815 resultados para ammassi galassie aloni relitti radio cluster


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La presente investigación tiene el propósito de indagar sobre la producción y el consumo radial en los buses de transporte urbano de la ciudad de Quito; sus características, encuentros y desencuentros de un problema que tiene su apuntalamiento teórico en los escenarios, mediaciones y personajes que giran en torno a ésta la dinámica cotidiana. Los medios de comunicación, y particularmente la radio, tienen “la misión” de producir a través del discurso simbólico y radiofónico; las nuevas formas de informar, entretener y divertir a su “audiencia; así como también, ordenar, disciplinar y homogeneizar a “su público”. Se muestra, por un lado, la lógica de la producción simbólica y massmediática, y por otro lado, la lógica del consumo cultural. De esta forma se visibiliza, cómo la comunicación se convierte en un campo de “batalla simbólica” por la apropiación de los sentidos, significados y significaciones. Todo esto atraviesa por el lugar y la forma que los individuos ocupen en la relación económica, social, política y simbólica, donde la comunicación adquiere su protagonismo. Al señalar que la radio juega un papel fundamental en la configuración del imaginario urbano y que el contacto cotidiano de la gente está mediado por ésta institución mediática, se establece la importancia e influencia que ejerce la radiodifusión en nuestras sensibilidades, subjetividades y biografías. En la medida que cada medio de comunicación tiene su propia lógica, se informa sobre los resultados, se intenta visibilizar la trama del problema y se plantea nuevas preguntas de investigación.

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Este trabajo se constituye en un intento por abordar el análisis crítico de algunos de los presupuestos del discurso actual (finales de la década de 1990) sobre la comunicación alternativa y popular, confrontados con dos prácticas comunicativas en radio popular y televisión comunitaria: el caso de la emisora Radio Sucumbíos en Nueva Loja – Ecuador, y el del canal de televisión Parabólica Asociación Memoria TV en Cali – Colombia. Se pretende establecer, desde las posibilidades estructurales de cada uno (entendidas como las rutinas de producción / distribución), si estos medios de comunicación son “alternativos” como lo precisa el discurso al considerarlos como factores de desarrollo, o si por el contrario, están contribuyendo sin proponérselo, a reforzar o a construir nuevas relaciones, entre ellas las de dominación. Para adentrarnos en esta lectura en particular, se recreó el conflictivo contexto en que se desarrolla cada una de estas experiencias; se examinó el discurso desde nociones específicas; y se observó la práctica comunicativa a través de géneros como el informativo, para el caso de la radio, y el magazín para el de la televisión.

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El comercio mundial tiene múltiples actores que está sumamente bien posicionados y otros que buscan nuevas estrategias para mejorar su posicionamiento. Asimismo, las diferencias entre los mercados internacionales, nacionales y/o locales son notables, mientras los unos se expanden a pasos agigantados, los otros lo hacen paso a paso. Por lo tanto, el presente trabajo tiene como objetivo fundamental determinar las estrategias que las empresas del sector de las confecciones del cluster textil de Atuntaqui pueden implementar para hacer frente a la competencia internacional. Con esta referencia, el trabajo se ha dividido en tres capítulos. El primer capítulo, está conformado por un análisis de los principales elementos conceptuales (cadena global de valor, managment dentro de la CGV y cluster industriales); seguido, se presenta un breve recuento de la industria, el comercio mundial y los principales importadores y exportadores. Luego, se analiza las tendencias globales utilizadas por los países de América Latina y el Caribe, entre los que están: plataforma de exportación, clusters y logística internacional. En el segundo capítulo, se analizan las principales estadísticas sobre el comportamiento histórico de las importaciones y exportaciones, la caracterización de las empresas, el ámbito tecnológico, los costos y gastos en los que se ha incurrido en algunos cantones y sobre el mercado laboral. Para finalizar, el tercer capítulo, cuenta con una perspectiva local de la industria en Atuntaqui, con temas, como: el “cluster” de la industria, la caracterización de las empresas, el clima de negocios, el diagnostico FODA y las principales estrategias.

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La Radio Pública HCJB, La Voz de los Andes, con su mensaje de fe en Jesucristo inicia sus transmisiones desde el Ecuador a partir de 1931. Este medio masivo alcanza en 1990 una cobertura del 60% del globo terráqueo a través de sus frecuencias AM, FM y Onda Corta. Sin embargo, a partir de la década de 1990 se da inicio a un proceso de cambios sociales con el cual surge un movimiento de ruptura en la comunicación global, que también afecta a la estructura, funcionamiento, organización de esta Radio y la convierte en un medio de comunicación local. La investigación realizada para este estudio expondrá algunas de las causas, las determinaciones y los efectos de los cambios en la comunicación de la Radio HCJB.

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The long-term stability, high accuracy, all-weather capability, high vertical resolution, and global coverage of Global Navigation Satellite System (GNSS) radio occultation (RO) suggests it as a promising tool for global monitoring of atmospheric temperature change. With the aim to investigate and quantify how well a GNSS RO observing system is able to detect climate trends, we are currently performing an (climate) observing system simulation experiment over the 25-year period 2001 to 2025, which involves quasi-realistic modeling of the neutral atmosphere and the ionosphere. We carried out two climate simulations with the general circulation model MAECHAM5 (Middle Atmosphere European Centre/Hamburg Model Version 5) of the MPI-M Hamburg, covering the period 2001–2025: One control run with natural variability only and one run also including anthropogenic forcings due to greenhouse gases, sulfate aerosols, and tropospheric ozone. On the basis of this, we perform quasi-realistic simulations of RO observables for a small GNSS receiver constellation (six satellites), state-of-the-art data processing for atmospheric profiles retrieval, and a statistical analysis of temperature trends in both the “observed” climatology and the “true” climatology. Here we describe the setup of the experiment and results from a test bed study conducted to obtain a basic set of realistic estimates of observational errors (instrument- and retrieval processing-related errors) and sampling errors (due to spatial-temporal undersampling). The test bed results, obtained for a typical summer season and compared to the climatic 2001–2025 trends from the MAECHAM5 simulation including anthropogenic forcing, were found encouraging for performing the full 25-year experiment. They indicated that observational and sampling errors (both contributing about 0.2 K) are consistent with recent estimates of these errors from real RO data and that they should be sufficiently small for monitoring expected temperature trends in the global atmosphere over the next 10 to 20 years in most regions of the upper troposphere and lower stratosphere (UTLS). Inspection of the MAECHAM5 trends in different RO-accessible atmospheric parameters (microwave refractivity and pressure/geopotential height in addition to temperature) indicates complementary climate change sensitivity in different regions of the UTLS so that optimized climate monitoring shall combine information from all climatic key variables retrievable from GNSS RO data.

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Compute grids are used widely in many areas of environmental science, but there has been limited uptake of grid computing by the climate modelling community, partly because the characteristics of many climate models make them difficult to use with popular grid middleware systems. In particular, climate models usually produce large volumes of output data, and running them usually involves complicated workflows implemented as shell scripts. For example, NEMO (Smith et al. 2008) is a state-of-the-art ocean model that is used currently for operational ocean forecasting in France, and will soon be used in the UK for both ocean forecasting and climate modelling. On a typical modern cluster, a particular one year global ocean simulation at 1-degree resolution takes about three hours when running on 40 processors, and produces roughly 20 GB of output as 50000 separate files. 50-year simulations are common, during which the model is resubmitted as a new job after each year. Running NEMO relies on a set of complicated shell scripts and command utilities for data pre-processing and post-processing prior to job resubmission. Grid Remote Execution (G-Rex) is a pure Java grid middleware system that allows scientific applications to be deployed as Web services on remote computer systems, and then launched and controlled as if they are running on the user's own computer. Although G-Rex is general purpose middleware it has two key features that make it particularly suitable for remote execution of climate models: (1) Output from the model is transferred back to the user while the run is in progress to prevent it from accumulating on the remote system and to allow the user to monitor the model; (2) The client component is a command-line program that can easily be incorporated into existing model work-flow scripts. G-Rex has a REST (Fielding, 2000) architectural style, which allows client programs to be very simple and lightweight and allows users to interact with model runs using only a basic HTTP client (such as a Web browser or the curl utility) if they wish. This design also allows for new client interfaces to be developed in other programming languages with relatively little effort. The G-Rex server is a standard Web application that runs inside a servlet container such as Apache Tomcat and is therefore easy to install and maintain by system administrators. G-Rex is employed as the middleware for the NERC1 Cluster Grid, a small grid of HPC2 clusters belonging to collaborating NERC research institutes. Currently the NEMO (Smith et al. 2008) and POLCOMS (Holt et al, 2008) ocean models are installed, and there are plans to install the Hadley Centre’s HadCM3 model for use in the decadal climate prediction project GCEP (Haines et al., 2008). The science projects involving NEMO on the Grid have a particular focus on data assimilation (Smith et al. 2008), a technique that involves constraining model simulations with observations. The POLCOMS model will play an important part in the GCOMS project (Holt et al, 2008), which aims to simulate the world’s coastal oceans. A typical use of G-Rex by a scientist to run a climate model on the NERC Cluster Grid proceeds as follows :(1) The scientist prepares input files on his or her local machine. (2) Using information provided by the Grid’s Ganglia3 monitoring system, the scientist selects an appropriate compute resource. (3) The scientist runs the relevant workflow script on his or her local machine. This is unmodified except that calls to run the model (e.g. with “mpirun”) are simply replaced with calls to "GRexRun" (4) The G-Rex middleware automatically handles the uploading of input files to the remote resource, and the downloading of output files back to the user, including their deletion from the remote system, during the run. (5) The scientist monitors the output files, using familiar analysis and visualization tools on his or her own local machine. G-Rex is well suited to climate modelling because it addresses many of the middleware usability issues that have led to limited uptake of grid computing by climate scientists. It is a lightweight, low-impact and easy-to-install solution that is currently designed for use in relatively small grids such as the NERC Cluster Grid. A current topic of research is the use of G-Rex as an easy-to-use front-end to larger-scale Grid resources such as the UK National Grid service.

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While the Cluster spacecraft were located near the high-latitude magnetopause, between 10:10 and 10:40 UT on 16 January 2004, three typical flux transfer event (FTE) signatures were observed. During this interval, simultaneous and conjugated all-sky camera measurements, recorded at Yellow River Station, Svalbard, are available at 630.0 and 557.7nm that show poleward-moving auroral forms (PMAFs), consistent with magnetic reconnection at dayside magnetopause. Simultaneous FTEs seen at the magnetopause mainly move northward, but having duskward (eastward) and tailward velocity components, roughly consistent with the observed direction of motion of the PMAFs in all-sky images. Between the PMAFs meridional keograms, extracted from the all-sky images, show intervals of lower intensity aurora which migrate equatorward just before the PMAFs intensify. This is strong evidence for an equatorward eroding and poleward moving open-closed boundary (OCB) associated with a variable magnetopause reconnection rate under variable IMF conditions. From the durations of the PMAFs we infer that the evolution time of FTEs is 5-11 minutes from its origin on magnetopause to its addition to the polar cap.

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It is known that germin, which is a marker of the onset of growth in germinating wheat, is an oxalate oxidase, and also that germins possess sequence similarity with legumin and vicilin seed storage proteins. These two pieces of information have been combined in order to generate a 3D model of germin based on the structure of vicilin and to examine the model with regard to a potential oxalate oxidase active site. A cluster of three histidine residues has been located within the conserved beta-barrel structure. While there is a relatively low level of overall sequence similarity between the model and the vicilin structures, the conservation of amino acids important in maintaining the scaffold of the beta-barrel lends confidence to the juxtaposition of the histidine residues. The cluster is similar structurally to those found in copper amine oxidase and other proteins, leading to the suggestion that it defines a metal-binding location within the oxalate oxidase active site. It is also proposed that the structural elements involved in intermolecular interactions in vicilins may play a role in oligomer formation in germin/oxalate oxidase.

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Polyethylene glycol (PEG) may be added to forage based diets rich in tannins for ruminant feeding because it binds to tannins and thus prevent the formation of potentially indigestible tannin-protein complexes. The objective of this work was to determine the in vitro biodegradation (mineralization, i.e., complete breakdown of PEG to CO2) rate of PEG. C-14-Polyethylene glycol (C-14-PEG) was added to three different tropical soils (a sandy clay loam soil, SaCL; a sandy clay soil, SaC; and a sandy loam soil, SaL) and was incubated in Bartha flasks. Free PEG and PEG bound to tannins from a tannin rich local shrub were incubated under aerobic conditions for up to 70 days. The biodegradation assay monitored the (CO2)-C-14 evolved after degradation of the labelled PEG in the soils. After incubation, the amount of (CO2)-C-14 evolved from the C-14-PEG application was low. Higher PEG mineralization values were found for the soils with higher organic matter contents (20.1 and 18.6 g organic matter/kg for SaCL and SaC, respectively) than for the SaL soil (11.9 g organic matter/kg) (P < 0.05). The extent of mineralization of PEG after 70 days of incubation in the soil was significantly lower (P < 0.05) when it was added as bound to the browse tannin than in the free form (0.040 and 0.079, respectively). (c) 2005 Elsevier B.V. All rights reserved.