宜宾出名隆胸医生(宜宾玻尿酸的品牌) (今日更新中)

CANBERRA, Aug. 17 (Xinhua) -- Australian scientist on Wednesday said his international research team has discovered the trick on how butterfly learn to change its wing pattern to avoid being eaten by birds.The Amazonian butterfly, Heliconius numata, has learnt to carry out a single genetic switch to alter its wing pattern so it appears to be another bad-tasting butterfly that birds will avoid.Dr. Siu Fai (Ronald) Lee from the Department of Genetics and Bio21 Institute at Australia's University of Melbourne was part of the international research team, which was led by scientists at Centre National de la Recherche Scientifique (CNRS) and the University of Exeter in United Kingdom.Dr. Lee said the historical mystery had puzzled researchers for decades."Charles Darwin was puzzled by how butterflies evolved such similar patterns of warning coloration," Dr. Siu Fai (Ronald) Lee from the Department of Genetics and Bio21 Institute at the University of Melbourne told Western Australia Today."We have now solved this mystery, identifying the region of chromosome responsible for changing wing pattern."He said the research team identified a genetic switch known as a supergene, which allowed the butterfly to morph into several different forms, allowing one species to mimic another."It is amazing that by changing just one small region of the chromosomes, the butterfly is able to fool its predators by mimicking a range of different butterflies that taste bad," he said."The butterflies rearrange this supergene DNA like a small pack of cards, and the result is new wing patterns. It means that butterflies look completely different but have the same DNA."There are other butterflies doing similar tricks, but this is the most elegant one."I was just fascinated by how elegant they were."He said the discovery proves that small chromosomal changes can preserve successful gene combinations, and thus help a species to adapt.The findings of the study are published on August 14 in the international journal Nature.

coastline in the U.S. State of California sampled by the state water board harbored fish with mercury in such high concentrations that they shouldn't be eaten by young women and children, a newly released survey has found.Fourteen percent of locations had similarly elevated levels of PCBs, according to the survey published by The Los Angeles Times on Sunday.The most elevated concentrations of mercury and PCBs were found in San Francisco Bay and San Diego Bay, said the survey funded by the state water board.The findings, part of a two-year inquiry that is the largest statewide survey of contaminants in sport fish along the California coast, examined more than 2,000 fish from three dozen species gathered in 2009 from waters near Los Angeles, San Francisco and San Diego, the paper said.The survey highlights the health problem of lingering mercury, a poisonous metal that is found in fish globally, and of PCBs, toxic chemicals the United States banned in the 1970s, the report said.Both substances continue to pose a risk to people who eat fish caught along the California coast because they can lead to nervous system damage and developmental problems in children and can cause cancer, liver damage and reproductive harm, the report quoted researchers as saying."Unfortunately, we're not seeing many areas that are totally clean," said Jay Davis, a senior scientist for the San Francisco Estuary Institute and lead author of the study. But a catalog of where and in what fish the substances abound should help anglers make better choices, Davis said. "With good information, people can reduce their exposure significantly."Sharks had some of the highest levels of mercury because of their unusual tendency to accumulate contaminants in their flesh, while chub mackerel had the lowest levels of contamination, according to the survey.The survey results were used in part to help craft new fish consumption guidelines issued earlier this week for anglers in San Francisco Bay, the first update there by state health officials in 17 years. The advisory identifies shiner perch and other surf perches as unsafe to eat in any quantity and warns young women and children not to eat white sturgeon, striped bass and sharks caught in the bay, The Times said.The buildup of metals and other chemicals in fish is such a problem along the Southern California coast that health officials two years ago expanded the number of fish species on the "do not eat" list from one to five because of high levels of PCBs, mercury and the banned pesticide DDT, the report noted.

BEIJING, Sept. 20 (Xinhuanet)-- Google's executive chairman Eric Schmidt is to face a Senate hearing on whether the company is abusing its dominance in Internet search, according to media reports on Tuesday.At the Wednesday's hearing before the Senate Judiciary Committee's antitrust panel, Schmidt will argue that critics are wrong to say Google gives preference to its own products, instead, Google is just trying to deliver the best-cultivated search results for users. The issue of search ranking is a touchy subject with Google, which says its algorithm is devised to give users the most useful result so they will come back.Another focal point of the hearing, which Schmidt concerned most is "scrapers", those who game its search algorithm, for example, taking commonly searched words, combine them into a nonsensical block of text and throw it up on the Web to grab eyeballs and advertising dollars.Google believes that, if scrapers succeed too often, consumers will lose confidence in search and turn to other resources, thus posing an existential threat to the company.Regulators in the U.S. and abroad have been looking into various aspects of Google's business practices since the company's 2007 purchase of ad firm DoubleClick. At the moment, European regulators are conducting an antitrust inquiry into Google's search business while the Federal Trade Commission is doing likewise. Google relies overwhelmingly on its core product, Internet search, and dominates the market for that product. It handles around two-thirds of U.S. Internet searches and more than 80 percent in many European countries, according to comScore Inc.

Beijing, Sept. 13 (Xinhuanet) -- A fear of taking antidepressants often results in people's reluctance of going to see the doctor when they are suffering from depression, a study find.The finding was published Monday in the U.S. journal Annals of Family Medicine.The researchers from the University of California investigated 1,054 adults on why they wouldn't tell the doctors about their depression symptoms, as well as any possible mental disorder.Among the participants, 43 percent admitted that they had been reluctant to tell the doctor about their depression symptoms.Their top concern was the possibility of being prescribed an antidepressant -- a worry voiced by 23 percent of the whole study group.Another 16 percent thought dealing with "emotional issues" is not the doctor's job. And a similar percentage worried that the diagnosis of depression may leave a negative record on their medical records.The study would be helpful for looking into the reasons that patients harbor the attitudes that they do, said Dr. Hellerstein of the New York State Psychiatric Institute and Columbia University Medical Center in New York.

BEIJING, Sept. 5 (Xinhua) -- China and the World Bank are jointly researching ways to help rebalance the world's second largest economy and move toward a path of sustainable growth under the current challenging global economic situation, said World Bank Group President Robert B. Zoellick on Monday.A report, jointly being prepared by the World Bank, China's Ministry of Finance, and the Development Research Center of the State Council, will be released later this year to support China in identifying the many challenges and policy choices it will face in the next two decades, as the country seeks to avoid the so-called "middle-income trap," a stage of economic development that has slowed progress in many countries, Zoellick said.Regarding this autumn as "a sensitive time facing the world's major economies," Zoellick said many countries, including the United States, the European Union and Japan, were facing the similar fundamental challenge of restructuring for sustainable economic growth."Perhaps the challenge is more difficult for China as the country has already made remarkable progress, and thus it's not easy to persuade people to make a change," he said.Commenting in Beijing on a weekend workshop with senior Chinese officials and outside experts, Zoellick said there was agreement that China will have to rebalance its economy, improve the environment, reduce inequality and advance the quality of life for its people while at the same time maintaining rapid growth."In the near term, inflation is China's priority, as Premier Wen Jiabao mentioned," Zoellick said, adding that the Chinese government was moving in the right direction, though it was too early to have the problem solved.In next 10 years, however, Zoellick said he could not imagine China continuing to rely on exports for growth, especially when developed economies have had difficulties recovering.By shifting away from an over-dependence on export-led growth to a greater reliance on domestic demand and investment, China could benefit not only itself but the world economy, he said.As China's 12th Five-Year Plan has pointed the way forward with what needs to be done, Zoellick said the ongoing research will try to help with the "how."He said the report will cover issues such as how China can complete its transition to a market economy; how to promote open innovation; how to advance green development; how to deliver equality of opportunity and social security to citizens; how to strengthen the fiscal system, and how China can become a responsible stakeholder in the international system.During his stay in China, Zoellick also visited the country's wasteland-turned-grain-producing-base in the northeast, including a farm, a rice mill, an agricultural research center and a modern agricultural machinery park, and learned about how this land transformation had affected local people's lives.As the world population is expected to hit 9 billion by 2050, Zoellick said the World Bank has been urging G-20 countries to prioritize food issues."China feeds 20 percent of the world's population with less than 10 percent of the world's agricultural land and less than six percent of its water, so China could make a significant contribution to global food security," Zoellick said.

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