1,720,958 research outputs found
Ceftazidime-avibactam resistance in Klebsiella pneumoniae sequence type 37: a decade of persistence and concealed evolution
Get PDFThe first reports of carbapenem-resistant Enterobacterales in our hospital date back to 2006. In that period, few ertapenem-resistant but meropenem-susceptible Klebsiella pneumoniae isolates belonging to sequence type (ST) 37 were retrieved from clinical samples. These strains produced the CTX-M-15 extended spectrum β-lactamase, OmpK35 was depleted due to a nonsense mutation, and a novel OmpK36 variant was identified. Yet, starting from 2010, Klebsiella pneumoniae carbapenemase (KPC)-producing ST512 isolates started prevailing and ST37 vanished from sight. Since 2018 the clinical use of the combination of ceftazidime-avibactam (CZA) has been introduced in clinical practice for the treatment of bacteria producing serine-β-lactamases, but KPC-producing, CZA-resistant K. pneumoniae are emerging. In 2021, four CZA-resistant ST37 isolates producing KPC variants were isolated from the same number of patients. blaKPC gene cloning in Escherichia coli was used to define the role of those KPC variants on CZA resistance, and whole genome sequencing was performed on these isolates and on three ST37 historical isolates from 2011. CZA resistance was due to mutations in the blaKPC genes carried on related pKpQIL-type plasmids, and three variants of the KPC enzyme have been identified in the four ST37 strains. The four ST37 isolates were closely related to each other and to the historical isolates, suggesting that ST37 survived without notice in our hospital for 10 years, waiting to re-emerge as a CZA-resistant K. pneumoniae clone. The ancestor of these contemporary isolates derives from ST37 wild-type porin strains, with no other mutations in chromosomal genes involved in conferring antibiotic resistance (parC, gyrA, ramR, mgrB, pmrB)
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
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
Development of a Providencia stuartii multilocus sequence typing scheme
Get PDFIntroductionThe Providencia genus is assuming greater clinical relevance among infections caused by Enterobacterales also because of its intrinsic and acquired resistance to last-resort antibiotics. However, despite having been known and studied for over 50 years, genomics and taxonomy of the Providencia genus are currently undergoing a deep rearrangement. In this study we aim to outline and characterized the P. stuartii species.MethodsWe retrieved from the GenBank database all genomes labelled as Providencia and performed a comprehensive genome-based species definition founded on average nucleotide identity (ANI) and on alignment-free approaches.ResultsAfter defining the genomes assuredly identifiable as P. stuartii, we devised a MultiLocus Sequence Typing (MLST) and a core-genome MLST (cgMLST) schemes, based on 7 and 2,296 loci respectively.DiscussionThis work hence provides a framework for understanding the role of P. stuartii and of other members of this genus, which should be considered as emerging multidrug-resistant pathogens
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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