1,720,964 research outputs found
Predicting fatigue life of a PMMA based knee spacer using a multiaxial fatigue criterion
No full textPre-clinical Evaluation of the Biomechanical Behavior of ImplantableDevices for Orthopedic and Spinal Surgery
No full textThe assessment of the suitability of the
biomechanical performances of a medical device intended to
replace either a function or tissue, is a primary issue in the
pre-clinical evaluation of a new device. Such evaluation is
usually performed by means of either experimental facilities
or computational simulation or, better, by the interaction of
both the methodologies. Difficulties arise when trying to
combine the need of simulating the complexity of the
biological response to the implant with the necessity of
maintaining a reproducible and simple experimental
procedure. At LaBS, devices for the treatment of pathologies
of lower limbs and spine are subjected to purposely designed
experimental protocols and numerical simulations in order to
take into account requests regarding their anatomical,
functional and surgical compatibility, as well as their
mechanical reliability in time. Two examples of such preclinical
studies are here given: in particular the impact of
different surgical techniques used in the implant of an
interspinous device on its functional compatibility has been
investigated by means of an experimental animal model; the
fatigue resistances of the tibial tray of a polymethyl
methacrylate (PMMA) knee spacer have been predicted and
validated by means of a combined computational and
experimental procedure, using advanced stress criterion based
on stress invariant
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
Design of a "driven cylinder" viscometer for bone cement rheological characterization
No full text The long-term success of surgical applications requiring bone cement is strongly influenced by the cement’s rheological properties. Previous studies showed a clear non-Newtonian, pseudoplastic, time-dependent rheological behaviour of acrylic bone cement during the working time. However, the particular nature of this material raises issues about its rheological characterization: the aim of this paper is to develop a new device, called ‘driven cylinder’ viscometer, able to accomplish the rheological characterization of acrylic bone cement. Three different fluids were tested by using the ‘driven cylinder’ viscometer: (a) liquid soap, (b) low-viscosity bone cement, and (c) vertebroplasty bone cement. For the sake of comparison, the rheological behaviour of the fluids (a) and (b) was also evaluated using traditional viscometers. The developed device allowed evaluation of the constitutive rheological parameters for non-Newtonian, power-law fluids. Independent evaluation of the viscosity of liquid soap and low-viscosity bone cement carried out by means of parallel-plate rotational rheometers showed a good agreement with the trends obtained by the ‘driven cylinder’ viscometer. The device versatility suggests its application for a complete description of pseudoplastic and time-dependent rheological properties of acrylic bone cements, which is a mandatory step for virtual tools of cement-based surgical procedures. </jats:p
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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