ABSTRACT
Resumen El objetivo de este estudio fue observar los estilos de resiliencia entre estudiantes de pregrado y explorar la forma en la que cada uno de ellos se encontraba asociado al engagement académico y a las redes de apoyo social al inicio de los estudios universitarios. La muestra correspondió a 371 estudiantes de pregrado del Caribe Colombiano evaluados a partir de un análisis estadístico de clústeres, por el método jerárquico aglomerativo. Posteriormente se clasificaron en grupos de acuerdo con sus similitudes en las 12 dimensiones de resiliencia y finalmente se compararon en términos de engagement y redes personales. Los resultados señalaron cuatro perfiles de estudiantes: (1) sujetos con baja-resiliencia, alto engagement y fuertes vínculos relacionales; (2) resilientes-en-proceso, con niveles intermedios de resiliencia, bajo engagement y redes sociales con poca cercanía; (3) resilientes-autónomos con altos puntajes de resiliencia, niveles intermedios de engagementy redes sociales débiles; y (4) resilientes-con-redes, exhibieron altos niveles de resiliencia, con alto engagement y amplias redes de apoyo. Se concluye que la mayor porción de jóvenes que comienzan la universidad muestra perfiles de baja resiliencia; sin embargo, los altos niveles de motivación por los estudios y los recursos sociales como las redes de apoyo de los compañeros son las condiciones que más permiten afrontar los obstáculos de la vida universitaria. Es importante notar que solamente el último perfil integró los elementos de alta resiliencia, alto engagement y fuertes redes de apoyo que permiten confirmar la íntima asociación entre estos constructos. Los otros perfiles representan casos en los cuales los rasgos de resiliencia son independientes de los niveles de engagement y de la composición de las redes de apoyo personal.
Abstract Adjustment of first-year students to university environments, as well as their academic success, is not exclusively related to their academic aptitude; instead, this adjustment is associated with psychological characteristics, personal and even social resources that help students cope with stressors and new circumstances. A comprehensive assessment of the students' adjustment to university environment must transcend preoccupation on academic performance, and instead explore associations among psychological, academic, and social elements that promote adaptation during the initial years of higher education (Marenco-Escuderos et al., 2021). In this line of research, the objective of this work was to inquire how internal characteristics of students (psychological and academic) interplay with external elements in their support systems to promote adaptation in a higher education environment. Associations were explored among resilience, academic engagement, and social support as determining elements in the adjustment to the demands of the university context. The sample consisted of 371 undergraduate students (60 % female), of low socioeconomic status, enrolled in public universities in the Caribbean region of Colombia. Firstly, the resilience of university students was explored, as the ability to respond to obstacles with a positive view of the world, of others, and of one's own abilities to cope with stressors (Saavedra-Guajardo et al., 2019). Second, the level of engagement that drives young students to concentrate their energies on academic activities was reviewed; and third, the role of peers, and friends as the close-support system that facilitates the overcoming of personal and academic difficulties was investigated (Fernández-Martínez et al., 2017). Based on a statistical cluster analysis, by the agglomerative hierarchical method, individuals were classified according to their similarities in the expression of 12 dimensions of resilience (SV-RES scale), and subsequently compared in terms of engagement (UWES-S scale), and personal support networks (UNICET software). The results showed four student profiles: (1) the largest group consisting of students with low-resilience, high engagement and strong support networks; (2) a resilient group with low levels of engagement and support networks with little intimacy; (3) a resilient group with high characteristics of autonomy, intermediate levels of engagement, and support networks with weak structure; and (4) a very resilient group, high engagement, and wide and strong social support networks. The results point out the fact that the greatest proportion of students who start college show profiles of low resilience, however, high levels of motivation for studies and social resources such as peer support networks are the conditions that mostly allow for coping with adversity in the first years of college. These results could point to cultural aspects specific to the Caribbean region, where social networks are of great importance for daily functioning (Marenco-Escuderos et al., 2021). Regarding the association among the studied variables, it is important to note that only the last profile gathered all elements of high resilience, high engagement, and strong support networks that allow for confirming the association among these constructs. The other three profiles represent cases in which the resilience traits are independent of the students' levels of engagement and the composition of their personal support networks. This study is valuable as it provides a differentiating picture of the relationship of resilience with other psychological and social constructs, and in that it allows to better understand resilience in association with other elements that mediate its interpretation. Important gender differences among the profiles are additionally discussed.
ABSTRACT
Resumen En el presente estudio se realizaron cálculos con base en la Teoría del Funcional de la Densidad Electrónica (DFT) con la aproximación B3PW91/LANL2DZ para optimizar los sistemas monometálicos y bimetálicos Au9, Au8Pd, Au8Pt, AuPd8, AuPt8, Pd9 y Pt9. Los materiales fueron teóricamente evaluados como catalizadores para la oxidación de monóxido de carbono (CO) y se determinó el sistema más favorable para la adsorción de esta molécula. La sustitución de átomos de Pt y Pd por átomos de Au en los nonámeros generó un cambio en la estructura tridimensional del sistema. El análisis de reactividad global mostró que el clúster más reactivo es PÍ9, seguido por AuPt s . Los índices de Fukui identificaron los sitios más susceptibles para un ataque nucleofílico de ambos clústeres. La adsorción de CO generó una cascada de oxidación que liberó ~4,5 eV, indicando que la reacción es altamente exotérmica y exergónica. Los clústeres AuPt s y Pt 9 mostraron los valores más bajos de energía de activación de la etapa determinante del mecanismo. En general, la sustitución de un átomo de platino (o paladio) por un átomo de oro no afecta la reactividad de los nonámeros y, por tanto, se infiere que el clúster AuPt s podría ser un catalizador promisorio en la oxidación de CO.
Abstract In the current study were development calculations based on Density Functional Theory (DFT) with the B3PW91/LANL2DZ approach for optimizing both monometallic and bimetallic systems: Au9, AusPd, Au8Pt, AuPds, AuPts, Pd9 y Pt9. Such materials were theoretically tested as catalyst for the oxidation of carbon monoxide (CO) and the most favorable system for its further adsorption was determined. The substitution of Pt and Pd by Au atoms in the nonamers generated a change in the tridimensional structure of the system. The global reactivity analysis showed that the most reactive cluster is Pt9 followed by AuPts. On the other hand, the Fukui indexes identified the most susceptible sites for a nucleophilic attack of both clusters. The CO adsorption generated an oxidation cascade which liberated ∼ 4.5 eV, indicating that the reaction is highly exothermic and exergonic. Both AuPt8 and Pt9 showed the lowest values of activation energy in the determining step of the mechanism. In general, the substitution of a Pt (Pd) atom by an Au atom does not affect the reactivity of the nonamers and then it is inferred that the AuPds cluster could be a promissory catalyst in the CO oxidation.
Resumo No presente estudo, cálculos baseados na Teoria do Funcional da Densidade Eletrônica (DFT) com a abordagem B3PW91/LANL2DZ foram realizados para otimizar sistemas monometálicos e bimetálicos Au9, Au8Pd, Au8Pt, AuPd8, AuPt8, Pd9 y Pt9. Tais materiais foram teoricamente avaliados como catalisadores para a oxidação do monóxido de carbono (CO) e foi determinado o sistema mais favorável para a adsorção desta molécula. A substituição dos átomos de Pt e Pd por átomos de Au nós não-nomes gerou uma mudança na estrutura tridimensional do sistema. A análise de reatividade global mostrou que o cluster mais reativo é Pt9, seguido por AuPt8. Os índices de Fukui identificaram os sítios mais suscetíveis ao ataque nucleofílico de ambos os clusters. A adsorção de CO gerou uma cascata de oxidação que liberou ~4,5 eV, indicando que a reação é altamente exotérmica e exergônica. Os aglomerados AuPt 8 y Pt 9 apresentaram os menores valores de energia de ativação do estágio determinante do mecanismo. Em geral, a substituição de um átomo de platina (ou paládio) por um átomo de ouro não afeta a reatividade dos não-nomes e, portanto, infere-se que o aglomerado AuPt 8 pode ser um catalisador promissor na oxidação do CO.
ABSTRACT
Tres fueron los objetivos: a) explorar la influencia que ejercen las metas sociales y de logro (aproximación/evitación) en el esfuerzo y diversión de los estudiantes de Educación Física, b) examinar los perfiles motivacionales de los adolescentes desde un marco holístico y c) estudiar las posibles diferencias entre perfiles en el esfuerzo y la diversión autoinformados. Los participantes fueron 479 estudiantes de secundaria (M = 14.36, DE = 1.58). Las metas de aproximación-maestría y evitación-amistad fueron los únicos predictores positivos del esfuerzo, mientras que las metas de aproximación-maestría y aproximación-amistad fueron los únicos predictores positivos de la diversión. Emergieron tres perfiles de clúster: (a) metas sociales bajas, (b) metas altas y (c) metas sociales altas y de logro moderadas a bajas, siendo los dos últimos más adaptativos. Los estudiantes varones se divirtieron significativamente más que las mujeres.
The present study had three goals: a) to explore the influence of social and achievement goals (approach-avoidance), individually and together, on physical education studentseffort and enjoyment, b) to examine the studentsmotivational profiles from a holistic framework, and c) to study existing profiles differences in studentsself-informed effort and enjoyment. 479 secondary education students participated in the study (M = 14.36, SD = 1.58). Results showed that mastery-approach and friendship-avoidance goals were the only positive predictors of effort, while mastery-approach and friendship-approach goals were the only positive predictors of enjoyment. Three clusters emerged from the sample: (a) low social goals, (b) high social and achievement goals, and (c) high social goals and medium-low achievement goals. The last two clusters were more adaptive. Males showed higher enjoyment scores than females.