60secondscience60秒科学听力原文5.docx

60secondscience60秒科学听力原文5.docx

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60secondscience60秒科学听力原文5

ThievingBirdApesItsVictims

Thefork-taileddrongocanmimicthealarmcallsofdozensofotherspeciesofanimals,includingnonbirds,todrivethemoffandstealtheirfood.CynthiaGraberreports

May5,2014|ByCynthiaGraber

[Musicplays]NeilYoung?

No,that’sJimmyFallonimitatingNeilYoung.Doingimpressionscanbeavaluableskill.Infact,abirdcalledthefork-taileddrongomakesagoodlivingatit,initshomeinAfrica’sKalahariDesert.Thedrongocanmimicthealarmcallsofanotherbird.Whenthatbirdfleestheimagineddanger,thedrongoswoopsintotakeanyfoodleftbehind.

Ananimalmimickinganotheranimalisnotrare.Andtargetscangrowwisetothetrick.Thedrongo’srealtalentisthatitcandothewarningcallsofmultiplespecies.[Musicplays]LikehowJimmyFalloncanalsodoVanMorrison.

Researchersfollowed64wilddrongosfornearly850hours.Drongosdosoundaccuratealarmsinresponsetoactualpredators.Butwhentheyspotatemptingmealinanotherbird’spossession,theysendoutafalsealarm.Here’sonemimickingapiedbabbler.[Drongocall]

Anotheraglossystarling’salarm.[Drongocall]

Andhere’sadrongomimickingameerkatalarm.[Drongocall]

Theresearcherssawalmost700drongoattemptstostealfood.Theyestimatethatanyonedrongomightknowupto32differentspecies’alarms.Andstolenfoodaccountedfornearlyaquarteroftheirdailyintake.ThestudyisinthejournalScience.[TomP.Flower,MatthewGribbleandAmandaR.Ridley,DeceptionbyFlexibleAlarmMimicryinanAfricanBird]

Foolbirdsonce?

Shameonthem.Foolbirdsmultipletimes?

Successforthefork-taileddrongo.

—CynthiaGraber

[Theabovetextisatranscriptofthispodcast.]

SurgeonsTryColdCuttingforCriticallyInjured

Aclinicaltrialtestswhetherinducedhypothermiacanallowsurgeonstosavecriticallywoundedpatientswhowouldnotsurvivesurgeryatnormaltemperatures.ErikaBerasreports

May6,2014|ByErikaBeras

Onrareoccasions,aswimmercansurviveanear-drowningbecausecoldwaterhasprotectedtheirbrains—eveniftheyweresubmergedforuptoanhour.Nowaclinicaltrialistestingwhetherextremecoldcansavecriticallyinjuredgunshotandknifewoundpatients.

It’scalledtheEmergencyPreservationandResuscitationforCardiacArrestfromTraumaStudy.LeadSurgeonSamTishermanattheUniversityofPittsburghMedicalCenterexplainsthatpatientsarenotdeclareddead,but:

“They’dbeclose.They’reincardiacarrestandcertainlyifwecan’tgetapulsebackthey’dbedead.Butwe’renotwaitingtothepointwherethesurgeonswoulddeclarethemdead.We’retryingtodothisrightbeforethis,andfindthebestwindowofopportunitywhereourstandardofcarehasn’tworkedbutit’snottoolatetotrysomethingnew.”

Surgeonswillcoolthepatients’bodiesto50degreesbypumpingdozensoflitersofcoldsalineintotheheart.Thisinducedhypothermianearlyhaltsallactivityinthebodyandbrain.

Byfreezingpatients,thesurgeonswillalsofreezetime—givingthemtheopportunitytorepairwoundsawarmpatientwouldn’ttypicallysurvive.Shouldtheprocedureproveeffective,itcouldgiveanewmeaningtothephrase“coldcomfort.”

—ErikaBeras

[Theabovetextisatranscriptofthispodcast.]

LasersIDInsectsbyWingBeats

Usinglasersensingofinsectwingbeats,pluslocationandtimeofday,researchersreport99percentaccuracyidentifyingindividualsinagroupofsixinsectspecies.Afuturesurveillancesystemwouldbeofinteresttofarmersandinsect-bornediseasemonitors.CynthiaGraberreports

May7,2014|ByCynthiaGraber

Toafarmer,goodinsectspollinate.Andbadinsectsdecimate.Andthey’veoftenhadatoughtimeknowingwhichflyingcreatureswereinvadingtheircrops.Noweavesdroppingresearchersmightofferhelp.

For60years,scientistshavetriedtoidentifyinsectsbytheirwingsounds.Thechallengeincreaseswithdistance,windandothernoises.Soresearcherscreatedamonitorusinglasers.Whenaninsectcrossesthelaser,theshadowofthewingbeatsgetsrecordedandtranslatedintoanmp3.Here’safemaleaedesaegyptimosquito.Here’safemaleculexquinquefasciatus.

Theresearchersspentthreeyearsgatheringdatafromdozensofsensors.Theyhavetensofmillionsofdatapoints—morethanhadbeenpreviouslycollectedalltogether—fortheiralgorithms.Usingwingbeatspluslocationandtimeofday,they’veachievedupto99percentaccuracyidentifyingsixinsectspeciesthusfar.

TheresearchwillbepublishedintheJournalofInsectBehavior.[YanpingChen,EamonnKeoghetal,FlyingInsectClassificationWithInexpensiveSensors]

TheprototypewasmadeofLEGOs,a99-centlaserpointerandpartofaTVremote.Soresearcherssayasetupcouldbemanufacturedforlessthan$10.Itcouldidentifybothfarmpestsanddiseasecarriers.Whichcouldhelppeoplepicnicinpeace.

—CynthiaGraber

[Theabovetextisatranscriptofthispodcast.]

OenophilesConfirmFruityFlavorsFinishFirst

Wineresearchersfindthatfruityflavorstendtofinishquickestonthepalate,whereasoakyflavorslingerlonger--asaficionadoshavelongclaimed.ChristopherIntagliatareports

May12,2014|ByChristopherIntagliata

Theloreamongwineaficionadosisthatfruityflavorstendtofinishquickestonthepalate,whereasoakyflavorslingerlonger.

“Andthenwhenyougotothescientificliterature,youfindoutthatreallytherehaven'tbeenscientificstudiesdoneonit.”CarolynRoss,asensoryscientistatWashingtonStateUniversity.

Sheandhercolleaguesinvestigatedtheclaims.Theyidentifiedfourflavorcompoundscommoninwhitewine,whichgivefloral,fruity,mushroomyandoakynotes.Theythenstudiedthecompoundsinwhat’sknownasamodelwine:

“Meaningthatithadalcoholinit,ithadsomesugar,someacidinit,butitwasn'tactuallywine.”

Theyaddedthecompoundsoneatatimetotheirmodelwine,andaskedtrainedtasterstoclockhowlongittookflavorstofade.Fruitydidindeedfinishfirst—lastingaminuteandahalf.Theotherstook30secondslongertofade.Andevenwhenmixedwiththeotherflavors,fruitystillfinishedfirst—sothelorewasright.

ThestudyappearsinthejournalFoodQualityandPreference.[EmilyS.Goodsteinetal,Perceptionofflavorfinishinmodelwhitewine:

Atime-intensitystudy]

Asforhometasters?

“Payattentiontothefinish,perhapstimeit,ifthat'syourthing.”Itdoeshappentobeours.

—ChristopherIntagliata

[Theabovetextisatranscriptofthispodcast.]

HealthyLungMicrobesKeepMiceBreathingEasy

Likehumans,micestartlifewithsterilelungsthatsoongetcolonizedbymicrobes,whichappeartoprotectthelungtissuefromanasthmalikereactioninthepresenceofdustmites.CynthiaGraberreports

May14,2014|ByCynthiaGraber

Humancellsareoutnumberedten-to-onebythemicrobesthatthriveinandonus.Nowastudyfindsthatthetinyorganismslivinginourlungsmayprotectusfromasthma.

Anewborn’slungsstartoutsterileandthenbecomecolonizedbymicrobes.Toseehowlungmicrobesmightinfluencediseasesusceptibility,researchersstudiedmice,whichalsostartwithsterilelungsthatsoonhostmicrobes.

Inthefirsttwoweeksoflife,thesemicrobialcommunitiesshiftandproliferate.Sothescientistslookedatthreegroupsofmice:

babiesthreedaysold,15-day-oldmice,andtwo-montholdadults.Allwereexposedtodustmites,whichprovokeinflammation.

Thenewbornmicedevelopedinflamedlungs—similartoasthma.Buttheoldergroupsremainedmostlyinflammationfree,indicatingaprotectiverolefortheirlungmicrobes.

Theresearchersthenexposedoldermicewhoselungshadbeenkeptsteriletomites.Thesemicedidgetinflamedlungs.ThestudyisinthejournalNatureMedicine.[EvaS.Gollwitzeretal,LungmicrobiotapromotestolerancetoallergensinneonatesviaPD-L1]

Theresearcherssaythatearlylungcolonizationbyadiverse,protectivemicrobialcommunityappearscrucial.Theyhopetoextendthesestudiestohumaninfants—tobetterunderstandourlungmicrobes,andhelpkidsbreathingfreely.（AlsoseeDrugstoBeDerivedfromInsightsintoBody-DwellingBacteria）

—CynthiaGraber

[Theabovetextisatranscriptofthispodcast.]

[ScientificAmericanispartofNaturePublishingGroup.]

TwitterOpinionQuicklyStabilizes

Astudyofmillionsoftweetsfoundthatpublicopinionquicklysolidifies,evenwithoutanoverwhelmingconcensus.AllieWilkinsonreports

May15,2014|ByAllieWilkinson

Allrise,theTwittercourtofpublicopinionisnowinsession.

Andthenextcaseonthedocketwillreachaquickverdict.BecausepublicopinionsolidifiesrapidlyonTwitter.That’saccordingtoastudyinthejournalChaos.[FeiXiong andYunLiu,Opinionformationonsocialmedia:

Anempiricalapproach]

Researcherscollectedalmost6milliontweetsduringasix-monthperiod.Theysortedthetweetsforeitherpositiveornegativesentiments,thenfocusedonthreetopicsrelatedtoelectronics. 

Atfirstopinionsfluctuated,withonesidegainingaslightadvantage.Thisadvantagegrewgraduallyandthenquicklyleveledoff,leavingoneopinioninastableanddominantposition—butwithoutanoverwhelmingconsensus.

Andoncepublicopinionisestablished,itisunlikelytochange.OnlythosewhoseealargenumberofdissentingopinionsamongthepeopletheyfollowonTwitterwillreconsiderandexaminetheopposingviewpoint.

Theseresultsmayofferavaluablelessonforcompanies,candidatesandanyoneelseinthespotlight.Ifyouplantoswaythejury,besuretomakeyourcaseearly.Becauseoncepublicopinionstabilizes,thejuryi