SCIENCE IN THE NEWS - Sticking Power: Geckos Face Some Compe

SCIENCE IN THE NEWS - Sticking Power: Geckos Face Some Competition
By George Grow, Shelley Gollust, Jill Moss¹ and Cynthia Kirk

Broadcast: Tuesday, September 06, 2005

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VOICE ONE:

This is SCIENCE IN THE NEWS in VOA Special English. I'm Barbara Klein.

VOICE TWO:

And I'm Bob Doughty². This week on our show -- a study dismisses homeopathic medicine.

VOICE ONE:

Research links the ancient custom of female genital cutting to infertility³.

VOICE TWO:

New findings might help explain why cocaine⁴ users have a higher risk of heart attacks.

VOICE ONE:

And some lizards⁵ famous for their sticking power have some new competition in the laboratory.

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Geckos are small lizards that live in warm climates. These lizards can stick to any surface. For example, geckos can climb up walls and across the top of a room. Scientists have studied the little creatures for hundreds of years to learn the secret of how they stick to things. They hoped the findings would help them develop powerful materials that hold things together.

A few years ago, American scientists solved the mystery. They found that geckos have five hundred thousand very small hairs on the bottoms of their feet. The end of each hair splits into hundreds of smaller hairs. So the geckos' feet have hundreds of millions of tiny hairs that touch a surface and hold the feet in place.

VOICE TWO:

America's National Science Foundation gave money to scientists at the University of Akron in Ohio and Rensselaer Polytechnic⁶ Institute in Troy, New York. The scientists worked to make material like the hairs on geckos' feet. The team recently reported that it had produced hairs that have two hundred times the sticking power of natural gecko hairs.

VOICE ONE:

The scientists have tested only small amounts of the material. But they estimate that an amount of the material the size of a small piece of money could hold up to about ten kilograms.

The hairs made by the scientists are only one ten-thousandth the width of a human hair. They are made of extremely small movable carbon tubes, called nanotubes, placed in a plastic base.

Ali Dhinojwala is one of the scientists at the University of Akron. He says the tubes are strong and generally unbreakable. He says the team will continue testing larger amounts of the material. The study was published in Chemical Communications.

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VOICE TWO:

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

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A new report disputes the medical value of homeopathic treatments. It says such treatments have the same effect as a placebo⁷. A placebo looks like medicine but contains no active substance. Yet it can sometimes have an effect on people if they do not know it is only a placebo.

Matthias Egger of the University of Berne in Switzerland led a team. His group compared studies of homeopathic treatments with studies of medical drugs. They compared one hundred ten studies of each. The findings are published in The Lancet.

The scientists say there was not enough evidence to show that homeopathy worked better than a placebo in studies with both. Still, they noted⁸ the limits of science to disprove something. In their words, "We acknowledge that to prove a negative is impossible."

VOICE ONE:

The word homeopathy has roots in two Greek words. Homoio means similar. Pathos⁹ is suffering or disease.

A German doctor, Samuel Hahnemann, developed homeopathic medicine in the seventeen nineties. He believed that some substances could cure diseases if they produced effects similar to those of the disease itself. He believed that these substances -- from plants, minerals or animals -- helped the body's own defense¹⁰ system to fight the sickness.

Homeopaths say traditional doctors too often use medicines without considering all the possible causes of a disorder¹¹. They say they carefully consider both the physical and emotional health of a person. They say their goal is to strengthen the body's natural ability to cure itself.

Treatments might involve deadly substances like snake poison or arsenic¹². But they are given in very small amounts. The idea is that they are too weak to cause harm.

VOICE TWO:

Even critics of homeopathy agree that it sometimes works. But they say this is only because a patient thinks it will work. In other words, a placebo effect. Professor Egger says homeopathic treatments are likely to show effects in smaller, low quality studies. However, his group found that the effect disappears in larger, more careful studies.

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VOICE ONE:

New findings might help explain why users have a higher risk of heart attacks. Researchers found that users of the illegal drug increase the risk of aneurysms in their coronary arteries¹³.

Coronary arteries carry blood with oxygen to the heart. Aneurisms are weak areas in the walls of blood vessels¹⁴. The area becomes filled with blood like a balloon. Aneurysms happen more often in the brain and the aorta¹⁵, which carries blood away from the heart. If they burst, they can cause brain damage and sudden death.

 
Cocaine
The researchers say aneurysms in the coronary arteries rarely burst but may lead to a heart attack, at least in cocaine users. The study is described as the first to document a link between cocaine and coronary aneurysms. Cocaine users in their early forties had four times the risk as non-users in the same age group.

VOICE TWO:

The researchers examined the records of people who had been tested for known or suspected heart problems. The study found signs of coronary aneurysms in almost eight percent of those who did not use cocaine. In those who did, the finding was thirty percent.

Doctor Timothy Henry was the lead writer of the study. He directs research at the Minneapolis Heart Institute Foundation. The study appeared in Circulation, published by the American Heart Association.

VOICE ONE:

Tobacco adds to the risk of aneurisms and heart attacks. Almost all of the cocaine users smoked cigarettes. The researchers knew from the medical records how often about half of them took cocaine. Two-thirds reported they used it at least once a week.

The study suggests two possible ways that cocaine might lead to an aneurism. One is through damage to the cells inside the arteries. The other is through sharp increases in blood pressure. Then, once an aneurysm forms, it may lead to a blockage¹⁶ in the flow of blood and cause a heart attack.

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VOICE TWO:

New research suggests that the custom in parts of Africa and Asia to cut the sex organs of girls can cause infertility later in life. Researchers believe this is the result of infections that spread to the reproductive organs.

The Swedish-led study took place in Sudan. The findings appeared in The Lancet. The researchers linked the risk of infertility to the extent of the cutting. Infertile¹⁷ women were five to six times more likely to have had the most severe cutting than women who were able to get pregnant. But the researchers say any damage could lead to changes that harm reproductive health.

Each year, an estimated two million more girls reach the age where they might be cut. But experts have found a reduction in this custom in a number of countries. The United Nations Children's Fund seeks an end to female genital mutilation by two thousand ten.

VOICE ONE:

Our program was written by George Grow, Shelley Gollust, Jill Moss and Cynthia Kirk, who was also our producer. SCIENCE IN THE NEWS can be found on the Web at www.tingroom.com. I'm Barbara Klein.

VOICE TWO:

And I'm Bob Doughty. To send us e-mail, write to [email protected]. And please join us again next week for more news about science in Special English on the Voice of America.

1 moss   

n.苔，藓，地衣

参考例句：

• Moss grows on a rock.苔藓生在石头上。
• He was found asleep on a pillow of leaves and moss.有人看见他枕着树叶和苔藓睡着了。

2 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。

3 infertility   

n.不肥沃，不毛；不育

参考例句：

• It is the Geneva, Switzerland-based Biotech Company's second recombinant infertility drug. 它是瑞士生物技术公司在日内瓦的公司生产的第二种重组治疗不孕症的药。 来自英汉非文学 - 生命科学 - 生物技术制药疫苗
• Endometritis is a cause of infertility. 子宫内膜炎是不育的原子。 来自辞典例句

4 cocaine   

n.可卡因，古柯碱（用作局部麻醉剂）

参考例句：

• That young man is a cocaine addict.那个年轻人吸食可卡因成瘾。
• Don't have cocaine abusively.不可滥服古柯碱。

5 lizards   

n.蜥蜴( lizard的名词复数 )

参考例句：

• Nothing lives in Pompeii except crickets and beetles and lizards. 在庞培城里除了蟋蟀、甲壳虫和蜥蜴外，没有别的生物。 来自辞典例句
• Can lizards reproduce their tails? 蜥蜴的尾巴断了以后能再生吗？ 来自辞典例句

6 polytechnic   

adj.各种工艺的，综合技术的；n.工艺(专科)学校；理工(专科)学校

参考例句：

• She was trained as a teacher at Manchester Polytechnic.她在曼彻斯特工艺专科学校就读，准备毕业后做老师。
• When he was 17,Einstein entered the Polytechnic Zurich,Switzerland,where he studied mathematics and physics.17岁时，爱因斯坦进入了瑞士苏黎士的专科学院，学习数学和物理学。

7 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。

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 pathos   

n.哀婉，悲怆

参考例句：

• The pathos of the situation brought tears to our eyes.情况令人怜悯，看得我们不禁流泪。
• There is abundant pathos in her words.她的话里富有动人哀怜的力量。

10 defense   

n.防御，保卫；[pl.]防务工事；辩护，答辩

参考例句：

• 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。

11 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。

12 arsenic   

n.砒霜，砷；adj.砷的

参考例句：

• His wife poisoned him with arsenic.他的妻子用砒霜把他毒死了。
• Arsenic is a poison.砒霜是毒药。

13 arteries   

n.动脉( artery的名词复数 )；干线，要道

参考例句：

• Even grafting new blood vessels in place of the diseased coronary arteries has been tried. 甚至移植新血管代替不健康的冠状动脉的方法都已经试过。 来自《简明英汉词典》
• This is the place where the three main arteries of West London traffic met. 这就是伦敦西部三条主要交通干线的交汇处。 来自《简明英汉词典》

14 vessels   

n.血管( vessel的名词复数 )；船；容器；（具有特殊品质或接受特殊品质的）人

参考例句：

• The river is navigable by vessels of up to 90 tons. 90 吨以下的船只可以从这条河通过。 来自《简明英汉词典》
• All modern vessels of any size are fitted with radar installations. 所有现代化船只都有雷达装置。 来自《现代汉英综合大词典》

15 aorta   

n.主动脉

参考例句：

• The abdominal aorta is normally smaller than the thoracic aorta.腹主动脉一般比胸主动脉小。
• Put down that jelly doughnut and look carefully at this aorta.放下手头上的东西，认真观察这张大动脉图片。

16 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。

17 infertile   

adj.不孕的；不肥沃的，贫瘠的

参考例句：

• Plants can't grow well in the infertile land.在贫瘠的土地上庄稼长不好。
• Nobody is willing to till this infertile land.这块薄田没有人愿意耕种。