1,721,014 research outputs found
Revised typification of <i>Monoclea gottschei</i> Lindb. (Marchantiophyta: Monocleaceae)
No full textKey to hornworts (Anthocerotophyta) of Colombia
No full textA key is presented to seven genera and fifteen species of hornworts recorded from Colombia. Three species found in Ecuador but not yet in Colombia (Dendroceros crispatus, Phaeomegaceros squamuligerus, and Phaeoceros tenuis) are also included in the key
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
Liverworts New to Ecuador with Description of <i>Plagiochila priceana</i> sp. nov. and <i>Syzygiella burghardtii</i> sp. nov.
No full textAppropriate 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
Phylogenetic study of Mastigolejeunea (Marchantiophyta: Lejeuneaceae) and an amended circumscription of the genus Thysananthus
No full textMastigolejeunea is morphologically close to Thysananthus and the separation of these two genera has long been controversial. The relationship between Mastigolejeunea and Thysananthus is assessed based on Bayesian inference and maximum likelihood analyses of plastid psbA-trnH, trnG and trnL-F, and nuclear ITS. Mastigolejeunea was resolved as sister to Thysananthus with moderate support, but M. calcarata was nested in Thysananthus subsect. Anguiformes and M. florea was resolved in Spruceanthus. Because diagnostic morphological features separating Mastigolejeunea from Thysananthus are lacking, Mastigolejeunea is treated as a subgenus of Thysananthus. The latter group becomes the second largest genus of Lejeuneaceae subfam. Ptychanthoideae with 30 species, and is one of the largest genera of liverworts that has been monographed worldwide.</jats:p
On Metzgeria saccata Mitt. (Marchantiophyta: Metzgeriaceae) with description of a new species from South America
No full text- …
