1,721,049 research outputs found
Monitoring drug efficacy against gastrointestinal nematodes when faecal egg counts are low: do the analytic sensitivity and the formula matter?
No full textComparison of individual and pooled faecal samples in sheep for the assessment of gastrointestinal strongyle infection intensity and anthelmintic drug efficacy using McMaster and Mini-FLOTAC.
No full texttA field study was conducted to validate pooled faecal samples in sheep for the assessment ofgastrointestinal (GI) strongyle infection intensity (faecal egg count – FEC) and anthelminticdrug efficacy (FEC reduction – FECR). Ten sheep farms located in the Campania region ofsouthern Italy were selected for the study. In each farm, individual faecal samples from 20adult sheep (when possible) were collected, before (D0) and after (D14) an anthelmintictreatment with albendazole. For each farm and at each time point (D0 and D14) the faecalsamples were examined individually and as pools. Specifically, three different pool sizes (5,10 and 20 individual sheep samples) and three different analytic sensitivities (namely 10using Mini-FLOTAC; 15 and 50 using the two variants of McMaster – McM15 and McM50)were compared for FEC and FECR using individual and pooled faecal samples. GI strongyleintensity (eggs per gram of faeces – EPG) of pooled samples correlated positively with meanEPG of individual samples, with very high correlation coefficients (ranging from 0.94 to 0.99)across the 3 different pool sizes and analytic sensitivities. Mini-FLOTAC was more sensitivecompared to the two variants of McMaster (McM15 and McM50) for the diagnosis of GIstrongyles in sheep (100% vs 88.5% vs 75.9%) and resulted in significant higher FEC comparedto both McM15 and McM50, with a mean difference in egg counts of approximately 90 EPG(p < 0.001). The drug efficacy results showed that FECR was higher than 98% at most farmsindependently of the pool size and analytic sensitivity. With the exception of two farms,FECR was 100% when calculated for individual animals and across the different pool sizeand analytic sensitivities. In conclusion, the present study highlighted that pooling ovinefaecal samples is a rapid procedure that holds promise as a valid strategy for assessing GIstrongyles FEC and FECR in sheep
The bias, accuracy and precision of faecal egg count reduction test results in cattle using McMaster, Cornell-Wisconsin and FLOTAC egg counting methods.
No full textThe faecal egg count reduction test (FECRT) is the recommended method to monitor anthelmintic drug efficacy in cattle. There is a large variation in faecal egg count (FEC) methods applied to determine FECRT. However, it remains unclear whether FEC methods with an equal analytic sensitivity, but with different methodologies, result in equal FECRT results. We therefore, compared the bias, accuracy and precision of FECRT results for Cornell-Wisconsin (analytic sensitivity = 1 egg per gram faeces (EPG)), FLOTAC (analytic sensitivity = 1 EPG) and McMaster method (analytic sensitivity = 10 EPG) across four levels of egg excretion (1-49 EPG; 50-149 EPG; 150-299 EPG; 300-600 EPG). Finally, we assessed the sensitivity of the FEC methods to detect a truly reduced efficacy. To this end, two different criteria were used to define reduced efficacy based on FECR, including those described in the WAAVP guidelines (FECRT 90%). Yet, the sensitivity of McMaster and Cornell-Wisconsin may drop when drugs only show sub-optimal efficacy. Overall, the study indicates that the precision of FECRT is affected by the methodology of FEC, and that the level of egg excretion should be considered in the final interpretation of the FECRT. However, more comprehensive studies are required to provide more insights into the complex interplay of factors inherent to study design (sample size and FEC method) and host-parasite interactions (level of egg excretion and aggregation across the host population)
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
A Short Term Scientific Mission at Ghent University for the development of the Mini-FLOTAC Automated System
No full textDispelling 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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