课程咨询

托福考试网 托福资料下载 托福资讯 0元讲座 水平测试

托福考试练习
新东方在线 > TOEFL > 托福听力 > 正文
托福培训

扫码免费领资料

内含托福全科备考资料

更有免费水平测试及备考规划

托福培训

扫码关注掌握一手留学资讯

回复XDF免费水平测试

录播精讲 直播课HOT

托福听力练习-科学美国人60秒:蝙蝠对抗白鼻综合症

2017-03-10 17:02:00来源：科学美国人60秒

点击查看>>科学美国人60秒音频：蝙蝠对抗白鼻综合症

　　科学美国人60秒中英文翻译：蝙蝠对抗白鼻综合症

　　科学美国人60秒英文文本

　　This is Scientific American — 60-Second Science. I'm Jason Goldman.

　　The little brown bat was once abundant in the eastern U.S. But within the last 15 years, a fungus called Pseudogymnoascus destructans infiltrated a cave in upstate New York. This fungus causes what's called white-nose syndrome in bats.

　　The illness has now spread throughout North America, causing widespread bat die-offs. But recently, little brown bats in New York have stopped declining. In fact, their numbers are actually going back up.

　　"That was exciting, but we had no idea how these bats were persisting with the disease." Harvard University epidemiologist Kate Langwig.

　　"Little brown bats, during the fall swarm around hibernacula entrances. During that time period they're active, and they're feeding and fattening for winter, they also mate during that time period. Then they go into hibernation, and that's really when infection peaks. Winter is the time period in which white nose syndrome is happening to bats."

　　To understand how the New York bats were surviving, Langwig and her team compared them to bats from Illinois and Virginia, in colonies that are still experiencing the initial mass die-offs. They wanted to see whether the New York bats had simply found a way to tolerate the presence of the pathogen, or whether they'd actually developed resistance to the infection.

　　"So we found that when bats first return to hibernacula, they still become infected. Both in areas where the fungus has recently invaded as well as in areas where the fungus is established, bats become infected at the same time. And then in both places we see the fungus begin to grow and start to increase. However in areas where the disease has been for a number of years, what we find is that the fungus then reaches kind of a plateau."

　　So in New York, the disease ramps up starting in the early winter but then the fungus stops spreading. In Illinois and Virginia, it just keeps on growing.

　　"It suggests that the bats are somehow actually limiting the growth of the fungus on their skin."

　　Langwig still doesn't know how the bats are fighting off the disease. She also wants to find out why their resistance doesn't show up until so late in the winter. Does the response wait until it hits some threshold? Do the bats' immune systems just take longer to boot up during hibernation?

　　And last, of course, she wants to know what lessons bat researchers can learn from this population that might help them save other types of bats in other places.

　　"These results, that little brown bats have developed resistance, are really encouraging to think about. We could see bats abundant once again in the Northeast."

　　Thanks for listening for Scientific American — 60-Second Science Science. I'm Jason Goldman.

　　中文翻译请点击下一页

本文关键字: 托福听力 托福听力技巧

上一页 1 2 下一页

托福辅导

关注新东方在线托福

托福机经·Official题目练习

考前重点突破·听说读写海量资料

更多资料

关注新东方在线托福，
回复【XDF】获取大礼包

托福辅导
  • 1.打开手机微信【扫一扫】，识别上方二维码；
  • 2.点击【添加】，回复对应关键字领取学习资料。
更多>>
更多内容

免费获取托福备考大礼包

微信扫描下方二维码 立即领取

托福辅导
更多>>
更多公益讲座>>
更多>>
更多资料
托福TPO 托福听力练习 托福口语练习 托福阅读练习 托福写作练习
我要
反馈 返回
首页
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10