1,720,956 research outputs found
Impact of breeding during the 19th century on the genetic diversity of French cultivated roses (Rosa sp.)
No full textL’hybridation avec des ressources génétiques allochtones est largement pratiquée chez les plantes ornementales pour introduire de nouveaux caractères. Au cours du 19e siècle, âge d’or de la sélection des rosiers en France, des rosiers asiatiques ont été introduits en Europe. L’objectif ici est d’étudier l’évolution de la diversité génétique des rosiers cultivés en France au cours de cette période. La diversité a été étudiée à l’échelle du génome puis à l’échelle de gènes candidats codant pour des caractères potentiellement sélectionnés au cours du 19e siècle. Un échantillon de 1228 rosiers illustrant la diversité génétique des rosiers français cultivés à cette période a été génotypé avec 32 microsatellites. Une large diversité, structurée en seize groupes génétiques et une différenciation entre les rosiers anciens européens et les rosiers asiatiques ont été détectées. Un déplacement du fond génétique des hybrides cultivés d’un type européen vers un type asiatique a été observé au cours du 19e siècle. Les croisements fréquents et/ou la sélection pour des caractères présents chez les rosiers asiatiques ont pu induire cette évolution. Certains caractères phénotypiques, comme la remontée de floraison, deviennent prépondérants. Onze gènes candidats ont été séquencés et leur diversité a été analysée sur un sous-échantillon de 365 rosiers. Parallèlement au fond génétique, certains gènes présentent un rapprochement génétique vers des allèles asiatiques. Pour le gène KSN, une augmentation de la fréquence d’allèles portant le rétrotransposon copia, responsable de la remontée de floraison, est observée.Innovation in ornamental plant breeding is commonly obtained by hybridization with newly introduced genetic resources. During the 19th century, golden age for rose breeding in France, Asian roses were introduced in Europe. Our objective here was to study and explain the evolution of rose genetic diversity in France during this period of time. The diversity was studied at the genome scale and at the candidate gene scale. A large sample of 1228 garden roses illustrating the French rose diversity from this period of time was genotyped with 32 microsatellites markers. A wide diversity, structured into sixteen genetic groups, was observed. A geneticdifferentiation was detected between ancient European and Asian accessions and a continuous temporal shift was observed in cultivated hybrids from a European to an Asian genetic background during the 19th century.Frequent crosses with Asian roses along the 19th century and/or selection for Asiatic traits may have induced this shift. Some phenotypic traits, like continuous flowering, became overriding traits. Eleven candidate genes, which were potentially selected during the 19th century, were sequenced and their diversity was analyzed on a subsample of 365 roses. Simultaneously to the genetic background, some genes are gettingcloser to Asian alleles. For the KSN gene, an increase in the frequency of alleles carrying the retrotransposon copia, responsible for continuous flowering, is observed
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
Studying genetic control fo partial resistance to Aphanomyces cochlioides (Drech) in Sugar-Beet (Beta vulgaris L.)
No full textAphanomyces cochlioides is a fungus whose incidence is rapidly increasing in sugar beet crops. It causes root damage and yield loss in the USA, China and increasingly in eastern Europe. This is a very unpredictable disease. Trying to control it is an important issue and breeding for resistance is the most probable route to a solution. To learn more about the genetic control of the disease, a linkage analysis of QTL was performed. Previous assays made by SESVanderHave were used as a starting point and QTLs were found on chromosomes 4 and 6. However the phenotyping techniques were not well adapted and the development of a suitable bioassay had to be made prior to the QTL analysis. In the present work, new methods were developed but the results showed no correlation with those of the conventional technique, despite a good discrimination of the controls. The fine mapping assay detected a QTL on chromosome 1. These results are of an interest to use in resistance breeding in sugar beet.Aphanomyces cochlioides est un champignon pathogène critique dans les cultures de betterave à sucre. Il cause de nombreux dommages et des pertes de rendement aux États-Unis, en Chine et de plus en plus dans l'est de l'Europe. C'est une maladie très imprévisible. La lutte contre ce champignon est donc un enjeu important et la sélection pour la résistance est un moyen de lutte en développement. Pour connaître mieux le contrôle génétique de la résistance, une analyse QTL de liaison a été réalisée. Les essais précédents menés par SESVanderHave ont été utilisés comme prérequis, des QTLs avaient été trouvés sur les chromosomes 4 et 6. Cependant, la technique de phénotypage n'était pas très adaptée et il a fallu d'abord développer un bioessai avant l'analyse QTL. Dans le travail réalisé ici, malgré une bonne discrimination entre témoins, la comparaison des résultats obtenus avec la technique utilisée conventionnellement n'indique aucune corrélation. L'essai de cartographie fine montre quant à lui un QTL sur le chromosome 1. Ces résultats montrent un intérêt pour l'utilisation de la résistance en sélection
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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