December 27, 2006, 4:54 AM CT

Links Between African And U.S. Weather Systems

When their DC-8 flew into a tropical storm off the coast of West Africa, Aaron Pratt and Tamara Battle realized their lifelong dream--to study storms and weather systems at their source. During that flight, lightning struck their plane. The resulting storm turned into a tropical depression and ultimately became known as Hurricane Helene, one of the strongest Atlantic hurricanes in 2006.

Pratt and Battle were thrilled. They, along with Stephen Chan, Amber Reynolds, Daniel Robertson and Deanne Grant, spent a month conducting weather research in Senegal and Cape Verde, West Africa. The students worked with researchers from universities and government agencies to study how land storms become ocean storms and then make their way west to U.S. and Caribbean waters.

"African dust is very critical for hurricane formation. One of our flights allowed us to see the dust kicked up in the Sahara Desert," said Pratt, who is pursuing a doctorate in atmospheric science from Howard University in Washington, D.C. "I had never done research overseas before and didn't know what to expect. Working with researchers in both Senegal and Cape Verde helped put our research in the proper perspective".

Battle is also a doctoral candidate in atmospheric science at Howard University. "When we flew over the Sahara Desert, it was serene and beautifully simple," she said. "Africa's easterly waves and Saharan dust storms not only impact the weather in the United States and the Caribbean, but they also have implications for the inhabitants of a number of African countries. By sharing what we've learned, we increase the chances of helping those countries improve forecasting and predictability. That will have a positive impact on the agriculture and economy of the region".........

Posted by: Tyler      Read more         Source

December 26, 2006, 8:05 PM CT

Stem Cells As Cancer Therapy

It is widely hoped that neural stem cells will eventually be useful for replacing nerves damaged by degenerative diseases like Alzheimer disease and multiple sclerosis. But there may also be another use for such stem cells--delivering anti-cancer drugs to cancer cells.

A Perspective article in PLoS Medic ine, by Professor Riccardo Fodde (Erasmus Medical Center, The Netherlands), discusses a new study in mice, reported in the launch issue of PLoS ONE (www.plosone.org), that showed that neural stem cells could be used to help deliver anti-cancer drugs to metastatic cancer cells.

One of the characteristics of neural stem cells is their tendency to move towards diseased areas (researchers call this phenomenon "pathotropism"). This characteristic, says Professor Fodde, "makes them especially attractive candidates not only to replace damaged tissue in degenerative pathologies, but also to deliver therapeutic molecules in patients with disseminated metastatic cancer".

In the study published in PLoS ONE, Karen Aboody and his colleagues report on the eradication of disseminated metastases in a mouse model of a cancer called neuroblastoma. The scientists took advantage of the tumor-tropic (selective migration towards cance r cells) properties of neural stem cells engineered to express an enzyme that activates an anti-cancer drug.........

Posted by: Sean      Read more         Source

December 26, 2006, 7:32 PM CT

Pet Owners Are Sick More Often

A common perception is that pet owner is a young person who is full of action, exercises a lot, and actively plays with a pet, particularly with a dog. The reality is different, however.

The association of pet ownership and health of working aged Finns (20-54 years of age) was studied at the University of Turku as part of a large research project entitled Health and Social Support (HeSSup). The findings were published in PLoS ONE, the new international online publication of the Public Library of Science.

At the total population level, pet ownership was most common among those 40 years of age or older, those whose lives are established and who are settled down as well as among those who live in single family houses and who have couple relationships. Pet ownership was slightly more often associated with a low rather than high social standing or education. Four of five people working in agriculture had a pet, with 41% of those representing other occupational groups having one.

Pet owners are part of the population group that based on their age or low socio-economic standing has plenty of different kinds of illness or disease related risk factors, including a greater Body Mass Index (BMI) than the rest. In this study, they smoked slightly more often and exercised less often than those not having pets. Dog owners did exercise more than those not having a dog, but it did not have an effect on the BMI. Pet owners in general had hobbies associated with hunting or moving about in nature more often than the rest.........

Posted by: Sean      Read more         Source

December 26, 2006, 6:12 PM CT

Western Wildfires And Atlantic Ocean Surface Temperatures

Western U.S. wildfires are likely to increase in the coming decades, as per a new tree-ring study led by the University of Comahue in Argentina and involving the University of Colorado at Boulder that links episodic fire outbreaks in the past five centuries with periods of warming sea surface temperatures in the North Atlantic.

States like Washington, Oregon, California, Colorado, New Mexico, Arizona and South Dakota all had an increased prevalence of wildfires in recent centuries when a phenomenon known as the Atlantic Multi-Decadal Oscillation -- similar but longer in duration than the better known El Nino-Southern Oscillation -- periodically shifted from a cool to a warm mode that lasted roughly 60 years each time, said the study authors.

Warmer waters in the North Atlantic correspond with episodes of drought and subsequent fires in the West as shown by fire scars in annual tree rings studied by the researchers, said Thomas Kitzberger of the University of Comahue, who led the study with scientists from CU-Boulder, the University of Arizona, the U.S. Forest Service and Rocky Mountain Tree-Ring Research Inc., a private lab in Fort Collins, Colo.

Kitzberger, who received his doctorate from CU-Boulder in 1994 under co-author and CU-Boulder geography Professor Thomas Veblen, said the North Atlantic warming trend, coupled with warming temperatures and the earlier onset of spring in the West, poses "an increased hazard for wildfires that may continue for decades." The paper was published the week of Dec. 25 in the Proceedings of the National Academy of Sciences.........

Posted by: Tyler      Read more         Source

December 26, 2006, 6:06 PM CT

Biggest Fish Catch In 24 Years

Five tons of marbled Antarctic cod (Notothenia rossii), now that was surely a big surprise to researchers and crew on board of Polarstern, alike considering that prior and subsequent hauls barely ever reaped such plentiful harvests.

Their shimmering silver and dark blue bodies, which can grow up to 70 cm, were piled on the aft deck of the research vessel maintained by the Alfred Wegener Institute for Polar and Marine Research.

In combination with prior stock assessments, fisheries biologists onboard interpreted the catch as a sampling of a discrete, small-scale aggregation of this fish species.

There are two hypotheses to explain the observed dense aggregation: 1. krill, the main prey of marbled Antarctic cod, aggregate to form a band of dense shoals in close vicinity to its preferred habitat; and 2. certain seafloor topographies, such as canyons or cliffs may be conducive to its aggregation. The tendency to shoal made them an easy target for commercial fisheries in the past. After depletion of marbled Antarctic cod stocks the "Convention on the Conservation of Antarctic Marine Living Resources" (CCAMLR) decided to ban fishing activities. Resuming commercial fisheries could easily lead to stocks being overfished. Gera number of, represented by the Federal Research Centre for Fisheries, is constantly providing results to the responsible CCAMLR working group to prevent overexploitation of Antarctica's fish stocks.........

Posted by: Ashley      Read more         Source

December 25, 2006, 4:34 PM CT

New Possibilities For Magnetic Storage

For about ten years now, tiny magnetic structures measuring a few millionths of a millimetre have met with growing interest from the worlds of science and technology, especially on account of their potential applications in magnetic storage. A fascinating quantum mechanical phenomenon occurs in these structures: the vortex core, which has been predicted in theory for forty years, but which experiments revealed only four years ago. In small magnetic plates, the magnetised areas often come together to form level closed magnetic circuits - these are the vortices. Imagine walking with an atom-sized compass in a vortex. The compass needle would always be level, unless you approached its centre, the vortex. There the atomic magnetic compass needles rise from the surface and a magnetic field is created over a tiny radius of around 20 atoms, the largest possible in the material.

The magnetic needles can point either up or down in the vortex core (fig. 1). However, if this property is to be used for magnetic storage, a way must be found to combat the enormous stability typical of vortex structures. Up to now, very high external magnetic fields of around half a Tesla were mandatory to reverse the vortex core. That is approximately one third of the field that the strongest permanent magnet is capable of delivering.........

Posted by: Kevin      Read more         Source

December 25, 2006, 4:28 PM CT

Ocean Temperature And Marine Species

Ocean temperature apparently has a great effect on the spread of marine species. I was reading the following article this morning, and thought about writing this article in this column.

Researchers can predict how the distance marine larvae travel varies with ocean temperature - a key component in conservation and management of fish, shellfish and other marine species - as per a new study from the University of North Carolina at Chapel Hill.

Most marine life, including commercially important species, reproduces via larvae that drift far along ocean currents before returning to join adult populations. The distance larvae travel before maturing, called dispersal, is directly associated with ocean temperature, the scientists found. For example, larvae from the same species travel far less in warmer waters than in colder waters, said lead author Mary O'Connor, a graduate student in marine ecology in UNC's curriculum in ecology and the department of marine sciences in the College of Arts and Sciences.

"Temperature can alter the number and diversity of adult species in a certain area by changing where larvae end up," O'Connor said. "It is important to understand how a fish population is replenished if we want to attempt to manage or conserve it".

Using data from 72 marine species, including cod, herring, American lobster, horseshoe crabs and clams, O'Connor and her colleagues developed a model that predicts how far larvae travel at a certain temperature. The predictions appear to hold for virtually all marine animals with a larval life cycle.........

Posted by: Tyler      Read more         Source

December 23, 2006, 11:04 AM CT

Two Different Crystalline Forms Of Aspirin

I am sure that you don't think of the crystalline structure of aspirin, when you have a headache and reach out for the aspirin bottle. At least that's what I do. This aspirin pill might relieve your headache, but the same aspirin is causing lots of headaches for some researchers.

The question that is causing problem for scientists is: is there another form on top of the long-known one? A team of scientists from Denmark, Germany, and India seems to have solved this controversial puzzle: yes, there is a second structure-but it does not exist as a pure form. "The two crystalline forms of aspirin are so closely related," explains the research team of Andrew D. Bond, Roland Boese and Gautam R. Desiraju in Angewandte Chemie, "that they form structures containing domains of both crystal types".

In 2004, computer calculations had indicated that while the long-known crystal structure of aspirin (form I) is definitely one of the most stable forms, another version might exist that is just as stable, though it had not yet been discovered-a clear challenge to researchers in the field. The difference between the proposed structures is slight: both have identical layers containing molecules grouped into pairs, but these layers are arranged differently in the two different structures. In 2005, researchers in the USA announced the discovery of the predicted structure (form II). But was this merely an artifact?........

Posted by: Sarah      Read more         Source

December 22, 2006, 5:18 AM CT

Strange Properties Of Superfluids

Princeton University electrical engineers are using lasers to shed light on the behavior of superfluids -- strange, frictionless liquids that are difficult to create and study. Their technique allows them to simulate experiments that are difficult or impossible to conduct with superfluids.

The odd behavior of particles in superfluids, which move together instead of at random, has been observed in light waves that pass through certain materials known as nonlinear crystals. The team relied on this underappreciated correlation to use laser light as a substitute, or model, for superfluids in experiments. Their results would be published in the January 2007 issue of Nature Physics.

Their work could heighten the current understanding of condensed matter physics as well as lead to advances in sensor technology, atomic trapping and optical communications.

"Once you realize you can use light to model a superfluid, a new world opens up," said Jason Fleischer, a Princeton assistant professor of electrical engineering who led the team. "An entire field of physics is interested in studying the dynamics of superfluids, but the experiments are difficult to do. It's a lot easier to conduct the experiments with lasers".

Fleischer and Princeton Engineering graduate students Wenjie Wan and Shu Jia validated their technique by generating results that matched data from previous superfluid experiments. They went on to study superfluid waves and interactions that had not been considered before, either theoretically or experimentally. For instance, they explored the collisions of circular waves similar to those created by drops of water falling into a puddle.........

Posted by: Kevin      Permalink         Source

December 20, 2006, 7:09 PM CT

Abnormal Proteins Linked To Schizophrenia

A new study suggests biochemical changes linked to schizophrenia aren't limited to the central nervous system and that the disease could have more encompassing effects throughout the body than previously thought. The findings, scheduled for publication in the January 2007 issue of the American Chemical Society's Journal of Proteome Research, could lead to better diagnostic testing for the disease and could help explain why those afflicted with it are more prone to type II diabetes, cardiovascular diseases and other chronic health problems.

Researcher Sabine Bahn, M.D., Ph.D., and her colleagues at Cambridge University in England and the University of Cologne in Gera number of, detected abnormal proteins associated with schizophrenia in the liver and red blood cells of people who have the disorder. It is the first time the same altered proteins have been detected both within brain tissue as well as in non-brain tissue, as per Bahn.

In time, Bahn says, these protein "biomarkers" could be used to trace the progression of the disease throughout the body.

"If changes in the rest of the body can be observed, and if these changes reflect what is going wrong in the brain, we can use these (findings) to learn about the cellular dysfunction that causes schizophrenia and this will allow us to develop better drugs and diagnostics," Bahn says.........

Posted by: Sean      Permalink         Source