6,948 research outputs found
The Competitive Performance of Life Insurance Firms in the Retirement Asset Market
This paper summarizes the findings of the joint Wharton Financial Institutions Center and KPMG study of the retirement assets market and the role of life insurance companies within it. The study began with the following goals: Investigate how people save for retirement and whether this is adequate. Determine the primary products and institutions of the retirement asset market and observe how these have changed through time. Key findings: For most, asset accumulation is less than adequate for a comfortable retirement. The average worker exhibits little of the needed financial understanding to adequately plan for retirement. Upon retirement, households do not spend down their assets optimally. The retirement asset market is rapidly expanding. Products in retirement portfolios have shifted with time. The market share of mutual funds has exploded, mostly at the expense of depository institutions. Life insurance companies maintain a large, but slipping share.
Cross-sectional survey of Good Samaritan behaviour by physicians in North Carolina
ObjectiveTo assess the responses of physicians to providing emergency medical assistance outside of routine clinical care. We assessed the percentage who reported previous Good Samaritan behaviour, their responses to hypothetical situations, their comfort providing specific interventions and the most likely reason they would not intervene.SettingPhysicians residing in North Carolina.ParticipantsConvenience sample of 1000 licensed physicians.InterventionMailed survey.DesignCross-sectional study conducted May 2015 to September 2015.Main outcome and measuresWillingness of physicians to act as Good Samaritans as determined by the last opportunity to intervene in an out-of-office emergency.ResultsThe adjusted response rate was 26.1% (253/970 delivered). 4 out of 5 physicians reported previous opportunities to act as Good Samaritans. Approximately, 93% reported acting as a Good Samaritan during their last opportunity. There were no differences in this outcome between sexes, practice setting, specialty type or experience level. Doctors with greater perceived knowledge of Good Samaritan law were more likely to have intervened during a recent opportunity (p=0.02). The most commonly cited reason for potentially not intervening was that another health provider had taken charge.ConclusionsWe found the frequency of Good Samaritan behaviour among physicians to be much higher than reported in previous studies. Greater helping behaviour was exhibited by those who expressed more familiarity with Good Samaritan law. These findings suggest that physicians may respond to legal protections
Establishing gaze markers of perceptual load during multi-target visual search
Highly-automated technologies are increasingly incorporated into existing systems, for instance in advanced car models. Although highly automated modes permit non-driving activities (e.g. internet browsing), drivers are expected to reassume control upon a 'take over' signal from the automation. To assess a person's readiness for takeover, non-invasive eye tracking can indicate their attentive state based on properties of their gaze. Perceptual load is a well-established determinant of attention and perception, however, the effects of perceptual load on a person's ability to respond to a takeover signal and the related gaze indicators are not yet known. Here we examined how load-induced attentional state affects detection of a takeover-signal proxy, as well as the gaze properties that change with attentional state, in an ongoing task with no overt behaviour beyond eye movements (responding by lingering the gaze). Participants performed a multi-target visual search of either low perceptual load (shape targets) or high perceptual load (targets were two separate conjunctions of colour and shape), while also detecting occasional auditory tones (the proxy takeover signal). Across two experiments, we found that high perceptual load was associated with poorer search performance, slower detection of cross-modal stimuli, and longer fixation durations, while saccade amplitude did not consistently change with load. Using machine learning, we were able to predict the load condition from fixation duration alone. These results suggest monitoring fixation duration may be useful in the design of systems to track users' attentional states and predict impaired user responses to stimuli outside of the focus of attention
Explorations in the Stone-Campbell Traditions: Essays in Honor of Herman A. Norton
This important collection of essays honors Herman A. Norton (1921-2002), Dean of the Disciples Divinity House at Vanderbilt University from 1951 until his retirement in 1986. Topics from all three branches of the Stone-Campbell Movement are treated including early leaders like Barton Stone and Alexander Campbell, as well as later studies after the Civil War and into the early 1940s.https://digitalcommons.acu.edu/acu_library_books/1013/thumbnail.jp
Bioresorbable Polylactide Interbody Implants in an Ovine Anterior Cervical Discectomy and Fusion Model: Three-Year Results
Study Design.
In vivo study of anterior discectomy and fusion using a bioresorbable 70:30 poly(l-lactide-co-d,l-lactide) interbody implant in an ovine model.
Objective.
To evaluate the efficacy of the polylactide implant to function as an interbody fusion device, and to assess the tissue reaction to the material during the resorption process.
Summary of Background Data.
The use of polylactide as a cervical interbody implant has several potential advantages when compared with traditional materials. Having an elastic modulus very similar to bone minimizes the potential for stress shielding, and as the material resorbs additional loading is transferred to the developing fusion mass. Although preclinical and clinical studies have demonstrated the suitability of polylactide implants for lumbar interbody fusion, detailed information on cervical anterior cervical discectomy and fusion (ACDF) with polylactide devices is desirable.
Methods.
Single level ACDF was performed in 8 skeletally mature ewes. Bioresorbable 70:30 poly (l-lactide-co-d,l-lactide) interbody implants packed with autograft were used with single-level metallic plates. Radiographs were made every 3 months up to 1 year, and yearly thereafter. The animals were killed at 6 months (3 animals), 12 months (3 animals), and 36 months (2 animals). In addition to the serial plain radiographs, the specimens were evaluated by nondestructive biomechanical testing and undecalcified histologic analysis.
Results.
The bioresorbable polylactide implants were effective in achieving interbody fusion. The 6-month animals appeared fused radiographically and biomechanically, whereas histologic sections demonstrated partial fusion (in 3 of 3 animals). Radiographic fusion was confirmed histologically and biomechanically at 12 months (3 of 3 animals) and 36 months (2 of 2 animals). A mild chronic inflammatory response to the resorbing polylactide implant was observed at both 6 months and 12 months. At 36 months, the operative levels were solidly fused and the implants were completely resorbed. No adverse tissue response was observed in any animal at any time period.
Conclusion.
Interbody fusion was achieved using bioresorbable polylactide implants, with no evidence of implant collapse, extrusion, or adverse tissue response to the material. The use of polylactide as a cervical interbody device appears both safe and effective based on these ACDF animal model results
Unravelling referral paths relating to the dental care of children: a study in Liverpool.
ObjectiveTo describe primary care referral networks relating to children's dental care and the main influences on referral decisions taken by dentists working in a primary care setting.DesignA postal questionnaire to all 130 general dental practitioners (GDPs) in contract with Primary Care Trusts (PCTs), and 24 Community Dental Service (CDS) dentists in Liverpool.Outcome measuresCharacteristics of patient groups and factors influencing the choice of referral pathway of children referred from primary dental care.ResultsThere were good responses rates (110 [85%] GDPs and 22 [92%] CDS dentists). The two main reasons why GDPs referred children to hospitals were (a) for treatment under general anaesthetic (GA) or relative analgesia (RA) and (b) for restorative care of dentally anxious children. GDPs also referred anxious children requiring simple restorative care and/or RA to the CDS. Only eight GDPs (7%) cited a lack of experience as a reason for referral of dentally anxious children for simple restorative care, compared to 53 (48%) who cited a lack of RA facilities, and 25 (23%) who cited financial considerations.ConclusionsGDPs refer children to both hospital services and the CDS, and identify a lack of RA facilities and economic pressures as key reasons for referral
DG-IMEX Method for a Two-Moment Model for Radiation Transport in the Limit
We consider particle systems described by moments of a phase-space density
and propose a realizability-preserving numerical method to evolve a spectral
two-moment model for particles interacting with a background fluid moving with
nonrelativistic velocities. The system of nonlinear moment equations, with
special relativistic corrections to , expresses a balance
between phase-space advection and collisions and includes velocity-dependent
terms that account for spatial advection, Doppler shift, and angular
aberration. This model is closely related to the one promoted by Lowrie et al.
(2001; JQSRT, 69, 291-304) and similar to models currently used to study
transport phenomena in large-scale simulations of astrophysical environments.
The method is designed to preserve moment realizability, which guarantees that
the moments correspond to a nonnegative phase-space density. The
realizability-preserving scheme consists of the following key components: (i) a
strong stability-preserving implicit-explicit (IMEX) time-integration method;
(ii) a discontinuous Galerkin (DG) phase-space discretization with carefully
constructed numerical fluxes; (iii) a realizability-preserving implicit
collision update; and (iv) a realizability-enforcing limiter. In time
integration, nonlinearity of the moment model necessitates solution of
nonlinear equations, which we formulate as fixed-point problems and solve with
tailored iterative solvers that preserve moment realizability with guaranteed
convergence. We also analyze the simultaneous Eulerian-frame number and energy
conservation properties of the semi-discrete DG scheme and propose an "energy
limiter" that promotes Eulerian-frame energy conservation. Through numerical
experiments, we demonstrate the accuracy and robustness of this DG-IMEX method
and investigate its Eulerian-frame energy conservation properties
Diffusion MR Characteristics Following Concurrent Radiochemotherapy Predicts Progression-Free and Overall Survival in Newly Diagnosed Glioblastoma.
The standard of care for newly diagnosed glioblastoma (GBM) is surgery, then radiotherapy (RT) with concurrent temozolomide (TMZ), followed by adjuvant TMZ. We hypothesized patients with low diffusivity measured using apparent diffusion coefficient (ADC) histogram analysis evaluated after RT+TMZ, prior to adjuvant TMZ, would have a significantly shorter progression-free (PFS) and overall survival (OS). To test this hypothesis we evaluated 120 patients with newly diagnosed GBM receiving RT+TMZ followed by adjuvant TMZ. MRI was performed after completion of RT+TMZ, prior to initiation of adjuvant TMZ. A double Gaussian mixed model was used to describe the ADC histograms within the enhancing tumor, where ADCL and ADCH were defined as the mean ADC value of the lower and higher Gaussian distribution, respectively. An ADCL value of 1.0 um2/ms and ADCH value of 1.6 um2/ms were used to stratify patients into high and low risk categories. Results suggest patients with low ADCL had significantly shorter PFS (Cox Hazard Ratio = 0.12, P = 0.0006). OS was significantly shorter with low ADCL tumors, showing a median OS of 407 vs. 644 days (Cox Hazard Ratio = 0.31, P = 0.047). ADCH was not predictive of PFS or OS when accounting for age and ADCL. In summary, newly diagnosed glioblastoma patients with low ADCL after completion of RT+TMZ are likely to progress and die earlier than patients with higher ADCL. Results suggest ADC histogram analysis may be useful for patient risk stratification following completion of RT+TMZ
Two- and three-dimensional simulations of core-collapse supernovae with CHIMERA
Ascertaining the core-collapse supernova mechanism is a complex, and yet
unsolved, problem dependent on the interaction of general relativity,
hydrodynamics, neutrino transport, neutrino-matter interactions, and nuclear
equations of state and reaction kinetics. Ab initio modeling of core-collapse
supernovae and their nucleosynthetic outcomes requires care in the coupling and
approximations of the physical components. We have built our multi-physics
CHIMERA code for supernova modeling in 1-, 2-, and 3-D, using ray-by-ray
neutrino transport, approximate general relativity, and detailed neutrino and
nuclear physics. We discuss some early results from our current series of
exploding 2D simulations and our work to perform computationally tractable
simulations in 3D using the "Yin-Yang" grid.Comment: Proceedings of the 12th Symposium on Nuclei in the Cosmos. 5-12
August 2012. Cairns, Australia. Published online at
http://pos.sissa.it/archive/conferences/146/208/NIC%20XII_208.pdf Corrected
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