1,720,994 research outputs found
Susceptibility to chlorhexidine in multidrug resistant clinical isolates of Staphylococcus epidermidis from bloodstream infections
The emergence of Staphylococcus isolates with reduced susceptibility to chlorhexidine is being increasingly
reported.We present an update to a previous report showing the continuing efficacy of chlorhexidinebased
infection control measures against Staphylococcus aureus over 6 years. In this study, qacA/B genes
were screened in Staphylococcus isolates collected over another 6 years in the same intensive care unit
in Scotland where chlorhexidine baths form an essential component of long-term control of nosocomial
infections. Consistent with our previous study, we report minimal presence of qacA/B in S. aureus
strains from screening samples and bacteraemia patients but the new finding of a high proportion of
qacA/B carriage in Staphylococcus epidermidis associated with reduced susceptibility to chlorhexidine.
S. epidermidis isolates positive for qacA/B were clonally diverse, although 65% of isolates belonged to the
multidrug-resistant (MDR) clone ST2. These findings raise concerns in relation to the selection of MDR
strains by chlorhexidine and are important in the context of recent evidence emphasising the benefits
of targeting bloodstream infections associated with coagulase-negative staphylococci
Management ofserious meticillin-resistant Staphylococcus aureus infections: what are thelimits?
Going Beyond Counting First Authors in Author Co-citation Analysis
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
Phylogenetic analysis of resistance to ceftazidime/avibactam, ceftolozane/tazobactam and carbapenems in piperacillin/tazobactam-resistant Pseudomonas aeruginosa from cystic fibrosis patients
Pseudomonas aeruginosa is one of the most important pathogens in cystic fibrosis. This study was con- ducted to analyse the genetic basis and phylogenetic profile of resistance to ceftazidime/avibactam, ceftolozane/tazobactam and carbapenems in cystic fibrosis P. aeruginosa isolates. Whole genome sequence analysis was conducted of isolates resistant to piperacillin/tazobactam collected from seven hospitals in Scotland since the introduction of these two cephalosporin/ β-lactamase inhibitor combinations. Cef- tazidime resistance was primarily related to AmpC induction, as tested by cloxacillin inhibition assays, while high-level ceftazidime resistance not reversed by cloxacillin was associated with amino acid varia- tions in AmpC. Only isolates resistant to both ceftazidime/avibactam and ceftolozane/tazobactam carried AmpD mutations, likely resulting in ampC overexpression. All isolates resistant to ceftazidime/avibactam and/or ceftolozane/tazobactam were resistant to carbapenems and showed inactivating mutations in the chromosomal oprD gene. None of the isolates bore class A, B, D plasmid-encoded carbapenemases. This study showed that mutational resistance emerged in phylogenetically distant lineages, which indicates the mutations occur independently without conferring a selective advantage to any phylogenetic lineage. These findings confirm the strong contribution of mutation-driven evolution to the population structure of P. aeruginosa
Newinsights into meticillin-resistant Staphylococcus aureus (MRSA) pathogenesis,treatment and resistance.
Variations on the Author
“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
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
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
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