Ziguehi
- Authors: Gnaore Djimi (vocals, creator) , Gnaore Djimi The Best (album title) , Showbiz
- Date: 2000
- Subjects: Popular music , Popular music--Africa, West , Africa Cote d'Ivoire Abidjan f-iv
- Language: French
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/128897 , vital:36188 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC17-02
- Description: Ivorian popular song in the Polihet style that is based on the traditional sounds, gestures and heritage of Niamboua people who live in the southwest reagion of Cote d'Ivoire. Polihet is performed at funerals, baptisms,weddings with the themes of love, hate, death and peace
- Full Text: false
- Date Issued: 2000
Koussougro-Sery
- Authors: Gnaore Djimi (vocals, creator) , Gnaore Djimi The Best (album title) , Showbiz
- Date: 2000
- Subjects: Popular music , Popular music--Africa, West , Africa Cote d'Ivoire Abidjan f-iv
- Language: French
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/129005 , vital:36202 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC17-08
- Description: Ivorian popular song in the Polihet style that is based on the traditional sounds, gestures and heritage of Niamboua people who live in the southwest reagion of Cote d'Ivoire. Polihet is performed at funerals, baptisms,weddings with the themes of love, hate, death and peace
- Full Text: false
- Date Issued: 2000
Kpihi-Gou
- Authors: Gnaore Djimi (vocals, creator) , Gnaore Djimi The Best (album title) , Showbiz
- Date: 2000
- Subjects: Popular music , Popular music--Africa, West , Africa Cote d'Ivoire Abidjan f-iv
- Language: French
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/129021 , vital:36205 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC17-10
- Description: Ivorian popular song in the Polihet style that is based on the traditional sounds, gestures and heritage of Niamboua people who live in the southwest reagion of Cote d'Ivoire. Polihet is performed at funerals, baptisms,weddings with the themes of love, hate, death and peace
- Full Text: false
- Date Issued: 2000
Zougo
- Authors: Gnaore Djimi (vocals, creator) , Gnaore Djimi The Best (album title) , Showbiz
- Date: 2000
- Subjects: Popular music , Popular music--Africa, West , Africa Cote d'Ivoire Abidjan f-iv
- Language: French
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/128960 , vital:36197 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC17-05
- Description: Ivorian popular song in the Polihet style that is based on the traditional sounds, gestures and heritage of Niamboua people who live in the southwest reagion of Cote d'Ivoire. Polihet is performed at funerals, baptisms,weddings with the themes of love, hate, death and peace
- Full Text: false
- Date Issued: 2000
Zahi
- Authors: Gnaore Djimi (vocals, creator) , Gnaore Djimi The Best (album title) , Showbiz
- Date: 2000
- Subjects: Popular music , Popular music--Africa, West , Africa Cote d'Ivoire Abidjan f-iv
- Language: French
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/128889 , vital:36187 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC17-01
- Description: Ivorian popular song in the Polihet style that is based on the traditional sounds, gestures and heritage of Niamboua people who live in the southwest reagion of Cote d'Ivoire. Polihet is performed at funerals, baptisms,weddings with the themes of love, hate, death and peace
- Full Text: false
- Date Issued: 2000
Nouveau II
- Authors: Gnaore Djimi (vocals, creator) , Gnaore Djimi The Best (album title) , Showbiz
- Date: 2000
- Subjects: Popular music , Popular music--Africa, West , Africa Cote d'Ivoire Abidjan f-iv
- Language: French
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/128992 , vital:36201 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC17-07
- Description: Ivorian popular song in the Polihet style that is based on the traditional sounds, gestures and heritage of Niamboua people who live in the southwest reagion of Cote d'Ivoire. Polihet is performed at funerals, baptisms,weddings with the themes of love, hate, death and peace
- Full Text: false
- Date Issued: 2000
Bidi Djehoua
- Authors: Gnaore Djimi (vocals, creator) , Gnaore Djimi The Best (album title) , Showbiz
- Date: 2000
- Subjects: Popular music , Popular music--Africa, West , Africa Cote d'Ivoire Abidjan f-iv
- Language: French
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/129014 , vital:36204 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC17-09
- Description: Ivorian popular song in the Polihet style that is based on the traditional sounds, gestures and heritage of Niamboua people who live in the southwest reagion of Cote d'Ivoire. Polihet is performed at funerals, baptisms,weddings with the themes of love, hate, death and peace
- Full Text: false
- Date Issued: 2000
Dissahouan
- Authors: Gnaore Djimi (vocals, creator) , Gnaore Djimi The Best (album title) , Showbiz
- Date: 2000
- Subjects: Popular music , Popular music--Africa, West , Africa Cote d'Ivoire Abidjan f-iv
- Language: French
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/128987 , vital:36200 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC17-06
- Description: Ivorian popular song in the Polihet style that is based on the traditional sounds, gestures and heritage of Niamboua people who live in the southwest reagion of Cote d'Ivoire. Polihet is performed at funerals, baptisms,weddings with the themes of love, hate, death and peace
- Full Text: false
- Date Issued: 2000
Nyau masquerade performance : shifting the imperial gaze
- Authors: Guhrs, Tamara
- Date: 2000
- Subjects: Masquerades -- Malawi , Masquerades -- Zambia , Malawi -- Religion , Zambia -- Religion , Masks, Chewa , Chewa (African people) -- Rites and ceremonies , Nyanja (African people) -- Rites and ceremonies , Secret societies -- Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2140 , http://hdl.handle.net/10962/d1002372 , Masquerades -- Malawi , Masquerades -- Zambia , Malawi -- Religion , Zambia -- Religion , Masks, Chewa , Chewa (African people) -- Rites and ceremonies , Nyanja (African people) -- Rites and ceremonies , Secret societies -- Africa
- Description: Nyau Masquerades have been studied by missionaries, anthropologists and religious specialists, but have seldom been documented by theatre and performance specialists. This dissertation argues for the acceptance of Ny au performance as a contemporary world theatre form rooted in tradition. Charting the uneasy relationship between the Nyau and those who have sought to record their performances, the author delineates a vivid dramaturgy of this art form. In doing so, the boundaries of what define theatre as it has traditionally been understood in dominant discourses are made more fluid. Nyau performances have been affected by Colonial processes in varied ways. They were banned by the former government of Northern Rhodesia and severely censored by Catholic Mission teachings in the former Nyasaland. Other forms of vilification have been more subtle. Information about performance in Africa has often been collected and arranged in ways which limit the understanding of these genres. Images of Africa which cluster around the notion of the 'Primitive Other' have enabled a representation of Ny au masking as a superstitious and outdated practice with no relevance for contemporary Africa. This work calls for a new examination of the Nyau, through the lens of local discourse as well as contemporary global understandings of performance. Chapter One examines the issue of primitivism and the ways in which Africa has historically been posited as the exotic Other to Europe. Chapter Two examines the Nyau ih terms of specific dramaturgical elements, adjusting previous misconceptions surrounding the theatr~ forms of Chewa and Nyanja people. Chapter Three is devoted to a discussion of space in ritual theatre and Nyau performance, while Chapter Four explores masking and questions of transformation and liminality. In conclusion, it is seen that the use of the mask is a metaphor for the suspension of rigid boundaries separating subject/object, self/other, ritual/theatre, a suspension which needs to take place before an enriched understanding of performance in Africa can be reached.
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- Date Issued: 2000
Feeding biology of three euphausiid species in the vicinity of the Prince Edward Archipelago (Southern Ocean)
- Authors: Gurney, Leigh Josephine
- Date: 2000
- Subjects: Euphausiacea , Euphausiacea -- Feeding and feeds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5695 , http://hdl.handle.net/10962/d1005381 , Euphausiacea , Euphausiacea -- Feeding and feeds
- Description: The feeding biology of three euphausiid species, Euphausia vallentini (adults and juveniles), E. longirostris and Nematoscelis megalops was investigated during austral autumn (April/May) of 1998 and 1999, in the vicinity of the Prince Edward Islands (Southern Ocean). Data on the abundance and biomass of these species, estimated from bongo net tows, were investigated. Trophic position was assessed using gut contents and stable nitrogen isotope measurements. Feeding rate and daily carbon ration were estimated using the gut fluorescence and the gut fullness techniques. Vertical migrations into the surface waters at night were found to be strong for Euphausia vallentini adults and juveniles. Associated with these migrations were clear diel feeding patterns. Insufficient data during daylight hours for E. longirostris made it impossible to determine diel feeding patterns, but high feeding activity did occur during dark hours. Nematoscelis megalops did not show any distinct diel feeding pattern, but slightly higher gut fullness indices in the late afternoon suggested that feeding activity may have been highest during this period. For both Euphausia spp. high gut pigment levels were recorded in 1999, which corresponded to higher ambient chlorophyll a concentrations for that year. Highest initial gut pigment levels and highest ingestion rates were found for Euphausia longirostris in both years and lowest values were observed for N. megalops. High phytoplankton and low metazoan contributions to the diet of Euphausia vallentini juveniles, as shown in the gut content analysis, and low stable nitrogen isotope ratios (ð¹⁵N = 1.39±0.31), both indicated that this group was principally herbivorous. The results of gut content analysis of the adults of E. vallentini were similar to those of the juveniles, however, stable nitrogen isotope results showed that there was a higher degree of omnivory (ð¹⁵N = 3.81±0.66). Daily ration estimates from the gut fluorescence and fullness techniques showed that between 3.3 and 25.7 % of E. vallentini adults total daily carbon ration was derived from autotrophic sources. Although the contribution of carnivory to the diet was difficult to determine, the adults of this species may be considered omnivorous. Irrespective of the degree of carnivory, a dietry shift with an increase in size was evident for this species. Gut content analysis for Euphausia longirostris showed that this species consumed large amounts of both phytoplankton and metazoan prey and this was reflected in the stable nitrogen isotope results (ð¹⁵N = 6.88±0.60). These findings were supported by the results of the daily carbon ration estimates which showed that autotrophic carbon contributed between 6.9 and 20.3 % of the daily carbon consumption. The gut content analysis suggested that N. megalops was omnivorous, and the stable nitrogen isotope results place it in a trophic position equivalent to that of E. longirostris (ð¹⁵N = 6.83±0.78). Calculations from daily ration estimates suggested that only 3.1 % in 1998, and 3.2 % in 1999, of the carbon ingested was of autotrophic origin. This species may therefore be considered carnivorous. Implications of the findings of this study are discussed in terms of carbon cycling in the Southern Ocean.
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- Date Issued: 2000
The presence and role of arbuscular mycorrhizal fungi in coastal sand dune systems
- Authors: Haller, Anjanette H. A
- Date: 2000
- Subjects: Mycorrhizas , Sand dune ecology -- South Africa , Mycorrhizal fungi
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4196 , http://hdl.handle.net/10962/d1003765 , Mycorrhizas , Sand dune ecology -- South Africa , Mycorrhizal fungi
- Description: Arbuscular mycorrhizas (AM) are mutually beneficial symbiotic associations between the roots of plants and certain Zygomycetous fungi. The role of AM fungi in coastal sand dunes has been explored in many parts of the world, though little work has been conducted in South African dune systems. This study aimed to investigate the presence and extent of mycorrhizal colonisation of a coastal sand dune in South Africa. The roots of five plant species (Scaevola plumieri, Arctotheca populifolia, Ipomoea pes-caprae, Ehrharta villosa and Chrysanthemoides monilifera) were sampled along a foredune profile at Old Woman's River in the Eastern Cape. These roots were assessed for the percentage mycorrhizal colonisation they supported. Spores extracted from the rhizosphere sand of each plant species were counted and identified to genus level. Results were related to seasonality and the position of the plants along the profile. All plant species were found to be mycorrhizal. Percentage colonisation ranged from 0-92%, depending on plant species and season. Mycorrhizal colonisation was generally highest in the winter months, and especially so in I pes-caprae and E. villosa. The extent of various mycorrhizal structures in root tissue varied between plant species. Spore numbers ranged from 0-48 spores 100g-1 sand with highest numbers occurring in winter. S. plumieri and A. populifolia were associated with greatest spore abundance. Four fungal genera (Glomus, Acaulospora, Scutellospora and Gigaspora) were identified. Distribution of these genera showed seasonal variations between plant species. A bioassay, using Sorghum, was conducted to test the inoculum potentials of sand from the Scaevola hummock and the IpomoealEhrharta dune. Highest percentage colonisation occurred in plants grown in the Scaevola sand, which also had the lowest root and shoot measurements. The bioassay confirmed that AM propagules are present and viable, even in the mobile sand of the foredune. This study showed that mycorrhizal colonisation and spore numbers varied seasonally, but that the extent of this was dependent on plant species. The position of plants along the foredune profile tended to be less important than plant species. It is thought that the growth cycle and rooting system of each plant species determines seasonal cycles and abundance of AM fungi. Variation within fungal populations probably also impacts on this. Knowledge of the presence and distribution of AM fungi in this system paves the way for more detailed studies which need to examine the role of these endophytes in South African sand dunes.
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- Date Issued: 2000
"Changing ourselves, changing others" : an analysis of the life stories of participants in a training course for volunteers within a non-governmental organisation in the Eastern Cape Province of South Africa
- Authors: Harper, Christopher Duncan
- Date: 2000
- Subjects: Non-governmental organizations -- South Africa -- Eastern Cape , Violence -- South Africa -- Eastern Cape , Abused women -- Counseling of , Women -- Crimes against -- South Africa , Volunteers
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2985 , http://hdl.handle.net/10962/d1002494 , Non-governmental organizations -- South Africa -- Eastern Cape , Violence -- South Africa -- Eastern Cape , Abused women -- Counseling of , Women -- Crimes against -- South Africa , Volunteers
- Description: Gender-based violence has been recognized as a pressing mental health problem that is prevalent within South African society. Non-governmental organizations play a major role in addressing and highlighting the issue. These organizations make use of volunteers in order to assist in meeting their goals. The modernist perspective has been the dominant investigative mode when research into volunteers has been conducted. However, this study has been conducted with an emphasis on narrative. In its use of this constitutionalist and deconstructive perspective, it examines the identity of the research participants within the dominant social and cultural discourses that story their lives. This presents a major challenge to the modernist framework. In examining the life stories of the participants an emergent nature of identity is noted. Through the process of storying their lives and ascribing meaning to their experiences and understandings, the participants engaged in a process of constructing their identity. This research recognizes that identity is both multi-sited and multi-storied. The emphasis on personal agency enables the participants to restory their lives in the light of challenging prevailing discourses. It is in this process of challenge that they reauthor their lives and are in a position to change their own lives and the lives of others.
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- Date Issued: 2000
Desert
- Authors: Harper, Sean Julian
- Date: 2000
- Subjects: Rawls, John, 1921-2002 , Rawls, John, 1921-2002 Theory of justice , Ethics
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2710 , http://hdl.handle.net/10962/d1002840 , Rawls, John, 1921-2002 , Rawls, John, 1921-2002 Theory of justice , Ethics
- Description: This thesis examines the idea of desert as expounded in the work of John Rawls, and some of the implications of this conception of desert for moral and political philosophy. In this work, I analyse a series of arguments against retaining this particular conception of desert.I argue that none of these arguments sufficiently diminishes the force of Rawls’ argument for desert, while many of them do state, and I argue that they are correct in doing so, that this conception of desert is dangerous for political or moral philosophy to maintain. I argue that the moral, political and legal implications of accepting this account of desert severely undermine various institutions of differential treatment, and indeed, moral assessment. I regard it as obvious that societies must, on occasion, treat members of those societies differently, for moral, as well as practical reasons. The Rawlsian account of desert, and the account of responsibility on which it rests, however, will endanger the legitimacy of such procedures. I argue further that the Rawlsian account of desert requires that differences in wealth, and inheritance of wealth, influence and privilege be diminished, if not abolished, if we are to talk of any form of desert meaningfully. I argue that this is a strength of Rawls’ account, and further that any account of desert that is true to the philosophical tradition of the concept will require similar steps to be taken. The primary aim of this thesis is to show that Rawls’ arguments against desert are serious ones, both in terms of strength and scope, and that they must be addressed. I intend to show that these arguments are founded on strong moral intuitions, and that it is plausible that these intuitions may need revision. Finally,I intend to show that desert is an important moral and political concept, and that the disciplines of moral and political philosophy will be impoverished by the absence this concept. This absence, I will argue, is a natural consequence of the acceptance of the Rawlsian arguments.
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- Date Issued: 2000
Replacement of seven 132/66 kv distance protection schemes by means of a generic relay implemented as a strategic spare
- Authors: Harris, Raymond Trevor
- Date: 2000
- Subjects: Protective relays , Electric power systems -- Protection
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10808 , http://hdl.handle.net/10948/34 , Protective relays , Electric power systems -- Protection
- Description: Eskom is experiencing problems in the field of protection maintenance and in-service breakdowns which negatively influence the quality of electrical supply to the consumer, an integral component of the utility business. These facts initiated the research into the further development of a generic relay to be implemented as a strategic spare for the replacement of several schemes operating within Eskom’s southern region. These include the electromechanical, solid state and numerical distance protection relay and scheme failures on the 132 / 66 kV feeder network. Hence, the primary objective of the research is to develop, test and configure the strategic spare in terms of software and peripheral hardware for the input and output terminal connections, generic equations and settings for the purpose of the scheme replacements. The various schemes are assessed for stepped distance and permissive intertripping for three or single pole operation. This is done in conjunction with the internal and external circuit diagrams in order to understand the detailed operation of the scheme and to ensure the effective implementation of the strategic spare. The generic relay is configured for the emergency replacement of the various schemes during in-service breakdowns. This constitutes a temporary installation and therefore the downtime in essence, of all the distance protection schemes that require replacement, is limited to a minimum. This dissertation therefore explores the implementation of the strategic spare.
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- Date Issued: 2000
The implementation of a core architecture for geophysical data acquisition
- Authors: Heasman, Ray Edward
- Date: 2000
- Subjects: Geophysics -- Data processing , Computer software -- Development , Seismometers , Computer input-output equipment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5471 , http://hdl.handle.net/10962/d1005256 , Geophysics -- Data processing , Computer software -- Development , Seismometers , Computer input-output equipment
- Description: This thesis describes the design, development and implementation of the core hardware and software of a modular data acquisition system for geophysical data collection. The primary application for this system is the acquisition and realtime processing of seismic data captured in mines. This system will be used by a commercial supplier of seismic instrumentation, ISS International, as a base architecture for the development of future products. The hardware and software has been designed to be extendable and support distributed processing. The IEEE-1394 High Performance Serial Bus is used to communicate with other CPU modules or peripherals. The software includes a pre-emptive multitasking microkernel, an asynchronous mailbox-based message passing communications system, and a functional IEEE-1394 protocol stack. The reasons for the end design and implementation decisions are given, and the problems encountered in the development of this system are described. A critical assessment of the match between the requirements for the project and the functionality of the implementation is made.
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- Date Issued: 2000
A narrative study of teachers' life stories and their work identity
- Authors: Heaton, Pamela Jane
- Date: 2000
- Subjects: Identity (Psychology) -- Case studies , Teachers -- Case studies , Women teachers -- South Africa , Education -- South Africa -- History , Education -- South Africa -- Eastern Cape , Women teachers -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2989 , http://hdl.handle.net/10962/d1002498 , Identity (Psychology) -- Case studies , Teachers -- Case studies , Women teachers -- South Africa , Education -- South Africa -- History , Education -- South Africa -- Eastern Cape , Women teachers -- South Africa -- Eastern Cape
- Description: Media coverage of the poor state of this country's education system has described public images of the teaching profession which provide a context for the research described in this paper. The research is concerned with how and to what extent work identity is reflected in the life stories of five female teachers from a rural village in the Eastern Cape. A social constructionist approach is taken to the meaning and construction of identity, and the paper describes the process of a narrative method of analyzing and interpreting the stories. An initial analysis reveals that the participants had few career options and little choice of career. Further analysis is concerned with interpreting how the teachers create coherence in their stories around this lack of choice as well as within the larger social and historical context. Simultaneously there is an interpretation of the participants' work identity. The teachers create coherence in their narratives around their families and their socioeconomic or cultural circumstances, but make no explicit reference to the political context of their work choices, which were made in the context of the restraints of the Apartheid era. From each teacher's story an understanding of their unique work identity emerges. These alternative understandings provide a contrast to the images constructed by the media.
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- Date Issued: 2000
Assessing alternative assessment: students' experiences of the different forms of assessment in a Bachelor of Education course
- Authors: Hendricks, Monica
- Date: 2000
- Subjects: Education, Higher -- South Africa -- Evaluation Educational tests and measurements -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1424 , http://hdl.handle.net/10962/d1003305
- Description: In this study I examine the current alternative forms of assessment that were employed in the foundation year of the Bachelor of Education course at Rhodes University in 1998. Since assessment is concerned with ascertaining the amount, and kind, of learning that has taken place, it links learning and teaching. As my role in the course was academic development, I was interested in the nature ofthe development that the course promoted, for lecturers and students. My main intention was to gain insight into students' experiences of the assessment practices. To this end I selected six students, photocopied all their academic writing for the year and interviewed them. In addition, to provide a holistic picture of assessment and marking, I interviewed the six lecturers who team-taught the course. The data thus included the course assignments of the six students and an interview with each student as well as with the course lecturers. The findings show that though policy documents advocate alternative forms of assessment, implementing such assessment is a complex matter for both teachers and students.
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- Date Issued: 2000
Aspects of the ecology and reproductive biology of the limpet, Helcion pruinosus (Gastropoda : prosobranchia)
- Authors: Henninger, Tony Oskar
- Date: 2000
- Subjects: Prosobranchia , Limpets -- Reproduction , Limpets -- Ecology , Prosobranchia -- Ecology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5641 , http://hdl.handle.net/10962/d1005323 , Prosobranchia , Limpets -- Reproduction , Limpets -- Ecology , Prosobranchia -- Ecology
- Description: Helcion pruinosus, the rayed limpet, is found in the midshore region of the intertidal zone, (i.e. the Balanoid zone) of rocky shores, from Saldanha Bay to Sodwana Bay along the coast of South Africa. At Gonubie (32°57'S/25°01'E) this species of limpet was found under boulders, (when not feeding), and could reach average densities of 85/ m². The limpets prefer smooth boulders, avoiding those encrusted by coralline algae or boulders with a rough texture. There was no habitat segregation between adult and juvenile H. pruinosus, i.e. there was no sign of up-shore migration by larger individuals. Males out-numbered females by, on average 1.4 : 1, which was a similar sex ratio to that of the congeneric species, H. pectunculus (Gray, 996). Unlike H. pectunculus, there were no differences in shell lengths between males and females (p = 0.946 at Gonubie, south-east coast and p = 0.961 at Kommetjie, south-west coast; t-test). Shell height could also not be used as a criterion to differentiate between the sexes. The average maximum shell length of H. pruinosus at Gonubie and Kommetjie was 25 mm, but the maximum shell lengths found were 30 mm, (one individual in each case), on both the southeast coast and west coast. Growth occurred most rapidly in the first year of life, with individuals reaching 15 mm after 1 year. In the second year limpet growth slowed to only 7 mm. Sexual maturity was reached at a shell length of between 11 to 14 mm (at an age of 8 months to 1 year). The life-span of H. pruinosus was determined at 2.55 years on the south-east coast and 2.9 years on the south-west coast. Micro-growth bands were produced tidally. Growth occurred allometrically, i.e. shell length increased at a faster rate than shell height. The limpets foraged during low tide, at night, presumably feeding on epilithic algae on the boulders. A second smaller peak of limpet activity was often recorded during the day, when low tide coincided with dawn). More limpets (up to ten times more) were active at spring tides compared to neap tides. Limpet activity was greatest during the spring tides of autumn. During all seasons limpet activity peaked 30 minutes before low water, after which numbers decreased rapidly. All limpets had retreated beneath the boulders before being covered by the flooding tide. It was concluded that the limpets were responding to both endogenous and exogenous cues, but the actual stimulus for retreat could not be determined. The limpets did not return to a fixed scar nor did they return rigidly to a home site. H. pruinosus was found to be gonochoristic. Sexes could be separated, on dissection, according to the colour of their gonads (males had white gonads, whilst that of the females was olive-green). Gonads were present throughout the year in most individuals, i.e. totally spent animals were never observed. Reproductive seasonality was similar in west coast and south-east coast animals. The gonad indices of the west coast limpets were higher, (maximum of 35%), compared to that on the southeast coast, (25%). The animals were probably trickle spawners, with some individuals liberating gametes throughout the year. There was however synchrony in gametogenesis between male and female limpets on both the west coast and south-east coast lines. Gonad indices peaked in the summer months (October to December) with a second minor peak in April/May. These peaks occurred before the release of the gametes in spawning events. The gonad index was lowest in winter, (July). The ovaries were full of mature eggs (oocytes having a diameter of 200 to 250 ~) prior to spawning. The acinal wall thickness had been decreasing prior to spawning. After spawning there was an increase in previtellogenic eggs « 100 μm) in females, and an increase in the acinal wall thickness to indicate spermatogenesis. The two populations are subjected to different environmental conditions and the actual cue for stimulating the release of gametes could not be determined. Finally, a table of differences between H pruinosus and its sister species, H pectunculus was created to show the life-style of H pruinosus.
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- Date Issued: 2000
Assessing the potential for biological invasion - the case of Ammophila arenaria in South Africa
- Authors: Hertling, Ursula M , Lubke, Roy
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6518 , http://hdl.handle.net/10962/d1005947
- Description: Many plants, especially woody species, introduced into South Africa for ornamental or commercial purposes, have become invasive in a number of habitats. Because of the risk of an invasion of coastal dunes by yet another species, the European dune grass Ammophila arenaria, used as a dune stabilizer, is assessed using lists of attributes of invasive species and invasible ecosystems. It is impossible to predict plant invasions, but both invasive species as well as invaded ecosystems are often characterized by certain attributes which facilitate invasions. Many of the species attributes connected with invasion appear to apply to A. arenaria. Above all, the grass is characterized by ecological tolerance and vigorous rhizomatous reproduction. An important site attribute connected with invasion is an evolutionary history with isolation patterns, which applies to the South African Cape coast. We conclude also on the basis of the overseas experience, that the potential for A. arenaria to become invasive needs urgent investigation in the South African context.
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- Date Issued: 2000
Professional development in environmental education in Zanzibar, Tanzania: distances encountered in a semi-distance learning course
- Authors: Heylings, Phillippa Frances
- Date: 2000
- Subjects: Environmental education -- Tanzania -- Zanzibar Distance education -- Tanzania -- Zanzibar Environmental education Distance education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1715 , http://hdl.handle.net/10962/d1003598
- Description: In Zanzibar, in 1995, opportunities for professional development in environmental education were minimal. Yet the demand for professional development was high, especially because of an emphasis on formal qualifications in the country. Credibility was afforded to forms of professional development, aimed at creating more ‘experts’. Ongoing environmental education practice was not achieving its objectives. Into this setting, which was culturally and socio-politically different from the South African context where it was developed, I introduced the Rhodes University Certificate and Gold Fields Participatory Course in Environmental Education (RU/GF); a non-formal, counter-hegemonic course which encouraged critical reflection on the dominant orientations to environmental education practice – including professional development. I used critical ethnographic and action research methods to explore my praxiological interest, the adaptation of the RU/GF curriculum to the Zanzibar context. During the research process, a decision was made to formally accredit the RU/GF course. This decision did not alter the course orientation or the learning process but opened up possibilities for future curriculum development processes. It allowed the students both a formal qualification necessary for status and promotion, and participation in a learning process that challenged the dominant paradigm on professional development and status from within the socio-political context. The research took on a reflexive orientation to research and environmental education. Through a dialectical development of theory, method and results, several important issues emerged. These deal with the ‘distances’ encountered in attempting to address some of the perceived dichotomies in professional development in environmental education through semi-distance learning: the distances between status and learning; the need for career upgrading and the type of learning considered appropriate for professional development in environmental education; the non-quantifiable aims associated with a reflexive orientation to professional development and formal assessment demands for measurable criteria; the democratisation of open-entry courses and the elitism of restricted access; the focus on individual growth and the attainment of a normative grade; theory and practice; and finally distances between learner, text and language. The research supports similar findings emerging from evaluation of the RU/GF course in South Africa and resonates with, and contributes to, issues concerning professional development in environmental education being considered internationally.
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- Date Issued: 2000