1,721,012 research outputs found

    Legacy of tradition in plant geography

    No full text

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Get PDF
    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

    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

    Appropriate Similarity Measures for Author Cocitation Analysis

    Get PDF
    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

    Patterns of seed polymorphism and allozyme variation in the bladder campions, <i>Silene vulgaris</i> and <i>Silene uniflora</i> (Caryophyllaceae)

    No full text
    Seed morphology (testa ornamentation and seed shape) and allozyme variation were investigated in three closely related and partially sympatric taxa of Silene in the Nordic region. Within this region, Silene vulgaris is a widespread weed of anthropogenic habitats. The two subspecies of Silene uniflora are restricted to naturally open habitats; ssp. uniflora has a coastal distribution, whereas the Swedish endemic, ssp. petraea, is restricted to limestone habitats on the islands of Öland and Gotland. All three taxa show a seed ornamentation polymorphism, with individuals producing either tubercled or smooth ("armadillo") seeds. Both seed morphology and allozymes show a separation between the two species Silene vulgaris and Silene uniflora and support the present taxonomic treatment of the endemic "petraea" as a subspecies of Silene uniflora. Tubercled seeds predominate in Silene vulgaris and armadillo seeds predominate in Silene uniflora. However, there is considerable between-population variation in seed morph frequencies within taxa. In contrast to the other two taxa, populations of Silene uniflora ssp. petraea consistently show intermediate frequencies of both seed morphs. Silene uniflora ssp. petraea has the lowest between-population component of diversity in both seed shape (18–46%) and allozymes (0.8%) and shows no significant geographic structure in any of the character sets. Both Silene uniflora ssp. uniflora and Silene vulgaris show significant geographic differentiation in allozymes and seed morphology. The highest between-population component of diversity was found in Silene uniflora ssp. uniflora, where 17% of the total allozyme diversity and 39–82% of the seed shape diversity are accounted for by differences between populations. Key words: allozymes, geographic differentiation, diversity, seed shape, elliptic Fourier coefficients, Landmark characters. </jats:p
    corecore