April 10, 2007, 6:27 PM CT

Structural basis for photoswitching

University of Oregon researchers have identified molecular features that determine the light-emitting ability green fluorescent proteins, and by strategically inserting a single oxygen atom they were able to keep the lights turned off for up to 65 hours.

The findings, published online this week by the Proceedings of the National Academy of Sciences, likely are applicable to most photoswitchable fluorescent proteins, said S. James Remington, professor of physics and member of the UO Institute of Molecular Biology.

"This new model makes specific predictions and improves the qualities of the protein as a photo-switchable label," Remington said. "It gives us the first picture of how these molecules can be switched on and off. That allows us to design new variants to make the proteins more useful".

For more than a decade, fluorescent proteins first isolated in jellyfish and since found in a variety of colors from coral reef organisms revolutionized molecular biology, allowing researchers to use them as markers for genetic expression, to locate molecules and observe activity within cells.

The recent discovery of photoswitchable fluorescent proteins which can be manipulated with a laser has been a significant development for cellular research......... Posted by: Kevin      Read more         Source

April 2, 2007, 10:11 PM CT

Increasing Effectiveness Of Tsunami Warning

Researchers at the University of Nevada, Reno are at the forefront on many seismological fields, including helping the world better determine whether an earthquake is big enough to generate an ocean-wide tsunami.

Through work at the Nevada Seismological Laboratory on the Nevada campus, important data on seismological events throughout the world is compiled, including Mondays fatal occurrence in the Solomon Islands, where at least 13 people were killed. Tsunamis triggered by an undersea earthquake crashed ashore and wiped away entire villages and set off alerts from Australia to Hawaii.

A research team led by Geoffrey Blewitt of the Nevada Bureau of Mines and Geology and Seismological Laboratory has demonstrated that a large quakes true size can be determined within 15 minutes using Global Positioning System data. This swift exchange of information, which is much faster than is possible with current methods, can be critical in determining whether an earthquake might trigger a tsunami. Together with a seismometer and ocean buoy data, GPS has the potential to become an important tool in improving tsunami danger assessments, Blewitt said.

"We'll always need seismology as the first level of alert for large earthquakes, and we'll need ocean buoys to actually sense the tsunami waves," said Blewitt, whose work was originally accomplished through the NASA-funded Jet Propulsion Laboratory in Pasadena, Calif. Blewitts team recently was granted further funding from the U.S. Geological Surveys Natural Hazards Reduction Program to continue research and development......... Posted by: Tyler      Read more         Source

April 2, 2007, 10:07 PM CT

China's earliest modern human

Scientists at Washington University in St. Louis and the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing have been studying a 40,000-year-old early modern human skeleton found in China and have determined that the "out of Africa" dispersal of modern humans may not have been as simple as once thought.

The research result would be reported in the Proceedings of the U.S. National Academy of Sciences on April 3.

Erik Trinkaus, Professor of Anthropology at Washington University in St. Louis, his colleague Hong Shang, and others at the IVPP examined the skeleton, recovered in 2003 from the Tianyuan Cave, Zhoukoudian, near Beijing City.

The skeleton dates to 42,000 to 38,500 years ago, making it the oldest securely dated modern human skeleton in China and one of the oldest modern human fossils in eastern Eurasia.

The specimen is basically a modern human, but it does have a few archaic characteristics, especially in the teeth and hand bone. This morphological pattern implies that a simple spread of modern humans from Africa is unlikely, particularly since younger specimens have been found in Eastern Eurasia with similar feature patterns.

As per Trinkaus and Shang, "the discovery promises to provide relevant paleontological data for our understanding of the emergence of modern humans in eastern Asia"......... Posted by: William      Read more         Source

April 2, 2007, 10:05 PM CT

Supreme Court case on carbon dioxide emissions

Four faculty members from The University of Arizona in Tucson were part of an amicus curiae brief supporting the plaintiff in today's historic U.S. Supreme Court decision on carbon dioxide emissions and climate change.

In the case, Commonwealth of Massachusetts, et al. v. U.S. Environmental Protection Agency, several states sued the EPA for failure to regulate carbon dioxide emissions from motor vehicles as mandatory by the Clean Air Act.

Today the court decided in favor of Massachusetts, et al.

"This ruling is a victory for climate science," said UA ecologist Scott Saleska, the scientist who organized the scientists' collaboration on the brief. "EPA ignored what is perhaps the most important finding in climate science in the last decade, which is that the rise of global temperature and the anthropogenic increase in atmospheric CO2 are causally linked.

"The opening paragraph of the Court majority opinion cited that specific scientific finding".

UA researchers were leaders in the climate scientists' amicus curiae brief in support of the plaintiff. Scott Saleska, a UA assistant professor of ecology and evolutionary biology, organized the group of climate researchers to file the brief. Kirsten Engel, a UA professor of law, was one of only four lawyers on the amicus brief......... Posted by: Tyler      Read more         Source

April 2, 2007, 10:00 PM CT

Why the Rich Get Richer

A new theory shows how wealth, in different forms, can stick to some but not to others. The findings have implications ranging from the design of the Internet to economics.

Real-world data -- whether distributions of wealth, size of earthquakes or number of connections on a computer network -- often follow power-law distributions rather than the familiar bell-shaped curve. In a power-law distribution, large events are reasonably common compared to smaller events.

Networks often show power laws. They can be caused by the "rich get richer" effect, also known as "preferential attachment," where nodes gain new connections in proportion to how many they already have. That means some nodes end up with many more connections than others. The phenomenon is well known, but had been assumed to be just a fundamental property of networks.

Raissa D'Souza, an assistant professor at the Department of Mechanical and Aeronautical Engineering and the Center for Computational Science and Engineering at UC Davis, together with colleagues at Microsoft Research in Redmond, Wash., UCLA and Cornell University, looked at how "preferential attachment" can arise in networks.

"'The rich get richer' makes sense for wealth, but why would it happen for Internet routers?" she said......... Posted by: Kevin      Read more         Source

April 1, 2007, 9:45 PM CT

The world's largest particle accelerator

The last quadripolar magnet was brought down into the tunnel of the worlds largest particle accelerator; the CERNs1 LHC, or Large Hadron Collidor. This magnet is part of a series of 392 units which will ensure that the beams are kept on track all along their trajectory through the tunnel. Its installation marks the completion of a long and fruitful collaboration between the CERN, the CNRS/IN2P32 and the CEA/DSM3 in the field of superconductivity and advanced cryogenics. This collaboration has lasted over ten years and was part of the special contribution made by France, as the host country, to the construction of the LHC.

Built to answer the most fundamental questions in physics, the LHC accelerator is assembled at the CERN in a tunnel which has a circumference of 27 km and is buried 100 metres beneath the Franco-Swiss border. It is composed of 1700 large magnets of which 392 are quadripole magnets designed to guide and focus the beams. It also includes a significant quantity of corrective magnets. The final installation of the LHC will be completed in mid-2007, and start-up is planned for November 2007.

In order to meet the considerable technological challenges presented by the LHC, the CNRS, CEA and CERN collaborated closely in the construction of the accelerator. The protocol of collaboration amongst these three organizations was signed on February 14, 1996 in the presence of the Minister responsible for research......... Posted by: Sarah      Read more         Source

April 1, 2007, 9:39 PM CT

The gigantic respiration of crystalline solids

Previously, only amorphous polymer materials approached such levels of performance. Conversely, these gigantic respiration and their respiration, which takes place at constant overall shape, is reversible. This discovery, of interest for numerous industrial applications, is reported in the journal Science on March 30, 2007.

The phenomenon of respiration is normally linked to life. Typically it is characterized by a reversible variation in the volume of a species under the effect of a stimulus (gas, pressure, temperature, irradiation, etc.). The volume of the lungs, for example, expands by 40 percent when breathing in. Organic matter, known for its flexibility, is well suited to this phenomenon. Conversely, inorganic matter is very often linked to the idea of rigidity and non-deformability. Scientists from the Institut Lavoisier (CNRS/Universit de Versailles Saint-Quentin-en-Yvelines) have recently demonstrated that the hybrid material (which combines both inorganic and organic entities) can be deformed in a reversible manner.

Within the framework of their studies on porous systems, Grard Frey and his team at the Institut Lavoisier have discovered a new family of trivalent metal dicarboxylates, which possess unprecedented respiration properties. Depending on the nature of the organic entity, the variation in volume when these solids are immersed in a solvent (water, methanol, etc.) can exceed 300 percent. Only some amorphous polymers approach this level of performance. However, unlike such polymers, the new solids are crystalline. The scientists determined their crystallographic structure in each state (solvated or not) and provided an explanation for the respiration mechanism, which takes place at constant overall shape, without any apparent rupture of bonds at the atomic level. The reversibility of the phenomenon is therefore facilitated......... Posted by: Sarah      Read more         Source

April 1, 2007, 9:25 PM CT

Sleep Disturbance And Pain

Sleep continuity disturbance impairs endogenous pain-inhibitory function and increases spontaneous pain in women. This supports a possible pathophysiologic role of sleep disturbance in chronic pain, according to a study published in the April 1st issue of the journal SLEEP.

The study, conducted by Michael T. Smith, PhD, and colleagues at Johns Hopkins University, focused on 32 healthy females, who were studied polysomnographically for seven nights. On the first two nights, the subjects slept undisturbed for eight hours. Then, the women were assigned to one of three groups: "Control", "Forced Awakening" (FA) and "Restricted Sleep Opportunity" (RSO). From nights three-to-five, the "Control" group continued to sleep undisturbed, while the "Forced Awakening" group underwent eight forced awakenings, one per hour, and the "Restricted Sleep Opportunity" group received partial sleep deprivation by delayed bedtime. On night six, both the FA and RSO groups underwent 36 hours of total sleep deprivation, followed by 11-hour recovery sleep.

In an assessment of the subjects completion of twice-daily psychophysical assessments of mechanical pain thresholds and pain inhibition, it was discovered that the FA group demonstrated an increase in spontaneous pain, while neither the "Control" nor the RSO group showed changes in pain inhibition or spontaneous pain during partial sleep deprivation......... Posted by: Sean      Read more         Source

April 1, 2007, 8:56 PM CT

It's never too late to get your youth back

Much research has shown that reduced calorie intake can increase health and longevity. Professor Stephen Spindler (University of California) and his collaborators* have discovered that reducing calorie intake later in life can still induce many of the health and longevity benefits of life-long calorie reduction. Importantly, this also includes anti-cancer effects. They are using this knowledge to establish a novel screening technique to find drugs which mimic this longevity effect. Right now, there are no authentic anti-ageing drugs capable of extending the lifespan of healthy people. The technique we have developed allows us to screen a relatively large number of drugs in months rather than years. The hope is that these drugs will be able to extend the lifespan of healthy animals, and possibly, after further testing, healthy humans, says Professor Spindler who will present his results at the Society for Experimental Biologys Main Meeting in Glasgow on Monday 2nd April.

Previous research has show that mice can live up to 40% longer if they simply consume fewer calories, but a highly nutritious diet. Because people are not very good at dieting, Dr. Spindler and his colleagues would like to identify drugs which can produce the same beneficial health and longevity effects without the low calorie diet. The problem is to find a way to rapidly identify these drugs. Professor Spindler and his colleagues are examining the gene expression patterns which are induced by low calorie diets, and looking for drugs which mimic these changes. They are searching for drugs which will have these beneficial effects and slow ageing, even when they are given late in life. One drug, normally used to treat diabetic patients, seems to produce many of the beneficial effects of a low calorie diet. However, it is important to be sure that healthy people will benefit from the drug. A very low level of toxicity could interfere with the beneficial effects of such a drug, if it is taken for a lifetime......... Posted by: Sean      Read more         Source

March 29, 2007, 10:32 PM CT

Nanotubes Could Improve Thermal Management

As the electronics industry continues to churn out smaller and slimmer portable devices, manufacturers have been challenged to find new ways to combat the persistent problem of thermal management. New research reported in the March 19 issue of Applied Physics Letters suggests that carbon nanotubes may soon be integrated into ever-shrinking cell phones, digital audio players, and personal digital assistants to help ensure the equipment does not overheat, malfunction, or fail.

The chips inside an electronic device give off heat as a byproduct of power consumption when the object is on or being used. To reduce high temperatures, heat sinks - finned devices made of conductive metal such as aluminum or copper - are attached to the back of the chips to "pull" thermal energy away from the microprocessor and transfer it into the surrounding air. Fans or fluids are sometimes used to improve the cooling process, but they increase the device weight, size, and bulk.

Using microfin structures made of aligned multiwalled carbon nanotube arrays mounted to the back of silicon chips, scientists from Rensselaer Polytechnic Institute and the University of Oulu in Finland have proven that nanotubes can dissipate chip heat as effectively as copper - the best known, but most costly, material for thermal management applications. And the nanotubes are more flexible, resilient, and 10 times lighter than any other cooling material available......... Posted by: Kevin      Read more         Source