Although recent reports on mercury have focused on the dangers to humans, some researchers feel that public health could be better guarded if standards were enforced that protect wildlife. Gary Heinz, a research biologist with the U.S. Geological Survey (USGS) at the Patuxent Wildlife Research Center in Laurel, Md., has found that some bird species are much more sensitive than humans to mercury. “To a large extent, researchers in human toxicology ignore the work that is being done in wildlife toxicology,” he says. “The reverse is also unfortunately true.” Human dietary guidelines for mercury range from a high of 1.0 parts per million (ppm) in the United States to a low of 0.4 ppm in Japan. However, birds can show ill effects at much lower dietary concentrations than humans. Mallard ducks, for instance, experience harmful influences to eggs when fed as little as 0.1 ppm of methylmercury, and ring-necked pheasant show effects at 0.2 ppm. Yet, only four species of birds have been well studied, because captive breeding experiments with wild animals are both daunting and expensive, say USGS researchers. Heinz has used direct injection of methylmercury into eggs as a quick and effective means to test chick mortality in 20 bird species. While mallards have increased chick mortality at 0.8–1.0 ppm, the most sensitive species is the white ibis, whose chicks begin dying at methylmercury concentrations of only 0.1 ppm. He also notes that these are mercury levels that birds are likely to encounter in the wild. Copyright © 2004 American Chemical Society

Keyword: Neurotoxins
Link ID: 6421 - Posted: 06.24.2010

David Berlinski At some time in the history of the universe, there were no human minds, and at some time later, there were. Within the blink of a cosmic eye, a universe in which all was chaos and void came to include hunches, beliefs, sentiments, raw sensations, pains, emotions, wishes, ideas, images, inferences, the feel of rubber, Schadenfreude, and the taste of banana ice cream. A sense of surprise is surely in order. How did that get here? If the origin of the human mind is mysterious, so too is its nature. There are, Descartes argued, two substances in the universe, one physical and the other mental. To many contemporary philosophers, this has seemed rather an embarrassment of riches. But no sooner have they ejected mental substances from their analyses than mental properties pop up to take their place, and if not mental properties then mental functions. As a conceptual category, the mental is apparently unwilling to remain expunged. And no wonder. Although I may be struck by a thought, or moved by a memory, or distracted by a craving, these familiar descriptions suggest an effect with no obvious physical cause. Thoughts, memories, cravings—they are what? Crossing space and time effortlessly, the human mind deliberates, reckons, assesses, and totes things up; it reacts, registers, reflects, and responds. Copyright 2003 Commentary

Keyword: Evolution
Link ID: 6420 - Posted: 06.24.2010

Among the many genes that may contribute to an individual's susceptibility to alcoholism, those in the dopamine system are of special interest because addictive substances can activate this system. In particular, brain-derived neurotrophic factor (BDNF) can influence both dopamine and serotonin neurotransmitters, which are heavily linked to addiction. New findings, published in the November issue of Alcoholism: Clinical & Experimental Research, suggest that variants of the BDNF gene may not only play a role in a person's committal of violence while intoxicated, but may also play a role in vulnerability to alcohol withdrawal-associated delirium tremens. "The cell bodies of the dopamine system originate in the ventral tegmental area and send projections to the dopamine receptors in the nucleus accumbens and basal forebrain," said Sachio Matsushita, chief of psychiatry at the National Hospital Organization in Kanagawa, Japan and first author of the study. "Alcohol can activate this system. For example, alcohol consumption increases dopamine release in the nucleus accumbens from ventral tegmental neurons. Furthermore, animal studies have shown that BDNF influences both dopamine and serotonin levels." These and other results led Matsushita and his colleagues to investigate the role of BDNF in certain characteristics of alcoholics.

Keyword: Drug Abuse; Trophic Factors
Link ID: 6419 - Posted: 11.15.2004

Italy is considering screening all newborn babies for heart abnormalities after the initial results of a pilot study suggested this could prevent up to 30 deaths in infancy and childhood in the country each year. The aim of the pilot study is to screen 50,000 newborns. Based on the 21,000 screened so far, and an ongoing genetic study, the team calculates that between 10 and 15 per cent of all cases of sudden infant death syndrome (SIDS) are due to fatal heart rhythms, meaning identifying and treating these babies might prevent more than a tenth of the 300 SIDS cases per year in Italy. “The critical issue is that some of these are avoidable deaths,” says the lead researcher Peter Schwartz at the University of Pavia. Schwartz presented his latest findings at the American Heart Association’s meeting in New Orleans this week. He has been arguing for national screening programmes since 1998, when his team published a controversial paper suggesting that many SIDS cases are caused by a rare inherited condition called long QT syndrome. This causes abnormal heart rhythms that can kill without leaving any clue to the cause of death. © Copyright Reed Business Information Ltd.

Keyword: Sleep; Development of the Brain
Link ID: 6418 - Posted: 06.24.2010

Current debates about marriage of same-sex couples often lead to discussions regarding the health and well-being of any children involved in such relationships. Although considerable research on young children of same-sex couples finds they fare as well as their peers with opposite-sex parents, there have been fewer studies of adolescents. We examined romantic relationships, school adjustment, and psychological well-being among 44 adolescents whose mothers had same-sex romantic partners, comparing them to 44 adolescents whose mothers had opposite-sex partners. Our study also examined the association between the quality of parental/adolescent relationships and school achievement and psychological well-being. We drew information for our study from the National Longitudinal Study of Adolescent Health, in which researchers conducted interviews with and collected information from thousands of American adolescents and their parents. The two groups we studied had several similar characteristics, including age, gender, ethnicity, level of parental education, and family income. There was an equal number of girls and boys, and an overall average age of 15. We found that adolescents whose parents had same-sex romantic partners were developing in positive ways. We found no significant differences in their school achievement or psychological well-being when compared to their peers with male/female parents.

Keyword: Sexual Behavior; Development of the Brain
Link ID: 6417 - Posted: 11.15.2004

The illnesses suffered by veterans of the first Gulf War appeared to be linked to toxins including nerve gas, according to a US report. The US Veterans Affairs Department said stress or mental illness did not explain most veterans' complaints, but there was a probable link to toxins. British campaigners are demanding the government recognise "Gulf War Syndrome". The UK's Ministry of Defence (MoD) says there is not enough evidence to prove its existence. The report, by the Research Advisory Committee on Gulf War Veterans' Illnesses, said up to 30% of US Gulf War veterans had been afflicted by a "complex of multiple chronic symptoms over and above expected rates seen in veterans who did not serve in the Gulf War". "A growing body of research indicates that an important component of Gulf War veterans' illnesses is neurological in character. It added: "Evidence supports a probable link between exposure to neurotoxins and the development of Gulf War veterans' illnesses." It found veterans had developed Lou Gehrig's disease at about twice the rate of veterans who did not serve in the Gulf War. Symptoms include headaches, memory problems, confusion, dizziness, blurred vision and tremors. It said reports indicated a large number of Gulf War troops were exposed to a variety of potentially toxic substances, including low levels of chemical nerve agents, pills taken to protect veterans from the effects of nerve agents and insect repellents and pesticides, that can adversely affect the nervous system. The Pentagon has previously acknowledged that some troops may have been exposed to the nerve agent sarin when Iraqi munitions were destroyed. The MoD said it was aware of most of the material in the report. (C)BBC

Keyword: Neurotoxins
Link ID: 6416 - Posted: 11.13.2004

By SCOTT SHANE The government will spend $15 million over the next year for research on the illnesses of veterans of the 1991 Persian Gulf war, the secretary of veterans affairs, Anthony J. Principi, announced Friday. He said it would concentrate on the role of neurotoxins, and not the stress and psychological conditions often implicated as a cause of the veterans' health complaints. Mr. Principi also said the department would establish a research center to develop treatments for gulf war illnesses. "The men and women who fought there deserve our undivided attention to their questions, to their symptoms, to their futures," he said. "They have been frustrated far too long." He said his decision was guided by the findings of a committee of scientists and veterans that he appointed in 2002 to study the ailments of thousands of servicemen and women that persisted after the war. In a report released at a news conference here, the panel, the Research Advisory Committee on Gulf War Veterans' Illnesses, broke with earlier study groups by pointing to chemical exposures during the war, not the effects of combat stress, as the primary cause of what has sometimes been called Gulf War Syndrome. Copyright 2004 The New York Times Company

Keyword: Neurotoxins
Link ID: 6415 - Posted: 11.13.2004

By Jennifer Viegas, Discovery News — When killer whales sound off, mammals listen, according to a recent study that found seals, sea lions, dolphins, porpoises and other marine mammals eavesdrop on the killer whales that like to eat them. The study suggests some animals pay attention to other animals communicating when it is in their best interests to listen to the enemy. It also reveals how call patterns of animals can co-evolve because of eavesdropping. Marine biologists conducted the extensive study from 1999-2003 in Johnstone and Queen Charlotte Straits, British Columbia, and in Glacier Bay, Icy Strait and Stephens Passage, southeastern Alaska. From a boat or from an elevated point on shore, the scientists used binoculars to locate transient and killer whales and then followed them by boat. An underwater microphone called a hydrophone picked up the whale calls. The findings are published in the current journal Animal Behavior. Although the two types of whales are from the same species, Orcinus orca, they have very different lifestyles. According to the research, resident killer whales live in large, stable groups and feed only on fish, especially Pacific salmon. Copyright © 2004 Discovery Communications Inc

Keyword: Hearing
Link ID: 6414 - Posted: 06.24.2010

Scientists target drugs and other environmental agents that may play a role Diana Parsell Beth Crowell remembers the day in 1989 when her triplets, Casey, Andrew, and Erin, were about 15 months old. Crowell put Erin down on the floor to crawl. "But she just sat there, fixated on the red shag carpeting," says the Housatonic, Mass., mother of four. The toddlers were often sick, and "none of them made eye contact," Crowell recalls. A medical evaluation was devastating: All three babies had autism. Children with autism typically have trouble communicating, interacting socially, and controlling their behavior. Those most severely affected seem to live in a world of their own. Various treatments sometimes reduce symptoms, especially if children are diagnosed early. But there is no cure for autism, which has baffled the medical community since the disorder was first described in 1943. The Centers for Disease Control and Prevention (CDC) recently estimated that 1 of every 1,000 children may have autism, or 1 in 500 if those with autism-related disorders such as Asperger syndrome are included. For years, Crowell combed the medical literature trying to figure out what might have gone wrong in her triplets. She doubted that a genetic mutation was solely responsible. Crowell came to suspect that terbutaline, a drug she had taken during pregnancy to prevent premature labor, might have played a role. A team of researchers in Baltimore found her assertion plausible. They knew of experiments showing that rats exposed to terbutaline before birth had brain abnormalities. More recently, they completed a yet-unpublished clinical study that found a higher-than-expected incidence of autism in both children in sets of fraternal twins whose mothers also took terbutaline during pregnancy. The investigators are Andrew Zimmerman of the Kennedy Krieger Institute, independent researcher Susan Connors, and researchers at Johns Hopkins Medical Institutions. Copyright ©2004 Science Service.

Keyword: Autism; Neurotoxins
Link ID: 6413 - Posted: 06.24.2010

Adults with Asperger Syndrome strive to fit in BY KATHLEEN O'BRIEN Geeky. Clueless. Loner. Loser. Just plain odd. All their lives, they have heard these words and society's ruthless verdict that, try as they might, they can never achieve that indefinable state of "fitting in." Finally these people are hearing a new word: Asperger's. At long last, medicine has a label for their quirks. "Before I got a diagnosis, even I thought I was crazy," said one man attending a Middlesex support group. "I thought I was weird, strange. And I didn't know why." Asperger Syndrome is a neuro-biological disorder, a specific form of high-functioning autism in which the individual has difficulty picking up social cues from others. It accounts for roughly 9 percent of autism cases, according to the New Jersey Center for Outreach and Services to the Autism Community. Males are four times as likely to have the lifelong disorder as females. Unlike the classically autistic, however, "Aspies," as some of them like to call themselves, are highly verbal. Often they can't stop talking about bizarrely narrow pet interests. Copyright 2004 NJ.com

Keyword: Autism
Link ID: 6412 - Posted: 11.13.2004

By Paul Rincon A new nanotechnology-based technique could lead to a test for diagnosing the early signs of Alzheimer's disease. The Bio-Barcode-Assay can recognise ADDL, a protein that accumulates in the brains of sufferers. It is a million times more sensitive than conventional tests and could revolutionise disease detection. In future, it might form the basis not only of a test for Alzheimer's but also for types of cancer, the human form of mad cow disease and HIV. Doctors currently have no way of diagnosing Alzheimer's disease in their patients. The disease can only be confirmed after death, by studying brain tissue. "Diagnosis [of Alzheimer's] is 100% accurate post-mortem. What you want is the ability to detect the marker so you can begin to think about new types of therapies," said Professor Chad Mirkin, of Northwestern University in Evanston, US. Professor Mirkin and his research group at Northwestern developed the highly sensitive test by manipulating molecules at the nanometre scale (one billionth of a metre). "We have done the first set of experiments that quantify the number of ADDLs in cerebrospinal fluid," Professor Mirkin said. (C)BBC

Keyword: Alzheimers
Link ID: 6411 - Posted: 11.12.2004

About 30,000 years ago, prehistoric humans seemed to wake up from a slumber and start developing a complex culture. To what do we owe this change? Grandmothers. Rachel Caspari, an anthropologist at the University of Michigan, used fossil records to examine teeth—an indicator of age—in 768 ancient skulls, and was able to estimate the age distributions of prehistoric populations. She studied some from two million years ago and found one older Australopithecine skull for every ten young ones. This ratio jumped to one in five in the early Homo species, and again to four in ten in the Neanderthals. Then, at around 30,000 years ago, Caspari saw two older adults for very one young adult. Caspari chalks the change up to what scientists call the "grandmother hypothesis," which ties jumps in life expectancy to post-menopausal women who, free from caring for their own children, nurture their grandchildren. "The grandmother hypothesis was developed to explain why women have menopause, why humans live beyond their reproductive age," says Caspari. "Humans are unique in that. We're certainly unique among primates in which people live longer than they reproduce. And the suggestion has been that they do that because their grandmothers—post-menopausal women—help keep their kin alive. They contribute a lot to their daughter's families and that increases their reproductive success. They allowed more grandchildren to survive, to reproduce, and they were able to transmit social information that was really important for those groups—who their close kin were, who their enemies were, who their alliances were supposed to be with. They were also able to transmit stories and art and all sorts of things to the next generation." © ScienCentral, 2000- 2004.

Keyword: Evolution
Link ID: 6410 - Posted: 06.24.2010

Malnutrition in the first few years of life leads to antisocial and aggressive behavior throughout childhood and late adolescence, according to a new University of Southern California study. "These are the first findings to show that malnutrition in the early postnatal years is associated with behavior problems through age 17," said Jianghong Liu, a postdoctoral fellow with USC's Social Science Research Institute and the lead author of the study published in the American Journal of Psychiatry's November issue. "Identifying the early risk factors for this behavior in childhood and adolescence is an important first step for developing successful prevention programs for adult violence," she said. For 14 years, researchers followed the nutritional, behavioral and cognitive development of more than 1,000 children who lived on Mauritius, an island in the Indian Ocean off the coast of Africa. The sample of boys and girls included children with Indian, Creole, Chinese, English and French ethnicities.

Keyword: Development of the Brain; Aggression
Link ID: 6409 - Posted: 11.12.2004

A common class of drugs prescribed to children with depression may have an adverse effect on bone growth, according to a study published online in the journal Endocrinology by researchers at the Indiana University School of Medicine. Researchers looked at the effect of selective serotonin-reuptake inhibitors (SSRIs) on bone accrual in growing mice. The findings showed a reduction in bone mass and size in the mice administered an SSRI. "These findings indicate a potential negative impact of SSRIs on the skeleton and point to a need for further research into the prescribing of these drugs to children and adolescents," said lead author Stuart J. Warden, P.T., Ph.D., assistant professor in the Department of Physical Therapy, IU School of Health and Rehabilitation Sciences. The study investigated the effects of fluoxetine, more commonly known as Prozac®, on bone growth in young mice. Dr. Warden and his colleagues selected fluoxetine because it is the only prescription antidepressant currently approved by the FDA for children and adolescents. IU researchers began their investigation after preliminary clinical evidence released in other studies showed that SSRI use has been associated with increased bone loss at the hip in elderly women, decreased bone density among men and decreased skeletal growth in children.

Keyword: Depression; Development of the Brain
Link ID: 6408 - Posted: 11.12.2004

Stress really can cause miscarriages, a series of studies suggests. The good news is that extra doses of progesterone might safeguard the pregnancies of women at risk. While the cause of most miscarriages is never established, doctors usually attribute them either to abnormalities in the fetus or to illness or health problems in the mother. Most obstetricians dismiss the idea that healthy women can lose healthy babies solely because of stress. But a series of studies by a team in Germany might change their minds. “We can clearly say that stress has a major impact on pregnancy maintenance,” says team leader Petra Arck of Charité, an institute of the University of Berlin. The team has shown that when pregnant mice are deliberately stressed by factors such as loud noise levels, this creates hormonal imbalances that make the immune system more hostile to the fetus. It then attacks the placenta. “That leads to rejection of the fetus because the blood supply can’t be sustained,” says Arck. The chain of events uncovered by her team starts with the release of stress hormones such as cortisol. As cortisol levels rise in the bloodstream, they suppress the production of progesterone, a hormone that is crucial to maintaining a healthy pregnancy. © Copyright Reed Business Information Ltd.

Keyword: Stress; Hormones & Behavior
Link ID: 6407 - Posted: 06.24.2010

Jim Giles People with genes thought to protect against variant Creutzfeldt-Jakob disease (vCJD) may still be at risk of developing some strains of the illness, animal studies suggest. All of the 146 British people who have died from vCJD, which is thought to be caused by eating meat infected with the prion protein that causes mad cow disease, have a genetic variation known as MM. This led some researchers to hope that people with different variants, who make up 60% of the population, may be protected from the disease. But mice with such supposedly protective genes still seem to be susceptible to infection with the rogue protein, report John Collinge and colleagues at University College London in a paper published online by Science1. Researchers are cautious about the study's implications for humans, but say that it adds weight to the possibility that tainted beef could have infected more people than was originally thought. "In future we might see different types of CJD," predicts Markus Glatzel, who studies the disease at the University of Zurich in Switzerland. "This is a very important study." ©2004 Nature Publishing Group

Keyword: Prions
Link ID: 6406 - Posted: 06.24.2010

Roxanne Khamsi Would Elgar's Pomp and Circumstance or Debussy's Clair de Lune have sounded the same if the composers had been born in different countries? Probably not, according to researchers who have found that the melodies composers write are influenced by the language they speak. The team's analysis shows that fluctuations in pitch in music written by classic French composers vary much less than in British music. The difference mirrors the patterns of pitch found in the corresponding languages. Musicologists and linguists have tried to connect cultures' speech with their music in the past but have only had luck with tonal languages, such as Chinese, which assign meaning to words based on their pitch. The new work is the first to connect melody with non-tonal speech. Aniruddh Patel of The Neurosciences Institute in La Jolla, California, and his colleagues used advanced computer software to analyse recordings of people saying different sentences in British English and in French. The software measures the pitch of each vowel, then works out the size of the jump in pitch between one syllable and the next. For example, in the word "finding", the second vowel typically registers about 4 semitones higher than the first. ©2004 Nature Publishing Group

Keyword: Hearing; Language
Link ID: 6405 - Posted: 06.24.2010

Oxford University has won its bid for the renewal of an injunction against animal rights activists protesting next to its new animal testing centre. It asked the High Court to extend a 45m "no harassment" zone around its research laboratory, claiming work was stopped because of intimidation. The university had also requested an injunction against 10 named defendants. University chiefs had offered to provide a demonstration area opposite the South Parks Road site. Oxford University Vice-Chancellor, Dr John Hood, said on Wednesday: "As an academic institution, freedom of speech within the law is highly valued. By obtaining this injunction, the University of Oxford is not seeking to stifle the views of those groups and individuals with whom we disagree. "Indeed, we are satisfied that this order strikes a fair balance between the legitimate right to protest and the right of individuals to conduct their lawful business without fear of intimidation or violence." Work on the construction of the laboratory was forced to stop on 13 July after contractors complained they had been harassed and intimidated by some animal rights activists. (C)BBC

Keyword: Animal Rights
Link ID: 6404 - Posted: 11.11.2004

By Rossella Lorenzi, Discovery News — Dolphins and humans share a similar brain size, according to the first map of cetacean brain evolution over the past 47 million years. Experts have long known that toothed whales boast exceptionally large brains. Some species, including the famously bright dolphins, have capabilities previously only ascribed to humans and, to some extent, other great apes. For instance, dolphins can recognize themselves in mirrors and understand symbol-based communication systems and abstract concepts. Such intelligence is probably due their big brains, but the evolution of such brains has remained a mystery. To investigate this question, Lori Marino, from Emory University in Atlanta, and colleagues carried out the largest fossil study ever done on animals, searching museum collections for four years. The team, whose research will be appear in the December issue of The Anatomical Record, tracked down 66 fossilized cetacean skulls. Copyright © 2004 Discovery Communications Inc

Keyword: Evolution
Link ID: 6403 - Posted: 06.24.2010

A device that automatically moves electrodes through the brain to seek out the strongest signals is taking the idea of neural implants to a new level. Scary as this sounds, its developers at the California Institute of Technology in Pasadena say devices like this will be essential if brain implants are ever going to work. Implants could one day help people who are paralysed or unable to communicate because of spinal injury or conditions such as amyotrophic lateral sclerosis (Lou Gehrig’s disease). Electrodes implanted in the brain could, in principle, pick up neural signals and convey them to a prosthetic arm or a computer cursor. But there is a problem. Implanted electrodes are usually unable to sense consistent neuronal signals for more than a few months, according to Igor Fineman, a neurosurgeon at the Huntington Hospital, also in Pasadena. This loss of sensitivity has a number of causes: the electrodes may shift following a slight knock or because of small changes in blood pressure; tissue building up on the electrodes may mask the signal; or the neurons emitting the signals can die. To get around these problems, Joel Burdick and Richard Andersen at Caltech have developed a device in which the electrodes sense where the strongest signal is coming from, and move towards it. Their prototype, which is mounted on the skull, uses piezoelectric motors to move four electrodes independently of each other in 1-micrometre increments. © Copyright Reed Business Information Ltd.

Keyword: Robotics; ALS-Lou Gehrig's Disease
Link ID: 6402 - Posted: 06.24.2010