Science blog

February 3, 2010, 8:19 AM CT

magnetism's role in superconductors

Neutron scattering experiments performed at the Department of Energy's Oak Ridge National Laboratory give good evidence that, if superconductivity is correlation to a material's magnetic properties, the same mechanisms are behind both copper-based high-temperature superconductors and the newly discovered iron-based superconductors.

The work, published in a recent Nature Physics, waccording toformed at ORNL's Spallation Neutron Source (SNS) and High Flux Isotope Reactor (HFIR) along with the ISIS Facility at the United Kingdom's Rutherford Appleton Laboratory.

High-temperature superconducting materials, in which a material conducts electricity without resistance at a relatively high temperature, have potential for application to energy efficient technologies where little electricity is lost in transmission.

The research community was stirred in 2008 when a Japanese team reported high-temperature superconductivity in an iron-based material. Previously, only copper-based, or cuprate, materials were known to have those properties. The discovery elicited widespread and intense analysis of the material's structure and properties.

"The pairing up of electrons is essential for the formation of the macroscopic quantum state giving rise to superconductivity," said lead researcher Mark Lumsden of ORNL. "One of the leading proposals for the pairing mechanism in the iron-based superconductors is that magnetic interactions, provide the glue that binds the electrons together."........ Posted by: Beverly      Read more         Source

January 25, 2010, 8:09 AM CT

Driving hinders talking

It is well known that having a conversation (for example on a cell phone) impairs one's driving. A newly released study indicates the reverse is also true: Driving reduces one's ability to comprehend and use language.

The findings, from scientists at the University of Illinois, appear in the journal Psychonomic Bulletin & Review

This is the first study to find that driving impairs language skills, said Gary Dell, a psycholinguist in the department of psychology at Illinois and corresponding author on the study. Two prior studies had reported that driving did not impair the accuracy and comprehension of speech.

"The prior findings made no sense to those of us who have studied language," Dell said. "You might believe that talking is an easy thing to do and that comprehending language is easy. But it's not. Speech production and speech comprehension are attention-demanding activities, and so they ought to compete with other tasks that require your attention like driving".

The newly released study was conducted in a driving simulator at the Beckman Institute for Advanced Science and Technology at Illinois. The participants worked in pairs one as a driver and the other as a conversation partner who was either in the simulator with the driver or talking with the driver via a hands-free cell phone from a remote location. Half of the 96 participants were adults over the age of 65 and half were in their late teens and early 20s......... Posted by: Beverly      Read more         Source

Mon, 25 Jan 2010 05:22:30 GMT

Your Desk Will Never Be Boring Again

Just when you think you've seen it all, a company called Pandigital has developed a digital picture frame that is always email connected. Photos are sent via ATT wireless network without the need of WiFi directly to the 8-inch LED frame. Since the unit has a dedicated e-mail address, anyone with the address can e-mail photos to the frame.

The device will come equipped with a capacity of 300 e-mailed photos and after that, additional photos can be purchased for $9.99 per 100 e-mailed photos, $29.99 for 400 and $49.99 for 700.

Spec wise the 8-inch backlit LED display boasts 800-by-600 resolution, 1GB of internal memory and a 6-in-1 built-in media card reader for uploading photos without using the email feature.
The Photo Mail LED Digital Photo Frame is set to be released soon for a retail price of $149. For more details, click here. Posted by: Jeff      Read more     Source

January 22, 2010, 8:08 AM CT

Where to run for a fly ball?

While baseball fans still rank "The Catch" by Willie Mays in the 1954 World Series as one of the greatest baseball moments of all times, researchers see the feat as more of a puzzle: How does an outfielder get to the right place at the right time to catch a fly ball? .

Thousands of fans (and hundreds of thousands of YouTube viewers) saw Mays turn his back on a fly ball, race to the center field fence and catch the ball over his shoulder, seemingly a precise prediction of a fly ball's path that led his team to victory. As per a recent article in the Journal of Vision ("Catching Flyballs in Virtual Reality: A Critical Test of the Outfielder Problem"), the "outfielder problem" represents the definitive question of visual-motor control. How does the brain use visual information to guide action?

To test three theories that might explain an outfielder's ability to catch a fly ball, researcher Philip Fink, PhD, from Massey University in New Zealand and Patrick Foo, PhD, from the University of North Carolina at Ashville programmed Brown University's virtual reality lab, the VENLab, to produce realistic balls and simulate catches. The team then lobbed virtual fly balls to a dozen experienced ball players.

"The three existing theories all predict the same thing: successful catches with very similar behavior," said Brown researcher William Warren, PhD. "We realized that we could pull them apart by using virtual reality to create physically impossible fly ball trajectories"......... Posted by: Beverly      Read more         Source

Mon, 18 Jan 2010 01:47:38 GMT

You and Your Research

Richard Hamming is not a household name. As a long-time Bell Labs scientist, Hamming made lasting impacts on mathematics, computer science, and engineering. He also gave one of the best talks I have come across for anyone pursuing/interested in pursuing a career in science. This talk, titled "You and Your Research" was presented to the Bell Communications Research Colloquium Seminar on 7 March 1986. It could be titled "How to do Great Research".

Hamming first discusses his motivation:
At Los Alamos I was brought in to run the computing machines which other people had got going, so those scientists and physicists could get back to business. I saw I was a stooge. I saw that although physically I was the same, they were different. And to put the thing bluntly, I was envious. I wanted to know why they were so different from me. I saw Feynman up close. I saw Fermi and Teller. I saw Oppenheimer. I saw Hans Bethe: he was my boss. I saw quite a few very capable people. I became very interested in the difference between those who do and those who might have done. Hamming found that the major difference between good and great is largely one of attiHe summarizes his findings:
In summary, I claim that some of the reasons why so many people who have greatness within their grasp don"t succeed are: they don"t work on important problems, they don"t become emotionally involved, they don"t try and change what is difficult to some other situation which is easily done but is still important, and they keep giving themselves alibis why they don"t. In other words, ask yourself three questions:

1. What are the most important problems in your field?

2. Are you working on one of them?

3. Why not? Posted by: Dennehy      Read more     Source

Sun, 17 Jan 2010 15:48:00 GMT

Special Medical Exhibit

I came across quite a special medical exhibit on BoingBoing featuring fascinating images and ancient medical gadgets:

There’s a fascinating exhibit at the Mori Art Museum in Tokyo right now called Medicine and Art: Imagining a Future for Life and Love. It showcases 150 works of art that represent our fascination with the human body, both as a living machine that we’re constantly trying to understand and as an artistic medium. The iconic example of this is Leonardo Da Vinci’s cranium drawings from the 15th century (pictured right), part of the Royal Collection belonging to Queen Elizabeth II.

Gilles Barbier; L’Hospice / The Nursing Home; 2002; six wax figures, television, various elements dimension variable; Courtesy: Galerie G.-P. & N. Vallois, Paris

Image source: BoingBoing Posted by: Bertalan      Read more     Source

January 11, 2010, 7:45 AM CT

Quantum-mechanically Entangled

For the first time, physicists have convincingly demonstrated that physically separated particles in solid-state devices can be quantum-mechanically entangled. The achievement is analogous to the quantum entanglement of light, except that it involves particles in circuitry instead of photons in optical systems. Both optical and solid-state entanglement offer potential routes to quantum computing and secure communications, but solid-state versions may ultimately be easier to incorporate into electronic devices. The experiment is reported in an upcoming issue of Physical Review Letters and highlighted with a Viewpoint in the January 11 issue of Physics (http://physics.aps.org.).

In optical entanglement experiments, a pair of entangled photons appears to be separated via a beam splitter. Despite their physical separation, the entangled photons continue to act as a single quantum object. A team of physicists from France, Gera number of and Spain has now performed a solid-state entanglement experiment that uses electrons in a superconductor in place of photons in an optical system.

As conventional superconducting materials are cooled, the electrons they conduct entangle to form what are known as Cooper pairs. In the new experiment, Cooper pairs flow through a superconducting bridge until they reach a carbon nanotube that acts as the electronic equivalent of a beam splitter. Occasionally, the electrons part ways and are directed to separate quantum dots -- but remain entangled. Eventhough the quantum dots are only a micron or so apart, the distance is large enough to demonstrate entanglement comparable to that seen in optical systems......... Posted by: Beverly      Read more         Source

January 4, 2010, 8:09 AM CT

Modern techniques to study ancient modern humans

DNA that is left in the remains of long-dead plants, animals, or humans allows a direct look into the history of evolution. So far, studies of this kind on ancestral members of our own species have been hampered by scientists' inability to distinguish the ancient DNA from modern-day human DNA contamination. Now, research by Svante Pbo from The Max-Planck Institute for Evolutionary Anthropology in Leipzig, published online on December 31st in Current Biology a Cell Press publication overcomes this hurdle and shows how it is possible to directly analyze DNA from a member of our own species who lived around 30,000 years ago.

DNA the hereditary material contained in the nuclei and mitochondria of all body cells is a hardy molecule and can persist, conditions permitting, for several tens of thousands of years. Such ancient DNA provides researchers with unique possibilities to directly glimpse into the genetic make-up of organisms that have long since vanished from the Earth. Using ancient DNA extracted from bones, the biology of extinct animals, such as mammoths, as well as of ancient humans, such as the Neanderthals, has been successfully studied in recent years.

The ancient DNA approach could not be easily applied to ancient members of our own species. This is because the ancient DNA fragments are multiplied with special molecular probes that target certain DNA sequences. These probes, however, cannot distinguish whether the DNA they recognize comes from the ancient human sample or was introduced much later, for instance by the archaeologists who handled the bones. Thus, conclusions about the genetic make-up of ancient humans of our own species were fraught with uncertainty......... Posted by: Beverly      Read more         Source

December 21, 2009, 8:11 AM CT

Global warming likely to be amplified

Scientists studying a period of high carbon dioxide levels and warm climate several million years ago have concluded that slow changes such as melting ice sheets amplified the initial warming caused by greenhouse gases.

The study, reported in the journal Nature Geoscience, observed that a relatively small rise in atmospheric carbon dioxide levels was linked to substantial global warming about 4.5 million years ago during the early Pliocene.

Coauthor Christina Ravelo, professor of ocean sciences at the University of California, Santa Cruz, said the study indicates that the sensitivity of Earth's temperature to increases in carbon dioxide in the atmosphere is greater than has been expected on the basis of climate models that only include rapid responses.

Carbon dioxide and other greenhouse gases trap heat in the atmosphere, leading to increased atmospheric and sea-surface temperatures. Relatively rapid feedbacks include changes in atmospheric water vapor, clouds, and sea ice. These short-term changes probably set in motion long-term changes in other factors--such as the extent of continental ice sheets, vegetation cover on land, and deep ocean circulation--that lead to additional global warming, Ravelo said.

"The implication is that these slow components of the Earth system, once they have time to change and equilibrate, may amplify the effects of small changes in the greenhouse gas composition of the atmosphere," she said......... Posted by: Beverly      Read more         Source

December 18, 2009, 6:56 PM CT

Bioactive glass nanofibers produced

A team of scientists from the University of Vigo, Rutgers University in the United States and Imperial College London, in the United Kingdom, has developed "laser spinning", a novel method of producing glass nanofibres with materials. They have been able to manufacture bioglass nanofibres, the bioactive glass used in regenerating bone, for the first time.

"Laser spinning makes it possible to produce glass nanofibres of compositions that would be impossible to obtain using other methods", Flix Quintero, co-author of the study and a researcher at the University of Vigo, tells SINC.

The new technique, which was highlighted on the front cover of the journal Advanced Functional Material, involves using a high-energy laser that melts a small amount of precursor material. This creates a super-fine filament that is lengthened and cooled by a powerful gas current.

The scientist highlights the simplicity of the system, that "can be used in environmental conditions", as well as its high rate of production and its ability to easily control the composition of the material.

This international team has managed to produce bioglass composition nanofibres, a bioactive glass that is used to regenerate bony tissue. The laser spinning makes the material flexible, continuous and gives it a nanometric structure, which helps in the proliferation and spread of bone cells......... Posted by: Beverly      Read more         Source

Wed, 09 Dec 2009 14:05:03 GMT

The Spanish Wines of Toro

© Rivard


Mercury News had a feature recently on the growing popularity of wines from Spain"s historic Toro region. Vines have been planted in Toro, about 100 miles northwest of Madrid, for hundreds of years and winemaking has been documented since the 1st century B.C. But the region was recognized as a Denominacion de Origen only in 1987. The primary grape is a local version of tempranillo known as tinta de Toro, and many small, impossibly gnarled bush vines are quite old - some 100 years or more.While some of Toro"s wines are now becoming pricey, you can still get excellent Toro wines for as little as $20 a bottle. It"s an interesting feature. Posted by: Doreen      Read more     Source

November 13, 2009, 8:21 AM CT

Record High Temperatures Far Outpace Record Lows

Spurred by a warming climate, daily record high temperatures occurred twice as often as record lows over the last decade across the continental United States, new research shows. The ratio of record highs to lows is likely to increase dramatically in coming decades if emissions of greenhouse gases continue to climb.

"Climate change is making itself felt in terms of day-to-day weather in the United States," says Gerald Meehl, the main author and a senior scientist at the National Center for Atmospheric Research (NCAR). "The ways these records are being broken show how our climate is already shifting".

The study, by authors at NCAR, Climate Central, The Weather Channel, and the National Oceanic and Atmospheric Administration (NOAA), has been accepted for publication in Geophysical Research Letters. It was funded by the National Science Foundation, NCAR's sponsor, the Department of Energy, and Climate Central.

If temperatures were not warming, the number of record daily highs and lows being set each year would be approximately even. Instead, for the period from January 1, 2000, to September 30, 2009, the continental United States set 291,237 record highs and 142,420 record lows, as the country experienced uncommonly mild winter weather and intense summer heat waves......... Posted by: Beverly      Read more         Source

November 11, 2009, 8:10 AM CT

Smaller transistors and more powerful chips

Purdue University scientists progress in developing a new type of transistor that uses a finlike structure instead of the conventional flat design, possibly enabling engineers to create faster and more compact circuits and computer chips.

The fins are made not of silicon, like conventional transistors, but from a material called indium-gallium-arsenide. Called finFETs, for fin field-effect-transistors, scientists from around the world have been working to perfect the devices as potential replacements for conventional transistors.

In work led by Peide Ye, an associate professor of electrical and computer engineering, the Purdue scientists are the first to create finFETs using a technology called atomic layer deposition. Because atomic layer deposition is usually used in industry, the new finFET technique may represent a practical solution to the coming limits of conventional silicon transistors.

"We have just demonstrated the proof of concept here," Ye said.

Findings are detailed in three research papers being presented during the International Electron Devices Meeting on Dec. 7-9 in Baltimore. The work is led by doctoral student Yanqing Wu, who provided major contributions for two of the papers.

The finFETs might enable engineers to sidestep a problem threatening to derail the electronics industry. New technologies will be needed for industry to keep pace with Moore's law, an unofficial rule stating that the number of transistors on a computer chip doubles about every 18 months, resulting in rapid progress in computers and telecommunications. Doubling the number of devices that can fit on a computer chip translates into a similar increase in performance. However, it is becoming increasingly difficult to continue shrinking electronic devices made of conventional silicon-based semiconductors......... Posted by: Beverly      Read more         Source

October 7, 2009, 7:15 AM CT

How dinosaurs coped with slippery slopes

A new investigation of a fossilized tracksite in southern Africa shows how early dinosaurs made on-the-fly adjustments to their movements to cope with slippery and sloping terrain. Differences in how early dinosaurs made these adjustments provide insight into the later evolution of the group.

This research, which was conducted by scientists at the University of Michigan, Argentina's Universidad de Buenos Aires, and the Iziko South African Museum in Cape Town, South Africa, will be published online Oct. 6 in the open-access journal PLoS ONE

The Moyeni tracksite in Lesotho contains more than 250 footprints made by a variety of four-legged animals near the beginning of the Jurassic Period (about 200 million years ago), when the Earth's landmasses were united as Pangea. The site was first discovered and described in the 1960s and 1970s by French paleontologist Paul Ellenberger but has not since been examined in detail. In their re-analysis of the fossil tracksite, the scientists created a high-resolution map of trackway surface using a combination of traditional mapping techniques and a 3D surface scanner, which recorded millimeter-scale detail. The digital record of the site will serve as an archive and will be the source of future research, said U-M's Jeffrey Wilson, an assistant professor in the Department of Geological Sciences and an assistant curator in the Museum of Paleontology......... Posted by: Beverly      Read more         Source

September 29, 2009, 10:29 PM CT

North Meets South?

Results of a newly released study add evidence that climate swings in the northern hemisphere over the past 12,000 years have been tightly associated with changes in the tropics.

The findings, published this week in the journal Science, suggest that a prolonged cold spell that caused glaciers in Europe and North America to creep forward several hundred years ago may have affected climate patterns as far south as Peru, causing tropical glaciers there to expand, too.

Glaciers in both the tropics and North Atlantic region reached their most recent maximum extents during the so-called Little Ice Age, about 1650 AD to 1850 AD, as per the researchers conducting the research.

To make the discovery, they employed a cutting-edge technique for dating glacial deposits.

"The results bring us one step closer to understanding global-scale patterns of glacier activity and climate during the Little Ice Age," says main author Joe Licciardi, a glacial geologist at the University of New Hampshire.

By understanding how glaciers behaved in the past, the georesearchers hope to predict how parts of the world will react as the planet warms.

Human civilization arose during fairly stable temperatures since the end of the last ice age, about 12,000 years ago. But research shows that even during this time glaciers fluctuated in large and sometimes surprising ways......... Posted by: Beverly      Read more         Source

September 23, 2009, 7:11 AM CT

Single molecules in microdroplets

Inventing a useful new tool for creating chemical reactions between single molecules, researchers at the National Institute of Standards and Technology (NIST) have employed microfluidicsthe manipulation of fluids at the microscopic scaleto make microdroplets that contain single molecules of interest. By combining this new microfluidic "droplet-on-demand" method with "optical tweezers" that could merge multiple droplets and cause their molecular contents to react, the research may ultimately lead to a compact, integrated setup for obtaining single-molecule information on the structure and function of important organic materials, such as proteins, enzymes, and DNA.

With the aid of NIST's Center for Nanoscale Science and Technology, physicists Carlos Lpez-Mariscal and Kristian Helmerson created a tiny microfluidic device with a channel through which water can flow. Squeezed into a narrow stream by a mixture of oils whose viscosity, or resistance to flow, exerts pressure on it, the water then enters a narrow constriction. The water's abrupt pressure dropaccompanied by a dash of detergentbreaks its surface tension, splitting it into small droplets. (This same effect occurs when a thin stream of water falling from a faucet breaks up into small drops.).

The droplet sizes are highly uniform and can be tuned by adjusting the width of the constriction. With this technique, the scientists made droplets about a micrometer in diameteror half an attoliter (half a billionth of a billionth of a liter) in volume......... Posted by: Beverly      Read more         Source

Wed, 16 Sep 2009 03:56:06 GMT

LG releases XD3 minimalist, portable HDDs

It seems LG has sent out its portable HDDs for a facelift and ended up with a luscious makeover - the XD3 slim, portable HDDs announced for the Korean market.

And the results are appreciable in a single glance - a high-quality, brushed aluminum casing that comes in four colors (red, gold, black and silver) and with rubber padding for shock absorption, plus an enviable 13mm thickness. While it comes to specs under the hood however, there aren"t many to make you blush - as with earlier storage drives from LG (XD1 and XD2), the XD3 is available in capacities of 320GB and 500GB, with the same USB and SATA II connectivity. It retails in Korea at a price of 110,000 Won (US $90).

Via Engadget. Posted by: Sarah      Read more     Source

September 15, 2009, 2:39 PM CT

An uncertain future for forests

The composition of some of our nation's forests may be quite different 200 to 400 years from today according to a recent study at the University of Illinois. The study found that temperature and photosynthetic active radiation were the two most important variables in predicting what forest landscapes may look like in the future. The uncertainties became very high after the year 2200.

Approximately 100,000 acres of forested area west of Lake Superior which make up the Boundary Waters Canoe Area was used for the study. Using computer models PnET-II and LANDIS-II, the researchers were able to simulate 209 possible scenarios, including 13 tree species and 27 possible climate profiles to predict how the landscape will look over time.

"The tools that we developed and we're using for the research project can be applied to any discipline dealing with risk and uncertainty in decision making," said U of I researcher George Gertner.

"We were dealing with the uncertainties in global change predictions using the projections established by the United Nations Intergovernmental Panel of Climate Change. These projections were based on different CO 2 reduction scenarios and global circulation models. ".

The study found that the most important source of uncertainty in the forest composition prediction is from the uncertainty in temperature predictions. The second most important source is photosynthetic active radiation, the third is carbon dioxide, and the fourth is precipitation......... Posted by: Beverly      Read more         Source

September 11, 2009, 7:35 AM CT

Carbon nanotubes could make efficient solar cells

Using a carbon nanotube instead of traditional silicon, Cornell scientists have created the basic elements of a solar cell that hopefully will lead to much more efficient ways of converting light to electricity than now used in calculators and on rooftops.

The scientists fabricated, tested and measured a simple solar cell called a photodiode, formed from an individual carbon nanotube. Reported online Sept. 11 in the journal Science, the scientists -- led by Paul McEuen, the Goldwin Smith Professor of Physics, and Jiwoong Park, assistant professor of chemistry and chemical biology -- describe how their device converts light to electricity in an extremely efficient process that multiplies the amount of electrical current that flows. This process could prove important for next-generation high efficiency solar cells, the scientists say.

"We are not only looking at a new material, but we actually put it into an application -- a true solar cell device," said first author Nathan Gabor, a graduate student in McEuen's lab.

The scientists used a single-walled carbon nanotube, which is essentially a rolled-up sheet of graphene, to create their solar cell. About the size of a DNA molecule, the nanotube was wired between two electrical contacts and close to two electrical gates, one negatively and one positively charged. Their work was inspired in part by prior research in which researchers created a diode, which is a simple transistor that allows current to flow in only one direction, using a single-walled nanotube. The Cornell team wanted to see what would happen if they built something similar, but this time shined light on it......... Posted by: Beverly      Read more         Source

August 26, 2009, 11:01 PM CT

Hankering for molecular electronics?

The sandwich recipe recently concocted by researchers working at the National Institute of Standards and Technology (NIST) may prove tasty for computer chip designers, who have long had an appetite for molecule-sized electronic components but no clear way to satisfy it until now.

The research team, which includes collaborators from the University of Maryland, has found a simple method of sandwiching organic molecules between silicon and metal, two materials fundamental to electronic components. By doing so, the team may have overcome one of the principal obstacles in creating switches made from individual molecules, which represent perhaps the ultimate in miniaturization for the electronics industry.

The idea of using molecules as switches has been around for years, carrying the promise of components that can be produced cheaply in huge numbers, perform faster as a group than their larger silicon brethren, and use only a tiny fraction of their energy. But eventhough there has been progress in creating the switching molecules themselves, the overall concept has been stuck on drawing boards in large part because organic molecules are delicate and tend to be damaged irreparably when subjected to one especially stressful step in the chip-building process: attaching them to electrical contacts......... Posted by: Beverly      Read more         Source

August 20, 2009, 6:42 AM CT

Increased climate volatility expected to worsen poverty

A newly released study supported by the World Bank has for the first time tried to combine, understand and predict the effects of climate change on food prices and wages in developing countries to assess how badly different socio-economic strata in sixteen vulnerable countries will be hit by extreme weather conditions, linked to climate change such as annual-scale hot, dry and wet extremes.

Using the same methodology for climate prediction as the International Panel on Climate Change and data from the Food and Agriculture Organization of the United Nations, the report, published in IOP Publishing's Environmental Research Letters today, Thursday, 20 August, is a crucial stepping stone in the fight to help those most at risk. Find the report http://stacks.iop.org/ERL/4/034004 from Thursday.

The paper, 'Climate volatility deepens poverty vulnerability in developing countries', written by scientists from the Development Research Group at the World Bank and climate scientists at Purdue University in Indiana, US, explains why extreme exposure to food price increases for the urban poor in countries such as Bangladesh, Mexico, Mozambique, Malawi, Tanzania and Zambia, suggest that it is the urban poor who will be hardest hit and enter most rapidly in to poverty as the climate changes throughout this century......... Posted by: Beverly      Read more         Source