In a landmark study, the U.S. Navy has concluded that it killed at least six whales in an accident involving common ship-based sonars. The finding, announced late last month by the Navy and the U.S. National Marine Fisheries Service (NMFS), may complicate Navy plans to field a powerful new sonar system designed to detect enemy submarines at long distances. For decades, marine mammal scientists have suspected that sonar pings produced by military ships may have played a role in a half-dozen unusual strandings of beaked whales, toothy marine mammals that often feed deep in the ocean. In each case, researchers discovered the beached whales shortly after nearby military sonar exercises, but the remains were always too decayed to reveal evidence of sound-energy injuries. On 15 March 2000, however, independent marine mammal researchers Ken Balcomb and Diane Claridge woke up to find a beached beaked whale outside their seaside home on Abaco Island in the Bahamas (Science, 26 January 2001, p. 576 ). They soon counted 17 other stranded marine mammals in nearby waters, some with apparently bleeding ears. They managed to collect tissue samples--including whole heads--from several of the six animals that had died. Government scientists launched an investigation after learning that the strandings had occurred within 24 hours of a nearby Navy training mission. Copyright © 2002 by the American Association for the Advancement of Science.

Keyword: Hearing; Animal Migration
Link ID: 1282 - Posted: 06.24.2010

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder, characterized by inattention, hyperactivity and impulsivity. It affects 4- 10% of school age children, exacting a significant clinical and public health toll. ADHD constitutes one of the main reasons for referral to neurological/psychiatric treatment in this age group, and results in exposure of many children to prolonged courses of stimulant medication such as Ritalin. Untreated, ADHD may lead to impairments in schooling and social adaptation in a critical period of development, eventuating in damage to the childÕs self esteem and personality development, with high rates of depression, conduct disorder, school dropouts, and substance abuse. The causes of ADHD are unknown. Current theories suggest altered brain activity of chemical transmitters such as dopamine and norepinepherine may play a role. This is based on pharmacological observations showing reduction in symptoms in response to stimulant drugs such as Ritalin which augment dopaminergic and noradrenergic activity in relevant brain areas. However, current findings evade simplistic neurochemical explanations.

Keyword: ADHD
Link ID: 1281 - Posted: 01.08.2002

Copyright © 2002 AP Online By PAUL RECER, Associated Press WASHINGTON - Researchers have used embryonic stem cells to relieve symptoms of Parkinson's disease in rats, showing that the cells can be converted to neurons that make dopamine, a key brain chemical. The researchers at Harvard Medical School and McLean Hospital in Belmont, Mass., showed in tests that the cells injected into rats whose brains had been chemically damaged would spontaneously convert to correct the Parkinson's symptoms. Some experts said the study, appearing Tuesday in the Proceedings of the National Academy of Sciences, was significant because it showed embryonic stem cells could be used to treat brain disorders, but they cautioned that the cells also could cause tumors. Copyright © 2001 Nando Media

Keyword: Parkinsons; Stem Cells
Link ID: 1279 - Posted: 06.24.2010

By EMMA ROSS AP Medical Writer LONDON (AP)--Some of the world's leading scientists gathered Monday at Cambridge University to celebrate the 60th birthday of physicist Stephen Hawking, who has survived a remarkable 38 years with motor neuron disease. The university is staging a week of events to honor Hawking, concluding Friday with a symposium celebrating his contributions to fundamental physics and cosmology. His birthday is Tuesday. Hawking, a professor of mathematics at Cambridge and author of ``A Brief History of Time,'' was told he could not expect to live long when he was diagnosed at age 22 with amyotrophic lateral sclerosis, also known as Lou Gehrig's disease. The average survival time is three to five years from the onset of symptoms. © 2002 Cox Interactive Media

Keyword: ALS-Lou Gehrig's Disease
Link ID: 1278 - Posted: 06.24.2010

New Haven, Conn. -- When schizophrenic patients quit smoking, some aspects of their cognitive function become impaired, according to a new study published this month by Yale researchers in the Journal Neuropsychopharmacology. The researchers found that cigarette smoking improves a type of cognitive function called visuospatial working memory (VSWM) in patients with schizophrenia, but that smoking had no beneficial effects, or even negative effects, on this form of cognitive function in healthy subjects without schizophrenia. "This is one of only a few studies to suggest that nicotine has a beneficial effect on spatial working memory, which is known to be impaired in schizophrenic patients," said principal investigator Tony P. George, M.D., assistant professor of psychiatry at Yale School of Medicine and the Connecticut Mental Health Center.

Keyword: Schizophrenia; Drug Abuse
Link ID: 1277 - Posted: 01.08.2002

Researchers isolate neuronal progenitor cells from ESCs By Laura DeFrancesco Two reports in the December issue of Nature Biotechnology show that the potential of human embryonic stem cells is being realized.1,2 One group led by S.C. Zheung at the University of Wisconsin, Madison, and another led by B.E. Reubinoff from Hadassah University, Jerusalem, have isolated highly purified populations of neuronal progenitor cells from human embryonic stem cell (ESC) cultures. These papers demonstrate that human ESC cultures can be enriched for a single and specific progenitor cell type. Furthermore, the cells, which by all measures appear to be neuronal progenitor cells, behave this way in vitro and in vivo, and give rise to the major cell types of the central nervous system (CNS). The Scientist 16[1]:28, Jan. 7, 2002 © Copyright 2002, The Scientist, Inc. All rights reserved.

Keyword: Stem Cells; Regeneration
Link ID: 1276 - Posted: 06.24.2010

Scientists are deducing the internal circuitry of the visual brain by mathematically reproducing the geometric hallucinations people see when they ingest mind-altering drugs, view bright, flickering lights or encounter near-death experiences. The findings by the University of Chicago's Jack Cowan, the University of Utah's Paul Bressloff and three of their colleagues provide new insights into the complexities of vision, the workings of the brain and even the origins of art. "We take it for granted, but seeing is an amazing process," said Cowan, a Professor in Mathematics and Neurology. "In something less than a second, we can see objects and classify them under all kinds of differing illumination from very dim to very bright. We're just scratching the surface of what's going on." Copyright © 1995-2002 UniSci. All rights reserved.

Keyword: Vision
Link ID: 1275 - Posted: 06.24.2010

By TERESA RIORDAN If Maria Rupnick turns out to be right, losing weight may one day become easy for millions of obese people. In laboratory experiments at M.I.T. and the Children's Hospital in Boston, Dr. Rupnick has shown that an entire class of compounds designed to inhibit cancer may also, without any obvious side effects, cause extraordinary weight loss. So far Dr. Rupnick, now a researcher and instructor at Brigham & Women's Hospital in Boston and at Harvard Medical School, has conducted her experiments only in mice — especially so-called ob/ob mice, which are very fat creatures naturally predisposed to eating constantly and thus weighing two to three times as much as a normal mouse. Copyright 2002 The New York Times Company

Keyword: Obesity
Link ID: 1274 - Posted: 06.24.2010

The Army could have a new “offensive” weapon in their arsenal before long. One that really stinks! Department of Defense officials have asked researchers at the Monell Chemical Senses Center in Philadelphia to create a universally offensive odor that can be used by the military for, among other things, crowd control, according to an article in the January 7 issue of Chemical & Engineering News, the weekly newsmagazine of the American Chemical Society, the world’s largest scientific society. The non-lethal “odor bomb” is said to smell like rotting garbage, human waste and burning hair, according to the article’s author, senior editor Maureen Rouhi, Ph.D. Tests show the putrid odors “are potent in making people want to flee in disgust,” notes the article. The odors also cause shallow breathing, increased heart rate and can lead to nausea, it adds. The researchers focused on biological odors “because we thought those had the best chance of being recognized universally,” says Monell researcher Pamela Dalton, Ph.D. “People really hated these odors,” she adds.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 1273 - Posted: 06.24.2010

Dyslexia could be linked to low blood pressure Many dyslexic children come from families with a history of lower blood pressure - adding weight to theories of a common cause of the disorder. The origins of the learning disability - which causes children to have poor reading skills - are a mystery to doctors. It has been suggested that as many as 10% of UK children may suffer from dyslexia in some form. And many doctors believe that its cause is at least partly due to physical differences in the brain. (C) BBC

Keyword: Dyslexia
Link ID: 1272 - Posted: 01.07.2002

By MARC LACEY KISII, Kenya, Jan. 5 — Pacifica Kemunto used to preside over a booming business from the fertile hillside near here, where she has spent all of her 80 or so years. Customers would line up for her services. With the profits she earned, she built a spacious mud hut with a tin roof that was the envy of the village. But Mrs. Kemunto's profession is no longer the revered calling it once was. Her grandmother had done the same job. So had a cousin on her mother's side. Mrs. Kemunto laments, however, that she may be the last one in the family to devote her life to what she calls the circumcision of young girls. Cutting a girl's genitals is now banned in Kenya.

Keyword: Sexual Behavior
Link ID: 1271 - Posted: 06.24.2010

Copyright © 2002 Scripps Howard News Service By RYAN ALESSI, Scripps Howard News Service WASHINGTON - It's hard to imagine ever forgetting the events of Sept. 11. Even months later, the slow-motion clips of the World Trade Center towers crumbling still seem just as frightening as they were that day. But psychologists question how accurately the human memory can recall details of such a traumatic event that galvanized the nation in terror the way Pearl Harbor, John F. Kennedy's assassination and the Challenger explosion had before. And by learning more about how the mind processes and stores information about such dramatic "flashbulb" events, as they're called, psychologists hope to develop better ways to help us cope. Copyright © 2001 Nando Media

Keyword: Learning & Memory; Stress
Link ID: 1270 - Posted: 06.24.2010

Relapse after treatment is common in schizophrenics An anti-psychotic drug has shown encouraging signs of helping to reduce the risk of relapse in schizophrenia patients. A report in the New England Journal of Medicine found the one-year rate of relapse for patients taking risperidone was about 25%. The same rate of relapse for patients taking the old generation haloperidol was about 50%. Scientists believe risperidone could help counter the huge cost to the health system of psychotic relapse, which is common among schizophrenic patients. (C) BBC

Keyword: Schizophrenia
Link ID: 1268 - Posted: 01.06.2002

Researchers move beyond the basics to better understand the differences between men and women By Karen Young Kreeger When I was a kid, I always wanted to know why there were two sexes," recalls Florence Haseltine , director of the Center for Population Research at the National Institute of Child Health and Human Development. "From the time I was 4, I used to drive my father crazy. He said, 'Well, when you grow up, you figure it out.'" Haseltine, who has devoted much of her career to pursuing such questions, was heartened last April when the Institute of Medicine validated this budding area of investigation by issuing its report, "Exploring the Biological Contributions to Human Health: Does Sex Matter?"1 The IOM's overwhelming conclusion: it most certainly does. But to what extent, and how? The most often studied differences are in the reproductive system. However, over the past 20 years, and most rapidly in the last 10, scientists have accumulated data on differences between the sexes at many levels, from the cellular to the behavioral, from the clinical to the pharmaceutical. For example, health educators have been trying for years to tell the public about sex differences in heart disease using the general media: on average, men experience heart attacks 10 years earlier than women, and have a better rate of survival after one year. Symptoms also vary by sex: women experience shortness of breath, fatigue, and chest pain; most male heart attacks come on as a sudden, striking pain in the chest. The Scientist 16[1]:35, Jan. 7, 2002 © Copyright 2002, The Scientist, Inc. All rights reserved.

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 1267 - Posted: 06.24.2010

Debate fires stoked again with recent findings By Hal Cohen In his most recent paper,1 Pasko Rakic , chairman of the neurobiology department at Yale University, has rekindled a debate over whether neurogenesis occurs in the neocortex of the normal adult primate. This 'he-said, she-said' battle began in 1985, when Rakic published a study of rhesus monkeys2 and stated unambiguously that neurons were not born in any animal's brain after infancy. Contradicting Rakic's findings in 1998 was neuroscientist Elizabeth Gould, Princeton University, who used a new labeling technique to show that the adult marmoset brain generated neurons.3 The following year she published findings that some neurons were made in the neocortex, which is home to higher cognitive functions such as language and complex thought in primates.4 Rakic looked for new neurons in adult macaque monkeys by labeling neuronal and glial cells with bromodeoxyuridine (BrdU). He found newly generated neurons, which were limited to the hippocampus and olfactory bulb; some BrdU cells were found in the neocortex but were identified to be non-neuronal. The Scientist 16[1]:28, Jan. 7, 2002 © Copyright 2002, The Scientist, Inc. All rights reserved.

Keyword: Neurogenesis
Link ID: 1266 - Posted: 06.24.2010

Environmental concerns reemerge over steroids given to livestock Janet Raloff Many cattle are fed the same muscle-building androgens—usually testosterone surrogates—that some athletes consume. Other animals receive estrogens, the primary female sex hormones, or progestins, semiandrogenic agents that shut down a female's estrus cycle. Progestins fuel meat-building by freeing up resources that would have gone into the reproductive cycle. While federal law prohibits people from self-medicating with most steroids, administering these drugs to U.S. cattle is not only permissible but de rigueur. So far, almost all concern about this practice has focused on whether trace residues of these hormones in the meat have human-health consequences. But there's another way that these powerful agents can find their way into people and other animals. A substantial portion of the hormones literally passes through the cattle into their feces and ends up in the environment, where it can get into other food and drinking water. From Science News, Vol. 161, No. 1, Jan. 5, 2002, p. 10. Copyright ©2002 Science Service. All rights reserved.

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 1265 - Posted: 06.24.2010

Copyright © 2002 Scripps Howard News Service By LEE BOWMAN Scripps Howard News Service - The critical childhood window for becoming fluent in a language applies to sign language as well as spoken language, according to a new study. Using functional magnetic resonance imaging, the researchers found different patterns of brain activity in bilingual people who learned American Sign Language before puberty and after puberty. Language researchers have long known that children find it much easier than adults, or even teenagers, to acquire a second language because their brains have more connections between neurons. This makes for an easier time incorporating the new language into their brain networks and allows them to think in the language, rather than translate. Copyright © 2002 Nando Media

Keyword: Language
Link ID: 1262 - Posted: 06.24.2010

Goal is to minimize collateral damage and prevent involvement of second eye. The terms "heart attack" and "brain attack" have become commonplace, but now neuro-ophthalmologists are waging war on the all too common, underreported, and untreated condition referred to as "eye attacks." These attacks, known medically as Ischematic Optic Neuropathy ("ION"), result from a sudden lack of blood flow to the eye. Eye attacks, which are usually painless, can develop quite rapidly--sometimes overnight, often with catastrophic consequences to the vision of the individual, such as a sudden and permanent loss of peripheral or central vision in one eye. The resulting visual impairment and the degree of severity usually varies from patient to patient but can include loss of the bottom half of one's vision and difficulty with light and darkness. University of Pennsylvania Medical Center researchers are working to help educate the public about this condition, which is the most common cause of acute optical nerve disease in adults over 50 years of age.

Keyword: Vision; Stroke
Link ID: 1261 - Posted: 01.05.2002

Rachel Nowak, Melbourne By smothering budgerigars in sunscreen, scientists have discovered that the birds use fluorescence to highlight their sexual attractiveness. Neurobiologist Justin Marshall of the University of Queensland in Brisbane and his colleagues used the sunscreen to block the fluorescence of yellow crown and cheek feathers used by the budgies in courtship displays. The team found that budgies preferred the company of control birds, whose crown and cheeks had been smeared with petroleum jelly, which does not block UV light. The preference only existed for birds of the opposite sex, suggesting the fluorescence highlights mating potential. © Copyright Reed Business Information Ltd.

Keyword: Vision; Sexual Behavior
Link ID: 1260 - Posted: 06.24.2010

An investigation of the activity of individual human nerve cells during the act of memory indicates that the brain’s nerve cells are even more specialized than many people think – no pun intended. Although nerve cells that change activity during the use of memory are widely distributed in the brain, individual neurons generally respond to specific aspects of memory. "For the first time, we’ve been able to show differences within regions of the temporal lobe in the way individual neurons respond to memory. Everything we’ve done to this point was to show that there are individual neurons that change activity --but we hadn’t been able to sort them out in any meaningful way. Now we can," says Dr. George Ojemann, professor of neurological surgery at the University of Washington. The findings appear in the January 2002 issue of Nature Neuroscience.

Keyword: Learning & Memory
Link ID: 1258 - Posted: 06.24.2010