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Echocardiography nomograms in Black South African neonates
No full textSubmitted in the fulfilment of requirements of the Masters of Health Sciences degree (Clinical Technology) at Durban University of Technology, 2020.The subspecialty of Paediatric cardiology has adapted and refined techniques adopted from adult cardiology to manage children, (Mahle, Blaine and Silverman 2009:33). Although a quantitative evaluation of cardiac chambers, valve annulus and great vessel dimensions in paediatric echocardiography is important, nomograms for these structures are limited. Several studies have already provided normal values in the paediatric population that represent most populations of the world but there is lack of data that has been published in sub-Saharan Africans, (Lemmer et al. 2014:1 and Roge et al. 1978:285).
AIMS AND OBJECTIVES
Aim: To establish reliable echocardiography nomograms for cardiac chambers, valve annuli, great vessels and thymus dimensions in the Black South African neonatal population. Objectives: To determine normal values of cardiac chambers, valve annuli, great vessel and thymus dimensions. To determine inter-observer variability. To determine the effect of confounding factors such as gender and type of delivery on the measurements obtained.
METHODS
This is a descriptive, cross-sectional study evaluating cardiac chambers, valve annuli, thymus and great vessel dimensions in 386 African neonates with normal hearts using echocardiography. The study data consists of two arms, a retrospective arm utilizing echocardiographic data acquired during a previous study entitled “To assess the accuracy of pulse oximetry screening as a tool to detect critical congenital heart disease in asymptomatic newborns” and a prospective arm.
INCLUSION CRITERIA: Healthy newborns at an age of 12 hours or more before discharge. Patients without any heart disease, with a “normal heart” by echocardiography excluding hemodynamically non-significant patent ductus arteriosus and patent foramen ovale. Black South African patients. Full term babies delivered by caesarian section and normal vertex.
EXCLUSION CRITERIA: Patients less than 12 hours from birth. Patients with known structural heart lesion. Patients who are non- black South Africans. Pre-term neonates.
DATA COLLECTION AND ANALYSIS: Collected data was entered on excel spreadsheet and analyzed using excel, XLSTAT 2019 and STATISTICA version 13.5.0 statistical packages for analysis by the principal researcher (Nondumiso M. Hadebe). A p-value of less than 0.05 and significance level of 95% was considered statistically significant. A professional biostatistician at University of the Witwatersrand was consulted for assistance in data analysis. Homoscedasticity and heteroscedasticity were tested using Shapiro-Wilk, Kolmogorov-Smirnov, Breusch-Pagan and White tests. The inter-observer variability was tested with intraclass correlation coefficient using Pearson’s correlation coefficient to detect bias. Weight was used to express measurements to body size and to predict mean values of each echocardiographic measurement that were expressed as Z-scores.
RESULTS
A total of 386 patients from both arms were enrolled with almost equal gender distribution with a slightly higher percentage of females, 191 (49%) were males and 195 (51%) were females. The study involved neonates born through normal vaginal delivery (NVD) and through caesarian section (C/S) which showed equal distribution. The assumption of normality was tested which showed most measurements being homoscedastic. Heteroscedasticity was tested which showed most measurements to be homoscedastic. Effects of confounding factors were tested which showed that body weight has a significant effect on all cardiovascular dimension measurements. Mode of Delivery (MOD) had a significant effect on the size of atrioventricular valve, pulmonary artery and pulmonary artery branch measurements. Gender and BSA had no significant effect on most measurements but with some significant effect on a few measurements. There was no significant effects seen for body length (BL) and gestational age (GA). The echocardiography measurements of 168 patients were used to test for inter-observer variability which showed a strong correlation on most measurements. Birth weight was used to express cardiac measurements to body size. All echocardiographic measurements were grouped into 3 categories of weight and are presented as mean and +/-3 SD. Z-scores and its boundaries for all measurements is presented graphically. This study showed slightly higher dimensions to previous studies from other centres.
CONCLUSION
This study presents nomograms that are reliable because they were acquired from healthy neonates using current recommendations by the American Society of Echocardiography, (Lopez et al. 2010: 465-495). Weight showed significant potential as a confounding factor and as an independent variable for data normalization. This study showed slightly higher dimensions to previous studies emphasizing that it is important to develop and use regional nomograms because of the effects of environmental, economic and social factors of the region. This study covered the gap of knowledge on cardiac chamber, valve annuli, and arterial and thymus dimensions in the neonatal age group. Further studies are required to reinforce these findings that will also involve the right cardiac dimensions. More studies are needed based on African paediatric populations including the all paediatric age groups (0-18 years).
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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