1,720,974 research outputs found

    Quaternary radiation and genetic structure of the red fox "Vulpes vulpes" in the Mediterranean Basin as revealed by allozymes and mitochondrial DNA

    No full text
    The Quaternary dispersal of the red fox Vulpes vulpes in the Mediterranean area was evaluated through the study of allelic variation at 45 enzyme loci in 120 individuals from 10 sampling sites. A 375 bp fragment of the mitochondrial cytochrome b gene was also sequenced in a total of 41 specimens from the same sampling locations. Nine allozyme loci were polymorphic. The proportion of polymorphic loci per population (P) ranged from 0 to 15.6%, and expected average heterozygosity (H) from 0 to 4.4%. A total of 18 different Cyt b haplotypes were detected. Most of them were confined to only one population. Both allozyme and mtDNA data implied that our fox populations were genetically fairly isolated from one another, suggesting low gene flow between them. This isolation should be of comparatively recent origin according to the slight differentiation among Cyt b haplotypes. Fox populations appeared to belong to two genetically distinct groups. With a mean value of Nei's D = 0.024, genetic distance between these groups was similar to that detected at subspecies level in taxa of large mammals. This pattern may have originated from different colonization waves during Quaternary glaciations and deglaciations. Red foxes from Sardinia were more closely related to the Bulgarian foxes than to the Iberian ones. However, repeated introductions to Sardinia probably also occurred from Central Italy and Spain, as suggested by the presence of haplotype A and a typical Central Italian allele, Ck-2(90)

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Full text link
    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

    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
    corecore