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BEIJING, July 3 (Xinhuanet) -- The Atlantis mission to be launched by NASA on July 8 will not be an end to the space age, as some media suggest.Although it is the final mission of the space shuttle, it will open up "the next chapter" in the United States' space exploration, NASA's administrator Charles Bolden Jr said at the National Press Club in Washington on Friday."When I hear people say - or listen to media reports - that the final shuttle flight marks the end of US human space flight, I have to say . . . these folks must be living on another planet," he said."As a former astronaut and the current NASA administrator, I'm here to tell you that American leadership in space will continue for at least the next half-century because we have laid the foundation for success - and for NASA, failure is not an option," he said.NASA administrator Charles Bolden Jr drew a lot of media attention during his speech at the National Press Club in Washington DC.One of the foundations is the "unprecedented" research capabilities the International Space Station (ISS) now possesses, largely thanks to the space shuttle missions.Although some media imply that "the game will be up" once the ISS is out of orbit in 2020, he said the splendid research results and rich knowledge astronauts and scientists have accumulated through more than 1,200 experiments since 1998 have laid out "a stepping-stone to the rest of the solar system and the tip of what comes next".As NASA turns a new page, it will "focus on deep space exploration", while leaving US private companies to operate low Earth orbit transportation systems for tourism and business, he said.NASA will develop "a deep space crew vehicle and an evolvable heavy-lift rocket," he said. The moon, asteroids and Mars will be the next destinations for humans to live and work, he said."We will maintain and grow US leadership in space and derive all the benefits that flow from it. Tomorrow's space program is taking shape right now," he said.

SAN FRANCISCO, Sept. 6 (Xinhua)-- Yahoo on Tuesday fired Chief Executive Officer Carol Bartz and replaced her temporarily with the company's chief financial officer."On behalf of the entire board, I want to thank Carol for her service to Yahoo during a critical time of transition in the company's history, and against a very challenging macro-economic backdrop," said Yahoo Chairman Roy Bostock in a news release.The Yahoo Board of Directors appointed CFO Timothy Morse as interim CEO who will manage the company's day-to-day operations until a permanent chief executive is chosen.Carol Bartz, chief executive of Internet company Yahoo Inc, is shown in this undated publicity photo released to Reuters January 13, 2009. Before Yahoo's formal announcement, several news organizations and tech blogs posted an email reportedly from Bartz sent from her iPad to all employees of the company."To all, I am very sad to tell you that I've just been fired over the phone by Yahoo's Chairman of the Board. It has been my pleasure to work with all of you and I wish you only the best going forward."Bartz, 63, took over the Yahoo CEO role from co-founder Jerry Young in January 2009, when the company was struggling to stay competitive and profitable in a market dominated by Google. However, Yahoo never reached the heights she had foreseen.In the most recent quarterly earnings report in June, Yahoo reported net revenue of 1.1 billion U.S. dollars, down 5 percent from last year.Morse, 42, was hired as executive vice president and CFO at Yahoo in July 2009. "It is an honor to be selected for this role," he said in a statement Tuesday.Yahoo said it is starting a search for a new permanent CEO and plans to hire a "nationally recognized executive search firm" to assist in the effort.

WASHINGTON, Aug. 2 (Xinhua) -- The weakness of aging is associated with leaky calcium channels inside muscle cells and a drug already in Phase II clinical trials for the treatment of heart failure might plug those leaks, according to a report published Tuesday in the online edition of Cell Metabolism.Earlier studies by the research team led by Andrew Marks of Columbia University showed the same leaks underlie the weakness and fatigue that come with heart failure and Duchenne muscular dystrophy."It's interesting, normal people essentially acquire a form of muscular dystrophy with age," Marks said. "The basis for muscle weakness is the same." Extreme exercise like that done by marathon runners also springs the same sort of leaks, he added, but in that case damaged muscles return to normal after a few days of rest. A microscopic view shows smooth muscle cells derived from human embryonic stem cells showing the nuclei (blue) and proteins of the cytoskeleton (green) in this handout photo released to Reuters by the California Institute for Regenerative Medicine, March 9, 2009The leaks occur in a calcium release channel called ryanodine receptor 1 (RyR1) that is required for muscles to contract. Under conditions of stress, those channels are chemically modified and lose a stabilizing subunit known as calstabin1.Calcium inside of muscle cells is usually kept contained. When it is allowed to leak out into the cell that calcium itself is toxic, turning on an enzyme that chews up muscle cells. Once the leak starts, it's a vicious cycle. The calcium leak raises levels of damaging reactive oxygen species, which oxidize RyR1 and worsen the leak.The researchers made their discovery by studying the skeletal muscles of young and old mice. They also showed that 6-month-old mice carrying a mutation that made their RyR1 channels leaky showed the same muscular defects and weakness characteristic of older mice.When older mice were treated with a drug known as S107, the calcium leak in their muscles slowed and the animals voluntarily showed about a 50 percent increase in the amount of time spent wheel running. Now in clinical trials for patients with heart failure, the drug is known to work by restoring the connection between costabilin and RyR1.Despite considerable effort to understand and reverse age- related muscle wasting, there are no established treatments available. The new work suggests there may be hope in approaching the problem from a different angle."Most research has focused on making more muscle mass," Marks said. "What's different here is that we are focused not on muscle mass but on muscle function. More muscle doesn't help if it is not functional."

WASHINGTON, June 9 (Xinhua) -- Observations from NASA's Voyager spacecraft suggest the edge of our solar system may not be smooth, but filled with a turbulent sea of magnetic bubbles, the U.S. space agency said Thursday in a statement.While using a new computer model to analyze Voyager data, scientists found the sun's distant magnetic field is made up of bubbles approximately 100 million miles wide. The bubbles are created when magnetic field lines reorganize. The new model suggests the field lines are broken up into self-contained structures disconnected from the solar magnetic field. The findings are described Thursday in the Astrophysical Journal.Like Earth, our sun has a magnetic field with a north pole and a south pole. The field lines are stretched outward by the solar wind or a stream of charged particles emanating from the star that interacts with material expelled from others in our corner of the Milky Way galaxy.The Voyager spacecraft, more than nine billion miles away from Earth, are traveling in a boundary region. In that area, the solar wind and magnetic field are affected by material expelled from other stars in our corner of the Milky Way galaxy."The sun's magnetic field extends all the way to the edge of the solar system," said astronomer Merav Opher of Boston University. "Because the sun spins, its magnetic field becomes twisted and wrinkled, a bit like a ballerina's skirt. Far, far away from the sun, where the Voyagers are, the folds of the skirt bunch up."Understanding the structure of the sun's magnetic field will allow scientists to explain how galactic cosmic rays enter our solar system and help define how the star interacts with the rest of the galaxy.So far, much of the evidence for the existence of the bubbles originates from an instrument aboard the spacecraft that measures energetic particles. Investigators are studying more information and hoping to find signatures of the bubbles in the Voyager magnetic field data."We are still trying to wrap our minds around the implications of the findings," said University of Maryland physicist Jim Drake, one of Opher's colleagues.Launched in 1977, the Voyager twin spacecraft have been on a 33- year journey. They are en route to reach the edge of interstellar space. NASA's Jet Propulsion Laboratory built the spacecraft and continues to operate them.

WASHINGTON, July 12 (Xinhua) -- Two U.S. astronauts stepped out the International Space Station on Tuesday to retrieve a failed ammonia pump, which is the last spacewalk of the shuttle era, NASA announced.Space station astronauts Mike Fossum and Ron Garan completed the six-hour, 31-minute spacewalk at 3:53 p.m. EDT (1953 GMT). The duo retrieved a pump module from an external stowage platform on station and store it in shuttle Atlantis' cargo bay for return to Earth.The pump module failed in 2010, shutting down half of the space station's cooling system. Engineers will evaluate the module to determine the cause of the failure and plan to refurbish it for use as a spare.The astronauts also attached a Robotic Refueling Module experiment to the space station, which aims to test technologies for repairing and refueling satellites in space.It was the 249th spacewalk by U.S. astronauts and the 160th spacewalk in support of space station assembly and maintenance, totaling 1009 hours, nine minutes.Atlantis lifted off on Friday morning from Kennedy Space Center in Florida, on the 135th and final flight in NASA's shuttle program. Its return to the earth later this month will mark the end of the 30-year shuttle program.