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Search Results: 1 - 10 of 8037 matches for " Raziel Acevedo álvarez "
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La percepción de los estudiantes universitarios en la medida de la competencia docente: validación de una escala
Raziel Acevedo álvarez,María José Fernández Díaz
Educación , 2004,
Abstract: El propósito de este estudio consiste en desarrollar y validar la medida de un constructo de competencia docente universitaria, utilizando un cuestionario de opinión de los estudiantes, con 30 ítems. En la muestra han participado 374 estudiantes de tres departamentos de la Universidad de Costa Rica, Sede de Guanacaste, cuyo mayor grupo está representado por estudiantes de primer ingreso (39,4%), con una edad media de 19,9 a os. Para validar el constructo propuesto se han aplicado los modelos de ecuaciones estructurales a seis factores de competencia docente universitaria, identificados como: organización, evaluación, presentación, entusiasmo, interacción y valoración global del estudiante. Las universidades interesadas en la innovación pueden utilizar estos factores para desarrollar planes de formación y mejora de sus docentes
FIABILIDAD Y VALIDEZ EN LA EVALUACIóN DOCENTE UNIVERSITARIA (RELIABILITY AND VALIDITY ASSESSMENT IN THE UNIVERSITY TEACHING)
Acevedo Alvarez Raziel,Olivares Miranda Maritza
Revista Electrónica Actualidades Investigativas en Educación , 2010,
Abstract: Resumen:El presente artículo expone una revisión bibliográfica sobre la fiabilidad y la validez de los cuestionarios de opinión estudiantil, utilizados para evaluar la competencia docente universitaria, a fin de reunir información sobre el intenso debate, su complejidad, su análisis y sobre su permanente actualidad; porque la docencia se transforma continuamente, los conocimientos y las habilidades de hoy se desactualizan ma ana. Por ello, es necesario evaluar la actividad permanentemente, pero con instrumentos que cumplan cabalmente estos dos componentes psicométricos. Sin embargo, es importante recalcar que muchas de estas evaluaciones no han sido estudiadas en profundidad y en muchos casos carecen de estudios estadísticos; de ahí nacen la gran cantidad de inconvenientes y problemas que enfrentan estas evaluaciones. Además, los cuestionarios de opinión han sido contrastados con variables individuales, olvidando que la docencia es un fenómeno multidimensional integrado por un conjunto de elementos contextuales y, de esa forma, ha de estudiarse, pues algunos de ellos pueden estar asociados a factores ajenos a la docencia universitaria.Abstract:The present article, exposes an extensive bibliographical review on the reliability and validity of the questionnaires of student opinion, to evaluate the educational university competition, to bring together information of the intense debate, of It complexity and of the permanent current importance; because the teaching transforms constant, the knowledge and today skills change tomorrow, for this reason, it is necessary to evaluate the activity, with instruments that fulfill these two component psychometrics. Nevertheless, it is important to stress that many of these evaluations have not been studied in depth and lack these analyses, of there is born the great quantity of problems that face these evaluations. In addition, the questionnaires of opinion have been resisted by individual variables, forgetting that the teaching is a multidimensional phenomenon integrated to a set of elements, not isolated and of this form they have to be studied, since some of them can be associated with other factors foreign to the university teaching.
Biomechanical energy harvesting from human motion: theory, state of the art, design guidelines, and future directions
Raziel Riemer, Amir Shapiro
Journal of NeuroEngineering and Rehabilitation , 2011, DOI: 10.1186/1743-0003-8-22
Abstract: We evaluated major motions performed during walking and identified the amount of work the body expends and the portion of recoverable energy. During walking, there are phases of the motion at the joints where muscles act as brakes and energy is lost to the surroundings. During those phases of motion, the required braking force or torque can be replaced by an electrical generator, allowing energy to be harvested at the cost of only minimal additional effort. The amount of energy that can be harvested was estimated experimentally and from literature data. Recommendations for future directions are made on the basis of our results in combination with a review of state-of-the-art biomechanical energy harvesting devices and energy conversion methods.For a device that uses center of mass motion, the maximum amount of energy that can be harvested is approximately 1 W per kilogram of device weight. For a person weighing 80 kg and walking at approximately 4 km/h, the power generation from the heel strike is approximately 2 W. For a joint-mounted device based on generative braking, the joints generating the most power are the knees (34 W) and the ankles (20 W).Our theoretical calculations align well with current device performance data. Our results suggest that the most energy can be harvested from the lower limb joints, but to do so efficiently, an innovative and light-weight mechanical design is needed. We also compared the option of carrying batteries to the metabolic cost of harvesting the energy, and examined the advantages of methods for conversion of mechanical energy into electrical energy.With the increasing use of portable electronics, such as mobile phones, global positioning systems (GPS), and laptop computers, in our daily lives, the need for mobile electrical power sources is increasing. The power demand for the operation of these devices is typically met by batteries. However, the need to recharge batteries (or eventually to replace them) constitutes a significa
Promoción de Actitudes y Estrategias Para el Afrontamiento de la Diabetes Mellitus y la Hipertensión Arterial en un Grupo de Enfermos Crónicos de la Ciudad de Bucaramanga
álvarez,Leonardo; Rueda,Zayda; González,Lina; Acevedo,Lizeth;
Psicoperspectivas , 2010, DOI: 10.5027/psicoperspectivas-Vol9-Issue2-fulltext-118
Abstract: this study sought to determine the effects of a program aimed at developing attitudes and emotional and practical coping strategies toward diabethes mellitus and arterial hypertension in a group of chronic hospitalized patients. the study followed rolland′s psychosocial chronic illness model, was implemented during 38 weeks and used a pre-experimental design with measures before and after treatment. 65 patients, with ages between 38 and 87, participated in this study. in the first phase, emotional and practical coping strategies were developed. in the second phase, beliefs about illness were debated with patients. student′s t test showed statistically significant values, both for emotional and practical skills, as well as for beliefs. these results suggest that the program was effective, although they should be taken cautiously due to the design used.
Modelado bidimensional de la hidrodinámica y transporte de sedimento en el ca?o de marea San Pedro (Bahía de Cádiz): Implicaciones morfodinámicas
González, CJ;álvarez, ó;Reyes, J;Acevedo, A;
Ciencias marinas , 2010,
Abstract: a two-dimensional, nonlinear, finite-difference, hydrodynamic/suspended-sediment transport coupled model was applied to the san pedro tidal creek (cadiz bay, spain) to study the characteristics of the principal tidal constituents (m2, s2, k1, and o1) and sediment transport. results show a clear predominance of the semidiurnal tide, with more than 95% of the system's total energy and related currents up to 1 m s-1 in some areas. current velocity asymmetries, related to nonlinear interaction effects, are mainly flood-directed all along the creek except at the mouth, where they are influenced by morpho-bathymetric characteristics. in these areas, the local asymmetries are clearly correlated to the net transport of sediment through the creek's course, which suggests the absence of morphodynamical balance in the present creek's evolution after human interventions that have modified its natural configuration.
Valoración de la capacidad física mediante prueba ergométrica en jóvenes sanos
Reyes Sánchez,Ruth; Velarde Sosa,Ernesto; álvarez Acevedo,Eduardo;
Revista Cubana de Medicina , 2000,
Abstract: a group of 80 healthy young individuals aged 21-29 was studied by maximal bicycle test according to the protocol of the world health organization. the mean maximal tolerated load was of 140.31 w. the weight and height of the studied sample was of 71.9 kg and 173.21 cm, respectively. the maximum oxygen consumption was of 29.97 ±3.83 ml/kg/min. the mean potency was of 93.41 w/min. the double product x 10-2 was of 337.71 and the watt/kg of 1.92. the intensity of the test was applied to 93.7 % of the maximal heart rate according to age. it was obtained nomogram based on a regression analysis for working capacity that will be useful to compare other groups with similar characteristics.
Valoración de la capacidad física mediante prueba ergométrica en jóvenes sanos
Ruth Reyes Sánchez,Ernesto Velarde Sosa,Eduardo álvarez Acevedo
Revista Cubana de Medicina , 2000,
Abstract: Se estudió, mediante prueba ergométrica máxima en bicicleta y utilizando el protocolo de la OMS, un grupo de 80 jóvenes sanos, con edades comprendidas entre 21 y 29 a os. La media de la carga máxima tolerada fue de 140,31 W. El peso y la talla de la muestra estudiada fue de 71,9 Kg y 173,21 cm, respectivamente. El consumo máximo de oxígeno fue de 29,97 ± 3,83 mL/kg/min. La potencia media fue de 93,41 W/min. El doble producto x 10-2 fue de 337,71 y el watt/kg de 1,92. Se realizó la intensidad de la prueba en el 93,7 % de frecuencia cardíaca máxima según la edad. Se obtuvo un nomograma basado en un análisis de regresión para la capacidad de trabajo, que resultará útil en la comparación de otros grupos con características similares. A group of 80 healthy young individuals aged 21-29 was studied by maximal bicycle test according to the protocol of the World Health Organization. The mean maximal tolerated load was of 140.31 W. The weight and height of the studied sample was of 71.9 kg and 173.21 cm, respectively. The maximum oxygen consumption was of 29.97 ±3.83 mL/kg/min. The mean potency was of 93.41 W/min. The double product x 10-2 was of 337.71 and the Watt/kg of 1.92. The intensity of the test was applied to 93.7 % of the maximal heart rate according to age. It was obtained nomogram based on a regression analysis for working capacity that will be useful to compare other groups with similar characteristics.
Biodistribución de IgA secretora purificada de calostro humano en fluidos biológicos de ratón Balb/c
Nadine álvarez,Frank Camacho,Oscar Otero,Reinaldo Acevedo
Vaccimonitor , 2012,
Abstract: La IgA secretora humana (IgAsh) es estructural y funcionalmente liberada por el ambiente mucosal, con la capacidad de neutralizar antígenos, participa en la aglutinación y exclusión de estos y previene la adherencia de patógenos a las superficies del epitelio mucosal. En este estudio se evaluó la biodistribución de la IgAsh purificada de calostro, después de su administración por vía intranasal, en el modelo de ratón Balb/c y se determinaron losniveles de esta inmunoglobulina en diferentes fluidos biológicos mediante ELISA. Los resultados mostraron la presencia del anticuerpo en saliva de los animales del grupo que recibió la IgAsh en todos los intervalos de tiempo estudiados. En las muestras de lavado tráqueo-bronquial se obtuvo solo la presencia del anticuerpo a las2 y 3 h posteriores a la inoculación. A partir de los resultados obtenidos consideramos interesante en el futuro utilizar este modelo experimental para evaluar el papel protector de esta inmunoglobulina como candidato terapéutico frente a la infección por Mycobacterium tuberculosis
Las comunidades relictas de Gomortega keule (Gomortegaceae, Magnoliopsida) en Chile central
Sánchez álvarez, Ana,San Martín Acevedo, José
Anales del Jardín Botánico de Madrid , 1999,
Abstract: Some inventories were made in fourteen localities of Chilean températe forest with presence of Gomortega keule. All of them are situated on the west side of the Coastal Range in Central Chile. This species, the only member of the Gomortegaceae and an endemic to this área of Chile, is endangered because of habitat occupation by plantations of exotic species. In this paper, the floristic composition and ecology of these communities are described. The information about the distribution of this species is also updated. Se caracterizan florísticamente las comunidades de Gomortega keule existentes en la ladera occidental de la Cordillera de la Costa de Chile central. La riqueza florística de estas comunidades es muy elevada, con un total de 106 especies para las 14 localidades inventariadas, distribuidas en 56 familias y 83 géneros. La clara dominancia de fanerófitos (78,3%), y dentro de éstos la distribución de las distintas formas de crecimiento (17% de trepadoras y 3,8% de epífitos), condiciona tanto estructural como fisionómicamente a estas comunidades. El grupo de especies propias del bosque valdiviano es el más abundante, 42,5% de las especies, seguido de las de carácter esclerófilo típicas del Valle Central (14,2%). La conservación de G. keule, única especie de la familia Gomortegaceae, está completamente ligada al mantenimiento de estas comunidades, que en la actualidad están siendo sustituidas sistemáticamente por plantaciones forestales de especies exóticas en toda su área de distribución.
On the center of the Hurwitz graph
Yuval Hovannes Khachatryan-Raziel
Mathematics , 2015,
Abstract: For any natural number n, the Hurwitz graph $\mathcal{H}(S_n )$ has vertices corresponding to reduced words of the cycle $(1 . . . n)$ in terms of transpositions in $S_n$, and has edges corresponding to local shifts. This graph is known to be connected, and some of its graph theoretic properties, such as its radius and upper bounds on its diameter, are known. We explore further the structure of the Hurwitz Graph, in particular its center and its connection to the geometric tree graph $G_n$. Finally, the extended Hurwitz Graph is defined and its properties such as the radius, characterization of some central elements and bounds on the diameter are obtained. Part of fulfillment of the requirements for the Master's Degree.
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