Proceso de enseñanza aprendizaje de los signos de agrupación: una experiencia novedosa

Como educadora en el área de la matemática trato de hacer todos mis esfuerzos en crear estrategias que puedan servir de gran utilidad a los alumnos y alumnas en el proceso de enseñanza-aprendizaje. Había estado buscando la manera de lograr que los alumnos y alumnas pudieran usar correctamente los signos de agrupación y lograba muy poco. Mientras desarrollaba el proceso de enseñanza-aprendizaje, todos supuestamente entendían y participaban de una forma o de otra; pero cuando evaluaba el conocimiento adquirido a corto plazo, no respondían de la forma esperada; lo que me causaba gran inquietud. Ante esta situación me tracé los objetivos de buscar nuevas estrategias que faciliten a los y las alumnos(as) la buena comprensión de la Matemática, y comprender que el proceso de enseñanza-aprendizaje no es estático y cerrado, sino que requiere de fuerza y voluntad. Para lograrlos diseñé una estrategia de socialización con dramatización, mediante la cual los y las alumnas representaban símbolos de agrupación y elaboré ejercicios que me permitieran ir desarrollando todo el proceso, apoyándome en los lineamientos que oferta la Propuesta Curricular de la Secretaría de Estado de Educación. Esta experiencia de aula está programada para desarrollarse en una sesión de clases de 40 minutos y está dirigida a estudiantes de nivel medio o de octavo grado. Luego del desarrollo de la experiencia se entregará una práctica con problemas a resolver. En los primeros 15 minutos se desarrollará el contenido; luego se procederá a organizar los alumnos. El maestro/a debe asegurarse de revisar el dominio de los signos operacionales (+, -, x, ÷), así como las operaciones algebraicas y el concepto de términos semejantes y conocer los nombres de los signos

Three dimensionality in the wake of the flow around a circular cylinder at Reynolds number 5000

The turbulent flow around a circular cylinder has been investigated at Re=5000Re=5000 using direct numerical simulations. Low frequency behavior, vortex undulation, vortex splitting, vortex dislocations and three dimensional flow within the wake were found to happen at this flow regime. In order to successfully capture the wake three dimensionality, different span-wise lengths were considered. It was found that a length LZ=2pDLZ=2pD was enough to capture this behavior, correctly predicting different aspects of the flow such as drag coefficient, Strouhal number and pressure and velocity distributions when compared to experimental values. Two instability mechanisms were found to coexist in the present case study: a global type instability originating in the shear layer, which shows a characteristic frequency, and a convective type instability that seems to be constantly present in the near wake. Characteristics of both types of instabilities are identified and discussed in detail. As suggested by Norberg, a resonance-type effect takes place in the vortex formation region, as the coexistence of both instability mechanisms result in distorted vortex tubes. However, vortex coherence is never lost within the wake.Peer ReviewedPostprint (author's final draft

Assessing information professionals in Dominican Republic: Are they prepared to deal with the new democratic libraries?

Current information policies in Dominican Republic include the creation and development of libraries and information systems in a more effective way than ever in the country. One of the biggest concerns regarding these new democratic and modern libraries is to analyze whether the Dominican Republic has information professionals competent enough to deal with this new information system. This paper describes a thorough study of the Librarianship and Information Science (LIS) education in the country, as a first step to find out the needs and requirements for innovation in LIS education. Some of the topics analyzed are degrees and programs (in public and private universities), number of librarians and information professionals at graduate level, continuing education, a comparative overview with Latin American and Caribbean countries and conclusions. This article will show some of the results from a series of studies intended to enhance libraries and information infrastructure in Dominican Republic.The authors want to thank all the information professionals in the Dominican Republic who attended our meetings in August 2006 for evaluating and discussing LIS education and for the valuable information they gave to us, especially: Dulce M. Nunez (PUCMM), Lucero Arboleda (INTEC) and Miriam Michel (UNIBE). We also want to thank Kate Johnson and Toni Carbo for their thoughtful comments to this paper

A ringed pole-on outflow from DO Tauri revealed by ALMA

We present new ALMA Band 6 observations including the CO (2-1) line and 1.3 mmcontinuum emission from the surroundings of the young stellar object DO Tauri. TheALMA CO molecular data show three different series of rings at different radial ve-locities. These rings have radii around 220 au and 800 au. We make individual fits tothe rings and note that their centers are aligned with DO Tauri and its optical high-velocity jet. In addition, we notice that the velocity of these structures increases withthe separation from the young star. We discuss the data under the hypothesis that therings represent velocity cuts through three outflowing shells that are possibly drivenby a wide-angle wind, dragging the environment material along a direction close to theline of sight (i= 19◦). We estimate the dynamical ages, the mass, the momentum andthe energy of each individual outflow shell and those of the whole outflow. The resultsare in agreement with those found in outflows from Class II sources. We make a roughestimate for the size of the jet/wind launching region, which needs to be of.15 au.We report the physical characteristics of DO Tauri?s disk continuum emission (almostface-on and with a projected major axis in the north-south direction) and its velocitygradient orientation (north-south), indicative of disk rotation for a 1-2 Mcentral star.Finally we show an HST [SII] image of the optical jet and report a measurement of itsorientation in the plane of the sky.Fil: Fernandez Lopez, Manuel. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Zapata Gonzalez, Luis Alberto. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Rodríguez, Luis F.. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Vazzano, María Mercedes. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Guzman, Andrés E.. National Astronomical Observatory Of Japan; JapónFil: López, Rosario. Universidad Autónoma de Barcelona. Facultad de Física. Departamento Astronomía y Meteorología; Españ

Cambios inmunohistoquímicos en proteínas de túbulo y glomérulo renal causadas por el veneno de la serpiente de cascabel (Crotalus vegrandis)

Renal damage is an important cause of death in patients who have survived the early effects of severe crotalid envenomation. Extracellular matrix of renal tissue is altered by Crotalus toxin activities. The aim of this study was to describe how cytoskeletal proteins and basal membrane components undergo substantial alterations under the action of Crotalus vegrandis crude venom and its hemorrhagic fraction (Uracoina-1) in mice. To detect the proteins in question, the immunoperoxidase method with monoclonal and polyclonal antibodies was used. Cell types within renal lesions were characterized by phenotypic identification, by means of immunohistologic analysis of marker proteins using different primary antibodies against mesangial cells, endothelial cells, cytoskeletal proteins (intermediate filament), extracellular matrix and basal membranes. Samples for morphological study by standard procedures (biotin-streptavidin-peroxidase technique) using light microscopy were processed. Positive and negative controls for each antigen tested in the staining assay were included. After crude venom and hemorrhagic fraction inoculation of mice, the disappearance of cytoskeletal vimentin and desmin and collagen proteins in the kidney was observed. In extracellular matrix and basal membranes, collagen type IV from envenomed animals tends to disappear from 24 h to 120 h after venom injection.El daño renal es una causa importante de muerte en pacientes que sobreviven a los efectos iniciales de los severos envenenamientos crotálicos. El objetivo de este estudio ha sido el describir como las proteínas del citoesqueleto y los componentes de membrana basal muestran alteraciones importantes en su manifestación, bajo la acción del veneno crudo de Crotalus vegrandis y una fracción hemorrágica (Uracoina-1) del mismo veneno ya que, la matriz extracelular del tejido renal es alterada por la actividad de estas toxinas. Para detectar las proteínas en cuestión se utilizó el método de inmunoperoxidasa con anticuerpos mono y policlonales. Los tipos celulares dentro de las lesiones renales fueron caracterizados por identificación fenotípica, por medio del análisis inmunohistoquímico de diferentes marcadores de proteínas utilizando anticuerpos primarios contra células mesangiales, endoteliales, proteínas de citoesqueleto (filamento intermedio), matriz extracelular y membrana basal. Se procesaron las muestras para estudio morfológico por procedimientos de rutina (biotina-streptavidina-peroxidasa) y se observaron por microscopía de luz. Fueron incluidos los controles negativos y positivos para cada antígeno probado, en los ensayos de tinción. Se observó también la desaparición en el citoesqueleto, de la expresión de las proteínas vimentina y desmina, luego de la inyección de veneno crudo y Uracoina-1. En la matriz extracelular y la membrana basal de los animales envenenados, la expresión del anti-colágeno Tipo IV, tiende a desaparecer después de las 24 a las 120 horas de la inyección del veneno

Citizens’ media in latin america

There are several reasons that explain why community and citizens’ media are so widespread and popular in Latin America. This chapter offers a series of short vignettes set in Colombia that describe the intricate processes that developed there since the 1920s and simultaneously elsewhere across Latin America, spreading the notion that agency and participation are everyone’s right. These vignettes highlight why understanding community and citizens’ media in Latin America requires recognizing the long history of radical politics in the region and the wide dissemination of leftist ideologies that popularized notions of popular participation and political agency as rights. The chapter also brings into dialogue the work of Peruvian scholar Rosa María Alfaro, who was instrumental in transforming communication scholarship in Latin America and is an early example of citizens’ media in Latin America. Including a translation of this key early text by Alfaro was a challenge, because the field is vast and there is so much material that has never been translated into English or published outside of Latin America. In selecting the following piece, the intention is to maintain the centrality of both theory and practice and to show how citizens’ media in Latin America cannot be understood unless we take into consideration what social movements and grassroots communities did in the region and how Latin American scholars thought about the region

Bibliografía [Cuadernos del Instituto Antonio de Nebrija de estudios sobre la Universidad. 2006, nº 9]

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Cycloidal Domains in the Magnetization Reversal Process of Ni80Fe20/Nd16Co84/Gd12Co88 Trilayers

The magnetization reversal of each individual layer in magnetic trilayers ( permalloy / Nd Co / Gd Co ) is investigated in detail with x-ray microscopy and micromagnetic calculations. Two sequential inversion mechanisms are identified. First, magnetic vortex-antivortex pairs move along the field direction while inverting the magnetization of magnetic stripes until they are pinned by defects. The vortex-antivortex displacements are reversible within a field interval which allows their controlled motion. Second, as the reversed magnetic field increases, cycloidal domains appear in the permalloy layer as a consequence of the dissociation of vortex-antivortex pairs due to pinning. The field range where magnetic vortices and antivortices are effectively guided by the stripe pattern is of the order of tens of mT for the Ni Fe layer, as estimated from the stability of cycloid domains in the sample

Estudio científico del Mihrab de la antigua mezquita de Almería

En este trabajo se realiza un estudio de los distintos materiales empleados en la construcción, tanto originales como añadidos, las distintas intervenciones rea lizadas en el Mihrab de la antigua Mezquita de Almería. El estudio de las mues tras ha permitido determinar la naturaleza de cada una de ellas, así como la exis tencia de gran cantidad de sales (clomros y sulfatos en su mayoría). Asimismo, se ha obtenido información sobre su micromorfología. porosidad, mayor o me nor grado de cristalinidad y estado de alteración. Finalmente se ha comprobado la aplicación, en época reciente, de consolidantes que han sido responsables del desprendimiento superficial