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BEIJING, Sept. 4 (Xinhua) -- Officials and delegations from China and African countries have gathered at a seminar being held in Beijing to discuss rural development and economic growth.The seven-day seminar kicked off on Sunday, attracting representatives from China and 11 African countries to exchange views and experiences related to the seminar's theme of "agriculture and rural development."Justin Lin Yifu, chief economist and senior vice president of the World Bank, said at the seminar's opening ceremony that African countries should take cues from China's experience in creating a series of policies to bolster agricultural and rural development, as these policies have also facilitated the country's economic growth.Hu Jinglin, assistant to China's Minister of Finance, said improved agricultural cooperation between China and Africa will help enhance global grain security.China has worked on 142 cooperative agricultural projects with 14 African countries to date. In addition, it has sent 104 agricultural experts to 33 African countries to train more than 4,200 local agricultural technicians.

MOSCOW, Aug. 30 (Xinhua) -- Russia's space agency said Tuesday that a Proton-M rocket launch failed earlier this month because of a malfunction in the upper stage.The conclusion was reached by an independent investigation commission following a series of checks, Roscosmos said in a report that was posted on its website."The commission reported that the time span reserved for the gyrostabilized platform's turn was miscalculated and narrowed, which caused the Briz-M upper stage's disorientation and the satellite's journey to a wrong orbit," the agency said.Other systems in the upper stage performed well, the agency said, adding it has lifted a ban on launches of the Proton-M carrier rockets equipped with the Briz-M upper stage.Local media reported the Briz-M, manufactured by the Khrunichev State Research and Production Space Center, has had five failures over its 12-year history of operation.On Aug. 18, a Proton-M carrier rocket failed to deliver a communications satellite into orbit. After the failure, Russia suspended launches of Proton-M rockets pending the outcome of an investigation into the failure.

Beijing, Sept. 6 (Xinhua) -- A sperm donation scandal disclosed recently has aroused growing concern in the United States.According to the New York Times' report, Ryan Kramer, the son of a donor, found that he has more than 150 half-siblings - they are all the children of the same donor."It's wild when we see them all together - they all look alike," said Cynthia Daily, mother of Kramer.As more women choose to have children on their own, the demand for sperm donors has surged.Some sperm banks are earning huge profits by allowing too many mothers to receive sperms from the same popular donors, according to the report.And this trend will lead to risks: rare genetic diseases could be spread more widely, and the children of the same donor could meet and, unbeknownst to them, commit incest, medical experts warned.Parents and donors are calling for a tighter regulation so that donor children can know more about their donors, and the number of kids from each donor can be limited.

WASHINGTON, July 18 (Xinhua) -- Exposure to secondhand smoke ( SHS) is associated with increased risk of hearing loss among adolescents, according to a report in the July issue of Archives of Otolaryngology -- Head and Neck Surgery.Among U.S. children, approximately 60 percent are exposed to SHS, according to background information in the article. Studies have associated exposure to secondhand smoke prenatally or during childhood with various health conditions, from low birth weight and respiratory infections to behavioral problems and otitis media. Children exposed to SHS are more likely to develop recurrent otitis media, the authors note. "Secondhand smoke may also have the potential to have an impact on auditory development, leading to sensorineural hearing loss (SNHL)," they add.Anil Lalwani and colleagues from New York University Langone Medical Center examined the risk factors for SNHL, including SHS, among adolescents, stratified by demographic groups. They included 1,533 individuals from 12 years to 19 years of age who participated in the National Health and Nutrition Examination Survey from 2005 to 2006.Participants were interviewed about their health status and family medical history, exposure to SHS, and self-recognition of hearing impairment. In addition, they underwent a physical examination, including blood testing for cotinine (a by-product of nicotine exposure), and hearing tests.Compared with teens who had no SHS exposure, those who were exposed to secondhand smoke exhibited higher rates of low- and high-frequency hearing loss. The rate of hearing loss appeared to be cumulative, increasing with the level of cotinine detected by blood tests. The results also demonstrated that more than 80 percent of participants with hearing loss did not realize they had impairment.As hearing loss early in life can cause problems with development and functioning, the authors suggest that these results have "significant implications for public health in the United States."They note that most adolescents do not receive screening for hearing loss in the absence of risk factors.If further studies replicate these results, they state, SHS could be considered one such risk factor.

BEIJING, Sept. 23 (Xinhua) -- A defunct U.S. satellite is expected to crash down to Earth Friday, with nobody knowing where or when exactly it will hit. This was avoidable, a Chinese expert said Thursday.Pang Zhihao, a researcher from the Chinese Research Institute of Space Technology, told Xinhua that the crash could have been avoided had the satellite been put into a higher orbit, or manipulated to drop in the South Pacific when it had abundant fuel. It would pose no threat to Earth if these measures had been taken.NASA's tumbling, 5,900 kg Upper Atmosphere Research Satellite, or UARS, is the first of such man-made space vehicles that have been launched into outer space according to the agency's Mission to Planet Earth. The mission was launched in the 1990s.The mission is designed to provide data for better understanding Earth's upper atmosphere and the effects of natural and human interactions on the atmosphere.The satellite was deactivated in 2005 as it ran out of fuel and was left orbiting Earth like a big piece of space junk.There are other cases of defunct satellites. The European Space Agency said earlier its observation satellite ERS-2 has run out of fuel and is deorbiting. It would therefore also crash sooner or later.Pang said all countries which are operating space vehicles should take care of their own spacecrafts so that they won't pose any danger.The expert also said that the public need not worry too much.Pang said most spacecrafts will be incinerated upon re-entering Earth's atmosphere, and the debris will mostly likely fall into the ocean or hit an uninhabited area. In addition, a debris tracker is able to give a comparatively accurate prediction where the craft will fall about two hours before it hits Earth, giving residents, if there are any, time to evacuate.He added that there are several ways to minimize the threat of decommissioned spacecrafts, like putting them into higher orbits and crashing them into designated waters.Scientific progress would possibly bring about more ways of dealing with tumbling satellites. Scientists have already been trying to build spacecrafts with degradable materials so that they can self-destruct when re-entering Earth's atmosphere.