1,721,217 research outputs found
Vascular anatomy of canine hepatic venous system : a basis for liver surgery
No full textDetailed knowledge of the vascular anatomy is important for improving surgical approaches to the liver. Twelve canine livers were skeletonized to describe the anatomy of their portal and hepatic veins in details. Our data suggest that the liver can be divided into two sections, three divisions, seven lobes and two to four sub-lobes. This differs from the classic division into four lobes, four sub-lobes and two processes. The right section was perfused by the right portal branch and drained by independent hepatic veins, while most of the left section, perfused by the left portal branch, was drained by the main hepatic vein deriving from the middle and the left hepatic vein confluence. Part of the right medial lobe, and in some cases the papillary process of the caudate lobe, drained directly into the caudal vena cava. A proper right hepatic vein draining blood from more than one lobe was never observed. Portal connections between the quadrate and the left medial lobe were frequently recorded. Two sub-lobes with different portal blood supply and venous drainage could be identified in the right lateral (33.3% of cases) and the left lateral (100% of cases) lobes. From our results, the classic nomenclature of the liver lobes does not reflect their vascularization. Based on similarities between canine lobes and human segments, a new nomenclature is possible and may be less confounding in surgical settings
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
On the Metrological Evaluation of the Software Component of Intelligent Measuring Systems
No full textThe evaluation of the metrological performance of the software in intelligent measuring systems (IMS) is discussed. The performance of an IMS can be evaluated according to two different goals and strategies, typically relevant at different stages in the life cycle of an IMS; the evaluation of the general performance of an IMS and the evaluation of an IMS performance for a specific measurement task.1999-0
The Coherent Matching Distance in 2D Persistent Homology
Full text linkComparison between multidimensional persistent Betti numbers is often based on the multidimensional matching distance. While this metric is rather simple to define and compute by considering a suitable family of filtering functions associated with lines having a positive slope, it has two main drawbacks. First, it forgets the natural link between the homological properties of filtrations associated with lines that are close to each other. As a consequence, part of the interesting homological information is lost. Second, its intrinsically discontinuous definition makes it difficult to study its properties. In this paper we introduce a new matching distance for 2D persistent Betti numbers, called coherent matching distance and based on matchings that change coherently with the filtrations we take into account. Its definition is not trivial, as it must face the presence of monodromy in multidimensional persistence, i.e. the
fact that different paths in the space parameterizing the above filtrations can induce different matchings between the associated persistent diagrams. In our paper we prove that the coherent 2D matching distance is well-defined and stable
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