WASHINGTON, June 25 (UPI) -- U.S. space agency engineers said final testing has started for the Lunar Crater Observation and Sensing Satellite that's to be launched later this year.

The National Aeronautics and Space Administration satellite, nicknamed LCROSS, is designed to confirm the presence or absence of water ice in a permanently shadowed lunar crater.

NASA said a thermal vacuum test completed earlier this month subjected the spacecraft to 13 1/2 days of heating and cooling cycles, with temperatures ranging from 230 degrees Fahrenheit to minus 40 degrees Fahrenheit.

After launch from the Kennedy Space Center in Florida, LCROSS and its Atlas V rocket's Centaur upper stage will execute a fly-by of the moon and enter into an elongated Earth orbit to position the satellite for impact on a lunar pole. On final approach, the spacecraft and the Centaur will separate. The Centaur will strike the surface of the moon, creating a debris plume that will rise above the surface. Four minutes later, LCROSS will fly through the debris plume, collecting and relaying data back to Earth before it also crashes onto the lunar surface and creates a second debris plume.

Scientists will observe both impacts from Earth to gather additional information.

New brain injury therapy is created

WEST LAFAYETTE, Ind., June 25 (UPI) -- U.S. medical scientists say they have developed an injectable treatment for severe brain injuries that are due to blunt force trauma.

Purdue University researchers Andrew Koob and Richard Borgens said they discovered such an injury can be reduced by application of a simple polymer --polyethylene glycol, or PEG -- mixed in sterile water and injected into the blood stream.

Koob and Borgens performed experiments in rats that showed PEG was effective in limiting damage if administered within four hours after the head injury. However, if treatment was delayed for a further two hours, the beneficial effects were lost.

"These data suggest that PEG may be clinically useful to victims of traumatic brain injury if delivered as rapidly as possible after an injury," said Borgens. "Such a treatment could feasibly be carried out at the scene of an accident where PEG could be delivered as a component of IV fluids, thus reducing long term brain injury."

The study is reported in the Journal of Biological Engineering.

Study: Dry Tortugas has signs of recovery

MIAMI, June 25 (UPI) -- A team of 38 U.S. research divers has completed a 20-day biennial census, measuring how the protected status of the Dry Tortugas is working.

In what is called an unprecedented collaboration, researchers from the Rosenstiel School of Marine and Atmospheric Science, the National Oceanic and Atmospheric Administration, the Florida Fish and Wildlife Conservation Commission, the National Park Service, the Reef Environmental Education Foundation and the University of North Carolina at Wilmington conducted more than 1,700 scientific dives in the Dry Tortugas -- a small group of islands at the tip of the Florida Keys, about 70 miles west of Key West.

The dives at the Tortugas Ecological Reserve and Dry Tortugas National Park's Research Natural Area were designed to determine how the region's ecosystem is rebounding from decades of overfishing and environmental changes.

"We are very encouraged to see stocks have slowly begun to recuperate since the implementation of 'no-take' marine protected areas in the region," said the expedition's chief scientist, Rosenstiel Professor Jerry Ault. "We noted particular improvements in the numbers of snapper, grouper, and coral recruits."

A full report is expected to be issued in September.

Scientists ID new Alzheimer's disease gene

MANHASSET, N.Y., June 25 (UPI) -- U.S. medical scientists say they have identified a gene that puts people at risk for developing Alzheimer's disease.

Philippe Marambaud of the Feinstein Institute for Medical Research and Fabien Campagne of the Weill Medical College at Cornell University said the calcium channel modulator gene holds promise as a potentially new way to treat or even prevent Alzheimer's disease.

They said they found the risk gene called CALHM1 strongly expressed in the hippocampus -- a brain region necessary for learning and memory. The researchers said CALHM1 leads to a partial loss of function, which means less calcium gets into a cell, thereby weakening signals normally regulated by calcium. They determined one of those signals controls the levels of amyloid peptides, the building blocks of the characteristic disease plaques.

Using DNA from deceased U.S. Alzheimer's victims and age-matched controls, along with DNA samples from patients in France, Italy and the United Kingdom, the researchers ran tests on 3,404 samples. They discovered people having the genetic variant had 1.5 times higher risk of developing Alzheimer's.

The study that included French researcher Jean Charles Lambert is detailed in the journal Cell.