SCIENCE IN THE NEWS(在线收听

SCIENCE IN THE NEWS
By Cynthia Kirk, Jerilyn Watson

Broadcast: Tuesday, November 30, 2004

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VOICE ONE:

This is SCIENCE IN THE NEWS, in VOA Special English. I'm Faith Lapidus.

VOICE TWO:

And I'm Bob Doughty. On our program this week: a possible health risk for users of cellular telephones and we answer a listener's question about computers.

VOICE ONE:

But first, a discovery that could help scientists better understand how great apes developed.

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VOICE ONE:

 
AP Photo
Research scientists in Spain have discovered fossil remains of an ape-like animal that lived about thirteen million years ago. The researchers believe the fossils might be from the last common ancestor of all great apes alive today. Or, they say the fossils might be from a creature similar to the last ancestor.

The researchers found more than eighty bones or pieces of bone from the same animal. The bones form one of the most complete known ape skeletons from the Miocene Epoch. That period began about twenty-two million years ago. It ended about five million years ago.

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Salvador Moya-Sola led the team that found the fossils. He says this marks the first time that a modern ape-like system of chest bones has been discovered. Mister Moya-Sola works for the Miquel Crusafont Institute of Paleontology in Barcelona, Spain. His team reported its findings in Science magazine.

The fossils were found near Barcelona. An earth-moving vehicle uncovered a tooth. Then the researchers found other bones from the head, chest, back, hands and feet of the ape-like creature. They named it Pierolapithecus catalaunicus (pyair-o-la-PITH-ee-cuss cat-a-LOON-ih-cuss).

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The researchers say the individual they uncovered probably was male and weighed about thirty-five kilograms. They say Pierolapithecus had firm bones in its lower back and could move its wrists in different directions. They say this made climbing possible. The creature also appears to have had teeth that could crush fruit.

The researchers say Pierolapithecus had shoulders like modern great apes, such as chimpanzees, gorillas and human beings. However, the shoulders are different from those of monkeys. Monkey shoulders are like those of dogs.

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Modern great apes are thought to have developed from Old World monkeys. The great apes then divided from lesser apes. That happened between eleven million and sixteen million years ago.

For many years, scientists have been attempting to find ancestors of the great ape that developed after this division. Skeletons of other ape-like animals were found. But they appear to have been less well developed than the newly-found fossils.

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The researchers say the lower back of Pierolapithecus is much like that of modern great apes. They say the head bones of the fossil and great apes also are similar.

Mister Moya-Sola says he believes Pierolapithecus lived in Africa in addition to what became Spain. He also says he believes this kind of animal probably first developed in Africa.

Scientists unconnected with the study have praised the findings. Other scientists said more studies are needed to satisfy questions about how great apes developed.

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VOICE TWO:

A Swedish study suggests that people who use cellular phones for at least ten years might be at greater risk for developing a rare, non-cancerous tumor. These tumors are called acoustic neuromas. They grow on the nerve that leads from the inner ear to the brain. The risk was higher on the side of the head where the phone was usually held.

Acoustic neuromas affect fewer than one in one hundred thousand people a year. They grow slowly and can take several years to be discovered. The tumor pushes on the surface of the brain, but does not grow into the brain itself.

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Researchers at the Karolinska Institute in Stockholm, Sweden, led the study. It was published in the International Journal of Epidemiology.

The study involved seven hundred fifty Swedes. About one hundred fifty of them had acoustic neuromas. About six hundred other people did not. Researchers asked all of the people about their cell phone use.

The researchers found that those people who had used cell phones for at least ten years had almost two times the risk of developing acoustic neuromas. Also, the tumor risk was almost four times higher on the side of the head where the phone was usually held. There was no increased risk for those who had used cell phones for fewer than ten years.

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At the time the study was done, only analog phones had been in use for ten years. Almost all early analog cell phones released more electromagnetic radiation than the digital phones now being sold. But researchers say they cannot be sure if the results are just linked to the use of analog phones. They say additional study is needed.

Earlier experiments have shown radiation from cellular phones can affect brain cells in a laboratory. But studies on people found no evidence that the phones present a health risk. However, experts say children should avoid using the phones for long periods because their brains are still developing.

The study is part of a research program known as the Interphone study. The World Health Organization's cancer research institute organized the research. It is attempting to learn if electromagnetic radiation from cell phones damages health. Final results of the study are to be released early next year.

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We recently received a message from a listener in Nepal. Lok Raj Joshi asks, "How can you define 'computer'?"

That is a big question. We immediately went to our computer. We asked the Google search engine for a definition. Answers appeared almost immediately. Many of the definitions were similar. They generally said a computer is an electronic device that executes the orders in a program. A computer stores, processes and provides information for users.

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There are several kinds of computers. Supercomputers are the fastest and most powerful. These computers carry out complex mathematical problems, mostly in connection with large systems. They are important for work including engineering design and weather science.

Supercomputers are rare and very costly. Personal computers are much more common. You will find them in someone's home or car. There are personal computers small enough to carry in your hand. People often use computers at work. They help people communicate and work together without having to be near each other.

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Computers can be linked together through a simple telephone line or through more complex wireless technology. One huge system of these connections is called the Internet. It includes the World Wide Web and electronic mail operations.

This communication system linked only about two-hundred computers in nineteen-eighty-one. In less than ten years, that number was hundreds of thousands. Today, experts say it is not possible to know exactly how many computers have Internet links. But, they say the estimates begin in the hundreds of millions.

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The Internet makes it possible for people to find information within seconds. Newspapers and magazines often have an Internet website. Organizations of all kinds also create their own websites.

Reporters use the Internet to help them write stories. Doctors use it to compare information about medical treatments. Teachers, farmers, and truckers also use the Internet. And, many people search the World Wide Web for non-work purposes.

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The Internet has led to changes in the way people live. Many people praise it as an open exchange for ideas and information. Yet government officials and industry experts have expressed concern about a lack of control over the Internet. Some groups protest sexual or violent images and writing placed on the World Wide Web. Other critics question the trustworthiness of information found through the Internet.

The Internet is surely part of any larger explanation of a computer. But maybe our listener in Nepal wanted a more personal definition. One well-known American recently wrote that his hope for the future of computers has never been greater. Microsoft founder Bill Gates wrote that he expects computing to change how people live, work, learn and are entertained as deeply in the next twenty-five years as in the last.

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VOICE TWO:

This program was written by Cynthia Kirk, Jerilyn Watson, and Caty Weaver. Cynthia Kirk was our producer. And, our engineer was Dwayne Collins. I'm Bob Doughty.

VOICE ONE:

And I'm Faith Lapidus. Join us again next week for Science in the News in VOA Special English.

  原文地址:http://www.tingroom.com/voa/4/science/17809.html