VOA美国之声,练听力的好东西

1.Breast Cancer Study Could Change How Early Growths Are TreatedHave you ever felt lumps under the skin on the sides of your neck when you were sick? Those might be lymph nodes. They can get swollen and painful but their job is to fight infection. Lymph nodes are part of the body's defenses known as the lymphatic system.This complex system throughout the body makes and transports a protective fluid called lymph. Lymph is made of white blood cells, proteins and fats.In a patient with breast cancer, the cancer can spread to the large number of lymph nodes under the arm. Doctors have traditionally removed many of these lymph nodes in the hope of removing all the cancer.But the latest research finds nothing to gain by removing so many lymph nodes.Doctors have two choices when breast cancer starts to spread. They can do what is called a sentinel node biopsy. They remove the main growth and one or two lymph nodes nearest to it.Or they can take more aggressive action and remove a lot of lymph nodes. But that can lead to shoulder pain and permanent swelling of the arm.Dr. Armando Giuiliano at the John Wayne Cancer Institute in Santa Monica, California, was a leader of the study. He found that a sentinel node biopsy can be enough to eliminate all of the cancer. And the patient does not need to stay in a hospital to have it done.Dr. Giuliano and researchers at other American cancer centers studied almost nine hundred breast cancer patients. In each case, the cancer had spread to no more than two lymph nodes.Half of the women had the traditional surgery. Doctors removed an average of seventeen lymph nodes. The other half had the simpler operation with just one or two nodes removed. Then both groups received radiation treatment and chemotherapy drugs.Doctor Giuliano says rates of survival five years later showed that the less invasive operation was just as successful as the more aggressive action.ARMANDO GIULIANO: "The five-year survival was about ninety-two percent regardless of which operation. And, wonderfully, women who had the sentinel node biopsy alone did just as well as the women who had the more radical operation."The study appeared in the Journal of the American Medical Association. Some experts say the findings could change the way surgeons treat early breast cancers that have spread to the lymph nodes. But other doctors say they want more proof before they make a change.2.How Women Farmers Could Feed More in Developing WorldFood prices continue to rise, threatening to push more people into poverty and hunger. Experts have been urging increased efforts around the world to increase agricultural productivity. A new report by the United Nations Food and Agriculture Organization says one of the best ways would be to remove the barriers women farmers face that male farmers do not.Women farmers are often less productive than men, but there are good reasons for that, says Agnes Quisumbing. She is an economist with the International Food Policy Research Institute. She says women farmers have fewer resources than male farmers.The new FAO report says women make up forty-three percent of the world's farmers. But only about ten to twenty percent of them own the land they farm. Without owning land, it is harder for them to get credit to buy inputs such as better seeds and fertilizers. In many countries, women are half as likely as men to use fertilizers to increase the amount of crops.In addition, Ms. Quisumbing says many of the world's women are raising their children at the same time they are farming.The FAO report says helping women farmers could increase agricultural output in the developing world by as much as four percent. This in turn could reduce the number of undernourished people by as much as seventeen percent.AGNES QUISUMBING: "Just helping women farmers have the same access to inputs and control of resources that male farmers have would really do a lot in terms of improving agriculture productivity, reducing hunger and malnutrition."Ms. Quisumbing helped write the FAO report. She says the report does not try to gain sympathy. It makes the case for women farmers based on business reasons.AGNES QUISUMBING: "We hear a lot about how women are disadvantaged. And they tend to be very bleeding-heart arguments. But bleeding-heart arguments don't necessarily tell heads of state to move their money."She says governments should support programs that help women farmers. These include financial support to help them buy better seeds and fertilizers. But she says policies in many countries also need to change.She says many laws discriminate against women in the areas of property, labor force and marriage. Ms. Quisumbing says studies show that women are more likely than men to spend money on food, health and educating their children. And that means a better future for the next generation.3.Japan’s Early Warning System One of the Best in the WorldA powerful earthquake struck the northeastern coast of Japan at two forty-six p.m. local time on March eleventh. Japan's Meteorological Agency released its first tsunami warnings just three minutes later. The country has one of the best earthquake early warning systems in the world.There are more than four thousand Seismic Intensity Meters in place throughout Japan to measure earthquake activity. These meters provide information within two minutes of an earthquake happening. Information about the strength and the center of the earthquake can be learned within three minutes.There are also concrete sea walls around much of the Japanese coastline. But these measures proved no match for the powerful earthquake and tsunami.Costas Synolakis is a tsunami expert with the Department of Civil and Environmental Engineering at the University of Southern California in Los Angeles.COSTAS SYNOLAKIS: "Japan is one of those most well-prepared countries on earth in terms of tsunami warning. They had a warning. I think what went wrong is that they had not anticipated the size of this event."He says there are two reasons for this. Japan has not had any event anywhere near as big as this one in the last one hundred fifty years. And scientists had not expected such a large earthquake happening off the coast of Japan.The nine point zero magnitude earthquake was the fourth most powerful earthquake ever recorded worldwide. It was also the worst earthquake ever to hit Japan. The tsunami waves that followed were reported to have reached as high as thirteen meters in some areas.Costas Synolakis says Japan's concrete sea walls were not built to handle such high waves.COSTAS SYNOLAKIS: "The concrete seawalls in many places in Japan are about 10 meters, that's about 33 feet. In Sendai, they were about three meters, that's about 10 feet. So that shows you that at least in that area they were not expecting such a sizeable wave because they would have built a higher seawall."A tsunami wave can travel as fast as eight hundred kilometers per hour. To get to higher ground people would often have to travel for many kilometers. This can take more time than a fast traveling tsunami will permit. This is especially true in cases like Japan, where the center of the earthquake struck so close to the coastline. The tsunami waves followed almost immediately.Experts say early warning systems will continue to be limited by these facts until earthquakes and tsunamis can be predicted4.Words and Their Stories: Hold Your HorsesToday, we tell about "horse" expressions. In the past, many people depended on horses for transportation, farming and other kinds of work. A lot of people still like to ride horses. And, horse racing is also popular. So it is not surprising that Americans still use expressions about the animals.Long ago, people who were rich or important rode horses that were very tall. Today, if a girl acts like she is better than everyone else, you might say she should get off her high horse.Yesterday my children wanted me to take them to the playground. But I had to finish my work, so I told them to hold your horses. Wait until I finish what I am doing. My two boys like tocompete against each other and play in a violent way. I always tell them to stop horsing around or someone could get hurt.We live in a small town. It does not have any exciting activities to offer visitors. My children call it a one-horse town.Last night, I got a telephone call while I was watching my favorite television show. I decided not to answer it because wild horses could not drag me away from the television. There was nothing that could stop me from doing what I wanted to do.Sometimes you get information straight from the horse's mouth. It comes directly from the person who knows most about the subject and is the best source. Let us say your teacher tells you there is going to be a test tomorrow. You could say you got the information straight from the horse's mouth. However, you would not want to call your teacher a horse!You may have heard this expression: You can lead a horse to water, but you cannot make him drink. That means you can give someone advice but you cannot force him to do something he does not want to do.Sometimes a person fights a battle that has been decided or keeps arguing a question that has been settled. We say this is like beating a dead horse.In politics, a dark-horse candidate is someone who is not well known to the public. Sometimes, a dark horse unexpectedly wins an election.Another piece of advice is, do not change horses in midstream. You would not want to get off one horse and on to another in the middle of a river. Or make major changes in an activity that has already begun. In the past, this expression was used as an argument to re-elect a president, especially during a time when the country was at war.5.Japan's Nuclear Disaster Could Hurt Nuclear Energy PlansThe crisis at Japan's Fukushima Dai-Ichi nuclear energy center has raised questions about the future of the nuclear energy industry. Arjun Makhijani is president of the Institute for Energy and Environmental Research in the United States. He says the disaster in Japan is historic.ARJUN MAKHIJANI: "We are witnessing a completely unprecedented nuclear accident in that there have never been three reactors in the same place at the same time that have had a severe accident."This week, the chairman of America's nuclear agency said there is little chance that harmful radiation from Japan could reach the United States. Nuclear Regulatory Commission Chairman Gregory Jaczko also said America has a strong program in place to deal with earthquake threats.No new nuclear power centers have been built in the United States since nineteenseventy-nine. That was when America's worst nuclear accident happened at the Three Mile Island center in Pennsylvania. The accident began to turn public opinion against nuclear energy.To support more clean energy production, the Obama administration has been seeking billions of dollars in government loan guarantees to build new centers. Currently, about twenty percent of electricity in the United States comes from nuclear energy. But critics say nuclear power is too costly and dangerous to be worth further expansion.German Chancellor Angela Merkel said Germany would temporarily close seven nuclear power centers while energy policy is reconsidered. The European Union is planning to test all centers in its twenty-seven member nations.Developing nations are less willing to slow nuclear expansion. China said it will continue with plans to build about twenty-five new nuclear reactors. And India, under a cooperation agreement with the United States, plans to spend billions on new centers in the coming years.Japan has made nuclear energy a national priority since the nineteen seventies. Unlike many major economies, Japan imports eighty percent of its energy. The Nuclear Energy Institute says twenty-nine percent of Japan's electricity came from nuclear sources in two thousand nine.The government planned to increase that to forty percent by twenty seventeen.Nuclear reactors supply fourteen percent of global electricity. Nuclear energy is a clean resource, producing no carbon gases. But radioactive waste is a serious unresolved issue. So is the presence of nuclear power centers in earthquake areas like the one near Bushehr, Iran.6.Debating the Display of Ten Commandments in Public Schools and BuildingsIn Giles County, Virginia, the school board has removed displays of the Ten Commandments from its schools. The county thought that posting the Ten Commandments, along with the first part of the United States Constitution, might help increase moral values.There had been few complaints since the Commandments were posted almost twelve years ago. But recently, civil liberties groups had threatened to take the county to court if it did not remove them.The United States Supreme Court permits the Ten Commandments to be on public property so long as the goal of displaying them is not to gain support for religion. But in nineteen eighty, the Court ruled that the Ten Commandments cannot be shown in public schools because displaying them shows support of religion by the government.Jewish and Christian holy books say the Ten Commandments were laws given to the prophet Moses by God. Many Americans believe the country was founded on Judeo-Christian beliefs. Many of their beliefs are expressed in the Ten Commandments. They are a set of rules against murder, stealing, cheating, adultery and profanity.Douglas Laycock is a professor of constitutional law at the University of Virginia School of Law in Charlottesville. He says the Supreme Court has ruled that governments must be neutral about religious teachings.DOUGLAS LAYCOCK: "Putting up the Ten Commandments in a way that promotes the Jewish and Christian scriptures is a violation of the Constitution, and especially if they do it in a public school. Parents are entitled to send their children to school without having to proselytize somebody having somebody else's religion."Officials in Giles County say they may put the Ten Commandments back on the walls of the schools but will add other historical documents. Professor Laycock says it is possible that might satisfy a court.DOUGLAS LAYCOCK: "Whether or not they can keep the Ten Commandments on the wall...depends on how serious and plausible the things they put around it are. And, whether it looks like a genuine secular display that happens to include the Ten Commandments or whether it looks like just an excuse for putting this religious document on the wall."Since the Supreme Court ruling in nineteen eighty, more conservative justices have been appointed to the Court. Professor Laycock says some conservative activists believe this new, more conservative Court might be willing to once again permit the Ten Commandments to be displayed in public schools.7.Nuclear Crisis in Japan Raises Worries About Radiation RisksThe crisis at the damaged Fukushima Dai-Ichi Nuclear Power Station in northern Japan has raised worries about radiation risks. We spoke Tuesday with Jonathan Links, an expert in radiation health sciences. He is a professor at the Johns Hopkins Bloomberg School of Public Health in Maryland.Professor Links says workers within the nuclear plant are the only people at risk of extremely high doses of radiation.JONATHAN LINKS: "Of course, we don't know what doses they've received, but the only persons at risk of acute radiation effects are the workers."For other people, he says, there may be a long-term worry. People can get cancer from low doses of ionizing radiation, the kind released in a nuclear accident.Professor Links says scientists can use computers to quickly model where radioactive material has blown and settled. Then they measure how large an area is contaminated. He says if the situation is serious enough, officials could take steps like telling people not to eat locally grown food or drink the water.JONATHAN LINKS: "But that would only be the case if there was a significant release and, because of wind direction, the radioactive material was blown over the area, and then settled out of the air into and onto water, plants, fruits and vegetables."The reactors at Fukushima are on the Pacific coast. But Professor Links says people should not worry about any radioactive material leaking into the ocean.JONATHAN LINKS: "Even in a worst-case scenario accident, the sea provides a very high degree of dilution. So the concentration of radioactivity in the seawater would still be quite low."Japan is the only country to have had atomic bombs dropped on it. That memory from World War Two would create a stronger "psychological sensitivity" to radiation exposure, Professor Links says.Next month is the twenty-fifth anniversary of the explosion and fire that destroyed a reactor at Chernobyl in Ukraine. The nineteen eighty-six event was the world's worst accident in the nuclear power industry.A new United Nations report says more than six thousand cases of thyroid cancer have been found. These are in people who were children in affected areas of Belarus, Russia and Ukraine. The report says that by two thousand five the cancers had resulted in fifteen deaths.The cancers were largely caused by drinking contaminated milk. The milk came from cows that ate grass where radioactive material had fallen.8.Getting to the Bottom of a Fish Die-Off in Southern CaliforniaPeople in a community on the Pacific coast in Southern California awoke last week to a sea of dead fish. About eight hundred fifty sailboats and powerboats come and go from the marina at King Harbor in the city of Redondo Beach. But the sardines that swam into the marina never swam out. Estimates put the number of dead fish in the millions.Local resident John Archibald described the smell this way.JOHN ARCHIBALD: "Not bad. But I would not be ordering any pizzas around here lately."Reporter Pete Demetriou from KNX Newsradio in Los Angeles also spoke to another man who has lived in the area for twenty-six years.MAN: "The die-off was as bad as I've ever seen, but they cleaned up pretty quick, so there's not too much smell."REPORTER: "Well, you've got a few fish on the top here but they're concerned that a lot of it may still be down there on the bottom. What do you do, do you try to clean it up or let it just basically decompose?"MAN : "No, you just let it go. The crabs will get it."He remembered that about five years ago there was another serious kill-off of fish in King Harbor. It was caused by a harmful algae bloom, a so-called red tide of microscopic organisms that spread from time to time. But this time scientists found no toxic algae in King Harbor, so it was a mystery.On Friday a scientist at the University of Southern California released findings of continuing research in his laboratory. Professor David Caron said fish collected on March eighth, the day of the kill, tested "strongly positive" for domoic acid in their stomach contents. Domoic acid is a powerful neurotoxin produced by one kind of microalgae.Fish such as sardines and anchovy can get poisoned when they eat plankton that have eaten the algae.Researchers from USC confirmed that plankton collected about twenty kilometers southwest of Redondo Beach the next day had very high levels of domoic acid. This would support a theory that the fish became poisoned in coastal waters before entering the harbor.High levels of domoic acid in the sardines may have worsened the effects of oxygen loss in the water as the fish crowded into a limited space. Or the domoic acid may help explain why they entered the marina. Professor Caron said research shows that domoic acid poisoning can cause abnormal swimming in some kinds of fish.Harmful algae blooms are a common cause of fish kills. Domoic acid can also cause neurological disorders and death in animals that eat fish poisoned with the neurotoxin.9.Ten of Thousands of Technology Lovers Head South to AustinTens of thousands of people travel to Austin, Texas each year to attend the South by Southwest festival. The festival is most famous for its music and film presentations. In recent years it has also become one of the biggest new media events of the year.Last year more than fourteen thousand people from fifty-four countries attended the event. It is the place to learn about promising new technologies.Margie Newman describes the event as "a sea of Mac-toting, smartphone-obsessed, new media snobs on a mission to know what is next." Ms. Newman is a public relations professional in Washington D.C. She made her third trip to the South by Southwest festival this year. We spoke with her by phone at the festival.MARGIE NEWMAN: "When you can go to a place and not only see what's next and see how to better use what's already here, but also connect with people who love it as much as you do, it's just kind of a special thing. A lot of people call South by Southwest Interactive the geek spring break. And that's pretty accurate."South by Southwest Interactive has seen the successful launch of several products. It helped push Twitter into mainstream popularity in two thousand seven. In two thousand nine, a company called Foursquare launched its mobile networking service at the festival. The service lets friends tell other friends where they are by "checking in" using a mobile application or a text message. Foursquare's owners say they now have more than six and a half million users around the world.Margie Newman says quick response codes are big news at this year's festival. The codes turn URLs and text into barcode-like images that can be scanned using a mobile phone or a QR code reader.MARGIE NEWMAN: "It looks like a scanning device like when you're at the grocery store but it's a square. A lot of people aren't quite using QR codes for marketing just yet in mainstream.But you're seeing a lot of it here. It's very hot this year." Cloud computing is also expected to be a hot topic this year, as is group messaging. The five-day festival runs through March fifteenth. Hundreds of events are planned each day. They include speeches by some of the world's leading technology industry experts, hands-on training workshops and many group discussions.MARGIE NEWMAN: "Without a doubt I would say South by Southwest Interactive is the place to be if you are into digital new media. You don't want to miss it. And in fact, part of it is just being able to say you were here makes you one of the cool kids, even if you didn't go to one panel. Just having the badge that says you were here kind of makes you worth your salt if you're part of the new media landscape."。