1,721,109 research outputs found
Some hypotesis on the reduction of the antennae in Diaspis echinocacti female (Rhynchota Diaspididae) during ontogenesis.
No full text
Port management performance and contextual variables: Which relationship? Methodological and empirical issues
No full text
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
The kinetic inhibition of Acetylcholinesterase from human erytrocytes by tacrine and some tacrine derivatives
No full textThe kinetics of the reaction catalyzed by human erythrocyte Acetylcholinesterase (AChE) is studied in the presence of its inhibitor Tacrine (1,2,3,4-tetrahydro-9-acridinamine), and of two newly synthesized compounds, 6-metoxy-Tacrine and N-eptyl-Tacrine. The proposed kinetic model describes the rate of the enzymatic reaction in terms of competitive and uncompetitive mixed inhibition of the three different inhibitors. The kinetic parameters describing the rate of the reaction are obtained. The competitive and uncompetitive inhibition constants of the different inhibitors are reported and the mixed competitive–uncompetitive inhibition is discussed
Dosaggio microdensitometrico dell'attività glucoso 6-fosfato deidrogenasica in spermatozoi di topo e di coniglio nel corso della perossidazione lipidica spontanea.
No full textpoichè il glutatione, in qualità di substrato per il sistema enzimatico glutation/perossidati/reduttasi, garantisce un'efficace difesa nei riguardi dei danni provocati dalla perossidazione lipidica, sono stati studiati spermatozoi di topo (ad elevato contenuto in glutatione) e di coniglio (a basso contenuto in glutatione) incubati in media che consentono il realizzarsi di fenomeni di perossidazione lipidica. le indagini citochimiche quantitative sull'attività G6PDH condotte con metodo microdensitometrico hanno messo in luce l'esistenza, in entrambe le specie, di una correlazione dell'intensità di produzione di NADPH attraverso lo shunt dei pentosi con il contenuto intracellulare in glutatione e con il grado di perossidazione lipidic
- …
