1,721,013 research outputs found
Static and dynamic in vitro colonic models reveal the spatiotemporal production of flavan-3-ol catabolites
No full textFlavan-3-ols are the most found flavonoid compounds in the human diet. Polymeric and monomeric flavan-3-ols reach the colonic region intact, where the gut microbiota utilizes them as substrates. In this research work, we investigated the pattern of colonic metabolites associated with flavan-3-ols, conducting a comprehensive analysis that combined (un)targeted metabolomics and in vitro colonic models. Firstly, the proposed flavan-3-ol metabolic pathway was investigated in-depth using a static in vitro model inoculated with different fecal donors. An apple, (−)-epicatechin, and procyanidin C1 were employed as feeding conditions. Small phenolic acids, such as phenylpropanoic acid and 3,4-dihydroxybenzoic acid, were positively associated with the apple feeding condition. In contrast, 5-(3ʹ,4ʹ-dihydroxyphenyl)-γ-valerolactone and other specific early intermediates like phenylvaleric acids were positively associated with (−)-epicatechin. Secondly, by employing a dynamic in vitro simulator model of the human digestion system (SHIME), we reconstructed the flavan-3-ol metabolic pathway regionally. In the proximal colon region, we localized catabolites, such as 5-(3ʹ,4ʹ-dihydroxyphenyl)-γ-valerolactone, while in the distal region, we identified mainly small phenolics. Combining static and dynamic in vitro models, we observed differences in the release of flavan-3-ol catabolites, influenced by both the food structure (isolated compounds and a food matrix) and the colonic region. This study sheds light on the colonic catabolism of one of the main dietary (poly)phenols and localizes microbial metabolites
Decoding microbial volatile signals in host–microbiome crosstalk
No full textThe human gut microbiome is a complex microbial ecosystem which has a profound impact on host health and disease. The research focus in this area is rapidly moving from taxonomy to functionality, elucidating the biological role of small molecules produced by the gut microbiome in regulating host metabolism. Among these, microbial volatile organic compounds (mVOCs) play several roles in bacterial communication and microbe-host signaling. Volatilomics, the comprehensive study of volatile metabolites, is emerging as a powerful tool for discovering and investigating these interactions. In this review we examine the current understanding of mVOCs in the gut and highlight how dedicated in vitro and ex vivo volatilomics experiments, alongside in vivo studies, can uncover the biological roles for these emerging small molecule
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
Fusarium verticillioides and F. proliferatum from Syrian wheat grains: fumonisin production
No full textFusarium species are predominantly found associated with Fusarium head blight in wheat and other small-grain cereals all over the world. F. verticillioides (Fv) and F. proliferatum (Fp), the less frequently encountered species, are less pathogenic but toxigenic. The occurrence of these species in harvested wheat and cereals grains could indicate the presence of fumonisin mycotoxins. The risks of the consumption of fumonisin contaminated grains must not be ignored. In Syria, wheat is the main strategic crop and its two main products, bread and bulgur, are common food stuffs. The average consumption of bread per capita per month is 12.9 Kg.
The aim of the study was to detect the presence of fumonisins in Syrian wheat grains and the ability of Fv and Fp in their production.
Fourty-eight grain samples of durum and soft wheat were collected from different Syrian areas during years 2009 and 2010. Mycological analysis was performed on four hundred kernels for each sample. All Fusarium isolates were studied morphologically and molecularly, and then screened for their ability in producing mycotoxins in wheat cultivation. Fusarium infected samples were analyzed also for mycotoxin content using HPLC–MS/MS.
The data revealed that F. verticillioides and F. proliferatum were present in Syrian wheat grains with frequencies of 10.4% and 8.0%, respectively towards the total of Fusarium population. All the strains were able to produce fumonisins B1, B2, B3 (FB1, FB2, FB3), and 10 % of the grain samples were contaminated with low levels of FB1, FB2
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
- …
