1,720,962 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Angiogenese bei der Transplantat-gegen-Wirt Reaktion
No full textFor a variety of hematopoietic diseases, allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only curative treatment option. Due to numerous improvements in the treatment procedure and the constant expansion of indications, the number of transplanted patients has increased rapidly during the last decades. Despite many achievements, the mortality rate after allo-HSCT is still high. The main and most severe complication after allo-HSCT is the graft- versus-host disease (GVHD) and up to 30% of allo-HSCT recipients die due to GVHD or GVHD-related side effects. GVHD is characterized by a systemic inflammatory reaction that is mainly mediated by alloreactive T cells. Alloreactive T cells cause severe tissue damage in main GVHD target organs colon, liver and skin via different cytotoxic mechanisms. All current treatment options aim at the suppression of T cell function, however, the inhibition of immune responses results in an increased risk for infections and tumor relapse. Therefore, there is a clear medical need in defining alternative targets for the development of therapies that act without hampering immune functions.
Recent work by us and others, identified an important role of the endothelium in the development of acute GVHD (aGVHD). However, the inhibition of vascular endothelial growth factor receptor 1 (VEGFR1) and VEGFR2, key mediators of angiogenesis, led to impaired hematopoietic engraftment, which is essential for a beneficial transplantation outcome. This thesis discusses two new approaches for the treatment of aGVHD after allo-HSCT. The first part of this work deals with an aspect that has not been studied in the context of aGVHD before, namely lymphangiogenesis. It is well known that lymph vessels carry out important immunologic functions and that lymphangiogenesis is involved in inflammation, cancer and graft rejection. However, the influence of lymphangiogenesis on inflammation can be beneficial or harmful and seems to depend on various factors such as the inflammatory trigger and the site of inflammation.
Evaluation of murine and human tissue samples showed a significant increase in lymph vessel density during aGVHD, confirming the clinical relevance of lymphangiogenesis in aGVHD. The inhibition of VEGFR3, a main regulator of lymphangiogenesis, revealed that reduced lymphangiogenesis attenuates clinical and histopathological features of aGVHD, without affecting malignant lymphoma growth.
In the second part of the thesis an alternative pathway of hemangiogenesis is investigated. Besides the prominent vascular endothelial growth factor (VEGF)/VEGFR signaling, an alternative pathway involved in angiogenesis is the transforming growth factor-beta (TGF-b) pathway. Depending on downstream signaling, the TGF-b pathway can initiate or inhibit angiogenesis. A study by Greenwood et al. identified the glycoprotein leucine-rich alpha-2-glycoprotein 1 (Lrg1) as regulator of the angiogenic switch in TGF-b signaling. Elevated serum levels of Lrg1 in samples from patients with inflammatory diseases further confirmed the assumption that Lrg1 is expressed under pathological rather than physiological conditions. The correlation between Lrg1-regulated TGF-b signaling and angiogenesis during aGVHD has not been investigated so far. We show that Lrg1 expression is increased in target organs during aGVHD and that the genetic loss of Lrg1 attenuates aGVHD. Using the additional inflammation models of experimental colitis and paw edema, we could also show that Lrg1 contributes to angiogenesis, altered vessel structure and increased inflammation in these disease models.
With this work, we were able to confirm the crucial role of the lymphatic and blood vascular system during aGVHD. We identified two novel factors that provide potential therapeutic targets to reduce aGVHD without interfering with anti-tumor immunity and immune reconstitution
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
Full text linkWe 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
Der pro-angiogene Effekt von Lrg1 bei der graft-vs-host Krankheit
No full textDie hämatopoetische Stammzelltransplantation (HSZT) wird bei einer Vielzahl von hämatologischen Erkrankungen als Therapie eingesetzt. Die Erfolgsrate der Behandlung ist jedoch trotz ständiger Verbesserungen begrenzt. Eine häufige und schwere Nebenwirkung nach allogener HSZT ist die graft-vs-host Krankheit (engl. GVHD). In Vorarbeiten konnte mein Gastlabor zeigen, dass die Neovaskularisierung ein wesentlicher Faktor bei der Entwicklung der GVHD ist. Unklar ist jedoch bisher der Mechanismus der GVHD-assoziierten Neovaskularisierung. Kürzlich wurde von Wang et al. ein Protein entdeckt (leucine-rich alpha-2-glycoprotein 1; Lrg1), welches über eine Aktivierung des pro-angiogenen Tgf-β Signalwegs zur Ausbildung neuer Blutgefäße beiträgt.
Ziel dieses Projekts war es, die Relevanz von Lrg1 und des Tgf-β Signalweges für die Neovaskularisierung während der GVHD zu erforschen.
In murinen HSCT Modellen konnten wir während der GVHD in Immunhistochemie und FACS eine erhöhte Gefäßdichte in den Zielorganen der GVHD feststellen. Real-time PCR und Proteomics Analysen haben gezeigt, dass während der GVHD eine erhöhte Expression von Lrg1 und TGF-ß in Zielorganen auftritt.
Unsere Ergebnisse identifizieren Lrg1 als möglichen therapeutischen Ansatz während der GVHD. Wir planen in Zukunft Lrg1 genetisch und pharmakologisch zu hemmen, um die Rolle von Lrg1 bei der GVHD näher zu untersuchen.Hematopoietic stem cell transplantation (HSCT) is used as treatment for several disorders of the hematopoietic system. However, in spite of considerable improvements, the success rate of HSCT is limited. Graft-vs-host disease (GVHD) is the most severe complication and causes significant mortality after allogeneic HSCT.
In preliminary experiments my guest lab was able to show that neovascularization is associated to GVHD.
Recently, Wang et al. discovered a protein, leucine-rich alpha-2-glycoprotein 1 (Lrg1), which contributes to the activation of the pro-angiogenic pathway that causes the formation of new blood vessels.
The aim of this project was to examine the relevance of Lrg1 and the Tgf-β pathway for neovascularization during GVHD. Using immunhistochemestry and FACS we determined an increased vessel density during GVHD in GVHD target organs of murine HSCT models.
Real-time PCR and proteomic analyses showed that the expression of Lrg1 and Tgf-β is upregulated in target organs during GVHD.
Our results identify Lrg1 as possible therapeutic approach for GVHD.
We are planning to inhibit Lrg1 genetically and pharmacologically to further investigate the role of Lrg1 in GVHD.vorgelegt von: Sarah MerlitzMolecular BiotechnologyWien, FH Campus Wien, Masterarb., 201
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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