As the swine flu continues its global spread, researchers from the Children’s Hospital of Philadelphia, Pennsylvania, have discovered important clues about why influenza is more severe in some people than it is in others. In their research study published online in the Journal of Leukocyte Biology (http://www.jleukbio.org), the scientists show that the influenza virus can actually paralyze the immune systems of otherwise healthy individuals, leading to severe secondary bacterial infections, such as pneumonia. Furthermore, this immunological paralysis can be long-lived, which is important to know when developing treatment strategies to combat the virus.

According to Kathleen Sullivan, M.D., Ph.D., the senior researcher involved in the study and Chief of the Division of Allergy and Immunology at the Children’s Hospital of Philadelphia, “We have a very limited understanding of why some people who get influenza simply have a bad cold and other people become very sick and even die. The results of this study give us a much better sense of the mechanisms underlying bacterial infections arising on top of the viral infection.”

Sullivan and colleagues recruited pediatric patients with severe influenza and examined the level of cytokines, which serve as the first line initiators of immune response, in the blood plasma. Although they found elevated levels of cytokines, they also found a decreased response of toll-like receptors, which activate immune cell responses as a result of invading microbes. This suggests that the diminished response of these receptors may be responsible for the paralysis of the immune system, leading to secondary bacterial infections. The influenza patients were compared with patients with moderate influenza, respiratory syncytial virus, and a control group of healthy individuals. The immune paralysis appeared to be specifically a result of influenza infection and was not seen in patients with respiratory syncytial virus. This process might explain why one quarter of children who die from influenza, die from a bacterial infection occurring on top of the virus.

“Despite major medical advances since the devastating flu outbreak of 1918 and 1919, influenza virus infection remains a very serious threat,” said John Wherry, Ph.D., Deputy Editor of the Journal of Leukocyte Biology, “and the current swine flu outbreak is a grim reminder of this fact. The work by Dr. Sullivan and colleagues brings us a step closer to understanding exactly what goes wrong in some people who get the flu, so, ultimately, physicians can develop more effective treatment strategies.”

Source: Federation of American Societies for Experimental Biology

The idea that far distant particles can somehow ‘talk’ to each other worried Einstein so much that he called it ’spooky action at a distance’.

Having confirmed its existence, scientists today are learning how to use this ’spooky action’ as a helpful tool. Now a team of physicists at the University of Bristol and Imperial College London have harnessed this phenomenon to shed light on another unusual and previously difficult aspect of quantum physics – that of distinguishing between two similar quantum devices.

In the everyday world any process can be considered as a black box device with an input and an output; if you wish to identify the device you simply apply inputs, measure the outputs and determine what must have happened in between.

But quantum black boxes are different. Distinguishing between them is impossible using only single particle inputs because the outputs are not distinguishable: a fundamental consequence of the laws of quantum mechanics is that only very few states of a quantum particle can be reliably distinguished from one another.

The Bristol-Imperial team has shown how to get around this problem using ’spooky action’.

Anthony Laing, PhD student in the Department of Physics, who performed the study, said: “Apart from providing insight into the fundamentals of quantum physics, this work may be crucial for future quantum technologies.

“How else could a future quantum engineer build a quantum computer if they can’t tell which circuits they have?”

The new findings have implications for our understanding of quantum mechanics as well as the emerging potential of quantum information science.

Source: University of Bristol

Fire must be accounted for as an integral part of climate change, according to 22 authors of an article published in the April 24 issue of the journal Science. The authors determined that intentional deforestation fires alone contribute up to one-fifth of the human-caused increase in emissions of carbon dioxide, a heat-trapping gas that increases global temperature.

The work is the culmination of a meeting supported by the Kavli Institute for Theoretical Physics (KITP) and the National Center for Ecological Analysis and Synthesis (NCEAS), both based at the University of California, Santa Barbara and funded by the National Science Foundation (NSF).

The authors call on the Intergovernmental Panel on Climate Change (IPCC) to fully integrate fire into their assessments of global climate change, and consider fire-climate feedbacks, which have been largely absent in global models.

The article ties together various threads of knowledge about fire, which have, until now, remained isolated in disparate fields including ecology, global modeling, physics, anthropology and climatology.

Increasing numbers of wildfires are influencing climate as well, the authors report. “The tragic fires in Victoria, Australia, emphasize the ubiquity of recent large wildfires and potentially changing fire regimes that are concomitant with anthropogenic climate change,” said David Bowman of the University of Tasmania. “Our review is both timely and of great relevance globally.”

Carbon dioxide is the most important and well-studied greenhouse gas that is emitted by burning plants. However, methane, aerosol particulates in smoke, and the changing reflectance of a charred landscape each contribute to changes in the atmosphere caused by fire. Consequences of large fires have huge economic, environmental, and health costs, report the authors.

The authors state, “Earth is intrinsically a flammable planet due to its cover of carbon-rich vegetation, seasonally dry climates, atmospheric oxygen, widespread lightning and volcano ignitions. Yet, despite the human species’ long-held appreciation of this flammability, the global scope of fire has been revealed only recently by satellite observations available beginning in the 1980s.”

They note, however, that satellites cannot adequately capture fire activity in ecosystems with very long fire intervals, or those with highly variable fire activity.

Jennifer Balch, a member of the research team and a postdoctoral fellow at NCEAS, explains that there are bigger and more frequent fires from the western U.S. to the tropics. There are “fires where we don’t normally see fires,” she said, noting that it is in the humid tropics that a lot of deforestation fires are occurring, usually to expand agriculture or cattle ranching. “Wet rainforests have not historically experienced fires at the frequency that they are today. During extreme droughts, such as in 97-98, Amazon wildfires burned through 39,000 square kilometers of forest.”

Balch explains the importance of the article: “This synthesis is a prerequisite for adaptation to the apparent recent intensification of fire feedbacks, which have been exacerbated by climate change, rapid land cover transformation, and exotic species introductions–that collectively challenge the integrity of entire biomes.”

The authors acknowledge that their estimate of fire’s influence on climate is just a start, and they highlight major research gaps that must be addressed in order to understand the complete contribution of fire to the climate system.

Balch notes that a holistic fire science is necessary, and points out fire’s true importance. “We don’t think about fires correctly,” she said. “Fire is as elemental as air or water. We live on a fire planet. We are a fire species. Yet, the study of fire has been very fragmented. We know lots about the carbon cycle, the nitrogen cycle, but we know very little about the fire cycle, or how fire cycles through the biosphere.”

“The large and diverse group of authors on this paper typifies an increasing trend across many sciences,” said Henry Gholz, an NSF program director. “NSF explicitly supports this by funding “synthesis centers,” such as NCEAS and KITP. Instead of focusing on generating new data, these centers synthesize the results of literally thousands of completed research projects into new results, theories and insights. The conclusions of this paper–that fire is important to the global carbon cycle and global climate, and that our ignorance about fire at this scale is vast–and could not have otherwise been obtained.”

Source: National Science Foundation

In a step toward using gas hydrates as a future energy source, researchers in New York are reporting the first identification of an optimal temperature and pressure range for maximizing production of natural gas from the icy hydrate material. Their study appears in the March 18 issue of ACS’ Industrial & Engineering Chemistry Research, a bi-weekly journal.

Marco Castaldi, Yue Zhou, and Tuncel Yegualp note that gas hydrates, also known as “ice that burns,” are a frozen form of natural gas (methane). This material exists in vast deposits beneath the ocean floor and Arctic permafrost in the United States and other areas. Scientists believe that fuel from these frozen chunks, formed at cold temperatures and high pressures, may help fuel cars, heat homes, and power factories in the future. Although scientists have identified several different methods for extracting the fuel, including depressurization, researchers have not found an practical approach for producing the gas on an industrial scale.

To reach this goal, the researchers built what they believe to be the world’s largest experimental reactor, filled with sand, water, and methane, to simulate the formation gas hydrates (at low temperatures and high pressure) and production of the gas. While depressurizing the hydrates to free the methane, they observed an optimal boost in gas production between a narrow range of temperatures and pressures. Maintaining gas production at these settings could be a key step in boosting production of methane at an industrial scale, the researchers suggest. – MTS

“Experimental Investigation of Methane Gas Production from Methane Hydrate”

DOWNLOAD FULL TEXT ARTICLE:http://pubs.acs.org/stoken/presspac/presspac/full/10.1021/ie801004z

A new study identifies a protein that modifies the androgen receptor (AR) and influences its ability to regulate target genes linked with the progression of prostate cancer. The research, published by Cell Press in the April 7th issue of the journal Cancer Cell, may also drive creation of new strategies for the treatment of advanced prostate cancer that no longer responds to traditional anti-hormone therapies.

The AR is an important mediator for the development and progression of prostate cancer, including the progression to the aggressive and often lethal androgen-independent form of the disease. “Androgen ablation therapy is the most common treatment for advanced prostate cancer,” offers senior study author, Dr. Yun Qiu from the University of Maryland School of Medicine. “However, many patients inevitably develop deadly recurrent cancers, which no longer respond to androgen blockade and are resistant to current therapy.”

To better understand mechanisms associated with advanced prostate cancer, Dr. Qiu and colleagues performed a screen designed to search for proteins that interact with the AR in hormone-refractory prostate cancer cells. The researchers identified RNF6 as an AR associated protein and demonstrated that RNF6 induced ubiquitination of the AR and promoted AR transcriptional activity. Ubiquitination is a common protein modification that mediates a diverse range of cellular activities. One of the best known functions of ubiquitination is to promote protein degradation. However, ubiquitination of AR by RNF6 appeared to have a stabilizing effect on AR protein.

Importantly, inhibition of RNF6 or interference with ubiquitination of AR altered expression of a specific group of AR target genes and abrogated recruitment of AR and its required coactivators to androgen-responsive regulatory regions in these genes. The researchers went on to show that expression of RNF6 was increased in human prostate cancer tissues that do not respond to androgen ablation and is required for prostate tumor growth under androgen depleted conditions.

Taken together, the findings implicate RNF6 as an important regulator of AR transcriptional activity. “Our work suggests that ubiquitination of AR, and possibly other transcription factors, may function as the scaffold for cofactor recruitment to modulate transcriptional activity and specificity,” concludes Dr. Qiu. “Targeting components of the ubiquitination machinery, such as RNF6, may potentially be effective in treatment of advanced prostate cancer.”

Source: Cell Press

Fetal alcohol spectrum disorder (FASD) and Fetal alcohol syndrome (FAS) cause malformations in babies, including facial defects, short stature, and mental and behavioral abnormalities. The African frog, Xenopus, is a valuable tool for understanding early vertebrate development since these embryos are large, easy to work with and very responsive to environmental cues. New research uses this system to address the mechanism underlying the characteristics associated with maternal consumption of alcohol in early pregnancy.

Alcohol consumption prevents normal development by inhibiting the production of retinoic acid. Under normal conditions, the levels of retinoic acid made in different areas of the embryo provide cells with necessary information about their proper location and fate. Researchers now show that alcohol steals away the molecules that make retinoic acid and use them for its own process of detoxification, resulting in cellular disorientation during a critical period of development.

The new study, published in Disease Models & Mechanisms (DMM), dmm.biologists.org, provides evidence that the characteristics associated with FASD and FAS come from competition of alcohol for key molecules in a pathway that produce retinoic acid from vitamin A. Retinoic acid is needed for correct positioning of cells in developing embryos and by preventing its normal production, alcohol keeps cells from migrating to their correct positions and maturing properly. The researchers, at the Hebrew University in Israel, found that shutting down a molecule needed to produce retinoic acid, called retinaldehyde dehydrogenase or RALDH2, increased sensitivity of developing embryos to low doses of alcohol. Conversely, more of the molecule RALDH2 protected embryos from the negative effects of alcohol. This provides evidence that alcohol ‘hijacks’ RALDH2 molecules for its own breakdown process and steals it away from its important role in synthesizing positional and maturation cues during development.

Fetal alcohol spectrum disorder (FASD) and Fetal alcohol syndrome (FAS) cause malformations in babies, including facial defects, short stature, and mental and behavioral abnormalities. The African frog, Xenopus, is a valuable tool for understanding early vertebrate development since these embryos are large, easy to work with and very responsive to environmental cues. New research uses this system to address the mechanism underlying the characteristics associated with maternal consumption of alcohol in early pregnancy.

Source: The Company of Biologists

PHILADELPHIA – Three-day-old broccoli sprouts, a widely available human food, suppressed Helicobacter pylori (H. pylori) infections, according to a report in Cancer Prevention Research, a journal of the American Association for Cancer Research. H. pylori infections are one of the most common bacterial infections worldwide and are a major cause of stomach cancer.

The cancer protective effects of sulforaphane, a phytochemical from broccoli, have been known for almost two decades, but this is the first study to show an effect of broccoli in humans on the bacterial infection that leads to stomach cancer. In this study, researchers enrolled 48 Helicobacter-infected Japanese men and women and randomly assigned them to eat 70 grams of fresh broccoli sprouts daily for eight weeks or an equivalent amount of alfalfa sprouts.

“Broccoli has recently entered the public awareness as a preventive dietary agent. This study supports the emerging evidence that broccoli sprouts may be able to prevent cancer in humans, not just in lab animals,” said Jed Fahey, Sc.D., a faculty research associate in the Department of Pharmacology at Johns Hopkins School of Medicine.

Researchers assessed the severity of H. pylori infection at enrollment, and again at four and eight weeks using standard breath, serum and stool tests. H. pylori levels were significantly lower at eight weeks on all three measures among those patients who had eaten broccoli sprouts, while they remained the same for patients who had eaten alfalfa sprouts.

A reduction in H. pylori is expected to lead to a reduction in stomach cancer due to their well-established cause-and-effect link. Stomach cancer has a grim prognosis and is the second most common and the second deadliest cancer worldwide.

Source: American Association for Cancer Research

CHAMPAIGN, Ill. — Chemists at the University of Illinois have created a simple and inexpensive molecular technique that replaces an expensive atomic force microscope for studying what happens to small molecules when they are stretched or compressed.

The researchers use stiff stilbene, a small, inert structure, as a molecular force probe to generate well-defined forces on various molecules, atom by atom.

“By pulling on different pairs of atoms, we can explore what happens when we stretch a molecule in different ways,” said chemistry professor Roman Boulatov. “That information tells us a lot about the properties of fleeting structures called transition states that govern how, and how fast, chemical transformations occur.”

Boulatov, research associate Qing-Zheng Yang, postdoctoral researcher Daria Khvostichenko, and graduate students Zhen Huang and Timothy Kucharski describe the molecular force probe and present early results in a paper accepted for publication in Nature Nanotechnology. The paper is to be posted on the journal’s Web site on Sunday (March 29).

Similar to the force that develops when a rubber band is stretched, restoring forces occur in parts of molecules when they are stretched. Those restoring forces contain information about how much the molecule was distorted, and in what direction.

The molecular force probe allows reaction rates to be measured as a function of the restoring force in a molecule that has been stretched or compressed.

This information is essential for developing a chemomechanical kinetic theory that explains how force affects rates of chemical transformations.

Such a theory will help researchers better understand a host of complex phenomena, from the operation of motor proteins that underlie the action of muscles, to the propagation of cracks in polymers and the mechanisms by which living cells sense forces in their surroundings.

“Localized reactions offer the best opportunity to gain fundamental insights into the interplay of reaction rates and molecular restoring forces,” Boulatov said, “but these reactions are extremely difficult to study with a microscopic force probe.”

Microscopic force probes, which are utilized by atomic force microscopes, are much too large to grab onto a single pair of atoms. Measuring microns in size, the probe tips contact many atoms at once, smearing experimental results.

“By replacing microscopic force probes with small molecules like stiff stilbene, we can study the relationship between restoring force and reaction rate for localized reactions,” Boulatov said. “The more accurately we know where our probe acts, the better control we have over the distortion, and the easier it is to interpret the results.”

Using conventional methods, Boulatov and his students first attach stiff stilbene to a molecule they wish to study. Then they irradiate the resulting molecular assembly with visible light. The light causes the stilbene to change from a fully relaxed shape to one that exerts a desired force on the molecule. The chemists then measure the reaction rate of the molecule as a function of temperature, which reveals details of what caused the reaction to accelerate.

One type of chemical transformation the researchers studied is the breaking of one strong (covalent) chemical bond at a time. The experimental results were sometimes counterintuitive.

“Unlike a rubber band, which will always break faster when stretched, pulling on some chemical bonds doesn’t make them break any faster; and sometimes it’s a bond that you don’t pull on that will break instead of the one you do pull,” Boulatov said. “That’s because experiences in the macroscopic world do not map particularly well to the molecular world.”

Molecules do not live in a three-dimensional world, Boulatov said. Molecules populate a multi-dimensional world, where forces applied to a pair of atoms can act in more than three dimensions.

“Even small molecules will stretch and deform in many different ways,” Boulatov said, “making the study of molecular forces even more intriguing.”

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Source: University of Illinois at Urbana-Champaign

Increased schooling across sub-Saharan Africa may be lowering new HIV infections among younger adults, according to sociologists, suggesting a shift in a decades-long trend where formal education is considered an AIDS risk factor.

While education in general has a positive impact on global public health, when it comes to HIV and AIDS in sub-Saharan Africa, education has had a completely opposite effect.

During the early stages of the HIV pandemic in the region, the disease passed unnoticed amidst the onslaught of other infections. When scientists took a closer look at the deadly new disease, they found that more often males with a higher than average education were contracting the disease.

“Before the 1990s, in the impoverished regions of sub-Saharan Africa, even modest amounts of education afforded males higher income, more leisure time, and, for some males, greater access to commercial sex workers,” explained David Baker, professor of education and sociology at Penn State and lead author of the study. “HIV-infected higher-status males then spread the infection to both educated and uneducated women, which moved the disease into the general population.”

Baker and his Penn State colleagues John Collins and Juan Leon, both graduate students, believe that information about AIDS that was already percolating in wealthier countries did not get to sub-Saharan Africa until the mid 1990s. AIDS was seen as a homosexual, urban disease and either neglect or active misinformation campaigns in some African countries ensured that the preventative effects of education never took root. But among younger people in the region, formal education is emerging as a major preventative factor against new infections. They report their findings in the current issue of the UNESCO journal Prospects.

“There needs to be a very clear message, both to the donor community and to governments in sub-Saharan Africa, that expanding quality primary schools has to be a topmost priority,” said Collins, co-author of the study. “It will not only have economic benefits, but also health benefits.”

To find what has happened recently to the link between formal education and HIV infections, the researchers analyzed data from surveys previously undertaken in 11 countries across the region between 2003 and 2005. They specifically looked at males ages 15 to 24, 25 to 34, and older than 35.

Survey participants were tested for HIV infection and interviewed about their education, social status, and sexual behavior.

The researchers argued that because the youngest members of the oldest group — the 35 and older — became sexually mature in the late 1980s, when there was little or no information about AIDS, higher education would show as a risk factor instead of a social vaccine.

Statistical analyses of the data suggest that in all 11 countries formal education had no effect on HIV infections in the oldest group, probably because many older adults, educated and uneducated have already been exposed to the virus and many have died. However, having some schooling did reduce the risk of HIV infections in the youngest group by up to 34 percent in Guinea, Malawi, Senegal, Cameroon, Ghana, and Kenya.

“At 24 years, the oldest member of this young group reached sexual maturity in the mid 1990s, when there was already widespread knowledge that HIV and AIDS could be contracted through unprotected sex and intravenous drug use,” explained Baker.

The researchers hypothesize that, reasoning skills gained in school by younger adults play a preventative role against HIV in sub-Saharan Africa.

“More educated people have the cognitive tools to make better sense out of facts presented to them,” explained Baker. “We have shown that when there is sufficient information, and no misinformation, people with education adopt healthy strategies to avoid infections.”

The Penn State researchers caution that while a large number of deaths in the early stages of the HIV pandemic could mask the true effects of education in the oldest group, the findings hold key policy implications for turning education into a social vaccine against HIV in sub-Saharan Africa.

According to Baker, AIDS is a complicated disease and it can only be tackled effectively by providing people with an everyday, accurate working theory of how the disease is transmitted. “We are telling the governments that increased literacy is an explicit prevention strategy against HIV because it will help stop pandemics,” he said.

The Penn State researcher also asks non-governmental organizations to reevaluate their educational programs.

“The kind of information being supplied by NGOs is scandalous because it is so simplistic and minimalist, particularly for low-educated people, that they are not going to figure this disease out in time to prevent their own infection,” Baker added.

Source: Penn State

Credit: Duke University

DURHAM, N.C. — Scientists have used a popular kids swimming pool game to guide their development of a system for controlling moving robots that can autonomously detect and capture other moving targets.

Engineers from Duke University and the University of New Mexico have used the simple pursuit-evasion game “Marco Polo” to solve a complex problem — namely, how to create a system that allows robots to not only “sense” a moving target, but intercept it.

Such systems have broad applications, ranging from security systems to track unwanted intruders like enemy ships or burglars, to systems that create radiation or environmental hazard maps, or even track endangered species.

Rafael Fierro is an associate professor of electrical engineering at the University of New Mexico.

Credit: University of New Mexico

The main challenge facing researchers is developing the artificial intelligence to control the robots and their sensors without direct human guidance.

The goal of the game “Marco Polo” is for the person who is “it” to tag another person, who then becomes the new pursuer. However, pursuers must keep their eyes closed. At any time, the pursuer can call out “Marco,” and everyone else must respond by saying “Polo.” In this way, the pursuer can gradually estimate where the targets are in the pool and where they might go.

“Games give us a good way of making these highly complex problems easier to visualize,” said Silvia Ferrari, assistant professor of mechanical engineering and materials science at Duke’s Pratt School of Engineering. Ferrari and colleague Rafael Fierro, associate professor of electrical engineering at the University of New Mexico, published the results from their latest experiments online in the Journal on Control and Optimization, a publication of the Society for Industrial and Applied Mathematics.

“Just as in ‘Marco Polo,’ we needed to create a way that permits mobile robots to detect other moving objects and make predictions about where the targets might go,” Ferrari said. “When done efficiently, the mobile sensor switches from pursuit mode to capture mode in the shortest amount of time.”

Ferrari’s laboratory had already developed a similar type of algorithm, known as cell decomposition, in which space is broken down into a series of distinct cells. Past experiments allowed a robot to move through space without colliding with stationary obstacles.

The latest experiments included not only robots equipped with camera sensors, but also stationary camera sensors, which allowed for “coverage” of all the cells within the space.

“The idea is that multiple sensors are deployed in the space to cooperatively detect moving targets within that space,” Fierro said. “As the sensor makes more detections, it is better able to predict the likely path of the intruder. The ultimate path taken by the robot sensor is one that maximizes the probability of detection and minimizes the distance needed to capture the target.”

While the security and military applications of this type of detection system are obvious, Fierro also points out that the new algorithms can be used in other ways to detect targets that aren’t necessarily intruders.

“Targets could be completely different things, like mines or explosives, or chemical or radiation leaks,” Fierro said. “The robots can use their sensors to keep track of the detected locations and build a ‘map’ to let people know where to go or not to go.”

The algorithms could also be used to help explain natural phenomena, such as the behaviors of members of a wolf pack as they chase and capture their prey.

The latest experiments were conducted at the University of New Mexico and involved intruders moving in straight lines at a constant speed.

“We are now developing algorithms that will more closely mimic the real world by giving intruders the ability to take evasive actions,” Ferrari said. “The other main issue is to ensure that all the different mobile sensors can communicate with each other at all times and coordinate their activities based on that communication.”

Source: Duke University