SCIENCE IN THE NEWS

SCIENCE IN THE NEWS
By

Broadcast: Tuesday, March 23, 2004

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VOICE ONE:

This is Science in the News, in VOA Special English. I'm Bob Doughty¹.

VOICE TWO:

And I'm Sarah Long. This week: meet Sedna the planetoid.

VOICE ONE:

Learn how satellites may give early warning of disease outbreaks.

VOICE TWO:

Also, a study of sexually transmitted diseases in young Americans.

VOICE ONE:

And a report on World TB Day, all coming up.

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VOICE TWO:

 
Artist's version of Sedna.
Scientists have found an object far away in our solar system. They say it is planet-like. They are calling it a planetoid.

The red object is thirteen-thousand-million kilometers from Earth. But it will get ten times farther. It is the most distant object known to orbit the sun. The discovery means that the solar system is bigger than scientists thought.

NASA, the American space agency, helped pay for the research. Michael Brown of the California Institute of Technology, Caltech, in Pasadena led the team. Chad Trujillo of Gemini Observatory² in Hilo, Hawaii, also took part. So did David Rabinowitz of Yale University in New Haven³, Connecticut.

VOICE ONE:

 
Arrow points to Sedna in this discovery photo taken from the Palomar Observatory. The planetoid is three times farther from Earth than Pluto⁴ is.
The three scientists first saw the object in November though a telescope at the Palomar Observatory in California. They named it Sedna, after a goddess of the Inuit people of the Arctic. Tradition says she lived in an icy cave at the bottom of the ocean and created the sea creatures of the Arctic.

But Sedna the planetoid is in a much colder place. The scientists estimate the surface temperature at about two-hundred-forty degrees below zero Celsius⁵. When Sedna is even farther from the sun, the temperature drops close to what scientists call absolute zero. This is minus two-hundred-seventy-three degrees Celsius. In theory, this is as cold as cold can get.

VOICE TWO:

So why is Sedna called a planetoid, and not our tenth planet? Mostly because of its size. The scientists measure Sedna at about one-thousand-seven-hundred kilometers around. This is about twenty-five percent smaller than the smallest planet, Pluto.

Sedna also has an unusual orbit. The shape is much more elliptical than the orbits of most of the planets. Picture a circle stretched far from two opposite points.

So how far away does Sedna get? Consider it this way: Sedna takes more than ten-thousand years to travel around the sun. Earth takes one year.

VOICE ONE:

Michael Brown at Caltech says the planetoid is evidence of what scientists call the Oort Cloud. This is an area of comets that orbit the sun, at least in theory. But others think Sedna is more likely part of the Kuiper Belt. This is an area of asteroids⁶ and other objects in orbit.

Either way, the scientists all seem to agree that Sedna may tell much about the history of our solar system.

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Here on Earth, NASA scientists think satellites can tell when and where diseases might appear. The idea is to look for environmental conditions that increase populations of insects like mosquitoes that spread malaria⁷.

VOICE ONE (CONT):

Ronald Welch works at the NASA Global Hydrology and Climate Center in Huntsville, Alabama. Mister Welch says scientists and health workers are now visiting places where diseases have already appeared. They are also studying satellite images to see how these areas look from space.

NASA says a Russian scientist, E.N. Pavlovsky, first expressed such an idea in the nineteen-sixties.

VOICE TWO:

Ronald Welch is working with health officials in India to develop an early warning system. They are working in an area of more than four-hundred villages south of New Delhi. Mister Welch says the hope in the near future is to provide about a one-month warning before a malaria outbreak.

Mosquitoes lay their eggs in water. Satellites would find an area with a lot of rainwater on the ground. Scientists also know that temperatures must be at least eighteen-degrees Celsius for the disease to survive in the mosquitoes. When conditions seem right for malaria to appear, workers would go to the area. They would spray chemicals to kill the young mosquitoes before they leave the water.

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VOICE ONE:

This is Science in the News, in VOA Special English.

Wednesday, March twenty-fourth, is World TB Day. TB is the lung disease tuberculosis⁸. India will lead the observance this year with public health events. Health experts say a new person is infected with TB somewhere in the world every second. Then they spread the bacteria through the air when they cough or sneeze.

The problem is even more serious among refugees. The World Health Organization says half of all refugees may be infected with TB. Refugees often live in crowded conditions and do not have enough food or health care.

Many people leave refugee camps to look for work or family members, or to return home. If they start treatment in the camp, but discontinue it when they leave, the infection may stay in their bodies. Then the disease becomes harder to cure, and easier to spread.

VOICE TWO:

Medicine can take six to eight months to cure TB. But doctors say a person who takes the medicine stops infecting other people in about two weeks.

The World Health Organization says refugees with TB should take a combination of four medicines for at least two to three months. Then they are close to being cured and will not spread the infection.

Tuberculosis in children may affect any part of the body. Children should be examined for TB if they are sick for more than ten days. Weight loss and a lack of energy are two possible signs. Children should also be examined if they live close to someone with TB.

VOICE ONE:

Experts say mothers who are infected with TB should continue to breastfeed their babies. Mother's milk helps protect babies against disease. Babies may die from other diseases if they stop nursing.

Also, health workers urge people to cover their mouth when they cough. And people should not discontinue their medicine when they begin to feel better. They must continue to take the medicine to kill all the germs.

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VOICE TWO:

Now we talk about another way diseases are spread.

Researchers have just published a study of sexually transmitted diseases in the United States in two-thousand. They say there were nineteen-million new cases that year. Almost half were in people between the ages of fifteen and twenty-four. Yet people in this age group represent only twenty-five percent of what the researchers call the sexually experienced population.

Researchers from the Centers for Disease Control and Prevention wrote two reports. Both appear in Perspectives in Sexual and Reproductive Health, published by the Alan Guttmacher Institute.

Sharon Camp heads this non-profit group in New York. She says most young people are sexually active. However, she says many are poorly equipped to prevent infections or to seek testing and treatment.

VOICE ONE:

The researchers say nine-million infections were reported in young people in two-thousand. They estimate the cost to treat these people over their lifetimes could reach more than six-thousand-million dollars. Most of the cost is connected to the treatment of H.I.V., the virus that causes AIDS.

But AIDS is not the only threat from sexually transmitted diseases. Three other diseases represent almost ninety percent of all new cases among people in the United States age fifteen to twenty-four.

One is the human papillomavirus. H.P.V is usually harmless and goes away. But some forms can cause cervical cancer and other conditions. The two other diseases are trichomoniasis and chlamydia. Doctors treat these with antibiotics⁹. Yet many people never know they have a sexually transmitted disease, unless they go for a test.

VOICE ONE:

Health experts and a group of young people prepared a separate report released by the University of North Carolina.

It says programs that only teach young people not to have sex until marriage will not control the spread of disease. In January, President Bush proposed a one-hundred-percent increase in federal money for programs that teach abstinence.

The report says young people need to learn about abstinence. But it says they also need realistic advice about other ways to prevent infection.

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VOICE TWO:

SCIENCE IN THE NEWS was written by Caty Weaver¹⁰, Paul Thompson, Karen Leggett and Cynthia Kirk, who was also our producer. I'm Sarah Long.

VOICE ONE:

And I'm Bob Doughty. Join us 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 observatory   

n.天文台，气象台，瞭望台，观测台

参考例句：

• Guy's house was close to the observatory.盖伊的房子离天文台很近。
• Officials from Greenwich Observatory have the clock checked twice a day.格林威治天文台的职员们每天对大钟检查两次。

3 haven   

n.安全的地方，避难所，庇护所

参考例句：

• It's a real haven at the end of a busy working day.忙碌了一整天后，这真是一个安乐窝。
• The school library is a little haven of peace and quiet.学校的图书馆是一个和平且安静的小避风港。

4 Pluto   

n.冥王星

参考例句：

• Pluto is the furthest planet from the sun.冥王星是离太阳最远的行星。
• Pluto has an elliptic orbit.冥王星的轨道是椭圆形的。

5 Celsius   

adj.摄氏温度计的，摄氏的

参考例句：

• The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
• The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。

6 asteroids   

n.小行星( asteroid的名词复数 )；海盘车，海星

参考例句：

• Asteroids,also known as "minor planets",are numerous in the outer space. 小行星，亦称为“小型行星”，在外太空中不计其数。
• Most stars probably have their quota of planets, meteorids, comets, and asteroids. 多数恒星也许还拥有若干行星、流星、彗星和小行星。

7 malaria   

n.疟疾

参考例句：

• 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。

8 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。

9 antibiotics   

n.（用作复数）抗生素；（用作单数）抗生物质的研究；抗生素，抗菌素( antibiotic的名词复数 )

参考例句：

• the discovery of antibiotics in the 20th century 20世纪抗生素的发现
• The doctor gave me a prescription for antibiotics. 医生给我开了抗生素。

10 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。