Mars orbiter completes primary mission
PASADENA, Calif., Dec. 15 (UPI) -- The U.S. space agency says its Mars Reconnaissance Orbiter has completed its primary, two-year science mission.
National Aeronautics and Space Administration scientists said the spacecraft has returned 73 terabits of data -- more than all earlier Mars missions combined.
The orbiter initially moved into position 186 miles above the surface of Mars in October 2006, subsequently conducting approximately 10,000 targeted observation sequences of high-priority areas. NASA scientists said the orbiter has imaged nearly 40 percent of the planet at a resolution that can reveal house-sized objects in detail, 1 percent in enough detail to see desk-sized features.
It also has covered nearly 60 percent of Mars in mineral mapping bands at stadium-size resolution, assembled nearly 700 daily global weather maps and dozens of atmospheric temperature profiles, along with radar profiles of the subsurface and the interior of the polar caps.
"These observations are now at the level of detail necessary to test hypotheses about when and where water has changed Mars and where future missions will be most productive as they search for habitable regions on Mars," said Richard Zurek, a project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif.
The orbiter now begins a new phase as Mars makes another orbit around the sun, which takes approximately two Earth years.
New B cell lymphoma therapy is presented
HOUSTON, Dec. 15 (UPI) -- U.S. medical scientists say they've found indolent B cell lymphoma patients respond well to a new three-drug combination therapy.
The researchers from the M.D. Anderson Cancer Center at the University of Texas said the drug combo also spares patents prolonged and potentially lethal suppression of blood production in the bone marrow.
The drugs -- pentostatin, cyclophosphamide and rituximab -- together provide the same remission rate as other combinations, but with minimal long-term bone marrow suppression, said Dr. Felipe Samaniego, an associate professor in M. D. Anderson's department of lymphoma and melanoma.
The researchers said bone marrow suppression, or myelosuppression, leads to production of fewer red blood cells, white blood cells and platelets. When prolonged, it can lead to myelodysplastic syndrome, which comprises several conditions that cause potentially lethal insufficient blood production.
"The worst outcome of long-term myelosuppression for indolent B cell lymphoma patients is myelodysplastic syndrome," Samaniego said. "In this study, out of 80 patients, none developed MDS. The PCR combination is a very promising therapy for indolent B cell lymphoma."
The study that included Drs. Michelle Fanale, Barbara Pro, F.B. Hagemeister, Peter McLaughlin, Jorge Romaguera, Sattva Neelapu, Maria Anna Rodriguez, Luis Fayad, Anas Younes and Larry Kwak was presented last week in San Francisco during the annual meeting of the American Society of Hematology.
Study: Collagen VI can protect against AD
SAN FRANCISCO, Dec. 15 (UPI) -- U.S. scientists say they've discovered a type of collagen can protect brain cells against amyloid-beta proteins thought to cause Alzheimer's disease.
Researchers from the Gladstone Institute of Neurological Disease, the University of California-San Francisco and Stanford University say that while the functions of collagens in cartilage and muscle are well established, it had not been known that collagen VI is made by neurons in the brain and it can fulfill important neuroprotective functions.
The scientists led by Dr. Lennart Mucke determined collagen VI is increased in brain tissues of Alzheimer's patients.
"We first noticed the increase in collagen VI in the brain of AD mouse models, which inspired us to look for it in the human condition and to define its role in the disease," said Mucke.
"These findings were really surprising and exciting to us because nobody knew anything about collagen VI in the brain," said Dr. Jason Cheng, co-lead author of the study.
The research was reported in a recent edition of the journal Nature N Neuroscience.
Another dinosaur extinction theory offered
PRINCETON, N.J., Dec. 15 (UPI) -- A U.S. geosciences professor says dinosaurs died gradually from climate change caused by volcanic eruptions in India and not because of a meteor strike.
Gerta Keller of Princeton University admits her theory contradicts the long-held hypothesis that dinosaurs died due to climate change after a giant meteor hit the Yucatan region of Mexico.
Keller bases her theory on her National Science Foundation-funded field work in India and Mexico that uncovered geologic evidence that the mass extinction and the meteor impact occurred at different times.
"The Chicxulub impact hit the Yucatan about 300,000 years before the mass extinction that included the dinosaurs and, therefore, could not have caused it," Keller said.
Keller and her team instead found the mass extinction coincided with the end of the main phase of India's Deccan eruptions, suggesting volcanism killed the dinosaurs.
Keller and her colleagues will present their findings during the December 2009 American Geophysical Union meeting in San Francisco. The work will also be included in an upcoming History Channel feature "What Really Killed the Dinosaurs."
