天津看白癜风口碑好的医院(广东治白癜风哪较好) (今日更新中)

CANBERRA, Sept. 23 (Xinhua) -- A genetic study on Friday found Aboriginal Australians are descended from the first people to leave Africa up to 75,000 years ago.Researchers from the University of Western Australia, Murdoch University and an international team analyzed genetic material of a 100-year-old West Australian Aboriginal man's hair, and found he was directly descended from a migration out of Africa into Asia.The study revealed that Australian Aboriginal ancestors split from the first modern human populations to leave Africa, between 64,000 and 75,000 years ago, at least 24,000 years before other human migrations.According to Dr. Joe Dortch, an archaeologist at the University of Western Australia, the discovery rewrites the history of the human species by confirming humans moved out of Africa in waves of migrations rather than in one single out-of-Africa diaspora.It also rewrites the story about how Aborigines arrived in Australia some 50,000 years ago."So far there are no [archaeological] sites that are over 50, 000 years old so it puts a time limit on that and focuses our future efforts," he said in a statement released on Friday.Dr. Dortch believes the finding will foster a sense of pride in modern Australian Aborigines."No-one else in the world can say 'I am descended from people who have been here 75,000 years'."Associate Professor Darren Curnoe, leader of the Human Evolutionary Biology Lab in the School of Biological, Earth & Environmental Sciences at the University of New South Wales, said the study powerfully confirms that Aboriginal Australians are one of the oldest living populations in the world, certainly the oldest outside of Africa."Australians are truly one of the world's great human populations and a very ancient one at that, with deep connections to the Australian continent and broader Asian region. About this now there can be no dispute," he told Xinhua in an email note.Meanwhile, Professor Alan Cooper, Director of the Australian Centre for Ancient DNA (ACAD) at the University of Adelaide, said while this is a major step forward, the key unresolved question remains the unique story of Aboriginal history within Australia, such as what has happened in those 50,000 years of life in the harsh Australian environment."Unfortunately, the information from a single individual tells us very little about this fascinating, and critically important part of human history. Aborigines are one of the oldest continuous human populations outside Africa, as they note in the paper, and due to the geographic isolation and limited archaeological records remain one of the most mysterious chapters in human history," he told Xinhua on Friday.The study is published on Friday in the journal Science.Indigenous Australians are the original inhabitants of the Australian continent and nearby islands. They together make up more than 2.5 percent of Australia's population.

ISLAMABAD, Sept. 11 (Xinhua) -- Chinese ambassador to Pakistan declared on Sunday that the Chinese government will provide an emergency humanitarian aid worth 30 million RMB (4.7 million U.S. dollars) to Pakistan to help its relief efforts.In light of the immense damages caused by the floods in some parts of Pakistan, Chinese Ambassador to Pakistan Liu Jian called on Pakistani Foreign Minister Hina Rabbani Khar on Sunday to express sympathy and solidarity of the Chinese people toward Pakistani people and declared that the Chinese government will provide the emergency humanitarian aid.Diplomats and staff of the Chinese Embassy in Islamabad have recently voluntarily donated 600,000 rupee (about 6860 U.S. dollars) to the people who hit by the floods. The Chinese ambassador handed over the donation to Pakistani side on Sept. 8.On Sept. 9, Chinese Foreign Minister Yang Jiechi sent a message to his Pakistani counterpart H.E. Hina Rabbani Khar, expressing his profound condolence to the victims and sincere sympathy to the affected people of the floods.The Chinese foreign minister said that China, as Pakistan's close friend, feels as much pain as Pakistan does and is ready to provide help to the best of its ability, in line with Pakistan's needs. He is convinced that the Pakistani people will definitely prevail over the natural disaster and rebuild their homes at an early date.

SAN FRANCISCO, July 28 (Xinhua) -- Amazon announced Thursday that it had reached an agreement with NBC Universal to allow its members to view certain movies from Universal Pictures on-line through its movie streaming service.According to the on-line retail giant, Oscar-winning movies such as "Eternal Sunshine of the Spotless Mind," "Gosford Park" and "Elizabeth" as well as other favorites like "Notting Hill" and "Billy Elliot" are part of the pact.The movies will be available to Amazon Prime members through its streaming service Prime Instant Video. Amazon Prime is a membership program that gives subscribers discounts on shipping for a 79 U.S. dollar annual fee.In February, Amazon said it would offer Prime customers unlimited access to an on-line video library. Last Wednesday, Amazon announced an accord with CBS that expanded the video library to more than 8,000 movies and TV shows. It said Thursday that the NBC deal will bring the number to more than 9,000.With the CBS, NBC Universal deals, Amazon steps up its rivalry against other movie streaming services, especially Netflix, a popular on-line and mail-order movie rental company which just boosted prices by 60 percent for some subscribers. Analysts said Amazon is trying to make the pitch to those customers who are disappointed with Netflix.In a second-quarter earnings letter to investors distributed on Monday, Netflix CEO Reed Hastings said Netflix had more than 24.6 million subscribers in the U.S. at the end of June and vastly more streaming content than its competitors."We haven't detected an impact on our business from Amazon Prime," he noted.

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.

WASHINGTON, Sept. 13 (Xinhua) -- The U.S. Department of Agriculture (USDA) announced Tuesday it will begin testing next year for six more kinds of E.coli bacteria in raw ground beef and tenderized steaks in order to protect the safety of the American food supply.The U.S. currently tests for one strain of E.coli O157:H7 in beef. According to the USDA, from March 5 next year, if the E. coli serogroups O26, O103, O45, O111, O121 and O145 are found in raw ground beef or its precursors, those products will be prohibited from entering commerce.Like E.coli O157:H7, these serogroups can cause severe illness and even death, and young children and the elderly are at highest risk."The Obama Administration is committed to protecting our food supply and preventing illnesses before they happen," said Agriculture Secretary Tom Vilsack in a statement. "Today's announcement does exactly that by targeting and eliminating contaminated products from the market.""Too often, we are caught reacting to a problem instead of preventing it. This new policy will help stop problems before they start," he said.About one in six Americans becomes sick from a food borne illnesses each year, an epidemic that kills about 3,000 annually and hospitalizes 128,000, according to the U.S. Centers for Disease Control and Prevention.

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