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BEIJING, Aug. 22 (Xinhuanet) -- Researchers have discovered how a human egg captures an incoming sperm for fertilization, paving the way to help couples suffering from infertility, according to media reports on Monday.An international team of researchers found that a sugar chain known as the sialyl-lewis-x sequence (SLeX) makes the outer coat of the egg “sticky,” which has proven to be helpful in binding the egg and the sperm.As a result, this observation has filled in a huge gap in the understanding of fertility and provides hope for ultimately helping couples who currently cannot conceive.Scientists and doctors know that a sperm identifies an egg when proteins on the head of the sperm match and bind to a series of specific sugars in the egg’s outer coating. With a successful match of proteins, the outside surfaces of the sperm and egg then bind together before merging, which is then followed by delivery of sperm’s DNA into egg.To identify this molecules, the researchers used ultra-sensitive mass-spectrometric imaging technology to observe and identify which molecules are most likely to be key in the binding process.They experimented with a range of synthesised sugars in the laboratory and found that it is SLeX that specifically binds sperm to an egg.According to the World Health Organisation, infertility affects about 15 percent of reproductive-aged couples around the world and almost one in every seven couples in Britain has problems conceiving a child for various reasons.

YUEYANG, Hunan, June 2 (Xinhua) -- The population of finless porpoises, an endangered species of freshwater dolphin that lives in China's Yangtze River, may decrease by over 80 percent over the next 30 years, experts said on Thursday after conducting a field survey along the river.The rare species will edge closer to extinction if no action is taken, said Wang Ding, a dolphin expert from the Hydrobiology Institute of the Chinese Academy of Sciences.Wang's team conducted a survey on Poyang Lake, Dongting Lake and other locations along the Yangtze from Sunday to Wednesday this week.The dolphin population currently stands at 1,000, even lower than that of the giant panda, Wang said.The dolphin population is decreasing by a rate of 6.4 percent annually, Wang said."The next ten years will be a critical period for the conservation of this species," Wang said.A long-lasting drought in central China has lowered water levels in many of the region's lakes and rivers, doing great harm to the dolphins' habitat and leading to a decrease in population, Wang said.Mei Zhigang, a member of Wang's survey team, said that human activity has also contributed to the dropping population.Mei said that large numbers of shipping vessels on the Yangtze have impeded the dolphins' migration path, causing them to reproduce less frequently.

BEIJING, Aug. 24 (Xinhuanet) -- Facebook said it is overhauling its privacy settings to give members easier, more precise control over who sees posts, photos and other content over the vast social network.Starting Thursday, Facebook is rolling out new privacy tools that are placed with each piece of content, replacing options that are now buried in overall account settings.Privacy has been a consistently sticky problem for the Palo Alto firm, which has felt the heat from privacy advocates and government regulators. And recently, Facebook faced stiffer competition from Google's new Google+ social network, which was hailed for including a "circles" feature with easy-to-use privacy settings.Instead of vague labels such as "everyone," which have been mistaken for a Facebook member's social network instead of anyone on the Internet, the new system will include more precise words such as "public.""You have told us that 'who can see this?' could be clearer across Facebook, so we have made changes to make this more visual and straightforward," Chris Cox, Facebook's vice president of product, said in blog post."The main change is moving most of your controls from a settings page to being inline, right next to the posts, photos and tags they affect. Plus there are several other updates here that will make it easier to understand who can see your stuff (or your friends') in any context," Cox said.While privacy advocates reserved judgment until the new settings are actually released, they were optimistic the changes will benefit consumers."These changes do make me feel very confident in the direction that Facebook is going and the way they are thinking about privacy," said Erica Newland, policy analyst for the Center for Democracy & Technology in Washington, D.C.

LOS ANGELES, June 8 (Xinhua) -- NASA's Mars Exploration Rover Opportunity is heading toward "Spirit Point" on the rim of a large crater, a long-term destination that the rover has been trying to reach for nearly three years, the Jet Propulsion Laboratory (JPL) announced on Wednesday.Opportunity has moved toward the crater, Endeavour, since climbing out of Victoria crater in August 2008.Having driven 11 miles (18 kilometers), the rover has about two miles (about three kilometers) to go before reaching the rim of Endeavour, said JPL in Pasadena, Los Angeles.Rover team members last week selected "Spirit Point" as the informal name for the site on the rim where Opportunity will arrive at Endeavour crater. The choice commemorates Opportunity's rover twin, Spirit, which has ended communication and finished its mission."Spirit achieved far more than we ever could have hoped when we designed her," said Steve Squyres of Cornell University, Ithaca, New York, principal investigator for the rovers. "This name will be a reminder that we need to keep pushing as hard as we can to make new discoveries with Opportunity. The exploration of Spirit Point is the next major goal for us to strive for."Endeavour offers the setting for plenty of productive work by Opportunity. The crater is 14 miles (22 kilometers) in diameter -- more than 20 times wider than Victoria crater, which Opportunity examined for two years. Orbital observations indicate that the ridges along its western rim expose rock outcrops older than any Opportunity has seen so far. Spirit Point is at the southern tip of one of those ridges, "Cape York," on the western side of Endeavour.Opportunity and Spirit completed their three-month prime missions on Mars in April 2004. Both rovers continued for years of bonus, extended missions. Both have made important discoveries about wet environments on ancient Mars that may have been favorable for supporting microbial life.NASA's JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover Project for the NASA Science Mission Directorate, Washington.

BEIJING, Aug. 5 (Xinhuanet) -- A study conducted by Israeli researchers at the Albert Einstein College of Medicine in New York shows that genes, rather than good eating and lifestyle habits, determine longevity, according to media reports Friday. "This study suggests that centenarians may possess additional longevity genes that help to buffer them against the harmful effects of an unhealthy lifestyle," said senior author Nir Barzilai, director of the Institute for Aging Research at Yeshiva University's Albert Einstein College of Medicine.The study involves 477 Ashkenazi Jews between the ages of 95 and 122, of whom 75 percent are women. According to the study, Ashkenazi Jews are chosen as subjects because they are more "genetically uniform than other populations, making it easier to spot gene differences that are present."The study also found that the long-lived Ashkenazi Jews drank slightly more and exercised less than their average counterparts. But Barzilai also warned: “Although this study demonstrates that centenarians can be obese, smoke and avoid exercise, those lifestyle habits are not good choices for most of us who do not have a family history of longevity.""We should watch our weight, avoid smoking and be sure to exercise, since these activities have been shown to have great health benefits for the general population, including a longer lifespan," He added.

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