1,720,953 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
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
Quantifizierung der Fusion von CD63-positiven Vesikeln durch murine cytotoxische T- Lymphozyten mittels Echtzeit-Mikroskopie
Get PDFBei der Interaktion einer cytotoxischen T-Zelle (CTL) mit einer virusbefallenen Zelle oder Krebszelle wird die CTL über den T-Zellrezeptor (engl. t-cell receptor, TCR) und den Ko-Rezeptor CD8 stimuliert. Zwischen CTL und Zielzelle (engl. target cell, TC) wird eine Immunsynapse (IS) ausgebildet und es kommt zu einer Polarisation der cytotoxischen Granula (CGs) zur IS. Schließlich fusionieren CGs an der IS mit Freisetzung ihres cytotoxischen Inhalts wie beispielsweise Perforin und Granzyme, um die TC zu zerstören. Es gibt zwei Klassen von CGs: „Single core granules“ (SCGs), die lösliche cytotoxische Proteine freisetzen, und „Multi core granules“ (MCGs), die supramolekulare Angriffpartikel (SMAPs) und teilweise auch Exosomen freisetzen. In den letzten Jahren wurde vermehrt berichtet, dass CTL mittels Freisetzung von extrazellulären Vesikeln (EVs) wie beispielsweise Exosomen einen weiteren Weg zur Kommunikation und zur Cytotoxizität nutzen. Bei Exosomen handelt es sich um EVs mit einer Größe von 30 -100 nm, die durch Fusion von multivesikulären Körpern (engl. multivesicular bodies, MVBs) mit der Plasmamembran freigesetzt werden. Wir wollten herausfinden, ob CD63 ein geeigneter Marker für MVBs und Exosomen von CTL ist und ob CTL Exosomen an der IS freisetzen. Zunächst untersuchten wir in murinen CTL die Lokalisation der Exosomenmarker CD63 und CD81, welche mit den fluoreszierenden Proteinen pHuji und pHluorin gekennzeichnet waren, in Bezug auf Granzym B (GzmB) als Marker für CGs mittels „Structured illumination“-Mikroskopie (SIM). Wir stellten eine signifikant höhere Ko-Lokalisation zwischen CD63 und GzmB als zwischen CD63 und CD81 oder CD81 und GzmB fest. Aufgrund der interessanten Ko-Lokalisation zwischen CD63 und GzmB entschieden wir uns dafür die Fusion CD63-pHuji positiver Vesikel mit interner Totalreflexions-fluoreszenzmikroskopie (TIRFM) näher zu untersuchen. Hierfür säten wir CTL auf Anti-CD3-beschichtete Deckgläser aus, wodurch sie zum Ausbilden einer IS sowie zur Fusion CD63-pHuji positiver Vesikel stimuliert wurden. Wir stellten zwei Typen von CD63-pHuji positiven Fusionsereignissen fest: einen Typ mit einem schnellen Anstieg und einen schnellen Abfall der Fluoreszenzintensität und einen Typ mit einem schnellen Anstieg aber einem langsamen Abfall der Fluoreszenzintensität. Es bestand jedoch ein fließender Übergang zwischen beiden Typen. Weil Calcium eine wichtige Rolle für die Exozytose verschiedener Vesikel spielt, gingen wir der Frage nach, ob dies auch für die Fusion CD63-pHuji positiver Vesikel gilt und konnten nachweisen, dass signifikant mehr CD63-pHuji positive Fusionsereignisse in extrazellulären [Ca2+] von 10 mM als in einer extrazellulären [Ca2+] von ca. 0,1 µM auftraten. Als nächstes widmeten wir uns der Untersuchung der Position der CD63-pHuji positiven Fusionsereignisse an der IS. Die ringförmige Anreicherung von kortikalem F-Aktin definiert verschiedene funktionelle Bereiche der IS. Deshalb beobachteten wir gleichzeitig die Fusion CD63-pHuji positiver Fusionsereignisse und das mit Lifeact-eGFP markierte F-Aktin. Es traten signifikant mehr CD63-pHuji positive Fusionsereignisse innerhalb des Aktin-Rings auf. Zuletzt untersuchten wir in CTL von GzmB-mTFP-Knock-in-Mäusen, die CD63-pHuji überexprimierten, ob bei der Fusion CD63-pHuji positiver Vesikel GzmB freigesetzt wird. Signifikant mehr CD63-pHuji positive Fusionsereignisse waren GzmB-mTFP positiv als GzmB-mTFP negativ. Zusammenfassend lässt sich anhand der Literatur und der Ergebnisse dieser Arbeit feststellen, dass CD63 kein optimaler Marker für MVBs und Exosomen in CTL ist, weil es sich auch auf CGs befindet. Unsere Daten können wie folgt interpretiert werden: 1. Bei den GzmB-negativen CD63-pHuji-positiven Fusionsereignissen handelt es sich am ehesten um MVBs mit Freisetzung von Exosomen, 2. Bei den CD63-pHuji-positiven Fusionsereignissen mit Freisetzung von GzmB-mTFP - gekennzeichnet durch einen schnellen Abfall von der mTFP-Fluoreszenz - handelt es sich möglicherweise um SCGs und 3. bei CD63-pHuji-positiven und GzmB-mTFP-positiven Fusionsereignissen ohne Abfall von mTFP-Fluoreszenz um MCGs.Summary of „Quantification of the fusion of CD63-positive ve-sicles by murine cytotoxic T-cells using real-time microscopy“
When a cytotoxic T cell (CTL) interacts with a virus-infected cell or cancer cell, the CTL is stim-ulated via the t-cell receptor (TCR) and the co-receptor CD8. An immune synapse (IS) is formed between the CTL and the target cell (TC) and the cytotoxic granules (CGs) polarize towards the IS. Eventually, CGs fuse at the IS, releasing their cytotoxic contents such as perforin and granzymes to destroy the TC. There are two classes of CGs: "single core granules" (SCGs), which release soluble cytotoxic proteins, and "multi core granules" (MCGs), which release su-pramolecular attack particles (SMAPs) and sometimes also exosomes. In recent years, there has been increasing evidence that CTL utilise another pathway for communication and cyto-toxicity via the release of extracellular vesicles (EVs) such as exosomes. Exosomes are EVs with
1 Zusammenfassung 3
a size of 30-100 nm that are released by fusion of multivesicular bodies (MVBs) with the plasma membrane. We wanted to find out whether CD63 is a suitable marker for MVBs and exosomes of CTL and whether CTL release exosomes at the IS. First, we investigated the local-ization of the exosome markers CD63 and CD81, which were labelled with the fluorescent proteins pHuji and pHluorin, in murine CTL in relation to granzyme B (GzmB) as a marker for CGs using structured illumination microscopy (SIM). We found a significantly higher co-locali-zation between CD63 and GzmB than between CD63 and CD81 or CD81 and GzmB. Due to the interesting co-localization between CD63 and GzmB, we decided to investigate the fusion of CD63-pHuji positive vesicles with total internal reflection fluorescence microscopy (TIRFM). Therefore, we stimulated CTL by anti-CD3-coated coverslips that induced them to form an IS and to fuse CD63-pHuji positive vesicles. We detected two types of CD63-pHuji positive fusion events: one type with a rapid increase and a rapid decrease in fluorescence intensity and one type with a rapid increase but a slow decrease in fluorescence intensity. However, there was a fluid transition between the two types. Because calcium plays an important role in the exo-cytosis of various vesicles, we investigated whether this also applies to the fusion of CD63-pHuji positive vesicles and were able to demonstrate that significantly more CD63-pHuji posi-tive fusion events occurred in extracellular [Ca2+] of 10 mM than in an extracellular [Ca2+] of about 0.1 μM. Next, we investigated the position of CD63-pHuji positive fusion events at the IS by simultaneously observing the fusion of CD63-pHuji positive fusion events and F-actin labelled with Lifeact-eGFP. The accumulation of cortical F-actin defines different functional areas of the IS. Significantly more CD63-pHuji positive fusion events occurred within the actin ring. Finally, we studied in CTL of GzmB-mTFP knock-in mice overexpressing CD63-pHuji, whether GzmB is released by CD63-pHuji positive vesicles. Significantly more CD63-pHuji pos-itive fusion events were GzmB-mTFP positive than GzmB-mTFP negative. In conclusion, based on the literature and the results of this work, CD63 is not an ideal marker for MVBs and exo-somes in CTL because it is also present on CGs. Our data can be interpreted as follows: 1. the GzmB-negative CD63-pHuji positive fusion events are most likely to be MVBs with release of exosomes, 2. CD63-pHuji-positive fusion events with release of GzmB-mTFP - characterised by a rapid decrease in mTFP - are possibly SCGs and 3. CD63-pHuji-positive and GzmB-mTFP-pos-itive fusion events without a decrease in mTFP are MCGs
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