VOA慢速英语2009年-SCIENCE IN THE NEWS - Study Shows Lone（在线收听）

VOICE ONE:

This is SCIENCE IN THE NEWS in VOA Special English. I'm Bob Doughty.

VOICE TWO:

And I'm Shirley Griffith. This week, we will tell how people who are lonely can spread that feeling to others. We will tell about an experimental treatment for a birth defect. And, we will tell about efforts to create new weapons against the disease malaria.

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A newly-published study has shown that loneliness can spread from one person to another, like a disease.

Researchers used information from the Framingham Heart Study, which began in nineteen forty-eight. The Framingham study gathers information about physical and mental health, personal behavior and diet. At first, the study involved about five thousand people in the American state of Massachusetts. Now, more than twelve thousand individuals are taking part.

Information from the Framingham study showed earlier that happiness can spread from person to person. So can behaviors like obesity and the ability to stop smoking.

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University of Chicago psychologist John Cacioppo led the recent study. He and other researchers attempted to show how often people felt lonely. They found that the feeling of loneliness spread through social groups.

Having a social connection with a lonely person increased the chances that another individual would feel lonely. In fact, a friend of a lonely person was fifty-two percent more likely to develop feelings of loneliness. A friend of that person was twenty-five percent more likely. The researchers say this shows that a person could indirectly be affected by someone's loneliness.

The effect was strongest among friends. Neighbors were the second most affected group. The effect was weaker on husbands and wives, and brothers and sisters. The researchers also found that loneliness spread more easily among women than men.

VOICE ONE:

The new study involved researchers from the University of Chicago, Harvard University and the University of California at San Diego.

A report on the findings was published this month in The Journal of Personality and Social Psychology.

The New York Times newspaper reports that, on average, people experience feelings of loneliness about forty-eight days a year. Yet the study found that having a friend who is lonely can add about seventeen days a year of loneliness. It also found that every additional friend can decrease loneliness by about five percent, or two and a half fewer lonely days.

VOICE TWO:

Loneliness has been linked to health problems like depression and sleeping difficulties. The researchers believe that knowing the causes of loneliness could help in reducing it.

The researchers did not study how loneliness spreads. However, Professor Cacioppo says existing research offers some possibilities. Lonely people are often mistrustful of others. This behavior spreads from one person to another, along with the emotion responsible for it.

The study suggests that people can take steps to stop the spread of loneliness. They can do this by helping individuals they know who may be experiencing loneliness. The result can be helpful to the whole social group.

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Baby with a cleft lip

Researchers at the University of Southern California say they have found a way to heal a birth defect in animals before they are even born. A team from the U.S.C. School of Dentistry described its experiments in the publication Development.

Cleft palate and cleft lip are two of the most common birth defects in human beings. They can affect up to one in seven hundred babies around the world. Cleft lip is a separation in the upper lip. It can be a small or large opening that reaches up to the nose. Cleft palate is a separation in the top of the mouth.

VOICE TWO:

Cleft abnormalities usually develop early in pregnancy. They also are quickly recognized at birth. Many babies with cleft lip or palate have difficulty feeding. Other concerns include an increased risk of ear infection, hearing loss and problems with their teeth. Older children with cleft may have problems speaking.

Doctors can perform a surgical operation to repair either abnormality after the baby is born. The surgery can sometimes be complex, and may require more than one operation to correct.

VOICE ONE:

Now, the University of Southern California researchers say their work may make it possible for doctors to heal cleft palate before birth. The researchers carried out experiments with fetal mice. They say levels of a protein called Shh need to remain largely unchanged in a developing fetus for the palate to develop correctly. Too much or too little of the protein can cause a cleft condition.

Two genes are responsible for Shh levels. The Msx1 gene increases production of the protein. A gene called DIx5 decreases it. Both genes are necessary for the healthy development of the palate, teeth, skull and other facial structures.

VOICE TWO:

The researchers produced mice with a defect in the Msx1 gene. The resulting lack of Shh proteins caused palates to begin forming in the fetal mice. The researchers then took steps to suppress the DIx5 gene. This caused an increase in the protein, and the palate began to regrow.

When the animals were born, their palates were undamaged. The palates were structurally a little different than those of other mice, but they worked normally. And, the newborn mice were able to feed without problems.

The U.S.C. team says it hopes future research will help prevent or treat cleft conditions in people.

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VOICE ONE:

Scientists continue to seek better weapons against malaria. Each year the number of cases is in the hundreds of millions worldwide. Around a million people die, most of them in Africa. Economic losses from the disease represent an estimated one percent of the African economy each year.

George Dimopoulos is an associate professor at the Johns Hopkins Malaria Research Institute in Baltimore, Maryland.

GEORGE DIMOPOULOS: "Forty-two percent of the earth's population lives in areas where malaria transmitting mosquitoes exist. All of these people are in risk of being infected with malaria. The sad thing is that the majority of people that are killed by malaria are children because there immune system is not strong enough to ward off this infection."

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Malaria is spread by some mosquitoes

Malaria is caused by a parasite called Plasmodium. The parasite enters people through the bite of infected mosquitoes. Malaria can be treated, but in many areas the organisms have become resistant to different drugs.

George Dimopoulos and his team are studying ways to make mosquitoes resist infection by the parasite. There are hundreds of kinds of mosquitoes in the world. Most do not spread malaria. Some of the insects have disease-fighting systems that kill Plasmodium.

GEORGE DIMOPOULOS: "We are particularly interested in these type of immune reactions that are responsible for killing the malaria parasite. Because we think once we understand how they work, we could be able to manipulate the mosquito genetically and convert mosquitoes that can transmit malaria into mosquitoes that cannot transmit malaria."

VOICE ONE:

The researchers have developed a way to make genetic changes in the three mosquito species known to spread malaria. The changes cause their systems to attack the parasite, blocking its development. Other researchers are working on ways to spread these genetically-engineered insects among mosquito populations.

Professor Dimopoulos says there is still a long way to go, but current malaria research is highly promising.

A new vaccine is in final testing. The vaccine has already proven effective at preventing the disease in half of those vaccinated -- which is more than ever before.

VOICE TWO:

Work is also being done at the Malaria Institute at Macha in Zambia. Researchers there are developing an easier way to identify malaria. The test uses saliva instead of blood to confirm the infection.

Current efforts in malaria control are mainly based on the use of insecticide sprays and treated bed nets. But George Dimopoulos says malaria needs to be attacked with drugs, with vaccines, with bed nets -- with whatever researchers can find.

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VOICE ONE:

This SCIENCE IN THE NEWS was written by June Simms and Brianna Blake, who was also our producer. I'm Bob Doughty.

VOICE TWO:

And, I'm Shirley Griffith. Listen again next week for more news about science in Special English on the Voice of America.