山西便血常见的原因(太原肛门阻塞) (今日更新中)

WASHINGTON, Dec. 5 (Xinhua) -- NASA's Kepler mission has confirmed its first planet in the "habitable zone," a region where liquid water could exist on a planet's surface, the U.S. space agency announced on Monday.The newly-confirmed planet, Kepler-22b, is the smallest yet found to orbit in the middle of the habitable zone of a star similar to Sun. The planet is about 2.4 times the radius of Earth. Scientists don't yet know if Kepler-22b has a predominantly rocky, gaseous or liquid composition, but its discovery is a step closer to finding Earth-like planets.Previous research hinted at the existence of near-Earth-size planets in habitable zones, but clear confirmation proved elusive. Two other small planets orbiting stars smaller and cooler than Sun recently were confirmed on the very edges of the habitable zone, with orbits more closely resembling those of Venus and Mars.Kepler-22's star is a bit smaller than our sun, so its habitable zone is slightly closer in. The diagram shows an artist's rendering of the planet comfortably orbiting within the habitable zone, similar to where Earth circles the sun. Kepler-22b has a yearly orbit of 289 days. The planet is the smallest known to orbit in the middle of the habitable zone of a sun-like star. It's about 2.4 times the size of Earth."This is a major milestone on the road to finding Earth's twin, " said Douglas Hudgins, Kepler program scientist at the NASA Headquarters in Washington. "Kepler's results continue to demonstrate the importance of NASA's science missions, which aim to answer some of the biggest questions about our place in the universe."Kepler discovers planets and planet candidates by measuring dips in the brightness of more than 150,000 stars to search for planets that cross in front, or "transit," the stars. Kepler requires at least three transits to verify a signal as a planet."Fortune smiled upon us with the detection of this planet," said William Borucki, Kepler principal investigator at the NASA Ames Research Center who led the team that discovered Kepler-22b. "The first transit was captured just three days after we declared the spacecraft operationally ready. We witnessed the defining third transit over the 2010 holiday season."The Kepler science team uses ground-based telescopes and the Spitzer Space Telescope to review observations on planet candidates the spacecraft finds. The star field that Kepler observes in the constellations Cygnus and Lyra can only be seen from ground-based observatories in spring through early fall. The data from these other observations help determine which candidates can be validated as planets.Kepler-22b is located 600 light years away. While the planet is larger than Earth, its orbit of 290 days around a Sun-like star resembles that of Earth. The planet's host star belongs to the same class as Sun, called G-type, although it is slightly smaller and cooler.Of the 54 habitable-zone planet candidates reported in February 2011, Kepler-22b is the first to be confirmed. This finding will be published in The Astrophysical Journal.

ting fuel and benefits to agriculture from extended growing seasons."Global mitigation leading to a low climate change future reduces costs to Canada in the long term. This reinforces the argument that Canada would benefit environmentally and economically from a post 2012 international climate arrangement that systematically reduced emissions from all emitters - including Canada - over time," the report says.It recommends cooperation between governments, scientists and businesses to find ways to mitigate climate change and adapt to it.Canada's Minister of the Environment Peter Kent said the government has a plan to deal with global warming issues, which will be announced next month."Our government has a plan, a very good plan, to meet our target of reducing greenhouse gases by 17 percent from 2005 base levels, by 2020," Kent told Canada's House of Commons Thursday afternoon."We are moving forward to reduce greenhouse gases and, at the same time, we are investing in programs to help Canadians adapt to climate change," Kent said."Today's report merely echoes what our government has long recognized; that is, the importance of adaptation to climate change," he added.Earlier this week, several hundred people protested the government's policy of exploiting the oil sands deposits in western Canada.Environmentalists have criticized the Canadian government for not working hard enough to reduce CO2 emissions. Last year, a coalition of global warming activists gave Canada the "Fossil of the Year" award for failing to implement the Copenhagen Accord.

BEIJING, Nov. 30 (Xinhua) -- China's efforts to fight AIDS are impressive and its experience can be shared, according to Michel Sidibe, executive director of the Joint United Nations Programme on HIV/AIDS (UNAIDS)."We have seen progress in terms of new infections. The number of people going into treatment is increasing and the mortality rate is going down very quickly in China," Sidibe said during an interview with Xinhua on Wednesday.Sidibe said he was impressed by the country's political leadership and commitment to controlling AIDS.According to UNAIDS, the country has reported a 60-percent reduction in deaths due to AIDS over the past eight years.New HIV infection cases in China have been reduced from 70,000 people annually in 2005 to around 48,000 in 2011, according to the country's health department."However, China's success will not only be measured by what it has done for the Chinese people," Sidibe said.China has successful experience in reducing new HIV infections among intravenous drug users, which can be shared with the rest of the world, particularly east Europe and south Asia where HIV infections among drug abusers is a major challenge, he said.Sidibe suggested that the country should work with the rest of the developing world, particularly Africa, in fighting AIDS.A partnership between China and Africa will make a "big, big difference" in reducing AIDS mortality rates and introducing new technology and perspectives in Africa, said the official who had worked for UN in several African countries for more than two decades.Admitting the challenges of funding AIDS control programs during the current global economic downturn, Sidibe called for global solidarity and increasing shared responsibilities among countries."It is a critical moment now. It is not a time to stop investment but to redouble our efforts, to make sure that we will continue to make progress in the fight against HIV," Sidibe said."Getting to Zero" has been chosen as the main theme of World AIDS Day for the next five years, referring to UNAIDS' vision of "zero new HIV infections, zero discrimination and zero AIDS-related deaths."Sidibe met with Li Congjun, president of the Xinhua News Agency, on Wednesday before the interview. The agency has launched a global media campaign in cooperation with UNAIDS to raise public awareness about HIV/AIDS."The partnership (with Xinhua) is not only about writing news about HIV. It is about helping people to change their attitude and make decisions to help protect themselves," Sidibe said.

UNITED NATIONS, Nov. 21 (Xinhua) -- Dramatic progress in science, political leadership, and results indicate that 2011 was a "game changing" year for the international AIDS response, and much progress has been made in 2011 to check AIDS-related deaths since 1997, the peak of the epidemic, a new report released by the Joint United Nations Program on HIV/AIDS (UNAIDS) said on Monday."The Report on the Global AIDS Epidemic 2011" found that new infections were reduced by 21 percent since 1997, and deaths from AIDS-related illnesses decreased by 21 percent since 2005, according to the report.Furthermore, 47 percent (6.6 million) of the estimated 14.2 million people eligible for antiretroviral therapy treatment in low- and middle-income countries were accessing treatment, in increase of 1.35 million people since 2009.The report also found early signs that HIV treatment is having an impact on reducing the number of new HIV infections. As treatment reduces the viral load of a person living HIV to almost undetectable levels, it also reduces the risk of transmitting the virus to an uninfected partner, according to the report. Studies also show that treatment can be up to 96 percent effective in preventing HIV transmission among couples.Eleven countries, including many Sub-Saharan African countries, reached "close to universal access" for AIDS treatment, which is determined to be 80 percent access, in 2011.Botswana made the most dramatic progress in scaling up access to treatment, the report said. While sexual patterns remained relatively stable in the country since 2000, access to treatment increased from less than 5 percent in 2000 to more than 80 percent in 2011.Despite progress, however, the report does note that 2011 marks an unprecedented high the number of people infected with HIV worldwide.Globally, an estimated 34 million people are currently living with the infection. Approximately 2.7 million got infected with the virus in 2010, and as many as 1.8 million people died of AIDS- related illnesses in 2010.Yet the report also notes estimates that as many as 2.5 million deaths are estimated to have been averted in low- and middle- income countries due to increased access to HIV treatment since 1995."Now is not the time to reduce our efforts despite some good news on reducing new infections. Infections are decreasing, but not rapidly enough," said Kim Nichols, executive director of African Services Committee, on Monday at a press conference."There are fewer AIDS deaths, but with the number of infections increasing, prevention has to be the mainstay of our response," Nichols said.Indeed, the UNAIDS report calls for a new framework for investments which are focused on "high-impact, evidence-based, high-value strategies," according to a press release from the UNAIDS website.The framework, which aims to achieve universal access to treatment and prevention centers by 2015, requires a 22-24 billion US dollar funding increase by 2015.Given the withering state of the global economy -- donor funding for the AIDS response has dropped from 7.6 billion in 2009 to 6.9 billion in 2010 -- raising that kind of money may be a long shot. Regardless, UNAIDS'new investment plan calls for smarter uses of less money.According to the report, the framework will focus on high-risk populations like sex workers, men who have sex with men, and people who inject drugs and prevent infections among children, as well as invest in behavior change programs, condom promotion, and treatment, care and support for people living with HIV."The world faces a clear choice: maintain current efforts and make incremental progress, or invest smartly and achieve rapid success in the AIDS response," says the UNAIDS report.

WASHINGTON, Oct. 4 (Xinhua) -- Green tea may slow down weight gain and serve as another tool in the fight against obesity, according to U.S. Pennsylvania State University food scientists.Obese mice that were fed a compound found in green tea along with a high-fat diet gained weight significantly more slowly than a control group of mice that did not receive the green tea supplement, said Joshua Lambert, assistant professor of food science in agricultural sciences."In this experiment, we see the rate of body weight gain slows down," said Lambert.The researchers, who released their findings on Tuesday in the online version of Obesity, fed two groups of mice a high-fat diet. Mice that were fed Epigallocatechin-3-gallate -- EGCG -- a compound found in most green teas, along with a high-fat diet, gained weight 45 percent more slowly than the control group of mice eating the same diet without EGCG.In addition to lower weight gain, the mice fed the green tea supplement showed a nearly 30 percent increase in fecal lipids, suggesting that the EGCG was limiting fat absorption, according to Lambert. The green tea did not appear to suppress appetite. Both groups of mice were fed the same amount of high-fat food and could eat at any time."There seems to be two prongs to this," said Lambert. "First, EGCG reduces the ability to absorb fat and, second, it enhances the ability to use fat."A person would need to drink ten cups of green tea each day to match the amount of EGCG used in the study, according to Lambert. However, he said that recent studies indicate that just drinking a few cups of green tea may help control weight."Human data -- and there's not a lot at this point -- shows that tea drinkers who only consume one or more cups a day will see effects on body weight compared to nonconsumers," said Lambert.

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