Mixed Integer Linear Programming for Feature Selection in Support Vector Machine

This work focuses on support vector machine (SVM) with feature selection. A MILP formulation is proposed for the problem. The choice of suitable features to construct the separating hyperplanes has been modelled in this formulation by including a budget constraint that sets in advance a limit on the number of features to be used in the classification process. We propose both an exact and a heuristic procedure to solve this formulation in an efficient way. Finally, the validation of the model is done by checking it with some well-known data sets and comparing it with classical classification methods.Comment: 37 pages, 20 figure

The stratified p-center problem

This work presents an extension of the p-center problem. In this new model, called Stratified p-Center Problem (SpCP), the demand is concentrated in a set of sites and the population of these sites is divided into different strata depending on the kind of service that they require. The aim is to locate p centers to cover the different types of services demanded minimizing the weighted average of the largest distances associated with each of the different strata. In addition, it is considered that more than one stratum can be present at each site. Different formulations, valid inequalities and preprocessings are developed and compared for this problem. An application of this model is presented in order to implement a heuristic approach based on the Sample Average Approximation method (SAA) for solving the probabilistic p-center problem in an efficient way.Comment: 32 pages, 1 pictur

RNA-Seq analysis for assessing the early response to DSP toxins in Mytilus galloprovincialis digestive gland and gill

[Abstract] The harmful effects of diarrhetic shellfish poisoning (DSP) toxins on mammalian cell lines have been widely assessed. Studies in bivalves suggest that mussels display a resistance to the cytogenotoxic effects of DSP toxins. Further, it seems that the bigger the exposure, the more resistant mussels become. To elucidate the early genetic response of mussels against these toxins, the digestive gland and the gill transcriptomes of Mytilus galloprovincialis after Prorocentrum lima exposure (100,000 cells/L, 48 h) were de novo assembled based on the sequencing of 8 cDNA libraries obtained using an Illumina HiSeq 2000 platform. The assembly provided 95,702 contigs. A total of 2286 and 4523 differentially expressed transcripts were obtained in the digestive gland and the gill, respectively, indicating tissue-specific transcriptome responses. These transcripts were annotated and functionally enriched, showing 44 and 60 significant Pfam families in the digestive gland and the gill, respectively. Quantitative PCR (qPCR) was performed to validate the differential expression patterns of several genes related to lipid and carbohydrate metabolism, energy production, genome integrity and defense, suggesting their participation in the protective mechanism. This work provides knowledge of the early response against DSP toxins in the mussel M. galloprovincialis and useful information for further research on the molecular mechanisms of the bivalve resistance to these toxins.Ministerio de Economía y Competitividad; AGL2012-3089

Coastal Dune Restoration: Trends and Perspectives

Sandy coasts are distributed worldwide and they are all heterogeneous ecosystems in terms of morphology, vegetation, and dynamics. Psammophytes are common in these environments. Besides these widespread attributes, sandy beaches and coastal dunes also share the intense impact of humans. Because of their privileged location at the coast, they are preferred sites for urban and maritime development, destinations for tourists, and locations for many other human activities. Thus, over the years (but especially during the last few decades) many of the previously natural dunescapes have been lost to urban, tourist, and industrial developments. Furthermore, a recurring problem of many coastal dune systems is over-stabilization, which is mostly the result of human actions. The urgent need to preserve the natural and valuable coastal dune remnants and, as much as possible, restore those that have been degraded, is evident. There are many different and contrasting actions that have been followed during restoration activities. Restoration actions have involved “soft” methods, such as sand fences, and “hard” methods, such as geotubes and herbicides. Also, restoration may lead not only to the stabilization of dunes, but also to the re-mobilization of sand. On n overcrowded planet where the coasts are ecosystems to which humans gravitate, conservation and restoration actions become exponentially important

Evaluación de la diversidad genética y estructura poblacional del berberecho "Cerastoderma edule" mediante marcadores microsatélite y de ADN mitocondrial

[Resumen]La conservación, gestión y comprensión de la biología evolutiva de una especie requiere conocer la variación genética existente y cómo se distribuye en las poblaciones. En esta tesis se analizó la variación genética del berberecho Cerastoderma edule, un componente importante del ecosistema costero y un recurso explotado en el litoral europeo, para progresar en la caracterización genética de las poblaciones naturales, tratando de reconocer factores históricos y contemporáneos que pudiesen influir en la distribución de su variación genética. Mediante la construcción de una genoteca enriquecida en secuencias microsatélite se desarrolló el primer panel de marcadores microsatélite en esta especie, optimizándose dos PCRs multiplex para facilitar su análisis. Ello ha permitido aportar las primeras estimas de diversidad genética para la región noroeste de la Península Ibérica, sometida a una intensa explotación, evaluar la estructura de población y proponer las causas de la diferenciación poblacional detectada. Por otra parte, se evaluó la diversidad genética y estructura poblacional a lo largo del ámbito de distribución de la especie y se examinó su historia evolutiva, contrastando los datos genéticos proporcionados por marcadores microsatélite y el gen mitocondrial citocromo b, lo cual ha llevado a identificar tres grupos de poblaciones con signos de patrones evolutivos diferentes.[Resumo]A conservación, xestión e comprensión da bioloxía evolutiva dunha especie require coñecer a variación xenética existente e cómo se distribúe nas poboacións. Nesta tese analizouse a variación xenética do berberecho Cerastoderma edule, un compoñente importante do ecosistema costeiro e un recurso explotado no litoral europeo, para progresar na caracterización xenética das poboacións naturais, tratando de recoñecer factores históricos e contemporáneos que puidesen influír na distribución da súa variación xenética. Mediante a construción dunha xenoteca enriquecida en secuencias microsatélite desenvolveuse o primeiro panel de marcadores microsatélite nesta especie, optimizándose dúas PCRs multiplex para facilitar a súa análise. Isto permitiu aportar as primeiras estimas de diversidade xenética para a rexión noroeste da Península Ibérica, sometida a unha intensa explotación, avaliar a estrutura de poboación e propoñer as causas da diferenciación poboacional detectada. Por outra parte, avaliouse a diversidade xenética e estrutura poboacional ó longo do ámbito de distribución da especie e examinouse a súa historia evolutiva, contrastando os datos xenéticos proporcionados por marcadores microsatélite e o xene mitocondrial citocromo b, o que levou a identificar tres grupos de poboacións con signos de patróns evolutivos diferentes.[Abstract] The conservation, management and understanding of the evolutionary biology of a species require knowing genetic variation and how it is distributed in populations. This work analyzes the genetic variation in the cockle Cerastoderma edule, an important member of the coastal ecosystem and an exploited resource in the European littoral, in order to improve the genetic characterization of natural populations, trying to recognize historical and contemporary factors that might have influenced the distribution of its genetic variation. A microsatellite enriched library was constructed to develop the first set of microsatellite markers and two multiplex PCRs were opimized for ease of analysis. This allowed us to provide the first estimates of genetic diversity in the northwestern Iberian Peninsula, an area under intense exploitation, to evaluate the population structure and to propose the causes of the genetic differentiation detected. Moreover, genetic diversity and population structure throughout the distribution range of the species were assessed and the evolutionary history examined, contrasting genetic data provided by microsatellite markers and the cytochrome b gene. This led to the identification of three groups of populations with signs of different evolutionary

Diseño e implementación de una situación de incertidumbre en una clase de educación infantil

En este trabajo presentamos el diseño y desarrollo de una experiencia didáctica sobre la incertidumbre con estudiantes de Educación Infantil de 5-6 años. El experimento se articula alrededor de la resolución de problemas de probabilidad por simulación y tiene por finalidad valorar hasta qué punto es posible abordar y resolver de esta manera un problema en esta etapa. El experimento se desarrolla en tres fases. La inicial, en la que la maestra presenta la situación; la segunda, en la que cada estudiante lleva a cabo una simulación del problema y proporciona una respuesta; y, la tercera, en la que la maestra pone en común toda la información aportada por los estudiantes. Por lo observado, se concluye que tareas como las que proponemos son posibles en esta etapa educativa, tan vacía de esta clase de contenidos. Se sugiere más experimentación en el sentido en el que se propone aquí

Scale for environmental attitude in physical aActivities in natural environments

La realización de actividades físico-deportivas en el medio natural debe conllevar una actitud de respeto hacia el medioambiente entre los participantes. El objetivo de este artículo es diseñar y validar un instrumento para valorar la actitud ambiental generada en este tipo de prácticas en ámbitos formativos. El cuestionario se concretó en 16 ítems con 5 opciones de respuesta (1, Nada de acuerdo; 5, Muy de acuerdo). Para la validación de la escala se contó con una muestra de 162 estudiantes universitarios de titulaciones relacionadas con la actividad física y el deporte (grado o máster en Ciencias de la Actividad Física y el Deporte), que han cursado alguna asignatura relacionada con las actividades físicas en el medio natural. La fiabilidad obtenida con el α de Cronbach fue de 0.75. Los resultados obtenidos muestran que la escala de actitudes hacia el medioambiente en la práctica de actividades físico-deportivas en el medio natural es un instrumento válido y fiable para valorar la actitud hacia el medioambiente en la participación en actividades físico-deportivas en el medio natural, desde un modelo ecológico. Las conclusiones extraídas, tras su construcción, indican la conveniencia de revisar si las actividades físicas en el medio natural se desarrollan desde una perspectiva sostenible para que, en el caso de que no sea así, se apliquen las estrategias necesarias para su transformaciónEngaging in physical-sport activities in nature should lead to an attitude of respect for the environment among participants. The objective of this article is to design and validate an instrument to assess the environmental attitude generated in this kind of practice within the sphere of training. The questionnaire has 16 items with 5 response choices (1, totally disagree to 5, totally agree). To validate the scale, a sample was used of 162 university students in degrees related to physical activity and sport (Bachelor’s or Master’s in Physical Activity and Sport Sciences) who were taking a course related to physical activities in nature. The reliability obtained with the Cronbach’s α was 0.75. The results show that the scale of attitudes towards the environment in the practice of physical-sport activities in nature is a valid, reliable instrument from an ecological model. After its construction, the conclusions extracted indicate the advisability of checking whether physical activities in nature are carried out from a sustainable perspective so that if they are not, the strategies needed to transform them can be applie

Improvement of olive oil quality: Metabolic, biochemical and molecular analysis of squalene biosynthesis in olive

The virgin olive oil (VOO) is a natural olive juice of special importance in Mediterranean diet due to both its beneficial effects on human health [1] and its exceptional organoleptic properties. These characteristics are due to the presence of the major components, which are the triacylglycerols, and certain groups of compounds encompassed under the term of minor components. Among the minor compounds of VOO, squalene is a polyunsaturated triterpene which is an intermediate metabolite in the synthesis of steroids and terpenoids [2]. In recent years, special attention has been paid to squalene because of the benefits that its ingestion contributes to health. Squalene is considered a natural antioxidant and has been frequently used as an additive to lipid emulsions and as drug carrier in pharmaceutical and vaccine applications. In addition, clinical studies indicate that as a component of olive oil it also has a preventive effect on breast cancer, possesses tumor-protective and a cardio-protective properties [3]. The richest source of squalene is shark liver oil (60% fresh weight), but because of the care protection of marine species concerns, the production of squalene from shark liver oil has been questioned. For this reason, the extraction of squalene from plant species would be of great interest to have a sustainable source of squalene.In this study, the identification of olive genes with a high degree of similarity with the squalene synthase (SQS) genes of the model plant Arabidopsis was carried out from the olive transcriptome and also through the olive genome, both deposited in GenBank  [4, 5]. From the identified sequences, a pair of specific oligonucleotides for each sequence were designed and used to obtain  the full-length cDNA clones  encoding for olive SQS. In addition, we are analyzing the olive SQS genes expression levels in mesocarp and seed during the olive fruit development and ripening by QPCR. Finally, in order to confirm the functional identity of olive SQS cloned genes, we are going to carry out their  functional expression in the bacteria E. coli followed by the biochemical characterization of the corresponding recombinants enzymes.Therefore, the general objetive of this study is to improve the VOO nutritional and technological quality by increasing the squalene content of olive fruit. To achieve this, we focus on the isolation and characterization of the main genes involved in squalene synthesis in olive mesocarp

Analysis and proposals for change in the methodology and evaluation in the European Higher Education Area

En el presente trabajo se analizan los cambios introducidos en la metodología y en la evaluación de la docencia universitaria, mediante un estudio cualitativo, recogiendo datos a través de cuestionarios, entrevistas, análisis de documentos y grupos de discusión. Los participantes en el estudio lo constituye el profesorado (75%) y los estudiantes (85%) implicados en los estudios de Grado. El análisis de los datos se ha realizado mediante una matriz DAFO, obteniendo las fortalezas, debilidades, amenazas y oportunidades derivadas de la actual realidad docente. Los resultados obtenidos muestran la innovación en el uso de metodologías más participativas y de modelos de evaluación formativa, así como las dificultades y resistencias que aparecen ante dichos cambios. Las conclusiones ofrecidas muestran las dificultades encontradas para generar el cambio en la metodología y la evaluación, derivadas tanto de la falta de recursos, como de las condiciones contextuales, o bien, de la concepción tradicional del aprendizaje, entre otras causas. Por contraposición, se destacan los beneficios que supone modificar las prácticas de aprender y de evaluar, repercutiendo en la necesidad de una mejor formación docente, lo que puede generalizarse a otras titulaciones universitariasIn this paper the changes in methodology and evaluation of university teaching, through a qualitative study, collecting data through questionnaires, interviews, document analysis and focus groups are analyzed. Participants in the study are the teachers (75%) and students (85%) involved in graduate studies. The data analysis was performed using a SWOT matrix, obtaining the strengths, weaknesses, threats and opportunities arising from the current educational reality. The results show innovation in the use of more participatory methodologies and models of formative assessment, as well as the difficulties and resistance that appear to such changes. The findings show the difficulties offered to create change in the methodology and evaluation under both the lack of resources, such as the contextual conditions, or, in the traditional conception of learning, among other causes. By contrast, highlights the benefits of changing practices to learn and evaluate, affecting improved teacher training, which can be generalized to other university degree

Análisis comparativo de diferentes aproximaciones para el estudio del proteoma de Saccharomyces cerevisiae

Comunicaciones a congreso