On the fractional Laplacian and nonlocal operators

The aim of this work is to study certain type of operators that have adquired a renewed relevance in the last decade. This wide class of operators, genericaly called nonlocal operators, appears naturally in many applications in physics, probability, biology and economics. Throughout this work our attention will be focused in a very important nonlocal operator known as the fractional Laplacian. This operator plays a similar role in the theory of nonlocal operators as the one played by the Laplacian in the classical theory of elliptic partial differential equations, i.e. the fractional Laplacian constitutes the most simple and, at the same time, the “model” nonlocal operator and therefore it is considered as the benchmark in the study of these kind of operators. Thus, by analogy, most of the relevant questions associated to the Laplacian (e.g. comparison principles, linear and nonlinear boundary value problems, and regularity results) have an equivalent for the fractional Laplacian. Also, in the same spirit of the multiplicity results for the classical semilinear partial differential equations we prove a multiplicity result for semilinear problems involving the fractional Laplacian using standard variational methods.Maestrí

The role of regions in economic growth

In this paper, we propose a new method to develop multiscalar industrial policies based on a spatially constrained clustering problem, the -innovation ecosystems (-IE) model, that combines aspects of complexity, relatedness, and geography. Our formulation is motivated by recent developments of economic complexity regarding the evolution of economic output through key interactions among industries within economic regions. The objective of this model is to aggregate a set of geographic areas into a prescribed number of regions (so-called innovation ecosystems) such that the resulting regions preserve the most relevant interactions among industries and encourage the emergence of complex industries. We formulate the -IE model as a mixed-integer programming (MIP) problem and propose a heuristic solution approach. We explore a case involving the municipalities of Colombia to illustrate how such a model can be applied and used for policy and regional development

The Autoimmune Tautology: An In Silico Approach

There is genetic evidence of similarities and differences among autoimmune diseases (AIDs) that warrants looking at a general panorama of what has been published. Thus, our aim was to determine the main shared genes and to what extent they contribute to building clusters of AIDs. We combined a text-mining approach to build clusters of genetic concept profiles (GCPs) from the literature in MedLine with knowledge of protein-protein interactions to confirm if genes in GCP encode proteins that truly interact. We found three clusters in which the genes with the highest contribution encoded proteins that showed strong and specific interactions. After projecting the AIDs on a plane, two clusters could be discerned: Sjögren's syndrome—systemic lupus erythematosus, and autoimmune thyroid disease—type1 diabetes—rheumatoid arthritis. Our results support the common origin of AIDs and the role of genes involved in apoptosis such as CTLA4, FASLG, and IL10

O perfil competitivo local como fator determinante para o desenvolvimento da floricultura em Madrid-Cundinamarca

This article describes the competitive profile attributes of municipality of Madrid and establishes the relations that, with such profile, development of flower crops have had in its territory. The document begins describing the current situation of floriculture industry in the country. Then, after establishing the determinants proposed from theory to measure competitiveness in a territory, analyses the particular case of municipality of Madrid and defines the competitiveness attributes that characterize it. Finally, the relations among competitive profile and floriculture are presented, showing how it became a determinant factor for the development of this economic activity. The article conclusions are preceded by the presentation of the elements that represent major strengthen for economic development of the municipality in the future.Este artículo describe los atributos del perfil competitivo del municipio de Madrid y establece las relaciones que, con dicho perfil, ha tenido el desarrollo de cultivos de flores. Se parte de la descripción de la situación actual de la industria de la floricultura en el país. Después, tras establecer los determinantes que desde la teoría se han propuesto para medir la competitividad de un territorio, se analiza el caso particular del municipio de Madrid y define los atributos competitivos que lo caracterizan. Se presentan las relaciones entre el perfil competitivo del municipio y la floricultura, mostrando cómo aquél, se convirtió en un factor determinante para dicha actividad económica. Finalmente se presentan las conclusiones del artículo, las cuales son antecedidas por la presentación de los elementos que representan la mayor fortaleza para el desarrollo económico del municipio en el futuro.Este artigo descreve as características do perfil competitivo no municipio de Madri, Colombia, e es-tabelece as relagóes de referido perfil com o desenvolvimento de cultivos de flores em seu territorio. O documento parte da descrigao da situagao atual da industria da floricultura no país, estabelece os pontos determinantes propostos para medir a competitividade de um territorio, analisa o caso particular do municipio de Madri e define as características competitivas que o caracterizam. Finalmente, apresenta as relagóes entre o perfil competitivo do municipio e a floricultura, mostrando como aquele se converteu num fator determinante para o desenvolvimento desta atividade economica. As conclusóes do artigo sao antecedidas pela apresentagao dos elementos que representam a maior fortaleza para o desenvolvimento economico do município no futur

Propuesta de un plan estratégico de ventas para la empresa MG FUMIGACIONES S.A.S.

Diseñar un plan estratégico de marketing (ventas) para la empresa MG FUMIGACIONES S.A.S., que permita desarrollar de manera eficiente la proyección de su crecimiento económico.El presente trabajo de investigación tiene como objetivo principal, evaluar la calidad del servicio y la satisfacción al cliente de la empresa MG FUMIGACIONES S.A.S, ubicada en la ciudad de Copacabana (Antioquia). Esta propuesta ayuda a intervenir con un plan de mejora en las ventas con el fin de conocer las percepciones y expectativas de los clientes, con respecto al servicio ofrecido por la empresa. La investigación se desarrolla de forma cuantitativa, experimental y práctica, realizando un plan estratégico de ventas enfocado en mejorar los servicios y la productividad de la empresa, posicionándose en un buen puesto en el mercadeo actual, el cual induce a la diferencia entre la visión, recepción de la calidad en el servicio menos las expectativas del mismo. Para ello se utilizará el método descriptivo, investigativo, cuantitativo y cualitativo; se consideró de vital importancia la toma de datos de la cámara de comercio, sobre cómo están actualmente las estadísticas de las empresas, contra el control de plagas en el mercado actual de la ciudad. Los resultados que arrojó la investigación, estuvieron muy marcados hacia la tendencia de que la percepción de la calidad del servicio ofrecida por MG Fumigaciones S.A.S, es inferior a las expectativas de los clientes y referente a las otras empresas actuales. Sus resultados más relevantes se dan en las dimensiones de fiabilidad y capacidad de servicios ofrecidos por la empresa, donde se ven objetivos económicos negativos, los cuales deben ser minimizados y para llegar a eso, se debe mejorar cada uno de los procesos de marketing, plan de ventas y dar responsabilidades a cada área que tiene contacto con el cliente

The Autoimmune Tautology: An In Silico Approach

There is genetic evidence of similarities and differences among autoimmune diseases (AIDs) that warrants looking at a general panorama of what has been published. Thus, our aim was to determine the main shared genes and to what extent they contribute to building clusters of AIDs. We combined a text-mining approach to build clusters of genetic concept profiles (GCPs) from the literature in MedLine with knowledge of protein-protein interactions to confirm if genes in GCP encode proteins that truly interact. We found three clusters in which the genes with the highest contribution encoded proteins that showed strong and specific interactions. After projecting the AIDs on a plane, two clusters could be discerned: Sjögren’s syndrome—systemic lupus erythematosus, and autoimmune thyroid disease—type1 diabetes—rheumatoid arthritis. Our results support the common origin of AIDs and the role of genes involved in apoptosis such as CTLA4, FASLG, and IL10

NClassG+: A classifier for non-classically secreted Gram-positive bacterial proteins

<p>Abstract</p> <p>Background</p> <p>Most predictive methods currently available for the identification of protein secretion mechanisms have focused on classically secreted proteins. In fact, only two methods have been reported for predicting non-classically secreted proteins of Gram-positive bacteria. This study describes the implementation of a sequence-based classifier, denoted as NClassG+, for identifying non-classically secreted Gram-positive bacterial proteins.</p> <p>Results</p> <p>Several feature-based classifiers were trained using different sequence transformation vectors (frequencies, dipeptides, physicochemical factors and PSSM) and Support Vector Machines (SVMs) with Linear, Polynomial and Gaussian kernel functions. Nested <it>k</it>-fold cross-validation (CV) was applied to select the best models, using the inner CV loop to tune the model parameters and the outer CV group to compute the error. The parameters and Kernel functions and the combinations between all possible feature vectors were optimized using grid search.</p> <p>Conclusions</p> <p>The final model was tested against an independent set not previously seen by the model, obtaining better predictive performance compared to SecretomeP V2.0 and SecretPV2.0 for the identification of non-classically secreted proteins. NClassG+ is freely available on the web at <url>http://www.biolisi.unal.edu.co/web-servers/nclassgpositive/</url></p

Validating subcellular localization prediction tools with mycobacterial proteins

<p>Abstract</p> <p>Background</p> <p>The computational prediction of mycobacterial proteins' subcellular localization is of key importance for proteome annotation and for the identification of new drug targets and vaccine candidates. Several subcellular localization classifiers have been developed over the past few years, which have comprised both general localization and feature-based classifiers. Here, we have validated the ability of different bioinformatics approaches, through the use of SignalP 2.0, TatP 1.0, LipoP 1.0, Phobius, PA-SUB 2.5, PSORTb v.2.0.4 and Gpos-PLoc, to predict secreted bacterial proteins. These computational tools were compared in terms of sensitivity, specificity and Matthew's correlation coefficient (MCC) using a set of mycobacterial proteins having less than 40% identity, none of which are included in the training data sets of the validated tools and whose subcellular localization have been experimentally confirmed. These proteins belong to the TBpred training data set, a computational tool specifically designed to predict mycobacterial proteins.</p> <p>Results</p> <p>A final validation set of 272 mycobacterial proteins was obtained from the initial set of 852 mycobacterial proteins. According to the results of the validation metrics, all tools presented specificity above 0.90, while dispersion sensitivity and MCC values were above 0.22. PA-SUB 2.5 presented the highest values; however, these results might be biased due to the methodology used by this tool. PSORTb v.2.0.4 left 56 proteins out of the classification, while Gpos-PLoc left just one protein out.</p> <p>Conclusion</p> <p>Both subcellular localization approaches had high predictive specificity and high recognition of true negatives for the tested data set. Among those tools whose predictions are not based on homology searches against SWISS-PROT, Gpos-PLoc was the general localization tool with the best predictive performance, while SignalP 2.0 was the best tool among the ones using a feature-based approach. Even though PA-SUB 2.5 presented the highest metrics, it should be taken into account that this tool was trained using all proteins reported in SWISS-PROT, which includes the protein set tested in this study, either as a BLAST search or as a training model.</p

Moravia como ejemplo de transformación de areas urbanas degradadas: tecnologías apropiadas para la restauración integral de cuencas hidrográficas.

Postprint (published version

Razonamiento covariacional en estudiantes de quinto grado

Se presenta un avance de una investigación de tipo cualitativo en la cual se busca identificar las características de razonamiento presentadas en estudiantes de grado quinto al momento de enfrentarse a situaciones de tipo variacional; dichas características se discuten a la luz del marco conceptual para la covariación propuesto por Carlson, Jacobs, Coe, Larsen, y Hsu (2003). Desde las situaciones, se desprenden algunas implicaciones y recomendaciones para su implementación en el aula de clase, específicamente para un acercamiento a nociones como: función y tasa de variación, las cuales se encuentran en las bases propias del razonamiento covariacional y pueden abordarse desde los primeros grados de escolaridad como una manera de crear cimientos en la comprensión de los conceptos más relevantes del cálculo