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WASHINGTON, Jan. 2 (Xinhua) -- A systematic review of previous studies suggests that there may be a positive connection between physical activity and children's academic performance, according to a report published Monday in the Archives of Pediatrics & Adolescent Medicine.A group of scientists at the Vrije Universiteit (Free University) Medical Center in the Netherlands reviewed evidence on the relationship between physical activity and academic performance because of concerns that pressure to improve test scores may often mean more instructional time for classroom subjects with less time for physical activity.The authors identified 10 observational and four interventional studies for review, 12 of which were done in the United States, one in Canada and one in South Africa. Sample sizes ranged from 53 to about 12,000 participants between the ages of eight years and 18 years old. Follow-up varied from eight weeks to more than five years."According to the best-evidence synthesis, we found strong evidence of a significant positive relationship between physical activity and academic performance. The findings of one high-quality intervention study and one high-quality observational study suggest that being more physically active is positively related to improved academic performance in children," the report said.Background information in the article suggests that exercise may help cognition by increasing blood and oxygen flow to the brain, increasing levels of norepinephrine and endorphin to decrease stress and improve mood, and increasing growth factors that help create new nerve cells and support synaptic plasticity."More high-quality studies are needed on the dose-response relationship between physical activity and academic performance and on the explanatory mechanisms, using reliable and valid measurement instruments to assess this relationship accurately," the report concluded.

BEIJING,Nov. 9 (Xinhuanet) – Yinghuo-1, China's first interplanetary spacecraft, is set to hitch a ride with Russia's Phobos-Grunt Mars mission in the early hours on Wednesday, after a two-year delay.A Zenit-2SB rocket will carry Yinghuo-1 and Phobos-Grunt into space from the Baikonur Cosmodrome launch site in Kazakhstan.It is China and Russia's first joint Mars operation and also marks China's first voyage to the Red Planet, China Great Wall Industry Corp said in a news release on Tuesday.Yinghuo-1 will work in orbit with Phobos-Grunt for more than 12 months in collecting data on the Martian atmosphere.Both spacecraft will travel for more than 10 months before entering Martian orbit. During the trip, Yinghuo-1's power supply, communications and temperature gauge will be controlled from the Russian craft, scientists said.Both craft will orbit the planet three times before decoupling. The 106-kg Yinghuo-1 will circle Mars in an elliptical orbit, while Phobos-Grunt will actually land on Phobos, one of the two Martian moons, and bring back soil samples to Earth."The collaboration with Russia will enhance China's ability in deep space exploration, improve spacecraft design and development, and promote planetary exploration," said an unnamed official with the corp, a subsidiary of the China Aerospace Science & Technology Corp. Russia's Lavochkin Research and Production Association signed a cooperation contract, based on an agreement between the Chinese and Russian governments, with China Great Wall Industry Corp in 2007.Yinghuo-1, with a two-year lifespan, also has its own scientific goals.These include analyzing the planet's magnetic environment and ionosphere (upper atmosphere), taking images of topographical features and studying gravity fields on the Martian equator.Pang Zhihao, deputy editor-in-chief of the monthly publication, Space International, said China's focus on the planet's upper atmosphere is significant.Twenty detectors have explored parts of Mars, but most of them have looked for traces of life or water or places suitable for setting up colonies, he said.But studying the upper atmosphere is also vital if humans are to live on the planet, he said.The mission was set for October 2009, but later postponed to this year to enhance the reliability of the project.Only the United States, the former Soviet Union and the European Union have succeeded in landing probes on Mars. Five are in operation, four belong to the US and one belongs to the EU.At least 21 probes sent to the planet have failed. The Shanghai Academy of Spaceflight Technology under the CASC, which designed Yinghuo-1 in 23 months, said that the satellite posed a major technological challenge as the furthest space destination for China before had been the moon. The moon's average distance from Earth is about 384,000 km. The distance between Mars and Earth, depending on orbits, ranges from approximately 55 million km to about 350 million km.Yinghuo-1 will have to endure periods in the freezing dark side of the planet.It underwent simulated tests that matched the Martian temperature, - 260 C.Because of the distances involved, the satellite cannot rely on ground control to adjust position. It will rely on its own onboard computer, scientists said.

BEIJING, Oct. 28 (Xinhua) -- The Chinese government will donate one million U.S. dollars to quake-hit Turkey, Foreign Ministry spokeswoman Jiang Yu announced Friday.Jiang said that China has paid great attention to the situation since a 7.2-magnitude earthquake hit eastern Turkey on Sunday.Jiang noted that Premier Wen Jiabao sent a message of condolence to Turkish Prime Minister Recep Tayyip Erdogan immediately after the quake.The Red Cross Society of China has also donated 50,000 U.S. dollars, and China will continue to offer emergency relief aid to Turkey, she added.According to the Turkish government, as of Friday morning, 570 people were dead and 2,250 injured after the powerful earthquake struck the province of Van in eastern Turkey on Sunday.

RIO DE JANEIRO, Oct. 11 (Xinhua) -- The World Health Organization (WHO) on Tuesday highlighted Brazil's efforts to stop tuberculosis (TB) in its territory.According to a report released by the organization, Brazil achieved significant and sustained improvement in the fight against TB in the past years.Along with Cambodia, China, Uganda, and Tanzania, Brazil is one of the five nations which succeeded in reducing TB death rate in 2010 by half compared with 1990.The number of TB cases in the world fell for the first time in 2010, said the WHO. But with 8.8 million cases, the disease remained a major global health problem, said the organization.Although the TB death rate had significantly dropped over the years, the disease killed 1.4 million people around the world in 2010 alone.

MILAN, Italy, Dec. 1 (Xinhua) -- Italy has a new HIV infection every three hours on average, the national department of health said in a statement during the World AIDS Day commemoration Thursday.According to the statement, there were about 3,000 new infections in the country in 2010, with nearly one third of those affecting a foreigner.At least 157,000 people are presently estimated to be HIV-positive in Italy, though the country's AIDS infections and deaths continue to register a negative trend.Nearly 90 percent of the new patients acquired the virus through unprotected sex, and were mostly from the northern regions.People discovered to be HIV-positive in 2010 had an average age of 39 for men and 35 for women, more than a third of whom were diagnosed at an advanced stage of the disease, the statement said.Misinformation and a lack of preventive measures are a great cause for concern, Milan's councillor for social services and health Pierfrancesco Majorino told Xinhua at a campaign launched in Milan's La Scala Square."We have to keep in mind that AIDS is something very close to each of us, and adopt all most effective campaigns to provide complete and correct information," he said.A red ribbon -- the international symbol of AIDS awareness -- was formed by a group of people at the center of the square to remind everyone to stay alert to the disease.On World AIDS Day, disease prevention and health information campaigns were launched throughout Italy, including free ultra-rapid HIV-screening tests.

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