High genetic diversity in population of <Emphasis Type="Italic">Lepturichthys fimbriata</Emphasis> from the Yangtze River revealed by microsatellite DNA analysis

Lepturichthys fimbriata (Günther) is one of the benthic and rock-attached fish species that is typically found in torrential flows of the upper reaches of the Yangtze River in China. Several dams in the Yangtze River (the Ertan Dam, the Three Gorges Dam, the Gezhouba Dam, the Xiluodu Dam and the Xiangjiaba Dam (the latter two dams are under construction)) may have significant effects on the habitat and spawning behaviors of L. fimbriata, and could ultimately threaten the survival of this fish. We studied the population genetic diversity of L. fimbriata samples collected at three sites within the Yangtze River and one of its tributaries, the Yalong River. Genetic diversity patterns were determined by analyzing genetic data from 14 polymorphic microsatellite loci isolated in Jinshaia sinensis (Sauvage et Dabry). A high genetic diversity among these L. fimbriata local populations was indicat- ed by the number of microsatellite alleles (A) and the expected heterozygosity. No reductions of genetic diversity in any L. fimbriata population were observed. However, significant population differentiations were observed among three local populations by pairwise comparisons (P<0.001). We deduced that L. fimbriata local populations were not small ones. In addition, the habitat behaviors of rock-attachment and possible residence of L. fimbriata could account for the genetic differences found in local populations.     

一种多核配合物稳定常数的简便测定方法

提出了一种测定多核配合物累积稳定常数的简便方法。即在保持配体A自由配体浓度恒定的条件下,逐渐滴定加入金属离子M,将金属离子总浓度对数值lgCM对自由金属离子浓度负对数pM作一阶偏微分图,找出偏微分值等于被测多核配合物MaAb中金属离子M的配位数负值-a时对应的pM和lgCM;应用公式:lgβMaAb=lgCM+apMr=-a+bpA-lga得到MaAb累积稳定常数对数值lgβMaAb的初值,再将初值代入公式:lgβMaAb=lgCM+apMr=-a+bpA-lga+lgMaAb,max得到新的lgβMaAb值,逐步迭代至两次结果相等即为最后计算结果。两种多核配合物体系被用于计算,计算结果与真实验值一致。     

Human Culture and Science: Equality and Inequality as Foundations of Scientific Thought

We argue that the concepts of `human equality' and `inequality' play an important role in the structure of science and philosophy. When the value of `human inequality' predominates, scientific categories are formed in accordance with the principle of `hierarchical differentiation' and concepts remain closely tied to the objects they are referring to. Following Mirowski we define this as the `anthropometric stage' of human thought and development. Contrary, Mirowski's `syndetic stage' refers to societies where the value of `human equality' prevails. Here concepts appear that are universally applicable. However, because of their conventional nature these concepts cannot be `grasped' any longer by human intuition. Between the `anthropometric' and `syndetic' stages, a `lineamentric stage' appears, a period of transition from `human equality' to `human inequality'. Being both a bridge and gap between the two other stages, the `lineamentric' stage contains many contradictions between an `abstract attitude' and `concrete categories'. In this paper we examine the anthropometric, lineamentric and syndetic stages and discuss several examples taken from philosophy, logic, mathematics and physics.     

离体培养西葫芦子叶花芽分化最佳龄期的选择

为研究花芽分化的机理，选择西葫芦种苗在一定真叶期时的子叶为外植体，培养于附加KT1.0mg/L MS培养基中，其花芽分化率可达60%；分析葫芦种苗在一片真叶期时子叶内源激素和多胺含量，发现子叶内源GA1/3含量偏低，而ZRs含量剧增，同时ZRs/GA1/3、ABA/GA1/3、Spd/Put、Spm/Put比值较高，这些内源因素有利于西葫芦子叶花芽分化。     

基于Excel VBA的高校考试质量分析模板

为了解决考试质量分析过程中出现的工作效率低、操作难度高、质量分析不够科学等问题,基于Excel对象模型和VBA语言编制了一个考试质量分析模板,通过试题的难度和区分度、考试成绩的正态相关度等指标对考试质量进行分析评价,结合数据分析与问卷调查的方法,自动形成评价意见,并将处理和分析结果统一导出为Word格式的报表.该模板可协助高校教师进行考试成绩处理和质量分析,提高工作效率.     

Effect of kinase-negativeEGFR gene on differentiation of embryonic germ cell line EG4

EG4 cells derived from primordial germ cells (PGCs) of 10.5 d post coitum 129/svJ mouse embryos can be used as a model system for in vitro differentiation study due to their pluripotential development ability. EG4 cell lines with stable expression of kinase-negative EGFR cDNA, designated EG4-EGFR^d, were generated by gene transfection. We found that: (ⅰ) EG4-EGFR^d cells share the similar morphology and growing character with wildtype cells that can maintain undifferentiated state in long term culture. (ⅱ) Treatment of EG4 cells with RA resulted in differentiation of adipocyte, while in mutant clones of EG4-EGFR^d, adipocytes were sparse or absent under the same condition, indicating the role of EGFR expressed during adipocyte development. (ⅲ) Histological analysis showed that predominant tissues in teratocarcinomas derived from EG4-EGFR^d cells and wildtype cells are different. A large amount of undifferentiated cells was present in those coming from mutant cell clones. In addition some cardiac and skeletal muscles are prominently differentiated cell types. EG4 wildtype cells produced multiple differentiated cell types of three primary germ layers such as cartilage, epithelia and neural tube. These studies suggested that EGFR-dependent differentiation was inhibited in kinase-negative EG4 cells.     

体液免疫中IL-2/IL-2R整合CD4+T细胞信号形成Tfh

总结了参与Th细胞各种亚型分化的主要信号途径,并对IL-2/IL-2R信号影响Th亚型分化的分子机制进行了深入探讨.IL-2/IL-2R信号可能作为一种调节分子可以整合CD4+T细胞在免疫应答中的多种信号,从而将T细胞打造成一种更为成熟的形式,然后迁移至B淋巴滤泡和生发中心处辅助B细胞产生抗体和形成记忆B细胞.据此,推测这种成熟形式的Th就是Tfh,并提出了Tfh细胞产生及功能发挥的新模型,以正确认识Tfh在体液免疫中的关键作用.     

城镇化进程中农村社会分化问题探究

从城镇化进程角度分析了我国现阶段各区域农村社会分化的现状和特点,主要表现为社会两极分化严重、农村社会不稳定、农村保障制度不完善等,以致于家庭关系不和谐,子女教育不善,各阶层间的矛盾突出,群体性事件频发。对导致我国农村社会分化的原因进行了研究和分析,提出通过协调农村各阶层利益的发展、关注弱势群体的利益、加强农村社区文化建设以及调动各阶层的参与主动性等建议,以此共建社会主义和谐社会,加快我国城镇化的进程。     

傅里叶变换中时域微积分性质的应用

傅里叶变换(Fourier Transform)是信号与系统分析中的重要数学工具,而傅里叶变换的性质经常用于求解信号的频谱函数。在具体的应用过程中,由于对性质的应用条件把握不准,会忽略一些细节问题造成计算错误。从实例出发,对时域微积分性质的应用做了更详尽的分析和探讨。     

搜索引擎的差异化发展

分析了搜索引擎的现状,指出搜索引擎已经进入了差异化发展的时代。