1,720,960 research outputs found
Interazione fra cardiologo e cardiochirurgo nella pratica clinica della chirurgia ricostruttiva mitralica
Full text linkPREMESSE E SCOPO DELLO STUDIO. Numerosi studi clinici hanno dimostrato i vantaggi della ricostruzione della valvola mitrale (RVM) rispetto alla sostituzione della valvola (SVM), ma sia in Europa che negli Stati Uniti il tasso di ricostruzione si mantiene intorno al 50 %.
L'obiettivo di questo studio è stato quello di valutare l’impatto dell’interazione fra il cardiologo e il cardiochirurgo, derivante dalla formazione di un “Team mitralico”, sulla incidenza della RVM con l’obiettivo finale rappresentato dall’aumento delle procedure di ricostruzione.
METODOLOGIA. Abbiamo analizzato i dati di 323 pazienti sottoposti consecutivamente a chirurgia della valvola mitrale, isolata o associata ad altre procedure, nel periodo di sei anni. A partire da gennaio 2009 è stato costituito un “Team mitralico” formato da un cardiologo (F. T.), sempre la stessa, e da un chirurgo nella persona del responsabile della UOC Cardiochirurgia. I risultati dei 176 pazienti operati nel triennio 2006-2008 precedente alla costituzione del team (Gruppo I) sono stati messi a confronto con i 147 pazienti sottoposti ad intervento nel triennio 2009-2011 (Gruppo II).
RISULTATI. La percentuale di riparazione in tutti i 323 pazienti sottoposti a chirurgia della mitrale da un gruppo di 6 chirurghi con esperienza diversa è stata del 39 % (69 di 176) nel gruppo I e del 46 % (67 di 147) nel gruppo II, un miglioramento modesto e non significativo. La percentuale di riparazione è aumentata significativamente nei pazienti trattati dal Team mitralico passando dal 44% (47 di 107) del primo periodo al 66% (38 di 58; p< 0,001) del secondo periodo. Nel gruppo I la percentuale di riparazione del Team mitralico rispetto agli altri operatori non ha evidenziato differenze significative (media 44% contro il 33% rispettivamente), mentre è stata significativamente più elevata nel gruppo II (media 66 % contro il 33% ; p< 0,002). Nel gruppo II dei pazienti trattati dal Team mitralico le percentuali dei tentativi di ricostruzione e dei successi di ricostruzione sono state significativamente più alte rispetto al gruppo I (p< a 0,002 e 0,05 rispettivamente). Nei pazienti del gruppo II del Team mitralico il tasso di ricostruzione è stato significativamente più elevato in tutti i tipi di disfunzione valvolare. La nuova metodica di ecocardiografia tridimensionale facilita l’analisi segmentaria della valvola in quanto fornisce immagini simili a quelle osservate dal chirurgo al tavolo operatorio, ma deve essere ancora utilizzata come indagine complementare alla ecocardiografia 2D.
CONCLUSIONI. L’applicazione delle immagini ecocardiografiche 2D e 3D nella chirurgia della valvola mitrale richiede un rapporto di collaborazione e una interazione ottimale fra cardiologo e cardiochirurgo. Questa interazione può determinare, come si è verificato nel nostro studio, un aumento significativo del tasso di ricostruzione della valvola
Credit Ratings, CEO Entrenchment, and Turnover: The Information Content of Credit Ratings Beyond Firm Performance
No full textWe study the relationship between credit rating changes and CEO turnover beyond firm performance. Within an adverse selection framework that explicitly incorporates rating change related turnover, our model predicts that a downgrade triggers turnover, even following a good firm performance. Our empirical results support this prediction. We show that credit rating downgrades explain forced turnover risk, both internal and external, after accounting for the firm prior stock market and accounting performance. Further, we find that the relationship between credit rating changes and management turnover is stronger when the degree of managerial entrenchment is low. Our results are robust to endogeneity concerns and shed light on the idea that the information content of credit ratings goes beyond firms’ performance
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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