1,720,957 research outputs found
The Impacts of Adipose Tissue and the Gut Microbiome on Diabetes Risk among African-Caribbean Men
No full textType 2 diabetes (T2D) and its complications are increasing in prevalence and burden worldwide. Caribbean rates of T2D rival those of the United States, and mortality from T2D is exceptionally higher. The study of novel T2D risk factors, such as adipose tissue (AT) radiodensity, AT distribution, and the intestinal microbiome, yield greater insights into T2D pathophysiology and can inform targeted interventions. However, individuals of African ancestry, who have a higher burden of T2D compared to Caucasian counterparts, are underrepresented in this research. Thus, this dissertation fills the gaps by investigating associations of AT radiodensity, body composition, and the intestinal microbiome with T2D in a cohort of African Caribbean men from Tobago, Trinidad and Tobago.
The first dissertation paper investigates associations between AT radiodensity in the abdomen (visceral [VAT] and subcutaneous [SAT]) and thigh (intermuscular [IMAT]) with glucose, insulin, and insulin resistance. We demonstrate that lower radiodensity in any AT (indicating greater tissue lipid accumulation) was associated with higher insulin and insulin resistance, with independent contributions from thigh IMAT. The second dissertation paper models the associations of both AT and muscle from the abdomen and thigh with T2D. We report that abdominal SAT (but not VAT) was positively associated, and thigh muscle negatively associated, with higher odds of T2D. The third dissertation paper examines associations of the intestinal microbiome with sociodemographic, lifestyle, body composition, and T2D measures. We identified sociodemographic factors as a main driver of microbial clustering, and several lifestyle and body composition measures as being differentially associated with taxonomic units, thus informing future prediction modeling of the microbiome with T2D.
These findings have significant public health implications. Our results somewhat differ from those reported in predominantly Caucasian cohorts, highlighting the importance of including racial/ethnic minorities in novel risk factor research. These papers also provide important methodological work, informing how body composition analyses are performed. Finally, this research produced the first nutritional and microbiome databases in Tobago, which can aid future T2D research. Taken together, information from this dissertation can be leveraged to inform future observational and interventional studies in T2D prevention, both in the Caribbean and worldwide
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
Association of lipopolysaccharide-binding protein with increases in liver fat in African ancestry men
Get PDFNon-alcoholic fatty liver disease (NAFLD) is a disease with increasing prevalence worldwide, especially in developed countries. While the etiology of NAFLD is complex, the intestinal microbiome may play a role in the development of liver steatosis through bacterial-induced inflammation. Lipopolysaccharide-binding protein (LBP) is an acute-phase protein produced by the liver and which facilitates bacterial-induced inflammation. LBP levels in the serum tend to be low but are raised during infection or in the presence of bacterial components; thus, levels of LBP are considered to be reflective of bacterial-induced inflammation. While the association of LBP with NAFLD has been investigated in cross-sectional studies, no longitudinal studies have been done to determine if LBP levels are associated with liver fat accumulation. Furthermore, no studies have been performed which show the heritability of LBP levels, which may affect susceptibility to the inflammatory response. Elucidation of the role of LBP in NAFLD can provide insights into the etiology of NAFLD and provide a mechanistic link between the intestinal microbiome and liver fat accumulation, yielding public health importance for the understanding and treatment of NAFLD. This study is the first longitudinal study to look at the associations of LBP with the development of steatosis and it is the first study to determine the heritability of LBP in any population, thus supplying novel information on the associations between LBP and liver fat accumulation.
A large family-based study of African ancestry men and women (N = 470) and a large prospective cohort study of African ancestry men (N = 2853) from Tobago were used for this study. LBP was measured in all individuals in the family study. Heritability analyses were performed using SOLAR. In the prospective cohort study, LBP levels were measured at baseline visit (2004-2007), and liver fat was assessed at the follow-up visit (2013-2016, ~10 years later) by computerized tomography (CT) scan, with an overlap of 204 men having both LBP and liver CT completed. Associations were assessed using Spearman correlations and regression analyses. LBP levels in the families were found to have no residual heritability, suggesting that LBP might be entirely environmentally determined in this population. In the prospective cohort, LBP was associated with liver fat infiltration in multivariable analyses which included BMI (p = 0.0469), but not in models which instead included waist circumference. In conclusion, we determined that among African ancestry individuals, LBP levels are completely environmentally determined and that levels may be associated with increases in liver fat accumulation
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
