December 13, 2006, 5:03 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 researchers 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, particularly in harsh environments," Mohseni said. "We set out to resolve the trade off that a number of scientists 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".........

Posted by: Aaron      Permalink         Source

December 13, 2006, 4:36 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, as per 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, particularly 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 scientists 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 observed 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, particularly decades of fire suppression, have changed oak-dominated ecosystems in southern Ohio and throughout the eastern US," reported.........

Posted by: Erica      Permalink         Source

December 12, 2006, 4:48 AM CT

'ZIP Code' Spurs Cargo Transport in Neurons

For the first time, researchers have identified a peptide that can spur cargo transport in nerve cells, a discovery that could help scientists better understand nerve cell function and test possible therapies for neurodegenerative diseases.

Elaine Bearer, a professor at Brown Medical School, led the research, which was conducted at the MBL (Marine Biological Laboratory) in Woods Hole, Mass., where Bearer was a Dart Scholar and is a Whitman investigator. Published in the Proceedings of the National Academy of Sciences online early edition, the research shows that a peptide, or protein bit, can hitch biological material onto molecular motor machinery, acting as a "ZIP Code" that directs the shipment to the synapse.

The peptide comes from amyloid precursor protein, or APP, a principal component of plaques found in the brains of people with Alzheimer's disease. Scientists have long known that APP can break down and form these plaques and that mutations in this protein lead to early onset of Alzheimer's disease. Until now, however, little was understood about the function of APP in healthy nerve cells.

The research also sheds light on the complex intracellular transport system inside nerve cells. This transport system is critical to nervous system function, bringing proteins and RNA from the cell body down a neuron's spindly axon to the synapse, the major site of information exchange and storage in the nervous system. Without this precious cargo, neurons can't communicate. Memories can't be made. Learning can't take place. And neurons die.........

Posted by: Kelly      Permalink         Source

December 11, 2006, 9:42 PM CT

Agricultural Production In Great Lakes

The Netherlands Government is launching a project to promote peace and environmental stability by improving soil health, intensifying farm production, and increasing trade in one of the world's poorest areas: the Great Lakes Region of Central Africa.

The highest population density in Africa is in the Great Lakes Region: Rwanda, Burundi, Uganda, western Tanzania, and the eastern Democratic Republic of the Congo.

"The Great Lakes region already has far more people than its fragile soils can support," says Dr. Amit Roy, CEO of IFDC, An International Center for Soil Fertility and Agricultural Development. IFDC will implement the 5-year project.

"The region faces perpetual crises of poverty, social instability, war, and environmental degradation. The situation is rapidly worsening as deforestation intensifies and its soils are starved of nutrients".

Tiny Rwanda is typical. More than 340 persons are packed into each square kilometer, and population is growing by almost 3% annually. Almost all of Rwanda's population are subsistence farmers. Using existing technology, food production can be increased only by clearing and farming the ecologically important wetlands or, worse, the last relicts of parks and reserves, including habitats of mountain gorillas and other endangered wildlife and plants.........

Posted by: Erica      Permalink         Source

December 11, 2006, 9:36 PM CT

Plant One Tree And Save The Earth

Can planting a tree stop the sea level from rising, the ice caps from melting and hurricanes from intensifying?

A new study says that it depends on where the trees are planted. It cautions that new forests in mid- to high-latitude locations could actually create a net warming. It also confirms the notion that planting more trees in tropical rainforests could help slow global warming worldwide.

In the first study to investigate the combined climate and carbon-cycle effects of large-scale deforestation in a fully interactive three-dimensional climate-carbon model, researchers from Lawrence Livermore National Laboratory, Carnegie Institution and Universite Montpellier II observed that global forests actually produce a net warming of the planet.

The study provides a holistic view of the deforestation issue. "This is the first comprehensive assessment of the deforestation problem" said Govindasamy Bala, lead author of the research that will be presented on Dec. 15 at the American Geophysical Society annual meeting in San Francisco.

The models calculated the carbon/climate interactions and took into account the physical climate effect and the partitioning of the carbon dioxide release from deforestation among land, atmosphere and ocean.

Forests affect climate in three different ways: they absorb the greenhouse gas carbon dioxide from the atmosphere and help to keep the planet cool; they evaporate water to the atmosphere and increase cloudiness, which also helps keep the planet cool; and they are dark and absorb a lot of sunlight, warming the Earth. Climate change mitigation strategies that promote planting trees have taken only the first effect into account.........

Posted by: Erica      Permalink         Source

December 11, 2006, 9:22 PM CT

Upsetting Notions about Honey Bees

Genetic research, based on information from the recently released honey bee genome, has toppled some long-held beliefs about the honey bee that colonized Europe and the U.S.

According to research published recently in Science, an international professional journal published by the American Association for the Advancement of Science, the four most common subspecies of honey bee originated in Africa and entered Europe in two separate migrations, said Dr. Spencer Johnston, entomologist with the Texas Agricultural Experiment Station and one of the authors of the article.

A large number of different bee species exist in Asia, where it had long been thought the honey bee originated, Johnston said.

"Their origin in Africa was suggested in other studies, but our result shows it dramatically to be true," he said.

Taking genetic information from the honey bee genome sequencing effort, researchers from Texas A&M University, University of Illinois, Cornell University, Washington State University, University of Kansas and the University of California-Irvine, and one private producer traced the genealogy of honey bees. Two branches originate in Africa.

The honey bee is not native to North America; it was introduced from Europe for honey production in the early 1600s, Johnston said. Subspecies were introduced from Italy in 1859, and later from Spain, Portugal and elsewhere.........

Posted by: Kelly      Permalink         Source

December 11, 2006, 4:47 AM CT

Finding Mind-body Connection With Fruit Fly Sex

Male fruit flies are smaller and darker than female flies. The hair-like bristles on their forelegs are shorter, thicker. Their sexual equipment, of course, is different, too.

"Doublesex" is the gene largely responsible for these body differences. Doublesex, new research shows, is responsible for behavior differences as well. The finding, made by Brown University biologists, debunks the notion that sexual mind and sexual body are built by separate sets of genes. Rather, scientists found, doublesex acts in concert with the gene "fruitless" to establish the wing-shaking come-ons and flirtatious flights that mark male and female fly courtship.

Results are published in Nature Genetics.

"What we found here, and what is becoming increasingly clear in the field, is that genetic interactions that influence behavior are more complex than we thought," said Michael McKeown, a Brown biologist who led the research. "In the case of sex-differences in flies, there isn't a simple two-track genetic system - one that shapes body and one that shapes behavior. Doublesex and fruitless act together to help regulate behavior in the context of other developmental genes".

How genes contribute to behavior, from aggression to alcoholism, is a growing and contentious area of biology. For more than a decade, McKeown has been steeped in the science, using the fruit fly as a model to understand how genes build a nervous system that, in turn, controls complex behaviors. Since humans and flies have thousands of genes in common, the work can shine a light on the biological roots of human behavior. For example, McKeown recently helped discover a genetic mutation that causes flies to develop symptoms similar to Alzheimer's disease - a gene very similar to one found in humans.........

Posted by: Janet      Permalink         Source

December 11, 2006, 4:42 AM CT

Structure of DNA-Doctoring Protein Complex

More than half of the human genome is made up of bits of mobile DNA, which can travel inside the body and insert genes into the chromosomes of target cells. This DNA doctoring not only shapes species over time, it also spreads antibiotic resistance and is used by bacteria that spread Lyme disease and by viruses associated with certain forms of cancer.

Last year in Nature, researchers working in the Brown University lab of Arthur Landy and the Harvard Medical School lab of Thomas Ellenberger announced they had solved the structure of ?-integrase (?-Int), the protein "surgeon" that allows mobile DNA to cut into a chromosome, insert its own genes, and then sew the chromosome back up. That work was conducted using the lambda virus, which infects Escherichia coli (E. coli) bacteria and serves as a model that researchers use to understand mobile DNA.

Now researchers in the Landy lab have solved the structure of a DNA-protein complex that acts as a team of "nurses," aiding ?-Int during this snip-and-solder procedure known as site-specific recombination. The structure is a three-dimensional representation of the DNA within this complex. Pictured on the cover of the Nov. 17, 2006, journal Molecular Cell, it looks like DNA dressed for a party, a double helix decked with clumps of curly, colorful ribbon. By solving this structure, researchers now know how these six proteins interact with each other and fold DNA during site-specific recombination.........

Posted by: Janet      Permalink         Source

December 10, 2006, 5:39 PM CT

Unusual Deep Sea Animals

We are all familiar with dolphins, whales and sharks; we know what tuna and snapper look like, but what about some less familiar fish such as lizardfish, giant squid, or blind eels? There are so a number of lesser known animals in the depths of the ocean that we hear little or nothing about most times, it is interesting to investigate a few of these creatures and understand them a little more.

The first on our list of deep sea creatures is the fangtooth fish. This fish is one of the most evil looking ocean predators. It lives in the deep ocean and catches its prey by luring them in with glowing light organs called photophores. In such a dark abyss, fish are attracted to the light put off by the organ and once they are close enough the fangtooth fish catches them in his numerous large teeth. He looks like an underwater vampire.

Another carnivorous sea animal is the deep-sea lizardfish. These interesting fish look almost like a short snake in water. Their mouths are covered with harpoon-tipped teeth that grasp their prey and don't let go, similar to a fish hook. These teeth are hinged so that they can flattened down when prey is going in and stand up when resisting. They don't even need to actively swallow; the struggling prey just ratchets itself inside. With their glowing yellow eyes, the lizardfish is a wonder to behold.........

Posted by: Kelly      Permalink         Source

December 10, 2006, 5:46 PM CT

Amazing Forms Of Life

I was reading the news about deep-sea creatures found in the Atlantic Ocean, and thought I might share some of this with you. The report speaks about mysterious creatures that are found in the deep sea. In one place the researchers found Atlantic shrimp, which was living around a vent that was releasing water heated to 765 degree Fahrenheit!

An underwater peak in the Coral Sea was home to a type of shrimp thought to have gone extinct 50 million years ago.

More than 3 miles beneath the Sargasso Sea, in the Atlantic, researchers collected a dozen new species eating each other or living on organic material that drifts down from above.

"Animals seem to have found a way to make a living just about everywhere," said Jesse Ausubel of the Sloan Foundation, discussing the findings of year six of the census of marine life.

Added Ron O'Dor, a senior scientist with the census: "We can't find any place where we can't find anything new".

Read more........

Posted by: Kelly      Permalink         Source