1,720,976 research outputs found
Cytogenetics of the amphipod Jassa marmorata Holmes 1903 (Corophioidea: Ischyroceridae): karyotype morphology, chromosome banding, fluorescent in situ bybridization and nuclear content
Physical mapping of rDNA genes, (TTAGGG)n telomeric sequence and other karyological features in two earthworms of the family Lumbricidae (Annelida: Oligochaeta).
Chromosome analysis and FISH mapping of ribosomal DNA (rDNA), telomere (TTAGGG)n and (GATA)n repeats in the leech Haemopis sanguisuga (L.) (Annelida: Hirudinea).
Shock timing in mitogynogenesis and tetraploidization of the European sea bass Dicentrarchus labrax
A two-step assay was performed under strictly controlled temperature (14±0.2 °C) to obtain mitogynogenetic and tetraploid offspring in the European sea bass (Dicentrarchus labrax L.). The first (probative) series of trials was aimed at adjusting both intensity and timing of the pressure shock to be applied for doubling chromosome set. Larval hatching (LH) (mean 1±1% for gynogenetic double haploids and 3±2% for tetraploids) was achieved only when the pressure shock was applied within 70–90 min after fertilization and the pressure intensity was set at 81–91 (MPa). Lower pressure (70–80 MPa) produced largely variable results and the lowest pressures (<70 MPa) were ineffective. The second series of trials (optimization) was performed to improve the yield in manipulated offspring by recording the time of the first cleavage in a preliminary fertilization test, and timing the application of the pressure shock accordingly. With this manipulation, mitogynogenesis and tetraploidization success rates consistently increased (mean LH 10±6% and 18±12%, respectively), producing live progeny. A significant linear regression was found between the optimal shock application time and the appearance of the first cleavage. The linear regression may be applicable to other fish species
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
FISH mapping of 18S-28S and 5S ribosomal DNA, (GATA)n and (TTAGGG)n telomeric repeats in the periwinkle Melarhaphe neritoides (Prosobranchia, Gastropoda, Caenogastropoda).
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
Dispelling the Myths Behind First-author Citation Counts
We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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