Model Implied Instrumental Variables (MIIVs): An Alternative Orientation to Structural Equation Modeling

Few dispute that our models are approximations to reality. Yet when it comes to structural equation models (SEMs), we use estimators that assume true models (e.g. maximum likelihood) and that can create biased estimates when the model is inexact. This article presents an overview of the Model Implied Instrumental Variable (MIIV) approach to SEMs from Bollen (1996). The MIIV estimator using Two Stage Least Squares (2SLS), MIIV-2SLS, has greater robustness to structural misspecifications than system wide estimators. In addition, the MIIV-2SLS estimator is asymptotically distribution free. Furthermore, MIIV-2SLS has equation-based overidentification tests that can help pinpoint misspecifications. Beyond these features, the MIIV approach has other desirable qualities. MIIV methods apply to higher order factor analyses, categorical measures, growth curve models, dynamic factor analysis, and nonlinear latent variables. Finally, MIIV-2SLS permits researchers to estimate and test only the latent variable model or any other subset of equations. In addition, other MIIV estimators beyond 2SLS are available. Despite these promising features, research is needed to better understand its performance under a variety of conditions that represent empirical applications. Empirical and simulation examples in the article illustrate the MIIV orientation to SEMs and highlight an R package MIIVsem that implements MIIV-2SLS.     

Changes in step time variability,not changes in step length and width,are associated with lower-trunk sway during dual-task gait in older adults

Individuals are exposed to repetitive dual-task-like situations in daily life, particularly while walking, and falls among community-dwelling older adults typically occur in such situations. Thus, understanding how individuals adapt their walking-related motion under dual-task conditions is of clinical importance. The present study was conducted to investigate the association between dual-task-related changes (DT-changes) in lower-limb gait parameters and DT-changes in lower-trunk sway. We hypothesized that DT-changes in both spatial- and temporal-lower-limb gait parameters would be associated with DT-changes in lower-trunk sway. Participants were older adults aged > 60 years who lived independently in communities (n = 43, 73.7 [6.1] years old), and younger adults (n = 28, 22.7 [5.1] years old). Participants were asked to walk while performing an additional cognitive task, or with no additional task. During walking, lower-limb gait parameters (step time, step length and width) and lower-trunk sway were measured using a photoelectric cell system and inertial sensors. In older adults, DT-changes in step time variability was significantly associated with DT-changes in lower-trunk sway (standard beta = 0.683, p = 0.003), and DT-changes in lower-trunk sway variability (standard beta = 0.493, p = 0.029). In younger adults, DT-changes in step width were significantly associated with DT-changes in lower-trunk sway (standard beta = 0.395, p = 0.041). The current results partially supported our hypotheses. The association between DT-changes in lower limb and DT-changes in lower-trunk sway varied according to age group.     

Nonlinear approach to study the acute effects of static and dynamic stretching on local dynamic stability in lower extremity joint kinematics and muscular activity during pedalling

Researchers have reported contradictory results on the effect of static and dynamic stretching on subsequent performance. Due to the importance of performance through static and dynamic stretching, the aim of this study is to investigate the acute effects of static and dynamic stretching protocols on local dynamic stability in lower extremity joint kinematics and muscular activities during pedalling using a nonlinear dynamics approach. Using a randomised crossover trial design, fifteen active males participated voluntarily in this research (mass: 69.02 ± 10.52 kg, height: 174.00 ± 6.74 cm, and age: 21.20 ± 1.47 years) and completed a pedalling trial in situations of without stretching (WS), after static (SS), and dynamic stretching (DS) of lower extremity. The lower extremity joint angles in the sagittal plane and the electrical activity of soleus, gastrocnemius medialis, tibialis anterior, vastus medialis, biceps femoris, and rectus femoris muscles were collected during 30 pedalling cycles at 70 rates per minute. The results of the repeated measure ANOVA indicated that the knee and ankle angle largest LyE was significantly lower in DS compared to WS and SS. The largest LyE in muscle activity is also significantly lower for all the muscles after DS compared to WS and SS (P ≤ 0.05). Regarding the positive effects of DS on the joints and the muscle activity local dynamic stability, it is suggested to use DS than SS in the warm-up program before repetitive activities like pedalling.     

主观概率判断的支持理论

支持理论是一个关于主观概率判断的非外延性理论,它有以下几个主要观点：1.主观概率判断受到描述的影响,具有描述的依赖性;2.主观概率判断的结果是判断者对中心假设的相对支持的反映;3.主观概率在二元判断中表现出二元互补性,在多元判断中表现出次可加性;4.主观概率判断存在分解效应和促进效应     

规范化治疗体系对抑郁症治疗依从性的干预研究探讨

抑郁症的药物治疗是一个长期的过程,因此治疗依从性极其重要,然而,因疾病特点、药物、医患等多方面原因,导致治疗依从性较差,如何提高治疗依从性成为备受关注的问题。国内外相关研究较多,其中系统规范的随诊模式,抑郁症及药物知识的教育,心理治疗及对家庭成员相关知识的教育干预等均被证实确实有效。本文就各种干预方法进行探讨,以期确立系统规范的随诊、治疗体系,提高治疗依从性。     

中小学教师学习调节模式的结构与测量

目的：探索中小学教师学习调节模式的结构,并编制教师学习调节模式问卷。方法：根据访谈研究的结果,在参照以往成果的基础上,编制教师学习调节模式初测问卷;根据523份有效调查数据进行探索性因素分析;根据625份调查问卷的结果,采用内部一致性分析、结构方程模型技术和层次回归分析进行验证。结果：探索性因素分析的结果表明,教师学习调节模式由自我导向、任务导向和外部导向三个维度构成;验证性因素分析证实了教师学习调节模式的构想效度;内部一致性分析和层次回归分析的结果表明,该教师学习调节模式问卷具有较好的信度与效度。结论：教师学习调节模式是一个三因素的结构。     

NLP简快心理治疗方法的模式整合及其优势

NLP简快心理疗法于20世纪70年代创立于美国,80～90年代得到完善、发展和逐步推广。它吸取了精神分析、行为主义及人本主义流派的理论和治疗方法并加以整合优化,形成了以检定语言模式、思考与暗示语言模式、激发潜意识与自我暗示模式为优势和特点的心理咨询与治疗的方法,对心理咨询和治疗理论与实践的发展起到了积极的作用。     

《中国人群死亡及其危险因素：流行水平、趋势和分布》的主要发现

简要描述了中国人群的死亡变化趋势,主要死因构成,在不同地区和人群中的分布。结果表明结核等传染病、母婴疾病死亡率下降,冠心病、脑卒中、糖尿病、肺癌、肝癌等疾病死亡率上升明显。吸烟与被动吸烟、不良膳食习惯、静坐生活方式,是慢性病上升的重要因素;酒后驾驶等交通违章行为与每年上升10%的交通伤害死亡率密切相关。     

Change,Contradiction, and Overconfidence: Chinese Philosophy and Cognitive Peculiarities of Asians

This article discusses philosophical influence, especially the influence made by Confucianism and Daoism, on the way Asian people see and understand the world. Recently, Richard Nisbett drew a connection between Chinese philosophy (Confucianism and Daoism) and the cognitive profiles of the people who live in Asian countries where Confucianism and Daoism are strong social and cultural traditions. He argues that there is a peculiar way that Asians think and perceive things and this cognitive pattern is influenced by a group of principles derived from Chinese philosophy. This article critically analyzes Nisbett’s explanation, his emphasis on the principle of change in particular, and provides an alternative explanation of the connection between Chinese philosophy and cognitive peculiarities of Asians. Asians combine and integrate opposite viewpoints not because they believe that things change in all unexpected directions, but because they see the world as a big system with interrelated and mutually influencing components.     

A variable neighborhood search method for generalized blockmodeling of two-mode binary matrices

The clustering of two-mode proximity matrices is a challenging combinatorial optimization problem that has important applications in the quantitative social sciences. We focus on one particular type of problem related to the clustering of a two-mode binary matrix, which is relevant to the establishment of generalized blockmodels for social networks. In this context, clusters for the rows of the two-mode matrix intersect with clusters of the columns to form blocks, which should ideally be either complete (all 1s) or null (all 0s). A new procedure based on variable neighborhood search is presented and compared to an existing two-mode K-means clustering algorithm. The new procedure generally provided slightly greater explained variation; however, both methods yielded exceptional recovery of cluster structure.