2. 外语
  3. Animal Testing Anna stares at the computer screen and considers her options. In front of her are two shapes—a flower and a d

Animal Testing Anna stares at the computer screen and considers her options. In front of her are two shapes—a flower and a d

admin2012-07-05  39
问题                         Animal Testing
    Anna stares at the computer screen and considers her options. In front of her are two shapes—a flower and a diamond. If she picks the right one, she will be rewarded with bananas. The wrong choice will briefly switch the lights off in her glass box. She decides on the diamond and is plunged into darkness.
    During the next nine minutes, Anna makes the same mistake over and over again. The neuroscienti-sts (神经学家) who designed this experiment are testing how good Anna is at learning new rules. Over the past few weeks, she had learned that the diamond was her ticket to a sugary drink, but this is the first test in which the rules have been reversed. Most of the animals adapt quickly; but Anna is different.
    In March, she had precision brain surgery in which researchers destroyed a small area of her brain. She moves, eats and behaves normally around the other animals, but the experiments are showing that the specific brain region destroyed is crucial for subtle behavioral abilities.
    If Anna were human, this experiment would not be possible. But the studies carried out on her and the other marmosets (美洲产长尾猴) at one of the most controversial research centers in Britain are providing vital insights into the brain malfunctions that cause mental problems.
    Animal rights campaigners condemn this research as cruel and unnecessary. This Spring, the famous primatologist (灵长类动物学家) Dr. Jane Goodall asked the European Union to do more to find other routes to cures. The European Commission is reviewing Directive 86/609, which governs animal research across the EU. Goodall and groups who are against experiments with animals hope to pressure the commission to include a timetable to end primate (灵长类动物) testing altogether.
    Despite being a world-class neuroscientist, Jessica, who runs a secret marmoset facility at a leading British university, rarely talks about her job. Police have found her name on a hit list put together by animal rights extremists. She is afraid that if her work becomes more widely known, her home and family might be targeted. Jessica has never before talked to a journalist, but now she feels a duty to speak. " I’m fed up with the amount of misinformation that’s constantly put out," she said.
    She particularly objects to the photographs shown on anti-animal testing websites with monkeys terrified because protesters have broken in during the night; or images that are cut to make the cages look too small. They are often decades out of date, she says. " The disorders which we are trying to treat are crippling to people. I would love it if we could just tell the world what we do. "
    The marmosets live in nine rooms, in cages nearly three meters high that are full of ladders, beams and ropes. The cages are designed with the needs of this species in mind. The monkeys, which are bred here, live either in family groups of up to 15 or in pairs, as they would in the wild.
    " What we try to do is, as closely as possible, give them all the opportunities they would have in the wild," says Peter, the laboratory’s animal welfare officer. In the marmoset kitchen, he prepares the monkeys’ food. Their diet consists of egg and Complan sandwiches, along with pills that give them the correct balance of minerals. But Peter also includes a dried fruit-and-nut mix and fresh fruit.
    Groups who are against the use of animals in research claim that scientists force the monkeys to perform by starving them and not giving them water. Peter denies this. He says the animals receive a balanced diet, and breeding animals receive exactly the same diet as the experimental monkeys. " We limit the times when they have treats. But we are not starving the animals. Treating the animals badly would be counter-productive. Animals forced to take part in experiments would give unreliable results ," he says.
    For those who are against primate research, though, even the best conditions mean suffering. " We know that the intelligence and emotional needs of monkeys make even day-to-day life in a laboratory cage a serious animal rights issue—in addition to the horrifying suffering that can be caused by invasive brain studies or poisoning tests," said an animal rights spokesperson.
    This is a problem for many people who are uncomfortable with the idea of experimenting on the brains of creatures so evolutionarily close to ourselves. To explore how the monkeys’ brains work, the researchers must destroy parts of the brain tissue.
    The research in the lab is not aimed at testing specific new drugs against the monkey versions of human brain diseases, or how poisonous new products are. Tests are aimed at understanding the basic nerving architecture of primates (including us), so that treatments for brain diseases may become a possibility. One focus is on testing the monkeys’ behavioral flexibility and finding out which areas of the brain are responsible. It is these parts of the brain that are changed in conditions such as OCD(强迫症).
    OCD patients feel they have to repeat certain aspects of behavior, such as washing their hands. Anna , returning time and again to the wrong symbol in her computer test, shows a similar behavior, says Jessica. When OCD patients are given the same rule-changing task, they act in the same way. The difference with Anna is that one can work out which part of the brain is responsible for the behavior and so offer options for treating the symptoms in people.
    Jessica insists that the insights her team is providing into how the human brain works would not be possible any other way. No scientist would choose to work on animals if an alternative existed, she said. It is expensive and dangerous because of the extremes to which some who are against the work are prepared to go. " You need to do something for this huge number of people who suffer from these mental disorders. We can’t do that unless we understand how the brain controls our behavior. "
    Critics say using animals in research is old-fashioned science. "Urgent action is needed to improve the protection of animals, and to replace immoral and outdated animal experiments with non-animal techniques," said Dr. Gill Langley of the Dr Hadwen Trust, a non-animal medical research organization. She favors methods such as tissue culture, computer modeling and brain studies, which, she says, are more advanced and relevant to human patients.
Jessica insists that scientists would no longer choose to work on animals if______ .
选项
答案an altermative existed
解析 题干中用no longer表示否定，定位句中用no表示否定，两句句式相同，故可以直接使用原文中出现的an alternativeexisted作为答案。
转载请注明原文地址:https://jikaoti.com/ti/7bcFFFFM
0

大学英语四级

相关试题推荐
随机试题
最新回复(0)