This is SCIENCE IN THE NEWS, in VOA Special English. I'm Barbara Klein.
And I'm Steve Ember. On our program this week, we will tell about a new study of the Arctic Ocean.
We will also tell about a big cat that animal experts say is close to disappearing from the wild. And, we will talk about broken bones and how to treat them.
A new report says sea ice in the Arctic Ocean is melting more quickly than expected. American scientists say the ice is melting even faster than computer programs had estimated.
The scientists work for the National Center for Atmospheric Research and the National Snow and Ice Data Center at the University of Colorado. Results of their study were reported on Geophysical Research Letters, a website of the American Geophysical Union.
Scientists know that climate change has a major effect on the Arctic Ocean partly because sea ice is disappearing. They also know that areas of open seawater are expanding. Such areas are known to take in sunlight and increase temperatures. Scientists say this has helped to cause the loss of the Arctic's ice cover.
For the study, the American scientists compared eighteen computer programs with observations made by satellites and other instruments. The Intergovernmental Panel on Climate Change used the computer programs to prepare its two thousand seven estimates of climate change.
The computer programs gave estimates of the amount of ice in the Arctic Ocean in the month of September. September is when the Arctic has the least ice, after the warm, summer months. The computer estimates suggested an ice loss of two and a half percent for every ten-year period between nineteen fifty-three and two thousand six.
Newer studies of the Arctic have used information gathered by aircraft, satellites and ships. This information showed a loss of September ice cover of almost eight percent for every ten-year period between nineteen fifty-three and last year. This means the ice is disappearing about thirty years faster than the computer programs estimated.
The scientists say the programs might not have recognized the full effect of increased carbon dioxide and other gasses in Earth's atmosphere. They say their study suggests the gasses may have more of an effect than had been thought.
The study also measured the amount of ice lost in the Arctic in March. That is when the most Arctic sea ice is present. It showed the loss of ice in March is much less than the loss in September. Yet the computer estimates were wrong about how much. The new report says the March loss was almost two percent for every ten-year period between nineteen fifty-three and two thousand six. That is three times more than the loss suggested by the computer programs.
Study organizers say their findings confirm that the Arctic's ice cover is melting…and that this is happening faster than had been thought. They also say the study shows that summer sea ice in the Arctic may disappear much earlier than scientists had expected.
Animal experts say one of the world's most beautiful and rare kinds of big cat is close to disappearing from the wild. A study earlier this year found that only about thirty Amur leopards still live free. The cats are also called Far Eastern leopards.
Recently, their numbers decreased by one. An unidentified person shot a female Amur, then beat her to death. The animal's body was discovered last month in the Barsovy National Wildlife Refuge in eastern Russia.
An official of the World Wildlife Fund, Darron Collins, said this was the third such killing in the area in the past five years. Mister Collins said the death of even one adult female is a huge loss for the endangered cat. He noted that the killing reduces the possibility for cubs, or young.
It is not clear how many Amur leopards still live free. One population count was performed in February and March. Wildlife expert Dmitry Pikunov supervised this study. It found evidence of seven to nine males. The study identified three to seven females without cubs. Four leopards were identified as females with cubs. In all, five or six cubs were recorded. Six to eight animals could not be identified.
Researchers counted the Amur leopards by following the marks of their feet in the snow. The study involved thirty-five workers from three organizations, including the World Wildlife Fund. The Wildlife Conservation Society and the Pacific Institute of Geography of the Russian Academy of Science also took part.
Counts performed seven years ago and three years ago showed higher leopard totals. Officials say about one hundred of the animals are needed for survival.
Most of the land where the Amur leopard once lived was in China. New roads and climate change there threatened the animals. So did hunters who kill big cats for their body parts.
The surviving cats live in southwest Primorye. That area is near the border between Russia, China and North Korea.
The director of the Wildlife Conservation Society's Russia program organized an earlier count of Amurs. Dale Miquelle says the leopards should be counted in more modern ways. This would include use of radio, camera traps, and genetic testing.
Mister Pikunov says adult Amurs need about five hundred square kilometers with good forests to survive. He said they also need a large and continuing supply of animals like deer for food. He believes the answer to saving the Amur leopard is for governments to provide protected spaces for wildlife.
About three hundred Amur leopards live in zoos around the world.
Have you ever suffered a broken bone? The medical term for a broken bone is a fracture. But there are different kinds of fractures. A single fracture is when a bone is broken in just one place. You may have heard the term hairline fracture. This is a single fracture that is very small, like the width of a hair. A complete fracture is when the bone comes apart.
When a bone is broken in more than two places or gets crushed, the name for it is a comminuted fracture.
Still another kind is a bowing fracture. This happens with a bone that bends but does not break. It happens mostly in children.
Have you ever heard of a greenstick fracture? This is when a bone is bent and breaks along only one side, like a young stick of wood.
Another kind of break is an open or compound fracture. This is when the bone breaks the skin. This is very serious. There is both bone damage and a risk of infection in the open wound.
A lot of things happen as the body reacts to an injury like a broken bone. You might suddenly feel lightheaded. You might also feel sick to your stomach.
People who are seriously injured can go into shock. They might feel cold and unable to think clearly. Shock requires immediate medical attention.
But while broken bones can be painful, they are generally not life-threatening. Treatment depends on the kind of fracture. A doctor takes X-rays to see the break and sets a broken bone to make sure it is in the correct position.
Severe breaks may require an operation to hold the bone together with metal plates and screws.
Next, a person usually gets a cast put around the area of the break. Casts are usually worn for one to two months. The hard bandage holds the bone in place while it heals.
In some cases, instead of a cast, a splint made of plastic or metal will be placed over the area to restrict movement.
Doctors say broken bones should be treated quickly because they can restrict blood flow or cause nerve damage. Also, the break will start to repair itself, so you want to make sure the bone is lined up correctly.
Bones need calcium and vitamin D to grow and reach their full strength. Keeping your bones strong with exercise may also help prevent fractures.
Wearing safety protection like elbow pads and leg guards during activities is a good idea. If you think these might be restrictive, try a cast.
This SCIENCE IN THE NEWS was written by Nancy Steinbach, Caty Weaver and Jerilyn Watson. Brianna Blake was our producer. I'm Steve Ember.
And I'm Barbara Klein. You can read and listen to this program on our Web site, voaspecialenglish.com. Join us again next week at this time for more news about science in Special English on the Voice of America.