954 research outputs found

    An airfoil for general aviation applications

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    A new airfoil, the NLF(1)-0115, has been recently designed at the NASA Langley Research Center for use in general-aviation applications. During the development of this airfoil, special emphasis was placed on experiences and observations gleaned from other successful general-aviation airfoils. For example, the flight lift-coefficient range is the same as that of the turbulent-flow NACA 23015 airfoil. Also, although beneficial for reducing drag and having large amounts of lift, the NLF(1)-0115 avoids the use of aft loading which can lead to large stick forces if utilized on portions of the wing having ailerons. Furthermore, not using aft loading eliminates the concern that the high pitching-moment coefficient generated by such airfoils can result in large trim drags if cruise flaps are not employed. The NASA NLF(1)-0115 has a thickness of 15 percent. It is designed primarily for general-aviation aircraft with wing loadings of 718 to 958 N/sq m (15 to 20 lb/sq ft). Low profile drag as a result of laminar flow is obtained over the range from c sub l = 0.1 and R = 9x10(exp 6) (the cruise condition) to c sub l = 0.6 and R = 4 x 10(exp 6) (the climb condition). While this airfoil can be used with flaps, it is designed to achieve c(sub l, max) = 1.5 at R = 2.6 x 10(exp 6) without flaps. The zero-lift pitching moment is held at c sub m sub o = 0.055. The hinge moment for a .20c aileron is fixed at a value equal to that of the NACA 63 sub 2-215 airfoil, c sub h = 0.00216. The loss in c (sub l, max) due to leading edge roughness, rain, or insects at R = 2.6 x 10 (exp 6) is 11 percent as compared with 14 percent for the NACA 23015

    No equity, no triple aim: strategic proposals to advance health equity in a volatile policy environment

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    Health professionals, including social workers, community health workers, public health workers, and licensed health care providers, share common interests and responsibilities in promoting health equity and improving social determinants of health—the conditions in which we live, work, play, and learn. This article summarizes underlying causes of health inequity and comparatively poor health outcomes in the U.S. It describes barriers to realizing the hope embedded in the 2010 Patient Protection and Affordable Care Act that moving away from fee-for-service payments will naturally drive care upstream as providers respond to greater financial risk for the health of their patients by undertaking greater prevention efforts. The article asserts that health equity should serve as the guiding framework for achieving the Triple Aim of health care reform. It outlines practical opportunities for improving care and for promoting stronger efforts to address social determinants of health. These proposals include developing a dashboard of measures to assist providers committed to health equity and community-based prevention and to promote institutional accountability for addressing socio-economic factors that influence health

    No equity, no triple aim: strategic proposals to advance health equity in a volatile policy environment

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    Health professionals, including social workers, community health workers, public health workers, and licensed health care providers, share common interests and responsibilities in promoting health equity and improving social determinants of health—the conditions in which we live, work, play, and learn. This article summarizes underlying causes of health inequity and comparatively poor health outcomes in the U.S. It describes barriers to realizing the hope embedded in the 2010 Patient Protection and Affordable Care Act that moving away from fee-for-service payments will naturally drive care upstream as providers respond to greater financial risk for the health of their patients by undertaking greater prevention efforts. The article asserts that health equity should serve as the guiding framework for achieving the Triple Aim of health care reform. It outlines practical opportunities for improving care and for promoting stronger efforts to address social determinants of health. These proposals include developing a dashboard of measures to assist providers committed to health equity and community-based prevention and to promote institutional accountability for addressing socio-economic factors that influence health

    The development of an accreditation scheme for accredited exercise physiologists

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    Background: Accredited Exercise Physiologists provide exercise services for people living with chronic disease, disability or injury and are recognised in Australia as Accredited Exercise Physiologists (AEP) under a national certification system administered by Exercise and Sport Science Australia (ESSA). A major breakthrough occurred for the AEP in 2006 when the Australian Department of Health and Ageing approved the AEP to deliver clinical exercise services for people with chronic medical conditions under the taxpayer-funded national health scheme, Medicare Australia. Aims: In light of these developments, the authors recognised the need for new accreditation criteria, and our report summarises the work that we did on behalf of the profession and ESSA in restructuring the accreditation system. Methods and Outcomes: We first performed a background study that defined the scope of practice of the AEP and benchmarked the AEP against other allied health professions in Australia and Clinical Exercise Physiologists internationally. We then constructed a new set of accreditation criteria comprising sets of pathologyspecific knowledge and experiences, together with a set of generic standards including communication, professional behaviour and risk management. All participating Australian universities (18 out of 27 responded) and 29 practitioner experts were then invited to provide comment and input into the draft guidelines. There was strong support for the new system that was implemented nationally on 1 January 2008 and is now administered by ESSA. Conclusions: This work has stimulated an unprecedented level of activity in the Australian university sector in developing new curricula in clinical exercise science and practice, and is intended to lead to improved standards of clinical exercise practice.<br /

    Differential neuroproteomic and systems biology analysis of spinal cord injury

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    Acute spinal cord injury (SCI) is a devastating condition with many consequences and no known effective treatment. Although it is quite easy to diagnose traumatic SCI, the assessment of injury severity and projection of disease progression or recovery are often challenging, as no consensus biomarkers have been clearly identified. Here rats were subjected to experimental moderate or severe thoracic SCI. At 24h and 7d postinjury, spinal cord segment caudal to injury center versus sham samples was harvested and subjected to differential proteomic analysis. Cationic/anionic-exchange chromatography, followed by 1D polyacrylamide gel electrophoresis, was used to reduce protein complexity. A reverse phase liquid chromatography-tandem mass spectrometry proteomic platform was then utilized to identify proteome changes associated with SCI. Twenty-two and 22 proteins were up-regulated at 24 h and 7 day after SCI, respectively; whereas 19 and 16 proteins are down-regulated at 24 h and 7 day after SCI, respectively, when compared with sham control. A subset of 12 proteins were identified as candidate SCI biomarkers - TF (Transferrin), FASN (Fatty acid synthase), NME1 (Nucleoside diphosphate kinase 1), STMN1 (Stathmin 1), EEF2 (Eukaryotic translation elongation factor 2), CTSD (Cathepsin D), ANXA1 (Annexin A1), ANXA2 (Annexin A2), PGM1 (Phosphoglucomutase 1), PEA15 (Phosphoprotein enriched in astrocytes 15), GOT2 (Glutamic-oxaloacetic transaminase 2), and TPI-1 (Triosephosphate isomerase 1), data are available via ProteomeXchange with identifier PXD003473. In addition, Transferrin, Cathepsin D, and TPI-1 and PEA15 were further verified in rat spinal cord tissue and/or CSF samples after SCI and in human CSF samples from moderate/severe SCI patients. Lastly, a systems biology approach was utilized to determine the critical biochemical pathways and interactome in the pathogenesis of SCI. Thus, SCI candidate biomarkers identified can be used to correlate with disease progression or to identify potential SCI therapeutic targets

    LES and FW-H Prediction of Aeroacoustic Noise for a SD 7037 Airfoil for Wind Turbine Applications

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    The aeroacoustic noise generated by wind turbines poses issues with the implementation of this renewable energy technology. The use of a fully analytical model for predicting airfoil noise could serve as a crucial tool in the design phase of new turbines or noise reduction technologies. This work uses a combination of Large Eddy Simulation (LES) and the Ffowcs-Williams and Hawkings (FW-H) acoustic model to predict the noise generated by a 2D segment of the SD 7037(c) airfoil. The simulations are performed at a static angle of attack (AOA) and at a Reynolds number typical for small scale wind turbines of Re = 4.3×10⁴. The flow and acoustic results are validated against experimental results conducted by the Wind Energy Group at the University of Waterloo. This model was able to accurately predict the flow field and acoustic results for the 0° AOA, and determined the source of the 4.1 kHz tone to be 2D vortex shedding from the trailing edge (TE) and the 3.4 kHz tone to come from the transition from 2D to 3D boundary layer behaviour. The 1° AOA simulation, while able to simulate the flow and broadband acoustic spectra, requires further investigation to simulate the complex boundary layer transition behaviours required to predict the 3.4 kHz tone. Overall, this method proved to be an effective predictive tool for airfoil self-noise at static AOAs.Natural Science and Engineering Research Council || Ontario Graduate Scholarship Program || TD Bank Graduate Scholarship in the Environment

    Biology of advanced uveal melanoma and next steps for clinical therapeutics

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    Uveal melanoma is the most common intraocular malignancy although it is a rare subset of all melanomas. Uveal melanoma has distinct biology relative to cutaneous melanoma, with widely divergent patient outcomes. Patients diagnosed with a primary uveal melanoma can be stratified for risk of metastasis by cytogenetics or gene expression profiling, with approximately half of patients developing metastatic disease, predominately hepatic in location, over a 15-yr period. Historically, no systemic therapy has been associated with a clear clinical benefit for patients with advanced disease, and median survival remains poor. Here, as a joint effort between the Melanoma Research Foundation's ocular melanoma initiative, CURE OM and the National Cancer Institute, the current understanding of the molecular and immunobiology of uveal melanoma is reviewed, and on-going laboratory research into the disease is highlighted. Finally, recent investigations relevant to clinical management via targeted and immunotherpies are reviewed, and next steps in the development of clinical therapeutics are discussed

    A geometrical introduction to screw theory

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    This work introduces screw theory, a venerable but yet little known theory aimed at describing rigid body dynamics. This formulation of mechanics unifies in the concept of screw the translational and rotational degrees of freedom of the body. It captures a remarkable mathematical analogy between mechanical momenta and linear velocities, and between forces and angular velocities. For instance, it clarifies that angular velocities should be treated as applied vectors and that, under the composition of motions, they sum with the same rules of applied forces. This work provides a short and rigorous introduction to screw theory intended to an undergraduate and general readership.Comment: Latex2e, 24 pages. v2: expanded introduction, added 2 figure

    On the Exponentials of Some Structured Matrices

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    In this note explicit algorithms for calculating the exponentials of important structured 4 x 4 matrices are provided. These lead to closed form formulae for these exponentials. The techniques rely on one particular Clifford Algebra isomorphism and basic Lie theory. When used in conjunction with structure preserving similarities, such as Givens rotations, these techniques extend to dimensions bigger than four.Comment: 19 page
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