General Ecology (BIO 160) | Scientific Literature Scientific Literature & Hypothesis Testing Overview Inordertoadvancescientificunderstanding,scientistsmustcommunicatetheresultsof researchthattestsoriginalhypotheses.Oneofthemostimportantwaysscientists communicatetheresultsoftheirresearchisbypublishingscientificpapers.Thissemesteryou willbeconductingascientificresearchprojectandtestinganecologicallyrelevanthypothesis. Youwillalsocommunicatetheresultsofyourresearchintheformofascientificresearch paper.Consequently,youneedtobecomefamiliarwiththepurpose,organization,format,and strategyofcitingscientificliterature,aswellashowtocraftanecologicalhypothesis. The Purpose of Researching and Citing Scientific Literature Whygotothetroubleofresearchingscientificarticles?Thisisagreatquestion!Itcantake alotoftimetofindtherightarticles–andonceyou’vefoundthemyouactuallyhavetoread andunderstandthem!Perhapsthemostimportantreasonforconductingliteratureresearchis tobecomeinformedaboutwhatisknownandwhatisnotknownabouttheparticularscientific problemorquestioninwhichyouareinterested.Considerthis.Itwouldbeashame–notto mentionaterriblewasteoftime–ifyouweretoconductanentireresearchstudyona questionthathadalreadybeenansweredbyanotherscientistwhohadpublishedtheresultsof theirstudyjustthepreviousyear?Likewise,itwouldbeunfortunateifyouweretodesigna studyusingwhatyouthoughtwasanappropriatemethodologicalapproach,onlytofindout laterthroughaliteraturesearchthatthetechniqueyouhadusedwasdiscreditedanda superiormethodhadbeendevelopedbysomeoneelse.Ithinkyougettheidea! Whycitescientificarticlesinaresearchpaper?Thereareanumberofimportantreasons, butherearesomeofthemainones.Firstandforemost,citingscientificliteratureinapaper appropriatelyacknowledgestheoriginalsourceoftheinformationorideasinyourpaperthat you’vegatheredfromotherresearchersinthefield.Thesecondreasontociteliteratureisto placeyourstudyinthepropertheoreticalandempiricalcontextanddefendtheimportanceof theresearch.Inotherwords,youwanttocouchyourstudyintermsofwhatotherrelated researchhasbeendoneandusethatliteraturetosupporttheimportanceoftheworkandthe needfortestingyourspecifichypothesis.Asmentionedabove,thisisdoneintheIntroduction sectionofthepaper.Ifyou’regoingtotestahypothesis,youcertainlywanttoknowwhether someoneelsehasalreadytestedit.Orifthehypothesishasbeentested,thatit’sbeentested onadifferentorganism,setoforganisms,orinadifferentecologicalsystem.Thethirdreason, whichisrelatedtothesecond,istosupportyourhypothesis.Thatis,youwanttociteexisting scientificliteraturetoillustratewhatweknowaboutaproblemorquestionbeingaddressed andwhat’snotknown.It’swhat’snotknownthatmakesthecaseforandsupportsthetesting ofyourparticularhypothesis.Inotherwords,agoodhypothesisisnewandborneoutofa well-researchedliterature. Dr. Jim Baxter | 1 General Ecology (BIO 160) | Scientific Literature Anotherreasontocitescientificliteratureistosupportthemethodsyou’vechosentouse inyourstudy.Asmentionedabove,it’simportanttouseresearchmethodsthathavebeen provenbyotherstowork;citingthesemethodsprovidesthereaderwiththeinformation necessarytoevaluatethevalidityandcredibilityofthestudy’smethodologicalapproach. Finally,youcitescientificliteratureinordertocomparetheresultsofyourstudytothoseof others.ThisisdoneintheDiscussionsectionofthepaperandistremendouslyimportant becauseitallowsthereadertoproperlyevaluatetheimportanceofthestudyandthedegree towhichtheresultsofyourresearchareconsistentorinconsistentwithotherstudies. Anatomy of a Scientific Paper Thereareessentiallytwotypesofpublishedscientificliterature:primaryandsecondary. Scientificpapersthatreporttheresultsoforiginalresearcharereferredtoasprimary literature.Becausetheyreportoriginalresults,primaryliteraturepapersareorganizedina veryspecificway.Namely,theyincludeanintroduction,methods,results,anddiscussion, followedbyaliteraturecitedsection.Bycontrast,secondaryliterature(orasecondarysource) summarizes,reviews,orinterpretsscientificinformationthatwasoriginallyreportedelsewhere asprimaryliterature.Thisliteraturecanbeintendedforotherscientists(i.e.,areviewarticle)or forthegeneralpublic,andincludesreviews,textbooks,collections,magazinearticles, encyclopedias,handbooks,etc.Secondaryliteraturecanbedistinguishedfromprimary literaturebecauseitdoesnotcontainoriginalmethodsorresults. Primaryliteraturesourcesarevirtuallyallpeer-reviewed.Thatis,theyarereviewedand evaluatedbyexpertsinthefieldpriortopublication.Onlystudiesthatpassthisrigorouslevel ofscrutinyarepublishedasprimaryliterature.Secondaryliteratureisoftenbutnotalways peer-reviewed. Thebasicorganizationofaprimaryliteraturearticleincludesatitleandlistingofthe authorsandtheiraffiliations,followedbyanabstract,theintroduction,methods,results,and discussionsections,andlastlyaliteraturecitedsection.Thesebasicelementsaredescribed below. TheTitleprovidesaclearandconcisedescriptionofthestudyandincludeskeywordsthat allowotherstoeffectivelyfindthearticlethroughsearchengines.Afterthetitle,theauthorsof thestudyandtheirinstitutionalaffiliationsarelisted.Itisimportanttonotethattheorderof theauthorsisdeterminednotalphabeticallybutbywhocontributedmosttotheresearch and/orwritingthepaper.Consequently,thefirstauthorlistedistheprimaryauthorandisthe onewhoreceivesmostcreditforthework;subsequentauthorscontributedtotheworkbuta lesserdegreethanthefirstauthor.Theauthorsusuallyagreeuponauthororderbeforethe paperiswritten.Forthisreason,authorordershouldneverbechangedwhencitingascientific paper. TheAbstractisasummaryofthepaper.Itincludesabrief(typically300wordsorless) descriptionoftheproblemandhypothesis(es)beingaddressed,themethods,theprimary results,andthemainconclusionsofthestudy. Dr. Jim Baxter | 2 General Ecology (BIO 160) | Scientific Literature TheIntroductionorientsthereadertothespecificproblembeingaddressed.Itmust provideawell-informedandresearchedbackgroundonthespecificproblemandtheoretical contextforthestudy.Theintroductionpresentswhatisknownandwhatisnotknowninthe scientificliteratureabouttheproblembeingaddressedandleadsthereaderlogicallytothe study’shypothesis(es),whichis/arestatedattheendoftheintroduction.Consequently,the Introductionmustincludeproperlycitedreferencestotherelevantscientificliterature.Atthe endoftheIntroduction,thehypothesesoftheresearchareconciselystatedalongwiththe approachtakentotestthem. Inanecologicalstudy,theMethodssectiondescribesthestudysite,theorganism(s) studied,theexperimentaldesign,andhowthedatawereanalyzed.Itprovidesabriefbut concisedescriptionofallmethodsusedintheresearch.Themethodssectionisnotoverly detailed,butdetailedenoughsothatsomeoneelsecouldconductthesamebasicexperiment. TheResultssectiondescribesasummaryofthefindingsoftheresearchwithout interpretation.Itprovidesasummaryofthegeneralpatterns,trends,andvariationinthedata intheformoftext,tablesandfigures.Thetextdescribestheresultspresentedinalltablesand figuresinthepaper.Tablesareusedtopresentmanynumericalvalues(ortosummarizeor emphasizedescriptivematerial),whereasfigures(e.g.,agraph)areusedtoillustratean importantcomparison,pattern,trend,orrelationship. TheDiscussionsectioniswheretheresultsofthestudyareinterpretedandconclusions formulated.Inotherwords,thissectionexplainswhythespecificresultsofthestudywere obtainedand,bycitingsupportingliterature,howthefindingscomparewithpreviousstudies donebyresearchersexaminingsimilarquestionsorspecies.Italsoaddressesanyshortcomings oftheresearchandexploresthestudy’sbroaderimplications.TheDiscussiongenerallyends withashortsummaryorconclusionofthestudy’soverallimportance. TheLiteratureCitedsectionlistsonlythereferencesthatwerecitedinthebodyofthe paper;thatis,itisNOTabibliography(whichincludesallsourceswhetherornottheyare actuallycitedinthepaper).Citationsreferencedinthetextofthepaperarelistedattheendof thepaper.Althoughthecitationsaregenerallylistedinalphabeticalorderbyfirstauthor’slast name,somejournalslistthepapersnumericallyintheLiteratureCitedsectionintheorderthey werecitedinthetext.Inthiscoursewewilllistthemalphabetically. How to Find the Right Articles Findingtherightprimaryliteraturearticlesneednotbeamonumentaltaskorafrustrating one.Infact,giventheavailabilityandpowerofonlineelectronicdatabases,it’seasierthanit’s everbeentoidentifyandacquireaprimaryliteraturearticlethatpertainstoaspecificresearch problemorquestion.Withafewkeytipsonhowtoconductanonlinesearch–plusalittle practice–you’llfindthatit’sactuallyquitesimple. Asinanysearch,thefirst–andmostimportant–stepistoknowwhatyou’relookingfor. So,beforeyouembarkonasearchforaprimaryliteraturearticle,takesometimetonarrow Dr. Jim Baxter | 3 General Ecology (BIO 160) | Scientific Literature yourfocusandcomeupwithafewkeytermsthatyoucanusetoconductyoursearch.Thiswill makethejoboffindingresearchpapersthatarerelevanttotheproblemorquestionyouare addressingaloteasier.Asaruleofthumb,startwiththemostspecifictermsfirstandthenget moregeneralifyoucan’tfindappropriatearticles.Forexample,ifyoustartbytryingtofind papersonaparticularanimalspeciesalongtheAmericanRiverinSacramentoCounty, California,youmaynotfindanypublishedpapersbecausethetopicandlocationaretoo specific.Inthiscase,youwillneedtosearchmorebroadly–say,forexample,anything publishedatallontheparticularanimalspeciesyou’relookingfor.Inthislabyou’lllearnabout SacState’sliteraturesearchdatabasesfromoneofSacState’ssciencelibrarians,aswellasa fewvaluablestrategiesandtricksofthetradetofindthebestarticlesforyourproject. Citing Scientific Literature Acrossthevastnumberofpublishersofprimaryliteraturearticles,eachusesadifferent formattocitescientificliterature.Inthiscourse,wewilluseacitationformatusedinthe journalEcology.NotonlywillyouuseEcologyformatinthislabexercise,butyouwillalsouseit inyourfinalresearchpaper.AdetaileddescriptionofEcologyformatcanbefoundontheCSUS library’swebsite:http://csus.libguides.com/ecology. Inascientificarticle,citationsarefoundintwoplaces:inthetextitself,andattheendof thearticle.Eacharticlereferredtointhetextislistedasafullcitationattheendofthepaper. Acitationthatoccursinthetextisreferredtoasanin-textcitation;thecorrespondingfull citationincludesalloftheinformationnecessarytolocatethecitedreferenceandislistedat theendofthepaperintheLiteratureCitedsection.Thiswayoforganizingcitationsinan articleallowsthereadertoseeinthetextthattheauthoriscitingaspecificsourceforthe informationbeingpresentedandisgivingcredittothatsource.Italsoallowsthereadertofind thearticlebeingcitedbyprovidingthecorrespondingfullcitationattheendofthepaper.Note thattheLiteratureCitedsectionisNOTabibliography;itonlyincludesalistofthereferences citedinthepaper. Tomaintainthefocusandflowofthetext,aswellasconservespace,anin-textcitationis writteninashorthandstylethatincludesonlytheminimumauthorinformationandyearof publication.Forapaperwithonlyoneauthor,thein-textcitationinEcologyformatissimply theauthor’slastnamefollowedbytheyearofpublication.Fortwoauthors,thein-textcitation wouldincludethelastnamesofbothauthorsseparatedby“and,”andfollowedbytheyearof publication.Ifthepaperhasmorethanthreeauthors,thentheLatin“etal.”(meaning“and others”)iswrittenafterthefirstauthor’slastname;thecitationisthecompletedbyaddingthe yearofpublicationattheend. Eachin-textcitationmusthaveacorrespondingfullcitationattheendofthepaperinthe LiteratureCitedsection.Fullcitationsaregenerallylistedinalphabeticalorderbyfirstauthor’s lastname.However,somejournalscitepapersusingnumbersandlistthefullcitationsatthe endofthepapernumericallyintheordertheywerecitedinthearticle.Despiteformatting differences,allarticlescitedinthetextarelistedattheendofthepaper;sourcesthatwere usedforreferencebutnotactuallycitedinthetextarenotlistedattheendofthepaper. Dr. Jim Baxter | 4 General Ecology (BIO 160) | Scientific Literature Hypothesis Testing Likeallscientists,ecologistsattempttounderstandthenaturalworldthroughthe systematicandrigorousprocessofscience.Scienceisnotjustabodyoffactstobememorized. Itisaprocessthatisusedtolearnaboutnature.Learninghowtodoscience(theprocess)is justasimportant,ifnotmoreso,aslearningfacts(theproductsofscience).Althoughthis processhasbeencommonlyreferredtoasthe"scientificmethod,"intruththereisnosingle scientificmethod;indeed,itisaprocessthatvariesfromonedisciplinetoanotherandcantake manydifferentforms. Inmostcases,however,theprocessofscientificinquirybeginswithanobservationof somethingthatisinterestingorunexpected.Inecology,ourobservationsareoftenpatternsin naturethatintrigueusandforwhichweseekanexplanation.Patternsinecologycantake manyforms.Forexample,interestingecologicalpatternsmightincludecertainforaging behaviorsofsmallmammalsinrelationtopredationrisk,thedistributionofindividualsor speciescorrespondingtodifferenthabitatconditions,orglobalpatternsofproductivitythatare coincidenttolatitudinalvariationintemperatureandprecipitation. Basedonsuchobservations,incombinationwithwhatisalreadyknownfromthepublished literature,wecandevelopplausibleexplanationsthatcanbetestedwithexperimentation.This sequence,fromobservationtohypothesistoexperimentationandinterpretationdescribesthe scientificmethod,whichgenerallyinvolvesthefollowingsequence: Observation Anobservationinscienceconsistsofobtainingknowledgeoftheoutsideworldthroughour senses,orrecordingsuchinformationusingscientifictoolsandinstruments.Inecology,the kindsofobservationsecologistsmaketellussomethingaboutthewaythenaturalworldworks. Notethatthisdiffersfromdatarecordedduringanexperiment,whichcanalsobecalledan experimentalobservation.Here’sanexampleofanecologicalobservation:Twoplantspecies, AandB,areneverfoundinthesamelocation,eventhoughtheyseemtothriveinsimilar habitats. Hypothesis Onceanobservationismade,aproposedexplanationorpredictionfortheobserved phenomenonismade;thisisahypothesis.Ahypothesisisneverstatedasaquestion. Althoughaquestionoftencomesfirst,forittobeahypothesisthequestionmustbeconverted intoasinglestatement.Ahypothesismustalsobetestable.Thatis,theremustbeasetof observationsormeasurementsthatcanbemadetodeterminewhetherornotthehypothesisis supported.Italsomustbefalsifiable.Inotherwords,itmustbepossibletoshowthatthe hypothesisisfalse.Ahypothesismustalsoincludebothanindependentanddependent variable.Theindependentvariableisthefactoryou’remanipulating.Thedependentvariable iswhatyou’remeasuring(i.e.,theresponsevariable)andiswhatwillactuallybemeasuredin responsetotheindependentvariable.Inshort,independentvariablesanswerthequestion "WhatdoIchange?"anddependentvariablesanswerthequestion"WhatdoIobserve?"For example: Dr. Jim Baxter | 5 General Ecology (BIO 160) | Scientific Literature Example1:PlantspeciesAwillbemoreabundantafterafirethanplantspeciesB. Example2:Algalbiomasswillbegreaterinlakesthatreceivehighamountsofnutrientrunoffthaninlakesthatreceivelownutrientrun-off. Ineachhypothesisabove,canyouidentifythedependentvariable?Theindependent variable? Notethateveryhypothesisthatpredictsachangeinadependentvariableinresponsetoan independentvariablehasanimpliednullhypothesis.Anullhypothesissimplypredictsthat therewillbeno(i.e.,null)differenceinthevalueofthedependentvariablewithrespecttothe independentvariable.Intheexamplesabove,thenullhypotheseswouldbethatthereisno differenceinabundanceofplantspeciesAandB(Example1)andnodifferenceinalgalbiomass betweenlakes(Example2).Althoughithasvalueasastatisticalhypothesis,thenullhypothesis isgenerallynotstatedexplicitlyinaresearchstudy. Anyonecancomeupwithaplausiblehypothesis.Butwhatdistinguishesthescientistfrom theamateuristhethirdstep:arigorousandcontrolledtestofthehypothesis.Oftenthis involvesanexperiment,althoughcomparativeanddescriptivestudiesarealsocommon. Experiment Anexperimentisanimportanttoolthatscientistsusetotesthypotheses.Themostrobust formofexperimentisthemanipulativeexperiment,inwhichtheexperimentermanipulatesthe conditionsinacertainsetofexperimentalunits.Anexperimentalunitisthebasicunitbeing measuredinanexperiment.Forexample,anindividualplantmightbetheexperimentalunit usedtotesttheeffectofsoilnutrientsonplantgrowthbecausethescientistwouldmeasure thegrowthoftheentireplant–saybiomassorheightofthewholeplant.Becausetheplantis theunitbeingmeasuredintheexperiment,wesaythatitistheexperimentalunit. Whenascientistmanipulatesasetofexperimentalunits(e.g.,byaddingnutrientstoaset ofplants),themanipulationsarereferredtoastreatments(orfactors).Therearetwotypesof treatments:experimentalandcontroltreatments.Anexperimentaltreatmentinvolvesadirect manipulationbytheexperimenter.Acontroltreatmentisonethatisleftun-manipulated.By comparingexperimentaltocontroltreatments–allotherthingsbeingequal–scientistscan unambiguouslyattributeanyeffectsofthetreatmenttothespecificfactorthatwas manipulated. Dr. Jim Baxter | 6 General Ecology (BIO 160) | Scientific Literature Pre-lab Name: ________________________ DUEATBEGINNINGOFLAB Toreceivecredityoumustturninthisanswersheet. WatchtheEcologyFormattutorialat:http://csus.libguides.com/bio160tutorial Takethequizattheendofthetutorial.Printouttheresultofyourquizandattachithere. Answerquestions1-6basedontheresearcharticle:BaxterandParker(1999).Alinktothepdfcopyof thisarticleispostedonthecoursewebsiteontheActivities/Assignmentspage. 1. Inwhichsectionofthepaperdotheauthorssummarizethefindingsoftheirstudywithout interpretationordrawingconclusions? 2. WhatisthepurposeoftheDiscussionsection?IsitnecessarytoincludecitationsintheDiscussion section?Whyorwhynot? 3. Whatwasonehypothesistestedinthestudy?Inwhichsectionofthepaperisitstated? 4. Wherewasthestudyconductedandhowwastheplantcommunitysampled?Whichsectionofthe paperdescribesthis? 5. Whatwasthemajorconclusionofthisstudy?Inwhichsectionwasthisstated? 6. IntheLiteratureCitedsectionthereisapapercitedbyWilliams,K.asthefirstauthor.Writethis citationasan"in-text"citationin‘Ecology’format. Dr. Jim Baxter | 7 General Ecology (BIO 160) | Scientific Literature Lab Activity: Part I – Anatomy of a Scientific Paper (4 pts.) Wewillreviewyouranswerstothepre-labquestionsontheBaxterandParker(1990)article (referencedabove).Eachgroupwillbeassignedaquestionandaskedtoreportoutontheir answer.Note:Besuretobringacopyofthearticlewithyou. Lab Activity: Part II – Writing a Good Hypothesis (6 pts.) Thesecondpartofthelabisagroup-shareexercise.Thegoaloftheexerciseisto: 1. Learnwhatmakesa"good"hypothesis, 2. Gainpracticewritingagoodhypothesis,and 3. Developapreliminaryhypothesisforyourresearchtopic Whatmakesa"good"hypothesis? Agoodhypothesis: 1. Isaconcisesinglesentencestatementthatputsforthaproposedexplanationforan eventorobservation.Itisnotaquestion.Aquestionmaycomefirst–andoftendoes– butforittobeahypothesisthequestionmustbeconvertedintoasinglestatement. 2. Istestable.Thatis,theremustbeasetofobservationsthatcanbemadetodetermine whetherornotthehypothesisissupported. 3. Isfalsifiable.Inotherwords,it'sexperimentallyfalsifiableandclearlyisolatescauseand effect(i.e.,howonethingwillaffecttheother). 4. Includesanindependentvariable(thefactoryou’remanipulating)andadependent variable(whatyou’remeasuring).Ifyouknowenoughtopredictthedirectionofa responseorrelationship,usewordslike“increase”and“decrease”toindicatethat. TheActivity Youwillworkwithyourgrouptodevelopapreliminaryhypothesisusingtheresearchtopicyou receivedlastweek.Onceyou’vedraftedahypothesisthatyouallagreeto,yourgroupwill shareitshypothesiswithanothergroup.Thatgroupwillreviewit,reviseitifneededandshare theircommentswithyou.Yourgroupwillalsohavetheopportunitytoreview,reviseandshare itsassessmentofanothergroup'shypothesis.Beforeyoubegin,besuretoreviewthecriteria aboveforcraftingagoodhypothesis. Beforeyougiveyourhypothesistotheothergroupforevaluation,checktomakesurethatit meetsallofthecriteriaaboveandthateveryoneinyourgroupishappywithit. Dr. Jim Baxter | 8 General Ecology (BIO 160) | Scientific Literature Lab Activity: Part III – Article Search Strategies (8 pts.) Inthispartofthelab,wewilllearnhowtousetheuniversity’sonlineDatabaseandArticle Searchingsitetolocaterelevantprimaryliteratureforyourresearchproject.Ioroneofthe ScienceLibrarianswillsharetipsondesigningandconductingasuccessfulsearch,howto retrieverelevantarticles,andhowtoproperlycitepapersinEcologyformat. Assignment Yourassignmentistolocateseveralpeer-reviewedprimaryliteraturearticlesonyourresearch projecttopicthatwillhelpyoudevelopandrefineyourhypothesis.Foroneofthesepapers, youmustwritethecitationinEcologyformatbelow.Toreceivecredit,Iwillcomearoundand checkyourcitationforcorrectformatting. WriteyourcitationinEcologyformatbelow: Dr. Jim Baxter | 9 General Ecology (BIO 160) | Scientific Literature Post-Lab Assignment (12 pts.) DUENEXTLAB Name: _______________________ Toreceivecreditforthepost-labyoumustturninthisanswersheet. 1. Howcanyoutellwhetherornotanarticleisaprimaryliteraturearticle? 2. Findoneprimaryliteraturearticlethatisrelevanttoyourgroupresearchtopicandciteitbelowin Ecologyformat. 3. Findanotherprimaryliteraturearticleonyourresearchtopicthatfocusesspecificallyonthe environmentalfactorsthatinfluencetheabundance,diversityorbehaviorofthespeciesyouwillbe workingwith.Citethepaperasanin-textcitationinEcologyformat. 4. Whatisthepurposeofcitingliterature?Inwhichtwotextsectionsofaprimaryliteraturepaperisit mostcommon(andnecessary)tocitethescientificliterature? 5. Whencitingascientificarticlewithmultipleauthors,doyouchangetheorderofauthors?Explain whyorwhynot. 6. Writeapreliminarydraftofyourgroup’sresearchhypothesisbelow.Giventhishypothesis,whatdo youthinkwouldbeanappropriateexperimentalunit? Dr. Jim Baxter | 10 General Ecology (BIO 160) | Scientific Literature Learning Objectives 1. Understandandappropriatelyapply/usethefollowingterms: primaryliterature Discussion hypothesis secondaryliterature LiteratureCited nullhypothesis Title Ecologyformat independentvariable Abstract fullcitationformat dependentvariable Introduction in-textcitationformat experimentalunit Methods scientificmethod treatment Results observation 2. Beabletoexplainthedifferencebetweenprimaryandsecondaryliterature. 3. Beabletoexplaintheorganizationofascientificjournalarticle,plusthepurposeofits differentsections. 4. Beabletoappropriatelyciteprimaryliteraturearticlesasfullandin-textcitationsinthe formatusedbythejournalEcology. 5. Developskillandself-confidenceconductingsearchesforprimaryscientificliterature articlesusingthelibrary’sonlineresources. 6. Beabletoformulateatestable,falsifiableandecologicallyrelevanthypothesis. Dr. Jim Baxter | 11
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