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简介：<正>Background:Muscularstrengthcanbeconceptuallydeterminedbytwocomponents:muscleactivationandsize.Muscleactivationbythecentralnervoussystemcanbemeasuredbysurfaceelectromyography(sEMG).Muscularsizereflectstheamountofcontractileproteinwithinaskeletalmuscleandcanbeestimatedbyanthropometricmeasurements.Thepurposeofthisstudywastodeterminetherelativecontributionsofsizeparametersandmuscleactivationtothepredictionofmaximalvoluntaryisometricelbowflexionstrength.Methods:Aseriesofanthropometricmeasurementsweretakenfrom96participants.Torqueandroot-mean-square(RMS)ofthesEMGfromthebicepsbrachiiwereaveragedacrossthreemaximalvoluntaryisometriccontractions.AmultiplelinearregressionanalysiswasperformedbasedonaPearson’scorrelationmatrix.Results:Bodyweight(BW)accountedfor39.1%and27.3%inmalesandfemales,respectively,andwasthestrongestpredictorofstrengthformales.Forearmlength(L3)wasthestrongestpredictorofstrengthinfemales(partialR~2=0.391).Elbowcircumference(ELB)accountedforasignificant(p<0.05)amountofvarianceinmalesbutnotfemales.TheadditionofsEMGRMSasathirdvariableaccountedforanaverageof10.1%ofthevarianceexcludingtheequationofBWandL3infemales.ThestrongestpredictionequationincludedBW,L3,andELBaccountingfor55.6%and58.5%ofthevarianceinmalesandfemales,respectively.Conclusion:Anthropometricsprovideastrongpredictionequationfortheestimationofisometricelbowflexionstrength.Muscleactivation,asmeasuredbysEMGactivity,accountedforasignificant(p<0.05)amountofvarianceinmostpredictionequations,however,itscontributionwascomparabletoanadditionalanthropometricvariable.

简介：自愿的云是云计算的一个新范例。它与一些好预备的云一起提供一种其他的选择。然而，在不明确的时间跨越那参加者份额他们在自愿的云的计算资源，有一些，质问问题，即，变化，在能力下面并且低利益。在这份报纸，体系结构首先基于Bittorrent协议被建议。在这体系结构，资源能从保留的例子市场被保留或请求并且能在一个短圆与更低的价格被存取。实际上，这些资源能填满不适当的资源在自愿的云分享并且减轻变化和在能力下面问题。然后，每个节点的差错率被用来评估它的分享的时间的无常。由利用一个线性预言模型，它被被用于评估系统的计算能力的一个分发函数启用。而且，费用优化问题被调查，一个计算方法被介绍在自愿的云解决低利益的问题。最后，系统表演被模拟的二个集合验证。并且试验性的结果为资源保留优化显示出我们的计算方法的有效性。

简介：Background：Thesteady-stateincreaseinmuscleforcegeneratingpotentialfollowingalengtheningcontractioniscalledresidualforceenhancement（RFE）.Inthisstudy,weaimedtotestfordifferencesintorque,electromyographicactivity（EMG）,andtheassociatedneuromuscularefficiency（NME）betweenisometricvoluntarycontractionsofelbowflexorsprecededandnotprecededbyalengtheningcontraction.Thedependenceofsuchdifferenceson（i）stretchamplitude,（ii）theregionoftheforce-length（FxL）relationshipwherecontractionoccurs,and（iii）theindividual＇sabilitytoproduce（negative）workduringthestretchwasinvestigated.Methods：Sixteenhealthyadultsparticipatedinthestudy.Elbowflexortorque,angle,andbicepsbrachiiEMGforpurelyisometriccontractions（referencecontractions）andforisometriccontractionsprecededbyactivestretchesof20°and40°weremeasuredattheascending,plateau,anddescendingregionsofsubject-specificFxLcurves.Allcontractionswereperformedinanisokineticdynamometer.Two-factor（stretch×FxLregion）repeatedmeasuresanalysisofvarianceANOVAswasusedtoanalyzetheeffectofactivestretchonEMG,torque,andNMEacrossconditions.Therelationshipsbetweenmechanicalworkduringstretch-calculatedasthetorque-angulardisplacementintegral-andthechangesinEMG,torque,andNMEwereanalyzedusingPearsoncorrelation.Results：Ingeneral,torque,EMG,andNMEfollowingactivestretchesdifferedfromthevaluesobservedforthepurelyisometricreferencecontractions.WhilealthoughthedetailedeffectsofactivestretchontorqueandEMGdifferedbetweenregionsoftheFxLrelationship,NMEincreasedbyabout19%forallmusclelengths.Upto30%oftheinterindividualvariabilityintorquegeneratingpotentialchangeinresponsetoactivestretchingwasaccountedforbydifferencesin（negative）workcapacitybetweensubjects.Conclusion：Ourresultssuggestthat（i）RFEcontributesto＂flatten＂theelbowflexortorque-anglerela

简介：Duringeccentriccontractions,muscularforceproductioncapacityisenhancedcomparedtoisometriccontractions.Althoughthisiswellacceptedintermsofmusclemechanics,maximalvoluntaryeccentriccontractionsareassociatedwithneuralinhibitionthatpreventsincreasedforceproductionofinvivohumanmuscles.However,becauseitwasshownthatmaximalvoluntaryeccentricforcescanexceedmaximumisometricforcesbyafactorof1.2-1.4,thisreviewfocusesonthequestionofwhethertheabsenteccentricforceenhancement,asobservedinmanystudies,canunambiguouslybeattributedtoaninherentneuralinhibition.First,wedemonstratethatparticipantfamiliarization,preload,andfasciclebehaviorarecrucialfactorsinfluencingmaximalvoluntaryeccentricforceproduction.Second,weshowthatmusclemechanicssuchasmusclelength,lengtheningvelocity,andstretchamplitudeinteractwhenitcomestomaximalvoluntaryeccentricforceproduction.Finally,wediscussthedivergingfindingsonneuralinhibitionduringmaximalvoluntaryeccentriccontractions.Becausetherewasnoinhibitionofthemajormotorpathwaysinthepresenceofenhancedmaximalvoluntaryeccentricforces,furtherresearchisneededtotesttheconceptofneuralinhibitionandtounderstandwhymaximalvoluntaryforceproductionisreducedcomparedtotheforcecapacityofisolatedmusclepreparations.

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简介：Runningisbelievedtobebeneficialforhumanhealth.Manystudieshavefocusedontheneuroprotectiveeffectsofvoluntaryrunningonanimalmodels.Therewerebothprimaryandsecondarydegenerationinneurodegenerativediseases,includingglaucoma.However,whetherrunningcandelayprimaryorsecondarydegenerationorbothofthemwasnotclear.Partialopticnervetransectionmodelisavaluableglaucomamodelforstudyingbothprimaryandsecondarydegenerationbecauseitcanseparateprimary(mainlyinthesuperiorretina)fromsecondary(mainlyintheinferiorretina)degeneration.Therefore,wecomparedthesurvivalofretinalganglioncellsbetweenSprague-Dawleyratrunnersandnon-runnersbothinthesuperiorandinferiorretinas.Excitotoxicity,oxidativestress,andapoptosisareinvolvedinthedegenerationofretinalganglioncellsinglaucoma.Sowealsousedwesternimmunoblottingtocomparetheexpressionofsomeproteinsinvolvedinapoptosis(phospho-c-JunN-terminalkinases,p-JNKs),oxidativestress(manganesesuperoxidedismutase,MnSOD)andexcitotoxicity(glutaminesynthetase)betweenrunnersandnon-runnersafterpartialopticnervetransection.Resultsshowedthatvoluntaryrunningdelayedthedeathofretinalganglioncellsvulnerabletoprimarydegenerationbutnotthosetosecondarydegeneration.Inaddition,voluntaryrunningdecreasedtheexpressionofglutaminesynthetase,butnottheexpressionofp-JNKsandMnSODinthesuperiorretinaafterpartialopticnervetransection.Theseresultsillustratedthatprimarydegenerationofretinalganglioncellsmightbemainlyrelatedwithexcitotoxicityratherthanoxidativestress;andthevoluntaryrunningcoulddown-regulateexcitotoxicitytodelaytheprimarydegenerationofretinalganglioncellsafterpartialopticnervetransection.

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