1,721,327 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
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
Untersuchung der Rolle von Tbc1d8b in der Endozytose und funktionelle Charakterisierung von Patientenmutationen in Drosophila
No full textkoamabayili/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
Using transgenic Drosophila model to study the mechanism of APOL1-associated cytotoxicity
No full textThe high prevalence of G1-APOL1 and G2-APOL1 risk variants among African populations is due to the fact that the two risk alleles protect humans from infection by Trypanosoma brucei rhodesiense. However, subjects of African ancestry carrying APOL1 risk alleles are at an increased risk of developing focal segmental glomerulosclerosis (FSGS) and end-stage renal disease (ESRD). Given that most primates lack APOL1 orthologs and the lack of phenotypes in individuals carrying APOL1 null alleles, we hypothesized that G1-APOL1 and G2-APOL1 are gain-of-function variants. We generated transgenic Drosophila bearing either the wild-type (G0), G1 or G2 forms of human APOL1. Our findings established that the major intracellular localization of APOL1 protein in fly was the endoplasmic reticulum (ER). APOL1 risk variants induced severe ER stress in Drosophila wing disc cells by specifically activating the IRE1- Xbp1-dependent branch of ER stress signaling. With persistent induction of ER stress in wing disc cells, excessive apoptosis was triggered. Importantly, both a genetic approach silencing Xbp1 gene expression and a pharmacological method applying ER stress inhibitor 4-Phenyl butyric acid (4-PBA) successfully rescued APOL1-related apoptosis in Drosophila larvae. Our data from mammalian cells demonstrated similar results. Administration of interferon gamma resulted in upregulation of endogenous APOL1 protein levels in cultured human podocytes. Overexpression of either of the APOL1 risk variants in HEK293T cells caused significant ER stress. The using of 4-PBA effectively relieved ER stress, suggesting that ER stress is the essential step of cytotoxicity related to APOL1 risk variants.Taken together, these findings shed light on the pathogenesis of APOL1-assocaited nephropathy and present an important animal model for future therapeutic studies
Loss of cilia in primary ciliated cells and multiciliated cells
No full textCilia are evolutionary conserved microtubule-based organelles that project from the cell surface and in which microtubules are nucleated from a modified centriole called the basal body. The presence and functions of cilia have to be well controlled to ensure normal development and organismal health. Indeed, cilia are dynamic structures, and depending on the cell type, cell cycle state and extracellular conditions, they can be removed via disassembly or shedding. For example, cilia can be stably present in quiescent primary ciliated cells and be disassembled when cells re-enter the cell cycle. It is widely considered impossible for MCCs to re-enter their cell cycle and to lose their cilia because of their high degree of specialized differentiation. However, loss of MCCs as well as MCCs with reduced ciliation and cilia loss were observed in human pulmonary conditions and in the embryonic Xenopus mucociliary epidermis during metamorphosis. Thus, it remains unresolved how and why MCCs are lost in these conditions and whether MCCs lose their cilia via disassembly.In the present thesis work, the molecular and cellular mechanisms of MCC loss were addressed, and the conservation across cell types of molecular players implicated in cilia loss was investigated. During Xenopus laevis epidermis remodeling prior to metamorphosis, MCCs are lost via lateral line induced apoptosis and via trans-differentiation into secretory goblet-like cells. Both processes are dependent on Notch signaling, while the cellular outcome is modulated by JAK/STAT and thyroid hormone signaling. Trans-differentiation is executed through the loss of ciliary gene expression such as pcm1 and foxj1, initiation of mucus production and secretion, remodeling and loss of basal bodies, and mechanisms resembling primary cilia disassembly, such as cilia shortening, axonemal microtubule de-acetylation, PCM1 loss and loss of cell cycle block. Furthermore, this thesis work investigated a conserved role for the centrosomal protein CP110 in cilia loss. In primary cilia undergoing cilia disassembly, CP110 accumulates at the ciliary base and within the ciliary compartment. Its dynamic localization depends on known primary cilia disassembly factors AURKA and PLK1. Additionally, CP110 is found at the ciliary tip of Xenopus epidermal MCCs that have short cilia or/and are over-expressing PLK1.In summary, the data presented in this thesis demonstrate that Xenopus epidermal MCCs can be lost via cell death or trans-differentiation into a non-ciliated cell type (goblet-like cells), and argued for a common mechanism of cilia loss across ciliated cell types in vertebrates by suggesting a novel conserved role of CP110 in cilia loss in primary ciliated cells and multiciliated cells
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