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1、赵过：外报阅读2012-3Passage1AnimaltestingBenicetomice……andtheymayreturnthefavourApr7th2012
2、fromtheprinteditionONLYonedrugofeverytensuccessfullytestedinlaboratoryanimalsendsupworkinginpeople.Onereason,ofcourse,isthatmicearenotmen.Another,though,mighthavetodowiththefactthatwhereashumanpatientsareaffordeda
3、llmannerofcreaturecomforts,theiranimalproxiesarenot.Althoughmedicalscience’sfavouritecrittersrelishtemperaturesofalittleover30°C,laboratoriesroutinelykeepthematfiveortendegreesbelowthat.Thisisnotinordertotorturethebeastsbut,rather,becausewhenkeptwarmtheyareunmanageablyaggressive.Thedownsideisthat
4、theyhavetoeatmorethantheyotherwisewould,inordertokeeptheirbodieswarm.Thatchangestheirphysiology.Andthatinturnaltersthewaytheymetabolisedrugs,withpossiblyconfusingresults.JosephGarner,ofStanfordUniversity,thinkstheansweristokeepthelabscool,butletmicecopewiththelowtemperaturesastheydointheirnatural
5、habitat:notbyeatingmorebutbybuildingnests.Sofar,though,noonehasaclearideaofhowmuchnestingmaterialisneededtokeepmicehappy.DrGarnerandhiscolleaguesthereforedecidedtofindout.TheyhavejustreportedtheirresultsinthePublicLibraryofScience.DrGarnerandhisteamleteachoftheirmice,36malesandasmanyfemalesfromth
6、reestrainscommonlyusedintrials,roamfreeintwocagesconnectedbyanarrowtube.Onecagewaskeptconstantatoneofsixtemperaturesbetween20°Cand35°C.Theotherwasmaintainedat20°Cbutwasstockedwithuptotengramsoffinelyshreddedpaper,whichthemicecouldusetoweaveanest.Theideawastocheckwhethertheanimalswouldratherbuilda
7、nestinthecoolercageormovetothewarmerone,possiblytuggingnestingmaterialalongwiththemstrandbystrand.Theresearchersfoundthattherodents’preferencesvariedslightlybetweenstrains,aswellasbetweensexes(withfemalespartialtohighertemperatures,possiblybecauseoftheirthinnerprotectivelayeroffat),confirmingthat
8、thereisnosinglesetofconditionsinwhichallmicefeelcosy.Ingeneral,though,withlittlenestingmaterialaround,theanimalslaboriouslycarriedstrandsofpaperovertothewarmerspot,oneortwoatatime.Butleaveatleastsixgramsofpaperinthechi
