On D-brane configurations and ADS/CFT duality

Tesis doctoral por el sistema de Compendio de PublicacionesString theory has been a considerable conceptual and mathematical advance in the search for the most fundamental theory of physics. The idea started in the 1960's, by considering the smaller constituents of matter as one-dimensional objects represented by vibrant strings, in an attempt to describe the strong interaction. The attempt failed, but years later, string theory was recovered and has been developed as a possible unification theory in which numerous advances continue to take place nowadays, and which would encompass all known matter particles and interactions. In this thesis two independent research works in the area of string theory are presented. The first one falls in the context of the unstable non-BPS configurations, while the other has to do with the particle-like branes appearing in relation to the AdS/CFT conjecture. After a general introductory chapter to the strings, branes and dualities, each research work appears in a separate part of the thesis (parts I, II). Conclusions are given at the end of each part. In the first part we introduce certain unstable non-BPS brane configurations, the non-BPS Dp-branes and the (Dp,anti-Dp) systems. Their instability is reflected in the presence of tachyonic modes in their string spectra. These tachyonic modes can decay (`condense') giving rise to a new configuration, which can in turn be stable or not. The boundary state formalism is introduced, as well as an effective potential approach, in order to tackle the problem and lay the basis for the research work presented in this first part. That research is presented as an adaptation of [1]. In this work we present a worldvolume effective action suitable for the study of the confined phase of a (Dp,anti-Dp) system at weak coupling. We identify the mechanism by which the fundamental string arises from this action when the Dp and the anti-Dp annihilate. We also construct an explicit dual action, more suitable for the study of the strong coupling regime. Our dual description indicates that the condensing tachyonic objects originate from open D(p-2)-branes stretched between the brane and the antibrane. In the second part of the thesis we present the most relevant results from the particle-like branes appearing in relation to AdS/CFT. These configurations are made of branes living in the bulk of AdS and a certain number strings stretched all the way to the boundary, where they are seen as external quarks. We review the stability study of the baryon vertex in the AdS5 x S5 background and how this configuration was generalized by introducing a magnetic flux. We also comment on the Di-baryon configurations that appear in the same context. Finally and before presenting [2], we explain the basis of the ABJM theory, an AdS/CFT proposal realized over an AdS4 space and related to a three dimensional supersymmetric Chern-Simons matter theory. In [2] we study the effect of adding lower dimensional brane charges, generalizing the particle-like brane configurations that appears in AdS4 x P3. We show that these configurations require additional fundamental strings in order to cancel certain worldvolume tadpoles appearing. A dynamical study reveals that the charges must lie inside some interval in order to find well defined configurations, and for the baryon vertex and the di-baryon, the number of fundamental strings must also lie inside an allowed interval. We also discuss how these configurations are modified in the presence of a non-zero Romans mass. [1] N. Gutierrez, Y. Lozano, Phys. Rev. D79 (2009) 046010, arXiv:0809.1005 [hep-th] [2] N. Gutierrez, Y. Lozano, D. Rodriguez-Gomez, JHEP 1009 (2010) 101, arXiv:1004.2826 [hep-th]

Gene–Gene Interaction based Clustering method for Microarray Data

In this paper, we propose a greedy clustering algorithm to identify groups of related genes and a new measure to improve the results of this algorithm. Clustering algorithms analyze genes in order to group those with similar behavior. Instead, our approach groups pairs of genes that present similar positive and/or negative interactions. In order to avoid noise in clusters, we apply a threshold, the neighbouring minimun index(λ), to know if a pair of genes have interac tion enough or not. The algorithm allows the researcher to modify all the criteria: discretization mapping function, gene– gene mapping function and filtering function, and even the neighbouring minimun index, and provides much flexibility to obtain clusters based on the level of precision needed. We have carried out a deep experimental study in databases to obtain a good neighbouring minimun index, λ. The performance of our approach is experimentally tested on the yeast, yeast cell-cycle and malaria datasets. The final number of clusters has a very high level of customization and genes within show a significant level of cohesion, as it is shown graphically in the experiment

Effect of the synthesis method on the performance of Ni-CeO2-ZrO2 catalysts for the hydrogenolysis of glycerol with endogenous hydrogen

In this work, we investigated the influence of the synthesis method of Ni-based CeZr catalysts on their physicochemical and catalytic properties in the hydrogenolysis (HDO) of glycerol with H2 in-situ produced by the aqueous-phase reforming (APR). Conventional impregnation method involved surface nickel deposition (NiCeZr-IM). The one-pot methods, which involved nickel embedment into CeZr lattice, included sol-gel (NiCeZr-SC) and coprecipitation (NiCeZr-CA and ultrasound-assisted NiCeZR-CS) methods. Differences in textural, structural, morphological, redox, and surface properties, together with and catalytic performance in the glycerol APR-HDO, were investigated systematically. As well, spent catalysts were deeply characterized. There were notable differences among textural properties, which significantly affected their activity in glycerol conversion. The structural characterization confirmed the successful integration of Ni into the CeZr lattice, especially for the catalysts synthesized using one-pot methods. One-pot synthesized catalysts showed stronger Ni-CeZr interaction, which affect the reducibility. The catalysts prepared by coprecipitation contained the highest metal-to-acid ratio, making them very active for C-O bond hydrogenation. Post-reaction characterization discloses a leaching of the nickel, in greater amount for both coprecipitated catalysts. This study revealed the potential of Ni-based catalysts derived from subsurface insertion of nickel into the CeZr matrix for the hydrogenolysis of glycerol without external hydrogen.Ministerio de Ciencia e Innovación, PID2019-106692RB-I0

Manejo de la disrupción escolar generadora de conflicto en la Institución Educativa Departamental Agroindustrial Santiago de Chocontá e Institución Educativa Municipal Rural Río Frío de Zipaquirá

91 PáginasEl proyecto de investigación se realizó en la Institución Educativa Departamental Agroindustrial Santiago de Chocontá (IEDASCH) y en la Institución Educativa Municipal Rural Río Frío (IEMRRF) de Zipaquirá. Ambas son de carácter público y con jornada única. Su población estudiantil presenta características similares en cuanto a origen rural, estratificación y actividad económica agropecuaria de sus familias, con empleos informales o temporales en empresas productoras de flores. En el nivel de básica secundaria (6° a 9°) se presentan frecuentemente conductas que afectan negativamente los procesos académicos y de convivencia, y alteran las relaciones interpersonales y el respeto por los acuerdos establecidos en las instituciones educativas. El objeto de la investigación es la identificación de las conductas disruptivas que se presentan con mayor frecuencia y plantear recomendaciones estratégicas para su manejo adecuado. Para llegar a ello se realizó una investigación de tipo aplicado, con enfoque cualitativo y diseño etnográfico, con alcance explicativo, siendo la encuesta, el grupo focal y la observación los instrumentos empleados en la recolección de información

Articulation of the didactics of social sciences, language, and virtuality : a relation under construction

RESUMEN: Los autores intentan establecer la relación entre la didáctica general, la didáctica de las ciencias sociales, la didáctica de la lengua y la didáctica de la virtualidad, desde la posición de diferentes teóricos, como Álvarez y González (2002), Camilloni (2008), Camps (2004) Benejam y Pagés (2004), que se han dedicado a pensar el concepto y el problema de la didáctica como uno de los elementos fundamentales en los procesos de enseñanza y aprendizaje. Asimismo, logran trascender las concepciones del sentido común y las intuiciones sobre la didáctica, pues se piensa que ella solo se circunscribe a los medios utilizados en la enseñanza, integran en el aula estas concepciones, en un esbozo de propuesta de articulación de las didácticas trabajadas, dirigidas a los docentes en ejercicio, y elaboran, finalmente, algunas conclusiones al respecto.ABSTARCT: The authors are trying to establish the relationship between general didactics, didactics of social sciences, the teaching of the language and the teaching of virtuality, from the position of different theorists like Alvarez y Gonzalez (2002), Camilloni (2008), Camps (2004) Benejan and Pages (2004), who have dedicated themselves to think of the concept and the problem of teaching as one of the key elements in the processes of teaching and learning. Also, manage to transcend notions of common sense and insights about teaching, because it is thought she only is confined to the media used in education, integrate these conceptions, in an outline of proposal for articulation of the didactic worked, aimed at teachers in-Office, in the classroom and develop, finally, some conclusions thereon

Síntesis y caracterización de alúminas de transición a partir de desechos de aluminio reciclado

El objetivo de este estudio fue desarrollar una metodología alterna para sintetizar alúminas de transición, partiendo de aluminio reciclado como materia prima (latas de bebidas gaseosas), a fin de disminuir los efectos ecológicos de este tipo de desecho y generar un producto de alto valor agregado. Con el método de síntesis implementado se obtiene un precursor conformado en un 55.4 % por bayerita, 41.2 % por bohemita y el resto por sal de amonio, de acuerdo con los estudios de rayos X realizados y la cuantificación por el método de Rietveld. La sal cloruro de amonio generada no es relevante para el proceso manejado, ya que su alta solubildad en agua permite eliminarla por lavados sucesivos. Estudios realizados por microscopia electrónica de barrido muestran la presencia de partículas aglomeradas con tamaños de 50 a 300 μm. Utilizando ensayos de granulometría laser, se determinó una distribución bimodal del tamaño de grano. El análisis térmico indicó una pérdida de masa del 40.6 % en peso respecto de la muestra inicial del precursor al llevar la muestra a temperaturas cercana a los 1000 ºC. Tratamientos térmicos a 350 y 750 ºC realizados al precipitado obtenido, manteniendo la temperatura durante 1, 2 y 4 h, permitieron obtener varias alúminas de transición (γ, η, θ), que son productos con valor agregado que tienen usos potenciales como aglutinantes para refractarios monolíticos, soportes catalíticos o aditivos como materiales puzolánicos.The aim of this study was to develop an alternative methodology for the synthesis of transition aluminas, in order to reduce ecological costs by using recycled metal scrap as raw material (cans of soft drinks) and generate a product with high added value. The synthesis technique employed yielded a precursor comprised of 55.4 % of bayerite, 41.2 % of boehmite, and ammonium salt, according the characterization performed with X-ray diffraction and quantification by the Rietveld method. The ammonium chloride salt present is not relevant for the process, since given its solubility in water, it could be eliminated by successive washing. Scanning electron microscopy evaluations showed the presence of agglomerates of particles between 50 and 300 μm. A bimodal grain sizes distribution was detected during the laser granulometric test. Thermogravimetric analysis of the precursor indicated a 40.6 % total weight loss at 1000 ºC. The heat treat-ments at 350 and 750 ºC of precipitates for 1, 2 and 4 h, produced various transition aluminas (γ, η, θ), which are products where value has been added and might have a potential use as binders in monolithic products, catalyst support, or additives for puz-zolanic materials, among others.Fil: Rodríguez, Rosa María. Universidad Metropolitana; VenezuelaFil: Gutiérrez Campos, Delia. Universidad Simón Bolívar; VenezuelaFil: Saab, Elvira. Universidad Simón Bolívar; VenezuelaFil: Labrador, Norberto. Universidad Simón Bolívar; VenezuelaFil: Hung Hung, Yuk Ming Xavier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Palma, Carlos. Universidad Simón Bolívar; Venezuel

Social and environmental Impact of the Scientific and Technical Advances in the Use of Antimicrobials

La terapéutica de enfermedades transmisibles ha evolucionado en la historia, ocupan las primeras causas de morbilidad. El presente artículo analiza el impacto socioambiental de adelantos científicos – técnicos, en el uso de antimicrobianos. El objetivo es argumentar la connotación de los progresos de la ciencia y la tecnología en el campo de la terapéutica antimicrobiana, para el medio ambiente. Se realiza un análisis contrastado de las influencias positivas y negativas de los avances, en el campo de la terapéutica antimicrobiana, en bases de datos PubMed y Google Académico, en los meses de enero a octubre del 2021. Los criterios de selección fueron: artículos con acceso gratuito al texto completo, publicados en español e inglés, excluidos los estudios duplicados, otros de calidad científica baja, son evaluados a través de la lectura crítica y especializada. El uso indiscriminado de antimicrobianos conduce a la resistencia y multirresistencia.The therapeutic of transmissible diseases has evolved in history, they occupy the first causes of morbidity.  The present article analyzes the social and environmental impact of the scientific and technical advances, in the use of antimicrobials. The objective is to argue the connotation of the advances of science and technology in the field of the antimicrobial therapeutic, for the environment. A contrasted analysis of the positive and negative influences of the advances, in the field of the antimicrobial therapeutic was carried out in data bases such as PubMed and Google Scholar, from January to October, 2021. The selection criteria were: articles with free access to whole text, published in Spanish and English, the copies of studies were excluded, and others of low scientific quality are evaluated through a critical and specialized reading. The indiscriminate use of antimicrobials conducts to the resistance and multi-resistance

Impacto social y ambiental de los adelantos científico técnicos en el uso de antimicrobianos

La terapéutica de enfermedades transmisibles ha evolucionado en la historia, ocupan las primeras causas de morbilidad. El presente artículo analiza el impacto socioambiental de adelantos científicos – técnicos, en el uso de antimicrobianos. El objetivo es argumentar la connotación de los progresos de la ciencia y la tecnología en el campo de la terapéutica antimicrobiana, para el medio ambiente. Se realiza un análisis contrastado de las influencias positivas y negativas de los avances, en el campo de la terapéutica antimicrobiana, en bases de datos PubMed y Google Académico, en los meses de enero a octubre del 2021. Los criterios de selección fueron: artículos con acceso gratuito al texto completo, publicados en español e inglés, excluidos los estudios duplicados, otros de calidad científica baja, son evaluados a través de la lectura crítica y especializada. El uso indiscriminado de antimicrobianos conduce a la resistencia y multirresistencia

Análisis del proceso de capacitación profesional que se imparte en la Corporación Universitaria Minuto de Dios-UNIMINUTO VRO sede Villavicencio y su incidencia en la formación de profesionales gerenciales competentes en Administración de Empresas acorde a las exigencias del campo empresarial de la cuidad.

Analizar el perfil Profesional y Laboral del Administrador de empresa de la universidad de Cartagena que requiere el sector empresarial.El presente trabajo abarca una serie de conceptos y procesos en la búsqueda de soluciones prácticas para el buen desarrollo de la educación en la formación de los administradores de empresas mediante el análisis de la capacitación implantada desde su academia, en este caso la Corporación Universitaria MINUTO de Dios UNIMINUTO VRO sede Villavicencio, con el fin de reconocer los profesionales competentes exigidos por el campo empresarial de esta ciudad, teniendo en cuenta sus necesidades, los conceptos ofertados y los posibles vacíos que se presenten durante la formación del profesional. Se emplean conceptos desde bases teóricas como Peter Drucker, Edimer Tobar quienes con sus aportes en base a competencias gerenciales nos dan el respaldo para dar continuidad en la búsqueda de las competencias requeridas por el Administrador de empresas UNIMINUTO, trabajando bajo una línea investigativa mixta descriptiva y correlacional haciendo uso de la población estudiantil del plantel educativo y la población empresarial de la ciudad, por medio de instrumentos de tipo encuesta y entrevista que nos darán la información necesaria y precisa para el análisis de este proceso de capacitación impartido y su incidencia en los profesionales, dando resultados que pueden ser a futuro fuentes de investigaciones innovadoras en educación, transformación social aportando posibles soluciones de problemas locales por medio de la academiaThe present work covers a series of concepts and processes in the search for practical solutions for the good development of education in the training of business administrators by analyzing the training implemented from their academy, in this case the MINUTE University Corporation of God UNIMINUTO VRO headquarters Villavicencio, in order to recognize the competent professionals required by the business field of this city, taking into account their needs, the concepts offered and the possible gaps that arise during the training of the professional. Concepts are used from theoretical bases such as Peter Drucker, Edimer Tobar who have their contributions based on managerial competencies give us the support to give continuity in the search for the competences required by the UNIMINUTO Business Administrator, working under a descriptive mixed research line and correlational making use of the student population of the educational establishment and the business population of the city, through survey and interview instruments that give us the necessary and accurate information for the analysis of this training process and its impact on professionals, giving results that can be a future source of innovative research in education, social transformation providing possible solutions to local problems through the academy