journal Nature fifty years ago this week. To celebrate, we looks back the key scientific achievements of the

Standard English The DNA RevolutionFifty Years after Watson and Crick, the New Questions in GeneticsApril 2003 -- Fifty years ago this week, a one-page report published in the British science journal Nature revolutionized science. In it, James Watson and Francis Crick described the three-dimensional structure of DNA.Knowing DNA's structure immediately solved one of biology's greatest mysteries -- how genetic instructions are passed on from one generation to the next. And it opened the door to what has become the hottest area of medical research -- genetics.Human Genome Project director Francis Collins says, even 50 years later, it's impossible to overstate the importance of knowing the structure of DNA:"It is so intertwined in every bit of what we do experimentally, in terms of perceiving our own position in the scheme of life on this planet. It has become one of those givens that is so central to your thinking that you stop thinking about it, but if somebody took it away from you, your whole intellectual foundation would collapse, and it would be unimaginable what we would be doing now if we didn't know about the double helix."To mark the 50th anniversary of Watson and Crick's paper, NPR presents a series of reports on how the discovery has changed research, and what the new biomedical frontiers are.China Marks 34th Earth Day with Focus on Resources Protection Special EnglishOverseas Chinese Return Home For The Good LifeWhen Michael Lee left China in 1986 to pursue an education in the United States, he was swapping a land of poverty for a land of plenty. Today, he is far from sure that's still the case. Along with an increasing number of other well educated Chinese living in America, Lee can't wait to return home as China, with its turbo-charged economic growth, offers better job prospects than the United States. Even the outbreak of the deadly SARS virus in Hong Kong and the mainland does not appear to be a deterrent.Lee said he quit his job to earn an MBA at MIT to help him get on the corporate fast-track back home. He envies his former classmates from a top university in China, as they now hold top corporate positions.To be sure, there are still more Chinese coming into the United States than are returning, but a recent survey found that 80 percent of Chinese students now studying abroad said they would like to go back.Overall, China still suffers more of a brain drain than a brain gain: In the last 25 years, only about a quarter of the students have returned home after graduation, according to the Chinese Ministry of Education.But the number of "sea turtles," the nickname for returnees to China, is growing rapidly. In 2002, 180,000 Chinese students went back, up 47 percent from 2001.Lee and others like him have little trouble finding jobs in China given their U.S.-acquired qualifications, fluency in English and hands-on business experience, say recruiters for U.S. companies.They are much in demand, and the need is immediate, China attracted more foreign direct investment than any other country last year, and an increasing number of U.S. companies, after many years of losing money there, are now turning a profit.Salary levels in China have soared in recent years, with some top lawyers earning as much as 1 million US dollars a year and some engineers in the range of 100 thousand dollars. In a country where the average income is still less than 1/20th of that in the United States, returnees feel that even a reduced salary would allow them a better life style because the cost of living is lower.Tuesday is the 34th World Earth day, which China has given the theme of "treat the earth better and better protect resources."An official with the Ministry of Land and Resources says at a ceremony in Beijing that China is strengthening the protection of resources through the strict implementation of relevant laws.China has drawn up several laws and regulations over the past few years concerning land resource management and coal protection. Meanwhile, investigation work has also been intensified on land resources and new resource explorations.China's per-capita farmland area makes up less than 50 percent of the world's average, and with its huge population and rapid economic development, the country is also suffering a shortage of mining resources