1,720,967 research outputs found
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
Probiotics in helicobacter pylori infection
No full textThe combination of a proton pump inhibitor and two antibiotics (amoxicillin plus clarithromycin or metronidazole) has been the recommended first-line therapy since the first guidelines for Helicobacter pylori (H. pylori) infection in children. In recent years, the success of eradication therapies has declined, in part due to the development of H. pylori resistant strains. Alternative anti-H. pylori treatments are currently becoming more popular than the traditional eradication methods. In vitro-studies demonstrated an inhibitory activity of probiotics on H. pylori growth and this effect is extremely strain specific. Different biologic effects have been described for probiotics, including the synthesis of antimicrobial substances as lactic acid, hydrogen peroxide and bacteriocins, the competitive interaction with pathogens for microbial adhesions sites and finally the modulation of the immune response of the host. Available data in children indicate that probiotics seem to be efficacious for the prevention of antibiotic associated side-effects, and might be of help for the prevention of H. pylori complications by decreasing H. pylori density and gastritis, and for the prevention of H. pylori colonization or re-infection by inhibiting adhesion to gastric epithelial cells. Components that may be used either as a monotherapy or, in combination with antibiotics, resulting in a more effective anti-H. pylori therapy have been investigated in depth by several researchers. Nevertheless, many questions remain unanswered. In thischapter we discuss the actual knowledge about the effects of the addition of probiotics to H. pylori eradication therapy
Probiotics and inflammatory bowel disease
No full textAlterations in gut microbiota composition appear to be involved in the pathogenesis of several disorders, including inflammatory bowel diseases (IBD). Many biological functions are carried out by the human intestinal flora. In recent times new techniques of analysis have shown that healthy subjects have a different composition of the gut microbiota compared to those with IBD, although the real mechanism of this dysbiosis has not been proved, yet. On this basis, several research studies, controlled trials and meta-analysis have investigated the role of different probiotics in therapeutic management of IBD, suggesting that some kinds of probiotics may be useful, especially in the phase of maintenance of remission. Currently, there are evidence for using some strains of probiotics in quiescent ulcerative colitis and pouchitis by ileal pouchanastomosis, but few reliable data regarding Crohn’s disease. More research is needed to exhaustively understand when and which probiotics are useful in IBD, their mechanisms of action as well as their safety and effectiveness in these diseases
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
Lower GI endoscopy in polyps and polyposis
No full textIntestinal polyps can be classified by their shape or histological aspect and they can be isolated, multiple, or belonging to polyposis syndromes. The most common isolated intestinal polyps in children are the juvenile (hamartomatous) polyps which represent more than 90% of cases. Several polyposis syndromes exist and they are characterized by the presence of numerous polyps in gastrointestinal tract with an increased risk of developing malignancy compared to general population. These syndromes can be divided into hereditary and non-hereditary forms. Clinically, the intestinal polyposis can cause several symptoms such as changes in intestinal habits, abdominal pain, bloody stools, weight loss, and extraintestinal manifestations including benign and malignant neoplasms in various organs such as thyroid, central nervous system, breast, and genital tract. Because of this systemic involvement, the approach to polyposis must include a series of endoscopic, radiological, clinical, genetic and laboratory probes to diagnose early mucosal lesions and establish appropriate follow-up and therapies
Expert commentary: Probiotics and respiratory tract infections
No full textProbiotics are live microorganisms which can confer a health benefit on the host, when administered in adequate amounts. There is increasing evidence that probiotics are able to influence immune response in different sites including the respiratory mucosa. It is not yet known how bacteria modulate immune responses at distant tissue sites but it could depend on the existence of what has been called the “common mucosal immune system," which explains how activated lymphocytes can reach different mucosal sites. In this chapter we have analyzed some reviews regarding the role of probiotics in respiratory diseases. To date there is a weak evidence of the efficacy of probiotics in preventing the upper respiratory tract infections, even if it is not yet clear what is the probiotic strain that is needed to be used, the dosage and the duration of the therapy. Anyway, all studies agree on the need for a greater uniformity of the trials in order to obtain clearer guidance and safer conclusions
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