April 6, 2008, 8:29 PM CT

Gunshot residue analysis on a single gunpowder particle

Researchers in Texas are reporting development of an highly dependable, rapid, and inexpensive new method for identifying the presence of gunshot residue (GSR). The test fills a GSR-detection gap that results from wider use of green lead free ammunition.

It requires only a single speck of GSR smaller than the period at the end of this sentence and could boost the accuracy of one of the most widely used tests employed at crime scenes involving gunplay.

In a poster presented here today at the 235th national meeting of the American Chemical Society, graduate student Garrett Lee Burleson and his advisor, chemist Jorn Chi Chung Yu, Ph.D., of Sam Houston State University in Huntsville, described their new method. It extracts almost all components of gunpowder residue from particles about 15 times smaller than the width of a human hair, without the use of chemical reagents. After extraction, gas chromatography coupled with a nitrogen phosphorus detector is used to separate and identify the analytes.

Gunshot residue tests are done in almost every case where a shooting has taken place, Burleson said. The main focus of our research is to develop a method that will help credibility of gunshot residue evidence in court. You can get results with this test in 30 to 40 minutes with the new test. In addition you only need small amounts of evidence to run the test......... Posted by: Sarah      Read more         Source

April 3, 2008, 8:44 PM CT

The voyage to America

Professor Eske Willerslev was surprised by the results of the DNA tests conducted by himself and colleagues on samples of what turned out to be fossilised human faeces found in deep caves in the Oregon desert. The oldest of the droppings have been carbon-dated to be approximately 14,340 years old. Willerslevs faeces samples clearly contain two main genetic types of Asian origin that are unique to present-day North American Indians. Not only is this proof that the American Indians are descendants of the first immigrants to the continent, it is also proof that immigration took place approximately 1,000 years earlier than otherwise believed.

The American continent was the last of the worlds continents to be populated. There are a number of contradictory and more or less well-founded scientific theories on when this occurred and from where the first immigrants came. These theories span from immigration via the icy Atlantic Ocean to Thor Heyerdahls papyrus boat expeditions from Africa to America. The most accepted theory is based on findings of stone tools from the Clovis culture in soil layers dating back to approximately 13,000 BC. As per the theory, people from Siberia migrated, perhaps in search of mammoth, across the land bridge that once connected Siberia and North America. From there, they continued south and spread out across the American continent. The migration passed through a corridor that opened up approximately 14,000 years ago in the giant glacier that covered the American continent. But these new findings call this immigration theory into question......... Posted by: Tyler      Read more         Source

April 1, 2008, 10:19 PM CT

Electricity and gas consumption at a glance

People who want to save energy should always keep an eye on their consumption. The EWE Box offers customers a neat solution: It enables private households to monitor their electricity and gas consumption whenever they want - and save costs thanks to new pricing models.

Once a year, someone from the electricity or gas works comes to read the meter. Soon afterwards, the customer receives an invoice listing the power consumption for the whole year. It does not reveal precisely how much energy the customer has used at what times or with which devices. This has been the situation in the past. In future, however, private households will always be able to check their power consumption - at all times of the day and night.

With the support of the Fraunhofer Application Center System Technology AST, researchers at the Fraunhofer Institute for Solar Energy Systems ISE have developed a new solution in collaboration with Oldenburg-based energy provider EWE. It enables customers to keep track of their current electricity and gas consumption at all times. "The days of 'stupid' meters are over," says ISE project manager Dr. Harald Schäffler. The new metering technologies are intelligent: "The EWE Box is an innovative communication gateway that records and saves the readings from the electricity and gas meters and transmits them to a control center via DSL." This metering and display method - known by experts as 'smart metering' - has a particular advantage: "The power provider can offer the customer individual pricing models, depending on factors such as the load, the time of day or the time of year," explains Schäffler. A different price rate could apply in summer, for instance, when little heating is required, than in winter......... Posted by: Kevin      Read more         Source

April 1, 2008, 9:56 PM CT

Solving Mystery Of Polyketide Drug Formation

A number of top-selling drugs used to treat cancer and lower cholesterol are made from organic compounds called polyketides, which are found in nature but historically difficult for chemists to alter and reproduce in large quantities.

For the first time, researchers at UC Irvine have discovered how polyketides form their ringlike shape, making it easier for chemists to manipulate them into new drugs.

The key, they found, is an enzyme called aromatase/cyclase, which forms a C-shape mold in which polyketides can form one molecule at a time. By changing this mold, chemists can control the size and shape of the polyketide, resulting in the formation of new drugs.

"Almost every polyketide has rings in its chemical structure, and if we can control ring formation, we can produce more polyketide drugs," said Sheryl Tsai, lead author of this study and an assistant professor of molecular biology and biochemistry and chemistry at UCI. "Until now, polyketide ring formation was a mystery that hampered our efforts to produce new drugs".

The research appears online this week in the Proceedings of the National Academy of Sciences.

Polyketide-based drugs and products account for more than $35 billion in sales annually. They include antibiotics that can cure a bacteria infection (tetracycline and erythromycin); anti-cancer drugs used in chemotherapy (doxorubicin and mithramycin); anti-oxidants that help prevent cancer and promote heart strength (EGCG and resverastrol); and drugs that lower cholesterol levels (Zocor). Green tea and red wine also contain beneficial polyketides......... Posted by: Sarah      Read more         Source

April 1, 2008, 9:55 PM CT

356 animal inclusions trapped in 100 million years old opaque amber

Paleontologists from the University of Rennes (France) and the ESRF have found the presence of 356 animal inclusions in completely opaque amber from mid-Cretaceous sites of Charentes (France). The team used the X-rays of the European light source to image two kilogrammes of the fossil tree resin with a technique that allows rapid survey of large amounts of opaque amber. At present this is the only way to discover inclusions in fully opaque amber.

Opaque amber has always been a challenge for paleontologists. Scientists cannot study it because the naked eye cannot visualize the presence of any fossil inclusion inside. In the Cretaceous sites like those in Charentes, there is up to 80% of opaque amber. It is like trying to find, in complete blindness, something that may or may not be there.

However, the paleontologists Malvina Lak, her colleagues from the University of Rennes and the ESRF paleontologist Paul Tafforeau, together with the National Museum of Natural History of Paris, have applied to opaque amber a synchrotron X-ray imaging technique known as propagation phase contrast microradiography. It sheds light on the interior of this dark amber, which resembles a stone to the human eye. "Scientists have tried to study this kind of amber for a number of years with little or no success. This is the first time that we can actually discover and study the fossils it contains", says Paul Tafforeau......... Posted by: William      Read more         Source

April 1, 2008, 9:07 PM CT

Is it a bird, is it a plane, no it's a bridge!

A government lab in Teddington has taken on its biggest sample for analysis to date a 14 tonne foot-bridge.

The National Physical Laboratory (NPL) is a world-leading centre of excellence in developing and applying the most accurate measurement standards, science and technology. For over 100 years it has been the UKs National Measurement Institute and provides highly accurate measurement and analysis for public and private sector benefit alike.

The "sample" was a 14 tonne footbridge that is 20 metres long and 5 metres high and has been used to allow access from one side of the NPL site to the other for the last 46 years. With redevelopment of the NPL site this bridge has become redundant. Rather than demolish the bridge, and in the spirit of recycling, NPL researchers have used this unique opportunity to run a project using the old bridge to improve civil engineering structures.

Before this could begin the small matter of needing to move the massive bridge across the site away from the demolition zone needed to be addressed. Moving such a structure is unusual and was expertly carried out by Burton Smith and Beck and Pollitzer who used a 250 tonne capacity crane that extended nearly 50 metres into the sky.

After lifting the bridge it was then trailered across the NPL site, with essential co-operation from LGC, taking an hour to travel the quarter mile earlier this year, squeezing around tight turns and under trees before being lifted above existing buildings to its final resting place......... Posted by: Kevin      Read more         Source

April 1, 2008, 9:04 PM CT

Geologist decries floodplain development

Midwesterners have to be wondering: Will April be the cruelest month?.

Patterns in the Midwest this spring are eerily reminiscent of 1993 and 1994, back-to-back years of serious flooding. The great flood of 1993 caused nearly $20 billion of economic damage, damaging or destroying more than 50,000 homes and killing at least 38 people.

Parallels this year include abnormally high levels of precipitation in late winter and early spring, and early flooding in various regions. In March, Missouri, Arkansas and Illinois and the Ohio River experienced flooding. A still-unknown factor is the effect of the snow melt from upstream states on river systems this spring and summer. Wisconsin, for example, had record amounts of snow this winter.

Despite the similarity in conditions and periods of flooding nearly every year after those flood years more than a decade ago, one thing Midwesterners have not learned is "geologic reality," says Robert E. Criss, Ph.D., professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis.

"When people build commercial or residential real estate in flood plains, when they build on sink holes, when they build on fault lines, when they build on the hillsides in L.A. that are going to burn and burn, over and over again, they're ignoring geologic reality," Criss says. "They're asking for chronic problems."........ Posted by: Tyler      Read more         Source

April 1, 2008, 8:58 PM CT

Some Migratory Birds Can't Find Success In Urban Areas

New research finds fresh evidence that urbanization in the United States threatens the populations of some species of migratory birds.

But the six-year study also refutes one of the most widely accepted explanations of why urban areas are so hostile to some kinds of birds.

Most ecologists have assumed that common nest predators in urban areas - such as house cats and raccoons - were destroying eggs or killing young birds in greater numbers than in rural areas, said Amanda Rodewald, co-author of the study and associate professor of wildlife ecology at Ohio State University's School of Environment and Natural Resources.

But this study was one of the first to actually test that assumption by monitoring natural nests over several years. And the results showed that predators weren't the main problem: instead, the birds just didn't seem to like urban areas and gave up more easily.

Urban areas attracted lower-quality birds which, in comparison to those in rural areas, arrived later in the spring, left earlier in the fall, made fewer nesting attempts and were much less likely to return to nesting spots from year to year.

"There is something about these urban forests that strikes the birds as unsuitable," Rodewald said. "Even when they try nesting, they are less likely to renest after failure or to return in subsequent years"......... Posted by: Ashley      Read more         Source

April 1, 2008, 8:28 PM CT

Small is Big During NanoDays

April 2008 witnesses the launch of two efforts--with major funding from the National Science Foundation--that are intended to promote understanding of nanotechnology among the general public. Nanotechnology is the art and science of manipulating matter at the nanoscale (down to 1/100,000 the width of a human hair) to create new and unique materials and products. It is also the subject of "Nanotechnology: The Power of Small," a three-part, in-depth Fred Friendly Seminars series, airing on public television beginning this month; and NanoDays, a nationwide offering of educational programs about nanoscale science and engineering and its potential impacts.

"Nanotechnology: The Power of Small" brings together policymakers, scientists, journalists and community leaders to explore the promises and problems of this new technology. Guided by John Hockenberry, public radio news anchor and former NBC News correspondent, panelists wrestle with the benefits and risks of nanotechnology in three one-hour programs devoted to the issues of privacy, health and the environment. In "Watching You. Watching Me," panelists explore such questions as whether a tiny implantable sensor is a reasonable way to keep track of a grandparent who may be experiencing dementia. In "Forever Young," they discuss how nanomedicine could greatly expand life expectancy while creating a detailed record of individuals' health indicators. In "Clean, Green and Unseen," panelists look at the allure and the unknowns surrounding promising new consumer products and environmental applications......... Posted by: Kevin      Read more         Source

March 31, 2008, 8:12 PM CT

First 'active matrix' display using nanowires

Engineers have created the first "active matrix" display using a new class of transparent transistors and circuits, a step toward realizing applications such as e-paper, flexible color monitors and "heads-up" displays in car windshields.

The transistors are made of "nanowires," tiny cylindrical structures that are assembled on glass or thin films of flexible plastic. The scientists used nanowires as small as 20 nanometers - a thousand times thinner than a human hair - to create a display containing organic light emitting diodes, or OLEDS. The OLEDS are devices that rival the brightness of conventional pixels in flat-panel television sets, computer monitors and displays in consumer electronics.

"This is a step toward demonstrating the practical potential of nanowire transistors in displays and for other applications," said David Janes, a researcher at Purdue University's Birck Nanotechnology Center and a professor in the School of Electrical and Computer Engineering.

The nanowires were used to create a proof-of-concept active-matrix display similar to those in television sets and computer monitors. An active-matrix display is able to precisely direct the flow of electricity to produce video because each picture element, or pixel, possesses its own control circuitry......... Posted by: Kevin      Read more         Source