转基因技术安全性的生态伦理浅析

以转基因技术为基础的生物技术是本世纪最具影响力的高新技术产业带。转基因技术在农业、食品、医药、环保等方面有广泛应用,它给人类社会的发展带来巨大的经济效益和社会效益的同时,也存在着潜在危险,即有可能影响生态环境,危害人类健康。本文试图从生态伦理的角度来思考转基因技术的安全性问题。     

新生市民主动发展倾向对城市生活适应性的影响:社会支持的中介效应

为探究主动发展倾向和社会支持对新生市民城市生活适应性的作用机制,本研究构建了结构方程模型.采用两个自编量表和一个现成量表,运用两阶段抽样调查法,在作为统筹城乡发展试验区的重庆市范围内,对已经取得城镇户口的新生市民进行问卷调查,获得有效样本322人.对采集的数据运用统计分析软件SPSS17.0和AMOS18.0进行数据分析和模型检验.结果表明,城市化新生市民的主动发展倾向和社会支持均对新生市民的城市生活适应具有显著影响,其中,社会支持在主动发展倾向对城市生活适应影响中具有部分中介作用.     

Child Care in The Netherlands: Trends in Quality Over the Years 1995-2005

The authors assessed the quality of child care in a representative national sample of 42 child-care centers in the Netherlands and compared it with the quality of care that researchers have found using similar samples in 1995 (M. H. van IJzendoorn, L. W. C. Tavecchio, G. J. J. M. Stams, M. J. E. Verhoeven, & E. J. Reiling, 1998) and 2001 (M. J. J. M. Gevers Deynoot-Schaub & J. M. A. Riksen-Walraven, 2005). In the present study, results showed a low level of overall process quality for the 2005 sample, measured by the Infant/Toddler Environment Rating Scale-Revised (T. Harms, D. Cryer, & R. M. Clifford, 2003) and the Early Childhood Environment Rating Scale-Revised (T. Harms, R. M. Clifford, & D. Cryer, 1998). The present authors found a significant decline in process quality in comparison with the 1995 and 2001 findings. They concluded that, from an international perspective, the Netherlands has lost its leading position in child-care quality compared with that from 10 years ago.     

Exploring Pathways From Television Viewing to Academic Achievement in School Age Children

The author's purpose in this study was to test 4 hypotheses that proposed different paths for the influences of children's television viewing on their academic achievement. Data were drawn from the 1997 Child Development Supplement (CDS) to the Panel Study of Income Dynamics (PSID). The population for this study included 1,203 children between the ages of 6 and 13 years from the CDS-PSID data set. The author used structural equation modeling to test pathways from children's television viewing to their academic achievement. The author assumed that children's television viewing hindered their academic achievement by reducing certain traits that related to academic achievement. Results showed that 3 hypothetical models fit the data—the time-displacement hypothesis, the mental effort-passivity hypothesis, and the attention-arousal hypothesis. A 4th hypothetical model, the learning-information hypothesis, which proposed that children's television viewing practices stimulate their academic achievement, was not supported. In sum, children who watched more television tended to spend less time doing homework, studying, and reading for leisure. In addition, their behaviors became more impulsive, which resulted in an eventual decrease in their academic achievement.     

Latent variables should remain as such: Evidence from a Monte Carlo study

Use of subject scores as manifest variables to assess the relationship between latent variables produces attenuated estimates. This has been demonstrated for raw scores from classical test theory (CTT) and factor scores derived from factor analysis. Conclusions on scores have not been sufficiently extended to item response theory (IRT) theta estimates, which are still recommended for estimation of relationships between latent variables. This is because IRT estimates appear to have preferable properties compared to CTT, while structural equation modeling (SEM) is often advised as an alternative to scores for estimation of the relationship between latent variables. The present research evaluates the consequences of using subject scores as manifest variables in regression models to test the relationship between latent variables. Raw scores and three methods for obtaining theta estimates were used and compared to latent variable SEM modeling. A Monte Carlo study was designed by manipulating sample size, number of items, type of test, and magnitude of the correlation between latent variables. Results show that, despite the advantage of IRT models in other areas, estimates of the relationship between latent variables are always more accurate when SEM models are used. Recommendations are offered for applied researchers.     

Factorial validity of the Mental Toughness Questionnaire-48

The purpose of this study was to assess the factorial validity of the Mental Toughness Questionnaire-48 (Clough, Earle, & Sewell, 2002). In total, 8207 participants (male n = 4019, female n = 3922, unspecified = 266) aged between 16 and 68 years (M = 37.00, SD = 12.09) completed the MTQ48. Model fit was assessed using confirmatory factor analysis (CFA) and exploratory structural equation modeling, in addition to the robust maximum likelihood estimator. Overall, our results support the factorial validity of the MTQ48 and indicate that the MTQ48 is a robust psychometric measure of mental toughness. Along with previous data, which supports the internal validity of the MTQ48 in addition to results of this study, it would appear that the MTQ48 is an acceptable method of assessing mental toughness.     

When emotion does and does not impair performance: A Garner theory of the emotional Stroop effect

It takes people longer to name the ink colour of emotion or threat words than that of neutral words, the emotional Stroop effect (ESE). In three experiments with normal and patient populations, we show that the ESE is a special case of a generic attention model and effect entailed in Garner's speeded classification paradigm. Guided by the Garner model we demonstrate that task-irrelevant dimensions that differ in salience can produce the ESE and mimic it with neutral stimuli. When each word appears in a constant colour, as mandated in the correlation condition of the Garner design, the ESE is eliminated. This important result is consistent with the attention account of the ESE. We conclude that when emotion stimuli appear in a random fashion they interfere with task performance. However, when emotion stimuli are correlated with features of the ongoing task they help task performance not least due to their extreme salience.     

Dynamic Regulation Responding to an External Stimulus: A Differential Equation Model

This study examines the dynamic regulation process responding to an external stimulus. The damped oscillator model has been used to describe this process. However, the model does not allow a nonzero steady state, even though the oscillations may continue and do not necessarily damp toward zero. This study introduces the driven damped oscillator model which has an additional parameter to identify different patterns of the steady state. Three methods, generalized local linear approximation, continuous time structural equation modeling, and analytic solutions of differential equations are provided to estimate model parameters. A simulation study indicates that parameters in the driven damped oscillator model are well recovered. The model is then illustrated using a data set on the daily reports of sales after a sale promotion. Potential applications and possible expansions of this model are also discussed.     

Modeling Interactions Between Latent Variables in Research on Type D Personality: A Monte Carlo Simulation and Clinical Study of Depression and Anxiety

Several approaches exist to model interactions between latent variables. However, it is unclear how these perform when item scores are skewed and ordinal. Research on Type D personality serves as a good case study for that matter. In Study 1, we fitted a multivariate interaction model to predict depression and anxiety with Type D personality, operationalized as an interaction between its two subcomponents negative affectivity (NA) and social inhibition (SI). We constructed this interaction according to four approaches: (1) sum score product; (2) single product indicator; (3) matched product indicators; and (4) latent moderated structural equations (LMS). In Study 2, we compared these interaction models in a simulation study by assessing for each method the bias and precision of the estimated interaction effect under varying conditions. In Study 1, all methods showed a significant Type D effect on both depression and anxiety, although this effect diminished after including the NA and SI quadratic effects. Study 2 showed that the LMS approach performed best with respect to minimizing bias and maximizing power, even when item scores were ordinal and skewed. However, when latent traits were skewed LMS resulted in more false-positive conclusions, while the Matched PI approach adequately controlled the false-positive rate.