1,038 research outputs found

    Toward robust and predictive geodynamic modeling : the way forward in frictional plasticity

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    Strain localization is a fundamental characteristic of plate tectonics. The resulting deformation structures shape the margins of continents and the internal structure of tectonic plates. To model the occurrence of faulting, geodynamic models generally rely on frictional plasticity. Frictional plasticity is normally embedded in viscoā€plastic (Vā€P) or viscoā€elastoā€plastic (Vā€Eā€P) rheologies. This poses some fundamental issues, such as the difficulty, or often inability, to obtain a converged equilibrium state and a severe grid sensitivity. Here, we study shear banding at crustalā€scale using a viscoā€elastoā€viscoplastic (Vā€Eā€VP) model. We show that this rheology allows to accurately satisfy equilibrium, leads to shear band patterns that converge upon mesh refinement, and preserves characteristic shear band angles. Moreover, a comparison with analytic models and laboratory data reveals that Vā€Eā€VP rheology captures firstā€order characteristics of frictional plasticity. Vā€Eā€VP models thus overcomes limitations of Vā€P and Vā€Eā€P models and appears as an attractive alternative for geodynamic modeling

    Development and characterization of osteogenic cell sheets in an in vivo model

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    [Excerpt] Despite some successes in the tissue engineering field its evolution seems to be tampered by limitations such as cell sourcing and the lack of adequate scaffolds to support cell growth and differentiation. The use of stem cells combined with cell sheet engineering technology seems a promising way to overcome these limitations. In this work bone marrow cells were flushed from 3 weeks old Wistar rat femurs and cultured in basal DMEM medium until subconfluence. Cells were then transferred to thermo-responsive dishes (3 x10āµ cells/dish) and cultured for 3 weeks in osteogenic medium. [...]info:eu-repo/semantics/publishedVersio

    Generalized Bayesian Record Linkage and Regression with Exact Error Propagation

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    Record linkage (de-duplication or entity resolution) is the process of merging noisy databases to remove duplicate entities. While record linkage removes duplicate entities from such databases, the downstream task is any inferential, predictive, or post-linkage task on the linked data. One goal of the downstream task is obtaining a larger reference data set, allowing one to perform more accurate statistical analyses. In addition, there is inherent record linkage uncertainty passed to the downstream task. Motivated by the above, we propose a generalized Bayesian record linkage method and consider multiple regression analysis as the downstream task. Records are linked via a random partition model, which allows for a wide class to be considered. In addition, we jointly model the record linkage and downstream task, which allows one to account for the record linkage uncertainty exactly. Moreover, one is able to generate a feedback propagation mechanism of the information from the proposed Bayesian record linkage model into the downstream task. This feedback effect is essential to eliminate potential biases that can jeopardize resulting downstream task. We apply our methodology to multiple linear regression, and illustrate empirically that the "feedback effect" is able to improve the performance of record linkage.Comment: 18 pages, 5 figure

    Burial and exhumation in a subduction wedge : mutual constraints from thermo-mechanical modelin and natural P-T-t data (Sch. LustrƩs, W. Alps)

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    The dynamic processes leading to synconvergent exhumation of high-pressure low-temperature (HP-LT) rocks at oceanic accretionary margins, as well as the mechanisms maintaining nearly steady state regime in most accretion prisms, remain poorly understood. The present study aims at getting better constraints on the rheology, thermal conductivity, and chemical properties of the sediments in subduction zones. To reach that goal, oceanic subduction is modeled using a forward visco-elasto-plastic thermomechanical code (PARA(O)VOZ-FLAC algorithm), and synthetic pressure-temperature-time (P-T-t) paths, predicted from numerical experiments, are compared with natural P-T-t paths. The study is focused on the well constrained Schistes LustrĆ©s complex (SL: western Alps) which is thought to represent the fossil accretionary wedge of the Liguro-Piemontese Ocean. For convergence rates comparable to Alpine subduction rates (āˆ¼3 cm yrāˆ’1), the best-fitting results are obtained for high-viscosity, low-density wedge sediments and/or a strong lower continental crust. After a transition period of 3-5 Ma the modeled accretionary wedges reach a steady state which lasts over 20 Ma. Over that time span a significant proportion (āˆ¼35%) of sediments entering the wedge undergoes P-T conditions typical of the SL complex (āˆ¼15-20 kbar; 350-450Ā°C) with similar P-T loops. Computed exhumation rates (<6 mm yrāˆ’1) are in agreement with observations (1-5 mm yrāˆ’1). In presence of a serpentinite layer below the oceanic crust, exhumation of oceanic material takes place at rates approaching 3 mm yrāˆ’1. In all experiments the total pressure in the accretionary wedge never deviated by more than Ā±10% from the lithostatic component

    Development of osteogenic cell sheets for bone tissue engineering applications

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    The use of scaffolds in combination with osteogenic cells has been the gold standard in bone tissue engineering strategies. These strategies have, however, in many cases failed to produce the desired results due to issues such as the immunogenicity of the biomaterials used and cell necrosis at the bulk of the scaffold related to deficient oxygen and nutrients diffusion. Here, we originally propose the use of cell sheet (CS) engineering as a possible way to overcome some of these obstacles. Osteogenic CSs were fabricated by culturing rat bone marrow stromal cells in thermoresponsive culture dishes. The CSs were recovered from the dishes using a low-temperature treatment and then were implanted subcutaneously in nude mice. New bone formation was verified from day 7 post-transplantation using X-ray, microcomputed tomography, and histological analysis. The presence of a vascularized marrow was also verified in the newly formed bone after 6 weeks of transplantation. Further, osteocytes were found in this newly formed tissue, supporting the conclusion that mature bone was formed after ectopically transplanting osteogenic CSs. These results therefore confirm the great potentiality of CS engineering to be used in bone tissue engineering applicationsThis study was partially supported by Formation of Innovation Center for Fusion of Advanced Technologies in the Special Coordination Funds for Promoting Science and Technology "Cell Sheet Tissue Engineering Center (CSTEC)" and the Global COE program, Multidisciplinary Education and Research Center for Regenerative Medicine (MER-CREM), from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan.Financial support to R. P. Pirraco by the Portuguese Foundation for Science and Technology (FCT) through the PhD grant SFRH/BD/44893/2008 is also acknowledged

    Physical activity and education about physical activity for chronic musculoskeletal pain in children and adolescents

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    This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:. To evaluate the effectiveness of physical activity or education about physical activity, or both, compared to active medical care, waiting list, or usual care in children and adolescents with chronic musculoskeletal pain.National Institute for Health Research (NIHR), via Cochrane Infrastructure funding to the Cochrane Pain, Palliative and Supportive Care Review Group (PaPaS)

    Improving Completeness and Transparency of Reporting in Clinical Trials Using the Template for Intervention Description and Replication (TIDieR) Checklist Will Benefit the Physiotherapy Profession

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    Incomplete reporting of interventions in physiotherapy studies is an important problem and The Journal of Manual and Manipulative Therapy endorses the use of the TIDieR checklist as a potential solution

    "How do pilates trained physiotherapists utilize and value pilates exercise for MSK conditions? A qualitative study"

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    Background Pilates is a popular exercise therapy approach offering numerous benefits, including muscular strength, flexibility, control, and core stability. Pilates has been widely utilized in the prevention and rehabilitation of a variety of musculoskeletal disorders. Objectives The aim of this study was to explore the experiences and opinions of Pilates trained NHS and private practice physiotherapists in the UK, regarding the perceived benefits, risks, delivery and rationale for this exercise method. Methods This qualitative study used a selfā€designed electronic survey to retrieve the views of 30 physiotherapists, who had undertaken formal Pilates Instruction training, recruited by a purposive and snowball sampling method. Questions were either multiple choice or openā€ended, examined via thematic analysis. Results Physiotherapists identified the most important benefits of Pilates as reduction in fearā€avoidance, improving bodily awareness and increasing muscular strength. Exercises that promote general movement were highlighted as being particularly useful, with a majority recommending daily practice for optimum benefit. Participants recognized lack of core strength as a key indicator, whereas others criticized excessive focus on this principle. Conclusions Physiotherapists identified a range of interā€linked benefits and recognized that Pilates is hugely modifiable. Individualizing exercises can further encourage participation and negate the restriction of some health conditions. NHS and Private Practice Therapists utilize Pilates in a similar way, although rationales for its use may differ, as the justification for Pilates exercise may be evolving. Pilates appears a valuable methodology in the NHS, which can help patients engage with activity

    Effective Launch-to-Capture Power Reduction for LOS Scheme with Adjacent-Probability-Based X-Filling

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    It has become necessary to reduce power during LSI testing. Particularly, during at-speed testing, excessive power consumed during the Launch-To-Capture (LTC) cycle causes serious issues that may lead to the overkill of defect-free logic ICs. Many successful test generation approaches to reduce IR-drop and/or power supply noise during LTC for the launch-off capture (LOC) scheme have previously been proposed, and several of X-filling techniques have proven especially effective. With X-filling in the launch-off shift (LOS) scheme, however, adjacent-fill (which was originally proposed for shift-in power reduction) is used frequently. In this work, we propose a novel X-filling technique for the LOS scheme, called Adjacent-Probability-based X-Filling (AP-fill), which can reduce more LTC power than adjacent-fill. We incorporate AP-fill into a post-ATPG test modification flow consisting of test relaxation and X-filling in order to avoid the fault coverage loss and the test vector count inflation. Experimental results for larger ITC\u2799 circuits show that the proposed AP-fill technique can achieve a higher power reduction ratio than 0-fill, 1-fill, and adjacent-fill.2011 Asian Test Symposium, 20-23 November 2011, New Delhi, Indi
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