Michael Reilly, Discovery News -- Shrews use a primitive form of sonar to navigate their cluttered habitats of underbrush, according to a new study. Though scientists have known for decades that shrews emit audible twittering calls, they have been puzzled as to whether they are used for communication, or for contending with the dense hay and grass, or dark tunnels that fill their environment. Bjorn Siemers of the Max Planck Institute of Ornithology in Germany and a team of researchers captured seven common shrews (Sorex araneus) and nine greater white-toothed shews (Crocidura russula). They tested the animals' behavior in hay layers of varying thickness, and used scent indicators to see whether the shrews changed their calls when they detected the presence of another animal. The shrews didn't respond to scents placed in their cages, and their calls became more rapid as the amount of hay in their environment increased, both of which point to the calls functioning as a navigational aid. Bats and dolphins also use sound to echolocate, but they are more refined in their abilities “ they emit fast, ultrasonic clicks that help them hone in on prey. Shrews' utterances are much slower by comparison and are confined to the audible range, at frequencies of 5-8 kHz. Previous studies also show that shrews can distinguish closed tunnels from open ones in utter darkness. © 2009 Discovery Communications, LLC

Keyword: Hearing
Link ID: 12968 - Posted: 06.24.2010

by Nora Schultz, Berlin SLEEPING on a complex decision may not help you make the best choice after all. So say two studies that question the evidence for unconscious decision-making. The "unconscious thought" theory for making complex decisions was proposed in a 2006 study by Ap Dijksterhuis at the University of Amsterdam in the Netherlands, and colleagues. The team showed volunteers a series of cars and their attributes on a screen, before asking half of them to think carefully about choosing the best car, and the other half to solve anagrams - a distraction technique to allow unconscious processing. Those in the anagram group were more likely to choose the cars with the best attributes, leading the researchers to conclude that it is best to leave tough choices to the unconscious (Science, vol 311, p 1005). Now two teams have questioned this conclusion. Instead, they suggest that the volunteers made their decisions when they first viewed the data, based on an immediate gut instinct. Those in the anagram group simply recalled this original decision when asked to choose. Those in the "thinking" group, however, reconsidered their first impressions while the details of the cars faded from their memory, which led to poorer choices. "What Dijksterhuis ignored is that people might already decide when they first hear about the cars, and not after thinking about it or solving anagrams," says psychologist Daniel Lassiter of Ohio University in Athens. To test this hypothesis, Lassiter and his colleagues repeated Dijksterhuis's experiment with a twist: they told the volunteers to memorise the cars' attributes while viewing them, thus distracting their attention from making an immediate decision. © Copyright Reed Business Information Ltd.

Keyword: Sleep; Learning & Memory
Link ID: 12967 - Posted: 06.24.2010

By Susan Milius MOSCOW, Idaho — Sometimes it’s good to be not so hot. Capsaicinoid compounds, which give chilies their culinary kick, have the happy effect of discouraging a seed-rotting fungus that grows on plants. But new work has found that protecting seeds has a downside, says David C. Haak of the University of Washington in Seattle. In wild chilies, tests linked pungency with vulnerability to drought and to attacks by ants that devour the seeds, he reported June 14 at the Evolution 09 meeting. Chili heat may turn out to be an example of populations adapting to particular local circumstances, an important concept in evolutionary theory, Haak says. And the link between capsaicinoid levels and vulnerability could explain why, even within the same species, not all chilies are hot. Haak says the seed-attacker Fusarium fungus lurks throughout the chilies’ wild range. It’s nasty stuff that ruins about a third of seeds, even in the driest places. Yet he and his colleagues have found plants in dry spots skimp on the protective capsaicinoids. In a dry-zone population, plants yielding mouth-scorching chilies were more rare than in a population in a somewhat wetter place. And the hottest of the dry-zone plants didn’t reach the flamer extremes of the exceptional chilies in more moist zones. Those hot and not chilies illustrate how “adaptations that are beneficial in one environment may be costly in another — for example, pungency in a dry climate,” says Emily Jacobs-Palmer of Harvard University. © Society for Science & the Public 2000 - 2009

Keyword: Pain & Touch; Evolution
Link ID: 12966 - Posted: 06.24.2010

By Bruce Bower Mosquito fish don’t just count on each other for protection from predators — they literally count each other for such protection. These guppylike fish can use numerical information to identify the larger of two nearby groups of fellow fish, report psychologist Marco Dadda of the University of Padova in Italy and his colleagues in an upcoming Cognition. That’s a useful skill to have, the researchers say. Larger groups, or shoals, offer a more effective shield against bigger fish with empty bellies. The researchers allowed individual mosquitofish in a tank to see groups of other fish, but barricades prevented them from seeing an entire group at once. When viewing fish one at a time in each of two groups, mosquito fish spent much more time near larger groups, Dadda and his colleagues report. The fish preferred groups of three over two fish and groups with eight fish over four fish. “We have provided the first evidence that fish are capable of selecting the larger group of social companions by relying exclusively on numerical information,” Dadda says. In two earlier studies, Dadda’s group demonstrated that mosquito fish can distinguish between large quantities, such as 16 versus 8, provided that the numerical ratio is at least 2:1. Such distinctions draw on an ability to estimate large amounts without counting, such as noting the greater area or density of the larger of two shoals, the researchers say. © Society for Science & the Public 2000 - 2009

Keyword: Intelligence; Evolution
Link ID: 12965 - Posted: 06.24.2010

Jeremy Laurance Scientists are debating whether stimulants are an acceptable means for people to boost their brain's performance In the middle of the exam season, the offer of a drug that could improve results might excite students but would be likely to terrify their parents. Now, a distinguished professor of bioethics says it is time to embrace the possibilities of "brain boosters" – chemical cognitive enhancement. The provocative suggestion comes from John Harris, director of the Institute for Science, Ethics and Innovation at the University of Manchester, and editor-in-chief of the Journal of Medical Ethics. Ritalin is a stimulant drug, best known as a treatment for hyperactive children. But it has also found a ready black market among students, especially in the US, who are desperate to succeed and are turning to it in preference to the traditional stimulants of coffee and cigarettes. Users say it helps them to focus and concentrate, and this has been confirmed in research studies on adults. David Green, a student at the University of Harvard, told The Washington Post: "In all honesty, I haven't written a paper without Ritalin since my junior year in high school." Matt, a business finance student at the University of Florida, claimed a similar drug, Adderall, had helped him improve his grades. "It's a miracle drug," he told The Boston Globe. "It is unbelievable how my concentration boosts when I use it." ©independent.co.uk

Keyword: Learning & Memory; Drug Abuse
Link ID: 12964 - Posted: 06.24.2010

By Katherine Harmon Homosexual behavior seems pointedly un-Darwinian. An animal that doesn't pass along genes by mating with the opposite sex at every, well, conceivable opportunity, seems to be at an evolutionary disadvantage. So what’s in it for the 450-plus species that go for same-sex sex? Two evolutionary biologists from University of California, Riverside, set out to answer that question in a paper published today in Trends in Ecology and Evolution. "It's been observed a lot," says Nathan Bailey, a post-doctoral researcher at U.C. Riverside and lead study author, of same-sex sexual behavior in animals. "But it took people a long time to put it in an evolutionary context." After studying dozens of published articles on the topic, Bailey and his colleague Marlene Zuk concluded that, in addition to being an adaptational strategy, "these behaviors can be a force," Bailey said. "They create a context in which selection can occur [differently] within a population." In the Laysan albatross, for example, previous research has shown that a third of all bonded pairs in a Hawaii colony are two females. This behavior helps the birds, whose colony has far more females than males, by allowing them to share parenting responsibilities. It also gives more stability to the offspring of males, already bonded to a female, who mate opportunistically with females in a same-sex couple. Such a dynamic, then may force gradual changes in behavior and even physical appearance of the birds, the authors note. © 1996-2009 Scientific American Inc.

Keyword: Sexual Behavior; Evolution
Link ID: 12963 - Posted: 06.24.2010

by Arran Frood IN THE early 1960s, a young Russian neurophysiologist called Yuri Moskalenko travelled from the Soviet Union to the UK on a Royal Society exchange programme. During his stay, he co-authored a paper published in Nature. "Variation in blood volume and oxygen availability in the human brain" may not sound subversive, but it was the start of a radical idea. Decades later, having worked in Soviet Russia and become president of the Sechenov Institute of Evolutionary Physiology and Biochemistry at the Russian Academy of Sciences in St Petersburg, Moskalenko is back in the UK. Now collaborating with researchers at the Beckley Foundation in Oxford, his work is bearing fruit. And strange fruit it is. With funding from the foundation, he is exploring the idea that people with Alzheimer's disease could be treated by drilling a hole in their skull. In fact, he is so convinced of the benefits of trepanation that he claims it may help anyone from their mid-40s onwards to slow or even reverse the process of age-related cognitive decline. Can he be serious? For thousands of years, trepanation has been performed for quasi-medical reasons such as releasing evil spirits that were believed to cause schizophrenia or migraine. Today it is used to prevent brain injury by relieving intracranial pressure, particularly after accidents involving head trauma. In the popular imagination, though, it is considered crude, if not downright barbaric. Yet such is the desperation for effective treatments for dementia that drilling a hole in the skull is not even the strangest game in town (see "Desperate measures to treat dementia"). © Copyright Reed Business Information Ltd

Keyword: Alzheimers
Link ID: 12962 - Posted: 06.24.2010

by Catherine Brahic Monkeys may see, hear and speak no evil, but they sure can be naughty, according to the first study to compare the ability of monkeys to deceive others in order to get food. Intentional deceit is not restricted to humans, say Federica Amici and colleagues of Liverpool John Moores University in the UK. Some monkeys use simple forms of deceit, and the ability depends not on how closely related they are to humans, but on their social structure. Amici's team put up to 10 monkeys from three different primate species through the same experiment designed to test their ability to deceive dominant monkeys. Spider monkeys, brown capuchins and long-tailed macaques were shown how to access food that was hidden or just out of reach. They were then put in cages with a socially higher-ranking monkey from the same species. Dominant monkeys in all three species would normally have priority over food, but in this case they did not know how to get to it. Subordinate monkeys of all three species went straight for the food when their dominant partner was not around. But as soon as the dominant monkey was introduced, they held back. This suggests they were intentionally withholding information in order to get the food for themselves. © Copyright Reed Business Information Ltd

Keyword: Animal Communication; Intelligence
Link ID: 12961 - Posted: 06.24.2010

Laurie Martin Transcranial magnetic stimulation (TMS) produced improvements in key areas of cognition and in short-term verbal memory in patients with major depressive disorder, and no adverse cognitive effects were shown.1 The results of this research were presented by Mark Demitrack, MD, vice president and chief medical officer of Neuronetics, Inc, and colleagues at the annual meeting of the American Psychiatric Association in May. In this study, cognitive function was examined in patients with pharmacoresistant major depressive disorder. Of these patients, 155 received TMS therapy and 146 received sham TMS. Results of the Mini Mental Status Examination, Buschke Selective Reminding Test, and Autobiographical Memory Interview-Short Form were obtained before the first treatment and at 4 and 6 weeks during an acute treatment course of daily TMS. No significant difference was found between the active TMS group and the placebo TMS group in any of these measures of cognitive function. At the end of the 6 weeks, each group was stratified by clinical outcome. Within the TMS responders group, there was significant improvement in scores on the Buschke Selective Reminding Test for short-term recall and delayed recall. This improvement in cognitive function was not seen in placebo-treated patients. © 1996 - 2009 CMPMedica LLC,

Keyword: Depression; Learning & Memory
Link ID: 12960 - Posted: 06.24.2010

MEN are doomed to uncertainty. Women know who their children are, but the ubiquity of sexual cheating makes it difficult for males of many species, humans included, to be sure which youngsters actually belong to them. If a male’s reproductive strategy amounts to little more than “Wham, bam, thank-you ma’am”, this may not matter to him much. But if, as in the human case, he takes an interest in his offspring, it matters a lot. There are few more foolish actions, from an evolutionary point of view, than raising another male’s progeny. This line of reasoning led Alexandra Alvergne and her colleagues at the University of Montpellier, in France, to wonder if human fathers recognise features of children that might give away whose offspring they really are, and use those to guide the amount of attention doled out to each putative son and daughter. To find out, they established an experiment among villagers in the Sine Saloum region of Senegal, where polygynous marriages (ie, men with multiple wives) are common. In such societies the incentives for unmarried men and the opportunities for neglected women to engage in what zoologists who study other harem-forming species refer to as “sneaking” are particularly high. It gives the men a chance to reproduce and the women a chance to spread their bets. Thirty families with at least two children aged between two and seven agreed to participate in a two-part study, in return for gifts of farming equipment and school supplies that were given to the head of their village for appropriate distribution. In the first part, photographs were taken of children and their “fathers”. Over 100 judges, selected from distant villages, were then given images of individual children along with images of three adult men. These judges were asked to decide which man was each child’s father. © The Economist Newspaper Limited 2009.

Keyword: Sexual Behavior; Evolution
Link ID: 12959 - Posted: 06.24.2010

By Patricia Moreau Imagine a quiet night like any other. Suddenly, your infant’s cries break the silence. Fully loaded with emotion, the sound triggers an urge to stand up and run to your infant’s room. But, considering that your spouse is a musician and you are not, who will be the first to reach the crib? According to Dana L. Strait and a team of researchers at the University of Northwestern in Chicago, the musician should win the race. Their latest study showed that years of musical training leave the brains of musicians better attuned to the emotional content, like anger, of vocal sounds. Ten years of cello, say, can make a person more emotionally intelligent, in some sense. So the alarm carried in a baby’s cry make a deeper impression; your spouse wins the race. The new work is part of an emerging portrait of the broader connections between music, emotion and speech. These studies are finding that musicians are more accurate in detecting emotion -- such as joy, sadness and anger -- in speech samples. The effect has been found even in children as young as 7 years old, with as little as one year of music training. It is a fascinating example of how experience in one domain (music) benefits another (emotion perception). However, it is not until very recently, with the publication of the new study by Strait and her colleagues, that the biological foundation of the effect has been demonstrated. Strait’s team decided to study the brain’s very first responses to sound, in the brain stem. The brain stem is the most ancient part of the brain, andis the main entry door for all sensory stimuli. © 1996-2009 Scientific American Inc.

Keyword: Hearing; Emotions
Link ID: 12958 - Posted: 06.24.2010

by Ewen Callaway Human intelligence may not be so human after all. New research on monkeys finds that individual animals perform consistently on numerous different tests of intelligence – a hallmark of human IQ and, perhaps, an indication that human intellect has a very ancient history. No doubt, the human brain has bulged in the six million or so years since our species last shared a common ancestor with chimpanzees, offering more cognitive prowess compared to our closest relatives. But traces of human intelligence, such as a sense of numbers, or the ability to use tools, lurk in a wide range of animals, particularly in other primates. Less clear, though, is whether animals possess the same kind of general intelligence as humans: where performance on one facet, say verbal, strongly predicts performance on other tests of intelligence like working memory. "We were essentially looking for evidence of a general intelligence factor – something that would be an evolutionary homologue of what we see in humans," says Konika Banerjee, a psychologist at Harvard University who led the new study along with colleague Marc Hauser. © Copyright Reed Business Information Ltd

Keyword: Intelligence; Evolution
Link ID: 12957 - Posted: 06.24.2010

By ABBY ELLIN LIKE almost every dieter in America, Wendy Bassett has used all sorts of weight-loss products. Nothing worked, she said, until she tried Sensa: granules she scatters on almost everything she eats, and which are supposed to make dieters less hungry by enhancing the smell and taste of food. “Every time I touch a piece of food, I pour it on,” said Ms. Bassett, 34, an accountant in Tyler, Tex. She has been using Sensa since February. So far, she said, she has lost 30 pounds. The maker of Sensa claims that its effectiveness is largely related to smell: the heightened scent and flavor of food that has been sprinkled with Sensa stimulate the olfactory bulb — the organ that transmits smell from the nose to the brain — to signal the “satiety center” of the hypothalamus. Hormones that suppress appetite are then released. But can the manipulation of smell really lead to weight loss? A handful of niche products would have you believe just that. In addition to Sensa, which has been available since last summer, there is SlimScents, aromatherapy diet pens filled with fruity or minty odors; a peppermint spray called Happy Scent; and the vanilla-doused Aroma Patch, which you wear on your hand, wrist or chest. Last month, Compellis Pharmaceuticals of Cambridge, Mass., began human trials on a nasal spray designed to do the opposite of what Sensa does: to curb the appetite by blocking rather than enhancing smell. Copyright 2009 The New York Times Company

Keyword: Obesity; Chemical Senses (Smell & Taste)
Link ID: 12956 - Posted: 06.24.2010

By Bruce Bower The last thing depression investigators need is another dead-end research downer. Efforts to find genes that directly contribute to depression have come up empty. And a research team now concludes, after a closer inspection of accumulated research, that a gene variant initially tagged as a depression promoter when accompanied by stressful experiences actually has no such effect. By showing that follow-up studies collectively don’t support the study that launched this line of research, two new analyses debunk the proposed pathway to depression. The chances of becoming depressed rise as stressful events mount, regardless of genetic makeup, report statistical geneticist Neil Risch of the University of California, San Francisco, and his colleagues. The new studies, published together in the June 17 Journal of the American Medical Association, also demonstrate the difficulty of replicating reports of any gene variants that appear to work with environmental triggers to foster psychiatric disorders. Individual studies typically lack the statistical power to detect gene-by-environment interactions correctly because most candidate genes and stressful events exert modest effects on mental ailments at best, the scientists say. “I’m supportive of looking for gene-by-environment risk factors, but we’ll need much larger samples to find interactions that can be independently replicated,” Risch says. In his view, statistically rigorous studies will need tens of thousands of participants. © Society for Science & the Public 2000 - 2009

Keyword: Depression; Genes & Behavior
Link ID: 12955 - Posted: 06.24.2010

Heidi Ledford A compound that stimulates the production of certain steroids in the brain may one day soothe the troubled nerves of people with anxiety disorders, according to results from a small clinical trial. The compound boosts the activity of a 'translocator' protein inside cells that helps transport cholesterol molecules and allows some to be turned into steroids that act in the brain. These 'neurosteroids' regulate the effect of a relaxation-promoting molecule called GABA, and are associated with reduced anxiety. Levels of the neurosteroids plummet during panic attacks. The compound has so far been tested only in a small clinical trial, but if it survives further testing, it could fill a need for better anxiety treatments. Patients with anxiety disorders have a range of symptoms, from recurrent and debilitating panic attacks to a more general sense of social anxiety. And some people use medication to quell acute phobias, such as a fear of flying or of public speaking. "It's not that we don't have treatments, but the available treatments suffer from undesirable adverse effects," says Jerrold Rosenbaum, chief of psychiatry at Massachusetts General Hospital in Boston. One class of drugs, called benzodiazepines, act quickly and are highly effective, but can cause drowsiness. Some users also develop a tolerance to them, and the withdrawal symptoms can be worse than the disorder itself, explains Rosenbaum. "A drug that worked nearly as well as the benzodiazepines without their unwanted side effects would be quite a big winner." © 2009 Nature Publishing Group

Keyword: Emotions; Hormones & Behavior
Link ID: 12954 - Posted: 06.24.2010

U.S. federal health regulators are urging parents to keep their children on attention deficit drugs like Ritalin and Adderall despite new evidence from a government-backed study that the stimulants can increase the risk of sudden death. Published Monday in the American Journal of Psychiatry, the study suggests a link between use of the stimulant drugs and sudden death in children and adolescents. The drugs, used to treat attention deficit and hyperactivity disorder, already carry warnings about risks of heart attack and stroke in children with underlying heart conditions, but researchers have questioned whether they pose the same risks to children without those problems. Healthy children taking the medications were more likely to die suddenly for unexplained reasons than those not taking the drugs, according to the study from the National Institute of Mental Health. The study was partially funded by the Food and Drug Administration, but agency experts said its methods — which relied on interviews with parents and physicians years after the children's deaths — may have caused errors. "Since the deaths occurred a long time ago, all of this depended on the memory of people, relatives and physicians, involved with the victims," said Dr. Robert Temple, the FDA's director of drug review. © The Canadian Press, 2009

Keyword: ADHD
Link ID: 12953 - Posted: 06.24.2010

By Judy Foreman For centuries, love has been celebrated - and probed - mostly by poets, artists, and balladeers. But now, its mysteries are also yielding to the tools of science, including modern brain scanning machines. Social psychologist Arthur Aron of SUNY-Stony Brook, a coauthor of the brain scanning studies and other research on love relationships, stresses the value of marriage workshops and couples counseling to enhance relationships. Also, to make a marriage really good, he says: Keep novelty and excitement going. Have a "date night" every week or so. Do novel things - take a course together, travel, join a new group of friends. (Get that dopamine system, which loves novelty, going again.) Capitalize on the good stuff. If something good happens to your partner, get sincerely excited about it so you can both enjoy the good fortune. It's not clear yet which brain circuits are at play here, says Aron, but associating your partner with good times is clearly a plus. At a university in Stony Brook, N.Y., a handful of young people who had just fallen madly in love volunteered to have their brains scanned to see what areas were active when they looked at a picture of their sweetheart. The brain areas that "lit up" were precisely those known to be rich in a powerful "feel good" chemical, dopamine -- the substance that brain cells release in response to cocaine and nicotine. Dopamine is the key chemical in the brain's "reward system," a network of cells associated with pleasure -- and addiction. © 2009 NY Times Co.

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 12952 - Posted: 06.24.2010

By RONI CARYN RABIN By now, it is a familiar litany. Study after study suggests that alcohol in moderation may promote heart health and even ward off diabetes and dementia. The evidence is so plentiful that some experts consider moderate drinking — about one drink a day for women, about two for men — a central component of a healthy lifestyle. For some scientists, the question will not go away. No study, these critics say, has ever proved a causal relationship between moderate drinking and lower risk of death — only that the two often go together. It may be that moderate drinking is just something healthy people tend to do, not something that makes people healthy. “The moderate drinkers tend to do everything right — they exercise, they don’t smoke, they eat right and they drink moderately,” said Kaye Middleton Fillmore, a retired sociologist from the University of California, San Francisco, who has criticized the research. “It’s very hard to disentangle all of that, and that’s a real problem.” Some researchers say they are haunted by the mistakes made in studies about hormone replacement therapy, which was widely prescribed for years on the basis of observational studies similar to the kind done on alcohol. Questions have also been raised about the financial relationships that have sprung up between the alcoholic beverage industry and many academic centers, which have accepted industry money to pay for research, train students and promote their findings. Copyright 2009 The New York Times Company

Keyword: Drug Abuse
Link ID: 12951 - Posted: 06.24.2010

By Valerie Strauss Sleeping used to be one of my favorite activities -- until I got lousy at it. I started having trouble with it last year when I found myself feeling more tired when I woke up than when I went to sleep. I practically fell asleep at my desk. (Okay, I did fall asleep on my keyboard.) My once respectable memory took a precipitous decline into the "I can't remember my own telephone number" range. And then there was the problem, for my husband and anyone within a three-room radius, of the snoring. So I asked some doctors to tell me why I was so exhausted. One said I was super-anxious and should get massages. (I didn't feel anxious.) Another said I was depressed. (I wasn't.) A third said that it could be hormonal. (What isn't?) Or not. Finally I decided to figure it out myself. After investigating possible causes for all my symptoms, I began to suspect I had apnea. Sleep apnea, it turns out, is a common disorder in which you momentarily stop breathing, or take very short breaths, while you are sleeping. The number of times your breathing is interrupted per hour determines the degree of your apnea. (A mild case is marked by five to 15 episodes; a severe case involves more than 30.) © 2009 The Washington Post Company

Keyword: Sleep
Link ID: 12950 - Posted: 06.24.2010

Alcohol-related deaths among U.S. college students rose from 1,440 deaths in 1998 to 1,825 in 2005, along with increases in heavy drinking and drunk driving, according to an article in the July supplement of the Journal of Studies on Alcohol and Drugs. The special issue describes the results of a broad array of research-based programs to reduce and prevent alcohol-related problems at campuses across the country. These studies resulted from the Rapid Response to College Drinking Problems Initiative, a grant program supported by the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health. Reviewing the magnitude of the college alcohol problem, Ralph W. Hingson, Sc.D, M.P.H., director of NIAAA’s Division of Epidemiology and Prevention Research, and colleagues analyzed data from the Centers for Disease Control and Prevention and other government sources. They found that serious problems persist, as indicated by the increase in drinking-related accidental deaths among 18- to 24-year-old students, which resulted mainly from traffic-related incidents. In addition, the researchers found the proportion of students who reported recent heavy episodic drinking — sometimes called binge drinking, defined as five or more alcoholic drinks on any occasion in the past 30 days— rose from roughly 42 percent to 45 percent, and the proportion who admitted to drinking and driving in the past year increased from 26.5 percent to 29 percent.

Keyword: Drug Abuse
Link ID: 12949 - Posted: 06.24.2010