VOA慢速英语 2007 1023b（在线收听）

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

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Researchers believe cello music can help improve communications skills
And I'm Pat Bodnar.  This week, we will tell about a new finding about the value of musical training.  We will also tell how a short rest during the day can help your heart.  And, we tell about an American law that protects all kinds of plants and wildlife. 

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American scientists say musical training seems to improve communication skills.  They found that developing musical skills involves the same process in the brain as learning how to speak.  The scientists say that could help children with learning disabilities.

Nina Kraus is a neurobiologist at Northwestern University in Illinois.  She says musical training involves putting together different kinds of information.  She says the process involves hearing music, looking at musical notes, touching an instrument and watching other musicians.  She says the process is not much different from learning how to speak.  Both involve different senses.

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Professor Krauss says musical training and learning to speak each make us think about what we are doing.  She says speech and music pass through a structure of the nervous system called the brain stem.  The brain stem controls our ability to hear. 

Until recently, experts have thought the brain stem could not be developed or changed.  But Professor Krauss and her team found that musical training can improve a person's brain stem activity.  Their study was reported in the Proceedings in the National Academy of Sciences. 

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The study involved individuals with different levels of musical ability.  They were asked to wear an electrical device that measures brain activity.  The Individuals wore the electrode while they watched a video of someone speaking and a person playing a musical instrument -- the cello.  Professor Krauss says cellos have sound qualities similar to some of the sounds that are important with speech. 

The study found that the more years of training people had, the more sensitive they were to the sound and beat of the music.  Those who were involved in musical activities were the same people in whom the improvement of sensory events was the strongest. 

Professor Kraus says the study shows the importance of musical training to children with learning disabilities.  She says using music to improve listening skills could mean they hear sentences and better understand facial expressions. 

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Medical experts say most Americans do not get enough sleep.  They say more Americans need to rest for a short period in the middle of the day.  They are advising people to sleep lightly before continuing with other activities. 

One study earlier this year found that persons who sleep for a few minutes during the day were less likely to die of heart disease.  The study followed more than twenty-three thousand Greek adults for about six years.  Adults who rested for half an hour at least three times a week had a thirty-seven percent lower risk of dying from heart disease than those who did not nap. 

Study organizers said the strongest evidence was in working men.  The organizers said naps might improve health by reducing tension caused by work.

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Some European and Latin American businesses have supported the idea of napping for many years.  They urge people to leave work, go home and have a nap before returning.  In the United States, some companies let workers rest briefly in their offices.  They believe this reduces mistakes and accidents, and also increases the amount of work a person can do.

Sleep experts say it is likely that people make more mistakes at work than at other times.  They say people should not carry out important duties when they feel sleepy.  And they say the best thing to do is to take a nap.  About twenty minutes of rest is all you need.  Experts say this provides extra energy and can increase your effectiveness until the end of the day.

But experts warn that a nap should last no more than twenty to thirty minutes.  A longer nap will put the body into deep sleep.  Waking up will be difficult.

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Scientists have known for years that human life on Earth depends on the continued survival of many different kinds of plants, animals and other organisms.  That is one reason why governments make laws to protect the environment. 

In the United States, a major environmental law is the Endangered Species Act of Nineteen Seventy-Three.  Earlier laws provided only limited ways to protect native animals considered in danger. 

A conference in nineteen seventy-three led to a treaty that restricted international buying and selling of plants and animals believed to be harmed by trade.  Later that year, the United States Congress approved the Endangered Species Act. 

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The law expanded America's list of threatened animal species to include foreign animals.  It defined the words endangered and threatened.  The law extended protection to plants and other organisms.  It also required federal agencies to carry out programs to help guarantee the survival of endangered and threatened species.  Federal agencies were also barred from taking any step that would harm a listed species or destroy or change its living area.

The United States Fish and Wildlife Service calls the Endangered Species Act one of the most far-reaching wildlife conservation laws ever approved.  Its purpose is to protect endangered and threatened species and their environments.  It also requires the government to take action to help such species.

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To get this protection, a plant or animal species must be added to the Federal list of wildlife and plants said to be in the greatest need of help.  Each species is listed as either endangered or threatened.  The two words describe two levels of threat.  An endangered species is one that is close to disappearing from all or much of its living area.  One that is threatened will likely become endangered if nothing is done.

A species is added to the list when scientists have confirmed that its survival is threatened.  The threats may include the destruction of its environment, disease and too much hunting or fishing.

Government action is taken within one year of the proposal.  The final listing of each proposed species may be published, withdrawn or extended. 

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After a species has been added to the list, it can receive government protection.  This includes prevention of harmful activities and restrictions on taking, transporting or selling a species.  Officials say they want to increase the population of the listed species to a level where federal protection is no longer required.

One recent success story took place earlier this year.  In June, the Department of the Interior announced that it was removing the bald eagle from the list. 

 
Federal protection has helped the bald eagle population increase in the United States
Officials say the bald eagle was one of the first species protected under the Endangered Species Act.  But action was taken to help it much earlier.  Beginning in nineteen-forty, federal laws made it illegal to kill a bald eagle.  But continued use of the insect poison DDT after World War Two made the birds' eggs unable to produce young.  This reduced the number of bald eagles in the wild.

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The government banned the use of DDT in nineteen seventy-two.  And federal agencies began other efforts to save the bald eagle.  The results were so good that in nineteen ninety-five, officials lowered the threat level for the bald eagle from endangered to threatened.

In nineteen sixty-three, only four hundred seventeen breeding pairs of bald eagles were known to exist in the lower forty-eight United States.  Each breeding pair consisted of a fully-grown male and a female.  Today, the forty-eight states are home to more than nine thousand pairs.  Officials say the bald eagle in Alaska has never needed protection.  They say between fifty and seventy thousand bald eagles live there.

The bald eagle will continue to enjoy federal protection under the Bald Eagle Protection Act of Nineteen Forty.  That law makes it illegal to kill, sell or in any other way hurt eagles, their nests or eggs.  But American officials say they are now sure about the future security of the bald eagle.

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VOICE ONE:

This SCIENCE IN THE NEWS was written by SooJee Han and Nancy Steinbach.  Brianna Blake was our producer.  I'm Bob Doughty.

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And I'm Pat Bodnar.