Differences in antiretroviral scale up in three South African provinces: the role of implementation management

BACKGROUND: South Africa's antiretroviral programme is governed by defined national plans, establishing treatment targets and providing funding through ring-fenced conditional grants. However, in terms of the country's quasi-federal constitution, provincial governments bear the main responsibility for provision of health care, and have a certain amount of autonomy and therefore choice in the way their HIV/AIDS programmes are implemented. METHODS: The paper is a comparative case study of the early management of ART scale up in three South African provincial governments--Western Cape, Gauteng and Free State--focusing on both operational and strategic dimensions. Drawing on surveys of models of ART care and analyses of the policy process conducted in the three provinces between 2005 and 2007, as well as a considerable body of grey and indexed literature on ART scale up in South Africa, it draws links between implementation processes and variations in provincial ART coverage (low, medium and high) achieved in the three provinces. RESULTS: While they adopted similar chronic disease care approaches, the provinces differed with respect to political and managerial leadership of the programme, programme design, the balance between central standardisation and local flexibility, the effectiveness of monitoring and evaluation systems, and the nature and extent of external support and programme partnerships. CONCLUSIONS: This case study points to the importance of sub-national programme processes and the influence of factors other than financing or human resource capacity, in understanding intervention scale up

Solubility dependence of peracylated d-glucopyranoses in supercritical carbon dioxide on the structure of their acyl moieties

Identification of chemical groups that enhance solubility of hydrocarbon-based surfactants and polymers in CO2 is of current interest in expanding applications of this 'green solvent'. In particular, the acetyl moiety is believed to solvate effectively in CO2 through a Lewis acid-base interaction between the carbonyl oxygen and CO2 carbon and this is further enhanced by specific weak H-bonding interaction of the α-hydrogens with the CO2 oxygen. In this communication we investigate the influence of this weak secondary interaction further by measurement of CO2 solubility of a range of β-d-glucopyranose pentaalkanoates containing as the acyl functionality acetyl, propionyl, butyryl, isobutyryl and trimethylacetyl (pivaloyl) groups. The results show that progressive replacement of the α-hydrogens of the acetyl by methyl results initially in a remarkable drop in solubility but surprisingly this is regained in the trimethylacetyl derivative that demonstrates a similarly high solubility to that of the acetyl compound

Measurement of inter-particle forces from the osmotic pressure of partially frozen dispersions

When an oil-continuous dispersion is frozen two microdomains are formed: one, the pure oil solvent which is selectively solidified (I), the other, a concentrated 'liquid' dispersion of particles in oil (II). These two domains are intimately mixed within the frozen colloid and exist in a state of equilibrium determined by the system pressure and temperature. The position of equilibrium controls the proportion of the solvent which is solidified, and thereby the concentration of particles within the fluid microdomains (II). Combined with SANS measurements, to determine the inter-particle separation in these microdomains, an analysis based on osmotic pressure provides a measure of the inter-particle repulsion forces presented by the surfactant layers

Effects of solidification of the oil phase on the structure of colloidal dispersions in cyclohexane

The liquid-to-solid transition of the alkane-continuous phase of a dilute surfactant-stabilized particle or droplet dispersion can be induced in a reversible manner without destabilizing the colloid by pressure and/or temperature changes. The structural changes have been studied by small-angle neutron scattering (SANS) over a range of pressure (1-600 bar) and temperatures (3-20-degrees-C). The SANS results indicate that there are different levels of structure in the solidified system in which a solid alkane coexists with fluid cluster domains. The clusters show large-scale structural correlations of order 5-50 mum; within these clusters the particles are in close contact, so that under certain conditions, e.g. high pressure, the stabilizing surfactant layers of adjacent particles are interdigitated. The distance between particle centers, and therefore the degree of surfactant interdigitation, can be readily varied by the application of pressure. An interpretation of the SANS results is given in terms of the effects of temperature and pressure upon the osmotic pressure of the concentrated solution of particles/droplets. The analysis provides an estimate of the interparticle pair potential energy between adjacent particles in a cluster as a function of separation

Structure of Cobalt Aerosol-OT Reversed Micelles Studied by Sall-Angle Scattering Methods

The surfactant-cyclohexane-water ternary phase behaviour and reversed micelle and water-in-oil (w/o) micro-emulsion structure of the cobalt (II) derivative of the anionic amphiphile Aerosol-OT (AOT) [Co(water)6](AOT)2 have been studied by polarising microscopy, small-angle neutron and X-ray scattering (SANS, SAXS). The surfactant forms an H2 reversed hexagonal phase on swelling with up to 25 wt.% cyclohexane. At higher concentrations of oil the fluid L2 reversed micellar phase is present, and a w/o phase forms up to w = 25.0 (w = [water]/[AOT-]). For w > 25.0 at 25-degrees-C a Winsor II system separates cleanly i.e. a w/o droplet system at the 'natural' radius of the monolayer, co-existing with an essentially surfactant-free water phase. The SAXS I(Q) profiles show that major changes in aggregate shape occur as a function of w at constant surfactant concentration. At low surfactant concentrations, [AOT-] = 0.075 mol dm-3, the w = 0 reversed micelles, formed from diluting the H2 phase, are small near-spherical aggregates. The scattering is consistent with cylindrical micelles at low w, 5-10, and spherical w/o droplets at the Winsor II boundary w = 25.0. The results are explained in terms of the influence of parent H2 and co-existing water phases on the aggregate shapes in the L2 phase. We have used the SANS contrast variation method to investigate the internal cross-section structure of the cylindrical, w = 5.0, reversed micelles. The results show that the radius of the polar core, r, is only slightly larger than the hydrated radius of the [Co(water)6]2+ counterion and that the surfactant shell thickness, delta, is essentially equal to the length of the AOT hydrocarbon chains. This suggests an open staggered 'string of beads' structure for the micelles, rather than a polar core that can be significantly swollen with water. This model gives us some insight into structure of the lyotropic H2 phase