If you were used to finding food by day then suddenly switched to chasing your dinner in the dark, night-vision goggles might be a necessity. The concept applies to salmon too: New research suggests that the fish adjust the light-sensitive pigments in their eyes as they age and move to deeper waters. When young pink salmon graduate from shallow streams to the open ocean, they also change their eating habits--from nibbling plankton on the surface to hunting fish in deep water. Scientists suspected that the salmon visual system adapted as the fish moved from shallow waters dominated by ultraviolet light to deeper waters filled with blue and green light, but they had only hunches about how this might happen. The new study suggests that the salmon’s secret is shuffling the light-sensitive pigments inside their cone cells--nerve cells in the retina that respond to light. Iñigo Novales Flamarique and Christiana Cheng of Simon Fraser University in Burnaby, British Columbia, came to that conclusion by examining the retinas of young Pacific pink salmon. Copyright © 2004 by the American Association for the Advancement of Science.

Keyword: Vision; Development of the Brain
Link ID: 5155 - Posted: 06.24.2010

By Jennifer Viegas, Discovery News — High-tech underwater equipment has enabled researchers for the first time to ascribe sounds to individual killer whales, and the recordings reveal that whale families like to mimic each other when communicating. Killer whale sounds have been captured on tape before, but only in group recordings where scientists could not identify the whales making sounds. The latest data suggests whales communicate with each other in ways that are similar to humans, other primates, dolphins and birds. The findings will be published in the upcoming issue of the journal Animal Behavior. According to Patrick Miller, lead author of the paper and a scientist at the NERC Sea Mammal Research Unit at the University of St. Andrews in Scotland, he and his colleagues followed distinctively marked killer whales using a small boat that was towing a beam-forming hydrophone array. They used the beam to calculate the angle of sounds, and to identify whales that produced noises. Copyright © 2004 Discovery Communications Inc.

Keyword: Animal Communication; Language
Link ID: 5154 - Posted: 06.24.2010

NewScientist.com news service A computer program which can read words before they are spoken by analysing nerve signals in our mouths and throats, has been developed by NASA. Preliminary results show the button-sized sensors, which attach under the chin and on either side of the Adam's apple and pick up nerve signals from the tongue, throat, and vocal cords, can indeed be used to read minds. "Biological signals arise when reading or speaking to oneself with or without actual lip or facial movement," says Chuck Jorgensen, a neuroengineer at NASA's Ames Research Center in Moffett Field, California, in charge of the research. The sensors have already been used to do simple web searches and may one day help space-walking astronauts and people who cannot talk communicate. The sensors could send commands to rovers on other planets, help injured astronauts control machines, or aid the handicapped. © Copyright Reed Business Information Ltd

Keyword: Language
Link ID: 5153 - Posted: 06.24.2010

Nikolaos Bourbakis, Ph.D., Ohio Board of Regents Distinguished Professor of Information Technology at Wright State’s College of Engineering and Computer Science is the principal investigator. The project is a cooperative venture with Arizona State University (ASU). “Our object is to develop intelligent assistants that can help blind and visually impaired individuals efficiently conduct daily tasks, such as reading a book or newspaper and efficiently accessing the Web and participating in classes,” explained Bourbakis, who has been involved in computer engineering eye research for 20 years. Tyflos, the Greek word for blind, is the name of the portable, wearable device Bourbakis has developed. The partnering project at ASU is called iLearn. A tiny camera is mounted to glasses and connected by a thin wire to a modified lap-top computer the individual carries on his or her back. The Tyflos system operates by identifying the images “seen” by the camera and converting this to audio information the subject hears from small wires connected from the backpack to the ear. A small microphone is attached for receiving commands or requests from the user.

Keyword: Vision; Robotics
Link ID: 5152 - Posted: 06.24.2010

— Researchers have discovered that genetic mutations underlying two inherited eye disorders arise in different components of a single intracellular signaling pathway that is responsible for development of blood vessels in the eye. Understanding more about how this pathway functions could provide useful information for the development of drugs to treat the two diseases. That information might also aid in understanding retinal blood vessel disorders associated with diabetes, macular degeneration, and premature birth. The researchers studied two inherited disorders, Norrie disease and familial exudative vitreoretinopathy (FEVR), whose underlying genetic defects were already known, but whose mechanistic relationship was not. Norrie disease, caused by a defect in the gene for the protein Norrin, produces congenital blindness and a progressive deafness due to blood vessel malformation in the inner ear. “Almost certainly the sequence of events within the eye is that there is a problem in vascular development, a compensatory growth of blood vessels, and a leakiness in those blood vessels that leads to scarring and ultimately blindness,” said Nathans. The function of the Norrin protein was unknown before this new work, he said. ©2004 Howard Hughes Medical Institute

Keyword: Vision
Link ID: 5151 - Posted: 06.24.2010

By ALEX DOMINGUEZ, Associated Press Writer Scientists say an enzyme in the brain that monitors energy in cells also appears to regulate appetite and weight, a discovery that could lead to new treatments for obesity. The enzyme is known as AMP-activated protein kinase, or AMPK. Its activity is regulated by the hormone leptin, which previously was linked to appetite suppression. Harvard researchers found in experiments with mice that when AMPK was inhibited, the animals ate less and lost weight. When AMPK levels were boosted, the mice ate more and gained weight. Barbara B. Kahn, the lead author of the study, said the work identifies a new leptin signaling pathway and a promising new target in humans. Copyright © 2004 Yahoo! Inc.

Keyword: Obesity
Link ID: 5150 - Posted: 06.24.2010

By DAVID WILLIAMSON, UNC News Services CHAPEL HILL – Five years ago, University of North Carolina at Chapel Hill researchers first reported finding that the nutrient choline played a critical role in memory and brain function by positively affecting the brain’s physical development. Differences in development influenced action, the scientists and their colleagues found. In animal experiments conducted at Duke University, both young and old rats performed significantly better on memory tasks if they received enough choline before birth compared with same-age rats whose mothers were fed choline-deficient diets. The latter showed deficits in the hippocampus and septums of their brains. Because humans and rodents are so similar biologically, something comparable probably happens in humans, the investigators believe. Now, working with nerve tissue derived from a human cancer known as a neuroblastoma, the UNC researchers have discovered why more choline causes stem cells -- the parents of brain cells -- to reproduce more than they would if insufficient choline were available.

Keyword: Learning & Memory; Development of the Brain
Link ID: 5149 - Posted: 06.24.2010

Two independent research groups have established conclusively that prions are proteins, and that they do not depend on genes or other factors for transmission of their traits. According to the scientists, the studies answer a nagging question that had raised doubts among some researchers about the validity of the so-called “protein-only” hypothesis of prion infectivity. Scientists have grappled for years with one of the central tenets of the protein-only hypothesis, namely, that a single prion protein, when unaltered by genetic mutation, can give rise to different strains of prions with varying infectivity and other properties. The two research groups established that the strains could be accounted for by different misfolded conformations of the same protein. The researchers say this finding could contribute to better understanding of the functioning of disease-causing prions in animals and humans. Both groups published their findings in the March 18, 2004, issue of the journal Nature. Howard Hughes Medical Institute investigator Jonathan S. Weissman at the University of California at San Francisco led one group. The other effort was led by Chi-Yen King at Florida State University. ©2004 Howard Hughes Medical Institute

Keyword: Prions
Link ID: 5148 - Posted: 06.24.2010

[BLANTYRE, MALAWI] Malawian conservationists have stopped elephants leaving the Liwonde National Park and trampling nearby crops — by cultivating chilli pepper plants around the park's boundary. The findings confirm reports from other African countries that planting chillies can stop marauding elephants, which are repulsed by the plant's odour. They also demonstrate that the strategy can ease the tension that frequently arises between local development needs and conservation objectives. In recent years, wildlife officials at the 538-square-kilometre park have been deluged with complaints that elephants have damaged nearby crops. People have also been trampled to death by stampeding elephants

Keyword: Pain & Touch
Link ID: 5147 - Posted: 06.24.2010

No evidence of interbreeding between primitive humans. MICHAEL HOPKIN If our early ancestors did breed with their Neanderthal cousins, they didn't make a habit of it, according to the largest-ever study of early human DNA. Researchers compared the preserved remains of four Neanderthals and five early modern humans found throughout Western Europe. DNA from the two sets of samples was distinct enough to rule out large amounts of mixing between the two. "We detected no evidence of interbreeding," says David Serre of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, who took part in the study. But he adds that, because of the scarcity of well-preserved DNA, it is impossible to be certain that such trysts never took place. © Nature News Service / Macmillan Magazines Ltd 2003

Keyword: Evolution
Link ID: 5146 - Posted: 06.24.2010

By IRA DREYFUSS, Associated Press Writer WASHINGTON -- The Agriculture Department is planning a tenfold increase in the number of cattle tested for mad cow disease in response to discovery of the nation's first case of the disease last December. The department announced plans Monday to test more than 221,000 animals over a 12- to 18-month period beginning in June. Included would be 201,000 animals considered to be at high risk of bovine spongiform encephalopathy, or BSE, because they show symptoms of nervous system disorders such as twitching. Random tests also will be conducted on about 20,000 older animals sent to slaughter even though they appear healthy. Those tests are aimed at sampling cattle old enough to have eaten feed produced before 1997, when the Food and Drug Administration banned the use of cattle tissue in feed for other cattle. Copyright © 2004, The Associated Press

Keyword: Prions
Link ID: 5145 - Posted: 06.24.2010

By ANAHAD O'CONNOR For almost a decade, researchers at Pfizer struggled to show that Viagra, the male impotence drug, could enhance sexual function in women. Last month, they gave up. Countless tests on thousands of women made it clear that the little blue pill, though able to stir arousal, did not always evoke sexual desire. Viagra's failure underscored the obvious: when it comes to sexuality, men and women to some extent are differently tuned. For men, arousal and desire are often intertwined, while for women, the two are frequently distinct. Scientists have recently begun to map out how this difference shows up in the brain. Copyright 2004 The New York Times Company |

Keyword: Sexual Behavior
Link ID: 5144 - Posted: 03.18.2004

A chemical found naturally in the brain could be used to treat the sleep disorder narcolepsy, US scientists say. Researchers at the University of Texas said injecting a chemical called orexin stopped symptoms in mice with narcolepsy. They found the treatment made the mice more alert and reduced other narcoleptic symptoms, such as muscle weakness, called cataplexy. The study appeared in the Proceedings of the National Academy Sciences. Dr Masashi Yanagisawa, professor of molecular genetics, and colleagues studied genetically modified mice which lacked the ability to naturally produce orexin. Orexin are small chains of molecules, produced by nerve cells in the area of the brain called the hypothalamus. (C) BBC

Keyword: Narcolepsy
Link ID: 5143 - Posted: 03.16.2004

Scientists have known for some time that some social insects undergo dramatic behavioral changes as they mature, and now a research team has found that the brains of a wasp species correspondingly enlarge as the creatures engage in more complex tasks. "The amount of change is striking," said Sean O'Donnell, a University of Washington associate professor of psychology and lead author of a new study published in the February issue of Neuroscience Letters. "It is easily apparent with magnification." O'Donnell said the changes take place in sections of the brain called the mushroom bodies. There is one mushroom body on top of each hemisphere of the wasp brain and the structures have a superficial resemblance to the cerebrum in humans and other vertebrates, he said. The enlargement was centered in a part of the mushroom body called the calyx where neural connections are made. O'Donnell and other researchers study social insects such as wasps, honeybees and ants as models to understand the role of neuroplasticity in driving complex social behaviors such as the division of labor.

Keyword: Neurogenesis
Link ID: 5142 - Posted: 03.16.2004

When George Bush quietly dismissed two members of his Council on Bioethics on the last Friday in February, he probably assumed the news would get buried under the weekend’s distractions. But ten days later, it’s still hot—see, for example, two articles in Slate, and an editorial in the Washington Post, as well as Chris Mooney's ongoing coverage at his blog. Bush failed to appreciate just how obvious the politics were behind the move. The two dismissed members (bioethicist William May and biochemist Elizabeth Blackburn) have been critical of the Administration. Their replacements (two political scientists and a surgeon) have spoken out before about abortion and stem cell research, in perfect alignment with the Administration. Bush also failed to appreciate just how exasperated scientists and non-scientists alike are becoming at the way his administration distorts science in the service of politics (see this report from the Union of Concerned Scientists, which came out shortly before the bioethics flap). And finally, Bush failed to appreciate that Blackburn would not discreetly slink away. Instead, she fired off a fierce attack on the council, accusing them of misrepresenting the science behind stem cell research and other hot-button issues in order to hype non-existent dangers. The chairman of the council, Leon Kass, failed as well when he tried to calm things down last Wednesday. He claimed that the shuffling had nothing to do with politics, and that he knew nothing about the personal of his new council members. Reporters have pointed out the many opportunities when Kass almost certainly did learn about those views.

Keyword: Stem Cells
Link ID: 5141 - Posted: 06.24.2010

Do the green clovers of Saint Patrick's Day translate into green beer? As this ScienCentral News video reports, you may be surprised to hear that researchers say people sometimes decide to drink based on what they see. Lots of people drink socially and are able to do so without becoming alcoholics. What is the difference in the brain between a mere yen and a serious craving? The answer may reveal new insight into alcoholism and environmental triggers that lead to relapse. "If you are newly abstinent and you're driving home and you drive by a bar where you've been drinking for the last ten years, that's a huge trigger for you," says Hugh Myrick, a brain scientist at the Medical University of South Carolina and the Ralph H. Johnson VA Medical Center. "It's almost like the car turns into the parking lot of the bar again. we call it craving. that is also implicated in people returning to alcohol use, or for that matter, to any substance of abuse. We were very interested in trying to determine what areas of the brain are actually involved in craving for alcohol." © ScienCentral, 2000-2004.

Keyword: Drug Abuse
Link ID: 5140 - Posted: 06.24.2010

By CLAUDIA DREIFUS The first thought that Dr. Marie T. Filbin wants to convey is that it is possible to teach at a municipal college and have a great research career. "People are always putting down the City University because it is not Harvard or Rockefeller," said Dr. Filbin, 48, a professor of biological sciences at Hunter College of the City University of New York. "But Hunter is a great place for a researcher. My students are wonderful." A scientist who praises an employer is rare enough. But then Marie Filbin is an unusual scientist. Her specialty is practical: she studies why injured nerve cells do not regenerate themselves — a factor crucial to understanding the mysteries of paralysis. When not at her bench, she delivers lectures — really progress reports on her research — at nursing homes. And when she speaks to paralysis patients, she says, "They put me on the spot." Copyright 2004 The New York Times Company

Keyword: Regeneration; Stem Cells
Link ID: 5139 - Posted: 06.24.2010

By NICHOLAS WADE Once upon a time, there were very few human languages and perhaps only one, and if so, all of the 6,000 or so languages spoken round the world today must be descended from it. If that family tree of human language could be reconstructed and its branching points dated, a wonderful new window would be opened onto the human past. Yet in the view of many historical linguists, the chances of drawing up such a tree are virtually nil and those who suppose otherwise are chasing a tiresome delusion. Languages change so fast, the linguists point out, that their genealogies can be traced back only a few thousand years at best before the signal dissolves completely into noise: witness how hard Chaucer is to read just 600 years later. Copyright 2004 The New York Times Company

Keyword: Language
Link ID: 5138 - Posted: 03.16.2004

By SUSAN GILBERT For centuries, doctors have recognized women's vulnerability to depression and proposed a variety of explanations. The female of the species, with her "excitable nervous system," was thought to wilt under the strain of menstruation and childbirth, or later, the pressures of work and family. But researchers are now constructing more scientific theories to explain why women are nearly twice as likely as men to become depressed. Social bias and women's higher rates of physical and sexual abuse and poverty, experts say, clearly play a role. But scientists are also studying genes that may predispose girls and women to the disorder. They are examining the likely role of estrogen and even linking the development of clinical depression to negative thinking, which is more common in women than in men. Copyright 2004 The New York Times Company

Keyword: Depression
Link ID: 5137 - Posted: 03.16.2004

PHILADELPHIA – While it might not seem so the next time you go searching for your car keys, scientists at the University of Pennsylvania have shown that memories are not as fluid as current research suggests. Their findings challenge the prevailing notion on how memories are stored and remembered – or that a recalled memory could be altered or lost as it is "re-remembered." "Current theories of memory state that the act of remembering turns a stored memory into something malleable that then needs to be re-encoded," said K. Matthew Lattal, a postdoctoral researcher in Penn's Department of Biology and a co-author of the study. "We show that the act of retrieving an old memory and then putting it back into storage is a different process than creating a memory in the first place. Unfortunately, it could mean that 'erasing' traumatic memories is not as simple as one might hope." The study will be published in the Proceedings of the National Academy of Science and will be available on the Internet this week in the PNAS Online Early Edition. Previous studies in rodents had shown that the process of encoding a memory could be blocked by the use of a protein synthesis inhibitor called anisomycin. Experiments with anisomycin helped lead to the acceptance of a theory in which a learned behavior is consolidated into a stored form and that then enters a 'labile' – or adaptable – state when it is recalled. According to these previous studies, the act of putting a labile memory back into storage involves a reconsolidation process identical to the one used to store the memory initially. Indeed, experiments showed that anisomycin could make a mouse forget a memory if it were given anisomycin directly after remembering an event.

Keyword: Learning & Memory
Link ID: 5136 - Posted: 06.24.2010