January 28, 2008, 10:35 PM CT

Lusty voles, mindless of danger, mate like rabbits

Forgetful Casanovas are lucky in love.

At least thats how University of Florida scientists interpret the results of new research on the mating habits and nervous systems of prairie voles. An article about the research, which examined both the voles behavior and their brains, appears in this weeks edition of the Proceedings of the National Academy of Sciences.

Prairie voles, aka Microtus ochrogaster, are common native rodents in the central U.S. and southern Canada. Because they mate for life and are relatively easy to study, the mouse-like creatures have been the subject of much research by researchers probing questions of monogamy and sexual faithfulness among mammals.

Steve Phelps, an assistant professor of zoology and one of the papers three authors, said a number of male voles pick a female partner and settle in a territory often for life. A minority, however, shirks steady partners and home bases, instead ranging across other males turf and mating with other males females.

Alexander Ophir, a postdoctoral associate in zoology at UF, is the papers lead author and conducted the research, which is funded by the National Science Foundation. Ophir, Phelps and Jerry Wolff, a biologist at St. Cloud State University in Minnesota, set out to find out what makes the male wanderers wander behavior all the more puzzling because faithful males enthusiastically defend their partners, lunging at and biting the interlopers......... Posted by: Kelly      Read more         Source

January 28, 2008, 10:32 PM CT

Elephant engineers

It is like the premise of a popular home improvement show: in the before photos, the surroundings are undesirable and in the after shot theres lots of attractive spaces to grab a meal, start a family and relax in seclusion from lifes stresses. The difference here is that the potential new homeowner is a lizard and the renovations come -- not from a sophisticated Manhattan designer -- but instead from a herd of elephants. An examination of the connections between elephants and lizards appears this month in the journal Ecology, where a researcher reports that the elephants eating habits have a strong influence on the lizards habitat choices. The results demonstrate an important and little understood aspect of ecosystem engineering, and may help land managers working on wildlife refuges in Africa.

Working at the Mpala Research Center in Kenya between 2004 and 2007, the author of the report, Robert M. Pringle of Stanford University, observed that Kenya dwarf geckos (Lygodactylus keniensis) showed a strong preference for trees which had been damaged by browsing elephants (Loxodontia africana). In fact, the local lizard population increased proportionally with the number of damaged trees. By contrast, lizards were virtually absent from undamaged trees in the same study area......... Posted by: Kelly      Read more         Source

January 28, 2008, 10:15 PM CT

Race against time to save Tasmanian devils

A delegation of Tasmanian government officials traveled halfway around the world to visit Cold Spring Harbor Laboratory (CSHL), to lend their support and extend their gratitude for research aimed at understanding a unique transmissible and rapidly spreading cancer that threatens the very existence of Tasmanian devils. To combat this especially aggressive disease, a CSHL research team in collaboration with 454 Lifesciences is committing resources to sequence parts of the devils genome in an effort to increase the odds of saving them from extinction.

In 1996 researchers first discovered the facial tumors on Tasmanian devils. Subsequent research revealed that the cancer is transmitted from one devil to another when tumor cells are transplanted through fighting, biting, and other physical contact. Once afflicted with the cancer, aggressive tumors begin to appear on the face and neck of the devils, restricting their ability to eat. Within approximately three months, the devils succumb to the disease and often die of starvation. The disease has decimated the devil population by nearly 90 percent in certain geographical areas of Tasmania, and officials project that within twenty years the entire species could become extinct.

The process by which the disease spreads among the devils has only been seen once before and represents a new field in cancer biology. Inbreeding in wild populations may prevent the devils immune system from recognizing the cancer as foreign, allowing the cancer to be transmitted. To provide an alternate fate for the devils, the Tasmanian government will have an insurance population of more than two hundred devils in quarantined facilities before the end of 2008......... Posted by: Kelly      Read more         Source

January 28, 2008, 5:20 AM CT

Plant Gene that Affects Stress Resistance

A University of Saskatchewan team of researchers has isolated a gene that has never before been identified in helping plants to resist stress.

The study-published this month in the top-ranked plant journal The Plant Cell-could pave the way for development of agricultural and forestry crops that are more tolerant to environmental stresses such as ultra-violet light and other types of radiation.

"Our next step is to see if plant genes we've isolated also play a similar role in fighting infections," said U of S microbiologist Wei Xiao. "In prior research, our team and others have shown that similar genes in human and animal cells play an important role in protection against both viral and bacterial infections".

In an unusual collaboration, Xiao teamed up with U of S biochemist Hong Wang, two post-doctoral fellows and three graduate students on the study. Doctoral student Rui Wen is the lead author on the paper.

Using Arabidopsis, a widely accepted research model plant closely correlation to canola, the team cloned and characterized four genes suspected of playing a role in the plant's stress responses. The team observed that when plants were subjected to a DNA-damaging stressor, the plants in which one of the four genes had been turned off produced seedlings that grew slower and often died, compared with a control group......... Posted by: Erica      Read more         Source

January 24, 2008, 10:58 PM CT

When accounting for the global nitrogen budget, don't forget fish

Like bank accounts, the nutrient cycles that influence the natural world are regulated by inputs and outputs. If a routine withdrawal is overlooked, balance sheets become inaccurate. Over time, overlooked deductions can undermine our ability to understand and manage ecological systems.

Recent research by the Universite de Montreal (Canada) and the Cary Institute of Ecosystem Studies (Millbrook, New York) has revealed an important, but seldom accounted for, withdrawal in the global nitrogen cycle: commercial fisheries. Results, published as the cover story in the recent issue of Nature Geoscience, highlight the role that fisheries play in removing nitrogen from coastal oceans.

Nitrogen is essential to plant and animal life; however, it is possible to have too much of a good thing. During the past century, a range of human activities have increased nitrogen inputs to coastal waters. Fertilizer run-off is the best documented and most significant source of terrestrial nitrogen pollution. Nitrogen-rich fertilizer applied to farmland eventually makes its way into coastal waters via a network of streams and rivers.

Research spearheaded by Roxane Maranger (Universite de Montreal) and Nina Caraco (Cary Institute) demonstrates that commercial fisheries play an important but declining role in removing terrestrial nitrogen from coastal waters. Accounting for this withdrawal is crucial; terrestrial-derived nitrogen can stimulate coastal phytoplankton growth, leading to eutrophication. Typically eutrophic waters are characterized by reduced dissolved oxygen, decreased biodiversity, and species composition shifts......... Posted by: Kelly      Read more         Source

January 22, 2008, 11:04 PM CT

Storing on Svalbard Global Seed Vault

At the end of January, more than 200,000 crop varieties from Asia, Africa, Latin America and the Middle East-drawn from vast seed collections maintained by the Consultative Group on International Agricultural Research (CGIAR)-will be shipped to a remote island near the Arctic Circle, where they will be stored in the Svalbard Global Seed Vault (SGSV), a facility capable of preserving their vitality for thousands of years.

The cornucopia of rice, wheat, beans, sorghum, sweet potatoes, lentils, chick peas and a host of other food, forage and agroforestry plants is to be safeguarded in the facility, which was created as a repository of last resort for humanity's agricultural heritage. The seeds will be shipped to the village of Longyearbyen on Norway's Svalbard archipelago, where the vault has been constructed on a mountain deep inside the Arctic permafrost.

The vault was built by the Norwegian government as a service to the global community, and a Rome-based international NGO, the Global Crop Diversity Trust, will fund its operation. The vault will open on February 26, 2008.

This first installment from the CGIAR collections will contain duplicates from international agricultural research centers based in Benin, Colombia, Ethiopia, India, Kenya, Mexico, Nigeria, Peru, the Philippines and Syria. Collectively, the CGIAR centers maintain 600,000 plant varieties in crop genebanks, which are widely viewed as the foundation of global efforts to conserve agricultural biodiversity......... Posted by: Erica      Read more         Source

January 21, 2008, 9:11 PM CT

Captive carnivores not up to wild living

A study by the University of Exeter has highlighted the problems of reintroducing animals to the wild for conservation projects. Published online in the journal Biological Conservation, the research highlights the low survival rates of captive carnivores that are released into their natural habitats. On average only one in three captive-born carnivores survives in the wild, with most deaths correlation to human activities.

Recent high-profile conservation projects have involved reintroducing wolves into the Scottish Highlands, bringing red kites back to England and reintroducing golden lion tamarins to Brazil. Most of these animals were born in captivity, with zoos playing a major role in such projects, while other schemes involve moving wild animals to new areas.

This study evaluated 45 case studies, involving 17 carnivore species, and observed that only 30% of captive animals released survived. Over half the deaths were caused by humans in incidents such as shootings and car accidents. The animals were also more susceptible to starvation and disease than their wild counterparts and less able to form successful social groups.

Kristen Jule, lead author on the paper and University of Exeter PhD student, says: Animals in captivity do not commonly have the natural behaviours needed for success in the wild. Their lack of hunting skills and their lack of fear towards humans, for example, are major disadvantages. We have suspected for some time that captive born animals fared less well than wild animals, but here it is finally quantified, and the extent of the problem is critical......... Posted by: Kelly      Read more         Source

January 17, 2008, 9:19 PM CT

Predators do more than kill prey

The direct effect predators have on their prey is to kill them. The evolutionary changes that can result from this direct effect include prey that are younger at maturity and that produce more offspring.

But killing prey also has indirect effects rarely characterized or measured such as a decline in the number of surviving prey, resulting, in turn, in more food available to survivors.

In a new study characterizing the complex ecological interactions that shape how organisms evolve, UC Riverside biologists Matthew Walsh and David Reznick present a novel way of quantifying these indirect effects by showing that prey adapt to food availability as well as the presence of predators.

Our study can serve as a model for how humans alter ecosystems when they remove key predators like wolves and bears from land or tuna and billfish from seas, said Reznick, a professor of biology.

He and Walsh compared life history traits between Trinidadian fish communities impacted by the presence of predators. They settled on Trinidadian waterfalls as study sites because the waterfalls serve as barriers to the upstream distribution of predator and prey fish, thereby creating distinct ecological communities in similar habitats only a few hundred meters from each other like test-tubes in nature......... Posted by: Kelly      Read more         Source

January 17, 2008, 9:04 PM CT

Clams Convert Air Into Food

Only plants can take nitrogen gas from the air and use it to make the protein they need to grow. Or so biologists thought.

Now researchers at Ocean Genome Legacy in Ipswich, Mass., and their colleagues at Harvard Medical School have shown that animals, too, can convert air into food. The National Science Foundation (NSF) funded their research.

The animals are marine clams called shipworms. They burrow into and eat wood, causing more than a billion dollars in damage to ships and piers each year.

"Wood has very little nutritional value," said biologist Dan Distel, executive director of Ocean Genome Legacy. "It contains almost no protein. But these clams use bacterial symbionts living inside a special organ in their gills to convert dissolved air [which is about 80 percent nitrogen] into the protein they need".

The discovery reveals a new way for animals to feed and suggests that other animals in the sea and elsewhere may be able to survive with only air as a source of protein.

Understanding how these clams make use of this process is also helping scientists gain insights into how plants fix nitrogen, responsible for a large percentage of the protein made by plants and ultimately eaten by livestock and humans, said Distel and his colleagues Claude Lechene and Gregory McMahon of Harvard Medical School and Yvette Luyten of Ocean Genome Legacy......... Posted by: Kelly      Read more         Source

January 17, 2008, 8:45 PM CT

High-Vitamin Corn Could Improve Nutrition

Researchers have developed a potentially powerful new tool in the fight against deficiencies in dietary vitamin A, which cause eye diseases, including blindness, in 40 million children annually, and increased health risks for about 250 million people, mostly in developing countries.

This tool consists of "a new method of analyzing the genetic makeup of corn that will enable developing countries to identify and increase cultivation of corn that has naturally high levels of vitamin A precursors," says Ed Buckler, a co-leader of the research team from the U.S. Department of Agriculture, Agricultural Research Service and Cornell University.

Corn is an essential part of the diets of hundreds of millions of people around the world, a number of of whom live in developing countries. Regular consumption by adults and children of adequate quantities of corn high in vitamin A precursors, which are converted in the human body into vitamin A, would reduce their chances of developing vitamin A deficiencies and associated health problems.

This new method of increasing cultivation of high-vitamin corn is designed to tap the natural genetic diversity of corn. It was developed by a team led by Buckler and Torbert Rocheford of the University of Illinois, and was partially funded by The National Science Foundation (NSF). It will be described in the January 18, 2007 edition of Science......... Posted by: Erica      Read more         Source