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African savanna elephants (Loxodonta africana) are significant ecosystem engineers – having profound effects on the vegetation when at high population densities. To provide a context for modern conservation decisions it would be useful to know the 'natural' population densities prior to the arrival of firearms in Africa. Here, we use botanical and archaeological arguments to suggest a lower density of elephant populations than in some present protected areas over at least the last few millennia, and arguably much longer. This suggests that elephant population densities seen in some protected areas during the second half of the twentieth century are likely higher than those seen in the past and so have the potential to result in significant negative impacts on associated fauna and flora. [ABSTRACT FROM AUTHOR]

Changes in the extent of woody vegetation represent a major conservation question in many savannah systems around the globe. To address the problem of the current lack of broad-scale cost-effective tools for land cover monitoring in complex savannah environments, we use a multi-scale approach to quantifying vegetation change in Kruger National Park (KNP), South Africa. We test whether medium spatial resolution satellite data (Landsat, existing back to the 1970s), which have pixel sizes larger than typical vegetation patches, can nevertheless capture the thematic detail required to detect woody encroachment in savannahs. We quantify vegetation change over a 13-year period in KNP, examine the changes that have occurred, assess the drivers of these changes, and compare appropriate remote sensing data sources for monitoring change. We generate land cover maps for three areas of southern KNP using very high resolution (VHR) and medium resolution satellite sensor imagery from February 2001 to 2014. Considerable land cover change has occurred, with large increases in shrubs replacing both trees and grassland. Examination of exclosure areas and potential environmental driver data suggests two mechanisms: elephant herbivory removing trees and at least one separate mechanism responsible for conversion of grassland to shrubs, theorised to be increasing atmospheric CO2. Thus, the combination of these mechanisms causes the novel two-directional shrub encroachment that we observe (tree loss and grassland conversion). Multi-scale comparison of classifications indicates that although spatial detail is lost when using medium resolution rather than VHR imagery for land cover classification (e.g., Landsat imagery cannot readily distinguish between tree and shrub classes, while VHR imagery can), the thematic detail contained within both VHR and medium resolution classifications is remarkably congruent. This suggests that medium resolution imagery contains sufficient thematic information for most broad-scale land cover monitoring requirements in heterogeneous savannahs, while having the benefits of being cost-free and providing a longer historical archive of data than VHR sources. We conclude that monitoring of broad-scale land cover change using remote sensing has considerable potential as a cost-effective tool for both better informing land management practitioners, and for monitoring the future landscape-scale impacts of management policies in savannahs. [ABSTRACT FROM AUTHOR]

Abstract: Background: There is increasing evidence that many populations in the developing world are in “epidemiologic transition” with the subsequent emergence of more “affluent” disease states. The “Heart of Soweto Study” will systematically investigate the emergence of heart disease (HD) in a large urban population in South Africa. Methods: Part of the conurbation of Johannesburg, South Africa, Soweto is a predominantly Black African community of 1 million individuals. During an initial two year period, all individuals presenting to the local Baragwanath Hospital (3500 beds) with any form of HD will be studied. Demographic and diagnostic coding data in those with pre-established HD will form an abbreviated clinical registry of >12,000 “prevalent” cases. Similarly, socio-demographic, clinical and diagnostic data (e.g. echocardiography and ECG) in newly diagnosed patients will form a more detailed clinical registry of >5000 “incident” cases. Sub-studies of the relationship between HIV status and HD and the optimal management of chronic heart failure will also be performed. Results: These data will provide a unique insight into the causes and consequences of a broad spectrum of HD-related conditions in a “developing world” community in epidemiologic transition. Initially documented population rates, in addition to detailed examinations of the underlying risk factors and causes of HD-related morbidity/mortality will provide an important platform for future stages of the study: a community-based, population screening program and culturally specific primary and secondary programs of care. Conclusion: There is an urgent need to systematically track the emergence of HD in the developing world. Initially involving more than 15,000 individuals, the unique Heart of Soweto Study has the potential to provide a wealth of information in this regard. [Copyright &y& Elsevier]

Application of geographic information system (GIS) and global positioning system (GPS) technology in the Hlabisa community-based tuberculosis treatment programme documents the increase in accessibility to treatment after the expansion of the service from health facilities to include community workers and volunteers. [ABSTRACT FROM AUTHOR]