1,720,955 research outputs found
Diversidad fenotípica de cultivares de palmera datilera (Phoenix dactylifera L.) de Argelia
Get PDFThe aim of this work is to evaluate the phenotypic diversity of date palm (Phoenix dactylifera L.). This study shows that Biskra region has an interesting biodiversity. This latest was conducted during the growing palm groves since 3 years (2010, 2011 and 2012) in Biskra, on 89 date palm varieties, to identify their distinctive phenotypic characteristics. Seventeen physical parameters have been examined, including 4 relative to vegetative growth, and 13 to the fruits at the date parameters stage. The main components analysis was used to identify the differences and similarities between the parameters studied. The principal component analysis showed that morphological characters for fruits should be used for identifications and descriptions of date palm cultivars. The results revealed a wide variation for different degrees of significance between the 89 cultivars for most studied traits, and showed the superiority of the fruiting characteristics over the vegetative, the former included: Fruit weight 0.851 and length 0.746, flesh weight 0.865, the coefficient of fruit length/width 0.754 and the weight coefficient flesh/seed 0.675. These features had significant representation, as they helped significantly in finding 18 well identified varieties. The results analysis showed three homogeneous groups varieties sharing some traits, the convergence rate is different from one class to another within the same group. This study allowed us to highlight the most discriminating characters that can be used for further studies of diversity.El objetivo de este trabajo es evaluar la diversidad fenotípica de la palmera datilera (Phoenix dactylifera L.). Nuestro estudio muestra que la región de Biskra cuenta con una interesante biodiversidad. Este estudio se llevó a cabo durante 3 años de crecimiento (2010, 2011 y 2012) en Biskra, para 89 variedades de palmera datilera, para identificar sus características fenotípicas distintivas. Se analizaron 17 parámetros físicos, 4 de ellos relacionados al crecimiento vegetativo y 13 durante la etapa de fruto. Se utilizó el análisis de componentes principales para identificar las diferencias y similitudes entre los parámetros estudiados. El análisis de componentes principales mostró que los caracteres morfológicos de las frutas deben ser utilizados para identificaciones y descripciones de variedades de palmera datilera. Los resultados revelaron una amplia variación para diferentes grados de importancia entre los 89 cultivares para los rasgos más estudiados, y mostraron la superioridad de las características de fructificación frente a los de vegetación para distinguir las variedades. Estos resultados incluían: peso del fruto 0,851, longitud del fruto 0,746, peso de la pulpa del fruto 0,865, coeficiente longitud/ancho del fruto 0,754 y coeficiente peso pulpa/semilla 0,675. tienen representación significativa para diferenciar 18 variedades. Los resultados del análisis estadístico mostraron que hay tres grupos homogéneos de variedades que presentan similitudes en algunas de las características estudiadas, y la tasa de convergencia era diferente de una clase a otra dentro del mismo grupo. Este estudio nos ha permitido poner de relieve los caracteres discriminantes que pueden ser utilizados para otros estudios de diversidad
Phenotypic diversity of date palm cultivars (Phoenix dactylifera L.) from Algeria
No full textThe aim of this work is to evaluate the phenotypic diversity of date palm (Phoenix dactylifera L.). This study shows that Biskra region has an interesting biodiversity. This latest was conducted during the growing palm groves since 3 years (2010, 2011 and 2012) in Biskra, on 89 date palm varieties, to identify their distinctive phenotypic characteristics. Seventeen physical parameters have been examined, including 4 relative to vegetative growth, and 13 to the fruits at the date parameters stage. The main components analysis was used to identify the differences and similarities between the parameters studied. The principal component analysis showed that morphological characters for fruits should be used for identifications and descriptions of date palm cultivars. The results revealed a wide variation for different degrees of significance between the 89 cultivars for most studied traits, and showed the superiority of the fruiting characteristics over the vegetative, the former included: Fruit weight 0.851 and length 0.746, flesh weight 0.865, the coefficient of fruit length/width 0.754 and the weight coefficient flesh/seed 0.675. These features had significant representation, as they helped significantly in finding 18 well identified varieties. The results analysis showed three homogeneous groups varieties sharing some traits, the convergence rate is different from one class to another within the same group. This study allowed us to highlight the most discriminating characters that can be used for further studies of diversity
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
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
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