Analysis of components of conserved “backbone sequences”among genomes of Shigella spp. strains

Difference in the genomic compositions of prokaryotes is the basis of the diversity in their biological characters. However, besides their flora-or strain-specific genes,those floras with closer relationship in the evolution also have conserved “backbone sequences”, which reveal the marks of their origin and evolution, and these “backbone sequences”are just the basis of their elementary living abilities and common biological properties. Shigella is very closely related to E. coli in the origin and evolution, and may turn out to belong to the same genus. In this study, a microarray containing E. coli K-12 whole genome and Sf301 specific ORFs is used to investigate the genomic components of four Shigella strains. The results indicate that 16%-22% K-12 ORFs sequences are not detected in the genome of Shigella strains while the genome of Shigella contains at least 2800 conserved ORFs, which compose the common “backbone sequences”.Advanced analysis indicated that the “backbone sequences”are the essential components in maintaining the normal physiological activities of intestinal bacteria. Furthermore,only 20% Sf301-specific ORFs exist in other strains simultaneously, which demonstrate the great genome heterogeneity and the genetic diversity among the strains.     

"分层"教学模式在高校体育教学俱乐部中的应用研究

目前高校体育教学俱乐部中人数较多,学生素质存在明显的个体差异,分层教学能够体现因 材施教,区别对待的教学原则,可以有效地提高学生的锻炼兴趣、发展个性、培养特长和增强体育意识。 有利于优化课堂教学及提高教学效益。     

LROTH''''S THEOREM IN DIFFERENTIAL FIELDS

In this paper, we present a constructive proof of Luroth's theorem in differential case. We also give a method to find the inversion maps for general differential rational parametric equations. As a consequence, we prove that a differential rational curve always has a set of proper parametric equations.     

我国高等体育师范教育若干问题的探析

为探讨高师如何培养适应素质教育之要求的教师,运用资料文献法、走访调查等方法,在论述高等师范教育之“师范性”的涵义和分析我国现阶段高师体育专业教育中存在的问题的基础上,提出培养适应素质教育要求之教师的若干构思;加强师范生的职业道德素质与教育理念的培养;课程改革和建设应调整专业课程结构和内容,重视未来教师体育科学教学能力的培养;实现师范性与学术性在更高水平上整合。     

高师体育教学中学生创新能力的培养

面向21世纪的核心问题是培养和造就富有创新精神和创新能力的高素质人才,作为师范教育组成部分的高师体育,要以“健康第一”的思想为先导,在教师素质提高的同时,建立以重视体育与健康教育相结合,注重培养学生体育能力及学生个性发展的教学内容和方法,为培养出健康的高素质创新型人才,全面实现素质教育创造条件。     

体育教育专业课程改革的背景分析

从高等教育的重心转移、师范教育的专业化理念以及学校体育的改革发展趋势,分析了体育教育专业课程改革的背景,认为体育教育专业的课程改革是对高等教育改革重心转移的顺应,师范教育专业化的理念对体育教育专业的课程改革提供了新的取向,学校体育的改革发展对体育教育专业的课程改革提出了直接的要求。     

Integral computation relating to rational curves based on approximate degree reduction

A new algorithm is presented for computing the volume of revolution, moment of area and centroid etc. , which are related to the integration of rational curves. In this algorithm rational curve with high degree is firstly approximated by those with lower degree through endpoint interpolation. And finally the closed form integration solution is derived for quadratic rational curve. The diminishing rate of the minimum norm of the perturbation vector needed by degree reduction is 0(2" ") when the interval is subdivided at the midpoint. Combining the subdivision with the degree reduction, we can obtain a faster convergence of integration approximation. A series of integral error bound functions which are fairly simple to compute are derived. The examples given in this paper show that this algorithm is a simple and time-saving method in computing with small tolerance.     

驾驶困倦预警系统中眼部状态识别的研究

为判断驾驶员是否处于疲劳驾驶状态,通过对人脸正面图像中的眼部状态的研究,提出了一种判断算法.首先基于灰度投影曲线和人脸几何特点提取驾驶员的眼部区域,然后利用事先提取的驾驶员睁眼时的瞳孔区域模板在该区域进行匹配,通过匹配初步判断出驾驶员是否属于疲劳驾驶.实验结果表明,该算法简单高效,在满足一定外部条件下,误判率较低.