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LOS ANGELES, June 20 (Xinhua) -- About 8 percent of children, or nearly 6 million in the U.S., have a food allergy, a much higher rate than previously estimated, a new study suggests.Not only is this estimate higher than some previous research has reported, allergic reactions are often severe and that many kids have more than one allergy, according to the study published online in Pediatrics on Monday.Of the children with confirmed (or probable) food allergies, about 39 percent had had severe reactions in the past, and 30 percent had more than one allergy, the study found.In the current study, researchers at the Northwestern University Feinberg School of Medicine surveyed parents of more than 38,000 children about whether their child had been diagnosed with a food allergy and had one or more of a number of symptoms, including anaphylaxis; swelling of the lips, eyes or face and skin rashes or hives.The study pinned down peanuts (25 percent of food-allergic children), milk (21 percent) and shellfish (17 percent) as the top three allergens.Severe reactions were most common among children with tree nut (more than 50 percent) and fin fish (more than 40 percent) allergies. The reactions were more likely among 14- to 17-year- olds compared with 0- to 2-year-olds, and more likely in children with multiple food allergies, the study found."These findings provide critical epidemiologic information to guide strategies for the prevention of food-induced reactions and for the diagnosis and management of childhood food allergies," the study noted.

LOS ANGELES, May 30 (Xinhua) -- The American Academy of Pediatrics (AAP) warned on Monday that children should keep away from energy drinks which may be dangerous for minors.The AAP urged young children and teens to avoid energy drinks entirely, saying routine consumption of sports drinks should be limited or eliminated.Energy drinks include such popular brands as Red Bull, AMP and Rockstar, the AAP said in a report.These drinks, the report said, tend to be heavily caffeinated, potentially having several times the level of caffeine found in a cup of coffee.In addition, manufacturers often add sugar and herbal stimulants such as guarana and taurine to the drinks, which are popular among kids, according to the report."There's no place for energy drinks for kids," said report co-author Dr. Marcie Beth Schneider, an adolescent physician in Greenwich, Connecticut. "There's a place for sports drinks, but that place is very specific."The caffeine in energy drinks can lead to high blood pressure, high heart rate and insomnia, she said.The other ingredients can boost the power of the caffeine, she said, adding that the drinks will have a greater effect on children because they're smaller than adults."Kids don't need to have this," she said. "This is not something they should be drinking."Schneider declined to identify any energy drinks that may be better than others for kids who insist on drinking them. If kids use energy drinks because they're tired, she said, they should get more rest instead of chugging caffeine.Half of the nation's 5,448 reported caffeine overdoses in 2007 were in people under age 19, although it's not known how many of the cases were the result of energy drink consumption, according to statistics provided by the AAP.

LOS ANGELES, June 5 (Xinhua) -- A latest study has found no evidence that screening for ovarian cancer may reduce the risk of dying from the disease, it was reported on Sunday.Screening, however, does increase the likelihood of unnecessary invasive procedures, according to researchers at the University of Utah.The researchers presented their findings at an on-going meeting of the American Society of Clinical Oncology in Chicago, The Los Angeles Times said.Researchers studied 78,216 women, ages 55 to 74, who participated in the National Cancer Institute's Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Half of the women received the usual care from their OB-gyns, and half received a CA 125 screening every year for six years and an ultrasound every year for four years. They were then followed for a maximum of 12 years.The researchers observed 212 ovarian cancers in the screened group and 176 in the normal care group. There were 118 ovarian cancer deaths in the screened group and 100 in the normal care group. The differences were not statistically significant. Overall, there were 2,924 deaths from all causes in the screened group and 2,914 in the normal care group.But the researchers also observed that 3,285 women had false- positive diagnoses from the screening. Among those, 1,080 underwent surgery that included an oophorectomy (surgical removal of one or both ovaries). Fifteen percent of those who had surgery developed major complications as a result. Overall, 1,771 women in the screened group (7.7 percent) had an oophorectomy, compared with 1,304 in the normal care group (5.8 percent)."We conclude that annual screening for ovarian cancer ... does not reduce disease-specific mortality in women at average risk for ovarian cancer but does increase invasive medical procedures and associated harms," the researchers said in the study.New data presented at the meeting also showed that the widely used cancer drug Avastin can improve treatment of ovarian cancer, The Times said.About 21,880 American women are diagnosed with ovarian cancer each year and about 13,850 die from it, according to the American Cancer Society. Because it produces few symptoms, the disease is typically not diagnosed until it has become advanced and spread throughout the body. As a result, five-year survival is only about 30 percent, and the disease is one of the five most deadly cancers among women. Being able to detect the cancer at an earlier stage when it might be more curable could thus, theoretically, improve the survival rate.The tests most commonly used to detect ovarian cancer include a transvaginal ultrasound to look for tumor masses and a blood test that screens for increased levels of a tumor marker called CA 125.

SAN FRANCISCO, July 15 (Xinhua) -- U.S. microblogging platform Twitter on Friday marked its fifth anniversary since public debut."Twitter, then called Twttr, opened to the public five years ago today," the company said in a Tweet, a short message within 140 characters users are allowed to communicate on the website."Twttr is a new mobile service that helps groups of friends bounce random thoughts around with SMS," co-founder Biz Stone described the service in a blog post on July 13, 2006, two days before its public debut."There were 224 Tweets sent on July 15, 2006. Today, users send that many Tweets in less than a tenth of a second," said the San Francisco-based company.Twitter said more than 600,000 new users signed up on Thursday while it took it more than 16 months to reach the first 600,000 Twitter accounts.The tipping point for the service's popularity was the 2007 South by Southwest festival, a set of film, interactive and music festivals and conferences that take place every March in Austin, Texas. During the event, the Tweets sent per day grew from 20,000 to 60,000.With an estimated user base of 200 million worldwide, some 200 million Tweets are generated and 1.6 billion search queries are handled every day, the company said.According to research firm EMarketer, advertising sales on Twitter is expected to reach 150 million U.S. dollars this year. SharesPost, a secondary market for privately held companies, has assessed Twitter's current worth at 6.8 billion dollars.

WELLINGTON, June 10 (Xinhua) -- Scientists have uncovered an almost complete picture of the remains of a geological formation that was one of the great wonders of the 19th Century world before it was covered in ash and water during a volcanic eruption.Scientists from New Zealand and the United States said Friday they had discovered the White Terraces, half of the famous Pink and White Terraces in the central North Island's Lake Rotomahana.The same group of scientists found the remnants of the pink half of the former world-famous tourist attraction on the lake floor in January.The Pink and White Terraces were buried by the eruption of Mount Tarawera 125 years ago on 10 June 1886. The two sets of cascading silica terraces were separated by several hundred metres.The two formerly glistening terraces were formed on the shores of the lake, where the silica rich waters were warmed by the magma beneath.In the late 19th Century, the cascading terraces attracted people from all over the world. The White Terraces were the larger and stretched to a height of 30 meters, forming a 240-meter face. Visitors could walk up to a crater platform where they could bathe in the clear blue waters in naturally-formed basins up to three meters deep.Project Leader Cornel de Ronde, of New Zealand's GNS Science geosciences research institute, said the sonar images from Lake Rotomahana showed the lake floor was covered overwhelmingly by soft sediment and mud.The side-scan sonar data of the lake floor was collected on the last day of the 10-day project at Lake Rotomahana during the southern summer, but was analyzed using new software, which became available after the data collection had finished.The scientists found the sonar data contained images of hard, crescent-shaped structures on the lake bed in a similar location to where the White Terraces were before the eruption of 1886.The structures were about 60 meters below the surface, a similar depth to the Pink Terraces found in January. The lake is about 122 meters deep at its deepest point."The two places on the lake floor where we encountered hard, up- standing crescent-shaped features correspond to the locations of the Pink and White Terraces before the Tarawera eruption," de Ronde said."The sonar image that appears to show part of the White Terraces came to light after the project had finished. It shows a horizontal segment of terraces over 100 meters long, although we don't know which part of the terraces it is."The rounded terrace edges are standing up from the lake floor by about a meter in some places. The sonar images of both sets of terraces are strikingly similar."Scientists managed to capture several color photographs of part of the Pink Terraces in January, but they did not lower an underwater camera over the White Terraces location during the project as they were unaware of what the sonar data was showing at the time.The fate of the remaining sections of the Pink and White Terraces was unclear, said a statement from GNS. "They might have been destroyed in the eruption. Alternatively, they could be lying under thick sediment, which is impenetrable to sonar signals sent out by the two autonomous underwater vehicles (AUVs) used in the survey."De Ronde said finding remnants of both sets of terraces was a remarkable outcome for the project."The project team was absolutely thrilled in January when we realised our AUVs had detected remnants of the Pink Terraces. Finding part of what we believe is the White Terraces as well has been surprising and very satisfying."The original aim of the project at Lake Rotomahana was to map the lake floor and investigate the extensive geothermal system under the lake and how it evolved from an on-land geothermal system to a submerged one. Anything else was a bonus," de Ronde said."It's gratifying to be part of a science project that can answer a century-old mystery about the fate of the Pink and White Terraces."De Ronde said the announcement of the find was timed to coincide with the 125th anniversary of Tarawera's eruption.The 10-day project was a collaboration involving GNS Science, Woods Hole Oceanographic Institution in Massachusetts, Lamont- Doherty Earth Observatory at Columbia University in New York, the National Oceanic and Atmospheric Administration in Seattle, and New Zealand's University of Waikato.