喀什治早泄有什么好办法(喀什包皮包茎科室) (今日更新中)

LOS ANGELES, April 18 (Xinhua) -- Sugarcane has the effect of cooling temperatures, thus playing role in stemming global warming, a new study has found.Sugarcane does so by reflecting sunlight back into space and by lowering the temperature of the surrounding air as the plants " exhale" cooler water, according to the study conducted by researchers at the Carnegie Institution's Department of Global Ecology.The researchers used data from hundreds of satellite images over 733,000 square miles (about 1,173 square kilometers) in Brazil, where sugarcane is widely grown. They measured temperature, reflectivity (also called albedo), and evapotranspiration -- the water loss from the soil and from plants as they exhale water vapor.The findings showed that expansion of sugarcane in areas previously occupied by other Brazilian crops cools the local climate.Converting from natural vegetation to crop/pasture on average warmed the cerrado by 2.79 Fahrenheit (1.55 Centigrade, but that subsequent conversion to sugarcane, on average, cooled the surrounding air by 1.67 Fahrenheit (0.93 Centigrade), the researchers said in the study published in the April issue of Nature Climate Change."We found that shifting from natural vegetation to crops or pasture results in local warming because the plants give off less beneficial water. But the bamboo-like sugarcane is more reflective and gives off more water -- much like the natural vegetation," said lead researcher Scott Loarie. "It's a potential win-win for the climate -- using sugarcane to power vehicles reduces carbon emissions, while growing it lowers the local air temperature."Brazilians are world leaders in using biofuels for gasoline. About a quarter of their automobile fuel consumption comes from sugarcane, which significantly reduces carbon dioxide emissions that otherwise would be emitted from using gasoline.The researchers emphasized that the beneficial effects are contingent on the fact sugarcane is grown on areas previously occupied by crops or pastureland, and not in areas converted from natural vegetation. It is also important that other crops and pastureland do not move to natural vegetation areas, which would contribute to deforestation.So far most of the thinking about ecosystem effects on climate considers only impacts from greenhouse gas emissions. But according to co-researcher Greg Asner, "It's becoming increasingly clear that direct climate effects on local climate from land-use decisions constitute significant impacts that need to be considered core elements of human-caused climate change."

WASHINGTON, March 22 (Xinhua) -- A long-term study by Greek researchers has shown the effectiveness of replacing bone marrow, purposely destroyed by chemotherapy, with autologous (self) stem cells in treating people with aggressive forms of multiple sclerosis (MS).The study was published on Tuesday in Neurology, the medical journal of the American Academy of Neurology.For the treatment, chemotherapy drugs are used to kill all of the patient's blood cells, including the immune cells that are believed to be attacking the body's own central nervous system. Bone marrow stem cells removed from the patient are purified and transplanted back into the body, which saves life by replacing the blood cells and also is proposed to "reboot" the immune system.A human embryonic stem cell line derived at Stanford University is seen in this handout photo released to Reuters by the California Institute for Regenerative Medicine, March 9, 2009The study followed 35 people for an average of 11 years after transplant. The study involved people with rapidly progressive MS who had tried a number of other treatments for MS with little or no effect. All were severely disabled by the disease, with an average score of six on a scale of disease activity that ranges from zero being a normal neurological examination to 10 meaning death due to MS.A score of six means able to walk with a cane or crutch; a seven is mainly in a wheelchair. All had worsened by at least one point on the scale in the year prior to the transplant.After the transplants, the probability of participants having no worsening of their disease for 15 years was 25 percent. The probability was higher -- 44 percent -- for those who had active brain lesions, which are a sign of disease activity, at the time of the transplant.For 16 people, symptoms improved by an average of one point on the scale after the transplant, and the improvements lasted for an average of two years. The participants also had a reduction in the number and size of lesions in their brains. Two people (six percent) died from complications related to the transplant at two months and 2-1/2 years post-transplant.Study author Vasilios Kimiskidis, of Aristotle University in Thessaloniki, Greece, noted that more research is needed on this treatment, including studies that compare people receiving the treatment to a control group that does not receive the treatment."Keeping that in mind, our feeling is that stem cell transplants may benefit people with rapidly progressive MS," he said. "This is not a therapy for the general population of people with MS but should be reserved for aggressive cases that are still in the inflammatory phase of the disease."

WASHINGTON, May 2 (Xinhua) -- Rice originated in China, a team of U.S. genome researchers has concluded in a study tracing back thousands of years of evolutionary history through large-scale gene re-sequencing.Their findings, which appear Monday in the latest issue of the Proceedings of the National Academy of Sciences (PNAS), indicate that domesticated rice may have first appeared as far back as approximately 9,000 years ago in the Yangtze Valley of China. Previous research suggested domesticated rice may have two points of origin -- India as well as China.Asian rice, Oryza sativa, is one of world's oldest crop species. It is also a very diverse crop, with tens of thousands of varieties known throughout the world. Two major subspecies of rice -- japonica and indica -- represent most of the world's varieties. Sushi rice, for example, is a type of japonica, while most of the long-grain rice in risottos are indica.Because rice is so diverse, its origins have been the subject of scientific debate. One theory -- a single-origin model -- suggests that indica and japonica were domesticated once from the wild rice O. rufipogon.Another -- a multiple-origin model -- proposes that these two major rice types were domesticated separately and in different parts of Asia. The multiple-origin model has gained currency in recent years as biologists have observed significant genetic differences between indica and japonica, and several studies examining the evolutionary relationships among rice varieties supported more than domestication in both India and China.In the PNAS study, the researchers re-assessed the evolutionary history, or phylogeny, of domesticated rice using previously published datasets, some of which have been used to argue that indica and japonica rice have separate origins. Using more modern computer algorithms, however, the researchers concluded these two species have the same origin because they have a closer genetic relationship to each other than to any wild rice species found in either India or China.In addition, the study's authors examined the phylogeny of domesticated rice by re-sequencing 630 gene fragments on selected chromosomes from a diverse set of wild and domesticated rice varieties. Using new modeling techniques, which had previously been used to look at genomic data in human evolution, their results showed that the gene sequence data was more consistent with a single origin of rice.In the study, the investigators also used a "molecular clock" of rice genes to see when rice evolved. Depending on how the researchers calibrated their clock, they pinpointed the origin of rice at possibly 8,200 years ago, while japonica and indica split apart from each other about 3,900 years ago. The study's authors pointed out that these molecular dates were consistent with archaeological studies.Archaeologists have uncovered evidence in the last decade for rice domestication in the Yangtze Valley beginning approximately 8, 000 to 9,000 years ago while domestication of rice in the India's Ganges region was around about 4,000 years ago."As rice was brought in from China to India by traders and migrant farmers, it likely hybridized extensively with local wild rice," explained New York University biologist Michael Purugganan, one of the study's co-authors. "So domesticated rice that we may have once thought originated in India actually has its beginnings in China."

LOS ANGELES, April 1 (Xinhua) -- A NASA Gulfstream-III aircraft equipped with a synthetic aperture radar is scheduled to depart Sunday, April 3 on a nine-day mission to image Hawaii volcanoes, the Jet Propulsion Laboratory (JPL) announced on Friday.The aircraft will fly from the Dryden Aircraft Operations Facility in Palmdale, California to the Big Island of Hawaii to study the Kilauea volcano that recently erupted, said JPL in Pasadena, Los Angeles.The mission will help scientists better understand processes occurring under Earth's surface, JPL said.Developed by JPL, the Uninhabited Aerial Vehicle Synthetic Aperture Radar, or UAVSAR, uses a technique called interferometric synthetic aperture radar that sends pulses of microwave energy from the aircraft to the ground to detect and measure very subtle deformations in Earth's surface, such as those caused by earthquakes, volcanoes, landslides and glacier movements.As the Gulfstream-III flies at an altitude of about 12,500 meters, the radar, located in a pod under the aircraft's belly, will collect data over Kilauea, according to JPL.The UAVSAR's first data acquisitions over this volcanic region took place in January 2010, when the radar flew over the volcano daily for a week. The UAVSAR detected deflation of Kilauea's caldera over one day, part of a series of deflation-inflation events observed at Kilauea as magma is pumped into the volcano's east rift zone.This month's flights will repeat the 2010 flight paths to an accuracy of within 5 meters, or about 16.5 feet, assisted by a Platform Precision Autopilot designed by engineers at NASA's Dryden Flight Research Center on Edwards Air Force Base, California, JPL said.By comparing these camera-like images, interferograms are formed that reveal changes in Earth's surface, said JPL.Between March 5 and 11, 2011, a spectacular fissure eruption occurred along the east rift zone. Satellite radar imagery captured the progression of this volcanic event."The April 2011 UAVSAR flights will capture the March 2011 fissure eruption surface displacements at high resolution and from multiple viewing directions, giving us an improved resolution of the magma injected into the east rift zone that caused the eruption," said JPL research scientist Paul Lundgren."Our goal is to be able to deploy the UAVSAR on short notice to better understand and aid in responding to hazards from Kilauea and other volcanoes in the Pacific region covered by this study," Lundgren added.

VIENNA, March 28 (Xinhua) -- Stress hormone is helpful in alleviating acrophobia, a morbid fear of great heights, according to a study by Austrian scientists.They published the findings in the recent Proceedings of the National Academy of Sciences of the United States of America.Frank H. Wilhelm, professor from the Department of Clinical Psychology, Psychotherapy and Health Psychology at the University of Salzburg, Austria, carried out the first study demonstrating the clinical effectiveness of hormones released at periods of high stress in anxiety.The study found hormones and other drugs could be a good addition to behavioral treatment of several anxiety disorders.People with acrophobia have formed a so-called fear memory, which could be activated when the fear-causing stimulus occurs. They tend to react with feelings of extreme fear and anxiety to the ride in a glass elevator.Hence, scientists conducted a confrontation therapy, trying to mask this memory.A total of 40 experimental subjects had been put in a safe environment to constantly confront the fear-inducing stimulus, until they had a new reaction to the perceived threat.Observations also suggested hormones released in high stress had impact on learning and memory.Additionally, stress hormones were believed to facilitate the storage of new, anxiety-free competence and experienced confidence in the therapy. Animal studies have shown that this emotional relearning benefits from cortisol, one of the stress hormones.

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