Sonar beamforming based upon monaural localisation techniques

Includes bibliographies.Sonar beamforming is usually accomplished using a multi-element transducer array. To obtain high resolution, such a system is costly and complex. In contrast, many mammals are capable of good angular resolution using only a single active element surrounded by an irregular reflector – the ear. A study of monaural localisation was therefore undertaken, with a view to the development of a novel beamforming system which uses only a single active element. Computer simulations have shown that the direction of a source can be determined by cross –correlating the output signal spectrum with the known spectral responses of the receiving system for all angles

Introducing visual participatory methods to develop local knowledge on HIV in rural South Africa

The authors would also like to acknowledge the field staff at the MRC/Wits Agincourt unit, particularly Ms Rirhandzu Debs and Dr Kerstin Edin from the Umeå Centre for Global Health Research, Umeå University, who facilitated data collection and made important contributions to the fieldwork.Peer reviewedPublisher PD

Initiating a participatory action research process in the Agincourt health and socio–demographic surveillance site

Financial disclosure Funding: The research presented in this paper is funded by a Development Grant as part of the Health Systems Research Initiative from Department for International Development (DFID)/Medical Research Council (MRC)/Wellcome Trust/Economic and Social Research Council (ESRC) (MR/N005597/1). The fieldwork was completed with the Umeå Centre for Global Health Research, with support from FORTE: Swedish Council for Health, Working Life and Welfare (grant No. 2006–1512). The School of Public Health at the University of the Witwatersrand, the South African Medical Research Council, and the Wellcome Trust, UK support the MRC/Wits Rural Public Health and Health Transitions Research Unit and Agincourt HDSS (Grants 058893/Z/99/A; 069683/Z/02/Z; 085477/Z/08/Z; 085477/B/08/Z). OW is a recipient of an MSc Chevening Scholarship, the UK government's global scholarship programme, funded by the Foreign and Commonwealth Office (FCO) and partner organizations (Chevening Ref.: NGCV–2015–1194).Peer reviewedPublisher PD

Moving from medical to health systems classifications of deaths : extending verbal autopsy to collect information on the circumstances of mortality

Acknowledgements The authors would also like to acknowledge the field staff at the MRC, SA/Wits Agincourt Unit, particularly Sizzy Ngobeni. The authors also acknowledge Drs Malin Eriksson and Edward Fottrell at Umeå Centre for Global Health Research *UCGHR) who contributed to the development of the SF-VA indicators, Dr Nawi Ng at UCGHR who advised on the cause of death categories, and Dr Kerstin Edin at UCGHR who provided comments on the manuscript categories, and Dr Kerstin Edin who provided comments on the manuscript. Funding A Health Systems Research Initiative Development Grant from the UK Department for International Development (DFID), Economic and Social Research Council (ESRC), Medical Research Council (MRC (and the Wellcome Trust (MR/N005597/1) funds the research presented in this paper. Support for the Agincourt HDSS including verbal autopsies was provided by The Wellcome Trust, UK (grants 058893/Z/99/A; 069683/Z/02/Z; 085477/Z/08/Z; 085477/B/08/Z), and the University of the Witwatersrand and Medical Research Council, South Africa.Peer reviewedPublisher PD

Pensions and Low Sodium Salt:A Qualitative Evaluation of a New Strategy for Managing Hypertension in Rural South Africa

BACKGROUND: This paper describes a pilot study to assess the feasibility of a novel intervention to improve the management of hypertension among older people in rural South Africa. Older South Africans have the highest rates of uncontrolled hypertension recorded for any country. Notably, South Africa has a widely-available old age grant (pension), which is delivered on a monthly basis to citizens living in rural villages.  METHODS: We assessed the feasibility of engaging with older people at the point of pension delivery in the Agincourt sub-district of Mpumalanga Province. This included providing information about hypertension, measuring blood pressure, referral to primary care services, and providing a monthly supply of low sodium salt. We recruited 20 people aged 60 and over to participate in the pilot intervention, which was conducted over three months in two villages. Towards the end of the intervention, we conducted focus groups with study participants and held a meeting with local stakeholders, including the district health office and the state social security agency.  RESULTS: The pilot study demonstrated (i) Sustained engagement with the original 20 participants. Of these, 19 continued to participate in the intervention during subsequent monthly pension days. (ii) A high level of acceptance of the low sodium salt product reflected in repeat usage and comments made in the focus groups. (iii) Strong support for the intervention and a willingness to collaborate with local stakeholders. (iv) A perception among participants that symptoms they associated with hypertension had abated. This is supported by blood pressure readings made over the three months of follow-up.  CONCLUSION: Though limited in scope, this pilot study provided evidence of the feasibility of the intervention and justification for it to be tested on a larger and more robust basis

Evidence for localised HIV related micro-epidemics associated with the decentralised provision of antiretroviral treatment in rural South Africa: a spatio-temporal analysis of changing mortality patterns (2007-2010).

BACKGROUND: In this study we analysed the spatial and temporal changes in patterns of mortality over a period when antiretroviral therapy (ART) was rolled out in a rural region of north-eastern South Africa. Previous studies have identified localised concentrated HIV related sub-epidemics and recommended that micro-level analyses be carried out in order to direct focused interventions. METHODS: Data from an ongoing health and socio-demographic surveillance study was used in the analysis. The follow-up was divided into two periods, 2007-2008 and 2009-2010, representing the times immediately before and after the effects on mortality of the decentralised ART provision from a newly established local health centre would be expected to be evident. The study population at the start of the analysis was approximately 73 000 individuals. Data were aggregated by village and also using a 2 × 2 km grid. We identified villages, grid squares and regions in the site where mortality rates within each time period or rate ratios between the periods differed significantly from the overall trends. We used clustering techniques to identify cause-specific mortality hotspots. FINDINGS: Comparing the two periods, there was a 30% decrease in age and gender standardised adult HIV-related and TB (HIV/TB) mortality with no change in mortality due to other causes. There was considerable spatial heterogeneity in the mortality patterns. Areas separated by 2 to 4 km with very different epidemic trajectories were identified. There was evidence that the impact of ART in reducing HIV/TB mortality was greatest in communities with higher mortality rates in the earlier period. CONCLUSIONS: This study shows the value of conducting high resolution spatial analyses in order to understand how local micro-epidemics contribute to changes seen over a wider area. Such analyses can support targeted interventions

Community perspectives on HIV, violence and health surveillance in rural South Africa : a participatory pilot study

Acknowledgements: The authors would like to acknowledge the study participants who contributed time and information and made significant contributions to the analysis, and the staff at the MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa. Funding: The analysis presented in this paper is supported by Health Systems Research Initiative Development Grant from DFID/MRC/Wellcome Trust/ESRC (MR/N005597/1). The fieldwork was completed with the Umeå Centre for Global Health Research, with support from FORTE: Swedish Council for Health, Working Life and Welfare (grant No. 2006–1512). The Agincourt HDSS is supported by the School of Public Health, University of the Witwatersrand, South African Medical Research Council and the Wellcome Trust, UK (Grants 058893/Z/99/A; 069683/Z/02/Z; 085477/Z/08/Z; 085477/B/08/Z)Peer reviewedPublisher PD

Mortality trends and access to care for cardiovascular diseases in Agincourt, rural South Africa : a mixed methods analysis of verbal autopsy data

Acknowledgments Thank you to the team at the Medical Research Council/Wits University Rural Public Health and Health Transitions Research Unit (Agincourt), particularly Chodziwadziwa Kabudula for his assistance with assembling the Agincourt HDSS data set for our use. The MRC/Wits Rural Public Health and Health Transitions Research Unit and Agincourt Health and Socio-Demographic Surveillance System, a node of the South African Population Research Infrastructure Network (SAPRIN), is supported by the Department of Science and Innovation, the University of the Witwatersrand, and the Medical Research Council, South Africa, and previously the Wellcome Trust, UK (grants 058893/Z/99/A; 069683/Z/02/Z; 085477/Z/08/Z; 085477/B/08/Z).Peer reviewedPublisher PD

Count Every Newborn: EN-INDEPTH study to improve pregnancy outcome measurement in population-based surveys.

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