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.
(THEME)
VOICE ONE:
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.
VOICE TWO:
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.
VOICE ONE:
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.
VOICE TWO:
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.
(MUSIC BRIDGE)
VOICE ONE:
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.
VOICE TWO:
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.
VOICE ONE:
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.
VOICE TWO:
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.
VOICE ONE:
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.
(MUSIC BRIDGE)
VOICE TWO:
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.
VOICE ONE:
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.
VOICE TWO:
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.
(THEME)
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.
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This Science Report is published courtesy
of VOAnews.com
