Oesophageal cancer is one of the most common causes of cancer-related deaths in South African black males. The limited efficacy of chemotherapeutic agents to treat this disease has prompted a search for potential new chemical entities with anticancer properties. We report here on the evidence for anti-oesophageal cancer activity in the methanolic extracts of five species of sponges dredged from a depth of approximately 100 m in the vicinity of Marion Island in the Southern Ocean during the autumn of 2004.

No description available.

Terracettes and turf-banked terraces exist at Tiffindell Ski Resort in the Drakensberg of the Province of the Eastern Cape at altitudes between 2750 m and 2880 m on slopes of between 15°and 26°. Ice lenses and interstitial ice exist within turf-banked terraces in winter. During post-winter thaws, soil moisture reaches saturation in at least the upper part of the regolith in which turf-banked terraces occur. These terraces move downslope under the influence of gelifluction (which is essentially a combination of frost creep and solifluction). Terracettes appear to move as a result of frost creep, processes associated with needle ice, and slope wash. Both turf-banked terraces and terracettes are part of the periglacial environment and are active under present climatic conditions at Tiffindell.

The manufacturing economy of the Free State reflects both historical dependence on locally available raw materials and high-levels of state intervention, in terms of support for import substitution and Homeland development. In the contemporary era, deindustrialization, the uncertain future of the clothing / textile industries and limited growth over the last ten years, suggests that, in terms of manufacturing, the Free State is a 'lagging' region. While there has been significant expansion in the number of small firms, this is not matched by employment growth and does not compensate for the loss of many large firms and economic downscaling in the Goldfields. Key sectors such as petro-chemicals and gold jewellery present certain opportunities for future growth.

Human exploitation of intertidal organisms in South Africa is an ancient activity based principally on mussels. We studied mussel populations and patterns of exploitation along a 160-km stretch of the south coast. Photographs (100 per site) were taken of the intertidal rocks at each of 14 sites, covering a range of exploitation intensities. Percentage cover was negatively correlated with number of mussel patches and positively correlated with mean shell width. PCA analysis identified groups of sites: a) accessible and unprotected sites: low cover, small mussels, patchy distribution; b) inaccessible sites and sites next to, or within, nature reserves: high percentage cover, large animals, less patchy distributions. Affluent coastal settlements also seem to confer protection against harvesting. Harvester distribution was examined by aerial surveys and combined with information on distance to the nearest beach access point and number of households within 7 km for each site. Sites within reserves and inaccessible sites had low densities of collectors, whereas sites near urban areas and in the Ciskei had the highest densities. All correlations between indicators of human exploitation and condition of mussel populations were non-significant. However, number of collectors showed positive trends with number of patches and negative trends for the two other variables. The results indicate much lower levels of exploitation than in the neighouring Transkei region, and suggest a high degree of background variability in mussel population structure.

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Intertidal size-frequency distributions and densities for Haliotis midae and Turbo sarmaticus were examined at 10 sites experiencing varying pressure of human exploitation along the southern section of the Eastern Cape coast, South Africa. Target species' densities and maximum sizes were related both to the numbers of collectors on the shore and to indirect indicators of exploitation such as number of households in the vicinity and distance to the nearest beach access point. For both species, there was variation in density (P < 0.05) and size (P < 0.05) among sites, with densities ranging between 0.03-2.23 m^(-2) and 0.07-4.93 m^(-2) for H. midae and T. sarmaticus, respectively. Maximum sizes ranged between 49.4-153.5 mm (H. midae) and 28.3-104.4 mm (T. sarmaticus) shell length. Population parameters such as mean maximum size and total density were significantly negatively related to exploitation indicators for both species. In addition, densities of sexually mature and legal-size individuals of T. sarmaticus were significantly negatively related to the number of households. However, only for H. midae were densities of subadults significantly negatively related to the number of collectors, suggesting that reproduction of abalone may be suppressed at the most exploited sites. Exploitation of T. sarmaticus tends to be localized near population centres, whereas H. midae is collected over a larger range of sites. Overall, T. sarmaticus is less affected by exploitation than H. midae.

The research team presents the findings of a comprehensive investigation into the status and role of Geography as an academic discipline in South Africa. The paper begins by placing the discipline in historical and epistemological context. Extensive and intensive interviews were conducted with geographers at all South African universities and, on a smaller scale, in the workplace. Information was also gleaned from an array of documents. Comments on the characteristics of university departments, general school education, the geography research environment the geographer in the workplace are given. Emerging trends, many of which relate to recent socio-political change, show that contemporary emphasis is on applied geography, specific fields of specialisation, the accommodation of Environmental Science and Environmental Management, skills training and on curriculum development with a marked vocational orientation. As geographers continue addressing national and international environmental and social issues in their professional endeavours, they are alerted to critical concerns voiced with conviction by practising geographers. In the final analysis a positive conclusion is reached and the academic merit and status of the discipline is confirmed.

The Geography of African Development module is part of a year-long Third Year level geography course on Africa that has been offered at Rhodes University since 2002. The course is an exception to the dominant trend, both locally and internationally, which has witnessed a major decline in the teaching of regional geography and area studies. This paper examines how adopting a constructivist approach to the module's curriculum enabled learners to develop geographical skills at the same time as Africanising the curriculum.

The Fast Track Land Reform Programme is the defining instrument for Zimbabwe’s future development prospects. In the three year period from 2000 to 2002 300,000 families were resettled on 11 million hectares thus witnessing the end of the colonial division of land which had seen 15.5 million hectares still in European hands in 1980, the start of the post-colonial period. The process which displaced the commercial farm workers and farm owners was chaotic, violent and disorderly and so has been called jambanja. Subsequent legislation and government agricultural initiatives have attempted to impose, retroactively, technocratic order to the sweeping changes that have taken place. Our study shows that the dire macro-economic situation coupled with trends of HIV/AIDS prevalence means that developing sustainable land use practices is going to be a very difficult proposition. At the local scale, our case studies show that there have been multiple outcomes with low investment, very limited government support and resource extraction leading to land degradation and unsustainable farming practices. In some instances, however, individual households have benefitted in the short term from the process but this has only occurred where climatic and soil conditions have been particularly favourable.