VOA慢速英语2009-SCIENCE IN THE NEWS - Scientists Say Arctic Ice(在线收听

VOICE ONE:

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

VOICE TWO:

And I'm Faith Lapidus. This week, we will tell about ice loss in the Arctic Sea. We also will tell about a campaign to improve treatment of snakebites. And we report on an effort to save wild lions in Africa.

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VOICE ONE:
 
Scientists say melting Arctic Sea ice threatens native animals

American scientists say ice covering the Arctic Sea continued to shrink last winter. The scientists say they recently found that older, thicker sea ice was increasingly replaced with new ice. The new ice is thinner and melts faster than the older ice.

The scientists work for the American space agency and the National Snow and Ice Data Center in Boulder, Colorado. The two government agencies have been studying Arctic Sea ice from space since nineteen seventy-nine. One of the scientists says the past six years have shown the lowest Arctic sea ice cover ever measured.

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The study found an average ice cover of about fifteen million square kilometers in March. That is seven hundred thirty kilometers above the record low set three years ago. But it represents a loss of about five hundred ninety thousand kilometers from the yearly average between nineteen seventy-nine and two thousand.

Scientists say ninety percent of all Arctic sea ice is only one or two years old. This is up from forty to sixty percent in the nineteen nineties. The newer ice, experts say, is less resistant to melting during the summer months.

VOICE ONE:

The amount of ice cover and its thickness are two measures of the health of the Arctic Sea. Arctic sea ice is important because it throws sunlight back into space, keeping the sea cold. The ice also cools the air. But when the ice melts, the sun warms ocean waters.

Walter Meier is a scientist with the National Snow and Ice Data Center. He says a warmer Arctic and thinner sea ice changes the balance between the normally cold Arctic and warmer areas. He says changes to the ice cover also affect Arctic wildlife and people who depend on the local environment. The melting has already threatened native animals like the polar bear. Arctic melting could also affect Earth's climate.

Professor Meier also says the possibility of ships being able to move through newly unfrozen parts of the Arctic could lead to losses of natural resources. He says the competition this could create may also threaten international security.

VOICE TWO:

The study follows a separate report by the United States Oceanic and Atmospheric Administration and the Joint Institute for the Study of Atmosphere and Ocean. That study used computers and current ice-level information to predict future ice levels. The findings predicted that most of the Arctic's summer ice could disappear in thirty years.

Parts of Antarctica are also believed to be melting because of climate change. Satellite images show an ice bridge that held a huge Antarctic ice shelf in place recently broke apart.

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VOICE ONE:
 
Laboratory workers in Costa Rica collect venom from a highly poisonous fer-de-lance snake. The venom is used to make a treatment for the snake's bite.

More than four million people around the world are bitten by snakes each year. At least one hundred twenty-five thousand of these people die. Almost three million others are seriously injured. Doctors and researchers say the world does not provide enough good treatment for poisonous snakebites. To help improve the situation, experts have formed a project called the Global Snakebite Initiative.

Poisonous snakebites are common in rural areas of many developing countries with warm climates. Many victims are agricultural workers and children in Asia and southern Africa. Shortages of antivenom medicines, the treatment for snakebite, are common there. Existing supplies may not be high quality or developed correctly for local needs.

VOICE TWO:

Ken Winkel directs the University of Melbourne's Australian Venom Research Unit. He and university scientist David Williams are among the organizers of the Global Snakebite Initiative. Other project leaders are from Britain, Brazil, Sri Lanka, Costa Rica and Singapore.

The International Society of Toxinology supported the Initiative at the recent World Congress of Plant, Animal and Microbial Toxins in Recife, Brazil.

Doctor Winkel says antivenom treatment is too costly for many poor people who need it most. The drugs are developed from the venom of poisonous snakes.

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The Global Snakebite Initiative is working to increase the availability of good quality antivenom treatments and improve medical training for patient care. Another goal is to help manufacturers of antivenom medicines improve their products.

The project also wants communities to learn about snakebites and first aid. It wants more research and reporting systems. And it aims to help national health officials choose antivenoms for their countries' special needs.

The antivenom that cures the bite of one kind of snake may not be effective for another kind of snake. And the medicines for a cobra bite in the Philippines may not work for someone bitten by a similar snake in West Africa.

Experts look forward to improvements in worldwide treatment for snakebite. But they say the best ways to reduce death and injury from snakebites are education and prevention.

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VOICE TWO:
 
A male lion in the Masai Mara game reserve in Kenya

Up to two hundred thousand lions lived in Africa twenty years ago. Today, fewer than thirty thousand lions live there, many in protected areas. But environmental activists are working to save the animals. And, the activists have some unexpected helpers.

Members of the Maasai people have stopped killing lions and now are protecting them. Maasai herders care for cattle, sheep and goats on the Mbirikani Group Ranch. This community-owned ranch is in southeastern Kenya. It covers more than one hundred twenty one thousand hectares.

Maasai warriors in their late teenage years, twenties and early thirties are called murran. The murran normally gain fame and honor if they kill a lion. But some of them now defend the animals and work to keep them alive. The murran are called Lion Guardians. They are part of a scientific and environmental-protection group called Living with Lions.

VOICE ONE:

The Lion Guardians help herders find lost sheep, goats and cows. They observe the movement of lions and warn herders of their presence. Sometimes the guardians intervene and break up lion-hunters.

If a lion does kill a herd animal, the Maasai receive money from a program that repays herders for losses. The program has lessened the traditional conflict between herders and lions.

The murrans can follow a lion for hours without needing to drink water. They also learn radio work. That knowledge helps them find lions wearing radio collars. Scientists place the devices around the lions' necks so they can follow their movements.

Some guardians also learn to read and write so they can keep records of their work. Others keep records using pictures.

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The Lion Guardians have been facing an especially difficult situation in recent times. Herders in Kenya are suspected of killing lions with a pesticide product, Furadan. They reportedly pour the product on dead animals that lions eat. Furadan makes the lions unable to move, then causes a painful death.

Laurence Frank is a lion expert with the University of California at Berkeley. He says up to seventy-five wild Kenyan lions may have died this way during the past five years. Professor Frank heads the Living with Lions group.

In reaction to protests, the manufacturer of Furadan stopped all sales of it in Kenya. But environmental activists worry that the pesticide is already in stores and people's homes. Farmers use it to protect crops from insects, worms and mites.

VOICE ONE:

African lions are also threatened by human expansion into areas that once were wild lion country. Other enemies are hunters who kill lions for their body parts. The parts are then used in traditional medicines and souvenirs.

And, diseases sometimes kill large numbers of lions. Infectious animal tuberculosis, for example, has established itself as a threat to lions in southern Africa. Researchers also blame long periods of dry weather and heavy rain. Some scientists say climate change makes this worse.

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VOICE TWO:

This SCIENCE IN THE NEWS was written by Jerilyn Watson and Brianna Blake, who was also our producer. I'm Faith Lapidus.

VOICE ONE:

And I'm Doug Johnson. Transcripts, MP3s and podcasts of our programs are at voaspecialenglish.com. Join us again next week for more news about science in Special English on the Voice of America.

  原文地址:http://www.tingroom.com/voa/2009/5/76128.html