Effects of nitrogen and phosphorus rates, leaf age and drying technique on growth and nutritional contents of Moringa oleifera
- Authors: Sokombela, Asanda
- Date: 2019
- Subjects: Moringa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12117 , vital:39153
- Description: In general, smallholder farmers tend to use large quantities of soil nutrients without replenishment with manure, compost and fertiliser in order to replace the soil nutrients that are lost. Considering the low soil fertility status of soils in South Africa, this study was conducted with an aim of developing agronomic protocols for the production of moringa in order to fight malnutrition and produce supplement feed for animals. Moringa contains various nutrients and chemicals, such as, protein, which are sensitive to heat, and there is therefore a need to establish the best drying method which does not affect the nutrient content and quality of moringa. Physiological age is probably the most important factor influencing the mineral composition of plants. The relationship between nutrient concentration and leaf age is not fundamentally altered by crop load, soil type, climate or cultural practices, such that nutrients may be displaced vertically by the level of supply. Leaf age is one of the factors that affect the distribution of nutrients in the leaves of plants. Therefore, studies were conducted to evaluate the response of Moringa oleifera leaf yield and nutritional content to nitrogen and phosphorus rates, leaf age/position, and drying techniques. The experiments were conducted at the University of Fort Hare Alice Campus research farm. The experiment that investigated the effect of N and P rates was carried out in potted plants filled fine silica sand. The seeds were sown on black polythene bags, filled with a mixture of soil, pine bark and goat manure (at 1:2:1 ratio, respectively) at a depth of 2 cm. At 30 cm height, the seedlings were transplanted into 5-liter pots, which were filled with building sand as growing media. The experiment was a 4 x 3 factorial, with four levels of nitrogen (100, 200, 300 and 400 kg/ha) and three levels of phosphorus (40, 80 and 120 kg/ha). The experiment was laid-out as randomised complete block design (RCBD), with 12 treatment combinations replicated four times. All experimental units received the same amount of potassium (731kg/ha) in the form of KCl. Nitrogen treatments which were applied were split in two equal applications, at transplanting stage and 4 weeks later. The phosphorus rates were applied as superphosphate once mixed to the potting media before transplanting. Growth parameters such as plant height, root collar diameters, number of leaves, dry and fresh leaf masses were measured. Powdered dry leaves were also analysed to determine iv metabolite such as crude protein, ash, moisture, fat and fibre constituents (ADF and NDF). Micro and macro mineral nutrients were also determined using atomic absorption spectroscopy technique (AAS). The results showed that growth of moringa significantly increased through the application of fertilizer. The results from the (ANOVA) table showed no interaction between phosphorus and nitrogen on growth parameters such as number of leaves, stem width and plant height of moringa in this study. Nitrogen levels, as treatments, have significantly affected the growth of the plant. However, phosphorus, as a treatment, showed no significant difference on growth parameteres of Moringa. It was evident that trees that received the highest nitrogen rate (400 kg/ha) resulted in thickest stem girth, tallest trees and the highest number of leaves. The overall results revealed that moringa leaf powder contained appreciable amount nutrients. Crude protein was notably high (38.23%) in the trees that received the highest phosphorus and nitrogen combination treatment (400 kg/ha N x 120 kg/ha P treatment combination. The highest ash content of (14.17%) and (14.21%) were recorded from the trees that received treatment combination of 200 kg/ha N x 80 kg/ha P and 100 kg/ha N x 120 kg/ha P, and significantly differed from the rest of the other treatment combinations. The fat content steadily increased with an increase in nitrogen rate. Increase in P level resulted in a decrease in fat content. The overall findings confirm that combinations of the higher levels of N and P result in a decrease in fat content. The variation in the metabolite nutrients and mineral nutrient values may be due to differences in age of the leaves or positions and possibly due to different stages of maturity of leaves. The second experiment was conducted in the field at the research farm. The aim was to evaluate the effect of leaf age/position on nutrient distribution of moringa. The seeds were sown in black polythene bags at a depth of 2 cm. The bags were filled with a mixture of 1 part of soil, 2 parts of pine bark: and 1 part of manure. The seedlings were transplanted into the field when they reached the height of 30cm. Plants were laid-out as a CRD design with 5 replications. Three leaf positions, upper, middle and basal leaves, were used as treatments to determine the nutrient variation within a parent plant. Leaves of each position were harvested separately, washed with tap water and air-dried in shade condition. The dried leaves were analysed for metabolite and mineral content. The Association of official agricultural chemists (AOAC) methods were used to determine protein, fat, fibre, and ash. Atomic absorption spectrometry (AAS) technique was used to analyse minerals v such as iron, zinc, copper, manganese and macro-minerals such as calcium, magnesium, potassium, sodium and phosphorus. The study showed that ash, fat, NDF and ADF contents were significantly higher in the basal leaves as compared to that in the middle and upper leaves. However, moisture and crude protein contents were significantly higher in the upper leaves compared to both in the middle and basal leaves. The basal leaves accumulated significantly higher Ca, Mg, K, Na and Mn contents. The concentrations of P, Zn, Cu and Fe were, on the other hand, significantly higher in the younger leaves compared to that in the middle and basal leaves. It can be concluded that the upper (younger) leaves contain enough nutrition to satisfy the dietary requirements. In addition, these leaves have low levels of oxalate, cyanide and nitrate, which can cause health problems. To determine the effect of drying method on nutrition content of moringa leaves, three drying methods (shade-, sun- and oven-drying methods) were applied as treatments. Moringa plants were grown at the Research Farm of the University of Fort Hare, Alice campus. The leaves were harvested, thoroughly mixed, washed with tap water and put into 15 brown paper bags. The 15 samples (paper bags) were distributed to the three drying treatments (each treatment replicated 5 times). The dried samples were analysed for metabolites and mineral content as per AOAC and AAS methods, respectively. The study showed that shade-drying method retained higher metabolites. Thus, this study recommends the shade-drying method in preserving moringa leaves.
- Full Text:
- Date Issued: 2019
- Authors: Sokombela, Asanda
- Date: 2019
- Subjects: Moringa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12117 , vital:39153
- Description: In general, smallholder farmers tend to use large quantities of soil nutrients without replenishment with manure, compost and fertiliser in order to replace the soil nutrients that are lost. Considering the low soil fertility status of soils in South Africa, this study was conducted with an aim of developing agronomic protocols for the production of moringa in order to fight malnutrition and produce supplement feed for animals. Moringa contains various nutrients and chemicals, such as, protein, which are sensitive to heat, and there is therefore a need to establish the best drying method which does not affect the nutrient content and quality of moringa. Physiological age is probably the most important factor influencing the mineral composition of plants. The relationship between nutrient concentration and leaf age is not fundamentally altered by crop load, soil type, climate or cultural practices, such that nutrients may be displaced vertically by the level of supply. Leaf age is one of the factors that affect the distribution of nutrients in the leaves of plants. Therefore, studies were conducted to evaluate the response of Moringa oleifera leaf yield and nutritional content to nitrogen and phosphorus rates, leaf age/position, and drying techniques. The experiments were conducted at the University of Fort Hare Alice Campus research farm. The experiment that investigated the effect of N and P rates was carried out in potted plants filled fine silica sand. The seeds were sown on black polythene bags, filled with a mixture of soil, pine bark and goat manure (at 1:2:1 ratio, respectively) at a depth of 2 cm. At 30 cm height, the seedlings were transplanted into 5-liter pots, which were filled with building sand as growing media. The experiment was a 4 x 3 factorial, with four levels of nitrogen (100, 200, 300 and 400 kg/ha) and three levels of phosphorus (40, 80 and 120 kg/ha). The experiment was laid-out as randomised complete block design (RCBD), with 12 treatment combinations replicated four times. All experimental units received the same amount of potassium (731kg/ha) in the form of KCl. Nitrogen treatments which were applied were split in two equal applications, at transplanting stage and 4 weeks later. The phosphorus rates were applied as superphosphate once mixed to the potting media before transplanting. Growth parameters such as plant height, root collar diameters, number of leaves, dry and fresh leaf masses were measured. Powdered dry leaves were also analysed to determine iv metabolite such as crude protein, ash, moisture, fat and fibre constituents (ADF and NDF). Micro and macro mineral nutrients were also determined using atomic absorption spectroscopy technique (AAS). The results showed that growth of moringa significantly increased through the application of fertilizer. The results from the (ANOVA) table showed no interaction between phosphorus and nitrogen on growth parameters such as number of leaves, stem width and plant height of moringa in this study. Nitrogen levels, as treatments, have significantly affected the growth of the plant. However, phosphorus, as a treatment, showed no significant difference on growth parameteres of Moringa. It was evident that trees that received the highest nitrogen rate (400 kg/ha) resulted in thickest stem girth, tallest trees and the highest number of leaves. The overall results revealed that moringa leaf powder contained appreciable amount nutrients. Crude protein was notably high (38.23%) in the trees that received the highest phosphorus and nitrogen combination treatment (400 kg/ha N x 120 kg/ha P treatment combination. The highest ash content of (14.17%) and (14.21%) were recorded from the trees that received treatment combination of 200 kg/ha N x 80 kg/ha P and 100 kg/ha N x 120 kg/ha P, and significantly differed from the rest of the other treatment combinations. The fat content steadily increased with an increase in nitrogen rate. Increase in P level resulted in a decrease in fat content. The overall findings confirm that combinations of the higher levels of N and P result in a decrease in fat content. The variation in the metabolite nutrients and mineral nutrient values may be due to differences in age of the leaves or positions and possibly due to different stages of maturity of leaves. The second experiment was conducted in the field at the research farm. The aim was to evaluate the effect of leaf age/position on nutrient distribution of moringa. The seeds were sown in black polythene bags at a depth of 2 cm. The bags were filled with a mixture of 1 part of soil, 2 parts of pine bark: and 1 part of manure. The seedlings were transplanted into the field when they reached the height of 30cm. Plants were laid-out as a CRD design with 5 replications. Three leaf positions, upper, middle and basal leaves, were used as treatments to determine the nutrient variation within a parent plant. Leaves of each position were harvested separately, washed with tap water and air-dried in shade condition. The dried leaves were analysed for metabolite and mineral content. The Association of official agricultural chemists (AOAC) methods were used to determine protein, fat, fibre, and ash. Atomic absorption spectrometry (AAS) technique was used to analyse minerals v such as iron, zinc, copper, manganese and macro-minerals such as calcium, magnesium, potassium, sodium and phosphorus. The study showed that ash, fat, NDF and ADF contents were significantly higher in the basal leaves as compared to that in the middle and upper leaves. However, moisture and crude protein contents were significantly higher in the upper leaves compared to both in the middle and basal leaves. The basal leaves accumulated significantly higher Ca, Mg, K, Na and Mn contents. The concentrations of P, Zn, Cu and Fe were, on the other hand, significantly higher in the younger leaves compared to that in the middle and basal leaves. It can be concluded that the upper (younger) leaves contain enough nutrition to satisfy the dietary requirements. In addition, these leaves have low levels of oxalate, cyanide and nitrate, which can cause health problems. To determine the effect of drying method on nutrition content of moringa leaves, three drying methods (shade-, sun- and oven-drying methods) were applied as treatments. Moringa plants were grown at the Research Farm of the University of Fort Hare, Alice campus. The leaves were harvested, thoroughly mixed, washed with tap water and put into 15 brown paper bags. The 15 samples (paper bags) were distributed to the three drying treatments (each treatment replicated 5 times). The dried samples were analysed for metabolites and mineral content as per AOAC and AAS methods, respectively. The study showed that shade-drying method retained higher metabolites. Thus, this study recommends the shade-drying method in preserving moringa leaves.
- Full Text:
- Date Issued: 2019
Effects of pre-slaughter stress, sex and breed on blood stress indicators, heat shock proteins, glycolytic potential and lamb quality
- Authors: Stempa, Thuthuzelwa
- Date: 2019
- Subjects: Animal welfare , Meat--Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15376 , vital:40402
- Description: The main objective of this study was to determine the effects of pre-slaughter stress (transportation distance and lairage duration), sex and breed on blood stress indicators, heat shock proteins, post-mortem muscle metabolites (glycogen, glucose, glucose-6-phosphate and lactate), glycolytic potential and meat quality attributes from lambs slaughtered at a commercial abattoir. The study was conducted in a high-throughput commercial abattoir in the Buffalo City local municipality of the Eastern Cape Province, South Africa. A total of a hundred eight-month old Dorper and Merino lambs, both male and female, were used in the study. Blood samples for the analysis of glucose and lactate levels were collected using 10.0 mL disposable Becton Dickinson vacutainer tubes treated with fluoride oxalate (grey top) whereas those for determination of cortisol and heat shock protein 70 (HSPA1A) levels were collected using plasma separating vacutainer tubes (SSTTMII, gold top), and those for analysis of creatine kinase and lactate dehydrogenase were collected using 10.0 ml vacutainer tubes treated with Ethylenediaminetetraacetic acid (EDTA). Meat samples (~50 g) for the measurement of post-mortem energy metabolites (glycogen, lactate glucose-6-phosphate and glucose content) were collected from the Muscularis longimissius thoracis et lumborum (LTL) of each carcass ~30 minutes after slaughter and immediately frozen in liquid nitrogen (-196 oC) to prevent further glycolysis. Cold carcass weight (CCW), warm carcass weight (WCW) and carcass fatness (CF) was measured. Meat pH and temperature were measured at iii 45 minutes (initial pH), 6 hours and 24 hours ultimate pH (pHu) post-mortem. Meat colour coordinates [lightness (L*), redness (a*), yellowness (b*), hue angle (H*), chroma (C*)] were also measured 24 hours after slaughter. Furthermore, thawing loss (TL%), cooking loss (CL%) and warner braztler shear force (WBSF) was measured in the LTL 7 days post slaughter. Breed had a significant effect on plasma HSPA1A, plasma lactate, WCW, CCW, L*, muscle glycogen and WBSF. Sex had a significant effect on plasma HSPA1A and pHu. Pearson‘s correlations showed that meat muscle glycogen was positively correlated to glycolytic potential (P<0.001; r=0.63) and initial pH (P<0.05, r=0.20). Muscle lactate was positively correlated to muscle glucose (P<0.01, r=0.30) and glycolytic potential (P<0.001, r=0.79). A positive correlation was shown between muscle glucose and glycolytic potential (P<0.05, r=0.23). The level of LDH was affected by the distance travelled by lambs prior to slaughter. Lairage duration did not affect the levels of CK and LDH. Principal Component Analysis showed a relationship between distance travelled and CK and LDH; and that CK and LDH also influenced the quality of meat from lambs. With respect to sex and breed, the results indicate that female and Dorper were more stressed than male and Merino respectively. Muscle glycolytic potential and post-mortem metabolites have an impact on the quality of meat produced and the Merino had higher muscle glycogen levels at slaughter; hence they produced better meat quality compared to the Dorper. Moreover, no associations were seen between pHu and blood stress indicators. These results indicate that blood stress indicators at exsanguination cannot be used as useful indicators of dark cutting condition in lamb. A relationship between pHu, muscle glycogen and glycolytic potential was established and thus meat pHu can be used as a reliable indicator of tenderness in lamb.
- Full Text:
- Date Issued: 2019
- Authors: Stempa, Thuthuzelwa
- Date: 2019
- Subjects: Animal welfare , Meat--Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15376 , vital:40402
- Description: The main objective of this study was to determine the effects of pre-slaughter stress (transportation distance and lairage duration), sex and breed on blood stress indicators, heat shock proteins, post-mortem muscle metabolites (glycogen, glucose, glucose-6-phosphate and lactate), glycolytic potential and meat quality attributes from lambs slaughtered at a commercial abattoir. The study was conducted in a high-throughput commercial abattoir in the Buffalo City local municipality of the Eastern Cape Province, South Africa. A total of a hundred eight-month old Dorper and Merino lambs, both male and female, were used in the study. Blood samples for the analysis of glucose and lactate levels were collected using 10.0 mL disposable Becton Dickinson vacutainer tubes treated with fluoride oxalate (grey top) whereas those for determination of cortisol and heat shock protein 70 (HSPA1A) levels were collected using plasma separating vacutainer tubes (SSTTMII, gold top), and those for analysis of creatine kinase and lactate dehydrogenase were collected using 10.0 ml vacutainer tubes treated with Ethylenediaminetetraacetic acid (EDTA). Meat samples (~50 g) for the measurement of post-mortem energy metabolites (glycogen, lactate glucose-6-phosphate and glucose content) were collected from the Muscularis longimissius thoracis et lumborum (LTL) of each carcass ~30 minutes after slaughter and immediately frozen in liquid nitrogen (-196 oC) to prevent further glycolysis. Cold carcass weight (CCW), warm carcass weight (WCW) and carcass fatness (CF) was measured. Meat pH and temperature were measured at iii 45 minutes (initial pH), 6 hours and 24 hours ultimate pH (pHu) post-mortem. Meat colour coordinates [lightness (L*), redness (a*), yellowness (b*), hue angle (H*), chroma (C*)] were also measured 24 hours after slaughter. Furthermore, thawing loss (TL%), cooking loss (CL%) and warner braztler shear force (WBSF) was measured in the LTL 7 days post slaughter. Breed had a significant effect on plasma HSPA1A, plasma lactate, WCW, CCW, L*, muscle glycogen and WBSF. Sex had a significant effect on plasma HSPA1A and pHu. Pearson‘s correlations showed that meat muscle glycogen was positively correlated to glycolytic potential (P<0.001; r=0.63) and initial pH (P<0.05, r=0.20). Muscle lactate was positively correlated to muscle glucose (P<0.01, r=0.30) and glycolytic potential (P<0.001, r=0.79). A positive correlation was shown between muscle glucose and glycolytic potential (P<0.05, r=0.23). The level of LDH was affected by the distance travelled by lambs prior to slaughter. Lairage duration did not affect the levels of CK and LDH. Principal Component Analysis showed a relationship between distance travelled and CK and LDH; and that CK and LDH also influenced the quality of meat from lambs. With respect to sex and breed, the results indicate that female and Dorper were more stressed than male and Merino respectively. Muscle glycolytic potential and post-mortem metabolites have an impact on the quality of meat produced and the Merino had higher muscle glycogen levels at slaughter; hence they produced better meat quality compared to the Dorper. Moreover, no associations were seen between pHu and blood stress indicators. These results indicate that blood stress indicators at exsanguination cannot be used as useful indicators of dark cutting condition in lamb. A relationship between pHu, muscle glycogen and glycolytic potential was established and thus meat pHu can be used as a reliable indicator of tenderness in lamb.
- Full Text:
- Date Issued: 2019
Efficacy, acceptability and feasibility of mhealth technology in promoting adherence to anti-diabetic therapy and glycaemic control among diabetic patients in Eastern Cape, South Africa”
- Authors: Owolabi, Eyitayo Omolara
- Date: 2019
- Subjects: Diabetes
- Language: English
- Type: Thesis , Doctoral , PhD (Nursing)
- Identifier: http://hdl.handle.net/10353/16792 , vital:40774
- Description: Background: Diabetes mellitus is a disease of a significant public health concern and a leading cause of death and disability worldwide. In Africa, South Africa ranks second among countries with the highest burden of diabetes, and with a poor level of glycaemic control. mHealth technology is an innovative and cost-effective measure of promoting health and the use of text messaging for fostering health is evolving. In South Africa, there is hardly any study involving the use of mobile health technology, including text messaging for promoting health among diabetic patients. Purpose: The aim of this study was to determine the efficacy, feasibility and acceptability of mHealth in promoting adherence and glycaemic control among diabetic patients in resource-poor settings of the Eastern Cape Province of South Africa. Also, the study assessed the impact of text messaging on knowledge, selfmanagement behaviour, self-efficacy and health-related quality of life. Methodology: The study adopted a multi-centre, two-arm, parallel, randomised controlled trial design. Participants were randomly assigned to the intervention (n=108) and control arm (n=108). Participants’ socio-demographic information was obtained using the widely validated WHO STEPwise questionnaire, and a selfdeveloped questionnaire, including previously validated measurement scales were used to obtain information on adherence, self-management behaviour, self-efficacy and health-related quality of life. Participants in the intervention arm received daily text messages related to diabetes management and care for six months. Data were collected at baseline and six months post-intervention. Blood glucose, blood pressure and anthropometric measurements followed standard procedure. Mixed-model analysis was used to assess the impact of the SMS on random blood glucose while xi | P a g e linear and bivariate logistic regression were used to assess for effect on other clinical outcomes. Results: The mean age of the participants was 60.64 (SD± 11.58) years. The majority of the study participants had secondary level of education (95.3%) and earned 1500 to 14200 Rand per month (67.7%). For both the intervention and the control group, majority never used tobacco (98.10% vs 94.40%) or alcohol (88.00% vs 87.00%). Both arms of the study showed improvement in the primary outcome (blood glucose level), with no significant difference, the mean adjusted difference in blood glucose from baseline to six months post-intervention was 0.26 (-0.81 to 1.32), p=0.634. Also, the intervention did not have a significant effect on the secondary outcomes (knowledge, medication adherence, dietary adherence, adherence to physical activity, healthrelated quality of life, self-management behaviour and diabetes distress). Similarly, the intervention did not have any significant effect on secondary clinical outcomes such as weight (p=0.654), body mass index (p=0.439), systolic (p=0.610) and diastolic blood pressure (p=0.535). An overwhelming majority of the participants (90.74%) were pleased with the intervention and felt it was helpful. Of those who took part in the intervention, 91% completed the follow-up study after six months. Conclusion: The use of SMS is a highly acceptable and feasible adjunct to standard clinical care in the promotion of health among diabetic patients in this study setting. Although there was a little improvement, the efficacy of a unidirectional text messaging in promoting health outcomes in this study setting is still doubt
- Full Text:
- Date Issued: 2019
- Authors: Owolabi, Eyitayo Omolara
- Date: 2019
- Subjects: Diabetes
- Language: English
- Type: Thesis , Doctoral , PhD (Nursing)
- Identifier: http://hdl.handle.net/10353/16792 , vital:40774
- Description: Background: Diabetes mellitus is a disease of a significant public health concern and a leading cause of death and disability worldwide. In Africa, South Africa ranks second among countries with the highest burden of diabetes, and with a poor level of glycaemic control. mHealth technology is an innovative and cost-effective measure of promoting health and the use of text messaging for fostering health is evolving. In South Africa, there is hardly any study involving the use of mobile health technology, including text messaging for promoting health among diabetic patients. Purpose: The aim of this study was to determine the efficacy, feasibility and acceptability of mHealth in promoting adherence and glycaemic control among diabetic patients in resource-poor settings of the Eastern Cape Province of South Africa. Also, the study assessed the impact of text messaging on knowledge, selfmanagement behaviour, self-efficacy and health-related quality of life. Methodology: The study adopted a multi-centre, two-arm, parallel, randomised controlled trial design. Participants were randomly assigned to the intervention (n=108) and control arm (n=108). Participants’ socio-demographic information was obtained using the widely validated WHO STEPwise questionnaire, and a selfdeveloped questionnaire, including previously validated measurement scales were used to obtain information on adherence, self-management behaviour, self-efficacy and health-related quality of life. Participants in the intervention arm received daily text messages related to diabetes management and care for six months. Data were collected at baseline and six months post-intervention. Blood glucose, blood pressure and anthropometric measurements followed standard procedure. Mixed-model analysis was used to assess the impact of the SMS on random blood glucose while xi | P a g e linear and bivariate logistic regression were used to assess for effect on other clinical outcomes. Results: The mean age of the participants was 60.64 (SD± 11.58) years. The majority of the study participants had secondary level of education (95.3%) and earned 1500 to 14200 Rand per month (67.7%). For both the intervention and the control group, majority never used tobacco (98.10% vs 94.40%) or alcohol (88.00% vs 87.00%). Both arms of the study showed improvement in the primary outcome (blood glucose level), with no significant difference, the mean adjusted difference in blood glucose from baseline to six months post-intervention was 0.26 (-0.81 to 1.32), p=0.634. Also, the intervention did not have a significant effect on the secondary outcomes (knowledge, medication adherence, dietary adherence, adherence to physical activity, healthrelated quality of life, self-management behaviour and diabetes distress). Similarly, the intervention did not have any significant effect on secondary clinical outcomes such as weight (p=0.654), body mass index (p=0.439), systolic (p=0.610) and diastolic blood pressure (p=0.535). An overwhelming majority of the participants (90.74%) were pleased with the intervention and felt it was helpful. Of those who took part in the intervention, 91% completed the follow-up study after six months. Conclusion: The use of SMS is a highly acceptable and feasible adjunct to standard clinical care in the promotion of health among diabetic patients in this study setting. Although there was a little improvement, the efficacy of a unidirectional text messaging in promoting health outcomes in this study setting is still doubt
- Full Text:
- Date Issued: 2019
Efficient market hypothesis in South Africa: an analysis using the flexible form unit root test
- Authors: Nomatye, Anelisa
- Date: 2019
- Subjects: Stocks -- Prices -- South Africa , Stock exchanges -- South Africa Stocks -- South Africa Johannesburg Stock Exchange Economic indicators -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/42825 , vital:36697
- Description: An efficient stock market is characterised by prices that are reflective of all the information such that there are no opportunities for arbitrageurs. In an efficient market, it is impossible to beat the market, therefore it follows that stock prices in an efficient market should follow a random walk. This study investigates whether the Johannesburg Stock Exchange (JSE) is an efficient market using the JSE Top 40 listed stocks, thus the relevance of the EMH in the current South African market is analysed. A corerlation analysis is undertaken to find whether the individual stocks in the different sectors are correlated in their returns, or if there are any intersector correlations. This analysis showed that individual sector stocks are mostly correlated, however, the individual sector stocks do not show a relationship with common sectors. The data used is monthly data of the individual stocks from 31 January 1999 to 30 June 2018. The study takes into consideration that the period is post the Asian Contagion and during the dot.com bubble. Also considered is the Global Financial crisis that occurred in 2007/2008. The study period thus allows enough time for market corerction. The study utilises the conventional unit root tests; the augmented Dickey-Fuller (ADF), Phillips- Perron (PP) and the Kwiatkowski–Phillips–Schmidt–Shin (KPSS) tests. Also utilised are modified unit root tests of Elliot, Rothenburg and Stock (ERS) (1996) as well as Ng and Perron (2001). Due to criticisms of the initially utilised unit roots, the nonlinear test of Kapetanois et al. (2003) and the Flexible Fourier form (FFF) is employed. Based on the empirical analysis, the study demonstrates that although the studies received conflicting evidence the FFF demonstrates the most “power” of the tests, thus is deemed to provide more accurate results. This test provided evidence of stationarity in the JSE market, thus implying inefficiency. The results were different for only two of the forty stocks, namely, Shoprite and Bidvest which implied efficiency. The study thus found that the EMH is not relevant to the current South African market and other theories should be considered in analysing the market. This also provides a case for behavioural finance to be analysed, as the assumption that all investors are rational is questioned.
- Full Text:
- Date Issued: 2019
- Authors: Nomatye, Anelisa
- Date: 2019
- Subjects: Stocks -- Prices -- South Africa , Stock exchanges -- South Africa Stocks -- South Africa Johannesburg Stock Exchange Economic indicators -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/42825 , vital:36697
- Description: An efficient stock market is characterised by prices that are reflective of all the information such that there are no opportunities for arbitrageurs. In an efficient market, it is impossible to beat the market, therefore it follows that stock prices in an efficient market should follow a random walk. This study investigates whether the Johannesburg Stock Exchange (JSE) is an efficient market using the JSE Top 40 listed stocks, thus the relevance of the EMH in the current South African market is analysed. A corerlation analysis is undertaken to find whether the individual stocks in the different sectors are correlated in their returns, or if there are any intersector correlations. This analysis showed that individual sector stocks are mostly correlated, however, the individual sector stocks do not show a relationship with common sectors. The data used is monthly data of the individual stocks from 31 January 1999 to 30 June 2018. The study takes into consideration that the period is post the Asian Contagion and during the dot.com bubble. Also considered is the Global Financial crisis that occurred in 2007/2008. The study period thus allows enough time for market corerction. The study utilises the conventional unit root tests; the augmented Dickey-Fuller (ADF), Phillips- Perron (PP) and the Kwiatkowski–Phillips–Schmidt–Shin (KPSS) tests. Also utilised are modified unit root tests of Elliot, Rothenburg and Stock (ERS) (1996) as well as Ng and Perron (2001). Due to criticisms of the initially utilised unit roots, the nonlinear test of Kapetanois et al. (2003) and the Flexible Fourier form (FFF) is employed. Based on the empirical analysis, the study demonstrates that although the studies received conflicting evidence the FFF demonstrates the most “power” of the tests, thus is deemed to provide more accurate results. This test provided evidence of stationarity in the JSE market, thus implying inefficiency. The results were different for only two of the forty stocks, namely, Shoprite and Bidvest which implied efficiency. The study thus found that the EMH is not relevant to the current South African market and other theories should be considered in analysing the market. This also provides a case for behavioural finance to be analysed, as the assumption that all investors are rational is questioned.
- Full Text:
- Date Issued: 2019
Efficient market hypothesis with structural breaks: evidence from BRICS stock markets
- Authors: Guduza, Sinazo
- Date: 2019
- Subjects: Stock exchanges , Investment analysis Developing countries -- Economic conditions
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/42342 , vital:36647
- Description: The study is an examination of weak form market efficiency (EMH) in BRICS equity markets using weekly data spanning from 2005 to 2018. The study makes use linear as well as nonlinear unit rot tests, that is, the ADF and KSS tests respectively. For more robust results, the study uses the Integer Flexible Fourier Function (IFFF) and the Fractional Frequency Flexible Fourier Function (FFFFF) to account for smooth structural breaks. The study investigates the full sample period and splits the empirical data into three sub-samples corresponding to the period succeeding the global financial crisis, the BRICS summits and the BRICS Development Bank (BDB). This study, to the best of our knowledge, is the first to investigate the efficiency in the BRICS stock markets using a combination of the specified series of unit root tests. Moreover, there are no prior studies that have examined these markets for the sub-samples mentioned above. Our empirical results point us to convincing evidence of weak form inefficiency as the majority of the results reject the null hypothesis of a unit root.
- Full Text:
- Date Issued: 2019
- Authors: Guduza, Sinazo
- Date: 2019
- Subjects: Stock exchanges , Investment analysis Developing countries -- Economic conditions
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/42342 , vital:36647
- Description: The study is an examination of weak form market efficiency (EMH) in BRICS equity markets using weekly data spanning from 2005 to 2018. The study makes use linear as well as nonlinear unit rot tests, that is, the ADF and KSS tests respectively. For more robust results, the study uses the Integer Flexible Fourier Function (IFFF) and the Fractional Frequency Flexible Fourier Function (FFFFF) to account for smooth structural breaks. The study investigates the full sample period and splits the empirical data into three sub-samples corresponding to the period succeeding the global financial crisis, the BRICS summits and the BRICS Development Bank (BDB). This study, to the best of our knowledge, is the first to investigate the efficiency in the BRICS stock markets using a combination of the specified series of unit root tests. Moreover, there are no prior studies that have examined these markets for the sub-samples mentioned above. Our empirical results point us to convincing evidence of weak form inefficiency as the majority of the results reject the null hypothesis of a unit root.
- Full Text:
- Date Issued: 2019
Eight decades of invasion by Chromolaena odorata (Asteraceae) and its biological control in West Africa: the story so far
- Aigbedion-Atalor, Pascal O, Adom, Medetissi, Day, Michael D, Uyi, Osariyekemwen O, Egbon, Ikponmwosa N, Idemudia, I, Igbinosa, Igho B, Paterson, Iain D, Braimah, Haruna, Wilson, David D, Zachariades, Costas
- Authors: Aigbedion-Atalor, Pascal O , Adom, Medetissi , Day, Michael D , Uyi, Osariyekemwen O , Egbon, Ikponmwosa N , Idemudia, I , Igbinosa, Igho B , Paterson, Iain D , Braimah, Haruna , Wilson, David D , Zachariades, Costas
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417450 , vital:71454 , xlink:href="https://doi.org/10.1080/09583157.2019.1670782"
- Description: Chromolaena odorata (L.) R.M. King and H. Robinson (Asteraceae) is a perennial weedy shrub of neotropical origin and a serious biotic threat in its invasive range. The Asian-West Africa (AWA) biotype of C. odorata present in West Africa is both morphologically and genetically different from the southern African (SA) biotype. The AWA biotype was first introduced into Nigeria in the late 1930s and rapidly spread across West Africa. Currently, 12 of the 16 countries in West Africa have been invaded, with significant negative effects on indigenous flora and fauna. However, locals in West Africa have found several uses for the weed. As chemical, physical and other conventional methods were unsustainable, costly and largely ineffective, three biological control agents, Apion brunneonigrum (Coleoptera: Brentidae), Pareuchaetes pseudoinsulata (Lepidoptera: Erebidae) and Cecidochares connexa (Diptera: Tephritidae), have been released in West Africa between the 1970s and the early 2000s. However, only C. connexa and P. pseudoinsulata established, contributing to the control of the weed, in six and four countries in West Africa respectively. Limited research funding, the absence of post-release evaluations of the established agents, and the ‘conflict of interest’ status of C. odorata (i.e. being beneficial for local use but damaging to ecosystem services and agriculture), are serious factors deterring the overall biological control effort. Here, using historical records and field surveys, we examine the invasion history, spread, impacts, and management of C. odorata in West Africa and make recommendations for the sustainable management of C. odorata in the region.
- Full Text:
- Date Issued: 2019
- Authors: Aigbedion-Atalor, Pascal O , Adom, Medetissi , Day, Michael D , Uyi, Osariyekemwen O , Egbon, Ikponmwosa N , Idemudia, I , Igbinosa, Igho B , Paterson, Iain D , Braimah, Haruna , Wilson, David D , Zachariades, Costas
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417450 , vital:71454 , xlink:href="https://doi.org/10.1080/09583157.2019.1670782"
- Description: Chromolaena odorata (L.) R.M. King and H. Robinson (Asteraceae) is a perennial weedy shrub of neotropical origin and a serious biotic threat in its invasive range. The Asian-West Africa (AWA) biotype of C. odorata present in West Africa is both morphologically and genetically different from the southern African (SA) biotype. The AWA biotype was first introduced into Nigeria in the late 1930s and rapidly spread across West Africa. Currently, 12 of the 16 countries in West Africa have been invaded, with significant negative effects on indigenous flora and fauna. However, locals in West Africa have found several uses for the weed. As chemical, physical and other conventional methods were unsustainable, costly and largely ineffective, three biological control agents, Apion brunneonigrum (Coleoptera: Brentidae), Pareuchaetes pseudoinsulata (Lepidoptera: Erebidae) and Cecidochares connexa (Diptera: Tephritidae), have been released in West Africa between the 1970s and the early 2000s. However, only C. connexa and P. pseudoinsulata established, contributing to the control of the weed, in six and four countries in West Africa respectively. Limited research funding, the absence of post-release evaluations of the established agents, and the ‘conflict of interest’ status of C. odorata (i.e. being beneficial for local use but damaging to ecosystem services and agriculture), are serious factors deterring the overall biological control effort. Here, using historical records and field surveys, we examine the invasion history, spread, impacts, and management of C. odorata in West Africa and make recommendations for the sustainable management of C. odorata in the region.
- Full Text:
- Date Issued: 2019
Ekhakhamela
- Authors: Machi, Nolwazi Fortunate
- Date: 2019
- Subjects: Xhosa poetry
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/76332 , vital:30549
- Description: My collection of isiZulu poems is based on my rural and traditional upbringing. It draws on language and customs which have shaped and defined me as a woman born in the South of KwaZulu-Natal. I write about how I have to conform to both a rural life and an urban one that forms my second world. I find myself having to switch between these lives, which benefits me a lot, and I feel a responsibility to bring hope to young people especially from the rural side, that nothing is wrong with being who and where they are. My writing is influenced by authors such as Nazim Hikmet, Mafika Gwala, and Mazisi Kunene who encourages black writers to write about their own customs and stories rather than embracing ‘western civilization’ and foreign languages. I also like the contemporary subjects and the humour in Dr Nakanjani Sibiya’s work.
- Full Text:
- Date Issued: 2019
- Authors: Machi, Nolwazi Fortunate
- Date: 2019
- Subjects: Xhosa poetry
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/76332 , vital:30549
- Description: My collection of isiZulu poems is based on my rural and traditional upbringing. It draws on language and customs which have shaped and defined me as a woman born in the South of KwaZulu-Natal. I write about how I have to conform to both a rural life and an urban one that forms my second world. I find myself having to switch between these lives, which benefits me a lot, and I feel a responsibility to bring hope to young people especially from the rural side, that nothing is wrong with being who and where they are. My writing is influenced by authors such as Nazim Hikmet, Mafika Gwala, and Mazisi Kunene who encourages black writers to write about their own customs and stories rather than embracing ‘western civilization’ and foreign languages. I also like the contemporary subjects and the humour in Dr Nakanjani Sibiya’s work.
- Full Text:
- Date Issued: 2019
Elasticity of the South African economy towards portfolio investments in BRICS countries
- Authors: Taonezvi, Lovemore
- Date: 2019
- Subjects: Economic development -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/44537 , vital:38141
- Description: The emerging economies of Brazil, Russia, India, and China (BRIC) have been experiencing high growth rates since the turn of the millennium, whereas economic growth has been elusive in South Africa. As the newest member of BRICS, South Africa is expected to economically benefit through, amongst others, increases in capital flows, foreign investments by local firms, and increases in trade. Such benefits are anticipated to propel the country’s economic growth, thereby helping it to tackle its chronic problems of high unemployment, poverty, and economic inequality. The inclusion of South Africa in BRICS has, however, been viewed by critics as erroneous, since the country has, inter alia, poor economic growth; a small economy and population; and political instability. While foreign portfolio investment (FPI) inflows to South Africa have surged in recent years, economic growth has remained lacklustre. These flows have also faced sudden reversals, especially during the financial crisis of 2007-2009. With the potential to leverage its growth from intra-BRICS FPI inflows, it becomes of paramount significance for policymakers to have knowledge of the South African economy’s responsiveness to such inflows. With a theoretical framework based on the endogenous growth model, an augmented Cobb-Douglas production function was extended in this thesis in order to study the relationship between BRICS growth and intra-BRICS FPI in a dynamic panel data generalised method of moments (GMM) context. Similarly, the South African economy’s elasticity towards intraBRICS FPI was estimated. Vector autoregressive (VAR) analysis was used to evaluate the responsiveness of South Africa’s economy to an innovative shock to intra-BRICS FPI. Annual and quarterly data for the period 2000-2016 were used in panel data and VAR analysis, respectively. It was found that intra-BRICS FPI flows have a positive and statistically significant relationship with BRICS growth, while the elasticity of the South African economy to these flows is estimated at 0.007. Additionally, the efficiency and accessibility dimensions of financial market development do not assist FPI in promoting growth in BRICS, while financial market depth does. South Africa’s BRICS membership has a positive effect on its own growth, while for other BRICS nations, this membership is negative and insignificant. Credit rating downgrades have a negative and insignificant impact on economic growth, while the negative impact for inflation, government expenditure, and total labour employment is significant. Conversely, gross capital formation and trade openness have a positive and significant relationship with BRICS growth. The study also determined that a unit shock on intra-BRICS FPI resulted in negative fluctuations of South Africa’s economy within the first eight quarters before being positive and mostly constant thereafter. By supplementing domestic savings and facilitating the international integration of domestic financial markets, FPI promotes growth in BRICS. The short-term, ease of reversibility, and speculative nature of FPI are amongst some of the reasons for its destabilising effect on South Africa’s economy. Furthermore, inflation is a key determinant of FPI inflows to South Africa. Additional BRIC cooperation in FPI and trade; increased investments in domestic capital; reductions of inflation and corruption; investments in education and skills development; and stock market reforms are some of the recommendations for BRIC, and South Africa in particular. South Africa can consider prudential use of a mix of capital account controls, as well as fiscal and monetary policies to cushion its economy from FPI shocks in the short- to medium-term.
- Full Text:
- Date Issued: 2019
- Authors: Taonezvi, Lovemore
- Date: 2019
- Subjects: Economic development -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/44537 , vital:38141
- Description: The emerging economies of Brazil, Russia, India, and China (BRIC) have been experiencing high growth rates since the turn of the millennium, whereas economic growth has been elusive in South Africa. As the newest member of BRICS, South Africa is expected to economically benefit through, amongst others, increases in capital flows, foreign investments by local firms, and increases in trade. Such benefits are anticipated to propel the country’s economic growth, thereby helping it to tackle its chronic problems of high unemployment, poverty, and economic inequality. The inclusion of South Africa in BRICS has, however, been viewed by critics as erroneous, since the country has, inter alia, poor economic growth; a small economy and population; and political instability. While foreign portfolio investment (FPI) inflows to South Africa have surged in recent years, economic growth has remained lacklustre. These flows have also faced sudden reversals, especially during the financial crisis of 2007-2009. With the potential to leverage its growth from intra-BRICS FPI inflows, it becomes of paramount significance for policymakers to have knowledge of the South African economy’s responsiveness to such inflows. With a theoretical framework based on the endogenous growth model, an augmented Cobb-Douglas production function was extended in this thesis in order to study the relationship between BRICS growth and intra-BRICS FPI in a dynamic panel data generalised method of moments (GMM) context. Similarly, the South African economy’s elasticity towards intraBRICS FPI was estimated. Vector autoregressive (VAR) analysis was used to evaluate the responsiveness of South Africa’s economy to an innovative shock to intra-BRICS FPI. Annual and quarterly data for the period 2000-2016 were used in panel data and VAR analysis, respectively. It was found that intra-BRICS FPI flows have a positive and statistically significant relationship with BRICS growth, while the elasticity of the South African economy to these flows is estimated at 0.007. Additionally, the efficiency and accessibility dimensions of financial market development do not assist FPI in promoting growth in BRICS, while financial market depth does. South Africa’s BRICS membership has a positive effect on its own growth, while for other BRICS nations, this membership is negative and insignificant. Credit rating downgrades have a negative and insignificant impact on economic growth, while the negative impact for inflation, government expenditure, and total labour employment is significant. Conversely, gross capital formation and trade openness have a positive and significant relationship with BRICS growth. The study also determined that a unit shock on intra-BRICS FPI resulted in negative fluctuations of South Africa’s economy within the first eight quarters before being positive and mostly constant thereafter. By supplementing domestic savings and facilitating the international integration of domestic financial markets, FPI promotes growth in BRICS. The short-term, ease of reversibility, and speculative nature of FPI are amongst some of the reasons for its destabilising effect on South Africa’s economy. Furthermore, inflation is a key determinant of FPI inflows to South Africa. Additional BRIC cooperation in FPI and trade; increased investments in domestic capital; reductions of inflation and corruption; investments in education and skills development; and stock market reforms are some of the recommendations for BRIC, and South Africa in particular. South Africa can consider prudential use of a mix of capital account controls, as well as fiscal and monetary policies to cushion its economy from FPI shocks in the short- to medium-term.
- Full Text:
- Date Issued: 2019
Elections as Drivers of Political Instability in Africa: A Case Study of Lesotho
- Authors: Moorosi, Mantsoaki
- Date: 2019
- Subjects: Elections Political parties -- Lesotho
- Language: English
- Type: Thesis , Masters , MSoc (Political Science)
- Identifier: http://hdl.handle.net/10353/16462 , vital:40722
- Description: The study sets out to investigate elections as drivers to political instability in Africa, using Lesotho as a case study from 2012 to 2017. It employs primary and secondary sources of data. The period is of interest for two reasons. Firstly, the continuing instability post three successive free and fair elections, and secondly, the advent of Coalition Governments. The structure adheres to two theoretical frameworks namely, a) Huntington’s two turn-over test and, b) Karl’s Fallacy of Electoralism. In order to investigate how elections could or could not be drivers to political instability, the researcher looked at the different forms of political instability in Lesotho. These include attempted coup d’état, assassinations and violation of territorial sovereignty. The later form being peculiar to the period under study as the other forms had occurred at some stage through the political history of this country. It further asserts uncertainty of hung Parliament and politicised institutions as attributes to the recurrence of political instability. It concludes that Lesotho is a deviant case from the two turn over test. The scope of the study supports the fallacy of electoralism. Several recommendations have been presented. These include that Government of Lesotho should amend the Constitution on the functions and powers of the King, Politicians should implement the promises they made to the electorates during campaigns, and regulate or abolish floor crossing in Parliament amongst others.
- Full Text:
- Date Issued: 2019
- Authors: Moorosi, Mantsoaki
- Date: 2019
- Subjects: Elections Political parties -- Lesotho
- Language: English
- Type: Thesis , Masters , MSoc (Political Science)
- Identifier: http://hdl.handle.net/10353/16462 , vital:40722
- Description: The study sets out to investigate elections as drivers to political instability in Africa, using Lesotho as a case study from 2012 to 2017. It employs primary and secondary sources of data. The period is of interest for two reasons. Firstly, the continuing instability post three successive free and fair elections, and secondly, the advent of Coalition Governments. The structure adheres to two theoretical frameworks namely, a) Huntington’s two turn-over test and, b) Karl’s Fallacy of Electoralism. In order to investigate how elections could or could not be drivers to political instability, the researcher looked at the different forms of political instability in Lesotho. These include attempted coup d’état, assassinations and violation of territorial sovereignty. The later form being peculiar to the period under study as the other forms had occurred at some stage through the political history of this country. It further asserts uncertainty of hung Parliament and politicised institutions as attributes to the recurrence of political instability. It concludes that Lesotho is a deviant case from the two turn over test. The scope of the study supports the fallacy of electoralism. Several recommendations have been presented. These include that Government of Lesotho should amend the Constitution on the functions and powers of the King, Politicians should implement the promises they made to the electorates during campaigns, and regulate or abolish floor crossing in Parliament amongst others.
- Full Text:
- Date Issued: 2019
Electric cars: their carbon implications and adoption in South Africa
- Authors: Moeletsi, Mokhele Edmond
- Date: 2019
- Subjects: Electric vehicles -- Economic aspects , Electric vehicles -- South Africa Power resources -- South Africa Sustainable development -- South Africa Energy policy -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/41886 , vital:36606
- Description: Climate change is a reality that is starting to have an impact on society through decreased agricultural production and increased extreme weather events, resulting to worldwide disasters. It is caused by human activities that release greenhouse gas emissions into the atmosphere. One of the key areas of concern is the mobility sector which accounts for around 20% of the total energy use, with a GHG footprint of close to 14% of the global emissions. International organisations are concerned about the elevating GHG emissions resulting from the increasing internal combustion engine vehicles, leading to the recent wave in electrifying the vehicles which presents many of advantages as well as major constraints. This study used the quantitative research approach to investigate the possible benefits of electric vehicles to our environment in the future. The projections of vehicle population size were estimated using three cases, and the electric vehicle penetration into the market by 2030 was investigated with four different scenarios. Further research was done to investigate the possible barriers present in the South African market that impede the adoption of electric vehicles. The results showed that the projection of the business-as-usual case, coupled with mitigation scenarios, present a better option for mitigation. The worst case of exponential increases in vehicle population does not present any GHG emissions moderation hope for any of the mitigation scenarios used in the study. The other case shows high mitigation potential, but it leads to a case of economic decline where the numbers of vehicles are decreasing with time. The findings of the study on barriers to adoption of electric vehicles in the market highlighted the high purchase price, high battery price and high likelihood for owning a secondary vehicle based on the current circumstances, as the main barriers that the respondents in the Gauteng Province found to be unattractive. But generally the willingness to buy electric vehicles was high for the majority of the factors that were presented. With these perceived positive opinions by the respondents, it is down to government and private companies to provide an environment conducive to changed opinions conducive for the consumers. This relates to advancing the technology and providing policy support for the accelerated adoption of electric vehicles.
- Full Text:
- Date Issued: 2019
- Authors: Moeletsi, Mokhele Edmond
- Date: 2019
- Subjects: Electric vehicles -- Economic aspects , Electric vehicles -- South Africa Power resources -- South Africa Sustainable development -- South Africa Energy policy -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/41886 , vital:36606
- Description: Climate change is a reality that is starting to have an impact on society through decreased agricultural production and increased extreme weather events, resulting to worldwide disasters. It is caused by human activities that release greenhouse gas emissions into the atmosphere. One of the key areas of concern is the mobility sector which accounts for around 20% of the total energy use, with a GHG footprint of close to 14% of the global emissions. International organisations are concerned about the elevating GHG emissions resulting from the increasing internal combustion engine vehicles, leading to the recent wave in electrifying the vehicles which presents many of advantages as well as major constraints. This study used the quantitative research approach to investigate the possible benefits of electric vehicles to our environment in the future. The projections of vehicle population size were estimated using three cases, and the electric vehicle penetration into the market by 2030 was investigated with four different scenarios. Further research was done to investigate the possible barriers present in the South African market that impede the adoption of electric vehicles. The results showed that the projection of the business-as-usual case, coupled with mitigation scenarios, present a better option for mitigation. The worst case of exponential increases in vehicle population does not present any GHG emissions moderation hope for any of the mitigation scenarios used in the study. The other case shows high mitigation potential, but it leads to a case of economic decline where the numbers of vehicles are decreasing with time. The findings of the study on barriers to adoption of electric vehicles in the market highlighted the high purchase price, high battery price and high likelihood for owning a secondary vehicle based on the current circumstances, as the main barriers that the respondents in the Gauteng Province found to be unattractive. But generally the willingness to buy electric vehicles was high for the majority of the factors that were presented. With these perceived positive opinions by the respondents, it is down to government and private companies to provide an environment conducive to changed opinions conducive for the consumers. This relates to advancing the technology and providing policy support for the accelerated adoption of electric vehicles.
- Full Text:
- Date Issued: 2019
Electrical, photo-thermal and mechanical degradation analysis of degraded single junction amorphous silicon solar modules
- Osayemwenre, Gilbert Omorodion
- Authors: Osayemwenre, Gilbert Omorodion
- Date: 2019
- Subjects: Solar cells Amorphous semiconductors Silicon
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15211 , vital:40204
- Description: In this present era of sustainable energy development, photovoltaic modules which are based on amorphous silicon cells have immeasurable prospects of contributing meaningfully to the energy demand of the world at large. The global consciousness of environmental safety issues has birthed the rapid demand for the photovoltaic system. However, the production increase is mainly in bulk-type crystalline (c-Si) solar cells. Thus, to meet the high demand of the market, single junction amorphous silicon (a-Si:H) solar cells production must be encouraged through active research in that regard. This could also help to improve its efficiency and reliability. There has recently been a sharp decrease in the production cost of the bulk Si solar cell, but the a-Si:H solar cell still remains the most economically viable in comparison to the other PV technologies. Companies such as Sharp are currently developing large-scale a-Si:H solar modules that can produce an efficiency of 10.5% after the long-term degradation process. To date, a-Si:H is believed to be one of the most promising thin-film PV technologies (Saito et al., 1993; Hamakawa et al., 1994). The cost of a solar PV manufacturing fell by 6% in 2014 (Santa, 2014), this is in accordance with the 2008 cost production forecast; thus, the cost record stands at 0.20 per watt, as reported by the NPD Solar publisher. Amorphous silicon (a-Si) solar modules generate more kilowatt-hour (kWh) of electricity per kilowatt (kW) than crystalline silicon or other technologies of the same capacity of installation. Furthermore, a-Si:H modules have more functional hours per day. Single junction amorphous silicon (a-Si:H) modules can function beyond the peak sun hours, and they also have a better performance on a cloudy day. vii In other words, a 1kW PV system of a-Si:H is expected to generate more electricity per year in comparison to 1kW PV from other technologies, hence there is a low energy payback time. In this study, commercially available single junction amorphous silicon modules were bought from a local market and they were immediately deployed outdoors. The initial reading of the modules, which served as baseline reading, showed an average of 25% decrease in the modules performance, therefore, there is a need for a long term monitoring process to obtain the best and worst performing modules. Measuring the performance parameters of these PV modules under real sun light (IV) provides a better degradation assessment. This conventional assessment cannot provide an in-depth insight responsible for the variation and degradation of the performance parameters. More obscured parameters like recombination current and ideality factor were obtained from the dark IV measurements. However, this is still superficial in a way. The intrinsic parameters were obtained from scanning probe microscopy (SPM) and CV measurements. The study focuses on the degradation analysis of a-Si:H due to an increase in defect density. A rise in the defect concentration is a huge problem because it causes long-term solar cell degradation, which increases the recombination current and decreases the conversion efficiency. Furthermore, it decreases the photo-generating current and reduces the effective efficiency of the solar device. In other words, the electrical output decreases. This research investigates the reduction in a-Si:H modules’ maximum power, and correlates these with a hot spot formation. A PVPM IV tracer was used for the outdoor characterisation of the module’s temperature profile, while the IR camera was used to analyse the hot spot centre. A four probe IV/CV from NMU was used for the indoor assessment of smaller samples cleaved from both the affected and non-affected regions to characterise the electrical variations across the module viii samples. To be precise, in this study, a naturally degraded single junction amorphous silicon module was delaminated and its mechanical properties were analysed and correlated with the contact potential from a Kelvin probe force microscopy (KPFM).
- Full Text:
- Date Issued: 2019
- Authors: Osayemwenre, Gilbert Omorodion
- Date: 2019
- Subjects: Solar cells Amorphous semiconductors Silicon
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15211 , vital:40204
- Description: In this present era of sustainable energy development, photovoltaic modules which are based on amorphous silicon cells have immeasurable prospects of contributing meaningfully to the energy demand of the world at large. The global consciousness of environmental safety issues has birthed the rapid demand for the photovoltaic system. However, the production increase is mainly in bulk-type crystalline (c-Si) solar cells. Thus, to meet the high demand of the market, single junction amorphous silicon (a-Si:H) solar cells production must be encouraged through active research in that regard. This could also help to improve its efficiency and reliability. There has recently been a sharp decrease in the production cost of the bulk Si solar cell, but the a-Si:H solar cell still remains the most economically viable in comparison to the other PV technologies. Companies such as Sharp are currently developing large-scale a-Si:H solar modules that can produce an efficiency of 10.5% after the long-term degradation process. To date, a-Si:H is believed to be one of the most promising thin-film PV technologies (Saito et al., 1993; Hamakawa et al., 1994). The cost of a solar PV manufacturing fell by 6% in 2014 (Santa, 2014), this is in accordance with the 2008 cost production forecast; thus, the cost record stands at 0.20 per watt, as reported by the NPD Solar publisher. Amorphous silicon (a-Si) solar modules generate more kilowatt-hour (kWh) of electricity per kilowatt (kW) than crystalline silicon or other technologies of the same capacity of installation. Furthermore, a-Si:H modules have more functional hours per day. Single junction amorphous silicon (a-Si:H) modules can function beyond the peak sun hours, and they also have a better performance on a cloudy day. vii In other words, a 1kW PV system of a-Si:H is expected to generate more electricity per year in comparison to 1kW PV from other technologies, hence there is a low energy payback time. In this study, commercially available single junction amorphous silicon modules were bought from a local market and they were immediately deployed outdoors. The initial reading of the modules, which served as baseline reading, showed an average of 25% decrease in the modules performance, therefore, there is a need for a long term monitoring process to obtain the best and worst performing modules. Measuring the performance parameters of these PV modules under real sun light (IV) provides a better degradation assessment. This conventional assessment cannot provide an in-depth insight responsible for the variation and degradation of the performance parameters. More obscured parameters like recombination current and ideality factor were obtained from the dark IV measurements. However, this is still superficial in a way. The intrinsic parameters were obtained from scanning probe microscopy (SPM) and CV measurements. The study focuses on the degradation analysis of a-Si:H due to an increase in defect density. A rise in the defect concentration is a huge problem because it causes long-term solar cell degradation, which increases the recombination current and decreases the conversion efficiency. Furthermore, it decreases the photo-generating current and reduces the effective efficiency of the solar device. In other words, the electrical output decreases. This research investigates the reduction in a-Si:H modules’ maximum power, and correlates these with a hot spot formation. A PVPM IV tracer was used for the outdoor characterisation of the module’s temperature profile, while the IR camera was used to analyse the hot spot centre. A four probe IV/CV from NMU was used for the indoor assessment of smaller samples cleaved from both the affected and non-affected regions to characterise the electrical variations across the module viii samples. To be precise, in this study, a naturally degraded single junction amorphous silicon module was delaminated and its mechanical properties were analysed and correlated with the contact potential from a Kelvin probe force microscopy (KPFM).
- Full Text:
- Date Issued: 2019
Electrocatalytic activity of a push pull Co (II) phthalocyanine in the presence of graphitic carbon nitride quantum dots
- Nxele, Siphesihle R, Oluwole, David O, Nyokong, Tebello
- Authors: Nxele, Siphesihle R , Oluwole, David O , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186746 , vital:44530 , xlink:href="https://doi.org/10.1016/j.electacta.2019.134978"
- Description: This work reports for the first time on the use of a conjugate of graphitic carbon nitride quantum dots (gCNQDs) with a push-pull asymmetrical cobalt phthalocyanine (CoPc) for electrochemical sensing. The nanocomposite is immobilized on a glassy carbon electrode (GCE) surface for the use in l-cysteine electrocatalysis. The nanocomposites were characterized using techniques such as X-ray diffractometry (XRD), Fourier transform infrared (FTIR) spectroscopy, UV-vis spectroscopy, transmission electron microscopy (TEM), energy dispersive X-ray (EDX) analysis, Raman spectroscopy and electrochemical methods. The nanocomposites were immobilized by the drop-dry method, sequentially or when premixed in solution. Good electrocatalytic oxidation of l-cysteine was observed, especially by the sequentially modified electrode surface, with the CoPc on top of gCNQDs. The sensitivity was determined as 3.5 μA.mM-1 and the limit of detection (LoD) as 101.3 μM for GCE-gCNQDs, 0.65 μA.mM-1 and 0.96 μM for GCE-CoPc, 23.41 μA.mM-1 and 0.41 μM for gCNQDs-CoPc (premixed) and 100.5 μA.mM-1 and 0.02 μM for gCNQDs-CoPc (sequential). The electrode surfaces also showed high stability by continuous cyclization.
- Full Text:
- Date Issued: 2019
- Authors: Nxele, Siphesihle R , Oluwole, David O , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186746 , vital:44530 , xlink:href="https://doi.org/10.1016/j.electacta.2019.134978"
- Description: This work reports for the first time on the use of a conjugate of graphitic carbon nitride quantum dots (gCNQDs) with a push-pull asymmetrical cobalt phthalocyanine (CoPc) for electrochemical sensing. The nanocomposite is immobilized on a glassy carbon electrode (GCE) surface for the use in l-cysteine electrocatalysis. The nanocomposites were characterized using techniques such as X-ray diffractometry (XRD), Fourier transform infrared (FTIR) spectroscopy, UV-vis spectroscopy, transmission electron microscopy (TEM), energy dispersive X-ray (EDX) analysis, Raman spectroscopy and electrochemical methods. The nanocomposites were immobilized by the drop-dry method, sequentially or when premixed in solution. Good electrocatalytic oxidation of l-cysteine was observed, especially by the sequentially modified electrode surface, with the CoPc on top of gCNQDs. The sensitivity was determined as 3.5 μA.mM-1 and the limit of detection (LoD) as 101.3 μM for GCE-gCNQDs, 0.65 μA.mM-1 and 0.96 μM for GCE-CoPc, 23.41 μA.mM-1 and 0.41 μM for gCNQDs-CoPc (premixed) and 100.5 μA.mM-1 and 0.02 μM for gCNQDs-CoPc (sequential). The electrode surfaces also showed high stability by continuous cyclization.
- Full Text:
- Date Issued: 2019
Electrocatalytic Activity of Asymmetrical Cobalt Phthalocyanines in the Presence of N Doped Graphene Quantum Dots: The Push-pull Effects of Substituents
- Nkhahle, Reitumetse, Sekhosana, Kutloano E, Centane, Sixolile, Nyokong, Tebello
- Authors: Nkhahle, Reitumetse , Sekhosana, Kutloano E , Centane, Sixolile , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186904 , vital:44546 , xlink:href="https://doi.org/10.1002/elan.201800837"
- Description: A series of Co phthalocyanine (CoPc) derivatives and their respective nitrogen doped graphene quantum dot conjugates were used as catalysts towards the electrooxidation of hydrazine. Using a glassy carbon electrode as a support for the electrocatalysts, through cyclic voltammetry and chronoamperometry, the effects of combining the CoPcs with the nitrogen doped graphene quantum dots (NGQDs) were studied. The general observations made were that the NGQDs improve the catalytic activity of the CoPcs in both the p-p stacked and covalently linked conjugates by increasing the sensitivities and lowering the limits of detection with values as low as 0.43 mM being recorded.
- Full Text:
- Date Issued: 2019
- Authors: Nkhahle, Reitumetse , Sekhosana, Kutloano E , Centane, Sixolile , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186904 , vital:44546 , xlink:href="https://doi.org/10.1002/elan.201800837"
- Description: A series of Co phthalocyanine (CoPc) derivatives and their respective nitrogen doped graphene quantum dot conjugates were used as catalysts towards the electrooxidation of hydrazine. Using a glassy carbon electrode as a support for the electrocatalysts, through cyclic voltammetry and chronoamperometry, the effects of combining the CoPcs with the nitrogen doped graphene quantum dots (NGQDs) were studied. The general observations made were that the NGQDs improve the catalytic activity of the CoPcs in both the p-p stacked and covalently linked conjugates by increasing the sensitivities and lowering the limits of detection with values as low as 0.43 mM being recorded.
- Full Text:
- Date Issued: 2019
Electrocatalytic activity of ethynylbenzyl phthalocyanines when linked to quantum dots via click chemistry: Towards efficient oxygen reduction reaction and H2O2 oxidation
- Mpeta, Lekhetho S, Nyokong, Tebello
- Authors: Mpeta, Lekhetho S , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187037 , vital:44558 , xlink:href="https://doi.org/10.1016/j.jelechem.2019.03.064"
- Description: This work describes the conjugation of Co, Mn and Fe tetra ethynyl benzyl phthalocyanines to CdTe/ZnS quantum dots via click chemistry. The synthesized conjugates were then immobilised on glassy carbon electrode and their electrocatalytic activity towards hydrogen peroxide oxidation and oxygen reduction investigated. CoPc (1)-QDs showed superior electrocatalytic behaviour towards hydrogen peroxide catalysis with sensitivity of 2.8 × 105 μA/mM and limit of detection of 0.023 μM. On the other hand, FePc(3)-QDs showed the best oxygen reduction activity involving a direct 4-electron mechanism.
- Full Text:
- Date Issued: 2019
- Authors: Mpeta, Lekhetho S , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187037 , vital:44558 , xlink:href="https://doi.org/10.1016/j.jelechem.2019.03.064"
- Description: This work describes the conjugation of Co, Mn and Fe tetra ethynyl benzyl phthalocyanines to CdTe/ZnS quantum dots via click chemistry. The synthesized conjugates were then immobilised on glassy carbon electrode and their electrocatalytic activity towards hydrogen peroxide oxidation and oxygen reduction investigated. CoPc (1)-QDs showed superior electrocatalytic behaviour towards hydrogen peroxide catalysis with sensitivity of 2.8 × 105 μA/mM and limit of detection of 0.023 μM. On the other hand, FePc(3)-QDs showed the best oxygen reduction activity involving a direct 4-electron mechanism.
- Full Text:
- Date Issued: 2019
Elephant effects on treefall and logfall highlight the absence of megaherbivores in coarse woody debris conceptual frameworks
- Landman, Marietjie, Mgqatsa, Nokubonga, Cromsigt, Joris P, Kerley, Graham I H
- Authors: Landman, Marietjie , Mgqatsa, Nokubonga , Cromsigt, Joris P , Kerley, Graham I H
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/462614 , vital:76319 , xlink:href="https://doi.org/10.1016/j.foreco.2019.02.015"
- Description: Despite the importance of coarse woody debris (CWD) in woody ecosystems, conceptual frameworks of its dynamics currently exclude the role of the megaherbivores, focusing instead on the role of insects, disease, fire, wind and droughts. However, recognizing the ecological roles of the megaherbivores is one of the most urgent contemporary issues, particularly as their decline will likely have unanticipated outcomes at the ecosystem-level. Here we used sites with and without elephants in a semi-arid woodland ecosystem in South Africa to test whether elephants changed the quantitative and qualitative features of the CWD profile in relation to other wood producers. We show that elephants increased the abundance of CWD, influenced its quality by toppling mostly maturing trees, and changed the distribution of large woody items along gentle hillslopes. Surprisingly, and despite the recognized importance of both CWD and elephants for biodiversity, there is almost no published data on the role of elephants in shaping wood-living communities by changing fallen woody debris dynamics. Our study contributes towards developing a broader conceptual framework of CWD dynamics that includes the role of megaherbivores and provides a novel view of the ecological consequences of the loss of the Pleistocene megaherbivores. Our findings have important implications for CWD restoration efforts in transformed systems that previously supported megaherbivores.
- Full Text:
- Date Issued: 2019
- Authors: Landman, Marietjie , Mgqatsa, Nokubonga , Cromsigt, Joris P , Kerley, Graham I H
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/462614 , vital:76319 , xlink:href="https://doi.org/10.1016/j.foreco.2019.02.015"
- Description: Despite the importance of coarse woody debris (CWD) in woody ecosystems, conceptual frameworks of its dynamics currently exclude the role of the megaherbivores, focusing instead on the role of insects, disease, fire, wind and droughts. However, recognizing the ecological roles of the megaherbivores is one of the most urgent contemporary issues, particularly as their decline will likely have unanticipated outcomes at the ecosystem-level. Here we used sites with and without elephants in a semi-arid woodland ecosystem in South Africa to test whether elephants changed the quantitative and qualitative features of the CWD profile in relation to other wood producers. We show that elephants increased the abundance of CWD, influenced its quality by toppling mostly maturing trees, and changed the distribution of large woody items along gentle hillslopes. Surprisingly, and despite the recognized importance of both CWD and elephants for biodiversity, there is almost no published data on the role of elephants in shaping wood-living communities by changing fallen woody debris dynamics. Our study contributes towards developing a broader conceptual framework of CWD dynamics that includes the role of megaherbivores and provides a novel view of the ecological consequences of the loss of the Pleistocene megaherbivores. Our findings have important implications for CWD restoration efforts in transformed systems that previously supported megaherbivores.
- Full Text:
- Date Issued: 2019
Elucidating the Molecular Basis of the Interaction between the β2-integrin, αXβ2, and the low-affinity IgE Receptor, CD23
- Authors: Clarke, Stephen
- Date: 2019
- Subjects: CD23 antigen , Immune response Cellular immunity Molecular immunology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/37990 , vital:34277
- Description: The low affinity IgE receptor, CD23, is involved in a myriad of immune reactions. It is not only a receptor for IgE, but also functions in the regulation of IgE synthesis, isotype switching in B cells, and induction of the inflammatory response. These effector functions of CD23 arise through its interaction with another leukocyte-specific cell surface receptor – the β2 integrin subfamily. However, this interaction has not been fully described. It has been shown that CD23 is capable of interacting with the β3 and β5 integrin β-subunit of integrins via a basic RKC motif in a metal cation-independent fashion. The currently proposed mechanism for the interaction between CD23 and the integrin superfamily was applied to the β2 integrin subfamily. In this study the interaction was probed for whether or not the RKC motif governs the interaction as well. This was done by performing bioinformatics docking predictions between the CD23 and αXβ2 integrin proteins. This revealed that in the absence of cations, the RKC motif is involved in interaction with the integrin αI domain. However, since physiologically integrin activity has been shown to be regulated by metal cations, docking predictions were also performed in the presence of such cations. This showed the interaction to involve novel acidic motifs within the CD23 protein, GEF and LDL. This same pattern of interaction was seen in docking predictions between CD23 and the β2- and β3I-like domains. To further investigate, recombinant proteins of sCD23 and the αXI domain were produced using E. coli expression systems. The DNA sequence was mutated to produce mutant versions of the CD23 RKC and GEF motifs as well as a high-affinity locked αXI domain. These proteins were used in subsequent SPR spectroscopy analysis of the binding affinity between immobilised integrin and CD23 analyte. It was shown that the mutation within the RKC motif reduced the binding affinity under cation-independence, especially when the Arg172 residue was substituted. However binding was not completely lost. This result was supported by synthetic peptides containing the same RKC motif and substitutions. These showed complete loss in binding in the double RKΔAA substitution, suggesting the involvement of other residues in the RKC-dependent interaction. In contrast, under cation dependence, the RKC motif substitutions showed no effect on binding affinity, while the GEF motif substitution exhibited near complete loss in binding. This same effect on binding was validated by U937 cell-based ELISA using live cells. This showed decreased capture of differentiated U937 cells, expressing the αXβ2 integrin, by immobilised recombinant sCD23 protein. In this study it was noted that, 2 contrary to the SPR analysis, metal cations allowed for a higher titre of cells to be captured in comparison to the cation-free binding.
- Full Text:
- Date Issued: 2019
- Authors: Clarke, Stephen
- Date: 2019
- Subjects: CD23 antigen , Immune response Cellular immunity Molecular immunology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/37990 , vital:34277
- Description: The low affinity IgE receptor, CD23, is involved in a myriad of immune reactions. It is not only a receptor for IgE, but also functions in the regulation of IgE synthesis, isotype switching in B cells, and induction of the inflammatory response. These effector functions of CD23 arise through its interaction with another leukocyte-specific cell surface receptor – the β2 integrin subfamily. However, this interaction has not been fully described. It has been shown that CD23 is capable of interacting with the β3 and β5 integrin β-subunit of integrins via a basic RKC motif in a metal cation-independent fashion. The currently proposed mechanism for the interaction between CD23 and the integrin superfamily was applied to the β2 integrin subfamily. In this study the interaction was probed for whether or not the RKC motif governs the interaction as well. This was done by performing bioinformatics docking predictions between the CD23 and αXβ2 integrin proteins. This revealed that in the absence of cations, the RKC motif is involved in interaction with the integrin αI domain. However, since physiologically integrin activity has been shown to be regulated by metal cations, docking predictions were also performed in the presence of such cations. This showed the interaction to involve novel acidic motifs within the CD23 protein, GEF and LDL. This same pattern of interaction was seen in docking predictions between CD23 and the β2- and β3I-like domains. To further investigate, recombinant proteins of sCD23 and the αXI domain were produced using E. coli expression systems. The DNA sequence was mutated to produce mutant versions of the CD23 RKC and GEF motifs as well as a high-affinity locked αXI domain. These proteins were used in subsequent SPR spectroscopy analysis of the binding affinity between immobilised integrin and CD23 analyte. It was shown that the mutation within the RKC motif reduced the binding affinity under cation-independence, especially when the Arg172 residue was substituted. However binding was not completely lost. This result was supported by synthetic peptides containing the same RKC motif and substitutions. These showed complete loss in binding in the double RKΔAA substitution, suggesting the involvement of other residues in the RKC-dependent interaction. In contrast, under cation dependence, the RKC motif substitutions showed no effect on binding affinity, while the GEF motif substitution exhibited near complete loss in binding. This same effect on binding was validated by U937 cell-based ELISA using live cells. This showed decreased capture of differentiated U937 cells, expressing the αXβ2 integrin, by immobilised recombinant sCD23 protein. In this study it was noted that, 2 contrary to the SPR analysis, metal cations allowed for a higher titre of cells to be captured in comparison to the cation-free binding.
- Full Text:
- Date Issued: 2019
Empire in Lusaka: hip-hop, young men and masculinity in an African city
- Authors: Mulolani, Happy
- Date: 2019
- Subjects: Empire (Television program : 2015) -- Influence , Hip-hop -- Zambia -- Lusaka , Young men -- Zambia -- Lusaka , Young men -- Psychology -- Zambia -- Lusaka , Young men -- Social conditions -- Zambia -- Lusaka , Rap musicians -- Zambia -- Lusaka , Masculinity -- Zambia -- Lusaka
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/92650 , vital:30736
- Description: This study examines young Zambian men who are aspiring hip hop artists in Lusaka and the meanings they make of the representations of masculinity in Empire, a popular US television drama. Broadcast locally via satellite on the South African cable network, DStv, Empire narrates the story of a family of powerful men as they battle for the control of Empire, a successful hip-hop label. Of significance is how the programme’s representations of masculinity resonate with the young men’s own ideas of masculinity within a highly patriarchal and conservative urban African space. The young male hip-hop artists encounter their everyday experiences in a context of a range of socio-economic challenges within the urban space of Lusaka which presents them with very limited economic opportunities and resources. Underpinned by a constructivist approach, this reception study explores how these young male artists encounter their everyday experiences in the city and how its structural constraints are navigated through hip-hop, a highly popular local cultural form. The male artists’ reactions to the programme are dependent on their socio-economic location and the types of skills and resources they draw on in order to traverse their everyday experience of city life which concurrently is perceived as exclusionary and as impacting on their livelihoods and aspirations.
- Full Text:
- Date Issued: 2019
- Authors: Mulolani, Happy
- Date: 2019
- Subjects: Empire (Television program : 2015) -- Influence , Hip-hop -- Zambia -- Lusaka , Young men -- Zambia -- Lusaka , Young men -- Psychology -- Zambia -- Lusaka , Young men -- Social conditions -- Zambia -- Lusaka , Rap musicians -- Zambia -- Lusaka , Masculinity -- Zambia -- Lusaka
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/92650 , vital:30736
- Description: This study examines young Zambian men who are aspiring hip hop artists in Lusaka and the meanings they make of the representations of masculinity in Empire, a popular US television drama. Broadcast locally via satellite on the South African cable network, DStv, Empire narrates the story of a family of powerful men as they battle for the control of Empire, a successful hip-hop label. Of significance is how the programme’s representations of masculinity resonate with the young men’s own ideas of masculinity within a highly patriarchal and conservative urban African space. The young male hip-hop artists encounter their everyday experiences in a context of a range of socio-economic challenges within the urban space of Lusaka which presents them with very limited economic opportunities and resources. Underpinned by a constructivist approach, this reception study explores how these young male artists encounter their everyday experiences in the city and how its structural constraints are navigated through hip-hop, a highly popular local cultural form. The male artists’ reactions to the programme are dependent on their socio-economic location and the types of skills and resources they draw on in order to traverse their everyday experience of city life which concurrently is perceived as exclusionary and as impacting on their livelihoods and aspirations.
- Full Text:
- Date Issued: 2019
Employee happiness at ARMSCOR
- Authors: Rakgabyane, Michael Tsie
- Date: 2019
- Subjects: Employee morale
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/43018 , vital:36732
- Description: The subject of happiness has captured many across the world. There is an increasing debate on whether there is a link between improving the national happiness levels and country’s Gross Domestic Product (GDP). Happiness has become an area of interest for both organisations and individuals because of the consequential benefits. Research affirmed the importance of happiness in improving the function of both society and organisations. The benefit thereof includes but is not limited to increased productivity and longevity. Having unhappy employees could have dire effects on the organisations due to the direct impact on the organisation’s financial and social conditions. The arms industry is generally seen as a highly secretive industry due to the strategic position and importance that it occupies in various countries. Happiness in the arms industry has never been explored. This makes this study new in this particular industry. The arms industry as a whole can also benefit by focusing on improving employees’ happiness levels. This makes the study in Armscor important as it would help to provide some insight on the happiness levels in this industry. The focus of this study is to establish happiness levels of Armscor employees. For the purpose of this study, the primary data for the study were collected from a representative sample of 170 Armscor employees which included 161 permanent and 9 non-permanent employees. The questionnaire designed from the literature was used to collect the data. The in-depth literature review that was conducted in carrying out this study included exploring the different perspectives from which happiness is defined. This included three seemingly dominant perspectives: philosophic, economic and psychological perspectives. Furthermore, the review of literature included examining happiness theories and explored three main theories: Comparison, Folklore and Livability. The literature review provided a basis for a proposed conceptual model, which suggested the following factors as influencing happiness in the workplace: workplace influence, workplace relationships, work-life balance, purpose, optimism, work satisfaction, leisure, SA pride and trust. Exploratory factor analysis was used to test the proposed conceptual model and the results indicate that workplace influence, workplace vi relationships and work satisfaction load onto the factor work; while trust and SA pride load onto the factor trust pride; and purpose, work-life balance and optimism load onto the factor purpose work-life optimism. The treatise concludes with recommendations that management can consider implementing to improve the happiness levels of employees at Armscor. This study contributes to understanding the happiness levels of employees in the arms industry.
- Full Text:
- Date Issued: 2019
- Authors: Rakgabyane, Michael Tsie
- Date: 2019
- Subjects: Employee morale
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/43018 , vital:36732
- Description: The subject of happiness has captured many across the world. There is an increasing debate on whether there is a link between improving the national happiness levels and country’s Gross Domestic Product (GDP). Happiness has become an area of interest for both organisations and individuals because of the consequential benefits. Research affirmed the importance of happiness in improving the function of both society and organisations. The benefit thereof includes but is not limited to increased productivity and longevity. Having unhappy employees could have dire effects on the organisations due to the direct impact on the organisation’s financial and social conditions. The arms industry is generally seen as a highly secretive industry due to the strategic position and importance that it occupies in various countries. Happiness in the arms industry has never been explored. This makes this study new in this particular industry. The arms industry as a whole can also benefit by focusing on improving employees’ happiness levels. This makes the study in Armscor important as it would help to provide some insight on the happiness levels in this industry. The focus of this study is to establish happiness levels of Armscor employees. For the purpose of this study, the primary data for the study were collected from a representative sample of 170 Armscor employees which included 161 permanent and 9 non-permanent employees. The questionnaire designed from the literature was used to collect the data. The in-depth literature review that was conducted in carrying out this study included exploring the different perspectives from which happiness is defined. This included three seemingly dominant perspectives: philosophic, economic and psychological perspectives. Furthermore, the review of literature included examining happiness theories and explored three main theories: Comparison, Folklore and Livability. The literature review provided a basis for a proposed conceptual model, which suggested the following factors as influencing happiness in the workplace: workplace influence, workplace relationships, work-life balance, purpose, optimism, work satisfaction, leisure, SA pride and trust. Exploratory factor analysis was used to test the proposed conceptual model and the results indicate that workplace influence, workplace vi relationships and work satisfaction load onto the factor work; while trust and SA pride load onto the factor trust pride; and purpose, work-life balance and optimism load onto the factor purpose work-life optimism. The treatise concludes with recommendations that management can consider implementing to improve the happiness levels of employees at Armscor. This study contributes to understanding the happiness levels of employees in the arms industry.
- Full Text:
- Date Issued: 2019
Employee talent management in the Uganda health sector: a public institutions perspective
- Authors: Nakato, Jamidah
- Date: 2019
- Subjects: Employee retention -- Uganda , Leadership -- Uganda Executives -- Training of Executive ability
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/41751 , vital:36578
- Description: Globally, talent management has been acknowledged as a prime source of employee attraction and retention as well as organisational performance and commitment. Although the health sector plays an important role in the economic development of any country, in Uganda, the management of talented employees still remains a challenge. In this country, many institutions have not incorporated and adopted suitable talent management strategies, thus compromising access to and quality of care. A hypothetical model and measuring instruments were developed to investigate the factors contributing to and the benefits of effective employee talent management in the Ugandan health sector. The following ten independent variables that have the prospect of influencing effective talent management (intervening variable) were identified on the basis of organisational, management and personal factors: talent pool, organisational support, work conditions, social and work environment, reward system, leadership styles, career development, supervisor support, employee engagement and employee personality. In this study, it was also postulated that talent management has potential to effect the dependent variables, namely, talent attraction, employee retention, organisational performance and organisational commitment. In total, fourteen hypotheses were formulated to test relationships between independent, intervening and dependent variables. The study utilised the quantitative research paradigm in order to seek employee perceptions regarding public institutions within the health sector, in Uganda’s Central region. Using stratified random sampling, a sample of 910 participants was drawn from the identified population. A survey was conducted with the aid of a structured, selfadministered questionnaire that was distributed to the seven categories of hospitals and health centres in Central Uganda; 910 questionnaires were distributed to doctors, consultants, dentists, dispensers, nurses, pharmacists, clinical officers, laboratory staff, occupational therapists, allied health staff, environmental health officers, general administrative cadres, cold chain technicians and support staff. Of these, 655 were useable, which indicates a 71% response rate. The data collected was captured and analysed using various statistical analysis techniques. The study findings reveal that organisational support, employee satisfaction, an enabling work environment, a stable working environment and career development effectively influence talent management. However, management in health sector institutions need to realise the importance of facilitating and monitoring job autonomy and personal values in order to effectively enhance talent management. The study results further reveal that talent management has a positive influence on employee retention and holistic development for organisational performance. For optimal talent management, the study recommends that organisations pay attention to cultivating an enabling and stable work environment that is suitable for motivating employees towards improved performance and work commitment. Therefore, health sector management should focus on potential, and not only on performance, by matching individuals with the right positions that can expose their capabilities and potential. It was further recommended that organisations need to accept and show confidence in their employees by allowing them freedom in carrying out their tasks. In addition, it was highlighted that ascertaining and utilising information about the values and principles that employees hold can help explain their behaviours and attitudes at work. This would increase the chances of talented employees realising their full potential and competencies in their jobs. Therefore, this study found that there is a need for public institutions within the health sector to focus on supporting employees by offering a well-defined career development programme, which caters for the needs of individuals and which acts as an incentive for the recruitment of qualified employees. Thus, management will succeed in retaining, attracting and maintaining talented individuals who can perform well. In order to uphold the expected ethical behaviour of conducting research, the researcher obtained approval and ethics clearance from Nelson Mandela University, permission to conduct the study from the Ugandan Ministry of Health, and communicated all the information relevant to the study to the participants.
- Full Text:
- Date Issued: 2019
- Authors: Nakato, Jamidah
- Date: 2019
- Subjects: Employee retention -- Uganda , Leadership -- Uganda Executives -- Training of Executive ability
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/41751 , vital:36578
- Description: Globally, talent management has been acknowledged as a prime source of employee attraction and retention as well as organisational performance and commitment. Although the health sector plays an important role in the economic development of any country, in Uganda, the management of talented employees still remains a challenge. In this country, many institutions have not incorporated and adopted suitable talent management strategies, thus compromising access to and quality of care. A hypothetical model and measuring instruments were developed to investigate the factors contributing to and the benefits of effective employee talent management in the Ugandan health sector. The following ten independent variables that have the prospect of influencing effective talent management (intervening variable) were identified on the basis of organisational, management and personal factors: talent pool, organisational support, work conditions, social and work environment, reward system, leadership styles, career development, supervisor support, employee engagement and employee personality. In this study, it was also postulated that talent management has potential to effect the dependent variables, namely, talent attraction, employee retention, organisational performance and organisational commitment. In total, fourteen hypotheses were formulated to test relationships between independent, intervening and dependent variables. The study utilised the quantitative research paradigm in order to seek employee perceptions regarding public institutions within the health sector, in Uganda’s Central region. Using stratified random sampling, a sample of 910 participants was drawn from the identified population. A survey was conducted with the aid of a structured, selfadministered questionnaire that was distributed to the seven categories of hospitals and health centres in Central Uganda; 910 questionnaires were distributed to doctors, consultants, dentists, dispensers, nurses, pharmacists, clinical officers, laboratory staff, occupational therapists, allied health staff, environmental health officers, general administrative cadres, cold chain technicians and support staff. Of these, 655 were useable, which indicates a 71% response rate. The data collected was captured and analysed using various statistical analysis techniques. The study findings reveal that organisational support, employee satisfaction, an enabling work environment, a stable working environment and career development effectively influence talent management. However, management in health sector institutions need to realise the importance of facilitating and monitoring job autonomy and personal values in order to effectively enhance talent management. The study results further reveal that talent management has a positive influence on employee retention and holistic development for organisational performance. For optimal talent management, the study recommends that organisations pay attention to cultivating an enabling and stable work environment that is suitable for motivating employees towards improved performance and work commitment. Therefore, health sector management should focus on potential, and not only on performance, by matching individuals with the right positions that can expose their capabilities and potential. It was further recommended that organisations need to accept and show confidence in their employees by allowing them freedom in carrying out their tasks. In addition, it was highlighted that ascertaining and utilising information about the values and principles that employees hold can help explain their behaviours and attitudes at work. This would increase the chances of talented employees realising their full potential and competencies in their jobs. Therefore, this study found that there is a need for public institutions within the health sector to focus on supporting employees by offering a well-defined career development programme, which caters for the needs of individuals and which acts as an incentive for the recruitment of qualified employees. Thus, management will succeed in retaining, attracting and maintaining talented individuals who can perform well. In order to uphold the expected ethical behaviour of conducting research, the researcher obtained approval and ethics clearance from Nelson Mandela University, permission to conduct the study from the Ugandan Ministry of Health, and communicated all the information relevant to the study to the participants.
- Full Text:
- Date Issued: 2019
Employing the Processing Capability of Mixing Consoles and Audio Interfaces to Spatialize Sound:
- Authors: Foss, Richard
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426758 , vital:72389 , https://www.aes.org/e-lib/browse.cfm?elib=22211
- Description: Many audio interfaces and all mixing consoles have signal mixing capabilities. This paper describes an immersive sound system that employs these capabilities in order to spatialise sound sources, where these sources could be any of the inputs to these mix-capable devices. Graphic spatialisation control is provided on client devices, and 3D coordinates are sent to a server. The server uses these coordinates and speaker positions to render mix level and reverb parameter values. These values are sent to the mixer device using a control protocol. Advantages of this approach are that all inputs can be spatialised, and low-level processing is offloaded from the computer.
- Full Text:
- Date Issued: 2019
- Authors: Foss, Richard
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426758 , vital:72389 , https://www.aes.org/e-lib/browse.cfm?elib=22211
- Description: Many audio interfaces and all mixing consoles have signal mixing capabilities. This paper describes an immersive sound system that employs these capabilities in order to spatialise sound sources, where these sources could be any of the inputs to these mix-capable devices. Graphic spatialisation control is provided on client devices, and 3D coordinates are sent to a server. The server uses these coordinates and speaker positions to render mix level and reverb parameter values. These values are sent to the mixer device using a control protocol. Advantages of this approach are that all inputs can be spatialised, and low-level processing is offloaded from the computer.
- Full Text:
- Date Issued: 2019