RNAi的研究及应用

RNA干扰（RNA interference,RNAi）是由双链RNA（double-stranded RNA,dsRNA）引发的转录后基因沉默机制．RNAi可以调节和关闭基因的表达,进而调控细胞的各种高级生命活动,是真核生物中普遍存在的抵抗病毒入侵、抑制转座子活动、调控基因表达的监控机制．目前RNAi的研究取得了很大进展,有可能为肿瘤基因治疗提供新策略．     

中、日、韩三国集体球类项目竞技实力的比较研究

文章运用文献资料法、数理统计法与比较法等研究方法,对中国、日本与韩国在第26、27、28届夏季奥运会中的集体球类项目竞技实力进行深入研究,研究得出:中、日、韩三国整体竞技实力不稳定,表现出下降趋势,中国的实力稍强于韩国、日本;在男子方面,中国落后韩国与日本,韩国与日本的实力较近;在女子方面,中国拥有绝对优势,韩国实力下降,日本实力上升,韩国与日本之间的差距缩小     

RFLP原理及在作物基因定位和育种中的应用

系统介绍了RFLP的概念、原理、特点及其在实验操作中应注意的事项,总结了RFLP技术用于玉米、水稻等作物的基因定位以及在育种上的研究成果,最后讨论了RFLP技术在实践应用中存在的问题.     

关于N(2,2,0)代数的弱幂零元的若干结果(英文)

引入了N(2,2,0)代数的弱幂元的概念,讨论了其弱幂元的若干性质.     

The social structure of entrepreneurship as a scientific field

Entrepreneurship as a scientific field has grown significantly, irrespective of the measures used. In this article we raise the question: How can we understand the evolution and success of entrepreneurship as a scholarly field? In particular, we focus on the social structure of entrepreneurship scholars to explain (1) how they are becoming integrated into larger scholarly communities and (2) how they differ from the way scholars integrate within the field of innovation studies. Based on a unique database and responses from 870 entrepreneurship scholars, we demonstrate that entrepreneurship can be regarded as a phenomenon-driven field bound together by a shared communication system and social interaction rather than strong theoretical influences, i.e., a social scholarly community. We identify two broader social communities; one embedded in entrepreneurship conferences that includes a rather eclectic group of entrepreneurship scholars, and another related to entrepreneurship journals and entrepreneurship economics, characterized by a stronger domain orientation. In contrast, scholars in innovation studies tend to be more theory-driven and are bound together by their disciplinary and theoretical background, i.e., an intellectual scholarly community.     

泛酸生物合成相关酶及其基因的研究进展

泛酸是生物体内重要的代谢中间体,广泛存在于微生物和植物中。文章论述了泛酸合成途径关键酶(羟甲基转移酶、泛酸合成酶、天门冬氨酸-α-脱羧酶、酮泛解酸还原酶)及其基因的特性,并探讨其在泛酸工业生产、相关物质的检测、新型抗生素和除草剂研发等方面的应用。     

Transgenic barley with overexpressed PTrx increases aluminum resistance in roots during germination

A transgenic barley line (LSY-11-1-1) with overexpressed Phalaris coerulescens thioredoxin gene (PTrx) was employed to measure the growth, protein oxidation, cell viability, and antioxidase activity in barley roots during germination on the presence of 2 mmol/L AlCl₃ on filter paper. The results show that (1) compared with the non-transgenic barley, LSY-11-1-1 had enhanced root growth, although both were seriously inhibited after AlCl₃ treatment; (2) the degree of protein oxidation and loss of cell viability in roots of LSY-11-1-1 were much less than those in roots of non-transgenic barley, as reflected by lower contents of protein carbonyl and Evans blue uptakes in LSY-11-1-1; (3) activities of catalase (CAT), glutathione peroxidase (GPX), ascorbate peroxidase (APX), and glutathione reductase (GR) in LSY-11-1-1 root tips were generally higher than those in non-transgenic barley root tips, although these antioxidase activities gave a rise to different degrees in both LSY-11-1-1 and non-transgenic barley under aluminum stress. These results indicate that overexpressing PTrx could efficiently protect barley roots from oxidative injury by increasing antioxidase activity, thereby quenching ROS caused by AlCl₃ during germination. These properties raise the possibility that transgenic barley with overexpressed PTrx may be used to reduce the aluminum toxicity in acid soils.     

MV-代数、R0-代数、格蕴涵代数、FI-代数、BL-代数与剩余格

基于剩余格的理论与方法给出了MV-代数、R0-代数、格蕴涵代数、FI-代数、BL-代数与剩余格代数的定义的等价形式;进一步指出了各种逻辑代数的剩余格的代数本质.说明了剩余格在逻辑代数系统中的重要地位;分析了MV-代数、R0-代数、格蕴涵代数、FI-代数、BL-代数以及基础R0代数之间的相互关系,为进一步的研究奠定了必要的基础.     

School quality, child wellbeing and parents’ satisfaction

Child wellbeing at school and enjoyment of the learning environment are important economic outcomes, in particular because a growing body of research shows they are strongly linked to later educational attainments and labour market success. However, the standard working assumption in the economics of education is that parents choose schools on the basis of test-score performance, and concerns about child happiness are largely ignored. In this paper, we address this omission and investigate to what extent parents’ and children's views of their school are linked to test-score based performance, and to what extent parents’ judgements of school quality are linked to their child's happiness. To do so, we use information on stated attitudes from the Longitudinal Survey of Young People in England (LSYPE) matched to administrative records on pupil achievements in England. Our results suggest that test-score based measures of school quality tend to dominate parental satisfaction with the learning environment. However, school quality along this dimension is not strongly associated with pupil happiness and wellbeing at school.     

旅游本体的构建研究

本体是一种促使知识重用、知识共享和建模的模型.本文首先阐述了构建旅游领域本体知识库的必要性,然后利用 OWL DL 本体描述语言,通过定义本体类及其继承、类属性和关系、属性的约束以及本体实例的创建等步骤,完成了旅游领域本体的构建工作.