April 23, 2007, 10:44 PM CT

Prehistoric mystery organism verified as giant fungus

Scientists at the University of Chicago and the National Museum of Natural History in Washington, D.C., have produced new evidence to finally resolve the mysterious identity of what they regard as one of the weirdest organisms that ever lived.

Their chemical analysis indicates that the organism was a fungus, the scientists report in the recent issue of the journal of Geology, published by the Geological Society of America. Called Prototaxites (pronounced pro-toe-tax-eye-tees), the organism went extinct approximately 350 million years ago.

Prototaxites has generated controversy for more than a century. Originally classified as a conifer, scientists later argued that it was instead a lichen, various types of algae or a fungus. Whatever it was, it stood in tree-like trunks more than 20 feet tall, making it the largest-known organism on land in its day.

"No matter what argument you put forth, people say, well, thats crazy. That doesnt make any sense," said C. Kevin Boyce, an Assistant Professor in Geophysical Sciences at Chicago. "A 20-foot-tall fungus doesnt make any sense. Neither does a 20-foot-tall algae make any sense, but heres the fossil".

The Geology paper adds a new line of evidence indicating that the organism is a fungus. The fungus classification first emerged in 1919, with Francis Hueber of the National Museum of Natural History in Washington, D.C., reviving the idea in 2001. His detailed studies of internal structure have provided the strongest anatomical evidence that Prototaxites is not a plant, but a fungus......... Posted by: Erica      Read more         Source

April 23, 2007, 10:27 PM CT

How Individual Molecules Recognise Each Other?

If one thinks that there are thousands of times more molecules forming our body than stars in the universe it is astonishing how all these molecules can work together in such an organised and efficient way. How can our muscles contract to make us walk? How can food be metabolised every day? How can we use specific drugs to relieve pain?.

To work as a perfect machine, our body ultimately relies on the capability of each little part (molecule) to know a specific function and location out of countless possibilities. To do this, molecules carry information in different ways. An international team at the Max Planck Institute for Solid State Research in Stuttgart, in collaboration with researchers from the Fraunhofer Institute in Freiburg and the King's College London are seeking to find out how the information can be passed on at the very first steps: from the single molecule level to structures of increasing complexity and functionality.

The key to understanding all biological processes is recognition. Each molecule has a unique composition and shape that allows it to interact with other molecules. The interactions between molecules let us - as well as bacteria, animals, plants and other living systems - move, sense, reproduce and accomplish the processes that keep all living creatures alive......... Posted by: Janet      Read more         Source

April 23, 2007, 10:17 PM CT

How much nitrogen is too much for corn?

North Carolina State scientists recently discovered a test that quickly predicts nitrogen levels in the humid soil conditions of the southeastern United States. These researchers report that the Illinois Soil Nitrogen Test (ISNT) can assess the nitrogen levels in soil with more accuracy than current soil-based tests. This test will allow growers to cut back on the amount of nitrogen-based fertilizer added to soil, leading to economic and environmental benefits.

The proper management of nitrogen is critical to the success of a number of crop systems. Based on an assessment of the natural amount of nitrogen in soil, growers calculate their optimum nitrogen rates, the concentration of nitrogen that must be present in fertilizer in order to achieve expected crop yields. Under- and over-applying nitrogen fertilizer to corn crops often leads to adverse economic consequences for corn producers. Excess levels of nitrogen in nature also pose serious threats to environment. Agricultural application of nitrogen has been associated with rising nitrate levels and subsequent death of fish in the Gulf of Mexico and North Carolinas Neuse River.

"Eventhough offsite nitrogen contamination of ground and surface waters could be reduced if nitrogen rates were adjusted based on actual field conditions, there is currently no effective soil nitrogen test for the humid southeastern U.S.," said Jared Williams, lead author of the North Carolina State study that was reported in the March-April 2007 issue of the Soil Science Society of America Journal. This research was supported in part by USDA Initiative for Future Agricultural and Food Systems (IFAFS) grant......... Posted by: Erica      Read more         Source

April 23, 2007, 10:02 PM CT

Mosquito genes and climate change

University of Oregon scientists studying mosquitoes have produced the first chromosomal map that shows regions of chromosomes that activate and are apparently evolving in animals in response to climate change.

The map will allow scientists to narrow their focus to identify specific genes that control the seasonal development of animals. Such information will help predict which animals may survive in changing climates and identify which disease-carrying vectors may move northward, allowing for the production of appropriate vaccines, said William E. Bradshaw and Christina M. Holzapfel, scientists in the department of biology and members of the UO Center for Ecology and Evolutionary Biology.

"For the first time, we are moving down the track to identify genes that animals use to control their seasonal development," Bradshaw said. "Response to day length is often the primary cue that organisms use for going dormant, and eventhough human beings are not as strongly seasonal as other animals, there are nonetheless seasonal components to our health and welfare just as there are in plants and animals".

The chromosomal map for the mosquito Wyeomyia smithii, which develop within the carnivorous leaves of pitcher plants, appears online ahead of publication in the recent issue of the journal Genetics. The UO scientists identified regions on three chromosomes that respond to length of day, which researchers call photoperiodism. Two of the chromosomes also have overlapping gene expression that tells the species to go dormant, which they must do to survive......... Posted by: Kelly      Read more         Source

April 23, 2007, 9:59 PM CT

World's most endangered cat: Amur leopard

Following the April 18 announcement that only 25 to 34 of the Amur or Far Eastern leopard (Panthera pardus orientalis) remain in the wild, World Wildlife Fund says the number must now be revised because a female Amur leopard was killed.

Anonymous tips led officers of two leopard anti-poaching squads to the body of the leopardess on April 20 about two miles from Bamburovo village within the watershed of Alimovka River on the territory of Barsovy National Wildlife Refuge.

The next day veterinarians from the Zoological Society of London observed that the 77 pound mature female leopard was shot in the back side. The bullet came through tail bone, crushed the hip bones and lodged in the belly. She was then beaten to death with a heavy object.

The killing of even one female is a huge loss for a cat on the brink of extinction, said Darron Collins, managing director of the Amur-Heilong Program, World Wildlife Fund. This years census showed a desperate situation, with just seven female Amur leopards left in the wild and four rearing cubs. Now weve lost a mature, reproductive leopardess and her potential cubs in a senseless killing. This is the third leopard killed within this area over the last five years and underscores the desperate need for a unified protected area with national park status if the leopard is to survive in the wild......... Posted by: Kelly      Read more         Source

April 23, 2007, 5:32 PM CT

Residual Oil is Still Affecting Wildlife

Nearly four decades after a fuel oil spill polluted the beaches of Cape Cod, scientists have found the first compelling evidence for lingering, chronic biological effects on a marsh that otherwise appears to have recovered.

Through a series of field observations and laboratory experiments with salt marsh fiddler crabs (Uca pugnax), doctoral student Jennifer Culbertson and his colleagues observed that burrowing behavior, escape response, feeding rate, and population abundance are significantly altered when the crabs are exposed to leftover oil compounds from a 1969 spill.

The study builds on prior work by scientists from the Woods Hole Oceanographic Institution (WHOI), which showed that oil compounds from the 1969 wreck of the barge Florida are still lingering in the sediments 8 to 20 centimeters below the surface of Wild Harbor in Falmouth, Mass. Burrowing fiddler crabs in the marsh still won't dig more than a few centimeters into the sediments in the areas most affected by the spill.

Culbertson a graduate student from the Boston University Marine Program (BUMP) and a guest student at WHOI, conducted the research in collaboration with WHOI marine chemist Chris Reddy, ecologist Ivan Valiela of the Marine Biological Laboratory, and several student colleagues from WHOI and BUMP. The findings were reported in the online version of Marine Pollution Bulletin on April 19, 2007 and it will appear later this spring in a printed edition......... Posted by: Kelly      Read more         Source

April 21, 2007, 8:40 AM CT

Monkeys' ability to reflect on their thoughts

New research from Columbia's Primate Cognition Laboratory has demonstrated for the first time that monkeys could acquire meta-cognitive skills: the ability to reflect about their thoughts and to assess their performance.

The study was a collaborative effort between Herbert Terrace, Columbia professor of psychology & psychiatry, and director of its Primate Cognition Laboratory, and two graduate students, Lisa Son now professor of psychology at Barnard College and UCLA postdoctoral researcher Nate Kornell.

The study, which appears in the recent issue of Psychological Science, a journal of the Association for Psychological Science, was designed to show that a monkey could express its confidence in its answers to multiple-choice questions about its memory based on the amount of imaginary currency it was willing to wager. Their experiment was derived from the observation that children often make pretend bets to assert that they know the answer to some question. According to Son, "the ability to reflect on one's knowledge has always been thought of as exclusively human. We designed a task to determine if a non-human primate could similarly learn to express its confidence about its knowledge by making large or small wagers".

In the experiment, two monkeys were trained to play a video game that would test their ability to remember a particular photograph while also allowing them to make a large or a small bet. Ultimately, this wager would reflect the monkey's perception of their memory accuracy......... Posted by: Kelly      Read more         Source

April 21, 2007, 8:25 AM CT

Lemmings And Global Warming

Contrary to popular belief, lemmings do not commit mass suicide by leaping off of cliffs into the sea. In fact, they are quite fond of staying alive. A bigger threat to the rodents is climate change, which could deprive them of the snow they need for homes and lock up their food in ice, as per the Wildlife Conservation Society, which is launching a study to examine how these tiny but important players in the ecological health of the far North will fare in the age of global warming.

"We need to know how climate change will affect a variety of resident and migratory predators that rely in large part on these small arctic rodents," said WCS Canada researcher Dr. Don Reid. "The ability of lemmings to adapt to these changes will have a significant impact on the entire food web, so we need to understand more about lemming ecology within the context of climate change."

Lemmings serve as an important prey species for many predators, including arctic foxes, red foxes, rough-legged hawks, peregrine falcons, snowy and short-eared owls, jaegers, gulls, weasels, wolverines, and grizzly bears. In fact, the population of a number of predators fluctuates in response to dips in lemming numbers. One of the key ingredients for lemming abundance and productivity is likely snow. Sufficient snow depth insulates the rodents from frigid temperatures, allowing them to devote more energy to breeding and less to avoiding predators. Later arrival of autumn snows, and earlier spring melts, could subject lemmings to longer periods of sub-freezing temperatures. Also, the tundra is experiencing unusual warm periods in winter, including freezing rain and episodes of thawing and freezing, which can coat much of the lemmings' foods (sedges and dwarf shrubs) in ice......... Posted by: Kelly      Read more         Source

April 21, 2007, 7:34 AM CT

Not Your Average Easter Bunny

Hippity, hoppity.....click! One of the world's rarest rabbits hopped in front of a camera trap planted by Wildlife Conservation Society (WCS) scientists in an Indonesian rain forest. The photos, taken in Bukit Barisan National Park, are only the third images of the Sumatran striped rabbit ever recorded; the rabbit was last photographed there in 2000.

Before the first photo was taken in 1998, the foot-long Sumatran striped rabbit had not been seen alive since 1972. Only 15 specimens exist in museums, all dating from before 1929. The rabbit is only known to inhabit the forested, mountainous spine of its island namesake. It is listed by the World Conservation Union (IUCN) lists as Critically Endangered.

"This rabbit is so poorly known that any proof of its continued existence at all is great news and confirms the conservation importance of Sumatra's forests," said Colin Poole, director of WCS's Asia Program.

Until recently, the Sumatran striped rabbit was believed to be the sole representative of its genus. In 1999, however, scientists discovered another striped rabbit in the Annamite Mountains, which straddle Lao PDR and Vietnam. Eventhough the two species resemble each other, genetic samples revealed them to be closely related but distinct, having diverged about 8 million years ago......... Posted by: Kelly      Read more         Source

April 21, 2007, 7:13 AM CT

Tracking Six-Week-Old Tiger Cubs

Researchers from the Wildlife Conservation Society (WCS) and their Russian colleagues from the Sikhote-Alin Reserve have fitted three six-week-old Siberian tiger cubs with tiny radio collars (below). They are the youngest wild tigers ever to be tracked by scientists. The collars--made of expandable elastic and designed to fall off the cubs as they grow--weigh just over five ounces and would fit well on a large housecat. Radiotracking has given scientists crucial insights into the lives of tigers in the Russian Far East and has led to methods to improve the survival and reproduction of the largest of the cat species.

"Through radio-telemetry, we've learned a great deal about the needs of Siberian tigers, animals so elusive that few field scientists have seen them in their natural habitat," says WCS biologist John Goodrich (left), who heads the Siberian Tiger Project. "Now we can finally get some idea of what causes the deaths of tiger cubs, which suffer a mortality rate of nearly 50 percent in their first year. If we can somehow improve their chances, we can make a big difference in helping the population grow."

The radio transmitters emit a "mortality" signal if the unit remains stationary for more than one hour. Finding an animal quickly is crucial in determining cause of death......... Posted by: Kelly      Read more         Source