Moving mesh methods for solving parabolic partial differential equations

In this thesis, we introduce and assess a new adaptive method for solving non-linear parabolic partial differential equations with fixed or moving boundaries, using a moving mesh with continuous finite elements. The evolution of the mesh within the interior of the spatial domain is based upon conserving the distribution of a chosen monitor function across the domain throughout time, where the initial distribution is based upon the given initial data. For the moving boundary cases, the mesh movement at the boundary is governed by a second monitor function. The method is applied with different monitor functions, to the semilinear heat equation in one space dimension, and the porous medium equation in one and two space dimensions. The effects of optimising initial data for chosen monitors will be considered - in these cases, maintaining the initial distribution amounts to equidistribution. A quantification of the effects of a mesh moving away from an equidistribution are considered here, also the effects of tangling, and then untangling a mesh and restarting

Spectral analysis: theory and numerical results

This paper explains how spectral theory characterises an operator, acting on a Banach or Hilbert space, and so helps to solve an equation of that operator, or characterise its solution. Sobolev spaces are discussed, and then Spectral theory is applied to a Laplace operator with Dirichlet boundary conditions, and the eigenvalues characterised. An adapted version of the Rayleigh–Ritz Approximation technique is then used to estimate the eigenvalues

The Effect of EHR-Integrated Patient Reported Outcomes on Satisfaction with Chronic Pain Care

Objective Given its complexity, chronic noncancer pain presents an opportunity to use health information technology (IT) to improve care experiences. The objective of this study was to assess whether integrating patient-reported outcomes (PRO) data in an electronic health record (EHR) affects providers and patient satisfaction with chronic noncancer pain care. Study Design We conducted a pragmatic cluster randomized trial involving four family medicine clinics. Methods We enrolled primary care providers (PCPs) and their patients with chronic noncancer pain. In the first seven months (education phase), PCPs in intervention practices received education on how to use PROs for pain care. In the second seven months (PRO phase), patients in intervention practices reported pain-related outcomes upon arrival at their visits. PROs were immediately reported to PCPs through the EHR. Control group PCPs provided usual care. We compared intervention and control practices in terms of provider and patient satisfaction with care. Results During the education phase, patients’ mean ratings of their visits did not differ between control and intervention (9.33 vs. 9.08, p=0.20). During the PRO phase, patients’ mean ratings did not differ between control and intervention (9.28 vs 9.01, p=0.20). Similarly, there were no differences between the intervention and control groups in terms of provider satisfaction. Conclusion Delivering EHR-integrated PROs did not consistently improve patient or provider satisfaction. Positively, we found no evidence that the PRO tools negatively affected satisfaction. Future studies and technological innovations are needed to translate point-of-care health IT tools to improvements in patient and provider experiences

Comparative effectiveness of dual-action versus single-action antidepressants for the treatment of depression in people living with HIV/AIDS

Background Depression is the most common psychiatric comorbidity among people living with HIV/AIDS (PLWHA). Little is known about the comparative effectiveness between different types of antidepressants used to treat depression in this population. We compared the effectiveness of dual-action and single-action antidepressants in PLWHA for achieving remission from depression. Methods We used data from the Centers for AIDS Research Network of Integrated Clinic Systems to identify 1175 new user dual-action or single-action antidepressant treatment episodes occurring from 2005 to 2014 for PLWHA diagnosed with depression. The primary outcome was remission from depression defined as a Patient Health Questionnaire-9 (PHQ-9) score <5. Mean difference in PHQ-9 depressive symptom severity was a secondary outcome. The main approach was an intent-to-treat (ITT) evaluation complemented with a per protocol (PP) sensitivity analysis. Generalized linear models were fitted to estimate treatment effects. Results In ITT analysis, 32% of the episodes ended in remission for both dual-action and single-action antidepressants. The odds ratio (OR) of remission was 1.02 (95%CI=0.63,1.67). In PP analysis, 40% of dual-action episodes ended in remission compared to 32% in single-action episodes. Dual-action episodes had 1.33 times the odds of remission (95%CI=0.55,3.21), however the result was not statistically significant. Non-significant differences were also observed for depressive symptom severity. Limitations Missing data was common but was addressed with inverse probability weights. Conclusions Results suggest that single-action and dual-action antidepressants are equally effective in PLWHA. Remission was uncommon highlighting the need to identify health service delivery strategies that aid HIV providers in achieving full remission of their patients’ depression

Evaluation of the Effect of Hydrated Lime on the Scavenging of Feral Swine (\u3ci\u3eSus Scrofa\u3c/i\u3e) Carcasses and Implications for Managing Carcass-Based Transmission of African Swine Fever Virus

African swine fever (ASF) is a devastating hemorrhagic disease marked by extensive morbidity and mortality in infected swine. The recent global movement of African swine fever virus (ASFV) in domestic and wild swine (Sus scrofa) populations has initiated preparedness and response planning activities within many ASF-free countries. Within the US, feral swine are of utmost concern because they are susceptible to infection, are wide-spread, and are known to interact with domestic swine populations. African swine fever virus is particularly hardy and can remain viable in contaminated carcasses for weeks to months; therefore, carcass-based transmission plays an important role in the epidemiology of ASF. Proper disposal of ASF-infected carcasses has been demonstrated to be paramount to curbing an ASF outbreak in wild boar in Europe; preparedness efforts in the US anticipate carcass management being an essential component of control if an introduction were to occur. Due to environmental conditions, geographic features, or limited personnel, immediately removing every carcass from the landscape may not be viable. Hydrated lime converts to calcium carbonate, forming a sterile crust that may be used to minimize pathogen amplification. Any disturbance by scavenging animals to the sterile crust would nullify the effect of the hydrated lime; therefore, this pilot project aimed to evaluate the behavior of scavenging animals relative to hydrated lime-covered feral swine carcasses on the landscape. At two of the three study sites, hydrated limetreated carcasses were scavenged less frequently compared to the control carcasses. Additionally, the median time to scavenging was 1 d and 6 d for control versus hydrated lime-treated carcasses, respectively. While results of this study are preliminary, hydrated lime may be used to deter carcass disruption via scavenging in the event that the carcass cannot be immediately removed from the landscape

Aircraft accident report: NASA 712, Convair 990, N712NA, March Air Force Base, California, July 17, 1985, facts and analysis

On July 17, l985, at 1810 P.d.t., NASA 712, a Convair 990 aircraft, was destroyed by fire at March Air Force Base, California. The fire started during the rollout after the pilot rejected the takeoff on runway 32. The rejected takeoff was initiated during the takeoff roll because of blown tires on the right landing gear. During the rollout, fragments of either the blown tires or the wheel/brake assemblies penetrated a right-wing fuel tank forward of the right main landing gear. Leaking fuel ignited while the aircraft was rolling, and fire engulfed the right wing and the fuselage after the aircraft was stopped on the runway. The 4-man flightcrew and the 15 scientists and technicians seated in the cabin evacuated the aircraft without serious injury. The fire was not extinguished by crash/rescue efforts and the aircraft was destroyed

Novel patient-derived xenograft mouse model for pancreatic acinar cell carcinoma demonstrates single agent activity of oxaliplatin

Additional file 4: Figure S3. Integrated genomic viewer (IGV) of BRCA2 gene. IGV displays genomic data of the PA-018 PAAC PDTX model. Chromosome 13 (Chr 13) is shown and 5bp deletions are found after position 32907365 (c.1755_1759del5), this region resides on exon 10 of BRCA2. The bottom of the image shows the nucleotides and amino acids that correspond to the reference sequence of the BRCA2 gene and protein