MHD Remote Numerical Simulations: Evolution of Coronal Mass Ejections

Coronal mass ejections (CMEs) are solar eruptions into interplanetary space of as much as a few billion tons of plasma, with embedded magnetic fields from the Sun's corona. These perturbations play a very important role in solar--terrestrial relations, in particular in the spaceweather. In this work we present some preliminary results of the software development at the Universidad Nacional Autonoma de Mexico to perform Remote MHD Numerical Simulations. This is done to study the evolution of the CMEs in the interplanetary medium through a Web-based interface and the results are store into a database. The new astrophysical computational tool is called the Mexican Virtual Solar Observatory (MVSO) and is aimed to create theoretical models that may be helpful in the interpretation of observational solar data.Comment: 2 pages, 1 color figure. To appear in Proceedings IAU Symposium No. 259. Cosmic Magnetic Fields: From Planets, to Stars and Galaxies. In pres

On slice regular Bergman spaces and fiber bundles

Recently, fiber bundle theory has been widely used in the study of the slice regular functions and continuing with this line of research, the present work shows that the quaternionic slice regular Bergman space is the base space of a coordinate sphere bundle and some properties of quaternionic slice regular Bergman theory are studied from the point of view of the fiber bundle theory

Academic stress in students of health sciences

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Síntesis óptima de un mecanismo para la marcha bípeda utilizando evolución diferencial

ResumenEl diseño de la extremidad de un robot bípedo es un punto clave para mejorar la locomoción y el desempeño de robots bípedos. El empleo de mecanismos que reproduzcan la marcha no es una tarea sencilla ya que se requiere generar un movimiento en el espacio Cartesiano con más grados de libertad que los considerados en un mecanismo. En este trabajo se propone un mecanismo planar de ocho eslabones con un grado de libertad como extremidad bípeda y se analiza su comportamiento en el seguimiento de una trayectoria similar a la marcha. Para el diseño del mecanismo propuesto se establece formalmente la síntesis dimensional como un problema de optimización numérica. Con el propósito de obtener diseños viables dentro del espacio de las soluciones reales en el problema de optimización, se incorpora un mecanismo de manejo de restricciones en el algoritmo de evolución diferencial (ED) y se analiza el comportamiento del algoritmo bajo diferentes parámetros de cruza. Resultados experimentales comprueban el enfoque de diseño en un prototipo de laboratorio.AbstractThe limb design for a biped robot is a key issue to improve the locomotion and the performance of biped robots. The use of mechanism for tracking the gait is not an easy task because the degree of freedom (d.g.f) of the Cartesian space movement does not correspond to the d.g.f of the mechanism. Hence in this paper, an eight-bar planar mechanism with a one d.o.f is proposed as biped limb and the biped gait tracking behavior in the mechanism is analyzed. A numeric optimization problem is formally stated to design the proposed mechanism based on dimensional synthesis. A constraint handling mechanism is included into the differential evolution algorithm (DE) algorithm in order to obtain mechanism design with real solutions in the optimization problem and the behavior of the algorithm with different crossover parameters is analyzed. Experimental results verify the design approach in a laboratory prototype

A quaternionic fractional Borel-Pompeiu type formula

Quaternionic analysis relies heavily on results on functions defined on domains in $\mathbb R^4$ (or $\mathbb R^3$) with values in $\mathbb H$. This theory is centered around the concept of $\psi-$hyperholomorphic functions i.e., null-solutions of the $\psi-$Fueter operator related to a so-called structural set $\psi$ of $\mathbb H^4$. Fractional calculus, involving derivatives-integrals of arbitrary real or complex order, is the natural generalization of the classical calculus, which in the latter years became a well-suited tool by many researchers working in several branches of science and engineering. In theoretical setting, associated with a fractional $\psi-$Fueter operator that depends on an additional vector of complex parameters with fractional real parts, this paper establishes a fractional analogue of Borel-Pompeiu formula as a first step to develop a fractional $\psi-$hyperholomorphic function theory and the related operator calculus

Academic stressors perceived by University studies of health sciences

[Resumen] El propósito de esta investigación es identificar qué situaciones del contexto académico son percibidas como generadoras de estrés en una muestra de estudiantes de ciencias de la salud y en qué medida lo hacen. Adicionalmente, se analizan las diferencias en estos estresores académicos percibidos en función de las variables contextuales de la titulación y el curso. Para la medida de los estresores académicos ha sido empleada la escala de estresores académicos, que forma parte del cuestionario de estrés académico. Los resultados de este trabajo revelan que los exámenes y las intervenciones en público, por este orden, son las 2 situaciones académicas percibidas como más estresantes. Estos resultados sugieren que las situaciones más directas y claramente relacionadas con la evaluación son las que generan un mayor estrés a los estudiantes. Muy próximos se encuentran también los promedios resultantes en los factores sobrecarga del estudiante y deficiencias metodológicas del profesorado, factores que podemos considerar comparten la característica de externalidad e incontrolabilidad con respecto a los anteriores. Asimismo, existen diferencias significativas entre los grupos de estudiantes establecidos en función de la titulación que cursan en los estresores sobrecarga del estudiante, carencia de valor de los contenidos de aprendizaje y estudio y baja autoestima académica. Por lo que respecta a la variable curso, nuestros datos indican que existen diferencias significativas en los estresores falta de control sobre el propio rendimiento, exámenes e imposibilidad de participar en las decisiones respecto del propio trabajo académico, siendo el grupo de segundo el que obtiene la puntuación media más elevada en los 3 casos.[Abstract] This study aimed to identify those situations within the academic context that are perceived as stress generators in a sample of university students of Health Sciences and the amount of their impact. We also analyzed the differences in the academic stressors perceived based on the variables of career and academic year. These were measured with the Academic Stress Questionnaire, which forms a part of the Academic Stress Questionnaire (ASQ). The results of this project show that Exams and Public Participation are, in this order, the academic stressors most perceived. These findings suggest that the situations that are most directly and clearly related with the evaluation are those that generate the most stress to the students. The result averages in the factors Student burden and Teacher methodological shortcomings are very close to the above findings. We can consider that these four factors share the fact that they are external and uncontrollable in regards to the previous ones. In addition, there are significant differences among students groups of students established based on the career they are studying in the stressors Student burden, Low valuation of study and learning contents and Low academic self-concept. Regarding the academic year factor, our results show that there are significant differences in the following 3 stressors: Lack of control about own academic achievement, Exams and Impossibility of participating in decisions about one's own academic work. In these cases, second year students show, on average, the highest scores

A quaternionic proportional fractional Fueter-type operator calculus

The main goal of this paper is to construct a proportional analogues of the quaternionic fractional Fueter-type operator recently introduced in the literature. We start by establishing a quaternionic version of the well-known proportional fractional integral and derivative with respect to a real-valued function via the Riemann-Liouville fractional derivative. As a main result, we prove a quaternionic proportional fractional Borel-Pompeiu formula based on a quaternionic proportional fractional Stokes formula. This tool in hand allows us to present a Cauchy integral type formula for the introduced quaternionic proportional fractional Fueter-type operator with respect to a real-valued function.Comment: 20 page

Emotion regulation profiles and academic stress in Physiotherapy students

[Resumen] El objetivo de este estudio es identificar los diferentes perfiles de regulación emocional presentes en una muestra de estudiantes universitarios y analizar si entre los perfiles identificados existen diferencias en la percepción de estresores académicos y en las respuestas psicofisiológicas de estrés. Participaron 504 estudiantes de fisioterapia de diferentes universidades españolas, el 74% de sexo femenino y con una edad promedio de 21.06 ± 3.74 años a los que se les administró la Escala de Dificultades en la Regulación Emocional (DERS) y el Cuestionario de Estrés Académico (escala de estresores [ECEA] y escala de respuesta [RCEA]). El análisis de conglomerados identificó tres perfiles de regulación: alta regulación emocional, baja regulación emocional y baja regulación emocional con alta atención. Se obtuvieron diferencias estadísticamente significativas entre los diferentes perfiles tanto para la percepción de estresores como para las respuestas psicofisiológicas de estrés. Los estudiantes con un perfil de alta regulación emocional percibieron en menor medida el entorno académico como amenazante y experimentaron con menor frecuencia manifestaciones psicofisiológicas de estrés. Los estudiantes con perfiles de baja regulación y baja regulación con alta atención emocional mostraron resultados similares, a excepción de las alteraciones del sueño. En conclusión, los estudiantes de fisioterapia con elevadas puntuaciones en control y aceptación de sus estados emocionales perciben las circunstancias académicas de forma más adaptativa y experimentan menores respuestas de estrés.[Abstract] A study was designed with the aim of identifying different profiles of emotional regulation in a sample of university students, and analysing the differences among the identified profiles in relation to stressors perception and psychophysiological stress responses. The participants were 504 Spanish physiotherapy students (74% women), with a mean age of 21.06 ± 3.74 years old, which answered the Difficulty Emotion Regulation Scale (DERS) and the Academic Stress Questionnaire (stressors scale [ECEA] and response scale [RCEA]). Based on Cluster analysis, three emotional regulation profiles were identified: students with high emotional regulation profile, students with low emotional regulation profile and students with low emotional regulation but high scores in emotional attention profile. The results indicated statistically significant differences between the emotional regulation profiles in stress appraisals and psychophysiological responses. Succinctly, students with high emotional regulation profile perceived academic environment as less threatening and showed lesser scores in stress responses. Students with low emotional regulation profile and low emo- tional regulation but high emotional attention profile showed similar scores, with the exception of sleep disorders. Briefly, physiotherapy students who had higher scores on emotional control and acceptance, perceived the academic setting in a more adaptive way and reported fewer stress responses