1,721,088 research outputs found
Cadaver model compression data
No full textDataset contains repeated measures of screw placement torque and compression in synthetic and canine cadaver bone as described below.
Methods:
Pilot holes were drilled using an aiming device (IMEX veterinary, Inc., Longview, TX, USA) with a drill bit corresponding to the shaft diameter of each of the screws to undergo testing (2.0mm hole for 2.7mm screws and 2.5mm hole for 3.5mm screws). Points of entry and exit were centred halfway between the epicondyle and the articular surface of the condyle (18)(17). For the lag screw set-up, the glide hole was over-drilled in the lateral condylar fragment with a drill bit corresponding to the overall thread diameter of the appropriate screw.
Torque testing
Prior to compression testing, each screw was tightened to ‘stopping-torque’ by a single, blinded, board-certified surgical specialist. All screws were self-tapping cortical screws of 40mm length (Depuy synthes Vet, West Chester, PA, USA). Torque was measured by a digital torque screwdriver (0.05Nm-5Nm) (Sealey Tools, Bury, UK) which was used to tighten all screws. Each screw, with a washer, was applied into a newly drilled hole in the synthetic bone material for a total of five repeats (20pcf, 40mm diameter for the positional screw [PS] and 20pcf, 20mm diameter for the lag screw [LS]) and three timesfor three repeats in cadaver humeral condyles (whole condyle for PS, and just the medial component for LS). The mean value of the replicates was used as a standard torque for screw application in mechanical testing.
Part 1: Synthetic bone model mechanical testing protocol
A 25.4mm diameter circular piezoresistive force sensor (Tekscan Flexiforce A401; Tekscan, Boston, MA, USA) and load measurement system (Flexiforce ELF system; Tekscan, Boston, MA, USA) was used to measure compression. The sensors were modified by the manufacturers, with a 5mm central hole to accommodate the screw through the centre of the surface to be compressed. The sensor apparatus was calibrated, according to manufacturer guidelines, with a series of known weights prior to each use. The sensor was placed between the two blocks with the screw passing through the central hole. Compression (Newtons) was measured following application of the pointed reduction forceps, following screw placement and then after removal of the reduction forceps. The forceps were applied by the same surgeon, using points 5mm from the central hole. Each screw, with washer, was inserted and tightened by hand, to the previously specified torque as either a PS or LS. Washers were used to avoid deformation of the cis-cortex.
A new block was used for each individual test, with a total of five 20 PCF models per screw size, and per mode of insertion (2.7mm PS, 2.7mm LS, 3.5mm PS, 3.5mm LS, total 20 models tested).
Part 2: Cadaveric humeral lateral condylar fracture model mechanical testing protocol
Cadaver testing was performed with identical sensors in the same manner as in the bone model. In a clinical scenario, a screw of greater diameter is advantageous due to an increased area moment of inertia (AMI) and thus increased resistance to bending. In pilot testing, compression exerted by the 4.5mm screws exceeded the dynamic range of the sensors. Given that 4.5mm screws could not be tested, and 2.7mm screws are less desirable due to a decreased AMI, 3.5mm screws were selected for use in the cadaver limbs. Paired limbs were randomised; one side for PS placement and one side for LS placement. A new bone was used for each screw application. Reduction forceps were applied by the same surgeon, using the same landmarks (medial and lateral epicondyle). All screws were placed from lateral to medial. The dataset relates to the upcoming publication Winter, J., Clements, D.N., Ryan, J.R. (in submission), "Preliminary assessment of compression achieved by pre-loaded lag screw and pre-loaded positional screw in a lateral humeral condylar fracture model"
Cyclic compression of canine joint cells - microarray data
No full textCells are agarose embedded and cyclically compressed on FXC compression bioreactor for 4 hours followed by 24 hours of recovery incubation. RNA extracted according to Bougault et al (2008) and canine microarray performedJohnson, Craig; Clements, Dylan. (2016). Cyclic compression of canine joint cells - microarray data, [dataset]. Roslin Institute, University of Edinburgh
Stimulation of canine joint cells to model osteoarthritis
No full textCanine chondrocytes and osteoblasts were embedded in an agarose matrix and simultaneously stimulated with cytokines whilst being cyclically compressed. Both cell types were compressed for 4 hours at 1 Hz followed by a 24 hour recovery incubation. The chondrocytes were stimulated with 5 ng/mL of IL8 for the duration of compression, but removed for the recovery phase. Osteoblasts were stimulated with 0.5 ng/mL IL8 and 0.5 ng/mL IL1b for the duration of the compression and for the entirety of the 24 hour incubation step.Johnson, Craig; Clements, Dylan. (2016). Stimulation of canine joint cells to model osteoarthritis, [dataset]. Roslin Institute, University of Edinburgh
Cytokine stimulation of canine chondrocytes and osteoblasts
No full textIn vitro modelling of osteoarthritis typically uses cytokines to induce a catabolic phenotype in joint cells. This model was used to identify the response to a cytokine parameter identified as most representative of early stage osteoarthritis. Canine cells were used, isolated from the humeral head of post-mortem subjects. The cartilage cells were stimulated with 5 ng/ml of IL8 for 2 hours, whilst the osteoblasts were stimulated with 500 pg/mL of IL1 and 500 pg/mL of IL8. After the indicated culture time, RNA was extracted and a microarray was performed to identify gene expression changes.Johnson, Craig; Clements, Dylan. (2016). Cytokine stimulation of canine chondrocytes and osteoblasts, [dataset]. University of Edinburgh. College of Medicine and Veterinary Medicine. Roslin Institute
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
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