1,720,975 research outputs found
Gut microbiota and gastric disease
No full textThe gut microbiota may be considered a crucial "organ" of human body because of its role in the maintenance of the balance between health as well as disease. It is mainly located in the small bowel and colon, while, the stomach was long thought to be sterile in particular for its high acid production. In particular, stomach was considered "a hostile place" for bacterial growth until the identification of Helicobacter pylori (HP). Now, the stomach and its microbiota can be considered as two different "organs" that share the same place and they have an impact on each other. Indeed, microscopic structures of gastric mucosa (mucus layer and luminal contents) influence local microflora and vice versa. In this article our attention is directed specifically to explain the effects of this "cross-talk" on gastric homeostasis. Gastric microbiota mainly consists of two general groups, namely HP and non-HP bacteria. Here, the relationship between these two populations will be reviewed, focusing on their role in the development of the different gastric disorders, i.e. functional dyspepsia, gastric premalignant lesions (chronic atrophic gastritis, intestinal metaplasia and dysplasia of the gastric mucosa) and gastric cancer. Moreover, we focus on the effects on the gastric microbiota of exogenous interference as diet and use of proton pump inhibitors (PPIs)
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
Inflammatory Bowel Diseases: The Role of Gut Microbiota
No full text: Inflammatory bowel diseases (IBD) are chronic multifactorial diseases characterized by partially unclear pathogenic mechanisms including changes in intestinal microbiota. Despite the microbiota, alteration is well established in IBD patients, as reported by 16RNA sequencing analysis, an important goal is to define if it is just a consequence of the disease progression or a trigger factor of the disease itself. To date, gut microbiota composition and gut microbiota-related metabolites seem to affect the host healthy state both by modulating metabolic pathways or acting on the expression of different genes through epigenetic effects. Because of this, it has been suggested that intestinal microbiota might represent a promising therapeutic target for IBD patients. The aim of this review is to summarize both the most recent acquisitions in the field of gut microbiota and its involvement in intestinal inflammation together with the available strategies for the modulation of microbiota, such as prebiotics and/or probiotics administration or fecal microbiota transplantation
Gut-Brain Axis in Gastric Mucosal Damage and Protection
No full textThe gut-brain axis plays a potential role in numerous physiological and pathological conditions. In particular, there are several substances and a dense neuronal network that link stomach with Central Nervous System (CNS). Several communication mechanisms involve spinal and vagal system. In particular, hypothalamo-pituitary-adrenocortical (HPA) axis, thyrotropin-releasing hormone (TRH)-containing nerve fibers and capsaicin-sensitive nerves are principal mediators of the harmful and protective CSN-mediated effects on gastric mucosa. Also, existing evidence indicates that nitric oxide (NO), prostaglandins (PGs) and calcitonin gene-related peptide (CGRP) play a role as final effectors of gastric protection. This review is focused on the role of gut-brain axis in gastric damage and protection and, in particular, on the role of steroids, TRH, PGs, melatonin, hydrogen sulfide (H2S) and peptides influencing food intake (leptin, cholecystokinin (CCK), peptide YY, central glucagon-like peptide-1 [GLP-1], ghrelin). Also, the role of GABAergic and glutamatergic pathways in gastric mucosal protection have been examined
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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