Who Makes an Effort? A Person-Centered Examination of Motivation and Beliefs as Predictors of Students’ Effort and Performance on the PISA 2015 Science Assessment

Each time new PISA results are presented, they gain a lot of attention. However, there are many factors that lie behind the results, and they get less attention. In this study, we take a person-centered approach and focus on students’ motivation and beliefs, and how these predict students’ effort and performance on the PISA 2015 assessment of scientific literacy. Moreover, we use both subjective (self-report) and objective (time-based) measures of effort, which allows us to compare these different types of measures. Latent profile analysis was used to group students in profiles based on their instrumental motivation, enjoyment, interest, self-efficacy, and epistemic beliefs (all with regard to science). A solution with four profiles proved to be best. When comparing the effort and performance of these four profiles, we saw several significant differences, but many of these differences disappeared when we added gender and the PISA index of economic, social, and cultural status (ESCS) as control variables. The main difference between the profiles, after adding control variables, was that the students in the profile with most positive motivation and sophisticated epistemic beliefs performed best and put in the most effort. Students in the profile with unsophisticated epistemic beliefs and low intrinsic values (enjoyment and interest) were most likely to be classified as low-effort responders. We conclude that strong motivation and sophisticated epistemic beliefs are important for both the effort students put into the PISA assessment and their performance, but also that ESCS had an unexpectedly large impact on the results.

MODEL-BASED OPTIMIZATION OF CYCLES OF CO2 WATER-ALTERNATING-GAS (CO2-WAG) INJECTION IN CARBONATE RESERVOIR

Pre-salt reservoirs are among the most important discoveries in recent decades due to the large quantities of oil in them. However, high levels of uncertainties related to its large gas/CO2 production prompt a more complex gas/CO2 management, including the use of alternating water and gas/CO2 injection (WAG) as a recovery mechanism to increase oil recovery from the field. The purpose of this work is to develop a methodology to manage cycle sizes of the WAG/CO2, and analyze the impact of other variables related to the management of producing wells during the process. The methodology was applied to a benchmark synthetic reservoir model with pre-salt characteristics. We used five approaches to evaluate the optimum cycle size under study, also assessing the impact of the management of producing wells: (A) without closing producers due to gas-oil ratio (GOR) limit; (B) GOR limit fixed at a fixed value (1600 m³/m³) for all wells; (C) GOR limit optimized per well; (D) joint optimization between GOR limit values of producers and WAG cycles; and (E) optimization of the cycle size per injector well with an optimized GOR limit. The results showed that the optimum cycle size depends on the management of the producers. Leaving all production wells open until the end of the field's life (without closing based on the GOR limit) or controlling the wells in a more restricted manner (with closing based on the GOR limit), led to significant variation of the results (optimal size of the WAG/CO2 cycles). Our study, therefore, demonstrates that the optimum cycle size depends on other control variables and can change significantly due to these variables. This work presents a study that aimed to manage the WAG-CO2 injection cycle size by optimizing the life cycle control variables to obtain better economic performance within the premises already established, such as the total reinjection of gas/CO2 produced, also analyzing the impact of other variables (management of producing wells) along with the WAG-CO2 cycles.

Impacto de los juegos reducidos sobre la toma de decisiones y la técnica en jugadores de fútbol sub-12: efecto del espacio cerrado

The aim of the research was to analyze how the practice of small sided games influences technique and decision-making in U-12 football players male, with modification of the space. There were 12 U-12 players participating. They carried out 20 training sessions based on small sided games of football on a playing field that is surrounded by walls generating an enclosed playing space. The sample showed normal values in the Saphiro-Wilk test. The main results show that there are significant differences in the pass and control variables, and there is a significant improvement in the execution and decision-making actions. Decision-making showed significant differences in all the indicators. Therefore, it improves the technique and decisions in specific game situations, through the use of small sided games, in this way it can be considered as a methodological resource to be used in these training phases. El objetivo de la investigación fue analizar cómo influyen la práctica de juegos reducidos sobre la técnica y la toma de decisiones en jugadores sub-12 de fútbol masculino, con modificación del espacio. Participaron 12 jugadores Sub-12. Realizaron 20 sesiones de entrenamiento basado en juegos reducidos de fútbol en un campo de juego que está rodeado con paredes generando un espacio de juego cerrado. La muestra presentó valores normales en la prueba de Saphiro-Wilk. Los principales resultados mostraron que existen diferencias significativas en las variables de pase y control, y se mejoran las acciones técnicas y la toma de decisiones de forma significativa. La toma de decisiones presentó diferencias significativas en todos los índices. Por lo tanto, mejora la técnica y las decisiones en situaciones específicas de juego, mediante el uso de los juegos reducidos, de esta forma se puede considera como un recurso metodológico a utilizar en estas etapas de formación.

Impact of Corporate Social Responsibility on profitability of banks in Pakistan: Application of GMM Approach

The present study investigates the effects of corporate social responsibility (CSR) on financial performance of commercial banks in Pakistan employing the generalized method of moments (GMM) estimator on a panel data. A diverse sample of 25 banks is selected for the analyses for a period of 11 years (2010-2020) based on consistently available data. In addition to the CSR index, some bank-specific and macroeconomic variables are used as control variables to test for the effects of CSR initiatives on profitability of banks in Pakistan. Our findings demonstrate that the CSR drives and commitments on social expectations reward the banks with larger profit margins. Consequently, the results tend to validate the stakeholder theory where socially responsible enterprises lead towards greater financial performance. The control variables like capital intensity, credit risk, bank size, liquidity, age of the bank, proportion of non-executive directors, tangibility and GDP growth divulge mixed results. The diversity in results propose a number of policy and managerial implications both for policy makers and banks managers.

The Effect of Working Capital Management on Profitability of Saudi Food and Beverages Corporations: An applied study (2015- 2019): أثر إدارة رأس المال العامل على ربحية شركات صناعة الأغذية المساهمة السعودية: دراسة تطبيقية (2015- 2019)

The study examined the effect of working capital management (average inventory period, average collection period and average payment period), on the profitability of Saudi food and beverages corporations listed in Saudi exchange during five years from 2015 to 2019. In addition, company size, debt ratio and company age was used as control variables. The study used Return on Asset (ROA) and Return on Equity (ROE) as measures of firm profitability. To achieve the aim of the study, data were obtained from the annual financial reports published in the “Tadawul”, Saudia Arabia Stock Exchange, for a purposive sample of twelve (12) companies out of (203) Saudi corporations listed. Descriptive statistics and Multiple regression analysis were used to test the hypotheses of the study. The results indicated that ROA and ROE have been explained at 48%, and 55% respectively. Furthermore, the results found that there is statistically significant effect of average payment period on ROA. However, while the results found that there is statistically significant effect of all control variables on ROE, it did not find any significant effect of any the working capital management variables on ROE. Based on the results, we recommend that corporations need to pay attention to managing working capital in more efficient ways, especially through speed in collection and slow payment, which in turn lead to increased firm profitability.

Impact of corruption on Chinese investment in African countries

Purpose This paper aims to examine the impact of host country corruption on foreign direct investment (FDI) from China to developing countries in Africa. With the opposing arguments that corruption is detrimental to or instrumental in FDI and mixed empirical evidence, this paper contributes to the literature by providing new evidence on the issue. Additionally, little research has been done on the impact of corruption on FDI made by developing country multinationals to developing countries. This paper fills a void in this area. Design/methodology/approach Based on the published literature, as well as China and Africa contexts, the authors develop hypotheses that host countries with low corruption receive more FDI and resource-seeking investments weaken the relationship. The annual stock of Chinese FDI in 35 African countries, host country corruption data and other control variables from 2007 to 2015 are collected. Feasible generalized least squares models are used to test the hypotheses. Additional robustness tests are also conducted. Findings The findings support the hypotheses. Specifically, Chinese investors make more investments in host countries with low corruption except for resource-seeking investments in resource-rich host counties. The results are statistically significant accounting for various control variables. The results of the robustness tests show that the main findings are robust. Originality/value First, this study provides new evidence on the impact of corruption on FDI. Second, this study also fills a void by examining FDI from a developing country, China to other developing countries in Africa. Finally, this study also has a practical implication for Chinese multinationals investing in Africa.

Analysis and Optimization of Dimensional Accuracy and Porosity of High Impact Polystyrene Material Printed by FDM Process: PSO, JAYA, Rao, and Bald Eagle Search Algorithms

High impact polystyrene (HIPS) material is widely used for low-strength structural applications. To ensure proper function, dimensional accuracy and porosity are at the forefront of industrial relevance. The dimensional accuracy cylindricity error (CE) and porosity of printed parts are influenced mainly by the control variables (layer thickness, shell thickness, infill density, print speed of the fused deposition modeling (FDM) process). In this study, a central composite design (CCD) matrix was used to perform experiments and analyze the complete insight information of the process (control variables influence on CE and porosity of FDM parts). Shell thickness for CE and infill density for porosity were identified as the most significant factors. Layer thickness interaction with shell thickness, infill density (except for CE), and print speed were found to be significant for both outputs. The interaction factors, i.e., shell thickness and infill density, were insignificant (negligible effect) for both outputs. The models developed produced a better fit for regression with an R2 equal to 94.56% for CE, and 99.10% for porosity, respectively. Four algorithms (bald eagle search optimization (BES), particle swarm optimization (PSO), RAO-3, and JAYA) were applied to determine optimal FDM conditions while examining six case studies (sets of weights assigned for porosity and CE) focused on minimizing both CE and porosity. BES and RAO-3 algorithms determined optimal conditions (layer thickness: 0.22 mm; shell thickness: 2 mm; infill density: 100%; print speed: 30 mm/s) at a reduced computation time equal to 0.007 s, differing from JAYA and PSO, which resulted in an experimental CE of 0.1215 mm and 2.5% of porosity in printed parts. Consequently, BES and RAO-3 algorithms are efficient tools for the optimization of FDM parts.

Family Resilience: Variations by Individual Psychological and Health Resources, Social Capital and Sociodemographic Characteristics

The purposed of this study was to investigate variations in family resilience across individuals’ sociodemographic characteristics, psychological and health resources, and social capital. Using the Tailored Design Method, survey data were collected from rural residents in a single U. S. state which yielded 812 responses and a 30% response rate. Family resilience was measured by the 2015 Walsh Family Resilience Questionnaire. The other variables were measured by prevalent existing instruments and standard survey items. A three-model regression analysis was conducted. Results indicated that 37% of the variance in family resilience was explained by the independent variables of social capital, including trust, overall health, depressive symptoms, optimism and life satisfaction, and the control variables of socioeconomic-demographic characteristics. The strongest predictor of family resilience was optimism. In almost all instances, the control variables were weaker predictors than the independent variables, particularly depressive symptoms and social capital. The study sheds light on possible ways for helping professionals to guide families in becoming more resilient and calls for a social determinants of health, culturally sensitive and trauma-informed approach.

Optimal control for dengue eradication program under the media awareness effect

In this article, a mathematical model is proposed to assess the effects of media awareness on dengue eradication programs. First, the existence and local stability of equilibrium points are discussed using the concept of the basic reproduction number. Using the center-manifold theorem, it is shown that the proposed model always undergoes a forward bifurcation at the basic reproduction number equal to unity. It is observed that the high-intensity media awareness could reduce the size of the endemic equilibrium. Based on local sensitivity analysis, we identify the three most sensitive parameters, namely the natural death rate of mosquito (μ v ), infection rates (β h1, β v1), and hospitalization rate (η). Hence, control variables need to be introduced to increase/reduce these parameters. In this article, we use three different control variables, namely the media campaign, (u 1(t)), to reduce infection rates, additional hospitalization rate, (u 2(t)), and fumigation rate, (u 3(t)), to increase mosquitoes death rate. Pontryagin’s maximum principle is used to determine the optimal conditions. Some numerical simulations are performed to describe a possible scenario in the field. Cost effectiveness analysis is then conducted to determine the best strategy for the dengue eradication program. We conclude that a combination of media campaigns and fumigation is the most effective strategy to prevent a significant increase in the number of infected individuals.

Dynamic Relationship Between China’s Environmental Protection Investment and Regional, Environmental Pollution

The carrying capacity of China’s resources and environment has reached a limit. The economic development of different regions has been forced to abandon the original economic development mode manifesting high pollution, high energy consumption, and high emission and to step forward to the new economic development model promoting low energy consumption, low emission, and low pollution. Environmental issues are typical manifestations of market mechanism failure. Government investment in environmental protection, which effectively improves environmental quality, is necessary to achieve sustainable economic development. An index system of the influencing factors that affect regional environmental pollutant emissions was established first in this study to measure accurately the relationship between environmental protection investment in different provinces in China and regional environmental pollution. System GMM (Generalized Method of Moment) method was used to analyze the impact of environmental protection investment on pollutant emissions in 30 provinces in China from 2007 to 2016. Results show that the system GMM method can effectively solve variable endogeneity. Environmental protection investment of explanatory variables has a significant negative effect on pollutant emissions. Among the control variables, per capita GDP (Gross Domestic Product), industrial structure, resident consumption level, and technology market turnover have a significant inhibitory effect on pollutant emissions. Among the control variables, investment in fixed assets and import and export trade is vital in promoting pollutant emission growth. Conclusions provide a reference for improving the governance level of environmental protection investment in China’s provinces, controlling environmental pollution and ecological damage, and realizing a green economic development method.