468 research outputs found

    A parallel computation approach for solving multistage stochastic network problems

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    The original publication is available at www.springerlink.comThis paper presents a parallel computation approach for the efficient solution of very large multistage linear and nonlinear network problems with random parameters. These problems result from particular instances of models for the robust optimization of network problems with uncertainty in the values of the right-hand side and the objective function coefficients. The methodology considered here models the uncertainty using scenarios to characterize the random parameters. A scenario tree is generated and, through the use of full-recourse techniques, an implementable solution is obtained for each group of scenarios at each stage along the planning horizon. As a consequence of the size of the resulting problems, and the special structure of their constraints, these models are particularly well-suited for the application of decomposition techniques, and the solution of the corresponding subproblems in a parallel computation environment. An augmented Lagrangian decomposition algorithm has been implemented on a distributed computation environment, and a static load balancing approach has been chosen for the parallelization scheme, given the subproblem structure of the model. Large problems – 9000 scenarios and 14 stages with a deterministic equivalent nonlinear model having 166000 constraints and 230000 variables – are solved in 45 minutes on a cluster of four small (11 Mflops) workstations. An extensive set of computational experiments is reported; the numerical results and running times obtained for our test set, composed of large-scale real-life problems, confirm the efficiency of this procedure.Publicad

    A parallel computation approach for solving multistage stochastic network problems

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    This paper presents a parallel computation approach for the efficient solution of very large multistage linear and nonIinear network problems with random parameters. These problems resul t from particular instances of models for the robust optimization of network problems with uncertainty in the values of the right-hand side and the objective function coefficients. The methodology considered here models the uncertainty using scenarios to characterize the random parameters. A. scenario tree is generated and, through the use of full-recourse techniques, an implementable solution is obtained for each group of scenarios at each stage along the planning horizon. As a consequence of the size of the resulting problems, and the special structure of their constraints, these models are particularly well-suited for the application of decomposition techniques, and the solution of the corresponding subproblems in a parallel computation environment. An Augmented Lagrangian decomposition algorithm has been implemented on a distributed computation environment, and a static load balancing approach has been chosen for the parallelization scheme. given the subproblem structure of the model. Large problems -9000 scenarios and 14 stages with a deterministic equivalent nonlinear model having 166000 constraints and 230000 variables- are solved in 15 minutes on a cluster of 4 small (16 Mflops) workstations. An extensive set of computational experiments is reported; the numerical results and running times obtained for our test set, composed of large-scale real-life problems, confirm the efficiency of this procedure

    Performance outcome measures in padel: a scoping review

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    Padel is a modern doubles racket sport which has become popular around the world in the last decades. There has been an increase in the quantity of scientific research about this sport in the last years. Therefore, the main objective of this scoping review is to provide an updated contextualization of research regarding padel. PRISMA ScR was used in order to search for articles fulfilling the inclusion criteria in five fields of interest: the anthropometric profile, physiology and physical performance, biomechanics, the epidemiology of injuries, and match analyses Seventy-seven records were included in the study. Padel is an emerging sport both in sport and research terms. This scoping review provides coaches and researchers with all the knowledge available in the five fields of interest. Furthermore, this study enables them to make a map of the current state of the research about padel, and it opens up doors to future investigations. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

    Magnetic separation and high reusability of chloroperoxidase entrapped in multi polysaccharide micro-supports

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    Enzyme immobilization on magnetic supports represents a great advantage for the industrial application of enzymatic catalysis since it allows an easy recovery of the catalyst, avoiding any contamination of the product by residual enzyme. Iron oxide nanoparticles are very useful for this purpose. Using a polymer to diminish the interaction between the magnetic cores themselves, can improve the colloidal stability of the support and prevent any interaction with the environment that would affect both support properties and enzyme stability. For this reason, in this work different magnetic micro-supports, based on polydopamine-coated iron oxide nanoparticles with a multi polysaccharide shell, have been developed. These supports have been used to immobilize chloroperoxidase, a very interesting enzyme, able to catalyze many reactions of large-scale interest, but whose application is limited by its sensitivity to reaction conditions. The multi polysaccharide shells of the supports were obtained through a combination of chitosan and alginate. An in-depth analysis of physicochemical and catalytic properties of all the developed magnetic supports is reported. CPO was successfully immobilized with an efficiency of entrapment between 92% and 100% in the case of supports with chitosan in the interior or outer shell respectively. A very good chemical stability of the support under reaction conditions was observed in the case of an interior shell of alginate and an outer coating of chitosan, together with an excellent reusability of the immobilized enzyme, that was recycled to catalyze up to 25 consecutive reaction cycles

    Prevalence, Related Factors, and Levels of Burnout Syndrome Among Nurses Working in Gynecology and Obstetrics Services: A Systematic Review and Meta-Analysis

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    Background: Although burnout levels and the corresponding risk factors have been studied in many nursing services, to date no meta-analytical studies have been undertaken of obstetrics and gynecology units to examine the heterogeneity of burnout in this environment and the variables associated with it. In the present paper, we aim to determine the prevalence, levels, and related factors of burnout syndrome among nurses working in gynecology and obstetrics services. Methods: A systematic review and meta-analysis of the literature were carried out using the following sources: CINAHL (Cumulative Index of Nursing and Allied Health Literature), LILACS (Latin American and Caribbean Health Sciences Literature), Medline, ProQuest (Proquest Health and Medical Complete), SciELO (Scientific Electronic Library Online), and Scopus. Results: Fourteen relevant studies were identified, including, for this meta-analysis, n = 464 nurses. The following prevalence values were obtained: emotional exhaustion 29% (95% CI: 11–52%), depersonalization 19% (95% CI: 6–38%), and low personal accomplishment 44% (95% CI: 18–71%). The burnout variables considered were sociodemographic (age, marital status, number of children, gender), work-related (duration of the workday, nurse-patient ratio, experience or number of miscarriages/abortions), and psychological (anxiety, stress, and verbal violence). Conclusion: Nurses working in obstetrics and gynecology units present high levels of burnout syndrome. In over 33% of the study sample, at least two of the burnout dimensions considered are apparent.This research was funded by the Excellence Research Project (P11HUM-7771) provided by the Andalusian Government (Spain)

    High-level quinolone resistance is associated with the overexpression of smeVWX in Stenotrophomonas maltophilia clinical isolates

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    AbstractStenotrophomonas maltophilia is the only known bacterium in which quinolone-resistant isolates do not present mutations in the genes encoding bacterial topoisomerases. The expression of the intrinsic quinolone resistance elements smeDEF, smeVWX and Smqnr was analysed in 31 clinical S. maltophilia isolates presenting a minimum inhibitory concentration (MIC) range to ciprofloxacin between 0.5 and > 32 μg/mL; 11 (35.5%) overexpressed smeDEF, 2 (6.5%) presenting the highest quinolone MICs overexpressed smeVWX and 1 (3.2%) overexpressed Smqnr. Both strains overexpressing smeVWX presented changes at the Gly266 position of SmeRv, the repressor of smeVWX. Changes at the same position were previously observed in in vitro selected S. maltophilia quinolone-resistant mutants, indicating this amino acid is highly relevant for the activity of SmeRv in repressing smeVWX expression. For the first time SmeVWX overexpression is associated with quinolone resistance of S. maltophilia clinical isolates

    El trastorno autista: un análisis de los aspectos asociados (I)

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    [Resumen] A través de esta comunicación pretendemos resumir de la manera más clara posible nuestro propio estudio del trastorno autista enmarcado dentro de los trastornos generalizados del desarrollo. Esto, a su vez, nos servirá de introducción para una investigación que sobre diferentes patologías y trastornos del lenguaje estamos llevando a cabo. Además, queremos transmitir una serie de aspectos asociados al autismo reflejados en 37 sujetos que asisten a centros específicos de ASPANAES (Asociación de Pais de Persoas Autistas e Psicóticas da Provincia da Coruña) de Castelo Culleredo, Ferrol, Santiago, y As Pontes. Describimos aspectos tales como, prevalencia, sexo, patrón falniliar, clase social, funcionamiento intelectual, epilepsia y sistema sensorioperceptiv

    Compassion Fatigue, Compassion Satisfaction, and Burnout in Oncology Nurses: A Systematic Review and Meta-Analysis

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    Professionals working in cancer care are exposed to strong sources of stress. Due to the special characteristics of this unit, the appearance of burnout, compassion fatigue, and low compassion satisfaction is more likely. The principal aim was to analyze the levels and prevalence of burnout, compassion fatigue, and low compassion satisfaction in oncology nurses and interventions for its treatment. The search for the systematic review was done in Medline, ProQuest, Lilacs, CINAHL, Scopus, Scielo, and PsycINFO databases, with the search equation “burnout AND nurs* AND oncology AND compassion fatigue”. The results obtained from the 15 studies confirmed that there are levels of risk of suffering burnout and compassion fatigue among nursing professionals, affecting more women and nurses with more years of experience, with nurses from oncology units having one of the highest levels of burnout and compassion fatigue. The oncology nurse sample was n = 900. The meta-analytic estimations were 19% for low compassion satisfaction, 56% for medium and high burnout, BO, and 60% for medium and high compassion fatigue. The increase in cases of burnout and compassion fatigue in nursing staff can be prevented and minimized with a correct evaluation and development of intervention programs, considering that there are more women than men and that they seem to be more vulnerable

    Patología del lenguaje (II)

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    [Resumen] La presente comunicación trata de relacionar las dificultades del lenguaje con los Trastornos Generalizados de la Personalidad (TGP), especialmente con el autismo. Consta de un marco legal que refleja la evolución histórica de los trastornos del lenguaje a partir de la década de los 70; de la patología del lenguaje del niño autista en sus subapartados: habilidades prelingüísticas, ecolalia, inversión pronominal, semántica, lenguaje y memoria, pragmática, fonética, sintaxis, prosodia, comunicación no verbal y trastonos varios. Partimos de una muestra de 70 sujetos autistas de 4 centros de atención específica, ASPANAES, de la provincia de La Coruña, en edades comprendidas entre 2 y 26 años. Nuestro objetivo es determinar la frecuencia y como se distribuyen los trastornos del lenguaje en esta patología

    Emergency and critical care professionals' opinion on escape room as a health sciences evaluation game: A cross-sectional descriptive study

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    New teaching and evaluation methods are growing in health sciences. The escape room is a game that is showing benefits for assessing knowledge and important competencies in healthcare professionals. The aim of this study is to analyse the opinion of emergency and critical care professionals on the use of escape rooms as an evaluation game.A quantitative, descriptive, cross-sectional study was conducted using an ad-hoc questionnaire with a Likert-type scale. The study included emergency and critical care professionals who participated in the escape room "The Frustrated Emergency and Critical Care Professional," that took place during an emergency and critical care national congress. Data collection was carried out in June 2019.The sample was composed of n = 50 emergency and critical care professionals, 52% of whom were physicians and 48% were nurses. Professionals believe that this is a good teaching game for evaluation and useful for strengthen knowledge (4.7 points), as well as to improve teamwork and the ability to work under pressure (4.9).The escape room is a useful evaluation game in the context of emergency and critical care units that also allows training the teamwork and working under pressure competencies.The authors want to thank SEMES for the opportunity of developing and executing the escape room during their congress
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