1,720,955 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
Structural and Functional Insights into Na+/I− Symporter (NIS) Transport Mechanisms and Their Implications for NIS-Mediated Internal Radiation Therapy
No full textThe Na+/I- symporter (NIS) is a plasma membrane protein crucial for human health, and a central player in both physiology and targeted internal radiation therapy. In the thyroid gland, NIS mediates the active, electrogenic transport of iodide (I⁻) with a 2 Na⁺ : 1 I⁻ stoichiometry—and this is the first, and the rate-limiting, step in the biosynthesis of the thyroid hormones (THs). These hormones, triiodothyronine (T₃) and thyroxine (T₄), are essential regulators of metabolism, influencing growth, development (especially that of the central nervous system), and energy balance. Deficiencies in I⁻ uptake or TH production can lead to severe disorders, including hypothyroidism, goiter, and developmental delays, underscoring how critical it is that the delicate homeostatic balance of circulating TH levels be maintained.
Beyond its indispensable role in physiology, NIS underpins the highly successful treatment for thyroid cancer based on radioiodide. Because many thyroid malignancies retain functional NIS expression, metastatic or residual thyroid cancer cells can be selectively targeted using radioactive 131I⁻ isotopes administered systemically post-thyroidectomy. This strategy exploits the ability of NIS-expressing cells to concentrate radioiodide, delivering cytotoxic radiation specifically to malignant tissue while largely sparing healthy organs. Because NIS is naturally expressed predominantly in thyroid tissue, radioiodide therapy remains one of the most elegantly selective anticancer therapies ever devised.
Interestingly, NIS not only transports I⁻ with a 2 Na⁺ : 1 I⁻ stoichiometry, but also transports oxyanions, such as pertechnetate (⁹⁹ᵐTcO₄⁻), perrhenate (ReO₄⁻), and the environmental pollutant perchlorate (ClO₄⁻). Strikingly, these oxyanions are transported with a different, electroneutral stoichiometry of 1 Na⁺ : 1 XO₄⁻. Chapter 2 of this dissertation investigates how the same transporter can switch between a 2 Na⁺ : 1 I⁻ (electrogenic) and a 1 Na⁺ : 1 XO₄⁻ (electroneutral) transport stoichiometry. We conducted transport assays and made electrophysiological measurements, and analyzed the data using a statistical thermodynamics-based equation. Our results show that ClO₄⁻ not only competes directly with I⁻ at the substrate binding site, but also binds at a high-affinity non-transport allosteric site. In so doing, ClO₄⁻ prevents one of the two Na⁺ ions from binding to NIS, effectively shifting I⁻ transport toward a 1 Na⁺ : 1 I⁻ stoichiometry and thus substantially diminishing the driving force for I⁻ accumulation. This finding implies that even low levels of ClO₄⁻ in drinking water may be more detrimental to thyroid physiology than previously believed, indicating that environmental safety standards for perchlorate pollution need to be reassessed.
Chapter 3 lays out how we determined the first high-resolution cryo-electron microscopy (cryo-EM) structure of a mutant NIS protein, Q72A NIS. Replacing Glu at position 72 with Ala disrupts Na⁺ binding at the Na1 and Na2 sites, and alters the conformation of transmembrane segment 2. Although this mutant does not transport I⁻, it still transports ReO₄⁻—and, crucially, it does so electrogenically, with a 2 Na⁺ : 1 ReO₄⁻ transport stoichiometry (rather than a 1 Na⁺ : 1 ReO₄⁻ stoichiometry). Detailed structural analysis reveals two newly formed Na⁺ sites (Na3 and Na4) along the translocation pathway leading to the cytoplasm, showing how even single amino acid substitutions can drastically change substrate selectivity and stoichiometry. These findings deepen our understanding of the structural plasticity of NIS and of how it coordinates ions.
Finally, chapter 4 investigates how NIS could be used to develop innovative cancer therapies, particularly ones for non-thyroidal cancers. By introducing point mutations within the π-helix of transmembrane segment 7, we engineered a variant (the L253P/V254F double mutant, dubbed PF NIS) that efficiently transports oxyanions but transports only a negligible amount of I⁻. To uncover the structural basis for this phenomenon, we determined the cryo-EM structure of PF NIS at 2.58 Å, the highest resolution achieved for any NIS structure to date. Crucially, this structure explains how NIS binds and transports 2 Na+ ions. We propose that this selectively reprogrammed PF NIS protein could be expressed in non-thyroidal cancers by gene transfer, and the malignancies then treated with radioactive 188ReO4- while protecting the thyroid by simultaneously administering non-radioactive I-. The non-radioactive I- would not prevent the cancer cells from accumulating 188ReO4-, but it would prevent healthy thyroid cells from doing so (by saturating WT NIS). As a proof of concept, we tested this hypothesis in in vitro experiments. This idea paves the way for a new approach to treating cancer that relies on the genetic transfer of engineered NIS molecules into non-thyroidal tumors, with fewer off-target side effects.
All in all, then, this work combines biochemical, functional, and structural strategies to reveal how the mechanism by which NIS couples ions changes depending on the substrates; identifies residues critical for determining substrate selectivity and transport stoichiometry; and proposes new ways to exploit NIS to treat non-thyroidal cancers in a targeted fashion. These findings not only deepen our fundamental understanding of an essential transporter involved in both normal endocrinology and cancer treatment but also have direct implications for how water pollution should be tackled and what strategies should be deployed in developing some next-generation of anticancer therapies
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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