984 resultados para 485
Resumo:
The resolution of political conflict has led some to suggest that Northern Ireland will now face a range of social problems that have been ignored or suppressed by the Troubles. One such area is adolescent drug use. In this article, a review of a range of data sources shows that drug use, with few exceptions, has increased since the emergence of the ongoing peace process. Social and political changes and enhanced paramilitary involvement in the drugs trade appear to have somehow created an environment where drug use has flourished. In reviewing current drug policy and practice, the article highlights the lack of prevention, treatment, and harm reduction services established in Northern Ireland as a cause for concern.
Resumo:
This text presents an analysis of aggregated membership’s dynamics for Spanish trade unions, using ECVT data, as well as union memberships’ trajectories, or members’ decisions about joining the organization, permanency and responsibilities, and subsequent attrition. For the analysis of trajectories we make use of information of the records of actual memberships and the record of quitting of CCOO, and of a survey-questionnaire to a sample of leavers of the same union. This study allows us to confirm a linkage between the decision and motivations to become union member, to participate in union activities, the time of permanency, and the motives to quit the organization. We also identify five types of union members’ trajectories, indicating that, far from views that assert a monolithic structure, unions are complex organizations.
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Presently, Queens University Belfast is constructing a unique permanent magnet EBIT which grants unparalleled access to the photons from the trap region. However measurements of ions would still require their transfer through the collector to other measurement areas. To allow more representative sampling, a new in situ analyzer is proposed to be situated immediately at the collector end of the trap region. This analyzer may detect ions by expanding the radius of their cyclotron motion using electric fields until the ions strike Microsphere Plates (MSPs). It may also be possible by using trochoidal motion to detect product electrons. This is important as these have never been detected before in an EBIT. The preliminary design is described in this paper. (c) 2005 Elsevier B.V. All rights reserved.
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Nadie cuestiona que una fuente de aprendizaje es el propio ámbito de trabajo, en el que todo profesional resuelve las funciones y tareas a las que se enfrenta diariamente a partir de su formación y de su experiencia. Reconocer esta experiencia en las titulaciones de Grado es un tema aún no resuelto. Pero este reconocimiento exige un proceso de evaluación, apoyado en metodologías y herramientas fiables y válidas, a partir del cual se valide que una persona ha adquirido un determinado nivel de logro en unas competencias en el marco de una cualificación profesional determinada. A raíz de los resultados obtenidos en 2 convocatorias dirigidas al reconocimiento de la experiencia profesional en el Grado en Educación Social impartido por la UNED, este articulo lleva a cabo un análisis de carácter descriptivo y en perspectiva comparada, entre ambas ediciones (2011-12 y 2012-13), con el fin de valorar la pertinencia de este proceso y la calidad de los resultados obtenidos. Con una muestra de 421 estudiantes hemos inferido la validez del procedimiento propuesto. Además, esta realidad nos muestra cuáles son las áreas de intervención más demandadas, los puntos fuertes y débiles de estos profesionales, las competencias más y menos consolidadas de acuerdo a la titulación que se imparte, etc. Disponer de estos datos, además de favorecer el desarrollo profesional de nuestros estudiantes, aporta una información clave para perfilar mejor las competencias específicas del título, trabajar de forma coordinada y colaborativa entre el mundo académico y el profesional, a la vez que responder a un derecho de nuestros estudiantes.
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We observed a stellar occultation by Titan on 2003 November 14 from La Palma Observatory using ULTRACAM with three Sloan filters: u, g, and i (358, 487, and 758 nm, respectively). The occultation probed latitudes 2°?S and 1°?N during immersion and emersion, respectively. A prominent central flash was present in only the i filter, indicating wavelength-dependent atmospheric extinction. We inverted the light curves to obtain six lower-limit temperature profiles between 335 and 485 km (0.04 and 0.003 mb) altitude. The i profiles agreed with the temperature measured by the Huygens Atmospheric Structure Instrument [Fulchignoni, M., and 43 colleagues, 2005. Nature 438, 785 791] above 415 km (0.01 mb). The profiles obtained from different wavelength filters systematically diverge as altitude decreases, which implies significant extinction in the light curves. Applying an extinction model [Elliot, J.L., Young, L.A., 1992. Astron. J. 103, 991 1015] gave the altitudes of line of sight optical depth equal to unity: 396±7 and 401±20 km (u immersion and emersion); 354±7 and 387±7 km (g immersion and emersion); and 336±5 and 318±4 km (i immersion and emersion). Further analysis showed that the optical depth follows a power law in wavelength with index 1.3±0.2. We present a new method for determining temperature from scintillation spikes in the occulting body's atmosphere. Temperatures derived with this method are equal to or warmer than those measured by the Huygens Atmospheric Structure Instrument. Using the highly structured, three-peaked central flash, we confirmed the shape of Titan's middle atmosphere using a model originally derived for a previous Titan occultation [Hubbard, W.B., and 45 colleagues, 1993. Astron. Astrophys. 269, 541 563].
Resumo:
Anal redness in European eels Anguilla anguilla is related to the prevalence and mean abundance of the swimbladder nematode Anguillicola crassus and may provide a simple. non-invasive diagnostic tool for A. crassus infection. (C) 2003 The Fisheries Society of the British Isles.
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Gammarus spp. are traditionally viewed under the functional feeding group (FFG) concept as herbivorous 'shredders'. Although recent studies suggest that Gammarus should also be viewed as predators, this latter role remains contentious. Here, in a laboratory experiment, we objectively examine the balance between shredder and predator roles in a common freshwater species. Gammarus pulex preyed significantly on mayfly nymph, Baetis rhodani, in both the presence and absence of excess leaf material. There was no significant difference in predation where the alternative food, that is, leaf material, was present as compared to absent. Also, G. pulex shredded leaf material in the presence and absence of B. rhodani. However, shredding was significantly reduced where alternative food, that is, B. rhodani prey, was present as compared to absent. Further, G. pulex had a clear leaf species preference. Our results suggest that Gammarus function as both predators and shredders, with the balance of the two roles perhaps depending on food availability and quality. We discuss implications for the use of the FFG concept in assessing freshwater processes, and the role that Gammarus predation may play in structuring macroinvertebrate communities.
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In the absence of a firm link between individual meteorites and their asteroidal parent bodies, asteroids are typically characterized only by their light reflection properties, and grouped accordingly into classes. On 6 October 2008, a small asteroid was discovered with a flat reflectance spectrum in the 554-995nm wavelength range, and designated 2008 TC3 (refs 4-6). It subsequently hit the Earth. Because it exploded at 37km altitude, no macroscopic fragments were expected to survive. Here we report that a dedicated search along the approach trajectory recovered 47 meteorites, fragments of a single body named Almahata Sitta, with a total mass of 3.95kg. Analysis of one of these meteorites shows it to be an achondrite, a polymict ureilite, anomalous in its class: ultra-fine-grained and porous, with large carbonaceous grains. The combined asteroid and meteorite reflectance spectra identify the asteroid as F class, now firmly linked to dark carbon-rich anomalous ureilites, a material so fragile it was not previously represented in meteorite collections.
Resumo:
It has been shown that a femtosecond plasma of cluster targets is an almost isotropic source of fast ions and, hence, can be used to obtain ionographic images with a wide field of view. The spatial resolution of the resulting ionographic images is no worse than 600 nm, which corresponds to a uniquely high value of about 105 of the ratio of the field of view to the resolution. The use of 100–300-keV ion fluxes ensures the sensitivity of the method to the sample thickness of no worse than 100 nm even for samples consisting of light chemical elements (C, H). The proposed method can be used to obtain images of low-contrast biological objects, thin films, membranes, and other nanostructured objects.
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Periodic loading of 1-D metallodielectric electromagnetic bandgap (MEBG) structures has been rigorously investigated. Miniaturised and broadband MEBG structures have been produced by means of periodically loading a dipole array. A study has been carried out with regard to the loading mechanism, the number of stubs, the topology of the structure and the order of loading. Simulations have been carried out using a method of moments based software. First order uniform loading stubs have yielded a significant size reduction of the MEBG array and the bandwidth has doubled. Good agreement between simulations and measurements has been achieved. The current distribution on the proposed structure has been studied, yielding valuable insight. An interdigital topology has resulted in further miniaturisation and bandwidth enhancement. Fractal-type arrays have been produced after applying second order loading. A maximum miniaturisation of 2.5:1 has been achieved.