1,721,043 research outputs found
Latest Developments of Research on the Viable Non-Culturable State of L. monocytogenes and Implications for Food Safety
No full textFeatured Application: This review article aims to collect updated knowledge on the conditions that induce the viable non-culturable (VBNC) state in the foodborne pathogen Listeria monocytogenes, obtain indications on practices that can prevent the occurrence of this form of the pathogen in food, and identify aspects that necessitate further investigation. This descriptive review summarizes the most recent findings on the induction and distribution of viable non-culturable (VBNC) Listeria monocytogenes in food production conditions and food. The aim was to obtain information on the factors that favor the transition to the VBNC state in L. monocytogenes; its resuscitation capacity; and, according to scientific articles published since 2020, how food contamination by the bacterium in a VBNC state can be prevented. The methods used for VBNC L. monocytogenes detection were also reviewed. A few studies reported the presence of VBNC L. monocytogenes in food, in which fresh produce and chicken meat were considered. Different physicochemical stresses such as exposure to disinfectants with diverse actions and essential oils, desiccation, low temperatures, absence of nutrients, high NaCl and iron concentrations, and low pH adjusted with acetic acid were reported to induce the VBNC state in L. monocytogenes. The VBNC forms of L. monocytogenes were able to regain growth and virulence. This could pose a safety risk that cannot be revealed by the standard culture-dependent methods recommended for L. monocytogenes detection. Therefore, the presence in food and food production plants of VBNC L. monocytogenes should be prevented by the appropriate use of hurdles and cleaning/disinfection procedures. The opportunity to harmonize VBNC cell detection methods for regular use in food safety evaluation also emerged
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
Study of Listeria monocytogenes: a proteomic and transcriptomic approach
No full textListeriosis is a zoonosis caused by Listeria monocytogenes, which is a foodborne pathogen posing a significant health risk, especially to individuals with weakened immune systems, including pregnant women, newborns, young children, and the elderly. The consumption of several food products has been linked to numerous outbreaks, including raw milk, soft cheeses, processed meats, seafood, and ready-to-eat foods like salads and raw vegetables. One of the concerning aspects of L. monocytogenes is its ability to thrive and reproduce in a wide range of environmental conditions, which poses challenges for food safety and contamination control. This adaptability allows the pathogen to persist in conditions with low pH, refrigeration temperatures, and high salt concentrations [1].
The following study aims to identify differentially expressed genes and pathogenic proteins encoded by L. monocytogenes during its exposure to stress growth conditions (37°C, 0.5%, pH 7 vs A2 - 12°C, 7.0%, pH 5.5). Bacterial cells were collected during late exponential growth phase to extract, purify and quantify RNA and protein samples as well. Transcripts were analyzed by RNAseq technique while proteins by nLC-MS/MS approach. Proteins identification required a minimum of 2 peptides per protein against the L. monocytogenes Uniprot database. Differential expression results were obtained by TopHat and Cufflinks software and were correlated with proteomic data, which were analyzed and clustered using an immunoinformatic pipeline and STRING v11.05, respectively.
By the analysis performed it was identified a specific panel of genes which encoded for several specific proteins associated with cold tolerance (lmo0823), acidic (lmo2005) and oxidative stress. Furthermore all the proteins identified are involved in pathogenic and virulent pathways and most of them are well known to be regulated by Prfa gene (lmo2157).
These results are supported by prior literature reports and could be useful for future research focused on understanding the pathogenesis of listeriosis
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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