6,359 research outputs found

    Are the hosts of VLBI selected radio-AGN different to those of radio-loud AGN?

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    Recent studies have found that radio-AGN selected by radio-loudness show little difference in terms of their host galaxy properties when compared to non-AGN galaxies of similar stellar mass and redshift. Using new 1.4~GHz VLBI observations of the COSMOS field we find that approximately 49±8\pm8\% of high-mass (M >> 1010.5^{10.5} M⊙_{\odot}), high luminosity (L1.4_{1.4} >> 1024^{24} W~Hz−1^{-1}) radio-AGN possess a VLBI detected counterpart. These objects show no discernible bias towards specific stellar masses, redshifts or host properties other than what is shown by the radio-AGN population in general. Radio-AGN that are detected in VLBI observations are not special, but form a representative sample of the radio-loud AGN population.Comment: 6 pages, 4 figures, lette

    Spanish radiographers’ concerns about the COVID-19 pandemic

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    Introduction: The current outbreak of COVID-19 has caused worldwide healthcare and social emergency in which healthcare professionals were under extreme work conditions while being fearful of becoming infected or spreading the disease to their relatives. The perceived threat of COVID-19 has the potential to cause severe psychological maladjustment. The aim of the study is to explore Spanish radiographers' concerns about the COVID-19 pandemic. Methods: This study was quantitative, observational and cross-sectional. The sample was made up of 546 radiographers working in Spain during the outbreak. The instrument used for analysis was an ad hoc questionnaire with socio-demographic questions and the questionnaire on perception of threat from COVID-19 validate to spanish healthcare professionals. Results: The sample consisted of 70.1% of female, 29.7% of male and 0.2% undeclare sex participants. The results showed a high level of a perceived threat from COVID-19 (7.57 ± 0.088), furthermore we observed a high level of threat about the possibility of infecting family members (8.49 ± 0.25), patients (8.33 ± 0.086), and coworkers (8.35 ± 0.084). Furthermore, females have a higher level of a perception of threat to spread infection between patients (r = -0.136; p = 0.001) and coworkers (r = -0.118; p = 0.006), than males. Conclusion: COVID-19 pandemic is perceived as a serious threat, being especially concerned about the threat of spreading the infection to family, coworkers, and patients. The perception of risk depends partly on professionals' gender and family responsibilities. Implications for practice: Our findings suggest that it is recommended that healthcare professionals receive formation to reinforce and improve their emotional competencies for coping successfully with potentially stressful situations like COVI19 pandemic

    Short communication: Performance, intestinal permeability, and metabolic profile of calves fed a milk replacer supplemented with glutamic acid

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    The objective of this study was to evaluate the potential benefits of supplementing glutamic acid in milk replacers (MR) with respect to calf performance, intestinal permeability, and metabolism. Sixty Holstein male calves (3 ± 1.3 d old and 45 ± 5.9 kg body weight) were individually housed and fed a control MR without AA supplementation (24.8% crude protein and 19.1% fat, dry matter basis), or MR supplemented with 0.3% glutamic acid (25.1% crude protein and 20.3% fat, dry matter basis). Animals followed the same MR feeding program and were weaned at 56 d of the study. The amount of starter concentrate offered was restricted to limit the effect of concentrate intake on calf metabolism. Individual daily consumption and weekly body weight were measured, and 4 h after the morning feeding, blood samples were obtained at 14 and 35 d to determine general biochemical parameters and plasma AA concentrations. On d 10 of the study, we conducted an intestinal permeability test by including 21 g of lactulose and 4.2 g of d-mannitol as markers in the MR. We found no differences in calf performance or in intestinal permeability (measured as lactulose:mannitol ratio). Serum glucose concentration was greater in unsupplemented calves than in Glu-supplemented calves. At 14 d, the proportion of plasma Leu was greater in Glu-supplemented calves; the proportion of Ile tended to be greater in Glu-supplemented calves; and the proportion of Met tended to be greater in unsupplemented calves. We observed no other differences. Small changes occurred in AA metabolism when supplementing calf MR with 0.3% glutamic acid, without leading to improvements in calf performance or changes in intestinal permeability.info:eu-repo/semantics/publishedVersio

    Faint polarised sources in the Lockman Hole field at 1.4 GHz

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    We aim to study the nature of the faint, polarised radio source population whose source composition and redshift dependence contain information about the strength, morphology, and evolution of magnetic fields over cosmic timescales. We use a 15 pointing radio continuum L-band mosaic of the Lockman Hole, observed in full polarisation, generated from archival data of the WSRT. The data were analysed using the RM-Synthesis technique. We achieved a noise of 7 {\mu}Jy/beam in polarised intensity, with a resolution of 15''. Using infrared and optical images and source catalogues, we were able to cross-identify and determine redshifts for one third of our detected polarised sources. We detected 150 polarised sources, most of which are weakly polarised with a mean fractional polarisation of 5.4 %. With a total area of 6.5 deg^2 and a detection threshold of 6.25 {\sigma} we find 23 polarised sources per deg^2. Based on our multi wavelength analysis, we find that our sample consists of AGN only. We find a discrepancy between archival number counts and those present in our data, which we attribute to sample variance. Considering the absolute radio luminosty, to distinguish weak and strong sources, we find a general trend of increased probability to detect weak sources at low redshift and strong sources at high redshift. Further, we find an anti-correlation between fractional polarisation and redshift for our strong sources sample at z{\geq}0.6. A decrease in the fractional polarisation of strong sources with increasing redshift cannot be explained by a constant magnetic field and electron density over cosmic scales, however the changing properties of cluster environments over the cosmic timemay play an important role. Disentangling these two effects requires deeper and wider polarisation observations, and better models of the morphology and strength of cosmic magnetic fields.Comment: 17 pages, 16 figures, to be published in A&

    Variación morfológica de las especies de Astyanax, subgénero Zygogaster (Teleostei, Characidae)

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    Morphological variation of Astyanax species, subgenus Zygogaster (Teleostei, Characidae) The diverse Neotropical fish genus Astyanax inhabits a variety of aquatic environments. As with other species in this genus, the taxonomic status and phylogenetic relationships of species of this subgenus remain largely undetermined. Based on 354 individuals, we analyzed the morphological variation of four species of the subgenus Zygogaster (A. atratoensis, A. caucanus, A. filiferus, and A. magdalenae) using procrustes analysis and compared findings with two species of the sister group: subgenus Poecilurichthys (A. orthodus and A. superbus). The PCA (Principal Component Analysis) and CVA (Canonical Variates Analysis) showed morphological affinity between the subgenera and indicated variance in body depth, anterior trend of dorsal fin origin and humeral spot, depression on the dorsal surface of the skull, and ventral displacement of the orbit and snout. The variation in these structures may provide evidence supporting adaptive speciation as an alternative to speciation driven by geographical isolation

    Social participation and quality of health care: the experience of citizens' health representatives in Mexico

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    OBJETIVO: Analizar la experiencia del aval ciudadano en el sistema de salud mexicano en la mejora de los servicios de salud. METODOS: Estudio de corte cualitativo en ocho estados de México en 2008. Se evaluaron diferentes aspectos del programa nacional para mejorar la calidad de los servicios de salud. Se compara la estrategia de México con otras experiencias en América Latina. RESULTADOS: Se exponen los avances y problemas del funcionamiento del aval ciudadano, figura que promueve la participación social en salud de la población. CONCLUSIONES: El aval ciudadano es una figura con gran potencial para representar a los usuarios en los servicios de salud y transmitir sus demandas de mejora de la calidad de la atención médica.OBJETIVO: Analisar a experiência do aval ciudadano (reforço cidadão) no sistema de saúde mexicano na melhora dos serviços de saúde. MÉTODOS: Estudo de coorte qualitativo em oito estados mexicanos, em 2008. Foram avaliados diferentes aspectos do programa nacional para melhora de qualidade nos serviços de saúde. Compara-se a estratégia no México com outras experiências na América Latina. RESULTADOS: Foram expostos os avanços e problemas de funcionamento do aval ciudadano (reforço cidadão), figura que promove a participação social na saúde da população. CONCLUSÕES: O aval ciudadano (reforço cidadão) é uma figura com grande potencial para representar os usuários dos serviços de saúde e transmitir suas exigências de melhorias na qualidade da atenção médica.OBJECTIVE: This article describes the experience of the aval ciudadano "Citizens' Representative" (CR) in improving the Mexican health care system. METHODS: This is a qualitative study which took place in eight Mexican states in 2008. It evaluates different aspects of a nationwide program to increase the quality of health care services (National Crusade for Quality in Health Services). The Mexican strategy is compared with experiences in other Latin American countries. RESULTS: In this paper, there is the description of achievements and problems encountered by the CR in promoting social participation in the health of the population. CONCLUSIONS: The CR has great influence when representing health service users and passing on their demands for improvements to health care quality

    Morphological variation of Astyanax species, subgenus Zygogaster (Teleostei, Characidae)

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    Astyanax es un género diverso de peces neotropicales, cuyas especies habitan gran variedad de ambientes acuáticos. La situación taxonómica de los subgéneros y de sus especies, no difiere de la problemática que presenta el género Astyanax. Basándonos en 354 individuos, se analizó la variación morfológica de cuatro especies del subgénero Zygogaster (A. atratoensis, A. caucanus, A. filiferus y A. magdalenae) mediante un análisis morfogeométrico comparado con dos especies del grupo hermano Poecilurichthys (A. orthodus y A. superbus). El ACP (Análisis de Componentes Principales) y AVC (Análisis de Variables Canónicas) evidenciaron afinidad morfológica entre los subgéneros e indicaron varianza en la profundidad del cuerpo, tendencia anterior del origen de la aleta dorsal y mancha humeral, depresión sobre la superficie dorsal del cráneo, y desplazamiento ventral de la orbita y el hocico. La variación entre las especies indicó aislamiento del tercer infraorbital del preopérculo y protrusión del extremo ventral del maxilar. La variación en estas estructuras evidencia especiación adaptativa como posible alternativa a la especiación por aislamiento geográfico. Palabras clave: Astyanax, Characido, Morfogeometría, Disparidad, Colombia.Astyanax es un género diverso de peces neotropicales, cuyas especies habitan gran variedad de ambientes acuáticos. La situación taxonómica de los subgéneros y de sus especies, no difiere de la problemática que presenta el género Astyanax. Basándonos en 354 individuos, se analizó la variación morfológica de cuatro especies del subgénero Zygogaster (A. atratoensis, A. caucanus, A. filiferus y A. magdalenae) mediante un análisis morfogeométrico comparado con dos especies del grupo hermano Poecilurichthys (A. orthodus y A. superbus). El ACP (Análisis de Componentes Principales) y AVC (Análisis de Variables Canónicas) evidenciaron afinidad morfológica entre los subgéneros e indicaron varianza en la profundidad del cuerpo, tendencia anterior del origen de la aleta dorsal y mancha humeral, depresión sobre la superficie dorsal del cráneo, y desplazamiento ventral de la orbita y el hocico. La variación entre las especies indicó aislamiento del tercer infraorbital del preopérculo y protrusión del extremo ventral del maxilar. La variación en estas estructuras evidencia especiación adaptativa como posible alternativa a la especiación por aislamiento geográfico. Palabras clave: Astyanax, Characido, Morfogeometría, Disparidad, Colombia.The diverse Neotropical fish genus Astyanax inhabits a variety of aquatic environments. As with other species in this genus, the taxonomic status and phylogenetic relationships of species of this subgenus remain largely undetermined. Based on 354 individuals, we analyzed the morphological variation of four species of the subgenus Zygogaster (A. atratoensis, A. caucanus, A. filiferus, and A. magdalenae) using procrustes analysis and compared findings with two species of the sister group: subgenus Poecilurichthys (A. orthodus y A. superbus). The PCA (Principal Component Analysis) and CVA (Canonical Variates Analysis) showed morphological affinity between the subgenera and indicated variance in body depth, anterior trend of dorsal fin origin and humeral spot, depression on the dorsal surface of the skull, and ventral displacement of the orbit and snout. The variation in these structures may provide evidence supporting adaptive speciation as an alternative to speciation driven by geographical isolation. Key words: Astyanax, Characid fish, Morphogeometry, Disparity, Colombia

    Modelling the behaviour of microbulk Micromegas in Xenon/trimethylamine gas

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    We model the response of a state of the art micro-hole single-stage charge amplication device (`microbulk' Micromegas) in a gaseous atmosphere consisting of Xenon/trimethylamine at various concentrations and pressures. The amplifying structure, made with photo-lithographic techniques similar to those followed in the fabrication of gas electron multipliers (GEMs), consisted of a 100 um-side equilateral-triangle pattern with 50 um-diameter holes placed at its vertexes. Once the primary electrons are guided into the holes by virtue of an optimized field configuration, avalanches develop along the 50 um-height channels etched out of the original doubly copper-clad polyimide foil. In order to properly account for the strong field gradients at the holes' entrance as well as for the fluctuations of the avalanche process (that ultimately determine the achievable energy resolution), we abandoned the hydrodynamic framework, resorting to a purely microscopic description of the electron trajectories as obtained from elementary cross-sections. We show that achieving a satisfactory description needs additional assumptions about atom-molecule (Penning) transfer reactions and charge recombination to be made

    Biometry and plasmatic stress-related parameters in brill (Scophthalmus rhombus)cultured at different stocking densities.

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    The effects of the stocking density on the physiological stress and biometric features of the brill were studied. Fish (491&plusmn;20 g) were cultured at three different stocking densities: 1; 5 and 15 Kg m-2 (LSD, MSD and HSD) during 5 weeks. Survival and several biometric, feeding and plasmatic parameters were assessed. Although final weight and specific growth rate decreased in higher densities, there were not significant differences between MSD and HSD. Differences for survival rate, feed efficiency, conversion index and feed intake were not detected among treatments. The minimum HSI was found in the HSD treatment, and condition factor varied inversely regards to stocking density. Plasma cortisol and osmolality were directly related to stocking density though the former was not significantly different among treatments. Plasma lactate and glucose significantly increased while stocking density rose. Nevertheless, free fatty acids did not vary among treatments, and triglycerides only decreased in LSD. This work was supported by Interreg Project 0251_ECOAQUA_5_E, financed by the EDRF (European Regional Development Fund).www.juntadeandalucia.es/agriculturaypesca/ifapa/ecoaqua. &nbsp;Se estudiaron los efectos de la densidad de cultivo sobre el estr&eacute;s fisiol&oacute;gico y par&aacute;metros biom&eacute;tricos en el parracho. Los peces (491&plusmn;20 g) fueron cultivados a tres densidades diferentes: 1; 5 y 15 Kg m-2 (LSD, MSD y HSD) durante 5 semanas. El peso final y crecimiento decrecieron con la densidad, pero no hubo diferencias significativas entre MSD y HSD. No se detectaron diferencias significativas entre tratamientos para supervivencia, eficiencia alimentaria, &iacute;ndice de conversi&oacute;n y tasa de ingesti&oacute;n. El HIS m&iacute;nimo fue para la HSD y el factor de condici&oacute;n vari&oacute; inversamente a la densidad. La osmolalidad y el cortisol, glucosa y lactato plasm&aacute;ticos estuvieron directamente relacionados con la densidad. Sin embargo, los &aacute;cidos grasos libres no variaron entre tratamientos. Este trabajo fue apoyado por el proyecto Interreg 0251_ECOAQUA_5_E , financiado por el FEDER (Fondo Europeo de Desarrollo Regional).www.juntadeandalucia.es/agriculturaypesca/ifapa/ecoaqua.</p

    Scanner image methodology (SIM) to measure dimensions of leaves for agronomical applications

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    A scanner image methodology was used to determine plant dimensions, such as leaf area, length and width. The values obtained using SIM were compared with those recorded by the LI-COR leaf area meter. Bias, linearity, reproducibility and repeatability (R&amp;R) were evaluated for SIM. Different groups of leaves were scanned and measured. R&amp;R studies showed that, the lowest SIM’s resolution was nineteen categories. SIM’s R&amp;R ANOVA showed the method’s measurement error was not significant. In the image processing method, the color image was converted to gray scale over the green band and it was segmented using Otsu methodology. The noise produced was cleaned with a median filter. The leaf image was rotated to align the longest parallel line to y-axis or x-axis using central moments. From the centroid using directional erosions the leaf width and length were obtained and recorded.Key words: Leaf area, width, length, digital image analysis, segmentation
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