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Endothermy and chorusing behaviour in the African platypleurine cicada Pycna semiclara (Germar, 1834) (Hemiptera: Cicadidae)

  • Authors: Villet, Martin H , Sanborn, Allen F , Phillips, Polly K F
  • Date: 2003
  • Language: English
  • Type: text , Article
  • Identifier: vital:6892 , http://hdl.handle.net/10962/d1011652 , http://dx.doi.org/10.1139/z03-119
  • Description: Cicadas use acoustic signals to find mates and therefore offer a phylogenetically independent opportunity to test the generality of ideas about acoustic communication that were developed from studies of other animals. Pycna semiclara (Germar, 1834) (Hemiptera: Cicadidae) is a forest-dwelling platypleurine cicada that uses its calling song to form choruses and attract mates. Additionally, P. semiclara produces an encounter call that is involved in courtship and also in spacing males within choruses. Males generally call from exposed trunks and branches within the understory but clear of the undergrowth and fight with other males that call within about 50 cm of them. Choruses sing sporadically throughout the day but focus most of their calling activity into half-hour bouts at dawn and dusk. Body size and ambient temperature had no significant effect on spectral or temporal characteristics of the calling song. Body temperature measurements indicate that P. semiclara thermoregulates endothermically, with a body temperature of more than 22 °C above ambient temperature being measured during calling activity at dusk. Such endothermy provides an advantage to the cicadas by allowing them to call during crepuscular hours when atmospheric conditions are most optimal for acoustic communication and predation risks are minimal. Coincidentally, endogenously regulating body temperature allows the temporal characteristics of the call to be unaffected by ambient temperature changes.
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Environmental limits to the distribution of Scaevola plumieri along the South African coast

  • Authors: Peter, Craig I , Ripley, Bradford S , Robertson, Mark P
  • Date: 2003
  • Language: English
  • Type: Article
  • Identifier: vital:6872 , http://hdl.handle.net/10962/d1011617
  • Description: Scaevola plumieri is an important pioneer on many tropical and subtropical sand dunes, forming a large perennial subterranean plant with only the tips of the branches emerging above accreting sand. In South Africa it is the dominant pioneer on sandy beaches along the east coast, less abundant on the south coast and absent from the southwest and west coasts. Transpiration rates (E) of S. plumieri are predictably related to atmospheric vapour pressure deficit under a wide range of conditions and can therefore be predicted from measurement of ambient temperature and relative humidity. Scaling measurements of E at the leaf level to the canopy level has been demonstrated previously. Using a geographic information system, digital maps of regional climatic variables were used to calculate digital maps of potential transpiration from mean monthly temperature and relative humidity values, effectively scaling canopy level transpiration rates to a regional level. Monthly potential transpiration was subtracted from the monthly median rainfall to produce a map of mean monthly water balance. Seasonal growth was correlated with seasonal water balance. Localities along the coast with water deficits in summer corresponded with the recorded absence of S. plumieri, which grows and reproduces most actively in the summer months. This suggests that reduced water availability during the summer growth period limits the distribution of S. plumieri along the southwest coast, where water deficits develop in summer. Temperature is also important in limiting the distribution of S. plumieri on the southwest coast of South Africa through its effects on the growth and phenology of the plant.
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Ethics beyond the code of conduct - understanding the ethical dilemmas of entrepreneurs

  • Authors: Robinson, D A , Van der Mescht, Hennie , Lancaster, Jonathan C S
  • Date: 2003
  • Subjects: To be catalogued
  • Language: English
  • Type: Article
  • Identifier: vital:6072 , http://hdl.handle.net/10962/d1001646 , ISSN 1022-2529
  • Description: Entrepreneurs choose a particular way of life with the dual aim of maximising profit and gaining a sense of self-satisfaction. In these endeavours, entrepreneurs typically live with the threat of competition and the risk of business failure, while attempting to do their best within the limitations of their resources. This qualitative study first examines existing theories of ethics and ways of applying business ethics and thereafter investigates entrepreneurs' actual experiences by means of in-depth interviews and the use of phenomenology. It finds that entrepreneurs are not guided by any specific code of conduct, and must decide for themselves what is right. It describes the entrepreneurial business ethic, some of the types of dilemmas that they experience and the methods that they have developed to deal with the dilemmas.
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Evaluating people-environment relationships : developing appropriate research methodologies for sustainable management and rehabilitation of riverine areas by communities in the Kat River Valley, Eastern Cape Province, South Africa

  • Authors: Motteux, Nicole
  • Date: 2003
  • Subjects: Water-supply -- South Africa -- Kat River Valley -- Management Rural development -- Environmental aspects -- South Africa -- Kat River Valley Kat River Valley (South Africa) Human ecology -- South Africa -- Kat River Valley Stream ecology -- South Africa -- Kat River Valley
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4828 , http://hdl.handle.net/10962/d1005503
  • Description: International evidence clearly indicates that water shortages and the enhanced value attached to water and aquatic ecosystems are key concerns faced by many countries. International experience, since the mid-1980s, has emphasised the importance of addressing political, social, environmental and economic issues through active stakeholder participation in riverine and water resource management. These trends and issues are relevant to South Africa, where integrated water resource management (IWRM) is now a cornerstone of water resource policy and the National Water Act (NWA). Apartheid excluded communities in former homelands (racial reserves) from participation in IWRM. The research presented in this thesis was based on the search for philosophies and methods to involve the rural, former homeland people of the Kat River Valley in South Africa in IWRM. Post-modern, humanist and some logical positivist geographical philosophies were used during the research. This research applied Participatory Rural Appraisal (PRA) philosophy and methods and was influenced by the seminal work of Paolo Freire (1972). In addition, the use of innovative methods for engagement of the oppressed, using theatre methods developed by Augusto Boal (1995, 2000) was explored to add value to PRA. In addition, the application of Action Research ensured that community participants were actively involved in the research being conducted for this thesis. The applied research in the Kat River Valley in South Africa evolved through three key phases. In Phase One quantifiable data on the Kat River Valley and its residents was sought. This investigation did not empower the resident communities of Fairbairn and Hertzog – a lesson that influenced the move to more participatory methods in subsequent phases of the research. Lessons learned from using surveys encouraged exploration of participatory methods to enable participants to become “co-learners”. Phase Two of the research commenced with a series of feedback meetings, in which participants recognised that they faced an environmental crisis. Through a series of participatory workshops, residents came to acknowledge and affirm their environmental knowledge. Residents then committed themselves to gaining a deeper understanding of their environment and their lives. My role changed from that of a researcher to a facilitator. Phase Three of the research and the shift to Action Research commenced after local residents identified the need to personally take charge of their environmental challenges in the Kat River Valley and recognised the need to collaborate at a catchment scale for effective IWRM. This eventually led to the formation of a Water User Association and Catchment Forum. The key theoretical contribution of the thesis relates to the identified relationship between the development orientation and ecological paradigm, and an assessment of the impact this has on the inputs, processes, outputs and outcomes of IWRM. This theoretical contribution is equally valid in other countries, where the tradeoffs are essentially the same, but the framework for making the choices is different because of varying socio-economic and biophysical circumstances
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Evolution of a strongly differentiated suite of phonolites from the Klinghardt Mountains, Namibia

  • Authors: Marsh, Julian S
  • Date: 2003
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/140400 , vital:37885 , https://doi.org/10.1016/0024-4937(87)90023-5
  • Description: Phonolites of Tertiary age occur as eroded tholoids, lava flows, ignimbrites, and coulees in the Klinghardt Mountains of southern Namibia. Sixty samples have been analyzed for major and trace elements and fourteen of these for 87SR 86SR. The phonolites lie close to the low-pressure cotectics in Q-Ne-Ks, in keeping with their petrography which indicates that most samples have phenocrysts of both nepheline and sanidine. Na has been variably lost from the rocks during crystallization and devitrification/alteration of hypocrystalline specimens.
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Exploring differences between organisational cultures in a company undergoing change

  • Authors: Bowa, Mabvuto
  • Date: 2003
  • Subjects: Organizational change -- Africa , Corporate culture -- Africa , Management -- Africa , Organizational behavior -- Africa
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:3126 , http://hdl.handle.net/10962/d1006287 , Organizational change -- Africa , Corporate culture -- Africa , Management -- Africa , Organizational behavior -- Africa
  • Description: Change is a common phenomena in business organisations today. The turbulent environment is exerting a significant influence on organisations to make continuous changes in their internal environment in an attempt to improve performance and achieve competitiveness in the marketplace. The human factors which confront organisations undergoing change have not been thoroughly investigated in Sub-Saharan Africa. The present study aimed at investigating human issues affecting the performance ofan organisation located in an Afiican country. Data was collected using semi-structured interviews and focus groups. Twenty interviews were conducted with employees randomly selected from all the levels of the company, namely attendant, operator, supervisory, middle and top management. Five focus groups were carried out with employees from different employee categories. Both sets of data were analysed using grounded theory. The findings showed that there were several problems in the company including insecurity, lack of opportunities for employee development, autocratic management style, lack of participation in decision making, substandard performance, ineffective human resources systems and lack of adaptation to technology. It was suggested that the problems resulted from the clash between organisational cultures in the company. At one level, there was a clash between the local workers' socialist organisational culture and the expatriates' capitalistic organisational culture. At a more deeper level, the clash appeared to be between the local employees' collectivistic sociocultural values and the expatriates' individualistic value system. These findings have significant implications for managing change in organisations with diverse cultures.
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External and domestic sources of foreign policy ambiguity: South African foreign policy and the projection of pluralist middle power

  • Authors: Bischoff, Paul, 1954-
  • Date: 2003
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/161442 , vital:40627 , https://doi.org/10.1080/0258934032000147291
  • Description: As a pluralist middle power, post-apartheid South Africa seeks to generate successful foreign policy initiatives at bilateral, multilateral and regional levels in order to shape international outcomes. In this endeavour, it has three important political resources – a recognition of its geo-political position and importance as a democratic yardstick and reformer; its acceptance of a transnational, neo-liberal elite alliance and finally, recognition of its leadership role from forces wishing to challenge African political establishments. However, the international and domestic political environment which in the mid-1990s was favourable towards middle-power initiative and reform has narrowed.
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Finite element modelling of a magma chamber surrounded by country-rock, with particular reference to the groundwater flow in sections of different permeability

  • Authors: Remsing, Carmen
  • Date: 2003 , 2013-05-23
  • Subjects: Magmas , Groundwater flow
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5508 , http://hdl.handle.net/10962/d1007537 , Magmas , Groundwater flow
  • Description: This thesis presents results of two-dimensional finite element modelling of a magma chamber surrounded by country-rock containing a section of high permeability. The high permeability section in the country-rock simulates structure that is predominant in controlling the groundwater convection pattern and resulting mineral deposits. The models have analogies in nature: for instance the gold mines in the Massif Central of France, the Pogo mine in Alaska and the Pilgrim's Rest gold field in South Africa. This is a complicated coupled system involving fluid flow and heat transfer under extreme conditions. The magma in the chamber convects and as it cools the heat liberated causes convection in the groundwater contained in the surrounding country-rock. This convection in turn affects the rate of liberation of heat from the magma. The software used for the modelling, FLOTRAN, is the computational fluid dynamics component of the commercial ANSYS package. The results obtained describe in detail the flow pattern in the magma chamber, the country-rock and high permeability section thereof. During the cooling of the magma chamber the groundwater convects more vigorously in the high permeability section than elsewhere, and a convection cell is seen forming within this region. This provides a mechanism for hydrothermal formation of valuable mineral deposits in the structure near a magma chamber. It is found that the relationship between the velocity of the flow in the cell and the temperature of the magma chamber is well represented by a first order linear differential equation, providing a simple understanding of this process, , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
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Foam drug delivery in dermatology: beyond the scalp

  • Authors: Purdon, Carryn H , Haigh, John M , Surber, Christian , Smith, Eric W
  • Date: 2003
  • Subjects: Adis International Limited , Drug delivery systems , Skin disorders
  • Language: English
  • Type: text , Article
  • Identifier: vital:6418 , http://hdl.handle.net/10962/d1006541
  • Description: Consumers of topical formulations apply a wide spectrum of preparations, both cosmetic and dermatological, to their healthy or diseased skin. These formulations range in physicochemical nature from solid through semisolid to liquid. Pharmaceutical foams are pressurized dosage forms containing one or more active ingredients that, upon valve actuation, emit a fine dispersion of liquid and/or solid materials in a gaseous medium. Foam formulations are generally easier to apply, are less dense, and spread more easily than other topical dosage forms. Foams may be formulated in various ways to provide emollient or drying functions to the skin, depending on the formulation constituents. Therefore, this delivery technology should be a useful addition to the spectrum of formulations available for topical use; however, as yet, only a few are commercially available. Probably the most convincing argument for the use of foams is ease of use by the patient, and consumer acceptance. Most foam dosage forms used in dermatology to date have incorporated corticosteroids, although some products have also been used to deliver antiseptics, antifungal agents, anti-inflammatory agents, local anesthetic agents, skin emollients, and protectants. Although there is no clinical evidence that foam formulations are currently superior to other conventional delivery vehicles, these formulations have a clear application advantage and with continued developments in the science of supersaturation technology, it seems certain that foam delivery systems will retain their place in the dermatological and cosmetic armamentarium.
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From labour reserve to investment opportunity: economic development planning in the Mbashe Local Municipal area in the Eastern Cape

  • Authors: Reynolds, John Hunter
  • Date: 2003
  • Subjects: Economic development -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , South Africa -- Economic policy , Planning -- South Africa -- Eastern Cape
  • Language: English
  • Type: Thesis , Masters , MSocSc
  • Identifier: vital:3353 , http://hdl.handle.net/10962/d1007490 , Economic development -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , South Africa -- Economic policy , Planning -- South Africa -- Eastern Cape
  • Description: Planning for economic development at the local level has become increasingly important in many countries of the world. South Africa is no exception and has had the local focus entrenched through constitutional provisions for developmental local government. This developmental approach has been intimately linked to, and influenced by, the broader legislative, policy and planning context within which the development challenges of post-Apartheid South Africa have been addressed. It has also been implemented in a context of far-reaching transformation of public institutions aimed, in the final analysis, at the effective functioning of three spheres of government. In this thesis, the Mbashe Local Municipal area is used as a case study for an examination of the linkages between economic development planning at the local, provincial and national levels. It is not a case study in the sense that an in-depth analysis of practice is undertaken; it is used rather as a lens through which the economic development planning activities of the three spheres of government are viewed. Its value as a lens lies in its location in the former Transkei, which is characterised by high levels of unemployment and poverty and low levels of service infrastructure, and in its status as one of the newly demarcated local municipalities in South Africa. Mbashe is a pilot site of the Promotion of Rural Livelihoods Programme, which has been linked to the Eastern Cape Province's Integrated Sustainable Rural Development Programme. It also includes one of the nodes of the Wild Coast Spatial Development Initiative, which has, since 1998, been promoted as a vehicle for economic development in the former Transkei. Research comprised extensive documentary research, individual interviews with key role players in the Mbashe Local Municipality, the Promotion of Rural Livelihoods Programme and the Wild Coast Spatial Development Initiative, and a group interview with members of the Local Economic Development Sub-Committee of the Mbashe Local Municipal Council. An attempt was made to understand the complex layers of policy and planning frameworks that guide planning at the national and provincial levels and within which local level economic development is situated, and to explore the responses that have been forged by agents within the Mbashe area. Key in this endeavour has been the initiatives developed under the guidance of the Mbashe Local Economic Development Sub-Committee. It is argued that the severe resource constraints faced within Mbashe, combined with limited knowledge of and participation in larger planning and resource mobilisation frameworks, lock Local Economic Development within the top-down and investmentled approaches, rather than the more integrated approach that is promoted in terms of legislation and that is required if poverty is to be addressed successfully. The limitations on state fiscal expenditure and the market-led approach to service provision and economic development, implemented in terms of South Africa's macroeconomic framework, combined with limited synchronisation of planning cycles in which integrated development planning at the local level is privileged, leave little scope for endogenous economic development at local level. There is scope for creative engagement with the interlocking local, provincial, national and continental economies by actively shifting resources in support of integrated, endogenous approaches. Such approaches could serve as counter-narratives to the dominance of neoliberalism and allow for the establishment of local economic development practice that addresses the needs of the poor and that builds integrated local economies under the control of democratic institutions. It is only with such a shifting of approach that economic development within Mbashe will shift the structural conditions that lock it into economic dependence and poverty.
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Fuelwood availability and use in the Richtersveld National Park, South Africa

  • Authors: Shackleton, Charlie M , Guthrie, G , Keirungi, J , Stewart, J
  • Date: 2003
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/181461 , vital:43736 , xlink:href=" https://doi.org/10.4102/koedoe.v46i2.66"
  • Description: Concern has been voiced about the possible over-use of fuelwood from the riparian fringe by pastoralist herders in the Richtersveld National Park (RNP). This coincided with the current examination and modelling of the supply and use of ecosystem goods and services in the Gariep Basin as part of the Southern African Millennium Assessment (SAfMA). This paper reports on a study to index the current availability of deadwood within the riparian zone of RNP, its relationship with proximity to human habitation, and species preferences of the local herders. Deadwood availability was assessed per woody species and on the ground in 12 transects within the riparian fringe. Herders were interviewed regarding their species preferences, and the composition of woodpiles was examined. There was no relationship between the percentage of attached deadwood on the tree, or the percentage deadwood ground cover, and the distance from herder stockposts. Euclea pseudobenus and Tamarix usneoides were the dominant species in the riparian fringe. There was strong selection for Ziziphus mucronata as a fuelwood species and only marginal or random selection for E. pseudobenus. Tamarix usneoides and Prosopis sp. were abundant in the riparian zone, but were not used for fuelwood. There was a significant difference between species with respect to the mean proportion of the stem that was dead, the highest being Z. mucronata (± 28 % deadwood), followed by T. usneoides (± 12 %). Most of the Prosopis trees had no deadwood. Across all species, the mean percentage dead per tree was approximately 15 %. Additionally, detached deadwood covered just less than 9 % of ground area, averaged across all plots and transects. All the variables measured indicated that there seems to be little need for concern over the current fuelwood extraction activities of pastoralists within the RNP. There was no clear evidence of cutting of branches or deadwood. The abundance of both attached and detached deadwood was not depleted close to human habitation. There was still abundant deadwood, even on preferred species. The most preferred species (Ziziphus mucronata) had the greatest mean proportion of deadwood. The herders stated that they only used deadwood, and that there was plenty. They rarely used driftwood washed down the river, although there was an abundance of it. Thus, overall, there was no sign of depletion of the deadwood resource, even on favoured species, or degradation of the productive capacity for deadwood.
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Genetic variation within two pulmonate limpet species, Siphonaria capensis and S. serrata along the South African coast

  • Authors: Seaman, Jennifer Ann
  • Date: 2003
  • Subjects: Limpets -- South Africa Pulmonata Siphonaria Limpets -- Genetics
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:5800 , http://hdl.handle.net/10962/d1006155
  • Description: Dispersal rates are known to play a fundamental role in establishing the genetic structure found within a species. Dispersal in marine benthic invertebrates is largely dependent on life history strategy. The presence of pelagic larvae will potentially result in high dispersal within a species, while direct development limits dispersal. This study used two intertidal pulmonate limpet species to investigate the relationship between dispersal potential and genetic structure of populations. Siphonaria capensis produces benthic egg masses, which release pelagic larvae. These float in ocean currents before settling and metamorphosing into adults. S. serrata reproduces by direct development. The larvae hatch as completely metamorphosed juveniles after developing in an egg case not far from the parent. The high dispersal capacity of S. capensis pelagic larvae should result in high levels of within-population variation since individuals within a particular population may originate from several different populations. This should lead to high levels of gene flow along the coast and to low genetic differentiation among populations. On the other hand, the low dispersal potential of S. serrata should cause low levels of genetic variation within populations, as relatives will remain close to one another. Low levels of gene flow and high genetic differentiation among populations are expected in this species. In dealing with the relationship between life history strategy and population genetic structure in these two species, a series of indirect techniques was utilised. Multivariate analyses of the morphological variation within each species showed that variation in size was similar between the two species and largely governed by environmental factors. Variation in shell shape was largely under genetic control and supported the predictions made for each species. Variation in total proteins was relatively uninformative in terms of examining the differences between the two species. Allozyme analysis and mtDNA sequencing clearly showed differences between the species in terms of their population genetic structure. High levels of gene flow were found within S. capensis. This was strongly influenced by ocean currents, with the close inshore Agulhas current along the Transkei coast contributing to high levels of dispersal and hence gene flow. Low levels of gene flow occurred within S. serrata, resulting in low within-population variation and high among-population differentiation.
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Geographical races of the honeybees (Apis Mellifera L.) of the Northern regions of Ethiopia

  • Authors: Mohammed, Nuru Adgaba
  • Date: 2003
  • Subjects: Honeybee -- Ethiopia Honeybee -- Behavior -- Ethiopia Honeybee -- Ethiopia -- Morphology Honeybee -- Ecology -- Ethiopia
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:5827 , http://hdl.handle.net/10962/d1007671
  • Description: The ideal climatic conditions and diversity of floral resources allow Ethiopia to sustain millions of honeybee colonies. Beekeeping is widely practiced and plays a significant role in the livelihood of the farming community of the country. Despite this, information on the types of geographical races of honeybees, their behavioural characters and the related ecological factors are not established. In this work an attempt was made to characterise the honeybee populations of the northern parts of Ethiopia based on the analyses of morphological, behavioural and ecological characteristics. For morphological analysis, 155 honeybee colony samples from 31 localities were collected. 20 worker honeybees per colony sample totalled 3100 individual worker honeybees and thirteen morphological characters per bee, a total of 40 300 measurements were recorded following Ruttner's (1988) protocols. The behavioural characters such as reproductive swarming, migration, temperament and colony seasonal cycles were assessed based on survey work of a pre-structured questionnaire. Various univariate and multivariate statistical methods were employed to analyse the data. The principal components and step-wise linear discriminant analyses revealed the existence of four discrete morphoclusters or geographical races: A. m. jemenitica from eastern, northwestern and northern arid and semi-arid lowlands, A. m. scutellata from the western humid midlands, A. m. bandasii from sub-moist central highlands and A. m. monticola from the northern mountainous parts of the study areas. These different geographical races were found to be distinctively distributed in the different ecological parts of the study area. High intercolonial and intracolonial variances were observed in all localities, however particularly high values were obtained in areas of transitions between ecological zones indicating a region of gene flow or zones of hybridisation among the statistically defined populations. Such high variances were observed mostly in areas where A. m. jemenitica borders the other geographical races. Moreover. distinct behavioural variations were also noted among these geographical races. Generally. the highland and mountainous honeybees A. m. bandasii and A. m. monticola are relatively larger in body size. have less tendency to swarm. less inclination to migrate and are relatively gentle while the converse traits were noted for the lowlands and midlands honeybees A. m. jemenitica and A. m. scutellata. Both morphological and behavioural variations were highly correlated with environmental factors and the variations seem to be the result of long adaptation to the interrelated ecological factors in their respective areas. Variations in reproductive swarming periods were also noted among these honeybee populations as a result of variations in rainfall pattern. altitude and temperature in their respective ecological areas which are believed to alter the honeybee colonies' seasonal cycles and leads to partial temporal reproductive isolation among these different honeybee populations.
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Geography : the state of the discipline in South Africa (2000 - 2001)

  • Authors: Fairhurst, U J , Davies, R J , Fox, Roddy C , Goldschagg, P , Ramutsindela, M , Bob, U , Khosa, M M
  • Date: 2003
  • Language: English
  • Type: Article
  • Identifier: vital:6678 , http://hdl.handle.net/10962/d1006659
  • Description: 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.
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Glasbury man made Clyro bells

  • Authors: Lewis, Colin A
  • Date: 2003
  • Language: English
  • Type: Article
  • Identifier: vital:6182 , http://hdl.handle.net/10962/d1012377
  • Description: [From Introduction] There must have been great excitement in Clyro in 1708. The existing four bells in St Michael's Church were recast by Henry Williams, the bell founder from Glasbury, into a ring of five bells. The work was apparently paid for by the owners of two of the great houses in the parish: Cabalva and Lloyney. Little is known of the four bells that existed in Clyro before Williams began his work, although they appear to have been larger than the five bells cast from their metal. The four bells swung side by side in a wooden frame in the tower of the church. This frame was altered in 1708 to accommodate bells of smaller dimensions and a fifth bell pit was added at right angles to the others. , Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
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Holding on or letting go?: the resolution of grief in relation to two Xhosa rituals in South Africa

Host-preference and density of woodrose-forming mistletoes (Loranthaceae) on savanna vegetation, South Africa

  • Authors: Dzerefos, Cathy M , Witkowski, Ed T F , Shackleton, Charlie M
  • Date: 2003
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/181487 , vital:43738 , xlink:href="https://doi.org/10.1023/A:1023991514968"
  • Description: In the Bushbuckridge region of South Africa host preference and density of two woodrose-forming mistletoes, Erianthemum dregei (Eckl. and Zeyh.) V. Tieghem and Pedistylis galpinii (Schinz ex Sprague) was quantified in relation to land-use (harvested or unharvested), rainfall (high, more than 660 or low , less than 660 mm year−1) and catenal position (top or lower slope). These two mistletoes are generalist hemi-parasites of savanna trees and shrubs occurring on 25 and 17 hosts respectively, seven of which are shared. Thirty-six percent of woody plant species recorded were found to be hosts. Although Sclerocarya birrea (A. Rich.) Hochst. comprised only 4% of woody plant density in the environment, it was the principal host for both mistletoes, accounting for 71% of total E. dregei and 42% of P. galpinii infection. Mistletoe infection relative to density of Ficus stuhlmanii, Trichilia emetica and Cassine transvaalensis indicated that these were preferential hosts to S. birrea. Mistletoe host preference was negatively correlated with host wood density. Mistletoe number per tree had a weak relationship to canopy size. Mistletoes of all size classes were denser at high rainfall relative to low rainfall sites. Interestingly, the overall mistletoe size class distribution was similar between harvested and unharvested sites. The ratio of living to dead mistletoe was 2 to 1 for E. dregei and 1.5 to 1 for P. galpinii. There are sufficient dead mistletoes in unharvested and harvested areas to satisfy present market demand. Living E. dregei predominated in harvested rather than unharvested areas suggesting that current-harvesting levels had little or no negative effect on the population. In contrast, P. galpinii was denser in unharvested areas possibly owing to its higher market value and thus higher harvesting levels.
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Hot-blooded singers: endothermy facilitates crepuscular signaling in African platypleurine cicadas (Hemiptera: Cicadidae: Platypleura spp.)

  • Authors: Sanborn, Allen F , Villet, Martin H , Phillips, Polly K F
  • Date: 2003
  • Language: English
  • Type: text , Article
  • Identifier: vital:6919 , http://hdl.handle.net/10962/d1011882
  • Description: The cicada genus Platypleura has a wide distribution across Africa and southern Asia. We describe endothermic thermoregulation in four South African species that show crepuscular signaling behavior. This is the first evidence of thermoregulation in platypleurine cicadas. Field measurements of body temperature (Tb) show that these animals regulate Tb through endogenous heat production. Maximum Tb measured was 22.1°C above ambient temperature during calling activity at dusk. The mean Tb during dusk activity did not differ from the mean Tb during diurnal activity. A unique behavior for cicadas, a temperature-dependent telescoping pulsation of the abdomen, was observed in the laboratory during endogenous warm-up. This behavior is part of a unique method of heat generation in endothermic cicadas. Males generally call from trunks and branches within the canopy and appear to use endothermy even when the sun is available to elevate Tb. Endothermy may provide the cicadas with the advantage of decreasing predation and acoustic competition by permitting calling from perches that most complement their cryptic coloration patterns and that ectotherms cannot use due to thermal constraints. In addition, endothermy may permit calling activity during crepuscular hours when atmospheric conditions are optimal for acoustic communication and predation risks are minimal.
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If you think that multi-media is not for Africa

  • Authors: Garman, Brian
  • Date: 2003
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/454723 , vital:75370 , https://hdl.handle.net/10520/EJC146246
  • Description: Over 20 years ago I sat myself down in front of the first Apple Mac to arrive in our department and far from being excited by it, I can remember thinking "this'll never catch on..."
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Implementing Location Services in the Location-Transparent, Distributed Environment of the Internet

  • Authors: Clayton, Peter G , Preston, Michael , Wells, George C
  • Date: 2003
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/430467 , vital:72693 , https://link.springer.com/book/10.1007/b13582?page=1#toc
  • Description: This volume contains the papers presented at the 5th International Workshop on Advanced Parallel Processing Technologies, APPT 2003. This series of workshops is designed to strengthen the cooperation between the German and Chinese institutions active in the area of these technologies. It has continued to grow, providing an excellent forum for reporting advances in parallel processing technologies. The 5th workshop itself addressed the entire gamut of related topics, ranging from the architectural aspects of parallel computer hardware and system software to the applied technologies for novel applica-tions. For this workshop, we received over 191 full submissions from researchers all over the world. All the papers were peer-reviewed in depth and qualitatively graded on their relevance, originality, signi?cance, presentation, and the overall appropriateness for their acceptance. Any concerns raised were discussed in the program com-mittee. The organizing committee did an excellent job in selecting 78 papers (Among them, 21 were short ones) for presentation. In short, the papers included here represent the forefront of research from China, Germany, and the other countries.
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