797 research outputs found

    Estudio del problema de programación de la producción en un ambiente multi-propósito flexible con división de lotes

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    127 páginas. Maestría en Optimización.El problema de programación de tareas conocido como programación de la producción en un ambiente multi-propósito flexible con división de lotes es una variante del problema de tipo programación de la producción, en la cual los lotes pueden dividirse en sublotes de diferentes tamaños y asignarse a diferentes máquinas, de tal forma que se disminuyen los tiempos muertos y el tiempo total de procesamiento. El objetivo consiste en minimizar la amplitud de proceso, es decir, la fecha de terminación de la última operación en la última máquina. Debido a la complejidad computacional de este problema, normalmente se recurre a técnicas heurísticas para poder resolverlo. En este trabajo, se propone un algoritmo que combina estrategias de Búsqueda Tabú, con vecindades y técnicas de división de lotes basados en la ruta crítica de cada solución generada. Para determinar la eficiencia del algoritmo propuesto, se adaptaron las instancias edata, rdata y vdata de Hurink. Debido a que este problema casi no se ha reportado en la literatura, no fue posible encontrar soluciones, que sirvieran como punto de comparación, para las instancias antes mencionadas. Por lo tanto, se emplearon dos estrategias para poder evaluar el desempeño del algoritmo propuesto. Primero, se resolvieron las instancias propuestas hasta donde fue posible, con el solver Gurobi. Segundo, se emplearon los mejores resultados reportados, sin división de lotes, para este mismo conjunto de instancias. Los experimentos realizados muestran que el algoritmo propuesto es capaz de generar buenas soluciones en tiempos de cómputo aceptables. Por otro lado, se evidencian los beneficios de la estrategia combinando flexibilidad y división de lotes, introducida en este trabajo.The exible job shop scheduling problem with lot streaming or lot splitting is a variant of the job shop scheduling problem, in which a job can be divided into sublots of diferent sizes and assigned to diferent machines, in such a way that processing times can be reduced. In this version the objective is to minimize the makespan. Due to the computational complexity, heuristic techniques are usually used to solve this type of problem. In this thesis, we propose an algorithm that combines tabu search strategies, with specific neighborhoods and lot splitting techniques based on the critical path of each generated schedule. To determine the eficiency of the proposed algorithm, the Hurink's instances edata, rdata, vdata were adapted to the lot splitting policy. Since this problem has hardly been reported in the literature, it was not possible to find solutions to compare with, for the aforementioned instances. Therefore, two strategies were used to evaluate the performance of the proposed algorithm. First, the instances were solved as far as possible, with the Gurobi solver. Second, the best reported solutions, without lot streaming, were used as a reference for this set of instances. The experiments showed that the proposed algorithm is able to generate good solutions in an reasonable computing time. Besides, these results provide clear evidence regarding the benefits of strategy proposed in this work, combining exibilty and lot streaming.Consejo Nacional de Ciencia y Tecnología (México)

    Early postoperative complications of transvaginal access in minimally invasive sigmoid colon procedures

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    Objectives: The aim of the study was to evaluate early (the first 30 days) postoperative complications after transvaginal resection of the sigmoid colon. Material and Methods: A total of 23 laparoscopy-assisted transvaginal resections of the sigmoid colon and 1 NOTES transvaginal sigmoid resection were performed in the course of 3 years. Postoperative complications were recorded in a prospective manner. Results: In the group of 24 patients operated on using the transvaginal approach, 6 (25%) complications were recorded, including 3 urinary tract infections, 2 vaginal bleedings, and 1 abdominal trocar site hernia. Conclusion: Early postoperative complication rate after transvaginal resection of the sigmoid colon is relatively low and the clinical complications are not severe

    Asynchronous processing for latent fingerprint identification on heterogeneous CPU-GPU systems

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    Latent fingerprint identification is one of the most essential identification procedures in criminal investigations. Addressing this task is challenging as (i) it requires analyzing massive databases in reasonable periods and (ii) it is commonly solved by combining different methods with very complex data-dependencies, which make fully exploiting heterogeneous CPU-GPU systems very complex. Most efforts in this context focus on improving the accuracy of the approaches and neglect reducing the processing time. Indeed, the most accurate approach was designed for one single thread. This work introduces the fastest methodology for latent fingerprint identification maintaining high accuracy called Asynchronous processing for Latent Fingerprint Identification (ALFI). ALFI fully exploits all the resources of CPU-GPU systems using asynchronous processing and fine-coarse parallelism for analyzing massive databases. Our approach reduces idle times in processing and exploits the inherent parallelism of comparing latent fingerprints to fingerprint impressions. We analyzed the performance of ALFI on Linux and Windows operating systems using the well-known NIST/FVC databases. Experimental results reveal that ALFI is in average 22x faster than the state-of-the-art algorithm, reaching a value of 44.7x for the best-studied case

    EEG abnormalities and clinical phenotypes in pre-school children with autism spectrum disorder

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    Abnormalities on electroencephalography (EEG) results have been reported in a high percentage of children with Autism Spectrum Disorder (ASD). The purpose of this study was to explore the prevalence of EEG abnormalities in a clinical population of pre-school children with Autism Spectrum Disorder and the differences in terms of the following phenotypic characteristics: adaptive behavior, executive functioning, severity of Autism Spectrum Disorder core symptoms, and comorbidity symptoms.The first author have been supported by Alicia Koplowitz Foundation and University of Málaga to carry on the present study. Funding for open access charge: Universidad de Málaga / CBU

    Emotional Processing Profile in Patients with First Episode Schizophrenia:The Influence of Neurocognition

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    This study sought to investigate the influence of neurocognition on the emotional processing profiles of patients with first-episode schizophrenia, using the 4-branch Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) (Perceiving Emotions; Facilitating Emotions; Understanding Emotions and Managing Emotions). A sample of 78 patients with first-episode schizophrenia and a group of 90 non-psychiatric control subjects were included in this work. The initial results showed that patients had lower scores than controls for the "Understanding Emotions" and "Managing Emotions" MSCEIT branches. However, after controlling for neurocognition, the only deficits were found on the "Managing Emotions" branch of the MSCEIT. This branch can be considered as measuring a more sophisticated level of emotional processing, which may constitute a deficit in itself. In conclusion, patients with first-episode schizophrenia present deficits in social cognition at the highest level that seem to be independent from neurocognition. These findings support the inclusion of the "Managing Emotions" branch of the MSCEIT as part of the MCCB.Instituto de Salud Carlos III (PI16/00359)Instituto de Salud Carlos III (PI19/00766)Comunidad de Madrid (S2017/BMD-3740)Ministry of Health (MOH-000013)4.242 JCR (2020) Q1, 39/167 Medicine, general & internal1.040 SJR (2021) Q1, 438/2489 Medicine (miscellaneous)No data IDR 2020UE

    Burden and challenges of heart failure in patients with chronic kidney disease. A call to action

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    Patients with the dual burden of chronic kidney disease (CKD) and chronic congestive heart failure (HF) experience unacceptably high rates of symptom load, hospitalization, and mortality. Currently, concerted efforts to identify, prevent and treat HF in CKD patients are lacking at the institutional level, with emphasis still being placed on individual specialty views on this topic. The authors of this review paper endorse the need for a dedicated cardiorenal interdisciplinary team that includes nephrologists and renal nurses and jointly manages appropriate clinical interventions across the inpatient and outpatient settings. There is a critical need for guidelines and best clinical practice models from major cardiology and nephrology professional societies, as well as for research funding in both specialties to focus on the needs of future therapies for HF in CKD patients. The implementation of crossspecialty educational programs across all levels in cardiology and nephrology will help train future specialists and nurses who have the ability to diagnose, treat, and prevent HF in CKD patients in a precise, clinically effective, and cost-favorable manner.Los pacientes con enfermedad renal crónica (ERC) que desarrollan insuficiencia cardíaca (IC) congestiva crónica presentan cifras inaceptablemente altas de síntomas, hospitalización y mortalidad. Actualmente, se echan en falta iniciativas institucionales dirigidas a identificar, prevenir y tratar la IC en los pacientes con ERC de manera multidisciplinar, prevaleciendo las actuaciones de las especialidades individuales. Los autores de este artículo de revisión respaldan la necesidad de crear equipos multidisciplinares cardiorrenales, en los que participen nefrólogos y enfermeras renales, que gestionen colaborativamente las intervenciones clínicas apropiadas en los entornos de pacientes con ERC e IC hospitalizados y ambulatorios. Es necesario y urgente que se elaboren guías y modelos de práctica clínica sobre la ERC con IC por parte de las sociedades profesionales de cardiología y nefrología, así como financiación para la investigación concertada entre ambas especialidades sobre la necesidad de futuros tratamientos para la IC en pacientes con ERC. La implementación de programas educativos cardiorrenales a todos los niveles en cardiología y nefrología ayudará a formar a los futuros especialistas y enfermeras para que tengan la capacidad de diagnosticar, tratar y prevenir la IC en pacientes con ERC de manera precisa, clínicamente efectiva y económicamente favorabl

    Impact of the first wave of the SARS-CoV-2 pandemic on the outcome of neurosurgical patients: A nationwide study in Spain

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    Objective To assess the effect of the first wave of the SARS-CoV-2 pandemic on the outcome of neurosurgical patients in Spain. Settings The initial flood of COVID-19 patients overwhelmed an unprepared healthcare system. Different measures were taken to deal with this overburden. The effect of these measures on neurosurgical patients, as well as the effect of COVID-19 itself, has not been thoroughly studied. Participants This was a multicentre, nationwide, observational retrospective study of patients who underwent any neurosurgical operation from March to July 2020. Interventions An exploratory factorial analysis was performed to select the most relevant variables of the sample. Primary and secondary outcome measures Univariate and multivariate analyses were performed to identify independent predictors of mortality and postoperative SARS-CoV-2 infection. Results Sixteen hospitals registered 1677 operated patients. The overall mortality was 6.4%, and 2.9% (44 patients) suffered a perioperative SARS-CoV-2 infection. Of those infections, 24 were diagnosed postoperatively. Age (OR 1.05), perioperative SARS-CoV-2 infection (OR 4.7), community COVID-19 incidence (cases/10 5 people/week) (OR 1.006), postoperative neurological worsening (OR 5.9), postoperative need for airway support (OR 5.38), ASA grade =3 (OR 2.5) and preoperative GCS 3-8 (OR 2.82) were independently associated with mortality. For SARS-CoV-2 postoperative infection, screening swab test <72 hours preoperatively (OR 0.76), community COVID-19 incidence (cases/10 5 people/week) (OR 1.011), preoperative cognitive impairment (OR 2.784), postoperative sepsis (OR 3.807) and an absence of postoperative complications (OR 0.188) were independently associated. Conclusions Perioperative SARS-CoV-2 infection in neurosurgical patients was associated with an increase in mortality by almost fivefold. Community COVID-19 incidence (cases/10 5 people/week) was a statistically independent predictor of mortality. Trial registration number CEIM 20/217

    Height and timing of growth spurt during puberty in young people living with vertically acquired HIV in Europe and Thailand.

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    OBJECTIVE: The aim of this study was to describe growth during puberty in young people with vertically acquired HIV. DESIGN: Pooled data from 12 paediatric HIV cohorts in Europe and Thailand. METHODS: One thousand and ninety-four children initiating a nonnucleoside reverse transcriptase inhibitor or boosted protease inhibitor based regimen aged 1-10 years were included. Super Imposition by Translation And Rotation (SITAR) models described growth from age 8 years using three parameters (average height, timing and shape of the growth spurt), dependent on age and height-for-age z-score (HAZ) (WHO references) at antiretroviral therapy (ART) initiation. Multivariate regression explored characteristics associated with these three parameters. RESULTS: At ART initiation, median age and HAZ was 6.4 [interquartile range (IQR): 2.8, 9.0] years and -1.2 (IQR: -2.3 to -0.2), respectively. Median follow-up was 9.1 (IQR: 6.9, 11.4) years. In girls, older age and lower HAZ at ART initiation were independently associated with a growth spurt which occurred 0.41 (95% confidence interval 0.20-0.62) years later in children starting ART age 6 to 10 years compared with 1 to 2 years and 1.50 (1.21-1.78) years later in those starting with HAZ less than -3 compared with HAZ at least -1. Later growth spurts in girls resulted in continued height growth into later adolescence. In boys starting ART with HAZ less than -1, growth spurts were later in children starting ART in the oldest age group, but for HAZ at least -1, there was no association with age. Girls and boys who initiated ART with HAZ at least -1 maintained a similar height to the WHO reference mean. CONCLUSION: Stunting at ART initiation was associated with later growth spurts in girls. Children with HAZ at least -1 at ART initiation grew in height at the level expected in HIV negative children of a comparable age

    Ciencias Sociales: Economía y Humanidades

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    Este volumen I contiene 29 capítulos arbitrados que se ocupan de estos asuntos en Tópicos Selectos de Ciencias Sociales: Economía y Humanidades, elegidos de entre las contribuciones, reunimos algunos investigadores y estudiantes.Gómez, presenta un breve examen de la producción y comercialización de rosa en México; Arpi y Portillo realiza un estudio en México sobre el ingreso mínimo de las familias que identifica la línea de pobreza alimentaria en el área rural del sur de México, 2012; Bravo realiza un pequeño estudio donde hablará sobre el análisis comparado del Sector Gubernamental y la Economía Mexicana desde la perspectiva de los eslabonamientos productivos Hirshman-Rasmuss; Caamal, Pat, Jerónimo y Romero realizan un estudio sobre los canales de comercialización de limón persa en el municipio de Martínez de la Torre, Veracruz; Macías y Perales nos hablarán sobre una análisis del comercio estratégico en el TLCAN: El Estado en la política agrícola de biocombustibles; Figueroa, Pérez y Godínez se expresan acerca de la importancia de la comercialización del café en México; Sepúlveda, Sepúlveda y Pérez realizan un diagnóstico, retos del comercio electrónico en el Sector Agroindustrial Mexicano; Duana mediante su trabajo nos muestra y habla sobre la inversión extranjera directa y su impacto en crecimiento de México, un análisis en prospectiva: 1999-2010; Figueroa, Pérez y Ramírez hacen un estudio acerca sobre la importancia de la Banca en México; Pérez, Figueroa, Godínez y Pérez presenta un trabajo acerca de la competitividad de la producción agrícola en México, un análisis regional; Rodríguez, Espinosa y Márquez analizan todo acerca de el SIAL productor de quesos en Poxtla, competividad y territorio; Garza nos habla acerca de la intermediación financiera al servicio de la comunidad indígena: el fondo regional indígena Tarhiata Keri; Arroyo, Aguilar, Santoyo y Muñoz realizan un estudio acerca de la demanda de Importaciones de durazno (Prunus pérsica L. Batsch) en México procedentes de Estados Unidos de América (1982-2011); Loera y Sepúlveda analizan los parámetros de la productividad forestal en la producción de madera en rollo; Pérez, Morett y Tecpan realizan un análisis de factores sociales, ambientales y económicos del territorio rural cercano a la ciudad de México; Godínez, Figueroa y Pérez realizan un estudio acerca de la crisis económica mundial y su efecto sobre los flujos migratorios de América Latina; Magadán, Hernández y Escalona presentan la tipología de los sujetos sociales que intervienen en el mercado campesino de Ocotlán Oaxaca; Tavera y Cobos nos hablan de la normalización del proceso de compostaje: una opción para desarrollar el mercado de la composta; Piña y Pérez hablan acerca de la reestructuración del capitalismo y crisis política en México; Gonzáles, Rucoba y Ramírez realizan un estudio de la rentabilidad de la producción de miel en el municipio de León, Guanjuato; Ramírez, Gutiérrez y Figueroa realizan un estudio acerca de la economía del maíz en la región metropolitana, Chiapas, 2014; Bueno, Méndez y Cruz realizan un estudio y análisis de los centros de educación y cultura ambiental, necesidad de profesionalización Pedagógica de facilitadores ambientales; Pat, Caamal, Jerónimo y Mendoza presentan un estudio acerca de los Costos y competitividad de la producción del limón persa en el municipio de Martínez de la Torre, Veracruz. Vizuet presenta un trabajo de la construcción polisémica e histórica del concepto de la pobreza; Navarrete, Ríos y Arévalo presentan un estudio acerca de la producción ejidal de tomate rojo (Lycopersicum esculentum) en el DR-017, y su huella hídrica; Pérez y Piña hablan acerca de la productividad e inversión extranjera: La industria de Alimentos; Pérez, Figueroa, Godínez y Gómez presentan el trabajo sobre el sector primario en México; Pérez, Figueroa, Godínez y Gómez presentan acerca de los subsidios al campo como instrumento de política económica en México; Venegas, Perales y Del Valle realizan un estudio de rentabilidad de biodigestores y motogeneradores para diferentes tamaños de granjas porcinas en Michoacán

    A pan-European epidemiological study reveals honey bee colony survival depends on beekeeper education and disease control

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    Reports of honey bee population decline has spurred many national efforts to understand the extent of the problem and to identify causative or associated factors. However, our collective understanding of the factors has been hampered by a lack of joined up trans-national effort. Moreover, the impacts of beekeeper knowledge and beekeeping management practices have often been overlooked, despite honey bees being a managed pollinator. Here, we established a standardised active monitoring network for 5 798 apiaries over two consecutive years to quantify honey bee colony mortality across 17 European countries. Our data demonstrate that overwinter losses ranged between 2% and 32%, and that high summer losses were likely to follow high winter losses. Multivariate Poisson regression models revealed that hobbyist beekeepers with small apiaries and little experience in beekeeping had double the winter mortality rate when compared to professional beekeepers. Furthermore, honey bees kept by professional beekeepers never showed signs of disease, unlike apiaries from hobbyist beekeepers that had symptoms of bacterial infection and heavy Varroa infestation. Our data highlight beekeeper background and apicultural practices as major drivers of honey bee colony losses. The benefits of conducting trans-national monitoring schemes and improving beekeeper training are discussed
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