VOA慢速英语2010年-SCIENCE IN THE NEWS - Airport Security

BOB DOUGHTY¹: This is SCIENCE IN THE NEWS in VOA Special English. I'm Bob Doughty.

FAITH LAPIDUS: And I'm Faith Lapidus. Today, we will tell how technology used in airports may help in the study of disease. We will tell about an idea for improving heart care in developing countries. We will also tell about a project that scientists hope will protect an endangered species of frogs.

(MUSIC)

BOB DOUGHTY: Scientists say technology used to search people in airports could help doctors understand how some diseases developed.

Frank Ruhli is head of the Swiss Mummy Project at the University of Zurich. Five years ago, he used computed² tomography to study the remains³ of Tutankamun, the famous boy ruler of ancient Egypt. A computed tomography, or CT, scan provides detailed⁴ images of the inner body. Doctor Ruhli used CT scans to investigate the cause of King Tut's death.

Now, he says, technology used to search airline passengers for explosives can provide even more information. Radiation used in CT scans may be harmful to the genetic⁵ material within mummified remains. However, no radiation is involved with terahertz imaging, also known as full body scan technology.

Scientists working on the mummy of King Tutankhamun in Luxor, Egypt

Doctor Ruhli says scientists could better understand mummies if they used both CT scans and terahertz imaging technology. For example, he believes it may be possible to examine substances within a mummy, like embalming⁶ liquid.

FAITH LAPIDUS: Recently, Doctor Ruhli and his team studied ways they could use terahertz imaging to examine mummies. He says the images they gathered appear very promising⁷.

The mummification process protects the body’s soft tissue long after it would normally break down. The tissue may contain evidence of the virus or bacteria that caused the person to die.

Frank Ruhli is both a medical doctor and a paleo-pathologist. He says the information lying within mummies is not just interesting for historians, but other people. He says looking back thousands of years can help researchers look forward by understanding how a disease changed over time.

BOB DOUGHTY: Researchers can produce a genetic map of a bacterium⁸ or virus. This way, they can observe changes in the structure of a deadly organism from one generation to the next.

Doctor Ruhli says researchers used this method to study changes in the tuberculosis⁹ bacteria from two thousand year-old mummified tissue. Scientists also completed similar research on victims of the Spanish flu epidemic¹⁰ in nineteen eighteen. Frank Ruhli says studies like this can prove useful in the fight against H1N1, another form of the influenza¹¹ virus.

Doctor Ruhli presented his case for the value of mummies for medical research at a meeting of the American Association of Anatomists. He says this kind of research could never replace modern medical studies. But he says taking a long-term look at diseases can help provide information scientists might otherwise miss.

(MUSIC)

FAITH LAPIDUS: A pacemaker is a small device that doctors place in people with an abnormal heartbeat. If a heart beats too slowly, the device will use electrical signals to help set a normal rate. Some pacemakers include a defibrillator, which gives a shock if the heart beats too fast.

Pacemakers may be permanent or temporary. But one thing is sure. Developing countries need more of them as more people get heart disease.

X-ray showing a pacemaker

A big problem, however, is cost. Buying and implanting a pacemaker costs from five thousand to fifteen thousand dollars. Yet doctors at the University of Michigan think they know a way to lower that cost. The idea is to reuse pacemakers.

BOB DOUGHTY: Timir Baman is a heart doctor. He estimates that more than one million people worldwide need pacemakers each year. He says reusing a pacemaker is an ethical¹² way to provide health care to those who have no other way to get one.

Doctor Baman got the idea a few years ago. One of his patients asked if someone might have her pacemaker for reuse after she died. However, are used pacemakers safe? Doctor Baman examined medical reports about the safety of used pacemakers in small studies. He says those studies showed no real difference when a used pacemaker was compared to a new one.

FAITH LAPIDUS: Funeral directors normally remove pacemakers when preparing bodies for cremation¹³. Pacemakers can explode when burned. So Doctor Baman asked funeral directors in Michigan to send the pacemakers to him. He and other researchers at the University of Michigan Medical Center tested the used pacemakers. They cleaned and disinfected the ones in good working order. Then they sent them to doctors in the Philippines, Vietnam and Ghana.

The doctors successfully implanted the used pacemakers in twelve patients. The findings were presented at a conference of the American Heart Association.

Recently, Timir Baman asked the United States Food and Drug Administration for approval to do a larger test. He is hopeful the program will work. He would like other centers in the United States and Europe to form their own pacemaker reutilization programs. Such programs, he says, could really help many developing countries that need this kind of device.

(MUSIC)

BOB DOUGHTY: Finally, scientists say they have completed the first genetic map of an amphibian¹⁴ -- a western clawed frog. They also say the frog is one of the last invertebrates¹⁵ to have its genetic information identified. The scientists hope the work will protect endangered frog species. And, they say, the map may teach them about human disease.

Xenopus tropicalis is one of twenty frog species native to Africa, south of the Sahara. It lives almost all its life in water. One of its extended family members, Xenopus laevis, is often used in laboratory studies.

FAITH LAPIDUS: The word Xenopus means strange foot. There are about twenty different kinds of Xenopus frogs. Xenopus are very sensitive to a pregnancy¹⁶ hormone¹⁷ -- human chorionic gonadotropin. Scientists discovered the hormone last century. As a result, they used the frogs in fast-acting, low-cost pregnancy tests for women during the nineteen-forties and fifties.

Scientists also studied eggs from the frogs to learn about the development of fertilized¹⁸ eggs into embryos¹⁹.

Tropicalis is among the smaller frogs in the Xenopus group. This is one of the reasons it was chosen for the genetic map, also called a genome. The researchers knew it would be easier and less costly²⁰ to map a smaller frog with fewer chromosomal²¹ pairs.

BOB DOUGHTY: Scientists found the tropicalis genome contains more than one-point-seven-billion chemical bases along ten pairs of chromosomes²². The frog has between twenty thousand and twenty-one thousand genes²³. Human beings have about twenty-three thousand. The researchers say that about two thousand of tropicalis’ genes are similar to human genes linked to cancer, asthma²⁴ and heart disease.

Uffe Hellsten works with the Department of Energy Joint²⁵ Genome Institute in Walnut²⁶ Creek²⁷, California. It and the University of California, Berkeley, led the almost fifty scientists who helped with the frog genome project.

Mister Hellsten says the genome of the Xenopus tropicalis opens up several paths of research. He says scientists can compare genes of the frog to those of other creatures with backbones²⁸, including humans.

UFFE HELLSTEN: “To mention an example, we have found that about eighty percent of all genes that are known to be associated with human disease have a counterpart in frogs. Obviously this opens up the possibility of enhancing our understanding of many of those diseases by studying disease models in frogs.”

FAITH LAPIDUS: Mister Hellsten says to look at parts of the genome of Xenopus tropicalis is to look at structures three hundred sixty million years old. He says they are part of the genome of the last common ancestor of all birds, frogs, dinosaurs²⁹ and mammals. He says research like the frog genome project helps humans understand the history of evolution. It shows how genetic material has re-organized itself to create the genomes of modern creatures. And, Mister Hellsten says, genetic changes are rare for frogs, humans and most organisms.

A report about the study was published in Science magazine.

(MUSIC)

BOB DOUGHTY: This SCIENCE IN THE NEWS program was written by Caty Weaver³⁰ and Brianna Blake. Our producer was June Simms. I'm Bob Doughty.

FAITH LAPIDUS: And I'm Faith Lapidus. 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 computed   

adj.[医]计算的，使用计算机的v.计算，估算( compute的过去式和过去分词 )

参考例句：

• He computed that the project would take seven years to complete. 他估计这项计划要花七年才能完成。 来自《简明英汉词典》
• Resolving kernels and standard errors can also be computed for each block. 还可以计算每个块体的分辨核和标准误差。 来自辞典例句

3 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• 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。

4 detailed   

adj.详细的，详尽的，极注意细节的，完全的

参考例句：

• He had made a detailed study of the terrain.他对地形作了缜密的研究。
• A detailed list of our publications is available on request.我们的出版物有一份详细的目录备索。

5 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

6 embalming   

v.保存（尸体）不腐( embalm的现在分词 )；使不被遗忘；使充满香气

参考例句：

• The corpse was preserved from decay by embalming. 尸体用香料涂抹以防腐烂。 来自《简明英汉词典》
• They were experts at preserving the bodies of the dead by embalming them with special lotions. 他们具有采用特种药物洗剂防止尸体腐烂的专门知识。 来自辞典例句

7 promising   

adj.有希望的，有前途的

参考例句：

• The results of the experiments are very promising.实验的结果充满了希望。
• We're trying to bring along one or two promising young swimmers.我们正设法培养出一两名有前途的年轻游泳选手。

8 bacterium   

n.(pl.)bacteria 细菌

参考例句：

• The bacterium possibly goes in the human body by the mouth.细菌可能通过口进入人体。
• A bacterium is identified as the cause for his duodenal ulcer.一种细菌被断定为造成他十二指肠溃疡的根源。

9 tuberculosis   

n.结核病，肺结核

参考例句：

• People used to go to special health spring to recover from tuberculosis.人们常去温泉疗养胜地治疗肺结核。
• Tuberculosis is a curable disease.肺结核是一种可治愈的病。

10 epidemic   

n.流行病；盛行；adj.流行性的，流传极广的

参考例句：

• That kind of epidemic disease has long been stamped out.那种传染病早已绝迹。
• The authorities tried to localise the epidemic.当局试图把流行病限制在局部范围。

11 influenza   

n.流行性感冒，流感

参考例句：

• They took steps to prevent the spread of influenza.他们采取措施
• Influenza is an infectious disease.流感是一种传染病。

12 ethical   

adj.伦理的，道德的，合乎道德的

参考例句：

• It is necessary to get the youth to have a high ethical concept.必须使青年具有高度的道德观念。
• It was a debate which aroused fervent ethical arguments.那是一场引发强烈的伦理道德争论的辩论。

13 cremation   

n.火葬，火化

参考例句：

• Cremation is more common than burial in some countries. 在一些国家，火葬比土葬普遍。 来自《简明英汉词典》
• Garbage cremation can greatly reduce the occupancy of land. 垃圾焚烧可以大大减少占用土地。 来自互联网

14 amphibian   

n.两栖动物；水陆两用飞机和车辆

参考例句：

• The frog is an amphibian,which means it can live on land and in water.青蛙属于两栖动物，也就是说它既能生活在陆地上也能生活在水里。
• Amphibian is an important specie in ecosystem and has profound meaning in the ecotoxicology evaluation.两栖类是生态系统中的重要物种，并且对环境毒理评价有着深远意义。

15 invertebrates   

n.无脊椎动物( invertebrate的名词复数 )

参考例句：

• Insects and worms are all invertebrates. 昆虫和蠕虫都是无脊椎动物。 来自辞典例句
• In the earthworm and many other invertebrates, these excretory structures are called nephridia. 在蚯蚓和许多其它无脊椎动物中，这些排泄结构称为肾管。 来自辞典例句

16 pregnancy   

n.怀孕，怀孕期

参考例句：

• Early pregnancy is often accompanied by nausea.怀孕早期常有恶心的现象。
• Smoking during pregnancy increases the risk of miscarriage.怀孕期吸烟会增加流产的危险。

17 hormone   

n.荷尔蒙，激素，内分泌

参考例句：

• Hormone implants are used as growth boosters.激素植入物被用作生长辅助剂。
• This hormone interacts closely with other hormones in the body.这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。

18 Fertilized   

v.施肥( fertilize的过去式和过去分词 )

参考例句：

• The study of psychology has recently been widely cross-fertilized by new discoveries in genetics. 心理学研究最近从遗传学的新发现中受益匪浅。
• Flowers are often fertilized by bees as they gather nectar. 花常在蜜蜂采蜜时受粉。

19 embryos   

n.晶胚；胚，胚胎( embryo的名词复数 )

参考例句：

• Somatic cells of angiosperms enter a regenerative phase and behave like embryos. 被子植物体细胞进入一个生殖阶段，而且其行为象胚。 来自辞典例句
• Evolution can explain why human embryos look like gilled fishes. 进化论能够解释为什么人类的胚胎看起来象除去了内脏的鱼一样。 来自辞典例句

20 costly   

adj.昂贵的，价值高的，豪华的

参考例句：

• It must be very costly to keep up a house like this.维修这么一幢房子一定很昂贵。
• This dictionary is very useful,only it is a bit costly.这本词典很有用，左不过贵了些。

21 chromosomal   

adj.染色体的

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
• In mammalian species, a variety of chromosomal rearrangements are known to exist. 在哺乳类的物种中，已知有许多类型的染色体内部重新排列。 来自辞典例句

22 chromosomes   

n.染色体( chromosome的名词复数 )

参考例句：

• Chromosomes also determine the sex of animals. 染色体也决定动物的性别。 来自《简明英汉词典》
• Each of four chromosomes divide longitudinally. 四种染色体的每一种都沿着纵向分裂。 来自《现代汉英综合大词典》

23 genes   

n.基因( gene的名词复数 )

参考例句：

• 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

24 asthma   

n.气喘病，哮喘病

参考例句：

• I think he's having an asthma attack.我想他现在是哮喘病发作了。
• Its presence in allergic asthma is well known.它在过敏性气喘中的存在是大家很熟悉的。

25 joint   

adj.联合的，共同的；n.关节，接合处；v.连接，贴合

参考例句：

• I had a bad fall,which put my shoulder out of joint.我重重地摔了一跤，肩膀脫臼了。
• We wrote a letter in joint names.我们联名写了封信。

26 walnut   

n.胡桃，胡桃木，胡桃色，茶色

参考例句：

• Walnut is a local specialty here.核桃是此地的土特产。
• The stool comes in several sizes in walnut or mahogany.凳子有几种尺寸，材质分胡桃木和红木两种。

27 creek   

n.小溪，小河，小湾

参考例句：

• He sprang through the creek.他跳过小河。
• People sunbathe in the nude on the rocks above the creek.人们在露出小溪的岩石上裸体晒日光浴。

28 backbones   

n.骨干( backbone的名词复数 )；脊骨；骨气；脊骨状物

参考例句：

• Why do hummingbirds and gorillas both have backbones? 为什么蜂鸟和大猩猩都有脊骨？ 来自辞典例句
• Simply adding bandwidth to the Internet backbones is not an answer. 只是简单的在互联网骨架上增加带宽是应付不了的。 来自互联网

29 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》

30 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。