1,721,006 research outputs found
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
Risk of hepatitis C virus infection in a population exposed to biological materials.
Full text linkOBJECTIVES:
The seroprevalence of hepatitis A virus antibodies was investigated in a population of 1051 subjects, of whom 376 were controls and 675 were exposed to different degrees of biological risk.
METHODS:
The exposed group was subdivided into subjects at low (242), intermediate (265), and high (168) biological hazard; all subjects were employed in the biomedical field. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were also determined.
RESULTS:
The seroprevalence of positive hepatitis A antibodies was 44.9% in all subjects but was significantly higher in males (50.6%) than in females (34.2%) and increased according to age (25.9% in subjects aged 40 years). No difference related to exposure to the biological risk was observed. The prevalence of transaminases at levels above normal values (chi2 = 4.079, P<0.05 for AST and chi2 = 4.806, P<0.05 for ALT) and mean values (AST P<0.05; ALT P<0.001) appeared significant in hepatitis A virus-positive subjects. On the other hand, excluding individuals with positive hepatitis C virus antibodies (16) and positive hepatitis B virus surface antigen (12), a prevalence of transaminase alterations was not observed, but mean levels of ALT lasted significantly longer in subjects with positive hepatitis A virus antibodies (P<0.01).
CONCLUSIONS:
The results confirm that hepatitis A virus is not a risk for employees in the biomedical field, but the presence of hepatitis A virus antibodies suggests a possible, though not clinically evident, liver involvement
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
Marcatori dell’epatite A, B, C e valutazione del rischio biologico nei dipendenti universitari
No full textI marcatori dell’epatite A, B e C sono stati determinati in 467 dipendenti universitari esposti a rischio biologico. Sono stati individuati tre gruppi di rischio, a seconda della possibilità di contatto con materiale potenzialmente infetto. Non discostandosi dalle medie nazionali i dati relativi all’epatite A e C, più rilevanti appaiono i risultati riguardanti la prevalenza di epatite B. Tenendo presente la non sufficiente sensibilizzazione dei soggetti a rischio verso la vaccinazione, è da sottolineare come sia presente una modulazione della prevalenza di sieroconversione (spesso senza evidenza clinica) in soggetti a rischio più elevato
Glutamine transaminase K intranephron localization in rats determined by urinary excretion after treatment with segment-specific nephrotoxicants.
Full text linkGlutamine transaminase K(GTK) excretion assessed in urine and by kidney histology was evaluated in rats after single treatment with 1.0 mg/kg i.p. of mercuric chloride, 100 mg/kg i.p. of hexachloro-1:3-butadiene (both S3, pars recta, segment-specific nephrotoxicants) and 25 mg/kg s.c. of potassium dichromate (S1-S2, pars convoluta, segment-specific nephrotoxicant). The aim was to correlate segment-specific injury and enzyme excretion in order to assess, using non-vasive methods, localization of GTK along the proximal tubule. Mercuric chloride and hexachloro-1:3-butadiene produced early focal damage in the pars recta (focal necrosis was shown 10 h after treatment, and diffuse necrosis appeared later at 34 and 24 h after treatment). Changes of the pars convoluta were occasional and delayed (72 h after treatment for both substances). On the contrary, potassium dichromate induced damage of the pars convoluta (vacuolar degeneration and focal necrosis were evident 24 h and 48 h after treatment, respectively), whereas the pars recta was affected later (focal vacuolar degeneration was observed 72 h after treatment). Increase urinary GTK excretion was early after treatment with mercuric chloride and hexachloro-1:3-butadiene (significant increase was observed within 10 h), with a peak for both substances 24 h after treatment, in agreement with the necrosis of the pars recta. Potassium dichromate induced a significant increase of enzyme excretion in urine also 24 h after injection, according to histological features showing vacuolar degeneration of the pars convoluta; the peak of excretion was reached 48 h after treatment (delay was due, probably, to s.c. administration). The results show that GTK increased in urine after treatment with S3 and S1-S2 specific nephrotoxicants; the combination of histological examination and urinary enzyme supports the evidence that the enzyme is distributed along the whole of the proximal tubule
RE: Onuma H, Tsuji K, Hoshino T, Inomata K, Udo M, Nakagawa Y, Katagiri H, Miyatake K, Watanabe T, Sekiya I, Muneta T, Koga H. Fibrotic changes in the infrapatellar fat pad induce new vessel formation and sensory nerve fiber endings that associate prolonged pain. J Orthop Res. 2020 Jun;38(6):1296–1306
No full textAppropriate 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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