October 15, 2008, 5:21 PM CT

Buckypapers clarify electrical, optical behavior of nanotubes

Using highly uniform samples of carbon nanotubessorted by centrifuge for lengthmaterials researchers at the National Institute of Standards and Technology (NIST) have made some of the most precise measurements yet of the concentrations at which delicate mats of nanotubes become transparent, conducting sheets. Their recent experiments* point up the importance of using relatively homogeneousnot overly short, but uniform in length nanotubes for making high performance conducting films.

Among their other qualities, single-wall carbon nanotubes (SWCNTs) have attracted much attention as tiny electrical conductors. Relatively small concentrations of nanotubes can change a normally insulating polymer film to a transparent electrical conductor. Potential applications range from transparent electrical shielding materials to futuristic flexible video displays, thin-film chemical sensors and other foldable electronics. One key design parameter for conductive films is the so-called percolation thresholdessentially the concentration at which random two- or three-dimensional networks of nanotubes first become electrically conducting.

To test theories on how both the conductance and optical properties of such nanotube-infused films depend on the length of the tubes, the NIST team made samples of buckypaper by mixing nanotubes in water and draining the water away through nanoscale filters to leave behind a delicate nanotube mat. The highly refined, length-sorted nanotube samples were produced by an efficient technique developed earlier by the NIST group (see Spin Control: New Technique Sorts Nanotubes by Length)......... Posted by: Beverly      Read more         Source

Fri, 10 Oct 2008 04:07:08 GMT

Merendera montana

....and another thank you to Paulo Araújo of Portugal for sharing a few of his photographs. Paulo submitted these images via this thread in the Botany Photo of the Day Submissions Forum. Much appreciated!

Paulo writes:

"The sight in early autumn of these stalkless flowers sprouting directly from the parched earth amidst dried-up grasses is quite wonderful. In spite of appearances, these plants do have leaves - but they will only show up much later, in spring. There are a number of synonyms for Merendera montana (among them Merendera pyrenaica and Colchicum bulbocodioides) and I don''t know which one is currently accepted ( Daniel -- RHS Plant Finder seems to agree with the posted name). Whatever its name, it only occurs in mountain pastures and other high open places in the Iberian Peninsula. These photos were taken at the end of September in Serra do Alvão, in the northern half of Portugal."

"I am including a third photograph to give you an idea of the kind of environment these flowers were found in. The granite outcrop is quite typical of the region; heather, gorse and bracken are to be seen on the foreground; the pine tree is a small Pinus sylvestris (which, although not native, has been planted extensively since the 19th century in our northern mountains and is now naturalized)."

Wikimedia has a few more images of Merendera montana. To read about the "protocooperative" relationship between Merendera montana and Microtus duodecimcostatus, a mole-vole, see: Gomez-García D., et al. 2004. How does Merendera montana (L.) Lange (Liliaceae) benefit from being consumed by mole-voles?. Vegetatio. 172(2):173-181. doi: 10.1023/B:VEGE.0000026325.93477.45 . Posted by: Daniel Mosquin      Read more     Source

October 7, 2008, 10:35 PM CT

Egg whites solve the 3-D problem

The real world is three-dimensional. That's true even in the laboratory, where researchers have to grow cells to study how they develop and what happens when their growth is abnormal.

More and more laboratories are seeking to develop three-dimensional cell culture systems that allow them to test their new techniques and drugs in a system that more closely mimics the way in which cells grow. However, a big sticking point is the cost of commercial media for growing such cultures.

Dr. Steffi Oesterreich, associate professor in the Lester and Sue Smith Breast Center at Baylor College of Medicine, and Dr. Benny A. Kaipparettu, a postdoctoral associate in her laboratory, found a solution chicken egg whites. Their process has garnered attention in other laboratories around the world. A report on their technique appeared in a recent issue of the journal BioTechniques, which featured their article on its cover.

"It's important because the architecture of the cell is different in two dimensions in comparison to three," she said. "Understanding how the cell communicates, how protein work requires three dimensions".

For example, breast cells in the mammary gland form ducts through which milk flows when a woman breastfeeds.

"These are the same cells that cause cancer," said Oesterreich. "When you put these cells in the egg white preparation, it forms a structure like a duct. In the two-dimensional form, the cells cannot form a duct"......... Posted by: Beverly      Read more         Source

Tue, 07 Oct 2008 03:24:08 GMT

Ferocactus cylindraceus

Thanks to Ruth for both today''s write-up and photograph:

Normally, television imitates life. It polishes the edges of life''s reality and makes it seem more glamorous. Well, here is an example of life imitating television, edges and all! I call this the "Homer Cactus" after Homer Simpson. I found this beauty in the Anza-Borrego desert in southern California while hiking with a group of friends. We had a great laugh!

The red barrel cactus, Ferocactus cylindraceus, is found in Arizona, California and northern Mexico at elevations of 600-1500 meters (2000-5000 feet). It is found growing amongst phenomenal species such as Joshua trees (Yucca brevifolia) in the Mojave desert and amongst the Fouquieria splendens (ocotillo) in the Anza-Borrego and Ocotillo Wells deserts. This species of barrel cactus can tolerate temperatures as low as -7 ºC (20 ºF). Deserts of southwestern USA and northern Mexico often receive massive flash floods and extreme heat. Ferocactus tend to grow slightly tilted toward the south, because of the additional sun exposure. If you are ever lost in the desert without a compass, remember to look for this feature to find south.

Ferocactus cylindraceus can reach a height of 2.5 meters (8 feet) with a width of up to 30 cm (12 inches). Blooms found on the top of the cylinder, like a hat, are yellow, red or orange. In general, spring is the best time to view wildflowers in the desert, but these cactuses bloom a bit later in July and late summer.

For more information, read the Flora of North America account for Ferocactus cylindraceus. Additional photographs are available from Calphotos: Ferocactus cylindraceus. Posted by: Daniel Mosquin      Read more     Source

September 18, 2008, 9:12 PM CT

Doppler on Wheels Deployed at Hurricane Ike

The only scientific team to successfully brave Hurricane Ike's knock-down winds and swells in Galveston was the DOW, the Doppler on Wheels mobile weather radar operated by the Center for Severe Weather Research (CSWR) in Boulder, Colo.

"The DOW mission to Ike provided, for the first time, high-resolution radar data collected from the ground of the inside of a hurricane eye strengthening during landfall, and from a hurricane that directly impacted a large urban area," said scientist Josh Wurman of CWSR.

The National Science Foundation (NSF)-supported DOW was deployed on a 35-foot-high overpass in Galveston during the passage of Ike.

"The mission will allow scientists to better understand how phenomena called fine-scale wind streaks and boundary layer rolls, discovered by the the DOW in 1996, affect hurricane evolution," said Steve Nelson, program director in NSF's Division of Atmospheric Sciences, which funds the DOW. "These rolls may be important in how efficiently heat is extracted from the ocean, and how strongly hurricane winds are slowed by surface friction".

The DOW collected data for 17 hours. The center of Ike's eye passed nearly directly over the DOW, allowing researchers to take measurements of the front and rear eyewalls, and of the inside of the eye......... Posted by: Beverly      Read more         Source

Wed, 17 Sep 2008 03:58:25 GMT

Brunsvigia josephinae

Thanks again to Ruth S. for today''s write-up. Also, big thanks to J.G. in S.F.@Flickr for sharing two of his photographs with us today (original 1 | original 2 via the BPotD Flickr Group Pool). Appreciated once again!

Ruth writes (touching on a topic introduced last week -- geophytes):

Geophyte (geo- or earth and -phyte or plant) is a term used to describe plants with underground storage organs. The term most people commonly use for these underground storage organs is "bulb", but, scientifically, the terminology is extensive. For example, in Gladiolus, the organs are actually corms, while in Iris, they are typically rhizomes. Brunsvigia josephinae, it so happens, has a true bulb.

Also known as Josephine''s lily or the candelabra lily, this member of the Amaryllidaceae is a winter grower from western South Africa. During the winter rainy season, the leaves emerge and help provide food to the bulb. The leaves die back in the early summer before flowers shoot up in later summer months (note: the apparent leaves at the base of the plants belong to different plants: Aloe mitriformis). Plants of Brunsvigia josephinae are able to survive through extremely low temperatures as well as drought outside of the rainy season due to their specialized energy storage organ.

The floral architecture is arranged in just the right way to seduce sugar-birds. The birds attracted by the red color, then search out the sugars in the nectary spur (the tube opposite the petals) of the flowers. Upon visiting the flower, they clumsily transfer pollen from the anthers to the stigma, thereby fertilizing the flower. If one was to grow the flowers in areas supporting hummingbirds, they would be the most likely pollinators.

For more, read about Brunsvigia josephinae on Plantzafrica or view more photographs via PBSWiki: Brunsvigia. Posted by: Daniel Mosquin      Read more     Source

Wed, 17 Sep 2008 03:49:37 GMT

Did You Read Your Toast This Morning?

Let me start by saying that this is only a concept - but it is a freaking cool one. Imagine being able to print on toast. You read correctly - what if you could take images from from the internet or your computer and print (burn them into) toast. Hear me out; it is not as silly as it sounds.

This design competition finalist, in a competition by Electrolux, has some fantastic potential. Designer Sung Bae Chang's design would allow you to print images or designs on food for weddings, parties, or simply to entertain friends. Taken to the extreme, this device could be used to print a mornings news on your toast so you could completely streamline your mornings.

Ok, so it does sound a little silly, but I still think it is cool. The way this USB equipped toaster works, is there are a series of burning "modules" that can adjust themselves to print (by cooking) into the bread. Technically, any image could be displayed on your bread. It could make for the most entertaining BLT you have ever read eaten.

Source. Posted by: Chris Matier      Read more     Source

September 10, 2008, 8:46 PM CT

First beam for Large Hadron Collider

An international collaboration of researchers today sent the first beam of protons zooming at nearly the speed of light around the world's most powerful particle acceleratorthe Large Hadron Collider (LHC)located at the CERN laboratory near Geneva, Switzerland. The U.S. Department of Energy (DOE) and the National Science Foundation (NSF) invested a total $531 million in the construction of the accelerator and its detectors, which researchers believe could help unlock extraordinary discoveries about the nature of the physical universe.

Celebrations across the U.S. and around the world mark the LHC's first circulating beam, an occasion more than 15 years in the making. An estimated 10,000 people from 60 countries have helped design and build the accelerator and its massive particle detectors, including more than 1,700 scientists, engineers, students and technicians from 94 U.S. universities and laboratories supported by DOE's Office of Science and NSF.

"As the largest and most powerful particle accelerator on Earth, the LHC represents a monumental technical achievement," said U.S. Department of Energy Undersecretary for Science Raymond L. Orbach. "I congratulate the world's researchers and engineers who have made contributions to the construction of the accelerator for reaching this milestone. We now eagerly await the results that will emerge from operation of this extraordinary machine"......... Posted by: Beverly      Read more         Source

August 31, 2008, 8:27 PM CT

Ice Age lesson predicts a faster rise in sea level

if the lessons being learned by researchers about the demise of the last great North American ice sheet are correct, estimates of global sea level rise from a melting Greenland ice sheet may be seriously underestimated.

Writing this week (Aug. 31) in the journal Nature Geoscience, a team of scientists led by University of Wisconsin-Madison geologist Anders Carlson reports that sea level rise from greenhouse-induced warming of the Greenland ice sheet could be double or triple current estimates over the next century.

"We're not talking about something catastrophic, but we could see a much bigger response in terms of sea level from the Greenland ice sheet over the next 100 years than what is currently predicted," says Carlson, a UW-Madison professor of geology and geophysics. Carlson worked with an international team of researchers, including Allegra LeGrande from the NASA Center for Climate Systems at Columbia University, and his colleagues at the Woods Hole Oceanographic Institution, the California Institute of Technology, University of British Columbia and University of New Hampshire.

Researchers have yet to agree on how much melting of the Greenland ice sheet a terrestrial ice mass encompassing 1.7 million square kilometers will contribute to changes in sea level. One reason, Carlson explains, is that in recorded history there is no precedent for the influence of climate change on a massive ice sheet......... Posted by: Beverly      Read more         Source

August 25, 2008, 10:02 PM CT

Research breeder develops drought-tolerant corn

At the end of the day, drought tolerance in corn has to equate to good yields and good quality, not just good looks, said a Texas AgriLife Research scientist.

Dr. Wenwei Xu, AgriLife Research corn breeder from Lubbock, is working with crosses between temperate and tropically adapted varieties of corn to find a drought-tolerant plant that performs well under reduced irrigation.

"With the continuing decline of the Ogallala Aquifer water level and increasing cost of pumping water, the use of drought-tolerant and high-yield corn hybrids is a key for sustainable corn production under limited irrigation," Xu said.

A field day was held recently at the North Plains AgriLife Research Station near Etter to demonstrate the differences between the parent plants and the offspring, or crosses.

"We hope to reduce the amount of water mandatory for corn by at least 10 percent," Xu said.

Already the AgriLife Research program out of Lubbock has released four inbred lines of corn and numerous others are in the process for release, he said.

"The new multiple-stress-tolerant corn lines can be used to produce corn hybrids adapted to Texas and other southern states," Xu said. "They can be a powerful tool to save water and produce crops with yield and grain quality under stressful environments"......... Posted by: Beverly      Read more         Source