March 20, 2007, 10:16 PM CT

Prehistoric Hurricane Activity

Hurricanes Katrina and Rita focused the international spotlight on the vulnerability of the U.S. coastline. Fears that a "super-hurricane" could make a direct hit on a major city and cause even more staggering losses of life, land and economy triggered an outpouring of studies directed at every facet of this ferocious weather phenomenon. Now, an LSU professor takes us one step closer to predicting the future by drilling holes into the past.

Kam-biu Liu, George William Barineau III Professor in LSU's Department of Oceanography and Coastal Sciences, is the pioneer of a relatively new field of study called paleotempestology, or the study of prehistoric hurricanes. Liu, a long-time resident of Louisiana, became even more interested in the subject during the aftermath of Hurricane Katrina, when a national debate was sparked concerning hurricane intensity patterns and cycles.

"People were discussing the probability of a Category 5 hurricane making direct impact on New Orleans," said Liu. "That's tricky, because it's never actually happened in history. Even Katrina, though still extremely powerful, was only a Category 3 storm at landfall."

Currently, experts tend to agree that Atlantic hurricane activity fluctuates in cycles of approximately 20-30 years, alternating periods of high activity with periods of relative calm. But records of such events have only been kept for the last 150 years or so. What would happen, Liu wondered, if you looked back thousands of years? Would larger cycles present themselves?......... Posted by: Tyler      Read more         Source

March 20, 2007, 10:15 PM CT

Dental Visits Determinants Of Underserved

Children's dental insurance and caregivers' preventive dental care visits play a significant role as determinants of underserved African-American children seeing a dentist, according to a study in this month's Journal of the American Dental Association (JADA).

The objective of the study, according to University of Michigan (Ann Arbor) researchers, was to investigate determinants of dental care visits among young, low-income African-American children. They found that children with private dental insurance were five times more likely and children receiving Medicaid were about two times more likely to have visited a dentist than those without dental insurance.

Caregivers' preventive dental visits related to their children seeing dentist

The researchers also found an association between a caregiver's prevention-oriented dental visit and their child seeing a dentist.

Caregivers who had had preventive dental visits were five times more likely to have taken their children to a dentist than caregivers who sought dental care only for treatment or not at all.

According to the researchers, this provides an explanation of an earlier finding that free care is not sufficient to eliminate differences in dental care utilization and oral health among underserved children......... Posted by: Sean      Read more         Source

March 19, 2007, 9:45 PM CT

How Computers and Electronics Work

Scientists have made an important advance in the emerging field of 'spintronics' that may one day usher in a new generation of smaller, smarter, faster computers, sensors and other devices, as per findings reported in today's issue of the journal Nature Nanotechnology.

The research field of 'spintronics' is concerned with using the 'spin' of an electron for storing, processing and communicating information.

The research team of electrical and computer engineers from the Virginia Commonwealth University's School of Engineering and the University of Cincinnati examined the 'spin' of electrons in organic nanowires, which are ultra-small structures made from organic materials. These structures have a diameter of 50 nanometers, which is 2,000 times smaller than the width of a human hair. The spin of an electron is a property that makes the electron act like a tiny magnet. This property can be used to encode information in electronic circuits, computers, and virtually every other electronic gadget.

"In order to store and process information, the spin of an electron must be relatively robust. The most important property that determines the robustness of spin is the so-called 'spin relaxation time,' which is the time it takes for the spin to 'relax.' When spin relaxes, the information encoded in it is lost. Therefore, we want the spin relaxation time to be as long as possible," said corresponding author Supriyo Bandyopadhyay, Ph.D., a professor in the Department of Electrical and Computer Engineering at the VCU School of Engineering......... Posted by: Kevin      Read more         Source

March 15, 2007, 9:20 PM CT

Global 'sunscreen' has likely thinned

A new NASA study has found that an important counter-balance to the warming of our planet by greenhouse gases sunlight blocked by dust, pollution and other aerosol particles appears to have lost ground.

The thinning of Earths "sunscreen" of aerosols since the early 1990s could have given an extra push to the rise in global surface temperatures. The finding, published recently in the journal Science, may lead to an improved understanding of recent climate change. In a related study published last week, scientists found that the opposing forces of global warming and the cooling from aerosol-induced "global dimming" can occur at the same time.

"When more sunlight can get through the atmosphere and warm Earth's surface, you're going to have an effect on climate and temperature," said lead author Michael Mishchenko of NASA's Goddard Institute for Space Studies (GISS), New York. "Knowing what aerosols are doing globally gives us an important missing piece of the big picture of the forces at work on climate".

The study uses the longest uninterrupted satellite record of aerosols in the lower atmosphere, a unique set of global estimates funded by NASA. Scientists at GISS created the Global Aerosol Climatology Project by extracting a clear aerosol signal from satellite measurements originally designed to observe clouds and weather systems that date back to 1978. The resulting data show large, short-lived spikes in global aerosols caused by major volcanic eruptions in 1982 and 1991, but a gradual decline since about 1990. By 2005, global aerosols had dropped as much as 20 percent from the relatively stable level between 1986 and 1991......... Posted by: Brooke      Read more         Source

March 15, 2007, 8:52 PM CT

Chemical breakthrough at FSU

"Build a better mousetrap," the saying goes, "and the world will beat a path to your door." In the complex field of organic chemistry, that path leads to Florida State University, where a newly developed substance could make the jobs of researchers throughout the world a little easier as they work to develop new drugs and other chemicals that benefit humanity.

Scientists from the Dudley Laboratory at FSU have invented a reagent a substance used in a chemical reaction to detect, measure, examine or produce other substances that can trap specific regions of complex molecules in such a way that those molecules can be released at a later time. This will allow researchers to perform complex experiments involving chemical synthesis much more easily and precisely.

"It isn't every day that one can put a new product on the market," said Gregory B. Dudley, an assistant professor of chemistry and biochemistry at FSU whose research lab bears his name.

"Even more exciting for me is the knowledge that scientific breakthroughs in biomedical research and various other areas of organic chemistry might be made possible as a result of this reagent," Dudley said.

The Sigma-Aldrich Chemical Company has licensed Dudley's patent-pending reagent from FSU and recently began marketing it to chemical research labs worldwide under the name "Bn-OPT" short for BeNzylOxyPyridinium Triflate. FSU will receive royalties from Sigma-Aldrich in the amount of 5 percent of net sales of the reagent......... Posted by: Sarah      Read more         Source

March 15, 2007, 6:09 PM CT

Ice created in nanoseconds

Sandias huge Z machine, which generates termperatures hottter than the sun, has turned water to ice in nanoseconds.

However, dont expect anything commercial just yet: the ice is hotter than the boiling point of water.

"The three phases of water as we know them cold ice, room temperature liquid, and hot vapor are actually only a small part of waters repertory of states," says Sandia researcher Daniel Dolan. "Compressing water customarily heats it. But under extreme compression, it is easier for dense water to enter its solid phase [ice] than maintain the more energetic liquid phase [water]".

Sandia is a National Nuclear Security Administration (NNSA) laboratory.

In the Z experiment, the volume of water shrank abruptly and discontinuously, consistent with the formation of almost every known form of ice except the ordinary kind, which expands. (One might wonder why this ice shrank instead of expanding, given the common experience of frozen water expanding to wreck garden hoses left out over winter. The answer is that only "ordinary" ice expands when water freezes. There are at least 11 other known forms of ice occurring at a variety of temperatures and pressures.).

"This work," says Dolan, "is a basic science study that helps us understand materials at extreme conditions"......... Posted by: Kevin      Read more         Source

March 14, 2007, 10:32 PM CT

A Boost for Hydrogen Fuel Cell Research

The development of hydrogen fuel cells for vehicles, the ultimate green dream in transportation energy, is another step closer. Scientists with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and Argonne National Laboratory (ANL) have identified a new variation of a familiar platinum-nickel alloy that is far and away the most active oxygen-reducing catalyst ever reported.

The slow rate of oxygen-reduction catalysis on the cathode - a fuel cell's positively charged electrode - has been a primary factor hindering development of the polymer electrolyte membrane (PEM) fuel cells favored for use in vehicles powered by hydrogen.

"The existing limitations facing PEM fuel cell technology applications in the transportation sector could be eliminated with the development of stable cathode catalysts with several orders of magnitude increase in activity over today's state-of-the-art catalysts, and that is what our discovery has the potential to provide," said Vojislav Stamenkovic, a scientist with dual appointments in the Materials Sciences Division of both Berkeley Lab and Argonne.

Stamenkovic and Argonne senior scientist Nenad Markovic are the corresponding authors of a study whose results are now available online from the journal Science. The paper, entitled Improved Oxygen Reduction Activity on Pt3Ni(111) via Increased Surface Site Availability, reports a platinum-nickel alloy that increased the catalytic activity of a fuel cell cathode by an astonishing 90-fold over the platinum-carbon cathode catalysts used today......... Posted by: Sarah      Read more         Source

March 14, 2007, 10:12 PM CT

New Mammal From Mesozoic Era

n international team of American and Chinese paleontologists has discovered a new species of mammal that lived 125 million years ago during the Mesozoic Era, in what is now the Hebei Province in China.

The new mammal, documented in the March 15 issue of the journal Nature, provides first-hand evidence of early evolution of the mammalian middle ear--one of the most important features for all modern mammals. The discovery was funded by the National Science Foundation (NSF).

"This early mammalian ear from China is a rosetta-stone type of discovery which reinforces the idea that development of complex body parts can be explained by evolution, using exquisitely preserved fossils," said H. Richard Lane, program director in NSF's Division of Earth Sciences, which co-funded the discovery with NSF's Division of Environmental Biology and its Assembling the Tree of Life (AToL) program.

Named Yanoconodon allini after the Yan Mountains in Hebei, the fossil was unearthed in the fossil-rich beds of the Yixian Formation and is the first Mesozoic mammal recovered from Hebei. The fossil site is about 300 kilometers outside of Beijing.

The scientists discovered that the skull of Yanoconodon revealed a middle ear structure that is an intermediate step between those of modern mammals and those of near relatives of mammals, also known as mammaliaforms......... Posted by: William      Read more         Source

March 14, 2007, 9:59 PM CT

Call to End FDA User Fee System

Opposition to current drug safety legislation is growing, as a group of 22 experts on drug safety and regulation and a coalition of 12 patient, consumer, science, and public health organizations issue two separate open letters to lawmakers. The letter from FDA experts asks the lawmakers to not reauthorize the user fees system that finances the review of new drugs by the Food and Drug Administration (FDA). The letter from the coalition of nonprofit organizations calls for substantial changes to the Enhancing Drug Safety and Innovation Act introduced by Senators Kennedy and Enzi.

"User fees may appear to save the taxpayer money, but at an unacceptable cost to public health," the letter from the 22 experts warns, citing findings of a panel of experts recently convened by the Institute of Medicine (IOM) to address drug safety at the FDA. They call for Congress and the nation to carefully reassess the system in which drugs are developed, tested, approved and followed post-approval, and they support replacing the current user fee model with increased direct appropriations for the FDA. The letter is also signed by drug safety expert Dr. Jerome Avorn; four IOM panel members including Dr. Bruce Psaty and Prof. Alta Charo; three former Editors-in-Chief of the New England Journal (NEJM), Dr. Marcia Angell, Dr. Jerome Kassirer, and Dr. Arnold Relman; and former Asst. Secretary for Health Phil Lee, along with other respected experts from medicine, academia, and public policy......... Posted by: Sean      Read more         Source

March 13, 2007, 9:38 PM CT

Fossil From 160,000 Years Ago Resemble Modern Man

An international team of researchers have observed that the oldest member (160,000 years old) of the genus Homo shows a life history profile similar to modern humans. These findings, based on experiments at ESRF, are in contrast to prior studies suggesting that early fossil humans possessed short growth periods, which were more similar to chimpanzees than to living humans.

The origins of modern humans continues to be one of the most hotly debated topics among anthropologists, and there is little consensus about where and when the first members of our species, Homo sapiens, became fully modern. While fossil evidence tells a complex tale of mosaic change during the African Stone Age, almost nothing is known about changes in human 'life history', or the timing of development, reproductive scheduling, and lifespan. Research during the past two decades has shown that early fossil humans (australopithecines and early Homo) possessed short growth periods, which were more similar to chimpanzees than to living humans. However, it is unclear when and in which group of fossil humans the modern condition of a relatively long childhood arose.

The team of researchers examined the tooth growth and eruption in a fossil from an 8 year old child using the unique tool that is the X-rays beams of the ESRF. The fossil is from one of the earliest representatives of Homo sapiens. It was found in Jebel Irhoud, Morocco and was dated to approximately 160,000 years ago......... Posted by: William      Read more         Source