1,721,114 research outputs found
Selección y mapeo de marcadores moleculares microsatélites (SSR) a partir de un cruce interespecífico de arroz entre oryza sativa l. y oryza rufipogon griff
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Construcción, y evaluación de una librería preliminar de lineas de introgresión interespecificas de arroz (O. sativa x O. glaberrima) mediante marcadores moleculares microsatélitales
No full textilIncluye referencias bibliográficasExiste copia en microfichaMicrobiólogoPregrad
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Introgresion de QTLs de resistencia al virus de la hoja blanca en materiales élites de arroz en Colombia
Get PDFLa resistencia al VHBA es una caracter difícil, laborioso y costoso de evaluar. El proceso de selección para dicha resistencia exige el mantenimiento de colonias virulentas del vector Tagosodes orizicolus Muir, lo que en conjunto, impide lograr una eficiencia satisfactoria de la selección para ese carácter. Previa identificación de marcadores moleculares tipo microsatélite con efecto importante sobre la resistencia a VHBA (Calvert et al., 2006) en dos poblaciones F2/F3 desarrolladas en el CIAT a partir de los cruces entre la línea altamente susceptible WC366 y las variedades resistentes a VHBA y sogata: Fedearroz 2000 (Fd2000) y Fedearroz 50 (Fd50), respectivamente, el objetivo de esta investigación fue realizar la introgresión de los QTLs que controlan la resistencia a VHBA en dos materiales elites susceptibles, lo cual permitió alcanzar un nivel aceptable de resistencia en cuatro generaciones, utilizando principalmente la información genética. En el presente trabajo, los marcadores moleculares se utilizaron para seleccionar la resistencia al VHBA del progenitor donador Fd2000 y el fondo genético de las poblaciones de retrocruzamiento. Con base en la calificación al VHBA, el nivel de polimorfismo y otras características agronómicas, se seleccionaron dos líneas elite CT18685-10-3-1-2-2-M y Fd174 como candidatas para la introgresión de QTLs. Plantas F1 heterocigotas obtenidas de los cruzamientos entre las dos líneas élites y Fd2000 fueron retrocruzadas hacia las líneas elite recurrentes. En la generación BC1F1, los individuos que poseían los alelos de resistencia de los QTLs se retrocruzaron con el fin de obtener familias BC2F1 y BC3F1, generación a partir de la cual se autofecundó hasta la obtención de semillas BC3F2. La detección de las introgresiones provenientes del progenitor resistente Fd2000 en las dos líneas élites permitió seleccionar 177 plantas resistentes al VHBA. Este método de retrocruzamiento asistido por marcadores (RAM) aceleró y facilitó la identificación y selección de las líneas élites con resistencia al VHBA. aqui termina el resumen en español. / Abstract. Abstract starts here Resistance to RHBV is a difficult, laborious and expensive trait to evaluate. The selection process for this resistance requires the maintenance of virulent colonies Tagosodes orizicolus Muir vector, which as a whole makes difficult achieving satisfactory efficiency of selection for that character. The identification of several SSRs asociated with resistance to RHBV (Calvert et al., 2006) in two populations developed at CIAT F2/F3 from crosses between highly susceptible line WC366 and resistant varieties and sogata RHBV: Fedearroz 2000 (Fd2000) and Fedearroz 50 (Fd50), respectively, the objective of this research is to introgression of QTLs controlling resistance to RHBV in two susceptible elite lines achieve an acceptable level of resistance in three or four generations, mainly using genetic information. In this project, molecular markers were used to select the resistance to RHBV from the donor parent Fd2000 and genetic background in backcrossing populations. Based on RHBV resistance scoring, the level of polymorphism and other agronomic traits, we selected the two elite lines CT18685-10-3-1-2-2-M and Fd174 like candidates for introgression of QTLs. F1 heterozygous plants derived from crosses between the two elite lines and the donor of the resistance were backcrossed to the elite lines. In the BC1F1 generation, individuals that possessed the resistance alleles at the QTLs were backcrossed to obtain BC2F1 and BC3F1 families, from which BC3F2 seeds were obtained by selfing. The detection of introgressions from the Fd2000 resistant parent in the two elite lines, allowed selecting 177 resistant plants to RHBV. This Marker-Assisted Backcrossing (MAB) approach will grandly speed up and facilitate the identification and selection of elite resistant lines to RHBV.Maestrí
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Mapdisto: fast and efficient computation of genetic linkage maps
No full textMapDisto is a program for mapping genetic markers in experimental segregating populations like backcross, F2, doubled haploids, single-seed descent and highly recombinant lines.
One of its specificities is to propose recombination fraction estimates in case of segregation distortion.
MapDisto has many features such as drawing genetic maps, computing allelic disequilibrium, finding linkage groups, automatic ordering of loci, simple QTL analysis and exporting data and maps for other mapping software. MapDisto needs Microsoft® Excel to run. Supported versions are Excel 2003 to 2010 for Windows; Excel 2004 and 2011 for Mac OS X
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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