3,204 research outputs found
El Portafolio en las Ciencias de la Salud: ¿Herramienta Útil o Mantra Prescindible? Revisión Narrativa
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A exposição a cães e gatos como fatores de risco para sibilância em crianças em idade pré-escolar: são os seus efeitos modificados pela remoção?
Objective: To define the relationship between current wheezing in preschoolers and exposure to dogs and cats at home, and to find out to what extent their removal modifies the associations.Methods: Previously validated questionnaires were completed by parents of 1784 preschoolers (mean age 4.08±0.8 years). Children were stratified according to the presence (20.0 %) or absence of wheezing in the previous year. Information regarding cat or dog exposure currently and during the first year of life was collected, as well as information about the removal of the pets.Results: A higher proportion of families owning a cat in the first year of the child’s life, as well as in the previous year, was found in the wheezing group. The proportion of families owning a dog was marginally higher in this group. Cat exposure was shown to be a significant risk factor when present in the first year of the child’s life (Adjusted Odds Ratio [aOR] 1.73, 95 % CI 1.04-2.88), and an even higher association was found with current exposure (aOR 2.00, 95 % CI 1.22-3.26). The association was highest (aOR 2.68, 95 % CI 1.32-5.44) among the wheezing group for the subset of families that had removed a cat from the home. Dog exposure did not appear to be a significant risk factor, neither during the first year of life (aOR 1.24, 95 % CI 0.88-1.76) nor with current ownership (aOR 1.04, 95 % CI 0.73-1.50). However, a significant association was found in the group that had removed a dog from the home (aOR 5.88, 95 % CI 2.62-13.17).Conclusions: Exposure to cat allergens is a risk factor for asthma, when exposure occurs during the first 12 months of life. However, this factor is of limited influence beyond the first year. It is likely that children who are prone to developing an allergy would benefit from control of environmental allergen exposure, including cat avoidance. Objetivo: Definir la relación entre sibilancias activas en niños en edad preescolar y su exposición a gatos y perros en el hogar, y mostrar hasta qué punto la retirada de los mismos modifica dicha asociación.Métodos: Los padres de 1784 niños en edad preescolar (media de edad 4,08 ± 0,8) cumplimentaron los cuestionarios que previamente habÃan sido validados. Se realizó una estratificación de los niños en función de la presencia (20 %) o ausencia de sibilancias en el último año. Se recogió la información relacionada con la exposición actual a gatos o perros y durante el primer año de vida, además de información respecto a la retirada de las mascotas.Resultados: En el grupo con sibilancias se encontró una mayor proporción de familias que durante el primer año de vida del niño tuvieron un gato en casa. La proporción de familias con perro era ligeramente más alta en dicho grupo. La exposición a gatos apareció como factor de riesgo significativo si el gato habÃa estado presente en el hogar durante el primer año de vida del niño (Odds Ratio ajustada [aOR] 1,73, IC 95 % 1,04 – 2,88), y se encontró una asociación incluso más alta con la exposición actual (aOR 2, IC 95 % 1,22 – 3,26). La asociación más elevada (aOR 2,68, IC 95 % 1,32 – 5,44) se encontró en el subgrupo de familias que habÃan retirado el gato del hogar. La exposición a perros no se mostró como factor de riesgo significativo, ni durante el primer año de vida (aOR 1,24, IC 95 % 0,88 – 1,76), ni en el momento actual (aOR 1,04, IC 95 % 0,73 – 1,50). Sin embargo, en el grupo que habÃa retirado el perro del hogar sà se encontró una asociación significativa (aOR 5,88, IC 95 % 2,62 – 13,17).Conclusiones: La exposición a los alergenos del gato es un factor de riesgo para el asma si dicha exposición tiene lugar en los primeros 12 meses de vida. Sin embargo este factor tiene una influencia limitada si ocurre más allá del primer año de vida. Es probable que los niños con tendencia a desarrollar alergias se beneficien del control de la exposición a alergenos medioambientales, incluyendo evitar los gatos.Objetivo: Definir a relação entre a sibilância em crianças em idade pré-escolar e a exposição doméstica a cães e gatos. Verificar até que ponto a remoção dos animais altera as associações.Metodologia: Um questionário previamente validado foi respondido por pais de 1784 crianças em idade pré-escolar (média de idade 4.08±0.8 anos). As crianças foram estratificadas relativamente à presença (20.0 %) ou ausência de sibilância no ano anterior. Foi recolhida informação sobre a exposição a cães e gatos, atualmente e no primeiro ano de vida, bem como, informação sobre a remoção desses animais domésticos.Resultados: A maior proporção de famÃlias que possuem um gato no primeiro ano de vida da criança, assim como no anterior ao estudo, foram encontradas no grupo de crianças com manifestações de sibilância. A proporção de famÃlias que possuem um cão foi ligeiramente superior neste grupo. Verificou-se que a exposição a gatos no primeiro ano de vida é um fator de risco significante (Odds Ration Ajustado [aOR] 1.73, 95 % CI 1.04-2.88), sendo a associação ainda mais forte para uma exposição atual (aOR 2.00, 95 % CI 1.22-3.26). No grupo de crianças com sibilância a associação foi maior (aOR 2.68, 95 % CI 1.32-5.44) entre o subgrupo de famÃlias que removeram o gato da habitação. A exposição a cães não pareceu ser um fator de risco significante, nem para a exposição no primeiro ano de vida (aOR 1.24, 95 % CI 0.88-1.76) nem para a exposição atual (aOR 1.04, 95 % CI 0.73-1.50). Contudo, foi encontrada uma associação significante no grupo que tinha retirado o cão da habitação (aOR 5.88, 95 % CI 2.62-13.17). Conclusões: A exposição a alergénicos de gatos é um fator de risco para a asma, quando a exposição ocorre durante o primeiro ano de vida. Contudo, esse fator é de influência limitada além do primeiro ano. É provável que as crianças que são propensas a desenvolver uma alergia beneficiem de um controlo da exposição ambiental a alergénicos, incluindo evitar o contato com gatos
Local flap reconstruction of large scalp defects
Scalp defects can have a number of origins, and their repair is dependent upon their location, size and depth. In the case of the scalp, the repair of even small defects is complicated. Local flaps are the reference for the reconstruction of such defects. Knowledge of scalp anatomy is essential for preparing these flaps, which must be based on one or two vascular pedicles to afford a large rotation angle ? thereby facilitating closure of the defect. The parietal zone is the location offering the greatest flap mobilization possibilities. We present a case involving the repair of a major pericranial frontoparietal scalp defect. A local transverse posterior transpositioning scalp flap was raised with the posterior auricular and occipital arteries as vascular pedicle. Following repositioning of the flap, a free partial-thickness skin graft from the thigh was used to cover the donor zone. A review is provided of the different techniques for the reconstruction of large scalp defects
Switched Reluctance Drives with Degraded Mode for Electric Vehicles
There are many types of electrical machines suitable for electric vehicles. Nowadays, most manufacturers and researchers tend towards two major alternatives: permanent magnet synchronous machines and induction machines. However, these are not the only competitive candidates. Reluctance machines, which have been well-known for some decades already, present some interesting advantages. For instance, switched reluctance machines are intrinsically redundant and fault-tolerant, which makes them attractive for applications in which robustness is compulsory. In this sense, switched reluctance drives can keep working even when one of their phases loses its functionality for any reason. In an electric vehicle, this would mean being able to keep driving the vehicle even after some failures, although with reduced performance (in degraded mode). In this chapter, switched reluctance drives for traction applications are analyzed, focusing on their capability to operate in degraded mode (with m-1 phases available)
Models and matheuristics for the unrelated parallel machine scheduling problem with additional resources
[EN] In this paper we analyze a parallel machine scheduling problem in which the processing of jobs on the machines requires a number of units of a scarce resource. This number depends both on the job and on the machine. The availability of resources is limited and fixed throughout the production horizon. The ob- jective considered is the minimization of the makespan. We model this problem by means of two integer linear programming problems. One of them is based on a model previously proposed in the literature. The other one, which is based on the resemblance to strip packing problems, is an original contribution of this paper. As the models presented are incapable of solving medium-sized instances to optimality, we propose three matheuristic strategies for each of these two models. The algorithms proposed are tested over an extensive computational experience. Results show that the matheuristic strategies significantly outperform the mathematical models.The authors are supported by the Spanish Ministry of Economy and Competitiveness, under project "SCHEYARD - Optimization of Scheduling Problems in Container Yards" (No. DPI2015-65895-R), partially financed with FEDER funds. Thanks are due to our colleagues Eva Vallada and Ful Villa, for their useful suggestions. Special thanks are due to three anonymous referees which have significantly contributed to the improvement of the manuscript. Apart from accompanying on-line materials, interested readers can download more contents from http://soa.iti.es/problem-instances, like the instances used, software for generating instances and all the binaries of the algorithms tested in this paper. We also provide complete solutions, full tables of results and the statistics software files to replicate all results and plots. Additional explanations are also provided in "how-to" text files.Perea Rojas Marcos, F.; Fanjul Peyró, L.; Ruiz GarcÃa, R. (2017). Models and matheuristics for the unrelated parallel machine scheduling problem with additional resources. European Journal of Operational Research. 260(2):482-493. https://doi.org/10.1016/j.ejor.2017.01.002S482493260
Reflecting on eclecticism in garden heritage: the Monforte Gardens in Valencia as a case study
Los distintos estilos históricos se analizaron y recuperaron por el revisionismo historicista y el revivalismo durante el siglo XIX. La falta de un estilo propio caracterÃstico en la época condujo al eclecticismo, una tendencia que consistÃa en fusionar diversos repertorios ornamentales. En consecuencia, el diseño ecléctico de jardines empleó estilos históricos de diversos orÃgenes. A medida que las ciudades crecÃan, los jardines suburbanos se iban integrando en la nueva trama urbana. Los Jardines de Monforte en Valencia representan un caso de estudio relevante y caracterÃstico de las grandes transformaciones del diseño y desarrollo de jardines del siglo XIX. Lo más significativo son los recursos y estrategias de diseño introducidos en el diseño original por Sebastián Monléon y, posteriormente, por Javier de Winthuysen, como demuestra esta investigación, que incluye un nuevo trazado exhaustivo del jardÃn. Los Jardines de Monforte representan un ejemplo de diseño ecléctico de jardinerÃa urbana en el que las diferentes partes mantienen su independencia sin perder un concepto global unitario. Aunque tradicionalmente se han considerado jardines neoclásicos, esta investigación defiende que deben considerarse propiamente jardines románticos eclécticos.Precedent historic styles were analysed and recovered by historicist revisionism and revivalism during the nineteenth century. The lack of a style of its century lead to eclecticism, a trend that involved merging diverse ornamental repertories. Accordingly, eclectic garden design emp333loyed historic styles of different origins. As the cities grew, suburban gardens were integrated within the urban sprawl. The Monforte Gardens in Valencia represent a relevant case study characteristic of nineteenth century major garden design and development transformations. Most significant are the design resources and strategies introduced in the original design by Sebastián Monléon and, subsequently by Javier de Winthuysen as this research —including a thorough redrawing of the garden layout— gives evidence of. The Monforte Gardens represent an eclectic urban gardening design example in which the different parts maintain their independence without losing an overall unitary concept. Although traditionally considered neoclassical gardens, this research argues they should be properly considered as eclectic romantic gardens
Observed degradation in photovoltaic plants affected by hot-spots
A number of findings have shown that the test procedures currently available to determine the reliability and durability of photovoltaic (PV) modules are insufficient to detect certain problems. To improve these procedures, ongoing research into the actual performance of the modules in the field is required. However, scientific literature contains but few references to field studies of defective modules. This article studies two different localized heating phenomena affecting the PV modules of two large-scale PV plants in Spain. The first problem relates to weak solder joints whilst the second is due to microcracks on the module cells. For both cases, the cause is identified, and consideration is given with regard to the effect on performance, the potential deterioration over time, and a way to detect the problems identified. The findings contained in this paper will prove to be of considerable interest to maintenance personnel at large-scale PV plants and also to those responsible for setting module quality standards and specifications, and even the PV module manufacturers themselves
STC power for 15MW of PV comparing nameplate, initial power and power after 4 years
To date, the majority of quality controls performed at PV plants are based on the measurement of a small sample of individual modules. Consequently, there is very little representative data on the real Standard Test Conditions (STC) power output values for PV generators. This paper presents the power output values for more than 1300 PV generators having a total installed power capacity of almost 15.3 MW. The values were obtained by the INGEPER-UPNA group, in collaboration with the IES-UPM, through a study to monitor the power output of a number of PV plants from 2006 to 2009. This work has made it possible to determine, amongst other things, the power dispersion that can be expected amongst generators made by different manufacturers, amongst generators made by the same manufacturer but comprising modules of different nameplate ratings and also amongst generators formed by modules with the same characteristics. The work also analyses the STC power output evolution over time in the course of this 4-year study. The values presented here could be considered to be representative of generators with fault-free modules
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