340 research outputs found
AproximaciĂłn ProteĂłmica al sĂndrome de apneas-hipopneas del sueño
Comunicaciones a congreso
Novel utility-scale photovoltaic plant electroluminescence maintenance technique by means of bidirectional power inverter controller
Nowadays, photovoltaic (PV) silicon plants dominate the growth in renewable energies generation. Utility-scale photovoltaic plants (USPVPs) have increased exponentially in size and power in the last decade and, therefore, it is crucial to develop optimum maintenance techniques. One of the most promising maintenance techniques is the study of electroluminescence (EL) images as a complement of infrared thermography (IRT) analysis. However, its high cost has prevented its use regularly up to date. This paper proposes a maintenance methodology to perform on-site EL inspections as efficiently as possible. First, current USPVP characteristics and the requirements to apply EL on them are studied. Next, an increase over the automation level by means of adding automatic elements in the current PV plant design is studied. The new elements and their configuration are explained, and a control strategy for applying this technique on large photovoltaic plants is developed. With the aim of getting on-site EL images on a real plant, a PV inverter has been developed to validate the proposed methodology on a small-scale solar plant. Both the electrical parameters measured during the tests and the images taken have been analysed. Finally, the implementation cost of the solution has been calculated and optimised. The results conclude the technical viability to perform on-site EL inspections on PV plants without the need to measure and analyse the panel defects out of the PV installation
Cosmic Microwave Background anisotropies from second order gravitational perturbations
This paper presents a complete analysis of the effects of second order
gravitational perturbations on Cosmic Microwave Background anisotropies, taking
explicitly into account scalar, vector and tensor modes. We also consider the
second order perturbations of the metric itself obtaining them, for a universe
dominated by a collision-less fluid, in the Poisson gauge, by transforming the
known results in the synchronous gauge. We discuss the resulting second order
anisotropies in the Poisson gauge, and analyse the possible relevance of the
different terms. We expect that, in the simplest scenarios for structure
formation, the main effect comes from the gravitational lensing by scalar
perturbations, that is known to give a few percent contribution to the
anisotropies at small angular scales.Comment: 15 pages, revtex, no figures. Version to be published in Phys. Rev.
Updating known distribution models for forecasting climate change impact on endangered species
To plan endangered species conservation and to design adequate management programmes, it is necessary to predict their
distributional response to climate change, especially under the current situation of rapid change. However, these
predictions are customarily done by relating de novo the distribution of the species with climatic conditions with no regard
of previously available knowledge about the factors affecting the species distribution. We propose to take advantage of
known species distribution models, but proceeding to update them with the variables yielded by climatic models before
projecting them to the future. To exemplify our proposal, the availability of suitable habitat across Spain for the endangered
Bonelli’s Eagle (Aquila fasciata) was modelled by updating a pre-existing model based on current climate and topography to
a combination of different general circulation models and Special Report on Emissions Scenarios. Our results suggested that
the main threat for this endangered species would not be climate change, since all forecasting models show that its
distribution will be maintained and increased in mainland Spain for all the XXI century. We remark on the importance of
linking conservation biology with distribution modelling by updating existing models, frequently available for endangered
species, considering all the known factors conditioning the species’ distribution, instead of building new models that are
based on climate change variables only.Ministerio de Ciencia e InnovaciĂłn and FEDER (project CGL2009-11316/BOS
Pressure-induced phase-transition sequence in CoF2: An experimental and first-principles study on the crystal, vibrational, and electronic properties
We report a complete structural study of CoF2 under pressure. Its crystal structure and vibrational and electronic properties have been studied both theoretically and experimentally using first-principles density functional theory (DFT) methods, x-ray diffraction, x-ray absorption at Co K-edge experiments, Raman spectroscopy, and optical absorption in the 0–80 GPa range. We have determined the structural phase-transition sequence in CoF2 and corresponding transition pressures. The results are similar to other transition-metal difluorides such as FeF2 but different to ZnF2 and MgF2, despite that the Co2+ size (ionic radius) is similar to Zn2+ and Mg2+. We found that the complete phase-transition sequence is tetragonal rutile (P42/mnm) → CaCl2 type (orthorhombic Pnnm) → distorted PdF2 (orthorhombic Pbca)+PdF2 (cubic Pa3¯) in coexistence → fluorite (cubic Fm3¯m) → cotunnite (orthorhombic Pnma). It was observed that the structural phase transition to the fluorite at 15 GPa involves a drastic change of coordination from sixfold octahedral to eightfold cubic with important modifications in the vibrational and electronic properties. We show that the stabilization of this high-pressure cubic phase is possible under nonhydrostatic conditions since ideal hydrostaticity would stabilize the distorted-fluorite structure (tetragonal I4/mmm) instead. Although the first rutile → CaCl2-type second-order phase transition is subtle by Raman spectroscopy, it was possible to define it through the broadening of the Eg Raman mode which is split in the CaCl2-type phase. First-principles DFT calculations are in fair agreement with the experimental Raman mode frequencies, thus providing an accurate description for all vibrational modes and elastic properties of CoF2 as a function of pressure
Reciprocal relations between workplace bullying, anxiety and vigor: A two-wave longitudinal study
Background and Objectives: Workplace bullying has been classified as an extreme social stressor in work contexts and has been repeatedly linked to several negative consequences. However, little research has examined reversed or reciprocal relations of bullying and outcomes. Design: We conducted a two-wave longitudinal study with a time lag of six months. Methods: The study sample consisted of 348 employees of the Spanish workforce. The present study examined longitudinal relationships between workplace bullying, psychological health, and well-being. On the basis of conservation of resources theory, we hypothesized that we would find reciprocal relations among study variables over time. Results: Results of cross-lagged structural equation modeling analyses supported our hypotheses. Specifically, it was found that Time 1 (T1) workplace bullying was negatively related to Time 2 (T2) vigor and positively related to T2 anxiety. Additionally, T1 anxiety and vigor had an effect on T2 workplace bullying. Conclusions: Overall, these findings support the validity of the theoretical models postulating a reciprocal bullying–outcome relationship, rather than simple one-way causal pathways approaches
Effect of different housing systems (single and group penning) on the health and welfare of commercial female rabbits
[EN] In recent decades, concern about rabbit welfare and sustainability has increased. The housing system is a very important factor for animal welfare. However, information about how different available housing types for female rabbits affect their health status is scarce, but this is an important factor for their welfare. Hence, the objective of this study was to evaluate the health status of female rabbits in five common housing systems: three different single-housing systems with distinct available surfaces and heights; a single-housing system with a platform; a collective system. Female rabbits in the collective and platform cages had greater cortisol concentrations in hair than those in the single-housing system with no platform. Haptoglobin concentrations and kit mortality rates during lactation were greater for the collective-cage female rabbits. The collective group had more culled females and more lesions than in the other groups. The main reasons for culling in all the groups were reproduction problems and presence of abscesses, and the collective group of females was the most affected. In conclusion, it appears that keeping females together in collective systems negatively affects their health status and welfare, while single-housing systems imply lower kit mortality rates during lactation and cortisol concentrations, and fewer lesions in female rabbits.This study was supported by the INIA-INTERCUN Project (CUN2014-00001-00-00) and by Universidad CEU-Cardenal Herrera (INDI16/07, INDI17/07, INDI18/08). Grants for Sara Perez Fuentes, Asuncion Munoz Silvestre and Elena Moreno Grua from Universidad CEU-Cardenal Herrera, and also for Sara Perez Fuentes from Generalitat Valenciana and FSE (ACIF/2016/085), and for Elena Moreno Grua from Ministerio de Educacion, Cultura y Deporte (FPU17/02708) are also gratefully acknowledged.PĂ©rez-Fuentes, S.; Muñoz-Silvestre, A.; Moreno Grua, E.; Martinez-Paredes, E.; Viana, D.; Selva, L.; Villagrá, A.... (2020). Effect of different housing systems (single and group penning) on the health and welfare of commercial female rabbits. Animal. 14(6):1270-1277. https://doi.org/10.1017/S1751731119003379S12701277146Archetti I, Tittarelli C, Cerioli M, Brivio R, Grilli G and Lavazza A 2008. Serum chemistry and hematology values in commercial rabbits: preliminary data from industrial farms in northern Italy. In Proceedings of the 9th World Rabbit Congress, 10–13 June 2008, Verone, Italy, pp. 1147–1152.Argente, M.-J., GarcĂa, M. de la L., Birlanga, V., & Muelas, R. (2014). Relationship between cortisol and acute phase protein concentrations in female rabbits. The Veterinary Journal, 202(1), 172-175. doi:10.1016/j.tvjl.2014.07.020Cervera C, MartĂnez-Paredes E, Machado L and Villagrá A 2017. ProducciĂłn de conejas en sistemas de alojamiento individual o colectivo en semigrupo. In Proceedings of the XLII Symposium de Cunicultura de ASESCU, 11–12 May 2017, Murcia, Spain, pp. 107–110.Dal Bosco, A., Mugnai, C., Martino, M., SzendrĹ‘, Z., Mattioli, S., Cambiotti, V., … Castellini, C. (2019). Housing Rabbit Does in a Combi System with Removable Walls: Effect on Behaviour and Reproductive Performance. Animals, 9(8), 528. doi:10.3390/ani9080528Dalle Zotte, A., Princz, Z., Matics, Z., GerencsĂ©r, Z., Metzger, S., & SzendrĹ‘, Z. (2009). Rabbit preference for cages and pens with or without mirrors. Applied Animal Behaviour Science, 116(2-4), 273-278. doi:10.1016/j.applanim.2008.08.011Machado L, Cervera C, MartĂnez-Paredes E, Paragliola F and Cano C 2016. Comportamiento y manejo de conejas en sistemas de crĂa colectiva. In Proceedings of the XLI Symposium de Cunicultura de ASESCU, 12–13 May 2016, Hondarribia, Spain, pp. 134–137.Maertens L and Buijs S 2016. Impact of housing system (cage vs. part-time housing) and floor type on rabbit doe welfare. In Proceedings of the 11th World Rabbit Congress, 15–18 June 2016, Qingdao, China, pp. 707–710.Marai, I. F. ., Habeeb, A. A. ., & Gad, A. . (2002). Rabbits’ productive, reproductive and physiological performance traits as affected by heat stress: a review. Livestock Production Science, 78(2), 71-90. doi:10.1016/s0301-6226(02)00091-xMarcato PS and Rosmini R 1986. Mammary glands. In Pathology of the rabbit and hare (eds. PS Marcato and R Rosmini ), pp. 179–186. SocietĂ Editrice Esculapio, Bologna, Italy.Masthoff, T., & Hoy, S. (2019). Investigations on the Influence of Floor Design on Dirtiness and Foot Pad Lesions in Growing Rabbits. Animals, 9(6), 354. doi:10.3390/ani9060354Mugnai, C., Dal Bosco, A., & Castellini, C. (2009). Effect of different rearing systems and pre-kindling handling on behaviour and performance of rabbit does. Applied Animal Behaviour Science, 118(1-2), 91-100. doi:10.1016/j.applanim.2009.02.007Petersen, H. H., Nielsen, J. P., & Heegaard, P. M. H. (2004). Application of acute phase protein measurements
in veterinary clinical chemistry. Veterinary Research, 35(2), 163-187. doi:10.1051/vetres:2004002Rödel, H. G., Starkloff, A., Bautista, A., Friedrich, A.-C., & Von Holst, D. (2008). Infanticide and Maternal Offspring Defence in European Rabbits under Natural Breeding Conditions. Ethology, 114(1), 22-31. doi:10.1111/j.1439-0310.2007.01447.xRödel, H. G., Starkloff, A., Seltmann, M. W., Prager, G., & von Holst, D. (2009). Causes and predictors of nest mortality in a European rabbit population. Mammalian Biology, 74(3), 198-209. doi:10.1016/j.mambio.2008.04.003Rommers, J. M., Boiti, C., De Jong, I., & Brecchia, G. (2006). Performance and behaviour of rabbit does in a group-housing system with natural mating or artificial insemination. Reproduction Nutrition Development, 46(6), 677-687. doi:10.1051/rnd:2006038Rommers, J., & De Greef, K. H. (2018). Are combi parks just as useful as regular parks for fatteners for part-time group housing of rabbit does? World Rabbit Science, 26(4), 299. doi:10.4995/wrs.2018.9587Rosell J and De La Fuente L 2008. Health and body condition of rabbit does on commercial farms. In Proceedings of the 9th World Rabbit Congress, 10–13 June 2008, Verone, Italy, pp. 1065–1069.Rosell, J., & de la Fuente, L. (2013). Assessing Ulcerative Pododermatitis of Breeding Rabbits. Animals, 3(2), 318-326. doi:10.3390/ani3020318Sánchez, J. P., de la Fuente, L. F., & Rosell, J. M. (2012). Health and body condition of lactating females on rabbit farms1. Journal of Animal Science, 90(7), 2353-2361. doi:10.2527/jas.2011-4065Segura, P., Martinez, J., Peris, B., Selva, L., Viana, D., Penades, J. R., & Corpa, J. M. (2007). Staphylococcal infections in rabbit does on two industrial farms. Veterinary Record, 160(25), 869-872. doi:10.1136/vr.160.25.869Siemsen DW, Malachowa N, Schepetkin IA, Whitney AR, Kirpotina LN, Lei B, DeLeo FR and Quinn MT 2014. Neutrophil isolation from nonhuman species. In Neutrophil methods and protocols (eds. MT Quinn and FR De Leo ), pp. 19–37. Humana Press, Totowa, NJ, USASzendrő, Z., & McNitt, J. I. (2012). Housing of rabbit does: Group and individual systems: A review. Livestock Science, 150(1-3), 1-10. doi:10.1016/j.livsci.2012.09.017Szendrő, Z., Mikó, A., Odermatt, M., Gerencsér, Z., Radnai, I., Dezséry, B., … Matics, Z. (2013). Comparison of performance and welfare of single-caged and group-housed rabbit does. Animal, 7(3), 463-468. doi:10.1017/s1751731112001760Szendrő, Z., Trocino, A., Hoy, S., Xiccato, G., Villagrá, A., & Maertens, L. (2019). A review of recent research outcomes on the housing of farmed domestic rabbits: reproducing does. World Rabbit Science, 27(1), 1. doi:10.4995/wrs.2019.10599Tallo-Parra, O., Manteca, X., Sabes-Alsina, M., Carbajal, A., & Lopez-Bejar, M. (2015). Hair cortisol detection in dairy cattle by using EIA: protocol validation and correlation with faecal cortisol metabolites. Animal, 9(6), 1059-1064. doi:10.1017/s1751731115000294Viana, D., Selva, L., Segura, P., Penadés, J. R., & Corpa, J. M. (2007). Genotypic characterization of Staphylococcus aureus strains isolated from rabbit lesions. Veterinary Microbiology, 121(3-4), 288-298. doi:10.1016/j.vetmic.2006.12.003Zomeño, C., Birolo, M., Gratta, F., Zuffellato, A., Xiccato, G., & Trocino, A. (2018). Effects of group housing system, pen floor type, and lactation management on performance and behaviour in rabbit does. Applied Animal Behaviour Science, 203, 55-63. doi:10.1016/j.applanim.2018.03.00
IAA : InformaciĂłn y actualidad astronĂłmica (22)
Sumario : Estrellas binarias: un matrimonio muy ventajoso.--
Mujeres y ciencia: rompiendo techos.--
La estrella más masiva.--
DECONSTRUCCIĂ“N Y otros ENSAYOS :
Criterios termodinámicos en la evolución de agujeros negros.--
ACTUALIDAD.--
ENTRE BASTIDORES.--
CIENCIA: PILARES E INCERTIDUMBRES. NĂşcleos de galaxias activas .--
HISTORIAS DE ASTRONOMÍA: “Serendipia” cósmica.--
El increĂble y asombroso viaje de FotĂłn. II Parte.--
ACTIVIDADES IAA.Esta revista se publica con la ayuda de la AcciĂłn Complementaria CCT005-06-00178 del Programa Nacional de Fomento de la Cultura CientĂfica y TecnolĂłgica.N
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