Bayesian analysis of mixtures in structural equation models with non‐ignorable missing data

Structural equation models (SEMs) have become widely used to determine the interrelationships between latent and observed variables in social, psychological, and behavioural sciences. As heterogeneous data are very common in practical research in these fields, the analysis of mixture models has received a lot of attention in the literature. An important issue in the analysis of mixture SEMs is the presence of missing data, in particular of data missing with a non‐ignorable mechanism. However, only a limited amount of work has been done in analysing mixture SEMs with non‐ignorable missing data. The main objective of this paper is to develop a Bayesian approach for analysing mixture SEMs with an unknown number of components and non‐ignorable missing data. A simulation study shows that Bayesian estimates obtained by the proposed Markov chain Monte Carlo methods are accurate and the Bayes factor computed via a path sampling procedure is useful for identifying the correct number of components, selecting an appropriate missingness mechanism, and investigating various effects of latent variables in the mixture SEMs. A real data set on a study of job satisfaction is used to demonstrate the methodology.     

Can Religion Help Prevent Obesity? Religious Messages and the Prevalence of Being Overweight or Obese Among Korean Women in California

This research examines the influence of messages from religious leaders and congregants on whether Korean women are overweight or obese. Data were drawn from telephone interviews with a probability sample (N = 591) of women of Korean descent living in California. Overweight or obese prevalence was measured using World Health Organization standards for Asians (BMI > 23). Respondents reported the frequency of messages discouraging “excessive eating” or encouraging “exercise” from religious leaders and congregants during a typical month. When conditioned on leaders’ messages, the frequency of congregants’ messages was associated with a significantly lower probability of being overweight or obese, although messages from either in the absence of the other were unassociated with being overweight or obese. At least for Korean women, religion may help prevent obesity via religious-based social mechanisms.     

妊娠合并结核临床诊治的决策

妊娠合并结核是一种对母婴健康危害极大的妊娠期疾病。在妊娠期结核病中,多数患者无明显症状,早期症状与妊娠期某些生理反应相似,加之妊娠与结核病的相互影响,x线、CT等重要的影像学检查受限,致使本病易被误诊或误治。某些抗结核药物对母婴的不良影响,使其治疗难以实施,由于结核病本身及治疗后可能对胎儿的影响,在临床上是否终止妊娠往往难以决策。本文就妊娠合并结核诊治过程中的相关问题进行综述,以期为临床诊治决策提供帮助。     

间隔时间及记忆负荷对信息缺失错误记忆的影响

现场中的信息缺失会影响人类对事件的记忆,这对证人证言研究是非常重要的,但以往对之却鲜有研究.本研究以大学生为被试,运用信息缺失范式,采用视频录像材料,通过2个实验探讨了间隔时间和记忆负荷对错误记忆的影响.结果表明:(1)间隔时间没有影响真实记忆和错误记忆,但信心水平却随着间隔时间的延长而变化;(2)记忆负荷高低没有影响真实记忆却影响了错误记忆,在关键信息呈现条件下,降低记忆负荷可以减少错误记忆的发生;(3)信息性质会影响人们的记忆,关键信息呈现条件下的错误记忆和真实记忆均高于关键信息缺失的条件.     

Gaze cueing as a function of perceived gaze direction

Previous studies have found that attention is automatically oriented in the direction of other people's gaze. This study directly investigated whether the perceiving gaze direction modulates the orienting of observers' attention. Gaze perception was manipulated by changing the face context (head orientation) of the gaze cue: the perceived gaze angle was increased (or decreased) when the head and gaze are congruent (or incongruent), while the local‐feature information of the eye region was preserved for all stimuli. The results showed that gaze‐cueing effects were enhanced when the perceived gaze direction was averted more toward left or right, and reduced when the perceived gaze direction was closer to direct gaze. The results suggest that gaze‐cueing effects are based on mechanisms specialized for gaze perception, and the magnitude of gaze‐cueing effects was probably a function of the perceived gaze direction.     

Core Knowledge Employee Creativity and Firm Performance: The Moderating Role of Riskiness Orientation,Firm Size,and Realized Absorptive Capacity

In this study, we examine when creativity is positively or negatively related to firm performance. Building on the creation–implementation tension theorized in the literature and the attention capacity perspective, we argue that the relationship between creativity and firm performance is contingent on riskiness orientation, firm size, and realized absorptive capacity. Data were collected from 761 core knowledge employees, 148 CEOs, and 148 HR executives from 148 high‐technology firms. The results indicated that core knowledge employee creativity was negatively related to firm performance when riskiness orientation was high. The relationship was positive when realized absorptive capacity was high. Finally, the relationship was more positive in small firms than in large firms. We discuss the implications of our findings for creativity research and managerial practices.     

对信息源的正向跟随倾向对决策效果的影响*

采用实验研究的方法,检验了二元选择情形下高准确率信息源(准确率x >50%)和低准确率信息源(准确率为1?x)对决策者预测效果的影响。尽管从逻辑上二者从准确率层面具有完全相等的信息价值,然而研究结果显示,决策者更倾向于采用正向跟随而非逆向跟随的方式处理来自信息源的信息。这导致低准确信息源的价值未能得以充分利用。学习和信息源的规范性对该信息处理倾向起到调节作用。     

Effect of strain rate on the compressive behaviour of a Zr56Al10.9Ni4.6Cu27.8Nb0.7 bulk metallic glass

We report the study of the effect of strain rate on the compressive behaviour of a Zr₅₆Al_10.9Ni_4.6Cu_27.8Nb_0.7 bulk metallic glass. The results indicated that both the strength and plasticity of the glass increase with increasing the strain rate up to 10^?5 s^?1, above which the strength and plasticity start to decrease. The enhanced mechanical properties under a strain rate of 10^?5 s^?1 are due to the emission/propagation rate of the shear bands being consistent with the strain rate.     

Electromechanical behavior of single-walled carbon nanotube thin films

Carbon nanotubes have been intensively studied owing to their great potential in nanoelectronics and nanomechanical devices. Recently, experimental results have shown that single-walled carbon nanotubes (SWCNTs) change their electronic properties when subjected to strain. In this study, the electromechanical characteristics of SWCNT networks were investigated for the application of printable strain sensors on flexible substrates. SWCNT films were formed on plastic substrates of poly(ethylene terephthalate) using a spray process. In this manner, we were able to control the transparency and obtain uniform electrical properties of the films. The films are isotropic on account of the random orientation of bundles of SWCNTs. Experimental results showed a nearly linear change in the resistance across a film when it was subjected to tensile strain, even in the inelastic range of the flexible substrate. The results demonstrate the potential use of SWCNT films for highly sensitive printable strain sensors on a macroscale.