合成生物与生物安全          下载免费PDF全文

马延和  江会锋  娄春波  刘君  付钰  王钦宏  李寅 《中国科学院院刊》2016,31(4):432-438

合成生物学基于生物、化学、物理、计算、工程等多学科交叉,对生物体以工程化的方式重新设计甚至是从头合成,将克服自然进化的局限,创造超越自然生命能力的合成生物,不仅对探索生命活动基本规律具有重要科学意义,也在工农业生产、环境保护、健康保健等领域具有巨大应用前景。随着合成生物技术发展的日新月异,合成生物的应用范围日益广泛,如何保障合成生物的生物安全性成为一个极其重要并且亟待解决的关键问题。合成生物学研究中大量涉及来自于病毒、致病性细菌和真菌的强毒力基因元器件,且被设计和使用的毒性基因元件和调控元件的数目也从少数几个跃升为几十个、上百个,乃至整个基因组的重新设计和编辑改造。如果缺乏有效管控或被恶意谬用,这些人工合成生物体可能会对生态环境平衡、公共卫生安全乃至国家国防安全造成威胁。因此,在人工设计和改造生物体的过程中,必须建立系统的防范和监控体系,设计有效的方法和技术来阻止人工生命体在野外环境下的复制和增殖、遗传信息的漂移以及阻断其进化出新的环境适应性,做到完全的人工改造生物隔离,达到真正的人工可控生命目标,确保其生物安全性。文章综述了合成生物学的研究进展和合成生物潜在的生物安全性威胁,以及合成生物的生物安全性防控设计策略,并对相关安全政策规章的制定给出了建议。  相似文献   

基于ISM-Fuzzy AHP的我国中小企业核心竞争力要素分析   总被引：5，自引：0，他引：5  

楼迎军  荣先恒 《科研管理》2007,28(1):97-103

本文首先基于已有研究及调研结果,采用主成分分析法选出7个核心竞争力要素,并以苏州、杭州中小企业为例,通过问卷调查获取数据,并运用ISM-Fuzzy AHP模型分析法对中小企业核心竞争力要素进行实证研究。分析表明,我国企业已日益重视对人力资源、技术创新、市场营销、组织管理能力等核心竞争力要素的培育,但对企业文化的塑造仍不够重视。  相似文献   

Sensory exotropia subsequent to senile cataract     

楼定华  许叶圣  李毓敏 《Journal of Zhejiang University. Science. B》2005,6(12):1220-1222

INTRODUCTION Sensory exotropia is a condition of unilateral divergence as a sequela to loss of vision or long-standing poor vision in one eye,which was caused by refractive errors,unilateral aphakia or other organic reasons.Convergence insufficiency or disruption is possible.The most important aspect of the manage-ment is to find and/or eliminate and/or reverse a treatable cause of the exotropia.In clinic,the sensory exotropia secondary to senile cataract was often ob-served.Prospectively…  相似文献   

情境认知视野中的学习观及其教学模式   总被引：4，自引：0，他引：4  

张伟胜  楼广赤 《现代远程教育研究》2006,(5):50-52

教育者所具有的学习观和知识观会对他们采用什么样的教学方法产生决定性的影响。本文从知识观和学习观的角度对情境认知作了理论梳理,阐明了该理论中知识和学习所具有的特性,并阐释了与之内接的三种教学模式:抛锚式教学,随机进入教学,认知学徒制教学。  相似文献   

A methodological morass? How we can improve quantitative research in distance education     

Robert Bernard  Philip Abrami  Yiping Lou  Evgueni Borokhovski 《Distance Education》2004,25(2):175-198

This article is about the quantitative research practices and methodologies that are used in distance education (DE). It begins with an analysis and assessment of a segment of the DE research literature, DE/classroom comparison studies, based on a recently completed meta-analysis of that literature from 1985 to 2002. Overall, the 232 studies reviewed were judged to be of poor methodological quality and severely lacking in critical information about research practices. Studies of synchronous and asynchronous DE are discussed separately and recommendations are made for improving designs and measures within these patterns. Suggestions for future quantitative research areas are provided. In discussing these findings, we recognize that high-quality research is being conducted in the field and that qualitative forms of research contribute greatly to the mosaic of evidence that is the base of available knowledge about DE. Finally, three organizations, the What Works Clearinghouse (USA), EPPI-Centre (UK), and the Campbell Collaboration (international), all devoted to improving the quality of research and research synthesis in education, are described briefly; suggestions are made as to how their philosophies and approaches for judging the worthiness of research evidence can be used to improve DE research.  相似文献   

Schools as knowledge work organizations: Perspectives and implications from the new management literature     

Betty Lou Whitford  Ric A. Hovda 《The Urban Review》1986,18(1):52-70

The authors argue that the knowledge work metaphor is the most powerful image of schools for understanding reform. Using themes from the new management literature, such as shared decision making, collegiality, innovation, and experimentation, as additional guides for school improvement, the authors develop a case for systemic reform based on the professionalization of teaching and the integration of theory, research, and practice, Finally, transformational leadership is presented as the key to facilitating systemic reform.  相似文献   

"伴性遗传"的课堂教学     

娄维义 《生物学教学》2007,32(10):30-31

1 教材分析 上海科技版《生命科学》（试验本）高二第一学期[1]第1节第四部分内容是＂性别决定和伴性遗传＂,本节课＂伴性遗传＂是在学生了解性别决定的基础上展开的一节重要内容,是区别于常染色体遗传方式的另一种遗传方式.教材首先给出了伴性遗传的定义,然后指出红绿色盲是一种伴性遗传病,其致病基因为隐性基因Xb.通过图解得出红绿色盲的遗传规律,  相似文献   

Cesarean birth from three research perspectives          下载免费PDF全文

Moore ML 《The Journal of perinatal education》2004,13(4):50-52

Issues surrounding cesarean birth are of interest to researchers from varied disciplines and nations. In this column, three studies that examine aspects of cesarean birth are reviewed. One study presented a review of 11 studies and found differences in the perceptions of white and minority mothers toward labor, vaginal birth, and cesarean birth. In a second study on infant outcomes, Japanese researchers found differences in transient tachypnea in infants born in the first half of the 37th week gestation and those born in the second half of the 37th week and the 38th week of gestation. In a third study conducted in Norway, researchers found more complications when cesarean birth occurred at advanced dilation. The three studies' implications for childbirth educators are discussed.  相似文献   

浅析WebQuest的作用与局限     

何雪利  翁凡亚 《中国现代教育装备》2006,(9):50-52

从教学的角度分析WebQuest的作用,认为WebQuest有利于激发学生的学习兴趣;培养学生的探索、研究精神;有利于培养学生的团队协作意识,形成协作学习方式;有利于提高学生的思维水平,培养学生的创新意识和能力;有利于学生的全面发展。同时WebQuest还存在不适合所有课程内容的教学和学习、一定程度上限制了老师的思维、学生很难一直都保持较高的积极性和投入高水平的思维等局限性。  相似文献   

适应和引领新课改：教师教育功能的角色认知     

娄立志  张金泉 《教师教育研究》2008,20(2):21-25

随着我国新一轮基础教育课程改革的深入,教师教育面临新的挑战,其功能需要进行新的角色认知。本文认为,现阶段我国教师教育应该重新审视其与基础教育改革的关系,确立其适应和引领基础教育课程改革的新功能。变被动适应为主动适应,并能够积极引领基础教育的课程改革。为此,教师教育应该通过新课程理念的更新、新课程知识的储备、新课程技能的训练、新课程研究能力的提升,为推动我国新课程改革的进一步深化培育"新师资"。  相似文献