March 22, 2007, 10:22 PM CT

Biologists Solve Vitamin Puzzle

Solving a mystery that has puzzled researchers for decades, MIT and Harvard scientists have discovered the final piece of the synthesis pathway of vitamin B12--the only vitamin synthesized exclusively by microorganisms.

B12, the most chemically complex of all vitamins, is essential for human health. Four Nobel Prizes have been awarded for research correlation to B12, but one fragment of the molecule remained an enigma--until now.

The scientists report that a single enzyme synthesizes the fragment, and they outline a novel reaction mechanism that requires cannibalization of another vitamin.

The work, which has roots in an MIT undergraduate teaching laboratory, "completes a piece of our understanding of a process very fundamental to life," said Graham Walker, MIT professor of biology and senior author of a paper on the work that will appear in the March 22 online edition of Nature.

Vitamin B12 is produced by soil microbes that live in symbiotic relationships with plant roots. During the 1980s, an undergraduate research course taught by Walker resulted in a novel method for identifying mutant strains of a soil microbe that could not form a symbiotic relationship with a plant.

Walker's team has now observed that one such mutant has a defective form of an enzyme known as BluB that leaves it unable to synthesize B12......... Posted by: Janet      Read more         Source

March 21, 2007, 10:09 PM CT

Tracing the Origins of Marine Creatures

Tracing the origins of marine animals can be extremely difficult, particularly in the free-flowing, soup-like conditions of the ocean, but obtaining this information is vital not only for understanding these organisms but for managing and conserving them as well. Researchers at Scripps Institution of Oceanography at UC San Diego have developed a novel approach for tracing the life roots of marine larvae, some of the most difficult organisms to track due to their microscopic sizes.

As per a research findings reported in the Proceedings of the National Academy of Sciences (PNAS), Bonnie Becker, Lisa Levin, Joel Fodrie and Pat McMillan describe a new process for studying mussel larvae through "elemental fingerprinting," a method in which chemical signatures in ocean water are used to construct geographical birthplace maps and baseline profile information about the tiny creatures.

"Elemental fingerprinting is a sort of natural tag," said Levin, a professor in the Integrative Oceanography Division at Scripps. "Basically, the water itself creates a chemical tag and we use that information to figure out where larvae come from".

Developing the new approach involved several labor-intensive steps, including establishing-or "outplanting" as Becker calls it-a series of larval "homes" made of PVC pipe and mesh in 18 locations off San Diego's beaches and bays. Each home contained approximately 100,000 mussel larvae. After a week, the homes and larvae were retrieved along with water samples from each site......... Posted by: Janet      Read more         Source

March 21, 2007, 8:27 PM CT

Ponderosa Pine

The ponderosa pine is the most widely distributed species of its genus in North America. It is generally found in a sub-humid area deficient in summer rainfall. The tree reproduces through seeds produced in cones, which require 2 years to mature.

The Black Hills forest is dominated by the ponderosa pine tree. Where conditions permit, other trees such as the birch, white spruce, quaking aspen, and elm also grow.

Wind Cave National Park can be divided into two major vegetation types: the ponderosa pine forest and the mixed grass prairie. Twenty-five percent of the park is tree covered. The forested area includes ponderosa pine forests and scattered groves of elm, aspen, bur oak, boxelder, and birch. These scattered groves are generally found along drainage areas. The ponderosa pine forest occupies the higher elevations in the park.

The ponderosa is an extravagant user of readily available moisture. It sends down a fast growing taproot which enables it to obtain moisture from a number of levels. As a seedling it also possesses the ability to withstand prolonged drought. The trees are capable of growing exceptionally fast if conditions are good for them. Because of the taproot, the trees can generally withstand high winds. When "wind throw" does occur it is often because the tree has root rot or the root systems are shallow because of the rock on which the tree is growing......... Posted by: Erica      Read more         Source

March 21, 2007, 8:23 PM CT

Coyote - Canis latrans

There are several predators in the Park, including bobcats, eagles, badgers, and cougars, but the coyotes are the most easily seen.

Most research has shown that coyotes commonly feed on small mammals and birds. They do not feed heavily on livestock or larger ungulates, like elk, deer, or bison unless the animal is already dead or dying.

Little is known about the predatory behavior of wild coyotes, but a sudden hop or pounce is most often used for capturing small animals, like shrew or mice, where group effort may be used in the prairie dog towns. Coyotes depend on various senses to locate their prey, with sight, hearing, and smell being most important-commonly in that order.

Coyotes are small mammals, about the size of a medium-sized dog. They vary widely in coloration, ranging from an almost pure gray to a red-brown. The fur is generally much thicker in winter-giving the animal a heavier appearance, with the summer coat being much shorter and lighter.

A wide variety of habitats all across the United States can be called home for the coyote. They are found in both the grasslands and pine forest here in the Park. Each individual coyote or coyote pack has a home territory that is used on a regular basis, but not actively defended except during mating periods and when the coyote pups are in their dens......... Posted by: Kelly      Read more         Source

March 20, 2007, 10:05 PM CT

Global Map of Plant Biodiversity

Biologists at the University of California, San Diego and the University of Bonn in Gera number of have produced a global map of estimated plant species richness. Covering several hundred thousand species, the researchers say their global map is the most extensive map of the distribution of biodiversity on Earth to date.

The map, which accompanies a study published in this week's early online issue of the journal Proceedings of the National Academy of Sciences, highlights areas of particular concern for conservation. It also, the researchers say, provides much needed assistance in gauging the likely impact of climate change on the services plants provide to humans.

Walter Jetz of UCSD and Holger Kreft of the University of Bonn sought in their study to determine how well the diversity, or the "richness," of plant species could be predicted from environmental conditions alone.

"Plants provide important services to humans-such as ornaments, structure, food and bio-molecules that can be used for the development of drugs or alternative fuels-that increase in value with their richness," says Jetz, an assistant professor of biology at UCSD and the senior author of the paper. "Tropical countries such as Ecuador or Colombia harbor by a factor 10 to 100 higher plant species richness than most parts of the United States or Europe. The question is, Why?"......... Posted by: Erica      Read more         Source

March 19, 2007, 10:34 PM CT

Medspiration project For biodiversity

Maps of the sea surface temperature around Galapagos Islands and Cocos Island in the Pacific Ocean are being produced daily and are available online in full resolution in near-real time as part of the Medspiration project, an ESA-funded effort to represent the most reliable temperature of the seas on a global basis.

Galapagos Islands and Cocos Island have been integrated into Medspiration until 31 March in order to support the study of wildlife migration processes from the two islands as part of ESA's new Diversity project, which kicked off in January 2007 to support the initiative of the United Nations Convention on Biological Diversity (UNCBD) to reduce significantly the current rate of biodiversity loss by 2010.

The sea surface temperature (SST) map around Galapagos Islands and Cocos Island is one of the various Earth observation-based Diversity products ESA is developing to aid in the conservation and monitoring activities of the different actors involved in UNCBD in Central America - one of the main biodiversity reserves on our planet. Other services and products will include Mesoamerican biological corridor change detection maps, coral reef maps, ocean water quality monitoring services, mangrove maps as well as a map of dry lands.

Medspiration allows users to open very high-resolution maps, down to two square kilometres, anywhere in the world, as illustrated by the map of Galapagos Island. In addition to aiding conservation studies, Medspiration has been delivering SST data of European seas since 2004 to its partners with overall results from the project feeding into an even more ambitious scheme to combine all available SST data into a worldwide high-resolution product known as the Global Ocean Data Assimilation Experiment (GODAE) High-Resolution Sea Surface Temperature Pilot Project (GHRSST-PP)......... Posted by: Janet      Read more         Source

March 14, 2007, 10:15 PM CT

How Plants Manage Calcium

A new understanding of how plants manage their internal calcium levels could lead to modifying plants to avoid damage from acid rain. The pollutant disrupts calcium balance in plants by leaching significant amounts of the mineral from leaves as well as the agricultural and forest soils the plants live in.

"Our findings should help researchers understand how plant ecosystems respond to soil calcium depletion and to design appropriate strategies to protect the environment," said Zhen-Ming Pei, a Duke University biologist who led the study, which is reported in the March 9, issue of the journal Science".

The research was supported by the National Science Foundation (NSF), the U.S. Department of Agriculture and Xiamen University in China.

To grow, a plant needs a reliable supply of calcium, which enters the plant dissolved in water the roots take in from surrounding soil. As the water circulates through a plant, dissolved calcium gets shuttled where it is needed to give the plant's cells their structural rigidity. But calcium supplies coming into the plant cycle up and down over the course of the day, dropping to a minimum at night.

"Calcium is a key regulator of vital physiological functions in both plants and animals," said Maryanna Henkart, director of NSF's Division of Molecular and Cellular Biosciences. "The discovery of the relationship between calcium in soil, in plant cells, and cellular mechanisms sheds new light on the role of this important mineral in plant growth and development"......... Posted by: Erica      Read more         Source

March 14, 2007, 10:12 PM CT

New Mammal From Mesozoic Era

n international team of American and Chinese paleontologists has discovered a new species of mammal that lived 125 million years ago during the Mesozoic Era, in what is now the Hebei Province in China.

The new mammal, documented in the March 15 issue of the journal Nature, provides first-hand evidence of early evolution of the mammalian middle ear--one of the most important features for all modern mammals. The discovery was funded by the National Science Foundation (NSF).

"This early mammalian ear from China is a rosetta-stone type of discovery which reinforces the idea that development of complex body parts can be explained by evolution, using exquisitely preserved fossils," said H. Richard Lane, program director in NSF's Division of Earth Sciences, which co-funded the discovery with NSF's Division of Environmental Biology and its Assembling the Tree of Life (AToL) program.

Named Yanoconodon allini after the Yan Mountains in Hebei, the fossil was unearthed in the fossil-rich beds of the Yixian Formation and is the first Mesozoic mammal recovered from Hebei. The fossil site is about 300 kilometers outside of Beijing.

The researchers discovered that the skull of Yanoconodon revealed a middle ear structure that is an intermediate step between those of modern mammals and those of near relatives of mammals, also known as mammaliaforms......... Posted by: Kelly      Read more         Source

March 14, 2007, 10:06 PM CT

Explosive Growth Changes Salmon Industry

A new report, the first to take a comprehensive look at market competition between wild and farmed salmon, sheds new light on the contentious and complex issues surrounding farmed and wild salmon.

The Great Salmon Run: Competition Between Wild and Farmed Salmon, released by TRAFFIC, the wildlife trade monitoring network of World Wildlife Fund and IUCN-the World Conservation Union identifies two important trends that have remade the salmon industry in the last 25 years: farmed salmon has grown from just two percent of the world supply in 1980 to 65 percent in 2004. About three-fourths of the fresh and frozen salmon consumed in the United States is now farmed. In response, the value of the North American wild fishery has plummeted, as indicated by the decline in the value of annual Alaska salmon catches from more than $800 million in the late 1980's to less than $300 million. The decline in value of wild salmon catches has had wide-ranging economic and social effects on wild salmon fishermen and fishing communities.

"Wild salmon could never supply the market demand being met by farmed salmon. A fundamental point of the report is that the debate should not be about wild versus farmed, but whether each method of production is being done right," says Dr. Gunnar Knapp, professor of economics at the University of Alaska, Anchorage, and one of the study's authors......... Posted by: Kelly      Read more         Source

March 13, 2007, 10:23 PM CT

New Species of Snapper Discovered in Brazil

A popular game fish mistaken by researchers for a dog snapper is actually a new species discovered among the reefs of the Abrolhos region of the South Atlantic Ocean.

The international science journal Zootaxa recently published the discovery of Lutjanus alexandrei, a new snapper species that belongs to the Lutjanidae family, by scientists Rodrigo Moura of Conservation International (CI) and Kenyon Lindeman of Environmental Defense. The study published in Zootaxa provides a revised key for identifying all Lutjanus species in the western Atlantic, along with evidence that the new species completes its life cycle in different but interdependent marine habitats, such as coral reefs and mangroves.

"This discovery that a large, popular fish is a species new to science shows how little we know about the oceans that surround us," Moura said. "It looks like other snapper species found in the Caribbean and eastern United States, as well as the dog snapper caught by fishermen here in Brazil, but it is a distinct species with different markings and color."

Twelve species of the family Lutjanidae, including the new discovery, are now identified in the western Atlantic Ocean. They include Lutjanus griseus and Lutjanus apodus, two species restricted to the Caribbean and eastern coast of the United States but previously believed to occur in Brazilian waters until the discovery of Lutjanus alexandrei......... Posted by: Kelly      Read more         Source