1,720,957 research outputs found
Rep-PCR fingerprinting of Xanthomonas arboricola strains isolated in Chile from Corylus avellana symptomatic plants
No full textIn Xanthomonas genus, which includes Gram-negative bacteria mainly phytopathogenic against various host plants, the Xanthomonas arboricola species has a high genetic variability and, among the current 9 pathovars, pv. corylina causes the halzenut bacterial necrosis which is the main disease present in all hazelnut cultivation areas. In this study, 19 X. arboricola and 21 X. arboricola pv. corylina strains isolated in Chile, during 2018, from Corylus avellana symptomatic plants were characterised by Rep-PCR analysis (ERIC, BOX, REP). The genetic profiles of all strains were transformed into binary matrices which were processed by UPGMA method in single or concatenated way using Jaccard similarity coefficient. Thirteen X. arboricola reference strains belonging to the pathovars celebensis, pruni, juglandis and populi were used as controls, while the DISTAL 9081 strain of X. axonopodis pv. vitians was used as outgroup. The UPGMA cluster analysis of Rep-PCR fingerprints divided the 51 X. arboricola strains into 5 statistically significant groups corresponding to the relative pathovars: pruni, corylina, juglandis, celebensis and populi. The X. arboricola pv. corylina strains showed a high genetic variability (approx. 45%). The Rep-PCR fingerprints of the X. arboricola strains isolated from symptomatic hazelnut shoots and leaves gave similar results with a similarity value of approx. 50% among strains which were included in the corylina pathova
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
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
Xanthomonas arboricola pv. corylina, causal agent of hazelnut bacterial blight: phenotypic and genomic characteristics of Chilean strains
No full textNowadays, the worldwide most important disease affecting hazelnut trees is caused by the highly host specific Xanthomonas arboricola pv. corylina (Xac). In fact, bacterial blight of Corylus avellanae (BBCa) reduces the vigour mainly of young hazelnut plants with devastating damages and yield losses either in orchards or in nurseries where the negative consequences on production are even worse. Recently, first reports of BBCa in European countries are on the rise, and serious outbreaks have been detected in Serbia, Italy and Chile. The prevalence of BBCa in Chile and favourable environmental factors in commercial orchards and nurseries are only partially known. Since in Chile the knowledge on pathogenicity and epidemiology of Xac is poorly understood, Xac Chilean strains from European hazelnut symptomatic plants, either from both commercial orchards and nurseries, were characterized with polyphasic approach in order to develop an integrated Xac control strategy. As the Xac lies within the Xanthomonas arboricola (Xa) species, which has a high genetic variability and has been intensively studied because of its strain specialization and host range complexity, the metabolic activity of 21 Xac strains and 19 Xa was evaluated using a Biolog GenIIITM analysis. 13 out of 19 Xa reference strains belonging to the pathovars celebensis, pruni, juglandis and populi were used as controls, while DISTAL 9081 strain of X. axonopodis pv. vitians as outgroup. The phenotypic analysis confirmed the data obtained by Rep-PCR: a) Xac strains showed a high genetic variability (approx. 45%); b) the Rep-PCR fingerprints of the Xa strains isolated from symptomatic hazelnut shoots and leaves gave similar results with a similarity value of approx. 50% among strains which were included in the corylina pathovar. Bioassays (hypersensitive response) and pathogenicity tests were also carried out
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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