1,720,953 research outputs found
Role of Eph/ephrin Molecules in Mediating Cross-talk Between Stromal and Neural Populations in the Regulation of Neural Differentiation, Adhesion and Migration
Get PDFThere is substantial evidence from the literature that suggests a close association between the skeletal and nervous systems at the anatomical and physiological level, and this cellular and molecular cross-interaction has been termed the neuro-osteogenic network, critical for skeletal growth, homeostasis, and repair.
The Eph and ephrin molecules are the largest family of receptor tyrosine kinases. These membrane-bound molecules are contact-dependent and predominantly function through cell-to-cell interactions. Forward signalling occurs when the ephrin ligand activates signalling in the Eph expressing cell while reverse signalling can also occur where Eph receptors activate signalling through the ephrin ligand expressing cells. The Eph/ ephrin interactions have known roles independently in the skeletal system regulating bone homeostasis, and skeletal growth and repair, and within the nervous system influencing axon guidance and patterning. Therefore, the roles of Eph/ ephrin mediated cross talk between neural and bone marrow stromal cell (BMSC) populations in regulating neural differentiation, adhesion and migration were investigated.
An in vitro neural differentiation assay was established for the human neuroblastoma line SH-SY5Y which showed upregulated expression of EPHRINA2, EPHRINA5 and EPRHINB1 with the progression of neuronal differentiation. Previous studies in our laboratory have shown that human BMSC highly express EPHA3, EPHA4, EPHB2 and EPHB4 at the gene and protein levels. Therefore, the roles of Eph/ ephrin interacting pairs in mediating cross -communication between BMSC and neurons, respectively, were assessed. These included the stromal expressing Eph receptors with neural expressing ephrin ligands (1) EphA3/A4 with ephrinA2 (2) EphA3/A4 or EphB2 with ephrinA5 and (3) EphB2/B4 with ephrinB1, respectively. To examine the importance of ephrin reverse signalling on neural differentiation, adhesion and migration, soluble EphA3-Fc, EphA4-Fc, EphB2-Fc, EphB4-Fc fusion molecules, were used to activate reverse signalling of the ephrinA2, ephrinA5 and ephrinB1 ligands, respectively. The gene expression of early and mature neuronal and sensory markers in the SH-SY5Y line showed a differential response following activation of the ephrinA and ephrinB ligands during neural induction. However, there was no significant difference in neuronal morphology. The activation of both ephrinA and ephrinB ligands inhibited SH-SY5Y neural adhesion, with reduced neural adhesion in response to EphA4-Fc, EphB2-Fc and EphB4-Fc for two hours, and in response to EphA4-Fc and EphB4-Fc for twenty-four hours. EphB2-Fc and EphB4-Fc stimulation did not exert an effect on neural transwell migration where these molecules were not in direct contact with the neural-like cells. There was no significant difference in neural adhesion, or neural and stromal migration, in response to blocking ephrinB1 on the neural population. To determine functional relevance of the neuro-osteogenic network, the avian embryo dorsal root ganglia (DRG) that innervate the hind limbs, were cultured in vitro in the presence of a range of Eph-Fc molecules. DRG neurite cell bodies within the Eph-Fc occupied spaces was significantly decreased for DRG pooled from the lumbar region while a strong trend of differential DRG neurite cell body number and neurite invasion was observed within the Eph-Fc occupied spaces for DRG from specific lumbar compartments. Future studies would investigate the importance of ephrinA2, ephrinA5 and ephrinB1 mediated cross-communication between the neural and BMSC populations during skeletal and neural development and fracture repair.Thesis (M.Phil) -- University of Adelaide, Adelaide Medical School, 202
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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