290 research outputs found

    Choice-Nash Equilibria

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    We provide existence results for equilibria of games where players employ abstract (non binary) choice rules. Such results are shown to encompass as a relevant instance that of games where players have (non-transitive) SSB (Skew-Symmetric Bilinear) preferences, as will as other well-known transitive (e. g. Nash´s) and non-transitive (e. g. Shafer and Sonnenschein´s) models in the literature. Further, our general model contains games where players display procedural rationality.

    Testing minimum cost strategies of pumping systems with scheduled electric tariffs in a lab scale plant

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    Ponencia presentada en IFAC Papers Online : Conference Paper ArchiveThis paper describes the development and testing of a lab plant that emulates a water supply pumping system with the objective of testing optimal pumping strategies based on standard solvers. The emulated system consists of two tanks that supply the water to two districts in a town. There are two pumps, that can fill the tanks through a reconfigurable hydraulic system with several valves. The automatic controller determines the valves and pumps that are active at each instant of time in order to minimize the operation cost, taking into account the electric tariff periods. Some aspects on the development of the lab plant are first discussed, including hydraulic aspects and real time control implementation issues. Then, a mathematical model is proposed to be able to formulate, in matrix form, the cost index and the constraints, such that, standard solvers as Mosek or CBC can be used. The full optimization proposal is tested on several experiments, and compare to some simulations, to demostrate the validity of the plant and the optimization approac

    El trastorno por estrés postraumático en los supervivientes al cáncer: una revisión de los tratamientos psicológicos disponibles

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    Objective: Posttraumatic stress disorder (PTSD) appears frequently in cancer survivors, but not all survivors meet the criteria propo­sed by the DSM-V to be diagnosed with PTSD. This situation may lead an underestimation of the problem and furthermore, in this patient group, PTSD is related with different aspects of psychological well-being, such as depres­sion, anxiety or quality of life, However, the­re are only a few psychological interventions designed to reduce these symptoms in cancer survivors. Method: A review of the psychological treatments available for PTSD in cancer sur­vivors in the last 10 years was performed. The data bases used were PubMed, Web of Science (WOS) and PsycInfo with the following des­criptors: PTSD (posttraumatic stress disorder) treatment cancer survivors y PTSS (posttrau­matic stress symptoms) treatment cancer sur­vivors. Results: The psychological interventions with more evidence are: cognitive-behavioral therapy and mindfulness, ahead other strate­gies such as stress management training, neu­ro-emotional therapy, coping skills training and counseling. Conclusions: Despite the relevance of PTSD in this patients group, psychological interventions needs more evidence to establish their efficacy to reduce these symptoms in survivors.Objetivo: El trastorno por estrés postrau­mático (TEP) aparece con frecuencia en los su­pervivientes al cáncer, pero no todos los super­vivientes cumplen con los criterios propuestos por el DSM-V para ser diagnosticados. Esta situación puede provocar la subestimación del problema y además, en este grupo de pacien­tes el TEP se relaciona con diferentes aspectos del bienestar psicológico, como la depresión, la ansiedad o la calidad de vida. Sin embargo, solo hay unas pocas intervenciones psicológi­cas diseñadas para reducir estos síntomas en los supervivientes al cáncer. Método: Se realizó una revisión de los tra­tamientos psicológicos disponibles para el TEP en los supervivientes al cáncer en los últimos 10 años. Las bases de datos utilizadas fueron PubMed, Web of Science (WOS) y PsycInfo con los siguientes descriptores: PTSD (post­traumatic stress disorder), treatment cancer survivors y PTSS (posttraumatic stress symp­toms) treatment cancer survivors. Resultados: Las intervenciones psicológi­cas con una mayor evidencia son: la terapia de tipo cognitivo-conductual y el mindfulness, por delante del entrenamiento en el manejo del estrés, la terapia neuro-emocional, el en­trenamiento en habilidades de afrontamiento y el counseling. Conclusiones: A pesar de la relevancia del TEP en este grupo de pacientes, las interven­ciones psicológicas necesitan de una mayor evidencia para establecer su eficacia para re­ducir estos síntomas en los supervivientes

    La afiliación a CC.OO.: evolución, estructura y trayectorias

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    Informe resultante de la investigación realizada por los autores en base a la explotación de la base de datos de afiliados/as al sindicato español mayoritario, analizando sus principales pautas y evolución temporal, distribución (territorial y sectorial), estructura organizativa y trayectorias

    Procedimiento para la enseñanza de la discriminación entre derecha e izquierda. Estudio de caso para un niño con deficiencia visual y discapacidad intelectual

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    El objetivo del estudio era la enseñanza de la discriminación entre derecha e izquierda a un niño de 7 años con deficiencia visual y discapacidad intelectual. Se abordó la enseñanza desde la perspectiva del análisis de los estímulos implicados en las discriminaciones. El programa de aprendizaje consistió en la enseñanza explícita de una discriminación simple, que incluyó un estímulo, una respuesta y una consecuencia y se probó (test) la transferencia a la discriminación condicional que incluyó dos estímulos, una respuesta y una consecuencia. Los resultados pusieron de manifiesto la transferencia del aprendizaje sin un entrenamiento explícito. El aprendizaje fue mantenido a los seis meses de seguimiento. El procedimiento descrito puede ser un método fácil de aplicar, que reduce el esfuerzo de los participantes.The aim of the research was the teaching of the discrimination between right and lelf in a seven-year-old child with visual impairment and intellectual disability. The teaching was approached from the perspective of the analysis of the stimuli implied in the discriminations. The learning procedure consisted of the explicit teaching of the simple discrimination which included a stimulus, an answer and a consequence testing the transfer to the condicional discrimination that included two stimuli, an answer and a consequence. The results showed the transfer of the learning without an explicit training. The learning was maintained during the six months of the follow-up. The procedure discribed can be a method, easy to apply, that reduces the effort of the participants

    Local interactions under switching costs

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    We study the impact of switching costs on the long-run outcome in 2×2 coordination games played in the circular city model of local interactions. For low levels of switching costs, the predictions are in line with the previous literature and the risk-dominant convention is the unique long-run equilibrium. For intermediate levels of switching costs, the set of long-run equilibria still contain the risk-dominant convention but may also contain conventions that are not risk dominant. The set of long-run equilibria may further be non-monotonic in the level of switching costs, i.e., as switching costs increase the prediction that the risk-dominant convention is the unique long-run equilibrium and the prediction that both conventions are long-run equilibria alternate. Finally, for high levels of switching costs, also non-monomorphic states will be included in the set of long-run equilibria

    Characterizations of perfect recall

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    This paper considers the condition of perfect recall for the class of arbitrarily large discrete extensive form games. The known definitions of perfect recall are shown to be equivalent even beyond finite games. Further, a qualitatively new characterization in terms of choices is obtained. In particular, an extensive form game satisfies perfect recall if and only if the set of choices, viewed as sets of ultimate outcomes, fulfill the Trivial Intersection property, that is, any two choices with nonempty intersection are ordered by set inclusion

    Metastability of Asymptotically Well-Behaved Potential Games

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    One of the main criticisms to game theory concerns the assumption of full rationality. Logit dynamics is a decentralized algorithm in which a level of irrationality (a.k.a. "noise") is introduced in players' behavior. In this context, the solution concept of interest becomes the logit equilibrium, as opposed to Nash equilibria. Logit equilibria are distributions over strategy profiles that possess several nice properties, including existence and uniqueness. However, there are games in which their computation may take time exponential in the number of players. We therefore look at an approximate version of logit equilibria, called metastable distributions, introduced by Auletta et al. [SODA 2012]. These are distributions that remain stable (i.e., players do not go too far from it) for a super-polynomial number of steps (rather than forever, as for logit equilibria). The hope is that these distributions exist and can be reached quickly by logit dynamics. We identify a class of potential games, called asymptotically well-behaved, for which the behavior of the logit dynamics is not chaotic as the number of players increases so to guarantee meaningful asymptotic results. We prove that any such game admits distributions which are metastable no matter the level of noise present in the system, and the starting profile of the dynamics. These distributions can be quickly reached if the rationality level is not too big when compared to the inverse of the maximum difference in potential. Our proofs build on results which may be of independent interest, including some spectral characterizations of the transition matrix defined by logit dynamics for generic games and the relationship of several convergence measures for Markov chains

    In vitro susceptibility of recent antibiotic-resistant urinary pathogens to ertapenem and 12 other antibiotics

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    7 p.Background: The treatment of complicated urinary tract infections may require the use of a parenteral anti-biotic with potent activity against the most common urinary pathogens. Ertapenem is a broad-spectrum 1?-methyl carbapenem with a long plasma half-life that allows administration of a single daily dose. Methods: The purpose of this work was to test the in vitro susceptibility to ertapenem, ampicillin, cefazolin, cefuroxime, cefotaxime, co-amoxiclav, piperacillin/tazobactam, imipenem, gentamicin, amikacin, fosfo-mycin, ciprofloxacin and co-trimoxazole of 482 strains of urinary pathogens of the family Enterobacteriaceae isolated from patients in the community of Madrid (40% from males). The distribution was as follows: Escherichia coli (n = 315), Proteus mirabilis (n = 42), Klebsiella spp. (n = 14) and AmpC-producing Entero-bacteriaceae (n = 111). The strains studied were selected based on their resistance to quinolones and aminoglycosides, and their production of extended-spectrum ?-lactamases (ESBLs) or AmpC-type ?-lacta-mases. Results: All the strains were susceptible to ertapenem, imipenem and amikacin. The MIC90 of ertapenem ranged from a minimum of 0.03 mg/L for Proteus vulgaris and a maximum of 1 mg/L for Enterobacter spp. Ertapenem was the most active of all drugs tested in all cases. On comparing antibiotic resistance among ESBL-producing strains of E. coli (n = 35) and E. coli strains not producing ESBLs (n = 280), statistically significant differences were obtained for ciprofloxacin (P = 0.002) and gentamicin (P = 0.011). Regarding ertapenem, only a slight increase in MIC50 was seen, the value being 0.015 mg/L for strains not producing ESBLs versus 0.03 mg/L for ESBL-producing strains. Conclusions: In view of its significant antibiotic potency against antibiotic-resistant Enterobacteriaceae, ertapenem may constitute a good therapeutic alternative in urinary infections caused by these pathogens

    Intrinsic noise-induced phase transitions: beyond the noise interpretation

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    We discuss intrinsic noise effects in stochastic multiplicative-noise partial differential equations, which are qualitatively independent of the noise interpretation (Ito vs. Stratonovich), in particular in the context of noise-induced ordering phase transitions. We study a model which, contrary to all cases known so far, exhibits such ordering transitions when the noise is interpreted not only according to Stratonovich, but also to Ito. The main feature of this model is the absence of a linear instability at the transition point. The dynamical properties of the resulting noise-induced growth processes are studied and compared in the two interpretations and with a reference Ginzburg-Landau type model. A detailed discussion of new numerical algorithms used in both interpretations is also presented.Comment: 9 pages, 8 figures, to be published in Phys. Rev.
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