VOICE ONE:
This is Steve Ember.
VOICE TWO:
And this is Bob Doughty with SCIENCE IN THE NEWS, a VOA Special English program about recent developments in science. Today, we tell about this year’s Nobel Prizes for medicine, physics and chemistry.
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The Nobel Prizes for medicine, physics and chemistry were announced in Sweden earlier this month. The Nobel Prizes are the world’s most important honors for scientific work. The awards will be presented at ceremonies in Stockholm December tenth. The winners for each prize will share one-million dollars.
The Nobel committee at the Karolinska Institute is giving the Nobel Prize in Physiology or Medicine to three scientists. Two are British. One is Sydney Brenner of the Salk Institute for Biological Studies in La Jolla, California. The other is John Sulston of the Wellcome Trust Sanger Institute in Cambridge, England. The third winner is American scientist Robert Horvitz of the Massachusetts Institute of Technology in Cambridge.
The three men will share the Medicine Prize for their discoveries of how healthy cells carry orders to kill themselves. The discoveries involve a process called programmed cell death. Programmed cell death is necessary for tissue and organ development. It also influences the development of many diseases.
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All three scientists made discoveries with an organism called C. elegans. Forty years ago, Sydney Brenner wanted to study how genes and cells are connected in complex animals. Yet the size of complex animals limited his work. So he proposed studying a soil worm, called C. elegans. The worm is only about one millimeter long. It has a clear skin and reproduces quickly. Scientists can watch its cells divide under a microscope.
Doctor Brenner showed that a chemical could produce changes in the genes of C. elegans. He found that different changes could be linked to several genes and to effects on organ development.
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John Sulston developed methods to study cell division in C. elegans. He explained the process by which a fertilized egg develops into an adult organism. In nineteen-seventy-six, he described this process for part of the worm’s nervous system.
Doctor Sulston showed that some cells in C. elegans are designed to die through programmed cell death. He discovered that cells divided more often than appeared necessary to make an adult organism. This led him to believe that some cells have genetic orders to die as part of their development.
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Robert Horvitz used C. elegans to discover the existence of a genetic program that controls cell death. In a series of experiments, he identified two genes required for cells to die. Later, he showed that another gene protects against cell death. He also identified genes that direct how the dead cell is removed.
The Nobel committee said the three men’s work has made it possible to identify genes with similar controls in humans. The committee said their work has helped scientists better understand how cancer and many other diseases develop.
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The Nobel Prize in Physics this year also has three winners. The Royal Swedish Academy of Sciences praised their work in astrophysics, the physics of objects in space. It said the work has increased understanding of the universe.
American Raymond Davis and Masatoshi Koshiba of Japan were honored for experiments that confirmed the existence of mysterious particles known as neutrinos. Neutrinos are formed in the sun and other stars when hydrogen gas changes into helium. However, neutrinos rarely react with other substances. As a result, scientists have had great difficulty confirming their existence.
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Raymond Davis of the University of Pennsylvania in Philadelphia was the first person to measure neutrinos from the sun. In the nineteen-sixties, he started work on a project to prove they exist. He placed a huge container underground in a gold mine in South Dakota. He filled the tank with six-hundred-fifteen metric tons of cleaning fluid.
Mister Davis estimated that about twenty neutrinos would react with the chlorine in the cleaning fluid every month. This meant that twenty atoms of the chemical argon would be created. He developed a method to identify these atoms and measure their number.
The American scientist collected information from his experiment until nineteen-ninety-four. By then, about two-thousand argon atoms were discovered in the tank. He used control experiments to show that no argon atoms were left in the chlorine.
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Masatoshi Koshiba of the University of Tokyo confirmed Mister Davis’s results. He and his team built another huge tank to measure neutrinos. It was placed deep in a mine in Japan. However, Mister Koshiba used a different liquid: water. The reaction of neutrinos with the water released electrons that produced bursts of light. He recorded the direction of the bursts of light. He was able to show for the first time that neutrinos came from the sun.
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The other half of the Nobel Physics Prize went to Riccardo Giacconi of Associated Universities, Incorporated, in Washington, D-C. He was the first scientist to discover X-ray radiation from areas outside our solar system. The Swedish Academy praised his work in experiments that resulted in new images from space.
In nineteen-fifty-nine, Riccardo Giacconi began designing rocket-launched telescopes that could measure X-rays from the Sun. His first successful experiment discovered X-rays in the Scorpio star system.
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Since then, scientists have developed more modern X-ray telescopes to discover black holes and other stars. Those instruments have used versions of Mister Giacconi’s method.
The Italian-born American scientist also helped to develop a satellite to study the sky for radiation. He also built an X-ray telescope that could provide detailed images. It has made a large number of discoveries.
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Scientists from the United States, Japan and Switzerland won the Nobel Prize for Chemistry. The Royal Swedish Academy praised them for developing ways to identify and study the structure of large biological molecules such as proteins.
One winner is American John Fenn of Virginia Commonwealth University in Richmond. Another winner is Koichi Tanaka of the Shimadzu Corporation in Kyoto, Japan. The Swedish Academy praised their work in improving a process called mass spectrometry to study large protein molecules.
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Mass spectrometry lets scientists quickly identify substances such as proteins. The process has been used in tests for illegal drugs or other substances. It has been used on small and moderate-sized molecules for much of the twentieth century. Mister Fenn and Mister Tanaka were honored for finding two ways to extend the process to larger molecules.
The American scientist demonstrated a way to change proteins into a gas without losing their structure. He used a strong electrical field to spread electrically-charged particles containing the proteins. The particles explode into smaller particles. Then, the smaller particles explode into even smaller ones. Finally, only an electrically-charged protein remains.
Mister Tanaka showed that low levels of laser light could change the proteins without breaking them apart. He was the first person to demonstrate that laser technology could be used for large biological molecules.
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Kurt Wuethrich of the Swiss Federal Institute of Technology in Zurich, Switzerland will also receive the Nobel Chemistry Prize. He was honored for improving a process called nuclear magnetic resonance. N-M-R providess information on the three-dimensional structure and scientific qualities of molecules.
Mister Wuethrich developed an idea about how N-M-R could be extended to include biological molecules, such as proteins. He invented a method of identifying areas in the protein molecule. He also proposed a way to measure the distances between these areas. This method is called sequential assignment. Today, it is a necessary part of all N-M-R structural investigations.
The Nobel committee says all three men have helped to show how proteins operate in cells. It says this has led to a better understanding of life processes and aided the development of new medicines.
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VOICE ONE:
This SCIENCE IN THE NEWS program was written and produced by George Grow. This is Steve Ember.
VOICE TWO:
And this is Bob Doughty. Join us again next week for more news about science in Special English on the Voice of America.