低氧训练促进大鼠骨骼肌组织血管生成的体视学研究   总被引：2，自引：0，他引：2  

郑澜  周志宏  陆爱云 《北京体育大学学报》2006,29(2):198-200,217

为了研究低氧、训练及低氧训练对骨骼肌组织血管生成的不同作用,采用3×3析因设计试验,将健康雄性SD大鼠72只,随机分为9组,采用免疫组织化学及生物体视学方法,检测骨骼肌组织中微血管密度参数的改变,分析低氧和运动训练两种不同的处理因素对骨骼肌组织微血管体积密度、表面积密度、长度密度的单独效应、主效应及交互作用.结果表明:CD34可较好显示骨骼肌组织的微血管.低氧处理及运动训练对骨骼肌组织微血管体积密度、表面积密度、长度密度的主效应有差别,低氧处理、运动训练的单独效应中以超低氧处理、低氧训练的效应最强,并且低氧处理与训练方式两因素之间具有协同交互作用.  相似文献   

More Powerful Tests of Simple Interaction Contrasts in the Two-Way Factorial Design     

Gregory R. Hancock 《Journal of Experimental Education》2017,85(1):24-35

For the two-way factorial design in analysis of variance, the current article explicates and compares three methods for controlling the Type I error rate for all possible simple interaction contrasts following a statistically significant interaction, including a proposed modification to the Bonferroni procedure that increases the power of statistical tests for deconstructing interaction effects when they are of primary substantive interest. Results indicate the general superiority of the modified Bonferroni procedure over Scheffé and Roy-type procedures, where the Bonferroni and Scheffé procedures have been modified to accommodate the logical implications of a false omnibus interaction null hypothesis. An applied example is provided and considerations for applied researchers are offered.  相似文献   

Using students’ feedback for teacher education: measurement invariance across pre-service teacher-rated and student-rated aspects of quality of teaching     

Georg Krammer  Barbara Pflanzl  Johannes Mayr 《Assessment & Evaluation in Higher Education》2019,44(4):596-609

Comparing self-perceived quality of teaching to students’ perception can be used in higher education to improve the quality of teaching of pre-service teachers in teacher education. However, comparing these measurements from different perspectives is only meaningful if the same constructs are being measured. To shed light on this comparison’s meaningfulness, we scrutinised whether aspects of quality of teaching are measured in the same way across pre-service teachers and their students by means of measurement invariance analyses. To do so, 272 pre-service teachers in teacher education rated aspects of their quality of teaching, and were rated by their 4851 students. Measurement invariance across these perspectives was tested in multilevel structural equation models. Strong measurement invariance held for two aspects of quality of teaching; for the third, one item lacked weak measurement invariance. Pre-service teachers perceived their quality of teaching lower than their students. In conclusion, aspects of quality of teaching can be compared across perspectives, and teacher education should encourage pre-service teachers to use students’ feedback as a valuable resource for improving their quality of teaching.  相似文献   

A short German Physical-Self-Concept Questionnaire for elementary school children (PSCQ-C): Factorial validity and measurement invariance across gender     

Annette Lohbeck  Maike Tietjens  Andreas Bund 《Journal of sports sciences》2017,35(17):1691-1696

Research on children’s physical self-concept (PSC) is increasingly recognised as an important field of psychology. However, there is a lack of instruments suitable for younger children at elementary school age. In the present study, a short German 21-item Physical Self-Concept-Questionnaire for children (PSCQ-C) was tested measuring seven specific facets of elementary school children’s PSC (strength, endurance, speed, flexibility, coordination, physical appearance, global sport competence). A number of 770 elementary school children aged 8–12 years completed the PSCQ-C. Results showed good psychometric properties and high reliabilities of the seven scales. Confirmatory factor analysis revealed that the presumed 7-factor model fitted the data best compared to a global 1- and 2-factor model. Also, full measurement invariance was strongly established. Correlations among the seven scales were mainly moderate. Gender differences were suggestive of developmental trends that are consistent with prior studies. These results provide support that the PSCQ-C is a confidential instrument with sound psychometric properties measuring seven specific facets of elementary school children’s PSC.  相似文献   

关于Diophantine方程x!=y1!y2!…yn!     

乐茂华 《宁德师专学报(自然科学版)》2003,15(4):339-339,355

设n是大于1的正整数,证明了如果(x,y1,y2,…,yn)是方程x!=y1!y2!…yn!的适合x＞y1≥y2≥…≥yn＞1的正整数解,则必有y1≥p以及y2＜q,其中p是不大于x的最大素数,q是大于x/2的最小系数.  相似文献   

Self‐efficacy of prospective Austrian and German primary school teachers regarding the implementation of inclusive education          下载免费PDF全文

Susanne Schwab  Frank Hellmich  Gamze Görel 《Journal of Research in Special Educational Needs》2017,17(3):205-217

This study examined the psychometric properties of the German version of the Teacher Inclusive Education Self‐Efficacy Scale (TIESES). Five hundred and nineteen teacher education students from Austria and 765 teacher education students from Germany participated in the study. Results of a multiple‐group confirmatory factor analysis (for the two countries) confirmed a single factor structure of the scale with partial scalar measurement invariance. Regression analysis showed that self‐efficacy when implementing inclusive education was explained by the motivation to deal with inclusive education during their studies, previous experience with inclusive education in internships, study interest and the country in which the students went to university.  相似文献   

基于四阶累积量的CSPRIT算法     

沈怡平  侯朝焕  马晓川 《中国科学院研究生院学报》2007,24(3):325-330

分析了基于二阶统计的CSPRIT算法在空间相关高斯噪声环境中存在的问题，提出将四阶累积量与CSPRIT算法相结合，处理一维二元相移键控信号（BPSK）和多元幅移键控信号（MASK），实现信号到达角（DOA）的估计和波束形成器的构造。与基于二阶统计的CSPRIT算法相比，基于四阶累积量的改进算法能够有效抑制空间相关的高斯噪声，提高信号估计精度。计算机仿真验证了该算法的有效性。  相似文献   

一种局部频域分析的多尺度纹理特征提取方法     

徐敏  ;张哲铭  ;周中伟 《鹭江职业大学学报》2014,(5):35-40

在局部二进制模型和多分辨率分析的基础上,提出一种基于局部频域分析的多尺度纹理特征提取方法。对纹理图像采用局部圆形邻域作为局部模板进行局部频率变换,对各频段图像实现多分辨率分析,提取多尺度下的特征向量,结合SVM算法进行分类实验。结果证明,该方法在继承了LBP对光照因素具有的稳定性的同时,具有旋转不变性特征;利用NSCT在多尺度下进行的纹理特征提取也满足尺度不变性的需要,与其他方法相比提高了分类准确率。  相似文献   

基于因子分析的巴马瑶族自治县游客满意度评价     

韦福巍  黄荣娟 《河池学院学报》2014,(1):117-120,124

构建一个包含8个一级指标和31个二级指标的游客满意度评价指标体系,通过实地随机抽样问卷调查获取巴马瑶族自治县游客满意度评价样本数据并运用SPSS软件进行因子分析,以期为民族地区县域旅游满意度评价提供实证研究参考。  相似文献   

Measurement Bias Detection Through Factor Analysis     

Willem E. Saris  Albert Satorra  William M. van der Veld 《Structural equation modeling》2013,20(4):561-582

Assessing the correctness of a structural equation model is essential to avoid drawing incorrect conclusions from empirical research. In the past, the chi-square test was recommended for assessing the correctness of the model but this test has been criticized because of its sensitivity to sample size. As a reaction, an abundance of fit indexes have been developed. The result of these developments is that structural equation modeling packages are now producing a large list of fit measures. One would think that this progression has led to a clear understanding of evaluating models with respect to model misspecifications. In this article we question the validity of approaches for model evaluation based on overall goodness-of-fit indexes. The argument against such usage is that they do not provide an adequate indication of the “size” of the model's misspecification. That is, they vary dramatically with the values of incidental parameters that are unrelated with the misspecification in the model. This is illustrated using simple but fundamental models. As an alternative method of model evaluation, we suggest using the expected parameter change in combination with the modification index (MI) and the power of the MI test.  相似文献