Many people with early dementia can drive safely, a survey has suggested. The risk of crashes among Alzheimer's patients is "acceptably low" for up to three years after the disease becomes clinically apparent, they claim. The conclusions in the British Medical Journal are based on medical data published between 1966 and 2007. Anyone holding a UK driving licence must, by law, inform the DVLA if they have a medical condition that might affect the safety of their driving. The DVLA says that people with poor short-term memory are a higher risk and should not be driving. Lead researcher Professor Desmond O'Neill, of the Trinity Centre for Health Sciences and Meath Hospital in the Republic of Ireland, says there is a misconception about the impact of age-related disease on driving. He said many medical journals had reported an apparent increase in crashes per mile driven for older people, yet several studies have established that this is related to low mileage rather than to age. And surveys of drivers aged more than 80 consistently show prudent driving behaviours, said Professor O'Neill. He says the challenge for doctors and the licensing agency is to balance mobility and safety in a growing population of older drivers. Stopping driving can limit access to family, friends, and services and is an independent risk factor for entry into a nursing home, he said. (C)BBC

Keyword: Alzheimers
Link ID: 10440 - Posted: 06.29.2007

Children with cerebral palsy are just as happy as children without the condition are, a study has shown. Their physical impairment does not have a negative effect on their relationships, moods or welfare, researchers report in The Lancet. Experts said the study of 500 children aged 8-12 years with cerebral palsy underlined the importance of supporting disabled children to lead full lives. Cerebral palsy affects around one in 400 children in the UK. It results from the failure of a part of the brain to develop before birth or in early childhood, or brain damage which permanently affects body movement and muscle coordination. Most children with cerebral palsy are born with it, although it may not be detected until months or years later. Previous studies have attempted to look at the quality of life of children with cerebral palsy but they focused on physical effects of the condition or relied on the views of parents. A team of European researchers, led by the University of Newcastle, asked the children themselves about several aspects of their lives and compared their responses with those from children of the same age in the general population. The questionnaire covered areas such as physical and psychological wellbeing, moods and emotions, self-perception and relationships with parents, friends and school. On most of the areas, children with cerebral palsy had similar scores to the general population. The only exceptions were schooling for which the results were not clear and physical wellbeing which could not be compared. (C)BBC

Keyword: Development of the Brain
Link ID: 10439 - Posted: 06.29.2007

Italian scientists have developed a pill that expands in the stomach to make dieters feel full. They liken the effect to eating a bowl of spaghetti and say the pill can stop hunger for a few hours. It is made from a hydrogel, which the team developed when trying to make more absorbent nappy linings, and may help in the battle against obesity. So far it has been tested on 20 people but experts warned bigger trials would be needed to test safety. Professor Luigi Ambrosio, lead researcher on the study at Italy's National Research Council, realised when they developed the hydrogel it may have a similar effect to gastric banding - a surgical procedure that reduces the size of the stomach. The tiny pill is powdery when dry but when swallowed with a glass of water turns to a jelly-like ball in the stomach. It is made from an organic compound called cellulose so can break down in the body and pass through the digestive system. The pill, which has yet to be named, is being tested in a further 90 overweight volunteers who will be monitored to see how much weight they lose and if there are any adverse effects. Professor Ambrosio said the pill should be taken about 30 minutes to one hour before each meal. It passes through the digestive system within five to six hours. "One of our researchers tried the pill - he took it at about 11am and was still full at six in the evening. It's like eating a bowl of spaghetti." (C)BBC

Keyword: Obesity
Link ID: 10438 - Posted: 06.29.2007

Alex Quinn Species in the genotypic group, like mammals and birds, have sex chromosomes, which in reptiles come in two major types. Many species—such as several species of turtle and lizards, like the green iguana—have X and Y sex chromosomes (again, like mammals), with females being "homogametic," that is, having two identical X chromosomes. Males, on the other hand, are "heterogametic," with one X chromosome and one Y chromosome. Other reptiles governed by GSD have a system, similar to one found in birds, with Z and W sex chromosomes. In this case—which governs all snake species—males are the homogametic sex (ZZ) and females are the heterogametic sex (ZW). In temperature-dependent sex determination, however, it is the environmental temperature during a critical period of embryonic development that determines whether an egg develops as male or female. This thermosensitive period occurs after the egg has been laid, so sex determination in these reptiles is at the mercy of the ambient conditions affecting egg clutches in nests. For example, in many turtle species, eggs from cooler nests hatch as all males, and eggs from warmer nests hatch as all females. In crocodilian species—the most studied of which is the American alligator—both low and high temperatures result in females and intermediate temperatures select for males. A widely held view is that temperature-dependent and genotypic sex determination are mutually exclusive, incompatible mechanisms—in other words, a reptile's sex is never under the influence of both sex chromosomes and environmental temperature. © 1996-2007 Scientific American, Inc.

Keyword: Sexual Behavior
Link ID: 10437 - Posted: 06.24.2010

Andy Coghlan One of the nasty tricks that diabetes has up its sleeve is the ability to carry on harming people long after they have got the level of glucose in their blood under control. Now researchers think they may be able to stop this, using cheap available drugs. The idea builds on the discovery that when cells are exposed to the high levels of glucose typical of diabetes, proteins within the cells' mitochondria suffer damaging changes. The proteins become permanently attached to sugar-like molecules called glycans, and this not only prevents them doing their job properly but also makes them produce harmful molecules called reactive oxygen species. The reactive oxygen species circulate throughout the body, attacking and damaging tissues, particularly in the limbs and eyes. Because the changes to the cellular proteins are not reversible, they continue to pump out these molecules even when glucose levels have returned to normal. "This contributes to the development of diabetic complications," says Antonio Ceriello of the University of Warwick in Coventry, UK, whose team now think there may be a way to stop this happening. The clue came from lab experiments in which they took damaged cells that had been previously exposed to high levels of glucose, and showed that the reactive molecules could be neutralised by exposing the cells to antioxidants such as alpha-lipoic acid (Diabetologia, DOI: 10.1007/s00125-007-0684-2). © Copyright Reed Business Information Ltd.

Keyword: Obesity
Link ID: 10436 - Posted: 06.24.2010

Analyses of a national sample of individuals with alcohol dependence (alcoholism) reveal five distinct subtypes of the disease, according to a new study by scientists at the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health (NIH). "Our findings should help dispel the popular notion of the ‘typical alcoholic,’” notes first author Howard B. Moss, M.D., NIAAA Associate Director for Clinical and Translational Research. “We find that young adults comprise the largest group of alcoholics in this country, and nearly 20 percent of alcoholics are highly functional and well-educated with good incomes. More than half of the alcoholics in the United States have no multigenerational family history of the disease, suggesting that their form of alcoholism was unlikely to have genetic causes.” “Clinicians have long recognized diverse manifestations of alcoholism,” adds NIAAA Director Ting-Kai Li, M.D, “and researchers have tried to understand why some alcoholics improve with specific medications and psychotherapies while others do not. The classification system described in this study will have broad application in both clinical and research settings.” A report of the study is now available online in the journal Drug and Alcohol Dependence. Previous efforts to identify alcoholism subtypes focused primarily on individuals who were hospitalized or otherwise receiving treatment for their alcoholism.

Keyword: Drug Abuse
Link ID: 10435 - Posted: 06.24.2010

By BENEDICT CAREY Taking an antidepressant like Prozac may increase a pregnant woman’s risk of having a baby with a birth defect, but the chances appear remote and confined to a few rare defects, researchers are reporting today. The findings, appearing in two studies in The New England Journal of Medicine, support doctors’ assurances that antidepressants are not a major cause of serious physical problems in newborns. But the studies did not include enough cases to adequately assess risk of many rare defects; nor did they include information on how long women were taking antidepressants or at what doses. The studies did not evaluate behavioral effects either; previous research has found that babies suffer withdrawal effects if they have been exposed to antidepressants in the womb, and that may have implications for later behavior. “These are important papers, but they don’t close the questions of whether there are major effects” of these drugs on developing babies, said Dr. Timothy Oberlander, a developmental pediatrician at the University of British Columbia, who was not involved in the studies. “There are many more chapters in this story yet to be told.” Copyright 2007 The New York Times Company

Keyword: Depression; Development of the Brain
Link ID: 10434 - Posted: 06.24.2010

Symptoms of mental retardation and autism have been reversed for the first time in laboratory mice. US scientists created mice that showed symptoms of Fragile X Syndrome - a leading cause of mental retardation and autism in humans. They then reversed symptoms of the condition by inhibiting the action of an enzyme in the brain. The study, by Massachusetts Institute of Technology, appears in Proceedings of the National Academy of Sciences. Fragile X Syndrome is linked to mutation in a gene carried on the X chromosome called FMR1. It can cause symptoms ranging from mild learning disabilities to severe autism. The researchers, based at MIT's Picower Institute for Learning and Memory, targeted an enzyme called PAK which affects the number, size and shape of connection between brain cells. They found that inhibiting the enzyme stopped mice with Fragile X Syndrome behaving in erratic ways. Prior to treatment they showed signs of hyperactivity, purposeless and repetitive movements. Further analysis showed that not only were structural abnormalities in connections between brain cells righted, proper electrical communication was restored between the cells. In the brain small protrusions called dendritic spines are responsible for communication between cells. People with Fragile X Syndrome have more dendritic spines than usual, but each is longer and thinner, and transmits weaker electric signals. Blocking PAK activity in the lab mice corrected these abnormalities. (C)BBC

Keyword: Autism; Genes & Behavior
Link ID: 10433 - Posted: 06.28.2007

By Melinda Wenner Female timber rattlesnakes tend to be stay-at-home moms while the males wander the streets — sometimes even suburban streets, according to new research. A team of researchers is seeking out these sneaky rattlers, implanting tracking devices inside them and then turning them loose in order to learn more about their behavior. Wayne Drda, a researcher at the Tyson Research Center at Washington University in St. Louis, and his colleagues recently also learned that, contrary to popular belief, timber rattlesnakes are shy and rarely use their rattlers. This is because they are well camouflaged, and rattling gives away their location. They have also found that females and males behave quite differently. While the females stay with their young for up to 10 days after birth, the males prefer to wander around. Most snakes, however, do return to the same sites year after year. Unfortunately for the snakes, their wanderlust — as well as their tendency to pop up in suburban neighborhoods, where families have unknowingly encroached upon their turf — puts them in danger of being killed by fearful residents. © 2007 MSNBC.com © 2007 Microsoft

Keyword: Sexual Behavior
Link ID: 10432 - Posted: 06.24.2010

By NATALIE ANGIER Not long ago, my daughter proposed a way she could earn some extra cash beyond her weekly allowance. Would I give her a quarter, she wanted to know, every time she cleaned the cat box? Twenty-five cents to clean the cat box? I squealed with unconcealed joy. Truly we’d hit commensal pay dirt here. She had fiscal motivation, and I could use the olfactory vacation. But then I read a few items about Toxoplasma gondii, the parasitic protozoa that can be lurking in cat scat, and I changed my mind. I told my daughter that she should skip the litter patrol and try cleaning the refrigerator instead. I’m not normally a fluttering, overprotective mother, and I know that the risk of contracting the toxoplasma pathogen or any serious infectious illness from the cat box is tiny. Still, we’re talking parasites here, and parasitism is an evolutionary force to be reckoned with, a source of nearly bottomless cunning and breathtaking bio-inventiveness. Predators want to kill you and eat you right there on the veldt. Parasites, by contrast, want to keep you alive, the better to serve as a parasite paradise, a cozy haven where they can grow at their own pace, suckle on your moist, nourishing tissues, multiply their numbers and finally, one way or another, pass those numbers along. Toxoplasma, it seems, is a member of a particularly insidious genus of parasite, which seek perpetuity by controlling their hapless hosts’ minds. So maybe I’m hyperventilating here, but if any mind in my house is to be monkeyed with, I would really prefer it be mine. Copyright 2007 The New York Times Company

Keyword: Miscellaneous
Link ID: 10431 - Posted: 06.24.2010

By Michael Shermer Imagine that your child’s private school tuition bill of $20,000 is due and the only source you have for paying it is the sale of some of your stock holdings. Fortunately, you got in on the great Google godsend and purchased 100 shares at $200 each, for a total investment of $20,000, and the stock is now at $400 a share. Should you realize your net gain by selling half of your Google stock and paying off your bill? Or should you sell off that Ford stock you purchased ages ago for $40,000 at its current value of $20,000? If you are like most people (myself included), you would sell your Google stock and hang on to your Ford stock in hopes of recovering your losses. This would be the wrong strategy. Why would you sell shares in a company whose stock is on the rise, and hang on to shares in a company whose stock is on the decline? The reason, in a phrase, is “loss aversion,” and the psychology behind it does not fit the model of Homo economicus, that figurative species of human characterized by unbounded rationality in decision making. Homo economicus is extinct, felled by the new sciences of behavioral economics and neuroeconomics, which have demonstrated that we are remarkably irrational creatures. Thousands of experiments in behavioral economics since Daniel Kahneman and Amos Tversky founded the field with their seminal 1979 paper, “Prospect Theory: An Analysis of Decision under Risk,” have demonstrated that most of us are highly loss averse. Specifically, most people will reject the prospect of a 50–50 probability of gaining or losing money, unless the amount to be gained is at least double the amount to be lost. That is, people feel worse about the pain of a loss than they feel better about the pleasure of a gain. Twice as badly, in fact. © 1996-2007 Scientific American, Inc.

Keyword: Emotions
Link ID: 10430 - Posted: 06.24.2010

Louis Buckley Despite their cumbersome appearance, elephants can run. And, researchers have found, they break into that run at surprisingly slow speeds. Elephants typically stroll along at a leisurely 4 kilometres per hour, explains John Hutchinson of the Royal Veterinary College in London. But once they ramp up to just twice this speed they start to use their back legs "like pogo sticks" to drive their bodies forward, bouncing over their relatively stiff, vaulting forelimbs. This unusual gait counts as running, says Hutchinson, whose study on elephant locomotion is published today in the Journal of the Royal Society Interface1. Hutchinson studied the locomotion of five elephants in safari parks in the United Kingdom. Fitted with four motion sensors — two on their backs, two on their feet — the animals plodded, and in some cases dashed, along a 25-30-metre track, enticed by food rewards and the encouragement of their trainers. The fastest speed clocked up during the experiment was a modest 12.6 kilometres per hour, perhaps suggesting the elephants were a little out of shape. Earlier work by Hutchinson's team in Thailand2 showed that more athletic individuals can reach speeds of up to 24 kilometres per hour, and provided some of the first evidence that elephants can indeed run (as opposed to just walking very quickly) — an issue that had previously been much disputed. But in that study they spotted a running gait only at speeds of more than 16 kilometres per hour. ©2007 Nature Publishing Group

Keyword: Miscellaneous
Link ID: 10429 - Posted: 06.24.2010

IT IS a time parents relish: their child's afternoon nap. But it seems that napping may not be such a good idea after all. Preliminary studies suggest that daytime napping in young children may be linked to poorer sleep and mental functioning than in their peers who only sleep at night. The big question is whether napping is the cause of the problem, or the result. John Harsh at the University of Southern Mississippi in Hattiesburg and his colleagues asked the parents of 738 children aged between 2 and 12 about their children's sleeping habits. Children who took long daytime naps fell asleep at night an average of 39 minutes later and slept later at the weekend than those who did not nap. The effect was more pronounced in older children (over a quarter of 10 to 12-year-olds still took afternoon naps). The problem came during the following week, when children had to wake up at set times to get to school or to meet the demands of their parents' work schedules. The napping children continued to stay up later, meaning they spent less time in bed at night than their counterparts. "Napping children not only had a difficult time getting to bed, they had a harder time falling asleep, and they had a harder time getting up in the morning," says study author Alyssa Cairns, who presented the work at the annual meeting of the Associated Professional Sleep Societies in Minneapolis earlier this month. © Copyright Reed Business Information Ltd.

Keyword: Sleep; Development of the Brain
Link ID: 10428 - Posted: 06.24.2010

By Kim Griggs A young New Zealand scientist has managed to create the world's first large transgenic animal model for Huntington's disease, a devastating neurodegenerative disorder. For her PhD, 25-year-old Jessie Jacobsen from the University of Auckland worked out how to inject into sheep the DNA containing the gene that causes Huntington's. From 150 animals bred at a specialist research facility in South Australia, six sheep were born with the Huntington's gene; and now two are being used to breed a flock. Much of what's known about Huntington's disease comes from studies of the brains of patients who've died from the disease, but little is understood about the early stages of the disease. Huntington's disease affects one person in every 10,000 and the disease causes cell death in the brain, ultimately leading to an inability to walk, talk, think or swallow. It is an insidious disease, as for the first 30 or 40 years of a person's life, there can be no outward signs of the disease's progress. So, it is what happens in those early years that Jacobsen - and the project she is part of - aims to understand. The University of Auckland scientists decided to use sheep because their brain structure is remarkably similar to humans. They also live longer than other laboratory animals such as mice. The researchers, however, will not allow the sheep to develop the symptoms of the disease. Rather, they want to look at what is happening in the brain before symptoms occur. "They will develop the toxic protein like humans do, in exactly the same process; and then the cells will die off, hopefully in a similar pattern; and hopefully we'll be able to discover what's going on," says Jacobsen, who was named New Zealand MacDiarmid Young Scientist of the Year this week. (C) BBC

Keyword: Huntingtons
Link ID: 10426 - Posted: 06.26.2007

Kavita Mishra, Chronicle Staff Writer As the oldest kid in his family, Rich Ha says there's no question he's got more brains than his 17-year-old brother. The 19-year-old San Francisco State University student says his brother is "really smart, but if we had to compare the two, I'd say me." Luckily for Ha, experts wouldn't disagree. Settling nearly a century of debate, researchers in Norway have confirmed what many older siblings have thought all along -- they're smarter. Experts have been split about whether birth order in a family affects intelligence. But after conducting the largest study of its kind, Norwegian researcher Petter Kristensen said the debate is over. "We can dismiss the theory that (intelligence based on birth order) is not a true effect, that it is an artifact," he said. Kristensen and his colleagues, reporting in Thursday's online version of the journal Science, also concluded it doesn't matter if you aren't really the first child. If an older sibling dies young and you end up first in the household, you'll be smarter. © 2007 Hearst Communications Inc.

Keyword: Intelligence
Link ID: 10425 - Posted: 06.24.2010

By CORNELIA DEAN In 1950, in a letter to bishops, Pope Pius XII took up the issue of evolution. The Roman Catholic Church does not necessarily object to the study of evolution as far as it relates to physical traits, he wrote in the encyclical, Humani Generis.” But he added, “Catholic faith obliges us to hold that souls are immediately created by God.” Pope John Paul II made much the same point in 1996, in a message to the Pontifical Academy of Sciences, an advisory group to the Vatican. Although he noted that in the intervening years evolution had become “more than a hypothesis,” he added that considering the mind as emerging merely from physical phenomena was “incompatible with the truth about man.” But as evolutionary biologists and cognitive neuroscientists peer ever deeper into the brain, they are discovering more and more genes, brain structures and other physical correlates to feelings like empathy, disgust and joy. That is, they are discovering physical bases for the feelings from which moral sense emerges — not just in people but in other animals as well. The result is perhaps the strongest challenge yet to the worldview summed up by Descartes, the 17th-century philosopher who divided the creatures of the world between humanity and everything else. As biologists turn up evidence that animals can exhibit emotions and patterns of cognition once thought of as strictly human, Descartes’s dictum, “I think, therefore I am,” loses its force. Copyright 2007 The New York Times Company

Keyword: Miscellaneous
Link ID: 10424 - Posted: 06.24.2010

By Will Dunham WASHINGTON (Reuters) - Two studies published on Monday added to the growing evidence that the most popular class of drugs taken to treat depression may contribute to fragile bones in elderly people. The research focused on a class of antidepressant drugs called selective serotonin reuptake inhibitors. Millions of people, including many elderly, take these drugs, known as SSRIs, which include Eli Lilly and Co's Prozac, known generically as fluoxetine. Two teams of researchers found that older men and women taking SSRIs had more bone loss than those not taking the drugs, which account for more than 60 percent of U.S. antidepressant drug prescriptions. A drop in bone mass can lead to osteoporosis and bone fractures. A team led by Dr. Susan Diem of the University of Minnesota tracked 2,722 women, average age 78, including 198 SSRI users. They measured their bone mineral density five years apart. Those taking the antidepressants experienced a density decrease at the hip of 0.82 percent per year, compared to 0.47 percent per year among those not taking them, the study found. © 1996-2007 Scientific American

Keyword: Depression
Link ID: 10423 - Posted: 06.24.2010

Kerri Smith Humans are often thought of as the only truly altruistic species. We help others out — by giving blood, donating to the poor, or committing to recycling — for no immediate payoff, and often at a cost to ourselves. But evidence is gathering that we might not be alone. Felix Warneken and colleagues at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have shown that chimpanzees will do favours for unrelated chimps - even when they do not get rewarded for it. Previous studies have refuted the idea that chimps are so giving. In 2005, anthropologist Joan Silk of the University of California, Los Angeles, found that when she presented chimps with the choice of getting food just for themselves, or for their entire group, they showed no preference for feeding their pals as well1. But other work has shown that chimps can have a non-selfish streak. In a study published in Science last year2, a Leipzig team reported that chimps would help their human keepers retrieve a pen that they had dropped — an action with no direct benefit for the chimp. That study involved chimps helping out human carers whom they were familiar with — and who had on other occasions provided the chimps with food. To get rid of these complications, the Leipzig team replicated the pen-dropping experiment with unfamiliar humans. As they now report in PLoS Biology3, the chimps still chose to help out. ©2007 Nature Publishing Group

Keyword: Evolution
Link ID: 10422 - Posted: 06.24.2010

By Marissa Cevallos You can tell how nimble an animal is without even looking at its legs: Simply check the size of its inner ear. A new study shows that agile animals, such as tree-swinging gibbons or brown bats, have relatively larger ear canals than their lumbering counterparts the sloths or dugongs, a relative of the manatee. The finding may provide an innovative way to check how quick-footed extinct species were. However, critics point out that in this study, agility is in the eye of the beholder. Organs in the inner ear help steady an animal's motion by synching the body's movement to visual stimuli. The inner ear has three fluid-filled semicircular canals, one circling each spatial dimension, that act like little gyroscopes to detect changes in speed in the direction of motion. Fluids in the semicircular canals flow when an animal jerks its head, in the same way water in a bucket will slosh if you're running with it and suddenly stop. Scientists had noticed that some agile animals, such as graceful gibbons, had larger semicircular canals relative to their body sizes than less maneuverable creatures such as sloths. That would make sense because the bigger hoops should be more sensitive to acceleration, and animals that change direction and speed rapidly have jerkier head motions and experience bigger accelerations. But in spite of anecdotal evidence, it wasn't clear that larger canals always belonged to quicker creatures. To test the pattern, paleontologist Alan Walker of Pennsylvania State University in State College and his team surveyed more than 200 mammals. © 2007 American Association for the Advancement of Science

Keyword: Evolution
Link ID: 10421 - Posted: 06.24.2010

Katharine Sanderson Eldest sibblings are, on average, 2.3 IQ points more intelligent than their younger brothers and sisters, says a study of Norweigan kids. And it's not necessarily being born first that makes the difference — it's being raised as the eldest child. It has been proposed for some time that, on average across a population, first-borns are more intelligent than their younger brethren. There are more first-born sons in prominent positions than might be expected, for example. And some studies have shown a link between birth order and intelligence: the later born, the less smart the child. But the reasons behind this trend, and even whether it's real, have been hotly debated. Families with low-intelligence children tend to be large (perhaps a big brood leaves little time for helping with homework), so the observation that sixth-born children aren't very smart, for example, could just be a side effect of this, critics have said. Petter Kristensen, from the University of Oslo, and Tor Bjerkedal from the Norwegian Armed Forces Medical Services in Oslo looked at data gathered from 241,310 Norwegian kids, all aged 18 or 19 years old at the time of intelligence testing. ©2007 Nature Publishing Group

Keyword: Intelligence
Link ID: 10420 - Posted: 06.24.2010