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简介:Humankinddrawsimportantbenefitsfromlarge-scaleecologicalprocessestermedecosystemservices,yetthestatusofseveralofthemisdeclining.Reliablemonitoringmethodsareessentialfortrackingthestatusofecosystemservices.Predationisthemainstayofnaturalpestcontrol,akeyecosystemservice.Weusedgreenplasticinecaterpillarstomonitorpredationpressure,andtoobtainbaselinedataonpredatoractivityintransgenicBtversusnon-BtmaizefieldsinOldandNewWorldcountries.Predationpressurewasmeasuredatgroundandcanopylevelsusinganidentical,small-plotexperimentaldesigninfourEuropeancountries(Denmark,Slovakia,RomaniaandItaly)andArgentina.Totalpredationrateinmaizewasll.7%d^-1(min.7.2%d^-1inArgentina,max.29.0%d^-1inRomania).Artificialcaterpillarswereattackedbothbyinvertebrates(mostlychewinginsectswith42.0%oftheattackmarks,andantswith7.1%,butalsopredatoryandparasitoidwasps,spidersandslugs),andvertebrates(smallmammals25.5%,andbirds20.2%).Totalpredationatgroundlevel(15.7%d^-1)wassignificantlyhigherthaninmaizecanopies(6.0%d^-1)inallcountries,exceptArgentina.WefoundnosignificantdifferencesbetweenpredatorpressureinBtversusnon-Btmaizeplots.Theartificialcaterpillarmethodprovidedcomparable,quantitativedataonpredationintensity,andprovedtobesuitableformonitoringnaturalpestcontrol.Thismethodusefullyexpandstheexistingtoolkitbydirectlymeasuringecologicalfunctionratherthanstructure.
简介:Wepresentarapidsystemforpredictingbeeftendernessbymimickingthehumantactilesense.ThedetectionsystemincludesaFSpressuresensor,apowersupplyconversioncircuit,asignalamplifierandaboxinwhichthesampleismounted.AsampleofrawLongissimusdorsi(LD)muscleisplacedinthemeasuringbox;thenarodconnectedtothepressuresensorispressedintothebeefsampletoagivendepth;thereactionforceofthebeefsampleismeasuredandusedtopredictthetenderness.SensoryevaluationandWarner-BratzlerShearForce(WBSF)evaluationofsamplesfromthesameLDmuscleareusedforcomparison.Thenewdetectionsystemagreeswithestablishedprocedure95%ofthetime,andthetimetotestasampleislessthan5minutes.
简介:Thesurfaceglycoproteinhemagglutinin(HA)helpstheinfluenzaAvirustoevadethehostimmunesystembyantigenicvariationandisamajordrivingforceforviralevolution.Inthisstudy,theselectionpressureonHAofH5N1influenzaAviruswasanalyzedusingbioinformaticsalgorithms.Mostoftheidentifiedpositiveselection(PS)siteswerefoundtobewithinoradjacenttoepitopesites.SomeoftheidentifiedPSsitesareconsistentwithpreviousexperimentalstudies,providingfurthersupporttothebiologicalsignificanceofourfindings.ThehighestfrequencyofPSsiteswasobservedinrecentstrainsisolatedduring2005–2007.PhylogeneticanalysiswasalsoconductedonHAsequencesfromvarioushosts.Viraldriftisalmostsimilarinbothavianandhumanspecieswithaprogressivetrendovertheyears.OurstudyreportsnewmutationsinfunctionalregionsofHAthatmightprovidemarkersforvaccinedesignorcanbeusedtopredictisolatesofpandemicpotential.
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.