Functional and structural genomics of amino acid metabolism in Streptomyces coelicolor

An investigation of amino acid metabolism in Streptomyces coelicolor, including the anabolism of tryptophan, histidine, the branched-chain amino acids and proline, as well as the catabolism of the latter, is reported. The experiments reported herein were conceptually conceived within a functional genomics framework. For this purpose the complete genome sequence of S. coelicolor was systematically exploited. Moreover, the current knowledge on the physiology of Streptomyces was taken onboard, as well as the prevailing and emerging notions on the evolution of proteins and metabolic pathways. Some of the results obtained using S. coelicolor as a model organism were expanded to other actinomycetes, such as Mycobacterium tuberculosis. This was aided by a comparative genomics analysis of the actinomycetes whose genomes have been sequenced. The theoretical principles that give support to this thesis are introduced in Chapter 1. This study was greatly facilitated by the development of a novel PCRtargeting mutagenesis method of which details can be found in Chapter VII. The discovery of a common isomerase for tryptophan and histidine biosynthesis is reported in Chapter II. This discovery arose from efforts aimed at reconstructing the tryptophan biosynthetic pathway of S. coelicolor, since the genome sequence project of this organism failed to identifiy a trpF gene coding for the enzyme phosphoribosyl anthranilate isomerase. The solution of this functional genomics discrepancy led to the discovery of a putative (~a)8-barrel enzyme, termed PriA, whose preliminary functional and structural characterisation is reported in Chapter III. The evolutionary implications of the discovery of PriA are discussed within Chapters III and N. A comparative genomics analysis of actinomycetes centred on the priA gene is presented in the latter Chapter, supporting the notion that this novel protein is spread across the high (0 + C) content Gram-positive organisms. Indeed, it was predicted that a priA orthologue accounts for the lack of a trpF gene from the genome of M tuberculosis, a hypothesis that proved to be correct. Finally, evidence to support the notion that the histidine and tryptophan biosynthetic pathways co-evolved is presented. In contrast to the isomerisation catalysed by PriA, in which an enzyme is shared by two amino acid biosynthetic pathways, several paralogous enzymes with the potential to account for the first step of tryptophan biosynthesis from chorismate were found on the genome of S. coelicolor. These chorismate-utilising enzymes are investigated in Chapter V. Mutational analysis of some of this paralogues is reported and it is anticipated that the analysis and results reported therein will serve to direct future experiments aimed at identifying the trpE paralogue encoding the enzyme anthranilate synthase. Chapter VI reports on the identification of the proC gene involved in the last step of proline biosynthesis in S. coelicolor. The pyrroline-5-carboxylate reductase activity of the enzyme encoded by the putative proC gene was extensively characterised, with particular emphasis on the interaction between primary and secondary metabolism. Furthermore, mutational analysis of proC suggested that paralogues of this gene are present on the genome of this organism, since its deletion did not lead to an auxotrophic phenotype. Investigation of this observation showed that two paralogous enzymes encoded by i1vC-like genes, involved in biosynthesis of the branched-chain amino acids, are capable of compensating for the lack of proC. This is the first example of a physiological link between the biosynthesis of proline and the branched-chain amino acids. To sum up, the results reported in this thesis represent an advancement towards understanding the physiology of S. coelicolor as a model actinomycete, within a functional and structural genomics framework. They also offer evidence on the evolutionary principles that lead to the appearance of novel proteins and metabolic pathways in bacteria.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Incidencia de los Robos y Hurtos en el Sistema de Seguros Agrarios Español.

Este trabajo se estudia la viabilidad técnica de incorporar al actual Sistema de Seguros Agrarios Español la cobertura de los robos y hurtos en el medio rural, calculando la prima pura base (Ppb) para todas las producciones agrícolas, ganaderas y medios de producción asegurables dentro del sistema de los Seguros Agrarios Combinados. Los resultados indican que los robos se producen con una mayor influencia sobre los elementos de los riegos por aspersión y de los invernaderos, y la Ppb en consecuencia es la más alta de todos los bienes asegurables. Les siguen en importancia las explotaciones de ganado ovino-caprino y, en cuanto a las producciones agrícolas, destaca el olivar

Sum Insured Determination for Cereal, Citrus and Vineyards in the Spanish Agricultural Insurance System.

In general, insurance is a form of risk management used to hedge against a contingent loss. The conventional definition is the equitable transfer of a risk of loss from one entity to another in exchange for a premium or a guaranteed and quantifiable small loss to prevent a large and possibly devastating loss being agricultural insurance a special line of property insurance. Agriculture insurance, as actually are designed in the Spanish scenario, were established in 1978. At the macroeconomic insurance studies scale, it is necessary to know a basic element for the insurance actuarial components: sum insured. When a new risk assessment has to be evaluated in the insurance framework, it is essential to determinate venture capital in the total Spanish agriculture. In this study, three different crops (cereal, citrus and vineyards) cases are showed to determinate sum insured as they are representative of the cases found in the Spanish agriculture. Crop sum insured is calculated by the product of crop surface, unit surface production and crop price insured. In the cereal case, winter as spring cereal sowing, represents the highest Spanish crop surface, above to 6 millions of hectares (ha). Meanwhile, the four citrus species (oranges, mandarins, lemons and grapefruits) occupied an extension just over 275.000 ha. On the other hand, vineyard target to wine process shows almost one million of ha in Spain

Functional and structural genomics of amino acid metabolism in Streptomyces coelicolor

An investigation of amino acid metabolism in Streptomyces coelicolor, including the anabolism of tryptophan, histidine, the branched-chain amino acids and proline, as well as the catabolism of the latter, is reported. The experiments reported herein were conceptually conceived within a functional genomics framework. For this purpose the complete genome sequence of S. coelicolor was systematically exploited. Moreover, the current knowledge on the physiology of Streptomyces was taken onboard, as well as the prevailing and emerging notions on the evolution of proteins and metabolic pathways. Some of the results obtained using S. coelicolor as a model organism were expanded to other actinomycetes, such as Mycobacterium tuberculosis. This was aided by a comparative genomics analysis of the actinomycetes whose genomes have been sequenced. The theoretical principles that give support to this thesis are introduced in Chapter 1. This study was greatly facilitated by the development of a novel PCRtargeting mutagenesis method of which details can be found in Chapter VII. The discovery of a common isomerase for tryptophan and histidine biosynthesis is reported in Chapter II. This discovery arose from efforts aimed at reconstructing the tryptophan biosynthetic pathway of S. coelicolor, since the genome sequence project of this organism failed to identifiy a trpF gene coding for the enzyme phosphoribosyl anthranilate isomerase. The solution of this functional genomics discrepancy led to the discovery of a putative (~a)8-barrel enzyme, termed PriA, whose preliminary functional and structural characterisation is reported in Chapter III. The evolutionary implications of the discovery of PriA are discussed within Chapters III and N. A comparative genomics analysis of actinomycetes centred on the priA gene is presented in the latter Chapter, supporting the notion that this novel protein is spread across the high (0 + C) content Gram-positive organisms. Indeed, it was predicted that a priA orthologue accounts for the lack of a trpF gene from the genome of M tuberculosis, a hypothesis that proved to be correct. Finally, evidence to support the notion that the histidine and tryptophan biosynthetic pathways co-evolved is presented. In contrast to the isomerisation catalysed by PriA, in which an enzyme is shared by two amino acid biosynthetic pathways, several paralogous enzymes with the potential to account for the first step of tryptophan biosynthesis from chorismate were found on the genome of S. coelicolor. These chorismate-utilising enzymes are investigated in Chapter V. Mutational analysis of some of this paralogues is reported and it is anticipated that the analysis and results reported therein will serve to direct future experiments aimed at identifying the trpE paralogue encoding the enzyme anthranilate synthase. Chapter VI reports on the identification of the proC gene involved in the last step of proline biosynthesis in S. coelicolor. The pyrroline-5-carboxylate reductase activity of the enzyme encoded by the putative proC gene was extensively characterised, with particular emphasis on the interaction between primary and secondary metabolism. Furthermore, mutational analysis of proC suggested that paralogues of this gene are present on the genome of this organism, since its deletion did not lead to an auxotrophic phenotype. Investigation of this observation showed that two paralogous enzymes encoded by i1vC-like genes, involved in biosynthesis of the branched-chain amino acids, are capable of compensating for the lack of proC. This is the first example of a physiological link between the biosynthesis of proline and the branched-chain amino acids. To sum up, the results reported in this thesis represent an advancement towards understanding the physiology of S. coelicolor as a model actinomycete, within a functional and structural genomics framework. They also offer evidence on the evolutionary principles that lead to the appearance of novel proteins and metabolic pathways in bacteria

Fuentes de estrés en el profesor de matemáticas: estudio realizado en la cuidad de Badajoz

El objetivo general de nuestra investigación consiste en detectar las fuentes de estrés en el profesor de matemáticas de secundaria, a partir de una escala de elaboración propia. La construcción de este instrumento se inició con una revisión bibliográfica, a partir de la cual creamos una escala que fue aplicada a un grupo reducido de profesores de matemáticas de secundaria, realizándose posteriormente un grupo de discusión. A partir de las conclusiones que obtuvimos, creamos un instrumento que fue aplicado a 60 docentes de matemáticas de secundaria de centros públicos, privados y concertados de la ciudad de Badajoz (Extremadura). Además de nuestra escala, se aplicaron otros instrumentos cuya finalidad es medir el desgaste profesional y la salud mental de estos docentes de estrés que afectan a estos docentes.The overall objective of our research consists of detecting sources of stress in the Professor of mathematics at secondary school, from a homemade scale. The construction of this instrument began with a literature review, from which we create a scale that was applied to a small group of professors of mathematics high school, subsequently making a discussion group. Based on the conclusions which we obtained, we create an instrument that was applied to 60 teachers of mathematics secondary public, private and reached the city of Badajoz (Extremadura) centres. In addition to our scale, other instruments whose aim is to measure professional wear and the mental health of these teachers were applied. This work shows the most relevant results obtained in relation to the sources of stress that affect these teachers.peerReviewe

Aspectos conceptuales y empíricos de la financiación de nuevas empresas en Colombia

Este artículo presenta los resultados de una investigación empírica sobre la utilización de diferentes fuentes de financiación por parte de empresas nuevas en los primeros años de vida. El principal soporte conceptual del estudio es el paradigma del ciclo de crecimiento financiero desarrollado por Berger y Udell (1998), el cual explica satisfactoriamente los hallazgos encontrados en el componente empírico del estudio aquí presentado, que se basa en una encuesta realizada a 130 empresarios de la Ciudad de Cali (Colombia). Los entrevistados reportaron de manera mayoritaria el uso de recursos propios y de familiares y amigos y la retención de utilidades en los primeros años de vida de una empresa. Le sigue en importancia a estas fuentes, la financiación provista por establecimientos de crédito; llama la atención la importancia relativa del leasing. Las recomendaciones más importantes incluyen: fortalecer las fuentes de capital semilla, darle mayor peso en los cursos de finanzas de nivel universitario al estudio de los problemas de las empresas nuevas y MIPYMES, adelantar una reforma financiera que facilite la emisión de acciones y mejorar la cantidad y calidad de información pública disponible sobre la financiación de las empresas objeto de este estudi

Impacto financiero a causa de la segregación Guachené – Caloto, departamento del Cauca.

El presente trabajo de investigación se realiza con el fin de conocer el impacto tributario y presupuestal a causa de la segregación Guachené Caloto, en el Departamento del Cauca. Mediante Decreto del 0653 del 19 de enero de 2006 el Gobernador del Cauca crea el municipio de Guachené desagregando del municipio de Caloto las siguientes veredas: San Jacinto, la Dominga, Barragán, Cabito, Mingo; Caponera, Pueblo Nuevo (Obando), La Sofía, Guabal, Sabanetas, Cabaña, Cabañita, San Antonio, San José, Juan Perdido, Campo alegre, Llano de Taula, Llano de Taula Alto, Campo Llanito, Silencio y Guachené. Con la separación de Guachené las finanzas de Caloto se vieron afectadas, debido a que los recursos provenientes de las transferencias nacionales fueron disminuidas notablemente, igualmente ocurrió con los recursos propios debido a que la mayor parte del sector industrial que le generaba importantes recaudos por el impuesto de industria comercio hoy se encuentran localizados en el Municipio de Guachené, así mismo disminuyó el recaudo del impuesto predial

The affective domain in teaching and learning mathematics: A review of local research

En este artículo hace111os un resunzen de las investigaciones que el Grupo CRESPE (Estrés, Salud, Psicopatología y Bienestar Emocional) y el Grupo de DEPROFE (Desanvllo Profesional de los Profesores de Ciencias y Matenzáticas), como grupos de investigación reconocidos por la Junta de Extrenzadura y por la Universidad de Extrenwdura, han realizado sobre el donzinio afectivo (creencias, actitudes y enzociones) y su influencia en laenseñanz.alaprendizaje de las nzatemáticas, tanto en secundaria conzo en la formación inicial de n1aestros, incluyendo algunos resultados generales de los niisnzos que han dado origen a la línea de investigación que en estos 1non1entos están llevando a caboWe present a synthesis oj the research that the Groups GRESPE (Stress, Health, Psychopathology, and Wellbeing) and DEPROFE (Professional Development of Mathen1atics and Science Teachers), research groups recognized by the Junta de Extren1adura and the University oj Extren1adura, have been conducting 011 the affective don1ain (beliejs, altitudes, and en1otions) and its injluence on n1athen1atics teaching and learning, in secondary education and in initial teacher education, including sorne general results that have given rise to the research fine which is currently being j'ollowedpeerReviewe

Meta-analytic study of implant survival following sinus augmentation

Objectives: To evaluate graft types used for maxillary sinus augmentation and review success rates of dental implants inserted in these areas, analyzing the graft materials used, implant surface types and the moment of implant placement. Study Design: A meta-analytic study reviewing articles on sinus augmentation published during the last ten years. Results: 3,975 implants placed in sinus augmentations (with bony windows) were registered, of which 3,749 implants survived, a survival rate of 94.3%. Conclusions: When performing sinus augmentation, bone substitute materials are just as effective as autologous bone, whether used alone or in combination with autologous bone. Implant surface treatments can have an important effect on implant survival and it would appear that roughened surfaces are the best option. When implants are inserted simultaneously to grafting, a higher failure rate can be expected. © Medicina Oral S. L

EL PROCESO DE CONSTRUCCIÓN TERRITORIAL DE LA ORINOQUIA COLOMBIANA EN EL SIGLO XIX

TRANSFORMACIONES TERRITORIALES DURANTE EL SIGLO XIX Las guerras de Independencia significaron una pérdida enorme para la Orinoquia, ya que se destruyeron tres siglos de formación territorial que se habían logrado por medió de una extrema crueldad y sacrificio. Durante el período colonial el Estado español y las Misiones jesuíticas lograron crear pueblos de tipo europeizante, abrir haciendas ganaderas, establecer la navegación en numerosos ríos y trazar caminos para el comercio. Una enorme riqueza social estructurada con el sudor y la destrucción cultural de las comunidades indígenas de la región que, mal que bien, ya hacían parte de esa nueva realidad. La guerra significó la desocupación de pueblos enteros, de los cuales la mayoría de sus habitantes sucumbieron en la lidia, más por hambre y enfermedades que por las balas. Los indígenas que no perecieron en la lucha se retiraron a las montañas en busca del sustento y para huir de las numerosas enfermedades que se desataron por las hambrunas y por la falta de salud pública. Las haciendas fueron desocupadas, porque los combatientes tomaron las reses y los caballos como impuesto de guerra, llevándolas a la ruina. Sin gente, sin pueblos y sin haciendas se acabó el comercio y los caminos y la navegación perdieron su objeto