1,720,984 research outputs found
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
EFECTO DE LA FERTILIZACIÓN CON ABONO ORGANICO (A.L.O.F.A) EN PLANTAS DE CAFÈ (Coffea arábica)
No full textLa fertilización de café con abono orgánico líquido fermentado aerobicamente (A.L.O.F.A.) al 4% + inoculantes micorrizicos aumento el rendimiento en el 44.6 en graneo y primera cosecha. Los tratamientos se realizaron desde el trasplante a campo y el efecto se evaluo sobre altura de planta, rendimiento y calidad de café. Se utilizó un diseños de bloques completos al azar con 3 repeticiones
Metodología para la selección de líneas de fríjol Phaseolus vulgaris L. por estrés de temperatura a nivel microgametofítico
Get PDF<p>Studies of various plant species have shown that a significant portion of the genes that are expressed in the sporophyte are also expressed in the microgametophyte (pollen grain). Consequently, selection pressure applied to pollen may aid in the modification of qualitative or quantitative characters of the derived progeny. To verify this hypothesis in common bean (Phaseolus vulgaris), a study of the effect of high temperature stress on pollen grain in three cultivars in F<sub>1 </sub>and F<sub>2 </sub>generations was conducted by means of "in vitro" germination techniques and controlled pollinization with stressed pollen. In vitro germination was inversely related with the level and duration of high temperature stress. As 50°C the stressed pollen showed considerable decrease in germination. Evaluation of germination of pollen between progenies showed no increase in tolerance to high temperature of microgametophytes. Greater progress in selection of microgametophytes be obtained using larger quantities of pollens, which would provide greater opportunity to select for vigor. The origen of the variability in the germination of pollen in cultivars in the flowering period should also be examined.</p><p>Los trabajos realizados en varias especies de plantas revelan que una porción significativa de los genes que se expresan en el esporofito también lo hacen en el grano de polen, en consecuencia la presión de selección a nivel de polen debe conducir a modificaciones en caracteres cualitativos o cuantitativos de las progenies derivadas. Para comprobar esta hipótesis en fríjol se estudió el efecto de estrés por temperaturas altas sobre granos de polen, en tres variedades de Phaseolus vulgaris L. y sus generaciones F<sub>1</sub> y F<sub>2</sub> mediante las técnicas de germinación "in vitro" y polinización controlada con polen estresado. El porcentaje de germinación " in vitro" estuvo inversamente relacionada con el nivel de estrés por temperaturas altas y el tiempo de exposición al estrés. 50°C resultó ser la temperatura a la cual el polen que se había sometido a estrés durante sesenta minutos presentó disminución considerable en su germinación. No se detectó avance para tolerancia a altas temperaturas a nivel de microgametofito cuando se evaluó germinabilidad de polen entre progenies. Un avance en la selección a nivel de microgametofito se puede lograr trabajando con mayores cantidades de polen lo que dará la oportunidad de seleccionar por vigor, además es importante explorar el origen de la variabilidad en la germinación de polen dentro de un material en la fase de floración.</p>
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Evaluación de métodos de propagación de alocasia macrorrhiza en el municipio de san pablo, Nariño
Get PDFEste estudio se realizó en el municipio de San Pablo (Nariño) con el objeto de evaluar métodos de propagación de (Alocasia macrorrhiza) y determinar el mejor para la obtención de material de siembra. Se utilizó un diseño de bloques completos al azar con 4 tratamientos y 4 repeticiones. Los tratamientos fueron: T1- discos del tallo, T2- yemas del tallo, T3- hijuelos y T4 cogollos. El material de propagación fue obtenido en el vivero municipal de San Pablo (Nariño), donde se encontraba un área aproximada de 400 m2 con bore, cuyo estado sanitario y productivo era aceptable. El análisis de varianza detecto diferencias significativas entre tratamientos para la variable altura de planta, mientras que para hojas/planta no hubo diferencias entre tratamiento. La prueba de Duncan permitió determinar que el método de propagación de cogollos fue el de mejor comportamiento logrando un promedio de 125,8 cm/planta. Al finalizar el ensayo, los métodos de discos del tallo e hijuelos fueron los que menor crecimiento presentaron con un promedio de 96,9 y 105,4 cm/planta, respectivamente. El número de hojas por planta es independiente del método de propagación utilizado, sin importar cual método se utilice la producción de biomasa foliar será la misma
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