November 10, 2006, 4:31 AM CT

From Light To Sodium Atoms

For the first time, tornado-like rotational motions have been transferred from light to atoms in a controlled way at the National Institute of Standards and Technology (NIST). The new quantum physics technique can be used to manipulate Bose-Einstein condensates (BECs), a state of matter of worldwide research interest, and possibly used in quantum information systems, an emerging computing and communications technology of potentially great power.

As reported in the Oct. 27 issue of Physical Review Letters,* the research team transferred orbital angular momentum--essentially the same motion as air molecules in a tornado or a planet revolving around a star--from laser light to sodium atoms.

The NIST experiment completes the scientific toolkit for complete control of the state of an atom, which now includes the internal, translational, and rotational behavior. The rotational motion of light previously has been used to rotate particles, but this new work marks the first time the motion has been transferred to atoms in discrete, measurable units, or quanta. Other researchers, as well as the NIST group, previously have transferred linear momentum and spin angular momentum (an internal magnetic state) from light to atoms.

The experiments were performed with more than a million sodium atoms confined in a magnetic trap. The atoms were chilled to near absolute zero and in identical quantum states, the condition known as a Bose-Einstein condensate in which they behave like a single "super-atom" with a jelly-like consistency. The BEC was illuminated from opposite sides by two laser beams, one of them with a rotating doughnut shape. Each atom absorbed one photon (the fundamental particle of light) from the doughnut laser beam and emitted one photon in the path of the other laser beam, picking up the difference in orbital angular momentum between the two photons. The interaction of the two opposing lasers created a corkscrew-like interference pattern, inducing the BEC to rotate--picture a rotating doughnut, or a vortex similar to a hurricane.........

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November 10, 2006, 4:10 AM CT

Sea Urchin Genome And Human Genome

The Sea Urchin Genome Sequencing Project (SUGSP) Consortium, led by the Human Genome Sequencing Center at Baylor College of Medicine (BCM-HGSC) in Houston, announced recently the decoding and analysis of the genome sequence of the sea urchin, Strongylocentrotus purpuratus.

The genome of a male California purple sea urchin was sequenced, and it contained over 814 million letters, spelling out 23,300 genes. Nearly 10,000 of the genes were scrutinized by an international consortium of 240 scientists from over 70 institutions in 11 countries. The high quality "draft" sequence covers over 90 percent of the genome. The primary results are presented in the Nov. 10 issue of Science, and 41 companion manuscripts describing further detailed analyses are contained in Science and a special issue of Developmental Biology appearing on Dec. 1.

The BCM-HGSC generated the sequence data for the SUGSP, then assembled the genome and led the analysis consortium. Additional resources for the project included a BAC library (clones with very large pieces of DNA) prepared at the California Institute of Technology and a physical map prepared at the Michael Smith Genome Sciences Centre at the British Columbia Cancer Agency in Vancouver.

The project was led by Drs. Erica Sodergren and George Weinstock, a husband and wife team at the BCM-HGSC, along with Dr. Richard Gibbs, director of the BCM-HGSC, and Drs. Eric Davidson and Andrew Cameron of the California Institute of Technology. The National Human Genome Research Institute of the National Institutes of Health provided most of the funding for the SUGSP.........

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November 10, 2006, 4:06 AM CT

Firefighters Face Increased Risk Of Cancers

University of Cincinnati (UC) environmental health scientists have determined that firefighters are significantly more likely to develop four different types of cancer than workers in other fields.

Their findings suggest that the protective equipment firefighters have used in the past didn't do a good job in protecting them against cancer-causing agents they encounter in their profession, the scientists say.

The scientists found, for example, that firefighters are twice as likely to develop testicular cancer and have significantly higher rates of non-Hodgkin's lymphoma and prostate cancer than non-firefighters. The scientists also confirmed prior findings that firefighters are at greater risk for multiple myeloma.

Grace LeMasters, PhD, Ash Genaidy, PhD, and James Lockey, MD, report these findings in the November edition of the Journal of Occupational and Environmental Medicine. The UC-led study is the largest comprehensive study to date investigating cancer risk linked to working as a firefighter.

"We believe there's a direct connection between the chemical exposures firefighters experience on the job and their increased risk for cancer," says LeMasters, professor of epidemiology and biostatistics at UC.

Firefighters are exposed to a number of compounds designated as carcinogens by the International Agency for Research on Cancer (IARC)--including benzene, diesel engine exhaust, chloroform, soot, styrene and formaldehyde, LeMasters explains. These substances can be inhaled or absorbed through the skin and occur both at the scene of a fire and in the firehouse, where idling diesel fire trucks produce diesel exhaust.........

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November 8, 2006, 9:30 PM CT

Blocking Gene Improves Radiation Effectiveness

Inhibiting a particular cancer-causing gene can enhance the cell-killing effects of radiation, a team of radiation oncologists and cancer biologists at the Kimmel Cancer Center at Thomas Jefferson University in Philadelphia have found.

Adam Dicker, M.D., Ph.D., professor of radiation oncology at Jefferson Medical College and his co-workers used an increasingly common animal model, the zebrafish, and antisense technology to show that the drug flavopiridol works by blocking the activity of the gene, cyclin D1, which is made in excessive amounts in about half of all breast cancers. Using similar techniques in the future, the researchers say, may enable scientists to better gauge the effects of drugs.

As per Dr. Dicker, flavopiridol was found to inhibit cyclins, a family of genes vital to cell functioning. When it was initially tested in clinical trials, it was found to be toxic in humans. But in the laboratory, it added to the cell-killing effects of ionizing radiation, which is used to treat cancer. No one was sure why.

To find out, Dr. Dicker and his group turned to zebrafish. If they understood how the drug was causing toxicity, they or someone else could potentially design molecular copycat drugs that worked just as well, but were less toxic.

"Zebrafish enabled us to add a vertebrate system to examine both efficacy and toxicity issues," he notes.........

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November 7, 2006, 11:16 PM CT

Gene Shapes Brain Region

A gene variant associated with mental illness goes hand-in-hand with enlargement of a brain region that handles negative emotions, researchers at UT Southwestern Medical Center and the Central Texas Veterans Health Care System have found.

The region of the brain called the pulvinar is larger and contains more nerve cells in humans who carry the gene.

"This might indicate that the brain regions that receive input from the pulvinar are more strongly influenced in such individuals, and the pulvinar communicates with brain regions involved in negative emotional issues," said Dr. Dwight German, professor of psychiatry at UT Southwestern and senior author of a study available online and in a future issue of Biological Psychiatry

The researchers focused on a gene related to the neurotransmitter serotonin, one of the chemical messengers that nerves use to communicate with one another. Once specific nerve cells release serotonin, a molecule called the serotonin transporter (SERT) brings it back into the cell. Thus, serotonin has only a brief influence on the target neurons. Drugs that prevent this re-uptake, such as Prozac, are frequently used to treat patients with depression.

The serotonin transporter gene has two forms, or variants: short, or SERT-s, and long, SERT-l. A person can have two copies of the short gene, one copy each of the short and long, or two copies of the long gene. It is estimated that about 17 percent of the population has two copies of the SERT-s gene.........

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November 7, 2006, 10:05 PM CT

Spectacular dinosaur skull comes back to Alberta

A "spectacular beast" is coming back to its original stomping grounds and making a new home at the University of Alberta--a coup that will allow its researchers to study the rare dinosaur skull up close.

"This is a very dramatic beast," said Dr. Michael Caldwell, a palaeontolgist who was instrumental in getting the skull to the U of A. "What we will have is a cast, but the specimen is one of a kind in the world. This is the last cast from the original mould and when you have a research quality cast where it is duplicated right down to a freckle, it doesn't get any better than that".

The fossils from this large herbivorous dinosaur were first found by the Sternberg family, who were hired by the Geological Survey of Canada to compete with Americans coming to Alberta to collect fossils. The Sternbergs gathered all kinds of bones, including the skull of Styracosaurus albertensis. "The specimen was perfect," says Caldwell. "And it's a big one--the skull is two metres long".

Styracosaurus had six long horns extending from its neck frill, a smaller horn above each of its eyes and a single horn protruding from its nose. It was a large dinosaur that could reach lengths of five metres and weigh as much as three tonnes. For almost a century, the original skull of Styracosaurus albertensis has been at the Canadian Museum of Nature in Ottawa. Now a cast of that specimen is on its way to Edmonton in a huge wooden crate on the back of a flatbed truck.........

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November 7, 2006, 5:05 AM CT

Seawater is Tomorrow's Drinking Water

Researchers at the UCLA Henry Samueli School of Engineering and Applied Science today announced they have developed a new reverse osmosis (RO) membrane that promises to reduce the cost of seawater desalination and wastewater reclamation.

Reverse osmosis desalination uses extremely high pressure to force saline or polluted waters through the pores of a semi-permeable membrane. Water molecules under pressure pass through these pores, but salt ions and other impurities cannot, resulting in highly purified water.

The new membrane, developed by civil and environmental engineering assistant professor Eric Hoek and his research team, uses a uniquely cross-linked matrix of polymers and engineered nanoparticles designed to draw in water ions but repel nearly all contaminants. These new membranes are structured at the nanoscale (the width of human hair is approximately 100,000 nanometers) to create molecular tunnels through which water flows more easily than contaminants.

Unlike the current class of commercial RO membranes, which simply filter water through a dense polymer film, Hoek's membrane contains specially synthesized nanoparticles dispersed throughout the polymer - known as a nanocomposite material.

"The nanoparticles are designed to attract water and are highly porous, soaking up water like a sponge, while repelling dissolved salts and other impurities," Hoek said. "The water-loving nanoparticles embedded in our membrane also repel organics and bacteria, which tend to clog up conventional membranes over time".........

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November 7, 2006, 4:23 AM CT

Green Plants Share Bacterial Toxin

A toxin that can make bacterial infections turn deadly is also found in higher plants, researchers at UC Davis, the Marine Biology Laboratory at Woods Hole, Mass. and the University of Nebraska have found. Lipid A, the core of endotoxin, is located in the chloroplasts, structures that carry out photosynthesis within plant cells.

The lipid A in plant cells is evidently not toxic. The human intestine contains billions of Gram-negative bacteria, but lipid A does not become a problem unless bacteria invade the bloodstream.

"We've no idea what it's doing, but it must be something important because it's been retained for a billion years of evolution of plant chloroplasts," said Peter Armstrong, professor of molecular and cellular biology at UC Davis and senior author on the paper.

Endotoxin is better known to bacteriologists and physicians as part of the outer coat of Gram-negative bacteria such as E. coli. The lipid A core of bacterial endotoxin activates the immune system and can cause septic shock, a major cause of death from infection. It is distinct from the toxin found in E. coli strain 0157, responsible for the recent outbreak of food poisoning tied to spinach.

Bacteria were thought to be the only source of lipid A. However, R.L. Pardy, professor at the University of Nebraska-Lincoln, recently found a similar molecule in Chlorella, a single-celled relative of more advanced plants. Armstrong's lab at UC Davis developed methods to visualize lipid A in cells, using a protein from the immune system of the horseshoe crab, and the researchers began collaborating.........

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November 6, 2006, 7:32 PM CT

Silent Eco-friendly Plane

MIT and Cambridge University scientists will unveil the conceptual design for a silent, environmentally friendly passenger plane at a press conference Monday, Nov. 6, at the Royal Aeronautical Society in London.

"Public concern about noise is a major constraint on expansion of aircraft operations. The 'silent aircraft' can help address this concern and thus aid in meeting the increasing passenger demand for air transport," said Edward M. Greitzer, the H.N. Slater Professor of Aeronautics and Astronautics at MIT.

Greitzer and Professor Ann P. Dowling of Cambridge University are the lead principal researchers on the Silent Aircraft Initiative. This collaboration of 40 scientists from MIT and Cambridge, plus a number of others from more than 30 companies, was launched three years ago "to develop a conceptual design for an aircraft whose noise was almost imperceptible outside the perimeter of an airfield in an urban environment".

While originally conceived to make a huge reduction in airplane noise, the team's ultimate design also has the potential to be more fuel-efficient. In a typical flight, the proposed plane, which is designed to carry 215 passengers, is predicted to achieve 124 passenger-miles per gallon, almost 25 percent more than current aircraft, as per Greitzer. (For a down-to-earth comparison, the Toyota Prius hybrid car carrying two passengers achieves 120 passenger-miles per gallon.).........

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November 6, 2006, 7:27 PM CT

Accurate Climate Change Predictions

Current climate change impact models that consider only one weather variable, such as increasing temperature, sometimes spawn unsubstantiated doomsday predictions, according to researchers at Purdue and North Carolina universities.

Climate change studies that assess the full range of interactions among temperature, radiation, precipitation and land use can better aid humans to prepare for extreme shifts in weather patterns, the scientists report in a special issue of the journal Global and Planetary Change.

Climate change impact models often don't consider whether shifting weather will allow for sustainable agriculture, said Dev Niyogi, corresponding author of the journal article and Purdue agronomy, and earth and atmospheric sciences assistant professor.

Niyogi's team looked at weather factor interactions and their impact on two different crop plants by using data for weather and field conditions that occurred in a year considered normal for the test area. By designing a study that changed a number of variables simultaneously, the researchers found that the complex interactions of precipitation with other weather factors had the most impact on the overall health of crops and regional agricultural productivity. They concluded that lack of precipitation will have the most dramatic effect on living conditions in the future.........

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