Study: Jellyfish help oceans mix it up
PASADENA, Calif., July 30 (UPI) -- Jellyfish and other small swimming marine creatures can have a huge impact on ocean mixing, researchers in California report.
Increasingly, scientists have been thinking about the possible role ocean animals may play in larger-scale ocean mixing, the process by which layers of water interact to distribute heat, nutrients and gases throughout the oceans, California Institute of Technology researchers said Thursday in a release.
"The perspective we usually take is how the ocean -- by its currents, temperature, and chemistry -- is affecting animals," says John Dabiri, a Caltech bio-engineer who, along with Caltech graduate student Kakani Katija, discovered the new mechanism. "But there have been increasing suggestions that the inverse is also important, how the animals themselves, via swimming, might impact the ocean environment."
Dabiri's and Katija's findings indicating the inverse to be true were published in Thursday's issue of Nature.
Dabiri said oceanographers had dismissed the idea that animals having a significant effect on ocean mixing, believing that the viscosity of water would balance out any turbulence created by small, drifting, animals.
"Results from this study will change some of our long-held conceptions about mixing processes in the oceans," says David Garrison, director of the National Science Foundation's biological oceanography program, which funded the research.
Space shuttle to return to Earth Friday
HOUSTON, July 30 (UPI) -- NASA officials say they won't know for certain whether U.S.space shuttle Endeavour will land as scheduled on Friday until about two hours before touchdown.
Officials will evaluate weather conditions at the Kennedy Space Center in Florida about two hours before permitting Endeavour and its seven-member crew to land shortly after noon EDT, NASA said on its Web site.
If weather bars a return to Kennedy on Friday, the backup landing site at Edwards Air Force Base in California will be activated Saturday for consideration as well, officials said.
After touching down, the astronauts will undergo physical examinations and meet with their families, NASA said.
Study: Comets once had watery interiors
CARDIFF, Wales, July 30 (UPI) -- Comets held a vast ocean of water in their interiors during the first million years after their formation, a study by a Welsh university says.
The liquid environment of early comets, along with the large quantity of organic matter already discovered, would have provided great culture for primitive bacteria to grow and multiply, researchers at Cardiff University said Thursday in a release.
The team calculated the thermal history of comets after they were formed from interstellar and interplanetary dust about 4.5 billion years ago. A supernova injected radioactive material into the Earth's solar system in its infancy and some of the radioactive material became incorporated in the comets, the researchers theorized.
Chandra Wickramasinghe, Janaki Wickramasinghe and Max Wallis said heat emitted from radioactivity warms initially frozen material of comets to produce subsurface oceans that existed for 1 million years.
"These calculations, which are more exhaustive than any done before, leave little doubt that a large fraction of the 100 billion comets in our solar system did indeed have liquid interiors in the past," Wickramasinghe said.
Their findings were included in a paper published recently in the International Journal of Astrobiology.
FTC tries to block device-maker's purchase
WASHINGTON, July 30 (UPI) -- The U.S. Federal Trade Commission is seeking to block a cardiac device-maker's proposed $282 million acquisition plans.
Cardiac device-maker Thoratec Corp., of Pleasanton, Calif., is trying to acquire outstanding shares of HeartWare International, based in Framingham, Mass. The FTC has filed an administrative complaint in federal district court seeking to permanently stop the acquisition, announced in February, ModernHealthcare.com reported Thursday.
FTC officials said Thoratec is the only device-maker with a Food and Drug Administration-approved left-ventricular device on the market, and acquiring HeartWare, which has a competing device positioned for approval, would prevent price and quality competition.
"We can't have healthcare reform that truly benefits American consumers unless we have competition," FTC Bureau of Competition Director Richard Feinstein said.
