El lugar de la familia en la escuela

Este informe resume la primera parte del proyecto de investigación "El lugar de la familia en la escuela" que se desarrolla en la Universidad Católica de Santiago del Estero (UCSE), Departamento Académico Buenos Aires (DABA). El trabajo de campo, de corte etnográfico, realizado en una escuela católica de la zona norte  del conurbano bonaerense, permitió el hallazgo de un actor familiar que, por su presencia en la institución y por sus formas organizativas, se constituyó en unidad de análisis  para la segunda etapa del proyecto. De esa forma, el objetivo originario, que consistía en la exploración de las representaciones familiares, se transformó en el relevamiento y análisis de las formas en que las familias se construyen un lugar activo de participación en la escuela media

Manganese and zinc in acidic agricultural soils from Central Spain: Distribution and phytoavailability prediction with chemical extraction tests

The extractability and distribution of manganese (Mn) and zinc (Zn) were evaluated in acidic agricultural soils from Central Spain. Both single (0.1 M hydrochloride [HCl] and 0.05 M ethylenediaminetetraacetate [EDTA]) and sequential extraction procedures (SEP) (modified Tessier procedure and Community Bureau of Reference [BCR] protocol) were applied to 29 representative soils that belong to the Alfisol, Inceptisol, and Entisol orders. Average relative Mn extractabilities with respect to the total content (16.6% for HCl and 31.9% for EDTA) were higher than those of Zn (7.7% for HCl and 6.5% for EDTA). Manganese was mainly released in the oxide-bound phase of both SEP (33.1% for modified Tessier and 48.9% for BCR), whereas Zn was predominantly found in the residual fraction (49.1% for modified Tessier and 31.4% for BCR). Significant correlations were only found between the amounts of extractable Zn and the oxide-bound fraction in both SEP. Few relationships were established between Zn fractions extracted by the BCR procedure and those obtained with the Tessier method. Both metal concentrations in spring barley (Hordeum vulgare L., cv Beka) grown in 11 selected soils and the calculated soil/plant transfer coefficients (soil/plant concentration factor (CF), mean values of 31.2 for Mn and 196 for Zn) were poorly (or not at all) correlated with the different extracted soil fractions (single and sequential). A number of empirical equations have been obtained by regression analyses to predict the Mn and Zn uptake by barley, with soil metal forms and some soil characteristics as components (pH for Mn and organic matter for Zn). Values of R2 in the equations were relatively low (<68%). Single-extraction techniques produced worse results than SEP for the evaluation of Mn phytoavailability. The modified Tessier procedure provided better predictions of Zn uptake by plants than BCR, but not better than those obtained with the HCl extraction method

Performance comparison of scheduling algorithms for IPTV traffic over polymorphous OBS routers

Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.V. López, J. L. García-Dorado, J. A. Hernández, and J. Aracil, "Performance comparison of scheduling algorithms for IPTV traffic over polymorphous OBS routers", in ICTON Mediterranean Winter Conference, 2007. ICTON-MW 2007, p. 1-6Recent research in optical burst switched networks has proposed solutions to support subwavelength reservation for the periodic transmission of data bursts, which can coexist with conventional asynchronous bursts, bringing the polymorphous, agile and transparent optical networks (PATON) [1]. Thus, network operators can distribute IPTV channels to their customers, whereby they can use the spare bandwidth for the transmission of best-effort traffic, making use of the free gaps in between such periodic reservations. This work proposes scheduling algorithms for the transmission of periodic channels using PATON, and studies the blocking probability observed by best-effort traffic, when such scheduling algorithms are used.This work has been partially funded by the Spanish Ministry of Science and Education under the project DIOR (TEC2006-03246), and by the Comunidad Autónoma de Madrid under project e-Magerit (S-0505/TIC/000251). The authors would also like to acknowledge the support from the European Union VI Framework Programme e- Photon/ONe+ Network of Excellence (FP6-IST-027497)

Contabilidad y cobros de rentas en la Santa Capilla de San Andrés de Jaén. Dos siglos y medio tras la búsqueda de la eficiencia (1650-1900). (Accounting and income collection at the Santa Capilla de San Andrés in Jaén. Two and a half centuries in search of efficiency (1650-1900).

La Santa Capilla de San Andrés de Jaén es una institución benéfica que tiene sus orígenes en 1515 y aún pervive. Su contabilidad, establecida para la rendición de cuentas por parte del receptor, se sustentó en el método de cargo y data y en diversos libros necesarios, tales como los de hacienda, de gastos de meses o el cuaderno de no cobrados. En este trabajo, sobre la base del análisis de la enorme cantidad de datos que suministran sus cuentas entre 1650 y 1900, hemos estudiado la función de cobro de rentas del receptor y la eficiencia en el desempeño de la misma, así como la legitimación conseguida por los principales promotores de cambios en orden a su mejora. The Santa Capilla de San Andrés in Jaén is a charity institution founded in 1515 that still functions. Its accounting system was established to take the accounts to the receptor or collector. The accounting was performed by the Charge and Discharge method and besides the main book of this method it was also supported by several books, such as the book of the hacienda, the monthly expenses book and the booklet of outstanding income. In this paper, we have studied the collection function performed by the receptor on the basis of the huge amount of data provided by the account books regarding the period 1650-1900. By fulfilling this task we have devoted special attention to the efficieny with which the collection function was performed, as well as to the changes introduced to improve it and the success met in this process.Contabilidad eclesiástica, método de cargo y data, administración de rentas. Ecclesiastical accounting, Charge and Discharge method, income management.

Simple analysis and design of a new leaky-wave directional coupler in hybrid dielectric-waveguide printed-circuit technology

This paper presents a new theory to analyze and design a novel leaky-wave coupler based on a hybrid dielectric-waveguide printed-circuit technology. The analysis theory is based on a combined method of moments (MoM) geometrical optics (GO) technique, which makes use of the leaky mode complex propagation constant. This MoM-GO approach allows to easily obtain the response of the coupler, and to illustratively understand the working mechanism of the proposed structure. A coupler is designed to work at 5.5 GHz. Leaky mode results are compared with three-dimensional finite-element method simulations, showing the validity and accuracy of the new theory developed. This novel directional coupler presents interesting advantages when compared to previous wave couplersThis work was supported in part under Spanish National Project ESP2001-4546-PE and Spanish National Project TEC2004-04313-C02-02-TCM and under the Regional Séneca Project 2002PB/4/FS/02

Deficiencia de zinc en los cultivos y correctores de carencia del micronutriente

Una gran cantidad de cultivos estan afectados por la deficiencia de zinc, siendo algunos de ellos los siguientes: cereales, leguminosas, algodón y tabaco. Debido a esta deficiencia se pueden tener perdidas de hasta un 30% en la producción de cereales de grano como el maiz, el trigo o el arroz sin la aparicion de síntomas visibles de estrés en la planta. Las deficiencias mas acusadas, manifestadas con sintomas en las hojas, pueden provocar mayores pérdidas en los cultivos, e incluso pueden llevar a la pérdida total de los mismos. La aplicación al suelo de productos fertilizantes que contienen distintas formas de zinc es una práctica habitual que tiene por objeto corregir dichas deficiencias. La efectividad de estos productos depende de numerosos factores, tales como el tipo de suelo y el tipo de cultivo

Percepção dos estudantes sobre comportamento no ensino do professor e satisfação com a Educação Física: uma questão de gênero?

Este estudio analiza la satisfacción con la Educación Física (EF) y la percepción del comportamiento instructivo del profesor (CIP). Participaron 2.536 estudiantes (edad 13,7 ± 2,0). Se aplicaron dos escalas: a) escala de satisfacción con la EF; y b) escala de comportamientos instructivos del profesorado. Los resultados muestran una elevada satisfacción con la EF y la percepción de una buena frecuencia del CIP. Existen algunas diferencias significativas en función del género de los alumnos y profesores. No se produce empatía de género descrita en otros estudios: chicos y chicas perciben mayor frecuencia de comportamientos instructivos deseables cuando el profesor es mujer.Este trabalho analisa a satisfação com a educação física (EF) e a percepção do comportamento no ensino do professor. Participaram 2.536 estudantes (idade 13,77 ± 2,0). Foram aplicadas duas escalas: a) escala de satisfação com a educação física; y b) escala de comportamento no ensino dos professores. Os resultados demonstram uma alta satisfação com a EF, bem como a percepção de uma boa freqüência do comportamento no ensino do professor. Existem algumas diferenças significativas em função do gênero dos alunos e professores. Não há relação direta de simpatia de gênero encontrada em outros estudos: meninos e meninas percebem com mais frequência um comportamento no ensino do professor de maneira desejável, quando ele é uma mulher.The purposes of this study were to analyze the satisfaction with PE and the perception of the students about of the Teacher´ Instructional Behaviours. Participants were 2,536 students (13.7 ± 2.0 years old). Two scales were applied: a) the satisfaction with PE scale; and b) the scale of perception of the Teacher´ Instructional Behaviours. The results illustrate a high level of satisfaction with PE. Students perceive instructional desirable behaviours of their teachers occur frequently. The findings show some significant differences in gender. There is not empathy of gender: both boys and girls perceive more f requent instructional desirable behaviour when the teacher is female.Estudio financiado por el Ministerio Español de Ciencia y Tecnología (Proyecto código SEJ2007-67267/EDU

Utilidad de los flujos NetFlow de RedIRIS para análisis de una red académica

La tecnología Netflow se encuentra actualmente desplegada en la mayoría de los routers de las redes comerciales. Dicha tecnología permite registrar los flujos que atraviesan la red, contando el número de bytes y paquetes que se transmiten entre dos equipos, lo cual puede ser útil para diversas aplicaciones. Este trabajo muestra la utilidad y aplicabilidad a la gestión de los flujos de red. En concreto, se presenta cómo los registros de flujos de red que captura RedIRIS en los nodos autonómicos pueden resultar de interés para monitorizar redes y como herramienta de obtención de medidas de la red para su posterior análisis con múltiples fines. Para ello, se ha implementado una aplicación que accede a estos registros, previamente procesados, y muestra de forma sencilla un conjunto de medidas y estadísticas para la mayoría de las universidades conectadas a RedIRIS

El problema de la burocracia en la teoría política de Marx y Lenin

El objetivo del trabajo es comprobar si es posible superar el capitalismo y poder acceder a un nuevo sistema, al comunismo. Vamos a intentar desvelar los entresijos de esta teoría, a intentar comprender qué es aquello que se define como comunismo y, a preguntarnos si es posible acceder a él superando el capitalismo