1,720,971 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
Effects of bFGF (Basic Fibroblast growth factor) on the Haematopoietic Sequelae that follow transplantation
Get PDFRecovery following bone marrow transplantation is associated with the reduction in the clonogenic potential of stroma-adherent CD34⁺ progenitors. The bone marrow stroma is also affected, resulting in poor support for the growth of stroma-adherent multipotent progenitors that form blastic colonies (CFU-bl). To determine the possible mechanisms of marrow damage in patients treated with peripheral blood stem cells (PBSCs) and bone marrow transplantation (BMT), we studied the effects of bFGF, a cytokine known to stimulate the survival and proliferation of fibroblasts, on the propagation of clonogenic progenitors and the marrow stroma. METHODS: In order to obtain the optimal bFGF concentrations to be used on patients' haematopoietic progenitors and bone marrow rnicroenvironment, haematologically normal individuals were studied in dose response studies. Control mononuclear cells from the Ficoll-Histopaque interface layer were divided into two aliquots: one to establish a stromal layer and to culture fibroblastic progenitors (CFU-Fs) in the presence of 0, 2 and 20 ng/ml bFGF with and without 20 ng/ml heparan sulphate (HS). The second aliquot was for the selection of the progenitor population. Stroma was quantitated by placing culture dishes on a grid containing 1mm squares and scoring the number of squares occupied by stromal layers as the percentage area covered. After 3 weeks of culture, a single cell suspension was prepared by incubation of stroma with 5% trypsin solution, and number of cells in the dishes enumerated with a particle counter. CFU-Fs were terminated on the 9th day of culture, stained with May-Grilnwald-Giemsa and scored using an inverted microscope. From the second aliquot, CD34⁺ cells were incubated with paramagnetic beads and target cells isolated with a magnet. Selected l x l 04/ml cells were cultured on prefom1ed controls' stroma that has been treated with 0, 2 and 20 ng/ml bFGF. Stroma-adhered cells were covered with 0.3% agar and cultured for 6 days. Aggregates of more than 20 cells were counted as CFU-bl. RESULTS: In normal individuals, the median surface area of the petri dish covered by stroma at 3 weeks of culture was 55% (range 30-65) and was significantly improved upon the addition of 2 ng/ml (median 70%; range 50-95 ; p= <0.05) and 20 ng/ml bFGF (median 80%; range 65-99; p= 0.004). Stromal cell numbers were 0.61 x 10⁶/2ml (range 0. 15-1.66), and they increased significantly with the addition of 2 and 20 ng/ml bFGF (p=0.03). The median colony forming unit-blasts (CFU-bl) scores were 121.8 x 10⁴/ml (range 43-271), and they expanded significantly with the addition of 20 ng/ml bFGF with and without heparan sulphate (p=0.03 and 0.01). It was then concluded that the 2 and 20 ng/ml bFGF with heparan sulphate be used on patients' cells in vitro. The median surface area covered by stromal layers in patients' samples at 3 weeks was 40% (range 0-55 vs. normal 50%), and it was in1proved significantly upon the addition of bFGF (median 78 vs. 50%; p= 0.001). Supplementation of stromal layers with bFGF accounted for a significant increase in patients stromal cell numbers (2.11 vs. normal 0.61 x 106/2ml; p< 0.05). Patients' CD34⁺ cells panned on normal stromal layers resulted in significantly fewer CFU-bl (median 40 vs. normal 90 x 10⁴/ml CFU-bl; p=0.009), but CFU-bl numbers were corrected following the addition of bFGF, matching the scores achieved by normal individuals (85 vs. normal 90 x l 04/ml). Normal CD34⁺ cells proliferated poorly on patients' stromal layers in the absence of bFGF (3 9 vs. normal 90 x 10⁴/ml), but colony numbers increased significantly upon addition of bFGF (91 vs. normal 90 x 10⁴/ml CFU-bl). Thirteen patients receiving peripheral blood stem cells (PBSCs) and nine patients undergoing bone marrow transplantation (BMT) were compared. These two stem cell sources were then compared to the normal population. Stromal layers in patients receiving PBSC grafts covered a greater surface area than the area covered in patients undergoing BMT (median 65 vs. 30%). They also had higher blastic colony than scores from BMT recipients (47 vs. 12 x 10⁴/ml CFU-bl; p= 0.2). Results can be summarized that bone marrow stroma from patients receiving mobilized progenitor cells proliferates better than those receiving bone marrow grafts. It can be concluded that poor stromal layer and CD34⁺ cell proliferation following peripheral blood stem cell transplantation can be corrected by addition of basic Fibroblastic Growth Factor
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
Splenectomy for immune thrombocytopenia : our 11-year experience
No full textSplenectomy has been practiced for the treatment of ITP for the past few decades. Currently it is utilised when a patient is either dependent or resistant to steroid treatment and the platelet count remains less than 30×109/L. Recently new agents have been added to the armamentarium used to treat ITP, including immune-suppressants such as rituximab and the new thrombopoetin-receptor agonists. This has brought into question the role of surgery for the treatment of ITP, and the need to compare the response and complication rates of splenectomy to these newer agents. Historic studies done on splenectomy for the treatment of ITP have been performed in the setting of low HIV prevalence. There is a relative paucity of data on the response rate in HIV-associated thrombocytopenia to splenectomy and the durability of response to splenectomy is unclear in this patient population. We retrospectively analysed 73 consecutive patients who underwent splenectomy for ITP from 2001 to 2011. The primary objective was to determine the rate of complete response, this was defined as a platelet count greater than 100×109/L at one year post splenectomy. Results were compared between HIV positive and HIV negative patients. The secondary objectives were: to evaluate the intra-operative and post†operative complications and mortality in the HIV positive and HIV negative groups, and to investigate for associations between co-morbidities, pre-operative treatment and response to splenectomy
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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