How does the knowledge environment shape procurement practices for orthopaedic medical devices in Mexico?

BACKGROUND: In organisational theory there is an assumption that knowledge is used effectively in healthcare systems that perform well. Actors in healthcare systems focus on managing knowledge of clinical processes like, for example, clinical decision-making to improve patient care. We know little about connecting that knowledge to administrative processes like high-risk medical device procurement. We analysed knowledge-related factors that influence procurement and clinical procedures for orthopaedic medical devices in Mexico. METHODS: We based our qualitative study on 48 semi-structured interviews with various stakeholders in Mexico: orthopaedic specialists, government officials, and social security system managers or administrators. We took a knowledge-management related perspective (i) to analyse factors of managing knowledge of clinical procedures, (ii) to assess the role of this knowledge and in relation to procurement of orthopaedic medical devices, and (iii) to determine how to improve the situation. RESULTS: The results of this study are primarily relevant for Mexico but may also give impulsion to other health systems with highly standardized procurement practices. We found that knowledge of clinical procedures in orthopaedics is generated inconsistently and not always efficiently managed. Its support for procuring orthopaedic medical devices is insufficient. Identified deficiencies: leaders who lack guidance and direction and thus use knowledge poorly; failure to share knowledge; insufficiently defined formal structures and processes for collecting information and making it available to actors of health system; lack of strategies to benefit from synergies created by information and knowledge exchange. Many factors are related directly or indirectly to technological aspects, which are insufficiently developed. CONCLUSIONS: The content of this manuscript is novel as it analyses knowledge-related factors that influence procurement of orthopaedic medical devices in Mexico. Based on our results we recommend that the procurement mechanism should integrate knowledge from clinical procedures adequately in their decision-making. Without strong guidance, organisational changes, and support by technological solutions to improve the generation and management of knowledge, procurement processes for orthopaedic high-risk medical devices will remain sub-optimal

THE EFFECT OF ANTAGONIST CONDITIONING CONTRACTIONS ON LOWER AND UPPER BODY POWER TESTS

This study assessed the effect of antagonist conditioning contractions (ACC) on lower and upper body power tests. Six subjects performed the bilateral countermovement jump and the supine medicine ball chest throw on a force platform in baseline conditions and after ACC. A repeated measures ANOVA was used to compare performance between the baseline conditions and the ACC condition. Analysis demonstrated no significant main effects for GRF (p = 0.41) or RFD (p = 0.55) for the countermovement jump. Additionally, there were no significant main effects for GRF (p = 0.85) or RFD (p = 0.95) for the medicine ball throw. This study demonstrated that maximal short term ACC do not enhance multi-joint power tests such as the countermovement jump and medicine ball throw

THE OSTEOGENIC POTENTIAL OF SUPERMAXIMAL SQUAT LOADS

This study evaluated the ground reaction force (GRF) and rate of force development (RFD) of the back squat at 3 different loads. Twelve subjects performed the back squat with 80%, 100%, and 120% of their 1 repetition maximum (RM) on a force platform. A two way repeated measures ANOVA revealed significant main effects for GRF for both the eccentric (p &#8804; 0.001) and concentric (p &#8804; 0.001) phases but no interaction between phase and GRF or RFD (p < 0.05). No significant main effects were found for RFD for the eccentric (p = 0.09) and concentric phases (p = 0.38). Post hoc analyses demonstrated that back squats at 120% produced the highest GRF in the eccentric and concentric conditions. Mean RFD was highest, and trending toward significance, during the eccentric phase at 100% of 1 RM condition

Population structure of Canarium labiatum (Röding, 1798) (Mollusca: Neostromboidae: Strombidae) on Green Island, Great Barrier Reef, Queensland

Canarium labiatum is a small gastropod of the Strombidae family that is commonly encountered in the inter-tidal zones of tropical Queensland, Australia, yet little is known of its population structure. A targeted survey of the Canarium labiatum population on Green Island, located near Cairns, Queensland, was conducted on 12 August 2015. Ninety adult specimens were collected, of which 49 were female and 41 were male. The sample demonstrated significant sexual axiallength size dimorphism, with a bias towards larger females. While we collected more females than males, this did not represent a statistically significant bias, and rather may reflect the clustering nature of the sample. In addition, there was no evidence of pseudohermaphroditism in females within the population under consideration. Interestingly, 11.1% of the sample did not show banding and brown/grey-blue maculations on a light grey shell, the typical colour pattern associated with Canarium labiatum. This paper fills a knowledge gap in Queensland’s Canarium labiatum population structure and provides a basis for a wider study into the size dynamics of Strombidae in general, but Canarium in particular

A two-species continuum model for aeolian sand transport

Starting from the physics on the grain scale, we develop a simple continuum description of aeolian sand transport. Beyond popular mean-field models, but without sacrificing their computational efficiency, it accounts for both dominant grain populations, hopping (or "saltating") and creeping (or "reptating") grains. The predicted stationary sand transport rate is in excellent agreement with wind tunnel experiments simulating wind conditions ranging from the onset of saltation to storms. Our closed set of equations thus provides an analytically tractable, numerically precise, and computationally efficient starting point for applications addressing a wealth of phenomena from dune formation to dust emission.Comment: 23 pages, 9 figure

Incommensuration Effects and Dynamics in Vortex Chains

We examine the motion of one-dimensional (1D) vortex matter embedded in a 2D vortex system with weak pinning using numerical simulations. We confirm the conjecture of Matsuda et al. [Science 294, 2136 (2001)] that the onset of the temperature induced motion of the chain is due to an incommensuration effect of the chain with the periodic potential created by the bulk vortices. In addition, under an applied driving force we find a two stage depinning transition, where the initial depinning of the vortex chain occurs through soliton like pulses. When an ac drive is added to the dc drive, we observe phase locking of the moving vortex chain.Comment: 4 pages, 4 postscript figure

Report of the ICES\NAFO Joint Working Group on Deep-water Ecology (WGDEC), 11–15 March 2013, Floedevigen, Norway.

On 11 February 2013, the joint ICES/NAFO WGDEC, chaired by Francis Neat (UK) and attended by ten members met at the Institute for Marine Research in Floedevi-gen, Norway to consider the terms of reference (ToR) listed in Section 2. WGDEC was requested to update all records of deep-water vulnerable marine eco-systems (VMEs) in the North Atlantic. New data from a range of sources including multibeam echosounder surveys, fisheries surveys, habitat modelling and seabed imagery surveys was provided. For several areas across the North Atlantic, WGDEC makes recommendations for areas to be closed to bottom fisheries for the purposes of conservation of VMEs

The Effect of Air on Granular Size Separation in a Vibrated Granular Bed

Using high-speed video and magnetic resonance imaging (MRI) we study the motion of a large sphere in a vertically vibrated bed of smaller grains. As previously reported we find a non-monotonic density dependence of the rise and sink time of the large sphere. We find that this density dependence is solely due to air drag. We investigate in detail how the motion of the intruder sphere is influenced by size of the background particles, initial vertical position in the bed, ambient pressure and convection. We explain our results in the framework of a simple model and find quantitative agreement in key aspects with numerical simulations to the model equations.Comment: 14 pages, 16 figures, submitted to PRE, corrected typos, slight change

A stochastic flow rule for granular materials

There have been many attempts to derive continuum models for dense granular flow, but a general theory is still lacking. Here, we start with Mohr-Coulomb plasticity for quasi-2D granular materials to calculate (average) stresses and slip planes, but we propose a "stochastic flow rule" (SFR) to replace the principle of coaxiality in classical plasticity. The SFR takes into account two crucial features of granular materials - discreteness and randomness - via diffusing "spots" of local fluidization, which act as carriers of plasticity. We postulate that spots perform random walks biased along slip-lines with a drift direction determined by the stress imbalance upon a local switch from static to dynamic friction. In the continuum limit (based on a Fokker-Planck equation for the spot concentration), this simple model is able to predict a variety of granular flow profiles in flat-bottom silos, annular Couette cells, flowing heaps, and plate-dragging experiments -- with essentially no fitting parameters -- although it is only expected to function where material is at incipient failure and slip-lines are inadmissible. For special cases of admissible slip-lines, such as plate dragging under a heavy load or flow down an inclined plane, we postulate a transition to rate-dependent Bagnold rheology, where flow occurs by sliding shear planes. With different yield criteria, the SFR provides a general framework for multiscale modeling of plasticity in amorphous materials, cycling between continuum limit-state stress calculations, meso-scale spot random walks, and microscopic particle relaxation