1,720,958 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
Identificatie en karakterisatie van genen en proteïnen in het actiemechanisme van 1,25-dihydroxyviatamin D3 in MC3T3-E1 muizen osteoblastcellen
No full textThe secosteroid hormone vitamin D3 was discovered as an essential nutrient for the prevention of rickets. The active form of vitamin D3, 1,25(OH)2D3, is indispensable to sustain calcium and phosphorus homeostasis and bone metabolism. These features, often summarized as the classical actions of 1,25(OH)2D3, are carefully balanced in a regulation circuit which involves the parathyroid hormone (PTH) as a main counterpart. The exact changes induced by 1,25(OH)2D3 in the gene expression program of bone cells are far from resolved and the identification of new vitamin D receptor (VDR) target genes will contribute to a better understanding of the influence of 1,25(OH)2D3 on bone. The first objective of this study was to investigate in more detail the effects of 1,25(OH)2D3 on the cystathionine ß-synthase gene, Cbs, in murine pre-osteoblastic MC3T3-E1 cells. In a microarray experiment on MC3T3-E1 cells, Cbs was first found to be highly and sustainably upregulated by 1,25(OH)2D3. Subsequent qRT-PCR experiments and Western blotting confirmed the increase of Cbs mRNA and higher CBS protein levels after 1,25(OH)2D3 treatment in murine MC3T3-E1 cells. The CBS protein is the initial enzyme of the transsulfuration pathway, a metabolic sequence necessary for irreversible homocysteine (HCY) breakdown and cysteine creation. Higher levels of CBS and increased enzymatic activity after 1,25(OH)2D3 treatment were accompanied by an enhanced consumption of intracellular HCY and an increase in cystathionine and cysteine levels which also affected the composition of the cell supernatant accordingly. The fact that 1,25(OH)2D3 is able to alter Cbs expression not only in MC3T3-E1 cells stressed the general nature of this finding. Furthermore, the study on the relationship between serum HCY and 25(OH)D3 levels in humans revealed a significant relationship between both parameters. The analysis showed that HCY levels reached a minimum when 25(OH)D3 levels were around 50 nM (20 ng/mL). Cbs transcription is directly transcriptionally controlled by VDR which was suggested by decreased Cbs expression in primary Vdr knockout osteoblasts and later shown by ChIP-on-chip and subsequent transfection experiments. Computer-based analysis of the murine Cbs gene revealed the presence of a putative DR3-type 1,25(OH)2D3 responsive element (VDRE) within the second Cbs intron. The functionality of the newly identified VDR-binding site was proven by mutation analysis linked to transfection experiments. To conclude this part of the study, we demonstrated that HCY concentration and metabolism were connected to 1,25(OH)2D3 via the upregulation of the cystathione ß-synthase gene Cbs on bone. This may have implications for bone health since high HCY levels have detrimental effects on bone stability and are also associated with an increased risk of osteoporosis. A local decrease in HCY levels may therefore be beneficial for bone health even if the systemic HCY level is not or only slightly altered, which may be due to the unresponsiveness of hepatic HCY metabolism to 1,25(OH)2D3. <br>Our second aim was to obtain a better understanding of semaphorin (SEMA) signalling in bone cells. This was prompted by the observed upregulation of neuropilin 2 (Nrp2) and Sema3c expression seen in a microarray experiment performed on 1,25(OH)2D3-treated MC3T3-E1 cells. The different genes coding for the proteins of the SEMA3 signalling complex are involved in the regulation of developmental, regulatory, and pathological processes. Nevertheless, the exact function of most of these genes in bone-related processes is still unresolved. By using qRT-PCR, we determined the changes in gene expression after 1,25(OH)2D3 treatment. Additional ChIP-on-chip experiments suggested the binding of VDR and the retinoid X receptor (RXR) and the presence of acetylated histone 4 (H4-Ac) in the genomic regions of Sema3b, Sema3f, Nrp2, and plexin (Plxn) A1. In silico screening of these genes revealed the presence of DR3-type VDRE sites in their introns or promoters. Except from Sema3b, which was already suggested to be a direct VDR target, all the other genes had not yet been described to be under direct control of 1,25(OH)2D3. The functionality of the newly identified VDREs and their involvement in 1,25(OH)2D3-driven upregulation was furthermore confirmed by mutation analysis connected to reporter gene analysis. In addition, we demonstrated that almost all examined Sema3s, Nrps, Plxnas, and Plxnd1 had also a 1,25(OH)2D3-independent role in bone biology because of the strong changes in gene expression during osteoclastogenesis and mineralization. These findings stressed that SEMA3 signalling is also present in bone where it may influence processes essential for bone homeostasis, a finding that demands further detailed examination.The third aim of this study was to gain more insights into the changes that occur after 1,25(OH)2D3 treatment on the proteome level of MC3T3-E1 pre-osteoblasts. We used two dimensional fluorescence difference gel electrophoresis (2-D DIGE) and found that the observed alterations caused by 1,25(OH)2D3 were mostly seen after 24 h of treatment. By MALDI-TOF/TOF MS we were able to identify in total, 50 protein spots that accounted for 41 distinct proteins. Among these regulated proteins, most could be classified to categories that included proteins involved in cell cycle regulation, cytoskeletal adaptation but also to protein structure and modification, stress response, metabolism or transport and redox signalling. The most prominent proteins identified were procollagen-lysine,2-oxoglutarate 5-dioxygenase 2 isoform 2 (PLOD2), aldose reductase-related protein 2 (AKR1B8), and chloride intracellular channel protein 4 (CLIC4). Of interest to us, PLOD2 and AKR1B8 are necessary for collagen cross-linking and for advanced glycation end product (AGE) elimination and therefore necessary for bone health. Also CLIC4 may have implications for bone homeostasis since also other chloride channel proteins are known to be involved in bone homeostasis. From the identified proteins, five were also found to be regulated on the previously performed microarray experiment on MC3T3-E1 cells. From these proteins, three were downregulated [DNA replication licensing factor mini-chromosome maintenance 7 (MCM7), proliferating cell nuclear antigen (PCNA), and stathmin (STMN1)] and two upregulated [purine nucleoside phosphorylase (PNP1) and CLIC4)]. This weak overlap is in accordance with the already described differences between transcriptome and proteome analysis and emphasizes the advantage to combine both kind of data sets, which complement each other and may help to get a more complete overview of the effects caused by 1,25(OH)2D3 treatment in bone cells.In general, this study contributed to a better understanding of the regulatory network of 1,25(OH)2D3 on osteoblasts. Moreover, the obtained data and findings unravel additional direct effects of 1,25(OH)2D3 on bone.status: Publishe
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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