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Search Results: 1 - 10 of 193 matches for " Vaca-Vaca "
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Detección, identificación y localización geográfica de Begomovirus que afectan al tomate en Colombia
Vaca-Vaca,Juan Carlos; Betancurt-Pérez,Jhon Fredy; López-López,Karina;
Revista Colombiana de Biotecnología , 2011,
Abstract: the begomoviruses (family geminiviridae) have recently emerged as a serious pathogens of agronomic and horticultural crops in subtropical and tropical regions of world. these viruses are transmitted by the whitefly (bemisia tabaci) that recently has got a significant increase in its populations and also has been associated with the appearance of geminivirus typical symptoms in tomato crops around colombia. tomato samples with typical begomovirus symptoms were collected in five different departments, comprising the mayor tomato growing areas of the country. begomovirus were detected by polymerase chain reaction (pcr) or dot blot hybridization in all tomato samples collected in whole tomato growing areas of the country. with exception for valle del cauca, this is the first report of tomato-infecting begomovirus in antioquia, santander, boyacá and cundinamarca departments. also this is the first report of tomato-infecting begomovirus crops located above 1500 masl in colombia.
Distribución y diversidad genética de Begomovirus que infectan tomate (Solanum lycopersicum L) en Colombia
Vaca-Vaca,Juan Carlos; Betancur-Pérez,Jhon Fredy; López-López,Karina;
Revista Colombiana de Biotecnología , 2012,
Abstract: diseased caused by begomoviruses (family geminiviridae) constitute a serious constraint to tomato production in colombia. however characterization of these new viruses had not been carried out so far. here we report a large scale survey on the distribution and genetic diversity of tomato infecting geminiviruses which are affecting mayor growing area of this crop in the country. viruses were detected by pcr using universal primers for members of genus begomovirus. the rflp analysis of pcr-amplified fragments showed individual and mixed infections of several geminiviruses in many of the samples. pcr-amplified fragments were cloned and sequenced. based on sequence comparations and phylogenetic analysis, the colombian geminivirus isolates were new world bipartite geminiviruses showing close relationship with pymv and tovev. by means of bioinformatic analysis of cis-acting elements (iterons) involved in dna replication of rep gene of colombian geminivirus isolates was possible to postulate possible pseudorecombinación events that could occur between them but also confirm the occurrence of mixed infections.
Detección, identificación y localización geográfica de Begomovirus que afectan al tomate en Colombia
Vaca-Vaca Juan Carlos,Betancurt-Pérez Jhon Fredy,López-López Karina
Revista Colombiana de Biotecnología , 2011,
Abstract: Detection, identification and geographical localization of tomato-infecting Begomovirus in Colombia Título corto: Begomovirus que afectan tomate en Colombia Resumen En la actualidad, los Begomovirus (Familia Geminiviridae) se han convertido en la mayor amenaza para los cultivos de interés agrícola ubicados en las zonas tropicales y templadas del planeta. Estos virus son transmitidos por la mosca blanca Bemisia tabaci, la cual en los últimos a os en Colombia ha tenido un aumento significativo en sus poblaciones y se ha asociado con la aparición de síntomas virales en cultivos de tomate. Muestras de tomate con síntomas virales típicos fueron recolectadas en las cinco principales zonas productoras de esta solanácea en el país. Los Begomovirus fueron detectados por medio de la técnica de hibridación de ácidos nucleicos tipo Dot blot así como por medio de la reacción en cadena de la polimerasa (PCR) en todas las muestras colectadas. Con la excepción de un reporte previo en el Valle del Cauca, este es el primer reporte de Begomovirus afectando cultivos de tomate en los departamentos de Antioquia, Santander, Boyacá y Cundinamarca. Asimismo, es la primera vez que se informa sobre Begomovirus que afectan cultivos de tomate localizados por encima de 1500 msnm en Colombia. Palabras clave: Begomovirus, Bemisia tabaci, tomate, Dot blot, PCR. Abstract The begomoviruses (Family Geminiviridae) have recently emerged as Key words: Begomovirus, Bemisia tabaci, tomato, Dot blot, PCR. samples with typical Begomovirus symptoms were collected in five different departments, comprising the mayor tomato growing areas of the country. Begomovirus were detected by Polymerase Chain Reaction (PCR) or Dot Blot Hybridization in all tomato samples collected in whole tomato growing areas of the country. With exception for Valle del Cauca, this is the first report of tomato-infecting Begomovirus in Antioquia, Santander, Boyacá and Cundinamarca departments. Also this is the first report of tomato-infecting Begomovirus crops located above 1500 masl in Colombia.
Distribución y diversidad genética de Begomovirus que infectan tomate (Solanum lycopersicum L) en Colombia
Vaca-Vaca Juan Carlos,Betancur-Pérez Jhon Fredy,López-López Karina
Revista Colombiana de Biotecnología , 2012,
Abstract: Título en ingles: Distribution and genetic diversity of tomato –infecting Begomovirus in Colombia Resumen: Las enfermedades causadas por los begomovirus, (Familia Geminiviridae) constituyen una serie limitante para la producción del tomate en Colombia. Sin embargo, la caracterización de estos virus no ha sido realizada al momento. Aquí presentamos los resultados de un muestreo a nivel nacional que buscaba conocer la distribución y diversidad genética de los geminivirus que están afectando el cultivo de tomate en Colombia. Los virus fueron detectados mediante PCR, empleando primer universales específicos para el género Begomovirus. Los fragmentos amplificados por PCR fueron sometidos a un análisis tipo RFLP cuyos resultados evidenciaron presencia de infecciones mixtas e individuales de geminivirus en la mayoría de las muestras recolectadas en campo. Los fragmentos amplificados por PCR fueron clonados y secuenciados. El análisis de secuencia y filogenético mostró que los aislados begomovirales colombianos eran gemininivirus bipartitas típicos del Hemisferio Occidental y que algunos eran variantes de PYMV y otros de ToTEV. Mediante el análisis de los elementos cis-regulatorios (iterones) presentes en el promotor del gen de la proteína asociada a replicación (Rep) de los begomovirus aislados es posible postular eventos de pseudorecombinación que podrían suceder entre ellos durante la ocurrencia de infecciones mixtas en tomate. Palabras claves: Geminivirus; Solanum licopersicum; PCR-RFLP; infecciones mixtas. Abstract: Diseased caused by begomoviruses (Family Geminiviridae) constitute a serious constraint to tomato production in Colombia. However characterization of these new viruses had not been carried out so far. Here we report a large scale survey on the distribution and genetic diversity of tomato infecting geminiviruses which are affecting mayor growing area of this crop in the country. Viruses were detected by PCR using universal primers for members of genus Begomovirus. The RFLP analysis of PCR-amplified fragments showed individual and mixed infections of several geminiviruses in many of the samples. PCR-amplified fragments were cloned and sequenced. Based on sequence comparations and phylogenetic analysis, the Colombian geminivirus isolates were new world bipartite geminiviruses showing close relationship with PYMV and ToVEV. By means of bioinformatic analysis of cis-acting elements (iterons) involved in DNA replication of rep gene of Colombian geminivirus isolates was possible to postulate possible pseudorecombinación events that could occur betwee
Búsqueda de genes de resistencia al pasador del fruto en poblaciones segregantes de tomate
Rodríguez Mora Diana Milena,Betancur-Pérez Jhon Fredy,Vallejo Cabrera Franco Alirio,Vaca-Vaca Juan Carlos
Acta Agronómica , 2010,
Abstract: Las estrategias de mejoramiento genético para encontrar resistencia al pasador del fruto, Neoleucinodes elegantalis, en tomate, Solanum lycopersicum L. se han basado en métodos tradicionales de introgresión genética por medio de retrocruzamiento. Sin embargo este proceso es largo y dispendioso. Debido a esta problemática, se utilizó la técnica molecular cDNA-AFLP para identificar genes involucrados en la resistencia a esta plaga en poblaciones segregantes de tomate, con el fin de identificar marcadores moleculares que puedan ser utilizados en futuros programas de fitomejoramiento. Los materiales de tomate evaluados fueron Unapal-Maravilla (susceptible), S. habrochaites var. glabratum, accesión PI 134418 (resistente) y tres retrocruzamientos obtenidos del cruzamiento interespecífico entre ambas especies. De estos materiales vegetales se extrajo el RNA total y se sintetizó el cDNA, el cual se utilizó como material de inicio de la técnica cDNA-AFLP. A partir del preamplificado de cDNA se evaluaron diferentes combinaciones de primers: +1+1, +3+3 y sus derivados. La combinación que presentó mejores amplificados fue la +1+1, para un total de 37 bandas polimórficas. De estas bandas, 9 fragmentos tipo EST (Expressed Sequence Target) fueron recuperados, siendo candidatos a explicar la resistencia al pasador del fruto en tomate.
Búsqueda de genes de resistencia al pasador del fruto en poblaciones segregantes de tomate
Rodríguez Mora,Diana Milena; Betancur-Pérez,Jhon Fredy; Vallejo Cabrera,Franco Alirio; Vaca-Vaca,Juan Carlos; López-López,Karina;
Acta Agronómica , 2010,
Abstract: breeding strategies for resistance to fruit borer neoleucinodes elegantalis in tomato solanum lycopersicum k l. have relied on traditional methods through genetic introgression by backcrossing. however, this process is slow and expensive. the cdna-aflp molecular technique was used to identify genes involved on fruit borer resistance in tomato segregating populations, the evaluated materials of tomato were: unapal maravilla (susceptible to fruit borer) , s. habrochaites var. glabratum, acc. pi 134418 (resistant to fruit borer), and three interspecific backcross produced by crossbreeding between those two species. from these plant materials, total rna was extracted and cdna-aflp technique was implemented. from the preamplified cdna, different combinations of primers: +1+1, +3+3 and their derivates were evaluated. the combination that showed better amplified was +1+1 for a total of 37 polymorphic bands and 9 fragments type expressed sequence target was isolated, which could explain the resistance of tomato to fruit borer.
A Search for Lambda sub-b in pi^- - A Collisions at 515 GeV/c
F. Vaca
Physics , 1995,
Abstract: An extensive analysis was performed on 8.0 pb-1 of dimuon data produced in pi- - A collisions at 515 GeV/c to search for Lambda_b events in the decay channel Lambda_b --> J/psi Lambda^0, with J/psi --> mu^+ mu^- and Lambda^0 --> p pi^- (and for the conjugate reactions). The data was collected by the Fermilab fixed target experiments E672 and E706. Several cuts were applied to the Lambda^0 (and anti-Lambda^0) to make a clean Lambda^0 (and anti-Lambda^0) data sample. Among the cuts there was a K^0_s mass cut, in which if the Lambda^0 --> p pi^- (or conjugate reaction) had the mass of the K^0_s under the hypothesis of both tracks being pi^+ pi^-, the Lambda^0 (or anti-Lambda^0) candidates were rejected. The results show 2 events in the Lambda_b mass region. Using the E672/E706 measurement of the bb_bar cross-section, and considering the 2 Lambda_b event candidates as signal with zero background, an upper limit to F(Lambda_b) * Br(Lambda_b --> J/psi Lambda^0) was found to be less than 6.2x10^-2 at 90 % C. L. An upper limit was also calculate without using the K^0_s mass cut for the Lambda^0 s (and anti-Lambda^0 s), and again, requiring that the J/psi s originate from secondary vertices, giving that F(Lambda_b) * Br(Lambda_b --> J/psi Lambda^0) < 3.1x10^-2 at 90 % C. L. and F(Lambda_b) * Br(Lambda_b --> J/psi Lambda^0) < 3.2x10$^-2 at 90 % C.L., respectively.
CONSTRUCCIóN DE SIGNIFICADOS FRENTE A LOS CONTENIDOS VIOLENTOS DE LOS VIDEOJUEGOS EN NI?OS DE 11 A 14 A?OS
VACA VACA,PATRICIA; ROMERO SERRANO,DIEGO;
Acta Colombiana de Psicología , 2007,
Abstract: this project was part of the research line entitled "violence and the media" developed by the faculty of psychology of the universidad de la sabana. , the aim of the study was to enquire about the meaning that children give to violent contents of videogames. participants were four children between the ages of 11 and 14, who attended public schools in the village of chía (colombia). the research had a qualitative approach and used a descriptive-explanatory method, adopting the single-case study strategy. based on the participants? narratives an analysis was made of the meanings that children gave to topics such as recognition of violence, conflict perception, conflict resolution, gender identity, relationship between family and videogames and the power of videogames. data were collected through the use of focus groups and analyzed according to strauss and corbin?s theory (2002). results show that there is a relationship between the violent contents of videogames and the meaning given to them by the participants in the focus group. this underlines the influence that videogames have on the development of values and beliefs in children.
CONSTRUCTION OF MEANINGS RELATED TO VIOLENT CONTENTS OF VIDEO GAMES IN CHILDREN AGED 11 TO 14
Vaca Vaca, Patricia,Romero Serrano, Diego
Acta Colombiana de Psicología , 2007,
Abstract: This project was part of the research line entitled "Violence and the Media" developed by the Faculty of Psychology of the Universidad de la Sabana. , The aim of the study was to enquire about the meaning that children give to violent contents of videogames. Participants were four children between the ages of 11 and 14, who attended public schools in the village of Chía (Colombia). The research had a qualitative approach and used a descriptive-explanatory method, adopting the single-case study strategy. Based on the participants' narratives an analysis was made of the meanings that children gave to topics such as recognition of violence, conflict perception, conflict resolution, gender identity, relationship between family and videogames and the power of videogames. Data were collected through the use of Focus Groups and analyzed according to Strauss and Corbin's theory (2002). Results show that there is a relationship between the violent contents of videogames and the meaning given to them by the participants in the focus group. This underlines the influence that videogames have on the development of values and beliefs in children
Desarrollo regional en la Argentina: la centenaria vigencia de un patrón de asimetría territorial
Cao,Horacio; Vaca,Josefina;
EURE (Santiago) , 2006, DOI: 10.4067/S0250-71612006000100006
Abstract: republic or argentina is characterized by a sharp inequality in the development level of it regions. this paper reviews the way in which that regional asymmetry is originated, and how it was reproduced along the different stages of argentinean history. a series of hypothesis regarding it main features in the present stage is developed
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