1,720,958 research outputs found
Das Bildgeführte Präzisionsbestrahlungsgerät für Kleintiere (SAIGRT): von der Entwicklung bis zur Praxisreife
Get PDFDas entwickelte Bildgeführte Präzisionsbestrahlungsgerät für Kleintiere (engl. Small Animal Image-Guided Radiation Therapy – SAIGRT) dient der schnellen, hochauflösenden Röntgenbildgebung und präzisen, konformalen Bestrahlung von Kleintieren im Rahmen präklinischer in-vivo Experimente für die translationale Krebsforschung. Speziell programmierte Softwares zur Gerätesteuerung sowie zur Bildkorrektur- und Bildrekonstruktion auf dem zentralen leistungsfähigen Arbeitsplatz-PC stellen alle Gerätefunktionen zur Verfügung und ermöglichen durch automatisierte Abläufe und intuitive grafische Nutzeroberflächen eine einfache, sichere Bedienung. Für die Bestrahlungsplanung wird eine vollwertige, aus der humanen klinischen Strahlentherapie adaptierte 3D-Bestrahlungsplanungssoftware eingesetzt, die etablierte Werkzeuge für den Transfer und die Koregistrierung multimodaler Bilddaten, die Konturierung und Segmentierung von Zielvolumina und Risikoorganen sowie die Erstellung und Validierung von Bestrahlungsplänen enthält. Die resultierende Dosisverteilung wird darin basierend auf dem individuellen CT-Datensatz des Versuchstieres und einem auf das SAIGRT angepassten Maschinenmodell mittels eines Monte-Carlo-Algorithmus exakt und realitätsnah simuliert. Durch geometrische Kalibrierungen und vielfältige Basisdatenmessungen für die Bildgebung und Bestrahlung im Rahmen der Gerätekommissionierung ist eine Zielgenauigkeit von ca. ±0,1 mm mit hoher geometrischer Abbildungstreue und guter Bildqualität bei Bildgebungsdosen vergleichbar denen klinischer Radiografie- und CT-Geräte möglich. Die Dosisverteilung zur Bestrahlung der Versuchstiere spiegelt bei der definierten Strahlungsqualität größenskaliert die humane Strahlentherapie mit hochenergetischer Photonenstrahlung von klinischen Linearbeschleunigern wider. Ein umfassendes Qualitätssicherungsprogramm bestehend aus regelmäßiger Wartung und wiederkehrenden Konstanzprüfungen der Bildgebung und Bestrahlung sichert dauerhaft den technisch einwandfreien Zustand und die ordnungsgemäße Verfügbarkeit aller Gerätefunktionen in gleichbleibender Güte. Das SAIGRT ist somit nachweislich geeignet, bildgeführte Bestrahlungen mit einem Ablauf analog dem einer modernen klinischen Strahlentherapie am Menschen in präklinischen in-vivo Experimenten präzise an Kleintieren zu applizieren. Es leistet dadurch einen essentiellen Beitrag zur translationalen Krebsforschung in Dresden, indem die klinische Situation realistischer modelliert und so potenziell die Übertragbarkeit der Ergebnisse auf Krebspatienten verbessert werden kann.The Small Animal Image-Guided Radiation Therapy (SAIGRT) platform facilitates fast, high resolution X-ray imaging and precise, conformal irradiation of small animals in preclinical in-vivo experiments for translational cancer research. Dedicated software for device control as well as image correction and reconstruction on a central high performance PC provide all device functions and allow simple and safe operation by automated procedures and intuitive graphical user interfaces. A fully 3D treatment planning software adapted from human clinical radiation therapy is used for treatment planning, containing established tools and methods for the transfer and registration of multimodality imaging data, contouring and segmentation of target volumes and organs at risk as well as creation and evaluation of treatment plans. Based on an individual CT scan of the small animal and a machine model adapted for the SAIGRT, the resulting dose distribution is simulated by a Monte-Carlo algorithm in a precise and realistic manner. Geometrical calibrations as well as manifold basic data measurements for X-ray imaging and irradiation during commissioning resulted in a targeting and imaging accuracy of about ±0.1 mm, a correct representation of imaging geometry and a good image quality with imaging doses comparable with those of clinical radiography and CT systems. Dose distribution of the defined beam quality used for irradiation of small animals reflects a downsized human radiation therapy using high energy photon beams of clinical linear accelerators. A comprehensive quality assurance program comprising regular maintenance and periodic constancy tests of X-ray imaging and irradiation ensures permanent technically perfect condition and proper availability of all implemented functions in a stable high quality. The SAIGRT platform is feasible for image-guided irradiations precisely applied to small animals in preclinical in-vivo experiments using a workflow of modern human radiation oncology. Thus, it significantly contributes to translational cancer research by more realistic modelling the clinical situation and potentially brings the results closer to their clinical implementation
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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