117 research outputs found

    Errores conceptuales institucionalizados en Matemáticas

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    A raíz de las reflexiones que surgen del análisis del actual Modelo Curricular de la Universidad de Sonora, donde el estudiante ocupa un lugar activo y protagónico en la construcción de su conocimiento y del momento de reflexión y análisis que propicia el inicio de la transición hacia un nuevo modelo curricular basado en Competencias, siendo insistente ambos en el uso de las nuevas TIC’s en los procesos de enseñanza y aprendizaje, en lo que a matemáticas se refiere, es oportuno hacer algunos señalamientos en relación, tanto en los aspectos metodológicos (el cómo enseñar), como en la precisión de los contenidos disciplinares a estudiar (el qué enseñar). En este artículo se hace un análisis parcial de estos aspectos, ejemplificándolo con uno de los conceptos fundamentales en matemáticas, desde el nivel básico hasta el superior y cómo algunos textos y más de un tipo de software matemático muy reconocidos, propician errores en la comprensión del mencionado concepto

    The stellar content of giant H II regions in NGC 7714

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    This is an electronic version of an article published in The Astrophysical Journal. García-Vargas, M.L., González-Delgado, R.M., Pérez, E., Alloin, D., Díaz, A. and E. Terlevich. The stellar content of giant H II regions in NGC 7714. The Astrophysical Journal 478 (1997): 112-12

    Metodología taller para padres de niños discapacitados en busca de un acompañamiento pedagógico

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    Este trabajo da cuenta de la implementación de una metodología taller desarrollada con enfoque sistémico de trabajo familiar y el modelo de grupo de reflexión. El trabajo se ocupa de realizar un recorrido teórico alrededor de los procesos grupales, de las características familiares y sentimientos que reconocen comunes entre los padres de familia; también se sistematiza la planeación y evaluación de cada uno de los talleres con lo que se desarrollaron las temáticas propuestas por los padres. Por último se plantea una fase de evolución en la que se dispone de estrategias como son: el desarrollo de historia de casos, los planes caseros y entrevistas semiestructuradas; de estas se destacan los cambios en el compromiso de los padres con las tareas propuestas para el hogar y su participación en el funcionamiento del instituto

    Chemical Abundances and Ionizing Clusters of HII Regions in the LINER Galaxy NGC 4258

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    We present long-slit observations in the optical and near infrared of eight HII regions in the spiral galaxy NGC 4258. Six of the observed regions are located in the SE inner spiral arms and the other two are isolated in the northern outer arms. A detailed analysis of the physical conditions of the gas has been performed. For two of the regions, an electron temperature has been derived from the [SIII] 6312 A line. For the rest, an empirical calibration based on the red and near infrared sulphur lines has been used. The oxygen abundances derived by both methods are found to be significantly lower (by a factor of two) than previously derived by using empirical calibrations based on the optical oxygen lines. In the brightest region, 74C, the observation of a prominent feature due to Wolf-Rayet stars provides an excellent constraint over some properties of the ionizing clusters. In the light of the current evolutionary synthesis models, no consistent solution is found to explain at the same time both the WR feature characteristics and the emission line spectrum of this region. In principle, the presence of WR stars could lead to large temperature fluctuations and also to a hardening of the ionizing radiation. None of these effects are found in region 74C for which the electron temperatures found from the [SIII] 6312A and the Paschen discontinuity at 8200A are equal within the errors and the effective temperature of the ionizing radiation is estimated at around 35,300K. Both more observations of confirmed high metallicity regions and a finer metallicity grid for the evolutionary synthesis models are needed in order to understand the ionizing populations of HII regions.Comment: 16 pages, 16 figures. To appear in MNRA

    Neural plasticity and proliferation in the generation of antidepressant effects: hippocampal implication

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    It is widely accepted that changes underlying depression and antidepressant-like effects involve not only alterations in the levels of neurotransmitters as monoamines and their receptors in the brain, but also structural and functional changes far beyond. During the last two decades, emerging theories are providing new explanations about the neurobiology of depression and the mechanism of action of antidepressant strategies based on cellular changes at the CNS level. The neurotrophic/plasticity hypothesis of depression, proposed more than a decade ago, is now supported by multiple basic and clinical studies focused on the role of intracellular-signalling cascades that govern neural proliferation and plasticity. Herein, we review the state-of-the-art of the changes in these signalling pathways which appear to underlie both depressive disorders and antidepressant actions. We will especially focus on the hippocampal cellularity and plasticity modulation by serotonin, trophic factors as brain-derived neurotrophic factor (BDNF), and vascular endothelial growth factor (VEGF) through intracellular signalling pathways-cAMP, Wnt/ β -catenin, and mTOR. Connecting the classic monoaminergic hypothesis with proliferation/neuroplasticity-related evidence is an appealing and comprehensive attempt for improving our knowledge about the neurobiological events leading to depression and associated to antidepressant therapies

    Silicone-specific identification of trace polydimethylsiloxanes in wines with 2D-diffusion-ordered nuclear magnetic resonance spectroscopy (DOSY-NMR)

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    Present work stresses a novel analytical approach for increasing the specificity of standard NMR approaches for identifying polydimethylsiloxane (PDMS) and further silicone moieties in wines’ organic extracts, by including a second dimension that correlates chemical shifts with diffusion coefficients by means of pulsed-field gradient diffusion ordered spectroscopy (DOSY-NMR). Each silicone source in wines is unambiguously assigned by correlation of both local chemical environments and by a unique diffusion coefficient value, in turn related to a hydrodynamic radius (RH) that can be obtained with respect proper internal standards. Obtained PDMS diffusion coefficient values and hydrodynamic radii in wines’ extracts, in agreement with expected values, present a selectivity and specificity so far not reported, that positions DOSY-NMR spectroscopy as an alternative in oenology for controlling PDMS limits

    Reflections Magazine of the Faculty of Education. Volume 3 No. 4 July 1991

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    La formación en el afecto, en los valores, en la moral... ¿Qué mejor ámbito para su análisis e incorporación a una práctica social y pedagógica coherente con ello que la vida cotidiana?...la vida cotidiana escolar o familiar, personal o colectiva. Los afectos, y éstos como fundamento de una educación orientada hacia la formación de sujetos históricos, hombres y mujeres con responsabilidad, compromiso y conciencia sociales, corresponden a una de las formas de contacto cotidiano más importantes, especialmente por la intensidad de los sentimientos que en ellas se establecen: nos referimos a las relaciones entre sujetos. Constituyen expresiones suyas, las relaciones de amistad, el amor, pero también el adío. Aunque una valoración de tales sentimientos solo se logra mediante el análisis del contenido y la motivación — sobre todo de orden moral— de tales sentimientos, podemos afirmar, en general, siguiendo a Agnes Heller que el desarrollo de la moral, de la política, del arte y de la ciencia, es inconcebible sin grandes amores y grandes odios’’.Training in affection, in values, in morality... What better environment for its analysis and incorporation into a coherent social and pedagogical practice than daily life?... daily school or family, personal life or collective. Affections, and these as the foundation of an education oriented towards the formation of historical subjects, men and women with social responsibility, commitment and conscience, correspond to one of the most important forms of daily contact, especially due to the intensity of the feelings that in they are established: we refer to the relations between subjects. Their expressions are friendships, love, but also goodbye. Although an assessment of such feelings can only be achieved through analysis of content and motivation — especially of moral order— of such feelings, we can affirm, in general, following Agnes Heller that the development of morality, politics, art and science is inconceivable without great loves and great hates.Modalidad Presencia
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