Application of the transtheoretical model to identify predictors of physical activity transition in university students

Within the physical activity domain the majority of transtheoretical model research has employed a cross sectional research design. While useful for characterizing participants within the various stages of change, it fails to capture the dynamic nature of change. The purpose of the current study was to identify predictors of naturally occurring transitional shift patterns in physical activity behavior observed over six months among 202 university students. The full set of variables from the transtheoretical model as well as exercise METS was examined. Results indicated that stable active participants reported more exercise METs at baseline than both activity adopters and perpetual preparers in multinomial logistic regression analysis (p<.01). Stable active participants were also significantly different in their cognitive process of change scores compared to activity adopters (p<.05). Activity adopters differed from stable active participants in their initial decisional balance scores (p<.05). These findings should help inform theory development and physical activity interventions and programs.Dentro del dominio de la actividad física, la mayoría de la investigación de modelos transteóricos ha empleado un diseño de investigación transversal. Si bien es útil para caracterizar a los participantes en las diversas etapas del cambio, no capta la naturaleza dinámic del cambio. El propósito del presente estudio fue identificar predictores de patrones de cambio de transición que ocurren naturalmente en el comportamiento de la actividad física observados durante seis meses entre 202 estudiantes universitarios. Se examinó el conjunto completo de variables del modelo transteórico, así como el ejercicio METS. Los resultados indicaron que los participantes activos estables reportaron más MET de ejercicio al inicio que los adoptantes de actividad y los preparadores perpetuos en el análisis de regresión logística multinomial (p <0.01). Los participantes activos estables también fueron significativamente diferentes en su proceso cognitivo de puntuaciones de cambio en comparación con los adoptantes de actividad (p <0.05). Los adoptantes de actividades difirieron de los participantes activos estables en sus puntuaciones iniciales de equilibrio decisional (p <0.05). El presente estudio sugiere que los procesos cognitivos de cambio y la creación de un equilibrio decisorio positivo son factores especialmente importantes en los primeros seis meses de adopción de actividad física

Three Essays on the Selection Effect of Trade and Labor Market Rigidity

This dissertation investigates the impact of labor market conditions on the selection effect that trade causes. Since the selection effect can affect the labor market outcomes positively, this includes issues pertaining to improve the worker\u27s welfare in the long term. As a result, the main goal of the dissertation is to investigate which labor market conditions can boost the aggregate total factor productivity as the economy is more open to trade. In the first chapter, I examine when trade could cause the selection effect. If the increased average real wage induced by trade triggers the selection effect (Melitz, 2003), the main issue is to determine the labor market conditions under which trade raises the average real wage. According to the results of regressions of the average and 10th percentile of residual wages, this paper shows that with high union density, low job destruction, and low job creation, the effect of trade on the average residual wage is likely to be negative because the impact of imports exceeds that of exports. Moreover, the impact of trade on the average wage must work through the residual wage because this study does not find any significant impact of trade on average predicted wage. As a result, the more rigid the labor market is, the less likely trade is to raise the average industrial wage and the less likely the selection effect in Melitz (2003) is to occur. In the second chapter, based on the results from the first chapter, I examines whether job flows can improve the aggregate total factor productivity by using U.S. industry data set. In the third chapter, it investigates how rigidity in labor market institutions influences the selection effect as the economy is more open to trade. Findings from dynamic ordinary least square (DOLS) suggest that higher labor market rigidity in an open economy reduces the TFP through the negative selection effect. In particular, in extremely high rigidity but low foreign R\u26D stock, the openness to trade could cause the country to experience decreasing TFP because the negative selection effect can offset the international R\u26D spillover effect

Instrumental Variable Estimates of the Effect of Management Practices on Firm Performance in Korean Firms

To empirically examine the unbiased effect of management practice on firm productivity, this paper aims to suggest an instrumental variable approach, which requires less costly method. This study uses three firm-level instrumental variables such as the motivations for organizational reform, empowerment, and IT investment during the organizational reform. For empirical study, we use Korean manufacturing firm-level data that contains information on management score and financial statement. The results of the instrumental variable estimation show that better management practice leads to higher level of firm productivity statistically significantly, while the effect of management practices is statistically insignificant in the ordinary least square estimation

Instrumental Variable Estimates of the Effect of Management Practices on Firm Performance in Korean Firms

To empirically examine the unbiased effect of management practice on firm productivity, this paper aims to suggest an instrumental variable approach, which requires less costly method. This study uses three firm-level instrumental variables such as the motivations for organizational reform, empowerment, and IT investment during the organizational reform. For empirical study, we use Korean manufacturing firm-level data that contains information on management score and financial statement. The results of the instrumental variable estimation show that better management practice leads to higher level of firm productivity statistically significantly, while the effect of management practices is statistically insignificant in the ordinary least square estimation

First-principles study of electron-phonon interactions and transport in anatase TiO2

Electron transport in anatase TiO2, which has important applications in oxide electronics and photocatalysis, is still poorly understood. We investigate the electron mobility in anatase TiO2 by performing first-principles calculations of electron and phonon spectra as well as electron-phonon coupling. The formation of large polarons (quasiparticles formed by electrons interacting with phonons in a polar medium) leads to a renormalization of the electronic band structure, which we address using many-body perturbation theory. We correlate the lowering of the mobility of these quasiparticles to the renormalization of band velocities due to the electron-phonon interaction. These results explain why the mobility decreases with increasing temperature, as observed in experiments

Immigration and Economic Growth: Do Origin and Destination Matter?

This paper assesses the heterogeneous effects of immigration on economic growth depending on both the origin and the destination countries. Following the development of a simple growth model augmented by the embodied human capital of immigrants, we estimate the growth equation using a gravity-style instrument variable approach and the dynamic system-GMM estimator. We find that immigration from developed economies positively affects the economic growth of the host countries. Furthermore, the growth-enhancing effect of immigration is significantly larger when immigration flows from developed to developing economies than when it does to those that include both developed and developing economies. We interpret these results as evidence of immigrants from developed countries bringing with them – upon entry – their advanced knowledge on technology and institutions into the developing countries that host them

Immigration and Economic Growth: Do Origin and Destination Matter?

This paper assesses the heterogeneous effects of immigration on economic growth depending on both the origin and the destination countries. Following the development of a simple growth model augmented by the embodied human capital of immigrants, we estimate the growth equation using a gravity-style instrument variable approach and the dynamic system-GMM estimator. We find that immigration from developed economies positively affects the economic growth of the host countries. Furthermore, the growth-enhancing effect of immigration is significantly larger when immigration flows from developed to developing economies than when it does to those that include both developed and developing economies. We interpret these results as evidence of immigrants from developed countries bringing with them – upon entry – their advanced knowledge on technology and institutions into the developing countries that host them

GW Calculations on post-transition-metal oxides

In order to establish the reliable GW scheme that can be consistently applied to post-transition-metal oxides (post-TMOs), we carry out comprehensive GW calculations on electronic structures of ZnO, Ga2O3, In2O3, and SnO2, the four representative post-TMOs. Various levels of self-consistency (G0W0, GW0, and QPGW0) and different starting functionals (GGA, GGA + U, and hybrid functional) are tested and their influence on the resulting electronic structure is closely analyzed. It is found that the GW0 scheme with GGA + U as the initial functional turns out to give the best agreement with experiment, implying that describing the position of metal-d level precisely in the ground state plays a critical role for the accurate dielectric property and quasiparticle band gap. Nevertheless, the computation on ZnO still suffers from the shallow Zn-d level and we propose a modified approach (GW0+Ud) that additionally considers an effective Hubbard U term during GW0 iterations and thereby significantly improves the band gap. It is also shown that a GGA + U-based GW0(+Ud) scheme produces an accurate energy gap of crystalline InGaZnO4, implying that this can serve as a standard scheme that can be applied to general structures of post-TMOs. © 2014 American Physical Society.1991sciescopu