One Drink Of Red Wine Or Alcohol Is Relaxing To Circulation, But Two Drinks Are Stressful

Daily Science Journal (Feb. 13, 2008) — One drink of either red wine or alcohol slightly benefits the heart and blood vessels, but the positive effects on specific biological markers disappear with two drinks, say researchers at the Peter Munk Cardiac Centre of the Toronto General Hospital.

Researchers conducted a real-time study of thirteen volunteers to determine whether a red wine with a verified high polyphenol content differs from alcohol in its effects on specific markers associated with a greater risk of high blood pressure, coronary artery disease and heart failure.

A large number of population studies have shown a protective effect of light or moderate alcohol drinking against the risk of death and the development of heart disease. Many studies have also reported specific benefits of red wine.

Population surveys found lower rates of heart disease, despite high-fat diets, in some European countries where red wine was consumed regularly. Widely known at the French paradox, this has created a huge interest in exploring if and how red wine has a protective effect against heart disease.

However, the findings of this study* showed virtually identical effects of red wine and alcohol on the specific markers tested. After one drink of either red wine or alcohol, blood vessels were more “relaxed” or dilated, which reduced the amount of work the heart had to do. But, after two drinks, the heart rate, amount of blood pumped out of the heart, and action of the sympathetic nervous system all increased. At the same time, the ability of the blood vessels to expand in response to an increase in blood flow diminished. This counteracted the beneficial effect of one drink of red wine or alcohol.

“We had anticipated that many of the effects of one ethanol drink would be enhanced by red wine. What was most surprising was how similar the effects were of red wine and ethanol. Any benefits that we found were not specific to red wine,” said Dr. John Floras, Director of Cardiology Research at the Peter Munk Cardiac Centre, and at Mount Sinai Hospital, in whose laboratory the study was performed. However, Dr. Floras cautioned this study measured the effects of these drinks on one occasion only. The effects of daily wine or alcohol intake may be quite different.

The laboratory of Dr. Floras, who holds the Canada Research Chair in Integrative Cardiovascular Biology and is a Professor of Medicine at the University of Toronto, and a Career Investigator of the Heart and Stroke Foundation, is one of the few in the world equipped to measure simultaneously a broad spectrum of factors such as blood pressure, heart rate, sympathetic nerve firing and arterial diameter.

Healthy, non-smoking adults who were not heavy drinkers or total alcohol abstainers were studied. Participants attended three separate morning sessions during which “standard” drinks of red wine, ethanol or water were administered at random, single-blind, two weeks apart. A 4-oz glass of wine (120 ml), and a 1.5-oz (44 ml) shot of spirits is considered to be one standard drink. All blood alcohol levels alcoholic were below .08, the legal limit for drivers.

The Quality Assurance Laboratory of the Liquor Control Board of Ontario selected a moderately priced pinot noir with a verified high t-resveratrol content, a polyphenol compound found in plants, including red grapes, which exhibits antioxidant properties. Alcohol or substances in alcohol such as resveratrol may improve blood vessel function and also prevent platelets in the blood from sticking together, which may reduce clot formation and the risk of heart attack or stroke.

Select study findings:

One drink of either red wine or alcohol:

* Has no effect on heart rate, blood pressure or sympathetic nerve activity, which activates the “fight or flight” reaction and generally modulates heart rate and sets the diameter of blood vessels in order to redistribute blood;
* Dilates the brachial artery.

Two drinks of either alcohol or red wine:

* Increase sympathetic nerve activity, heart rate, and the amount of blood the heart pumps out, and also blunt the ability of the brachial artery to expand further in response to blood flow.
* Increases in heart rate and sympathetic nerve activity are recognized markers for hypertension (high blood pressure), heart failure and sudden death.

“Our findings point to a slight beneficial effect of one drink – be it alcohol or red wine – on the heart and blood vessels, whereas two or more drinks would seem to turn on systems that stress the circulation. If these actions are repeated frequently because of high alcohol consumption these effects may expose individuals to a higher risk of heart attacks, stroke or chronic high blood pressure,” noted Dr. Floras, adding that the American Heart Association (AHA) does not recommend that anyone start drinking alcohol to prevent heart disease. Reducing risk can be done using other methods such as exercise and following a healthy diet.

The study entitled “Dose-related effects of red wine and alcohol on hemodynamics, sympathetic nerve activity, and arterial diameter”, was published in the February edition of the American Journal of Physiology, Heart and Circulatory Physiology. This study was supported by the Heart and Stroke Foundation of Ontario, the Canadian Institutes of Health Research, and the Canada Research Chairs Program.

Adapted from materials provided by University Health Network, via Newswise.

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Fake Malaria Drugs Made In China: Tracking Down The Threat To Global Health

Daily Science Journal (Feb. 13, 2008) — A unique collaboration between scientists, public health workers and police has led to the arrest by the Chinese authorities of alleged traders of fake anti-malarial drugs in southern China and the seizure of a large quantity of drugs. The work, involving teams from across the globe, has highlighted both the growing threat posed by fake pharmaceuticals and the complexities of tracking down those responsible for the trade.

Counterfeit artesunate anti-malarial tablet with fake 'X-52' stamp as seen under UV light. (Credit: Newton PN, Fernandez FM, Plancon A, Mildenhall DC, Green MD,et al.)

Dubbed Operation Jupiter, the investigation was coordinated by the International Criminal Police Organisation (INTERPOL), the World Health Organization's Western Pacific Regional Office, and the Wellcome Trust-University of Oxford SE Asian Tropical Medicine Research Programme, in close cooperation with Chinese authorities. Scientists from 5 other laboratories analysed the composition of the fake drugs and their packaging.

Fake anti-malarial drugs are an increasingly serious problem, particularly in South-East Asia and Africa. In countries with a large burden of malaria, such as Myanmar (Burma), the Lao PDR, Cambodia and Viet Nam, as many as half of all artesunate tablets -- one of the most effective anti-malarial drugs -- is counterfeit.

Most of the fakes examined as part of Operation Jupiter contained no artesunate, and some contained a wide range of potentially toxic wrong active ingredients. Also of grave concern was the fact that counterfeiters sometimes included dangerously small amounts of artesunate in the tablets. This may be done to foil screening tests of drug quality, but these doses are too low to be efficacious, yet high enough to contribute to malaria parasites becoming resistant to this class of drugs.

"Artesunate, as part of artemisinin-based combination therapy, is vital for malaria treatment and is one of the most effective weapons we have against this terrible scourge," says Dr Paul Newton of the Wellcome Trust-University of Oxford SE Asian Tropical Medicine Research Programme. "Those who make fake anti-malarials have killed with impunity, directly through the criminal production of a medicine lacking active ingredients and by encouraging drug resistance to spread. If malaria becomes resistant to artesunate, the effect on public health in the tropics will be catastrophic."

In addition to analysing the chemistry of the samples, researchers used a technique known as forensic palynology to study pollen contamination within the fake tablets with the aim of tracking down the likely location of manufacture. The pollen evidence suggested that at least some of the counterfeit artesunate came from southern China, and this was supported by examination of the mineral calcite, found in some of the samples.

Armed with these findings by INTERPOL, Chinese authorities arrested a suspect in China's Yunnan Province in 2006. He is alleged to have traded 240,000 blisterpacks of counterfeit artesunate, enough to "treat" almost a quarter of a million adults with a medicine with no activity against a potentially fatal disease. Whilst the Chinese authorities were able to seize 24,000 of these packs, the remainder are alleged to have been sold at crossings on the border of Yunnan and Myanmar (Burma), accounting for almost a half of all blisterpacks of artesunate sold to the region.

The work of the Jupiter group highlights the need for more to be done internationally to support countries with a high prevalence of counterfeit anti-malarials in their attempts to combat this severe but under-recognised public health problem.

"Criminal investigations and legal action are important in disrupting and inhibiting the trade in fake medicines, but to be effective these will require financial support and resources," says Dr Newton. "Forensic tools may make it easier to identify the fake drugs and allow over-stretched police forces to focus on objective leads, greatly increasing the risks to counterfeiters of being caught. However, there are very few laboratories with the resources to perform detailed forensic chemistry or pollen analysis of fakes, particularly in the countries where they are most needed."

Journal citation: Newton PN, Fernandez FM, Plancon A, Mildenhall DC, Green MD,et al. (2008) A collaborative epidemiological investigation into the criminal fake artesunate trade in South East Asia. PLoS Med 5(2): e32.

Adapted from materials provided by Wellcome Trust.

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International Space Station Crews Enter Columbus Laboratory

Daily Science Journal (Feb. 13, 2008) — The 24th shuttle flight to the International Space Station, STS-122, delivers Columbus, the European Space Agency's new laboratory. Columbus will be installed on Harmony Node 2.

European astronaut and station flight engineer Leopold Eyharts photographs the inside of the new Columbus laboratory. In the foreground is European astronaut and mission specialist Hans Schlegel. (Credit: NASA TV)

European astronaut and station flight engineer Leopold Eyharts got a look inside the new Columbus laboratory around 9 a.m. EST February 12. Official ingress is scheduled to occur at 2:55 p.m after preliminary outfitting of the new lab.

Supplies and equipment will be transferred into the European Space Agency’s Columbus laboratory. Three of the laboratory module’s five payload racks also are scheduled for relocation Feb. 12. Expedition 16 crew members Leopold Eyharts and Peggy Whitson will be the first to enter Columbus.

Later in the day, STS-122 Mission Specialists Rex Walheim and Hans Schlegel will camp out in the station’s Quest Airlock in preparation for the Feb. 13 spacewalk, scheduled for 9:35 a.m. EST.

On Feb 11, astronauts used the station’s robotic arm to connect Columbus to the orbital outpost and Walheim and Mission Specialist Stanley Love conducted the first of three scheduled STS-122 spacewalks. Among other tasks, the spacewalkers prepared the new module for its installation.

Adapted from materials provided by National Aeronautics And Space Adminstration.

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Nanosieves Save Energy In Biofuel Production

Daily Science Journal (Feb. 13, 2008) — A new type of membrane, developed by scientists of the University of Twente in The Netherlands, can stand high temperatures for a long period of time. This ‘molecular sieve’ is capable of removing water out of e.g. solvents and biofuels. It is a very energy efficient alternative to existing techniques like distillation.

The cylinder is the carrier of a hybrid membrane: a layer of about 100 nanometer thickness. The insert shows a close-up of the layer showing the organic links and pores. From the left of the tube, only water molecules leave the sieve. (Credit: Image courtesy of University of Twente)

Even after testing during 18 months, the new membranes prove to be highly effective, while having continuously been exposed to a temperature of 150 ºC. Existing ceramic and polymer membranes will last considerably shorter periods of time, when exposed to the combination of water and high temperatures. The scientists managed to do this using a new ‘hybrid’ type of material combining the best of both worlds of polymer and ceramic membranes. The result is a membrane with pores sufficiently small to let only the smallest molecules pass through.

Ceramic membranes, made of silica, degrade because they react with water and steam. In the new membrane, part of the ceramic links is therefore replaced by organic links. By doing this, water doesn’t have the chance to ‘attack’ the membranes. Manufacturing the new hybrid membranes is simpler than that of ceramic membranes, because the material is flexible and will not show cracks. What they have in common with ceramic membranes is the rapid flow: an advantage of this is that the membrane surface can be kept small.

The hybrid membranes are suitable for ‘drying’ solvents and biofuels, an application for which there is a large potential market worldwide. The main advantage of membrane technology is that it consumes far less energy than common distillation techniques.

The scientists also foresee opportunities in separating hydrogen gas from gas mixtures. This implies a broad range of applications in sustainable energy. Apart from that, the hybrid membranes are suitable for desalinating water. Using a hybrid membrane that is much smaller than the current polymer membranes, the same result can be achieved.

The results have been achieved in a close cooperation of scientists from the Inorganic Materials Science Group of the MESA+ Institute for Nanotechnology (UT), the Energy Efficiency in Industry department of ECN and the University of Amsterdam. The invention has been patented worldwide.

The article ‘Hybrid ceramic nanosieves: stabilizing nanopores with organic links’ by Hessel Castricum, Ashima Sah, Robert Kreiter, Dave Blank, Jaap Vente and André ten Elshof has been published in Chemical Communications (ChemComm) of the Royal Society of Chemistry in de UK.

Adapted from materials provided by University of Twente.

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New Technique Makes Tissues Transparent

Daily Science Journal (Feb. 13, 2008) — If humans had see-through skin like a jellyfish, spotting disease like cancer would be a snap: Just look, and see a tumor form or grow.

Diagram of chicken breast tissue (approximately 250 microns thick) with photo-refractive crystal to counteract the scattering of light and remove the distortion it creates in images. The lower diagram would show the clearest image. (Credit: Caltech Biophotonics Laboratory)

But humans, of course, are not remotely diaphanous. "The reason a person is not transparent is that their tissues are highly scattering," sending light waves careening through the tissue instead of straight through, as they would through the tissue of that jellyfish, explains Changhuei Yang of the California Institute of Technology.

This scattering, in addition to rendering all of us opaque, makes the detection of disease a much trickier issue, requiring a host of diagnostic tests and procedures. But not, perhaps, for much longer, thanks to a new optical trick developed by Yang, an assistant professor of electrical engineering and bioengineering, and his colleagues, that counteracts the scattering of light and removes the distortion it creates in images.

It is well known that light scattering in a material is not exactly the random and unpredictable process one might imagine. In fact, scattering is deterministic, which means that the path that a beam of light takes as it traverses a particular slice of tissue and bounces and rebounds off of individual cells, is entirely predictable; if you again bounce light through that same swath of cells, it will scatter in exactly the same way.

The process is even reversible; if the individual photons of light that scattered through the tissue could be collected and sent back through the tissue, they'd bounce back along the same path and converge at the original spot from which they were sent. "The process is similar to the scattering of billiard balls on a pool table. If you can precisely reverse the paths and velocities of the billiard balls, you can cause the billiard balls to reassemble themselves into a rack," Yang explains.

Yang, along with his colleagues at Caltech, École Polytechnique Fédérale de Lausanne in Switzerland, and MIT, exploited this phenomenon to offset the murky nature of our tissues.

Their technique, called turbidity suppression by optical phase conjugation (TSOPC), is surprisingly simple. The scientists used a holographic crystal to record the scattered light pattern emerging from a 0.46-mm-thick piece of chicken breast. They then holographically played the pattern back through the tissue section to recover the original light beam. "This is similar to grabbing hold of the direction of time flow and turning it around; the time-reversed photons must retrace their trajectories through the tissue," Yang says. "The task is formidable though, as this is comparable to starting with a rack of 10 to the 18th power billiard balls (or photons), scattering them around the table, and attempting to reassemble them into a rack."

"Until we did this study, it wasn't clear that the effect will be observable with biological tissues. We were pleasantly surprised that the effect was readily observable and remarkably robust," Yang says. "This study opens up numerous possibilities in the use of optical time reversal in biomedicine."

One possible use of the technique is in photodynamic therapy, in which a highly focused beam of light is aimed at cancerous cells that have absorbed cell-killing light-sensitive compounds. When the light hits the cells, the compounds are activated and destroy the cells. Photodynamic therapy is most effective in treating cancers on the skin surface. Yang's technique, however, offers a way to concentrate light onto cancer-killing compounds located more deeply within tissue.

Yang's idea is to inject strongly light-scattering particles that are coated with light-activated cancer-killing drugs into diseased tissue. Shine a beam of light into the tissue, and it would be reflected off the scattering compounds as it bounces through the tissue. Some of the scattered light would return to the source, where it could be recorded as a hologram.

This hologram would contain information about the path that the scattered light took through the tissue, and, in effect, describe the optimal path BACK toward the light-scattering molecule--and the cancer-killing compounds. Playing back the signal with a stronger burst of light will then activate the therapeutic drugs, which kill the cancer cells.

In addition, the technique could offer a way to power miniature implants buried deep within tissues. "If you take a quick survey of what is out there at present, you will see that implants are fairly large," Yang says. "For example, a pacemaker is about the size of a cell phone. Why are they so big? A large part of the reason is because they need to carry their own power sources."

The key to making smaller implants, then--say, the size of a pen tip--is to eliminate the power sources. "I think implants that carry photovoltaic receivers are particularly promising," he says. "The effect can be applied to tailor light-delivery mechanisms to efficiently channel light into tissues and onto these implants."

A study describing the process appears in the February issue of the journal Nature Photonics. Zahid Yaqoob, a postdoctoral fellow in electrical engineering at Caltech, performed most of the experiments reported in the paper. The other authors of the paper are Demetri Psaltis, professor of optics and dean of engineering, École Polytechnique Fédérale de Lausanne in Switzerland, and Michael S. Feld, a professor of physics at MIT.

Adapted from materials provided by California Institute of Technology.

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Biofuel Crops That Require Destroying Native Ecosystems Worsens Global Warming

Daily Science Journal (Feb. 12, 2008) — Turning native ecosystems into "farms" for biofuel crops causes major carbon emissions that worsen the global warming that biofuels are meant to mitigate, according to a new study by the University of Minnesota and the Nature Conservancy.

Aerial view of farmland in Indonesia. The conversion of peatlands for palm oil plantations in Indonesia ran up the greatest carbon debt, one that would require 423 years to pay off. (Credit: iStockphoto)

The carbon lost by converting rainforests, peatlands, savannas, or grasslands outweighs the carbon savings from biofuels. Such conversions for corn or sugarcane (ethanol), or palms or soybeans (biodiesel) release 17 to 420 times more carbon than the annual savings from replacing fossil fuels, the researchers said. The carbon, which is stored in the original plants and soil, is released as carbon dioxide, a process that may take decades. This "carbon debt" must be paid before the biofuels produced on the land can begin to lower greenhouse gas levels and ameliorate global warming.

The conversion of peatlands for palm oil plantations in Indonesia ran up the greatest carbon debt, one that would require 423 years to pay off. The next worst case was the production of soybeans in the Amazon, which would not "pay for itself" in renewable soy biodiesel for 319 years.

"We don't have proper incentives in place because landowners are rewarded for producing palm oil and other products but not rewarded for carbon management," said University of Minnesota Applied Economics professor Stephen Polasky, an author of the study. "This creates incentives for excessive land clearing and can result in large increases in carbon emissions.

"This research examines the conversion of land for biofuels and asks the question 'Is it worth it?'," said lead author Joe Fargione, a scientist for The Nature Conservancy. "And surprisingly, the answer is no."

Fargione began the work as a University of Minnesota postdoctoral researcher with Polasky, Regents Professor of Ecology David Tilman; he completed it after joining the Nature Conservancy. They, along with university researchers Jason Hill and Peter Hawthorne, also contributed to the work.

"If you're trying to mitigate global warming, it simply does not make sense to convert land for biofuels production," said Fargione. "All the biofuels we use now cause habitat destruction, either directly or indirectly. Global agriculture is already producing food for six billion people. Producing food-based biofuel, too, will require that still more land be converted to agriculture."

These findings coincide with observations that increased demand for ethanol corn crops in the United States is likely contributing to conversion of the Brazilian Amazon and Cerrado (tropical savanna). American farmers traditionally rotated corn crops with soybeans, but now they are planting corn every year to meet the ethanol demand and Brazilian farmers are planting more of the world's soybeans. And they're deforesting the Amazon to do it.

The researchers also found significant carbon debt in the conversion of grasslands in the United States and rainforests in Indonesia.

Researchers did note that some biofuels do not contribute to global warming because they do not require the conversion of native habitat. These include waste from agriculture and forest lands and native grasses and woody biomass grown on marginal lands unsuitable for crop production. The researchers urge that all fuels be fully evaluated for their impacts on global warming, including impacts on habitat conversion.

"Biofuels made on perennial crops grown on degraded land that is no longer useful for growing food crops may actually help us fight global warming," said Hill. "One example is ethanol made from diverse mixtures of native prairie plants. Minnesota is well poised in this respect."

"Creating some sort of incentive for carbon sequestration, or penalty for carbon emissions, from land use is vital if we are serious about addressing this problem," Polasky said.

"We will need to implement many approaches simultaneously to solve climate change. There is no silver bullet, but there are many silver BBs," said Fargione. "Some biofuels may be one silver BB, but only if produced without requiring additional land to be converted from native habitats to agriculture."

The work will be published in Science later this month and will be posted online Thursday, Feb. 7.

The work was supported by the University of Minesota's Initiative for Renewable Energy and the Environment and the National Science Foundation.

Adapted from materials provided by University of Minnesota.

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Antiretroviral Drugs May Protect Against Sexual Transmission Of HIV

Daily Science Journal (Feb. 12, 2008) — A new study in macaques suggests that antiretroviral drugs used to treat HIV could also protect people from getting the AIDS virus, especially if two drugs are taken in combination before exposure to the virus occurs.

A new study in macaques suggests that antiretroviral drugs used to treat HIV could also protect people from getting the AIDS virus, especially if two drugs are taken in combination before exposure to the virus occurs. (Credit: iStockphoto/Claire George)

The study found that macaques which were repeatedly exposed to SHIV (a virus closely related to HIV) but received antiretroviral drugs were less likely to become infected than exposed macaques that received no anti-HIV medication. The best protection was seen in macaques that had received a combination of two drugs. The study, led by José Gerardo García-Lerma and Walid Heneine from the US Centers for Disease Control and Prevention, is the culmination of a series of experiments designed to show how similar studies in humans -- some of which are planned and in progress -- can be optimally designed.

Although HIV treatment has rapidly advanced since the introduction of antiretroviral drugs in the 1990s, the absence of an effective vaccine means the virus continues to spread, infecting 2.5 million people each year. Pre-exposure prophylaxis (PrEP) -- the prevention of infection by treating people with drugs before they are exposed to the germ in question -- is often used to prevent malaria, but has not yet been shown to be effective against sexual transmission of HIV.

To simulate a common route of HIV transmission in humans, the researchers exposed the macaques to low weekly doses of SHIV that were given rectally. Five groups of macaques were all exposed to the virus in the same way, but they were given different dosages and combinations of antiretroviral drugs. Three groups received drugs daily: the first was only injected with one anti-HIV drug, emtricitabine (FTC); the second group received a daily dose of this drug by mouth in combination with an oral form of another anti-HIV drug called tenofovir; the third was injected with FTC and a high dose of tenofovir every day. A fourth group was also injected with FTC and a high dose of tenofovir, but macaques in this group were only treated shortly before and after the weekly exposures to HIV. For comparison a fifth group of macaques received no anti-HIV drugs.

The results showed that macaques from any of the four groups that received drugs were less likely to become infected than those in the fifth (control) group. All of the macaques receiving the combination of both FTC and the high dosage of tenofovir were protected from infection -- whether they were from the group that received these drugs daily, or only around the time of exposure to infection. The results suggest that higher doses and combinations of drugs worked better than single or low doses, and also that PrEP may not need to be taken every day to be effective.

The researchers also observed some risks that emphasize the need for careful design of human PrEP studies. They found some viral resistance to one of the drugs, FTC, in macaques that became infected. In addition, doses of tenofovir that resulted in maximum protection for macaques are higher than would be safe in humans.

In a related perspective article, Myron Cohen and Angela Kashuba from the University of North Carolina (Chapel Hill, NC, USA), uninvolved with the study, note that the results "highlight an exciting and potentially important use" of antiretroviral drugs to prevent sexual transmission of HIV.

Journal citation: García-Lerma JG, Otten RA, Qari SH, Jackson E, Cong M, et al. (2008) Prevention of rectal SHIV transmission in macaques by daily or intermittent prophylaxis with emtricitabine and tenofovir. PLoS Med 5(2): e28. doi:10.1371/journal.pmed.0050028 http://medicine.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pmed.0050028

Adapted from materials provided by Public Library of Science, via EurekAlert!, a service of AAAS.

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Oldest Horseshoe Crab Fossil Found, 445 Million Years Old

Daily Science Journal (Feb. 12, 2008) — Few modern animals are as deserving of the title “living fossil” as the lowly horseshoe crab. Seemingly unchanged since before the Age of Dinosaurs, these venerable sea creatures can now claim a history that reaches back almost half-a billion years.

Lunataspis aurora - fossil paratype specimen (about 25 mm wide) beside the dried carapace of a young modern horseshoe crab. (Credit: Left image courtesy of G. Young, The Manitoba Museum; right, D. Rudkin, Royal Ontario Museum)

In a collaborative research article published recently in the British journal Palaeontology, a team of Canadian scientists revealed rare new horseshoe crab fossils from 445 million year-old Ordovician age rocks in central and northern Manitoba, which are about 100 million years older than any previously known forms.

Palaeontologist Dave Rudkin from the Royal Ontario Museum, with colleagues Dr. Graham Young of The Manitoba Museum (Winnipeg) and Dr. Godfrey Nowlan at the Geological Survey of Canada (Calgary), gave their remarkable new fossils the scientific name Lunataspis aurora, meaning literally “crescent moon shield of the dawn” in reference to their shape, geological age and northerly discovery sites. Although they are more “primitive” in several aspects than other known horseshoe crabs, their resemblance to living forms is unmistakable.

The fossil horseshoe crabs were recovered in the course of fieldwork studies on ancient tropical seashore deposits, providing yet another important link to their modern descendants that are today found along warmer seashores of the eastern United States and the Indian Ocean.

This is particularly significant, explains Rudkin. “Understanding how horseshoe crabs adapted to this ecological niche very early on, and then remained there through thick and thin, can give us insights into how ocean and shoreline ecosystems have developed through deep time.”

Today, marine shorelines worldwide are being threatened by human activity, and although some horseshoe crab populations are endangered, their enviably long record on Earth indicates that they have successfully weathered many previous crises, including the mass extinction that saw the demise of the dinosaurs and many other life forms 65 million years ago.

“We do need to be concerned about horseshoe crabs and many of the other unusual life forms found on marine shores,” said Dr. Young. “Nevertheless, we can also be mildly optimistic that some of these things have demonstrated a toughness that may allow them to survive our abuse of these environments.”

Living horseshoe crabs are extensively studied, especially in the fields of ecology and medical research. The exciting discovery of these unusual early fossil relatives adds a new introductory chapter to their remarkable story.

David Rudkin is Assistant Curator in the Department of Natural History (Palaeobiology) at the Royal Ontario Museum, and holds an appointment to the Department of Geology, University of Toronto, as a Lecturer in palaeontology. Rudkin joined the former Department of Invertebrate Palaeontology at the ROM in 1975 and began working on fossils from the Burgess Shale in British Columbia.

Adapted from materials provided by Royal Ontario Museum.

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Tobacco Could Kill One Billion By 2100, WHO Report Warns

Daily Science Journal (Feb. 11, 2008) — WHO has released new data showing that while progress has been made, not a single country fully implements all key tobacco control measures, and outlined an approach that governments can adopt to prevent tens of millions of premature deaths by the middle of this century. Unless urgent action is taken, tobacco could kill one billion this century.

Cigarette butts. Unless urgent action is taken, tobacco could kill one billion this century, WHO report warns. (Credit: iStockphoto/James Curtis)

Current status of tobacco-related deaths

• 100 million dead in the 20th century

• Currently 5.4 million deaths every year

Unless urgent action is taken

• By 2030, there will be more than 8 million deaths every year

• By 2030, more than 80% of tobacco deaths will be in developing countries

• One billion estimated deaths during the 21st century

In a new report which presents the first comprehensive analysis of global tobacco use and control efforts, WHO finds that only 5% of the world’s population live in countries that fully protect their population with any one of the key measures that reduce smoking rates. The report also reveals that governments around the world collect 500 times more money in tobacco taxes each year than they spend on anti-tobacco efforts. It finds that tobacco taxes, the single most effective strategy, could be significantly increased in nearly all countries, providing a source of sustainable funding to implement and enforce the recommended approach, a package of six policies called MPOWER.

“While efforts to combat tobacco are gaining momentum, virtually every country needs to do more. These six strategies are within the reach of every country, rich or poor and, when combined as a package, they offer us the best chance of reversing this growing epidemic,” said Dr Margaret Chan, Director-General of WHO. Dr Chan launched the WHO Report of the Global Tobacco Epidemic at a news conference with New York Mayor Michael Bloomberg. Bloomberg Philanthropies helped fund the report.

“The report released today is revolutionary,” Mayor Bloomberg said. “For the first time, we have both a rigorous approach to stop the tobacco epidemic and solid data to hold us all accountable. No country fully implements all of the MPOWER policies and 80% of countries don’t fully implement even one policy. While tobacco control measures are sometimes controversial, they save lives and governments need to step up and do the right thing.”

The six MPOWER strategies

• Monitor tobacco use and prevention policies

• Protect people from tobacco smoke

• Offer help to quit tobacco use

• Warn about the dangers of tobacco

• Enforce bans on tobacco advertising, promotion and sponsorship

• Raise taxes on tobacco

The report also documents the epidemic's shift to the developing world, where 80% of the more than eight million annual tobacco-related deaths projected by 2030 are expected to occur.

This shift, the report says, results from a global tobacco industry strategy to target young people and adults in the developing world, ensuring that millions of people become fatally addicted every year. The targeting of young women in particular is highlighted as one of the “most ominous potential developments of the epidemic’s growth".

The global analysis, compiled by WHO with information provided by 179 Member States, gives governments and other groups a baseline from which to monitor efforts to stop the epidemic in the years ahead. The MPOWER package provides countries with a roadmap to help them meet their commitments to the widely embraced global tobacco treaty known as the WHO Framework Convention on Tobacco Control, which came into force in 2005.

WHO is also working with global partners to scale up the help that can be offered to countries to implement the strategies.

Dr Douglas Bettcher, Director of WHO’s Tobacco Free Initiative, said the six MPOWER strategies would create a powerful response to the tobacco epidemic. “This package will create an enabling environment to help current tobacco users quit, protect people from second-hand smoke and prevent young people from taking up the habit,” he said.

Other key findings in the report

• Only 5% of the global population is protected by comprehensive national smoke-free legislation and 40% of countries still allow smoking in hospitals and schools;

• Only 5% of the world’s population lives in countries with comprehensive national bans on tobacco advertising and promotion;

• Just 15 countries, representing 6% of the global population, mandate pictorial warnings on tobacco packaging;

• Services to treat tobacco dependence are fully available in only nine countries, covering 5% of the world’s people;

Tobacco tax revenues are more than 4000 times greater than spending on tobacco control in middle-income countries and more than 9000 times greater in lower-income countries. High- income countries collect about 340 times more money in tobacco taxes than they spend on tobacco control.

PDF of full report: http://www.who.int/entity/tobacco/mpower/mpower_report_full_2008.pdf

Adapted from materials provided by World Health Organization.

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New Finding May Help Explain Development Of Preeclampsia

Daily Science Journal (Feb. 11, 2008) — In a study of pregnant women, those with pregnancy-induced high blood pressure were found to have higher levels of a peptide that raises blood pressure in the pieces of tissue linking mother and fetus, according to researchers at Wake Forest University Baptist Medical Center. The finding, reported online in the journal Hypertension, may help explain how the disorder develops.

Preeclampsia, or high blood pressure induced by pregnancy, affects 7 to 10 percent of pregnancies in the United States and is the second-leading cause of maternal mortality. It is the leading cause of pre-term delivery and contributes significantly to stillbirths and death in newborns.

The researchers found that in women with preeclampsia, levels of angiotensin II (Ang II), a hormone that constricts blood vessels and causes blood pressure to rise, was doubled in the chorionic villi, part of the placenta that links mother and fetus and supplies food and oxygen.

"This finding may be part of the preeclampsia puzzle," said Lauren Anton, a graduate student who is first author on the research. "Anything that gets us closer to understanding this disease is important because there is no treatment and no cure and women are still delivering babies too early."

The researchers theorize that Ang II may restrict the fetal vessels that lie within the chorionic villi, which not only raises blood pressure, but also lowers oxygen and nutrient flow to the baby and may result in lower birth weight and other complications of preeclampsia.

The study involved 21 women with preeclampsia and 25 women without the disorder. After delivery, tissue sections were taken from the center of the placenta for analysis.

Ang II is part of the renin angiotensin system (RAS) that regulates blood pressure. The system has been shown to play an important role in preeclampsia. However, changes in the system also occur in women who don't develop the condition. In normal pregnancies, estrogen causes increased levels of several hormones, including Ang II, in the blood. Despite the increase of Ang II in the blood during pregnancy, most women do not develop preeclampsia.

This the first study to demonstrate that all three peptides involved in the RAS are found in the chorionic villi of both normal and preeclamptic women. And, it was the first to show that levels of Ang II are higher in the chorionic villi of women with preeclampsia.

"This implies that local tissues are contributing to the problem," said K. Bridget Brosnihan, Ph.D., senior researcher, who has been studying preeclampsia for 12 years. "The hormone is remarkably elevated in this relatively small tissue, which implies that it has an important role in the development of preeclampsia."

The researchers hope that the findings may one day lead to treatment for preeclampsia.

ACE inhibitor drugs are currently used to lower Ang II in non-pregnant women with hypertension, but these drugs cannot be given to pregnant women. The study authors suggest that other therapies aimed at regulating blood pressure might be beneficial if they target the chorionic villi rather than the system as a whole. They are currently working to determine if growth factors that cause the placenta's blood supply to develop may also be regulated by the increase in Ang II.

The study was supported, in part, by the National Institutes of Health and the American Heart Association. It was published in the Go Red issue of Hypertension that is dedicated to women's cardiovascular health.

Co-researchers are David Merrill, M.D., Ph.D., Liomar Neves, Ph.D., Kathryn Stovall, B.S., Patricia Gallagher, Ph.D., Debra Diz, Ph.D., Cheryl Moorefield, R.N., Courtney Gruver, R.N., and Carlos Ferrario, M.D., all with Wake Forest.

Adapted from materials provided by Wake Forest University Baptist Medical Center, via EurekAlert!, a service of AAAS.

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Botox Linked To Respiratory Failure And Death, FDA Advises

Daily Science Journal (Feb. 11, 2008) — The U.S. Food and Drug Administration has notified the public that Botox and Botox Cosmetic (Botulinum toxin Type A) and Myobloc (Botulinum toxin Type B) have been linked in some cases to adverse reactions, including respiratory failure and death, following treatment of a variety of conditions using a wide range of doses.

In an early communication based on the FDA's ongoing safety review, the agency said the reactions may be related to overdosing. There is no evidence that these reactions are related to any defect in the products.

The adverse effects were found in FDA-approved and nonapproved usages. The most severe adverse effects were found in children treated for spasticity in their limbs associated with cerebral palsy. Treatment of spasticity is not an FDA-approved use of botulism toxins in children or adults.

The adverse reactions appear to be related to the spread of the toxin to areas distant from the site of injection, and mimic symptoms of botulism, which may include difficulty swallowing, weakness and breathing problems.

The FDA is not advising health care professionals to discontinue prescribing these products.

The agency is currently reviewing safety data from clinical studies submitted by the drugs' manufacturers, as well as post-marketing adverse event reports and medical literature. After completing a review of the data, the FDA will communicate to the public its conclusions, resulting recommendations, and any regulatory actions.

Adapted from materials provided by US Food And Drug Administration.

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History Of Quaternary Volcanism And Lava Dams In Western Grand Canyon

Daily Science Journal (Feb. 11, 2008) — John Wesley Powell wrote in 1895: “...what a conflict of water and fire there must have been [in western Grand Canyon]! Just imagine a river of molten rock running down over a river of melted snow.”

Toroweap Point in Grand Canyon national park. (Credit: iStockphoto/Natalia Bratslavsky)

Over 110 years later, a synthesis of new and existing dates on these lava flows shows that many are significantly younger than initially thought and all are less than 725 thousand years old. The geochronology data indicates four major episodes when lava flows either erupted into the canyon or flowed over the rim into it: 725-475 thousand years ago (ka), 400-275 ka, 225-150 ka, and 150-75 ka.

These flows formed lava dams in western Grand Canyon that had dramatic impact on the Colorado River.

This paper* presents light detection and ranging (lidar) data to establish the elevations of the tops and bottoms of basalt flow remnants along the river corridor. These data show the original extent of now-dissected intra-canyon flows and aid in correlation of flow remnants.

From 725 to 475 ka, volcanism built a high edifice within Grand Canyon in the area of the Toroweap fault, with dike-cored cinder cones on both rims and within the canyon itself. These large-volume eruptions helped drive the far-traveled basalt flows which flowed down-canyon over 120 km. A second episode of volcanism, from 400 to 275 ka, built a 215-m-high dam along the Hurricane fault, about 15 km downstream.

The ca. 200 and 100 ka flows (previously mapped as Gray Ledge) were smaller flows and lava cascades that entered the canyon from the north rim between the Toroweap and Hurricane faults.

The combined results suggest a new model for the spatial and temporal distribution of volcanism in Grand Canyon in which composite lava dams and edifices were generally leaky in proximal areas.

Available data suggest that the demise of volcanic edifices may have involved either large outburst-flood events or normal fluvial deposition at times when the river was established on top of basalt flows. These data highlight complex interactions of volcanism and fluvial processes in this classic locality.

This research, authored by Ryan Crow (University of New Mexico) et al. was published in the February issue of Geosphere, published by the Geological Society of America.

Adapted from materials provided by Geological Society of America.

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Using Musical Chords To Analyze And Illustrate Hydrogen Molecule's Response To Laser Pulses

Daily Science Journal (Feb. 10, 2008) — For Kansas State University physics professor Uwe Thumm, confirmation of a theory about the behavior of small molecules became music to his ears -- literally. He and colleagues in Heidelberg, Germany, have shown how a hydrogen molecule responds to laser pulses by using the changing musical chord created by the molecule's vibrational motion.

Researchers in Heidelberg visualized the development over time of molecular resonance. The distance between the two nuclei (R) in the heavy hydrogen (deuterium) ion D2+ is plotted against the time. After approximately 100 femtoseconds, the wave packet, i.e. the location of the nuclei, starts to become hazy, after 400 femtoseconds there is a "revival" and the wave packet is put back together again. (Credit: Max Planck Institute for Nuclear Physics)

Thumm is a member of K-State's J.R. Macdonald Laboratory, where he is among several researchers who work on the properties and behavior of atoms and small molecules.

For decades, researchers had used the Macdonald Laboratory to make atoms and molecules collide with particles. Thumm said much of what scientists know about atoms and molecules is based on such collision experiments. To predict and explain what happens in these collisions, a large group of experimental physicists works closely with Thumm and two other theorists. The theorists use computers, make models and crunch numbers with the hope of producing results that are compatible with what experiments show.

Thanks to improvements in laser technology, around 1999 the Macdonald Laboratory researchers realized that they could transfer a lot of their expertise in atomic collisions to study in detail what happens when atoms and molecules get irradiated by very intense laser light. The new laser systems in the laboratory offer some advantages over the big particle accelerators, Thumm said. The laser pulses offer more control and can be made so short that the researchers now routinely observe the motion of nuclei inside small molecules in time. In addition, the laser pulses' peak intensity is enormous and would equal all of the sun's light focused onto a small spot of the size of a postage stamp or smaller.

Motivated by these opportunities, Thumm and his colleagues became curious about figuring out what would happen if the smallest and simplest molecule, hydrogen, were exposed to such ultra short and intense laser pulses. Together with his postdoctoral collaborator Bernold Feuerstein, Thumm developed a model and did calculations to determine how laser pulses influence the motion of the two protons in the hydrogen molecule.

"The short answer is that the laser pulse either makes the molecules vibrate more violently or blows them apart," Thumm said. He said this wasn't surprising because in the hydrogen molecule, two protons are connected by two electrons that function like a spring. When hit with the laser pulses, the protons oscillate back and forth.

Although this model may be easy to imagine on a large scale, Thumm said particles behave differently at the quantum level. This means that determining the locations of these oscillating protons isn't easy. Thumm described determining the protons' movements after being hit with the laser like what happens if you drop a marble in a bathtub. Looking at the circular ripples of water in the center of the tub, it's pretty easy to tell where the marble was dropped in. But when those ripples bounce off the sides of the tub, the wave pattern changes shape, and it becomes harder to tell where the marble was dropped. The wave gets delocalized. Thumm said the same thing happens to the protons not in a matter of seconds, but in a matter of femtoseconds -- that's a billionth of a millionth of a second. After about 60 femtoseconds, it's impossible to tell where the protons are.

"You quickly loose track of what the distance between the two protons is," Thumm said." All you can say is that they have a certain likelihood of being at a certain distance. This is in agreement with the bathtub experiment: Seconds after the marble was dropped, you can't tell where exactly it plunged in."

But things work differently at the quantum level, and the researchers were surprised that about 600 femtoseconds after being hit with the laser, the distance between the protons again becomes well defined. "We call this a revival of the original motion of the protons," Thumm said. "It's not going to happen in the bathtub, but it happens at the quantum level."

Thumm and Feuerstein published their theoretical prediction in 2003. Thumm said that they were pleasantly surprised when experiments at the Max-Planck Institute in Heidelberg, Germany, in 2006 confirmed the revival described in their model. "The agreement between the new experiments and our model was almost perfect and exceeded our expectations," Thumm said.

Feuerstein had since moved to Heidelberg, where he and his group of researchers continued to collaborate with Thumm's group at K-State. Excited about the success of their model, they began to analyze the molecule's vibrational motion by breaking it down into its various frequencies. Each frequency being like a note in a chord, the frequencies told researchers how the protons were behaving. However, the frequency of these molecular vibrations is way above the audible range. The two researchers share an interest in music and had collaborated musically before. So when it came time to illustrate the revival, they decided the best way to do it was to scale the frequencies down to 1,000 Hertz, which is in the range at which the human ear hears best. "This way you can listen to the vibrations and hear the revival. In the same way sound is analyzed and decomposed, we decomposed the vibration with regard to the frequencies," Thumm said. Their result, a changing musical chord coupled with a movie illustrating the protons' vibrations can be heard and viewed at http://www.mpg.de/video/FilmundoAudio-KdM.wmv

Thumm said researchers hope to be able to do the same thing for more complex molecules like water or methane. Just as a C Major chord sounds different from a d minor chord, Thumm said other molecules also would have their own unique sound. Thumm and Feuerstein's most recent work was first published last fall in the Physical Review Letters. Their research was supported by the National Science Foundation, the U.S. Department of Energy and the Max-Planck Society. Thumm said such basic research supports the long-term goal of applying lasers to steer chemical reactions. The hope is to largely increase the efficiency of chemical reactions by enhancing desired reaction pathways with lasers, he said.

Adapted from materials provided by Kansas State University.

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High Blood Pressure Pill Cuts Risk Of Parkinson's Disease

Daily Science Journal (Feb. 10, 2008) — People taking a widely used group of drugs known as calcium channel blockers to treat high blood pressure also appear to be cutting their risk of Parkinson's disease, according to a new study.

The study involved 7,374 men and women over age 40. Half of the group had Parkinson's disease; the other half did not have Parkinson's disease. Among both groups, nearly half used high blood pressure medications, such as calcium channel blockers, ACE inhibitors, AT II antagonists and beta blockers.

The study found people who were currently long-term users of calcium channel blockers to treat high blood pressure lowered their risk of Parkinson's disease by 23 percent compared to people who didn't take the drugs. There was no such effect among people taking ACE inhibitors, AT II antagonists and beta blockers.

"Long-term use of calcium channel blockers was associated with a reduced risk of developing Parkinson's disease while no such association was seen for other high blood pressure medicines," said study author Christoph R. Meier, PhD, MSc, with University Hospital Basel in Switzerland.

Meier says more research is needed to determine why calcium channel blockers appear to protect against Parkinson's disease, whether this is indeed a causal association, and why the other high blood pressure medications do not offer a reduced risk.

This research was published in the February 6, 2008, online issue of Neurology®, the medical journal of the American Academy of Neurology.

Adapted from materials provided by American Academy of Neurology.

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Teenage Fathers Are More Likely To Have Babies Affected By Birth Problems Than Fathers Over 40

Daily Science Journal (Feb. 10, 2008) — Teenage fathers are at increased risk of having babies born with birth problems ranging from pre-term delivery or low birth weight, through to death in or near to the time of delivery, according to new research.*

In contrast, the study also found that older fathers, aged 40 and over, were not at increased risk of having babies affected by these problems. The results were independent of the age of the mother or other maternal factors that might be expected to have an impact on birth outcomes.

The research is the largest study on the effects of paternal age on adverse birth outcomes. The researchers, from the Ottawa Health Research Institute, Canada, used data from the National Center for Health Statistics for nearly all the births (99%) in the USA between 1995-2000 -- a cohort of more than 23.6 million births. From these, they looked at 2,614,966 singleton babies born live to married women without previous childbearing histories, aged between 20-29, where there was complete information on paternal age, race, maternal education, prenatal care, and gestational and birth weight.

They chose women aged between 20-29 because they were the least likely to be affected by fertility problems, some of which can have an impact on birth outcomes. Since it is already known that fathers aged between 20-29 have the lowest risk of adverse birth outcomes, the researchers used this age group (the reference group) to compare all the other age groups against.

Compared to the reference group and after adjusting for confounding factors (such as race, education, smoking and alcohol drinking during pregnancy, adequacy of prenatal care and the sex of the baby), babies born to teenage fathers (aged less than 20) were more likely to be born early (a 15% increased risk), have low birth weight (13% increased risk), be small for gestational age (17% increased risk), have a low Apgar score (13% increased risk) or to die within the first four weeks after birth (22% increased risk) or to die in the period from four weeks to one year after birth (41% increased risk), although in all cases the absolute risk of death remained less than 0.5% . Fathers aged 40 or over did not have an increased risk of these adverse birth outcomes.

One of the authors of the study, Professor Shi Wu Wen, senior scientist at the Ottawa Health Research Institute and professor at the University of Ottawa, said: "Our study indicated that being a teenage father was an independent risk factor for adverse birth outcomes, whereas advanced paternal age was not. The paternal influence of younger fathers on adverse birth outcomes clearly warrants further investigation, and may lead to a deeper understanding of the causes of such outcomes.

"Although the increased relative risks for most outcomes were small, the magnitude of the risks to society could be huge, given the number of births worldwide, if the increases we found are truly attributable to paternal age."

The study looked at babies born to fathers in seven age groups, from teenagers through to those aged 50 and over, and Prof Wen said this, together with the large size of the study and the limited age range of the mothers, meant that the findings were unlikely to be affected by chance or confounding factors. However, there was no information available on the socio-economic status and lifestyle of the fathers, and this could have an impact.

"The mechanisms by which being a teenage father may contribute to an increased risk of adverse birth outcomes are not clear," said Prof Wen. "Both biological and socio-economic status might play some roles in the observed findings."

Previous studies have shown that younger men can have lower sperm counts, semen volume, total numbers of spermatozoa and percentage of motile sperm. Immature sperm may be associated with adverse birth outcomes, possibly as a result of the abnormal formation of the placenta in the uterus (placentation).

"It is biologically plausible that paternal age might play a role in the risk of adverse birth outcomes associated with abnormal placentation," said Prof Wen.

However, there are also possible social explanations too. "Young fathers are more likely to come from economically disadvantaged families and to have lower educational attainment. Socio-economic factors such as education and occupation are known to be associated with a number of health outcomes. People from less affluent backgrounds are less likely to utilise prenatal care services, which is associated with an increased risk of adverse birth outcomes," explained Prof Wen.

Other social factors that might play a role, perhaps by adversely affecting the mother's health, include domestic violence, lack of financial or emotional support, paternal illicit drug use, smoking and alcohol drinking. "These are more prevalent in teenage fathers, and previous studies have found associations between paternal smoking and alcohol and adverse reproductive outcomes," he said.

Of the finding that older fathers were not more likely to have babies affected by adverse birth outcomes, Prof Wen said: "In our present study, we did not find an association between older fathers and the increased risk of adverse birth outcomes. We could not exclude the possibility that older fathers who married women aged 20-29 years without childbearing history might have a higher socioeconomic status than our control groups. The advantaged socioeconomic conditions might offset some biological risk of adverse birth outcomes associated with older fathers."

Prof Wen said he and his colleagues were planning a pre-conception study to look at various paternal and maternal factors that might have an effect on the health of babies, including paternal age.

*Paternal age and adverse birth outcomes: teenager or 40+, who is at risk? Human Reproduction. doi:10.1093/humrep/dem403.

Adapted from materials provided by European Society for Human Reproduction and Embryology, via EurekAlert!, a service of AAAS.

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Herpes Medication Does Not Reduce Risk Of HIV Infection In Individuals With HSV-2, Study Finds

Daily Science Journal (Feb. 10, 2008) — An international clinical trial has found that acyclovir, a common medication for treating herpes simplex virus-2 (HSV-2), the most common cause of genital herpes, does not reduce the risk of HIV infection when taken by people infected with HSV-2. Multiple studies have shown that people with HSV-2 have a higher risk of acquiring HIV. Researchers had hoped that acyclovir's ability to suppress the herpes virus, and its associated genital sores and breaks in the skin, could cut down on the likelihood of HIV being transmitted to a person with HSV-2 during sexual intercourse.

The Phase III clinical trial was led by the University of Washington in Seattle, in coordination with the HIV Prevention Trials Network, an international consortium funded by the National Institute of Allergy and Infectious Diseases (NIAID) in the National Institutes of Health. The findings were presented this week at the Conference on Retroviruses and Opportunistic Infections in Boston.

"The study was successful in answering the question of whether acyclovir could cut down on the risk of HIV acquisition for people infected with HSV-2," explained Dr. Connie Celum, the leader of the study and a UW professor of global health and medicine in the Division of Allergy and Infectious Disease and director of the International Clinical Research Center in the UW Department of Global Health. "We were hopeful that acyclovir would help reduce HIV acquisition in people with HSV-2. Though the study did not find that acyclovir helped with HIV acquisition, we did find that it reduced genital ulcers associated with HSV-2. Now we need to continue our research on the mechanisms through which HSV-2 acts as a risk factor for HIV, and how we might be able to use that knowledge to reduce the spread of HIV."

HSV-2 is one of the most common sexually transmitted infections worldwide and is especially prevalent in areas with high rates of HIV infection. Most people who are infected with HSV-2 do not know they have the virus because symptoms can be mild or absent. In some infected individuals, the virus can produce recurring genital herpes, a condition characterized by sores and breaks in the skin of the genital region. An active HSV-2 infection also attracts immune-system cells called CD-4 T-cells to the genital region, and HIV easily attaches to this type of cell. Multiple studies have shown that people with HSV-2 have a two-fold increase in their risk of acquiring HIV.

This study followed up on those results to test the theory that suppressing HSV-2 could cut down on HIV acquisition. It was launched in 2003, and with nine study sites in Peru, South Africa, Zambia, Zimbabwe, and the United States, it was the largest study yet of herpes suppression. There were 3,277 people with HSV-2 initially enrolled in the study, 105 people excluded, and 3,172 people included in the final analysis. Volunteers in Peru and the United States were HSV-2-infected men who have sex with men, and volunteers in Africa were HSV-2-infected women.

Half of the participants were randomly assigned to receive either a placebo or a standard daily dose of acyclovir, 400 mg twice a day. The study was double-blinded, meaning that neither participants nor care providers knew which treatment the participants were receiving. Both the placebo and treatment groups received standard HIV-prevention treatment, which includes being supplied with condoms and given extensive counseling on how to reduce the risk of HIV infection.

Researchers found that there was a 3.9 percent HIV incidence rate, a total of 75 cases, in participants who received acyclovir suppression, and a 3.3 percent HIV incidence rate, or 64 cases, in the placebo group. The difference between the groups was not statistically significant. The acyclovir treatment did succeed in reducing genital ulcers -- participants in the treatment group had a 37 percent reduction in genital ulcer incidence, and a significantly lower proportion of ulcers due to HSV-2.

"The study answered the scientific questions it was designed to answer," says Dr. Anna Wald, a UW professor of medicine and epidemiology who also helped lead the study. "The sites were able to recruit and retain a large number of volunteers, who maintained a high level of adherence to the twice-daily drug regimen. While we are disappointed with the results, the study was well-conducted and provides a clear answer about using acyclovir to reduce the risk of becoming HIV-infected."

The study participants have been informed of the findings and are being counseled on the continued need to avoid HIV exposure. Volunteers who became infected with HIV during the trial have been referred for appropriate medical care and treatment.

The study was supported by NIAID, and the acyclovir was supplied by GlaxoSmithKline. The HIV Prevention Trials Network is led by Family Health International, the network laboratory of Johns Hopkins University, and the Statistical Center for HIV/AIDS Research and Prevention at the Fred Hutchinson Cancer Research Center in Seattle. The study was conducted at the following sites: Iquitos, Lima and Pucallpa, in Peru; Johannesburg, South Africa; New York, San Francisco, and Seattle, in the United States; Lusaka, Zambia; and Harare, Zimbabwe.

Adapted from materials provided by University Of Washington.

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Birds, Bats And Insects Hold Secrets For Aerospace Engineers

Daily Science Journal (Feb. 9, 2008) — Natural flyers like birds, bats and insects outperform man-made aircraft in aerobatics and efficiency. University of Michigan engineers are studying these animals as a step toward designing flapping-wing planes with wingspans smaller than a deck of playing cards.

Flapping flight is inherently unsteady, but that's why it works so well. Birds, bats and insects fly in a messy environment full of gusts traveling at speeds similar to their own. Yet they can react almost instantaneously and adapt with their flexible wings. (Credit: iStockphoto/Steve Byland)

A Blackbird jet flying nearly 2,000 miles per hour covers 32 body lengths per second. But a common pigeon flying at 50 miles per hour covers 75. The roll rate of the aerobatic A-4 Skyhawk plane is about 720 degrees per second. The roll rate of a barn swallow exceeds 5,000 degrees per second.

Select military aircraft can withstand gravitational forces of 8-10 G. Many birds routinely experience positive G-forces greater than 10 G and up to 14 G.

“Natural flyers obviously have some highly varied mechanical properties that we really have not incorporated in engineering,” said Wei Shyy, chair of the Aerospace Engineering department and an author of the new book “The Aerodynamics of Low Reynolds Number Flyers.”

“They’re not only lighter, but also have much more adaptive structures as well as capabilities of integrating aerodynamics with wing and body shapes, which change all the time,” Shyy said. “Natural flyers have outstanding capabilities to remain airborne through wind gusts, rain, and snow.” Shyy photographs birds to help him understand their aerodynamics.

Pressure generated during flight cause the flapping wings to deform, he explained. In turn, the deformed wing tells the air that the wing shape is different than it appears in still air. If appropriately handled, this phenomenon can delay stall, enhance stability and increase thrust.

Flapping flight is inherently unsteady, but that’s why it works so well. Birds, bats and insects fly in a messy environment full of gusts traveling at speeds similar to their own. Yet they can react almost instantaneously and adapt with their flexible wings.

Shyy and his colleagues have several grants from the Air Force totaling more than $1 million a year to research small flapping wing aircraft. Such aircraft would fly slower than their fixed wing counterparts, and more importantly, they would be able to hover and possibly perch in order to monitor the environment or a hostile area. Shyy’s current focus is on the aerodynamics of flexible wings related to micro air vehicles with wingspans between 1 and 3 inches.

“These days, if you want to design a flapping wing vehicle, you could build one with trial and error, but in a controlled environment with no wind gusts,” Shyy said. “We are trying to figure out how to design a vehicle that can perform a mission in an uncertain environment. When the wind blows, how do they stay on course?”

A dragonfly, Shyy says, has remarkable resilience to wind, considering how light it is. The professor chalks that up to its wing structure and flight control. But the details are still questions.

“We’re really just at the beginning of this,” Shyy said.

Shyy is the Clarence L. "Kelly" Johnson Collegiate Professor of Aerospace Engineering. Other authors of the book, “Aerodynamics of Low Reynolds Number Flyers” are: U-M research scientists Yongsheng Lian, Jian Tang and Dragos Viieru, and Hao Liu, professor of Biomechanical Engineering at Chiba University in Japan.

Other collaborators on this research include professors Luis Bernal, Carlos Cesnik and Peretz Friedmann of the University of Michigan; Hao Liu of Chiba University in Japan; Peter Ifju, Rick Lind and Larry Ukeiley of University of Florida, and Sean Humbert of University of Maryland.

Adapted from materials provided by University of Michigan.

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Babies Recently Treated With Lotion, Shampoo, And Powder More Likely To Have Phthalates Chemicals In Urine

Daily Science Journal (Feb. 9, 2008) — Babies recently treated with infant personal care products such as lotion, shampoo, and powder, were more likely to have manmade chemicals called phthalates in their urine than other babies, according to University of Washington and Seattle Children's Hospital Research Institute study appearing in the February issue of the journal Pediatrics. Phthalates (pronounced "thah-lates") are added to many personal care and cosmetic products, as well many common household plastic and vinyl products, and some studies suggest they may affect reproductive development in humans.

Babies recently treated with infant personal care products such as lotion, shampoo, and powder, were more likely to have manmade chemicals called phthalates in their urine than other babies. (Credit: iStockphoto/Roman Barelko)

Animal-based studies of phthalates have found that the synthetic chemicals can harm reproductive system development, and studies in humans have found that prenatal exposure or exposure through breast milk can alter hormone concentrations. Early-childhood exposure has not been extensively studied, so additional research is needed to determine if phthalate exposure can indeed cause reproductive development problems or other adverse effects in infants.

In this study, the researchers set out to see if use of personal care products was associated with urine phthalate concentrations. To accomplish this, they collected urine samples from 163 infants aged 2 months to 28 months, and measured the levels of nine different phthalates in those urine samples. They also had the babies' mothers fill out questionnaires on their use of infant personal care products in the past 24 hours.

When they cross-referenced the data, they found that the use of baby powder, lotion, and shampoo were each strongly associated with higher phthalate levels in the urine. The use of baby wipes and diaper cream were not strongly associated with increased levels of phthalates. The scientists also found that every baby had detectable levels of at least one phthalate in their urine, and about 81 percent of the infants had detectable levels of seven or more phthalates. Babies who were 8 months old or younger had stronger associations between product use and phthalate concentrations, as did babies whose mothers used more infant personal care products.

"We found that infant exposure to phthalates is widespread, and that exposure to personal care products applied onto the skin may be an important source," said the study's lead author, Sheela Sathyanarayana, an acting assistant professor of pediatrics at the UW School of Medicine and a researcher with Seattle Children's Hospital Research Institute. "This is troubling, because phthalate exposure in early childhood has been associated with altered hormone concentrations as well as increased allergies, runny nose, and eczema. Babies may be more at risk than children or adults because their reproductive, endocrine, and immune systems are still developing."

Parents who want to decrease their baby's exposure to phthalates should limit the amount of baby care products used on the infant, and apply lotions or powders only if medically indicated. Since phthalates are also found in many household plastic products, like plastic food containers, parents can also stop putting plastics in the microwave oven and use glass alternatives whenever possible. Phthalate-free cosmetics and personal care products are also available.

This research project was supported by grants from the U.S. Environmental Protection Agency, the National Institutes of Health, and the National Institute of Environmental Health Sciences. The project included researchers from the UW Departments of Occupational and Environmental Health Sciences, Pediatrics, and Biostatistics; the Seattle Children's Hospital Research Institute; the Centers for Disease Control and Prevention; and the University of Rochester School of Medicine and Dentistry.

Adapted from materials provided by University Of Washington.

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Knee Brace Generates Electricity From Walking

Daily Science Journal (Feb. 9, 2008) — A new energy-capturing knee brace can generate enough electricity from walking to operate a portable GPS locator, a cell phone, a motorized prosthetic joint or an implanted neurotransmitter, research involving the University of Michigan shows.

The biomechanical energy harvester includes an aluminum chassis and generator mounted on a customized orthopaedic knee brace. The device weighs 3.5 lbs. (Credit: Greg Ehlers/Simon Fraser University)

The wearable mechanism works much like regenerative braking charges a battery in some hybrid vehicles, said Arthur Kuo, an associate professor of mechanical engineering at U-M and an author of the paper.*

Regenerative brakes collect the kinetic energy that would otherwise be dissipated as heat when a car slows down. This knee brace harvests the energy lost when a human brakes the knee after swinging the leg forward to take a step.

Kuo, who called the device "a cocktail-napkin idea," says knee joints are uniquely suited for this endeavor.

"There is power to be harvested from various places in the body, and you can use that to generate electricity. The knee is probably the best place," he said. "During walking, you dissipate energy in various places, when your foot hits the ground, for example. You have to make up for this by performing work with your muscles.

"The body is clever," Kuo said. "In a lot of places where it could be dissipating energy, it may actually be storing it and getting it back elastically. Your tendons act like springs. In many places, we're not sure whether the energy is really being dissipated or you're just storing it temporarily. We believe that when you're slowing down the knee at the end of swinging the leg, most of that energy normally is just wasted."

The scientists tested the knee brace on six men walking leisurely on a treadmill at 1.5 meters per second, or 2.2 miles per hour. They measured the subjects' respiration to determine how hard they were working. A control group wore the brace with the generator disengaged to measure how the weight of the 3.5-pound brace affected the wearer.

In the mode in which the brace is only activated while the knee is braking, the subjects required less than one watt of extra metabolic power for each watt of electricity they generated. A typical hand-crank generator, for comparison, takes an average of 6.4 watts of metabolic power to generate one watt of electricity because of inefficiencies of muscles and generators.

"We've demonstrated proof of concept," Kuo said. "The prototype device is bulky and heavy, and it does affect the wearer just to carry. But the energy generation part itself has very little effect on the wearer, whether it is turned on or not. We hope to improve the device so that it is easier to carry, and to retain the energy-harvesting capabilities."

A lighter version would be helpful to hikers or soldiers who don't have easy access to electricity. And the scientists say similar mechanisms could be built into prosthetic knees other implantable devices such as pacemakers or neurotransmitters that today require a battery, and periodic surgery to replace that battery.

"A future energy harvester might be implanted along with such a device and generate its own power from walking," Kuo said.

The paper "Biomechanical Energy Harvesting: Generating Electricity During Walking with Minimal User Effort" is published in the Feb. 8 issue of the journal Science. Authors include researchers from Simon Fraser University in Canada and the University of Pittsburgh, in addition to U-M.

Adapted from materials provided by University of Michigan.

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Reduced Sleep Can Increase Childhood Obesity Risk

Daily Science Journal (Feb. 9, 2008) — Less sleep can increase a child’s risk of being overweight or obese, according to a study by researchers at the Johns Hopkins Bloomberg School of Public Health. Their analysis of epidemiological studies found that with each additional hour of sleep, the risk of a child being overweight or obese dropped by 9 percent.

“Our analysis of the data shows a clear association between sleep duration and the risk for overweight or obesity in children. The risk declined with more sleep,” said Youfa Wang, MD, PhD, senior author of the study and associate professor with the Bloomberg School’s Center for Human Nutrition. “Desirable sleep behavior may be an important low cost means for preventing childhood obesity and should be considered in future intervention studies. Our findings may also have important implications in societies where children do not have adequate sleep due to the pressure for academic excellence and where the prevalence of obesity is rising, such as in many East Asian countries.”

“The influence of sleep quality on obesity risk is another important area where future research is needed,” added Xiaoli Chen, MD, PhD, the study’s lead author and a former postdoctoral fellow at the Bloomberg School.

For the study, Wang, Chen and colleague May A. Beydoun, also a postdoctoral fellow at the Bloomberg School, reviewed 17 published studies on sleep duration and childhood obesity and they analyzed 11 of them in their meta-analysis.

The recommended amount of daily sleep varied between studies analyzed and with children’s age. It is recommended that children under age 5 should sleep for 11 hours or more per day, children age 5 to10 should sleep for 10 hours or more per day, and children over age 10 should sleep at least 9 hours per day.

The results of the analysis showed that children with the shortest sleep duration had a 92 percent higher risk of being overweight or obese compared to children with longer sleep duration. For children under age 5, shortest sleep duration meant less than 9 hours of sleep per day. For children ages 5 to 10 it meant less than 8 hours of sleep per day and less than 7 hours of sleep per day for children over 10. The association between increased sleep and reduced obesity risk was strongly associated with boys, but not in girls.

The results are published in the February 2008 edition Obesity, the journal of The Obesity Society. “Is Sleep Duration Associated with Childhood Obesity? A Systematic Review and Meta-analysis” was written by Xiaoli Chen, May A. Beydoun and Youfa Wang.

The study was supported in part by the National Institute of Diabetes and Digestive and Kidney Diseases, the U.S. Department of Agriculture and the Johns Hopkins Bloomberg School of Public Health.

Adapted from materials provided by Johns Hopkins University Bloomberg School of Public Health.

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Lifetime Medical Costs Of Obese People Actually Lower Than Costs For Healthy And Fit, Mathematical Model Shows

Daily Science Journal (Feb. 8, 2008) — A new research paper suggests that preventing obesity might result in increased public spending on medical care. Many countries are currently developing policies aimed at reducing obesity in the population. However, it is not currently clear whether successfully reducing obesity will also reduce national healthcare spending or not. Pieter van Baal and colleagues, from the National Institute for Public Health and the Environment in the Netherlands, created a mathematical model to try to answer this question.

Researchers found that the group of healthy, never-smoking individuals had the highest lifetime healthcare costs, because they lived the longest and developed diseases associated with aging; healthcare costs were lowest for the smokers, and intermediate for the group of obese never-smokers. (Credit: iStockphoto/Eliza Snow)

In their study, van Baal and his co-workers created three hypothetical populations of 1000 men and women, all aged 20 years at the start: a group of obese, never-smoking individuals; a group of healthy-never smoking individuals of normal weight; and a group of smokers of normal weight. The model produced an estimate of the likely proportion of each group who would encounter certain long term (chronic) diseases, and then estimated what the approximate cost of medical care associated with each disease was likely to be. The researchers found that the group of healthy, never-smoking individuals had the highest lifetime healthcare costs, because they lived the longest and developed diseases associated with aging; healthcare costs were lowest for the smokers, and intermediate for the group of obese never-smokers.

However, the authors argue that although obesity prevention may not be a cure for increasing expenditures, it may well be a cost-effective cure for much morbidity and mortality and importantly contribute to the health of nations.

A Perspective by Klim McPherson, from Oxford University in the UK, who was not involved in the study, discusses the implications of these findings and comments that "it would be wrong to interpret the findings as meaning that public-health prevention (e.g., to prevent obesity) has no benefits"; the quality of life experienced by individuals, and other factors, must also be taken into account when planning interventions aimed at improving public health.

Citation: van Baal PHM, Polder JJ, de Wit GA, Hoogenveen RT, Feenstra TL, et al. (2008) Lifetime medical costs of obesity: Prevention no cure for increasing health expenditure. PLoS Med 5(2): e29. doi:10.1371/journal.pmed.0050029 http://medicine.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pmed.0050029

Adapted from materials provided by Public Library of Science, via EurekAlert!, a service of AAAS.

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'Weight Training' Reduces Fat And Improve Metabolism In Mice

Daily Science Journal (Feb. 8, 2008) — Researchers from the Boston University School of Medicine (BUSM) have demonstrated that in mice, the use of barbells may be as important to losing weight and improving health as the use of running shoes. The discovery builds upon the fact that skeletal muscle consists of two types of fibers. Endurance training such as running increases the amount of type I muscle fibers, while resistance training such as weightlifting increases type II muscle fibers. Using a mouse genetic model, BUSM researchers demonstrated that an increase in type II muscle mass can reduce body fat which in turn reduces overall body mass and improves metabolic parameters such as insulin resistance. These studies indicate that weight bearing exercise, in addition to endurance training, may benefit overweight people.

Weight-lifting. "We've shown that type II muscle does more than allow you to pick up heavy objects," said Kenneth Walsh of Boston University School of Medicine. "It is also important in controlling whole-body metabolism." (Credit: iStockphoto/Sean Locke)

Researchers used a genetic trick in obese mice that caused the mice's muscles to bulk up as though they had been lifting weights. The researchers found that the "genetically reprogrammed" mice lost fat and showed other signs of metabolic improvement throughout the body. What's more, those benefits were seen even though the mice continued eating a diet high in both fat and sugar and didn't increase their physical activity at all.

The researchers genetically engineered a mouse, called the MyoMouse, to grow type II fibers by activating a muscle growth-regulating gene. The gene, called Akt1, was engineered in such a way that it could be turned on and off at will by researchers. Even without exercise, activating the gene made the MyoMouse physically stronger. When the gene was de-activated, the mouse returned to its original strength. While stronger and faster than a regular mouse, the MyoMouse did not run with as much endurance on a treadmill, a finding that is consistent with the growth of type II rather than type I muscle. These findings demonstrate that the mouse was genetically programmed to have the characteristics of a lean and powerful sprinter rather than those of a gaunt marathon runner.

"We've shown that type II muscle does more than allow you to pick up heavy objects," said Kenneth Walsh of Boston University School of Medicine. "It is also important in controlling whole-body metabolism."

In the study, the Akt1 gene was turned off and the MyoMice were fed a high fat/high sugar diet with a similar caloric composition as a meal from a fast food restaurant. Over an eight-week period, the mice became obese and insulin resistant and developed fatty acid deposits in their liver, a condition referred to as hepatic steatosis or fatty liver disease.

The researchers then activated the Akt1 gene in the animals which led to the growth of type II muscle fibers. "Remarkably, type II muscle growth was associated with an overall reduction in body mass, due to a large decrease in fat mass. In addition, blood tests showed that these mice became metabolically normal and their fatty liver disease rapidly resolved," said senior author Kenneth Walsh, PhD, a professor of medicine and head of Molecular Cardiology at the Whitaker Cardiovascular Institute at BUSM.

The beneficial changes occurred despite the fact that the mice continued to eat the same high-calorie diet and did not display any increase in physical activity. "This work shows that type II muscle just doesn't allow you to pick up heavy objects, it is also important in controlling whole body metabolism," added Walsh.

Further analysis found that the mice burned fat because of changes in the physiology and gene expression of their fat and liver cells. "Thus, it appears that the increase in type II muscle fiber orchestrates changes in the body through its ability to communicate with these other tissues," he said.

These findings indicate that type II muscle has a previously unappreciated role in regulating whole body metabolism through its ability to alter the metabolic properties of remote tissues. These data also suggest that strength training, in addition to the widely-prescribed therapy of endurance training, may be of particular benefit to overweight individuals

Finally, these findings may be relevant for understanding aspects of the aging process. "Beyond the age of thirty, humans lose approximately 6 lbs of muscle mass per decade. Surprisingly, aging individuals predominantly lose type II muscle. Thus a 50 year old may be relatively good at playing tennis or jogging because type I muscle is preserved, but a measurement of grip strength or core body strength could show appreciable declines," explained Walsh. Therefore, this new study suggests that the loss of type II muscle contributes to the development of obesity and diabetes as we age.

The BUSM researchers suspect that the beneficial effects of muscle growth seen in the MyoMouse are mediated through the production and secretion of a variety of signaling factors. Walsh and his colleagues are currently identifying the novel proteins in muscle that communicate with other tissues. These new proteins, referred to as "myokines" from the Greek words "muscle" and "motion," may represent new targets for therapies that mimic the benefits of weight training for the treatment of obesity and diabetes as well as muscle wasting disorders.

"The work of [Walsh and his colleagues] reveals the intricate interplay between diet, energy balance, and the function/morphology of diverse tissue systems such as skeletal muscle and liver," said Brooke Harrison and Leslie Leinwand of the University of Colorado at Boulder in a commentary in the journal Cell Metabolism. "These findings indicate that interventions designed to increase skeletal muscle mass in at-risk human populations may prove to be critical weapons in the fight against obesity and obesity-related comorbidities including diabetes, heart disease, stroke, hypertension, and cancer."

The study appears in the February 6th issue of Cell Metabolism. The researchers include Yasuhiro Izumiya, Teresa Hopkins, Carl Morris, Kaori Sato, Ling Zeng, Jason Viereck, James A. Hamilton, Noriyuki Ouchi, Nathan K. LeBrasseur, and Kenneth Walsh, of Boston University School of Medicine, Boston, MA.

Adapted from materials provided by Boston University, via EurekAlert!, a service of AAAS.

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Giving Mice A Cold Virus Offers Hope Of New Asthma Treatments

Daily Science Journal (Feb. 8, 2008) — Scientists have been able to recreate rhinovirus infection, which is behind most common colds, in a small animal for the first time. For fifty years since they were discovered, it had been thought that rhinoviruses could only infect humans and chimpanzees. But now a team of scientists led by Professor Sebastian Johnston at the MRC/Asthma UK Centre in Allergic Mechanisms of Asthma at Imperial College London, has been able to infect mice with rhinoviruses.

Scientists have been able to recreate rhinovirus infection, which is behind most common colds, in a small animal for the first time. For fifty years since they were discovered, it had been thought that rhinoviruses could only infect humans and chimpanzees. (Credit: iStockphoto/Jennifer Sheets)

Rhinoviruses are an unwelcome inconvenience for the majority of the population as they cause around three quarters of common colds. However they can also have serious consequences. In susceptible people, they can be fatal. They can lead to the hospitalisation of infants, pneumonia in people with weakened immune systems and they trigger most asthma attacks. They are also the major cause of acute attacks of COPD (chronic bronchitis and emphysema), and are thus the major killer in these diseases.

Professor Johnston said: “Until now it has not been possible to study rhinovirus infection in small animals. This has been a major obstacle to developing new treatments and there is currently no effective treatment for rhinovirus infection.”

It had been thought that mice and other small animals were resistant to rhinoviruses. Of the 100 known strains of rhinovirus, 90 per cent use a binding molecule, called ICAM-1 that is found on the surface of human cells, as their receptor. But the viruses are unable to bind to the mouse version of this receptor.

Professor Johnston explained: "We previously found that once inside the mouse cell a rhinovirus reproduces itself as well as it does in human cells. But the virus couldn’t infect the mouse cell because the receptor (acting like a door key) couldn’t get into the cell.

“Now we’ve modified the mouse receptor so it is more like a human one. This means the virus can infect the cells of these modified mice.”

Professor Johnston added: "We found that mice with the modified receptor were susceptible to infection with a rhinovirus. If combined with an allergen (ovalbumin which is found in egg white) that could cause an allergic reaction in the lungs, the virus could make the response worse and lead to an 'asthma attack'."

The team was able to observe that when the virus was combined with an allergic reaction, the mouse responded similarly to humans. This means it provides a good model for the study of severe asthma attacks.

"These mouse models should provide a major boost to research efforts to develop new treatments for the common cold, as well as for more potentially fatal illnesses such as acute attacks of asthma and of COPD."

The chief executive of the Medical Research Council, Sir Leszek Borysiewicz said: “This important and fundamental discovery will enable us to understand the effects rhinoviruses and common colds have on our health. It will open up new paths to finding treatments which have been delayed for many years and provides us with the opportunities for further breakthroughs in the future.”

Leanne Male, Assistant Director of Research at Asthma UK commented: "Ninety per cent of people with asthma tell us that colds and flu triggers their asthma symptoms but as yet there is no specific treatment for virally induced asthma attacks and steroid treatments are only partially effective against them. We welcome this latest advancement as it will lead to a greater understanding of viral infections and their link with asthma and may help the development of a suitable treatment for virus-induced asthma attacks, thus greatly improving the lives of the 5.2 million people with the condition in the UK."

Journal article: Mouse models of rhinovirus-induced disease and exacerbation of allergic airway inflammation. Published online in Nature Medicine.

The research was funded by the Medical Research Council, Asthma UK and GlaxoSmithKline.

Adapted from materials provided by Imperial College London.

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Croatian Children Have Higher Weapons-related Death Rate During And After Homeland War

Daily Science Journal (Feb. 7, 2008) — The Homeland War in Croatia, which occurred from 1991 to 1995, led to an increase in weapon-related deaths of children during and five years after the end of the war, according to a new report.

"After World War II until the beginning of the Homeland War in 1991, most children in Croatia were not exposed to firearms and explosives in their homes or communities," the authors write as background information in the article. "Unlike many countries, personal weapon ownership was not a custom in Croatia." This changed as the Homeland War--also called the Third Balkan War--moved into Croatian land. Citizens began purchasing grenades, firearms and other weapons on the black market or taking them from military barracks after the Yugoslav army left Croatia. The population remained overly militarized in the wake of the war; in 2007, 371,684 weapons were legally owned by Croatians.

Aida Mujkic, M.D., of the University of Iowa, Iowa City, and colleagues studied Croatian children from birth through age 19 who died of weapon-related injuries between 1986 and 2005. Statistics were obtained from Croatia's national vital statistics system and included traumatic injury deaths classified by intent, including homicide, suicide and unintentional categories.

Compared with the period before the war, rates of homicide and suicide with weapons more than tripled during the war--from .22 to .73 homicides and .51 to 1.64 suicides per 100,000 children. Unintentional weapon-related deaths also increased by more than six-fold, from .25 to 1.63 per 100,000 children.

"These increases persisted for five years following the end of the war and decreased more than five years after the war," the authors write. Weapons-related deaths in the early postwar period--1996 to 2000--remained more than twice as high as before the war, and the weapon-related suicide rate remained more than three times that of the pre-war period. Homicide and unintentional injury deaths decreased significantly in the late post-war period, 2001 to 2005, and suicide rates were the same as in the pre-war period. The number of children who died from causes other than weapons did not change over the course of the study.

"Programs that focus on the prevention of weapon-related injuries should be integrated into programs that assist countries in rebuilding after political unrest," the authors conclude. "The combination of psychological effects of war on children with an increased presence of weapons may present a particularly important area for prevention."

Journal reference: Arch Pediatr Adolesc Med. 2008;162[2]:140-144.

This study was supported by an NIH grant from the University of Iowa/Fogarty International Traumatic Injury Training Program.

Adapted from materials provided by JAMA and Archives Journals.

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Magma And Volcanoes: Physicists Explain Dance Marathon Of Wispy Feature In Roiling Fluids

Daily Science Journal (Feb. 7, 2008) — Theoretical physicists at the University of Chicago are suggesting how thin spouts of magma in the Earth's mantle can persist long enough to form hotspot volcanism of the type that might have created the Hawaiian Islands.

University of Chicago physicists Wendy Zhang (left) and Laura Schmidt explain a feature of convecting fluids that colleagues have observed in laboratory experiments. The feature may help explain how hotspot volcanism created the Hawaiian Islands and other such landforms. (Credit: Dan Dry)

Their calculations also apply to tendrils only a few inches long that form in convecting fluids under laboratory conditions. University of Chicago graduate student Laura Schmidt and Wendy Zhang, an Assistant Professor in Physics, will detail their findings in the Feb. 1 issue of the journal Physical Review Letters.

The work was inspired by laboratory experiments conducted by Anne Davaille in France that mimic, in a simplified way, convecting bubbles of magma as they might look deep beneath the Earth's surface. "This is one robust feature of thermal convection," Zhang said.

"It's a useful thing to know because it's the kind of thing that happens in all sorts of different industries, in all sorts of different contexts." These include oil extraction, the chemical industry and in certain biotechnological applications.

Earth scientists also have theorized that mantle plumes form on a regional scale in the Earth's interior, sometimes breaking the surface to form small landmasses, including Hawaii and Iceland. Nevertheless, debate swirls around how, or even if, mantle plumes can account for such surface features.

Geophysicists often liken a pot of boiling water as a smaller, more rapid version of the convection that takes place in the mantle, the layer of Earth that lies between the surface crust and its core. But unlike a pot of water, the Earth's interior consists of layers with different properties.

In laboratory experiments, Anne Davaille, a geophysicist at the University of Paris 7, studies convection in a small tank by heating two layers of colored liquids of differing densities. She observed the formation and persistence of thin tendrils between the layers, which correspond to subsurface plumes measuring scores of miles across.

"It seems so thin and tenuous, how could it possibly manage to hold itself in place over time as everything else is going on around it?" Zhang asked. "Somehow, they manage to hold themselves together."

The tendrils persist for hours, even as experimental conditions change. "These tendrils have fluid flowing through them, and it starts to mix the two layers," Schmidt said. "When the two layers mix, then the viscosity of the layers changes as well."

Following a series of visits to Davaille's lab, Schmidt and Zhang sought to mathematically explain the phenomenon.

"When you look at the shape of these very thin tendrils, there's something very striking that Anne noticed right away," Zhang said. The tendrils seem to emerge from flow lines that resemble the flared-out end of a trumpet. This trumpet shape marked the location of a stagnation point. Both Davaille's experiments and Schmidt's calculations agree: The thinnest tendrils that persist have a stagnation point.

Schmidt had seen a similar stagnation point in experiments she conducted in the laboratory of Sidney Nagel, the Stein-Freiler Distinguished Service Professor in Physics at the University of Chicago. Those experiments involved unmixable fluids, such as water and oil, instead of the fresh water and salt water mixing in Davaille's laboratory.

Nevertheless, the experimental similarities provided Schmidt and Zhang insights that helped solve the problem. In previous studies, other theoreticians suggested how large flows might rise through the tendrils from the base of the hot spots, Schmidt said. She and Zhang approached the problem differently.

"We include the effect of the stagnation point," Schmidt explained. "Our tendrils are really a thin skin or thin layer of the surface between the fluids that is drawn up. It's not a bulk flow going up through the tendril."

Adapted from materials provided by University of Chicago, via EurekAlert!, a service of AAAS.

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Subconscious Signals Can Trigger Drug Craving

Daily Science Journal (Feb. 7, 2008) — Using a brain imaging technology called functional magnetic resonance imaging (fMRI), scientists have discovered that cocaine-related images trigger the emotional centers of the brains of patients addicted to drugs -- even when the subjects are unaware they've seen anything.

Cocaine patients were shown photos such as these. The 24 randomly-presented 33 msec targets in each of four categories (cocaine, sexual, aversive and neutral, interspersed with grey-screen nulls) were immediately followed by a 467 msec neutral “masking” stimulus”. Under these conditions, the 33 msec stimuli can escape conscious detection. (Credit: Childress AR, Ehrman RN, Wang Z, Li Y, Sciortino N, et al.)

A team of researchers at the University of Pennsylvania, led by Dr. Anna Rose Childress and Dr. Charles O'Brien, showed cocaine patients photos of drug-related cues like crack pipes and chunks of cocaine. The images flashed by in just 33 milliseconds -- so quickly that the patients were not consciously aware of seeing them. Nonetheless, the unseen images stimulated activity in the limbic system, a brain network involved in emotion and reward, which has been implicated in drug-seeking and craving.

"This is the first evidence that cues outside one's awareness can trigger rapid activation of the circuits driving drug-seeking behavior," said NIDA director Dr. Nora Volkow. "Patients often can't pinpoint when or why they start craving drugs. Understanding how the brain initiates that overwhelming desire for drugs is essential to treating addiction."

To verify that the patterns of brain activity triggered by the subconscious cues reflected the patients' feelings about drugs, Childress and her colleagues gave the patients a different test two days later, allowing them to look longer at the drug images. The patients who demonstrated the strongest brain response to unseen cues in the fMRI experiment also felt the strongest positive association with visible drug cues. Childress notes, "It's striking that the way people feel about these drug-related images is accurately predicted by how strongly their brains respond within just 33 milliseconds."

Childress and her colleagues also found that the regions of the brain activated by drug images overlapped substantially with those activated by sexual images. This finding supports the scientific consensus that addictive drugs usurp brain regions that recognize natural rewards needed for survival, like food and sex.

According to Childress, these results could improve drug treatment strategies. "We have a brain hard-wired to appreciate rewards, and cocaine and other drugs of abuse latch onto this system. We are looking at the potential for new medications that reduce the brain's sensitivity to these conditioned drug cues and would give patients a fighting chance to manage their urges."

Citation: Childress AR, Ehrman RN, Wang Z, Li Y, Sciortino N, et al (2008) Prelude to Passion: Limbic Activation by ''Unseen'' Drug and Sexual Cues. PLoS One 3(1): e1506. doi:10.1371/journal.pone.0001506 http://www.plosone.org/doi/pone.0001506

The study was funded by the National Institute on Drug Abuse (NIDA), part of the National Institutes of Health (NIH).

Adapted from materials provided by Public Library of Science, via EurekAlert!, a service of AAAS.

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Chronic Pain Harms The Brain

Daily Science Journal (Feb. 7, 2008) — People with unrelenting pain don't only suffer from the non-stop sensation of throbbing pain. They also have trouble sleeping, are often depressed, anxious and even have difficulty making simple decisions.

Comparison of brains. These images show the brain from the left side, demonstrating striking differences between chronic pain patients and healthy subjects. They illustrate with colors how much activation (red-yellow) or deactivation (dark/light blue) was found at each location. (Credit: Image courtesy of Northwestern University)

In a new study, investigators at Northwestern University's Feinberg School of Medicine have identified a clue that may explain how suffering long-term pain could trigger these other pain-related symptoms.

Researchers found that in a healthy brain all the regions exist in a state of equilibrium. When one region is active, the others quiet down. But in people with chronic pain, a front region of the cortex mostly associated with emotion "never shuts up," said Dante Chialvo, lead author and associate research professor of physiology at the Feinberg School. "The areas that are affected fail to deactivate when they should."

They are stuck on full throttle, wearing out neurons and altering their connections to each other.

This is the first demonstration of brain disturbances in chronic pain patients not directly related to the sensation of pain.

Chialvo and colleagues used functional magnetic resonance imaging (fMRI) to scan the brains of people with chronic low back pain and a group of pain-free volunteers while both groups were tracking a moving bar on a computer screen. The study showed the pain sufferers performed the task well but "at the expense of using their brain differently than the pain-free group," Chialvo said.

When certain parts of the cortex were activated in the pain-free group, some others were deactivated, maintaining a cooperative equilibrium between the regions. This equilibrium also is known as the resting state network of the brain. In the chronic pain group, however, one of the nodes of this network did not quiet down as it did in the pain-free subjects.

This constant firing of neurons in these regions of the brain could cause permanent damage, Chialvo said. "We know when neurons fire too much they may change their connections with other neurons and or even die because they can't sustain high activity for so long," he explained.

'If you are a chronic pain patient, you have pain 24 hours a day, seven days a week, every minute of your life," Chialvo said. "That permanent perception of pain in your brain makes these areas in your brain continuously active. This continuous dysfunction in the equilibrium of the brain can change the wiring forever and could hurt the brain."

Chialvo hypothesized the subsequent changes in wiring "may make it harder for you to make a decision or be in a good mood to get up in the morning. It could be that pain produces depression and the other reported abnormalities because it disturbs the balance of the brain as a whole."

He said his findings show it is essential to study new approaches to treat patients not just to control their pain but also to evaluate and prevent the dysfunction that may be generated in the brain by the chronic pain.

The study will be published Feb. 6 in The Journal of Neuroscience. Chialvo's collaborators in this project are Marwan Baliki, a graduate student; Paul Geha, a post-doctoral fellow, and Vania Apkarian, professor of physiology and of anesthesiology, all at the Feinberg School.

Adapted from materials provided by Northwestern University.

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Early Detection Critical In Treating Pediatric Thyroid Cancer

Daily Science Journal (Feb. 6, 2008) — Efforts to treat pediatric papillary thyroid cancer are greatly improved by detecting the disease as early as possible, making the patient's age the most important factor in determining a prognosis, according to new research published in the February 2008 issue of the journal Otolaryngology -- Head and Neck Surgery.

The study, authored by Italian researchers, evaluated 2,709 patients who underwent a total thyroidectomy to treat papillary thyroid carcinoma (PTC). Among the group's pediatric patients (younger than 18 years old), the cancer was observed to be much more aggressive than that in adult patients. However, despite the aggressive course of the disease, this did not influence the patient's survival rate, since cases of pediatric cancer have a better prognosis than that in adults. As a result, the authors concluded that age of detection is the single most important factor to consider when issuing a prognosis.

Thyroid cancer is the third most common tumor malignancy in children. It is one of the few cancers that has increased in incidence rates over the past several years, with an estimated 11 percent increase from 2006 to 2007. Papillary thyroid cancer occurs in cells that produce thyroid hormones containing iodine. This type, the most common form of thyroid cancer in children, grows very slowly.

The study also confirms that PTC is more prevalent in younger patients, compared with other age groups; these patients also had significantly larger tumors. However, the study's authors concluded that the size of the tumor, which is considered a significant factor in determining prognosis in adult patients, does not play a significant role in a child's prognosis.

The study also suggests a longer period for follow-ups is in order to more accurately measure the success of treatment.

Adapted from materials provided by American Academy of Otolaryngology, Head and Neck Surgery, via EurekAlert!, a service of AAAS.

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Environmental Epigenetics Has Potential For Preventing And Treating Disease

Daily Science Journal (Feb. 6, 2008) — New research on environmental influences on health and disease has begun to shed light on why genetically identical individuals demonstrate different characteristics, such as susceptibility to disease. Scientists have found that environmental exposure to nutritional, chemical and physical factors can alter the epigenome. Literally meaning “above the genome,” the epigenome refers to differences in gene expression that are inherited without changing the sequence of DNA.

New research* examines some of the epigenetic mechanisms linked to disease, and explores how they occur and their significance in understanding, treating and preventing disease.

Authors Randy L. Jirtle and Dana C. Dolinoy of Duke University Medical Center in Durham, North Carolina, discuss genomic imprinting, a form of gene regulation in which epigenetic modifications in chromosomes result in differences in gene expression. First identified in 1991, there are approximately 80 imprinted genes that have been identified in mice and humans. Because imprinted genes behave as if they have a single set of chromosomes rather than the usual two, the health consequences of mutations in these genes are potentially disastrous, resulting in diseases such as cancer and several severe pediatric developmental disorders.

In addition, mutations that occur in non-imprinted regions can influence the regulation of imprinted genes. The authors previously demonstrated that imprinting evolved anywhere from 230 to 150 million years ago, arising in mammals with the evolution of the placenta. They note that the expression of imprinted genes is species, tissue and developmental stage dependent and may play an important role in the speciation of mammals.

The article cites several studies involving metastable epialleles, which are alternate forms of a gene that are expressed due to epigenetic modifications linked to maternal nutrition and environmental exposure during very early development. The authors note that simple dietary changes were found to protect against the negative effects of environmental toxins on the fetal epigenome. They also cite evidence that embryos are vulnerable to environmentally-induced epigenetic alterations early in their development, highlighting the need to analyze the timing of exposure in order to fully understand environmental epigenomics.

The advent of bioinformatics has allowed researchers to more readily search the entire mouse genome for imprinted genes, but the real power of this approach has been recently demonstrated in its application to the human genome. While 2.5 percent of the mouse genome contains potentially imprinted genes, only 0.75 percent of the human genome is predicted to be imprinted. This means that the mouse genome may not be a suitable model for assessing human disease risk due to epigenetic mutations in imprinted genes. The authors point out the necessity of developing bioinformatic models that can identify metastable epialleles in order to characterize all of the genes susceptible to environmental influences.

With the identification of epigenetically unstable locations in the human genome, it will be possible to screen individuals at an early age for epigenetically susceptible diseases, allowing for closer monitoring and more frequent follow-up. In addition, unlike genetic mutation, epigenetic profiles are potentially reversible. “Therefore, epigenetic approaches for prevention and treatment, such as nutritional supplementation and/or pharmaceutical therapies may be developed to counteract negative epigenomic profiles,” the authors conclude. “The future of epigenomics therapy holds tremendous potential for not only individualized health care but also for population-wide disease diagnostic, screening, and prevention strategies.”

*Article: “Environmental Epigenomics in Human Health and Disease,” Dana C. Dolinoy and Randy L. Jirtle, Environmental and Molecular Mutagenesis, January 2008, 49:1.

Adapted from materials provided by Blackwell Publishing Ltd.

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Particle Accelerator May Reveal Shape Of Alternate Dimensions

Daily Science Journal (Feb. 6, 2008) — When the world's most powerful particle accelerator starts up later this year, exotic new particles may offer a glimpse of the existence and shapes of extra dimensions.

A new particle accelerator, the Large Hadron Collider, is scheduled to begin operating later this year near Geneva, Switzerland. (Credit: CERN)

Researchers from the University of Wisconsin-Madison and the University of California-Berkeley say that the telltale signatures left by a new class of particles could distinguish between possible shapes of the extra spatial dimensions predicted by string theory.

String theory, which describes the fundamental particles of the universe as tiny vibrating strings of energy, suggests the existence of six or seven unseen spatial dimensions in addition to the time and three space dimensions that we normally see.

Much as the shape of a musical instrument determines its sound, the shape of these dimensions determines the properties and behavior of our four-dimensional universe, says Gary Shiu, lead author of a paper appearing in the Jan. 25 issue of Physical Review Letters.

"The shape of the dimensions is crucial because, in string theory, the way the string vibrates determines the pattern of particle masses and the forces that we feel," says the UW-Madison physics professor.

Zeroing in on that shape should further our understanding and predictions of our four-dimensional world, Shiu says. "There are myriad possibilities for the shapes of the extra dimensions out there. It would be useful to know a way to distinguish one from another and perhaps use experimental data to narrow down the set of possibilities."

Such experimental evidence could appear in data from a new particle accelerator, the Large Hadron Collider, scheduled to begin operating later this year near Geneva, Switzerland.

In an accelerator, smashing atomic nuclei head-on at nearly the speed of light can briefly create new high-energy and highly unstable particles, which quickly decay into a shower of detectable lower energy ones. Characteristic patterns of decay serve as fingerprints of the fleeting exotic particles and, possibly, the shape of the unseen dimensions.

With colleagues Bret Underwood and Kathryn Zurek at UW-Madison and Devin Walker at UC-Berkeley, Shiu shows in the new study that the signature patterns from particles called Kaluza-Klein (KK) gravitons can distinguish between different proposed extra-dimensional geometries.

How" Shiu compares the effect to a darkened room in which patterns of sound resonating off the walls can reveal the shape of the room. Similarly, KK gravitons are sensitive to the extra-dimensional shape and, through their behavior and decay, may reveal clues to that shape.

The current study shows that, in simulations, even small geometric variations lead to visible differences in KK graviton signatures, Underwood says.

Based on these results, Shiu says, "At least in principle, one may be able to use experimental data to test and constrain the geometry of our universe."

Last year, Shiu and Underwood reported that clues to dimensional geometries might also be visible in patterns of cosmic radiation left over from the Big Bang. The new work complements the previous approach, they say.

"The more hints we get, the better idea we have about the underlying physics," says Shiu.

Adds Underwood, "If the cosmology and particle physics data agree, it's an indication we're on the right track."

The work was supported by the National Science Foundation, the U.S. Department of Energy, the Research Corporation, and a University of California Presidential Fellowship.

Adapted from materials provided by University of Wisconsin-Madison.

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Bio-crude Turns Cheap Waste Into Valuable Fuel

Daily Science Journal (Feb. 5, 2008) — CSIRO and Monash University have developed a chemical process that turns green waste into a stable bio-crude oil. The bio-crude oil can be used to produce high value chemicals and biofuels, including both petrol and diesel replacement fuels.

Forest waste can be converted into bio-crude oil. (Credit: Image courtesy of CSIRO Australia)

“By making changes to the chemical process, we’ve been able to create a concentrated bio-crude which is much more stable than that achieved elsewhere in the world,” says Dr Steven Loffler of CSIRO Forest Biosciences.

“This makes it practical and economical to produce bio-crude in local areas for transport to a central refinery, overcoming the high costs and greenhouse gas emissions otherwise involved in transporting bulky green wastes over long distances.”

The process uses low value waste such as forest thinnings, crop residues, waste paper and garden waste, significant amounts of which are currently dumped in landfill or burned.

“By using waste, our Furafuel technology overcomes the food versus fuel debate which surrounds biofuels generated from grains, corn and sugar,” says Dr Loffler.

“The project forms part of CSIRO’s commitment to delivering cleaner energy and reducing greenhouse gas emissions by improving technologies for converting waste biomass to transport fuels.”

The plant wastes being targeted for conversion into biofuels contain chemicals known as lignocellulose, which is increasingly favoured around the world as a raw material for the next generation of bio-ethanol.

Lignocellulose is both renewable and potentially greenhouse gas neutral. It is predominantly found in trees and is made up of cellulose; lignin, a natural plastic; and hemicellulose.

CSIRO and Monash University will apply to patent the chemical processes underpinning the conversion of green wastes to bio-crude oil once final laboratory trials are completed.

The research to date is supported by funding from CSIRO’s Energy Transformed Flagship program, Monash University, Circa Group and Forest Wood Products Australia.

National Research Flagships CSIRO initiated the National Research Flagships to provide science-based solutions in response to Australia’s major research challenges and opportunities. The nine Flagships form multidisciplinary teams with industry and the research community to deliver impact and benefits for Australia.

Adapted from materials provided by CSIRO Australia.

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NASA To Beam Beatles' 'Across The Universe' Into Space

Daily Science Journal (Feb. 5, 2008) — For the first time ever, NASA will beam a song -- The Beatles' "Across the Universe" -- directly into deep space at 7 p.m. EST on Feb. 4.

An estimated 10,000 galaxies are revealed in humankind's deepest portrait of the visible universe ever from the Hubble Space Telescope. (Credit: Image courtesy of NASA)

The transmission over NASA's Deep Space Network will commemorate the 40th anniversary of the day The Beatles recorded the song, as well as the 50th anniversary of NASA's founding and the group's beginnings. Two other anniversaries also are being honored: The launch 50 years ago this week of Explorer 1, the first U.S. satellite, and the founding 45 years ago of the Deep Space Network, an international network of antennas that supports missions to explore the universe.

The transmission is being aimed at the North Star, Polaris, which is located 431 light years away from Earth. The song will travel across the universe at a speed of 186,000 miles per second. Former Beatle Sir Paul McCartney expressed excitement that the tune, which was principally written by fellow Beatle John Lennon, was being beamed into the cosmos.

"Amazing! Well done, NASA!" McCartney said in a message to the space agency. "Send my love to the aliens. All the best, Paul."

Lennon's widow, Yoko Ono, characterized the song's transmission as a significant event.

"I see that this is the beginning of the new age in which we will communicate with billions of planets across the universe," she said.

It is not the first time Beatles music has been used by NASA; in November 2005, McCartney performed the song "Good Day Sunshine" during a concert that was transmitted to the International Space Station. "Here Comes the Sun," "Ticket to Ride" and "A Hard Day's Night" are among other Beatles' songs that have been played to wake astronaut crews in orbit.

Feb. 4 has been declared "Across The Universe Day" by Beatles fans to commemorate the anniversaries. As part of the celebration, the public around the world has been invited to participate in the event by simultaneously playing the song at the same time it is transmitted by NASA. Many of the senior NASA scientists and engineers involved in the effort are among the group's biggest fans.

"I've been a Beatles fan for 45 years – as long as the Deep Space Network has been around," said Dr. Barry Geldzahler, the network's program executive at NASA Headquarters, Washington. "What a joy, especially considering that 'Across the Universe' is my personal favorite Beatles song."

Adapted from materials provided by National Aeronautics and Space Administration.

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Why Serotonin Can Cause Depression And Anxiety

Daily Science Journal (Feb. 5, 2008) — Mood disorders could be caused by a loss of our inherent, reflexive avoidance of aversive events, according to a new study. Researchers from UCL in London and Columbia University in New York used computational modeling techniques to integrate what appeared to be blatant contradictions between serotonin's roles in different states of health.

Serotonin appears to be one of the major players in mood and a variety of other disorders. But exactly how remains an open question. Imagine walking past a dark alleyway in a dangerous part of some city; although it might be a shortcut, most people wouldn't consider taking it. In healthy subjects, serotonin appears important for this automatic avoidance.

It has long been suggested that over-activity of the serotonin system may relate to mood disorders such as depression and anxiety, as these seem characterized by too much withdrawal and avoidance. However, the new modeling study simply suggests that we think about what happens when these reflexes fail--suddenly you have to think hard to avoid things that used to be avoided reflexively You might for example consider walking down the dangerous alley, be robbed and thus be reminded and taught by additional experience that dark alleys are to be avoided.

In this study Prof. Peter Dayan and Dr. Quentin Huys built a reinforcement learning model of reflexive choices. Agents take actions and as a result of these move through a set of states, some of which are rewarded or punished. As agents progress through this space, they learn the value of each state--how much punishment or reward is to be expected from this state onwards.

It turns out that adding to the agent's behavioural repertoire a simple reflex, which guides the agent away from an action with potential for poor consequences, does two things: it increases the rewards reaped overall, but, because bad states are now not explored any more, it also prevents them from learning exactly how bad these bad states are. When serotonin drops, say in depression or anxiety, agents have no more recourse to the reflexive avoidance and have to rely on what they learned. Because they have not learned how bad the bad states are, they start exploring states that don't look too bad to them, but in reality are much worse. Serotonin enhancing drugs, such as Prozac, are then suggested to reinstate the reflexive avoidance, and thus to redress the balance.

This study gives insight into some puzzling findings--for example, it argues that the association of depression with aggression may have to do with a lack of reflexive avoidance of it. In addition, stress not only causes depression, but people with depression experience more stressors. Again, this may be related to a dysfunctional reflexive avoidance system. The study, however, vastly oversimplifies a number of issues, such as the flexibility of reflexive actions, and the effect of non-reflexive action choice. These provide interesting avenues for further research, and may in fact give some insight into the co-morbidity of different mood disorders.

Journal citation: Dayan P, Huys QJM (2008) Serotonin, inhibition, and negative mood. PLoS Comput Biol 4(1): e4. doi:10.1371/journal.pcbi.0040004. http://compbiol.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pcbi.0040004

Adapted from materials provided by PLoS Computational Biology, via EurekAlert!, a service of AAAS.

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Plastic Bottles Release Potentially Harmful Chemicals (Bisphenol A) After Contact With Hot Liquids

Daily Science Journal (Feb. 5, 2008) — When it comes to Bisphenol A (BPA) exposure from polycarbonate plastic bottles, it's not whether the container is new or old but the liquid's temperature that has the most impact on how much BPA is released, according to University of Cincinnati (UC) scientists.

Scott Belcher, PhD, tested polycarbonate plastic bottles like these for Bisphenol A. (Credit: Image courtesy of University of Cincinnati)

Scott Belcher, PhD, and his team found when the same new and used polycarbonate drinking bottles were exposed to boiling hot water, BPA, an environmental estrogen, was released 55 times more rapidly than before exposure to hot water.

"Previous studies have shown that if you repeatedly scrub, dish-wash and boil polycarbonate baby bottles, they release BPA. That tells us that BPA can migrate from various polycarbonate plastics," explains Belcher, UC associate professor of pharmacology and cell biophysics and corresponding study author. "But we wanted to know if 'normal' use caused increased release from something that we all use, and to identify what was the most important factor that impacts release."

"Inspired by questions from the climbing community, we went directly to tests based on how consumers use these plastic water bottles and showed that the only big difference in exposure levels revolved around liquid temperature: Bottles used for up to nine years released the same amount of BPA as new bottles."

BPA is one of many man-made chemicals classified as endocrine disruptors, which alter the function of the endocrine system by mimicking the role of the body's natural hormones. Hormones are secreted through endocrine glands and serve different functions throughout the body.

The chemical--which is widely used in products such as reusable water bottles, food can linings, water pipes and dental sealants--has been shown to affect reproduction and brain development in animal studies.

"There is a large body of scientific evidence demonstrating the harmful effects of very small amounts of BPA in laboratory and animal studies, but little clinical evidence related to humans," explains Belcher. "There is a very strong suspicion in the scientific community, however, that this chemical has harmful effects on humans."

Belcher's team analyzed used polycarbonate water bottles from a local climbing gym and purchased new bottles of the same brand from an outdoor retail supplier.

All bottles were subjected to seven days of testing designed to simulate normal usage during backpacking, mountaineering and other outdoor adventure activities.

The UC researchers found that the amount of BPA released from new and used polycarbonate drinking bottles was the same -- both in quantity and speed of release -- into cool or temperate water.

However, drastically higher levels of BPA were released once the bottles were briefly exposed to boiling water.

"Compared to the rate of release from the same bottle, the speed of release was 15 to 55 times faster," explains Belcher.

Prior to boiling water exposure, the rate of release from individual bottles ranged from 0.2 to 0.8 nanograms per hour. After exposure, rates increased to 8 to 32 nanograms per hour.

Belcher stresses that it is still unclear what level of BPA is harmful to humans. He urges consumers to think about how cumulative environmental exposures might harm their health.

"BPA is just one of many estrogen-like chemicals people are exposed to, and scientists are still trying to figure out how these endocrine disruptors--including natural phyto-estrogens from soy which are often considered healthy--collectively impact human health," he says. "But a growing body of scientific evidence suggests it might be at the cost of your health."

The UC team reports its findings in the Jan. 30, 2008 issue of the journal Toxicology Letters. UC graduate student Hoa Le and summer undergraduate research fellows Emily Carlson and Jason Chua also participated in this study, which was funded by a National Institute of Environmental Health Sciences grant.

Adapted from materials provided by University of Cincinnati.

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Dark Fluid: Dark Matter And Dark Energy May Be Two Faces Of Same Coin

Daily Science Journal (Feb. 5, 2008) — Astronomers at the University of St Andrews believe they can "simplify the dark side of the universe" by shedding new light on two of its mysterious constituents.

The magnificent spiral arms of the nearby galaxy Messier 81. Astronomers believe that both the universe and galaxies are held together by the gravitational attraction of a huge amount of unseen material, now commonly referred to as dark matter. (Credit: NASA/JPL/Caltech/Harvard-Smithsonian Center for Astrophysics)

Dr HongSheng Zhao, of the University's School of Physics and Astronomy, has shown that the puzzling dark matter and its counterpart dark energy may be more closely linked than was previously thought.

Only 4% of the universe is made of known material - the other 96% is traditionally labelled into two sectors, dark matter and dark energy.

A British astrophysicist and Advanced Fellow of the UK's Science and Technology Facilities Council, Dr Zhao points out, "Both dark matter and dark energy could be two faces of the same coin.

"As astronomers gain understanding of the subtle effects of dark energy in galaxies in the future, we will solve the mystery of astronomical dark matter at the same time. "

Astronomers believe that both the universe and galaxies are held together by the gravitational attraction of a huge amount of unseen material, first noted by the Swiss astronomer Fritz Zwicky in 1933, and now commonly referred to as dark matter.

Dr Zhao reports that, "Dark energy has already revealed its presence by masking as dark matter 60 years ago if we accept that dark matter and dark energy are linked phenomena that share a common origin."

In Dr Zhao's model, dark energy and dark matter are simply different manifestations of the same thing, which he has considered as a 'dark fluid'. On the scale of galaxies, this dark fluid behaves like matter and on the scale of the Universe overall as dark energy, driving the expansion of the Universe. Importantly, his model, unlike some similar work, is detailed enough to produce the same 3:1 ratio of dark energy to dark matter as is predicted by cosmologists.

Efforts are currently underway to hunt for very massive dark-matter particles with a variety of experiments. The Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) in Geneva is a particle accelerator that amongst other objectives, could potentially detect dark matter particles.

According to Dr Zhao, these efforts could turn out to be fruitless. He said, "In this simpler picture of universe, the dark matter would be at a surprisingly low energy scale, too low to be probed by upcoming Large Hadron Collider.

"The search for dark-matter particles so far has concentrated on highly-energetic particles. If dark matter however is a twin phenomenon of dark energy, it will not show up at instruments like the LHC, but has been seen over and over again in galaxies by astronomers."

However, the Universe might be absent of dark-matter particles at all. The findings of Dr Zhao are also compatible with an interpretation of the dark component as a modification of the law of gravity rather than particles or energy.

Dr Zhao concluded. "No matter what dark matter and dark energy are, these two phenomena are likely not independent of each other."

Background

Theories of the physics of gravity were first developed by Isaac Newton in 1687 and refined by Albert Einstein’s theory of General Relativity in 1905 which stated that the speed of gravity is equal to the speed of light. However, Einstein was never fully decided on whether his equation should add an omnipresent constant source, now called dark energy in general.

Astronomers following Fred Zwicky have also speculated additional sources to Einstein's equation in the form of non-light emitting material, called dark matter in general. Apart from very light neutrinos neither dark sources have been confirmed experimentally.

Dr Zhao and his collaborators' findings have recently been published by Astrophysical Journal Letters in December 2007, and Physics Review D. 2007.

Adapted from materials provided by Science and Technology Facilities Council.

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DNA Is Blueprint, Contractor And Construction Worker For New Structures

Daily Science Journal (Feb. 4, 2008) — DNA is the blueprint of all life, giving instruction and function to organisms ranging from simple one-celled bacteria to complex human beings. Now Northwestern University researchers report they have used DNA as the blueprint, contractor and construction worker to build a three-dimensional structure out of gold, a lifeless material.

Computer rendition of a structure created by using DNA to assemble nanoparticles into well-defined crystal lattices. (Credit: Northwestern University)

Using just one kind of nanoparticle (gold) the researchers built two common but very different crystalline structures by merely changing one thing -- the strands of synthesized DNA attached to the tiny gold spheres. A different DNA sequence in the strand resulted in the formation of a different crystal.

The technique, to be published in the journal Nature, and reflecting more than a decade of work, is a major and fundamental step toward building functional "designer" materials using programmable self-assembly. This "bottom-up" approach will allow scientists to take inorganic materials and build structures with specific properties for a given application, such as therapeutics, biodiagnostics, optics, electronics or catalysis

Most gems, such as diamonds, rubies and sapphires, are crystalline inorganic materials. Within each crystal structure, the atoms have precise locations, which give each material its unique properties. Diamond's renowned hardness and refractive properties are due to its structure -- the precise location of its carbon atoms.

In the Northwestern study, gold nanoparticles take the place of atoms. The novel part of the work is that the researchers use DNA to drive the assembly of the crystal. Changing the DNA strand's sequence of As, Ts, Gs and Cs changes the blueprint, and thus the shape, of the crystalline structure. The two crystals reported in Nature, both made of gold, have different properties because the particles are arranged differently.

"We are now closer to the dream of learning, as nanoscientists, how to break everything down into fundamental building blocks, which for us are nanoparticles, and reassembling them into whatever structure we want that gives us the properties needed for certain applications," said Chad A. Mirkin, one of the paper's senior authors and George B. Rathmann Professor of Chemistry in the Weinberg College of Arts and Sciences, professor of medicine and professor of materials science and engineering. In addition to Mirkin, George C. Schatz, Morrison Professor of Chemistry, directed the work.

By changing the type of DNA on the surface of the particles, the Northwestern team can get the particles to arrange differently in space. The structures that finally form are the ones that maximize DNA hybridization. DNA is the stabilizing force, the glue that holds the structure together. "These structures are a new form of matter," said Mirkin, "that would be difficult, if not impossible, to make any other way."

He likens the process to building a house. Starting with basic materials such as bricks, wood, siding, stone and shingles, a construction team can build many different types of houses out of the same building blocks. In the Northwestern work, the DNA controls where the building blocks (the gold nanoparticles) are positioned in the final crystal structure, arranging the particles in a functional way. The DNA does all the heavy lifting so the researchers don't have to.

Mirkin, Schatz and their team just used one building block, gold spheres, but as the method is further developed, a multitude of building blocks of different sizes can be used -- with different composition (gold, silver and fluorescent particles, for example) and different shapes (spheres, rods, cubes and triangles). Controlling the distance between the nanoparticles is also key to the structure's function.

"Once you get good at this you can build anything you want," said Mirkin, director of Northwestern's International Institute for Nanotechnology.

"The rules that govern self-assembly are not known, however," said Schatz, "and determining how to combine nanoparticles into interesting structures is one of the big challenges of the field."

The Northwestern researchers started with gold nanoparticles (15 nanometers in diameter) and attached double-stranded DNA to each particle with one of the strands significantly longer than the other. The single-stranded portion of this DNA serves as the "linker DNA," which seeks out a complementary single strand of DNA attached to another gold nanoparticle. The binding of the two single strands of linker DNA to each other completes the double helix, tightly binding the particles to each other.

Each gold nanoparticle has multiple strands of DNA attached to its surface so the nanoparticle is binding in many directions, resulting in a three-dimensional structure -- a crystal. One sequence of linker DNA, programmed by the researchers, results in one type of crystal structure while a different sequence of linker DNA results in a different structure.

"We even found a case where the same linker could give different structures, depending on the temperatures at which the particles were mixed," said Schatz.

Using the extremely brilliant X-rays produced by the Advanced Photon Source synchrotron at Argonne National Laboratory in combination with computational simulations, the research team imaged the crystals to determine the exact location of the particles throughout the structure. The final crystals have approximately 1 million nanoparticles.

"It took scientists decades of work to learn how to synthesize DNA," said Mirkin. "Now we've learned how to use the synthesized form outside the body to arrange lifeless matter into things that are useful, which is really quite spectacular."

The Nature paper, entitled "DNA-programmable nanoparticle crystallization" is to be published January 31, 2008. In addition to Mirkin and Schatz, other authors are Sung Yong Park, a former postdoctoral fellow in Schatz's lab and now at the University of Rochester (lead author); graduate student Abigail K. R. Lytton-Jean, Northwestern University; Byeongdu Lee, Advanced Photon Source, Argonne National Laboratory; and Steven Weigand, Northwestern's DND-CAT Synchrotron Research Center at Argonne's Advanced Photon Source.

Adapted from materials provided by Northwestern University, via EurekAlert!, a service of AAAS.

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New Nanotube Findings Give Boost To Potential Biomedical Applications

Daily Science Journal (Feb. 4, 2008) — Carbon nanotubes-cylinders so tiny that it takes 50,000 lying side by side to equal the width of a human hair-are packed with the potential to be highly accurate vehicles for administering medicines and other therapeutic agents to patients. But a dearth of data about what happens to the tubes after they discharge their medical payloads has been a major stumbling block to progress.

A representation of a carbon nanotube accessorized with a coating of branched PEG. (Credit: Courtesy of Hongjie Dai)

Now, Stanford researchers, who spent months tracking the tiny tubes inside mice, have found some answers.

Studies in mice already had shown that most nanomaterials tend to accumulate in organs such as the liver and spleen, which was a concern because no one knew how long they could linger. But fears that the tiny tubes might be piling up in vital organs, like discarded refrigerators at the bottom of a rural ravine, can now be put to rest, said Hongjie Dai, the J. G. Jackson and C. J. Wood Professor of Chemistry at Stanford, whose research team has demonstrated that the nanotubes exit the organs.

Dai and his group found that the carbon nanotubes leave the body primarily through the feces, with some by way of the urine. ''That's nice to know,'' Dai said. ''This now proves that they do get out of the system.''

The full extent of the news, which is scheduled to be published the week of Jan. 28 in Proceedings of the National Academy of Sciences Online Early Edition (PNAS), is even better than that: The three-month-long study also allays worries that the nanotubes, by simply remaining in the organs for a long time, would prove toxic to the mouse.

''None of the mice died or showed any anomaly in the blood chemistry or in the main organs,'' said Dai, senior author on the PNAS paper. ''They appear very healthy, and they are gaining weight, just like normal mice. There's no obvious toxicity observed.'' The lack of toxicity of nanotubes in mice is consistent with a previous pilot study done by Sanjiv Gambhir, a professor of radiology at Stanford, and his research group in collaboration with Dai's group.

''This is the first time anyone has done a systematic circulation and excretion study like this for nanotubes, and data on other nano particles is also scarce,'' Dai said. ''The excretion pathway may apply to other nano materials and may need to be looked at closely like this also.''

Previous research published by Dai's group has demonstrated the potential for using nanotubes in treating cancerous cells and targeting tumors in mice.

His group used Raman spectroscopy, a method of applying light from a laser beam that effectively ''illuminates'' the presence of the target molecules in the organs of the mice.

Being hit with light from the beam causes a detectable change in the state of a molecule's energy. Carbon nanotubes, composed entirely of carbon atoms that are mostly arranged in linked hexagonal rings, give off a strong signal in response to the beam. This allowed the researchers to pinpoint the position of the chosen molecules, as well as ascertain their abundance in the blood or organs.

Previous detection methods that relied on attaching fluorescent labels or spectroscopic tags to the nanotubes had yielded unreliable results. The attachments tended to either come loose from the tubes or decay over time spans ranging from a few days to only a few hours-far too short to reveal the ultimate fate of the nanotubes.

While knowing the carbon nanotubes will move through the digestive system at a healthy pace is critical to future practical applications, it is also crucial that the nanotubes not enter the digestive system too soon after being injected; they need to spend enough time in the circulatory system to find their way to their target location.

The key to fine-tuning the carbon nanotubes' speed of circulation turns on how the basic, bare-bones floor model is chemically accessorized.

''You can make the nanotubes circulate a very long time in the blood, if the chemistry is done right,'' Dai said. The researchers found that coating their carbon nanotubes with polyethylene glycol (PEG), a common ingredient in cosmetics, worked best.

They used a form of PEG with three little limbs sprouting off a central trunk. ''Those provide better shielding to the nanotube than just a single branch. Therefore, they interact less with the biological molecules around them,'' Dai said.

The team stuffed the PEG liberally into the linked hexagonal rings that compose the nanotubes, prompting Dai to describe the end result as resembling rolled-up chicken wire with feathers sticking out all over.

Though they may sound less than gorgeous visually, the feathery nanotubes turned in a beautiful performance in practical terms, Dai said. The coating of PEG made the nanotubes highly water soluble, which helped them to stay in the blood instead of being absorbed.

''They circulate in the blood for about 10 hours or so in mice, which seems to be a good length of time,'' Dai said.

The right chemical coating on nanotubes also can help ease them out of the mouse in a timely fashion, and the three-branched PEG was effective there, too.

Dai's earlier research demonstrated that nanotubes have promise for treating cancer with two different approaches. Once they have zeroed in on the target cells, shining light on the nanotubes causes them to generate heat, which can kill cancer cells. The other method is to rig the nanotubes to accumulate at targeted sites, where they can deliver medication from within the tubes.

''[Carbon nanotubes] seem to be promising for biomedical applications and for potentially treating cancer, either using drugs or using the physical properties,'' Dai said. ''This is the reason we carried out the study of the fate of nanotubes in mice. I think this is really a very fundamental issue.''

The research was funded by the Cancer Center for Nanotechnology Excellence, which is funded by the National Institutes of Health and the National Cancer Institute. The first author of the PNAS paper is Zhuang Liu, graduate student in chemistry. The paper's other authors, all affiliated with Stanford University, are Xiaoyuan ''Shawn'' Chen, assistant professor in radiology; Dr. Corrine Davis of the Veterinary Service Center in the Department of Comparative Medicine; Weibo Cai, postdoctoral scholar in radiology; and Lina He, formerly a technician in Chen's research group.

Adapted from materials provided by Stanford University.

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White Dwarf Pulses Like A Pulsar

Daily Science Journal (Jan. 3, 2008) — New observations from Suzaku, a joint Japanese Aerospace Exploration Agency (JAXA) and NASA X-ray observatory, have challenged scientists’ conventional understanding of white dwarfs. Observers had believed white dwarfs were inert stellar corpses that slowly cool and fade away, but the new data tell a completely different story.

The white dwarf in the AE Aquarii system is the first star of its type known to give off pulsar-like pulsations that are powered by its rotation and particle acceleration. (Credit: Casey Reed)

At least one white dwarf, known as AE Aquarii, emits pulses of high-energy (hard) X-rays as it whirls around on its axis. "We’re seeing behavior like the pulsar in the Crab Nebula, but we’re seeing it in a white dwarf," says Koji Mukai of NASA Goddard Space Flight Center in Greenbelt, Md. The Crab Nebula is the shattered remnant of a massive star that ended its life in a supernova explosion. "This is the first time such pulsar-like behavior has ever been observed in a white dwarf." Mukai is co-author of a paper presented at a Suzaku science conference in San Diego, Calif., in December.

White dwarfs and pulsars represent distinct classes of compact objects that are born in the wake of stellar death. A white dwarf forms when a star similar in mass to our sun runs out of nuclear fuel. As the outer layers puff off into space, the core gravitationally contracts into a sphere about the size of Earth, but with roughly the mass of our sun. The white dwarf starts off scorching hot from the star’s residual heat. But with nothing to sustain nuclear reactions, it slowly cools over billions of years, eventually fading to near invisibility as a black dwarf.

A pulsar is a type of neutron star, a collapsed core of an extremely massive star that exploded in a supernova. Whereas white dwarfs have incredibly high densities by earthly standards, neutron stars are even denser, cramming roughly 1.3 solar masses into a city-sized sphere. Pulsars give off radio and X-ray pulsations in lighthouse-like beams.

The discovery team, led by Yukikatsu Terada of the Institute of Physical and Chemical Research (RIKEN) in Wako, Japan, was not expecting to find a white dwarf mimicking a pulsar. Instead, the astronomers were hoping to find out if white dwarfs could accelerate charged subatomic particles to near-light speed, meaning they could be responsible for many of the cosmic rays that zip through our galaxy and occasionally strike Earth.

Some white dwarfs, including AE Aquarii, spin very rapidly and have magnetic fields millions of times stronger than Earth’s. These characteristics give them the energy to generate cosmic rays.

To find out if this is happening, Terada and his colleagues targeted AE Aquarii with Suzaku in October 2005 and October 2006. The white dwarf resides in a binary system with a normal companion star. Gas from the star spirals toward the white dwarf and heats up, giving off a glow of low-energy (soft) X-rays. But Suzaku also detected sharp pulses of hard X-rays. After analyzing the data, the team realized that the hard X-ray pulses match the white dwarf’s spin period of once every 33 seconds.

The hard X-ray pulsations are very similar to those of the pulsar in the center of the Crab Nebula. In both objects, the pulses appear to be radiated like a lighthouse beam, and a rotating magnetic field is thought to be controlling the beam. Astronomers think that the extremely powerful magnetic fields are trapping charged particles and then flinging them outward at near-light speed. When the particles interact with the magnetic field, they radiate X-rays.

"AE Aquarii seems to be a white dwarf equivalent of a pulsar," says Terada. "Since pulsars are known to be sources of cosmic rays, this means that white dwarfs should be quiet but numerous particle accelerators, contributing many of the low-energy cosmic rays in our galaxy."

Launched in 2005, Suzaku is the fifth in a series of Japanese satellites devoted to studying celestial X-ray sources. Managed by JAXA, this mission is a collaborative effort between Japanese universities and institutions and Goddard.

Adapted from materials provided by NASA/Goddard Space Flight Center.

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Finding New Oil In Long-exhausted Oil Wells

Daily Science Journal (Feb. 3, 2008) — Under contemporary conditions, it is more economically sound not to look for new oil fields but to overhaul old ones. Oil reappears from time to time in old deposits and long ago exhausted oil wells.

The earth's crust is similar to a sandwich cake, consisting of hard layers and fractured-porous layers saturated by various fluids, including oil. In some places, the crust is penetrated by an extremely dense network of fissures and ruptures. Ruptures form cavities located almost horizontally and united into a network. All this complicated system is in constant motion due to tectonic forces’ action. The layers are moving, fissures are widening and acting as a rubber bulb: liquid starts coming into formed interstice from surrounding porous layers. In case of significant tectonic tensions, liquid moves at large distances.

This phenomenon attracts attention of multiple researchers. Specialists of the Institute of Oil and Gas Problems under the guidance of Academician Dmitrievsky offer their explanation.

According to the researchers’ opinion, this mechanism of liquid movement in the crust is the most intense and universal among all possible ones. It acts both in ruptures and in thin fractured layers, which stretch at significant distances. Vibrations in the crust drive fluids along all possible directions, including horizontal and even downward directions. Migration occurs along lengthy cavities and fractures systems, located at the depth of 10 to 15 kilometers.

Liquid movement caused by widening of internal cavities is of vibrating character. Oil sometimes rushes in or sometimes floods back. The mode and period of vibration depend on the size of perturbed area. In large porous layers, the vibration period makes about 10 thousand years. In the ruptures, the period is shorter and it varies from a thousand to hundreds and even dozens of years, if rupture zones are located at small depths.

The researchers have investigated the carbohydrates migration process from the petroliferous stratum into the upper layers in several regions. An example can be the Romashinskoye oilfield in Tatarstan. The volume of produced oil there has significantly exceeded the previously asserted reserves. According to the TATANEFT Joint Stock Company’s data, more than 65% of oil in Tatarstan is produced in old oilfields exhausted by 80%. However, supplementary exploration of the known deposits allowed to increment reserves of oil by one and a half times within the last 25 years. In the Romashinskoye oilfield, the researchers also discovered old exhausted drillings with regenerated inflow of oil and oil with water.

The space of oil pools and their reserves increase with increasing rupture network density. It is interesting to note that the depth of sedimentary covering in the zone of the gigantic Romashinskoye oilfield does not exceed 2 kilometers on average, and this mantle does not possess significant oil potential. Most likely, oil cames to these locations from the direction of Pre-Ural downfold.

In the researchers’ opinion, to overhaul old oil deposits is currently much more profitable and efficient than expensive geological exploration works at new locations.

Adapted from materials provided by Informscience.

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Swarm Approach To Photography Improves Contrast And Detail In Digital Photos

Daily Science Journal (Feb. 3, 2008) — A new approach to cleaning up digital photos and other images has been developed by researchers in the UK and Jordan. The method uses a computer algorithm known as a PSO (Particle Swarm Optimization) to intelligently boost contrast and detail in an image without distorting the underlying features.

Malik Braik and Alaa Sheta of the Department of Information Technology, at Al-Balqa Applied University, in Salt, Jordan, working with Aladdin Ayesh in the Division of Computer Engineering, at De Montfort University, Leicester, UK, explain that the Particle Swarm Optimization (PSO) algorithm represents an entirely new approach to solving all kinds of optimization problems. PSO has recently been used in computer science and electrical engineering.

The roots of the PSO algorithms lie in Swarm Intelligence paradigm which is inspired by models of living systems, artificial life (A-life) in general, and by theories of how and why birds flock, why schools of fish behave the way they do and in particular what controls swarming insects. Despite its potential it relies on only simple mathematics and does not need powerful computers to run, which means software applications based on PSO would not be limited only to academic researchers and those with access to supercomputers.

There have been several approaches to image enhancement developed by image manipulation software companies and others. However, none comes up to the standards of the kind of image enhancement often seen in fiction, where a blurry distorted image on a screen is rendered pin-sharp at the click of a mouse. PSO, however, takes image enhancement a step closer to this ideal.

PSO is based on a mathematical model of the social interactions of swarms. The algorithm treats each version of an image as an individual member of the swarm and makes a single, small adjustment to contrast levels, edge sharpness, and other image parameters. The algorithm then determines whether the new members of the swarm are better or worse than the original according to an objective fitness criterion.

"The objective of the algorithm is to maximize the total number of pixels in the edges, thus being able to visualize more details in the images," explain the researchers. Such enhancement might be useful in improving snapshots of CCTV quality for identification of individuals or vehicle number plates, it might also have application in improving images produced with lower quality cameras, such as camera phones, that are required for use in publishing or TV where image quality standards are usually higher.

The process of enhancing step by step is repeated to create a swarm of images in computer memory which have been graded relative to each other, the fittest end up at the front of the swarm until a single individual that is the most effectively enhanced.

"The obtained results using grey scale images indicate that PSO is better than other approaches in terms of the computational time and both the objective evaluation and maximization of the number of pixels in the edges of the tested images," they add.

This research was published recently in Inderscience's International Journal of Innovative Computing and Applications.

Adapted from materials provided by Inderscience Publishers, via EurekAlert!, a service of AAAS.

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Supernova Surprise: Black Holes May Pull Apart, Reignite White Dwarf Stars

Daily Science Journal (Feb. 2, 2008) — A strange and violent fate awaits a white dwarf star that wanders too close to a moderately massive black hole. According to a new study, the black hole's gravitational pull on the white dwarf would cause tidal forces sufficient to disrupt the stellar remnant and reignite nuclear burning in it, giving rise to a supernova explosion with an unusual appearance. Observations of such supernovae could confirm the existence of intermediate-mass black holes, currently the subject of much debate among astronomers.

This series of images shows the interaction of a white dwarf star with a black hole. As it passes the black hole, the white dwarf becomes strongly compressed and heated (top left), triggering an explosion. Most of the stellar mass is ejected into space (the "bubble" in the upper right part of the debris in the top right image), while the rest (the cusp-like part of the image) falls toward the black hole. While the ejected matter expands rapidly, the infalling matter builds a violent, thick accretion disk around the black hole. (Credit: Image courtesy of University of California - Santa Cruz)

"Our supercomputer simulations show a peculiar supernova that would be a unique signature of an intermediate-mass black hole," said Enrico Ramirez-Ruiz, assistant professor of astronomy and astrophysics at the University of California, Santa Cruz.

Ramirez-Ruiz and his collaborators--Stephan Rosswog of Jacobs University in Bremen, Germany, and William Hix of Oak Ridge National Laboratory--used detailed computer simulations to follow the entire process of tidal disruption of a white dwarf by a black hole. Their simulations included gas dynamics, gravity, and nuclear physics, requiring weeks of computer time to simulate events that would take place in a fraction of a second.

"Every star that is not too massive ends up as a white dwarf, so they are very common. We were interested in whether tidal disruption can bring this stellar corpse to life again," said Rosswog, the first author of the paper.

A white dwarf can explode as a "type Ia" supernova if it accumulates enough mass by siphoning matter away from a companion star. When it reaches a critical mass (about 1.4 times the mass of the Sun), the white dwarf collapses and explodes. Astronomers use these type Ia supernovae as "standard candles" for cosmic distance measurements because their brightness evolves over time in a predictable manner.

The new paper* describes a distinctly different mechanism for igniting a white dwarf, in which tidal disruption by a black hole causes drastic compression of the stellar material. The white dwarf is flattened into a pancake shape aligned in the plane of its orbit around the black hole. As each section of the star is squeezed through a point of maximum compression, the extreme pressure causes a sharp increase in temperatures, which triggers explosive burning.

The explosion ejects more than half of the debris from the disrupted star, while the rest of the stellar material falls into the black hole. The infalling material forms a luminous accretion disk that emits x-rays and should be detectable by the Chandra X-ray Observatory, the researchers said.

"This is a new mechanism for ignition of a white dwarf that results in a very different type of supernova than the standard type Ia, and it is followed by an x-ray source," Ramirez-Ruiz said.

He estimated that this type of event would occur about 100 times less frequently than the standard type Ia supernovae, but should be detectable by future surveys designed to observe large numbers of supernovae. The Large Synoptic Survey Telescope (LSST), planned for completion in 2013, is expected to discover hundreds of thousands of type Ia supernovae per year.

"These exotic creatures will start showing up in the data from the LSST," Ramirez-Ruiz said. "We want to predict the light curves so we can look for them in the survey data."

The mechanism described in the paper requires a black hole that is neither too small nor too big. Such intermediate-mass black holes (500 to 1,000 times the mass of the Sun) may reside in some globular star clusters, but there is much less evidence for their existence than there is for the relatively small stellar black holes (tens of times the mass of the Sun) or for supermassive black holes (a few million times the mass of the Sun), found at the centers of galaxies.

The new paper describes in detail the disruption of a white dwarf with two-tenths the mass of the Sun by a black hole 1,000 times the mass of the Sun. The researchers also found that they can vary the mass of the white dwarf and still get the same outcome--tidal disruption and ignition of the white dwarf.

"We can ignite the whole mass range of white dwarfs if they get close enough to the black hole," Rosswog said.

*A paper describing their results has been accepted for publication in Astrophysical Journal Letters, and a preprint is currently available online.

This research was supported by the Department of Energy's Program for Scientific Discovery through Advanced Computing.

Adapted from materials provided by University of California - Santa Cruz.

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New Polymer Could Improve Semiconductor Manufacturing, Packaging

Daily Science Journal (Feb. 2, 2008) — Researchers at Rensselaer Polytechnic Institute and Polyset Company have developed a new inexpensive, quick-drying polymer that could lead to dramatic cost savings and efficiency gains in semiconductor manufacturing and computer chip packaging.

Researchers from Rensselaer Polytechnic Institute's Department of Physics and Center for Integrated Electronics have developed a new inexpensive, quick-drying polymer that could lead to dramatic cost savings and efficiency gains in semiconductor manufacturing and computer chip packaging. In this series of scanning electron microscope images of the new PES polymer in a UV-imprint lithography application, the well-defined pattern indicates the material’s potential for use in next-generation chip making techniques. (Credit: Rensselaer Polytechnic Institute)

Along with allowing enhanced performance and cost savings for conventional photolithography processes, the new material, called polyset epoxy siloxane (PES), should also enable a new generation of lower-cost, on-chip nanoimprinting lithography technology, according to the researchers.

"With this new material, chip manufacturers will be able to trim several steps from their production and packaging processes, and in turn realize a cost savings," said Toh-Ming Lu, the R.P. Baker Distinguished Professor of Physics at Rensselaer, who oversaw the study. "PES is cheaper and more reliable."

The widely adopted technique of photolithography involves using a mix of light and chemicals to generate intricate micro- and nano-scale patterns on tiny areas of silicon. As part of the process, a thin polymer film -- called a redistribution layer, and crucial to the effectiveness of device -- is deposited onto the silicon wafer, in order to ease the signal propagation delay and to protect the chip from different environmental and mechanical factors.

The new PES material developed by Lu's group and Polyset Company is one such thin polymer film, and it offers several advantages over the incumbent materials typically used in the semiconductor manufacturing industry. In addition, their new PES material can also be used as a thin polymer film for ultraviolet (UV) on-chip nanoimprinting lithography technology, which is still in the early phases of development. The consistency of using PES in conventional technology, and then continuing to use PES while academia and industry test and gradually migrate to the next generation of devices, should help ease the transition, Lu said.

"Having the ability to use one material -- our new PES -- for both photolithography and imprint will be very attractive to manufacturers," Lu said. "At its core, our project is basic research, but it also has important industry implications. It's very exciting."

Manufacturers today typically use benzocyclobutene and polyimide as polymers for redistribution layers, because of their low water absorption, thermal stability, low curing temperature, low thermal expansion, low dielectric constant, and low leakage current. Lu said PES offers significant advantages to these materials, particularly in the areas of cure temperature and water uptake.

PES cures, or dries and hardens, at 165 degrees Celsius, about 35 percent cooler than the other two materials. The need for less heat should translate directly into lower overhead costs for manufacturers, Lu said. Another advantage of PES is its low water uptake rate of less than 0.2 percent, less than the other materials. Additionally, PES adheres well to copper and can easily be made less brittle if needed. All of these attributes make PES a promising candidate for redistribution layer application and UV imprint lithography.

"The results demonstrate that PES is feasible to be used as UV-curable resist for both the redistribution application for electronic packaging and micro/nano imprint lithography," said Rensselaer Research Associate Pei-I Wang, co-author of the new paper, published recently in the Journal of Vacuum Science and Technology B.

Along with photolithography and on-chip nanoimprinting lithography, PES holds the potential for applications in other optical devices, flat-panel display, biotechnology devices, and microelectromechanical systems, Wang said.

In addition to Lu and Wang, co-authors on the paper include Rensselaer materials science and engineering professor Omkaram Nalamasu, who is also chief technical officer of Applied Materials Inc. in Santa Clara, Calif.; Rajat Ghoshal and Ram Ghoshal of Polyset Co. Inc. in Mechanicville, N.Y.; Charles Schaper of Transfer Devices Inc. in Santa Clara, Calif.; and Andrew Li of Applied Materials.

The project was funded through the New York State Foundation for Science, Technology and Innovation.

Adapted from materials provided by Rensselaer Polytechnic Institute.

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New Method For Creating Self-Assembling, Nanoscale Materials

Daily Science Journal (Feb. 2, 2008) — While biomedical, electronics, and other branches of research are marching steadily into the realm of the smaller-than-small nanometer scale, building needed materials at this scale has been problematic.

Recently, however, a team from The Scripps Research Institute unveiled a novel approach to the problem that yields a material with novel properties, which some might find reminiscent of Flubber. The material is produced using naturally occurring proteins as templates for uniform, self-assembled, nano-scale construction.

The material, an organic polymer described in today's early, online edition of the Proceedings of the National Academy of Sciences (PNAS), could one day find application in everything from screening for disease to microelectronics.

Using Nature's Tricks

Nature is replete with examples of molecules such as DNA that self-assemble with uniform patterns on the nanoscale, but until now researchers have had limited success duplicating such processes. The new study, however, provides one synthetic method that has effectively mimicked the templating strategy used in nature for nanoscale construction in the lab.

To create the new material, the Scripps Research team, led by Scripps Research President Richard Lerner and Assistant Professor Tobin Dickerson, began with a natural nanoscale product, a bacterial virus or phage. A nanometer is one billionth of a meter, or the width of a few average atoms.

Specifically, the product the team worked with was a phage known as M13. If scaled up, the phage is proportionally equivalent to a 4-foot-long pencil, with the tip and eraser roughly representing the active parts of the phage that infect bacteria. Other proteins that are biologically inert and analogous to the wood body of the pencil provide the filamentous phage's structure.

Having worked with phage extensively in other applications, the team decided to explore the possibility of using those structural proteins as a potential template for nanoscale construction. To do so, the team chemically modified molecular protrusions on the proteins so they would attract and bind with the components needed to form strands of polyacrylamide, a common polymer used to make laboratory gels.

The resulting polymer-phage combination, which twists into helices like DNA and RNA molecules, takes on the shape of a comb with the polymers as the teeth. These teeth in turn interlock to form a strangely resilient, rubbery solid.

Shocking Flexibility

Once the new material, known as a protein-polymer bioconjugate, was created, the group was shocked to find that it was almost impossible to break a sample apart. It could be sliced, but no matter how hard researchers compressed or squeezed it, it always bounced back to its original state, because the stable phage proteins act like rebar in concrete to provide strength.

Further analyses uncovered additional important characteristics. The combs do not grow completely uniformly—some combs grow more teeth than others, for instance, before interlocking with a nearby comb. But the combs can only be a prescribed distance apart for the chemical interlocking to occur, which leads to uniform size for the pores between the comb teeth. The pores proved to be about 4 nanometers wide and greater than 1 micrometer (one millionth of a meter) in length.

This uniformity is in stark contrast with experiments which showed that simply mixing the phages with polymers without the templating procedure produces a chaotic hodge podge at the molecular level.

Interestingly, after creating the material, the group discovered that a British scientist had done theoretical calculations about how flexible rods—like the phages—would pack together using the least amount of energy.

"It was extremely gratifying to see that the mathematics had exactly predicted what we were observing," says Dickerson

Putting It to Use

Although the work was intended mainly as a proof of concept for using the phages as templates, the researchers have a number of potential applications in mind. The phage can be produced easily and cheaply in very large quantities, and the polymer components are readily available and simple to combine to create the final material. These characteristics would make commercial application possible.

"In essence, bacteriophage-derived materials are a renewable resource," says Dickerson.

The defined channels established by the pores in the material might be adapted as pathways for electrons for use in microelectronics. Or, the pores might be used as a filter for certain molecules, for example to test blood samples for proteins whose presence is tied to particular diseases. More complex potential uses might include altering the biologically active portions of the phage to attract specific molecules, forcing them into the polymers' pores, or to block others.

"These tools can be visualized like Tinkertoys ® or Legos ®," says Dickerson of the possibilities. "You can think about this really in engineering terms using macroscopic analogs such as baskets, or lids, or holes."

To add to the list of potential applications, the team has already begun exploring additional materials that might be created using the basic phage construction scheme.

In addition to Dickerson and Lerner, authors on the paper, entitled "Biologically templated organic polymers with nanoscale order," were Bert Willis, Lisa Eubanks, Malcolm Wood, and Kim Janda, all of Scripps Research. See http://www.pnas.org/cgi/content/abstract/0711308105v1.

The work was supported by the Skaggs Institute for Chemical Biology, Worm Institute for Research and Medicine, and a National Institutes of Health Kirschstein National Research Service Award.

Adapted from materials provided by Scripps Research Institute.

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Virtual Human In HIV Drug Simulation

Daily Science Journal (Feb. 2, 2008) — The combined supercomputing power of the UK and US ‘national grids’ has enabled UCL (University College London) scientists to simulate the efficacy of an HIV drug in blocking a key protein used by the lethal virus. The method – an early example of the Virtual Physiological Human in action – could one day be used to tailor personal drug treatments, for example for HIV patients developing resistance to their drugs.

The study ran a large number of simulations to predict how strongly the drug saquinavir would bind to three resistant mutants of HIV-1 protease, a protein produced by the virus to propagate itself. These protease mutations are associated with the disease’s resistance to saquinavir, an HIV-inhibitor drug.

The study, by Professor Peter Coveney and colleagues at the UCL Department of Chemistry, involved a sequence of simulation steps, performed across several supercomputers on the UK’s National Grid Service and the US TeraGrid, which took two weeks and used computational power roughly equivalent to that needed to perform a long-range weather forecast.

The idea behind the Virtual Physiological Human (VPH) is to link networks of computers across the world to simulate the internal workings of the human body. The VPH – mainly a research initiative at present – allows scientists to simulate the effects of a drug and see what is happening at the organ, tissue, cell and molecular level.

Although nine drugs are currently available to inhibit HIV-1 protease, doctors have no way of matching a drug to the unique profile of the virus as it mutates in each patient. Instead, they prescribe a course of drugs and then test whether these are working by analysing the patient’s immune response. One of the goals of VPH is for such ‘trial and error’ methods to eventually be replaced by patient-specific treatments tailored to a person’s unique genotype.

Professor Peter Coveney says: “This study represents a first step towards the ultimate goal of ‘on-demand’ medical computing, where doctors could one day ‘borrow’ supercomputing time from the national grid to make critical decisions on life-saving treatments.

“For example, for an HIV patient, a doctor could perform an assay to establish the patient’s genotype and then rank the available drugs’ efficacy against that patient’s profile based on a rapid set of large-scale simulations, enabling the doctor to tailor the treatment accordingly.

“We have some difficult questions ahead of us, such as how much of our computing resources could be devoted to helping patients and at what price. At present, such simulations – requiring a substantial amount of computing power – might prove costly for the National Health Service, but technological advances and those in the economics of computing would bring costs down.”

For the moment, Professor Coveney’s group is continuing to look at all the protease inhibitors in a similar way. The VPH initiative, now underway with 72 million euros of initial funding from the EU, will boost collaboration between clinicians and scientists to explore the scope for patient-specific medical treatments based on modern modelling and simulation methods.

Journal reference: ‘Rapid and Accurate Prediction of Binding Free Energies for Saquinavir-Bound HIV-1 Proteases’, by Ileana Stoica, S. Kashif Sadiq, and Peter V. Coveney, is published online in the Journal of the American Chemical Society on Tuesday 29 January 2008.

The study was partially funded by the EPSRC, the EU-supported ViroLab project and the National Science Foundation. The UK National Grid Service also provided access to their resources and support for this project.

Adapted from materials provided by University College London.

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Making Accurate Predictions Of Tsunami Risks

Daily Science Journal (Feb. 2, 2008) — A new review of tsunami hazards concludes that the 2004 catastrophe was far from the worst possible in many Indian Ocean borderlands - and notes that warning systems to guard at-risk populations are still lagging.

Wave patterns generated by an earthquake just west of the Indonesian island of Sumatra. (Credit: Image courtesy of University of Southern California)

Costas Synolakis, director of the University of Southern California Tsunami Research Center is co-author of "Far-Field Tsunami Hazard From Mega-Thrust Earthquakes in the Indian Ocean," just published in the Geophysical Journal International.

Synolakis and co-author Emile Okal of Northwestern University evaluated all known potential tsunami-generating sources in the vast area between Africa, Asia, Australia and Antarctica, and then calculated the impact of the tsunamis they can generate, should they rupture. Their paper presents the geographical distribution of risk.

The pair examined eight scenarios, two along Southern Sumatra (in Indonesia), two in the North Andaman segment of the Sumatra Subduction Zone, two sources along the Makran Subduction Zone (south of western Pakistan) and two sources south of Java. (Indonesia)

According to Synolakis, a professor in the USC Viterbi School of Engineering's Sonny Astani Department of Civil and Environmental Engineering, "the most important lesson from the scenarios we investigated is that the patterns of far-field maximum amplitudes predicted by our simulations will not be a repeat of those observed in 2004." The differences result from differences in the directions in which the disturbances propagate, "and in many instances the results are counterintuitive."

Synolakis expressed high confidence in the reliability of the projections. "Even if the earthquakes, as they materialize in the future, have geometric characteristics that are slightly different from our hypothetical scenarios, the far field impact projections are robust to small initial perturbations arising from uncertainty in the rupture characteristics."

Among the paper's conclusions:

• The impact in the mid-ocean Maldive Islands from all scenarios appears to be similar or less than what was observed in 2004 - however the low-lying structure of the islands makes them more difficult to evacuate than other risk sites..
• The impact in Madagascar and the Mascarene Islands (Mauritius, Rodrigues and Réunion) and the Seychelles could be far greater than in 2004, particularly from earthquakes in Southern Sumatra and in South Java. Madagascar is found particularly vulnerable from South Sumatran tsunamis.
• Africa suffered in excess of 300 deaths in 2004, 300 of them in Somalia. Its east coast is vulnerable from south Sumatran tsunamis and in particular, Somalia remains at high risk due to the focusing effect of the Maldives ridge. The Comoro islands located between Tanzania and Madagascar would probably be affected more severely than in 2004.
• Large earthquakes in south Java would generate substantial levels of destruction in Northern Australia, despite the sparse level of development there.
• The Strait of Malacca area appears more vulnerable than in 2004, from earthquakes in the North Andaman. Bali and Lombok and could be severely affected by large events in south Java. In fact Bali was affected by the 1994 tsunami, whose trigger was smaller than the ones envisioned here.
• The Kerguelen Islands (49.5◦S; 69.5◦E), part of the French Southern and Antarctic Territories, are highly vulnerable. Other than the North Andaman scenarios, practically all other events affect the Kerguelens, where apparently the 2004 tsunami did not cause damage. The much larger offshore heights the simulations predict would put the scientific base there (60-100 persons) at risk

Many of these scenarios have never been examined before. Synolakis' USC colleague Jose Borrero and others examined the local impact from south Sumatran scenarios in a 2006 paper in the Proceedings of the National Academy of Sciences. Synolakis and Okal concentrated on basin-wide impacts not studied earlier.

The impact to the eastern coast of India and in Myanmar and Bangladesh from the North Andaman scenarios was examined in a paper recently published in Nature by Phil Cummins (2007) of Geoscience Australia. The impact the new paper predicts is slightly different, Synolakis says, but only in the geographical distribution of the carnage.

According to that paper, the Makran Coast of Baluchistan constitutes a subduction zone along which the Arabian plate sinks under the Eurasian one. This was the site of a major earthquake on 1945 November 27, which was accompanied by a significant regional tsunami, with run-up in the five to ten meter range.

Synolakis and Okal, who is a professor in Northwestern's Department of Earth and Planetary Science, examined different rupture scenarios and their affect on the Makran coast, Oman and the west coast of India. "They are substantial and need more detailed study," Synolakis said, making reference to a documented catastrophe that occurred 24 centuries ago: "While the tsunami impact could be inferred from Pliny's reports of the adventure sof the fleet of Alexander the Great returning from India at the Straits of Hormuz in 434 AD, it has not yet been examined to the extent it deserves given the commercial and military value of the Straits.

Synolakis and Okal agree with Cummins about a critical need for the area: a warning net.

"It is quite clear that a tested and true tsunami early warning system as now works in the Pacific by the Pacific Tsunami Warning Center needs to be urgently implemented in the Indian Ocean," said Synolakis. "This system should include hundreds of pre-computed detailed scenarios of inundation for all Indian Ocean nations to facilitate emergency planning for evacuation should any of these scenarios materialize. Public education is a must and local people and visitors should be made aware of tsunami hazards, no matter how unlikely they may be, just us Hawaii and Oregon are already doing."

Synolakis and Okal began work on the project almost in the immediate aftermath of Sumatra 2004 and was completed last year.

"Our work was triggered from three different two week classes we taught for UNESCO in 2006/2007 on tsunami hazard mitigations in the Indian Ocean," said Synolakis. "More than eighty professionals attended having been nominated by their governments and we tried to show them how to assess with us the local impact from adjacent sources. We tried to guide them towards understanding and evaluating transoceanic impact, but the computational tools they had then were just not optimal.

"The work we present here extends the synthesis of hundreds of inundation projections done by our students in these classes, with varying degrees of success. However, all the specific scenarios we used are the synthesis of extensive literature and archive review, a synthesis of the preliminary material we developed in the UNESCO classes and of course all the computations are new."

The National Science Foundation and the European Union - via a Transfer Grant - supported the research.

Adapted from materials provided by University of Southern California.

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Researchers Create Gold Aluminum, Black Platinum, Blue Silver Using Tabletop Laser

Daily Science Journal (Feb. 2, 2008) — Using a tabletop laser, University of Rochester optical scientists have turned pure aluminum, gold. And blue. And gray. And many other colors. And it works for every metal tested, including platinum, titanium, tungsten, silver, and gold.

Gold Aluminum, Blue Titanium, Gold Platinum. (Credit: Richard Baker, University of Rochester)

Chunlei Guo, the researcher who a year ago used intense laser light to alter the properties of a variety of metals to render them pitch black, has pushed the same process further in a paper in today's Applied Physics Letters. He now believes it's possible to alter the properties of any metal to turn it any color—even multi-colored iridescence like a butterfly's wings.

Since the process changes the intrinsic surface properties of the metal itself and is not just a coating, the color won't fade or peel, says Guo, associate professor of optics at the Institute of Optics at the University of Rochester. He suggests the possibilities are endless—a cycle factory using a single laser to produce bicycles of different colors; etching a full-color photograph of a family into the refrigerator door; or proposing with a gold engagement ring that matches your fiancée's blue eyes.

"Since the discovery of the black metal we've been determined to get full control on getting metals to reflect only a certain color and absorb the rest, and now we finally can make a metal reflect almost any color we wish," says Guo. "When we first found the process that produced a gold color, we couldn't believe it. We worked in the lab until midnight trying to figure out what other colors we could make."

Guo and his assistant, Anatoliy Vorobeyv, use an incredibly brief but incredibly intense laser burst that changes the surface of a metal, forming nanoscale and microscale structures that selectively reflect a certain color to give the appearance of a specific color or combinations of colors.

The metal-coloring research follows up on Guo's breakthrough "black metal" discovery in late 2006, when his research team was able to create nanostructures on metal surfaces that absorbed virtually all light, making something as simple as regular aluminum into one of the darkest materials ever created.

Guo's black metal, with its very high absorption properties, is ideal for any application where capturing light is desirable. The potential applications range from making better solar energy collectors, to more advanced stealth technology, he says. The ultra-brief/ultra-intense light Guo uses is produced by a femtosecond laser, which produces pulses lasting only a few quadrillionths of a second. A femtosecond is to a second what a second is to about 32 million years. During its brief burst, Guo's laser unleashes as much power as the entire electric grid of North America does, all focused onto a spot the size of a needlepoint.

The intense blast forces the surface of the metal to form nanostructures—pits, globules, and strands that response incoming light in different ways depending on the way the laser pulse sculpted the structures. Since the structures are smaller than the wavelength of light, the way they reflect light is highly dependent upon their specific size and shape, says Guo. Varying the laser intensity, pulse length, and number of pulses, allows Guo to control the configuration of the nanostructures, and hence control what color the metal reflects.

Guo and Vorobyev also achieve the iridescent coloring by creating microscale lines covered with nanostructures. The lines, arranged in regular rows, cause reflected light of different wavelengths to interfere differently in different directions. The result is a piece of metal that can appear solid purple from one direction, and gray from another, or multiple colors all at once.

To alter an area of metal the size of a dime currently takes 30 minutes or more, but the researchers are working on refining the technique. Fortunately, despite the incredible intensity involved, the femtosecond laser can be powered by a simple wall outlet, meaning that when the process is refined, implementing it should be relatively simple.

The new process has worked on every metal Guo has tried, and the results are so consistent that he believes it will work for every metal known. His team is currently working to find the right tuning to create the rest of the rainbow for the solid-colored metal, including red and green.

Adapted from materials provided by University of Rochester.

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'The Spider' On Mercury: MESSENGER Spacecraft Streams Back Surprises

Daily Science Journal (Feb. 2, 2008) — The recent flyby of Mercury by NASA's MESSENGER spacecraft has given scientists an entirely new look at a planet once thought to have characteristics similar to those of Earth's moon. Researchers are amazed by the wealth of images and data that show a unique world with a diversity of geological processes and a very different magnetosphere from the one discovered and sampled more than 30 years ago.

The Spider: MESSENGER obtained high-resolution images of the floor of the Caloris basin on January 14, 2008. Near the center of the basin, this remarkable feature -- nicknamed "the spider" by the science team -- was revealed. A set of troughs radiating outward are interpreted to be the result of the breaking apart of the floor materials that filled the Caloris basin after its formation. Other troughs near the center form a polygonal pattern. An impact crater about 40 km (~25 miles) in diameter appears to be centered on "the spider." (Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington)

After a journey of more than 2 billion miles and three and a half years, NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft made its first flyby on Jan. 14. MESSENGER is the first mission sent to orbit the planet closest to our sun. The spacecraft's cameras and other sophisticated, high-technology instruments collected more than 1,200 images and made other science observations. Data included the first up-close measurements of Mercury since the Mariner 10 spacecraft's third and final flyby on March 16, 1975.

"This flyby allowed us to see a part of the planet never before viewed by spacecraft, and our little craft has returned a gold mine of exciting data," said Sean Solomon, MESSENGER's principal investigator, Carnegie Institution of Washington. "From the perspectives of spacecraft performance and maneuver accuracy, this encounter was near-perfect, and we are delighted that all of the science data are now on the ground."

Unlike the moon, MESSENGER showed that Mercury has huge cliffs with structures snaking up hundreds of miles across the planet's face. These cliffs preserve a record of patterns of fault activity from early in the planet's history. The spacecraft also revealed impact craters that appear very different from lunar craters.

Instruments provided a topographic profile of craters and other geological features on the night side of Mercury. The spacecraft also discovered a unique feature that scientists dubbed "The Spider." This formation never has been seen on Mercury before and nothing like it has been observed on the moon. It lies in the middle of a large impact crater called the Caloris basin and consists of more than one hundred narrow, flat-floored troughs radiating from a complex central region.

"The Spider has a crater near its center, but whether that crater is related to the original formation or came later is not clear at this time," said James Head, science team co-investigator at Brown University, Providence, R.I.

Now that MESSENGER has shown scientists the full extent of the Caloris basin, its diameter has been revised upward from the Mariner 10 estimate of 800 miles to perhaps as large as 960 miles from rim to rim. The plains inside the Caloris basin are distinctive and more reflective than the exterior plains. Impact basins on the moon have opposite characteristics.

The magnetosphere and magnetic field of Mercury during the MESSENGER flyby appeared to be different from the Mariner 10 observations. MESSENGER found the planet's magnetic field was generally quiet but showed several signatures indicating significant pressure within the magnetosphere.

Magnetic fields like Earth's and their resulting magnetospheres are generated by electrical dynamos in the form of a liquid metallic outer core deep in the planet's center. Of the four terrestrial planets, only Mercury and Earth exhibit such a phenomenon. The magnetic field deflects the solar wind from the sun, producing a protective bubble around Earth that shields the surface of our planet from those energetic particles and other sources farther out in the galaxy. Similar variations are expected for Mercury's magnetic field, but the precise nature of its field and the time scales for internal changes are unknown. The next two flybys and the yearlong orbital phase will shed more light on these processes.

MESSENGER's suite of instruments also has provided insight into the mineral makeup of the surface terrain and detected ultraviolet emissions from sodium, calcium and hydrogen in Mercury's exosphere. The spacecraft explored the sodium-rich exospheric "tail," which extends more than 25,000 miles from the planet.

"We should keep this treasure trove of data in perspective. With two flybys to come and an intensive orbital mission to follow, we are just getting started to go where no one has been before," said project scientist Ralph McNutt of the Applied Physics Laboratory, Laurel, Md.

Adapted from materials provided by National Aeronautics and Space Administration.

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Nova Finding Challenges Thinking On Powerful Stellar Explosions

Daily Science Journal (Feb. 2, 2008) — First results from a new NASA-funded scientific instrument at the W. M. Keck Observatory in Hawaii are helping scientists overturn long-standing assumptions about powerful explosions called novae and have produced the first unified model for a nearby nova called RS Ophiuchi.

This artist rendering depicts the RS Ophiuchi binary system shortly after the white dwarf (right) has exploded as a nova. The other star is a red giant. Note the spiral dust lanes. (Credit: Casey Reed; Courtesy of NASA/Goddard Space Flight Center)

"We were getting ready for a routine engineering run when all of a sudden the nova went off. It was very bright and easy to observe, so we took this opportunity and turned it into gold," says team member Marc Kuchner of NASA's Goddard Space Flight Center in Greenbelt, Md.

Kuchner and his colleagues used the "nulling" mode of the Keck Interferometer, which is part of the NASA-funded Keck Interferometer. This state-of-the-art instrument combines starlight using two 10-meter (33 feet) telescopes. In the nulling mode, the interferometer suppresses the blinding light of a star so researchers can study the surrounding environment. The instrument helps researchers observe very faint objects near bright sources and produces ten times more resolving power than a single Keck telescope working alone. It is the only instrument of its kind in operation.

The Keck Nuller was undergoing tests on February 12, 2006, when a nova flared up in the constellation Ophiuchus. The system, known as RS Ophiuchi, consists of a white dwarf and a red giant. The red giant is gradually shedding its massive gaseous outer layers, and the white dwarf is sweeping up much of this wind, growing in mass over time. As the matter builds up on the white dwarf's surface it eventually reaches a critical temperature that ignites a thermonuclear explosion that causes the system to brighten 600-fold. RS Ophiuchi was previously seen to blow its stack in 1898, 1933, 1958, 1967, and 1985, so astronomers were eagerly anticipating the 2006 eruption.

Just 3.8 days after the nova was detected, the group observed the explosion with the Keck Nuller. The team set the instrument to cancel out the nova's light, allowing the group to see the much fainter surrounding material. The group next adjusted the nuller to observe the extremely bright blast zone.

The instrument's versatility was key to a surprising discovery. The nuller saw no dust in the bright zone, presumably because the nova's blast wave vaporized dust particles. But farther from the white dwarf, at distances starting around 20 times the Earth-Sun distance, the nuller recorded the spectral signature of silicate dust. The blast wave had not yet reached this zone, so the dust must have pre-dated the explosion.

"This flies in the face of what we expected. Astronomers had previously thought that nova explosions actually create dust," says Richard Barry of NASA Goddard, lead author of a paper on the Keck observations that will be published in the Astrophysical Journal.

The team thinks the dust is created as the white dwarf plows through the red giant's wind, creating a pinwheel pattern of higher-density regions that is reminiscent of galaxy spiral arms. Inside these spiral arms, atoms reach low enough temperatures and high enough densities to allow atoms to stick together to form dust particles. The nova's blast wave has since destroyed RS Ophiuchi's pinwheel pattern, but it should re-form over the next few years, and future Spitzer Space Telescope observations could see it.

Most studies of RS Ophiuchi have relied on spectroscopic models, but those methods have not been able to distinguish various nova components with as much detail as the interferometer. The Keck Nuller measured one component of the RS Ophiuchi system to an accuracy of just 4 milliarcseconds, or about the size of a basketball seen 7,500 miles away.

Barry is also coauthor of a paper based on Spitzer observations of RS Ophiuchi. This paper reports independent evidence for silicate dust that predates the 2006 explosion.

"The RS Ophiuchi observations are just a small taste of the power and potential we expect from the Keck Nuller," says coauthor William Danchi of NASA Goddard. "But ultimately we want to launch a nulling interferometer into space to image extrasolar planets. These Keck results are a technological and scientific pathfinder toward that future."

Adapted from materials provided by NASA/Goddard Space Flight Center.

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Building Safety Into Robots, Cars, Planes And Medical Equipment

Daily Science Journal (Feb. 2, 2008) — A revolutionary new technology developed by engineers at the University of Leicester after over 12 years research promises to make safety a sure thing in equipment as diverse as cars, aircraft and medical equipment.

TE Systems: Left to right: Devaraj Ayavoo, John Gordon, Anjali Das at the driving simulator and Michael Pont. (Credit: Image courtesy of University of Leicester)

The new patented technology invented by the researchers has led to the development of a new product family called "RapidiTTy". A company -- TTE Systems Ltd - has been spun out from the University of Leicester to develop and market this product.

TTE Systems Ltd aims to transform the way engineers develop systems which contain "embedded processors". Aircraft, cars, medical equipment and industrial robots are all examples of modern systems which contain such processors. Many of these embedded systems are safety related.

The company believes its new technology can make all the difference between life and death in some scenarios.

Dr. Devaraj Ayavoo, Technical Manager, TTE Systems Ltd, said: "If you are surfing the Web and it takes a few seconds longer than normal to access a particular page, this won't usually matter at all. However, if you put your foot on the brakes in your car, you can't afford to wait -- you need to be sure that the brakes will work immediately. At TTE Systems, our job is to ensure that complex embedded systems always work correctly."

Dr. Michael Pont, CEO of TTE Systems Ltd and Head of the Embedded Systems Laboratory at the University of Leicester, added: "Clearly there are many systems currently in use that are perfectly safe.

"However what is not easy at present is making systems safe and proving that they are safe. Our technology makes it easier to develop systems with predictable behaviour - a key requirement for safe systems.

"In an industry that is geared at developing new systems very quickly, the development of predicable systems has often been ignored and it is in this area that we have specialised.

"Our work involves what are known as "time triggered" -- or TT - designs. The goal with this technology can be stated very simply: In a TT design, we know in advance exactly what the embedded system will be doing at every moment of time during its execution.

"This is a highly innovative approach to system development.

"Our techniques can be applied in a very wide range of systems - even where safety is not a key requirement. For example, in many consumer appliances -- like washing machines, dishwashers, even DVD players -- customers would welcome improved reliability."

TTE Systems Ltd, created with support from the Lachesis Fund (the University Challenge Fund for the East Midlands), has launched the first products in the RapidiTTy family. The RapidiTTy family provides a complete, cost-effective, suite of software tools which support the rapid development and testing of a wide range of reliable embedded systems. The RapidiTTy tools build on a solid technical foundation ("time-triggered architectures"). These were developed in the Embedded Systems Laboratory at the University of Leicester over a period of more than 12 years. Staff in the Laboratory have an international reputation for their work in this area. To date, seven patent applications have been filed in connection with this new technology.

Dr Pont said there was real potential for the systems developed at Leicester to make an international impact: "Our tools make it very easy to incorporate our technology in "standard" development processes.

"Using time-triggered technology allows us to create low-cost tools which facilitate the rapid development of reliable embedded systems. Our goal is to make reliability a cornerstone of mainstream development tools."

Dr. Ayavoo added: "The design of embedded systems is often an extremely complicated process. Our users have been amazed how easy RapidiTTy is to use."

The ESDL is a newly-created lab which is funded by EMDA and hosted by the University of Leicester in New Walk, Leicester.

Adapted from materials provided by University of Leicester.

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Kidney Cancer Drug Attacks A Major Type Of Acute Myeloid Leukemia

Daily Science Journal (Feb. 1, 2008) — A drug used to treat kidney cancer also targets a genetic mutation active in about one third of patients with acute myeloid leukemia (AML), the most common and lethal form of adult leukemia, researchers at The University of Texas M. D. Anderson Cancer Center report in the Jan. 29 edition of the Journal of the National Cancer Institute.

In a Phase I clinical trial, the drug sorafenib reduced the median percentage of leukemia cells circulating in the blood from 81 percent to 7.5 percent and in the bone marrow from 75.5 percent to 34 percent among AML patients whose leukemia includes the FLT3-ITD mutation. Two patients had circulating leukemia cells, or blasts, drop to zero.

"AML patients with this mutation have a particularly poor prognosis, so this highly targeted drug appears to be a significant step forward in leukemia therapy," says senior author Michael Andreeff, M.D., Ph.D., professor in M. D. Anderson's Department of Stem Cell Transplantation and Cellular Therapy and Department of Leukemia.

The JNCI paper reports the drug's effect in lab experiments, a mouse model of the disease, and in a Phase I study of 16 patients with relapsed or resistant AML known to have the FLT3-ITD mutation.

There have been no major side effects in the clinical trial to date, so no maximum tolerated dose has been reached, Andreeff notes. The drug has little effect on cells with normal versions of the gene and does not interfere with normal blood cell formation.

A Phase I/Phase II clinical trial for AML is open at M. D. Anderson that combines sorafenib with the standard of care chemotherapy combination for AML, idarubicin and cytosine arabinoside. Presently, the trial is open for relapsed patients and those newly diagnosed with high-risk disease, says study co-author Jorge Cortes, M.D., professor in M. D. Anderson's Department of Leukemia. As safety and dose escalation research progress, sorafenib will be made available to other patients and assume a role in frontline therapy.

About 14,000 new cases of AML are diagnosed annually in the United States and the disease kills about 9,000 people each year. AML is characterized by swift proliferation of immature white blood cells in the blood and bone marrow that crowds out normal cells, leaving patients exposed to infection, severe anemia, and bleeding.

While major progress has been made treating some forms of leukemia and lymphoma, acute myeloid leukemia has seen less improvement in recent years. Andreeff says that's because AML exploits multiple molecular pathways and that these pathways differ from one type of AML to the next.

Andreeff and colleagues have shown that molecular pathways subverted and used by AML collude with each other, so when one pathway is blocked, the others redouble their efforts to fuel the disease.

"Here we have a great response against an important mutation, but sorafenib alone will not cure patients," Andreeff notes. Combination therapy will be required. Andreeff and colleagues are planning to examine other sorafenib combinations against FLT3-mutant disease.

After in vitro tests showed that sorafenib inhibited the growth of FLT3 mutant leukemia cell colonies, the research team tested the medication in a mouse model of the disease. Sorafenib-treated mice had a median survival of 36.5 days compared with 20.5 days in untreated mice. Bioluminescence imaging showed widespread cancer growth in untreated mice and barely detectable disease in those that had received the drug.

Sorafenib, known commercially as Nexavar® and co-developed by Bayer AG and Onyx Pharmaceuticals, already is approved for advanced renal cell carcinoma and inoperable liver cancer by the U.S. Food and Drug Administration. It is being tested against other solid tumors.

The drug targets both tumor cell growth and angiogenesis - new blood vessels woven by cancer to sustain itself - by targeting two classes of kinases, which are enzymes that affect proteins by attaching phosphate groups to them.

Sorafenib's antileukemia effects appear to be superior to early results of new therapies under development that more narrowly target the FLT3 gene. Andreeff says the drug's ability to hit multiple kinases probably accounts for this, but the exact molecular mechanisms involved require further study.

Co-authors with Andreeff and Cortes are lead author Weiguo Zhang, M.D., Ph.D., who conducted most of the project's laboratory research, Marina Konopleva, M.D., Ph.D., Yue-xi Shi, Teresa McQueen, Xiaoyang Ling, Ph.D., all of the department of Stem Cell Transplantation and Cellular Therapy; David Harris, Zeev Estrov, M.D., and Alfonso Quintas-Cardama, M.D. all of the Department of Leukemia; and David Small, M.D. of Johns Hopkins University School of Medicine.

Research was funded by grants from the National Cancer Institute, a Leukemia SPORE Career Development Award, and the Cancer Therapy Evaluation Program.

Adapted from materials provided by University of Texas M. D. Anderson Cancer Center.

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Diabetes Makes It Hard For Blood Vessels To Relax

Daily Science Journal (Feb. 1, 2008) — One way diabetes is bad for your blood vessels is by creating too much competition for an amino acid that helps blood vessels relax, researchers say.

One way diabetes is bad for your blood vessels is by creating too much competition for an amino acid that helps blood vessels relax, researchers say. (Credit: Image courtesy of Medical College of Georgia)

That amino acid, L-arginine, is broken down by the enzyme arginase to urea, which helps the body eliminate toxins resulting from the proteins we eat. Diabetics have a lot of arginase activity, which means they use a lot more L-arginine, says Dr. Maritza Romero, postdoctoral fellow at the Medical College of Georgia and lead author of the paper published in the current issue of Circulation Research.

It also means too little L-arginine is available to help nitric oxide synthase make nitric oxide, the powerful vasodilator that helps blood vessels relax, says Dr. Romero, who works in the lab of Dr. R. William Caldwell, chair of the MCG Department of Pharmacology and Toxicology and the study's corresponding author.

Researchers also found the amino acid, L-citrulline, as well as statins, compounds known to lower cholesterol, prevent elevation of arginase activity, restoring normal dilation abilities in animal models of type 1 diabetes. In fact, L-citrulline can be recycled into L-arginine.

Now they want to know specific factors and pathways involved in arginase activation and develop pharmaceutical agents to combat excessive arginase activity in diabetes. They also suggest clinical trials of L-citrulline as a supplemental therapy for diabetics with vascular problems.

Their findings also help explain why L-arginine supplement, marketed to treat hypertension, chest pain, heart failure and more, may not work long term. In the January 4, 2006 issue of the Journal of the American Medical Association, Johns Hopkins researchers reported that a clinical trial of patients taking an L-arginine supplement following a heart attack didn't improve in their vascular tone or their hearts' ability to pump. In fact, more patients died who were taking L-arginine than placebo and the study was closed with the recommendation the supplement not be used by heart attack patients. The supplement still is widely marketed.

"The findings of increased arginase I activity in diabetes may limit other therapeutic approaches proposed for early endothelial dysfunction such as oral L-arginine supplementation," Drs. Thomas L. Luscher and Jan Steffel, of the University of Zurich Cardiovascular Research Institute write in an accompanying editorial. "Although dietary L-arginine supplementation has been shown to exert vascular protective effects in certain clinical settings, this approach is unlikely to be effective in diabetes, if the results of this study can be confirmed by patients in vivo. In fact, the findings of Romera et al may provide a possible explanation for the unexpected neutral or even adverse effects of oral L-arginine in some clinical studies, in particular patients with coronary artery disease and infarction."

A short intravenous course of L-arginine may provide short-term improvement in blood vessel tone, Dr. Romero notes. However most of L-arginine ingested goes directly to the liver to be broken down, not the bloodstream where it can promote relaxation of blood vessels, Dr. Romero says.

Arginase also is associated with vascular problems related to aging, hypertension, sickle cell disease, atherosclerosis and erectile dysfunction, Dr. Romero says. L-citrulline already is taken by some sickle cell patients to reduce breath-taking fibrosis in their lungs. In addition to helping the body turn toxins into urea that can be safely eliminated from the body, arginase also helps in collagen formation and cell proliferation, but too much can be bad. In fact, Drs. Caldwell and Romero are pursuing studies of how increased arginase activity may harden blood vessel walls.

Adapted from materials provided by Medical College of Georgia.

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Medicine From Milk: Gene Therapy Transforms Goats Into Pharmaceutical Factories

Daily Science Journal (Feb. 1, 2008) — University of Pennsylvania researchers have used gene therapy to reduce the time it takes to breed large animals capable of producing therapeutic proteins in their milk, such as insulin or those that fight cancer. This represents a significant milestone in drug development, as current methods involve cloning, which takes more time and generally costs more.

Researchers have used gene therapy to reduce the time it takes to breed goats capable of producing therapeutic proteins in their milk, such as insulin or those that fight cancer. (Credit: iStockphoto)

"Having an easier way to harness nature's power to produce large quantities of specific proteins in milk could increase the availability of drugs for people who could otherwise not afford these treatments," said Ina Dobrinski, one of the researchers on the study.

The study also is significant because it may also be a new way to eliminate diseases in future generations of animals, such as those used for livestock. Here's why: To get the goats to produce specific proteins, the researchers used radiation to kill a portion of a male goat's germ cells (the cells that produce sperm). Then they used a modified adeno-associated virus (a well studied and tolerated gene therapy vector) to insert a gene in the remaining cells. Once the new gene took hold in the germ cells, a predictable number of female offspring produced the desired protein in their milk.

The advance is immediately valuable for pharmaceutical development and biology research, but a similar approach could be used to bolster the food supply by eliminating genetic disorders in animals over several generations. It is also possible that once perfected, this technique could eliminate disease genes in humans over several generations, assuming ethical concerns can be resolved adequately.

This study is published in the February 2008 print edition of The FASEB Journal.

"For thousands of years, people have domesticated cows and goats to make milk, butter and cheese. And for thousands of years dairy products have been used as folk remedies for practically every human illness. Most have been completely ineffective." said Gerald Weissmann, MD, editor-in-chief of The FASEB Journal. "So it is reassuring that modern science would find a way to use the milk we drink to yield of drugs that actually work."

Adapted from materials provided by Federation of American Societies for Experimental Biology, via EurekAlert!, a service of AAAS.

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Why Scratching Relieves An Itch

Daily Science Journal (Feb. 1, 2008) — In the first study to use imaging technology to see what goes on in the brain when we scratch, researchers at Wake Forest University Baptist Medical Center have uncovered new clues about why scratching may be so relieving -- and why it can be hard to stop.

"Our study shows for the first time how scratching may relieve itch," said lead author Gil Yosipovitch, M.D., a dermatologist who specializes in itch. "It's important to understand the mechanism of relief so we can develop more effective treatments. For some people, itch is a chronic condition that affects overall health."

The study involved 13 healthy participants who underwent testing with functional magnetic resonance imaging (MRI) technology that highlights areas of the brain activated during an activity. Participants were scratched on the lower leg with a small brush. The scratching went on for 30 seconds and was then stopped for 30 seconds -- for a total of about five minutes.

"To our surprise, we found that areas of the brain associated with unpleasant or aversive emotions and memories became significantly less active during the scratching," said Yosipovitch. "We know scratching is pleasurable, but we haven't known why. It's possible that scratching may suppress the emotional components of itch and bring about its relief."

The reduced brain activity occurred in the anterior cingulate cortex, an area associated with aversion to unpleasant sensory experiences, and the posterior cingulate cortex, which is associated with memory. When participants reported that the scratching felt most intense, activation in these areas was lowest.

Yosipovitch said patients occasionally report that intense scratching -- to the point of drawing blood -- is the only thing that relieves chronic itch.

"This is the first real scientific evidence showing that itch may be inhibited by scratching," he said. "Of course, scratching is not recommended because it can damage the skin. But understanding how the process works could lead to new treatments. For example, drugs that deactivate this part of the brain might be effective."

The imaging studies also showed that some areas of the brain were made more active by the scratching, including the secondary somatosensory cortex, a sensory area involved in pain, and the prefrontal cortex, which is associated with compulsive behavior.

"This could explain the compulsion to continue scratching," said Yosipovitch.

One drawback to the study is that the scratching occurred in the absence of itch. Yosipovitch's team is continuing the research by evaluating whether the findings will apply to chronic itch.

Understanding more about chronic itch is important, Yosipovitch said, noting that more than 30 million Americans suffer from eczema and that almost half (42 percent) of kidney dialysis patients are bothered by moderate to severe itch. In fact, those kidney dialysis patients with itch have a 17 percent higher mortality rate, likely from a loss of sleep, according to a report in Nephrology Dialysis Transplantation.

The work is reported online in the Journal of Investigative Dermatology and will appear in a future print issue.

The study was supported by the National Institutes of Health and the Center for Biomolecular Imaging of Wake Forest. Co-researchers were Yozo Ishuiji,MD, Tajesh Patel, M.D., Maria Isabel Hicks, M.D., Yoshitetsu Oshiro, M.D., Robert Kraft, Ph.D., Erica Winnicki, M.D., and Robert C. Coghill, Ph.D., senior author, all from Wake Forest.

Adapted from materials provided by Wake Forest University Baptist Medical Center, via EurekAlert!, a service of AAAS.

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How Poxviruses Such As Smallpox Evade The Immune System

Daily Science Journal (Feb. 1, 2008) — Scientists at Saint Louis University and the University of Alabama at Birmingham have uncovered important new information about a key protein that allows viruses such as smallpox to replicate and wreak havoc on the immune system.

The findings further our understanding of how the pox family of viruses work to subvert the immune system, the researchers say. They also believe their work could one day be used to develop new drugs to combat a variety of inflammatory and immunological disorders, including rheumatoid arthritis and some forms of heart disease.

The paper* describes the structure and actions of a powerful substance called interferon-gamma binding protein, which is notorious for the role it plays in helping the poxviruses to replicate. The research explores the interferon-gamma binding protein found in the mousepox virus -- one of the family of viruses that also includes smallpox, monkeypox and cowpox.

"Cracking open and describing the structure and actions of interferon-gamma binding protein is incredibly exciting, given the important role this substance plays in subverting the immune system," said Mark Buller, Ph.D., professor of microbiology and immunology at the Saint Louis University School of Medicine and one of the study's authors. "This breakthrough is something that many others have tried and failed to achieve."

Normally when a virus enters the bloodstream, the immune system responds by producing a substance called interferon-gamma, which assists the development of the immune response that's responsible for ridding the body of the virus.

Poxviruses, however, all come encoded with a potent weapon to evade the immune system: interferon-gamma binding protein. As its name implies, the protein literally binds to interferon-gamma and immobilizes it, preventing it from marshalling the immune system's defenses. The poxvirus is then able to replicate and cause immense damage.

The research describes how interferon-gamma binding protein looks and behaves on the molecular level during this process, something not previously understood.

"The poxviruses are able to evade the immune system very skillfully," Buller said, "so we wanted to identify exactly how these viruses work -- what makes them so effective and efficient."

Buller added that the findings have great potential for use in developing drugs that target immunological and inflammatory disorders, including a type of heart disease called atherosclerosis (sometimes referred to as hardening of the arteries), inflammatory bowel diseases (such as Crohn's disease and ulcerative colitis) and rheumatoid arthritis.

Of all the poxviruses, smallpox in particular has played a gruesome role in human history. The virus is estimated to have caused between 300 million and 500 million deaths in the 20th century alone. Though smallpox was declared officially eradicated in 1979, many experts fear that clandestine samples of the virus may have survived -- thus making it a major bioterrorism concern.

"The damage that the smallpox virus has done to mankind is horrific and enormous, which is why we think it's so important to understand more about the poxviruses and how they operate," Buller said. "The more knowledge we have, the better we should be able to cope with other major viruses and diseases in the future."

Buller pointed to co-author Tony Nuara as being critical to the team's success in understanding more about interferon-gamma binding protein. Nuara, now a fourth-year student at Saint Louis University School of Medicine, was working on his Ph.D. in molecular microbiology when taking part in the research effort.

"Without Tony, this research wouldn't have happened," Buller said. "He solved huge numbers of problems and figured out some answers to puzzling questions that previously had no answer."

Mark R. Walter, Ph.D., associate professor of microbiology at the University of Alabama at Birmingham and the paper's senior author, also noted the efforts of co-authors Sung Il Yoon, Ph.D., Brandi C. Jones, Naomi J. Logsdon and Leigh J. Walter, all of whose work contributed to determining the three-dimensional structure of the binding protein.

"The structure provides a visual blueprint to guide our future studies on interferon-gamma binding protein, which one day may be used to prevent inflammatory disease," Mark Walter said. "This is clearly a notable achievement."

*The research has been published in an early online edition of the Proceedings of the National Academy of Sciences. Jill M. Schriewer of Saint Louis University was also a co-author of the study.

The research was funded by grants from the National Institutes of Health, the UAB Center for Emerging Infections and Emergency Preparedness, and the American Heart Association.

Adapted from materials provided by Saint Louis University, via EurekAlert!, a service of AAAS.

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Sugary Soft Drinks Linked To Increased Risk Of Gout In Men

Daily Science Journal (Feb. 1, 2008) — Consumption of sugar sweetened soft drinks and fructose is strongly associated with an increased risk of gout in men, finds a study published by the British Medical Journal.

Gout is a joint disease which causes extreme pain and swelling. It is most common in men aged 40 and older. It is caused by excess uric acid in the blood (hyperuricaemia) which leads to uric acid crystals collecting around the joints.

In the United States, levels of gout have doubled over the last few decades, which coincided with a substantial increase in the consumption of soft drinks and fructose (a simple sugar and the only carbohydrate known to increase uric acid levels).

Conventional dietary recommendations for gout have focused on the restriction of purines (found in high levels in meat and meat products, especially liver and kidney) and alcohol but with no restriction of sugar sweetened soft drinks.

So researchers in the US and Canada examined the relation between intake of sugar sweetened soft drinks and fructose and the risk of gout.

They followed over 46,000 men aged 40 years and over with no history of gout. The men completed regular questionnaires on their intake of more than 130 foods and beverages, including sugar sweetened soft drinks and diet soft drinks, over a period of 12 years. Different types of fruits and fruit juices (high in natural fructose) were also assessed.

At the start of the study, and every two years thereafter, information on weight, regular use of medications and medical conditions were also recorded. Gout was diagnosed according to American College of Rheumatology criteria.

During 12 years of follow-up, the researchers documented 755 newly diagnosed cases of gout.

The risk of gout increased with increasing intake of sugar sweetened soft drinks. The risk was significantly increased with an intake level of 5-6 servings per week and the risk was 85% higher among men who consumed two or more servings of sugar-sweetened soft drinks per day compared to those who consumed less than one serving per month.

These associations were independent of other risk factors for gout such as body mass index, age, diuretic use, high blood pressure, alcohol intake, and dietary factors.

Diet soft drinks were not associated with the risk of gout.

Fruit juice and fructose rich fruits (apples and oranges) were associated with a higher risk of gout. However, the authors stress that this finding needs to be balanced against the benefit of fruit and vegetable intake to prevent other chronic disorders like high blood pressure, coronary heart disease, stroke and certain types of cancer.

In conclusion, our findings provide prospective evidence that consumption of sugar sweetened soft drinks and fructose is strongly associated with an increased risk of gout, say the authors. Furthermore, fructose rich fruits and fruit juices may also increase the risk. In contrast, diet soft drinks were not associated with the risk of gout.

Adapted from materials provided by BMJ-British Medical Journal, via EurekAlert!, a service of AAAS.

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New Gene Linked To Fragile X Syndrome -- Suggests Potential Targets For Autism And Other Neurological Disorders

Daily Science Journal (Feb. 1, 2008) — Scientists at The Scripps Research Institute have discovered a new gene involved in fragile X syndrome, a condition that often shares many symptoms of autism. The discovery may lead to new tests or treatments for several neurological disorders.

The new gene has been dubbed FMR4. "FMR4 is a novel gene that is located in the same chromosomal neighborhood as FMR1, a well established causative gene in fragile X syndrome," said Claes Wahlestedt, a professor at the Scripps Research campus in Jupiter, Florida. "Like FMR1, FMR4 is silenced in fragile X patients and up-regulated in FXTAS (fragile X-associated tremor/ataxia syndrome), a disease that resembles Parkinson's disease. Our discovery could lead to the development of new diagnostic tests or even to novel therapies for these defects."

Fragile X syndrome affects thousands of patients worldwide with severe learning disabilities, often accompanied by anxiety disorders, obsessive-compulsive behavior, and attention deficit hyperactivity disorder. There are currently no therapeutic treatments available for fragile X syndrome. Approximately one-third of all children diagnosed with fragile X syndrome also have some degree of autism, according to The National Fragile X Foundation, including such behaviors as social anxiety, poor eye contact, and hand biting.

More than 16 years ago, scientists linked fragile X syndrome to inactivation of FMR1 gene expression, leading to the lack of a protein known as the fragile X mental retardation protein, now considered to be critical for neuronal function. Until the current study, no other functional gene other than FMR1 had been shown to be inactivated in the disorder.

However, Wahlestedt knew the FMR1 gene locus-a specific point on a chromosome-was not well mapped. Wahlestedt and his colleagues hypothesized that unknown regulatory genes might be transcribed from the region.

The new study shows at least one other functional gene-FMR4-from this genetic region is linked to fragile X syndrome, although the gene's exact role in the intact brain remains uncharacterized..

"FMR4 is the new neighbor on the block and should not be ignored," Wahlestedt said. "While there is no direct relationship between these two genes [FMR1 and FMR4] that we know of, our study shows that FMR4 is not a conventional gene-it's a non-coding RNA transcript. It's not a dead piece of the genome, it has a pronounced functional effect in human cultured cells.."

The Role of Non-coding RNA

Non-coding RNA (ncRNA) transcripts or genes produce functional RNA molecules (ncRNAs) rather than encoding proteins. These ncRNAs are active in a number of different processes, including RNA modification, chromosome replication, and protein degradation.

A number of studies have suggested that at least 40 to 50 percent of the mammalian genome becomes transcribed, Wahlestedt pointed out, but only one to two percent of these transcripts are translated into proteins. "Several studies suggest that some ncRNA genes can be involved in various human diseases," he said. "FMR4 certainly falls into that category."

According to the study, FMR4 directly affects human cell proliferation in vitro-when the gene is silenced, changes in the cell cycle and a rise in apoptosis or programmed cell death occur. Overexpression, on the other hand, leads to increased cell proliferation.

The full meaning of this anti-apoptosis function is still unclear. "It could be critical for some cells to live or die at a certain stage in development, but we don't know what cells those might be," Wahlestedt added. "The fact that FMR4 is widely expressed in the human brain in both embryos and adults may possibly indicate a broad function."

The new study underscores the growing awareness among scientists of the complexity and unpredictability of the human genome.

"We know now that our genome is very busy and very complicated," Wahlestedt said "A great deal of this newly found complexity is about the regulation of other genes. As evolution has progressed, particularly in the higher organisms, there has been a corresponding increase in the need for regulatory mechanisms-to maintain more control over genome. Non-coding RNAs are at the center of these regulatory mechanisms."

The FMR4 discovery also highlights the mission of The Translational Research Institute at Scripps Florida, which is focused on translating basic research like the discovery of FMR4 into potential new therapeutics. The Translational Research Institute has a structure similar to a drug discovery company, and many of the researchers have pharmaceutical experience.

In addition to Wahlestedt, other authors of the study include Ahmad M. Khalil, Mohammad Ali Faghihi, Farzaneh Modarresi, and Shaun P. Brothers of The Scripps Research Institute in Jupiter, Florida.

The study, A Novel RNA Transcript with Antiapoptotic Function is Silenced in Fragile X Syndrome, was supported by Conquer Fragile X Foundation (now part of National Fragile X Foundation) and The Scripps Research Institute Florida. Upon publication, the study will be available at http://www.plosone.org/doi/pone.0001486.

Adapted from materials provided by Scripps Research Institute.

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Pathway To Turn Off Immune System Cells Discovered

Daily Science Journal (Feb. 1, 2008) — University of Minnesota researchers have discovered a new way to turn genes off in human T cells, a type of white blood cell that helps the immune system fight infections.

Turning off genes, through a process known as mRNA decay, is important for regulating the body's immune response after fighting infection. This research could lead to development of new drugs that turn off the immune system in patients with autoimmune diseases -- such as rheumatoid arthritis and lupus. It could also prevent cancer cells from dividing.

Researchers used a novel approach that combines molecular biology and computational analysis to identify mRNA sequence responsible for turning off T cells.

"Although this study analyzed T cells, this pathway is present in all human cells," said Paul Bohjanen, M.D., Ph.D., co-director of the Center for Infectious Diseases and Microbiology Translational Research (CIDMTR) and principal investigator of the study. "Knowledge from this study can be applied to help researchers better understand other types of cells and how they function."

During an infection, T cells turn on and divide to help clear the infection from the body. After the infection is cleared, the cells need to turn off so the body can return to a stable condition. If the cells do not turn off, however, they can cause damage to the body and can potentially develop into cancer cells.

This research is important because to date, understanding the mechanisms that turn off cells has not been very well understood.

Researchers measured the rate of mRNA decay for each of the approximately 6,000 genes in human T cells. That information was then analyzed by George Karypis, Ph.D., associate professor of computer science, and his colleagues at the Minnesota Supercomputing Institute, using complex computer programs to identify a sequence present in mRNA that was destroyed rapidly in the cell. Bohjanen and his colleagues performed molecular biology experiments to confirm that this sequence targets mRNA for destruction and was responsible for turning off genes in activated T cells.

"This discovery would not have been possible without the interdisciplinary collaboration between molecular biologists and computer scientists," Bohjanen said. The collaboration between Bohjanen and Karypis was facilitated by Irina Vlasova, M.D., Ph.D., research associate in Bohjanen's molecular biology laboratory, who received training in computational biology through a Minnesota Supercomputing Institute fellowship.

The research is published in the February 1 issue of Molecular Cell. The research was conducted by researchers at CIDMTR, Department of Microbiology, Department of Medicine, Department of Computer Science, and Division of Biostatistics.

The research was funded by grants from the National Institutes of Health, the Minnesota Medical Foundation, the Minnesota Supercomputing Institute, the Lymphoma Research Foundation, and the Swedish Research Council.

Adapted from materials provided by University of Minnesota, via EurekAlert!, a service of AAAS.

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Malaria Vaccine Trials Begin Using 'Chimpanzee Virus'

Daily Science Journal (Feb. 1, 2008) — Trials are underway for a new vaccine to combat the most deadly form of malaria. For the first time ever, researchers will use a virus found in chimpanzees to boost the efficacy of the vaccine.

Malaria, caused by Plasmodium parasites, is one of the world's deadliest killers, killing over a million people each year, mainly women and young children in Africa and SE Asia. The most deadly species , P. falciparum, is responsible for 80% of malaria infections and 90% of deaths. As yet, there is no vaccine against malaria. This is because, for much of their life-cycle, the parasites responsible for infection live inside cells, where they cannot be reached by antibodies.

The trials will take place at the University of Oxford's Jenner Institute, led by its Director, Professor Adrian Hill.

"We urgently need a vaccine to help in the fight against this deadly killer," says Professor Hill, a Wellcome Trust* Principal Research Fellow. "Malaria parasites are able to outwit our immune system by hiding out in the body's cells, however. Finding a way to generate enough immune cells and antibodies to identify and destroy the parasites will be the key to preventing infection."

The vaccine being developed and trialled by Professor Hill's team in collaboration with Okairòs uses the company's genetically-modified chimpanzee adenovirus to produce the malaria antigen and to stimulate a response to the vaccine in the body. Adenoviruses appear to be particularly potent for increasing the immune response to the malaria vaccine. However, because human adenoviruses, which cause diseases including the common cold and gastroenteritis, are widespread, most people have developed some immunity towards them. Using a chimpanzee adenovirus ensures that a recipient is unlikely to have resistance to this component of the vaccine.

"Chimpanzees have their own set of adenoviruses which rarely infect humans, so we have not built up immunity to them," explains virologist Dr Sarah Gilbert at the Jenner Institute. "This is why we have chosen such a virus to form the backbone of the new vaccine."

Professor Hill's team is currently recruiting for more volunteers for the first trials, which are to assess the safety of the vaccine. Because the active component of the adenovirus is removed, however, there is no danger of transmission to the human of the original chimpanzee virus.

The trial will also be measuring the response of the immune system. The team hopes to generate a response from CD8+ T-cells (sometimes known as killer cells) that should kill the parasites when they enter the liver, where they multiply undetected. However, if the T-cells do not kill all of the parasites, any that escape from liver into the bloodstream will still be able to enter red blood cells and cause illness.

The group plans to test a second vaccine which would then target the parasites in the bloodstream and red blood cells.

"Our ultimate goal is a combination product which targets the parasite at both the liver stage and the blood stage," says Professor Hill. "Few people still think that you can get really strong protection from malaria based on a single component."

Over a dozen vaccines have now been made by scientists at the University of Oxford and taken into clinical trials, but this is the first vaccine to have also been manufactured within a UK university, according to Professor Hill.

*Funding was provided by the Wellcome Trust.

Adapted from materials provided by