1,720,984 research outputs found
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
Acute heart failure: Scottish temporal trends in hospitalisation, outcomes and clinical application of natriuretic peptides
No full textAcute heart failure (AHF) is common and is a major cause of morbidity and mortality in the UK. The prevalence of heart failure is estimated at 1-2% and is increasing with our ageing population. Available data from several countries suggests there may have been a decline in both the incidence of and mortality from AHF in recent years. However, these trends have not been universally identified and there has been relatively sparse reporting of trends across key subgroups as well as outcomes data. Timely diagnosis of acute heart failure is essential to improving outcomes and natriuretic peptides (NPs) are the recommended biomarkers for diagnosis of AHF. NP concentrations are known to be altered by patient factors, such as age, renal impairment and arrhythmia, which are common in populations with heart failure. The impact of these patient factors on the performance of guideline-recommended thresholds is unknown. Whilst having reasonable rule-out value, current guideline thresholds have limited specificity suggesting substantial potential for over- investigation, misdiagnosis and inappropriate initiation of treatment.
The principal aims of my thesis were three-fold. First, to examine the national temporal trends in the incidence and outcomes for AHF hospitalisations in Scotland, including important sub-groups of interest. Second, to evaluate the performance of the current guideline-recommended natriuretic peptides thresholds (N-terminal-pro-B-type natriuretic peptide (NT-proBNP) and B-type natriuretic peptide (BNP)) in suspected AHF, including key sub-groups. Lastly, to explore the potential to improve the diagnostic performance of NT-proBNP by applying novel variable thresholds across different subgroups.
Our analysis of temporal trends (1990-2014) of the Scottish population for incident hospitalised AHF using a national individual-level linkage approach showed that incident acute hospitalised heart failure has reduced over the study period. This was apparent across all age groups, both sexes and all socioeconomic groups. This reduction was most marked in the oldest age group and lowest socioeconomic group. The case fatality rate following acute heart failure declined modestly over the 25-year study period but remained higher in socially deprived groups and there was a slight rise in the incidence of rehospitalisation with heart failure. The reduction in mortality rate over time in older patients was similar to that observed in younger patients.
Our individual patient-level meta-analysis showed that the current thresholds to rule out AHF perform fairly well for NT-proBNP and BNP, and are largely in keeping with reported meta-estimates in the literature. However, the overall negative predictive value (NPV) thresholds masks major heterogeneity across important subgroups, such as older age, history of ischaemic heart disease, atrial fibrillation, renal impairment and, most of all, prior heart failure. The rule-in threshold performance for both NT- proBNP and BNP using a single threshold is modest at best, with a false positive rate of between 30 and 40%. Applying higher separate rule in threshold results in 20% indeterminate results (AHF diagnosis uncertain) but with less false positive tests, only 25%. Most notably, patients without prior heart failure had a positive predictive value (PPV) of only around 50% with a single guideline-recommended threshold (>300pg/mL) approach with NTproBNP. The PPV in this group improved incrementally with the single optimised and the separate rule in optimised threshold, to 65% and 73% respectively. Patients without a history of heart failure stand to gain most from diagnosis and treatment of heart failure, but current thresholds appear to underserve arguably the important subgroup. Therefore, deriving distinct optimal thresholds for patients with and without a prior diagnosis of heart failure - and potentially other key subgroups - has the potential to improve the practical clinical utility of NT-proBNP testing.
Overall, my thesis findings suggest that improvements in the prevention and treatment of heart failure have had progressive and sustained effects on the incident AHF hospitalisation and outcomes at the population and subgroup level although the overall prognosis remains poor. Whilst these temporal trends are informative, more granular data, such as prescribing data, will be key to understand the cause for the disparity in outcomes across key groups. However, this analysis demonstrates that using Scottish health data, we can appreciate longitudinal trends in the whole population and sub- groups but doing so as close to real-time as possible with more granular data on treatments would yield analysis that has the potential to influence and improve outcomes.
We carried out the first individual patient level meta-analysis of NP testings in AHF to assess optimal thresholds to rule-in and rule-out AHF across key subgroups. This showed that whilst having overall reasonable performance, there is significant heterogeneity in subgroups. Our analysis of the sub-population of patients with and without heart failure history with NT-proBNP suggests that there is scope to optimise the rule-out and rule-in thresholds in patients without a prior heart failure history. Our subsequent derivation and publication of our decision tool for AHF suggests there may be additional gains over and above applying an optimal rule-in and rule-out NP threshold alone. However, these findings need real-world evaluation to support its entry into clinical practice and we have proposed a study to progress this further
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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