Two ancient rounds of polyploidy in rice genome   总被引：10，自引：0，他引：10  

Zhang Y  Xu GH  Guo XY  Fan LJ 《Journal of Zhejiang University. Science. B》2005,6(2):87-90

An ancient genome duplication (PPP1) that predates divergence ofthe cereals has recently been recognized. We report here another potentially older large-scale duplication (PPP2) event that predates monocot-dicot divergence in the genome of rice(Oryza saliva L.), as inferred from the age distribution of pairs of duplicate genes based on recent genome data for rice. Our results suggest that paleopolyploidy was widespread and played an important role in the evolution of rice.  相似文献   

校本管理下的学校教育技术资源管理     

孙祯祥  刘建新 《现代教育技术》2007,17(7):23-25

根据相关的访谈调查,笔者对当前学校教育技术资源管理存在的问题进行了分析。指出将校本管理思想引入学校教育技术资源管理是解决当前资源管理存在问题、提高资源利用效率的有效途径。  相似文献   

《离骚》与《九章》是否为同一个时期的作品——《离骚》研究系列之四     

冀凡 《黄石理工学院学报(人文社科版)》2006,23(3):47-49

探讨《离骚》与《九章》是否为同一时期的作品,旨在论证《离骚》的创作年代与历史背景,然这在汉代人的载论中是难以解决和论定的,故须从这两部作品的叙事内容的对比研究入手,加以论证其为同一时期的作品,方能从根本上而且极具说服力解决《离骚》的创作年代与历史背景的问题。当前,争论似乎不大,但敢于公然这样论说的学者并不多,这就是撰写此文的意义所在。  相似文献   

前瞻21世纪教育的发展主题     

杨帆 《辽宁师范大学学报(社会科学版)》2001,24(1):37-40

21世纪人类任重道远，教育作为协调人与自然、人与社会、人与人关系的实践活动，应该在环境教育，和平共处、共同发展、新道德建构和实施、人精神等方面承担起不可推卸的责任。  相似文献   

幻的浪漫梦的真实--论苏、辛的梦幻词     

李海帆  吴帆 《乐山师范学院学报》2005,20(3):13-16

文章首先简述宋人梦幻词的分期。提出苏、辛梦幻词的贡献在于苏、辛借鉴前人的表现手法，尤其是庄、骚、李白以来的浪漫主义手法、创造了梦幻词的诸多范式：天问式、游仙式、骚体式、俳谐式、遥相思念式、诡谲象喻式等。苏、辛梦幻词之异在于苏词清幽而旷达，辛词激越而悲壮沉郁。他们开拓了宋人梦幻词的表现领域，使宋人梦幻词的体式更加完美。  相似文献   

对心理健康教育纳入德育范畴的质疑     

范成祥 《教育科学研究》2006,(9):52-54

心理健康教育与德育的关系是近年来教育界探讨较多的问题。从研究的角度看,将心理健康教育纳入德育范畴会引发许多问题:使德育概念更加泛化,并使德育和心理健康教育难于区分;不利于心理健康教育按其自身的原则和规律科学实施;导致心理问题德育化与德育问题心理化。  相似文献   

Co(II)——双水杨醛乙二胺显色反应的研究与应用     

刘凡  刘志昌  张元勤  李晓燕 《乐山师范学院学报》2002,(4)

在 pH =5的邻苯二甲酸氢钾 -氢氧化钠的缓冲溶液中 ,钴 (II)与双水杨醛乙二胺形成黄色配合物 .该黄色配合物的λmax =380nm ,ε =5 .5x10 3L·mol- 1 ·cm- 1 ,Co(II)的质量浓度为 0～ 4 7mg 10ml时符合比尔定律 .本方法用于测定VB12药物中的钴结果良好  相似文献   

入侵检测系统研究     

肖海军  洪帆 《武汉职业技术学院学报》2002,1(3):46-49

本文介绍了网络入侵检测系统的基本功能。在对目前研究的入侵检测系统的分类、性能分析、技术分析的基础上，提出了一个针对网络入侵的综合解决方案，同时探讨了入侵检测系统的发展方向。  相似文献   

Allograftic bone marrow-derived mesenchymal stem cells transplanted into heart infarcted model of rabbit to renovate infarcted heart     

王建安  李长岭  樊友启  何红  孙勇 《浙江大学学报(A卷英文版)》2004,5(10):1279-1285

Objective: To investigate the directed transplantation of allograftic bone marrow-derived mesenchymal stem cells (MSCs) in myocardial infarcted (MI) model rabbits. Materials and Methods: Rabbits were divided into 3 groups, heart infarcted model with MSCs transplanted treatment (MSCs group, n=12), heart infarcted model with PBS injection (control group, n=20), sham operation with PBS injection (sham group, n=l 7). MSCs labelled by BrdUrd were injected into the MI area of the MSCs group. The same volume of PBS was injected into the MI area of the control group and sham group. The mortality, LVIDd, LVIDs and LVEF Of the two groups were compared 4 weeks later. Tropomyosin inhibitory component (Tn I) and BrdUrd immunohistochemistry identified the engrafted cells 4 weeks after transplantation. Result: The mortality of the MSCs group was 16.7% (2/12), and remarkably lower than the control group's mortality [35% (7/20) (P＜0.05)].Among the animals that survived for 4 weeks, the LVIDd and LVIDs of the MSCs group after operation were 1.17±0.21 cm and 0.74±0.13 cm, and remarkably lower than those of the model group, which were 1.64±0.14 cm and 1.19±0.12 cm (P＜0.05); the LVEF of the MSCs group after operation was 63±6%, and remarkably higher than that of the model group,which was 53±6% (P＜0.05). Among the 10 cases of animals that survived for 4 weeks in the MSCs group, in 8 cases (80%),the transplanted cells survived in the non MI, MI region and its periphery, and even farther away; part of them differentiated into cardiomyocytes; in 7 cases (70%), the transplanted cells participated in the formation of blood vessel tissue in the MI region. Conclusion: Transplanted allograftic MSCs can survive and differentiate into cardiomyocytes, form the blood vessels in the MI region. MSCs transplantation could improve the heart function after MI.  相似文献   

Usage patterns and social circles on Facebook among elderly people with diverse personality traits     

Fan Mo  Michal Kosinski  David Stillwell 《Educational gerontology》2018,44(4):265-275

Elderly people are exposed to information technologies to keep them in touch with younger generations. Among various technologies, social network sites (SNSs) are seldom used by the majority of elderly people. To bridge the digital divide, it is necessary to dig deeply into the minority elderly users of SNSs. This study explores usage patterns of elderly Facebook users and further investigates how their diverse characteristics influence their usage and social circles. Three findings were derived. First, a sharp digital divide on SNSs does exist, and existing elderly Facebook users are mainly the dabblers. Second, personality profiling could predict elderly people’s SNS usage behaviors. Elderly users with a high level of openness and extroversion have more friends, status updates, and group memberships, and those with a high level of conscientiousness have fewer likes and status updates. Elderly users are likely to seek insightful content on SNSs. Moreover, they may have a higher degree of emotional stability than young users when using SNSs. Third, elderly people tend to build small social circles on SNSs that “copy” the family relationship in the real world; whereas, they build large social circles with interests and hobbies that are difficult to share in the real world. Based on these results, detailed suggestions are presented for better targeting elderly people in ways that move them toward SNSs.  相似文献