Anh ngữ đặc biệt 521 health (VOA)

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• published: 10 Jan 2012
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Chương trình học tiếng Anh của VOA: Special English Health Report - Malaria / Insecticide. Xin hãy vào http://www.youtube.com/user/VietSpecialEnglish để xem các bài kế tiếp. This is the VOA Special English Health Report. Malaria is caused by a parasite spread by infected mosquitoes. The World Health Organization, in its latest estimate, says the disease caused seven hundred eighty-one thousand deaths in two thousand nine. Most of those deaths were in children in Africa. Worldwide there were two hundred twenty-five million cases of malaria. Both of these numbers represent improvements. In two thousand there were an estimated two hundred thirty-three million cases of malaria and almost a million deaths. Malaria remains a major problem in Africa, but there have been some successes. Deaths in Rwanda, for example, have been reduced by sixty percent. There are still no vaccines to prevent malaria. The main way for communities to control the disease is by controlling mosquitoes. In a recent study, researchers in West Africa have shown that spraying insecticide indoors can greatly reduce malaria transmission. two main targets: the parasite itself and the mosquito that carries the parasite. Insecticides target the mosquito. But over time the insects develop resistance to the chemicals. This has been happening with current mosquito killers, including chemicals known as pyrethroids. Gil Germain Padonou and other researchers in Benin tested another insecticide. This one is called bendiocarb. They tested it with indoor spraying at sites throughout Benin. There were fewer mosquito bites in homes sprayed with bendiocarb. More importantly, none of the three hundred fifty-thousand people who lived there got malaria-infected mosquito bites during the test. Peter Hotez heads the American Society of Tropical Medicine and Hygiene, which published the research. He says, "This is what this bendiocarb is all about, showing that it's efficacious -- at least in this setting in Benin, in a real, live field setting. So it provides a potentially good alternative where there's been high development of resistance to pyrethroids." Dr. Hotez says the effectiveness in the test does not mean all malaria programs should use bendiocarb, or that indoor spraying should be the only method used. "We're going to have to throw multiple things out there in order to see what the optimal combination is to achieve control." Bendiocarb is widely used against a number of different insects. The insecticide is considered relatively safe when used as directed. This is the VOA Special English Education Report. A program in the United States brings scientists and engineers into elementary schools to teach teachers more about how to teach science. Dave Weiss is a retired engineer. One day each week he volunteers at Georgian Forest Elementary School in Silver Spring, Maryland, near Washington. He works with teacher Fred Tenyke on science projects for ten-year-olds. He says, "Fred is so enthusiastic and he's so much fun with the kids. I can see that he really loves what he's doing. I get as much pleasure from helping the teachers as I do helping the students." Student Jada Lockwood she says enjoys Mr. Weiss' visits to her classroom. She likes the drawings he uses to explain scientific ideas. The American Association for the Advancement of Science sponsors the Senior Scientists and Engineers program. Dave Weiss has been a volunteer in that program for many years. The scientists and engineers help teachers in elementary schools improve their skills. Mr. Weiss says he and the other volunteers help teachers by providing hands-on expertise. He notes that science is an area in which many elementary school teachers have limited experience. "In elementary school, for the most part, your regular classroom teacher is responsible for teaching science, along with reading and math, and if they don't have a strong science background, just by nature, they're going to tend to underrepresent science in the curriculum." Fred Tenyke agrees. He just started teaching science classes a few months ago. He says: "A lot of time I'll spit out information I learned in the book, or things that are part of the curriculum. Dave helps me learn how to supplement that information so that it's more relevant to them, so that it will be more relevant to their work experience later on in life." Fifteen-year-olds in the United States scored about average in science among countries that took part in testing by the OECD in two thousand nine. The OECD is the Organization for Economic Cooperation and Development. But Dave Weiss says he is hopeful for the future. He says he tries to give elementary school students a solid foundation. His hope is that "they'll develop a curiosity about what's going on around them."