July 25, 2006, 8:09 PM CT

Chinese Tallow Tree For Building

A preliminary study by USDA FS Southern Research Station (SRS) scientists and cooperators shows that Chinese tallow tree, a nonnative invasive plant in the southeastern United States, holds promise as a material for bio-based composite building panels. In a technical note in the June 2006 issue of Forest Products Journal, the scientists report positive results from tests on 3 different types of panels made from Chinese tallow tree.

Because Chinese tallow tree grows rapidly, has seeds rich in oils, abundant flowers, and colorful fall foliage, it has been widely planted both as an ornamental and a crop across the Southeast. Now considered a noxious pest by the USDA Natural Resources Conservation Service, the plant has become a serious problem in east Texas, Louisiana, and Mississippi, where is establishes dense stands that quickly out compete most other tree species.

The rapid expansion of the Chinese tallow tree into Southern forests has lead to a call to investigate its possible uses in the forest products industry. "The low density and light color of the wood make it an ideal candidate for producing composite panels, particularly oriented strandboard, medium density fiberboard and particleboard," said Les Groom, project leader for the SRS Utilization of Southern Forest Resources unit in Pineville, LA, and co-author of the article with SRS research scientist Tom Eberhardt and technologist Chung Hse.........

Posted by: Erica      Permalink         Source

July 24, 2006, 6:52 AM CT

Life on Earth More Than 3.8 Billion Years Ago

Ten years ago, an international team of scientists reported evidence, in a controversial cover story in the journal Nature, that life on Earth began more than 3.8 billion years ago-400 million years earlier than previously thought. A UCLA professor who was not part of that team and two of the original authors will report in late July that the evidence is stronger than ever.

Craig E. Manning, lead author of the new study and a professor of geology and geochemistry in the UCLA Department of Earth and Space Sciences, painstakingly mapped an area on Akilia Island in West Greenland where ancient rocks were discovered that may preserve carbon-isotope evidence for life at the time of their formation. Manning and his co-authors-T. Mark Harrison, a UCLA professor of geochemistry, director of UCLA's Institute of Geophysics and Planetary Physics, and University Professor at the Australian National University; and Stephen J. Mojzsis, assistant professor of geological sciences at the University of Colorado, Boulder-conducted new geologic and geochemical analysis on these rocks. Their findings would be reported in the new issue of the American Journal of Science. Harrison and Mojzsis were co-authors on the Nov. 7, 1996, study in Nature.

"This paper shows, with far greater confidence than we ever had before, that these rocks are older than 3.8 billion years," said Manning, who has conducted extensive research in Greenland. "We have shown that the rocks are appropriate for hosting life.........

Posted by: Kelly      Permalink         Source

July 22, 2006, 11:16 PM CT

Yeast In Space

Far above the heads of Earthlings, arrays of single-cell creatures are circling Earth in nanostructures.

The sample devices are riding on the International Space Station (courtesy of Sandia National Laboratories and the University of New Mexico, NASA and US Air Force) to test whether nanostructures whose formations were directed by yeast and other single cells can create more secure homes for their occupants - even in the vacuum and radiation of outer space - than those created by more standard chemical procedures.

Sandia is a National Nuclear Security Administration laboratory.

"Cheap, tiny, and very lightweight sensors of chemical or biological agents could be made from long-lived cells that require no upkeep, yet sense and then communicate effectively with each other and their external environment," says former UNM graduate student and Sandia consultant Helen Baca, lead author on the paper. Baca was advised by Sandia Fellow and UNM professor of chemical engineering, molecular genetics & microbiology Jeff Brinker.

Groups of such long-lived cells may also serve as models to investigate how tuberculosis bacteria survive long periods of dormancy within human bodies.

En masse, they also may be used to generate signals to repel harmful bacteria from the surfaces of surgical tools like catheters.........

Posted by: Erica      Permalink

July 13, 2006, 8:58 PM CT

Genetic Origin Of California Wild Radish

The California wild radish is descended from hybrids between two species: cultivated radish and the weed, jointed charlock.
Credit: S. Hegde, UCR.
Researchers studying the genetic makeup of wild radishes in California have determined that the California wild radish is descended from hybrids between two species: cultivated radish and the weed, jointed charlock. The hybrid-derived plants apparently have completely eliminated the ancestral species from California, the scientists report.

The discovery is significant because the parental species were replaced by a single, stable hybrid lineage in less than 100 years, an extremely short interval in evolution.

The scientists published their findings in the recent issue of Evolution. Next week's issue of the journal Nature highlights their research.

"The documented instances of extinction by hybridization in which both parents are replaced by the hybrid are rare," said Subray G. Hegde, the lead author of the paper and a postgraduate research geneticist who, in 2001, joined the research group of Norman C. Ellstrand, professor of genetics in UCR's Department of Botany and Plant Sciences. "What we've shown is that the extinction of a species by this process can occur very rapidly. We need to recognize the lesson this teaches us for conservation: if we are to save organisms from extinction, we need to make sound decisions fast".

Both the cultivated radish and jointed charlock were introduced to California more than 100 years ago. While the cultivated variety, found in grocery stores, bears pink, purple and white flowers and has a swollen root, the weed bears yellow flowers (occasionally also white) and has a slender root.........

Posted by: Erica      Permalink         Source

July 11, 2006, 8:46 PM CT

Preserving a Wild West

When Americans think of the Wild West, we often conjure cowboys and ranchlands, grizzly bears and mountains, or a great plain where the buffalo once roamed. But Dr. Joel Berger, senior scientist with the Wildlife Conservation Society's North America Program, thinks of pronghorn. As the fastest land animal in North America, these lithe antelope migrate annually across tremendous distances, at speeds of up to 55 miles per hour.

Given the significant size of the pronghorn population-which numbers almost half a million in Wyoming alone-their plight has not inspired great sympathy. But this distinctly American species has become a casualty of one of the most provocative issues of our time: the national energy crisis. As Western lands become increasingly subject to development, the conservation of Rocky Mountain wildlife is losing ground-literally.

Berger and his team in the WCS Teton Field Office, which includes researchers Dr. Kim Murray Berger and Dr. Jon Beckmann, are working on two projects to carve out a home for pronghorn in the face of the impending human footprint. One is the creation of a permanently protected migration corridor for the antelope. This ambitious project would conserve the most extensive trail of its kind in the Western Hemisphere, and one that has been in use since the end of the last Ice Age. The scientists' other project is a study on how natural gas development in the Rockies influences the pronghorn that winter there. Shell Exploration & Production Company, Ultra Resources, Inc., and other energy groups are funding this five-year investigation, an important collaboration between the industry and conservation sectors.........

Posted by: Kelly      Permalink         Source

July 11, 2006, 7:18 AM CT

Science Captures The Essence Of Fruit

New research designed to build scientific understanding of fruit genes could revolutionise the way foods, cosmetics and perfumes are created.

Scientists at New Zealand-based life sciences company HortResearch say they have fine-tuned the science of gene discovery to such a degree that they can now accurately determine which genes create the individual flavours and fragrances found in fruits and flowers.

Combined with traditional biofermentation techniques - the same process that helps bread rise or grape juice to become wine - this means that it should be possible for the natural tastes and aromas of fruit to be recreated.

As per HortResearch Industrial Biotechnology scientist Dr Richard Newcomb, that's exciting news for the world's food, perfume and cosmetic producers, who have for years sought synthetic solutions to mimic nature's flavours and fragrances in products ranging from ice cream to shampoo.

"While manufacturers have largely been successful in copying natural tastes and scents, they generally do so either through a chemical synthesis process or extraction from harvested raw ingredients.

"Neither approach is ideal. Chemical synthesis requires heat and pressure, so is reliant on increasingly expensive and polluting fossil fuels for energy. What's more, chemical synthesis can never truly recreate nature; the flavour or fragrance will typically be slightly different to that found naturally in fruits and flowers.........

Posted by: Erica      Permalink         Source

July 7, 2006, 9:20 PM CT

Corals Switch Skeleton

Leopards may not be able to change their spots, but corals can change their skeletons, building them out of different minerals depending on the chemical composition of the seawater around them.

That's the startling conclusion drawn by a Johns Hopkins University marine geologist, writing in the recent issue of the journal Geology.

Postdoctoral fellow Justin Ries and his collaborators say this is the first known case of an animal altering the composition of its skeleton in response to change in its physical environment. The aquatic animal's sensitivity to such changes poses questions about its evolutionary history, as well as the future of the ecologically important coral reefs that it builds, Ries said, particularly at a time when seawater is changing in response to global warming and the buildup of carbon dioxide in the atmosphere.

A 2005 Ph.D. graduate of Johns Hopkins, Ries collaborated on the research with his dissertation advisors, Steven M. Stanley (now of the University of Hawaii) and Lawrence A. Hardie, professor in the Morton K. Blaustein Department of Earth and Planetary Sciences at Johns Hopkins.

Reefs are large underwater structures of coral skeletons, made from calcium carbonate secreted by generation after generation of tiny coral polyps over sometimes millions of years of coral growth in the same location. The team showed that corals can switch from using aragonite to another mineral, calcite, in making the calcium carbonate. They make that switch in response to decreases in the ratio of magnesium to calcium in seawater, Ries said. That ratio has changed dramatically over geologic time.........

Posted by: Kelly      Permalink         Source

July 7, 2006, 9:06 PM CT

Voluntary Closures Of High-seas Deepwater Trawling

In a global first, four major fishing companies announced recently a voluntary halt to trawling in eleven deep-sea areas of the southern Indian Ocean. This will protect and conserve the bottom of the sea floor, or benthos, associated fish fauna and related biodiversity in one of the largest marine protected area enclosures ever.

"By setting aside an area almost equal to Australia's Great Barrier Reef National Park, these businesses are sending a clear signal that they want to keep fish on people's plates for generations to come," commented Graham Patchell, a scientist with the newly formed Southern Indian Ocean Deepwater Fishers' Association (SIODFA), which represents four companies - Austral Fisheries Pty Ltd (Australia), Bel Ocean II Ltd (Mauritius), Sealord Group (New Zealand) and TransNamibia Fishing Pty Ltd (Namibia), the main trawling operators in this area.

Using the scientific knowledge gathered over a decade of activity in the Indian Ocean and in consultation with staff of the Fisheries Department of the United Nations Food and Agriculture Organization (FAO), SIODFA have delimited 309 000 km2 of ocean floor in eleven separate benthic protected areas where their vessels will no longer fish. The combined zones have an area approximately the size of Norway. To verify compliance with these self-adopted restrictions, the companies will track their vessels' locations and activities via a special satellite monitoring system.........

Posted by: Kelly      Permalink         Source

July 4, 2006, 9:51 AM CT

Solvng Plant Growth Hormone Enigma

Gardeners and farmers have used the plant hormone auxin for decades, but how plants produce and distribute auxin has been a long-standing mystery. Now scientists at the University of California, San Diego have found the solution, which has valuable applications in agriculture.

The study, reported in the July 1 issue of the journal Genes and Development, describes the discovery of a whole family of auxin genes, and shows that each gene is switched on at a distinct location in the plant. Contrary to the current thinking in the field, the research shows that the patterns in which auxin is produced in the plant influence development, a finding that can be applied to improving crops.

"The auxin field dates back to Charles Darwin, who first reported that plants produced a substance that made them bend toward light," said Yunde Zhao, an assistant professor of biology at UCSD. "But until now, the auxin genes have been elusive. Our discovery of these genes and the locations where auxin is produced in the plant can be applied to agricultural problems, such as how to make seedless fruit or plants with stronger stems".

Applying auxin to plants can have a number of different effects. For example, it can promote root development in cuttings, stimulate fruit development in the absence of fertilization or, in excess, kill weeds. However, this study is the first to show what happens in a plant when auxin production is turned off.........

Posted by: Erica      Permalink         Source

June 28, 2006, 0:28 AM CT

Symbiotic Fungus Does Not Depend On Fungus-farming Ants

Fungus-farming ants around the world cultivate essentially the same fungus and are not as critical to the reproduction of the fungi as previously believed, biologists at The University of Texas at Austin have discovered.

Fungus-farming ants are dependent on cultivating fungus gardens for food, and it has been widely believed the fungi also evolved dependence on the ants for their dispersal and reproduction. When young ant queens establish new colonies, they take a start-up crop of fungi with them from their parental garden.

Graduate student Alexander Mikheyev and Dr. Ulrich Mueller, professor of integrative biology, have now found that the fungi reproduce sexually and disperse widely without the aid of their ant farmers.

Different genera of the ants, it turns out, are essentially cultivating the same fungus across wide geographical areas.

The scientists' finding provides a new perspective on coevolutionary processes. Coevolution, like that between honeybees and the flowers they pollinate, occurs when two or more species influence each other's evolution over time. Mikheyev says that two species don't necessary need to have a very specific, one-to-one relationship in order to coevolve.

"This shows that coevolution can proceed without specificity at the species level," said Mikheyev. "It has been believed that mutualistic interactions, as well as parasitic ones, are very specific and one-to-one. We are beginning to realize that this is not necessary for long-term coevolutionary stability, with the leaf-cutting ants being a dramatic example."........

Posted by: Erica      Permalink         Source