3,466 research outputs found

    Unifying a Geometric Framework of Evolutionary Algorithms and Elementary Landscapes Theory

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    Evolutionary algorithms (EAs) are randomised general-purpose strategies, inspired by natural evolution, often used for finding (near) optimal solutions to problems in combinatorial optimisation. Over the last 50 years, many theoretical approaches in evolutionary computation have been developed to analyse the performance of EAs, design EAs or measure problem difficulty via fitness landscape analysis. An open challenge is to formally explain why a general class of EAs perform better, or worse, than others on a class of combinatorial problems across representations. However, the lack of a general unified theory of EAs and fitness landscapes, across problems and representations, makes it harder to characterise pairs of general classes of EAs and combinatorial problems where good performance can be guaranteed provably. This thesis explores a unification between a geometric framework of EAs and elementary landscapes theory, not tied to a specific representation nor problem, with complementary strengths in the analysis of population-based EAs and combinatorial landscapes. This unification organises around three essential aspects: search space structure induced by crossovers, search behaviour of population-based EAs and structure of fitness landscapes. First, this thesis builds a crossover classification to systematically compare crossovers in the geometric framework and elementary landscapes theory, revealing a shared general subclass of crossovers: geometric recombination P-structures, which covers well-known crossovers. The crossover classification is then extended to a general framework for axiomatically analysing the population behaviour induced by crossover classes on associated EAs. This shows the shared general class of all EAs using geometric recombination P-structures, but no mutation, always do the same abstract form of convex evolutionary search. Finally, this thesis characterises a class of globally convex combinatorial landscapes shared by the geometric framework and elementary landscapes theory: abstract convex elementary landscapes. It is formally explained why geometric recombination P-structure EAs expectedly can outperform random search on abstract convex elementary landscapes related to low-order graph Laplacian eigenvalues. Altogether, this thesis paves a way towards a general unified theory of EAs and combinatorial fitness landscapes

    Fundamentals of DMA

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    Reflections on the educational practice of active Panamanian mathematics teachers

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    Este trabajo tiene como propósito analizar los resultados de una investigación previa en donde se revisan los componentes con baja o nula presencia de los Criterios de Idoneidad Didáctica (CID) en tareas desarrolladas (secuencias didácticas) para un curso de capacitación en la enseñanza de la Matemática. Para recabar información sobre el porqué se obtuvieron dichos resultados se procedió a realizar entrevistas semiestructuradas individuales a cinco maestros participantes de la investigación previa. La entrevista estaba formada por ocho preguntas sobre los componentes conexiones, innovación didáctica, representatividad de la complejidad, errores, utilidad sociolaboral y autonomía. El análisis se realizó a través de un estudio cualitativo de las unidades semánticas de significado (análisis descriptivo). Estas fueron extraídas de las transcripciones de las entrevistas realizadas. Los resultados encontrados revelaron que la mayoría de los entrevistados indican que los componentes como la autonomía y la utilidad sociolaboral generan emociones positivas en sus alumnos. Se concluye que la reflexión de los maestros sobre sus clases de Matemática hasta ese momento consideraba como no prioritarios a los componentes cuya puntuación era baja. Sin embargo, los entrevistados consideraron la importancia de modificar sus prácticas educativas empleando otros componentes de los CID para tener procesos de enseñanza aprendizaje de calidad.The purpose of this document is to analyze the results of previous research where the components with the low or null presence of the Didactical Suitability Criteria (DSC) in developed tasks (didactic sequences) for a training course in the teaching of Mathematics are reviewed. Individual semi-structured interviews were conducted with five teachers who participated in the previous research to gather information on why these results were obtained. The interview consisted of eight questions on the component’s connections, didactical innovation, representativeness of complexity, errors, social-professional practicality, and autonomy. The analysis was conducted through a qualitative study of the semantic units of meaning (descriptive analysis). These were extracted from the transcripts of the interviews guided. The results revealed that most interviewees indicated that components, such as autonomy and social-professional practicality, generate positive emotions in their students. It is concluded that the teachers’ reflection on their mathematics classes up to that time was considered a non-priority for the components whose score was low. However, the interviewees considered the importance of modifying their educational practices by employing other components of the DSCs to have quality teaching and learning processes

    Gender Barriers in Academia: Perceptions of Inequality in Professional Development among Female Academics in the Faculty of Education, University of Alicante, Spain

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    Spanish universities have been implementing gender equality policies for over a decade. The research presented here aims to determine the barriers and challenges perceived by female academics in the Faculty of Education at the University of Alicante. The study used a seven-point Likert-type scale survey consisting of 10 items, which were validated by specialists from different universities. One of the key findings was that often barriers have ceased to be seen as such and are understood instead as a normalized reality. Nevertheless, participants stress that women face greater barriers than men when it comes to reaching top-level positions; highlighting issues such as a lack of mentorship, delayed motherhood, experiencing sexist behavior and comments from male colleagues; and a lack of consensus around measures, such as reconciling work–life balance, as a means of largely eliminating the barriers they face in the university

    Effects of Methotrexate on IL-6alphar, VCAM-1 and NF Kappa B Expression in a Rat Model of Metabolic Syndrome

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    Background: In this study, we used Methotrexate (Mtx) to examine the role of immunomodulation on the activation of IL-6 and VCAM-1, which could generate a microenvironment that supports cardiovascular remodelling.Methods: Male WKY and SHR rats were separated into five groups: Control, FFR: WKY rats receiving a 10% (w/v) fructose solution during all 12 weeks, SHR, FFHR: SHR receiving a 10% (w/v) fructose solution during all 12 weeks and FFHR+Mtx (0,3 mg/kg intraperitoneal one injection per day week for 6 weeks) (n = 8 per group). Metabolic variables and systolic blood pressure were measured. Cardiac and vascular remodelling was also evaluated. To assess this, IL-6R and VCAM-1 immunostaining techniques were used.Results: The FFHR experimental model developed metabolic syndrome, vascular and cardiac remodelling, and vascular inflammation because of increased expression of IL-6 and VCAM-1. Chronic treatment with Mtx completely or partiality reversed the variables studied.Conclusions: The results demonstrated an impact on immunomodulation after mtx treatment, which included a reduction in vascular inflammation and a favourable reduction in metabolic and structural parameters.Fil: Renna, Nicolas Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; ArgentinaFil: Ramirez, Jésica M.. Universidad Nacional de Cuyo. Instituto de Genética; ArgentinaFil: García, Rodrigo Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; ArgentinaFil: Diez, Emiliano Raúl. Universidad Nacional de Cuyo. Instituto de Genética; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Miatello, Roberto Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo. Instituto de Genética; Argentin

    Aproximación a un estudio de las reseñas literarias en diversos suplementos culturales españoles.

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    In this article we have analyzed the most important cultural supplement of the most sold newspapers in our country during three weeks, we have studied the different ways to make literature critic. We wanted to know: what kind of literature is on these publications, how important poetry is nowadays and witches are the most important editorials

    The news gap in the «triple digital agenda»: The different interests of media, audience and networks

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    Digital transformations entail continually reviewing the various Communication models and processes. The influence of the media themselves as agenda setters for an ever more active audience and social networks that select and make certain content they receive viral are also affected by such a convergent context. This current research analyses a model called here the ‘triple agenda’ within the media themselves, in which the journalistic criterion of relevance and their audience’s preferences in the web and the networks travel along different paths. The proposal includes the users and the viral effect as influencing agents in the shape and selection of news, generating a news gap of interests between the media and their audiences. In order to test this model, we study an exploratory case in ElPaís.es, applying a content analysis to the information (n=420) distributed among the online front page, what is most read by the audience in its webpage, and the most viral in its Twitter account. The main objective is to check whether or not these three spheres of relevance operate independently, showing different informative interests f rom the thematic selection that the medium establishes f rom its agenda, its audience and its social networks. The results confirm that there is a gap in the informative interests of the three spheres analysed, especially between the agenda marked by the medium and the interests that are reflected in their web audience, which is more attracted to soft news and the clickbait technique; while there is a greater coincidence of interests between the newspaper’s front page and the users’ selection in their social networks.Las transformaciones digitales conllevan una revisión permanente de los modelos y procesos de la Comunicación. En este contexto convergente también se ve afectada la propia influencia de los medios como fijadores de la agenda frente a una audiencia cada vez más activa y unas redes sociales que seleccionan y viralizan el contenido que les llega. La presente investigación analiza un modelo denominado aquí de ‘triple agenda’ dentro de los propios medios, en los que discurren de manera diferente el criterio periodístico de relevancia y las preferencias de su audiencia en la web y las redes. La propuesta incluye a los usuarios y el efecto de la viralidad como actores influyentes en la conformación y selección noticiosa, generando una brecha, o news gap, de intereses informativos entre el medio y su audiencia. Para poner a prueba este modelo, se recurre a un estudio de caso exploratorio en ElPaís.es, aplicando un análisis de contenido de sus informaciones (n=420), distribuidas entre la portada online, lo más leído por la audiencia en su web y lo más viralizado en su Twitter. El objetivo principal es comprobar si estas tres esferas de relevancia temática operan, o no, de forma independiente, mostrando intereses informativos dispares entre la selección temática que establece el medio desde su agenda, de su audiencia y de las redes. Los resultados confirman una brecha en el interés informativo de las tres esferas analizadas, especialmente entre la agenda que marca el medio y los intereses que reflejan su audiencia web, más atraída por las soft news y las técnicas del clickbait, mientras que existe una mayor coincidencia de intereses entre la portada periodística y la selección de los usuarios en sus redes sociales

    Cystolithiase induite par la migration de la barbe de l’orge des rats (Hordeum murinum) chez 2 chiens mâles

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    Case ReportTwo male dogs were presented with cystic uroliths composed of magnesium ammonium phosphate (struvite). Each had an atypical nidus, a mouse barley awn (Hordeum murinum). To our knowledge, this is the first report of grass awns located in the bladder lumen of dogs. The composition of uroliths and the pathophysiology of grass awn migration to the urinary bladder are discussed.The authors are grateful for the help of Dr. Antonio Javier Sánchez-Rodríguez (Service of Microscopy of Universidad de León) for the scanning electron microscopy study, Prof. Felix Llamas and Prof. Carmen Acedo (Department of Botany of Universidad de León) for the grass awn identification and Dr. Edgardo Soriano-Vargas (CIESA, Universidad Autónoma del Estado de México) for his editorial assistance
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