VOICE ONE:
This is SCIENCE IN THE NEWS in VOA
Special English. I'm Barbara Klein.
VOICE TWO:
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 syndrome -- a disorder that has been noted 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 Christians 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 papyrus.
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 Antiquities 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-tech imaging
technology. Infrared 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 retired 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 permanently disappear from Earth. They also say a widespread loss of
amphibians in recent years shows that a biological disaster has begun.
Amphibians are land animals that
reproduce in water. The scientists
studied a well-known amphibian -- 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 Proceedings 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 Zoology
and teaches at San Francisco State University.
Their joint 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
extinction.
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 trout 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
fungus. 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 genetic 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 dinosaurs 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 nomination for vice
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 genes are normally organized along
forty-six chromosomes -- twenty-three from each parent. But as a result of a mistake in cell
division, some people have three copies of the twenty-first chromosome. 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 expectancy 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 retardation. Most
people with Down syndrome are mildly to moderately retarded. 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 pregnancy. 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 Weaver 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.