简介:Thereareabout17chromosomesinyeastSaccharomycescerevisiae.Amiddlesizedchromosome,chromosomeV,waschoseninthisworkforstudyingandconstructingthephysi-calmaps.ChromosomeVfromstrainA364awasisolatedbypulsed-fieldgradientgelelectrophoresis(PFGE).GelslicescontainingchromosomeVDNAweredigestedwithtworarecuttingenzymes,NotⅠandSfiⅠ,andthree6-Ntrecognizingenzymes,SmaⅠ,SstⅡandApaⅠ.Severalstrategies-partialorcompletedigestions,digestionwithdifferentsetsoftwoenzymes,andhybrid-izationwithclonedgeneticallymappedprobes(CAN1,URA3,CEN5,PRO3,CHO1,SUP19,RAD51,RAD3)——wereusedtoaligntherestrictionfragments.Thereare9,9,15,17,and20sitesforNotⅠ,SfiⅠ,SmaⅠ,SstⅡandApaⅠrespectivelyinthemapoftheA364achromosomeV.Itstotallengthwascalculatedtobe620Kb(Kilo-bases).Thedistributionsofthecuttingsitesforthesefiveenzymesthroughthewholechromosomearenotuniform.Acomp-arisonbetweenthephysicalmapandthegeneticmapwasalsomade.
简介:Microarrayhasbecomeapopularbiotechnologyinbiologicalandmedicalresearch.However,systematicandstochasticvariabilitiesinmicroarraydataareexpectedandunavoidable,resultingintheproblemthattherawmeasurementshaveinherent"noise"withinmicroarrayexperiments.Currently,logarithmicratiosareusuallyanalyzedbyvariousclusteringmethodsdirectly,whichmayintroducebiasinterpretationinidentifyinggroupsofgenesorsamples.Inthispaper,astatisticalmethodbasedonmixedmodelapproacheswasproposedformicroarraydataclusteranalysis.TheunderlyingrationaleofthismethodistopartitiontheobservedtotalgeneexpressionlevelintovariousvariationscausedbydifferentfactorsusinganANOVAmodel,andtopredictthedifferentialeffectsofGV(genebyvariety)interactionusingtheadjustedunbiasedprediction(AUP)method.ThepredictedGVinteractioneffectscanthenbeusedastheinputsofclusteranalysis.Weillustratedtheapplicationofourmethodwithageneexpressiondatasetandelucidatedtheutilityofourapproachusinganexternalvalidation.
简介:Threetypesofroughsurfacewereprocessedbylaserirradiationonthe3Cr2W8Vmaterialhot-workdiesteelsurface.Thewearexperimentswithsmoothsurfaceandroughsurfacesampleswererepeatedonthepin-traywearmachine.Accordingtothewearresults,westudiedtheregularityofwearresistanceofdifferentroughsurfacesamples.Theresultsindicatedthatbionicroughsurfacecanimprovethewearresistanceofthematerialandthewearresistancecanbeincreased1-2times,comparedwiththesmoothsurface.Also,thewearresistanceoftheroughsurfacewasaffectedbylasercurrentanddurationofimpulse.Thebiggerthelasercurrentortheimpulseduration,thebetteristhewearresistance.Whenthedistancebetweenthesamekindofunitswhicharedistributedonthesurfacesischanged,thewearresistancechanges.Thewearresistanceofabionicroughsurfaceonwhichthegridunitsweredistributedatspacingof1mmwasthebest.Andwedesignedthewearmodels.