53 research outputs found

    Abedular relíctico en Sierra Nevada

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    Se da a conocer la existencia de un abedular relíctico en Sierra Nevada (Sur de España) en donde hasta la fecha solamente se conocía la existencia de dos ejemplares de Betula pendula subsp. fontqueri. Se aportan datos sobre la vegetación del valle del río Dúrcal, donde se encuentra este abedular, añadiendo recomendaciones para su conservación y gestión

    Psychological climate, sickness absence and gender

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    We examined whether the relationship between psychological climate and sickness absence is moderated by gender. We expected that this relationship would be stronger among men than among women. We tested this general hypothesis using two samples of men and women nurses (made up of 114 and 189 subjects, respectively). The results obtained supported our expectation. The three climate facets considered (support, goals orientation and rules orientation) showed a significant relationship with sickness absence in the men sample, but not in the women sample. Clima psicológico, absentismo y género. Se investigó si la relación entre clima psicológico y absentismo por enfermedad está moderada por el género de los empleados. Se esperaba que la relación fuera más fuerte en hombres que en mujeres. Esta hipótesis general se puso a prueba utilizando dos muestras de enfermeros/as formadas por 114 varones y 189 mujeres. Los resultados obtenidos respaldaron nuestra hipótesis general. Las tres dimensiones de clima consideradas (apoyo, orientación hacia objetivos y orientación hacia reglas) mostraron una relación estadísticamente significativa con absentismo en la muestra de varones, pero no en la de mujeres

    High quality InAlN single layers lattice-matched to GaN grown by molecular beam epitaxy

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    We report on properties of high quality ~60 nm thick InAlN layers nearly in-plane lattice-matched to GaN, grown on c-plane GaN-on-sapphire templates by plasma-assisted molecular beam epitaxy. Excellent crystalline quality and low surface roughness are confirmed by X-ray diffraction, transmission electron microscopy, and atomic force microscopy. High annular dark field observations reveal a periodic in-plane indium content variation (8 nm period), whereas optical measurements evidence certain residual absorption below the band-gap. The indium fluctuation is estimated to be +/- 1.2% around the nominal 17% indium content via plasmon energy oscillations assessed by electron energy loss spectroscopy with sub-nanometric spatial resolution

    Challenges influencing the safety of migrant workers in the construction industry: A qualitative study in Italy, Spain, and the UK

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    The construction industry is notoriously high risk for accidents, injuries, and deaths, particularly for non-national or migrant workers, who comprise a significant proportion of the workforce. This paper presents an international, qualitative study focused on exploring the challenges which influence the safety of migrant construction workers in Italy, Spain, and the UK. Based on a comprehensive review of the literature, we formulated two research questions about the challenges relating to safety that migrant workers face and the challenges to safety training effectively improving migrant workers’ safety behaviours. We present our template analysis of semi-structured interviews and focus groups with 88 participants from four occupational groups across all three countries. This identified commonalities and differences in interpretations of the primary challenges to migrant workers’ safety, amongst participants from the various occupational groups (workers, site supervisors, safety trainers and safety experts) in Italy, Spain, and the UK. These were associated with: increased use of subcontractors; dilution of safety standards down the supply chain; pressure to breach safety regulations on site; differing safety-related attitudes and behaviours due to national cultural differences, language barriers and issues relating to training (provision, delivery, language, content and transfer). Finally, we summarise the contributions and limitations of our study, arguing further interventions related to safety training are needed, along with ethnographic studies to explore how both macro-level and contextual factors affect safety outcomes for migrant construction workers

    Selective area growth of a- and c-plane GaN nanocolumns by molecular beam epitaxy using colloidal nanolithography

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    Selective area growth of a-plane GaN nanocolumns by molecular beam epitaxy was performed for the first time on a-plane GaN templates. Ti masks with 150 nm diameter nanoholes were fabricated by colloidal lithography, an easy, fast and cheap process capable to handle large areas. Even though colloidal lithography does not provide a perfect geometrical arrangement like e-beam lithography, it produces a very homogeneous mask in terms of nanohole diameter and density, and is used here for the first time for the selective area growth of GaN. Selective area growth of a-plane GaN nanocolumns is compared, in terms of anisotropic lateral and vertical growth rates, with GaN nanocolumns grown selectively on the c-plan

    Design of the PET–MR system for head imaging of the DREAM Project

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    NOTICE: this is the author’s version of a work that was accepted for publication in Nuclear Instruments and Methods in Physics Research Section A. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Nuclear Instruments and Methods in Physics Research Section A, Volume 702, 21 February 2013, Pages 94–97 DOI 10.1016/j.nima.2012.08.028In this paper we describe the overall design of a PET–MR system for head imaging within the framework of the DREAM Project as well as the first detector module tests. The PET system design consists of 4 rings of 16 detector modules each and it is expected to be integrated in a head dedicated radio frequency coil of an MR scanner. The PET modules are based on monolithic LYSO crystals coupled by means of optical devices to an array of 256 Silicon Photomultipliers. These types of crystals allow to preserve the scintillation light distribution and, thus, to recover the exact photon impact position with the proper characterization of such a distribution. Every module contains 4 Application Specific Integrated Circuits (ASICs) which return detailed information of several light statistical momenta. The preliminary tests carried out on this design and controlled by means of ASICs have shown promising results towards the suitability of hybrid PET–MR systems.This work was supported by the Centre for Industrial Technological Development co-funded by FEDER through the Technology Fund (DREAM Project, IDI-20110718), the Spanish Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica (I + D + I) under Grant no. FIS2010-21216-CO2-01 and the Valencian Local Government under Grant PROMETEO 2008/114.González Martínez, AJ.; Conde, P.; Hernández Hernández, L.; Herrero Bosch, V.; Moliner Martínez, L.; Monzó Ferrer, JM.; Orero Palomares, A.... (2013). Design of the PET–MR system for head imaging of the DREAM Project. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 702:94-97. https://doi.org/10.1016/j.nima.2012.08.028S949770

    Between a rock and hard place

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    Managers are installed by the organization’s stakeholders and shareholders to increase the organization’s value; at the same time, they depend on their subordinates’ acceptance to fulfill this leadership role. If the interest of the organization collides with the interest of their team, some managers act in the interest of their followers accepting potential disadvantages for their organizations and/or external stakeholders. In two experimental studies comprised mainly of German (N = 111) and US (N = 323) managers, we examined combined effects of authentic leadership, organizational identification, and self-perceived team prototypicality on managerial integrity operationalized as expressing work-related concerns to prevent organizations from harm (i.e., managerial voice). Our results show direct effects of authentic leadership and organizational identification on voice behavior across both studies. Furthermore, organizational identification increased voice for managers’ low in authentic leadership pointing at a compensation effect. Finally, leader team prototypicality decreased the effect of identification on voice for managers high in authentic leadership but increased voice for managers low in authentic leadership, but only if these managers identified with their organization. In sum, our findings complement prior research that focused mainly on safety and instrumentality concerns by emphasizing the relevance of self-related antecedents of managerial voice

    Monolithic crystals for PET devices: optical coupling optimization

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    NOTICE: this is the author’s version of a work that was accepted for publication in Nuclear Instruments and Methods in Physics Research Section A. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Nuclear Instruments and Methods in Physics Research Section A [Volume 731, 11 December 2013, Pages 288–294] DOI 10.1016/j.nima.2013.05.049[EN] In this work we present a method to efficiently collect scintillation light when using monolithic scintillator crystals. The acceptance angle of the scintillation light has been reduced by means of optical devices reducing the border effect which typically affects continuous crystals. We have applied this procedure on gamma detectors for PET systems using both position sensitive PMTs and arrays of SiPMs. In the case of using SiPMs, this approach also helps to reduce the photosensor active area. We evaluated the method using PMTs with a variety of different crystals with thicknesses ranging from 10 to 24 mm. We found that our design allows the use of crystal blocks with a thickness of up to 18 mm without degrading the spatial resolution caused by edge effects and without a significant detriment to the energy resolution. These results were compared with simulated data. The first results of monolithic LYSO crystals coupled to an array of 256 SiPMs by means of individual optical light guides are also presented.This work was supported by the Centre for Industrial Technological Development co-funded by FEDER through the Technology Fund (DREAM Project, IDI-20110718), the Spanish Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (I+D +I) under Grant no. FIS2010-21216-CO2-01 and the Valencian Local Government under Grant PROMETEO 2008/114.González Martínez, AJ.; Peiró, A.; Conde, P.; Hernández Hernández, L.; Moliner Martínez, L.; Orero Palomares, A.; Rodríguez-Álvarez, M.... (2013). Monolithic crystals for PET devices: optical coupling optimization. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 731:288-294. https://doi.org/10.1016/j.nima.2013.05.049S28829473
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