1,720,958 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
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
Untersuchungen zur Durchblutungsmessung (Perfusion) am Herzen mittels der Magnetresonanztomographie
No full textDie kontrastmittelverstärkte myokardiale Perfusionsmessung am Herzen mittels Magnetresonanztomographie (MRT) erlaubt eine Quantifizierung des myokardialen Blutflusses (MBF) zur Diagnose der koronaren Herzkrankheit. Diese Methode nimmt wiederholt Schichtbilder vom Herzen während der Anflutung von Kontrastmittel auf und berechnet aus dieser Bildserie den MBF mittels eines tracerkinetischen Modells. Ein Hauptproblem dieser Methode ist eine während der Messung auftretende Verschiebung des Herzens gegenüber der Messschicht, die z.B. durch Atmung verursacht wird. Diese Herzbewegung führt zu einer fehlerhaften Abtastung der Kontrastmittel-Anflutung und damit zu einem falschen MBF-Wert, da sie nach der Messung nicht mehr kompensiert werden kann. In der klinischen Diagnostik werden daher die Perfusionsmessungen während der Unterdrückung des Atems durchgeführt, die aber bei vielen Patienten wegen der langen Messdauer aufgrund von Luftnot abgebrochen werden müssen.
Das Ziel dieser Arbeit war die Entwicklung einer Methode zur Kompensation dieser Herzbewegung durch Nachführen der Messschicht während der Messung. Dazu wurde die Navigatortechnik zur Bewegungsdetektion an die Erfordernisse der Perfusionsmessung adaptiert und in die Messmethode integriert. Anschließend konnte in einer Studie an gesunden Hausschweinen die signifikante Verbesserung der berechneten MBF-Werte gegenüber Messungen ohne Schichtnachführung gezeigt werden. Sie waren sowohl während künstlicher Beatmung als auch während der Atemunterdrückung mit den Werten des klinischen Goldstandards der PET-basierten MBF-Messung vergleichbar. Es muss in weiteren Studien untersucht werden, ob diese vielversprechenden Ergebnisse gerade für die Messungen mit Atembewegung in den klinischen Alltag übertragbar sind und damit einen Gewinn an Aussagekraft der Perfusionsmessung und an Komfort für den untersuchten Patienten bedeuten.
Da in der Tierstudie nacheinander mehrere kontrastmittelverstärkte Perfusionsmessungen für den direkten Methodenvergleich unter verschiedenen physiologischen Bedingungen durchgeführt wurden, musste auch der Einfluss von residualem Kontrastmittel aus vorangegangenen Applikationen von Kontrastmittel auf die MBF-Quantifizierung betrachtet werden. Dieser Einfluss konnte mit einer Weiterentwicklung der Auswertung erfolgreich kompensiert werden. Dies hat auch Auswirkung auf die Berechnung der in der klinischen Diagnostik wichtigen myokardialen Perfusionsreserve. Sie erlaubt eine Aussage über die Schwere der koronaren Herzkrankheit und ist ebenfalls von residualem Kontrastmittel beeinflusst, da sie das Verhältnis aus zwei MBF-Messungen unter Ruhe und Stress beschreibt.
Schlussfolgernd konnte somit in dieser Arbeit gezeigt werden, dass beide vorgestellten Techniken, zum einen die Nachführung der Messschicht und zum anderen die Kompensation des Einflusses von residualem Kontrastmittel, deutlich die Aussagekraft der quantitativen Durchblutungsmessung am Herzen mittels der dynamischen MRT verbessern.First-pass perfusion magnetic resonance imaging (pMRI) allows diagnosis of coronary heart disease by myocardial blood flow (MBF) quantification. This method acquires images of slices of the heart during first-pass of contrast agent, and MBF is quantified from this image serie using a tracer-kinetic model.
A main drawback of this method is heart movement through the measured slice, i.e. due to breathing. This temporal dislocation of the heart is not adjustable after the measurement and bias detection of contrast agent distribution, which leads to an erroneous MBF. To avoid this heart movement clinical first-pass pMRI is performed during a long breathhold, which many patients break up. This leads to impossible MBF quantification for these measurements.
The aim of this work was the development of a correction method for heart movement during first-pass pMRI. Therefore, a navigator technique with prospective slice tracking (PST) was adapted to first-pass pMRI. In a study performed within healthy pigs MBF quantification show a significant improvement compared to measurements without PST. MBF values measured with PST during artificial breathing as well as during breathhold were comparable to the clinical gold standard based on measurements with positron emission tomography. These promising results have to be testet further in clinical settings for its benefit in validity and patient comfort.
For method comparison several first-pass pMRI were performed consecutively during several physiological conditions. Therefore, the influence of residual contrast agent enriched from previous administrations on the MBF quantification was investigated and a further technical development was included into the MBF quantification, which successfully corrected this influence of residual contrast agent. This technique improves also the calculation of the myocardial perfusion reserve which is important for clinical diagnosis of severity of coronary heart disease. The myocardial perfusion reserve is also biased by residual contrast agent, because it is the ratio between two MBF values, one measured during stress and the other measured in rest.
In conclusion, both techniques described in this work, the prospective slice tracking technique and the correction for residual contrast agent, improves the validity of myocardial first-pass pMRI significantly.81 Blätte
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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