在线收听：

点击此处下载RM格式文件：

点击此处下载MP3格式文件：

At Thanksgiving, Turkeys Fly Out of Stores

Jerilyn Watson

November 21st, 2006

This is the VOA Special English Agriculture Report.

Flock of turkeys
American turkey producers will raise close to two hundred seventy million of the big birds this year. That is the estimate of the National Turkey Federation, an industry group. Tens of millions will be the traditional star of Thanksgiving holiday meals this Thursday and next month at Christmas.

Americans eat more turkey throughout the year, and more of it in general, than in the past. The federation says people ate an average of seven and one-half kilograms of turkey last year. But they ate three times as much pork, four times as much beef and five times as much chicken.

Lamb was a distant fifth in popularity behind turkey.

Turkeys produced more than three thousand million dollars in farm earnings last year. The five top producing states were Minnesota, North Carolina, Arkansas, Virginia and Missouri. The top five export markets for turkey meat from the United States were Mexico, China, Canada, Russia and Taiwan.

Turkey is sold many ways -- frozen, fresh, whole, cut into parts, ground up like hamburger, thinly sliced, roasted, fried, smoked. People eat it in sandwiches, in soups, in salads, in sausages and more. But at Thanksgiving people generally buy a whole bird -- in some cases, all prepared and ready to serve.

Modern turkeys are designed for industrial production and for a market where white meat is more popular than dark. The federation says a turkey usually has about seventy percent white meat.

Turkey hens lay eighty to one hundred eggs in a season. Producers use artificial insemination to fertilize the eggs. The turkeys grow quickly. In fourteen weeks, a hen weighs seven kilograms and is ready for market. Males take eighteen weeks to reach fourteen kilograms.

Most turkeys are raised what is known as the conventional way. But some higher-priced birds are raised outdoors, without antibiotic drugs and with a diet of feed grown without chemicals.

Some small farms raise what are called heritage turkeys. These native birds are smaller and take longer to grow. But they mate naturally and have more of a balance of dark and white meat. Heritage turkeys have a stronger taste that some people like.

But turkeys are sold by weight, and people often buy big ones for the holidays. So price may be the biggest consideration of all.

And that's the VOA Special English Agriculture Report, written by Jerilyn Watson. You can learn more about Thanksgiving at voaspecialenglish.com. I'm Shep O'Neal.

Autoimmune Diseases Threaten The Body's Natural Defense For Fighting Disease

Written by Brianna Blake

November 21st, 2006

VOICE ONE:

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

VOICE TWO:

And I'm Faith Lapidus. On our program this week, we talk about a sickness called lupus and other autoimmune diseases. Autoimmune diseases affect the immune system the body's natural defense for fighting disease.

(MUSIC)

VOICE ONE:

The immune system normally protects the body against foreign materials, such as viruses and bacteria. Autoimmune diseases result from a failure of the body's own defenses against disease. The immune system loses its ability to tell the difference between foreign materials and its own cells. So, the body starts attacking its own organs and tissues.

VOICE TWO:

The hands of of a lupus patient
There are three kinds of lupus. Discoid lupus affects only the skin and can be identified by red marks on the face or neck. These marks on the skin can also be a sign of another form of lupus called systemic lupus. Systemic lupus can affect almost any organ or organ system in the body. When people talk about lupus, they usually mean the systemic form of the disease.

Some kinds of medicines can cause what is called drug-induced lupus. This form of lupus usually goes away when the patient stops using the medicines.

VOICE ONE:

High body temperature and pain in the elbows or knees are common signs of lupus. Other signs are red marks on the skin, feelings of extreme tiredness and lack of iron in the body.

At different times, the effects of lupus can be either mild or serious. The signs of the disease can come and go. This makes identifying the disease difficult. There is no one laboratory test to tell is someone has lupus. Many people with lupus also suffer from depression.

Lupus can also lead to other health problems. Women with lupus are at greater risk of developing heart disease. And between thirty and fifty percent of lupus patients will develop lupus-related kidney disease, known as lupus nephritis.

(MUSIC)

VOICE TWO:

Experts are not sure what causes lupus. Genetics or environmental influences seem to be involved. Lupus has been known to attack members of the same family. Yet, the genes responsible have yet to be identified. Also, many women with lupus give birth to healthy babies.

Many scientists believe infections may cause lupus. So can extreme bodily or mental tension, commonly known as stress. Two other suspected causes are antibiotic drugs and hormones produced by the body.

In fact, hormones might explain why lupus affects women far more often then men. The Lupus Foundation of America says ninety percent of the people with lupus are women. Persons of African American, American Indian or Asian ancestry become infected more often than white women.

Scientists do not know why women are more at risk than men. They think it might have to do with female hormones, like estrogen. Another idea is that is could involve the foreign cells left in a woman's body after a pregnancy.

VOICE ONE:

There is currently no cure for lupus. Yet doctors have developed ways of treating the disease. Treatments are based on the condition and needs of each patient. No two individuals have the exact same problems. A treatment could include a combination of stress-reduction methods and drugs such as painkillers and steroids. Anti-malaria drugs also have been effective. Recent research also suggests that supervised exercise training can improve the quality of life for lupus patients.

It has been forty years since the United States Food and Drug Administration approved a drug especially for treating lupus. Several companies are working to make drugs that can help lupus patients. Organizations like the Lupus Foundation of America are working to increase public understanding of the disease. Early recognition of lupus and treatment can often prevent serious heath problems.

Lupus can be life threatening if left untreated. Yet, many patients can lead a normal and healthy life if they follow their doctor's advice. Patients must take their medicines and keep looking for side effects or new signs of the disease.

(MUSIC)

VOICE TWO:

Lupus is not the only autoimmune disease. Doctors and scientists have identified at least eighty other such diseases in which the body attacks its own organs and cells. Some of the diseases attack just one area of the body, like the skin, eyes or muscles. Others affect an organ system or even the whole body.

Some of the diseases are well known, such as rheumatoid arthritis, multiple sclerosis and type-one diabetes. Others are less well known and more difficult to identify.

For example, celiac disease is difficult to identify because the signs of the disease are so common. Patients may have low iron levels and experience stomach pain. The uncontrolled release of bodily wastes is also a problem.

Doctors might treat those signs and not know they are caused by celiac disease. Some people develop celiac disease after eating gluten, a protein found in all wheat products. It is not always clear that eating something as harmless as wheat can be bad for a person's health. For some patients, it can be years before the problem is correctly identified.

VOICE ONE:

The United States National Institutes of Health says autoimmune diseases affect an estimated five to eight percent of the country's population. That represents between fourteen million and twenty-two million Americans.

The physical, emotional and financial cost of autoimmune diseases is huge. Most of those affected are women. While people of all ages are affected, women who are old enough to have children are especially at risk.

Some autoimmune diseases like lupus and scleroderma are more common in African Americans. Diseases such as multiple sclerosis and type-one diabetes are more common among whites. Doctors do not yet know why this is true.

(MUSIC)

VOICE TWO:

New drugs are being tested to help treat autoimmune diseases. Some drugs can be a problem because they suppress the immune system. This means the body is less able to defend itself against infections. As a result, the side effects of the drugs can be as dangerous as the disease itself.

Newer drugs attempt to suppress only one small part of the immune system, not all of it. For example, drugs like Enbrel and Remicade block tumor necrosis factor. This is a protein that causes inflammation, a physical reaction to infection, injury or other causes. These drugs have been useful in treating autoimmune diseases like rheumatoid arthritis, psoriasis, and Crohn’s disease. However, the drugs are very costly. The drugs have also been found to increase the risk of cancer.

VOICE ONE:

Scientists continue searching for other methods of treatment. For example, some scientists hope to use stem cells to replace tissues damaged by disease. Stem cells have the ability to grow other cells, such as heart, nerve or brain cells.

Medical experts also are working together to improve the way autoimmune diseases are identified and treated. A few years ago, the Johns Hopkins Autoimmune Disease Research Center was formed in the American state of Maryland. The aim of the center is to bring together experts to improve the study of autoimmune diseases.

Private groups like the center show how important it is for scientists to share information about such diseases. Because each disease often affects different organs, many experts might be needed to treat the disorder. Experts need to know about the most recent medical research and technology. By sharing information about their patients, doctors also can learn from other cases.

VOICE TWO:

Government agencies also are working with to increase knowledge about autoimmune diseases. In the United States, the National Institutes of Health created an autoimmune disease research plan three years ago. The plan urges agencies from different areas to work together.

Both private and government organizations are working to increase public understanding of such diseases. This can help individuals better understand what to do should they develop a health problem. At the same time, medical researchers continue working to help patients have a better quality of life.

(MUSIC)

VOICE ONE:

This SCIENCE IN THE NEWS program written and produced by Brianna Blake. I'm Bob Doughty.

VOICE TWO:

And I'm Faith Lapidus. Join us again next week for more news about science in Special English on the Voice of America.

免责声明：

牛津英语网为广大网友提供VOA和BBC等国外电台资料，目的是提高英语水平，请提高对其内容的判断能力，我们已尽全力保证资料符合《全国人大常委会关于维护互联网安全的决定》的要求，但我们不对其内容负责！