在线英语听力室

VOA慢速英语2009年-Agriculture Report - New Findings About Di

时间:2009-09-28 06:06:17

搜索关注在线英语听力室公众号:tingroom,领取免费英语资料大礼包。

(单词翻译)

This is the VOA Special English Agriculture Report.

Colony collapse1 disorder2 first struck honey bees in the United States in late two thousand six. Over the next two years, beekeepers lost more than one-third of their honey bees.

Scientists in the United States and other countries have been working to explain the mysterious disappearances3 of bees. Now, a new study suggests that several viruses may act together.
 
A couple in Wilmington, Ohio, look over the honeycombs in their beehives last month

Scientists from the University of Illinois and the United States Department of Agriculture did the study. Their report appeared in the Proceedings4 of the National Academy of Sciences.

The team compared bees from affected5 colonies with those from healthy colonies. They were looking for differences in gene6 expression in the guts7 of the bees.

The scientists found that the affected bees had a number of viruses from a group called picorna-like viruses. The infections observed in the bees included Israeli acute paralysis8 virus and deformed9 wing virus.

Tiny insects likely play a big part in spreading the viruses. Varroa mites10 have been causing serious problems in bee colonies in the United States since the late nineteen eighties. These mites carry picorna-like viruses.

The viruses appear to harm the bees' ability to use their genetic11 material to produce proteins needed to fight infections. Researcher Reed Johnson, now at the University of Nebraska-Lincoln, says the study suggests that the damaged proteins are unable to respond effectively when attacked.

University of Illinois Professor May Berenbaum says it appears that bees could deal with one or two viruses at the same time, but not three or four.

She says the picorna-like viruses "hijack12" the ribosome in cells. Ribosomes are structures in which proteins are made. As a result the ribosome produces only viral proteins.

The professor says ribosome is central to the survival of any organism. If it is compromised, then the bees could not defend themselves against pesticides13 or fungal infections or bacteria or poor nutrition.

These have all been identified as possible causes of the collapse disorder. Spanish researchers, for example, recently said they suspected a parasitic14 fungus15 which has been found among affected bees in Spain.

Bees add billions of dollars in value to many crops worldwide. For now, beekeepers have been doing their best to try to protect their colonies.

And that's the VOA Special English Agriculture Report, written by Jerilyn Watson. I'm Faith Lapidus.


分享到:

Error Warning!

出错了

Error page: /mobile/index.php?aid=81996&mid=3
Error infos: Got error 28 from storage engine
Error sql: select `l`.`tag`,`l`.`index`,`l`.`level_id`,`b`.`id`,`b`.`word`,`b`.`spell`,`b`.`explain`,`b`.`sentence`,`b`.`src` from `new_wordtaglist` `l` left join `new_word_base` `b` on `l`.`tag`=`b`.`word` where `l`.`arc_id`='81996' and `l`.`level_id`>='' group by `b`.`word` order by `l`.`index` asc

本文本内容来源于互联网抓取和网友提交,仅供参考,部分栏目没有内容,如果您有更合适的内容,欢迎 点击提交 分享给大家。