Reading disability in boys and girls: No evidence for a differential genetic etiology

In order to test the hypothesis that genetic influences are moreimportant as a cause of reading disability in girls than in boys,composite reading performance data from identical and fraternal twinpairs were analyzed using both concordance and multiple regressionmethods. The sample included 206 identical (99 male, 107 female), 159same-sex fraternal (90 male, 69 female), and 117 opposite-sex fraternaltwin pairs, in which at least one member of each pair had readingdifficulties. Although the difference between the concordance rates forreading disabilities in female identical and same-sex fraternal twinpairs was somewhat greater (65% for identical twins vs.32% for fraternal twins) than the difference in concordance ratesfor boys (68% vs. 39%), loglinear analysis of thesecategorical data revealed that the interaction between sex, zygosity,and concordance was not significant (p > 0.70). Moreover,the heritability of reading disability(h ² _g) estimated from regression analysisof the reading performance data in males was nearly identical to that infemales (h ² _g = 0.58 and 0.59,respectively; p > 0.90). Thus, results of this studyprovide little or no evidence for the hypothesis of greater geneticinfluence on reading difficulties in girls than in boys.     

一种自适应遗传算法对Hopfield网络权值的优化

针对Hopfield网络在求解优化问题中学习效率低,收敛速度慢,容易陷入局部最优等缺点和不足,把遗传算法同Hopfield网络结合起来,形成进化神经网络,对网络权值进行优化,并且通过对算法的讨论,说明该算法的有效性。     

一种基于遗传算法的作曲方法

本文介绍了一种基于遗传算法,以乐段为单位的作曲方法。该方法能生成具有相对完整乐思的音乐片段,并引入了音乐的风格化特征,能按照用户的情感因素产生用户所需的音乐片断。     

Genetic and Rare Disease Diagnoses: A Review of Resources for Patients and Health Care Professionals

Abstract

This article reviews genetic and rare disease resources from the National Library of Medicine and National Institutes of Health that assist patients and their families to decipher the complexity of rare and genetically related diseases. Librarians can use these resources to guide those seeking genetic information that encompasses the medical, social, psychological, and financial aspects of living with a rare disease. Physicians and healthcare professionals will find these resources helpful when assisting patients and engaging in genetic research.     

A genetic diversity comparison between captive individuals and wild individuals of Elliot’s Pheasant (Syrmaticus ellioti) using mitochondrial DNA

INTRODUCTION Genetic diversity is a major issue of conserva-tion biology recognized by the IUCN (Frankham etal., 2002). Within a population it reflects the evolu-tionary potential to adapt to novel environmentalchanges. Therefore, during the past few years, thegenetic diversity of many threatened mammals, birds,fish, insects and plants have been investigated(Frankham et al., 2002). As a direct and indirectconsequence of human actions, more and more spe-cies or populations are faci…     

新引进小黑麦的醇溶蛋白遗传多样性分析

小黑麦作为黑麦中有益基因向小麦转移的桥梁,被广泛用于普通小麦的遗传改良．为了有效利用从国际玉米小麦改良中心引进的183份小黑麦材料,利用酸性聚丙烯酰胺凝胶电泳(A-PAGE)对其醇溶蛋白的遗传多样性进行了分析,结果表明：183份材料共分离出125种不同的带型,39条迁移率不同的谱带,其中只有在ω区的三条带为所有材料共有,其余的36条带都具有多态性,多态性带数占总分离条带数的92.3%,多态性较高；并且以中国春为对照,在小黑麦材料中没有发现与中国春的醇溶蛋白相同的谱带；通过醇溶蛋白的聚类分析可将183份小黑麦材料划分为三大类．     

教学发生学原理的研究

从生物的“重演律”(“发生学”)得到启示,有:思维“重演律”(“发生学”)、智力发育的“重演律”(“发生学”)、人的认识的“重演律”(“发生学”);对学生在校学习,有教学发生学原理:在教一个科学的分支(或一个理论、一个概念)时,应该让学生重蹈(retrace)人类思想发展中的那些最关键的步子(greatstep),当然不能重蹈过去的无数个错误,而仅仅是重蹈关键性步子;其中学习的循序前进可分为三阶段:探索阶段、形式化阶段和同化阶段。     

基于遗传算法的自动频率规划

介绍了自动频率规划及用遗传算法如何进行自动频率规划的方法,并说明了对遗传算法的各个算子的设计方法及原因.提出了如何利用正交试验设计的方法来科学地设置参数.同时将正交试验方法引入通信领域中,提出了用正交试验设计方法设置参数.     

实数编码自适应基因算法在弦振动实验中的应用

在普通物理实验教学中，用实数编码自适应基因算法构建弦振动横波传播速度经验公式是一种新方法。利用基因算法拟合弦振动的实验数据，不但可以得到高精度的经验公式，加深对相关物理理论的理解，而且有利于培养学生的综合研究能力和科学探索精神。