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June 2, 2009 at 5:44 PM
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Laser makes light bulbs super-efficient

ROCHESTER, N.Y., June 2 (UPI) -- U.S. scientists have used an ultra-powerful laser to turn regular incandescent light bulbs into super-efficient sources of light.

University of Rochester (N.Y.) researchers said the laser creates a unique array of nano- and micro-scale structures on the surface of a regular tungsten filament. It's those structures that make the tungsten emit light as bright as a 100-watt bulb, but consume less electricity than a 60-watt bulb.

"We've been experimenting with the way ultra-fast lasers change metals, and we wondered what would happen if we trained the laser on a filament," Associate Professor Chunlei Guo said. "We fired the laser beam right through the glass of the bulb and altered a small area on the filament. When we lit the bulb, we could actually see this one patch was clearly brighter than the rest of the filament, but there was no change in the bulb's energy usage."

The key to creating the super-filament is an ultra-intense beam of light called a femtosecond laser pulse. The researchers said the laser burst lasts only a few quadrillionths of a second, but it unleashes as much power as the entire electricity grid of North America onto a spot the size of a needle point.

The findings are to appear in an upcoming issue of the journal Physical Review Letters.

Drug may prevent brain injury epilepsy

ST. LOUIS, June 2 (UPI) -- U.S. researchers have found an FDA-approved drug that might prevent genetically caused epilepsy also might help prevent more common forms of the condition.

Washington University School of Medicine researchers in St. Louis said they found the drug rapamycin may also help prevent forms of epilepsy caused by brain injury.

The scientists determined rapamycin blocks brain changes believed to cause seizures in rats. In a paper last year, the same group showed rapamycin prevents brain changes in mice triggered by one of the most common genetic causes of epilepsy, tuberous sclerosis.

"We hope to shift the focus from stopping seizures to preventing the brain abnormalities that cause seizures in the first place, and our results in the animal models so far have been encouraging," Dr. Michael Wong, senior author of the research, said.

"Researchers have traditionally tested potential epilepsy drugs on animals that were already having seizures," Wong added. "We may be able to improve our success rate by stepping back a little and trying to find a treatment that can halt the disease process prior to the start of seizures."

The study that included postdoctoral fellow Ling-Hui Zeng appears in the May 27 issue of The Journal of Neuroscience.

Cyclones, global warming linkage found

NEW HAVEN, Conn., June 2 (UPI) -- Harvard University scientists say they've discovered a possible link between the development of tropical cyclones and global warming.

David Romps and Zhiming Kuang of Harvard's Department of Earth and Planetary Sciences said cyclones could be a significant source of the deep convection that carries moist air upward to the stratosphere, where it can influence climate.

After analyzing 23 years of infrared satellite imagery, global tropical cyclone track data and other data, the researchers discovered that while tropical cyclones account for only 7 percent of the deep convection in the tropics, such storms contribute 15 percent of the convection that reaches the stratosphere.

Romps and Kuang said they conclude tropical cyclones could play a key role in adding water vapor to the stratosphere, which has been shown to increase surface temperatures. Because global warming is expected to lead to changes in the frequency and intensity of tropical cyclones, the researchers said their results suggest the possibility of a feedback mechanism between tropical cyclones and global climate.

The study appears in the journal Geophysical Research Letters.

Digital library/search engine is created

STATE COLLEGE, Pa., June 2 (UPI) -- U.S. researchers have created a digital library and search engine that now holds more than 1 million journal articles and can be easily accessed by anyone.

Pennsylvania State University scientists said the library, called CiteSeerX, is based in the university's College of Information Sciences and Technology. It is designed to "enhance the dissemination of scientific literature by making papers and other documents easier to locate online," the school said.

The library provides resources such as algorithms, data, metadata, services, techniques and software that are transferable to other digital libraries, officials said. It also has the capability to search tables and is based on open-source software, meaning it can be adapted as needed to fit a user's requirements.

"We won't keep it to ourselves," said Professor C. Lee Giles, who developed the technology. "We'll give it to other people and they can build similar systems. Because it's modular, it can be changed to meet their needs."

Another feature, called MyCiteSeerX, is a customizable personal space where individual users can do tagging, make corrections, create a collection and monitor paper updates.

CiteSeerX was funded by the National Science Foundation, the Microsoft Corp., the National Aeronautics and Space Administration and the university.

The library is available at http://citeseerx.ist.psu.edu.

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