Application of dimensional analysis and group theory to the solution of ordinary and partial differential equations Final report, 17 Jan. 1966 - 16 Jan. 1967

Dimensional analysis and group theory methods of solving ordinary and partial differential equation

Use of Green's functions in the numerical solution of two-point boundary value problems Final report, 1 Apr. 1970 - 31 Mar. 1971

Green function in solving linear and nonlinear second order ordinary differential equations including examples in finding rendezvous and periodic orbits of restricted three body syste

Solution of differential equations by application of transformation groups

Report applies transformation groups to the solution of systems of ordinary differential equations and partial differential equations. Lies theorem finds an integrating factor for appropriate invariance group or groups can be found and can be extended to partial differential equations

Application of group and transformation theory to the solution of ordinary and partial differential equations Final report, 17 Jan. 1967 - 16 Jan. 1968

Application of transformation groups to solution of partial differential equation

Application of group and transformation theory to the solution of ordinary and partial differential equations Final report

Lie transformation group for solution of partial differential equation

The Inter-Relationship Between Employment Status and Interpersonal Violence in Malawi: A Trauma Center Experience

Introduction: As a proportion of the overall population, sub-Saharan Africa (SSA) has the highest youth demographic, composing 60% of Africa’s unemployed. With the worsening economic crisis in low- and middle-income countries, unengaged youth are susceptible to gang violence and anti-government demonstrations, resulting in political instability. Methods: We performed a retrospective review of the Kamuzu Central Hospital Trauma Registry from 2008–2018. All adult patients (>14 years) injured by interpersonal violence (IPV) were included. Age was categorized as 15–24 (youth), 25–45, and >45 years. A bivariate analysis (IPV versus unintentional injury), and Poisson multivariable analysis were performed to identify factors increasing the risk of IPV. Results: During the study, 87,338 trauma patients presented; 30,532 (35.0%) were injured following IPV. Patients injured following IPV (28 years, IQR 23–34) were younger than those unintentionally injured (30 years, IQR 23–39, p 45 years (RR 1.72, 1.66–1.79), and those injured at night (RR 2.18, 95% CI 2.14–2.23) had increased the risk of being victims of IPV. Conclusion: In Malawi, there is an interrelationship between unemployment and IPV, particularly in the youth population. Given impending demographic realities, government and non-government organizations should prioritize youth employment to help defer political instability in vulnerable nation-states

Characteristics and outcomes in paediatric patients presenting with congenital colorectal diseases in sub-Saharan Africa

In sub-Saharan Africa, there is a high burden of paediatric surgical conditions and a paucity of data regarding outcomes of congenital colorectal anomalies. A retrospective, descriptive analysis utilizing the Kamuzu Central Hospital (Lilongwe, Malawi) paediatric acute care surgery database (age ≤ 18 years) over 44 months was performed. Of the 133 children presenting, 82 had Hirschsprung disease (HD) (2.4 ± 2.7 years) and 51 had anorectal malformations (ARM) (1.8 ± 2.4 years). Of the latter, 51.0% underwent surgery, mainly exploratory laparotomy (n = 15, 57.7%) and posterior sagittal anorectoplasty (n = 7, 26.9%). Of those with HD, 50.0% underwent operative intervention (77.3% boys), including exploratory laparotomy (n = 17, 41.5%) and definitive pull-through (n = 8, 19.5%). A dearth of expert paediatric surgeons and limited exposure to paediatric conditions in general surgeons limits definitive surgery. An emphasis on paediatric surgical training and improvement of referral networks for definitive therapy will improve patient outcomes

Community Impacts of Prosopis Juliflora Invasion: Biogeographic and Congeneric Comparisons

We coordinated biogeographical comparisons of the impacts of an exotic invasive tree in its native and non-native ranges with a congeneric comparison in the non-native range. Prosopis juliflora is taxonomically complicated and with P. pallida forms the P. juliflora complex. Thus we sampled P. juliflora in its native Venezuela, and also located two field sites in Peru, the native range of Prosopis pallida. Canopies of Prosopis juliflora, a native of the New World but an invader in many other regions, had facilitative effects on the diversity of other species in its native Venezuela, and P. pallida had both negative and positive effects depending on the year, (overall neutral effects) in its native Peru. However, in India and Hawaii, USA, where P. juliflora is an aggressive invader, canopy effects were consistently and strongly negative on species richness. Prosopis cineraria, a native to India, had much weaker effects on species richness in India than P. juliflora. We carried out multiple congeneric comparisons between P. juliflora and P. cineraria, and found that soil from the rhizosphere of P. juliflora had higher extractable phosphorus, soluble salts and total phenolics than P. cineraria rhizosphere soils. Experimentally applied P. juliflora litter caused far greater mortality of native Indian species than litter from P. cineraria. Prosopis juliflora leaf leachate had neutral to negative effects on root growth of three common crop species of north-west India whereas P. cineraria leaf leachate had positive effects. Prosopis juliflora leaf leachate also had higher concentrations of total phenolics and L-tryptophan than P. cineraria, suggesting a potential allelopathic mechanism for the congeneric differences. Our results also suggest the possibility of regional evolutionary trajectories among competitors and that recent mixing of species from different trajectories has the potential to disrupt evolved interactions among native species

The Effect of a Surgery Residency Program and Enhanced Educational Activities on Trauma Mortality in Sub-Saharan Africa

Introduction: To address the need for more surgical providers in low-resource settings, a collaboration to create a surgical residency-training program for local Malawian physicians was established in 2009. This study sought to describe the short-term independent effect of a surgical residency program on trauma mortality at a tertiary trauma center in sub-Saharan Africa. Methods: We conducted a retrospective analysis of all patients recorded in the trauma surveillance registry of Kamuzu Central Hospital in Lilongwe, Malawi, from 2009 (three residents) through 2014 (11 residents). Log-binominal regression modeling was used to compare the risk ratio of death compared to the referent year of 2009, when the program was started, after adjusting for relevant covariates. Primary injury type was used as a surrogate for injury severity. Results: In total, 82,534 patients were recorded into the KCH Trauma Registry during the study period. Mean age was 23.1 years (SD 15.7) with a male preponderance (72.1%). Trauma patient volume increased from 8725 patients in 2009 to 15,998 patients in 2014. Each year had a significantly decreased risk of death compared to 2009 when adjusted for primary injury type, age, and gender, with an adjusted risk ratio of 0.73 (95% CI 0.58, 0.90) in 2010 and 0.52 (95% CI 0.43, 0.62) in 2014. Conclusion: The global burden of surgical diseases cannot be attenuated in the presence of an inadequate surgical workforce. After institution of a surgery residency program, adjusted injury-associated mortality decreased each year despite substantial increases in trauma patient volume. In low-resource settings, establishment of a surgical residency program significantly improves trauma-associated outcomes