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1.
目的探讨自主运动调节tau蛋白激酶和tau蛋白磷酸酶的基因表达,抑制APP/PS1转基因小鼠海马tau蛋白过度磷酸化,进而改善学习记忆能力的分子机制。方法C57系APP/PS1转基因小鼠随机分为运动组(TE)与对照组(TC);C57系野生小鼠亦随机分为运动组(E)与对照组(C)。其中,TE组和E组小鼠从3月龄开始,给予16周的跑轮运动装置,TC组和C组小鼠不施加运动干预,作为相应对照组。Morris水迷宫实验检测APP/PS1转基因小鼠的空间学习记忆能力,Western Blot实验检测海马磷酸化tau蛋白(P-tau)水平,RT-PCR实验检测海马tau蛋白及tau蛋白激酶GSK-3β和CDK-5,tau蛋白磷酸酶PP2A和PP1 mRNA表达。结果(1)与TC组相比,TE组小鼠Morris水迷宫游泳潜伏期显著性降低(P<0.05),平台象限的游泳时间百分比显著性增加(P<0.05),穿越原平台位置的次数极显著性增加(P<0.01);(2)与TC组相比,TE组小鼠海马总tau蛋白mRNA表达显著下调(P<0.05),Ser202位点和Thr181位点P-tau蛋白表达均显著性下调(P<0.05);(3)与TC组相比,TE组小鼠海马tau蛋白磷酸化激酶GSK-3β(P<0.01)和CDK-5(P<0.05)mRNA表达显著性下调,tau蛋白磷酸酶PP2A(P<0.01)和PP1(P<0.01)mRNA表达极显著性下调。结论16周自主运动通过下调tau蛋白激酶表达、上调tau蛋白磷酸酶表达,抑制APP/PS1转基因小鼠海马tau蛋白的过度磷酸化,进而促进海马神经细胞功能,改善转基因小鼠学习记忆。说明自主运动可通过调节脑的分子生物学机制,促进认知功能的改善和提升,预防和缓解阿尔茨海默病。 相似文献
2.
为了避免股票市场中因子之间复杂非线性关系引起的多因子选股模型过拟合现象,基于因子偏离度对股票因子数据进行分析,筛选影响股票收益率的有效因子,通过梯度提升树对股票影响因子的权值进行不断调整和分析,建立一个DEV-GBDT量化选股模型,再根据基于因子偏离度的GBDT多因子选股模型的预测结果进行模拟交易,以沪深300指数成分股2010年1月1日—2019年7月31日数据为例进行实证分析。实验结果表明,DEV-GBDT选股模型的年化收益率达26.14%,比传统GBDT选股模型提高8.61%。基于因子偏离度的GBDT多因子选股模型能有效识别股市影响因子,提高股票预测准确度,帮助投资者获得超额收益。 相似文献
3.
This article explores the social determinants of adolescents’ access to education during the COVID-19 pandemic in three diverse urban contexts in Bangladesh, Ethiopia and Jordan. It provides novel empirical data from the Gender and Adolescence: Global Evidence longitudinal study, drawing on phone surveys (4441), qualitative interviews with adolescents aged 12–19 years (500), and key informant interviews conducted between April and October 2020. Findings highlight that the pandemic is compounding pre-existing vulnerabilities to educational disadvantage, and that gender, poverty and disability are intersecting to deepen social inequalities. The paper concludes by reflecting on policy implications for inclusive distance education in emergencies. 相似文献
4.
Feedback can play a vital role in fostering teacher self-efficacy. Social comparisons and feedback valence (positive vs. negative feedback) are assumed to have a large impact on self-efficacy. Therefore, how pre-service teachers perceive social comparisons and feedback valence in peer feedback and the extent to which pre-service teachers (bachelor/master students) and teacher trainers incorporate comments that can have an impact on self-efficacy into their peer feedback merit investigation. Two studies were conducted. The first showed that peer feedback consisting of a social comparison and with positive feedback valence resulted in greater willingness to improve and positive affect. The second study revealed that teacher trainers’ feedback was more specific, whereas bachelor students’ feedback contained more social comparisons than did master students’ and teacher trainers’. Future research and practical implications are discussed. 相似文献
5.
is a popular item fit index that is available in commercial software packages such as flexMIRT. However, no research has systematically examined the performance of for detecting item misfit within the context of the multidimensional graded response model (MGRM). The primary goal of this study was to evaluate the performance of under two practical misfit scenarios: first, all items are misfitting due to model misspecification, and second, a small subset of items violate the underlying assumptions of the MGRM. Simulation studies showed that caution should be exercised when reporting item fit results of polytomous items using within the context of the MGRM, because of its inflated false positive rates (FPRs), especially with a small sample size and a long test. performed well when detecting overall model misfit as well as item misfit for a small subset of items when the ordinality assumption was violated. However, under a number of conditions of model misspecification or items violating the homogeneous discrimination assumption, even though true positive rates (TPRs) of were high when a small sample size was coupled with a long test, the inflated FPRs were generally directly related to increasing TPRs. There was also a suggestion that performance of was affected by the magnitude of misfit within an item. There was no evidence that FPRs for fitting items were exacerbated by the presence of a small percentage of misfitting items among them. 相似文献
6.
1+X证书制度是提高技术技能人才培养质量的重要举措,是深化复合型技术技能人才培养培训模式和评价模式改革的重要途径,是探索构建国家资历框架的基础性工程。1+X证书制度涉及多方利益主体,事关人才培养体系重构。基于1+X证书制度的实施,提出“四方联动、五链耦合”人才培养机制。所谓“四方联动”,是指政府、学校、企业、培训评价组织四方高度协同、实时联动;所谓“五链耦合”,是指基于1+X证书重构教学流程、再造课程结构,人才培养体系中的智慧型岗位、模块化课程、结构化团队、项目化教学、复合型人才五个环节高度耦合、环环相扣,形成复合型技术技能人才培养新机制,以期为中国特色高水平高职学校建设提供参考借鉴。 相似文献
7.
Charlotte L. Bagnall Claire L. Fox Yvonne Skipper 《Journal of Research in Special Educational Needs》2021,21(2):156-167
Primary–secondary school transition encompasses multiple social, academic and environmental changes which can negatively impact children’s emotional well-being. Children with Social, Emotional and Mental Health difficulties (SEMH) are believed to be especially vulnerable during this time. However, the voices of children with SEMH are heavily underrepresented in this field within practice and research. The present case study examined how children with SEMH difficulties within one special school experience primary–secondary school transition and how they are supported, in order to make recommendations to improve this period. The case study was qualitative and longitudinal, conducted over 18-months and methodologies included ethnographic observations, child photo-elicitation focus groups (with 11 Year 6 children) and three adult interviews. Findings demonstrated that over primary–secondary school transition children with SEMH difficulties (a) negotiate significant structural changes in support (often unanticipated) and (b) need to feel a sense of safety and belonging. To manage this effectively, transition provision for children with SEMH difficulties needs to consider their short-term emotional well-being whilst still in primary school, in addition to their long-term well-being looking ahead to secondary school. Greater collaboration and communication across schools and stakeholders can help ensure children receive continuity in standards and support. 相似文献
8.
王明前 《苏州教育学院学报》2021,(1)
晋绥边区党和政府把农业作为战时经济的主体重点加以经营,在恢复正常生产的基础上,进一步挖掘农业生产潜力。边区党和政府积极鼓励垦荒事业,专门制定法令进行政策扶持,通过经济杠杆作用奖励发动民间力量兴办水利事业。同时,帮助农民提高农业生产技术,奖励某些特产的种植,增加农业的综合效益。畜牧业也得到大力扶持。边区粮政是农业生产成就的具体实现,也是边区财政制度的重要组成。边区党和政府严格执行粮食财政的预决算制度,规范粮食的支出程序,逐步完善粮食财政制度,并采取政府赈济和民间借粮相结合的办法,调剂粮食资源。 相似文献
9.
许波 《宁波职业技术学院学报》2021,(2):27-32
技能竞赛是培养高职学生创业能力的重要途径,技能竞赛可以分为创业竞赛和职业能力竞赛。通过对河源职业技术学院的183份有效样本数据进行因子分析,筛选出三个主因子,分别从专业能力、管理能力和成长潜力维度对高职学生创业能力产生影响,然后以创业竞赛和职业技能竞赛为自变量对三个主因子进行回归分析。研究发现创业竞赛对专业能力和管理能力有显著影响,职业技能竞赛对成长潜力有显著影响。培养高职学生创业能力需要进行多角度创业实践,积极参与创业竞赛,完善创业教育体系。 相似文献
10.