Low Zika risk for travelers to Olympics in Brazil, study finds

The Zika virus poses a negligible health threat to the international community during the summer Olympic Games that begin next month in Rio de Janeiro, Brazil, according to researchers at Yale School of Public Health (YSPH).In a worst-case scenario, an estimated 3 to 37 of the thousands of athletes, spectators, media, and vendors traveling to Rio for the Olympics will bring the Zika virus back to their home countries, the researchers concluded.

Distant volcanic eruptions foster saguaro cacti baby booms

One hundred and thirty years ago, the volcano Krakatoa erupted in what is now Indonesia, unleashing a cataclysm locally and years of cool temperatures and rain globally. On the far side of the world, a bumper crop of saguaro cacti were getting their start in life in Arizona's Sonoran Desert. Many of the large exemplars of the famous cacti standing spiny and tall with arms akimbo in the Southwest today started their lives in the shadow of the 1883 eruption.Biogeographer Taly Drezner believes that distant volcanic paroxysms and the emergence of bountiful saguaro age-mate cohorts are connected. Volcanic climate perturbations that delivered disastrously cold and stormy weather to much of the Northern Hemisphere generated a combination of conditions in the Sonoran Desert that were just right for the delicate young cacti. Drezner will present her research on the first known example of regional population effects on a species from volcanic eruptions in distant parts of the world on 9 August 2016 at the 101st Annual Meeting of the Ecological Society of America, gathering this year in Fort Lauderdale, Florida.

NASA spies major Hurricane Georgette

Hurricane Georgette is a major hurricane in the Eastern Pacific Ocean. NASA-NOAA's Suomi NPP satellite provided a visible image of the powerful storm that showed a clear eye.On July 24, at 21:20 UTC (5:20 p.m. EDT) the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA's Suomi NPP satellite captured an image of Hurricane Georgette in the eastern Pacific Ocean that showed an open eye with strong bands of thunderstorms circling the center.Shortly after Suomi NPP captured the visible image, Georgette's maximum sustained winds had increased to near 130 mph (215 kph) and Georgette became a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale.

Marine carbon sinking rates confirm importance of polar oceans

About the same amount of atmospheric carbon that goes into creating plants on land goes into the bodies of tiny marine plants known as plankton. When these plants die and sink, bacteria feed on their sinking corpses and return their carbon to the seawater. When plankton sink deep enough before being eaten, this carbon is taken out of circulation as a greenhouse gas to remain trapped in the deep ocean for centuries.How much of this happens in different regions of the ocean would seem like an academic question, except during an era when humanity is spewing carbon dioxide into the air at record-high levels and wondering where all that carbon will go in the future.A University of Washington study published this week (July 25) in the Proceedings of the National Academy of Sciences uses a new approach to get a global picture of the fate of marine carbon. It finds that the polar seas export organic carbon to the deep sea, where it can no longer trap heat from the sun, about five times as efficiently as in other parts of the ocean.

Spiders spin unique phononic material

New discoveries about spider silk could inspire novel materials to manipulate sound and heat in the same way semiconducting circuits manipulate electrons, according to scientists at Rice University, in Europe and in Singapore.A paper in Nature Materials today looks at the microscopic structure of spider silk and reveals unique characteristics in the way it transmits phonons, quasiparticles of sound.The research shows for the first time that spider silk has a phonon band gap. That means it can block phonon waves in certain frequencies in the same way an electronic band gap - the basic property of semiconducting materials - allows some electrons to pass and stops others.The researchers wrote that their observation is the first discovery of a "hypersonic phononic band gap in a biological material."

Global Economy Has Reduced Its Energy Intensity by One-Third Since 1990

The global economy is becoming less energy intensive, using fewer fossil fuels to power productivity and economic growth, according to new data from the U.S. Department of Energy. Global energy intensity — a measure of energy consumption per unit of gross domestic product (GDP) — has decreased nearly one-third since 1990, the agency said. The U.S., for example, burned 5,900 British thermal units per dollar of GDP in 2015, compared to 6,600 BTUs in 2010.

Unlocking the secret to cheaper solar power

As climate change garners more attention around the world, scientists at the University of Virginia and Cornell University have made critical advances in understanding the physical properties of an emerging class of solar cells that have the potential to dramatically lower the cost of solar energy.Solar cells remain a focal point of scientific investigation because the sun offers the most abundant source of energy on earth. The concern, however, with conventional solar cells made from silicon is their cost. Even with recent improvements, they still require a significant amount of electricity and industrial processing to be manufactured.In 2009, energy researchers turned their attention to a class of materials called "metal halide perovskites," or MHPs. They are sprayed on like paint onto solid objects, says Joshua Choi, an assistant professor of chemical engineering at the University of Virginia. As the solution dries, the MHPs crystallize into a thin film that can be used to capture energy in a solar cell.

Why Americans waste so much food

Even though American consumers throw away about 80 billion pounds of food a year, only about half are aware that food waste is a problem. Even more, researchers have identified that most people perceive benefits to throwing food away, some of which have limited basis in fact.A study published today in PLOS ONE is just the second peer-reviewed large-scale consumer survey about food waste and is the first in the U.S. to identify patterns regarding how Americans form attitudes on food waste.

Mars rover's laser can now target rocks all by itself

New software is enabling ChemCam, the laser spectrometer on NASA's Curiosity Mars rover, to select rock targets autonomously -- the first time autonomous target selection is available for an instrument of this kind on any robotic planetary mission. Developed jointly at Los Alamos National Laboratory and the Research Institute in Astrophysics and Planetology in Toulouse, France, the ChemCam (chemistry and camera) instrument aboard Curiosity "zaps" rocks on Mars and analyzes their chemical make-up. While most ChemCam targets are still selected by scientists, the rover itself now chooses multiple targets per week."This new capability will give us a chance to analyze even more rock and soil samples on Mars," said Roger Wiens, principal investigator for ChemCam at Los Alamos. "The science team is not always available to pick samples for analysis. Having a smarter rover that can pick its own samples is completely in line with self-driving cars and other smart technologies being implemented on Earth."

Trees' surprising role in the boreal water cycle quantified

Approximately 25 to 50 percent of a living tree is made up of water, depending on the species and time of year. The water stored in trees has previously been considered just a minor part of the water cycle, but a new study by University of Alaska Fairbanks scientists shows otherwise.Research published this week in Nature Scientific Reports is the first to show that the uptake of snowmelt water by deciduous trees represents a large and previously overlooked aspect of the water balance in boreal watersheds. The study was led by Jessica Young-Robertson, who worked with other scientists from the National Weather Service and UAF's International Arctic Research Center and Geophysical Institute.