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41.
植物来源抗虫基因的研究进展   总被引:3,自引:0,他引:3  
植物抗虫基因工程为农林业生产中的害虫防治提供了新的途径,随着研究的不断深入,已经获得了很多抗虫基因。本文综述了目前源于植物的抗虫基因的种类,归纳了研究较多的抗虫基因的作用机制及其在转基因植物中的应用,提出了植物抗虫基因在虫害防治中面临的问题及相应的解决策略,展望了植物抗虫基因工程研究发展的方向和前景。  相似文献   
42.
Questions: 1. Which plant traits and habitat characteristics best explain local above‐ground persistence of vascular plant species and 2. Is there a trade‐off between local above‐ground persistence and the ability for seed dispersal and below‐ground persistence in the soil seed bank? Locations: 845 long‐term permanent plots in terrestrial habitats across the Netherlands. Methods: We analysed the local above‐ground persistence of vascular plants in permanent plots (monitored once a year for ca. 16 year) with respect to functional traits and habitat preferences using survival statistics (Kaplan‐Meier analysis and Cox’ regression). These methods account for censored data and are rarely used in vegetation ecology. Results: Local above‐ground persistence is determined by both functional traits (especially the ability to form long‐lived clonal connections) and habitat preferences (especially nutrient requirements). Above‐ground persistence is negatively related to the ability for dispersal by wind and to the ability to accumulate a long‐term persistent soil seed bank (‘dispersal through time’) and is positively related to the ability for dispersal by water. Conclusions: Most species have a half‐life expectation over 15 years, which may contribute to time lags after changes in habitat quality or ‐configuration (‘extinction debt’). There is evidence for a trade‐off relationship between local above‐ground persistence and below‐ground seed persistence, while the relationship with dispersal in space is vector specific. The rate of species turnover increases with productivity.  相似文献   
43.
张学雷  陈杰  龚子铜 《生态学报》2004,24(5):1063-1072
介绍了土壤多样性理论的基本概念与研究方法以及在西班牙、美国等欧美国家的研究实践 ,包括在欧盟 CORINE数据库和美国 STATSGO数据库支持下进行的多样性主要指数 (多样性指数、均匀度指数和多度指数等 )的算法、主要模型 (多度分布模型、幂律模型等 )的分析、GIS和地统计学方法的应用等。通过这些研究实践 ,可以看出土壤多样性理论在研究土壤的空间可变性、土壤景观格局的相互关系 ,土地利用与城市化过程对土壤多样性的影响等方面确有独到之处 ,为解决当前我国土壤学面临的环境资源可持续发展、环境监控、基因保护、城市化过程等热点问题提供了一个崭新的研究思路 ,展现出良好的应用前景  相似文献   
44.
Obtaining ‘informed consent’ from every individual participant involved in health research is a mandatory ethical practice. Informed consent is a process whereby potential participants are genuinely informed about their role, risk and rights before they are enrolled in the study. Thus, ethics committees in most countries require ‘informed consent form’ as part of an ethics application which is reviewed before granting research ethics approval. Despite a significant increase in health research activity in low‐and middle‐income countries (LMICs) in recent years, only limited work has been done to address ethical concerns. Most ethics committees in LMICs lack the authority and/or the capacity to monitor research in the field. This is important since not all research, particularly in LMICs region, complies with ethical principles, sometimes this is inadvertently or due to a lack of awareness of their importance in assuring proper research governance. With several examples from Nepal, this paper reflects on the steps required to obtain informed consents and highlights some of the major challenges and barriers to seeking informed consent from research participants. At the end of this paper, we also offer some recommendations around how can we can promote and implement optimal informed consent taking process. We believe that paper is useful for researchers and members of ethical review boards in highlighting key issues around informed consent.  相似文献   
45.
木根黄芩(Scutellaria planipes Nakai et Kitag.)是唇形科黄芩属(Scutellaria L.)多年生草本,目前仅发现在辽宁省凌源市境内有零星分布,被辽宁省列为三级保护植物。该种发表于1934年,但《中国植物志》、Flora of China、《中国生物物种名录》均将其定为京黄芩(Scutellaria pekinensis Maxim.)的异名。为了阐明二者的差异性,本文首先对木根黄芩的原始文献、模式标本、模式产地、历史分布区及现今发现地进行考证,其次对二者进行差异比较研究,认为木根黄芩与京黄芩无论在分布范围和生境上,还是在宏观外部形态和微观花粉粒形态上均存在明显差异,确定木根黄芩为独立种,同时还对木根黄芩的果实进行形态补充描述。本文确定木根黄芩独立种的地位,对保护野生木根黄芩具有重要意义,同时对其药用价值的进一步研究提供了更为清晰的样本。  相似文献   
46.
To help ensure the ethical conduct of research, many have recommended educational efforts in research ethics to investigators and members of research ethics committees (RECs). One type of education activity involves multi‐day workshops in research ethics. To be effective, such workshops should contain the appropriate content and teaching techniques geared towards the learning styles of the targeted audiences. To ensure consistency in content and quality, we describe the development of a curriculum guide, core competencies and associated learning objectives and activities to help educators organize research ethics workshops in their respective institutions. The curriculum guide is divided into modular units to enable planners to develop workshops of different lengths and choose content materials that match the needs, abilities, and prior experiences of the target audiences. The content material in the curriculum guide is relevant for audiences in the Middle East, because individuals from the Middle East who participated in a Certificate Program in research ethics selected and developed the training materials (e.g., articles, powerpoint slides, case studies, protocols). Also, many of the activities incorporate active‐learning methods, consisting of group work activities analyzing case studies and reviewing protocols. The development of such a workshop training curriculum guide represents a sustainable educational resource to enhance research ethics capacity in the Middle East.  相似文献   
47.
植物病原真菌致病毒素草酸的研究进展   总被引:4,自引:1,他引:4  
景岚  康振生 《西北植物学报》2003,23(12):2223-2228
许多植物病原菌可以分泌草酸,草酸作为致病的关键因子在病原菌的侵染过程中发挥着重要作用,并与病原菌的致病性、毒性有密切关系。草酸可通过氧化和脱羧两条途径进行降解,因此可以将草酸降解酶基因导入植物,从而获得对这类病害的抗性。  相似文献   
48.
In the United States, the Native American Graves Protection and Repatriation Act (NAGPRA) provides a specific framework for the disposition of Native American Ancestral remains within its purview. However, samples such as a bone fragment, tooth, or other biological tissue taken from the remains of these Ancestors have been treated by institutions and researchers as independent of the individual from whom they were removed and used in destructive research such as paleogenomic and other archaeometric analyses without consultation, consent, and collaboration from Native American communities; are not cared for in keeping with the current best practices for Indigenous Ancestors; and are not likely to be repatriated to their communities. Here, we demonstrate that any biological samples removed from Ancestors who are covered under NAGPRA must also be handled according to the stipulations defined for “human remains” within the legislation. As such, we are not proposing a change to existing legislation, but rather best practices, specific to the context of the United States and NAGPRA, relating to the use of and care for biological samples taken from Native American Ancestors.  相似文献   
49.
The Japanese Tsukuba Primate Center for Medical Science (TPC): an outline   总被引:2,自引:0,他引:2  
The facilities and activities of the Japanese Primate Center at Tsukuba, Japan are described. The Center became partially functional in 1978 and was completed in 1979. The three main aims of the Primate Center are: to quarantine newly imported primate animals, to breed, and to study them.  相似文献   
50.
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