5,820 research outputs found

    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

    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

    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

    The Proteome of Biologically Active Membrane Vesicles from Piscirickettsia salmonis LF-89 Type Strain Identifies Plasmid-Encoded Putative Toxins

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    Indexación: Scopus.Piscirickettsia salmonis is the predominant bacterial pathogen affecting the Chilean salmonid industry. This bacterium is the etiological agent of piscirickettsiosis, a significant fish disease. Membrane vesicles (MVs) released by P. salmonis deliver several virulence factors to host cells. To improve on existing knowledge for the pathogenicity-associated functions of P. salmonis MVs, we studied the proteome of purified MVs from the P. salmonis LF-89 type strain using multidimensional protein identification technology. Initially, the cytotoxicity of different MV concentration purified from P. salmonis LF-89 was confirmed in an in vivo adult zebrafish infection model. The cumulative mortality of zebrafish injected with MVs showed a dose-dependent pattern. Analyses identified 452 proteins of different subcellular origins; most of them were associated with the cytoplasmic compartment and were mainly related to key functions for pathogen survival. Interestingly, previously unidentified putative virulence-related proteins were identified in P. salmonis MVs, such as outer membrane porin F and hemolysin. Additionally, five amino acid sequences corresponding to the Bordetella pertussis toxin subunit 1 and two amino acid sequences corresponding to the heat-labile enterotoxin alpha chain of Escherichia coli were located in the P. salmonis MV proteome. Curiously, these putative toxins were located in a plasmid region of P. salmonis LF-89. Based on the identified proteins, we propose that the protein composition of P. salmonis LF-89 MVs could reflect total protein characteristics of this P. salmonis type strain. © 2017 Oliver, Hernández, Tandberg, Valenzuela, Lagos, Haro, Sánchez, Ruiz, Sanhueza-Oyarzún, Cortés, Villar, Artigues, Winther-Larsen, Avendaño-Herrera and Yáñez.https://www.frontiersin.org/articles/10.3389/fcimb.2017.00420/ful

    Efecto del laboreo sobre la biomasa de Eucalyptus globulus en el Suroeste de España

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    The aim of the study was to asses the plough effects in the above and below ground biomass Eucalyptus globulus plantations. At the same time the root damage was evaluated. The project was carried out in two experimental stands, three trees were chosen by stand and plought treatment. The above ground biomass was determining harvesting the tree. The coarse and fine root were evaluated in 3.6 and 0.688 m3 of soil volume, respectively. Furthermore the root damage were analized in 50 trees. Afterward the predawn leaf water potential were determining in plough and unplough trees. The total above ground biomass have not statistical differences between treatments. The coarse roots represent a high percentage of the below ground biomass and the fine root biomass is higher near the stump. The plough effect was concentrated within the 0-20 cm soil profile. In the plough assay the amount of fine root was higher in the undisturbed than in ploughed soil. Greater part of more superficial fine roots were cuted and linearly decrease the predawn leaf water potential when increase the root damage.El objetivo del estudio fue determinar los efectos del laboreo sobre la biomasa aérea y radical de los árboles, además de evaluar el daño a nivel radical que produce esta práctica en plantaciones de Eucalyptus globulus ubicados en la Provincia de Huelva. El trabajo se realizó en dos rodales y se escogieron tres árboles por tratamiento y rodal. La biomasa aérea se determinó cosechando la totalidad del árbol. Las raíces gruesas y finas se evaluaron en un volumen de suelo de 3,6 y 0,688 m3 respectivamente. Además se analizó el daño que el laboreo produce a las raíces, para ello se analizaron 50 árboles. Luego, se determinó el potencial hídrico de los árboles, tanto en el sector no laboreado como en el laboreado. La biomasa aérea total, no presenta diferencias entre los tratamientos. Las raíces gruesas representan un alto porcentaje de la biomasa subterránea y la biomasa de raíces finas es mayor en la proximidad del tocón. El efecto del laboreo se concentra en los primeros 20 cm del perfil de suelo y en los sectores no laboreados del tratamiento de laboreo hay una mayor cantidad de raíces finas que en los sectores laboreados. Las raíces finas más superficiales en su mayoría son cortadas y el potencial hídrico disminuye linealmente al aumentar el daño a las raíces

    Gaseous time projection chambers for rare event detection: Results from the T-REX project. II. Dark matter

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    As part of the T-REX project, a number of R&D and prototyping activities have been carried out during the last years to explore the applicability of Micromegas-read gaseous TPCs in rare event searches like double beta decay (DBD), axion research and low-mass WIMP searches. While in the companion paper we focus on DBD, in this paper we focus on the results regarding the search for dark matter candidates, both axions and WIMPs. Small ultra-low background Micromegas detectors are used to image the x-ray signal expected in axion helioscopes like CAST at CERN. Background levels as low as 0.8×1060.8\times 10^{-6} c keV1^{-1}cm2^{-2}s1^{-1} have already been achieved in CAST while values down to 107\sim10^{-7} c keV1^{-1}cm2^{-2}s1^{-1} have been obtained in a test bench placed underground in the Laboratorio Subterr\'aneo de Canfranc. Prospects to consolidate and further reduce these values down to 108\sim10^{-8} c keV1^{-1}cm2^{-2}s1^{-1}will be described. Such detectors, placed at the focal point of x-ray telescopes in the future IAXO experiment, would allow for 105^5 better signal-to-noise ratio than CAST, and search for solar axions with gaγg_{a\gamma} down to few 1012^{12} GeV1^{-1}, well into unexplored axion parameter space. In addition, a scaled-up version of these TPCs, properly shielded and placed underground, can be competitive in the search for low-mass WIMPs. The TREX-DM prototype, with \sim0.300 kg of Ar at 10 bar, or alternatively \sim0.160 kg of Ne at 10 bar, and energy threshold well below 1 keV, has been built to test this concept. We will describe the main technical solutions developed, as well as the results from the commissioning phase on surface. The anticipated sensitivity of this technique might reach 1044\sim10^{-44} cm2^2 for low mass (<10<10 GeV) WIMPs, well beyond current experimental limits in this mass range.Comment: Published in JCAP. New version with erratum incorporated (new figure 14

    Lessons from the operation of the "Penning-Fluorescent" TPC and prospects

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    We have recently reported the development of a new type of high-pressure Xenon time projection chamber operated with an ultra-low diffusion mixture and that simultaneously displays Penning effect and fluorescence in the near-visible region (300 nm). The concept, dubbed `Penning-Fluorescent' TPC, allows the simultaneous reconstruction of primary charge and scintillation with high topological and calorimetric fidelity

    Limited Lifespan of Fragile Regions in Mammalian Evolution

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    An important question in genome evolution is whether there exist fragile regions (rearrangement hotspots) where chromosomal rearrangements are happening over and over again. Although nearly all recent studies supported the existence of fragile regions in mammalian genomes, the most comprehensive phylogenomic study of mammals (Ma et al. (2006) Genome Research 16, 1557-1565) raised some doubts about their existence. We demonstrate that fragile regions are subject to a "birth and death" process, implying that fragility has limited evolutionary lifespan. This finding implies that fragile regions migrate to different locations in different mammals, explaining why there exist only a few chromosomal breakpoints shared between different lineages. The birth and death of fragile regions phenomenon reinforces the hypothesis that rearrangements are promoted by matching segmental duplications and suggests putative locations of the currently active fragile regions in the human genome
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