论情势变更原则

情势变更原则是现代民法领域的重要理论问题。本文从情势变更原则的概念出发,考察其发展、演变,分析和阐明了情势变更原则的适用条件和法律效力,论述了在我国合同法中确立情势变更原则的必要性。     

Use of multitrait-multimethod modelling to validate actual and preferred forms of the What Is Happening In this Class? (WIHIC) questionnaire

This article describes the validation of scores on actual and preferred forms of the What Is Happening In this Class? (WIHIC). The WIHIC is a 56-item instrument that assesses seven classroom environment dimensions: Student Cohesiveness, Teacher Support, Involvement, Investigation, Task Orientation, Cooperation and Equity. A sample of 978 secondary school students from Australia responded to actual and preferred forms of the WIHIC. Separate confirmatory factor analyses for the actual and preferred forms supported the seven-scale a priori structure of the instrument. Fit statistics indicated a good fit of the models to the data. The use of multitrait-multimethod modelling with the seven scales as traits and the two forms of the instrument as methods supported the WIHIC’s construct validity. This research has provided strong evidence of the sound psychometric properties of the WIHIC.     

Meta-analysis of faculty's teaching effectiveness: Student evaluation of teaching ratings and student learning are not related

Student evaluation of teaching (SET) ratings are used to evaluate faculty's teaching effectiveness based on a widespread belief that students learn more from highly rated professors. The key evidence cited in support of this belief are meta-analyses of multisection studies showing small-to-moderate correlations between SET ratings and student achievement (e.g., Cohen, 1980, Cohen, 1981; Feldman, 1989). We re-analyzed previously published meta-analyses of the multisection studies and found that their findings were an artifact of small sample sized studies and publication bias. Whereas the small sample sized studies showed large and moderate correlation, the large sample sized studies showed no or only minimal correlation between SET ratings and learning. Our up-to-date meta-analysis of all multisection studies revealed no significant correlations between the SET ratings and learning. These findings suggest that institutions focused on student learning and career success may want to abandon SET ratings as a measure of faculty's teaching effectiveness.     

Assessment of teacher competence using video portfolios: Reliability, construct validity, and consequential validity

The richness and complexity of video portfolios endanger both the reliability and validity of the assessment of teacher competencies. In a post-graduate teacher education program, the assessment of video portfolios was evaluated for its reliability, construct validity, and consequential validity. Although video portfolio facilitated a reliable and valid assessment of teacher competencies, procedures to improve assessment quality were also revealed and are therefore discussed: more explicit grounding of assessment results in the data, peer debriefing, prolonged engagement with the assessment data, cross-checking to find confirmatory or counter examples.     

美国《员工招聘程序统一指南》简介及对我国公务员考录体系改革的启示

《员工招聘统一指南》是在美国各级、各类组织进行人事选拔时必须遵守的指导性文件。它有效地保障了美国各级、各类组织人事选拔的公平性、有效性,对我国公务员考录统一指导性文件的制定具有参考和借鉴意义。     

2009年NMET阅读理解试题内容效度分析

文章依据高中英语教学大纲、课程标准和考试大纲,结合Bachman＆Palmer（1996）的任务特征框架,从语篇输入、预期回答和题项设计三个方面对2009年高考英语全国卷与各省市自主命题卷（NMET）（19套）阅读理解试题的内容效度进行分析。其结果表明,2009年NMET阅读理解试题总体符合两纲要求,并呈现体裁多样,覆盖面广,但篇章分布不均衡;文章题材涉及范围广,其中社会与文化类所占比例最大,其次是科普;阅读量多数符合大纲要求,但个别卷篇阅读量与大纲要求相比偏高或偏低;生词量符合大纲要求;篇章难度以中等题为主,但有些篇章选择缺乏梯度;考查技能全面,但集中于对理解文章具体信息的考查;题项设计合理,但还存在一些问题等特征。据此作者尝试为今后NMET阅读理解试题命制的改进提出意见与建议。     

高考效度问题研究

效度是评价高考选才有效性的指标。测算高考效度的最佳效标是大学学业总成绩,评价高考效度应当基于它提高高校录取决策质量的程度。实证研究认为,高考有效地发挥了为普通高等学校选择合适生源的作用,高考选才的有效性体现了由"精英"到"大众"转变的特点,就具体科目而言,英语科目选才的有效性最好,而综合科目选才的有效性最差。提高高考效度需要从命题、施考、阅卷、分数使用等因素入手,而制约高考效度提高的实践条件主要有考试理论与技术、考试模式、考试成本、高校招生录取制度及高校内部管理制度、舆论环境、利益的调整。     

Construct validation of the Behavior and Instructional Management Scale

Beliefs related to classroom management vary among teachers and play an important role in classrooms. Despite the importance of this construct, valid measures have proven difficult to develop. This study evaluated the psychometric properties of the Behavior and Instructional Management Scale (BIMS), a short but valid measure of teachers' approaches to behavioral and instructional management. Results revealed a two-factor solution that possessed a good model fit, with large estimated factor loadings using confirmatory factor analysis. Evidence of validity was obtained with the Ohio State Teacher Efficacy Scale. Internal consistency for both subscales was adequate. Implications for future research are discussed.     

Production of carotenoid sarcinaxanthin by Kocuria palustris isolated from Northeastern Brazil Caatinga soil and their antioxidant and photoprotective activities

BackgroundThis study aimed to produce carotenoids of two bacterial strains obtained and isolated from Caatinga soil in Northeastern Brazil and to evaluate their antioxidant and photoprotective activities. The morphological identification of bacteria was performed by Gram staining and molecularly confirmed through the 16S rRNA gene. The production of carotenoids was performed on two 2³ factorial designs to analyze the influence of independent variables (temperature range, luminosity, agitation, spiral presence, and bacterial isolate type) for maximum carotenoid yield. The selected condition has been transferred to a bioreactor (10L). The identification of carotenoids was performed by liquid chromatography (HPLC) and mass spectrometry (LC-MS). Antioxidant activity was determined by inhibiting the β-carotene/linoleic acid system and the effectiveness as sunscreen was measured through its sun protection factor (SPF).ResultsThe results revealed that the isolates FT-7.22 and FT-5.12 were identified as Kocuria palustris; producers of a rare C50 carotenoid sarcinaxanthin. This is the first report on the production of carotenoids by this species from the Caatinga Domain. The pigment that was obtained from the Tryptic Soy Broth (TSB) medium in the best conditions of the factorial designs (increased agitation, aeration, and light exposure) exhibited a significant increase in the carotenoid production. The isolated FT-7.22 reached a higher sarcinaxanthin concentration (112,480 μg/L), and it exhibited promising antioxidant (76.53 ± 0.09%) and photoprotective activities (SPF = 9.36 ± 0.52).ConclusionsThis study demonstrated the ability of K. palustris to produce carotenoid sarcinaxanthin with antioxidant and photoprotective activities so that it can be applied in cosmetic formulations.How to cite: Mendes-Silva TCD, Vidal EE, de Souza RFR, et al. Production of carotenoid sarcinaxanthin by Kocuria palustris isolated from Northeastern Brazil Caatinga soil and their antioxidant and photoprotective activities. Electron J Biotechnol 2021;53. https://doi.org/10.1016/j.ejbt.2021.05.004     

《顶岗实习生职业压力量表》的编制

本研究的目的是为了编制高职学生顶岗实习心理压力源量表。通过开放性问卷调查、对大学生心理咨询个案的分析和对高校实习指导教师、企业实习管理人员及实习生的访谈,确定了条目,通过探索性因素分析进行项目的筛选和因子的提取,再用另一半被试进行了验证性因素分析。确定顶岗实习生压力源量表由28个条目组成,7因素结构。源量表的信效度基本符合心理测量学的要求。