Assessing convergence across the European Union

Treball Final de Grau en Economia. Codi: EC1049. Curs: 2014/2015This paper assesses the convergence of 131 regions from 13 countries belonging to the European Union. The variable analysed is the log per capita GDP. For the assessment of this convergence we propose two steps: First, in the neoclassical context, the analysis of β and σ convergence. Second, in the time series framework, we analyse convergence based on the deviation of the regions’ GDP from the benchmark, in this case the mean of the group. The gist is to determine whether the deviation is stationary and, therefore, can be taken as an evidence of convergence. In order to test for stationarity, two tests are applied: the ADF and the KPSS tests. Moreover, we have analysed the European regions as a whole, as well as two groups that we consider relevant: the Mediterranean Arc and the Core European region

Modalidades de contratación laboral en el sector agrícola de Castilla y León

Se hace un análisis del sector agrícola de Castilla y León en la actualidad, centrándome en la parte correspondiente a la contratación laboral de dicho sector. El análisis se centra en las modalidades contractuales reguladas en el Estatuto de los Trabajadores clasificándolas según su duración, para observar si hay alguna relación de trabajo especial o si existe algún tipo de contratación especifica en el sector agrario de España y de Castilla y León. Además, se analiza el número de ocupados según el género para determinar si sigue siendo una profesión mayoritariamente masculina, los parados y afiliados a la seguridad social, qué rangos de edad son los que más empleados tiene asociado la agricultura, así como el número, la duración y tipo de contratos empleados en el sector agrícola.Grado en Comerci

Noise Models in Classification: Unified Nomenclature, Extended Taxonomy and Pragmatic Categorization

This paper presents the first review of noise models in classification covering both label and attribute noise. Their study reveals the lack of a unified nomenclature in this field. In order to address this problem, a tripartite nomenclature based on the structural analysis of existing noise models is proposed. Additionally, a revision of their current taxonomies is carried out, which are combined and updated to better reflect the nature of any model. Finally, a categorization of noise models is proposed from a practical point of view depending on the characteristics of noise and the study purpose. These contributions provide a variety of models to introduce noise, their characteristics according to the proposed taxonomy and a unified way of naming them, which will facilitate their identification and study, as well as the reproducibility of future research

Noise simulation in classification with the noisemodel R package: Applications analyzing the impact of errors with chemical data

Classification datasets created from chemical processes can be affected by errors, which impair the accuracy of the models built. This fact highlights the importance of analyzing the robustness of classifiers against different types and levels of noise to know their behavior against potential errors. In this con- text, noise models have been proposed to study noise-related phenomenology in a controlled environment, allowing errors to be introduced into the data in a supervised manner. This paper introduces the noisemodel R package, which contains the first extensive implementation of noise models for classification datasets, proposing it as support tool to analyze the impact of errors related to chemical data. It provides 72 noise models found in the specialized literature that allow errors to be introduced in different ways in classes and attributes. Each of them is properly documented and referenced, unifying their results through a specific S3 class, which benefits from customized print, summary and plot methods. The usage of the package is illustrated through four applica- tion examples considering real-world chemical datasets, where errors are prone to occur. The software presented will help to deepen the understanding of the problem of noisy chemical data, as well as to develop new robust algo- rithms and noise preprocessing methods properly adapted to different types of errors in this scenario.University of Granada/CBU

La geometría sin espacio dentro del aula de clase

Este artículo muestra cómo la Geometría ha perdido interés, desde el comienzo de la historia hasta nuestros días, y lo importante e indispensable que es para la educación en diferentes campos del saber. También muestra la necesidad de capacitar a los docentes de matemáticas en esta área, para así poder llevar este conocimiento y expandirlo en el aula de clase

Managing Borderline and Noisy Examples in Imbalanced Classification by Combining SMOTE with Ensemble Filtering

Imbalance data constitutes a great difficulty for most algorithms learning classifiers. However, as recent works claim, class imbalance is not a problem in itself and performance degradation is also associated with other factors related to the distribution of the data as the presence of noisy and borderline examples in the areas surrounding class boundaries. This contribution proposes to extend SMOTE with a noise filter called Iterative-Partitioning Filter (IPF), which can overcome these problems. The properties of this proposal are discussed in a controlled experimental study against SMOTE and its most well-known generalizations. The results show that the new proposal performs better than exiting SMOTE generalizations for all these different scenarios.Regional Projects P1O-TIC-06858 P11-TIC-9704 P12-TIC-2958 NCN-2013/11/B/5T6/00963National Project TIN2011-28488Spanish Governmen

Sugar-based bicyclic monomers for aliphatic polyesters: a comparative appraisal of acetalized alditols and isosorbide

Three series of polyalkanoates (adipates, suberates and sebacates) were synthesized using as monomers three sugar-based bicyclic diols derived from D-glucose (Glux-diol and isosorbide) and D-mannose (Manx-diol). Polycondensations were conducted in the melt applying similar reaction conditions for all cases. The aim was to compare the three bicyclic diols regarding their suitability to render aliphatic polyesters with enhanced thermal and mechanical properties. The ensuing polyesters had molecular weights (Mw) in the 25,000–50,000 g mol-1 range with highest values being attained for Glux-diol. All the polyesters started to decompose above 300 °C and most of them did not display perceivable crystallinity. On the contrary, they had glass transition temperatures much higher than usually found in homologous polyesters made of alkanediols, and showed a stress– strain behavior consistent with their Tg values. Glux-diol was particularly effective in increasing the Tg and to render therefore polyesters with high elastic modulus and considerable mechanical strength.Peer ReviewedPostprint (published version

Triblock copolyesters derived from lactic acid and glucose: synthesis, nanoparticle formation and simulation

ABA triblock copolyesters were synthesized by ring-opening polymerization (ROP) of l-lactide in solution initiated by a telechelic d-glucose-based polyester macroinitiator. The macroinitiator with a number-average molecular weight about 2500 g mol-1 was synthesized by non-stoichiometric polycondensation in the melt of 2,4:3,5-di-O-methylene-d-glucitol and dimethyl succinate. Two triblock copolyesters of Mn ranging between ~6000 and ~9000 g mol-1, and differing in the length of the polylactide blocks were prepared. These copolyesters started to decompose when heated at ~220 °C and degraded slowly upon aqueous incubation under physiological conditions. They did not display any perceivable crystallinity and showed a single glass transition temperature (Tg) around 60 °C with the higher value corresponding to the larger content in glucitol units. The copolyesters were able to form nanoparticles with average diameters of ~100–130 nm and satisfactory dispersity. The effect of the block lengths on size, ¿-potential values and physical stability of the nanoparticles was evaluated. A molecular dynamics simulation study allowed modelling the two-phase structure of the nanoparticles and evidenced the preference of the glucose-based block to be peripherally located.Peer ReviewedPostprint (author's final draft

Función de biomasa para Acacia caven (Mol.) Mol. distribuida en áreas secas del centro sur de Chile

Acacia caven is a key native species in the dry land region of south-central Chile. It is a species of high social and productive interest to landowners. Therefore, this study proposes a biomass function for A. caven, which involves incorporating predictor variables that are easily obtainable in the field and less complex than those used in already existing functions for the species. Due to the multi-purpose nature of the species and its potential for silvopastoral systems, these functions typify important planning tools to improve the management of this plant resource. To generate the biomass function, the methodology of destructive analysis of components was used on a total of 71 trees. These trees were selected, cut and weighed in the field to generate and test different models. Statistical analysis models were used and root collar diameter, diameter at breast height and total height served as predictor variables, resulting in a good adjustment of the models (R2 adjusted the 0.97 for stem-branches, 0.90 for stems and 0.96 for total biomass), with high correlations between estimated and real values. These functions may be used safely in plant formations of A. caven located in the same distribution area and within the range of the used variables. In the future, however, they require validation with new measurements in other sectors than the area considered to increase geographical representativeness.Acacia caven, es una de las principales especies nativas presentes en el secano interior de la zona central de Chile. Es una especie que tiene un alto interés social y productivo para los propietarios de este recurso. En este sentido, el objetivo de este estudio es proponer una función de biomasa validada para A. caven, y que incorpore variables predictoras de fácil obtención en terreno y de menor complejidad que las consideradas en funciones ya conocidas para la especie. Dadas las características de especie multipropósito y su potencial para su uso en sistemas silvopastorales, estas funciones son importantes herramientas de planificación para mejorar la gestión y manejo de este recurso vegetacional. Para la generación de la función de biomasa, se utilizó una metodología de análisis destructivo por componentes de 71 árboles, los cuales fueron seleccionados, volteados y pesados en terreno, para posteriormente generar y probar diferentes modelos. A través de análisis estadísticos se seleccionaron modelos que utilizan como variables predictoras el diámetro a la altura del cuello, diámetro a la altura del pecho y altura total. Los resultados muestran un buen ajuste de los modelos (R2 ajust. de 0,97 para fuste-ramas, 0,90 para ramillas y 0,96 para biomasa total), lo que indica un alto nivel de correlación entre valores estimados y valores reales. Estas funciones se pueden utilizar con seguridad en formaciones vegetacionales de A. caven que se ubiquen en la misma zona distribucional del recurso y dentro de los rangos de las variables utilizadas, siendo conveniente en el futuro validarlas con nuevas mediciones de sectores distintos al área considerada para estos análisis, aumentando su representatividad geográfica.Fil: Lucero Ignamarca, Alejandro. Universidad de Concepción (Chile)Fil: Muñoz Sáez, Fernando. Universidad de Concepción (Chile)Fil: Cancino Cancino, Jorge. Universidad de Concepción (Chile)Fil: Sotomayor Garreton, Alvaro. Universidad de Concepción (Chile)Fil: Dube, Francis. Universidad de Concepción (Chile)Fil: Villarroel Muñoz, Arnoldo. Universidad de Concepción (Chile)Fil: Sáez Carrillo, Katia. Universidad de Concepción (Chile

Análisis de la neurotoxicidad del β-N-Metilamino-L-Alanina (L-BMAA: estudios en cultivos de neuroblastoma humano (SH-SY5Y) y en cerebelo de rata

Debido a su similitud estructural con el glutamato, el β-N-metilamino-L-alanina (L-BMAA) va a tener una acción excitotóxica causando alteraciones en el interior de las células, como son un incremento del estrés oxidativo, una disfunción mitocondrial, la alteración de la síntesis y degradación proteica y un desequilibrio enzimático puesto que se puede incorporar a proteínas. Las neuronas son células especialmente susceptibles a daños en el plegamiento y la acumulación de proteínas aberrantes dado que no realizan división celular. El cerebelo es un centro motor subcortical que asegura que los movimientos sean realizados con precisión espacial y temporal, con lo cual un daño cerebelar causado por el L-BMAA podría desencadenar una patología neurodegenerativa. El objetivo principal de la presente tesis es analizar la citotoxicidad causada por el L-BMAA en tres sistemas experimentales: un cultivo de neuroblastoma humano (SH-SY5Y) con el que establecimos las bases de la neurodegeneración causada, por otro lado se realizaron ensayos con tratamientos in vivo con L-BMAA en ratas para evaluar la afectación cerebelar y también se llevaron a cabo estudios incubando con L-BMAA cortes de cerebelo para descifrar el mecanismo de acción del tóxico en un sistema en el que poder analizar el papel neuroprotector de moléculas potencialmente terapéuticas como la esfingosina-1-fosfato. Entre las conclusiones obtenidas cabe destacar que las células de neuroblastoma tratadas con L-BMAA, se podrían proponer como un modelo celular para el estudio tanto de los mecanismos de procesos neurodegenerativos, como para el ensayo de moléculas potencialmente terapéuticas. Además, queda demostrado el daño cerebelar causado en ratas tras el tratamiento con L-BMAA. Las ratas afectadas no pueden reestablecer las funciones normales del cerebelo. Y por último, los cortes cerebelo tratados con L-BMAA constituyen un método sencillo y válido para el estudio tanto de mecanismos de procesos neurodegenerativos y para el ensayo de moléculas potencialmente terapéuticas