1,720,961 research outputs found
Social networks in the gut : Acyl-Homoserine Lactones, Quorum Sensing molecules, modulate gut inflammation
No full textLes N-Acyl-Homoserine Lactones (AHLs) sont des molécules du Quorum Sensing impliquées dans le réseau de communication inter-bactérien et peuvent également être reconnues par les cellules eucaryotes dans le cadre du dialogue inter-règne. Notre équipe a récemment mis en évidence la présence d'une AHL, la 3-oxo-C12:2-HSL, diminuée dans l'écosystème intestinal des patients atteints de maladies inflammatoires chroniques de l’intestin (MICI). L’objectif de ce travail de thèse était d’étudier les effets de cette molécule naturelle et d’un analogue synthétique, l’ACP, sur l’inflammation et l’écosystème intestinal. Nous avons démontré que ces AHLs exercent des effets anti-inflammatoire sur les cellules immunitaires. Par analyse transcriptomique, nous avons identifié la voie JAK-STAT était impliquée. La phosphorylation des protéines JAK1 et STAT1 étaient diminuée en présence de la 3-oxo-C12:2-HSL. Par ailleurs, nous avons identifié des potentiels récepteurs de la 3-oxo-C12:2-HSL, les récepteurs du goût amer, dont T2R38. Les effets modulo-inflammatoires de la 3-oxo-C12:2-HSL étaient abolis en présence d’un inhibiteur allostérique de T2R138 et sept autres récepteurs du goût amer étaient activés, lors d'un screening de tous ces récepteurs connus humains. En conclusion, les AHLs sont des nouveaux acteurs de l’interaction hôte microbiote et leur étude constitue une nouvelle piste dans la physiopathologie des MICI.N-Acyl-Homoserine Lactones (AHLs) are Quorum Sensing molecules involved in bacterial network communication and are also able to have effects on eukaryotic cells as part of the inter-kingdom signalling. Our team identified AHLs in the gut ecosystem, and among them one that had never been described, 3-oxo-C12:2-HSL. The molecule was decreased in the gut ecosystem of Inflammatory Bowel Disease (IBD) patients. The aim of my PhD was to study the effects of the natural molecule 3-oxo-C12:2-HSL and ACP, a synthetic analogue, on intestinal inflammation as well as involved mechanisms and prospective eukaryotic receptors. We demonstrated that those AHLs exert anti-inflammatory effects on immune cells. By transcriptomic analysis, we identified the involvement of the JAK-STAT pathway. Phosphorylation of JAK1 and STAT1 proteins was decrease when cells were treated with 3-oxo-C12:2-HSL. Besides, we identified potential receptors of 3-oxo-C12:2-HSL, the bitter taste receptors, including T2R138. The immune-modulatory effects of, 3-oxo-C12:2-HSL were abolished when T2R138 was inhibited. Seven other bitter taste receptors were activated by 3-oxo-C12:2-HSL but not ACP, as observed by a screening of all the known human bitter taste receptors. To conclude, AHLs are new actors in host-microbiota interactions and their study is a new lead in the IBD physiopathology
Réseaux sociaux dans l'intestin : les Acyl-Homosérine Lactones, molécules du Quorum Sensing, modulent l'inflammation intestinale
No full textN-Acyl-Homoserine Lactones (AHLs) are Quorum Sensing molecules involved in bacterial network communication and are also able to have effects on eukaryotic cells as part of the inter-kingdom signalling. Our team identified AHLs in the gut ecosystem, and among them one that had never been described, 3-oxo-C12:2-HSL. The molecule was decreased in the gut ecosystem of Inflammatory Bowel Disease (IBD) patients. The aim of my PhD was to study the effects of the natural molecule 3-oxo-C12:2-HSL and ACP, a synthetic analogue, on intestinal inflammation as well as involved mechanisms and prospective eukaryotic receptors. We demonstrated that those AHLs exert anti-inflammatory effects on immune cells. By transcriptomic analysis, we identified the involvement of the JAK-STAT pathway. Phosphorylation of JAK1 and STAT1 proteins was decrease when cells were treated with 3-oxo-C12:2-HSL. Besides, we identified potential receptors of 3-oxo-C12:2-HSL, the bitter taste receptors, including T2R138. The immune-modulatory effects of, 3-oxo-C12:2-HSL were abolished when T2R138 was inhibited. Seven other bitter taste receptors were activated by 3-oxo-C12:2-HSL but not ACP, as observed by a screening of all the known human bitter taste receptors. To conclude, AHLs are new actors in host-microbiota interactions and their study is a new lead in the IBD physiopathology.Les N-Acyl-Homoserine Lactones (AHLs) sont des molécules du Quorum Sensing impliquées dans le réseau de communication inter-bactérien et peuvent également être reconnues par les cellules eucaryotes dans le cadre du dialogue inter-règne. Notre équipe a récemment mis en évidence la présence d'une AHL, la 3-oxo-C12:2-HSL, diminuée dans l'écosystème intestinal des patients atteints de maladies inflammatoires chroniques de l’intestin (MICI). L’objectif de ce travail de thèse était d’étudier les effets de cette molécule naturelle et d’un analogue synthétique, l’ACP, sur l’inflammation et l’écosystème intestinal. Nous avons démontré que ces AHLs exercent des effets anti-inflammatoire sur les cellules immunitaires. Par analyse transcriptomique, nous avons identifié la voie JAK-STAT était impliquée. La phosphorylation des protéines JAK1 et STAT1 étaient diminuée en présence de la 3-oxo-C12:2-HSL. Par ailleurs, nous avons identifié des potentiels récepteurs de la 3-oxo-C12:2-HSL, les récepteurs du goût amer, dont T2R38. Les effets modulo-inflammatoires de la 3-oxo-C12:2-HSL étaient abolis en présence d’un inhibiteur allostérique de T2R138 et sept autres récepteurs du goût amer étaient activés, lors d'un screening de tous ces récepteurs connus humains. En conclusion, les AHLs sont des nouveaux acteurs de l’interaction hôte microbiote et leur étude constitue une nouvelle piste dans la physiopathologie des MICI
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
Impact of N-Acyl-Homoserine Lactones, Quorum Sensing Molecules, on Gut Immunity
No full textInternational audienceAmong numerous molecules found in the gut ecosystem, quorum sensing (QS) molecules represent an overlooked part that warrants highlighting. QS relies on the release of small molecules (auto-inducers) by bacteria that accumulate in the environment depending on bacterial cell density. These molecules not only are sensed by the microbial community but also interact with host cells and contribute to gut homeostasis. It therefore appears entirely appropriate to highlight the role of these molecules on the immune system in dysbiosis-associated inflammatory conditions where the bacterial populations are imbalanced. Here, we intent to focus on one of the most studied QS molecule family, namely, the type I auto-inducers represented by N-acyl-homoserine lactones (AHL). First described in pathogens such as Pseudomonas aeruginosa, these molecules have also been found in commensals and have been recently described within the complex microbial communities of the mammalian intestinal tract. In this mini-review, we will expound on this emergent field of research. We will first recall evidence on AHL structure, synthesis, receptors, and functions regarding interbacterial communication. Then, we will discuss their interactions with the host and particularly with agents of the innate and adaptive gut mucosa immunity. This will reveal how this new set of molecules, driven by microbial imbalance, can interact with inflammation pathways and could be a potential target in inflammatory bowel disease (IBD). The discovery of the general impact of these compounds on the detection of the bacterial quorum and on the dynamic and immune responses of eukaryotic cells opens up a new field of pathophysiology
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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