简介：ThetropicalPacifichasbeguntoexperienceanewtypeofElNio,whichhasoccurredparticularlyfrequentlyduringthelastdecade,referredtoasthecentralPacific(CP)ElNio.Variouscoupledmodelswithdifferentdegreesofcomplexityhavebeenusedtomakereal-timeElNiopredictions,buthighuncertaintystillexistsintheirforecasts.ItremainsunknownastohowmuchofthisuncertaintyisspecificallyrelatedtothenewCP-typeElNioandhowmuchiscommontoboththistypeandtheconventionalEasternPacific(EP)-typeElNio.Inthisstudy,thedeterministicperformanceofanElNio–SouthernOscillation(ENSO)ensemblepredictionsystemisexaminedforthetwotypesofElNio.EnsemblehindcastsarerunforthenineEPElNioeventsandtwelveCPElNioeventsthathaveoccurredsince1950.Theresultsshowthat(1)theskillscoresfortheEPeventsaresignificantlybetterthanthosefortheCPevents,atallleadtimes;(2)thesystematicforecastbiasescomemostlyfromthepredictionoftheCPevents;and(3)thesystematicerrorischaracterizedbyanoverlywarmeasternPacificduringthespringseason,indicatingastrongerspringpredictionbarrierfortheCPElNio.Furtherimprovementstocoupledatmosphere–oceanmodelsintermsofCPElNiopredictionshouldberecognizedasakeyandhigh-prioritytaskfortheclimatepredictioncommunity.

简介：Transposableelements(TEs)aremobilegeneticentitiesubiquitouslydistributedinnearlyallgenomes.HighfrequencyofcodonsendinginA/TinTEshasbeenpreviouslyobservedinsomespecies.Inthisstudy,thebiasesinnucleotidecompositionandcodonusageofTEtransposasesandhostnucleargeneswereinvestigatedintheAT-richgenomeofArabidopsisthalianaandtheGC-richgenomeofOryzasativa.CodonsendinginA/TaremorefrequentlyusedbyTEscomparedwiththeirhostnucleargenes.AremarkablepositivecorrelationbetweenhighlyexpressednucleargenesandC/G-endingcodonsweredetectedinO.sativa(r=0.944and0.839,respectively,P<0.0001)butnotinA.thaliana,indicatingacloseassociationbetweentheGCcontentandgeneexpressionlevelinmonocotspecies.Inbothspecies,TEcodonusagebiasesaresimilartothatofweaklyexpressedgenes.TheexpressionandactivityofTEsmaybestrictlycontrolledinplantgenomes.MutationbiasandselectionpressurehavesimultaneouslyactedontheTEevolutioninA.thalianaandO.sativa.TheconsistentlyobservedbiasesofnucleotidecompositionandcodonusageofTEsmayalsoprovideausefulcluetoaccuratelydetectTEsequencesindifferentspecies.