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(单词翻译:双击或拖选)
VOICE ONE:
This is SCIENCE IN THE NEWS in VOA Special English. I'm Barbara Klein.
VOICE TWO:
Scientists are bringing the Dead Sea Scrolls1 to the Internet
And I'm Steve Ember. This week, we will tell about an effort to place two thousand year old documents on the Internet. We will tell why two American scientists are concerned about frogs. And we tell about Down syndrome2 -- a disorder3 that has been noted4 in the American election campaign.
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VOICE ONE:
Israeli officials have announced plans to make the Dead Sea Scrolls available on the Internet. Officials say scientists have begun using space technology to take pictures of the scrolls. They say the technology will help uncover some writings that have been hidden for years.
The Dead Sea Scrolls are about two thousand years old. They include pieces from about nine hundred documents. The scrolls contain the oldest known copies of the Hebrew holy book or Bible. They also include descriptions of life for Jews and early Christians5 during the time of Jesus.
The scrolls were found near the Dead Sea in nineteen forty-seven. They are written on two kinds of paper: parchment or papyrus6. Some parts of the documents have become difficult to read over the years.
VOICE TWO:
The Dead Sea Scrolls are in the possession of the Israel Antiquities7 Authority. Last month, officials announced that all of the scrolls would be digitally copied and placed on the Internet. The scientists say they are using non-damaging, high-tech8 imaging technology. Infrared9 cameras were used to make pictures of the Dead Sea Scrolls not long after they were found. Since then, infrared technology has greatly improved.
Scientists say the new method will show never before seen details. Officials say the imaging process will be done in way that protects the documents from the harmful effects of light and heat.
VOICE ONE:
The imaging technology being used on the scrolls now has also been used in space. Scientist Greg Bearman is taking part in the project. Mister Bearman recently retired10 from the American space agency. He says the imaging equipment is used to study planets, but that it also works on the Dead Sea Scrolls.
Officials say the goal of the project is make the scrolls more widely available to researchers and the public. The work is expected to take about five years.
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VOICE TWO:
Two American scientists believe many kinds of wildlife life are in great danger. The scientists say these animals and plants could permanently11 disappear from Earth. They also say a widespread loss of amphibians13 in recent years shows that a biological disaster has begun.
Amphibians are land animals that reproduce in water. The scientists studied a well-known amphibian12 -- the frog. They found that some frog populations are only two to five percent of their normal size. David Wake and Vance Vredenburg reported the finding in the Proceedings14 of the National Academy of Sciences.
VOICE ONE:
Mister Wake teaches at the University of California at Berkeley. Mister Vredenburg works at the university's Museum of Vertebrate Zoology15 and teaches at San Francisco State University. Their joint16 observations represent almost fifty years of research.
The report says at least two hundred species, or kinds of life, have died out during the past twenty years. But the scientists are hopeful about some amphibians. They believe at least some will live through the current threat of extinction17.
Professor Wake says people are mainly responsible for conditions that threaten wildlife. He blames human beings for destruction of the animals' habitats or living areas. This often happens when unoccupied land is developed for human use.
VOICE TWO:
The men and their team did some of the research in the Sierra Nevada Mountains of California. Five of seven amphibian species at the top of the mountains are threatened.
The scientists walked along forty kilometers of streams and lakes to observe the frogs. Mister Vredenburg says one area -- Yosemite National Park -- is especially well protected. Yet its population of two kinds of frogs dropped sharply in recent years. Ninety-five to ninety-eight percent of the Sierra Nevada Yellow-legged Frog and the Southern Yellow-legged Frogs disappeared during that time.
VOICE ONE:
Professor Vredenburg says the frogs may have started disappearing in the nineteen nineties. At that time, people were adding rainbow trout18 to streams and lakes. The fish like to eat frog eggs and young frogs. When the trout were removed, the frogs stopped dying for a time.
Mister Vredenburg says they came back by the thousands, but later died off again. He says a few hundred yellow legged and Sierra frogs are alive today. That compares with many thousands in the past.
VOICE TWO:
The University of California team said the frogs died from an infection caused by a fungus19. This disease, chytridiomycosis, also has killed many other animals over the past five years. And it has spread to other species around the world.
It is not known how the disease is spread. Birds or wind may be responsible. But experts now have been able to complete a genetic20 map of the fungus. They hope to develop prevention methods within a year. Mister Wake notes that new kinds of animal and plant life have developed and died off over the centuries. Sometimes, however, an extinction event takes place. During this time, many more species die out permanently than develop. Mister Wake says humanity is living in the sixth great extinction event of history. He says human responsibility makes it different from the first five extinction events.
VOICE ONE:
Scientists disagree about when the present mass extinction began. Some say it may have started about ten thousand years ago. That is when humans began to hunt.
Many large mammals disappeared from Earth during that period. Or, Mister Wake said, it may have started in the nineteenth century, when the Industrial Revolution began. But he and Mister Vredenburg believe it already has started.
Mister Wake says amphibians have lived for two hundred fifty million years. He says they survived when dinosaurs21 did not. And he warns the fact that amphibians are dying out should send people an important message.
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VOICE TWO:
This month, the governor of Alaska, Sarah Palin, accepted the Republican Party's nomination22 for vice23 president. Governor Palin has a son who was born with Down syndrome. She and her husband also have four other children who do not have the disorder.
Human genes24 are normally organized along forty-six chromosomes26 -- twenty-three from each parent. But as a result of a mistake in cell division, some people have three copies of the twenty-first chromosome25. There are supposed to be just two.
About one in every seven hundred babies has this extra copy. A British doctor, John Langdon Down, first described the condition in the eighteen sixties.
VOICE ONE:
Many babies with Down syndrome have low muscle tone, so they need extra support when they are held. Their heads are smaller than average and they can have unusually shaped ears. Also, their eyes often point upward.
People with Down syndrome often have other symptoms. These include problems with their heart and with their breathing and hearing. But a lot of the problems are treatable.
As a result, people with Down syndrome are living longer. In nineteen eighty-three, they lived an average of just twenty-five years. Today the average life expectancy27 is fifty-six. But that longer life has led to a sad discovery. People with Down syndrome may have an increased risk for Alzheimer's disease at an early age. The disease slowly destroys memory, thinking and reasoning skills.
VOICE TWO:
Down syndrome is the most common genetic cause of mental retardation28. Most people with Down syndrome are mildly to moderately retarded29. Many are able to attend classes with other students. Later, as adults, many hold jobs and lead independent lives.
There are tests to look for Down syndrome during pregnancy30. The risk of it is higher for older mothers. The rate for those under thirty is one in one thousand births. In women age forty-four, like Governor Palin, that number is one in thirty-five.
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VOICE ONE:
This SCIENCE IN THE NEWS program was written by Jerilyn Watson, Caty Weaver31 and Brianna Blake, who was also our producer. I'm Barbara Klein.
VOICE TWO:
And I'm Steve Ember. Join us again at this time next week for more news about science in Special English on the Voice of America.
1 scrolls | |
n.(常用于录写正式文件的)纸卷( scroll的名词复数 );卷轴;涡卷形(装饰);卷形花纹v.(电脑屏幕上)从上到下移动(资料等),卷页( scroll的第三人称单数 );(似卷轴般)卷起;(像展开卷轴般地)将文字显示于屏幕 | |
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2 syndrome | |
n.综合病症;并存特性 | |
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3 disorder | |
n.紊乱,混乱;骚动,骚乱;疾病,失调 | |
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4 noted | |
adj.著名的,知名的 | |
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5 Christians | |
n.基督教徒( Christian的名词复数 ) | |
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6 papyrus | |
n.古以纸草制成之纸 | |
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7 antiquities | |
n.古老( antiquity的名词复数 );古迹;古人们;古代的风俗习惯 | |
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8 high-tech | |
adj.高科技的 | |
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9 infrared | |
adj./n.红外线(的) | |
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10 retired | |
adj.隐退的,退休的,退役的 | |
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11 permanently | |
adv.永恒地,永久地,固定不变地 | |
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12 amphibian | |
n.两栖动物;水陆两用飞机和车辆 | |
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13 amphibians | |
两栖动物( amphibian的名词复数 ); 水陆两用车; 水旱两生植物; 水陆两用飞行器 | |
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14 proceedings | |
n.进程,过程,议程;诉讼(程序);公报 | |
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15 zoology | |
n.动物学,生态 | |
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16 joint | |
adj.联合的,共同的;n.关节,接合处;v.连接,贴合 | |
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17 extinction | |
n.熄灭,消亡,消灭,灭绝,绝种 | |
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18 trout | |
n.鳟鱼;鲑鱼(属) | |
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19 fungus | |
n.真菌,真菌类植物 | |
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20 genetic | |
adj.遗传的,遗传学的 | |
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21 dinosaurs | |
n.恐龙( dinosaur的名词复数 );守旧落伍的人,过时落后的东西 | |
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22 nomination | |
n.提名,任命,提名权 | |
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23 vice | |
n.坏事;恶习;[pl.]台钳,老虎钳;adj.副的 | |
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24 genes | |
n.基因( gene的名词复数 ) | |
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25 chromosome | |
n.染色体 | |
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26 chromosomes | |
n.染色体( chromosome的名词复数 ) | |
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27 expectancy | |
n.期望,预期,(根据概率统计求得)预期数额 | |
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28 retardation | |
n.智力迟钝,精神发育迟缓 | |
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29 retarded | |
a.智力迟钝的,智力发育迟缓的 | |
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30 pregnancy | |
n.怀孕,怀孕期 | |
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31 weaver | |
n.织布工;编织者 | |
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