1. 英语小说: 小说下载 在线小说 读书推荐
  2. 英语短文: 家庭保健 健康生活 幸福情感
  1. 能力: 英语口语 英语听力 职场英语 商务英语 影视英语 少儿英语 行业英语 双语阅读
  2. 考试: 英语四级 英语六级 笔译口译 英语单词 考研英语 课堂英语 英语考试 新概念

英语阅读

听力入门英语演讲VOA慢速英语美文听力教程英语新闻名校课程听力节目影视听力英语视频

VOA科学报道:科学家利用细菌阻止携带疾病蚊子繁殖

cocotang 于2017-03-13发布 l 已有人浏览
增大字体 减小字体
VOA慢速英语,科学报道:Common Bacteria May Control Disease-Carrying Insects 科学家利用细菌阻止携带疾病蚊子繁殖
    小E英语欢迎您,请点击播放按钮开始播放……
38.jpg
Scientists think they have discovered a way to use a common bacteria to stop disease-carrying mosquitoes from reproducing.
They say the discovery could make it possible to control the mosquito that spreads two viral diseases: Zika virus and dengue. The bacteria is called Wolbachia. It can infect up to 70 percent of the insect species on Earth. The bacteria has changed in different ways over time. Some insects need it to stay alive. Wolbachia can act as a parasite in other insects. It can even affect the ability of eggs to produce young. However, experts say it does not infect many disease-carrying mosquitoes. But researchers may have found a way to use the bacteria on mosquitoes that carry two viral diseases, Zika and dengue. Experts say a woman infected with Zika virus early in her pregnancy is at risk of giving birth to a baby with microcephaly. Microcephaly causes mental and physical disability, seizures and sometimes death. Dengue can make people very sick. A person develops a condition like influenza. The disease can also turn deadly. John Bechmann is an entomologist — someone who studies insects -- at Yale University in Connecticut. "It's kind of been the issue with the Wolbachia field is that all of the insects that are really, really medically relevant don't have their own Wolbachia infection. So that's one reason why this is such an important discovery is because that's been one thing that's limited the field is people have always tried to make these fake or non-natural infections that can infect these mosquitoes. Now we don't have to do that -- we can just put the genes in." Aedes aegypti is the name of a mosquito that carries Zika and dengue. Researchers at Yale and Vanderbilt University in Tennessee are studying the Wolbachia bacteria. They reported finding two genes that might make the mosquitoes unable to have young. The researchers have performed successful experiments in fruit flies. And they believe they can do the same with mosquitoes. The scientists reported success with two ways to stop the spread of Zika and dengue. The first was to place many male mosquitoes carrying Wolbachia in an area. When these males mate with uninfected females, the bacteria kills life in any eggs the female is carrying. The other method involved leaving male and female mosquitoes infected with Wolbachia in a mosquito population. Over time, the Wolbachia-infected mosquitoes replaced the Zika- and dengue-infected mosquitoes by making them sterile. Reports on the Wolbachia gene discovery were published in the journals Nature and Nature Microbiology. John Bechmann says controlling the two diseases may one day be as simple as breeding Wolbachia-carrying mosquitoes, then releasing them into the wild. "The problem has always been figuring out systems that can work well in mosquitoes, and this seems like this is going to be one that's going to be great for that." He adds that the discovery may also work with Anopheles gambiae, the mosquito that carries malaria. The World Health Organization says there are 214 million cases of malaria each year. And the disease kills over 400,000 people a year worldwide. Because the mosquitoes are genetically engineered, Bechmann says he is concerned about legal barriers on the release of sterilized mosquitoes. He and other researchers are working to find money to pay for more experiments. I'm Anne Ball.
 1 2 下一页
分享到
添加到收藏

VOA慢速排行

  1. 1VOA词汇掌故:It Will Not Wash 行不通;不起作
  2. 1VOA词汇掌故:Circus 与马戏团相关的成语表达
  3. 1VOA词汇掌故:与苹果相关的美国习惯用语
  4. 1VOA词汇掌故:Dime 形容经济形势不好的几个美
  5. 1VOA英语词汇掌故:与背部、肩膀和胸部等身体
  6. 1VOA词汇掌故:All About Names 和人的名字有
  1. 1VOA词汇掌故:Circus 与马戏团相关的成语表达
  2. 1VOA词汇掌故:All About Names 和人的名字有
  3. 1VOA科学报道:Facebook点赞会泄露很多个人信
  4. 1Voa今日趋势:电影《黑豹》打破电影票房纪录
  5. 1VOA慢速:川普宣布对中国新征收数十亿美元进
  6. 1VOA慢速:法国政府新规 街头性骚扰最高罚款最
  1. 1VOA慢速:川普签署钢铝关税宣言 加拿大墨西哥
  2. 1VOA词汇掌故:All About Names 和人的名字有
  3. 1VOA慢速:亚马逊CEO贝佐斯成为全球首位千亿富
  4. 1VOA慢速:不丹国王 国民幸福比GDP更重要
  5. 1VOA慢速:5000万Facebook用户数据被滥用 批评
  6. 1VOA词汇掌故:Take the World by Storm 人名

鸿运国际手机版

百度360搜索搜狗搜索