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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.

THE HAGUE, June 24 (Xinhua) -- Bird flu was discovered at a poultry farm in the central Dutch province of Flevoland, the Ministry of Agriculture said Friday.It said the virus discovered was a mild variant. The farm's 47,000 chickens were slaughtered to prevent the virus turning into a contagious and deadly variant.It remains uncertain whether the chickens were infected with the high or low pathologene H7 variant. The low pathologene version can mutate into a high pathologen, which is extremely transmittable.Poultry from other farms in a zone of three kilometres of the contaminated farm will be tested. A prohibition of transport for poultry, eggs and poultry manure has been set.

WASHINGTON, June 15 (Xinhua) -- Using the deepest X-ray image ever taken, astronomers found the first direct evidence that massive black holes were common in the early universe, the U.S. National Aeronautics and Space Administration (NASA) said Wednesday in a statement.The discovery from NASA's Chandra X-ray Observatory shows that very young black holes grew more aggressively than previously thought, in tandem with the growth of their host galaxies.By pointing Chandra at a patch of sky for more than six weeks, astronomers obtained what is known as the Chandra Deep Field South (CDFS). When combined with very deep optical and infrared images from NASA's Hubble Space Telescope, the new Chandra data allowed astronomers to search for black holes in 200 distant galaxies, from when the universe was between about 800 million to 950 million years old."Until now, we had no idea what the black holes in these early galaxies were doing, or if they even existed," said Ezequiel Treister of the University of Hawaii, lead author of the study to appear Thursday in journal Nature. "Now we know they are there, and they are growing like gangbusters."The super-sized growth means that the black holes in the CDFS are less extreme versions of quasars -- very luminous, rare objects powered by material falling onto supermassive black holes. However, the sources in the CDFS are about a hundred times fainter and the black holes are about a thousand times less massive than the ones in quasars.The observations found that between 30 and 100 percent of the distant galaxies contain growing supermassive black holes. Extrapolating these results from the small observed field to the full sky, there are at least 30 million supermassive black holes in the early universe. This is a factor of 10,000 larger than the estimated number of quasars in the early universe."It appears we've found a whole new population of baby black holes," said co-author Kevin Schawinski of Yale University. "We think these babies will grow by a factor of about a hundred or a thousand, eventually becoming like the giant black holes we see today almost 13 billion years later."

BEIJING, Aug. 13 (Xinhua) -- Chinese rating agency Dagong Global Credit Rating Co. on Saturday defended its AAA rating given to the Ministry of Railways, which has been under public fire over a train collision last month.The ministry received the long-term credit rating after launching on Monday its first bond sales since the crash on July 23 that killed 40 people near the Wenzhou city of eastern Zhejiang province.It sold 20 billion yuan worth of three-month bills on offer in the interbank market, with a yield of 5.55 percent, a relatively high rate for short-term government paper.The rating was assigned because of the ministry's status as a government agency backed by the central government revenue, its sufficient capital flows and strong financing ability, Dagong said in an email to Xinhua.The agency made the elaboration in response to market doubts as the ministry is already heavily indebted and the accident has stirred up skepticism about the its credibility and the safety of fast-expanding railways.Adding to doubts is that the AAA rating of the ministry is even a notch above China's local currency debt rating of AA+, which was also rated by Dagong.Government data showed the ministry's debts exceeded 2 trillion yuan (313 billion U.S. dollars) as of the end of June, raising its debt ratio to 58.53 percent, slightly up from the end of the first quarter of this year.Dagong said in the statement that the debt-to-asset ratio is medium level, lower than the alert line for the ministry which is 75 percent.The ministry has large-scale assets of good quality and relatively large room for fund-raising, Dagong said.The ministry has "extremely strong" repayment ability as it is backed by the state's credit, Dagong said, referring it as one of the three authorities that are allowed to issue bonds, along with the Ministry of Finance and the People's Bank of China.In July, the ministry issued 20 billion yuan of one-year commercial papers with a coupon rate of 5.18 percent, but only 18.73 billion yuan of the total was bought.Analysts said it has become more difficult for the ministry to borrow money because of tightened market liquidity and concerns over the ministry's debt burden.China's top four banks said at the end of last month that they will continue to offer loans to the ministry based on market conditions and risk appraisal. Credit from the four largest state-owned banks including the Industrial and Commercial Bank of China and the Construction Bank of China has been the major source funding the construction of China's fast-growing railways in recent years.

BEIJING, July 19 (Xinhuanet) -- Lifestyle changes such as exercise, eating healthily and not smoking could reduce the chances of having Alzheimer’s disease by half, researchers said in a study quoted by news reports Tuesday.Hundreds of thousands of patients could potentially avoid the devastating illness by simply changing bad habits, according to the study published in the journal Lancet NeurologyFor the first time, scientists have calculated the extent to which certain lifestyle traits -- including lack of exercise, smoking and obesity -- all contributed to the disease.Researchers found that in the Western world, an inactive “couch potato” lifestyle was the most important possible cause.Smoking, obesity in middle-age, high blood pressure and diabetes all increased the risk as they cause damage to blood vessels in the brain, leading to death of brain cells. Together, the modifiable risk factors contributed to 50 percent of Alzheimer’s cases worldwide.The researchers want to carry out more work to find out how many people can prevent the disease by making small changes to their lifestyle.