1,721,135 research outputs found
Standardization of hemipelvis alignment for in vitro biomechanical testing
Full text linkAlthough in vitro biomechanical tests are regularly performed, the definition of a suitable reference frame for hemipelvic specimens is still a challenge. The aims of the present study were to: (i) define a reference frame for the human hemipelvis suitable for in vitro applications, based on robust anatomical landmarks; (ii) identify the alignment of a hemipelvis based on the alignment of a whole pelvis (including right/left and male/female differences); (iii) identify the relative alignment of the proposed in vitro reference frame with respect to a reference frame commonly used in gait analysis; (iv) create an in vitro alignment procedure easy, robust and inexpensive; (v) quantify the intra-operator repeatability and inter-operator reproducibility of the procedure. A procedure to univocally identify the anatomical landmarks was created, exploiting the in vitro accessibility of the specimen's surface. Through the analysis on 53 CT scans (106 hemipelvises), the alignment of the hemipelvis based on the alignment of a whole pelvis was analyzed: differences between male/female and right/left hemipelvises were not statistically significant To overcome the uncertainty in the identification of the acetabular rim, a standard acetabular plane was defined. An alignment procedure was developed to implement such anatomical reference frame. The intra-operator repeatability and the inter-operator reproducibility were quantified with four operators, on male and female hemipelvises. The intra-operator repeatability was better than 1.5°. The inter-operator reproducibility was better than 2.0°. Alignment in the transverse plane was the most repeatable. The presented procedure to align hemipelvic specimens is sufficiently robust, standardized, and accessible. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1645–1652, 2018
Indagine sperimentale finalizzata alla individuazione di un criterio di progetto per la stabilizzazione delle terre con calce
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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
Environmental commitment of large US publicly traded companies producing healthcare equipment: a cross-sectional comparative study
No full textThe environmental commitment of healthcare stakeholders is poorly described despite the sector pollution and the social needs of more sustainable behaviors. A cross-sectional study comparing the environment commitment of US publicly traded companies producing healthcare equipment (HE), healthcare companies (H), and large capitalization corporates (LC) was designed. Using a financial database, the 20 largest US publicly traded companies by market capitalization were selected for each cohort. The last available sustainability report was investigated, aiming to assess (1) the year and the method of dissemination of the last report; (2) the adhesion to environmental standards; (3) the presence of environmental policies, quantitative targets, and tracking; (4) the third-party evaluations about company environmental sustainability. HE companies published sustainability reports in time (p = 0.048), usually as standalone reports (p < 0.001). Half of HE companies adhered to standards, less than the control groups (p < 0.001). HE companies had an acceptable environmental policy, improving over the time and posing targets, similarly to control groups (p > 0.05). The number of companies reporting quantitative targets/tracking about carbon footprint, water, and renewable energy managements differed among the three cohorts (p = 0.013, p = 0.013, and p < 0.001, respectively), with HE cohort achieving the lowest rates (70%, 70%, and 50%, respectively). Carbon neutrality and all renewable energy statements were rare among HE companies (10% and 5% of companies, p < 0.007). In HE, CDP (The Carbon Disclosure Project) scores were lower than controls (p < 0.001). US publicly traded companies producing healthcare equipment demonstrated to be far less committed to environmental sustainability than healthcare companies and large capitalization corporates. Level of evidence: I
One-stage release by double surgical approach for neglected congenital vertical talus: results in a series of walking children in Tanzania
No full textCongenital vertical talus is an uncommon rigid flatfoot deformity present at birth, producing pain and disability if untreated. This study reports results and complications in a series of walking children affected by neglected congenital vertical talus treated by one-stage release through a double surgical approach in a hospital sited in the Tanzanian rural outback. Between 2009 and 2014, nine consecutive congenital vertical talus were observed in five patients (three males and two females) aged between 2 and 4 years. In two children, the deformity was idiopathic, in two it was associated to distal arthrogryposis and in one to Larsen syndrome. The surgical procedure was performed through a posteromedial and a lateral incision and included extensive soft tissue release and reduction of talo-navicular and subtalar joint, pinned with percutaneous Kirschner wires. The talar axis-first metatarsal base angle (TAMBA) was measured preoperatively and at follow-up. Results were summarized using the Adelaar score and the PODCI (Pediatric Outcomes Data Collection Instrument) questionnaire. The mean follow-up was 2.6 years (2-4). No major intraoperative complications were observed. The TAMBA passed from 74.4° (range 68-82°) to 20.2° (range 18-24°). No talar osteonecrosis was observed. The results were excellent in three cases, good in five cases and fair in one (Adelaar score). The mean postoperative PODCI score was 48 (range 38-60). None of the patients underwent further surgery. In case of neglected congenital vertical talus and limited health resources, this surgical technique has proved to be a viable option, providing satisfactory results, with low rate of surgical and postsurgical complications
Effect of cup medialization on primary stability of press-fit acetabular cups
Full text linkBackground: Appropriate restoration of the native centre of rotation is of paramount importance in total hip arthroplasty. Reconstruction of the centre of rotation depends on reaming technique: conventional approaches require more cup medialization than anatomical preparations. To date, the influence of cup medialization on socket stability in cementless implants is still unknown. Methods: Ten cadaveric hemipelvises were sequentially reamed using anatomical technique (only subchondral bone removal with restoration of the native centre of rotation) and conventional preparation (reaming to the lamina and medializing the cup). A biomechanical test was performed on the reconstructions. Implant motions were measured with digital image correlation while a cyclic load of increasing magnitude was applied. Findings: No significant difference was measured between the two implantation techniques in terms of permanent cup migrations. The only significant difference was found for the cup inducible rotations, where the conventional technique was associated with larger rotations. Interpretation: Conventional reaming and cup medialization do not improve initial cup stability. Beyond the recently questioned concerns about medialization and hip biomechanics, this is another issue to bear in mind when reaming the acetabulum
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
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