1,721,129 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
Malattia del sonno in Bosnia-Erzegovina: aspetti clinici e anatomopatologici.
Full text linkL’alfavirus dei salmonidi è responsabile della malattia del pancreas nel salmone atlantico (Pancreatic Disease-PD) e della malattia del sonno nella trota iridea (Sleeping Diseases-SD), le quali sono facilmente trasmissibili e possono causare notevoli perdite. L’eziologia virale di queste malattie è stata accertata più vent’anni fa (nel 1976 per la PD e nel 1994 per la SD) e il virus è stato il primo Alphavirus (famiglia Togaviridae) a essere isolato in trote malate. Gli stati dell’Europa continentale sono interessati soltanto dalla SD, dove è stata sicuramente segnalata in Svizzera, Francia, Germania, Spagna, Croazia e Italia. Tuttavia, la SD non rappresenta un rischio sanitario preminente per l’allevamento della trota iridea, poiché, in Italia come negli altri stati europei interessati, la mortalità è in genere trascurabile, sebbene, in alcuni casi, possa superare il 20% (Boucher et al., 1994; Graham et al., 2003). In quest’ottica, si ritiene interessante descrivere alcuni aspetti clinici e anatomopatologici di malattia del sonno verificatasi negli ultimi tre anni in un allevamento in Bosnia-Erzegovina. L’allevamento è alimentato da acqua di fiume, con temperatura di 8-9°C costante tutto l’anno, nel quale, negli ultimi anni, sono state introdotte diverse specie ittiche (trota iridea, trota fario e temolo) per la pesca sportiva. Nel 2015 si è verificato il primo episodio di SD, caratterizzato da un quadro clinico e un andamento della malattia in linea con quanto descritto in letteratura, anche in termini di classe di età maggiormente sensibile (2-15gr), mortalità e lesioni anatomopatologiche. Nei due anni successivi (soprattutto nel 2017) la situazione si è notevolmente aggravata, con tasso di mortalità medio del 60% e picchi fino all’80%, quadri clinici non completamente sovrapponibili a quelli descritti in letteratura (l’atassia motoria si manifesta come incoordinazione natatoria piuttosto che l’atteggiamento dormiente e manca la tipica colorazione bluastra) e severe lesioni anatomopatologiche. Il quadro istolesivo è, infatti, caratterizzato da grave e diffusa necrosi del pancreas esocrino (con conseguente atrofia pancreatica e, quindi, inibizione della funzione digestiva), del tessuto linfoide (milza e rene anteriore) e dei cardiomiociti (atrio e ventricolo) che, tipicamente, appaiono eosinofili, con il citoplasma coartato e il nucleo picnotico. Negli episodi più recenti, diffuse necrosi focali epatiche completano il quadro, mentre le lesioni muscolari sono poco apprezzabili.
Questi episodi di SD, oltre a rappresentare la prima descrizione della malattia in Bosnia-Erzegovina, illustrano un quadro di malattia più grave rispetto ad altri contesti geografici per l’impatto sulla produzione zootecnica dell’allevamento, e ponendo dei quesiti epidemiologici sulla gestione sanitaria dell’impianto
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
Comparative analysis of an mcr-4 Salmonella enterica subsp. enterica monophasic variant of human and animal origin
Full text linkObjectives In this study we compared the recently described mcr-4-positive Salmonella enterica monophasic variant, isolated in 2016 in two Italian patients affected by gastroenteritis, with the first mcr-4-positive Salmonella isolate identified in 2013 in a pig at slaughter in Italy. Methods WGS of the two Salmonella isolates of human origin was performed using a MiSeq instrument (Illumina). The phylogenetic analysis was performed by SNP analysis, comparing genomes of the mcr-4-positive isolates of swine and human origin with 82 Salmonella genomes downloaded from the EnteroBase Salmonella database. Complete sequences of plasmids carrying mcr-4.2 were obtained and compared. Transformation experiments were performed to transfer the mcr-4 plasmids into a colistin-susceptible Escherichia coli recipient strain. Results Comparative genomics demonstrated that the Salmonella of swine origin did not cluster with the isolates of human origin. The mcr-4.2 gene variant identified in the Salmonella of human origin was located on a ColE-like plasmid. This plasmid showed different replication and mobilization genes with respect to those previously described in the ColE plasmid carrying the mcr-4.1 variant, identified in Salmonella of swine origin. Conclusions The divergence in genomes, plasmids and gene variants demonstrated that there was not a unique mcr-4-positive, monophasic Salmonella lineage circulating in animals and causing gastroenteritis in humans in Italy. There was no horizontal transfer of the same plasmid among Salmonella strains of animal and human origin, but the mcr-4 gene and a fragment of the plasmid identified in the animal strain were mobilized by an IS1294 into a different ColE plasmid. © The Author(s) 2018. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved
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
Land use/cover change in the Tam Giang - Cau Hai Lagoon (Central Vietnam) by means of SPOT 5, Aster and Landsat images
Full text linkAbstract Number: EGG01617
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