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31 个结果
  • 简介:Horizontalgenetransfer(HGT)haslongbeenconsideredasaprincipalforceforanorganismtogainnovelgenesingenomeevolution.Homologysearch,phylogeneticanalysisandnucleotidecompositionanalysisarethreemajorobjectiveapproachestoarguablydeterminetheoccurrenceanddirectionalityofHGT.Here,21genesthatpossessthepotentialtohorizontaltransferwereacquiredfromthewholegenomeofMagnaporthegriseaaccordingtoannotation,amongwhichthreecandidategenes(correspondingproteinaccessionnumbersareEAA55123,EAA47200andEAA52136)wereselectedforfurtheranalysis.AccordingtoBLASThomologyresults,wesubsequentlyconductedphylogeneticanalysisofthethreecandidateHGTgenes.Moreover,nucleotidecompositionanalysiswasconductedtofurthervalidatetheseHGTs.Inaddition,thefunctionsofthethreecandidategenesweresearchedinCOGdatabase.Consequently,weconcludethatthegeneencodingproteinEAA55123istransferredfromClostridiumperfringens.AnotherHGTeventisbetweenEAA52136andacertainmetazoan'scorrespondinggene,butthedirectionremainsuncertain.Yet,EAA47200isnotatransferredgene.

  • 标签: 水平基因转移 稻瘟病菌 机理分析 系统发育分析 水平转移 编码蛋白质
  • 简介:ThemineralresourcesexploitationstageandtheeconomicgrowthratearevariousindifferentregionsofXinjiangAutonomousregion.Usingthemethodoflocationquotient,thispaperidentifiesandclassifiestheintensiveregionsofthreetypesofmineralresources,knownascoal,oilandnaturalgas,respectively.Theintensiveregionsofeconomicgrowthwerealsoidentified,accordingtotherateofpercapitaGDPgrowthatprefecture,autonomousprefectureandcity.Therelationshipsbetweendifferentmineralresourcesandeconomicgrowtharedifferent,forexample,therelationshipbetweeneconomicgrowthandcoalresourceispositive,whiletherelationshipbetweeneconomicgrowthandoilresource,ornaturalgasresourceisnegative.ThisstudyempiricallyexaminestheeffectsofnaturalresourcesoneconomicgrowthofXinjiang.Theresultsshowthatwhilstnaturalresourceshaveapositiveimpactongrowth,andcanmakeanegativeimpactongrowththroughthetransmissionchannels,suchasinvestment,manufacture,humancapital,andscientificandtechnologicinnovation.Moreover,itstudiesthetransmissionchannels,thatis,theeffectofnaturalresourcesontheotherexplanatoryvariables,andcalculatestheindirecteffectofnaturalresourcesongrowthforeachtransmissionchannel,andcomprehensiveeffectsofnaturalresourcesongrowth.ThecalculatedresultofcomprehensiveeffectsindicatesthatthepositivedirecteffectsofnaturalresourcesongrowthareshowntooutweighthenegativeindirecteffectofXinjiangautonomousregion.

  • 标签: 矿产资源开发 经济增长率 新疆自治区 自然资源 天然气资源 假说
  • 简介:Thenumberofcompletelysequencedarchaealgenomeshasbeensufficientforalarge-scalebioinformaticstudy.Wehaveconductedanalysesforeachcodingregionfrom36archaealgenomesusingtheoriginalCGSalgorithmbycalculatingthetotalGCcontent(G+C),GCcontentinfirst,secondandthirdcodonpositionsaswellasinfourfoldandtwofolddegeneratedsitesfromthirdcodonpositions,levelsofargininecodonusage(Arg2:AGA/G;Arg4:CGX),levelsofaminoacidusageandtheentropyofaminoacidcontentdistribution.InarchaealgenomeswithstrongGCpressure,arginineiscodedpreferablybyGC-richArg4codons,whereasinmostofarchaealgenomeswithG+C<0.6,arginineiscodedpreferablybyAT-richArg2codons.InthegenomeofHaloquadratumwalsbyi,whichiscloselyrelatedtoGC-richarchaea,GCcontenthasdecreasedmostlyinthirdcodonpositions,whileArg4>>Arg2biasstillpersists.Proteomesofarchaealspeciescarrycharacteristicaminoacidbiases:levelsofisoleucineandlysineareelevated,whilelevelsofalanine,histidine,glutamineandcytosinearerelativelydecreased.NumerousgenomicandproteomicbiasesobservedcanbeexplainedbythehypothesisofpreviouslyexistedstrongmutationalATpressureinthecommonpredecessorofallarchaea.

  • 标签: 压力突变 蛋白质组 基因组 假说 氨基酸含量 GC含量
  • 简介:TeachingEnglishasacompulsorysubjectinCenderawasihUniversityhasalwaysbeenachallengingone.ThesituationandconditionfacedbythelecturerswhoarefromEnglisheducationprogramarecomplex.TheyhavetoteachEnglishinthefirstyear,sometimesuntilsecondyearfornon-Englishmajorstudentsfromdifferentprograms.Atthesametime,theydealwithbigclassesfromallprograms.Issuesintheteachingandlearningprocessintheclassroommayincludetotalnumberofstudents,students’backgroundknowledgeoflearningEnglish,learningconditions,andteachingandlearningstyle.Sincetheseissueshavehappenedthroughouttheyears,severalelementsfromKrashenhypothesiscanbeconsideredtohelptocreateabetterlanguagelearningenvironment.Thisstudyfocusesonthoseelementsofcomprehensibleinput,reducedanxietylevel,andactiveparticipation.TheseelementscanbeurgentlysuggestedtoEnglishteachingandlearningprocessatuniversitylevel,particularlytoteachEFL(Englishasaforeignlanguage)tomixed-levelnon-Englishmajoruniversitystudentstoproduceaneffectivelanguagelearningenvironment.

  • 标签: KRASHEN HYPOTHESIS mixed level NON-ENGLISH major
  • 简介:Wereportacompletegenomicsequenceofrareisolates(minorgenotype)oftheSARS-CoVfromSARSpatientsinGuangdong,China,wherethefirstfewcasesemerged.Themoststrikingdiscoveryfromtheisolateisanextra29-nucleotidesequencelocatedatthenucleotidepositionsbetween27,863and27,864(referredtothecompletesequenceofBJ01)withinanoverlappedregioncomposedofBGI-PUP5(BGI-postulateduncharacterizedprotein5)andBGI-PUP6upstreamoftheN(nucleocapsid)protein.Thediscoveryofthisminorgenotype,GD-Ins29,suggestsasignificantgeneticeventanddifferentiatesitfromthepreviouslyre-portedgenotype,thedominantformamongallsequencedSARS-CoVisolates.A17-ntsegmentofthisextrasequenceisidenticaltoasegmentofthesamesizeintwohumanmRNAsequencesthatmayinterferewithviralgenomereplicationandtranscriptioninthecytosoloftheinfectedcells.Itprovidesanewavenuefortheexplorationofthevirus-hostinteractioninviralevolution,hostpathogenesis,andvaccinedevelopment.

  • 标签: SARS 冠状病毒 基因序列 基因型
  • 简介:DearEditorialBoardMembers,ContributorsandFriendsofEEEV,AsweputtingtogetheraspecialsectionontheGreatWenchuanearthquake,thenearbyYa'an/Lushanareawasstruckbyanothermajorearthquakealmostfiveyearslater.Preliminaryreportsindicatethatthisrecenteventappeartohavecertainspecialcharacteristicssuchasthelargeaffectedareaandchanginggeotechnical/geologicalconfigurationsofthegroundalthoughitsgroundmotionintensitycomparablywassmallerthantheWenchuanearthquake.

  • 标签: 纤维增强塑料 应变协调 平面假设 表面贴装 钢筋混凝土梁 RC梁
  • 简介:AbstractDespite overwhelming evidence from large randomized clinical trials supporting a clear benefit of low-density lipoprotein cholesterol (LDL-C) lowering therapy on the primary and secondary prevention of atherosclerotic cardiovascular disease, data from epidemiological and clinical observations demonstrated an increased incidence of hemorrhagic stroke in patients with low LDL-C exposure (<70 mg/dL), especially among East Asians. Meanwhile, emerging studies have reported a paradoxical phenomenon in which hypercholesterolemia is associated with better short-term outcomes in acute coronary syndrome patients, the "lipid paradox." The underlying mechanism for these two closely connected clinical observations is not clear. This review aimed to summarize the evolution and clinical implications of these two low LDL-C related concepts, and proposed a "double-hit" hypothesis that may help explain these phenomena. It is worth noting that in the era of increasing use of high-intensity LDL-C lowering and dual antiplatelet strategies in atherosclerotic cardiovascular disease in patients receiving percutaneous coronary intervention, balancing the risk of thrombosis with bleeding complication should be a priority in clinical practice. Our hypothesis may raise clinicians’ awareness to identify potential high risk patients with low LDL-C (<70 mg/dL), especially among East Asians.

  • 标签: acute coronary syndrome bleeding hemorrhagic stroke lipid paradox risk factor