1,721,079 research outputs found
Finite element models of total shoulder replacement: application of boundary conditions
No full textThe widespread use of FEA within orthopaedics is often prohibited by the limits of available computational power, with simplifications to the model often necessary in order to permit solution. An example of this includes the use of osseous models that exclude muscular loading, and may consist of only a partial or truncated region of the anatomy. However, is it possible to make such simplifications without affecting the predictive quality of the model? This issue has been considered using the specific example of the total shoulder reconstruction, where the effects of including the entire osseous region and/or the muscle loadings, has been evaluated. The effect of including the muscle loadings and the entire osseous structure was seen to increase with distance from the articular surface of the glenoid prosthesis. Stresses in the cement mantle were reduced in the absence of either the entire scapula bone or the muscle loading. The study suggests that the use of a fully defined scapula (hard- and soft-tissue) is particularly important when investigating fixation, whilst less comprehensive models should be appropriate for studies of the prosthesis exclusively
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
The effects of glenoid component alignment variations on cement mantle stresses in total shoulder arthroplasty
No full textLoosening of the glenoid component has been cited as the most frequent cause of patient dissatisfaction with total shoulder arthroplasty, and it has been demonstrated in clinical studies that misalignment of the prostheses can be a causative factor. Finite element analyses of five different glenoid component alignments (central, anteverted, retroverted, inferiorly inclined, and superiorly inclined) were conducted in order to predict changes in the survivability of the cement mantle surrounding the glenoid component. The potential for mechanical failure of the mantle in the centrally aligned implant, during unloaded abduction, was seen to be lower than for any other alignment. Normal bone outperformed simulated rheumatoid models in all cases. Retroversion was worse than anteversion, and superoinferior misalignment was worse than anteroposterior. The quality of the supporting bone stock was found to be particularly significant to cement survivability, more so than the occurrence of eccentric loading of the joint. Shear forces acting on the glenoid component were found to be more detrimental than axial forces, resulting in a greater likelihood of failure toward the extremes of motion. The study suggests that significant efforts should be made to align the glenoid component correctly and also to ensure suitably consistent support of the prosthesis within the bone
Quantifying the pivot shift test: A systematic review
No full textThis study aims to identify and summarize the evidence on the biomechanical parameters and the corresponding technologies which have been used to quantify the pivot shift test during the clinical and functional assessment of anterior cruciate ligament (ACL) injury and surgical reconstruction.
METHODS:
Search strategy Internet search of indexed scientific articles on the PubMed database, Web of Science and references on published manuscripts. No year restriction was used. Selection criteria Articles included were written only in English and related to search terms: "pivot shift" AND (OR "ACL"). The reviewers independently selected only those studies that included at least one quantitative parameter for the analysis of the pivot shift test, including both in vitro and in vivo analyses performed on human joint. Those studies that analysed only clinical grading were excluded from the analysis. Analysis After evaluating the methodological quality of the articles, the parameters found were summarized.
RESULTS:
Six hundred and eight studies met the inclusion criteria, and finally, 68 unique studies were available for the systematic review. Quantitative results were heterogeneous. The pivot shift test has been quantified by means of 25 parameters, but most of the studies focused on anterior-posterior translations, internal-external rotation and acceleration in anterior-posterior direction.
CONCLUSION:
Several methodologies have been identified and developed to quantify pivot shift test. However, clinical professionals are still lacking a 'gold standard' method for the quantification of knee joint dynamic laxity. A widespread adoption of a standardized pivot shift manoeuvre and measurement method to allow objective comparison of the results of ACL reconstructions is therefore desirable. Further development of measurement methods is indeed required to achieve this goal in a routine clinical scenario
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
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