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Archive - May 18, 2012

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Rabies Evolution Rate in Bats Varies with Location

The rate at which the rabies virus evolves in bats may depend heavily upon the ecological traits of its hosts, according to researchers at the University of Georgia (UGA), the U.S. Centers for Disease Control and Prevention and Katholieke Universiteit (KU) Leuven in Belgium. Their study, published May 17, 2012 in PLoS Pathogens, found that the host's geographical location was the most accurate predictor of the viral rate of evolution. Rabies viruses in tropical and sub-tropical bat species evolved nearly four times faster than viral variants in bats in temperate regions. "Species that are widely distributed can have different behaviors in different geographical areas," said Dr. Daniel Streicker, a postdoctoral associate in the UGA Odum School of Ecology and the study's leader. "Bats in the tropics are active year-round, so more rabies virus transmission events occur per year. Viruses in hibernating bats, on the other hand, might lose up to six months' worth of opportunities for transmission." Understanding the relationship between host ecology and viral evolution rates could shed light on the transmission dynamics of other viruses, such as influenza, that occur across regions, infect multiple host species, or whose transmission dynamics are impacted by anthropogenic change. The team's findings could eventually help public health officials better predict when rabies virus transmission could happen in different environments and as environments change, but Dr. Streicker cautions that more research into the rabies virus genome and bats' overwintering ecology is needed. "If viral evolution is faster, it could potentially lead to greater genetic diversity in crucial parts of the viral genome that allow it to shift hosts," he said. "For rabies, we don't yet know what those are, so identifying them will be key.

Scientists Generate Electricity from Viruses

Imagine charging your phone as you walk, thanks to a paper-thin generator embedded in the sole of your shoe. This futuristic scenario is now a little closer to reality. Scientists from the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a way to generate power using harmless viruses that convert mechanical energy into electricity. The scientists tested their approach by creating a generator that produces enough current to operate a small liquid-crystal display. It works by tapping a finger on a postage stamp-sized electrode coated with specially engineered viruses. The viruses convert the force of the tap into an electric charge. This generator is the first to produce electricity by harnessing the piezoelectric properties of a biological material. Piezoelectricity is the accumulation of a charge in a solid in response to mechanical stress. The milestone could lead to tiny devices that harvest electrical energy from the vibrations of everyday tasks such as shutting a door or climbing stairs. It also points to a simpler way to make microelectronic devices. That's because the viruses arrange themselves into an orderly film that enables the generator to work. Self-assembly is a much-sought-after goal in the finicky world of nanotechnology. The scientists describe their work in an article published on May 13, 2012 in Nature Nanotechnology. "More research is needed, but our work is a promising first step toward the development of personal power generators, actuators for use in nano-devices, and other devices based on viral electronics," says Dr. Seung-Wuk Lee, a faculty scientist in Berkeley Lab's Physical Biosciences Division and a UC Berkeley associate professor of bioengineering. He conducted the research with a team that includes Dr.

Researchers Identify Key Genes and Prototype Predictive Test for Schizophrenia

An Indiana University (IU)-led research team, along with a group of national and international collaborators, has identified and prioritized a comprehensive group of genes most associated with schizophrenia that together can generate a score indicating whether an individual is at higher or lower risk of developing the disease. Using a convergent functional genomics approach that incorporates a variety of experimental techniques, the scientists were also able to apply a panel of their top genes to data from other studies of schizophrenia and successfully identify which patients had been diagnosed with schizophrenia and which had not, according to a report published online on May 15, 2012 by the journal Molecular Psychiatry. Evaluating the biological pathways in which the genes are active, the researchers also proposed a model of schizophrenia as a disease emerging from a mix of genetic variations affecting brain development and neuronal connections along with environmental factors, particularly stress. "At its core, schizophrenia is a disease of decreased cellular connectivity in the brain, precipitated by environmental stress during brain development, among those with genetic vulnerability," said principal investigator Alexander B. Niculescu III, M.D., Ph.D., associate professor of psychiatry and medical neuroscience at the IU School of Medicine and director of the Laboratory of Neurophenomics at the Institute of Psychiatric Research at the IU School of Medicine. "For first time we have a comprehensive list of the genes that have the best evidence for involvement in schizophrenia," said Dr. Niculescu, who is also staff psychiatrist and investigator at the Richard L. Roudebush Veterans Affairs Medical Center.