Behavioral engagement and disaffection in school activities: Exploring a model of motivational facilitators and performance outcomes

Investigaciones previas han mostrado que el control percibido, el valor de la tarea, el compromiso conductual y la desafección son determinantes personales del rendimiento académico. Sin embargo, pocas investigaciones han examinado simultáneamente estos constructos en educación secundaria. El presente estudio analizó las relaciones estructurales entre estas variables y el papel del compromiso y la desafección como mediadores de los efectos del control y el valor sobre el rendimiento. Los participantes fueron 446 estudiantes (51.3% chicas) con edades comprendidas entre 12 y 16 años que asistían a seis colegios de educación secundaria obligatoria (de 7º a 10º cursos; de 1º a 4º de ESO). Las variables se evaluaron a lo largo de nueve meses. Los resultados de los modelos de ecuaciones estructurales confirmaron las hipótesis: el control y el valor predijeron significativamente el compromiso, la desafección y el rendimiento; el compromiso y la desafección predijeron el rendimiento y mediaron parcialmente los efectos del control y el valor sobre el rendimiento. Se concluye discutiendo las implicaciones para la teoría y la práctica psicoeducativa.Previous research has shown that perceived control, task value, behavioral engagement and disaffection are personal determinants of academic performance. However, little research has simultaneously examined these constructs in secondary education. The present study analyzed the structural relationships between these variables and the role of engagement and disaffection as mediators of control and value on performance. Participants were 446 students (51.3% girls) ranging in age from 12 to 16 years attending six Spanish compulsory secondary schools (from 7th to 10th grades). The variables were assessed over a nine-month period. Structural equation models results confirmed the hypotheses: control and value significantly predicted engagement, disaffection, and performance; engagement and disaffection predicted performance and partially mediated the effects from control and value on performance. Implications for psycho-educational theory and practice are discussed.Fil: González, Antonio. Universidad de Vigo; EspañaFil: Paoloni, Paola Veronica Rita. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Donolo, Danilo Silvio. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rinaudo, María Cristina. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Sugammadex en paciente neonatal

ResumenIntroducciónLa inclusión de drogas que revierten efectivamente el bloqueo de la placa neuromuscular mejora el perfil de uso de los medicamentos que la relajan, y más aún si estos carecen de efectos adversos de importancia clínica y se pueden emplear en neonatos.ObjetivosEste artículo describe el caso de 2 pacientes pediátricos en quienes se aplicó sugammadex para la reversión de la relajación neuromuscular.MetodologíaEstudio observacional descriptivo retrospectivo con un diseño de reporte de casos.ResultadosSe describe el uso exitoso de sugammadex para la reversión del bloqueo neuromuscular inducido por rocuronio en 2 pacientes neonatos y la ausencia de eventos adversos.DiscusiónLa literatura para el uso de sugammadex en pacientes recién nacidos es poca y controvertida, lo cual no apoya su amplia prescripción en neonatología debido a la falta de estudios que aseguren su efectividad y la ausencia de efectos adversos. No existen dosis recomendadas por grupo etario y una lista de efectos adversos esperables que contraindiquen su administración. Aun así, es ideal poder disponer de medicamentos que reviertan la relajación derivada del uso de bloqueadores neuromusculares en cualquier edad, lo cual incluye a los pacientes neonatos.ConclusionesTras una dosis de sugammadex se describe la reversión del bloqueo neuromuscular en 2 pacientes neonatos, siendo esta efectiva para la restauración funcional de la placa neuromuscular. Para poder recomendar su amplio uso en recién nacidos es ideal la realización de estudios experimentales controlados.AbstractIntroductionThe inclusion of drugs that effectively reverse the neuromuscular junction blockade enhances the profile of drugs used for relaxation of the neuromuscular junction; better yet if these agents are free from any clinically important adverse effects and amenable to use in neonates.ObjectivesThis article describes a case of two pediatric patients who received Sugammadex to reverse neuromuscular relaxation.MethodologyRetrospective, descriptive, observational study designed as a case report.ResultsThis is a description of a Sugammadex successful reversal of Rocuronium-induced neuromuscular blockade in two neonates with no adverse events.DiscussionThe literature on the use of Sugammadex in newborn patients is scarce and controversial which does not contribute to a broad prescription of the drug in neonatology settings due to the shortage of studies attesting to its effectiveness and absence of adverse effects. There are no recommended doses per age group and a list of expected adverse effects to contraindicate its administration. However, the idea is to have available drugs that reverse the relaxation resulting from the use of neuromuscular blockers at any age, including neonates.ConclusionsFollowing the administration of a dose of Sugammadex the reversal of neuro-muscular blockade in neonate patients is described with effective functional recovery of the neuromuscular junction. Further experimental controlled trials are needed to recommend the use of Sugammadex in newborn babies

Stationary-state analysis of low-voltage DC grids

The optimal power flow is a classic method for alternating current networks, which can also be applied to direct current networks. However, it is needed to design new methods that guarantee convergence and global optimum. Several approximations based on Taylor series expansion linearization, recursive approximations, and convex optimization can be developed. In this chapter, we theoretically and numerically analyze approximations such as successive linear approximations, Newton-Raphson approximation, hyperbolic approximation, semidefinite programming, and second-order cone optimization for solving optimal power flow problems in direct current networks. The emphasis of the chapter is on low-voltage direct current grids (i.e., DC microgrids and DC distribution), but the ideas can be easily extended to high-power applications

Antígeno HLA y su asociación a las enfermedades

Esta investigación tuvo como objetivo principal, indagar acerca de la importancia del Sistema Mayor de Histocompatibilidad “HLA” y su asociación a las enfermedades. Así como mostrar la importancia de este sistema característicamente polimórfico de sumo interés en el área de inmunohematología, a la misma vez destacar las distintas técnicas de identificación para HLA. De igual manera se abordaron otros aspectos, tales como los tipos de HLA, la clasificación de las enfermedades, los mecanismos de asociación. El diseño estadístico de esta investigación estuvo basado en un estudio documental descriptivo, en el cual se pudo abordar cada uno de los aspectos que se propusieron. Para poder obtener la información que sustenta nuestro trabajo, utilizamos técnicas para recolectar datos como fichas bibliográficas, se analizó diversas literaturas y documentos encontrados para lograr el propósito de esta investigación Concluyendo que: El sistema HLA es el sistema más complejo y polimórfico conocido en el hombre. Del que se puede destacar su reconocida y valiosa importancia en la aceptación y rechazo de aloinjertos, del que se ha demostrado que desempeña un papel de suma importancia en la susceptibilidad a una gran cantidad de enfermedades, destacándose aquellas de carácter inmunológico o autoinmune. Aquellas enfermedades que se asocian al sistema HLA, generalmente son de etiología desconocida, presentando alteraciones de procesos inmunológicos, además que pueden presentar un agrupamiento familiar y afectar a más de un caso entre consanguíneos. Estas enfermedades se lograron clasificar en dos tipos; un grupo son las basadas en mecanismos de patogénesis y el segundo grupo se clasifica teniendo como base las características de los antígenos HLA responsables de asociació

Control de admisión multicast

In recent years there has been an increasing deployment of multicast applications, most of them oriented to multimedia. Many of these applications require a very strict quality of service in order thatthe receiver has no problems. These requirements are not possible to comply with the current Internet protocol Best-Effort. Currently, much research has been to provide quality service in a distributedmulticast communication, one of these aspects for the multicast quality service is admission control. This article analyzes aspects of admission control mainly multicast communications

Un municipio de orígen campesino.

Orígen y colonización del municipio de Nueva Guinea

Optimal Location-Reallocation of Battery Energy Storage Systems in DC Microgrids

This paper deals with the problem of optimal location and reallocation of battery energy storage systems (BESS) in direct current (dc) microgrids with constant power loads. The optimization model that represents this problem is formulated with two objective functions. The first model corresponds to the minimization of the total daily cost of buying energy in the spot market by conventional generators and the second to the minimization of the costs of the daily energy losses in all branches of the network. Both the models are constrained by classical nonlinear power flow equations, distributed generation capabilities, and voltage regulation, among others. These formulations generate a nonlinear mixed-integer programming (MINLP) model that requires special methods to be solved. A dc microgrid composed of 21-nodes with existing BESS is used for validating the proposed mathematical formula. This system allows to identify the optimal location or reallocation points for these batteries by improving the daily operative costs regarding the base cases. All the simulations are conducted via the general algebraic modeling system, widely known as the General Algebraic Modeling System (GAMS)

Optimal selection and location of bess systems in medium-voltage rural distribution networks for minimizing greenhouse gas emissions

This paper explores a methodology to locate battery energy storage systems (BESS) in rural alternating current (AC) distribution networks fed by diesel generators to minimize total greenhouse gas emissions. A mixed-integer nonlinear programming (MINLP) model is formulated to represent the problem of greenhouse gas emissions minimization, considering power balance and devices capabilities as constraints. To model the BESS systems, a linear relationship is considered between the state of charge and the power injection/consumption using a charging/discharging coefficient. The solution of the MINLP model is reached through the general algebraic modeling system by employing the BONMIN solver. Numerical results in a medium-voltage AC distribution network composed of 33 nodes and 32 branches operated with 12.66 kV demonstrate the effectiveness of including BESS systems to minimize greenhouse gas emissions in diesel generators that feeds rural distribution networks

A mixed-integer convex approximation for optimal load redistribution in bipolar DC networks with multiple constant power terminals

This paper proposes a mixed-integer convex model for optimal load-balancing in bipolar DC networks while considering multiple constant power terminals. The proposed convex model combines the Branch and Cut method with interior point optimization to solve the problem of optimal load balancing in bipolar DC networks. Additionally, the proposed convex model guarantees that global optimum of the problem is found, which ensures minimal power losses in the bipolar DC distribution grid branches, as the total monopolar load consumption has been balanced at the substation's terminals. In addition, an optimal load balancing improves the voltage profiles due to current redistribution between the positive and negative poles. Numerical results in the 21- and 85-bus test feeders and a comparison with three metaheuristic techniques show the effectiveness of the proposed convex model in reducing the total grid imbalance while minimizing the power losses and improving the voltage profiles

On the mathematical modeling for optimal selecting of calibers of conductors in DC radial distribution networks: An MINLP approach

This paper addresses the problem of optimal conductor selection in direct current (DC) distribution networks with radial topology. A nonlinear mixed-integer programming model (MINLP) is developed through a branch-to-node incidence matrix. An important contribution is that the proposed MINLP model integrates a set of constraints related to the telescopic structure of the network, which allows reducing installation costs. The proposed model also includes a time-domain dependency that helps analyze the DC network under different load conditions, including renewable generation and battery energy storage systems, and different voltage regulation operative consigns. The objective function of the proposed model is made up of the total investment in conductors and the total cost of energy losses in one year of operation. These components of the objective function show multi-objective behavior. For this reason, different simulation scenarios are performed to identify their effects on the final grid configuration. An illustrative 10-nodes medium-voltage DC grid with 9 lines is used to carry out all the simulations through the General Algebraic Modeling System known as GAMS