Academic achievement in spanish secondary school students: The inter-related role of executive functions, physical activity and gender

There is a growing interest in determining which variables contribute to students’ academic performance, since this performance is associated with their wellbeing and with the progress of the nation. This study analyzed whether different variables (executive functions and physical activity levels, gender and academic year) of 177 Spanish Compulsory Secondary School students contributed to their academic performance. The Behavior Rating Inventory of Executive Function 2 (BRIEF-2), Physical Activity Questionnaire for Adolescents (PAQ-A) and an ad hoc questionnaire were used to determine the students’ executive functioning, physical activity level, gender and academic year, respectively. Students’ grades were considered to be indicators of their academic achievement. Seven multiple linear regression models were constructed using the R computing language to examine the association between academic achievement (considered in each of the 5 subjects: Language, Mathematics, Geography and History, English and Physical Education; the mean of the instrumental subjects—Language and Mathematics—and the mean of all the subjects) and the independent variables. The results indicated that executive functions, physical activity and gender contributed to academic performance, but academic year did not. This suggests that students with good executive functions, who perform physical activity and are female, would have better academic achievement. This information should be considered when designing interventions to improve student academic achievement

Discrete analysis of dividend payments in a non-life insurance portfolio

The process of free reserves in a non-life insurance portfolio as defined in the classical model of risk theory is modified by the introduction of dividend policies that set maximum levels for the accumulation of reserves. The first part of the work formulates the quantification of the dividend payments via the expectation of their current value under different hypotheses. The second part presents a solution based on a system of linear equations for discrete dividend payments in the case of a constant dividend barrier, illustrated by solving a specific case.dividend policies, expected present value

Esquemas de prueba en torno al concepto de proporcionalidad en los libros de texto

Además de su valor matemático, la importancia de la demostración desde el punto de vista de la Educación Matemática está ampliamente aceptada. La actividad demostrativa suele reservarse para los cursos superiores (Bachillerato o Universidad) por ser un proceso complejo. Sin embargo, existen numerosos autores que abogan por la introducción de este proceso en etapas previas. Así, Vallejo y Ordóñez (2015) realizan una experiencia con alumnos de 7-8 años que argumentan para justificar una afirmación relacionada con la división de números naturales. Stylianides y Stylianides (2009) consideran, en base a criterios educativos y psicológicos, que es apropiado y razonable introducir la demostración y el razonamiento deductivo en niveles inferiores al instituto

Locally nilpotent linear groups with the weak chain conditions on subgroups of infinite central dimension

Let V be a vector space over a field F. If G≤GL(V, F), the central dimension of G is the F-dimension of the vector space V/CV (G). In [DEK] and [KS], soluble linear groups in which the set Licd(G) of all proper infinite central dimensional subgroups of G satisfies the minimal condition and the maximal condition, respectively, have been described. On the other hand, in [MOS], periodic locally radical linear groups in which Licd(G) satisfies one of the weak chain conditions (the weak minimal condition or the weak maximal condition) have been characterized. In this paper, we begin the study of the non-periodic case by describing locally nilpotent linear groups in which Licd(G) satisfies one of the two weak chain conditions

Anomalies in the procedure of identifying misconceptions in mathematics written exams.

Continuando el trabajo realizado en (Autores, 2012), se exponen en este artículo los resultados sobre un estudio indagatorio sobre la corrección de exámenes de matemáticas de las Pruebas de Acceso a la Universidad en el que se analizan y categorizan ciertas actuaciones de los correctores cuando identifican errores en las producciones de los estudiantes. A la luz de este análisis, se proponen recomendaciones con el fin de que el proceso de calificación sea más fiable.Following the research started in (Autores, 2012), in this paper we present the results of an exploratory study about how some assessors identify misconceptions of students in some mathematics written exams from a University Entrance Examination. We analyze and categorize some of those assessments and we make recommendations for scoring procedure with the purpose of increasing reability.Este artículo surge del trabajo desarrollado por el grupo de investigación “S119-Investigación en Educación Matemática” financiado por el Plan Autonómico de Investigación del Gobierno de Aragón y el Fondo Social Europeo.peerReviewe

Study of the thermal degradation of bioactive sol-gel coatings for the optimization of its curing process

A set of materials has been prepared by sol-gel process containing different quantities of hydroxyapatite (0, 2.5 and 5% HAp w/w) using as silica precursors glycidyloxypropyltrimethoxysilane (GPTMS) and triethoxyvinylsilane (VTES). In order to optimize the curing process to obtain sintherized systems (inorganic network) or hybrid systems (organic&-inorganic) a TG and FTIR studies have been developed and degradation kinetic triplet parameters were obtained (the activation energy, pre-exponential factor, and function of degree of conversion). The kinetic study was analyzed by means of an integral isoconversional non-isothermal procedure (model free), and the kinetic model was determined by the Coats&-Redfern method and through the compensation effect (IKR). All the systems followed the n = 6 kinetic model. The addition of HAp increases the thermal stability of the systems. The isothermal degradation was simulated from non-isothermal data, and the curing process could be defined to obtain the two types of materials. Temperature under 250 °C allows the formation of hybrids networks.Publicad

Learning Robust Features for Gait Recognition by Maximum Margin Criterion

Extended abstract. The full research paper "Learning Robust Features for Gait Recognition by Maximum Margin Criterion" has been accepted for publication at the 23rd IEEE/IAPR International Conference on Pattern Recognition (ICPR 2016), Cancun, Mexico, December 2016

A diagnostic comparison of Spanish and Turkish middle school students’ proportional reasoning

This small-scale comparative study investigated Spanish and Turkish middle school students’ mastery of four core cognitive skills required for proportional reasoning using the log-linear cognitive diagnosis model. We compared students in the two samples for their proportional reasoning and provided a diagnostic assessment of their strengths and weaknesses. The study included 314 Spanish eighth grade and 282 Turkish seventh grade students. The students were administered a proportional reasoning test with 22 multiple-choice items. We found significant differences between the two samples in two of the cognitive skills. While the Spanish sample were better at understanding nonproportional relationships, the Turkish sample were better at understanding the concept of ratio. Furthermore, while the Spanish sample had a more dispersed distribution of students among different attribute profiles, the Turkish sample mostly consisted of either low-performing or high-performing students. To better understand the similarities and differences between the two samples, we compared students’ performance on some specific test items. The study shows how cognitive diagnostic models, which are not widely used in small-scale comparative studies, can be very useful in revealing similarities and differences between two samples that cannot be detected by traditional psychometric models

Politicas de dividendos y probabilidad de ruina

In this paper we introduce different kinds of dividend barriers in the classical model ruin theory. We study the influence of barrier strategy on ruin probability. A method based on renewal equations [Grandell (1991)], alternative to differential argument [Gerber (1975)], is used to get the partial differential equations to solve survival probabilities. Finally we calculate and compare the survival probabilities using the linear and the parabolic dividend barrier, with help of simulation.ruin, survival probability, theory, dividend barriers