Impact of antiretroviral therapy on adult HIV prevalence in a low-income rural setting in Uganda: a longitudinal population-based study.

OBJECTIVE: To estimate the contribution to HIV prevalence of lives saved due to the introduction of antiretroviral therapy (ART) in rural Uganda in 2004. DESIGN: Open population-based cohort study. METHODS: An open general population cohort with annual demographic and HIV serostatus data is used to estimate annual HIV prevalence, HIV incidence, and mortality from 2000 to 2010. We calculated standardized mortality rates among HIV-positive adults and the expected number of deaths in the cohort if ART had not been available during 2004-2010, based on the average mortality rate in the 4 years (2000-2003) before ART introduction. RESULTS: During 2004-2010, the estimated prevalence increased by 29% from 6.9% to 8.9%. HIV incidence was 5.6 cases per 1000 person-years in 2004, falling to 3.9 cases per 1000 person-years in 2006, and slightly rising to 5.1 in 2010. There was an increase of 182 in the number of HIV-positive participants during that period, cumulatively 228 lives were saved due to ART. Expected lives saved due to ART accounted for an increasing proportion of the estimated HIV prevalence from 4.0% in 2004 to 29.4% in 2010. CONCLUSIONS: Expected lives saved due to ART largely accounted for the increased estimated HIV prevalence from 2004 to 2010. Because HIV prevalence survey results are important for planning, programming, and policy, their interpretation requires consideration of the increasing impact of ART in decreasing mortality

Collaboration - It\u27s a Good Thing!: A multi-faceted role analysis in graduate student education as faculty-in-training .

“Collaboration appears to play a unique role in science and science education today,” and serves as a rite of passage for new graduate students that indicates acceptance and achievement in research (Hara et. al. 2003). Collaboration is a crucial skill for faculty and students, helping advance knowledge and exploit the results of research effectively. In this project a group of six new Ph.D. students worked together with one faculty member and one post-doctoral researcher to develop a new course in Environmental Information Science. This poster is a report on the successes and barriers to collaboration encountered during the course of the project

Comparison of retention in observational cohorts and nested simulated HIV vaccine efficacy trials in the key populations in Uganda.

BACKGROUND: Outcomes in observational studies may not best estimate those expected in the HIV vaccine efficacy trials. We compared retention in Simulated HIV Vaccine Efficacy Trials (SiVETs) and observational cohorts drawn from two key populations in Uganda. METHODS: Two SiVETs were nested within two observational cohorts, one in Fisherfolk (FF) and another one in Female Sex Workers (FSW). Adult participants in each observational cohort were screened for enrolment into SiVETs. Those screened-out or not screened continued participation in the observational (non-SiVET) cohorts. SiVET participants were administered a licensed hepatitis B vaccine in a schedule that mimicked an actual HIV vaccine efficacy trial. Both cohorts were followed for 12 months and retention was assessed through dropout, defined as lost to follow up, being uncontactable, refusal to continue or missing the last study clinic visit. Dropout rates were compared using Poisson models giving rate ratios and 95% confidence intervals (95%CI). RESULTS: Out of 1525 participants (565 FF and 960 FSW), 572 (38%) were enrolled into SiVETs (282-FF and 290-FSW), and 953 (62%) remained in the non-SiVET cohorts. Overall, 326 (101 SiVET, 225 non-SiVET) dropped out in 1260 Person Years of Observation (PYO), a dropout rate of 25.9 /100 PYO (95%CI: 23.2-28.8); fewer dropped out in the SiVET cohorts (18.4, 95% CI: 15.1-22.4) than in the non-SiVET cohorts (31.6, 95% CI: 27.8-36.1), rate ratio (RR) =0.58, 95% CI: 0.46-0.73. In all cohorts, the dropout was more marked in FSW than in FF population. Duration lived in community was associated with dropout in both SiVETs and religion in both non-SiVET cohorts. CONCLUSION: The rate of dropout was lower in SiVET compared to non-SiVET cohort. Though the difference in dropout between SiVET and non-SiVET was generally similar, the actual dropout rates were higher in the FSW population. Conduct of SiVETs in these key populations could mean that designing HIV Vaccine Efficacy Trials will benefit from lower dropout rate shown in SiVET than non-SiVET observational cohort

EMI Associated with Inter-Board Connection for Module-on-Backplane and Stacked-card Configurations

EMI associated with inter-board connection was studied through common-mode current measurements and FDTD modeling for stacked-card and module-on-backplane configurations. Three types of connections were investigated experimentally including an open pin field connection, an ideal semi-rigid coaxial cable connection, and a production connector. Both microstrip and stripline signal routing on the PCB were investigated. The results indicated signal routing on the PCBs or the inter-board connection can dominate the EMI process. Several cases of connector geometries were studied using FDTD modeling and good agreement was achieved between the measured and FDTD results

Experimental and FDTD Study of the EMI Performance of an Open-Pin-Field Connector for Modules-on-Backplanes

Experimental measurements and numerical modeling were used to study the EMI performance of a module-on-backplane connector for various configurations of signal-return pin-outs. A commercially available open-pin-field connector was used in these results to connect between the mother-board and the daughter-card. The experimental techniques, based on measuring |S21|, included both common-mode current measurements and monopole near-field probe measurements. The FDTD method was used to provide numerical support of the near-field measurements and generally agreed with the measured results for frequencies up to 3 GHz. The FDTD method was also used to investigate the relationship between the radiated EMI at 3 m and the connector pin-out configurations

Comparison of HIV Risk Behaviors Between Clinical Trials and Observational Cohorts in Uganda.

Many key populations have high-risk behaviors for HIV infection making them suitable for HIV vaccine efficacy trials. However, these behaviors may change when participants enroll into a trial. We used HIV simulated vaccine efficacy trials (SiVETs) nested within observational cohorts of fisherfolks and female sex workers in Uganda to evaluate this difference. We screened observational cohort participants for enrolment into SiVETs, until 572 were enrolled. Those not enrolled (n = 953) continued participation in the observational cohorts. We determined risk behaviors at baseline and at 1 year, assigned a numeric score to each behavior and defined composite score as the sum of reported behaviors. We compared changes in scores over 12 months. Both observational cohorts and SiVETs saw a significant decrease in score but greatest in the SiVETs. Investigators recruiting for trials from these populations should consider the likely effect of reduction in risk behaviors on incident HIV infection and trial statistical power

Effect of tuberculosis infection on mortality of HIV-infected patients in Northern Tanzania.

BACKGROUND: TB and HIV are public health problems, which have a synergistic effect to each other. Despite the decreasing burden of these two diseases they still make a significant contribution to mortality. Tanzania is among the 30 high TB and HIV burden countries. METHODS: Routine data over 6 years from people living with HIV (PLHIV) attending health facilities in three regions of Northern Tanzania were analyzed, showing mortality trends from 2012 to 2017 for HIV and HIV/TB subpopulations. Poisson regression with frailty model adjusting for clustering at health facility level was used to analyze the data to determine mortality rate ratios (RR) and 95% confidence intervals (95%CI). RESULTS: Among all PLHIV the overall mortality rate was 28.4 (95% CI 27.6-29.2) deaths per 1000 person-years. For PLHIV with no evidence of TB the mortality rates was 26.2 (95% CI 25.4-27.0) per 1000 person-years, and for those with HIV/TB co-infection 57.8 (95% CI 55.6-62.3) per 1000 person-years. After adjusting for age, sex, residence, WHO stage, and bodyweight, PLHIV with TB co-infection had 40% higher mortality than those without TB (RR 1.4; 95% CI 1.24-1.67). CONCLUSIONS: Over the 6-year period mortality rates for HIV/TB patients were consistently higher than for PLHIV who have no TB. More efforts should be directed into improving nutritional status among HIV patients, as it has destructive interaction with TB for mortality. This will improve patients' body weight and CD4 counts which are protective against mortality. Among PLHIV attention should be given to those who are in WHO HIV stage 3 or 4 and having TB co-infection

Preconditioning a mixed discontinuous finite element method for radiation diffusion

We propose a multilevel preconditioning strategy for the iterative solution of large sparse linear systems arising from a finite element discretization of the radiation diffusion equations. In particular, these equations are solved using a mixed finite element scheme in order to make the discretization discontinuous, which is imposed by the application in which the diffusion equation will be embedded. The essence of the preconditioner is to use a continuous finite element discretization of the original, elliptic diffusion equation for preconditioning the discontinuous equations. We have found that this preconditioner is very effective and makes the iterative solution of the discontinuous diffusion equations practical for large problems. This approach should be applicable to discontinuous discretizations of other elliptic equations. We show how our preconditioner is developed and applied to radiation diffusion problems on unstructured, tetrahedral meshes and show numerical results that illustrate its effectiveness. Published in 2004 by John Wiley & Sons, Ltd

Increasing trend of exclusive breastfeeding over 12 years period (2002-2014) among women in Moshi, Tanzania.

BACKGROUND: The World Health Organization has recommended that all infants under 6 months should be exclusively breastfed. An understanding of the trend of exclusive breastfeeding (EBF) over years and over smaller geographical areas is crucial to monitor the progress made in improving the proportions of infants' EBF. METHODS: Data on infant feeding practices on 2315 mother-infant pairs from 2002 to 2014 were extracted from cohorts of women who delivered in the Moshi Municipality. Descriptive statistics were used to establish the trend of EBF up to 1, 3 and 6 months across waves (2002/2004 = wave I, 2005/2012 = wave II and 2013/2014 = wave III), to relate EBF up to 6 months to wealth quintiles and to HIV status of mothers. RESULTS: The number of mothers in waves I, II and III were 1656 (71.5%), 256 (11.1%) and 403(17.4%) respectively. The percentages of EBF up to 6 months increased from 5.5, 13.7 to 16.9% from wave I to III. Overall, across the waves, the proportion of EBF up to 6 months among the mothers in the low wealth quintile was 4, 9 and 42%, and 7, 26 and 15% for the ones in the highest wealth quintile. The proportion of EBF up to 6 months has been increasing among HIV positive mothers while fluctuating among their counterparts across the waves. CONCLUSION: The proportion of EBF up to 6 months has been increasing in the Moshi municipality but is below the national average. While establishing trends of EBF at the national level is commendable, research to establish trends over smaller geographical areas is needed to provide a true picture that may otherwise be masked

Geometrically-compatible 3-D Monte Carlo and discrete-ordinates methods

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The purpose of this project was two-fold. The first purpose was to develop a deterministic discrete-ordinates neutral-particle transport scheme for unstructured tetrahedral spatial meshes, and implement it in a computer code. The second purpose was to modify the MCNP Monte Carlo radiation transport code to use adjoint solutions from the tetrahedral-mesh discrete-ordinates code to reduce the statistical variance of Monte Carlo solutions via a weight-window approach. The first task has resulted in a deterministic transport code that is much more efficient for modeling complex 3-D geometries than any previously existing deterministic code. The second task has resulted in a powerful new capability for dramatically reducing the cost of difficult 3-D Monte Carlo calculations