肥胖男性血浆脂联素水平及影响因素

检测正常男性血浆脂联素水平,探讨其与各检测指标之间的相关性。选取正常男性96例,按体重指数（BMI）将上述两组分为2个亚组：肥胖（BMI≥25kg／m^2）组40例及体重正常（BMI〈25kg／m^2）组56例,测定空腹血浆脂联素浓度。肥胖组的血浆脂联素水平[（7．48±3．4）μg／m1]明显低于体重正常组[（10．57±4．73）μg／m1],差异有显著的统计学意义（P〈0．01）。相关分析显示血浆脂联素与体重指数（BMI）、腰围（WC）、血压（BP）、总胆固醇（TC）、血清胰岛素（FINs）、胰岛素抵抗指数（HOMA-IR）之间存在负相关,与高密度脂蛋白胆固醇（HDL-C）正相关。BMI、WC、HOMA-IR为影响血浆脂联素水平的独立因素。男性肥胖者血浆脂联素水平较体重正常者明显降低,血浆脂联素水平可能与肥胖及其相关疾病相关。     

Effects of school-based interventions on motivation towards physical activity in children and adolescents: A systematic review and meta-analysis

IntroductionAssuming that motivation is the key to initiate and sustain beneficial health behaviors, the aim of this systematic review was to analyze the effects of school-based physical activity interventions on a variety of motivational outcomes towards PA in school-aged children and adolescents.MethodsA comprehensive literature search was carried out in six electronic databases to identify randomized controlled trials and quasi-experimental trials examining the effects of PA interventions implemented during the regular school day, e.g., during physical education lessons or lunch breaks. Primary outcomes of interest were students' motivation, basic psychological needs, goal orientation, enjoyment, and motivational teaching climate in physical education. Meta-analyses were conducted for these outcomes using Comprehensive Meta-analysis software. Secondarily, intervention effects on students' PA behaviors were examined and the findings summarized narratively. Methodological quality of studies was evaluated using the Cochrane Collaboration's tool for assessing risk of bias for randomized trials; certainty of evidence on outcome level was evaluated using the GRADE approach.ResultsIn total, 57 studies carried out between 2001 and 2018 were included in this review. Sixteen individual meta-analyses were performed and revealed significant pooled effects for the outcomes enjoyment (g = 0.310), perceived autonomy (g = 0.152), identified regulation (g = 0.378), intrinsic motivation (g = 0.419), self-determination index (g = 0.672), task/mastery climate (g = 0.254), ego/performance climate (g = −0.438), autonomy supportive climate (g = 0.262), task goal orientation (g = 1.370), ego goal orientation (g = −0.188). The narrative data synthesis indicated an increase in students' PA behavior. The overall risk of bias was high across all studies and certainty of evidence of meta-analyzed outcomes ranged from very low to moderate. Moderate certainty of evidence was found for ego/performance climate and ego goal orientation. Conclusions: Meta-analyses suggest that school-based PA interventions may be effective in increasing a variety of motivational outcomes. However, the certainty of evidence was limited in the majority of outcomes. Further research is needed to identify effective intervention strategies that increase students’ motivation towards PA.     

A note on the expected value of the Rand index

Two expectations of the adjusted Rand index (ARI) are compared. It is shown that the expectation derived by Morey and Agresti (1984, Educational and Psychological Measurement, 44, 33) under the multinomial distribution to approximate the exact expectation from the hypergeometric distribution (Hubert & Arabie, 1985, Journal of Classification, 2, 193) provides a poor approximation, and, in some cases, the difference between the two expectations can increase with the sample size. Proofs concerning the minimum and maximum difference between the two expectations are provided, and it is shown through simulation that the ARI can differ significantly depending on which expectation is used. Furthermore, when compared in a hypothesis testing framework, multinomial approximation overly favours the null hypothesis.     

On the Computation of the RMSEA and CFI from the Mean-And-Variance Corrected Test Statistic with Nonnormal Data in SEM

A new type of nonnormality correction to the RMSEA has recently been developed, which has several advantages over existing corrections. In particular, the new correction adjusts the sample estimate of the RMSEA for the inflation due to nonnormality, while leaving its population value unchanged, so that established cutoff criteria can still be used to judge the degree of approximate fit. A confidence interval (CI) for the new robust RMSEA based on the mean-corrected (“Satorra-Bentler”) test statistic has also been proposed. Follow up work has provided the same type of nonnormality correction for the CFI (Brosseau-Liard & Savalei, 2014). These developments have recently been implemented in lavaan. This note has three goals: a) to show how to compute the new robust RMSEA and CFI from the mean-and-variance corrected test statistic; b) to offer a new CI for the robust RMSEA based on the mean-and-variance corrected test statistic; and c) to caution that the logic of the new nonnormality corrections to RMSEA and CFI is most appropriate for the maximum likelihood (ML) estimator, and cannot easily be generalized to the most commonly used categorical data estimators.     

CAT中结合贝叶斯方法与序贯监测程序的题库质量监控技术

Zhang(2013)提出了序贯监测程序(SMP)用以检测CAT中的题目在作答过程中是否发生泄漏。然而,该方法会出现虚报且未关注在题目泄漏后,对能力估计精度产生的影响。本研究在SMP基础上引入个人拟合指标,提出SMP_PFI方法,拟在给定的置信度上核实被SMP标记的题目是否真正泄漏,并探查SMP_PFI方法对能力估计精度与被封存题目数量关系的影响。实验结果表明：新方法能够有效降低SMP单独运行时的一类错误。通过控制CPFI值能够平衡能力估计精度与被封存题目数量之间的关系。     

异常反应模式的识别和分类

通过对Drasgow等人的个人适合指标l2公式的再分解,发现该指标也属于残差型类的指标。特别是和Tatsuoka的广义个人适合指标ξ指标具有类似的数学结构,除符号相反外,不同之处仅是公式中加权项。其次,该研究定义了任意两个异常反应对象的类似度,在此基础上试用多维标度法对异常反应模式进行再分类。结果说明分类是有效、实用的。     

中国的和尚与美国的经——关于SCI与中国学术评价机制的几点看法

以全球知名检索工具《科学引文索引》(science citation index,SCI)为代表的学术评价工具在中国受到了很多学者的质疑,从而引发了关于SCI与学术评价的论战。对这一问题的讨论和分析应当首先解决的几个问题是,我们是不是需要SCI?SCI是否适合中国的科研现实?SCI的引入对我国科研质量是否有所改善?什么能够取代SCI?这些问题的分析除了依靠逻辑推演外,更应依靠我国发表SCI论文的相关统计数据等实证资料。解决我国当前学术评价问题应从体制机制入手,把学术成果的定性评价与SCI的定量评价有机地结合起来,着力于从质和量两个方面推动我国科技进步。     

The importance of body satisfaction to physical self‐concept and body mass index in Spanish adolescents

This research examines the association between measured body mass index (BMI) and the perception of BMI by young students. Moreover, this research tests the importance of BMI and self‐concept, in order to predict body dissatisfaction in high school students. The sample consisted of 2087 individuals from different high schools in Extremadura, Spain, both males (n = 1046) and females (n = 1041), ranging in age from 15 to 17 years old (M = 15.42; SD = 0.86). Initially, participants' BMIs were assessed through anthropometry. Later, all individuals were asked about their weight and height, and their self‐reported BMI was calculated. Participants also answered a questionnaire about their perception of self‐concept, as well as completed a test about body image perception using Stunkard images. Outcomes revealed that factors concerning self‐concept and perceived BMI explained body dissatisfaction. Finally, results are discussed with the aim of improving knowledge in body dissatisfaction context.     

高血压左室肥厚的QT离散度及左室Tei指数的关系探讨

心脏是最常见的高血压损伤靶器官,首先引起左心室肥厚,然后导致心功能下降,并可导致心律失常。高血压患者中约有1/3会出现左室肥厚（LVH）,可致心血管病事件发病率增加,病死率升高,是猝死、冠心病和充血性心力衰竭的独立的、主要的危险因素和预后信号。QT间期离散度（QTd）是反映心室肌复极的不均匀性和电不稳定性预测恶性室性心...     

Preferences for female body size in Britain and the South Pacific

To assess current attitudes to body weight and shape in the South Pacific, a region characterised by relatively high levels of obesity and traditionally positive views of large bodies, 38 high socio-economic status (SES) adolescent males and 38 low SES adolescent males in Independent Samoa were asked to rate a set of images of real women for physical attractiveness. Participants in both SES settings preferred women with a slender figure, as did a comparison group in Britain, suggesting that the traditional veneration of large bodies is no longer apparent in Samoa. However, the results also showed that low SES adolescents were more likely to view overweight figures as attractive, which suggests that the veneration of slim figures may be associated with increasing SES. Implications of this finding are discussed in conclusion.