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首页 结论:吃水果

结论:吃水果.pdf

结论:吃水果

773885559
2011-04-15 0人阅读 举报 0 0 暂无简介

简介:本文档为《结论:吃水果pdf》,可适用于自然科学领域

ThereisgrowingconcernabouttheeffectsofmanmadenoiseonmarinelifeInparticular,marinemammalsthatusesoundtocommunicate,navigate,anddetectpredatorsandpreymaytrytoavoidloudsoundsourcesuptotensofkilometresawayHere,inastudyconductedincooperationwiththeUSNavy,weshowthatthesingingbehaviourofmalehumpbackwhaleswasalteredwhentheywereexposedtoLFA(lowfrequencyactive)sonarAsthesongofthesewhalesisassociatedwithreproduction,widespreadalterationoftheirsingingbehaviourmightaffectdemographicparameters,oritcouldrepresentastrategytocompensateforinterferencefromthesonarDuringthebreedingseasonmalehumpbackwhalessinglong,complexsongsthatarethoughttobesexualdisplaysSongsconsistofaseriesofthemes,progressinginapredictableorder,thatmayrepeatforseveralhoursWeusedasmallobservationvesseltofindsinginghumpbacksandconductfocalsampling,recordingbehaviourbefore,duringandafterplayback(Strictlyspeaking,wehaveevaluatedtheadditionalimpactthatLFAsoundshaveonasingingwhalethatisalreadybeingfollowed)Werecordedthevocalbehaviourofeachfocalsingercontinuouslyforseveralhoursusingatowed,calibratedhydrophonearrayWhenthewhalewasatthesurface,observerssampledvisiblebehaviourPhotographsofflukeanddorsalfinfeaturesconfirmedthewhale’sidentitythroughouteachfollowAtleasttwosongswererecordedbeforetheobservationvesselrequestedtheUSNavyRVCoryChouesttotransmitten(inonecasefour)sLFAsignalsatminintervalsThesonarwasbroadcastatlessthanfullstrength,andnofocalsingerwasexposedtoasignallouderthandB(withrespecttomPa)SixteensingerswerefollowedduringplaybacksInninefollows,thewhalesangcontinuouslythroughouttheplaybackinfourthesingerstoppedwhenhejoinedotherwhales(typicalofnormalsocialinteraction)andinfivethesingerstopped,presumablyinresponsetotheplaybackWerecordedatleastonecompletesonginallconditionsfromsixindividuals,andpooledthesongsofeachofthetwoindividualsthatweresubjectsintwoexperimentsForthesesixwhales,wemeasuredthedurationandthemestructureofsongspectrograms,comparingsongdurationinthethreeconditionsusinganalysisofvarianceOnaverage,humpbackwhales’songswerelongerduringLFAplaybacks(Fig)aparticularlystrongresult,giventhelowpowerofthetestandsmallsamplesizeSongdurationreturnedtonormalafterexposure,suggestingthatthisresponsehasalimiteddurationTherewaslittledifferenceinthelikelihoodofanaberrantthemetransitionacrossexposureconditions(x,P),indicatingthatlongsongsresultedfromlongerthemeswithinanormalsongstructureAcrossthesixsingers,maximumreceivedlevelofthesonaratthewhaledidnotcorrelatepositivelywitheithertheincreaseinmeansongdurationfrompreexposuretoexposurecondition(r)orwiththesubsequentdecreasefromexposuretopostexposurecondition(r)WesuggestthathumpbackssanglongersongsduringLFAsonartransmissionstocompensateforacousticinterferenceOurstudyshowsthatitispossibletomeasurethebehaviouralresponsesofindividualwhalesincontrolledexperimentsatseaPatrickJOMiller*,NicolettaBiassoni*,AmySamuels*†,PeterLTyack**BiologyDepartment,WoodsHoleOceanographicInstitution,WoodsHole,Massachusetts,USA†DanielFandAdaLRiceConservationBiologyandResearchCenter,ChicagoZoologicalSociety,Brookfield,Illinois,USARichardson,WJ,Greene,CRJr,Malme,CIThomson,DHMarineMammalsandNoise(Academic,SanDiego,)Waters,MAUSFederalRegister,–()Tyack,PLBehavEcolSociobiol,–()Payne,RMcVay,SScience,–()Altmann,JBehaviour,–()Miller,PJTyack,PLDeepSeaResII,–()Katona,SetalinTheBehaviorofMarineMammals(edsWinn,HEOlla,BL)–(Plenum,NewYork,)Zar,JHBiostatisticalAnalysis(PrenticeHall,EnglewoodCliffs,NJ,)Lehmann,ELAnnMathStat,–()briefcommunicationsNATURE|VOL|JUNE|wwwnaturecomWhalesongslengtheninresponsetosonarMalehumpbacksmodifytheirsexualdisplayswhenexposedtomanmadenoisePreDuringPostExposureconditionSongduration(min)FigureDurationofsongs(sem)producedbyhumpbacksbefore,duringandafterexposuretoLFAsonartransmissions(bold,filleddiamonds,meanofallsixsingersothersymbols,individualsingers)ThemaximumreceivedlevelofthesonaratthewhalerangedfromtodBremPaSongsweregroupedintheexposureconditionifasonartransmissionoccurredatanypointduringthesongTheaveragenumberofsongspersingerinthepreexposure,exposureandpostexposureconditionswas,and,respectivelyDifferenceswereassessedusingamixedmodelanalysisofvariancetreatingexposureconditionasafixedfactor,whaleidentityasarandomfactor,andeachsongdurationasanindependentobservationTheeffectofexposureconditiononsongdurationwasstatisticallysignificantatP(F,,power,n)NutritionAntioxidantactivityoffreshapplesVitaminCisusedasadietarysupplementbecauseofitsantioxidantactivity,althoughahighdose(mg)mayactasaprooxidantinthebody,Hereweshowthatgoffreshappleshasanantioxidantactivityequivalentto,mgofvitaminC,andthatwholeappleextractsinhibitthegrowthofcolonandlivercancercellsinvitroinadosedependentmannerOurresultsindicatethatnaturalantioxidantsfromfreshfruitcouldbemoreeffectivethanadietarysupplementApplesoftheRedDeliciousvarietywereextractedusingacetoneandtheircontentofphenolicsandflavonoidsdetermined,:theextractscontainedandmgphenolics,andandmgflavonoidspergappleswithandwithoutskin,respectivelyThereareknowntobemorephenolicsintheskinsofapplesthanintheflesh,andquercetinglycosidesarefoundonlyintheskinsWemeasuredthetotalantioxidantactivityofapplesbyusingthetotaloxyradicalscavengingcapacity(TOSC)assayandfoundthatappleswithskinhadahigherTOSCvaluethanappleswithoutskin(Figa)ThetotalantioxidantactivityofgappleswithskinwasTOSC(mmolvitaminCequivalents)thatis,the©MacmillanMagazinesLtdMarianVEberhardt,ChangYongLee,RuiHaiLiuDepartmentofFoodScience,StockingHall,CornellUniversity,Ithaca,NewYork,USAemail:RLcornelleduPodmore,IDetalNature,()Herbert,VetalJNutr,S–S()Singleton,VLRossi,JAJrAmJEnolViticult,–()Zhisen,J,Mengcheng,TJianming,WFoodChem,–()Burda,S,Oleszek,WLee,CYJAgricFoodChem,–()Winston,GW,Regoli,F,Dugas,AJ,Fong,JHBlanchard,KAFreeRadBiolMed,–()USDANutrientDatabaseforStandardReference()Wang,H,Cao,GPrior,RLJAgricFoodChem,–()Lunec,JJIntFedClinChem,–()Cory,AH,Owen,TC,Barltrop,JACory,JGCancerCommun,–()andonnutrientavailabilityanduptakeduringsummer,ratherthanoncambialcelldivisionFromtreeringanalysisacrossseveralsitesintheSiberiansubarctic,Vaganovetalprovideevidencethatannualvariabilityinmeanringwidthisdeterminedbythedateofthethawthroughitsinfluenceonthedateofcambialinitiation,aswellasbytemperatureduringthesubsequentearlygrowingseasonVariabilityinannualnetecosystemproduction(NEP)isalsolargelydeterminedbythetimingofthethaw,whichenablestheNEPtoswitchimmediatelyandrapidlyfromadailylosstoadailygainofCOOurownobservationsonblacksprucetreesattheBoreasSouthernStudyAreashowthatwhenairtemperatureexceeds°Candtheoverlyingsnowstartstomelt,meltwaterpercolatesdownintothesoil,thetemperatureoftheuppersoilhorizonsrisestowards°C,andtheswitchfromasmallnetdailylossofcarbontoalargenetgainoccursoverjustafewdaysInborealconifers,theavailabilityofsoilwaterisaprerequisitefortherecoveryofphotosyntheticcapacityinspringandearlysummerTheeffectoffrozensoilsonannualCOuptakebyNorwayspruceat°Nisparticularlydramaticbecause,beforethethaw,dailysolarradiationisalreadysubstantialandeffectivelybeingwastedfromtheperspectiveofCOcaptureThus,COuptakeissynchronizedandstronglystimulatedbythethaw,andafterwards,onceacriticaltemperaturesumisreached,cambialactivityandNEPincreasetogetherasthetemperaturerisesSuchobservationsrelatedtothepoorgrowthoftreesinborealforestshaveledtothepresumptionthattheirgrowthisconstrainedbytemperatureBycontrastwithtemperateandtropicalforests,borealforesttreesaresmallinrelationtotheirageandconiferousborealforestshaveaverylownetprimaryproductionofabouttonnesofcarbonhayr(refs,)Toinvestigatetheextenttowhichlowtemperatureistheprimarycontrollingvariable,alongtermnutrientoptimizationandirrigationexperimentonNorwaysprucewassetupatFlakaliden(°N)inSwedenSince,wehaveappliedcompletefertilizerdailythrougheverygrowingseasoneitherinirrigationwaterorasasinglesoliddoseatthestartofthegrowingseasonWefoundthatgrowthonthefertilizedplots(withorwithoutirrigation)increasedbyafactoroffour(Figa),soairtemperaturecannotbethemajordirectconstraintontreegrowthHowever,temperaturemaybeinfluencingtreegrowthindirectlythroughthelengthofthegrowingseasonandbyitseffectsondecompositionofsoilorganicNATURE|VOL|JUNE|wwwnaturecomantioxidantvalueofgapplesisequivalentto,mgofvitaminCGiventhattheaveragevitaminCcontentinfreshappleswithskinismgperg(ref)andthatthetotalantioxidantactivityofmgvitaminC(ingofwholeapples)isonlyTOSC(Figa),thenalmostalloftheantioxidantactivityinapplesmustbeduetophytochemicalsWetreatedacoloncancercellline,Caco,withextractsequivalentto,,,,,andmgmlapplesforhours(thetreatmenttimeformaximalresponse)Cellproliferationwasinhibitedinadosedependentmannerafterexposuretoappleextractconcentrationsabovemgml(Figb):atmgml,inhibitionwasandforappleswithskinandforappleswithoutskin,respectivelyWealsotestedtheeffectofappleextractsontheproliferationofanothercancercellline,HepGhumanlivertumourcellsWefoundthatappleextractsatmgmlinhibitedtheproliferationofthesecellsaswell,byandforappleswithandwithoutskin,respectively(Figc)Theextractsofapplewithskincouldthussignificantly(ttest,P*)reducetumourcellproliferationcomparedwithextractsofappleswithoutskinNocytotoxicityoftheappleextractswasseenatanyoftheconcentrationstested(datanotshown)Wesuggestthatthisstronginhibitionoftumourcellproliferationinvitrocouldbeduetoapples’combinationofphytochemicals(phenolicacidsandflavonoids),asthesearenaturalantioxidantsIthasbeenproposedthattheconsumptionofwholefruitsmayprovidetheantioxidantbalanceneededtoquenchreactiveoxygenspecieswhichhavebeenimplicatedintumorigenesisPhytochemicalsinapplesotherthanascorbicacidseemsignificantlytoenhancetheirantioxidantpropertiesandtheircapacitytoinhibittheproliferationoftumourcellsinvitrobriefcommunicationsMeantotalantioxidantactivityCellproliferation()Cellproliferation()Appleextracts(mgml–)Appleextracts(mgml–)abcVitaminCfrom(AS)(AS)(A–S)FigureAntioxidantactivityofapplesandtheireffectontumourcellproliferationinvitroa,Meantotalantioxidantactivityexpressedbytotaloxyradicalscavengingcapacity(TOSCmmolvitaminCequivalentsperg)assayforgapplewithskin(AS),andforapplewithoutskin(AS)b,InhibitionofproliferationofCacocolontumourcellsbyextractsofapplewithandwithoutskinc,InhibitionofproliferationofHepGlivertumourcellsControlsampleswereassayedasappleextracts,buttheycontainedonlyvitaminCatthesameconcentrationthatexistsinapples(mgg)CellproliferationwasdeterminedbyusingtheMTSassayBluecircles,applewithskinyellowcircles,applewithoutskinorangetriangles,controlextractsBotanyConstraintstogrowthofborealforestsUnderstandinghowthegrowthoftreesathighlatitudesinborealforestiscontrolledisimportantforprojectionsofglobalcarbonsequestrationandtimberproductioninrelationtoclimatechangeIsstemgrowthofborealforesttreesconstrainedbythelengthofthegrowingseasonwhenstemcambialcellsdivide,orbythelengthoftheperiodwhenresourcescanbecapturedInbothcases,thetimingofthethawinthespringiscritical:neithercambialcelldivisionnoruptakeofnutrientsandcarbondioxidecanoccurwhilethesoilisfrozenHereweargue,onthebasisoflongtermobservationsmadeinnorthernSaskatchewanandSweden,thatthetimebetweenthespringthawandtheautumnfreezedeterminestheamountofannualtreegrowth,mainlythroughtemperatureeffectsoncarbondioxideuptakeinspring©MacmillanMagazinesLtd

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结论:吃水果

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