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Norovirus Presence in three commercially most popular species of mollusks available in the Emilia Romagna region, Italy
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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
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
Ricerca di Norovirus in molluschi bivalvi immessi in commercio in Emilia Romagna, Italia
No full textI Norovirus (NoV) sono piccoli virus a RNA della famiglia Caliciviridae responsabili di gastroenteriti nell’uomo. L’infezione può trasmettersi per via alimentare tramite il consumo di molluschi bivalvi. Questi animali, infatti, in quanto filtratori, possono accumulare diversi contaminanti, compresi i virus enterici umani come i NoV. Sulla base dell’analisi genetica, i NoV possono essere suddivisi in 5 genogruppi (GI-GV), di questi, nell’uomo sono stati evidenziati prevalentemente i genogruppi GI e GII. Recentemente è stata evidenziata anche la presenza di NoV GIV.
Lo scopo di questo lavoro è quello di ricercare la presenza di NoV in molluschi bivalvi immessi in commercio in Emilia Romagna prelevandoli direttamente dai banchi di vendita, al fine di valutare il possibile rischio per i consumatori finali.
Sono stati raccolti e analizzati 95 lotti di molluschi di cui 41 di vongola filippina (Venerupis philippinarum), 29 di mitilo (Mytilus galloprovincialis), 20 di ostrica concava (Crassostrea gigas), 2 di fasolare (Callista chione), 2 di vongola comune (chamelea gallina) e 1 di ostrica comune (Ostrea edulis). Pool di epatopancreas sono stati trattati con la Proteinasi K al fine di digerire il tessuto analizzato e liberare in tal modo la componente virale, quindi l’RNA è stato estratto con un kit commerciale. La ricerca del virus è stata condotta con tecnica RT-PCR one-step utilizzando i primers JV12-JV13, specifici per la regione dell’RNA-polimerasi, che amplificano un frammento di 326 bp di NoV sia GI che GII. Successivamente, è stata condotta una caratterizzazione utilizzando due seminested-PCR specifiche per i due genogruppi. Alcuni prodotti di PCR sono stati sottoposti a sequenziamento ed analisi filogenetica.
NoV è stato evidenziato in campioni di vongole filippine, mitili e ostriche concave per un totale di 14 lotti (14,7%). I campioni più contaminati sono risultati quelli di vongola filippina (22%) rispetto a mitili e ostrica concava (10%). Entrambi i Genogruppi erano presenti in vongola filippina e mitilo, mentre in ostrica concava è stato evidenziato solo NoV GI. Quattro lotti sono risultati contaminati sia da GI che da GII. Il sequenziamento e l’analisi filogenetica hanno evidenziato la presenza dei genotipi GII.4, GII.g e GII.b nell’ambito del genogruppo II.
L’evidenziazione di una alta diffusione di NoV in molluschi bivalvi immessi in commercio sottolinea l’inadeguatezza dei sistemi di controllo attualmente in atto. Ulteriori screening sui molluschi bivalvi e l’implementazione dei sistemi di controllo sono da perseguire, al fine di prevenire le infezioni umane su base alimentare
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
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