1,720,967 research outputs found
Cell wall components of a Lactobacillus brevis strain inhibit herpes simplex virus type 2 replication
No full textBacteria-free supernatant of Lactobacillus brevis strain CD2 grown in cell culture medium inhibits herpes simplex virus type 2 (HSV-2) replication in cell culture independently from H2O2 or lactic acid. The mechanisms of action and the bacterial factors responsible for the antiviral effect were studied using bacterial extracts obtained by sonication of L. brevis cells or by lysozyme/antibiotic treatment of the microorganism. The antiviral activity of bacterial cell wall was also studied. Bacterial extract and cell wall were not toxic to cells at the maximal concentration tested (3 mg/ml protein). Both the extract and the cell wall fraction showed a dose-dependent inhibitory activity on HSV2 multiplication when present on Vero cells before virus adsorption and during infection.
The inhibition was exerted on the first phases of virus replication cycle. The inhibitory activity was resistant to a 30 minutes treatment at 100°C. DNA and lipids obtained from bacterial extract were devoid of any inhibitory effect. S-layer of bacterial cell-wall containing several heat-resistant molecules (teichoic and lipoteichoic acids, lipoglycans, teichuronic acids and other acidic or neutral polysaccharides) was removed by treatment with LiCl without affecting bacterial viability. Bacterial extract and cell-wall fragments obtained after LiCl treatment showed a dramatic reduction in the antiviral activity suggesting that cell wall components of L. brevis released in bacterial supernatant after sonication or lysozyme/antibiotic treatment are responsible for the inhibiting activity against HSV-2
VSL#3 probiotic maternal supplementation affects breast milk composition and newborn faeces microbiota
No full textThe infant’s microbiota is acquired during the perinatal period through direct contact with the maternal microbiota during and after delivery. Breastfeeding has been suggested to enrich vaginally acquired lactic acid-producing bacteria of the neonatal gut since the human milk contains viable lactobacilli and bifidobacteria. Microbiological and immunological investigations were performed in order to evaluate the changes induced by VSL#3 probiotic maternal supplementation on breast milk and newborn faeces. Maternal milk was analyzed for factors known to modulate immunological characteristics and the developing microbiota within the gastrointestinal tract (probiotic bacteria, cytokines and immunoglobulins). The functional effects of maternal probiotic intervention on the newborn health were assessed evaluating stool composition in terms of lactobacilli and bifidobacteria content. This pilot double-blind, randomized, placebo-controlled clinical trial enrolled 35 healthy pregnant women four weeks before expected delivery. Participants received daily oral probiotic or placebo supplementation starting from the enrolment until four weeks after delivery. At 3 (T0) and 30 (T30) days after birth, infant stools and milk samples were collected. The amount of lactobacilli and bifidobacteria in breast milk of probiotic treated group was higher compared to controls. However due to the high individual variability of bacterial concentration, this increase did not resulted statistically significant. Noteworthy, the concentration of lactobacilli tended to be higher in the colostrum of the mothers in the probiotic group as compared with those on placebo (p =0.099). At birth the amount of lactobacilli in feces of neonates from VSL#3-treated mothers was significantly higher than in control group (p <0.05). In these samples, the concentration of bifidobacteria tended to be higher as compared with those on placebo. No differences in the presence of VSL#3 Lactobacillus and Bifidobacterium species were observed between groups in both milk and faecal samples. Therefore, our microbiological results exclude a direct colonization of the mammary gland by the supplemented VSL#3 probiotic strains through a suggested migration from the intestine to the lactating mammary gland. TGF-ß values were significantly higher in colostrum from probiotic group in comparison to the control group and increased significantly at T30 only in the probiotic group. IL10 levels were significantly higher in the mature milk from probiotic treated group and IgA levels were significantly higher in colostrum and mature milk from probiotic group. These results suggest that VSL#3 could represent a good supplementation in the diet of pregnant women
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
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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