by changing blood flow to the brain, hypertension — treated or untreated — may contribute to the pathology of Alzheimer's," Raji said. © CBC 2007

Keyword: Alzheimers
Link ID: 11020 - Posted: 06.24.2010

Millions of Americans, especially children, are needlessly getting dangerous radiation from “super X-rays” that raise the risk of cancer and are increasingly used to diagnose medical problems, a new report warns. In a few decades, as many as 2 percent of all cancers in the United States might be due to radiation from CT scans given now, according to the authors of the report. Some experts say that estimate is overly alarming. But they agree with the need to curb these tests particularly in children, who are more susceptible to radiation and more likely to develop cancer from it. “There are some serious concerns about the methodology used,” but the authors “have brought to attention some real serious potential public health issues,” said Dr. Arl Van Moore, head of the American College of Radiology’s board of chancellors. Because doctors underestimate the radiation risk from computed tomography or CT scans, a type of souped-up X-ray, they may be ordering too many of the scans, David Brenner and Eric Hall of Columbia University Medical Center in New York said. © 2007 MSNBC Interactive

Keyword: Brain imaging
Link ID: 11019 - Posted: 06.24.2010

Scans have shown that paedophilia may be the result of faulty connections in the brain. Researchers used sophisticated MRI scans to compare the brains of paedophiles and non-sexual criminals. Paedophiles had significantly less of a substance called "white matter", responsible for wiring the different parts of the brain together. The study, by the Centre for Addiction and Mental Health in Toronto, appears in the Journal of Psychiatry Research. The study follows work by Yale University which uncovered differences in the thought patterns of paedophiles. They team found activity in parts of paedophiles' brains were lower than in other volunteers when shown adult, erotic material. It had been widely thought that paedophilia was triggered by childhood trauma or abuse. However, the condition has also been linked to low IQ, suggesting a possible link to brain development. Paedophiles are also three times more likely to be left-handed. Lead researcher Dr James Cantor said the latest study found a signficant lack of white matter connecting six different areas of the brain all known to play a role in sexual arousal. His theory is that the lack of adequate wiring between the different centres results in paedophiles not being able to differentiate between appropriate and inappropriate sexual objects. However, Dr Cantor stressed the latest study did not suggest that paedophiles could not be held criminally responsible for their actions. He said: "Not being able to choose your sexual interests doesn't mean you can't choose what you do." (C)BBC

Keyword: Sexual Behavior; Brain imaging
Link ID: 11018 - Posted: 11.29.2007

WASHINGTON - The most widely used flu drug in the world should carry a stronger warning label about psychiatric problems seen in a handful of patients, government advisers said Tuesday. A panel of experts to the Food and Drug Administration recommended drug maker Roche change the warning label for Tamiflu, which has been used by 48 million patients since its launch in 1999. The drug’s label already mentions reports of delirium and self-injury, primarily among children in Japan, but some FDA’s experts suggested the language should mention several patients died as a result of these abnormal behaviors. The panel was discussing specifics of the language late Tuesday. While FDA’s advisers agreed stronger warnings were needed, they said that it is unclear whether the psychiatric problems are a side effect of the drug or the flu itself. Some panelists said labeling should point out that similar deaths have also occurred in flu patients not on medication. Nearly 600 cases of psychiatric problems have been reported in Tamiflu patients, with 75 percent of them coming from Japan. Five children there have died after “falling from windows or balconies or running into traffic,” according to FDA. Japan accounts for two thirds of the $2.4 billion global market for Tamiflu because doctors there almost always prescribe drugs to treat flu symptoms. © 2007 Microsoft

Keyword: Miscellaneous
Link ID: 11017 - Posted: 06.24.2010

What goes through the mind of a gun-toting teenager when he pulls the trigger? Does he make a conscious decision to kill? Or is he acting on instinct? The debate over why teens turn violent usually focuses on family breakdown, drug and alcohol abuse, poverty, unemployment, even diet. However, in recent years science has started to shed a fascinating light on the underlying causes of youth crime by asking whether violence is a symptom of a sick or underdeveloped brain. This question is at the heart of a new project launched by Camila Batmanghelidjh, the founder of Kids Company. She takes an imaginative approach to improving the lives of neglected and abused children. Her organisation, which works in 33 schools across London and is one of The Daily Telegraph's chosen charities for this year's Christmas appeal, started a pilot scheme this month to examine the brains and behaviour of young offenders, in order to help understand how they think. "Neglected and traumatised children do not appraise a situation objectively," Camila says. "They don't come to the point of a moral decision with a neutral frame of mind." © Copyright of Telegraph Media Group Limited 2007

Keyword: Aggression; ADHD
Link ID: 11016 - Posted: 06.24.2010

-- Amputees given prosthetic limbs could soon "feel" with their new hands or feet, after a team of scientists successfully rerouted two patients' key nerves. Scientists at the Rehabilitation Institute of Chicago and Northwestern University announced late Monday they had rerouted through their chests the nerves of two patients that had transferred sensation from the hand to the brain. After several months during which the nerves re-established themselves in the chest muscles, physical pressure, heat and cold, and electrical stimulus were applied to the areas of the nerves and the patients said they could feel the effect. In some of the testing, the patients could even specify which area on the hand they could feel; one, a woman identified as STH, at one point pinpointed a strong feeling of the skin stretching and the joint position of her ring finger being extended. Moreover, the patients consistently distinguished between the sensation of the chest nerves and those of the missing limbs. The scientists suggest their success in reviving such specific sensation identified with missing limbs could lead to establishing nervous system feedback in prosthetic devices like artificial hands, arms, feet and legs. © 2007 Discovery Communications

Keyword: Pain & Touch; Robotics
Link ID: 11015 - Posted: 06.24.2010

By NICHOLAS BAKALAR A new study has found a link between asthma and post-traumatic stress disorder, though the reasons remain unknown. The stress disorder, P.T.S.D. for short, is common among combat veterans and others who have endured severe trauma, like 9/11 rescue workers. Previous studies have demonstrated a connection between asthma and psychiatric illnesses, but no one knows whether one disorder increases the risk for the other or whether they share a common risk factor, either environmental or genetic. Researchers used data on 3,065 male twin pairs who had lived together as children and had active duty in the Vietnam War. They adjusted the findings to eliminate the influence of depression, smoking, age, body mass index, exposure to combat and other variables. One-fourth of men with the most severe symptoms of the stress disorder were more than twice as likely to suffer from asthma as the quarter with the fewest P.T.S.D. symptoms. The association cannot be fully explained by familial or genetic factors; identical twins, who have exactly the same genes, were no more likely to suffer from both illnesses than fraternal twins, who share only half their genes. Copyright 2007 The New York Times Company

Keyword: Stress
Link ID: 11014 - Posted: 06.24.2010

By MICHAEL BALTER Twelve brains were arranged on the work bench of Ralph Holloway’s anthropology laboratory at Columbia University. They were not real brains, but endocasts — latex molds made from the interiors of the skulls that once housed them. Nevertheless, many of their ridges and furrows were clearly visible. Ralph Holloway pioneered the endocast technique, in which latex brain molds are made from the interiors of the skulls that housed them. Dr. Holloway showed one of them to a visitor. “This is Homo floresiensis,” he said, a k a the “Hobbit,” a tiny hominid that lived 18,000 years ago on the Indonesian island of Flores. The other 11 were those of modern humans who had microcephaly, a pathological condition characterized by a small brain and head. While many anthropologists are convinced the Hobbit represents a new species of human, some argue vociferously that it is a microcephalic Homo sapiens with nothing new to say about evolution. Dr. Holloway said he was still “on the fence” about the controversy. “Homo floresiensis does not show any of the classic signs of microcephaly,” he said. “On the other hand, its brain does show a highly unusual degree of platycephaly,” a marked flattening of the brain. This could indicate that the Hobbit was suffering from some other sort of pathology. Copyright 2007 The New York Times Company

Keyword: Evolution
Link ID: 11013 - Posted: 06.24.2010

By Dennis Drabelle My friend Rachel and I are pumped because we get to see Ang Lee's new movie free of charge. There's a hitch, though: Instead of passes, we have to bring medallions to the theater, and we can't just hand these over at the door. We must wear them on our noses, embedded in our flesh. A free flick is nothing to sniff at, so we fasten the medallions on. (They come with handy little points.) Miraculously, they don't cause pain, though mine keeps threatening to fall off. I can't say how good the movie was -- we never got that far. As you may have guessed, the above was a dream. On awakening, I recalled having read a squib about Ang Lee and his ultra-sexy new film, "Lust, Caution," the day before, but that pretty much exhausted the real-world triggers for my scenario. Though the dream was trifling, I liked it for its silliness and simplicity. And as dreamers are wont to do, I wondered if it might have a meaning, if it revealed something unknown to my waking mind about what makes me tick. To see what could be made of it, I consulted the psychological literature and got in touch with experts in the field. In doing so, I discovered that I've had the wrong idea about dreams, which turn out to be not so much puzzles to be solved as mirrors to be gazed at. Freud called dreaming "the royal road to the unconscious," and Freudian theory would say that my nose-medallion dream stemmed from some repressed wish, probably left over from childhood and tucked away in my unconscious, where my alert self didn't have to confront it. For all I know, having to wear the medallion could be a reprimand for wanting to ogle the naked bodies of Lee's actors. I might object that I'm too old for piercing and that built-in jewelry would clash with my self-image, but could the unconscious me harbor a longstanding perforation wish just the same? © 2007 The Washington Post Company

Keyword: Sleep
Link ID: 11012 - Posted: 06.24.2010

By HENRY FOUNTAIN It’s a jungle out there — and a desert, an ocean and a savanna, too. So it helps to know your enemies. While many animals can tell friend from foe, relatively few have been shown to be able to distinguish among predator species based on the type of threat they represent. A potentially even more useful ability would be to be able to tell which of several groups of a single predator species are the ones to worry about. African elephants, it turns out, have this ability. Lucy A. Bates and Richard W. Byrne of the University of St. Andrews in Scotland and colleagues have demonstrated that using odor and visual cues elephants are able to classify subgroups within a predator species. The species in question? Homo sapiens. In a report in Current Biology, the researchers describe their experiments in Amboseli National Park in Kenya. Elephants in the region encounter different ethnic groups, including the Maasai, whose young men spear elephants, and the Kamba, agricultural villagers who pose no threat at all. The researchers observed elephants exposed to the scent from identical cloth garments, some worn by Maasai men, others by Kamba men and some that were unworn. The Maasai scent produced the strongest reactions, with elephants moving farther and faster to distance themselves from the odor source, often not stopping until reaching tall grass. The elephants also took far longer to calm down than those exposed to scents from the Kamba and unworn cloths. Copyright 2007 The New York Times Company

Keyword: Chemical Senses (Smell & Taste)
Link ID: 11011 - Posted: 06.24.2010