May 21, 2010, 6:48 AM CT

'Scrubbing' chemical-contaminated buildings

Dhiren Barot was an al Qaeda operative involved in plots to blow up the London subway, among other targets. To maximize the damage and the terror, he planned to pack some of his bombs with toxic gas. Fortunately, in August 2004, British authorities nabbed Barot and his accomplices before they could carry out their attacks.

But the threat of a gas attack remains. Where Barot failed, at some point someone might succeed. The right response to such an attack could minimize exposure and save hundreds of thousands of American lives.

With funding and guidance from the Department of Homeland Security's Science and Technology Directorate (S&T), chemists at Idaho National Laboratory (INL) are researching ways to help the nation respond to and clean up after potential chemical attacks. They have been studying decontamination techniques for almost a decade.

Cleaning up chemical-contaminated structures can be difficult, costly, and time-consuming. For one thing, most preferred methods employ other chemicals, like bleach solutions, which can be corrosive and aggressive. A number of building materialslike cement and brickare extremely porous and getting contaminants off such surfaces is difficult, as contaminants will seep into cracks and pores.

As per Donald Bansleben, program manager in S&T's Chemical and Biological Division, lasers could one day play a big role. "Lasers could help to scrub chemical-contaminated buildings clean and become a tool in the toolbox to speed a facility's return to normal operations"......... Posted by: Sarah      Read more         Source

May 4, 2010, 7:12 AM CT

Global warming-free industrial materials

Let a bunch of fluorine atoms get together in the molecules of a chemical compound, and they're like a heavy metal band at a chamber music festival. They tend to dominate the proceedings and not always for the better.

That's especially true where the global warming potential of the chemicals is concerned, says a newly released study by NASA and Purdue University researchers.

The study offers at least a partial recipe that industrial chemists could use in developing alternatives with less global warming potential than materials usually used today. The study was reported in the Proceedings of the National Academy of Sciences.

"What we're hoping is that these additional requirements for minimizing global warming will be used by industry as design constraints for making materials that have, perhaps, the most green chemistry," says Joseph Francisco, a Purdue chemistry and earth and atmospheric sciences professor.

The classes of chemicals examined in the study are widely used in air conditioning and the manufacturing of electronics, appliances and carpets. Other uses range from applications as a blood substitute to tracking leaks in natural gas lines.

The chemicals include fluorine atom-containing compounds such as hydro fluorocarbons, per fluorocarbons, hydrofluoroethers, hydrofluoroolefins, and sulfur and nitrogen fluorides......... Posted by: Tyler      Read more         Source

May 4, 2010, 7:09 AM CT

Aboriginal hunting and burning increase Australia's desert biodiversity

In Australia, Martu hunter-gatherers light fires to expose the hiding places of their prey: monitor lizards called goanna that can grow up to 6 feet long. These generations-old hunting practices, part of the Martu day-to-day routine, have reshaped Australia's Western Desert habitats, as per Stanford University anthropologists Douglas and Rebecca Bird.

"Martu" refers to a group of about 800 indigenous Australians from eight dialect-groups that inhabit the Western Desert. For 10 years, the Birds have been investigating Martu hunting strategies and their lasting environmental impacts. With support from the Woods Institute for the Environment at Stanford, the scientists have begun to explore what makes aboriginal hunting grounds molded by fire more biologically diverse than lands untouched by humans.

"The results of our work will be used to assist conservation efforts and joint indigenous land management policy in the Western Desert," said Douglas Bird, an assistant professor (research) of anthropology and principal investigator on the Woods Institute Environmental Venture Projects grant.

In a number of cases, humans aren't the wrench in nature's gears but an important piece of the clockwork, he added. And because so much of Australia's Western Desert, from lizards to shrubs, revolves around Martu practices, conservation efforts will succeed only if they incorporate traditional goanna-hunting practices, he said......... Posted by: Tyler      Read more         Source

April 29, 2010, 6:40 AM CT

Part of Alaska inundated by ancient megafloods

New research indicates that one of the largest fresh-water floods in Earth's history happened about 17,000 years ago and inundated a large area of Alaska that is now occupied in part by the city of Wasilla, widely known because of the 2008 presidential campaign.

The event was one of at least four "megafloods" as Glacial Lake Atna breached ice dams and discharged water. The lake covered more than 3,500 square miles in the Copper River Basin northeast of Anchorage and Wasilla.

The megaflood that covered the Wasilla region released as much as 1,400 cubic kilometers, or 336 cubic miles, of water, enough to cover an area the size of Washington, D.C., to a depth of nearly 5 miles. That water volume drained from the lake in about a week and, at such great velocity, formed dunes higher than 110 feet, with at least a half-mile between crests. The dunes appear on topographical maps but today are covered by roads, buildings and other development.

"Your mind doesn't get around dunes of that size. Obviously the water had to be very deep to form them," said Michael Wiedmer, an Anchorage native who is pursuing graduate studies in forest resources at the University of Washington.

Wiedmer is the main author of a paper describing the Wasilla-area megaflood, reported in the May edition of the journal Quaternary Research Co-authors are David R. Montgomery and Alan Gillespie, UW professors of Earth and space sciences, and Harvey Greenberg, a computer specialist in that department......... Posted by: Tyler      Read more         Source

April 25, 2010, 12:36 AM CT

Non-organic mechanism for greenhouse gas

In so a number of ways, Don Juan Pond in the Dry Valleys of Antarctica is one of the most unearthly places on the planet. An ankle-deep mirror between mountain peaks and rubbled moraine, the pond is an astonishing 18 times saltier than the Earth's oceans and virtually never freezes, even in temperatures of more than 40 degrees below zero Fahrenheit.

Now, a research team led by biogeochemists from the University of Georgia has discovered at the site a previously unreported chemical mechanism for the production of nitrous oxide, an important greenhouse gas. Possibly even more important, the discovery could help space researchers understand the meaning of similar brine pools in a place whose ecosystem most closely resembles that of Don Juan Pond: Mars.

The research, published April 25 in the journal Nature Geoscience, adds an intriguing new variable to growing evidence that there has beenand may still beliquid water on Mars, a usual prerequisite for the formation of life. In fact, the new findings could help space researchers develop sensors for detecting such brines on Marsthus narrowing the search for places where life may exist.

"The pond's soils and brines and the surrounding rock types are similar to those found on Mars," said Samantha Joye, a faculty member in the department of marine sciences in the Franklin College of Arts and Sciences and main author on the paper. "So it provides an ideal location to assess microbial activity in extreme environments. While we did not detect any 'bio-gases' such as hydrogen sulfide and methane, we did, surprisingly, measure high concentrations of nitrous oxide, which is normally an indicator of microbial activity. We needed to find out whether a non-organic process could account for this nitrous oxide production"......... Posted by: Tyler      Read more         Source

March 31, 2010, 8:00 PM CT

Young Salamanders' Movement Over Land

Amphibians-frogs, toads, salamanders, and newts-are disappearing worldwide, but the stream salamanders of the Appalachian Mountains appear to be stable. This region is home to the largest diversity of salamanders in the world (more than 70 species reside here), and researchers want to understand what contributes to the stability of these salamander populations.

In research reported in the March 29, 2010 issue of the Proceedings of the National Academy of Sciences, Dr. Evan Grant (a research associate in the University of Maryland Department of Biology and wildlife biologist with the US Geological Survey's Amphibian Research and Monitoring Initiative); along with Dr. William Fagan, University of Maryland Department of Biology; and collaborators James Nichols, US Geological Survey (USGS) Patuxent Wildlife Research Center; and Winsor Lowe, University of Montana; describe how two species of stream salamanders find new homes by moving both within streams and over land to adjacent streams during multiple life stages, and how this movement may help to stabilize their populations.

"Researchers tend to be more focused on populations that are declining or threatened," explains Grant, "but it is also important to look at the populations that are doing well, and to understand what makes the population or species more stable. You can apply this to interpret what might be happening with populations that are declining"......... Posted by: Jaison      Read more         Source

March 22, 2010, 8:03 PM CT

New bacteria strain to make super bread

What better venue than San Francisco sourdough capital of the world to unveil a new natural sourdough ingredient that could replace conventional additives in a variety of other breads, while making them tastier and more healthful? And that's what researchers described today at the American Chemical Society's 239th National Meeting, being held here.

In the study, Maija Tenkanen, Ph.D., and his colleagues reported discovery and use of a new strain of bacteria that convert the sugars in bread dough into produce dextrans. Dextrans are sugar molecules associated withgether into long chains that improve the texture and taste of the sourdough and help keep the bread fresh. These bacteria are available commercially, but produce large amounts of lactic acid along with dextrans.

"The advantage of this new strain of bacteria is that while it produces 10 times more dextran than products on the market now, it doesn't produce large amounts of acid," Tenkanen said. "Because of this feature, and because the added amount of natural dextran could actually improve the flavor, this could be used in place of additives for a broad variety of breads".

She also said the new dextrans may act as so-called "prebiotics," non-digestible food ingredients that stimulate the growth or activity of bacteria in the digestive system which are beneficial to health......... Posted by: Sarah      Read more         Source

March 22, 2010, 7:41 PM CT

Learning about riparian areas from photographs

Riparian areas, ecosystems caught between the land and the stream, are subject to spatial and temporal variability. Effectively managing and protecting riparian areas as well as other ecosystems require understanding these concepts. Fortunately, researchers are investigating new approaches in experiential learning, or learning from direct experiences.

One of those approaches is photography. By taking photographs of a specific site for a period of years (repeat photography), you can see if changes have occurred. From the personal experiences of two researchers from the University of Arizona, Dr. George Zaimes and Dr. Michael Crimmins, illustrations can be effective educational tools for explaining difficult concepts; this is especially true in using before and after pictures of riparian sites or other natural ecosystems.

Zaimes and Crimmins developed two experiential learning exercises using existing repeat photographs of riparian areas in the state of Arizona that were presented in two different workshops. The results are reported in the 2010 Journal of Natural Resources and Life Sciences Education, published by the American Society of Agronomy, the Crop Science Society of America, and the Soil Science Society of America. Funding for this project was provided by University of Arizona Cooperative Extension......... Posted by: Tyler      Read more         Source

March 19, 2010, 10:54 AM CT

Revisiting Chicxulub

For decades, researchers have accumulated ever-larger datasets that suggest an enormous space rock crashed into the ocean off the Yucatan Peninsula more than 65 million years ago, resulting in the Cretaceous-Paleogene (K-Pg) extinction.

Recent research, supported in part by the National Science Foundation (NSF), suggested that the impact could have occurred 300,000 years previous to the K-Pg extinction, and that another cause--perhaps a second impact, or the long-lasting volcanic activity at the Deccan Traps in what is now India--drove numerous plant and animal species to their end.

Now, an interdisciplinary team of 41 researchers from 12 nations, also supported in part by NSF, has prepared a paper to specifically counter the volcanic and dual-impact alternatives, a comprehensive review of the multiple, global lines of evidence linking a single impact near what is now Chicxulub, Mexico, to the timing and breadth of the K-Pg extinction.

The researchers, led by Peter Schulte of the University of Erlangen-Nuremburg, present their findings in the March 5, 2010, issue of Science.

"We felt it important to present the wealth of data now available about the remarkable and exact connection between the impact in the Yucatan and the extinction event at the K-Pg boundary," said University of Texas geophysicist Sean Gulick, one of the authors on the paper......... Posted by: William      Read more         Source

March 19, 2010, 10:45 AM CT

Rapid Response Oceanographic Expedition to Chile

Researchers funded by the National Science Foundation (NSF) and affiliated with the Scripps Institution of Oceanography (SIO) at the University of California at San Diego are undertaking an expedition to explore the rupture site of the 8.8-magnitude Chilean earthquake.

The quake is one of the largest in recorded history.

The researchers hope to capitalize on a unique scientific opportunity to capture fresh data from the event. They will study changes in the seafloor that resulted from movements along faults and submarine landslides.

The "rapid response" expedition, called the Survey of Earthquake And Rupture Offshore Chile, will take place aboard the research vessel Melville.

The Melville was conducting research off Chile when the earthquake struck.

"This rapid response cruise is a rare opportunity to better understand the processes that affect the generation and size of tsunamis," said Julie Morris, NSF division director for Ocean Sciences. "Seafloor evidence of the quake will contribute to understanding similar earthquake regions worldwide".

An important aspect of the rapid response mission involves swath multibeam sonar mapping of the seafloor to produce detailed topographic maps. Data from mapping the earthquake rupture zone will be made public soon after the research cruise ends, Morris said......... Posted by: Tyler      Read more         Source