1,720,977 research outputs found
A karyological study of the genus Pnigalio Schrank (Hymenoptera: Eulophidae): Assessing the taxonomic utility of chromosomes at the species level
No full textWe provide a karyological study of 12 species of the genus Pnigalio in an attempt to evaluate the taxonomic utility of karyotypes at the species level. For all species of Pnigalio examined the number of chromosome was 2n=12. Karyotype formulae presented mainly metacentric and submetacentric chromosomes, although a pair of acrocentrics or subtelocentrics, shorter than biarmed chromosomes, was present in some species. The analysis of karyotypes of Pnigalio showed frequent but not general interspecific variability of the chromosome traits. Although most of the studied species revealed concordance between morphological and karyological characters (centromeric index and relative length), two other categories have been identified: morphologically distinct species without reciprocal differences in karyotype structure, and morphologically similar species that strongly differ in chromosomal characters
Contributo alla caratterizzazione di Pnigalio pectinicornis L. (Hymenoptera: Eulophidae) e specie affini
No full textContributo alla caratterizzazione di Pnigalio pectinicornis (Hymenoptera: Eulophidae) e specie affini
No full textMolecules and morphology reveal unexpected cryptic diversity in the genus Necremnus Thomson (Hymenoptera: Eulophidae)
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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
Figure 1 in Pnigalio agraules (Walker) and Pnigalio mediterraneus Ferrière and Delucchi (Hymenoptera: Eulophidae): two closely related valid species
No full textFigure 1. Comparison of parsimony tree topologies for the two gene regions. (A) One of 28 most parsimonious trees found for the cytochrome oxidase subunit I (COI) dataset; (B) one of four most parsimonious trees found for the 28S-D2 dataset. Bootstrap values>70% are shown in bold above branches.Published as part of Gebiola, M., Bernardo, U., Monti, M.M., Navone, P. & Viggiani, G., 2009, Pnigalio agraules (Walker) and Pnigalio mediterraneus Ferrière and Delucchi (Hymenoptera: Eulophidae): two closely related valid species, pp. 2465-2480 in Journal of Natural History 43 (39-40) on page 2472, DOI: 10.1080/00222930903105088, http://zenodo.org/record/521741
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
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