1,720,985 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
Study of the transcriptional regulation of hepatpcyte nuclear factor 4α
No full textThe work presented in the following pages focused on the elucidation of the mechanisms involved in the transcriptional regulation of the gene of hepatic nuclear factor 4α (HNF4α), a transcription factor which is expressed in a variety of tissues, such as the liver, the pancreas, the intestine and the kidney and which plays a significant role in the establishment and maintenance of the differentiated phenotype, in the organization of the specialized functions of those tissues. This is achieved through its participation in a regulatory network of transcription factors, the interplay and the interaction with relevant target genes of which determines the balanced expression of those gene products that are responsible for the function of the tissue. This work aimed at the understanding of the factors and mechanisms through which the expression of human HNF4α is regulated. To this end, as is presented in the first part of the work, 12.1 kb of upstream sequences of the gene were cloned and analyzed. Major sites of DNaseI hypersensitivity were identified both in the proximal promoter region and the first intron of the gene and in the upstream region, -6.6, -8.0 and -8.8 kb 5 of the transcription start site. Transient transfection experiments using reporter genes under the control of progressive 5 deletions of the regulatory region demonstrated that the region of the proximal promoter was sufficient for the induction of high levels of transcription in hepatic cells. DNaseI footprinting analysis and electrophoretic mobility shift assays revealed binding sites for the transcription factors HNF1α and β, Sp1, GATA6 and HNF6 in this region. Synergy between HNF1α and HNF6 and HNF1β and GATA6 produced high levels of transcription from the promoter, indicating that there are at least two alternative mechanisms for the transcriptional activation of the HNF4α gene. Chromatin immunoprecipitation experiments demonstrated that in differentiated hepatic cells it is the transcription factos HNF1α, HNF6, Sp1 and COUPTFII that interact with the promoter. The latter represses the promoter through a hormone response element that is not conserved in the homologous mouse region. This element was shown to respond to retinoic acid signaling, as incubation of cells with RA leads to the recruitment of the respective receptors to the promoter and to the upregulation of HNF4α expression levels. The second part of this work investigates the order of factor recruitment and chromatin modifications to the proximal promoter and an upstream enhancer of the human HNF4α gene, located -6.6 kb upstream of the transcription start site, around the initial activation of the gene during the differentiation of human enterocytes. These experiments demonstrated that two independent protein complexes formed in the two regulatory regions, which included transcription factors, acetyltransferases and chromatin remodelers at the enhancer and transcription factors, general transcription factors and RNA polymerase-II at the promoter. These events were followed by a unidirectional movement of the enhancer complex along the intermediate regions until it encountered the proximal promoter. This movement was accompanied by a spreading of histone hyperacetylation from the enhancer towards the promoter. The initiation of transcription from the gene coincided with the formation of a stable enhancer-promoter complex and the remodeling of the nucleosomes covering the transcription start site. These results gave a more complete picture of the events that take place in the regulatory regions of human HNF4α around the initial activation of the gene during a cellular differentiation model. They also provided experimental validation for a mechanism by which the communication between topologically remote regulatory regions is achieved through their physical contact and thus gave a mote complete picture of the complexity of the process of the transcriptional of at least one tissue-specific gene.Η παρούσα εργασία επικεντρώθηκε στη διασαφήνιση των μηχανισμών μεταγραφικής ενεργοποίησης του γονιδίου του ανθρώπινου ηπατικού πυρηνικού παράγοντα 4α (hepatic nuclear factor 4α, HNF4α). Ο HNF4α είναι ένας μεταγραφικός παράγοντας ο οποίος εκφράζεται σε μία πληθώρα ιστών, όπως το ήπαρ, το πάγκρεας, το έντερο και το νεφρό και παίζει σημαντικότατο ρόλο στη διατήρηση του διαφοροποιημένου φαινοτύπου, στην οργάνωση της επιτέλεσης, δηλαδή, των εξειδικευμένων λειτουργιών των ιστών αυτών. Αυτή τη λειτουργία την επιτυγχάνει μέσω της συμμετοχής του σε ένα ρυθμιστικό δίκτυο μεταγραφικών παραγόντων, των οποίων οι αλληλεπιδράσεις τόσο μεταξύ τους όσο και με τα γονίδια- στόχους τους καθορίζουν την ισορροπημένη έκφραση των γονιδιακών προϊόντων που είναι υπεύθυνα για την ομαλή λειτουργία του ιστού. Η εργασία αυτή στόχευε στην κατανόηση των παραγόντων και μηχανισμών με τους οποίους η ρυθμίζεται η έκφραση του ανθρώπινου HNF4α. Προς αυτό το σκοπό, όπως παρουσιάζεται στο πρώτο μέρος, κλωνοποιήθηκαν και αναλύθηκαν περίπου 12,1 kb αλληλουχιών 5' του γονιδίου. Ταυτοποιήθηκαν κύριες θέσεις υπερευαισθησίας σε DnaseI τόσο στον εγγύς υποκινητή και στο πρώτο ιντρόνιο του γονιδίου, όσο και στην 5' περιοχή, στις θέσεις -6,6, -8,0 και -8,8 kb 5' του σημείου έναρξης της μεταγραφής. Πειράματα παροδικής διαμόλυνσης με γονίδιο αναφοράς υπό των έλεγχο προοδευτικών 5' ελλείψεων της ρυθμιστικής περιοχής έδειξαν ότι η περιοχή του εγγύς υποκινητή ήταν ικανή να επάγει υψηλά επίπεδα μεταγραφής σε ηπατικά κύτταρα. Πειράματα ανάλυσης αποτυπωμάτων μεταγραφικών παραγόντων σε DNA (DNaseI footprinting) και μεταβολής της ηλεκτροφορητικής κινητικότητας του DNA (EMSA) αποκάλυψαν θέσεις πρόσδεσης για τους μεταγραφικούς παράγοντες HNF1α και β, Sp1, GATA6 και HNF6 σε αυτή την περιοχή. Η συνεργατική δράση των HNF1α και HNF6 και των HNF1β και GATA6 αντίστοιχα επήγαγε υψηλά επίπεδα μεταγραφής από τον υποκινητή, κάτι που έδειξε ότι υπάρχουν τουλάχιστον δύο εναλλακτικοί μηχανισμοί μεταγραφικής ενεργοποίησης του γονιδίου του HNF4α. Σε ότι αφορά τη μεταγραφή του γονιδίου σε διαφοροποιημένα ηπατοκύτταρα, πειράματα ανοσοκατακρήμνισης χρωματίνης έδειξαν ότι, σε ανθρώπινη ηπατική κυτταρική σειρά, οι παράγοντες HNF1α, HNF6, Sp1 και COUPTFII αλληλεπιδρούν σταθερά με τον υποκινητή. Ο τελευταίος καταστέλλει τη δράση του υποκινητή μέσω ενός στοιχείου απόκρισης σε ορμόνες (hormone response element), το οποίο μάλιστα δεν υπάρχει στον ομόλογο υποκινητή του ποντικού. Το στοιχείο αυτό δείχθηκε ότι αποκρίνεται και σε ρετινοϊκό οξύ, καθώς επώαση κυττάρων με το τελευταίο οδηγεί στη στρατολόγηση των αντίστοιχων υποδοχέων στον υποκινητή και αύξηση των επιπέδων έκφρασης του HNF4α. Στο δεύτερο μέρος της εργασίας παρουσιάζεται η μελέτη της σειράς στρατολόγησης παραγόντων και των μεταβολών της χρωματίνης στον εγγύς υποκινητή και σε έναν 5' ενισχυτή του HNF4α -6,6 kb από το σημείο έναρξης της μεταγραφής κατά την αρχική ενεργοποίηση του γονιδίου στη διάρκεια της διαφοροποίησης ανθρώπινων εντερικών κυττάρων. Τα πειράματα αυτά έδειξαν ότι στις δύο αυτές περιοχές σχηματίζονταν αρχικά ανεξάρτητα συσσωματώματα πρωτεϊνών, που περιελάμβαναν μεταγραφικούς παράγοντες, ακετυλοτρανσφεράσες και αναδιαμορφωτές της χρωματίνης στον ενισχυτή και μεταγραφικούς παράγοντες, γενικούς μεταγραφικούς παράγοντες και την RNA πολυμεράση-ΙΙ στον υποκινητή του γονιδίου. Τα γεγονότα αυτά ακολουθούσε μετακίνηση του συμπλόκου του ενισχυτή κατά μήκος των ενδιάμεσων περιοχών μέχρι τη συνάντησή του με τον υποκινητή. Η κίνηση αυτή συνοδευόταν από εξάπλωση της υπερακετυλίωσης των ιστονών από τον ενισχυτή αρχικά προς τον υποκινητή. Η έναρξη της μεταγραφής του γονιδίου συνέπιπτε με το σχηματισμό ενός σταθερού συσσωματώματος αποτελούμενου από τις πρωτεΐνες και των δύο περιοχών. Συνέπιπτε επίσης με την αναδιαμόρφωση του νουκλεοσώματος που κάλυπτε τη θέση έναρξης της μεταγραφής. Τα αποτελέσματα αυτά έδωσαν συνολικά μία πιο πλήρη εικόνα για τα γεγονότα που συμβαίνουν στις ρυθμιστικές περιοχές του HNF4α κατά την αρχική ενεργοποίηση του γονιδίου στη διάρκεια ενός μοντέλου κυτταρικής διαφοροποίησης. Παρείχαν επίσης πειραματική επιβεβαίωση για ένα μηχανισμό με τον οποίο επιτυγχάνεται η επικοινωνία μεταξύ τοπολογικά απομακρυσμένων ρυθμιστικών περιοχών μέσω φυσικής επαφής τους και έδωσαν έτσι μία πιο πλήρη εικόνα της πολυπλοκότητας της διαδικασίας της μεταγραφικής ενεργοποίησης ενός τουλάχιστον ιστο-ειδικού γονιδίου
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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