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WASHINGTON, Aug. 31 (Xinhua) -- Astronomers using NASA's Chandra X-ray Observatory discovered the first pair of supermassive black holes in a spiral galaxy similar to the Milky Way, NASA announced Wednesday.Approximately 160 million light years from Earth, the pair is the nearest known such phenomenon.The black holes are located near the center of the spiral galaxy NGC 3393. Separated by only 490 light years, the black holes are likely the remnant of a merger of two galaxies of unequal mass a billion or more years ago.Both of the supermassive black holes are heavily obscured by dust and gas, which makes them difficult to observe in optical light. Because X-rays are more energetic, they can penetrate this obscuring material. Chandra's X-ray spectra show clear signatures of a pair of supermassive black holes."If this galaxy weren't so close, we'd have no chance of separating the two black holes the way we have," said Pepi Fabbiano of the Harvard-Smithsonian Center for Astrophysics, who led the study that appeared Wednesday in on-line issue of the journal Nature. "Since this galaxy was right under our noses by cosmic standards, it makes us wonder how many of these black hole pairs we've been missing."Previous observations in X-rays and at other wavelengths indicated that a single supermassive black hole existed in the center of NGC 3393. However, a long look by Chandra allowed the researchers to detect and separate the dual black holes. Both black holes are actively growing and emitting X-rays as gas falls towards them and becomes hotter.When two equal-sized spiral galaxies merge, astronomers think it should result in the formation of a black hole pair and a galaxy with a disrupted appearance and intense star formation. A well-known example is the pair of supermassive black holes in NGC 6240, which is located about 330 million light years from Earth.However, NGC 3393 is a well-organized spiral galaxy, and its central bulge is dominated by old stars. These are unusual properties for a galaxy containing a pair of black holes.

WASHINGTON, July 26 (Xinhua) -- The District of Columbia Department of Health (DOH) in the U.S. announced Tuesday that it has positively identified the West Nile Virus in mosquito samples in the District.This is the first time this summer the West Nile Virus has been identified in the U.S. capital."Residents should take caution as mosquitoes have the potential to transmit West Nile Virus to humans, and it is important for residents to take the necessary steps to avoid contracting the virus," DOH said in a statement.West Nile Virus is mainly an infection of birds, but on occasions an infected mosquito may spread it to humans. The virus is not transmitted directly from birds to humans and the risk of infection is low. In human infections, the virus generally causes no symptoms, or may cause mild flu-like symptoms.Senior citizens and people with weak immune systems are considered high risk for suffering the worst from the disease, officials said."People with a higher risk of infection should wear long- sleeved shirts, long pants, and apply insect repellent with DEET or other mosquito repellents to exposed skin according to manufacturer's directions. For children, they should use a product with DEET concentration of less than 30 percent," DOH said.

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.

PARIS, June 19 (Xinhua) -- Commercial Aircraft Corporation of China Ltd. (Comac) on Sunday set up its European office in Paris, the second overseas branch after its U.S. office, marking a new step for China's aviation industry in opening-up and international exchanges."The establishment of Comac Europe office is very significant. It represents the strategic cooperation between China and France and will deepen the two sides' collaboration in aerospace and all areas concerned," Chinese Ambassador Kong Quan said at an opening ceremony, citing Europe's influence in global aerospace industry and civil aviation market."Taking self-dependent innovation as the strategic cornerstone, Comac meanwhile actively conducts international cooperation and draws upon advanced technologies and experience in global civil aviation industry...," Comac President Jin Zhuanglong said.French Secretary of State for Transport Thierry Mariani (4th L), Chinese Ambassador to France Kong Quan (3rd L) and General Manager of the Commercial Aircraft Corporation of China (COMAC) Jin Zhuanglong (2nd R) attend the unveiling ceremony of COMAC Europe Office in Paris, France, June 19, 2011. The COMAC Europe Office was offically opened here Sunday.The Chinese aerospace manufacturer has built up cooperative relationship and partnership with dozens of enterprises and institutions in many countries and regions since its establishment in May 2008 in Shanghai.Regional jet ARJ21 and the trunkliner C919 are two flagship products of the young Chinese company. The group is now working to achieve certification and delivery of ARJ21-700 aircraft by the end of this year, Jin said.With regard to China's C919 trunkliner program, Jin said COMAC has signed cooperation agreements with 17 international companies in the United States and Europe, and has actively explored collaboration with GECAS, British Airways and Ryanair."In the context that the world economy is on recovery from the financial crisis, the civil aviation industry is facing great challenge. We are willing to keep close contact with all relevant public administrations and forge friendly relations and cooperation with overseas suppliers to contribute to the development of world civil aviation industry," Jin said.For the French State Secretary for Transport Thierry Marianne, who also attended the opening ceremony, the Chinese aviation market has great potential in the years to come, and China is estimated to need 3,000 new planes."We have understood that China had decided to build its own aerospace industry. It is a legitimate choice," Marianne said.A demo mock-up of the full-scale forward fuselage of C919 will be displayed during the 49th Paris Air Show on June 20-26, which will be the first time that the 1:1 demo mock-up is to be showcased at an international stage outside China, Jin told Xinhua.During the air show, Comac is going to sign agreements with an international airline and an airborne-system supplier and carry out a series of activities concerning international cooperation and exchanges, according to the group.