1,720,995 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
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
Antimicrobial resistance of Shigella sonnei isolates carrying class 2 integron in Northern Italy
No full textBackground: In the last decades, several reports on Shigella sonnei epidemiology from different countries have associated the epidemic circulation of this organism to a well defined strain, characterized by some proprierties, like a resistant phenotype streptomycin, sulfonamide, trimethoprim and tetracycline, a distinct XBaI pulsotype and the presence of class 2 integron. The objective of this study was to evaluate the genetic heterogeneity of molecular profiles, drug susceptibility pattern, and carriage of class 2 integron of S. sonnei collected in northern Italy. Materials: A total of twenty-five clinical isolates of S. sonnei identified in Lombardy region during the years 2009-2012 were studied. All isolates were subtyped by Pulsed-Field Gel Electropheresis (PFGE) according to the PulseNet protocol with XBaI enzyme to detect clusters and support epidemiological investigations. Furthermore, antimicrobial susceptibility testing was performed by the disk diffusion method as recommended by the National Committee of Clinical Laboratory Standards. Finally, polymerase chain reaction (PCR) was performed with the specific primer pair -hep74 and hep51- to detect the class 2 integron. Results: Eight XbaI pulsotypes with homology over 80% were recognized among the 25 clinical isolates. Twenty-three isolates were grouped in six clusters, while the remaining two isolates showed unique pulsotypes, one of which was reported in 2001 (Mammina et al., J. Clin. Microbiol., 2005). Two different class 2 integron structures were identified. Nine (36%) isolates contained a 2.22-kbp gene cassette (dhfr1, sat, and aad) were phenotypically resistant to trimethoprim and streptomycin, also ten (40%) isolate produced a smaller cassette structure of 1.37-kbp encoding only two genes within the cassette (dhfr1 and sat) were resistant to streptomycin. Finally, no class 2 integrons were detected in the remaining six (24%) isolates. Conclusion: The finding of our studies revealed the persistence of a pulsotype isolated in Lombardy in 2001. Moreover, ten S. sonnei isolates containing defective class 2 integron (1.37-kbp) were resistant to streptomycin. It is possible that in this case the streptomycin resistance may be due to aad gene present on a plasmid
Clonal circulation of Salmonella enterica serotype Heidelberg in Italy?
No full textPhenotypic and genetic characteristics of 21 strains of Salmonella serotype Heidelberg isolated in the years 1999-2003 from different sources in Italy were studied. Susceptibility patterns, plasmid analysis, and PFGE were used as epidemiological markers. Although non-homogeneous drug resistance patterns and plasmid profiles had been detected, PFGE patterns suggest the hypothesis of a nationwide clonal spread of this serotype associated with poultry
Genetic heterogeneity of Listeria monocytogenes in Northern Italy
No full textBackgroud: Invasive listeriosis is a rare foodborne disease that can cause septicaemia, meningoencephalitis and eventually death in vulnerable population. The ethiologic agent, Listeria monocytogenes, is genetically heterogeneous, therefore discriminating strains is of major importance for prompt outbreak detection and improvement of surveillance. The aim of this study was detecting emerging strains and monitoring their frequency in Lombardy region.
Methods: In Lombardy, the mandatory notification system has been integrated since 2005 with a laboratory-based surveillance network based on voluntary referral of clinical strains to the Regional Reference Laboratory. All human L. monocytogenes strains collected (2005-2013), were serotyped and subtyped by Multi-locus Sequence Typing (MLST). Sequence Types (STs) were assigned in accordance to the Listeria MLST database (Pasteur Institute, France).
Results: Among the 245 collected strains 49 STs were identified, 36 of them had been previously reported in the same area. The predominant serotypes were 1/2a (59.6%), 4b (26.1%) and 1/2b (10.6%), while the 6 most common STs were ST38 (16.7%), ST1 (11.8%), ST8 (9.4%), ST155 (6.5%), ST2 (5.7%) and ST3 (4.9%), accounting for 55% of the strains. The frequency of ST38 and ST155 led us to hypothesize the occurrence of two outbreaks undetected by local health authorities, during the period 2009-2011. In particular, the identification of ST155 strains began in 2008 (n=1), peaked in 2011 (n=10) and continued in 2013 (n=5) with 3 pregnancy-related cases closely linked in space and time. For these 3 cases an epidemiological investigations was implemented but failed to identify the source. Only in one case (ST8), it has been possible to characterize the implicated food (brique cheese). Finally, ST1, ST2 and ST3 showed a trend of persistence with a wide distribution across time and space.
Conclusions: This study reveals the main STs present in the regional area and enhances our understanding of the genetic diversity of circulating L. monocytogenes strains. The monitoring of these STs will provide important information useful for the prevention of listeriosis and for supporting the epidemiological investigations, which specifically for listeriosis are often arduous
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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