1,720,992 research outputs found
COXIELLA BURNETII INFECTION IN DAIRY COWS AND GOATS: ASSESSMENT OF DIAGNOSTIC METHODS, AND EVALUATION OF IMMUNE RESPONSE IN SHEDDERS
Full text linkQ fever is an infective, contagious and zoonotic disease caused by Coxiella burnetii, an obligate intracellular bacterium. The first goal of this research was to assess the efficacy of a diagnostic strategy based on real-time PCR (r-t PCR) assays on bulk tank milk (BTM) for the detection of infected dairy herds/flocks, with the aim of estimating the prevalence of Q fever infection in dairy herds and in goats flocks. The second goal was to evaluate the dynamics of the antibodies response and the C. burnetii excretion in infected animals. The sensitivity and specificity of a single r-t PCR test on BTM were evaluated using a control-case study in dairy herds and goat flocks. To study the C. burnetii transmission in dairy herds and goats flocks a longitudinal study was performed. The sensitivity and specificity of BTM r-t PCR in dairy herds were respectively equal to 0.5 and 1, and in dairy flocks 0.8 and 1. The results highlighted in dairy cows a great gap between the seroprevalence and the percentage of shedders found in the herds. The seroprevalence was on average 30,6%, while the percentage of shedders was at least 13% and the percentage of strong shedders was only 1,7%. We observed also the presence of 14 cows shedding C. burnetii in milk without an appreciable serological response. Shedding in feces was sporadic and only 9 cows were found to shed the bacterium occasionally through this route. The goats sampled were 257, coming from 3 flocks very different in size, ranging from 12 to 171 goats. The shedders of C. burnetii in milk were 59 (23%), the ELISA seropositive goats 177 (69%), the CFT seropositive goats 11 (4%). The percentage of shedders in milk was very different among the flocks, ranging from 100% of farm 2 to 1% of farm 3. Shedding of C. burnetii in stools was detected only occasionally in flocks 2 and 3, while in flock 1 at 2nd sampling 15 positives goats were detected. The great majority of ELISA seropositive goats kept this status throughout the study time
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
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