Analysis of the calling songs of Platypleura hirtipennis (Germar, 1834) and P. plumosa (Germar, 1834) (Hemiptera: Cicadidae)
- Sanborn, Allen F, Phillips, P K, Villet, Martin H
- Authors: Sanborn, Allen F , Phillips, P K , Villet, Martin H
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6896 , http://hdl.handle.net/10962/d1011656
- Description: [From the introduction]: Most male cicadas produce a calling song in order to attract conspecific females. These songs have been shown to differ in closely related species (e.g. Alexander & Moore 1962; Villet 1988, 1989; Boulard 1995; Marshall & Cooley 2000; Sanborn & Phillips 2001) and in species which share habitats (e.g. Sueur 2002). The former is an inevitable part of the divergence of recognition signals that characterizes the speciation process in animals using acoustic signals (Villet 1995), while the latter would be expected from a signal that acts as a reproductive isolating mechanism (Claridge 1985; Marshall & Cooley 2000). Calling songs are therefore of value in resolving taxonomic problems in the cicadas.
- Full Text:
- Date Issued: 2003
- Authors: Sanborn, Allen F , Phillips, P K , Villet, Martin H
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6896 , http://hdl.handle.net/10962/d1011656
- Description: [From the introduction]: Most male cicadas produce a calling song in order to attract conspecific females. These songs have been shown to differ in closely related species (e.g. Alexander & Moore 1962; Villet 1988, 1989; Boulard 1995; Marshall & Cooley 2000; Sanborn & Phillips 2001) and in species which share habitats (e.g. Sueur 2002). The former is an inevitable part of the divergence of recognition signals that characterizes the speciation process in animals using acoustic signals (Villet 1995), while the latter would be expected from a signal that acts as a reproductive isolating mechanism (Claridge 1985; Marshall & Cooley 2000). Calling songs are therefore of value in resolving taxonomic problems in the cicadas.
- Full Text:
- Date Issued: 2003
Implications of a new 40Ar/ 39Ar age for a basalt flow interbedded with the Etjo Formation, Northeast Namibia
- Marsh, Julian S, Swart, Roger S, Phillips, D
- Authors: Marsh, Julian S , Swart, Roger S , Phillips, D
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150364 , vital:38970 , https://doi.org/10.2113/106.4.281
- Description: A reliable 40Ar/39Ar plateau age of 180 ± 1.2 Ma (1σ) has been obtained for fresh basalt lava interbedded with aeolian Etjo Formation sandstones south-southwest of Grootfontein in northeast Namibia. This indicates that the Early Jurassic Karoo flood basalt sequence extended from Botswana into northeast Namibia at least as far as 18 east and that this may mark the eastern extent of the Early Cretaceous Etendeka Igneous Province.
- Full Text: false
- Date Issued: 2003
- Authors: Marsh, Julian S , Swart, Roger S , Phillips, D
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150364 , vital:38970 , https://doi.org/10.2113/106.4.281
- Description: A reliable 40Ar/39Ar plateau age of 180 ± 1.2 Ma (1σ) has been obtained for fresh basalt lava interbedded with aeolian Etjo Formation sandstones south-southwest of Grootfontein in northeast Namibia. This indicates that the Early Jurassic Karoo flood basalt sequence extended from Botswana into northeast Namibia at least as far as 18 east and that this may mark the eastern extent of the Early Cretaceous Etendeka Igneous Province.
- Full Text: false
- Date Issued: 2003
The inception phase of a case study of outcomes - based education assessment policy in the Human and Social Sciences Learning Area of C2005
- Authors: Wilmot, P Dianne
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6107 , http://hdl.handle.net/10962/d1009736
- Description: This article describes the Inception Phase (January to December 2002) of an ongoing research project focused on the Grade 9 Learning Area of Human and Social Sciences of Curriculum 2005. The case study involves a dynamic interaction between a university lecturer, playing the role of 'outside facilitator', and the History and Geography teachers at two independent schools. The article describes how teachers in a given context respond to outcomes-based education assessment policy, and the tools and processes they use to develop the deep understanding inferred by policy (Republic of South Africa, 2000) to implement change in a meaningful way. The article consists of three sections. The first contextualises significant events which foregrounded and provided the impetus for the research project. It provides an overview of the theory informing the research and the goals of the research. The second analyses in narrative form the various stages of the Inception Phase. It describes a process of curriculum development which has involved the development of criterion- referenced assessment rubrics, a Learner and Curriculum Profile, and an audit of current assessment practices in History and Geography at the two schools. The article illuminates the time and effort necessary for creative and systemic curriculum innovation. The final section synthesizes the information gathered.
- Full Text:
- Date Issued: 2003
- Authors: Wilmot, P Dianne
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6107 , http://hdl.handle.net/10962/d1009736
- Description: This article describes the Inception Phase (January to December 2002) of an ongoing research project focused on the Grade 9 Learning Area of Human and Social Sciences of Curriculum 2005. The case study involves a dynamic interaction between a university lecturer, playing the role of 'outside facilitator', and the History and Geography teachers at two independent schools. The article describes how teachers in a given context respond to outcomes-based education assessment policy, and the tools and processes they use to develop the deep understanding inferred by policy (Republic of South Africa, 2000) to implement change in a meaningful way. The article consists of three sections. The first contextualises significant events which foregrounded and provided the impetus for the research project. It provides an overview of the theory informing the research and the goals of the research. The second analyses in narrative form the various stages of the Inception Phase. It describes a process of curriculum development which has involved the development of criterion- referenced assessment rubrics, a Learner and Curriculum Profile, and an audit of current assessment practices in History and Geography at the two schools. The article illuminates the time and effort necessary for creative and systemic curriculum innovation. The final section synthesizes the information gathered.
- Full Text:
- Date Issued: 2003
The vegetation of the habitat of the Brenton blue butterfly, Orachrysops niobe (Trimen), in the Western Cape, South Africa
- Lubke, Roy, Hoare, D, Victor, J, Ketelaar, R
- Authors: Lubke, Roy , Hoare, D , Victor, J , Ketelaar, R
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6524 , http://hdl.handle.net/10962/d1005957
- Description: The Brenton blue butterfly is known only from a small population in one hectare of asteraceous coastal fynbos at Brenton-on-Sea. This fynbos is characterized by a great diversity of shrubs, herbs and graminoids, with a successional gradient to thicket where Pterocelastrus tricuspidatus is dominant. The eggs of the butterfly are laid on the lower side of the leaves of Indigofera erecta, on which the larvae feed. Fifteen 1-m² quadrats containing plants of Indigofera erecta with and without eggs of the butterfly were distinguished and sampled separately from 15 1-m² quadrats containing plants of Indigofera erecta without eggs. No marked differences in total vegetation, shrub or herb cover between the sites with and without eggs were observed. There was a difference in abundance of the fern Pteridium aquilinum, with over 30% cover at sites with no eggs and only about 6% at sites with eggs present. This could reflect the absence of other plants where the ferns had such dense cover.
- Full Text:
- Date Issued: 2003
- Authors: Lubke, Roy , Hoare, D , Victor, J , Ketelaar, R
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6524 , http://hdl.handle.net/10962/d1005957
- Description: The Brenton blue butterfly is known only from a small population in one hectare of asteraceous coastal fynbos at Brenton-on-Sea. This fynbos is characterized by a great diversity of shrubs, herbs and graminoids, with a successional gradient to thicket where Pterocelastrus tricuspidatus is dominant. The eggs of the butterfly are laid on the lower side of the leaves of Indigofera erecta, on which the larvae feed. Fifteen 1-m² quadrats containing plants of Indigofera erecta with and without eggs of the butterfly were distinguished and sampled separately from 15 1-m² quadrats containing plants of Indigofera erecta without eggs. No marked differences in total vegetation, shrub or herb cover between the sites with and without eggs were observed. There was a difference in abundance of the fern Pteridium aquilinum, with over 30% cover at sites with no eggs and only about 6% at sites with eggs present. This could reflect the absence of other plants where the ferns had such dense cover.
- Full Text:
- Date Issued: 2003
An email based issue-tracking workflow system that is extensible across organizational boundaries
- Kwinana, Z N, Wentworth, Peter N, Terzoli, Alfredo
- Authors: Kwinana, Z N , Wentworth, Peter N , Terzoli, Alfredo
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427517 , vital:72444 , https://www.researchgate.net/profile/Alfredo-Terzoli/publication/267848658_AN_EMAIL_BASED_ISSUE-TRACK-ING_WORKFLOW_SYSTEM_THAT_IS_EXTENSIBLE_ACROSS_ORGANIZATIONAL_BOUNDARIES/links/5523cb990cf2b351d9c338cb/AN-EMAIL-BASED-ISSUE-TRACKING-WORKFLOW-SYSTEM-THAT-IS-EXTENSIBLE-ACROSS-ORGANIZATIONAL-BOUNDARIES.pdf
- Description: There is a demand for improved communication and efficiency within the work place. As emails are generally used more than issue tracking systems, this paper will investigate a way of integrating the main fea-tures of email with those of an issue tracking system to ensure tasks are completed and if not information is provided to the relevant people at the relevant times. This will be done by creating an issue in an issue tracking system that is linkable to an email so as to track tasks that need to be done and follow the task through until completion.
- Full Text:
- Date Issued: 2004
- Authors: Kwinana, Z N , Wentworth, Peter N , Terzoli, Alfredo
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427517 , vital:72444 , https://www.researchgate.net/profile/Alfredo-Terzoli/publication/267848658_AN_EMAIL_BASED_ISSUE-TRACK-ING_WORKFLOW_SYSTEM_THAT_IS_EXTENSIBLE_ACROSS_ORGANIZATIONAL_BOUNDARIES/links/5523cb990cf2b351d9c338cb/AN-EMAIL-BASED-ISSUE-TRACKING-WORKFLOW-SYSTEM-THAT-IS-EXTENSIBLE-ACROSS-ORGANIZATIONAL-BOUNDARIES.pdf
- Description: There is a demand for improved communication and efficiency within the work place. As emails are generally used more than issue tracking systems, this paper will investigate a way of integrating the main fea-tures of email with those of an issue tracking system to ensure tasks are completed and if not information is provided to the relevant people at the relevant times. This will be done by creating an issue in an issue tracking system that is linkable to an email so as to track tasks that need to be done and follow the task through until completion.
- Full Text:
- Date Issued: 2004
Living with crime: Does crime affect victims' perceived quality of life?
- Authors: Moller, Valerie
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:21018 , http://hdl.handle.net/10962/6027 , http://dx.doi.org/10.17159/2413-3108/2004/v0i9a1032
- Description: Crime is thought to be a major concern that shapes the everyday lives of South Africans. But what impact does living with high levels of crime have on the mindset of ordinary citizens? A recent household crime victimisation study conducted in the Nelson Mandela Metropolitan Municipality provides tentative answers to this question.
- Full Text:
- Date Issued: 2004
- Authors: Moller, Valerie
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:21018 , http://hdl.handle.net/10962/6027 , http://dx.doi.org/10.17159/2413-3108/2004/v0i9a1032
- Description: Crime is thought to be a major concern that shapes the everyday lives of South Africans. But what impact does living with high levels of crime have on the mindset of ordinary citizens? A recent household crime victimisation study conducted in the Nelson Mandela Metropolitan Municipality provides tentative answers to this question.
- Full Text:
- Date Issued: 2004
One hundred years of botany at Rhodes University
- Authors: Lubke, Roy , Brink, Estelle
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6523 , http://hdl.handle.net/10962/d1005954
- Description: The Botany Department of Rhodes University is located in the historic Schonland Building. An indigenous garden was created in its courtyard, mainly of species of the Eastern Cape province, and its growth in diversity and stature mirrors the changes in the department over the years. Professor Selmar Schonland, the founding father of botany at Rhodes, was also the curator/director of the Albany Museum. Under his leadership, systematics was firmly established as a discipline at Rhodes and research on the flora of the Eastern Cape begun, to be continued to this day. Under professors William Isaac (1949–1951) and Edgar Twyman (1951–1973), plant physiology became an important area of study, and future leaders in physiology at other universities obtained degrees under them. Phycology and aquatic ecology became notable disciplines with Mary Pocock’s world-class work in the 1940s on freshwater and marine algae, which inspired others such as head of department Professor Stanley Seagrief (1958–1986) to develop these studies further. Mycology and microbiology were established as major subdisciplines under Noel Smith (1926–1948) and Twyman through to the 1960s, when the Department of Microbiology was established. Early studies in ecology owe their success to Tony Martin (1947–1956) and the link with the Grahamstown Botanical Research Station, when a sound base for plant ecology in the Eastern Cape was established. Coastal ecology became a major focus in the 1970s, when Roy Lubke and Ted Avis concentrated on dunes and the management of coastal regions. This led to the establishment of the Department of Environmental Science in the 1990s. The expertise of the botany staff in teaching and research in a variety of fields is reflected in the careers of its many students around the world.
- Full Text:
- Date Issued: 2004
- Authors: Lubke, Roy , Brink, Estelle
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6523 , http://hdl.handle.net/10962/d1005954
- Description: The Botany Department of Rhodes University is located in the historic Schonland Building. An indigenous garden was created in its courtyard, mainly of species of the Eastern Cape province, and its growth in diversity and stature mirrors the changes in the department over the years. Professor Selmar Schonland, the founding father of botany at Rhodes, was also the curator/director of the Albany Museum. Under his leadership, systematics was firmly established as a discipline at Rhodes and research on the flora of the Eastern Cape begun, to be continued to this day. Under professors William Isaac (1949–1951) and Edgar Twyman (1951–1973), plant physiology became an important area of study, and future leaders in physiology at other universities obtained degrees under them. Phycology and aquatic ecology became notable disciplines with Mary Pocock’s world-class work in the 1940s on freshwater and marine algae, which inspired others such as head of department Professor Stanley Seagrief (1958–1986) to develop these studies further. Mycology and microbiology were established as major subdisciplines under Noel Smith (1926–1948) and Twyman through to the 1960s, when the Department of Microbiology was established. Early studies in ecology owe their success to Tony Martin (1947–1956) and the link with the Grahamstown Botanical Research Station, when a sound base for plant ecology in the Eastern Cape was established. Coastal ecology became a major focus in the 1970s, when Roy Lubke and Ted Avis concentrated on dunes and the management of coastal regions. This led to the establishment of the Department of Environmental Science in the 1990s. The expertise of the botany staff in teaching and research in a variety of fields is reflected in the careers of its many students around the world.
- Full Text:
- Date Issued: 2004
Pollination biology of Bergeranthus multiceps (Aizoaceae) with preliminary observations of repeated flower opening and closure
- Peter, Craig I, Dold, Anthony P, Barker, Nigel P, Ripley, Bradley S
- Authors: Peter, Craig I , Dold, Anthony P , Barker, Nigel P , Ripley, Bradley S
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6529 , http://hdl.handle.net/10962/d1005970
- Description: Little is known about pollination of the Aizoaceae (Mesembryanthemaceae). There are sparse reports of generalist pollination in the family by a variety of insects (predominantly bees). Furthermore, most species are self-incompatible in cultivation. In this study, observations were made on two populations of Bergeranthus multiceps (Salm-Dyck) Schwantes growing in the Eastern Cape province of South Africa. Insects visiting the flowers were collected and examined for pollen. While 79 individual insects (in 24 genera representing 14 families and four orders) were collected visiting the flowers, the majority (43 individuals) were female Allodapula variegata bees (Apidae, subfamily Xylocopinae, tribe Allodapini)collecting pollen. All other bee visitors were also female, suggesting pollen collection as the primary activity at the flowers. The protandrous flowers were found to be self-incompatible, pointing to the importance of bee-mediated xenogamy in this species. The flowers of B. multiceps are bright yellow in the human visual spectrum. In addition, the petals of this species reflect ultraviolet light. In contrast, the yellow anthers absorb UV. Flower opening and closing is common in the Aizoaceae. Interestingly, in B. multiceps flowers open at about 15:30 and remain open for approximately three hours before closing again in the late afternoon. These afternoon flower opening events were found to be closely correlated to ambient temperatures above 23°C, relative humidity lower than 50% and vapour pressure deficit below 1.05 kPa measured from as early as 09:00 on the days when flowers opened.
- Full Text:
- Date Issued: 2004
- Authors: Peter, Craig I , Dold, Anthony P , Barker, Nigel P , Ripley, Bradley S
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6529 , http://hdl.handle.net/10962/d1005970
- Description: Little is known about pollination of the Aizoaceae (Mesembryanthemaceae). There are sparse reports of generalist pollination in the family by a variety of insects (predominantly bees). Furthermore, most species are self-incompatible in cultivation. In this study, observations were made on two populations of Bergeranthus multiceps (Salm-Dyck) Schwantes growing in the Eastern Cape province of South Africa. Insects visiting the flowers were collected and examined for pollen. While 79 individual insects (in 24 genera representing 14 families and four orders) were collected visiting the flowers, the majority (43 individuals) were female Allodapula variegata bees (Apidae, subfamily Xylocopinae, tribe Allodapini)collecting pollen. All other bee visitors were also female, suggesting pollen collection as the primary activity at the flowers. The protandrous flowers were found to be self-incompatible, pointing to the importance of bee-mediated xenogamy in this species. The flowers of B. multiceps are bright yellow in the human visual spectrum. In addition, the petals of this species reflect ultraviolet light. In contrast, the yellow anthers absorb UV. Flower opening and closing is common in the Aizoaceae. Interestingly, in B. multiceps flowers open at about 15:30 and remain open for approximately three hours before closing again in the late afternoon. These afternoon flower opening events were found to be closely correlated to ambient temperatures above 23°C, relative humidity lower than 50% and vapour pressure deficit below 1.05 kPa measured from as early as 09:00 on the days when flowers opened.
- Full Text:
- Date Issued: 2004
Ten years of marine natural products research at Rhodes University
- Davies-Coleman, Michael T, Beukes, Denzil R
- Authors: Davies-Coleman, Michael T , Beukes, Denzil R
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6568 , http://hdl.handle.net/10962/d1004131
- Description: Marine invertebrates, algae and microorganisms produce a plethora of structurally unique and biologically active secondary metabolites. The ecological roles of these natural products, although not completely understood, range from chemical defence against predation to intra-specific cues for larval settlement. Surprisingly, a number of these metabolites have also shown potential as new medicines for the treatment of a variety of diseases including cancer. The natural products chemistry of southern Africa’s unique marine flora and fauna is relatively unknown and this review provides an overview of the contribution made by the marine natural products research group at Rhodes University to the isolation, identification and synthesis of biologically active natural products from southern African marine microorganisms, algae, sponges, ascidians, soft corals and molluscs.
- Full Text:
- Date Issued: 2004
- Authors: Davies-Coleman, Michael T , Beukes, Denzil R
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6568 , http://hdl.handle.net/10962/d1004131
- Description: Marine invertebrates, algae and microorganisms produce a plethora of structurally unique and biologically active secondary metabolites. The ecological roles of these natural products, although not completely understood, range from chemical defence against predation to intra-specific cues for larval settlement. Surprisingly, a number of these metabolites have also shown potential as new medicines for the treatment of a variety of diseases including cancer. The natural products chemistry of southern Africa’s unique marine flora and fauna is relatively unknown and this review provides an overview of the contribution made by the marine natural products research group at Rhodes University to the isolation, identification and synthesis of biologically active natural products from southern African marine microorganisms, algae, sponges, ascidians, soft corals and molluscs.
- Full Text:
- Date Issued: 2004
The wing coupling apparatus and the morphometric analysis of honeybee populations
- Hepburn, H Randall, Radloff, Sarah E
- Authors: Hepburn, H Randall , Radloff, Sarah E
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:6904 , http://hdl.handle.net/10962/d1011760
- Description: Significant differences between countries were found in the distribution of the number of hamuli within Apis andreniformis, A. florea, A. cerana and A. koschevnikovi. The mean hamuli numbers for Apis mellifera intermissa differed significantly among localities in Algeria. Significant differences in intercolonial variability between countries were found within A. cerana. There was no significant infraspecific variability within A. andreniformis, A. florea, A. koschevnikovi and A. m. intermissa. Significant differences in the mean number of hamuli occur between A. m. intermissa and A. andreniformis, A. florea and A. cerana; also between A. cerana/A. koschevnikovi and A. andreniformis and A. florea. Significant differences were found in the distribution and variability of the number of hamuli between species (populations). The mean numbers of hamuli for A. andreniformis differed from those of A. florea. Both these population means differed from those of A. cerana, A. koschevnikovi and A. m. intermissa. No significant differences were found between A. cerana and A. koschevnikovi. When the analysis included data for A. dorsata, A. nigrocincta, A. m. carnica, A. m. caucasica and A. m. ligustica, the results showed significant differences in hamuli numbers between A. andreniformis/A. florea and A. cerana/A. koschevnikovi/A. nigrocincta and A. m. intermissa/A. m. carnica/A. m. caucasica/A. m. ligustica. Hamuli numbers in A. dorsata significantly differed from those of other populations except A. m. intermissa. These results show that hamuli numbers are useful in the classification of honeybee populations. Whether hamuli would be useful in multivariate analysis depends on the correlation between the number of hamuli and the other characters used.
- Full Text:
- Date Issued: 2004
- Authors: Hepburn, H Randall , Radloff, Sarah E
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:6904 , http://hdl.handle.net/10962/d1011760
- Description: Significant differences between countries were found in the distribution of the number of hamuli within Apis andreniformis, A. florea, A. cerana and A. koschevnikovi. The mean hamuli numbers for Apis mellifera intermissa differed significantly among localities in Algeria. Significant differences in intercolonial variability between countries were found within A. cerana. There was no significant infraspecific variability within A. andreniformis, A. florea, A. koschevnikovi and A. m. intermissa. Significant differences in the mean number of hamuli occur between A. m. intermissa and A. andreniformis, A. florea and A. cerana; also between A. cerana/A. koschevnikovi and A. andreniformis and A. florea. Significant differences were found in the distribution and variability of the number of hamuli between species (populations). The mean numbers of hamuli for A. andreniformis differed from those of A. florea. Both these population means differed from those of A. cerana, A. koschevnikovi and A. m. intermissa. No significant differences were found between A. cerana and A. koschevnikovi. When the analysis included data for A. dorsata, A. nigrocincta, A. m. carnica, A. m. caucasica and A. m. ligustica, the results showed significant differences in hamuli numbers between A. andreniformis/A. florea and A. cerana/A. koschevnikovi/A. nigrocincta and A. m. intermissa/A. m. carnica/A. m. caucasica/A. m. ligustica. Hamuli numbers in A. dorsata significantly differed from those of other populations except A. m. intermissa. These results show that hamuli numbers are useful in the classification of honeybee populations. Whether hamuli would be useful in multivariate analysis depends on the correlation between the number of hamuli and the other characters used.
- Full Text:
- Date Issued: 2004
A.k.a. Breyten Breytenbach : critical approaches to his writings and paintings, J.L. Coullie and J.U. Jacobs, eds. : book review
- Authors: Vorster, A F
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6335 , http://hdl.handle.net/10962/d1012399
- Description: a.k.a. Breyten Breytenbach brings together a collection of 14 essays by 12 scholars on the work of this remarkable South African writer, poet and painter. Designating Breytenbach as ‘South African’ is, of course, already a highly contentious act. It relates directly to the central concern of this volume (and one of the central concerns of Breytenbach’s work), namely the question of identity. The title characterises the artist’s proper name as but one in a series of constantly shifting and interchanging personas adopted in his art (and in his life, e.g. when working underground in the 1970s to contribute to the overthrow of the apartheid regime). The painting on the cover further explores the theme of the mask, with the white male figure’s face covered by a book-like object (although his eyes are partially visible through the object), and the presence of a burning hat floating in the air next to him serves as an additional link with many of his other paintings where headgear is associated with shifting identities, as pointed out by Marilet Sienaert in her essay, “The I of the Beholder: Identity and Place in the Art and Writing.” Like several of the other authors, Sienaert places great emphasis on the notion of movement or transformation as critical to Breytenbach’s thinking and creative practice. It is virtually unavoidable, given his background, that he should grapple with “the contemporary notion of ‘home’ being both everywhere and nowhere”, and that travel and nomadism should have become two of the most prominent themes in his poetry as well as his prose. Identity and creativity are both dependent upon the ability to constantly renew oneself and to “keep moving”.
- Full Text:
- Date Issued: 2005
- Authors: Vorster, A F
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6335 , http://hdl.handle.net/10962/d1012399
- Description: a.k.a. Breyten Breytenbach brings together a collection of 14 essays by 12 scholars on the work of this remarkable South African writer, poet and painter. Designating Breytenbach as ‘South African’ is, of course, already a highly contentious act. It relates directly to the central concern of this volume (and one of the central concerns of Breytenbach’s work), namely the question of identity. The title characterises the artist’s proper name as but one in a series of constantly shifting and interchanging personas adopted in his art (and in his life, e.g. when working underground in the 1970s to contribute to the overthrow of the apartheid regime). The painting on the cover further explores the theme of the mask, with the white male figure’s face covered by a book-like object (although his eyes are partially visible through the object), and the presence of a burning hat floating in the air next to him serves as an additional link with many of his other paintings where headgear is associated with shifting identities, as pointed out by Marilet Sienaert in her essay, “The I of the Beholder: Identity and Place in the Art and Writing.” Like several of the other authors, Sienaert places great emphasis on the notion of movement or transformation as critical to Breytenbach’s thinking and creative practice. It is virtually unavoidable, given his background, that he should grapple with “the contemporary notion of ‘home’ being both everywhere and nowhere”, and that travel and nomadism should have become two of the most prominent themes in his poetry as well as his prose. Identity and creativity are both dependent upon the ability to constantly renew oneself and to “keep moving”.
- Full Text:
- Date Issued: 2005
African herbal medicines in the treatment of HIV: Hypoxis and Sutherlandia: an overview of evidence and pharmacology
- Mills, Edward, Cooper, Curtis, Seely, Dugald, Kanfer, Isadore
- Authors: Mills, Edward , Cooper, Curtis , Seely, Dugald , Kanfer, Isadore
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6401 , http://hdl.handle.net/10962/d1006337
- Description: In Africa, herbal medicines are often used as primary treatment for HIV/AIDS and for HIV-related problems. In general, traditional medicines are not well researched, and are poorly regulated. We review the evidence and safety concerns related to the use of two specific African herbals, which are currently recommended by the Ministry of Health in South Africa and member states for use in HIV: African Potato and Sutherlandia. We review the pharmacology, toxicology and pharmacokinetics of these herbal medicines. Despite the popularity of their use and the support of Ministries of Health and NGOs in some African countries, no clinical trials of efficacy exist, and low-level evidence of harm identifies the potential for drug interactions with antiretroviral drugs. Efforts should be made by mainstream health professionals to provide validated information to traditional healers and patients on the judicious use of herbal remedies. This may reduce harm through failed expectations, pharmacologic adverse events including possible drug/herb interactions and unnecessary added therapeutic costs. Efforts should also be directed at evaluating the possible benefits of natural products in HIV/AIDS treatment.
- Full Text:
- Date Issued: 2005
- Authors: Mills, Edward , Cooper, Curtis , Seely, Dugald , Kanfer, Isadore
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6401 , http://hdl.handle.net/10962/d1006337
- Description: In Africa, herbal medicines are often used as primary treatment for HIV/AIDS and for HIV-related problems. In general, traditional medicines are not well researched, and are poorly regulated. We review the evidence and safety concerns related to the use of two specific African herbals, which are currently recommended by the Ministry of Health in South Africa and member states for use in HIV: African Potato and Sutherlandia. We review the pharmacology, toxicology and pharmacokinetics of these herbal medicines. Despite the popularity of their use and the support of Ministries of Health and NGOs in some African countries, no clinical trials of efficacy exist, and low-level evidence of harm identifies the potential for drug interactions with antiretroviral drugs. Efforts should be made by mainstream health professionals to provide validated information to traditional healers and patients on the judicious use of herbal remedies. This may reduce harm through failed expectations, pharmacologic adverse events including possible drug/herb interactions and unnecessary added therapeutic costs. Efforts should also be directed at evaluating the possible benefits of natural products in HIV/AIDS treatment.
- Full Text:
- Date Issued: 2005
Biological removal of nitrogen species from metal-processing wastewater
- Kasia, J M, Duncan, J R, Burgess, Jo E
- Authors: Kasia, J M , Duncan, J R , Burgess, Jo E
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6482 , http://hdl.handle.net/10962/d1006256
- Description: Although several nitrification/denitrification processes are established for the removal of ammonia and nitrate from municipal and industrial wastewaters, there are few reported results on the removal of these ions from metal-processing and finishing wastewaters. Unlike municipal wastewater, there is very little organic content in metal-processing wastewaters. Sources of ammonia and nitrate in the wastewater include the use of ammonium-nitrate-fuel oil as a blasting agent, and the use of other nitrogen-containing reagents during processing. The objective of this work was to investigate a biological process for the removal of nitrogenous compounds from real metal-processing wastewater. The system comprised an aerobic continuously stirred tank reactor (CSTR) followed by an anaerobic packed column and was run using real wastewater from a metal-processing operation. The system was inoculated using humus sludge from a municipal trickling filter and a period of approximately four weeks was required for a denitrifying biofilm to develop. Results showed that ammonia removal occurred readily in the CSTR while nitrite oxidation was slower to develop. The CSTR was found to be suitable for ammonia oxidation; up to 89% ammonia removal was achieved. By employing an integrated process comprising nitrification and denitrification, high ammonia removal efficiencies can be obtained. An effluent that is low in ammonia can be obtained with this system with additional carbon introduced after the CSTR. The gravel-packed column reactor was found to be unsuitable for the removal of nitrate in the configuration used (maximum 15% removal efficiency). The critical parameters for denitrification are nitrate concentration, temperature, influent flow rate and mean cell retention time. Nitrate removal did not meet the expectations projected by previous authors' work using synthetic wastewater.
- Full Text:
- Date Issued: 2005
- Authors: Kasia, J M , Duncan, J R , Burgess, Jo E
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6482 , http://hdl.handle.net/10962/d1006256
- Description: Although several nitrification/denitrification processes are established for the removal of ammonia and nitrate from municipal and industrial wastewaters, there are few reported results on the removal of these ions from metal-processing and finishing wastewaters. Unlike municipal wastewater, there is very little organic content in metal-processing wastewaters. Sources of ammonia and nitrate in the wastewater include the use of ammonium-nitrate-fuel oil as a blasting agent, and the use of other nitrogen-containing reagents during processing. The objective of this work was to investigate a biological process for the removal of nitrogenous compounds from real metal-processing wastewater. The system comprised an aerobic continuously stirred tank reactor (CSTR) followed by an anaerobic packed column and was run using real wastewater from a metal-processing operation. The system was inoculated using humus sludge from a municipal trickling filter and a period of approximately four weeks was required for a denitrifying biofilm to develop. Results showed that ammonia removal occurred readily in the CSTR while nitrite oxidation was slower to develop. The CSTR was found to be suitable for ammonia oxidation; up to 89% ammonia removal was achieved. By employing an integrated process comprising nitrification and denitrification, high ammonia removal efficiencies can be obtained. An effluent that is low in ammonia can be obtained with this system with additional carbon introduced after the CSTR. The gravel-packed column reactor was found to be unsuitable for the removal of nitrate in the configuration used (maximum 15% removal efficiency). The critical parameters for denitrification are nitrate concentration, temperature, influent flow rate and mean cell retention time. Nitrate removal did not meet the expectations projected by previous authors' work using synthetic wastewater.
- Full Text:
- Date Issued: 2005
Fire behaviour in a semi-arid Baikiaea plurijuga savanna woodland on Kalahari sands in western Zimbabwe
- Gambiza, James, Campbell, Bruce M, Moe, Stein R
- Authors: Gambiza, James , Campbell, Bruce M , Moe, Stein R
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6630 , http://hdl.handle.net/10962/d1006822
- Description: Human-induced fires are a major disturbance in Baikiaea plurijuga woodland savannas that are economically important for timber production. Most fires occur during the late dry season, when they may severely damage woody plants. Prescribed burning during the early dry season is a management strategy to reduce fuel loads and thus the incidence of intense fires during the late dry season. There is, however, little information on fire behaviour characteristics of early dry season fires.We studied the relationship between experimental fuel conditions and fire behaviour by lighting 15 fires during the early dry season in a Baikiaea woodland. Fire intensity ranged from 25 to 1341 kW m[superscript (-1)], while rate of spread of fire varied between 0.01 and 0.35ms[superscript (-1)]. Fire intensity and rate of spread were positively related to flame height, leaf-scorch height and proportion of the area burnt. The relationships suggest that fire characteristics can be retrospectively determined using a variable such as scorch height. The grass fuel load, wind speed, relative humidity and to a lesser extent fuel moisture were important predictors of rate of spread, flame height, leaf-scorch height and proportion of the area burnt, with no impact due to the litter fuel load. The grass fuel load and wind speed had a positive effect on rate of spread, whereas relative humidity and fuel moisture had a negative effect. These findings indicate that managers can predict the likely damage to woody plants during an early dry season burn by assessing the grass fuel load and weather conditions at the time of burning.
- Full Text:
- Date Issued: 2005
- Authors: Gambiza, James , Campbell, Bruce M , Moe, Stein R
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6630 , http://hdl.handle.net/10962/d1006822
- Description: Human-induced fires are a major disturbance in Baikiaea plurijuga woodland savannas that are economically important for timber production. Most fires occur during the late dry season, when they may severely damage woody plants. Prescribed burning during the early dry season is a management strategy to reduce fuel loads and thus the incidence of intense fires during the late dry season. There is, however, little information on fire behaviour characteristics of early dry season fires.We studied the relationship between experimental fuel conditions and fire behaviour by lighting 15 fires during the early dry season in a Baikiaea woodland. Fire intensity ranged from 25 to 1341 kW m[superscript (-1)], while rate of spread of fire varied between 0.01 and 0.35ms[superscript (-1)]. Fire intensity and rate of spread were positively related to flame height, leaf-scorch height and proportion of the area burnt. The relationships suggest that fire characteristics can be retrospectively determined using a variable such as scorch height. The grass fuel load, wind speed, relative humidity and to a lesser extent fuel moisture were important predictors of rate of spread, flame height, leaf-scorch height and proportion of the area burnt, with no impact due to the litter fuel load. The grass fuel load and wind speed had a positive effect on rate of spread, whereas relative humidity and fuel moisture had a negative effect. These findings indicate that managers can predict the likely damage to woody plants during an early dry season burn by assessing the grass fuel load and weather conditions at the time of burning.
- Full Text:
- Date Issued: 2005
Reflections on the ‘3rd World Environmental Education Congress: Educational pathways towards sustainability’, Italy, 2005
- Authors: Lotz-Sisitka, Heila
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6096 , http://hdl.handle.net/10962/d1008619
- Description: Conference Theme: The congress theme ‘Educational pathways towards sustainability’ foregrounded the current ‘state of play’ in environmental education / education for sustainability, at the start of the UN Decade of Education for Sustainable Development (DESD), and drew attention to the role of education in creating pathways towards sustainability. Mario Solomone, convenor of the congress, in his orientation to the congress describes the congress as being about ‘cultural changes and cultural forces for change’, highlighting the role of education, training and communication in redirecting values, knowledge and behaviour to construct a human society ‘that is fairer and more aware of the equilibrium of a beautiful and fragile planet’ (Salomone, 2005: 6). To facilitate deliberations during the conference a set of interrelated themes were established which included: communication and the environment; paths to sustainability; research and assessment in environmental education; sustainable education; training the trainers; community awareness; promoting participation and governance and creating a network; economics and ecology; environment and health; farming and related issues; ethics; and emotional involvements. These congress themes, together with an impressive array of keynote papers kept congress participants actively engaged with the question of the DESD.
- Full Text:
- Date Issued: 2005
- Authors: Lotz-Sisitka, Heila
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6096 , http://hdl.handle.net/10962/d1008619
- Description: Conference Theme: The congress theme ‘Educational pathways towards sustainability’ foregrounded the current ‘state of play’ in environmental education / education for sustainability, at the start of the UN Decade of Education for Sustainable Development (DESD), and drew attention to the role of education in creating pathways towards sustainability. Mario Solomone, convenor of the congress, in his orientation to the congress describes the congress as being about ‘cultural changes and cultural forces for change’, highlighting the role of education, training and communication in redirecting values, knowledge and behaviour to construct a human society ‘that is fairer and more aware of the equilibrium of a beautiful and fragile planet’ (Salomone, 2005: 6). To facilitate deliberations during the conference a set of interrelated themes were established which included: communication and the environment; paths to sustainability; research and assessment in environmental education; sustainable education; training the trainers; community awareness; promoting participation and governance and creating a network; economics and ecology; environment and health; farming and related issues; ethics; and emotional involvements. These congress themes, together with an impressive array of keynote papers kept congress participants actively engaged with the question of the DESD.
- Full Text:
- Date Issued: 2005
Situated culture, ethics and new learning theory: emerging perspectives in environmental education research
- Authors: Lotz-Sisitka, Heila
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6095 , http://hdl.handle.net/10962/d1008617
- Description: Celebrating the 8th International Invitational Research and Development Seminar. This edition of the EEASA Journal celebrates the hosting of the 8th International Invitational Research and Development Seminar on Environmental and Health Education in South Africa in March 2005. The International Invitational Research and Development Seminars are ‘special events’ in the field of environmental and health education research. They are characterised by their democratic, deliberative nature, and by their intent to scope innovation and methodological issues. First established some years ago in Copenhagen, Denmark, these seminars have provided an evolving international forum for researchers interested in research methodology to meet and frame new themes, trends and issues arising in the field of environmental education and health education research.
- Full Text:
- Date Issued: 2005
- Authors: Lotz-Sisitka, Heila
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6095 , http://hdl.handle.net/10962/d1008617
- Description: Celebrating the 8th International Invitational Research and Development Seminar. This edition of the EEASA Journal celebrates the hosting of the 8th International Invitational Research and Development Seminar on Environmental and Health Education in South Africa in March 2005. The International Invitational Research and Development Seminars are ‘special events’ in the field of environmental and health education research. They are characterised by their democratic, deliberative nature, and by their intent to scope innovation and methodological issues. First established some years ago in Copenhagen, Denmark, these seminars have provided an evolving international forum for researchers interested in research methodology to meet and frame new themes, trends and issues arising in the field of environmental education and health education research.
- Full Text:
- Date Issued: 2005
A Discussion Of Wireless Security Technologies
- Janse van Rensburg, Johanna, Irwin, Barry V W
- Authors: Janse van Rensburg, Johanna , Irwin, Barry V W
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429852 , vital:72645 , https://www.researchgate.net/profile/Barry-Ir-win/publication/228864029_A_DISCUSSION_OF_WIRELESS_SECURITY_TECHNOLOGIES/links/53e9c5190cf28f342f41492b/A-DISCUSSION-OF-WIRELESS-SECURITY-TECHNOLOGIES.pdf
- Description: The 802.11 standard contains a number of problems, ranging from in-terference, co-existence issues, exposed terminal problems and regula-tions to security. Despite all of these it has become a widely deployed technology as an extension of companies’ networks to provide mobility. In this paper the focus will be on the security issues of 802.11. Several solutions for the deployment of 802.11 security exists today, ranging from WEP, WPA, VPN and 802.11 i, each providing a different level of security. These technologies contain pros and cons which need to be understood in order to implement an appropriate solution suited to a specific scenario.
- Full Text:
- Date Issued: 2006
- Authors: Janse van Rensburg, Johanna , Irwin, Barry V W
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429852 , vital:72645 , https://www.researchgate.net/profile/Barry-Ir-win/publication/228864029_A_DISCUSSION_OF_WIRELESS_SECURITY_TECHNOLOGIES/links/53e9c5190cf28f342f41492b/A-DISCUSSION-OF-WIRELESS-SECURITY-TECHNOLOGIES.pdf
- Description: The 802.11 standard contains a number of problems, ranging from in-terference, co-existence issues, exposed terminal problems and regula-tions to security. Despite all of these it has become a widely deployed technology as an extension of companies’ networks to provide mobility. In this paper the focus will be on the security issues of 802.11. Several solutions for the deployment of 802.11 security exists today, ranging from WEP, WPA, VPN and 802.11 i, each providing a different level of security. These technologies contain pros and cons which need to be understood in order to implement an appropriate solution suited to a specific scenario.
- Full Text:
- Date Issued: 2006
Alternative media: a viable option for Southern Africa?
- Authors: Banda, Fackson
- Date: 2006
- Language: English
- Type: text , article
- Identifier: vital:6328 , http://hdl.handle.net/10962/d1008473 , https://core.ac.uk/download/pdf/145046852.pdf
- Description: preprint , The article attempts a historically and culturally based definition of alternative media. It then gives some case studies to illustrate the efficacy of such media forms, apart from highlighting the problems associated with them. It concludes that alternative media emerge to deal with specific ideological projects and, as such, must be viewed as satisfying a specific need at a specific point in time.
- Full Text:
- Date Issued: 2006
- Authors: Banda, Fackson
- Date: 2006
- Language: English
- Type: text , article
- Identifier: vital:6328 , http://hdl.handle.net/10962/d1008473 , https://core.ac.uk/download/pdf/145046852.pdf
- Description: preprint , The article attempts a historically and culturally based definition of alternative media. It then gives some case studies to illustrate the efficacy of such media forms, apart from highlighting the problems associated with them. It concludes that alternative media emerge to deal with specific ideological projects and, as such, must be viewed as satisfying a specific need at a specific point in time.
- Full Text:
- Date Issued: 2006
Ameliorating poverty in South Africa through natural resource commercialisation
- Authors: Shackleton, Sheona E
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6651 , http://hdl.handle.net/10962/d1007062
- Description: This short policy brief advocates for more attention to be paid to the potential of natural resource commercialisation as a means to livelihood security and poverty alleviation in rural South Africa. It is one of a set of four policy briefs based on the findings of several case studies across the country.
- Full Text:
- Date Issued: 2006
- Authors: Shackleton, Sheona E
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6651 , http://hdl.handle.net/10962/d1007062
- Description: This short policy brief advocates for more attention to be paid to the potential of natural resource commercialisation as a means to livelihood security and poverty alleviation in rural South Africa. It is one of a set of four policy briefs based on the findings of several case studies across the country.
- Full Text:
- Date Issued: 2006
Cellulases (CMCases) and polyphenol oxidases from thermophilic Bacillus spp
- Mayende, Lungisa, Wilhelmi, Brendan S, Pletschke, Brett I
- Authors: Mayende, Lungisa , Wilhelmi, Brendan S , Pletschke, Brett I
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6462 , http://hdl.handle.net/10962/d1005791 , http://dx.doi.org/10.1016/j.soilbio.2006.03.019
- Description: In composting, organic matter is degraded by cellulases and ligninolytic enzymes at temperatures typically above 50 °C. This study isolated thermophilic microorganisms from a compost system that were then screened for cellulase and polyphenol oxidase activity. Temperature optima for the cellulases and polyphenol oxidases were determined as 70 and 40 °C, respectively. Maximal cellulase activity was determined as 1.333 mg glucose released ml[superscript −1] min[superscript −1]. Maximal polyphenol oxidase activity attained was 5.111 nmol phenol ml[superscript −1] min[superscript −1]. Cellulases were found to be stable over a period of 1 h. The isolated compost microorganisms were identified as strains of Bacillus using 16S ribosomal DNA sequence analysis.
- Full Text:
- Date Issued: 2006
- Authors: Mayende, Lungisa , Wilhelmi, Brendan S , Pletschke, Brett I
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6462 , http://hdl.handle.net/10962/d1005791 , http://dx.doi.org/10.1016/j.soilbio.2006.03.019
- Description: In composting, organic matter is degraded by cellulases and ligninolytic enzymes at temperatures typically above 50 °C. This study isolated thermophilic microorganisms from a compost system that were then screened for cellulase and polyphenol oxidase activity. Temperature optima for the cellulases and polyphenol oxidases were determined as 70 and 40 °C, respectively. Maximal cellulase activity was determined as 1.333 mg glucose released ml[superscript −1] min[superscript −1]. Maximal polyphenol oxidase activity attained was 5.111 nmol phenol ml[superscript −1] min[superscript −1]. Cellulases were found to be stable over a period of 1 h. The isolated compost microorganisms were identified as strains of Bacillus using 16S ribosomal DNA sequence analysis.
- Full Text:
- Date Issued: 2006