Model comparison of nonlinear structural equation models with fixed covariates

Recently, it has been recognized that the commonly used linear structural equation model is inadequate to deal with some complicated substantive theory. A new nonlinear structural equation model with fixed covariates is proposed in this article. A procedure, which utilizes the powerful path sampling for computing the Bayes factor, is developed for model comparison. In the implementation, the required random observations are simulated via a hybrid algorithm that combines the Gibbs sampler and the Metropolis-Hastings algorithm. It is shown that the proposed procedure is efficient and flexible; and it produces Bayesian estimates of the parameters, latent variables, and their highest posterior density intervals as by-products. Empirical performances of the proposed procedure such as sensitivity to prior inputs are illustrated by a simulation study and a real example.This research is fully supported by a grant from the Research Grant Council of the Hong Kong Special Administrative Region, China (Project No. CUHK 4346/01H). The authors are thankful to the Editor, the Associate Editor, and anonymous reviewers for valuable comments which improve the paper significantly, and grateful to ICPSR and the relevant funding agency for allowing use of the data in the example. The assistance of Michael K.H. Leung and Esther L.S. Tam is gratefully acknowledged.     

Dietary ethyl-eicosapentaenoic acid but not soybean oil reverses central interleukin-1-induced changes in behavior, corticosterone and immune response in rats

Omega (n)-3 and n-6 fatty acids are important membrane components of neurons and immune cells, and related to psychiatric and inflammatory diseases. Increased ratio of n-6/n-3 in the blood has been reported in depressed patients and in students following stress exposure. The n-3 fatty acid, eicosapentaenoic acid (ethyl-EPA) suppresses inflammation and has antidepressant properties. Interleukin (IL)-1beta can stimulate corticosterone secretion, induce anxiety and stress-like behavior and inflammatory responses. This study was to evaluate the effect of diets enriched with coconut oil, ethyl-EPA and soybean oil on central IL-1beta induced stress and anxiety-like behavior, induced changes in the concentration of prostaglandin (PG) E2 and corticosterone and the release of IL-10. Groups of rats were fed with either 5% coconut oil (as control diet), 0.2% EPA with 4.8% coconut oil or 1% EPA with 4% coconut oil and 5% soybean oil for 7 weeks. The central administration of IL-1beta induced sickness, stress and anxiety-like behavior as indicated by a reduction in body weight, decreased time spent, and the number of entries, into the open arms of the elevated plus maze and decreased exploration and entry into the central zone of the "open field" apparatus. IL-1beta also increased PGE2 and corticosterone concentrations and decreased the release of IL-10 from leucocytes. Food enriched with ethyl-EPA but not soybean oil, significantly attenuated most of these changes. These results demonstrate that ethyl-EPA has anti-inflammatory, anti-stress and anti-anxiety effects in rats.     

On ethical order

The existent ethical relationships are the result of the historical amalgamation of objective and subjective conditions. Ethical relationships are essential relationships in the real and rational order, which are maintained by a system of regulations on morals, laws and customs, and infused with a spirit of subjectivity. Rationality and legitimacy are the primary concerns of those relationships. A distinction between morals and ethos needs to be made when studying ethical order. Sound ethical order lies in effective regulation of morals and effective control of law. In the process of social reform, ethical order promotes social development through the dialectical movement of freedom and necessity. A harmonious society is a society which is based on legitimate and just ethical order. Translated by Cui Hui from Lunlixue yanjiu 伦理学研究 (Studies in Ethics), 2007, (5): 1–8     

The Study of College Students’ Beliefs in China

Pastoral Psychology - The beliefs of college students is an important issue that is followed closely by the Government of China (GOC). In recent years, the GOC increasingly has encouraged the...     

Sequence effects by non-predictive arrow cues

Previous studies have found that attention orienting is influenced by the orienting processes of previous trials in a spatial cueing paradigm. This study mainly investigated whether this sequence effect could happen for a non-predictive arrow cue and whether it was influenced by the cue-target SOAs in previous and current trials. A significant sequence effect was observed for arrow cues even when voluntary control was not required, and it was significantly influenced by the SOAs of previous trials. The present results support the automatic memory check hypothesis and may reflect some temporal characteristics of the memory mechanism in sequential processes. In addition, contrary to the previous findings, we found an overall response facilitation following a catch trial, suggesting that the influence of preceding catch trials may be sensitive to experimental contexts.     

Effects of stimulation by three-dimensional natural images on prefrontal cortex and autonomic nerve activity: a comparison with stimulation using two-dimensional images

Empirical evidence suggests that three-dimensional (3D) images of nature promote physiological relaxation in humans by providing more realistic effects compared with two-dimensional (2D) images. However, no studies have evaluated the physiological relaxation effects of nature-derived 3D images on prefrontal cortex and autonomic nerve activity. The present study aimed to clarify the physiological relaxation effects of visual stimulation by 3D flower images on prefrontal cortex and autonomic nerve activity. Nineteen male university students (22.2 ± 0.6 years) were presented with 3D and 2D images of the water lily for 90 s. Prefrontal cortex activity was measured using near-infrared spectroscopy, while autonomic nerve activity was measured using heart rate variability (HRV). Psychological effects were determined using a modified semantic differential method (SD). Compared with visual stimulation by 2D images, that by 3D images resulted in a significant decrease in oxyhemoglobin concentration in the right prefrontal cortex, lower sympathetic activity as calculated by the ratio of the low-frequency to high-frequency HRV component, and a significantly greater realistic feeling as evidenced by higher SD ratings. In conclusion, visual stimulation by realistic 3D floral images promotes physiological relaxation more effectively than the corresponding 2D image.     

初中男生个体攻击性与群体攻击性的差异

运用实验法和问卷法对118名初中男学生进行攻击性的研究.比较了四种不同类型的攻击行为.包括群体之间、个体之间、群体与个体之间、个体与群体之间.结果显示:群体无论是作为攻击来源还是攻击目标都能起到增加攻击行为的情境作用;个体之间与群体之间在攻击性方面有显著差异;群体之间相互作用时表现出的攻击性远高于个体之间相互作用时表现出的攻击性:个体与群体相互作用时比个体之间相互作用时表现出更高的攻击性.     

U.K. consumers' perceived risk of buying products from emerging economies: A moderated mediation model

Although considerable research has been conducted on consumer attitude towards foreign products, most of these studies focus on the attitude of products from Western developed countries. Our study intends to investigate the effects of consumers' national identification and culture sensitivity on their perceived risk of buying products from Eastern developing countries. Especially, this study advances the literature by identifying the mediation effect of consumer ethnocentrism and the moderating effect of consumer value consciousness. Taking China and India as focal emerging economies, the consumer survey (n = 308) in the United Kingdom produced the following results. First, U.K. consumers' national identification is positively related to their perceived risk of buying Eastern products through consumer ethnocentrism, whereas their cultural sensitivity has a negative relationship. Second, the effect of consumer ethnocentrism on the perceived risk of buying Eastern products is moderated by consumer value consciousness. Third, value consciousness also attenuates the indirect relationships between national identification or cultural sensitivity and perceived risk via consumer ethnocentrism.