1,721,056 research outputs found
A provisional Transcriptional Regulatory Network for the obliged human pathogen Helicobacter pylori
No full textTo adapt to a particular host niche, bacterial pathogens rely on Transcriptional Regulatory Networks (TRNs) that transduce environmental signals into coordinated output expression of virulence factors and housekeeping genes. In virtue of its remarkable paucity of transcriptional regulators, the human gastric pathogen Helicobacter pylori represents a very appealing model system to understand how bacterial TRNs are wired up to govern multiple responses with few regulatory factors. The TRN of H. pylori emerges as a multi-layer hierarchical structure composed of 20 regulators organized in four main regulatory modules (origons), which process related physiological responses needed to colonize the gastric niche: respectively heat and stress response, motility and chemotaxis, acidic and metal ion homeostasis. Experimental verification and logic analysis of the TRN uncovered specific motifs, or patterns of interconnection, between regulators and target genes, which confer distinct response dynamics to the circuit. For example, the stress response origon adopts two regulators, HspR and HrcA, which result to be wired in a rare incoherent Feed-Forward Loop motif, responsible for accelerated response kinetics of GroESL chaperone expression. The flagellar circuit appears essentially as sigma regulatory cascade, where each sigma regulates transcription of a dedicated flagellar gene class with Single Input Motif circuitry, while two metal-dependent regulators, Fur and NikR, appear to operate through a central Bifan motif, connecting the metal responses in a symmetric coordination logic with no obvious hierarchy. Finally, the interconnections between the modules are presented, such as the acid acclimation origon controlled by the response regulator ArsR, whose transcription levels are in turn directly regulated by Fur. The results provide the first provisional description of a TRN for an important human pathogen
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
First comes the A, then the B: what we learned from the COVID-19 outbreak
No full textThe SARS-CoV-2 epidemic, which has spread to many countries around the world, has hit Europe particularly hard. From our point of view, in a rural emergency department (with an annual patient census of around 25,000) in northeastern Italy, it is necessary to preserve the hospital and prevent it from becoming an outbreak of infection. In our experience, we reevaluated the negative predictive value of lung ultrasound to rule out lung involvement. Since severe acute respiratory failure appears to be the leading cause of death for COVID-19 patients, it is essential to focus on this clinical feature. We currently believe that a patient suspected of COVID-19, if he has a normal ultrasound examination (a so-called "A-profile"), can be discharged home to continue isolation and be treated without being hospitalized
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
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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