1,720,956 research outputs found
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
Cicaline dell’agroecosistema vigneto: risultati di un quadriennio di indagini nelle Marche.
No full textGrapevine yellows are serious diseases that are caused by phytoplasma and are transmitted propagatively by phloem-feeding insects, mainly leafhoppers and planthoppers. the aim of the present study was of detrming the occurrence and distribution of leafhopper and planthopper vectors or suspected vectors of phytoplasma in the most important viticultural areas of the Marche region. In addition in some vineyard agroecosystems where Bois Noir (BN) was known to occur, the roots of herbaceous plants were checked for presence of H. obsoletus larval instars. This was of particular note for: Cirsium arvense, Convolvolus arvensis, Picris echioides, Plantago lanceolata, Potentilla reptans and Urtica dioica. Many species of Auchenorrhyncha were detected. No Scaphoideus titanus was found in the region. H. obsoletus larvae were collected only on U. dioica roots and adults were found, from June to August, rather on U. dioica and C. arvensis than on grapevine. U. dioica not always were found in or around vineyards in which H. obsoletus was detected. In some BN-affected vineyards, H. obsoletus populations were scarce and during the same period of observation Neoaliturus fenestratus was the most abundant known vector species and was found positive for BN causal agent
First report of root collar rot by Phytophthora cryptogea on sweet cherry in Italy
No full textSweet cherry (Prunus avium L.) cultivation has increased in Italy and ≈30,000 ha are now in production. In the spring of 2006, a disease survey was conducted in orchards of central Italy. Decline symptoms of Prunus avium ‘Durone’ grafted on wild rootstocks of Prunus avium consisted of reduced tree vigor, yellowing of leaves, and development of root and collar rot. A reddish brown discoloration of the inner bark and wood was observed on symptomatic trees. Symptoms were recorded in three cherry orchards seasonally submitted to soil saturation conditions. In one orchard, symptoms were observed on approximately 30% of 170 surveyed trees. A Phytophthora species was consistently isolated on PARPH-V8 medium (2) from collar lesions of five cherry trees over nine trees randomly chosen among symptomatic trees in the three orchards. Colonies (20) were isolated and all appeared fluffy on potato dextrose agar and did not grow at 35°C. The morphological characteristics fit the descriptions of Phytophthora cryptogea Pethybr. & Lafferty (1). Sequence analysis of the internal transcribed spacers region of isolates shared 100% homology with P. cryptogea (GenBank Accession Nos. EF418948.1, EF418943.1, and EF153671.1). Pathogenicity of two P. cryptogea isolates (AN1 and AN2, Accession Nos. EF661576 and EF661577, respectively) was tested by soil infestation in a growth chamber at 22°C using 15 1-year-old rooted seedlings of wild rootstock of Prunus avium for each isolate. Noninoculated seedlings (15) were used as negative controls. The inoculum was produced by growing isolates on autoclaved millet grains moistened with V8 juice for 4 weeks. Each plant was inoculated with 30 cm3 of inoculum per liter of soil. Each seedling was randomly assigned to isolates AN1, AN2, or the noninoculated control and arranged in a complete random design. All plants were flooded for 24 h every 2 weeks for 8 weeks. At the end of the experiment, all inoculated seedlings showed crown wilting and root rot. Control plants showed no symptoms. Percentage of necrotic lateral roots expressed as dry weight (±SE) was 19.9 ± 0.6, 17.5 ± 0.2, and 4.4 ± 0.5, respectively, for seedlings inoculated with isolates AN1, AN2, and controls (analysis of variance F = 7.48, P < 0.01). Values of inoculated seedlings were significantly different from the control plants with the Tukey Post-Hoc test. No difference in virulence was observed between the two isolates. P. cryptogea was always reisolated from the roots of inoculated plants. Although pathogenicity of P. cryptogea on sweet cherry has been reported in the United States and other European countries (3,4), to our knowledge, this is the first record of P. cryptogea on sweet cherry orchards in Italy. The presence of P. cryptogea in cherry orchards is of significant concern because of its aggressiveness to this host and woody hosts such as apple, apricot, peach, walnut, and kiwi
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
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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