Wal-Mart finds safety issues at Bangladesh factories

The Wal-Mart company logo is seen outside a Wal-Mart Stores Inc company distribution center in Bentonville, Arkansas June 6, 2013.

Credit: Reuters/Rick Wilking

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NASA spacecraft finds plastic ingredient on Saturn's moon Titan

n">(Reuters) - NASA's Cassini spacecraft has found propylene, a chemical used to make household plastic containers, on Saturn's moon Titan, the space agency said.

"This is the first definitive detection of the plastic ingredient on any moon or planet, other than Earth," NASA said.

A small amount of propylene was identified in Titan's lower atmosphere by Cassini's composite infrared spectrometer, which measures heat radiation, the agency reported in Monday's edition of the Astrophysical Journal Letters.

By isolating the same signal at various altitudes within the lower atmosphere, researchers identified the chemical's unique thermal fingerprint with a high degree of confidence, NASA said.

"This chemical is all around us in everyday life, strung together in long chains to form a plastic called polypropylene," said Conor Nixon, a scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the paper.

"That plastic container at the grocery store with the recycling code 5 on the bottom - that's polypropylene."

The chemical is also used to make car bumpers and other consumer products.

The discovery could help scientists understand the "chemical zoo" that makes up Titan's hazy brownish atmosphere, said Scott Edgington, Cassini's deputy project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency.

(Reporting by Jane Sutton; Editing by Maureen Bavdek)

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Snorkeler finds rare giant oarfish off California coast

By Tim Gaynor

Tue Oct 15, 2013 6:18pm EDT

n">(Reuters) - A California marine instructor's leisurely weekend snorkel turned into the discovery of a lifetime when she found the carcass of a massive, eel-like creature of a species thought to have inspired legends of giant sea serpents.

Catalina Island Marine Institute instructor Jasmine Santana spotted the 18-foot (5.5-meter) oarfish, which is as thick as a man's torso, while snorkeling in clear waters off the island's coast on Sunday afternoon, the institute said.

The creatures are found in all temperate to tropical waters, but because they dive to depths of 3,000 feet, they are rarely seen and remain largely unstudied. Little is known about their behavior, the nonprofit educational institute said.

"Jasmine Santana was shocked to see (a) half-dollar sized eye staring at her from the sandy bottom," the institute said in a statement. "Her first reaction was to approach with caution, until she realized that it was dead."

Oarfish have a pug face, a crest running the length of their bodies and a skeleton of bone rather than cartilage common to fish species like sharks. They can grow up to a length of 56 feet. Because of their strange appearance, they are believed to have inspired legends of giant sea serpents.

It took a group of 15 adults to pull the fish's massive carcass up the beach to a better viewing area, the institute said. Its longest serving employee, Mark Johnson, could not believe his eyes. "In 32 years here," he said. "I have never seen anything like this!"

The body of the fish appeared almost perfectly intact. The institute sent tissue samples and video footage to a University of California at Santa Barbara fish expert, and is awaiting a final determination on the species.

A spokesman for Guided Discoveries, the educational nonprofit that operates programs on Catalina Island, said the sea creature's skeleton will likely be put on display for visitors.

(This story has been refiled to fix meter conversion in paragraph five)

(Reporting by Tim Gaynor; Editing by Cynthia Johnston and Gunna Dickson)

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NASA spacecraft finds plastic ingredient on Saturn's moon Titan

n">(Reuters) - NASA's Cassini spacecraft has found propylene, a chemical used to make household plastic containers, on Saturn's moon Titan, the space agency said.

"This is the first definitive detection of the plastic ingredient on any moon or planet, other than Earth," NASA said.

A small amount of propylene was identified in Titan's lower atmosphere by Cassini's composite infrared spectrometer, which measures heat radiation, the agency reported in Monday's edition of the Astrophysical Journal Letters.

By isolating the same signal at various altitudes within the lower atmosphere, researchers identified the chemical's unique thermal fingerprint with a high degree of confidence, NASA said.

"This chemical is all around us in everyday life, strung together in long chains to form a plastic called polypropylene," said Conor Nixon, a scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the paper.

"That plastic container at the grocery store with the recycling code 5 on the bottom - that's polypropylene."

The chemical is also used to make car bumpers and other consumer products.

The discovery could help scientists understand the "chemical zoo" that makes up Titan's hazy brownish atmosphere, said Scott Edgington, Cassini's deputy project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency.

(Reporting by Jane Sutton; Editing by Maureen Bavdek)

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Men with erection problems are three times more likely to have inflamed gums, study finds

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NASA Finds Sea Ice Driving Arctic Air Pollutants

Bromine explosion on March 13, 2008 across the western Northwest Territories in Canada looking toward the Mackenzie Mountains at the horizon, which prevented the bromine from crossing over into Alaska. Image credit: NASA/JPL-Caltech/University of Bremen
› Full image and caption March 01, 2012

PASADENA, Calif. - Drastic reductions in Arctic sea ice in the last decade may be intensifying the chemical release of bromine into the atmosphere, resulting in ground-level ozone depletion and the deposit of toxic mercury in the Arctic, according to a new NASA-led study.

The connection between changes in the Arctic Ocean's ice cover and bromine chemical processes is determined by the interaction between the salt in sea ice, frigid temperatures and sunlight. When these mix, the salty ice releases bromine into the air and starts a cascade of chemical reactions called a "bromine explosion." These reactions rapidly create more molecules of bromine monoxide in the atmosphere. Bromine then reacts with a gaseous form of mercury, turning it into a pollutant that falls to Earth's surface.

Bromine also can remove ozone from the lowest layer of the atmosphere, the troposphere. Despite ozone's beneficial role blocking harmful radiation in the stratosphere, ozone is a pollutant in the ground-level troposphere.

A team from the United States, Canada, Germany, and the United Kingdom, led by Son Nghiem of NASA's Jet Propulsion Laboratory in Pasadena, Calif., produced the study, which has been accepted for publication in the Journal of Geophysical Research- Atmospheres. The team combined data from six NASA, European Space Agency and Canadian Space Agency satellites; field observations and a model of how air moves in the atmosphere to link Arctic sea ice changes to bromine explosions over the Beaufort Sea, extending to the Amundsen Gulf in the Canadian Arctic.

"Shrinking summer sea ice has drawn much attention to exploiting Arctic resources and improving maritime trading routes," Nghiem said. "But the change in sea ice composition also has impacts on the environment. Changing conditions in the Arctic might increase bromine explosions in the future."

The study was undertaken to better understand the fundamental nature of bromine explosions, which first were observed in the Canadian Arctic more than two decades ago. The team of scientists wanted to find if the explosions occur in the troposphere or higher in the stratosphere.

Nghiem's team used the topography of mountain ranges in Alaska and Canada as a "ruler" to measure the altitude at which the explosions took place. In the spring of 2008, satellites detected increased concentrations of bromine, which were associated with a decrease of gaseous mercury and ozone. After the researchers verified the satellite observations with field measurements, they used an atmospheric model to study how the wind transported the bromine plumes across the Arctic.  

The model, together with satellite observations, showed the Alaskan Brooks Range and the Canadian Richardson and Mackenzie mountains stopped bromine from moving into Alaska's interior. Since most of these mountains are lower than 6,560 feet (2,000 meters), the researchers determined the bromine explosion was confined to the lower troposphere.

"If the bromine explosion had been in the stratosphere, 5 miles [8 kilometers] or higher above the ground, the mountains would not have been able to stop it and the bromine would have been transported inland," Nghiem said.

After the researchers found that bromine explosions occur in the lowest level of the atmosphere, they could relate their origin to sources on the surface. Their model, tracing air rising from the salty ice, tied the bromine releases to recent changes in Arctic sea ice that have led to a much saltier sea ice surface.

In March 2008, the extent of year-round perennial sea ice eclipsed the 50-year record low set in March 2007, shrinking by 386,100 square miles (one million square kilometers) -- an area the size of Texas and Arizona combined. Seasonal ice, which forms over the winter when seawater freezes, now occupies the space of the lost perennial ice. This younger ice is much saltier than its older counterpart because it has not had time to undergo processes that drain its sea salts. It also contains more frost flowers -- clumps of ice crystals up to four times saltier than ocean waters -- providing more salt sources to fuel bromine releases.

Nghiem said if sea ice continues to be dominated by younger saltier ice, and Arctic extreme cold spells occur more often, bromine explosions are likely to increase in the future.

Nghiem is leading an Arctic field campaign this month that will provide new insights into bromine explosions and their impacts. NASA's Bromine, Ozone, and Mercury Experiment (BROMEX) involves international contributions by more than 20 organizations. The new studies will complement those of a previously conducted NASA field campaign, Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS), which is providing scientists with valuable data for studies of bromine.

This study was funded by NASA, the National Oceanic and Atmospheric Administration, the National Science Foundation, the Office of Naval Research, the International Polar Year Program, Environment Canada, the Natural Sciences and Engineering Council of Canada, the European Space Agency, the State of Bremen, the German Aerospace Center, and the European Organisation for the Exploitation of Meteorological Satellites.

For more information about NASA programs, visit: http://www.nasa.gov .

JPL is managed for NASA by the California Institute of Technology in Pasadena.
Additional media contacts: Sandra Hines, University of Washington, 206-543-2080; John Burrows, University of Bremen, 011-49-421-218-62100; Isabelle Compagnon, Environment Canada, 819-953-6959; Sean Moore, University of Manitoba, 204-474-7963; Lt. Cmdr. Michael Vancas, National Ice Center, 301-817-3941; Katja Tholen-Ihnen, University of Hamburg, 011-49-0-40-42838-7596.

Alan Buis 818-354-0474
Jet Propulsion Laboratory, Pasadena, Calif.
Alan.buis@jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
Dwayne.c.brown@nasa.gov

2012-054

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Study Finds Severe Climate Jeopardizing Amazon Forest

At left, the extent of the 2005 megadrought in the western Amazon rainforests during the summer months of June, July and August as measured by NASA satellites. The most impacted areas are shown in shades of red and yellow. The circled area in the right panel shows the extent of the forests that experienced slow recovery from the 2005 drought, with areas in red and yellow shades experiencing the slowest recovery. Image credit: NASA/JPL-Caltech/GSFC
› Larger image January 17, 2013

PASADENA, Calif. - An area of the Amazon rainforest twice the size of California continues to suffer from the effects of a megadrought that began in 2005, finds a new NASA-led study. These results, together with observed recurrences of droughts every few years and associated damage to the forests in southern and western Amazonia in the past decade, suggest these rainforests may be showing the first signs of potential large-scale degradation due to climate change.

An international research team led by Sassan Saatchi of NASA's Jet Propulsion Laboratory, Pasadena, Calif., analyzed more than a decade of satellite microwave radar data collected between 2000 and 2009 over Amazonia. The observations included measurements of rainfall from NASA's Tropical Rainfall Measuring Mission and measurements of the moisture content and structure of the forest canopy (top layer) from the Seawinds scatterometer on NASA's QuikScat spacecraft.

The scientists found that during the summer of 2005, more than 270,000 square miles (700,000 square kilometers, or 70 million hectares) of pristine, old-growth forest in southwestern Amazonia experienced an extensive, severe drought. This megadrought caused widespread changes to the forest canopy that were detectable by satellite. The changes suggest dieback of branches and tree falls, especially among the older, larger, more vulnerable canopy trees that blanket the forest.

While rainfall levels gradually recovered in subsequent years, the damage to the forest canopy persisted all the way to the next major drought, which began in 2010. About half the forest affected by the 2005 drought - an area the size of California - did not recover by the time QuikScat stopped gathering global data in November 2009 and before the start of a more extensive drought in 2010.

"The biggest surprise for us was that the effects appeared to persist for years after the 2005 drought," said study co-author Yadvinder Malhi of the University of Oxford, United Kingdom. "We had expected the forest canopy to bounce back after a year with a new flush of leaf growth, but the damage appeared to persist right up to the subsequent drought in 2010."

Recent Amazonian droughts have drawn attention to the vulnerability of tropical forests to climate change. Satellite and ground data have shown an increase in wildfires during drought years and tree die-offs following severe droughts. Until now, there had been no satellite-based assessment of the multi-year impacts of these droughts across all of Amazonia. Large-scale droughts can lead to sustained releases of carbon dioxide from decaying wood, affecting ecosystems and Earth's carbon cycle.

The researchers attribute the 2005 Amazonian drought to the long-term warming of tropical Atlantic sea surface temperatures. "In effect, the same climate phenomenon that helped form hurricanes Katrina and Rita along U.S. southern coasts in 2005 also likely caused the severe drought in southwest Amazonia," Saatchi said. "An extreme climate event caused the drought, which subsequently damaged the Amazonian trees."

Saatchi said such megadroughts can have long-lasting effects on rainforest ecosystems. "Our results suggest that if droughts continue at five- to 10-year intervals or increase in frequency due to climate change, large areas of the Amazon forest are likely to be exposed to persistent effects of droughts and corresponding slow forest recovery," he said. "This may alter the structure and function of Amazonian rainforest ecosystems."

The team found that the area affected by the 2005 drought was much larger than scientists had previously predicted. About 30 percent (656,370 square miles, or 1.7 million square kilometers) of the Amazon basin's total current forest area was affected, with more than five percent of the forest experiencing severe drought conditions. The 2010 drought affected nearly half of the entire Amazon forest, with nearly a fifth of it experiencing severe drought. More than 231,660 square miles (600,000 square kilometers) of the area affected by the 2005 drought were also affected by the 2010 drought. This "double whammy" by successive droughts suggests a potentially long-lasting and widespread effect on forests in southern and western Amazonia.

The drought rate in Amazonia during the past decade is unprecedented over the past century. In addition to the two major droughts in 2005 and 2010, the area has experienced several localized mini-droughts in recent years. Observations from ground stations show that rainfall over the southern Amazon rainforest declined by almost 3.2 percent per year in the period from 1970 to 1998. Climate analyses for the period from 1995 to 2005 show a steady decline in water availability for plants in the region. Together, these data suggest a decade of moderate water stress led up to the 2005 drought, helping trigger the large-scale forest damage seen following the 2005 drought.

Saatchi said the new study sheds new light on a major controversy that existed about how the Amazon forest responded following the 2005 megadrought. Previous studies using conventional optical satellite data produced contradictory results, likely due to the difficulty of correcting the optical data for interference by clouds and other atmospheric conditions.

In contrast, QuikScat's scatterometer radar was able to see through the clouds and penetrate into the top few meters of vegetation, providing daily measurements of the forest canopy structure and estimates of how much water the forest contains. Areas of drought-damaged forest produced a lower radar signal than the signals collected over healthy forest areas, indicating either that the forest canopy is drier or it is less "rough" due to damage to or the death of canopy trees.

Results of the study were published recently in the Proceedings of the National Academy of Sciences. Other participating institutions included UCLA; University of Oxford, United Kingdom; University of Exeter, Devon, United Kingdom; National Institute for Space Research, Sao Jose dos Campos, Sao Paulo, Brazil; Boston University, Mass.; and NASA's Ames Research Center, Moffett Field, Calif.

For more on NASA's scatterometry missions, visit: http://winds.jpl.nasa.gov/index.cfm . You can follow JPL News on Facebook at: http://www.facebook.com/nasajpl and on Twitter at: http://www.twitter.com/nasajpl . The California Institute of Technology in Pasadena manages JPL for NASA.

Alan Buis 818-354-0474
Jet Propulsion Laboratory, Pasadena, Calif.
Alan.buis@jpl.nasa.gov

2013-025

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New Study Finds Ocean Warmed Significantly Since 1993

The international science team analyzed nine different estimates of heat content in the upper ocean, based on ocean temperature data from a global array of more than 3,200 Argo free-floating profiling floats and longer data records from expendable bathythermographs dropped from ships. Image credit: International Argo Project
› Larger view May 19, 2010

The upper layer of Earth's ocean has warmed since 1993, indicating a strong climate change signal, according to a new international study co-authored by oceanographer Josh Willis of NASA's Jet Propulsion Laboratory, Pasadena, Calif. The energy stored is enough to power nearly 500 100-watt light bulbs for each of the roughly 6.7 billion people on the planet continuously over the 16-year study period.

"We are seeing the global ocean store more heat than it gives off," said John Lyman, an oceanographer at the National Oceanic and Atmospheric Administration's Joint Institute for Marine and Atmospheric Research, who led the study that analyzed nine different estimates of heat content in the upper ocean from 1993 to 2008.

The team combined the estimates to assess the size and certainty of growing heat storage in the ocean. Their findings will be published in the May 20 edition of the journal Nature. The scientists are from NASA, NOAA, the Met Office Hadley Centre in the United Kingdom, the University of Hamburg in Germany and the Meteorological Research Institute in Japan.

"The ocean is the biggest reservoir for heat in the climate system," said Willis. "So as the planet warms, we're finding that 80 to 90 percent of the increased heat ends up in the ocean."

A warming ocean is a direct cause of global sea level rise, since seawater expands and takes up more space as it heats up. The scientists say that this expansion accounts for about one-third to one-half of global sea level rise.

Combining multiple estimates of heat in the upper ocean – from the surface to about 610 meters (2,000 feet) down – the team found a strong multi-year warming trend throughout the world's ocean. According to measurements by an array of autonomous free-floating ocean floats called Argo, as well as by earlier devices called expendable bathythermographs, or XBTs, that were dropped from ships to obtain temperature data, ocean heat content has increased over the last 16 years.

The team notes that there are still some uncertainties and some biases.

"The XBT data give us vital information about past changes in the ocean, but they are not as accurate as the more recent Argo data," said Gregory Johnson, an oceanographer at NOAA's Pacific Marine Environmental Laboratory. "However, our analysis of these data gives us confidence that on average, the ocean has warmed over the past decade and a half, signaling a climate imbalance."

Data from the array of Argo floats -- deployed by NOAA and other U.S. and international partners -- greatly reduce the uncertainties in estimates of ocean heat content over the past several years, the team said. There are now more than 3,200 Argo floats distributed throughout the world's ocean sending back information via satellite on temperature, salinity, currents and other ocean properties.

For more information, see http://www.noaanews.noaa.gov/stories2010/20100519_ocean.html

Alan Buis (818) 354-0474
Jet Propulsion Laboratory, Pasadena, Calif.
Alan.buis@jpl.nasa.gov

2010-169

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NASA Space Telescope Finds Fewer Asteroids Near Earth

NEOWISE observations indicate that there are at least 40 percent fewer near-Earth asteroids in total that are larger than 330 feet, or 100 meters. Our solar system's four inner planets are shown in green, and our sun is in the center. Each red dot represents one asteroid. Object sizes are not to scale. Image credit: NASA/JPL-Caltech
› Larger image | › See animation September 29, 2011

PASADENA, Calif. -- New observations by NASA's Wide-field Infrared Survey Explorer, or WISE, show there are significantly fewer near-Earth asteroids in the mid-size range than previously thought. The findings also indicate NASA has found more than 90 percent of the largest near-Earth asteroids, meeting a goal agreed to with Congress in 1998.

Astronomers now estimate there are roughly 19,500 -- not 35,000 -- mid-size near-Earth asteroids. Scientists say this improved understanding of the population may indicate the hazard to Earth could be somewhat less than previously thought. However, the majority of these mid-size asteroids remain to be discovered. More research also is needed to determine if fewer mid-size objects (between 330 and 3,300-feet wide) also mean fewer potentially hazardous asteroids, those that come closest to Earth.

The results come from the most accurate census to date of near-Earth asteroids, the space rocks that orbit within 120 million miles (195 million kilometers) of the sun into Earth's orbital vicinity. WISE observed infrared light from those in the middle to large-size category. The survey project, called NEOWISE, is the asteroid-hunting portion of the WISE mission. Study results appear in the Astrophysical Journal.

"NEOWISE allowed us to take a look at a more representative slice of the near-Earth asteroid numbers and make better estimates about the whole population," said Amy Mainzer, lead author of the new study and principal investigator for the NEOWISE project at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "It's like a population census, where you poll a small group of people to draw conclusions about the entire country."

WISE scanned the entire celestial sky twice in infrared light between January 2010 and February 2011, continuously snapping pictures of everything from distant galaxies to near-Earth asteroids and comets. NEOWISE observed more than 100 thousand asteroids in the main belt between Mars and Jupiter, in addition to at least 585 near Earth.

WISE captured a more accurate sample of the asteroid population than previous visible-light surveys because its infrared detectors could see both dark and light objects. It is difficult for visible-light telescopes to see the dim amounts of visible-light reflected by dark asteroids. Infrared-sensing telescopes detect an object's heat, which is dependent on size and not reflective properties.

Though the WISE data reveal only a small decline in the estimated numbers for the largest near-Earth asteroids, which are 3,300 feet (1 kilometer) and larger, they show 93 percent of the estimated population have been found. This fulfills the initial "Spaceguard" goal agreed to with Congress. These large asteroids are about the size of a small mountain and would have global consequences if they were to strike Earth. The new data revise their total numbers from about 1,000 down to 981, of which 911 already have been found. None of them represents a threat to Earth in the next few centuries. It is believed that all near-Earth asteroids approximately 6 miles (10 kilometers) across, as big as the one thought to have wiped out the dinosaurs, have been found.

"The risk of a really large asteroid impacting the Earth before we could find and warn of it has been substantially reduced," said Tim Spahr, the director of the Minor Planet Center at the Harvard Smithsonian Center for Astrophysics in Cambridge, Mass.

The situation is different for the mid-size asteroids, which could destroy a metropolitan area if they were to impact in the wrong place. The NEOWISE results find a larger decline in the estimated population for these bodies than what was observed for the largest asteroids. So far, the Spaceguard effort has found and is tracking more than 5,200 near-Earth asteroids 330 feet or larger, leaving more than an estimated 15,000 still to discover. In addition, scientists estimate there are more than a million unknown smaller near-Earth asteroids that could cause damage if they were to impact Earth.

"NEOWISE was just the latest asset NASA has used to find Earth's nearest neighbors," said Lindley Johnson, program executive for the Near Earth Object Observation Program at NASA Headquarters in Washington. "The results complement ground-based observer efforts over the past 12 years. These observers continue to track these objects and find even more."

WISE is managed and operated by JPL for NASA's Science Mission Directorate in Washington. The principal investigator, Edward Wright, is at the University of California, Los Angeles. The WISE science instrument was built by the Space Dynamics Laboratory in Logan, Utah, and the spacecraft was built by Ball Aerospace and Technologies Corp. in Boulder, Colo. Science operations and data processing occur at the Infrared Processing and Analysis Center at the California Institute of Technology.

For more information about the mission, visit: http://www.nasa.gov/wise .

Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
Whitney.clavin@jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown@nasa.gov

2011-304

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Jury finds Exxon liable for $236.4 million in U.S. pollution suit

The Exxon corporate logo is pictured at a gas station in Arlington, Virginia January 31, 2012.

Credit: Reuters/Jason Reed

By Jason McLure

LITTLETON, New Hampshire | Tue Apr 9, 2013 5:32pm EDT

LITTLETON, New Hampshire (Reuters) - A New Hampshire jury on Tuesday found Exxon Mobil Corp liable for $236.4 million in a civil lawsuit that charged the oil company had polluted groundwater in the state with a gasoline additive used to reduce smog in the 1970s and 1980s.

Following a three-month trial, jurors deliberated less than two hours before finding that the world's largest publicly traded oil company acted negligently in contaminating the groundwater with the additive MTBE, said Jessica Grant, a lawyer who represented the state.

"We're very pleased that the jury held Exxon accountable for the harm its defective product caused to the state's groundwater resources and that they also held Exxon responsible for its negligence," she said.

Originally filed in New Hampshire court in 2003, the state charged that Exxon and other major oil companies knew that MTBE was likely to contaminate groundwater and was more difficult to clean up than other pollutants. Some damages from the suit will help pay for the costs of testing and cleaning affected water supplies.

Exxon vowed to appeal.

"MTBE worked as intended to improve our air quality and the benefits of its use substantially outweighed the known risks," said spokeswoman Rachael Moore. "MTBE contamination in New Hampshire is rapidly decreasing and the state's current system for cleaning up gasoline spills ensures safe drinking water."

The U.S. Environmental Protection Agency today considers MTBE a potential human carcinogen, though much of the research on the chemical has focused on the health effects of inhaling it rather than drinking it. New Hampshire banned MTBE in the state in 2007.

Exxon was the only one of the 22 original defendants in the original suit to go to trial. Other defendants either had the suits against them dismissed or agreed to settlements.

Those included Canada-based Irving Oil Co, which agreed to pay $57 million last year, and Venezuela's state-owned Citgo Petroleum Corp, which struck a $16 million agreement as the trial began.

The three-month trial on the suit, filed in state court, was moved to the state's federal courthouse in Concord to accommodate the large number of witnesses, lawyers and exhibits. The jury found that MTBE contamination had caused $816 million in damages in the state. Exxon's market share of 29 percent was used to compute damages, Grant said.

(Reporting by Jason McLure; Editing by Scott Malone and Tim Dobbyn)

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Surfaces inspired by geckos can be switched between adhesive and non-adhesive states, study finds

Adhesives inspired by the gecko can be made to switch on and off reversibly and repeatedly. The key design parameters for these materials are identified in a study published in Journal of the Royal Society Interface today.

Geckos use thread-like fibres on their hands and feet to stick to surfaces. Synthetic gecko-inspired adhesives rely on the same fibrillar structures. In both cases nonchemical adhesion is created by concentrating the intermolecular forces between two bodies.

In 2007 researchers from the Leibniz Institute for New Materials, Germany created adhesive materials which could be switched on and off using differences in pressure. Now the same research group have shown precisely how to do this by adjusting the shape of the surface fibres.

Dr Paretkar and his team identified the key parameters that influence adhesion switchability; namely the fibrillar contact shape, radius, aspect ratio, orientation and the applied compressive load. They found that adding flap structures to the ends of the fibrils significantly enhanced how effectively adhesiveness could be switched on and off.

The synthetic adhesive materials are 'switched' on by pressing them against a surface and 'switched' off by increasing their pressure on the surface, which causes loss of adhesion.

The findings mean that new materials can be developed in which adhesiveness can be precisely controlled. This study was conducted using biocompatible material; if the same results can be repeated in biodegradable materials then they could be used during delicate medical procedures in which small objects have to be moved around. These adhesive materials could also be scaled-up and used as fillers in operations such as repairing a damaged ear drum without the use of stitches.

More information: Paretkar, D. et al. Preload responsive adhesion: effects of aspect ratio, tip shape, and alignment, Journal of the Royal Society Interface. dx.doi.org/10.1098/rsif.2013.0171

Journal reference: Journal of the Royal Society Interface

Provided by The Royal Society

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