Scientific Frontline Communication Center

Emotions Key To Judging Others

SFL ORG. Educational News Network — Wed, 24 Mar 2010 16:00:00 +0000

Under Embargo Till: 16:00 UTC March 24, 2010
Posted: 16:00 UTC 03/24/2010

Emotions Key To Judging Others

Wednesday, March 24, 2010

A new study from MIT neuroscientists suggests that our ability to respond appropriately to intended harms -- that is, with outrage toward the perpetrator -- is seated in a brain region associated with regulating emotions.

Patients with damage to this brain area, known as the ventromedial prefrontal cortex (VMPC), are unable to conjure a normal emotional response to hypothetical situations in which a person tries, but fails, to kill another person. Therefore, they judge the situation based only on the outcome, and do not hold the attempted murderer morally responsible.

The finding offers a new piece to the puzzle of how the human brain constructs morality, says Liane Young, a postdoctoral associate in MIT's Department of Brain and Cognitive Sciences and lead author of a paper describing the findings in the March 25 issue of the journal Neuron.

"We're slowly chipping away at the structure of morality," says Young. "We're not the first to show that emotions matter for morality, but this is a more precise look at how emotions matter."

Working with researchers at the University of Southern California, led by Antonio Damasio, Young studied a group of nine patients with damage (caused by aneurisms or tumors) to the VMPC, a plum-sized area located a few inches behind the eyes.

Such patients have difficulty processing social emotions such as empathy or embarrassment, but "they have a perfectly intact capacity for reasoning and other cognitive functions," says Young.

The researchers gave the subjects a series of 24 hypothetical scenarios and asked for their reactions. The scenarios of most interest to the researchers were ones featuring a mismatch between the person's intention and the outcome -- either failed attempts to harm or accidental harms.

When confronted with failed attempts to harm, the patients had no problems understanding the perpetrator's intentions, but they failed to hold them morally responsible. The patients even judged attempted harms as more permissible than accidental harms (such as accidentally poisoning someone) -- a reversal of the pattern seen in normal adults.

"They can process what people are thinking and their intentions, but they just don't respond emotionally to that information," says Young. "They can read about a murder attempt and judge it as morally permissible because no harm was done."

This supports the idea that making moral judgments requires at least two processes -- a logical assessment of the intention, and an emotional reaction to it. The study also supports the theory that the emotional component is seated in the VMPC.

Young hopes to study patients who incurred damage to the VMPC when they were younger, to see if they have the same impaired judgment. She also plans to study patient reactions to situations where the harmful attempts may be directed at the patient and therefore are more personal.

Funded by the National Science Foundation, National Institute of Neurological Disorders and Stroke, National Institute on Drug Abuse, gifts from J. Epstein and S. Shuman.

Source: Massachusetts institute of Technology / Anne Trafton

Permalink: http://www.sflorg.com/comm_center/unv_science/p1013_261.html

Time Stamp: 3/24/2010 at 16:00:00 UTC

New Method to Prevent Heart Attacks

SFL ORG. Educational News Network — Wed, 17 Mar 2010 15:38:18 +0000

New Method to Prevent Heart Attacks

Wednesday, March 17, 2010

Cardiovascular disease is by far the absolute most common national disease in Sweden and a little more than 26,000 people are treated every year at hospitals due to acute cardiac infarction, according to the Heart and Lung Foundation. KTH researcher Matilda Larsson at the School of technology and health at KTH has recently defended her thesis and her research aims at developing methods which can as early as possible assess the risk of cardiovascular disease.

The earlier the risk of cardiovascular disease can be identified, the easier it will be to avoid acute cardiac infarction which will save lives. But even if research and health care has been improved considerably over the past few years, cardiovascular disease even in the future will be one of the most common reasons for sickness and mortality in Sweden. That is why Matilda Larsson's research is, to say the least, of vital importance.

"One of the problems that we face today is that the methods used for risk assessment are new, and they need to be fine-tuned. The people that use the technology that is available must have considerable experience in being able to interpret the data they receive," says Matilda Larsson.

To rectify this problem, Matilda Larsson has developed the existing ultrasound technology so that the information is more easily accessible.

"By visualising the data, the doctor will find it easier to interpret the results," says Matilda Larsson.

The usual method is that the doctor measures the heart's blood flow and how the cardiac valves operate. With the Speckle tracking method, Matilda Larsson and her colleagues study how the ultrasound image's greyscale pattern changes, and she can also measure the movement patterns and deformation of the heart and the vascular tissue.

"The long-term objective is to have access to a sensitive method which can predict myocardial infarction at an early stage," says Matilda Larsson.
Her thesis is called "Quantification and visualisation of cardiovascular function using ultrasound" and she has applied for a patent for a method used within this area.

Matilda Larsson originally comes from Ostervala between Gavle and Uppsala, but she will not be returning there for quite some time.

"Now I will continue as a post doctoral student at the university in Leuven, Belgium, where I conducted some of my thesis work. We will study movements and deformation of the carotis," says Matilda.

Image Caption: Matilda Larsson, in the background you can see her research in the form of a state of the heart diagram. This method provides a picture as to how the heart works during an entire cardiac cycle.

Image Credit: KTH Royal Institute of Technology

Source: KTH

Permalink: http://www.sflorg.com/comm_center/unv_medical/p1012_244.html

Time Stamp: 3/17/2010 at 3:12:23 PM UTC

Fruit flies and test tubes open new window on Alzheimer's disease

SFL ORG. Educational News Network — Tue, 16 Mar 2010 17:13:59 +0000

Fruit flies and test tubes open new window on Alzheimer's disease

Tuesday, March 16, 2010

A team of scientists from Cambridge and Sweden have discovered a molecule that can prevent a toxic protein involved Alzheimer's disease from building up in the brain. They found that in test tube studies the molecule not only prevents the protein from forming clumps but can also reverse this process. Then, using fruit flies with Alzheimer's disease, they showed that the same molecule effectively "cures" the insects of the disease.

Alzheimer's disease is the most common neurodegenerative disorder and is linked to the misfolding and aggregation of a small protein known as the amyloid β (Aβ) peptide. Previous studies in animal models have shown that aggregation of Aβ damages neurones (brain cells) causing memory impairment and cognitive deficits similar to those seen in patients with Alzheimer's disease. The mechanisms underlying this damage are, however, still not understood.

The new molecule - designed by scientists in Sweden - is a small protein known as an Affibody (an engineered binding protein). In this new study, researchers at the University of Cambridge and the Swedish University of Agricultural Sciences found that in test-tube experiments this protein binds to the Aβ peptide, preventing it from forming clumps and breaking up any clumps already present.

In a second experiment, they studied the effect of this Affibody in a Drosophila (fruit fly) model of Alzheimer's disease previously developed at Cambridge.

Working with fruit flies that develop the fly equivalent of Alzheimer's because they have been genetically engineered to produce the Aβ protein, they crossed these flies with a second line of flies genetically engineered to produce the Affibody.

They found that offspring - despite producing the Aβ protein - did not develop the symptoms of Alzheimer's disease.

According to lead author Dr Leila Luheshi of the Department of Genetics at University of Cambridge: "When we examined these flies we found that the Affibody not only prevented and reversed the formation of Aβ clumps, it also promoted clearance of the toxic Aβ clumps from the flies' brains."

"Finding a way of preventing these clumps from forming in the brain, and being able to get rid of them, is a promising strategy for preventing Alzheimer's disease. Affibody proteins give us a window into the Alzheimer's brain: by helping us understand how these clumps damage brain cells, they should help us unravel the Alzheimer's disease process."

According to Professor Torleif Hard of the Swedish University of Agricultural Sciences and one of the senior authors of the study: "Our work shows that protein engineering could open up new possibilities in Alzheimer's therapy development."

Source: University of Cambridge

Permalink: http://www.sflorg.com/comm_center/unv_science/p1011_260.html

Time Stamp: 3/16/2010 at 4:45:31 PM UTC

Researchers Identify Gene that May Play Role in Atherosclerosis

SFL ORG. Educational News Network — Mon, 15 Mar 2010 19:46:44 +0000

Researchers Identify Gene that May Play Role in Atherosclerosis

Monday, March 15, 2010

To understand the role of inflammation in cardiovascular and other diseases, it is essential to identify and characterize genes that induce an inflammatory response in the body -- and the genes that regulate them.

A study published online this week in the journal Proceedings of the National Academy of Sciences suggests that a gene called Hu antigen R (HuR) plays a critical role in inducing and mediating an inflammatory response in cells experiencing mechanical and chemical stresses. The study was supported by the National Institutes of Health.

The findings may open up new possibilities for developing treatments of metabolic diseases associated with inflammation, such as atherosclerosis. Atherosclerosis typically occurs in branched or curved regions of arteries where plaques form because of cholesterol build-up. Inflammation can alter the structure of plaques so that they become more likely to rupture, causing a blood vessel blockage and leading to heart attack or stroke.

"This is the first systematic study showing that HuR not only responds to external stimuli as a stress-sensitive gene, but it also regulates other stress-sensitive genes," said senior author Gang Bao, the Robert A. Milton Chair in Biomedical Engineering in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.

The study results show that HuR promotes the expression of genes that support atherosclerosis and inhibits the expression of genes that combat atherosclerosis.

"We found that suppressing expression of HuR inhibited the inflammatory response of cells, which shows that designing drugs that block HuR function may reduce the risk of plaques rupturing," explained Bao.

Bao guided Won Jong Rhee, a former postdoctoral fellow in his laboratory, to conduct a series of experiments investigating the biology, behavior and pathways of HuR.

The researchers first studied how the HuR gene responds to different flow environments and chemical treatments. They exposed human umbilical vein endothelial cells to disturbed flow -- which occurs in artery regions where plaques form -- and found that the cells expressed higher levels of HuR than when they experienced a static or laminar flow environment. This finding was validated in tissue experiments with results showing increased amounts of HuR in regions of a mouse aorta that were exposed to disturbed flow.

Then the researchers treated endothelial cells with statins, medications used to treat atherosclerosis by reducing the number of cholesterol-containing low-density lipoprotein (LDL) molecules in the blood and inhibiting inflammation. The results indicated a decreased level of HuR with statin treatment.

After establishing HuR as a stress-sensitive gene regulated by external stimuli, including flow and statin treatment, the researchers conducted experiments to determine whether HuR regulates the expression of other stress-sensitive genes. They found that reducing the level of HuR in cells increased the levels of two genes that combat atherosclerosis -- Kruppel-like factor 2 (Klf2) and endothelial nitric oxide synthase (eNOS). The reduction in HuR also decreased the expression of bone morphogenic protein-4 (BMP-4), a gene that supports atherosclerosis.

Reducing the level of HuR in cells also significantly inhibited many inflammatory responses of the endothelial cells, including the expression of two potential atherosclerosis drug targets: inter-cellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1).

Though this study showed that HuR plays a critical role in inducing and mediating an inflammatory response in cells subjected to a stressful environment, the underlying mechanism for this regulation is still not known.

"HuR protein often binds to messenger RNAs to increase their stability and translation, but we found that regulation of other stress-sensitive genes by HuR was not due to changes in mRNA stability by direct protein binding," explained Bao.

To uncover the pathways that lead to HuR's stress sensitivity, the researchers conducted a series of studies to reveal that HuR functions by adding a phosphate group to the transcriptional factor nuclear factor kappa B (NFkB) and its inhibitor IkBa. Additional research is underway to reveal what mRNAs HuR binds to and the mechanisms used to respond to mechanical and chemical stresses. Identifying the triggers for inflammation and unraveling the details of inflammatory pathways may eventually furnish new therapeutic targets.

Hanjoong Jo, the Coulter Department's Ada Lee and Pete Correll Professor in Biomedical Engineering, Kyunghwa Chang, graduate student Chih-Wen Ni and research scientist Zhilan Zheng also contributed to this research.

Image Caption: Images showing reduced levels of HuR (red) in the thoracic aorta and an area with greater curvature, compared to a region with less curvature, which is prone to atherosclerosis because endothelial cells (blue) are exposed to disturbed flow there.

Image Credit: Georgia Tech/Gang Bao

Source: Georgia Institute of Technology

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Time Stamp: 3/15/2010 at 7:23:49 PM UTC

Scientists Demonstrate Mammalian Regeneration Through a Single Gene Deletion

SFL ORG. Educational News Network — Mon, 15 Mar 2010 19:00:01 +0000

Under Embargo Till: 19:00 UTC March 15, 2010
Posted: 19:00 UTC 03/15/2010

Scientists Demonstrate Mammalian Regeneration Through a Single Gene Deletion

Monday, March 15, 2010

A quest that began over a decade ago with a chance observation has reached a milestone: the identification of a gene that may regulate regeneration in mammals. The absence of this single gene, called p21, confers a healing potential in mice long thought to have been lost through evolution and reserved for creatures like flatworms, sponges, and some species of salamander. In a report published today in the Proceedings of the National Academy of Sciences, researchers from The Wistar Institute demonstrate that mice that lack the p21 gene gain the ability to regenerate lost or damaged tissue.

Unlike typical mammals, which heal wounds by forming a scar, these mice begin by forming a blastema, a structure associated with rapid cell growth and de-differentiation as seen in amphibians. According to the Wistar researchers, the loss of p21 causes the cells of these mice to behave more like embryonic stem cells than adult mammalian cells, and their findings provide solid evidence to link tissue regeneration to the control of cell division.

"Much like a newt that has lost a limb, these mice will replace missing or damaged tissue with healthy tissue that lacks any sign of scarring," said the project's lead scientist Ellen Heber-Katz, Ph.D., a professor in Wistar's Molecular and Cellular Oncogenesis program. "While we are just beginning to understand the repercussions of these findings, perhaps, one day we'll be able to accelerate healing in humans by temporarily inactivating the p21 gene."

Heber-Katz and her colleagues used a p21 knockout mouse to help solve a mystery first encountered in 1996 regarding another mouse strain in her laboratory. MRL mice, which were being tested in an autoimmunity experiment, had holes pierced in their ears to create a commonly used life-long identification marker. A few weeks later, investigators discovered that the earholes had closed without a trace. While the experiment was ruined, it left the researchers with a new question: Was the MRL mouse a window into mammalian regeneration?

The discovery set the Heber-Katz laboratory off on two parallel paths. Working with geneticists Elizabeth Blankenhorn, Ph.D., at Drexel University, and James Cheverud, Ph.D., at Washington University, the laboratory focused on mapping the critical genes that turn MRL mice into healers.

Meanwhile, cellular studies ongoing at Wistar revealed that MRL cells behaved very differently than cells from "non-healer" mouse strains in culture. Khamilia Bedebaeva, M.D., Ph.D., having studied genetic effects following the Chernobyl reactor radiation accident, noticed immediately that these cells were atypical, showing profound differences in cell cycle characteristics and DNA damage. This led Andrew Snyder, Ph.D., to explore the DNA damage pathway and its effects on cell cycle control.

Snyder found that p21, a cell cycle regulator, was consistently inactive in cells from the MRL mouse ear. P21 expression is tightly controlled by the tumor suppressor p53, another regulator of cell division and a known factor in many forms of cancer. The ultimate experiment was to show that a mouse lacking p21 would demonstrate a regenerative response similar to that seen in the MRL mouse. And this indeed was the case. As it turned out, p21 knockout mice had already been created, were readily available, and widely used in many studies. What had not been noted was that these mice could heal their ears.

"In normal cells, p21 acts like a brake to block cell cycle progression in the event of DNA damage, preventing the cells from dividing and potentially becoming cancerous," Heber-Katz said. "In these mice without p21, we do see the expected increase in DNA damage, but surprisingly no increase in cancer has been reported."

In fact, the researchers saw an increase in apoptosis in MRL mice -- also known as programmed cell death -- the cell's self-destruct mechanism that is often switched on when DNA has been damaged. According to Heber-Katz, this is exactly the sort of behavior seen in naturally regenerative creatures.

"The combined effects of an increase in highly regenerative cells and apoptosis may allow the cells of these organisms to divide rapidly without going out of control and becoming cancerous," Heber-Katz said. "In fact, it is similar to what is seen in mammalian embryos, where p21 also happens to be inactive after DNA damage. The down regulation of p21 promotes the induced pluripotent state in mammalian cells, highlighting a correlation between stem cells, tissue regeneration, and the cell cycle."

The study was supported by grants from the Harold G. and Leila Y. Mathers Foundation, the F.M. Kirby Foundation, the W.W. Smith Foundation, the National Institute for General Medical Sciences and National Cancer Institute.

Study investigators also include Wistar researchers Paul M. Lieberman, Ph.D.; Dmitri Gourevitch M.D.; Lise Clark D.V.M., Ph.D.; Xiang-Ming Zhang; and John Leferovich. Snyder, formerly of the Lieberman laboratory at Wistar, and Bedebaeva are co-first authors on this paper. James Cheverud of Washington University is also a co-author on this paper.

The Wistar Institute is an international leader in biomedical research with special expertise in cancer research and vaccine development. Founded in 1892 as the first independent nonprofit biomedical research institute in the country, Wistar has long held the prestigious Cancer Center designation from the National Cancer Institute. The Institute works actively to ensure that research advances move from the laboratory to the clinic as quickly as possible.

Source: Wistar Institute

Permalink: http://www.sflorg.com/comm_center/science/p1009_29.html

Time Stamp: 3/15/2010 at 19:00:00 UTC

Developing Weed Resistance in Corn Hybrids

SFL ORG. Educational News Network — Mon, 15 Mar 2010 18:28:47 +0000

Developing Weed Resistance in Corn Hybrids

Monday, March 15, 2010

Millions of people in the savannas of west and central Africa rely on maize (corn) as a staple crop, and as an "insurance" food crop at the beginning of the rainy season. A destructive parasitic weed, Striga hermonthica, poses a threat to this valuable crop. Almost 64% of cropland in this area of Africa is affected by the parasite, which causes an average grain yield loss of 68%. Farmers in Striga-infested areas have not yet adopted Striga-resistant hybrids.

Scientists at the International Institute of Tropical Agriculture (IITA) in partnership with scientists in the University of Ibadan in Nigeria and the National Institute of Agricultural Research in Benin Republic investigated the relationship between the genetic diversity of maize inbred lines having different levels of resistance to Striga and the performance of their hybrids under parasite infestation. The results are reported in the March-April 2010 edition of Crop Science, published by the Crop Science Society of America.

The study experimented on all combinations of ten lines of maize with varying levels of resistance to the parasitic weeds in different locations in Africa over three years. Hybrids from two resistant parental lines exhibited the highest level of field resistance, while hybrids from parents with low resistance fared the worst. Hybrids with only one parent with high Striga resistance showed moderate levels of field resistance.

Another important finding was that the genetic diversity of the parental lines did not affect grain yield or other traits among the hybrids. The researchers expect that genetically diverse, Striga-resistant maize crops will provide opportunities to further increase the levels of field resistance to S. hermonthica through breeding.

Such Striga resistant maize hybrids may encourage farmers that abandoned farms due to severe Striga infestation to go back into maize production. This would contribute to food security and provide income-generating opportunities to farmers that depend on maize as an important food crop in Striga infested areas.

Source: Crop Science Society of America

Permalink: http://www.sflorg.com/comm_center/science/p1008_28.html

Time Stamp: 3/15/2010 at 6:12:08 PM UTC

Boeing A160T Proves Resupply Capability for US Marines

SFL ORG. Educational News Network — Mon, 15 Mar 2010 13:57:02 +0000

Boeing A160T Proves Resupply Capability for US Marines

Monday, March 15, 2010

The Boeing [NYSE: BA] A160T Hummingbird has successfully completed a cargo delivery demonstration under a U.S. Marine Corps Warfighting Laboratory contract, proving the unmanned rotorcraft's ability to resupply frontline troops in rough terrain. The Hummingbird met or exceeded all of the demonstration requirements during the tests, conducted March 9 - March 11 at the U.S. Army's Dugway Proving Ground in Utah.

Boeing showed that the A160T can deliver at least 2,500 pounds of cargo from one simulated forward-operating base to another 75 nautical miles away in well under the required six hours. The simulated mission carried 1,250-pound sling loads over two 150-nautical-mile round trips, with the A160T operating autonomously on a preprogrammed mission.

"The Hummingbird's performance was outstanding, as we had expected," said Vic Sweberg, director of Unmanned Aerial Systems for Boeing Military Aircraft. "The A160T's capabilities can fulfill our customer's near-term need for 24/7, reliable cargo resupply. It also provides unmatched flexibility to carry out a variety of other missions, including intelligence, surveillance and reconnaissance; target acquisition; direct action; and communication relay."

The A160T completed seven test flights during the demonstration, including a two-minute hover at 12,000 feet with the 1,250-pound sling load, and a nighttime delivery to a simulated forward operating base. The A160T's ability to execute extremely accurate autonomous deliveries also was demonstrated.

The A160T has a 2,500-pound payload capacity. It features a unique optimum-speed-rotor technology that significantly improves overall performance efficiency by adjusting the rotor's speed at different altitudes, gross weights and cruise speeds. The autonomous unmanned aircraft, measuring 35 feet long with a 36-foot rotor diameter, has hovered at 20,000 feet and cruised at more than 140 knots. The A160T established a world endurance record in its class in 2008 with an 18.7-hour unrefueled flight.

A unit of The Boeing Company, Boeing Defense, Space & Security is one of the world's largest defense, space and security businesses specializing in innovative and capabilities-driven customer solutions, and the world's largest and most versatile manufacturer of military aircraft. Headquartered in St. Louis, Boeing Defense, Space & Security is a $34 billion business with 68,000 employees worldwide.

Image Caption: The Boeing [NYSE: BA] A160T Hummingbird unmanned rotorcraft met or exceeded all requirements during a sling-load cargo demonstration for the U.S. Marines held March 9 - March 11 at the U.S. Army's Dugway Proving Ground in Utah. An A160T is shown here during a previous sling-load test flight in Victorville, Calif., in January.

Image Credit: The Boeing Company

Source: The Boeing Company

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Time Stamp: 3/15/2010 at 1:41:57 PM UTC

New analysis of the structure of silks explains paradox of super-strength

SFL ORG. Educational News Network — Sun, 14 Mar 2010 18:17:42 +0000

Under Embargo Till: 18:00 UTC March 14, 2010
Posted: 18:00 UTC 03/14/2010

New analysis of the structure of silks explains paradox of super-strength

Sunday, March 14, 2010

Spiders and silkworms are masters of materials science, but scientists are finally catching up. Silks are among the toughest materials known, stronger and less brittle, pound for pound, than steel. Now scientists at MIT have unraveled some of their deepest secrets in research that could lead the way to the creation of synthetic materials that duplicate, or even exceed, the extraordinary properties of natural silk.

Markus Buehler, the Esther and Harold E. Edgerton Associate Professor in MIT's Department of Civil and Environmental Engineering, and his team study fundamental properties of materials and how those materials fail. With silk, that meant using computer models that can simulate not just the structures of the molecules but exactly how they move and interact in relation to each other. The models helped the researchers determine the molecular and atomic mechanisms responsible for the material's remarkable mechanical properties.

Silk's combination of strength and ductility -- its ability to bend or stretch without breaking -- results from an unusual arrangement of atomic bonds that are inherently very weak, Buehler and his team found. Doctoral student Sinan Keten, postdoctoral associate Zhiping Xu and undergraduate student Britni Ihle are co-authors of a paper on the research to be published on March 14 in the journal Nature Materials.

Silks are made from proteins, including some that form thin, planar crystals called beta-sheets. These sheets are connected to each other through hydrogen bonds -- among the weakest types of chemical bonds, unlike, for example, the much stronger covalent bonds found in most organic molecules. Buehler's team carried out a series of atomic-level computer simulations that investigated the molecular failure mechanisms in silk. "Small yet rigid crystals showed the ability to quickly re-form their broken bonds, and as a result fail 'gracefully' -- that is, gradually rather than suddenly," graduate student Keten explains.

"In most engineered materials" -- ceramics, for instance -- "high strength comes with brittleness," Buehler says. "Once ductility is introduced, materials become weak." But not silk, which has high strength despite being built from inherently weak building blocks. It turns out that's because these building blocks -- the tiny beta-sheet crystals, as well as filaments that join them -- are arranged in a structure that resembles a tall stack of pancakes, but with the crystal structures within each pancake alternating in their orientation. This particular geometry of tiny silk nanocrystals allows hydrogen bonds to work cooperatively, reinforcing adjacent chains against external forces, which leads to the outstanding extensibility and strength of spider silk.

One surprising finding from the new work is that there is a critical dependence of the properties of silk on the exact size of these beta-sheet crystals within the fibers. When the crystal size is about three nanometers (billionths of a meter), the material has its ultra-strong and ductile characteristics. But let those crystals grow just beyond to five nanometers, and the material becomes weak and brittle.

Buehler says the work has implications far beyond just understanding silk. He notes that the findings could be applied to a broader class of biological materials, such as wood or plant fibers, and bio-inspired materials, such as novel fibers, yarns and fabrics or tissue replacement materials, to produce a variety of useful materials out of simple, commonplace elements. For example, he and his team are looking at the possibility of synthesizing materials that have a similar structure to silk, but using molecules that have inherently greater strength, such as carbon nanotubes.

The long-term impact of this research, Buehler says, will be the development of a new material design paradigm that enables the creation of highly functional materials out of abundant, inexpensive materials. This would be a departure from the current approach, where strong bonds, expensive constituents, and energy intensive processing (at high temperatures) are used to obtain high-performance materials.

Peter Fratzl, professor in the department of biomaterials in the Max Planck Institute of Colloids and Interfaces in Potsdam, Germany, who was not involved in this work, says that "strength of this team is their pioneering multi-scale theoretical approach" to analyzing natural materials. He adds that this is "the first evidence from theoretical modeling of how hydrogen bonds, as weak as they might be, can provide high strength and toughness if arranged in a suitable way within the material."

Professor of biomaterials Thomas Scheibel of the University of Bayreuth, Germany, who was also not involved in this work, says Buehler's work is of the "highest caliber," and will stimulate much further research. The MIT team's approach, he says, "will provide a basis for better understanding of certain biological phenomena so far not understood."

Funding for this work was supported by the Office of Naval Research, with additional funding from the National Science Foundation, the Army Research Office, the MIT Energy Initiative, and MIT's UROP and MISTI-Germany programs.

Source: Massachusetts institute of Technology / David Chandler

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Time Stamp: 3/14/2010 at 18:00:00 UTC

New microscopy technique offers close-up, real-time view of cellular phenomena

SFL ORG. Educational News Network — Sun, 14 Mar 2010 18:07:06 +0000

Under Embargo Till: 18:00 UTC March 14, 2010
Posted: 18:00 UTC 03/14/2010

New microscopy technique offers close-up, real-time view of cellular phenomena

Sunday, March 14, 2010

For two decades, scientists have been pursuing a potential new way to treat bacterial infections, using naturally occurring proteins known as antimicrobial peptides (AMPs). Now, MIT scientists have recorded the first microscopic images showing the deadly effects of AMPs, most of which kill by poking holes in bacterial cell membranes.

Researchers in the laboratory of MIT Professor Angela Belcher modified an existing, extremely sensitive technique known as high-speed atomic force microscopy (AFM) to allow them to image the bacteria in real time. Their method, described in this Sunday's online edition of Nature Nanotechnology, represents the first way to study living cells using high-resolution images recorded in rapid succession.

Using this type of high-speed AFM could allow scientists to study how cells respond to other drugs and to viral infection, says Belcher, the Germeshausen Professor of Materials Science and Engineering and Biological Engineering. The new work could also help researchers understand how some bacteria can become resistant to AMPs (none of which have been approved as drugs yet).

Atomic force microscopy, invented in 1986, is widely used to image nanoscale materials. Its resolution is similar to that of electron microscopy, but unlike electron microscopy, it does not require a vacuum and thus can be used with living samples. However, traditional AFM requires several minutes to produce one image, so it cannot record a sequence of rapidly occurring events.

In recent years, scientists have developed high-speed AFM techniques, but haven't optimized them for living cells. That's what the MIT team set out to do, building on the experience of lead author Georg Fantner, a postdoctoral associate in Belcher's lab who had worked on high-speed AFM at the University of California at Santa Barbara.

How they did it: Atomic force microscopy makes use of a cantilever equipped with a probe tip that "feels" the surface of a sample. Forces between the tip and the sample can be measured as the probe moves across the sample, revealing the shape of the surface. The MIT team used a cantilever about 1,000 times smaller than those normally used for AFM, which enabled them to increase the imaging speed without harming the bacteria.

With the new setup, the team was able to take images every 13 seconds over a period of several minutes. They found that AMP-induced cell death appears to be a two-step process: a short incubation period followed by a rapid "execution." They were surprised to see that the onset of the incubation period varied from 13 to 80 seconds.

"Not all of the cells started dying at the exact same time, even though they were genetically identical and were exposed to the peptide at the same time," says Roberto Barbero, a graduate student in biological engineering and an author of the paper.

In the future, Belcher hopes to use atomic force microscopy to study other cellular phenomena, including the assembly of viruses in infected cells, and the effects of traditional antibiotics on bacterial cells. The technique may also prove useful in studying mammalian cells.

Funding provided by Erwin-Schrodinger Fellowship, National Institutes of Health, Army Research Office, Austrian Research Promotion Agency.

Source: Massachusetts institute of Technology / Anne Trafton

Permalink: http://www.sflorg.com/comm_center/unv_space/p1005_258.html

Time Stamp: 3/14/2010 at 18:00:00 UTC

Gone With the Galactic Wind: 10 Years of Chandra

SFL ORG. Educational News Network — Fri, 12 Mar 2010 19:23:27 +0000

Gone With the Galactic Wind: 10 Years of Chandra

Friday, March 12, 2010

When NASA launched its Chandra X-ray observing telescope into orbit in 1999, astronomers didn't know much about the galactic winds made of wispy, multi-million-degree gas clouds that stream out from normal galaxies like our own, because they are "diffuse, gentle and unspectacular" compared to far more dramatic emanations of starbursts, recalls astronomer Q. Daniel Wang of the University of Massachusetts Amherst.

But direct observation by the Chandra orbiting telescope have changed all that and led to "the first characterization of the spatial, thermal, chemical and kinetic properties of the gas in our galaxy," Wang states. Chandra data show, among other things, that though seemingly as ephemeral as fog, the outflowing hot gas from normal galaxies exerts a very powerful feedback force on the surroundings, preventing or slowing the infall of intergalactic gas due to gravity. "This discovery is a new key to our understanding of how galaxies work, especially how they lose mass and energy, that was not possible before Chandra," he adds.

The astronomer catalogs the new knowledge in an article published this week in the early online edition of Proceedings of the National Academy of Sciences. Because his group has made extensive use of Chandra data, he was asked to write a review celebrating the instrument's 10-year anniversary.

As Wang explains, galaxies like our own are made of visible stars and gas but investigating this matter and its properties using only visible light reveals only a small fraction of material actually present. "The hot gas is very hard to detect because of its low density, hence weak radiation, compared to black holes and neutron stars that accrete from their companions, which tend to overwhelm X-ray emissions from a galaxy," he adds.

"By X-raying galaxies, we can see the invisible, and with the Chandra instrument we can detect gas that emits or absorbs X-rays, as well as such exotic objects as black holes and neutron stars that tend to emit primarily in X-rays." X-ray tomography by the high-spectral resolution Chandra instrument has given astronomers the unprecedented opportunity to examine the amount, distribution and composition of the hot gas against bright background sources.

It has also helped to yield clues to the mystery of why there is not enough hot gas present inside or in the immediate vicinity of galaxies as predicted by current theory, in particular elements synthesized and ejected by stars. In fact, says Wang, "we find that the bulk of energy expected from the supernovae is missing as well. We conclude that this missing energy is gone with the wind, a galactic wind that blows matter to much larger regions around galaxies than previously understood."

"Indeed, we find direct evidence for such winds and outflows in nearby galaxies. This uses another well-known capability of the Chandra, the exquisite spatial resolution, which allows us to detect discrete X-ray sources and to remove them cleanly when mapping X-ray emission in and around galaxies. The outflows are called galactic feedback, which can have profound impact on the ecosystem of the galaxies."

"These results, compared with detailed simulations, now enable us to study how the feedback regulates the formation and evolution of galaxies," Wang says.

Image Credit: NASA/CXC

Source: University of Massachusetts Amherst

Permalink: http://www.sflorg.com/comm_center/unv_space/p1004_42.html

Time Stamp: 3/12/2010 at 7:07:01 PM UTC

Scientist Explains Whistler Turbulence in Space

SFL ORG. Educational News Network — Fri, 12 Mar 2010 19:21:21 +0000

Scientist Explains Whistler Turbulence in Space

Friday, March 12, 2010

Gusty winds streaming off our Sun are called solar wind and this wind propagates outwardly and develops in complicated structures, i.e. turbulence, in space and time all across the interplanetary space. The behavior of the solar wind is quite unpredictable and has long been a subject of comprehensive research because it governs numerous processes that directly impacts planet Earth.

These include geomagnetic storm, hazardous cosmic particles, space weather etc. Understanding the behavior of solar wind is therefore very critical. In situ spacecraft measurements, theory and modeling are trying to find out a fundamental question; how energy from the solar wind is transferred across many different scales (like packets or eddies of various shapes and sizes) in the interplanetary space. Unfortunately, owing to its complex nature, the problem of solar wind turbulence continues to remain one of the unresolved issues in space physics.

What is remarkably complicated is the multitude of length and time scales on which turbulence is happening throughout the interplanetary space. At very high (higher than ion cyclotron) frequency, the magnetized solar wind plasma excites whistler waves (that sounds like whistles and were first discovered by World War I radio operators) whose behavior is far more complicated than ever thought. Unfortunately their dynamics is poorly understood in the context of solar wind turbulence that transfers energy from large scale down to the scales where the wind heats up the local plasma in the interplanetary space.

A new fluid model developed by Professor Dastgeer Shaikh at the Physics Department and Center for Space Plasma and Aeronomic Research at The University of Alabama in Huntsville (UAHuntsville), links turbulence in solar wind to the transfer of energy in space and might help shed light on this mysterious process.

Dr. Shaikh discovered that the transfer of energy in solar wind occurs much quicker than predicted by earlier theories and that density of these waves do not affect the manner in which energy is transferred across the small scale high frequency whistler turbulence in the solar wind plasma. "Earlier researchers have ignored the effect of density fluctuations on whistler wave turbulence and this step was very crucial for us to take in a forward direction if are to understand the solar wind turbulence," he said.

"Unfortunately we are not yet well equipped to measure the role of density fluctuations in the regime where whistler waves play a critical role in converting the solar wind energy into heat," said Dr Shaikh, who added that his work is therefore very important to test observationally by in situ measurements. "Since density does not modify the general consensus of solar wind turbulence, that follows a universal power law, we like to believe that they interact weakly with the wave magnetic field at such a high frequency," he said.

Dr. Shaikh is a leading scientist in the field of whistler and solar wind turbulence at UAHuntsville. His results agree with the spacecraft observations that measured the solar wind energy law 20 years ago. The research results of Dr. Shaikh are to appear in Monthly Notices of the Royal Astronomical Society.

Source: University of Alabama Huntsville

Permalink: http://www.sflorg.com/comm_center/unv_space/p1003_41.html

Time Stamp: 3/12/2010 at 6:48:09 PM UTC

U.S. Navy Awards Lockheed Martin $17 Million Contract For MK 41 Vertical Launching System

SFL ORG. Educational News Network — Thu, 11 Mar 2010 18:42:10 +0000

U.S. Navy Awards Lockheed Martin $17 Million Contract For MK 41 Vertical Launching System

Thursday, March 11, 2010

The U.S. Navy recently awarded Lockheed Martin [NYSE: LMT] a $17 million contract to provide engineering design services for the MK 41 Vertical Launching System (VLS) on the U.S. Navy's Ticonderoga-class cruisers and Arleigh Burke-class guided missile destroyers.

The cost-plus-fixed fee contract combines purchases for the U.S. Navy and eight Allied navies under the Foreign Military Sales program. Included in the work is missile integration, software development, integration of VLS into new ships, technical refresh, systems engineering and life cycle support for MK 41 VLS.

"The MK 41 is the most proven below-deck, multi-mission launching system in the world," said Dan Schultz, vice president and general manager of Lockheed Martin's Ship and Aviation Systems business. "Working closely with the U.S. Navy, we have led the system design team and have been delivering, modernizing and supporting the MK 41 VLS system for more than 30 years. Its capability is second to none."

The contract includes options which, if exercised, would bring the total contract value to $104 million over four years. The work will be performed at Lockheed Martin's locations in Baltimore, MD and Ventura, CA.

The multi-missile MK 41 launcher has revolutionized the way world navies think about sea-launched weapons, providing the capabilities to respond to numerous naval warfare threats including anti-air, anti-submarine, ship self-defense, land attack and ballistic missile defense. More than 12,000 MK 41 VLS missile cells have been delivered or are on order. MK VLS systems are either in service or on order by 12 navies around the world for 186 ships in 19 different classes.

Headquartered in Bethesda, Md., Lockheed Martin is a global security company that employs about 140,000 people worldwide and is principally engaged in the research, design, development, manufacture, integration and sustainment of advanced technology systems, products and services. The Corporation reported 2009 sales of $45.2 billion.

Video Credit: Lockheed Martin

Final Editing and Conversion: Scientific Frontline

Source: Lockheed Martin

Permalink: http://www.sflorg.com/comm_center/lockheed_martin/p1002_33.html

Time Stamp: 3/11/2010 at 6:25:40 PM UTC

Scavenging energy waste to turn water into hydrogen fuel

SFL ORG. Educational News Network — Thu, 11 Mar 2010 16:43:07 +0000

Scavenging energy waste to turn water into hydrogen fuel

Thursday, March 11, 2010

Materials scientists at the University of Wisconsin-Madison have designed a way to harvest small amounts of waste energy and harness them to turn water into usable hydrogen fuel.

The process is simple, efficient and recycles otherwise-wasted energy into a useable form.

"This study provides a simple and cost-effective technology for direct water splitting that may generate hydrogen fuels by scavenging energy wastes such as noise or stray vibrations from the environment," the authors write in a new paper, published March 2 in the Journal of Physical Chemistry Letters. "This new discovery may have potential implications in solving the challenging energy and environmental issues that we are facing today and in the future."

The researchers, led by UW-Madison geologist and crystal specialist Huifang Xu, grew nanocrystals of two common crystals, zinc oxide and barium titanate, and placed them in water. When pulsed with ultrasonic vibrations, the nanofibers flexed and catalyzed a chemical reaction to split the water molecules into hydrogen and oxygen.

When the fibers bend, asymmetries in their crystal structures generate positive and negative charges and create an electrical potential. This phenomenon, called the piezoelectric effect, has been well known in certain crystals for more than a century and is the driving force behind quartz clocks and other applications.

Xu and his colleagues applied the same idea to the nanocrystal fibers. "The bulk materials are brittle, but at the nanoscale they are flexible," he says, like the difference between fiberglass and a pane of glass.

Smaller fibers bend more easily than larger crystals and therefore also produce electric charges easily. So far, the researchers have achieved an impressive 18 percent efficiency with the nanocrystals, higher than most experimental energy sources.

In addition, Xu says, "because we can tune the fiber and plate sizes, we can use even small amounts of [mechanical] noise -- like a vibration or water flowing -- to bend the fibers and plates. With this kind of technology, we can scavenge energy waste and convert it into useful chemical energy."

Rather than harvest this electrical energy directly, the scientists took a novel approach and used the energy to break the chemical bonds in water and produce oxygen and hydrogen gas.

"This is a new phenomenon, converting mechanical energy directly to chemical energy," Xu says, calling it a piezoelectrochemical (PZEC) effect.

The chemical energy of hydrogen fuel is more stable than the electric charge, he explains. It is relatively easy to store and will not lose potency over time.

With the right technology, Xu envisions this method being useful for generating small amounts of power from a multitude of small sources -- for example, walking could charge a cell phone or music player and breezes could power streetlights.

"We have limited areas to collect large energy differences, like a waterfall or a big dam," he says. "But we have lots of places with small energies. If we can harvest that energy, it would be tremendous."

The new paper is co-authored by graduate student Kuang-Sheng Hong, research scientist Hiromi Konishi and mechanical engineering professor Xiaochun Li, all at UW-Madison. Xu's research is supported by grants from the UW-Madison Graduate School, National Science Foundation, NASA Astrobiology Institute and the U.S. Department of Energy.

Source: University of Wisconsin, Madison / Jill Sakai

Permalink: http://www.sflorg.com/comm_center/unv_science/p1001_257.html

Time Stamp: 3/11/2010 at 4:28:11 PM UTC

Seaweed Extract May Hold Promise for Non-Hodgkin's Lymphoma Treatment

SFL ORG. Educational News Network — Thu, 11 Mar 2010 01:30:01 +0000

Under Embargo Till: 01:30 UTC March 11, 2010
Posted: 01:30 UTC 03/11/2010

Seaweed Extract May Hold Promise for Non-Hodgkin's Lymphoma Treatment

Thursday, March 11, 2010

Seaweed extract may eventually emerge as a lymphoma treatment, according to laboratory research presented at the second AACR Dead Sea International Conference on Advances in Cancer Research.

Lymphoma is a cancer of the immune system and is classified into Hodgkin's and non-Hodgkin's types, which are then further classified into B-cell and T-cell groups.

"Some forms of B-cell lymphoma are especially resistant to standard treatment and thus new therapies are needed," said Mohammad Irhimeh, Ph.D., assistant professor of hematoncology and stem cells at the Hashemite University in Jordan. "In this study, we looked at a new treatment strategy using novel active compounds derived from a natural source of seaweed."

Seaweeds containing fucoidan, a sulfated polysaccharide similar to heparin in chemical structure, have been reported to have anti-tumor activity in mice and some cell lines.

For the current study, Irhimeh and colleagues at the University of California, Berkeley, and Royal Hobart Hospital in Australia treated lymphoma cell lines with a commercially available seaweed extract.

They found that the extract had an inhibitory effect on the growth of lymphoma cell lines, while leaving the control healthy cells intact. The researchers also noted a significant pattern of activity in the genes known to be linked with apoptosis, or cell death, in lymphoma.

Irhimeh said they would continue to study the mechanism of action for these biological effects and had a goal of conducting phase II or III clinical trials.

Source: American Association for Cancer Research

Permalink: http://www.sflorg.com/comm_center/medical/p1000_106.html

Time Stamp: Time Stamp: 3/11/2010 at 01:30:00 UTC

Years of Smoking Associated with Lower Parkinson's Risk, Not Number of Cigarettes Per Day

SFL ORG. Educational News Network — Wed, 10 Mar 2010 21:03:27 +0000

Under Embargo Till: 21:00 UTC March 10, 2010
Posted: 21:00 UTC 03/10/2010

Years of Smoking Associated with Lower Parkinson's Risk, Not Number of Cigarettes Per Day

Wednesday, March 10, 2010

Researchers have new insight into the relationship between Parkinson's disease and smoking. Several studies have shown that smokers have a lower risk of developing Parkinson's disease. A new study published in the March 10, 2010, online issue of Neurology, the medical journal of the American Academy of Neurology, shows that smoking for a greater number of years may reduce the risk of the disease, but smoking a larger number of cigarettes per day may not reduce the risk.

"These results could guide the development of studies on various tobacco components with animal models to help understand the relationship between smoking and Parkinson's disease," said study author Honglei Chen, MD, PhD, of the National Institute of Environmental Health Sciences in Research Triangle Park, N.C. "Research to reveal the underlying chemicals and mechanisms is warranted; such studies may lead to a better understanding of the causes of Parkinson's disease. However, given the many adverse consequences of smoking, no one would suggest smoking in order to prevent Parkinson's disease."

The study involved 305,468 AARP members age 50 to 71 who completed a survey on diet and lifestyle at the time and again about 10 years later. During that time, 1,662 of the people had developed Parkinson's disease, or about one-half of one percent.

Current smokers were 44 percent less likely to develop Parkinson's disease than people who had never smoked. People who had smoked in the past and quit were 22 percent less likely to develop Parkinson's than people who had never smoked.

People who smoked for 40 or more years were 46 percent less likely to develop Parkinson's disease than people who never smoked. Those who smoked for 30 to 39 years were 35 percent less likely to have the disease than nonsmokers. In contrast, those who smoked for one to nine years were only eight percent less likely to get the disease.

The risk of developing Parkinson's disease did not change based on how many cigarettes a person smoked per day.

Chen noted that studies have shown that smoking is not associated with a slower progression of the disease once Parkinson's develops or a reduced risk of death, so he said there is no evidence to support the use of nicotine or other smoking-related chemicals in treating the disease.

The study was supported by the National Institutes of Health, the National Institute of Environmental Health Sciences and the National Cancer Institute.

The American Academy of Neurology, an association of more than 22,000 neurologists and neuroscience professionals, is dedicated to promoting the highest quality patient-centered neurologic care. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as Parkinson's disease, ALS (Lou Gehrig's disease), dementia, West Nile virus, and ataxia.

Source: American Academy of Neurology

Permalink: http://www.sflorg.com/comm_center/medical/p999_105.html

Time Stamp: 3/10/2010 at 21:00:00 UTC

Engineering Team Developing Helicopter That Would Investigate Nuclear Disasters

SFL ORG. Educational News Network — Wed, 10 Mar 2010 16:59:59 +0000

Engineering Team Developing Helicopter That Would Investigate Nuclear Disasters

Wednesday, March 10, 2010

Students at Virginia Tech's Unmanned Systems Laboratory are perfecting an autonomous helicopter they hope will never be used for its intended purpose. Roughly six feet long and weighing 200 pounds, the re-engineered aircraft is designed to fly into American cities blasted by a nuclear weapon or dirty bomb.

The helicopter's main mission would be to assist military investigators in the unthinkable: Enter an American city after a nuclear attack in order to detect radiation levels, map, and photograph damage.

"It's for a worst-case scenario," said project leader Kevin Kochersberger, a research associate professor with the College of Engineering and director of the Virginia Tech Unmanned Systems Laboratory. His team consists of several graduate and undergraduate students from the mechanical engineering and electrical and computer engineering departments.

Kochersberger and his team re-engineered a remote-controlled Yamaha-built Unmanned Aerial Vehicle RMAX helicopter to fly in fully autonomous mode. They also created flight control software algorithms that will direct the helicopter to radioactive sources on its own accord. To carry out various missions, the researchers outfitted the helicopter with various "plug-and-play payloads" as the vehicle's weight capacity is limited. The payloads are easily loadable and unloadable boxes that fit snugly under the helicopter's main body, carrying devices that would detect radiation levels in the atmosphere and on the ground, and take video and still images of damage. Flight control software would allow the mission to be changed mid-flight.

One payload is unique: A miniature tray-like robot on treads that can be launched via a tether wire from the helicopter to collect evidence. The helicopter would hover over the robot, and pull it back via the wire. A student team is building this robot, which will boast not only "chunk" sampling capability, but also a miniature vacuum which could suck up dust and dirt.

The robot is expected to easily maneuver any terrain, including expected bomb craters, as part of its investigation, said Michael Rose, a graduate student in mechanical engineering, from Gilroy, Calif. The team plans to make the robot water proof, in the event that it comes across water -- busted water mains, lakes, rain puddles, etc. "The electronics must be protected from the harmful elements," Rose said.

The group also designed a downward-looking stereo camera system mounted to the helicopter, to image affected areas. The cameras would allow for computerized 3-D terrain mapping of affected areas, an absolute necessity to understand the characteristics of the blast. It is expected that the helicopter will have night vision capabilities, and enhanced imaging technologies that improve vision through smoke and fog as the project progresses, Kochersberger said.

The project, already funded at $735,000 with an additional $650,000 allocated for 2010, is overseen by the U.S. Defense Threat Reduction Agency and spearheaded by the Department of Energy's Savannah River National Laboratory. Plans call for the helicopters to be mission-ready in three years. Department of Defense personnel already have visited Blacksburg to watch a demonstration as the craft zeroed in on a small, planted radioactive source at Kentland Farm, several miles from the Virginia Tech campus. More testing is underway, with another Department of Defense demonstration planned for 2010 in Savannah, Ga.

Image Caption: Kevin Kochersberger, a research associate professor with the Virginia tech College of Engineering and director of the Virginia Tech Unmanned Systems Laboratory, and the autonomous helicopter.

Image Credit: Virginia Polytechnic Institute and State University

Source: Virginia Polytechnic Institute and State University

Permalink: http://www.sflorg.com/comm_center/aviation/p998_05.html

Time Stamp: 3/10/2010 at 4:40:40 PM UTC

Vaccinating Children For Flu May Help Prevent Transmission

SFL ORG. Educational News Network — Tue, 09 Mar 2010 21:03:36 +0000

Under Embargo Till: 21:00 UTC March 09, 2010
Posted: 21:00 UTC 03/09/2010

Vaccinating Children For Flu May Help Prevent Transmission

Tuesday, March 9, 2010

Immunizing children and adolescents with inactivated influenza vaccine resulted in reduced rates of influenza in their community compared to a similar community in which children did not receive the vaccine, suggesting that vaccinating children may help prevent transmission of the virus and offer protection for unimmunized community residents, according to a study in the March 10 issue of JAMA.

Influenza is a major cause of illness and death, resulting in an estimated 200,000 hospitalizations and 36,000 deaths annually in the United States alone. "Current vaccine policy focuses on immunizing those at high risk of complications of influenza. As a component of a broader policy to prevent the spread of influenza and reduce its complications, using immunization to interrupt community-wide transmission of influenza may be effective for protecting the entire population, including those at high risk," the authors write. They add that children and adolescents appear to play an important role in the transmission of influenza, and that selective vaccination against influenza among this group may interrupt virus transmission and protect those not vaccinated.

Mark Loeb, M.D., M.Sc., of McMaster University, Hamilton, Ontario, Canada, and colleagues assessed whether vaccinating children and adolescents with inactivated influenza vaccine could prevent influenza in other community members. Because randomizing entire communities to test the indirect benefit of vaccinating children and adolescents against influenza is not feasible in most settings, the researchers conducted their study among Hutterite (of the Anabaptist faith) colonies, which are rural communities found mostly in western Canada. "These tightly knit communities resemble extended families but are composed of single families each residing in their own house, where children and adolescents between the ages of 3 years and 15 years attend school. Approximately 60 to 120 people reside on each colony," the authors write.

This trial included 947 Canadian children and adolescents ages 3 to 15 years who received study vaccine and 2,326 community members who did not receive the study vaccine in 49 Hutterite colonies in Alberta, Saskatchewan, and Manitoba. Follow-up began in December 2008 and ended in June 2009. Children were randomly assigned according to community to receive standard dosing of either inactivated trivalent influenza vaccine or hepatitis A vaccine, which was used as a control.

The average vaccine coverage among healthy children of clusters assigned to the influenza vaccine was 83 percent, which was similar to the average vaccine coverage among colonies assigned to hepatitis A vaccine (79 percent). Laboratory-confirmed influenza was detected in 119 nonrecipients: 39 (3.1 percent) in the colonies assigned to influenza immunization and 80 (7.6 percent) in colonies assigned to hepatitis A. The level of indirect vaccine protective effectiveness was 61 percent.

Among all study participants (those who were and those who were not vaccinated), 80 of 1,773 (4.5 percent) in the influenza vaccine colonies and 159 of 1,500 (10.6 percent) in the hepatitis A vaccine colonies had confirmed influenza illness for an overall protective effectiveness of 59 percent. No serious vaccine adverse events were observed.

"Considering for instance the rapid spread of influenza A(H1N1) in the 2009 pandemic, understanding whether influenza transmission can be prevented or reduced by immunizing children is of high priority so that groups such as pregnant women and aboriginal populations who are at high risk of complications may potentially be indirectly protected," the authors write.

"Our findings offer experimental proof to support selective influenza immunization of school aged children with inactivated influenza vaccine to interrupt influenza transmission. Particularly, if there are constraints in quantity and delivery of vaccine, it may be advantageous to selectively immunize children in order to reduce community transmission of influenza."

Source: American Medical Association
Permalink: http://www.sflorg.com/comm_center/medical/p997_104.html

Time Stamp: 3/9/2010 at 21:00:00 UTC

Research Finds Shortcomings in Comparative Effectiveness Drug Research

SFL ORG. Educational News Network — Tue, 09 Mar 2010 21:02:14 +0000

Under Embargo Till: 21:00 UTC March 09, 2010
Posted: 21:00 UTC 03/09/2010

Research Finds Shortcomings in Comparative Effectiveness Drug Research

Tuesday, March 9, 2010

An analysis by researchers at the Keck School of Medicine of the University of Southern California (USC) has found that only 32 percent of medication studies published in top medical journals compare the effectiveness of existing treatments. These studies, known as comparative effectiveness studies, help doctors know which therapies work best and under what circumstances they are most effective.

More government funding, and other changes, are needed to promote comparative effectiveness studies and improve their quality, according to the study's co-authors, Michael Hochman, M.D., assistant professor of clinical medicine at the Keck School, and Danny McCormick, M.D., M.P.H, assistant professor of medicine at Harvard Medical School.

The study, "Characteristics of Published Comparative Effectiveness Studies of Medications," published in the March 10 edition of the Journal of the American Medical Association (JAMA), provides the first formal analysis of comparative effectiveness research, which is a priority issue for the Obama Administration. Last year, Congress appropriated $1.1 billion in funding for comparative effectiveness studies as part of the American Recovery and Reinvestment Act.

"Research on new therapies is, of course, critical for scientific advancement, but we also need research that examines how to use existing therapies appropriately," said Hochman, lead author of the study. "For example, which of the more than 30 blood pressure medications on the market works best and in whom? Are certain diets and exercise regimens as good as medications for controlling cholesterol? Is it safe to aim for normal blood sugar levels when treating patients with diabetes? These are questions that comparative effectiveness studies should address."

Hochman and McCormick analyzed 328 medication studies published between June 1, 2008 and Sept. 30, 2009 in six leading medical journals, of which 104 (32 percent) were comparative effectiveness studies, as defined by Hochman and McCormick's analysis. The rest either compared medications against an inactive control group (such as a placebo) or involved unapproved therapies not currently available to doctors.

The study also showed that just 11 percent of the comparative effectiveness studies compared medications with non-pharmacologic therapies (such as lifestyle changes or surgery), and fewer than a third compared different medication strategies (such as the optimal blood sugar target in patients with diabetes). The rest compared medications with each other. In addition, just 19 percent of the comparative effectiveness studies focused on safety and only 2 percent included cost-effectiveness analyses.

"Most of the comparative effectiveness studies we reviewed simply tested whether medication 'x' is better than medication 'y,' rather than addressing fundamental questions such as 'How can we use this medication more effectively? When is this medication better than surgery? Which among two effective approaches is the safest?"said McCormick, the study's senior author.

The research also showed that 87 percent of the comparative effectiveness studies received at least some funding from non-commercial organizations, such as non-profit foundations or government institutions.

"Despite the widespread belief that the pharmaceutical industry conducts most clinical research involving medications, our study shows a critical need for non-commercial funding for comparative effectiveness research," Hochman said.

Hochman and McCormick believe their results highlight the need for more government funding for comparative effectiveness research. In addition, Hochman and McCormick recommend that the U.S. Food and Drug Administration require pharmaceutical companies to compare medications with other existing treatments whenever alternative therapies for a particular condition exist. Currently, companies often win approval for their products simply by showing that they are better than a placebo.

"Many of our nation's research priorities are driven by the pharmaceutical industry," Hochman said. "The pharmaceutical industry, not surprisingly, focuses on the development of new and marketable products. But once these products win approval, we need funding for research that examines how to use these therapies in an effective, safe, and rational manner."

Source: University of Southern California
Permalink: http://www.sflorg.com/comm_center/unv_medical/p996_242.html

Time Stamp: 3/9/2010 at 21:00:00 UTC

Kidney Donors Suffer Few Ill-Effects from Life-Giving Act

SFL ORG. Educational News Network — Tue, 09 Mar 2010 21:00:01 +0000

Under Embargo Till: 21:00 UTC March 09, 2010
Posted: 21:00 UTC 03/09/2010

Kidney Donors Suffer Few Ill-Effects from Life-Giving Act

Tuesday, March 9, 2010

In a landmark study of more than 80,000 live kidney donors from across the United States, Johns Hopkins researchers have found the procedure carries very little medical risk and that, in the long term, people who donate one of their kidneys are likely to live just as long as those who have two healthy ones.

The findings, published in the March 10 issue of the Journal of the American Medical Association, confirm what doctors have long believed: Kidney donation, which saves the life of the recipient, poses little risk to the donor.

"Donating a kidney is safe," says transplant surgeon Dorry L. Segev, M.D., Ph.D., associate professor of surgery at the Johns Hopkins University School of Medicine. "Live donors start healthy and it's the highest priority of the surgeon and the entire transplant community to make sure they stay healthy. This study says we have succeeded. While there are never any guarantees with surgery, donating a kidney is safer than undergoing almost any other operation."

Segev and his colleagues looked at data from a national registry of 80,347 live kidney donors in the United States from April 1, 1994 to March 31, 2009. There were 25 deaths in the first 90 days after donation surgery over the course of those 15 years, putting the risk of surgical mortality at 3.1 per 10,000 cases. The risk was slightly higher for some subgroups that typically have higher risk from surgery -- namely, men (5.1 deaths per 10,000 cases) and African-Americans (7.6 deaths per 10,000 cases) -- but the risk in those groups was still very small.

By contrast, Segev says, the risk of surgical mortality from gallbladder removal is roughly six times higher (18 per 10,000 cases), while the risk from non-donor nephrectomy -- removing a kidney because of cancer or another medical reason -- is approximately 260 per 10,000 cases, 100 times the risk of donating a kidney.

In the analysis, the research team found the risk to kidney donors remained low even as the number of live donor kidney transplants in the United States nearly doubled over the past 15 years from 3,009 in 1994 to 5,968 in 2008. Patients with kidney failure have been relying more and more on live kidney donors who offer to give one of their kidneys to a friend or family member in need because there is a profound organ shortage in the United States, and live donor transplants tend to survive longer than those from cadavers. Thousands of people die each year while awaiting kidneys from deceased donors. The 15-year period covered by the study included a transition from mostly open-abdomen kidney removal to minimally invasive, laparoscopic kidney donation, a technique with tiny scars and shorter recovery times. At The Johns Hopkins Hospital, where the laparoscopic procedure for kidney donation was pioneered, researchers say it has made kidney donation much less onerous.

Previous studies of live donors have been done at single-transplant centers with homogenous populations. Segev's study is the first to use national data.

"Whatever happens when people donate kidneys, on average, it doesn't affect the rest of their lives -- and that has never been shown before in a study of this size and scope," he says.

Other Johns Hopkins researchers on the study include Abimereki D. Muzaale, M.D., M.P.H.; Brian S. Caffo, Ph.D., Shruti H. Mehta, Ph.D.; Andrew L. Singer, M.D., Ph.D.; and Robert A. Montgomery, M.D., Ph.D.

Source: Johns Hopkins Medicine

Permalink: http://www.sflorg.com/comm_center/unv_medical/p995_241.html

Time Stamp: 3/9/2010 at 21:00:00 UTC

Reovirus May be a Novel Approach to Prostate Cancer Treatment

SFL ORG. Educational News Network — Tue, 09 Mar 2010 18:02:33 +0000

Under Embargo Till: 18:00 UTC March 09, 2010
Posted: 18:00 UTC 03/09/2010

Reovirus May be a Novel Approach to Prostate Cancer Treatment

Tuesday, March 9, 2010

Researchers in Canada have detected a novel oncolytic viral therapy against prostate cancer with use of a virus called the reovirus, according to study results published in Cancer Research, a journal of the American Association for Cancer Research.

The respiratory, enteric, orphan virus (commonly known as reovirus) is a non-attenuated, environmental virus that has shown oncolytic potential against many types of cancer, specifically lymphoid, ovarian, breast, pancreatic and high grade glioma cancer, according to the study. This is the first time the virus has been studied against prostate cancer.

"The reovirus is a very common, ubiquitous virus that most people are exposed to. As far as we know, it doesn't cause any significant illness in humans, even though when someone is exposed to it, it manifests, at most, as a mild respiratory infection or mild diarrhea," said researcher Don Morris, M.D., Ph.D., medical oncologist in the Department of Oncology at the Tom Baker Cancer Center in Alberta, Canada.

"For the treatment of localized prostate cancer, we found that the reovirus is safe and has evidence of specific tumor vs. normal prostate cell efficacy," added Morris.

Using preclinical and clinical settings, Morris and colleagues examined the efficacy of the reovirus as an experimental therapeutic for prostate cancer in vitro and in vivo. Among the six patients who participated in the study, all had early-stage, organ-confined prostate cancer. Each patient underwent a single intralesional virus injection into a suitable prostate cancer nodule via transrectal ultrasound guidance. Three weeks later, Morris and colleagues removed the prostate as part of the patient's standard treatment for correlative science analysis.

Findings showed safety and efficacy with minimal toxicity and no viral replication in the normal parts of the prostate, according to Morris. Cancer cell death was evident in the prostate. Studies to date have suggested that the virus' side effects are relatively modest, consisting of mild, self-limiting, flu-like symptoms.

"Our results are a stepping stone into future prostate cancer clinical trials with another category of cancer therapeutics," he said.

Robert Clarke, Ph.D., D.Sc., professor of oncology at Lombardi Comprehensive Cancer Center at Georgetown University and an editorial board member of Cancer Research, agreed, stating that he believes this study is worthy of subsequent clinical trials of the reovirus as a possible way of treating some prostate cancers.

"People have known of this application of the reovirus in trials, but no one to my knowledge has conducted studies in prostate cancer," said Clarke, who was not associated with this study. "I think this is an interesting approach. There is not a lot done in oncolytics, but clearly it is an area that is getting increasing attention, and we need everything we can get our hands on to make a difference in these patients."

Funding for this research was provided by the Alberta Cancer Foundation, Oncolytics Biotech Inc. and the Prostate Cancer Research Foundation of Canada.

Source: American Association for Cancer Research

Permalink: http://www.sflorg.com/comm_center/medical/p994_103.html

Time Stamp: 3/9/2010 at 18:00:00 UTC

Obesity Linked to Poor Colon Cancer Prognosis

SFL ORG. Educational News Network — Tue, 09 Mar 2010 18:00:42 +0000

Under Embargo Till: 18:00 UTC March 09, 2010
Posted: 18:00 UTC 03/09/2010

Obesity Linked to Poor Colon Cancer Prognosis

Tuesday, March 9, 2010

Obese patients with colon cancer are at greater risk for death or recurrent disease compared to those who are within a normal weight range, according to a report in Clinical Cancer Research, a journal of the American Association for Cancer Research.

"Obesity has long been established as a risk factor for cancer, but our study in colon cancer patients shows that obesity predicts a poorer prognosis after the cancer is surgically removed," said Frank A. Sinicrope, M.D., professor of medicine and oncology at the Mayo Clinic in Rochester.

There are approximately 150,000 new cases of colon cancer diagnosed each year in the United States, and colon cancer tends to affect men and women equally, said James Abbruzzese, M.D., chairman of the Department of Gastrointestinal Medical Oncology at The University of Texas M. D. Anderson Cancer Center and an editorial board member of Clinical Cancer Research.

"More studies are now demonstrating that obesity plays a role as an independent risk factor for poorer patient prognosis that is unrelated to stroke or heart disease," said Abbruzzese.

Remarkably though, many patients remain unaware of the risk associated between obesity and cancer. Results of a recent survey from the American Institute for Cancer Research showed that only 51 percent of the participants knew about the link between obesity and cancer, compared with 94 percent who were aware of the increased cancer risk associated with tobacco use, and 87 percent who knew of the increased cancer risk associated with sun exposure.

For the current study, Sinicrope and colleagues evaluated 4,381 patients with stage II or stage III colon cancer who had received adjuvant chemotherapy in clinical trials. Of these patients, 20 percent were obese.

Obesity was significantly linked with poorer overall survival and was independent of other variables analyzed. The prognostic impact was stronger in men than in women, and men in the highest body mass index category for obesity had a 35 percent increased risk of death compared to normal weight patients. The weaker effect in women is consistent with studies that have shown a lower risk of developing colon cancer in obese women compared to obese men.

"We do not know if this is due to biology or the way we measure obesity," said Sinicrope. "Body mass index is a limited measure and there is evidence that abdominal fat may be a better predictor of colon cancer risk and perhaps prognosis in men than in women. There is also the potential influence of menopausal status and hormone replacement therapy in women."

Source: American Association for Cancer Research

Permalink: http://www.sflorg.com/comm_center/medical/p993_102.html

Time Stamp: Time Stamp: 3/9/2010 at 18:00:00 UTC

Northrop Grumman Expands Composites Manufacturing Training for Major Turkish F-35 Supplier

SFL ORG. Educational News Network — Tue, 09 Mar 2010 17:16:05 +0000

Northrop Grumman Expands Composites Manufacturing Training for Major Turkish F-35 Supplier

Tuesday, March 9, 2010

Northrop Grumman Corporation (NYSE:NOC) is adding momentum to Turkish Aerospace Industries, Inc.'s (TAI) readiness to build complete center fuselages for the F-35 Lightning II aircraft by teaching its engineers how to build the complex composite structures used in the jet.

From Jan. 18 to Feb. 12, the company conducted rigorous classroom and hands-on training at its Advanced Composites Center in El Segundo for more than a dozen engineers and manufacturing specialists from TAI. The training was the third in a planned series of classes designed to teach TAI employees, ultimately, how to build a complete F-35 center fuselage.

"To date, TAI has made great progress in learning the tools and techniques of composites manufacturing," said Mark Tucker, vice president and F-35 program manager for Northrop Grumman's Aerospace Systems sector. "The recent training helped solidify their understanding of how to successfully produce and handle the actual composite inlet ducts used in the F-35."

TAI is a second source supplier of F-35 center fuselages to Northrop Grumman, a principal member of the Lockheed Martin-led F-35 industry team. The Turkish company is slated to produce 400 center fuselages for the program beginning in the low rate initial production phases.

Guided by Northrop Grumman F-35 subject matter experts, the training engaged the TAI employees actively in the production of forward and aft inlet ducts for the jet. It included learning how to use the complex fiber placement mandrels that define the shape of the ducts; operating the machines that perform the actual fiber placement process; preparing the ducts for curing; performing post cure processing; and machining and conducting a final inspection of the completed parts.

According to Tucker, one of the parts that the TAI team helped produce -- a forward inlet duct -- will be integrated into one of the first major structural assemblies to be produced at TAI's new F-35 assembly facilities in Ankara, Turkey later this year.

For Turker Dolek, a senior member of the TAI group, the benefits of the training extended far beyond simply refining and maturing their F-35 composite manufacturing skills.

"What we are also learning from Northrop Grumman is how to handle and manage manufacturing problems," explains Dolek. "We're very impressed that the company is encouraging all of its suppliers to bring their best effort to the program. All of the Northrop Grumman employees on the program are doing their best. We're very honored to be part of this project."

The TAI training is part of Northrop Grumman's on-going commitment to help expand international participation in the F-35 program, build a reliable global supply chain, and help Lockheed Martin transition the program successfully from its current system development and demonstration phase into the LRIP and full-rate production phases.

Northrop Grumman is responsible for designing and producing the center fuselage for all three variants of the F-35. The company also designed and produces the aircraft's radar and other key avionics including electro-optical and communications subsystems; develops mission systems and mission-planning software; leads the team's development of pilot and maintenance training system courseware; and manages the team's use, support and maintenance of low-observable technologies.

Northrop Grumman Corporation is a leading global security company whose 120,000 employees provide innovative systems, products, and solutions in aerospace, electronics, information systems, shipbuilding and technical services to government and commercial customers worldwide.

Image Caption: TAI employee Muharrem Balci uses techniques learned during the manufacturing training to repair tiny imperfections in the surface of the mandrel used to produce the F-35's uniquely-shaped all-composite air inlet ducts. The mandrel comprises ten composite parts that fit together like a three-dimensional jig saw puzzle.

Image Credit: Northrop Grumman Corp.

Source: Northrop Grumman Corp.

Permalink: http://www.sflorg.com/comm_center/northrop_grumman/p992_15.html

Time Stamp: 3/9/2010 at 4:56:25 PM UTC

Boeing 'Phantom Eye' Hydrogen Powered Vehicle Takes Shape

SFL ORG. Educational News Network — Tue, 09 Mar 2010 16:23:26 +0000

Boeing 'Phantom Eye' Hydrogen Powered Vehicle Takes Shape

Tuesday, March 9, 2010

The Boeing Company [NYSE: BA] has begun to build Phantom Eye -- its first unmanned, liquid-hydrogen powered, high altitude long endurance (HALE) demonstrator aircraft.

"The essence of Phantom Eye is its propulsion system," said Darryl Davis, Boeing Phantom Works president. "After five years of technology development, we are now deploying rapid prototyping to bring together an unmanned aerial vehicle [UAV] with a breakthrough liquid-hydrogen propulsion system that will be ready to fly early next year."

Phantom Eye's entire propulsion system -- including the engine, turbo chargers and engine control system -- successfully completed an 80-hour test in an altitude chamber on March 1, clearing the way for the propulsion system and UAV to be assembled.

The twin-engine Phantom Eye demonstrator will have a 150-foot wingspan and be capable of flying for more than four days at altitudes up to 65,000 feet while carrying a payload of up to 450 pounds. Phantom Eye is designed to maintain a persistent presence in the stratosphere over a specific area, while performing missions that could include intelligence, reconnaissance, surveillance and communication. Boeing also is developing a larger HALE that will stay aloft for more than 10 days and carry payloads of more than 2,000 pounds, and building "Phantom Ray," a fighter-sized UAV that will be a flying test bed for advanced technologies.

"We believe Phantom Eye and Phantom Ray represent two areas where the unmanned aerial vehicle market is heading, and rapid prototyping is the key to getting us there," said Dave Koopersmith, Advanced Boeing Military Aircraft vice president. "These innovative demonstrators reduce technology risks and set the stage for meeting both military and commercial customers' future needs."

Phantom Eye evolved from Boeing's earlier success with the piston-powered Condor that set several records for altitude and endurance in the late 1980s. Boeing, as the Phantom Eye system designer, is working closely with Ball Aerospace, Aurora Flight Sciences, Ford Motor Co. and MAHLE Powertrain to develop the demonstrator.

Phantom Ray evolved from the X-45C program. It is scheduled to make its first flight in December.

Image Caption: The jig load assembly, model of a liquid-hydrogen engine and fuselage skins for Boeing's Phantom Eye demonstrator in St. Louis are part of the high altitude long endurance aircraft being assembled by teams in Boeing's Phantom Works division. Other work on Phantom Eye is being done in Irvine and Huntington Beach, Calif., and in Seattle.

Image Credit: The Boeing Company

Source: The Boeing Company

Permalink: http://www.sflorg.com/comm_center/boeing/p991_36.html

Time Stamp: 3/9/2010 at 4:03:38 PM UTC

Scientists Transplant Mosquito's Nose, Advance Fight Against Malaria

SFL ORG. Educational News Network — Tue, 16 Feb 2010 03:34:00 +0000

Scientists Transplant Mosquito's Nose, Advance Fight Against Malaria

Tuesday, February 16, 2010

Scientists at Vanderbilt and Yale universities have successfully transplanted most of the "nose" of the mosquito that spreads malaria into frog eggs and fruit flies and are employing these surrogates to combat the spread of the deadly and debilitating disease that afflicts 500 million people.

The research is described in two complimentary papers, one published this week in the early online edition of the Proceedings of the National Academy of Sciences and the other which appeared online Feb. 3 in the journal Nature.

The mosquito's "nose" is centered in its antennae, which are filled with nerve cells covered with special "odorant receptors" that react to different chemical compounds. The insect ORs are comparable to analogous receptors in the human nose and taste buds on the tongue.

"We've successfully expressed about 80 percent of the Anopheles mosquito's odorant receptors in frog's eggs and in the fruit fly antennae," says Laurence Zwiebel, professor of biological sciences at Vanderbilt, whose lab performed the frog egg transplantation. The fruit-fly (Drosophila melanogaster) work was done in the laboratory of John Carlson, Eugene Higgins Professor of Molecular, Cellular and Developmental Biology at Yale.

Both accomplishments are part of a five-year project supported by the Grand Challenges in Global Health Initiative funded by the Foundation for NIH through a grant from the Bill & Melinda Gates Foundation with the goal of producing novel ways to inhibit the spread of malaria. Scientists from the Wageningen University in the Netherlands, the African Insect Science for Food and Health Institute in Kenya, Ifakara Health Institute in Tanzania and the Medical Research Council Laboratories in the Gambia are also participating in the project.

Previously, scientists have used frog eggs to study the olfactory receptors of moths, honeybees and fruit flies. DNA that encodes insect receptors are injected into a frog egg and given sufficient time to produce and localize proteins. As a result, the surface of the egg is covered with the mosquito odorant receptors. An engineered egg is placed in a voltage clamp system and an odorant is dissolved in the buffer solution in which the egg is floating. If the mosquito receptors react to the compound, the electrical properties of the egg change in a measurable fashion.

"The frog egg system is relatively rapid, highly sensitive and allows us to do very precise measurements of odorant response," says Guirong Wang, a senior research associate in the Zwiebel lab who was the lead author on the PNAS study and carried out several thousand egg/odorant recordings. "However, we call this a medium throughput system because, while it is relatively quick to set up, we have to make the odorant solutions by hand, which goes relatively slowly."

By comparison, Yale's Drosophila system is a somewhat lower throughput system because it takes about three months to engineer a fruit fly with a mosquito odorant receptor in its antennae. The system, originally developed in the Carlson lab, uses mutant flies that are missing an odor receptor. Allison Carey, a graduate student in the Yale lab, systematically inserted mosquito genes into fruit flies one at a time so that a mosquito odorant receptor was expressed in place of the missing receptor. Although the method is slightly slower than the frog egg approach, it has some distinct advantages: Most notably it responds to volatilized odorants so it works with compounds that don't dissolve readily in water. It is also effective in detecting chemicals that inhibit receptors rather than exciting them.

"Both teams used the same set of 72 Anopheles odorant receptors and tested them using the same panel of 110 odorants," says Wang. The Vanderbilt team got responses from 37 of the odorant receptors in the frog eggs while testing 6,300 odorant-receptor combinations. "The results of the two systems were quite similar. There were only a few small differences."

Both studies found that most mosquito receptors are "generalists" that react to a number of different odors while a few are "specialists" that respond to a single or small number of odors. In some cases, the researchers found that a single odorant triggers several receptors while in other cases receptors are specifically tuned to unique compounds. In particular, they found 27 Anopheles receptors that respond strongly to compounds in human sweat.

"We're now screening for compounds that interact with these receptors. We call those that do BDOCs (behaviorally disruptive olfactory compounds)," Zwiebel says. "Compounds that excite some of these receptors could help lure mosquitoes into traps or repel them away from people while others that block receptor activity may help mask people. Ultimately we are looking for cocktails of multiple compounds that demonstrate activity in the field."

The project has already developed and patented a blend of BDOCs that is more attractive to mosquitoes than humans and has also identified several repellant BDOCs. It is currently in product development discussions with several private sector companies.

Image Caption: Researcher Guirong Wang sitting at the work station where he tested the response of mosquito odorant receptors injected into frog eggs.

Image Credit: Steve Green, Vanderbilt University

Source: Vanderbilt University

Permalink: http://www.sflorg.com/comm_center/unv_science/p990_256.html

Time Stamp: 2/16/2010 at 3:06:19 AM UTC

Secondary Stroke Prevention Needs Improvement

SFL ORG. Educational News Network — Tue, 16 Feb 2010 02:43:32 +0000

Secondary Stroke Prevention Needs Improvement

Tuesday, February 16, 2010

New research finds that one out of 12 people who have a stroke will likely soon have another stroke, and one out of four will likely die within one year. Researchers say the findings highlight the vital need for better secondary stroke prevention. The study is published in the February 16, 2010, issue of Neurology, the medical journal of the American Academy of Neurology.

For the study, scientists searched a state hospital discharge database and identified 10,399 people in South Carolina with an average age of 69 who had a stroke in 2002. Of the participants, 23 percent were younger than 65 years old at the time of the initial stroke. Eighteen percent went on to have a recurrent stroke within four years. The study also included the number of heart attacks or deaths within this time period.

The study found 25 percent of people who had a stroke died within one year and eight percent of people had another stroke within one year. The risk for both events rose steadily after one year. The cumulative risk at the end of four years, for example, was: 18.1 percent for recurrent stroke, 6.2 percent for heart attack, 41.3 percent for death by any cause, 26.7 percent for vascular death and 52.5 percent for combined events, any recurrent stroke, heart attack or death, whichever occurred first.

"Furthermore, the risk of recurrent stroke was between three and six times higher than the risk of heart attack at different points during the study," said author Wuwei (Wayne) Feng, MD, MS, with the Department of Neuroscience at the Medical University of South Carolina. "Our findings suggest that South Carolina and possibly other parts of the United States may have a long way to go in preventing and reducing the risk factors for recurrent strokes."

The risk of a recurrent stroke, heart attack or death was higher for African-Americans compared to Caucasians and also increased with age and number of other disorders in addition to stroke itself.

Stroke is the third leading cause of death in the United States and South Carolina had the second highest stroke death rate in the nation in 2003.

The study was supported by the South Carolina Center for Economic Excellence in Stroke and Health Sciences South Carolina.

The American Academy of Neurology, an association of more than 22,000 neurologists and neuroscience professionals, is dedicated to promoting the highest quality patient-centered neurologic care. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as multiple sclerosis, restless legs syndrome, Alzheimer's disease, narcolepsy, and stroke.

Source: American Academy of Neurology

Permalink: http://www.sflorg.com/comm_center/medical/p989_101.html

Time Stamp: 2/16/2010 at 2:09:08 AM UTC

Call for Decade of Vaccines

SFL ORG. Educational News Network — Mon, 01 Feb 2010 16:14:37 +0000

Call for Decade of Vaccines

Monday, February 1, 2010

Bill and Melinda Gates announced that their foundation will commit $10 billion over the next 10 years to help research, develop and deliver vaccines for the world's poorest countries. The Gateses said that increased investment in vaccines by governments and the private sector could help developing countries dramatically reduce child mortality by the end of the decade, and they called for others to help fill critical financing gaps in both research funding and childhood immunization programs. Bill and Melinda Gates made their announcement at the World Economic Forum's Annual Meeting, where they were joined by Julian Lob-Levyt, CEO of the GAVI Alliance.

Source: Bill & Melinda Gates Foundation

Permalink: http://www.sflorg.com/comm_center/announcements/p988_23.html

Time Stamp: 2/1/2010 at 3:52:00 PM UTC

Researchers Discover a Way to Strengthen Proteins

SFL ORG. Educational News Network — Thu, 10 Dec 2009 17:36:58 +0000

Researchers Discover a Way to Strengthen Proteins

Thursday, December 10, 2009

Proteins, which perform such vital roles in our bodies as building and maintaining tissues and regulating cellular processes, are a finicky lot. In order to work properly, they must be folded just so, yet many proteins readily collapse into useless tangles when exposed to temperatures just a few degrees above normal body temperature.

This precarious stability leaves proteins and the living beings that depend upon them on the edge of a precipice, where a single destabilizing change in a key protein can lead to disease or death. It also greatly complicates the manufacture and use of proteins in research and medicine.

Finding a way to stabilize proteins could help prevent such dire consequences, reduce the very high cost of protein drugs and perhaps also help scientists understand why proteins are often so unstable in the first place. In a paper published in the Dec. 11 issue of the journal Molecular Cell, researchers at the University of Michigan and the University of Leeds describe a new strategy for stabilizing specific proteins by directly linking their stability to the antibiotic resistance of bacteria.

"The method we developed should provide an easy way to strengthen many proteins and by doing so increase their practical utility," said James Bardwell, a Howard Hughes Medical Institute investigator and professor of molecular, cellular and developmental biology at U-M.

In the new approach, the researchers found that when a protein is inserted into the middle of an antibiotic resistance marker, bacterial antibiotic resistance becomes dependent upon how stable the inserted protein is. This enabled the scientists to easily select for stabilizing mutations in proteins by using a simple life-or-death test for bacterial growth on antibiotics. The mutations the scientists identified rendered proteins more resistant to unfolding.

"This method also has allowed us to catch a glimpse of why proteins may need to be just barely stable," said Linda Foit, the graduate student at U-M who initiated the work. "The mutations that we found to enhance the stability of our model protein are mostly in key areas related to the protein's function, suggesting that this protein may need to be flexible and therefore marginally stable in order to work. It may be that, over the course of evolution, natural selection acts to optimize, rather than maximize protein stability."

The work was conducted in the laboratories of Bardwell at U-M and Sheena Radford at the University of Leeds and spearheaded by Foit in Bardwell's lab and postdoctoral fellow Gareth Morgan in the Radford lab. In addition to these researchers, the paper's authors are U-M undergraduate students Maximilian Kern, Lenz Steimer and Anne Kathrin von Hacht and Leeds technician James Titchmarsh and senior lecturer Stuart Warriner. The research was funded in part by the Howard Hughes Medical Institute, the National Institutes of Health, the Wellcome Trust and the University of Leeds.

Source: University of Michigan

Permalink: http://www.sflorg.com/comm_center/unv_science/987_255.html

Time Stamp: 12/10/2009 at 5:15:17 PM UTC

Aussie galaxy survey to lead to "new physics"

SFL ORG. Educational News Network — Thu, 10 Dec 2009 16:56:05 +0000

Aussie galaxy survey to lead to "new physics"

Thursday, December 10, 2009

Australian astronomers have released the first set of data from the first project to look at the effects of "dark energy" halfway back in the Universe's lifetime.

Called WiggleZ ("wiggles"), the project is being done with the Anglo-Australian Telescope in NSW and is led by Professor Michael Drinkwater of UQ's School of Mathematics and Physics.

Dark Energy is an unidentified component of the Universe that is causing the expansion of the Universe to speed up.

Determining its nature is one of the key problems of physics today, and will lead to a "new understanding of physics," Professor Drinkwater said.

WiggleZ will get a handle on Dark Energy by measuring "wiggles" in the distribution of distant galaxies.

Because light takes time to travel through the Universe, looking far out is equivalent to looking back in time, and WiggleZ is observing galaxies that existed when the Universe was half its present age.

"By observing the size of the pattern at different times in the Universe's history, we can track the history of the expansion of the Universe, and thus determine the effects of Dark Energy," Professor Warrick Couch of Swinburne University, a member of the WiggleZ team, said.

The "wiggles" pattern in galaxies in today's Universe was discovered in 2004 by two teams, one of which had used the Anglo-Australian Telescope for its galaxy survey.

WiggleZ will measure the redshifts (distances) of 240,000 galaxies, allowing astronomers to create a 3D map of galaxies stretching over a thousand square degrees on the sky and look for a pattern in the way they are clustered on large scales.

These galaxies are about halfway back in the Universe's history (4 to 8 billion years ago, corresponding to redshifts of between 0.2 and 1).

WiggleZ started in 2006 and, when finished in 2010, will be the largest galaxy redshift survey made to that time in terms of the volume of space it covers at such remote distances in the universe.

More than a dozen ground-based Dark Energy projects are proposed or under way, and at least four space-based missions, each of the order of a billion dollars, are at the design concept stage.

While the exact nature of Dark Energy is still unknown, there are only a few candidates.

A favored one is the energy of empty space itself. But it could also be that Einstein's general theory of relativity, our current theory of gravity, is wrong on large scales.

Another approach to tracking the effects of Dark Energy is to look at the brightness of distant supernovae (exploding stars), and compare them with the brightness predicted for that time in the Universe's history. This is how Dark Energy was discovered in the first place.

However, there are uncertainties associated with the supernova approach related to how close in brightness all the supernovae are.

"The galaxy clustering method also has uncertainties, but completely independent ones, so the two methods provide a powerful cross-check to each other," Dr Sarah Brough, a WiggleZ team member at the Anglo-Australian Observatory in Sydney, said.

The first WiggleZ data release, of 100,000 galaxies, is published in association with a paper in Monthly Notices of the Royal Astronomical Society.

Image Caption: Time goes from top to bottom. The "bullseyes" show where there have been two sources of pressure waves in the early universe, the waves traveling outwards like the ripples on a pond. Galaxies prefer to grow at the center and edge of the bullseye. Their preferred separation is the radius of the bullseye (the scale bar).

Image Credit: Sam Moorefield, Swinburne University

Source: University of Queensland

Permalink: http://www.sflorg.com/comm_center/unv_space/p986_40.html

Time Stamp: 12/10/2009 at 4:38:37 PM UTC

Flying Dinosaur Controversy Resolved

SFL ORG. Educational News Network — Thu, 10 Dec 2009 01:16:56 +0000

Flying Dinosaur Controversy Resolved

Thursday, December 10, 2009

New research appears to have ended a scientific debate that has vexed palaeontologists for almost 100 years.

Flying reptiles called pterosaurs ruled the Earth's skies for over 130 million years and died out 65 million years ago.

The aerodynamics of the membrane stretched over the huge 12-meter wing span would have influenced the way these animals could fly, but scientists have not been able to agree on the orientation of a particular wing-bone that controlled the shape of this membrane.

Since 1914, there have been two theories on the positioning of the pteriod, a unique wing-bone at the front of the pterosaur wing. One argues that it must have been positioned sideways, while the other suggests that it pointed forwards.

Using biomechanical analysis and testing aerodynamic efficiency, new findings by researchers from the University of Bristol, UK, and University College Dublin, Ireland, suggest that the only conceivable positioning of the wing bone is a sideways orientation.

"Based on existing fossil evidence, pterosaurs are believed to have had a wing span of up to 12 meters and a weight of between 80 and 250 kilograms," says Colin Palmer from the University of Bristol and lead author on the paper.

"In our analysis we show that a forward pointing pteriod would not have been able to withstand the stresses and strains involved in the take off and flight of such a large animal."

"The structure of the pterosaur wing must have afforded a high safety margin above what was required to support flight in such a massive animal, in order to prevent against any possible breakage or damage which would be catastrophic for the animal. And a forward pointing pteriod would not afford such a safety margin," explains Palmer.

"We were working to reconstruct how these enormous reptiles flew - how they took to the air, how they landed, and how they made their living in flight," says Dr Gareth Dyke from University College Dublin, the papers co-author.

"The direction of the pteriod bone has a major impact on the aerodynamics and performance of the pterosaur wing. A sideways orientation implies a faster flyer."

"It affects the speed at which they could fly, which could tell you about the type of life they led, where they lived, and possibly even what they ate. They are the biggest animals ever take to the skies," says Dyke.

The research is published online this week in the Proceedings of The Royal Society B.

Source: University of Bristol

Permalink: http://www.sflorg.com/comm_center/unv_science/p985_254.html

Time Stamp: 12/10/2009 at 12:57:48 AM UTC

Non-Invasive Technique Blocks a Conditioned Fear in Humans

SFL ORG. Educational News Network — Wed, 09 Dec 2009 19:19:34 +0000

Non-Invasive Technique Blocks a Conditioned Fear in Humans

Wednesday, December 9, 2009

Scientists have for the first time selectively blocked a conditioned fear memory in humans with a behavioral manipulation. Participants remained free of the fear memory for at least a year. The research builds on emerging evidence from animal studies that reactivating an emotional memory opens a 6-hour window of opportunity in which a training procedure can alter it.

"Our results suggest a non-pharmacological, naturalistic approach to more effectively manage emotional memories," said Elizabeth Phelps, Ph.D., of New York University, a grantee of the National Institutes of Health's National Institute of Mental Health (NIMH).

Phelps and NIMH grantee and NYU colleague Joseph LeDoux, Ph.D., led the research team that reports on their discovery online Dec. 9, 2009 in the journal Nature.

"Inspired by basic science studies in rodents, these new findings in humans hold promise for being translated into improved therapies for the treatment of anxiety disorders, such as post-traumatic stress disorder (PTSD)," said NIMH Director Thomas R. Insel, M.D.

The results add support to the hypothesis that emotional memories are reconsolidated -- rendered vulnerable to being modified -- each time they are retrieved. That is, reactivating a memory opens what researchers call "reconsolidation window," a time-limited period when it can be changed.

"This adaptive update mechanism appears to have evolved to allow new information available at the time of retrieval to be incorporated into the brain's original representation of the memory," explained Phelps.

Earlier this year, LeDoux and colleagues exploited this potentially clinically important insight to erase a fear memory in rats. They first conditioned rats to fear a tone by pairing it with intermittent shocks. A day later, the rats were re-exposed to the tone, reactivating the fear memory. They then underwent a process to rewrite the fear, called extinction training, in which the tone was repeatedly presented without shocks.

However, the timing of this extinction training proved critical. Fear of the stimulus was erased only in rats trained within a 6-hour reconsolidation window after re-exposure to the feared tone. Fear responses returned in animals trained after the window closed, when the memory had apparently already solidified.

Normally, extinction training suppresses but does not erase the original fear memory. By first reactivating it -- sounding the tone -- just prior to extinction training, LeDoux and colleagues permanently erased the fear memory. In the new study, Phelps and colleagues similarly conditioned human participants to fear colored squares by intermittently pairing them with mild wrist shocks.

As with the rats, a day later, the memory was first reactivated by re-exposing participants to the feared squares. A measure of nervous system arousal confirmed that they experienced a fear response. Extinction training -- repeated trials of exposure to the colored squares without shocks -- followed.

Again as in the rats, a day later, the fear response was banished only in human participants who underwent the extinction training soon after the fear reactivation. Those trained after the 6-hour consolidation window remained afraid of the squares -- as did a control group that received extinction training without first experiencing reactivation of the fear memory.

In a follow-up experiment to gauge long-term effects a year later, 19 of the original participants received a potent regimen to re-instate the fear: four shocks followed by presentations of the colored squares.

Remarkably, those who had undergone extinction training within the reconsolidation window were largely spared significant effects. By contrast, those whose training had been delayed 6 hours or who hadn't experienced fear memory reactivation prior to extinction training experienced significant reinstatement of the fear response.

In a similar experiment, the researchers also confirmed that the fear memory was blocked only for the specific colored square for which fear memory was reactivated prior to extinction training. The effect did not generalize to a differently colored square associated with the shocks. This indicated that memory re-writing during reconsolidation is highly specific and that prior reactivation with the specific stimuli is critical.

"Timing may have a more important role in the control of fear than previously appreciated," Phelps suggested. "Our memory reflects our last retrieval of it rather than an exact account of the original event."

Evidence suggests that the behavioral manipulation may work through the same molecular mechanisms as experimental medications under study for quelling traumatic emotional memories.

"Using a more natural intervention that captures the adaptive purpose of reconsolidation allows a safe and easily implemented way to prevent the return of fear," suggest the investigators.

The mission of the NIMH is to transform the understanding and treatment of mental illnesses through basic and clinical research, paving the way for prevention, recovery and cure.

More Information: Anxiety Disorders

More Information: Post-Traumatic Stress Disorder (PTSD)

Source: NIH

Permalink: http://www.sflorg.com/comm_center/medical/p984_100.html

Time Stamp: 12/9/2009 at 7:01:12 PM UTC

Lockheed Martin Cryostat To Fly On NASA's Wide-Field Infrared Survey Explorer Mission

SFL ORG. Educational News Network — Wed, 09 Dec 2009 18:45:37 +0000

Lockheed Martin Cryostat To Fly On NASA's Wide-Field Infrared Survey Explorer Mission

Wednesday, December 9, 2009

NASA's Wide-Field Infrared Survey Explorer (WISE) -- scheduled for launch on Dec. 11, 2009 from Vandenberg Air Force Base, Calif. -- will scan the entire sky in infrared light, picking up the glow of hundreds of millions of objects and producing millions of images. Two Thermos-like annular tanks filled with solid hydrogen, called a dual-stage cryostat, built by the Lockheed Martin Space Systems Company [NYSE: LMT] Advanced Technology Center (ATC) in Palo Alto, will keep the mission's sensitive infrared telescope and detectors chilled to near absolute zero. Expected to last about 10 months, the solid hydrogen cryostat will cool the WISE focal plane to 7.6 Kelvin (minus 446 Fahrenheit) and the optics to 12 Kelvin (minus 438 degrees Fahrenheit).

"After years of effort, it is very satisfying to finally reach the milestone of launch," said Iran Spradley, Senior Manager of the Thermal Sciences Department at the ATC. "We look forward with anticipation to the many discoveries that WISE is sure to make, and are enormously pleased to have played a role in this very important mission."

"Being a part of the WISE mission will always be a highlight in my career," said Larry Naes, recently retired Lockheed Martin WISE cryostat program manager. "From the very beginning of the program, our colleagues at the Jet Propulsion Laboratory assembled the best of the best to implement this mission, with a singular team focus to optimize the science and produce data that will contribute greatly to our understanding of the infrared universe."

The WISE mission will build on the heritage of NASA's very successful Infrared Astronomical Satellite (IRAS) launched in 1983. WISE, however, will have hundreds of times greater sensitivity and will uncover objects never before seen, including the coolest stars and the most luminous galaxies in the universe. The vast catalogs of infrared objects generated by WISE will help answer fundamental questions about the origins of planets, stars and galaxies, and provide astronomers a treasure trove of data that will be accessed for decades.

It is near-Earth objects, both asteroids and comets with orbits that come close to crossing Earth's path that will be the closest of WISE's discoveries. It is expected that WISE will find hundreds of these, and hundreds of thousands of additional asteroids in the main asteroid belt between Mars and Jupiter. By measuring the objects' infrared light, astronomers will get the first good estimate of the size distribution of the asteroid population. This information will reveal approximately how often Earth can expect an encounter with a potentially hazardous asteroid.

WISE will orbit Earth at an altitude of 326 miles, circling pole to pole about 15 times each day. A scan mirror within the WISE instrument will stabilize the line of sight so that snapshots can be taken every 11 seconds over the entire sky. Each position on the sky will be imaged a minimum of eight times, and some areas near the poles will be imaged more than 1,000 times. About 7,500 images will be taken every day at four different infrared wavelengths.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Wide-field Infrared Survey Explorer for NASA's Science Mission Directorate. The mission's principal investigator, Edward L. (Ned) Wright, is at UCLA. The mission was competitively selected in 2002 under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory, Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp, Boulder, Colo. Science operations and data processing will take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA. The mission's education and public outreach office is based at the University of California, Berkeley.

The ATC is the research and development organization of Lockheed Martin Space Systems Company (LMSSC). LMSSC, a major operating unit of Lockheed Martin Corporation, designs and develops, tests, manufactures and operates a full spectrum of advanced-technology systems for national security and military, civil government and commercial customers. Chief products include human space flight systems; a full range of remote sensing, navigation, meteorological and communications satellites and instruments; space observatories and interplanetary spacecraft; laser radar; ballistic missiles; missile defense systems; and nanotechnology research and development.

Source: Lockheed Martin

Permalink: http://www.sflorg.com/comm_center/lockheed_martin/p983_32.html

Time Stamp: 12/9/2009 at 6:23:02 PM UTC

Boeing Successfully Completes 747-8 Freighter Engine Runs

SFL ORG. Educational News Network — Wed, 09 Dec 2009 18:06:46 +0000

Boeing Successfully Completes 747-8 Freighter Engine Runs

Wednesday, December 9, 2009

Boeing (NYSE: BA) successfully completed the first engine runs for the 747-8 Freighter. The milestone marks another step in the 747 program's steady progress in preparing for flight test.

"We are very pleased with the engines' performance during this test," said Mo Yahyavi, vice president and general manager of the 747 program. "The engines and all the systems performed as expected."

Engine runs began slightly before 10 a.m. (PST) Tuesday. During initial engine runs, the engines are started and operated at various power settings to ensure all systems perform as expected. The engine run test began with the auxiliary power system providing power to start the first of four General Electric GEnx-2B engines. The remaining three engines were started using the cross-bleed function.

Basic systems checks continued throughout the test. The engines were powered down and inspected and will be restarted following a technical review. The team completed a vibration check and monitored the shutdown logic to ensure it functioned as expected.

"This milestone is an exciting one for the GEnx-2B team and we anticipate the engines will continue the same high performance that we have experienced in our ground and flight tests," said Tom Brisken, general manager of the GEnx Program at GE Aviation.

The GEnx-2B engine is optimized for the 747-8. It helps provide customers with improved fuel efficiency, reductions in emissions and noise and a lower cost of ownership.

Image Caption: General Electric GEnx-2B engines.

Image Credit: The Boeing Company

Source: The Boeing Company

Permalink: http://www.sflorg.com/comm_center/boeing/p982_35.html

Time Stamp: 12/9/2009 at 5:45:12 PM UTC

Lockheed Martin Receives Trident II D5 Missile System Production And Support Contract

SFL ORG. Educational News Network — Wed, 09 Dec 2009 05:40:20 +0000

Lockheed Martin Receives Trident II D5 Missile System Production And Support Contract

Wednesday, December 9, 2009

The U.S. Navy is awarding Lockheed Martin (NYSE: LMT) a contract with a value not to exceed $851 million for production and deployed system support for the Trident II D5 Fleet Ballistic Missile (FBM) program for fiscal year 2010.

Under the contract, Lockheed Martin is providing D5 missile hardware production support and reentry system hardware, as well as operations and maintenance to support the readiness and reliability of missile systems deployed aboard the Navy's Trident II OHIO-class submarines. The contract also continues the D5 Life Extension effort, which updates selected electronic components to support the extended service life of the Navy's OHIO-class submarines.

"Under the leadership of the Navy's Strategic Systems Program, the Fleet Ballistic Missile program sets the standard for partnership, disciplined performance and continual improvement," said Melanie A. Sloane, vice president of Fleet Ballistic Missile programs, Lockheed Martin Space Systems Company. "We are dedicated to supporting the Navy as it continues to raise the bar on this critically important program."

First deployed in 1990, the D5 missile is currently aboard OHIO-class submarines and British VANGUARD-class submarines. Lockheed Martin completed D5 missile deliveries for the U.S. inventory objective in 2007. The three-stage, solid-propellant, inertial-guided ballistic missile can travel a nominal range of 4,000 nautical miles and carries multiple independently targeted reentry vehicles.

Lockheed Martin Space Systems Company, Sunnyvale, Calif., is the prime contractor and program manager for the U.S. Navy's Trident missile. Approximately 2,400 Lockheed Martin Space Systems employees, principally in California, Georgia, Florida, Washington, Utah and Virginia, support the design, development, production, test and operation of the Trident Strategic Weapon System. Lockheed Martin Space Systems has been the Navy's prime strategic missile contractor since the inception of the program more than 50 years ago.

Source: Lockheed Martin

Permalink: http://www.sflorg.com/comm_center/lockheed_martin/p981_31.html

Time Stamp: 12/9/2009 at 5:27:15 AM UTC

H1N1 Influenza Adopted Novel Strategy to Move from Birds to Humans

SFL ORG. Educational News Network — Wed, 09 Dec 2009 05:10:15 +0000

H1N1 Influenza Adopted Novel Strategy to Move from Birds to Humans

Wednesday, December 9, 2009

The 2009 H1N1 influenza virus used a new strategy to cross from birds into humans, a warning that it has more than one trick up its sleeve to jump the species barrier and become virulent.

In a report in this week's early online edition of the journal Proceedings of the National Academy of Sciences, University of California, Berkeley, researchers show that the H1N1, or swine flu, virus adopted a new mutation in one of its genes distinct from the mutations found in previous flu viruses, including those responsible for the Spanish influenza pandemic of 1918, the "Asian" flu pandemic in 1957 and the "Hong Kong" pandemic of 1968.

Previous influenza strains that crossed from birds into people had a specific point mutation in the bird virus's polymerase gene that allowed the protein to operate efficiently inside humans as well. The polymerase transcribes the virus's RNA, allowing the host to express viral genes, and also copies the viral genome, needed to make new viruses.

The 2009 H1N1 virus retains the bird version of the polymerase, but has a second mutation that seems to suppress the ability of human cells to prevent the bird polymerase from working.

"We were quite shocked when we looked at the swine flu virus, which was clearly replicating in people and other mammalian systems, yet had a polymerase that looked like it was derived from a bird virus, which should not function too well in a human cell type," said UC Berkeley post-doctoral fellow Andrew Mehle of the Department of Molecular and Cell Biology. "The other mutation within the polymerase seems to compensate and allow the enzyme to function."

The researchers also discovered another strategy -- one not yet adopted by any known flu virus -- by which influenza virus can increase its virulence even more. When a particular human subunit is substituted for one of the three protein subunits that make up the bird polymerase, the new combination makes the polymerase more efficient in human cells.

"This is an extremely rare mutation and a rare combination, which suggests that there may be other ways that haven't emerged yet that these viruses are going to continue to evolve," said Jennifer Doudna, UC Berkeley professor of molecular and cell biology and an investigator in the Howard Hughes Medical Institute.

"As mechanistic biologists, we are hoping that by understanding how the virus works at the molecular level, we will be able to predict with more accuracy how it will evolve."

She suggested that those monitoring influenza outbreaks around the world in search of new variants be on the lookout for this recombination of polymerase subunits, which could herald an uptick in swine flu virulence. The findings also could help scientists develop better antiviral treatments, Mehle and Doudna said.

"The more we can understand the biochemistry and the particular structure of these polymerase complexes, the better we can make rational decisions about drug development," Mehle said.

H1N1, which appeared on the scene earlier this year, was dubbed swine flu because it emerged from pigs, in which human, bird and pig influenza viruses mixed, swapped genes and gave rise to a variant that could infect human cells and reproduce.

While mutations in the surface protein hemagglutinin -- indicated by the H in H1N1 -- are key to allowing the virus to enter human cells, mutations in the polymerase enzyme are key to the virus's ability to replicate inside human cells. All previous flu strains that entered and were transmitted in humans had a single mutation in the second subunit of the bird polymerase gene, which apparently allowed the enzyme to operate in human cells.

Last year, Mehle and Doudna showed that human cells apparently prevent the three subunits of bird virus polymerases from assembling into a functioning enzyme. A single amino acid switch at position 627 on the second subunit of the polymerase overcomes that inhibition and allows the virus to replicate. Apparently, Mehle said, when the amino acid glutamic acid -- typical of most bird virus polymerases -- is changed to a lysine, typical of human polymerases, the surface charge of the subunit changes from acidic (negatively charged) to basic (positively charged) and allows assembly of the subunits. Previous studies in mammals have shown that a lysine in that position enhances polymerase activity, increases viral replication and transmission, and in some cases, is associated with increased pathogenicity and death.

In their new study, Mehle and Doudna found that H1N1 has two rare mutations in the second subunit: a serine at position 590 and an arginine at position 591. This combination, which is most common in pigs, apparently has the same effect on surface charge as the mutation at position 627, allowing the polymerase complex to form and function in human cells.

Mehle noted that, in addition to such point mutations, flu viruses also mix and match the three subunits. Both the 1957 and 1968 viruses had polymerases composed of a first subunit from a bird and the other two subunits from humans. H1N1 has a human-like first subunit, while the second and third are bird-like -- hence the need for a mutation in the second subunit to make it more human-like.

To see which other combinations might make H1N1 more virulent, they mixed human, avian and pig subunits in culture, replicating the pig "mixing vessel," Mehle said. Several combinations with a human third subunit increased the activity of the polymerase enzyme when other mutations were not present in the second subunit. Viruses with this alteration are now being tested in human cell culture to see if they are more virulent.

"In addition to having individual amino acid changes affecting the ability of the virus to transmit across species and be more pathogenic, we need to think about these entire gene segments being exchanged back and forth," said Doudna, who also is a faculty affiliate of the California Institute for Quantitative Biosciences (QB3). "Those will affect the outcome of disease."

"We are very hopeful that the kind of basic science that we are doing here will have an impact on human health, either at the level of diagnostics or thinking forward to development of antiviral therapeutics," she added.

Mehle and Doudna continue to explore the polymerase to discover what in human cells prevents the assembly of the bird polymerase, and to determine the three-dimensional structure of the enzyme and its three subunits.

The work was supported by the National Institute of General Medical Sciences of the National Institutes of Health.

Image Caption: The sequence of the three subunits of the influenza virus polymerase (center) determines whether or not the enzyme works efficiently in birds, pigs or humans. A mutation in the PB2 subunit allows the bird virus to function in humans, as does switching out the bird PA subunit for a human PA subunit. Two mutations in the PB2 subunit of 2009 H1N1 allow the pig virus to work in humans. The background is a false-color electron micrograph image of influenza virions.

Image Credit: Andrew Mehle / University of California, Berkeley

Source: University of California, Berkeley

Permalink: http://www.sflorg.com/comm_center/unv_science/p980_253.html

Time Stamp: 12/9/2009 at 4:46:00 AM UTC

Umbilical Stem Cells May Help Recover Lost Vision for Those With Corneal Disease

SFL ORG. Educational News Network — Tue, 08 Dec 2009 18:54:07 +0000

Umbilical Stem Cells May Help Recover Lost Vision for Those With Corneal Disease

Tuesday, December 8, 2009

New research from the University of Cincinnati may help in the recovery of lost vision for patients with corneal scarring.

Winston Whei-Yang Kao, PhD, professor of ophthalmology, along with other researchers in UC's ophthalmology department found that transplanting human umbilical mesenchymal stem cells into mouse models that lack the protein lumican restored the transparency of cloudy and thin corneas.

Mesenchymal stem cells are "multi-potent" stem cells that can differentiate into a variety of cell types.

These findings are being presented Dec. 8 in San Diego at the 49th Annual Meeting of the American Society of Cell Biology.

"Corneal transplantation is currently the only true cure for restoration of eyesight that may have been lost due to corneal scarring caused by infection, mechanical and chemical wounds and congenital defects of genetic mutations," Kao says. "However, the number of donated corneas suitable for transplantation is decreasing as the number of individuals receiving refractive surgeries, like LASIK, increases."

"Worldwide, there is a shortage of suitable corneas for transplantation, and at the present time, there is no effective alternative procedure besides corneal transplantation to treat corneal blindness," he continues. "There is a large need to develop alternative treatment regimens, one of which may be the transplantation of mesenchymal stem cells."

Researchers used mouse models that did not have the lumican gene, also known as lumican knock-out models. Lumican is a protein that controls the formation and maintenance of transparent corneas.

"Lumican knock-out models manifested thin and cloudy corneas," he says. "Transplantation of the umbilical stem cells significantly improved transparency and increased corneal stromal thickness in these mice."

In addition, Kao says, the umbilical mesenchymal stem cells survived in the mouse stroma (connective tissue) for more than three months with minimal or no rejection and became corneal cells, repairing lost functions caused by mutations.

"Our results suggest a potential treatment regimen for congenital and/or acquired corneal diseases," he says, adding that the availability of human umbilical stem cells is almost unlimited. "These stem cells are easy to isolate and can be recovered quickly from storage when treating patients.

"These findings have the potential to create new and better treatments -- and an improved quality of life -- for patients with vision loss due to corneal injury."

This study was funded by grants from the National Eye Institute, Research to Prevent Blindness and the Ohio Lions Eye Research Foundation.

Image Caption: Winston Whei-Yang Kao, PhD

Image Credit: University of Cincinnati

Source: University of Cincinnati

Permalink: http://www.sflorg.com/comm_center/unv_medical/p979_240.html

Time Stamp: 12/8/2009 at 6:36:47 PM UTC

New molecule identified in DNA damage response

SFL ORG. Educational News Network — Tue, 08 Dec 2009 17:43:21 +0000

New molecule identified in DNA damage response

Tuesday, December 8, 2009

In the harsh judgment of natural selection, the ultimate measure of success is reproduction. So it's no surprise that life spends lavish resources on this feat, whether in the courtship behavior of birds and bees or replicating the cells that keep them alive. Now research has identified a new piece in an elaborate system to help guarantee fidelity in the reproduction of cells, preventing potentially lethal mutations in the process.

In experiments to be published in the December 18 issue of the Journal of Biological Chemistry, researchers at The Rockefeller University identified the molecule SMARCAL1 as part of cells' damage control response to malfunctioning

DNA replication. In typical cell division, many different molecules have roles in guaranteeing the daughter strands of DNA are as identical as possible to their parent. Some molecules check for errors or 'proofread' the offspring for typos, for instance; others, when alerted to a problem, arrest the replication process and conduct repairs.

Lisa Postow, a postdoctoral fellow in Hironori Funabiki's Laboratory of Chromosome and Cell Biology, used mass spectroscopy to identify SMARCAL1 as involved in this intricate quality control process. Working with Brian T. Chait's Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, Postow found the protein in a proteomics screen for molecules that were drawn to a dangerous DNA repair problem called a double-strand break.

In both human cells and in cells from African clawed frog egg extract, Postow found that at double-strand breaks, SMARCAL1 gathered with another molecule called RPA, which is known to coat broken strands of DNA and protect them while damage is repaired. SMARCAL1 had an added interest, too: A mutation in the gene that produces it is involved in a rare but lethal disease called Schimke immuno-osseous dysplasia, a disorder that causes wide-ranging problems including kidney malfunction, immunodeficiency and growth inhibition.

To Postow's surprise, she found that removing SMARCAL1 had little effect on double-strand break repair. However, it did facilitate a different aspect of the DNA damage response called replication fork stabilization, a process that holds steady the junction between parental and daughter strands -- the replication fork -- when replication is stalled because a problem has been detected. "For a mutation that causes such wide-ranging and severe physiological effects, it is surprising that the protein has such a relatively small effect at the cellular level," Postow says.

Postow's findings were largely corroborated by independent new research into SMARCAL1, which was published this fall in four back-to-back papers in Genes & Development. The work reveals another piece of the complex safeguards the body has in place to protect against dangerous mutations.

"This study also proves that the proteomic approach that Lisa has developed with Dr. Chait can efficiently identify proteins involving the DNA-damage recognition and repair process," says Funabiki. "Many more excitements are ahead of us."

Image Caption: Researchers have identified the molecule SMARCAL1 as involved in cells' elaborate system for recognizing and repairing DNA damage during cell division. The protein is pictured above (green) in the presence of DNA (blue) as the chromosomes align along the mitotic spindle (red).

Image Credit: Rockefeller University

Source: Rockefeller University

Permalink: http://www.sflorg.com/comm_center/unv_science/p978_252.html

Time Stamp: 12/8/2009 at 5:25:08 PM UTC

Life on Mars theory boosted by new methane study

SFL ORG. Educational News Network — Tue, 08 Dec 2009 15:43:08 +0000

Life on Mars theory boosted by new methane study

Tuesday, December 8, 2009

Scientists have ruled out the possibility that methane is delivered to Mars by meteorites, raising fresh hopes that the gas might be generated by life on the red planet, in research published tomorrow (Wednesday 9 December 2009) in Earth and Planetary Science Letters.

Methane has a short lifetime of just a few hundred years on Mars because it is constantly being depleted by a chemical reaction in the planet's atmosphere, caused by sunlight. Scientists analyzing data from telescopic observations and unmanned space missions have discovered that methane on Mars is being constantly replenished by an unknown source and they are keen to uncover how the levels of methane are being topped up.

Researchers had thought that meteorites might be responsible for Martian methane levels because when the rocks enter the planet's atmosphere they are subjected to intense heat, causing a chemical reaction that releases methane and other gases into the atmosphere.

However, the new study, by researchers from Imperial College London, shows that the volumes of methane that could be released by the meteorites entering Mars' atmosphere are too low to maintain the current atmospheric levels of methane. Previous studies have also ruled out the possibility that the methane is delivered through volcanic activity.

This leaves only two plausible theories to explain the gas's presence, according to the researchers behind today's findings. Either there are microorganisms living in the Martian soil that are producing methane gas as a by-product of their metabolic processes, or methane is being produced as a by-product of reactions between volcanic rock and water.

Co-author of the study, Dr Richard Court, Department of Earth Science and Engineering at Imperial College London, says:

"Our experiments are helping to solve the mystery of methane on Mars. Meteorites vaporising in the atmosphere are a proposed methane source but when we recreate their fiery entry in the laboratory we get only small amounts of the gas. For Mars, meteorites fail the methane test."

The team say their study will help NASA and ESA scientists who are planning a joint mission to the red planet in 2018 to search for the source of methane. The researchers say now that they have discovered that meteorites are not a source of Methane on Mars, ESA and NASA scientists can focus their attention on the two last remaining options.

Co-author, Professor Mark Sephton, Department of Earth Science and Engineering at Imperial College London, adds:

"This work is a big step forward. As Sherlock Holmes said, eliminate all other factors and the one that remains must be the truth. The list of possible sources of methane gas is getting smaller and excitingly, extraterrestrial life still remains an option. Ultimately the final test may have to be on Mars."

The team used a technique called Quantitative Pyrolysis-Fourier Transform Infrared Spectroscopy to reproduce the same searing conditions experienced by meteorites as they enter the Martian atmosphere. The team heated the meteorite fragments to 1000 degrees Celsius and measured the gases that were released using an infrared beam.

When quantities of gas released by the laboratory experiments were combined with published calculations of meteorite in-fall rates on Mars, the scientists calculated that only 10 kilograms of meteorite methane was produced each year, far below the 100 to 300 tonnes required to replenish methane levels in the Martian atmosphere.

This research was funded by a grant from the Science Technology Facilities Council.

Source: Imperial College London
Permalink: http://www.sflorg.com/comm_center/unv_space/p977_39.html
Time Stamp: 12/8/2009 at 3:30:54 PM UTC

HIV-Related Memory Loss Linked to Alzheimer's Protein

SFL ORG. Educational News Network — Mon, 07 Dec 2009 20:59:24 +0000

Under Embargo Till: 21:00 UTC December 07, 2009
Posted: 21:00 UTC 12/07/2009

HIV-Related Memory Loss Linked to Alzheimer's Protein

Monday, December 7, 2009

More than half of HIV patients experience memory problems and other cognitive impairments as they age, and doctors know little about the underlying causes. New research from Washington University School of Medicine in St. Louis suggests HIV-related cognitive deficits share a common link with Alzheimer's-related dementia: low levels of the protein amyloid beta in the spinal fluid.

However, by analyzing biomarkers in the fluid surrounding the brain and spinal cord, the researchers report Dec. 8 in the journal Neurology, they could distinguish patients with HIV-related cognitive impairments from patients with mild Alzheimer's disease. This is important because as patients with HIV age, some will develop cognitive deficits related to HIV and others to Alzheimer's. New treatments in the pipeline to improve memory and thinking may not work for both conditions.

"HIV patients with cognitive dysfunction don't have early Alzheimer's - although some of the symptoms may be similar," says lead author David Clifford, M.D., an authority on the neurological complications of HIV and director of Washington University's AIDS Clinical Trials Unit. "The underlying biology of both conditions may be related to amyloid, and we think this clue can help us find the cause of cognitive impairment in HIV patients.

Cognitive dysfunction is a major problem among the estimated 1 million Americans living with HIV. The impairments are often mild but can affect a person's daily life, relationships and ability to hold a job. They include difficulties with memory, processing complex information and making decisions. These problems are expected to worsen as HIV patients live longer, due to potent drug cocktails that keep the virus in check.

In the new research, the scientists looked at the spinal fluid of 49 HIV patients with cognitive impairments, 21 HIV patients with normal cognitive function, 68 patients with mild Alzheimer's and 50 normal, healthy "controls." The Alzheimer's patients were older (average age 74) than the controls (average age 50), impaired HIV patients (average age 48) and cognitively normal HIV patients (average age 43).

They tested the spinal fluid for the presence of amyloid beta - the protein that folds and accumulates in the brains of Alzheimer's patients and is thought to play a key role in driving the brain damage that characterizes the disease. They also looked at other biomarkers associated with Alzheimer's, including tau, a protein found in tangled nerve fibers in Alzheimer's patients.

When amyloid beta accumulates in the brains of Alzheimer's patients, levels decrease in the spinal fluid, and Clifford and his colleagues expected to find low levels of the protein in samples of the Alzheimer's patients they studied.

But they were surprised to find the same low levels in the spinal fluid of HIV patients with cognitive dysfunction. Both groups of patients had significantly lower amyloid beta levels than HIV patients without cognitive impairments and the normal controls. The lower levels are an indicator that amyloid beta in the brain alters the normal turnover of the protein in the body.

Although Australian and European researchers had uncovered a link between HIV-related cognitive deficits and amyloid beta in 2005 in a smaller study, Clifford thought that finding was an artifact and embarked on the current study largely to disprove it.

"I really did not expect the biology of HIV cognitive dysfunction to be related to Alzheimer's," Clifford says. "If you look at the brains of HIV patients with cognitive impairments, they don't look like Alzheimer's brains - they don't have the same atrophy or a plethora of plaques and tangles characteristic of Alzheimer's."

But low amyloid beta is where the similarity to Alzheimer's disease ends. The researchers found that patients with mild Alzheimer's had significantly higher levels of tau than either group of HIV patients or normal controls - a finding that strongly suggests Alzheimer's and HIV cognitive dysfunction are not one and the same, Clifford says.

He suspects the HIV-related cognitive impairment may be due to low levels of the virus that hide out in the brain, beyond the reach of drugs that can't easily cross the blood-brain barrier. Another cause may be low-grade inflammation in the brain that is driven by the virus.

Almost all HIV patients in the study were taking anti-retroviral therapy. "I am almost certain the dementia in AIDS patients is linked to HIV and not to anti-retroviral drugs - we see it even in patients who haven't received HIV therapy," Clifford says. "However, the more subtle impairment may be in some way associated with a change in the way the body processes amyloid beta. This will certainly be an important area of future research."

The research is funded by grants from the National Institutes of Health.

Clifford DB, Fagan AM, Holtzman DM, Morris JC, Teshome M, Shah AR, Kauwe JSK. CSF biomarkers of Alzheimer disease in HIV-associated neurologic disease. Neurology. Dec. 8, 2009.

Source: Washington University in St. Louis

Permalink: http://www.sflorg.com/comm_center/unv_medical/p976_239.html

Time Stamp: 12/7/2009 at 21:00:00 UTC

Isolation, Stress May Contribute to Breast Cancer Risk

SFL ORG. Educational News Network — Mon, 07 Dec 2009 20:29:45 +0000

Isolation, Stress May Contribute to Breast Cancer Risk

Monday, December 7, 2009

Social isolation and related stress could contribute to human breast cancer susceptibility, research from a rat model designed at the University of Chicago to identify environmental mechanisms contributing to cancer risk shows.

The researchers found that isolation and stress result in a 3.3-fold increase in the risk of developing cancer among rats with naturally occurring mammary tumors.

The research establishes, for the first time, that isolation and stress could be a factor in human breast cancer risk, said Martha McClintock, a psychologist at the University of Chicago and an author of a paper in current issue of the Proceedings of the National Academy of Sciences. Researchers at the University have been studying social isolation in the context of breast cancer development after having found that that many women living in high-crime neighborhoods must deal with a variety of stressors, including social isolation. In particular, African American women have been noted to have an earlier onset of breast cancer, although total incidence is similar to women from other ancestries.

"We need to use these findings to identify potential targets for intervention to reduce cancer and other and its psychological and social risk factors," said McClintock, the David Lee Shillinglaw Distinguished Service Professor in Psychology and Comparative Human Development at the University. "In order to do that, we need to look at the problem from a variety of perspectives, including examining the sources of stress in neighborhoods as well as the biological aspects of cancer development."

The results of the study are published in a PNAS paper titled, "Social Isolation Dysregulates Endocrine and Behavioral Stress While Increasing Malignant Burden of Spontaneous Mammary Tumors." Gretchen Hermes, a former researcher at the University and now a resident in psychiatry at the Yale University School of Medicine, is lead author of the study.

The paper is part of a series of publications by University of Chicago researchers exploring the connection between social isolation and breast cancer biology, and part of an ongoing research program at Chicago where work is being done on cancer by researchers from a wide number of disciplines. That work was enabled by the University's Biopsychological Sciences Building, designed for such interdisciplinary research on behavior and biology and enhanced when the University received a $10 million grant from the National Institutes of Health to finance its Center for Interdisciplinary Health Disparities Research and is supported by the University of Chicago Cancer Research Center.

The study published in PNAS found that isolation led to a higher production of a stress hormone, corticosterone, among rats that were kept alone and subjected to the disturbances of colony life as well as stressful situations, such as the smell of a predator or being briefly constrained. Additionally, the isolated rats took longer to recover from a stressful situation than rats that lived together in small groups.

The study also suggests a causal relationship between social interaction and disease by showing that living alone first causes rats to have higher stress hormones, beginning in young adulthood, become fearful, anxious and vigilant and then prone to malignancy in late-middle age. The study further showed that the stress hormone receptor entered the nucleus of mammary tumor cells in isolated rats, where gene regulation occurs, something that happened less often in the cells of the non-isolated rats.

The researchers further found that rats living in isolation experienced a 135 percent increase in the number of tumors and a more than 8,000 percent increase in their size. The impact of isolation was much larger than the impact another environmental source of tumor formation -- the unlimited availability of high-energy food.

In natural situations, estrogen and progesterone produced from ovaries play a role in the majority of naturally occurring mammary and breast cancers tumors. In the rat study, tumors naturally developed in late middle age, while ovaries were no longer fully functioning, further suggesting the role of isolation and stress hormones in cancer development.

Joining McClintock and Hermes in preparing the PNAS paper were Bertha Delgado, researcher at Ben Gurion University, Israel; Maria Tretikova, Resident in Pathology at the University of Chicago Medical Center; Sonia Cavigelli, Assistant Professor of Biobehavioral Health at Penn State University; Thomas Krausz, Director of Anatomic Pathology at the University; and Suzanne Conzen, Associate Professor of Medicine at the University. The National Institute of Environmental Health Sciences/National Cancer Institute, the U.S. Department of Defense, and the State of Connecticut Department of Mental Health and Addictive Services supported the research.

The paper is part of a series published by McClintock and her colleagues using animal models to study the onset of cancer.

Rats provide an excellent model for studying human health. They are gregarious animals that are constantly interacting, with complex social relationships and shared care for their young. Additionally, isolation is a natural part of their social order, as a rat stands sentry at each colony and needs to be extremely vigilant to danger on behalf of the rest of the group.

A paper published by University researcher Jason Yee and colleagues showed that rats that developed reciprocal supportive relationships during stress, in which they both asked for help and gave assistance to others, were likely to live longer. That research was reported in "Reciprocal Affiliation Among Adolescent Rats During a Mild Group Stressor Predicts Mammary Tumors and Lifespan," in the journal Psychosomatic Medicine.

Hermes was lead researcher in a paper published in Developmental Psychobiology that isolation disrupts the development of puberty in rats by accelerating maturation of ovarian function while simultaneously delaying mammary tissue development. As a result, the rats are more likely to development mammary tumors. The work was in a paper, "Isolation and the Timing of Mammary Gland Development, Gonadarche and Ovarian Senescence: Implications for Mammary Tumor Burden."

In a paper in the American Journal of Physiology, Hermes and McClintock reported that isolation caused a more pronounced inflammatory disease response in females than in males. That work was published in the paper "Social isolation and the inflammatory response: Sex differences in the enduring effects of a stressor."

More recently, in a paper published in Cancer Prevention Research, Conzen and McClintock reported that social isolation of a genetic mouse model of human breast cancer resulted in larger mammary tumor growth. In a paper titled "A model of gene-environment interaction reveals altered mammary gland gene expression and increased tumor growth following social isolation," Conzen and McClintock showed that social isolation was associated with the increased expression of specific sets of genes involved in metabolism and inflammation.

Source: University of Chicago

Permalink: http://www.sflorg.com/comm_center/unv_medical/p975_238.html

Time Stamp: 12/7/2009 at 8:15:38 PM UTC

With Amino Acid Diet, Mice Improve After Brain Injury

SFL ORG. Educational News Network — Mon, 07 Dec 2009 20:00:01 +0000

Under Embargo Till: 20:00 UTC December 07, 2009
Posted: 20:00 UTC 12/07/2009

With Amino Acid Diet, Mice Improve After Brain Injury

Monday, December 7, 2009

Neurology researchers have shown that feeding amino acids to brain-injured animals restores their cognitive abilities and may set the stage for the first effective treatment for cognitive impairments suffered by people with traumatic brain injuries.

"We have shown in an animal model that dietary intervention can restore a proper balance of neurochemicals in the injured part of the brain, and simultaneously improves cognitive performance," said study leader Akiva S. Cohen, Ph.D., a neuroscientist at The Children's Hospital of Philadelphia.

If these results in mice can be translated to human medicine, there would be a broad clinical benefit. Every 23 seconds, a man, woman or child in the United States suffers a traumatic brain injury (TBI). The primary cause of death and disability in children and young adults, TBI also accounts for permanent disabilities in more than 5 million Americans. The majority of those cases are from motor vehicle injuries, along with a rising incidence of battlefield casualties.

Although physicians can relieve the dangerous swelling that occurs after a TBI, there are currently no treatments for the underlying brain damage that brings in its wake cognitive losses in memory, learning and other functions.

The animals in the current study received a cocktail of three branched chain amino acids (BCAAs), specifically leucine, isoleucine and valine, in their drinking water. Previous researchers had shown that people with severe brain injuries showed mild functional improvements after receiving BCAAs through an intravenous line.

BCAAs are crucial precursors of two neurotransmitters -- glutamate and gamma-aminobutyric acid, or GABA, which function together to maintain an appropriate balance of brain activity. Glutamate excites neurons, stimulating them to fire, while GABA inhibits the firing. Too much excitement or, too little, and the brain doesn't work properly. A TBI upsets the balance.

In particular, a TBI frequently damages the hippocampus, a structure deep in the brain involved in higher learning and memory. In the current study, the researchers found that an injury to the hippocampus reduced levels of BCAAs. Although overall levels of glutamate and GABA were unchanged, the loss of BCAAs disturbed the critical balance of neurotransmitters in the hippocampus, making some localized regions more excitable and others less excitable. Cohen's team tested the hypothesis that providing dietary BCAAs would restore the balance in neural response.

In this study, Cohen's study team first created standardized brain injuries in mice, and one week later compared the animals' conditioned fear response to that of uninjured mice. A week after receiving a mild electric shock in a specific cage, normal mice tend to "freeze" when placed in the same cage, anticipating another shock. The brain-injured mice demonstrated fewer freezing responses -- a sign that they had partially lost that piece of learning.

On the other hand, brain-injured mice that received a diet of BCAAs showed the same normal response as the uninjured mice. The BCAA cocktail had restored their learning ability.

In addition to the behavioral results, the team conducted electrophysiological experiments in slices of hippocampus from brain-injured and non-injured mice, and showed that BCAA restored a normal balance of neural activity. "The electrophysiological results were consistent with what we saw in the animals' functional recovery," said Cohen.

If the results in mice can be reproduced in people, patients with traumatic brain injuries could receive the BCAAs in a drink. Cohen suggests that BCAAs as a dietary supplement could have a more sustained, measured benefit than that seen when patients receive BCAAs intravenously, in which the large IV dose may flood brain receptors and have more limited benefits.

Although much work remains to be done to translate the finding into a therapy, Cohen expects to collaborate over the next year with other researchers in an early-phase clinical trial of dietary BCAAs in patients with mild to moderate TBI.

The National Institutes of Health provided funding for this study. Cohen's co-authors were Jeffrey Cole, Ph.D., Christina M. Mitala, Ph.D., Suhali Kundu and Itzhak Nissim, Ph.D., all of Children's Hospital; Jaclynn A. Elkind of the University of Pennsylvania; and Ajay Verma, M.D., Ph.D., of the Uniformed Services University of the Health Sciences, Bethesda, Md. Cohen and Nissim are also on the faculty of the University of Pennsylvania School of Medicine.

The study appears today in the online issue of the Proceedings of the National Academy of Sciences.

Source: Children's Hospital of Philadelphia
Permalink: http://www.sflorg.com/comm_center/medical/p974_99.html
Time Stamp: 12/7/2009 at 20:00: UTC

A See-Through Surprise

SFL ORG. Educational News Network — Mon, 07 Dec 2009 18:35:20 +0000

A See-Through Surprise

Monday, December 7, 2009

Rice lab makes solid material transparent to terahertz waves

Very often in science, the unexpected discovery turns out to be the most significant. Rice University Professor Junichiro Kono and his team weren't looking for a breakthrough in the transmission of terahertz signals, but there it was: a plasmonic material that would, with adjustments to its temperature and/or magnetic field, either stop a terahertz beam cold or let it pass completely.

The finding by Kono, a professor in electrical and computer engineering and in physics and astronomy, former graduate student Xiangfeng Wang and their colleagues helps close a knowledge gap in the electromagnetic spectrum between the ranges that address electronic and photonic devices.

Their paper, "Interference-Induced Terahertz Transparency in a Magneto-Plasma in a Semiconductor," appears in today's online version of the journal Nature Physics and will be published in the Dec. 24 edition. Co-authors include Texas A&M theoretical physicist Alexey Belyanin, Los Alamos National Laboratory physicist Scott Crooker and Daniel Mittleman, a Rice professor in electrical and computer engineering.

Kono's team had been studying the conductivity of indium antimonide. "This is a classic material people started working on in the 1940s," he said. "It's a typical semiconductor, and if you dope it, it's highly conductive. But if you apply a magnetic field, it becomes an insulator, and that's what we planned to look at."

When Wang used terahertz spectroscopy to study the material, its unusual properties became apparent. "He started tuning various parameters -- the magnetic field, temperature and then the frequency -- and found that the terahertz transmission of the material changed drastically," Kono said. "It went from opaque to transparent."

They found that in a magnetic field, the doped indium antimonide, a solid-state plasma, transmitted circularly polarized waves that interfered with each other. This affected terahertz beams in much the same way polarized sunglasses interfere with visible light. To their surprise, at particular combinations of settings, the beams would pass right through.

"Terahertz is an exciting field right now," said Kono, a newly named fellow of the American Physical Society whose lab focuses on the physics and applications of semiconductor nanostructures and quantum devices. "This frequency range is considered to be the last frontier of the electromagnetic spectrum."

Kono said neither type of semiconductor device in common use today -- photonic and electronic -- works in the terahertz range. "Photonic devices work in the visible and near-infrared ranges and electronic devices work in the kilohertz, megahertz and gigahertz ranges. There's a clear gap where there's no mature solid-state technology. That's why a lot of people are working to fill it."

"I wouldn't say the terahertz region is unexplored, but it's less so," said Mittleman, who specializes in terahertz technologies and worked on the development of a terahertz version of Rice's famous single-pixel camera. "There are some open problems that people haven't thought about -- or have thought about, but haven't found good solutions for. The whole technology base is a lot less mature."

Kono said applications for terahertz technology include imaging, spectroscopy and communications, and having a device that can serve as a terahertz switch would be a step forward.

Still, there are hurdles to making the lab's discovery practical, one being the operating temperature. Wang worked with the indium antimonide at temperatures between 2 and 240 kelvins (approximately -456 to -27 degrees Fahrenheit).

"The temperature is certainly a concern," Mittleman said. "If it's going to have impact as a useful device for controlling terahertz beams, there is some work yet to do. I don't think that's impossible, but the route is not immediately clear.

"There's not a lot of shocking new physics here," he said, but the combination of techniques used to treat the indium antimonide made for interesting science. "People are going to think it's pretty cool.

"I think it's nice to find things like this, because it's a great example of an unexpected discovery that could turn out to be really useful."

The National Science Foundation and the Robert A. Welch Foundation supported the research.

Source: Rice University

Permalink: http://www.sflorg.com/comm_center/unv_science/p973_251.html

Time Stamp: 12/7/2009 at 6:22:53 PM UTC