1,990 research outputs found
El pensamiento estadístico en la planificación de lecciones de estadística por profesores de secundaria
En este artículo se analiza el discurso de cinco profesores durante la planificación de una lección sobre gráficas y medidas de tendencia central como parte de tres actividades profesionales (planificación, enseñanza y análisis de lecciones de clase) que llevan a cabo en un proyecto de desarrollo profesional enfocado a la enseñanza-aprendizaje de la estadística. En este artículo sólo se estudia la fase de planificación con el objetivo de identificar las dificultades y posibilidades que los profesores poseen para diseñar estrategias de enseñanza; también, se estudia en qué medida se reflejan los elementos de un pensamiento estadístico en la lección planificada
The Debate on the Citizenship Education in Spain: A Curricular or an Ideological Question
El escrito pretende ofrecer una documentada revisión del proceso que han seguido en nuestro país las materias relacionadas con la educación para la ciudadanía y los derechos humanos desde los momentos de su gestación, hasta el anuncio de su desaparición en el currículo escolar. Para ello se ha contemplado una amplia panorámica que, manteniendo una secuencia temporal, permite analizar la intervención de los distintos actores en cada uno de los momentos que fueron produciéndose en el «debate social» generado en torno a las materias. Pretendemos reflejar cómo cada uno de esos momentos se inscribía en un plan global diseñado para retrasar, frenar e impedir su implementación, hasta que el momento político permitiese su supresión. Un plan que respondía a los intereses de los grupos ideológicos más conservadores de la sociedad españolaThis paper aims to provide a documented review of the process followed by the subjects pertaining to Citizenship and Human Rights Education in Spain from its conception until the announcement of its disappearance from the school curriculum. In order to achieve this, we have taken a wide view which, maintaining a temporal sequence, makes it possible to analyse the intervention of the different actors at each stage of the “social debate” generated around the subject. We aim to show how each of these stages formed part of a global plan designed to slow down, delay and block its implementation until the political time was right to permit its suppression. A plan which reflects the interests of the more conservative ideological groups in Spanish society
The origin of Social Studies in the curriculum of the United States
Los historiadores vinculan el origen de los Estudios Sociales con la publicación del Informe del Comité de Estudios Sociales (CSS) de la Asociación Nacional de Educación (NEA), que Ravitch denomina «certificado de nacimiento del campo de los estudios sociales» (1987, 348). Desde su publicación en 1916, los orígenes de los Estudios Sociales han sido muy discutidos, pero en la historiografía del Área apenas se ha profundizado en lo acontecido previamente al Informe. Nuestro trabajo analiza esos momentos iniciales y su traslado al currículo nacional, en el contexto de los cambios acontecidos en ese país en el tránsito de los siglos XIX al XX. Presta especial atención a la cuestión racial, la integración y educación de los antiguos esclavos, subrayando el papel de Thomas Jesse Jones, un sociólogo que había trabajado con estudiantes afroamericanos y nativos americanos en el Instituto Hampton de Virginia y que, al presidir el Comité de Estudios Sociales, influyó decisivamente para incluir en el Informe los postulados desarrollados en el Instituto Hampton.Historians link the origin of Social Studies with the publication of the Report of the Social Studies Committee (CSS) of the National Education Association (NEA), which Ravitch calls "birth certificate of the field of social studies" (1987, 348). Since its publication in 1916, the origins of Social Studies have been much discussed, but the historiography of the Area has hardly deepened the events that occurred prior to the Report. Our work analyzes these initial moments and their transfer to the national curriculum, in the context of the changes that took place in that country in the transition from the 19th to the 20th centuries. Pay special attention to the racial issue, integration and education of former slaves underlining the role of Thomas Jesse Jones, a sociologist who had worked with African-American and Native American students at the Hampton Institute of Virginia and who would chair the Committee for Social Studies, influencing to include in the Report the postulates developed at the Hampton Institute.peerReviewe
Manejo exitoso con stent en un prematuro con síndrome de vena cava superior. Reporte de caso
El síndrome de vena cava superior en la infancia es una complicación inusual al uso de catéter venoso central en la unidad de cuidados intensivos neonatales. Otras causas en niños son la cirugía para enfermedades congénitas del corazón la cual ocupa la mayoría de los casos, y los linfomas, que constituyen la segunda causa más frecuente de obstrucción. Se describe el caso de un recién nacido prematuro de 25 semanas, con síndrome de vena cava superior secundario al uso de catéter venoso central para manejo de sepsis. Se destaca la importancia de un diagnóstico y tratamiento precoz. Así mismo, se reporta el manejo exitoso con stent para el síndrome de vena cava superior.Superior vena cava syndrome in infancy is an unusual complication of the use of central venous catheters in neonatal intensive care unit. Other causes of this syndrome in children are surgery for congenital heart disease which accounts for most of the cases, and lymphomas, that constitute the second most common cause of obstruction. We describe the case of a premature infant born at 25 weeks with superior vena cava syndrome secondary to a central venous catheter for management of sepsis. The importance of early diagnosis and treatment is highlighted. We also report the successful management with stenting for superior vena cava syndrome
Profitability in Rabbit Breeding
Rabbit production must be sustainable. One of the main bases of this sustainability is the profitability of the farms, in which improvement is achieved through the technical and economic management. These managements imply collecting production and economic data, calculating indexes, comparing results with those obtained in other farms, making decisions, and evaluating the consequences of changes. The chapter details the different steps to follow to develop the technical and economic management of the rabbit farms to improve their profitability. Templates to collect data, formulae to obtain different technical and economic indexes, results obtained in different producing countries, and possible techniques to improve profitability are shown
Uncertainty Model For Quantitative Precipitation Estimation Using Weather Radars
This paper introduces an uncertainty model for
the quantitatively estimate precipitation using weather radars.
The model considers various key aspects associated to radar
calibration, attenuation, and the tradeoff between accuracy
and radar coverage. An S-band-radar case study is presented to
illustrate particular fractional-uncertainty calculations obtained
to adjust various typical radar-calibration elements such as
antenna, transmitter, receiver, and some other general elements
included in the radar equation. This paper is based in “Guide to
the expression of Uncertainty in measurement” [1] and the results
show that the fractional uncertainty calculated by the model was
40 % for the reflectivity and 30% for the precipitation using the
Marshall Palmer Z-R relationship
Análisis económico-financiero de las cooperativas agrarias en Castilla y León
Taking into account the traditional structural weakness characterising the agrarian sector due to farmers’ scant output, associations and especially co-operatives attain special importance. Nonetheless, in numerous cases the economic and financial situation of these societies is not as strong as would be desirable. For this reason, the prime objective of this paper is to analyse the economic and financial situation of the agrarian co-operatives of Castille and León. To this end, a ratios plan was established adapted to the characteristics of the co-operatives, and applied over a sample of 66 co-operatives. Although the selected sample takes in societies from other productive sectors, results corresponding to the region’s strategic productive sub-sectors have been disaggregated: cereals, oilseeds and supplies (COS), wine production (BOD) sheep and goats (OVI) and cattle (VAC). The results show how the strong business volume of these co-operatives enables them to obtain adequate profitability despite the fact their business is almost exclusively commercial, hardly including any end-product manufacture. It is also observed how co-operatives seek to maximise the prices paid their members, reflected in the level of reserves held. This could have a negative impact on the investments these societies have to face to improve their level of product transformation.Agrarian co-operatives, Financial analysis, Ratios, Castille and León, Spain.
Microelectromechanical resonators based on an all polymer/carbon nanotube composite structural material
Carboxylated multi-wall carbon-nanotubes (CNTs) monolayers are integrated on microfabricated all-polymer micro-electromechanical systems (pMEMS) resonator bridges on glass substrates. The structural layer of the MEMS bridges is a multilayer blended conductive polymer based on
poly(3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS) to which functionalized CNT monolayers are electrostatically attached. The resonance frequency (fres) of electrostatically
actuated pMEMS bridges was measured as a function of their length (32–67 lm) for different multilayer compositions. A significant increase in fres and quality factor (Q) with the addition of CNT monolayers to the PEDOT:PSS structural material is observed, demonstrating that CNT
monolayers can be used to modulate pMEMS resonator properties.Peer ReviewedPostprint (published version
Metric-signature topological transitions in dispersive metamaterials
ABSTRACT: The metric signature topological transitions associated with the propagation of electromagnetic waves in a dispersive metamaterial with frequency-dependent and anisotropic dielectric and magnetic responses are examined in the present work. The components of the reciprocal-space metric tensor depend upon both the electric permittivity and magnetic permeability of the metamaterial, which are taken as Drude-like dispersive
models. A thorough study of the frequency dependence of the metric tensor is presented which leads to the possibility of topological transitions of the isofrequency surface determining the wave dynamics inside the medium, to a diverging photonic density of states at some range of frequencies, and to the existence of large
wave vectors’ modes propagating through the metamaterial
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