1,721,008 research outputs found
Optimizing femoral tunnel and interference screw alignment in ACL reconstruction: A mathematical model
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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
Femoral Interference Screw Position In Transtibial Acl Reconstruction: How To Optimize Alignment With A Mathematical Model. A Cadaveric Study
No full textFemoral interference screw divergence is a potential pitfall
associated with ACL reconstruction through transtibial tunnel technique, as angles greater than 15 jeopardize graft fixation. Our mathematical model theorizes the proper degrees of knee flexion during femoral screw insertion
and the correct screwdriver position to obtain a minimal divergence of the screw in the femoral tunnel. The cadaveric study confirms our method
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
A novel technique for testing osteointegration in load-bearing conditions
No full textWhen a new material for the realization of an implantable device in the bone is being studied, in addition to its chemical-physical-mechanical haracterization, tests regarding osteointegration are performed. Usually, researchers evaluate the ability of biomaterials to bind to the bone under load-bearing conditions, through animal experiments in the phase of a preclinical study, provided the respective authorization by the ethics committee. In more detail, plugs made of the material under investigation are prepared and implanted into a weight-bearing portion of the skeleton of animals (typically into the knee joint of goats, pigs, rabbits or dogs); after a pre-set time, the animal is sacrificed, the bone element is extracted, it is tested mechanically – generally by means of a pull-out test – and finally it is examined histologically. Mechanical tests often require demanding specimen preparation, which could bias results. In the scope of a research regarding the interface behaviour of a ceramic plug (two different ceramic plugs) compared to a titanium one, the authors have suggested a novel testing technique which allows to perform ‘push-in’ tests, instead of the more common pull-out tests. This methodology has been followed here to compare titanium versus ceramic plugs at different times from implant (0, 3 months, 1 year) into goat knees. As a result, the study reports the shear resistance of bone–plug interfaces. The statistical analysis of the data allowed us to establish that titanium plugs systematically exhibit a higher resistance (p<0.10); this resistance undergoes a significant increment as time passes (p<0.07) due to progressive osteointegration
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
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