| |
|
|||
| 出处: 更新:2006-03-08 | 作者: | 责编:keensoldier | |
| 在线收听: Tests Often Miss a Hidden Heart-Attack Risk in Women
For example, they say a condition called coronary microvascular syndrome appears to be more common in women than men. When a heart attack is suspected, doctors look for a major blockage in the arteries that supply oxygen to the heart. With coronary microvascular syndrome, fatty material spreads evenly in very small arteries of the heart. This buildup of plaque along the artery wall narrows the flow of oxygen. The pain can be similar to that of blocked arteries. But doctors often miss this condition because it does not show up in the usual tests for blockages. Women are often sent home, thinking they are OK. Yet many are at high risk for a heart attack. In the United States, researchers say as many as three million women could have coronary microvascular syndrome. The Journal of the American College of Cardiology recently published findings from a government study. The study is called the Women’s Ischemia Syndrome Evaluation, or WISE. Ischemic heart disease involves restricted blood flow. The study began in nineteen ninety-six and involves more than nine hundred women who suffer chest pain. Researchers found large blockages in major arteries in about one-third of the women. The other women looked clear on an angiogram test for blockages. But the researchers say half of them had enough buildup in small arteries to cause a heart attack within five years. Scientists have been trying to better understand why heart disease is often discovered later, and treated less aggressively, in women. Women are also less likely to react as well as men to treatment. Experts note that women are generally older than men when they have a heart attack. The National Heart, Lung and Blood Institute says women are also less likely to believe they are having a heart attack. So they more likely to delay emergency treatment. In men and women both, the most common warning sign is chest pain. But women are more likely to experience other common signs like shortness of breath, a sick stomach and pain in the back or jaw. A cold sweat and feeling lightheaded can also mean a heart attack. This VOA Special English Health Report was written by Cynthia Kirk, and can be found at voaspecialenglish.com. I’m Steve Ember. Wet and Dry, Fire and Ice: Visiting Seven of America’s Natural Wonders
VOICE ONE: I’m Steve Ember. VOICE TWO: And I’m Barbara Klein with Explorations in VOA Special English. We received a special request in a letter from a listener in Nagano, Japan. Atsumi Shimoda asked for a report about what the Special English writers thought were the seven natural wonders of the United States. (MUSIC) VOICE ONE: So now we will visit these natural wonders. Some are huge. Some are powerful. And some are even a little frightening! But, we will keep a safe distance. The first stop is a natural wonder that the United States shares with Canada. (SOUND) Canada owns the larger Horseshoe Falls. It is about eight hundred meters wide and almost fifty meters high. It is shaped like the letter U, or a horse’s shoe. VOICE TWO: Niagara Falls formed about twelve thousand years ago when huge melting sheets of ice formed the Great Lakes. The land was uneven with several drops in level, some very sharp. Water from Lake Erie began to flow north to Lake Ontario as a result of the loss of the ice barrier. In modern times, several people have gone over Niagara Falls, most of them on purpose. Most also survived. But, we think the beauty and power of Niagara Falls is best experienced from near the water, not in it. Now we travel southeast to the state of Florida. We will visit the area once called “the liquid heart” of that state -- the Everglades. (MUSIC) VOICE ONE: This is the Everglades -- a low, watery, partly coastal area that covers ten thousand square kilometers. The area is filled with sawgrass. This plant grows in sharp, thin pieces that are three to ten meters tall. The Everglades is sometimes called “river of grass.” The area also contains forests of palm, cypress, mangrove and pine. And beautiful plants and sweet-smelling flowers grow in the Everglades. These include several kinds of the highly prized and rare flower, the orchid.Animal species are plentiful. Many colorful birds and butterflies live here. So do snakes, foxes, frogs and even big cats, called Florida panthers. But, the Everglades alligators and crocodiles are probably the animals most identified with the Everglades. No other place in the world is home to both. (MUSIC) VOICE TWO: Suddenly, the land becomes torn and rocky, dry and dusty -- no longer green and gold. It is now a light red-brown color. All around are broken disordered forms. There are hills and valleys of all sizes and strange shapes. VOICE ONE: These are the Badlands. Hundreds of thousands of years ago the area was grassland. But, then, forces of nature destroyed the grass. Water and ice cut into the surface of the earth. They beat at the rocks, wearing them away. The result is one of the world’s strangest sights. All together, the Badlands cover more than fifteen thousand square kilometers. About ten percent is national parkland. The area is a study in extremes. Temperatures in the summer have been as high as forty-six degrees Celsius. In the winter they have dropped to as low as forty-one degrees below zero. Life in the Badlands is difficult. But animals do survive. The most well known is the prairie dog. This small mammal lives in a series of underground passages. (MUSIC) VOICE TWO: The Grand Canyon is a series of deep long cuts in rock. There are many passages and large raised areas. There are forests on the top level and desert areas down below. They provide support for several different ecosystems. The Colorado River flows through the Grand Canyon.The Canyon offers a lot of information about the physical history of Earth. There is a huge amount of fossil evidence. And its walls provide a record of three of the four major periods of the Earth’s geologic time. (MUSIC) VOICE ONE: An area called Badwater sits about eighty-six meters below sea level. There is not really any water there. The area gets fewer than five centimeters of rain a year. During the summer the temperature in Death Valley can reach fifty-seven degrees Celsius. But, it can be dangerously cold in the winter there, too. And storms in the mountains can produce sudden flooding on the valley floor. In other words, Death Valley is an unforgiving place. The heat has killed people in the past. And it will continue to kill those who are not careful in dealing with the area’s extreme climate. Death Valley holds much evidence of nature’s past violence. For example, there is Ubehebe [u-be-he-be] Crater. This hole is about one kilometer across and more than two hundred thirty meters deep. It is the remains of a major volcanic explosion about two thousand years ago. (MUSIC) VOICE TWO: About one hundred thousand of these rivers of ice flow down mountains. Some start from thousands of meters up a mountain. They can flow to areas just a few hundred meters above sea level. The largest Alaskan glacier is called Malaspina. It is more than two thousand two hundred square kilometers. VOICE ONE: Most glaciers move very slowly. But sometimes one will suddenly speed ahead for a year or two. These are called surge-glaciers. The most recent surges were in two thousand. The Tokositna glacier and Yanert Glaciers now have deep, narrow cuts on their formerly smooth surfaces. Yanert Glacier dropped ninety-one meters as a result of the surge. It is always very cold on the glaciers. Next we go to a hot spot. Sometimes very hot. (MUSIC) VOICE TWO: Kilauea has been releasing burning hot liquid rock called lava continuously since nineteen eighty-three. The lava flows down the mountain to the Pacific Ocean. Its fierce heat produces a big cloud of steam when it hits the cold water. Kilauean lava continues to add land to the island. Sometimes visitors are able to walk out near the edge of this new black volcanic rock. VOICE ONE: These seven natural American wonders, from waterfalls to volcanoes, are not the only ones in the United States. What about the Great Salt Lake, the Old Faithful Geyser, the Mammoth Caves and the giant redwood forests? We will have to report about them and other natural wonders another time. (MUSIC) VOICE TWO: This program was written and produced by Caty Weaver. I’m Barbara Klein. VOICE ONE: And I’m Steve Ember. Join us again next week for another EXPLORATIONS in VOA Special English.
|
| 上一篇: 在线收听VOA特别英语(03-01) |
下一篇: 在线收听VOA特别英语(03-20) |
|
|
| 本文评论 |
| 发表评论 | 打印本页 | 加入收藏 | 返回顶部 |
|
|
|
|
|
| 文章搜索 |
| 每日更新 |
|
| 焦点资源 |
|
