1,721,004 research outputs found

    The role of serine/threonine kinases in translation machinery regulation and antibiotic susceptibility in response to nutrient starvation in <i>Pseudomonas aeruginosa</i>

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    Pseudomonas aeruginosa is a gram-negative opportunistic pathogen that produces highly antibiotic-tolerant biofilms that create an enormous therapeutic burden as they cause many types of chronic infections. The reason P. aeruginosa biofilms are problematic is in part due to reduced growth activity and downregulation of metabolic processes within biofilms that are typically the target of antibiotics. There is an unmet need for novel strategies that aim to either disrupt the biofilm itself or modulate metabolic activity and cell survical mechanisms within biofilms. A relatively unexplored mechanism for disrupting the metabolic adaptability of P. aeruginosa is via inhibition of serine/threonine phosphorylation pathways of eukaryote-like serine/threonine kinases in biofilms. These kinases are characterised by a catalytic Hanks-type domain that reversibly phosphorylates serine or threonine residues of various proteins in many cellular processes, including several regulatory proteins of other signalling cascades. The focus of this study was to investigate the role of eSTK’s in P. aeruginosa biofilm development and their impact on metabolism and adaptive responses. There are four eSTK’s in the P. aeruginosa genome. All four of these genes were deleted from PAO1 individually and sequentially to produce a quadruple knockout mutant termed QKO. In addition, three were deleted individually from P. aeruginosa PA2192, a cyctic fibrosis clinical isolate. Using multiple strategies such as confocal microscopy and TMT-labelled proteomics analysis we showed that deletion of a single eSTK, YeaG, of PA2192 can inhibit aggregate formation, and that the metabolic adaptability of the QKO mutant of PAO1 is significantly disrupted and which leads to major alterations within intracellular signalling pathways. This leads to a compromised membrane phenotype that allows greater influx of positively charged compounds such as propidium iodide. Although we did not see any increase in the susceptibility of the QKO mutant to tobramycin in the model used, the apparent cellular stress exhibited by the QKO mutant and the inhibited aggregation of the PA2192 suggest that eSTK’s are potentially interesting drug targets with therapeutic potential in the control of P. aeruginosa biofilms

    Step A: Culturing

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    Culturing step for bacterial genome resequencing projec

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

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    We 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

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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
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