By Laura Blackburn If a guy wants to smell nice for his lady, a splash of aftershave or cologne usually does the trick. Male lizards take a slightly different approach. They eat vitamins. When it comes to choosing a mate, female animals scope out the healthiest and most fertile males. Sometimes appearance matters most; the colorful tail of a male peacock, for example, attracts predators--so surviving males are judged fit enough to escape their enemies. A male's odor may also tag him as a good catch, but scientist’s aren't as clear on how this works. Evolutionary ecologists José Martín and Pilar López of the National Museum of Natural Sciences in Madrid, Spain, wondered if rock lizards could provide an answer. Male Iberian rock lizards (Lacerta monticola) mark their territory with a secretion from their leg glands that contains provitamin D (a precursor to vitamin D). Like humans, lizards need vitamin D for strong bones. Healthy males on a good diet have an abundance of vitamin D and can therefore afford to secrete some of it as provitamin D. Can female lizards pick up on this lavish "spending?" © 2006 American Association for the Advancement of Science.

Keyword: Sexual Behavior; Chemical Senses (Smell & Taste)
Link ID: 9154 - Posted: 06.24.2010

Jennifer Viegas, Discovery News — We can thank our verbal nature, along with our fingers, for the ability to develop complex number systems, a new study suggests. The study's authors theorize that language and math co-evolved in humans, with language probably emerging just ahead of basic mathematical concepts. “I do not think counting words were among the first words spoken by our species, because their application makes use of a fairly sophisticated pattern of linking that occurred ... relatively late in linguistic evolution,” said Heike Wiese, who authored the study. Wiese, a linguist at the University of Potsdam in Germany, explained to Discovery News that our use of counting words, and numbers in general, likely emerged in four stages. During the first stage, Wiese believes humans began using visual representations — such as symbols or other markings — to correspond with verbal indications of quantity. Among the early evidence for that stage is a 30,000-year-old wolf bone, excavated in the Czech Republic, with notched tallies cut into it. © 2006 Discovery Communications Inc.

Keyword: Language
Link ID: 9153 - Posted: 06.24.2010

Roxanne Khamsi New evidence adds weight to the theory that one of the most deadly forms of brain cancer, called malignant glioma, is caused when stem cells deep within the brain begin to proliferate abnormally, researchers have announced. Special receptors on the surfaces of these cells trigger cancerous cell division in response to a particular growth hormone, the team's experiments in mice reveal. Absence of this hormone caused such tumours to shrink, they discovered, raising hopes for a potential treatment. When diagnosed with malignant gliomas, the sufferer typically has just 14 months to live. There is currently no effective treatment for the fast-spreading illness. Arturo Alvarez-Buylla at the University of California in San Francisco, US, and colleagues conducted post-mortem examinations of the brains of three people without the illness. Chemical tests on nerve stem-cells in a deep region of the brain, known as the sub-ventricular zone, revealed the existence of receptors for a growth hormone known as PDGF on the cell surfaces. The PDGF receptors on these stem cells are the same as those found in cells from malignant brain tumours, comments Charles Stiles of the Dana-Farber Cancer Institute in Boston, Massachusetts, US. He says this strengthens the argument that malignant gliomas result when brain stem cells regenerate abnormally. © Copyright Reed Business Information Ltd.

Keyword: Glia
Link ID: 9152 - Posted: 06.24.2010

Breastfeeding may be the ultimate natural painkiller for newborn babies. A review of research found that breastfeeding newborns helps relieve the pain from a needle prick used to screen their blood for disease. Breastfed babies appeared to experience less pain than those who were swaddled, given a pacifier, or a placebo. Comfort from a mother's presence may be key. The Cochrane Library review, by Toronto's Mount Sinai Hospital, was based on data from over 1,000 babies. The researchers say that breastfeeding could possibly help relieve pain for premature babies who need to undergo many painful intensive care procedures. However, they stress that their study did not test the impact of breastfeeding on the pain associated with repeated procedures. The Mount Sinai team assessed pain by measuring changes in heart and breathing rates, and the length of time a baby cried after receiving the needle prick. The researchers say that the key to the effect of breastfeeding may be that an infant simply draws comfort from the close proximity of its mother. Alternatively, breastfeeding may help to divert attention away from the pain of a needle prick. They also suggest that the sweetness of breast milk may be a factor. Another theory is that breast milk contains a high concentration of a chemical which could ultimately trigger the production of natural painkillers called endorphins. The researchers also found that giving babies a sugar solution seemed to be effective. (C)BBC

Keyword: Pain & Touch
Link ID: 9151 - Posted: 07.19.2006

Scientists know that children of women who smoke during pregnancy can develop hearing-related cognitive deficits. For the first time, researchers believe they have evidence that not only implicates nicotine as the culprit, but also shows what the substance does to the brain to cause these deficits. In a study using rats, Raju Metherate, associate professor of neurobiology and behavior, and colleagues from UC Irvine, showed that nicotine exposure during the equivalent of a human’s third trimester led to hearing-related cognitive problems. This is the first time a study has demonstrated this causal link. Further tests then revealed that the probable cause of the deficits was damage to the receptors in the brain that are sensitive to nicotine, which seems to occur when humans or animals are exposed to the substance during development. The study appears this week in the early online issue of the European Journal of Neuroscience. Children with auditory processing deficits can have a number of hearing-related problems. They may have difficulty understanding speech in a noisy environment, not understand information that is presented verbally, and may not be able to tell the difference between similar sounds. © Copyright 2002-2006 UC Regents

Keyword: Hearing; Drug Abuse
Link ID: 9150 - Posted: 06.24.2010

(Baltimore, MD) -- Differences in the way men and women perform verbal and visuospatial tasks have been well documented in scientific literature, but findings have been inconsistent as to whether men and women actually use different parts of their brains. This inconsistency has been attributed to many factors, including variability in the tasks used in studies and failure to match study participants on performance equivalency. But a new study published in the journal Brain and Language, which accounted for and corrected these methodological factors, confirmed that men and women do indeed use different parts of their brains when processing both language and visuospatial information. At a time when 37% of boys score below basic levels on standardized academic tests, compared to 15% of girls (National Center for Education Statistics) and the rate of ADHD in boys in twice that of girls (Centers for Disease Control), this study provides a solid benchmark to use in comparing whether underlying sex differences also exist in all children. Such an inquiry can pave the way towards understanding the extent to which sex differences are developmental, sociological and/or hormonal and which differences may become more, or possibly less, distinct with age. The study, led by Dr. Laurie Cutting and research scientist Amy Clements, both of the Kennedy Krieger Institute in Baltimore, used functional magnetic resonance imaging to study thirty adult participants while performing language and visuospatial tasks. Distinct differences were evident between male and female participants.

Keyword: Sexual Behavior; Laterality
Link ID: 9149 - Posted: 07.19.2006

Ian Sample, science correspondent Autistic men have striking abnormalities in a region of the brain that deals with social skills, according to research published today. Detailed maps of autistic men's brains show they have substantially fewer neurons than expected in a region called the amygdala, which plays a major role in understanding others' actions and emotions. The finding adds weight to a theory put forward by some scientists that stunted development in the amygdala gives rise to autism. Further research is needed, however, to confirm whether the lack of neurons is a direct cause of autism, or is merely a consequence of it. Scientists at the University of California, Davis studied the brains of 19 dead men, nine of whom had autism. Using a technique called stereological analysis, they were able to count the numbers of neurons in different parts of the men's brains and compare them. The researchers found abnormally low numbers of brain cells in the almond-shaped amygdala and a structure known as its lateral nucleus. "This is the first quantitative evidence of an abnormal number of neurons in the autistic amygdala," said David Amaral, who led the research, which appears in the Journal of Neuroscience. © Guardian Newspapers Limited 2006

Keyword: Autism
Link ID: 9148 - Posted: 06.24.2010

By BENEDICT CAREY Resigning yourself to old age may produce the very mental lapses that most people fear will strike them in their golden years. In a paper appearing in the current issue of the journal Social Cognition, psychologists report that men and women in late middle age underperformed on a standard memory test when told they were part of a study including people over age 70. Inclusion with an older group — an indirect reminder of the link between age and memory slippage — was enough to affect their scores, especially for those who were most concerned about getting older, the authors concluded. Researchers refer to this self-undermining as a stereotype effect, and they have documented it in many groups. In studies, women perform less well on math exams after reading that men tend to perform better on them. Similarly, white men perform less well when they are told that they are competing in math against Asian students. People over 65 also slump on memory tests when they are reminded of the link between age and mental decline. The new study, financed by the National Institute on Aging, is the first to show the effect so clearly in a borderline group, experts say — middle age is certainly not young, but it is well short of “senior.” Copyright 2006 The New York Times Company

Keyword: Alzheimers
Link ID: 9147 - Posted: 06.24.2010

By Sandra G. Boodman Some doctors call it "the other f-word" -- a problem they see on a daily basis but many are reluctant to address: kids who are too fat. The issue is not new, but experts say it has acquired greater urgency as obesity has ballooned in the past 25 years, accompanied by sharp increases in diabetes, hypertension and high cholesterol, conditions that used to be largely the province of those middle-aged or older. In 1980, according to the federal Centers for Disease Control and Prevention (CDC), 7 percent of children and 5 percent of teenagers were overweight; today the figures hover around 19 percent and 17 percent, respectively. Doctors at Children's National Medical Center in Washington, where 38 percent of patients are obese, say that in recent years they have treated a 9-year-old who suffered a heart attack, a child with a body mass index of 52 (a 5-foot-6 adult with a BMI of 52 would weigh 322 pounds) and several others so dangerously fat that they underwent gastric bypass surgery. So why are many doctors reluctant to mention an obvious problem? © 2006 The Washington Post Company

Keyword: Obesity; Development of the Brain
Link ID: 9146 - Posted: 06.24.2010

By NICHOLAS BAKALAR Some people never forget a face. Heather Sellers never remembers one. She finds it almost impossible to recognize people simply by looking at them. She remembers the books she reads as well as anyone else, but movies and TV shows are impossible to follow because all of the actors’ faces seem so similar. She can recall a name or a telephone number with ease, but she is unable to remember her own face well enough to pick it out in a group photograph. Dr. Sellers, a professor of English at Hope College in Holland, Mich., has a disorder called prosopagnosia, or face blindness, and she has had it since birth. “I see faces that are human,” she said, “but they all look more or less the same. It’s like looking at a bunch of golden retrievers: some may seem a little older or smaller or bigger, but essentially they all look alike.” Face blindness can be a rare result of a stroke or a brain injury, but a study published in the July issue of The American Journal of Medical Genetics Part A is the first report of the prevalence of a congenital or developmental form of the disorder. Copyright 2006 The New York Times Company

Keyword: Miscellaneous
Link ID: 9145 - Posted: 06.24.2010

By Marie McCullough Over the centuries, coffee has been cursed for making soldiers undependable, women infertile, peasants rebellious, and worse. In England in 1674, for example, the anonymous authors of the Women's Petition Against Coffee complained that they were suffering in the bedroom because men were constantly in coffeehouses, slurping that "nauseous Puddle-water": "That Newfangled, Abominable, Heathenish Liquor called COFFEE... has... Eunucht our Husbands... that they are become as Impotent as Age." Makes you wonder what those guys were putting in their daily grind besides cream and sugar. The point is, coffee has always been more than a beverage, and its health effects have always been controversial. After all, coffee is chock-full o' the drug 1,3,7-trimethylxanthine - better known as caffeine (even decaf has caf) - plus a wholelatte other chemicals and additives. Recently, the buzz on brew has been good. Glug enough of it, research suggests, and you'll lower your risk of diabetes, liver cirrhosis, Parkinson's disease, gallstones and suicide. You'll also sprint better. But not long ago, in the 1970s and '80s, coffee's name was mud. It was connected - tenuously or incorrectly, experts now say - to pancreatic cancer, heart attacks, birth defects, miscarriage, osteoporosis, and other ill effects. The surprising thing is that even after a thousand years, this ubiquitous liquid remains quite mysterious. So sit back, sip some drip, and ponder the latest research:

Keyword: Drug Abuse
Link ID: 9144 - Posted: 07.18.2006

By Briahna Gray It's said that if you're lucky, you'll grow old gracefully, accepting with aplomb the wrinkles, hair loss, and organ failure that come with age. However, these characteristics may not be the result of natural wear and tear. A new study published 19 July in Genes and Development suggests that how we age may be linked to a gene that, until now, was only thought to be involved with the body's internal clock. Scientists first noticed connection between aging and circadian rhythms in mice bred to lack a gene known as BMAL1. BMAL1 is part of the molecular machinery that keeps the body in synch with the daily rising and setting of the sun, and mice that lack the gene had irregular activity patterns--using their running wheel at strange times of day, for example. The mice also seemed to die a lot sooner than normal mice, but until now, no one had done a formal study to investigate why. To see if BMAL1 plays a role in aging, Marina Antoch, a molecular biologist at the Lerner Research Institute in Cleveland, Ohio, and her team observed a group of 30 BMAL1 knockout mice. The knockout mice lived only half as long as 30 normal mice did, the researchers found. They also found that the knockout mice aged at an accelerated rate: By 18 weeks of age, the knockouts had lost a significant amount of fat, muscle, and bone mass. They also exhibited organ shrinkage in their spleens, kidneys, hearts, lungs, and testes--all signs of aging. And, like older humans, the BMAL1 mice lost hair and developed cataracts in one or both eyes. © 2006 American Association for the Advancement of Science.

Keyword: Biological Rhythms
Link ID: 9143 - Posted: 06.24.2010

Scientists have discovered genetic mutations that cause a form of familial frontotemporal dementia (FTD), a finding that provides clues to the underlying mechanism of this devastating disease and that may provide insight for future approaches to developing therapies. The mutations are contained in a single gene that scientists can now identify as responsible for a large portion of inherited FTD. A rare brain disorder, FTD usually affects people between ages 40 and 64 with symptoms that include personality changes and inappropriate social behavior. Published online July 16, 2006, in Nature, the research was funded by the National Institute on Aging (NIA), part of the National Institutes of Health (NIH). The discovery builds on a 1998 finding of mutations in another gene that is responsible for a smaller proportion of inherited FTD cases. Amazingly, both the gene found in 1998 and the newly found gene were found on the same region of chromosome 17. Today’s discovery appears to explain all the remaining inherited FTD cases linked to genes on chromosome 17 and may provide new insights into the causes of the overall disease process. Geneticist Michael Hutton, Ph.D., of the Mayo Clinic College of Medicine, Jacksonville, Fla., led an international scientific team to discover the new gene. “This new finding is an important advance in our understanding of frontotemporal dementia,” says NIA director Richard J. Hodes. “It identifies a mutation in the gene producing a growth factor that helps neurons survive, and it suggests that lack of this growth factor may be involved in this form of frontotemporal dementia.”

Keyword: Alzheimers; Genes & Behavior
Link ID: 9142 - Posted: 06.24.2010

By DENISE GRADY Several new studies suggest that diabetes increases the risk of Alzheimer’s disease, adding to a store of evidence that links the disorders. The studies involve only Type 2 diabetes, the most common kind, which is usually related to obesity. The connection raises an ominous prospect: that increases in diabetes, a major concern in the United States and worldwide, may worsen the rising toll from Alzheimer’s. The findings also add dementia to the cloud of threats that already hang over people with diabetes, including heart disease, strokes, kidney failure, blindness and amputations. But some of the studies also hint that measures to prevent or control diabetes may lower the dementia risk, and that certain diabetes drugs should be tested to find whether they can help Alzheimer’s patients, even those without diabetes. Current treatments for Alzheimer’s can provide only a modest improvement in symptoms and cannot stop the progression of the disease. The new findings were presented yesterday by the Alzheimer’s Association at a six-day conference in Madrid attended by 5,000 researchers from around the world. Alzheimer’s affects 1 in 10 people over age 65, and nearly half of people over 85. About 4.5 million Americans have it, and taking care of them costs $100 billion a year, according to the association. The number of patients is expected to grow, possibly reaching 11.3 million to 16 million by 2050, the association said. Copyright 2006 The New York Times Company

Keyword: Alzheimers
Link ID: 9141 - Posted: 06.24.2010

Houston, – In the second it takes you to read these words, tens of thousands of vesicles in your optic nerves are released in sequence, opening tiny surface pores to pass chemical signals to the next cell down the line, telling your brain what you're seeing and your eyes where to move. Thanks to two new studies – including one spearheaded by an undergraduate biochemistry student at Rice University and published online today by Nature Structural and Molecular Biology – scientists have defined the function of a key protein that nerve cells use to pass information quickly. Like all cells in our bodies, nerve cells are encased in a membrane, a thin layer of fatty tissue that walls off the outside world from the cell's interior. And like other cells, nerve cells use a complex system of proteins as sensors, switches and activators to scan the outside world and decide when to open membrane doorways to take in food, expel waste and export chemical products to the rest of the body. Many studies suggest that a group of proteins called SNAREs act like the cell's loading dock managers, deciding when to open the door to release shipments of chemical freight. SNAREs form a docking bay for cartons of chemicals encased in their own fatty membranes. "Nerve cells are one of the few cells in our bodies in which vesicles are prepositioned at the cell membrane, because they have to be ready to release neurotransmitter to the next nerve cell at a moment's notice," said principal researcher James McNew, assistant professor of biochemistry and cell biology.

Keyword: Miscellaneous
Link ID: 9140 - Posted: 06.24.2010

Susan Milius Meerkats are natural teachers—one of the few animals other than people so far shown to have the knack, say researchers. Older hunters gradually introduce pups to the art of eating dinner before it runs away, reports Alex Thornton of the University of Cambridge in England. In the July 14 Science, he and his Cambridge colleague Katherine McAuliffe argue that these interactions meet the criteria for teaching. "It's really important to understand simple forms of teaching if we're going to understand how human teaching evolved," says Thornton. The definition of teaching that Thornton and McAuliffe use requires that in the presence of pupils, the teacher does something special or performs a task less efficiently than it would on its own and that the pupils learn faster than they would without the teacher's activity. Researchers previously argued that a British species of ant meets these criteria. To test these ideas in meerkats, Thornton and McAuliffe worked with animal groups in the Kalahari Desert, including the animals now starring in the television series Meerkat Manor. ©2006 Science Service.

Keyword: Development of the Brain; Sexual Behavior
Link ID: 9139 - Posted: 06.24.2010

Gorillas have been seen for the first time using simple tools to perform tasks in the wild, researchers say. Scientists observed gorillas in a remote Congolese forest using sticks to test the depth of muddy water and to cross swampy areas. Wild chimps and orangutans also use tools, suggesting that the origins of tool use may predate the evolutionary split between apes and humans. Gorillas are endangered, with some populations numbered in the hundreds. "We've been observing gorillas for 10 years here, and we have two cases of them using detached objects as tools," said Thomas Breuer, from the Wildlife Conservation Society (WCS), who heads the study team in Nouabalé-Ndoki National Park in the Republic of Congo. "In the first case, we had a female crossing a pool; and this female has crossed this pool by using a detached stick and testing the water depth, and trying to use it as a walking stick," he told the BBC. The second case saw another female gorilla pick up the trunk of a dead shrub and use it to lean on while dredging for food in a swamp. She then placed the trunk down on the swampy ground and used it as a bridge. "What's fascinating about these observations is the similarity between what these creatures have done, and what we do in the context of crossing a pond," observed Dr Breuer. "The most astonishing thing is that we have observed them using tools not for obtaining food, but for postural support." (C)BBC

Keyword: Evolution
Link ID: 9138 - Posted: 07.15.2006

The regions in robins' brains responsible for singing and mating are shrinking when exposed to high levels of DDT, says new University of Alberta research--the first proof that natural exposure to a contaminant damages the brain of a wild animal. "These residues have been persisting since the late 1960s--that's what is really disturbing," said Dr. Andrew Iwaniuk, a post-doctoral research fellow in the U of A's Department of Psychology. "It has been years since it has been used and still has this effect." The new research, published in Behavioural Brain Research, strongly suggests that exposure to environmental levels of DDT causes significant changes in the brains of songbirds. Previous studies have suggested that exposure to DDT residues affect the brain, but none have actually demonstrated it. The research team, including Iwaniuk's supervisor, psychology professor and Tier II Canada Research Chair Douglas Wong-Wylie, used American Robins to test the idea. Birds are more susceptible to the effects of pesticide residues and other contaminants in the environment than other animals. As well, American robins are often exposed to high levels of DDT and other chemicals because they rely heavily on earthworms as part of their diet. They specifically chose these birds in the Okanagan Valley because at that location they are exposed to high levels of DDT, but relatively low levels of other chemicals.

Keyword: Neurotoxins; Development of the Brain
Link ID: 9137 - Posted: 07.15.2006

Roxanne Khamsi Living alone doubles the risk of heart disease, suggests the largest prospective study so far to examine a possible link. But the same research also suggests that divorce may do the heart some good – but only for women. Kirsten Nielsen of the Aarhus Sygehus University Hospital in Aarhus, Denmark, and colleagues used information from their national health database on people aged 30 to 69 living in Aarhus. They also examined these individuals’ health records from 2000 to 2002. The team hoped to understand the risk factors that predispose people to a form of heart disease known as acute coronary syndrome, which includes heart attacks and sudden cardiac death. Of over 138,000 people studied, 646 were diagnosed with acute coronary syndrome. Men above the age of 50, and women above 60, who lived alone were particularly at risk. Despite constituting just 8% of the whole study population, these groups accounted for more than 96% of all deaths within a month of a positive diagnosis, Nielsen notes. Overall, the risk of acute coronary syndrome among those who lived alone was double that of those who lived with someone else. However, the 10,000 or so divorced women had a 40% reduced risk of the syndrome, compared with women who were not divorced. But the researchers say they do not know what how many of the divorced women in their study were remarried. © Copyright Reed Business Information Ltd.

Keyword: Stress; Neuroimmunology
Link ID: 9136 - Posted: 06.24.2010

Silk may be able to help repair damaged nerves, according to scientists. The UK researchers have shown how nerve cells can grow along bundles of a special fibre, which has properties similar to spider silk. They hope the silk will encourage cell re-growth across severed nerves, possibly even in damaged spinal cords. A picture of nerve cells growing on the silk is one of the winning images in this year's Wellcome Trust Biomedical Image Awards. It is one of 26 images - many revealing objects invisible to the naked eye - captured from medical research programmes across Britain. The silk, dubbed Spidrex, comes from silk worms that have been modified to give the fibres special properties that help cells to bind. Professor John Priestley, a neuroscientist from Queen Mary's School of Medicine and Dentistry, London, and lead researcher, said the silk acted as a scaffold on which nerve cells could grow. The team has tested the silk in tissue culture (shown in the winning image) and in animals - and in both cases, said Professor Priestly, the results had been good. (C)BBC

Keyword: Regeneration
Link ID: 9135 - Posted: 07.13.2006