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931.
水稻粘虫混合种群幼虫空间分布型测定结果表明:(1)频次分布检验为负二项分布;(2)聚集度指标测定为聚集分布;(3)m^*-m的钱性回归方程为m^*=0.8870 1.1058m,属于最普通的聚集分布。在分布型研究基础上,探讨了资料代换模式、Iwao序贯抽样模型和最适抽样数模型。 相似文献
932.
Karin M. Jger Christina Johansson Ulrike Kunz H. Lehmann 《Plant biology (Stuttgart, Germany)》1997,110(2):151-157
Element analysis using electron spectroscopic imaging (ESI) and electron energy loss spectroscopy (EELS) was performed in a symbiotic Nostoc sp. strain found in the upper stem tissue of Gunnera manicata, and in Nostoc PCC 9229, a free-living heterocyst-forming cyanobacterium able to enter into symbiosis with the angiosperm Gunnera in reconstitution experiments. ESI and EELS unequivocally identified the four elements nitrogen (N), sulphur (S), phosphorus (P) and oxygen (O) in different inclusion bodies of these biological specimens. High amounts of nitrogen were solely detected in huge cyanophycin granules in vegetative cells of the symbiotic Nostoc strain, whereas large polyphosphate bodies, containing high amounts of phosphorus, sulphur and oxygen, could be seen in the free-living Nostoc PCC 9229. The latter were usually not present or, when found, very small in vegetative cells of the cyanobiont. 相似文献
933.
本文介绍一种碱性磷酸酶标A蛋白加强的PAP技术。采用PAP技术、碱性磷酸酶标A蛋白(PAAP)技术PAAP和加强的PAP(PAP-PAAP)技术显示下丘脑室旁核催产素(OT)能神经元。结果发现,其中使用PAP-PAAP技术免疫反应产物的显色最深。此技术的原理可能是,由于A蛋白分子至少有四个位点能与IgG分子的Fc段高亲合性地结合,故在该技术中,先经过PAP程序的三步免疫反应并显色后,每个与一抗结合的二抗分子上和每个与二抗结合的PAP复合物分子上各暴露一个能与A蛋白分子结合的Fc段,在随后经过PAAP技术处理时,部分PAAP复合物分子就结合在这些Fc段上,经显色后,PAAP技术显示的浅紫兰色与PAP技术显示的浅棕褐色重叠,变成更深的反差明显的深棕褐色。 相似文献
934.
MARTIN BURD 《Biological journal of the Linnean Society. Linnean Society of London》1999,68(4):579-592
A common approach to modelling reproductive evolution in flowering plants includes an implicit assumption that module number and resource allocation per module follow an inverse hyperbolic trade-off. This assumption has not been thoroughly tested. In ten herbaceous and small woody species I examined phenotypic partial correlations between flower number (measured in relation to vegetative biomass) and each of three floral components: pollen number per flower, ovule number per flower, and corolla size. Significantly negative correlations between flower number and at least one of the floral components occurred in four of the ten species. These phenotypic correlations suggest the existence of true (genetically based) trade-offs, because environmental correlations are likely to be positive, but the significant negative relationships are linear except in one case. Thus, evolutionary tradeoffs involving flower number seem likely in some cases, but there is little to indicate that hyperbolic trade-offs are common. The phenotypic patterns investigated here cannot provide definitive answers about the form of trade-offs. Nonetheless, theoretical attention to the potential evolutionary consequences of trade-offs other than the implicit hyperbolic form is needed. 相似文献
935.
Metabolic pathways may be optimized with S-system models that prescribe profiles of control variables leading to optimal output while keeping metabolites and enzyme activities within predefined ranges. Monte Carlo simulations show how much the yield and the corresponding metabolite concentrations would be affected by inaccuracies in the experimental implementation of the prescribed profiles. For a recent model of citric acid production in Aspergillus niger, the yield is roughly normally distributed, whereas the distributions of metabolite concentrations differ greatly in shape and statistical characteristics. Even moderate inaccuracies may lead to constraint violations, which appear to be correlated with high logarithmic gains. 相似文献
936.
The succession of 38 upper Llandovery–lower Wenlock chitinozoan taxa from graptolitic horizons in the Banwy River section (Powys, Wales) is described. Five new species are named: Bursachitina nestorae Conochitina leviscapulae Conochitina mathrafalensis Belonechitina cavei Belonechitina meifodensis . A further ten taxa are described under open nomenclature. Seven chitinozoan biozones are recognized in the Banwy River section, three of which ( Cingulochitina bouniensis Conochitina acuminata Salopochitina bella ) are new. The base of each biozone is correlated with the graptolite biostratigraphical scheme as follows: Angochitina longicollis Biozone — upper spiralis Biozone; Conochitina acuminata Biozone — lowermost lapworthi Biozone; Margachitina banwyensis Biozone — upper lapworthi Biozone; Margachitina margaritana Biozone — lowermost insectus Biozone; Cingulochitina bouniensis Biozone — upper murchisoni Biozone; Salopochitina bella Biozone — upper firmus Biozone. The succession of chitinozoan biozones in the Banwy River section is compared with that in other sections which have graptolite biostratigraphical control. This has highlighted the following: (1) the correlation of the base of the dolioliformis Biozone with the graptolite biozonation is imprecise; (2) E. dolioliformis is recorded only from levels after the first A. longicollis in Sweden (although this may reflect previously unrecognized synonymies); (3) the longicollis Biozone may be diachronous, its base correlating with levels low in the Telychian in Sweden, Norway and Estonia and with the upper Telychian spiralis Biozone in Wales and the Prague Basin; (4) data herein and from the Prague Basin indicate that the base of the margaritana Biozone correlates with a level low in the insectus Biozone. 相似文献
937.
938.
Miki Shirakihara Kunio Shirakihara Jyunji Tomonaga Megumi Takatsuki 《Marine Mammal Science》2002,18(1):30-41
Residency patterns and population size were examined for Indo-Pacific bottlenose dolphins ( Tursiops aduncus ) in the coastal waters of Amakusa-Shimoshima Island, western Kyushu, Japan, from summer 1994 to fall 1998. A total of 203 individuals were identified. The number of newly identified individuals barely increased after the first 1.5 yr. The identified individuals in one season were frequently resighted with percentages of mostly over 60% during the subsequent seasons. Most of the dolphins off Amakusa were yearround residents, although the total range of their habitat was unknown. The population size estimated by the mark-recapture technique was 218 individuals with a CV of 5.41% in 1995–1997. The group commonly consisted of more than 100 individuals. The large group size was thought to be a response to feeding on schooling fishes. 相似文献
939.
KARINA LUCAS SILVA-BRANDÃO VERA NISAKA SOLFERINI 《Biological journal of the Linnean Society. Linnean Society of London》2007,90(2):247-261
Molecular phylogenetic analyses were conducted to determine relationships and to investigate character evolution for the Troidini/Aristolochia interaction, in an attempt to answer the following questions: (1) what is the present pattern of use of Aristolochia by these butterflies; (2) is the pattern we see today related to the phylogeny of plants or to their chemical composition; (3) can the geographical distribution of Aristolochia explain the host plant use observed today; and (4) how did the interaction between Troidini and Aristolochia evolve? Analyses of character optimization suggest that the current pattern of host plant use of these butterflies does not seem to be constrained by the phylogeny of their food plants, neither by the secondary chemicals in these plants nor by their geographical similarity. The current host plant use in these butterflies seems to be simply opportunistic, with species with a wider geographical range using more species of host plants than those with a more restricted distribution. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 90 , 247–261. 相似文献
940.
A. WATANABE M. G. IWAIZUMI M. UBUKATA T. KONDO C. LIAN T. HOGETSU 《Molecular ecology resources》2006,6(1):80-82
We developed seven microsatellite loci from Pinus densiflora using a dual polymerase chain reaction (PCR) technique. Of 186 clones from a library based on suppression PCR, 127 contained microsatellite sequences. Of these, 43 candidates were determined sequences of both flanking regions, and 16 regions from this group were chosen as development markers. Seven of these primer pairs successfully amplified polymorphic single loci among 83 resistant trees against pine wood nematode. The observed heterozygosity of the seven microsatellite markers ranged from 0.247 to 0.843. Mendelian inheritance was confirmed using megagametophytes. 相似文献