December 18, 2006, 9:30 PM CT

How To Avoid A Bat

Current understanding of the co-evolution of bats and moths has been thrown into question following new research reported today in Current Biology.

Dr James Windmill from the University of Bristol, UK, has shown how the Yellow Underwing moth changes its sensitivity to a bat's calls when the moth is being chased. And in case there is another attack, the moth's ear remain tuned in for several minutes after the calls stop.

Dr Windmill said: "Because the moth cleverly tunes its ear to enhance its detection of bats, we must now question whether the bat in turn modifies its calls to avoid detection by the moth. In view of the vast diversity of bat calls, this is only to be expected.

"To date, this phenomenon has not been reported for insects or, in fact, for any other hearing system in the animal kingdom. These findings change our understanding of the co-evolution of bats and moths and have implications for the hearing of many other animals".

It has been known for over 50 years that moths can hear the ultrasonic hunting calls of their nocturnal predator, the bat. Previously it was thought that these ears were only partially sensitive to the sound frequencies commonly used by bats and that bats would make their hunting calls inaudible to moths.........

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December 18, 2006, 9:26 PM CT

Flexibility In Flight Behaviour In Marine Iguanas

Who of us has not dreamt of living on an island? Apparently, island life has certain advantages. This is also true for the marine iguanas. For millions of years they have lived without natural predators. In the course of evolution they have become excessively tame. Hundreds of reptiles doze, spread-eagled, on black lava rocks, soaking up the sun - behaviour that would be unthinkable in an environment with predators, where reptiles are persistently exposed to the threat of being devoured by others.

The absence of predators may lead to adaptations in the behaviour of insular animals. Over a longer evolutionary period, birds for example can lose their ability to fly. This would greatly reduce their ability to escape should new predators appear. In contrast to such "hard wired" traits, however, behavioural patterns should be significantly more flexible. In programmes introducing tame species into the wild, animals are trained to recognise and cope with predators. But in most cases it is very difficult to predict the flexibility in behaviour because little is known about the underlying physiological mechanisms that control behaviour such as flight.

The scientist around Thomas Rodl from the Max Planck Institute for Ornithology visited the Galápagos Islands for field studies from December 2003 until January 2004 and again in March 2005, using the research platform of the Max Planck Society. The islands in the Pacific Ocean continue to be a magnet for evolutionary biologists. Nowhere else is it possible to observe such a variety of different adaptation strategies in such a relatively small number of species. However, it is not only researchers who are drawn to the island; increasingly tourists have also discovered this unique archipelago. In 2005, approx. 126,000 people descended on the island, and the trend is rising. And this causes problems. Not only do tourists disturb the a number of animals living on the Galápagos Islands; they also introduce alien animal and plant species which are causing great damage to local flora and fauna.........

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December 18, 2006, 9:11 PM CT

Borneo's Rainforests

"The more we look the more we find," says Stuart Chapman, WWF International Coordinator of the Heart of Borneo Program. "These discoveries reaffirm Borneo's position as one of the most important centers of biodiversity in the world and why conservation there is so important".

Researchers have discovered at least 52 new species of animals and plants this past year on the island of Borneo. The discoveries, described in a new WWF report, include 30 unique fish species, two tree frog species, 16 ginger species, three tree species and one large-leafed plant species.

Some of the creatures new to science include: a miniature fish, the world's second smallest vertebrate measuring less than a third of an inch in length and found in the highly acidic blackwater peat swamps of the island; six Siamese fighting fish, including one species with a beautiful iridescent blue-green marking; a catfish with protruding teeth and an adhesive belly which allows it to literally stick to rocks; and a tree frog with striking bright green eyes. The new ginger plants more than double the number of the Etlingera species found to date.

Several of these new species were found in the "Heart of Borneo," an 84,000 square mile mountainous region about the size of Kansas that is covered with equatorial rainforest in the center of the island. Large areas of the forest are at risk from destructive logging and expanding rubber, oil palm and pulp plantations. Since 1996, deforestation across Indonesia has increased to an average of 7,700 square miles each year, an area slightly smaller than Vermont. Today only half of Borneo's original forest cover remains.........

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December 18, 2006, 9:05 PM CT

A Laser Link With An Aircraft

Artemis, the European Space Agency Advanced Relay and Technology Mission Satellite, successfully relayed optical laser links from an aircraft in early December. These airborne laser links, established over a distance of 40 000 km during two flights at altitudes of 6000 and 10 000 metres, represent a world first.

The relay was set up through six two-way optical links between a Mystère 20 equipped with the airborne laser optical link LOLA (Liaison Optique Laser Aeroportee) and the SILEX laser link payload on board ARTEMIS in its geostationary orbital position at 36 000 kilometres altitude: a feat equivalent to targeting a golf ball over the distance between Paris and Brussels.

These tests were made by Astrium SAS (France), the prime constructor for both LOLA and SILEX, as part of the airborne laser optical link programme conducted by the DGA (French MoD procurement agency) from its Flight Test Centre at Istres, in the south of France. The ESA ground station of Redu, Belgium, also contributed to this success by managing the Artemis SILEX payload operations.

This clearly demonstrates the feasibility of an optical link between an airborne carrier and a geostationary satellite.

Previously, in November 2001, Artemis made a world premiere by establishing a laser link with the French Earth Observation satellite SPOT-4: imaging data was sent by SPOT-4 using a laser beam as signal carrier to Artemis and from there by radio waves to the ground. This unprecedented link-up between satellites in space was done in the framework of the SILEX development, an innovative payload which provides a laser beam as a data signal carrier.........

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December 18, 2006, 9:02 PM CT

Stars Can Be Strange

As per the "Strange Matter Hypothesis," which gained popularity in the paranormal 1980's, nuclear matter, too, can be strange. The hypothesis suggests that small conglomerations of quarks, the infinitesimally tiny particles that attract by a strong nuclear force to form neutrons and protons in atoms, are the true ground state of matter. The theory has captivated particle physicists worldwide, including one of Washington University's own.

Mark Alford, Ph.D., Washington University in St. Louis assistant professor of physics in Arts & Sciences, and collaborators from MIT and the Lawrence Berkeley National Laboratory and Los Alamos National Laboratory, have used mathematical modeling to discover some properties of theoretical "strange stars," composed entirely of quark matter. Alford and colleagues have observed that under the right conditions the surface of a strange star could fragment into blobs of quark material called "strangelets," forming a rigid halo that contradicts traditional strange star models. This means that collapsed stars' nuclear leftovers, like the famously resplendent Crab Nebula, could be stranger than physicists think.

Alford and colleagues recently published their findings in Physical Review D 73, 114016 (2006). The standard account of the dramatic death of a heavy star is that, after exploding in a supernova that rivals a whole galaxy in brightness, what is left is a "neutron star," a profoundly dense remnant, made mostly of neutrons, with a mass one and a half times that of our sun, crammed into an area with the radius of Saint Louis.........

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December 15, 2006, 4:51 AM CT

Scientists Make Liquid Crystal Discovery

What do milk, paint, ink and liquid crystals have in common? Colloids. Findings of Kent State University scientists indicate that manipulating the size of colloids, micron-sized or nanometer-sized particles, can produce huge changes in the material properties of liquid crystals.

In a recently published article in the scholarly journal Physical Review Letters, the scientists illustrate that when the concentration and size of the colloids and liquid crystals are properly tuned, the systems formed promise a new technique for synthesizing liquid crystals with specific molecular properties. The ferroelectric nanoparticles have a significant impact on the material properties of the liquid crystal host; meanwhile they are stable in the liquid crystals and invisible to naked eye.

Manipulation of these systems also leads to reduction in the amount of power required to run liquid crystal displays, such as computer screens, and could result in creation of a range of different liquid crystal materials for a wide variety of applications.........

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December 13, 2006, 8:01 PM CT

Identification of carbon dioxide receptors in insects

Mosquitoes don't mind morning breath. They use the carbon dioxide people exhale as a way to identify a potential food source. But when they bite, they can pass on a number of dangerous infectious diseases, such as malaria, yellow fever, and West Nile encephalitis. Now, reporting in today's advance online publication in Nature, Leslie Vosshall's laboratory at Rockefeller University has identified the two molecular receptors in fruit flies that help these insects detect carbon dioxide. The findings could prove to be important against the fight against global infectious disease.

"Insects are especially sensitive to carbon dioxide, using it to track food sources and assess their surrounding environment," says Vosshall, Chemers Family Associate Professor and head of the Laboratory of Neurogenetics and Behavior at Rockefeller. "The neurons in insects that respond to carbon dioxide were already known, but the molecular mechanism by which these neurons sense this gas was a mystery".

One protein, called Gr21a, was previously known to be expressed in the carbon dioxide responsive neurons, which are in the antennae of the fruit fly. Since in the fly, chemosensory receptors usually work together as a pair of unrelated proteins, Walton Jones, a former biomedical fellow and first author of the paper, began by looking for other members of the gustatory receptor family, and found that the Gr63a protein was always co-expressed with Gr21a, both in the larva and in the adult fly.........

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December 13, 2006, 6:57 PM CT

Oysters Can Take Heat And Heavy Metals

Pollution is bad for the sea life and so is global warming, but aquatic organisms can be resilient. However, even organisms tough enough to survive one major onslaught may find that a double whammy is more than their molecular biology can take.

A new study has found that even relatively low levels of heavy metal pollution can interfere with the metabolic processes of oysters, and that the effects of the pollution become particularly notable when oyster metabolism is also affected by high seasonal temperatures. The combined effect is strong enough to lead to fatal weakness and disease, adding a fundamental explanation for documented oyster declines in the wild. The effect also reveals an additional impact that warming coastal waters may have on cold-blooded organisms.

Investigating the mechanisms by which the heavy metal cadmium and temperature can each affect metabolic processes in oysters, a new report by a team headed by University of North Carolina at Charlotte ecophysiologist Inna Sokolova finds that both cadmium and temperature independently decrease the efficiency of metabolic processes in the oysters' mitochondria - the place where stored food is turned into the energy living cells run on.

The study also finds that cadmium can cause an increase in the production of reactive oxygen species - dangerous metabolic by-products - while higher temperatures hamper the cellular processes that normally prevent the compounds from causing damage. The findings will appear in the recent issue of the Journal of Experimental Biology.........

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December 13, 2006, 5:04 AM CT

Squid-inspired Design For Underwater Vehicles

Inspired by the sleek and efficient propulsion of squid, jellyfish and other cephalopods, a University of Colorado at Boulder researcher has designed a new generation of compact vortex generators that could make it easier for scientists to maneuver and dock underwater vehicles at low speeds and with greater precision.

In addition, the technology - seemingly inspired by the plots of two classic sci-fi films - may soon allow doctors to guide tiny capsules with jet thrusters through the human digestive tract, enabling them to diagnose disease and dispense medications.

Kamran Mohseni, an assistant professor of aerospace engineering sciences, will present these and other details at the American Geophysical Union's annual fall meeting Dec. 11-15 in San Francisco. A global network of scientists, the AGU describes its mission as the advancement of terrestrial, atmospheric and space research aimed at benefiting humanity.

"Reliable docking mechanisms are essential for the operation of underwater vehicles, especially in harsh environments," Mohseni said. "We set out to resolve the trade off that many researchers settle for, which is a faster, but less precise, vehicle or a boxier one that is not as fast and more difficult to transport to work locations".

Manned and unmanned underwater vehicles enable scientific researchers to explore ecosystems around the globe, from undersea volcanoes near Hawaii to the frigid depths beneath pack ice in the North and South poles. However, while the torpedo shape of some underwater vehicles ensures rapid deployment and high cruising speeds with minimal energy, their hydrodynamic design makes them more difficult to maneuver or dock at low speeds and in tight spaces, or to hover in precise locations.........

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December 13, 2006, 4:37 AM CT

Lightning Fires Help Preserve Oak Forests

Oak forests may be approaching extinction but lightning fires may play a vital role in their regeneration, according to Case Western Reserve University biologists.

Paul Drewa, assistant professor in Case's biology department, and graduate student Sheryl Petersen, suspect that these kinds of fires may provide a natural mechanism to deter encroachment of shade tolerant hardwoods, especially red maples that are crowding out oaks and other plants on the ground floors of numerous forests throughout the eastern United States.

In an article for the April-recent issue of the Journal of the Torrey Botanical Society, the researchers examined regional weather patterns to see if environmental conditions exist for the occurrence of lightning fires in Appalachian forests of Adams and Pike Counties in southern Ohio.

The likelihood of lightning fires increases through the summer when the frequency of lightning strikes reaches its greatest peak in late August, coinciding with dry environmental conditions," said Drewa.

Drewa and Petersen also found that from 1993 to 2005, 29 lightning fires were reported in Ohio's fire protection areas, with 70 percent of those occurring during the summer.

"Human alterations to the natural fire regime, especially decades of fire suppression, have changed oak-dominated ecosystems in southern Ohio and throughout the eastern US," reported.........

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