February 9, 2007, 4:31 AM CT
Restless Legs Syndrome And Compulsive Gambling
A new Mayo Clinic study is the first to describe this compulsive gambling in RLS patients who are being treated with medications that stimulate dopamine receptors in the brain. The Mayo Clinic report appeared in the Jan. 23 issue of Neurology http://www.neurology.org.
The extent of this problem is unknown. Apparently, it occurs only in a small number of RLS patients treated with drugs called dopamine agonists. Considering this potential side effect of dopamine agonists, the Mayo Clinic authors suggest that physicians screen all RLS patients for compulsive behaviors while taking a thorough medical history prior to prescribing dopamine agonists. Patients should be monitored closely for signs of compulsive behaviors once dopamine agonist treatment has begun. The report suggests that the compulsion to gamble worsened with increasing doses of the dopamine agonists.
Current Report Builds on Earlier FindingsPathological gambling is an impulse control disorder. In 2005, Mayo Clinic physicians reported this disorder as a side effect of dopamine agonist therapy in 11 Parkinson disease patients. "Although pathologic gambling has already been recognized in patients with Parkinson disease who often took high doses of dopamine agonists, the current report suggests that pathological gambling is not restricted to patients with Parkinson disease -- and also can occur at low dosages" explains Maja Tippmann-Peikert, M.D., the lead author of the Mayo Clinic report on restless legs syndrome. "Physicians should not only monitor Parkinson disease patients for this behavior but also screen their RLS patients who may be on much lower doses of dopamine agonists." This includes encouraging the patient, family members and friends to report negative behaviors to the patient's physician.........
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February 7, 2007, 9:38 PM CT
Risk of extinction accelerated due to human
Change in Marine Environments
The simultaneous effect of habitat fragmentation, overexploitation, and climate warming could accelerate the decline of populations and substantially increase their risk of extinction, a study published in the Proceedings of the Royal Society B has warned.
Using experimental microcosm populations of rotifers (a type of zooplankton), the study found that individually each of these threats caused significant population declines. The study also found that the rate of declines was much accelerated when populations were exposed to more than one threat. These results indicate that multiple interacting threats are capable of causing rapid population extinction, and that all threats should be simultaneously reduced, if their synergies are to be avoided and if the current rate of species loss is to be reversed.
Many scientific efforts have been made to link the decline of wild marine and terrestrial populations with human activities such as habitat fragmentation, overexploitation and global warming. "Establishing the link between the loss of biodiversity and human-related threats is crucial to develop policies aimed at mitigating such threats", says Camilo Mora at Dalhousie University, leading author of the paper. "Unfortunately, in many cases several threats are operating simultaneously making it difficult to isolate their individual and combined effects through field observations,"Mora adds.........
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February 7, 2007, 9:35 PM CT
Horse genome assembled
The first draft of the horse genome sequence has been deposited in public databases and is freely available for use by biomedical and veterinary researchers around the globe, leaders of the international Horse Genome Sequencing Project announced today.
The $15 million effort to sequence the approximately 2.7 billion DNA base pairs in the genome of the horse (Equus caballus) was funded by the National Human Genome Research Institute (NHGRI), one of the National Institutes of Health (NIH). A team led by Kerstin Lindblad-Toh, Ph.D., at the Eli and Edythe L. Broad Institute of the Massachusetts Institute of Technology and Harvard University, in Cambridge, Mass., carried out the sequencing and assembly of the horse genome.
Approximately 300,000 Bacterial Artificial Chromosome (BAC) end sequences, which provide continuity when assembling a large genome sequence, were contributed to the horse sequencing project by Ottmar Distl, D.V.M., Ph.D. and Tosso Leeb, Ph.D., from the University of Veterinary Medicine, in Hanover, Germany and Helmut Blöcker, Ph.D., from the Helmholtz Centre for Infection Research in Braunschweig, Germany. Production of the BAC end sequences was funded by the Volkswagen Foundation and the State of Lower Saxony.
Sequencing of the domestic horse genome began in 2006, building upon a 10-year collaborative effort among an international group of scientists to use genomics to address important health issues for equines, known as the Horse Genome Project (www.uky.edu/Ag/Horsemap/). The horse whose DNA was used in the sequencing effort is a Thoroughbred mare named Twilight from Cornell University in Ithaca, N.Y. Researchers obtained the DNA from a small sample of the animal's blood. To download a high-resolution photo of Twilight, go to http://www.genome.gov/pressDisplay.cfm?photoID=20008. Twilight is stabled at the McConville Barn, Baker Institute for Animal Health, College of Veterinary Medicine, at Cornell University, with a small herd of horses that have been selected and bred for more than 25 years to study the mechanisms that prevent maternal immunological recognition and destruction of the developing fetus during mammalian pregnancy. The research, conducted by Cornell professor Doug Antczak, V.M.D, Ph.D., and funded by the National Institute of Child Health and Human Development, has implications in reproduction, clinical organ transplantation and immune regulation. ........
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February 7, 2007, 9:13 PM CT
Better Control Of Hemorrhagic Fever Viruses
Researchers report discovering the receptor through which a group of life-threatening hemorrhagic fever viruses enter and attack the body's cells, and show that infection can be inhibited by blocking this receptor. The findings, to be published online by the journal Nature on February 7, give a clue to the high lethality of New World arenaviruses, suggest a way of reducing the severity of infection, and point the way toward a sorely needed treatment strategy.
The four viruses, known as the Machupo, Guanarito, Junin and Sabia viruses, cause Bolivian, Venezuelan, Argentine and Brazilian hemorrhagic fever, respectively, with mortality rates of about 30 percent. No vaccine is available, though a weakened form of Junin virus has been given to Argentinean farmers with some success. In addition to causing occasional disease outbreaks, mostly in poor, rural areas of South America, the viruses are of U.S. government interest because of their potential as bioterrorism agents. All four are classified as NIAID Category A Priority Pathogens and must be handled in Biosafety Level 4 containment facilities.
The researchers, led by Hyeryun Choe, PhD, of Children's Hospital Boston's Pulmonary Division, and Michael Farzan, PhD, of Harvard Medical School (HMS), first investigated the Machupo virus. To identify its cellular receptor, they made copies of the "spike" protein, used by the virus to gain entry into cells, and added it to cells from African green monkeys, known to be highly susceptible to Machupo virus infection. Later, they broke the cells open and isolated the spike protein and the cellular protein to which it had attached itself. Then, using a technique called mass spectrometry, they analyzed this attached cellular protein to determine its identity.........
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February 7, 2007, 9:09 PM CT
Adaptation to global climate change
Temperatures are rising on Earth, which is heating up the debate over global warming and the future of our planet, but what may be needed most to combat global warming is a greater focus on adapting to our changing planet, says a team of science policy experts writing in this week's Nature magazine.
While many consider it taboo, adaptation to global climate change needs to be recognized as just as important as "mitigation," or cutting back, of greenhouse gases humans pump into Earth's atmosphere. The science policy experts, writing in the Feb. 8, 2007 issue of Nature, say adapting to the changing climate by building resilient societies and fostering sustainable development would go further in securing a future for humans on a warming planet than just cutting gas emissions.
"New ways of thinking about, talking about and acting on climate change are necessary if a changing society is to adapt to a changing climate," the researchers state in "Lifting the Taboo on Adaptation".
The policy experts include Daniel Sarewitz, director of Arizona State University's Consortium for Science, Policy & Outcomes; Roger Pielke Jr., University of Colorado, Boulder; Gwyn Prins, London School of Economics, London, England, and Columbia University, New York; and Steve Rayner of the James Martin Institute at Oxford University, Oxford, England.........
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February 7, 2007, 9:06 PM CT
usual view of elusive force
JILA scientists measured how temperature affects the Casimir-Polder force using an apparatus that holds four small squares of glass inside a vacuum chamber.
Credit: E. Cornell group/JIL
Physicists at JILA have demonstrated that the warmer a surface is, the stronger its subtle ability to attract nearby atoms, a finding that could affect the design of devices that rely on small-scale interactions, such as atom chips, nanomachines, and microelectromechanical systems (MEMS).
The research highlights an underappreciated aspect of the elusive Casimir-Polder force, one of the stranger effects of quantum mechanics. The force arises from the ever-present random fluctuation of microscopic electric fields in empty space. The fluctuations get stronger near a surface, and an isolated neutral atom nearby will feel them as a subtle pulla flimsy, invisible rubber band between bulk objects and atoms that may be a source of friction, for example, in tiny devices. The JILA group previously made the most precise measurement ever of Casimir-Polder, measuring forces hundreds of times weaker than ever before and at greater distances (more than 5 micrometers). JILA is a joint institute of the National Institute of Standards and Technology (NIST) and the University of Colorado at Boulder.
Now, as reported in a paper scheduled for this week's issue of Physical Review Letters, the JILA team has made the first measurement of the temperature dependence of this force. By using a combination of temperatures at opposite extremesmaking a glass surface very hot while keeping the environment neutral and using ultracold atoms as a measurement toolthe new research underscores the power of surfaces to influence the Casimir-Polder force. That is, electric fields within the glass mostly reflect inside the surface but also leak out a little bit to greatly strengthen the fluctuations in neighboring space. As a result, says group leader and NIST Fellow Eric Cornell, "warm glass is stickier than cold glass".........
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February 5, 2007, 7:29 PM CT
Human Activity Fuels Global Warming
Today's release of a widely anticipated international report on global warming coincides with a growing clamor within the United States to reduce greenhouse gas emissions and prevent the potentially devastating consequences of global climate change.
"There's more interest in this now than at any time in the last 20 years," says Ronald Prinn, TEPCO Professor of Atmospheric Sciences at MIT, who was a lead author of the report issued by the Intergovernmental Panel on Climate Change (IPCC).
The report issued today in Paris, a 21-page summary of a much longer study on the science behind climate change, concludes there is a greater than 90 percent chance that greenhouse gases from human activity are responsible for most of the steadily rising average global temperatures observed in the past 50 years.
"There's clear evidence that greenhouse gases have been increasing by very large amounts since preindustrial times, and the vast majority of these increases are due to human activity," said Prinn, whose specific task on the panel was to assess this issue.
This is the fourth climate report issued by the IPCC since it was established by the U.N. in 1988. Prinn, who is the director of MIT's Center for Global Change Science, was one of more than 100 lead authors for the three-year study, which involved climate scientists from around the world.........
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February 5, 2007, 6:31 PM CT
Volcanism with Under-Ocean Sensors
Earthquakes and volcanic activity occur when the tectonic plates that make up Earth's surface move apart or converge. While this activity is relatively easy to observe on land, it's more difficult to observe under the ocean, where most of it occurs. A University of Missouri-Columbia researcher will soon undertake a study to learn more about this process by placing sensors on a mid-ocean ridge called the East Pacific Rise.
"Right now, we can only listen from land using seismometers, or in the oceans using hydrophones, and try to find out when there is activity in a mid-ocean ridge," said Marie-Helene Cormier, assistant professor of geological sciences in MU¿s College of Arts and Science. "We might not know for a few days, and then it might take at least a week to get a ship to the site. If we want to study what's happening, it's very difficult to get accurate and timely information. Our goal is to put sensors in place so that we can record activity as it is happening. When we recover our sensors, we'll be able to study what was happening during those moments."
In mid February, Cormier and her colleagues, Spahr Webb and Roger Buck of Columbia University, will place sensors on the seafloor in multiple positions along the East Pacific Rise southwest of Mexico. The sensors will measure and record changes in the pressure of the water column above them. Cormier said the pressure of the water is expected to decrease during ridge activity because magma flows up between the two plates, creating new seafloor and raising the height of the sensors by a few inches. She and her team will collect data from the sensors while they are in place until they are removed from the ocean floor in 2009 or 2010. MU undergraduate students are expected to accompany Cormier on the research mission to learn more about geology and marine research.........
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January 31, 2007, 8:42 PM CT
Oral Wounds Heal Slower In Women
Wounds in the mouth heal more slowly in women and older adults, a new study at the University of Illinois at Chicago reveals.
"While wounds to the skin heal more quickly in women than in men, our study suggested the opposite is true for healing of wounds inside the mouth," said Dr. Phillip Marucha, head of periodontics at the UIC College of Dentistry.
"We discovered that, regardless of age, men's mouth wounds heal faster than women's".
Older women were at the highest risk for delayed healing, their wounds closing half as slowly as younger men, Marucha said. The findings of the study, he said, could have important implications for surgical practices.
"There are an increasing number of surgical procedures being performed in older populations," Marucha said. "A greater emphasis needs to be placed on accelerating the healing process. Discovering the reasons behind these age and sex differences will help us improve treatment, and postsurgical recovery times may be reduced".
The study consisted of creating a small, standardized circular wound, half the diameter of a pencil, between the first and second molar of 212 male and female volunteers aged 18 to 35 years and 50 to 88 years. The wounds were videographed at the same time for seven consecutive days to assess closure.........
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January 30, 2007, 9:22 PM CT
What Causes Highly Dynamic Aurora
On a clear night over the far northern areas of the world, you may witness a hauntingly beautiful light display in the sky that can disrupt your satellite TV and leave you in the dark.
The eerie glow of the northern lights seems exquisite and quite harmless. Most times, it is harmless. The display, resembling a slow-moving ribbon silently undulating in the sky, is called the aurora. It is also visible in far southern regions around the South Pole.
Occasionally, however, the aurora becomes much more dynamic. The single auroral ribbon may split into several ribbons or even break into clusters that race north and south. This dynamic light show in the polar skies is linked to what researchers call a magnetospheric substorm. Substorms are very closely correlation to full-blown space storms that can disable spacecraft, radio communication, GPS navigation, and power systems while supplying killer electrons to the radiation belts surrounding Earth. The purpose of NASA's Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission is to understand the physical instability (trigger mechanism) for magnetospheric substorms.
A clash of forces we can't see with the human eye causes the beauty and destruction of space storms, though the aurora provides a dramatic symptom. Earth's molten iron core generates an invisible magnetic field that surrounds our planet. This magnetic field and the electrically charged matter under its control compose the Earth's magnetosphere.........
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