1,721,024 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
Prediction of perceived astringency induced by phenolic compounds II: Criteria for panel selection and preliminary application on wine samples
No full textIn the following work, subject saliva characteristics affecting panel astringency evaluation in phenolic mixtures were studied. Sixty subjects were selected on the basis of their salivary flow, haze developing capacity and protein concentration. Subjects rated the perceived astringency of tannic acid (TA), commercial procyanidin (PA) and grape seed extract (GSE) solutions with concentration values ranging from 0.42 to 1.4 g/L. Astringency intensity perception proved to be inversely related to saliva flow rate and haze developing capacity. No significant correlations were found between saliva protein concentration and intensity of astringency perception. A panel selected on the basis of subject similarity for flow rate and haze developing capacity rated the astringency intensity of set sample training solutions of TA, PA and GSE with concentrations ranging from 0.39 to 4.48 g/L. The reactivity of the same astringent solutions with mucin was measured in an in vitro assay and expressed in terms of Nephelometric Turbidity Units (NTU). Three predictive models described by a linear regression of astringency intensity vs. NTU were found. The possibility of a practical application of the proposed assay for optimization of wine production was evaluated on 18 experimental wines. A linear correlation was found between the intensity astringency ratings of wine samples and the in vitro assay response. © 2005 Elsevier Ltd. All rights reserved
Time-based expressivity of time Petri nets for system specification
No full textAbstractVarious models of time Petri Nets have been successfully used to adequately specify time-critical systems. For such systems correctness depends not only on the actions that are performed, but also on the times when they are performed. Therefore, the semantics must take explicitly into account the timings of actions, and also concepts of time-based expressivity are needed to compare the expressive power of the various models. In the paper we introduce a general framework that includes many Petri net models, present in the literature, which differ from one another with respect to timing location, timing strength and time domain. Then we introduce an operational semantics that takes into account both sequentialization and timing of actions. When abstracting time away we reobtain previously reported results, which are useful when one is interested in modelling systems that are not time-critical. On the other hand, when abstracting the sequentialization of actions away we define a new kind of expressivity in terms of which we compare the various models we have considered
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
Rischio cardiovascolare nella popolazione aquilana. Studio longitudinale
No full textINTRODUZIONE
Ancora oggi le malattie cardiovascolari (CV) rappresentano la principale causa di mortalità e disabilità nei paesi maggiormente sviluppati, a causa dell’aumentata esposizione a fattori di rischio, legati all’alimentazione non salutare, all’abitudine al fumo e all’inattività fisica. A questi si aggiungono fattori non modificabili, quali l’età, il sesso e la familiarità per CV. Attraverso la diagnosi di Sindrome Metabolica (SM), che rappresenta uno degli strumenti per individuare i soggetti a maggior rischio, è stato condotto uno studio volto a valutare la situazione del rischio cardiovascolare (RCV) nella popolazione aquilana. METODI
Lo studio ha interessato i pazienti del territorio aquilano di età 40-69 anni afferenti presso gli ambulatori dei Medici di Medicina Generale. La prevalenza di SM, la cui diagnosi è stata effettuata secondo i criteri del panel ATPIII, è stata valutata e confrontata, attraverso il χ2 test per il trend, nei periodi 2006-2008, 2009 (immediato post-sisma) e 2016. Attraverso un modello di regressione logistica multivariato è stato valutato l’effetto sulla diagnosi di SM, posta come variabile dipendente, di ciascuna delle variabili esplicative (età, sesso, BMI, colesterolo totale, anno oggetto di studio) aggiustato per gli effetti delle altre variabili indipendenti.
RISULTATI
Su un totale di 1519 soggetti arruolati nello studio, la prevalenza di SM è risultata essere pari al 30,22%, con un marcato aumento nell’immediato post-sisma (57,07%) rispetto al 2006-2008 (27,37%) e un successivo rientro del picco nel 2016 (25,10%) (χ2 test per il trend: p<0,001). La regressione logistica ha messo in luce che il 2009 si associava ad una maggiore probabilità di presentare diagnosi di SM (OR 4,78, IC 95% 3,10–7,37; p<0,001) rispetto al periodo 2006-2008.
CONCLUSIONI
Sulla base dei risultati della nostra indagine è ampiamente plausibile l’ipotesi che la variazione del RCV nella popolazione aquilana sia strettamente legato all’evento sisma
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