VOA慢速英语 2007 0306b(在线收听

VOICE ONE:

This is SCIENCE IN THE NEWS in VOA Special English. I'm Doug Johnson.

VOICE TWO:


David Massey, a student at the West Virginia Autism Training Center at Marshall University, works with Stephanie Hurley, a Marshall senior. New findings about the possible causes of autism appear below.

And I'm Steve Ember. This week, we will tell you what an American satellite discovered under Antarctica. We will also tell about the first woman to win a major award for computer scientists. And, we report on a study that found yet another possible use for the drug aspirin.

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American space agency scientists say they have discovered large lakes hidden under the ice in Antarctica. The lakes are said to quickly fill with water and empty into surrounding seas.

Research scientists say they found more than one hundred lakes under the West Antarctic Ice Sheet. Until now, scientists did not know many of these lakes existed. Knowing that they exist will help scientists better understand the effects of climate change on the ice sheet.

The ice above the lakes moves at a speed of about eight tenths of a meter each day. Fast-moving ice streams are one way to estimate climate change. Information from the ice streams can be used to estimate how ice will survive rising sea temperatures.

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The researchers say they do not know exactly how the underground lakes affect the melting of ice away from the Antarctic ice sheet. Yet the melting of the ice sheet is one of the greatest fears of climate change scientists. American space agency researchers say Antarctica alone holds about ninety percent of the world's ice. They say the continent also holds seventy percent of the Earth's fresh water.

The Intergovernmental Panel on Climate Change recently released a report about climate change. The group warned that melting ice could cause world sea levels to rise up to fifty-eight centimeters by the end of the century.

VOICE ONE:

The discoveries were announced last month at the American Association for the Advancement of Science meeting in San Francisco, California.

Satellite images discovered the lakes under about seven hundred meters of ice. The satellite information was gathered from two thousand three to two thousand six. In the past, scientists had to cut deep holes into Antarctic ice to learn about what was happening underneath. The process only permitted them to study small areas at a time.

VOICE TWO:

The ice streams on top of the lakes move quickly. Scientists say they move about one and one-half meters each day and often drop ice into the sea. Currently, about twelve ice streams are moving the edges of the West Antarctic Ice Sheet into nearby waters.

Experts say the ice sheet last melted about one hundred twenty five thousand years ago. At the time, Earth's surface temperatures were similar to current temperatures. The American space agency estimates that the moving of ice into the ocean at the time sent sea levels about eighteen feet higher.

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VOICE ONE:

An American study shows that use of the drug aspirin may prevent healthy adults from developing the disease asthma. Asthma is caused by a condition in the lungs. During an asthma attack, breathing passages become smaller, blocking the flow of air. The disease usually develops during childhood. Some children recover as they get older.

Tobias Kurth led the new study. He works for Brigham and Women's Hospital in Boston, Massachusetts. His team studied information about twenty-two thousand male doctors. The doctors had taken part in a health study during the nineteen eighties. That study was about heart disease, but its records also had information about asthma.

VOICE TWO:

None of the doctors had asthma when the study began. Half of them took an aspirin every other day. The other half took a harmless substance called a placebo.

After about five years, one hundred forty-five men in the placebo group had developed asthma. But only one hundred thirteen men in the aspirin group had the disease. This represented a twenty-two percent decrease in the risk of developing asthma for those taking aspirin.

The research team reported the results last month in the American Journal of Respiratory and Critical Care Medicine.

The researchers say it is too early to suggest that people take aspirin to prevent asthma. They also say aspirin is not a treatment for asthma. The drug can cause asthma attacks in some people who have the disease.

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VOICE ONE:

Another study offers information about the possible genetic causes of autism. Scientists already believed that autism is passed from parents to their children. But the study shows there could be many genes responsible for the brain disorder. This is different from other disorders that are caused by a single gene.

Results of the study were reported last month in the publication Nature Genetics. The Autism Genome Project organized the study. The project involves research scientists in nineteen countries. The researchers compared genetic material from almost twelve hundred families. Each family had two or more children with autism.

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The researchers used what they called gene chip technology to look for small genetic differences that could be linked to the disorder. They identified a gene called neurexin-one as one possible cause of autism. This gene seems to be linked to communication among brain cells. The study also showed that an area of chromosome eleven might influence the development of autism.

Signs of the disorder appear in early childhood, usually by the age of two or three years. Autism affects four times as many boys as girls. Another study released last month suggests that as many as one in every one hundred and fifty children in the United States has an autism disorder.

VOICE ONE:

Autistic children have problems in the development of social and communication skills. They may also have limited interests and repeat the same actions again and again.

One problem with earlier autism research has been that studies are often based on information from a small number of people. In this study, more than one hundred and twenty researchers spent five years working to expand the number of persons studied. Because they shared their information, the researchers had a greater amount of information to work with.

Scientists hope that learning more about the genetic roots of autism will help them to better identify and understand the disorder. They also hope to learn more about developing drugs to treat autism.

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Frances Allen is the first woman to win the Turing Award

Finally, a computer scientist from the United States has won the two thousand six A.M. Turing Award. The Association for Computing Machinery named Frances Allen as the winner. The A.C.M. is an international organization for computer scientists and educators.

The A.M. Turing Award has been called the Nobel prize of computing. It is given every year to scientists and engineers who created the systems and theories that have aided the information technology industry. The Turing Award winner receives one hundred thousand dollars. Earlier winners include Vinton Cerf and Robert Kahn for helping to design the Internet.

The award is named for the British mathematics expert Alan M. Turing. He is considered one of the fathers of computer science. His work helped Allied nations learn how the German military passed secret commands and orders during World War Two.

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This is the first time that the Turing Award has been given to a woman. The Association for Computing Machinery says it is honoring Frances Allen for improving the performance of computer programs in solving problems. It says her work also helped to speed up the use of high performance computing.

Miz Allen is retired from her job with the T.J. Watson Research Center at IBM Corporation. She joined the company in nineteen fifty-seven to teach the computer language FORTRAN to IBM engineers. She was trained as a mathematics teacher but became interested in the power of computers.

Miz Allen has won several awards and honorary college degrees. She told the USA Today newspaper that she wants to use the Turing Award to influence more young women to study computer science. She will receive her award in June at ceremonies in San Diego, California.

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This SCIENCE IN THE NEWS program was written by Brianna Blake, Dana Demange, Shelley Gollust and Nancy Steinbach. Brianna Blake was our producer. I'm Steve Ember.

VOICE ONE:

And I'm Doug Johnson. Be listening again next week at this time for more news about science in Special English on the Voice of America.
  原文地址:http://www.tingroom.com/voa/2007/3/40074.html