1,721,015 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
The detection of foodborne pathogens using bacteriophage-based AK assay
No full textA sensitive and rapid phage-mediated AK assay was developed for the detection of 'E. coli' G2-2 and 'S. enteritidis '. In this assay, a bacteriophage is employed as a lytic agent for its target bacteria. The number of bacterial cells presence can be detected by measuring the degree of lysis and hence the release of intracellular adenylate kinase (AK). AK is assayed in the presence of excess ADP by measuring the formation of ATP by bioluminescence using the luciferase/luciferin reaction. In this study, the commercial ADP was purified for the assay using HPLC technique. For 'E. coli' G2-2 and 'S. enteritidis', the detection limits in pure culture were estimated to be approximately 1.2 * 103 CFU/ml and 1.5 * 103 CFU/ml, respectively. The effect of competitive flora on the ability of phages to infect host cells was also evaluated. The detection limit of 'E. coli' G2-2 in mixed culture was around 1.4 * 103 CFU/ml; for ' S. enteritidis', it was approximately 1.7 * 103 CFU/ml
Enhancement of macrophage cytokine production by cell-free fractions of fermented milk
No full textThe objective of this research was to assess the ability of milk fermented by probiotic bacteria to enhance immune responses as reflected in macrophage cytokine production. An 'in vitro' assay was established with a macrophage tissue culture cell line and an ELISA. Milk fermented by four probiotic strains was found to induce interleukin-production in the macrophages, as did cell-free supernatant of each fermented milk when lipopolysaccharide was incubated concurrently. Cell-free supernatants were fractionated by ultrafiltration and reversed phase chromatography, in which immunological activity was found to reside within a small region of peaks in the chromatogram. Further chemical analyses may help to identify the bioactive substances. Results suggested that substances released during fermentation, independent of the presence of live bacterial cells, could enhance immune responses. Priming the immune system may be an important health-promoting property of probiotic fermented dairy products consumed as functional foods
The use of bacteriophage in detecting foodborne bacterial pathogens
No full textSalmonella is the second leading cause of foodborne illness in most developed countries causing diarrhea, cramps, vomiting and often fever. Poultry, eggs and milk are frequently implicated as vehicles of infection. Simple, rapid, and specific methods are required for the detection of Salmonella in foods. A bacteriophage assay combining the use of immunomagnetic separation (IMS) with fluorescence or absorbance measurements, was developed for the detection of Salmonella Enteritidis. The sensitivity of the assay in pure suspensions, skimmed milk powder, ground beef and liquid whole egg was determined. The IMS-bacteriophage assay was able to detect 3 CFU/g or ml present initially in each of these food samples. The assay was generally specific for serogroup D Salmonella, with Salmonella Typhimurium also testing positive. The IMS-bacteriophage assay was adapted to the detection of E. coli O157:H7. The assay was able to detect 2.5 CFU/g E. coli O157:H7 present initially in ground beef
Design and operation of a Canadian University Containment Level 3 Facility
No full textThe Canadian Research Institute for Food Safety (CRIFS) Containment Level 3 (CL3) Facility is the first permanent CL3 laboratory to be built at the University of Guelph. This facility is to provide CRIFS researchers and campus associates the means to work with indigenous Risk Group 3 (RG3) infectious materials within a safe and highly controlled environment. In Canada, the construction, commissioning and operation of containment facilities are mandated and monitored by two federal regulating agencies, the Public Health Agency of Canada and the Canadian Food Inspection Agency. Success in managing a Containment Level 3 Facility, especially one where the intended function has not been restricted to a particular type or group of Risk Group 3 agents, demands that extraordinary provisions be in place to ensure compliance with the current standards and regulations. Therefore, it has been necessary to develop effective criteria focusing on policy, standards, procedures and training programs not only for potential users and support staff but also for the University of Guelph Biosafety Program to clearly demonstrate the responsibilities of CRIFS, Physical Resources - Operations and Maintenance, and the University Administration (Biosafety Officer, EH&S, Campus Security Services)
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