1,720,961 research outputs found

    Papel de la quinasa humana VRK1 en la biología del neuroblastoma

    Get PDF
    El neuroblastoma es el tumor extracraneal sólido más frecuente en la infancia. Su comportamiento es muy heterogéneo, pudiéndose dar desde regresión espontánea hasta tumores metastásicos muy agresivos. Uno de los factores pronóstico más usados es la amplificación del oncogén MYCN, que es indicativo de baja supervivencia. Aunque, dada la baja supervivencia de los pacientes con versiones agresivas de la enfermedad, sigue siendo necesaria la identificación de nuevos factores pronóstico y el desarrollo de nuevas herramientas terapéuticas. Entre las cuestiones a dilucidar, está la posible implicación de las llamadas células madre cancerosas en el origen y progresión tumoral. El objetivo del presente proyecto de tesis doctoral ha sido estudiar la función de la quinasa humana VRK1 en los neuroblastomas más agresivos, su potencial como factor pronóstico y diana terapéutica, así como su posible implicación en las poblaciones de células madre cancerosas. Para estudiar la expresión de dicha proteína y su asociación con la malignidad tumoral, hacemos uso de datos provenientes de tumores de neuroblastoma, muestras de tumores humanos y líneas celulares. A través de diferentes técnicas de laboratorio, hemos analizado su expresión, génica y proteica, y estudiado su función, además de silenciar específicamente su expresión para realizar ensayos funcionales in vitro e in vivo en modelos de NB. Los resultados obtenidos indican que la proteína VRK1 se encuentra altamente expresada en los tumores de neuroblastoma más agresivos, teniendo valor pronóstico incluso en los tumores MYCN no amplificado. También hemos analizado la expresión de esta proteína en células progenitoras de neuroblastoma y hemos encontrado una relación entre VRK1 y proliferación en este tipo de población celular. Además, una reducción en la expresión de esta quinasa en las células cancerosas produce una parada del ciclo celular, mayor diferenciación y sensibilidad al tratamiento. Creemos que el trabajo aquí presente sienta las bases para un estudio más detallado sobre un posible nuevo uso terapéutico en este complicado cáncer infantil.Neuroblastoma is the most common solid extracranial tumor in childhood with a very heterogeneous behavior, ranging from spontaneous regression to very aggressive metastatic tumors. One of the most used prognostic factors to date is the amplification of the MYCN oncogene, which is indicative of low survival, Although, given the low survival of patients with aggressive versions of the disease, the identification of new expected factors and the development of therapeutic tools. Among the issues to be elucidated, is the possible implication of the so-called cancer stem cells at the origin and tumor progression. The objective of this doctoral thesis project has been to study the role of human kinase VRK1 in the most aggressive neuroblastomas, and its possible involvement in cancerous stem cell populations. To study the expression of said protein and its association with tumor malignancy, we make use of data from neuroblastoma tumors, human tumor samples and cell lines. Through different laboratory techniques, we have analyzed their expression, gene and protein, and studied their function, in addition to specifically silencing their expression to perform functional tests in vitro and in vivo in NB models. The results indicate that the VRK1 protein is highly expressed in the most aggressive neuroblastoma tumors, having predictive value even in nonamplified MYCN tumors. We have also analyzed the expression of this protein in neuroblastoma progenitor cells and have found a relationship between VRK1 and proliferation in this type of cell population. In addition, a reduction in the expression of this kinase in cancer cells causes a stop in the cell cycle, greater differentiation and sensitivity to treatment. We believe that the work presented here lays the groundwork for a more detailed study on a possible new therapeutic use in this complicated childhood cancer

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Get PDF
    The 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 PDF
    We 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 PDF
    We 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

    Author Index

    No full text
    Nao informado

    koamabayili/VECTRON-author-checklist: VECTRON author checklist

    No full text
    We 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 Under Sail The Imagination of Jack London, 1893-1902

    No full text
    In 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
    corecore