UCIMon, 16 Apr 2007 14:55 UTC
A study by U.S. and Australian researchers is helping dispel the 40-year-old "thrifty genotype theory," which purports that certain minority groups are genetically prone to diabetes.
The study, co-authored by UC Irvine anthropologist Michael Montoya, along with an epidemiologist and population geneticist, analyzed existing genetic studies published across a variety of disciplines. The team found no evidence to support the widely held thrifty genotype theory, which suggests that cycles of feast and famine early in human history created a gene that helps the body use scarce nutrients - a gene that leads to obesity and diabetes in comfortable, sedentary modern lifestyles.
In the first nationally representative study to examine the relationship between survey measures of household firearm ownership and state level rates of suicide in the U.S., researchers at the Harvard School of Public Health (HSPH) found that suicide rates among children, women and men of all ages are higher in states where more households have guns. The study appears in the April 2007 issue of The Journal of Trauma.
"We found that where there are more guns, there are more suicides," said Matthew Miller, Assistant Professor of Health Policy and Management at HSPH and lead author of the study.
Suicide ranks as one of the 15 leading causes of death in the U.S.; among persons less than 45 years old, it is one of the top three causes of death. In 2004, more than half of the 32,439 Americans who committed suicide used a firearm.
Alison Abbott
NatureMon, 16 Apr 2007 07:41 UTC
Passively listening to Mozart - or indeed any other music you enjoy - does not make you smarter. But more studies should be done to find out whether music lessons could raise your child's IQ in the long term, concludes a report analysing all the scientific literature on music and intelligence, which was published last week by the German research ministry.
The ministry commissioned the report - surprisingly the first to systematically review the literature on the purported intelligence effect of music - from a team of nine German neuroscientists, psychologists, educationalists and philosophers, all music experts. The ministry felt it had to tackle the subject because it had been inundated with requests for funding of studies on music and intelligence, which it didn't know how to assess.
In a study that could help reveal how illusions are produced in the brain's visual cortex, researchers at the UCSD School of Medicine have found new evidence of rapid integration of auditory and visual sensations in the brain. Their findings, which provide new insight into neural mechanisms by which visual perception can be altered by concurrent auditory events, will be published online in the April 12 edition of the Journal of Neuroscience.
When subjects were shown a single flash of light interposed between two brief sounds, many subjects reported seeing two distinct flashes of light. Investigating the timing and location of the brain processes that underlie this illusory effect -- the illusion of seeing two flashes in the presence of two auditory signals, when only one flash actually occurs -- can reveal how information from different senses are integrated in the brain.
The study of 34 subjects was carried out in the laboratory of Steven A. Hillyard, Ph.D., UCSD professor of neurosciences. "This type of perceptual illusion has been described before," said first author Jyoti Mishra, graduate student in the Hillyard lab. "The surprising finding we made is that the illusion depends on a rapidly timed sequence of interactions between the auditory and visual cortical areas."
Men's and women's brains "fire" differently when they are planning how to reach for something, so rehabilitation after brain injuries such as strokes may need to be tailored to the sex of the person, says a new study by York University researchers.
Associate professor Lauren Sergio and recent PhD graduate Diana Gorbet, of the Faculty of Health's School of Kinesiology, found differences in patterns of brain activity in men and women preparing to do visually-guided actions related to tasks such as using a computer mouse or driving a car. Their findings were published online recently by the European Journal of Neuroscience.
"We found that in females there were three major brain areas involved in visually-guided movement and they showed activity on both sides of the brain in most of the exercises in the study," says Sergio. "In contrast, male brains lit up on both sides only for the most complex exercise."
One cause of high blood pressure may lie within the brain, and not the heart or blood vessels
The controversial idea that one cause of high blood pressure lies within the brain, and not the heart or blood vessels, has been put forward by scientists at the University of Bristol, UK, and is published this week in the journal Hypertension.
Dr. Hidefumi Waki, working in a research group led by Professor Julian Paton, has found a novel role for the protein, JAM-1 (junctional adhesion molecule-1), which is located in the walls of blood vessels in the brain.
JAM-1 traps white blood cells called leukocytes which, once trapped, can cause inflammation and may obstruct blood flow, resulting in poor oxygen supply to the brain. This has led to the idea that high blood pressure - hypertension - is an inflammatory vascular disease of the brain.
One in three people in the UK are likely to develop hypertension, and with 600 million people affected world wide, it is of pandemic proportions. The alarming statistic that nearly 60 per cent of patients remain hypertensive, even though they are taking drugs to alleviate the condition, emphasises the urgency of looking for new mechanisms by which the body controls blood pressure, and finding new therapeutic targets to drive fresh drug development.
Those persons who are labeled a "night owl" report more pathological symptoms related to insomnia, despite many having the opportunity to compensate for their nocturnal sleeplessness by extending their time in bed and being able to gain more total sleep time, according to a study published in the April 15th issue of the Journal of Clinical Sleep Medicine (JCSM).
The study, authored by Jason C. Ong, PhD, and colleagues at Stanford University, consisted of 312 patients, who were categorized as morning, intermediate and evening chronotypes based upon scores on the Morningness-Eveningness Composite Scale. Group comparisons were made on self-report measures of nocturnal sleep, sleep period variability and waking correlates and consequences of insomnia.
Compared to the morning and intermediate types, people with insomnia who prefer evening activities (i.e., "night owls") reported the most sleep/wake irregularities and waking distress, even after adjusting for severity of sleep disturbance.
"Our findings indicate that further research should investigate the relationship between circadian rhythms and insomnia, especially with the severity of the 'night owl' group," said Ong. "These factors may serve to perpetuate the insomnia disorder, and might be particularly important to consider when treating this subgroup of insomniacs."
WASHINGTON - Abstinence-only education programs meant to teach children to avoid sex until marriage failed to control their sexual behavior, according to a government report.
Experience seeing a person's face makes it easier to hear them
Experience hearing a person's voice allows us to more easily hear what they are saying. Now research by UC Riverside psychology Professor Lawrence D. Rosenblum and graduate students Rachel M. Miller and Kauyumari Sanchez has shown that experience seeing a person's face also makes it easier to hear them.
Rosenblum's paper, "Lip-Read Me Now, Hear Me Better Later: Crossmodal Transfer of Talker Familiarity Effects," will appear in the May issue of the journal Psychological Science, published by the Association for Psychological Science.
Sixty college undergraduates were asked to lip-read sentences from a silent videotape of a talker's face. These subjects all had normal hearing and vision and had no formal lip reading experience.
A new study in Psychophysiology confirms a surprising fact - men who have undergone chemical castration for conditions such as prostate cancer experience hot flashes similar to those experienced by menopausal women. Using a technique called sternal skin conductance, doctors were able to positively identify hot flashes in males, a positive step toward providing therapy for those patients in need.
"Most people are unaware that men can have hot flashes," says study author Dr. Laura Hanisch. "Even the patients themselves are often unaware that they are having them." Having a test that objectively measures when hot flashes are occurring can help both doctors and patients identify the episodes, and can assist researchers in finding their root cause.
