大学英语自学教程 下册 un11

[04:07.72]The eventual aim of computer modeling
[04:12.68]is to reduce the number of animals used in experiments.
[04:15.62]计算机模型的最终目标是减少用于实验的动物数量.
[04:18.56]The Lethal Dose 50 test (LD50) may also be replaced
[04:22.79]药剂致死剂量50试验(LD50)也可以被代替.
[04:27.02]In the original test,all the animals in a test group are given a substance
[04:33.58]until half of them die.
[04:35.60]在过去的实验中,实验群中所有的动物被喂给一种物质,直到其中一半死亡.
[04:37.63]The test indicates toxicity.
[04:39.75]这个实验表明其毒性.
[04:41.86]A method using a fixed amount,
[04:46.22]which gives the same eventual information
[04:48.80]一种用固定的数量,可以得出同样结论,却用较少动物,
[04:51.37]but uses fewer animalsand does not require that they die,
[04:57.74]may replace the LD50.
[04:59.92]而不使他们死亡的方法可能代替药剂致死剂量50实验.
[05:02.11]Many other new techniques are now available that enable more research
[05:05.23]现在已有许多其他的技术,可使更多的研究工作在试管中进行,
[05:08.35]to be done in the test tube
[05:12.11]to see if chemicals produce harmfulbiological effects.
[05:15.19]去发现化学药品是否产生有害的生物作用.
[05:18.28]The number of animals used in laboratory testsh
[05:23.92]as declined over the last 20 years.
[05:26.56]  过去的20多年里,实验室内里实验中使用的动物数量已减少了.
[05:29.20]This is partly due to alternatives
[05:31.38]这部分是由于何供选择的办法多了,
[05:33.56]and partly to the fact that experiments are better designed
[05:36.48]部分是由于实验设计得更好,因为使用更健康的动物能产生更好的实验结果,
[05:39.41]so fewer need to be used
[05:41.47]所以用的动物更少了.
[05:43.54]healthier animals provide better experimental results.
[05:46.21]因为使用更健康的动物能产生更好的实验结果,
[05:48.89]For example,it used to take 36 monkeys to test a sample of polio vaccine
[05:53.07]例如,过去常用36只狮子来实验脊髓类质炎疫苗样品,
[05:57.25]now it takes only 22.
[05:59.59]现在只用22只.
[06:01.93]Also,lack of money has reduced the number of animals used
[06:05.15]缺少资金已使所使用的动物数量减少了
[06:08.38]they are expensive to buy and expensive to keep.
[06:11.06]---购买和饲养动物都很昂贵.
[06:13.73]Birmingham University now has Britain's first department of Biomedical Ethics.
[06:17.36]  伯明翰大学现在设有英国首家生物医学伦理学系.
[06:21.00]Professor David Morton of the department is involved in animal research
[06:24.43]系里的大卫.莫顿教授从事动物研究,
[06:27.87]and is concerned with reducing animal suffering as much as possible.
[06:31.34]对尽可能地减少动物的痛苦很关心.
[06:34.81]Animals spend 95% of their time in their cages
[06:37.90]动物们在矮子里度过了它们95%的时间,
[06:40.98]and refinement also means making their lives better when not undergoing tests.
[06:45.02]改良也意味着不进行实验时使它们活地更好些.
[06:49.05]This includes keeping them in more suitable cages,
[06:51.62]这包括在更舒适的矮子时喂养他们,
[06:54.20]allowing social animals like dogs to live together
[06:57.08]允许像狗一们的友善的动物和他们生活在一起,
[06:59.97]and trying to reduce the boredom that these animals can experience.
[07:03.20]尽量减少这些动物可能经历的烦恼.
[07:06.42]In Professor Morton's laboratory,rabbits live together in large runs
[07:09.91]  在莫顿教授的实验里,大批兔子一起生活,
[07:13.40]filled with deep litter and boxes that they can hide in.
[07:16.43]到处是厚厚的干草和它们可以藏进去的箱子.
[07:19.46]The researchers have also refined some experiments.
[07:22.24]研究者们还改进了一些实验.
[07:25.02]In the US,one experiment in nerve regeneration
[07:30.80]involves cutting a big nerve in a rat's leg,leaving its leg paralyscd.
[07:34.57]在美国神经再生方面的实验要切断一条老鼠腿里的大神经,让它的腿瘫痪.
[07:38.34]In Morton's lab,the researcher cuts a small nerve in the foot
[07:41.53]在莫顿的实验室时里,研究者们只切断鼠脚里的一条小神经.
[07:44.72]He can see if it can regrow and the rat can still run around its cage
[07:48.40]他可以看到神经是否可以再生,而老鼠仍在笼子里四处跑.
[07:52.08]Even with these new developments in research,
[07:54.46]尽管使用了这些研究开发的新成果,
[07:56.84]only a tiny proportion of all tests are donewithout using animals at some stage.