402 research outputs found

    Risk Management in Megaprojects

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    AbstractDespite its high relevance to the success of megaprojects, risk management remains one of the least developed research issues. Risk management is a process composed of several phases. This paper is focused on the first of these phases: risk identification. Our purpose is to establish the state of the art in risk management in megaprojects, systematize the risks studied in the literature, as well as to identify potential areas of further research. To this end, a systematic review is carried out. Academic journals and conference papers published from 2000 onwards in main databases (WoK, Scopus and ABI) have been examined. A qualitative analysis has been performed by using ATLAS.ti together with a checklist. To the best of the authors’ knowledge, no previous systematic revision of papers on risk management in megaprojects has ever been carried out, although certain authors have emphasized its importance.The contribution of this research includes: a bibliometric analysis of the papers that focus on risk management in megaprojects; a systematization and classification of the risks; tw†o matrices comprised of the proposed risk categorization, first in relation to the sector studied, and second related with the different stakeholders; and an identification of gaps in the research in risk management in megaprojects.The systematization of the risks helps managers towards their identification within the megaproject, and to follow the subsequent steps in the risk management process. Moreover, the matrix developed on the transfer of risks can enable managers to analyse who would be the best partner to support each risk. Furthermore, from an academic point of view, potential areas for future lines of research are presented

    Autentificación de carne y productos cárnicos procedentes de codorniz, faisán, perdiz y pintada mediante una técnica de PCR con cebadores especie-específicos

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    Polymerase chain reaction (PCR) based on oligonucleotide primers targeting the mitochondrial 12S rRNA gene has been applied to the specific identification of meats from quail (Coturnix coturnix), pheasant (Phasianus colchicus), partridge (Alectoris spp), and guinea fowl (Numida meleagris)

    Long-term acute infections during a bovine viral diarrhea virus (BVDV) outbreak in dairy farm from Galicia (NW Spain)

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    An observational study describes an outbreak of bovine viral diarrhea virus (BVDV) in a dairy herd in Spain. The herd was subjected to a voluntary control program. In a sampling carried out in June 2020, bulk tank milk antibody levels increased compared to the previous sampling. Additionally, serum samples from 4 young heifers also tested positive for antibodies. Since the results were consistent with a recent infection, we proceeded to detect possible persistently infected (PI) animals using antigen ELISA (on serum/ear-notch samples), following the program guidelines. From this moment on, 42 animals tested positive for BVDV antigen, of which 17 were under typical acute infection (AI), 13 were deemed as PI, and eight died early on the farm before having information to determine their status. The remaining 4 showed intriguing test results consistent with a long-term AI since they tested BVDV positive in at least two antigen tests more than 3 weeks apart. Thus, one animal was positive until 80 days of age in serum, and others even for longer periods in ear-notch samples, until they finally tested negative for BVDV. Based on these results, longer follow-up may be necessary in BVDV positive animals to accurately confirm persistent infectionS

    A Compact raster lensless microscope based on a microdisplay

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    Lensless microscopy requires the simplest possible configuration, as it uses only a light source, the sample and an image sensor. The smallest practical microscope is demonstrated here. In contrast to standard lensless microscopy, the object is located near the lighting source. Raster optical microscopy is applied by using a single-pixel detector and a microdisplay. Maximum resolution relies on reduced LED size and the position of the sample respect the microdisplay. Contrarily to other sort of digital lensless holographic microscopes, light backpropagation is not required to reconstruct the images of the sample. In a mm-high microscope, resolutions down to 800 nm have been demonstrated even when measuring with detectors as large as 138 μm × 138 μm, with field of view given by the display size. Dedicated technology would shorten measuring time

    Competitive evolution of the fine contrast modulation and CuPt ordering in InGaP/GaAs layers

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    We use transmission electron microscopy to characterize the morphology of InGaP epitaxial layers grown by metal‐organic vapor‐phase epitaxy over misoriented GaAs (001) substrates, with a cutoff angle in a range from 0° to 25°. The occurrence of phase separation and CuPt‐type ordered superstructures has been observed. The most ordered configuration has been found to appear in layers grown on 2° off substrates, and the strength of order decreases with increasing the misorientation angle beyond α=2°. Conversely, whereas the phase separation is less evident in the layer grown at 2°, the sample grown with a misorientation of 25° exhibits the most phase separated configuration. The completion between these two phenomena is discussed depending on the misorientation angle

    Rural tourism as diversification strategy: determinants and performance in Galicia.

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    Determinants and performance of diversification strategy have been approached frequently in the literature. Nevertheless, there are only a few studies that analyze the diversification in sectors where the impulse to diversify is not strictly economic, but political or social. Diversification of agricultural and farm activity towards the tourism in Galicia is a clear example. The aim of this paper is to determine the factors that motivate holders of farmers to initiating a strategy of diversification towards the tourism, as well as the dimensions of the managerial relevant results for the owners who diversify. Results of the analysis on a representative sample of rural tourism establishments of Galicia indicate the multidimensional and heterogeneity of the analyzed constructs. Social motivations acquire prominence, in the same way that subjective measures of performance related to the improvement of the environment and customer orientation.Diversification, rural tourism, agrarian activity, determinant factors of diversifica

    Extending the substrate scope in the hydrogenation of unfunctionalized tetrasubstituted olefins with Ir-P stereogenic aminophosphine-oxazoline catalysts

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    Air stable and readily available Ir-catalyst precursors modified with MaxPHOX-type ligands have been successfully applied in the challenging asymmetric hydrogenation of tetrasubstituted olefins under mild reaction conditions. Gratifyingly, these catalyst precursors are not only able to efficiently hydrogenate a range of indene derivatives (ee's up to 96%) but also 1,2-dihydro-napthalene derivatives and acyclic olefins (ee's up to 99%), which both constitute the most challenging substrates for this transformation

    Active gating as a method to inhibit the crosstalk of Single Photon Avalanche Diodes in a shared well

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    This work presents low noise readout circuits for silicon pixel detectors based on Geiger mode avalanche photodiodes. Geiger mode avalanche photodiodes offer a high intrinsic gain as well as an excellent timing accuracy. In addition, they can be compatible with standard CMOS technologies. However, they suffer from a high intrinsic noise, which induces false counts indistinguishable from real events and represents an increase of the readout electronics area to store the false counts. We have developed new front-end electronic circuitry for Geiger mode avalanche photodiodes in a conventional 0.35 µm HV-CMOS technology based on a gated mode of operation that allows low noise operation. The performance of the pixel detector is triggered and synchronized with the particle beam thanks to the gated acquisition. The circuits allow low reverse bias overvoltage operation which also improves the noise figures. Experimental characterization of the fabricated front-end circuit is presented in this work

    Las actividades profesionales confiables: una herramienta para hacer operativo el concepto de competencia

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    La educación de profesionales de la salud ha evolucionado de un enfoque con énfasis en la adquisición de contenidos a uno vinculado al alcance de resultados predeterminados, constituidos por el desarrollo de competencias por parte de los alumnos. En este contexto, surge el concepto de Actividades profesionales confiables (APROC) como una manera de vincular las competencias a la práctica profesional cotidiana y ofrecer una herramienta que permite operativizarlas facilitando la planificación de la enseñanza. El desarrollo gradual de la competencia implica que los alumnos requieren supervisión decreciente, constituyéndose la evaluación de la práctica en una herramienta fundamental para decidir qué tan apto se encuentra un estudiante para llevar adelante una tarea determinada en un contexto concreto y con qué grado de supervisión. Las APROCs ofrecen un modelo concreto de niveles de supervisión que permiten acompañar a los alumnos en el desarrollo de su autonomía minimizando los riesgos para los pacientes
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