1,720,965 research outputs found
The association between genital mycoplasmas and bacterial vaginosis in pregnant women with or without genital symptoms
Get PDFDissertation (MSc)--University of Pretoria, 2018.Bacterial vaginosis (BV) and genital mycoplasmas are infections of the reproductive tract that play important roles in maternal and foetal health. Genital mycoplasmas include Mycoplasma genitalium, M. hominis, Ureaplasma parvum and U. urealyticum. Infection may increase a woman’s susceptibility to infection with the human immunodeficiency virus (HIV). Bacterial vaginosis associated bacteria may form biofilms that are responsible for antimicrobial resistance and about 30% of affected women will relapse within three months of treatment. Genital mycoplasmas are prone to develop point mutations, which are responsible for increased antimicrobial resistance. Infections with these bacteria become prominent during pregnancy as infection may lead to infertility and foetal death. The purpose of the study was to determine the association between genital mycoplasmas and BV in pregnant women. Pregnant women attending the antenatal and Maternal and Foetal Unit (MAFU) clinics of a tertiary academic hospital in Pretoria, South Africa were included in the study. Self-collected vaginal swab specimens were obtained from consenting women older than 18 years of age. With the aid of microscopy, the Nugent scoring system was used to diagnose BV. Genital mycoplasmas were cultured on A2 agar and were diagnosed and speciated with a multiplex polymerase chain reaction (mPCR) assay. In addition, genital mycoplasmas were diagnosed and the antimicrobial susceptibility profiles determined with the Mycofast Revolution assay. A quantitative real-time polymerase chain reaction (qPCR) was employed to quantify the BV associated bacteria Atopobium vaginae and Gardnerella vaginalis. The prevalence of BV in this study was found to be 17.7% in 220 recruited pregnant women. Threshold concentrations between 106 to 107 copies/reaction of A. vaginae and G. vaginalis were found to be the best predictors of BV. Genital mycoplasmas were poorly recovered from A2 agar media, which had a contamination rate of 54.9%. An mPCR assay revealed that genital mycoplasmas were prevalent in 2.3% to 71.4% of specimens with U. parvum being the most prevalent species. The resistance of Ureaplasma species to tetracycline and erythromycin was 73% and 80%, respectively. Minor resistance to the fluoroquinolones, levofloxacin and moxifloxacin was recorded. This study found that only the genital mycoplasmas, namely M. hominis and U. parvum, were significantly associated with BV, while M. hominis was also significantly isolated from HIV positive women. This study found that there is an association between BV and genital mycoplasmas. The high prevalence of BV and genital mycoplasmas suggests that current management and/or intervention strategies are insufficient. Bacterial vaginosis associated bacteria can form a polymicrobial biofilm, which confer protection against antimicrobial agents and host immune responses. These biofilms are present on genital sites like the endometrium, which is located close to the amniotic membranes, posing health risks for the pregnancy. Future research must focus on the study of in vitro BV biofilm models and effective treatment strategies to minimise antimicrobial resistance. In the meantime, low-cost point-of-care (POC) tests that can accurately diagnose RTIs are needed to prevent excessive and unnecessary administration of antimicrobial agents and improve maternal and foetal health in the South African health care system.Medical MicrobiologyMScUnrestricte
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
Emerg Infect Dis
Get PDFWe detected Chlamydia trachomatis biovar L2 in vaginal swab specimens of 7 women with vaginal discharge in South Africa. Whole-genome sequencing directly from clinical specimens identified a closely related cluster of strains. The clinical role of this infection in the context of syndromic management should be clarified
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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