Research Directory

Anti-helium discovered in the heart of STAR

philosoft@live.com (forhad) — Sun, 24 Apr 2011 13:13:00 -0700

Berkeley Lab nuclear scientists join with their international colleagues in the latest record-breaking discovery at RHIC



		IMAGE: Roughly equal amounts of matter and antimatter are created in the collision of energetic gold nuclei inside STAR, but because the fireball expands and cools quickly, antimatter can survive longer...

Eighteen examples of the heaviest antiparticle ever found, the nucleus of antihelium-4, have been made in the STAR experiment at RHIC, the Relativistic Heavy Ion Collider at the U.S. Department of Energy's Brookhaven National Laboratory.

"The STAR experiment is uniquely capable of finding antihelium-4," says the STAR experiment's spokesperson, Nu Xu, of the Nuclear Science Division (NSD) at Lawrence Berkeley National Laboratory (Berkeley Lab). "STAR already holds the record for massive antiparticles, last year having identified the anti-hypertriton, which contains three constituent antiparticles. With four antinucleons, antihelium-4 is produced at a rate a thousand times lower yet. To identify the 18 examples required sifting through the debris of a billion gold-gold collisions."

Collisions of energetic gold nuclei inside STAR briefly recreate conditions in the hot, dense early universe only millionths of a second after the big bang. Since equal amounts of matter and antimatter were created in the big bang they should have completely annihilated one another, but for reasons still not understood, only ordinary matter seems to have survived. Today this excess matter forms all of the visible universe we know.

Roughly equal amounts of matter and antimatter are also produced in heavy-ion (gold nuclei) collisions at RHIC. The resulting fireballs expand and cool quickly, so the antimatter can avoid annihilation long enough to be detected in the Time Projection Chamber at the heart of STAR.

Ordinary nuclei of helium atoms consist of two protons and two neutrons. Called alpha particles when emitted in radioactive decays, they were found in this form by Ernest Rutherford well over a century ago. The nucleus of antihelium-4 (the anti-alpha) contains two antiprotons bound with two antineutrons.



		IMAGE: The track of an antihelium-4 nucleus, highlighted in red, appears in a myriad of tracks produced by a gold-gold collision inside the STAR detector at RHIC. STAR's Time Projection Chamber...

The most common antiparticles are generally the least massive, because it takes less energy to create them. Carl Anderson was the first to find an antiparticle, the antielectron (positron), in cosmic ray debris 1932. The antiproton (the nucleus of antihydrogen) and the antineutron were created at Berkeley Lab's Bevatron in the 1950s. Antideuteron nuclei ("anti-heavy-hydrogen," made of an antiproton and an antineutron) were created in accelerators at Brookhaven and CERN in the 1960s.

Each extra nucleon (called a baryon) increases the particle's baryon number, and in the STAR collisions every increase in baryon number decreases the rate of yield roughly a thousand times. The nuclei of the antihelium isotope with only one neutron (antihelium-3) has been made in accelerators since 1970; the STAR experiment produces many of these antiparticles, having baryon number 3. The antihelium nucleus with baryon number 4, just announced by STAR based on 16 examples identified in 2010 and two examples from an earlier run, contains the most nucleons of any antiparticle ever detected.

"It's likely that antihelium will be the heaviest antiparticle seen in an accelerator for some time to come," says STAR Collaboration member Xiangming Sun of Berkeley Lab's NSD. "After antihelium the next stable antimatter nucleus would be antilithium, and the production rate for antilithium in an accelerator is expected to be well over two million times less than for antihelium."

NSD's Maxim Naglis adds, "Finding even one example of antilithium would be a stroke of luck, and would probably require a breakthrough in accelerator technology."

If antihelium made by accelerators is rare, and heavier antiparticles rarer still, what of searching for these particles in space? The Alpha Magnetic Spectrometer (AMS) experiment, scheduled to be launched on one of the last space-shuttle missions to the International Space Station, is an instrument designed to do just that. A principal part of its mission is to hunt for distant galaxies made entirely of antimatter.

"Collisions among cosmic rays near Earth can produce antimatter particles, but the odds of these collisions producing an intact antihelium nucleus are so vanishingly small that finding even one would strongly suggest that it had drifted to Earth from a distant region of the universe dominated by antimatter," explains Hans Georg Ritter of Berkeley Lab's NSD. "Antimatter doesn't look any different from ordinary matter, but AMS finding just one antihelium nucleus would suggest that some of the galaxies we see are antimatter galaxies."

Meanwhile the STAR experiment at RHIC, which has shown that antihelium does indeed exist, is likely to hold the world record for finding the heaviest particle of antimatter for the foreseeable future.

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This work was supported by the DOE Office of Science.

Additional information

For more about the discovery of the antihelium-4 nucleus, read the Brookhaven press release at http://www.bnl.gov/bnlweb/pubaf/pr/PR_display.asp?prID=1259.

STAR's Time Projector Chamber is a cylinder filled with dilute gas and placed in a uniform (solenoidal) magnetic field (STAR stands for Solenoidal Tracker at RHIC). Charged particles created in beam collisions ionize the gas as they streak through it; how much the trails bend in the magnetic field reveals their momentum. Detecting antihelium also depends on measuring particle mass, which can be learned from how much energy the particles lose in flight and how long it takes them to reach the sides of the cylinder.

A series of "event triggers" picks out particles matching the specifications of those the researchers are looking for. The data generated by STAR travel to the National Energy Research Scientific Computing Center (NERSC), managed by Berkeley Lab, via DOE's high-bandwidth Energy Sciences Network (ESnet).

Time projection chambers were invented by David Nygren of Berkeley Lab's Physics Division and are used at accelerators around the world; the time-projection-chamber principle inspired the original proposals for the STAR experiment within Berkeley Lab's NSD. STAR's Time Projection Chamber was designed by NSD's Howard Wieman, built by Berkeley Lab physicists and engineers, and shipped to Brookhaven on a C-5 cargo plane.

The installation of a large time-of-flight detector in 2009 added measurement capabilities to STAR that were vital to the identification of antihelium-4. It was constructed jointly by U.S. and Chinese institutions and jointly funded by DOE's Office of Science and the National Natural Science Foundation of China, China's Ministry of Science and Technology, and the Chinese Academy of Sciences.

Lawrence Berkeley National Laboratory addresses the world's most pressing scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab's scientific expertise has been recognized with 12 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy's Office of Science. For more, visit http://www.lbl.gov/.

One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Visit Brookhaven Lab's electronic newsroom for links, news archives, graphics, and more (http://www.bnl.gov/newsroom) or follow Brookhaven Lab on Twitter (http://twitter.com/BrookhavenLab).

Contact: Paul Preuss
paul_preuss@lbl.gov
510-486-6249
DOE/Lawrence Berkeley National Laboratory

Jefferson neuroscientists say: Blocking crucial molecule could help treat multiple sclerosis

philosoft@live.com (forhad) — Sun, 24 Apr 2011 13:11:00 -0700

Researchers uncover role of GM-CSF, an inflammatory cytokine, in T helper cells; blocking it could treat multiple sclerosis



		IMAGE: Abdolmohamad Rostami, M.D., Ph.D., professor and chairman of the Department of Neurology at Jefferson Medical College of Thomas Jefferson University, and colleagues have identified a driving force behind autoimmune diseases...

PHILADELPHIA—Reporting in Nature Immunology, Jefferson neuroscientists have identified a driving force behind autoimmune diseases such asmultiple sclerosis (MS), and suggest that blocking this cell-signaling molecule is the first step in developing new treatments to eradicate these diseases.

Researchers led by Abdolmohamad Rostami, M.D., Ph.D., Professor and Chairman of the Department of Neurology at Jefferson Medical College of Thomas Jefferson University, found that GM-CSF, which stands for Granulocyte-macrophage colony-stimulating factor, appears to be the key culprit in the onset of MS, because without it, T helper 17 cells (Th17) cells did not induce the MS-like disease in an experimental animal model.

Th17 cells have been shown to play an important pathogenic role in humans and experimental models of autoim¬mune diseases, but the mechanisms behind this have remained elusive until now.

"There was no connection between GM-CSF and Th17 cells before," said Dr. Rostami. "What we have shown in this paper is that GM-CSF derived from Th17 cells is important in the cell-signaling process that leads to inflammation in the central nervous system."

"Now we know how the Th17 cells work and a better understanding of this mechanism and biology leads to new therapeutics," he adds.

The results suggest that blocking GM-CSF activity may be a successful therapeutic strategy in MS, one of the most common neurological diseases affecting young adults, and other autoimmune diseases, said Dr. Rostami, who is also the Chair of Neurology at Thomas Jefferson University Hospital.

The paper first appears in an advance online publication of Nature Immunology on April 24.

These findings identify the interleukin-23 (IL-23)/ Th17/GM-CSF axis as the major pathway in pathogenesis of autoimmune central nervous system inflammation and likely other autoimmune diseases. IL-23, a known cytokine that causes autoimmune inflammation of the brain, induces production of more GM-CSF in Th17 cells, the researchers explain.

Dr. Rostami, who is also director of the Neuroimmunology Laboratory in the Department of Neurology at JMC, and his colleagues used an animal model of MS called experimental autoimmune encephalomyelitis (EAE) for the investigation, a common model used to study the pathogenesis of the disease. Mice whose Th17 cells cannot produce GM-CSF did not develop neuroinflammation, thus GM-CSF is responsible for disease manifestation in this experimental model. This scenario suggests feed-forward loop of IL-23 and GM-CSF driving the pathogenic encephalitogenic immune response in the brain and spinal cord.

Another recently published paper in Nature Immunology by Dr. Rostami and his team unraveled a mechanism that may help fight MS. The researchers found that a protein known as interkeukin-27 (IL-27) helped block, not induce, the onset of symptoms in animals with an MS-like disease. While increasing levels of GM-CSF may cause the disease, as shown in the current paper, increasing IL-27 concentrations may help quell an over-active immune system, the researchers reported.

"That was the first time that we had direct evidence that by actively giving IL-27 like a drug, we can suppress EAE in mice," Dr. Rostami said.

If similar findings from this current study of GM-CSF are found in human blood samples, this approach could eventually also be shown to be useful in the clinical setting, Dr. Rostami explains.

Whether GM-CSF drives neuroinflammation in MS remains unknown, but the current findings highlight the potential that IL-23 and GM-CSF might serve a similar role in human disease.

"This is the first step towards finding a new treatment," he said. "If we can try to neutralize GM-CSF by different means, for example, by trying to mimic it or trying to block the receptor for GM-CSF, we can hopefully ameliorate the disease."

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Contact: Steve Graff

stephen.graff@jefferson.edu

215-955-5291

Thomas Jefferson University

GM-CSF required for the immune attack in multiple sclerosis

philosoft@live.com (forhad) — Sun, 24 Apr 2011 13:08:00 -0700

The neutralization of the cytokine GM-CSF could halt the development of multiple sclerosis. This was demonstrated by the research team of the immunologist Burkhard Becher at the University of Zurich in an animal model. Unlike other known cytokines, they write in the journal Nature Immunology, this messenger substance is essential for the development of the disease. By the end of this year, a clinical trial will be launched in which GM-CSF is to be neutralized in MS patients.

The immune systems main task is to protect us from pathogenic microorganisms. To do so, an armada of immune cells is diligently instructed to search for invading pathogens. The ability of immune cells to communicate with one another is vital to this protection. Mistakes in the communication can lead to 'misunderstandings' and an erroneous attack against ones own tissues. Such is the case in autoimmune diseases such as multiple sclerosis (MS), rheumatoid arthritis and juvenile diabetes, where the immune system inadvertently attacks the body. So-called helper T cells are chiefly responsible for the fatal immune response.

There are various sub-classes of helper T cells with different tasks and responsibilities. Clinicians and researchers have long been trying to ascertain which sub-class the rogue T cells that attack the body's own organs in autoimmune diseases actually belong to. T cells release certain messenger substances, known as cytokines, which in turn coordinate the appropriate immune response. Until now, the type of T-cell and, above all, the relevant cytokine that causes the inflammation in the brain and spinal cord were not known.

The research team of Professor Burkhard Becher has spent six years testing the relevant cytokines by a process of elimination in transgenic mouse models of multiple sclerosis. Over the years, they were able to cross many factors off the list before eventually hitting the jackpot with GM-CSF (granulocyte macrophage colony-stimulating factor). GM-CSF is produced by a newly discovered subclass of helper T cells. "The MS-like disease could not be induced in mice without GM-CSF," says Becher. "What's more, the disease could even be cured in MS mice if the cytokine was neutralized."

GM-CSF is not a new cytokine; we already knew that it can cause or aggravate inflammation. Apart from GM-CSF, however, all the other cytokines studied thus far only played a minor role. "GM-CSF is therefore the first T-cell cytokine that's essential for the initiation of an inflammatory reaction," says Becher. Furthermore, the researchers were able to demonstrate that the GM-CSF delivered to the brain by T cells activates the recruitment of tissue-damaging scavenger cells. "Without scavenger cells like these, the inflammation can't really get going in the first place and the neutralization of GM-CSF can even reverse the inflammatory process," says the immunologist.

Patients suffering from rheumatoid arthritis are currently being treated with neutralizing antibodies against GM-CSF in a clinical trial. A trial with MS patients is due to begin at the end of 2011. "We're extremely hopeful," says Becher enthusiastically. "But whether this form of therapy will actually help MS patients remains to be seen. Quiet optimism is the way to go," he explains.

Irrespective of the clinical trial, the team expects the study to have a significant impact on basic and clinical research. "We're really making headway; we now understand much better how an inflammatory lesion can develop in the brain."

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Contact: Burkhard Becher
becher@immunology.uzh.ch
41-446-353-701
University of Zurich

Combination therapy provides hope for cure of dangerous infections of cystic fibrosis patients

philosoft@live.com (forhad) — Sun, 24 Apr 2011 13:05:00 -0700

Hamilton, ON (April 24, 2011) – An over-the-counter drug used to treat diarrhea combined with minocycline, an antibiotic used to treat bacterial infections, could one day change the lives of those living with cystic fibrosis.

Researchers at McMaster University have discovered this creative approach to tackle antibiotic resistance to bacterial infections, a frequent complication of those with cystic fibrosis. Cystic fibrosis is the most common, fatal genetic disease affecting Canadian children and young adults.

"Antibiotic resistance is having a profound effect on known drugs that are used to treat illness and disease," says researcher Eric Brown, professor and chair of McMaster's Department of Biochemistry and Biomedical Sciences and member of the Michael G. DeGroote Institute for Infectious Disease Research (IIDR).

"Previous advances in treating cystic fibrosis have been in managing infection, but since infectious organisms are increasingly developing resistance to antibiotics, the importance of providing new treatments is more important than ever."

Brown, who made the discovery in collaboration with McMaster researchers Gerry Wright and Brian Coombes, found that the combination of these two drugs inhibits the growth of bacteria after screening a collection of previously approved non-antibiotic drugs within McMaster's Centre for Microbial Chemical Biology.

Their screening revealed that this particular combination using the anti-diarrhea drug loperamide increases the efficacy of the antibiotic minocycline against multidrug resistant P. aeruginosa.

"Typically it takes 13 to 15 years to develop a drug," says Brown. "We think that this approach could cut drug development time in half."

"These exciting research findings hold promise that a new, safer method for treating devastating lung infections in people with cystic fibrosis may be just around the corner," says Maureen Adamson, CEO, Cystic Fibrosis Canada, a charity that partnered with the Canadian Institutes of Health Research to fund the project. "These findings could impact healthcare worldwide as antibiotic resistance is a tremendous threat to many populations."

Wright, scientific director of the IIDR, adds that McMaster is one of the only universities to look at the combination of antibiotic and non-antibiotic drugs in combating bacterial resistance. But he believes this marks the beginning of using combination therapy as a more effective way to treat disease.

"This finding has opened doors to discovering the abilities of drugs when combined," he says. "Not only has antibiotic resistance become a growing threat to managing illness and disease, the use of combination therapy has added benefits. These combinations might be a way to selectively target bacteria and combat disease and leave so-called "good bacteria" intact to do other things. In effect you use fewer antibiotics to get the same effect."

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The study appears online in the journal Nature Chemical Biology on April 24.

Contact: Laura Thompson
lthomp@mcmaster.ca
905-525-9140, ext. 22196
McMaster University

RHIC Physicists Nab New Record for Heaviest Antimatter

philosoft@live.com (forhad) — Sun, 24 Apr 2011 13:02:00 -0700

Newly discovered antihelium-4 could be heaviest stable antinucleus detectable for decades to come



		IMAGE: This graph plots particle counts by mass, showing ordinary helium nuclei (He-3 and He-4) in orange, and their antimatter counterparts (antihelium-3 and antihelium-4) in blue. The plot illustrates that the

UPTON, NY -- Members of the international STAR collaboration at the Relativistic Heavy Ion Collider -- a particle accelerator used to recreate and study conditions of the early universe at the U.S. Department of Energy's Brookhaven National Laboratory -- have detected the antimatter partner of the helium nucleus: antihelium-4. This new particle, also known as the anti-alpha, is the heaviest antinucleus ever detected, topping a discovery announced by the same collaboration just last year*.

The new record will likely stand far longer, the scientists say, because the next weightier antimatter nucleus that does not undergo radioactive decay is predicted to be a million times more rare - and out of reach of today's technology.

"This discovery highlights the extraordinary capabilities of RHIC to investigate fundamental questions about the nature of matter, antimatter, and the early universe," said William F. Brinkman, Director of the DOE Office of Science.

Steven Vigdor, Brookhaven's Associate Lab Director for Nuclear and Particle Physics, who leads the RHIC program, said, "Barring a new breakthrough in accelerator technology, or the discovery of a completely new production mechanism, it is likely that antihelium-4 will remain the heaviest stable antimatter nucleus observed for the foreseeable future."

The STAR physicists describe the discovery in a paper in Nature, published online April 24, 2011.

The ability to create and study antimatter in conditions similar to those of the early universe is no small matter: One of the great mysteries of physics is why our universe appears to be made entirely of ordinary matter when matter and antimatter are understood to have been created in equal amounts at the time of the Big Bang.

At RHIC, head-on collisions of gold ions moving at nearly the speed of light simulate conditions just after the Big Bang. In these atomic smashups, quarks and antiquarks likewise emerge with approximately equal abundance. A major fraction of the stable antimatter produced in RHIC collisions leaves a clear signal in the STAR detector before annihilating with ordinary matter in the outer part of the experimental apparatus.

By sifting through data for half a trillion charged particles emitted from almost one billion collisions, the STAR collaboration has detected 18 examples of the unique "signature" of the antihelium-4 nucleus. Consisting of two antiprotons and two antineutrons in a stable bound state that does not undergo radioactive decay, the antihelium-4 nucleus has a negative electric charge that is twice that of an electron, while its mass is very close to four times that of a proton. Data plots show that the newly discovered anti-alphas are very cleanly separated from the lighter isotopes, and are at the expected mass.



		IMAGE: This rendering shows antihelium-4 (anti-alpha) emerging from a collision in the Relativistic Heavy Ion Collider at Brookhaven National Laboratory.

The scientists also measured the antihelium-4 production rate in nuclear interactions, and found that it is consistent with expectations based on a statistical coalescence of antiquarks from the soup of quarks and antiquarks generated in RHIC collisions. But the fact that 12 antiquarks combine to build such a complex antinucleus in a way that bears out these predictions is really quite remarkable considering it all takes place in the midst of rapidly expanding matter created at trillions of degrees and surviving for only ten trillionths of a trillionth of a second.

Knowing the production rate of these antinuclei is important to a wide range of scientific disciplines, including searches for new phenomena in the cosmos. For example, it ties in with the scientific goals of an experiment known as the Alpha Magnetic Spectrometer (AMS), which will be delivered to the International Space Station via one of the last space shuttle missions, currently scheduled for launch in late April 2011. This experiment will search for antimatter in space.

"If AMS were to find evidence for the existence of bulk antimatter elsewhere in the cosmos, the new measurement from the STAR experiment would provide the quantitative background rate for comparison," said Hank Crawford, a STAR collaborator from the University of California, Berkeley, Space Sciences Laboratory. "An observation of antihelium-4 by the AMS experiment could indicate the existence of large quantities of antimatter somehow segregated from the matter in our universe," he said.

In 2010, the Large Hadron Collider at CERN, the European laboratory for nuclear and particle physics research, began its own collisions of heavy nuclei at energies more than an order of magnitude higher than at RHIC. Experiments there also have the capability to study production of antinuclei, and it will be interesting to see what those experiments find at higher energies.

"The discovery of the antihelium-4 nucleus also has special synergy with a major scientific anniversary: the 100th anniversary of Ernest Rutherford's seminal gold foil experiments, in which he used ordinary-matter helium-4 (alpha) particles to probe the structure of matter," said Brookhaven physicist Aihong Tang, a member of the STAR collaboration and a lead author on the Nature paper. "These experiments, conducted in 1911, established the very existence of atomic nuclei for the first time, and marked the dawn of our modern understanding of atoms."

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The STAR collaboration is composed of 54 institutions from 12 countries. Research at RHIC is funded primarily by the U.S. Department of Energy's Office of Science and by various national and international collaborating institutions, with support from many funding agencies (see: http://www.bnl.gov/rhic/funding.asp) Measurement capabilities vital to antihelium-4 identification were added to the STAR experiment in 2009 with the installation of a large time-of-flight detector. This device was constructed jointly by U.S. and Chinese institutions and was funded jointly by DOE's Office of Science and the National Natural Science Foundation of China, China's Ministry of Science and Technology, and the Chinese Academy of Sciences. The antihelium-4 discovery is being announced simultaneously in the U.S. and in China.

RNA dynamics deconstructed

philosoft@live.com (forhad) — Sun, 24 Apr 2011 12:59:00 -0700

Technique offers detailed view of how RNA levels change

RNA plays a critical role in directing the creation of proteins, but there is more to the life of an RNA molecule than simply carrying DNA's message. One can imagine that an RNA molecule is born, matures, and eventually, meets its demise. Researchers at the Broad have developed an approach that offers many windows into the lifecycle of these essential molecules and will enable other scientists to investigate what happens when something in a cell goes wrong. They describe their approach, which offers high resolution and a comprehensive scope, in a Nature Biotechnology article published online on April 24.

"People are discovering more and more how the RNA lifecycle is at the heart of problems we see in disease, but we actually understand a lot less about it than we understand about many other cellular processes," said Aviv Regev, a core faculty member of the Broad Institute and a co-senior author on the paper.

Regev and her colleagues have developed a method that allows them to tease apart the different stages of this lifecycle by measuring how much messenger RNA is produced and how much is degraded. The balance of these two processes contributes to the changes seen in RNA levels in a cell over time, much the way that birth and death rates contribute to a country's total population.

RNA levels are dynamic – they change in response to certain stimuli. For this study, the researchers examined dendritic cells, which are involved in the body's immune response, as a model. They exposed these cells to a stimulus that resembled a pathogen and then looked at RNA changes before and after exposure.

"We wanted to understand how cells regulate RNA levels, and if regulation happens at the step of producing the molecule, degrading the molecule, or processing it," said Michal Rabani, first author of the paper and an MIT graduate student at the Broad. "Each of these steps can affect the level of active RNA molecules in cells. If you want to understand what happens when things go wrong, you have to understand how things work when they work as they should."

The researchers' approach allows them to look at a specific cell type and see changes in the expression of all genes. This combination of breadth and specificity offers a systematic view of how RNA changes over time. "If we want to look at specific neurons in the brain or a specific cell that's lying between other kinds of cells in the lung, this technique allows us to zoom in on one process in one cell among a billion other cells. This is the case in many diseases, a short circuit in one specific cell type, and now we have a great tool to find it," said Ido Amit, a co-senior author of the paper and a scientist at the Broad.

The scientists harnessed an existing technique to trace the fate of newly produced RNA and paired it with a new sequencing-based technology that counts molecules of mRNA. The results also gave the researchers a view of some of the in-between steps, during which mRNA is edited or processed – an unexpected but serendipitous finding. "That's the beauty of sequencing: it has a very extensive view so it shows you things you didn't expect to see," said Regev.

A key aspect of the approach is that the researchers were able to take "snapshots" of RNA levels over very short time intervals. Strung together, these snapshots reveal not only how the amount of RNA changes, but also the short-lived, intermediate phases of the RNA lifecycle that are otherwise impossible to detect. "This allows us many windows into the world of RNA," said Amit.

One critical application of the new method is in following up on leads from disease studies, such as mutated genes in cancer or other diseases that impact the RNA lifecycle. "In the past, you would know that there's a mutation and there's even a suspicion of what the gene does, but it would have been extraordinarily hard to see the effect of the mutation on these types of processes in the cell," said Regev, who is also an assistant professor at MIT and an early career scientist at the Howard Hughes Medical Institute. The researchers hope that their newly developed technique will enable others to gain deep insights into how gene mutations disrupt RNA levels, and in turn, what proteins are made.

"We're decomposing these RNA levels, breaking them down into each separate step, so that we can understand what happens at each of these steps and how they interact with each other to produce the final read out," said Rabani. "It's a very complex system, but understanding it could eventually help us understand what goes wrong when things don't work."

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This work was supported by the Richard Merkin Foundation for Stem Cell Research at the Broad Institute through a gift that Regev describes as essential for the project's success.

Paper cited:

Rabani M et al. Metabolic labeling of RNA uncovers principles of RNA production and degradation dynamics in mammalian cells. Nature Biotechnology. April 24, 2011. DOI: 10.1038/nbt.1861

About the Broad Institute of Harvard and MIT

The Eli and Edythe L. Broad Institute of Harvard and MIT was launched in 2004 to empower this generation of creative scientists to transform medicine. The Broad Institute seeks to describe all the molecular components of life and their connections; discover the molecular basis of major human diseases; develop effective new approaches to diagnostics and therapeutics; and disseminate discoveries, tools, methods and data openly to the entire scientific community.

Founded by MIT, Harvard and its affiliated hospitals, and the visionary Los Angeles philanthropists Eli and Edythe L. Broad, the Broad Institute includes faculty, professional staff and students from throughout the MIT and Harvard biomedical research communities and beyond, with collaborations spanning over a hundred private and public institutions in more than 40 countries worldwide. For further information about the Broad Institute, go to http://www.broadinstitute.org.

About the Richard Merkin Foundation for Stem Cell Research at the Broad Institute

The Richard Merkin Foundation for Stem Cell Research at the Broad Institute seeks to fund Broad Institute-affiliated scientists to develop a novel and comprehensive "toolbox" of experimental methods and computational algorithms and to apply those tools to understand cellular circuitry in stem cells, with the goal of being able to manipulate those circuits for both biological knowledge and medical applications.

Contact: Nicole Davis
ndavis@broadinstitute.org
617-714-7152
Broad Institute of MIT and Harvard

Brain cell migration during normal development may offer insight on how cancer cells spread

philosoft@live.com (forhad) — Sun, 24 Apr 2011 12:57:00 -0700

SEATTLE – By shedding new light on how cells migrate in the developing brain, researchers at Fred Hutchinson Cancer Research Center also may have found a new mechanism by which other types of cells, including cancer cells, travel within the body. The findings by Jonathan Cooper, Ph.D., member and director of the Hutchinson Center's Basic Sciences Division, and Yves Jossin, Ph.D., a research fellow in Cooper's laboratory, published online April 24 in Nature Neuroscience, could lead to a better understanding of neurological development and, possibly, cancer metastasis.

During normal development cells divide, arrange themselves in appropriate patterns, and specialize to form discrete tissues and organs. For the body to develop properly, cells must coordinate their migratory patterns and the process by which they differentiate, or evolve from less-specialized cells into more-specialized cell types. A lack of such coordination leads to disordered development and, in some cases, cancer.

Jossin and Cooper set out to analyze how cells migrate in the cerebral cortex of the developing brain. The cerebral cortex, gray matter of the cerebrum, is the brain's command and control center where cognition and planning occur, and it is particularly well developed in humans.

The cerebral cortex is composed of horizontal layers of nerve cells, or neurons, which are specialized for different functions and connected vertically into circuits. If some neurons are in the wrong layers, the wiring can be defective and neurological disorders including epilepsy, autism and schizophrenia may result.

In the fetus, the cortex grows "from the inside out" via the sequential addition of new neurons, which move from the inside, pass between neurons in previously established intermediate layers, and form new layers on the outside. How the migrations are regulated remains unclear despite years of study.

Jossin and Cooper now report the discovery of signals that control a particular stage in a cortical neuron's journey. New neurons initially move in a straight line, from the inside to the outside, until they reach a layer called the intermediate zone. This zone contains relatively few neurons but many connecting fibers, or axons. When new neurons reach this layer, they lose their way and start wandering – up, down, left and right, frequently changing direction. When, seemingly by chance, they emerge from the intermediate zone, they realign with their original direction of movement and speed ahead through layers of differentiated neurons towards the outer surface of the cortex.

The researchers aimed to determine how neurons get back on track after they emerge from the chaos of the intermediate zone. They identified a signaling protein, called Reelin, which is made by cells in the outermost layer of the cortex. It has been known for years that mutations in the Reelin gene cause profound cortical layering abnormalities in rodents and people, but it has been unclear which stage of neuron migration goes awry when Reelin is absent.

The new study shows that new neurons respond to Reelin as they emerge from the intermediate zone. "This is remarkable because the top layer of the cortex, where Reelin is made, is widely separated from the top of the intermediate zone, where it acts, so the Reelin protein must be diffuse," Cooper said. "It is also remarkable that Reelin seems not to be a direction signal itself. Rather, Reelin triggers changes in the membranes of the migrating neurons that allow the cells to respond to direction signals."

The researchers show that a membrane protein called N-cadherin increases on the surface of neurons when the neurons encounter Reelin. The surface increase in N-cadherin allows the cell to choose the appropriate direction for its next stage of migration. "This represents a new and surprising function for N-cadherin," Jossin said, "because normally this protein acts as a cellular stabilizer and not as an orchestrator of migration."

For example, elsewhere in the cortex, N-cadherin forms tight adhesions between adjacent cells and prevents them from moving. Indeed, the general role for cadherins in the body is to stabilize sheets of cells and organize tissues by holding cells together.

"The new role for N-cadherin in orienting migrating cells is quite unexpected and suggests that cadherins on the surface of other types of normal or cancer cells may also be involved in helping them move rather than stay in place," Jossin said. "This finding could provide new clues to how normal and cancerous cells migrate within the body," he said.

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This research was funded in part by the National Institutes of Health and a Marie Curie Fellowship from the European Union.

At Fred Hutchinson Cancer Research Center, our interdisciplinary teams of world-renowned scientists and humanitarians work together to prevent, diagnose and treat cancer, HIV/AIDS and other diseases. Our researchers, including three Nobel laureates, bring a relentless pursuit and passion for health, knowledge and hope to their work and to the world.www.fhcrc.org

Contact: Kristen Woodward
kwoodwar@fhcrc.org
206-667-5095
Fred Hutchinson Cancer Research Center

Tecnalia develops a system for heat collection from asphalt pavements

philosoft@live.com (forhad) — Sun, 13 Feb 2011 01:18:00 -0800

Tecnalia, through its Construction Unit, is participating in the Pavener project, aimed at developing a system for collecting the solar energy absorbed by asphalt paved surfaces. The two-year project is being led by the Campezo Group. The Group is focusing on quality control and research project development through its Research and Quality Control Laboratory, and presently this is one of its key projects.

The system involves collecting solar energy accumulated in pavements by circulating a fluid through pipes installed below the surface. This method works similarly to a solar collector incorporated into the pavement. The system can be implemented below any paved surface exposed to solar radiation, such as roads, pavements, car parks, airport landing runways and aprons, etc. Asphalted paved surfaces can heat up 70 degrees in days of strong sunlight, and given the large paved surface area available, there is a great potential for the recovery of this energy.

Multiple applications

The system can be designed for multiple applications, the most novel of these being its use as a solar collector, with great potential in the building sector. Incorporating concepts such as heat storage and heat pumps into the developed system, the accumulated solar energy may be used in low-temperature applications such as the air-conditioning of buildings, sports and leisure centres, swimming pools, and hot water supply. Another potential application of the system is its use for maintaining the temperature of the asphalt above freezing levels in winter, thus preventing the formation of ice on the roads. Apart from the benefits to road safety, this would reduce the amount of salt needed to be used to prevent frost.

The system would reduce consumption of fossil fuels, as well as greenhouse gas emissions to the atmosphere, as a renewable source of energy is exploited. Moreover, the maintenance required for roads is reduced, as road surface temperature can be maintained stable both in winter and in summer, thus reducing the appearance of cracks and grooves in the paved surfaces. An additional advantage of the system is the reduction of the urban heat island effect, as excess heat is extracted from the paved surfaces.

Simulation tasks

The Construction Unit at Tecnalia is researching into the thermal and mechanical properties of the system through experimental simulations and measurements, with the goal of optimising the system configuration depending on the application. Structural stability and thermal behaviour are the key aspects to consider in the development of the system.

The performance of the system will be further studied after the construction of a prototype installation.

Bing Energy relocates to partner with FSU on high-tech fuel cells

philosoft@live.com (forhad) — Sun, 13 Feb 2011 01:17:00 -0800

Bing Energy relocates to partner with FSU on high-tech fuel cells



		IMAGE: This is Professor Jim P. Zheng of Florida State University. Click here for more information.

Florida Gov. Rick Scott today announced that Bing Energy Inc. of Chino, Calif., has selected Tallahassee as the new site of the company's world headquarters. The company, in collaboration with Professor Jim P. Zheng of The Florida State University, is planning to turn revolutionary nanotechnology pioneered at FSU into a better, faster, more economical and commercially viable fuel cell. The move is expected to create at least 244 jobs paying an average wage of $41,655 in Florida.
"I am proud to welcome Bing Energy and thank them for recognizing that Florida is the best state in the nation," Scott said. "As governor, I am continuing to make it the best place to do business. This is only the beginning. Just as Bing Energy was convinced to bring jobs here, I am talking to companies across the nation. I am letting them know that our reduction in the business tax burden, commitment to job creation, and Florida's world-class work force mean we are open for business."
Bing Energy, a manufacturer of state-of-the-art components for polymer electrolyte membrane fuel cells, will begin production in March 2011 and serve the domestic and international energy markets.
"We know that, with the continuing support of Gov. Scott, the Legislature and the people of Florida, our institutions of higher learning will continue to foster innovation, and jobs will continue to cluster around those innovations," said Florida State University President Eric J. Barron. "The breakthrough research by Drs. Wang and Zheng and the company's decision to come to Florida confirm that the investment made in their work by our state and the federal government has realized its commercial potential. Bing Energy represents the future, and Florida State is proud to be a part of it."



		IMAGE: This is President Barron (foreground) and Florida Governor Rick Scott (background).

Bing is moving its global headquarters to Tallahassee to work in partnership with Zheng, who has pioneered a fuel cell that incorporates a thin membrane composed of carbon nanotubes, reducing the need for expensive platinum components that, until now, have made fuel cells too expensive to be widely marketed. Zheng's technology is based on pioneering research and development of buckypaper conducted at Florida State's High-Performance Materials Institute. The institute's director, Professor Ben Wang, is the assistant vice president for research at Florida State.
Bing Energy's innovation promises to produce a fuel cell that is more efficient, more durable and significantly less expensive – benefits that could transform the transportation and power generation sectors.
Joining Scott and Barron in celebrating Bing Energy's move to Tallahassee were Bing Energy CFO Dean Minardi, Tallahassee Mayor John Marks, and representatives from the Economic Development Council of Tallahassee/Leon County Inc.
"We all know the world's existing energy-use pattern is unsustainable," Minardi said. "A commercially viable fuel cell will transform the way we drive, reducing our dependence on fossil fuels. It will transform the way we deliver energy to neighborhoods, ensuring reliability and eliminating the risk of brownouts."
Bing Energy's move to Florida is tied to a $1.9 million award the company recently received from the Governor's Office of Tourism, Trade and Economic Development. The award is a Qualified Target Industry (QTI) Tax Refund in support of job creation. The local Tallahassee and Leon County governments are also supporting Bing Energy by each providing a 10 percent match on the QTI Award.
Gov. Scott has stated that creating jobs is his top priority. As governor, he has announced plans to create 700,000 jobs over the next seven years by implementing accountability budgeting, reducing government spending, enacting regulatory reform, focusing on job growth and retention, investing in world class state universities, reducing property taxes and phasing out the business income tax.
Local officials expressed delight that Tallahassee was chosen by Bing Energy as its relocation site.
"Our organization identified tax incentives and work-force training programs that gave Tallahassee the edge over other communities under consideration," said Kim Williams, chairman of the Economic Development Council of Tallahassee/ Leon County Inc. "This is a perfect example of why connecting industry, education and government is so important. In this case, these connections helped us to retain our talent, as well as our university technologies and commercialization within our community."
Tallahassee Mayor John Marks spoke of the importance of creating jobs in his community and "retaining one of our greatest assets, our work-force talent. The city of Tallahassee is committed to doing our part to help this promising company establish its roots in our community."
Marks' comments were echoed by John Dailey, chairman of the Leon County Commission.
"The county is committed to working with our public and private sectors, especially our universities, to help businesses locate in our community," Dailey said.

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Additional information on the Bing Energy-FSU licensing agreement is available at http://www.fsu.com/News/FSU-signs-licensing-agreement-with-technology-company-Bing-Energy.

New initiative provides materials to help lower radiation dose in pediatric fluoroscopic procedures

philosoft@live.com (forhad) — Sun, 13 Feb 2011 01:15:00 -0800

Washington, DC — The Image Gently campaign has developed easily accessible online teaching materials and checklists to help providers use the lowest dose necessary to perform fluoroscopic procedures on children. Physicians, medical physicists, and radiologic technologists are encouraged to visit the Image Gently Web site (www.imagegently.org) to review these important materials and factor the information into their clinical decision making.

The Image Gently campaign is conducted by the Alliance for Radiation Safety in Pediatric Imaging, founded by the Society for Pediatric Radiology (SPR), the American College of Radiology (ACR), the American Society of Radiologic Technologists (ASRT), and the American Association of Physicists in Medicine (AAPM), and now encompasses more than 50 medical organizations serving more than 500,000 health care providers world-wide.

There is no doubt that fluoroscopic procedures help improve and save lives. However, children are more sensitive to radiation than adults, and cumulative radiation exposure to their smaller, developing bodies could, over time, have adverse effects.

When fluoroscopic procedures are indicated, providers where appropriate areurged to:

Pause and child-size the technique (match kVp and mAs to size of child)
Use lowest pulse rate possible
Limit fluoroscopic time and limit use of magnification mode
Carefully collimate area of interest and utilize appropriate shielding
Utilize pulsed digital fluoroscopic equipment with adjustable frame speeds and last image hold and capture capability.
Consider ultrasound or, when applicable, MRI

"The diagnostic results that these procedures provide, as with all medical techniques, also come with their own potential questions and concerns. This extension of the Image Gently initiative gives providers real world, practical guidance to help ensure that the radiation dose administered to children via these procedures is as low as possible given the particular circumstances of each case," said Marta Hernanz-Schulman MD, FAAP, FACR, chair, ACR Pediatric Guidelines and Standards Committee, past President of the SPR and member of the Alliance Steering Committee, who is leading the diagnostic fluoroscopy component of the Image Gently campaign.

New on the Image Gently Website are:

Downloadable presentation for use by providers to teach their staff methods to reduce dose and maintain quality. Radiologists are encouraged to give this talk locally
Downloadable checklist of dose reduction steps the team should review for each patient
Downloadable outline of dose reduction and quality maintenance steps to take in the department
Information for pediatricians and parents regarding fluoroscopic procedures in children

"Healthcare providers want to ensure that these lifesaving procedures are performed with the utmost care and safety in children. Pediatric patient care is greatly improved during fluoroscopy by collaboration of professionals across multiple disciplines. The information provided on the Image Gently Website provides a basis for interaction among the radiologists, the radiologic technologists, qualified medical physicists and other team members to improve image quality at reduced radiation doses to the patient," said Maryellen L. Giger, Ph.D., FAAPM, FAIMBE, President of the American Association of Physicists in Medicine.

Referring physicians are encouraged to ask the following of any imaging provider to whom they refer their pediatric patients:

If the facility is accredited by the ACR
If the technologists are certified or licensed, and whether they have experience with children
How frequently the facility performs the requested fluoroscopic study in children
If a board certified radiologist with pediatric experience, or a pediatric radiologist will be performing and interpreting the study

"Image Gently has developed the Pause and Pulse campaign in part as follow-up to the public meeting held by the U.S. Food and Drug Administration. Like the FDA, we believe that there is an opportunity to promote radiation protection in fluoroscopy in children. Fluoroscopy in children is a commonly performed study and there is a significant opportunity to decrease radiation dose for children, while still performing a diagnostic exam. These materials raise awareness and provide evidence based educational materials to work toward this goal," said Marilyn Goske, MD, chair of the Alliance, past president of the SPR, and Silverman Chair for Radiology Education at Cincinnati Children's Medical Center.

"Our goal is to ensure that every facility uses appropriate dose reduction techniques when performing imaging and interventional procedures in children," said James Temme, M.P.A., R.T.(R)(QM), FASRT, president of the American Society of Radiologic Technologists. "The technique must always be matched to the size and needs of the child."

The Image Gently site (www.imagegently.org) also contains the latest research and educational materials to aid radiologists, radiologic technologists, medical physicists, and other imaging stakeholders in determining the appropriate techniques to be used in the imaging of children and how the radiation received from these exams may affect pediatric patients over time.

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Health care providers are urged to visit the Image Gently Web site (www.imagegently.org) and pledge to do their part to "child-size" the radiation dose used in children's imaging.

To speak with a representative from the Image Gently campaign, please contact Shawn Farley at 703-648-8936/PR@acr.org or Ceela McElveny at 800-444-2778 begin_of_the_skype_highlighting 800-444-2778 end_of_the_skype_highlighting, Ext. 1239/cmcelveny@asrt.org

New IEEE-USA president looks to advance US innovation and entrepreneurship

philosoft@live.com (forhad) — Sun, 13 Feb 2011 01:13:00 -0800

New IEEE-USA President Ron Jensen has identified advancing U.S. innovation, entrepreneurship and competitiveness as his priorities for 2011.
"Engineers and technologists are innovators and job creators," Jensen said. "The more technology specialists we unleash in the workforce, the better our opportunity to revitalize the U.S. economy. Our nation's ability to innovate new products and services will help us to compete globally and create jobs in the United States."
Jensen, who became IEEE-USA president on 1 January, succeeds Evelyn Hirt. Jim Howard is president-elect.
Jensen is encouraged by the recently announced public/private partnership, Startup America, and its potential to increase the number of new businesses that have high-growth, high job-creating potential. See http://www.whitehouse.gov/issues/startup-america.
IEEE-USA supports and promotes high-tech entrepreneurship through programs like its Entrepreneurs Village, TechMatch and IEEE Alliance of Consultants Networks. In 2009, IEEE-USA entered into a partnership with the Small Business Administration to assist high-tech entrepreneurs starting new ventures. Federal and state resources are available at http://www.ieeeusa.org/careers/entrepreneurs/resources.asp#SBA.
"I am especially interested in understanding how we can help our members become more innovative, entrepreneurial and competitive in the global economy," Jensen said. "We have to understand what our members' careers will be like 5 to 10 years from now and support their adjustment to that environment."
IEEE-USA will also work with other science and engineering organizations to encourage Congress to fund the America COMPETES Reauthorization Act of 2010. The legislation, which was signed into law in December, authorizes federal investment in science, engineering, innovation, technology and competitiveness. Its goal is to help the United States maintain its world technology leadership and to create jobs.

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Meet the New IEEE-USA President Ronald G. Jensen enjoyed a 40-year career with IBM. He held positions in semiconductor development and applications, chip development, system design, systems architecture, management and project management. He assisted in the development of several IBM families of computers and servers, and retired in 2009 as a chief engineering manager.
Jensen's professional interests range from systems architecture and embedded systems to technical education, management and strategic planning, to the use of the Internet, collaboration tools and social networking to build a professional environment.
Jensen became a student IEEE member in 1972, a member three years later and a senior member in 1999. He also holds membership in Eta Kappa Nu, the electrical and computer engineering honor society, and the Project Management Institute.
Jensen has held numerous IEEE volunteer leadership positions. Highlights include, among others, serving on the IEEE Board of Directors as Region 4 director in 2005-06, and chairing the IEEE Strategic Planning Committee in 2007-08. He is a member of the IEEE Computer Society, Technology Management Council and Women in Engineering affinity group. He was honored with an IEEE Third Millennium Medal in 2000.
Jensen and his wife, Marlene, live on Lake Zumbro outside of Rochester, Minn. They have two grown sons, Joel and Ryan, and three grandchildren, Emily, Lily and Dane.
For more on Jensen, check out the December issue of IEEE-USA In Action: http://www.nxtbook.com/nxtbooks/ieeeusa/ieeeusa_1210/#/22/OnePage.
IEEE-USA advances the public good and promotes the careers and public policy interests of 210,000 engineering, computing and technology professionals who are U.S. members of IEEE. http://www.ieeeusa.org

Nanoparticles May Enhance Circulating Tumor Cell Detection

philosoft@live.com (forhad) — Sat, 12 Feb 2011 04:16:00 -0800

ATLANTA – Tiny gold particles can help doctors detect tumor cells circulating in the blood of patients with head and neck cancer, researchers at Emory and Georgia Tech have found.

The detection of circulating tumor cells (CTCs) is an emerging technique that can allow oncologists to monitor patients with cancer for metastasis or to evaluate the progress of their treatment. The gold particles, which are embedded with dyes allowing their detection by laser spectroscopy, could enhance this technique’s specificity by reducing the number of false positives.

The results are published online in the journal Cancer Research.

Gold-based nanoparticles can detect circulating tumor cells. Download/view larger image.

One challenge with detecting CTCs is separating out signals from white blood cells, which are similarly sized as tumor cells and can stick to the same antibodies normally used to identify tumor cells. Commercially available devices trap CTCs using antibody-coated magnetic beads, and technicians must stain the trapped cells with several antibodies to avoid falsely identifying white blood cells as tumor cells.

Emory and Georgia Tech researchers show that polymer-coated and dye-studded gold particles, directly linked to a growth factor peptide rather than an antibody, can detect circulating tumor cells in the blood of patients with head and neck cancer.

“The key technological advance here is our finding that polymer-coated gold nanoparticles that are conjugated with low molecular weight peptides such as EGF are much less sticky than particles conjugated to whole antibodies,” says Shuming Nie, PhD, a professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. “This effect has led to a major improvement in discriminating tumor cells from non-tumor cells in the blood.”

The particles are linked to EGF (epithelial growth factor), whose counterpart EGFR (epithelial growth factor receptor) is over-produced on the surfaces of several types of tumor cells.

Upon laser illumination, the particles display a sharp fingerprint-like pattern that is specific to the dye, because the gold enhances the signal coming from the dyes. This suggests that several types of nanoparticles could be combined to gain more information about the growth characteristics of the tumor cells. In addition, measuring CTC levels may be sensitive enough to distinguish patients with localized disease from those with metastatic disease.

“Nanoparticles could be instrumental in modifying the process so that circulating tumor cells can be detected without separating the tumor cells from normal blood cells,” Nie says. “We’ve demonstrated that one tumor cell out of approximately one to ten million normal cells can be detected this way.”

In collaboration with oncologists at Winship Cancer Institute, researchers used nanoparticles to test for CTCs in blood samples from 19 patients with head and neck cancer. Of these patients, 17 had positive signals for CTCs in their blood. The two with low signals were verified to have no circulating cells by a different technique.

“Although the results have not been compared or validated with current CTC detection methods, our ‘one-tube’ SERS technology could be faster and lower in costs than other detection methods,” says Dong Moon Shin, MD, professor of hematology and oncology and otolaryngology, associate director of academic development for Winship Cancer Institute and director of the Winship Cancer Institute Chemoprevention Program. “We need to validate this pilot study by continuing with larger groups of patients and comparing with other tests.”

http://cancerres.aacrjournals.org/content/early/2011/01/03/0008-5472.CAN-10-3069.abstract

Writer: Quinn Eastman

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The Robert W. Woodruff Health Sciences Center of Emory University is an academic health science and service center focusing on teaching, research, health care and public service.

Learn more about Emory’s health sciences:
Blog: http://emoryhealthblog.com
Twitter: @emoryhealthsci
Web: http://emoryhealthsciences.org

In online dating, blacks more open to romancing whites than vice versa

philosoft@live.com (forhad) — Sat, 12 Feb 2011 04:15:00 -0800

New research from the University of California, Berkeley, suggests that when it comes to dating, cyberspace is as segregated as the real world. Data gathered from more than 1 million profiles of singles looking for love online show that whites overwhelmingly prefer to date members of their own race, while blacks, especially men, are far more likely to cross the race barrier in hopes of being struck by Cupid’s arrow.

UC Berkeley researchers analyzed the racial preferences and online activity of people from the United States who subscribed between 2009 and 2010 to a major Internet dating service. In their profiles, the online daters stated a racial preference. Some said they preferred to date only within their race, others preferred someone outside their race, and yet others said they were open to dating someone of any race.
Researchers were then able to compare the online daters’ stated preferences with whom they actually contacted for a date, and they found profound differences between blacks and whites.
“Those who said they were indifferent to the race of a partner were most likely to be young, male and black,” said Gerald Mendelsohn, a UC Berkeley psychologist, professor of graduate studies and lead author of the study, which will soon be submitted for publication.
Overall, he said, “Whites more than blacks, women more than men and old more than young participants stated a preference for a partner of the same race,”
The reluctance of whites to contact blacks was true even for those who claimed they were indifferent to race. More than 80 percent of the whites contacted whites and fewer than 5 percent of them contacted blacks, a disparity that held for young as well as for older participants.
“Were they hypocritical? Alert to the realities of the social world? Striving for political correctness? Attempting an optimizing strategy of self-presentation? Our data do not permit us to choose among those alternatives,” the study authors wrote.
The study’s coauthors are Lindsay Shaw Taylor, a postdoctoral researcher at UC Berkeley; Andrew T. Fiore, a graduate of the UC Berkeley School of Information who is currently a visiting assistant professor at Michigan State University and Coye Cheshire, an assistant professor in the School of Information.
An estimated one in five Americans has used an online dating service such as eHarmony or Match.com, and a growing number of urbanites are finding romance via Facebook and other social networking sites. The percentage of couples who have met online is now nearly equal to that of pairs who met through friends or family, according to the researchers.
“As the use of online dating services grows, people whose paths never would have crossed offline now regularly meet and have meaningful exchanges in the virtual world,” the UC Berkeley study says.
The last 40 years have seen a dramatic shift in attitudes in America toward black-white intermarriage – from three to one opposed to three to one in favor, said Mendelsohn. Yet, 2000 U.S. Census data shows that black-white couples represent just 1 percent of American marriages, he said.
The main findings of this study parallel the census data on marriage in that blacks are more likely than whites to be in interracial marriages, and that couples in which the husband is black and the wife is white are more common than those in which the husband is white and the wife is black, according to Mendelsohn.
“One theory is that blacks are acting like other minority populations in the history of this country,” Mendelsohn said. “They are interested in moving up in the power structure, and one way you do that is through intermarriage with the dominant group.”
According to the study, more than 80 percent of the online dating contacts initiated by whites were to other whites, with only 3 percent going to blacks. This trend held for both men and women, young and old. Although black participants initiated contact to members of their own race more than to whites, they were ten times more likely to contact whites than vice versa, according the the study.
The researchers also tracked the rates of reciprocation among the pool of online daters, looking at how they responded once they received a message from an interested potential partner. Again, white men and women were most likely to respond to members of their own race, and only 5 percent of their responses went to blacks.
A major objective of the study was to gauge how changing attitudes about interracial marriage and an increase in dating opportunities have played out in relationships between blacks and whites. Also of interest to researchers was the question of whether the Obama presidency signals that the United States has entered a post-racial era.
“It is clear that we are not yet in the post-racial era, and evidence from studies of online dating suggest that waiting for its arrival will take some patience,” the study concludes.

By Yasmin Anwar, Media Relations | February 11, 2011

NASA's NPP Satellite Undergoing Flight Environmental Testing

philosoft@live.com (forhad) — Sat, 12 Feb 2011 04:09:00 -0800

GREENBELT, Md. -- The NASA National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP) climate/weather satellite is undergoing flight environmental testing at Ball Aerospace & Technologies Corp's production and test facility in Boulder, Colo.

The NPP satellite began environmental testing in November 2010 and has successfully completed vibration, acoustics and shock environments. In addition, the electromagnetic compatibility/electromagnetic interference testing was completed in January 2011. Currently the satellite is undergoing compatibility testing with the ground system and mission operations team. Later this month, the satellite will be moved into Ball’s thermal vacuum chamber where it will be subjected to extreme temperatures to simulate what the satellite will encounter in space.

NPP continues the pioneering monitoring of Earth's climate achieved by NASA's Earth Observing System suite of satellites over the past decade. The mission is also the precursor of the next generation of operational polar-orbiting environmental satellites for the National Oceanic and Atmospheric Administration (NOAA). NPP will continue the operations of NOAA’s current generation of polar-orbiting environmental satellites, which have for over 40 years protected lives and property as well as supported U.S. commerce and weather forecasts. The follow-on to NPP is the Joint Polar Satellite System (JPSS), which will be developed by NASA for NOAA.

"I am proud of the NPP team's commitment and dedication; they have kept the satellite on schedule with excellent results," stated Ken Schwer, NPP Project Manager, at NASA's Goddard Space Flight Center, Greenbelt, Md. "We are confident that we will deliver an excellent satellite for our October 25, 2011, launch date."

Throughout the satellite test campaign, NPP has worked closely with the JPSS program to ensure the compatibility and readiness of the JPSS ground and data systems to support the NPP on-orbit mission. In April 2011, the entire ground and data systems will undergo rigorous end-to-end testing to verify requirements and prepare for launch.

NPP just completed a several month review process with a review team that independently checked to ensure all aspects of the mission are on track for launch. The successful results of the review were presented to NASA Headquarters, Washington, in January 2011 where officials from NASA's Science Mission Directorate approved NPP's plan, budget, schedule, and success criteria for achieving the October 25, 2011, launch and on-orbit mission.

The five-instrument suite includes: the Visible/Infrared Imager Radiometer Suite (VIIRS); the Cross-track Infrared Sounder (CrIS); the Clouds and the Earth Radiant Energy System (CERES); the Advanced Technology Microwave Sounder (ATMS); and the Ozone Mapping and Profiler Suite (OMPS). NPP's advanced ultraviolet, visible, infrared, and microwave imagers and sounders will provide continuity of climate observations and enhance weather forecasting capabilities for the nation’s civil and military users of satellite data.

NASA's Goddard Space Flight Center manages the NPP mission on behalf of the Earth Science Division of the Science Mission Directorate at NASA Headquarters. NOAA will provide operational support for the mission.

For information about NPP and NASA agency programs on the Web, visit:
http://npp.gsfc.nasa.gov
www.nasa.gov

For information about NOAA's Satellite and Information Services, visit:
http://www.nesdis.noaa.gov

Goddard Release No. 11-012

Cynthia M. O’Carroll
Goddard Space Flight Center, Md.
240-684-0821 begin_of_the_skype_highlighting 240-684-0821 end_of_the_skype_highlighting
Cynthia.M.Ocarroll@nasa.gov

Web experts ask scientists to use the Web to improve understanding, sharing of their data in science

philosoft@live.com (forhad) — Sat, 12 Feb 2011 04:08:00 -0800

Troy, N.Y. – Peter Fox and James Hendler of Rensselaer Polytechnic Institute are calling for scientists to take a few tips from the users of the World Wide Web when presenting their data to the public and other scientists in the Feb. 11 issue of Science magazine. Fox and Hendler, both professors within the Tetherless World Research Constellation at Rensselaer, outline a new vision for the visualization of scientific data in a perspective piece titled "Changing the Equation on Scientific Data Visualization."
As the researchers explain, visualizations provide a means to enable the understanding of complex data. The problem with the current use of visualization in the scientific community, according to Fox and Hendler, is that when visualizations are actually included by scientists, they are often an end product of research used to simply illustrate the results and are inconsistently incorporated into the entire scientific process. Their visualizations are also static and cannot be easily updated or modified when new information arises.
And as scientists create more and more data with more powerful computing systems, their ability to develop useful visualizations of that data will become more time consuming and expensive with the traditional approaches.
Fox and Hendler ask the scientific community to take some important lessons from the Web.
"…visualizations on the Web are becoming increasingly more sophisticated and interactive," they write. At the same time, those Web-based visualization are also inexpensive and easy to use, according to Hendler and Fox.
Simple Web-based visualization tool kits allow users to easily create maps, charts, graphs, word clouds, and other custom visualizations at little to no cost and with a few clicks of a mouse. In addition, Web links and RSS feeds allow visualizations on the Web to be updated with little to no involvement from the original developer of the visualization, greatly reducing the time and cost of the effort, but also keeping it dynamic.
"Visualizations are absolutely critical to our ability to process complex data and to build better intuitions as to what is happening around us," the researchers write. They use the example of an online weather report. With such visualizations, Web users can click on their area for a forecast or watch videos specific to their region. Without these visualizations, no one but a trained meteorologist would be able to make sense of the mess of raw data behind those pretty maps and graphical snow clouds.
In addition to the ease of using and developing visualization on the Web, visualizations on the Web can also be easily modified, updated, customized, and recreated by other users thanks to the use of Uniform Resource Identifiers. This "linking" of data is a key feature of the new vision that Fox and Hendler outline. It is of particular importance when dealing with what they refer to as "big science" on topics such as climate change that involves data that ranges from distinct fields like biology to geology.
"The challenge is that many of the major scientific problems facing our world are becoming critically linked to the interdependence and interrelatedness of data from multiple instruments, fields, and sources," they write.
Fox and Hendler urge scientists involved in such vital scientific projects to take some tips from large Web companies like Google and Facebook, and even massive online communities such as World of Warcraft. These large companies use new data integration approach such as NoSQL, "big data," and scalable linked data to rapidly expand and maintain their capabilities. These new capabilities provide easy-to-use, low-end tools to generate visualizations and scalable tools for curating very large visualization projects that scientists can model their own visualization after, according to Fox and Hendler.

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For more information on the research of Fox and Hendler as well as the Tetherless World Research Constellation go to http://tw.rpi.edu/.

Medical College of Georgia : Blood pressure response to daily stress provides clues for better hypertension treatment

philosoft@live.com (forhad) — Thu, 14 Aug 2008 09:05:00 -0700

How the body regulates blood pressure in response to daily stress is the focus of a study geared toward helping people whose pressure is out of control.

“Research shows that two-thirds of patients’ high blood pressure is not controlled despite the best efforts of their doctors. That is terrible,” says Dr. Gregory Harshfield, director of the Georgia Prevention Institute at the Medical College of Georgia.

“We are trying to identify the mechanisms through which blood pressure is regulated under normal everyday conditions – which is what stress is – and take that information back to the clinic to better determine what sort of therapy is going to be most effective at treating your blood pressure or your grandfather’s.”

More than a dozen researchers have teamed up to do parallel studies in animal models and young adults to learn more about what factors like genes, stress and obesity contribute, their synergy and novel ways to control them.

“This research will give us information that allows us to identify what treatment is going to be effective in what individual by genotype, by obesity and other factors. What kind of treatment is going to be effective at keeping an individual’s blood pressure down or maybe preventing it from ever getting high,” says Dr. Harshfield, principal investigator on the $10.6 million Program Project grant renewal from the National Institutes of Health’s National Heart, Lung and Blood Institute. 72 million Americans – 1 in 3 – are hypertensive, according to the NHLBI.

Studies will explore fundamentals such as why about 30 percent of young healthy blacks and 15 percent of whites can’t effectively excrete sodium, a problem that raises blood pressure by increasing the body’s fluid volume. “We think there is a defect in their kidneys, in the normal mechanisms that allow them to excrete salt,” said Dr. David Pollock, renal physiologist at MCG’s Vascular Biology Center and a program project leader. “When blood pressure goes up due to stress, their kidneys ought to get rid of more salt so their blood pressure will come down, and they don’t.”

Dr. Harshfield’s studies identified this impaired stress-induced sodium natriuresis. He believes it’s also a primary reason blood pressure remains elevated at night in some blacks, rather than dipping as it should, which keeps stressing the cardiovascular system.

Using a rat bred to be salt-sensitive, the researchers are working to identify more about the genetics of impaired sodium-handling. “We have animal model data that says the endothelin system normally functions to help your kidneys get rid of salt,” says Dr. Pollock. His studies have shown the kidney’s endothelin B receptor plays a critical role in promoting excretion of acute and chronic salt loads by activating the precursor to nitric oxide, a powerful dilator of blood vessels. In the new studies, he’ll control the rats’ diet and see whether stress slows down sodium excretion. Preliminary evidence suggests it does. He’ll also give the rats an endothelin antagonist, which blocks this hormone, and see if sodium excretion improves. He’ll also see how a high-fat diet and obesity alter the equation.

Meanwhile, for about a week, young study participants with impaired sodium excretion will take a drug to block the powerful blood vessel constrictor, angiotensin. “From our point of view, angiotensin promotes sodium retention directly and it also increases aldosterone, another hormone which promotes sodium retention,” Dr. Harshfield says. The researchers chose to study endothelin and angiotensin because they believe they work together. To explore the genetics, they’ll also look at young adults with a different version of the angiotensin receptor gene that they believe exacerbates sodium-handling problems. MCG researchers identified this genetic variation in people who retain sodium; blocking the receptor gene will provide more evidence about the importance of angiotensin, says Dr. Harshfield.

They’ll mimic the way many people work – an hour of stress, a few minutes of relief, then back to stress – by getting the young people to play competitive video games, then measuring how gene blockers affect sodium excretion. “Ultimately, you want to know how to treat people with this variation,” Dr. Harshfield says. “There is still a need to figure out why some people respond to some therapies and other don’t,” adds Dr. Pollock. “That is not our specific question but these studies will help address that. We have to identify what is it about different individuals that make them react more to stress, makes them retain more salt.”

Obesity, which is associated with increased blood pressure reactivity, is probably a differentiator, Dr. Pollock says. Fat cells actually secrete angiotensin, which gets into the bloodstream. “We are arguing in our study that you might want to treat patients differently depending on whether or not they are obese. The angiotensin receptor blocker may be more effective in obese individuals who have angiotensin falling out into their bloodstream,” says Dr. Harshfield. Consequently they’ll also compare the effectiveness of the blocker in obese and normal-weight individuals with impaired sodium excretion.

Another project is exploring the role of oxidative stress, or reactive oxygen species, in raising blood pressure. In an animal model genetically predisposed to salt-sensitive hypertension, Dr. Jennifer Pollock, biochemist in MCG’s Vascular Biology Center and a program project leader, has shown a prolonged recovery to normal blood pressure following stress. She’s also found oxidative stress levels go up with stress. Oxidative stress, or reactive oxygen species, helps make normal chemical reactions in the body but, in excess, can cause havoc. In fact, when she gives the rats an antioxidant before a stressor, blood pressure doesn’t rise as high and recovery is more normal. “We also found out that endothelin actually is the stimulus for increasing reactive oxygen species,” Dr. Jennifer Pollock says. “When we gave the rats a specific type of endothelin blocker, that also blocked the increase in oxidative stress, blocked the blood pressure increase and improved recovery.”

Now they want to know the specific sources of the reactive oxygen species. Earlier work by Dr. Frank Treiber, MCG vice president for research and principal investigator on the original Program Project grant in 2002, has shown increased blood pressure reactivity in children who are obese and/or have low socioeconomic status.

Looking at how obesity weighs in, Dr. Jennifer Pollock also is putting the rats on high-fat diets. It’s known these rats become hypertensive on a high-salt or high-fat diet and they’ve found that, as with people, fat also increases blood pressure reactivity. Now she is going to find out how.

Another animal model is providing insight into the impact of early life stressors or low socioeconomic status on cardiovascular disease. Research again found that, as with people, these animals have normal blood pressure as pups. But as stressed adult rats, they have higher pressure increases and a delayed recovery unless they are missing an endothelin receptor gene. “It cures it,” says Dr. Jennifer Pollock. “This early life stressor is being mediated through the endothelin pathway.” Her postdoctoral fellow, Dr. Analia Loria, found these early life stressor models also have more constrictive blood vessels because they are more sensitive to angiotensin. New studies will further test the endothelin connection and see if a high-fat diet makes things worse by increasing oxidative stress.

Wildlife biologists have found naturally occurring models. Rat pups whose mother builds a nest far from a food source and so must be gone foraging several hours each day, are more anxious. Neurobiologists have shown animals separated from their moms for long periods can’t run through mazes well and tend to back off in competition for food, Dr. Jennifer Pollock says. “We took that to mean their blood pressure could also be hyper reactive. Sure enough, that is what we found.”

“This has a lot of implications for earlier detection of risk-increasing environmental exposures and what you can do about it,” says Dr. Treiber, a clinical child psychologist and program project leader. “If you can’t alter the environment that quickly in life, you know now where they are headed and maybe you can preempt it pharmacogenetically.”

In the diverse group of some 600 young people he’s been following for 17 years, Dr. Treiber has found that, as with the general population, some already are obese and/or hypertensive at the average age of 25. He’ll continue to follow and annually assess them over the next five years in an effort to better understand how stress contributes to hypertension. “What we are doing is looking at chronic environmental stress in combination with some bad candidate genes that are stress activated,” says Dr. Treiber. He’s thinking that, as with rats, genetic predisposition and stress can doom people with normal pressures to hypertension. They’ll look at blood pressure reactivity, recovery, sodium secretion, measure the footprints left by oxidative stress and the levels of the stress hormone cortisol. They’ll look at early indicators of cardiovascular disease, such as enlargement of the pumping chamber of the heart and signs of carotid artery disease. “If you have a tendency to have high blood pressure or if you are obese, we can see the inner layer of the carotid getting thicker than normal people your age,” says Dr. Gaston Kapuku, cardiologist and cardiovascular researcher at the Georgia Prevention Institute and a project core leader.

America’s current obesity and type 2 diabetes epidemic also has them looking at insulin, glucose and cholesterol levels and whether fat exacerbates all the factors they are following, which they believe it does.

One reason the Georgia Prevention Institute was founded was to identify risk factors for cardiovascular disease, says Dr. Harshfield. In his 10 years at the institute, the agenda has shifted from looking at precursor development of adult hypertension to identifying mechanisms causing pediatric hypertension, a disease that didn’t exist when most hypertension textbooks were written, he says.

“Our ultimate goal, of course, is prevention,” he says. “But when we can’t do that, we want to give physicians ways to determine precisely the cause or causes of your hypertension and optimal ways to target your disease.”

The MCG Department of Biostatistics, chaired by Dr. Varghese George, is designing the studies for the Program Project grant to ensure scientifically validity and managing data for all the program projects.

Oceans on the Precipice: Scripps Scientist Warns of Mass Extinctions and 'Rise of Slime'

philosoft@live.com (forhad) — Thu, 14 Aug 2008 09:03:00 -0700

Threats to marine ecosystems from overfishing, pollution and climate change must be addressed to halt downward trends

Scripps Institution of Oceanography/UC San Diego

Human activities are cumulatively driving the health of the world's oceans down a rapid spiral, and only prompt and wholesale changes will slow or perhaps ultimately reverse the catastrophic problems they are facing.

Such is the prognosis of Jeremy Jackson, a professor of oceanography at Scripps Institution of Oceanography at UC San Diego, in a bold new assessment of the oceans and their ecological health. Publishing his study in the online early edition of the Proceedings of the National Academy of Sciences (PNAS), Jackson believes that human impacts are laying the groundwork for mass extinctions in the oceans on par with vast ecological upheavals of the past.

Jeremy Jackson, Scripps Professor of Oceanography

He cites the synergistic effects of habitat destruction, overfishing, ocean warming, increased acidification and massive nutrient runoff as culprits in a grand transformation of once complex ocean ecosystems. Areas that had featured intricate marine food webs with large animals are being converted into simplistic ecosystems dominated by microbes, toxic algal blooms, jellyfish and disease.

Jackson, director of the Scripps Center for Marine Biodiversity and Conservation, has tagged the ongoing transformation as "the rise of slime." The new paper, "Ecological extinction and evolution in the brave new ocean," is a result of Jackson's presentation last December at a biodiversity and extinction colloquium convened by the National Academy of Sciences.

"The purpose of the talk and the paper is to make clear just how dire the situation is and how rapidly things are getting worse," said Jackson. "It's a lot like the issue of climate change that we had ignored for so long. If anything, the situation in the oceans could be worse because we are so close to the precipice in many ways."

In the assessment, Jackson reviews and synthesizes a range of research studies on marine ecosystem health, and in particular key studies conducted since a seminal 2001 study he led analyzing the impacts of historical overfishing. The new study includes overfishing, but expands to include threats from areas such as nutrient runoff that lead to so-called "dead zones" of low oxygen. He also incorporates increases in ocean warming and acidification resulting from greenhouse gas emissions.

Jackson describes the potently destructive effects when forces combine to degrade ocean health. For example, climate change can exacerbate stresses on the marine environment already brought by overfishing and pollution.

"All of the different kinds of data and methods of analysis point in the same direction of drastic and increasingly rapid degradation of marine ecosystems," Jackson writes in the paper.

During a recent research expedition to Kiritimati, or Christmas Island, Jeremy Jackson and other researchers documented a coral reef overtaken by algae, featuring murky waters and few fish. The researchers say pollution, overfishing, warming waters or some combination of the three are to blame. Photo credit: Jennifer E. Smith

Jackson furthers his analysis by constructing a chart of marine ecosystems and their "endangered" status. Coral reefs, Jackson's primary area of research, are "critically endangered" and among the most threatened ecosystems; also critically endangered are estuaries and coastal seas, threatened by overfishing and runoff; continental shelves are "endangered" due to, among other things, losses of fishes and sharks; and the open ocean ecosystem is listed as "threatened" mainly through losses at the hands of overfishing.

"Just as we say that leatherback turtles are critically endangered, I looked at entire ecosystems as if they were a species," said Jackson. "The reality is that if we want to have coral reefs in the future, we're going to have to behave that way and recognize the magnitude of the response that's necessary to achieve it."

To stop the degradation of the oceans, Jackson identifies overexploitation, pollution and climate change as the three main "drivers" that must be addressed.

"The challenges of bringing these threats under control are enormously complex and will require fundamental changes in fisheries, agricultural practices and the ways we obtain energy for everything we do," he writes.

"So it's not a happy picture and the only way to deal with it is in segments; the only way to keep one's sanity and try to achieve real success is to carve out sectors of the problem that can be addressed in effective terms and get on it as quickly as possible."

The research described in the paper was supported by the William E. and Mary B. Ritter Chair of Scripps Institution of Oceanography.

# # #

Note to broadcast and cable producers: UC San Diego provides an on-campus satellite uplink facility for live or pre-recorded television interviews. Please phone or e-mail the media contact listed above to arrange an interview.

Scripps Institution of Oceanography, at UC San Diego, is one of the oldest, largest and most important centers for global science research and graduate training in the world. The National Research Council has ranked Scripps first in faculty quality among oceanography programs nationwide. Now in its second century of discovery, the scientific scope of the institution has grown to include biological, physical, chemical, geological, geophysical and atmospheric studies of the earth as a system. Hundreds of research programs covering a wide range of scientific areas are under way today in 65 countries. The institution has a staff of about 1,300, and annual expenditures of approximately $155 million from federal, state and private sources. Scripps operates one of the largest U.S. academic fleets with four oceanographic research ships and one research platform for worldwide exploration.

The Hebrew University of Jerusalem : archaeological excavations uncover Roman temple in Zippori (Sepphoris)

philosoft@live.com (forhad) — Thu, 14 Aug 2008 08:57:00 -0700

Findings show signs of mixed city of Jews, pagans and Christians

View of the remnants of the podium, the temple's façade and some steps. The long wall in the background belongs to the church whose foundations were built on the remains...

Ruins of a Roman temple from the second century CE have recently been unearthed in the Zippori National Park in Israel. Above the temple are foundations of a church from the Byzantine period. The excavations, which were undertaken by the Noam Shudofsky Zippori Expedition led by of Prof. Zeev Weiss of the Institute of Archaeology at the Hebrew University of Jerusalem, shed light on the multi-cultural society of ancient Zippori.

The discovery indicated that Zippori, the Jewish capital of the Galilee during the Roman period, had a significant pagan population which built a temple in the heart of the city center. The central location of the temple which is positioned within a walled courtyard and its architectural relation to the surrounding buildings enhance our knowledge regarding the planning of Zippori in the Roman era.

The building of the church on the foundation of the temple testifies to the preservation of the sacred section of the city over time. This new finding demonstrates not only the religious life, culture and society in Roman and Byzantine Zippori, but also that this was a city in which Jews, pagans and later Christians lived together and developed their hometown with various buildings.

The newly discovered temple is located south of the decumanus - colonnaded street - which ran from east to west and was the main thoroughfare in the city during the Roman through Byzantine period. The temple, measuring approximately 24 by 12 meters, was built with a decorated façade facing the street. The temple's walls were plundered in ancient times and only its foundations remain.

No evidence has been found that reveals the nature of the temple's rituals, but some coins dating from the time of Antoninus Pius, minted in Diocaesarea (Zippori), depict a temple to the Roman gods Zeus and Tyche. The temple ceased to function at an unknown date, and a large church, the remains of which were uncovered by the Hebrew University excavation team in previous seasons, was built over it in the Byzantine period.

North of the decumanus, opposite the temple, a monumental building was partially excavated this summer. Its role is still unclear, although its nature and size indicate that it was an important building. A courtyard with a well-preserved stone pavement of smooth rectangular slabs executed in high quality was uncovered in the center of the building, upon which were found a pile of collapsed columns and capitals - probably as a result of an earthquake. The decoration on these architectural elements was executed in stucco. Beyond a row of columns, an adjacent aisle and additional rooms were discovered. Two of them were decorated with colorful, geometrical mosaics.

University of Exeter : New evidence implicates humans in prehistoric animal extinctions

philosoft@live.com (forhad) — Thu, 14 Aug 2008 08:55:00 -0700

Protemnodon skull from cave at Mt. Cripps, northwest Tasmania.

Research led by UK and Australian scientists sheds new light on the role that our ancestors played in the extinction of Australia's prehistoric animals. The study, published this week in the journal Proceedings of the National Academy of Sciences of the USA, provides the first evidence that Tasmania's giant kangaroos and marsupial 'rhinos' and 'leopards' were still roaming the island when humans first arrived. The findings suggest that the mass extinction of Tasmania's large prehistoric animals was the result of human hunting, and not climate change as previously believed.

Scientists have long argued over the reasons behind the worldwide mass extinctions that took place towards the end of the last ice age. The main culprits are generally thought to be climate change or some form of human impact. People only arrived in Tasmania around 43,000 years ago, when the island became temporarily connected by a land bridge to mainland Australia. None of Tasmania's giant animals, known as 'megafauna' were known to have survived until this time. This appeared to clear humans of any involvement in the disappearance of the island's large megafauna.

This new international study reports the discovery of giant kangaroos surviving in Tasmania until people arrived, placing humans back on the list of likely culprits for the subsequent extinction of the megafauna.

Palorchestes azael. A marsupial similar to a ground-sloth. Weight: approx 500 kg.

Using the latest radiocarbon and luminescence dating techniques, the team were able to determine the age of the fossilised remains of the megafauna more accurately than ever before. The results showed that some of these animals survived until at least 41,000 years ago—much later than previously thought and up to 2,000 years after the first human settlers arrived. As climate in Tasmania was not changing dramatically at this time, the researchers argue that this is evidence of these species being driven to extinction through over-hunting by humans.

Professor Chris Turney of the University of Exeter, lead author of the paper, said: "Ever since Charles Darwin's discovery of giant ground sloth remains in South America, debate has ensued about the cause of early extinction of the world's megafauna. Now, 150 years on from the publication of Darwin's seminal work The Origin of Species, the argument for climate change being the cause of this mass extinction has been seriously undermined. It is sad to know that our ancestors played such a major role in the extinction of these species – and sadder still when we consider that this trend continues today."

The researchers believe that the tale from Tasmania is relevant to many other parts of the world. Given Tasmania's history as an island, these findings should help to disentangle the role of humans and climate change in other island environments, such as Britain. Author Professor Tim Flannery of Macquarie University, Australia, said "Island environments offer an excellent test of competing hypotheses. They typically have a similar megafauna and climate to neighbouring continental landmasses but human arrival was often delayed."

Previous research by Professor Flannery and Professor Bert Roberts of the University of Wollongong, Australia, has shown that 90 per cent of mainland Australia's megafauna disappeared about 46,000 years ago, soon after humans first settled the continent. But humans did not reach Tasmania until a few thousand years later, when the island became connected to the mainland by a land bridge as sea levels fell during the last glaciation. "The Tasmanian results echo those on mainland Australia, putting humans squarely back in the frame as the driving force behind megafaunal extinction", said Professor Roberts.

The most recent discoveries were made serendipitously by cavers exploring a labyrinth of tunnels under the rainforest-clad Mt Cripps in north-west Tasmania. Author Craig Reid at the Queen Victoria Museum and Art Gallery in Tasmania, said "The skeletal remains provide key evidence of Tasmania's final megafauna in the dim, if not-too-distant, past."

The victims of Tasmania's first humans:

Zygomaturus trilobus. A rhino-like marsupial. Weight: approx 500 kg.
Palorchestes azael. A marsupial similar to a ground-sloth. Weight: approx 500 kg.
Metasthenurus newtonae. A large, short-faced kangaroo that browsed like an antelope. Weight: approx 150 kg.
Simosthenurus occidentalis. A smaller short-faced kangaroo. Weight: 100-130 kg
Protemnodon anak. A long-faced, long-necked kangaroo, like a long-necked browsing antelope. Weight: approx 120 kg.
Thylacoleo carnifex. A leopard-like marsupial. Weight: approx 70-100 kg.
Megalibgwilia sp. A monotreme (egg-laying mammal) similar in shape and size to the long-beaked echidna of New Guinea. Weight: approx 10 kg.

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This study was conducted by researchers at the University of Exeter (UK), University of Wollongong (Australia), Macquarie University (Australia), Queen Victoria Museum and Art Gallery (Australia), Australian National University, University of Oxford (UK), Tasmanian Museum and Art Gallery (Australia), University of Newcastle (UK), University of Strathclyde (UK), Queen's University Belfast (UK).

The research was supported by The Royal Society and the Australian Research Council.

Helmholtz Association of German Research Centres : Drinking water in Gaza Strip contaminated with high levels of nitrate

philosoft@live.com (forhad) — Thu, 14 Aug 2008 08:51:00 -0700

Manure and wastewater are polluting the water and endangering infant health

Dry sludge produced from Gaza Wastewater Treatment Plant, May 2007. There are no treatment facilities for sludge in Gaza and it is just exposed to dry in the sun before...

Gaza/Leipzig. Palestinian and German scientists have recommended to the authorities in the Gaza Strip that they take immediate measures to combat excessive nitrate levels in the drinking water. 90 per cent of their water samples were found to contain nitrate concentrations that were between two and eight times higher than the limit recommended by the World Health Organization (WHO), say the researchers from the University of Heidelberg and the Helmholtz Centre for Environmental Research (UFZ) writing in the specialist journal Science of the Total Environment. Over the long term they recommend that the best protection would be provided by quality management for groundwater resources. Groundwater is the only source of drinking water for the majority of people living in the Gaza Strip. In babies younger than six months, nitrate can lead to methaemoglobinaemia, to diarrhoea and to acidosis. The WHO therefore recommends keeping nitrate levels to 50 milligrams per litre or less. According to unpublished research, half of the 640 infants tested were already showing signs of methaemoglobinaemia. The new Palestinian-German study confirms earlier water analyses and is the first study to pinpoint a source of the contamination. With the help of isotope analyses, the researchers were able to demonstrate that the nitrate pollution can be traced back to manure used in farming and to wastewater.

One of the groundwater wells in Khan Younis area in the Gaza Strip under regular monitoring program by the research shared project between the University of Heidelberg and the Gaza...

With over 2600 people per square kilometre, the Gaza Strip is one of the most densely populated areas on earth. Because of their isolation, the inhabitants of this area between the Mediterranean, Egypt and Israel are reliant on being self-sufficient. The fields are mostly fertilized with chicken and cow dung. Artificial fertilizers account for only around a quarter of the fertilizer used. Because of the area's geology and the semi-arid climate, it is fairly easy for impurities to seep down from the surface into the aquifier system. Organic fertilizers and wastewater are the main causes of the nitrate contamination in the groundwater, followed by sewage sludge and artificial fertilizers. This was revealed by the isotope ratios of nitrogen (15N/14N) and oxygen (18O/16O) in the nitrate. Isotopes are variations of the same chemical element that have a different number of neutrons in their nuclei. 18O and 15N are stable, i.e. non-radioactive, isotopes that are heavier than "normal" oxygen (16O) or nitrogen (14N) and can therefore be measured using a mass spectrometer. "The lower 15N nitrogen isotope values in the sewage sludge indicate that the nitrate in the Gaza groundwater comes primarily from manure used as fertilizer," explains Dr Karsten Osenbrück of the UFZ. Between 2001 and 2007 the scientists took water samples from 115 municipal wells and 50 private wells on seven occasions. They measured nitrate concentrations of between 31 and 452 milligrams per litre. Only 10 of the 115 municipal wells examined were found to have a nitrate level below the WHO guideline value. The situation with the private wells was equally serious: apart from three, all the wells were found to have nitrate levels that were between five and seven times higher than the WHO recommendations.
Tilo Arnhold

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Elsevier : Towards understanding bluetongue outbreaks

philosoft@live.com (forhad) — Thu, 14 Aug 2008 08:50:00 -0700

Multi-centre sequence analysis reveals origins of economically important virus strain

Amsterdam, August 14, 2008 – A recent article published in Virology (www.elsevier.com/locate/yviro), reports the identification of a bluetongue virus strain that caused the northern European Bluetongue outbreak in 2006. Comparison of the virus strain with the sequences of other previously isolated strains showed that it originated in sub-Saharan Africa, rather than from vaccine strains or strains circulating in southern Europe.

Bluetongue (BT) disease or catarrhal fever is a non-contagious, insect borne viral disease of ruminants, mainly sheep. It is characterized by high fever, excessive salivation, swelling of the head and neck which can lead to cyanosis of the tongue (after which the disease is named). BT is caused by the bluetongue virus (BTV) and due to its economic significance BTV has been the subject of extensive molecular, genetic and structural studies. The disease has been observed in Australia, the USA, Africa, the Middle East, Asia and southern Europe. Its occurrence is seasonal in the affected countries, subsiding when temperature drop and hard frosts kill the midges that transmit the disease. It has been spreading northward since the late 90s, perhaps as a result of global warming.

In August 2006, the record temperatures experienced in northern Europe coincided with the first outbreak of BT in the Netherlands, Belgium, Luxemburg, and much of Germany. In the article Peter Mertens and 24 co-authors from six different institutes describe the sequence analysis of the full genome of this BTV strain and compare it to other BTV strains (Virology, doi:10.1016/j.virol.2008.04.028). Their results indicate that despite the high levels of nucleotide identity with other European strains, it represents a new strain introduction, originating from sub-Saharan Africa.

"Such timely and increasingly important insights into the origins of emerging viruses will lead not only to an increased understanding of how viruses like BTV spread, but also to rational vaccine development", said Barbara Sherry, one of the Editors of Virology.

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Notes to editors:
Maan, S., Maan, N.S., Ross-smith, N., Batten, C.A., Shaw, A.E., Anthony, S.J., Samuel, A.R., Darpel, K.E., Veronesi, E., Oura, C.A.L., Singh, K.P., Nomikou, K., Potgieter, A.C., Attoui, H., van Rooij, E., van Rijn, P., De Clercq, K., Vandenbussche, F., Zientara, S., Bréard, E., Sailleau, C., Beer, M., Hoffman, B., Mellor, P.S., Mertens, P.P.C., 2008. Sequence analysis of bluetongue virus serotype 8 from the Netherlands 2006 and comparison to other European strains. Virology, 377 (2), pp. 308-318.

To receive a copy of the article please contact the press office at newsroom@elsevier.com

About Virology
Launched in 1954, Virology (www.elsevier.com/locate/yviro) publishes the results of basic research in all branches of virology, including the viruses of vertebrates and invertebrates, plants, bacteria, and yeasts/fungi. The journal features articles on the nature of viruses, on the molecular biology of virus multiplication, on molecular pathogenesis, and on molecular aspects of the control and prevention of viral infections. The approaches and techniques used are expected to encompass those of many disciplines, including molecular genetics, molecular biology, biochemistry, biophysics, structural biology, cell biology, immunology, and morphology. The journal is a leading resource for current information in the field of virology.

About Elsevier
Elsevier is a world-leading publisher of scientific, technical and medical information products and services. Working in partnership with the global science and health communities, Elsevier's 7,000 employees in over 70 offices worldwide publish more than 2,000 journals and 1,900 new books per year, in addition to offering a suite of innovative electronic products, such as ScienceDirect (http://www.sciencedirect.com/), MD Consult (http://www.mdconsult.com/), Scopus (http://www.info.scopus.com/), bibliographic databases, and online reference works.

Elsevier (http://www.elsevier.com/) is a global business headquartered in Amsterdam, The Netherlands and has offices worldwide. Elsevier is part of Reed Elsevier Group plc (http://www.reedelsevier.com/), a world-leading publisher and information provider. Operating in the science and medical, legal, education and business-to-business sectors, Reed Elsevier provides high-quality and flexible information solutions to users, with increasing emphasis on the Internet as a means of delivery. Reed Elsevier's ticker symbols are REN (Euronext Amsterdam), REL (London Stock Exchange), RUK and ENL (New York Stock Exchange).

European Space Agency : ESA ground team in simulation training for GOCE launch

philosoft@live.com (forhad) — Thu, 14 Aug 2008 08:48:00 -0700


ESA mission controllers in simulation training for GOCE launch

The Mission Control Team at ESA's Space Operations Centre (ESOC) are now in intense training for the scheduled 10 September launch of GOCE, the Agency's Gravity field and steady-state Ocean Circulation Explorer.

GOCE is scheduled for lift-off at 16:21 CEST, 10 September 2008, from the Plesetsk Cosmodrome; the spacecraft arrived in Russia on 29 July on board an Antonov-124 cargo aircraft.

On 14 August, members of the Mission Control Team were on console in the Main Control Room at ESOC, Darmstadt, Germany, for a
12-hour simulation of the mission's countdown and launch phases; the simulation included practicing immediate reactions in case of any unexpected problems with the ground segment or the spacecraft.


	Keeping watch over system status during the GOCE launch simulation.

GOCE team supported by experts throughout ESOC

The overall Mission Control Team is led by Flight Operations Director Pier Paolo Emanuelli and comprises a dedicated
13-person Flight Control Team, joined by an extended team of engineers from Ground Operations, Flight Dynamics, Software Support, Computers & Network Support, and ground stations.

Additional expertise is provided from ESOC in the areas of training, documentation and facilities management.

GOCE will orbit at an exceptionally low altitude

"The GOCE mission team are receiving excellent support from our colleagues at ESOC. GOCE is a challenging mission and will orbit at an exceptionally low altitude of just 268 km, so spacecraft control is very critical. The simulations campaign is close to the end and we are fully ready to support the launch in September," said Emanuelli.


	The 14 August simulation included both the A and B sections of the GOCE Flight Control Team

To achieve its mission objectives - mapping Earth's gravity field in unprecedented detail - the slender, 5m-long satellite is designed to orbit at a low altitude because the gravitational variations are stronger closer to Earth.

The GOCE team will undergo intensive training, simulations and work-ups between now and the launch, with a strong focus on practicing for LEOP - the Launch and Early Orbit phase - the crucial first steps in GOCE's mission beginning after the satellite separates from the launcher's upper-most stage.

One highlight of today's training will be establishing and testing the voice and data communication links between ESOC in Germany and the Launch Control Centre at Plesetsk, Russia.


	The 13-person GOCE flight control team is supported by many specialists throughout ESOC.

The GOCE team conducted previous simulations in July and August, and have spent the past months defining and confirming procedures and plans covering all possible nominal and contingency situations.

Flight control team engineers have also been working intently to ensure that the ground segment - the computers and software here at ESOC - is ready to support the mission.

A full launch and LEOP rehearsal will be conducted on 5 September, just five days prior to launch.

Today's 12-hour simulation practised the countdown and launch phases of the GOCE mission.

American Psychological Association : Psychologists show new ways to deal with health challenges in space

philosoft@live.com (forhad) — Thu, 14 Aug 2008 08:46:00 -0700

Psychologists reveal groundbreaking research, technology that will help address psychosocial challenges in next 'Age of Exploration'

BOSTON—As NASA prepares to send humans back to the moon and then on to Mars, psychologists are exploring the challenges astronauts will face on missions that will be much longer and more demanding than previous space flights. Psychologists outlined these mental health challenges Thursday at the American Psychological Association's 116th Annual Convention, and introduced a new interactive computer program that will help address psychosocial challenges in space.

"Lessons learned from the past, research in extreme environments, training, conditioning, and countermeasures for psychological stress are some of the things NASA is in the process of addressing for the upcoming age of exploration," said psychologist Marc Shepanek, PhD, from the Office of the Chief Health and Medical Officer at NASA.

Psychologists said longer missions mean astronauts will be faced with immense psychological pressures as they adjust to being so far away from Earth, which could lead to depression and interpersonal conflicts. The presenters spoke at APA's first symposium to address the psychological challenges of returning to the moon and going to Mars.

Historically, astronauts have been reluctant to admit to mental or behavioral health problems for fear of being grounded. Psychologist James Carter, PhD, and his colleagues are in the process of developing a suite of interactive computer programs, dubbed the Virtual Space Station, using input from 13 veteran long-duration NASA astronauts who have flown on the International Space Station, Mir and Skylab. The system is being evaluated in a set of randomized controlled clinical trials. This interactive program will help astronauts prevent, detect, assess and manage their own psychosocial problems. They will learn how to cope with depression and how to resolve conflicts with other astronauts.

"Behavioral health problems can interfere with the success of the mission, especially on long-duration space flights like missions to the International Space Station, the moon and Mars. These self-guided software tools will provide private and immediate access to treatments even though the patient may be many miles from Earth," Carter said in prepared remarks. The Virtual Space Station has already been deployed in Antarctica.

However, as astronauts aim to explore a new planet, the one they leave behind could be foremost on their minds. They will have limited contact with their families and radio communications with Mission Control will be delayed, possibly for as long as 40 minutes. In her presentation, family sociologist Phyllis Johnson, PhD, analyzed interviews with astronauts who had spent an extended amount of time in space. The astronauts identified what they felt was the role of NASA, themselves and their families in creating a "home away from home" during their flights. "For example, they emphasized the importance of regular communication regarding work, publicity and education, all of which provide connection to Earth and helped to reduce the perception of isolation," said Johnson.

Psychologists also looked to history for guidance in future space missions. "The closest analogue to Mars exploration is the exploration of Earth," said psychologist Peter Suedfeld, PhD. "Both maritime and terrestrial explorers struck off into the unknown, often for many years at a time." Like space explorers, they had little or no communication with home, and had to devise ways of coping with unforeseen and unfamiliar hardships and dangers. Psychologists are re-examining sea and land voyagers' diaries, logs and letters for a glimpse into how these explorers dealt with boredom, rebelliousness and dissent. They said it may be best way to predict some aspects of future long-duration missions.

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Presentations: "Preparing for the Psychological Stress of Long-duration Space Missions," Marc A. Shepanek, PhD, Office of the Chief Health and Medical Officer, NASA; "Living in Space: Creating a Home Away From Home," Phyllis J. Johnson, PhD, University of British Columbia; "The Uses of History: Space Analogues Revisited," Peter Suedfeld, PhD, University of British Columbia; "Computer-based Psychosocial Support for Long-duration Spaceflights," James A. Carter, PhD, Harvard Medical School, Leonard Greenhalgh, PhD, Amos Tuck School of Business at Dartmouth College, Steven E. Locke, MD, Harvard Medical School, Jay C. Buckey, MD, Dartmouth Medical School, Mark T. Hegel, PhD, Dartmouth Medical School; Session 1111 – Symposium: To the Moon and Mars: Psychology of Long-Duration Space Exploration, 10:00 – 11:50 AM, Thursday, Aug. 14, Boston Convention and Exhibition Center, Meeting Level 2, Meeting Room 206A. Symposium Chair: Douglas A. Vakoch, PhD, SETI Institute. Discussants: Edna R. Fiedler, PhD, National Space Biomedical Research Institute, Uwe P. Gielen, PhD, St. Francis College, Walter Sipes, PhD, NASA/Johnson Space Center

Full texts of the remarks are available from the APA Public Affairs Office.

For more information/interview, please contact: Douglas Vakoch at (510) 688-0028 or by e-mail at vakoch@seti.org.

The symposium presenters can also be contacted:

Marc Shepanek, PhD – NASA Office of the Chief Health and Medical Officer; "Preparing for the Psychological Stress of Long-Duration Space Missions"; phones: (W) 202-358-2201, (C) 202-744-7541, (H) 202-244-2787; mshepanek@hq.nasa.gov

Phyllis Johnson, PhD – Univ. of British Columbia, Vancouver, Canada; "Living in Space: Creating a Home Away From Home"; phones: (W) 604-822-4300, (H) 604-687-8886, (Boston) 617-227-8600; pjohnson@interchange.ubc.ca

Peter Suedfeld, PhD – University of British Columbia, Vancouver, Canada; "Uses of History: Space Analogues Revisited"; phones: (W) 604-822-5713, (Boston) 617-227-8600; psuedfeld@psych.ubc.ca

James Carter, PhD – Harvard Medical School; "Computer-Based Psychosocial Support for Long-Duration Spaceflights"; phones (W) 617-667-1507, (C) 617-851-8913; jacarter@caregroup.harvard.edu

The American Psychological Association (APA), in Washington, DC, is the largest scientific and professional organization representing psychology in the United States and is the world's largest association of psychologists. APA's membership includes more than 148,000 researchers, educators, clinicians, consultants and students. Through its divisions in 54 subfields of psychology and affiliations with 60 state, territorial and Canadian provincial associations, APA works to advance psychology as a science, as a profession and as a means of promoting human welfare.

NASA/Goddard Space Flight Center : NASA data show some African drought linked to warmer Indian Ocean

philosoft@live.com (forhad) — Thu, 14 Aug 2008 08:44:00 -0700

A new study, co-funded by NASA, has identified a link between a warming Indian Ocean and less rainfall in eastern and southern Africa. Computer models and observations show a decline in rainfall, with implications for the region's food security.

Rainfall in eastern Africa during the rainy season, which runs from March through May, has declined about 15 percent since the 1980s, according to records from ground stations and satellites. Statistical analyses show that this decline is due to irregularities in the transport of moisture between the ocean and land, brought about by rising Indian Ocean temperatures, according to research published today in Proceedings of the National Academy of Sciences. This interdisciplinary study was organized to support U.S. Agency for International Development's Famine Early Warning Systems Network.

"The last 10 to 15 years have seen particularly dangerous declines in rainfall in sensitive ecosystems in East Africa, such as Somalia and eastern Ethiopia," said Molly Brown of NASA's Goddard Space Flight Center, Greenbelt, Md., a co-author of the study. "We wanted to know if the trend would continue or if it would start getting wetter."

To find out, the team analyzed historical seasonal rainfall data over the Indian Ocean and the eastern seaboard of Africa from 1950 to 2005. The NASA Global Precipitation Climatology Project's rainfall dataset provided a series of data covering both the land and the oceans. They found that declines in rainfall in Ethiopia, Kenya, Tanzania, Zambia, Malawi and Zimbabwe were linked to increases in rainfall over the ocean.

The team used computer models that describe the atmosphere and historical climate data to identify and validate the source of this link. Lead author Chris Funk of the University of California, Santa Barbara, and colleagues showed that the movement of moisture onshore was disrupted by increased rainfall over the ocean.

Funk and colleagues used a computer model from the National Center for Atmospheric Research to confirm their findings. The combination of evidence from models and historical data strongly suggest that human-caused warming of the Indian Ocean leads to an increase of rainfall over the ocean, which in turn adds energy to the atmosphere. Models showed that indeed, the added energy could create a weather pattern that reduces the flow of moisture onshore and bring dry air down over the African continent, reducing rainfall.

Next, the team investigated whether or not the decline in rainfall over eastern Africa would continue. Under guidance from researchers at USGS, which co-funded the study, the team looked at 11 climate models to simulate rainfall changes in the future. Ten of the 11 models agreed that though 2050, rainfall over the Indian Ocean would continue to increase – depriving Africa's eastern seaboard of rainfall.

"We can be quite certain that the decline in rainfall has been substantial and will continue to be," Funk said. "This 15 percent decrease every 20-25 years is likely to continue."

The trend toward dryer rainy seasons in eastern and southern Africa directly impacts agricultural productivity. To evaluate how potential future rainfall scenarios and shifts in agriculture could affect undernourishment, the team came up with a "food-balance indicator" model. The model considers factors such as growing-season rainfall, fertilizer, seed use, crop area and population to estimate the number of undernourished people a region can anticipate.

Continuing along a "business as usual" scenario – with current trends in declining rainfall and agricultural capacity continuing as it is currently to 2030, the team found that the number of undernourished people will increase by more than 50 percent in eastern Africa.

Still, the food-balance indicator also showed that in the face of a continuation of the current downward trend in rainfall, even modest increases in agricultural capacity could reduce the number of undernourished people by 40 percent.

"A strong commitment to agricultural development by both African nations and the international community could lead fairly quickly to a more food-secure Africa," Funk said.

ESA/Hubble Information Centre : Globular clusters tell tale of star formation in nearby galaxy metropolis

philosoft@live.com (forhad) — Thu, 14 Aug 2008 08:41:00 -0700

The NASA/ESA Hubble Space Telescope has identified thousands of more than 5 billion year-old globular clusters in the Virgo cluster of galaxies. One of the results of these discoveries led astronomers to understand more about the life and evolution of cannibal galaxies.

Globular star clusters, dense bunches of hundreds of thousands of stars, contain some of the oldest surviving stars in the Universe. A new international study of globular clusters outside our Milky Way Galaxy has found evidence that these hardy pioneers are more likely to form in dense areas, where star birth occurs at a rapid rate, instead of uniformly from galaxy to galaxy.

Astronomers used the NASA/ESA Hubble Space Telescope to identify over 11 000 globular clusters in the Virgo cluster of galaxies, most of which are more than 5 billion years old. Comprised of over 2 000 galaxies, the Virgo cluster is located about 54 million light-years away and is the nearest large galaxy cluster to Earth. Along with Virgo, the sharp vision of Hubble's Advanced Camera for Surveys (ACS) resolved the star clusters in 100 galaxies of various sizes, shapes, and brightness – even in faint, dwarf galaxies.

"It's hard to distinguish globular clusters from stars and galaxies using ground-based telescopes", explained Eric Peng of Peking University in Beijing, China, and lead author of the Hubble study.

Hubble’s “eye” is so sharp that it was able to pick out the fuzzy globular clusters from stars in our galaxy and from faraway galaxies in the background. "With Hubble we were able to identify and study about 90 percent of the globular clusters in all our observed fields. This was crucial for dwarf galaxies that have only a handful of star clusters".

The team found a bounty of globular clusters (from a few dozen to several dozen) in most of the dwarf galaxies within 3 million light-years of the cluster’s centre. This happens to be the same region where the giant elliptical galaxy Messier 87 resides. These numbers were surprisingly high considering the low masses of the dwarfs they inhabited. By contrast, dwarfs in the outskirts of the cluster had fewer globulars.

“Our study shows that the efficiency of star cluster formation depends on the environment”, said Patrick Cote of the Herzberg Institute of Astrophysics in Victoria, Canada. “Dwarf galaxies closest to Virgo's crowded centre contained more globular clusters than those farther away”.

Astronomers have long known that the giant elliptical galaxy at the cluster’s centre, Messier 87, also hosts a larger than predicted population of globular star clusters. However, the origin of so many globulars has been a long-standing mystery. Astronomers have theorised that many of the clusters may have been snatched from smaller galaxies that ventured too close to it.

“We found few or no globular clusters in galaxies within 130 000 light-years from Messier 87, suggesting the giant galaxy stripped the smaller ones of their star clusters”, Peng said. “These smaller galaxies are contributing to the buildup of Messier 87”.

Evidence of Messier 87’s galactic cannibalism comes from an analysis of the globular clusters’ composition. “In Messier 87 there are three times as many globulars deficient in heavy elements, such as iron, than globulars rich in those elements”, Peng said. “This suggests that many of these ‘metal-poor’ star clusters may have been stolen from nearby dwarf galaxies, which also contain globulars deficient in heavy elements”.

Studying globular star clusters is critical to understanding the early, intense star-forming episodes that mark galaxy formation. They are known to reside in all but the faintest of galaxies.

“Star formation near the core of Virgo is very intense and occurs in a small volume over a short amount of time”, Peng noted. “It may be more rapid and more efficient than star formation in the outskirts. The high star-formation rate may be driven by the gravitational collapse of dark matter, an invisible form of matter, which is denser and collapses sooner near the cluster's centre. Messier 87 sits at the centre of a large concentration of dark matter, and all of these globulars near the centre probably formed early in the history of the Virgo cluster.”

The smaller number of globular clusters in the dwarf galaxies sitting farther away from the centre may be due to the masses of the star clusters that formed, Peng said. “Star formation farther away from the central region was not as robust, which may have produced only less massive star clusters that dissipated over time”, he explained.

The astronomers also obtained accurate distances to 84 of the 100 galaxies in the Hubble study.

The results appeared on 1 July 2008 in The Astrophysical Journal.

Notes for editors:

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

Image credit: NASA, ESA and Eric Peng (Peking University, China)

Links:

Science paper
NASA News Release

Contacts:

Eric Peng
Peking University, Beijing, China
Tel: +86-10-6275-8629
E-mail: peng@bac.pku.edu.cn

Lars Lindberg Christensen
Hubble/ESA, Garching, Germany
Tel: +49-89-3200-6306
Cellular: +49-173-3872-621
E-mail: lars@eso.org

Donna Weaver/Ray Villard
Space Telescope Science Institute, Baltimore, USA
Tel: +1-410-338-4493/+1-410-338-4514
E-mail: dweaver@stsci.edu/villard@stsci.edu

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