1,317 research outputs found
USING BOTH SOCIOLOGICAL AND ECONOMIC INCENTIVES TO REDUCE MORAL HAZARD
Economists tend to focus on monetary incentives. In the model developed here, both sociological and economic incentives are used to diminish the apparent moral hazard problem existing in commodity grading. Training that promotes graders' response to sociological incentives is shown to increase expected benefits. The model suggests that this training be increased up to the point where the marginal benefit due to training equals its marginal cost. It may be more economical to influence the grader's behavior by creating cognitive dissonance through training and rules rather than by using economic incentives alone.Marketing,
Using Both Sociological and Economic Incentives to Reduce Moral Hazard
Economists tend to focus on monetary incentives. In the model developed here, both sociological and economic incentives are used to diminish the apparent moral hazard problem existing in commodity grading. Training that promotes graders' response to sociological incentives is shown to increase expected benefits. The model suggests this training be increased up to the point where the marginal benefit due to training equals its marginal cost. It may be more economical to influence the grader's behavior by creating cognitive dissonance through training and rules rather than by using economic incentives alone.grading, incentives, moral hazard, norms, social sanctions, Institutional and Behavioral Economics,
Iatrogenic Spinal Cord Injury Resulting From Cervical Spine Surgery.
STUDY DESIGN: Retrospective cohort study of prospectively collected data.
OBJECTIVE: To examine the incidence of iatrogenic spinal cord injury following elective cervical spine surgery.
METHODS: A retrospective multicenter case series study involving 21 high-volume surgical centers from the AOSpine North America Clinical Research Network was conducted. Medical records for 17 625 patients who received cervical spine surgery (levels from C2 to C7) between January 1, 2005, and December 31, 2011, were reviewed to identify occurrence of iatrogenic spinal cord injury.
RESULTS: In total, 3 cases of iatrogenic spinal cord injury following cervical spine surgery were identified. Institutional incidence rates ranged from 0.0% to 0.24%. Of the 3 patients with quadriplegia, one underwent anterior-only surgery with 2-level cervical corpectomy, one underwent anterior surgery with corpectomy in addition to posterior surgery, and one underwent posterior decompression and fusion surgery alone. One patient had complete neurologic recovery, one partially recovered, and one did not recover motor function.
CONCLUSION: Iatrogenic spinal cord injury following cervical spine surgery is a rare and devastating adverse event. No standard protocol exists that can guarantee prevention of this complication, and there is a lack of consensus regarding evaluation and treatment when it does occur. Emergent imaging with magnetic resonance imaging or computed tomography myelography to evaluate for compressive etiology or malpositioned instrumentation and avoidance of hypotension should be performed in cases of intraoperative and postoperative spinal cord injury
Misplaced Cervical Screws Requiring Reoperation.
STUDY DESIGN: A multicenter, retrospective case series.
OBJECTIVE: In the past several years, screw fixation of the cervical spine has become commonplace. For the most part, this is a safe, low-risk procedure. While rare, screw backout or misplaced screws can lead to morbidity and increased costs. We report our experiences with this uncommon complication.
METHODS: A multicenter, retrospective case series was undertaken at 23 institutions in the United States. Patients were included who underwent cervical spine surgery from January 1, 2005, to December 31, 2011, and had misplacement of screws requiring reoperation. Institutional review board approval was obtained at all participating institutions, and detailed records were sent to a central data center.
RESULTS: A total of 12 903 patients met the inclusion criteria and were analyzed. There were 11 instances of screw backout requiring reoperation, for an incidence of 0.085%. There were 7 posterior procedures. Importantly, there were no changes in the health-related quality-of-life metrics due to this complication. There were no new neurologic deficits; a patient most often presented with pain, and misplacement was diagnosed on plain X-ray or computed tomography scan. The most common location for screw backout was C6 (36%).
CONCLUSIONS: This study represents the largest series to tabulate the incidence of misplacement of screws following cervical spine surgery, which led to revision procedures. The data suggest this is a rare event, despite the widespread use of cervical fixation. Patients suffering this complication can require revision, but do not usually suffer neurologic sequelae. These patients have increased cost of care. Meticulous technique and thorough knowledge of the relevant anatomy are the best means of preventing this complication
Small grain variety report 1981
Cover title. "September 1981." Microfilm. Stoughton, Mass. : Graphic Microfilm, Inc., 1977. 1 reel ; 35 mm. Shelved with: State agricultural papers
Topological Defects and Interactions in Nematic Emulsions
Inverse nematic emulsions in which surfactant-coated water droplets are
dispersed in a nematic host fluid have distinctive properties that set them
apart from dispersions of two isotropic fluids or of nematic droplets in an
isotropic fluid. We present a comprehensive theoretical study of the
distortions produced in the nematic host by the dispersed droplets and of
solvent mediated dipolar interactions between droplets that lead to their
experimentally observed chaining. A single droplet in a nematic host acts like
a macroscopic hedgehog defect. Global boundary conditions force the nucleation
of compensating topological defects in the nematic host. Using variational
techniques, we show that in the lowest energy configuration, a single water
droplet draws a single hedgehog out of the nematic host to form a tightly bound
dipole. Configurations in which the water droplet is encircled by a
disclination ring have higher energy. The droplet-dipole induces distortions in
the nematic host that lead to an effective dipole-dipole interaction between
droplets and hence to chaining.Comment: 17 double column pages prepared by RevTex, 15 eps figures included in
text, 2 gif figures for Fig. 1
Small Grain Variety Report 1979
Caption title. "August 1979." Microfilm. Stoughton, Mass. : Graphic Microfilm, Inc., 1977. 1 reel ; 35 mm. Shelved with: State agricultural papers
Reacting plume inversion on urban geometries through gradient based design methodologies
An increased focus on domestic security in recent years has brought attention to several important application areas where computational fluid dynamics (CFD) has the ability to make a significant impact. In particular, disaster mitigation and post-event forensic activities are of interest. This work investigates a procedure built on gradient based design methods to allow for the solution of the so-called inverse chemistry problem in urban environments. The inverse chemistry problem consists of computing a release location based on the sensing of chemical byproducts of the release and the ability to compute an accurate flow field on the geometry of interest. In this study, Washington DC is simulated under conditions of a hazardous plume. A CFD solver is implemented which allows for the solution of the preconditioned finite-rate Navier-Stokes equations as well as the in situ computation of design gradients
A hybrid method for flows in local chemical equilibrium and nonequilibrium
The primary objective of this work is to develop a more efficient chemically active compressible Euler equation solver. Currently, a choice between the physical accuracy of a finite-rate solver or the computational efficiency of an equilibrium flow solver must be made. The number of species modeled continues to increase with available computational resources. A method of further leveraging the increase in computational power is desired. The hybrid chemistry scheme proposed here attempts to maintain the accuracy of finite-rate schemes while retaining some of the cost savings associated with equilibrium chemistry solvers. The method given uses a full finite-rate flux in regions where chemistry is slow compared to the advection rate and an equilibrium chemistry scheme in regions where the chemistry outpaces the fluid transport. Control volume switching is based on a locally defined Damk ̈ohler number. This method could be extremely useful for full reaction path modeling or the tracking of a very large number of species. The cost of symmetric Gauss-Seidel iterations grows like the number of species plus four, quantity squared. Thus, eliminating the increased cost of solving for a large number of unknowns in regions where it is unjustified can be very useful. Tenasi, a University of Tennessee SimCenter research code, is used as a base for the new solver. The hybrid method is implemented and tested with an explicit solution technique in one dimension. In combination with a five species air chemistry model, a high-temperature shock tube is used as a verification test case. Results are compared with those from pure equilibrium, full finite-rate, perfect gas Euler, and exact perfect gas Riemann solvers. Timings are also given, suggesting the cost savings that would be possible should the hybrid method be extended using implicit algorithms
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