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1、CellsCellsTemperatureTemperature細胞與溫度細胞與溫度muchnarrowerlimitsmarktheboundariesofeffectivefunctioning.Enzymesystemsofmammalsbirdsaremostefficientonlywithinanarrowrangearound37Cadepartureofafewdegreesfromthisvalueseriouslyi

2、mpairstheirfunctioning.Eventhoughcellscansurvivewiderfluctuationstheintegratedactionsofbodilysystemsareimpaired.Otheranimalshaveawidertolerancefchangesofbodilytemperature.Fcenturiesithasbeenrecognizedthatmammalsbirdsdiff

3、erfromotheranimalsinthewaytheyregulatebodytemperature.Waysofacterizingthedifferencehavebecomemeaccuratemeaningfulovertimebutpopularterminologystillreflectstheolddivisioninto“warmblooded”“coldblooded”specieswarmbloodedinc

4、ludedmammalsbirdswhereasallothercreatureswereconsideredcoldblooded.Asmespecieswerestudieditbecameevidentthatthisclassificationwasinadequate.Afencelizardadesertiguana—eachcoldbloodedusuallyhasabodytemperatureonlyadegreetw

5、obelowthatofhumanssoisnotcold.Therefethenextdistinctionwasmadebetweenanimalsthatmaintainaconstantbodytemperaturecalledhome0thermsthosewhosebodytemperaturevarieswiththeirenvironmentscalledpoikilotherms.Butthisclassificati

6、onalsoprovedinadequatebecauseamongmammalstherearemanythatvarytheirbodytemperaturesduringhibernation.Furthermemanyinvertebratesthatliveinthedepthsoftheoceanneverexperiencechangeinthedepthsoftheoceanneverexperiencechangein

7、thechillofthedeepwatertheirbodytemperaturesremainconstant.細胞只能在一定的溫度范圍內(nèi)存活，而進一步保證它們有效工作的溫度范圍就更小了。哺乳動物和鳥類的酶系統(tǒng)只能在37℃左右的很小范圍內(nèi)才能有效工作。與此相差僅幾度的溫度都會大大削弱它們的工作效率。盡管溫度變化更大時細胞仍能存活，但機體系統(tǒng)的整體運行能力卻被削弱了。其它動物對體溫的變化有更強的適應(yīng)性。幾個世紀以來，人們就認識到哺乳動

8、物和鳥類調(diào)節(jié)體溫的方式與其它動物不同。隨著時間的推移，人們對這種差異的描述越來越精確和有意義，但是“暖血動物“和“冷血動物“這一古老的分類方式至今仍在大眾詞匯中有所反映。暖血動物包括哺乳動物和鳥類，其它動物統(tǒng)統(tǒng)被視為冷血動物。但是對更多物種進行的研究表明這種分類顯然是不適當?shù)?。美洲一種小型蜥蜴和沙漠鬣蜥同屬冷血動物，但實際上它們的體溫通常只比人類的體溫低1～2度，因此并不是真正的冷血。因此又出現(xiàn)了恒溫動物(即保持恒定體溫的動物)和變溫動

9、物(即體溫隨外界環(huán)境的變化而改變的動物)這一區(qū)分方式。但這種分類也不恰當。因為有不少哺但你并不是整夜都保持這種沉睡狀態(tài)。入睡后約但你并不是整夜都保持這種沉睡狀態(tài)。入睡后約8080分鐘左右，你的大腦運動水分鐘左右，你的大腦運動水平會再度略有提高。平會再度略有提高。δ節(jié)奏消失，并被腦電波的運動圖形取代。你的眼睛會節(jié)奏消失，并被腦電波的運動圖形取代。你的眼睛會在閉著的眼瞼下迅速轉(zhuǎn)動，就好象你在看著眼前發(fā)生的什么事情。這種迅速的閉著的眼瞼下迅速

10、轉(zhuǎn)動，就好象你在看著眼前發(fā)生的什么事情。這種迅速的眼球運動持續(xù)約眼球運動持續(xù)約8～1515分鐘，這一階段睡眠被稱之為快速眼動分鐘，這一階段睡眠被稱之為快速眼動(REM)(REM)睡眠。在睡眠。在REMREM睡眠階段，你的肢體會很快再度放松，呼吸也再次放慢并變得有節(jié)奏，你睡眠階段，你的肢體會很快再度放松，呼吸也再次放慢并變得有節(jié)奏，你會輕松地從第一階段滑入第四階段睡眠會輕松地從第一階段滑入第四階段睡眠直到大約直到大約8080分鐘后重新接近

11、清醒狀態(tài)。分鐘后重新接近清醒狀態(tài)。FolkFolkCulturesCultures民間文化民間文化(4)Afolkcultureisasmallisolatedcohesiveconservativenearlyselfsufficientgroupthatishomogeneousincustomracewithastrongfamilyclanstructurehighlydevelopedrituals.derismaintain

12、edthroughsanctionsbasedinthereligionfamilyinterpersonalrelationshipsarestrong.Traditionisparamountchangecomesinfrequentlyslowly.Thereisrelativelylittledivisionoflabintospecializedduties.Rathereachpersonisexpectedtoperfma

13、greatvarietyoftasksthoughdutiesmaydifferbetweenthesexes.Mostgoodsarehmadesubsistenceeconomyprevails.Individualismisweaklydevelopedinfolkculturesasaresocialclasses.Unalteredfolkculturesnolongerexistinindustrializedcountri

14、essuchastheUnitedStatesCanada.PerhapsthenearestmodernequivalentinAngloAmericaistheAmishaGermanAmericanfarmingsectthatlargelyrenouncestheproductslabsavingdevicesoftheindustrialage.InAmishareashsedrawnbuggiesstillserveasal

15、ocaltransptationdevicethefaithfularenotpermittedtoownautomobiles.TheAmish’scentralreligiousconceptofDemut“humility”clearlyreflectstheweaknessofindividualismsocialclasssotypicaloffolkculturesthereisacrespondingstrengthofA

16、mishgroupidentity.RarelydotheAmishmarryoutsidetheirsect.ThereligionavarietyoftheMennonitefaithprovidestheprincipalmechanismfmaintainingder.Bycontrastapopularcultureisalargeheterogeneousgroupoftenhighlyindividualisticapro

17、nouncedmanyspecializedprofessions.Secularinstitutionsofcontrolsuchasthepolicearmytaketheplaceofreligionfamilyinmaintainingderamoneybasedeconomyprevails.Becauseofthesecontrasts“popular”maybeviewedasclearlydifferentfrom“fo