1,720,956 research outputs found
EFFECTS OF IONIZING-RADIATION ON HUMAN CONJUNCTIVAL EPITHELIAL-CELLS - A CLINICAL AND CYTOLOGIC STUDY
No full textIn order to identify early and late modifications induced by ionizing radiation on the conjunctival surface, we studied 10 patients irradiated for paranasal sinus tumors. A clinical and morphological study of conjunctival epithelium (using an impression cytology technique) was performed; 5 patients were examined during and the others after treatment. Actinic conjunctivitis and keratitis, observed during treatment, reappeared within a few months after the end of radiotherapy. At a threshold dose of 25 Gy, chronic nuclear changes and cellular surface disorganization of the conjunctival epithelium were found - these progressed and persisted. Our data support the importance of careful monitoring of such irradiated patients and the benefit of planning a prospective clinical study to evaluate the effects of available drugs (all-trans retinoic acid) in the treatment of these lesions
MACULAR DRUSEN AND THE SENSITIVITY OF THE CENTRAL VISUAL-FIELD
No full textAbstract: Macular drusen are one of the earliest signs of age-related macular degeneration but little information is available on the functional aspects of macular area in patients with drusen. To determine if drusen are associated with changes in central visual field sensitivity, one eye of each of 35 subjects (mean age 64.9 years) with bilateral drusen and visual acuity of 1.0 (20/20) underwent automated static threshold perimetry of the central 10 degrees. 16 normal subjects (mean age 65.8 years) were used as controls. 30 degrees fundus photographs were graded in a masked fashion for the clinical characteristics of drusen, type, size and number. The mean sensitivity (MS) of the central 10 degrees was significantly lower in eyes with drusen compared to normal eyes (p=.0001). After grading drusen eyes for size (greater than or equal to 63 mu) and type (presence of soft drusen), MS significantly deteriorated when large and soft drusen were present. These results suggest that central visual field sensitivity is precociously affected in eyes with drusen and that testing central visual field sensitivity may be useful as functional parameter in long term studies on the evolution of age-related macular degeneration
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
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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