1,720,963 research outputs found
Editorial. Today’s pedagogy: the challenges of the present. Research paths. The current time of coronavirus
Full text linkEditoriale. Pedagogia dell’oggi: le sfide del presente. Percorsi di ricerca. Il tempo odierno del coronavirus
Full text linkSTUDY OF THE SEXUAL MATURITY OF FEMALE BLUEFIN TUNA: PURIFICATION AND PARTIAL CHARACTERIZATION OF VITELLOGENIN AND ITS USE IN AN ENZYME-LINKED IMMUNOSORBENT ASSAY
No full textPlasma steroid levels of female bluefin tuna (BFT) Thunnus thynnus rose from c. 1.5 ng ml-1 during the quiescent period (March) to c. 7 ng ml-1 during the ripening period (May). Testosterone (T) increased further to c. 8 ng ml-1 during the pre-spawning period (June) while 17β-oestradiol (E2) began to decrease. In the post-spawning period (August) steroid levels decreased to <1 ng ml-1. Vitellogenin (Vtg) plasma levels seemed to follow changes in E2, showing an increase from the quiescent period to the ripening period of c. 18 mg ml-1, decreasing slightly before spawning, and then decreasing after spawning. The Vtg content in plasma showed a good correlation both with the plasma levels of E2 and T and with the percentage of vitellogenic oocytes at different periods of the reproductive cycle. Thus the ELISA could be taken as validated. Immunohistochemical staining of ovaries with anti BFT-Vtg serum demonstrated a high cross-reactivity with yolk proteins allowing the identification of vitellogenic oocytes
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
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
Study of first sexual maturity in female bluefin tuna (Thunnus thynnus) from the central Mediterranean sea.
No full textThis preliminary study indicates that the minimum size at maturity is 110 cm (LF) in female bluefin
tuna (BFT) from the Mediterranean Sea. It is notable that pre-adult specimens (with LF ranging from 100 to 110
cm) showed signs of gonadal development, characterized by the appearance of oocytes in the lipid stage. This
finding occurred contemporaneously to both the appearance of E2 and Vtg in the plasma. The evidence of the
present study needs to be confirmed in a larger fish sample including sampling at thè different phases of thè
reproductive cycle
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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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