男,76歲。左下肢間歇性跛行3年,加重1個(gè)月。既往史:高血壓病史8年,冠心病病史5年,曾行冠脈支架植入術(shù)。查體:BP150/90mmHg,左足蒼白,左足及左下肢皮溫明顯降低,左足背動(dòng)脈、腘動(dòng)脈搏動(dòng)消失,左股動(dòng)脈可觸及搏動(dòng),做可能的診斷是左下肢
A、急性動(dòng)脈栓塞C
暫無(wú)解析
Tom,withhisparents______toAmerica.They_____backintwoweeks.
Josephwasverylucky()withhislife;healmostdidnotgetoutoftheroom.
AsGilbertWhite,Darwin,andothersobservedlongago,allspeciesappeartohavetheinnatecapacitytoincreasetheirnumbersfromgenerationtogeneration.Thetaskforecologistsistountangletheenvironmentaandbiologicalfactorsthatholdthisintrinsiccapacityforpopulationgrowthincheckoverthelongrun.Thegreatvarietyofdynamicbehaviorsexhibitedbydifferentpopulationmakesthistaskmoredifficult:sompopulationsremainroughlyconstantfromyeartoyear;othersexhibitregularcyclesofabundanceandscarcity;stillothersvarywildly,withoutbreaksandcrashesthatareinsomecasesplainlycorrelatedwiththeweather,andinothercasesnot.Toimposesomeorderonthiskaleidoscopeofpatterns,oneschoolofthoughtproposesdividingpopulationsintotwogroups.Theseecologistspositthattherelativelysteadypopulationshavedensity-dependentgrowthparameters;thatis,ratesofbirth,death,andmigrationwhichdependstronglyonpopulationdensity.Thehighlyvaryingpopulationshavedensity-independentgrowthparameters,withvitalratesbuffetedbyenvironmentalevents;theseratesfluctuateinawaythatiswhollyindependentofpopulationdensity.Thisdichotomyhasitsuses,butitcancauseproblemsiftakentooliterally.Foronething,nopopulationcanbedrivenentirelybydensity-independentfactorsallthetime.Nomatterhowseverelyorunpredictablybirth,death,andmigrationratesmaybefluctuatingaroundtheirlong-termaverages,iftherewerenodensity-dependenteffects,thepopulationwould,inthelongrun,eitherincreaseordecreasewithoutbound(barringamiraclebywhichgainsandlossescanceledexactly)。Putanotherway,itmaybethatonaverage99percentofalldeathsinapopulationarisefromdensity-independentcauses,andonlyonepercentfromfactorsvaryingwithdensity.Thefactorsmakinguptheonepercentmayseemunimportant,andtheircausemaybecorrespondinglyhardtodetermine.Yet,whetherrecognizedornot,theywillusuallydeterminethelong-termaveragepopulationdensity.Inordertounderstandthenatureoftheecologist’sinvestigation,wemaythinkofthedensity-dependenteffectsongrowthparametersasthesignalecologistsaretryingtoisolateandinterpret,onethattendstomakethepopulationincreasefromrelativelylowvaluesordecreasefromrelativelyhighones,whilethedensity-independenteffectsacttoproducenoiseinthepopulationdynamics.Forpopulationsthatremainrelativelyconstant,orthatoscillatearoundrepeatedcycles,thesignalcanbefairlyeasilycharacterizedanditseffectsdescribed,eventhoughthecausativebiologicalmechanismmayremainunknown.Forirregularlyfluctuatingpopulations,wearelikelytohavetoofewobservationstohaveanyhopeofextractingthesignalfromtheoverwhelmingnoise.Butitnowseemsclearthatallpopulationsareregulatedbyamixtureofdensity-dependentanddensity-independenteffectsinvaryingproportions.
1.Theauthorofthetextisprimarilyconcernedwith
[A]Discussingtwocategoriesoffactorsthatcontrolpopulationgrowthandassessingtheirrelativeimportance.
[B]Describinghowgrowthratesinnaturalpopulationsfluctuateovertimeandexplainingwhythesechangesoccur.
[C]Proposingahypothesisconcerningpopulationsizeandsuggestingwaystotestit.
[D]Posingafundamentalquestionaboutenvironmentalfactorsinpopulationgrowthandpresentingsomecurrentlyacceptedanswer.
2.Itcanbeinferredfromthetextthattheauthorconsidersthedichotomydiscussedtobe
[A]Applicableonlytoerraticallyfluctuatingpopulations.
[B]instrumental,butonlyifitslimitationsarerecognized.
[C]Dangerouslymisleadinginmostcircumstances.
[D]Acompleteandsufficientwaytoaccountforobservedphenomena.
3.tothetext,allofthefollowingbehaviorshavebeenexhibitedbydifferentpopulationsEXCEPT
[A]Roughlyconstantpopulationlevelsfromyeartoyear.
[B]Regularcyclesofincreasesanddecreasesinnumbers.
[C]Erraticincreasesinnumberscorrelatedwiththeweather.
[D]Uncheckedincreasesinnumbersovermanygenerations.
4.Thediscussionconcerningpopulationinthethirdparagraphservesprimarilyto
[A]Demonstratethedifficultiesecologistsfaceinstudyingdensity-dependentfactorslimitingpopulationgrowth.
[B]Advocatemorerigorousstudyofdensity-dependentfactorsinpopulationgrowth.
[C]Provethatthedeathratesofanypopulationareneverentirelydensity-independent.
[D]underlinetheimportanceofevensmalldensity-dependentfactorsinregulatinglong-termpopulationdensities.
5.Inthetext,theauthordoesallofthefollowingEXCEPT
[A]Citetheviewsofotherbiologists.
[B]Defineabasicproblemthatthetextaddresses.
[C]Presentconceptualcategoriesusedbyotherbiologists.
[D]Describetheresultsofaparticularstudy.
Themajorityofsuccessfulseniormanagersdonotcloselyfollowtheclassicalrationalmodeloffirstclarifyinggoals,assessingtheproblem,formulatingoptions,estimatinglikelihoodsofsuccess,makingadecision,andonlythentakingactiontoimplementthedecision.Rather,intheirday-by-daytacticalmaneuvers,theseseniorexecutivesrelyonwhatisvaguelytermedintuitiontomanageanetworkofinterrelatedproblemsthatrequirethemtodealwithambiguity,inconsistency,novelty,andsurprise;andtointegrateactionintotheprocessofthinking.Generationsofwritersonmanagementhaverecognizedthatsomepracticingmanagersrelyheavilyonintuition.Ingeneral,however,suchwritersdisplayapoorgraspofwhatintuitionis.Someseeitastheoppositeofrationality;othersviewitasanexcuseforcapriciousness.Isenberg'srecentresearchonthecognitiveprocessesofseniormanagersrevealsthatmanagers'intuitionisneitherofthese.Rather,seniormanagersuseintuitioninatleastfivedistinctways.First,theyintuitivelysensewhenaproblemexists.Second,managersrelyonintuitiontoperformwell-learnedbehaviorpatternsrapidly.Thisintuitionisnotarbitraryorirrational,butisbasedonyearsofpainstakingpracticeandhands-onexperiencethatbuildskills.Athirdfunctionofintuitionistosynthesizeisolatedbitsmofdataandpracticeintoanintegratedpicture,ofteninanAha!experience.Fourth,somemanagersuseintuitionasacheckontheresultsofmorerationalanalysis.Mostseniorexecutivesarefamiliarwiththeformaldecisionanalysismodelsandtools,andthosewhousesuchsystematicmethodsforreachingdecisionsareoccasionallyleeryofsolutionssuggestedbythesemethodswhichruncountertotheirsenseofthecorrectcourseofaction.Finally,managerscanuseintuitiontobypassin-depthanalysisandmoverapidlytoengenderaplausiblesolution.Usedinthisway,intuitionisanalmostinstantaneouscognitiveprocessinwhichamanagerrecognizesfamiliarpatterns.Oneoftheimplicationsoftheintuitivestyleofexecutivemanagementisthatthinkingisinseparablefromacting.Sincemanagersoftenknowwhatisrightbeforetheycananalyzeandexplainit,theyfrequentlyactfirstandexplainlater.Analysisisinextricablytiedtoactioninthinking/actingcycles,inwhichmanagersdevelopthoughtsabouttheircompaniesandorganizationsnotbyanalyzingaproblematicsituationandthenacting,butbyactingandanalyzingincloseconcert.Giventhegreatuncertaintyofmanyofthemanagementissuesthattheyface,seniormanagersofteninstigateacourseofactionsimplytolearnmoreaboutanissue.Theythenusetheresultsoftheactiontodevelopamorecompleteunderstandingoftheissue.Oneimplicationofthinking/actingcyclesisthatactionisoftenpartofdefiningtheproblem,notjustofimplementingthesolution.
1.Accordingtothetext,seniormanagersuseintuitioninallofthefollowingwaysEXCEPTto
[A]Speedupofthecreationofasolutiontoaproblem.
[B]Identifyaproblem.
[C]Bringtogetherdisparatefacts.
[D]Stipulatecleargoals.
2.Thetextsuggestswhichofthefollowingaboutthewritersonmanagementmentionedinline1,paragraph2
[A]Theyhavecriticizedmanagersfornotfollowingtheclassicalrationalmodelofdecisionanalysis.
[B]Theyhavenotbasedtheiranalysesonasufficientlylargesampleofactualmanagers.
[C]Theyhavereliedindrawingtheirconclusionsonwhatmanagerssayratherthanonwhatmanagersdo.
[D]Theyhavemisunderstoodhowmanagersuseintuitioninmakingbusinessdecisions.
3.ItcanbeinferredfromthetextthatwhichofthefollowingwouldmostprobablybeonemajordifferenceinbehaviorbetweenManagerX,whousesintuitiontoreachdecisions,andManagerY,whousesonlyformaldecisionanalysis
[A]ManagerXanalyzesfirstandthenacts;ManagerYdoesnot.
[B]ManagerXcheckspossiblesolutionstoaproblembysystematicanalysis;ManagerYdoesnot.
[C]ManagerXtakesactioninordertoarriveatthesolutiontoaproblem;ManagerYdoesnot.
[D]ManagerYdrawsonyearsofhands-onexperienceincreatingasolutiontoaproblem;ManagerXdoesnot.
4.Thetextprovidessupportforwhichofthefollowingstatements
[A]Managerswhorelyonintuitionaremoresuccessfulthanthosewhorelyonformaldecisionanalysis.
[B]Managerscannotjustifytheirintuitivedecisions.
[C]Managers''intuitionworkscontrarytotheirrationalandanalyticalskills.
[D]Intuitionenablesmanagerstoemploytheirpracticalexperiencemoreefficiently.
5.Whichofthefollowingbestdescribestheorganizationofthefirstparagraphofthetext
[A]Anassertionismadeandaspecificsupportingexampleisgiven.
[B]Aconventionalmodelisdismissedandanalternativeintroduced.
[C]Theresultsofrecentresearchareintroducedandsummarized.
[D]Twoopposingpointsofviewarepresentedandevaluated.
Hewasluredintoacrimehewouldnot____________havecommitted.