生物信息学英文术语及释义总汇Word格式文档下载.doc

生物信息学英文术语及释义总汇Word格式文档下载.doc

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AuniqueidentifierthatisassignedtoasingledatabaseentryforaDNAorproteinsequence.

Affinegappenalty（一种设置空位罚分策略）

Agappenaltyscorethatisalinearfunctionofgaplength,consistingofagapopeningpenaltyandagapextensionpenaltymultipliedbythelengthofthegap.Usingthispenaltyschemegreatlyenhancestheperformanceofdynamicprogrammingmethodsforsequencealignment.SeealsoGappenalty.

Algorithm（算法）

Asystematicprocedureforsolvingaprobleminafinitenumberofsteps,typicallyinvolvingarepetitionofoperations.Oncespecified,analgorithmcanbewritteninacomputerlanguageandrunasaprogram.

Alignment（联配/比对/联配）

Referstotheprocedureofcomparingtwoormoresequencesbylookingforaseriesofindividualcharactersorcharacterpatternsthatareinthesameorderinthesequences.Ofthetwotypesofalignment,localandglobal,alocalalignmentisgenerallythemostuseful.SeealsoLocalandGlobalalignments.

Alignmentscore（联配/比对/联配值）

Analgorithmicallycomputedscorebasedonthenumberofmatches,substitutions,insertions,anddeletions（gaps）withinanalignment.ScoresformatchesandsubstitutionsArederivedfromascoringmatrixsuchastheBLOSUMandPAMmatricesforproteins,andaftinegappenaltiessuitableforthematrixarechosen.Alignmentscoresareinlogoddsunits,oftenbitunits（logtothebase2）.Higherscoresdenotebetteralignments.SeealsoSimilarityscore,Distanceinsequenceanalysis.

Alphabet（字母表）

Thetotalnumberofsymbolsinasequence-4forDNAsequencesand20forproteinsequences.

Annotation（注释）

Thepredictionofgenesinagenome,includingthelocationofprotein-encodinggenes,thesequenceoftheencodedproteins,anysignificantmatchestootherProteinsofknownfunction,andthelocationofRNA-encodinggenes.Predictionsarebasedongenemodels;

e.g.,hiddenMarkovmodelsofintronsandexonsinproteinsencodinggenes,andmodelsofsecondarystructureinRNA.

AnonymousFTP（匿名FTP）

WhenaFTPserviceallowsanyonetologin,itissaidtoprovideanonymousFTPser-vice.AusercanlogintoananonymousFTPserverbytypinganonymousastheusernameandhisE-mailaddressasapassword.MostWebbrowsersnownegotiateanonymousFTPlogonwithoutaskingtheuserforausernameandpassword.SeealsoFTP.

ASCII

TheAmericanStandardCodeforInformationInterchange（ASCII）encodesunaccentedlettersa-z,A-Z,thenumbersO-9,mostpunctuationmarks,space,andasetofcontrolcharacterssuchascarriagereturnandtab.ASCIIspecifies128charactersthataremappedtothevaluesO-127.ASCIItilesarecommonlycalledplaintext,meaningthattheyonlyencodetextwithoutextramarkup.

BACclone（细菌人工染色体克隆）

BacterialartificialchromosomevectorcarryingagenomicDNAinsert,typically100–200kb.Mostofthelarge-insertclonessequencedintheprojectwereBACclones.

Back-propagation（反向传输）

Whentrainingfeed-forwardneuralnetworks,aback-propagationalgorithmcanbeusedtomodifythenetworkweights.Aftereachtraininginputpatternisfedthroughthenetwork,thenetwork’soutputiscomparedwiththedesiredoutputandtheamountoferroriscalculated.Thiserrorisback-propagatedthroughthenetworkbyusinganerrorfunctiontocorrectthenetworkweights.SeealsoFeed-forwardneuralnetwork.

Baum-Welchalgorithm（Baum-Welch算法）

AnexpectationmaximizationalgorithmthatisusedtotrainhiddenMarkovmodels.

Baye’srule（贝叶斯法则）

Formsthebasisofconditionalprobabilitybycalculatingthelikelihoodofaneventoccurringbasedonthehistoryoftheeventandrelevantbackgroundinformation.IntermsoftwoparametersAandB,thetheoremisstatedinanequation:

Thecondition-alprobabilityofA,givenB,P（AIB）,isequaltotheprobabilityofA,P（A）,timestheconditionalprobabilityofB,givenA,P（BIA）,dividedbytheprobabilityofB,P（B）.P（A）isthehistoricalorpriordistributionvalueofA,P（BIA）isanewpredictionforBforaparticularvalueofA,andP（B）isthesumofthenewlypredictedvaluesforB.P（AIB）isaposteriorprobability,representinganewpredictionforAgiventhepriorknowledgeofAandthenewlydiscoveredrelationshipsbetweenAandB.

Bayesiananalysis（贝叶斯分析）

Astatisticalprocedureusedtoestimateparametersofanunderlyingdistributionbasedonanobserveddistribution.SeealsoBaye’srule.

Biochips（生物芯片）

Miniaturizedarraysoflargenumbersofmolecularsubst