Patient and provider perceptions of a peer-delivered intervention ('Khanya') to improve anti-retroviral adherence and substance use in South Africa: a mixed methods analysis

BACKGROUND: Despite a high prevalence of problematic substance use among people living with HIV in South Africa, there remains limited access to substance use services within the HIV care system. To address this gap, our team previously developed and adapted a six-session, peer-delivered problem-solving and behavioral activation-based intervention (Khanya) to improve HIV medication adherence and reduce substance use in Cape Town. This study evaluated patient and provider perspectives on the intervention to inform implementation and future adaptation. METHODS: Following intervention completion, we conducted semi-structured individual interviews with patients (n = 23) and providers (n = 9) to understand perspectives on the feasibility, acceptability, and appropriateness of Khanya and its implementation by a peer. Patients also quantitatively ranked the usefulness of individual intervention components (problem solving for medication adherence 'Life-Steps', behavioral activation, mindfulness training, and relapse prevention) at post-treatment and six months follow-up, which we triangulated with qualitative feedback to examine convergence and divergence across methods. RESULTS: Patients and providers reported high overall acceptability, feasibility, and appropriateness of Khanya, although there were several feasibility challenges. Mindfulness and Life-Steps were identified as particularly acceptable, feasible, and appropriate components by patients across methods, whereas relapse prevention strategies were less salient. Behavioral activation results were less consistent across methods. CONCLUSIONS: Findings underscore the importance of examining patients' perspectives on specific intervention components within intervention packages. While mindfulness training and peer delivery models were positively perceived by consumers, they are rarely used within task-shared behavioral interventions in low- and middle-income countries

Habitable Zones in the Universe

Habitability varies dramatically with location and time in the universe. This was recognized centuries ago, but it was only in the last few decades that astronomers began to systematize the study of habitability. The introduction of the concept of the habitable zone was key to progress in this area. The habitable zone concept was first applied to the space around a star, now called the Circumstellar Habitable Zone. Recently, other, vastly broader, habitable zones have been proposed. We review the historical development of the concept of habitable zones and the present state of the research. We also suggest ways to make progress on each of the habitable zones and to unify them into a single concept encompassing the entire universe.Comment: 71 pages, 3 figures, 1 table; to be published in Origins of Life and Evolution of Biospheres; table slightly revise

Bis(imino)pyrazine-Supported Iron Complexes: Ligand-Based Redox Chemistry, Dearomatization, and Reversible C-C Bond Formation

Iron complexes supported by novel pi-acidic bis-(imino)pyrazine ((PDI)-D-Pz) ligands can be functionalized at the nonligated nitrogen atom, and this has a marked effect on the redox properties of the resulting complexes. Dearomatization is observed in the presence of cobaltocene, which reversibly reduces the pyrazine core and not the imine functionality, as observed in the case of the pyridinediimine-ligated iron analogues. The resulting ligand-based radical is prone to dimerization through the formation of a long carbon-carbon bond, which can be subsequently cleaved under mild oxidative conditions

Field trials of subsurface chaotic advection: Stirred reactive reservoirs

Chaotic advection refers to the mixing of fluid elements which arise from repeated stretching and folding of fluid parcels [7,8]. Chaotic advection can be generated by time-dependent Darcy flows and has the potential to enhance mixing under laminar conditions in subsurface reservoirs or other porous media [3,4,10]. Enhanced mixing has many possible applications in environmental science and engineering. Remediation of contaminated aquifers is particularly relevant where mixing between the injected reagent and contaminant is a critical step. To assess whether chaos can be invoked at scale in a natural porous medium, a field trial is being designed in the sandpit area at the University of Waterloo Groundwater Research Facility at CFB Borden located near Alliston, ON, Canada, where we propose to use a transient reoriented dipole flow for subsurface stirring. This paper describes the design criteria associated with this phase of the field trial and presents preliminary modelling results for the determination of key flow system parameters. The Borden aquifer was modelled using Visual MODFLOW® Flex, a 3-D software for groundwater flow and heat/contaminant transport. Assumptions included aquifer homogeneity and isotropic and confined flow. At this initial screening stage, focus was given to horizontal flow fields generated. Simulation results showed that after at least four periodic reorientations of dipoles spaced 1.50 m apart with a pumping rate and duration of 2.50 m3/d and 3 hours, respectively, there is significant crossing of flow paths in the Borden aquifer that indicates high potential for rapid mixing