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本对新疆南、北疆、东疆地区和乌鲁木齐市的101所民族中学进行实地的调查研究,通过对各民族中学体育教学中大纲、教材、场地器材、汉语授课、男女生分班情况、教师培训、教学计划以及对课程改革的认识等方面的分析.进一步了解新疆各地区民族中学学校体育状况,特别是“体育与健康”课程实施后,各地区民族中学学校体育教学现状以及所面临的问题,旨在加快新疆少数民族中学的体育教学改革和《体育与健康》课程教学研究。为新疆教育主管部门制定实施“体育与健康”课程教学提供决策依据。  相似文献   
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Summary A method has been developed to measure orientation responeses of caterpillars to various sources of stimuli at predetermined distances on a grid of intersecting ribs indoors and outdoors.The authors are grateful to the University Grants Commission, New Delhi, for grant which partially supported this work and to the Council of Scientific and Industrial Research, New Delhi, for the Junior Research Fellowships to P. K. and S. G.  相似文献   
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In 1993, William Donachie wrote "The success of molecular genetics in the study of bacterial cell division has been so great that we find ourselves, armed with much greater knowledge of detail, confronted once again with the same naive questions that we set to answer in the first place". Indeed, attempts to answer the apparently simple question of how a bacterial cell divides have led to a wealth of new knowledge, in particular over the past decade and a half. And while some questions have been answered to a great extent since the early reports of isolation of division mutants of Escherichia coli, some key pieces of the puzzle remain elusive. In addition to it being a fundamental process in bacteria that merits investigation in its own right, studying the process of cell division offers an abundance of new targets for the development of new antibacterial compounds that act directly against key division proteins and other components of the cytoskeleton, which are encoded by the morphogenes of E. coli. This review aims to present the reader with a snapshot summary of the key players in E. coli morphogenesis with emphasis on cell division and the rod to sphere transition.  相似文献   
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ABSTRACT

Fireflies (Coleoptera: Lampyridae) are charismatic insects that have been fruitful model systems in biotechnology. However, lack of information about firefly taxonomy and ecology renders species identification a hard task, especially in the Neotropical region, where fireflies are most diverse. A major gap in the literature on Neotropical fireflies is the lack of knowledge on species’ ecological niches and habitats, which are fundamental aspects for understanding their biology. Here, we provide an annotated checklist of the firefly fauna of the Serra dos Órgãos mountain range (Rio de Janeiro State, Southeastern Brazil), with information on the natural history of each species. We assembled data in three ways: monthly sampling with Malaise traps and active search along an elevational transect from 130 to 2,170 m, over 2 years (2014–2016), extensive field observations, and extracted from historical species records for the Serra dos Órgãos from museum specimens in key collections in Brazil and Europe. We provide a taxonomic key to the genera recorded in the region, and a differential diagnosis for each species, highlighting key references for each taxon. We report 58 species representing 21 genera, making the Serra dos Órgãos one of the richest firefly hotspots on Earth. Most species are restricted to one or two habitat types and/or just one of the regional seasons (warm or cool), and many were only collected either by malaise traps or active search, underlining the importance of sampling different habitat types and seasons, and using different sampling methods when surveying fireflies. Out of the 51 species observed in the field, 49 were active either during the day or the night, although two species – Photuris elliptica and Pyrogaster nigrolineatus – were active in both periods, which is rare in fireflies.  相似文献   
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本文从理论和实践两个方面对动态投入产出法中动态投资的概念、投资系数的求取等进行了研究,提出了部门动态投资系数的求取方法,即一次性投资与多次性投资的综合方法。在此基础上,还给出了投资系数的修正方法,分析了影响投资系数求取的因素。最后,给出了投资系数求取过程中的误差分析方法。  相似文献   
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