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WS2.4 Pseudomonas aeruginosa capability to colonize the CF lung may be favored by its remarkable ability to recruit zinc under conditions of limited metal availability
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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
Zinc is required to ensure the expression of flagella and the ability to form biofilms in: Salmonella enterica sv Typhimurium
Full text linkZinc is known to play a central role in bacterial physiology and pathogenesis. Here, we report that the accumulation of FliC, the structural subunit of Salmonella phase 1 flagella, is sharply reduced in a znuABC Salmonella enterica sv. Typhimurium strain grown in zinc-poor media. Consequently, this mutant strain lacks motility, unless it grows in zinc-replete environments. This phenotype is the consequence of a general downregulation of all the genes involved in the biosynthesis of flagella, suggesting that zinc is the cofactor of proteins involved in the initiation of the transcriptional regulatory cascade leading to flagella assembly. Competition experiments in mice demonstrated that aflagellated (fliBfljC) and znuABC strains are outcompeted by the wild type strain in the gastrointestinal tract. The fliBfljC strain overgrows a fliCfljBznuABC mutant strain, but the difference in gut colonization between these two strains is less striking than that between the wild type and the znuABC strains, suggesting that the downregulation of flagella contributes to the loss of virulence of Salmonella znuABC. The absence of either flagella or ZnuABC also impairs the ability of S. Typhimurium to produce biofilms. Zinc suppresses this defect in the znuABC mutant but not in the aflagellated strains, highlighting the role of flagella in biofilm organization. We have also observed an increased production of the quorum sensing signal AI-2 in the znuABC strain sensing zinc deprivation, that may further contribute to the reduced ability to form biofilms. On the whole, our study reveals novel roles of zinc in Salmonella motility and intercellular communication
S. Typhimurium and S. Typhimurium Monophasic variant attenuated vaccines. A comparison of efficacy in homologous and heterologous infection in piglets
No full textIntroduction: Salmonella Typhimurium and its monophasic variant (S. Typhimurium 1, 4, [5], 12:i-) are increasingly responsible of food borne infections in
humans and pork represents the principal source of infection. Infection is generally sub-clinical in pigs and carrier pigs could introduce bacteria in the
slaughterhouse. The aim of the study was to test the efficacy and safety of an attenuated vaccine of S. Typhimurium 1, 4, [5], 12:i- (S. Typhimurium
Monophasic variant ΔznuABC) during an homologous and heterologous infection, with a field isolated strain of S. Typhimurium. The efficacy and safety of
S. Typhimurium Monophasic variant ΔznuABC was compared to an attenuated strain of S. Typhimurium (S. Typhimurium ΔznuABC).
Materials and Methods: Twenty eight weaned piglets were divided in 3 groups and acclimatized for a week. Group T was composed of 8 piglets vaccinated
with an oral administration of S. Typhimurium ΔznuABC at the final dose of 5 х 107 CFU. Group M was composed of 10 piglets vaccinated with an oral
administration of S. Typhimurium Monophasic variant ΔznuABC at the final dose of 5 х 107 CFU. Group C was composed of 10 unvaccinated piglets. At
day 35 after vaccination, all piglets were challenged by an oral gavage with 5 х 108 CFU of S. Typhimurium Monophasic variant or S. Typhimurium.
Particularly, piglets from group T were divided in 2 groups: 3 piglets were infected with S. Typhimurium, the other 5 piglets were infected with S.
Typhimurium 1, 4, [5], 12:i-. Piglets from group M were divided in 2 groups: 5 piglets were infected with S. Typhimurium. The other 5 piglets were infected
with S. Typhimurium 1, 4, [5], 12:i-. Unvaccinated piglets were divided in 2 groups: 5 piglets were infected with S. Typhimurium, the other 5 piglets were
infected with S. Typhimurium 1, 4, [5], 12:i-. Analyzed parameters were weight, temperature, fecal shedding and organ colonization.
Results: In control groups, the amount of S. Typhimurium in feces tends to be higher than S. Typhimurium 1, 4, [5], 12:i- from challenge to the end of the
trial and temperature was significantly different at day 1 after infection indicating that S. Typhimurium was more virulent than S. Typhimurium 1, 4, [5], 12:i-.
The safety of vaccine strains was monitored analyzing fecal shedding and growth of animals.
Conclusion: Attenuated vaccines were safe, in fact they were not isolated in feces after three weeks from vaccination and did not affected growth of
animals. Furthermore, both attenuated vaccines reduced the shedding of virulent strains in comparison to unvaccinated groups and S. Typhimurium
ΔznuABC appeared more effective in homologous and heterologous challenge infections
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
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
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