The Southeast Indian Ridge between 88°E and 118°E: Variations in crustal accretion at constant spreading rate

The temperature of the mantle and the rate of melt production are parameters which play important roles in controlling the style of crustal accretion along mid-ocean ridges. To investigate the variability in crustal accretion that develops in response to variations in mantle temperature, we have conducted a geophysical investigation of the Southeast Indian Ridge (SEIR) between the Amsterdam hotspot and the Australian-Antarctic Discordance (88°E- 118°E). The spreading center deepens by 2100 m from west to east within the study area. Despite a uniform, intermediate spreading rate (69-75 mm yr- 1), the SEIR exhibits the range in axial morphology displayed by the East Pacific Rise and the Mid-Atlantic Ridge (MAR) and usually associated with variations in spreading rate. The spreading center is characterized by an axial high west of 102°45'E, whereas an axial valley is prevalent east of this longitude. Both the deepening of the ridge axis and the general evolution of axial morphology from an axial high to a rift valley are not uniform. A region of intermediate morphology separates axial highs and MAR-like rift valleys. Local transitions in axial morphology occur in three areas along the ridge axis. The increase in axial depth toward the Australian-Antarctic Discordance may be explained by the thinning of the oceanic crust by ~ 4 km and the change in axial topography. The long-wavelength changes observed along the SEIR can be attributed to a gradient in mantle temperature between regions influenced by the Amsterdam and Kerguelen hot spots and the Australian-Antarctic Discordance. However, local processes, perhaps associated with an heterogeneous mantle or along-axis asthenospheric flow, may give rise to local transitions in axial topography and depth anomalies

Sustainability of donor programs: evaluating and informing the transition of a large HIV prevention program in India to local ownership

Sustainability is the holy grail of many development projects, yet there is limited evidence about strategies that effectively support transition of programs from donor funding to national governments. The first phase of Avahan, the India AIDS Initiative supported by the Bill and Melinda Gates Foundation (2003–2009), aimed to demonstrate an HIV/AIDS prevention program at scale, primarily targeted at high-risk groups. During the second phase (2009–2013), this large-scale program will be transitioned to its natural owners: the Government of India and local communities. This paper describes the evaluation design for the Avahan transition strategy.A detailed logic model for the transition was developed. The Avahan transition strategy focuses on three activities: 1 enhancing capacities among communities, non-governmental organizations (NGOs), and government entities, in line with India's national AIDS control strategy; 2 aligning technical and managerial aspects of Avahan programs with government norms and standards; and 3 promoting and sustaining commitment to services for most-at-risk populations. It is anticipated that programs will then transfer smoothly to government and community ownership, become institutionalized within the government system, and support a sustained HIV/AIDS response.The research design evaluates the implementation and effectiveness of 1 activities undertaken by the program; 2 intermediate effects including the process of institutionalization and the extent to which key Avahan organizational procedures and behaviors are integrated into government systems; and 3 overarching effects namely the impact of the transition process on the sustained delivery of HIV/AIDS prevention services to high-risk groups. Both qualitative and quantitative research approaches are employed so that the evaluation will both assess outcomes and explain why they have occurred.It is unusual for donor-supported projects in low- and middle-income countries to carefully plan transition processes, and prospectively evaluate these. This evaluation is designed so as to both inform decision making throughout the transition process and answer larger questions about the transition and sustainability of donor programs

Examining sustainability in a hospital setting: Case of smoking cessation

<p>Abstract</p> <p>Background</p> <p>The Ottawa Model of Smoking Cessation (OMSC) is a hospital-based smoking cessation program that is expanding across Canada. While the short-term effectiveness of hospital cessation programs has been documented, less is known about long-term sustainability. The purpose of this exploratory study was to understand how hospitals using the OMSC were addressing sustainability and determine if there were critical factors or issues that should be addressed as the program expanded.</p> <p>Methods</p> <p>Six hospitals that differed on OMSC program activities (identify and document smokers, advise quitting, provide medication, and offer follow-up) were intentionally selected, and two key informants per hospital were interviewed using a semi-structured interview guide. Key informants were asked to reflect on the initial decision to implement the OMSC, the current implementation process, and perceived sustainability of the program. Qualitative analysis of the interview transcripts was conducted and themes related to problem definition, stakeholder influence, and program features emerged.</p> <p>Results</p> <p>Sustainability was operationalized as higher performance of OMSC activities than at baseline. Factors identified in the literature as important for sustainability, such as program design, differences in implementation, organizational characteristics, and the community environment did not explain differences in program sustainability. Instead, key informants identified factors that reflected the interaction between how the health problem was defined by stakeholders, how priorities and concerns were addressed, features of the program itself, and fit within the hospital context and resources as being influential to the sustainability of the program.</p> <p>Conclusions</p> <p>Applying a sustainability model to a hospital smoking cessation program allowed for an examination of how decisions made during implementation may impact sustainability. Examining these factors during implementation may provide insight into issues affecting program sustainability, and foster development of a sustainability plan. Based on this study, we suggest that sustainability plans should focus on enhancing interactions between the health problem, program features, and stakeholder influence.</p

Crustal thickness variations along the Southeast Indian Ridge (100°–116°E) from 2-D body wave tomography

Axial morphology along the Southeast Indian Ridge (SEIR) systematically changes from an axial high to a deep rift valley at a nearly uniform intermediate spreading rate between 100°–116°E, west of the Australian-Antarctic Discordance (AAD). Basalt geochemistry has a consistent Indian–mid-ocean ridge basalt (MORB) type isotopic signature, so changes in axial topography are attributed to variations in both mantle temperature and melt supply. Wide-angle seismic refraction lines were shot to four ocean bottom hydrophones within SEIR segments P1, P2, S1, and T, where each segment is characterized by a different morphology. We constructed 2-D crustal velocity models by jointly inverting hand-picked P wave refraction (Pg) and Moho reflection (PmP) traveltime data using a top-down, minimum-structure methodology. The results show a 1.5 km eastward decrease in crustal thickness across the study area, with segment averages ranging from 6.1 km at P1 to 4.6 km at T. Melt generation models require a ~30°C decrease in mantle temperature toward the AAD to account for the crustal thickness trend. Significant changes in axial morphology accompany small-scale variations in crustal thickness, consistent with models of crustal accretion where ridge topography is determined by a balance between mantle temperature, melt supply, and cooling from hydrothermal circulation. Layer 3 thins by 3.0 km as layer 2 thickens by 1.4 km between segments P1 and T, reflecting the eastward decrease in melt supply and increase in melt lens depth. The trade-off in seismic layers may be explained by models relating the increase in overburden pressure on a deepening melt lens to the volume of magma erupted into the upper crust rather than cooling at depth to form new lower crustal material

The barriers and facilitators influencing the sustainability of hospital-based interventions: a systematic review

Acknowledgements University of Stirling for providing financial support for open access costs Funding This review was funded by the Chief Scientist Office, grant number GCA/17/26. JC, PC and EAD are employed by the Nursing, Midwifery and Allied Health Professions Research Unit, which is funded by the Chief Scientist Office in Scotland.Peer reviewedPublisher PD