Muscle nanostructure, fat colour related fatty acids and Check-All-That-Apply visual profiling of South African A2 beef longissimus
- Authors: Soji, Zimkhitha
- Date: 2019
- Subjects: Meat -- Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15264 , vital:40332
- Description: The main objective of this study was to determine the effect of muscle nanostructure on tenderness, fat colour related fatty acids and Check-All-That-Apply visual profiling of South African A2 beef longissimus. Fifty two A-class steers (n=52) of five breeds (Bonsmara (n=19), Beef master (n=7), Hereford (n=9) and Simbra (n=17)) typically processed in different South African feedlots were studied. The animals were humanely slaughtered at an abattoir following the commercial standard procedures. Fat colour measurements (CIE b*) were taken at the P8 site on hot carcasses at the abattoir. Carcass mass (warm and cold) was recorded at the slaughter line before chilling (warm) and after chilling (cold) while pH0 and temperature were measured at 45 minutes post-mortem on the Longissimus thoracis et lumborum (LTL) muscle. Thereafter, a 20 g subsection of the LTL muscle on the left side of each carcass was sampled for muscle nanostructure analysis. At 24 hours post-slaughter, ultimate pH (pH24) was measured, further subsections of the LTL muscle (20 g) were harvested for further muscle nanostructure analysis and 2.5 kg of the LTL muscle was also harvested for analysis of tenderness, fatty acids and sensory evaluation. The muscle nanostructure (myofibril diameter (MYD), myofibril spacing (MYS), muscle fibre diameter (MFD), muscle fibre spacing (MFS) and sarcomere length (SL)) was analysed using the scanning electron microscope (SEM) while tenderness was measured using Warner Bratzler Shear Force after 45mins, 24hrs, 3 and 7 days aging period at -20 ºC refrigerator temperature. Some proximate fractions (total extractable intramuscular fat (Fat %), Fat Free Dry matter (FFDM %) and Moisture content) and fatty acid profile were measured using extracted fat and fatty acid indices (desaturase index, atherogenicity index) were calculated. Lastly a Check-All-That-Apply visual profiling method rated by an 80-member consumer panel was done to assess consumer meat preferences and perceptions of Bonsmara, Hereford and Simbra A2 fresh steaks. At 45mins post-slaughter breed affected (P<0.05) MYD and MYS, while at 24hrs breed affected MFD and MFS only. Early post-mortem pH (pH0) had no effect on the muscle nanostructure and tenderness while ultimate pH (pH24) affected MYD and MYS only. Muscle temperature at 45mins affected (P<0.05) the MYD, MFD and MFS, while 24hrs muscle temperature affected (P<0.05) MYD only. Tenderness was not related to the muscle nanostructure early post-mortem and there was no uniformity on the changes in muscle nanostructure and tenderness from early post-mortem to 24hrs against the multifaceted carcass mass, muscle pH and temperature effects. During ageing, breed affected the MYD and MYS at 45mins, while at 24hrs in addition to the myofibril structure breed also had an effect on muscle fibre bundle characteristics (MFD and MFS). The changes in MYD, MYS and MFS became constant on day 3 while variations in the MFD still progressed. There was no uniformity on the SL pattern during ageing and a very weak linear relationship between tenderness, SL, MFD and MFS was observed. Notably there was also no uniformity on how the muscle texture features; including the surface structure, fibre separation, and the mechanism of muscle contraction and relaxation; changed throughout the ageing period across and within the breeds. Moreover, breed had a significant effect on pentadecyclic acid, total saturated fatty acids (SFA) and docosahexanoic acid. Differences (P<0.05) in SFA, monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), n-6, n-3, fatty acid ratios, and desaturase index were observed among the white, creamy-white and creamy fat colour. The distribution of fatty acid classes was SFA>MUFA>PUFA in descending order of concentrations of mean values (44.19:40.06:15.75, respectively), while the n-6: n-3 ratio was 12:1. In sensory evaluation, consumers indicated how they would prefer to pay premium for meat with guaranteed muscle and fat colour, low fat content, high marbling and tenderness. Consumers observed breed differences (P<0.05) in muscle fibre separation and muscle colour. The overall liking of each attribute was more on moderate bright cherry red lean colour, moderate yellow fat, very abundant marbling and slight separation of muscle fibres. Differences on discrete liking of each attribute among consumers had an effect on the overall liking of each steak with Hereford steaks being more preferred by consumers. It was concluded that meat from beef animals within the same feeding regime has a different fatty acid composition owing to different breed synthetic pathways and feed ingredients and that meat tenderness is not affected by the muscle nanostructure early post-mortem. However, during ageing, meat tenderness is directly linked to breed related myofibril structure changes in particular the myofibril diameter, spacing between myofibrils and their interaction; while the muscle texture features, fibre diameter, spacing between muscle fibres and sarcomere length explain the non-uniformity of beef tenderness. Also the organoleptic and health related quality of meat assumed more importance among consumers in sensory evaluation. Thus meat classification systems should include more credence aspects or indicators that support credence quality of meat
- Full Text:
- Date Issued: 2019
- Authors: Soji, Zimkhitha
- Date: 2019
- Subjects: Meat -- Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15264 , vital:40332
- Description: The main objective of this study was to determine the effect of muscle nanostructure on tenderness, fat colour related fatty acids and Check-All-That-Apply visual profiling of South African A2 beef longissimus. Fifty two A-class steers (n=52) of five breeds (Bonsmara (n=19), Beef master (n=7), Hereford (n=9) and Simbra (n=17)) typically processed in different South African feedlots were studied. The animals were humanely slaughtered at an abattoir following the commercial standard procedures. Fat colour measurements (CIE b*) were taken at the P8 site on hot carcasses at the abattoir. Carcass mass (warm and cold) was recorded at the slaughter line before chilling (warm) and after chilling (cold) while pH0 and temperature were measured at 45 minutes post-mortem on the Longissimus thoracis et lumborum (LTL) muscle. Thereafter, a 20 g subsection of the LTL muscle on the left side of each carcass was sampled for muscle nanostructure analysis. At 24 hours post-slaughter, ultimate pH (pH24) was measured, further subsections of the LTL muscle (20 g) were harvested for further muscle nanostructure analysis and 2.5 kg of the LTL muscle was also harvested for analysis of tenderness, fatty acids and sensory evaluation. The muscle nanostructure (myofibril diameter (MYD), myofibril spacing (MYS), muscle fibre diameter (MFD), muscle fibre spacing (MFS) and sarcomere length (SL)) was analysed using the scanning electron microscope (SEM) while tenderness was measured using Warner Bratzler Shear Force after 45mins, 24hrs, 3 and 7 days aging period at -20 ºC refrigerator temperature. Some proximate fractions (total extractable intramuscular fat (Fat %), Fat Free Dry matter (FFDM %) and Moisture content) and fatty acid profile were measured using extracted fat and fatty acid indices (desaturase index, atherogenicity index) were calculated. Lastly a Check-All-That-Apply visual profiling method rated by an 80-member consumer panel was done to assess consumer meat preferences and perceptions of Bonsmara, Hereford and Simbra A2 fresh steaks. At 45mins post-slaughter breed affected (P<0.05) MYD and MYS, while at 24hrs breed affected MFD and MFS only. Early post-mortem pH (pH0) had no effect on the muscle nanostructure and tenderness while ultimate pH (pH24) affected MYD and MYS only. Muscle temperature at 45mins affected (P<0.05) the MYD, MFD and MFS, while 24hrs muscle temperature affected (P<0.05) MYD only. Tenderness was not related to the muscle nanostructure early post-mortem and there was no uniformity on the changes in muscle nanostructure and tenderness from early post-mortem to 24hrs against the multifaceted carcass mass, muscle pH and temperature effects. During ageing, breed affected the MYD and MYS at 45mins, while at 24hrs in addition to the myofibril structure breed also had an effect on muscle fibre bundle characteristics (MFD and MFS). The changes in MYD, MYS and MFS became constant on day 3 while variations in the MFD still progressed. There was no uniformity on the SL pattern during ageing and a very weak linear relationship between tenderness, SL, MFD and MFS was observed. Notably there was also no uniformity on how the muscle texture features; including the surface structure, fibre separation, and the mechanism of muscle contraction and relaxation; changed throughout the ageing period across and within the breeds. Moreover, breed had a significant effect on pentadecyclic acid, total saturated fatty acids (SFA) and docosahexanoic acid. Differences (P<0.05) in SFA, monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), n-6, n-3, fatty acid ratios, and desaturase index were observed among the white, creamy-white and creamy fat colour. The distribution of fatty acid classes was SFA>MUFA>PUFA in descending order of concentrations of mean values (44.19:40.06:15.75, respectively), while the n-6: n-3 ratio was 12:1. In sensory evaluation, consumers indicated how they would prefer to pay premium for meat with guaranteed muscle and fat colour, low fat content, high marbling and tenderness. Consumers observed breed differences (P<0.05) in muscle fibre separation and muscle colour. The overall liking of each attribute was more on moderate bright cherry red lean colour, moderate yellow fat, very abundant marbling and slight separation of muscle fibres. Differences on discrete liking of each attribute among consumers had an effect on the overall liking of each steak with Hereford steaks being more preferred by consumers. It was concluded that meat from beef animals within the same feeding regime has a different fatty acid composition owing to different breed synthetic pathways and feed ingredients and that meat tenderness is not affected by the muscle nanostructure early post-mortem. However, during ageing, meat tenderness is directly linked to breed related myofibril structure changes in particular the myofibril diameter, spacing between myofibrils and their interaction; while the muscle texture features, fibre diameter, spacing between muscle fibres and sarcomere length explain the non-uniformity of beef tenderness. Also the organoleptic and health related quality of meat assumed more importance among consumers in sensory evaluation. Thus meat classification systems should include more credence aspects or indicators that support credence quality of meat
- Full Text:
- Date Issued: 2019
Nonlinear optical responses of targeted phthalocyanines when conjugated with nanomaterials or fabricated into polymer thin films
- Authors: Nwaji, Njemuwa Njoku
- Date: 2019
- Subjects: Electrochemistry , Phthalocyanines , Nanoparticles , Bioconjugates , Thin films , Polymers , Nonlinear optics , Nonlinear optical spectroscopy , Nanostructured materials , Raman effect
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/71625 , vital:29926
- Description: A number of zinc, gallium and indium metallophthalocyanines (MPcs) with diverse substituents have been synthesized and characterized using various characterization tools such as proton nuclear magnetic resonance (1HNMR), matrix assisted laser desorption time of flight (MALDI-TOF) mass spectrometry, Fourier-transformed infra-red (FT-IR), Ultraviolet-visible (Uv-vis) spectrophotometry, magnetic circular dichroism and CHNS elemental analysis. The time dependent density functional theory was employed to probe the origin of spectroscopic information in these complexes. Complexes with gallium and indium as central metal showed higher triplet quantum yield compared to the zinc derivatives. Some of the MPcs were covalently linked to nanomaterials such as CdTe, CdTeSe, CdTeSe/ZnO, graphene quantum dots (GQDs) as well as metallic gold (AuNPs) and silver (AgNPs) nanoparticles. Others were either surface assembled onto AuNPs and AgNPs or embedded into polystyrene as polymer source. The phthalocyanine-nanomaterial composites (Pc-NMCs) were characterized with FT-IR, UV-visible spectrophotometry, transmission electron microscopy (TEM), dynamic light scattering (DLS), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and X-ray diffractometry (XRD). The thickness of the thin films was determined by utilization of the knife edge attachment of the A Bruker D8 Discover X-ray diffraction. The optical limiting properties (using the open-aperture Z-scan technique) of the MPcs and the Pc-NMCs were investigated. The investigated MPcs complexes generally showed good optical limiting properties. The nonlinear optical response of the MPcs were improved in the presence of nanomaterials such as the semiconductor quantum dots (SQDs), graphene quantum dots (GQDs) as well as metallic AuNPs and AgNPs with MPc-QDs showing the best optical limiting behavior. The optical limiting properties of the MPcs were greatly enhanced in the presence of polymer thin films.
- Full Text:
- Date Issued: 2019
- Authors: Nwaji, Njemuwa Njoku
- Date: 2019
- Subjects: Electrochemistry , Phthalocyanines , Nanoparticles , Bioconjugates , Thin films , Polymers , Nonlinear optics , Nonlinear optical spectroscopy , Nanostructured materials , Raman effect
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/71625 , vital:29926
- Description: A number of zinc, gallium and indium metallophthalocyanines (MPcs) with diverse substituents have been synthesized and characterized using various characterization tools such as proton nuclear magnetic resonance (1HNMR), matrix assisted laser desorption time of flight (MALDI-TOF) mass spectrometry, Fourier-transformed infra-red (FT-IR), Ultraviolet-visible (Uv-vis) spectrophotometry, magnetic circular dichroism and CHNS elemental analysis. The time dependent density functional theory was employed to probe the origin of spectroscopic information in these complexes. Complexes with gallium and indium as central metal showed higher triplet quantum yield compared to the zinc derivatives. Some of the MPcs were covalently linked to nanomaterials such as CdTe, CdTeSe, CdTeSe/ZnO, graphene quantum dots (GQDs) as well as metallic gold (AuNPs) and silver (AgNPs) nanoparticles. Others were either surface assembled onto AuNPs and AgNPs or embedded into polystyrene as polymer source. The phthalocyanine-nanomaterial composites (Pc-NMCs) were characterized with FT-IR, UV-visible spectrophotometry, transmission electron microscopy (TEM), dynamic light scattering (DLS), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and X-ray diffractometry (XRD). The thickness of the thin films was determined by utilization of the knife edge attachment of the A Bruker D8 Discover X-ray diffraction. The optical limiting properties (using the open-aperture Z-scan technique) of the MPcs and the Pc-NMCs were investigated. The investigated MPcs complexes generally showed good optical limiting properties. The nonlinear optical response of the MPcs were improved in the presence of nanomaterials such as the semiconductor quantum dots (SQDs), graphene quantum dots (GQDs) as well as metallic AuNPs and AgNPs with MPc-QDs showing the best optical limiting behavior. The optical limiting properties of the MPcs were greatly enhanced in the presence of polymer thin films.
- Full Text:
- Date Issued: 2019
Nutritional quality of sausage made with edible meat waste and the perception of consumers on offal product in Eastern Cape Province, South Africa
- Authors: Oluwasegun, Babatunde Alao
- Date: 2019
- Subjects: Meat -- Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/19021 , vital:40094
- Description: Meat processing at the abattoir provides meat by product and waste while, the major part of the muscle which constitutes a third is edible. The edible by products (EBP) of meat have a notable position in our day-to-day life and are used in diverse forms. However, the quality of offal meat may differ according to intrinsic and extrinsic attributes that may occasionally be shaped by the attitude of consumers towards the products. Therefore, the first objective of this thesis focused on features that might influence consumer preferences and their perception of offal meat. A total of 202 consumers from three Municipalities in Amathole District were randomly sampled using exponential nondiscriminative snowball sampling. Data were gathered through a structured questionnaire containing open ended and closed ended questions. The study showed that consumers were more influenced by the freshness, price and availability of the product and these factors are used to determine the purchase outlet. Differences were observed in the offal meat consumption between the age groups. Age groups 25-34 (29.7%) and 35-44 (27.4%) showed the highest offal meat consumption, while the decline was observed in age groups of 55-64 (11.9%), 65- 74 (5.9%) and 75-85 (0.01%) respectively. The most preferred purchase point for offal meat in this study was in butcheries. However, it was observed that the factors influencing offal consumption in Amathole District were similar to meat consumption except that, offals were mainly purchased at butcher shops. The second objective in this study was to determine the sensory characteristics and consumer acceptance of sausages with 10% fat, 30% edible meat waste and 50% edible meat waste. Sensory descriptive attributes such as appearance, texture, colour, taste, flavour and overall acceptance of the sausage were evaluated by sensory panel (n = 60). The sensory panel comprised of students from undergraduates, post-graduates, post-doctoral fellows and lecturers at the University of Fort Hare. The findings of the study indicated that 50% replacement of xiii edible meat waste was similar to the commercial 10% fat with regard to several sensory attributes and pooled liking. Therefore, the utilization of the edible meat waste in production of sausages has the potential to increase profitability in meat industry and minimise meat waste in the industry. However, the cooking method that was more acceptable to consumers in this study was using the microwave as compared to oven-grilling. Furthermore, the effects of different cooking methods (microwave and oven-grilling) on proximate and mineral composition of the formulated sausages were determined. However, the cooking process appeared to have a significant effect on most of the minerals in the sausage. The cooking methods had a significant effect at P <0.01 on the nutrients composition of the formulated sausage. It was observed that the nutritional values of the sausage was better preserved after the cooking process due to higher mean values obtained after cooking. The mean values for calcium (173.1, 221.76, 231.29), potassium (444.57, 158.58, 156.67), magnesium (84.43, 257.97, 127.27), zinc (52.94, 35.27, 27.13), copper (8.8, 7.07, 4.44), manganese (8.74, 0.65, 0.08), sodium (589.42, 604.45, 529.79) and iron (63.3, 85.38, 74.81) in cooked. And the mean values for calcium (286.18, 132.18, 114.79), potassium (206.64, 113.83, 207.81), magnesium (189.89, 33.97, 48.11), zinc (61.05, 28.09, 26.44), copper (2.92, 2.73, 3.89), manganese (1.42, 0.11, 0.35), sodium (566.47, 530.79, 527.35) and iron (77.56, 58.68, 45.42) in uncooked sausage varied greatly among the treatments. Although, the disparities in the mineral content may be attributed to the different edible meat waste from different parts of the cattle which are either from feedlot or pastured based. In regard to the results obtained from proximate and mineral composition, microwave cooking method was found to be the best cooking technique for healthy eating. Finally, the effect of frying with two different oils (sunflower oil and olive oil) on the fatty acid composition of sausage made with edible meat waste was examined. The results revealed that beef sausage containing 70% edible meat wastes and 30% beef (T1) had a higher fat content xiv (25.7%±0.83%) than other treatments. On the other hand, beef sausage fortified with 10% fat and 90% beef (T3) had the lowest fat content but highest FFDM (55.85±0.57%) and moisture content (69.15±0.62) than other treatments. Despite the increase in omega-3: omega-6 fatty acid ratio in the sausage treatments after cooking, the mean value of omega-3: omega-6 fatty acid ratio was greater than 1:5 (0.2) which is within the FAO/WHO recommended range. The omega-3: omega-6 association is well-known for its importance in the diet because it is a key factor for balanced eicosanoid production in the living organism. The significant reduction in saturated fatty acids after cooking showed that there could also be a positive influence on the human health if consumed. Therefore, it may be concluded from the findings of the study that sausage made with edible meat waste as fat replacer is safe for human consumption.
- Full Text:
- Date Issued: 2019
- Authors: Oluwasegun, Babatunde Alao
- Date: 2019
- Subjects: Meat -- Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/19021 , vital:40094
- Description: Meat processing at the abattoir provides meat by product and waste while, the major part of the muscle which constitutes a third is edible. The edible by products (EBP) of meat have a notable position in our day-to-day life and are used in diverse forms. However, the quality of offal meat may differ according to intrinsic and extrinsic attributes that may occasionally be shaped by the attitude of consumers towards the products. Therefore, the first objective of this thesis focused on features that might influence consumer preferences and their perception of offal meat. A total of 202 consumers from three Municipalities in Amathole District were randomly sampled using exponential nondiscriminative snowball sampling. Data were gathered through a structured questionnaire containing open ended and closed ended questions. The study showed that consumers were more influenced by the freshness, price and availability of the product and these factors are used to determine the purchase outlet. Differences were observed in the offal meat consumption between the age groups. Age groups 25-34 (29.7%) and 35-44 (27.4%) showed the highest offal meat consumption, while the decline was observed in age groups of 55-64 (11.9%), 65- 74 (5.9%) and 75-85 (0.01%) respectively. The most preferred purchase point for offal meat in this study was in butcheries. However, it was observed that the factors influencing offal consumption in Amathole District were similar to meat consumption except that, offals were mainly purchased at butcher shops. The second objective in this study was to determine the sensory characteristics and consumer acceptance of sausages with 10% fat, 30% edible meat waste and 50% edible meat waste. Sensory descriptive attributes such as appearance, texture, colour, taste, flavour and overall acceptance of the sausage were evaluated by sensory panel (n = 60). The sensory panel comprised of students from undergraduates, post-graduates, post-doctoral fellows and lecturers at the University of Fort Hare. The findings of the study indicated that 50% replacement of xiii edible meat waste was similar to the commercial 10% fat with regard to several sensory attributes and pooled liking. Therefore, the utilization of the edible meat waste in production of sausages has the potential to increase profitability in meat industry and minimise meat waste in the industry. However, the cooking method that was more acceptable to consumers in this study was using the microwave as compared to oven-grilling. Furthermore, the effects of different cooking methods (microwave and oven-grilling) on proximate and mineral composition of the formulated sausages were determined. However, the cooking process appeared to have a significant effect on most of the minerals in the sausage. The cooking methods had a significant effect at P <0.01 on the nutrients composition of the formulated sausage. It was observed that the nutritional values of the sausage was better preserved after the cooking process due to higher mean values obtained after cooking. The mean values for calcium (173.1, 221.76, 231.29), potassium (444.57, 158.58, 156.67), magnesium (84.43, 257.97, 127.27), zinc (52.94, 35.27, 27.13), copper (8.8, 7.07, 4.44), manganese (8.74, 0.65, 0.08), sodium (589.42, 604.45, 529.79) and iron (63.3, 85.38, 74.81) in cooked. And the mean values for calcium (286.18, 132.18, 114.79), potassium (206.64, 113.83, 207.81), magnesium (189.89, 33.97, 48.11), zinc (61.05, 28.09, 26.44), copper (2.92, 2.73, 3.89), manganese (1.42, 0.11, 0.35), sodium (566.47, 530.79, 527.35) and iron (77.56, 58.68, 45.42) in uncooked sausage varied greatly among the treatments. Although, the disparities in the mineral content may be attributed to the different edible meat waste from different parts of the cattle which are either from feedlot or pastured based. In regard to the results obtained from proximate and mineral composition, microwave cooking method was found to be the best cooking technique for healthy eating. Finally, the effect of frying with two different oils (sunflower oil and olive oil) on the fatty acid composition of sausage made with edible meat waste was examined. The results revealed that beef sausage containing 70% edible meat wastes and 30% beef (T1) had a higher fat content xiv (25.7%±0.83%) than other treatments. On the other hand, beef sausage fortified with 10% fat and 90% beef (T3) had the lowest fat content but highest FFDM (55.85±0.57%) and moisture content (69.15±0.62) than other treatments. Despite the increase in omega-3: omega-6 fatty acid ratio in the sausage treatments after cooking, the mean value of omega-3: omega-6 fatty acid ratio was greater than 1:5 (0.2) which is within the FAO/WHO recommended range. The omega-3: omega-6 association is well-known for its importance in the diet because it is a key factor for balanced eicosanoid production in the living organism. The significant reduction in saturated fatty acids after cooking showed that there could also be a positive influence on the human health if consumed. Therefore, it may be concluded from the findings of the study that sausage made with edible meat waste as fat replacer is safe for human consumption.
- Full Text:
- Date Issued: 2019
Observing cosmic reionization with PAPER: polarized foreground simulations and all sky images
- Authors: Nunhokee, Chuneeta Devi
- Date: 2019
- Subjects: Cosmic background radiation , Astronomy -- Observations , Epoch of reionization -- Research , Hydrogen -- Spectra , Radio interferometers
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/68203 , vital:29218
- Description: The Donald C. Backer Precision Array to Probe the Epoch of Reionization (PAPER, Parsons et al., 2010) was built with an aim to detect the redshifted 21 cm Hydrogen line, which is likely the best probe of thermal evolution of the intergalactic medium and reionization of neutral Hydrogen in our Universe. Observations of the 21 cm signal are challenged by bright astrophysical foregrounds and systematics that require precise modeling in order to extract the cosmological signal. In particular, the instrumental leakage of polarized foregrounds may contaminate the 21 cm power spectrum. In this work, we developed a formalism to describe the leakage due to instrumental widefield effects in visibility-based power spectra and used it to predict contaminations in observations. We find the leakage due to a population of point sources to be higher than the diffuse Galactic emission – for which we can predict minimal contaminations at k>0.3 h Mpc -¹ We also analyzed data from the last observing season of PAPER via all-sky imaging with a view to characterize the foregrounds. We generated an all-sky catalogue of 88 sources down to a flux density of 5 Jy. Moreover, we measured both polarized point source and the Galactic diffuse emission, and used these measurements to constrain our model of polarization leakage. We find the leakage due to a population of point sources to be 12% lower than the prediction from our polarized model.
- Full Text:
- Date Issued: 2019
- Authors: Nunhokee, Chuneeta Devi
- Date: 2019
- Subjects: Cosmic background radiation , Astronomy -- Observations , Epoch of reionization -- Research , Hydrogen -- Spectra , Radio interferometers
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/68203 , vital:29218
- Description: The Donald C. Backer Precision Array to Probe the Epoch of Reionization (PAPER, Parsons et al., 2010) was built with an aim to detect the redshifted 21 cm Hydrogen line, which is likely the best probe of thermal evolution of the intergalactic medium and reionization of neutral Hydrogen in our Universe. Observations of the 21 cm signal are challenged by bright astrophysical foregrounds and systematics that require precise modeling in order to extract the cosmological signal. In particular, the instrumental leakage of polarized foregrounds may contaminate the 21 cm power spectrum. In this work, we developed a formalism to describe the leakage due to instrumental widefield effects in visibility-based power spectra and used it to predict contaminations in observations. We find the leakage due to a population of point sources to be higher than the diffuse Galactic emission – for which we can predict minimal contaminations at k>0.3 h Mpc -¹ We also analyzed data from the last observing season of PAPER via all-sky imaging with a view to characterize the foregrounds. We generated an all-sky catalogue of 88 sources down to a flux density of 5 Jy. Moreover, we measured both polarized point source and the Galactic diffuse emission, and used these measurements to constrain our model of polarization leakage. We find the leakage due to a population of point sources to be 12% lower than the prediction from our polarized model.
- Full Text:
- Date Issued: 2019
Occurrence, feeding ecology, and population structure of two dolphin species, Tursiops aduncus and Delphinus delphis, off the Wild Coast of South Africa
- Authors: Caputo, Michelle Anne
- Date: 2019
- Subjects: Delphinus -- South Africa-- Kwazulu-Natal -- Ecology , Tursoops -- South Africa-- Kwazulu-Natal -- Ecology , Delphinus -- South Africa-- Kwazulu-Natal -- Feeding and feeds , Tursoops -- South Africa-- Kwazulu-Natal -- Feeding and feeds , Dolphins -- South Africa-- Kwazulu-Natal , Delphinus -- South Africa-- Kwazulu-Natal -- Behavior , Tursoops -- South Africa-- Kwazulu-Natal -- Behavior , Marine ecology -- South Africa -- Kwazulu-Natal
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115612 , vital:34197
- Description: Dolphins are apex predators and their movements, foraging activities and population dynamics play an important role in shaping their environment. Understanding their occurrence, movement patterns, and trophic ecology is essential to their conservation, especially as they are considered sentinel species. The Wild Coast of South Africa’s Eastern Cape, is characterized by the annual sardine (Sardinops sagax) run, which serves as an important foraging event for apex predators, including Indo-Pacific bottlenose (Tursiops aduncus) and long-beaked common dolphins (Delphinus delphis). Despite the ecological significance of this event, no dedicated surveys for these species have previously been conducted in this area. The main objectives of this research were to: investigate long-term occurrence of dolphins during the sardine run to determine if there have been any changes over the past 19 years, as has been predicted from common dolphin dietary investigations and anecdotal evidence; to determine short-term occurrence and movement patterns of selected inshore delphinids within the area, which is characterized by three marine protected areas (MPAs); and to use stable isotope analyses to determine trophic relationships and population structure of bottlenose and common dolphins within the region. Long-term data consisted of 131 opportunistic aerial surveys conducted between May and July over the period 1996 to 2014. Results from these surveys indicate that common dolphins, typically associated with sardines, decreased significantly in average group size over the study period (p=0.0343). Bottlenose dolphins, demonstrated no such trend (p=0.916). For both species, greater majority (> 70% of total counts) of sightings were made inside the MPAs. Short-term boat-based surveys were conducted three times a year between June 2014 and December 2016, contributing to a total of 47 days of surveys divided into three locations: Amathole, Hluleka, and Pondoland, each containing a MPA. Density and group size data were analyzed for both species and photographic identification analysis was performed for photographs of bottlenose dolphin dorsal fins. Results indicate that animal and sighting density did not differ temporally (bottlenose dolphin: sighting density – p=0.398, individual density –p=0.781; common dolphin: sighting density –p=0.472, individual density – p=0.204). Environmental factors (sea surface temperature, depth, substrate, and distance from shore) appeared to have limited effect on individual and sighting density and group size for both species (p>0.05). Photographic identification of bottlenose dolphins resulted in 2149 individuals, with a 11.8% resighting rate, with the highest resighting rate within the Pondoland MPA (16.1%). The resighting count did not differ temporally between monthly survey based on generalized linear models (p=0.866), but did differ between study areas (p<0.0001). These results provide the first evidence of the occurrence of both species of dolphin off the Wild Coast, as they were sighted in this region in all survey months. There was no trend in density based on temporal or environmental factors, which suggests other factors are influencing their occurrence. Resightings of bottlenose dolphins within the area suggest that there is some degree of residency, though the majority of animals were only sighted on a single occasion and there was no plateau in the discovery curve. A total of 256 biopsy samples (bottlenose dolphins =128; common dolphins=128) were collected during boat-based surveys. Bottlenose dolphin samples were also collected from adjacent areas to the southwest (Algoa Bay, n=22) and northeast (KwaZulu-Natal (KZN), n=20) of the Wild Coast to investigate similarities and differences between these areas. Despite a high degree of niche overlap between the two species (41%), common dolphins fed with a broader niche (standard ellipse area probability 0.89) than bottlenose dolphins in the summer and a narrower niche in the winter (probability 0.94). There was a clear spatial variation in the diet of bottlenose dolphins along the coast, with individuals from Algoa Bay and Amathole demonstrating 0% niche overlap with individuals from KZN, but the mechanism for these differences remains unclear as other species from South African waters demonstrate a strong southwest to northeast gradient in nitrogen for the Eastern Cape coastline. This research provides valuable baseline information regarding dolphins off the Wild Coast of South Africa, which remained largely unknown. My results indicate that bottlenose dolphins may be more resident in the Wild Coast than previous predicted, and confirm that common dolphins are highly mobile in this area.
- Full Text:
- Date Issued: 2019
- Authors: Caputo, Michelle Anne
- Date: 2019
- Subjects: Delphinus -- South Africa-- Kwazulu-Natal -- Ecology , Tursoops -- South Africa-- Kwazulu-Natal -- Ecology , Delphinus -- South Africa-- Kwazulu-Natal -- Feeding and feeds , Tursoops -- South Africa-- Kwazulu-Natal -- Feeding and feeds , Dolphins -- South Africa-- Kwazulu-Natal , Delphinus -- South Africa-- Kwazulu-Natal -- Behavior , Tursoops -- South Africa-- Kwazulu-Natal -- Behavior , Marine ecology -- South Africa -- Kwazulu-Natal
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115612 , vital:34197
- Description: Dolphins are apex predators and their movements, foraging activities and population dynamics play an important role in shaping their environment. Understanding their occurrence, movement patterns, and trophic ecology is essential to their conservation, especially as they are considered sentinel species. The Wild Coast of South Africa’s Eastern Cape, is characterized by the annual sardine (Sardinops sagax) run, which serves as an important foraging event for apex predators, including Indo-Pacific bottlenose (Tursiops aduncus) and long-beaked common dolphins (Delphinus delphis). Despite the ecological significance of this event, no dedicated surveys for these species have previously been conducted in this area. The main objectives of this research were to: investigate long-term occurrence of dolphins during the sardine run to determine if there have been any changes over the past 19 years, as has been predicted from common dolphin dietary investigations and anecdotal evidence; to determine short-term occurrence and movement patterns of selected inshore delphinids within the area, which is characterized by three marine protected areas (MPAs); and to use stable isotope analyses to determine trophic relationships and population structure of bottlenose and common dolphins within the region. Long-term data consisted of 131 opportunistic aerial surveys conducted between May and July over the period 1996 to 2014. Results from these surveys indicate that common dolphins, typically associated with sardines, decreased significantly in average group size over the study period (p=0.0343). Bottlenose dolphins, demonstrated no such trend (p=0.916). For both species, greater majority (> 70% of total counts) of sightings were made inside the MPAs. Short-term boat-based surveys were conducted three times a year between June 2014 and December 2016, contributing to a total of 47 days of surveys divided into three locations: Amathole, Hluleka, and Pondoland, each containing a MPA. Density and group size data were analyzed for both species and photographic identification analysis was performed for photographs of bottlenose dolphin dorsal fins. Results indicate that animal and sighting density did not differ temporally (bottlenose dolphin: sighting density – p=0.398, individual density –p=0.781; common dolphin: sighting density –p=0.472, individual density – p=0.204). Environmental factors (sea surface temperature, depth, substrate, and distance from shore) appeared to have limited effect on individual and sighting density and group size for both species (p>0.05). Photographic identification of bottlenose dolphins resulted in 2149 individuals, with a 11.8% resighting rate, with the highest resighting rate within the Pondoland MPA (16.1%). The resighting count did not differ temporally between monthly survey based on generalized linear models (p=0.866), but did differ between study areas (p<0.0001). These results provide the first evidence of the occurrence of both species of dolphin off the Wild Coast, as they were sighted in this region in all survey months. There was no trend in density based on temporal or environmental factors, which suggests other factors are influencing their occurrence. Resightings of bottlenose dolphins within the area suggest that there is some degree of residency, though the majority of animals were only sighted on a single occasion and there was no plateau in the discovery curve. A total of 256 biopsy samples (bottlenose dolphins =128; common dolphins=128) were collected during boat-based surveys. Bottlenose dolphin samples were also collected from adjacent areas to the southwest (Algoa Bay, n=22) and northeast (KwaZulu-Natal (KZN), n=20) of the Wild Coast to investigate similarities and differences between these areas. Despite a high degree of niche overlap between the two species (41%), common dolphins fed with a broader niche (standard ellipse area probability 0.89) than bottlenose dolphins in the summer and a narrower niche in the winter (probability 0.94). There was a clear spatial variation in the diet of bottlenose dolphins along the coast, with individuals from Algoa Bay and Amathole demonstrating 0% niche overlap with individuals from KZN, but the mechanism for these differences remains unclear as other species from South African waters demonstrate a strong southwest to northeast gradient in nitrogen for the Eastern Cape coastline. This research provides valuable baseline information regarding dolphins off the Wild Coast of South Africa, which remained largely unknown. My results indicate that bottlenose dolphins may be more resident in the Wild Coast than previous predicted, and confirm that common dolphins are highly mobile in this area.
- Full Text:
- Date Issued: 2019
Ontological Model for Xhosa Beadwork in Marginalised Rural Communities: A Case of the Eastern Cape
- Authors: Tinarwo, Loyd
- Date: 2019
- Subjects: Ontology Beadwork
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15749 , vital:40516
- Description: In South Africa, computational ontologies have gained traction and are increasingly viewed as one of the viable solutions to address the problem of fragmented and unstructured nature of indigenous knowledge (IK) particularly in the marginalized rural communities. The continual existence of IK in tacit form has impeded the use of IK as a potential resource that can catalyze socio-economic and cultural development in South Africa. This study was, therefore, designed to address part of this challenge by developing a Xhosa Beadwork Ontology (XBO) with the goal of structuring the domain knowledge into a reusable body of knowledge. Such a reusable body of knowledge promotes efficient sharing of a common understanding of Xhosa Beadwork in a computational form. The XBO is in OWL 2 DL. The development of the XBO was informed by the NeOn methodology and the iterativeincremental ontology development life cycle within the ambit of Action Research (AR). The XBO was developed around personal ornamentation Xhosa Beadwork consisting of Necklace, Headband, Armlet, Waistband, Bracelet, and Anklet. In this study, the XBO was evaluated focused on ascertaining that the created ontology is a comprehensive representation of the Xhosa Beadwork and is of the required standard. In addition, the XBO was documented into a human understandable and readable resource and was published. The outcome of the study has indicated that the XBO is an adequate, shareable and reusable semantic artifact that can indeed support the formalization and preservation of IK in the domain of Xhosa Beadwork
- Full Text:
- Date Issued: 2019
- Authors: Tinarwo, Loyd
- Date: 2019
- Subjects: Ontology Beadwork
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15749 , vital:40516
- Description: In South Africa, computational ontologies have gained traction and are increasingly viewed as one of the viable solutions to address the problem of fragmented and unstructured nature of indigenous knowledge (IK) particularly in the marginalized rural communities. The continual existence of IK in tacit form has impeded the use of IK as a potential resource that can catalyze socio-economic and cultural development in South Africa. This study was, therefore, designed to address part of this challenge by developing a Xhosa Beadwork Ontology (XBO) with the goal of structuring the domain knowledge into a reusable body of knowledge. Such a reusable body of knowledge promotes efficient sharing of a common understanding of Xhosa Beadwork in a computational form. The XBO is in OWL 2 DL. The development of the XBO was informed by the NeOn methodology and the iterativeincremental ontology development life cycle within the ambit of Action Research (AR). The XBO was developed around personal ornamentation Xhosa Beadwork consisting of Necklace, Headband, Armlet, Waistband, Bracelet, and Anklet. In this study, the XBO was evaluated focused on ascertaining that the created ontology is a comprehensive representation of the Xhosa Beadwork and is of the required standard. In addition, the XBO was documented into a human understandable and readable resource and was published. The outcome of the study has indicated that the XBO is an adequate, shareable and reusable semantic artifact that can indeed support the formalization and preservation of IK in the domain of Xhosa Beadwork
- Full Text:
- Date Issued: 2019
Optimising construction project role-player performance
- Authors: Hefer, Andre Le Roux
- Date: 2019
- Subjects: Construction industry -- Management , Project management Performance
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/40316 , vital:36140
- Description: Authors predict major changes in the requirements to manage complex environments in the 21st century. These 21st century challenges, for Project Managers (PM) in the construction industry, are evident through the ongoing perception that the industry performance record is suboptimal. In the pursuit of performance optimisation, management disciplines developed and implemented theories and models not only to achieve what is required, but also to excel and create high-performing teams. In search of project success, researchers have also identified quantifiable variables, models, success factors and other related issues. The PM’s role in the attainment of success has also been widely researched, especially the impact, influence, methods and tools related to the discipline. Nevertheless, the general concern remains, that the performance of the industry is suboptimal. This study therefore aimed to qualitatively evaluate and examine the various factors and influences on performance of a construction project team. This research applies to the motivation and environmental factors influencing project teams in the achievement of optimum performance; and in doing so, to enhance the performance of project-role players; while adding disciplinespecific theory. This study has employed in-depth interview data, which were thematically analysed. The interviews were conducted in a case-study design comprising four projects in South Africa. The study concluded by emphasising the importance of how role-players RELATE to each other, and LOVE project challenges. It further noted that PMs who are MANAGING LEADERS would be most influential in the project environment; while PROCUREMENT greatly influences the project environment. Relational issues are important to role-players; and they act as MOTIVATORS, with certain issues in a project presenting both performance BARRIERS and DRIVER capabilities. Finally, project MOMENTUM changes constantly, with the current momentum direction influencing the future course thereof. In meeting the aims of the research, a Performance Optimisation Framework was developed, noting how the emergent themes co-exist in optimal performance environments. The study also developed the Project Husbandry approach, reflecting on a caring, nurturing, diligent and mature approach when managing role-players. The study recommends that the themes impacting the project-operating environment should be influenced by management and leadership, in order to optimise the performance of all the role-players involved.
- Full Text:
- Date Issued: 2019
- Authors: Hefer, Andre Le Roux
- Date: 2019
- Subjects: Construction industry -- Management , Project management Performance
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/40316 , vital:36140
- Description: Authors predict major changes in the requirements to manage complex environments in the 21st century. These 21st century challenges, for Project Managers (PM) in the construction industry, are evident through the ongoing perception that the industry performance record is suboptimal. In the pursuit of performance optimisation, management disciplines developed and implemented theories and models not only to achieve what is required, but also to excel and create high-performing teams. In search of project success, researchers have also identified quantifiable variables, models, success factors and other related issues. The PM’s role in the attainment of success has also been widely researched, especially the impact, influence, methods and tools related to the discipline. Nevertheless, the general concern remains, that the performance of the industry is suboptimal. This study therefore aimed to qualitatively evaluate and examine the various factors and influences on performance of a construction project team. This research applies to the motivation and environmental factors influencing project teams in the achievement of optimum performance; and in doing so, to enhance the performance of project-role players; while adding disciplinespecific theory. This study has employed in-depth interview data, which were thematically analysed. The interviews were conducted in a case-study design comprising four projects in South Africa. The study concluded by emphasising the importance of how role-players RELATE to each other, and LOVE project challenges. It further noted that PMs who are MANAGING LEADERS would be most influential in the project environment; while PROCUREMENT greatly influences the project environment. Relational issues are important to role-players; and they act as MOTIVATORS, with certain issues in a project presenting both performance BARRIERS and DRIVER capabilities. Finally, project MOMENTUM changes constantly, with the current momentum direction influencing the future course thereof. In meeting the aims of the research, a Performance Optimisation Framework was developed, noting how the emergent themes co-exist in optimal performance environments. The study also developed the Project Husbandry approach, reflecting on a caring, nurturing, diligent and mature approach when managing role-players. The study recommends that the themes impacting the project-operating environment should be influenced by management and leadership, in order to optimise the performance of all the role-players involved.
- Full Text:
- Date Issued: 2019
Oral narratives as intertexts in selected Nigerian films
- Authors: Usman, Joshua
- Date: 2019
- Subjects: Folk literature -- Nigeria , Oral tradition -- Nigeria Motion pictures -- Nigeria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/43721 , vital:37038
- Description: This research into the interface between orality and Nigerian film builds on previous scholarly works in the field (Ladebo (1992), Onabajo and M’Bayo (2009), Omolola (2013), Ezeigbo (2013), Mgbemere (2015) and Onzuike (2016)). Evident from these studies is the prevalence of recurring patterns of oral narratives in Nigerian film. The aim of this study is to consider the following research questions: Do film producers/directors adopt the use of oral narratives in Nigerian film texts? How do oral narratives translate into films? What is the rate of recurrence of oral narratives in Nigerian films? Do oral narratives aesthetically influence the quality of Nigerian films? For the purpose of this study a selection of nine Nigerian films (three each from the Yoruba, Hausa and Igbo groups). These films are analysed as primary texts to show the occurrence of elements of orature and oral narratives. Underpinning such analysis is the theory of intertextuality as coined by the French linguist Julia Kristeva. Kristeva sees the text as “intertextuality […] within the text of society and history” (Kristeva, 1980: 37). This approach is augmented by the views of Greenblatt on New Historicism, which implies literature should be studied and interpreted within the context of the history of the author and cultural/social context. The nine films under discussion are considered within their cultural/social context.
- Full Text:
- Date Issued: 2019
- Authors: Usman, Joshua
- Date: 2019
- Subjects: Folk literature -- Nigeria , Oral tradition -- Nigeria Motion pictures -- Nigeria
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/43721 , vital:37038
- Description: This research into the interface between orality and Nigerian film builds on previous scholarly works in the field (Ladebo (1992), Onabajo and M’Bayo (2009), Omolola (2013), Ezeigbo (2013), Mgbemere (2015) and Onzuike (2016)). Evident from these studies is the prevalence of recurring patterns of oral narratives in Nigerian film. The aim of this study is to consider the following research questions: Do film producers/directors adopt the use of oral narratives in Nigerian film texts? How do oral narratives translate into films? What is the rate of recurrence of oral narratives in Nigerian films? Do oral narratives aesthetically influence the quality of Nigerian films? For the purpose of this study a selection of nine Nigerian films (three each from the Yoruba, Hausa and Igbo groups). These films are analysed as primary texts to show the occurrence of elements of orature and oral narratives. Underpinning such analysis is the theory of intertextuality as coined by the French linguist Julia Kristeva. Kristeva sees the text as “intertextuality […] within the text of society and history” (Kristeva, 1980: 37). This approach is augmented by the views of Greenblatt on New Historicism, which implies literature should be studied and interpreted within the context of the history of the author and cultural/social context. The nine films under discussion are considered within their cultural/social context.
- Full Text:
- Date Issued: 2019
Patriarchy and the participation of women in Zimbabwean national politics: a study of selected women Politicians in Matabeleland Region
- Authors: Manyevere, Sithabile
- Date: 2019
- Subjects: Women politicians Women -- Political activity -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/17506 , vital:41082
- Description: The research sought to analyse how patriarchal perceptions have affected women in Zimbabwean national politics with specific focus on women politicians in Matabeleland region. The researcher observed that women politicians in this region seem to face multiple oppressions and yet seem to have been excluded in previous studies. The mixed method approach was adopted for the research. Questionnaires were used for the quantitative method, while key informant interviews and focus group discussions were utilised for the qualitative method. Findings from the survey revealed stereotypical perceptions such as that men are better leaders than women, women are not capable of holding decision making positions and the perception that politics is not safe for women. The findings from the key informants indicate that women politicians in Matabeleland face quite a number of challenges emanating from these patriarchal perceptions. The challenges include violence, humiliation and cultural stigmatization. Although women have attempted to resist patriarchy, it seems that the resistance has not been enough to eliminate the patriarchal mentality and the oppressions that accompany it. The research adopts a combination of feminist and intersectionality theory as a framework for analysis of the problem under investigation. The research potentially contributes to academic discourse by advancing literature on the multi-faceted aspects of patriarchy. The study recommends psychological and financial empowerment of women, electoral reforms and criminalization of offenders. The implementation of proper reforms and corrective measures envisage the long-awaited new dawn among women whom since time memorial, have been suppressed by deep-seated societal and patriarchal beliefs.
- Full Text:
- Date Issued: 2019
- Authors: Manyevere, Sithabile
- Date: 2019
- Subjects: Women politicians Women -- Political activity -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/17506 , vital:41082
- Description: The research sought to analyse how patriarchal perceptions have affected women in Zimbabwean national politics with specific focus on women politicians in Matabeleland region. The researcher observed that women politicians in this region seem to face multiple oppressions and yet seem to have been excluded in previous studies. The mixed method approach was adopted for the research. Questionnaires were used for the quantitative method, while key informant interviews and focus group discussions were utilised for the qualitative method. Findings from the survey revealed stereotypical perceptions such as that men are better leaders than women, women are not capable of holding decision making positions and the perception that politics is not safe for women. The findings from the key informants indicate that women politicians in Matabeleland face quite a number of challenges emanating from these patriarchal perceptions. The challenges include violence, humiliation and cultural stigmatization. Although women have attempted to resist patriarchy, it seems that the resistance has not been enough to eliminate the patriarchal mentality and the oppressions that accompany it. The research adopts a combination of feminist and intersectionality theory as a framework for analysis of the problem under investigation. The research potentially contributes to academic discourse by advancing literature on the multi-faceted aspects of patriarchy. The study recommends psychological and financial empowerment of women, electoral reforms and criminalization of offenders. The implementation of proper reforms and corrective measures envisage the long-awaited new dawn among women whom since time memorial, have been suppressed by deep-seated societal and patriarchal beliefs.
- Full Text:
- Date Issued: 2019
Perceptions on the efficacy of equine assisted play therapy™ in addressing low self-esteem of young bullied children
- Authors: Van Loggerenberg, Monique
- Date: 2019
- Subjects: Animals -- Therapeutic use , Play therapy Bullying Self-esteem -- South Africa Educational psychology -- South Africa
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: http://hdl.handle.net/10948/44179 , vital:37126
- Description: During the past decade, a surge of research emerged regarding the human-animal bond and how interactions with animals could be beneficial to both humans and animals on emotional, cognitive and biological levels. However, amongst others, a gap in literature on the experiences and perceptions of participants involved in animal assisted therapy programmes remain. This research focused on a specific population (bully victims presenting with low self-esteem in the middle childhood phase), also reflecting the perceptions of parties not directly involved in therapy, such as parents and teachers. This research adhered to strict ethical standards in accordance to NMU’s Ethical guidelines as well as in accordance to guidelines provided by the International Institute of Animal Assisted Play Therapy™. The welfare of both the horse and humans involved in this study was deemed equally important. Based upon the Gestalt therapy theory, the therapees were given the opportunity to explore alternatives, be creative and reveal specific therapeutic elements needing attention during each session. The focus was on building a therapeutic relationship in which the therapees could trust themselves, the therapist and horse to find the answers they needed and obtain the necessary skills to overcome feelings of helplessness when being bullied. Therapees presenting with low self-esteem results in specific vulnerability as it can be both the cause of being bullied or lead to being bullied. During the Equine Assisted Play Therapy™ (EAPT™) sessions the disempowered victim was allowed the opportunity to succeed in being assertive. Such children in therapy were given the opportunity to take centre-stage without being made fun of, whilst being encouraged to try out new behaviour and experience personal change. This study highlighted the perceptions of parents and teachers and the lived experiences of bully-victims. Exploring the efficacy of a relatively new therapeutic method, EAPT™ in addressing the low self-esteem levels and subsequent behaviour in the children who participated in this form of therapy, showed promising results in increasing self-esteem levels and positive behavioural changes in therapees.
- Full Text:
- Date Issued: 2019
- Authors: Van Loggerenberg, Monique
- Date: 2019
- Subjects: Animals -- Therapeutic use , Play therapy Bullying Self-esteem -- South Africa Educational psychology -- South Africa
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: http://hdl.handle.net/10948/44179 , vital:37126
- Description: During the past decade, a surge of research emerged regarding the human-animal bond and how interactions with animals could be beneficial to both humans and animals on emotional, cognitive and biological levels. However, amongst others, a gap in literature on the experiences and perceptions of participants involved in animal assisted therapy programmes remain. This research focused on a specific population (bully victims presenting with low self-esteem in the middle childhood phase), also reflecting the perceptions of parties not directly involved in therapy, such as parents and teachers. This research adhered to strict ethical standards in accordance to NMU’s Ethical guidelines as well as in accordance to guidelines provided by the International Institute of Animal Assisted Play Therapy™. The welfare of both the horse and humans involved in this study was deemed equally important. Based upon the Gestalt therapy theory, the therapees were given the opportunity to explore alternatives, be creative and reveal specific therapeutic elements needing attention during each session. The focus was on building a therapeutic relationship in which the therapees could trust themselves, the therapist and horse to find the answers they needed and obtain the necessary skills to overcome feelings of helplessness when being bullied. Therapees presenting with low self-esteem results in specific vulnerability as it can be both the cause of being bullied or lead to being bullied. During the Equine Assisted Play Therapy™ (EAPT™) sessions the disempowered victim was allowed the opportunity to succeed in being assertive. Such children in therapy were given the opportunity to take centre-stage without being made fun of, whilst being encouraged to try out new behaviour and experience personal change. This study highlighted the perceptions of parents and teachers and the lived experiences of bully-victims. Exploring the efficacy of a relatively new therapeutic method, EAPT™ in addressing the low self-esteem levels and subsequent behaviour in the children who participated in this form of therapy, showed promising results in increasing self-esteem levels and positive behavioural changes in therapees.
- Full Text:
- Date Issued: 2019
Personality and Psychological Conditions in Relation to Job Engagement among Municipal Workers in the Eastern Cape Province, South Africa
- Authors: Mhlanga, Tatenda Shaleen
- Date: 2019
- Subjects: Job stress -- South Africa -- Eastern Cape Municipal government -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , D.Com (Industrial Psychology)
- Identifier: http://hdl.handle.net/10353/13729 , vital:39702
- Description: The efficiency of the public service delivery depends on the performance of the public employees. Due to high protest in the Eastern Cape due to poor service delivery, it is crucial to understand if the employees are engaged in doing their work. Although researchers have discovered many of the beneficial and positive consequences of job engagement, little is known about the multitude of antecedent factors that lead to employee engagement such as personality. The motivation of this study is to examine the relationship between the big five personality traits (openness to experience, conscientiousness, extraversion, agreeableness and neuroticism) and job engagement (physical, cognitive and emotional engagement) among municipal employees working in the six district municipalities of the Eastern Cape Province of South Africa. The study also looked at psychological conditions (availability, meaningfulness and safety) as a moderating factor between personality and job engagement. This contributes to the theoretical and conceptual knowledge of how job engagement can be enhanced through the hiring employees with certain personality traits and enhancing meaningfulness, safety and availability of psychological resources in the workplace. Survey questionnaires were used to collect data. Inferential analysis from SPSS was carried out to understand the relationship between the study variables. An overall model of the study was also identified through which showed the relationship on the study variables. The study findings show that openness to experience, conscientiousness, extraversion, agreeableness had a positive relationship with job engagement while neuroticism has a negative relationship with job engagement. All psychological conditions had a positive correlation with job engagement and when combined with the big five personality traits they added more variance in job engagement. The results validate aspects of Kahn’s personal engagement model. v The study recommends managers to switch from an intervention-based focus to a selection-based focus as municipalities can maximize their resources by being able to better predict job success early in the selection process as opposed to trying to maximize performance on a continual basis through interventions. In addition, management practitioners should regularly measure and track employee engagement for the effectiveness of strategic efforts to increase employee engagement to be monitored and evaluated
- Full Text:
- Date Issued: 2019
- Authors: Mhlanga, Tatenda Shaleen
- Date: 2019
- Subjects: Job stress -- South Africa -- Eastern Cape Municipal government -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , D.Com (Industrial Psychology)
- Identifier: http://hdl.handle.net/10353/13729 , vital:39702
- Description: The efficiency of the public service delivery depends on the performance of the public employees. Due to high protest in the Eastern Cape due to poor service delivery, it is crucial to understand if the employees are engaged in doing their work. Although researchers have discovered many of the beneficial and positive consequences of job engagement, little is known about the multitude of antecedent factors that lead to employee engagement such as personality. The motivation of this study is to examine the relationship between the big five personality traits (openness to experience, conscientiousness, extraversion, agreeableness and neuroticism) and job engagement (physical, cognitive and emotional engagement) among municipal employees working in the six district municipalities of the Eastern Cape Province of South Africa. The study also looked at psychological conditions (availability, meaningfulness and safety) as a moderating factor between personality and job engagement. This contributes to the theoretical and conceptual knowledge of how job engagement can be enhanced through the hiring employees with certain personality traits and enhancing meaningfulness, safety and availability of psychological resources in the workplace. Survey questionnaires were used to collect data. Inferential analysis from SPSS was carried out to understand the relationship between the study variables. An overall model of the study was also identified through which showed the relationship on the study variables. The study findings show that openness to experience, conscientiousness, extraversion, agreeableness had a positive relationship with job engagement while neuroticism has a negative relationship with job engagement. All psychological conditions had a positive correlation with job engagement and when combined with the big five personality traits they added more variance in job engagement. The results validate aspects of Kahn’s personal engagement model. v The study recommends managers to switch from an intervention-based focus to a selection-based focus as municipalities can maximize their resources by being able to better predict job success early in the selection process as opposed to trying to maximize performance on a continual basis through interventions. In addition, management practitioners should regularly measure and track employee engagement for the effectiveness of strategic efforts to increase employee engagement to be monitored and evaluated
- Full Text:
- Date Issued: 2019
Personality in relation to work-family conflict among employees in a mining company in South Africa
- Authors: Ruzungunde, Vongai Sarah
- Date: 2019
- Subjects: Job stress Role conflict Work and family
- Language: English
- Type: Thesis , Doctoral , PhD (Industrial Psychology)
- Identifier: http://hdl.handle.net/10353/17007 , vital:40809
- Description: The study set out to investigate how the Big Five personality traits related to work family conflict, taking into consideration the different forms of work family conflict within the mining industry. The study made use of the quantitative design, with the sample consisting of 270 respondents from the selected mine in South Africa. Probability sampling was used to select respondents from the whole population. Data was analysed using descriptive statistical analysis. To examine the association between variables, linear regression analysis was used. Confirmatory analysis was used to measure validity for work-family conflict (WFC). To measure the validity for personality; face validity, construct and content validity were used. Reliability was measured using the Cronbach alpha. The results of the study showed a significant negative relationship between the personality traits and WFC except for the agreeableness trait. The results also showed significant negative correlations with the different forms of WFC, except for the agreeableness trait. Further, the results showed that, when combined, personality traits had greater variance on the experiences of WFC than each of them separately. The findings of this study are helpful to the mining industry as they assist in the implementation of procedures and policies that will help to reduce WFC and its consequences in the work environment.
- Full Text:
- Date Issued: 2019
- Authors: Ruzungunde, Vongai Sarah
- Date: 2019
- Subjects: Job stress Role conflict Work and family
- Language: English
- Type: Thesis , Doctoral , PhD (Industrial Psychology)
- Identifier: http://hdl.handle.net/10353/17007 , vital:40809
- Description: The study set out to investigate how the Big Five personality traits related to work family conflict, taking into consideration the different forms of work family conflict within the mining industry. The study made use of the quantitative design, with the sample consisting of 270 respondents from the selected mine in South Africa. Probability sampling was used to select respondents from the whole population. Data was analysed using descriptive statistical analysis. To examine the association between variables, linear regression analysis was used. Confirmatory analysis was used to measure validity for work-family conflict (WFC). To measure the validity for personality; face validity, construct and content validity were used. Reliability was measured using the Cronbach alpha. The results of the study showed a significant negative relationship between the personality traits and WFC except for the agreeableness trait. The results also showed significant negative correlations with the different forms of WFC, except for the agreeableness trait. Further, the results showed that, when combined, personality traits had greater variance on the experiences of WFC than each of them separately. The findings of this study are helpful to the mining industry as they assist in the implementation of procedures and policies that will help to reduce WFC and its consequences in the work environment.
- Full Text:
- Date Issued: 2019
Perspectives of South African women and midwives on clinical practice in public maternity units: facilitating the scaling-up of such clinical practices
- Authors: Wibbelink, Margreet
- Date: 2019
- Subjects: Physician practice patterns , Midwives -- South Africa -- Attitudes Pregnant women -- South Africa -- Attitudes Midwifery -- South Africa
- Language: English
- Type: Thesis , Doctoral , DCur
- Identifier: http://hdl.handle.net/10948/44422 , vital:37168
- Description: Despite a steady drop globally in maternal and newborn deaths since 1990, thousands of women and newborns still die each year during pregnancy and childbirth. South Africa, together with other countries, failed to achieve the Millennium Development Goal of reducing maternal mortality by three quarters by 2015. This is despite the positive efforts made in the country towards achieving these goals. However, much more still needs to be done. For that reason, proper and safe care of labouring women remains the identified major focus to prevent these deaths. The current study was the culmination of an investigation into the problem of poor performance regarding maternal and perinatal outcomes as identified by the researcher. The aim of this research study was to understand the experiences and perceptions of the women and the midwives regarding the clinical practices in public maternity units in South Africa in order to facilitate the scaling-up of the midwifery practice. A mixed-methods (sequential exploratory) design was used to answer the research question and objectives, and the study was conducted in three phases. In Phase One, a qualitative research design was implemented. The population were all the midwives in the Eastern Cape who had been working in public maternity units and women who had delivered in those settings. Non-probability purposive sampling with inclusion criteria assisted in selecting a suitable sample. Data collection was done using semi-structured audio-recorded interviews from eleven public sector midwives and eleven women receiving care from the midwives in the Eastern Cape, a province of South Africa. On data analysis, three themes emerged, namely participants had diverse experiences of the midwifery practice, midwives highlighted the burden with regard to the shortage of skilled midwives, and midwives identified managerial issues that affect their performance. Phase Two of the study comprised the quantitative research. The population was the midwives in South Africa who were working in public maternity units and nonprobability purposive sampling criteria were used to select participants. Data collection was done by means of a survey that used a tool adapted from the Hennessy-Hicks Training Needs Analysis Questionnaire. Questions for the survey tool were based on the results of Phase One. A total number of 314 questionnaires were completed, returned and analysed. Phase Three of the study comprised the integration of the results of the first two phases. The study found that midwives were committed to provide quality care but major factors needed to be addressed to facilitate scaling-up of clinical midwifery practices. The midwifery profession needed to be strengthened and an enabling working environment provided. Based on the results of the study as well as the theoretical, conceptual and contextual framework, two strategies were developed: Strategy 1: Empowering midwives to deliver woman-centred care in public sector maternity units Strategy 2: Creating an enabling work environment in order to deliver womancentred care in public sector maternity units.
- Full Text:
- Date Issued: 2019
- Authors: Wibbelink, Margreet
- Date: 2019
- Subjects: Physician practice patterns , Midwives -- South Africa -- Attitudes Pregnant women -- South Africa -- Attitudes Midwifery -- South Africa
- Language: English
- Type: Thesis , Doctoral , DCur
- Identifier: http://hdl.handle.net/10948/44422 , vital:37168
- Description: Despite a steady drop globally in maternal and newborn deaths since 1990, thousands of women and newborns still die each year during pregnancy and childbirth. South Africa, together with other countries, failed to achieve the Millennium Development Goal of reducing maternal mortality by three quarters by 2015. This is despite the positive efforts made in the country towards achieving these goals. However, much more still needs to be done. For that reason, proper and safe care of labouring women remains the identified major focus to prevent these deaths. The current study was the culmination of an investigation into the problem of poor performance regarding maternal and perinatal outcomes as identified by the researcher. The aim of this research study was to understand the experiences and perceptions of the women and the midwives regarding the clinical practices in public maternity units in South Africa in order to facilitate the scaling-up of the midwifery practice. A mixed-methods (sequential exploratory) design was used to answer the research question and objectives, and the study was conducted in three phases. In Phase One, a qualitative research design was implemented. The population were all the midwives in the Eastern Cape who had been working in public maternity units and women who had delivered in those settings. Non-probability purposive sampling with inclusion criteria assisted in selecting a suitable sample. Data collection was done using semi-structured audio-recorded interviews from eleven public sector midwives and eleven women receiving care from the midwives in the Eastern Cape, a province of South Africa. On data analysis, three themes emerged, namely participants had diverse experiences of the midwifery practice, midwives highlighted the burden with regard to the shortage of skilled midwives, and midwives identified managerial issues that affect their performance. Phase Two of the study comprised the quantitative research. The population was the midwives in South Africa who were working in public maternity units and nonprobability purposive sampling criteria were used to select participants. Data collection was done by means of a survey that used a tool adapted from the Hennessy-Hicks Training Needs Analysis Questionnaire. Questions for the survey tool were based on the results of Phase One. A total number of 314 questionnaires were completed, returned and analysed. Phase Three of the study comprised the integration of the results of the first two phases. The study found that midwives were committed to provide quality care but major factors needed to be addressed to facilitate scaling-up of clinical midwifery practices. The midwifery profession needed to be strengthened and an enabling working environment provided. Based on the results of the study as well as the theoretical, conceptual and contextual framework, two strategies were developed: Strategy 1: Empowering midwives to deliver woman-centred care in public sector maternity units Strategy 2: Creating an enabling work environment in order to deliver womancentred care in public sector maternity units.
- Full Text:
- Date Issued: 2019
Perspectives on land and water politics at Mushandike Irrigation Scheme, Masvingo, Zimbabwe
- Authors: Mafukidze, Jonathan
- Date: 2019
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76479 , vital:30573
- Description: Access to, control and ownership of land and water, amongst other natural resources in Zimbabwe, shape and affect rural lives, livelihoods, social relations and social organisation. Rural poverty has been entrenched and exacerbated by, amongst other factors, highly restricted access to these scarce resources. Historically, Zimbabwe’s rural areas (such as communal areas, smallholder irrigation schemes and resettlement areas) have existed as sites of struggles where contestations and negotiations over access to, control or ownership of these resources have taken place. Resultantly, multifaceted and dynamic social relations have been weaved and contested social spaces carved out. In rural Zimbabwe, contestations have tended to be complex, nuanced and intricate, working themselves out in different ways across time and space. In their heightened and more visible state, they have been characterised by violent physical expressions which, in the history of the country, involved two wars of liberation, the First Chimurenga (1896-1897) and the Second Chimurenga (1960s to 1980). The most recent violent manifestation was through nation-wide land invasions, politically christened the Third Chimurenga, which peaked in 2000 and continued sporadically to this day. Few studies on smallholder irrigation schemes in Zimbabwe have focused on understanding how contestations for access to scarce land and water resources are framed and negotiated at the local level. Cognisant of this lacuna, this thesis uses social constructionism in examining, as a case study, Mushandike Smallholder Irrigation Scheme in Masvingo Province in order to understand and analyse how land and water politics occur at the local level. The study deploys a qualitative research methodology approach in examining local water and land politics, which involved original irrigation beneficiaries and more recent land invaders. Findings of the thesis indicate that land and water shortages have increased considerably in the past two decades at the irrigation scheme due to the influx of land invaders into the scheme. This influx has had a negative impact on agricultural production and other livelihood strategies. Both scheme members and land invaders lay claim to land and water at Mushandike. These claims are intricately constructed and contested, and they are linked to broader issues such as partisan party-politics, policy developments, and tradition, origin, indigeneity and belonging. Though the struggles over land and water at Mushandike are firmly rooted in the concrete conditions of existence and experiences of beneficiaries and land invaders, external actors such as political leaders, state bureaucrats and traditional chiefs tend to complicate and intensify the contestations.
- Full Text:
- Date Issued: 2019
- Authors: Mafukidze, Jonathan
- Date: 2019
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76479 , vital:30573
- Description: Access to, control and ownership of land and water, amongst other natural resources in Zimbabwe, shape and affect rural lives, livelihoods, social relations and social organisation. Rural poverty has been entrenched and exacerbated by, amongst other factors, highly restricted access to these scarce resources. Historically, Zimbabwe’s rural areas (such as communal areas, smallholder irrigation schemes and resettlement areas) have existed as sites of struggles where contestations and negotiations over access to, control or ownership of these resources have taken place. Resultantly, multifaceted and dynamic social relations have been weaved and contested social spaces carved out. In rural Zimbabwe, contestations have tended to be complex, nuanced and intricate, working themselves out in different ways across time and space. In their heightened and more visible state, they have been characterised by violent physical expressions which, in the history of the country, involved two wars of liberation, the First Chimurenga (1896-1897) and the Second Chimurenga (1960s to 1980). The most recent violent manifestation was through nation-wide land invasions, politically christened the Third Chimurenga, which peaked in 2000 and continued sporadically to this day. Few studies on smallholder irrigation schemes in Zimbabwe have focused on understanding how contestations for access to scarce land and water resources are framed and negotiated at the local level. Cognisant of this lacuna, this thesis uses social constructionism in examining, as a case study, Mushandike Smallholder Irrigation Scheme in Masvingo Province in order to understand and analyse how land and water politics occur at the local level. The study deploys a qualitative research methodology approach in examining local water and land politics, which involved original irrigation beneficiaries and more recent land invaders. Findings of the thesis indicate that land and water shortages have increased considerably in the past two decades at the irrigation scheme due to the influx of land invaders into the scheme. This influx has had a negative impact on agricultural production and other livelihood strategies. Both scheme members and land invaders lay claim to land and water at Mushandike. These claims are intricately constructed and contested, and they are linked to broader issues such as partisan party-politics, policy developments, and tradition, origin, indigeneity and belonging. Though the struggles over land and water at Mushandike are firmly rooted in the concrete conditions of existence and experiences of beneficiaries and land invaders, external actors such as political leaders, state bureaucrats and traditional chiefs tend to complicate and intensify the contestations.
- Full Text:
- Date Issued: 2019
Ph-responsive liposomal systems for site-specific pulmonary delivery of anti-tubercular drugs
- Nkanga, Christian Isalomboto
- Authors: Nkanga, Christian Isalomboto
- Date: 2019
- Subjects: Tuberculosis -- Chemotherapy , Lipsomes , Drug carriers (Pharmacy) , Rifampin , Hydrogen-ion concentration , Hydrogen-ion concentration -- Physiological effect
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/125832 , vital:35822
- Description: Tuberculosis (TB) is an infectious disease that has been reported to be the ninth leading cause of death worldwide, even though mostly considered as a poverty related disease. Despite the existence of potent anti-tubercular drugs (ATBDs), such as rifampicin (RIF) and isoniazid (INH), TB remains the major killer among many microbial diseases over the last five years. Although several factors are to be blamed for this deadly status, the most crucial issues encompass both the self-defensiveness of the causative agent (Mycobacterium tuberculosis), including its intra-macrophage location that compromises ATBDs accessibility, and the widespread/off target distribution of ATBDs. The need for novel drug delivery strategies therefore arises to provide selective distribution of ATBDs at the infected site. Among the drug vehicles explored in this field, liposomes have been reported to be the most suitable drug carriers due to their rapid uptake by alveolar macrophages, where M. tuberculosis often resides. Since liposomes experience media of different pH throughout the cell uptake process (endocytosis/phagocytosis), the use of pH change as a stimulus for controlled release looks promising for enhancing intra-macrophage delivery and minimizing premature ‘off-target’ release of ATBDs. However, the costly status of liposome technology, due to the use of sophisticated procedures and expensive materials (especially for pH-dependent delivery, where special lipids are required), may preclude wider developments of liposomal products, especially for the developing world. This study aimed at investigating liposomal encapsulation of pH-sensitive and fluorescent hydrazone derivatives of INH using crude soybean lecithin, as a cost-effective option for site-specific delivery combined with potential bio-imaging features. Another objective was to explore encapsulation of INH hydrazone derivatives with and without RIF in liposomes using a simple and organic solvent-free preparation method. Initially, INH was coupled with 4-hydroxy-benzaldehyde to yield a conjugate (INH-HB) that was encapsulated in liposomes using film hydration method with acceptable encapsulation efficiency (î), about 89 %. The prepared INH-HB loaded liposomes (IHL) were characterized by means of dynamic light scattering (DLS), transmission electron microscopy (TEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The release of INH from IHL was evaluated over 12 hours in media of different pH using dialysis. As hypothesized, pH dependent release of INH from IHL was observed with 22, 69, 83 and 100 % release obtained in media of pH 7.4, 6.4, 5.4 and 4.4, respectively. From this experimental trial, further development was undertaken by conjugating INH to a hydrophobic fluorescent tag, zinc (II) phthalocyanine (PC), through hydrazone linkages. The obtained conjugate (PC-INH) was loaded into liposomes (PIL) that were characterized using various spectroscopic techniques, including UV-Vis absorption and energy dispersive X-ray spectroscopy, which suggested the presence of PC-INH within the lipid bilayers. The release study performed in different pH media revealed 22, 41, 97 and 100 % of INH, respectively released at pH 7.4, 6.4, 5.4 and 4.4. This confirmed the potential of pH-triggered drug release from liposomes loaded with hydrazone drug derivatives. In addition, successful encapsulation of PC-INH using crude soybean lecithin inspired a new opening towards development of multimodal liposomes that could achieve controlled drug release with added benefits of image-guided biological tracking. However, the hydrophobic nature of PC-INH requires an effective strategy that could improve its solubility and favour extensive development. In this context, the tetra-substituted structure of PC-INH brought up the hypothesis that cyclodextrin (CD) complexation would facilitate PC-INH encapsulation in liposomes using an organic solvent-free method, called here the “heating method” (HM). Inclusion complexes of PC-INH with various CDs were therefore investigated, with gamma-CD complex (CP) giving the best results. These complexes were prepared in both solution and solid-state and further comprehensively characterized using UV-Vis spectroscopy, magnetic circular dichroism, NMR spectroscopy, diffusion ordered spectroscopy, DSC, XRD and Fourier transform infrared spectroscopy. CP-loaded liposomes prepared using HM exhibited greater î than film hydration liposomes, about 70 % versus 56 %, respectively. The HM-liposomal system (CPL) exhibited potentially useful nano particulate characteristics (i.e. mean particle size 240 nm and Zeta potential –57 mV), which remained unchanged over 5 weeks of stability study at 4 °C, and pH-dependent INH release behaviour alike PIL. Furthermore, CP was co-encapsulated with rifampicin (RIF) in liposomes using HM to investigate the possibility for future combination therapy. 1H-NMR spectroscopy, DSC, XRD and photophysical studies were performed for molecular assessment of the cargo in CP-RIF co-loaded liposomes (CPRL). The mean particle size, Zeta potential and î of CPRL were respectively 594 nm, –50 mV, 58 % for CP and 86 % for RIF. CPRL exhibited much higher release rates for both INH and RIF at pH 6.4, compared to those tested at pH 7.4. In addition, there was no cytotoxicity on HeLa cells, but attractive lung fibroblasts and epithelial cells uptake and viability. Hence, CPRL are promising for targeted ATBD delivery to alveolar macrophages following pulmonary administration. Overall, the developed pH-responsive liposomal system holds the promise for new openings towards wider developments of multifunctional liposomes for site-specific controlled pulmonary delivery of antimicrobials drugs.
- Full Text:
- Date Issued: 2019
- Authors: Nkanga, Christian Isalomboto
- Date: 2019
- Subjects: Tuberculosis -- Chemotherapy , Lipsomes , Drug carriers (Pharmacy) , Rifampin , Hydrogen-ion concentration , Hydrogen-ion concentration -- Physiological effect
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/125832 , vital:35822
- Description: Tuberculosis (TB) is an infectious disease that has been reported to be the ninth leading cause of death worldwide, even though mostly considered as a poverty related disease. Despite the existence of potent anti-tubercular drugs (ATBDs), such as rifampicin (RIF) and isoniazid (INH), TB remains the major killer among many microbial diseases over the last five years. Although several factors are to be blamed for this deadly status, the most crucial issues encompass both the self-defensiveness of the causative agent (Mycobacterium tuberculosis), including its intra-macrophage location that compromises ATBDs accessibility, and the widespread/off target distribution of ATBDs. The need for novel drug delivery strategies therefore arises to provide selective distribution of ATBDs at the infected site. Among the drug vehicles explored in this field, liposomes have been reported to be the most suitable drug carriers due to their rapid uptake by alveolar macrophages, where M. tuberculosis often resides. Since liposomes experience media of different pH throughout the cell uptake process (endocytosis/phagocytosis), the use of pH change as a stimulus for controlled release looks promising for enhancing intra-macrophage delivery and minimizing premature ‘off-target’ release of ATBDs. However, the costly status of liposome technology, due to the use of sophisticated procedures and expensive materials (especially for pH-dependent delivery, where special lipids are required), may preclude wider developments of liposomal products, especially for the developing world. This study aimed at investigating liposomal encapsulation of pH-sensitive and fluorescent hydrazone derivatives of INH using crude soybean lecithin, as a cost-effective option for site-specific delivery combined with potential bio-imaging features. Another objective was to explore encapsulation of INH hydrazone derivatives with and without RIF in liposomes using a simple and organic solvent-free preparation method. Initially, INH was coupled with 4-hydroxy-benzaldehyde to yield a conjugate (INH-HB) that was encapsulated in liposomes using film hydration method with acceptable encapsulation efficiency (î), about 89 %. The prepared INH-HB loaded liposomes (IHL) were characterized by means of dynamic light scattering (DLS), transmission electron microscopy (TEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The release of INH from IHL was evaluated over 12 hours in media of different pH using dialysis. As hypothesized, pH dependent release of INH from IHL was observed with 22, 69, 83 and 100 % release obtained in media of pH 7.4, 6.4, 5.4 and 4.4, respectively. From this experimental trial, further development was undertaken by conjugating INH to a hydrophobic fluorescent tag, zinc (II) phthalocyanine (PC), through hydrazone linkages. The obtained conjugate (PC-INH) was loaded into liposomes (PIL) that were characterized using various spectroscopic techniques, including UV-Vis absorption and energy dispersive X-ray spectroscopy, which suggested the presence of PC-INH within the lipid bilayers. The release study performed in different pH media revealed 22, 41, 97 and 100 % of INH, respectively released at pH 7.4, 6.4, 5.4 and 4.4. This confirmed the potential of pH-triggered drug release from liposomes loaded with hydrazone drug derivatives. In addition, successful encapsulation of PC-INH using crude soybean lecithin inspired a new opening towards development of multimodal liposomes that could achieve controlled drug release with added benefits of image-guided biological tracking. However, the hydrophobic nature of PC-INH requires an effective strategy that could improve its solubility and favour extensive development. In this context, the tetra-substituted structure of PC-INH brought up the hypothesis that cyclodextrin (CD) complexation would facilitate PC-INH encapsulation in liposomes using an organic solvent-free method, called here the “heating method” (HM). Inclusion complexes of PC-INH with various CDs were therefore investigated, with gamma-CD complex (CP) giving the best results. These complexes were prepared in both solution and solid-state and further comprehensively characterized using UV-Vis spectroscopy, magnetic circular dichroism, NMR spectroscopy, diffusion ordered spectroscopy, DSC, XRD and Fourier transform infrared spectroscopy. CP-loaded liposomes prepared using HM exhibited greater î than film hydration liposomes, about 70 % versus 56 %, respectively. The HM-liposomal system (CPL) exhibited potentially useful nano particulate characteristics (i.e. mean particle size 240 nm and Zeta potential –57 mV), which remained unchanged over 5 weeks of stability study at 4 °C, and pH-dependent INH release behaviour alike PIL. Furthermore, CP was co-encapsulated with rifampicin (RIF) in liposomes using HM to investigate the possibility for future combination therapy. 1H-NMR spectroscopy, DSC, XRD and photophysical studies were performed for molecular assessment of the cargo in CP-RIF co-loaded liposomes (CPRL). The mean particle size, Zeta potential and î of CPRL were respectively 594 nm, –50 mV, 58 % for CP and 86 % for RIF. CPRL exhibited much higher release rates for both INH and RIF at pH 6.4, compared to those tested at pH 7.4. In addition, there was no cytotoxicity on HeLa cells, but attractive lung fibroblasts and epithelial cells uptake and viability. Hence, CPRL are promising for targeted ATBD delivery to alveolar macrophages following pulmonary administration. Overall, the developed pH-responsive liposomal system holds the promise for new openings towards wider developments of multifunctional liposomes for site-specific controlled pulmonary delivery of antimicrobials drugs.
- Full Text:
- Date Issued: 2019
Photophysical properties and photodynamic therapy activities of symmetrical and asymmetrical porphyrins embedded into Pluronic polymer micelles and nonlinear optical properties of an asymmetrical phthalocyanine
- Authors: Managa, Muthumuni Elizabeth
- Date: 2019
- Subjects: Porphyrins , Phthalocyanines
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/67625 , vital:29122
- Description: This work reports on the synthesis of symmetrical and asymmetrical novel porphyrins that have been incorporated into Pluronic polymers, as well as the synthesis of asymmetrical phthalocyanine. The new compounds were characterized by elemental analysis, Fourier-transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (1H NMR), mass spectrometry and UV–Visible spectroscopy. The porphyrins that are synthesised were not water soluble but upon incorporating into Pluronic polymer micelles, they became water soluble. The polymer was also modified and linked to folic acid, to enhance selectivity for photodynamic therapy application, where MCF7 breast cancer cells were used. The singlet oxygen quantum yields were lower for the metal free porphyrins as compared to metalled ones due to the heavy atom effect of ClGa, Zn and Cl2Si in the latter which encourages intersystem crossing to the triplet state. Singlet oxygen quantum yields for water soluble derivatives increased upon being encapsulated into the micelles for all. The Stern-Volmer constant (Ksv), binding constant (Kb) and number of binding sites (n) were investigated in order to understand the interaction between the polymer micelles and the porphyrins, and it was showed that the central metals play a role in the manner which the porphyrin interacts with the micelles. The dark toxicity and photodynamic activity of the novel porphyrins upon encapsulating to Pluronic polymer micelles is also reported. There was minimal dark toxicity for all complexes with > 90% cell survival. The photodynamic activity of water insoluble porphyrins improved when encapsulated into the micelles. Novel asymmetrical phthalocyanines were also synthesised for nonlinear optics (NLO) studies in solution and thin films.
- Full Text:
- Date Issued: 2019
- Authors: Managa, Muthumuni Elizabeth
- Date: 2019
- Subjects: Porphyrins , Phthalocyanines
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/67625 , vital:29122
- Description: This work reports on the synthesis of symmetrical and asymmetrical novel porphyrins that have been incorporated into Pluronic polymers, as well as the synthesis of asymmetrical phthalocyanine. The new compounds were characterized by elemental analysis, Fourier-transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (1H NMR), mass spectrometry and UV–Visible spectroscopy. The porphyrins that are synthesised were not water soluble but upon incorporating into Pluronic polymer micelles, they became water soluble. The polymer was also modified and linked to folic acid, to enhance selectivity for photodynamic therapy application, where MCF7 breast cancer cells were used. The singlet oxygen quantum yields were lower for the metal free porphyrins as compared to metalled ones due to the heavy atom effect of ClGa, Zn and Cl2Si in the latter which encourages intersystem crossing to the triplet state. Singlet oxygen quantum yields for water soluble derivatives increased upon being encapsulated into the micelles for all. The Stern-Volmer constant (Ksv), binding constant (Kb) and number of binding sites (n) were investigated in order to understand the interaction between the polymer micelles and the porphyrins, and it was showed that the central metals play a role in the manner which the porphyrin interacts with the micelles. The dark toxicity and photodynamic activity of the novel porphyrins upon encapsulating to Pluronic polymer micelles is also reported. There was minimal dark toxicity for all complexes with > 90% cell survival. The photodynamic activity of water insoluble porphyrins improved when encapsulated into the micelles. Novel asymmetrical phthalocyanines were also synthesised for nonlinear optics (NLO) studies in solution and thin films.
- Full Text:
- Date Issued: 2019
Physicochemical properties and photodynamic therapy activities of indium and zinc phthalocyanine-nanoparticle conjugates
- Authors: Dube, Edith
- Date: 2019
- Subjects: Indium , Zinc , Phthalocyanines , Breast -- Cancer -- Photochemotherapy , Nanoparticles
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76506 , vital:30589
- Description: The syntheses and characterization of symmetric and asymmetric Pcs functionalized at the peripheral position are reported. The Pcs contain either zinc or indium as central metals and have carboxyphenoxy, phenoxy propanoic acid, benzothiazole phenoxy, thiophine ethoxy or di-O-isopropylidene-α-D-glucopyranose as ring substituents. The Pcs were linked to NPs via an amide bond or through self-assembly. The photophysics and photochemistry of the Pcs were assessed when alone and with conjugates. All the studied Pcs showed good photophysicochemical behaviour with relatively high triplet and singlet oxygen quantum yields corresponding to their low fluorescence quantum yield. The Pcs with indium in their central cavity exhibited higher triplet and singlet oxygen quantum yields in comparison to their zinc counterparts due to the heavy–atom effect obtained from the former. Asymmetrical Pcs displayed higher triplet and singlet oxygen quantum yields than their symmetrical counterparts. The triplet quantum yield, generally increased on linkage to nanoparticles (NPs) due to the heavy–atom effect of gold and silver in NPs. The conjugates to gold nanospheres yielded higher triplet and singlet quantum yields than their gold nanotriangles counterparts due to the higher loading by the former probably encouraged by their relatively small particle size. The in vitro dark cytotoxicity and photodynamic therapy of selected Pc complexes and conjugates against MCF-7 cells was tested. All studied Pc complexes and conjugates showed minimum dark toxicity making them applicable for PDT. All complexes displayed poor phototoxicity with >50Îll viability at concentrations≤ 160μg/mL, however the conjugates showed<50% cell viabilityatconcentrations≤ 160μg/mLprobably due to the enhanced singlet oxygen quantum yield. The findings from this work show the importance of linking photosensitises such as phthalocyanines to metal nanoparticles for the enhancement ofsinglet oxygen quantum yield and ultimately the photodynamic effect.
- Full Text:
- Date Issued: 2019
- Authors: Dube, Edith
- Date: 2019
- Subjects: Indium , Zinc , Phthalocyanines , Breast -- Cancer -- Photochemotherapy , Nanoparticles
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76506 , vital:30589
- Description: The syntheses and characterization of symmetric and asymmetric Pcs functionalized at the peripheral position are reported. The Pcs contain either zinc or indium as central metals and have carboxyphenoxy, phenoxy propanoic acid, benzothiazole phenoxy, thiophine ethoxy or di-O-isopropylidene-α-D-glucopyranose as ring substituents. The Pcs were linked to NPs via an amide bond or through self-assembly. The photophysics and photochemistry of the Pcs were assessed when alone and with conjugates. All the studied Pcs showed good photophysicochemical behaviour with relatively high triplet and singlet oxygen quantum yields corresponding to their low fluorescence quantum yield. The Pcs with indium in their central cavity exhibited higher triplet and singlet oxygen quantum yields in comparison to their zinc counterparts due to the heavy–atom effect obtained from the former. Asymmetrical Pcs displayed higher triplet and singlet oxygen quantum yields than their symmetrical counterparts. The triplet quantum yield, generally increased on linkage to nanoparticles (NPs) due to the heavy–atom effect of gold and silver in NPs. The conjugates to gold nanospheres yielded higher triplet and singlet quantum yields than their gold nanotriangles counterparts due to the higher loading by the former probably encouraged by their relatively small particle size. The in vitro dark cytotoxicity and photodynamic therapy of selected Pc complexes and conjugates against MCF-7 cells was tested. All studied Pc complexes and conjugates showed minimum dark toxicity making them applicable for PDT. All complexes displayed poor phototoxicity with >50Îll viability at concentrations≤ 160μg/mL, however the conjugates showed<50% cell viabilityatconcentrations≤ 160μg/mLprobably due to the enhanced singlet oxygen quantum yield. The findings from this work show the importance of linking photosensitises such as phthalocyanines to metal nanoparticles for the enhancement ofsinglet oxygen quantum yield and ultimately the photodynamic effect.
- Full Text:
- Date Issued: 2019
Physiological and mechanistic characteristics of all-out running using the critical speed concept
- Authors: Kramer, Mark
- Date: 2019
- Subjects: Aerobic exercises , Physical fitness Running Exercise
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/40511 , vital:36178
- Description: The studies described in this thesis, as far as could be ascertained, were the first to investigate the physiological and mechanistic characteristics of all-out running using the critical speed concept specifically applied to field-sport athletes. In the first study the oxygen uptake (𝑉̇𝑂2) kinetics of linear and shuttle all-out running were investigated. The 𝑉̇𝑂2 kinetic parameters were also related to parameters derived from a graded exercise test. No differences were observed in all 𝑉̇ 𝑂2 kinetic parameters between all-out linear and shuttle running, even though differences in all-out testing parameters were evident. The study was novel in that it was, as far as could be ascertained, the first to implement and investigate differences in 𝑉̇𝑂2 kinetics applied to all-out running. The second study investigated whether the parameters derived from all-out linear and shuttle running were representative of aerobic fitness, and the extent to which the all-out test (AOT) related to already established evaluations of aerobic fitness (e.g., graded exercise test [GXT] and the Yo-Yo intermittent recovery test [YYIR1]). It was also investigated whether the parameters from the AOTs could be used to predict the time to completion (tLIM) of shuttle-based performances. The outcomes of this study showed that both the linear and 50-m AOTs were indeed valid for the aerobic assessment of fitness by showing high correlations with maximal pulmonary oxygen uptake (𝑉̇𝑂2𝑚𝑎𝑥). Both the linear and 50-m AOT could therefore be used as surrogates for the evaluation of aerobic fitness. Interestingly, in terms of the tLIM prediction, the 25-m AOT showed the greatest utility. This study was novel on several fronts in that it was the first to: (1) investigate the physiological link between linear and shuttle AOTs and the GXT, (2) investigate the difference between AOTs and the YYIR1, and (3) investigate the application of the AOT methodology to field-based athletes such as rugby players. The third study investigated the energetic cost (EC) of locomotion as well as the metabolic power (𝑃̇) required to run at given speeds. The energetic approach provides a more robust evaluation of the differences between linear and shuttle running due to the all-out nature of the tests. Conventional methods of energy assessment often fall short due to the preclusion of a physiological steady-state, hence requiring more robust mathematical models to evaluate all-out running performance. The results of this study showed that differences between linear and shuttle AOTs are more likely neuromuscular as opposed to physiological. Peak EC and 𝑃̇ were significantly greater for shuttle running compared to linear running, showing clear non-linear increases with each successive increase in running speed. However, the mean EC and 𝑃̇ were not different, showing that all-out shuttle running ‘balances’ the lower running speeds (implying a lower physiological load compared to linear running) with the higher metabolic load imposed by the intense directional changes. This study was novel as it was, as far as could be ascertained, the first to apply the energetic approach to all-out running as well as investigate the differences in energetics between linear and shuttle AOTs. The fourth study provided a means by which the speed-time characteristics of all-out running could be objectively quantified. A novel bi-exponential model was applied to both the linear and shuttle speed-time curves and allowed various mechanistic aspects of the speed-time curve to be characterized. Conventional assessment of the AOT allows for the derivation of only two key parameters, namely critical speed (CS) and the finite distance achievable at speeds exceeding CS (D’). The application of the bi-exponential model expands the number of useful parameters that can be derived from an AOT to seven. The additional useful parameters include: maximum speed [𝑆𝑚𝑎𝑥], time to maximum speed [𝑡𝑐], amplitude of the difference between 𝑆𝑚𝑎𝑥 and CS [𝐴𝑑], curvature constant of the exponential decay [𝜏𝑑] and the asymptote of the exponential decay function [𝑆0], fatigue index showing the percent decline between 𝑆𝑚𝑎𝑥 and CS [FI%], and the finite capacity for running at speeds exceeding CS [D’; representing the area under the curve that is above CS]. The CS and D’ parameters derived from the bi-exponential model were not different to the CS and D’ parameters derived using the conventional method of analysis, thereby showing that the bi-exponential model is a valid means of assessing the curvature characteristics of the AOT, as well as providing additional information that cannot be gleaned from the traditional approach.
- Full Text:
- Date Issued: 2019
- Authors: Kramer, Mark
- Date: 2019
- Subjects: Aerobic exercises , Physical fitness Running Exercise
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/40511 , vital:36178
- Description: The studies described in this thesis, as far as could be ascertained, were the first to investigate the physiological and mechanistic characteristics of all-out running using the critical speed concept specifically applied to field-sport athletes. In the first study the oxygen uptake (𝑉̇𝑂2) kinetics of linear and shuttle all-out running were investigated. The 𝑉̇𝑂2 kinetic parameters were also related to parameters derived from a graded exercise test. No differences were observed in all 𝑉̇ 𝑂2 kinetic parameters between all-out linear and shuttle running, even though differences in all-out testing parameters were evident. The study was novel in that it was, as far as could be ascertained, the first to implement and investigate differences in 𝑉̇𝑂2 kinetics applied to all-out running. The second study investigated whether the parameters derived from all-out linear and shuttle running were representative of aerobic fitness, and the extent to which the all-out test (AOT) related to already established evaluations of aerobic fitness (e.g., graded exercise test [GXT] and the Yo-Yo intermittent recovery test [YYIR1]). It was also investigated whether the parameters from the AOTs could be used to predict the time to completion (tLIM) of shuttle-based performances. The outcomes of this study showed that both the linear and 50-m AOTs were indeed valid for the aerobic assessment of fitness by showing high correlations with maximal pulmonary oxygen uptake (𝑉̇𝑂2𝑚𝑎𝑥). Both the linear and 50-m AOT could therefore be used as surrogates for the evaluation of aerobic fitness. Interestingly, in terms of the tLIM prediction, the 25-m AOT showed the greatest utility. This study was novel on several fronts in that it was the first to: (1) investigate the physiological link between linear and shuttle AOTs and the GXT, (2) investigate the difference between AOTs and the YYIR1, and (3) investigate the application of the AOT methodology to field-based athletes such as rugby players. The third study investigated the energetic cost (EC) of locomotion as well as the metabolic power (𝑃̇) required to run at given speeds. The energetic approach provides a more robust evaluation of the differences between linear and shuttle running due to the all-out nature of the tests. Conventional methods of energy assessment often fall short due to the preclusion of a physiological steady-state, hence requiring more robust mathematical models to evaluate all-out running performance. The results of this study showed that differences between linear and shuttle AOTs are more likely neuromuscular as opposed to physiological. Peak EC and 𝑃̇ were significantly greater for shuttle running compared to linear running, showing clear non-linear increases with each successive increase in running speed. However, the mean EC and 𝑃̇ were not different, showing that all-out shuttle running ‘balances’ the lower running speeds (implying a lower physiological load compared to linear running) with the higher metabolic load imposed by the intense directional changes. This study was novel as it was, as far as could be ascertained, the first to apply the energetic approach to all-out running as well as investigate the differences in energetics between linear and shuttle AOTs. The fourth study provided a means by which the speed-time characteristics of all-out running could be objectively quantified. A novel bi-exponential model was applied to both the linear and shuttle speed-time curves and allowed various mechanistic aspects of the speed-time curve to be characterized. Conventional assessment of the AOT allows for the derivation of only two key parameters, namely critical speed (CS) and the finite distance achievable at speeds exceeding CS (D’). The application of the bi-exponential model expands the number of useful parameters that can be derived from an AOT to seven. The additional useful parameters include: maximum speed [𝑆𝑚𝑎𝑥], time to maximum speed [𝑡𝑐], amplitude of the difference between 𝑆𝑚𝑎𝑥 and CS [𝐴𝑑], curvature constant of the exponential decay [𝜏𝑑] and the asymptote of the exponential decay function [𝑆0], fatigue index showing the percent decline between 𝑆𝑚𝑎𝑥 and CS [FI%], and the finite capacity for running at speeds exceeding CS [D’; representing the area under the curve that is above CS]. The CS and D’ parameters derived from the bi-exponential model were not different to the CS and D’ parameters derived using the conventional method of analysis, thereby showing that the bi-exponential model is a valid means of assessing the curvature characteristics of the AOT, as well as providing additional information that cannot be gleaned from the traditional approach.
- Full Text:
- Date Issued: 2019
Plants, people, and place: complex, mutualistic, and co-evolving global patterns through time
- Authors: Van Wijk, Yvette Ethné
- Date: 2019
- Subjects: Ethnobotany -- South Africa -- Western Cape , Khoisan (African people) -- Ethnobotany , Human-plant relationships -- South Africa -- Western Cape , Plants -- Classification -- South Africa -- Western Cape , Plant remains (Archaeology) -- South Africa -- Western Cape , Ethnoscience -- South Africa -- Western Cape , Regression analysis
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76575 , vital:30609
- Description: My thesis studies and analyses the suite of distinctive plant taxa which persist in small patches of vegetation growing in close association with archaeological habitation sites in the southern Cape, South Africa. The unexpected correlation and overlap between botanical taxa collected at 75 site complexes, and ethnobotanical data collected in collaboration with modern Khoi-San communities in the same area, is explored and interrogated. Although sparse, reports of the same suite of taxa recovered from archaeological excavations in the Cape provinces provides depth of time to the study, linking the past to the present. The three-way correlation of a suite of plants closely associated with humans and habitation sites through time, allows for triangulation of the data in order to validate and cross verify the results using more than one frame of reference. Both the plants and the knowledge about their uses have persisted in spite of historical attrition, and alienation of land and language, suffered by the Khoi-San over the past 300 years. Drawing on a large body of primary and secondary data, and using an interdisciplinary, abductive and pragmatic mixed methods approach, a pattern can be traced throughout Africa and globally. Regression analysis strongly indicates that the most ubiquitous taxa were selected for a purpose and are not randomly present in association with humans. Botanical, anthropological, and archaeological studies seldom focus on the inter-connectedness of people and plants at the sites they inhabited. Very little research into modern vegetation in close association with the sites has been undertaken, and vegetation mapping has not captured the occurrence of these site-specific small vegetation patches recorded during my surveys. The topographically, geologically, and vegetatively complex and varied southern Cape, and greater Cape area, is extremely rich in archaeological sites and history. This study suggests that the value of site-specific plant taxa to humans throughout the aeons of pre-agricultural history, persists into the present. Due to tolerance of a broad range of climatic and environmental variables, there is value in the study of these ancient and neglected useful plants in the face of climate change. That this vegetation is so closely associated with archaeological sites of cultural and historic importance confers an urgency to recognising the existence and significance of the distinctive and possibly anthropogenic vegetation surrounding the sites.
- Full Text:
- Date Issued: 2019
- Authors: Van Wijk, Yvette Ethné
- Date: 2019
- Subjects: Ethnobotany -- South Africa -- Western Cape , Khoisan (African people) -- Ethnobotany , Human-plant relationships -- South Africa -- Western Cape , Plants -- Classification -- South Africa -- Western Cape , Plant remains (Archaeology) -- South Africa -- Western Cape , Ethnoscience -- South Africa -- Western Cape , Regression analysis
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76575 , vital:30609
- Description: My thesis studies and analyses the suite of distinctive plant taxa which persist in small patches of vegetation growing in close association with archaeological habitation sites in the southern Cape, South Africa. The unexpected correlation and overlap between botanical taxa collected at 75 site complexes, and ethnobotanical data collected in collaboration with modern Khoi-San communities in the same area, is explored and interrogated. Although sparse, reports of the same suite of taxa recovered from archaeological excavations in the Cape provinces provides depth of time to the study, linking the past to the present. The three-way correlation of a suite of plants closely associated with humans and habitation sites through time, allows for triangulation of the data in order to validate and cross verify the results using more than one frame of reference. Both the plants and the knowledge about their uses have persisted in spite of historical attrition, and alienation of land and language, suffered by the Khoi-San over the past 300 years. Drawing on a large body of primary and secondary data, and using an interdisciplinary, abductive and pragmatic mixed methods approach, a pattern can be traced throughout Africa and globally. Regression analysis strongly indicates that the most ubiquitous taxa were selected for a purpose and are not randomly present in association with humans. Botanical, anthropological, and archaeological studies seldom focus on the inter-connectedness of people and plants at the sites they inhabited. Very little research into modern vegetation in close association with the sites has been undertaken, and vegetation mapping has not captured the occurrence of these site-specific small vegetation patches recorded during my surveys. The topographically, geologically, and vegetatively complex and varied southern Cape, and greater Cape area, is extremely rich in archaeological sites and history. This study suggests that the value of site-specific plant taxa to humans throughout the aeons of pre-agricultural history, persists into the present. Due to tolerance of a broad range of climatic and environmental variables, there is value in the study of these ancient and neglected useful plants in the face of climate change. That this vegetation is so closely associated with archaeological sites of cultural and historic importance confers an urgency to recognising the existence and significance of the distinctive and possibly anthropogenic vegetation surrounding the sites.
- Full Text:
- Date Issued: 2019
Political education as a determinant of university students’ political participation in the Eastern Cape, South Africa
- Authors: Badaru, Kazeem Ajasa
- Date: 2019
- Subjects: Citizenship -- Study and teaching -- South Africa Democracy and education -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/15793 , vital:40524
- Description: Globally, there is a downward trend in youths’ political interest and participation in the learning of political education in their school curricula as a measure to combat the apparent dangers posed by the declining young citizens’ participation in the political processes.This study therefore investigated political education as a determinant of university students’ political participation in the Province of the Eastern Cape, South Africa. The study employed a mixed methods design. Using the probability sampling technique, a sample of 375 participants was randomly selected from one university in the Eastern Cape Province while semi-structured interviews were conducted among five (5) purposively selected members of the same university’s Student Representative Council (SRC) executive committee. Simple descriptive statistics such as frequency counts and percentages were used to summarize all categories of variables; while Pearson correlation statistics, Chi-square and Ordinary least square regression were used to examine the relationship between dependent and independent variables at a 95percent confidence interval. Alpha values less than 0.05 were considered to be statistically significant. Thematic content analysis was performed on the qualitative data. The quantitative analysis revealed that students’ level of political awareness was high; 98.1percent of them were aware of their rights to vote and be voted for. Students’ political judgment was positively correlated with participation in campus (r =0.182) and national politics (r = 0.030) respectively. Most of the students agreed to take part in the 2018 SRC (78.8percent) and 2019 national elections (77.9percent) respectively. Political interest was significantly correlated with participation in campus (r = 0.375) and national politics (r =0. 404). The findings from the multivariate analysis showed that political interest (<0.001), parents’ political involvement (<0.001) and year of study (<0.001) were the significant determinants of students’ participation in politics. The qualitative findings also showed that there was a positive relationship between political education and students’ participation in politics. Since political interest and family are element and agent of political education respectively, it is concluded that political education is to a large extent a determinant of university students’ political participation. It is recommended that the universities, the Department of Higher Education and Training (DHET) and other stakeholders should do a thorough review of the university education curricula and programmes to ensure that political education is adequately accommodated and taken care of in a way that would increase students’ interest, awareness and participation in politics. When this is amply done, students’ cognitive skills and capacities would be enhanced to increase their participation in the political processes in South Africa.
- Full Text:
- Date Issued: 2019
- Authors: Badaru, Kazeem Ajasa
- Date: 2019
- Subjects: Citizenship -- Study and teaching -- South Africa Democracy and education -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/15793 , vital:40524
- Description: Globally, there is a downward trend in youths’ political interest and participation in the learning of political education in their school curricula as a measure to combat the apparent dangers posed by the declining young citizens’ participation in the political processes.This study therefore investigated political education as a determinant of university students’ political participation in the Province of the Eastern Cape, South Africa. The study employed a mixed methods design. Using the probability sampling technique, a sample of 375 participants was randomly selected from one university in the Eastern Cape Province while semi-structured interviews were conducted among five (5) purposively selected members of the same university’s Student Representative Council (SRC) executive committee. Simple descriptive statistics such as frequency counts and percentages were used to summarize all categories of variables; while Pearson correlation statistics, Chi-square and Ordinary least square regression were used to examine the relationship between dependent and independent variables at a 95percent confidence interval. Alpha values less than 0.05 were considered to be statistically significant. Thematic content analysis was performed on the qualitative data. The quantitative analysis revealed that students’ level of political awareness was high; 98.1percent of them were aware of their rights to vote and be voted for. Students’ political judgment was positively correlated with participation in campus (r =0.182) and national politics (r = 0.030) respectively. Most of the students agreed to take part in the 2018 SRC (78.8percent) and 2019 national elections (77.9percent) respectively. Political interest was significantly correlated with participation in campus (r = 0.375) and national politics (r =0. 404). The findings from the multivariate analysis showed that political interest (<0.001), parents’ political involvement (<0.001) and year of study (<0.001) were the significant determinants of students’ participation in politics. The qualitative findings also showed that there was a positive relationship between political education and students’ participation in politics. Since political interest and family are element and agent of political education respectively, it is concluded that political education is to a large extent a determinant of university students’ political participation. It is recommended that the universities, the Department of Higher Education and Training (DHET) and other stakeholders should do a thorough review of the university education curricula and programmes to ensure that political education is adequately accommodated and taken care of in a way that would increase students’ interest, awareness and participation in politics. When this is amply done, students’ cognitive skills and capacities would be enhanced to increase their participation in the political processes in South Africa.
- Full Text:
- Date Issued: 2019