April 6, 2009, 10:18 PM CT

3-year-olds get the point

Dogs and small children who share similar social environments appear to understand human gestures in comparable ways, as per Gabriella Lakatos from Eotvos University in Budapest, Hungary, and her team. Looking at how dogs and young children respond to adult pointing actions, Lakatos shows that 3-year-olds rely on the direction of the index finger to locate a hidden object, whereas 2-year-olds and dogs respond instead to the protruding body part, even if the index finger is pointing in the opposite direction. These findings1 were just published online in Springer's journal Animal Cognition.

It is widely accepted that in the course of domestication, dogs became predisposed to read human communication signals, including pointing, head turning and gazing. Furthermore, the social environment of human infants is often shared by pet dogs in the family, and therefore there are likely to be similarities in the social stimulation of both young children and dogs.

The authors carried out two studies in which they compared the performance of adult dogs and 2-and 3-year-old children - the period of human development during which children and dogs respond in similar ways. They investigated whether dogs and human children are able to generalize from familiar pointing gestures to unfamiliar ones and whether they understand the unfamiliar pointing actions as directional signals......... Posted by: Emily      Read more         Source

April 6, 2009, 10:16 PM CT

Young adults at future risk of Alzheimer's have different brain activity

Young adults with a genetic variant that raises their risk of developing Alzheimer's Disease show changes in their brain activity decades before any symptoms might arise, as per a new brain imaging study by researchers from the University of Oxford and Imperial College London. The results may support the idea that the brain's memory function may gradually wear itself out in those who go on to develop Alzheimer's.

The research, published recently in the journal Proceedings of the National Academy of Sciences, provides clues as to why certain people develop Alzheimer's Disease (AD) and it appears to be a step towards a diagnostic test that identifies individuals at risk. The degenerative condition is the most common cause of dementia and it affects around 417,000 people in the UK.

The APOE4 genetic variant is found in about a quarter of the population. Not everyone who carries the variant will go on to develop AD, but people who inherit one copy of APOE4 have up to four times the normal risk of developing the late-onset variety of the disease. People who have two copies have around ten times the normal risk.

The scientists behind today's study stress that most carriers of APOE4 will not go on to develop Alzheimer's and carriers should not be alarmed by the study's findings......... Posted by: Emily      Read more         Source

April 6, 2009, 9:27 PM CT

Humans need not apply?

As science fiction plot lines go, the unintended consequences of yielding tasks too complicated or dangerous for human hands to computers and robots is a popular one. Yet real life researchers are increasingly doing just that, creating automated systems and devices that can not only help collect, organize and analyze scientific data, but that are also able to intelligently and independently draw up new hypotheses and approaches to research based on the data they receive.

In a perspectives piece in tomorrow's edition of the journal Science, David Waltz of the Center for Computational Learning Systems at Columbia University and Bruce G. Buchanan of the computer science department at the University of Pittsburgh discuss this brave new world of scientific research and its implications for the way science is conducted. They see this all as a promising trend, but caution that scientists need to consider what tasks are best suited for automation and which should be left to the human mind.

Waltz and Buchanan point out that computer-aided automation has been a part of scientific research for decades, from simple programs that plotted ballistic arcs to databases that held and organized scientific data. All of these systems, however, mandatory a "human in the loop" to shape the research, examine the results and determine how to apply the outcome to future endeavors......... Posted by: Emily      Read more         Source

April 2, 2009, 10:10 PM CT

Mentoring programs for adolescent girls

A study of a Big Brothers Big Sisters of America formal mentoring program, which matched adolescent girls with women mentors, revealed that strong emotional support and improvement in girls psychosocial functioning from these relationships was a dominant theme coupled with the development of new skills and confidence through collaborations.

Unlike prior mentoring studies, this one explicitly examined the relational processes in adolescent girls' relationship with female adult mentors from the perspective of the participants themselves. Each adolescent and mentor pair was extensively interviewed separately and then together. Their recorded comments were analyzed and revealed that girls benefit from both skill development and gain vital emotional support.

Those findings are reported in the Journal of Primary Prevention in a study led by Renee Spencer, an assistant professor at Boston University School of Social Work and Belle Liang, an associate professor at Boston College that was published last month.

"In the absence of much research on gender in mentoring, a number of have assumed that boys are mostly interested in doing activities with male mentors, which, by nature, appears to be more focused on skill building and problem solving whereas girls are more interested in developing emotionally-focused relationships with mentors," said Spencer. "However, in our study, we observed that these girls' relationships with their mentors offered both emotional support and opportunities to develop skills and confidence through collaborations with their mentors in shared activities, such as doing homework together or learning to sing." ......... Posted by: Emily      Read more         Source

April 2, 2009, 5:24 AM CT

Effects of climate change on infectious diseases

Recent research has predicted that climate change may expand the scope of human infectious diseases. A new review, however, argues that climate change may have a negligible effect on pathogens or even reduce their ranges. The paper has sparked debate in the ecological community.

In a forum in the recent issue of Ecology, Kevin Lafferty of the U.S. Geological Survey's Western Ecological Research Center suggests that instead of a net expansion in the global range of diseases, climate change may cause poleward range shifts in the areas suitable for diseases as higher latitudes become warmer and regions near the equator become too hot.

The newly suitable areas for diseases will tend to be in more affluent regions where medicines are in widespread use and can more readily combat the diseases, Lafferty says. He cites model estimations that the most dangerous kind of malaria will gain 23 million human hosts outside of its current range by the year 2050, but will lose 25 million in its current range.

"The dramatic contraction of malaria during a century of warming suggests that economic forces might be just as important as climate in determining pathogen ranges," Lafferty says.

Mercedes Pascual of the University of Michigan sees the situation very differently. Pascual is the lead author of one of five Forum papers published in response to Lafferty. Although she agrees that disease expansion in some areas could be accompanied by retraction in others, she emphasizes that disease range does not always correlate with the number of humans infected. In regions of Africa and South America, for example, humans have historically settled in high latitudes and altitudes. If climate change makes these areas more fit for mosquito breeding and for pathogen development, she writes, then a number of infections could expand. She notes that scientists are already seeing evidence of this pattern......... Posted by: Emily      Read more         Source

March 31, 2009, 5:28 AM CT

Mice and men should have more in common

Just as no two humans are the.

same, a Purdue University scientist has shown treating mice more as individuals in laboratory testing cuts down on erroneous results and could significantly reduce the cost of drug development.

Mice have long been used as test subjects for therapys and drugs before those products are approved for human testing. But new research shows that the customary practice of standardizing mice by trying to limit environmental variation in laboratories actually increases the chance of getting an incorrect result.

The study, done by Joseph Garner, a Purdue assistant professor of animal sciences, and professor Hanno Würbel of the Justus-Liebig University of Giessen in Gera number of, was reported in the early online edition of Nature Methods on Monday (March 30). It suggests researchers should change their methods and test mice in deliberately varying environmental conditions. Garner said that will decrease the number of false positive test results and eliminate further costly testing of drugs or therapys destined to fail.

"In lab animals, we have this bizarre idea that we can control everything that happens," Garner said. "But we would never be able to do that with humans, and we wouldn't want to. You want to know if a drug is going to work in all people, so you test it on a wide range of different people. We should do the same thing with mice"......... Posted by: Emily      Read more         Source

March 30, 2009, 5:17 AM CT

Transmission of drug resistant HIV-1

Drug-resistant forms of HIV can be spread between individuals who have not received anti-retroviral therapy, as per Professor Deenan Pillay from University College, London and the Health Protection Agency, speaking at the Society for General Microbiology meeting at Harrogate today, (Monday 30 March).

Anti-retroviral treatment is a major advance in the therapy of HIV and there are currently over 25 drugs available. It is known that the virus can mutate, reducing its susceptibility to therapy, and that these resistant viruses can be transmitted between individuals. Professor Pillay observed that drug resistant viruses could also circulate between individuals who have not received antiretroviral drugs therapys.

"Our findings show that assuming that drug resistant HIV was only passed on from individuals receiving drug therapy may mean the number and size of the reservoirs of drug resistant virus in the United Kingdom has been underestimated," said Pillay, "Our results indicate that eventhough the occurence rate of drug resistance has been declining, this might not continue - which could have implications for planning and management of therapy programmes"......... Posted by: Emily      Read more         Source

March 26, 2009, 9:32 PM CT

Individualized Stroke Treatment

Nearly 90 percent of the 700,000 strokes that affect U.S. patients each year are caused by a blockage of blood vessels supplying the brain, known as ischemic stroke. A newly released study published in Catheterization and Cardiovascular Interventions, the official journal of The Society for Cardiovascular Angiography and Interventions (SCAI), provides solid evidence of the effectiveness of catheter-based treatment (CBT) to remove blood clots in stroke patients. CBTs, which include stents and thrombectomy, appears to be used for ischemic stroke patients who arrive too late or have contraindications for intravenous thrombolysis, a drug therapy frequently used to break down blood clots.

Strokes are the third leading cause of death in the U.S. and the most common cause of adult disability. To be effective, intravenous thrombolysis must be administered less than three hours after the onset of stroke symptoms. Unfortunately, and despite efforts to educate the public on the warning signs of stroke and the need to seek therapy quickly, most patients arrive at the emergency room too late. It is estimated that less than 5 percent of patients are eligible for this therapy which has prompted interest in alternative therapies, like CBT, that restore blood flow.

CBT applies the same therapy model for identifying a blocked artery causing a heart attack to stroke treatment. It allows the doctor to tailor the therapy based on the location and characteristics of the blockage. "We believe the individualized therapy that can be offered with this approach optimizes patient outcomes and minimizes risk," says Dr. Christopher J. White, co-author of the study......... Posted by: Emily      Read more         Source

March 25, 2009, 10:04 PM CT

Arsenic-poisoning crisis in Asia

Every day, more than 140 million people in southern Asia drink groundwater contaminated with arsenic. Thousands of people in Bangladesh, Cambodia, India, Myanmar and Vietnam die of cancer each year from chronic exposure to arsenic, as per the World Health Organization. Some health experts call it the biggest mass poisoning in history.

More than 15 years ago, researchers pinpointed the source of the contamination in the Himalaya Mountains, where sediments containing naturally occurring arsenic were carried downstream to heavily populated river basins below.

But one mystery remained: Instead of remaining chemically trapped in the river sediments, arsenic was somehow working its way into the groundwater more than 100 feet below the surface. Solving that mystery could have significant implications for policymakers trying to reverse the mass poisoning, said Stanford University soil scientist Scott Fendorf.

"How does the arsenic go from being in the sediment loads, in solids, into the drinking water?" said Fendorf, a professor of environmental Earth system science and a senior fellow at Stanford's Woods Institute for the Environment.

To find out, he launched a field study in Asia in 2004 with two Stanford colleagues: Chris Francis, an assistant professor of geological and environmental sciences, and Karen Seto, now at Yale University. The initial study was funded with a two-year Woods Institute Environmental Venture Projects grant. Five years later, the research team appears to have solved the arsenic mystery and is working with policymakers and government officials to prevent the health crisis from escalating......... Posted by: Emily      Read more         Source

March 22, 2009, 10:03 PM CT

Light to moderate drinking and socialization

While heavy drinking is linked to a greater risk of stroke, light-to-moderate drinking has been associated with a lesser risk of ischemic stroke and coronary heart disease. Other studies have shown that more social support is associated with less risk of mortality and cardiovascular disease. A Japanese examination of the effects of social support on the relationship between drinking and cardiovascular disease has observed that the health benefits of light-to-moderate drinking are more pronounced in men with greater social support.

Results would be reported in the recent issue of Alcoholism: Clinical & Experimental Research and are currently available at Early View.

"In Japan, drinking is divided into two main patterns," said Hiroyasu Iso, a professor of public health at Osaka University and corresponding author for the study. "One pattern is drinking alone and/or with family at home during the evening. Another pattern particularly for middle-aged business men is social drinking with co-workers, friends, and neighbors. Social drinking is common".

"Alcohol can play a key role," concurred Takeshi Tanigawa, a professor in the department of public health at Ehime University Graduate School of Medicine, "for socializing as well as some business discussions. In urban areas, alcohol consumption is often used as a business tool. In rural areas, people often have a drink with classmates and people in the same community. Alcohol consumption can be used to maintain human relationships between father and son, senior and junior, community to community. Collectively, these socializing customs may help to create a stress-free space for those persons surrounded by dozens of stresses, particularly in the workplace."........ Posted by: Emily      Read more