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简介：由生命周期评价(LCA)的申请方法论，这份报纸估计生产的环境影响和在中国在电的车辆使用的拖拉马达的处理。结果证明拖拉马达生产和处理的全部的精力使用，标准排出物和温室气体(GHG)排出物是大约2,899，MJ，4.5，kg并且259.5，kg每分别地交通。在调整排出物之中，SOx排放由全部的质量评价第一，由公司，PM10，没有x，PM2.5，和不稳定的有机化合物(VOC)列在后面。为大多数精力消费和排出物的马达材料生产阶段报道，由集会阶段和end-of-life处理列在后面舞台。在这研究，环境表演分析为材料生产阶段被扩大到在第二等的材料和主要材料的使用之间的比较。用100%，第二等的材料与百分之百主要的材料的使用相比在GHG排出物在精力消费，在调整排出物的49.8%减小，和49.3%减小导致52.9%减小，这被发现。

简介：Physicalactivity(PA)isaneffectivemeansofcurbingtheprevalenceofchildobesity,andfundamentalskillsarehypothesizedtobeanimportantfactorthatdeterminesphysicallyactiveorinactivebehaviorinchildren.Researchevidencesuggeststhatadolescentsandyoungadultswithproficientmotorskillsinsport-relatedactivitiesaremorelikelytohaveaphysicallyactivelifestyle.1Becausephysically

简介：Theeffectsofexerciseondecision-makingperformancehavebeenstudiedusingawidevarietyofcognitivetasksandexerciseinterventions.Althoughthecurrentliteraturesupportsabeneficialinfluenceofacuteexerciseoncognitiveperformance,themechanismsunderlyingthisphenomenonhavenotyetbeenelucidated.Wereviewstudiesthatusedsingle-pulsetranscranialmagneticstimulation(TMS)toprobetheexcitabilityofmotorstructuresduringwhole-bodyexerciseandpresentaframeworktoaccountforthefacilitatingeffectsofacuteexerciseonmotorprocesses.Recentresultssuggestthat,evenintheabsenceoffatigue,theincreaseincorticospinalexcitabilityclassicallyreportedduringsubmaximalandexhaustingexercisesmaybeaccompaniedbyareductioninintracorticalinhibition.Weproposethatreducedintracorticalinhibitionelicitsanadaptivecentralmechanismthatcounteractstheprogressivereductioninmuscleresponsivenesscausedbyperipheralfatigue.Suchareductionwouldrenderthemotorcortexmoresensitivetoupstreaminfluences,thuscausingincreasedcorticospinalexcitability.Furthermore,reductionofintracorticalinhibitionmayaccountforthemoreefficientdescendingdriveandfortheimprovementofreactiontimeperformanceduringexercise.Theadaptivemodulationinintracorticalinhibitioncouldbeimplementedthroughageneralincreaseinreticularactivationthatwouldfurtheraccountforenhancedsensorysensitivity.

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简介：Purpose:Toexaminetheassociationsamongpreschoolersfundamentalmotorskills,screen-time,physicalactivity(PA),andsedentarybehavior(SB).Methods:Childrenages3-4yearswereenrolledinaprospectiveobservationaltrialofPA.TrainedassessorsconductedtheTestofGrossMotorDevelopment-3rdedition(TGMD-3),andtheMovementAssessmentBatteryforChildren-2ndedition,andparent-reportedchildscreen-timeandsociodemographicinformation.Childrenworeanaccelerometerfor7daystoexamineSBandtotalPA(TPA).TPAwasfurthercharacterizedasmoderateto-vigorousPA(MVPA)orvigorousPA(VPA).Mixedlinearmodelswerecalculated,controllingforage(forTGMD-3),sex,householdincome,andaccelerometerweartime(foraccelerometrymodels),withchildcarecenterasarandomeffect.Theprimaryanalysisreportedonthecross-sectionalbaselinedataof126childrenwithcompletefundamentalmotorskillandscreen-timedata;asubanalysisincluded88childrenwithcompleteaccelerometrydata.Results:Childrenwere3.4±0.5yearsofage(54%girls;46%white,42%AfricanAmerican,12%other).Atotalof48%livedinhouseholdsatorbelowthefederalpovertylevel.Childrenengagedin5.1±3.6h/dayofscreen-time.Children’sscreen-timewasinverselyrelatedtotheMovementAssessmentBatteryforChildren-2ndedition,manualdexterityskillspercentile(β(SE)=-1.7(0.8),p=0.049).Intheaccelerometrysubsample,childrenengagedin5.9±0.9h/dayofTPAofwhich1.7±0.6h/daywasMVPA.BoysengagedinmoreMVPAandVPAandlessSBcomparedwithgirls(allp<0.05).AhigherTGMD-3,totalscore(b(SE)=0.4(0.2),p=0.017)andlocomotorscore(β(SE)=0.7(0.3),p=0.018)wereassociatedwithmoreVPAbutnotwithTPAorMVPA.Screen-timeandtelevisioninthebedroomwerenotrelatedtoSB,TPA,MVPA,orVPA.Conclusion:Children’smotorskillswerepositivelyrelatedtoVPAbutinverselyrelatedtoscreen-time.Furtherinquiryintotheimplicationsofhighexposuretoscreen-timeinyoungchildr

简介：Technologicaladvanceshaveincreasedtheprevalenceofsedentarybehaviors,asphysicalinactivityhasbecomeoneoftheleadingriskfactorsofdeathworldwide;asituationthatburdensthehealthcaresystemwithpreventablehealthdisorders.1Increasedincidenceofdiseasedecreasethequalityoflife,evenamongchildren,becausediseasesthatformerlyonsetduringadulthoodarenowimpactingpeopleearlyintheirlives,aswellasattheendoftheirlives,"bycumulativedamageovertimeorbythebiologicalembeddingofadversitiesduringsensitivedevelopmentalperiods"(p.1).2

简介：Background:Acentralaimofphysicaleducationisthepromotionofbasicmotorcompetencies(inGerman:MotorischeBasiskompetenzen;MOBAK),whichareprerequisitesforchildren’sactiveparticipationinsportsculture.ThisarticleintroducestheMOBAK-1testinstrumentfor6-to8-year-oldchildrenanddeterminestheconstructvalidityofthistestinstrument.Inaddition,therelationshipbetweenMOBAKandmotorability(i.e.,strength)aswellasbodymassindex(BMI),sex,andageisinvestigated.Methods:Weanalyzeddataof923firstandsecondgraders(422girls,501boys,age=6.80±0.44years).Thechildren’sbasicmotorcompetencieswereassessedbytheMOBAK-1testinstrument.Besidesanalysesoffrequency,correlation,andvariance,3confirmatoryfactoranalyseswithcovariateswereperformed.Results:Wefound2MOBAKfactorsconsistingof4itemseach.Thefirstfactor,locomotion,includedtheitemsbalancing,rolling,jumping,andsidestepping;thesecondfactor,objectcontrol,includedtheitemsthrowing,catching,bouncing,anddribbling.Themotorabilitystrengthhadasignificantinfluenceonthefactorslocomotion(b=0.60)andobjectcontrol(b=0.50).Olderpupilsachievedbetterresultsthanyoungerpupilsonobjectcontrol(b=0.29).Boysperformedbetteronobjectcontrol(b=-0.44),whereasgirlsachievedbetterresultsinlocomotion(b=0.07).PupilswithahighBMIachievedlowerperformanceonlyonthefactorlocomotion(b=-0.28).Conclusion:TheMOBAK-1testinstrumentdevelopedforthisstudymeetspsychometricvaliditydemandsandissuitabletoevaluateeffectsofsportsandphysicaleducation.

简介：Purpose':Physicalactivity(PA)andfundamentalmotorskillsareimportantcomponentsofcurrentandfuturetrajectoriesofhealthinyoungchildren.Thisstudyexaminedtheeffectsofa5-weekmotorskillinterventiononpreschoolers,motorskillcompetenceandtheirPAbehaviorswhileparticipatinginthemotorskillinterventionoroutdoorfreeplay(recess).Methods'.Atotalof102preschoolersservedasparticipantsandwerepartofamotorskillinterventiongroup(n=64)oracontrol/outdoorfreeplaygroup(n=38).Children'smotorskillswereassessedbeforeandaftertheinterventionusingtheTestofGrossMotorDevelopment-3rdedition.PAduringthemotorskillinterventionandoutdoorfreeplaywasassessedusingaccelerometersbothimmediatelybeforethestart(baseline,Week0orWeek1)andend(late.Week5orWeek6)oftheintervention.Results:Allchildrensignificantlyimprovedtheirmotorskillsfrombaselinetolateassessment(p<0.05).Childreninthemotorskillinterventiondemonstratedgreaterratesofchange(p<0.001)andscoredhigheronallmotorskillsatthelateassessmentcomparedwiththecontrolgroup(p<0.001).Therewasnoeffectofgroup(controlvs.intervention),buttherewasasignificanteffectofsexonchildren'sPAduringoutdoorfreeplayatbaseline(p<0.05).Similarly,therewasnoeffectofgrouponPAduringdayswiththemovementprogram(interventionvs.outdoorfreeplay)ateithertimepoint,butboysweremoreactivethangirlsatthelateassessment(p<0.05).Last,childrenintheinterventionengagedinmorePAwhileparticipatingintheinterventiontowardtheendoftheinterventionthanatthebeginning.Conclusion'.The5-weekmotorskillinterventionwaseffectiveatimprovingpreschoolers,motorskillsandratesofchangeinmotorskillswerehigherforchildrenwhocompletedtheinterventioncomparedwithchildreninthecontrolgroup.PreschoolersintheinterventiondiddemonstratePAchangeswhileparticipatingintheintervention,

简介：Thehighprevalenceofchildhoodobesity,evidentgloballyinthepastdecade,ispartlyduetolowphysicalactivity(PA).1Obesityandlowcardiovascularfitnessinchildrenmayincreasetheriskofhypertensionandhypercholesterolemiaduringchildhoodandmaycontributetothedevelopmentofchronicdiseasesinadulthood,suchashypertensionanddiabetes.2ParticipatinginregularPAplaysasignificantroleinthepreventionofanddecreaseinchildhoodobesityandchronicdiseases,therebycontributingtothepreventionofchronicdiseaseslaterinadulthood.

简介：Background:Fewschoolsettingsofferopportunitiesforpreschoolchildrentoengageinstructuredphysicalactivity,andonlyafewstudieshavebeenconductedexaminingexergaming’seffectivenessonhealthoutcomesinthisagegroup.Thisstudy’spurpose,therefore,wastoexamineaschool-basedexergamingintervention’seffectonpreschoolchildren’sperceivedcompetence(PC),motorskillcompetence(MSC),andphysicalactivityversususualcare(recess),aswellastoexaminegenderdifferencesfortheseoutcomes.Methods:Atotalof65preschoolchildrenfrom2underservedurbanschoolswereassignedto1of2conditions,withtheschoolastheexperimentalunit:(1)usualcarerecessgroup(8weeksof100minofrecess/week(5days×20min))and(2)exergaminginterventiongroup(8weeksof100minofexergaming/week(5days×20min)atschool).AllchildrenunderwentidenticalassessmentsofPC,MSC,andmoderate-to-vigorousphysicalactivity(MVPA)atbaselineandattheendofthe8thweek.Results:AsignificantGroup×TimeeffectwasobservedforMVPA,F(1,52)=4.37,p=0.04,ηp^2=0.04,butnotforPC,F(1,52)=0.83,p=0.37,ηp^2=0.02,orMSC,F(1,52)=0.02,p=0.88,ηp^2=0.00.Specifically,theinterventionchildrendisplayedsignificantlygreaterincreasedMVPAafter8weeksthanthecomparisonchildren.Additionally,therewasasignificanttimeeffectforMSC,F(1,52)=15.61,p<0.01,ηp^=0.23,andgendereffectforMVPA,F(1,52)=5.06,p=0.02,ηp^2=0.09.Althoughallpreschoolers’MSCimprovedacrosstime,boysdemonstratedgreaterMVPAthangirlsatbothtimepoints.Conclusion:Exergamingshowedapositiveeffectinpromotingpreschoolchildren’sMVPAatschoolandhasthepotentialtoenhancePCandMSC.Moreresearchwithlargersamplesizesandlongerstudydurationsarewarranted.

简介：Background:Childrenspend70%oftheschooldaysittinginclass.Classroom-basedactivebreakscanbenefitchildren’sphysicalhealth,butifthebreaksarecognitivelydemanding(i.e.,combinephysicalexertionandmentalengagement),theymayalsoimprovefocusandcognitivefunctions.Teachersandstudentsplayacrucialroleinthesuccessfulimplementationofactivebreaks,andtheirperspectivesarecriticaltothefeasibilityofthesestrategies.Theaimofthisstudywastoassessthefeasibilityofimplementingacognitivelychallengingmotortaskasanactivebreakinmainstreamandspecialprimaryschools.Methods:Atotalof5teachersin2mainstreamschoolsand7teachersin1specialschool(attendedbychildrenwithneurodevelopmentaldisorders)attendeda20-mintrainingonhowtoimplementa4-mincognitivelychallengingactivebreak,beforeconductingafeasibilitytrial(twiceadayfor1week).Tounderstandindividualperceptions,one-on-onesemistructuredinterviewswereconductedbeforeandafterthetrialwithteachers,andfocusgroupinterviewswereconductedwithtypicallydevelopingchildrenafterthetrial.Questionswerebasedonapredefinedframeworkforfeasibilitystudies.Allinterviewswereaudiorecorded,transcribedandanalyzedinNVivo11usingaframeworkapproach.Atotalof12teachers(11females;7between20and34yearsold)and34children(16girls;9.3±1.7years,mean±SD)participatedintheinterviews.Results:Inmainstreamschools,teachersviewedthecognitivelychallengingmotortaskasappropriateandpotentiallybeneficialforchildren’shealthandfocus.Childrenreportedenjoyingtheactivebreaks.Teachersinspecialschoolsviewedthetaskascomplexandpotentiallyfrustratingforchildren.Inbothschooltypes,children’sdisruptivebehaviorandlackoftimewereseenasthemainpotentialbarrierstoimplementation.Theuseofmusic,videos,visualcards,andsupportstaffwerenotedaspotentialfacilitators.Conclusion:Thecognitivelychallen

简介：Neuromuscularactivityissuppressedduringmaximaleccentric（ECC）musclecontractioninuntrainedsubjectsowingtoattenuatedlevelsofcentralactivationandreducedspinalmotorneuron（MN）excitabilityindicatedbyreducedelectromyographysignalamplitude,diminishedevokedH-reflexresponses,increasedautogenicMNinhibition,anddecreasedexcitabilityindescendingcorticospinalmotorpathways.MaximumECCmuscleforcerecordedduringmaximalvoluntarycontractioncanbeincreasedbysuperimposedelectricalmusclestimulationonlyinuntrainedindividualsandnotintrainedstrengthathletes,indicatingthatthesuppressioninMNactivationismodifiablebyresistancetraining.Insupportofthisnotion,maximumECCmusclestrengthcanbeincreasedbyuseofheavy-loadresistancetrainingowingtoaremovedordiminishedsuppressioninneuromuscularactivity.Prolonged（weekstomonths）ofheavy-loadresistancetrainingresultsinincreasedH-reflexandV-waveresponsesduringmaximalECCmuscleactionsalongwithmarkedgainsinmaximalECCmusclestrength,indicatingincreasedexcitabilityofspinalMNs,decreasedpresynapticand/orpostsynapticMNinhibition,andelevateddescendingmotordrive.Notably,theuseofsupramaximalECCresistancetrainingcanleadtoselectivelyelevatedV-waveresponsesduringmaximalECCcontraction,demonstratingthatadaptivechangesinspinalcircuitryfunctionand/orgainsindescendingmotordrivecanbeachievedduringmaximalECCcontractioninresponsetoheavy-loadresistancetraining.

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简介：Purpose:Thepurposeofthisstudywastodeterminetheeffectsofacuteexerciseonmotorresponseinhibitionusingbothbehavioralandelectrophysiologicalapproaches.Methods:TheP3andN1event-relatedpotential(ERP)componentswererecordedwhileperformingastop-signaltaskin21collegestudentsfollowingamoderatelyintenseacuteexerciseboutfor30minandasedentarycontrolsessionthatinvolvedreading.Results:Acuteexerciseinducedashorterstopsignalresponsetime(SSRT)ascomparedtocontrol;however,thegoresponsetime(GoRT)remainedunchanged.InexaminingtheERPdata,acuteexerciseincreasedbothP3amplitudeandlatencybutdidnotaffecttheN1component.Conclusion:Acuteexercisehasaselectiveandbeneficialeffectoncognitivefunction,specificallyaffectingthemotorresponseinhibitionaspectofexecutivefunction.Furthermore,acuteexercisepredominatelyimpactslaterstagesofinformationprocessingduringmotorresponseinhibition,whichmayleadtoanincreaseinattentionalresourceallocationandconfertheabilitytosuccessfullywithholdaresponsetoachievemotorresponseinhibition.

简介：Background:Motorcompetenceandhealth-relatedfitnessareimportantcomponentsforthedevelopmentandmaintenanceofahealthylifestyleinchildren.Thisstudyexaminedcross-culturalperformancesonmotorcompetenceandhealth-relatedfitnessbetweenPortugueseandU.S.children.Methods:Portuguese(n=508;10.14±2.13years,mean±SD)andU.S.(n=710;9.48±1.62years)childrenperformedtestsofcardiorespiratoryfitness(ProgressiveAerobicCardiovascularEnduranceRun),upperbodystrength(handgrip),locomotorskillperformance(standinglongjump),andobjectprojectionskillperformance(throwingandkicking).PortugueseandU.S.childrenweredividedinto2agegroups(6à9and10à13years)fordataanalysispurposes.Atwoàfactoroneàwayanalysisofcovariance(ANOVA)wasconductedwiththeProgressiveAerobicCardiovascularEnduranceRun,handgrip,standinglongjumpscores,kicking,andthrowingspeed(km/h)asdependentvariables.Results:ResultsindicatedthatPortuguesechildren,irrespectiveofsex,presentedbetterperformancesinlocomotorandcardiorespiratoryperformance(standinglongjumpandProgressiveAerobicCardiovascularEnduranceRun)thanU.S.childreninbothagebands.U.S.childrenoutperformedPortuguesechildrenduringthrowingandhandgriptests.Kickingtestspresentedgenderdifferences:PortugueseboysandU.S.girlsoutperformedtheirinternationallymatchedcounterparts.Conclusion:Culturaldifferencesinphysicaleducationcurriculaandsportsparticipationmayimpactdifferencesinmotorcompetenceandfitnessdevelopmentinthesecountries.