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.     

二次曲线拟合算法的统计性能分析与改进

传统的二次曲线拟合使用标准特征值分析算法。通过统计分析技术 ,可知该技术在拟合数字二次曲线时 ,存在估计偏差大、均方误差大的缺点。其产生原因是数据噪声的有色性和自相关函数矩阵的条件数过大 ,因此白化数据噪声和正则化变换是提高曲线拟合的有效措施。这从理论上有力地支持了Hartley提出的正则化算法。通过理论分析和计算机仿真实验 ,表明了降维EVD技术固有地同时具备噪声预白化功能和数据正则化功能 ,因此它能给出均方误差相当小的无偏估计。由于它无须进行预白化变换或正则化变换 ,并把最优化过程的维数从 6降为 2 ,所以它还具有计算快速、实现简单方便的优点。     

中学体育培养学生良好个性的实验研究

通过课程及学生成绩评价系统的改革及教学方式的变化，在体育教育中对本校748名高中生进行了3年的个性培养研究。结果提示个性化体育教学有利于学生良好个性的养成和全面素质的提高。     

新世纪我国老年体育发展的困境与出路

通过对新世纪我国老年体育发展所面临的主要困境与产生困境的社会背景进行分析和讨论，指出应加大政府宏观指导的力度、完善老年体育管理体制，注重老年体育消费市场的开发，加大老年体育专业指导人员的培养力度，拓宽筹集老年体育活动资金的渠道，丰富老年体育活动内容等。     

在东方与西方之间——“春树热”的社会背景探析

村上春树的小说受欢迎的根本原因是作品深刻揭示了人性中的真善美与假恶丑,演绎了都市社会里的现代人性故事。在社会背景方面,村上的小说反映了处于相同或相似的社会进程中人们的精神状态,类似的生活体验带来的文化认同感是其小说赖以流行的基础。这种现象反映了资本主义文化扩张所具有的全球化倾向正不断消除着异文化间的差异而代之以一种普遍的跨国资本文化。     

知识经济背景下科技期刊的变革与编辑的转型

论述知识经济时代科技期刊及其生存空间的变革，为适应这种变革，科技期刊编辑应尽快转型，包括思想观念的转型，知识结构的转型，编辑职能和工作方式的转型，以及编辑社会角色的转型。