The classsification of fuzzy subgroups of some finite Abelian p-groups of rank 3
- Authors: Appiah, Isaac Kwadwo
- Date: 2016
- Subjects: Fuzzy sets Abelian groups Finite groups
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2468 , vital:27845
- Description: An important trend in fuzzy group theory in recent years has been the notion of classification of fuzzy subgroups using a suitable equivalence relation. In this dissertation, we have successfully used the natural equivalence relation defined by Murali and Makamba in [81] and a natural fuzzy isomorphism to classify fuzzy subgroups of some finite abelian p-groups of rank three of the form Zpn + Zp + Zp for any fixed prime integer p and any positive integer n. This was achieved through the usage of a suitable technique of enumerating distinct fuzzy subgroups and non-isomorphic fuzzy subgroups of G. We commence by giving a brief discussion on the theory of fuzzy sets and fuzzy subgroups from the perspective of group theory through to the theory of sets, leading us to establish a linkage among these theories. We have also shown in this dissertation that the converse of theorem 3.1 proposed by Das in [24] is incorrect by giving a counter example and restate the theorem. We have then reviewed and enriched the study conducted by Ngcibi in [94] by characterising the non-isomorphic fuzzy subgroups in that study. We have also developed a formula to compute the crisp subgroups of the under-studied group and provide its proof. Furthermore, we have compared the equivalence relation under which the classification problem is based with various versions of equivalence studied in the literature. We managed to use this counting technique to obtain explicit formulae for the number of maximal chains, distinct fuzzy subgroups, non-isomorphic maximal chains and non-isomorphic fuzzy subgroups of these groups and their proofs are provided.
- Full Text:
- Date Issued: 2016
- Authors: Appiah, Isaac Kwadwo
- Date: 2016
- Subjects: Fuzzy sets Abelian groups Finite groups
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2468 , vital:27845
- Description: An important trend in fuzzy group theory in recent years has been the notion of classification of fuzzy subgroups using a suitable equivalence relation. In this dissertation, we have successfully used the natural equivalence relation defined by Murali and Makamba in [81] and a natural fuzzy isomorphism to classify fuzzy subgroups of some finite abelian p-groups of rank three of the form Zpn + Zp + Zp for any fixed prime integer p and any positive integer n. This was achieved through the usage of a suitable technique of enumerating distinct fuzzy subgroups and non-isomorphic fuzzy subgroups of G. We commence by giving a brief discussion on the theory of fuzzy sets and fuzzy subgroups from the perspective of group theory through to the theory of sets, leading us to establish a linkage among these theories. We have also shown in this dissertation that the converse of theorem 3.1 proposed by Das in [24] is incorrect by giving a counter example and restate the theorem. We have then reviewed and enriched the study conducted by Ngcibi in [94] by characterising the non-isomorphic fuzzy subgroups in that study. We have also developed a formula to compute the crisp subgroups of the under-studied group and provide its proof. Furthermore, we have compared the equivalence relation under which the classification problem is based with various versions of equivalence studied in the literature. We managed to use this counting technique to obtain explicit formulae for the number of maximal chains, distinct fuzzy subgroups, non-isomorphic maximal chains and non-isomorphic fuzzy subgroups of these groups and their proofs are provided.
- Full Text:
- Date Issued: 2016
The consumption and use of wild foods by children across a deforestation gradient in Zomba District, Malawi
- Authors: Maseko, Heather Nonhlanhla
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3212 , vital:20392
- Description: Despite consensus on their significant nutritional value, wild foods are continually excluded from both food security statistics and economic values of natural resources. Though largely unexplored, there is evidence on the use of wild foods by children to supplement their diets and as a source of income. Children have knowledge on the gathering and hunting of selected wild food species and sources thereof. Wetlands, agro-ecosystems, natural forests, human landscapes and river systems remain important sources of wild food resources. The provision of and access to these resources are significantly affected by the interference and disruption to natural ecosystems. In Malawi, interference has been largely due to deforestation and land use change caused by an interplay of pressures from population growth for development and agricultural expansion. Against this background, the implications of deforestation and vegetation cover on the availability of wild foods and their access and use by children is largely unexplored. Through a comprehensive analysis of data collected from 150 children and 50 elderly men and women, the integration of Participatory Rural Appraisal (PRA) exercises and Geographic Information System (GIS), in the four sites of Mpheta, Mtuluma, Kasonga and Makombe in Zomba district, wild foods availability was established and their contribution to the nutritional status of children and households’ food security assessed. Study sites were identified along the deforestation gradient of Lake Chilwa, Zomba Mountain and Shire River basin with an additional focus on varying landscapes. One hundred and twenty species of wild foods were identified with greatest availability in areas of high vegetation cover and the lowest in areas of low vegetation cover, but with meaningful differences per wild food category. There was considerable reduction in the availability of wild foods with increasing deforestation; mainly wild game and fruits species and, in turn, decreased access of these by children. Nevertheless, small game, insects, other wild fruits and wild vegetables thrive well in agro-ecosystems and therefore were minimally affected by deforestation but largely by management practices of those systems and can be possibly improved through the promotion of agro-ecological farming systems. The research reveals that wild foods form an important component of the starch based diets of households from agricultural communities in the various landscapes. Besides securing the household’s food base, all children largely supplemented their diets with wild foods but with increased dependence by children from poorer households who are highly vulnerable to food insecurity. Access and use of wild foods was largely dependent on children’s knowledge, perceptions of the wild food and ease of access, with considerable variations due to gender and socio-cultural norms. Besides contributing to the nutritional status and food security, commercialisation of wild foods was common among children, hence providing them with an alternative livelihood strategy and in some cases only viable source of income.
- Full Text:
- Date Issued: 2016
- Authors: Maseko, Heather Nonhlanhla
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3212 , vital:20392
- Description: Despite consensus on their significant nutritional value, wild foods are continually excluded from both food security statistics and economic values of natural resources. Though largely unexplored, there is evidence on the use of wild foods by children to supplement their diets and as a source of income. Children have knowledge on the gathering and hunting of selected wild food species and sources thereof. Wetlands, agro-ecosystems, natural forests, human landscapes and river systems remain important sources of wild food resources. The provision of and access to these resources are significantly affected by the interference and disruption to natural ecosystems. In Malawi, interference has been largely due to deforestation and land use change caused by an interplay of pressures from population growth for development and agricultural expansion. Against this background, the implications of deforestation and vegetation cover on the availability of wild foods and their access and use by children is largely unexplored. Through a comprehensive analysis of data collected from 150 children and 50 elderly men and women, the integration of Participatory Rural Appraisal (PRA) exercises and Geographic Information System (GIS), in the four sites of Mpheta, Mtuluma, Kasonga and Makombe in Zomba district, wild foods availability was established and their contribution to the nutritional status of children and households’ food security assessed. Study sites were identified along the deforestation gradient of Lake Chilwa, Zomba Mountain and Shire River basin with an additional focus on varying landscapes. One hundred and twenty species of wild foods were identified with greatest availability in areas of high vegetation cover and the lowest in areas of low vegetation cover, but with meaningful differences per wild food category. There was considerable reduction in the availability of wild foods with increasing deforestation; mainly wild game and fruits species and, in turn, decreased access of these by children. Nevertheless, small game, insects, other wild fruits and wild vegetables thrive well in agro-ecosystems and therefore were minimally affected by deforestation but largely by management practices of those systems and can be possibly improved through the promotion of agro-ecological farming systems. The research reveals that wild foods form an important component of the starch based diets of households from agricultural communities in the various landscapes. Besides securing the household’s food base, all children largely supplemented their diets with wild foods but with increased dependence by children from poorer households who are highly vulnerable to food insecurity. Access and use of wild foods was largely dependent on children’s knowledge, perceptions of the wild food and ease of access, with considerable variations due to gender and socio-cultural norms. Besides contributing to the nutritional status and food security, commercialisation of wild foods was common among children, hence providing them with an alternative livelihood strategy and in some cases only viable source of income.
- Full Text:
- Date Issued: 2016
The contribution of smallholder agriculture production to food security in rural Zimbabwe : a case study of Masvingo Province
- Authors: Toringepi, Godfrey
- Date: 2016
- Subjects: Farms, Small -- Zimbabwe Agricultural productivity -- Zimbabwe Sustainable agriculture -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/5598 , vital:29350
- Description: Agricultural development is back on the development agenda. Even though the smallholder farmers are in the majority and at the forefront in terms of food production and agriculture being the backbone of the economy of Zimbabwe, there is no clearly defined policy on smallholder agriculture in Zimbabwe. The food insecurity has remained a continuous challenge for the rural poor in Zimbabwe. This study investigated the contribution of smallholder agriculture to food security with particular reference to the Masvingo province. The study employed qualitative method of research entailing extensive review of literature as a method of data collection. The study utilized the modernisation theory and sustainable livelihoods framework to illustrate smallholder agriculture and food security nexus. The study revealed that smallholder agriculture is the best option for addressing food security since agriculture is considered the main livelihood strategy for small scale farmers in Zimbabwe. There is general scholarly consensus that the main cause of food insecurity in Zimbabwe is a decrease in smallholder agriculture productivity. The study revealed that poor infrastructure , limited access to credit, limited access to inputs, poor investment in human development, limited access to markets and harsh climatic conditions weaken the capacity of small scale farmers to improve food security. Key recommendations are that supportive institutions need to be put in place to strengthen the smallholder farmer’s capacity to improve food security in Zimbabwe.
- Full Text:
- Date Issued: 2016
- Authors: Toringepi, Godfrey
- Date: 2016
- Subjects: Farms, Small -- Zimbabwe Agricultural productivity -- Zimbabwe Sustainable agriculture -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/5598 , vital:29350
- Description: Agricultural development is back on the development agenda. Even though the smallholder farmers are in the majority and at the forefront in terms of food production and agriculture being the backbone of the economy of Zimbabwe, there is no clearly defined policy on smallholder agriculture in Zimbabwe. The food insecurity has remained a continuous challenge for the rural poor in Zimbabwe. This study investigated the contribution of smallholder agriculture to food security with particular reference to the Masvingo province. The study employed qualitative method of research entailing extensive review of literature as a method of data collection. The study utilized the modernisation theory and sustainable livelihoods framework to illustrate smallholder agriculture and food security nexus. The study revealed that smallholder agriculture is the best option for addressing food security since agriculture is considered the main livelihood strategy for small scale farmers in Zimbabwe. There is general scholarly consensus that the main cause of food insecurity in Zimbabwe is a decrease in smallholder agriculture productivity. The study revealed that poor infrastructure , limited access to credit, limited access to inputs, poor investment in human development, limited access to markets and harsh climatic conditions weaken the capacity of small scale farmers to improve food security. Key recommendations are that supportive institutions need to be put in place to strengthen the smallholder farmer’s capacity to improve food security in Zimbabwe.
- Full Text:
- Date Issued: 2016
The design, development and evaluation of cross-platform mobile applications and services supporting social accountability monitoring
- Authors: Reynell, Edward Robin
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3652 , vital:20533
- Description: Local government processes require meaningful and effective participation from both citizens and their governments in order to remain truly democratic. This project investigates the use of mobile phones as a tool for supporting this participation. MobiSAM, a system which aims to enhance the Social Accountability Monitoring (SAM) methodology at local government level, has been designed and implemented. The research presented in this thesis examines tools and techniques for the development of cross-platform client applications, allowing access to the MobiSAM service, across heterogeneous mobile platforms, handsets and interaction styles. Particular attention is paid to providing an easily navigated user interface (UI), as well as offering clear and concise visualisation capabilities. Depending on the host device, interactivity is also included within these visualisations, potentially helping provide further insight into the visualised data. Guided by the results obtained from a comprehensive baseline study of the Grahamstown area, steps are taken in an attempt to lower the barrier of entry to using the MobiSAM service, potentially maximising its market reach. These include extending client application support to all identified mobile platforms (including feature phones); providing multi-language UIs (in English, isiXhosa and Afrikaans); as well as ensuring client application data usage is kept to a minimum. The particular strengths of a given device are also leveraged, such as its camera capabilities and built-in Global Positioning System (GPS) module, potentially allowing for more effective engagement with local municipalities. Additionally, a Short Message Service (SMS) gateway is developed, allowing all Global System for Mobile Communications (GSM) compatible handsets access to the MobiSAM service via traditional SMS. Following an iterative, user-centred design process, a thorough evaluation of the client application is also performed, in an attempt to gather feedback relating to the navigation and visualisation capabilities. The results of which are used to further refine its design. A comparative usability evaluation using two different versions of the cross-platform client application is also undertaken, highlighting the perceived memorability, learnabilitv and satisfaction of each. Results from the evaluation reveals which version of the client application is to be deployed during future pilot studies.
- Full Text:
- Date Issued: 2016
- Authors: Reynell, Edward Robin
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3652 , vital:20533
- Description: Local government processes require meaningful and effective participation from both citizens and their governments in order to remain truly democratic. This project investigates the use of mobile phones as a tool for supporting this participation. MobiSAM, a system which aims to enhance the Social Accountability Monitoring (SAM) methodology at local government level, has been designed and implemented. The research presented in this thesis examines tools and techniques for the development of cross-platform client applications, allowing access to the MobiSAM service, across heterogeneous mobile platforms, handsets and interaction styles. Particular attention is paid to providing an easily navigated user interface (UI), as well as offering clear and concise visualisation capabilities. Depending on the host device, interactivity is also included within these visualisations, potentially helping provide further insight into the visualised data. Guided by the results obtained from a comprehensive baseline study of the Grahamstown area, steps are taken in an attempt to lower the barrier of entry to using the MobiSAM service, potentially maximising its market reach. These include extending client application support to all identified mobile platforms (including feature phones); providing multi-language UIs (in English, isiXhosa and Afrikaans); as well as ensuring client application data usage is kept to a minimum. The particular strengths of a given device are also leveraged, such as its camera capabilities and built-in Global Positioning System (GPS) module, potentially allowing for more effective engagement with local municipalities. Additionally, a Short Message Service (SMS) gateway is developed, allowing all Global System for Mobile Communications (GSM) compatible handsets access to the MobiSAM service via traditional SMS. Following an iterative, user-centred design process, a thorough evaluation of the client application is also performed, in an attempt to gather feedback relating to the navigation and visualisation capabilities. The results of which are used to further refine its design. A comparative usability evaluation using two different versions of the cross-platform client application is also undertaken, highlighting the perceived memorability, learnabilitv and satisfaction of each. Results from the evaluation reveals which version of the client application is to be deployed during future pilot studies.
- Full Text:
- Date Issued: 2016
The design, management and testing of a solar vehicle's energy strategy
- Authors: Jordaan, Johan
- Date: 2016
- Subjects: Solar energy -- Hybrid systems , Renewable energy sources
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/7428 , vital:21362
- Description: In recent years the interest in implementing solar energy on vehicles (electrical and hybrid) has grown significantly [1]. There are currently limitations in this sector, such as the low energy density (efficiency of conversion) of this source, but it is still a renewable resource and as such, there is a growing interest [1]. A “smart” energy strategy implemented on a solar/electrical vehicle, in order to increase its energy harvesting volume, could enhance the growth of this sector. A tracking algorithm for a solar vehicle’s MPPT (Maximum Power Point Tracker) can be designed to source solar energy very effectively and to increase the speed of finding (tracking) this optimal sourcing point (solar panel voltage and current). Even though there are many different MPPT algorithms, it was decided that most of them were designed for stationary MPPT applications and the dynamics of implementing a MPPT on a vehicle create some unique scenarios. These include: Shadow flicker. This is rhythmic, rapid moving shadows across a solar panel, such as shadows from a line of trees: Rapid changes in solar panel orientation due to the road surface/relief; Rapid changes in panel temperature due to the location of the vehicle. The aim of the research can be divided into three outcomes: 1 Creating a “Smart” energy strategy/control, 2 Implement the new control system on a solar vehicle’s MPPT, and 3 Harvesting maximum energy from solar panels using the new energy strategy. The term “smart” is used to indicate the ability of the MPPT algorithm to be updated and improved based on previous results. A MPPT and scaled solar vehicle is designed and manufactured in order to test the MPPT algorithm. The purpose of using a self-developed experimental setup is to have more control over the system variables as well as having the maximum freedom in setting up the system parameters.
- Full Text:
- Date Issued: 2016
- Authors: Jordaan, Johan
- Date: 2016
- Subjects: Solar energy -- Hybrid systems , Renewable energy sources
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/7428 , vital:21362
- Description: In recent years the interest in implementing solar energy on vehicles (electrical and hybrid) has grown significantly [1]. There are currently limitations in this sector, such as the low energy density (efficiency of conversion) of this source, but it is still a renewable resource and as such, there is a growing interest [1]. A “smart” energy strategy implemented on a solar/electrical vehicle, in order to increase its energy harvesting volume, could enhance the growth of this sector. A tracking algorithm for a solar vehicle’s MPPT (Maximum Power Point Tracker) can be designed to source solar energy very effectively and to increase the speed of finding (tracking) this optimal sourcing point (solar panel voltage and current). Even though there are many different MPPT algorithms, it was decided that most of them were designed for stationary MPPT applications and the dynamics of implementing a MPPT on a vehicle create some unique scenarios. These include: Shadow flicker. This is rhythmic, rapid moving shadows across a solar panel, such as shadows from a line of trees: Rapid changes in solar panel orientation due to the road surface/relief; Rapid changes in panel temperature due to the location of the vehicle. The aim of the research can be divided into three outcomes: 1 Creating a “Smart” energy strategy/control, 2 Implement the new control system on a solar vehicle’s MPPT, and 3 Harvesting maximum energy from solar panels using the new energy strategy. The term “smart” is used to indicate the ability of the MPPT algorithm to be updated and improved based on previous results. A MPPT and scaled solar vehicle is designed and manufactured in order to test the MPPT algorithm. The purpose of using a self-developed experimental setup is to have more control over the system variables as well as having the maximum freedom in setting up the system parameters.
- Full Text:
- Date Issued: 2016
The development of captopril pellets using the principles of quality by design
- Veerubhotla, Hari Mani Krishna
- Authors: Veerubhotla, Hari Mani Krishna
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/64769 , vital:28599
- Description: Expected release date-May 2018
- Full Text:
- Date Issued: 2016
- Authors: Veerubhotla, Hari Mani Krishna
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/64769 , vital:28599
- Description: Expected release date-May 2018
- Full Text:
- Date Issued: 2016
The development of rhenium nanoradiopharmaceuticals
- Authors: Ntsimango, Songeziwe
- Date: 2016
- Subjects: Rhenium -- South Africa Radiopharmaceuticals -- South Africa , Nanoparticles -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/13017 , vital:27144
- Description: The dissertation details the experimental work on the attempt to develop rhenium(V)phthalocyanine complexes directly from its +7 oxidation state (perrhenate). Different reducing agents (PPh3, Na2S2O5 and NaBH4) were employed and consequently, different results were acquired, such as rhenium(V)-mediated oxidative hydrolysis of the phthalocyanines (Pcs), the formation of a rhenium-phthalocyanine complex and phthalocyanine-capped nanoparticles. The rhenium nanoparticles that were formed were optimized from a synthesis point of view and, cancer localizing ability of the rhenium nanoparticles was investigated. The complexes were synthesized through direct metalation of pre-formed metal-free phthalocyanines using the “cold isotopes” of the rhenium metal. Rhenium nanoparticles (Re NPs) were synthesized in aqueous saline medium so as to imitate the environment on which Re is produced from its reactor. The nanoparticles (NPs) were capped with phthalocyanines which were covalently biofunctionalized with a folic acid moiety to enhance the targeting ability of the Re NPs. These NP systems were characterised with techniques such as ultraviolet-visible UV-Vis spectroscopy and transmission electron microscopy TEM. Cytotoxicity of the NPs was tested against four different cell lines and subsequently their cytotoxicity profiles were elucidated, and the profiles shown a dose-dependent responsealthough the results in some cell lines were unclear. Their fluorescence properties were also studied to provide photophysical information for investigation of their tumor localization using human cancer cells lines via confocal fluorescence microscopy studies. Particle size effect on localization of NPs was also investigated using confocal fluorescence and TEM. Two sizes were chosen (10 and 50 nm), and the smaller NPs (10 nm) were found to exhibit stronger fluorescence properties than the 50 nm NPs, and they were also found to have a better localization ability than the 50 nm NPs. Finally, their tumor and organ biodistribution studies will be carried out using micro-SPECT kits and model mice (using the “hot” isotopes in a radiopharmacy laboratory).
- Full Text:
- Date Issued: 2016
- Authors: Ntsimango, Songeziwe
- Date: 2016
- Subjects: Rhenium -- South Africa Radiopharmaceuticals -- South Africa , Nanoparticles -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/13017 , vital:27144
- Description: The dissertation details the experimental work on the attempt to develop rhenium(V)phthalocyanine complexes directly from its +7 oxidation state (perrhenate). Different reducing agents (PPh3, Na2S2O5 and NaBH4) were employed and consequently, different results were acquired, such as rhenium(V)-mediated oxidative hydrolysis of the phthalocyanines (Pcs), the formation of a rhenium-phthalocyanine complex and phthalocyanine-capped nanoparticles. The rhenium nanoparticles that were formed were optimized from a synthesis point of view and, cancer localizing ability of the rhenium nanoparticles was investigated. The complexes were synthesized through direct metalation of pre-formed metal-free phthalocyanines using the “cold isotopes” of the rhenium metal. Rhenium nanoparticles (Re NPs) were synthesized in aqueous saline medium so as to imitate the environment on which Re is produced from its reactor. The nanoparticles (NPs) were capped with phthalocyanines which were covalently biofunctionalized with a folic acid moiety to enhance the targeting ability of the Re NPs. These NP systems were characterised with techniques such as ultraviolet-visible UV-Vis spectroscopy and transmission electron microscopy TEM. Cytotoxicity of the NPs was tested against four different cell lines and subsequently their cytotoxicity profiles were elucidated, and the profiles shown a dose-dependent responsealthough the results in some cell lines were unclear. Their fluorescence properties were also studied to provide photophysical information for investigation of their tumor localization using human cancer cells lines via confocal fluorescence microscopy studies. Particle size effect on localization of NPs was also investigated using confocal fluorescence and TEM. Two sizes were chosen (10 and 50 nm), and the smaller NPs (10 nm) were found to exhibit stronger fluorescence properties than the 50 nm NPs, and they were also found to have a better localization ability than the 50 nm NPs. Finally, their tumor and organ biodistribution studies will be carried out using micro-SPECT kits and model mice (using the “hot” isotopes in a radiopharmacy laboratory).
- Full Text:
- Date Issued: 2016
The dynamics of microalgal communities in response to environmental variables and nutrient fluxes in ephemeral wetlands in the Nelson Mandela Bay Metropole
- Authors: Lategan, Jodi
- Date: 2016
- Subjects: Vernal pool ecology -- South Africa -- Nelson Mandela Bay Municipality Vernal pools -- South Africa -- Nelson Mandela Bay Municipality. , patial ecology -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/13138 , vital:27155
- Description: Ephemeral wetlands provide numerous ecosystem services, but are disappearing due to urbanisation and habitat fragmentation. Knowledge is required to conserve these systems, but ephemeral wetland research in South Africa is lacking. As primary producers, microalgae provide a key link between the biotic and abiotic components of aquatic ecosystems. Despite their importance, there is a paucity in information concerning microalgal dynamics in ephemeral wetlands. The aim of this study was to understand the spatial and temporal dynamics of microalgae in ephemeral wetlands of the Nelson Mandela Bay Metropole. The research followed a funnel-based approach that assessed 35 wetlands at a regional level, followed by a temporal assessment of six wetlands, monitored biweekly, monthly or quarterly. Thereafter, a case study at local scale was carried out to address wetland connectivity and Hydrogeomorphic unit trends. The research culminated in a benthic flux chamber experiment, addressing the influence of microalgal-mediated processes on wetland development for a month post inundation. Phytoplankton biomass showed strong regional associations with rainfall zone, with Chl a concentrations of 17; 4.6; and 25 µg.L-1 in the high, intermediate and low rainfall zones, respectively. The MPB communities in Seeps, Depressions and Wetland flats, comprised between 45 and 60 % diatoms, whilst other microalgal groups were dominant in the water columns (> 90 %). Phytoplankton and MPB interactions facilitated significant night-time NH4+ and SRP effluxes, (1.5 and 0.4 mg.m-2.h-1, respectively) four days post inundation. High Silica uptake in the latter stages, was attributed to an increase in diatom abundance. Within the chambers, MPB growth was continuous whilst phytoplankton exhibited cyclical growth as the system approached dynamic equilibrium. This study demonstrated the importance of nutrient cycling in structuring aquatic food webs, and indicated the sensitivity of ephemeral wetlands to environmental perturbations.
- Full Text:
- Date Issued: 2016
- Authors: Lategan, Jodi
- Date: 2016
- Subjects: Vernal pool ecology -- South Africa -- Nelson Mandela Bay Municipality Vernal pools -- South Africa -- Nelson Mandela Bay Municipality. , patial ecology -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/13138 , vital:27155
- Description: Ephemeral wetlands provide numerous ecosystem services, but are disappearing due to urbanisation and habitat fragmentation. Knowledge is required to conserve these systems, but ephemeral wetland research in South Africa is lacking. As primary producers, microalgae provide a key link between the biotic and abiotic components of aquatic ecosystems. Despite their importance, there is a paucity in information concerning microalgal dynamics in ephemeral wetlands. The aim of this study was to understand the spatial and temporal dynamics of microalgae in ephemeral wetlands of the Nelson Mandela Bay Metropole. The research followed a funnel-based approach that assessed 35 wetlands at a regional level, followed by a temporal assessment of six wetlands, monitored biweekly, monthly or quarterly. Thereafter, a case study at local scale was carried out to address wetland connectivity and Hydrogeomorphic unit trends. The research culminated in a benthic flux chamber experiment, addressing the influence of microalgal-mediated processes on wetland development for a month post inundation. Phytoplankton biomass showed strong regional associations with rainfall zone, with Chl a concentrations of 17; 4.6; and 25 µg.L-1 in the high, intermediate and low rainfall zones, respectively. The MPB communities in Seeps, Depressions and Wetland flats, comprised between 45 and 60 % diatoms, whilst other microalgal groups were dominant in the water columns (> 90 %). Phytoplankton and MPB interactions facilitated significant night-time NH4+ and SRP effluxes, (1.5 and 0.4 mg.m-2.h-1, respectively) four days post inundation. High Silica uptake in the latter stages, was attributed to an increase in diatom abundance. Within the chambers, MPB growth was continuous whilst phytoplankton exhibited cyclical growth as the system approached dynamic equilibrium. This study demonstrated the importance of nutrient cycling in structuring aquatic food webs, and indicated the sensitivity of ephemeral wetlands to environmental perturbations.
- Full Text:
- Date Issued: 2016
The effect of novel thiazole-derived small molecules on the neuronal differentiation of human neuroblastoma SH-SY5Y cells
- Authors: Joos-Vandewalle, Julia
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/64507 , vital:28554
- Description: Expected release date-April 2020
- Full Text:
- Date Issued: 2016
- Authors: Joos-Vandewalle, Julia
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/64507 , vital:28554
- Description: Expected release date-April 2020
- Full Text:
- Date Issued: 2016
The effects of turtle-introduced nutrients on beach ecosystems
- Le Gouvello Du Timat, Diane Zelica Marie
- Authors: Le Gouvello Du Timat, Diane Zelica Marie
- Date: 2016
- Subjects: Sea turtles , Sea turtles -- Conservation , Green turtle
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/6959 , vital:21175
- Description: Resource subsidies are flows of nutrients from one ecosystem to another. Sandy beach ecosystems are at the interface between land and sea and thus receive nutrients from both land/seascapes. The seasonal nesting of sea turtles introduces large inputs of eggs, and so nutrients, onto sandy beach ecosystems, but little is known about the effects of these spatially and temporally variable nutrient input pulses on the dynamics of consumers in the recipient system. In this study, I examined the ecological role of sea turtles as vectors of nutrients that introduce large amounts of nutrients (in the form of eggs) from distant foraging grounds into nutrient-poor beach ecosystems. Although some of the nutrients return to the sea in the form of hatchlings, nutrients from unhatched and depredated eggs, dead and predated hatchlings, as well as chorioallantoic fluid and egg shells remain on the beach and presumably enter sandy beach food webs. I hypothesized that turtle nutrients significantly increase the availability of nutrients to sandy beach ecosystems and that those nutrients are incorporated by both terrestrial and marine food webs. These hypotheses were tested by comparing isotopic signatures of 13C and 15N of consumers on beaches with high and low turtle nest densities. The response of meiofauna to the decomposition of turtle eggs was also investigated. I predicted that meiofaunal abundance is positively affected by turtle nutrients and that higher meiofaunal abundances will be obtained in decomposing, depredated nests. I tested this hypothesis by comparing meiofaunal abundance in naturally predated nests to densities away from turtle nests (as a control). An in situ experiment that mimics conditions of naturally predated sea turtle nest, was set up to test meiofaunal community responses to turtle nutrients over time. The study indicates that sea turtle eggs represent a short pulsed resource subsidy that increases the nutrient and energy budget of sandy beach ecosystems. The results show that of the five potential nutrient pathways tested, ghost crabs appear to consume egg nutrients in measurable quantities, altering their diet and feeding behaviour according to food availability. The study also showed that there was a strong, but short-lived positive response of meiofauna to the introduction of nutrients, with increased abundance of all taxa in predated nests and experimental treatments. This response was particularly strong for nematodes which peaked in abundance after seven days. I conclude that turtle-derived nutrients represent a pulsed resource subsidy that makes significant contribution to the energy budget of sandy beach/dune ecosystems.
- Full Text:
- Date Issued: 2016
- Authors: Le Gouvello Du Timat, Diane Zelica Marie
- Date: 2016
- Subjects: Sea turtles , Sea turtles -- Conservation , Green turtle
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/6959 , vital:21175
- Description: Resource subsidies are flows of nutrients from one ecosystem to another. Sandy beach ecosystems are at the interface between land and sea and thus receive nutrients from both land/seascapes. The seasonal nesting of sea turtles introduces large inputs of eggs, and so nutrients, onto sandy beach ecosystems, but little is known about the effects of these spatially and temporally variable nutrient input pulses on the dynamics of consumers in the recipient system. In this study, I examined the ecological role of sea turtles as vectors of nutrients that introduce large amounts of nutrients (in the form of eggs) from distant foraging grounds into nutrient-poor beach ecosystems. Although some of the nutrients return to the sea in the form of hatchlings, nutrients from unhatched and depredated eggs, dead and predated hatchlings, as well as chorioallantoic fluid and egg shells remain on the beach and presumably enter sandy beach food webs. I hypothesized that turtle nutrients significantly increase the availability of nutrients to sandy beach ecosystems and that those nutrients are incorporated by both terrestrial and marine food webs. These hypotheses were tested by comparing isotopic signatures of 13C and 15N of consumers on beaches with high and low turtle nest densities. The response of meiofauna to the decomposition of turtle eggs was also investigated. I predicted that meiofaunal abundance is positively affected by turtle nutrients and that higher meiofaunal abundances will be obtained in decomposing, depredated nests. I tested this hypothesis by comparing meiofaunal abundance in naturally predated nests to densities away from turtle nests (as a control). An in situ experiment that mimics conditions of naturally predated sea turtle nest, was set up to test meiofaunal community responses to turtle nutrients over time. The study indicates that sea turtle eggs represent a short pulsed resource subsidy that increases the nutrient and energy budget of sandy beach ecosystems. The results show that of the five potential nutrient pathways tested, ghost crabs appear to consume egg nutrients in measurable quantities, altering their diet and feeding behaviour according to food availability. The study also showed that there was a strong, but short-lived positive response of meiofauna to the introduction of nutrients, with increased abundance of all taxa in predated nests and experimental treatments. This response was particularly strong for nematodes which peaked in abundance after seven days. I conclude that turtle-derived nutrients represent a pulsed resource subsidy that makes significant contribution to the energy budget of sandy beach/dune ecosystems.
- Full Text:
- Date Issued: 2016
The efficacy of a community based eccentric hamstring strengthening program in peri-urban Black South African soccer players
- Authors: Ryan, Bennett
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3573 , vital:20526
- Description: Introduction: Hamstring injury prevalence in soccer remains a major concern. Research in this context has focused on Caucasian populations with little attention given to other ethnic groups. The compatibility and applicability of such research to the South African context, particularly at an amateur level, may be minimal due to fundamental differences in physical characteristics, as well as complexities with regards to implementation. The aim of this investigation was therefore twofold. 1) Identify the lower extremity strength and performance profile of Peri-urban Amateur South African Players, and 2) Assess the efficacy of a community based intervention through the use of the Nordic Hamstring Exercise. Methods: 19 Black male Eastern Cape amateur players participated in a 12 week randomly controlled trial (9 = Control, 10 = Intervention). All participants completed regular training, while the intervention group, in addition, performed the Nordic Hamstring exercise post warm up. The incremental program design was taken from Mjolsnes et al. (2004), with a progressive increase in both sets and repetitions. Compliance was defined as completion of the required exercises for that session. Isokinetic strength evaluations (at 60°.s-1 and 180°.s-1) including assessment of peak torque and total work, as well as performance measures of countermovement and squat jump, were completed pre and post intervention, with the profile of the Peri-urban player the combined responses of both groups at baseline. Additionally, both the functional ratio (Eccentric Hamstrings/Concentric Quadriceps) and eccentric utilization ratio (Countermovement Jump/Squat Jump) were calculated. Results: Concentric quadriceps peak torque at baseline reported values of 195 (±22) Nm and 141 (±21) Nm at 60°.s-1 and 180°.s-1. Values of 162 (±21) Nm were observed for peak torque of the eccentric hamstrings at 60°.s-1, while 157 (±18) Nm was indicated at 180°.s-1. Mean functional ratio responses were observed as 0.83 (±0.11) and 1.12 (±0.16) for 60°.s-1 and 180°.s-1 respectively. Additionally, the eccentric utilization ratio responses were recorded as 1.04 (±0.08). Regarding the intervention, concentric quadriceps total work of the dominant limb significantly improved over the time course of experimentation within the intervention group. Other quadriceps variables, concentric hamstrings, squat jump capability and performance measures all reported no significant changes (p>0.05) over the course of assessment when compared to the control. Eccentric hamstrings peak torque observed significant improvements (p<0.05) of between 5.72 and 12.82 % within the intervention group, while the countermovement jump indicated a significant 15.59 % increase (p<0.05). Additionally, the functional ratio and the eccentric utilization ratio both indicated no significant changes (p>0.05), with a 2.48-7.66 % and 5.33 % improvement noted following completion of assessment. Conclusion: Isokinetic responses at baseline observed decreased quadriceps strength, and increased hamstring strength when compared to both amateur and professional populations examined in previous studies, for both isokinetic testing speeds. Additionally, performance measures indicated similar responses to other amateur populations. Regarding the intervention, significant improvements in eccentric hamstring peak torque and countermovement jump indicate the partial success of the present intervention. Additionally, while the functional ratio and eccentric utilization ratio reported no significant changes, improvements were noted within the intervention group while the control noted no change. The Nordic hamstring lower therefore resulted in strength improvements within the eccentric hamstrings, reported as a significant factor for injury risk, however, such changes were not sufficient to significantly impact the functional ratio. It can be concluded that community based programs within South Africa have the potential to be effective; however, there are many barriers to implementation, including, language, ethnic and cultural differences, while a lack of resources and infrastructure play a significant role in a lack of development. More research of this nature is required to provide scientific support for structures and guidelines for the peri-urban community based South African player, to ensure the efficacy of internationally successful interventions such as the Nordic exercise.
- Full Text:
- Date Issued: 2016
- Authors: Ryan, Bennett
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3573 , vital:20526
- Description: Introduction: Hamstring injury prevalence in soccer remains a major concern. Research in this context has focused on Caucasian populations with little attention given to other ethnic groups. The compatibility and applicability of such research to the South African context, particularly at an amateur level, may be minimal due to fundamental differences in physical characteristics, as well as complexities with regards to implementation. The aim of this investigation was therefore twofold. 1) Identify the lower extremity strength and performance profile of Peri-urban Amateur South African Players, and 2) Assess the efficacy of a community based intervention through the use of the Nordic Hamstring Exercise. Methods: 19 Black male Eastern Cape amateur players participated in a 12 week randomly controlled trial (9 = Control, 10 = Intervention). All participants completed regular training, while the intervention group, in addition, performed the Nordic Hamstring exercise post warm up. The incremental program design was taken from Mjolsnes et al. (2004), with a progressive increase in both sets and repetitions. Compliance was defined as completion of the required exercises for that session. Isokinetic strength evaluations (at 60°.s-1 and 180°.s-1) including assessment of peak torque and total work, as well as performance measures of countermovement and squat jump, were completed pre and post intervention, with the profile of the Peri-urban player the combined responses of both groups at baseline. Additionally, both the functional ratio (Eccentric Hamstrings/Concentric Quadriceps) and eccentric utilization ratio (Countermovement Jump/Squat Jump) were calculated. Results: Concentric quadriceps peak torque at baseline reported values of 195 (±22) Nm and 141 (±21) Nm at 60°.s-1 and 180°.s-1. Values of 162 (±21) Nm were observed for peak torque of the eccentric hamstrings at 60°.s-1, while 157 (±18) Nm was indicated at 180°.s-1. Mean functional ratio responses were observed as 0.83 (±0.11) and 1.12 (±0.16) for 60°.s-1 and 180°.s-1 respectively. Additionally, the eccentric utilization ratio responses were recorded as 1.04 (±0.08). Regarding the intervention, concentric quadriceps total work of the dominant limb significantly improved over the time course of experimentation within the intervention group. Other quadriceps variables, concentric hamstrings, squat jump capability and performance measures all reported no significant changes (p>0.05) over the course of assessment when compared to the control. Eccentric hamstrings peak torque observed significant improvements (p<0.05) of between 5.72 and 12.82 % within the intervention group, while the countermovement jump indicated a significant 15.59 % increase (p<0.05). Additionally, the functional ratio and the eccentric utilization ratio both indicated no significant changes (p>0.05), with a 2.48-7.66 % and 5.33 % improvement noted following completion of assessment. Conclusion: Isokinetic responses at baseline observed decreased quadriceps strength, and increased hamstring strength when compared to both amateur and professional populations examined in previous studies, for both isokinetic testing speeds. Additionally, performance measures indicated similar responses to other amateur populations. Regarding the intervention, significant improvements in eccentric hamstring peak torque and countermovement jump indicate the partial success of the present intervention. Additionally, while the functional ratio and eccentric utilization ratio reported no significant changes, improvements were noted within the intervention group while the control noted no change. The Nordic hamstring lower therefore resulted in strength improvements within the eccentric hamstrings, reported as a significant factor for injury risk, however, such changes were not sufficient to significantly impact the functional ratio. It can be concluded that community based programs within South Africa have the potential to be effective; however, there are many barriers to implementation, including, language, ethnic and cultural differences, while a lack of resources and infrastructure play a significant role in a lack of development. More research of this nature is required to provide scientific support for structures and guidelines for the peri-urban community based South African player, to ensure the efficacy of internationally successful interventions such as the Nordic exercise.
- Full Text:
- Date Issued: 2016
The EPR paradox: back from the future
- Authors: Bryan, Kate Louise Halse
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/2881 , vital:20338
- Description: The Einstein-Podolsky-Rosen (EPR) thought experiment produced a problem regarding the interpretation of quantum mechanics provided for entangled systems. Although the thought experiment was reformulated mathematically in Bell's Theorem, the conclusion regarding entanglement correlations is still debated today. In an attempt to provide an explanation of how entangled systems maintain their correlations, this thesis investigates the theory of post-state teleportation as a possible interpretation of how information moves between entangled systems without resorting to nonlocal action. Post-state teleportation describes a method of communicating to the past via a quantum information channel. The resulting picture of the EPR thought experiment relied on information propagating backward from a final boundary condition to ensure all correlations were maintained. Similarities were found between this resolution of the EPR paradox and the final state solution to the black hole information paradox and the closely related firewall problem. The latter refers to an apparent conflict between unitary evaporation of a black hole and the strong subadditivity condition. The use of observer complementarity allows this solution of the black hole problem to be shown to be the same as a seemingly different solution known as “ER=EPR", where ‘ER’ refers to an Einstein-Rosen bridge or wormhole.
- Full Text:
- Date Issued: 2016
- Authors: Bryan, Kate Louise Halse
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/2881 , vital:20338
- Description: The Einstein-Podolsky-Rosen (EPR) thought experiment produced a problem regarding the interpretation of quantum mechanics provided for entangled systems. Although the thought experiment was reformulated mathematically in Bell's Theorem, the conclusion regarding entanglement correlations is still debated today. In an attempt to provide an explanation of how entangled systems maintain their correlations, this thesis investigates the theory of post-state teleportation as a possible interpretation of how information moves between entangled systems without resorting to nonlocal action. Post-state teleportation describes a method of communicating to the past via a quantum information channel. The resulting picture of the EPR thought experiment relied on information propagating backward from a final boundary condition to ensure all correlations were maintained. Similarities were found between this resolution of the EPR paradox and the final state solution to the black hole information paradox and the closely related firewall problem. The latter refers to an apparent conflict between unitary evaporation of a black hole and the strong subadditivity condition. The use of observer complementarity allows this solution of the black hole problem to be shown to be the same as a seemingly different solution known as “ER=EPR", where ‘ER’ refers to an Einstein-Rosen bridge or wormhole.
- Full Text:
- Date Issued: 2016
The GARCH-EVT-Copula model and simulation in scenario-based asset allocation
- McEwan, Peter Gareth Fredric
- Authors: McEwan, Peter Gareth Fredric
- Date: 2016
- Subjects: Extreme value theory GARCH model
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/11732 , vital:26961
- Description: Financial market integration, in particular, portfolio allocations from advanced economies to South African markets, continues to strengthen volatility linkages and quicken volatility transmissions between participating markets. Largely as a result, South African portfolios are net recipients of returns and volatility shocks emanating from major world markets. In light of these, and other, sources of risk, this dissertation proposes a methodology to improve risk management systems in funds by building a contemporary asset allocation framework that offers practitioners an opportunity to explicitly model combinations of hypothesised global risks and the effects on their investments. The framework models portfolio return variables and their key risk driver variables separately and then joins them to model their combined dependence structure. The separate modelling of univariate and multivariate (MV) components admits the benefit of capturing the data generating processes with improved accuracy. Univariate variables were modelled using ARMA-GARCH-family structures paired with a variety of skewed and leptokurtic conditional distributions. Model residuals were fit using the Peaks-over-Threshold method from Extreme Value Theory for the tails and a non-parametric, kernel density for the interior, forming a completed semi-parametric distribution (SPD) for each variable. Asset and risk factor returns were then combined and their dependence structure jointly modelled with a MV Student t copula. Finally, the SPD margins and Student t copula were used to construct a MV meta t distribution. Monte Carlo simulations were generated from the fitted MV meta t distribution on which an out-of-sample test was conducted. The 2014-to-2015 horizon served to proxy as an out-of-sample, forward-looking scenario for a set of key risk factors against which a hypothetical, diversified portfolio was optimised. Traditional mean-variance and contemporary mean-CVaR optimisation techniques were used and their results compared. As an addendum, performance over the in-sample 2008 financial crisis was reported. The final Objective (7) addressed management and conservation strategies for the NMBM. The NMBM wetland database that was produced during this research is currently being used by the Municipality and will be added to the latest National Wetland Map. From the database, and tools developed in this research, approximately 90 wetlands have been identified as being highly vulnerable due to anthropogenic and environmental factors (Chapter 6) and should be earmarked as key conservation priority areas. Based on field experience and data collected, this study has also made conservation and rehabilitation recommendations for eight locations. Recommendations are also provided for six more wetland systems (or regions) that should be prioritised for further research, as these systems lack fundamental information on where the threat of anthropogenic activities affecting them is greatest. This study has made a significant contribution to understanding the underlying geomorphological processes in depressions, seeps and wetland flats. The desktop mapping component of this study illustrated the dominance of wetlands in the wetter parts of the Municipality. Perched wetland systems were identified in the field, on shallow bedrock, calcrete or clay. The prevalence of these perches in depressions, seeps and wetland flats also highlighted the importance of rainfall in driving wetland formation, by allowing water to pool on these perches, in the NMBM. These perches are likely to be a key factor in the high number of small, ephemeral wetlands that were observed in the study area, compared to other semi-arid regions. Therefore, this research highlights the value of multi-faceted and multi-scalar wetland research and how similar approaches should be used in future research methods has been highlighted. The approach used, along with the tools/methods developed in this study have facilitated the establishment of priority areas for conservation and management within the NMBM. Furthermore, the research approach has revealed emergent wetland properties that are only apparent when looking at different spatial scales. This research has highlighted the complex biological and geomorphological interactions between wetlands that operate over various spatial and temporal scales. As such, wetland management should occur across a wetland complex, rather than individual sites, to account for these multi-scalar influences.
- Full Text:
- Date Issued: 2016
- Authors: McEwan, Peter Gareth Fredric
- Date: 2016
- Subjects: Extreme value theory GARCH model
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/11732 , vital:26961
- Description: Financial market integration, in particular, portfolio allocations from advanced economies to South African markets, continues to strengthen volatility linkages and quicken volatility transmissions between participating markets. Largely as a result, South African portfolios are net recipients of returns and volatility shocks emanating from major world markets. In light of these, and other, sources of risk, this dissertation proposes a methodology to improve risk management systems in funds by building a contemporary asset allocation framework that offers practitioners an opportunity to explicitly model combinations of hypothesised global risks and the effects on their investments. The framework models portfolio return variables and their key risk driver variables separately and then joins them to model their combined dependence structure. The separate modelling of univariate and multivariate (MV) components admits the benefit of capturing the data generating processes with improved accuracy. Univariate variables were modelled using ARMA-GARCH-family structures paired with a variety of skewed and leptokurtic conditional distributions. Model residuals were fit using the Peaks-over-Threshold method from Extreme Value Theory for the tails and a non-parametric, kernel density for the interior, forming a completed semi-parametric distribution (SPD) for each variable. Asset and risk factor returns were then combined and their dependence structure jointly modelled with a MV Student t copula. Finally, the SPD margins and Student t copula were used to construct a MV meta t distribution. Monte Carlo simulations were generated from the fitted MV meta t distribution on which an out-of-sample test was conducted. The 2014-to-2015 horizon served to proxy as an out-of-sample, forward-looking scenario for a set of key risk factors against which a hypothetical, diversified portfolio was optimised. Traditional mean-variance and contemporary mean-CVaR optimisation techniques were used and their results compared. As an addendum, performance over the in-sample 2008 financial crisis was reported. The final Objective (7) addressed management and conservation strategies for the NMBM. The NMBM wetland database that was produced during this research is currently being used by the Municipality and will be added to the latest National Wetland Map. From the database, and tools developed in this research, approximately 90 wetlands have been identified as being highly vulnerable due to anthropogenic and environmental factors (Chapter 6) and should be earmarked as key conservation priority areas. Based on field experience and data collected, this study has also made conservation and rehabilitation recommendations for eight locations. Recommendations are also provided for six more wetland systems (or regions) that should be prioritised for further research, as these systems lack fundamental information on where the threat of anthropogenic activities affecting them is greatest. This study has made a significant contribution to understanding the underlying geomorphological processes in depressions, seeps and wetland flats. The desktop mapping component of this study illustrated the dominance of wetlands in the wetter parts of the Municipality. Perched wetland systems were identified in the field, on shallow bedrock, calcrete or clay. The prevalence of these perches in depressions, seeps and wetland flats also highlighted the importance of rainfall in driving wetland formation, by allowing water to pool on these perches, in the NMBM. These perches are likely to be a key factor in the high number of small, ephemeral wetlands that were observed in the study area, compared to other semi-arid regions. Therefore, this research highlights the value of multi-faceted and multi-scalar wetland research and how similar approaches should be used in future research methods has been highlighted. The approach used, along with the tools/methods developed in this study have facilitated the establishment of priority areas for conservation and management within the NMBM. Furthermore, the research approach has revealed emergent wetland properties that are only apparent when looking at different spatial scales. This research has highlighted the complex biological and geomorphological interactions between wetlands that operate over various spatial and temporal scales. As such, wetland management should occur across a wetland complex, rather than individual sites, to account for these multi-scalar influences.
- Full Text:
- Date Issued: 2016
The impact of three different footwear conditions on individual biomechanical, physiological and perceptual responses during running.
- Authors: McDougall, Justin John
- Date: 2016
- Subjects: Running -- Physiological aspects , Running shoes -- Physiological aspects , Running -- Health aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5177 , http://hdl.handle.net/10962/d1019988
- Description: Background: Despite the introduction of running footwear in the 1970’s, running injury rates continue to be unacceptably high. The subsequent revival of barefoot running and the introduction of minimalist footwear occurred, in an attempt to reduce injury rates and increase performance. There is much contention in the literature around the effectiveness of these footwear conditions. Furthermore individual responses have recently been proposed to provide more accurate and reflective conclusions than the use of mean data. Objectives: Twofold: a) to compare the biomechanical, physiological and perceptual responses between the shod, minimalist and barefoot footwear conditions and b) to assess and compare individual responses under these footwear conditions. Methods: 26 well-trained, male, habitually shod endurance runners, aged between 18 - 30 years completed three experimental sessions on an indoor runway and motorized treadmill. Each session was completed in either the shod, minimalist or barefoot condition, running at 15km.h-1. Variables assessed included stride rate, stride length, impact peak, vertical impact and average loading rate and strike time (biomechanical); heart rate, oxygen consumption and electromyography (physiological); and rating of perceived exertion and body discomfort (perceptual). Results: Biomechanics – Stride rate and stride length showed a significant (p<0.001) increase and decrease respectively when running in the minimalist or barefoot conditions versus shod. Running barefoot versus the minimalist and shod conditions resulted in a significantly (p<0.001) greater vertical impact loading rate. Strike time was significantly (p=0.008) reduced running in the minimalist and barefoot conditions versus shod. Physiology – Running barefoot versus shod resulted in a significantly (p=0.02) reduced heart rate and Tibialis Anterior activity (p=0.005). There was a large variability in individual responses for many variables, with responders and non-responders seen. Conclusion: The study suggests that there are significant differences between all three forms of running for some variables. It was further noted that there is support for the proposal that individual responses are highly variable and should be analysed accordingly
- Full Text:
- Date Issued: 2016
- Authors: McDougall, Justin John
- Date: 2016
- Subjects: Running -- Physiological aspects , Running shoes -- Physiological aspects , Running -- Health aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5177 , http://hdl.handle.net/10962/d1019988
- Description: Background: Despite the introduction of running footwear in the 1970’s, running injury rates continue to be unacceptably high. The subsequent revival of barefoot running and the introduction of minimalist footwear occurred, in an attempt to reduce injury rates and increase performance. There is much contention in the literature around the effectiveness of these footwear conditions. Furthermore individual responses have recently been proposed to provide more accurate and reflective conclusions than the use of mean data. Objectives: Twofold: a) to compare the biomechanical, physiological and perceptual responses between the shod, minimalist and barefoot footwear conditions and b) to assess and compare individual responses under these footwear conditions. Methods: 26 well-trained, male, habitually shod endurance runners, aged between 18 - 30 years completed three experimental sessions on an indoor runway and motorized treadmill. Each session was completed in either the shod, minimalist or barefoot condition, running at 15km.h-1. Variables assessed included stride rate, stride length, impact peak, vertical impact and average loading rate and strike time (biomechanical); heart rate, oxygen consumption and electromyography (physiological); and rating of perceived exertion and body discomfort (perceptual). Results: Biomechanics – Stride rate and stride length showed a significant (p<0.001) increase and decrease respectively when running in the minimalist or barefoot conditions versus shod. Running barefoot versus the minimalist and shod conditions resulted in a significantly (p<0.001) greater vertical impact loading rate. Strike time was significantly (p=0.008) reduced running in the minimalist and barefoot conditions versus shod. Physiology – Running barefoot versus shod resulted in a significantly (p=0.02) reduced heart rate and Tibialis Anterior activity (p=0.005). There was a large variability in individual responses for many variables, with responders and non-responders seen. Conclusion: The study suggests that there are significant differences between all three forms of running for some variables. It was further noted that there is support for the proposal that individual responses are highly variable and should be analysed accordingly
- Full Text:
- Date Issued: 2016
The implications of the 2014 construction regulations for the Department of Public Works procurement system
- Authors: Matete, Kenevoe Rose
- Date: 2016
- Subjects: Construction industry -- Safety regulations -- South Africa Construction industry -- Standards -- South Africa Industrial procurement -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/10309 , vital:26651
- Description: The Organisation of Economic Co-operation and Development (OECD) notes that regulations seek to make improvements by changing individual or organisational behaviour in ways that generate positive impacts in terms of solving societal and economic problems. At its most basic level, regulations are designed to work according to implementation, leading to changes in behaviours that, in turn, lead to changes in outcomes. Such outcomes can be satisfaction in terms of an underlying problem or other (hopefully positive) changes in conditions in the world. Following this premise, this research project investigates the implications of the 2014 Construction Regulations for the Department of Public Works’ procurement system. The study also examines the contents of the construction Regulations; the impact of the Construction Regulations 2014 – permit-to-work; client / contractor procurement issues; the enforcement of compliance to permit-to-work requirements, and education and training demands in relation to health and safety (H&S) competency. The study shows that even though industry role players are relatively familiar with the Construction Regulations 2014, there is a common concern regarding competency (education and training) levels required for the implementation of the permit-to-work requirement of the regulations. The concerns focus on the ability of the Department of Labour (DoL) to process the permits. Based on the study’s findings, the research concludes that there would be cost implications for project actors when implementing the permit-to-work requirement and this cost factor could delay project initiation and planning, as well as service delivery.
- Full Text:
- Date Issued: 2016
- Authors: Matete, Kenevoe Rose
- Date: 2016
- Subjects: Construction industry -- Safety regulations -- South Africa Construction industry -- Standards -- South Africa Industrial procurement -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/10309 , vital:26651
- Description: The Organisation of Economic Co-operation and Development (OECD) notes that regulations seek to make improvements by changing individual or organisational behaviour in ways that generate positive impacts in terms of solving societal and economic problems. At its most basic level, regulations are designed to work according to implementation, leading to changes in behaviours that, in turn, lead to changes in outcomes. Such outcomes can be satisfaction in terms of an underlying problem or other (hopefully positive) changes in conditions in the world. Following this premise, this research project investigates the implications of the 2014 Construction Regulations for the Department of Public Works’ procurement system. The study also examines the contents of the construction Regulations; the impact of the Construction Regulations 2014 – permit-to-work; client / contractor procurement issues; the enforcement of compliance to permit-to-work requirements, and education and training demands in relation to health and safety (H&S) competency. The study shows that even though industry role players are relatively familiar with the Construction Regulations 2014, there is a common concern regarding competency (education and training) levels required for the implementation of the permit-to-work requirement of the regulations. The concerns focus on the ability of the Department of Labour (DoL) to process the permits. Based on the study’s findings, the research concludes that there would be cost implications for project actors when implementing the permit-to-work requirement and this cost factor could delay project initiation and planning, as well as service delivery.
- Full Text:
- Date Issued: 2016
The importance of habitat use in the foraging behaviour of village chacma baboons (Papio ursinus, Cercopithecidae: Primates) in Hogsback, Eastern Cape
- Authors: Pamla, Lwandiso
- Date: 2016
- Subjects: Chacma baboon -- Behavior -- South Africa -- Eastern Cape Cercopithecidae Primates -- Behavior
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8055 , vital:31494
- Description: Baboons are among the most widespread primates in Africa because they are able to adapt their foraging behaviour and omnivorous diet under challenging and changing conditions. They are attracted by food, shelter and water on human-owned properties, which brings them into conflict with the residents in Hogsback, Eastern Cape, South Africa, and results in them being shot, trapped or poisoned. To quantify the proportion of food baboons obtain from raiding human properties and to assess the quality of this food, I recorded activity budgets for foraging and movement in two free-ranging troops (Evie’s and Nola’s troops) using direct field observation. I determined home range sizes using GIS methods. I hypothesised that a troop that frequents more human-modified areas should have smaller home ranges, higher densities and forage less than a troop that spends more time in natural habitats, irrespective of troop size, because of more readily accessible food sources. The three methods I used (100 percent minimum convex method, 95 percent fixed kernel method and quadrat method) revealed that Evie’s troop used more human-modified habitat, but had a larger home range than Nola’s troop. The troop sizes have been stable for the past four years: at last count, Evie’s troop had 47 individuals and Nola’s, 38 individuals. During my field study I also recorded diverse vocalisations made by the animals, as an aid to detecting and identifying the troops and understanding individual interactions. Responses to the presence of baboons of many of the local residents – whether affluent and living on semi-urban estates, or impoverished and hunting for food – do not augur well for the future of Hogsback’s baboons. Affluent residents with horticultural gardens occasionally shoot baboons that venture on to their properties, while rural occupants hunt baboons in their natural environment. Both of these responses cause troop disruption and decreased troop size, possibly leading to local troop extinctions.
- Full Text:
- Date Issued: 2016
- Authors: Pamla, Lwandiso
- Date: 2016
- Subjects: Chacma baboon -- Behavior -- South Africa -- Eastern Cape Cercopithecidae Primates -- Behavior
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8055 , vital:31494
- Description: Baboons are among the most widespread primates in Africa because they are able to adapt their foraging behaviour and omnivorous diet under challenging and changing conditions. They are attracted by food, shelter and water on human-owned properties, which brings them into conflict with the residents in Hogsback, Eastern Cape, South Africa, and results in them being shot, trapped or poisoned. To quantify the proportion of food baboons obtain from raiding human properties and to assess the quality of this food, I recorded activity budgets for foraging and movement in two free-ranging troops (Evie’s and Nola’s troops) using direct field observation. I determined home range sizes using GIS methods. I hypothesised that a troop that frequents more human-modified areas should have smaller home ranges, higher densities and forage less than a troop that spends more time in natural habitats, irrespective of troop size, because of more readily accessible food sources. The three methods I used (100 percent minimum convex method, 95 percent fixed kernel method and quadrat method) revealed that Evie’s troop used more human-modified habitat, but had a larger home range than Nola’s troop. The troop sizes have been stable for the past four years: at last count, Evie’s troop had 47 individuals and Nola’s, 38 individuals. During my field study I also recorded diverse vocalisations made by the animals, as an aid to detecting and identifying the troops and understanding individual interactions. Responses to the presence of baboons of many of the local residents – whether affluent and living on semi-urban estates, or impoverished and hunting for food – do not augur well for the future of Hogsback’s baboons. Affluent residents with horticultural gardens occasionally shoot baboons that venture on to their properties, while rural occupants hunt baboons in their natural environment. Both of these responses cause troop disruption and decreased troop size, possibly leading to local troop extinctions.
- Full Text:
- Date Issued: 2016
The influence of aspirations on changing livelihood strategies in rural households of Ndabakazi villages in the Eastern Cape
- Authors: Zantsi, Siphe
- Date: 2016
- Subjects: Households -- Economic aspects -- South Africa -- Eastern Cape Rural development projects -- South Africa -- Eastern Cape Sustainable development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/5653 , vital:29357
- Description: The objective of this study is to explore the role of aspirations on changing livelihood strategies of rural households of Ndabakazi villages in the Eastern Cape. A sample of 80 respondents was chosen randomly for the household survey and semi-structured questionnaires were used to collect the data. Focus group discussions were also used to supplement the household survey. The data was descriptively analysed using a triangulation method. The findings show that social grants, mainly pensions and non-farm employment, and child support grants are the major sources of income. The majority of the households own five hectares of land and more, in which they grow crops only in gardens adjacent to their homes. However, 29 percent do not produce any crops at all. Farming contributes a small portion to the household income. The choice of farming is more powerful than the external factors. Interest in farming is minimal and can be related to the declining farming activities; therefore, household aspirations have an influence on changing livelihood aspirations. In the case of the rural areas of Ndabakazi – as indeed in many other parts of South Africa - policies of rural development mostly take a top-down approach; as a result most of these policies do not become effective in achieving the intended outcome. Development practitioners should incorporate beneficiaries when planning so as to tailor the development initiatives with the aspirations of local people for them to be effect and achieve intended goals thus a bottom-up approach. The notion that rural household farming activities have declined because they lack inputs, farming implements other necessary support is not always true. Some households are not interested in farming and they cannot be forced.
- Full Text:
- Date Issued: 2016
- Authors: Zantsi, Siphe
- Date: 2016
- Subjects: Households -- Economic aspects -- South Africa -- Eastern Cape Rural development projects -- South Africa -- Eastern Cape Sustainable development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/5653 , vital:29357
- Description: The objective of this study is to explore the role of aspirations on changing livelihood strategies of rural households of Ndabakazi villages in the Eastern Cape. A sample of 80 respondents was chosen randomly for the household survey and semi-structured questionnaires were used to collect the data. Focus group discussions were also used to supplement the household survey. The data was descriptively analysed using a triangulation method. The findings show that social grants, mainly pensions and non-farm employment, and child support grants are the major sources of income. The majority of the households own five hectares of land and more, in which they grow crops only in gardens adjacent to their homes. However, 29 percent do not produce any crops at all. Farming contributes a small portion to the household income. The choice of farming is more powerful than the external factors. Interest in farming is minimal and can be related to the declining farming activities; therefore, household aspirations have an influence on changing livelihood aspirations. In the case of the rural areas of Ndabakazi – as indeed in many other parts of South Africa - policies of rural development mostly take a top-down approach; as a result most of these policies do not become effective in achieving the intended outcome. Development practitioners should incorporate beneficiaries when planning so as to tailor the development initiatives with the aspirations of local people for them to be effect and achieve intended goals thus a bottom-up approach. The notion that rural household farming activities have declined because they lack inputs, farming implements other necessary support is not always true. Some households are not interested in farming and they cannot be forced.
- Full Text:
- Date Issued: 2016
The maturity of project management in engineering consulting firms
- Authors: Machite, Kennedy
- Date: 2016
- Subjects: Project management Consulting engineers -- South Africa , Engineering firms -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/18409 , vital:28634
- Description: With a considerable number of built environment projects not being completed successfully, this study was undertaken to investigate how effectively consulting engineering firms are applying project management principles in the way they manage projects. This was achieved by measuring the project management maturity levels of consulting engineering firms. Maturity levels were measured for each of the ten knowledge areas of the Project Management Institute’s Project Management Body of Knowledge to determine areas where consulting engineering firms perform below expectation and as a result determine probable causes of project failures. The maturity of the firm was then calculated as the average of the maturity for the knowledge areas. The study found that consulting engineering firms have higher levels of project management maturity than the average for the construction and civil engineering sector. Apart from risk and procurement management, all the other knowledge areas have higher maturity levels than the corresponding construction and civil engineering knowledge areas. Although the overall maturity results indicate that the larger firms are more mature in their project management practices than the smaller firms, the individual knowledge areas are inconsistent. The study reveals that consulting engineering firms are weakest in the risk management, human resources and stakeholder management knowledge areas. There is limited literature available on the status of project management, project management methodologies, and performance of consulting projects in the engineering environment (Labuschagne & Steyn, 2010:70). There is need for future studies to establish a methodology developed specifically for the Consulting Engineering Firms in line with what Labuschagne & Steyn (2010) started and a Project Management Maturity Model specific to the Consulting Engineering Industry.
- Full Text:
- Date Issued: 2016
- Authors: Machite, Kennedy
- Date: 2016
- Subjects: Project management Consulting engineers -- South Africa , Engineering firms -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/18409 , vital:28634
- Description: With a considerable number of built environment projects not being completed successfully, this study was undertaken to investigate how effectively consulting engineering firms are applying project management principles in the way they manage projects. This was achieved by measuring the project management maturity levels of consulting engineering firms. Maturity levels were measured for each of the ten knowledge areas of the Project Management Institute’s Project Management Body of Knowledge to determine areas where consulting engineering firms perform below expectation and as a result determine probable causes of project failures. The maturity of the firm was then calculated as the average of the maturity for the knowledge areas. The study found that consulting engineering firms have higher levels of project management maturity than the average for the construction and civil engineering sector. Apart from risk and procurement management, all the other knowledge areas have higher maturity levels than the corresponding construction and civil engineering knowledge areas. Although the overall maturity results indicate that the larger firms are more mature in their project management practices than the smaller firms, the individual knowledge areas are inconsistent. The study reveals that consulting engineering firms are weakest in the risk management, human resources and stakeholder management knowledge areas. There is limited literature available on the status of project management, project management methodologies, and performance of consulting projects in the engineering environment (Labuschagne & Steyn, 2010:70). There is need for future studies to establish a methodology developed specifically for the Consulting Engineering Firms in line with what Labuschagne & Steyn (2010) started and a Project Management Maturity Model specific to the Consulting Engineering Industry.
- Full Text:
- Date Issued: 2016
The phytogeography of Southern Mistbelt Forests of the Eastern Cape, South Africa
- Authors: Matiwane, Aviwe
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3224 , vital:20393
- Description: In the Eastern Cape, a moisture gradient (from west to east) exists along the Escarpment where patches of Southern Mistbelt Forests (SMF) occur. There is a notable profusion of plants in these forests, but the factors that drive plant species composition and abundance in these patches is poorly understood and such knowledge is critical if we are to address or mitigate the problems imposed by global change. Many of our ideas on plant community assembly are based on the premise that species differ in their environmental requirements for successful regeneration, especially when young. The aims of this study were to document the floristic diversity of poorly known patches of Southern Mistbelt Forests in the Eastern Cape and identify the environmental factors that influence plant community composition in these forest patches. Twenty six forest patches across the Eastern Cape were sampled. In each forest 400m2 circular plots were constructed. The diameter at breast height and stem counts for the tree species was taken and the % cover of the herbaceous species was recorded. General collections were also made to supplement the plot data in order to obtain a comprehensive flora for each forest patch. All sampling was done during the summer season of 2013 and 2014. Using plot data, Hierarchal Cluster Analysis and Multidimensional Scaling Analysis were done to compare similarities between patches. Plots from the same forest patch clustered which indicated that the species composition in each forest patch was unique. However, this pattern went down when only tree species were considered. Plant diversity also varied between patches; with those located in the east being generally more diverse than those in the west are. Clustering patterns in fragmented communities and differences in species diversity indicate evidence of species “nestedness”. Analysis of nestedness indicated that these forest patches were significantly nested. To identify which environmental variables might be correlated with both species diversity and nestedness, twelve environmental variables was selected for analysis using Canonical Correspondence Analysis and Principal Component Analysis. Results show that Mean Annual Precipitation, Mean Annual Potential Evapotranspiration, and percentage of Organic Matter of the soil were most strongly correlated with the patterns of diversity observed in these forest patches. Regression analysis indicated that Mean Annual Precipitation accounted for most of the variation in species diversity, especially for the herbaceous species. The herbaceous species thus show a greater sensitivity to “climate filtering” as a consequence of rainfall gradients. With the implementation of suitable monitoring programs, changes in abundance or even local extinction of these species can act as an early warning indicator of the possible long-term effects of climate change on forest communities.
- Full Text:
- Date Issued: 2016
- Authors: Matiwane, Aviwe
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3224 , vital:20393
- Description: In the Eastern Cape, a moisture gradient (from west to east) exists along the Escarpment where patches of Southern Mistbelt Forests (SMF) occur. There is a notable profusion of plants in these forests, but the factors that drive plant species composition and abundance in these patches is poorly understood and such knowledge is critical if we are to address or mitigate the problems imposed by global change. Many of our ideas on plant community assembly are based on the premise that species differ in their environmental requirements for successful regeneration, especially when young. The aims of this study were to document the floristic diversity of poorly known patches of Southern Mistbelt Forests in the Eastern Cape and identify the environmental factors that influence plant community composition in these forest patches. Twenty six forest patches across the Eastern Cape were sampled. In each forest 400m2 circular plots were constructed. The diameter at breast height and stem counts for the tree species was taken and the % cover of the herbaceous species was recorded. General collections were also made to supplement the plot data in order to obtain a comprehensive flora for each forest patch. All sampling was done during the summer season of 2013 and 2014. Using plot data, Hierarchal Cluster Analysis and Multidimensional Scaling Analysis were done to compare similarities between patches. Plots from the same forest patch clustered which indicated that the species composition in each forest patch was unique. However, this pattern went down when only tree species were considered. Plant diversity also varied between patches; with those located in the east being generally more diverse than those in the west are. Clustering patterns in fragmented communities and differences in species diversity indicate evidence of species “nestedness”. Analysis of nestedness indicated that these forest patches were significantly nested. To identify which environmental variables might be correlated with both species diversity and nestedness, twelve environmental variables was selected for analysis using Canonical Correspondence Analysis and Principal Component Analysis. Results show that Mean Annual Precipitation, Mean Annual Potential Evapotranspiration, and percentage of Organic Matter of the soil were most strongly correlated with the patterns of diversity observed in these forest patches. Regression analysis indicated that Mean Annual Precipitation accounted for most of the variation in species diversity, especially for the herbaceous species. The herbaceous species thus show a greater sensitivity to “climate filtering” as a consequence of rainfall gradients. With the implementation of suitable monitoring programs, changes in abundance or even local extinction of these species can act as an early warning indicator of the possible long-term effects of climate change on forest communities.
- Full Text:
- Date Issued: 2016
The potential use of baobab (Adansonia digitata) seedcake as a commercial diet replacement and in feed formulation for broiler chickens
- Authors: Nxele, Sibusiso Kabelo
- Date: 2016
- Subjects: Broilers (Chickens) Adansonia digitata Chickens -- Feeding and feeds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12259 , vital:39224
- Description: This dissertation is composed of two trials that were aimed at evaluating the effects of partially supplementing Baobab seed cake in broiler diets. In the first trail, performance and cost analysis of feeding birds a commercial starter diet from day-old to 21-days of age; then feeding a blend of the commercial finisher diet diluted by a mixture of baobab seedcake and ground maize from day 22nd to 35th were evaluated. The trial was conducted in an environmentally controlled deep litter housing system using 160 Ross 308 chicks of mixed sex that were randomly allocated into 4 treatments consisting of 16 pens of 1X2m2 area per pen, within similar environmental conditions. The trial diets were formulated as follows: T1 was 100 percent standard commercial starter diet, as a control; T2 had 95 percent (112g) commercial starter diet and 5 percent BSC-maize blend (2g BSC: 4g Maize); T3 had 85 percent (102g) of the commercial starter diet and 18percent BSC-maize blend (6g BSC + 12g Maize); and T4 had 75 percent commercial starter diet and 25 percent BSC-maize blend (10g BSC + 20g Maize). All diets (T1, T2, T3 and T4) percentages were calculated based on 120g being 100 percent of the diet. Each treatment consisted of 40 birds and 4 replicates, each replicate consisting of 10 birds per pen. Feed and clean water were provided ad libitum. Feed allocation and body weights were measured at placement, then weekly. Feed intakes (FI), body weight gain (BWG) and feed conversion ratio (FCR) were calculated; then the cost analysis of feeding each diet was conducted. No significant differences (P>0.05) were found amongst all growth performance parameters. The cost efficient treatment to feed, which accumulated the cheapest cost of feed per weight gain (R33.62/kg gain) was T2 (5percent BSC+MM). The second trial was conducted to evaluate the effect of feeding diets containing graded levels of baoabab (A. digitata) seedcake on performance, apparent digestibility and digestive organ weights of broilers chickens. A total of 200 Ross 308 day-old chicks of mixed sex were randomly allocated into 4 treatment groups (T1, T2, T3 and T4). The trial diets were as follows: T1 (control), was a commercial starter diet; while T2, T3 and T4 diets contained baobab seedcake meal at 0, 5, 10, and 15percent; respectively. Inclusion of BSC in diets only affected FI during the first and third weeks. In the first week, FI had significant differences (P < 0.05) during the first and third week of the trial, respectively. Birds in T4 had the least FI, while those in T3 had the highest (P<0.05). In the third week, T3 birds had the highest FI (P<0.05), while T1 birds had the lowest. Significant differences for changes in bodyweight were only evident in the second and forth weeks of the study. During week 2, birds in T had the highest BWG, whereas T4 birds had the lowest (P<0.05); however, in week 4, there were no statistical differences (P>0.05) amongst birds in T1, T2 and T4; respectively, while T4 had the lowest BWG (P<0.05). The FCR was not statistically different among treatment groups, except in week 3, where it was highest in T4birds with T3 birds having the lowest (P<0.05). No significant differences (P>0.05) were observed among treatment groups for all parameters that were considered for digestibility and digestive organ weights. Due to the fact that two different trials were conducted, it was concluded that blend of baobab seedcake and maize from the first trial can be supplemented up to 5 percent replacement level for optimum production; while up to 10 percent baobab seedcake graded level can be used on the second trial without resulting in any negative consequences on growth performance, nutrient utilization and digestive organ weights.
- Full Text:
- Date Issued: 2016
- Authors: Nxele, Sibusiso Kabelo
- Date: 2016
- Subjects: Broilers (Chickens) Adansonia digitata Chickens -- Feeding and feeds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12259 , vital:39224
- Description: This dissertation is composed of two trials that were aimed at evaluating the effects of partially supplementing Baobab seed cake in broiler diets. In the first trail, performance and cost analysis of feeding birds a commercial starter diet from day-old to 21-days of age; then feeding a blend of the commercial finisher diet diluted by a mixture of baobab seedcake and ground maize from day 22nd to 35th were evaluated. The trial was conducted in an environmentally controlled deep litter housing system using 160 Ross 308 chicks of mixed sex that were randomly allocated into 4 treatments consisting of 16 pens of 1X2m2 area per pen, within similar environmental conditions. The trial diets were formulated as follows: T1 was 100 percent standard commercial starter diet, as a control; T2 had 95 percent (112g) commercial starter diet and 5 percent BSC-maize blend (2g BSC: 4g Maize); T3 had 85 percent (102g) of the commercial starter diet and 18percent BSC-maize blend (6g BSC + 12g Maize); and T4 had 75 percent commercial starter diet and 25 percent BSC-maize blend (10g BSC + 20g Maize). All diets (T1, T2, T3 and T4) percentages were calculated based on 120g being 100 percent of the diet. Each treatment consisted of 40 birds and 4 replicates, each replicate consisting of 10 birds per pen. Feed and clean water were provided ad libitum. Feed allocation and body weights were measured at placement, then weekly. Feed intakes (FI), body weight gain (BWG) and feed conversion ratio (FCR) were calculated; then the cost analysis of feeding each diet was conducted. No significant differences (P>0.05) were found amongst all growth performance parameters. The cost efficient treatment to feed, which accumulated the cheapest cost of feed per weight gain (R33.62/kg gain) was T2 (5percent BSC+MM). The second trial was conducted to evaluate the effect of feeding diets containing graded levels of baoabab (A. digitata) seedcake on performance, apparent digestibility and digestive organ weights of broilers chickens. A total of 200 Ross 308 day-old chicks of mixed sex were randomly allocated into 4 treatment groups (T1, T2, T3 and T4). The trial diets were as follows: T1 (control), was a commercial starter diet; while T2, T3 and T4 diets contained baobab seedcake meal at 0, 5, 10, and 15percent; respectively. Inclusion of BSC in diets only affected FI during the first and third weeks. In the first week, FI had significant differences (P < 0.05) during the first and third week of the trial, respectively. Birds in T4 had the least FI, while those in T3 had the highest (P<0.05). In the third week, T3 birds had the highest FI (P<0.05), while T1 birds had the lowest. Significant differences for changes in bodyweight were only evident in the second and forth weeks of the study. During week 2, birds in T had the highest BWG, whereas T4 birds had the lowest (P<0.05); however, in week 4, there were no statistical differences (P>0.05) amongst birds in T1, T2 and T4; respectively, while T4 had the lowest BWG (P<0.05). The FCR was not statistically different among treatment groups, except in week 3, where it was highest in T4birds with T3 birds having the lowest (P<0.05). No significant differences (P>0.05) were observed among treatment groups for all parameters that were considered for digestibility and digestive organ weights. Due to the fact that two different trials were conducted, it was concluded that blend of baobab seedcake and maize from the first trial can be supplemented up to 5 percent replacement level for optimum production; while up to 10 percent baobab seedcake graded level can be used on the second trial without resulting in any negative consequences on growth performance, nutrient utilization and digestive organ weights.
- Full Text:
- Date Issued: 2016