1,720,994 research outputs found
Análisis multivariado aplicado a la representación de datos sintéticos de secuenciación de ARN
Full text linkTesis (Maestría en Estadística Aplicada) -- Universidad Nacional de Córdoba. Facultad de Ciencias Económicas. Escuela de Graduados; Argentina, 2017.Fil: Reeb, Pablo Daniel. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas. Escuela de Graduados; Argentina.La secuenciación de alto rendimiento de ARN genera grandes bases de datos con información que puede ser utilizada con diferentes objetivos. Una de las aplicaciones más utilizada consiste en resumir las lecturas de las secuencias agregándolas en función de una unidad de interés tal como gen, exón o transcript . En este tipo de análisis se obtienen matrices con datos de conteos correspondientes a cada individuo en estudio (filas) y asignados a una particular unidad de interés (columnas). En general el número de individuos es muy pequeño en relación al número de variables y los conteos presentan un rango de dispersión muy amplio.
En esta tesis se comparan técnicas de análisis multivariado exploratorio a 2 y 3 vías de clasificación que contemplan la naturaleza de los datos obtenidos en experimentos de secuenciación de ARN. Utilizando datos sintéticos generados con la técnica de plasmodios se comparan transformaciones a los datos y medidas de disimilaridad empleadas en el análisis
de cluster jerárquico, análisis de escalamiento multidimensional métrico y no métrico y en el análisis factorial multiple. La transformación de los conteos originales a través de funciones que utilizan logaritmo o el uso de disimilaridades basadas en correlacion de Spearman o disimilaridad Poisson rescata la estructura natural de las muestras en todos los métodos de
análisis utilizados. La mera estandarización o normalización de los conteos no genera representaciones confiables. La elección de la mejor medida debe considerar el nivel de relación señal-ruido ya que no todas las medidas muestran la configuración natural de la muestras en función de la cantidad de transcripts expresados o no diferencialmente. Este aspecto debe considerarse al momento de representar las muestras utilizando todos transcripts obtenidos o filtrando por expresión diferencial.Fil: Reeb, Pablo Daniel. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas. Escuela de Graduados; Argentina
¿Cómo asegurar un buen nivel de floración y cuaje en manzanos Red Delicious?
Full text linkEl principal cultivar de manzanos plantado en la Norpatagonia es ‘Red Delicious’ y sus clones, con alrededor de 11.000 hectáreas y cerca del 65 % de la superficie de los manzanos (SENASA, 2021). Un problema habitual en este cultivar es la escasa floración o el bajo nivel de cuaje en determinadas ocasiones. Cualquiera de estas dos situaciones impide sostener una producción de manzanas de calidad en el
tiempo.EEA Alto ValleFil: Curetti, Mariela. Instituto Nacional Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Alto Valle; ArgentinaFil: Raffo Benegas, María Dolores. Instituto Nacional Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Alto Valle; ArgentinaFil: Reeb, Pablo Daniel. Universidad Nacional del Comahue. Facultad de Ciencias Agrarias; ArgentinaFil: Rodriguez, Andrea Betiana. Instituto Nacional Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Alto Valle; Argentin
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variations on the Author
Full text link“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
Fruit drop and bloom return according to time of metyamitron application for chemical thinning in 'Red Chief' apple
No full textTrabajo presentado al EUFRIN Fruit Thinning Working Group Symposium. Belgrade (Serbia), febrero 2020Early removal of some of the fruits in apple trees improves the quality of remaining fruits at harvest and ensures adequate bloom return. An excess of fruits inhibits the flower bud induction in apple trees, a process that occurs between three and eight weeks after bloom. The objective of this work was to describe fruit drop during spring according to different chemical thinning and its relationship with bloom return in ‘Red Chief’ apple trees. Metamitron (MM) applications at a concentration of 200 ppm were done when mean fruit diameter were 8, 12 and 16 mm (between 15 and 28 days after full bloom) in three seasons: 2018-19, 2019-20 and 2020-21. Thinning effectiveness was evaluated by fruit set two months after bloom and fruit number tree‑1 at harvest. Fruit drop was recorded weekly, by counting the number of persisting fruits in six clusters tree‑1 during spring. Bloom return was determined by the number of flower clusters tree‑1 in the following season. Bloom return presented a strong negative correlation with fruit number per tree at harvest. Generally, MM treatments presented a higher percentage of dropped fruits around 20 days after application. The percentage of dropped fruits in the trees sprayed with MM at 16 mm was only higher with respect to control after ≈40 days after full bloom. Even so this late thinning treatment improved bloom return, indicating that floral induction may also occur later in the season.EEA Alto ValleFil: Curetti, Mariela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Alto Valle; ArgentinaFil: Raffo Benegas, María Dolores. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Alto Valle; ArgentinaFil: Reeb, Pablo Daniel. Universidad Nacional del Comahue. Facultad de Ciencias Agrarias; Argentin
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
Raleo manual en peral
Full text linkEl raleo manual de frutos en peral es una práctica muy difundida en el Alto Valle de Río Negro y Neuquén. Existe una estrecha relación entre el tamaño de fruto durante la estación de crecimiento y el logrado en cosecha. Por lo tanto es posible dejar en la planta sólo los frutos que se estima alcanzarán los tamaños deseados comercialmente al final de la temporada.
Para poder discriminar por tamaño de fruto, es necesaria la confección de tablas de crecimientos de frutos que permitan, conociendo el tamaño del mismo en la primavera, predecir el alcanzado en el momento de la cosecha.
Información reproducida con autorización de los autores de la publicación “Tablas de raleo, 2006" - Fac. Cs. Agrarias - UNCoEEA Alto ValleFil: Bramardi, Sergio Jorge. Universidad Nacional del Comahue. Facultad de Ciencias Agrarias; ArgentinaFil: Tassile, Valentín. Universidad Nacional del Comahue. Facultad de Ciencias Agrarias; ArgentinaFil: Reeb, Pablo. Universidad Nacional del Comahue. Facultad de Ciencias Agrarias; ArgentinaFil: De Bernardin, Federico. Universidad Nacional del Comahue. Facultad de Ciencias Agrarias; ArgentinaFil: Curetti, Mariela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Alto Valle; Argentin
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