1,720,998 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
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
“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
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
Zebrafish chromosome banding
Banding techniques were carried out on metaphase chromosomes of zebrafish (Danio rerio) embryos. The karyotypes with the longest chromosomes consist of 12 metacentrics, 26 submetacentrics, and 12 subtelocentrics (2n = 50). All centromeres are C-band positive. Eight chromosomes have a pericentric C-band in each arm and 22 chromosomes have one in the longest arm. Two chromosomes have a slightly heterochromatic long arm and five chromosomes have an Ag-NOR at the terminal end of the long arm. Other banding patterns and sex chromosomes could not be revealed
INITIAL ACYTOKINESIS DURING LEAF PROTOPLAST CULTURE OF DIHAPLOID AND TETRAPLOID SOLANUM-TUBEROSUM AND DIPLOID S-BULBOCASTANUM
MATURATION DIVISIONS WITH DOUBLE SOMATIC CHROMOSOME NUMBER IN PRIVET MITE BREVIPALPUS-OBOVATUS
SOMATIC HYBRID POTATO PLANTS AFTER ELECTROFUSION OF DIPLOID SOLANUM-TUBEROSUM AND SOLANUM-PHUREJA
Mosaic haploid-diploid embryos and polyspermy in the tellinid bivalve Macoma balthica
We investigated meiosis, fertilization, and early development in eggs of the tellinid bivalve Macoma balthica (L.), which has external fertilization. Meiosis is standard but polyspermy is found to be very common. In all eight crosses examined, mosaic embryos consisting of a mixture of diploid (2n = 38) and haploid cells occur at a frequency ranging from 2.7 to 29.1%. The earliest mosaic found is in the two-cell stage. We propose that an androgenic haploid cell lineage can originate from one supernumerary sperm that decondenses into a functional haploid nucleus, starts mitosis, and is incorporated in the developing embryo.</p
- …
