June 10, 2007, 7:35 PM CT

Oxygen trick could see organic costs tumble

A simple, cheap treatment using just oxygen could allow growers to store organic produce for longer and go a long way towards reducing the price of organic fruit and vegetables, reports Lisa Richards in Chemistry & Industry, the magazine of the SCI.

Currently UK shoppers have to pay twice as much for some organic products. Organic apples, for example, are around double the price of conventionally grown apples in Sainburys, Waitrose and Tesco.

One of the major contributing factors affecting the price is the short shelf life of organic produce. Conventional produce can be treated with inexpensive chemicals to aid preservation. But these cannot be used for organic produce, as by definition no artificial chemicals are used during processing.

With some organic fruit and veg, there can be large losses [during storage], Claudia Ruane, spokes person for Abel & Cole organic produce retailers told C&I. Ruane explained that although many organic farms do have reasonably sophisticated refrigeration units, there are very expensive and used only for brief storage before collection. These are important and costly but if paying out for these facilities can ensure a whole crop is not rejected by a retailer because it is a little limp or dehydrated, then it is a cost that has to be absorbed, she said......... Posted by: Jessica      Read more         Source

June 7, 2007, 7:27 PM CT

Turning the tables in chemistry

Waltham, MAWhat do glowing veggies have to do with a career in science" It just so happens that electrified pickles swimming in metal ions are one example of the type of undergraduate chemistry class demonstration that helps make a future in science a bright possibility, rather than a total turn-off, for a number of students.

In a commentary in this months Nature Chemical Biology, Brandeis University and Howard Hughes Medical Institute (HHMI) Professor Irving Epstein outlines a gathering storm clouding the future of U.S. science and prescribes a series of strategies to help avert a looming national crisis. Epstein says the continued success of U.S. science is seriously threatened by the fact that increasing numbers of undergraduates, especially the disadvantaged, are writing off a career in science.

Why? A number of students find introductory science, and chemistry in particular, both difficult and dull the way it is conventionally taught at the college level, discouraging a number of potential researchers before they ever have the chance to get hooked on science.

Anyone who teaches an introductory science course at one of this countrys elite universities is familiar with the sea of white faces he or she encounters, and the tendency of that ocean to whiten even more as the semester progresses and as one moves up the ladder of courses, writes Epstein, who last year won $1 million from HHMI to revamp introductory chemistry at Brandeis with an eye to luringand retainingmore students in science, especially disadvantaged ones......... Posted by: Sarah      Read more         Source

June 7, 2007, 7:25 PM CT

Who needs environmental monitoring?

We monitor the stock market, the weather, our blood pressure. Yet environmental monitoring is often criticized as being unscientific, expensive, and wasteful. Researchers argue that environmental monitoring is a crucial part of science in the review, Who needs environmental monitoring" Gary Lovett (Institute of Ecosystem Studies) and his colleagues from several universities and US government offices contributed to the review.

The review is especially relevant, given the budgetary constraints on current monitoring and the ongoing debate regarding the opportunities, limitations, and costs linked to the establishment of national environmental observatories in the US. These include the upcoming National Ecological Observatory Network, as well as established ecological monitoring programs such as those run by the Environmental Protection Agency and face imminent closure unless Congress reverses the Agencys budgetary Plans that monitor air pollution and acid rain.

Long-term monitoring programs help society understand environmental issues including acid rain deposition, clean air, ozone, global warming, and invasive species.

As per Lovett et al., the absence of monitoring can greatly hinder evaluation of the effectiveness of environmental policies and programs......... Posted by: Tyler      Read more         Source

June 6, 2007, 10:04 PM CT

Motion of a Single Electron on Video

To observe the motion of an electron - an elementary particle with a mass that is one billionth of a billionth of a billionth of a gram - has been considered to be impossible. So when two Brown University physicists showed movies of electrons moving through liquid helium at the 2006 International Symposium on Quantum Fluids and Solids in Kyoto, they raised some eyebrows.

The images, which were published online on April 28, 2007, in the Journal of Low Temperature Physics, show scattered points of light moving down the screen - some in straight lines, some following a snakelike path. The Matrix it's not. Still, the fact that they can be seen at all is astounding. "We were astonished when we first saw an electron moving across the screen," said Humphrey Maris, a professor of physics at Brown University. "Once we had the idea, setting it up was surprisingly easy".

Maris and Wei Guo, a doctoral student, took advantage of the bubbles that form around electrons in supercold liquid helium. Using sound waves to expand the bubbles and a coordinated strobe light to illuminate them, Guo was able to catch their movements on a home video camera.

A free electron repels the atoms that surround it, creating a small space, or bubble, around itself. In conventional liquids, the bubble shrinks to nothing because the surface tension of the liquid works against the repulsive force. Superfluid helium has very little surface tension, so the bubble can become much larger. The two opposing forces balance when the diameter of the bubble is about 40 angstroms - still far to tiny to see......... Posted by: Kevin      Read more         Source

June 6, 2007, 9:59 PM CT

Dirty snow may warm Arctic

The global warming debate has focused on carbon dioxide emissions, but researchers at UC Irvine have determined that a lesser-known mechanism - dirty snow - can explain one-third or more of the Arctic warming primarily attributed to greenhouse gases.

Snow becomes dirty when soot from tailpipes, smoke stacks and forest fires enters the atmosphere and falls to the ground. Soot-infused snow is darker than natural snow. Dark surfaces absorb sunlight and cause warming, while bright surfaces reflect heat back into space and cause cooling.

"When we inject dirty particles into the atmosphere and they fall onto snow, the net effect is we warm the polar latitudes," said Charlie Zender, associate professor of Earth system science at UCI and co-author of the study. "Dark soot can heat up quickly. It's like placing tiny toaster ovens into the snow pack".

The study appears this week in the Journal of Geophysical Research.

Dirty snow has had a significant impact on climate warming since the Industrial Revolution. In the past 200 years, the Earth has warmed about.8 degree Celsius. Zender, graduate student Mark Flanner, and their colleagues calculated that dirty snow caused the Earth's temperature to rise.1 to.15 degree, or up to 19 percent of the total warming......... Posted by: Tyler      Read more         Source

June 1, 2007, 9:34 PM CT

Long-distance record -- 'Quantum keys' sent 200 kilometers

Palo Alto, Calif. -- Particles of light serving as quantum keysthe latest in encryption technologyhave been sent over a record-setting 200-kilometer fiber-optic link by scientists from the National Institute of Standards and Technology (NIST), NTT Corp. in Japan, and Stanford University. The experiment, using mostly standard components and transmitting at telecommunications frequencies, offers an approach for making practical inter-city terrestrial quantum communications networks as well as long-range wireless systems using communication satellites.

The demonstration, described in Nature Photonics,* was conducted in a Stanford lab with optical fiber wrapped around a spool. In addition to setting a distance record for quantum key distribution (QKD), it also is the first gigabit-rate experimenttransmitting at 10 billion light pulses per secondto produce secure keys. The rate of processed key productionthe keys corrected for errors and enhanced for privacywas much lower due to the long distance involved, and the key was not used to encrypt a digital message as it would be in a complete QKD system. QKD systems transmit a stream of single photons with their electric fields in different orientations to represent 1s and 0s, which are used to make quantum keys to encrypt and decrypt messages. Properly executed, quantum encryption is unbreakable because eavesdropping changes the state of the photons......... Posted by: Kevin      Read more         Source

June 1, 2007, 9:31 PM CT

connecting climate change, origins of agriculture in Mexico

New charcoal and plant microfossil evidence from Mexicos Central Balsas valley links a pivotal cultural shift, crop domestication in the New World, to local and regional environmental history. Agriculture in the Balsas valley originated and diversified during the warm, wet, postglacial period following the much cooler and drier climate in the final phases of the last ice age. A significant dry period appears to have occurred at the same time as the major dry episode linked to the collapse of Mayan civilization, Smithsonian scientists and his colleagues report in the Proceedings of the National Academy of Sciences online.

Our climate and vegetation studies reveal the ecological settings in which people domesticated plants in southwestern Mexico. They also emphasize the long-term effects of agriculture on the environment, said Dolores Piperno, curator of archaeobotany and South American archaeology at the Smithsonians National Museum of Natural History and the Smithsonian Tropical Research Institute in Panama.

Pipernos co-authors include Enrique Moreno and Irene Holst, research assistants at STRI; Jose Iriarte, lecturer in archaeology at the University of Exeter in England; Matthew Lachinet, assistant professor at the University of Nevada in Las Vegas; John Jones, assistant professor at Washington State University; Anthony Ranere, professor at Temple University; and Ron Castanzo, research collaborator at the National Museum of Natural History......... Posted by: Tyler      Read more         Source

May 31, 2007, 11:58 PM CT

evidence tropical cyclones have climate-control role

Purdue University scientists have found evidence that tropical cyclones and hurricanes play an important role in the ocean circulation patterns that transport heat and maintain the climate of North America and Europe.

These findings support a 2001 theory by Kerry Emanuel, a professor of atmospheric science at Massachusetts Institute of Technology, and suggest that there is an additional factor to be included in climate models that may change predictions of future climate scenarios.

"It was thought that hurricanes occurred over too short of a time period and over too small of an area to affect the global system," said Matthew Huber, the Purdue University professor of earth and atmospheric sciences who led the research group. "This research provides evidence that hurricanes play an important role and may be one of the missing pieces in the climate modeling puzzle".

The research also showed that hurricanes cool the tropics, forming in response to higher temperatures and acting as a thermostat for the area, Huber said.

"Warm water fuels hurricanes, which have been shown to leave cold water in their wake," said Huber, who also is a member of the Purdue Climate Change Research Center at Discovery Park.

"I like to say the good news is that hurricanes function like a thermostat for the tropics, and the bad news is that hurricanes function like a thermostat for the tropics. The logical conclusion of this finding, taking into account past research into the impact of rising temperatures on cyclone and hurricane intensity, is that as the world and the tropics warm, there will be an increase in the integrated intensity of hurricanes."........ Posted by: Tyler      Read more         Source

May 30, 2007, 0:05 AM CT

Days Of Snow Melting On The Rise In Greenland

In 2006, Greenland experienced more days of melting snow and at higher altitudes than average over the past 18 years, as per a new NASA-funded project using satellite observations.

Daily satellite observations have shown snow melting on Greenlands ice sheet over an increased number of days. The resulting data help researchers understand better the speed of glacier flow, how much water will pour from the ice sheet into the surrounding ocean and how much of the suns radiation will reflect back into the atmosphere.

"We now have the ability to monitor melting snow on Greenlands ice sheet on a daily basis using sensors on satellites measuring the electromagnetic signal naturally emitted by the ice sheet," said Marco Tedesco, research scientist at the Joint Center for Earth Systems Technology cooperatively managed by NASAs Goddard Space Flight Center, Greenbelt, Md., and the University of Maryland at Baltimore County, Baltimore.

"The sensors detected that snowmelt occurred more than 10 days longer than the average over certain areas of Greenland in 2006," said Tedesco, who is lead author of the study, which appears in the May 29 issue of the American Geophysical Union's Eos.

Tedesco applied a new method for detecting melting snow to data from the Special Sensor Microwave Imaging radiometer (SSM/I) flying aboard the Defense Meteorological Satellite Program spacecraft. The sensor can see through clouds and does not require sunlight to make measurements, providing scientists with multiple daily observations. Tedesco has updated the results annually since 1988, which has enabled him to analyze trends in the duration of snowmelt and extent over specific areas of Greenland......... Posted by: Tyler      Read more         Source

May 25, 2007, 3:30 PM CT

Fiftieth Anniversary of First Digital Image

It was a grainy image of a baby-just 5 centimeters by 5 centimeters-but it turned out to be the well from which satellite imaging, Computerized axial tomography scans, bar codes on packaging, desktop publishing, digital photography and a host of other imaging technologies sprang.

It was 50 years ago this spring that National Bureau of Standards (NBS, now known as the National Institute of Standards and Technology, or NIST) computer pioneer Russell Kirsch asked "What would happen if computers could look at pictures?" and helped start a revolution in information technology. Kirsch and colleagues at NBS, who had developed the nation's first programmable computer, the Standards Eastern Automatic Computer (SEAC), created a rotating drum scanner and programming that allowed images to be fed into it. The first image scanned was a head-and-shoulders shot of Kirsch's three-month-old son Walden.

The ghostlike black-and-white photo only measured 176 pixels on a side-a far cry from today's megapixel digital snapshots-but it would become the Adam and Eve for all computer imaging to follow. In 2003, the editors of Life magazine honored Kirsch's image by naming it one of "the 100 photographs that changed the world".

Kirsch and his wife Joan, an art historian, now reside in Oregon. Together, they use computers to analyze paintings and define the artistic processes by which they were created. Son Walden-whose face helped launch the era of computerized photography-works in communications for Intel following a successful career as a television news reporter......... Posted by: Kevin      Read more         Source