1,807 research outputs found

    On subadditive duality for conic mixed-integer programs

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    In this paper, we show that the subadditive dual of a feasible conic mixed-integer program (MIP) is a strong dual whenever it is feasible. Moreover, we show that this dual feasibility condition is equivalent to feasibility of the conic dual of the continuous relaxation of the conic MIP. In addition, we prove that all known conditions and other 'natural' conditions for strong duality, such as strict mixed-integer feasibility, boundedness of the feasible set or essentially strict feasibility imply that the subadditive dual is feasible. As an intermediate result, we extend the so-called 'finiteness property' from full-dimensional convex sets to intersections of full-dimensional convex sets and Dirichlet convex sets

    On subadditive duality for conic mixed-integer programs

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    In this paper, we show that the subadditive dual of a feasible conic mixed-integer program (MIP) is a strong dual whenever it is feasible. Moreover, we show that this dual feasibility condition is equivalent to feasibility of the conic dual of the continuous relaxation of the conic MIP. In addition, we prove that all known conditions and other 'natural' conditions for strong duality, such as strict mixed-integer feasibility, boundedness of the feasible set or essentially strict feasibility imply that the subadditive dual is feasible. As an intermediate result, we extend the so-called 'finiteness property' from full-dimensional convex sets to intersections of full-dimensional convex sets and Dirichlet convex sets

    On Subadditive Duality for Conic Mixed-Integer Programs

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    In this paper, we show that the subadditive dual of a feasible conic mixed-integer program (MIP) is a strong dual whenever it is feasible. Moreover, we show that this dual feasibility condition is equivalent to feasibility of the conic dual of the continuous relaxation of the conic MIP. In addition, we prove that all known conditions and other 'natural' conditions for strong duality, such as strict mixed-integer feasibility, boundedness of the feasible set or essentially strict feasibility imply that the subadditive dual is feasible. As an intermediate result, we extend the so-called 'finiteness property' from full-dimensional convex sets to intersections of full-dimensional convex sets and Dirichlet convex sets

    Methods for nurses to measure body composition

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    Among the methods available for assessing body composition, traditional methods like hydrodensitometry and skin-fold measurements are well known. In this review, we focus on the impedance and interactance methods, which use systems that are usually inexpensive, easily transportable and simple to operate. We also discuss the usefulness of dual energy X-ray absorptiometry, particularly for the measurement of fat distribution. Nurses need to be skilled in the use of the equipment and familiar with the techniques.Entre los métodos disponibles para la determinación de la composición corporal, los tradicionales como la hidrodensitometría y la valoración de pliegues corporales son bien conocidos. En esta revisión nos centramos en los métodos basados en la impedancia y en la interactancia, caracterizados por la utilización de equipos económicos, fáciles de transportar y manejar. También discutimos la utilidad de la absorciometría dual de rayos-X, particularmente para la determinación de la distribución de la grasa corporal. Es importante que el personal de enfermería adquiera competencias en el uso de estos equipamientos y también se familiarice con las técnicas descritas.Entre os métodos disponíveis para a determinação da composição corporal, os tradicionais, como a hidrodensitometria e a avaliação de pregas corporais, são bem conhecidos. Para esta revisão, centrou-se nos métodos baseados na impedância e a interactância, caracterizados pela utilização de equipamentos econômicos, fáceis de transportar e manobrar. Também discutiu-se a utilidade da absorciometria dual de raios X, especialmente para a determinação da distribuição da gordura corporal. É importante que o pessoal de enfermagem adquira conhecimentos sobre o uso desse equipamento, bem como que se familiarize com as técnicas descritas

    Bacterial fecal microbiota is only minimally affected by a standardized weight loss plan in obese cats

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    Background: Research in humans and mice suggests that obesity influences the abundance and diversity of gastrointestinal (GI) microbiota, and that an "obese microbiome" influences energy metabolism and fat storage in the host. Microbiota membership and composition have been previously assessed in healthy cats. However, research investigating the effects of obesity and weight loss on the cat's fecal microbiota is limited. Therefore, this study's objective was to evaluate differences in fecal microbial abundance and biodiversity, as well as serum cobalamin and folate concentrations in obese cats, before and after weight loss, and compare to lean cats. Fourteen lean and 17 obese healthy client-owned cats were fed a veterinary therapeutic weight loss food at maintenance energy requirement for 4 weeks. At the end of week 4, lean cats finished the study, whereas obese cats continued with a 10-week weight loss period on the same food, fed at individually-tailored weight loss energy requirements. Body weight and body condition score were recorded every 2 weeks throughout the study. At the end of each period, a fecal sample and food-consumption records were obtained from the owners, and serum cobalamin and folate concentrations were analysed. DNA was extracted from fecal samples, polymerase chain reaction (PCR) was performed, and products were sequenced using next-generation sequencing (Illumina MiSeq). Results: No significant differences in the relative abundance of taxa and in biodiversity indices were observed between cats in either group (P > 0.05 for all tests). Nevertheless, some significantly enriched taxa, mainly belonging to Firmicutes, were noted in linear discriminant analysis effect size test in obese cats before weight loss compared to lean cats. Serum cobalamin concentrations were significantly higher in lean compared to obese cats both before and after weight loss. Serum folate concentrations were higher in obese cats before weight loss compared to after. Conclusions: The association between feline obesity and the fecal bacterial microbiota was demonstrated in enriched taxa in obese cats compared to lean cats, which may be related to enhanced efficiency of energy-harvesting. However, in obese cats, the fecal microbial abundance and biodiversity were only minimally affected during the early phase of a standardized weight loss plan

    The Collimated Jet Source in IRAS 16547-4247: Time Variation, Possible Precession, and Upper Limits to the Proper Motions Along the Jet Axis

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    The triple radio source detected in association with the luminous infrared source IRAS 16547-4247 has previously been studied with high angular resolution and high sensitivity with the Very Large Array (VLA) at 3.6-cm wavelength. In this paper, we present new 3.6 cm observations taken 2.68 years after the first epoch that allow a search for variability and proper motions, as well as the detection of additional faint sources in the region. We do not detect proper motions along the axis of the outflow in the outer lobes of this source at a 4-σ\sigma upper limit of \sim160 km s1^{-1}. This suggests that these lobes are probably working surfaces where the jet is interacting with a denser medium. However, the brightest components of the lobes show evidence of precession, at a rate of 0.080\rlap.^\circ08 yr1^{-1} clockwise in the plane of the sky. It may be possible to understand the distribution of almost all the identified sources as the result of ejecta from a precessing jet. The core of the thermal jet shows significant variations in flux density and morphology. We compare this source with other jets in low and high mass young stars and suggest that the former can be understood as a scaled-up version of the latter.Comment: 26 pages, 9 figure

    Propuesta de un plan de mejora para incrementar la productividad de los procesos de secado y pilado de arroz en cáscara en una empresa agroindustrial

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    El presente trabajo de investigación consta en la aplicación de la metodología DMAIC y sus herramientas de medición, mejora, planificación y control en los procesos de secado de arroz y pilado de arroz para consumo humano en la empresa Molino Imperio S.A.C, la cual es una empresa molinera y de siembra de arroz de la ciudad de Pucallpa del departamento de Ucayali. Se evaluaron los factores que afectan la eficiencia de máquinas, personal y se logró reconocer el impacto que estas ocasionan a la productividad de la empresa. Entre los factores detectados tenemos el mal control de los niveles de temperatura, humedad y tiempo, que afectan en las áreas de secado y pilado correspondientemente lo cual ocasiona un incremento en los subproductos de arroz pilado que causa que la productividad de arroz entero disminuya afectando la productividad de la empresa. Dentro del plan de mejora, se realizaron planes de capacitaciones y planes de mantenimiento en las máquinas, para así aumentar la eficiencia en los procesos de pilado y secado, con la finalidad de aumentar nuestra productividad. Se aplicó el plan de capacitaciones para que los operarios adquieran los conocimientos, herramientas, habilidades, actitudes para interactuar de forma eficiente y cumplir con el objetivo principal el cual es el incremento de productividad. Se aplicó el plan de mantenimiento preventivo para reducir las averías y disminuyan la probabilidad que la maquina falle y tener posibles paradas. Con este plan de mejora, se logró mejorar los indicadores en los procesos de secado y pilado de arroz, haciendo que le indicador de humedad y temperatura tenga una mejora de 2.93% y un incremento en la productividad de los procesos de 35.55% tras su implementación. Para la comprobación de los resultados se utilizó la simulación a través del software Promodel

    Inteligencia emocional y desempeño laboral en los trabajadores de la Sub Región de Salud de Sullana - 2019

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    Esta investigación tiene como objetivo determinar la relación entre la Inteligencia Emocional y el Desempeño Laboral de los trabajadores de la Sub Región de Salud de Sullana. Asimismo presenta un tipo de estudio aplicado, ya que está orientada a la resolución de problemas, el nivel de la investigación es correlacional ya que determina la relación entre ambas variables de estudios a través de un diseño no experimental. Asimismo las técnicas de recolección de datos que se emplearon fueron la encuesta dirigida a trabajadores de la Sub Región de Salud de Sullana y una entrevista al director de recursos humanos de esta entidad, cuya población estuvo integrada por 180 trabajadores y como muestra se optó escoger a toda la población dado el pequeño tamaño de la población. Finalmente, se concluyó que si existe una relación entre la Inteligencia Emocional y el Desempeño Laboral en los trabajadores de la Sub Región de Salud de Sullana, dado que el nivel de significancia es p<.05 y el coeficiente de correlación de Rho de Spearman representa ,396 lo que significa una correlación significativa, por lo tanto a medida que se logre fortalecer la inteligencia emocional de los trabajadores el desempeño laboral de estos mejorará rotundamente

    Mining drives extensive deforestation in the Brazilian Amazon

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    Mining poses significant and potentially underestimated risks to tropical forests worldwide. In Brazil\u27s Amazon, mining drives deforestation far beyond operational lease boundaries, yet the full extent of these impacts is unknown and thus neglected in environmental licensing. Here we quantify mining-induced deforestation and investigate the aspects of mining operations, which most likely contribute. We find mining significantly increased Amazon forest loss up to 70 km beyond mining lease boundaries, causing 11,670 km2 of deforestation between 2005 and 2015. This extent represents 9% of all Amazon forest loss during this time and 12 times more deforestation than occurred within mining leases alone. Pathways leading to such impacts include mining infrastructure establishment, urban expansion to support a growing workforce, and development of mineral commodity supply chains. Mining-induced deforestation is not unique to Brazil; to mitigate adverse impacts of mining and conserve tropical forests globally, environmental assessments and licensing must considered both on- and off-lease sources of deforestation
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