会员:密码:注册会员忘记密码?网站帮助我浏览过的资料
设为首页加入收藏夹加入QQ书签论坛
首页每天学英语新概念走遍美国音标词汇语法研究生大学中学小学演讲考试听力有声圣经VOA儿童商务

您所在的位置: 大耳朵首页 > 听力资料 > 在线视听资料 >...> 2006年VOA慢速英语 > 2月份 > 正文

站内搜索:

大耳朵背单词,让我们时刻进步:
overturn/[͵əuvə'tə:n]/v.推翻决定、结果等;翻倒,倾覆,使..翻倒
2006年VOA慢速英语special200602070045
SCIENCE IN THE NEWS - U.S. Seeks to Cut Levels of Chemical Used for Teflon, Other Non-Stick ProductsBy Caty Weaver, Brianna Blake and Jerilyn Watson

Broadcast: Tuesday, February 07, 2006

(MUSIC)

VOICE ONE:

This is SCIENCE IN THE NEWS in VOA Special English. I'm Bob Doughty.

VOICE TWO:

And I'm Pat Bodnar. This week: Action on health concerns over a chemical used to make Teflon and other products ...

VOICE ONE:

What happens when scientists go fishing for the world's smallest fish ...

VOICE TWO:

And a genetic study of modern cats follows their steps back in time.




(MUSIC)

VOICE ONE:

We begin with new developments in a story we first reported in two thousand four. It involves concern about possible health risks from a chemical used to make Teflon and other non-stick products.

The chemical is known as PFOA, perfluorooctanoic acid. Over the years, PFOA has become widespread in the environment. Many people have small amounts of it in their blood. It has also been found in wildlife, even in polar bears in the Arctic.

On January twenty-fifth, the United States Environmental Protection Agency sent letters to eight manufacturing companies. The E.P.A. invited them to reduce their releases of the chemical into the environment. Another goal is to reduce the presence of PFOA in products.

The aim is to reduce both levels by ninety-five percent by two thousand ten. Companies are supposed to work toward cutting the levels completely by two thousand fifteen.

The eight companies are all in the United States. They are expected to honor the request.

DuPont, the maker of Teflon, has agreed to join the program. But in a statement the company says, Products made with or using DuPont materials are safe.

VOICE TWO:

Non-stick surfaces keep food from sticking to pots and pans. They help clothing stay clean and dry. They have industrial and even medical uses.

Research on PFOA continues, but the concerns are that it could be linked to birth disorders and other conditions. Last week, an independent scientific committee advised the E.P.A. to consider the chemical a likely cause of cancer. DuPont disagreed.

The plan by the Environmental Protection Agency calls for yearly public reports about the progress made toward reaching the goals. Methods for measuring PFOA reductions must also be developed.

In December, the agency announced a sixteen and one-half million dollar settlement with DuPont involving PFOA. Officials found that DuPont violated federal law on reporting chemical risk information.

VOICE ONE:

Perfluorooctanoic acid is a processing aid used by different companies to make high-performance plastics. Some of these are sold under the Teflon name. DuPont says studies done under normal cooking conditions have not found any release of PFOA from Teflon products. The company says, in its words: Cookware coated with Teflon has been safely used for more than forty years.

DuPont says it has also agreed to cut the amount of PFOA that is present in its soil, stain and grease repellant products. The chemical is not used in those products, but is created when they are manufactured.

(MUSIC)

VOICE TWO:

You are listening to SCIENCE IN THE NEWS in VOA Special English, from Washington.

Most people who hope to catch a record-size fish hope to catch a really big one. Scientists compete to see who can claim the world's smallest fish.

A report published last month tells of a newly discovered kind of fish in Southeast Asia. It lives in blackwater wetlands. Scientists said it appeared to be the smallest fish known, as well as the smallest vertebrate. Vertebrates are animals with a backbone.

VOICE ONE:

Experts discovered it on the Indonesian island of Sumatra. And they needed a microscope to measure it.

The smallest fully grown female they measured was just seven-point-nine millimeters. The longest was ten-point-three millimeters. Scientists say the new fish is a member of the carp family. It has a body so thin, light can pass through it.

Maurice Kottelat from the Raffles Museum of Biodiversity Research, National University of Singapore, led the study team. The Royal Society in London published the findings.

In the competition to find small fish, a few tenths of a millimeter or even a single tenth of a millimeter can make a big difference. And some scientists argue that smallest can also mean lightest.

VOICE TWO:

The new report did not include any weights. But one interesting discovery about the new fish is an area of hardened skin on the underside of the male. The scientists say no other fish is known to have this. They believe it is used to hold the female during mating.

The fish is also unusual in that its brain is not completely covered by protective bone, like most vertebrates.

The scientists say development and agriculture threaten the Indonesian wetlands that are home to the fish. Several populations of fish are reported to have disappeared already. So the researchers hope to learn as much as possible before this little fish could be lost.

Examples were first collected in nineteen ninety-six. But scientists only recently recognized the fish as a new species. They call it Paedocypris progenetica, a long scientific name.

VOICE ONE:

Now this fish story has gotten longer since the report appeared late last month. On January twenty-seventh the University of Washington in Seattle put out a news release. It said the scientists with the seven-point-nine millimeter fish have failed to make note of work published last fall.

In that work, a University of Washington professor, Ted Pietsch, described some fully grown male anglerfish. He reported that the shortest one measured six-point-two millimeters. It was collected in the Philippines. It was attached to the back of a forty-six-millimeter long female anglerfish. That is how they mate, the news release explained.

Professor Pietsch tells us that he is friends with the scientists in Singapore, and they told him that they just missed his report. The Ichthyological Society of Japan published it. Ichthyology is the study of fishes.

Anglerfish live deep in oceans around the world. But those fish on Sumatra live in freshwater. So perhaps they might be called the world's smallest freshwater fish ... at least for now.

(MUSIC)

VOICE TWO:

When you find a fish, you might also find a cat hoping for a tasty meal.

Thirty-seven kinds of cats are alive today. They include big cats like lions and tigers. They also include the small cats that share their homes with people.

A study of modern cats shows they developed from animals that lived in Asia almost eleven million years ago. The newly published research shows how new kinds of cats developed as they spread around the world.

Warren Johnson and Stephen O'Brien led an international team that did the study. The two scientists work for the National Cancer Institute at its Laboratory of Genomic Diversity in Frederick, Maryland. Science magazine published the results.

VOICE ONE:

The researchers suggest that cats became world explorers because of the rise and fall of sea levels. Land bridges appeared as water levels fell. The researchers say ancient cats used the Bering land bridge to travel from East Asia to North America. They are also said to have crossed the Panamanian land bridge that connected North and South America.

There are few remains of old cat bones. And it is difficult to identify differences between these fossils. So it has been hard for scientists to understand the cat family. But the new study of cat genetics might even help researchers who study human diseases.

The researchers examined genetic material from the sex chromosomes of all thirty-seven kinds of cats. They also studied material from energy-producing mitochondria in cells.

Evidence of genetic changes over time helped the scientists produce a history of the cat family. Dating of the fossils assisted in the placement of cats into this genetic family tree.

VOICE TWO:

The researchers placed every kind of cat into one of eight lines of ancestry. They say cats moved between continents at least ten times.

Low ocean levels let the first modern cats spread from Asia into Africa. The spread into North America produced other kinds of cats. The researchers say the most recent of the ancestry lines started about six million years ago in Asia and Africa. They believe it produced the cats of today.

And today cats can be found on all continents except Antarctica.

(MUSIC)

VOICE ONE:

SCIENCE IN THE NEWS was written by Caty Weaver, Brianna Blake and Jerilyn Watson. Cynthia Kirk was our producer. I'm Bob Doughty.

VOICE TWO:

And I'm Pat Bodnar. Internet users can read and listen to our programs at www.unsv.com. Join us again next week for more news about science in Special English on the Voice of America.
共有0人向本资料提供了听力原文,其中被采用了0篇,当前有0篇待审批,有0篇未被采用! 查看明细>>
如果您有更好的听力原文,欢迎提供给大耳朵,如果被采用,您将获得20到100金币的奖励!
Google  热门:英语培训学校英语口语英语翻译英语学习
已有0位对此听力感兴趣的网友发表了看法
非常好 很好 一般 不好 很差
* 如果因您不良评论或重复评论导致评论被删,您将会被扣掉一定数额的金币。
* 您必须遵守《全国人大常委会关于维护互联网安全的决定》及中华人民共和国其他有关法律法规。
* 承担一切因您的行为而直接或间接导致的民事或刑事法律责任。
* 您发表的文章仅代表个人观点,与大耳朵网站无关。
* 大耳朵评论管理人员有权保留或删除其管辖评论中的任意内容。
* 您在大耳朵网评论系统发表的作品,大耳朵网有权在网站内转载或引用。
* 参与本评论即表明您已经阅读并接受上述条款。
2月份
高瞻远瞩
放眼全球
Google
热门:英语培训学校 英语口语 英语翻译 英语学习
图片新闻更多
推荐资源
经典学习方法更多>>
听力资料目录导航
听力测试 英语词汇 英语口语 考试英语 品牌英语 大学教材 其他教材 商务英语 广播英语 儿童英语
历年中考听力
初中中考模拟
历年高考听力
高考听力模拟
历年四级听力
历年六级听力
四级听力模拟
小学  初中
高中  四级
六级  考研
托福  GRE
星火记忆单词
用Mp3背单词
刘毅词汇记忆
情景英语口语
4+1听力口语
出国实用会话
英语口语8000句
新东方900句
美语听力与发音
ABC到流利口语
口译考试
剑桥考试
中高考考试
大学四六级考试
研究生考试
公共英语考试
英语专业考试
新概念 六人行
赖世雄 许国璋
走遍美国 越狱
疯狂英语 沛沛
语法讲座 动感
大山英语 探索
千万别学英语
大学英语听力
大学英语精读
全新版 21世纪
新视野 实用综
大学体验 新编
成人自考 step
Listen this way
广州版小学英语
广州版初中英语
剑桥少儿英语
朗文3L看听学
Goforit新目标
高中英语课本
进阶听说教程
商务英语300句
VOA商务英语
商业英语视频
中级商务英语
初级剑桥证书
新编剑桥英语
剑桥英语精华版
2007年VOA慢速
VOA中级美语
美国习惯用语
VOA流行美语
澳广播英语讲座
在线大学课堂
VOA视频节目
宝宝ABC
棒棒英语
哈哈美语
LittleFox儿歌
英语儿童故事
380英语小故事
1035个英语单词
updated Sat Jul 26, 2008
免责声明:本站只提供资源播放平台,如果站内部分资源侵犯您的权益,请您告知,站长会立即处理。
Copyright © 2003-2008 大耳朵英语  鲁ICP备05010808号