SCIENCE IN THE NEWS #2121 - Digest
By StaffThis is Bob Doughty.And this is Sarah Long with SCIENCE IN THE NEWS, a VOA Special English program about recent developments in science. Today, we tell about a new substitute blood product. We tell about the ice melting on the tallest mountain in Africa. We tell about a link between the hormone estrogen and ovarian cancer. And we tell about a new way to teach children about computers.South Africa has become the first country to approve a new blood substitute for use in humans. The product, called Hemopure, does the work of red blood cells. It transports oxygen to tissues throughout the body.
An American company called Biopure developed the new blood substitute. Company officials say they will ask for a permit to sell Hemopure in the United States later this year. The company also wants to sell its product in Europe and other areas. Hemopure is made from the blood of cows. The product comes from the part of the cow's red blood cell called hemoglobin.Health care workers can use Hemopure in blood transfusions. A transfusion is a process that transports blood into a person's blood system. People who lose large amounts of blood in accidents or operations often require transfusions. The blood for transfusions usually comes from healthy people who give some of their blood at medical centers. However, people with infectious diseases are not permitted to give blood. Experts note that the number of people permitted to give blood in many countries is decreasing as a result of diseases such as AIDS.South African officials approved Hemopure to treat patients who need operations and who suffer from acute anemia. People with acute anemia have blood that does not carry enough oxygen.
Richard Friedland is an official with Netcare, the company permitted to sell Hemopure in South Africa. He says the product will be widely marketed next year, after South African doctors have been trained to use it. Reports say Hemopure is expected to be especially useful in developing countries. Unlike real blood, Hemopure does not need to be kept cool. And it is safe to use for two years.
Doctor Friedland says Hemopure can be used in people with all kinds of blood types. So health care workers performing a transfusion will no longer need to find blood that is exactly the same as the patient's blood.Some people are concerned about Hemopure's use of blood from cows because of diseases like Mad Cow Disease. Doctor Friedland says the cows that are used are observed closely to make sure they are free of the disease. He also says the process to make the blood substitute removes all agents that could cause disease.
Other medical experts reportedly say the use of Hemopure will not replace all blood transfusions. They say the product is not a real substitute for blood. It does not contain all the important substances that blood does. But they say it is an effective temporary treatment until safe blood can be found.
((MUSIC BRIDGE))An American scientist says most of the ice on Africa's highest mountain has melted since the early twentieth century. Lonnie Thompson says the remaining ice on Mount Kilimanjaro in Tanzania could disappear within less than twenty years.
Mr. Thompson works at Ohio State University in Columbus, Ohio. He reported his research at a recent meeting of scientists in San Francisco, California. Mount Kilimanjaro is more than five-thousand-eight-hundred meters above a tropical forest. Mr. Thompson studied the mountain's icy top last year. Then he compared the results to earlier studies. He found that the glacier had lost thirty-three percent of its ice since Nineteen-Eighty-Nine. And it had lost eighty-two-percent of its ice since Nineteen-Twelve.In January, Mr. Thompson's team continued research in Tanzania. They measured areas where they had put measuring devices a year before. More than one meter of ice had melted in twelve months.
Mr. Thompson said the melting ice once fed bodies of water in Tanzania. But these rivers and streams are now dry. He said the melting ice on Kilimanjaro may decrease business from visitors. More than twenty-thousand people a year climb Kilimanjaro to experience ice on a mountain in Africa.Mr. Thompson and his team have done similar research on a mountain in Peru. They found large amounts of ice melting from a glacier in the Andes Mountains. The area of the ice measured fifty-six square kilometers in Nineteen-Seventy-Six. Today it is forty-four square kilometers. Mr. Thompson said this means the ice may melt completely within twenty years. He says the loss of ice might reduce the amount of water used for crops and to produce electric power in Peru.
Ice on mountains in warm areas normally melts slowly. Scientists say the melting of ice on mountains in Africa and Peru is an important sign of warming of the Earth.
((MUSIC BRIDGE))A recent medical study shows that a hormone many women use may increase their chances of getting cancer of the ovaries. Estrogen is a growth chemical produced by organs and tissue in a woman's body. The hormone causes the growth and development of female sexual organs. And it causes a woman to be able to become pregnant. Doctors give estrogen to older women whose reproductive period has ended. The treatment replaces estrogen that their bodies have stopped producing. Some older women take estrogen to keep their bones from weakening. Research also has shown that estrogen also may reduce the risk of some heart disease.A study published in the Journal of the American Medical Association shows that use of estrogen for many years may be harmful. Researchers studied more than two-hundred-thousand healthy older women for fourteen years. The study found that women who took estrogen for more than ten years were more than two times as likely to die of ovarian cancer as women who never took the hormone. The women who died had taken the hormone in the Nineteen-Seventies or early Nineteen-Eighties.
However, the doctor who led the study says taking the hormone for a short time is probably not harmful. Today, doctors give estrogen in smaller amounts. And estrogen is usually given with another hormone, progesterone, to control harmful effects.
((MUSIC BRIDGE))Everyone knows that technology is very important. More and more people make their living by working with computers. But educators around the world have a big problem. How are they going to teach millions of school children to use computers? A researcher in India has developed a possible solution to the problem. His name is Sugata Mitra. His believes that children can teach themselves how to use computers.
Mr. Mitra and engineers from a company called N-I-I-T in New Delhi invented a new kind of computer. It does not use a keyboard.
They put the computer in a wall that surrounds an area where poor people live. The computer was connected to the Internet. Mr. Mitra wanted to see if people would use the computer. He placed a video camera near the computer so he could watch people as they looked at or played with the computer.He discovered that adults were not interested in the computer in the wall. But children, especially young boys, were very interested. They learned how to play games and find music on the Internet without any adult to teach them. Then they shared what they had learned with other children. These children did not speak or read English, only Hindi. However, they were able to use computer programs in English to find interesting games on the Internet. And they were able to make the games work.
This SCIENCE IN THE NEWS program was written by George Grow, Jerilyn Watson, Mario Ritter and Gary Garriott. It was produced by George Grow. This is Sarah Long.And this is Bob Doughty. Join us again next week for more news about science in Special English on the Voice of America.