April 24, 2008, 9:34 PM CT

Genetic Sequencing of Protein from T. Rex

Researchers have put more meat on the theory that dinosaurs' closest living relatives are modern-day birds.

Molecular analysis, or genetic sequencing, of a 68-million-year-old Tyrannosaurus rex protein from the dinosaur's femur confirms that T. rex shares a common ancestry with chickens, ostriches, and to a lesser extent, alligators.

The dinosaur protein was wrested from a fossil T. rex femur discovered in 2003 by paleontologist John Horner of the Museum of the Rockies; the bone was found in a fossil-rich stretch of land in Wyoming and Montana.

The new research results, published this week in the journal Science, represent the first use of molecular data to place a non-avian dinosaur in a phylogenetic tree, a "tree of life," that traces the evolution of species.

"These results match predictions made from skeletal anatomy, providing the first molecular evidence for the evolutionary relationships of a non-avian dinosaur," says Science paper co-author Chris Organ, a researcher at Harvard University. "Even though we only had six peptides--just 89 amino acids--from T. rex, we were able to establish these relationships".

"Tests of the peptide sequences in T. rex bone fossils have confirmed that newer methods of molecular systematics agree with more traditional methods of taxonomic classification based on morphology, or shapes," says Paul Filmer, program director in the National Science Foundation (NSF)'s Division of Earth Sciences, which funded the research......... Posted by: William      Read more         Source

April 24, 2008, 8:58 PM CT

Injecting Sulfate Particles into Stratosphere

A much-discussed idea to offset global warming by injecting sulfate particles into the stratosphere would have a drastic impact on Earth's protective ozone layer, new research concludes.

The study, led by Simone Tilmes of the National Center for Atmospheric Research (NCAR) in Boulder, Colo., warns that such an approach would delay the recovery of the Antarctic ozone hole by decades and cause significant ozone loss over the Arctic.

The study results are published recently in the journal Science Express. The research was funded by the National Science Foundation (NSF), NCAR's principal sponsor, as well as by NASA and other agencies.

"Our research indicates that trying to artificially cool off the planet may be a perilous endeavor," Tilmes says. "While climate change is a major threat, this solution could create severe problems for society".

"The challenges of global warming mitigation are extremely complex," said Cliff Jacobs, program director in NSF's Division of Atmospheric Sciences. "Continued investment in basic research will allow the most cost-effective solutions--and those of the most benefit to society--to be found".

Climate scientists, concerned that society is not taking sufficient action to prevent significant changes in climate, have studied various "geoengineering" proposals to cool the planet and mitigate the most severe impacts of global warming......... Posted by: Tyler      Read more         Source

April 24, 2008, 8:55 PM CT

Earthquake in Illinois

To the surprise of a number of, the earthquake on April 18, 2008, about 120 miles east of St. Louis, originated in the Wabash Valley Fault and not the better-known and more-dreaded New Madrid Fault in Missouri's bootheel.

The concern of Douglas Wiens, Ph.D., and Michael Wysession, Ph.D., seismologists at Washington University in St. Louis, is that the New Madrid Fault may have seen its day and the Wabash Fault is the new kid on the block.

The earthquake registered 5.2 on the Richter scale and hit at 4:40 a.m. with a strong aftershock occurring at approximately 10:15 a.m. that morning, followed by lesser ones in subsequent days. The initial earthquake was felt in parts of 16 states.

"I think everyone's interested in the Wabash Valley Fault because a lot of the attention has been on the New Madrid Fault, but the Wabash Valley Fault could be the more dangerous one, at least for St. Louis and Illinois," said Wiens, professor of earth and planetary sciences in Arts & Sciences. "The strongest earthquakes in the last few years have come from the Wabash Valley Fault, which needs more investigation."

Wiens said that seismologist Robert Hermann of Saint Louis University, Gary Pavils of Indiana University, and several geologists including Steven Obermeir of the U.S. Geological Survey (USGS), have made studies of the Wabash Valley Fault. Pavils also has run a dense local array of stations and recorded a number of very small earthquakes at the Wabash Valley Fault. Hermann has studied the 1968 magnitude 5.5 earthquake, the largest ever recorded there. Obermeir and others have found disturbed sediments from prior earthquakes along the fault with estimated magnitudes of about 7 on the Richter scale over the past several thousand years......... Posted by: Tyler      Read more         Source

April 22, 2008, 9:25 PM CT

Making New Optical Materials

Chemical engineers have developed a "self-assembling" method that could lead to an inexpensive way of making diamondlike crystals to improve optical communications and other technologies.

The method, developed at Purdue University, works by positioning tiny particles onto a silicon template containing precisely spaced holes that are about one-hundredth the width of a human hair. The template is immersed in water on top of which particles are floating, and the particles automatically fill in the holes as the template is lifted.

The scientists have used the technique to create a "nearly perfect two-dimensional colloidal crystal," or a precisely ordered layer of particles. This is a critical step toward growing three-dimensional crystals for use in optical technologies, said You-Yeon Won, an assistant professor of chemical engineering.

"Making the first layer is very difficult, so we have taken an important step in the right direction," Won said. "Creating three-dimensional structures poses a big challenge, but I think it's feasible".

Findings were detailed in a paper appearing online April 9 in the journal Soft Matter, published by the Royal Society of Chemistry in the United Kingdom. The paper was written by graduate student Jaehyun Hur and Won......... Posted by: Kevin      Read more         Source

April 22, 2008, 8:54 PM CT

Rewrite Fossil History Of Shell-breaking Crab

While waiting for colleagues at a small natural history museum in the state of Chiapas, Mexico last year, Cornell paleontologist Greg Dietl chanced upon a discovery that has helped rewrite the evolutionary history of crabs and the shelled mollusks upon which they preyed.

In a museum display case he recognized a 67- to 69-million-year-old fossil from the Late Cretaceous period of a big crab with an oversized right claw. Such crabs with claws of different sizes were not known to exist until the early Cenozoic era, about 20 million years later. Aside from being larger than most known Late Cretaceous crabs (about the size of today's Florida stone crabs) and having asymmetrical claws, this ancient crab also sported a curved tooth on the movable finger of the larger right claw. This was another specialized adaptation that paleontologists thought developed millions of years later for peeling snail shells open.

"I immediately had to point it out to my colleagues around me," said Dietl, an adjunct professor in Cornell's Department of Earth and Atmospheric Sciences and director of collections at the Cornell-affiliated Paleontological Research Institution in Ithaca. "I was really excited when I found it. The fossil re-opens the question of the role crabs played in the well-documented restructuring of marine communities that occurred during the Mesozoic era [251 million years ago to 65 million years ago]."........ Posted by: William      Read more         Source

April 21, 2008, 8:21 PM CT

The Antarctic deep sea gets colder

The Antarctic deep sea gets colder, which might stimulate the circulation of the oceanic water masses. This is the first result of the Polarstern expedition of the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association that has just ended in Punta Arenas/Chile. At the same time satellite images from the Antarctic summer have shown the largest sea-ice extent on record. In the coming years autonomous measuring buoys will be used to find out whether the cold Antarctic summer induces a new trend or was only a "slip".

The Polarstern expedition ANT-XXIV/3 was dedicated to examining the oceanic circulation and the oceanic cycles of materials that depend on it. Core themes were the projects CASO (Climate of Antarctica and the Southern Ocean) and GEOTRACES, two of the main projects in the Antarctic in the International Polar Year 2007/08.

Under the direction of Dr. Eberhard Fahrbach, Oceanographer at the Alfred Wegener Institute, 58 researchers from ten countries were on board the research vessel Polarstern in the Southern Ocean from 6 February until 16 April, 2008. They studied ocean currents as well as the distribution of temperature, salt content and trace substances in Antarctic sea water. „We want to investigate the role of the Southern Ocean for past, present and future climate," chief scientist Fahrbach said. The sinking water masses in the Southern Ocean are part of the overturning in this region and thus play a major role in global climate. „While the last Arctic summer was the warmest on record, we had a cold summer with a sea-ice maximum in the Antarctic. The expedition shall form the basis for understanding the opposing developments in the Arctic and in the Antarctic," Fahrbach said......... Posted by: Tyler      Read more         Source

April 21, 2008, 8:05 PM CT

Arctic Ice More Vulnerable to Sunny Weather

The shrinking expanse of Arctic sea ice is increasingly vulnerable to summer sunshine, new research concludes. The study, by researchers at the National Center for Atmospheric Research (NCAR) and Colorado State University (CSU), finds that uncommonly sunny weather contributed to last summer's record loss of Arctic ice, while similar weather conditions in past summers do not appear to have had comparable impacts.

The study, which draws on observations from instruments on a new group of NASA satellites known as the "A-Train," will be published tomorrow in Geophysical Research Letters. It was funded by NASA and the National Science Foundation, which is NCAR's principal sponsor.

"In a warmer world, the thinner sea ice is becoming increasingly sensitive to year-to-year variations in weather and cloud patterns," says NCAR's Jennifer Kay, the lead author. "A single uncommonly clear summer can now have a dramatic impact".

The findings indicate that summer sunshine in the Arctic produces more pronounced melting than in the past, largely because there is now less ice to reflect solar radiation back into space. As a result, the presence or absence of clouds now has greater implications for sea ice loss.

Satellite data offer clues to record-shattering 2007 melt........ Posted by: Tyler      Read more         Source

April 21, 2008, 6:17 PM CT

How climate change impacts food production

The old adage, We are what we eat, may be the latest recipe for success when it comes to curbing the perils of global climate warming. Despite the recent popular attention to the distance that food travels from farm to plate, aka food miles, Carnegie Mellon scientists Christopher L. Weber and H. Scott Matthews argue in an upcoming article in the prestigious Environmental Science & Technology journal that it is dietary choice, not food miles, which most determines a households food-related climate impacts.

Our analysis shows that despite all the attention given to food miles, the distance that food travels is only around 11% of the average American households food-related greenhouse gas emissions, said Weber, a research professor in Carnegie Mellons department of civil and environmental engineering and engineering and public policy.

The scientists report that fruit, vegetables, meat and milk produced closer to home rack up fewer petroleum-based transport miles than foods trucked cross country to your table. Yet despite the large distances involvedthe average distance traveled for food in the U.S. is estimated at 4,000-5,000 miles the large non-energy based greenhouse gas emissions linked to producing food make food production matter much more than distance traveled......... Posted by: Tyler      Read more         Source

April 17, 2008, 7:33 PM CT

Dam removal increases property values

Two new studies appearing in Contemporary Economic Policy explore the impact of dam removal on local property values and find that property values increase after dams are removed.

Lynne Y. Lewis, Ph.D., of Bates College and scientists utilized geographic information systems mapping software to examine the effects of small hydropower dams on property values in Maine. The study examined the effects on property values of the Edwards dam in Augusta which was removed in 1999, as well as two other existing dams located elsewhere on the Kennebec River.

The study observed that there is a penalty for being near the dam sites. Properties near the dams have lower value than properties further away. However, this penalty has shrunk substantially since the removal of Edwards Dam. The penalty for being close to the two existing dams is approximately three times larger than the penalty for being close to the site of the former Edwards Dam.

Removal of the Edwards dam has also had significant positive effects on fisheries and recreational value of the Kennebec River. Since its removal, commercially important fish have returned to the river above the dam site. Recreation on the river including fly fishing, canoeing, and kayaking has also increased.

A study led by Bill Provencher, Ph.D. of the University of Wisconsin-Madison also examined the impact of small dam removal on property values. His work focused on small dam removal in south-central Wisconsin. The study applied statistical techniques to market sales data to determine the relative contribution to property values. The results are quite similar to those found by Lewis. Residential property by a river but not by a dam is more valuable than identical property located by a dam......... Posted by: Tyler      Read more         Source

April 10, 2008, 9:27 PM CT

How strong is a hurricane?

Knowing how powerful a hurricane is, before it hits land, can help to save lives or to avoid the enormous costs of an unnecessary evacuation. Some MIT scientists think there may be a better, cheaper way of getting that crucial information.

So far, there's only one surefire way of measuring the strength of a hurricane: Sending airplanes to fly right through the most intense winds and into the eye of the storm, carrying out wind-speed measurements as they go.

That's an expensive approach--the specialized planes used for hurricane monitoring cost about $100 million each, and a single flight costs about $50,000. Monitoring one approaching hurricane can easily require a dozen such flights, and so only storms that are approaching U.S. shores get such monitoring, even though the strongest storms occur in the Pacific basin (where they are known as tropical cyclones).

Nicholas Makris, associate professor of mechanical and ocean engineering and director of MIT's Laboratory for Undersea Remote Sensing, thinks there may be a better way. By placing hydrophones (underwater microphones) deep below the surface in the path of an oncoming hurricane, it's possible to measure wind power as a function of the intensity of the sound. The roiling action of the wind, churning up waves and turning the water into a bubble-filled froth, causes a rushing sound whose volume is a direct indicator of the storm's destructive power......... Posted by: Tyler      Read more         Source