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WASHINGTON, June 23 (Xinhua) -- NASA's next Mars rover has completed the journey from its California birthplace to Florida in preparation for launch this fall, the U.S. space agency said Thursday in a statement.The Mars Science Laboratory (MSL) rover, also known as Curiosity, arrived Wednesday at NASA's Kennedy Space Center aboard an Air Force C-17 transport plane. It was accompanied by the rocket-powered descent stage that will fly the rover during the final moments before landing on Mars.The rover's aeroshell -- the protective covering for the trip to the Red Planet -- and the cruise stage, which will guide it to Mars, arrived at Kennedy last month. The mission is targeted to launch from Cape Canaveral Air Force Station between Nov. 25 and Dec. 18. The car-size rover will land on Mars in August 2012.The rover and other spacecraft components will undergo more testing before mission staff stack them and fuel the onboard propulsion systems. Curiosity should be enclosed in its aeroshell for the final time in September and delivered to Kennedy's Launch Complex 41 in early November for integration with a United Launch Alliance Atlas V rocket.Curiosity is about twice as long and more than five times as heavy as any previous Mars rover. Its 10 science instruments include two for ingesting and analyzing samples of powdered rock delivered by the rover's robotic arm. During a prime mission lasting one Martian year -- nearly two Earth years -- researchers will use the rover's tools to study whether the landing region has had environmental conditions favorable for supporting microbial life and favorable for preserving clues about whether life existed.

LOS ANGELES, July 28 (Xinhua) -- Mainly due to rampant obesity, Americans' life expectancy is one-and-a-half-year shorter than that of Western Europeans on the average, according to a new study published on Thursday.But 40 years ago, Americans could expect to live slightly longer than Europeans, said the study jointly conducted by researchers from University of Southern California (USC), the Harvard School of Public Health and the RAND Corp., a non-profit think tank.In addition to Western Europeans, Americans also die younger than the residents of most other developed nations, according to the study appearing in the July issue of Social Science & Medicine.The life-expectancy disparity, which begins around the age of 50, stems from higher levels of middle-age obesity and obesity-related chronic diseases, such as hypertension and diabetes, said the study.In the first half of the last century, average life expectancy increased by saving more babies, said author Dana Goldman, director of the Schaeffer Center for Health Policy and Economics at the USC."But now it is reduction in mortality among the elderly, rather than the young, that propels increases in life expectancy," he said. "The question is whether 'being American' is an independent mortality risk factor."If 50-year-old U.S. adults could be as healthy as Europeans, it could save Medicare and Medicaid 632 billion dollars by 2050, the study said.Though the transition to better health initially raises expenditures, the researchers estimate that by 2050 healthcare savings from health improvements among the middle age could total more than 1.1 trillion dollars."The international life expectancy gap appears much easier to explain than gaps within countries: there is no American-specific effect on longevity beyond differences in disease at age 50," said Darius Lakdawalla, an associate professor in the USC School of Policy, Planning and Development.

WASHINGTON, June 7 (Xinhua) -- Advanced hepatitis C patients with chronic liver disease may benefit from drinking coffee during treatment, according to a new study published Tuesday in Gastroenterology, the official journal of the American Gastroenterological Association Institute.The study shows that patients who received peginterferon plus ribavirin treatment and who drank three or more cups of coffee per day were two times more likely to respond to treatment than non- drinkers.Among non-drinkers, 46 percent had an early virologic response; 26 percent had no detectable serum hepatitis C virus (HCV) ribonucleic acid at week 20; 22 percent had no detectable serum at week 48; and 11 percent had a sustained virologic response. In contrast, the corresponding proportions for those who drank three or more cups of coffee per day were 73 percent, 52 percent, 49 percent and 26 percent, respectively."Coffee intake has been associated with a lower level of liver enzymes, reduced progression of chronic liver disease and reduced incidence of liver cancer," said Neal Freedman, of the National Cancer Institute and lead author of this study. "Although we observed an independent association between coffee intake and virologic response to treatment, this association needs replication in other studies."Approximately 70 to 80 percent of individuals exposed to HCV become chronically infected. Worldwide, these individuals are estimated to number between 130 and 170 million. Higher coffee consumption has been associated with slower progression of pre- existing liver disease and lower risk of liver cancer. However, the relationship with response to anti-HCV treatment had not been previously evaluated.

LOS ANGELES, June 23 (Xinhua) -- The sun and its inner planets may have formed differently than previously thought, NASA's Jet Propulsion Laboratory (JPL) said on Thursday.Data revealed differences between the sun and planets in oxygen and nitrogen, which are two of the most abundant elements in our solar system, said JPL in Pasadena, Los Angeles.Although the difference is slight, the implications could help determine how our solar system evolved, JPL said.NASA researchers drew the conclusion after analyzing samples returned by NASA's 2004 Genesis mission, according to JPL.The air on Earth contains three different kinds of oxygen atoms which are differentiated by the number of neutrons they contain. Nearly 100 percent of oxygen atoms in the solar system are composed of O-16, but there are also tiny amounts of more exotic oxygen isotopes called O-17 and O-18. Researchers studying the oxygen of Genesis samples found that the percentage of O-16 in the sun is slightly higher than on Earth or on other terrestrial planets. The other isotopes' percentages were slightly lower."We found that Earth, the moon, as well as Martian and other meteorites which are samples of asteroids, have a lower concentration of the O-16 than does the sun," said Kevin McKeegan, a Genesis co-investigator from University of California, Los Angeles (UCLA) and the lead author of one of two papers published this week in Science journal. "The implication is that we did not form out of the same solar nebula materials that created the sun -- just how and why remains to be discovered." Another paper detailed differences between the sun and planets in the element nitrogen. Like oxygen, nitrogen has one isotope, N- 14, that makes up nearly 100 percent of the atoms in the solar system, but there is also a tiny amount of N-15. Researchers studying the same samples saw that when compared to Earth's atmosphere, nitrogen in the sun and Jupiter has slightly more N-14, but 40 percent less N-15. Both the sun and Jupiter appear to have the same nitrogen composition. As is the case for oxygen, Earth and the rest of the inner solar system are very different in nitrogen."These findings show that all solar system objects including the terrestrial planets, meteorites and comets are anomalous compared to the initial composition of the nebula from which the solar system formed," said Bernard Marty, a Genesis co- investigator from Petrographic and Geochemical Research Center in Fracne and the lead author of the other new Science paper. " Understanding the cause of such a heterogeneity will impact our view on the formation of the solar system."Data were obtained from analysis of samples Genesis collected from the solar wind, or material ejected from the outer portion of the sun. This material can be thought of as a fossil of our nebula because the preponderance of scientific evidence suggests that the outer layer of our sun has not changed measurably for billions of years."The sun houses more than 99 percent of the material currently in our solar system, so it's a good idea to get to know it better, " said Genesis Principal Investigator Don Burnett of the California Institute of Technology, Pasadena, California. "While it was more challenging than expected, we have answered some important questions, and like all successful missions, generated plenty more."Genesis was launched in August 2000. The spacecraft traveled to Earth's L1 Lagrange Point about one million miles from Earth, where it remained for 886 days between 2001 and 2004, passively collecting solar-wind samples.JPL managed the Genesis mission for NASA's Science Mission Directorate, Washington. The Genesis mission was part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Alasca.

LOS ANGELES, July 18 (Xinhua) -- The spacecraft Dawn of the National Aeronautics and Space Administration (NASA) has returned the first close-up image of the giant asteroid Vesta after entering its orbit for the first time last week, the Jet Propulsion Laboratory (JPL) announced on Monday.The image taken for navigation purposes shows Vesta in greater detail than ever before, said JPL in Pasadena, California.On July 15, Dawn became the first probe to enter orbit around an object in the main asteroid belt between Mars and Jupiter.When Vesta captured Dawn into its orbit, there were approximately 9,900 miles (about 16,000 kilometers) between the spacecraft and the asteroid.Vesta is 330 miles (about 530 kilometers) in diameter and the second most massive object in the asteroid belt.NASA's Dawn spacecraft obtained this image with its framing camera on July 17, 2011. It was taken from a distance of about 9,500 miles (15,000 kilometers) away from the protoplanet Vesta. Each pixel in the image corresponds to roughly 0.88 miles (1.4 kilometers). Ground- and space-based telescopes have obtained images of Vesta for about two centuries, but they have not been able to see much detail on its surface."We are beginning the study of arguably the oldest extant primordial surface in the solar system," said Dawn principal investigator Christopher Russell from the University of California, Los Angeles, which is responsible for Dawn's mission science. " This region of space has been ignored for far too long. So far, the images received to date reveal a complex surface that seems to have preserved some of the earliest events in Vesta's history, as well as logging the onslaught that Vesta has suffered in the intervening eons."Vesta is thought to be the source of a large number of meteorites that fall to Earth. Vesta and its new NASA neighbor, Dawn, are currently approximately 117 million miles (about 188 million kilometers) away from Earth. The Dawn team will begin gathering science data in August.Observations will provide unprecedented data to help scientists understand the earliest chapter of the solar system and pave the way for future human space missions, according to JPL."Dawn slipped gently into orbit with the same grace it has displayed during its years of ion thrusting through interplanetary space," said Marc Rayman, Dawn chief engineer and mission manager at NASA's JPL. "It is fantastically exciting that we will begin providing humankind its first detailed views of one of the last unexplored worlds in the inner solar system."Although orbit capture is complete, the approach phase will continue for about three weeks. During approach, the Dawn team will continue a search for possible moons around the asteroid; obtain more images for navigation; observe Vesta's physical properties; and obtain calibration data.In addition, navigators will measure the strength of Vesta's gravitational tug on the spacecraft to compute the asteroid's mass with much greater accuracy than has been previously available, according to JPL.Dawn will spend one year orbiting Vesta, then travel to a second destination, the dwarf planet Ceres, arriving in February 2015. The mission to Vesta and Ceres is managed by JPL for the agency's Science Mission Directorate in Washington.Dawn is a project of the directorate's Discovery Program, which is managed by NASA's Marshall Space Flight Center in Huntsville, Alaska.

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