1,721,246 research outputs found
Root and crown tot of olive caused dy Phytophthora spp.
Phytophthora root and crown rot has been traditionally considered a minor disease of olive. However, in recent years it has
been recognized as an emerging problem in several olive-growing countries such as Australia, Italy and Spain probably as a
consequence of the expansion of plantings in new areas with heavy soils and the more intensive use of irrigation in both olive nurseries and commercial groves. The disease has been reported from most olive-growing countries and is caused by several soil -borne species of Phytophthora, including P. cinnamomi, P. citricola, P. cryptogea,
P. drechsleri, P. gonapodyides, P. inundata, P. megasperma,P. nicotianae and P.palmivora. Diagnosis is currently based on the
isolation and identification of isolates by both traditional and molecular methods. New molecular techniques are currently available that could be applied for both the identification of isolates and Phytophthora infections directly in host-tissues as well as insoil and water samples. A number of dedicated databases could improve the efficiency of these techniques. Moreover, DNA analysis has greatly contributed to phylogenetic studies of Phytophthora. Control of Phytophthora root and crown rot of olive is mainly based on preventive measures
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
Il pane a pasta acida dell'area Iblea: tradizione e tecnologia.
Il pane a pasta acida dell'area Iblea: tradizione e tecnologia
Variations on the Author
“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
We 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
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