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BEIJING, Sept. 6 (Xinhuanet) -- Scientists from Tufts University of the U.S. have created the world's smallest electrical motor in a single molecule.The finding was published in the journal Nature Nanotechnology on Monday.In the research, scientist successfully made a single molecule accept an electrical charge and rotate as fast as 120 revolutions per second."This is the first time that electrically-driven molecular motors have been demonstrated, despite a few theoretical proposals," said Charles H. Sykes, professor of chemistry at Tufts who led the team.The single molecule electric motor could lead to new types of electrical circuitry, giving hope for scientists to apply it in medicine and engineering, he said."The next thing to do is to couple it to other molecules, lining them up next to one another so they're like miniature cog-wheels, and then watch the rotation propagation down the chain," said Sykes.

SAN FRANCISCO, Aug. 15 (Xinhua) -- Facebook and Yahoo on Monday started to test "six degrees of separation," an iconic social experiment in the 1960s that showed everyone is on average approximately six steps away from any other person on earth.The current Facebook-Yahoo "small world" experiment, based on more than 750 million active Facebook users, is expected to determine the social path length between two strangers.Anyone with a Facebook account can participate by going to smallworld.sandbox.yahoo.com and will be assigned a "target person. " The participant will be asked to select one of his or her Facebook friends, whom will be forwarded a message and then pass the message from friend to friend so that the participant will get a message to the "target person" in as few steps as possible.The study is intended as academic social research and will be published in peer-reviews scientific journal, Duncan Watts, Yahoo' s principal research scientist who is leading the experiment, told San Jose Mercury News.In the 1960s, American social psychologist Stanley Milgram and other researchers conducted several experiments to examine the average path length for social networks of people in the United States, suggesting that human society is a small world type network by around 5.5 people steps or about six people on average.It is now currently accepted that there were potential flaws in the so-called "small world experiment" because the conclusions were based on relatively small number of research samples.

SAN FRANCISCO, Sept. 22 (Xinhua) -- Facebook on Thursday introduced Timeline, a new profile design featuring milestones of one's life on a single page.At Facebook's f8 developer conference, Chief Executive Officer Mark Zuckerberg promoted the new feature, a blog-like presentation that let users scrolls vertically through the big moments of one's life."It's how you can tell the whole story of your life in a single page," said Zuckerberg, showing his Timeline which started from a baby photo.Zuckerberg assured users that they have complete control over their Timeline, saying that they can decide what content will appear and who can see it. The new feature will be available in a few weeks.Half a billion people are using Facebook in the world everyday, according to Zuckerberg.

HAVANA, Aug. 15 (Xinhua) -- Cuba's Ministry of Public Health launched an intensive sanitation campaign Monday against the Aedes Aegypti mosquito, which can spread dengue fever.The operation, which is running through Sept. 15, will cover the most vulnerable cities in the country, including the capital Havana and the eastern city Guantanamo.Deputy Health Minister Luis Estruch stressed the importance of the prevention campaign and urged all families to check their houses for mosquitoes each week.Maria Guadalupe Guzman, director of the Pan-American and World Health Organization Cooperation Center for the Study of Dengue and Its Vector at the Pedro Kouri Institute of Tropical Medicine, said the epidemiological situation in the country is stable. However, she warned that an epidemic outbreak is still possible in the island state, given the high temperatures and heavy rains in the eastern areas, and drought in the west.Cuba, along with Chile and Uruguay, are the only Latin American countries where dengue is not endemic.In 1981, the country suffered its worst dengue outbreak in history, which left 158 dead.

WASHINGTON, July 7 (Xinhua) -- Space shuttle Atlantis will soar into the sky Friday on NASA's 135th and final flight. Its scheduled return to Earth later this month will mark the end of NASA's 30-year space program.Since its onset with the launch of space shuttle Columbia, the program has been seen as a cheap, safe and reliable way for space exploration.Despite its great contributions to U.S. manned space flight, it has also left some grave and tragic lessons, making its termination inevitable.HIKING COSTSLaunched in 1972 by then President Richard Nixon, the shuttle program aimed to provide a new system of affordable space travel and proved to be NASA's most enduring project in its 50 years of existence.In 1981, shuttle Columbia made its first shuttle flight for two days. It was the ultimate hybrid and the first reusable spacecraft.Launched like a rocket and gliding back to Earth like an airplane, space shuttles not only can act as a space taxi to carry astronauts, but have the muscle of a long-distance trucker to haul heavy machinery.The spaceship boasts more than 3,500 subsystems and 2.5 million parts and is nine times faster than a speeding bullet as it climbs heavenward. That versatility, however, has translated into higher costs.NASA originally estimated the program would cost about 90 billion U.S. dollars. However, its actual cost stands at about 200 billion dollars, compared with the 151 billion dollars spent on Apollo which took Americans to the moon in 1969.In an article in Technology Review, John Logsdon, former head of the Space Policy Institute at George Washington University, drew a direct connection between the ravenous shuttle budget and the lack of other large advances in manned space flight."By operating the system for 30 years, with its high costs and high risk, rather than replacing it with a less expensive, less risky second-generation system, NASA compounded the original mistake of developing the most ambitious version of the vehicle," he wrote."The shuttle's cost has been an obstacle to NASA starting other major projects," he added.HIGH RISKIn terms of safety, the shuttles have never been as reliable as their designers had envisioned.On average, one out of every 67 flights ended up with fatal accidents. Based on the rate of deaths per million miles traveled, the space shuttle is 138 times riskier than a passenger jet.Seven astronauts onboard died when Challenger exploded about a minute after launch in 1986. Nearly two decades after the tragic blast, a new catastrophe descended when the shuttle Columbia disintegrated moments before landing in 2003, killing another seven spacemen.Again, the shuttle program was shelved for more than two years as NASA stepped up efforts to make it safer. But experts say the fundamental problem related to shuttles' safety cannot be solved due to their "birth defects.""It is in the nation's interest to replace the Shuttle as soon as possible," concluded the panel that investigated the 2003 Columbia accident.