VOA慢速英语2003年-发展与科学 America's Tree Defi

Broadcast: October 7, 2003

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VOICE ONE:

I'm Bob Doughty 1 with Sarah Long, and this is SCIENCE IN THE NEWS, from VOA Special English.

VOICE TWO:

This week -- new polio cases in Africa ... a tree deficit 2 in American cities ... and, later, monkeys play fair ... and the idea of "cough C-P-R."

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VOICE ONE:

Cases of 1)polio have been reported in three West African countries that had been free of the disease 3. The World Health Organization says cases have been reported in 2)Ghana, 3)Togo and 4)Burkina Faso.

Polio is also spreading again in Nigeria. Doctors with the W-H-O say the virus has spread to the city of 5)Lagos. Less than a year ago, the director of the national program on 6)immunization said Nigeria was close to stopping the disease.

W-H-O communications officer Melissa Corkum says emergency vaccination 4 campaigns will take place in Togo, Ghana and Burkina Faso. They will also take place in Benin, Cameroon and Chad to block any possible spread. Mizz Corkum says the campaigns will cost ten million dollars.

VOICE TWO:

The polio virus spreads quickly by contact with human waste through unclean conditions. The virus enters through the mouth. Within four days to a month, victims may develop a high body temperature, headaches, 7)vomiting 5 and difficulty moving.

They can lose the ability to move their arms or legs. Breathing may also become difficult. There is no cure.

In Nigeria, most polio cases are in the north. About thirty-five percent of children in the north are 8)vaccinated. Experts say at least eighty percent must get the vaccine 7 to stop the spread of polio.

But the Daily Champion newspaper in Lagos says some people are afraid of the vaccine. It says that is because of statements made by a member of the Supreme 8 Council 9 for 9)Sharia in Nigeria. Doctor Ibrahim Datti Ahmed said the vaccine is not safe.

The World Health Organization is working with traditional rulers and religious leaders in Nigeria to tell people that Doctor Ahmed is wrong.

VOICE ONE:

World health officials want to end polio by two-thousand-five. The number of new cases has dropped by ninety-nine percent. Experts say that is because so many children have received the vaccine.

Last year health workers in one hundred countries gave the polio vaccine to more than five-hundred million children. India is one country that has increased its vaccination rates. India had the highest rate of new polio cases, until the recent reports from Nigeria.

Health officials say it is important to vaccinate 6 people as soon as possible after reports of new cases. The polio vaccine is taken by mouth. It is a few drops of liquid. The vaccine does not have to be given by a health worker. Medical experts say children should receive the vaccine three times before they are one year old.

Since there is no cure, prevention is the only way to stop polio.

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VOICE TWO:

Fairness was the subject of a recent study at Emory University in Atlanta, Georgia. The study showed that humans are not the only primates 10 that dislike unequal treatment.

Sarah Brosnan and Frans de Waal led the study. They worked with brown 10)capuchin monkeys. They taught the monkeys to trade plastic tokens 12 for food. They tested the monkeys two at a time so the animals could see each other.

The monkeys like to eat 11)cucumbers. So it was easy to get them to trade tokens for cucumber 13 pieces. But it was not so easy if one monkey saw the other get a food they like even more -- a grape.

Often the insulted 14 monkey refused to give up its token 11 or rejected the piece of cucumber. Some threw the token or the cucumber out of the cage.

The researchers also gave grapes as rewards for different levels of work. Some monkeys were upset to see others receive a grape after no work at all.

VOICE ONE:

Sarah Brosnan says the study found that the capuchin monkeys compared their rewards with those of their partners. They refused to accept a lower-value reward if their partner received one of higher value. Think of how humans react when they see other someone else get a better deal.

The researchers used only female 15 capuchins. They say males are likely to share food even without a fair deal. The social system of capuchins might play a part. Males are usually either the partner of, or the father of, all the other monkeys around them.

VOICE TWO:

Sarah Brosnan says a sense of fairness is needed to live in large, complex groups. The researchers say the study supports the idea that primates developed this sense early, as cooperation evolved 16.

The findings 17 appeared last month in the publication 18 Nature. The researchers at Emory University are also doing a similar study with 12)chimpanzees.

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VOICE ONE:

An environmental group says American cities lost more than one in five of their trees during the past ten years. The group is called American Forests. It says the services that trees provide to keep air and water clean are worth thousands of millions of dollars.

American Forests released 19 a study at the National Urban Forest Conference last month in San Antonio, Texas. The group used satellite images to study tree cover in four-hundred-forty-eight cities. It compared these with images taken ten years earlier.

The study found that American cities have twenty-one percent fewer trees today. Gary Moll is an official with American Forests. He calls the problem a "tree deficit." Mister 20 Moll blames road projects and expanding areas of development.

VOICE TWO:

With fewer trees, cities have to find other ways to remove storm water. Gary Moll says trees help protect water supplies and prevent flooding. Trees also remove pollution from the air and reduce the need for electric cooling during hot weather.

American Forests says the loss is especially bad in fast-growing cities in the southern states. Gary Moll says Atlanta had the worst tree loss. The group praised San Antonio for taking steps to fight the problem. It also praised Charlotte, North Carolina, and 13)San Diego, California.

The group was started in eighteen-seventy-five to get people to plant and care for trees. It wants to plant one-thousand-seven-hundred-million trees during the next ten years to replace the lost cover.

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VOICE ONE:

A researcher in Poland says coughing hard may help people during the most common form of heart attack. Doctor Tadeusz Petelenz is a professor at the Silesian Medical School in 14)Katowice. He studied one-hundred-fifteen patients at risk of a heart attack. They were trained to cough at the first sign of an attack. They learned 21 to start with one cough every one to two seconds, in sets of five coughs.

They used this method in three-hundred-sixty-five cases when they thought they were about to lose consciousness 22. Doctor Petelenz says the symptoms disappeared in all but seventy-three cases.

VOICE TWO:

Doctor Petelenz discussed his findings about "cough C-P-R" during a recent meeting in Vienna of the European Society of 15)Cardiology. He said the pumping action caused by deep coughing forces blood to the brain when the heart begins to fail. Traditional C-P-R, or 16)cardiopulmonary 17)resuscitation 23, combines rescue breaths with compressions on the chest.

When the heart fails, victims can lose consciousness very quickly. Brain damage and death can follow within minutes. Doctor Petelenz says coughing may give a person enough time to call for help.

Most attacks are caused by a sudden problem with heart rhythm 24. Doctor Petelenz says coughing might help in these cases, called 18)arrhythmia. The traditional treatment is electric shock to the heart.

VOICE ONE:

Doctor Petelenz says cough C-P-R should be taught to the public. Some doctors have patients cough to increase blood flow during hospital treatment for heart disease. But others say the idea of cough C-P-R needs more study.

The American Heart Association 25 says it is possible that a person could send enough blood to the brain to stay conscious for a few seconds. But it says this practice is not useful enough to teach with traditional lifesaving methods.

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VOICE TWO:

SCIENCE IN THE NEWS was written by Karen Leggett, Lawan Davis, George Grow and Cynthia Kirk, who was also our producer. This is Sarah Long.

VOICE ONE:

And this is Bob Doughty. Join us again next week for more news about science in Special English on the Voice of America.

注释：

1) polio [ 5pEuliEu] n.脊髓灰质炎，小儿麻痹症

2) Ghana [ 5^B:nE ] n.加纳

3) Togo [ 5tEu^Eu ] n. 多哥

4) Burkina Faso [b\:9ki:nE 5fAsEJ] 布基纳法索(非洲国家)

5) Lagos [ 5lei^Cs ] n.尼日利亚的首都

6) immunization [ 7imju:nai5zeiFEn ] n.使免除, 使免疫

7) vomiting [5vRmItiN] n.呕吐, 呕吐物

8) vaccinate [5vAksineit ] v.进行预防接种

9) Sharia [FE`ri:E] n.伊斯兰教教法

10) capuchin [ 5kApjuFin ] (天主教的)圣方济会托钵僧

11) cucumber [ 5kju:kQmbE ] n.[植]黄瓜

12) chimpanzee [ 5tFimpEn5zi: ] n.[动]非洲的小人猿, 黑猩猩

13) San Diego [ 7sAndi(:)5ei^Eu ] n.圣地亚哥,圣迭哥

14) Katowice [ 7kB:tC:5vi:tse ] 卡托维兹(波兰南部一城市)

15) Cardiology [ 7kB:di5ClEdVi ] n.[医]心(脏)病学

16) cardiopulmonary [9kB:dIEJ`pQlmEnErI] adj.[医]心肺的, 与心肺有关的

17) resuscitation [ ri7sQsi5teiFEn ] n.复生, 复兴

18) arrhythmia [ E5riWmiE ] n.[医]心律不齐, 心律失常