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ABSTRACT An assessment on the biological control potential with the fish muddy loaches (Misgurnus mizolepis) was conducted against naturally bred Culex pipiens pollens larvae in four ponds (A, B, C and D) in Busan from July through September, 2001. Predation of the fish at 3 different release rates of 4,5, and 6 fish/m2 resulted in mostly over 90% mosquito control from the first week after treatment through the end of the survey period for 11 weeks. There were no significant difference among the release rates of fish at the 5% level of probability. However, substantial controls of 43.0% and 25.9% were obtained from pond C during the 3rd and 7th weeks after the fish introduction, respectively. The results of those two weeks showed a lower biological control by the introduced larvivorous fishes. This might be due to the presence of heavy organic matters including aquatic weeds and/or severely polluted water from sewage in pond C. The aquatic weeds covered the pond's water surface which may have affected the deterioration of mosquito preying in favor of aquatic weeds. Also, the fishes were observed to avoid severely contaminated sewage water in some parts of ponds A and C where more mosquito larvae were found.  相似文献   
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Large miliolid foraminifers of the subfamily Soritinae bear symbiotic dinoflagellates morphologically similar to the species of the "Symbiodinium" complex, commonly found in corals and other marine invertebrates. Soritid foraminifers are abundant in coral reefs and it has been proposed that they share their symbionts with other dinoflagellate-bearing reef dwellers. In order to test this hypothesis, we have analysed partial large subunit ribosomal DNA sequences from dinoflagellates symbionts obtained from 28 foraminiferal specimens, and compared them to the corresponding sequences of Symbiodinium-like endosymbionts from various groups of invertebrates. Phylogenetic analysis of our data shows that all soritid symbionts belong to the "Symbiodinium" species complex, within which they form seven different molecular types (Frl-Fr7). Only one of these types (Fr1) branches within a group of invertebrate symbionts, previously described as type C. The remaining six types form sister groups to coral symbionts previously designed as types B, C, and D. Our data indicate a high genetic diversity and specificity of Symbiodinium-like symbionts in soritids. Except for type C, we have found no evidence for the transmission of symbionts between foraminifers and other symbiont-bearing invertebrates from the same localities. However, exchanges must have occurred frequently between the different species of Soritinae, as suggested by the lack of host specificity and some biogeographical patterns observed in symbiont distribution. Our data suggest that members of the subfamily Soritinae acquired their symbionts at least three times during their history, each acquisition being followed by a rapid diversification and independent radiation of symbionts within the foraminiferal hosts.  相似文献   
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从广西产眼镜王蛇(Ophiophagus hannah)毒腺中抽提总RNA,经mRNA纯化后构建眼镜王蛇毒腺cDNA文库。从所构建的cDNA文库中,随机筛选200个克隆测序,得到两个在进化上高度保守的基因:泛素融合蛋白基因(GenBank登录号为AF297036)和核糖体蛋白L30基因(GenBank登录号是AF297033)。前者cDNA的开放阅读框为387bp,后者为348bp。前者编码128个氨基酸残基组成的泛素融合蛋白前体;后者编码115个氨基酸残基组成的核糖体蛋白L30前体。由cDNA序列推导出的氨基酸序列分析表明,泛素融合蛋白前体包括N-末端的泛素结构域(76个氨基酸残基)和C-末端的核糖体蛋白L40结构域(52个氨基酸残基)。该蛋白为一高碱性蛋白,C末端含有一个“锌指”模式结构。与16个物种比较的结果表明,眼镜王蛇与脊椎动物的泛素融合蛋白氨基酸序列相似度较高,具有高度的保守性。  相似文献   
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(一)乙型脑炎疫苗在用每分钟2,000转的速度沉澱20分钟後,疫苗中的总氮含量此较不沉澱的减少50%以上,但是疫苗的效价不论在其制成时或在保存一年的各时期 内,都没有比不沉澱的低。 (二)用含有5%的乳醣和一些鹽灰的溶液裂偏的疫苗的免疫效僵在各保存时期内都比用普通的生理鹽水制偏的疫苗为高,而且比较稳定。 (三)本文同时讨论了福尔马林的使用量和疫苗中蛋白質的含量的关系。  相似文献   
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详细地记述了韩国红松球果害虫冷杉梢斑螟Dioryctria abietella、赤松梢斑螟D. sylvestrella (螟蛾科)和小花尺蛾Eupithecia abietaria debrunneata (尺蛾科)幼虫的形态特征,并提供了形态特征图。  相似文献   
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