Gene regulatory evolution and the origin of complex behaviors in the prairie vole, Microtus ochrogaster

Understanding variation in form and behavior within and among species requires mapping genotypes to phenotypes. Much of this variation depends on differences in regulatory DNA scattered throughout the genome; in the context of behavior, these regulatory sequences govern gene expression in regions of the brain that shape behavior. Surprisingly few studies have characterized the regulatory changes that underlie the adaptive evolution of brain and behavior. In my PhD dissertation project, I investigated the adaptive role of gene regulation in the evolution of pair-bonding and sexual fidelity in the prairie voles, Microtus ochrogaster. Expression of Avpr1a in the ventral pallidum plays a critical role in the origin and evolution of pair-bonding in these monogamous voles. In Chapter 1, I have applied phylogenetic and population genetic methods to find signatures of selection in functional elements in the prairie vole genome. I identified a regulatory element of the Avpr1a locus that is under positive selection, this sequence coincides with the origins of expression of this gene in a reward region, the ventral pallidum. Then, I tested its causality using transgenic mouse enhancer assays. I found that transgenic mice expressing a reporter under the control of this prairie vole enhancer were able to drive expression in the ventral pallidum, but expression was sensitive to insertion site. Interestingly, this gene also shows profound differences between individuals. In Chapter 2, I applied population genomic tools to demonstrate that this locus shows signatures of balancing selection in a polymorphic enhancer that predicts expression in a spatial memory circuit. I found that alleles that predict aspects of space use and sexual fidelity are strongly linked to each other. Moreover, I show evidence that the evolution of this regulatory element seems to be mediated by a mix of balancing, epistatic and density-dependent selection. In Chapter 3, I performed RNA-sequencing experiments to analyze monogamy-related genomic changes in the brain. I found massive changes in gene expression of prairie voles in contrast to promiscuous meadow voles, despite their gene expression modules are very well preserved. Moreover, neuroplasticity –a neural process involved with learning— was strongly activated in prairie but not it meadow vole brains. Overall, the results of these experiments reveal the potential for gene regulation to drive the adaptive evolution of complex behaviors.Ecology, Evolution and Behavio

Plan parcial de desarrollo quebrada Bolonia: proyecto barrio Compostela, Bogotá

Trabajo de gradoEl contenido del trabajo va enfocado a la proyeccion de elementos que van desde lo urbano a lo constructivo dirigido al planteamiento de la arquitectura participativa permitiendo configurar y generando diferentes patrones urbanos, de espacialidad y constructivos, los cuales son determinantes para garantizar la calidad de vida al usuario. Además nos muestra la arquitectura a manera de solución a problemáticas marcadas en barrios de distinta índole con deficiencias marcadas tanto socialmente como estructuralmente a manera de barrio-ciudad.INTRODUCCIÓN 1. OBJETIVOS 2. PLANTEAMIENTO DEL PROBLEMA Y PREGUNTAS 3. MARCO TEÓRICO 4. ASPECTOS DEL LUGAR DE INTERVENCIÓN 5. DESCRIPCIÓN Del BRIEF 6. ANÁLISIS DE REFERENTES 7. PROYECTO 8. CONCLUSIONES BIBLIOGRAFÍA ANEXOSPregradoArquitect

Evaluación de marcador para virus papiloma humano en mujeres con informes de papanicolau de células escamosas atípicas sugerentes de lie alto grado o ca. invasor (H2)

Tesis (Tecnólogo Médico)El presente trabajo corresponde al proyecto FONIS SA 12/2035 el cual consiste en la determinación de la presencia del virus papiloma humano (HPV) en 78 pacientes femeninas del sector sur de Santiago, que presentaron un PAP Atípico escamoso que no excluye lesión intraepitelial de alto grado (ASC-H). La identificación de la presencia o ausencia del HPV se realizará por medio de técnicas moleculares (PCR). A su vez a las pacientes se les realizará un PAP de rutina para determinar, por vía citológica, si existen o no hallazgos de HPV y/o patologías cervicouterinas

Estructura de capital en Pymes: estudio de caso de empresa colombiana

La estructura de capital de una empresa está determinada por el conjunto de decisiones financieras que la administración toma día a día, con las que debe procurar mantener liquidez, ser rentable en el tiempo y generar valor -- No existe una fórmula de combinación ideal, pues cada empresa está sujeta a sus condiciones particulares -- Por ejemplo, un endeudamiento alto puede ser bueno para unas empresas y perjudicial para otras, una inversión puede representar un riesgo bajo para ciertas empresas y alto para otras; entre diversos aspectos que varían según el tipo de empresa, su entorno, los objetivos que establezca la administración y las estrategias que implementen -- En este sentido, el objetivo del estudio es crear un modelo que permita realizar un análisis de la estructura de capital de la empresa D&G Grupo Mundial S.A.S., así como establecer cuál sería la estructura de capital óptima para ella a partir del comportamiento histórico de indicadores financieros y variables macroeconómicasThe capital structure of a company is determined by the set of financial decisions that administration takes day by day, in order to maintain liquidity, be profitable in time and generate value -- While the generation of value is the main objective of any organization, there is no magic formula to define an ideal financial structure for a company, clarifying that the financial structure is given by a balance between funding sources and forms investment -- High indebtedness may be good for some companies and harmful for others, an investment may represent a low risk for some companies and high for others; among different aspects that vary according to the type of company, its environment, the objectives that the administration establishes and the strategies implemented -- This paper focuses on the capital structure of D&G Grupo Mundial S.A.S., as well as to establish the optimal capital structure for this company and macroeconomic variable

Análisis energético y exergético de una planta de cogeneración del sector azucarero asistida por colectores solares

En este trabajo se presenta un análisis de una planta de cogeneración de la industria azucarera de Colombia, aprovechando una fuente de energía renovable a través de colectores solares. Este análisis se realiza con el fin de aumentar la temperatura del fluido de trabajo a la entrada de los generadores de vapor, y así reducir las diferencias de temperatura entre la entrada y la salida de estos dispositivos, logrando una reducción en el consumo de combustible. La investigación se desarrolla mediante un análisis energético y exergético con base en un modelo termodinámico que representa la operación de la planta en régimen permanente. Se evalúa la vinculación de dos tipos de colectores solares: Cilindro-Parabólico (CCP) y Lineal-Fresnel (CLF), cada uno modelado de manera independiente. La inclusión de los sistemas de recolección solar en el ciclo de cogeneración de la planta de la industria azucarera presenta posibilidades de mejora en el proceso, ya que aumenta tanto su eficiencia energética como su eficiencia exergética, debido a la disminución en el consumo de combustible. Los resultados muestran que aumenta la eficiencia energética de un 68,71% a un 75% aproximadamente con los sistemas de recolección solar; 74,86% con CCP y 75,17 % con CLF. En cuanto a la eficiencia exergética, se pasa de un 46,47 % a 50,7 % con CCP y 50,83 % con CLF, disminuyendo hasta un 2,1% de exergía destruida en la planta. En consumo de combustible, se logra una disminución hasta del 8,6 % con CLF y del 8,35 % con el CCP, reflejando un ahorro de hasta 5000 toneladas de combustible al año

Molecular phylogenetics, evolution of sexual systems and historical biogeography of Darwin's favourite orchids (Catasetinae) and Swan orchids (Cycnoches Lindl.)

The Orchidaceae are one of the most species rich and widespread lineages among angiosperms. They have evolved numerous remarkable vegetative and reproductive traits that have allowed them to successfully adapt and diversify into a wide array of environments. More importantly, they have developed several intricate symbiotic relationships with different kinds of organisms (e.g. animals, fungi) that for centuries have attracted the attention of botanists, biologists, amateurs and naturalists. Nevertheless, despite the extensive research done so far on orchid biology and phylogenetics, very little is known about the biotic and environmental variables as well as the evolution of several key traits that seem to be linked with the successful diversification of this lineage. This dissertation is focused on three puzzling aspects of plant evolutionary biology, specifically the phylogenetic incongruence between nuclear and plastid genomes, the evolution of sexual systems, and lineage migration and isolation through time. To address these topics, I chose as a group of study the sub tribe Catasetinae, an orchid lineage including ca. 350 species restricted to the Neotropical region. They show a remarkable set of sexual systems, namely protandry and Environmental Sex Determination (ESD), that were never studied before in a phylogenetic context. My dissertation includes as well a minor part on taxonomic and floristic work devoted to other representative orchid lineages of the Neotropical flora (i.e. Epidendrum and Lepanthes). Based on vegetal material collected during field trips, my taxonomic research resulted in the description of several new species and new chorological reports contributing to the Colombian and Costa Rican Floras. Using a set of nuclear and chloroplast loci obtained from material cultivated at the Botanic Garden Munich and collected during field work in several Latin American countries, I produced a well-supported and insofar the most representatively sampled phylogeny of Catasetinae. While gathering vegetal material, I encountered several complications such as extreme scarcity of individuals and worrisome, extensive bureaucratic administrative processes to obtain collection and research permits that finally undermined my taxon sampling. By studying in detail the Catasetinae internal phylogenetic relationships independently derived from nuclear and plastid loci, I came across several well supported conflicting phylogenetic positions. Most of the traditional phylogenetic methods developed to address these conflicts aim at the inference of a species tree only. In chapter 5, I explored the utility of co-phylogenetic tools (i.e. PACo and ParaFit) to quantify the conflicts between nuclear and plastid genomes. These tools have been largely employed in host-parasite/endosymbiont studies, hence they have the power to assess the contribution of single Operational Terminal Units (OTUs) to the phylogenetic pattern observed. As a result, using the Catasetinae chloroplast and nuclear datasets and extensive simulation approaches, I demonstrate that PACo successfully detects conflicting OTUs and its performance is overall better than ParaFit. In addition, my research provided strong evidence towards the bias of input data type (i.e. phylograms and cladograms) on distance-based co-phylogenetic methods. A pipeline to execute PACo and ParaFit tools in the software R to detect conflicting sequences in either small or big datasets was designed After inferring a strongly supported phylogeny, and by carrying in-situ and ex-situ observations plus searches of specialized literature on reproductive biology, I investigated the evolution of sexual systems of Catasetinae. I relied on Ancestral State Reconstruction (ASR) approaches and Bayesian statistical frameworks (chapter 6). As a result, ASR revealed three independent gains of ESD, once in the Last Common Ancestor (LCA) of Catasetum, Cycnoches and part of Mormodes, respectively, always derived from a protandrous ancestors. In contrast, protandry appears to have evolved only once, at the LCA of Catasetum, Clowesia, Cycnoches, Dressleria and Mormodes. The last chapter of this dissertation deals with the impact of the Andean uplift, the most important orographic event in South America, on evolution of epiphytic lowland Neotropical lineages. I used as a group of study Cycnoches (a member of the Catasetinae), which includes ca. 34 species and is distributed in Neotropical lowland wet forests. To address this goal, I produced the most completely sampled phylogeny of Cycnoches, and relied on Bayesian dating and Ancestral Area Estimation (AAE) approaches. The LCA of Cycnoches lived ca. 6 million years ago (MYA) in the Amazonian region. From this area, it expanded towards Central America and Choco in multiple migrations well after main Andean mountain building episodes. In addition, stochastic character mapping showed that within-region speciation (i.e. speciation in sympatric lineages) was a key process linked to diversification and range distribution evolution in Cycnoches

Numerical Construction of initial data sets for inhomogeneous cosmological space-times with spatial topology of T3\mathbb{T}^3

In this work, we numerically construct initial data sets for cosmological space-times with a spatial topology of $\mathbb{T}^3$, which are generally inhomogeneous. To do so, we implement a pseudo-spectral approach based on the discrete Fourier transform for numerically solving Einstein's constraint equations in an algebraic-hyperbolic form. We explore the advantages and disadvantages of this method by comparing the numerical solutions with known analytical initial data sets. Furthermore, we obtain new families of initial data sets numerically for different configurations of the boundary values of certain geometric variables

CO2 strong chemisorption as an estimate of coal char gasification reactivity

ABSTRACT: In this article, coal char gasification reactivity was correlated with the strong chemisorption of CO2 at 3008C. Chars of as-received, demineralized, K and Fe loaded coals were prepared at 8008C, under high purity nitrogen. The CO2 chemisorption method described in this article allows differentiation between two types of chemisorption that takes place at low temperatures: strong CO2 chemisorption (irreversible) which is related to the presence of the active inorganic components of the char, and weak CO2 chemisorption (reversible) which is because of the organic matter of the char. The char doped with K showed the highest CO2 strong chemisorption and at the same time the highest reactivity in the CO2 gasification, while the char loaded with Fe had the highest amount of weak chemisorption. It was found that total chemisorption (weak 1 strong) at 3008C depends on the CO2 pressure of the analysis. The reactivity of the CO2 gasification of the char was normalized using the value of the amount of CO2 strongly chemisorbed at 3008C. q 1999 Elsevier Science Ltd. All rights reserved

La demostración en geometría: una mirada en la educación primaria

En esta investigación presentamos un estudio realizado durante el año 2012 en un curso de grado cuarto de primaria de una institución privada de la ciudad de Bogotá. El propósito es analizar la manera en que los niños se involucran en distintas acciones de introducción a la actividad demostrativa, cuando trabajan en un ambiente de resolución de problemas, haciendo uso de un programa de geometría dinámica. Los problemas propuestos a los estudiantes promueven la construcción de figuras geométricas, la exploración en busca de regularidades y la justificación de algunas propiedades con base en otras. En la investigación se puso en marcha un experimento de enseñanza a partir del diseño de una secuencia de actividades que consta de siete problemas con temas básicos de la geometría escolar. Se tomaron registros de la actividad matemática desarrollada por los estudiantes en los dos últimos problemas del experimento y se analizaron los diálogos de los estudiantes y la actividad desarrollada en el último problema, a la luz del marco teórico que propusimos para este trabajo de grado con el propósito de describir el inicio a la actividad demostrativa

GeoGebraPrim como instrumento para descubrir y justificar propiedades geométricas en cuarto de primaria

Se describe una experiencia de aula en la que el programa GeoGebraPrim desempeña un papel en la introducción a la actividad demostrativa de estudiantes de grado cuarto de primaria, quienes son invitados a construir figuras geométricas, explorarlas en busca de regularidades y justificar algunas propiedades con base en otras. La experiencia se fundamenta en el constructo “actividad demostrativa” del grupo de investigación Aprendizaje y Enseñanza de la Geometría de la Universidad Pedagógica Nacional y en la definición de demostración propuesta por Stylianides (2007)