Clones identification of Sequoia sempervirens (D. Don) Endl. in Chile by using PCR-RAPDs technique

A protocol of polymerase chain reaction-random amplified polymorphic DNAs (PCR-RAPDs) was established to analyse the gene diversity and genotype identification for clones of Sequoia sempervirens (D. Don) Endl. in Chile. Ten (out of 34) clones from introduction trial located in Voipir-Villarrica, Chile, were studied. The PCR-RAPDs technique and a modified hexadecyltrimethylammonium bromide (CTAB) protocol were used for genomic DNA extraction. The PCR tests were carried out employing 10-mer random primers. The amplification products were detected by electrophoresis in agarose gels. Forty nine polymorphic bands were obtained with the selected primers (BG04, BF07, BF12, BF13, and BF14) and were ordered according to their molecular size. The genetic similarity between samples was calculated by the Jaccard index and a dendrogram was constructed using a cluster analysis of unweighted pair group method using arithmetic averages (UPGMA). Of the primers tested, 5 (out of 60) RAPD primers were selected for their reproducibility and high polymorphism. A total of 49 polymorphic RAPD bands were detected out of 252 bands. The genetic similarity analysis demonstrates an extensive genetic variability between the tested clones and the dendrogram depicts the genetic relationships among the clones, suggesting a geographic relationship. The results indicate that the RAPD markers permitted the identification of the assayed clones, although they are derived from the same geographic origin. Project (No. CONICYT-FONDEF PROYECT D01 I 1008) supported by the National Commission of Science and Research of Chile     

学习者过渡语中英语虚拟语气标记使用研究

研究的语料是40篇英语专业二年级学生的作文。结果发现学习者对虚拟语气标记的使用在不同小句中的分布有差异,if条件句从句部分恰当S-标记的使用比例要高于其主句部分的使用比例;后者恰当S-标记的使用比例又高于“光杆”主句,且远高于其他类型从句中恰当S-标记的使用率。中国学生议论文中虚拟语气标记的使用特征说明了学习者对该标记习得的过渡语状态。     

Perceived social support from team-mates: Direct and stress-buffering effects on self-confidence

Abstract

In this study, we wished to determine whether the perceived support available from team-mates predicts levels of self-confidence. Four dimensions of support were examined: emotional, esteem, informational, and tangible. The sample consisted of 152 university athletes (74 females, 78 males) with a mean age of 20.1 years (s=1.4). Participants completed measures of perceived support, stressors, and self-confidence at the training session before an important match. Moderated hierarchical regression analyses revealed that all four dimensions of support had direct effects on self-confidence (ΔR ²=0.13–0.17, all P<0.01), with support positively predicting self-confidence. Perceived emotional (ΔR ²=0.05, P<0.05), esteem (ΔR ²=0.02, P<0.05), and informational (ΔR ²=0.03, P <0.05) support also had stress-buffering effects on self-confidence. The findings suggest that although university athletes perceived different levels of emotional, esteem, informational, and tangible support to be available from their team-mates, all four dimensions of support positively predicted self-confidence.     

谈幼儿自信心的培养

幼儿期自我意识虽已萌发,但尚处于朦胧阶段,在这个生命早期,及早观察与发现自信心形成的趋向．注意培植和塑造,防止骄傲、固执及退缩、自卑等性格的发展及不良影响的侵袭,并通过有目的有计划的教育影响,把自信心的发展引向健康积极的方向。本文试就幼儿自信心培养问题略抒管窥之见,算是参与这个问题的探讨。     

多维评价策略在初中数学分层教学中的实施探究

陶行知先生大力提倡“因材施教”,数学新课程标准也特别强调“实现不同的人在数学上得到不同的发展”。这就充分指明了我们教师在教学时要正确认识到学生知识能力等各方面的不同层次,对不同层次的学生制定不同的评价标准和要求,通过多种评价方法手段来提高不同层次学生的数学学习兴趣,使暂差生能获得学习自信,中等生不断进步,优秀生主动发展,从而让不同层次的学生都形成学习上的良性循环。     

幼儿的问题行为的教育

面对幼儿问题行为所表现出来的特征,剖析存在的原因,有针对性地进行教育,以促进幼儿身心健康地成长。     

文化自信:新时代高校思政教育发展的必然选择

文化自信是思想政治教育实现自身价值的导向,思想政治教育是高校培育大学生文化自信的实践方式。当前,在思想政治教育中,因文化解释力、文化实践力问题,以致文化自信培育的效果不明显。为解决此难题,建议高校思想政治教育提高其文化解释力、强化其文化实践力以及重视文化感召力。     

自我效能感在舞蹈训练和表演中的重要作用

良好的心理素质是舞蹈专业的学生完成训练和表演的重要保证.学生的自我效能感在舞蹈训练中有助于学生注意力的集中,在学习新的技术动作时,能够充满自信,战胜恐惧,在表演中有助于调动情绪记忆,引发激情,实现内在美与外在美的和谐统一.     

我国青少年理智情感现状调查研究

在理论推演与实践探索的基础上,我们编制了具有较好信效度的包括乐学感、自信感、成就感、探究感和好奇感五个因子的《青少年理智情感问卷》。首次对我国三类地区九大城市及其郊县的117所学校的25485名11～19岁青少年进行调查。结果表明:我国青少年理智情感总体正向积极,各因子发展不均衡,其中成就感发展最好,探究感发展最差;男生的探究感和好奇感优于女生;从小学、初中到高中,理智情感没有逐级提升,反而有下降趋势,其中乐学感和自信感下降显著,而初中一年级和高中一年级是两个明显的突降点;自信感在学校声誉、乐学感在学校位置上存在差异;理智情感及其下属的乐学感和自信感随青少年学业自评的提高而上升;师生关系良好、教师有情施教对青少年学生理智情感发展具有直接而重要的促进作用。     

克拉申的“情感过滤假说”与二语习得研究现状综述

情感因素是语言学习过程中必不可少的因素。克拉申（Krashen）的情感过滤假说揭示了语言习得中的过滤作用,文章以＂情感过滤假说＂和＂二语习得＂为关键词在CNKI中进行检索,并对搜索到的44篇期刊文章及1篇硕士论文（2002-2010）进行了概括分析。