广告效果下降原因及其对策分析

广告效果下降是当前广告业的一种普遍现象，成为困扰广告商和广告公司的一个难题。如何创制更有新意、更有效果的广告，使广告传递的商品信息让受众注意、形成记忆、产生行动是广告人努力的方向。本文通过时广告效果下降原因的剖析，提出了相应的对策和措施。     

关于学习控制的定量分析

本文根据著名教育技术学家瑞奇鲁斯 (C .M .Reigeluth)的影响学习控制的主要因素 ,将其进行量化处理 ,并设计出相应的计算公式 ,然后根据学习控制定量分析调查结果 ,计算学习控制的量化数据 ,利用定量分析的方法 ,指导教师制定和实施相应的教学策略。     

Development of a chemically defined medium for Planctopirus limnophila to increase biomass production

BackgroundPlanctomycetes is a phylum of biofilm-forming bacteria with numerous biosynthetic gene clusters, offering a promising source of new bioactive secondary metabolites. However, the current generation of chemically defined media achieves only low biomass yields, hindering research on these species. We therefore developed a chemically defined medium for the model organism Planctopirus limnophila to increase biomass production.ResultsWe found that P. limnophila grows best with a 10 mM sodium phosphate buffer. The replacement of complex nitrogen sources with defined amino acid solutions did not inhibit growth. Screening for vitamin requirements revealed that only cyanocobalamin (B12) is needed for growth. We used response surface methodology to optimize the medium, resulting in concentrations of 10 g/L glucose, 34 mL/L Hutner’s basal salts, 23.18 mM KNO₃, 2.318 mM NH₄Cl and 0.02 mg/L cyanocobalamin. The analysis of amino acid consumption allowed us to develop a customized amino acid solution lacking six of the amino acids present in Aminoplasmal 10%. Fed-batch cultivation in a bioreactor using the optimized medium achieved a final ΔOD₆₀₀ of 46.8 ± 0.5 after 108 h, corresponding to a cell dry weight of 13.6 ± 0.7 g/L.ConclusionsThe optimized chemically defined medium allowed us to produce larger amounts of biomass more quickly than reported in earlier studies. Further research should focus on triggering P. limnophila biofilm formation to activate the gene clusters responsible for secondary metabolism.How to cite: Kruppa OC, Gerlach D, Fan R, et al. Development of a chemically defined medium for Planctopirus limnophila to increase biomass production. Electron J Biotechnol 2021;54. https://doi.org/10.1016/j.ejbt.2021.09.002.     

Can a non-Muslim Mass Shooter be a “Terrorist”?: A Comparative Content Analysis of the Las Vegas and Orlando Shootings

ABSTRACT

This study used the 2017 Las Vegas and 2016 Orlando mass shootings as case studies to explore alleged double standards in reporting of events featuring Muslim and non-Muslim mass perpetrators of violence. The study used framing theory and content analysis to examine Los Angeles Times and New York Times coverage of the shootings during the one week immediately following each event. Findings are consistent with previous literature and the researchers’ expectations. The Orlando shooting, carried out by a Muslim, was allotted more coverage despite the fact that it produced nine fewer fatalities than the Las Vegas shooting, perpetrated by a white non-Muslim. The analysis also showed that the examined newspapers were more likely to employ a “terrorism” frame in their coverage of the Orlando shooting than in their coverage of the Las Vegas shooting; link the Orlando mass shooting with the global war on terrorism; and to humanize Stephen Paddock, the white perpetrator of the Las Vegas shooting. Framing differences found in this study may contribute to downplaying the threat of white male gun violence, and to reinforcing fears of Islam and Muslims.     

Coordinating multiple representations of polynomials: What do patterns in students' solution strategies reveal?

We investigate the strategies used by 64 advanced secondary mathematics students to identify whether a given pair of polynomial representations (graphs, tables, or equations) corresponded to the same function on an assessment of coordinating representations. Participants also completed assessments of domain-related knowledge and background skills. Cluster analysis of strategies by representation pair revealed patterns in the participants' strategy use. Two clusters were identifiable on tasks that required matching equations to graphs and graphs to tables. We identified overlap between these two clusters, suggesting that while the representation pair influenced strategy choice, there was also a general distinction between students who used more and less sophisticated strategies. However, students who used more sophisticated coordination strategies were similar to the others on measures of domain-specific knowledge or background skills. We consider implications for future investigations testing interventions to promote coordinating representations.     

女大学生瑜伽练习中呼吸运用的现状与分析

在高校体育选修课程中,瑜伽通过调吸调身调心,达到身心灵合一的境界,受到众多女大学生的欢迎和喜爱,而在教学过程中,学生普遍存在一些有关呼吸方面的困惑。针对这一问题的现状进行简单分析,提出解决方案,希望对以后的教学工作有一定的指导意义。     

关于城乡结合部中小学生心理困境现状的调查分析——以河南省周口市为例

城乡结合部中小学生面临的心理困境有日趋增多的趋势。困境产生的原因主要来自社会、学校、家庭和学生个人四个方面。只有采取强化心理健康教育工作、提高教师心理健康教育能力、构建心理健康教育体系等对策,才能使中小学生走出心理困境,实现全面发展。     

Formative Assessment: A Meta‐Analysis and a Call for Research

An effect size of about .70 (or .40–.70) is often claimed for the efficacy of formative assessment, but is not supported by the existing research base. More than 300 studies that appeared to address the efficacy of formative assessment in grades K‐12 were reviewed. Many of the studies had severely flawed research designs yielding uninterpretable results. Only 13 of the studies provided sufficient information to calculate relevant effect sizes. A total of 42 independent effect sizes were available. The median observed effect size was .25. Using a random effects model, a weighted mean effect size of .20 was calculated. Moderator analyses suggested that formative assessment might be more effective in English language arts (ELA) than in mathematics or science, with estimated effect sizes of .32, .17, and .09, respectively. Two types of implementation of formative assessment, one based on professional development and the other on the use of computer‐based formative systems, appeared to be more effective than other approaches, yielding mean effect size of .30 and .28, respectively. Given the wide use and potential efficacy of good formative assessment practices, the paucity of the current research base is problematic. A call for more high‐quality studies is issued.     

竞技武术套路运动员力量素质的训练措施分析

在现代竞技武术比赛中,超强的力量素质对创造优异的运动成绩起着重要作用。本文通过文献资料法、逻辑分析法等方法,针对竞技武术套路的运动特点指导和制定科学合理的力量素质训练方法,旨在使竞技武术套路训练走向更加科学化和规范化的道路,以期促进我国武术事业的发展。     

基础教育英语语法教学价值分析

结合西方应用语言学和语言习得研究的进展,分析中国英语语法教学的现状,我们可以发现国内对语法教学价值判断的失当源于极性思维、盲从心理和实践精神的缺位;语法教学的必要性受多种复杂变量影响而处于一种分层次的连续状态,因此不是教与不教的问题而是更适合谁的问题;立足实践第一的原则才能客观看待语法教学的价值。