1,720,959 research outputs found
First passage time problems and related computational methods
No full textMotivated by the interest of first passage time problems in neurobiology and in a variety of applied fields, we study the solution of first passage time equations for the Wiener and the Ornstein Uhlenbeck process both in the general case of time dependent threshold functions. Some computational results obtained by two different numerical methods are reported and briefly discussed
Chievitz' juxtaparotid organ, free from cancer
No full textAbstractin English, Italian INTRODUZIONE: Fino alla metà del XX secolo, l’organo di Chievitz è stato considerato un organo embrionale, che scompare con la crescita. Zenker, invece, nel 1953, ha dimostrato l’esistenza di questo organo anche nella vita adulta. STUDIO: In questo articolo descriviamo l’embriologia, l’anatomia macroscopica e microscopica, l’ultrastruttura, il significato funzionale e la patologia dell’organo iuxtaparotideo di Chievitz’(CJO). Il CJO non è un organo macroscopicamente evidente, ma ha l’aspetto simile ad un nervo. Il CJO prende collegamenti con il muscolo buccinatore, a livello del condotto parotideo e con il muscolo pterigoideo mediale. Il parenchima cellulare è avvolto da tessuto connettivo, che è diviso in tre strati: lo strato interno - “strato fibrosum internum” -, composto da microfibrille di collagene; lo strato intermedio - “stratum nervosum” - contenente un nucleo interno lamellare e strutture nervose di Ruffini; lo strato esterno - “stratum fibrosum externum”, che è una capsula di collagene. Le cellule parenchimali contengono enzimi, quali la fosfatasi alcalina e l’anidrasi carbonica, con una ricca attività enzimatica, simile a quella delle cellule duttali delle ghiandole salivari. Il CJO presenta, inoltre, un’importante funzione meccanosensore di questa regione. Quando viene eseguita una resezione chirurgica per un carcinoma orale, il CJO può essere presente nel pezzo operatorio. Il CJO può essere erroneamente diagnosticato come invasione perineurale da carcinoma. CONCLUSIONE: Sulla base della revisione della Letteratura, tuttavia, si può definire che l’organo di Chievitz è l’unico organo in cui il cancro non si verificaAbstractin English, Italian INTRODUCTION: Up to the half of twentieth century, Chievitz organ was considered an embryonal organ, disappearing with growth. But Zenker, in 1953, demonstrated the existence of this organ in adult life, too4. REVIEW: In this article we review the embryology, the macroscopic and microscopic anatomy, the ultrastructure, the functional significance and the pathology of the Chievitz'Juxtaparotid Organ (CJO). The CJO is not a macroscopic apparent organ, but it looks like a nerve. The CJO takes connections with buccinator muscle, at the level of the parotid duct, and the medial pterygoid muscle. The cell parenchyma is enveloped by the connective tissue, that is divided into three layers15, 16: the inner layer -"stratum fibrosum internum"-, composed of collagenous and elastic microfibrils; the middle layer - "stratum nervosum" - containing a lamellar inner core and Ruffini SNF5; the external layer - "stratum fibrosum externum", that is a collagen capsule. The parenchymal cells show a rich enzyme activity. The parenchymal cells may play the same role as glomus cells of the 1st type and Merkel cells20, 21. When a surgical resection is performed for an oral carcinoma, the CJO may be present in the specimen25. The CJO may be wrongly diagnosed as perineural invasion by carcinoma26, 27, 28. CONCLUSION: We report that Chievitz' organ is the only organ in which the cancer does not occur
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
Variations 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
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
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
- …
