VOA慢速英语2009年-SCIENCE IN THE NEWS - Great Pacific Ocean

VOICE ONE:

This is the VOA Special English program SCIENCE IN THE NEWS. I'm Steve Ember.

VOICE TWO:

And I'm Doug Johnson. This week, we will tell about a drug treatment for stroke victims. We also will tell about a possible explanation for the mysterious disappearance¹ of bees. And, we will tell about a lot of plastic waste in the Pacific Ocean.

(MUSIC)

VOICE ONE:

Strokes are a major cause of death and disability. A stroke is a loss of blood flow in the brain. There are two kinds of strokes. An ischemic stroke happens when a blood vessel² in the brain gets blocked. A bleeding, or hemorrhagic, stroke happens when a blood vessel breaks.

People are more likely to die from a hemorrhagic stroke. But ischemic strokes are more common, and doctors may be able to treat them.

A drug called tissue plasminogen activator³, or tPA, can break up blood clots⁴. But experts generally advise against using the drug if more than three hours have passed after the first signs of a stroke.

VOICE TWO:
　
A team with the National Institutes of Health examines a stroke patient

There is a risk that giving a patient a strong blood thinner during a stroke can cause bleeding inside the brain. The longer the wait, experts say, the more likely that the risks of treatment will be too great.

But recent findings suggested that tPA may be effective in saving brain tissue even if three to four and a half hours have passed.

Some studies have failed to produce clear evidence to support treatment after three hours. But researchers reported recently that the evidence was stronger when they combined the results of the four major studies already done.

VOICE ONE:

The findings were published in the journal Stroke. The researchers said tPA improved the chances of a successful result by thirty-one percent and produced no change in the death rate.

Scientists from Belgium and Germany worked with Maarten Lansberg of the Stanford University School of Medicine in California. One of the scientists worked for a company that makes tPA for use in Europe. America's National Institutes of Health paid for the study.

VOICE TWO:

If you think someone is having a stroke, you should seek help immediately. The warning signs often appear suddenly. These include trouble walking, weakness especially on one side of the body, difficulty seeing and difficulty speaking.

Yet people who seem healthy can suffer a stroke without even knowing it. A study published last year involved about two thousand people with an average age of sixty-two. Brain imaging showed that nearly eleven percent of them had suffered what is known as a silent stroke.

The study found a link between silent strokes and a condition called atrial fibrillation. This is the most common cause of an unusual, or abnormal, heartbeat in older adults.

(MUSIC)

VOICE ONE:

Colony collapse⁶ disorder⁷ 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 disappearances⁸ of bees. Now, a new study suggests that several viruses may act together.

Scientists from the University of Illinois and the United States Department of Agriculture carried out the study. The scientists compared bees from affected⁹ colonies with those from healthy colonies. They were looking for differences in gene⁵ expression in the guts¹⁰ of the bees.

VOICE TWO:

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 paralysis¹¹ virus and deformed¹² wing virus.

Extremely small insects are likely involved in spreading the viruses. Varroa mites¹³ 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 genes¹⁴ to produce proteins needed to fight infections.

VOICE ONE:

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 seize control of the ribosome in cells. Ribosomes are structures in which proteins are made.

The professor says ribosome is important to the survival of any organism. If it is compromised, then the bees could not defend themselves against pesticide¹⁵ products, fungal infections, bacteria or poor nutrition. These have all been identified as possible causes of the collapse disorder.

(MUSIC)

VOICE TWO:

Imagine a mass of floating waste two times the state of Texas. Texas has a land area of more than six hundred and seventy-eight thousand square kilometers. So it might be difficult to imagine anything twice as big.

The waste includes bags, bottles and containers. Plastic products of all kinds -- even shoes. There also are lots and lots of extremely small pieces of plastic.

All together, this mass of waste floating in the North Pacific Ocean is known as the Great Pacific Ocean Garbage Patch. It weighs about three million, five hundred thousand tons.

VOICE ONE:
　
A mass of waste found off the coast of Hawaii in 2002

The eastern part of the Great Pacific Ocean Garbage Patch is about one thousand six hundred kilometers west of California. The western part is west of the Hawaiian Islands and east of Japan. The two patches of waste are connected together in the shape of a dog bone -- a really big bone about nine thousand kilometers long.

The waters surrounding the Great Pacific Ocean Garbage Patch are known as the North Pacific Gyre. The area has been described as a kind of oceanic desert, with light winds and slow moving water currents. Slow enough that garbage from all over the world collects there.

Experts say the garbage gets trapped in the currents for years before being pushed out. Some of the trash finds its way to coastal¹⁶ areas around the world.

VOICE TWO:

In recent years, there have been growing concerns about the floating garbage and its effect on sea creatures and human health. America's Environmental Protection Agency estimates that about one hundred thousand sea animals die each year as a result of the plastic waste. An estimated one million sea birds are also affected.

Scientists say thousands of the animals get trapped in the floating waste, resulting in death or injury. Even more die from a lack of food or water after swallowing pieces of plastic. The plastic can block air passages. The trash can also make the animal feel full, lessening¹⁷ its desire to eat or drink.

The floating garbage also can have harmful effects on people. There is an increased threat of infection and disease from polluted waste, and from eating fish that swallowed waste. Divers¹⁸ can also get trapped in the plastic, and it can get caught up in boating equipment. The plastic also releases chemicals into the water. Some of the chemicals are harmful to both humans and animals.

VOICE ONE:

The existence of the North Pacific Garbage Patch first gained public attention in nineteen ninety-seven. That was when racing¹⁹ boat captain and oceanographer Charles Moore and his crew sailed into the garbage while returning from a racing event.

Five years earlier, another oceanographer learned of the trash after a shipment of rubber duckies got lost at sea. Many of those toys are now part of the Great Pacific Ocean Garbage Patch.

Charles Moore and his team at the Algalita Marine²⁰ Research Foundation have spent ten years studying plastic waste and testing water from the ocean. Their studies found up six times more plastic in the water than zooplankton, the small organisms normally found floating near the ocean's surface. They have also found small pieces of plastic inside the stomachs of fish like mahi-mahi.

VOICE TWO:

Last month, a team from the University of California at San Diego became the latest group to travel to the Great Pacific Ocean Garbage Patch. The team of students and research volunteers set off on a three-week boat trip to examine the area.

They were shocked by the amount of waste they saw. They gathered hundreds of sea creatures and water samples to measure the garbage patch's effect on ocean environment. There were small pieces of plastic in every sample.

(MUSIC)

VOICE ONE:

This SCIENCE IN THE NEWS was written by June Simms and Jerilyn Watson. Our producer was Caty Weaver²¹. Transcripts²², MP3s and podcasts of our programs are at voaspecialenglish.com. I'm Steve Ember.

VOICE TWO:

And I'm Doug Johnson. Listen again next week for more news about science in Special English on the Voice of America.

1 disappearance   

n.消失，消散，失踪

参考例句：

• He was hard put to it to explain her disappearance.他难以说明她为什么不见了。
• Her disappearance gave rise to the wildest rumours.她失踪一事引起了各种流言蜚语。

2 vessel   

n.船舶；容器，器皿；管，导管，血管

参考例句：

• The vessel is fully loaded with cargo for Shanghai.这艘船满载货物驶往上海。
• You should put the water into a vessel.你应该把水装入容器中。

3 activator   

催化剂，触媒剂

参考例句：

• In a separate archive is the official localization and universal activator. 在单独的存档是正式的本地化和普遍激活。
• From a certain angle, affections are the activator to carve out successfully. 从某种角度看，爱心是创业成功的“催化剂”。

4 clots   

n.凝块( clot的名词复数 )；血块；蠢人；傻瓜v.凝固( clot的第三人称单数 )

参考例句：

• When you cut yourself, blood clots and forms a scab. 你割破了，血会凝固、结痂。 来自《简明英汉词典》
• Milk clots when it turns sour. 奶变酸就凝块。 来自《现代英汉综合大词典》

5 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

6 collapse   

vi.累倒；昏倒；倒塌；塌陷

参考例句：

• The country's economy is on the verge of collapse.国家的经济已到了崩溃的边缘。
• The engineer made a complete diagnosis of the bridge's collapse.工程师对桥的倒塌做了一次彻底的调查分析。

7 disorder   

n.紊乱，混乱；骚动，骚乱；疾病，失调

参考例句：

• When returning back,he discovered the room to be in disorder.回家后，他发现屋子里乱七八糟。
• It contained a vast number of letters in great disorder.里面七零八落地装着许多信件。

8 disappearances   

n.消失( disappearance的名词复数 )；丢失；失踪；失踪案

参考例句：

• Most disappearances are the result of the terrorist activity. 大多数的失踪案都是恐怖分子造成的。 来自辞典例句
• The espionage, the betrayals, the arrests, the tortures, the executions, the disappearances will never cease. 间谍活动、叛党卖国、逮捕拷打、处决灭迹，这种事情永远不会完。 来自英汉文学

9 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

10 guts   

v.狼吞虎咽，贪婪地吃，飞碟游戏（比赛双方每组5人，相距15码，互相掷接飞碟）；毁坏（建筑物等）的内部( gut的第三人称单数 )；取出…的内脏n.勇气( gut的名词复数 )；内脏；消化道的下段；肠

参考例句：

• I'll only cook fish if the guts have been removed. 鱼若已收拾干净，我只需烧一下即可。
• Barbara hasn't got the guts to leave her mother. 巴巴拉没有勇气离开她妈妈。 来自《简明英汉词典》

11 paralysis   

n.麻痹(症)；瘫痪(症)

参考例句：

• The paralysis affects his right leg and he can only walk with difficulty.他右腿瘫痪步履维艰。
• The paralysis affects his right leg and he can only walk with difficulty.他右腿瘫痪步履维艰。

12 deformed   

adj.畸形的；变形的；丑的，破相了的

参考例句：

• He was born with a deformed right leg.他出生时右腿畸形。
• His body was deformed by leprosy.他的身体因为麻风病变形了。

13 mites   

n.（尤指令人怜悯的）小孩( mite的名词复数 )；一点点；一文钱；螨

参考例句：

• The only discovered animals are water bears, mites, microscopic rotifers. 能够发现的动物只有海蜘蛛、螨和微小的轮虫。 来自辞典例句
• Mites are frequently found on eggs. 螨会经常出现在蛋上。 来自辞典例句

14 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪

15 pesticide   

n.杀虫剂，农药

参考例句：

• The pesticide was spread over the vegetable plot.菜田里撒上了农药。
• This pesticide is diluted with water and applied directly to the fields.这种杀虫剂用水稀释后直接施用在田里。

16 coastal   

adj.海岸的，沿海的，沿岸的

参考例句：

• The ocean waves are slowly eating away the coastal rocks.大海的波浪慢慢地侵蚀着岸边的岩石。
• This country will fortify the coastal areas.该国将加强沿海地区的防御。

17 lessening   

减轻，减少，变小

参考例句：

• So however much he earned, she spent it, her demands growing and lessening with his income. 祥子挣多少，她花多少，她的要求随着他的钱涨落。 来自汉英文学 - 骆驼祥子
• The talks have resulted in a lessening of suspicion. 谈话消减了彼此的怀疑。

18 divers   

adj.不同的；种种的

参考例句：

• He chose divers of them,who were asked to accompany him.他选择他们当中的几个人，要他们和他作伴。
• Two divers work together while a standby diver remains on the surface.两名潜水员协同工作，同时有一名候补潜水员留在水面上。

19 racing   

n.竞赛，赛马；adj.竞赛用的，赛马用的

参考例句：

• I was watching the racing on television last night.昨晚我在电视上看赛马。
• The two racing drivers fenced for a chance to gain the lead.两个赛车手伺机竞相领先。

20 marine   

adj.海的；海生的；航海的；海事的；n.水兵

参考例句：

• Marine creatures are those which live in the sea. 海洋生物是生存在海里的生物。
• When the war broke out,he volunteered for the Marine Corps.战争爆发时，他自愿参加了海军陆战队。

21 weaver   

n.织布工；编织者

参考例句：

• She was a fast weaver and the cloth was very good.她织布织得很快，而且布的质量很好。
• The eager weaver did not notice my confusion.热心的纺织工人没有注意到我的狼狈相。

22 transcripts   

n.抄本（ transcript的名词复数 ）；转写本；文字本；副本

参考例句：

• Like mRNA, both tRNA and rRNA are transcripts of chromosomal DNA. tRNA及rRNA同mRNA一样，都是染色体DNA的转录产物。 来自辞典例句
• You can't take the transfer students'exam without your transcripts. 没有成绩证明书，你就不能参加转学考试。 来自辞典例句