October 30, 2007, 10:13 PM CT

Elusive jellyfish more than 500 million years old

Using recently discovered fossil snapshots found in rocks more than 500 million years old, three University of Kansas scientists have described the oldest definitive jellyfish ever found.

In a paper would be published in PLoS ONE on October 31, the scientists describe four types of cnidarian fossils preserving traits that allow them to be correlation to modern orders and families of jellyfish. The specimens are about 200 million years older than the oldest previously discovered jellyfish fossils.

The fossil record is full of circular shaped blobs, some of which are jellyfish, said Paulyn Cartwright, KU assistant professor of ecology and evolutionary biology and one of the articles authors. Thats one of the reasons the fossils we describe are so interesting, because you can see a distinct bell-shape, tentacles, muscle scars and possibly even the gonads.

The jellyfish left behind a film in fine sediment that resembles a picture of the animal. Most jellyfish do not leave such a clear impression behind because they are often preserved in coarse sand.

Cartwright, Bruce Lieberman, KU professor of geology and senior curator of invertebrate paleontology at the KU Natural History Museum, and Jonathan Hendricks, postdoctoral researcher in geology at KU, collaborated on the article. Their research will be published October 31 in PLoS ONE, an online peer-evaluated journal by the Public Library of Science. Other scientists involved in the discoveries were Susan L. Halgedahl and Richard D. Jarrard, both of the University of Utah, Salt Lake City, Utah; Antonio C. Marques, University of San Paulo, San Paulo, Brazil; and Allen G. Collins, Smithsonian Institution, Washington, D.C......... Posted by: William      Read more         Source

October 30, 2007, 9:59 PM CT

Wireless Sensors To Monitor Bearings In Jet Engines

working with the U.S. Air Force, have developed tiny wireless sensors resilient enough to survive the harsh conditions inside jet engines to detect when critical bearings are close to failing and prevent breakdowns.

The devices are an example of an emerging technology known as "micro electromechanical systems," or MEMS, which are machines that combine electronic and mechanical components on a microscopic scale.

"The MEMS technology is critical because it needs to be small enough that it doesn't interfere with the performance of the bearing itself," said Farshid Sadeghi, a professor of mechanical engineering. "And the other issue is that it needs to be able to withstand extreme heat".

The engine bearings must function amid temperatures of about 300 degrees Celsius, or 572 degrees Fahrenheit.

The scientists have shown that the new sensors can detect impending temperature-induced bearing failure significantly earlier than conventional sensors.

"This kind of advance warning is critical so that you can shut down the engine before it fails," said Dimitrios Peroulis, an assistant professor of electrical and computer engineering.

Findings will be detailed in a research paper to be presented on Tuesday (Oct. 30) during the IEEE Sensors 2007 conference in Atlanta, sponsored by the Institute of Electrical and Electronics Engineers. The paper was written by electrical and computer engineering graduate student Andrew Kovacs, Peroulis and Sadeghi......... Posted by: Kevin      Read more         Source

October 30, 2007, 9:53 PM CT

Going Live With Click Chemistry

Click chemistry, one of the most exciting and proficient new techniques for labeling biomolecules in vitro, has now been extended to studies in the context of live cells as well. This breakthrough opens the door for applications to live cell imaging of numerous biomolecules, including glycans, proteins and lipids. The new version of click chemistry was developed by scientists with the Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) at Berkeley.

"We've developed a copper-free variant of the click chemistry reaction that possesses comparable kinetics to the copper-catalyzed reaction and proceeds within minutes on live cells with no apparent toxicity," said chemist Carolyn Bertozzi, the principal investigator on this project. "This is the first example of a click chemistry reaction that, like the copper-catalyzed version, proceeds at physiologically acceptable temperatures only without the toxic presence of copper".

Bertozzi is the director of Berkeley Lab's Molecular Foundry, a faculty scientist with Berkeley Lab's Materials Sciences and Physical Biosciences Divisions, the T.Z. and Irmgard Chu Distinguished Professor of Chemistry, and a professor of Molecular and Cell Biology at UC Berkeley. She is also an investigator with the Howard Hughes Medical Institute (HHMI), and a leading authority on glycobiology......... Posted by: Sarah      Read more         Source

October 29, 2007, 10:14 PM CT

Blue Mountain rocks related to Klamath

New evidence, based on mineral dating, suggests that rocks of the Blue Mountains, the oldest geological formation in Oregon, may have been derived from the Klamath and Sierra Nevada mountain chains, University of Oregon scientists report.

The findings, presented today (Oct. 29) at the annual meeting of the Geological Society of America, come from zircon grains in Triassic and Jurassic sedimentary rocks (dating from 144 million to 248 million years ago) from Blue Mountain basins in northeastern Oregon. The approximate ages of the zircons, based on isotropic dating, match the ages of rocks to the south in the Klamath Mountains, said Todd LaMaskin, a UO doctoral student in geological sciences.

Detrital zircon dating is a much-used technique that uses isotopes of uranium and lead from zircon grains found in sedimentary rocks, commonly sandstones. Such dating allows geologists to look back in time by billions of years.

"Zircons are very stable, can be weathered out of a rock, transported long distances and deposited in sedimentary basins," LaMaskin said. "We start with a block of sandstone, haul it out, crush it and mill it, and use various chemical and magnetic techniques to concentrate the zircons. We might start with 40 pounds of sandstone and end up with 100 to 200 zircons, all of which would fit on the head of a pin"......... Posted by: Tyler      Read more         Source

October 28, 2007, 4:22 PM CT

Agricultural Soil Erosion Is Not Adding to Global Warming

Agricultural soil erosion is not a source of carbon dioxide to the atmosphere, as per research published online today (October 25) in the journal Science. The study was carried out by an international team of scientists from UC Davis, the Catholic University of Leuven in Belgium, and the University of Exeter in the U.K.

Carbon emissions are of great concern worldwide because they, and other greenhouse gases, trap heat in the Earth's atmosphere and are a major cause of global climate change.

"There is still little known about how much carbon exactly is released, versus captured, by different processes in terrestrial ecosystems," said Johan Six, a professor of agroecology at UC Davis and one of the study's authors. "We urgently need to quantify this if we are to develop sensible and cost-effective measures to combat climate change".

In their new study, the scientists observed that erosion acts like a conveyor belt, excavating subsoil, passing it through surface soils and burying it in hollows downhill. During its journey, the soil absorbs carbon from plant material; when the soil is buried, so is the carbon.

Erosion, therefore, creates what can be described as a "sink" of atmospheric carbon.

The team improved prior estimates of the amount of carbon being sunk. Said lead author Kristof Van Oost of the Catholic University of Leuven, "Some academics have argued that soil erosion causes considerable emissions of carbon, and others that erosion is actually offsetting fossil-fuel emissions. Now, our research clearly shows that neither of these is the case"......... Posted by: Tyler      Read more         Source

October 28, 2007, 4:19 PM CT

Mars With Ice, Shaken, Not Stirred

Mars, like Earth, is a climate-fickle water planet. The main difference, of course, is that water on the frigid Red Planet is rarely liquid, preferring to spend almost all of its time traveling the world as a gas or churning up the surface as ice. That's the global picture literally and figuratively coming into much sharper focus as various Mars-orbiting cameras send back tomes of unprecedented super high-resolution imagery of ever vaster tracts of the planet's surface.

What were just a few years ago small hints about Mars' water and climate, as seen in a few "postage-stamp" high-resolution images and topography, have given way to broader theory that explains not only the features seen on the planet today, but imply a dynamic history of Martian climate change.

"When you have postage stamps, it's like studying a hair on an arm instead of the whole arm," said Mars researcher James Head III of Brown University. Head will present the latest integrated global view of Martian surface features and how they fit with Martian climate models on Sunday, 28 October 2007, at the Geological Society of America Annual Meeting in Denver.

The pictures now reveal a range of ice-made features that show a strong preference to certain latitudes, Head explains. As on Earth, latitude-dependent features can mean only one thing: latitude-dependent climate......... Posted by: Brooke      Read more         Source

October 28, 2007, 4:13 PM CT

Less Arctic ice means higher risks

The International Ice Charting Working Group predicts more marine transportation in the Arctic as sea ice continues to diminish and warns of "significant hazards to navigation," as per a statement released yesterday.

The statement was released during a five-day conference held at ESRIN, ESA's Earth Observation Centre in Frascati, Italy, in which operational ice experts from Europe and North America gathered to discuss the state of the polar regions.

"In September 2007, the Arctic sea ice reached the minimum extent - the lowest amount of ice recorded in the area annually - in the history of ice charting based on satellite, aircraft and surface observations, continuing a recent trend of diminishing sea ice that began in the 1980s and has accelerated. While there will still be natural inter-annual variability, the decline is likely to continue," the statement reads.

"The Arctic is already experiencing an increase in shipping, primarily for oil and gas development and tourism, and we can expect to see further increases as diminishing ice extent makes Arctic marine transportation more viable. The International Ice Charting Working Group (IICWG) cautions that sea ice and icebergs will continue to present significant hazards to navigation for the foreseeable future." ......... Posted by: Tyler      Read more         Source

October 28, 2007, 3:52 PM CT

UD researchers with latest spintronics achievement

In a rapid follow-up to their achievement as the first to demonstrate how an electron's spin can be electrically injected, controlled and detected in silicon, electrical engineers from the University of Delaware and Cambridge NanoTech now show that this quantum property can be transported a marathon distance in the world of microelectronics-- through an entire silicon wafer.

The finding confirms that silicon--the workhorse material of present-day electronics--now can be harnessed up for new-age spintronics applications.

The results, reported in the Oct. 26 issue of the American Physical Society's prestigious journal Physical Review Letters, mark another major steppingstone in the pioneering field of spintronics, which aims to use the intrinsic "spin" property of electrons versus solely their electrical charge for the cheaper, faster, lower-power processing and storage of data than present-day electronics can offer.

The research team included Ian Appelbaum, UD assistant professor of electrical and computer engineering, and his doctoral student, Biqin Huang, and Douwe Monsma, of Cambridge NanoTech in Cambridge, Mass. Huang was the lead author of the article.

"Our new result is significant because it means that silicon can now be used to perform a number of spin manipulations both within the space of thousands of devices and within the time of thousands of logic operations, paving the way for silicon-based spintronics circuits," Appelbaum said......... Posted by: Kevin      Read more         Source

October 28, 2007, 3:16 PM CT

Industrial-grade nanowire device fabrication

In the growing catalog of nanoscale technologies, nanowirestiny rows of conductor or semiconductor atomshave attracted a great deal of interest for their potential to build unique atomic-scale electronics. But before you can buy some at your local Nano Depot, manufacturers will need efficient, reliable methods to build them in quantity. Scientists at the National Institute of Standards and Technology (NIST) believe they have one solutiona technique that allows them to selectively grow nanowires on sapphire wafers in specific positions and orientations accurately enough to attach contacts and layer other circuit elements, all with conventional lithography techniques. They detailed their results in a recent paper.*.

Despite their name, nanowires are more than just electrical connectors. Scientists have used nanowires to create transistors like those used in memory devices and prototype sensors for gases or biomolecules. However working with objects only tens of nanometers wide is challenging. A common approach in the lab is to grow nanowires like blades of grass on a suitable substrate, mow them off and mix them in a fluid to transfer them to a test surface, using some method to give them a preferred orientation. When the carrier fluid dries, the nanowires are left behind like tumbled jackstraws. Using scanning probe microscopy or similar tools, scientists hunt around for a convenient, isolated nanowire to work on, or place electrical contacts without knowing the exact positions of the nanowires. Its not a technique suitable for mass production......... Posted by: Kevin      Read more         Source

October 28, 2007, 2:06 PM CT

Demand for Spanish-language cancer Web

Eventhough Spanish-speaking cancer patients are rapidly increasing their search for patient education resources on the Internet, there are very few Spanish-language Web sites available to provide this information, as per a research studypresented October 28, 2007, at the American Society for Therapeutic Radiology and Oncologys 49th Annual Meeting in Los Angeles.

Spanish-speaking cancer patients were also shown to have more limited access to the Internet in comparison to English-speaking users of cancer information Web sites, based on the user patterns of the two groups.

There is an urgent need for more Web-based information to be more available to Spanish-speaking patients with cancer, and Internet access needs to be more widely available, said Charles Simone II, M.D., lead author of the study and a radiation oncologist at the Hospital of the University of Pennsylvania in Philadelphia. The increased knowledge gained among these patients will help to eliminate healthcare disparities and lead to improved medical outcomes.

The Spanish-language cancer information Web site, OncoLink en espaol, quadrupled their number of unique visitors last year, from 7,000 visitors per month in January 2006 to nearly 29,000 monthly visitors by the end of the year. More than 200,000 users visited the Web site in 2006......... Posted by: Sean      Read more         Source