首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Cheating in sport is as old as sport itself. The athletes of ancient Greece used potions to fortify themselves before a contest,
Cheating in sport is as old as sport itself. The athletes of ancient Greece used potions to fortify themselves before a contest,
admin
2013-08-05
28
问题
Cheating in sport is as old as sport itself. The athletes of ancient Greece used potions to fortify themselves before a contest, and their modern counterparts have everything from anabolic steroids and growth hormones to doses of extra red blood cells with which to invigorate their bodies. These days, however, such stimulants are frowned on, and those athletes must therefore run the gauntlet of organizations such as the World Anti-Doping Agency (WADA), which would rather that athletes competed without resorting to them.
The agencies have had remarkable success. Testing for anabolic steroids (in other words, artificial testosterone) was introduced in the 1970s, and the incidence of cheating seems to have fallen dramatically as a result. The tests, however, are not foolproof. And a study just published in the Journal of Clinical Endocrinology & Metabolism by Jenny Jakobsson Schulze and her colleagues at the Karolinska Institute in Sweden suggests that an individual’s genetic make-up could confound them in two different ways. One genotype, to use the jargon, may allow athletes who use anabolic steroids to escape detection altogether. Another may actually be convicting the innocent.
The test usually employed for testosterone abuse relies on measuring the ratio of two chemicals found in the urine: testosterone glucuronide (TG) and epitestosterone glucuronide (EG). The former is produced when testosterone is broken down, while the latter is unrelated to testosterone metabolism, and can thus serve as a reference point for the test. Any ratio above four of the former to one of the latter is, according to official Olympic policy, considered suspicious and leads to more tests.
However, the production of TG is controlled by an enzyme that is, in turn, encoded by a gene called UGT2B17. This gene comes in two varieties, one of which has a part missing and therefore does not work properly. A person may thus have none, one or two working copies of UGT2B17, since he inherits one copy from each parent. Dr. Schulze guessed that different numbers of working copies would produce different test results. She therefore gave healthy male volunteers whose genes had been examined a single 360mg shot of testosterone (the standard dose for legitimate medical use) and checked their urine to see whether the shot could be detected.
The result was remarkable. Nearly half of the men who carried no functional copies of UGT2B17 would have gone undetected in the standard doping test. By contrast, 14% of those with two functional copies of the gene were over the detection threshold before they had even received an injection. The researchers estimate this would give a false-positive testing rate of 9% in a random population of young men.
Dr. Schulze also says there is substantial ethnic variation in UGT2B17 genotypes. Two-thirds of Asians have no functional copies of the gene (which means they have a naturally low ratio of TG to EG), compared with under a tenth of Caucasians—something the anti-doping bodies may wish to take into account.
In the meantime, Dr. Schulze’s study does seem to offer innocents a way of defending themselves. Athletes traveling to Beijing for the Olympic games may be wise to travel armed not only with courage and the "spirit of Olympianism", but also with a copy of their genetic profile, just in case.
According to official Olympic policy, which of the following ratio between TG and EG is considered suspicious?
选项
A、1 : 1.
B、2.5 : 1.
C、3.3 : 1.
D、4.5 : 1.
答案
D
解析
第3段最后一句提到,根据奥林匹克官方政策,如果前者与后者的比值大于4:1,就有使用兴奋剂的嫌疑,各选项中只有D大于4:1,因此应选D。
转载请注明原文地址:https://kaotiyun.com/show/DsZO777K
0
专业英语八级
相关试题推荐
AccordingtoDr.Adams,whatdoesthetitleofhisbooksuggest?
Inthelate1960smanypeopleinNorthAmericaturnedtheirattentiontoenvironmentalproblems,andnewsteel-and-glassskyscra
Thecentralproblemoftranslatinghasalwaysbeenwhethertotranslateliterallyorfreely.Theargumenthasbeengoingsincea
Thecentralproblemoftranslatinghasalwaysbeenwhethertotranslateliterallyorfreely.Theargumenthasbeengoingsincea
Insixteenth-centuryItalyandeighteenth-centuryFrance,waningprosperityandincreasingsocialunrestledtherulingfamilies
AimlessnesshashardlybeentypicalofthepostwarJapanwhoseproductivityandsocialharmonyaretheenvyoftheUnitedStates
OnlineUniversityDegreesThroughDistanceEducationMoreandmoreuniversitiesaroundtheworldareofferingonlinelanguageco
Thereexistsasocialandculturaldisconnectionbetweenjournalistsandtheirreaders,whichhelpsexplainwhythe"standardt
Thereexistsasocialandculturaldisconnectionbetweenjournalistsandtheirreaders,whichhelpsexplainwhythe"standardt
Thereexistsasocialandculturaldisconnectionbetweenjournalistsandtheirreaders,whichhelpsexplainwhythe"standardt
随机试题
女,35岁。因月经过多且经期延长,贫血,血红蛋白仅56g/L,而决定行全子宫切除术。术前主刀医师在考虑手术各步注意事项时,下列哪项可不必顾虑
A.鸡内金B.莱菔子C.神曲D.山楂E.麦芽
注册建筑师有下列哪种情形时,其注册证书和执业印章继续有效?[2010年第67题]
“工程竣工总结"属于建造师签章的()类文件。
层层深入找出可能影响工程质量的原因,可采用( )法。
企业全面预算通常包括()。
艺术是人类通过借助特殊的物质材料与工具,运用一定的审美能力和技巧进行的一种创造性劳动。以艺术作品的内容特征为依据,可以将艺术分为表现艺术和再现艺术。表现艺术的内容侧重于传达主体的审美感受或情感体验,而再现艺术以再现客观事物的真实形态为主要目的。根据上述定义
微分方程的通解是()
下面关于U盘的描述中,错误的是()。
ThePeakTimeforEverythingA)Couldyoupackmoreintoeachdayifyoudideverythingattheoptimaltime?Agrowingbodyofre
最新回复
(
0
)