A tropical parasitic disease is becoming an increasingly common cause of stroke, experts say. Some 18m people worldwide have Chagas disease, caused by an infection with the parasite Trypanosoma cruzi. Recently, researchers discovered having this disease puts the individual at increased risk of stroke due to heart complications and blood clots. In Lancet Neurology, the Spanish team warns of a growing but neglected stroke burden as the infected population ages. Chagas disease is endemic in Latin America. But emigration of millions of people to Europe, North America, Japan and Australia over the past 20 years has also made Chagas disease an emerging health problem in these countries with the potential to cause a substantial disease burden, say the investigators. One study estimates that more than 300,000 Latin American immigrants with Chagas disease could be living in the US. Another problem, say the research team, is that many patients with Chagas disease do not know they are infected. Dr Francisco Javier Carod-Artal from the Virgen de la Luz hospital in Cuenca said a recent study showed that in just under half of Chagas patients treated for a stroke had not yet been diagnosed with the infection. He and colleague Joaquim Gascon, from Barcelona, say stroke patients from endemic countries should be screened for Chagas. And doctors and the public need to be made aware of the increased risk of stroke with this disease. "Clinical trials are needed," they add, to assess if blood thinning drugs might help prevent stroke in Chagas. (C)BBC

Keyword: Stroke
Link ID: 13986 - Posted: 04.19.2010

by Carl Zimmer The qualities that set a great athlete apart from the rest of us lie not just in the muscles and the lungs but also between the ears. That’s because athletes need to make complicated decisions in a flash. One of the most spectacular examples of the athletic brain operating at top speed came in 2001, when the Yankees were in an American League playoff game with the Oakland Athletics. Shortstop Derek Jeter managed to grab an errant throw coming in from right field and then gently tossed the ball to catcher Jorge Posada, who tagged the base runner at home plate. Jeter’s quick decision saved the game—and the series—for the Yankees. To make the play, Jeter had to master both conscious decisions, such as whether to intercept the throw, and unconscious ones. These are the kinds of unthinking thoughts he must make in every second of every game: how much weight to put on a foot, how fast to rotate his wrist as he releases a ball, and so on. In recent years neuroscientists have begun to catalog some fascinating differences between average brains and the brains of great athletes. By understanding what goes on in athletic heads, researchers hope to understand more about the workings of all brains—those of sports legends and couch potatoes alike. As Jeter’s example shows, an athlete’s actions are much more than a set of automatic responses; they are part of a dynamic strategy to deal with an ever-changing mix of intricate challenges. Even a sport as seemingly straightforward as pistol shooting is surprisingly complex. A marksman just points his weapon and fires, and yet each shot calls for many rapid decisions, such as how much to bend the elbow and how tightly to contract the shoulder muscles.

Keyword: Intelligence
Link ID: 13985 - Posted: 06.24.2010

By Jeanna Bryner Catching a partner checking out a hot guy or gal can do a number on even the most confident person. New research suggests the resulting jealousy can actually distract a person so much they miss what's right in front of their eyes. In the study, heterosexual romantic couples sat near each other at individual computers separated by a curtain. The women had to pick out certain landscape and architectural photos that were rotated 90-degrees within images of streams that flashed onto the screen. During the photo session, the participants also had to ignore occasional emotionally unpleasant images that were gruesome or graphic in some way. Meanwhile, the guys were asked to rate the attractiveness of landscapes that appeared on their screens. Simple enough. Then, partway through the experiment, the experimenter announced the male partner would rate the attractiveness of other single women. At the end of the experiment, the gals indicated how uneasy they felt about their partner scoping out other women. Jealous women were found to be more distracted. The more jealous they reported feeling, the more distracted they were by the emotional images and therefore they were less able to pick out the targets they were being tested on. © 2010 LiveScience.com.

Keyword: Attention; Emotions
Link ID: 13984 - Posted: 06.24.2010

Intense, robot-assisted therapy can help stroke victims regain some arm movement years after their brain injury, U.S. researchers have found. Rehabilitation normally starts immediately after a stroke and lasts six months. Conventional thinking has been that any rehabilitation beyond that initial period has little benefit for stroke survivors, but recent studies are starting to suggest otherwise. A three-year randomized control trial of 127 veterans in the U.S. found that stroke victims who had 12 weeks of robot-assisted therapy for their stroke-damaged arm had an improved quality of life compared with those who had no additional therapy beyond the initial rehabilitation period. The results of the study appear in Friday's online issue of the New England Journal of Medicine. The veterans in the study had experienced a stroke that resulted in moderate to severe disability in an arm. The strokes had occurred at least six months earlier and, on average, five years earlier. After six months, the 49 patients who received robotic therapy designed at the Massachusetts Institute of Technology showed clinically significant upper-arm function compared with the 28 patients who did not receive specific therapy for their upper limb. Another 50 patients did similar high-intensity exercises with a therapist but without the aid of the robotic device. © CBC 2010

Keyword: Stroke; Regeneration
Link ID: 13983 - Posted: 06.24.2010

Lizzie Buchen Ecstasy, a drug that is illegal in most countries, is showing increasing potential as a treatment for post-traumatic stress disorder (PTSD), according to clinical-trial results presented at a conference in San Jose, California, today. The effect seems to continue for years after the initial treatment. People can develop PTSD after traumatic experiences such as sexual abuse, or witnessing extreme acts of violence. Patients are plagued by flashbacks and nightmares, and often become emotionally numb and easily frightened. Treatment includes cognitive behavioural therapy and selective serotonin reuptake inhibitors (SSRIs) such as paroxetine (Paxil) and sertraline (Zoloft), but many people with PTSD do not respond to these treatments. Ecstasy, otherwise known as MDMA (3,4-Methylenedioxymethamphetamine), causes the release of neurotransmitters such as serotonin in the brain, and so could help to decrease the patient's fear and defensiveness during treatment The drug was used during therapy in the 1970s but with the rise of rave culture in the 1980s, the US Drug Enforcement Agency and the World Health Organization listed MDMA as a Schedule I drug — a classification reserved for drugs with no medical use and high potential for abuse — making it nearly impossible to use in clinical trials. Since 1986, the Multidisciplinary Association for Psychedelic Studies (MAPS), a nonprofit research group based in Santa Cruz, California, has struggled to obtain permission to study the therapeutic potential of MDMA, other psychedelic drugs and marijuana, but now the group's efforts are beginning to bear fruit. © 2010 Nature Publishing Group,

Keyword: Learning & Memory; Stress
Link ID: 13982 - Posted: 06.24.2010

By Steve Connor The human mind may be inherently incapable of dealing with more than two tasks at a time according to a study showing that "multi-tasking" skills are limited by the physical division of the brain into two hemispheres. Scientists have found that when people have to carry out two tasks simultaneously their brains divide each job up so that one is performed largely by the left side of the brain and the other is carried out mainly on the right. The study suggests that this basic division of the brain into two halves may explain why human beings tend to prefer a simple choice between two options rather than three or more. It might even explain why the Liberal Democrats, as the third political party, find it hard to get a look in at general elections. Sylvain Charron and Etienne Koechlin of France's National Institute of Health and Medical Research in Paris, discovered the way the brain divides up two simultaneous tasks. They asked 32 volunteers to carry out two different mental puzzles while their brains were being scanned by an MRI machine. "Each subject was performing two tasks concurrently. One task was to pair upper case letters and the other task was to pair lower case letters together. It was a very simple task and the subjects had to switch back and forth between them," Dr Koechlin said. ©independent.co.uk

Keyword: Attention
Link ID: 13981 - Posted: 06.24.2010

By John Horgan You know that psychedelics are making a comeback when the New York Times says so on page 1. In “Hallucinogens Have Doctors Tuning In,” John Tierney reports on how doctors at schools like Harvard, Johns Hopkins, UCLA and NYU are testing the potential of psilocybin and other hallucinogens for treating depression, obsessive-compulsive disorder, post-traumatic stress disorder, alcoholism—and for inducing spiritual experiences. Tierney’s brisk overview neglects to mention the most mind-bending of all psychedelics: dimethyltryptamine, or DMT. It was first synthesized by a British chemist in the 1930s, and its psychotropic properties were discovered some 20 years later by the Hungarian-born chemist Stephen Szara, who later became a researcher for the National Institute on Drug Abuse. Why is DMT so fascinating? For starters, DMT is the only psychedelic known to occur naturally in the human body. In 1972, the Nobel laureate Julius Axelrod of the National Institutes of Health discovered DMT in human brain tissue, leading to speculation that the compound plays a role in psychosis. Research into that possibility—and into psychedelics in general--was abandoned because of the growing backlash against these compounds. In 1990, however, Rick Strassman, a psychiatrist at the University of New Mexico, obtained permission from federal authorities to inject DMT into human volunteers. Strassman, a Buddhist, suspected that endogenous DMT might contribute to mystical experiences. © 2010 Scientific American

Keyword: Drug Abuse
Link ID: 13980 - Posted: 06.24.2010

By Erik Vance Big test coming up? Having trouble concentrating? Try a little estrogen. Neuroscientists at the University of California, Berkeley, report in a recent study that hormone fluctuations during a woman’s menstrual cycle may affect the brain as much as do substances such as caffeine, methamphetamines or the popular attention drug Ritalin. Scientists have known for decades that working memory (short-term information processing) is dependent on the chemical dopamine. In fact, drugs like Ritalin mimic dopamine to help people concentrate. Researchers have also had evidence that in rats, estrogen seems to trigger a release of dopamine. The new study from Berkeley, however, is the first to show that cognition is tied to estrogen levels in people—explaining why some women have better or worse cognitive abilities at varying points in their menstrual cycles. The Berkeley team examined 24 healthy women, some of whom had naturally high levels of dopamine and some of whom had low levels, as indicated by genetic testing. As expected, those with the lower levels struggled with complicated working memory tasks, such as repeating a series of five numbers in reverse order. When the test was repeated during ovulation, however, when estrogen levels are highest (usually 10 to 12 days after menstru­ation), these women fared markedly better, improving their performance by about 10 per­cent. Surprisingly, those with naturally high dopamine levels took a nosedive in their ability to do complicated mental tasks at that point in their cycle.

Keyword: Hormones & Behavior; ADHD
Link ID: 13979 - Posted: 06.24.2010

By Emily Sohn To be an American woman and feel good about your body requires a powerful inner strength and the will to resist an unrealistically skinny social ideal. But even women who truly accept themselves as they are have internalized the desire to be thin, suggests a new study that looked deep into women's brains. The study found that the brains of healthy women resemble those of bulimic women when confronted with the idea that they might be overweight. The findings might eventually help doctors better evaluate and treat body image issues, no matter how subtle. "This is kind of validating the suspicion that most women are teetering on the edge of an eating disorder," said Mark Allen, a neuroscientist at Brigham Young University in Provo, Utah. "If the brain response is so strong in these apparently healthy women, maybe most of us could use a little dose of what it is that you go through in an eating disorder therapy." Who are you? What makes you unique? What fulfills you? Are you friendly, cheerful, grumpy or important? When people consider questions like these that force them to engage in serious self-reflection, activity picks up in a part of the brain called the medial prefrontal cortex. Scientists have suspected that this self-reflective part of the brain could betray subconscious thoughts that people might not even know they have. For example, other studies have shown that, in tasks like word-associations, people who don't think they're racist still show racist tendencies when they don't have time to consciously override what's under the surface. © 2010 Discovery Communications, LLC.

Keyword: Anorexia & Bulimia
Link ID: 13978 - Posted: 06.24.2010

by Wendy Zukerman She's only horny for a few hours a year – so there's no time to lose. To ensure the male tammar wallaby (Macropus eugenii) is ready for action, he experiences a surge of testosterone when females are on heat. But it has been unclear whether this effect is seasonally hard-wired or somehow caused by the presence of females. It's the latter, says Marilyn Renfree of the University of Melbourne, Australia. With colleagues, she has induced female tammar wallabies to come on heat out of season, and found males still experienced testosterone surges. Adult female tammar wallabies mate once a year – at the end of January, just hours after giving birth. The fertilised embryo then lies dormant for months while the female lactates and tends to her current baby. The embryo's development is reactivated in December, and as soon as it's born, the race to mate is on once more as oestrogen surges through the females for a few hours, making them highly receptive to male advances. The female reproductive cycle is controlled during the first half of the year by suckling young, and in the second half by the hormone melatonin, which responds to the changing light levels of the seasons. If young are removed from their pouch in the first half of the year or females are injected with melatonin in the second half, embryonic development restarts out of season. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 13977 - Posted: 06.24.2010

by Helen Thomson BRAIN cells that may underlie our ability to empathise with others have been detected directly in people for the first time. Monkey brains have been shown to contain so-called "mirror" neurons, which fire both when the animal performs an action and when it observes others performing that action. Until now, the only evidence that our brains contain similar neurons has been indirect, derived from functional MRI scans. Now Roy Mukamel at the University of California, Los Angeles, and colleagues have observed mirror neurons directly in humans. They used electrodes to record brain activity in the medial frontal and temporal cortices of 21 people awaiting surgery to treat epilepsy, while they made - or observed others making - grasping actions and facial expressions. The majority of these neurons responded only to the observation or execution of an action, but 8 per cent of the cells responded to both (Current Biology, DOI: 10.1016/j.cub.2010.02.045). These areas of the brain are involved in planning and controlling actions, abstract thinking and memory. Mirror neurons were thought to exist primarily in regions of the brain involved in performing actions, so their presence in other regions suggests that this is not their only role. Other studies have found that people who appear to have more active mirror neurons also tend to be more empathetic. Marco Iacoboni, another member of the team and also at UCLA, says his team's results suggest that human mirror neurons provide "a rich reflection of the actions of others". © Copyright Reed Business Information Ltd

Keyword: Vision
Link ID: 13976 - Posted: 06.24.2010

By CYNTHIA GORNEY Here we are, two fast-talking women on estrogen, staring at a wall of live mitochondria from the brain of a rat. Mitochondria are cellular energy generators of unfathomably tiny size, but these are vivid and big because they were hit with dye in a petri dish and enlarged for projection purposes. They’re winking and zooming, like shooting stars. “Oh, my God,” Roberta Diaz Brinton said. “Look at that one. I love these. I love shooting mitochondria.” Brinton is a brain scientist. Estrogen, particularly in its relationship to the health of the brain, is her obsession. At present it is mine too, but for more selfish reasons. We’re inside a darkened lab room in a research facility at the University of Southern California, where Brinton works. We are both in our 50s. I use estrogen, by means of a small oval patch that adheres to my skin, because of something that began happening to me nine years ago — to my brain, as a matter of fact. Brinton uses estrogen and spends her work hours experimenting with it because of her own brain and also that of a woman whose name, Brinton will say, was Dr. A. She’s dead now, this Dr. A. But during the closing years of her life she had Alzheimer’s, and Brinton would visit her in the hospital. Dr. A. was a distinguished psychotherapist and had vivid stories she could still call to mind about her years in Vienna amid the great European psychologists. “We’d spend hours, me listening to her stories, and I’d walk out of the room,” Brinton told me. “Thirty seconds later, I’d walk back in. I’d say, ‘Dr. A., do you remember me?’ And she was so lovely. She’d say: ‘I’m so sorry. Should I?’ ” The problem with the estrogen question in the year 2010 is that you set out one day to ask it in what sounds like a straightforward way — Yes or no? Do I or do I not go on sticking these patches on my back? Copyright 2010 The New York Times Company

Keyword: Hormones & Behavior
Link ID: 13975 - Posted: 06.24.2010

By Jennifer Viegas Remains of a 1.9-million-year-old human ancestor are so well preserved that they may contain a remnant of the male individual's brain, according to the European Synchrotron Radiation Facility in Grenoble, France, where the remains were recently examined. While DNA is very fragile and deteriorates over time, the discovery opens up the remote possibility that soft tissue with preserved DNA still exists in the prehistoric hominid, which could hold an important place on the human family tree. The examination also turned up what seemed to be fossilized insect eggs, according to scientists. They said larvae from the eggs could have fed on the flesh of the human ancestor, Australopithecus sediba, right after his death. While gazing at the hominid's skull as it was being studied with a powerful electromagnetic radiation X-ray process, project leader Lee Berger said he and his team were seeing "structures we can't even imagine in a way that's quite literally unprecedented in paleontological sciences." Berger, a senior research officer and director of the School of Geosciences at the University of Witwatersrand, and his colleagues focused on the teeth and "parts of the body that don't normally fossilize," such as the brain. While further testing is needed, the researchers believe an "extended shadow" hints that a remnant of the brain after its bacterial decay is still present in the ancient remains. © 2010 Discovery Channel

Keyword: Evolution
Link ID: 13974 - Posted: 06.24.2010

By Christof Koch There is ample evidence that men and women think, express themselves and even experience emotions differently (for more details, read on through this issue). But in the area of sensory perception, psychologists are hard-pressed to identify major discrepancies. By and large, the way the two genders experience the sounds, sights and smells of life is quite similar. The most striking exception may be found, at least for some, in the perception of colors. Seeing in color is a complex process, as you may remember from your school days. It starts with the delicate lining of the eyes, a structure called the retina. Retinal tissue contains light-sensitive cells that absorb wavelengths in the visible spectrum and convert them into electrical signals. The brain interprets this information as the riot of colors we consciously experience. The retinal cells called cones come in three varieties. The S-type cone is maximally sensitive to light in the short-wavelength (blue) part of the visible spectrum, the M-type cone responds best to medium wavelengths, and the L-type to long, reddish wavelengths. People with normal color vision are known as trichromats because they possess these three kinds of photosensitive cone cells. About 8 percent of men, but fewer than 1 percent of women, have impoverished color vision, typically because they lack the gene for either the L- or the M-type photopigment. While their vision is normal in every other way, they suffer from what is often called red-green color blindness. Depending on the specific genetic omission involved, such people—who are known as dichromats because they have only two types of cone cells—are unable to distinguish between violet, lavender and purple or between red, orange, yellow and green. © 2010 Scientific American,

Keyword: Vision; Genes & Behavior
Link ID: 13973 - Posted: 06.24.2010

by Wendy Zukerman Smoking could predispose people to dementia, not protect them as has been suggested in the past. This is the conclusion from lab experiments in which rats with brain plaques developed further symptoms of Alzheimer's when given nicotine. In Alzheimer's disease, the brain becomes riddled with amyloid protein plaques and tangles of tau proteins. Low doses of nicotine have been shown to reduce the number of plaques in rats, but till now little was known about the effect of nicotine on the protein tangles. To find out, Yan-Jiang Wang's team at the Third Military Medical University in Chongqing, China, injected amyloid plaques into the brains of healthy rats and gave some the equivalent of a smoker's daily dose of nicotine for two weeks, while others received nothing. All the rats showed early signs of tau tangles and had difficulty navigating a maze, but the rats that were on nicotine did worse than those that were not. Smokers take note Jürgen Goetz, of the Brain and Mind Research Institute at the University of Sydney, Australia, says the results are likely to have implications for humans. Some previous studies, many of them funded by tobacco companies, have indicated that smokers are less likely to develop Alzheimer's. But when a team of researchers re-examined 43 studies earlier this year, discounting the industry-funded ones, they concluded that smoking actually increases the risk of Alzheimer's Journal reference: European Journal of Pharmacology , DOI: 10.1016/j.ejphar.2010.03.029 © Copyright Reed Business Information Ltd.

Keyword: Alzheimers; Drug Abuse
Link ID: 13972 - Posted: 06.24.2010

By Anne Miller Glass shards glistened sharply in a pool of water on the kitchen floor. My mom assured my fiance, Michael Davoli, that the old cheap glass didn't matter, but he still looked shell-shocked. He was always so careful to place drinks safely in front of himself: Anything too near his hands could be toppled. He helped my mother pick up the pieces and said he hadn't knocked over a glass in years. Such is life with Tourette's syndrome. Most people know the stereotype of unpredictable and uninhibited cursing or barking. Those symptoms do exist, for some people. But the truth is much more complicated. Michael, who has been my husband since August, doesn't curse unless he wants to. But as with the majority of people with Tourette's, there are myriad ways his inability to control some of his movements affects how he navigates his days. How and why people develop Tourette's remains a mystery. Research indicates a genetic tie: Those with Tourette's have a 50 percent chance of passing it to their children, and it's not unusual for someone with Tourette's to have a relative who also has the syndrome. The condition typically manifests in grade school, often with rapid eye blinks, and more often in boys than in girls. Medical experts estimate that as many as one in 100 people suffer from Tourette's. It is also associated with creative personalities: Composer Wolfgang Amadeus Mozart, writer Samuel Johnson and jazz great Thelonious Monk may have had it. In the sports world, Jim Eisenreich, who won a World Series with the Florida Marlins in 1997, and Tim Howard, a goalie on the U.S. national soccer team, live with Tourette's. © 2010 The Washington Post Company

Keyword: Tourettes
Link ID: 13971 - Posted: 06.24.2010

By Katie Moisse A little stress can do us good—it pushes us to compete and innovate. But chronic stress can increase the risk of diseases such as depression, heart disease and even cancer. Studies have shown that stress might promote cancer indirectly by weakening the immune system's anti-tumor defense or by encouraging new tumor-feeding blood vessels to form. But a new study published April 12 in The Journal of Clinical Investigation shows that stress hormones, such as adrenaline, can directly support tumor growth and spread. For normal cells to thrive in the body, "they need to be attached to their neighbors and their surroundings," says the study's lead author Anil Sood from The University of Texas M. D, Anderson Cancer Center in Houston. Cells that detach from their environment undergo a form of programmed cell death called anoikis. "But cancer cells have come up with way to bypass this effect—they avoid anoikis," Sood says. This allows cancer cells to break off from tumors, spread throughout the body (in blood or other fluid) and form new tumors at distant sites—a process called metastasis. So Sood wondered: Could stress affect anoikis? "It surprised us that this biology hadn't been studied before," he notes. "Stress influences so many normal physiological processes. Why wouldn't it be involved in tumor progression?" Sood and his team first studied the effects of stress hormones on human ovarian cancer cell anoikis in culture. Cells that were exposed to stress hormones were protected from self destruction—meaning they could survive without being anchored to their surroundings. The stress hormone treatment activated a protein called FAK (focal adhesion kinase), which is known to protect cells from anoikis. Inhibiting FAK reversed the effects. © 2010 Scientific American,

Keyword: Stress
Link ID: 13970 - Posted: 06.24.2010

By Nathan Seppa Losing weight on purpose in old age may provide a survival edge, at least for obese people, a new analysis shows. Writing in an upcoming issue of the Journal of Gerontology: Medical Sciences, researchers tackled a long-held assumption that weight loss in old age is uniformly unhealthy. The idea stems from overpowering data linking rapid, unintentional weight loss in the elderly to a hidden underlying problem, such as the onset of type 2 diabetes. “The loss of weight over six months without a specific cause is a very bad prognostic sign,” says study coauthor Stephen Kritchevsky, an epidemiologist at Wake Forest University School of Medicine in Winston-Salem, N.C. That has ingrained the notion among doctors that any weight loss in the elderly is risky, he says. “I’ve been at meetings on nutrition in the elderly, and there have been reputable geriatricians who have said in public that if you ask an older person to lose weight you’re committing malpractice,” he says. To assess the effects of intended weight loss, Kritchevsky and his colleagues analyzed data collected by a long-term trial in the 1990s. In the study 316 obese people, average age 70, were randomly assigned in roughly equal numbers to one of four interventions: a dieting program, dieting plus exercise, exercise only or health education only. The people had arthritic knees but were otherwise free of major health problems. © Society for Science & the Public 2000 - 2010

Keyword: Obesity
Link ID: 13969 - Posted: 06.24.2010

by Cassandra Willyard Two genetic studies involving thousands of participants suggest that age-related macular degeneration, an eye disease common among the elderly, is tied to a gene that helps regulate “good” cholesterol. The studies present the first genetic evidence of a link between cholesterol and the disease, and they may lead scientists to identify new targets for therapy. Age-related macular degeneration is the leading cause of blindness in older adults in the United States. Lesions form behind the retina, impeding the center of an individual’s field of vision. A link between cholesterol and an eye disease might sound strange, but scientists have known for years that cholesterol can accumulate at the back of the eye as part of aging. Moreover, cholesterol is a major component of the macular lesions. What role cholesterol plays in the eye, however, remains unclear. In the new work, scientists compared the genomes of people who have macular degeneration with the genomes of healthy individuals to search for genetic variants that occur more frequently among one group or the other. In the first study, Johanna Seddon, a genetic epidemiologist at Tufts University in Boston and colleagues scanned the genomes of 979 people with advanced degeneration and 1709 healthy people. The researchers found a strong association with a variant of the hepatic lipase gene (LIPC). LIPC codes for an enzyme involved in the metabolism of HDL, or “good,” cholesterol. People with this variant had an 18% reduced risk of having the disease. A scan of 4337 other cases and 2077 controls yielded the same result. The researchers also found weaker associations with three other genes involved in the HDL pathway: ABCA1, CETP, and LPL. These weaker associations did not meet the strict criteria necessary in this type of study to achieve statistical significance. © 2010 American Association for the Advancement of Science

Keyword: Vision; Genes & Behavior
Link ID: 13968 - Posted: 06.24.2010

By Bruce Bower Nearly 2 million years ago, an adult and a child walking through the South African landscape somehow fell through openings in a partly eroded, underground cave and died. Today, that fatal plunge has led to their identification as representatives of a new hominid species — and a contentious debate among paleoanthropologists over the pair’s evolutionary relationship to modern humans. In the April 9 Science, anthropologist Lee Berger of the University of the Witwatersrand in Johannesburg and his colleagues assign newly discovered fossils from these ancient individuals to the species Australopithecus sediba. They propose that the species served as an evolutionary bridge from apelike members of Australopithecus to the Homo genus, which includes living people. In a local African tongue, sediba means fountain or wellspring, a reference to this species as a candidate ancestor of the Homo line. “Australopithecus sediba could be a Rosetta Stone for anatomically defining the Homo genus,” Berger says. Despite the importance of finding hominid fossils from the poorly understood period between 2 million and 1.7 million years ago, paleoanthropologists familiar with the finds doubt that they will illuminate Homo origins. “There’s no compelling evidence that this newly proposed species was ancestral to Homo,” remarks Bernard Wood of George Washington University in Washington, D.C. © Society for Science & the Public 2000 - 2010

Keyword: Evolution
Link ID: 13967 - Posted: 06.24.2010