Thu, 03 Jul 2008 23:04:27 GMT

Drosanthemum bicolor

Nhu Nguyen, aka xerantheum@Flickr is the photographer behind today''s image (original via BPotD Flickr Group Pool).Thank you!

The common name for Drosanthemum is dew-flower, which also happens to a literal translation of the name of the genus (drosos meaning dew and anthos meaning flower). This is in reference to the glistening papillae found on branches and flowering stems -- you can see this phenomenon in today''s photograph with a close look at the topmost unopened flower bud.

Although native to South Africa, one species of Drosanthemum (not D. bicolor) has naturalized in California, so the Flora of North America has an entry on the genus: Drosanthemum. Posted by: Daniel Mosquin      Read more     Source

Thu, 03 Jul 2008 15:46:57 GMT

Yucca brevifolia

By special request (from a conversation with a friend on the weekend), here''s an infrared photograph of Yucca brevifolia (along with a non-IR photograph of the inflorescence).

Joshua trees have made a previous appearance on BPotD in a brief entry on Joshua Tree National Park. In the comments section, Bill Hooker of Open Reading Frame suggested this article by Chris Clarke on Creek Running North: Joshua trees and extinction. In a bit of coincidence, during the same month that Chris wrote his piece, a journal article came out that suggested things are a bit more hopeful for the Joshua tree than was thought at the time. See: Vander Wall et al. 2006. Joshua tree (Yucca brevifolia) seeds are dispersed by seed-caching rodents. Ecoscience. 13(4): 539-543.

Since it''s a well-known plant from California (and also Arizona, Utah, Nevada and Baja California), excellent resources for more information exist: Calphotos, the Fire Effects Information System factsheet, and the Flora of North America: Yucca brevifolia. Posted by: Daniel Mosquin      Read more     Source

July 1, 2008, 9:59 PM CT

New DNA weapon against avian flu

Scientists at the University of Pennsylvania School of Medicine have identified a potential new way to vaccinate against avian flu. By delivering vaccine via DNA constructed to build antigens against flu, along with a minute electric pulse, scientists have immunized experimental animals against various strains of the virus. This approach could allow for the build up of vaccine reserves that could be easily and effectively dispensed in case of an epidemic. This study was published last week in PLoS ONE

"This is the first study to show that a single DNA vaccine can induce protection against strains of pandemic flu in a number of animal models, including primates," says David B. Weiner, Ph.D., Professor of Pathology and Laboratory Medicine. "With this type of vaccine, we can generate a single construct of a pandemic flu vaccine that will give much broader protection".

Traditional vaccines expose a formulation of a specific strain of flu to the body so it can create immune responses against that specific strain. On the other hand, a DNA vaccine becomes part of the cell, giving it the blueprint it needs to build antigens that can induce responses that target diverse strains of pandemic flu.

Avian flu is tricky. Not only is it deadly, but it mutates quickly, generating different strains that escape an immune response targeted against one single strain. Preparing effective vaccines for pandemic flu in advance with either live or killed viruses, which protect against only one or few cross-strains, is therefore very difficult. How to predict which strain of avian flu may appear at any time is difficult. "We are always behind in creating a vaccine that can effectively protect against that specific strain," notes Weiner......... Posted by: Nora      Read more         Source

June 26, 2008, 8:35 PM CT

Porous Nanostructures For Better Fuel Cells

For 5,000 years or so, the only way to shape metal has been to "heat and beat." Even in modern nanotechnology, working with metals involves carving with electron beams or etching with acid.

Now, Cornell scientists have developed a method to self-assemble metals into complex nanostructures. Applications include making more efficient and cheaper catalysts for fuel cells and industrial processes and creating microstructured surfaces to make new types of conductors that would carry more information across microchips than conventional wires do.

The method involves coating metal nanoparticles -- about 2 nanometers (nm) in diameter -- with an organic material known as a ligand that allows the particles to be dissolved in a liquid, then mixed with a block co-polymer (a material made up of two different chemicals whose molecules link together to solidify in a predictable pattern). When the polymer and ligand are removed, the metal particles fuse into a solid metal structure.

"The polymer community has tried to do this for 20 years," said Ulrich Wiesner, Cornell professor of materials science and engineering, who, with colleagues, reports on the new method in the June 27 issue of the journal Science. "But metals have a tendency to cluster into uncontrolled structures. The new thing we have added is the ligand, which creates high solubility in an organic solvent and allows the particles to flow even at high density"......... Posted by: John      Read more         Source

June 26, 2008, 8:29 PM CT

Standards Set for Energy-Conserving LED Lighting

Researchers at the National Institute of Standards and Technology (NIST), in cooperation with national standards organizations, have taken the lead in developing the first two standards for solid-state lighting in the United States. This new generation lighting technology uses light-emitting diodes (LEDs) instead of incandescent filaments or fluorescent tubes to produce illumination that cuts energy consumption significantly.

Standards are important to ensure that products will have high quality and their performance will be specified uniformly for commerce and trade. These standards-the most recent of which published last month-detail the color specifications of LED lamps and LED light fixtures, and the test methods that manufacturers should use when testing these solid-state lighting products for total light output, energy consumption and chromaticity, or color quality.

Solid-state lighting is expected to significantly reduce the amount of energy needed for general lighting, including residential, commercial and street lighting. "Lighting," explains NIST scientist Yoshi Ohno, "uses 22 percent of the electricity and 8 percent of the total energy spent in the country, so the energy savings in lighting will have a huge impact".

Solid-state lighting is expected to be twice as energy efficient as fluorescent lamps and 10 times more efficient than incandescent lamps, eventhough the current products are still at their early stages. Ohno chaired the task groups that developed these new standards......... Posted by: John      Read more         Source

June 23, 2008, 7:00 PM CT

Discovery could enable development of faster computers

Physicists at UC Riverside have made an accidental discovery in the lab that has potential to change how information in computers can be transported or stored. Dependent on the "spin" of electrons, a property electrons possess that makes them behave like tiny magnets, the discovery could help in the development of spin-based semiconductor technology such as ultrahigh-speed computers.

The researchers were experimenting with ferromagnet/semiconductor (FM/SC) structures, which are key building blocks for semiconductor spintronic devices (microelectronic devices that perform logic operations using the spin of electrons). The FM/SC structure is sandwich-like in appearance, with the ferromagnet and semiconductor serving as microscopically thin slices between which lies a thinner still insulator made of a few atomic layers of magnesium oxide (MgO).

The researchers found that by simply altering the thickness of the MgO interface they were able to control which kinds of electrons, identified by spin, traveled from the semiconductor, through the interface, to the ferromagnet.

Study results appear in the June 13 issue of Physical Review Letters

Experimental results:

The spin of an electron is represented by a vector, pointing up for an Earth-like west-to-east spin; and down for an east-to-west spin......... Posted by: John      Read more         Source

June 19, 2008, 9:15 PM CT

Tiny refrigerator taking shape to cool future computers

Researchers at Purdue University are developing a miniature refrigeration system small enough to fit inside laptops and personal computers, a cooling technology that would boost performance while shrinking the size of computers.

Unlike conventional cooling systems, which use a fan to circulate air through finned devices called heat sinks attached to computer chips, miniature refrigeration would dramatically increase how much heat could be removed, said Suresh Garimella, the R. Eugene and Susie E. Goodson Professor of Mechanical Engineering.

The Purdue research focuses on learning how to design miniature components called compressors and evaporators, which are critical for refrigeration systems. The researchers developed an analytical model for designing tiny compressors that pump refrigerants using penny-size diaphragms and validated the model with experimental data. The elastic membranes are made of ultra-thin sheets of a plastic called polyimide and coated with an electrically conducting metallic layer. The metal layer allows the diaphragm to be moved back and forth to produce a pumping action using electrical charges, or "electrostatic diaphragm compression".

In related research, the engineers are among the first to precisely measure how a refrigerant boils and vaporizes inside tiny "microchannels" in an evaporator and determine how to vary this boiling rate for maximum chip cooling......... Posted by: John      Read more         Source

April 28, 2008, 5:27 PM CT

'Sticky nanotubes' hold key to future technologies

Scientists at Purdue University are the first to precisely measure the forces mandatory to peel tiny nanotubes off of other materials, opening up the possibility of creating standards for nano-manufacturing and harnessing a gecko's ability to walk up walls.

So-called "peel tests" are used extensively in manufacturing. Knowing how much force is needed to pull a material off of another material is essential for manufacturing, but no tests exist for nanoscale structures, said Arvind Raman, an associate professor of mechanical engineering at Purdue.

Scientists are trying to learn about the physics behind the "stiction," or how the tiny structures stick to other materials, to manufacture everything from nanoelectronics to composite materials, "nanotweezers" to medical devices using nanotubes, nanowires and biopolymers such as DNA and proteins, he said.

Flexible carbon nanotubes stick to surfaces differently than larger structures because of attractive forces between individual atoms called van der Waals forces.

"Operating in a nanoscale environment is sort of like having flypaper everywhere because of the attraction of van der Waals forces," Raman said. "These forces are very relevant on this size scale because a nanometer is about 10 atoms wide"......... Posted by: John      Read more         Source

April 10, 2008, 8:06 PM CT

Waterman Award to UCLA's 'Mozart of Math'

The National Science Foundation (NSF) is proud to announce that 32-year-old Terence Tao, a professor of mathematics at the University of California at Los Angeles, will receive its 2008 Alan T. Waterman Award. Called a "supreme problem-solver," and named one of "the Brilliant 10" researchers by Popular Science (October 2006), Tao's extraordinary work, much of which has been funded by NSF through the years, has had a tremendous impact across several mathematical areas. He will receive the award at a black tie dinner program at the U.S. Department of State on May 6.

The annual Waterman award recognizes an outstanding young researcher in any field of science or engineering supported by NSF. Candidates may not be more than 35 years old, or seven years beyond receiving a doctorate, and must stand out for their individual achievements. In addition to a medal, the awardee receives a grant of $500,000 over a 3-year period for scientific research or advanced study in their field.

Terence Tao was born in Adelaide, Australia, in 1975. His genius at mathematics began early in life. He started to learn calculus when he was 7 years old, at which age he began high school; by the age of 9 he was already very good at university-level calculus. By the age of 11, he was thriving in international mathematics competitions. Tao was 20 when he earned his doctorate from Princeton University, and he joined UCLA's faculty that year. UCLA promoted him to full professor at age 24. Tao now holds UCLA's James and Carol Collins Chair in the College of Letters and Science. He is also a fellow of the Royal Society and the Australian Academy of Sciences (corresponding member)......... Posted by: John      Read more         Source

March 18, 2008, 4:54 AM CT

Fake Diamonds Help Jet Engines Take The Heat

Ohio State University engineers are in the process of developing a technology to coat jet engine turbine blades with zirconium dioxide -- usually called zirconia, the stuff of synthetic diamonds -- to combat high-temperature corrosion.

The zirconia chemically converts sand and other corrosive particles that build up on the blade into a new, protective outer coating. In effect, the surface of the engine blade constantly renews itself.

Ultimately, the technology could enable manufacturers to use new kinds of heat-resistant materials in engine blades, so that engines will be able to run hotter and more efficiently.

Nitin Padture, professor of materials science and engineering at Ohio State, said that he had military aircraft in mind when he began the project. He was then a professor at the University of Connecticut.

"In the desert, sand is sucked into the engines during takeoffs and landings, and then you have dust storms," he said. "But even commercial aircraft and power turbines encounter small bits of sand or other particles, and those particles damage turbine blades".

Jet engines operate at thousands of degrees Fahrenheit, and blades in the most advanced engines are coated with a thin layer of temperature-resistant, thermally-insulating ceramic to protect the metal blades. The coating -- referred to as a thermal-barrier coating -- is designed like an accordion to expand and contract with the metal......... Posted by: John      Read more         Source

March 9, 2008, 4:59 PM CT

Skewered Pumpkins

We encounter valves every day, whether in the water faucet, the carburetor in our car, or our bicycle tire tube. Valves are also present in the world of nanotechnology. A team of scientists headed by J. Fraser Stoddart and Jeffrey I. Zink at the University of California, Los Angeles, has now developed a new nanovalve. In the journal Angewandte Chemie, the researchers reveal what is special about it: In contrast to previous versions, which only function in organic solvents, this valve operates in an aqueous environment and under physiological conditions-prerequisites for any application as a gate for nanoscopic drug-transport agents, which need to set their cargo free at the right place and time.

In order for pharmaceuticals to affect only the target diseased organ, suitable nanopackaging is mandatory to bring the drug to the target area and release it only there. One example of a good nanoscopic packaging agent is a tiny sphere of porous silica. Its pores can be filled with the drug and closed with tiny controllable valves.

The researchers attached stem-shaped molecules onto the surface of the porous spheres and filled the pores with guest molecules. At neutral to acidic pH values, they stacked cucurbituril molecules onto these "stems". Cucurbituril is a fat, ring-shaped molecule reminiscent of a pumpkin that has both ends hollowed out. The resulting supramolecular structure, which resembles a skewered pumpkin and is known to chemists as a pseudorotaxane, blocks the pores, so that the guest molecules cannot exit. The nanovalve is closed......... Posted by: John      Read more         Source

March 5, 2008, 7:50 PM CT

Containing Carbon Dioxide

Injecting CO2, the most troublesome greenhouse gas, into porous rock formations beneath the earth might be the best short-term option for slowing global warming. Los Alamos scientists are developing a comprehensive risk assessment program to ensure safe and effective CO2 containment. This program includes a unique computer model, named "CO2-PENS," to guide the choice and development of the best sites; laboratory experiments to understand the geochemistry of sequestration systems; and field studies to quantify natural CO2 flux in the ecosystem. Los Alamos has advanced its geologic sequestration research by partnering with the Enhanced Oil Recovery Industry, which has injected CO2 underground for 30 years.

The average American family of four puts about three tons of garbage per year by the curb, but because we burn fossil fuels for electricity, heat, and transportation, that same family is annually responsible for dumping about 80 tons of carbon dioxide (CO2) into the atmosphere-CO2 that contributes to global climate change.

Some believe we should just stop using fossil fuels, but that won't happen in the near future unless we're willing to cripple our economy and keep the developing world in poverty. Eighty-six percent of the world's energy comes from fossil fuels, and projections show energy demand and fossil fuel use rising dramatically. China, India, and the United States are planning to add 850 new coal-fired power plants to the 2,100 worldwide that currently chug out one-third of the world's human-generated CO2 emissions......... Posted by: Nora      Read more         Source

Wed, 13 Feb 2008 01:37:38 GMT

Dicranopteris linearis

Thank you again to Krystyna Szulecka for sharing another of her excellent photographs (posted in this thread in the BPotD submissions forum). If you like, see more of Krystyna''s images by searching for “Krystyna” on the FLPA web site.

Given its distribution, it''s doubtless that Dicranopteris linearis has dozens of common names. Four names frequently used are Uluhe fern, climbing fern, false staghorn and Old World forked fern. According to GRIN, it can be found in tropical and subtropical areas throughout the Old World. That left me puzzled for a bit, as Plants of Hawaii Volcanoes National Park lists it as indigenous and the USDA PLANTS database displays it as native to Hawaii The mystery was partially resolved when I looked at GRIN''s entry for Dicranopteris linearis f. marginata, noted to be found in Hawaii. So, it appears to be a small oversight that Hawaii isn''t included in the broader distribution list.

The Plants of Hawaii Volcanoes National Park has a photograph clearly illustrating the reason for one of the common names, climbing fern. More photographs, particularly with respect to propagation, are available in the PDF suggested by Krystyna: The Propagation and Production of Uluhe Fern (Dicranopteris linearis) for Potential Use as a Restoration Species (a presentation given to the International Plant Propagators'' Society).

The New South Wales Flora Online provides a small scientific description of the species. Posted by: Daniel Mosquin      Read more     Source

January 29, 2008, 9:45 PM CT

Magnetism loses under pressure

Washington, D.C. Scientists have discovered that the magnetic strength of magnetitethe most abundant magnetic mineral on Earthdeclines drastically when put under pressure. Researchers from the Carnegie Institutions Geophysical Laboratory, together with colleagues at the Advanced Photon Source of Argonne National Laboratory, have found that when magnetite is subjected to pressures between 120,000 and 160,000 times atmospheric pressure its magnetic strength declines by half. They discovered that the change is due to what is called electron spin pairing.

Magnetism comes from unpaired electrons in magnetic materials. The strength of a magnet is a result of the spin of unpaired electrons and how the spins of different electrons are aligned with one another. This research showed that the drop in magnetism was due to a decrease in the number of unpaired electrons.

Magnetite is found in small quantities in certain bacteria, in brains of some birds and insects, and even in humans, commented Yang Ding, the studys lead author with the Carnegie-led High-Pressure Synergetic Consortium. Early navigators used it to find the magnetic North Pole and birds use it for their navigation. And now it is used in nanotechnology. There is intense scientific interest in its properties. Understanding the behavior of magnetite is difficult because the strong interaction among its electrons complicates its electronic structure and magnetic properties......... Posted by: Nora      Read more         Source

December 20, 2007, 9:36 PM CT

Proton Camera

Lab researchers, working with Teledyne Imaging Sensors, have built the world's fastest camera, and it has just won an R&D 100 Award from R&D Magazine as one of the 100 most technologically significant products of 2007.

Made from two bonded microelectronic chips, the "Camera on a Chip" can capture 2.8 million frames per second. A normal motion picture camera captures 24 frames per second.

The camera produces movies of ultra-short (sub-microsecond) processes, mostly induced by powerful high explosives. These processes are studied using a remarkable imaging technique known as proton radiography, in which high-energy protons pass through an explosives-driven object to a screen, where they produce a blue "shadowgraph," essentially a two-dimensional representation of the object.

The camera takes pictures of the shadowgraphs in as little as 50 billionths of a second per frame, freezing images of the object's high-speed motions and storing up to three of them "on-chip" at one time. Several cameras can be used together to make a movie of tens of frames or more.

With very high sensitivity in both the visible and near-visible frequencies, the camera can also be used for a number of other applications, including studies of internal-combustion engines, vehicle-impact tests, and armor-penetration experiments; laser-beam identification of minerals on Mars; and location of fast-moving targets in space......... Posted by: John      Read more         Source

December 12, 2007, 10:04 PM CT

Nanoscale Details of Photolithography Process

Researchers at the National Institute of Standards and Technology (NIST) have made the first direct measurements of the infinitesimal expansion and collapse of thin polymer films used in the manufacture of advanced semiconductor devices. It's a matter of only a couple of nanometers, but it can be enough to affect the performance of next-generation chip manufacturing. The NIST measurements, detailed in a new paper,* offer a new insight into the complex chemistry that enables the mass production of powerful new integrated circuits.

The smallest critical features in memory or processor chips include transistor "gates." In today's most advanced chips, gate length is about 45 nanometers, and the industry is aiming for 32-nanometer gates. To build the nearly one billion transistors in modern microprocessors, manufacturers use photolithography, the high-tech, nanoscale version of printing technology. The semiconductor wafer is coated with a thin film of photoresist, a polymer-based formulation, and exposed with a desired pattern using masks and short wavelength light (193 nm). The light changes the solubility of the exposed portions of the resist, and a developer fluid is used to wash the resist away, leaving the pattern which is used for further processing.

Exactly what happens at the interface between the exposed and unexposed photoresist has become an important issue for the design of 32-nanometer processes. Most of the exposed areas of the photoresist swell slightly and dissolve away when washed with the developer. However this swelling can induce the polymer formulation to separate (like oil and water) and alter the unexposed portions of the resist at the edges of the pattern, roughening the edge. For a 32-nanometer feature, manufacturers want to hold this roughness to at most about two or three nanometers......... Posted by: John      Read more         Source

Thu, 13 Dec 2007 03:14:46 GMT

Ricinus communis cultivar

Anne from Alberta (aka annkelliott@Flickr) shares another of her great images with BPotD (original | BPotD Flickr Group Pool). Thank you, Anne!

As a child, I thought castor oil was an extract from animals (beavers, specifically). I suppose I can blame that on childhood logic after learning the French name for beaver. It was only much later when I learned that it was a plant derivative from the species in today''s photograph, Ricinus communis, or the castor bean plant. Wikipedia provides a detailed summary of the chemistry and uses of castor oil. In particular, the use as an instrument of intimidation is both interesting and disgusting.

Despite the many uses of castor oil, Ricinus communis also happens to contain a deadly poison, ricin. The entire plant is poisonous if ingested, but the seeds are particularly potent; one chewed seed may be enough to kill a child, see: ricin toxin. The Cornell web site also contains a page about the plant itself, Ricinus communis, where it explains that ricin is water-soluble and hence will not find its way into castor oil during the production process provided proper precautionary measures are taken (thanks to Anne for the link, as well).

The widespread tropical and subtropical cultivation of Ricinus communis has made it difficult to determine its original distribution. The Handbook of Energy Crops, in addition to providing extensive details about cultivation and production, suggests Ricinus communis is African in origin. The comprehensive photographs of the species available on MissouriPlants.com are accompanied by a write-up suggesting an Asian origin. Posted by: Daniel Mosquin      Read more     Source

December 11, 2007, 8:35 PM CT

Software Helps Mars Rovers Find Winter Havens

New software is helping NASA find safe places for the Spirit rover to ride out future Martian winters -- and also plan where Spirit and its companion rover, Opportunity, will explore in the future.

The steep Martian mesa dubbed "Von Braun" would be a safe haven, the software and data analysis determined -- but the path that Spirit would have to follow to get there is a little too risky to travel with winter on the way, explained Ron Li, professor of civil and environmental engineering and geodetic science at Ohio State University.

That's one reason why Spirit is currently headed to the northern rim of a depression called "Home Plate" for the winter -- though, as of early December, it was rolling through loose soil that was hampering its progress.

Li and his research team are in the process of developing several software programs to help the rovers navigate. The latest program used satellite images, as well as rover images, to determine that Von Braun's more than 25-degree incline is steep enough for the rover's solar panels to gather critical energy from the low winter sun. But it also determined that there are no safe winter sites on the route to Von Braun where the rover could hide out in a pinch.

Should Spirit set out on the 400-foot journey to Von Braun and not be able to reach it, there are not enough bail out spots along the route where it could take refuge, the software found. Even in ideal driving conditions, the trip would take many days. And with the winter approaching, Spirit might need to stop at steep slopes where it could better angle its solar panels to gather light......... Posted by: Edwin      Read more         Source

December 10, 2007, 10:31 PM CT

MIT creates oil-repelling materials

MIT engineers have designed a class of material structures that can repel oils, a novel discovery that could have applications in aviation, space travel and hazardous waste cleanup. Such materials could be used to help protect parts of airplanes or rockets that are vulnerable to damage from being soaked in fuel, like rubber gaskets and o-rings.

"These are vulnerable points in a number of aerospace applications," said Robert Cohen, the St. Laurent Professor of Chemical Engineering and an author of a paper on the work that appeared in the Dec. 7 issue of Science.

"It would be nice if you could spill gasoline on a fabric or a gasket or other surface and find that instead of spreading, it just rolled off," Cohen said.

Creating a strongly oil-repelling, or "oleophobic" material, has been challenging for scientists, and there are no natural examples of such a material.

"Nature has developed a lot of methods for waterproofing, but not so much oil-proofing," said Gareth McKinley, MIT School of Engineering Professor of Teaching Innovation in the Department of Mechanical Engineering and a member of the research team. "The conventional wisdom was that it couldn't be done on a large scale without very special lithographic processes".

The tendency of oils and other hydrocarbons to spread out over surfaces is due to their very low surface tension (a measure of the attraction between molecules of the same substance)......... Posted by: John      Read more         Source

Mon, 10 Dec 2007 04:21:34 GMT

Hibiscus clayi

A thank you to frolickauai@Flickr for today''s first-time contribution to Botany Photo of the Day (original | BPotD Flickr Group Pool). Much appreciated! Do investigate frolickauai''s other photographs on Flickr – plenty of plant photographs.

Hibiscus clayi, or Clay''s hibiscus (or Hawaiian red hibiscus), is an extremely rare plant in the wild; as frolickauai notes: “This flower is on one of only four naturally occurring members of Hibiscus clayi in the wild.”. The wild, in this case, is Kaua‘i, Hawaii. Conservation efforts are underway to expand the population beyond the four individuals, and botanical gardens in the area are part of the effort (ref: US Botanical Garden summary). Despite being in a forest reserve, the remaining individuals remain under threat. The profile of Hibiscus clayi on the US Center for Plant Conservation notes that competition with alien plants is the current major problem, although the initial decline was due in large part to cattle grazing (cattle are no longer a threat, though feral pigs are another issue).

The Plants of Hawaii site contains photographs of Hibiscus clayi in cultivation, as well as a resource page about the species. Posted by: Daniel Mosquin      Read more     Source

December 7, 2007, 9:33 PM CT

James Webb Space Telescope Testing

A model of the James Webb Space Telescope's Mid-InfraRed Instrument will be tested before Christmas at the Rutherford Appleton Laboratory in Oxfordshire, England to ensure the final instrument can see infrared light.

Observing the universe in the infrared light portion of the spectrum is important because a number of objects researchers want to observe in space are far too cold to radiate at shorter wavelengths that can be seen as visible light, but they radiate strongly in infrared light.

The Mid-InfraRed Instrument (MIRI) is one of four sophisticated instruments onboard the Webb telescope which will study the early universe and properties of materials forming around new born stars in unprecedented detail. It will also be able to image directly massive planets orbiting other stars.

Speaking at the 3rd Appleton Space Conference on Dec. 6, European Consortium Lead for MIRI, Dr. Gillian Wright from the U.K. Astronomy Technology Centre (ATC) in Edinburgh said, "It is extremely exciting, after working on the project since 1998, to begin to test a complete instrument. This will provide researchers with real data which they can use to understand the best ways of making discoveries with the instrument".

MIRI's development is an effort between NASA and the European Space Agency (ESA). NASA's Jet Propulsion Laboratory in Pasadena (JPL), Calif, leads the NASA effort and is responsible for the development of MIRI's detectors, its cryocooler, and flight software......... Posted by: Edwin      Read more         Source

November 27, 2007, 10:17 PM CT

Fatigue effects in silicon

Scientists at the National Institute of Standards and Technology (NIST) have demonstrated a mechanical fatigue process that eventually leads to cracks and breakdown in bulk silicon crystalsa phenomenon thats especially interesting because it long has been thought not to exist. Their recently published* results have important implications for the design of new silicon-based micro-electromechanical system (MEMS) devices that have been proposed for a wide variety of uses.

Siliconthe backbone of the semiconductor industryis one the worlds most heavily studied materials, and it has long been thought to beimmune to fatigue from cyclic stresses because of the nature of its crystal structure and chemical bonds. And indeed, conventional tests have validated this. Recent research into silicon MEMS devices, however, has revealed that these microscopic systems that incorporate tiny gears, vibrating reeds and other mechanical features do seem to develop stress-induced cracks that can lead to failure. Why this happens at the microscopic scale is a matter of debate. One school of thought holds that the effect is purely mechanical, due to friction, and the other argues that it essentially is caused by corrosiona chemical effect. Because the effect has only been noticed at submicrometer scales, it has been difficult to determine which theory is correct......... Posted by: John      Read more         Source

Tue, 20 Nov 2007 01:48:28 GMT

Lupinus breweri var. breweri

Thank you again to one of the good folks at the University of Colorado at Boulder for today''s image and write-up. Janice Forbis is the assistant manager of the greenhouse in U of C''s Department of Ecology and Evolutionary Biology. A big thank you to you, Janice!

Janice writes:

“Lupinus breweri var. breweri is native to the western USA (Oregon, California and Nevada) and found in open montane forests at higher elevations of the alpine. It is a member of the Fabaceae or bean family, the third largest family in the number of species. Brewer''s lupine is a low-growing mat-forming plant, with silvery-silky leaves and densely hairy blue to violet petals. Alpine plants are strongly adapted to extreme conditions at high altitudes. The mat-forming or cushion habit is an advantage in wind resistance and avoiding damage from repetitive snowfalls. Hairy leaves are a way of limiting water loss in alpine areas which have free draining soils, frequent winds and high temperatures in the summer months.”

“This photo was taken during a week-end workshop, Flora of Mt. Ashland and the Eastern Siskiyous, part of The University of California at Berkeley Jepson Herbarium Weekend Workshop series.”

“It is always interesting to know where a plant name comes from. There are websites and exhibits, such as the one currently at the University of Colorado Museum titled “What''s in a Name? Understanding the World of Plants”. The name breweri is in honor of William Henry Brewer (1828-1910), an American botanist and professor. He was a botanical explorer of the California and Pacific Coast and his recommendations about Alaska led to its purchase by the United States in 1867 (source of plant name information: Michael Charters'' Plant Names).” Posted by: Daniel Mosquin      Read more     Source

November 18, 2007, 8:56 PM CT

Local sources major cause of US near-ground aerosol pollution

A new NASA study estimates that most ground-level particulate pollution in the United States stems from regional sources in North America and only a small amount is brought to the country from other parts of the world.

Scientists using an innovative global aerosol tracking model have for the first time produced a global estimate of sources and movements of aerosols near the ground where they can affect human health and run afoul of environmental regulations. Previously, scientists studying aerosols moving between continents focused primarily on tracking a single type of aerosol, such as dust or black carbon, or measuring their quantities throughout the atmosphere. This left gaps in understanding where ground-level particulate pollution comes from.

"This is the first study to comprehensively consider the origin, composition and type of fine particles over the United States and connect them to both domestic and foreign sources." said Mian Chin, an atmospheric scientist at NASAs Goddard Space Flight Center, Greenbelt, Md., and lead author of the study.

Aerosols are airborne particles that arise from both human sources such as burning fossil fuels, and natural sources such as fires, dust and volcanoes. They are also a major source of near-ground pollution. Since 1970, particulate matter has been regulated in the United State s by the Clean Air Act. A more recent concern has been aerosols that arrive here from distant shores carried by the wind......... Posted by: Nora      Read more         Source

November 18, 2007, 8:45 PM CT

Seven-year-old becomes 'scientist for a day'

When I grow up, I want to be a scientist. How a number of MIT students uttered these words when they were children? Though not an MIT student, Juliana Bach, a 7-year-old from Miami, discovered her passion for science at a young age. On Tuesday, Nov. 13, MIT, in conjunction with the Make-A-Wish Foundation, made her wish to be a scientist come true.

As Juliana works in the lab, she looks like a miniature scientist, wearing a white lab coat with her name stitched across the front. With her earnest demeanor and straight posture, Juliana exhibits all the characteristics of an eager science student. The only indications of her young age are the pink pants peeking out from below her lab coat, the high ponytail swinging on top of her head, and her tiny infectious giggle. What her physical appearance and positive demeanor cannot tell you, however, is that Juliana has leukemia.

Juliana's parents approached the Make-A-Wish Foundation about her desire to be to a scientist and were promptly directed to MIT, which was delighted to host her on campus. Juliana's requests while at MIT were to experiment with chemical reactions, discover how liquids change color, find out why there are different colors of sand, and make "goop."

Juliana first met with Heidi Nepf, director of the Environmental Fluid Mechanics Lab and professor of civil and environmental engineering. Nepf worked with Juliana to demonstrate aspects of how water moves in rivers, lakes and the coastal zone. The experiments were all based on prior or current research in Nepf's laboratory, but scaled down in size and concept to be understandable to a 7-year-old......... Posted by: Nora      Read more         Source

November 18, 2007, 8:42 PM CT

'Noah's flood' kick-started European farming

The flood thought to bebehind the Noahs Ark myth kick-started European agriculture, as per new research by the Universities of Exeter, UK and Wollongong, Australia. Reported in the journal Quaternary Science Reviews, the research paper assesses the impact of the collapse of the North American (Laurentide) Ice Sheet, 8000 years ago. The results indicate a catastrophic rise in global sea level led to the flooding of the Black Sea and drove dramatic social change across Europe. The research team argues that, in the face of rising sea levels driven by contemporary climate change, we can learn important lessons from the past.

The collapse of the Laurentide Ice Sheet released a deluge of water that increased global sea levels by up to 1.4 metres and caused the largest North Atlantic freshwater pulse of the last 100,000 years. Before this time, a ridge across the Bosporus Strait dammed the Mediterranean and kept the Black Sea as a freshwater lake. With the rise in sea level, the Bosporus Strait was breached, flooding the Black Sea. This event is now widely thought to bebehind the various folk myths that led to the biblical Noahs Ark story. Archaeological records show that around this time there was a sudden expansion of farming and pottery production across Europe, marking the end of the Mesolithic hunter-gatherer era and the start of the Neolithic. The link between rising sea levels and such massive social change has previously been unclear......... Posted by: Nora      Read more         Source

November 14, 2007, 9:22 PM CT

effects of low dose arsenic on development

A team of Dartmouth Medical School (DMS) scientists has determined that low doses of arsenic disrupt the activity of a hormone critical in development. The finding is further evidence that arsenic at low doses (at levels found in U.S. drinking water in some areas) can be harmful. The study appeared in the Oct. 26, 2007, online edition of the journal Environmental Health Perspectives (EHP), and it will be published in a forthcoming issue of the journal.

"Arsenic is a natural, yet pervasive, chemical in the environment; we can't seem to escape it," says Joshua Hamilton, one of the authors on this study and the director of the Center for Environmental Health Sciences at Dartmouth and Dartmouth's Superfund Basic Research Program on Toxic Metals. "By learning how it adversely affects biological processes and at what levels we should be concerned, we will hopefully someday be able to mitigate its impact on human health." Hamilton is also a professor of pharmacology and toxicology at DMS.

Hamilton and his team, in prior work, have learned that arsenic at low doses appears to suppress the ability of all critical steroid receptors, including those for estrogen and testosterone, to respond to their normal hormone signals. Chemicals that disrupt steroid hormone receptor signaling are called endocrine disruptors. Arsenic can disrupt these hormone pathways at extremely low doses equivalent to what a number of people in the U.S. have in their drinking water......... Posted by: Nora      Read more         Source

October 24, 2007, 7:27 PM CT

NASA Views Southern California Fires and Winds

With a click of the mouse button, the public can see NASA views from space, including some at Google Earth, of Southern California's raging wildfires and the ferocious Santa Ana winds that are driving them.

Images taken by the Moderate Resolution Imaging Spectroradiometer (Modis) on NASA's Terra and Aqua satellites are processed daily and made available by the JPL OnEarth Web Map Server, and at Google Earth. This effort is part of an ongoing collaboration with JPL, Google Earth, and NASA Ames Research Center, Moffett Field, Calif., to make remote satellite imagery available to the public and decision makers. Latest Modis fire images at onearth.jpl.nasa.gov/socalfires......... Posted by: Edwin      Read more         Source

October 23, 2007, 10:04 PM CT

Fifty Times sharper than Hubble

M87, the central galaxy of the Virgo cluster in a distance of only 50 million light years, was observed by Yuri Kovalev from the Max Planck Institute for Radio Astronony (MPIfR) in Bonn and colleagues with the VLBA (Very Long Baseline Array) at 2 cm wavelength. The resulting image provides details down to a resolution of one milli-arcsecond, corresponding to a linear resolution of only three light months. The new image of the inner radio jet of M87 shows a highly collimated jet which appears limb-brightened, and also a faint counter-jet. It is unprecedented in its combination of sensitivity and spatial resolution.

The observations were performed with the Very Long Baseline Array (VLBA) of the National Radio Astronomy Observatory (NRAO), consisting of ten radio antennas in North America including Hawaii and Virgin Island and an additional telescope from the Very Large Array (VLA) near Socorro, New Mexico. The Effelsberg 100m radio telescope is regularly used for transatlantic baselines extending the VLBA observations. "With the 100m radio telescope, we plan to increase the spatial resolution and provide an even more detailed image of the M87 jet", says Yuri Kovalev......... Posted by: Edwin      Read more         Source

September 17, 2007, 10:37 PM CT

Volatile Organic Compounds In Water And Air

Scientists at the Georgia Institute of Technology have developed a miniature sensor that uses polymer membranes deposited on a tiny silicon disk to measure pollutants present in aqueous or gaseous environments. An array of these sensors with different surface coatings could be used during field-testing to rapidly detect a number of different chemicals.

Since this new sensor allows water and air samples to be analyzed in the field, it is an improvement over classical techniques that require samples be carried back to the laboratory for analysis. This research, funded by the National Science Foundation, was presented on August 20 at the American Chemical Societys 234th National Meeting.

The heart of the disk-shaped sensor is a microbalance that measures the mass of pollutant molecules.

When pollutant chemicals get adsorbed to the surface of the sensor, a frequency change of the vibrating microbalance provides a measure of the associated mass change, said Oliver Brand, associate professor in Georgia Techs School of Electrical and Computer Engineering.

Cantilever-type balances, which move up and down like a diving board, are common when measuring the amount of a chemical in the gas phase. However, the mechanical vibrations of the balance used to detect the mass changes are damped in liquids, causing the sensitivity of the balance to decrease. Thus, Brand and graduate students Jae Hyeong Seo, Stuart Truax and Kemal Safak Demirci searched for structures whose vibrations were less affected by the surrounding medium......... Posted by: Nora      Read more         Source