Most Recent Links

Follow us on Facebook or subscribe to our mailing list, to receive news updates. Learn more.


Links 22941 - 22960 of 29375

The US military is funding development of a weapon that delivers a bout of excruciating pain from up to 2 kilometres away. Intended for use against rioters, it is meant to leave victims unharmed. But pain researchers are furious that work aimed at controlling pain has been used to develop a weapon. And they fear that the technology will be used for torture. "I am deeply concerned about the ethical aspects of this research," says Andrew Rice, a consultant in pain medicine at Chelsea and Westminster Hospital in London, UK. "Even if the use of temporary severe pain can be justified as a restraining measure, which I do not believe it can, the long-term physical and psychological effects are unknown." The research came to light in documents unearthed by the Sunshine Project, an organisation based in Texas and in Hamburg, Germany, that exposes biological weapons research. The papers were released under the US's Freedom of Information Act. One document, a research contract between the Office of Naval Research and the University of Florida in Gainesville, US, is entitled "Sensory consequences of electromagnetic pulses emitted by laser induced plasmas". It concerns so-called Pulsed Energy Projectiles (PEPs), which fire a laser pulse that generates a burst of expanding plasma when it hits something solid, like a person (New Scientist print edition, 12 October 2002). The weapon, destined for use in 2007, could literally knock rioters off their feet. © Copyright Reed Business Information Ltd.

Keyword: Pain & Touch
Link ID: 6983 - Posted: 06.24.2010

By Rossella Lorenzi, Discovery News — Measurements of Michelangelo's David have shown that all is normal in the naked marble man, though he could have been a little better endowed. The towering sculpture acclaimed for its depiction of male physical perfection, has always been the subject of jokes among Florentines and tourists for the modest dimensions of his "pisello." But according to a study to be published at the end of this month by the Dutch Institute for Art History, in Florence, David's genitals are anatomically correct for a male body in a "pre-fight tension." Carried by professors Massimo Gulisano and colleague Pietro Bernabei of Florence University during last year's cleaning, the study is the first full anatomical investigation on Michelangelo's masterpiece and debunks long-held assumptions that the 4.34-meter (14-foot)-high statue was out of proportion. "David is not really highly gifted, but he is totally normal. His penis measures 15 cm which, considering the height of the statue, corresponds to 6-7 cm in an adult," Gulisano told Discovery News. Copyright © 2005 Discovery Communications Inc.

Keyword: Stress; Sexual Behavior
Link ID: 6982 - Posted: 06.24.2010

WASHINGTON — Does having a low socioeconomic status (SES) lead to depression or does depression lead a person into poverty? According to a study that examined a database of 34,000 patients with two or more psychiatric hospitalizations in Massachusetts during 1994-2000, unemployment, poverty and housing unaffordability were correlated with a risk of mental illness. This finding is reported on in the current issue of the American Journal of Orthopsychiatry, published by the American Psychological Association (APA). "The poorer one's socioeconomic conditions are, the higher one's risk is for mental disability and psychiatric hospitalization," said author Christopher G. Hudson, Ph.D., of Salem State College. This was found regardless of what economic hardship or type of mental illness the person suffered. SES was assessed on the basis of community income, education and occupational status. The study considered economic stress as one of several possible explanations for the correlation between SES and mental illness, and this was determined by how much the local income income was below the federal poverty level, the rate of unemployment, and an index of rental housing unaffordability. © 2005 American Psychological Association

Keyword: Schizophrenia; Depression
Link ID: 6981 - Posted: 06.24.2010

WASHINGTON -- Two new studies in the current issue of Behavioral Neuroscience present new evidence of how genes may foster two potentially harmful proclivities: one, to nicotine addiction; the other, to aggressively hostile behavior. Behavioral Neuroscience is published by the American Psychological Association (APA). First, behavioral geneticists at the University of Colorado compared the average daily nicotine consumption in mice. Co-author Jerry Stitzel, PhD, and his team found that mice with the "threonine" polymorphism (an alteration to a gene's DNA sequence) in a gene called Chrna4 consumed significantly more nicotine than mice with an alanine polymorphism in the same gene. The authors think that this threonine variation may allow these mice to tolerate higher nicotine levels before experiencing negative nervous-system side effects. Chrna4 (Cholinergic Receptor Nicotinic Alpha4) contains the instructions to build a protein that is part of a receptor that recognizes acetylcholine, a major neurotransmitter that plays a role in the brain's pleasure system and also aids learning and memory, sleep, control of muscle movement, heart rate, blood pressure and more. Because nicotine is chemically very similar to acetylcholine, it binds to the same receptors, including those with the protein made from Chrna4. Thus the nervous system responds to nicotine as if it were acetylcholine. The authors conclude that natural variations in Chrna4 could, by varying how the nicotine receptors works, result in animal-by-animal variation in nicotine tolerance. That may explain why in humans (the gene is found in essentially all animals), CHRNA4 polymorphisms are associated with nicotine dependence.

Keyword: Drug Abuse; Aggression
Link ID: 6980 - Posted: 03.07.2005

The link between secondhand smoke and sudden infant death has been discredited in the last few years in scientific articles paid for and influenced by cigarette manufacturers, according to a new study of once-secret industry documents. The key article, commissioned by Philip Morris and published in a respected pediatric epidemiology journal in 2001, discounts the significance of research showing a link between exposure to secondhand cigarette smoke and sudden infant death syndrome (SIDS). The article has been cited in at least 19 other scientific papers, misleading physicians, their patients and researchers about the risk of secondhand smoke exposure. "Undermining people's understanding of the link between secondhand smoke and SIDS places infants everywhere at increased risk," according to Stanton Glantz, PhD, director of the Center for Tobacco Control Research and Education at UCSF and senior author of the new study analyzing the tobacco company documents. Analysis of the Philip Morris documents shows that the company sought and paid an author to write an article for publication in a scientific journal, guided his writing and suggested changes in his conclusions in order to call into question the published studies showing links between secondhand cigarette smoke and SIDS. The new report was prepared by researchers at UCSF and the U.S. Centers for Disease Control and Prevention (CDC) and appears in the March issue of the journal Pediatrics.

Keyword: Drug Abuse; Development of the Brain
Link ID: 6979 - Posted: 03.07.2005

Nicola Jones The ongoing threat of prion disease was hashed over by a UK government advisory committee this week. They heard evidence from recent studies of these deformed proteins, which cause mad cow disease and its human version, new-variant Creutzfeldt-Jakob disease (vCJD). The committee will use the information to help formulate advice for UK food agencies and blood banks on whether they should take further measures against prion infections. "We have become more rather than less anxious," says Marc Turner from the Scottish National Blood Transfusion Service, Edinburgh. Two people are thought to have died from vCJD after being infected by blood transfusions. There are no documented cases of anyone getting prion disease through surgery, but there remains a theoretical risk. However, several commercial products are in the pipeline to keep surgical steel free of prions and at least one is expected to be on the market by the end of 2005 (see 'Enzyme washing power cleans up rogue prions' ). British blood banks have already taken action to reduce prion content in blood products by, for example, removing white blood cells. They may also consider prion filtering, although this would be very expensive, and they could exclude donors of certain ages, although this would dramatically reduce blood supplies. "We are in a position of trading risks," says Turner. ©2005 Nature Publishing Group

Keyword: Prions
Link ID: 6978 - Posted: 06.24.2010

MADISON - Brain tests at the University of Wisconsin-Madison suggest that autistic children shy from eye contact because they perceive even the most familiar face as an uncomfortable threat. The work deepens understanding of an autistic brain's function and may one day inform new treatment approaches and augment how teachers interact with their autistic students. Tracking the correlation between eye movements and brain activity, the researchers found that in autistic subjects, the amygdala - an emotion center in the brain associated with negative feelings - lights up to an abnormal extent during a direct gaze upon a non-threatening face. Writing in the March 6 issue of the journal Nature Neuroscience, the scientists also report that because autistic children avert eye contact, the brain's fusiform region, which is critical for face perception, is less active than it would be during a normally developing child's stare. "This is the very first published study that assesses how individuals with autism look at faces while simultaneously monitoring which of their brain areas are active," says lead author Kim Dalton, an assistant scientist at UW-Madison's Waisman Laboratory for Brain Imaging and Behavior. Dalton measured eye movements in conjunction with magnetic resonance imaging (MRI), a sophisticated technology that allows researchers to "see" a brain in action.

Keyword: Autism; Emotions
Link ID: 6977 - Posted: 03.07.2005

Scientists say they are closer to finding new ways to treat a devastating brain disease passed from parents to children. People with Fragile X syndrome lack a healthy gene on the X 'sex' chromosome that means they have mental impairment. Few medications exist that help, but the University of Pennsylvania team have been able to test new drugs on specially modified fruit flies. The flies were bred to have the same mutant gene as humans with Fragile X. The disorder is passed on within families in what is known as X-linked recessive pattern of inheritance. Women tend to be carriers of the genetic defect because their other X chromosome may be healthy and compensate. But they can pass the damaged X on to some of their children. Any son who inherits the damaged X will be affected, while daughters may only be carriers. The main problem in Fragile X is mental impairment. This may range from a normal IQ to severe learning disabilities. Other symptoms include hyperactivity, attention deficit disorder, emotional and behavioural problems, anxiety, mood swings and seizures. Many children with Fragile X are mistakenly labelled as simply badly behaved or as having autism. There is no cure, but behavioural therapies can help. Families can also seek genetic screening. Dr Thomas Jongens and colleagues had already found mouse and fruit fly models of Fragile X showed similar symptoms to humans with Fragile X. They also had a tendency to poor communication between nerve cells due to increased activity of a receptor found on nerve cells called mGluR. (C)BBC

Keyword: Development of the Brain
Link ID: 6976 - Posted: 03.05.2005

The length of a man's fingers can reveal how physically aggressive he is, Canadian scientists have said. The shorter the index finger is compared to the ring finger, the more boisterous he will be, University of Alberta researchers said. But the same was not true for verbal aggression or hostile behaviours, they told the journal Biological Psychology after studying 300 people's fingers. The trend is thought to be linked to testosterone exposure in the womb. It has been known for some time that there is a direct correlation between finger lengths and the amount of the male sex hormone testosterone that a baby is exposed to in the womb. In women, the two fingers are usually almost equal in length, as measured from the crease nearest the palm to the fingertip. In men, the ring finger tends to be much longer than the index. Other studies looking at finger length ratio have suggested that, in men, a long ring finger and symmetrical hands are an indication of fertility, and that women are more likely to be fertile if they have a longer index finger. One study found boys with shorter ring fingers tended to be at greatest risk of a heart attack in early adulthood, which was linked to testosterone levels. In the current study, Dr Peter Hurd and his student Allison Bailey measured the fingers of 300 undergraduates at their university. Men with the shortest index fingers scored higher on measures of physical aggression than those with longer index fingers, but the study's findings did not apply to women. Dr Hurd is now looking at male hockey players to see whether there is any correlation between finger lengths and each player's penalty record for contact and fouling during matches. (C)BBC

Keyword: Aggression; Hormones & Behavior
Link ID: 6975 - Posted: 03.05.2005

Americans celebrate their freedom every year on the same day that Matthew Nagle lost almost all of his. As Fourth of July fireworks flashed over Wessagussett Beach in Weymouth, Massachusetts nearly four years ago, Nagle found himself in a sea of flying fists and within minutes, Nicholas Cirignano, a man with a lengthy criminal past, plunged a hunting knife into Nagle's neck, severing his spine. Doctors had two more pieces of bad news for Nagle: He'd never walk again and his daily activity would be severely limited. But Brown University neuroscientist John Donoghue has another life in mind for people like Nagle, whose paralysis renders him highly dependent on others. Since the 1990’s, Donoghue's been working on a brain implant that can route brain signals to machines that process the signals and issue commands. Now, just by thinking about the action of opening and closing his own paralyzed hand, Nagle is able to do the same to an artificial hand. Donoghue, founder of Cyberkinetics, Inc., a company that interfaces machines and the brain, is tapping into what's still intact in most paralyzed people, their brain. "There's a perfectly good brain capable of producing commands about the intention to move but those commands can't get to the spinal cord or to the muscles because the wires, or the axons, have been cut," he explains. © ScienCentral, 2000- 2005.

Keyword: Robotics
Link ID: 6974 - Posted: 06.24.2010

Heavy ecstasy use is linked to an increase in depressive symptoms in some people, a study suggests. A Cambridge University team studied 124 people and found those with a certain genetic make-up showed greater signs of depression after using the drug. The scientists, writing in the American Journal of Psychiatry, said it could show how vulnerable ecstasy users are to long-term psychiatric problems. Up to two million ecstasy tablets are taken in England each week. The researchers said heavy users, such as the people they studied, would probably be using ecstasy every week. Previous studies have suggested ecstasy users may experience an unpleasant lowering of mood for up to three days after taking the drug. There have also been suggestions that ecstasy can cause episodes of severe depression. Ecstasy is known to affect serotonin, a key brain chemical in the regulation of mood and emotion The Cambridge team looked at 66 ecstasy users, 30 cannabis users and 28 healthy volunteers who had not used any drug. They looked at the gene which controls serotonin transporters in the brain. Everybody has two copies of each gene, and there are two possible versions which people can carry, so they can either be classed as ll, ls or ss. They also used a recognised depression measurement scale to assess people, and carried out emotion recognition computer tests, - where people are asked to respond rapidly to happy or sad words. Some 60% of people who had the ss version were assessed as having at least mild depression. They also scored more poorly on the emotional processing tests. Non-drug users with the ss type displayed no such problems. (C)BBC

Keyword: Drug Abuse; Depression
Link ID: 6973 - Posted: 03.04.2005

By ANDREW POLLACK The makers of the multiple sclerosis drug Tysabri said yesterday that a second patient who used the drug had been confirmed to be suffering from a rare but deadly brain infection. The confirmed diagnosis is likely to somewhat diminish the chances that the drug will be able to return to the market. The makers of the drug, Biogen Idec and Elan, halted sales and clinical trials on Monday, saying that one patient in a clinical trial had died from the brain infection and a second patient from the same trial, who was still alive, was also suspected of having it. The companies also said yesterday that they had "undertaken to provide information" to the Securities and Exchange Commission about the suspension of sales, which led to major declines in the stocks of both companies. Anita Kawatra, a spokeswoman for Elan, said, "Our understanding is it's a routine inquiry related to the stock price move." A few executives or directors of Biogen sold shares in the days just before the company said it learned of the possible problem with Tysabri. One executive sold on the same day that the company told regulators about the problem. A company spokesman said the executives did not know of the situation with Tysabri when they sold. Copyright 2005 The New York Times Company

Keyword: Multiple Sclerosis
Link ID: 6972 - Posted: 03.04.2005

A gene which is likely to be one of the causes of dyslexia in children has been discovered by researchers at Cardiff University. They believe the major finding will give researchers a better understanding of what causes the brain disorder which disrupts reading and writing skills. It is now hoped that follow-up research will also lead to the discovery of treatments which could help children susceptible to dyslexia. The discovery was made by a team from the Department of Psychological Medicine, Wales College of Medicine. They carried out analysis of 300 families from Wales and the West of England where at least one child suffered from the disorder. The research team led by Professor Julie Williams and Professor Michael O'Donovan will now continue their study in order to discover more about the gene called "KIAA0319". The research will focus on discovering exactly how the gene works within the brain to disrupt reading and writing skills. Professor Williams said: "This is a major breakthrough and the first study to identify one gene which contributes to susceptibility to the common form of dyslexia. We would like to thank all the parents and children who took part in the study and would extend a call to new volunteers to take part in this important research."

Keyword: Dyslexia; Genes & Behavior
Link ID: 6971 - Posted: 03.04.2005

Jonathan Leake, Science Editor ONCE they were a byword for mindless docility. But cows have a secret mental life in which they bear grudges, nurture friendships and become excited over intellectual challenges, scientists have found. Cows are also capable of feeling strong emotions such as pain, fear and even anxiety — they worry about the future. But if farmers provide the right conditions, they can also feel great happiness. The findings have emerged from studies of farm animals that have found similar traits in pigs, goats, chickens and other livestock. They suggest that such animals may be so emotionally similar to humans that welfare laws need to be rethought. Christine Nicol, professor of animal welfare at Bristol University, said even chickens may have to be treated as individuals with needs and problems. “Remarkable cognitive abilities and cultural innovations have been revealed,” she said. “Our challenge is to teach others that every animal we intend to eat or use is a complex individual, and to adjust our farming culture accordingly.” Nicol will be presenting her findings to a scientific conference to be held in London next month by Compassion in World Farming, the animal welfare lobby group. Copyright 2005 Times Newspapers Ltd.

Keyword: Emotions; Animal Rights
Link ID: 6970 - Posted: 06.24.2010

Electrodes placed deep in the brains of severely depressed patients alleviate their misery when no other treatments can, according to new research. Deep brain stimulation is a relatively new approach to treating brain disease. Unlike electroconvulsive or "shock" therapy, which involves placing electrodes on the scalp, deep brain stimulation delivers small jolts of electricity directly to specific parts of the brain. The technique has been used with some success to alleviate the symptoms of Parkinson’s disease, but no one had tried it for depression. Researchers led by Helen Mayberg of the Emory University School of Medicine in Atlanta, Georgia, targeted the subgenual cingulate, a part of the emotional brain that has been shown to be hyperactive in depression. The team implanted electrodes in the brains of six patients, all of whom had failed to benefit from a variety of therapies, including shock treatments. The electrodes were attached to generators implanted under their collarbones that continuously delivered high-frequency, low-voltage pulses of electricity. All patients experienced immediate effects from the stimulation--reporting such impressions as a "disappearance of the void" and feelings of "connectedness." After 6 months with the implants, four of the six said their depression had mostly lifted. In one woman, the experimenters tried turning off the stimulator and found that depressive symptoms gradually returned after a few weeks. But she cheered up soon after the current was turned on again, the scientists report today in Neuron. Mayberg believes that the longer the treatment period, the more durable the effects will be. --CONSTANCE HOLDEN Copyright © 2005 by the American Association for the Advancement of Science.

Keyword: Depression
Link ID: 6969 - Posted: 06.24.2010

Certain genetic diseases affect children's educational abilities in a distinctive pattern: impairing their numerical abilities more than their verbal skills. New research sheds light on this split in abilities by investigating how differences in brain structures may influence how the mind works. Researchers at The Children's Hospital of Philadelphia, studying a common chromosome disorder, have used high-tech imaging tools to identify abnormal brain tissue associated with problems in perceiving spatial relationships and thinking about numbers. Understanding the links between brain structure and brain function may offer clues to improving methods to help children with specific learning disabilities. By pinpointing specific sites in the brain associated with impaired mental functions, scientists hope to eventually help children retrain their brains to follow alternative pathways and work around their cognitive weaknesses. Cognitive neuroscientist Tony J. Simon, Ph.D., led the studies of children with chromosome 22q11.2 deletion syndrome, the most common genetic deletion syndrome. In this disorder, a tiny portion of chromosome 22 is missing, causing symptoms such as heart defects, cleft palate, abnormal immune responses and cognitive impairments. Children's Hospital is a world center for research and treatment of the syndrome.

Keyword: Intelligence; Development of the Brain
Link ID: 6968 - Posted: 03.04.2005

Rex Dalton A computer-generated model of the skull of Homo floresiensis, our diminutive human relative, confirms that the controversial specimens from Indonesia do indeed represent a new species. The study of the creature's brainpan shows that it was neither a pygmy nor an individual with a malformed skull and brain, as some critics contend. This lends support to the discovery team's assertion that the metre-tall specimen belongs to a species distinct from Homo erectus. A skull and bones from eight H. floresiensis individuals were unearthed in a cave on Indonesia's island of Flores over 2003 and 2004 by a team of Indonesian and Australian researchers. The new species, which may have been alive as recently as 18,000 years ago, was reported in Nature1,2 last October. It generated huge fanfare among scientists and anthropology buffs. But a handful of critics have questioned the scientific description, contending that the specimens represent a tribe of pygmies, with at least one member having a deformed skull and brain, a condition called microcephaly. ©2005 Nature Publishing Group

Keyword: Evolution
Link ID: 6967 - Posted: 06.24.2010

By Patrik Jonsson | Correspondent of The Christian Science Monitor RALEIGH, N.C. – Hardly articulate, the tiny strangleweed, a pale parasitic plant, can sense the presence of friends, foes, and food, and make adroit decisions on how to approach them. Mustard weed, a common plant with a six-week life cycle, can't find its way in the world if its root-tip statolith - a starchy "brain" that communicates with the rest of the plant - is cut off. The ground-hugging mayapple plans its growth two years into the future, based on computations of weather patterns. And many who visit the redwoods of the Northwest come away awed by the trees' survival for millenniums - a journey that, for some trees, precedes the Parthenon. As trowel-wielding scientists dig up a trove of new findings, even those skeptical of the evolving paradigm of "plant intelligence" acknowledge that, down to the simplest magnolia or fern, flora have the smarts of the forest. Some scientists say they carefully consider their environment, speculate on the future, conquer territory and enemies, and are often capable of forethought - revelations that could affect everyone from gardeners to philosophers. Indeed, extraordinary new findings on how plants investigate and respond to their environments are part of a sprouting debate over the nature of intelligence itself. Copyright © 2005 The Christian Science Monitor.

Keyword: Intelligence; Evolution
Link ID: 6966 - Posted: 06.24.2010

The first experimental evidence that birds can be deceived by camouflage in the same way that humans are deceived, is published today in Nature The first experimental evidence that birds can be deceived by camouflage in the same way that humans are deceived, is published today in Nature [3 March 2005]. The idea that bold contrasting colours help to break-up the body's outline was rapidly adopted by many armies as long ago as the First World War. And in biology this idea of 'disruptive colouration' has long been used to explain how insects such as moths conceal themselves from predators, shaping the evolution of protective coloration in insects. Innovative research from the University of Bristol provides the strongest evidence to date that disruptive patterns do indeed protect insects from detection by birds, the predator most likely to have shaped the evolution of protective coloration in insects. Professor Innes Cuthill and his team pinned artificial 'moths' to trees in a field with a dead mealworm attached. The 'moths' were triangular pieces of waterproof card with specific patterns printed on them. By varying the colours, size and location of patterns on the moths the team were able to mimic real tree characteristics and identify which pattern combinations were the most successful.

Keyword: Vision
Link ID: 6965 - Posted: 03.03.2005

MINNEAPOLIS / ST. PAUL--Mistakes made by human subjects in identifying the facing direction of faces, cars or meaningless objects have yielded evidence that the brain contains nerve cells, or neurons, whose job is to encode the viewing angle of objects. It is well known that certain neurons respond to color, motion, edges and other aspects of our environment. Now, University of Minnesota researchers have found that our visual cortex contains neurons that tell us, for example, whether a face is turned in our direction or not. The work adds to knowledge of how the brain collects and processes visual information leading to the recognition of objects, and it may inform the design of machine vision. The study will be published in the March 3 issue of the journal Neuron. The brain relies on millions of neurons to report the visual elements of our environment. But, for example, if every neuron geared to motion fired in response to any motion whatsoever, then we couldn't tell whether a train was chugging into the distance or bearing down on us. Instead, to gain a complete picture of the world, our brains appear to contain separate, but physically intertwined, populations of neurons that respond to only one small aspect of our environment. The brain then bases its interpretation of images largely on which neurons fire. "The issue is, what is the underlying neural mechanism that supports the ability to recognize objects viewed from different angles?" said Sheng He, associate professor of psychology, who directed the study. "This study supports the idea that we have explicit representations in our brains for specific views of objects." The study was carried out jointly with Fang Fang, a graduate student in He's laboratory.

Keyword: Vision
Link ID: 6964 - Posted: 03.03.2005