1,721,005 research outputs found
Elucidating mechanisms that drive changes in the composition of the human vaginal microbiome
No full textThe influence of the vaginal microbiome on women’s relative risk to disease and reproductive complications has been well documented. In the last decade, extensive cross-sectional and longitudinal studies have shown that many types of vaginal communities are found in healthy women, and that the composition of these communities can change over a matter of days. Currently, we have a poor understanding of the factors that cause compositional differences observed between women and temporal changes within women. Thus, the goal of my work is to fill this gap in knowledge. In the opening chapter, I briefly review what is known about the composition of vaginal communities in reproductive age women. Due to the positive association with Lactobacillus in the vagina and vaginal health, I narrowed the focus on species within this genus. Additionally, I discuss two host factors, namely estrogen and glycogen that have been associated with changes in the abundances of lactobacilli over a woman’s lifespan. Next, I characterized the composition of vaginal bacterial communities in a cohort of black adolescent women based on differences in the total abundances of Lactobacillus. Then I explore the relationships between estrogen, glycogen, stress, and vaginal community composition. I confirmed previous findings that glycogen levels are associated with high abundances of lactobacilli in vaginal communities. I also report that estradiol levels do not correlate with vaginal glycogen measurements, nor vaginal community composition. This finding is noteworthy as it suggests the association between estrogen, glycogen, and vaginal lactobacilli is more complex than previously thought. This study addresses potential developmental factors that influence the composition of vaginal communities and provides new insights into the kinds of communities that are present among black adolescent women. In my third chapter, I differentiated putative amylases in the human vagina, which likely break down glycogen into simpler sugars that are fermented by vaginal lactobacilli. For this work, I designed a pilot study to collect vaginal samples from 23 reproductive age women. Using metagenomics and proteomics, I identified putative amylases expressed in vaginal fluids that mapped to the metagenomes of vaginal bacteria. I report novel findings that there are multiple amylases in the human vagina that are produced by both the host and bacteria within the community. Finally, I explore the transition from pregnancy to postpartum in a cohort of 48 women. I document findings that are consistent with previous studies that showed the composition of vaginal communities changes from pregnancy to postpartum and is marked by reduced abundances of Lactobacillus and increased alpha diversity. I report new findings of host-associated compounds that are significantly associated with the changes observed during postpartum.doctoral, Ph.D., Bioinformatics & Computational Biology -- University of Idaho - College of Graduate Studies, 2020-0
Vaginal microbial communities do not preclude colonization by Staphylococcus aureus with the gene for toxic shock syndrome toxin 1 (TSST-1)
No full textThe majority of cells in the human body are bacterial; most of which are commensal, however, some species are pathogenic. One question facing microbiology is how do different indigenous microbial communities affect health. It is known that there are many different microbial community compositions present in the vaginas of healthy women and they may provide different levels of protection from pathogenic organisms. We test the colonization by the pathogen Staphylococcus aureus encoding toxic shock syndrome toxin 1. To test this we examined the community compositions of the vaginas otherwise healthy women colonized with S. aureus and compared these communities to those not colonized. We were unable to demonstrate an association between the presence of the pathogen S. aureus and the community structure which suggests no difference in the ability of the community to exclude the pathogen.Thesis (M.S.,Bioinformatics and Computational Biology ) -- University of Idaho, 200
Hydrodynamic cavitation : effects of cavitation on inactivation of Escherichia coli (E.coli)
No full textM.S
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
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