1,720,959 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Olfactory Carcinoma Invading Orbital Apex Treated by Combined Transnasal-Transorbital Resection with Extended Orbital Clearance and Anterior Cavernosectomy: 2-Dimensional Operative Video
No full textVariations on the Author
Get PDF“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
Get PDFWe 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
Adenocarcinoma nasosinusale di tipo intestinale: analisi multicentrica retrospettiva di sopravvivenza
No full textL'adenocarcinoma nasosinusale di tipo intestinale (ITAC) è il tumore naso sinusale più comune nei paesi europei. La letteratura scientifica riconosce diversi fattori di rischio e caratteristiche intrinseche della neoplasia, come i differenti sottotipi, tra i principali fattori prognostici. È stata condotta un'analisi retrospettiva dei fattori di rischio associati alla sopravvivenza globale (OS), alla sopravvivenza specifica per il cancro (CSS) e alla sopravvivenza libera da malattia (DFS) in pazienti affetti da ITAC nasosinusale, trattati con un protocollo chirurgico incentrato sulla chirurgia endoscopica in 6 centri europei. È stato condotto uno studio prognostico con analisi multivariata. I risultati di questo lavoro ci permettono di affermare che considerare l'ITAC come un'entità unica non è più consigliabile, poiché i diversi sottotipi presentano una prognosi significativamente diversa. Fino a quando non saranno disponibili nuovi biomarcatori standardizzati, la gestione dell'ITAC deve essere personalizzata in base a diversi fattori, con la sottotipizzazione basata sull'istopatologia che assume un'importanza fondamentale
Homological Instability in Pre-Braided Homogeneous Categories
No full textWe do not know many examples of sequences of groups fitting the categorical framework of pre-braided homogeneous categories, but for which we don't have connectivity, and homological stability fails. Peter Patzt constructed such an example with symmetric groups, and the goal of this thesis is to present other examples of the same flavour. Chapter one provides all the algebraic tools needed later, as well as the necessary theory about homology of groups. Chapter two introduces homological stability in the categorical framework of pre-braided locally homogeneous categories. For pairs of objects in such categories we construct the associated sequence of spaces, and formulate the connectivity axiom. We give also a proof of an homological stability theorem (only for integral homology), which states that the connectivity implies stability for the sequence of automorphism groups associated to the pair. The last chapter presents a nice criteria for checking 0-connectivity, and examples of unstable sequences of groups fitting into pre-braided homogeneous categories. We present examples in symmetric groups, general linear groups and projective general linear groups
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
L'uso della elettrochemioterapia nel trattamento dei tumori di testa e collo
No full textI tumori maligni della testa e del collo rappresentano in Italia circa il 5% di tutti i tumori maligni e sono al 5° posto come frequenza, con circa 12000 nuove diagnosi ogni anno. Approssimativamente nei due terzi dei pazienti con neoplasie maligne di testa e collo, la malattia viene diagnosticata in uno stadio avanzato e sono trattati tramite l’integrazione di chirurgia e radioterapia o chemioterapia e radioterapia concomitante. Nonostante l’adeguatezza dei trattamenti, le recidive locali si riscontrano in un 10-30% dei casi e il trattamento di queste rappresenta un problema tuttora aperto, soprattutto in quei pazienti già sottoposti a procedure chirurgiche particolarmente demolitive o quando già trattati con radioterapia. Per tali pazienti, sfortunatamente ad oggi, non esistono efficaci alternative farmacologiche o radioterapiche e la chirurgia di salvataggio, se effettuabile, nella maggior parte dei casi determina una importante perdita di funzione delle aree anatomiche coinvolte. Alla luce di tali problematiche la ricerca si è concentrata nello sviluppo di nuove terapie per il trattamento dei tumori della testa e del collo, di cui l’elettrochemioterapia (ECT) ne rappresenta un importante esempio. L’elettrochemioterapia sfrutta l’azione sinergica del fenomeno fisico dell’elettroporazione delle membrane cellulari e della somministrazione di farmaci antineoplastici, come la bleomicina, con il risultato di potenziare notevolmente l’effetto citotossico. Attualmente l’ECT rappresenta una possibilità di trattamento con intento palliativo per le recidive locali e le metastasi del distretto cervico-facciale. Il seguente lavoro si pone l’obbiettivo di presentare l’esperienza maturata nel trattamento ECT di questa complessa tipologia di patologie, analizzandone risultati, criticità e prospettive future
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