19 research outputs found

    Patterns of labour solidarity towards precarious workers and the unemployed in critical times in Greece, Poland and the UK

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    The purpose of this article is to examine whether and by what means traditional unions and other labour-oriented organisations engage in solidarity activities in favour of precarious workers and the unemployed. Our findings derive from qualitative data analysed from 10 in-depth interviews per country conducted as part of a large collaborative project with participants sampled from trade unions and other labour-oriented solidarity organisations based in three European national contexts: Greece, Poland, and the UK. Our aim here is to discern common features and differences in the strategies and answers given, within the three national contexts. To this end, we examine the actors engaged in labour solidarity; the value frames upon which these actions draw; the beneficiaries of their solidarity actions; the type of activities adopted mainly in favour of precarious workers and the unemployed; and their engagement in transnational labour solidarity activities

    Imaging with extended focal depth by means of the refractive light sword optical element

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    The paper presents first experiments with a refractive light sword optical element (LSOE). A refractive version of the LSOE was prepared in photoresist by gray scale photolithography. Then we examined chromatic aberrations of the produced element and compared them with those corresponding to two different lenses. For this purpose we performed two experiments, the first one where white light illumination was used and the latter one by the help of monochromatic illumination with three different wavelengths. The obtained results lead to the conclusion that the refractive LSOE does not exhibit significant chromatic aberrations and can be successfully used for imaging with extended depth of focus in polychromatic illuminationThis work was supported by Warsaw University of Technology, by National Institute of Telecommunications and by the Spanish Ministerio de Educación y Ciencia, Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (I+D+i), grant FIS2005-05020- C03-02 and FEDERS

    Imaging properties of the light sword optical element used as a contact lens in a presbyopic eye model

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    The paper analyzes the imaging properties of the light sword optical element (LSOE) applied as a contact lens to the presbyopic human eye. We performed our studies with a human eye model based on the Gullstrand parameterization. In order to quantify the discussion concerning imaging with extended depth of focus, we introduced quantitative parameters characterizing output images of optotypes obtained in numerical simulations. The quality of the images formed by the LSOE were compared with those created by a presbyopic human eye, reading glasses and a quartic inverse axicon. Then we complemented the numerical results by an experiment where a 3D scene was imaged by means of the refractive LSOE correcting an artificial eye based on the Gullstrand model. According to performed simulations and experiments the LSOE exhibits abilities for presbyopia correction in a wide range of functional vision distances.This work was supported by the Polish Ministry of Science and Higher Education under grant N N 514 149038 and by the Spanish Ministerio de Ciencia e Innovación (MICINN), grant FIS2008-03884 with complementary support from the European Social Fund implemented under the Human Capital Programme (POKL), project, “Preparation and Realization of Medical Physics Specialty.”S

    Strehl ratios characterizing optical elements designed for presbyopia compensation

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    We present results of numerical analysis of the Strehl ratio characteristics for the light sword optical element (LSOE). For comparison there were analyzed other optical imaging elements proposed for compensation of presbyopia such as the bifocal lens, the trifocal lens, the stenopeic contact lens, and elements with extended depth of focus (EDOF), such as the logarithmic and quartic axicons. The simulations were based on a human eye’s model being a simplified version of the Gullstrand model. The results obtained allow to state that the LSOE exhibits much more uniform characteristics of the Strehl ratio comparing with other known hitherto elements and therefore it could be a promising aid to compensate for the insufficient accommodation range of the human eye.This work was supported by the Polish Ministry of Science and Higher Education under grants N N 514 149038 and N N 518 378237 as well as by the European Social Fund implemented under the Human Capital Operational Programme (POKL), project: “Preparation and Realization of Medical Physics Specialty” with complementary support from the Spanish Ministerio de Ciencia e Innovación (MICINN) grant FIS2008-03884S

    Contrast transfer characteristics of the light sword optical element designed for presbyopia compensation

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    The paper discusses the abilities of the light sword optical element (LSOE) for presbyopia compensation. The imaging properties are analyzed by means of the modulation transfer functions and output images of the star resolution test. All numerical calculations are performed assuming an optical set-up simulating the presbyopic human eye and based on the Gullstrand model. In order to have a meaningful comparison we expand our study and present adequate analysis for other elements potentially useful in ophthalmology as reading glasses, bifocal lenses and axicons. According to the obtained results the LSOE can successfully realize vision with an extended depth of field. The element makes possible the compensation of an assumed defocus up to 4 dioptres. The output images formed by the LSOE are well recognizable and have acceptable qualities for near as well as far object distances

    Impact d'une administration orale d'imidaclopride sur la consolidation de la mémoire olfactive à long terme chez l'abeille domestique, Apis mellifera L.

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    * Inra Poitou-Charentes, ERIST, Route de Saintes BP 6, 86600 Lusignan (FRA) Diffusion du document : Inra Poitou-Charentes, ERIST, Route de Saintes BP 6, 86600 Lusignan (FRA) Diplôme : Maîtris

    Imaging with an extended depth of field by means of the peacock eye optical element

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    ABSTRACT: The paper presents imaging properties of the peacock eye optical element. Its abilities for imaging with an extended depth of field is illustrated experimentally in monochromatic, as well as polychromatic light. According to the obtained results the element makes it possible to maintain the acceptable resolution, contrast and brightness of output images for a wide range of defocusing
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