879 resultados para Conservative powertheory
Resumo:
The aim of this study was to prospectively assess the prevalence of orthoptic anomalies following conservative management of pure blowout orbital fractures and to evaluate their clinical relevance. Clinical and radiologic data of patients with unilateral conservatively managed pure blowout orbital fractures with a minimum follow-up of 6 months were reviewed. Eligible patients were contacted and invited to undergo an extended ophthalmologic examination as follows: distance and near visual acuities, Hertel exophthalmometry, corneal light reflex (Hirschberg test), ductions and versions in the 6 cardinal fields of gaze, eye deviation with prisms and alternate cover test in all of the 9-gaze directions with Maddox rod, degrees of incyclo/excyclotorsion with right and left eye fixation, horizontal and vertical deviation with Hess-Weiss coordimetry, degree of horizontal/vertical and incyclo/excyclotorsion deviation with Harms wall deviometry, and vertical deviation with Bielschowsky head-tilt test. Of the 69 patients contacted, 49 declined to participate given that they were asymptomatic. Twenty patients agreed to undergo the examination. One patient complained of minimal double vision limited to the extreme downgaze. Four patients had asymptomatic ocular motility disturbances limited to the extreme gaze. Seven patients had asymptomatic horizontal heterophoria. These disturbances did not interfere with daily or professional activities in any of the patients. The current study demonstrated that conservative management of pure orbital blowout fractures can result in orthoptic anomalies. These sequelae were restricted to a very limited portion of the binocular field of the vision and were not found to be clinically relevant.
Resumo:
We analyzed the nutritional composition and isotope ratios (C and N) of big-leaf mahogany (Swietenia macrophylla King) leaves in plantations established on contrasting soils and climates in Central America (State of Quintana Roo, Yucatán, México) and South America (State of Pará, Brazil). The objective was to determine the adaptability of this species to large differences in nutrient availability and rainfall regimes. Nutrient concentrations of leaves and soils were determined spectrophotometrically, and isotope ratios were measured using mass spectrometric techniques.In Pará soils were sandier, and acidic, receiving above 2000 mm of rain, whereas in Quintana Roo soils were predominantly clayey, with neutral to alkaline pH due to the underlying calcareous substrate, with about 1300 mm of rain. Leaf area/weight ratio was similar for both sites, but leaves from Quintana Roo were significantly smaller. Average N and K concentrations of adult leaves were similar, whereas Ca concentration was only slightly lower in Pará in spite of large differences in Ca availability. Leaves from this site had slightly higher P and lower Al concentrations. Differences in water use efficiency as measured by the natural abundance of 13C were negligible, the main effect of lower rainfall in Quintana Roo seemed to be a reduction in leaf area. The N isotope signature (δ15N) was more positive in Pará than in Quintana Roo, suggesting higher denitrification rates in the former. Results reveal a calciotrophic behavior and a remarkable capacity of mahogany to compensate for large differences in soil texture and nutrient availability.
Resumo:
We performed a systematic review and meta-analysis of randomized controlled trials that studied the conservative management of stress urinary incontinence (SUI). There were 1058 results after the initial searches, from which 37 studies were eligible according to previously determined inclusion criteria. For the primary outcomes, pelvic floor muscle training (PFMT) was more efficacious than no treatment in improving incontinence-specific quality of life (QoL) scales (SMD = [1]1.24SDs; CI 95% = [1]1.77 to [1]0.71SDs). However, its effect on pad tests was imprecise. Combining biofeedback with PFMT had an uncertain effect on QoL (MD = [1]4.4 points; CI 95% = [1]16.69 to 7.89 points), but better results on the pad test, although with elevated heterogeneity (MD = 0.9g; 95%CI = 0.71 to 1,10g); group PFMT was not less efficacious than individual treatment, and home PFMT was not consistently worse than supervised PFMT. Both intravaginal and superficial electrical stimulation (IES and SES) were better than no treatment for QoL and pad test. Vaginal cones had mixed results. The association of IES with PFMT may improve the efficacy of the latter for QoL and pad test, but the results of individual studies were not consistent. Thus, there is evidence of the use of PFMT on the treatment of SUI, with and without biofeedback.
Resumo:
Current immunological opinion disdains the necessity to define global interconnections between lymphocytes and regards natural autoantibodies and autoreactive T cells as intrinsically pathogenic. Immunological theories address the recognition of foreignness by independent clones of lymphocytes, not the relations among lymphocytes or between lymphocytes and the organism. However, although extremely variable in cellular/molecular composition, the immune system preserves as invariant a set of essential relations among its components and constantly enacts contacts with the organism of which it is a component. These invariant relations are reflected, for example, in the life-long stability of profiles of reactivity of immunoglobulins formed by normal organisms (natural antibodies). Oral contacts with dietary proteins and the intestinal microbiota also result in steady states that lack the progressive quality of secondary-type reactivity. Autoreactivity (natural autoantibody and autoreactive T cell formation) is also stable and lacks the progressive quality of clonal expansion. Specific immune responses, currently regarded as the fundament of the operation of the immune system, may actually result from transient interruptions in this stable connectivity among lymphocytes. More permanent deficits in interconnectivity result in oligoclonal expansions of T lymphocytes, as seen in Omenn's syndrome and in the experimental transplantation of a suboptimal diversity of syngeneic T cells to immunodeficient hosts, which also have pathogenic consequences. Contrary to theories that forbid autoreactivity as potentially pathogenic, the physiology of the immune system is conservative and autoreactive. Pathology derives from failures of these conservative mechanisms.
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In recent years, reversible logic has emerged as one of the most important approaches for power optimization with its application in low power CMOS, nanotechnology and quantum computing. This research proposes quick addition of decimals (QAD) suitable for multi-digit BCD addition, using reversible conservative logic. The design makes use of reversible fault tolerant Fredkin gates only. The implementation strategy is to reduce the number of levels of delay there by increasing the speed, which is the most important factor for high speed circuits.
Resumo:
The discontinuities in the solutions of systems of conservation laws are widely considered as one of the difficulties in numerical simulation. A numerical method is proposed for solving these partial differential equations with discontinuities in the solution. The method is able to track these sharp discontinuities or interfaces while still fully maintain the conservation property. The motion of the front is obtained by solving a Riemann problem based on the state values at its both sides which are reconstructed by using weighted essentially non oscillatory (WENO) scheme. The propagation of the front is coupled with the evaluation of "dynamic" numerical fluxes. Some numerical tests in 1D and preliminary results in 2D are presented.
Resumo:
This paper describes a novel numerical algorithm for simulating the evolution of fine-scale conservative fields in layer-wise two-dimensional flows, the most important examples of which are the earth's atmosphere and oceans. the algorithm combines two radically different algorithms, one Lagrangian and the other Eulerian, to achieve an unexpected gain in computational efficiency. The algorithm is demonstrated for multi-layer quasi-geostrophic flow, and results are presented for a simulation of a tilted stratospheric polar vortex and of nearly-inviscid quasi-geostrophic turbulence. the turbulence results contradict previous arguments and simulation results that have suggested an ultimate two-dimensional, vertically-coherent character of the flow. Ongoing extensions of the algorithm to the generally ageostrophic flows characteristic of planetary fluid dynamics are outlined.
Resumo:
Numerical results are presented and compared for three conservative upwind difference schemes for the Euler equations when applied to two standard test problems. This includes consideration of the effect of treating part of the flux balance as a source, and a comparison of different averaging of the flow variables. Two of the schemes are also shown to be equivalent in their implementation, while being different in construction and having different approximate Jacobians. (C) 2006 Elsevier Ltd. All rights reserved.