1,720,973 research outputs found
Degradation of a nylon polyamide fabric by Fusarium sp. [Deterioramento di un tessuto di nailon poliamidico da Fusarium sp.]
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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
Detection of 14C-carmoisine metabolites by high performance liquid chromatography
No full text14C-Carmoisine, a sulphonated azodye, 200 mg/kg b.w. (25 μCi), was administered to rats by gavage. Separation of radioactive compounds in faeces and urine of these animals was carried out by HPLC with a UV and a radioactivity detector. In addition to unmodified carmoisine, five radioactive compounds were present. The main peak showed both the retention time and the UV spectrum of naphtionic acid. Metabolic patterns similar to those observed 'in vivo' were found by incubation of 14C-carmoisine under anaerobic conditions with a bacterial suspension isolated from human faeces and from the intestinal contents of rats. This procedure permits the preparation of amounts of unknown metabolites suitable for their identification
Antimicrobial susceptibility tests on anaerobic oral mixed cultures in periodontal diseases
No full textThe ecosystem of the dental plaque in periodontal diseases is very complex: the study of such micro-organisms, which are mostly strict anaerobes, requires the use of specific techniques under conditions of strict anaerobiosis. The aim of the present study was to design a rapid method to evaluate the activity of antimicrobials on mixed bacterial plaque of subjects with periodontal diseases. The study was carried out using a computerised instrument generally used for simultaneous diagnostic tests with aerobic bacteria. Operative and methodological modifications were made to obtain conditions of strict anaerobiosis and the balanced growth of all the microbial forms present in the mixed cultures of the plaque. Penicillins and cephalosporins were active on all the samples, whereas colistin, gentamicin, kanamycin and nalidixic acid showed no activity Clindamycin, tetracycline, erythromycin and penicillin G were effective only against some samples. The activity of the antimicrobials towards isolated strains was analogous to that towards the corresponding mixed culture
The effects of protein dietary sources on serum cholesterol and bile acid microbiological transformation in rabbits
No full textThe effects of feeding different protein sources on plasma cholesterol and bile acid microbiological transformations has been investigated in rabbits fed casein or soy protein diets. Casein fed rabbits exhibit higher serum cholesterol levels while in vitro observations show an impairment of primary bile acid bacterial 7a- dehydroxylation. The protein dietary source does not seem to modify the microflora composition as long as groups and genera are concerned, however we observed differences in the relative frequencies of some species of Bacteroidaceae: B. thetaiotaomicron, B. distasonis, B. uniformis and B. vulgatus
Oxygen tolerance of anaerobic bacteria isolated from human feces
No full textThe large bowel intestinal flora of mammals is made up mostly of O2-intolerant anaerobic microorganisms which are irreversibly damaged by brief exposure to air. The aim of our work was to investigate the effect of atmospheric O2 on human intestinal anaerobic microorganisms. Thirty O2-intolerant bacterial strains that reached 100% mortality after 120 min of air exposure were isolated. Ten of these strains were tested for their atmospheric O2 sensitivity as a function of air exposure time; all tested microorganisms showed a similar mortality trend on exposure to air. In fact, 50% of cells survive, on the average, after 4–5 min of atmospheric O2; this percentage decreases to 3–5% after only 20 min, and after 40 min only one cell in a thousand survives; all strains reached 100% mortality in a time range of 100–120 min. The strains examined were identified as belonging to the generaEubacterium, Peptostreptococcus, andCoprococcus
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
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