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VOICE ONE:
This is SCIENCE IN THE NEWS in VOA Special English. I'm Faith Lapidus.
VOICE TWO:
And I'm Bob Doughty. This week: a report that Antarctica is losing ice at an
increasing rate.
We also will tell about a bird with an excellent memory.
VOICE ONE:
But first, we tell about a study of special interest to women.
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Women who experience emotional tension in the first weeks of pregnancy may be
at greater risk of suffering a failed pregnancy. A new study suggests a link
between the tension, worry, and pressure a woman feels and her ability to carry
an unborn child, or fetus. The failure of a pregnancy and resulting death of the
fetus is called a miscarriage.
The results of the study were published in Proceedings of the National
Academy of Sciences of the United States of America.
VOICE TWO:
Pablo Nepomnaschy works for the National Institute of Environmental Health
Sciences in North Carolina. His research team studied sixty-one women for one
year. All the women lived in Guatemala and were already caring for at least one
baby.
The researchers tested the women for pregnancy and measured cortisol in their
liquid wastes. Cortisol is a substance, or hormone, produced by the body. Other
studies have linked it to emotional tension, also known as stress.
Twenty-two of the sixty-one women became pregnant during the study. The
researchers compared the pregnant women who had higher than normal cortisol
levels to those who did not. They found that women with the higher levels during
the first three weeks of pregnancy were nearly three times more likely to
miscarry.
VOICE ONE:
The researchers say a woman's body may recognize increased cortisol levels as
a sign that conditions are not right for pregnancy.
They also say other studies might have failed to find the link between stress
and miscarriages because they involved women who had been pregnant for at least
six weeks. Most miscarriages happen during the first three weeks of pregnancy.
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VOICE TWO:
An American study suggests that anger appears to increase your risk of
suffering an injury. It found that angry adults are more likely than other men
and women to suffer an injury requiring emergency medical care. Study organizers
say the risk of serious injury also is higher for men than for women.
Dan Vinson of the University of Missouri at Columbia led the research team.
They questioned more than two thousand people who had been treated in hospital
emergency rooms. The patients were asked to describe their emotions twenty-four
hours before the injury and then in the minutes just before their injury. The
answers were compared with those provided by a group of uninjured adults.
VOICE ONE:
Some of the patients described themselves with words such as excited, angry
and hostile. Patients who described themselves as feeling easily angered had a
thirty percent increased risk of suffering a serious injury. Among men, the risk
of injury increased one hundred percent if the man described himself as being
hostile or angry at himself.
The study also suggested a link between anger and sports injuries and
attacks.
VOICE TWO:
Professor Vinson and his team also examined suspected links between anger and
traffic injuries. But they were unable to find such a link. Professor Vinson
noted that some people get angry when they drive. Yet their actions generally do
not cause traffic accidents. An earlier study in Finland reached the same
finding.
Professor Vinson estimates that at least ten percent of emergency room visits
could be avoided if people did not take action when they are angry. He urged
doctors to begin recognizing when their patients have injured themselves because
of anger. He said doctors also may need to suggest anger control programs in
addition to medical treatment.
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VOICE ONE:
Two weeks ago on this program we talked about the melting of ice from
glaciers in Greenland. Now comes news that Antarctica is also losing ice at an
increasing rate. Science magazine published a new report. It says the Antarctic
ice sheet is losing as much as one hundred fifty-two cubic kilometers of ice
every year.
Scientific researchers from the University of Colorado in Boulder carried out
the study. They used information from a project called the Gravity Recovery and
Climate Experiment, or GRACE. Germany and the United States launched two GRACE
satellites in two thousand two. The satellites measure changes in Earth's
gravitational pull. Changes in the power of that pull provide clues about the
mass of different areas on the planet.
VOICE TWO:
The GRACE satellites travel around the Earth sixteen times each day. One
follows the other always at a distance of two hundred twenty kilometers.
When the gravity field changes, so does the distance between the two
satellites. Equipment on the satellites can record a change in distance of as
small as one micron.
John Warh is a physics professor at the University of Colorado and a leader
of the study. He says the strength of the GRACE satellite equipment is that it
let scientists measure all of Antarctica at once.
VOICE ONE:
Antarctica contains almost seventy percent of the world's fresh water. The
continent is almost all ice. In some areas that ice is close to two thousand
meters thick.
The last major study of the Antarctic ice sheet was completed in two thousand
one. Government scientists from several countries were involved. Those
scientists had expected a different future for the world's fifth largest
continent.
They said that Antarctica would gain ice mass in the future. They believed
that a warming of Earth's climate would lead to more rain and snow. The
scientists said more rain and snow would lead to increased ice. But, the new
report shows that is not happening. Or at least not yet.
VOICE TWO:
Some scientists argue that the new study is too early in the life of GRACE.
They say three years of measurement of the ice mass is not long enough.
Isabella Velicogna was the lead writer of the report. She is a researcher at
the University of Colorado and the Jet Propulsion Laboratory in Pasadena,
California. Mizz Velicogna says this is the first study to report a decrease in
a total mass balance of Antarctica. She agrees that more information from GRACE
would provide a clearer picture of the continent's future. But she also says she
does not think the ice loss she discovered is going to stop right away.
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VOICE ONE:
If you think the elephant is the only animal that never forgets, you are
wrong. That is the judgment of scientific researchers who studied a very small
North American bird. The researchers reported that hummingbirds can remember
visits to at least eight different areas over several days. The results of their
study were published in Current Biology.
Many scientists think that only people had comparable abilities. Earlier
studies showed that some animals could remember an object or event. Those
animals could remember where they saw the object or event. But it is not clear
if they knew when they saw it.
VOICE TWO:
Timing is very important to a hummingbird. These birds collect a sweet
substance called nectar from flowers. If a hummingbird returns too soon to a
flower, it will not get more nectar. Or, if the bird waits too long for a first
visit, another hummingbird may get there first.
In the new study, Jonathan Henderson and Susan Healy of the University of
Edinburgh led an international research team. Its members tested three wild,
male rufous hummingbirds in the Rocky Mountains of Canada.
VOICE ONE:
The hummingbirds recognized eight different objects that looked like flowers.
The objects were put in the place where their usual feeders were kept. The
researchers refilled four of the objects. They said it took one to two hours to
train the birds to feed from them.
Every ten minutes, the researchers put a sweet substance in the four objects.
The researchers filled the four other objects every twenty minutes.
The hummingbirds demonstrated that they could remember the placement of these
man-made flowers. They also could remember when they had last visited them. The
hummingbirds returned to the flowers that were refilled more often than the
others.
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VOICE TWO:
SCIENCE IN THE NEWS was written by Brianna Blake, George Grow, Jerilyn Watson
and Caty Weaver.