The effect of load carriage on selected metabolic and perceptual responses of military personnel
- Authors: Ramabhai, Leena I
- Date: 2000
- Subjects: Marching -- Physiological aspects , Military art and science , Marching -- Psychological aspects , Lifting and carrying
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5111 , http://hdl.handle.net/10962/d1005189
- Description: Taking a multi-disciplinary, integrated approach, the present study sought to examine selected physiological and psycho-physical parameters related to load carriage involving a 12 km march under military conditions. Military constraints hampered, but did not entirely inhibit the secondary aim of the study which concerned the effectiveness of relativising loads in order to normalise responses for all soldiers, irrespective of morphological diversity. Forty three subjects were measured in six groups using a test-retest experimental protocol. They were involved in a rest-broken 12 km march at 4 km.h⁻¹ under 40.5 kg absolute total load and under a relative load of 37% of body mass. Heart rates, ratings of perceived exertion (RPE) as well as area and intensity of discomfort were monitored for all subjects. Ten subjects were measured more extensively with regard to physiology using the Metamax, a portable ergospirometry system that provides all the data needed for a complete functional analysis of lung, heart, circulation and metabolic activity. Physiological responses (fc; fb; V̇T; V̇E; V̇O₂; EE; V̇CO₂; R; T°) indicated subjects were not severely physically taxed and that the loads imposed constituted a sub-maximal demand. Moreover, there appeared to be a limited cumulative effect over the 3.5 h. Data from the first and third hours were similar, while the significantly higher responses in the second hour reflected the challenge of the undulating terrain encountered during this section of the march. All responses during the Relative load conditions mirrored those of the Absolute load condition but, because the demands were less, the trends occurred at a reduced level. Furthermore, the reduction in inter-individual variability indicates that relativised load carriage tends to stress the soldiers in a more uniform manner. All "local" RPE responses were higher than "central" ratings, suggesting soldiers were in good cardiovascular condition and experienced marginally more strain in the lower limbs. There was increased perceived strain corresponding to the increase in gradient, with little cumulative effect over the three hours. The shoulders and feet were the two regions in which most discomfort was experienced; the shoulders being the worst area in the first hour and the feet being rated the worst after the third hour of marching. This study clearly demonstrates the probability of a significant improvement in mean combat-readiness following loaded marching by showing that, if loads are set at levels commensurate with individual capabilities to carry them without undue strain, unnecessary physical demands experienced by smaller, more gracile soldiers are reduced.
- Full Text:
- Date Issued: 2000
- Authors: Ramabhai, Leena I
- Date: 2000
- Subjects: Marching -- Physiological aspects , Military art and science , Marching -- Psychological aspects , Lifting and carrying
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5111 , http://hdl.handle.net/10962/d1005189
- Description: Taking a multi-disciplinary, integrated approach, the present study sought to examine selected physiological and psycho-physical parameters related to load carriage involving a 12 km march under military conditions. Military constraints hampered, but did not entirely inhibit the secondary aim of the study which concerned the effectiveness of relativising loads in order to normalise responses for all soldiers, irrespective of morphological diversity. Forty three subjects were measured in six groups using a test-retest experimental protocol. They were involved in a rest-broken 12 km march at 4 km.h⁻¹ under 40.5 kg absolute total load and under a relative load of 37% of body mass. Heart rates, ratings of perceived exertion (RPE) as well as area and intensity of discomfort were monitored for all subjects. Ten subjects were measured more extensively with regard to physiology using the Metamax, a portable ergospirometry system that provides all the data needed for a complete functional analysis of lung, heart, circulation and metabolic activity. Physiological responses (fc; fb; V̇T; V̇E; V̇O₂; EE; V̇CO₂; R; T°) indicated subjects were not severely physically taxed and that the loads imposed constituted a sub-maximal demand. Moreover, there appeared to be a limited cumulative effect over the 3.5 h. Data from the first and third hours were similar, while the significantly higher responses in the second hour reflected the challenge of the undulating terrain encountered during this section of the march. All responses during the Relative load conditions mirrored those of the Absolute load condition but, because the demands were less, the trends occurred at a reduced level. Furthermore, the reduction in inter-individual variability indicates that relativised load carriage tends to stress the soldiers in a more uniform manner. All "local" RPE responses were higher than "central" ratings, suggesting soldiers were in good cardiovascular condition and experienced marginally more strain in the lower limbs. There was increased perceived strain corresponding to the increase in gradient, with little cumulative effect over the three hours. The shoulders and feet were the two regions in which most discomfort was experienced; the shoulders being the worst area in the first hour and the feet being rated the worst after the third hour of marching. This study clearly demonstrates the probability of a significant improvement in mean combat-readiness following loaded marching by showing that, if loads are set at levels commensurate with individual capabilities to carry them without undue strain, unnecessary physical demands experienced by smaller, more gracile soldiers are reduced.
- Full Text:
- Date Issued: 2000
The evolution of the Brosterlea Volcanic Complex, Eastern Cape, South Africa
- Authors: Surtees, Grant Bradley
- Date: 2000
- Subjects: Volcanism , Geology -- South Africa -- Eastern Cape -- Brosterlea Volcanic Complex , Geology -- South Africa -- Eastern Cape , Flood basalts , Geology, Structural -- South Africa , Formations (Geology) -- South Africa , Geology, Structural -- Maps , Geological mapping
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4944 , http://hdl.handle.net/10962/d1005556 , Volcanism , Geology -- South Africa -- Eastern Cape -- Brosterlea Volcanic Complex , Geology -- South Africa -- Eastern Cape , Flood basalts , Geology, Structural -- South Africa , Formations (Geology) -- South Africa , Geology, Structural -- Maps , Geological mapping
- Description: Detailed field mapping (Map, Appendix B) has been conducted in and around the boundaries of a 14x18km, volcanic complex 35km northeast of Molteno in the Eastern Cape Province, South Africa. The structure is interpreted as a subsidence structure, and is filled with two volcaniclastic breccias, numerous lava flows, a number of sedimentary facies, and lies on a base of Clarens Formation overlying Elliot Formation rocks. This is an important study because 'widespread, voluminous fields of basaltic breccias are very rare (see Hanson and Elliot, 1996) and this is the first time that this type of volcanic complex and its deposits have been described. Detailed analyses of the two volcaniclastic breccias revealed changes in colour, clast types, clast sizes, and degree of alteration over relatively short distances both vertically and laterally within a single breccia unit. The variation in clast sizes implies a lack of sorting of the breccias. The lower of the two volcaniclastic breccias fills the subsidence structure, and outcrops between the Stormberg sedimentary sequence and the overlying Drakensberg basalts and was produced from phreatomagmatic eruptions signalling the start of the break-up of Gondwanaland in the mid-Jurassic. The upper volcaniclastic breccia is interbedded with the flood basalts and is separated from the lower breccia by up to 100m of lava flows in places, it is finer-grained than the lower volcaniclastic breccia, and it extends over 10km south, and over 100km north from the volcanic complex. The upper breccia is inferred to have been transported from outside the study area, from a source presumably similar to the subsidence structure in the volcanic complex. The pyroclastic material forming the upper breccia was transported to the subsidence structure as a laharic debris flow, based on its poorly sorted, unwelded and matrix-supported appearance. However, both breccias are unlikely to have been derived from epiclastic reworking of lava flows as they contain glass shards which are atypical of those derived from the autoclastic component of lava flows. The breccias are therefore not "secondary" lahars. There is also no evidence of any palaeotopographic highs from which the breccias could have been derived as gravity-driven flows. Based on the occurrence of three, 1m thick lacustrine deposits, localised peperite, fluvial reworking of sandstone and breccia in an outcrop to the south of the subsidence structure, and channel-lags encountered only in the upper units of the Clarens Formation and only within the subsidence structure, the palaeoenvironment inferred for the subsidence structure is one of wet sediment, possibly a shallow lake, in a topographic depression fed by small streams. Magmatic intrusions below the subsidence structure heated the water-laden, partly consolidated Clarens Formation sandstones, causing the circulation of pore fluid which resulted in the precipitation of minerals forming pisoliths in the sandstones. Intruding magma mixed, nonexplosively, with the wet, unconsolidated sediments near the base of the Clarens Formation (at approximately 100m below the surface), forming fluidal peperite by a process of sediment fluidisation where magma replaces wet sediment and cools slowly enough to prevent the magma fracturing brittly. Formation of fluidal peperite may have been a precursor to the development of FCIs (Fuel Coolant Interactions) (Busby-Spera and White, 1987). The breccias may represent the products of FCIs and may be the erupted equivalents of the peperites, suggesting a possible genetic link between the two. The peperites may have given way to FCI eruptions due to a number of factors including the drying out of the sediments and/or an increase in the volume of intruded magma below the subsidence structure which may have resulted in a more explosive interaction between sediment and magma. Phreatic activity fragmented and erupted the Clarens Formation sandstone, and stream flows reworked the angular sandstone fragments, pisoliths and sand grains into channelised deposits. With an increase in magmatic activity below the subsidence structure, phreatic activity became phreatomagmatic. The wet, partly consolidated Clarens Formation, and underlying, fully consolidated Elliot Formation sediments were erupted and fragmented. Clasts and individual grains of these sediments were redeposited with juvenile and non-juvenile basaltic material probably by a combination of back fall, where clasts erupted into the air fell directly back into the structure, and backflow where material was erupted out of the structure, but immediately flowed back in as lahars. This material formed the lower volcaniclastic breccia. A fault plane is identified along the southwestern margin of the subsidence structure, and is believed to continue up the western margin to the northwestern corner. A large dolerite body has intruded along the inferred fault plane on the western margin of the structure, and may be related to the formation of the lower volcaniclastic breccia, either directly through fluidisation of wet sediment during its intrusion, or as a dyke extending upwards from a network of sill-like intrusions below the subsidence structure. Geochemical analysis of the Drakensberg basalt lava flows by Mitchell (1980) and Masokwane (1997) revealed four distinct basalt types; the Moshesh's Ford, the Tafelkop, the Roodehoek, and the Vaalkop basalts. Basalt clasts sampled from the lower volcaniclastic breccia were shown to belong to the Moshesh's Ford basalt type which does not outcrop in situ within the subsidence structure. This implies that the Moshesh's Ford basalts were emplaced prior to the formation of the lower volcaniclastic breccia, and may have acted as a "cap-rock" over the system, allowing pressure from the vaporised fluids, heated by intruding basalt, to build up. The Moshesh's Ford basalt type was erupted prior to the resultant phreatomagmatic events forming the lower volcaniclastic breccia.
- Full Text:
- Date Issued: 2000
- Authors: Surtees, Grant Bradley
- Date: 2000
- Subjects: Volcanism , Geology -- South Africa -- Eastern Cape -- Brosterlea Volcanic Complex , Geology -- South Africa -- Eastern Cape , Flood basalts , Geology, Structural -- South Africa , Formations (Geology) -- South Africa , Geology, Structural -- Maps , Geological mapping
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4944 , http://hdl.handle.net/10962/d1005556 , Volcanism , Geology -- South Africa -- Eastern Cape -- Brosterlea Volcanic Complex , Geology -- South Africa -- Eastern Cape , Flood basalts , Geology, Structural -- South Africa , Formations (Geology) -- South Africa , Geology, Structural -- Maps , Geological mapping
- Description: Detailed field mapping (Map, Appendix B) has been conducted in and around the boundaries of a 14x18km, volcanic complex 35km northeast of Molteno in the Eastern Cape Province, South Africa. The structure is interpreted as a subsidence structure, and is filled with two volcaniclastic breccias, numerous lava flows, a number of sedimentary facies, and lies on a base of Clarens Formation overlying Elliot Formation rocks. This is an important study because 'widespread, voluminous fields of basaltic breccias are very rare (see Hanson and Elliot, 1996) and this is the first time that this type of volcanic complex and its deposits have been described. Detailed analyses of the two volcaniclastic breccias revealed changes in colour, clast types, clast sizes, and degree of alteration over relatively short distances both vertically and laterally within a single breccia unit. The variation in clast sizes implies a lack of sorting of the breccias. The lower of the two volcaniclastic breccias fills the subsidence structure, and outcrops between the Stormberg sedimentary sequence and the overlying Drakensberg basalts and was produced from phreatomagmatic eruptions signalling the start of the break-up of Gondwanaland in the mid-Jurassic. The upper volcaniclastic breccia is interbedded with the flood basalts and is separated from the lower breccia by up to 100m of lava flows in places, it is finer-grained than the lower volcaniclastic breccia, and it extends over 10km south, and over 100km north from the volcanic complex. The upper breccia is inferred to have been transported from outside the study area, from a source presumably similar to the subsidence structure in the volcanic complex. The pyroclastic material forming the upper breccia was transported to the subsidence structure as a laharic debris flow, based on its poorly sorted, unwelded and matrix-supported appearance. However, both breccias are unlikely to have been derived from epiclastic reworking of lava flows as they contain glass shards which are atypical of those derived from the autoclastic component of lava flows. The breccias are therefore not "secondary" lahars. There is also no evidence of any palaeotopographic highs from which the breccias could have been derived as gravity-driven flows. Based on the occurrence of three, 1m thick lacustrine deposits, localised peperite, fluvial reworking of sandstone and breccia in an outcrop to the south of the subsidence structure, and channel-lags encountered only in the upper units of the Clarens Formation and only within the subsidence structure, the palaeoenvironment inferred for the subsidence structure is one of wet sediment, possibly a shallow lake, in a topographic depression fed by small streams. Magmatic intrusions below the subsidence structure heated the water-laden, partly consolidated Clarens Formation sandstones, causing the circulation of pore fluid which resulted in the precipitation of minerals forming pisoliths in the sandstones. Intruding magma mixed, nonexplosively, with the wet, unconsolidated sediments near the base of the Clarens Formation (at approximately 100m below the surface), forming fluidal peperite by a process of sediment fluidisation where magma replaces wet sediment and cools slowly enough to prevent the magma fracturing brittly. Formation of fluidal peperite may have been a precursor to the development of FCIs (Fuel Coolant Interactions) (Busby-Spera and White, 1987). The breccias may represent the products of FCIs and may be the erupted equivalents of the peperites, suggesting a possible genetic link between the two. The peperites may have given way to FCI eruptions due to a number of factors including the drying out of the sediments and/or an increase in the volume of intruded magma below the subsidence structure which may have resulted in a more explosive interaction between sediment and magma. Phreatic activity fragmented and erupted the Clarens Formation sandstone, and stream flows reworked the angular sandstone fragments, pisoliths and sand grains into channelised deposits. With an increase in magmatic activity below the subsidence structure, phreatic activity became phreatomagmatic. The wet, partly consolidated Clarens Formation, and underlying, fully consolidated Elliot Formation sediments were erupted and fragmented. Clasts and individual grains of these sediments were redeposited with juvenile and non-juvenile basaltic material probably by a combination of back fall, where clasts erupted into the air fell directly back into the structure, and backflow where material was erupted out of the structure, but immediately flowed back in as lahars. This material formed the lower volcaniclastic breccia. A fault plane is identified along the southwestern margin of the subsidence structure, and is believed to continue up the western margin to the northwestern corner. A large dolerite body has intruded along the inferred fault plane on the western margin of the structure, and may be related to the formation of the lower volcaniclastic breccia, either directly through fluidisation of wet sediment during its intrusion, or as a dyke extending upwards from a network of sill-like intrusions below the subsidence structure. Geochemical analysis of the Drakensberg basalt lava flows by Mitchell (1980) and Masokwane (1997) revealed four distinct basalt types; the Moshesh's Ford, the Tafelkop, the Roodehoek, and the Vaalkop basalts. Basalt clasts sampled from the lower volcaniclastic breccia were shown to belong to the Moshesh's Ford basalt type which does not outcrop in situ within the subsidence structure. This implies that the Moshesh's Ford basalts were emplaced prior to the formation of the lower volcaniclastic breccia, and may have acted as a "cap-rock" over the system, allowing pressure from the vaporised fluids, heated by intruding basalt, to build up. The Moshesh's Ford basalt type was erupted prior to the resultant phreatomagmatic events forming the lower volcaniclastic breccia.
- Full Text:
- Date Issued: 2000
The experience of multi-cultural communication within a South African organization
- Authors: Lesch, Anthea M
- Date: 2000
- Subjects: Intercultural communication -- South Africa , Communication in management -- South Africa , Communication in personnel management -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:3008 , http://hdl.handle.net/10962/d1002517 , Intercultural communication -- South Africa , Communication in management -- South Africa , Communication in personnel management -- South Africa
- Description: This research study was conducted in an attempt to explore the experience of multicultural communication within a South African organization. To this end employees, representing both Black and White culture, within a South African organization in the throes of transformation, were accessed. A model of managing diversity, focussing on the personal, interpersonal and organizational levels, was utilized in an attempt to uncover the nature of the experience of multi-cultural communication within Company X. A qualitative research design, and more specifically the case study method was employed in this study. Consistent with the case study approach a number of data sources were accessed. The primary data source consisted of a 3-stage interview process. Other data sources included documentary sources and company publications. By accessing multiple data sources, the researcher attempted to gain a holistic understanding of the experience of multi-cultural communication. It was found that the societal context of our post-Apartheid society exercises a profound influence on multi-cultural communication. Under Apartheid cultural separation was promoted. Diverse peoples thus have little common basis for interaction and view each other with skepticism and distrust. This exercises an effect on the personal and organizational levels of the managing diversity model. Influences at the personal level relate to the cultural paradigms of the individuals which provide the rules governing interactions and affect judgements of acceptable and unacceptable behaviours. Issues at the organizational level relate to its structures and policies which are still based on the “white is right ideology”. These issues, in turn, affect the interpersonal level of managing diversity, i.e., where the interactions occur, causing “communication short circuits” within the process of multi-cultural communication. In order to deal with failed multi-cultural communication, the individuals have developed a number of coping strategies. The results of the study indicate that both the organization and its employees share a responsibility for creating an environment that will facilitate effective multi-cultural communication.
- Full Text:
- Date Issued: 2000
- Authors: Lesch, Anthea M
- Date: 2000
- Subjects: Intercultural communication -- South Africa , Communication in management -- South Africa , Communication in personnel management -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:3008 , http://hdl.handle.net/10962/d1002517 , Intercultural communication -- South Africa , Communication in management -- South Africa , Communication in personnel management -- South Africa
- Description: This research study was conducted in an attempt to explore the experience of multicultural communication within a South African organization. To this end employees, representing both Black and White culture, within a South African organization in the throes of transformation, were accessed. A model of managing diversity, focussing on the personal, interpersonal and organizational levels, was utilized in an attempt to uncover the nature of the experience of multi-cultural communication within Company X. A qualitative research design, and more specifically the case study method was employed in this study. Consistent with the case study approach a number of data sources were accessed. The primary data source consisted of a 3-stage interview process. Other data sources included documentary sources and company publications. By accessing multiple data sources, the researcher attempted to gain a holistic understanding of the experience of multi-cultural communication. It was found that the societal context of our post-Apartheid society exercises a profound influence on multi-cultural communication. Under Apartheid cultural separation was promoted. Diverse peoples thus have little common basis for interaction and view each other with skepticism and distrust. This exercises an effect on the personal and organizational levels of the managing diversity model. Influences at the personal level relate to the cultural paradigms of the individuals which provide the rules governing interactions and affect judgements of acceptable and unacceptable behaviours. Issues at the organizational level relate to its structures and policies which are still based on the “white is right ideology”. These issues, in turn, affect the interpersonal level of managing diversity, i.e., where the interactions occur, causing “communication short circuits” within the process of multi-cultural communication. In order to deal with failed multi-cultural communication, the individuals have developed a number of coping strategies. The results of the study indicate that both the organization and its employees share a responsibility for creating an environment that will facilitate effective multi-cultural communication.
- Full Text:
- Date Issued: 2000
The exploitation of Upogebia africana (Crustacea: Thalassinidae) for bait in the Knysna Estuary
- Hodgson, Alan N, Allanson, Brian R, Cretchley, Robyn
- Authors: Hodgson, Alan N , Allanson, Brian R , Cretchley, Robyn
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6924 , http://hdl.handle.net/10962/d1011911
- Description: The activities of people collecting Upogebia africana for bait at six popular collecting sites in the Knysna Estuary were monitored from February 1995 until April 1996. Three groups of bait harvesters were identified on the basis of their source of income: subsistence fishers who rely on bait collecting and fishing for their income; supplementary fishers who catch fish to supplement their income; leisure anglers who draw no income from fishing. Two groups of collectors were identified based on methods of collecting bait and fishing: leisure anglers who collect bait using a prawn pusher or pump and fish using a rod and tackle; non-leisure fishers who collect using tin cans and fish with hand or planted lines. The average harvest of bait per collecting trip by leisure anglers was 59 mud prawns, whereas non-leisure fishers took 101 animals, twice the legal limit. The numbers of bait collectors present per mud bank were found to be highest on public holidays ([horizontal bar over]X = 43.5) and higher during the summer holidays ([horizontal bar over]X = 16.5) than during the spring/summer ([horizontal bar over]X = 8.6) and autumn/winter ([horizontal bar over]X = 4.6) periods. Most collectors spent 11-30 minutes on the mud banks. It was estimated that 1.86 x 10[superscript 6] U. africana or about 740 kg (dry mass) was removed by bait collectors annually from the six bait-collecting sites studied. This represented about 8.5% of the mud prawn stocks at these sites and about 0.9% of the entire estuary stock. 85% of the mud prawns taken as bait was removed by 77% of the bait collectors who were the non-leisure fishers.
- Full Text:
- Date Issued: 2000
- Authors: Hodgson, Alan N , Allanson, Brian R , Cretchley, Robyn
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6924 , http://hdl.handle.net/10962/d1011911
- Description: The activities of people collecting Upogebia africana for bait at six popular collecting sites in the Knysna Estuary were monitored from February 1995 until April 1996. Three groups of bait harvesters were identified on the basis of their source of income: subsistence fishers who rely on bait collecting and fishing for their income; supplementary fishers who catch fish to supplement their income; leisure anglers who draw no income from fishing. Two groups of collectors were identified based on methods of collecting bait and fishing: leisure anglers who collect bait using a prawn pusher or pump and fish using a rod and tackle; non-leisure fishers who collect using tin cans and fish with hand or planted lines. The average harvest of bait per collecting trip by leisure anglers was 59 mud prawns, whereas non-leisure fishers took 101 animals, twice the legal limit. The numbers of bait collectors present per mud bank were found to be highest on public holidays ([horizontal bar over]X = 43.5) and higher during the summer holidays ([horizontal bar over]X = 16.5) than during the spring/summer ([horizontal bar over]X = 8.6) and autumn/winter ([horizontal bar over]X = 4.6) periods. Most collectors spent 11-30 minutes on the mud banks. It was estimated that 1.86 x 10[superscript 6] U. africana or about 740 kg (dry mass) was removed by bait collectors annually from the six bait-collecting sites studied. This represented about 8.5% of the mud prawn stocks at these sites and about 0.9% of the entire estuary stock. 85% of the mud prawns taken as bait was removed by 77% of the bait collectors who were the non-leisure fishers.
- Full Text:
- Date Issued: 2000
The geomorphological impacts of impoundments, with particular reference to tributary bar development on the Keiskamma River, Eastern Cape
- Authors: McGregor, Gillian Kathleen
- Date: 2000
- Subjects: Rivers--South Africa--Regulation , Rivers--South Africa--Regulation--Environmental aspects , Rivers--South Africa--Eastern Cape , Geomorphology--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4835 , http://hdl.handle.net/10962/d1005510 , Rivers--South Africa--Regulation , Rivers--South Africa--Regulation--Environmental aspects , Rivers--South Africa--Eastern Cape , Geomorphology--South Africa--Eastern Cape
- Description: The primary aim of this research was to develop and test a conceptual model of the geomorphological impacts of river regulation, based on a review of relevant international literature. It was motivated by the fact that there is very little local information on the topic, and it was intended that the model might provide a starting point for assessing the impact of impoundments on South African river systems. At present most research in South Africa on the impact of impoundments is undertaken from an ecological perspective. In order to manage our water resources sustainably it is necessary to have a better understanding of our river systems. South Africa is characterised by a variable climatic regime and, in order to supply water to the various user sectors of the nation, dams have to be larger than elsewhere in the world, to trap most of the mean annual runoff and provide a reliable water store (Alexander, 1985). South African dams have been designed to reduce the variability of a naturally variable regime. The impact of flow regulation in dryland rivers has been described as 'ecologically catastrophic at every level.' It is therefore hardly surprising that the impact of these dams on the natural functioning of rivers is substantial. The conceptual model showed that there are many responses to river impoundment, which are varied and complex, both in time and space. Responses or secondary impacts depended on the nature and degree of the primary impact or process alteration, on the sediment and flow regime of the river. High flows were affected in all cases and low flows were affected in most cases. The simplest form of change was Petts' (1979) concept of 'accommodation' of the regulated flow within the existing channel form. More complex responses occUrred where the channel perimeter was unstable, or where tributaries introduced fresh sediment loads. The river could adjust its long profile, cross sectional area and substrate composition by aggradation or degradation. The conceptual model was used in the Building Block Methodology to predict impoundment impacts at Instream Flow Requirement workshops on the Berg, Komati and Bivane rivers. It was also used in assessing the impact of the Sandile Dam on the Keiskamma river. Tributary junctions were identified as likely sites of change, and the morphology of bars at these junctions was investigated. Due to the number of variables affecting the sediment and flow regime in the system, and due to the fact that the primary impacts were not substantial, it was not possible to come to any decisive conclusions. It would seem that the dam is well located in the catchment, and, because the water is not heavily utilised, the secondary impacts are not great. The conceptual model was found to be a useful basic tool which might contribute to a better understanding of our river systems, and ultimately to improved sustainable resource management.
- Full Text:
- Date Issued: 2000
- Authors: McGregor, Gillian Kathleen
- Date: 2000
- Subjects: Rivers--South Africa--Regulation , Rivers--South Africa--Regulation--Environmental aspects , Rivers--South Africa--Eastern Cape , Geomorphology--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4835 , http://hdl.handle.net/10962/d1005510 , Rivers--South Africa--Regulation , Rivers--South Africa--Regulation--Environmental aspects , Rivers--South Africa--Eastern Cape , Geomorphology--South Africa--Eastern Cape
- Description: The primary aim of this research was to develop and test a conceptual model of the geomorphological impacts of river regulation, based on a review of relevant international literature. It was motivated by the fact that there is very little local information on the topic, and it was intended that the model might provide a starting point for assessing the impact of impoundments on South African river systems. At present most research in South Africa on the impact of impoundments is undertaken from an ecological perspective. In order to manage our water resources sustainably it is necessary to have a better understanding of our river systems. South Africa is characterised by a variable climatic regime and, in order to supply water to the various user sectors of the nation, dams have to be larger than elsewhere in the world, to trap most of the mean annual runoff and provide a reliable water store (Alexander, 1985). South African dams have been designed to reduce the variability of a naturally variable regime. The impact of flow regulation in dryland rivers has been described as 'ecologically catastrophic at every level.' It is therefore hardly surprising that the impact of these dams on the natural functioning of rivers is substantial. The conceptual model showed that there are many responses to river impoundment, which are varied and complex, both in time and space. Responses or secondary impacts depended on the nature and degree of the primary impact or process alteration, on the sediment and flow regime of the river. High flows were affected in all cases and low flows were affected in most cases. The simplest form of change was Petts' (1979) concept of 'accommodation' of the regulated flow within the existing channel form. More complex responses occUrred where the channel perimeter was unstable, or where tributaries introduced fresh sediment loads. The river could adjust its long profile, cross sectional area and substrate composition by aggradation or degradation. The conceptual model was used in the Building Block Methodology to predict impoundment impacts at Instream Flow Requirement workshops on the Berg, Komati and Bivane rivers. It was also used in assessing the impact of the Sandile Dam on the Keiskamma river. Tributary junctions were identified as likely sites of change, and the morphology of bars at these junctions was investigated. Due to the number of variables affecting the sediment and flow regime in the system, and due to the fact that the primary impacts were not substantial, it was not possible to come to any decisive conclusions. It would seem that the dam is well located in the catchment, and, because the water is not heavily utilised, the secondary impacts are not great. The conceptual model was found to be a useful basic tool which might contribute to a better understanding of our river systems, and ultimately to improved sustainable resource management.
- Full Text:
- Date Issued: 2000
The growth and reproduction of Patella granularis (Mollusca : patellogastropoda) on the south-east coast of South Africa
- Authors: Vat, Laura Suzanne
- Date: 2000
- Subjects: Patellidae Limpets -- South Africa Mollusks -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5702 , http://hdl.handle.net/10962/d1005388
- Description: Aspects of the biology and ecology of Patella granularis were investigated along a 130km stretch of the south-east coast of South Africa. Distribution, biomass, density and population structure were investigated at seven localities. In addition, a more detailed study of the growth rate and reproductive biology of populations inhabiting three different substrata (aeolianite, quartzitic sandstone and mussel shells) was conducted. The genetic relationships between these three populations was also examined, as was the foraging behaviour of the limpets inhabiting an aeolianite and a quartzitic sandstone shore. Finally, differences in food availability on the different substrata were studied. On the south-east coast, P. granularis has a wide intertidal distribution, occurring from the upper Balanoid zone through to the Cochlear zone, where it is a common inhabitant of mussel shells. The mean shell length of P. granularis was found to decrease down the shore. The largest limpets (46.6 mm shell length) were found on an offshore island in Algoa Bay. At most localities investigated, the sex ratio deviated from a 1:1 ratio with more males than females being recorded on five shores. Both limpet density and biomass were lower on the south-east coast when compared to data published for west coast populations. On the south-east coast, both density and dry biomass were highest in the lower Balanoid zone. Allozyme electrophoresis indicated that P. granularis inhabiting aeolianite, quartzitic sandstone and mussel shells are all part of a single population. Extremely high genetic identity values (0.998), low levels of heterozygosities (0.035 - 0.061), low levels of polymorphisms (25% - 31%) and low FST values (0.021) all suggest that the three populations of P. granularis form a common breeding group, despite the high levels of phenotypic plasticity observed. On all shores, P. granularis was found to grow allometrically, increasing in shell height more rapidly than shell length. Estimation of the growth rate (determined by the Von Bertalanffy growth model) of P. granularis suggested that limpets inhabiting the mussel shells grew more slowly, and attained a smaller maximum size, than those inhabiting both the aeolianite and the quartzite (K = 0.25, 0.32 and 0.33 respectively; 27.12 mm, 31.89 mm and 32.96 mm respectively). Previous work has shown that west coast P. granularis grow more quickly (K = 0.7) and reach a greater size (. 40 mm). Translocation of limpets among sites suggested that limpet size in the mussel beds was spatially constrained. Shell microgrowth bands were deposited tidally, but could not be used for aging limpets due to shell erosion. Limpets from the aeolianite had the greatest reproductive fitness, producing more eggs (.366 000/limpet) than those inhabiting quartzite (.119 500/limpet) or mussel shell limpets (.85 800/limpet). Aeolianite limpets also spawned throughout the year, whereas those from the quartzite and mussel shells spawned twice a year (once in winter and once in summer) although a great deal of interannual variability was observed. The onset of sexual maturity occurred at a similar age in all limpets (1 - 2 years) and is probably genetically entrenched. P. granularis inhabiting both an aeolianite and a quartzitic shore were active during nocturnal low tides. All limpets returned to a home scar after foraging. Whilst foraging, limpets inhabiting the aeolianite shore moved shorter distances (.17 cm) at a slower rate than those from quartzite (.30 cm). Limpets that were translocated from one substratum to the other initially moved similar distances to the source group, but after a maximum period of one week, moved distances that mirrored those moved by the resident limpets. Neither season nor tidal phase influenced the distances foraged. No directionality in foraging was found. Wear of radula teeth, particularly the pluricuspid tooth, was greater in limpets from the quartzite. It is hypothesised that the observed differences in life-history parameters and foraging behaviour of limpets both within the south-east coast and between the west and south-east coasts are related to food abundance. Chlorophyll-a, and hence microalgal biomass, was consistently higher on aeolianite (.2.5 times) than on both quartzite and mussel shells. Estimates of chlorophyll-a were higher (although not significantly) in winter. Previous studies determined that primary productivity is also higher along the west coast. Finally, the lack of evidence for migration of limpets from the low-shore to high-shore in south-east coast P. granularis is discussed. It is suggested that this species settles opportunistically within its physiological tolerances and responds morphologically to localised environmental conditions.
- Full Text:
- Date Issued: 2000
- Authors: Vat, Laura Suzanne
- Date: 2000
- Subjects: Patellidae Limpets -- South Africa Mollusks -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5702 , http://hdl.handle.net/10962/d1005388
- Description: Aspects of the biology and ecology of Patella granularis were investigated along a 130km stretch of the south-east coast of South Africa. Distribution, biomass, density and population structure were investigated at seven localities. In addition, a more detailed study of the growth rate and reproductive biology of populations inhabiting three different substrata (aeolianite, quartzitic sandstone and mussel shells) was conducted. The genetic relationships between these three populations was also examined, as was the foraging behaviour of the limpets inhabiting an aeolianite and a quartzitic sandstone shore. Finally, differences in food availability on the different substrata were studied. On the south-east coast, P. granularis has a wide intertidal distribution, occurring from the upper Balanoid zone through to the Cochlear zone, where it is a common inhabitant of mussel shells. The mean shell length of P. granularis was found to decrease down the shore. The largest limpets (46.6 mm shell length) were found on an offshore island in Algoa Bay. At most localities investigated, the sex ratio deviated from a 1:1 ratio with more males than females being recorded on five shores. Both limpet density and biomass were lower on the south-east coast when compared to data published for west coast populations. On the south-east coast, both density and dry biomass were highest in the lower Balanoid zone. Allozyme electrophoresis indicated that P. granularis inhabiting aeolianite, quartzitic sandstone and mussel shells are all part of a single population. Extremely high genetic identity values (0.998), low levels of heterozygosities (0.035 - 0.061), low levels of polymorphisms (25% - 31%) and low FST values (0.021) all suggest that the three populations of P. granularis form a common breeding group, despite the high levels of phenotypic plasticity observed. On all shores, P. granularis was found to grow allometrically, increasing in shell height more rapidly than shell length. Estimation of the growth rate (determined by the Von Bertalanffy growth model) of P. granularis suggested that limpets inhabiting the mussel shells grew more slowly, and attained a smaller maximum size, than those inhabiting both the aeolianite and the quartzite (K = 0.25, 0.32 and 0.33 respectively; 27.12 mm, 31.89 mm and 32.96 mm respectively). Previous work has shown that west coast P. granularis grow more quickly (K = 0.7) and reach a greater size (. 40 mm). Translocation of limpets among sites suggested that limpet size in the mussel beds was spatially constrained. Shell microgrowth bands were deposited tidally, but could not be used for aging limpets due to shell erosion. Limpets from the aeolianite had the greatest reproductive fitness, producing more eggs (.366 000/limpet) than those inhabiting quartzite (.119 500/limpet) or mussel shell limpets (.85 800/limpet). Aeolianite limpets also spawned throughout the year, whereas those from the quartzite and mussel shells spawned twice a year (once in winter and once in summer) although a great deal of interannual variability was observed. The onset of sexual maturity occurred at a similar age in all limpets (1 - 2 years) and is probably genetically entrenched. P. granularis inhabiting both an aeolianite and a quartzitic shore were active during nocturnal low tides. All limpets returned to a home scar after foraging. Whilst foraging, limpets inhabiting the aeolianite shore moved shorter distances (.17 cm) at a slower rate than those from quartzite (.30 cm). Limpets that were translocated from one substratum to the other initially moved similar distances to the source group, but after a maximum period of one week, moved distances that mirrored those moved by the resident limpets. Neither season nor tidal phase influenced the distances foraged. No directionality in foraging was found. Wear of radula teeth, particularly the pluricuspid tooth, was greater in limpets from the quartzite. It is hypothesised that the observed differences in life-history parameters and foraging behaviour of limpets both within the south-east coast and between the west and south-east coasts are related to food abundance. Chlorophyll-a, and hence microalgal biomass, was consistently higher on aeolianite (.2.5 times) than on both quartzite and mussel shells. Estimates of chlorophyll-a were higher (although not significantly) in winter. Previous studies determined that primary productivity is also higher along the west coast. Finally, the lack of evidence for migration of limpets from the low-shore to high-shore in south-east coast P. granularis is discussed. It is suggested that this species settles opportunistically within its physiological tolerances and responds morphologically to localised environmental conditions.
- Full Text:
- 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.
- Full Text:
- Date Issued: 2000
- 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.
- Full Text:
- Date Issued: 2000
The implications of the introduction of outcomes based education in the natural sciences curriculum at Cape College of Education: the assessment of perceptions of squatter camp teachers in Khayelitsha towards the outcomes based education
- Authors: Booi, Kwanele
- Date: 2000
- Subjects: Competency-based education -- South Africa Competency-based education -- Evaluation Competency-based education -- South Africa -- Khayelitsha -- Evaluation Physical sciences -- Study and teaching -- Evaluation Life sciences -- Study and teaching -- Evaluation Cape College of Education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1569 , http://hdl.handle.net/10962/d1003451
- Description: 1. This pilot study is a survey of practices of natural sciences educators at Cape College of Education to establish if they reflect the conceptual development, development of skills, change of attitudes and values that are the pillars of the Outcomes Based Education (OBE). Their approaches of lecturing have been assessed to determine if they incorporate investigative approaches based on social constructivism, the theory underpinning Curriculum 2005. The status of science education in the college has been analyzed to establish whether the curriculum can adapt itself to the specifications of the new curriculum. It has been concluded that the educators at Cape College of Education need to be empowered about strategies that will help them function along the principles embracing Curriculum 2005 specifications. The educators have shown not to be ready to practice social constructivism and the assessment strategies incorporated in their programmes do not embrace a variety of approaches that will enable their learners to develop conceptually, skill wise and enable them to develop change in attitudes and values. Investigative approaches to practical work appear to be lacking in the college teaching/learning and this also indicates that Curriculum 2005 will take time to be properly implemented at Cape College of Education. 2. This study is based on the practices of science educators in the squatter-camp school in Khayelitsha, a densely populated area for blacks near Cape Town. Teachers at Vuselela primary school were interviewed about their teaching assessment strategies to establish whether they incorporate a learner centred approach, which is the necessity for the Outcomes Based Education approach. Also some of the lessons they taught were observed in order to find out whether they validate what transpired from the interviews through a process of triangulation. It has become evident that the teachers are to some extent aware of the changes the education system is going through in South Africa. It also became clear from the study that the teachers are still lacking expertise as to how to practice along the lines of Curriculum 2005, the South African version of Outcomes Based Education (OBE). They also showed that they are keen to learn and practice OBE even though more opportunities need to be created for their epistemological empowerment as well as empowerment on the content of science.
- Full Text:
- Date Issued: 2000
- Authors: Booi, Kwanele
- Date: 2000
- Subjects: Competency-based education -- South Africa Competency-based education -- Evaluation Competency-based education -- South Africa -- Khayelitsha -- Evaluation Physical sciences -- Study and teaching -- Evaluation Life sciences -- Study and teaching -- Evaluation Cape College of Education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1569 , http://hdl.handle.net/10962/d1003451
- Description: 1. This pilot study is a survey of practices of natural sciences educators at Cape College of Education to establish if they reflect the conceptual development, development of skills, change of attitudes and values that are the pillars of the Outcomes Based Education (OBE). Their approaches of lecturing have been assessed to determine if they incorporate investigative approaches based on social constructivism, the theory underpinning Curriculum 2005. The status of science education in the college has been analyzed to establish whether the curriculum can adapt itself to the specifications of the new curriculum. It has been concluded that the educators at Cape College of Education need to be empowered about strategies that will help them function along the principles embracing Curriculum 2005 specifications. The educators have shown not to be ready to practice social constructivism and the assessment strategies incorporated in their programmes do not embrace a variety of approaches that will enable their learners to develop conceptually, skill wise and enable them to develop change in attitudes and values. Investigative approaches to practical work appear to be lacking in the college teaching/learning and this also indicates that Curriculum 2005 will take time to be properly implemented at Cape College of Education. 2. This study is based on the practices of science educators in the squatter-camp school in Khayelitsha, a densely populated area for blacks near Cape Town. Teachers at Vuselela primary school were interviewed about their teaching assessment strategies to establish whether they incorporate a learner centred approach, which is the necessity for the Outcomes Based Education approach. Also some of the lessons they taught were observed in order to find out whether they validate what transpired from the interviews through a process of triangulation. It has become evident that the teachers are to some extent aware of the changes the education system is going through in South Africa. It also became clear from the study that the teachers are still lacking expertise as to how to practice along the lines of Curriculum 2005, the South African version of Outcomes Based Education (OBE). They also showed that they are keen to learn and practice OBE even though more opportunities need to be created for their epistemological empowerment as well as empowerment on the content of science.
- Full Text:
- Date Issued: 2000
The interpretation of ABET placement tests in the recognition of prior learning
- Authors: Blunt, Sandra Viki
- Date: 2000
- Subjects: English language -- Ability testing , English language -- Study and teaching -- Foreign speakers
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:1582 , http://hdl.handle.net/10962/d1003464
- Description: This thesis analyses the way in which placement testing is being interpreted in Adult Basic Education and Training (ABET). The thesis examines whether the placement tests used in the case study were valid in terms of whether their contents were relevant and authentic with regard to what English second language speakers could reasonably be expected to know. Adult learners have differing English second language knowledge depending on the different contexts in which they have learned their second language. This thesis investigates the implications of the different contexts and different language needs of adult learners for the testing of English as a second language for placement purposes in ABET programmes. The thesis examined two placement tests to determine how the recognition of prior second language learning was being interpreted and how the interpretation affected the validity of the tests. Learners= perceptions of the assessment process and test content were elicited in order to determine whether a policy of transparency had been followed in the implementation of the assessment. It was also established what the goals of the organisation were in implementing an ABET programme. This research suggests that placement testing should be viewed holistically; in other words, the goals of the organisation and the level of transparency affect the validity of the placement test. The conclusions were that the placement tests were inauthentic since their contents excluded certain vital aspects of real life performance, namely, that related to the work context. The research revealed that if the placement testing process and the ABET programme are integrated into the culture of the organisation and if employees are remunerated when they have passed the different levels in the programme, the programme is likely to achieve a fair measure of success. Recommendations are that literacy should be viewed as based on a variety of contexts and uses and that therefore tests should be tailored to suit each particular organisation and should contain workrelated content. Furthermore, multiple methods of assessment should be considered.
- Full Text:
- Date Issued: 2000
- Authors: Blunt, Sandra Viki
- Date: 2000
- Subjects: English language -- Ability testing , English language -- Study and teaching -- Foreign speakers
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:1582 , http://hdl.handle.net/10962/d1003464
- Description: This thesis analyses the way in which placement testing is being interpreted in Adult Basic Education and Training (ABET). The thesis examines whether the placement tests used in the case study were valid in terms of whether their contents were relevant and authentic with regard to what English second language speakers could reasonably be expected to know. Adult learners have differing English second language knowledge depending on the different contexts in which they have learned their second language. This thesis investigates the implications of the different contexts and different language needs of adult learners for the testing of English as a second language for placement purposes in ABET programmes. The thesis examined two placement tests to determine how the recognition of prior second language learning was being interpreted and how the interpretation affected the validity of the tests. Learners= perceptions of the assessment process and test content were elicited in order to determine whether a policy of transparency had been followed in the implementation of the assessment. It was also established what the goals of the organisation were in implementing an ABET programme. This research suggests that placement testing should be viewed holistically; in other words, the goals of the organisation and the level of transparency affect the validity of the placement test. The conclusions were that the placement tests were inauthentic since their contents excluded certain vital aspects of real life performance, namely, that related to the work context. The research revealed that if the placement testing process and the ABET programme are integrated into the culture of the organisation and if employees are remunerated when they have passed the different levels in the programme, the programme is likely to achieve a fair measure of success. Recommendations are that literacy should be viewed as based on a variety of contexts and uses and that therefore tests should be tailored to suit each particular organisation and should contain workrelated content. Furthermore, multiple methods of assessment should be considered.
- Full Text:
- Date Issued: 2000
The isolation and partial characterization of a2-antiplasmin and plasminogen from ostrich plasma
- Authors: Thomas, Adele René
- Date: 2000
- Subjects: Serpins , Ostriches , Antifibrinolytic agents , Plasminogen , Plasmin
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11080 , http://hdl.handle.net/10948/274 , http://hdl.handle.net/10948/d1005751 , Serpins , Ostriches , Antifibrinolytic agents , Plasminogen , Plasmin
- Description: This study reports the isolation, purification and partial characterisation of the ostrich serpin, a2AP, as well as its target enzyme, ostrich plasmin, in its active and inactive proenzyme, viz. plasminogen, forms. Three different procedures were undertaken to isolate and purify ostrich a2AP. The first one involved L-lysine-Sepharose chromatography, ammonium sulfate fractionation, ion-exchange chromatography on Toyopearl Super-Q 650S, and ostrich plasminogen-Sepharose affinity chromatography. The second procedure replaced the latter chromatographic step with gel filtration on Sephadex G-200 and hydroxylapatite chromatography, while the third one employed instead the theoretically more efficient LBSI-Sepharose chromatographic step. The third procedure yielded purified ostrich a2AP, but the degree of purity and yield were relatively low. Ostrich plasminogen was highly purified after L-lysine-Sepharose chromatography and ostrich plasmin was obtained by the urokinase-activation of the purified ostrich plasminogen Ostrich a2AP revealed an Mr of 77-84 K and two isoelectric forms of pI 3.85 and 6.18. Nterminal sequence analysis showed ostrich a2AP to have only 2 out of 11 residues in common with both those of human and bovine a2AP. Ostrich a2AP showed the largest inhibitory effects on ostrich plasmin, followed by comm. bovine chymotrypsin, trypsin and plasmin, in that order, and it appeared to be a much less potent plasmin inhibitor than bovine aprotinin, but a much more potent one than the synthetic inhibitors, DFP and EACA. Ostrich plasminogen showed an Mr of 92 K and multiple isoelectric forms (~7) in the pI range 6.01-9.18, with a major one of pI 6.01. It showed a total of 775 amino acid residues and its N-terminal sequence showed ~53 percent identity with those of human, rabbit, cat, and ox plasminogens. Ostrich plasmin revealed an Mr of 78 K, two isoelectric forms of pI 4.07 and 6.01, and a total of 638 amino acid residues. N-terminal sequence analysis showed that 2-4 residues are identical to the 5 of human, cat, dog, rabbit, and ox plasmins. The pH and temperature optima of ostrich plasmin were determined as 8.0 and 40 oC, respectively. The thermodynamic and kinetic parameters of ostrich plasmin were computed, and plasmin was shown to prefer Lys to Arg residues in the S1 position. In conclusion, ostrich a2AP, plasminogen and plasmin showed definite similarities to their mammalian counterparts, but there were also significant differences.
- Full Text:
- Date Issued: 2000
- Authors: Thomas, Adele René
- Date: 2000
- Subjects: Serpins , Ostriches , Antifibrinolytic agents , Plasminogen , Plasmin
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11080 , http://hdl.handle.net/10948/274 , http://hdl.handle.net/10948/d1005751 , Serpins , Ostriches , Antifibrinolytic agents , Plasminogen , Plasmin
- Description: This study reports the isolation, purification and partial characterisation of the ostrich serpin, a2AP, as well as its target enzyme, ostrich plasmin, in its active and inactive proenzyme, viz. plasminogen, forms. Three different procedures were undertaken to isolate and purify ostrich a2AP. The first one involved L-lysine-Sepharose chromatography, ammonium sulfate fractionation, ion-exchange chromatography on Toyopearl Super-Q 650S, and ostrich plasminogen-Sepharose affinity chromatography. The second procedure replaced the latter chromatographic step with gel filtration on Sephadex G-200 and hydroxylapatite chromatography, while the third one employed instead the theoretically more efficient LBSI-Sepharose chromatographic step. The third procedure yielded purified ostrich a2AP, but the degree of purity and yield were relatively low. Ostrich plasminogen was highly purified after L-lysine-Sepharose chromatography and ostrich plasmin was obtained by the urokinase-activation of the purified ostrich plasminogen Ostrich a2AP revealed an Mr of 77-84 K and two isoelectric forms of pI 3.85 and 6.18. Nterminal sequence analysis showed ostrich a2AP to have only 2 out of 11 residues in common with both those of human and bovine a2AP. Ostrich a2AP showed the largest inhibitory effects on ostrich plasmin, followed by comm. bovine chymotrypsin, trypsin and plasmin, in that order, and it appeared to be a much less potent plasmin inhibitor than bovine aprotinin, but a much more potent one than the synthetic inhibitors, DFP and EACA. Ostrich plasminogen showed an Mr of 92 K and multiple isoelectric forms (~7) in the pI range 6.01-9.18, with a major one of pI 6.01. It showed a total of 775 amino acid residues and its N-terminal sequence showed ~53 percent identity with those of human, rabbit, cat, and ox plasminogens. Ostrich plasmin revealed an Mr of 78 K, two isoelectric forms of pI 4.07 and 6.01, and a total of 638 amino acid residues. N-terminal sequence analysis showed that 2-4 residues are identical to the 5 of human, cat, dog, rabbit, and ox plasmins. The pH and temperature optima of ostrich plasmin were determined as 8.0 and 40 oC, respectively. The thermodynamic and kinetic parameters of ostrich plasmin were computed, and plasmin was shown to prefer Lys to Arg residues in the S1 position. In conclusion, ostrich a2AP, plasminogen and plasmin showed definite similarities to their mammalian counterparts, but there were also significant differences.
- Full Text:
- Date Issued: 2000
The measurement of genetic diversity in mycobacterium tuberculosis using random amplified polymorphic DNA profiling
- Authors: Richner, Sharon M
- Date: 2000
- Subjects: Tuberculosis -- History -- 20th century , Tuberculosis -- Africa, Southern , Tuberculosis -- Treatment , Tuberculosis -- Africa , Tuberculosis -- Prevention , Tuberculosis -- Pathogenesis , Mycobacterium tuberculosis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4008 , http://hdl.handle.net/10962/d1004068 , Tuberculosis -- History -- 20th century , Tuberculosis -- Africa, Southern , Tuberculosis -- Treatment , Tuberculosis -- Africa , Tuberculosis -- Prevention , Tuberculosis -- Pathogenesis , Mycobacterium tuberculosis
- Description: Mycobacterium tuberculosis has caused a resurgence in pulmonary disease in both developed and developing countries in recent times, particularly amongst people infected with the human immunodeficiency virus. The disease has assumed epidemic proportions in South Africa and in the Eastern Cape Province in particular. Of further concern is the isolation of increasing numbers of multiply drug resistant strains. Knowledge of the genetic capability of this organism is essential for the successful development of novel antibiotics and vaccines in an attempt to bring the global pandemic under control. Measurement of the genetic diversity of the organism may significantly contribute to such knowledge, and is of vital importance in monitoring epidemics and in improving treatment and control of the disease. This will entail answering a number of questions related to the degree of genetic diversity amongst strains, to the difference between urban and rural strains, and between drug resistant and drug sensitive strains, and to the geographical distribution of strains. In order to establish such baseline information, RAPD profiling of a large population of isolates from the western and central regions of the Eastern Cape Province was undertaken. A smaller number of drug resistant strains from a small area of KwaZulu-Natal were also analysed, with a view to establishing the genetic difference between strains from the two provinces. Cluster analysis, analysis of molecular variance and Geographical Information Systems technology were used to analyse the RAPD profiles generated. An unexpectedly high degree of genetic diversity was detected in strains from both provinces. While no correlation was seen between genetic diversity and either urban-rural situation or geographical location, a small degree of population structure could be correlated with drug resistance in the Eastern Cape. Furthermore, a significant degree of population structure was detected between strains from the two provinces, although this was still within the parameters for conspecific populations. Future work is necessary to further characterise strains from rural areas of both provinces, as well as from the eastern region of the Eastern Cape in an attempt to pinpoint the cause of the separation of the provincial populations.
- Full Text:
- Date Issued: 2000
- Authors: Richner, Sharon M
- Date: 2000
- Subjects: Tuberculosis -- History -- 20th century , Tuberculosis -- Africa, Southern , Tuberculosis -- Treatment , Tuberculosis -- Africa , Tuberculosis -- Prevention , Tuberculosis -- Pathogenesis , Mycobacterium tuberculosis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4008 , http://hdl.handle.net/10962/d1004068 , Tuberculosis -- History -- 20th century , Tuberculosis -- Africa, Southern , Tuberculosis -- Treatment , Tuberculosis -- Africa , Tuberculosis -- Prevention , Tuberculosis -- Pathogenesis , Mycobacterium tuberculosis
- Description: Mycobacterium tuberculosis has caused a resurgence in pulmonary disease in both developed and developing countries in recent times, particularly amongst people infected with the human immunodeficiency virus. The disease has assumed epidemic proportions in South Africa and in the Eastern Cape Province in particular. Of further concern is the isolation of increasing numbers of multiply drug resistant strains. Knowledge of the genetic capability of this organism is essential for the successful development of novel antibiotics and vaccines in an attempt to bring the global pandemic under control. Measurement of the genetic diversity of the organism may significantly contribute to such knowledge, and is of vital importance in monitoring epidemics and in improving treatment and control of the disease. This will entail answering a number of questions related to the degree of genetic diversity amongst strains, to the difference between urban and rural strains, and between drug resistant and drug sensitive strains, and to the geographical distribution of strains. In order to establish such baseline information, RAPD profiling of a large population of isolates from the western and central regions of the Eastern Cape Province was undertaken. A smaller number of drug resistant strains from a small area of KwaZulu-Natal were also analysed, with a view to establishing the genetic difference between strains from the two provinces. Cluster analysis, analysis of molecular variance and Geographical Information Systems technology were used to analyse the RAPD profiles generated. An unexpectedly high degree of genetic diversity was detected in strains from both provinces. While no correlation was seen between genetic diversity and either urban-rural situation or geographical location, a small degree of population structure could be correlated with drug resistance in the Eastern Cape. Furthermore, a significant degree of population structure was detected between strains from the two provinces, although this was still within the parameters for conspecific populations. Future work is necessary to further characterise strains from rural areas of both provinces, as well as from the eastern region of the Eastern Cape in an attempt to pinpoint the cause of the separation of the provincial populations.
- Full Text:
- Date Issued: 2000
The medicinal use of some weeds, problem and alien plants in the Grahamstown and Peddie districts of the Eastern Cape, South Africa
- Dold, Anthony P, Cocks, Michelle L
- Authors: Dold, Anthony P , Cocks, Michelle L
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6514 , http://hdl.handle.net/10962/d1005942
- Description: A List of 33 medicinal plants of exotic or indigenous origin, listed as problem plants or declared weeds, is presented. The cultural uses of these plants should be taken into account when weed legislation in South Africa is considered. Of these species, six have no previous medicinal uses recorded in the literature surveyed and 21 species have additional, previously unrecorded uses. Nine previously unrecorded Xhosa names for plants are documented. Plant use categories and indigenous knowledge is discussed regarding the recorded species. The use of alien plants shows that African traditional healing is not static, but dynamic and adaptive.
- Full Text: false
- Date Issued: 2000
- Authors: Dold, Anthony P , Cocks, Michelle L
- Date: 2000
- Language: English
- Type: Article
- Identifier: vital:6514 , http://hdl.handle.net/10962/d1005942
- Description: A List of 33 medicinal plants of exotic or indigenous origin, listed as problem plants or declared weeds, is presented. The cultural uses of these plants should be taken into account when weed legislation in South Africa is considered. Of these species, six have no previous medicinal uses recorded in the literature surveyed and 21 species have additional, previously unrecorded uses. Nine previously unrecorded Xhosa names for plants are documented. Plant use categories and indigenous knowledge is discussed regarding the recorded species. The use of alien plants shows that African traditional healing is not static, but dynamic and adaptive.
- Full Text: false
- Date Issued: 2000
The nature and control of organic compounds in soda ash evaporate production
- Masemola, Patricia Mmoniemang
- Authors: Masemola, Patricia Mmoniemang
- Date: 2000
- Subjects: Organic compounds , Biotic communities , Sua Pan Soda Ash Project -- Botswana
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3902 , http://hdl.handle.net/10962/d1003961 , Organic compounds , Biotic communities , Sua Pan Soda Ash Project -- Botswana
- Description: Solar evaporite systems are man-managed ecosystems which are highly vulnerable to biological,physical and chemical disturbances. The problems encountered in such systems are in many cases found to be associated with the microbial ecology and the design of the system. This project focussed on investigating the nature of organic compounds contaminating soda ash produced at a solar evaporite production system located at Sua Pan in Botswana. Several years after the plant was commissioned, problems, including accumulation of total organic carbon (TOC) and discolouration of the soda ash product were encountered. The salt produced also retained high moisture content and was coloured pink. These phenomena impacted severely on the economic performance of the enterprise. This study was aimed at determining the origin and fate of these organic compounds within the system in order to elucidate the nature of the problem and also to conceptualise a remediation strategy suitable to reducing its impact. This was achieved by analysis of both dialysed and solvent extracts of the influent brine (well-brine), brine in the ponds (T-brine) and the bicarbonate filter cake. Although complete identification of the organic compounds isolated was not undertaken in this study, spectroscopic analysis of compounds isolated, by UV, IR, NMR and MS, strongly indicated that fulvic acids, a component of the influent well-brine organics, contribute to the organic contamination of the final product. Part of this component, however, is degraded during the ponding process. It was shown that an extracellular polysaccharide (EPS) produced by Dunaliella. spp., which proliferates in the evaporation ponds, contributes in a major way to the accumulation of TOC in the system. This was demonstrated by relating the sugar profile of carbohydrates isolated from the pond brine and final product, being arabinose, xylose, 2-o-methyl hexose, mannose, glucose and galactose. Studies reported show that EPS production was enhanced when algal cultures were exposed to stress conditions of high illumination, increasing salinity and temperature, and nitrogen limitation. Studies undertaken for the development of a remediation process for this system have shown that nutrient stripping and bacterial systems could be applied to deal with the dissolved TOC fraction, whereas adsorption systems could deal with the particulate fractions. Algal systems showed most potential for the removal of nutrients in the influent well-brine compared to chemical processes.Complete removal of ammonium and phosphorus removal efficiencies of pproximately 50% were achieved in an unoptimised pilot-scale Dunaliella-based HRAP. While similar effects were demonstrated for chemical processes, some economic constraints were noted. The potential of halophilic bacterial systems for the degradation of organic compounds in brine was also demonstrated. The limitations on the performance of such systems, associated with the low metabolic diversity, and poor immobilisation of physico-chemical processes were found to have a very low impact on the dissolved TOC fraction of the brine, the removal of the particulate material was found to result in a 35% TOC reduction in the final soda ash product and the production of a white final product.halobacteria, however, were noted. Although physico-chemical processes were found to have a very low impact on the dissolved TOC fraction of the brine, the removal of the particulate material was found to result in a 35% TOC reduction in the final soda ash product and the production of a white final product. Apart from a description of the microbial ecology of the ponds and the identification of major contributions to the TOC of the final product, a number of remediation strategies were evaluated and are described. These include chemical and biological stripping of nutrients sustaining microbial TOC production in the ponds, and also biological and physico-chemical processes for their removal once formed. Future studies to undertake the further development of these proposals has been described
- Full Text:
- Date Issued: 2000
- Authors: Masemola, Patricia Mmoniemang
- Date: 2000
- Subjects: Organic compounds , Biotic communities , Sua Pan Soda Ash Project -- Botswana
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3902 , http://hdl.handle.net/10962/d1003961 , Organic compounds , Biotic communities , Sua Pan Soda Ash Project -- Botswana
- Description: Solar evaporite systems are man-managed ecosystems which are highly vulnerable to biological,physical and chemical disturbances. The problems encountered in such systems are in many cases found to be associated with the microbial ecology and the design of the system. This project focussed on investigating the nature of organic compounds contaminating soda ash produced at a solar evaporite production system located at Sua Pan in Botswana. Several years after the plant was commissioned, problems, including accumulation of total organic carbon (TOC) and discolouration of the soda ash product were encountered. The salt produced also retained high moisture content and was coloured pink. These phenomena impacted severely on the economic performance of the enterprise. This study was aimed at determining the origin and fate of these organic compounds within the system in order to elucidate the nature of the problem and also to conceptualise a remediation strategy suitable to reducing its impact. This was achieved by analysis of both dialysed and solvent extracts of the influent brine (well-brine), brine in the ponds (T-brine) and the bicarbonate filter cake. Although complete identification of the organic compounds isolated was not undertaken in this study, spectroscopic analysis of compounds isolated, by UV, IR, NMR and MS, strongly indicated that fulvic acids, a component of the influent well-brine organics, contribute to the organic contamination of the final product. Part of this component, however, is degraded during the ponding process. It was shown that an extracellular polysaccharide (EPS) produced by Dunaliella. spp., which proliferates in the evaporation ponds, contributes in a major way to the accumulation of TOC in the system. This was demonstrated by relating the sugar profile of carbohydrates isolated from the pond brine and final product, being arabinose, xylose, 2-o-methyl hexose, mannose, glucose and galactose. Studies reported show that EPS production was enhanced when algal cultures were exposed to stress conditions of high illumination, increasing salinity and temperature, and nitrogen limitation. Studies undertaken for the development of a remediation process for this system have shown that nutrient stripping and bacterial systems could be applied to deal with the dissolved TOC fraction, whereas adsorption systems could deal with the particulate fractions. Algal systems showed most potential for the removal of nutrients in the influent well-brine compared to chemical processes.Complete removal of ammonium and phosphorus removal efficiencies of pproximately 50% were achieved in an unoptimised pilot-scale Dunaliella-based HRAP. While similar effects were demonstrated for chemical processes, some economic constraints were noted. The potential of halophilic bacterial systems for the degradation of organic compounds in brine was also demonstrated. The limitations on the performance of such systems, associated with the low metabolic diversity, and poor immobilisation of physico-chemical processes were found to have a very low impact on the dissolved TOC fraction of the brine, the removal of the particulate material was found to result in a 35% TOC reduction in the final soda ash product and the production of a white final product.halobacteria, however, were noted. Although physico-chemical processes were found to have a very low impact on the dissolved TOC fraction of the brine, the removal of the particulate material was found to result in a 35% TOC reduction in the final soda ash product and the production of a white final product. Apart from a description of the microbial ecology of the ponds and the identification of major contributions to the TOC of the final product, a number of remediation strategies were evaluated and are described. These include chemical and biological stripping of nutrients sustaining microbial TOC production in the ponds, and also biological and physico-chemical processes for their removal once formed. Future studies to undertake the further development of these proposals has been described
- Full Text:
- Date Issued: 2000
The new initiative of the East African Cooperation : opportunities, challenges and prospects
- Authors: Kimemia, Peter Njau
- Date: 2000 , 2013-04-25
- Subjects: International economic relations , Africa, East -- Foreign economic relations , East African Co-operation , Africa, East -- Economic integration
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:1041 , http://hdl.handle.net/10962/d1004743 , International economic relations , Africa, East -- Foreign economic relations , East African Co-operation , Africa, East -- Economic integration
- Description: The landmark inauguration of the East African Cooperation (EAC) on 14 March 1996 brought to the fore some key issues regarding regional economic integration in East Africa, particularly since it signalled the second attempt by Kenya, Uganda and Tanzania to form a regional economic bloc. The EAC's predecessor, the East African Community, had collapsed in 1977 in acrimonious circumstances. Prominent among the issues that led to the collapse of the East African Community was the perception of unequal gains from the integration scheme, with Uganda and Tanzania considering that disproportionate benefits were accruing to Kenya at their expense. With the new initiative, the question emerges as to whether the problems that caused the collapse of the Community will not beset the EAC and subject it to a similar fate. In an attempt to address this question, this study considers some of the theoretical issues relating to regional economic integration among countries at different levels of development, and attempts to provide an analysis of the new initiative of the EAC in the light of this theory and the history of the East African Community. The study also critically examines the objectives of the EAC and the integration strategy adopted by the three countries, and offers suggestions on the way forward. Among the arguments made in this thesis are that, contrary to the suggestions of orthodox static analysis, if the dynamic effects of integration are considered, then there may be important gains which may accrue to integrating states in the developing country context. It is also argued that different levels of development among integrating states need not necessarily be an impediment to economic integration. The study finds that, in spite of the enormous challenges facing the EAC, member states may be better off within the integration scheme than if they acted as individual units in a rapidly globalizing international system.
- Full Text:
- Date Issued: 2000
- Authors: Kimemia, Peter Njau
- Date: 2000 , 2013-04-25
- Subjects: International economic relations , Africa, East -- Foreign economic relations , East African Co-operation , Africa, East -- Economic integration
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:1041 , http://hdl.handle.net/10962/d1004743 , International economic relations , Africa, East -- Foreign economic relations , East African Co-operation , Africa, East -- Economic integration
- Description: The landmark inauguration of the East African Cooperation (EAC) on 14 March 1996 brought to the fore some key issues regarding regional economic integration in East Africa, particularly since it signalled the second attempt by Kenya, Uganda and Tanzania to form a regional economic bloc. The EAC's predecessor, the East African Community, had collapsed in 1977 in acrimonious circumstances. Prominent among the issues that led to the collapse of the East African Community was the perception of unequal gains from the integration scheme, with Uganda and Tanzania considering that disproportionate benefits were accruing to Kenya at their expense. With the new initiative, the question emerges as to whether the problems that caused the collapse of the Community will not beset the EAC and subject it to a similar fate. In an attempt to address this question, this study considers some of the theoretical issues relating to regional economic integration among countries at different levels of development, and attempts to provide an analysis of the new initiative of the EAC in the light of this theory and the history of the East African Community. The study also critically examines the objectives of the EAC and the integration strategy adopted by the three countries, and offers suggestions on the way forward. Among the arguments made in this thesis are that, contrary to the suggestions of orthodox static analysis, if the dynamic effects of integration are considered, then there may be important gains which may accrue to integrating states in the developing country context. It is also argued that different levels of development among integrating states need not necessarily be an impediment to economic integration. The study finds that, in spite of the enormous challenges facing the EAC, member states may be better off within the integration scheme than if they acted as individual units in a rapidly globalizing international system.
- Full Text:
- Date Issued: 2000
The phenomenology of the anorexic body
- Authors: Shapiro, Joel
- Date: 2000
- Subjects: Anorexia nervosa Eating disorders Anorexia nervosa -- Psychological aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3053 , http://hdl.handle.net/10962/d1002562
- Description: The purpose of the study is to articulate the phenomenology of the anorexic body. In order to describe the complex meaning of the anorexic body, the present research adopts the qualitative and exploratory approach of Seidman's (1991) in-depth phenomenologically based interviewing method. This involves a series of three separate interviews, with three research participants who have had personal experience of anorexia. The method of data analysis used is essentially on editing style of analysis (Miller and Crabtree, 1992) and is based on a hybrid of the grounded theory approach of Glaser and Strauss (1967) and Heidegger's (1927) ontological hermeneutics to form what Addison (1992) calls grounded interpretive research. Anorexic embodiment is conceptualised as precipitating a fundamental disturbance between the interactions of embodied consciousness and the world. The body is no longer taken-for-granted, and becomes an object for scrutiny. As an object, the body is experienced as a thing exterior to the self, and this awareness contributes to the sense of qisorder which permeates anorexic embodiment. Bodily intentionality is frustrated when the sphere of bodily actions and habitual acts become circumscribed. The character of lived temporality and lived spatiality are also effected with the anorexic's focus on the now, ushering in a spatiality of the here. These findings indicate that anorexic embodiment is experienced primarily as a disruption of the 'lived body' rather than that of the biological body. The prevailing discourses of anorexic embodiment are shown to be split between the naturalized discourses that provide a model of the body that is biologically determined and ahistorical, and the denaturalized discourses that provide a model of the body that is culturally constructed and lacks embodied givenness. It is argued that Merleau-Ponty's phenomenology of the body offers a renaturalization of the body that overcomes the nature/culture dichotomy of the naturalized and denaturalized discourses, thereby providing a solid foundation that more directly addresses the phenomenology of the anorexic body. The theoretical and treatment implications of Merleau-Ponty's renaturalization of the anorexic body are highlighted, and suggestions for further research are presented.
- Full Text:
- Date Issued: 2000
- Authors: Shapiro, Joel
- Date: 2000
- Subjects: Anorexia nervosa Eating disorders Anorexia nervosa -- Psychological aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3053 , http://hdl.handle.net/10962/d1002562
- Description: The purpose of the study is to articulate the phenomenology of the anorexic body. In order to describe the complex meaning of the anorexic body, the present research adopts the qualitative and exploratory approach of Seidman's (1991) in-depth phenomenologically based interviewing method. This involves a series of three separate interviews, with three research participants who have had personal experience of anorexia. The method of data analysis used is essentially on editing style of analysis (Miller and Crabtree, 1992) and is based on a hybrid of the grounded theory approach of Glaser and Strauss (1967) and Heidegger's (1927) ontological hermeneutics to form what Addison (1992) calls grounded interpretive research. Anorexic embodiment is conceptualised as precipitating a fundamental disturbance between the interactions of embodied consciousness and the world. The body is no longer taken-for-granted, and becomes an object for scrutiny. As an object, the body is experienced as a thing exterior to the self, and this awareness contributes to the sense of qisorder which permeates anorexic embodiment. Bodily intentionality is frustrated when the sphere of bodily actions and habitual acts become circumscribed. The character of lived temporality and lived spatiality are also effected with the anorexic's focus on the now, ushering in a spatiality of the here. These findings indicate that anorexic embodiment is experienced primarily as a disruption of the 'lived body' rather than that of the biological body. The prevailing discourses of anorexic embodiment are shown to be split between the naturalized discourses that provide a model of the body that is biologically determined and ahistorical, and the denaturalized discourses that provide a model of the body that is culturally constructed and lacks embodied givenness. It is argued that Merleau-Ponty's phenomenology of the body offers a renaturalization of the body that overcomes the nature/culture dichotomy of the naturalized and denaturalized discourses, thereby providing a solid foundation that more directly addresses the phenomenology of the anorexic body. The theoretical and treatment implications of Merleau-Ponty's renaturalization of the anorexic body are highlighted, and suggestions for further research are presented.
- Full Text:
- Date Issued: 2000
The political significance of Winnie-Madikazela Mandela's position in the African National Congress
- Authors: Motseta, Sello
- Date: 2000
- Subjects: African National Congress , Mandela, Winnie , South Africa -- Politics and government -- 1994-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2810 , http://hdl.handle.net/10962/d1003020 , African National Congress , Mandela, Winnie , South Africa -- Politics and government -- 1994-
- Description: Winnie Mandela has endured so many scandals over the last ten years that she has acquired a reputation for being untouchable. It is therefore ironic that there are those who feel that "the ANC want to act against Winnie not because of her human rights record, but for her outspoken criticism of the government's inability to deliver houses, thwart crime and testing our feelings on the death penalty." This assessment is instructive because in the "... turbulent years of the 1980s, she was a hero, a living martyr to the black liberation cause and despite the discomforts inflicted on her by her perpetrators, she revelled in the role" (Sparks, 1994:15). But Winnie Madikazela-Mandela, who was a Deputy Minister before being dismissed and who has had to appear before the TRC because of allegations that she was responsible for the death of teenage activist Stompie Seipei, has nevertheless been able to make a political comeback. The thesis therefore sets out to examine the rationale behind the State President's (he did not hold this title then) decision to take a considerable risk in standing by Winnie Madikazela-Mandela (they were at the time married) during her trial on charges of kidnapping in 1991. Even after her conviction, Mandela wrote that "as far as I was concerned, verdict or no verdict, her innocence was not in doubt." This unstinting loyalty was replicated elsewhere. Commenting on her acquittal on the assault charges, ANC Youth League President, Peter Mokaba, said: "What was taken away from her as a result of these false allegations must now be given back". He described the Appellate Division decision as "a political sentence" saying: "It has nothing to do with whether she was guilty or not."3 The ANC has established a practice of accommodating dissidents within its structures and has survived complex challenges during its years in exile by doing so. But political commentators are now asking whether the political cost will prove to be too great.
- Full Text:
- Date Issued: 2000
- Authors: Motseta, Sello
- Date: 2000
- Subjects: African National Congress , Mandela, Winnie , South Africa -- Politics and government -- 1994-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2810 , http://hdl.handle.net/10962/d1003020 , African National Congress , Mandela, Winnie , South Africa -- Politics and government -- 1994-
- Description: Winnie Mandela has endured so many scandals over the last ten years that she has acquired a reputation for being untouchable. It is therefore ironic that there are those who feel that "the ANC want to act against Winnie not because of her human rights record, but for her outspoken criticism of the government's inability to deliver houses, thwart crime and testing our feelings on the death penalty." This assessment is instructive because in the "... turbulent years of the 1980s, she was a hero, a living martyr to the black liberation cause and despite the discomforts inflicted on her by her perpetrators, she revelled in the role" (Sparks, 1994:15). But Winnie Madikazela-Mandela, who was a Deputy Minister before being dismissed and who has had to appear before the TRC because of allegations that she was responsible for the death of teenage activist Stompie Seipei, has nevertheless been able to make a political comeback. The thesis therefore sets out to examine the rationale behind the State President's (he did not hold this title then) decision to take a considerable risk in standing by Winnie Madikazela-Mandela (they were at the time married) during her trial on charges of kidnapping in 1991. Even after her conviction, Mandela wrote that "as far as I was concerned, verdict or no verdict, her innocence was not in doubt." This unstinting loyalty was replicated elsewhere. Commenting on her acquittal on the assault charges, ANC Youth League President, Peter Mokaba, said: "What was taken away from her as a result of these false allegations must now be given back". He described the Appellate Division decision as "a political sentence" saying: "It has nothing to do with whether she was guilty or not."3 The ANC has established a practice of accommodating dissidents within its structures and has survived complex challenges during its years in exile by doing so. But political commentators are now asking whether the political cost will prove to be too great.
- Full Text:
- 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.
- Full Text:
- Date Issued: 2000
- 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.
- Full Text:
- Date Issued: 2000
The protein requirements of the South African abalone, Haliotis midae
- Authors: Shipton, Thomas A
- Date: 2000
- Subjects: Abalones -- Nutrition Abalones -- Digestion
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5314 , http://hdl.handle.net/10962/d1005159
- Description: The potential to reduce feed formulation costs by the replacement of existing proteinsources in artificial feeds for Haliotis midae was assessed. A comparison between the efficacy of the direct method and chromic oxide marker techniques in determining apparent protein digestibility coefficients, revealed that while the former was not a suitable methodology for use with this species, the latter produced replicable and reliable results. It was established that the chromic oxide marker is inert, is not absorbed by the abalone, does not interfere with the digestive processes and moves through the intestine at the same rate to the protein. However, as this method was time consuming and expensive to implement, a multienzyme pH-stat in vitro protein digestibility technique using a three enzyme system was employed to rapidly assess the protein quality of 34 protein sources. The efficacy of the technique was established by correlating the in vitro digestibility estimates with in vivo digestibility coefficients obtained using the chromic oxide marker technique. The highest degree of in vivo predictability was attained when protein sources were separated according to origin, and significant correlations between either animal (r²=0.89, P<0.004) or plant (r²=0.79, P<0.04) protein sources were found. The effect of animal size on the qualitative protein requirements of two size classes of H.midae was assessed by feeding 12 isonitrogenous and isoenergetic single protein diets to juvenile and young adult animals (10-20 and 40-50mm shell length). The criteria for protein source selection were their bioavailability as determined using the pH-stat in vitro digestibility technique, and their cost and availability within South Africa. The protein sources identified for the trial comprised four fishmeals, casein, spirulina, abalone viscera silage, brewery waste, torula yeast, carcass, sunflower and cotton meals. The results indicated that in terms of growth and feed efficiency, the fishmeals and spirulina were the most suitable candidates as primary protein sources in formulated feeds for H.midae, and with the exceptions of the carcass meal and brewery waste, the remaining protein sources demonstrated promise as partial primary protein source replacements. The smaller size class of abalone displayed significantly reduced growth, feed and protein efficiency than their larger counterparts. In terms of feed conversion and growth response, two-way analysis of variance revealed significant interactions between protein source and animal size, suggesting that qualitative differences exist between the dietary protein requirements of the juvenile and young adult abalone. The commercial implication of thisfinding was discussed. An evaluation was undertaken to determine the effects of the partial and total replacement of dietary fishmeal with selected plant protein sources on growth and nutritional indices of juvenile H.midae. A commercial “Abfeed” formulation in which 100% of the protein component comprised LT-fishmeal was employed as a control. Fifteen isonitrogenous experimental diets were formulated in which the LT fishmeal was substituted at either 10, 15, 30, 50, 75 or 100% with either spirulina, semolina, ground maize, torula yeast, soya, sunflower or corn gluten meals or combinations thereof. No significant differences were found in the growth rates between the control diet and those diets in which 30% of the fishmeal component had been replaced by either soya, sunflower meal, or torula yeast. In addition, 50% of the fishmeal component could be substituted with either soya meal or spirulina without affecting growth. Replacement of either 75 or 100% of the fishmeal had a significant negative affect on growth. Pearson product moment correlations between dietary lysine levels and either growth rates or protein efficiency ratios revealed positive correlations (r=0.77, P=0.0005; r=0.52, P=0.04 respectively) suggesting that lysine may have been the first limiting amino acid in these diets. Carcass analysis revealed that dietary protein source had no significant effect on body composition. An assessment of the dietary arginine requirement of juvenile H.midae using whole proteins to supply graded levels of dietary arginine did not promote a growth response. It was concluded that arginine is probably not the first limiting amino acid in formulated feeds for H.midae. An assessment of the dietary lysine requirement of juvenile H.midae using two micro-encapsulation techniques (gelatin/acacia colloid or cellulose acetate phthalate) was not successful. The efficacy of the encapsulation techniques were established and an assessment of the degree of lysine supplementation undertaken. Failure of the crystalline lysine enriched diets to promote growth suggests that the prospects for using crystalline amino acids in essential amino acid requirement studies in H.midae is low. The results of the present study indicate that the prospects for replacing fishmeal with cheaper alternative protein sources in artificial feeds for H.midae is promising. Furthermore, while the technical difficulties such as the determination of the essential amino acid requirements of the abalone precluded the application of “least cost” programming, the prospects for its future application are promising.
- Full Text:
- Date Issued: 2000
- Authors: Shipton, Thomas A
- Date: 2000
- Subjects: Abalones -- Nutrition Abalones -- Digestion
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5314 , http://hdl.handle.net/10962/d1005159
- Description: The potential to reduce feed formulation costs by the replacement of existing proteinsources in artificial feeds for Haliotis midae was assessed. A comparison between the efficacy of the direct method and chromic oxide marker techniques in determining apparent protein digestibility coefficients, revealed that while the former was not a suitable methodology for use with this species, the latter produced replicable and reliable results. It was established that the chromic oxide marker is inert, is not absorbed by the abalone, does not interfere with the digestive processes and moves through the intestine at the same rate to the protein. However, as this method was time consuming and expensive to implement, a multienzyme pH-stat in vitro protein digestibility technique using a three enzyme system was employed to rapidly assess the protein quality of 34 protein sources. The efficacy of the technique was established by correlating the in vitro digestibility estimates with in vivo digestibility coefficients obtained using the chromic oxide marker technique. The highest degree of in vivo predictability was attained when protein sources were separated according to origin, and significant correlations between either animal (r²=0.89, P<0.004) or plant (r²=0.79, P<0.04) protein sources were found. The effect of animal size on the qualitative protein requirements of two size classes of H.midae was assessed by feeding 12 isonitrogenous and isoenergetic single protein diets to juvenile and young adult animals (10-20 and 40-50mm shell length). The criteria for protein source selection were their bioavailability as determined using the pH-stat in vitro digestibility technique, and their cost and availability within South Africa. The protein sources identified for the trial comprised four fishmeals, casein, spirulina, abalone viscera silage, brewery waste, torula yeast, carcass, sunflower and cotton meals. The results indicated that in terms of growth and feed efficiency, the fishmeals and spirulina were the most suitable candidates as primary protein sources in formulated feeds for H.midae, and with the exceptions of the carcass meal and brewery waste, the remaining protein sources demonstrated promise as partial primary protein source replacements. The smaller size class of abalone displayed significantly reduced growth, feed and protein efficiency than their larger counterparts. In terms of feed conversion and growth response, two-way analysis of variance revealed significant interactions between protein source and animal size, suggesting that qualitative differences exist between the dietary protein requirements of the juvenile and young adult abalone. The commercial implication of thisfinding was discussed. An evaluation was undertaken to determine the effects of the partial and total replacement of dietary fishmeal with selected plant protein sources on growth and nutritional indices of juvenile H.midae. A commercial “Abfeed” formulation in which 100% of the protein component comprised LT-fishmeal was employed as a control. Fifteen isonitrogenous experimental diets were formulated in which the LT fishmeal was substituted at either 10, 15, 30, 50, 75 or 100% with either spirulina, semolina, ground maize, torula yeast, soya, sunflower or corn gluten meals or combinations thereof. No significant differences were found in the growth rates between the control diet and those diets in which 30% of the fishmeal component had been replaced by either soya, sunflower meal, or torula yeast. In addition, 50% of the fishmeal component could be substituted with either soya meal or spirulina without affecting growth. Replacement of either 75 or 100% of the fishmeal had a significant negative affect on growth. Pearson product moment correlations between dietary lysine levels and either growth rates or protein efficiency ratios revealed positive correlations (r=0.77, P=0.0005; r=0.52, P=0.04 respectively) suggesting that lysine may have been the first limiting amino acid in these diets. Carcass analysis revealed that dietary protein source had no significant effect on body composition. An assessment of the dietary arginine requirement of juvenile H.midae using whole proteins to supply graded levels of dietary arginine did not promote a growth response. It was concluded that arginine is probably not the first limiting amino acid in formulated feeds for H.midae. An assessment of the dietary lysine requirement of juvenile H.midae using two micro-encapsulation techniques (gelatin/acacia colloid or cellulose acetate phthalate) was not successful. The efficacy of the encapsulation techniques were established and an assessment of the degree of lysine supplementation undertaken. Failure of the crystalline lysine enriched diets to promote growth suggests that the prospects for using crystalline amino acids in essential amino acid requirement studies in H.midae is low. The results of the present study indicate that the prospects for replacing fishmeal with cheaper alternative protein sources in artificial feeds for H.midae is promising. Furthermore, while the technical difficulties such as the determination of the essential amino acid requirements of the abalone precluded the application of “least cost” programming, the prospects for its future application are promising.
- Full Text:
- Date Issued: 2000
The psychological role of homoeroticism in the spiritual growth of priests: a study of individuation processes and homoerotic sexualities
- Authors: Taute, Harold Graeme
- Date: 2000
- Subjects: Homosexuality -- Psychological aspects Homosexuality -- Religious aspects -- Christianity
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3069 , http://hdl.handle.net/10962/d1002578
- Description: The study explored the psychological role of homoeroticism in the spiritual growth of priests, using Grounded Theory and James Fowler’s stages of faith development as the basis for the research methodology. Three Anglican priests were interviewed using a semi-structured interview format. The research interview combined Fowler’s Faith Development Interview Guide and a semi-structured interview in order to ascertain the priests’ level of spiritual development, as well as to explore their experience of the homoerotic component to their sexuality, and its influence on their spiritual growth. The interviews and iterative analysis focussed on four major questions: (1) Are priests who experience and actively work at integrating the homoerotic aspect to themselves assisted thereby in their spiritual growth, and if so, how might this be accounted for?; (2) Following Fowler’s model of spiritual development, what processes characterise each priest’s approach to meaning-creation in their lives?; (3) Following Fowler’s model, can the psychological work of engaging with and accepting homoeroticism be conceived of as serving an initiatory function in the emergence of new processes of meaning-creation?; (4) What role does homoeroticism serve in the spiritual growth of priests? The interpretative phase consisted of three stages. A grounded theory analysis of each interview was undertaken, developing a model for understanding the role of homoeroticism in spiritual growth. In the second stage, the priest’s level of spiritual development was ascertained, using Fowler’s Faith Development Guide. The third stage linked each participant’s level of spiritual development (in Fowler’s terms) with their core stories regarding experiences, meanings, and roles of homoeroticism. Finally, an integrative theory of the role of homoeroticism in spiritual growth was developed, using Jungian and post-Jungian theory as a basis for the discussion. The results suggested that homoeroticism did not play any role in spiritual growth and individuation separate to the manner in which it was experienced as having been constructed by society and the Church, and separate to the manner in which each priest in the study expressed, experienced, or engaged with it. In this context the experience of homoeroticism appeared to play a diversity of roles, including representing the collective and personal shadow, the archetypal anima/animus, the archetypal puer/senex constellation, the transcendent function, and thereby, as an expression of these roles, contribute to the emergence of new processes of meaning-creation in the spiritual growth and individuation of priests.
- Full Text:
- Date Issued: 2000
- Authors: Taute, Harold Graeme
- Date: 2000
- Subjects: Homosexuality -- Psychological aspects Homosexuality -- Religious aspects -- Christianity
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3069 , http://hdl.handle.net/10962/d1002578
- Description: The study explored the psychological role of homoeroticism in the spiritual growth of priests, using Grounded Theory and James Fowler’s stages of faith development as the basis for the research methodology. Three Anglican priests were interviewed using a semi-structured interview format. The research interview combined Fowler’s Faith Development Interview Guide and a semi-structured interview in order to ascertain the priests’ level of spiritual development, as well as to explore their experience of the homoerotic component to their sexuality, and its influence on their spiritual growth. The interviews and iterative analysis focussed on four major questions: (1) Are priests who experience and actively work at integrating the homoerotic aspect to themselves assisted thereby in their spiritual growth, and if so, how might this be accounted for?; (2) Following Fowler’s model of spiritual development, what processes characterise each priest’s approach to meaning-creation in their lives?; (3) Following Fowler’s model, can the psychological work of engaging with and accepting homoeroticism be conceived of as serving an initiatory function in the emergence of new processes of meaning-creation?; (4) What role does homoeroticism serve in the spiritual growth of priests? The interpretative phase consisted of three stages. A grounded theory analysis of each interview was undertaken, developing a model for understanding the role of homoeroticism in spiritual growth. In the second stage, the priest’s level of spiritual development was ascertained, using Fowler’s Faith Development Guide. The third stage linked each participant’s level of spiritual development (in Fowler’s terms) with their core stories regarding experiences, meanings, and roles of homoeroticism. Finally, an integrative theory of the role of homoeroticism in spiritual growth was developed, using Jungian and post-Jungian theory as a basis for the discussion. The results suggested that homoeroticism did not play any role in spiritual growth and individuation separate to the manner in which it was experienced as having been constructed by society and the Church, and separate to the manner in which each priest in the study expressed, experienced, or engaged with it. In this context the experience of homoeroticism appeared to play a diversity of roles, including representing the collective and personal shadow, the archetypal anima/animus, the archetypal puer/senex constellation, the transcendent function, and thereby, as an expression of these roles, contribute to the emergence of new processes of meaning-creation in the spiritual growth and individuation of priests.
- Full Text:
- Date Issued: 2000
The Raven's Coloured Progressive Matrices Test: a pilot study for the establishment of normative data for Xhosa-speaking primary school pupils in the Grahamstown region
- Authors: Bass, Natalie Tanyia
- Date: 2000
- Subjects: Raven's Progressive Matrices , Students -- South Africa -- Psychology , Educational tests and measurements -- South Africa , Intelligence levels -- South Africa , Students -- Psychology
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2930 , http://hdl.handle.net/10962/d1002439 , Raven's Progressive Matrices , Students -- South Africa -- Psychology , Educational tests and measurements -- South Africa , Intelligence levels -- South Africa , Students -- Psychology
- Description: The Raven’s Coloured Progressive Matrices (CPM) test is used extensively across a wide variety of settings in South Africa, however more appropriate local normative data has yet to be established. The CPM is internationally recognised as a culture-fair test of nonverbal intelligence, designed for use with children between the ages of 5½ and 11½. This pilot study thus sought to establish normative data for this instrument for a population of Xhosa-speaking Primary School children in the peri-urban township area in the Grahamstown region. The booklet version of the test was used and it was administered in group format and according to an alternate method of test administration (using Xhosa instructions) developed by Vass in 1992. The final normative sample consisted of 197 male and 182 female Xhosa-speaking children in Grades Two to Seven (N=379). The results showed (1) a significant effect of age on test scores, where scores increased with age as expected; (2) a consistent tendency for males to outperform females was also noted, however small sample sizes precluded any categorical claims to this effect; (3) no significant effect of education on test scores was observed and finally; (4) and finally, it appeared that the norms generated for this study revealed a tendency to be lower than those obtained by Raven, Court and Raven (1990) during the standardisation of this instrument in the United Kingdom and America. The study concluded that (1) there is an urgent need for more appropriate South African normative data for this test; and (2) that when assessing African children from disadvantaged backgrounds, further research into the effects of cultural and socio-economic factors and gender on non-verbal intelligence (and on performance on this test in particular) is required.
- Full Text:
- Date Issued: 2000
- Authors: Bass, Natalie Tanyia
- Date: 2000
- Subjects: Raven's Progressive Matrices , Students -- South Africa -- Psychology , Educational tests and measurements -- South Africa , Intelligence levels -- South Africa , Students -- Psychology
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2930 , http://hdl.handle.net/10962/d1002439 , Raven's Progressive Matrices , Students -- South Africa -- Psychology , Educational tests and measurements -- South Africa , Intelligence levels -- South Africa , Students -- Psychology
- Description: The Raven’s Coloured Progressive Matrices (CPM) test is used extensively across a wide variety of settings in South Africa, however more appropriate local normative data has yet to be established. The CPM is internationally recognised as a culture-fair test of nonverbal intelligence, designed for use with children between the ages of 5½ and 11½. This pilot study thus sought to establish normative data for this instrument for a population of Xhosa-speaking Primary School children in the peri-urban township area in the Grahamstown region. The booklet version of the test was used and it was administered in group format and according to an alternate method of test administration (using Xhosa instructions) developed by Vass in 1992. The final normative sample consisted of 197 male and 182 female Xhosa-speaking children in Grades Two to Seven (N=379). The results showed (1) a significant effect of age on test scores, where scores increased with age as expected; (2) a consistent tendency for males to outperform females was also noted, however small sample sizes precluded any categorical claims to this effect; (3) no significant effect of education on test scores was observed and finally; (4) and finally, it appeared that the norms generated for this study revealed a tendency to be lower than those obtained by Raven, Court and Raven (1990) during the standardisation of this instrument in the United Kingdom and America. The study concluded that (1) there is an urgent need for more appropriate South African normative data for this test; and (2) that when assessing African children from disadvantaged backgrounds, further research into the effects of cultural and socio-economic factors and gender on non-verbal intelligence (and on performance on this test in particular) is required.
- Full Text:
- Date Issued: 2000