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BEIJING, July 19 (Xinhuanet) -- Amazon on Monday launched its Kindle textbook rental service, which allows students to rent "tens of thousands of textbooks", according to Los Angeles Times.The e-book textbook rental service will help students save as much as 80 percent on some titles.Amazon said that students can now rent textbooks from 30 to 360 days and can either rent them again or purchase them once the rental period is up."Students tell us that they enjoy the low prices we offer on new and used print textbooks. Now we're excited to offer students an option to rent Kindle textbooks and only pay for the time they need—with savings up to 80 percent off the print list price on a 30-day rental," Dave Limp, vice president of Amazon Kindle said, according to PC Magazine.Rentals can be read on Amazon's Kindle eReaders, and Kindle apps for PCs, as well as smartphones and tablet computers running Apple's iOS, Microsoft Windows Phone 7 and Google's Android operating system.Rentals also have a clear advantage over physical copies that students' notes and highlighted content will be stored in the Amazon Cloud, and can be accessed if students rent the books again or buy at a later time.

CHANGSHA, July 17 (Xinhua) -- Chinese State Councilor Liu Yandong has called for more communications in language and culture among the people in China and foreign countries.Liu made the remarks during a meeting with the contestants of the 10th "Chinese Bridge" competition, an international Chinese proficiency competition for foreign college students, which opened Saturday in Changsha, capital of central Hunan Province.The "Chinese Bridge" competition has attracted over 100,000 college students from more than 70 countries over the past ten years, and contestants have improved their Chinese language, experienced the Chinese culture and established deep friendship with others during the competition, Liu said.She said that language is a tool for cultural communications, and linguistic learning and exchanges can promote the mankind's civilization and progress in a broader reach."The Chinese government always encourages the public, especially the youths, to learn foreign languages, and through the learning, they are enlightened on the diversified cultures around the world," she said."This also helps promote the good-will exchanges and cooperation among the Chinese and foreign peoples," she added.Liu said the Chinese government is also making efforts to meet the needs of foreign people to learn the Chinese language. She called on foreign young students to improve their Chinese proficiency and to use the Chinese language as a bridge to fell a real China in a comprehensive way.She expressed her hope that the foreign students will spread the good will and sincerity of the Chinese people to other parts of the world, in order to promote the joint efforts for the peace and prosperity of the world.

BERLIN, June 6 (Xinhua) -- The German authorities said on Monday that Germany's first sample tests of the allegedly contaminated bean sprouts have found no E. coli strains that have sickened more than 2,000 people in Europe.According to a statement issued by the Agriculture Ministry of the Lower-Saxony state, 23 of 40 samples concerning the suspected sprouts from a market garden in the state have tested negative, and further tests are still pending."Based on the initial findings in tests of some of the samples, especially the seeds, we assume that intensive analytical efforts are needed to prove that the suspected pathogen is really there," the statement said.Beansprouts and salad sprouts are seen in this picture illustration taken in Berlin June 6, 2011.  The German authorities said on Monday that Germany's first sample tests of the allegedly contaminated bean sprouts have found no E. coli strains that have sickened more than 2,000 people in EuropeLower-Saxony's Agriculture Minister Gert Lindemann said Sunday that a market garden in the rural district of Uelzen had provided a connection "involving all the main outbreaks" of the disease.Restaurants and food outlets of almost all E. coli-affected areas had received shipments of sprouts directly or indirectly from the company, state officials said.The German authorities have been racing to track down the source of the pathogen since the outbreak, which has infected people in 12 countries, all of whom had once traveled in northern Germany.More than 600 of those infected have developed Hemolytic Uremic Syndrome, a potentially deadly complication attacking the kidneys.The E. coli source was first thought to be cucumbers from Spain, which has caused huge loses for Spain farmers. However, this conclusion was overthrown by laboratory tests in Hamburg later.

LOS ANGELES, June 17 (Xinhua) -- The size of low-oxygen zones created by respiring bacteria is extremely sensitive to changes in depth caused by oscillations in climate, thus posing a distant threat to marine life, a new study suggests."The growth of low-oxygen regions is cause for concern because of the detrimental effects on marine populations -- entire ecosystems can die off when marine life cannot escape the low- oxygen water," said lead researcher Curtis Deutsch, assistant professor of atmospheric and oceanic sciences at University of California, Los Angeles."There are widespread areas of the ocean where marine life has had to flee or develop very peculiar adaptations to survive in low- oxygen conditions," Deutsch said in the study to be published in an upcoming print edition of the journal Science.A team led byDeutsch used a specialized computer simulation to demonstrate for the first time that fluctuations in climate can drastically affect the habitability of marine ecosystems.The study also showed that in addition to consuming oxygen, marine bacteria are causing the depletion of nitrogen, an essential nutrient necessary for the survival of most types of algae."We found there is a mechanism that connects climate and its effect on oxygen to the removal of nitrogen from the ocean," Deutsch said. "Our climate acts to change the total amount of nutrients in the ocean over the timescale of decades."Low-oxygen zones are created by bacteria living in the deeper layers of the ocean that consume oxygen by feeding on dead algae that settle from the surface. Just as mountain climbers might feel adverse effects at high altitudes from a lack of air, marine animals that require oxygen to breathe find it difficult or impossible to live in these oxygen-depleted environments, Deutsch said.Sea surface temperatures vary over the course of decades through a climate pattern called the Pacific Decadal Oscillation, during which small changes in depth occur for existing low-oxygen regions, Deutsch said. Low-oxygen regions that rise to warmer, shallower waters expand as bacteria become more active; regions that sink to colder, deeper waters shrink as the bacteria become more sluggish, as if placed in a refrigerator."We have shown for the first time that these low-oxygen regions are intrinsically very sensitive to small changes in climate," Deutsch said in remarks published Friday by the American Association for the Advancement of Science on its website. "That is what makes the growth and shrinkage of these low-oxygen regions so dramatic."Molecular oxygen from the atmosphere dissolves in sea water at the surface and is transported to deeper levels by ocean circulation currents, where it is consumed by bacteria, Deutsch said."The oxygen consumed by bacteria within the deeper layers of the ocean is replaced by water circulating through the ocean," he said. "The water is constantly stirring itself up, allowing the deeper parts to occasionally take a breath from the atmosphere."A lack of oxygen is not the only thing fish and other marine life must contend with, according to Deutsch. When oxygen is very low, the bacteria will begin to consume nitrogen, one of the most important nutrients that sustain marine life."Almost all algae, the very base of the food chain, use nitrogen to stay alive," Deutsch said. "As these low-oxygen regions expand and contract, the amount of nutrients available to keep the algae alive at the surface of the ocean goes up and down. "Understanding the causes of oxygen and nitrogen depletion in the ocean is important for determining the effect on fisheries and fish populations, he said.

来源：资阳报