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Short taxonomic guide to the genus ‘Candidatus Phytoplasma’
No full textThe category of Candidatus was introduced to allow unambiguous reference to organisms that could not be cultivated in vitro. In plant pathology, a major impact of this novel taxonomic concept was to enable the classification of the diverse group of organisms, morphologically similar to the mycoplasmas, known by the trivial name of phytoplasmas. These plant pathogens were originally named according to the disease they caused. Later, extensive sequence analysis of the ribosomal RNA genes allowed the development of an evolution-based classification and the grouping of the phytoplasmas into phylogenetically distinct clades. Unfortunately, the phytopathological and the phylogenetic classification did not match and had striking contradictions. With the adoption of the category Candidatus, the description of the genus 'Ca. Phytoplasma' and several 'Ca. Phytoplasma' species, the scientific community is now attempting to provide a classification that takes into account both the phylogenetic and the biological/ecological characteristics of the organisms. Here we provide an outline of the characteristics and composition of the genus 'Ca. Phytoplasma'
Candidatus Phytoplasma spartii’, ‘Candidatus Phytoplasma rhamni’ and Candidatus Phytoplasma allocasuarinae’, respectively associated with spartium witches’-broom, buckthorn witches’-broom and allocasuarina yellows diseases
Get PDFChromosome mapping of the sweet potato little leaf phytoplasma reveals genome heterogeneity within the phytoplasmas
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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
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