Friday, October 28, 2005

"Unidirectional molecular motor on a gold surface"


"Here we demonstrate that a light-driven molecular motor capable of repetitive unidirectional rotation ... can be mounted on the surface of gold nanoparticles. The motor design ... uses a chiral helical alkene with an upper half that serves as a propeller and is connected through a carbon-carbon double bond (the rotation axis) to a lower half that serves as a stator. The stator carries two thiol-functionalized 'legs', which then bind the entire motor molecule to a gold surface."

"A haplotype map of the human genome"

Nature: The International HapMap Consortium

"Abstract. Inherited genetic variation has a critical but as yet largely uncharacterized role in human disease. Here we report a public database of common variation in the human genome: more than one million single nucleotide polymorphisms (SNPs) for which accurate and complete genotypes have been obtained in 269 DNA samples from four populations, including ten 500-kilobase regions in which essentially all information about common DNA variation has been extracted. These data document the generality of recombination hotspots, a block-like structure of linkage disequilibrium and low haplotype diversity, leading to substantial correlations of SNPs with many of their neighbours. We show how the HapMap resource can guide the design and analysis of genetic association studies, shed light on structural variation and recombination, and identify loci that may have been subject to natural selection during human evolution."



A free-access supplement on sleep and the brain.

Quantitative Analysis of the Benefits and Risks of Consuming Farmed and Wild Salmon

Journal of Nutrition

"Contaminants in farmed Atlantic and wild Pacific salmon raise important questions about the competing health benefits and risks of fish consumption. A benefit-risk analysis was conducted to compare quantitatively the cancer and noncancer risks of exposure to organic contaminants in salmon with the (n-3) fatty acid-associated health benefits of salmon consumption."

Thursday, October 27, 2005

Galvanic Vestibular Stimulation


"The technology is called galvanic vestibular stimulation _ essentially, electricity messes with the delicate nerves inside the ear that help maintain balance.
I felt a mysterious, irresistible urge to start walking to the right whenever the researcher turned the switch to the right. I was convinced _ mistakenly _ that this was the only way to maintain my balance."

Friday, October 21, 2005

"New antifreeze protein may allow longer storage of transplant organs"

Press Release:Queen's University

"A new antifreeze protein discovered in tiny snow fleas by Queen's University researchers may lengthen the shelf life of human organs for transplantation.

"Drs. Laurie Graham and Peter Davies, from the Department of Biochemistry, found that the potent protein produced by the fleas to protect themselves against freezing is capable of inhibiting ice growth by about six Celsius degrees. This would allow organs to be stored at lower temperatures, expanding the time allowed between removal and transplant."

Tuesday, October 18, 2005

New NASA Map Provides More Evidence of Plate Tectonics on Mars

SpaceRef - Your Space Reference

"NASA scientists have discovered additional evidence that Mars once underwent plate tectonics, slow movement of the planet's crust, like the present-day Earth. A new map of Mars' magnetic field made by the Mars Global Surveyor spacecraft reveals a world whose history was shaped by great crustal plates being pulled apart or smashed together."

Free access to article at PNAS

Monday, October 17, 2005

"Swell magnet stokes support for wave power"

news @

"Hugh-Peter Kelly, the founder of Trident Energy, a small British company based in Southend-on-Sea, thinks his system might crack previous problems and allow wave energy to come of age.

His invention uses the up and down motion of a floating buoy to move an electrical coil along a stack of magnets, which generates an alternating current in the coil.

'At a stroke you get rid of all the hydraulics that the rotary generators used by other wave power devices need,' says Kelly. This should make the device relatively cheap and reliable, he says. And as the generator only moves up and down it takes up very little space, so a number of them could be crammed into a small area."

Sunday, October 16, 2005

UN & Cifor Find Relation between Deforestation and Flooding is Scale Dependent

BBC NEWS | Science/Nature

"The belief that deforestation causes major floods and increases the damage which they do appears to be widespread.
China's catastrophic floods of 1998, when the Yangtse and Yellow rivers broke their banks, were linked by Chinese officials to deforestation; the environmental group WWF and the Red Cross also drew a causal connection.
Italian politicians made similar statements after mudslides near Naples killed nearly 100 people in the same year.
But the FAO/Cifor report cites evidence from Bangladesh, Nepal, South Africa, Thailand and the US showing that the frequency and extent of major floods has not changed over the last century or two, despite drastic reductions in forest cover.
'I think the belief comes about because forests do help to reduce floods in small areas, and so people assume it must also apply to severe floods in large areas,' said Cifor's director-general David Kaimowitz."

Friday, October 14, 2005

NASA's Hubble Reveals Moon's Secrets

SpaceRef - Your Space Reference

"Using Hubble's Advanced Camera for Surveys, preliminary assessments suggest a newly discovered abundance of titanium and iron oxides. They may be sources of oxygen and a potential resource for human exploration. "

Forest Fungus Yields Powerful Antimicrobial

"A fungus found on the floor of northern European pine forests may soon rescue humans from some of the world's most stubborn diseases. The mushroom in question has yielded an antimicrobial peptide that researchers say has the curative powers of such antibiotic stalwarts as penicillin and vancomycin, and then some. In laboratory and animal tests, the peptide, called plectasin, effectively battled a number of bacteria, including strains that have become resistant to conventional antibiotics. "This particular antimicrobial peptide was extremely active against the organisms that causes pneumonia and the organisms that cause strep throat and certain types of severe skin infections," said Dr. Michael Zasloff, co-author of the study, which appears in the Oct. 13 issue of Nature. Zasloff is professor of surgery at Georgetown University Medical Center in Washington, D.C."

Further evidence for small-bodied hominins from the Late Pleistocene of Flores, Indonesia


"Homo floresiensis was recovered from Late Pleistocene deposits on the island of Flores in eastern Indonesia, but has the stature, limb proportions and endocranial volume of African Pliocene Australopithecus1. The holotype of the species (LB1), excavated in 2003 from Liang Bua, consisted of a partial skeleton minus the arms. Here we describe additional H. floresiensis remains excavated from the cave in 2004. These include arm bones belonging to the holotype skeleton, a second adult mandible, and postcranial material from other individuals. We can now reconstruct the body proportions of H. floresiensis with some certainty. The finds further demonstrate that LB1 is not just an aberrant or pathological individual, but is representative of a long-term population that was present during the interval 95–74 to 12 thousand years ago. The excavation also yielded more evidence for the depositional history of the cave and for the behavioural capabilities of H. floresiensis, including the butchery of Stegodon and use of fire."

Wednesday, October 12, 2005

NASA Discovers Life's Building Blocks Are Common In Space

SpaceRef - Your Space Reference

"A team of NASA exobiology researchers revealed today organic chemicals that play a crucial role in the chemistry of life are common in space.
'Our work shows a class of compounds that is critical to biochemistry is prevalent throughout the universe,' said Douglas Hudgins, an astronomer at NASA Ames Research Center, located in California's Silicon Valley. He is principal author of a study detailing the team's findings that appears in the Oct. 10 issue of the Astrophysical Journal."

Northrop Grumman-Boeing Team Unveils Plans for Crew Exploration Vehicle

SpaceRef - Your Space Reference

"WASHINGTON D.C. Oct. 12, 2005 A Northrop Grumman Corporation (NYSE: NOC)-The Boeing Company (NYSE: BA) team today unveiled its plans to design and build NASA's proposed Crew Exploration Vehicle (CEV), a modular space system intended to carry humans to the International Space Station by 2012 and back to the moon by 2018."

Monday, October 10, 2005

Nanotubes refine computer memory

news @ Manufacturers gear up to mass-produce unconventional chips.

"Will computers that require no time to boot up become a reality? One company thinks the answer is yes, thanks to its carbon nanotube memory chips.

Nantero presented its achievement at the Emerging Technologies Conference in Cambridge, Massachusetts. It uses rolled-up tubes of carbon to make transistors, the on-off switches that carry digital information inside computing chips: strings of the nanotubes move up and down to represent the ones and zeroes of binary code. Unlike the electrons in normal electrical transistors, these nanotubes stay in place even when a computer is turned off.

Nantero, based in Woburn, Massachusetts, has been working on the idea for years. Now they say they have made ground in the manufacturing process, pushing the chips closer to market.

The company has succeeded in making circular wafers, 13 centimetres in diameter, that hold 10 gigabits of data. These much bigger than equivalent memory cards used today. But Greg Schmergel, chief executive officer of Nantero, says the nanotube chips are ten times faster than 'flash' cards, which are some of the swiftest ones now available."

Viagra helps out endangered species

news @

"A recent survey shows that the western treatment for this sexual problem seems to be replacing more traditional medicines, including potions made from seal penises and reindeer antler velvet. This could be having a knock-on effect on the welfare of those animals, scientists say. However, conservationists largely remain unconvinced."

Saturday, October 08, 2005

Dynamic Properties of Network Motifs Contribute to Biological Network Organization

PLoS Biology

"Dynamic Properties of Network Motifs Contribute to Biological Network Organization
Robert J. Prill1, Pablo A. Iglesias1,2, Andre Levchenko1*

1 Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America, 2 Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America

Biological networks, such as those describing gene regulation, signal transduction, and neural synapses, are representations of large-scale dynamic systems. Discovery of organizing principles of biological networks can be enhanced by embracing the notion that there is a deep interplay between network structure and system dynamics. Recently, many structural characteristics of these non-random networks have been identified, but dynamical implications of the features have not been explored comprehensively. We demonstrate by exhaustive computational analysis that a dynamical property—stability or robustness to small perturbations—is highly correlated with the relative abundance of small subnetworks (network motifs) in several previously determined biological networks. We propose that robust dynamical stability is an influential property that can determine the non-random structure of biological networks.

Academic Editor: Arthur Lander, University of California, Irvine, United States of America

Received: March 22, 2005; Accepted: August 4, 2005; Published: October 4, 2005"

Microscopic artificial swimmers


"Microorganisms such as bacteria and many eukaryotic cells propel themselves with hair-like structures known as flagella, which can exhibit a variety of structures and movement patterns. For example, bacterial flagella are helically shaped and driven at their bases by a reversible rotary engine, which rotates the attached flagellum to give a motion similar to that of a corkscrew. In contrast, eukaryotic cells use flagella that resemble elastic rods4 and exhibit a beating motion: internally generated stresses give rise to a series of bends that propagate towards the tip. In contrast to this variety of swimming strategies encountered in nature, a controlled swimming motion of artificial micrometre-sized structures has not yet been realized. Here we show that a linear chain of colloidal magnetic particles linked by DNA and attached to a red blood cell can act as a flexible artificial flagellum. The filament aligns with an external uniform magnetic field and is readily actuated by oscillating a transverse field. We find that the actuation induces a beating pattern that propels the structure, and that the external fields can be adjusted to control the velocity and the direction of motion.

Laboratoire Colloïdes et Matériaux Divisés, ESPCI, UMR CNRS 7612 UPMC, ParisTech, 10 rue Vauquelin, 75005 Paris, France
Division of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
Laboratoire Physique et Mécanique des Milieux Hétérogènes, ESPCI, UMR CNRS 7636, ParisTech, 10 rue Vauquelin, 75005 Paris, France"

Nanoscale Imaging of Buried Structures via Scanning Near-Field Ultrasound Holography


{Free registration required}

"A nondestructive imaging method, scanning near-field ultrasound holography (SNFUH), has been developed that provides depth information as well as spatial resolution at the 10- to 100-nanometer scale. In SNFUH, the phase and amplitude of the scattered specimen ultrasound wave, reflected in perturbation to the surface acoustic standing wave, are mapped with a scanning probe microscopy platform to provide nanoscale-resolution images of the internal substructure of diverse materials. We have used SNFUH to image buried nanostructures, to perform subsurface metrology in microelectronic structures, and to image malaria parasites in red blood cells.

1 Institute for Nanotechnology,
2 NUANCE Center,
3 Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA."

Ulysses, fifteen years and going strong

SpaceRef - Your Space Reference

"Fifteen years after its launch, the grand ESA/NASA Ulysses space mission is still going strong, orbiting the Sun and continuing to tell exciting stories about our nearest star.
Carried into space on 6 October 1990 by the Space Shuttle Discovery, the European-built Ulysses spacecraft has already travelled an amazing seven thousand million kilometres.
During this voyage of exploration, Ulysses has literally opened new windows on the heliosphere, that vast region of space carved out by the Sun, which expands well beyond the limits of the Solar System itself."

Friday, October 07, 2005

A Reversible, Unidirectional Molecular Rotary Motor Driven by Chemical Energy


{Free registration required.}

"With the long-term goal of producing nanometer-scale machines, we describe here the unidirectional rotary motion of a synthetic molecular structure fueled by chemical conversions. The basis of the rotation is the movement of a phenyl rotor relative to a naphthyl stator about a single bond axle. The sense of rotation is governed by the choice of chemical reagents that power the motor through four chemically distinct stations. Within the stations, the rotor is held in place by structural features that limit the extent of the rotor's Brownian motion relative to the stator.

Department of Organic and Molecular Inorganic Chemistry, Stratingh Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, Netherlands."

Tuesday, October 04, 2005

NASA's Gravity Probe B Mission Completes Data Collection

SpaceRef - Your Space Reference

"Launched on April 20, 2004, from Vandenberg Air Force Base, Calif., Gravity Probe B has been using four spherical gyroscopes to precisely measure two extraordinary effects predicted by Einstein's theory. One is the geodetic effect, the amount by which the Earth warps the local space time in which it resides. The other, called frame-dragging, is the amount by which the rotating Earth drags local space time around with it."

Monday, October 03, 2005

Tenth Planet Has a Moon

SpaceRef - Your Space Reference

"The newly discovered 10th planet, 2003 UB313, is looking more and more like one of the solar system's major players. It has the heft of a real planet (latest estimates put it at about 20 percent larger than Pluto), a catchy code name (Xena, after the TV warrior princess), and a Guinness Book-ish record of its own (at about 97 astronomical units-or 9 billion miles from the sun-it is the solar system's farthest detected object). And, astronomers from the California Institute of Technology and their colleagues have now discovered, it has a moon."

Saturday, October 01, 2005

2005 AGU Fall Meeting: Session: Economic Modeling for Water Resource Management

American Geophysical Union

"Water scarcity is forcing a re-evaluation of existing water resource planning strategies in many regions. Traditional approaches to water resource development have relied on large supply projects with sufficient capacity to meet demand under all, or practically all, conditions. This leads to a considerable volume of excess capacity in all but the driest years, capacity whose building and maintenance have become increasingly expensive, in terms of both economic and environmental costs. Concerns over these issues have resulted in a sharp reduction in the number of large-scale water supply projects being developed in the United States and other industrialized nations. In the future, water demand is less likely to be met by massive infrastructure projects, and instead satisfied through the coordination of multiple smaller supplies. The focus will be on meeting peak demands while minimizing the maintenance of excess capacity through the use of more flexible alternatives (e.g., market-based transfers, portable desalination facilities), as well as more approaches involving conjunctive use of surface and groundwater. Identifying optimal strategies requires the development of stochastic risk management techniques that weigh the costs of achieving desired supply reliability levels against the economic impacts of periodic shortfalls.

This session will provide a forum for exploring the challenges and recent advances in probabilistic modeling/optimization approaches designed to maximize the benefits derived from increasingly scarce water resources. There will be a particular emphasis on the integration of stochastic hydrologic modeling techniques with the science of "decision under uncertainty", an increasingly vibrant area of economics/finance research. Developing diversified “portfolios” of supply assets facilitates more flexible approaches to water resource management, but requires an ability to manage the supply risk imposed by the greater uncertainty that accompanies dependence on multiple sources. Nonetheless, these more diversified approaches can have distinct advantages in terms of reducing supply costs and facilitating more rapidly responses to changes in hydrologic variability (i.e. climate change)."

Science & Society

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