时间:2018-12-16 作者:英语课 分类:2012年VOA慢速英语(一)月


英语课

SCIENCE IN THE NEWS - A Soft Body, but the Mind of a Robot


 


SHIRLEY GRIFFITH: This is SCIENCE IN THE NEWS in VOA Special English. I'm Shirley Griffith.



STEVE EMBER: And I'm Steve Ember. Today, we tell about soft-bodied robots -- robots that can move more easily than those made of metal. We also tell about efforts to control the disease malaria 1. And we tell about how being president of the United States can be good for your health.



(MUSIC)



SHIRLEY GRIFFITH: When many of us think of robots, we picture large, metal objects in the shape of humans, having difficulty moving around. But robots have come a long way. A team at Harvard University in Massachusetts recently developed a soft-bodied robot. The team based the design of its robot on sea creatures without hard shells or skeletons.



STEVE EMBER: The robotic device was made with soft materials called elastomers. It is about thirteen centimeters long and has four legs that can move separately. The movements are controlled by compressed air and can be operated from a computer.



George Whitesides led the Harvard researchers. The United States Department of Defense 2 paid for the project.









An elastomeric gripper robot




The robot itself took two months to develop. In tests, researchers have guided the robot under a plate of glass less than three centimeters high. The researchers say their invention can move at a speed of about thirteen meters an hour.



A report about the robot was published in November in the journal Proceedings 3 of the National Academy of Sciences.



SHIRLEY GRIFFITH: Increasingly, soft robots are being developed for difficult jobs like moving through a battlefield or wreckage 4 from a natural disaster. The robot can move across uneven 5 surfaces including small rocks and wet dirt.



Earlier this year, scientists from Tufts University in Massachusetts developed another kind of soft robot made of silicone rubber. This robot is about ten centimeters long and shaped like a caterpillar 6. It is able to roll up into a ball shape and move itself forward.



But researchers say there are difficulties in making these robots move. For one, they want to find a way for the robot to transport its own power source. They are also hoping to improve its speed.



(MUSIC)



STEVE EMBER: The World Health Organization says malaria was responsible for seven hundred eighty-one thousand deaths in two thousand nine. Most of those deaths were in children in Africa. Worldwide there were two hundred twenty-five million cases of the disease.



Both of these numbers represent improvements. In two thousand there were an estimated two hundred thirty-three million cases of malaria and almost a million deaths.



Malaria remains 7 a major problem in Africa, but there have been some successes. Deaths in Rwanda, for example, have been reduced by sixty percent.



SHIRLEY GRIFFITH: The main way for communities to control malaria is by controlling mosquitoes. The disease comes from a parasite 8 spread through the bite of infected mosquitoes.



In a recent study, researchers in West Africa showed that an insecticide spray can greatly reduce malaria transmission. Researchers at the Center de Recherche 9 Entomologique de Cotonou tested a chemical called bendiocarb. They tested it with indoor spraying at sites throughout Benin.



The study found there were fewer mosquito bites in homes sprayed with bendiocarb. More importantly, none of the three hundred fifty-thousand people who lived there got malaria-infected mosquito bites during the test.



STEVE EMBER:Malaria control efforts currently depend on things like chemically treated bed nets and spraying against mosquitoes. But scientists keep trying to find other ways to prevent the disease.








Mosquito feeding from human finger




There are still no vaccines 11 to prevent malaria. But a number of vaccines remain under development. Most contain genetically 12 engineered versions of a few proteins from the Plasmodium parasite.



Plasmodium is the organism that causes malaria. Those modified proteins are designed to get the body's defenses to launch an immune response against the Plasmodium. But the parasite contains thousands of proteins.



SHIRLEY GRIFFITH: Another experimental vaccine 10 includes a deactivated 13 version of the entire parasite. Robert Seder works at the National Institute of Allergy 15 and Infectious Diseases, near Washington.



ROBERT SEDER: "So instead of picking out one or two or three genes 16, you have the potential for what we call breadth -- generating an immune response that would be broad rather than narrower. And so that would be a good thing."



Radiation is used to weaken the parasite so it cannot make people sick or get spread by a mosquito. To make the vaccine, scientists use the parasite at a time in its growth when the organism is called a sporozoite.



This idea has been known since the nineteen sixties. But Mr. Seder says a discovery by a researcher at a vaccine company cleared the way for progress.



ROBERT SEDER: "The major breakthrough here was that my collaborator 17, Stephen Hoffman at Sanaria, developed a method where he could isolate 18 the sporozoites and purify them so that they could administer it as a vaccine to humans. And no one thought that that was possible."



But no one knew either if the weakened sporozoites would activate 14 the immune system to protect against malaria. So researchers tested it on volunteers and found that it was safe -- there were only minor 19 side effects. But it was not very effective. Only two out of forty-four volunteers were protected when bitten by malaria-infected mosquitoes.



STEVE EMBER: To find out why, the researchers tested the vaccine on laboratory animals. They decided 20 that the problem was the way the vaccine had been given to the volunteers. It was injected into the skin, to simulate the bite of a mosquito. Mr. Seder says it would have been more effective if it had been given directly into the blood.



For now, more testing is needed. A report on the testing appeared in Science magazine.



(MUSIC)



SHIRLEY GRIFFITH: Finally, many Americans say the hardest job in the world is being president of the United States. The man, or woman, who lives and works in the White House must be able to deal with problems twenty-four hours a day, seven days a week. Even on holidays or in the middle of the night, the president may have to make decisions that affect both people in this country and the rest of the world.



That is why some news media tell about changes in a president's personal appearance during his time in office. Last August, President Obama celebrated 21 his fiftieth birthday. Some pictures showed him as a man with grayer hair and more lines on his face than when he first took office. And that got researcher S. Jay Olshansky to thinking. He studies aging at the University of Illinois at Chicago.



STEVE EMBER: Doctors nearly always say that high levels of stress are bad for your health. So people would expect a president's life to be shorter than average. Some people even say that being president could cause a person to age two times as fast as normal. But Professor Olshansky was not persuaded. So he examined the lives of the thirty-four American presidents who died of natural causes. He found that twenty-three of them lived longer than most people born at the same time.



The average age of those thirty-four presidents when they died was seventy-three. If they had aged 22 two times as fast as normal, they should have lived to be only sixty-eight point one years old. The professor also found that the first eight presidents lived an average of seventy-nine point eight years. At that time, modern medicines had not been invented, and most men lived only about forty years.








Former U.S. President Gerald Ford 23 and his wife Betty. President Ford lived to be ninety-three, older than any other president.




Four American presidents lived past ninety. John Adams, Herbert Hoover, and Ronald Reagan each lived ninety or more years. But Gerald Ford lived longer than any other president. He was ninety-three and a half when he died in two thousand six.



SHIRLEY GRIFFITH: Professor Olshansky says gray hair, hair loss and other changes are part of aging and may result from something in our genes. So presidents are no different from the rest of us. But the researcher thinks there are three reasons they outlive other people. Most presidents are well-educated. Many are wealthy when compared to other Americans. And they have the best medical care possible. They know how to stay healthy, and have the best doctors. As a result, they can afford to live a healthy life long after they leave the White House.



Professor Olshansky says, "It is a classic illustration of the benefits of socioeconomic status." His study was published last month in the Journal of the American Medical Association.



(MUSIC)



STEVE EMBER: This SCIENCE IN THE NEWS was written by Brianna Blake, Christopher Cruise and Jim Tedder 24. I'm Steve Ember.



SHIRLEY GRIFFITH: And I'm Shirley Griffith. Join us again next week for more news about science in Special English on the Voice of America.



1 malaria
n.疟疾
  • He had frequent attacks of malaria.他常患疟疾。
  • Malaria is a kind of serious malady.疟疾是一种严重的疾病。
2 defense
n.防御,保卫;[pl.]防务工事;辩护,答辩
  • The accused has the right to defense.被告人有权获得辩护。
  • The war has impacted the area with military and defense workers.战争使那个地区挤满了军队和防御工程人员。
3 proceedings
n.进程,过程,议程;诉讼(程序);公报
  • He was released on bail pending committal proceedings. 他交保获释正在候审。
  • to initiate legal proceedings against sb 对某人提起诉讼
4 wreckage
n.(失事飞机等的)残骸,破坏,毁坏
  • They hauled him clear of the wreckage.他们把他从形骸中拖出来。
  • New states were born out of the wreckage of old colonial empires.新生国家从老殖民帝国的废墟中诞生。
5 uneven
adj.不平坦的,不规则的,不均匀的
  • The sidewalk is very uneven—be careful where you walk.这人行道凹凸不平—走路时请小心。
  • The country was noted for its uneven distribution of land resources.这个国家以土地资源分布不均匀出名。
6 caterpillar
n.毛虫,蝴蝶的幼虫
  • A butterfly is produced by metamorphosis from a caterpillar.蝴蝶是由毛虫脱胎变成的。
  • A caterpillar must pass through the cocoon stage to become a butterfly.毛毛虫必须经过茧的阶段才能变成蝴蝶。
7 remains
n.剩余物,残留物;遗体,遗迹
  • He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
  • The remains of the meal were fed to the dog.残羹剩饭喂狗了。
8 parasite
n.寄生虫;寄生菌;食客
  • The lazy man was a parasite on his family.那懒汉是家里的寄生虫。
  • I don't want to be a parasite.I must earn my own way in life.我不想做寄生虫,我要自己养活自己。
9 recherche
adj.精选的;罕有的
  • Applicants should have good PC skills with common office software,email and internet recherche.在办公软件、电子邮件、网络检索等个人电脑应用方面,申请人应具备良好的操作技能。
  • The restaurant prides itself on its recherche menu.饭店以其精美的菜单自豪。
10 vaccine
n.牛痘苗,疫苗;adj.牛痘的,疫苗的
  • The polio vaccine has saved millions of lives.脊髓灰质炎疫苗挽救了数以百万计的生命。
  • She takes a vaccine against influenza every fall.她每年秋季接种流感疫苗。
11 vaccines
疫苗,痘苗( vaccine的名词复数 )
  • His team are at the forefront of scientific research into vaccines. 他的小组处于疫苗科研的最前沿。
  • The vaccines were kept cool in refrigerators. 疫苗放在冰箱中冷藏。
12 genetically
adv.遗传上
  • All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
  • Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物
13 deactivated
v.解除动员( deactivate的过去式和过去分词 );使无效;复员;使不活动
  • \"The brain can be deactivated. It can be yours to command.\" “大脑计算机可以被停止。如果你下达命令的话。” 来自互联网
  • He successfully deactivated a nuclear reactor in a laboratory before meltdown. 他成功停用一个核反应堆在实验室之前崩溃。 来自互联网
14 activate
vt.使活动起来,使开始起作用
  • We must activate the youth to study.我们要激励青年去学习。
  • These push buttons can activate the elevator.这些按钮能启动电梯。
15 allergy
n.(因食物、药物等而引起的)过敏症
  • He developed an allergy to pollen.他对花粉过敏。
  • The patient had an allergy to penicillin.该患者对青霉素过敏。
16 genes
n.基因( gene的名词复数 )
  • 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
17 collaborator
n.合作者,协作者
  • I need a collaborator to help me. 我需要个人跟我合作,帮我的忙。
  • His collaborator, Hooke, was of a different opinion. 他的合作者霍克持有不同的看法。
18 isolate
vt.使孤立,隔离
  • Do not isolate yourself from others.不要把自己孤立起来。
  • We should never isolate ourselves from the masses.我们永远不能脱离群众。
19 minor
adj.较小(少)的,较次要的;n.辅修学科;vi.辅修
  • The young actor was given a minor part in the new play.年轻的男演员在这出新戏里被分派担任一个小角色。
  • I gave him a minor share of my wealth.我把小部分财产给了他。
20 decided
adj.决定了的,坚决的;明显的,明确的
  • This gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
  • There is a decided difference between British and Chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。
21 celebrated
adj.有名的,声誉卓著的
  • He was soon one of the most celebrated young painters in England.不久他就成了英格兰最负盛名的年轻画家之一。
  • The celebrated violinist was mobbed by the audience.观众团团围住了这位著名的小提琴演奏家。
22 aged
adj.年老的,陈年的
  • He had put on weight and aged a little.他胖了,也老点了。
  • He is aged,but his memory is still good.他已年老,然而记忆力还好。
23 Ford
n.浅滩,水浅可涉处;v.涉水,涉过
  • They were guarding the bridge,so we forded the river.他们驻守在那座桥上,所以我们只能涉水过河。
  • If you decide to ford a stream,be extremely careful.如果已决定要涉过小溪,必须极度小心。
24 tedder
n.(干草)翻晒者,翻晒机
  • Jim Tedder has more. 吉姆?特德将给我们做更多的介绍。 来自互联网
  • Jim Tedder tells us more. 吉姆?泰德给我们带来更详细的报道。 来自互联网
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