中國(guó)網(wǎng)站品牌欄目（頻道）
BOB DOUGHTY: This is SCIENCE IN THE NEWS, in VOA Special English. I’m Bob Doughty.
BARBARA KLEIN: And I’m Barbara Klein. Today, we will tell about two kinds of dinosaurs. Scientists say one of the creatures was brightly colored. Evidence shows the other was able to fly. We will also tell about a new drug treatment for rheumatoid arthritis. And we will tell about Washington’s famous cherry trees.
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Colorful Dinosaurs
BOB DOUGHTY: Many scientists have long thought that dinosaurs were brown or gray in color. But scientists examining the remains of a dinosaur say they have found evidence it had brightly-colored feathers. The findings were published in Science magazine.
American and Chinese researchers rebuilt the feathers of a flightless dinosaur called Anchiornis huxleyi. The small, two-legged creature lived about 150 million year ago. It would have weighed only about 110 grams.
BARBARA KLEIN: The researchers used an electron microscope and fossilized remains of 30 feathers that once covered the animal. The remains were discovered in Liaoning Province in China.
Researchers studied melanosomes in the feathers. These small, color-producing structures formed as the dinosaur was developing. The researchers compared the structures to the melanosomes that control the color of feathers on modern birds. They were then able to identify the colors of the dinosaur feathers.
The researchers say Anchiornis huxleyi appeared to have a dark gray or black body. They found that the top of the ancient creature was light brown in color. And, it had bright white wings. Each of the feathers had black on the end.
BOB DOUGHTY: Richard Prum is an evolutionary biologist at Yale University in Connecticut. He says the melanosomes were in very good condition. He says the dinosaur would be a beautiful creature if it were still alive. It would be similar to a bird called a Spangled Hamburg Chicken.
The discovery is useful to scientists in another way. It helps them better understand not only how dinosaurs looked but also how they behaved. Professor Prum says the colorful feathers were probably useful in getting the attention of a mate.
BARBARA KLEIN: Researchers believe they were about 90 percent successful in recreating the appearance of the dinosaur. They plan to use this method to identify the colors of other feathered dinosaurs. But the professor says it is difficult to find enough feathers from a single dinosaur to recreate all its colors.
Another team of researchers recently reported on the existence of two colors from different dinosaurs. They used the method developed by Professor Prum and his team.
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BOB DOUGHTY: Other scientists may have learned how a dinosaur with four wings was able to fly. American and Chinese scientists say the Microraptor gui probably was not equipped to fly from the ground. Instead, their work suggests that the cat-sized animal started flying from trees.
Researchers from the University of Kansas in the United States and China’s Northeastern University reported their findings earlier this year. A report about the study was published in the Proceedings of the National Academy of Sciences.
BARBARA KLEIN: The researchers used the fossils of a dinosaur that lived 125 million years ago. But its bones were in very good condition. The researchers made a hardened reproduction of the bones, without changing their positions. Then they added clay to create a model of the dinosaur. Next, they added real feathers cut to the correct size. The result was a re-creation of an ancient Microraptor.
The research team built a light-weight model of the animal. This model was designed to glide, or move, in an almost effortless flight. The feathers on the flying model were made of plastic. The scientists carried out a series of test-launches with the wings in different positions. They found that the best position for gliding had the back two wings in a position similar to that of a flying squirrel. The body of that animal looks almost flat as it glides from tree to tree.
BOB DOUGHTY: Other experts have said the Microraptor probably flew with its back wings a little under and in a direction like that of the front wings. But the published report says that would have forced it to fly in a difficult position.
The disagreement about the wings adds attention to a larger dispute. That argument is whether or not birds came from dinosaurs, as most experts agree. But others are like Larry Martin, a University of Kansas member of the research team. He says dinosaurs probably could not get off the ground to fly.
He and other experts believe that birds developed from creatures that were not dinosaurs. They believe ancestors of birds came from animals that lived in trees.
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New Treatment for Rheumatoid Arthritis
BARBARA KLEIN: People who suffer from rheumatoid arthritis experience such pain in their joints that even a simple daily activity can be difficult. A new drug is showing signs of halting the disorder and even un-doing its damaging effects.
One in every 100 people suffers from rheumatoid arthritis. Women are three times more likely to be affected than men. The exact cause of the disorder is unknown. But researchers are examining the body’s autoimmune system. In patients, the body’s natural defenses against disease seem to attack the person they are supposed to protect.
BOB DOUGHTY: Harris Perlman is an associate professor at the Feinberg School of Medicine at Northwestern University in Illinois.
HARRIS PERLMAN: “What happens is your immune response goes haywire and then your body starts to attack itself, so there’s a failure to shutdown. And how the cells shutdown is they actually die...”
BOB DOUGHTY: Harris Perlman says a protein in healthy immune cells causes them to die after they attack an invading virus or bacteria. But in rheumatoid arthritis, that protein is missing in some immune cells. Instead, the protein builds up in the joints and attack cartilage and bone.
The Northwestern University researcher took part in a study that found a way to turn off the immune system in mice with arthritis. He developed what he calls a suicide molecule that acts like the protein which tells cells to self-destruct.
BARBARA KLEIN: Harris Perlman says the suicide molecule halted and even reduced rheumatoid arthritis in 75 percent of mice in the study. He believes the treatment could also be effective in human beings. He says the next step is to develop microscopic nano-particles. He says these particles would offer a more exact method of transporting the short-lived drug, called B-H-three mimetic.
Current treatments for rheumatoid arthritis can reduce pain, but they do not work for everyone. They must be taken continuously and include side effects such as an increased risk of infection. Harris Perlman says the best part of the new treatment is that there were no harmful or major side effects. A report about the study appeared in the publication Arthritis and Rheumatism.
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Washington's Cherry Trees
BOB DOUGHTY: Finally, Saturday officially marks the return of spring to northern parts of the world. This winter has seemed more severe than normal in many areas, including Washington, D.C.
Snowfall records for Washington date back to 1884. By early February, this winter had already broken them with 142 centimeters of snow measured. But the storms that buried the American capital last month broke more than seasonal records. Heavy snow and high winds damaged some of the city's cherry trees. As the snow melted, workers were busy picking up broken branches, some as thick as 15 centimeters.
BARBARA KLEIN: Crowds expect a beautiful show as the cherry trees blossom along the edge of the Tidal Basin next to the Jefferson Memorial.
Peak blooming, when the trees are in full flower, may be delayed a little this spring. But the National Park Service says people can expect the usual show of pink and white flowers. The National Cherry Blossom Festival is set for March 27th through April 4th.
Twelve kinds of cherry trees grow around the Tidal Basin. The first trees were a gift from Japan in 1912. The Japanese later sent two more gifts of cherry trees.
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BOB DOUGHTY: This SCIENCE IN THE NEWS was written by Lawan Davis and Jerilyn Watson. Brianna Blake was our producer. I’m Bob Doughty.
BARBARA KLEIN: And I’m Barbara Klein. Join us again next week for more news about Science in Special English on the Voice of America.
rheumatoid arthritis: a disease that gets worse over a period of time and causes painful swelling and permanent damage in the joints of the body, especially the fingers, wrists, feet and ankles 類(lèi)風(fēng)濕性關(guān)節(jié)炎
melanosome: dark, mafic mineral bands formed in migmatite which is undergoing eutaxitic melting; probably to form granite 黑素
Microraptor gui: 顧氏小盜龍
autoimmune: an autoimmune disease or medical condition is one which is caused by substances that usually prevent illness 自體免疫的；自身免疫的
go haywire: to stop working correctly or become out of control 出故障；紊亂；失去控制
cartilage: the strong white flexible substance found between the joints in the body; a piece of this 軟骨組織；（一塊）軟骨
nano-particle: 納米粒子
Dinosaur Found in China 中國(guó)山東發(fā)現(xiàn)恐龍化石群
探索發(fā)現(xiàn)：史前“魔鬼蛙” 專(zhuān)吃小恐龍
Fossil from Liaoning flies into evolutionary history
（來(lái)源：VOA 編輯：陳丹妮）
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