1,720,976 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
Molecular characterization of ZC3H11A : functions and expression patterns during embryonic development
No full textThe previous discovery of a single nucleotide substitution in intron 3 of the insulin-like growth factor 2 (IGF2) gene in pigs revealed a novel mechanism for regulation of muscle growth. This mutation disrupts binding of a transcription factor, ZBED6. This domesticated DNA transposon is located within the first intron of ZC3H11A gene, which encodes a poorly characterized zinc finger binding protein. In this project, we attempted to characterize the expression patterns and biological function of ZC3H11A. We hypothesized that ZC3H11A may play a role in RNA splicing and muscle development. ZC3H11A was silenced in mouse myoblast cell lines using RNA interference. At 48 h post-transfection, total RNA was isolated and the expression levels of genes associated with myogenesis (MYOGENIN, PAX7 and SRF) and IGF2 regulation (ZBED6 and BAHD1) were quantified by real-time PCR. Effects of gene silencing on cell proliferation and differentiation were also assessed. The alternative splicing of various genes was evaluated in ZC3H11A-silenced cells. Whole mount mouse embryo and placenta samples were prepared for immunohistochemistry (IHC) at embryonic days 7.5, 8.5, 10.5, 12.5 and 13.5 to visualize the expression pattern of ZC3H11A during mouse embryo development. Results showed that silencing ZC3H11A was associated with a down-regulation of MYOGENIN, PAX7 and BAHD1 mRNA (p < 0.05). As silencing of ZC3H11A targets the transcript containing ZBED6, ZBED6 mRNA was also down-regulated (p < 0.001). When ZBED6 was knocked down in C2C12 cells using siRNA, IGF2 mRNA was up-regulated (P<0.001) more than 2-fold. No aberrant RNA splicing was detected in ZC3H11A-silenced cells. Immunohistochemical staining revealed a nuclear localization for the ZC3H11A protein. The ZC3H11A protein was restricted to certain tissues during embryo development, particularly cartilage and muscle. ZC3H11A appears to be a factor important for mammalian development. Because of the integration of ZBED6 into the first intron of the ZC3H11A gene and use of a common promoter for transcription, it is difficult to elucidate the underlying mechanisms regarding regulation and function of these two unique genes.Die kürzich erfolgte Entdeckung einer Nukleotidsubstitution im Intron 3 des insulin-like growth factor 2 (IGF2) Gens beim Schwein hat einen neuartigen Meschanismus zur Regulierung des Muskelwachstums aufgedeckt. Die Mutation verhindert die Bindung eines Transkriptionsfaktors, ZBED6. Das DNA Transposon findet sich im ersten Intron des ZC3H11A Gens, das für ein bislang schlecht characterisierets zinc finger binding Protein codiert. In diesem Projekt wurde versucht, die Expressionsmuster und biologische Funktionen von ZC3H11A zu charakterisieren. Es wurde angenommen, dass ZC3H11A eine Rolle im RNA splicing und in der Muskelentwicklung spielt. ZC3H11A wurde in Maus-Myoblasten-Zelllinien mit Hilfe von RNA Interferenz stillgelegt (silenced). 48 h post Transfektion wurde die gesamte RNA isoliert und die Expressionsmuster von Genen mit Effekt auf die Myogenese (MYOGENIN, PAX7 and SRF) und IGF2 Regulation (ZBED6 and BAHD1) mit Hilfe von real-time PCR quantifiziert. Die Ergbnisse zeigen, dass das Silencing von ZC3H11A eine Herunter-Regulierung von MYOGENIN, PAX7 und BAHD1 mRNA bewirkt (p < 0.05). Da das Silencing von ZC3H11A das Transcript, welches ZBED6 enthält, beeinflusst, war auch ZBED6 mRNA herunterreguliert. (p < 0.001). Kein abweichendes RNA Splicing wurde in ZC3H11A-silenced Zellen entdeckt. Das ZC3H11A Protein war auf bestimmte Gewebetypen während der Embryonalentwicklung beschränkt, besondes auf Bindegewebe und Muskel. ZC3H11A scheint ein für die Entwicklung von Säugetieren wichtiger Faktor zu sein. Wegen der Integration von ZBED6 in das erste Intron des ZC3H11A Gens ist es schwierig, die Effekte dieser beiden Gene bezüglich Zellregulation und Funktion zu trennen.Shady YounisWien, Univ. für Bodenkultur, Masterarb., 201
Functional characterization of the biological significance of the ZBED6/ZC3H11A locus in placental mammals
No full textThe recent advances in molecular and computational biology have made possible the study of complicated transcriptional regulatory networks that control a wide range of biological processes and phenotypic traits. In this thesis, several approaches were combined including next generation sequencing, gene expression profiling, chromatin and RNA immunoprecipitation, bioinformatics and genome editing methods in order to characterize the biological significance of the ZBED6 and ZC3H11A genes. A mutation in the binding site of ZBED6, located in an intron of IGF2, disrupts the binding and leads to 3-fold upregulation of IGF2 mRNA in pig muscle tissues. The first part of the thesis presents a detailed functional characterization of ZBED6. Transient silencing of ZBED6 expression in mouse myoblasts led to increased Igf2 expression (~2-fold). ChIP-seq analysis of ZBED6 and histone modifications showed that ZBED6 preferentially binds active promoters and modulates their transcriptional activities (paper I). In the follow-up studies using CRISPR/Cas9 we showed that either the deletion of ZBED6 or its binding site in Igf2 (Igf2ΔGGCT) led to more than 30-fold up-regulation of Igf2 expression in myoblasts. Differentiation of these genetically engineered cells resulted in hypertrophic myotubes. Transcriptome analysis revealed ~30% overlap between the differentially expressed genes in Zbed6-/- and Igf2ΔGGCT myotubes, with significant enrichment of muscle-specific genes. ZBED6-overexpression in myoblasts led to cell cycle arrest, reduced cell viability, reduced mitochondrial activities and impaired the differentiation of myoblasts (paper II). Further studies on cancer cells showed that ZBED6 influences the growth of colorectal cancer cells with dramatic changes in the transcription of hundreds of cancer-related genes (paper III). The phenotypic characterization of Zbed6-/- and Igf2pA/mG mouse models showed that the ZBED6-Igf2 axis has a major effect on regulating muscle growth and the growth of internal organs. Transcriptome analysis demonstrated a massive up-regulation of Igf2 expression (~30-fold) in adult tissues, but not in fetal tissues, of transgenic mice (paper IV). In the second part of the thesis we investigated the cellular function of Zc3h11a, the gene harboring ZBED6 in one of its first introns. The function of the ZC3H11A protein is so far poorly characterized. We show that ZC3H11A is a novel stress-induced protein that is required for efficient mRNA export from the nucleus. The inactivation of ZC3H11A inhibited the growth of multiple viruses including HIV, influenza, HSV and adenoviruses (paper V)
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
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