March 5, 2007, 8:44 PM CT

Atlantic Ocean Warming and Stronger Hurricanes

Atmospheric researchers have uncovered fresh evidence to support the theory that global warming has contributed to the emergence of stronger hurricanes in the Atlantic Ocean. But the trend doesn't hold up in the world's other oceans.

Researchers funded by the National Science Foundation (NSF) and affiliated with the University of Wisconsin-Madison and NOAA's National Climatic Data Center (NCDC) in Asheville, N.C., reported the findings in the journal Geophysical Research Letters. The work should help clarify two studies last year that drew connections between global warming and increasingly intense hurricanes.

"Documenting trends in hurricane intensity is made more difficult by sparse observations and has led to debates about whether the trends are real, or are artifacts of observations," says Jay Fein, program director in NSF's division of atmospheric sciences. "This study has directly addressed this point by using, for the first time, a new satellite data set to look at hurricane trends".

For decades, hurricane scientists found it difficult to work with the inconsistent nature of hurricane data. Before the advent of weather satellites, researchers were forced to rely on scattered ship reports and sailor logs to stay abreast of storm conditions. The advent of weather satellites during the 1960s dramatically improved the situation, but the technology has changed so rapidly that newer satellite records are barely consistent with older ones......... Posted by: Tyler      Read more         Source

March 5, 2007, 4:59 PM CT

Life Can Be a Strain

Powered by mere vibrations or the movement of magnets, novel sensors and transmitters developed by a small company in Vermont are changing the way engineers are looking at fatigue.

Communicating wirelessly via the Internet to engineers halfway across the world, the embedded sensors developed by MicroStrain--a small business based in Williston, Vt., and supported by the National Science Foundation (NSF)--are revealing how objects as diverse as the Liberty Bell, enormous mining trucks and even human knees respond to daily use.

By monitoring strain levels and tracking the cumulative effects of fatigue, the researchers' ultimate goal is to supplant the nearly universal system of "replace by this date" with a smarter approach of replacing components based upon the actual operating loads components experience.

"By calculating the amount of fatigue that a component has been exposed to, it is possible to repair or replace the component only when required," said engineer Steve Arms, president of MicroStrain. "Properly implemented, this can significantly reduce costs".

MicroStrain has received several NSF Small Business Innovation Research Program awards to support the development of cutting-edge sensors and compatible wireless transmitters that can carry their information to monitors around the globe......... Posted by: Kevin      Read more         Source

March 5, 2007, 4:15 PM CT

Designer Molecule to Clean Up Fluorocarbons

The chemical bond between carbon and fluorine is one of the strongest in nature, and has been both a blessing and a curse in the complex history of fluorocarbons. Now, in a powerful demonstration of the relatively new field of "computational chemistry," scientists at the National Institute of Standards and Technology (NIST) and the Interdisciplinary Network of Emerging Science and Technology group (INEST, sponsored by Philip Morris USA) have designed-in a computer-a wholly theoretical molecule to pull the fluorine out of fluorocarbons.*.

At sea level, the strong C-F bond makes fluorocarbons thermally and chemically stable. As a result, fluorocarbons have been used in a number of commercial applications including refrigerants, pesticides and non-stick coatings. In the upper atmosphere, however, high-energy photons and highly reactive ozone molecules can break apart fluorocarbons, with the well-known consequence of a depleted ozone layer and increased ultraviolet radiation at ground level. A determined chemist can break down fluorocarbons at ground level with certain organometallic compounds, but the reactions take a long time at very high temperatures. Other known reagents are both highly toxic and inefficient, so chemists have been searching for an economical and environmentally friendly method to dispose of fluorocarbons......... Posted by: Sarah      Read more         Source

March 5, 2007, 4:07 PM CT

Measuring Cell Mechanical Properties

Scientists at the National Institute of Standards and Technology (NIST) have developed a microelectromechanical system (MEMS) cell-stretcher that can measure the mechanical properties of a living cell, such as its ability to stick to a surface. The new device is expected to enable novel studies of cell mechanics, which influence basic cell functions such as growth and division, and diseases such as sickle cell anemia and asthma.

The prototype device, described in a new paper,* is thought to bethe only technique for studying bulk mechanical properties of a single, whole cell while it is spreading out and sticking to a substrate as it would in the body, says the designer, NIST bioengineer David Serrell. Other biomechanical test methods focus on individual cell components or entire tissues.

The heart of the NIST device is a circular cell platform 200 micrometers wide, a tiny fleck just barely visible to the naked eye. The two halves of the circle can be pulled as far as 100 micrometers apart under computer control, while the force needed to separate them is measured by sensors. In a demonstration using a connective tissue cell, the cell is placed on the center of the platform, allowed to spread and adhere for several hours, and then pulled slowly apart until it detaches. In NIST experiments, the cells let go of the substrate at a force of about 1500 nanonewtons. (One nanonewton is the approximate amount of force mandatory to break a single chemical bond between two atoms.)......... Posted by: Kevin      Read more         Source

March 2, 2007, 5:02 AM CT

Heatwave on the top of the world

The French Intergovernmental Panel on Climate Change (IPPC, or GIEC in French) has just announced the conclusions of its 4th report, which restates that global warming has increased the average temperature by 0.74C over the last century. However, there is very little information about some parts of the planet, such as central Asia. A new study by French scientists from the Laboratory of Glaciology and Geophysics of the Environment (LGGE, CNRS / Universit Joseph Fourier, Grenoble, France) and the Laboratory of Sciences of the Cliamte and the Environment (LSCE / IPSL, CEA / CNRS / Universit de Versailles Saint-Quentin, France), in collaboration with Chinese, Russian and American researchers, proves that the recent warming has also affected the ice cap on Mount Everest, in the heart of the Himalayas. This result was published on February 7, 2007 in the European Journal "Climate of the Past".

Relatively little is known about climate change in the Himalayas and the Tibetan plateau. There are very few meteorological stations, and instrumental records from glaciers, lakes or tree growth rings are rare and difficult to interpret. However, in 2001 and 2002, Chinese researchers drilled three ice cores in the eastern summit of the East Rongbuk glacier that covers the north pass of Mount Everest, at 6518 meters above sea level. These ice cores were analyzed in collaboration with the LGGE and the LSCE, and they have shown that a new climate marker exists, the ice core gas content, which can reconstruct the changes in summer temperatures on this very high site......... Posted by: Tyler      Read more         Source

March 2, 2007, 5:00 AM CT

Rethinking Strategies For Soot Emission

Carnegie Mellon University scientists say government officials need to adopt new ways of measuring and regulating the fine particles of smoke and soot so endemic to serious health problems and the global warming crisis.

In a March 2 article reported in the journal Science, professors Allen L. Robinson and Neil M. Donahue report a new conceptual model for how microscopic particles behave in the atmosphere that raises new questions about current regulations.

The research found new chemical processes that occur after soot and gaseous pollutants are emitted from cars and trucks, changing the chemical and physical properties of the soot particles and creating new particulate matter. These new particles are potentially more toxic and may have a stronger influence on cloud formation that can alter the global climate.

"One of our key findings is that this chemical processing leads to more particulate matter in the air, meaning that regulators are likely underestimating how sources such as cars and trucks contribute to pollution," said Robinson, an associate professor of mechanical engineering and engineering and public policy. "We need to take a holistic approach to regulating these sources that account for all emissions." Accounting for these new processes improves the predictions of the models federal and state governments use to develop regulations......... Posted by: Tyler      Read more         Source

March 1, 2007, 9:51 PM CT

Insights Into Osteosarcoma In Cats And Dogs

Researchers at the University of Illinois have found that a molecular pathway known to have a role in the progression of bone cancer in humans is also critical to the pathology of skeletal tumors in dogs and cats. Their work could lead to advances in the palliative care of companion animals afflicted with osteosarcoma.

The research team, which included U. of I. pathobiology professor Anne Barger, examined the homeostatic role of an enzyme, receptor activator of nuclear factor kappa-B (known as RANK), and two key modulators of its activity: RANK ligand (RANK-L) and osteoprotegrin (OPG). RANK is one of a family of receptors that regulates bone and immune homeostasis. In health, RANK, RANK-L and OPG together keep the continual process of bone growth and resorption in balance.

Bone tumors presumably derail this homeostatic process, however, by upregulating RANK-L expression. RANK-L binds to RANK, stimulating the production and activation of osteoclasts (bone cells that increase the breakdown of bone tissue).

OPG counter-regulates RANK-L by blocking its ability to bind to RANK.

Eventual therapeutic interventions may make use of OPG or other RANK-L inhibitors to slow the process of bone destruction in skeletal tumors in cats and dogs, Barger said. Although not a cure, this could reduce the pain and other complications associated with bone cancer. Such therapies have proven effective at reducing pathologic bone loss in human bone cancer patients......... Posted by: Sean      Read more         Source

March 1, 2007, 4:40 AM CT

Adolescent Dieting May Predict Weight Gain

Adolescents who go on diets to lose weight may be significantly increasing their odds of gaining weight, say researchers at the University of Minnesota.

The researchers studied results of Project EAT (Eating Among Teens) surveys, conducted in 1999 and 2000, and results of Project EAT II surveys, conducted in 2003 and 2004, to "understand the perplexing finding, that has been reported in several longitudinal studies, whereby dieting predicts greater weight gain over time in adolescents".

According to information provided by more than 2,500 adolescents, dieting predicted increased binge eating and decreased breakfast consumption among girls, "with a nonsignificant trend toward decreased fruit and vegetable intake." Among boys, dieting predicted "increased binge eating, decreased physical activity and a trend toward decreased breakfast consumption. These behaviors were also associated with increases in body mass index," according to the researchers.

The researchers conclude that dieting may lead to weight gain among adolescents in part "via the long-term adoption of behavioral patterns that are counterproductive to weight management"......... Posted by: Sean      Read more         Source

February 28, 2007, 9:51 PM CT

Through Precariously Balanced Rocks

A seismological research team from the University of Nevada, Reno is finding ways to make precariously balanced rocks talk. In so doing, they are unlocking valuable scientific information in assessing seismic hazards in areas throughout the West.

Their findings are shared in the January-recent issue of American Scientist magazine. Researchers think that zones of precarious rocks rocks that have come close but haven't tipped over in the wake of a major seismic event provide important information about seismic risk, its magnitude and its frequency.

"There's really no long-term data to test seismic hazards other than precarious rocks," said Matthew Purvance, a postdoctoral scholar in geophysics at the University, who authored the article along with James Brune, professor in the Department of Geological Sciences and past director of the Nevada Seismological Laboratory, and Rasool Anooshehpoor, research professor in the Nevada Seismological Laboratory.

"By studying precariously balanced rocks, it can serve as an indicator that an earthquake of a sufficient size to topple a tippy rock has not occurred at least for a very long time. We think this is a fundamental story that gives fundamental information on seismic hazards that has never been done before"......... Posted by: Tyler      Read more         Source

February 28, 2007, 9:49 PM CT

Through Precariously Balance Rocks

A seismological research team from the University of Nevada, Reno is finding ways to make precariously balanced rocks talk. In so doing, they are unlocking valuable scientific information in assessing seismic hazards in areas throughout the West.

Their findings are shared in the January-recent issue of American Scientist magazine. Researchers think that zones of precarious rocks rocks that have come close but haven't tipped over in the wake of a major seismic event provide important information about seismic risk, its magnitude and its frequency.

"There's really no long-term data to test seismic hazards other than precarious rocks," said Matthew Purvance, a postdoctoral scholar in geophysics at the University, who authored the article along with James Brune, professor in the Department of Geological Sciences and past director of the Nevada Seismological Laboratory, and Rasool Anooshehpoor, research professor in the Nevada Seismological Laboratory.

"By studying precariously balanced rocks, it can serve as an indicator that an earthquake of a sufficient size to topple a tippy rock has not occurred at least for a very long time. We think this is a fundamental story that gives fundamental information on seismic hazards that has never been done before"......... Posted by: Tyler      Read more         Source