Connecting inside out: Development of the social brain in infants and toddlers with a focus on myelination as a marker of brain maturation

Early childhood is a sensitive period for learning and social skill development. The maturation of cerebral regions underlying social processing lays the foundation for later social-emotional competence. This study explored myelin changes in social brain regions and their association with changes in parent-rated social-emotional development in a cohort of 129 children (64 females, 0–36 months, 77 White). Results reveal a steep increase in myelination throughout the social brain in the first 3 years of life that is significantly associated with social-emotional development scores. These findings add knowledge to the emerging picture of social brain development by describing neural underpinnings of human social behavior. They can contribute to identifying age-/stage-appropriate early life factors in this developmental domain.     

Does modality matter? A latent profile and transition analysis of sedentary behaviours among school-aged youth: The UP&DOWN study

ABSTRACT

The aims of this study were to identify profiles of sedentary behaviour (SB) patterns, based on leisure-time self-reported SB modalities (screen, educative, social, and relaxing) and to evaluate changes in these profiles over 2 years among Spanish youth aged 8–18 years. Latent profile analysis (LPA), a data-driven analytic approach, was used to identify groups of boys and girls (n = 1553; 48% girls; mean±SD age: 12.56 ± 2.49 y) with distinct SB profiles using the SB modalities (time/d) as input variables. Latent transition analysis, an extension of LPA that uses longitudinal data, was used to analyse 2-year changes in these profiles. At baseline, four and three SB profiles were found among boys (labelled: screen, educative, social, and relaxing) and girls (labelled: screen/social, educative, and relaxing), respectively. Overall, more girls (range: 48%-67%) had the same profile over time, than boys (40%-52%). Participants with a screen or relaxing SB profile at baseline were more likely to have an educative profile after 2 years. Youth with a social and an educative SB profile at baseline were more likely to transition to profiles characterized by higher screen and social SB, respectively. Using a novel and person-centered approach, this study identified gender-specific SB profiles that were moderately stable over time.     

Digital Module 16: Longitudinal Data Analysis

In this digital ITEMS module, Dr. Jeffrey Harring and Ms. Tessa Johnson introduce the linear mixed effects (LME) model as a flexible general framework for simultaneously modeling continuous repeated measures data with a scientifically defensible function that adequately summarizes both individual change as well as the average response. The module begins with a nontechnical overview of longitudinal data analyses drawing distinctions with cross-sectional analyses in terms of research questions to be addressed. Nuances of longitudinal designs, timing of measurements, and the real possibility of missing data are then discussed. The three interconnected components of the LME model—(1) a model for individual and mean response profiles, (2) a model to characterize the covariation among the time-specific residuals, and (3) a set of models that summarize the extent that individual coefficients vary—are discussed in the context of the set of activities comprising an analysis. Finally, they demonstrate how to estimate the linear mixed effects model within an open-source environment (R). The digital module contains sample R code, diagnostic quiz questions, hands-on activities in R, curated resources, and a glossary.     

影响田径运动员心理变化的因素及其心理训练的方法

结合田径运动项目的特点,论述了影响田径运动员心理变化的因素及田径运动员的一般心理训练和赛前心理训练的方法,为田径运动员在训练和比赛中的心理训练提供参考。     

运动影响免疫系统的机制及其研究的展望

分析不同运动形式、运动强度、运动持续时间对机体免疫系统的不同影响，并归纳其作用机制，在此基础上提出了未来值得研究的问题。     

对我国女子体操运动员运动损伤原因的调查和分析

对近5年来我国女子体操运动员运动损伤的部位、损伤发生率及发生时期等进行了调查，找出了运动损伤的主要原因及损伤发生的规律和特点，提出了我国女子体操运动员今后训练预防受伤的措施。     

中日两国国民身高的比较研究

横剖面调查是体质研究中的常用方法 ,其结果能够有效的反映研究对象的体质现状。对生活在不同地域人群同时期体质状况横剖面调查结果的比较 ,可以发现它们之间在体质方面的差异。据此寻找原因 ,为增强体质提供对策。通过对同处东亚的中日两国国民的身高进行的比较研究发现 ,中国年轻男子 (从 7～ 2 9岁 )的平均身高低于日本同龄人群 ,45岁以上年龄人群高于日本同龄人群。女子身高虽然从总体上还高于日本同龄人群 ,但生活在中国南方的年轻女子的平均身高与日本同龄女子已无差异。