1,720,974 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
Preliminary reports on morphological and ultrastructural changes in the corpora cavernosa of the rat after chronic arterial obstruction.
Various authors have investigated the pathological findings of penile tissue after chronic arterial obstruction, but the significance of these changes in the corpora cavernosa remains unclear. In order to evaluate the possible damages in the erectile tissue after chronic arterial obstruction at different levels, we utilized an experimental model in rats to determine the changes in smooth muscle cells and elastic fibers of the erectile tissue by microscopic immunohistochemical and ultrastructural studies.Twelve adult male Wistar rats were employed in this study. Ten were used for the experiments and two as control. The rats were anaesthetized with ether and intraperitoneal 10\% chloral hydrate. Microsurgical isolation of the involved vessels was performed with the aid of a Zeiss dissecting microscope. Partial stenosis was achieved with 11/0 nylon and amputation of the penis was performed at previously established time periods. The partial stenosis was carried out at the level of the aortic below the renal vessels (Group A), the common iliac artery on both sides (Group B) and the hypogastric artery on the left side (Group C). Arterial obstruction was maintained in each group for 50, 40 and 25 days, respectively.In comparison with normal controls, the histological findings revealed discrete and diffuse interstitial hyalinosis with reducted elastic fibers, while dilated vascular lacunae were also present on TEM (Transmission Electron Microscope) and SEM (Scanning Electron Microscope) examination. The greatest ultrastructural damages were observed in the group with obstruction of the common iliac artery on both sides. The foregoing confirms that an eventual chronic obstruction of these arteries does not allow the formation of collateral vessels for the corpora cavernosa
Epidemiological aspects of endometrial carcinoma in North-Sardinia. Considerations of 318 cases
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
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