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LOS ANGELES, May 12 (Xinhua) -- A subsurface ocean of molten or partially molten magma exists beneath the surface of Jupiter's volcanic moon Io, the Jet Propulsion Laboratory (JPL) said on Thursday."The finding heralds the first direct confirmation of this kind of magma layer at Io and explains why the moon is the most volcanic object known in the solar system," JPL said in a press release posted on its website.The finding was based on new data analysis from NASA's Galileo spacecraft, said JPL.The research was conducted by scientists at the University of California, Los Angeles; the University of California, Santa Cruz;, and the University of Michigan, Ann Arbor. The study is published this week in the journal Science, JPL said."Scientists are excited we finally understand where Io's magma is coming from and have an explanation for some of the mysterious signatures we saw in some of the Galileo's magnetic field data," said Krishan Khurana, lead author of the study and former co- investigator on Galileo's magnetometer team at UCLA."It turns out Io was continually giving off a 'sounding signal' in Jupiter's rotating magnetic field that matched what would be expected from molten or partially molten rocks deep beneath the surface."Io produces about 100 times more lava each year than all the volcanoes on Earth, according to data released by JPL in Pasadena, Los Angeles.While Earth's volcanoes occur in localized hotspots like the "Ring of Fire" around the Pacific Ocean, Io's volcanoes are distributed all over its surface, JPL said, adding that a global magma ocean about 30 to 50 km beneath Io's crust helps explain the moon's activity."It has been suggested that both the Earth and its moon may have had similar magma oceans billions of years ago at the time of their formation, but they have long since cooled," said Torrence Johnson, a former Galileo project scientist based at JPL, an affiliation with NASA."Io's volcanism informs us how volcanoes work and provides a window in time to styles of volcanic activity that may have occurred on the Earth and moon during their earliest history," said Johnson, who was not directly involved in the study.NASA's Voyager spacecraft discovered Io's volcanoes in 1979, making that moon the only body in the solar system other than Earth known to have active magma volcanoes. The energy for the volcanic activity comes from the squeezing and stretching of the moon by Jupiter's gravity as Io orbits the largest planet in the solar system.Galileo was launched in 1989 and began orbiting Jupiter in 1995. Unexplained signatures appeared in magnetic field data from Galileo flybys of Io in October 1999 and February 2000. After a successful mission, the spacecraft was intentionally sent into Jupiter's atmosphere in 2003.

BEIJING, Jan. 30 (Xinhua) -- Chinese Vice Premier Li Keqiang Sunday urged scientists to learn from foreign experiences and increase their participation in international cooperation in polar and oceanic exploration.Li made the remarks after meeting with members of China's 27th Chinese Antarctic expedition team, the 22nd oceanic expedition, and scientists working in the country's Antarctic and Arctic stations via video and telephone.Li said many countries nowadays attached great importance to polar and oceanic exploration, and international competition had grown in promoting the peaceful utilization of these resources.Chinese Vice Premier Li Keqiang (R, front) shakes hands with a senior Chinese explorer in Beijing, capital of China, Jan. 30, 2011. Li conveyed Spring Festival greetings while meeting with members of China's 27th Chinese Antarctic expedition team, the 22nd oceanic expedition, and scientists working in the country's Antarctic and Arctic stations via video and telephone on Sunday."We are confident and capable of constantly improving our working conditions to conduct polar and oceanic exploration, and winning the initiative in this sector's future development," Li said.Li said the country would work to promote its marine economy and safeguard marine ecosystems, as well, and make full use of the achievements made in explorations to make reasonable development and utilization of ocean resources.China would also ensure the security of ocean passages, and safeguard its marine rights and interests, the vice premier said.Li also conveyed New Years greetings to the scientists for conducting research away from their homeland and families, and applauded their contribution to the country's progress in polar and oceanic research areas.

BEIJING, Feb. 9 (Xinhua) -- China's Ministry of Agriculture on Wednesday urged more measures be taken to minimize the impact of a drought due to the possibility that the winter drought may continue into spring.The country's winter wheat producing regions have suffered severe drought since October last year, and the possibility of spring drought is surfacing, Minister of Agriculture Han Changfu said in a statement posted on the ministry's website.Spring drought following the winter one will be a significant threat to summer grain production, he said.As of Wednesday, the drought had affected about 115.95 million mu (7.73 million hectares) of winter wheat in the country's eight key producing provinces, which account for 42.4 percent of the total winter wheat growing areas in the regions, the statement said.China's main wheat growing regions include the provinces of Shandong, Henan, Hubei, Anhui, Shanxi, Shaanxi, Gansu and Jiangsu.Han urged agricultural authorities to be "fully aware of the extreme significance" of a summer harvest this year and strengthen their efforts to assure a successful harvest.Summer grain and oil production is crucial to easing inflation pressures and stabilizing grain output for the entire year, he said. "To have a summer harvest, the current pressing job is to protect winter wheat from drought," he said.There are currently positive factors for a summer harvest, including an adequacy of water for spring irrigation, according to Han.He ordered local agricultural officials to work to stabilize spring planting areas and ensure that the areas for grain planting will be equal to that of last year.Local agricultural officials were also asked to strengthen supervision over market supplies of agricultural materials to keep prices stable.Also on Wednesday, the State Council, or the nation's cabinet, pledged to boost grain production by raising minimum purchase prices of grain, subsidizing the purchase of anti-drought technologies and adding funding for farm irrigation.

SAN FRANCISCO, April 22 (Xinhua) -- Apple and Google collect smartphone users' location information as part of their race to build massive databases, The Wall Street Journal reported on Friday after analyzing data and documents.According to the report, security analysts with the newspaper found that Apple's iPhone and smartphones running Google's Android operating system regularly transmit users' locations back to the two companies respectively, which is part of their race to build databases capable of pinpointing people's locations via smartphones.A report by research firm Gartner indicated that the market for location-based services is expected to rise to 8.3 billion U.S. dollars in 2014 from the current 2.9 billion dollars.In the case of Google, a security analyst with The Wall Street Journal said an HTC Android phone collected name, location, signal strength of any nearby Wi-Fi networks, and a unique phone identifier every few seconds and transmitted the data to Google at least several times an hour."All location sharing on Android is opt-in by the user," Google said in a statement to technology blog site All Things Digital, in response to the concern that how Android system uses location information."We provide users with notice and control over the collection, sharing and use of location in order to provide a better mobile experience on Android devices. Any location data that is sent back to Google location servers is anonymous and is not tied or traceable to a specific user," said the statement.Worries on the iPhone tracking issue surfaced on Wednesday after two British researchers announced at a technology conference in California that iPhone has been collecting users' location information and storing the data for extended periods of time.The researchers said starting on June 21 2010, after the release of iOS 4 mobile operating system, iPhones began logging and storing location information in a file, which shows the users' latitude and longitude and is timestamped to the second. They noted the information is not encrypted on the phone or on the iPhone backups made by iTunes and the file is also persistent, transferring itself to a new iOS device when the old one is replaced.They added they had no evidence that the file was being transmitted to Apple.On Thursday, U.S. congressman Edward Markey reacted angrily to the news in a letter to Apple CEO Steve Jobs, which is posted on Markey's official website.Markey asked Jobs to make a response within 15 business days or no later than May 12, saying "Apple needs to safeguard personal location information of its users to ensure that an iPhone doesn't become an iTrack."Apple has made no comment on the issue so far, but a letter it sent to U.S. Congress last July came under spotlight. In the letter, Apple said it collects Wi-Fi and GPS information when the phone is searching for a cellular connection and gathers the data to help build a "database with known location information."

WASHINGTON, April 6 (Xinhua) -- U.S. researchers have discovered two genes in which variation affects intake of caffeine, the most widely consumed stimulant in the world, according to a report described Wednesday in the open-access journal PLoS Genetics.A team of investigators from the National Cancer Institute, Harvard School of Public Health, Brigham and Women's Hospital, and the University of North Carolina at Chapel Hill examined genetic variation across the entire genome of more than 47,000 individuals from the U.S.They found the genes -- CYP1A2, which has previously been implicated in the metabolism of caffeine, and AHR, involved in the regulation of CYP1A2, played roles in regulating intake of caffeine. Individuals with the highest-consumption genotype for either gene consumed 40 mg more caffeine than those with the lowest-consumption genotype, equivalent to the amount of one-third cup of caffeinated coffee, or one can of cola.Caffeine is implicated in numerous physiological and medical conditions; it affects sleep patterns, energy levels, mood, and mental and physical performance. The identification of genes that have an impact on daily consumption offers opportunities to better understand these conditions. Further exploration of the identified genetic variants may provide insight into the speed of caffeine metabolism, how long caffeine circulates in the blood, or how strong the physiological effects of consuming a given amount of caffeine are.

来源：资阳报