December 11, 2007, 8:28 PM CT

Himalayan Ice Fields Haven't Grown In Last 50 Years

Ice cores drilled last year from the summit of a Himalayan ice field lack the distinctive radioactive signals that mark virtually every other ice core retrieved worldwide.

That missing radioactivity, originating as fallout from atmospheric nuclear tests during the 1950s and 1960s, routinely provides scientists with a benchmark against which they can gauge how much new ice has accumulated on a glacier or ice field.

In 2006, a joint U.S.-Chinese team drilled four cores from the summit of Naimona'nyi, a large glacier 6,050 meters (19,849 feet) high on the Tibetan Plateau.

The scientists routinely analyze ice cores for a host of indicators - particulates, dust, oxygen isotopes, etc. -- that can paint a picture of past climate in that region.

Researchers think that the missing signal means that this Tibetan ice field has been shrinking at least since the A-bomb test half a century ago. If true, this could foreshadow a future when the stockpiles of freshwater will dwindle and vanish, seriously affecting the lives of more than 500 million people on the Indian subcontinent.

"There's about 12,000 cubic kilometers (2,879 cubic miles) of fresh water stored in the glaciers throughout the Himalayas - more freshwater than in Lake Superior," explained Lonnie Thompson, distinguished university professor of earth sciences at Ohio State University and a researcher with the Byrd Polar Research Center on campus......... Posted by: Tyler      Read more         Source

December 10, 2007, 10:56 PM CT

Food source threatened by carbon dioxide

Carbon dioxide increasing in the atmosphere may affect the microbial life in the sea, which could have an impact on a major food source, warned Dr Ian Joint at a Science Media Centre press briefing today.

Dr Joint is sequencing the DNA of different ocean bacteria to find out how they will respond to an increase in carbon dioxide. So far from one experiment we have sequenced 300 million bases of DNA, about one tenth the size of the human genome. We are analyzing this ocean genome to see if changes might affect the productivity of the sea.

Worldwide, fish from the sea provide nearly a fifth of the animal protein eaten by man. If microscopic plants that fish eat are affected by carbon dioxide, this may deplete a major food source.

Bacteria still control the world said Dr Joint from Plymouth Marine Laboratory. They ensure that the planet is fertile and that toxic materials do not accumulate. The carbon dioxide produced by humans is turning the oceans into weak acids. This century, the seas will be more acidic than they have been for 20 million years.

There are a number of millions of different bacteria in the ocean. They control the cycling of oxygen, carbon, nitrogen and sulphur; microbes in the sea generate half of the oxygen produced globally every year. So the atmosphere could also be affected by ocean acidification. Bacteria made the earth suitable for animals by producing oxygen nearly 2 billion years ago. We want to find out if human activities will have a major impact on microbial life in the seas and if this is likely to be a problem for mankind in the future......... Posted by: Sarah      Read more         Source

December 10, 2007, 10:21 PM CT

Sculpted 3-D particles could aid diagnostics

MIT engineers have used ultraviolet light to sculpt three-dimensional microparticles that could have a number of applications in medical diagnostics and tissue engineering. For example, the particles could be designed to act as probes to detect certain molecules, such as DNA, or to release drugs or nutrients.

The new technique offers unprecedented control over the size, shape and texture of the particles. It also allows scientists to design particles with specific chemical properties, such as porosity (a measure of the void space in a material that can affect how fast different molecules can diffuse through the particles).

"With this method, you can rationally design particles, and precisely place chemical properties," said Patrick Doyle, associate professor of chemical engineering. Doyle is one of the authors of a paper on the work appeared in the Dec. 3 issue of the journal Angewandte Chemie, published by the German Chemical Society.

The research team started with a method that Doyle and his students reported in a 2006 issue of Nature Materials to create two-dimensional particles. Called continuous flow lithography, this approach allows shapes to be imprinted onto flowing streams of liquid polymers. Wherever pulses of ultraviolet light strike the flowing stream of small monomeric building blocks, a reaction is set off that forms a solid polymeric particle. They have now modified that method to add three-dimensionality......... Posted by: Kevin      Read more         Source

December 10, 2007, 9:17 PM CT

Massive dinosaur discovered in Antarctica

A new genus and species of dinosaur from the Early Jurassic has been discovered in Antarctica. The massive plant-eating primitive sauropodomorph is called Glacialisaurus hammeri and lived about 190 million years ago.

The recently published description of the new dinosaur is based on partial foot, leg and ankle bones found on Mt. Kirkpatrick near the Beardmore Glacier in Antarctica at an elevation of more than 13,000 feet.

The fossils were painstakingly removed from the ice and rock using jackhammers, rock saws and chisels under extremely difficult conditions over the course of two field seasons, said Nathan Smith, a graduate student at The Field Museum. They are important because they help to establish that primitive sauropodomorph dinosaurs were more broadly distributed than previously thought, and that they coexisted with their cousins, the true sauropods.

The findings were published online Dec. 5 in the Acta Palaeontologica Poloncica (see http://www.app.pan.pl/). Diego Pol, a paleontologist at the Museo Paleontolgico Egidio Feruglio in Chubut, Argentina, is the other co-author of the research.

Sauropodomorph dinosaurs were the largest animals to ever walk the earth. They were long-necked herbivores and include Diplodocus and Apatosaurus. Their sister group is the theropods, which include Tyrannosaurus, Velociraptor, and modern birds......... Posted by: William      Read more         Source

December 7, 2007, 9:14 PM CT

New research may lead to better climate models

One hundred fifty researchers from more than 40 universities in nine countries are starting a coordinated program aimed at gaining new insights about the Earth's climate and the complex, interconnected system involving the oceans, the atmosphere and the land.

The program will study the southeastern Pacific Ocean, the marine area off South America's west coast a region where the interplay among low clouds, strong low-level winds, coastal ocean currents, surfacing of deep water, the Andes Mountains, aerosols and other factors shape the regional climate and affect global weather in ways that are poorly understood.

"Our research should produce a better understanding of the southeast Pacific Ocean system and improve our global computer climate models, which would lead to more confidence in climate forecasts, including predictions about global warming," said UCLA professor of atmospheric and oceanic sciences C. Roberto Mechoso, who chairs the program, known as VOCALS (VAMOS Ocean-Cloud-Atmosphere-Land Study). "Models currently used for climate change studies have systematic errors concerning the southeastern Pacific Ocean, and because the models are not accurate for such an extensive area, the El Nios they produce in the Pacific are questionable as well. We hope our research will get rid of, or at least greatly decrease, these uncertainties." ......... Posted by: Tyler      Read more         Source

December 6, 2007, 8:09 PM CT

Scientists issue Bali climate change warning

More than 200 leading climate researchers have today warned the United Nations Climate Conference of the need to act immediately to cut greenhouse gas emissions, with a window of only 10-15 years for global emissions to peak and decline, and a goal of at least a 50 per cent reduction by 2050.

The roll-call of top climate scientists includes five University of East Anglia scientists: Prof Corinne Le Qur (also of the British Antarctic Survey), Prof Andrew Watson, Dr Dorothee Bakker, Dr Erik Buitenhuis and Dr Nathan Gillett.

The signatories warn that if immediate action is not taken, a number of millions of people will be at risk from extreme events such as heat waves, drought, floods and storms, with coasts and cities threatened by rising sea levels, and a number of ecosystems, plants and animal species in serious danger of extinction.

The researchers, who include a number of of the worlds most acclaimed climate scientists, have issued the Bali Climate Declaration by Researchers in which they call on government negotiators from the 180 nations represented at the meeting to recognize the urgency of taking action now. They say the world may have as little as 10 years to start reversing the global rise in emissions.

Prof Le Qur said: Climate change is unfolding very fast. There is only one option to limit the damages: stabilise the concentration of CO2 and other greenhouse gases in the atmosphere......... Posted by: Tyler      Read more         Source

December 6, 2007, 7:48 PM CT

Hells Gate yields greenhouse gas-eating bug

A new species of bacteria discovered living in one of the most extreme environments on Earth could yield a tool in the fight against global warming.

In a paper published recently in the prestigious science journal Nature, U of C biology professor Peter Dunfield and his colleagues describe the methane-eating microorganism they found in the geothermal field known as Hells Gate, near the city of Rotorua in New Zealand. It is the hardiest methanotrophic bacterium yet discovered, which makes it a likely candidate for use in reducing methane gas emissions from landfills, mines, industrial wastes, geothermal power plants and other sources.

This is a really tough methane-consuming organism that lives in a much more acidic environment than any weve seen before, said Dunfield, who is the lead author of the paper. It belongs to a rather mysterious family of bacteria (called Verrucomicrobia) that are found everywhere but are very difficult to grow in the laboratory.

Methanotrophic bacteria consume methane as their only source of energy and convert it to carbon dioxide during their digestive process. Methane (usually known as natural gas) is 20 times more potent a greenhouse gas than carbon dioxide and is largely produced by decaying organic matter. Researchers have long known that vast amounts of methane are produced in acidic environments, not only geothermal sites but also marshes and peat bogs. Much of it is consumed by methanotrophic bacteria, which serve an important role in regulating the methane content of the worlds atmosphere......... Posted by: Tyler      Read more         Source

December 6, 2007, 7:21 PM CT

Chemical triggers for aggression in mice

The work, reported in an advance, online issue of the journal Nature on December 6, 2007, furthers the broad and important goal of elucidating how the neurological system can detect and respond to specific cues in of a sea of potential triggers.

These results are a really exciting starting place for us to understand how pheromones and the brain can shape behavior, says team leader Lisa Stowers of the Scripps Research Department of Cell Biology.

Pheromones are chemical cues that are released into the air, secreted from glands, or excreted in urine and picked up by animals of the same species, initiating various social and reproductive behaviors.

Eventhough the pheromones identified in this research are not produced by humans, the regions of the brain that are tied to behavior are the same for mice and people, says James F. Battey, Jr., director of the National Institute on Deafness and Other Communication Disorders (NIDCD) of the National Institutes of Health, which provided funding for the study. Consequently, this research may one day contribute to our understanding of the neural pathways that play a role in human behavior. Much is known about how pheromones work in the insect world, but we know very little about how these chemicals can influence behavior in mammals and other vertebrates......... Posted by: Ashley      Read more         Source

December 5, 2007, 8:34 PM CT

'Flying Fish' unmanned aircraft takes off

Flying fish were the inspiration for an unmanned seaplane with a 7-foot wingspan developed at the University of Michigan. The autonomous craft is thought to bethe first seaplane that can initiate and perform its own takeoffs and landings on water.

Funded by the Department of Defense's Defense Advanced Research Projects Agency (DARPA), it is designed to advance the agency's "persistent ocean surveillance" program.

Engineering scientists from U-M recently returned from sea trials off the coast of Monterey, Calif., where they demonstrated the craft's capability to DARPA officials.

"The vehicle did very well," said Hans Van Sumeren, associate director of the U-M Marine Hydrodynamics Laboratories. "To take off and land in the water was a big effort. We did it 22 times."

The scientists named the robotic plane Flying Fish after its inspiration. Guy Meadows, director of the U-M Marine Hydrodynamics Laboratories, conceived of the design while out on the water. "I saw these fish pop up and soar over the waves," Meadows said.

That got Meadows and colleagues looking at sea birds for a design for their craft.

"We studied sea birds seriously," Meadows said. "They're all about the same size---about 20 pounds with a 2-meter wingspan. It turns out that, aerodynamically speaking, that's a sweet spot to be flying close to the water. Our plane is about the size of a large pelican."........ Posted by: Kevin      Read more         Source

December 4, 2007, 10:28 PM CT

Rapid Maturation In A Neanderthal Child

An international European research collaboration led by researchers at the Max Planck Institute for Evolutionary Anthropology reports evidence for a rapid developmental pattern in a 100,000 year old Belgian Neanderthal (Homo neanderthalensis). The report, published in Proceedings of the National Academy of Sciences USA (online edition early December), details how the team used growth lines both inside and on the surfaces of the child's teeth to reconstruct tooth formation time and its' age at death. Researchers found differences in the duration of tooth growth in the Neanderthal when in comparison to modern humans, with the former showing shorter times in most cases. This faster growth resulted in a more advanced pattern of dental development than in fossil and living members of our own species (Homo sapiens). The Scladina juvenile, which appears to be developmentally similar to a 10-12 year old human, was estimated to be in fact about 8 years old at death. This pattern of development appears to be intermediate between early members of our genus (e.g., Homo erectus) and living people, suggesting that the characteristically slow development and long childhood is a recent condition unique to our own species.

Neanderthal life history, or the timing of developmental and reproductive events, has been under great debate during the past few decades. Across primates, tooth development, specifically the age of molar eruption, is correlation to other developmental landmarks such as weaning and first reproduction. Researchers have previously found evidence to both support and refute the idea that Neanderthals grew up differently than our own species. In this new study, scientists used information from the inside of a molar tooth, coupled with data from micro-computed tomography (micro-CT), as well as evidence of developmental stress on the outsides of tooth crowns and roots. This yields the first chronology, or time sequence, for Neanderthal tooth growth, which differs from living humans. The Scladina Neanderthal grew teeth over a shorter period of time, and has more teeth erupted (present in the mouth), than similarly-aged fossil or living humans (Homo sapiens). This suggests that other aspects of physical development were likely more rapidly achieved as well, implying significant differences in the behaviour or social organization of these ancient humans......... Posted by: William      Read more         Source