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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.

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.

COPENHAGEN, May 29 (Xinhua) -- The number of confirmed E.coli cases has risen to 11 with at least another eight persons suspected of having the intestinal infection in Denmark, according to Denmark's National Serum Institute on Sunday.Five of the confirmed cases show symptoms of kidney failure which marks an advanced stage of the sickness, the institute said.Danish cucumbers are suspected of helping spread the E. coli bacteria believed to be causing a deadly outbreak of intestinal infection in Denmark and Germany, local media reported Sunday.The Danish cucumbers were mixed in Germany with cucumbers originating in the Netherlands, making it difficult to determine if Danish cucumbers are in fact contaminated.Denmark's Veterinary and Food Administration (DVFA) had earlier said the suspicion against Danish cucumber was "vague", but advised Danish consumers not to eat raw tomatoes, lettuces and cucumbers from Germany, and cucumber from Spain.It is now checking Danish cucumbers for traces of E. coli with results expected on Tuesday.Some Danish retailers have now removed these products from their supermarket shelves. And the Danish branch of fast-food chain McDonald's announced Saturday that it was dropping fresh cucumbers from its menu until further notice.The infection, which is food-borne, can be caused by eating raw or uncooked foods such as vegetables contaminated with the E. coli bacteria.Symptoms of infection include mild fever, bloody diarrhea and vomiting, and can last five to seven days. It can prove fatal in the very young, sick, or elderly.

MOSCOW, Aug. 24 (Xinhua) -- A Russian Progress cargo ship crashed into Siberia after failing to reach the right orbit Wednesday. The crash marked the second failure in space launch in less than a week and the third in this year, prompting local media to suspect a major reshuffle in Russia's space industry.UNPRECEDENTED FAILUREThe Progress M-12M unmanned freighter was launched to the International Space Station from Baikonur space center in Kazakhstan on Wednesday. It was expected to reach a near-Earth orbit in about nine minutes after launch.However, after the 325th second of the flight, which was just a few seconds before the vessel should reach the orbit, the ground control center lost it.Russian space agency Roscosmos confirmed later that the cargo ship failed to reach the orbit and fell down. Russian Progress M-12M cargo ship is launched to the International Space Station from Baikonur space center in Kazakhstan on Wednesday, Aug. 24, 2011. It has failed to reach the orbit, the Interfax news agency reported.The malfunction of the Soyuz-U rocket's engine was generally believed to be the cause of the accident, according to local media.A source in the space industry said the spaceship had sent a breakdown report while separating from the Soyuz rocket.Some unconfirmed reports said the fuel tank of the booster leaked and the engine was automatically turned off to avoid explosion.The wreckage of the Progress cargo ship has already fallen in southern Siberia's Altai Republic, where a big explosion was heard by locals, reported RIA Novosti news agency.A state investigation committee has been formed to look into the first ever loss of a Progress freighter.CONCERNS OVER FUTUREThe unprecedented accident raised concerns over the reserves of the six crew members on board the ISS.The ship was loaded with over 3.5 tons of supplies for the ISS, including scientific materials, oxygen, water and food.According to Russia's Ground Control, the loss of these supplies will not affect the ISS crew as there are enough stocks of necessities for two to three months.Also, there is no need for premature return of the crew, said Vladimir Solovyov, a space official.However, it still casts some shadow over the ISS program that relies on Russia exclusively following the retirement of U.S. shuttles.A source from the Russian space industry said the scheduled launches of the Soyuz rockets are likely to be suspended until the reasons of the accident are established.This means that current crew members of the ISS would likely stay longer in the space than planned, as the new members might not be able to replace them on schedule, the source explained. Solovyov said the launch of the next Progress is scheduled for October 28.So far, Roscosmos has refrained from comments regarding the possible halt in manned missions aboard Soyuz carrier rockets."Comments will follow. Now it is necessary to determine the causes of today's abortive launch of a Soyuz-u carrier rocket with the Progress M-2M transport ship," Roscosmos told Itar-Tass news agency.Local media raised the prospect of a major reshuffle in Russia' s space industry as the country has lost a total of six space vehicles over the past nine months.On Aug. 18, a carrier rocket Proton-M failed to deliver to the orbit communication satellite Express-AM4. Earlier in February, Russia had lost a satellite named Geo-IK2.In December 2010, a booster malfunction resulted in the loss of three satellites in the global positioning and navigation system GLONASS.

XIAMEN, July 23 (Xinhua) -- A rescue and breeding base for endangered Chinese white dolphins started a trial operational period on Saturday in the southeastern seaside resort of Xiamen. The base is the first of its kind in the country.The base, located on the city's Huoshaoyu Islet, includes a rescue center and a breeding area and can accommodate up to four to six white dolphins, said Pan Shijian, vice mayor of Xiamen.Previously, rescuers had to return injured white dolphins back to the sea after giving them simple medical treatment due to the lack of a rescue base, Pan said."From now on, the base will be a hospital for injured or stranded dolphins," he said.The base will also be used as a rehabilitation center for children with infantile autism and brain paralysis, with the dolphins acting as "doctors" during the children's recovery period, he added.The Chinese white dolphin mainly lives in the seas around Xiamen and the Pearl River estuary in south China. The dolphins are under first-class state protection.The Chinese Academy of Fishery Sciences estimates that about 2,000 of the dolphins are living in China's seas.

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