Scientists Say Arctic Ice Continues to Shrink
Also: Young men in Kenya change from killing lions to helping keep them alive. Transcript of radio broadcast:
04 May 2009
VOICE ONE:
This is SCIENCE IN THE NEWS in VOA Special English. I’m Doug Johnson.
VOICE TWO:
And I’m Faith Lapidus. This week, we will tell about ice loss in the Arctic Sea. We also will tell about a campaign to improve treatment of snakebites. And we report on an effort to save wild lions in Africa.
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VOICE ONE:
American scientists say ice covering the Arctic Sea continued to shrink last winter. The scientists say they recently found that older, thicker sea ice was increasingly replaced with new ice. The new ice is thinner and melts faster than the older ice.
The scientists work for the American space agency and the National Snow and Ice Data Center in Boulder, Colorado. The two government agencies have been studying Arctic Sea ice from space since nineteen seventy-nine. One of the scientists says the past six years have shown the lowest Arctic sea ice cover ever measured.
VOICE TWO:
The study found an average ice cover of about fifteen million square kilometers in March. That is seven hundred thirty kilometers above the record low set three years ago. But it represents a loss of about five hundred ninety thousand kilometers from the yearly average between nineteen seventy-nine and two thousand.
Scientists say ninety percent of all Arctic sea ice is only one or two years old. This is up from forty to sixty percent in the nineteen nineties. The newer ice, experts say, is less resistant to melting during the summer months.
VOICE ONE:
The amount of ice cover and its thickness are two measures of the health of the Arctic Sea. Arctic sea ice is important because it throws sunlight back into space, keeping the sea cold. The ice also cools the air. But when the ice melts, the sun warms ocean waters.
Walter Meier is a scientist with the National Snow and Ice Data Center. He says a warmer Arctic and thinner sea ice changes the balance between the normally cold Arctic and warmer areas. He says changes to the ice cover also affect Arctic wildlife and people who depend on the local environment. The melting has already threatened native animals like the polar bear. Arctic melting could also affect Earth’s climate.
Professor Meier also says the possibility of ships being able to move through newly unfrozen parts of the Arctic could lead to losses of natural resources. He says the competition this could create may also threaten international security.
VOICE TWO:
The study follows a separate report by the United States Oceanic and Atmospheric Administration and the Joint Institute for the Study of Atmosphere and Ocean. That study used computers and current ice-level information to predict future ice levels. The findings predicted that most of the Arctic’s summer ice could disappear in thirty years.
Parts of Antarctica are also believed to be melting because of climate change. Satellite images show an ice bridge that held a huge Antarctic ice shelf in place recently broke apart.
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VOICE ONE:
More than four million people around the world are bitten by snakes each year. At least one hundred twenty-five thousand of these people die. Almost three million others are seriously injured. Doctors and researchers say the world does not provide enough good treatment for poisonous snakebites. To help improve the situation, experts have formed a project called the Global Snakebite Initiative.
Poisonous snakebites are common in rural areas of many developing countries with warm climates. Many victims are agricultural workers and children in Asia and southern Africa. Shortages of antivenom medicines, the treatment for snakebite, are common there. Existing supplies may not be high quality or developed correctly for local needs.
VOICE TWO:
Ken Winkel directs the University of Melbourne’s Australian Venom Research Unit. He and university scientist David Williams are among the organizers of the Global Snakebite Initiative. Other project leaders are from Britain, Brazil, Sri Lanka, Costa Rica and Singapore.
The International Society of Toxinology supported the Initiative at the recent World Congress of Plant, Animal and Microbial Toxins in Recife, Brazil.
Doctor Winkel says antivenom treatment is too costly for many poor people who need it most. The drugs are developed from the venom of poisonous snakes.
VOICE ONE:
The Global Snakebite Initiative is working to increase the availability of good quality antivenom treatments and improve medical training for patient care. Another goal is to help manufacturers of antivenom medicines improve their products.
The project also wants communities to learn about snakebites and first aid. It wants more research and reporting systems. And it aims to help national health officials choose antivenoms for their countries’ special needs.
The antivenom that cures the bite of one kind of snake may not be effective for another kind of snake. And the medicines for a cobra bite in the Philippines may not work for someone bitten by a similar snake in West Africa.
Experts look forward to improvements in worldwide treatment for snakebite. But they say the best ways to reduce death and injury from snakebites are education and prevention.
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VOICE TWO:
A male lion stands in a tree in the Masai Mara game reserve in Kenya.
A male lion in the Masai Mara game reserve in Kenya
Up to two hundred thousand lions lived in Africa twenty years ago. Today, fewer than thirty thousand lions live there, many in protected areas. But environmental activists are working to save the animals. And, the activists have some unexpected helpers.
Members of the Maasai people have stopped killing lions and now are protecting them. Maasai herders care for cattle, sheep and goats on the Mbirikani Group Ranch. This community-owned ranch is in southeastern Kenya. It covers more than one hundred twenty one thousand hectares.
Maasai warriors in their late teenage years, twenties and early thirties are called murran. The murran normally gain fame and honor if they kill a lion. But some of them now defend the animals and work to keep them alive. The murran are called Lion Guardians. They are part of a scientific and environmental-protection group called Living with Lions.
VOICE ONE:
The Lion Guardians help herders find lost sheep, goats and cows. They observe the movement of lions and warn herders of their presence. Sometimes the guardians intervene and break up lion-hunters.
If a lion does kill a herd animal, the Maasai receive money from a program that repays herders for losses. The program has lessened the traditional conflict between herders and lions.
The murrans can follow a lion for hours without needing to drink water. They also learn radio work. That knowledge helps them find lions wearing radio collars. Scientists place the devices around the lions’ necks so they can follow their movements.
Some guardians also learn to read and write so they can keep records of their work. Others keep records using pictures.
VOICE TWO:
The Lion Guardians have been facing an especially difficult situation in recent times. Herders in Kenya are suspected of killing lions with a pesticide product, Furadan. They reportedly pour the product on dead animals that lions eat. Furadan makes the lions unable to move, then causes a painful death.
Laurence Frank is a lion expert with the University of California at Berkeley. He says up to seventy-five wild Kenyan lions may have died this way during the past five years. Professor Frank heads the Living with Lions group.
In reaction to protests, the manufacturer of Furadan stopped all sales of it in Kenya. But environmental activists worry that the pesticide is already in stores and people’s homes. Farmers use it to protect crops from insects, worms and mites.
VOICE ONE:
African lions are also threatened by human expansion into areas that once were wild lion country. Other enemies are hunters who kill lions for their body parts. The parts are then used in traditional medicines and souvenirs.
And, diseases sometimes kill large numbers of lions. Infectious animal tuberculosis, for example, has established itself as a threat to lions in southern Africa. Researchers also blame long periods of dry weather and heavy rain. Some scientists say climate change makes this worse.
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VOICE TWO:
This SCIENCE IN THE NEWS was written by Jerilyn Watson and Brianna Blake, who was also our producer. I’m Faith Lapidus.
VOICE ONE:
And I’m Doug Johnson. Transcripts, MP3s and podcasts of our programs are at voaspecialenglish.com. Join us again next week for more news about science in Special English on the Voice of America.
Osteoporosis Increases Danger of Broken Bones
The disease gives no signs of harm — at first. Transcript of radio broadcast:
27 April 2009
VOICE ONE:
This is SCIENCE IN THE NEWS, in VOA Special English. I’m Barbara Klein.
VOICE TWO:
And I’m Bob Doughty. Today we tell about osteoporosis, a disease that can make bones weak so they break easily.
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VOICE ONE:
Osteoporosis is a silent disease until it develops. If you do not know you have it, it can hurt you.
A fifty-five year-old American woman named Jill went skiing several years ago. Although she was a good skier, she fell on a difficult hill. She attempted to get up, but could not move one leg. She was taken to a hospital, where doctors found she had broken a bone in her upper leg. And there was another discovery in the hospital. She had osteoporosis.
Today, Jill still goes skiing. But now she takes medicine to protect against osteoporosis.
VOICE TWO:
Like Jill, many people do not know they have osteoporosis unless they break a bone. Or, they may find that they are getting shorter.
Osteoporosis can make it hard for a person to stand up straight if the disease is untreated for a long time. When it has progressed very far, walking can be difficult. Severe osteoporosis in older adults can take away their independence.
The National Osteoporosis Foundation works to inform Americans about bone health. The group says breaks caused by weakened bones can lead to pain, disability and even death
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VOICE ONE:
The word osteoporosis means porous bones, or bones that are not solid enough. The disease harms bones by removing calcium and other important minerals from tissue. Bones are living tissue. Tissues continually break down and then they replace themselves. But as people get older, more bone breaks down than gets replaced. The result is that small spaces inside the bone get larger. And the shell of the bones gets thinner.
The National Osteoporosis Foundation, or NOF, says eight of every ten osteoporosis patients are women. It says the condition is most common in Caucasian women over age fifty. Last year, the group suggested that doctors expand their list of persons to watch for osteoporosis. The additions included Latina, African American, Asian and other women. The NOF also called attention to the fact that men can also suffer from osteoporosis.
VOICE TWO:
Before people develop osteoporosis, they have a condition called osteopenia. Treatment can prevent this condition from becoming osteoporosis. Doctors agree that the best way to deal with osteopenia or osteoporosis is to find and treat it before the disease progresses. Bone damage need not be permanent. Drugs can help replace lost bone.
Identification of osteoporosis and osteopenia is made by measuring the mineral density of a person’s bones. In this case, density means the strength of the bones.
VOICE ONE:
The American Academy of Orthopaedic Surgeons says there are a number of ways bone mineral density can be measured. The group suggests bone mineral density examinations for women sixty years and older. Doctors use the tests to examine the hip and spine, or backbone.
The NOF says a test called Dual-energy X-ray absorptiometry, or DXA, is the best test for osteoporosis. DXA uses radiation from x-rays. The patient does not get much radiation from the process, which lasts only a few minutes.
VOICE TWO:
Another way to measure bone-density is called peripheral bone mineral density testing. It is often used in the United States to show people if they are in danger of osteoporosis. A moveable machine does the test.
Medical testing companies sometimes perform this examination at an office or other place of business. The test costs less than the DXA. But peripheral testing measures only one part of the body. Usually that place is the wrist, the heel, or the bones between finger joints.
If the testing device is in good condition, it probably will give satisfactory results. But what if the patient has normal bones in the tested areas, but not in others? A person could appear normal on the test. But she still might have osteoporosis in her backbone or hips.
VOICE ONE:
Differences in bone mineral density among body parts are most often found in women who recently ended their childbearing years. The density may be normal at one place but low at another. Bone mineral density in the spine decreases first. A woman’s bone mineral density becomes about the same in all parts of her body after she is seventy years old.
The lower-cost test may not give complete answers. But it can warn that osteoporosis threatens or has started.
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VOICE TWO:
The National Osteoporosis Foundation has advised several steps toward the goal of healthy bones. Its experts say get enough calcium and vitamin D. The experts say do not smoke or drink too much alcohol. Talk to your healthcare provider about bone health and a possible bone mineral density test.
The NOF’s guide for healthcare providers says people over fifty should get one thousand two hundred milligrams of calcium every day. The guide also says this age group should get eight hundred to one thousand International Units of Vitamin D. It says Vitamin D-Two and Vitamin D-Three are both good for bones.
VOICE ONE:
Milk and milk products contain calcium. So do fish with soft bones, like salmon, and dark green leafy vegetables. Some orange juice, bread and cereals may have calcium added.
Some people also take pills containing calcium. But be careful about how much calcium you take. You should not have more than two thousand five hundred milligrams a day. That total includes calcium from food and all other sources. Too much calcium can cause problems like kidney stones.
VOICE TWO:
Vitamin D absorbs, or takes up, calcium. Fish, cereal and milk are good sources of Vitamin D. If you spend at least fifteen minutes a day in the sun without a product to block the sun’s radiation, you probably get enough Vitamin D.
Several kinds of drugs treat osteoporosis. America’s Mayo Clinic medical centers say bisphosphonates are the most popular. Fosamax, Actonel and Boniva are products of this family of drugs. The Mayo Clinic advises that these drugs are very effective and appear safe for most people if taken as directed. Fosamax has been sold for at least ten years. Other drugs proven effective for osteoporosis are hormones and parathyroid hormone.
VOICE ONE:
Doctors who treat osteoporosis patients say physical exercise can help the bones. For active people, lifting weights or playing tennis, slow running and dancing can be helpful.
Some older adults worry about exercising. They believe they could hurt themselves. The Mayo Clinic says that could be true if they have not exercised in the past. It says people who have not been active in the past need a doctor’s advice before starting.
VOICE TWO:
Some people who are afraid of exercise worry about its effects on their joints, especially the knees. They are afraid exercise might cause osteoarthritis, a condition in which connective tissue around the bones wears down. A study in The Netherlands found that could be true. Results of the study were reported recently in the publication “Arthritis Care and Research.”
Researchers studied one thousand six hundred seventy eight people over a period of twelve years. The subjects were between fifty-five and eighty-five years old. The results linked knee osteoarthritis to high mechanical strain — activities that are hard on joints.
VOICE ONE:
But another study found that regular exercise does not harm joints. Those findings were reported in “The Journal of Anatomy.” Scientists from Germany and the United States considered earlier research on the effect of exercise on joints. They did not find a link between regular exercise and knee osteoarthritis.
If you are still worried about exercise for osteoporosis, why not go for a walk? But you have to do it correctly. The Mayo Clinic says hold your head high. Straighten your back and neck as much as possible. Tighten the chest muscles. As you move along, let your shoulders and arms move freely and naturally.
Walking places the full weight of your body on your bones. It also has other good effects. It raises the levels of chemicals in the brain known as endorphins. They reduce pain and make you feel happier.
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VOICE TWO:
This SCIENCE IN THE NEWS program was written by Jerilyn Watson. Our producer was Brianna Blake. I’m Bob Doughty.
VOICE ONE:
And I’m Barbara Klein. Join us again next week for more news about science in Special English on the Voice of America.
Vitamins Are Important to Good Health
Some people fear they do not get enough vitamins from the foods they eat. So they take products with large amounts of vitamins. Transcript of radio broadcast:
20 April 2009
VOICE ONE:
This is SCIENCE IN THE NEWS, in VOA Special English. I’m Bob Doughty.
VOICE TWO:
And I’m Faith Lapidus. This week, we tell about vitamins.
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VOICE ONE:
Vitamins
Many jobs must be done with two people. One person takes the lead. The other helps. It is this cooperation that brings success.
So it is with the human body. Much of our good health depends on the cooperation between substances. When they work together, chemical reactions take place smoothly. Body systems are kept in balance.
Some of the most important helpers in the job of good health are the substances we call vitamins.
VOICE TWO:
The word “vitamin” dates back to Polish scientist Casimir Funk in nineteen-twelve. He was studying a substance in the hull that covers rice. This substance was believed to cure a disorder called beriberi.
Funk believed the substance belonged to a group of chemicals known as amines. He added the Latin word “vita,” meaning life. So he called the substance a “vitamine” — an amine necessary for life.
VOICE ONE:
Funk was not able to separate the anti-berberi substance from the rice hulls; it was later shown to be thiamine. Other studies found that not all vitamines were amines. So the name was shortened to vitamin. But Funk was correct in recognizing their importance.
Scientists have discovered fourteen kinds of vitamins. They are known as vitamins A, the B group, C, D, E and K. Scientists say vitamins help to carry out chemical changes within cells. If we do not get enough of the vitamins we need in our food, we are at risk of developing a number of diseases.
VOICE TWO:
This brings us back to Casimir Funk. His studies of rice were part of a long search for foods that could cure disease.
One of the first people involved in that search was James Lind of Scotland. In the seventeen-forties, Lind was a doctor for the British Navy. He was investigating a problem that had existed in the Navy for many years.
The problem was the disease scurvy. So many sailors had scurvy that the Navy’s fighting strength was very low. The sailors were weak from bleeding inside their bodies. Even the smallest wound would not heal. Doctor Lind thought the sailors were getting sick because they failed to eat some kinds of foods when they were at sea for many months.
VOICE ONE:
Doctor Lind separated twelve sailors who had scurvy into two groups. He gave each group different foods to eat. One group got oranges and lemons. The other did not. The men who ate the fruit began to improve within seven days. The other men got weaker. Doctor Lind was correct. Eating citrus fruits prevents scurvy.
Other doctors looked for foods to cure the diseases rickets and pellagra. They did not yet understand that they were seeing the problem from the opposite direction. That is, it is better to eat vitamin-rich foods to prevent disease instead of eating them to cure a disease after it has developed.
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VOICE TWO:
Which foods should be eaten to keep us healthy? Let us look at some important vitamins for these answers.
Vitamin A helps prevent skin and other tissues from becoming dry. It is also needed to make a light-sensitive substance in the eyes. People who do not get enough vitamin A cannot see well in darkness. They may develop a condition that dries the eyes. This can result in infections and lead to blindness.
Vitamin A is found in fish liver oil. It also is in the yellow part of eggs. Sweet potatoes, carrots and other darkly colored fruits and vegetables contain substances that the body can change into vitamin A.
VOICE ONE:
Vitamin B-one is also called thiamine. Thiamine changes starchy foods into energy. It also helps the heart and nervous system work smoothly. Without it, we would be weak and would not grow. We also might develop beriberi.
Thiamine is found not just in whole grains like brown rice, but also in other foods. These include beans and peas, nuts, and meat and fish.
Another B-vitamin is niacin. It helps cells use food energy. It also prevents pellagra — a disease that causes weakness, reddish skin and stomach problems. Niacin is found in meat, fish and green vegetables.
VOICE TWO:
Vitamin B-twelve is needed so folic acid can do its work. Together, they help produce red blood cells. Vitamin B-twelve is found naturally in foods like eggs, meat, fish and milk products. Folic acid has been shown to prevent physical problems in babies when taken by their mothers during pregnancy.
Vitamin B-twelve is found in green leafy vegetables and other foods, like legumes and citrus fruits. In some countries, it is added to products like bread.
VOICE ONE:
In two thousand three, Japanese researchers identified a new member of the B-vitamin group. It is a substance known as pyrroloquinoline quinone or PQQ.
The researchers found that PQQ is important in the reproductive and defense systems of mice. They said the substance is similarly important for people. PQQ is found in fermented soybeans and also in parsley, green tea, green peppers and kiwi fruit.
VOICE TWO:
Vitamin C is needed for strong bones and teeth, and for healthy blood passages. It also helps wounds heal quickly. The body stores little vitamin C. So we must get it every day in foods such as citrus fruits, tomatoes and uncooked cabbage.
Vitamin D increases levels of the element calcium in the blood. Calcium is needed for nerve and muscle cells to work normally. It also is needed to build strong bones.
VOICE ONE:
Vitamin D prevents the children’s bone disease rickets. Ultraviolet light from the sun changes a substance in the skin into vitamin D. Fish liver oil also contains vitamin D. In some countries, milk producers add vitamin D to milk so children will get enough.
Vitamin K is needed for healthy blood. It thickens the blood around a cut to stop bleeding. Bacteria in the intestines normally produce vitamin K. It can also be found in pork products, liver and in vegetables like cabbage, kale and spinach.
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VOICE TWO:
Experts agree that everyone needs vitamins so that their bodies can operate normally. In general, a complete diet should provide all the vitamins a body needs in their natural form. In addition, many foods and food products now have extra vitamins and minerals added.
Some people fear they do not get enough vitamins from the foods they eat. So they take products with large amounts of vitamins. They think these products, called vitamin supplements, will improve their health and protect against disease. Many adults now take vitamin supplements every day.
VOICE ONE:
Vitamins
In two thousand six, medical experts gathered near Washington, D.C. to discuss studies about vitamin supplements. The experts found little evidence that most supplements do anything to protect or improve health. But they noted that some do help to prevent disease.
The experts said women who wish to become mothers should take folic acid to prevent problems in their babies. And, they said vitamin D supplements and calcium can protect the bones of older women.
VOICE TWO:
The medical experts agreed with doctors who say that people who know they lack a vitamin should take vitamin supplements. Some older adults, for example, may not have enough vitamin B-twelve. That is because, as people get older, the body loses its ability to take it from foods.
The experts also noted that taking too much of some vitamins can be harmful. They said people should be sure to discuss what vitamins they take with their doctors.
Several studies have not been able to show that taking vitamin supplements in addition to a balanced diet helps to prevent disease. One study found that older Americans do not get enough Vitamin C and required minerals. The study involved more than six thousand individuals. More than half of them took vitamin supplements.
VOICE ONE:
Vitamins are important to our health. A lack of required vitamins can lead to health problems.
Different vitamins are found in different foods — grains, vegetables and fruits, fish and meat, eggs and milk products. And even foods that contain the same vitamins may have them in different amounts. Experts say this is why it is important to eat a mixture of foods every day, to get enough of the vitamins our bodies need.
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VOICE TWO:
This SCIENCE IN THE NEWS program was written by Brianna Blake. I’m Faith Lapidus.
VOICE ONE:
And I’m Bob Doughty. Join us again next week for more news about science in Special English on the Voice of America.
