VOA慢速英语-SCIENCE IN THE NEWS - Progress Seen Toward Making Ob

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 will tell about evidence that some people can be both fat and healthy. We will also tell about brain aneurysms -- a rare but deadly disorder². And, we will tell about materials that could help make objects seem to disappear.

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VOICE ONE:

Two studies are suggesting that some overweight people do not always face an increased risk of developing heart disease. Researchers also found that some normal body weight individuals have an increased risk of the disease.

Being overweight does increase your risk of medical problems. But the studies found that not all heavy people are less healthy than thin people.

VOICE TWO:

In one study, American researchers examined medical records from more than five thousand men and women. Each person had taken part in a separate study from nineteen ninety-nine to two thousand four.

The researchers found that about fifty-one percent of the subjects were overweight or obese³. About thirty-two percent were obese, but considered metabolically⁴ healthy. This means they had no evidence of problems in tests for high blood pressure or other measures linked to heart disease.

However, more than twenty-three percent of people who were at a healthy weight had two or more unhealthy measurements in the tests.

VOICE ONE:

Judith Wylie-Rosett helped supervise the American study. She is a professor at the Albert Einstein College of Medicine at Yeshiva University in New York. Professor Wylie-Rosett says the findings show that an obese person can still be healthy. She believes that having body fat is not as important to health as where the fat is found on body.

America's Centers for Disease Control and Prevention notes that two-thirds of Americans are considered overweight or obese.

VOICE TWO:

A second study is suggesting that fat in the liver may be important to health risks. Norbert Stefan and his team work at Germany's University of Tubingen. They closely examined three hundred fourteen people. They measured how much body fat each person had, and where it was on the body. To do this, they used medical imaging tests. They too discovered that obese people could have healthy hearts. Their results suggest that fat in the liver is more dangerous than fat in other areas.

The results of both studies were published recently in the Archives of Internal Medicine.

VOICE ONE:

Professor Wylie-Rosett says the findings do not mean that people should not be concerned about becoming obese. Experts say there are several diseases linked to obesity⁵ that make it more dangerous to be fat than thin. They say that people should see their doctor to learn what health risks they may be facing and what behaviors should be changed to improve health.

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VOICE TWO:

We often hear the term brain aneurysm. Joseph Biden had two brain aneurysms twenty years ago. Doctors saved his life. Recently, the senator from Delaware was named the vice⁶ presidential choice of the Democratic Party.

Ohio's first black congresswoman was not so lucky, however. Representative Stephanie Tubbs Jones died last month within hours after a brain aneurysm burst. Doctors said she may have had no warning.

VOICE ONE:

A brain aneurysm is a weak or thin area along an artery⁷ wall in the brain. It can become so thin that it ruptures⁹ and bleeds.

The most common form looks like a small, round berry hanging from the artery. The Mayo Clinic in Minnesota says as many as fifteen million people in the United States, or five percent, have a berry aneurysm. Fewer than thirty thousand will ever suffer a rupture⁸.

The National Institute of Neurological Disorders¹⁰ and Stroke says forty percent of victims die within twenty-four hours. Another twenty-five percent die within six months.

VOICE TWO:

People may live a long and healthy life and never know they have an aneurysm. But sometimes, if it gets big enough, it can cause pain or other problems that lead to its discovery.

In Senator Biden's case, his neck hurt for several weeks. Doctors thought he had a pinched nerve and a virus. But in February of nineteen eighty-eight, tests showed a leaking artery at the base of his brain. Doctors operated successfully, and again three months later for an aneurysm in another area.

Experts say most brain aneurysms happen in people born with an abnormality in an artery wall. Other causes can include head injuries, high blood pressure, infections, tobacco use and use of stimulant¹¹ drugs.

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VOICE ONE:

For years, scientists have dreamed of someday guiding or directing light in unusual ways. If they could, objects might seem to disappear. The objects would be invisible -- hidden from sight.

Now, scientists in the United States have produced materials that may help to make invisibility possible. Researchers at the University of California in Berkeley performed the experiments. Their study took steps toward "cloaking", or appearing to hide, objects.

The Lawrence Berkeley National Laboratory also took part in the experiments. Support for the work came from America's National Science Foundation and the United States military.

VOICE TWO:

Before now, invisibility experiments succeeded in guiding light around only very thin objects of two dimensions. Such objects had length and width, but no depth. The new study marks the first time experiments have been successfully done in three dimensions using visible light, or light that can be seen.

We normally see objects because light strikes them. Then our eyes receive some of the light from the objects. To make an object seem to disappear, it is necessary to direct the light so it hides the object.

The California researchers successfully did this by using materials called metamaterials. Metamaterials are small almost beyond human imagination. They are made with a process called nanoengineering.

VOICE ONE:

It was thought that directing light with natural materials was not possible. But with nanoengineered materials, the researchers were able to build a special prism. Normally, a prism has many flat surfaces. It divides white light into colors. A nanoengineered prism does the opposite. It creates white light from colors.

Results of the experiment were reported in "Science" magazine. Results with the other metamaterial appeared in the publication "Nature." University of California Professor Xiang Xhang led the research teams that developed both materials. They contained substances including metals, earthenware¹² and fiber¹³.

VOICE TWO:

The researchers designed one metamaterial like a net used to trap fish. It was made of silver nanowires. Each wire was about ten thousand times thinner than a human hair. The other metamaterial used twenty-one grids¹⁴ of silver and magnesium¹⁵ fluoride. The box-like grids formed lines. They were also unimaginably small.

Two years ago, two other researchers also reported on invisibility experiments. But they used microwaves instead of visible light. The two men were David Smith of Duke University in the United States and John Pendry of Imperial College in London.

Last year, scientists at America's Purdue University reported success in guiding light around objects placed in a design. The design employs small needles called – you guessed it – nanoneedles. Mister Pendry, Mister Smith and David Schurig developed some of the required mathematics for that research. At the same time, so did Ulf Leonhardt of the University of Saint Andrews in Scotland.

VOICE ONE:

All this recent interest in invisibility is not surprising. People have been talking about making things invisible for thousands of years. In Plato's "Republic", there is an invisible ring. In the last century, "The Shadow" was a popular radio program. It told of a man who could become invisible. That meant he could defeat all evil.

More recently, the British secret agent of many films, James Bond, had an invisible car. And Harry¹⁶ Potter, hero of many books and films, sometimes had a magic cloak. He was able to protect himself by wearing it.

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VOICE TWO:

This SCIENCE IN THE NEWS program was written by Jerilyn Watson, Caty Weaver¹⁷ and Brianna Blake, who also was our producer. I'm Barbara Klein.

VOICE ONE:

And I'm Bob Doughty. We would like to hear from you. You can read and listen to our programs at voaspecialenglish.com. Join us 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 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。

3 obese   

adj.过度肥胖的，肥大的

参考例句：

• The old man is really obese,it can't be healthy.那位老人确实过于肥胖了，不能算是健康。
• Being obese and lazy is dangerous to health.又胖又懒危害健康。

4 metabolically   

代谢的（metabolic的副词形式）

参考例句：

• Intact skin is a highly complex, metabolically active organ. 完整的皮肤是一个高度复杂、代谢灵敏的器官。 来自辞典例句

5 obesity   

n.肥胖，肥大

参考例句：

• One effect of overeating may be obesity.吃得过多能导致肥胖。
• Sugar and fat can more easily lead to obesity than some other foods.糖和脂肪比其他食物更容易导致肥胖。

6 vice   

n.坏事；恶习；[pl.]台钳，老虎钳；adj.副的

参考例句：

• He guarded himself against vice.他避免染上坏习惯。
• They are sunk in the depth of vice.他们堕入了罪恶的深渊。

7 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。

8 rupture   

n.破裂；(关系的)决裂；v.(使)破裂

参考例句：

• I can rupture a rule for a friend.我可以为朋友破一次例。
• The rupture of a blood vessel usually cause the mark of a bruise.血管的突然破裂往往会造成外伤的痕迹。

9 ruptures   

n.（体内组织等的）断裂( rupture的名词复数 )；爆裂；疝气v.（使）破裂( rupture的第三人称单数 )；（使体内组织等）断裂；使（友好关系）破裂；使绝交

参考例句：

• Fault ruptures may consist of a single narrow main break. 断层破裂可能只包括单独一条狭窄的主裂隙。 来自辞典例句
• The dry seed ruptures and the green leaf uncurls. 干瘪的种子裂开了，卷曲的绿叶伸展了。 来自辞典例句

10 disorders   

n.混乱( disorder的名词复数 )；凌乱；骚乱；（身心、机能）失调

参考例句：

• Reports of anorexia and other eating disorders are on the increase. 据报告，厌食症和其他饮食方面的功能紊乱发生率正在不断增长。 来自《简明英汉词典》
• The announcement led to violent civil disorders. 这项宣布引起剧烈的骚乱。 来自《简明英汉词典》

11 stimulant   

n.刺激物，兴奋剂

参考例句：

• It is used in medicine for its stimulant quality.由于它有兴奋剂的特性而被应用于医学。
• Musk is used for perfume and stimulant.麝香可以用作香料和兴奋剂。

12 earthenware   

n.土器，陶器

参考例句：

• She made sure that the glassware and earthenware were always spotlessly clean.她总是把玻璃器皿和陶器洗刷得干干净净。
• They displayed some bowls of glazed earthenware.他们展出了一些上釉的陶碗。

13 fiber   

n.纤维，纤维质

参考例句：

• The basic structural unit of yarn is the fiber.纤维是纱的基本结构单元。
• The material must be free of fiber clumps.这种材料必须无纤维块。

14 grids   

n.格子( grid的名词复数 )；地图上的坐标方格；（输电线路、天然气管道等的）系统网络；（汽车比赛）赛车起跑线

参考例句：

• Typical framed structures are beams, grids, plane and space frames or trusses. 典型构架结构为梁、格栅、平面的和空间的框架或桁架。 来自辞典例句
• The machines deliver trimmed grids for use or stock. 这种机器铸出修整过的板栅，以供使用或储存。 来自辞典例句

15 magnesium   

n.镁

参考例句：

• Magnesium is the nutrient element in plant growth.镁是植物生长的营养要素。
• The water contains high amounts of magnesium.这水含有大量的镁。

16 harry   

vt.掠夺，蹂躏，使苦恼

参考例句：

• Today,people feel more hurried and harried.今天，人们感到更加忙碌和苦恼。
• Obama harried business by Healthcare Reform plan.奥巴马用医改掠夺了商界。

17 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。