October 16, 2006, 9:43 PM CT

Tiger population declining

Experts say that illegal wildlife trade ranks among the most lucrative rackets in the world -- in the range of such enterprises as narcotics and arms smuggling. The international police organization Interpol estimates the annual turnover in wildlife trade is over $6 billion.

Tigers (Panthera tigris) are mammals of the Felidae family and one of four "big cats" in the Panthera genus. They are superpredators and the largest and most powerful living cat species in the world[2][3]. The Royal Bengal Tiger is the most common subspecies of tiger, constituting approximately 80% of the entire tiger population, and is found in the Indian subcontinent. The tiger's beautiful blend of grace and ferocity led the legendary author and conservationist, Jim Corbett to remark - "The Tiger is a large hearted gentleman with boundless courage".

Most tigers live in forests or grasslands, for which their camouflage is ideally suited, and where it is easy to hunt prey that is faster or more agile. Among the big cats, only the tiger and jaguar are strong swimmers; tigers are often found bathing in ponds, lakes, and rivers. Tigers hunt alone and eat primarily medium to large sized herbivores such as deer, wild pigs, gaur and water buffalo. However, they also take smaller prey on occasion.........

Posted by: Ashley      Permalink         Source

October 15, 2006, 8:52 PM CT

Mimicing Lotus Leaves For Self-cleaning PV Arrays

Scientists at the Georgia Institute of Technology are mimicking one of Nature's best non-stick surfaces to help create more reliable electric transmission systems, photovoltaic arrays that retain their efficiency, MEMS structures unaffected by water and improved biocompatible surfaces able to prevent cells from adhering to implanted medical devices.

Based on a collaboration of materials researchers and chemical engineers, the research aims to duplicate the self-cleaning surfaces of the lotus plant, which grows in waterways of Asia. Despite growing in muddy conditions, the leaves and flowers remain clean because their surfaces are composed of micron- and nano-scale structures that - along with a waxy coating - prevent dirt and water from adhering. Despite their unusual surface properties, the rough surfaces allow photosynthesis to continue in the leaves.

"When rain hits the leaves of the lotus plant, it simply beads up," noted C.P. Wong, a Regents Professor in Georgia Tech's School of Materials Science and Engineering. "When the leaves are also tilted at a small angle, the beads of water run off instantaneously. While the water is rolling off, it carries away any dirt on the surface".

The self-cleaning action of the lotus plant has intrigued scientists for decades, and recent studies done by scientists in several different groups have demonstrated the reasons behind the plant's unique abilities.........

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October 15, 2006, 8:29 PM CT

Marine Life Stirs Ocean

Oceanographers worldwide pay close attention to phytoplankton and with good reason. The microscopic plants that form the vast foundation of the marine food chain generate a staggering amount of power, and now a groundbreaking study led by Florida State University has calculated just how much -- about five times the annual total power consumption of the human world.

Physical and biological oceanographers led by FSU Professor William Dewar put the yearly amount of chemical power stored by phytoplankton in the form of new organic matter at roughly 63 terawatts, and that's a lot of juice: Just one terawatt equals a trillion watts. In 2001, humans collectively consumed a comparatively measly 13.5 terawatts.

What's more, their study observed that the marine biosphere -- the chain of sea life anchored by phytoplankton -- invests around one percent (1 terawatt) of its chemical power fortune in mechanical energy, which is manifested in the swimming motions of hungry ocean swimmers ranging from whales and fish to shrimp and krill. Those swimming motions mix the water much as cream is stirred into coffee by swiping a spoon through it.

And the sum of all that phytoplankton-fueled stirring may equal climate control.

"By interpreting existing data in a different way, we have predicted theoretically that the amount of mixing caused by ocean swimmers is comparable to the deep ocean mixing caused by the wind blowing on the ocean surface and the effects of the tides," Dewar said.........

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October 12, 2006, 7:55 PM CT

Plants Become Air Quality Detectives

What does a garden have to do with the chemistry of the atmosphere and air quality? One of the newest exhibits at NASA Goddard's Visitor Center, Greenbelt, Md., is a project related to NASA's Aura satellite. Aura is currently studying atmospheric chemistry and air pollution from space. The new Aura Ozone Monitoring Garden is used to study air quality from the ground by seeing how ozone in the air damages the leaves of certain plants.

During the summer months of intense sunlight, the air surrounding major urban areas undergoes dramatic changes. Ozone is formed when chemical pollutants that are by-products of human activities such as biomass burning and the combustion of fossil fuels react in the presence of sunlight. Ozone is a molecule that at ground level is a harmful air pollutant in high or prolonged concentrations.

Ozone tolerance among plants and people varies. According to research at the Great Smoky Mountain National Park and elsewhere, many common species of plants are sensitive to high concentrations of ozone. The Aura Ozone Monitoring Garden features plants that are known to be ozone sensitive, such as white dogwood (Cornus florida) and cardinal flower (Lobelia cardinalis).

Many of the plants that have been found to be ozone sensitive thrive in a wide range of the temperate environments within the continental United States. Aura education personnel at Goddard chose a variety of plants for the garden that represent different growing environments, from agriculture to horticulture.........

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October 12, 2006, 5:16 AM CT

In Wake Of Horse Slaughter Bill

The American Horse Slaughter Prevention Act, making its way from the U.S. House to the Senate, could leave thousands of horses with no final resting ground.

Composting may be an environmentally friendly option that fits in the "circle of life" frame of mind and may be less emotional, two area researchers said.

On Sept. 7 the House approved the Act, which bans the slaughter of horses for human consumption by a vote of 263-146. The Senate has yet to schedule the issue for consideration.

Approximately 90,000 horses, or 1 percent of the U.S. horse population, is slaughtered annually, said Dr. Lance Baker, West Texas A&M University associate professor of animal science.

"If they don't go to slaughter, they will have to go somewhere else," Baker said.

The options for dealing with a carcass are burial, rendering, landfill disposal, incineration, composting or bio-digesting, he said. Many of these are costly, and a horse owner often has to pay to put the horse down and for its disposal, instead of getting money for the animal.

Large-carcass composting is a growing and accepted practice among feedyards and dairies, said Dr. Brent Auvermann, a Texas Agricultural Experiment Station agricultural engineer who has researched the process for about five years.........

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October 11, 2006, 5:13 AM CT

Uncovering Mysteries Of Memory

Keeping track of one set of keys is difficult enough, but imagine having to remember the locations of thousands of sets of keys. Do you use landmarks to remember where you put them? Do you have a mental map of their locations?

Scientists at the University of New Hampshire hope to learn more about memory and its evolution by studying the Clark's nutcracker, a bird with a particularly challenging task: remembering where it buried its supply of food for winter in a 15-mile area. Like many animals preparing for the winter, every fall the Clark's nutcracker spends several weeks gathering food stores. What makes it unique is that it harvests more than 30,000 pine nuts, buries them in up to 5,000 caches, and then relies almost solely on its memory of where those caches are located to survive through winter.

Brett Gibson, a scientist studying animal behavior, began studying Clark's nutcrackers in graduate school and is continuing his research into memory and the behavior of nutcrackers as an assistant professor in UNH's psychology department.

"Nutcrackers are almost exclusively dependent upon cache recovery for their survival so if they don't remember where they've made those caches, then they are in trouble," Gibson says. "During winter, their cache locations are covered with snow so many of the small local features in the landscape during fall are no longer available to them. What's clear is that they are using spatial memory to recover these caches. They are remembering these caches based on landmarks and other features of the terrain".........

Posted by: Ashley      Permalink         Source

October 11, 2006, 4:58 AM CT

Some Butterflies Travel Farther, Reproduce Faster

Researchers have uncovered physiological differences among female Glanville fritillary butterflies that allows some to move away from their birth place and establish new colonies. These venturesome butterflies are stronger fliers and reproduce more quickly compared to their less mobile female relatives.

The study is a window to how genetic differences influence behavior and how the environment influences genetic change by favoring individuals with certain traits, said lead author Howard W. Fescemyer. The new study found significant physiological differences that may account for the more adventuresome behavior of certain of the females.

The work is important because human activity is disrupting many animal habitats, forcing more and more species to do what the fritillary has long done in its naturally fragmented environment. Scientists want to know how this fragmentation influences a species' evolution.

"We may be selecting for genes that enhance the dispersal or migratory capability of animals when we fragment the landscape," Fescemyer said. The animals best able to migrate are more likely to survive and reproduce. "What we learn could apply to any organism that has to move to find food," he added.



land Islands are natural laboratory........

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October 8, 2006, 6:49 PM CT

Rearing An Army To Save Wheat

With wheat stem sawfly natural enemies in demand, Montana State University entomologists are investigating ways of increasing their availability.

This fall, the entomologists are concluding a two-year study that involved mass-rearing parasitic wasps that attack wheat stem sawfly larvae that tunnel the interior of developing wheat plants. The team includes entomologists David Weaver, master's graduate Godshen Pallipparambil-Robert and undergraduate Melissa Frazier of Kalispell.

Pallipparambil-Robert's work, as part of his completed master's degree, used large cages placed over wheat at the Post Agronomy Farm west of Bozeman. He deliberately infested the enclosed wheat with wheat stem sawflies, and then introduced the parasitic wasps. His research explored whether supplemental food provided as nectar from flowering plants or as honey water increases the number of parasitic wasps produced in each cage. Another part of his thesis project examined whether using special ultraviolet and visible light-transmitting windows increases the number of parasites.

"After two years, the research shows that the added light consistently causes small increases in the number of parasitic wasps, while the food supply is probably not important in these mass-rearing cages, because the parasitoids were added in large numbers, and attacked the available sawflies before the need to feed may have become critical " Weaver said. At lower parasitoid densities, supplemental food might be much more important, and research from other systems suggests that this is definitely true in natural settings. However, the goal of the research is to find ways to increase the supply of parasitoids from a controlled system to Montana wheat growers.........

Posted by: Jessica      Permalink         Source

October 4, 2006, 10:19 PM CT

Loss Of Trout Habitat In The Southern Appalachians

USDA Forest Service (FS) research projects that between 53 and 97 percent of natural trout populations in the Southern Appalachians could disappear due to the warmer temperatures predicted under two different global climate circulation models. In an article published October 2 in the online version of the Transactions of the American Fisheries Society, Patricia Flebbe, research biologist at the FS Southern Research Station unit in Blacksburg, VA, maps out trout habitat in a future, warmer climate.

The three species of trout that live in the Southern Appalachians--native brook and the introduced rainbow and brown trout --all require relatively low stream temperatures to survive. Average air temperature in the United States has increased by about 0.6 C (1o F) over the last 100 years, and is projected to increase 3 to 5C (5.4 to 9o F) over the next century, causing a corresponding warming of stream temperatures.

"Trout species in the Southern Appalachians are already at the southern limits of their ranges," says Flebbe. "If temperatures warm as much as predicted, trout habitat in the region will definitely shrink".

To estimate trout habitat in relation to higher temperatures, Flebbe and fellow scientists Laura Roghair from the Virginia Tech Conservation Management Institute and former FS employee Jennifer Bruggink produced a regional map of wild trout habitat based on information from stream samples, expert knowledge, and suitable land cover. They then developed a model that uses elevation and latitude as surrogates for temperature, producing spatially explicit information about how much trout habitat will be left as temperatures rise over the next 100 years.........

Posted by: Ashley      Permalink         Source

October 4, 2006, 8:23 PM CT

Light On Evolution Of Life Cycles

In the history of life on earth, one intriguing mystery is how plants made the transition from water to land and then went on to diversify into the array of vegetation we see today, from simple mosses and liverworts to towering redwoods.

A research team led by University of Michigan evolutionary biologist Yin-Long Qiu has new findings that help resolve long-debated questions about the origin and evolution of land plants. The work will be published online this week in the Proceedings of the National Academy of Sciences.

Two major steps kicked off the chain of events that helped land plants prosper, forming the basis for modern land-based ecosystems and fundamentally altering the course of evolution of life on earth, said Qiu. The first step was the colonization of land by descendents of aquatic plants known as charophyte algae. That event opened up a vast new world where the sun's intensity was undiminished by passage through water and where carbon dioxide-another essential ingredient for plant life-was abundant.

The second event was a key change in plant life cycles. Plants exhibit a phenomenon known as alternation of generations, in which two alternating forms with different amounts of DNA make up a complete life cycle. One form, known as a sporophyte, produces spores, which grow into individuals of the other form, called gametophytes. Gametophytes produce gametes-eggs and sperm-which unite to form a fertilized egg capable of becoming a new sporophyte, thus completing a life cycle. While all plants exhibit alternation of generations, some spend most of their life cycle as sporophytes, and others spend more time in the gametophyte phase.........

Posted by: Jessica      Permalink         Source