Measuring changes in residential segregation in Port Elizabeth, South Africa, from 1996-2011
- Authors: Odayar, Luveshni
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3641 , vital:20532
- Description: Racial segregation and inequality were the prime objectives of the colonial and apartheid spatial planning policies that governed the spatial development of the South African urban landscape. Since South Africa’s democratic transition after 1994, efforts have been made by government to facilitate racial integration and transform the apartheid urban fabric. Research into post-apartheid segregation is crucial to assess the success of governmental actions enacted thus far, while informing future spatial planning strategies. Most studies of these processes have relied solely on dichotomous indices to measure the extent of segregation between two groups. Few have utilized multi-group indices, which are more suited to investigating changes in multi-ethnic cases. Furthermore, the segregation indices used are typically aspatial. This study investigates the extent to which the segregationist legacy prevails in Port Elizabeth, a place widely considered to be the founding city of urban racial segregation. It also aims to investigate the impact of geographical scale on segregation. Theil’s multi-group Entropy Index and Duncan and Duncan’s Dissimilarity Index were derived from racial population data from the 1996, 2001 and 2011 National Censuses, and GIS was used to map changes in racial diversity both at tract level and across a range of geographical scales. To generate a more holistic understanding of the observed trends, statistical tests were performed to relate the observed patterns to socio-economic determinants, and feedback from the relevant government department was obtained. The results from the entropy indices reveal that segregation levels in Port Elizabeth have declined but still remain high: 84.6 % (1996), 79.2 % (2001) to 71.5 % (2011). This is a similar trend to those found in Cape Town and Johannesburg. The integration that did occur was characterized by one-way patterns of movement into former-White areas; this was predominantly confined to the Indian population, and to a lesser extent, the Coloured population. The vast majority of the African population remains confined to their former designated location areas. The White population remains the most segregated group, despite most of the racial integration occurring in former-White areas. Interview results and statistical tests revealed that persisting racial discrepancies in socio-economic factors (income, employment and education) can be considered major drivers influencing the observed trends in racial integration and persisting desegregation, as well as self-segregation.
- Full Text:
- Authors: Odayar, Luveshni
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3641 , vital:20532
- Description: Racial segregation and inequality were the prime objectives of the colonial and apartheid spatial planning policies that governed the spatial development of the South African urban landscape. Since South Africa’s democratic transition after 1994, efforts have been made by government to facilitate racial integration and transform the apartheid urban fabric. Research into post-apartheid segregation is crucial to assess the success of governmental actions enacted thus far, while informing future spatial planning strategies. Most studies of these processes have relied solely on dichotomous indices to measure the extent of segregation between two groups. Few have utilized multi-group indices, which are more suited to investigating changes in multi-ethnic cases. Furthermore, the segregation indices used are typically aspatial. This study investigates the extent to which the segregationist legacy prevails in Port Elizabeth, a place widely considered to be the founding city of urban racial segregation. It also aims to investigate the impact of geographical scale on segregation. Theil’s multi-group Entropy Index and Duncan and Duncan’s Dissimilarity Index were derived from racial population data from the 1996, 2001 and 2011 National Censuses, and GIS was used to map changes in racial diversity both at tract level and across a range of geographical scales. To generate a more holistic understanding of the observed trends, statistical tests were performed to relate the observed patterns to socio-economic determinants, and feedback from the relevant government department was obtained. The results from the entropy indices reveal that segregation levels in Port Elizabeth have declined but still remain high: 84.6 % (1996), 79.2 % (2001) to 71.5 % (2011). This is a similar trend to those found in Cape Town and Johannesburg. The integration that did occur was characterized by one-way patterns of movement into former-White areas; this was predominantly confined to the Indian population, and to a lesser extent, the Coloured population. The vast majority of the African population remains confined to their former designated location areas. The White population remains the most segregated group, despite most of the racial integration occurring in former-White areas. Interview results and statistical tests revealed that persisting racial discrepancies in socio-economic factors (income, employment and education) can be considered major drivers influencing the observed trends in racial integration and persisting desegregation, as well as self-segregation.
- Full Text:
Meat and its meanings: representations of meat-eating in selected works of South African literature
- Authors: Coetzer, Theo
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3860 , vital:20550
- Description: This thesis is situated within the burgeoning field of literary animal studies. Its aim is to analyse critically the way in which animals-as-meat are represented in South African literature. While meat pervades our lives and literature, there exists very little scholarship that considers literary depictions of meat. The thesis suggests that literary texts can offer useful reflections of the cultural environments in which they are immersed and, furthermore, can encourage what J. M. Coetzee calls the ‘sympathetic imagination’ in relation to animals. The dissertation offers close readings of three primary texts, while also drawing on a broader range of local fiction. Chapter 1 discusses Eben Venter’s Trencherman, with a specific focus on Venter’s use of the plaasroman and literary dystopia. Both genres are important to the novel’s ubiquitous depictions of meat, serving to illustrate some of the destructive, and irreversible, excesses associated with traditional Afrikaner culture in South Africa. Meat consumption is not only depicted as being among these harmful excesses, but also comes to represent them collectively. Chapter 2 offers a reading of Zakes Mda’s The Madonna of Excelsior, paying particular attention to its representation of the intersection between the objectification of women’s bodies and the transformation of animals into meat. In my approach to this text, I make use of Carol J. Adams’ notion of the ‘absent referent’. I suggest that while Mda ostensibly considers the subjugation of both women and animals, the novel does not ultimately demonstrate concern for animals in their own right. The final chapter considers the representation of suffering in Damon Galgut’s The Beautiful Screaming of Pigs. I argue that Galgut’s text is alone among the three primary texts in its attention to the animal suffering inextricably linked to meat production. The novel depicts this suffering as being comparable to human suffering, while simultaneously demonstrating humans’ indifference to their animal fellows. The dissertation concludes that while meat is infused with a range of meanings in South African literature, the most obvious and intrinsic one – the fact of animal death and animal suffering – is the one most often ignored.
- Full Text:
- Authors: Coetzer, Theo
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3860 , vital:20550
- Description: This thesis is situated within the burgeoning field of literary animal studies. Its aim is to analyse critically the way in which animals-as-meat are represented in South African literature. While meat pervades our lives and literature, there exists very little scholarship that considers literary depictions of meat. The thesis suggests that literary texts can offer useful reflections of the cultural environments in which they are immersed and, furthermore, can encourage what J. M. Coetzee calls the ‘sympathetic imagination’ in relation to animals. The dissertation offers close readings of three primary texts, while also drawing on a broader range of local fiction. Chapter 1 discusses Eben Venter’s Trencherman, with a specific focus on Venter’s use of the plaasroman and literary dystopia. Both genres are important to the novel’s ubiquitous depictions of meat, serving to illustrate some of the destructive, and irreversible, excesses associated with traditional Afrikaner culture in South Africa. Meat consumption is not only depicted as being among these harmful excesses, but also comes to represent them collectively. Chapter 2 offers a reading of Zakes Mda’s The Madonna of Excelsior, paying particular attention to its representation of the intersection between the objectification of women’s bodies and the transformation of animals into meat. In my approach to this text, I make use of Carol J. Adams’ notion of the ‘absent referent’. I suggest that while Mda ostensibly considers the subjugation of both women and animals, the novel does not ultimately demonstrate concern for animals in their own right. The final chapter considers the representation of suffering in Damon Galgut’s The Beautiful Screaming of Pigs. I argue that Galgut’s text is alone among the three primary texts in its attention to the animal suffering inextricably linked to meat production. The novel depicts this suffering as being comparable to human suffering, while simultaneously demonstrating humans’ indifference to their animal fellows. The dissertation concludes that while meat is infused with a range of meanings in South African literature, the most obvious and intrinsic one – the fact of animal death and animal suffering – is the one most often ignored.
- Full Text:
Mesopredator release and the effectiveness of camera traps for estimating mammal abundances in the Eastern Cape, South Africa
- Authors: Taylor, Jonathan Michael
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3587 , vital:20527
- Description: Remotely operated cameras (camera traps) have become an indispensable tool for many ecologists, particularly those studying rare and elusive animals. A plethora of camera trap makes and models are now commercially available, yet the effects of their varying design features on the quality and quantity of data recorded remains principally unknown. Better understanding of differing camera trap designs is needed before adequate management policies can be implemented, especially when the aim is to protect vulnerable and endangered species such as many carnivores. Habitat loss and human conflict has prompted worldwide declines of apex predator populations. Following this, many smaller predators have undergone population ‘explosions’ due to the lack of top-down forcing, a phenomenon known as mesopredator release. Land use changes in the Eastern Cape of South Africa have caused extensive degradation and fragmentation of the Subtropical Thicket Biome. In addition, coupled with anthropogenic persecution, apex predators including lions (Panthera leo), leopards (P. pardus), and brown hyaenas (Hyaena brunnea) have been extirpated from large areas of their historic range. Removal of these apex predators may provide opportunity for mesopredators, such as black-backed jackals (Canis mesomelas) and caracals (Caracal caracal), to be released from top-down forcing and possibly initiate trophic cascade effects. Therefore, using randomly distributed camera traps, my study aimed to explore the quality and quantity of data collected by different camera trap designs, and to investigate the mesopredator release hypothesis in the Eastern Cape of South Africa. A total of 2,989 trap nights was used to compare camera trap designs. Camera traps with narrow detection zones and fast trigger speeds (≤ 0.25 seconds) recorded a higher diversity of carnivores, but there was no significant difference in the relative abundances of carnivore species recorded by different camera trap models. A total of 19,659 trap nights was used to assess mesopredator relative abundance, occupancy, distribution and daily activity patterns at one site with, and one site without, apex predators. Consistent with the mesopredator release hypothesis, black-backed jackal relative abundance was significantly higher in the absence of apex predators, and this was supported by occupancy analyses. Further, black-backed jackal distribution was significantly concentrated in areas where apex predator activity was low, possibly indicating spatial avoidance. There was no significant difference in caracal relative abundance, occupancy, distribution, or daily activity between sites. These results provide the first indication of mesopredator release of blackbacked jackals in the Eastern Cape. The implications of black-backed jackal release including prey population structure, local extinctions, altered seed dispersal and disease dynamics are discussed.
- Full Text:
- Authors: Taylor, Jonathan Michael
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3587 , vital:20527
- Description: Remotely operated cameras (camera traps) have become an indispensable tool for many ecologists, particularly those studying rare and elusive animals. A plethora of camera trap makes and models are now commercially available, yet the effects of their varying design features on the quality and quantity of data recorded remains principally unknown. Better understanding of differing camera trap designs is needed before adequate management policies can be implemented, especially when the aim is to protect vulnerable and endangered species such as many carnivores. Habitat loss and human conflict has prompted worldwide declines of apex predator populations. Following this, many smaller predators have undergone population ‘explosions’ due to the lack of top-down forcing, a phenomenon known as mesopredator release. Land use changes in the Eastern Cape of South Africa have caused extensive degradation and fragmentation of the Subtropical Thicket Biome. In addition, coupled with anthropogenic persecution, apex predators including lions (Panthera leo), leopards (P. pardus), and brown hyaenas (Hyaena brunnea) have been extirpated from large areas of their historic range. Removal of these apex predators may provide opportunity for mesopredators, such as black-backed jackals (Canis mesomelas) and caracals (Caracal caracal), to be released from top-down forcing and possibly initiate trophic cascade effects. Therefore, using randomly distributed camera traps, my study aimed to explore the quality and quantity of data collected by different camera trap designs, and to investigate the mesopredator release hypothesis in the Eastern Cape of South Africa. A total of 2,989 trap nights was used to compare camera trap designs. Camera traps with narrow detection zones and fast trigger speeds (≤ 0.25 seconds) recorded a higher diversity of carnivores, but there was no significant difference in the relative abundances of carnivore species recorded by different camera trap models. A total of 19,659 trap nights was used to assess mesopredator relative abundance, occupancy, distribution and daily activity patterns at one site with, and one site without, apex predators. Consistent with the mesopredator release hypothesis, black-backed jackal relative abundance was significantly higher in the absence of apex predators, and this was supported by occupancy analyses. Further, black-backed jackal distribution was significantly concentrated in areas where apex predator activity was low, possibly indicating spatial avoidance. There was no significant difference in caracal relative abundance, occupancy, distribution, or daily activity between sites. These results provide the first indication of mesopredator release of blackbacked jackals in the Eastern Cape. The implications of black-backed jackal release including prey population structure, local extinctions, altered seed dispersal and disease dynamics are discussed.
- Full Text:
Mesoscale mechanisms of larval transport and settlement in relation to physical factors off the south coast of South Africa: a topographic approach
- Authors: Mian, Shana Iva
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5947 , http://hdl.handle.net/10962/d1020844
- Description: The majority of benthic marine invertebrate life cycles include a meroplanktonic phase. Most marine biologists recognise that this stage could play an important role in dispersal, especially for sedentary or sessile organisms. Recent studies on larval dispersal have found that dispersal does not occur to the extent that was previously believed. Some larvae instead remain close to their natal populations through larval nearshore retention mechanisms, both active and passive. This study attempted to a) describe nearshore distribution patterns of several intertidal larvae in relation to nearshore hydrodynamics, b) infer whether larvae are active or passive in the water column and whether this differs among taxa and c) compare pelagic mussel larval abundance with settlement rates, at 2 bay and 2 open coast sites on the south coast of South Africa to note any topographical effects. At each of the four sites, pelagic samples were collected along 2 transects. Larvae and current speed data were collected at various depths (surface, mid-depth and bottom) at distances of 200, 400, 900 and 2400m offshore of the coast. Settlement samples were collected at sites that were onshore of the pelagic transects using plastic souring pads following previous studies. Pelagic larval distribution showed no effect of topography. Instead larval abundance was highly variable among sample periods and among different taxa. Slow swimming D-stage mussel larvae were found to be positively correlated with both upwelling and turbulence indices suggesting that they behave as passive particles in the water column. The abundances of larval taxa with faster swimming speeds than the D-larvae were negatively correlated with upwelling and did not correlate with turbulence. This suggests that these larvae are more active within the water column than the D-larvae which would theoretically allow them to maintain their position in the water column. Further analysis revealed that mean larval depth correlated with mean depth of shoreward moving water masses regardless of the state of upwelling. These results suggest that larvae were actively selecting the depth at which they were found presumably in order to associate themselves with shoreward moving currents. This interpretation was supported by ontogenetic patterns in the behaviour of barnacle larvae, the nauplii of which were found further offshore as they aged, and closer onshore again once they reach the faster swimming cyprid stage. Although there was no detectable effect of topography on the abundances of planktonic larvae, the settlement section of this study revealed an effect of topography, with higher settlement and recruitment rates at bay sites than at the open coast sites. Settlement rates were seen to be negatively correlated with turbulence at bay sites but not open coast sites. Recruitment rates for each sample event were positively correlated with upwelling at each site. This study found pelagic larvae to be generally active within the water column which allowed them to remain close to the shore regardless of topography and upwelling/turbulence regimes. Although meaningful correlation analyses between pelagic larval supply and settlement rates could not be conducted due to loss of settlement collectors, settlement rates were affected by local topography with higher settlement and recruitment in bay sites.
- Full Text:
- Authors: Mian, Shana Iva
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5947 , http://hdl.handle.net/10962/d1020844
- Description: The majority of benthic marine invertebrate life cycles include a meroplanktonic phase. Most marine biologists recognise that this stage could play an important role in dispersal, especially for sedentary or sessile organisms. Recent studies on larval dispersal have found that dispersal does not occur to the extent that was previously believed. Some larvae instead remain close to their natal populations through larval nearshore retention mechanisms, both active and passive. This study attempted to a) describe nearshore distribution patterns of several intertidal larvae in relation to nearshore hydrodynamics, b) infer whether larvae are active or passive in the water column and whether this differs among taxa and c) compare pelagic mussel larval abundance with settlement rates, at 2 bay and 2 open coast sites on the south coast of South Africa to note any topographical effects. At each of the four sites, pelagic samples were collected along 2 transects. Larvae and current speed data were collected at various depths (surface, mid-depth and bottom) at distances of 200, 400, 900 and 2400m offshore of the coast. Settlement samples were collected at sites that were onshore of the pelagic transects using plastic souring pads following previous studies. Pelagic larval distribution showed no effect of topography. Instead larval abundance was highly variable among sample periods and among different taxa. Slow swimming D-stage mussel larvae were found to be positively correlated with both upwelling and turbulence indices suggesting that they behave as passive particles in the water column. The abundances of larval taxa with faster swimming speeds than the D-larvae were negatively correlated with upwelling and did not correlate with turbulence. This suggests that these larvae are more active within the water column than the D-larvae which would theoretically allow them to maintain their position in the water column. Further analysis revealed that mean larval depth correlated with mean depth of shoreward moving water masses regardless of the state of upwelling. These results suggest that larvae were actively selecting the depth at which they were found presumably in order to associate themselves with shoreward moving currents. This interpretation was supported by ontogenetic patterns in the behaviour of barnacle larvae, the nauplii of which were found further offshore as they aged, and closer onshore again once they reach the faster swimming cyprid stage. Although there was no detectable effect of topography on the abundances of planktonic larvae, the settlement section of this study revealed an effect of topography, with higher settlement and recruitment rates at bay sites than at the open coast sites. Settlement rates were seen to be negatively correlated with turbulence at bay sites but not open coast sites. Recruitment rates for each sample event were positively correlated with upwelling at each site. This study found pelagic larvae to be generally active within the water column which allowed them to remain close to the shore regardless of topography and upwelling/turbulence regimes. Although meaningful correlation analyses between pelagic larval supply and settlement rates could not be conducted due to loss of settlement collectors, settlement rates were affected by local topography with higher settlement and recruitment in bay sites.
- Full Text:
Movement patterns of Cape stumpnose, Rhabdosargus holubi (Sparidae), in the Kowie Estuary, South Africa
- Authors: Grant, Gareth Neil
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/982 , vital:20010
- Description: Rhabdosargus holubi is an ubiquitous estuary-dependent fishery species endemic to southern Africa. Although aspects of its recruitment dynamics from sea to estuary have received considerable research attention, little is known about its movement behaviour within estuarine systems. Fishery surveys have also revealed that R. holubi is a dominant species in catches within several temperate estuaries in South Africa. Therefore, investigating movement behaviour is fundamental to understanding the ecology of this species and providing a means for implementing effective fisheries management strategies. This study made use of passive acoustic telemetry to quantify the movement patterns of juvenile R. holubi in the Kowie Estuary, in the Eastern Cape Province of South Africa. Previous studies have revealed that surgically implanted transmitters may have adverse effects on the physiology and behaviour of tagged fish. Therefore, due to the small size of juvenile R. holubi, an a priori transmitter-effect experiment was undertaken. This experiment revealed that juvenile R. holubi (146-217 mm fork length) were not adversely affected by the surgical implantation of acoustic transmitters (7 mm Ø, 1.6 g out of water) and hence acoustic telemetry was well suited to monitoring the movements of this species. A 4-month telemetry study evaluated the movement patterns of 21 juveniles (140-190 mm fork length) tagged in three equal batches along the length of the estuary. Specific aspects of their movement included space use patterns, habitat connectivity, and the influences of geophysical cycles and environmental variables. Tagged fish exhibited high residency, which varied between each release site area. The mean length of estuary used was greater for the upper batch (15.65 ± 6.49 km) than the middle and lower batches (7.36 ± 3.68 and 2.67 ± 2 km, respectively). In terms of habitat connectivity, once the tagged fish left the estuary, they generally did not return. Tagged R. holubi spent the majority (83%) of their monitoring periods within the estuarine environment, with the sea (16%) and riverine (1%) environments being utilised to a lesser extent. Diel and tidal cycles influenced the movement patterns of juvenile R. holubi. However, the high levels of residency meant that fine-scale movements were difficult to detect due to the acoustic receiver deployment configuration (i.e. receivers moored one kilometer apart). The influence of environmental variables on the movement of individuals, modelled with general linear mixed models (GLMMs), revealed that the effects of river inflow and water temperature were greatest. Increased river inflow caused individuals to use larger portions of the estuary. Increased water temperature, particularly river temperature, caused individuals to shift their distributions downstream (towards the mouth of the estuary). This study highlighted the importance of estuarine nursery habitats to R. holubi, suggesting that a loss or reduction of healthy estuarine habitats may lead to significant declines in the abundance of this species. Furthermore, extreme resident behaviour suggests that no-take area closures (estuarine protected areas) would be an effective management strategy for this important fishery species.
- Full Text:
- Authors: Grant, Gareth Neil
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/982 , vital:20010
- Description: Rhabdosargus holubi is an ubiquitous estuary-dependent fishery species endemic to southern Africa. Although aspects of its recruitment dynamics from sea to estuary have received considerable research attention, little is known about its movement behaviour within estuarine systems. Fishery surveys have also revealed that R. holubi is a dominant species in catches within several temperate estuaries in South Africa. Therefore, investigating movement behaviour is fundamental to understanding the ecology of this species and providing a means for implementing effective fisheries management strategies. This study made use of passive acoustic telemetry to quantify the movement patterns of juvenile R. holubi in the Kowie Estuary, in the Eastern Cape Province of South Africa. Previous studies have revealed that surgically implanted transmitters may have adverse effects on the physiology and behaviour of tagged fish. Therefore, due to the small size of juvenile R. holubi, an a priori transmitter-effect experiment was undertaken. This experiment revealed that juvenile R. holubi (146-217 mm fork length) were not adversely affected by the surgical implantation of acoustic transmitters (7 mm Ø, 1.6 g out of water) and hence acoustic telemetry was well suited to monitoring the movements of this species. A 4-month telemetry study evaluated the movement patterns of 21 juveniles (140-190 mm fork length) tagged in three equal batches along the length of the estuary. Specific aspects of their movement included space use patterns, habitat connectivity, and the influences of geophysical cycles and environmental variables. Tagged fish exhibited high residency, which varied between each release site area. The mean length of estuary used was greater for the upper batch (15.65 ± 6.49 km) than the middle and lower batches (7.36 ± 3.68 and 2.67 ± 2 km, respectively). In terms of habitat connectivity, once the tagged fish left the estuary, they generally did not return. Tagged R. holubi spent the majority (83%) of their monitoring periods within the estuarine environment, with the sea (16%) and riverine (1%) environments being utilised to a lesser extent. Diel and tidal cycles influenced the movement patterns of juvenile R. holubi. However, the high levels of residency meant that fine-scale movements were difficult to detect due to the acoustic receiver deployment configuration (i.e. receivers moored one kilometer apart). The influence of environmental variables on the movement of individuals, modelled with general linear mixed models (GLMMs), revealed that the effects of river inflow and water temperature were greatest. Increased river inflow caused individuals to use larger portions of the estuary. Increased water temperature, particularly river temperature, caused individuals to shift their distributions downstream (towards the mouth of the estuary). This study highlighted the importance of estuarine nursery habitats to R. holubi, suggesting that a loss or reduction of healthy estuarine habitats may lead to significant declines in the abundance of this species. Furthermore, extreme resident behaviour suggests that no-take area closures (estuarine protected areas) would be an effective management strategy for this important fishery species.
- Full Text:
Nanocomposites of carbon nanomaterials and metallophthalocyanines : applications towards electrocatalysis
- Authors: Nyoni, Stephen
- Date: 2016
- Subjects: Nanocomposites (Materials) , Nanostructured materials , Electrocatalysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4561 , http://hdl.handle.net/10962/d1020846
- Description: Nanohybrid materials have been prepared and examined for their electrocatalytic activity. The nanocomposites have been prepared from carbon nanomaterials (multiwalled carbon nanotubes (MWCNTs) and graphene nanosheets), cadmium selenide quantum dots and metallophthalocyanines (MPcs). The MPcs used in this work are cobalt tetraamino-phthalocyanine (CoTAPc) and tetra (4-(4,6-diaminopyrimidin-2-ylthio) phthalocyaninatocobalt (II)) (CoPyPc). Their activity has also been explored in different forms; polymeric MPcs, iodine doped MPcs and covalently linked MPcs. The premixed drop-dry, sequential drop-dry and electropolymerisation electrode modification techniques were used to prepare nanocomposite catalysts on the glassy carbon electrode (GCE) surface. The sequential drop dry technique for MPc and MWCNTs gave better catalytic responses in terms of limit of detection, catalytic and electron transfer rate constants relative to the premixed. MWCNTs and CdSe-QDs have been used as intercalating agents to reduce restacking of graphene nanosheets during nanocomposite preparation. Voltammetry, chronoamperometry, scanning electrochemical microscopy and electrochemical impedance spectroscopy methods are used for electrochemical characterization modified GCE. X-ray photoelectron spectroscopy, X-ray diffractometry, transmission electron microscopy, scanning electron microscopy, infra-red spectroscopy, Raman spectroscopy were used to explore surface functionalities, morphology and topography of the nanocomposites. Electrocatalytic activity and possible applications of the modified electrodes were tested using oxygen reduction reaction, l-cysteine oxidation and paraquat reduction. Activity of nanocomposites was found superior over individual nanomaterials in these applications.
- Full Text:
- Authors: Nyoni, Stephen
- Date: 2016
- Subjects: Nanocomposites (Materials) , Nanostructured materials , Electrocatalysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4561 , http://hdl.handle.net/10962/d1020846
- Description: Nanohybrid materials have been prepared and examined for their electrocatalytic activity. The nanocomposites have been prepared from carbon nanomaterials (multiwalled carbon nanotubes (MWCNTs) and graphene nanosheets), cadmium selenide quantum dots and metallophthalocyanines (MPcs). The MPcs used in this work are cobalt tetraamino-phthalocyanine (CoTAPc) and tetra (4-(4,6-diaminopyrimidin-2-ylthio) phthalocyaninatocobalt (II)) (CoPyPc). Their activity has also been explored in different forms; polymeric MPcs, iodine doped MPcs and covalently linked MPcs. The premixed drop-dry, sequential drop-dry and electropolymerisation electrode modification techniques were used to prepare nanocomposite catalysts on the glassy carbon electrode (GCE) surface. The sequential drop dry technique for MPc and MWCNTs gave better catalytic responses in terms of limit of detection, catalytic and electron transfer rate constants relative to the premixed. MWCNTs and CdSe-QDs have been used as intercalating agents to reduce restacking of graphene nanosheets during nanocomposite preparation. Voltammetry, chronoamperometry, scanning electrochemical microscopy and electrochemical impedance spectroscopy methods are used for electrochemical characterization modified GCE. X-ray photoelectron spectroscopy, X-ray diffractometry, transmission electron microscopy, scanning electron microscopy, infra-red spectroscopy, Raman spectroscopy were used to explore surface functionalities, morphology and topography of the nanocomposites. Electrocatalytic activity and possible applications of the modified electrodes were tested using oxygen reduction reaction, l-cysteine oxidation and paraquat reduction. Activity of nanocomposites was found superior over individual nanomaterials in these applications.
- Full Text:
Nascent Desires: Gendered Sexualities in Life Orientation Sexuality Education Programmes and Popular Music
- Authors: Moodley, Dale Dhersen
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3274 , http://hdl.handle.net/10962/d1021260
- Description: Formal school-based sexuality education is one medium, amongst others, that recognises young people’s sexuality, but usually as at-risk and/or risk taking subjects, or as innocent subjects. I analyse the gendered sexualities of young people as represented in: Grade 10 Life Orientation sexuality education programmes and popular music, as two mediums of sexual socialisation in Grade 10 learners’ lives, and as engaged with by Grade 10 learners and educators. I collected data from two schools in the Eastern Cape that included: (i) sections on sexuality from two Life Orientation manuals used by educators in classrooms: ‘Oxford Successful Life Orientation’ (2011), and ‘Shuters Top Class Life Orientation’ (2011); (ii) videos and lyrics of three songs voted most popular by learners which were ‘Climax’ by Usher, ‘Beez in the Trap’ by Nicki Minaj, and ‘Where Have You Been’ by Rihanna; (iii) observations of seven sexuality education classes; and, (iv) in-depth semistructured interviews conducted with eight learners and two educators. I draw on an integrated theoretical and methodological approach – Foucauldian, feminist poststructural and psychosocial psychoanalytic perspectives – to conceptualise and analyse gendered sexualities in terms of: (i) the dominant gendered discourses found in sexuality education manuals, and music videos and lyrics; (ii) the reflexive and interactive gendered subject positions taken up and/or resisted by learners and educators during classroom lessons and one-on-one interviews; and, (iii) learners’ and educators’ conscious and unconscious investments in particular gendered subject positions during one-on-one interviews. These three sets of analysis produced four major themes. The first theme centres on responsible sexuality; young women are expected to assume more sexual responsility than young men, thus curbing their sexual agency. The second theme outlines three types of pleasure – sexual, romantic and dating and/or relationship pleasure – that accord young men and women active and passive ways of exercising pleasure. The third theme highlights the heteronormative transitioning adolescent subject that constructs young women as reproductive subjects and young men as sexual subjects. The last theme focuses on gendered power relations and raunch culture, and maintains that young men are powerful and likely to commit acts of sexual violence against young women because they are powerless. The central argument developed when viewing all the themes is that dominant gendered discourse, gendered subject positions, and conscious and unconscious investments in these positions challenge the extent to which the gendered meanings that underpin adolescent learners’ sexuality are stable and fixed. The gendered discourses in the Life Orientation sexuality education programmes showed that gender is expressed rigidly, thus privileging masculine over feminine sexuality. However, the gendered discourses in the popular music contested rigid gender binaries and produced fluid and equitable masculine and feminine sexualities. The classroom practices depicted multiple and more equatable gendered sexualities, highlighting just how contested gender is. Finally, educator and learners’ personal biographies illustrated how conflicting masculine and feminine sexualities present a signficant source of emotional conflict for them. It may benefit policymakers and stakeholders to consider informal mediums of sexual socialisation for learners, such as music, when drafting the Life Orientation sexuality education curriculum, whilst also taking into account learners and educators personal lives.
- Full Text:
- Authors: Moodley, Dale Dhersen
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3274 , http://hdl.handle.net/10962/d1021260
- Description: Formal school-based sexuality education is one medium, amongst others, that recognises young people’s sexuality, but usually as at-risk and/or risk taking subjects, or as innocent subjects. I analyse the gendered sexualities of young people as represented in: Grade 10 Life Orientation sexuality education programmes and popular music, as two mediums of sexual socialisation in Grade 10 learners’ lives, and as engaged with by Grade 10 learners and educators. I collected data from two schools in the Eastern Cape that included: (i) sections on sexuality from two Life Orientation manuals used by educators in classrooms: ‘Oxford Successful Life Orientation’ (2011), and ‘Shuters Top Class Life Orientation’ (2011); (ii) videos and lyrics of three songs voted most popular by learners which were ‘Climax’ by Usher, ‘Beez in the Trap’ by Nicki Minaj, and ‘Where Have You Been’ by Rihanna; (iii) observations of seven sexuality education classes; and, (iv) in-depth semistructured interviews conducted with eight learners and two educators. I draw on an integrated theoretical and methodological approach – Foucauldian, feminist poststructural and psychosocial psychoanalytic perspectives – to conceptualise and analyse gendered sexualities in terms of: (i) the dominant gendered discourses found in sexuality education manuals, and music videos and lyrics; (ii) the reflexive and interactive gendered subject positions taken up and/or resisted by learners and educators during classroom lessons and one-on-one interviews; and, (iii) learners’ and educators’ conscious and unconscious investments in particular gendered subject positions during one-on-one interviews. These three sets of analysis produced four major themes. The first theme centres on responsible sexuality; young women are expected to assume more sexual responsility than young men, thus curbing their sexual agency. The second theme outlines three types of pleasure – sexual, romantic and dating and/or relationship pleasure – that accord young men and women active and passive ways of exercising pleasure. The third theme highlights the heteronormative transitioning adolescent subject that constructs young women as reproductive subjects and young men as sexual subjects. The last theme focuses on gendered power relations and raunch culture, and maintains that young men are powerful and likely to commit acts of sexual violence against young women because they are powerless. The central argument developed when viewing all the themes is that dominant gendered discourse, gendered subject positions, and conscious and unconscious investments in these positions challenge the extent to which the gendered meanings that underpin adolescent learners’ sexuality are stable and fixed. The gendered discourses in the Life Orientation sexuality education programmes showed that gender is expressed rigidly, thus privileging masculine over feminine sexuality. However, the gendered discourses in the popular music contested rigid gender binaries and produced fluid and equitable masculine and feminine sexualities. The classroom practices depicted multiple and more equatable gendered sexualities, highlighting just how contested gender is. Finally, educator and learners’ personal biographies illustrated how conflicting masculine and feminine sexualities present a signficant source of emotional conflict for them. It may benefit policymakers and stakeholders to consider informal mediums of sexual socialisation for learners, such as music, when drafting the Life Orientation sexuality education curriculum, whilst also taking into account learners and educators personal lives.
- Full Text:
Ndiyoyika
- Authors: Nyezwa, Mxolisi
- Date: 2016
- Language: English , Xhosa
- Type: Thesis , Masters , MA
- Identifier: vital:6021 , http://hdl.handle.net/10962/d1021245
- Description: This thesis collection is a book of isiXhosa poems in three sections: - Poems derived and influenced by the rhythmic structure and the lyrics of Maskandi music - More introspective and personal poems derived from other influences: International poetry, South African poetry, and certain jazz and soul music - A major poem titled, “Nozala, umqolo wakho uphandle” which delves into the state of South Africa and explores the relationships that entrench poverty and powerlessness in post-apartheid South Africa. , Le thisisi yingqokelela yemibongo yesiXhosa eyohlulwe yazizigaba ezintathu: - Imibongo ephenjelelwe ziingoma nezingqi zomculo kaMaskandi - Imibongo ephenjelelwe zizimvo neemvakalelo zam njengombhali, ngakumbi iintshukumo zomzimba nezomphefumlo ezithundezwe ziimbongi zamazwe omhlaba, ezoMzantsi Afrika, kunye nemiculo efana ne-jazz, ne-soul - Umbongo ombaxa osihloko sithi, “Nozala, umqolo wakho uphandle” othetha ngelizwe lethu iMzantsi Afrika, uqwalasela indlela ekuphethwe ngayo ilizwe ziziphathamandla, nendlela abasemagunyeni abaphembelela ngayo intswela-ngqesho nentlupheko eluntwini, kwanokufiphala kobutsha-ntliziyo nobuthanda-zwe kubemi beli lizwe.
- Full Text:
- Authors: Nyezwa, Mxolisi
- Date: 2016
- Language: English , Xhosa
- Type: Thesis , Masters , MA
- Identifier: vital:6021 , http://hdl.handle.net/10962/d1021245
- Description: This thesis collection is a book of isiXhosa poems in three sections: - Poems derived and influenced by the rhythmic structure and the lyrics of Maskandi music - More introspective and personal poems derived from other influences: International poetry, South African poetry, and certain jazz and soul music - A major poem titled, “Nozala, umqolo wakho uphandle” which delves into the state of South Africa and explores the relationships that entrench poverty and powerlessness in post-apartheid South Africa. , Le thisisi yingqokelela yemibongo yesiXhosa eyohlulwe yazizigaba ezintathu: - Imibongo ephenjelelwe ziingoma nezingqi zomculo kaMaskandi - Imibongo ephenjelelwe zizimvo neemvakalelo zam njengombhali, ngakumbi iintshukumo zomzimba nezomphefumlo ezithundezwe ziimbongi zamazwe omhlaba, ezoMzantsi Afrika, kunye nemiculo efana ne-jazz, ne-soul - Umbongo ombaxa osihloko sithi, “Nozala, umqolo wakho uphandle” othetha ngelizwe lethu iMzantsi Afrika, uqwalasela indlela ekuphethwe ngayo ilizwe ziziphathamandla, nendlela abasemagunyeni abaphembelela ngayo intswela-ngqesho nentlupheko eluntwini, kwanokufiphala kobutsha-ntliziyo nobuthanda-zwe kubemi beli lizwe.
- Full Text:
Notebook of unremembered poems
- Authors: McKeown, Jean Wallace
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:6013 , http://hdl.handle.net/10962/d1021233
- Description: My poems contain narrative elements and explore themes of identity, motherhood, sexuality, and fear of relinquishing control. Sharon Olds, in her book Stag’s Leap, sums up my intention: “and I saw again how blessed my life has been, / first, to have been able to love, / then, to have the parting now behind me.” My collection chronicles a path towards acceptance of self from childhood onwards, and, more than that, a pleasure and pride in self, and I have tried to find the forms which will reflect this path in the reader’s own experience. Most of the poems are written in a conversational voice and a free-form style which gives me creative licence to explore transition and transformation.
- Full Text:
- Authors: McKeown, Jean Wallace
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:6013 , http://hdl.handle.net/10962/d1021233
- Description: My poems contain narrative elements and explore themes of identity, motherhood, sexuality, and fear of relinquishing control. Sharon Olds, in her book Stag’s Leap, sums up my intention: “and I saw again how blessed my life has been, / first, to have been able to love, / then, to have the parting now behind me.” My collection chronicles a path towards acceptance of self from childhood onwards, and, more than that, a pleasure and pride in self, and I have tried to find the forms which will reflect this path in the reader’s own experience. Most of the poems are written in a conversational voice and a free-form style which gives me creative licence to explore transition and transformation.
- Full Text:
Observational cosmology with imperfect data
- Authors: Bester, Hertzog Landman
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/463 , vital:19961
- Description: We develop a formalism suitable to infer the background geometry of a general spherically symmetric dust universe directly from data on the past lightcone. This direct observational approach makes minimal assumptions about inaccessible parts of the Universe. The non-parametric and Bayesian framework we propose provides a very direct way to test one of the most fundamental underlying assumptions of concordance cosmology viz. the Copernican principle. We present the Copernicus algorithm for this purpose. By applying the algorithm to currently available data, we demonstrate that it is not yet possible to confirm or refute the validity of the Copernican principle within the proposed framework. This is followed by an investigation which aims to determine which future data will best be able to test the Copernican principle. Our results on simulated data suggest that, besides the need to improve the current data, it will be important to identify additional model independent observables for this purpose. The main difficulty with current data is their inability to constrain the value of the cosmological constant. We show how redshift drift data could be used to infer its value with minimal assumptions about the nature of the early Universe. We also discuss some alternative applications of the algorithm.
- Full Text:
- Authors: Bester, Hertzog Landman
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/463 , vital:19961
- Description: We develop a formalism suitable to infer the background geometry of a general spherically symmetric dust universe directly from data on the past lightcone. This direct observational approach makes minimal assumptions about inaccessible parts of the Universe. The non-parametric and Bayesian framework we propose provides a very direct way to test one of the most fundamental underlying assumptions of concordance cosmology viz. the Copernican principle. We present the Copernicus algorithm for this purpose. By applying the algorithm to currently available data, we demonstrate that it is not yet possible to confirm or refute the validity of the Copernican principle within the proposed framework. This is followed by an investigation which aims to determine which future data will best be able to test the Copernican principle. Our results on simulated data suggest that, besides the need to improve the current data, it will be important to identify additional model independent observables for this purpose. The main difficulty with current data is their inability to constrain the value of the cosmological constant. We show how redshift drift data could be used to infer its value with minimal assumptions about the nature of the early Universe. We also discuss some alternative applications of the algorithm.
- Full Text:
Oncoming traffic
- Authors: Manaka, Maakomele R
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:6008 , http://hdl.handle.net/10962/1021220
- Description: The poems in my collection Oncoming Traffic mainly look at the silence in my personal conflicts. Fusing different styles and tones of writing from the lyrical to the surreal, these poems grapple with issues I struggle with on a daily basis. First as a man, second as a man with a physical disability, and lastly as a black man dealing with the reality of living in a dysfunctional/disabled society. The silence in my personal conflicts means, writing what I cannot say, stripping myself bare and vulnerable. My inspiration has come from poets who articulate such silences.
- Full Text:
- Authors: Manaka, Maakomele R
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:6008 , http://hdl.handle.net/10962/1021220
- Description: The poems in my collection Oncoming Traffic mainly look at the silence in my personal conflicts. Fusing different styles and tones of writing from the lyrical to the surreal, these poems grapple with issues I struggle with on a daily basis. First as a man, second as a man with a physical disability, and lastly as a black man dealing with the reality of living in a dysfunctional/disabled society. The silence in my personal conflicts means, writing what I cannot say, stripping myself bare and vulnerable. My inspiration has come from poets who articulate such silences.
- Full Text:
Penguin parenting : assortative mating, nest attendance and sex-specific chick provisioning in the African Penguin (Spheniscus demersus)
- Authors: Smith, Diane Lauren
- Date: 2016
- Subjects: African penguin , Penguins -- South Africa , Penguins -- Sexual behavior , Parental behavior in animals
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5943 , http://hdl.handle.net/10962/d1019993
- Description: Animal behaviour is especially sensitive to environmental variability and prey availability during the breeding season, and this is particularly true for non-volant, central place foragers such as the endangered African Penguin (Spheniscus demersus). Individual sex and morphology, as well as the level of assortment within mated pairs can influence both the behaviour and the reproductive success of species exhibiting biparental care. This study made use of a large biometric database and nest attendance video footage to determine the influence of intrinsic (assortative mating, brood size and chick age) and extrinsic (environmental conditions, anthropic disturbance) factors on breeding behaviour and performance of African Penguins on Bird Island, Algoa Bay, during peak breeding (March - July) in 2013. While sexual dimorphism in African Penguins is subtle, the colony-specific discriminant functions presented here provide an accurate sexing tool when only bill and flipper length are available. Despite the premise that selection of a large, high-quality mate in this longlived, monogamous seabird governs lifetime fitness, only low levels of assortative mating were found, and this only for earlier breeders, when larger females (but not males) bred. The 2013 season was a particularly successful one, coinciding with above-average sardine and anchovy abundance, and almost 80 percent of monitored nests were double-brooded, with very low levels of mortality. A- and B-chicks of double broods and singleton chicks grew at similar rates and exhibited similar body condition indices. In these conditions, chick developmental rates were independent of parental size, assortment or provisioning behaviour. Females raising a double brood were significantly lighter and in poorer body condition than those raising a single chick, although the same trend was not evident in males. Offspring sex ratio in 2013 (2.27:1) favoured male chicks, suggesting that there is potential to over-produce the larger sex when resources are plentiful. Peak nest arrival and departure times of parents did not change over the course of monitored breeding attempts (March-June), nor were they different for disturbed and undisturbed nests or for a single or double brood. The increase in CCTV-observed provisioning rate as chicks grew larger was best explained by brood size, at-sea chlorophyll a concentration, and maximum air temperature, but was unrelated to parental morphology or assortative index. Importantly, parental absenteeism commenced earlier and was markedly greater in nests frequently handled by researchers than in undisturbed nests. Both the time spent together by parents, and absenteeism were measurably affected by maximum afternoon air temperatures, the effects of which are expected to be exacerbated by poorer foraging conditions and climate change. A third of manually-monitored nests shared chick-guarding duties unequally, although this phenomenon was independent of parental sex or morphology. The adaptive benefits of mating patterns and division of labour during chick-rearing may only become apparent in a year of below-average food availability and it is highly recommended that this study be repeated in a year of scarce food resources. These findings augment past foraging ecology studies and demonstrate that investigator disturbance and environmental conditions can affect the nesting behaviour of this highly threatened seabird.
- Full Text:
- Authors: Smith, Diane Lauren
- Date: 2016
- Subjects: African penguin , Penguins -- South Africa , Penguins -- Sexual behavior , Parental behavior in animals
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5943 , http://hdl.handle.net/10962/d1019993
- Description: Animal behaviour is especially sensitive to environmental variability and prey availability during the breeding season, and this is particularly true for non-volant, central place foragers such as the endangered African Penguin (Spheniscus demersus). Individual sex and morphology, as well as the level of assortment within mated pairs can influence both the behaviour and the reproductive success of species exhibiting biparental care. This study made use of a large biometric database and nest attendance video footage to determine the influence of intrinsic (assortative mating, brood size and chick age) and extrinsic (environmental conditions, anthropic disturbance) factors on breeding behaviour and performance of African Penguins on Bird Island, Algoa Bay, during peak breeding (March - July) in 2013. While sexual dimorphism in African Penguins is subtle, the colony-specific discriminant functions presented here provide an accurate sexing tool when only bill and flipper length are available. Despite the premise that selection of a large, high-quality mate in this longlived, monogamous seabird governs lifetime fitness, only low levels of assortative mating were found, and this only for earlier breeders, when larger females (but not males) bred. The 2013 season was a particularly successful one, coinciding with above-average sardine and anchovy abundance, and almost 80 percent of monitored nests were double-brooded, with very low levels of mortality. A- and B-chicks of double broods and singleton chicks grew at similar rates and exhibited similar body condition indices. In these conditions, chick developmental rates were independent of parental size, assortment or provisioning behaviour. Females raising a double brood were significantly lighter and in poorer body condition than those raising a single chick, although the same trend was not evident in males. Offspring sex ratio in 2013 (2.27:1) favoured male chicks, suggesting that there is potential to over-produce the larger sex when resources are plentiful. Peak nest arrival and departure times of parents did not change over the course of monitored breeding attempts (March-June), nor were they different for disturbed and undisturbed nests or for a single or double brood. The increase in CCTV-observed provisioning rate as chicks grew larger was best explained by brood size, at-sea chlorophyll a concentration, and maximum air temperature, but was unrelated to parental morphology or assortative index. Importantly, parental absenteeism commenced earlier and was markedly greater in nests frequently handled by researchers than in undisturbed nests. Both the time spent together by parents, and absenteeism were measurably affected by maximum afternoon air temperatures, the effects of which are expected to be exacerbated by poorer foraging conditions and climate change. A third of manually-monitored nests shared chick-guarding duties unequally, although this phenomenon was independent of parental sex or morphology. The adaptive benefits of mating patterns and division of labour during chick-rearing may only become apparent in a year of below-average food availability and it is highly recommended that this study be repeated in a year of scarce food resources. These findings augment past foraging ecology studies and demonstrate that investigator disturbance and environmental conditions can affect the nesting behaviour of this highly threatened seabird.
- Full Text:
Perceptions and experiences of G2E e-Government workplace restructuring: The cases of Buffalo City and City of Cape Town metropolitan municipalities, South Africa
- Authors: Makwembere, Sandra
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/617 , vital:19975
- Description: Taking the cases of Buffalo City Metropolitan municipality (BCMM) and City of Cape Town Metropolitan municipality (CoCT), this thesis explores the implications of government to employee (G2E) electronic government workplace restructuring on skills transformation and workplace control as perceived by back office employees and managers from different Corporate Services departments. It aims to describe the arrangements, rationale and degree of G2E e-government at BCMM and CoCT, investigate how managers, employees and union representatives identify the workplace changes relating to skill as well as document and analyse workplace struggles linked to G2E e-government. Using labour process analysis, the impacts of G2E e-government technological change are conceptualised. The labour process concepts alert us to ways in which G2E e-government technology is applied in the context of specific public sector production relations. They explain how employees and managers experience the dynamics of skill transformation and the mechanisms of control related to G2E e-government. The consideration of the labour process contrasts predominant e-government scholarly works that focus on government websites. Further, by using case study methods, namely interviews, surveys and observations, the thesis documents the particular back office employees’ and managers’ realities of G2E e-government which are marginalised in scholarly literature. The sample of respondents were selected using purposive sampling based on the subjects’ knowledge and experience, snowball sampling following referrals and random sampling during site visits. The respondents included four managers, four employees, two shop stewards and one service provider at BCMM and 16 managers, 20 employees and four shop stewards at CoCT. The findings from BCMM and CoCT illustrate how G2E e-government workplace restructuring individualises the labour process through the kind of technologies it introduces. Moreover, they show how the restructuring facilitates electronic information, communication and operations which broaden demands on technical as well as social skills. The findings also show that the restructuring extends avenues for managerial control thereby marginalising union representivity as the workplace control systems create opportunities for systemic control by management. As the South African government adopts electronic government and makes optimistic declarations of “cost saving”, “efficiency”, “productivity” and “innovation” through egovernment, the study uncovers marginalised local government employee and manager experiences. It contributes to building new knowledge on the impacts of contemporary technological change on the local government labour process and contributes to debates around the effects of G2E e-government reforms on local government.
- Full Text:
- Authors: Makwembere, Sandra
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/617 , vital:19975
- Description: Taking the cases of Buffalo City Metropolitan municipality (BCMM) and City of Cape Town Metropolitan municipality (CoCT), this thesis explores the implications of government to employee (G2E) electronic government workplace restructuring on skills transformation and workplace control as perceived by back office employees and managers from different Corporate Services departments. It aims to describe the arrangements, rationale and degree of G2E e-government at BCMM and CoCT, investigate how managers, employees and union representatives identify the workplace changes relating to skill as well as document and analyse workplace struggles linked to G2E e-government. Using labour process analysis, the impacts of G2E e-government technological change are conceptualised. The labour process concepts alert us to ways in which G2E e-government technology is applied in the context of specific public sector production relations. They explain how employees and managers experience the dynamics of skill transformation and the mechanisms of control related to G2E e-government. The consideration of the labour process contrasts predominant e-government scholarly works that focus on government websites. Further, by using case study methods, namely interviews, surveys and observations, the thesis documents the particular back office employees’ and managers’ realities of G2E e-government which are marginalised in scholarly literature. The sample of respondents were selected using purposive sampling based on the subjects’ knowledge and experience, snowball sampling following referrals and random sampling during site visits. The respondents included four managers, four employees, two shop stewards and one service provider at BCMM and 16 managers, 20 employees and four shop stewards at CoCT. The findings from BCMM and CoCT illustrate how G2E e-government workplace restructuring individualises the labour process through the kind of technologies it introduces. Moreover, they show how the restructuring facilitates electronic information, communication and operations which broaden demands on technical as well as social skills. The findings also show that the restructuring extends avenues for managerial control thereby marginalising union representivity as the workplace control systems create opportunities for systemic control by management. As the South African government adopts electronic government and makes optimistic declarations of “cost saving”, “efficiency”, “productivity” and “innovation” through egovernment, the study uncovers marginalised local government employee and manager experiences. It contributes to building new knowledge on the impacts of contemporary technological change on the local government labour process and contributes to debates around the effects of G2E e-government reforms on local government.
- Full Text:
Petrogenetic implications for the Merensky Reef: a platinum-group element distribution study from wide-reef facies in the western Bushveld Complex, RSA
- Authors: Largatzis, Savvas Anthony
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3167 , vital:20380
- Description: Despite decades of research and its economic importance, the formation of the Merensky Reef still remains controversial. This study reports on the distribution of platinum-group elements within widereef facies in an attempt to identify petrogenetic controls in the formation of the Merensky Reef. Widereef Merensky was sampled from Eland Platinum Mines in the western Bushveld. Macroscopic investigation of the drillcore identified a basal chromitite stringer overlying an anorthositic footwall. The reef comprised a pyroxenite unit while the hangingwall comprised noritic, leuconoritic and anorthositic units (upwards the stratigraphy). Furthermore, an anorthositic seam was identified within the pyroxenite reef, near the top of the unit. Ophitic textures of orthopyroxene oikocrysts comprising inclusions of plagioclase chadacrysts suggest that the crystallization of plagioclase preceded the crystallization of orthopyroxene. Furthermore, plagioclase and orthopyroxene were shown to be in mineral disequilibrium with one another. Pervasive hydrous alteration features throughout the Merensky Reef suggest late stage deuteric alteration. Mineral chemistry of plagioclase cores recorded ranges for An content in the Merensky Reef as follows: An72-79 in the anorthositic footwall, An71-77 in the chromitite stringer, An45-78 in the pyroxenite reef unit, An47-73 in the anorthosite reef unit, An72-76 in the norite hangingwall, An75-77 in the leuconorite hangingwall and An72-77 in the anorthosite hangingwall. This suggest that the reef units were more evolved than the footwall and hangingwall units. Furthermore, plagioclase showed reverse zoning in the anorthosite footwall unit while normal zoning was identified in the anorthosite reef unit. This suggested that the footwall unit underwent reheating and re-equilibration with a hotter, more primitive magma (also evident in recrystallization textures) while the anorthositic reef unit cooled relatively slowly and interstitial plagioclase present within this unit equilibrated with a trapped, more evolved liquid. The pyroxenite reef unit shows enrichment in incompatible elements and corresponding negative Eu anomalies, indicating the presence of trapped liquids. Cu, Ni and S concentrations remained low throughout the reef with the exception of a peak underlying the anorthositic seam and further enrichment underlying this peak. Platinum-group element geochemistry identified two major peaks: an upper peak which coincided with the peaks for Cu, Ni and S, and showed preferential enrichment in Pd and Au relative to other PGE, and a lower peak which coincided with the presence of chromitite and showed the preferential enrichment of Os, Ir, Ru, Rh and Pt relative to Pd, Au, Cu and Ni. The formation of the lower peak was consistent with a model involving the co-precipitation of chromite and PGE clusters (as PGM) while the upper peak was attributed to a model involving the collection of PGE by an immiscible sulphide liquid. Moreover, high Cu/Pd and Pt/Pd ratios in the lower pyroxenite unit indicated a process involving sulphide fractional segregation and scavenging while the inverse, present within the upper pyroxenite unit, suggested a more dynamic system involving the introduction of PGE-undepleted magma and S during simultaneous sulphide precipitation. Furthermore, a separation of PPGE peaks from IPGE peaks was observed within the pyroxenite unit, indicating a different partitioning behavior between PPGE and IPGE. The separation of these peaks is attributed to a sulphide liquid fractionation model while depletion haloes occurring in the proximity of the main PGE peaks was suggested to form through an Ostwald-ripening type mechanism. The results of this study are consistent with a model for the formation of the Merensky Reef involving a combination of geochemical processes, including sulphide segregation and fractionation, as well as multiple replenishments of magma.
- Full Text:
- Authors: Largatzis, Savvas Anthony
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3167 , vital:20380
- Description: Despite decades of research and its economic importance, the formation of the Merensky Reef still remains controversial. This study reports on the distribution of platinum-group elements within widereef facies in an attempt to identify petrogenetic controls in the formation of the Merensky Reef. Widereef Merensky was sampled from Eland Platinum Mines in the western Bushveld. Macroscopic investigation of the drillcore identified a basal chromitite stringer overlying an anorthositic footwall. The reef comprised a pyroxenite unit while the hangingwall comprised noritic, leuconoritic and anorthositic units (upwards the stratigraphy). Furthermore, an anorthositic seam was identified within the pyroxenite reef, near the top of the unit. Ophitic textures of orthopyroxene oikocrysts comprising inclusions of plagioclase chadacrysts suggest that the crystallization of plagioclase preceded the crystallization of orthopyroxene. Furthermore, plagioclase and orthopyroxene were shown to be in mineral disequilibrium with one another. Pervasive hydrous alteration features throughout the Merensky Reef suggest late stage deuteric alteration. Mineral chemistry of plagioclase cores recorded ranges for An content in the Merensky Reef as follows: An72-79 in the anorthositic footwall, An71-77 in the chromitite stringer, An45-78 in the pyroxenite reef unit, An47-73 in the anorthosite reef unit, An72-76 in the norite hangingwall, An75-77 in the leuconorite hangingwall and An72-77 in the anorthosite hangingwall. This suggest that the reef units were more evolved than the footwall and hangingwall units. Furthermore, plagioclase showed reverse zoning in the anorthosite footwall unit while normal zoning was identified in the anorthosite reef unit. This suggested that the footwall unit underwent reheating and re-equilibration with a hotter, more primitive magma (also evident in recrystallization textures) while the anorthositic reef unit cooled relatively slowly and interstitial plagioclase present within this unit equilibrated with a trapped, more evolved liquid. The pyroxenite reef unit shows enrichment in incompatible elements and corresponding negative Eu anomalies, indicating the presence of trapped liquids. Cu, Ni and S concentrations remained low throughout the reef with the exception of a peak underlying the anorthositic seam and further enrichment underlying this peak. Platinum-group element geochemistry identified two major peaks: an upper peak which coincided with the peaks for Cu, Ni and S, and showed preferential enrichment in Pd and Au relative to other PGE, and a lower peak which coincided with the presence of chromitite and showed the preferential enrichment of Os, Ir, Ru, Rh and Pt relative to Pd, Au, Cu and Ni. The formation of the lower peak was consistent with a model involving the co-precipitation of chromite and PGE clusters (as PGM) while the upper peak was attributed to a model involving the collection of PGE by an immiscible sulphide liquid. Moreover, high Cu/Pd and Pt/Pd ratios in the lower pyroxenite unit indicated a process involving sulphide fractional segregation and scavenging while the inverse, present within the upper pyroxenite unit, suggested a more dynamic system involving the introduction of PGE-undepleted magma and S during simultaneous sulphide precipitation. Furthermore, a separation of PPGE peaks from IPGE peaks was observed within the pyroxenite unit, indicating a different partitioning behavior between PPGE and IPGE. The separation of these peaks is attributed to a sulphide liquid fractionation model while depletion haloes occurring in the proximity of the main PGE peaks was suggested to form through an Ostwald-ripening type mechanism. The results of this study are consistent with a model for the formation of the Merensky Reef involving a combination of geochemical processes, including sulphide segregation and fractionation, as well as multiple replenishments of magma.
- Full Text:
Phylogenetics and historical biogeography of the Teloganodidae (Ephemeroptera)
- Pereira da Conceicoa, Lyndall Louise
- Authors: Pereira da Conceicoa, Lyndall Louise
- Date: 2016
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/64900 , vital:28629
- Description: The Teloganodidae are a mayfly family endemic to the southwestern Cape (South Africa), with relatives in Madagascar and Asia. Like many other aquatic invertebrates in Africa, they have been considerably understudied. Research into biodiversity and biogeography allows an understanding of the earth’s biota, producing knowledge which can be used to develop strategies to preserve and monitor this biota. Mismanagement of water systems places biodiversity of river fauna under an ever-increasing extinction threat. This investigation explores rivers in under-collected areas to determine how well teloganodids have been represented in the literature, with four genera and five species described at the onset of this study. A lectotype for Lestagella penicillata Barnard (1940) has been elected and described in detail, setting “benchmark” characters for future descriptions. Standard DNA sequencing methods provide portions of three mitochondrial genes; cytochrome oxidase subunit I (COI), small subunit ribosomal 16S RNA (16S), 12S ribosomal DNA (12S) and two nuclear genes, Histone 3 (H3) and 28S ribosomal DNA (28S) for up to 255 specimens. Fore and hind wings of 79 teloganodid adults were used to examine phylogenetic signal and evolutionary divergence using geometric morphometrics. A multi-faceted approach is used to investigate relationships between clades and the effects of deep-time climatic and landform changes which have influenced the diversity and distribution seen today. Tree (Bayesian Inference and Maximum Likelihood) and network (parsimony) phylogenies, ancestral reconstruction, historical biogeography and wingevolution of the Teloganodidae are investigated. Species tree analyses discovered 27 species and six genera. Distinct lineages are restricted to catchments, and strong phylogeographic structure was found within most genera. Southern African Teloganodidae are shown to have originated in the Cretaceous, with divergence and dispersal of lineages depended on their established locality at the time of tectonic events (uplift) and climatic changes (sea level regressions and transgressions). Geographic clines in wing-shape of Lestagella across its range imply evolutionary adaptations to specific catchment landscape and environment. A detailed analysis of biodiversity has many valuable contributions, from directing future research, understanding adaptive processes, fine-tuning phylogeographical and evolutionary hypotheses, to improving management and conservation decisions in order to preserve endemic biodiversity hotspots.
- Full Text:
- Authors: Pereira da Conceicoa, Lyndall Louise
- Date: 2016
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/64900 , vital:28629
- Description: The Teloganodidae are a mayfly family endemic to the southwestern Cape (South Africa), with relatives in Madagascar and Asia. Like many other aquatic invertebrates in Africa, they have been considerably understudied. Research into biodiversity and biogeography allows an understanding of the earth’s biota, producing knowledge which can be used to develop strategies to preserve and monitor this biota. Mismanagement of water systems places biodiversity of river fauna under an ever-increasing extinction threat. This investigation explores rivers in under-collected areas to determine how well teloganodids have been represented in the literature, with four genera and five species described at the onset of this study. A lectotype for Lestagella penicillata Barnard (1940) has been elected and described in detail, setting “benchmark” characters for future descriptions. Standard DNA sequencing methods provide portions of three mitochondrial genes; cytochrome oxidase subunit I (COI), small subunit ribosomal 16S RNA (16S), 12S ribosomal DNA (12S) and two nuclear genes, Histone 3 (H3) and 28S ribosomal DNA (28S) for up to 255 specimens. Fore and hind wings of 79 teloganodid adults were used to examine phylogenetic signal and evolutionary divergence using geometric morphometrics. A multi-faceted approach is used to investigate relationships between clades and the effects of deep-time climatic and landform changes which have influenced the diversity and distribution seen today. Tree (Bayesian Inference and Maximum Likelihood) and network (parsimony) phylogenies, ancestral reconstruction, historical biogeography and wingevolution of the Teloganodidae are investigated. Species tree analyses discovered 27 species and six genera. Distinct lineages are restricted to catchments, and strong phylogeographic structure was found within most genera. Southern African Teloganodidae are shown to have originated in the Cretaceous, with divergence and dispersal of lineages depended on their established locality at the time of tectonic events (uplift) and climatic changes (sea level regressions and transgressions). Geographic clines in wing-shape of Lestagella across its range imply evolutionary adaptations to specific catchment landscape and environment. A detailed analysis of biodiversity has many valuable contributions, from directing future research, understanding adaptive processes, fine-tuning phylogeographical and evolutionary hypotheses, to improving management and conservation decisions in order to preserve endemic biodiversity hotspots.
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Phylogenetics of the keratin-feeding beetle family Trogidae (Coleoptera: Scarabaeoidea)
- Authors: Strümpher, Werner Petrus
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/1232 , vital:20037
- Description: Trogidae constitute a monophyletic and biologically unique family within the Scarabaeoidea, being the only keratinophagous group in its superfamily. Traditionally, the family has been divided into three distinctive genera, Omorgus Erichson, Polynoncus Burmeister, and Trox Fabricius. Although the taxonomy of the group is relatively well studied, recently changes to the existing classification have been proposed without the family as currently constituted being subjected to phylogenetic analyses. In this study I present the first molecular phylogeny for this cosmopolitan family, based on three partially sequenced gene regions: 16SrRNA, 18S rRNA and 28S rRNA domain 2. Analyses resolved relationships between and within genera and subgenera that are largely congruent with existing taxonomic hypotheses based on morphology. I recovered four well-supported radiations: Polynoncus, Omorgus, Holarctic Trox and Afrotropical Phoberus. One of the more surprising results was the monophyly of Phoberus. Based on the evidence, I propose reinstating the genus Phoberus to accommodate all Afrotropical (including Madagascan endemic) species. The results re-emphasise the validity of Scholtz’s (1986a) classification system for the genus Omorgusand its subgeneraand provide evidence of an African origin for Madagascan trogids. Divergence analysis was able to date the major events for the origin of extant lineages of Trogidae. The subsequent diversification of the major lineages is largely attributed to Pangaean and Gondwanan vicariance events in the Mid-Jurassic and early Late Cretaceous, respectively. The separation of the landmasses resulted in the evolution of four distinct groups: Omorgus, Polynoncus, Trox and Phoberus. The monophyletic subgenus Phoberus MacLeay is of particular interest; about one-third (14 of 40) of the species in the Afrotropical region have lost the ability to fly. To gain insights into the evolution of flightlessness in this clade, phylogenetic relationships among species were inferred using molecular sequence data. Four partial sequences of four genes (COI, 16S, 18S and 28S domain 2) were obtained for 27 species, covering all of the recognised species-groups. Estimated times of divergence were based on published mutation rates for COI. The results recovered eight monophyletic lineages, supporting the morphology-based subdivisions of the genus. Flightlessness evolved at least five times within the subgenus. There is no strong support for the re-acquisition of functional wings once they are lost. Diversification, and the present relictual distributions, in African Phoberus can be linked to climatic and geological events associated with the Miocene and Pliocene Climate Optimum in southern Africa. The evolution of flightlessness in Phoberus is consistent with the habitat stability hypothesis. All flightless species occupy refugial areas with relatively long-term environmental stability. Phoberus is a promising model group for studying evolutionary trends relating to flightlessness, speciation and biogeography. Flightlessness is a counterintuitive evolutionary development, given the many advantages of flight. To interpret the diversification in the flightless Phoberus capensis Scholtz, the phylogenetic relationships among several populations of P. capensis are investigated. Phylogenetic relationships among populations were inferred using molecular sequence data that suggested three distinct evolutionary lineages, which was also supported by morphological characters. Divergence time estimates suggest a Pliocene-Pleistocene diversification. Based on these results, it is suggested that P. capensis experienced climatically-driven allopatric speciation with sheltered Afrotemperate forests and high mountain peaks serving as important refugia in response to climatic exacerbations. The P. capensis complex thus represents a speciation process in which flight-restricted populations evolved in close allopatry, possibly as recently as the Pleistocene. Two of the three divergent and geographically distinct lineages are described as novel species. This study represents the most recent comprehensive work on the Trogidae. On the basis of this study, it is proposed that taxonomic changes to the generic classification of the family be made. Trogidae are formally divided into two subfamilies, Omorginae and Troginae. The subgenus Phoberus is restored to genus rank to include all the Afrotropical species, and Afromorgus is confirmed at subgeneric rank. The genus Madagatrox is synonymised with Phoberus.
- Full Text:
- Authors: Strümpher, Werner Petrus
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/1232 , vital:20037
- Description: Trogidae constitute a monophyletic and biologically unique family within the Scarabaeoidea, being the only keratinophagous group in its superfamily. Traditionally, the family has been divided into three distinctive genera, Omorgus Erichson, Polynoncus Burmeister, and Trox Fabricius. Although the taxonomy of the group is relatively well studied, recently changes to the existing classification have been proposed without the family as currently constituted being subjected to phylogenetic analyses. In this study I present the first molecular phylogeny for this cosmopolitan family, based on three partially sequenced gene regions: 16SrRNA, 18S rRNA and 28S rRNA domain 2. Analyses resolved relationships between and within genera and subgenera that are largely congruent with existing taxonomic hypotheses based on morphology. I recovered four well-supported radiations: Polynoncus, Omorgus, Holarctic Trox and Afrotropical Phoberus. One of the more surprising results was the monophyly of Phoberus. Based on the evidence, I propose reinstating the genus Phoberus to accommodate all Afrotropical (including Madagascan endemic) species. The results re-emphasise the validity of Scholtz’s (1986a) classification system for the genus Omorgusand its subgeneraand provide evidence of an African origin for Madagascan trogids. Divergence analysis was able to date the major events for the origin of extant lineages of Trogidae. The subsequent diversification of the major lineages is largely attributed to Pangaean and Gondwanan vicariance events in the Mid-Jurassic and early Late Cretaceous, respectively. The separation of the landmasses resulted in the evolution of four distinct groups: Omorgus, Polynoncus, Trox and Phoberus. The monophyletic subgenus Phoberus MacLeay is of particular interest; about one-third (14 of 40) of the species in the Afrotropical region have lost the ability to fly. To gain insights into the evolution of flightlessness in this clade, phylogenetic relationships among species were inferred using molecular sequence data. Four partial sequences of four genes (COI, 16S, 18S and 28S domain 2) were obtained for 27 species, covering all of the recognised species-groups. Estimated times of divergence were based on published mutation rates for COI. The results recovered eight monophyletic lineages, supporting the morphology-based subdivisions of the genus. Flightlessness evolved at least five times within the subgenus. There is no strong support for the re-acquisition of functional wings once they are lost. Diversification, and the present relictual distributions, in African Phoberus can be linked to climatic and geological events associated with the Miocene and Pliocene Climate Optimum in southern Africa. The evolution of flightlessness in Phoberus is consistent with the habitat stability hypothesis. All flightless species occupy refugial areas with relatively long-term environmental stability. Phoberus is a promising model group for studying evolutionary trends relating to flightlessness, speciation and biogeography. Flightlessness is a counterintuitive evolutionary development, given the many advantages of flight. To interpret the diversification in the flightless Phoberus capensis Scholtz, the phylogenetic relationships among several populations of P. capensis are investigated. Phylogenetic relationships among populations were inferred using molecular sequence data that suggested three distinct evolutionary lineages, which was also supported by morphological characters. Divergence time estimates suggest a Pliocene-Pleistocene diversification. Based on these results, it is suggested that P. capensis experienced climatically-driven allopatric speciation with sheltered Afrotemperate forests and high mountain peaks serving as important refugia in response to climatic exacerbations. The P. capensis complex thus represents a speciation process in which flight-restricted populations evolved in close allopatry, possibly as recently as the Pleistocene. Two of the three divergent and geographically distinct lineages are described as novel species. This study represents the most recent comprehensive work on the Trogidae. On the basis of this study, it is proposed that taxonomic changes to the generic classification of the family be made. Trogidae are formally divided into two subfamilies, Omorginae and Troginae. The subgenus Phoberus is restored to genus rank to include all the Afrotropical species, and Afromorgus is confirmed at subgeneric rank. The genus Madagatrox is synonymised with Phoberus.
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Pitched
- Authors: Du Plessis, Jana
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:6002 , http://hdl.handle.net/10962/d1021209
- Description: Pitched is a novella made up of short stories. It is about breaking in, breaking down and breaking out of the advertising industry. My protagonist loves and hates this confusing world she lives in. She is tough but also emotional and anxious, often trapped between her strong desires and her strong morality. She finds herself both attracted to and repulsed by the people who inhabit this world - sexy wolf-like men, and prickly female execs alike. I have been inspired by the work of Lidia Yuknavitch, Kate Zambreno, Michelle Tea and Chris Kraus to create a universal woman I can identify with.
- Full Text:
- Authors: Du Plessis, Jana
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:6002 , http://hdl.handle.net/10962/d1021209
- Description: Pitched is a novella made up of short stories. It is about breaking in, breaking down and breaking out of the advertising industry. My protagonist loves and hates this confusing world she lives in. She is tough but also emotional and anxious, often trapped between her strong desires and her strong morality. She finds herself both attracted to and repulsed by the people who inhabit this world - sexy wolf-like men, and prickly female execs alike. I have been inspired by the work of Lidia Yuknavitch, Kate Zambreno, Michelle Tea and Chris Kraus to create a universal woman I can identify with.
- Full Text:
Population assessment and feeding ecology of brown hyenas (hyaena brunnea) in Mountain Zebra National Park, Eastern Cape, South Africa
- Authors: Comley, Jessica
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/2862 , vital:20336
- Description: The development of many small (<400 km2), enclosed game reserves in the Eastern Cape Province of South Africa over the past 25 years has contributed greatly to the conservation of large carnivores. However, the brown hyena (Hyaena brunnea) is one of the least studied large carnivores in South Africa. Nevertheless, the reintroduction of this species (n=3 in 2008) into Mountain Zebra National Park (MZNP) provided the perfect opportunity to broaden our understanding of the role that this carnivore plays in an enclosed system. Camera trap data was collected for just over a year from April 2014 to April 2015 and brown hyena density estimates were calculated using spatially explicit capture-recapture analysis. Left-side images of brown hyenas were used in the analysis and 12 individuals were positively identified. The best model to estimate brown hyena density included a road covariate and estimated brown hyena density to be 6-10 individuals/100 km2 (an absolute abundance of between 12 and 21 individuals), which is higher than densities calculated for brown hyenas in other arid, open systems. In, addition, brown hyena scat samples were collected over a five year period from April 2011 to June 2015 and standard techniques for scat analysis were used to identify prey items. Cheetah (Acinonyx jubatus) and lion (Panthera leo) kill site data were used to investigate the impacts of these species on the diet of brown hyenas. Before the release of lions brown hyenas predominantly scavenged on medium-sized mammals, which was what the cheetahs mainly killed. However, after the release of the lions, brown hyenas predominantly scavenged on large mammals, which was what the lions primarily killed. The results from my study indicate that brown hyenas are most likely reaching high densities in enclosed systems, due to increased scavenging opportunities provided by other large predators. The rapid increase of brown hyena densities from small founder populations in enclosed reserves could result in inbreeding. Therefore, in order to successfully conserve brown hyenas and other large carnivores in South Africa, continual post-release monitoring and possible implementation of meta-population management schemes is required.
- Full Text:
- Authors: Comley, Jessica
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/2862 , vital:20336
- Description: The development of many small (<400 km2), enclosed game reserves in the Eastern Cape Province of South Africa over the past 25 years has contributed greatly to the conservation of large carnivores. However, the brown hyena (Hyaena brunnea) is one of the least studied large carnivores in South Africa. Nevertheless, the reintroduction of this species (n=3 in 2008) into Mountain Zebra National Park (MZNP) provided the perfect opportunity to broaden our understanding of the role that this carnivore plays in an enclosed system. Camera trap data was collected for just over a year from April 2014 to April 2015 and brown hyena density estimates were calculated using spatially explicit capture-recapture analysis. Left-side images of brown hyenas were used in the analysis and 12 individuals were positively identified. The best model to estimate brown hyena density included a road covariate and estimated brown hyena density to be 6-10 individuals/100 km2 (an absolute abundance of between 12 and 21 individuals), which is higher than densities calculated for brown hyenas in other arid, open systems. In, addition, brown hyena scat samples were collected over a five year period from April 2011 to June 2015 and standard techniques for scat analysis were used to identify prey items. Cheetah (Acinonyx jubatus) and lion (Panthera leo) kill site data were used to investigate the impacts of these species on the diet of brown hyenas. Before the release of lions brown hyenas predominantly scavenged on medium-sized mammals, which was what the cheetahs mainly killed. However, after the release of the lions, brown hyenas predominantly scavenged on large mammals, which was what the lions primarily killed. The results from my study indicate that brown hyenas are most likely reaching high densities in enclosed systems, due to increased scavenging opportunities provided by other large predators. The rapid increase of brown hyena densities from small founder populations in enclosed reserves could result in inbreeding. Therefore, in order to successfully conserve brown hyenas and other large carnivores in South Africa, continual post-release monitoring and possible implementation of meta-population management schemes is required.
- Full Text:
Potential benefits and experienced challenges of small household biogas-digesters for rural households
- Authors: Langley, Kyle Anthony
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4789 , http://hdl.handle.net/10962/d1021268
- Description: Access to renewable energy supplies is a critical foundation for sustainable development and poverty alleviation. Anaerobic biogas-digesters also referred to as bio-digesters, have been identified as one of the leading technologies with regards to assisting in improving energy access for remote rural areas that still remain dependent upon biomass usage. This thesis assesses the potential feasibility of bio-digesters for rural households in South Africa by focusing on the experiences of a remote and rural community in Eastern Cape. A standardised survey was used to capture household details and energy use patterns of households with 180 interviews being conducted. Field observations were also conducted on the five bio-digesters installed in the community over a three month period. Despite the predominance of electrification in the community, households were heavily reliant upon biomass in the form of fuelwood and cattle dung to supplement their energy needs. Households supplemented their energy usage with alternative energy sources such as LPG gas and paraffin, especially during periods when electricity was unavailable or deemed too expensive. Initial knowledge of bio-digester technology in the community was non-existent, however with the installation of bio-digesters within the targeted villages, social learning was observed. Despite low temperatures bio-digesters continued to function throughout the study period, though malfunctions did occur and gas production did not reach optimal levels. Primary challenges encountered were the lack of financial subsidies for wide-spread adoption; the limited technical capacity of the community to conduct repairs and minimal gas production due to a build-up of ligneous materials within the gas chamber of the bio-digesters. Bio-digesters were found to provide significant benefits for households and further studies into maximising their effectiveness for rural South African households are recommended.
- Full Text:
- Authors: Langley, Kyle Anthony
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4789 , http://hdl.handle.net/10962/d1021268
- Description: Access to renewable energy supplies is a critical foundation for sustainable development and poverty alleviation. Anaerobic biogas-digesters also referred to as bio-digesters, have been identified as one of the leading technologies with regards to assisting in improving energy access for remote rural areas that still remain dependent upon biomass usage. This thesis assesses the potential feasibility of bio-digesters for rural households in South Africa by focusing on the experiences of a remote and rural community in Eastern Cape. A standardised survey was used to capture household details and energy use patterns of households with 180 interviews being conducted. Field observations were also conducted on the five bio-digesters installed in the community over a three month period. Despite the predominance of electrification in the community, households were heavily reliant upon biomass in the form of fuelwood and cattle dung to supplement their energy needs. Households supplemented their energy usage with alternative energy sources such as LPG gas and paraffin, especially during periods when electricity was unavailable or deemed too expensive. Initial knowledge of bio-digester technology in the community was non-existent, however with the installation of bio-digesters within the targeted villages, social learning was observed. Despite low temperatures bio-digesters continued to function throughout the study period, though malfunctions did occur and gas production did not reach optimal levels. Primary challenges encountered were the lack of financial subsidies for wide-spread adoption; the limited technical capacity of the community to conduct repairs and minimal gas production due to a build-up of ligneous materials within the gas chamber of the bio-digesters. Bio-digesters were found to provide significant benefits for households and further studies into maximising their effectiveness for rural South African households are recommended.
- Full Text:
Predators of aerial insects and riparian cross-boundary trophic dynamics: web-building spiders, dragonflies and damselflies
- Authors: Chari, Lenin Dzibakwe
- Date: 2016
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/55791 , vital:26734
- Description: This thesis characterises the cross-boundary trophic interactions of a relatively small model ecosystem, the Kowie River (Eastern Cape of South Africa), to explore their epistemic implications for systems ecology. Using web-building spiders and odonates (dragonflies and damselflies) as model organisms, I sought to investigate whether the diets of predators of aerial insects could be used to assess the strength of the trophic connectivity between freshwater and terrestrial systems in relation to variables such as stream width, distance from the river and aquatic insect emergence rates and abundances. Predator diet composition was determined by using a combination of diet analysis tools: direct observations of cross-subsidies, naturally-abundant stable (carbon and nitrogen) isotope analysis and fatty acid analysis. I also sought to reveal feeding niches and guilds among riparian aerial predators and investigate how the environment influenced predators’ access to aquatic prey subsidies. As emergent aquatic insect abundances decreased with an increase in distance from the river, and increased with stream width and seasonal changes from winter to summer, stable isotope and fatty acid analyses revealed distinct changes in web-building spider diet composition. Examination of the fatty acid eicosapentaenoic acid, a component commonly used as an indicator of consumer reliance on aquatic nutritional subsidies, showed that aquatic subsidies extended further inland at the wider sections of the river. Spiders and odonates at the wider sections of the Kowie River generally received more subsidies (56 – 70%) than those at the narrower sections (25 – 60%). When terrestrial insect biomass was distinctly low in winter, the benefit of aquatic subsidisation to spiders was relatively lower at the narrower sections of the Kowie River relative to the wide sections. As such, riparian areas adjacent to wide parts of the river were more likely to support larger populations of aerial predators than those at the narrow sections. Apart from the diet changes across time and space, there was evidence of inter-specific niche partitioning in both spiders and odonates, but no differences were observed between males and females of the same species. Results showed odonates of different sizes and hunting strategies had separate dietary niches, hence varied access to aquatic nutritional subsidies. The larger odonate taxa that frequently foraged mid-air had more varied diets and relied less on aquatic emergent insects than the smaller odonates that foraged from perches near the river. There was also evidence of niche partitioning amongst the spiders, as those that built horizontal webs captured more aquatic insects (40 – 78%) than the vertical orb-web builders (20 – 66%). This study showed that the nature and extent of trophic cross-boundary linkages in riparian areas largely depended on the availability of subsidies that varied seasonally and spatially. The width of the stream and seasonal variability emerged as important predictors of emergent insect abundances/biomasses that influenced predator feeding niches. The high mobility of odonates made their reliance on aquatic nutritional subsidies different from the less mobile spiders. The link between the width of the river and the extent of trophic connectivity has implications for riparian area management and definition of riparian buffer zones. However, the variation in diet niches amongst terrestrial consumers makes the results area-specific, and more studies are required that incorporate additional terrestrial predators in other fluvial systems so that we can make some generalizations on the dynamics of riparian trophic cross-boundary links.
- Full Text:
- Authors: Chari, Lenin Dzibakwe
- Date: 2016
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/55791 , vital:26734
- Description: This thesis characterises the cross-boundary trophic interactions of a relatively small model ecosystem, the Kowie River (Eastern Cape of South Africa), to explore their epistemic implications for systems ecology. Using web-building spiders and odonates (dragonflies and damselflies) as model organisms, I sought to investigate whether the diets of predators of aerial insects could be used to assess the strength of the trophic connectivity between freshwater and terrestrial systems in relation to variables such as stream width, distance from the river and aquatic insect emergence rates and abundances. Predator diet composition was determined by using a combination of diet analysis tools: direct observations of cross-subsidies, naturally-abundant stable (carbon and nitrogen) isotope analysis and fatty acid analysis. I also sought to reveal feeding niches and guilds among riparian aerial predators and investigate how the environment influenced predators’ access to aquatic prey subsidies. As emergent aquatic insect abundances decreased with an increase in distance from the river, and increased with stream width and seasonal changes from winter to summer, stable isotope and fatty acid analyses revealed distinct changes in web-building spider diet composition. Examination of the fatty acid eicosapentaenoic acid, a component commonly used as an indicator of consumer reliance on aquatic nutritional subsidies, showed that aquatic subsidies extended further inland at the wider sections of the river. Spiders and odonates at the wider sections of the Kowie River generally received more subsidies (56 – 70%) than those at the narrower sections (25 – 60%). When terrestrial insect biomass was distinctly low in winter, the benefit of aquatic subsidisation to spiders was relatively lower at the narrower sections of the Kowie River relative to the wide sections. As such, riparian areas adjacent to wide parts of the river were more likely to support larger populations of aerial predators than those at the narrow sections. Apart from the diet changes across time and space, there was evidence of inter-specific niche partitioning in both spiders and odonates, but no differences were observed between males and females of the same species. Results showed odonates of different sizes and hunting strategies had separate dietary niches, hence varied access to aquatic nutritional subsidies. The larger odonate taxa that frequently foraged mid-air had more varied diets and relied less on aquatic emergent insects than the smaller odonates that foraged from perches near the river. There was also evidence of niche partitioning amongst the spiders, as those that built horizontal webs captured more aquatic insects (40 – 78%) than the vertical orb-web builders (20 – 66%). This study showed that the nature and extent of trophic cross-boundary linkages in riparian areas largely depended on the availability of subsidies that varied seasonally and spatially. The width of the stream and seasonal variability emerged as important predictors of emergent insect abundances/biomasses that influenced predator feeding niches. The high mobility of odonates made their reliance on aquatic nutritional subsidies different from the less mobile spiders. The link between the width of the river and the extent of trophic connectivity has implications for riparian area management and definition of riparian buffer zones. However, the variation in diet niches amongst terrestrial consumers makes the results area-specific, and more studies are required that incorporate additional terrestrial predators in other fluvial systems so that we can make some generalizations on the dynamics of riparian trophic cross-boundary links.
- Full Text: