1,720,956 research outputs found
Molecular epidemiology of Chlamydia trachomatis: valuation, implementation and development of high resolution genotyping
No full textDetailed molecular epidemiology of Chlamydia trachomatis in the population of Southampton attending the genitourinary medicine clinic in 2012-13 reveals the presence of long established genotypes and transitory sexual networks
No full textChlamydia trachomatis is the most common sexually transmitted infection (STI) in England. Our objective was to perform a detailed survey of the molecular epidemiology of C. trachomatis in the population of Southampton UK attending the genitourinary medicine clinic (GUM) to seek evidence of sexual network activity. Our hypothesis was that certain genotypes can be associated with specific demographic determinants. 380 positive samples were collected from 375 C. trachomatis positive GUM attendees out of the 3118 who consented to be part of the survey. 302 of the positive samples were fully genotyped. All six of the predominant genotypes possessed ompA locus type E. One ward of Southampton known to contain a large proportion of students had a different profile of genotypes compared to other areas of the city. Some genotypes appeared embedded in the city population whilst others appeared transient. Predominant circulating genotypes remain stable within a city population whereas others are sporadic. Sexual networks could be inferred but not conclusively identified using the data from this survey.</p
Highly diverse MLVA-ompA genotypes of rectal Chlamydia trachomatis among men who have sex with men in Brighton, UK and evidence for an HIV-related sexual network.
Get PDFObjectives: In this prospective study, we aimed to determine the distribution of genotypes by multilocus variable number tandem repeat (VNTR) analysis plus analysis of the ompA gene (MLVA-ompA) of rectal Chlamydia trachomatis among men who have sex with men (MSM) attending Brighton Genitourinary Medicine (GUM) Clinic and to examine any correlations with clinical variables, including HIV status, and to isolate rectal C. trachomatis cultures maximising the possibility of obtaining complete genotyping data.Methods: Samples were assigned genotypes by PCR and sequencing of the markers of the MLVA-ompA genotyping system. Rectal C. trachomatis was isolated in cell culture using McCoy cells. Data regarding demographics, HIV status, rectal symptoms and history of sexually transmitted infections, including C. trachomatis, were collected.Results: 1809 MSM attending the clinic between October 2011 and January 2013 took part in the study, 112 (6.2%) of whom had rectal samples that tested positive for C. trachomatis. 85/112 (75.9%) C. trachomatis-positive rectal samples were assigned 66 different genotypes. Two distinct genotype subclusters were identified: subcluster 1 consisted of more HIV-negative men than subcluster 2 (p=0.025), and the MLVA-ompA genotypes in these subclusters reflected this. Isolates were successfully cultured from 37 of the 112 specimens, from which 27 otherwise unobtainable (from direct PCR) MLVA-ompA genotypes were gained.Conclusions: The most prevalent genotypes were G, E and D representing some overlap with the heterosexual distribution in UK. Subcluster 1 consisted of more ‘heterosexual genotypes’ and significantly more HIV-negative men than subcluster 2, associated with ‘MSM genotypes’. There was a higher diversity of C. trachomatis strains among MSM in Brighton than observed in other cities.<br/
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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