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February 26, 2007, 8:55 PM CT

how marine turtles return to the same beach?

how marine turtles return to the same beach? Atlantic Loggerhead
Marine turtles almost always return to the same beach to lay their eggs. The egg-laying sites are often far from the feeding areas and the females cross several hundred kilometers of ocean with no visual landmarks. How do they manage to return to the same spot? A study by Simon Benhamou of the Center for Functional and Evolutionary Ecology at Montpellier1, France, together with other groups (CNRS, IRD, IFREMER, CEDTM2, University of Pisa), shows that the marine turtles use a relatively simple navigation system involving the earths magnetic field, and this allows them to return to the same egg-laying site without having the ability to correct for the deflection of ocean currents. This work, published in Current Biology and Marine Ecology Progress Series, should allow better conservation strategies for this endangered species.

Every 4 years, on average, Indian Ocean green turtles (Chelonia mydas) travel hundreds of kilometers to specific egg-laying areas, where they will lay 4 to 6 successive clutches. To better understand the navigation process and the sensory channels involved in this long-distance oceanic travel, the researchers have conducted a multidisciplinary study, involving biology and physical oceanography, in two series of experiments. In the Mozambique Channel, between the east coast of Africa and Madagascar, on the beaches of the French Islands of Europa and Mayotte, they caught turtles at the beginning of their egg-laying cycle, so that the animals were strongly impelled to return to this area to complete their cycle. After having Argos transmitters fitted to their shells in order to satellite track their return journey to the beach, the animals were released in open sea, several hundred kilometers from the egg-laying site.........

Posted by: Nora      Read more         Source


February 26, 2007, 7:10 PM CT

South Pole Telescope achieves first light

South Pole Telescope achieves first light
Researchers aimed the South Pole Telescope at Jupiter on the evening of Feb. 16 and successfully collected the instrument's first test observations. Soon, far more distant quarry will fall under the SPT's sights as a team from nine institutions tackles one of the.

biggest mysteries of modern cosmological research. That mystery: What is dark energy, the force that dominates the universe?

"The telescope, camera and optics are all working as.

designed," said John Carlstrom, the S. Chandrasekhar Distinguished Service Professor in Astronomy & Astrophysics at the University of.

Chicago, who heads the SPT Team. "First light with the SPT is a major milestone for the project and is a fitting conclusion to a remarkably productive summer season for the South Pole Station. We now look.

forward to fully characterizing the instrument and beginning cosmological observations," he said.

The $19.2 million SPT is funded primarily by the National Science Foundation, with additional support from the Kavli Foundation of Oxnard, Calif., and the Gordon and Betty Moore Foundation of San Francisco.

The telescope stands 75 feet tall, measures 33 feet across and weighs 280 tons. It was test-built in Kilgore, Texas, then taken apart, shipped by boat to New Zealand, and flown to the South Pole. Since November, the SPT team under the guidance of project manager Steve Padin, Senior Scientist in Astronomy & Astrophysics at the University of Chicago, has worked furiously to reassemble and deploy the telescope.........

Posted by: Edwin      Read more         Source


February 26, 2007, 7:07 PM CT

Northwest Atlantic Ocean Ecosystems

Northwest Atlantic Ocean Ecosystems
Ecosystems along the continental shelf waters of the Northwest Atlantic Ocean--from the Labrador Sea south of Greenland all the way to North Carolina--are experiencing large, rapid changes, report oceanographers funded by the National Science Foundation (NSF) in the Feb. 23, 2007, issue of the journal Science.

While some scientists have pointed to the decline of cod from overfishing as the main reason for the shifting ecosystems, the paper emphasizes that climate change is also playing a big role.

"It is becoming increasingly clear that Northwest Atlantic ecosystems are being affected by climate forcing from the bottom up and overfishing from the top down," said Charles Greene, an oceanographer at Cornell University in Ithaca, N.Y, and lead author of the Science paper. "Predicting the fate of these ecosystems will be one of oceanography's grand challenges for the 21st century".

Most scientists believe humans are warming the planet by burning fossil fuels and changing land surfaces. Early signs of this warming have appeared in the Arctic. Since the late 1980s, scientists have noticed that pulses of fresh water from increased precipitation and melting of ice on land and sea in the Arctic have flowed into the North Atlantic Ocean and made the water less salty.........

Posted by: Nora      Read more         Source


February 26, 2007, 7:04 PM CT

South Pole Telescope To Help Scientists

South Pole Telescope To Help Scientists Image courtesy of South pole telescope
Just days before nations around the world were set to begin a coordinated global research campaign called the International Polar Year (IPY); researchers at the South Pole aimed a massive new telescope at Jupiter and successfully collected the instrument's first test observations.

Soon, a far more distant quarry will enter the South Pole telescope's (SPT) sights, as a team of scientists from nine institutions tackles fundamental mysteries of modern cosmology and the nature of the universe: What, for example, is dark energy, the force that dominates the universe?

The $19.2 million telescope is funded primarily by the National Science Foundation (NSF), with additional support from the Kavli Foundation of Oxnard, Calif., and the Gordon and Betty Moore Foundation of San Francisco.

"The telescope, camera and optics are all working as designed," said John Carlstrom, the S. Chandrasekhar distinguished service professor in astronomy and astrophysics at the University of Chicago, who heads the SPT team that tested the scope on Feb. 26. "SPT's first light is a major milestone for the project and a fitting conclusion to a remarkably productive summer at the South Pole station. We now look forward to fully characterizing the instrument and beginning cosmological observations".........

Posted by: Nora      Read more         Source


February 21, 2007, 9:25 PM CT

Biologically inspired sensors

Biologically inspired sensors
o find prey and avoid being preyed upon, fish rely on a row of specialized sensory organs along the sides of their bodies, called the lateral line. Now, a research team led by Chang Liu at the University of Illinois at Urbana-Champaign has built an artificial lateral line that can provide the same functions in underwater vehicles.

"Our development of an artificial lateral line is aimed at enhancing human ability to detect, navigate and survive in the underwater environment," said Liu, a Willett Scholar and a professor of electrical and computer engineering at Illinois. "Our goal is to develop an artificial device that mimics the functions and capabilities of the biological system".

In fish, the lateral line provides guidance for synchronized swimming, predator and obstacle avoidance, and prey detection and tracking. Equipped with an artificial lateral line, a submarine or underwater robot could similarly detect and track moving underwater targets, and avoid collisions with moving or stationary objects.

The artificial lateral line consists of an integrated linear array of micro fabricated flow sensors, with the sizes of individual sensors and spacings between them matching those of their biological counterpart.

"By detecting changes in water pressure and movement, the device can supplement sonar and vision systems in submarines and underwater robots," said Liu, who also is affiliated with the universitys Beckman Institute for Advanced Science and Technology, the Institute for Genomic Biology, and the Micro and Nanotechnology Laboratory.........

Posted by: John      Read more         Source


February 21, 2007, 9:23 PM CT

Creates Metallic Interconnects, Nanostructures

Creates Metallic Interconnects, Nanostructures
reating high-resolution metallic interconnects is an essential part of the fabrication of microchips and other nanoscale devices. Scientists at the University of Illinois at Urbana-Champaign have developed a simple and robust electrochemical process for the direct patterning of metallic interconnects and other nanostructures.

"Solid-state superionic stamping offers a new approach, both as a stand-alone process and as a complement to other nanofabrication techniques, for creating chemical sensors, photonic structures and electrical interconnects," said Nicholas X. Fang, a professor of mechanical science and engineering, and corresponding author of a paper reported in the Feb. 14 issue of the journal Nano Letters.

The S4 process uses a patterned superionic material as a stamp, and etches a metallic film by an electrochemical reaction. In superionic materials, metal ions can move almost freely around the crystal lattice. These mobile materials can also be used in batteries and fuel cells.

Unlike conventional processing in which patterns are first placed on photoresist, followed by metal deposition and subsequent etching the S4 process creates.

high-resolution metallic nanopatterns in a single step, potentially reducing manufacturing costs and increasing yields.........

Posted by: John      Read more         Source


February 21, 2007, 9:09 PM CT

Bacteria to steady buildings against earthquakes

Bacteria to steady buildings against earthquakes
Soil bacteria could be used to help steady buildings against earthquakes, as per scientists at UC Davis. The microbes can literally convert loose, sandy soil into rock.

When a major earthquake strikes, deep, sandy soils can turn to liquid, with disastrous consequences for buildings sitting on them. Currently, civil engineers can inject chemicals into the soil to bind loose grains together. But these epoxy chemicals may have toxic effects on soil and water, said Jason DeJong, an assistant professor of civil and environmental engineering at UC Davis.

The new process, so far tested only at a laboratory scale, takes advantage of a natural soil bacterium, Bacillus pasteurii. The microbe causes calcite (calcium carbonate) to be deposited around sand grains, cementing them together. By injecting bacterial cultures, additional nutrients and oxygen, DeJong and colleagues observed that they could turn loose, liquefiable sand into a solid cylinder.

"Starting from a sand pile, you turn it back into sandstone," DeJong said. Similar techniques have been used on a smaller scale, for example, to repair cracks in statues, but not to reinforce soil.

The new method has several advantages, DeJong said. There are no toxicity problems, compared with chemical methods. The therapy could be done after construction or on an existing building, and the structure of the soil is not changed -- some of the void spaces between grains are just filled in.........

Posted by: Nora      Read more         Source


February 20, 2007, 8:45 PM CT

Formation of auroras

Formation of auroras Auroras form in high latitude regions of Earth, and appear in many different shapes.
Credits: Jan Curtis, Fairbanks, Alask
Giant electrical circuits power the magical open-air light show of the auroras, forming arcs in high-latitude regions like Scandinavia. New results obtained thanks to ESA's Cluster satellites provide a new insight into the source of the difference between the two types of electrical circuits currently known to be associated to the auroral arcs.

The deep mechanisms that rule the creation of the beautiful auroras, or polar lights, have been the subject of studies that are keeping solar and plasma researchers busy since years. While early rockets and ground-observations have already provided a few important clues for the understanding of these phenomena, the real break-throughs in our knowledge have started with dedicated auroral satellites, such as S3-3, Dynamics Explorer, Viking, Freja and FAST, and have now come to full fruition with ESA's multi-point mission Cluster.

The basic process generating auroras is similar to what happens in an old TV tube. In the TV tube, accelerated electrons hit the screen and make its phosphore glow; electrons in the atmosphere get accelerated in an 'acceleration region' situated between about 5000 and 8000 kilometres altitude, and rush down to the Earth's ionosphere - a region of the upper atmosphere. Here, they crash into ionospheric atoms and molecules, transfer to them some of their energy and so cause them to glow, creating aurorae.........

Posted by: Edwin      Read more         Source


February 19, 2007, 8:58 PM CT

The science behind a wrinkle-filler

The science behind a wrinkle-filler
The current battle between the makers of anti-wrinkle products widely compared with the Coke and Pepsi struggle for superiority is receiving an injection of scientific understanding with the release of a new study from the University of Michigan Health System.

The study is the first to discover that one of the fillers known by the brand-name Restylane works by stretching fibroblasts, the cells in the skin that make collagen, in a way that causes the skin to create new collagen. This new, natural collagen then would contribute to the reduction of the appearance of creases and wrinkles. The study also shows that the product seems to inhibit the breakdown of existing collagen.

Prior to our research, it has been thought that Restylanes physical volume caused the improvement in the appearance of ones skin, says senior author John J. Voorhees, M.D., the Duncan and Ella Poth Distinguished Professor and chair of the Department of Dermatology at the U-M Medical School.

It is true that the physical presence of the product increases volume in the skin. Our research makes clear that injection of the product leads to creation of new collagen, which contributes to reduction in creases and wrinkles in a persons aging skin, Voorhees says.

The paper appears in the new issue of the journal Archives of Dermatology. Funding was provided by the U-M Department of Dermatology Cosmetic Research Fund, the Babcock Research Endowment at U-M and grants from the National Institutes of Health.........

Posted by: Nora      Read more         Source


February 19, 2007, 8:27 PM CT

Where is Beagle 2?

Where is Beagle 2?
NASA's Mars Reconnaissance Orbiter (MRO) spacecraft has used its onboard High Resolution Imaging Science Experiment camera (HiRISE) to take a colour image of a region of Mars in the vicinity of the intended landing site of Beagle 2.

H20 crater.

Credit: NASA's Mars Reconnaissance OrbiterIncluded in the image is new coverage of the crater H2O which was considered by the Beagle 2 team as unique in the area that had been searched for evidence of the missing Lander. Beagle 2 was targeted to land in an ellipse approximately 50km x 10km in size.

The new image does not show any features inside the crater that can be reconciled with peculiarities (i.e. possible components of the entry descent and landing system) encountered in the two prior lower resolution images taken soon after Beagle 2 was due to arrive on Mars in December 2003. The prior images were captured by the Mars Orbiter Camera on NASA's Mars Global Surveyor spacecraft.

Commenting on the latest image, Prof Colin Pillinger of the Open University and lead scientist for Beagle 2, said "Of course this is disappointing. We had hoped that the HiRISE camera would clarify the oddities we had seen in the crater but this is not the case. Nevertheless, I am extremely grateful to the camera team at NASA's Jet Propulsion Laboratory and the University of Arizona for trying and congratulate them on the exceptional quality of the images. I remain optimistic that future images may yet show us where Beagle 2 finally came to rest".........

Posted by: Edwin      Read more         Source


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