1,720,972 research outputs found
Molecular profiling of acute chorioamnionitis-affected placentas : insights into genomic variation underlying a common preterm birth condition
No full textAcute chorioamnionitis (aCA), a preterm birth (PTB) associated inflammatory condition, can have adverse effects on the health of the baby. This condition is characterized by inflammatory lesions in the fetal membranes and can also involve the chorionic plate in the placenta. Histologic examination of the placenta is the gold standard for diagnosing aCA, but is only possible after delivery; thus, this method is not suitable for prenatal diagnosis of aCA. This necessitates the development of non-invasive biomarkers to allow effective management of the disease and hence, reduce the incidence of PTB. Additionally, genetic variation in immune-system genes may contribute to the placenta’s inflammatory responses, thus influencing susceptibility to aCA.
The overarching objective of this dissertation is to understand how genetic, epigenetic, and miRNA variation in the placenta is associated with the disruption of immune balance in aCA. To achieve this, I first examined the association of single nucleotide polymorphisms (SNPs) in innate immune system genes and aCA status. I observed that differences in IL6 (rs1800796) placental allele frequencies were associated with the presence of aCA. Further, I showed the IL6 SNP may regulate IL6 gene expression and DNA methylation (DNAme) in the placenta, and alter disease risk to aCA. Secondly, using the Illumina HumanMethylation850 BeadChip, I characterized epigenetic variation associated with aCA in placenta and fetal membranes. Specifically, I observed that aCA-affected placentas showed a unique DNAme profile that may reflect an increase in immune cell number as a response to inflammation and/or represent activation of the innate immune response in the placenta. Lastly, I investigated whether altered miRNA profiles were associated with aCA-affected placentas. Expression was quantified for six inflammation-related miRNAs using quantitative real-time PCR. I observed that expression of miR-518b and miR-338-3p were differentially expressed in aCA-affected placentas. I also showed that miR-518b expression in placenta was associated with IL6 (rs1800796) genotype, where carriers of the C allele exhibited decreased miR-518b expression compared to the carriers of the G allele. In summary, this research uniquely investigated genetic alterations, DNAme, and miRNA expression patterns in aCA-affected placentas, adding insights into the processes likely impacting immune function during aCA.Medicine, Faculty ofMedical Genetics, Department ofGraduat
LOCALIZING GENETIC ELEMENTS ASSOCIATED WITH REPRODUCTIVE PERFORMANCE IN MINK USING A SEQUENCE-BASED SNP PANEL
No full textReproductive performance is a multifactorial trait which is affected by genetic, physiological and environmental factors. This study aimed at identification of genetic elements associated with fertility in mink females using the candidate gene approach, and was performed in a population of Standard Black mink maintained between 2009 and 2013. Based on dietary treatment, this population was analysed independently as two categories: Control (CTRL) and Moderate Diet Restriction (MDR). Irrespective of the analytical approaches used, twelve genes in the MDR group and ten genes in the CTRL group showed significant associations with fertility, at probabilities of less than or equal to 0.05. The results of this research allowed a better understanding of the role of genetic elements in fine-tuning the seasonally regulated reproductive functions in female mink
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
Advancing pediatric and longitudinal DNA methylation studies with CellsPickMe, an integrated blood cell deconvolution method
No full textProspective birth cohorts offer the potential to interrogate the relation between early life environment and embedded biological processes such as DNA methylation (DNAme). These association studies are frequently conducted in the context of blood, a heterogeneous tissue composed of diverse cell types. Accounting for this cellular heterogeneity across samples is essential, as it is a main contributor to inter-individual DNAme variation. Integrated blood cell deconvolution of pediatric and longitudinal birth cohorts poses a major challenge, as existing methods fail to account for the distinct cell population shift between birth and adolescence. In this paper, we critically evaluated the reference-based deconvolution procedure and optimized its prediction accuracy for longitudinal birth cohorts using DNAme data from the Canadian Healthy Infant Longitudinal Development (CHILD) cohort. The optimized algorithm, CellsPickMe, integrates cord and adult references and picks DNAme features for each population of cells with machine learning algorithms. It demonstrated improved deconvolution accuracy in cord, pediatric, and adult blood samples compared to existing benchmark methods. CellsPickMe supports blood cell deconvolution across early developmental periods under a single framework, enabling cross-time-point integration of longitudinal DNAme studies. Given the increased resolution of cell populations predicted by CellsPickMe, this R package empowers researchers to explore immune system dynamics using DNAme data in population studies across the life course
Dispelling 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
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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