VOA慢速英语2009年-SCIENCE IN THE NEWS - Cutting Calories: Mo

VOICE ONE:

This is SCIENCE IN THE NEWS in VOA Special English. I'm Bob Doughty¹.

VOICE TWO:

And I'm Barbara Klein. This week, we tell about how thin monkeys live longer than fat ones, how aspirin² can help colon³ cancer patients and some new information about Tyrannosaurus rex.

(MUSIC)

VOICE ONE:
　
A recent study found that eating less may extend the life of rhesus monkeys

A study of monkeys over a twenty-year period suggests that eating less may extend life and prevent disease. American researchers said they believe their findings could apply to people as well. Their study was published in the journal Science.

Richard Weindruch of the University of Wisconsin in Madison and his team did the research. They tested the effects of calorie restriction⁴ in seventy-six rhesus monkeys over twenty years.

Half of the monkeys were permitted to eat as much as they wanted. The other half ate a controlled diet. They were fed two-thirds of the calories they would otherwise choose to eat. These monkeys were given vitamins and minerals to prevent malnutrition⁵.

VOICE TWO:

The researchers found that thirty-seven percent of the monkeys that ate as much as they wanted had died of causes related to aging after twenty years. In comparison, only thirteen percent of the monkeys on restricted diets had died.

On average, rhesus monkeys live about twenty-seven years in captivity⁶, that is, when they live with humans and not in the wild. Mister Weindruch says researchers do not know why reducing calories increases the length of life. But they believe there is a helpful change in the way the body processes energy in the monkeys that eat fewer calories.

Extended life was not the only observable difference between the two groups. The monkeys that ate less had half the amount of heart disease and cancer. They also had no cases of the disease diabetes⁷. Richard Weindruch explains.

RICHARD WEINDRUCH: "Our data show that there is about a three-fold higher risk of developing a disease of aging in those animals fed the normal diet as opposed to those that have been on caloric restriction since they were adults."

VOICE ONE:

Mister Weindruch says not only is life extended in the monkeys that eat less, but their quality of life is also improved. He noted⁸ another surprising observation in the monkeys on a restricted diet. There was a delay in muscle loss and brain shrinkage that lead to mental problems linked to aging.

In addition, there is also a difference in the appearance of calorie-restricted monkeys and those on a normal diet. The monkeys that ate fewer calories look younger and healthier than fatter monkeys on an unrestricted diet.

VOICE TWO:

The study was paid for by the United States National Institute on Aging. Some critics say more research is needed to prove that calorie restriction extends life in monkeys. Mister Weindruch says his study is not complete and that his team will continue to observe the remaining monkeys throughout their lives.

Scientists first studied the effects of calorie restriction on aging in the nineteen thirties. Since then, similar studies have shown life-extending effects of reduced diets on rodents⁹, yeast¹⁰ and worms. Scientists are currently studying the effects of restricted diets on people. However, this is more difficult because it is harder to control the diets of people and because they live longer than other animals.

(MUSIC)

VOICE ONE:

People since ancient times have used aspirin-like medicines to fight pain and reduce high body temperature. Modern research has found other uses for aspirin. The drug acts as a blood thinner. It can help blood flow past a blockage¹¹ in an artery¹². Blockages¹³ can cause heart attacks or strokes. As a result, patients at risk of blockages might be advised by their doctors to take a low-strength aspirin every day. And research continues. A new study has shown that aspirin can improve survival in colon cancer patients.

VOICE TWO:

The study involved about one thousand three hundred patients with colorectal cancer. The cancer had not spread to other parts of the body yet. The study compared patients who took three hundred twenty-five milligrams of aspirin at least two times a week with those who did not use aspirin.

The study found that the aspirin users had an almost thirty percent lower risk of dying from their cancer. That was during an average of eleven years after the cancer was discovered.

Andrew Chan of Harvard Medical School and Massachusetts General Hospital led the study. Doctor Chan says the effects appeared especially strong among patients with tumors expressing an enzyme¹⁴ called COX-2. Two-thirds of colorectal cancers produce that chemical. Doctor Chan thinks the aspirin works by blocking it.

The study appeared in the Journal of the American Medical Association. It was an observational study. In a controlled study, some patients would have taken aspirin. Others would have received a placebo¹⁵ -- sugar pills -- for comparison.

VOICE ONE:

Last year, Doctor Chan reported that a long-term study of almost fifty thousand men showed that aspirin can help prevent colon cancer. But the effects required at least six years of regular use. And the greatest risk reductions were in those who took more than fourteen aspirins per week.

But the researchers warned that the dangers from such large amounts of aspirin should be carefully considered. Aspirin is a kind of nonsteroidal anti-inflammatory drug, or NSAID. The earlier study found comparable reductions from the use of other NSAIDs, but not from the use of acetaminophen.

All of these drugs have their uses but they also have risks. Aspirin can cause bleeding in the stomach, the intestines¹⁶ and the brain. People who might want to consider taking aspirin as a preventative measure should first talk to a doctor.

(MUSIC)

VOICE TWO:
　
A Tyrannosaurus rex skeleton named "Jane" at the Burpee Museum of Natural History in Rockford, Illinois

There is new information about Tyrannosaurus rex, the most widely recognized dinosaur¹⁷ and a favorite among children. Many children's books show T.rex fighting bloody¹⁸ battles with other huge dinosaurs¹⁹.

But now it seems that T.rex may not have been as fierce as scientists once believed.

"Tyrannosaurus" means "tyrant²⁰ lizard²¹" and "rex" is Latin for "king." The Tyrannosaurus lived in North America during the late Cretaceous Period. The huge animals died out about sixty-five million years ago.

T.rex was one of the largest meat-eating dinosaurs that ever lived. It stood four to six meters tall, was about twelve meters long, and weighed up to seven tons. Its huge head was one and a half meters long. It also had sharp, bone-crushing teeth. The animal was believed to be a fierce predator²² that ate other dinosaurs.

VOICE ONE:

Scientists believed the Tyrannosaurus ate even larger plant-eating dinosaurs. And, they believed T.rex could eat up to two hundred thirty kilograms of meat in one bite. But new research suggests that the deadly dinos may not have been as fierce as earlier believed.

Oliver Rauhut is a paleontologist at Ludwig Maximilians University of Munich in Germany. David Hone is a paleontologist at the Institute of Vertebrate Paleontology and Paleoanthropology of China in Beijing.

The two scientists have concluded from fossil records that giant meat-eating dinosaurs like the Tyrannosaurus rex mainly ate young dinosaurs. Fossil records of the stomach contents of the larger dinosaurs suggest they swallowed these young dinosaurs whole.

VOICE TWO:

The scientists say this belief is further supported by the fact that past discoveries from dinosaur areas show they contained large numbers of dinosaur eggs. This should have resulted in a large number of baby dinosaurs. But Mister Rauhut says fossil records show that this is not the case. He says young dinosaur fossils are extremely rare, a possible sign that many of them had been eaten by attackers.

Mister Hone says the records suggest that Tyrannosaurus rex was like many other predators²³. It attacked young, old or sick animals that were not much of a threat.

There are some signs of conflict between T-rex and other large dinosaurs. But, Mister Hone says the records seem to suggest that those were few. The scientists say they hope more fossils will be found that support their beliefs.

(MUSIC)

VOICE ONE:

This SCIENCE IN THE NEWS was written by Caty Weaver²⁴, June Simms and Brianna Blake who was also the producer. I'm Bob Doughty.

VOICE TWO:

And I'm Barbara Klein. For transcripts²⁵, MP3s and podcasts of our shows, go to our Web site, voaspecialenglish.com. Listen again next week for more news about science in Special English on the Voice of America.

1 doughty   

adj.勇猛的，坚强的

参考例句：

• Most of successful men have the characteristics of contumacy and doughty.绝大多数成功人士都有共同的特质：脾气倔强，性格刚强。
• The doughty old man battled his illness with fierce determination.坚强的老人用巨大毅力与疾病作斗争。

2 aspirin   

n.阿司匹林

参考例句：

• The aspirin seems to quiet the headache.阿司匹林似乎使头痛减轻了。
• She went into a chemist's and bought some aspirin.她进了一家药店，买了些阿司匹林。

3 colon   

n.冒号，结肠，直肠

参考例句：

• Here,too,the colon must be followed by a dash.这里也是一样，应当在冒号后加破折号。
• The colon is the locus of a large concentration of bacteria.结肠是大浓度的细菌所在地。

4 restriction   

n.限制，约束

参考例句：

• The park is open to the public without restriction.这个公园对公众开放，没有任何限制。
• The 30 mph speed restriction applies in all built-up areas.每小时限速30英里适用于所有建筑物聚集区。

5 malnutrition   

n.营养不良

参考例句：

• In Africa, there are a lot of children suffering from severe malnutrition.在非洲有大批严重营养不良的孩子。
• It is a classic case of malnutrition. 这是营养不良的典型病例。

6 captivity   

n.囚禁；被俘；束缚

参考例句：

• A zoo is a place where live animals are kept in captivity for the public to see.动物园是圈养动物以供公众观看的场所。
• He was held in captivity for three years.他被囚禁叁年。

7 diabetes   

n.糖尿病

参考例句：

• In case of diabetes, physicians advise against the use of sugar.对于糖尿病患者，医生告诫他们不要吃糖。
• Diabetes is caused by a fault in the insulin production of the body.糖尿病是由体內胰岛素分泌失调引起的。

8 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

9 rodents   

n.啮齿目动物( rodent的名词复数 )

参考例句：

• Rodents carry diseases and are generally regarded as pests. 啮齿目动物传播疾病，常被当作害虫对待。 来自《简明英汉词典》
• Some wild rodents in Africa also harbor the virus. 在非洲，有些野生啮齿动物也是储毒者。 来自辞典例句

10 yeast   

n.酵母；酵母片；泡沫；v.发酵；起泡沫

参考例句：

• Yeast can be used in making beer and bread.酵母可用于酿啤酒和发面包。
• The yeast began to work.酵母开始发酵。

11 blockage   

n.障碍物；封锁

参考例句：

• The logical treatment is to remove this blockage.合理的治疗方法就是清除堵塞物。
• If the blockage worked,they could retreat with dignity.如果封锁发生作用，他们可以体面地撤退。

12 artery   

n.干线，要道；动脉

参考例句：

• We couldn't feel the changes in the blood pressure within the artery.我们无法感觉到动脉血管内血压的变化。
• The aorta is the largest artery in the body.主动脉是人体中的最大动脉。

13 blockages   

n.堵塞物( blockage的名词复数 )；堵塞，阻塞

参考例句：

• The storms could increase the risks posed by river blockages. 暴风雨会增加因河道堵塞所造成的危险。 来自互联网
• An angiogram shows the location and severity of blockages in blood vessels. 冠状动脉造影能够显示血管内的阻塞位置以及阻塞的严重程度。 来自互联网

14 enzyme   

n.酵素，酶

参考例句：

• Above a certain temperature,the enzyme molecule will become unfolded.超过一定温度，酶分子将会展开。
• An enzyme that dissolves the fibrin of blood clots.能溶解血凝块中的纤维的酶。

15 placebo   

n.安慰剂；宽慰话

参考例句：

• The placebo has been found to work with a lot of different cases.人们已发现安慰剂能在很多不同的病例中发挥作用。
• The placebo effect refers to all the observable behaviors caused by placebo.安慰剂效应是指由安慰剂所引起的可观察的行为。

16 intestines   

n.肠( intestine的名词复数 )

参考例句：

• Perhaps the most serious problems occur in the stomach and intestines. 最严重的问题或许出现在胃和肠里。 来自辞典例句
• The traps of carnivorous plants function a little like the stomachs and small intestines of animals. 食肉植物的捕蝇器起着动物的胃和小肠的作用。 来自辞典例句

17 dinosaur   

n.恐龙

参考例句：

• Are you trying to tell me that David was attacked by a dinosaur?你是想要告诉我大卫被一支恐龙所攻击？
• He stared at the faithful miniature of the dinosaur.他凝视著精确的恐龙缩小模型。

18 bloody   

adj.非常的的；流血的；残忍的；adv.很；vt.血染

参考例句：

• He got a bloody nose in the fight.他在打斗中被打得鼻子流血。
• He is a bloody fool.他是一个十足的笨蛋。

19 dinosaurs   

n.恐龙( dinosaur的名词复数 )；守旧落伍的人，过时落后的东西

参考例句：

• The brontosaurus was one of the largest of all dinosaurs. 雷龙是所有恐龙中最大的一种。 来自《简明英汉词典》
• Dinosaurs have been extinct for millions of years. 恐龙绝种已有几百万年了。 来自《简明英汉词典》

20 tyrant   

n.暴君，专制的君主，残暴的人

参考例句：

• The country was ruled by a despotic tyrant.该国处在一个专制暴君的统治之下。
• The tyrant was deaf to the entreaties of the slaves.暴君听不到奴隶们的哀鸣。

21 lizard   

n.蜥蜴，壁虎

参考例句：

• A chameleon is a kind of lizard.变色龙是一种蜥蜴。
• The lizard darted out its tongue at the insect.蜥蜴伸出舌头去吃小昆虫。

22 predator   

n.捕食其它动物的动物；捕食者

参考例句：

• The final part of this chapter was devoted to a brief summary of predator species.本章最后部分简要总结了食肉动物。
• Komodo dragon is the largest living lizard and a fearsome predator.科摩多龙是目前存在的最大蜥蜴，它是一种令人恐惧的捕食性动物。

23 predators   

n.食肉动物( predator的名词复数 )；奴役他人者（尤指在财务或性关系方面）

参考例句：

• birds and their earthbound predators 鸟和地面上捕食它们的动物
• The eyes of predators are highly sensitive to the slightest movement. 捕食性动物的眼睛能感觉到最细小的动静。 来自《简明英汉词典》

24 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。

25 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