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Tue, 21 Aug 2007 03:22:57 GMT

Clematis 'Candida'

Clematis 'Candida'
Botany Photo of the Day will have brief written entries on weekends, holidays and my vacations from April through September. – Daniel

Thank you to shotaku@Flickr from Missouri, USA for contributing today's photograph (original via BPotD Flickr Group Pool). Much appreciated!

One will often find this cultivar under the (incorrect) names Clematis 'Lanuginosa Candida' or Clematis lanuginosa 'Candida'. The Royal Horticultural Society points out, however, that Clematis 'Candida' should be used. The genes of Clematis lanuginosa are indeed found within this cultivar, but that species is one of two parents of this hybrid (the other being Clematis patens).

Posted by: Daniel Mosquin      Read more     Source

August 7, 2007, 10:38 PM CT

Link Between Sunspots, Rain And Disease in East Africa

Link Between Sunspots, Rain And Disease in East Africa
A new study shows that sunspot cycles can be used to predict heavy rains, flooding and subsequent disease outbreaks in East Africa.

This research, which was conducted by paleoclimatologist Curt Stager of Paul Smith's College in Paul Smiths, N.Y. and his colleagues, can be used by public health officials to increase measures against insect-borne diseases long before epidemics begin. The results are published online in the August 7 issue of the Journal of Geophysical Research.

The researchers showed that uncommonly heavy rainfalls in East Africa over the past century preceded peak sunspot activity by about one year.

"The hope is that people on the ground will use this research to predict heavy rainfall events," Stager said. "Those events lead to erosion, flooding and disease. With the help of these findings, we can now say when particularly rainy seasons are likely to occur, several years in advance".

"These results are an important step in applying paleoclimate analyses to predicting future environmental conditions and their impacts on society," said Dave Verardo, director of the National Science Foundation's paleoclimate program, which funded the research. "It's particularly important in a region [East Africa] perennially on the knife-edge of sustainability".........

Posted by: Nora      Read more         Source

August 3, 2007, 9:54 PM CT

Satellite Data Can Warn Of Famine

Satellite Data Can Warn Of Famine
A NASA researcher has developed a new method to anticipate food shortages brought on by drought. Molly Brown of NASAs Goddard Space Flight Center in Greenbelt, Md., and her colleagues created a model using data from satellite remote sensing of crop growth and food prices.

Brown conceived the idea while working with organizations in Niger, West Africa, that provide information regarding failed crops and help address local farmers' worries about feeding their families. Brown's new approach could improve the ability for government and humanitarian aid officials to plan and respond to drought-induced food price increases in Niger and elsewhere.

Supply and demand largely dictate food prices, with greater supply leading to lower prices and less supply leading to higher prices. During a food crisis in semi-arid regions like Niger, food shortages are often brought on when lack of rainfall significantly reduces the amount of grain farmers are able to grow. Farmers in regions like Niger are able only to grow a few drought-resistant crops, and therefore must buy grain at unaffordably high prices at the end of the year to make up for shortfalls in production. This scenario could drive a drought-driven food security crisis. A lack of locally-produced and affordable grain, coupled with increased prices and reduced access to food, could lead to starvation and hunger-related illness in the most vulnerable segments of society.........

Posted by: Edwin      Read more         Source

July 30, 2007, 9:43 PM CT

First ALMA Transporter Ready to Go

First ALMA Transporter Ready to Go
Transporting an ALMA Antenna (Artist's Impression)

The first of two spectacular vehicles for the ALMA (Atacama Large Millimeter/submillimeter Array) Observatory rolled out of its hangar and passed successfully a series of tests. This vehicle, the ALMA antenna transporter, is a rather exceptional 'lorry' driving on 28 tyres. It is 10m wide, 20m long and 6m high, weighs 130 tons and has as much power as two Formula 1 engines. This colossus will be able to transport a 115-ton antenna and set it down on a concrete pad within millimetres of a prescribed position.

The ALMA Project is a giant, international observatory currently in construction on the high-altitude Chajnantor site in Chile, and composed initially of 66 high-precision telescopes, operating at wavelengths of 0.3 to 9.6 mm. The ALMA antennas will be electronically combined and provide astronomical observations which are equivalent to a single large telescope of tremendous size and resolution. ALMA will be able to probe the Universe at millimetre and submillimetre wavelengths with unprecedented sensitivity and resolution, with an accuracy up to ten times better than the Hubble Space Telescope, and complementing images made with ESO's Very Large Telescope Interferometer.

The telescopes can be moved across the high-altitude desert Chajnantor plateau, covering antenna configurations as compact as 150 metres to as wide as 15 kilometres. Changing the relative positions of the antennas and thus also the configuration of the array allows for different observing modes, comparable to using a zoom lens on a camera.........

Posted by: Edwin      Read more         Source

July 30, 2007, 8:09 PM CT

Wider buffers are better

Wider buffers are better
Excess nitrogen caused by fertilizers, animal waste, leaf litter, sewer lines, and highways is responsible for contaminating groundwater. It can also cause human health risks when found in drinking water and oxygen depleted water bodies endangering animals that drink from them. Establishing Riparian buffers is considered a best management practice (BMP) by State and Federal resource agencies for maintaining water quality, and they may be especially critical in controlling amounts of human produced nitrogen.

Scientists at the U.S. Environmental Protection Agency collected data on the buffers along with nitrogen concentration in streams and groundwater to identify trends between nitrogen removal and buffer width, water flow path and vegetation. They found wide buffers (>50 meters) removed more nitrogen than narrow buffers (0-25 meters). Buffers of different vegetation types were equally effective but herbaceous and forest vegetation were more effective when wider. Removal of nitrogen within the water was efficient, but not related with buffer width; however removal on the water surface was related to buffer width. Nitrate nitrogen (sometimes used in fertilizer) did not differ by width, flow path or vegetation type. Results from the study are published in the July-August 2007 issue of the Journal of Environmental Quality.........

Posted by: Nora      Read more         Source

July 30, 2007, 7:33 PM CT

Think Pink To Produce "Green" Solar Energy

Think Pink To Produce
Yiying Wu
When it comes to producing earth-friendly solar energy, pink may be the new green, as per Ohio State University researchers.

Researchers here have developed new dye-sensitized solar cells (DSSCs) that get their pink color from a mixture of red dye and white metal oxide powder in materials that capture light.

Currently, the best of these new pink materials convert light to electricity with only half the efficiency of commercially-available silicon-based solar cells -- but they do so at only one quarter of the cost, said Yiying Wu, assistant professor of chemistry at Ohio State.

And Wu is hoping for even better.

"We think that one day, DSSC efficiency can reach levels comparable to any solar cell," he said. "The major advantage of DSSCs is that the cost is low. That is why DSSCs are so interesting to us, and so important".

Pink is a typical color for DSSCs. Most use dyes containing ruthenium, which has a red color; the metal oxide powder that turns the mix pink is most often titanium oxide or zinc oxide, which are both whitish in color. But Wu's materials are novel in that he's using more complex metals and exploring different particle shapes to boost the amount of electricity produced.

In a recent issue of the Journal of the American Chemical Society (JACS), he and his team report that they have made a new DSSC material using zinc stannate.........

Posted by: John      Read more         Source

July 23, 2007, 7:03 PM CT

Unexpected Strength To Nanothin Sheet Of Material

Unexpected Strength To Nanothin Sheet Of Material
Amazingly Strong Sheet of Nanoparticles
Tightly packed molecules lend unexpected strength to nanothin sheet of material.

Scientists at the University of Chicago and Argonne National Laboratory have discovered the surprising strength of a sheet of nanoparticles that measures just 50 atoms in thickness.

Its an amazing little marvel, said Heinrich Jaeger, Professor in Physics at the University of Chicago. This is not a very fragile layer, but rather a robust, resilient membrane.

Even when suspended over a tiny hole and poked with an ultrafine tip, the membrane boasts the equivalent strength of an ultrathin sheet of plexiglass that maintains its structural integrity at relatively high temperatures.

When we first realized that they can be suspended freely in air, it truly surprised all of us, said Xiao-Min Lin, a physicist at Argonnes Center for Nanoscale Materials.

The characteristics of the nanoparticles are described in the July 22 issue of the journal Nature Materials in a paper written by Jaeger and Lin, along with Klara Mueggenburg, a graduate student in physics at the University of Chicago, and Rodney Goldsmith, an undergraduate student at Xavier University in New Orleans who participated as part of the National Science Foundations Research Experience for Undergraduates program. The work was funded by the NSF-supported Materials Science and Engineering Center at the University of Chicago. Additional support came from the U.S. Department of Energy.........

Posted by: John      Read more         Source

July 23, 2007, 5:05 PM CT

Laser sets records in power and energy efficiency

Laser sets records in power and energy efficiency
The rise in global terrorism in recent years has brought significant attention to the needs for more advanced sensors and defense technologies to protect civilians and soldiers.

Next-generation laser-based defense systems are now being designed for this need, including the use of infrared countermeasures to protect aircraft from heat-seeking missiles and highly sensitive chemical detectors for reliable early detection of trace explosives and other toxins at a safe distance for personnel.

Since practical systems must be easily portable by a soldier, aircraft or unmanned vehicle, they must be lightweight, compact and power efficient. In addition, such systems also would need to be widely deployable and available to all soldiers, airplanes and public facilities, which requires a low production and operating cost. While several types of lasers exist today that can emit at the desired infrared wavelengths, none of these lasers meet the above requirements because they are either too expensive, not mass-producible, too fragile or require power-hungry and inefficient cryogenic refrigeration.

A new type of semiconductor-based laser, called the Quantum Cascade Laser (QCL), may soon change this situation. Like their computer chip cousins, semiconductors lasers are inherently compact and suitable for mass production, which has led to their widespread and low-cost use in everyday products, including CD and DVD players.........

Posted by: John      Read more         Source

July 19, 2007, 9:52 PM CT

Proteins' Dark Energy

Proteins' Dark Energy
Artist rendering of calmodulin molecule depicting protein "dark energy."
Image Credit: Mary Leonard and Michael Marlow, PhD, University of Pennsylvania School of Medicine
Scientists at the University of Pennsylvania School of Medicine are the first to observe and measure the internal motion inside proteins, or its "dark energy." This research, appearing in the current issue of Nature, has revealed how the internal motion of proteins affects their function and overturns the standard view of protein structure-function relationships, suggesting why rational drug design has been so difficult.

"The situation is akin to the discussion in astrophysics in which theoreticians predict that there is dark matter, or energy, that no one has yet seen," says senior author A. Joshua Wand, PhD, Benjamin Rush Professor of Biochemistry. "Biological theoreticians have been kicking around the idea that proteins have energy represented by internal motion, but no one can see it. We figured out how to see it and have begun to quantify the so-called 'dark energy' of proteins".

Proteins are malleable in shape and internal structure, which enables them to twist and turn to bind with other proteins. "The motions that we are looking at are very small, but very fast, on the time scale of billions of movements per second," explains Wand. "Proteins just twitch and shake." The internal motion represents a type of energy called entropy.

Current models of protein structure and function used in research and drug design often do not account for their non-static nature. "The traditional model is almost a composite of all the different conformations a protein could take," says Wand.........

Posted by: Nora      Read more         Source

Mon, 16 Jul 2007 03:01:45 GMT

Blue leaves....

Blue leaves....
Who hasn't wondered if there is life elsewhere in the universe? What would it look like? How would it function? Through biology, especially evolutionary biology, we can make educated guesses as to the form and function of the flora and fauna of other worlds. Kiang et al. go a step further, into a realm seldom imagined. They calculated the photosynthetically relevant radiation on earth-like planets orbiting other stars. The results are surprising. Different stars have different optimal photo spectra. Therefore, plant colors on other worlds might be different from plants on earth to capitalize on these differences. This would no doubt have cascading effects to all other species on those planets. Imagine blue lizards adapted to hide among blue leaves, and the birds adapted to find them.

Photo by Vincent Lillis.

Posted by: Dennehy      Read more     Source

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