September 29, 2008, 10:25 PM CT

New meat-eating dinosaur from Argentina

ArgentinaThe remains of a new 10-meter-long predatory dinosaur discovered along the banks of Argentina's Rio Colorado is helping to unravel how birds evolved their unusual breathing system.

Paleontologists led by the University of Chicago's Paul Sereno, a National Geographic Explorer-in-Residence, will publish their discovery Sept. 29 in the online journal Public Library of Science ONE. Joining Sereno to announce the discovery at a news conference in Mendoza, Argentina, today were Ricardo Martinez and Oscar Alcober, both of the Universidad Nacional de San Juan, Argentina.

The discovery of this dinosaur builds on decades of paleontological research indicating that birds evolved from dinosaurs.

"Among land animals, birds have a unique way of breathing. The lungs actually don't expand," Sereno said. Instead, birds have developed a system of bellows, or air sacs, which help pump air through the lungs. It's the reason birds can fly higher and faster than bats, which, like all mammals, expand their lungs in a less efficient breathing process.

Discovered by Sereno and colleagues in 1996, the new dinosaur is named Aerosteon riocoloradensis ("air bones from the Rio Colorado"). "Aerosteon, found in rocks dating to the.

Cretaceous period about 85 million years old, represents a lineage surviving in isolation in South America. Its closest cousin in North American, Allosaurus, had gone extinct millions of years earlier and was replaced by tyrannosaurs"......... Posted by: William      Read more         Source

September 29, 2008, 10:15 PM CT

Sounds travel farther underwater

It is common knowledge that the world's oceans and atmosphere are warming as humans release more and more carbon dioxide into the Earth's atmosphere. However, fewer people realize that the chemistry of the oceans is also changing-seawater is becoming more acidic as carbon dioxide from the atmosphere dissolves in the oceans. As per a paper would be published this week by marine chemists at the Monterey Bay Aquarium Research Institute, these changes in ocean temperature and chemistry will have an unexpected side effect-sounds will travel farther underwater.

Conservative projections by the Intergovernmental Panel on Climate Change (IPCC) suggest that the chemistry of seawater could change by 0.3 pH units by 2050 (see below for background information on pH and ocean acidification). In the October 1, 2008 issue of Geophysical Research Letters, Keith Hester and his coauthors calculate that this change in ocean acidity would allow sounds to travel up to 70 percent farther underwater. This will increase the amount of background noise in the oceans and could affect the behavior of marine mammals.

Ocean chemists have known for decades that the absorption of sound in seawater changes with the chemistry of the water itself. As sound moves through seawater, it causes groups of atoms to vibrate, absorbing sounds at specific frequencies. This involves a variety of chemical interactions that are not completely understood. However the overall effect is strongly controlled by the acidity of the seawater. The bottom line is the more acidic the seawater, the less low- and mid-frequency sound it absorbs......... Posted by: Kevin      Read more         Source

September 28, 2008, 9:09 PM CT

Looking for water on Mars

NASA's Phoenix Scout Lander reached Mars on May 25,, opened a soils lab, and started looking for water. Phoenix uses a robotic scoop arm to deliver regolith samples to the suite of instruments aboard the Lander--with one exception. The thermal and electrical conductivity probe designed by a team of research researchers at Decagon Devices Inc. is actually mounted on the robotic arm and makes direct contact with the regolith. It measures thermal conductivity, thermal diffusivity, electrical conductivity, and dielectric permittivity of the regolith, as well as vapor pressure of the air.

Finding Water, Building Climate Models

Phoenix uses the probe to look for evidence of water on Mars and to determine thermal properties of the regolith for use in climate models. The data collected so far await analysis, but the numbers look intriguing and promising not just for Mars study but here on earth.

Fat Needle Challenge

Logistical challenges early on forced the Decagon team to look for flexibility in the transient heated needle technique in order to build a successful thermal properties analyzer for Mars. Phoenix's robotic arm can't insert the needles as gently as a human hand. Long, thin needles approximating an infinitely long line heat source as mandatory by the model were likely to snap when inserted into a surface of unknown hardness. The best alternative design featured stubby, conical needles which violated the assumptions of the transient heated needle theory......... Posted by: Brooke      Read more         Source

September 25, 2008, 10:16 PM CT

MIT solves 100-year-old engineering problem

As a car accelerates up and down a hill then slows to follow a hairpin turn, the airflow around it cannot keep up and detaches from the vehicle. This aerodynamic separation creates additional drag that slows the car and forces the engine to work harder. The same phenomenon affects airplanes, boats, submarines, and even your golf ball.

Now, in work that could lead to ways of controlling the effect with potential impacts on fuel efficiency and more, MIT researchers and his colleagues have reported new mathematical and experimental work for predicting where that aerodynamic separation will occur.

The research solves "a century-old problem in the field of fluid mechanics," or the study of how fluids -- which for researchers include gases and liquids -- move, said George Haller, a visiting professor in the Department of Mechanical Engineering. Haller's group developed the new theory, while Thomas Peacock, the Atlantic Richfield Career Development Associate Professor in the same department, led the experimental effort.

Papers on the experiments and theory are being reported in the Sept. 25 issue of the Journal of Fluid Mechanics and in the recent issue of Physics of Fluids, respectively.

Fluid flows affect everything in our world, from blood flow to geophysical convection. As a result, engineers constantly seek ways of controlling separation in those flows to reduce losses and increase efficiency. One recent accomplishment: the sleek, full-body swimsuits used at the Beijing Olympics......... Posted by: Kevin      Read more         Source

September 18, 2008, 9:14 PM CT

From Sugar to Gasoline

Following independent paths of investigation, two research teams are announcing this month that they have successfully converted sugar-potentially derived from agricultural waste and non-food plants-into gasoline, diesel, jet fuel and a range of other valuable chemicals.

Chemical engineer Randy Cortright and colleagues at Virent Energy Systems of Madison, Wisc., a National Science Foundation (NSF) Small Business Innovation Research awardee, and scientists led by NSF-supported chemical engineer James Dumesic of the University of Wisconsin at Madison are now announcing that sugars and carbohydrates can be processed like petroleum into the full suite of products that drive the fuel, pharmaceutical and chemical industries.

"NSF and other federal funding agencies are advocating the new paradigm of next generation hydrocarbon biofuels," said John Regalbuto, director of the Catalysis and Biocatalysis Program at NSF and chair of an interagency working group on biomass conversion. "Even when solar and wind, in addition to clean coal and nuclear, become highly developed, and cars become electric or plug-in hybrid, we will still need high energy-density gasoline, diesel and jet fuel for planes, trains, trucks, and boats. The processes that these teams developed are superb examples of pathways that will enable the sustainable production of these fuels"......... Posted by: Kevin      Read more         Source

September 18, 2008, 8:51 PM CT

On the Threshold of Abrupt Climate Changes

Abrupt climate change is a potential menace that hasn't received much attention. That's about to change. Through its Climate Change Prediction Program, the U.S. Department of Energy's Office of Biological and Environmental Research (OBER) recently launched IMPACTS - Investigation of the Magnitudes and Probabilities of Abrupt Climate Transitions - a program led by William Collins of Berkeley Lab's Earth Sciences Division (ESD) that brings together six national laboratories to attack the problem of abrupt climate change, or ACC.

Sparked by the 2007 Nobel Peace Prize that was shared by Al Gore and the Intergovernmental Panel on Climate Change (IPCC), the reality of global warming finally got through to the majority of the world's population. Most people think of climate change as something that occurs only gradually, however, with average temperature changing two or three degrees Celsius over a century or more; this is the rate at which 'forcing' mechanisms operate, such as the accumulation of carbon dioxide in the atmosphere due to the burning of fossil fuels or widespread changes in land use.

........ Posted by: Tyler      Read more         Source

September 14, 2008, 10:26 PM CT

Curbing coal emissions alone might avert climate danger

An ongoing rise in atmospheric carbon dioxide from burning of fossil fuels might be kept below harmful levels if emissions from coal are phased out within the next few decades, say researchers. They say that less plentiful oil and gas should be used sparingly as well, but that far greater supplies of coal mean that it must be the main target of reductions. Their study appears in the journal Global Biogeochemical Cycles

The burning of fossil fuels accounts for about 80 percent of the rise of atmospheric CO₂ since the pre-industrial era, to its current level of 385 parts per million. However, while there are huge amounts of coal left, predictions about when and how oil and gas production might start running out have proved controversial, and this has made it difficult to anticipate future emissions. To better understand how the emissions might change in the future, climatologist Pushker Kharecha and director James Hansen of NASA Goddard Institute for Space Studiesa member of Columbia University's Earth Institute--considered a wide range of scenarios.

"This is the first paper that explicitly melds the two vital issues of global peak oil production and human-induced climate change," Kharecha said. "We observed that because coal is much more plentiful than oil or gas, reducing coal emissions is absolutely essential to avoid dangerous climate change." Kharecha is also author of a related article, "How Will the End of Cheap Oil Affect Future Global Climate?"......... Posted by: Tyler      Read more         Source

September 14, 2008, 10:06 PM CT

Slicing solar power costs

University of Utah engineers devised a new way to slice thin wafers of the chemical element germanium for use in the most efficient type of solar power cells. They say the new method should lower the cost of such cells by reducing the waste and breakage of the brittle semiconductor.

The expensive solar cells now are used mainly on spacecraft, but with the improved wafer-slicing method, "the idea is to make germanium-based, high-efficiency solar cells for uses where cost now is a factor," especially for solar power on Earth, says Eberhard "Ebbe" Bamberg, an assistant professor of mechanical engineering. "You want to do it on your roof".

Dinesh Rakwal, a doctoral student in mechanical engineering, adds: "We're coming up with a more efficient way of making germanium wafers for solar cells to reduce the cost and weight of these solar cells and make them defect-free".

Bamberg and Rakwal are publishing their findings in the Journal of Materials Processing Technology Their study has been accepted, and a final version will be published online late this month or in early October, and in print in 2009.

Brass-coated, steel-wire saws now are used to slice round wafers of germanium from cylindrical single-crystal ingots. But the brittle chemical element cracks easily, requiring broken pieces to be recycled, and the width of the saws means a significant amount of germanium is lost during the cutting process. The sawing method was developed for silicon wafers, which are roughly 100 times stronger......... Posted by: Kevin      Read more         Source

September 11, 2008, 9:15 PM CT

As good as it gets?

AAlbert Einstein once quipped, "Reality is merely an illusion, albeit a very persistent one." The famous scientist might have added that the illusion of reality shifts over time. As per a new Brandeis University study in the recent issue of Psychological Science, age influences how we perceive the future. When thinking about the future, some people seem pessimistic, while others' optimism seems to border on fantasy. Whether a person is naturally a pessimist or an optimist, the study suggests there are other factors at work in determining the way people consider how satisfying their future lives may be.

Brandeis University psychology expert Margie Lachman along with Christina Rcke, University of Zurich, Christopher Rosnick, Southern Illinois University, and Carol Ryff, University of Wisconsin, wanted to see if there were differences in actual and perceived ratings of how satisfied Americans were with their lives over a nine-year period. To test this idea, the scientists conducted two surveys, the first in 1995-1996, and the second nine years later, between 2004 and 2006.

In the first survey, participants (between the ages of 24-74) completed a telephone interview and questionnaire. They were asked to rate how currently satisfied they were with their lives, how satisfied they were with their lives 10 years earlier and how satisfied they expected to be 10 years later. In 2004, the participants were asked those same questions......... Posted by: Sarah      Read more         Source

September 10, 2008, 8:50 PM CT

Maths aids mayonnaise production

The subject of 'gas bubbles in liquids' has a number of applications in industry. Examples include separating oil from water in the oil industry, how ink drops behave in printers and the manufacture of products in the food industry, such as mayonnaise. 'This subject of course also applies to natural processes such as rainfall and boiling water,' PhD student Jok Tang adds.



Experiments

Industry benefits from knowing how a current with bubbles behaves. This knowledge enables production processes to be improved. Until now, in spite of ever more powerful computers, it has proved difficult to calculate the behaviour of currents with bubbles properly. Computers mandatory too much time to solve the corresponding mathematical equations.

To gain insight into current behaviour, researchers generally conduct small-scale experiments. 'But,' Tang says, 'these experiments are expensive and difficult to perform.'.



Quick

'We think that our method will be adopted by industry in the not too distant future. Not just because the need for this method becomes greater when calculating larger-scale problems, but mainly because it is quicker and cheaper than the methods used now,' Tang explains......... Posted by: Sarah      Read more         Source

September 10, 2008, 6:48 PM CT

First beam for Large Hadron Collider

An international collaboration of researchers today sent the first beam of protons zooming at nearly the speed of light around the 17-mile-long underground circular path of the Large Hadron Collider (LHC), the world's most powerful particle accelerator, located at the CERN laboratory near Geneva, Switzerland.

The researchers also accelerated a second beam of protons through the path in the opposite direction, the goal being head-on collisions of protons that can offer clues to the origin of mass and new forces and particles in the universe. The second beam made one turn around the LHC.

Celebrations across the United States and around the world mark the LHC's first circulating beams, an occasion more than 15 years in the making. An estimated 10,000 people from 60 countries have helped design and build the accelerator and its massive particle detectors, including more than 1,700 scientists, engineers, students and technicians from 94 U.S. universities and laboratories supported by the U.S. Department of Energy Office of Science and the National Science Foundation.

UCR faculty Robert Clare, John Ellison, J. William Gary, Gail Hanson and Stephen Wimpenny, along with postdoctoral researchers and graduate students are involved in the LHC's Compact Muon Solenoid (CMS) experiment, a large particle-capturing detector whose discoveries are expected to help answer questions such as: Are there undiscovered principles of nature? What is the origin of mass? Do extra dimensions exist? What is dark matter? How can we solve the mystery of dark energy? And how did the universe come to be?........ Posted by: Kevin      Read more         Source

September 9, 2008, 9:20 PM CT

Physicists harness effects of disorder in magnetic sensors

University of Chicago researchers have discovered how to make magnetic sensors capable of operating at the high temperatures that ceramic engines in cars and aircraft of the future will require.

The key to fabricating the sensors involves slightly degrading samples of a well-known semiconductor material, called indium antimonide, which is valued for its purity. Chicago's Thomas Rosenbaum and associate Jingshi Hu, now of the Massachusetts Institute of Technology, have published their formula in the recent issue of the journal Nature Materials

Most magnetic sensors operate by detecting how a magnetic field alters the path of an electron. Conventional sensors lose this capability when subjected to temperatures reaching hundreds of degrees. Not so in the indium antimonide magnetosensors that Rosenbaum and Hu developed with support from the U.S. Department of Energy.

"This sensor would be able to function in those sorts of temperatures without any degradation," said Rosenbaum, the John T. Wilson Distinguished Service Professor in Physics.

Rosenbaum's research typically focuses on the properties of materials observed at the atomic level when subjected to temperatures near absolute zero (minus-460 degrees Fahrenheit). More than a decade ago, he led a team of researchers in experiments involving silver selenide and silver telluride, two materials that exhibited no magnetic response at low temperatures. But when the team introduced a tiny amount of silver (one part in 10,000) to the materials, their magnetic response skyrocketed......... Posted by: Sarah      Read more         Source

September 2, 2008, 7:28 PM CT

Scientists grow 'nanonets' able to snare added energy transfer

Using two abundant and relatively inexpensive elements, Boston College chemists have produced nanonets, a flexible webbing of nano-scale wires that multiplies surface area critical to improving the performance of the wires in electronics and energy applications.

Scientists grew wires from titanium and silicon into a two-dimensional network of branches that resemble flat, rectangular netting, Assistant Professor of Chemistry Professor Dunwei Wang and his team report in the international edition of the German Chemical Society journal Angewandte Chemie

By creating nanonets, the team conquered a longstanding engineering challenge in nanotechnology: creating a material that is extremely thin yet maintains its complexity, a structural design large or long enough to efficiently transfer an electrical charge.

"We wanted to create a nano structure unlike any other with a relatively large surface area," said Wang. "The goal was to increase surface area and maintain the structural integrity of the material without sacrificing surface area and thereby improving performance".

Tests showed an improved performance in the material's ability to conduct electricity through high quality connections of the nanonet, which suggest the material could lend itself to applications from electronics to energy-harvesting, Wang said. Titanium disilicide (TiSi2) has been proven to absorb light across a wide range of the solar spectrum, is easily obtained, and is inexpensive. Metal silicides are also found in microelectronics devices......... Posted by: Kevin      Read more         Source

August 31, 2008, 8:59 PM CT

To make maths teaching more rigorous and inspiring

An attempt to re-energise mathematics teaching in Europe is being made in a new project examining a range of factors thought to influence achievement. Mathematics teaching is as vital as ever both in support of key fields such as life sciences, alternative energy development, or information technology, and also through its unique ability to develop widely applicable problem solving skills. It should be highly relevant not just for the elite few but for all people in education.

The new project was discussed at a recent workshop organised by the European Science Foundation (ESF), which brought together experts in different areas of mathematics education. "It was agreed that we would begin the process of developing a comparative project, involving between fifteen and twenty European countries, to examine the interrelatedness of the mathematics-related beliefs of teachers and students, teacher practices and student cognition," said Paul Andrews, the workshop's convenor and Senior Lecturer in Education at the Faculty of Education of Cambridge University in the UK.

Andrews pointed out that the solution to the mathematics teaching conundrum was complex and multi-dimensional, just like a number of of the great problems in the field itself. On the one hand, enthusiasm needed to be balanced with rigour in order to motivate students while also teaching skills and knowledge worth acquiring. "To assume that the development of enthusiasm is sufficient to guarantee achievement would be nave as there are countries in which students have little enthusiasm for mathematics but achieve relatively highly and, of course, vice versa," pointed out Andrews......... Posted by: Jaison      Read more         Source

August 31, 2008, 8:26 PM CT

Increased Greenland ice melt and sea level rise

Scientists have yet to reach a consensus on how much and how quickly melting of the Greenland Ice Sheet will contribute to sea level rise. To shed light on this question, researchers at the University of Wisconsin and Columbia University's Center for Climate Systems Research analyzed the disappearance of the Laurentide Ice Sheet, the last ice sheet to melt completely in the Northern Hemisphere and the closest example of what can be expected to happen to the Greenland Ice Sheet in the next century. Their findings show that sea level rise as a result of ice sheet melt can happen very rapidly. The study will be published online this week in Nature Geoscience..

"We have never seen an ice sheet retreat significantly or even disappear before, yet this may happen for the Greenland Ice Sheet in the coming centuries to millennia," said Anders Carlson, the study's lead author and assistant professor of geology and geophysics at the University of Wisconsin-Madison. "What we don't know is the rate of melting of the Greenland Ice Sheet. The geologic data we compiled on the retreat history of the Laurentide Ice Sheet, however, gives us a window into how fast these large blocks of ice can melt and raise sea level".

There are two challenges to determining the rate of melt for the Greenland Ice Sheeta terrestrial ice mass covering more than 1.7 million km. The current rate of sea level rise is ~ 3 mm/year. In its Fourth Assessment Report, the Intergovernmental Panel on Climate Change (IPCC) indicated up to 59 cm of sea level rise, and stated that, if the observed contributions from the Greenland and Antarctic Ice Sheets between 1992 and 2003 were to increase in direct parallel with global average temperature change, the upper ranges of sea-level rise would increase by 10 to 20 cm. This prediction, however, is based on data collected in a very short period of timemostly from the last decadeand is not enough to give a clearer idea about what might happen to the Greenland Ice Sheet......... Posted by: Tyler      Read more         Source

August 27, 2008, 6:47 PM CT

Yellowstone's Ancient Supervolcano

The geysers of Yellowstone National Park owe their eistence to the "Yellowstone hotspot"--a region of molten rock buried deep beneath Yellowstone, geologists have found.

But how hot is this "hotspot," and what's causing it?

In an effort to find out, Derek Schutt of Colorado State University and Ken Dueker of the University of Wyoming took the hotspot's temperature.

The researchers published results of their research, funded by the National Science Foundation (NSF)'s division of earth sciences, in the August, 2008, issue of the journal Geology.

"Yellowstone is located atop of one of the few large volcanic hotspots on Earth," said Schutt. "But though the hot material is a volcanic plume, it's cooler than others of its kind, such as one in Hawaii".

When a supervolcano last erupted at this spot more than 600,000 years ago, its plume covered half of today's United States with volcanic ash. Details of the cause of the Yellowstone supervolcano's periodic eruptions through history are still unknown.

Thanks to new seismometers in the Yellowstone area, however, researchers are obtaining new data on the hotspot.

Past research observed that in rocks far beneath southern Idaho and northwestern Wyoming, seismic energy from distant earthquakes slows down considerably......... Posted by: Tyler      Read more         Source

August 27, 2008, 6:44 PM CT

Proteins Have Controlled Motions

Iowa State University researcher Robert Jernigan believes that his research shows proteins have controlled motions.

Most biochemists traditionally believe proteins have a number of random, uncontrolled movements.

Research conducted by Jernigan, director of the L.H. Baker Center for Bioinformatics and Biological Statistics together with Guang Song, an assistant professor in computer science and graduate student Lei Yang, over a 10-year period shows that not only are protein motions more restricted, but also that these restricted, controlled motions are part of the function of the proteins.

The group's findings were recently reported in the journal "Structure".

Using as an example a protein from HIV virus, Jernigan conducted his research using a simple model and tested to see how the proteins moved. The large number of reported structures show exactly the motions that are mandatory for their function, and exactly the same motions as computed by Jernigan's model.

"This is one experimental case that is indicative, but there are a number of others," he said.

Jernigan believes this research is the first step to better understanding proteins and cell behaviors.

"There is the possibility of creating designer drugs with this newly discovered information," he said......... Posted by: Sarah      Read more         Source

August 21, 2008, 8:19 PM CT

Earthquakes may endanger New York

A study by a group of prominent seismologists suggests that a pattern of subtle but active faults makes the risk of earthquakes to the New York City area substantially greater than formerly believed. Among other things, they say that the controversial Indian Point nuclear power plants, 24 miles north of the city, sit astride the previously unidentified intersection of two active seismic zones. The paper appears in the current issue of the Bulletin of the Seismological Society of America at http://www.bssaonline.org/cgi/reprint/98/4/1696.

A number of faults and a few mostly modest quakes have long been known around New York City, but the research casts them in a new light. The researchers say the insight comes from sophisticated analysis of past quakes, plus 34 years of new data on tremors, most of them perceptible only by modern seismic instruments. The evidence charts unseen but potentially powerful structures whose layout and dynamics are only now coming clearer, say the scientists. All are based at Columbia University's Lamont-Doherty Earth Observatory, which runs the network of seismometers that monitors most of the northeastern United States: http://www.ldeo.columbia.edu/LCSN/.

Lead author Lynn R. Sykes said the data show that large quakes are infrequent around New York in comparison to more active areas like California and Japan, but that the risk is high, because of the overwhelming concentration of people and infrastructure. "The research raises the perception both of how common these events are, and, specifically, where they may occur," he said. "It's an extremely populated area with very large assets." Sykes, who has studied the region for four decades, is known for his early role in establishing the global theory of plate tectonics......... Posted by: Tyler      Read more         Source

August 20, 2008, 6:32 PM CT

Creating unconventional metals

The semiconductor silicon and the ferromagnet iron are the basis for much of mankind's technology, used in everything from computers to electric motors. In this week's issue of the journal Nature (August 21st) an international group of scientists, including academic and industrial scientists from the UK, USA and Lesotho, report that they have combined these elements with a small amount of another common metal, manganese, to create a new material which is neither a magnet nor an ordinary semiconductor. The paper goes on to show how a small magnetic field can be used to switch ordinary semiconducting behaviour (such as that seen in the electronic-grade silicon which is used to make transistors) back on.

The new material exists in a quantum halfway house between magnet and semiconductor - in the same way that much more complex materials such as ceramics which exhibit high temperature superconductivity exist in quantum halfway houses between metals and magnetic insulators. The research is of fundamental importance because it demonstrates, for the first time, a simple recipe for reaching this halfway house, whilst also suggesting new mechanisms for controlling electrical currents and magnetism in semiconductor devices.

Professor J.F. DiTusa of Louisiana State University and a co-author of the paper said: "It's amazing that something which was thought to exist theoretically in mathematical physics could actually be found in an alloy which was simply formed by melting together a few common elements"......... Posted by: Sarah      Read more         Source

August 20, 2008, 5:47 PM CT

Research Agenda For Environmental Mercury

Embracing the belief that an interdisciplinary and coordinated research agenda can have a profound impact on advancing science and influencing policy, a group of experts has developed a roadmap for improving our understanding of how mercury moves through the marine ecosystem and into the fish we eat.

Members of Dartmouth's Toxic Metals Research Program convened the group of 43 leading scientists, environmental regulators, and public health experts in November 2006 to set priorities for a research and biomonitoring agenda that can inform environmental regulation and public health policy. Their report is reported in the current issue of the journal Environmental Health Perspectives.

The group put a priority on monitoring and research across habitats with an integrated approach that considers the poorly understood links among marine sources, biotransfer processes, and bioaccumulation mechanisms that put humans at risk of exposure to mercury. For example, one unanswered question: does the toxic form of mercury produced and bioaccumulated in coastal ecosystems end up in fish such as tuna caught in the open ocean?

"We are intimately connected to the ocean ecosystem," says Celia Chen, a research associate professor of biology at Dartmouth and the lead author of the paper. "For example, seafood is one of the few wild foods still consumed by large numbers of people. Though we know that the mercury found in marine fish and shellfish poses a threat to humans - not to mention the ecosystem itself - we know very little about the physical and geochemical processes that link mercury in the atmosphere to the toxic form found in seafood"......... Posted by: Tyler      Read more         Source

August 20, 2008, 4:55 PM CT

Continued Breakup Of Two Of Greenland's Largest Glaciers

Scientists monitoring daily satellite images here of Greenland's glaciers have discovered break-ups at two of the largest glaciers in the last month.

They expect that part of the Northern hemisphere's longest floating glacier will continue to disintegrate within the next year.

A massive 11-square-mile (29-square-kilometer) piece of the Petermann Glacier in northern Greenland broke away between July 10th and by July 24th. The loss to that glacier is equal to half the size of Manhattan Island. The last major ice loss to Petermann occurred when the glacier lost 33 square miles (86 square kilometers) of floating ice between 2000 and 2001.

Petermann has a floating section of ice 10 miles (16 kilometers) wide and 50 miles (80.4 kilometers) long which covers 500 square miles (1,295 square kilometers).

What worries Jason Box, an associate professor of geography at Ohio State, and colleagues, graduate students Russell Benson and David Decker, all with the Byrd Polar Research Center, even more about the latest images is what appears to be a massive crack further back from the margin of the Petermann Glacier.

That crack may signal an imminent and much larger breakup.

"If the Petermann glacier breaks up back to the upstream rift, the loss would be as much as 60 square miles (160 square kilometers)," Box said, representing a loss of one-third of the massive ice field......... Posted by: Tyler      Read more         Source

August 20, 2008, 1:34 AM CT

Controlling the behavior of quantum dots

Scientists from the National Institute of Standards and Technology (NIST) and the Joint Quantum Institute (JQI), a collaborative center of the University of Maryland and NIST, have reported a new way to fine-tune the light coming from quantum dots by manipulating them with pairs of lasers. Their technique, published in Physical Review Letters,* could significantly improve quantum dots as a source of pairs of entangled photons, a property with important applications in quantum information technologies. The accomplishment could accelerate development of powerful advanced cryptography applications, projected to be a key 21st-century technology.

Entangled photons are a peculiar consequence of quantum mechanics. Tricky to generate, they remain interconnected even when separated by large distances. Merely observing one instantaneously affects the properties of the other. The entanglement can be used in quantum communication to pass an encryption key that is by its nature completely secure, as any attempt to eavesdrop or intercept the key would be instantly detected. One goal of the NIST-JQI team is to develop quantum dots as a convenient source of entangled photons.

Quantum dots are nanoscale regions of a semiconductor material similar to the material in computer processors but with special properties due to their tiny dimensions. Though they can be composed of tens of thousands of atoms, quantum dots in a number of ways behave almost as if they were single atoms. Unfortunately, almost is not good enough when it comes to the fragile world of quantum cryptography and next-generation information technologies. When energized, a quantum dot emits photons, or particles of light, just as a solitary atom does. But imperfections in the shape of a quantum dot cause what should be overlapping energy levels to separate. This ruins the delicate balance of the ideal state mandatory to emit entangled photons......... Posted by: Kevin      Read more         Source

August 13, 2008, 1:00 AM CT

Nano vaccine for hepatitis B shows promise

Chronic hepatitis B infects 400 million people worldwide, a number of of them children. Even with three effective vaccines available, hepatitis B remains a stubborn, unrelenting health problem, particularly in Africa and other developing areas. The disease and its complications cause an estimated 1 million deaths globally each year.

In a number of poor countries, refrigerated conditions mandatory for the current vaccines are costly and hard to come by. It's often difficult in the field to keep needles and syringes sterile. The need to have people return for the three shots currently mandatory also limits success.

Now, a new vaccine that avoids these drawbacks has moved a step closer to human trials. Health scientists hope it will make it possible to immunize large numbers of children and adults in Africa, Asia and South America efficiently and safely.

Researchers at the Michigan Nanotechnology Institute for Medicine and Biological Sciences at the University of Michigan report that a novel, needle-less method for getting an immunity-stimulating agent into the body has proved non-toxic and able to produce strong, sustained immune responses in animal studies. The vaccine is based on a super-fine emulsion of oil, water and surfactants placed in the nose......... Posted by: Sean      Read more         Source

July 23, 2008, 5:00 PM CT

Parasites Outweigh Predators

In a study of parasites living in three estuaries on the Pacific coast of California and Baja California, scientists have determined that biomass of these parasites exceeds that of top predators, in some cases by more than 20 times.

Their findings, which could have significant ecological and biomedical implications, appear in this week's issue of the journal Nature.

Biomass is the amount of living matter that exists in a given habitat. It is expressed either as the weight of organisms per unit area or as the volume of organisms per unit volume of habitat.

Until now, researchers have believed that because parasites are microscopic in size they comprised a small fraction of biomass in a habitat, while free-living organisms such as fish, birds and other predators make up the vast majority.

"We quantified the biomass of free-living and parasitic species in three estuaries and discovered that parasites have substantial biomass in these ecosystems," said Armand Kuris, a zoologist at the University of California at Santa Barbara (UCSB), and a lead author of the paper.

"Parasites have as much, or even more, biomass than other important groups of animals--like birds, fish and crabs," said Ryan Hechinger, a marine scientist at UCSB and co-lead author of the paper......... Posted by: Tyler      Read more         Source

July 22, 2008, 8:15 PM CT

Outflow from World's Largest River

Nutrients from the Amazon River's outflow spread well beyond the continental shelf and drive carbon cycling in the tropical ocean, say researchers who conducted a multi-year study. They will publish their results this week online in the journal Proceedings of the National Academy of Sciences (PNAS).

The scientists discovered a significant and surprising drawdown of carbon dioxide from the atmosphere into the tropical ocean by microorganisms living in the Amazon River's outflow. The finding reveals the surprisingly large role of tropical oceans and major rivers in the oceans' total carbon uptake.

"This work has led to an important discovery about the source of nitrogen that fuels the productivity of tropical ocean waters, particularly those into which large rivers flow," said David Garrison, director of the National Science Foundation (NSF)'s biological oceanography program. NSF's Biocomplexity in the Environment program funded the research.

The Amazon River is the largest river in the world by volume; it also has the largest drainage basin on the planet, accounting for some one fifth of Earth's total river flow. Because of its vast dimensions, it's sometimes called "the river sea".

The Amazon River's outflow covers an area more than twice the size of the state of Texas for several months each year, said Ajit Subramaniam, a biological oceanographer at Columbia University and lead author of the PNAS paper. (Subramaniam is currently on leave from Columbia, now serving as a rotating program director at NSF.)......... Posted by: Tyler      Read more         Source

July 22, 2008, 8:12 PM CT

System to Forecast Flash Floods

People living near vulnerable creeks and rivers along Colorado's Front Range may soon get advance notice of potentially deadly floods, thanks to a new forecasting system being tested this summer by the National Center for Atmospheric Research (NCAR) in Boulder, Colo.

Known as the NCAR Front Range Flash Flood Prediction System, it combines detailed atmospheric conditions with information about stream flows to predict floods along specific streams and catchments.

"The goal is to provide improved guidance about the likelihood of a flash flood event a number of minutes out to an hour or two before the waters start rising," says NCAR scientist David Gochis, one of the developers of the new forecasting system. "We want to increase the lead time of a forecast, while decreasing the uncertainty about whether a flood will occur".

Funding to create the system came from the National Science Foundation (NSF), which is NCAR's sponsor, as well as the National Oceanic and Atmospheric Administration.

"This project is an excellent example of using basic research findings to improve forecasts important to saving lives," said Cliff Jacobs, program director in NSF's Division of Atmospheric Sciences.

The Front Range, because of its steep topography and intense summer storms, is uncommonly vulnerable to summertime flash floods. Such floods have claimed the lives of hundreds of people and accounted for hundreds of millions of dollars in damages throughout the region's history......... Posted by: Tyler      Read more         Source

July 21, 2008, 9:39 PM CT

Key to saving the world's lakes

After completing one of the longest running experiments ever done on a lake, scientists from the University of Alberta, University of Minnesota and the Freshwater Institute, contend that nitrogen control, in which the European Union and a number of other jurisdictions around the world are investing millions of dollars, is not effective and in fact, may actually increase the problem of cultural eutrophication.

The dramatic rise in cultural eutrophicationthe addition of nutrients to a body of water due to human activity that often causes huge algal blooms, fish kills and other problems in lakes throughout the worldhas resulted from increased deposits of nutrients to lakes, largely from human sewage and agricultural wastes.

For 37 years scientists looked at Lake 227, a small lake in the Canadian Shield at the Experimental Lakes Area (ELA) in Ontario, Canada, and examined the best ways to control the cultural eutrophication process of lakes by varying the levels of phosphorous and nitrogen added to the lake.

"What we found goes against the practices of the European Union and a number of researchers around the world," said David Schindler, professor of ecology at the University of Alberta and one of the leading water scientists in the world. "Controlling nitrogen does not correct the polluted lakes, and in fact, may actually aggravate the problem and make it worse"......... Posted by: Tyler      Read more         Source

July 20, 2008, 2:54 PM CT

Saharan dust storms sustain life in Atlantic Ocean

Research at the University of Liverpool has found how Saharan dust storms help sustain life over extensive regions of the North Atlantic Ocean.

Working aboard research vessels in the Atlantic, researchers mapped the distribution of nutrients including phosphorous and nitrogen and investigated how organisms such as phytoplankton are sustained in areas with low nutrient levels.

They observed that plants are able to grow in these regions because they are able to take advantage of iron minerals in Saharan dust storms. This allows them to use organic or 'recycled' material from dead or decaying plants when nutrients such as phosphorous an essential component of DNA in the ocean are low.

Professor George Wolff, from the University's Department of Earth and Ocean Sciences, explains: "We observed that cyanobacteria a type of ancient phytoplankton are significant to the understanding of how ocean deserts can support plant growth. Cyanobacteria need nitrogen, phosphorous and iron in order to grow. They get nitrogen from the atmosphere, but phosphorous is a highly reactive chemical that is scarce in sea water and is not found in the Earth's atmosphere. Iron is present only in tiny amounts in sea water, even though it is one of the most abundant elements on earth......... Posted by: Tyler      Read more         Source

July 17, 2008, 9:32 PM CT

Digital cameras, remote satellites measure crop water demand

Horticultural crops account for almost 50% of crop sales in the United States, and these crops are carefully managed to ensure good quality. But more information is needed about the crops' growth and response to seasonal and climatic changes so that management practices such as irrigation can be precisely scheduled. Existing research can be difficult to generalize because of variations in crops, planting densities, and cultural practices.

Determining growth stage, size, and water needs are particularly important for horticultural crops because most crops are grown in limited water environments and require irrigation. The measurement of "canopy light interception" is a primary means of determining water and irrigation needs. Fractional canopy cover (CC) is a relatively easily measured property that is a good indicator of light interception. Canopy cover, the percent of the soil surface covered by plant foliage, is an important indicator of stage of growth and crop water use in horticultural crops. Methods of using remote sensors to determine canopy cover in major crops have been studied for years, but the studies have not included most horticultural crops.

Thomas J. Trout, Research Leader at the U.S. Department of Agriculture's Agricultural Research Service, along with colleagues from the NASA Earth Science Division, recently published a study that addresses the relationship of remotely sensed normalized difference vegetation index (NDVI) relative to canopy cover of several major horticultural crops in commercial fields......... Posted by: Tyler      Read more         Source

July 17, 2008, 9:23 PM CT

"Nanosculpture" Could Enable New Types of Heat Pumps

A new technique for growing single-crystal nanorods and controlling their shape using biomolecules could enable the development of smaller, more powerful heat pumps and devices that harvest electricity from heat.

Scientists at Rensselaer Polytechnic Institute have discovered how to direct the growth of nanorods made up of two single crystals using a biomolecular surfactant. The scientists were also able to create "branched" structures by carefully controlling the temperature, time, and amount of surfactant used during synthesis.

"Our work is the first to demonstrate the synthesis of composite nanorods with branching, wherein each nanorod consists of two materials - a single-crystal bismuth telluride nanorod core encased in a hollow cylindrical shell of single-crystal bismuth sulfide," said G. Ramanath, professor of materials science and engineering at Rensselaer and director of the university's Center for Future Energy Systems, who led the research project. "Branching and core-shell architectures have been independently demonstrated, but this is the first time that both features have been simultaneously realized through the use of a biomolecular surfactant".

Most nanostructures comprised of a core and a shell generally require more than one step to synthesize, but these new research results demonstrate how to synthesize such nanorods in only one step......... Posted by: Kevin      Read more         Source

July 16, 2008, 7:51 PM CT

A new way to weigh giant black holes

How do you weigh the biggest black holes in the universe? One answer now comes from a completely new and independent technique that astronomers have developed using data from NASA's Chandra X-ray Observatory.

By measuring a peak in the temperature of hot gas in the center of the giant elliptical galaxy NGC 4649, researchers have determined the mass of the galaxy's supermassive black hole. The method, applied for the first time, gives results that are consistent with a traditional technique.

Astronomers have been seeking out different, independent ways of precisely weighing the largest supermassive black holes, that is, those that are billions of times more massive than the Sun. Until now, methods based on observations of the motions of stars or of gas in a disk near such large black holes had been used.

"This is tremendously important work since black holes can be elusive, and there are only a couple of ways to weigh them accurately," said Philip Humphrey of the University of California at Irvine, who led the study. "It's reassuring that two very different ways to measure the mass of a big black hole give such similar answers".

NGC 4649 is now one of only a handful of galaxies for which the mass of a supermassive black hole has been measured with two different methods. In addition, this new X-ray technique confirms that the supermassive black hole in NGC 4649 is one of the largest in the local universe with a mass about 3.4 billion times that of the Sun, about a thousand times bigger than the black hole at the center of our galaxy......... Posted by: Brooke      Read more         Source

July 15, 2008, 9:37 PM CT

For toy-like NASA robots in Arctic, ice research is child's play

Several snowmobiles navigated speedily over arctic ice and snow in Alaska's outback in late June. This scene might seem ordinary except that the recently unveiled snowmobiles are unmanned, autonomous, toy-size robots called SnoMotes the first prototype network of their kind envisioned to rove treacherous areas of the Arctic and Antarctic capturing more accurate measurements that will help researchers better understand what is causing the well-documented melting of ice in those regions.

Ayanna Howard, an associate professor in the School of Electrical and Computer Engineering at the Georgia Institute of Technology in Atlanta, worked with researchers at Pennsylvania State University in State College, Pa., to create the toy-like robots. The robots are designed to traverse terrain often too dangerous for scientists, in pursuit of barometric pressure, temperature, and relative humidity measurements that will help researchers improve climate models. Howard, a former member of NASA's Mars technology program team who developed SmartNav, an autonomous, next-generation Mars rover, believed that science-driven robotics could be just as useful of a vehicle to new discoveries on Earth as it has been in the quest to learn more about Mars.

"After working with robots for the Mars technology program, I thought a similar type of rover could be used to collect multiple science measurements on this planet," said Howard. She is lead on the SnoMotes project funded by the Advanced Information Systems Technology program in NASA's Earth Science Technology Office, a NASA Headquarters office located at Goddard Space Flight Center in Greenbelt, Md......... Posted by: Kevin      Read more         Source