By JOHN NOBLE WILFORD In a new genetic study of modern human origins, an American scientist has found what he says is substantial evidence that could reshape the prevailing "out of Africa" theory. Among his findings, he says, is the likelihood that genes from Neanderthals and other species live on in present-day humans. The findings apparently do not undermine the "out of Africa" theory, which holds that there was a relatively modern founding migration of human ancestors into Asia and Europe from Africa. But they do suggest that there were at least two migrations rather than one — the first about half a million years ago, the other, as in the "out of Africa" theory, beginning some 100,000 years ago. Copyright 2002 The New York Times Company

Keyword: Evolution
Link ID: 1642 - Posted: 06.24.2010

Early humans came out of Africa again and again. JOHN WHITFIELD There were at least three major waves of early human migration out of Africa, our DNA suggests. Apparently the wanderers made love, not war: gene patterns hint that later emigrants bred with residents. Human origins are contentious. Most researchers agree that there have been several major migrations out of Africa. Some hold that human populations in many regions evolved in parallel after Homo erectus left Africa around two million years ago. Others think that a wave of modern humans from Africa replaced all previous Eurasian populations perhaps as recently as 50,000 years ago. The truth lies somewhere in the middle, proposes geneticist Alan Templeton of Washington University, St Louis1 . "Africans have had a huge genetic impact on humanity," he says. "But my analysis really isn't compatible with complete replacement." Templeton, A. R. Out of Africa again and again. Nature, 416, 45 - 51, (2002). © Nature News Service / Macmillan Magazines Ltd 2002

Keyword: Evolution
Link ID: 1640 - Posted: 06.24.2010

NEW YORK - (Reuters Health) - New research in twins provides more evidence of the unusual link between smoking and a lower risk of Parkinson's disease. But, far from advocating smoking as a way to cut Parkinson's risk, researchers say that understanding the relationship could help identify the cause of Parkinson's and possibly ways to prevent it. For 30 years, various studies have turned up an association between smoking and lower risk of Parkinson's disease, according to the authors of the new study. But a biological explanation has remained elusive, and some have suggested that smoking itself is not protective. Rather, some genetic characteristics may underlie both Parkinson's and the tendency to smoke. SOURCE: Neurology 2002;58:581-588.

Keyword: Parkinsons; Drug Abuse
Link ID: 1639 - Posted: 03.07.2002

New Formula Adds Fatty Acids Thought to Aid Brain, Eye Development By Melinda T. Willis [ABCNEWS.com] — While breast milk is still the best milk for babies, the newest addition to the infant formula family is trying to bridge that gap. Mead Johnson Pharmaceuticals is now marketing a new line of formula in the United States called Enfamil Lipil that contains two fatty acids — decosahexaenoic acid, or DHA, and arachidonic acid, or ARA — that are naturally occurring elements of breast milk and are believed to play an important role in the development of the brain and the eye. "What the formula companies are trying to do is get more and more like breast milk, because they realize that it is the gold standard," says Dr. Steven Zeisel, chairman of the department of nutrition at the University of North Carolina, Chapel Hill. "There is no advantage of this formula over breast milk, but there might be an advantage over other formulas." Copyright © 2002 ABCNEWS Internet Ventures.

Keyword: Development of the Brain
Link ID: 1638 - Posted: 06.24.2010

The cause of a group of brain-attacking diseases, known as spongiform encephalopathies, was once a mystery. Researchers spent years to no avail searching for a bacterium, virus or other typical disease-causing agent. Now increasing research points to an unusual suspect. Many scientists believe that a mere protein, termed a prion protein, is behind these diseases. This discovery is helping researchers get closer to developing treatments for those with the fatal ailments. You open the tainted mail and inhale bacterial spores. Soon flu-like symptoms and breathing problems erupt. It's anthrax. The bacteria behind the anthrax disease, as well as the smallpox virus and plague bacteria, for example, use nucleic acid to take hold of your body. This genetic material carries special codes that allow the microbes to replicate and create overpowering troops that swarm, attack and launch illness. Copyright © 2002 Society for Neuroscience

Keyword: Prions
Link ID: 1637 - Posted: 06.24.2010

The study tested 102 heavy users of the drug Long term marijuana users may have worse memories and poorer attention spans than other users of the drug, scientists say. Memory and attention span got "significantly" worse the longer a user had been taking the drug, according to tests done on those entering a US drugs treatment programme. But it is not clear whether giving up the drug will enable users to recover, and the research fuels the scientific debate over the true impact of marijuana use on the brain. The research - published in The Journal of the American Medical Association (Jama) - shows habitual users may suffer academically, at work and in their interpersonal relationships, its authors say. (C) BBC

Keyword: Drug Abuse
Link ID: 1635 - Posted: 03.06.2002

News-Journal wire services TALLAHASSEE -- Researchers studying Alzheimer's Disease told lawmakers Thursday that they are close to finding the cause of the degenerative disease. The state held its first-ever Alzheimer's Summit at the Capitol at the urging of House Speaker designate Johnnie Byrd, R-Plant City, whose late father suffered from the disease. During the summit a group of scientists from three medical schools and Mayo Clinic Jacksonville discussed the latest theories behind the causes of the disease and what can be done to treat those who suffer from it. © 2002 News-Journal Corporation, news- journalonline.com (SM)

Keyword: Alzheimers
Link ID: 1634 - Posted: 06.24.2010

Michael L Platt Current Opinion in Neurobiology 10.1016/S0959-4388(02)00302-1 Once considered the province of philosophy and the behavioral sciences, the process of making decisions has received increasing scrutiny from neurobiologists. Recent research suggests that sensory judgements unfold through the gradual accumulation of neuronal signals in sensory–motor pathways, favoring one alternative over others. Stored representations of the outcome of prior actions activate neurons in many of these same areas during decision-making. The challenge for neurobiologists lies in deciphering how signals from these disparate areas are integrated to form a single behavioral choice and the mechanisms responsible for selecting the appropriate information upon which decisions should be informed in particular contexts. © Elsevier Science Limited 2002

Keyword: Attention; Animal Communication
Link ID: 1633 - Posted: 06.24.2010

A national expert in child epilepsy claims wrong diagnoses are being made because there are too few consultants who specialise in the condition. The BBC has learned that many areas are without regular visiting clinics by paediatric neurologists. A survey carried out by the British Paediatric Neurologist Association (BNPA) found that one in seven hospitals do not have a visiting clinic because of a lack of consultants. (C) BBC

Keyword: Epilepsy
Link ID: 1632 - Posted: 03.05.2002

By JOHN O'NEIL Muscle tics and attention deficit hyperactivity disorder, commonly called A.D.H.D., often go together, a fact that has complicated treatment. Doctors have worried that the stimulants prescribed for the hyperactivity will worsen the twitching that comes with conditions like Tourette's syndrome. But last week, the journal Neurology released ahead of schedule a study that its authors hope will lay those fears to rest. The study found that both Ritalin, the most common treatment for the hyperactivity disorder, and an alternative medication, clonadine, worked as well at reducing the symptoms of hyperactivity for 136 children with tic disorders as they did for the general A.D.H.D. population. Copyright 2002 The New York Times Company

Keyword: ADHD; Tourettes
Link ID: 1630 - Posted: 03.05.2002

An ambitious project is underway to build the world’s smallest electronic nose. If the project succeeds, it is expected that the technology would have many potential applications in areas such as environmental monitoring, healthcare and food safety. The aim is to combine the odour sensors together with the signal processing components on to a single silicon chip, around a square centimetre in size. The instrument would require very little power and could be held comfortably in the palm of the hand. © The University of Warwick, 2001. All rights reserved

Keyword: Chemical Senses (Smell & Taste); Robotics
Link ID: 1629 - Posted: 06.24.2010

MINNEAPOLIS / ST. PAUL--Researchers at the University of Minnesota department of neurosurgery and Stem Cell Institute (SCI) have demonstrated the ability of transplanted adult stem cells to restore function in laboratory animals with stroke. Stem cells were isolated and expanded from human bone marrow and transplanted into laboratory rats seven days after an ischemic stroke injury to the brain. Before transplantation, rats were unable to properly use forelimbs and hind limbs. Weeks after receiving stem cell transplants, the animals regained proper use of their limbs. The study is reported in the March 2002 issue of Experimental Neurology. Walter Low, Ph.D., a professor of neurosurgery, was the principal investigator for the study. Other investigators were Li-Ru Zhao, M.D., a research associate in the department of neurosurgery, Catherine Verfaillie, M.D., director of the Stem Cell Institute, and Morayma Reyes, a medical and doctoral student in the Medical School. Previous studies from these investigators demonstrated that adult stem cells isolated from human bone marrow could be induced to differentiate into different types of cells when grown in tissue culture. In the present study, the transplanted stem cells were found to develop into cells that exhibited the characteristics of neurons, astrocytes, and oligodendroglia, the major types of cells found within the brain.

Keyword: Stroke; Stem Cells
Link ID: 1628 - Posted: 03.05.2002

COLUMBUS, Ohio - Certain species of salamanders and lizards can actually hear through their lungs, according to a new study at Ohio State University. The research extends previous studies showing that some types of earless frogs and toads use their lungs to pick up sound vibrations, said Thomas Hetherington, an associate professor of Evolution, Ecology and Organismal Biology at Ohio State. The results of the current study suggest lung-based hearing may exist in a variety of land-based animals. "This primitive system of hearing may have been the auditory system for the first animals that lived on land," Hetherington said. "And it appears that it may still be important for some species today, particularly ones that lack middle ears."

Keyword: Hearing; Evolution
Link ID: 1627 - Posted: 03.05.2002

Small doses of ecstasy can cause brain damage, with scientists warning the drug has the potential to cause memory loss and psychological problems. Major health problems could be expected in the future for ecstasy users, University of Adelaide researcher Rod Irvine has found. Small doses could cause harm and the drug seemed to work on one main type of brain cell, he said. © 1997-2001 ninemsn Pty Ltd - All rights reserved

Keyword: Drug Abuse
Link ID: 1626 - Posted: 06.24.2010

Exclusive from New Scientist Print Edition Colour-changing frog cells could be used to detect performance-enhancing drugs and leave cheating athletes red-faced. Sensors based on the cells can pick up traces of drugs in body fluids, and could even detect new drugs that other methods fail to pick up. Some frogs, such as the African clawed frog (Xenopus laevis), change colour to cope with sunlight and heat and also to improve their camouflage. They do this by activating cells in their skin that contain granules of melanin, the dark brown pigment. These colour-changing cells, called melanophores, are normally dark but can be triggered by a particular hormone released in the frog. When the hormone binds to the cell wall, it sets off a reaction that moves the pigment granules to the centre of the cell, making it look colourless. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse
Link ID: 1625 - Posted: 06.24.2010

Parent survey connects snoring and sleepiness with attention and hyperactivity issues ANN ARBOR, MI – Children who snore often are nearly twice as likely as other children to have attention and hyperactivity problems, and the link is strong for other sleep problems, a new University of Michigan Health System study finds. The results, published in the March issue of the journal Pediatrics, provide some of the most solid evidence ever of a link between sleep problems and behavior. The link is strongest in boys under 8 years of age; habitual snorers in this group were more than three times more likely than non-snorers to be hyperactive. The study, based on a survey of the parents of 866 children that was conducted in the waiting rooms of U-M pediatrics clinics, is among the largest ever to explore the connection between sleep and inattention/hyperactivity. While the study does not provide any clues as to whether and how sleep problems might contribute to behavior issues, or vice versa, the evidence of a link between the two is strong enough to warrant further and thorough investigation, says lead author Ronald Chervin, M.D., M.S., director of the Michael S. Aldrich Sleep Disorders Laboratory and associate professor of neurology at the U-M Medical School.

Keyword: ADHD; Sleep
Link ID: 1624 - Posted: 06.24.2010

Since its introduction in 1985, researchers have used transcranial magnetic stimulation as a research tool to gain many insights into the physiology of the brain. Now, increasing research suggests that the technique, which uses a powerful electromagnet discharge to alter brain activity, may also hold promise as a treatment. Research indicates that those with depression and a variety of other brain illnesses may benefit. Day after day, you pay little attention to the strawberry magnet that keeps your grocery list neatly tacked to the fridge. But now, following a series of careful studies, neuroscientists report that some magnets and the special forces they produce deserve a second look. Specifically, research indicates that powerful magnetic fields used in a technique known as transcranial magnetic stimulation, or TMS, can alter and sometimes aid brain activity. The findings are leading to: * A better understanding of the effect of magnetic fields on the brain. * New ideas on how to treat brain illnesses, such as depression. Copyright © 2002 Society for Neuroscience

Keyword: Brain imaging; Miscellaneous
Link ID: 1622 - Posted: 06.24.2010

Imagine never being able to communicate with your child - him unable to speak and your words muddled by his brain. BBC News Online's Jane Elliott talked to one family about their son's battle to 'talk'. Every new parent longs for the thrill of their child's first word but this was a joy Sarah Harris never thought she would experience when her son Joe was diagnosed with an extremely rare metabolic disorder at the age of two. Doctors told her that her son, Joe, was suffering from Hartnup Syndrome - a condition which meant that, in his case, he would neither be able to speak nor understand speech. Five years later, however, the boy stunned his family and the medical world with a message that proved that he had secretly taught himself to read.

Keyword: Language; Genes & Behavior
Link ID: 1621 - Posted: 03.03.2002

MIKE JOHNSTON For nearly 40 years, one of the windows on life — the sense of hearing — has been closed tight to Nora Robbins. Robbins, who lives with her husband, Jerry, off Robinson Canyon Road, had her hearing tested as a young child and was found to be profoundly deaf. She relies on lip reading and powerful hearing aids to help her stay aware of her surroundings at work, at home and in the community. At 46, she said she hasn’t withdrawn from life, yet acknowledges the loss of hearing has taken from her some important aspects of life. ©2001 MyWebPal.com. All rights reserved.

Keyword: Hearing
Link ID: 1620 - Posted: 06.24.2010

Bruce Bower Mental-health workers have long theorized that it takes grueling emotional exertion to recover from the death of a loved one. So-called grief work, now the stock-in-trade of a growing number of grief counselors, entails confronting the reality of a loved one's demise and grappling with the harsh emotions triggered by that loss. Two new studies, however, knock grief work off its theoretical pedestal. Among bereaved spouses tracked for up to 2 years after their partners' death, those who often talked with others and briefly wrote in diaries about their emotions fared no better than their tight-lipped, unexpressive counterparts, according to psychologist Margaret Stroebe of Utrecht University in the Netherlands and her colleagues. In most cases, "the bereaved have to cope with their loss in their own time and their own way," the researchers conclude in the February Journal of Consulting and Clinical Psychology . "There was no evidence that talking about the loss with others and disclosing one's emotions facilitated [psychological] adjustment." From Science News, Vol. 161, No. 9, March 2, 2002, p. 131. Copyright ©2002 Science Service. All rights reserved.

Keyword: Emotions
Link ID: 1619 - Posted: 06.24.2010