Development of an Extensible Framework for Easy Implementation of Image Processing Applications on Android Operating System
- Authors: Gunu, Bulelani
- Date: 2019
- Subjects: Operating systems (Computers)
- Language: English
- Type: Thesis , Masters , MSc (Computer Science )
- Identifier: http://hdl.handle.net/10353/17201 , vital:40865
- Description: Image processing is a field that has been in existence for many years and it continues to grow with many other research areas adopting its use. One such research area is the area of mobile devices. Mobile devices have been equipped with image processing software and hardware so as to apply image processing features. While there are many applications of image processing and new applications have been developed, there are still many functionalities that these image processing software perform the same. The development of these software from scratch requires a lot of effort and can be time consuming. This becomes even worse for mobile device application developers, specifically Android developers, who have no knowledge of implementing image processing functionalities. This project offers a software framework which allows Android application developers to focus on their unique requirements while incorporating image processing features into their applications. The framework provides the common image processing functionalities and Android developers do not need to know the internal working of the framework in order to use it. This helps reduce application development time and effort. The framework also offers an extensibility feature which takes into consideration the future growth. This means that third party developers can keep the framework up to date with the technological advancements. The presented framework is shown to be requiring less technical expertise. Also, the way in which the system is design makes it easy to understand. This design can be adopted for other related projects that require extensible frameworks for the Android operating system.
- Full Text:
- Date Issued: 2019
- Authors: Gunu, Bulelani
- Date: 2019
- Subjects: Operating systems (Computers)
- Language: English
- Type: Thesis , Masters , MSc (Computer Science )
- Identifier: http://hdl.handle.net/10353/17201 , vital:40865
- Description: Image processing is a field that has been in existence for many years and it continues to grow with many other research areas adopting its use. One such research area is the area of mobile devices. Mobile devices have been equipped with image processing software and hardware so as to apply image processing features. While there are many applications of image processing and new applications have been developed, there are still many functionalities that these image processing software perform the same. The development of these software from scratch requires a lot of effort and can be time consuming. This becomes even worse for mobile device application developers, specifically Android developers, who have no knowledge of implementing image processing functionalities. This project offers a software framework which allows Android application developers to focus on their unique requirements while incorporating image processing features into their applications. The framework provides the common image processing functionalities and Android developers do not need to know the internal working of the framework in order to use it. This helps reduce application development time and effort. The framework also offers an extensibility feature which takes into consideration the future growth. This means that third party developers can keep the framework up to date with the technological advancements. The presented framework is shown to be requiring less technical expertise. Also, the way in which the system is design makes it easy to understand. This design can be adopted for other related projects that require extensible frameworks for the Android operating system.
- Full Text:
- Date Issued: 2019
Distribution of virulence determinants in some members of the ESKAPE pathogens isolated from selected hospital wastewater effluents in the Eastern Cape, South Africa
- Authors: Mapipa, Qaqamba
- Date: 2019
- Subjects: Effluent quality Water -- Purification
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: http://hdl.handle.net/10353/14704 , vital:40061
- Description: Members of ESKAPE pathogens are grouped under the acronymn made up of Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species. ESKAPE pathogens, isolated from hospitals and communities, have just been characterized for new pathogenesis and transmission patterns and overcoming the usefulness of available drugs, this leads to infections that tend to increase the rate of disease in a population and death rate and cost our society massively. The distribution of virulence determinants and the antibiotic susceptibility patterns in some members of the ESKAPE pathogens isolated from hospital wastewater facilities that were selected within the Eastern Cape Province, South Africa was evaluated. Water samples from the hospital wastewater facilities were collected fortnightly over a period of three (3) months (February to April). Spread plate technique was employed for the enumeration and isolation of the members of ESKAPE pathogens. A total of 725 presumptive ESKAPE isolates were collected, screened and Polymerase Chain Reaction (PCR) amplification of target determinants was performed. Results showed that Klebsiella pneumoniae tested positive for ninety two (92=35.9%) samples, Enterobacter cloacae fifty seven (57=22.2%) samples tested positive, Pseudomonas aeruginosa fifty four (54=21.09%) isolates tested positive and fifty three (53=20.7%) isolates tested positive for Acinetobacter baumannii making a total of 256 isolates which tested positive for some members of ESKAPE pathogens. The detection of some members of the ESKAPE pathogens in these Hospitals is a cause of concern to public health. A total of 256 ESKAPE isolates that were obtained from the hospital wastewater facilities; were subjected to antibiotic susceptibility test in order to determine their antibiotic-resistant profiles. ESKAPE isolates recovered from the three hospital effluents showing resistance to antimicrobial agents in this study were further evaluated for resistance determinants namely, sulfonamides resistance determinants (sulI and sulII), β-lactams (ampC, blaTEM and blaZ), tetracyclines (tetA, tetB, tetC and tetM), 10 chloramphenicol’s (catI and catII) and aminoglycoside resistance determinants (aacC2, apHAI and apHAII). The resistant determinants targeted have been evaluated through their prevalence and the following distributions were obtained: [β-Lactams; ampC (80%), blaTEM (77%)]; [Tetracyclines; tetA (87%)]; [Sulfonamides; sulI (79%)]; [Aminoglycosides; aacC2 (12%), aphA2 (52%) and aadA (18%)]. With the worldwide increase in these resistant occurrences, the execution of strict infection control policies and treatment with different antimicrobials needs hasty detection. Comprehensive data are therefore needed so that the history of infection, identification of genes present in organisms and monitoring of changes in infection patterns can be traced correctly.
- Full Text:
- Date Issued: 2019
- Authors: Mapipa, Qaqamba
- Date: 2019
- Subjects: Effluent quality Water -- Purification
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: http://hdl.handle.net/10353/14704 , vital:40061
- Description: Members of ESKAPE pathogens are grouped under the acronymn made up of Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species. ESKAPE pathogens, isolated from hospitals and communities, have just been characterized for new pathogenesis and transmission patterns and overcoming the usefulness of available drugs, this leads to infections that tend to increase the rate of disease in a population and death rate and cost our society massively. The distribution of virulence determinants and the antibiotic susceptibility patterns in some members of the ESKAPE pathogens isolated from hospital wastewater facilities that were selected within the Eastern Cape Province, South Africa was evaluated. Water samples from the hospital wastewater facilities were collected fortnightly over a period of three (3) months (February to April). Spread plate technique was employed for the enumeration and isolation of the members of ESKAPE pathogens. A total of 725 presumptive ESKAPE isolates were collected, screened and Polymerase Chain Reaction (PCR) amplification of target determinants was performed. Results showed that Klebsiella pneumoniae tested positive for ninety two (92=35.9%) samples, Enterobacter cloacae fifty seven (57=22.2%) samples tested positive, Pseudomonas aeruginosa fifty four (54=21.09%) isolates tested positive and fifty three (53=20.7%) isolates tested positive for Acinetobacter baumannii making a total of 256 isolates which tested positive for some members of ESKAPE pathogens. The detection of some members of the ESKAPE pathogens in these Hospitals is a cause of concern to public health. A total of 256 ESKAPE isolates that were obtained from the hospital wastewater facilities; were subjected to antibiotic susceptibility test in order to determine their antibiotic-resistant profiles. ESKAPE isolates recovered from the three hospital effluents showing resistance to antimicrobial agents in this study were further evaluated for resistance determinants namely, sulfonamides resistance determinants (sulI and sulII), β-lactams (ampC, blaTEM and blaZ), tetracyclines (tetA, tetB, tetC and tetM), 10 chloramphenicol’s (catI and catII) and aminoglycoside resistance determinants (aacC2, apHAI and apHAII). The resistant determinants targeted have been evaluated through their prevalence and the following distributions were obtained: [β-Lactams; ampC (80%), blaTEM (77%)]; [Tetracyclines; tetA (87%)]; [Sulfonamides; sulI (79%)]; [Aminoglycosides; aacC2 (12%), aphA2 (52%) and aadA (18%)]. With the worldwide increase in these resistant occurrences, the execution of strict infection control policies and treatment with different antimicrobials needs hasty detection. Comprehensive data are therefore needed so that the history of infection, identification of genes present in organisms and monitoring of changes in infection patterns can be traced correctly.
- Full Text:
- Date Issued: 2019
Effect of dietary Mucuna pruriens seed meal on the serum lipid profile and bone quality traits of broiler chickens
- Authors: Hempe, Chumani
- Date: 2019
- Subjects: Legumes Lipoproteins
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17213 , vital:40866
- Description: This study aimed at evaluating the effects of heated Mucuna pruriens seed meal on the blood serum lipid profile and bone quality parameters of broiler chickens. A total of 120 day-old unsexed Cobb 500 broiler chicks were randomly allocated for the 4 treatment diets (T1, T2, T3 and T4) containing 0, 10, 15, and 20% heated Mucuna pruriens seed meal. The birds were reared on wood shaving floor pens for 35 days. Birds were humanely slaughtered by severing the jugular vein using a sharp knife. Blood was collected into a tube, centrifuge and analyzed for a lipid profile analysis (total cholesterol (TC), high density lipoproteins (HDL), low density lipoproteins (LDL), triglycerides (TCD) as well as aspartate transaminase (AST) and alanine transaminase (ALT)) by enzymatic diagnostic kits (Diasys diagnostic kits). Both drumsticks severed using a sharp knife. After boiling in the water at 100°C for 10 mins the tibia bones were taken, air-dried for 96 hrs at room temperature and measured for weights. Bone length, strength, moisture and ash content as well as morphology were measured. The blood lipid profile of birds fed T1 was high (P < 0.05) for all the parameters measured, while T3 had the lowest (P < 0.05) profile. T2 and T4 had the same profile. ALT was found to be highest (P < 0.05) for T4 (5.27 ± 0.207/L) and lowest (P < 0.05) for T2 (4.67 ± 0.333/L) while AST was highest (P < 0.05) for T2 (320.13 ± 28.851/L) and lowest (P < 0.05) for T3 (208.47 ± 10.059/L). Treatment diet 3 (T3) was observed decreased bone quality among all diets; with the lowest (P < 0.05) bone strength (188.55 ± 12.039N), bone length (8.59 ± 0.131cm) and morphology (1.69 ± 0.058). Mucuna pruriens seed meal inclusion in broiler diets reduces blood serum lipids and 20% inclusion levels have no adverse effects on the bone quality attributes
- Full Text:
- Date Issued: 2019
- Authors: Hempe, Chumani
- Date: 2019
- Subjects: Legumes Lipoproteins
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17213 , vital:40866
- Description: This study aimed at evaluating the effects of heated Mucuna pruriens seed meal on the blood serum lipid profile and bone quality parameters of broiler chickens. A total of 120 day-old unsexed Cobb 500 broiler chicks were randomly allocated for the 4 treatment diets (T1, T2, T3 and T4) containing 0, 10, 15, and 20% heated Mucuna pruriens seed meal. The birds were reared on wood shaving floor pens for 35 days. Birds were humanely slaughtered by severing the jugular vein using a sharp knife. Blood was collected into a tube, centrifuge and analyzed for a lipid profile analysis (total cholesterol (TC), high density lipoproteins (HDL), low density lipoproteins (LDL), triglycerides (TCD) as well as aspartate transaminase (AST) and alanine transaminase (ALT)) by enzymatic diagnostic kits (Diasys diagnostic kits). Both drumsticks severed using a sharp knife. After boiling in the water at 100°C for 10 mins the tibia bones were taken, air-dried for 96 hrs at room temperature and measured for weights. Bone length, strength, moisture and ash content as well as morphology were measured. The blood lipid profile of birds fed T1 was high (P < 0.05) for all the parameters measured, while T3 had the lowest (P < 0.05) profile. T2 and T4 had the same profile. ALT was found to be highest (P < 0.05) for T4 (5.27 ± 0.207/L) and lowest (P < 0.05) for T2 (4.67 ± 0.333/L) while AST was highest (P < 0.05) for T2 (320.13 ± 28.851/L) and lowest (P < 0.05) for T3 (208.47 ± 10.059/L). Treatment diet 3 (T3) was observed decreased bone quality among all diets; with the lowest (P < 0.05) bone strength (188.55 ± 12.039N), bone length (8.59 ± 0.131cm) and morphology (1.69 ± 0.058). Mucuna pruriens seed meal inclusion in broiler diets reduces blood serum lipids and 20% inclusion levels have no adverse effects on the bone quality attributes
- Full Text:
- Date Issued: 2019
Effect of grazing systems on growth performance, carcass characteristic, meat quality of beef cattle and economic performance of the enterprise
- Authors: Dayimani, Siyavuya
- Date: 2019
- Subjects: Grazing -- Environmental aspects Meat -- Quality
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17294 , vital:40873
- Description: Under conditions of adaptive Holistic Management™, we tested whether rotational grazing approaches such as holistic planned grazing (HPG) and four-camp grazing (FCG) influence growth, carcass and meat quality attributes of beef steers compared to continuous, seasonlong (SLG) grazing. Thirty steers (250 ±19.56 kg, 16-17-month-old) were randomly assigned to SLG, HPG and FCG systems (10 steers/ treatment) at a private farm in Cedarville, Eastern Cape Province, South Africa where grazing was managed using an adaptive approach involving inter alia planned grazing charts, seasonal movement of cattle, and supplemental feeding. The steers were slaughtered at 40-41 months for carcass measurements and longissimus et lumborum was sampled for meat quality analyses. All the grazing systems had comparable live weights and average daily gain. All the investigated carcass attributes were also similar across grazing treatments (P > 0.05). Meat from steers on the SLG system had higher (P<0.05) drip loss, protein and fat contents and lower (P <0.05) shear force, moisture and ash contents than the two rotational grazing approaches (HPG and FCG). The HPG had higher (P < 0.05) total running and capital costs compared to SLG and FCG grazing systems. The SLG system had greater (P ≤ 0.05) gross and net income compared to FCG and HPG systems, respectively. Overall, all the grazing systems had comparable growth performance, carcass characteristics and meat quality but rotational grazing systems had lower gross income relative to the SLG grazing system.
- Full Text:
- Date Issued: 2019
- Authors: Dayimani, Siyavuya
- Date: 2019
- Subjects: Grazing -- Environmental aspects Meat -- Quality
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17294 , vital:40873
- Description: Under conditions of adaptive Holistic Management™, we tested whether rotational grazing approaches such as holistic planned grazing (HPG) and four-camp grazing (FCG) influence growth, carcass and meat quality attributes of beef steers compared to continuous, seasonlong (SLG) grazing. Thirty steers (250 ±19.56 kg, 16-17-month-old) were randomly assigned to SLG, HPG and FCG systems (10 steers/ treatment) at a private farm in Cedarville, Eastern Cape Province, South Africa where grazing was managed using an adaptive approach involving inter alia planned grazing charts, seasonal movement of cattle, and supplemental feeding. The steers were slaughtered at 40-41 months for carcass measurements and longissimus et lumborum was sampled for meat quality analyses. All the grazing systems had comparable live weights and average daily gain. All the investigated carcass attributes were also similar across grazing treatments (P > 0.05). Meat from steers on the SLG system had higher (P<0.05) drip loss, protein and fat contents and lower (P <0.05) shear force, moisture and ash contents than the two rotational grazing approaches (HPG and FCG). The HPG had higher (P < 0.05) total running and capital costs compared to SLG and FCG grazing systems. The SLG system had greater (P ≤ 0.05) gross and net income compared to FCG and HPG systems, respectively. Overall, all the grazing systems had comparable growth performance, carcass characteristics and meat quality but rotational grazing systems had lower gross income relative to the SLG grazing system.
- Full Text:
- Date Issued: 2019
Effects of herbicide application and phosphorous fertilization on forage production and plant density of abandoned lands planted with pasture legumes
- Authors: Mashece , Wandile
- Date: 2019
- Subjects: Forage plants Grazing
- Language: English
- Type: Thesis , Masters , MSc (Pasture Science)
- Identifier: http://hdl.handle.net/10353/11950 , vital:39121
- Description: The study was conducted in two communal abandoned grazing lands, namely; Sinqumeni and Kubedlana (referred hereafter as sites) located in the Eastern Cape Province (ECP) where legume pastures have been successfully established for the last ten years. The objectives of the study were to investigate the effects of five different herbicide treatments and four different phosphorus fertilizer application rates on forage production and plant density of abandoned lands. At each site, an area previously planted with legume species and well established with an even stand of legumes were selected. For both experimental sites, experimental design consisted of plot size of 50 m × 50 m for herbicide plot and 25 m ×25 m for phosphorus plot with 5 m×10 m of sub-plot planted with an even stand of pasture legumes arranged in a randomised complete block design (RCBD) in two blocks. The legumes that were planted in these sites were: Lotus corniculatus, White clover, Arrow leaf clover, Yellow serradella, Pitman serradella, Biserrula and Lespedeza cuneata. Prior to planting, the legume seeds were mixed with the appropriate inoculant by hand. Planting was done by over sowing legumes into the natural pastures (grasses) using an Aitchison Mini seeder. In each small plot, data was collected on forage biomass and plant density (species count). Data was analysed using the SAS programme and the significance of differences between means were tested with Fisher’s test for the LSD. On herbicide study, results showed that there were no significant (p > 0.05) difference in forage dry matter (DM) among the herbicide treatments in both years at Kubedlana. Results further showed that all five herbicides did not significantly (p > 0.05) increase the DM yield over control treatment. At Sinqumeni, results displayed no significant (p > 0.05) difference in forage DM among treatments during year 1, whereas in year 2, but all herbicide treatments except Haloxyfop-R methyl & Bendioxide (HBE) yielded greater (p < 0.05) DM yield than the control treatment. Comparing years, forage DM yield only under Bendioxide (BEN) and Paraquat (PAR) treatments had greater DM yield in year 2 than years 1. In Kubedlana, Bendioxide (BEN) and Haloxyfop-R methyl (HAL) treatments showed an IV increase in total density (TD), whereas Glyphosate (GLY) produced the lowest total density (TD) and Paraquat (PAR) and Haloxyfop-R methyl (HAL) resulted in an increased in density of total legumes (TL) relative to control treatment. There was a decline (p < 0.05) in the densities of total plants and forbs from year 1 to year 2. In Sinqumeni, herbicide applications resulted in higher density of total legumes than the control treatment, but results varied among herbicide treatments, greatest density being obtained at Haloxyfop-R methyl & Bendioxide (HBE) and Haloxyfop-R methyl (HAL) treatments. On phosphorus study, result showed a significant (p < 0.05) differences in dry matter (DM) yield among Phosphorus (P) treatments during year 2 of the study at Kubedlana site. All P treatments showed significantly greater dry matter (DM) yield in forage harvested in year 2 compared to year 1. At Sinqumeni, results showed Phosphorus (P) application did not have significance (p > 0.05) effect on forage dry matter (DM) yield on both years. In Kubedlana, there were indications of increased densities of total grasses, legumes and total plants in response to some levels of phosphorus (P) treatments. Treatment Phosphorus at 20 kg ha-1 (P20) yielded the highest total density (TD) and total legumes (TL) numbers and P10 had the lowest total density (TD). Both treatment and year interacted significantly (p < 0.05) to influence the mean density of some plant variables. At Sinqumeni, there were no significant differences due to phosphorus (P) treatments in the densities of total plants, grasses and forbs. Both years interacted significantly (p < 0.05) with treatments to influence the plant density mean, with Lespedeza cuneate (LESP) producing the highest plant density during year 1 and year 2, whereas BSERRL produced the lowest plant density during year 1 and year 2 periods. Therefore, findings of this study suggest that application of both Bendioxide (BEN) & Haloxyfop-R methyl & Bendioxide (HBE) treatments result in a decrease in dry matter (DM) yield, whereas Glyphosate (GLY) herbicide resulted in a decrease in both total density (TD) and total legumes (TL) and Haloxyfop-R methyl (HAL) herbicide application resulted in an increase of total density (TD) and total legumes (TL) V relative to control plot. On phosphorus study, results suggest that at Phosphorus at 40 kg ha-1 (P40) fertilization dry matter (DM) yield will be increased and at both Phosphorus at 20 kg ha1 (P20) and Phosphorus at 40 kg ha-1 (P40) high total density (TD) will be recorded where’s Phosphorus at 20 kg ha-1 (P20) fertilization result in high total legumes (TL).
- Full Text:
- Date Issued: 2019
- Authors: Mashece , Wandile
- Date: 2019
- Subjects: Forage plants Grazing
- Language: English
- Type: Thesis , Masters , MSc (Pasture Science)
- Identifier: http://hdl.handle.net/10353/11950 , vital:39121
- Description: The study was conducted in two communal abandoned grazing lands, namely; Sinqumeni and Kubedlana (referred hereafter as sites) located in the Eastern Cape Province (ECP) where legume pastures have been successfully established for the last ten years. The objectives of the study were to investigate the effects of five different herbicide treatments and four different phosphorus fertilizer application rates on forage production and plant density of abandoned lands. At each site, an area previously planted with legume species and well established with an even stand of legumes were selected. For both experimental sites, experimental design consisted of plot size of 50 m × 50 m for herbicide plot and 25 m ×25 m for phosphorus plot with 5 m×10 m of sub-plot planted with an even stand of pasture legumes arranged in a randomised complete block design (RCBD) in two blocks. The legumes that were planted in these sites were: Lotus corniculatus, White clover, Arrow leaf clover, Yellow serradella, Pitman serradella, Biserrula and Lespedeza cuneata. Prior to planting, the legume seeds were mixed with the appropriate inoculant by hand. Planting was done by over sowing legumes into the natural pastures (grasses) using an Aitchison Mini seeder. In each small plot, data was collected on forage biomass and plant density (species count). Data was analysed using the SAS programme and the significance of differences between means were tested with Fisher’s test for the LSD. On herbicide study, results showed that there were no significant (p > 0.05) difference in forage dry matter (DM) among the herbicide treatments in both years at Kubedlana. Results further showed that all five herbicides did not significantly (p > 0.05) increase the DM yield over control treatment. At Sinqumeni, results displayed no significant (p > 0.05) difference in forage DM among treatments during year 1, whereas in year 2, but all herbicide treatments except Haloxyfop-R methyl & Bendioxide (HBE) yielded greater (p < 0.05) DM yield than the control treatment. Comparing years, forage DM yield only under Bendioxide (BEN) and Paraquat (PAR) treatments had greater DM yield in year 2 than years 1. In Kubedlana, Bendioxide (BEN) and Haloxyfop-R methyl (HAL) treatments showed an IV increase in total density (TD), whereas Glyphosate (GLY) produced the lowest total density (TD) and Paraquat (PAR) and Haloxyfop-R methyl (HAL) resulted in an increased in density of total legumes (TL) relative to control treatment. There was a decline (p < 0.05) in the densities of total plants and forbs from year 1 to year 2. In Sinqumeni, herbicide applications resulted in higher density of total legumes than the control treatment, but results varied among herbicide treatments, greatest density being obtained at Haloxyfop-R methyl & Bendioxide (HBE) and Haloxyfop-R methyl (HAL) treatments. On phosphorus study, result showed a significant (p < 0.05) differences in dry matter (DM) yield among Phosphorus (P) treatments during year 2 of the study at Kubedlana site. All P treatments showed significantly greater dry matter (DM) yield in forage harvested in year 2 compared to year 1. At Sinqumeni, results showed Phosphorus (P) application did not have significance (p > 0.05) effect on forage dry matter (DM) yield on both years. In Kubedlana, there were indications of increased densities of total grasses, legumes and total plants in response to some levels of phosphorus (P) treatments. Treatment Phosphorus at 20 kg ha-1 (P20) yielded the highest total density (TD) and total legumes (TL) numbers and P10 had the lowest total density (TD). Both treatment and year interacted significantly (p < 0.05) to influence the mean density of some plant variables. At Sinqumeni, there were no significant differences due to phosphorus (P) treatments in the densities of total plants, grasses and forbs. Both years interacted significantly (p < 0.05) with treatments to influence the plant density mean, with Lespedeza cuneate (LESP) producing the highest plant density during year 1 and year 2, whereas BSERRL produced the lowest plant density during year 1 and year 2 periods. Therefore, findings of this study suggest that application of both Bendioxide (BEN) & Haloxyfop-R methyl & Bendioxide (HBE) treatments result in a decrease in dry matter (DM) yield, whereas Glyphosate (GLY) herbicide resulted in a decrease in both total density (TD) and total legumes (TL) and Haloxyfop-R methyl (HAL) herbicide application resulted in an increase of total density (TD) and total legumes (TL) V relative to control plot. On phosphorus study, results suggest that at Phosphorus at 40 kg ha-1 (P40) fertilization dry matter (DM) yield will be increased and at both Phosphorus at 20 kg ha1 (P20) and Phosphorus at 40 kg ha-1 (P40) high total density (TD) will be recorded where’s Phosphorus at 20 kg ha-1 (P20) fertilization result in high total legumes (TL).
- Full Text:
- Date Issued: 2019
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
Evaluation of some Eastern beach bacteria for high activity laccase production
- Authors: Ntlatywa, Nonkolisi
- Date: 2019
- Subjects: Laccase
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/${Handle} , vital:40025
- Description: Laccases are multi-copper oxidases endowed with huge applicability and versatility. They are found in nature, fungi, insects, archaea and bacteria; however, there is a dearth of information regarding bacterial laccases. Thus, the search for novel bacterial laccases becomes crucial. Therefore, the broad aim of the study was the assessment of some bacteria on marine water isolated from Eastern beach for the production of high activity laccases. In this study, marine water samples obtained from the Eastern beach in East London were investigated for bacterial laccase-producing isolates. The samples were analysed using different microbiological media and varied substrates via qualitative methods. The isolates were tested for laccase activity using ABTS (2, 2’- azinobis 3-ethyl-benzothiazoline-6-sulphonate), as a substrate. The present study also dealt with the optimization of culture conditions for laccase production and characterization of laccase. A total of forty-eight (48) bacterial isolates were obtained, which were identified based on their morphological and cultural characteristics. Many of the isolates (42) were categorized as Gram positive and a few (6) as Gram negative upon subjecting to microscopic examination. Result showed that on average, laccase activity ranged from 5.33 – 6.5 U/L as demonstrated by three bacterial isolates (Bacillus sp. NFN1, Bacillus sp. NLN and Escherichia coli LO). Laccase production was highly enhanced by the supplementation with vanillic acid by Bacillus sp. strain NLN with yield of 15.83 ± 0.7 U/L, Bacillus sp. strain NFN1, 12.72 ± 0.21 U/L. However, Escherichia coli LO demonstrated enhanced laccase production with guaiacol (12.84 ± 1.12 U/L) followed by ferrulic acid (12.8 ± 0.36 U/L). While optimization results revealed that the laccase yield was enhanced under the following conditions: 72 h of incubation, pH 5, 0.5mg/L lactose as a carbon source, 1. 5 mg/L yeast extract as a nitrogen source as well as in the presence of corn stover and mandarin peels as lignocellulosic substrates depending on the bacteria.The time course and stability of laccase against temperature, pH, metal ions and organic solvents were investigated using previously described methods. In the findings obtained for the time course, the laccase activity ranged from 22.2- 23.98 U/L. In general, the optimum parameters for the optimum laccase activities depended on the bacterial isolates and the time of incubation and included 80 °C and 70 °C, pH 3 and 9 while, the thermal stability was over 100%. Overall, NaCl, ZnSO4, NiCl and 20% acetone demonstrated positive effect on the residual activity of the laccases of all the bacterial isolates (Bacillus sp. NFN1, Bacillus v sp. NLN and Escherichia coli LO). In conclusion the findings of the study, suggest that marine water of the Eastern beach is a rich source for laccase producing bacteria with potential of high activity.
- Full Text:
- Date Issued: 2019
- Authors: Ntlatywa, Nonkolisi
- Date: 2019
- Subjects: Laccase
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/${Handle} , vital:40025
- Description: Laccases are multi-copper oxidases endowed with huge applicability and versatility. They are found in nature, fungi, insects, archaea and bacteria; however, there is a dearth of information regarding bacterial laccases. Thus, the search for novel bacterial laccases becomes crucial. Therefore, the broad aim of the study was the assessment of some bacteria on marine water isolated from Eastern beach for the production of high activity laccases. In this study, marine water samples obtained from the Eastern beach in East London were investigated for bacterial laccase-producing isolates. The samples were analysed using different microbiological media and varied substrates via qualitative methods. The isolates were tested for laccase activity using ABTS (2, 2’- azinobis 3-ethyl-benzothiazoline-6-sulphonate), as a substrate. The present study also dealt with the optimization of culture conditions for laccase production and characterization of laccase. A total of forty-eight (48) bacterial isolates were obtained, which were identified based on their morphological and cultural characteristics. Many of the isolates (42) were categorized as Gram positive and a few (6) as Gram negative upon subjecting to microscopic examination. Result showed that on average, laccase activity ranged from 5.33 – 6.5 U/L as demonstrated by three bacterial isolates (Bacillus sp. NFN1, Bacillus sp. NLN and Escherichia coli LO). Laccase production was highly enhanced by the supplementation with vanillic acid by Bacillus sp. strain NLN with yield of 15.83 ± 0.7 U/L, Bacillus sp. strain NFN1, 12.72 ± 0.21 U/L. However, Escherichia coli LO demonstrated enhanced laccase production with guaiacol (12.84 ± 1.12 U/L) followed by ferrulic acid (12.8 ± 0.36 U/L). While optimization results revealed that the laccase yield was enhanced under the following conditions: 72 h of incubation, pH 5, 0.5mg/L lactose as a carbon source, 1. 5 mg/L yeast extract as a nitrogen source as well as in the presence of corn stover and mandarin peels as lignocellulosic substrates depending on the bacteria.The time course and stability of laccase against temperature, pH, metal ions and organic solvents were investigated using previously described methods. In the findings obtained for the time course, the laccase activity ranged from 22.2- 23.98 U/L. In general, the optimum parameters for the optimum laccase activities depended on the bacterial isolates and the time of incubation and included 80 °C and 70 °C, pH 3 and 9 while, the thermal stability was over 100%. Overall, NaCl, ZnSO4, NiCl and 20% acetone demonstrated positive effect on the residual activity of the laccases of all the bacterial isolates (Bacillus sp. NFN1, Bacillus v sp. NLN and Escherichia coli LO). In conclusion the findings of the study, suggest that marine water of the Eastern beach is a rich source for laccase producing bacteria with potential of high activity.
- Full Text:
- Date Issued: 2019
Extraction, isolation and characterization of oleanolic acid and its analogues from Syzygium aromaticum (cloves) and evaluation of their biological activities
- Authors: khwaza, Vuyolwethu
- Date: 2019
- Subjects: Antibacterial agents
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/19076 , vital:39882
- Description: Pathogenic microorganisms have serious impact on people's lives. Every year, millions of people around the world die of bacterial infections. Resistance to common antibacterial drugs has proven to be a challenging problem in control of bacterial infections. In an attempt to develop an effective and affordable treatment for bacterial infections, oleanolic acid isolated from syzygium aromaticum conjugates incorporating other pharmaceutical scaffolds such as chloroquine derivatives, curcumin, and ergocalciferol etc have been developed. Based on the previous successes of testing combination of antimicrobial drugs and pharmaceutical drugs which appeared to be the promising strategy to overcome treatment failure; a series of hybrid compounds containing oleanolic acid and other pharmaceutical scaffolds were synthesized. 4- Aminoquinoline derivatives were first hybridized with selected organic compounds to form a class of hybrid compounds containing either amide bond or ester bond as a linker between the precursor molecules. Analogues/hybrid compounds can overcome the disadvantages of combination therapy such as drug-drug interaction. The structural effects of this type of conjugation of oleanolic acid and other pharmaceutical scaffolds were characterised by FTIR, Mass Spec and NMR spectroscopy. These compounds were studied along with the monosubstituted oleanolic acid analogues and the organic components in order to compare the effects of the substitution on their biological response.‖ All the synthesized analogues were tested against 11 bacterial strains on both Gram-positive and Gram-negative bacteria. The synthesized compounds showed selectivity and higher activity against Enterococcus faecalis (EF), Klebsiella oxytoca (KO), Escherischia coli (EC), Staphylococcus aureous (SA), Proteus vulgaris (PV) and Bacillus subtilis (BS) with MIC values; ranging between of 1.25 mg/mL to 0.072 mg/mL
- Full Text:
- Date Issued: 2019
- Authors: khwaza, Vuyolwethu
- Date: 2019
- Subjects: Antibacterial agents
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/19076 , vital:39882
- Description: Pathogenic microorganisms have serious impact on people's lives. Every year, millions of people around the world die of bacterial infections. Resistance to common antibacterial drugs has proven to be a challenging problem in control of bacterial infections. In an attempt to develop an effective and affordable treatment for bacterial infections, oleanolic acid isolated from syzygium aromaticum conjugates incorporating other pharmaceutical scaffolds such as chloroquine derivatives, curcumin, and ergocalciferol etc have been developed. Based on the previous successes of testing combination of antimicrobial drugs and pharmaceutical drugs which appeared to be the promising strategy to overcome treatment failure; a series of hybrid compounds containing oleanolic acid and other pharmaceutical scaffolds were synthesized. 4- Aminoquinoline derivatives were first hybridized with selected organic compounds to form a class of hybrid compounds containing either amide bond or ester bond as a linker between the precursor molecules. Analogues/hybrid compounds can overcome the disadvantages of combination therapy such as drug-drug interaction. The structural effects of this type of conjugation of oleanolic acid and other pharmaceutical scaffolds were characterised by FTIR, Mass Spec and NMR spectroscopy. These compounds were studied along with the monosubstituted oleanolic acid analogues and the organic components in order to compare the effects of the substitution on their biological response.‖ All the synthesized analogues were tested against 11 bacterial strains on both Gram-positive and Gram-negative bacteria. The synthesized compounds showed selectivity and higher activity against Enterococcus faecalis (EF), Klebsiella oxytoca (KO), Escherischia coli (EC), Staphylococcus aureous (SA), Proteus vulgaris (PV) and Bacillus subtilis (BS) with MIC values; ranging between of 1.25 mg/mL to 0.072 mg/mL
- Full Text:
- Date Issued: 2019
Genetic detection of some tick-borne bacterial and protozoan pathogens in ticks collected in Raymond Mhlaba local municipality, Eastern Cape Province, South Africa
- Authors: Nqoro, Ayabulela
- Date: 2019
- Subjects: Tick-borne diseases Ticks
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17084 , vital:40846
- Description: Ticks and tick-borne diseases are becoming a major life threatening concern to wildlife, domesticated animals and human health. Besides causing skin damage, ticks infestations have become a growing burden in food security, economic losses and transmitting multides of pathogens. Little data and knowledge is available regarding the occurrence of etiologic agents of tick-borne diseases in the Eastern Cape of South Africa, hence the study was conducted and aimed at screening for genetic material of Anaplasma, Rickettisia, Ehrlichia, Borrelia, Babesia and Theileria species in ticks collected in Raymond Mhlaba District at Eastern Cape, South Africa. Ticks were collected from domesticated animals in Raymond Mhlaba Municipality, and were morphologically identified and processed for DNA extraction. Ticks were chopped into bits and DNA was extracted from the samples with commercial DNA extraction kit. The extracted DNA samples was used to molecularly identify the tick as well as assess the presence of tickborne pathogens belonging to Rickettsia, Babesia, Borrelia, Anaplasma and Erhlichia, and Theileria spp. by PCR using specific primer pairs published in literature. Positive amplicons were sequenced in a commercial sequencing facility. The obtained chromatograms were edited with Geneious bioinformatics software and were subjected to BLASTn and phylogenetic analyses using MEGA7 version for evolutionary relationships with curated reference sequences in GenBank. Nine hundred and sixty two tick samples were collected from domestic animals. Collected tick samples belonged to three genera, which were the Amblyomma, Rhipicephalus and Haemophalis in decreasing order of their abundance. Screening of tick DNA samples by PCR did not show presence of Babesia, Borrelia, Anaplasma and Erhlichia. 13 Positive PCR products were observed for Rickettsia and Theileria spp.. The positive amplicons were purified, sequenced and analysed for speciation of Theileria and Rickettsia. The presence of Rickettsia was detected in 60/994 (6%) from the three genera of ticks. Phylogenetic analyses shows that the sequences obtained are phylogenetically related to members of Spotted fever group Rickettsiae. Genetic material of Theileria spp. was detected from 10/994 ticks with an overall infection of 1% obtained in Rhipicephalus genera. Analyses shows that the sequences obtained are phylogenetically related to T. orientalis complex. The finding from this study therefore expands the knowledge on recent emergence of Theileria and Rickettsia spp. in Raymond Mhlaba Municipality in Eastern Cape, South Africa
- Full Text:
- Date Issued: 2019
- Authors: Nqoro, Ayabulela
- Date: 2019
- Subjects: Tick-borne diseases Ticks
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17084 , vital:40846
- Description: Ticks and tick-borne diseases are becoming a major life threatening concern to wildlife, domesticated animals and human health. Besides causing skin damage, ticks infestations have become a growing burden in food security, economic losses and transmitting multides of pathogens. Little data and knowledge is available regarding the occurrence of etiologic agents of tick-borne diseases in the Eastern Cape of South Africa, hence the study was conducted and aimed at screening for genetic material of Anaplasma, Rickettisia, Ehrlichia, Borrelia, Babesia and Theileria species in ticks collected in Raymond Mhlaba District at Eastern Cape, South Africa. Ticks were collected from domesticated animals in Raymond Mhlaba Municipality, and were morphologically identified and processed for DNA extraction. Ticks were chopped into bits and DNA was extracted from the samples with commercial DNA extraction kit. The extracted DNA samples was used to molecularly identify the tick as well as assess the presence of tickborne pathogens belonging to Rickettsia, Babesia, Borrelia, Anaplasma and Erhlichia, and Theileria spp. by PCR using specific primer pairs published in literature. Positive amplicons were sequenced in a commercial sequencing facility. The obtained chromatograms were edited with Geneious bioinformatics software and were subjected to BLASTn and phylogenetic analyses using MEGA7 version for evolutionary relationships with curated reference sequences in GenBank. Nine hundred and sixty two tick samples were collected from domestic animals. Collected tick samples belonged to three genera, which were the Amblyomma, Rhipicephalus and Haemophalis in decreasing order of their abundance. Screening of tick DNA samples by PCR did not show presence of Babesia, Borrelia, Anaplasma and Erhlichia. 13 Positive PCR products were observed for Rickettsia and Theileria spp.. The positive amplicons were purified, sequenced and analysed for speciation of Theileria and Rickettsia. The presence of Rickettsia was detected in 60/994 (6%) from the three genera of ticks. Phylogenetic analyses shows that the sequences obtained are phylogenetically related to members of Spotted fever group Rickettsiae. Genetic material of Theileria spp. was detected from 10/994 ticks with an overall infection of 1% obtained in Rhipicephalus genera. Analyses shows that the sequences obtained are phylogenetically related to T. orientalis complex. The finding from this study therefore expands the knowledge on recent emergence of Theileria and Rickettsia spp. in Raymond Mhlaba Municipality in Eastern Cape, South Africa
- Full Text:
- Date Issued: 2019
Grabcuts for image segmentation: a comparative study of clustering techniques
- Authors: Manzi, Nozuko Zuleika
- Date: 2019
- Subjects: Algorithms , Computer graphics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14494 , vital:39995
- Description: Image segmentation is the partitioning of a digital image into small segments such as pixels or sets of pixels. It is significant as it allows for the visualization of structures of interest, removing unnecessary information. In addition, image segmentation is used in many fields like, for instance healthcare for image surgery, construction, etc. as it enables structure analysis. Segmentation of images can be computationally expensive especially when a large dataset is used, thus the importance of fast and effective segmentation algorithms is realised. This method is used to locate objects and boundaries (i.e. foreground and background) in images. The aim of this study is to provide a comparison of clustering techniques that would allow the Grabcuts for image segmentation algorithm to be effective and inexpensive. The Grabcuts based method, which is an extension of the graph cut based method, has been instrumental in solving many problems in computer vision i.e. image restoration, image segmentation, object recognition, tracking and analysis. According to Ramirez,et.al [47], the Grabcuts approach is an iterative and minimal user interaction algorithm as it chooses a segmentation by iteratively revising the foreground and background pixels assignments. The method uses min-cut/ max-flow algorithm to segment digital images proposed by Boykov and Jolly [9]. The input of this approach is a digital image with a selected v region of interest (ROI). The ROI is selected using a rectangular bounding box. The pixels inside the bounding box are assigned to the foreground, while the others are assigned to the background. In this study, the Grabcuts for image segmentation algorithm designed by [48] with a Gaussian Mixture Model (GMM) based on the Kmeans and Kmedoids clustering techniques are developed and compared. In addition, the algorithms developed are allowed to run on the Central Processing Unit (CPU) under two scenarios. Scenario 1 involves allowing the Kmeans and Kmedoids clustering techniques to the Squared Euclidean distance measures to calculate the similarities and dissimilarities in pixels in an image. In scenario 2, the Kmeans and Kmedoids clustering techniques will use the City Block distance measure to calculate similarities as well as dissimilarities between pixels in a given image. The same images from the Berkeley Segmentation Dataset and Benchmark 500 were used as input to the algorithms and the number of clusters, K, was varied from 2 to 5. It was observed that the Kmeans clustering technique outperformed the Kmedoids clustering technique under the two scenarios for all the test images with K varied from 2 to 5, in terms of runtime required. In addition, the Kmeans clustering technique obtained more compact and separate clusters under scenario 1, than its counterpart. On the other hand, the Kmedoids obtained more compact and separate clusters than the Kmeans clustering technique under scenario 2. The silhouette validity index favoured the smallest number of clusters for both clustering techniques as it suggested the optimal number of clusters for the Kmeans and Kmedoids clustering techniques under the two scenarios was 2. Although the Kmeans required less computation time than vi its counterpart, the generation of foreground and background took longer for the GMM based on Kmeans than it did for the GMM based on Kmedoids clustering technique. Furthermore, the Grabcuts for image segmentation algorithm with a GMM based on the Kmedoids clustering technique was computationally less expensive than the Grabcuts for image segmentation algorithm with a GMM based on the Kmeans clustering technique. This was observed to be true under both scenario 1 and 2. The Grabcuts for image with the GMM based on the Kmeans clustering techniques obtained slightly better segmentation results when the visual quality is concerned, than its counterpart under the two scenarios considered. On the other hand, the BFscores showed that the Grabcuts for image segmentation algorithm with the GMM based on Kmedoids produces images with higher BF-scores than its counterpart when K was varied from 2 to 5 for most of the test images. In addition, most of the images obtained the majority of their best segmentation results when K=2. This was observed to be true under scenario 1 as well as scenario 2. Therefore, the Kmedoids clustering technique under scenario 2 with K=2 would be the best option for the segmentation of difficult images in BSDS500. This is due to its ability to generate GMMs and segment difficult images more efficiently (i.e. time complexity, higher BF-scores, more under segmented rather than over segmented images, inter alia.) while producing comparable visual segmentation results to those obtained by the Grabcuts for image segmentation: GMM-Kmeans.
- Full Text:
- Date Issued: 2019
- Authors: Manzi, Nozuko Zuleika
- Date: 2019
- Subjects: Algorithms , Computer graphics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14494 , vital:39995
- Description: Image segmentation is the partitioning of a digital image into small segments such as pixels or sets of pixels. It is significant as it allows for the visualization of structures of interest, removing unnecessary information. In addition, image segmentation is used in many fields like, for instance healthcare for image surgery, construction, etc. as it enables structure analysis. Segmentation of images can be computationally expensive especially when a large dataset is used, thus the importance of fast and effective segmentation algorithms is realised. This method is used to locate objects and boundaries (i.e. foreground and background) in images. The aim of this study is to provide a comparison of clustering techniques that would allow the Grabcuts for image segmentation algorithm to be effective and inexpensive. The Grabcuts based method, which is an extension of the graph cut based method, has been instrumental in solving many problems in computer vision i.e. image restoration, image segmentation, object recognition, tracking and analysis. According to Ramirez,et.al [47], the Grabcuts approach is an iterative and minimal user interaction algorithm as it chooses a segmentation by iteratively revising the foreground and background pixels assignments. The method uses min-cut/ max-flow algorithm to segment digital images proposed by Boykov and Jolly [9]. The input of this approach is a digital image with a selected v region of interest (ROI). The ROI is selected using a rectangular bounding box. The pixels inside the bounding box are assigned to the foreground, while the others are assigned to the background. In this study, the Grabcuts for image segmentation algorithm designed by [48] with a Gaussian Mixture Model (GMM) based on the Kmeans and Kmedoids clustering techniques are developed and compared. In addition, the algorithms developed are allowed to run on the Central Processing Unit (CPU) under two scenarios. Scenario 1 involves allowing the Kmeans and Kmedoids clustering techniques to the Squared Euclidean distance measures to calculate the similarities and dissimilarities in pixels in an image. In scenario 2, the Kmeans and Kmedoids clustering techniques will use the City Block distance measure to calculate similarities as well as dissimilarities between pixels in a given image. The same images from the Berkeley Segmentation Dataset and Benchmark 500 were used as input to the algorithms and the number of clusters, K, was varied from 2 to 5. It was observed that the Kmeans clustering technique outperformed the Kmedoids clustering technique under the two scenarios for all the test images with K varied from 2 to 5, in terms of runtime required. In addition, the Kmeans clustering technique obtained more compact and separate clusters under scenario 1, than its counterpart. On the other hand, the Kmedoids obtained more compact and separate clusters than the Kmeans clustering technique under scenario 2. The silhouette validity index favoured the smallest number of clusters for both clustering techniques as it suggested the optimal number of clusters for the Kmeans and Kmedoids clustering techniques under the two scenarios was 2. Although the Kmeans required less computation time than vi its counterpart, the generation of foreground and background took longer for the GMM based on Kmeans than it did for the GMM based on Kmedoids clustering technique. Furthermore, the Grabcuts for image segmentation algorithm with a GMM based on the Kmedoids clustering technique was computationally less expensive than the Grabcuts for image segmentation algorithm with a GMM based on the Kmeans clustering technique. This was observed to be true under both scenario 1 and 2. The Grabcuts for image with the GMM based on the Kmeans clustering techniques obtained slightly better segmentation results when the visual quality is concerned, than its counterpart under the two scenarios considered. On the other hand, the BFscores showed that the Grabcuts for image segmentation algorithm with the GMM based on Kmedoids produces images with higher BF-scores than its counterpart when K was varied from 2 to 5 for most of the test images. In addition, most of the images obtained the majority of their best segmentation results when K=2. This was observed to be true under scenario 1 as well as scenario 2. Therefore, the Kmedoids clustering technique under scenario 2 with K=2 would be the best option for the segmentation of difficult images in BSDS500. This is due to its ability to generate GMMs and segment difficult images more efficiently (i.e. time complexity, higher BF-scores, more under segmented rather than over segmented images, inter alia.) while producing comparable visual segmentation results to those obtained by the Grabcuts for image segmentation: GMM-Kmeans.
- Full Text:
- Date Issued: 2019
Isolation and characterization of extracts of Rosmarinus officinalis l. And comparative evaluation of its antimicrobial activity and selected types of antibiotics against some bacteria species
- Authors: Gbede,Remi
- Date: 2019
- Subjects: Rosmarinus Essences and essential oils Lamiaceae Medicinal plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/19142 , vital:39875
- Description: Rosmarinus officinalis L. is known extensively for its multifunctional purposes. The essential oil has been widely used in cosmeceuticals and several ethnopharmacological values. In vitro studies have demonstrated the antibacterial activity of essential oils (EOs) of Rosmarinus officinalis L. against Staphylococcus aureus ATCC 25923, Vibrio cholerae DSM 19283, Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 27853 and Bacillus cereus. These different bacteria were screened against antibiotics such as Tetracycline, Ampicillin Sodium salt, Erythromycin and Amoxicillin, and some standards namely rosmarinic acid, carnosic acid and carnosol, and also against the methanol, acetone, chloroform and dichloromethane extracts of rosemary. The essential oils of Rosmarinus officinalis L. showed significant inhibitory properties compared to antibiotics with various degrees of growth inhibition. The standards exhibited some activities against the organisms. The GC/MS analysis of the essential oil revealed 34 compounds present with most components acting in synergy to bring about antibacterial activities. The antiplasmodial and cytotoxic activities of two leaf extracts of Rosmarinus officinalis (with hexane and dichloromethane as solvents) using standard procedure were studied. The findings justify the claims on the efficacy of plants for therapeutic uses for antifungal, antibacterial and anti-inflammatory properties. Antiplasmodial activity of Rosmarinus officinalis recorded IC50 values of 9.99 µg/ml and 9.76 µg/ml in hexane and dichloromethane respectively.
- Full Text:
- Date Issued: 2019
- Authors: Gbede,Remi
- Date: 2019
- Subjects: Rosmarinus Essences and essential oils Lamiaceae Medicinal plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/19142 , vital:39875
- Description: Rosmarinus officinalis L. is known extensively for its multifunctional purposes. The essential oil has been widely used in cosmeceuticals and several ethnopharmacological values. In vitro studies have demonstrated the antibacterial activity of essential oils (EOs) of Rosmarinus officinalis L. against Staphylococcus aureus ATCC 25923, Vibrio cholerae DSM 19283, Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 27853 and Bacillus cereus. These different bacteria were screened against antibiotics such as Tetracycline, Ampicillin Sodium salt, Erythromycin and Amoxicillin, and some standards namely rosmarinic acid, carnosic acid and carnosol, and also against the methanol, acetone, chloroform and dichloromethane extracts of rosemary. The essential oils of Rosmarinus officinalis L. showed significant inhibitory properties compared to antibiotics with various degrees of growth inhibition. The standards exhibited some activities against the organisms. The GC/MS analysis of the essential oil revealed 34 compounds present with most components acting in synergy to bring about antibacterial activities. The antiplasmodial and cytotoxic activities of two leaf extracts of Rosmarinus officinalis (with hexane and dichloromethane as solvents) using standard procedure were studied. The findings justify the claims on the efficacy of plants for therapeutic uses for antifungal, antibacterial and anti-inflammatory properties. Antiplasmodial activity of Rosmarinus officinalis recorded IC50 values of 9.99 µg/ml and 9.76 µg/ml in hexane and dichloromethane respectively.
- Full Text:
- Date Issued: 2019
Mapping soil factors influencing erosion using machine leaerning algorithms in the t35 d-e catchment in the Eastern Cape Province
- Du Plessis, Casparus Jacobus
- Authors: Du Plessis, Casparus Jacobus
- Date: 2019
- Subjects: Soils -- Analysis Soil erosion
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17106 , vital:40850
- Description: The need for detailed spatial soil information is increasing in the fields of environmental studies, agriculture as well as engineering practices. Regarding soil erosion in South Africa, border lines between sensitive soil forms in the Duplex soil group and resistant soil forms in the Oxidic soil group need to be mapped to a high accuracy to prevent/manage erosion and major soil losses. In third world countries like South Africa, digital soil mapping (DSM) with the use of machine learning can provide the solutions to fill numerous gaps in these related fields. Local DSM research has been ongoing at the University of the Free State and related institutions for the past eleven years. It has also been used commercially and can therefore be regarded as fruitful. The National Resource Management unit of the Department of Environmental Affairs required a soil map regarding the susceptibility of the soil to erosion for catchment T35 D-E (87 000 hectares) in the Mzimvubu management area of the Eastern Cape, South Africa. Through a DSM approach, machine learning was used to predict the occurrence of soil forms and soil families in accordance with the South African Soil Classification System. A total of 591 soil observations were made at specific points, pre-determined with the conditioned Latin Hypercube sampling (cLHS) method. These pre-determined points were classified into nineteen soil forms and forty eight soil families. The soils were then further divided into nine soil groups, based on their inherent sensitivity to erosion. Outlier observations were omitted from the dataset to create a reliable framework to predict the soil groups as influenced by the SCORPAN factors. These soil groups were mapped and evaluated with an accuracy of 68% and a Kappa statistic value of 0.42 that compare well with other soil maps, both locally and internationally. Mapping soil with an acceptable accuracy with such a high level of detail on catchment scale would be a tremendous advantage to soil scientists and environmental workforces in southern Africa. Future work should focus on DSM training, to broaden the base of DSM skills available in southern Africa. This will ensure that soil information would be included in addressing an increasing amount of real world problems at catchment scales.
- Full Text:
- Date Issued: 2019
- Authors: Du Plessis, Casparus Jacobus
- Date: 2019
- Subjects: Soils -- Analysis Soil erosion
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17106 , vital:40850
- Description: The need for detailed spatial soil information is increasing in the fields of environmental studies, agriculture as well as engineering practices. Regarding soil erosion in South Africa, border lines between sensitive soil forms in the Duplex soil group and resistant soil forms in the Oxidic soil group need to be mapped to a high accuracy to prevent/manage erosion and major soil losses. In third world countries like South Africa, digital soil mapping (DSM) with the use of machine learning can provide the solutions to fill numerous gaps in these related fields. Local DSM research has been ongoing at the University of the Free State and related institutions for the past eleven years. It has also been used commercially and can therefore be regarded as fruitful. The National Resource Management unit of the Department of Environmental Affairs required a soil map regarding the susceptibility of the soil to erosion for catchment T35 D-E (87 000 hectares) in the Mzimvubu management area of the Eastern Cape, South Africa. Through a DSM approach, machine learning was used to predict the occurrence of soil forms and soil families in accordance with the South African Soil Classification System. A total of 591 soil observations were made at specific points, pre-determined with the conditioned Latin Hypercube sampling (cLHS) method. These pre-determined points were classified into nineteen soil forms and forty eight soil families. The soils were then further divided into nine soil groups, based on their inherent sensitivity to erosion. Outlier observations were omitted from the dataset to create a reliable framework to predict the soil groups as influenced by the SCORPAN factors. These soil groups were mapped and evaluated with an accuracy of 68% and a Kappa statistic value of 0.42 that compare well with other soil maps, both locally and internationally. Mapping soil with an acceptable accuracy with such a high level of detail on catchment scale would be a tremendous advantage to soil scientists and environmental workforces in southern Africa. Future work should focus on DSM training, to broaden the base of DSM skills available in southern Africa. This will ensure that soil information would be included in addressing an increasing amount of real world problems at catchment scales.
- Full Text:
- Date Issued: 2019
Multi-temporal assessment of chlorophyll-a concentration in estuarine waters: a case study of sundays and swartkops estuaries, Eastern Cape Province
- Authors: Gwazani, Nothando
- Date: 2019
- Subjects: Chlorophyll -- South Africa Estuaries -- South Africa
- Language: English
- Type: Thesis , Masters , MSc (Applied Remote Sensing & GIS)
- Identifier: http://hdl.handle.net/10353/11972 , vital:39123
- Description: Estuaries are productive and delicate marine systems, which are of commercial, recreational and aesthetic value as they reflect the land use of a catchment by creating “nutrient traps”, these nutrients are absorbed by water and later released into the coastal oceans. Disturbances in an estuary influence a wide variety of habitats and organisms in a marine ecosystem, for example, high chlorophyll-a affects marine species that utilize calm waters, food and turbid water found in estuaries. The degradation of South African estuaries is an on-going accelerating process; therefore, there is a need for preservation measures for estuarine ecosystems by means of monitoring nutrient flow. This research was aimed at assessing the use of OLCI ocean color products in monitoring chl-a concentration and impacts of the estuaries in Algoa Bay. OLCI on the Sentinel platforms, coupled with OCNN and OC4ME algorithms were employed to assess the distribution of chlorophyll-a in Swartkops and Sunday’s estuaries. OC4Me and OCNN are the default models designed for OLCI data. However, the OLCI resolution was not able to measure the chl-a concentration within these estuaries. Therefore, satellite product assessment was primarily focused on the Algoa bay scale due to the resolution of the available data. SNAP and Matlab were applied for the production of the final products. Accuracy assessment was used to check the agreement between the in situ datasets of chl-a and the final processed satellite products. Results of this investigation point that OCNN did not perform well in the study as compared to OC4Me and it did not produce accurate results in areas with very high biomass concentration. The research concludes by recommending the use of higher resolution data such as Sentinel 2 MSI (10m, 20m, and 60m resolution) for resolving chlorophyll-a within these estuaries.
- Full Text:
- Date Issued: 2019
- Authors: Gwazani, Nothando
- Date: 2019
- Subjects: Chlorophyll -- South Africa Estuaries -- South Africa
- Language: English
- Type: Thesis , Masters , MSc (Applied Remote Sensing & GIS)
- Identifier: http://hdl.handle.net/10353/11972 , vital:39123
- Description: Estuaries are productive and delicate marine systems, which are of commercial, recreational and aesthetic value as they reflect the land use of a catchment by creating “nutrient traps”, these nutrients are absorbed by water and later released into the coastal oceans. Disturbances in an estuary influence a wide variety of habitats and organisms in a marine ecosystem, for example, high chlorophyll-a affects marine species that utilize calm waters, food and turbid water found in estuaries. The degradation of South African estuaries is an on-going accelerating process; therefore, there is a need for preservation measures for estuarine ecosystems by means of monitoring nutrient flow. This research was aimed at assessing the use of OLCI ocean color products in monitoring chl-a concentration and impacts of the estuaries in Algoa Bay. OLCI on the Sentinel platforms, coupled with OCNN and OC4ME algorithms were employed to assess the distribution of chlorophyll-a in Swartkops and Sunday’s estuaries. OC4Me and OCNN are the default models designed for OLCI data. However, the OLCI resolution was not able to measure the chl-a concentration within these estuaries. Therefore, satellite product assessment was primarily focused on the Algoa bay scale due to the resolution of the available data. SNAP and Matlab were applied for the production of the final products. Accuracy assessment was used to check the agreement between the in situ datasets of chl-a and the final processed satellite products. Results of this investigation point that OCNN did not perform well in the study as compared to OC4Me and it did not produce accurate results in areas with very high biomass concentration. The research concludes by recommending the use of higher resolution data such as Sentinel 2 MSI (10m, 20m, and 60m resolution) for resolving chlorophyll-a within these estuaries.
- Full Text:
- Date Issued: 2019
Muscle nanostructure and physicochemical characteristics of South African A and AB mutton classes
- Authors: Mdikili, Zizipho
- Date: 2019
- Subjects: Meat -- Quality -- South Africa
- Language: English
- Type: Thesis , Masters , (MSc) (Animal Science)
- Identifier: http://hdl.handle.net/10353/12005 , vital:39126
- Description: Significant variations exist in quality of red meat due to the effect of various intrinsic and extrinsic factors. Research has been conducted in early 1990s to prove that carcasses from A and AB classes differ in meat quality due to age variation. This led to a conclusion that the two should be separated in the South African Red meat Classification System (SARCS). However, an interesting debate arose from a carcass classification workshop that A and AB meat classes have the same quality and thus must be integrated into one class in the carcass classification system. In addition, as much as it can be debated that these classes have the same quality, it is also possible that slight differences exist between the two since they are from different age groups. The current study was therefore developed and two trials were conducted to evaluate the impact of age differences on physicochemical attributes and muscle nanostructure of A and AB classes in sheep. In the first trial a total of ninety (n=90) Dorper sheep of the same sex but different age groups slaughtered at a high throughput abattoir in the Eastern Cape province were used to evaluate meat ultimate pH (pH24), colour (L* , a* , b* , H* , C* ), thawing loss (TL%), cooking loss (CL%) and tenderness (Warner Bratzler Shear Force - WBSF) of A and AB classes, whereas, on the second trial forty (n=40) Dorper sheep were used to evaluate muscle nanostructure and its relationship with tenderness. Meat samples were harvested from the Muscularis longissimuss thoracis et lumborum (LTL) for v meat quality and nanostructure measurements. The results showed significant variations (P<0.05) between the two classes for lean a* , H* and CL%. Significant differences (P<0.01) were observed in pH24, TL% and WBSF between A and AB classes. However, there were no significant differences (P>0.05) observed in meat L*, b* and C * . Ultimate pH was negatively correlated with thawing loss and some colorimetric attributes of lamb such as lightness, yellowness and hue angle. Moreover, tenderness was positively correlated with cooking and thawing losses. Significant differences were not (P>0.05) observed in sarcomere length, myofibrilar diameter and shear force between A and AB classes. Both sarcomere length and myofibrilar diameter were not correlated (P>0.05) with meat tenderness. These results suggest that A and AB classes are the same in nanostructure and that muscle nanostructure of these two classes is not related to meat tenderness. It was concluded that meat from sheep carcasses falling under the A and AB classes in the South African classification system vary greatly in physicochemical quality. Moreover, sheep carcasses from A and AB classes have the same sarcomere lengths and hence, they do not differ in meat tenderness (WBSF). However, when these classes were observed under a microscope, slight differences were noted in sarcomere lengths and myofibrilar diameters, which led to a conclusion that the two should remain as separated classes because their combination would result in the expansion of the non-uniformity of red meat tenderness. Therefore, A and AB classes should not be combined in the South African classification system. Further research is, however, recommended to evaluate the influence of other factors that were not examined in the current study.
- Full Text:
- Date Issued: 2019
- Authors: Mdikili, Zizipho
- Date: 2019
- Subjects: Meat -- Quality -- South Africa
- Language: English
- Type: Thesis , Masters , (MSc) (Animal Science)
- Identifier: http://hdl.handle.net/10353/12005 , vital:39126
- Description: Significant variations exist in quality of red meat due to the effect of various intrinsic and extrinsic factors. Research has been conducted in early 1990s to prove that carcasses from A and AB classes differ in meat quality due to age variation. This led to a conclusion that the two should be separated in the South African Red meat Classification System (SARCS). However, an interesting debate arose from a carcass classification workshop that A and AB meat classes have the same quality and thus must be integrated into one class in the carcass classification system. In addition, as much as it can be debated that these classes have the same quality, it is also possible that slight differences exist between the two since they are from different age groups. The current study was therefore developed and two trials were conducted to evaluate the impact of age differences on physicochemical attributes and muscle nanostructure of A and AB classes in sheep. In the first trial a total of ninety (n=90) Dorper sheep of the same sex but different age groups slaughtered at a high throughput abattoir in the Eastern Cape province were used to evaluate meat ultimate pH (pH24), colour (L* , a* , b* , H* , C* ), thawing loss (TL%), cooking loss (CL%) and tenderness (Warner Bratzler Shear Force - WBSF) of A and AB classes, whereas, on the second trial forty (n=40) Dorper sheep were used to evaluate muscle nanostructure and its relationship with tenderness. Meat samples were harvested from the Muscularis longissimuss thoracis et lumborum (LTL) for v meat quality and nanostructure measurements. The results showed significant variations (P<0.05) between the two classes for lean a* , H* and CL%. Significant differences (P<0.01) were observed in pH24, TL% and WBSF between A and AB classes. However, there were no significant differences (P>0.05) observed in meat L*, b* and C * . Ultimate pH was negatively correlated with thawing loss and some colorimetric attributes of lamb such as lightness, yellowness and hue angle. Moreover, tenderness was positively correlated with cooking and thawing losses. Significant differences were not (P>0.05) observed in sarcomere length, myofibrilar diameter and shear force between A and AB classes. Both sarcomere length and myofibrilar diameter were not correlated (P>0.05) with meat tenderness. These results suggest that A and AB classes are the same in nanostructure and that muscle nanostructure of these two classes is not related to meat tenderness. It was concluded that meat from sheep carcasses falling under the A and AB classes in the South African classification system vary greatly in physicochemical quality. Moreover, sheep carcasses from A and AB classes have the same sarcomere lengths and hence, they do not differ in meat tenderness (WBSF). However, when these classes were observed under a microscope, slight differences were noted in sarcomere lengths and myofibrilar diameters, which led to a conclusion that the two should remain as separated classes because their combination would result in the expansion of the non-uniformity of red meat tenderness. Therefore, A and AB classes should not be combined in the South African classification system. Further research is, however, recommended to evaluate the influence of other factors that were not examined in the current study.
- Full Text:
- Date Issued: 2019
Nutritional and pharmacological profile of moringa oleifera lam. Leaves cultivated in the South African ecotype
- Authors: Yako, Zomsa
- Date: 2019
- Subjects: Moringa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14605 , vital:40021
- Description: Moringa oleifera Lam. is native to the Indian ecotype, which has become naturalized in many tropic and subtropic regions worldwide, thus a great variation in the bioactive compounds of the plant is recorded. The introduction of Moringa oleifera to South Africa occurred in the turn of the twentieth century with the aim of combating malnourishment, aiding health and fostering economic development. Therefore, this study was conducted with the aim of evaluating and authenticating the nutritional parameters, essential oil and bioactive components found in the various solvent extracts of Moringa oleifera leaves cultivated in the South African ecotype. It also elucidated some of the plants medicinal properties by investigating the antioxidant and antibacterial properties of the plant. The essential oil of the leaves was extracted using two methods (solvent free microwave extraction and hydrodistillation) and analysed using Gas Chromotography/Mass Spectrometer. The safety profile of the leaves was investigated using brine shrimp model. The results from the study revealed that Moringa oleifera leaves cultivated in South Africa were rich in crude protein levels (28.72%) and carbohydrate (28.84%). Among the minerals tested for, the leaves contained high content of calcium (1603.33 mg/100 g), potassium (1690 mg/100 g), zinc (13.03 mg/100 g) and iron (21.13 mg/100 g). The vitamin E content had the highest concentration (89.43 mg/100 g) among the vitamins evaluated. The leaves of Moringa oleifera had low quantities of antinutrients in relation to minerals, thus ensuring nutrients availability. This study identified 15 fatty acids in the dried leaves of Moringa. The highest fatty acid detected were polyunsaturated fatty acids, linoleic acid (56.36) and alpha-linolenic acid (687.58), 7 of the fatty acids were saturated fatty acids, though relatively low besides stearic acid. 15 amino acids were present, 7 of which were essential amino acids, namely; threonine, tyrosine, methionine, valine, phenylalanine, isoleucine and leucine. vi Among the phytochemicals evaluated, the aqueous extract gave the highest total phenolic content (21.01 ± 2.315 mg GAE/g), the acetone extract gave the highest proanthocyanidin (15.33 3.5 mg CE/g) and flavonoid contents (25.04±3.28 mg QE/g), while saponin and alkaloid contents were 27.73 ± 9.97% and 7.32 ± 2.73 % respectively. All the extracts exhibited high radical scavenging power against the 2,2- diphenyl-1-picrylhydrazyl radical with an IC50 less than 0.025 mg/mL. Aqueous extract gave the highest capacity based on ABTS and TAC assays with IC50 of 0.074 mg/ mL and 0.055 mg/mL respectively. Ethanol extract exhibited the least antioxidant capacity among the extracts, as well as the least antimicrobial activity on both Gram −ve and Gram +ve bacteria with all its minimum inhibitory concentration values greater than 5 mg/mL. The acetone extract exhibited the strongest antimicrobial activity among the extracts. A total of 8 and 24 chemical compounds were found from the solvent-free microwave extracted and hydrodistilled oils, respectively. The major components found from hydrodistillation were 2-Hexanal (16.37%), Nonanal (6.09%), 5 9-undecadien-2-one 6, 10 dimethyl- (e) - (8.01%), trans-beta-Ionone (8.02%) and octadecane (9.67%). For the solvent free microwave extracted oil, Benzene acetaldehyde (5.68%), Octadecane, Pentacosane and Eicosane which were 11.03%, were the major components. Toxicity evaluation revealed that mortality was time dependent. As the exposure period increased, mortality kept increasing. The hatching success of the cysts in acetone, aqueous and ethanol extracts were 35.7, 33.6 and 35.2% respectively. Acetone extract showed the most prominent hatching success. Hatchability and lethality were in a concentration dependent fashion. Among the extracts, acetone extract exhibited the highest lethality (12.3%) to the nauplii, followed by ethanol (10.9%), then aqueous (5.6%) extracts. All the results obtained from this study suggest that Moringa has the potential of eradicating malnutrition and aid health. It contains the necessary nutritional and bioactive compounds and the leaves proved not to be toxic at the levels (0.0625 – 1 mg/mL) tested.
- Full Text:
- Date Issued: 2019
- Authors: Yako, Zomsa
- Date: 2019
- Subjects: Moringa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14605 , vital:40021
- Description: Moringa oleifera Lam. is native to the Indian ecotype, which has become naturalized in many tropic and subtropic regions worldwide, thus a great variation in the bioactive compounds of the plant is recorded. The introduction of Moringa oleifera to South Africa occurred in the turn of the twentieth century with the aim of combating malnourishment, aiding health and fostering economic development. Therefore, this study was conducted with the aim of evaluating and authenticating the nutritional parameters, essential oil and bioactive components found in the various solvent extracts of Moringa oleifera leaves cultivated in the South African ecotype. It also elucidated some of the plants medicinal properties by investigating the antioxidant and antibacterial properties of the plant. The essential oil of the leaves was extracted using two methods (solvent free microwave extraction and hydrodistillation) and analysed using Gas Chromotography/Mass Spectrometer. The safety profile of the leaves was investigated using brine shrimp model. The results from the study revealed that Moringa oleifera leaves cultivated in South Africa were rich in crude protein levels (28.72%) and carbohydrate (28.84%). Among the minerals tested for, the leaves contained high content of calcium (1603.33 mg/100 g), potassium (1690 mg/100 g), zinc (13.03 mg/100 g) and iron (21.13 mg/100 g). The vitamin E content had the highest concentration (89.43 mg/100 g) among the vitamins evaluated. The leaves of Moringa oleifera had low quantities of antinutrients in relation to minerals, thus ensuring nutrients availability. This study identified 15 fatty acids in the dried leaves of Moringa. The highest fatty acid detected were polyunsaturated fatty acids, linoleic acid (56.36) and alpha-linolenic acid (687.58), 7 of the fatty acids were saturated fatty acids, though relatively low besides stearic acid. 15 amino acids were present, 7 of which were essential amino acids, namely; threonine, tyrosine, methionine, valine, phenylalanine, isoleucine and leucine. vi Among the phytochemicals evaluated, the aqueous extract gave the highest total phenolic content (21.01 ± 2.315 mg GAE/g), the acetone extract gave the highest proanthocyanidin (15.33 3.5 mg CE/g) and flavonoid contents (25.04±3.28 mg QE/g), while saponin and alkaloid contents were 27.73 ± 9.97% and 7.32 ± 2.73 % respectively. All the extracts exhibited high radical scavenging power against the 2,2- diphenyl-1-picrylhydrazyl radical with an IC50 less than 0.025 mg/mL. Aqueous extract gave the highest capacity based on ABTS and TAC assays with IC50 of 0.074 mg/ mL and 0.055 mg/mL respectively. Ethanol extract exhibited the least antioxidant capacity among the extracts, as well as the least antimicrobial activity on both Gram −ve and Gram +ve bacteria with all its minimum inhibitory concentration values greater than 5 mg/mL. The acetone extract exhibited the strongest antimicrobial activity among the extracts. A total of 8 and 24 chemical compounds were found from the solvent-free microwave extracted and hydrodistilled oils, respectively. The major components found from hydrodistillation were 2-Hexanal (16.37%), Nonanal (6.09%), 5 9-undecadien-2-one 6, 10 dimethyl- (e) - (8.01%), trans-beta-Ionone (8.02%) and octadecane (9.67%). For the solvent free microwave extracted oil, Benzene acetaldehyde (5.68%), Octadecane, Pentacosane and Eicosane which were 11.03%, were the major components. Toxicity evaluation revealed that mortality was time dependent. As the exposure period increased, mortality kept increasing. The hatching success of the cysts in acetone, aqueous and ethanol extracts were 35.7, 33.6 and 35.2% respectively. Acetone extract showed the most prominent hatching success. Hatchability and lethality were in a concentration dependent fashion. Among the extracts, acetone extract exhibited the highest lethality (12.3%) to the nauplii, followed by ethanol (10.9%), then aqueous (5.6%) extracts. All the results obtained from this study suggest that Moringa has the potential of eradicating malnutrition and aid health. It contains the necessary nutritional and bioactive compounds and the leaves proved not to be toxic at the levels (0.0625 – 1 mg/mL) tested.
- Full Text:
- Date Issued: 2019
Perceptions of climate change and adaptation strategies: the case of smallholder farmers of Raymond Mhlaba, Port Saint Johns’ and Ingquza Hill local municipality in the Eastern Cape.
- Authors: Maya, Okuhle
- Date: 2019
- Subjects: Climatic changes Farms, Small
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17271 , vital:40871
- Description: Climate change has become indisputable judging from the observed global variations in precipitation, increases in average temperatures, rising average sea levels and melting of ice. The climate phenomenon has since evolved globally and it has been largely documented by scholars. Because of the increases in global temperatures, weather patterns have also changed. This change has resulted in debates on climate change as well as how to respond to it. Various scholars across the world have expressed their opinions about climate change; its causes, impacts and adaptation. In addition, there has been a growing body of literature and studies focusing on smallholder farmers’ perceptions of climate change. Without a doubt, climate change will and has left a group of people, communities and countries vulnerable. In particular, developing countries and poor communities in sub-Saharan Africa are expected to be affected the most by the impacts of climate change. This is mainly because of the region’s dependence on natural resources and their limited capacity to adapt. Literature further adds that vulnerability is on condition of the community’s socioeconomic characteristics and physical surroundings. Climate change variations pose a threat to the agricultural sector and food security of households relying on subsistence farming for survival. Climate variations such as decrease in rainfall and increased hot seasons have been reported to have led to a decline in food production, death of livestock and outbreaks human and animal diseases. The study’s main aim was to determine the smallholder farmers’ perceptions of climate change and adaptation strategies in Raymond Mhlaba, Port Saint Johns’ and Ingquza Hill local municipalities. Particularly, the study looked at the factors influencing these perceptions and the factors affecting the smallholder farmers’ choice of adaptation strategies used in response to climate change. Investigating perception provides insights into the fundamental drivers of behavioural changes in the face of climate change. On their part, adaptation options are greatly shaped by the nature of an individual’s behaviour. The study was carried out in 3 local municipalities (Raymond Mhlaba, Port St Johns’ and Ingquza Hill) in the Eastern Cape, South Africa. The research design applied in this study was cross sectional design where data are collected at a single point in time. Multistage sampling technique was used in selecting respondents from the local municipalities. Stratification was then done to group farmers according to their vi wards and locations. Lastly, purposive sampling was used to select households and smallholder farmers practising crop and livestock production. A total of 211 smallholder farmers constituted the sample size for the study. A close-ended questionnaire was used to conduct structured interviews of household heads. The study utilized both qualitative and quantitative approach. Data collected were coded and entered in Microsoft Excel and transferred to Statistical Package for Social Scientists (SPSS, version 25) for analyses. Descriptive statistics was used to determine the climate change perceptions of smallholder farmers and also to explore the adaptation strategies used by farmers to cope with the impacts of climate change. The findings were explained using frequencies, means and variances. Multinomial Logistic Regression (MNL) was used to determine the factors affecting the choice of adaptation strategies used by smallholder farmers and the probability that a farmer would choose a particular strategy. The results from the study revealed most of the respondents as being able to identify the perceived changes in climate with the environmental changes that they observed. The respondents perceived climate change as an increase in drought period, increase in average temperatures, decrease and variations in rainfall, shortened growing season, crop failure, pests and diseases. However, most of the smallholder farmers disagreed with the frequency of flood incidences as they have not experienced these in their areas. In terms of responses to these changes in climate, the smallholder farmers have used a number of adaptation strategies to cope. Most of the farmers used crop diversification, organic manure, soil and water conservation practices, while others simply did not adapt and some used all the available adaptation strategies identified in this study. The results from the MNL revealed that occupation, household size and years spent in school (education) generally had a positive influence on the choice of adaptation strategy used by smallholder farmers. On the other hand, age; farming systems and membership of a farmers’ association were negatively affecting the smallholder farmers’ choice of adaptation strategy to use in response to climate change. Much support is needed in terms of disseminating information and knowledge among smallholder farmers about climate change and its adaptation strategies. This can be possible through improving extension services, and providing credit to smallholder farmers
- Full Text:
- Date Issued: 2019
- Authors: Maya, Okuhle
- Date: 2019
- Subjects: Climatic changes Farms, Small
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17271 , vital:40871
- Description: Climate change has become indisputable judging from the observed global variations in precipitation, increases in average temperatures, rising average sea levels and melting of ice. The climate phenomenon has since evolved globally and it has been largely documented by scholars. Because of the increases in global temperatures, weather patterns have also changed. This change has resulted in debates on climate change as well as how to respond to it. Various scholars across the world have expressed their opinions about climate change; its causes, impacts and adaptation. In addition, there has been a growing body of literature and studies focusing on smallholder farmers’ perceptions of climate change. Without a doubt, climate change will and has left a group of people, communities and countries vulnerable. In particular, developing countries and poor communities in sub-Saharan Africa are expected to be affected the most by the impacts of climate change. This is mainly because of the region’s dependence on natural resources and their limited capacity to adapt. Literature further adds that vulnerability is on condition of the community’s socioeconomic characteristics and physical surroundings. Climate change variations pose a threat to the agricultural sector and food security of households relying on subsistence farming for survival. Climate variations such as decrease in rainfall and increased hot seasons have been reported to have led to a decline in food production, death of livestock and outbreaks human and animal diseases. The study’s main aim was to determine the smallholder farmers’ perceptions of climate change and adaptation strategies in Raymond Mhlaba, Port Saint Johns’ and Ingquza Hill local municipalities. Particularly, the study looked at the factors influencing these perceptions and the factors affecting the smallholder farmers’ choice of adaptation strategies used in response to climate change. Investigating perception provides insights into the fundamental drivers of behavioural changes in the face of climate change. On their part, adaptation options are greatly shaped by the nature of an individual’s behaviour. The study was carried out in 3 local municipalities (Raymond Mhlaba, Port St Johns’ and Ingquza Hill) in the Eastern Cape, South Africa. The research design applied in this study was cross sectional design where data are collected at a single point in time. Multistage sampling technique was used in selecting respondents from the local municipalities. Stratification was then done to group farmers according to their vi wards and locations. Lastly, purposive sampling was used to select households and smallholder farmers practising crop and livestock production. A total of 211 smallholder farmers constituted the sample size for the study. A close-ended questionnaire was used to conduct structured interviews of household heads. The study utilized both qualitative and quantitative approach. Data collected were coded and entered in Microsoft Excel and transferred to Statistical Package for Social Scientists (SPSS, version 25) for analyses. Descriptive statistics was used to determine the climate change perceptions of smallholder farmers and also to explore the adaptation strategies used by farmers to cope with the impacts of climate change. The findings were explained using frequencies, means and variances. Multinomial Logistic Regression (MNL) was used to determine the factors affecting the choice of adaptation strategies used by smallholder farmers and the probability that a farmer would choose a particular strategy. The results from the study revealed most of the respondents as being able to identify the perceived changes in climate with the environmental changes that they observed. The respondents perceived climate change as an increase in drought period, increase in average temperatures, decrease and variations in rainfall, shortened growing season, crop failure, pests and diseases. However, most of the smallholder farmers disagreed with the frequency of flood incidences as they have not experienced these in their areas. In terms of responses to these changes in climate, the smallholder farmers have used a number of adaptation strategies to cope. Most of the farmers used crop diversification, organic manure, soil and water conservation practices, while others simply did not adapt and some used all the available adaptation strategies identified in this study. The results from the MNL revealed that occupation, household size and years spent in school (education) generally had a positive influence on the choice of adaptation strategy used by smallholder farmers. On the other hand, age; farming systems and membership of a farmers’ association were negatively affecting the smallholder farmers’ choice of adaptation strategy to use in response to climate change. Much support is needed in terms of disseminating information and knowledge among smallholder farmers about climate change and its adaptation strategies. This can be possible through improving extension services, and providing credit to smallholder farmers
- Full Text:
- Date Issued: 2019
Pharmacological Evaluation and Medicinal Potential of Vachellia Karroo (Hayne) Banfi & Galasso Pods traditionally used to treat Sexually Transmitted Diseases in the Eastern Cape, South Africa.
- Authors: Maposa, Sandisiwe
- Date: 2019
- Subjects: Medicinal plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14583 , vital:40017
- Description: Vachellia karroo is widely used in folk medicine in the Eastern Cape Province South Africa, however, the pods are usually discarded as waste. The current study was conducted to evaluate the phytochemical content and the antioxidant activity of V. karroo pods. The pods were extracted using acetone, distilled water, hexane and methanol. The total phenol, flavonoid, proanthocyanidin, alkaloid and saponin contents of the various extracts were determined spectrometrically and antioxidant activity was evaluated using inhibition of 2,2-diphenyl-1- picrylhydrazyl (DPPH), 2,2´-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), nitric oxide (NO) radicals, while total antioxidant capacity (TAC) was estimated by the phosphomolybdenum assay. V. karro pods had significant amounts of total phenols, flavonoids and proanthocynadin, although, proanthocynadin was not detected in the aqueous and hexane extracts. Methanol and acetone extracts showed higher phenolic, proanthocynadin and flavonoids contents (52.47 ± 6.82 and 29.31 ± 1.49), (334.8±85.1 and 231.22 ±1.80),(288±4.26 & 208.2±17.7) compared to the aqueous and hexane extracts. The alkaloid and saponin contents were 26.67 and 12.85 % respectively. The IC50 values of the methanol extract for DPPH, ABTS and total antioxidant capacity (TAC) were 0.345, 0.017 and 0.116 mg/mL, respectively. Methanol extract of V. karroo pod showed higher polyphenolic content of all the extracts analysed with corresponding strong free radical scavenging potential. These underutilized pods could serve as a new source of antioxidant compounds which could help in combating various ailments. The great antioxidant activity displayed by V. karroo pods extract supports the therapeutic use of this plant in traditional medicine and are attributed to the phytochemical content.The current information suggests that extracts from Vachellia karroo pods might be a ix cheap potential source of natural antioxidants that could be of great importance for the treatment of free radical related diseases. Furthermore, it makes a case for the utilization of the pods instead of discarding them as waste materials. The evaluation of antimicrobial potential of Vachellia karroo extracts was carried out using agar dilution assay against 8 bacterial strains-4 gram-positive [ Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (OK), Bacillus subtilis KZN, Bacillus cereus, and Streptococcus pyogenes] and 4 gram-negative strains[ Vibrio cholera, Klebsiella pneumonia (ATCC 4352), Pseudomonas aeruginosa (ATCC 19582), Salmonella typhi (OK) ]. Six fungal isolates[ Trichophyton mucoides ATCC 201382, Candida albicans (ATCC 10231), Candida glabatra, Penicillium chrysogenum, Aspergillus fumigatus, Penicillum aurantiogriseum] were usedor antifungal assessment. The methanol extract exhibited broad-spectrum activity, with Gram-positive strains being more sensitive than Gram-negative strains. The extracts also showed great inhibition against Candida albicans the fungal isolate responsible for causing candidiasis in women. Since the pods showed promising antimicrobial activity, they could serve as a cheap source for the treatment and management of these sexually transmitted infections. The brine shrimp toxicity test revealed successful hatching of the cysts was in the order: Aqueous extract> methanol extract> hexane extract> acetone extract. The hatching of nauplii was in a concentration dependent fashion, with hatching success decreasing with increase in concentration of extracts. Lethality of extracts determined based on Meyerʼs index of toxicity, showed that the acetone and hexane extracts of V. karroo were moderately toxic. The results of this study indicated that aqueous and methanolic extracts of Vachellia karroo pods were not toxic, therefore supporting its traditional therapeutic usage. This implies that rather than discard x the pods as is waste as it being currently done, Vachellia karroo pods could be salvaged and processed along with the leaves, thus reducing environmental pollution. Proximate parameters (moisture, ash, crude fibre, crude fat, proteins, and carbohydrate) were evaluated using ALASA methods, and elemental analysis by ICP-OES technique. Nutritional analysis showed that V. karroo pods had low content of crude fat and high content of crude fibre, ash, crude protein, and carbohydrate sufficient to meet the recommended dietary allowances. The pods were rich in major minerals Ca, K, P and Mg, with sufficient amount of trace elements Na, Fe, Zn, and Cu. The outcome of this study suggests that Vachellia karroo pods have good nutritional potentials to support or complement the recommended dietary allowance and could be a cheap source of essential nutrients that could help in ameliorating most nutritional challenges as well as contribute remarkably to the amount of nutrient intake in human and animal diets.
- Full Text:
- Date Issued: 2019
- Authors: Maposa, Sandisiwe
- Date: 2019
- Subjects: Medicinal plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14583 , vital:40017
- Description: Vachellia karroo is widely used in folk medicine in the Eastern Cape Province South Africa, however, the pods are usually discarded as waste. The current study was conducted to evaluate the phytochemical content and the antioxidant activity of V. karroo pods. The pods were extracted using acetone, distilled water, hexane and methanol. The total phenol, flavonoid, proanthocyanidin, alkaloid and saponin contents of the various extracts were determined spectrometrically and antioxidant activity was evaluated using inhibition of 2,2-diphenyl-1- picrylhydrazyl (DPPH), 2,2´-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), nitric oxide (NO) radicals, while total antioxidant capacity (TAC) was estimated by the phosphomolybdenum assay. V. karro pods had significant amounts of total phenols, flavonoids and proanthocynadin, although, proanthocynadin was not detected in the aqueous and hexane extracts. Methanol and acetone extracts showed higher phenolic, proanthocynadin and flavonoids contents (52.47 ± 6.82 and 29.31 ± 1.49), (334.8±85.1 and 231.22 ±1.80),(288±4.26 & 208.2±17.7) compared to the aqueous and hexane extracts. The alkaloid and saponin contents were 26.67 and 12.85 % respectively. The IC50 values of the methanol extract for DPPH, ABTS and total antioxidant capacity (TAC) were 0.345, 0.017 and 0.116 mg/mL, respectively. Methanol extract of V. karroo pod showed higher polyphenolic content of all the extracts analysed with corresponding strong free radical scavenging potential. These underutilized pods could serve as a new source of antioxidant compounds which could help in combating various ailments. The great antioxidant activity displayed by V. karroo pods extract supports the therapeutic use of this plant in traditional medicine and are attributed to the phytochemical content.The current information suggests that extracts from Vachellia karroo pods might be a ix cheap potential source of natural antioxidants that could be of great importance for the treatment of free radical related diseases. Furthermore, it makes a case for the utilization of the pods instead of discarding them as waste materials. The evaluation of antimicrobial potential of Vachellia karroo extracts was carried out using agar dilution assay against 8 bacterial strains-4 gram-positive [ Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (OK), Bacillus subtilis KZN, Bacillus cereus, and Streptococcus pyogenes] and 4 gram-negative strains[ Vibrio cholera, Klebsiella pneumonia (ATCC 4352), Pseudomonas aeruginosa (ATCC 19582), Salmonella typhi (OK) ]. Six fungal isolates[ Trichophyton mucoides ATCC 201382, Candida albicans (ATCC 10231), Candida glabatra, Penicillium chrysogenum, Aspergillus fumigatus, Penicillum aurantiogriseum] were usedor antifungal assessment. The methanol extract exhibited broad-spectrum activity, with Gram-positive strains being more sensitive than Gram-negative strains. The extracts also showed great inhibition against Candida albicans the fungal isolate responsible for causing candidiasis in women. Since the pods showed promising antimicrobial activity, they could serve as a cheap source for the treatment and management of these sexually transmitted infections. The brine shrimp toxicity test revealed successful hatching of the cysts was in the order: Aqueous extract> methanol extract> hexane extract> acetone extract. The hatching of nauplii was in a concentration dependent fashion, with hatching success decreasing with increase in concentration of extracts. Lethality of extracts determined based on Meyerʼs index of toxicity, showed that the acetone and hexane extracts of V. karroo were moderately toxic. The results of this study indicated that aqueous and methanolic extracts of Vachellia karroo pods were not toxic, therefore supporting its traditional therapeutic usage. This implies that rather than discard x the pods as is waste as it being currently done, Vachellia karroo pods could be salvaged and processed along with the leaves, thus reducing environmental pollution. Proximate parameters (moisture, ash, crude fibre, crude fat, proteins, and carbohydrate) were evaluated using ALASA methods, and elemental analysis by ICP-OES technique. Nutritional analysis showed that V. karroo pods had low content of crude fat and high content of crude fibre, ash, crude protein, and carbohydrate sufficient to meet the recommended dietary allowances. The pods were rich in major minerals Ca, K, P and Mg, with sufficient amount of trace elements Na, Fe, Zn, and Cu. The outcome of this study suggests that Vachellia karroo pods have good nutritional potentials to support or complement the recommended dietary allowance and could be a cheap source of essential nutrients that could help in ameliorating most nutritional challenges as well as contribute remarkably to the amount of nutrient intake in human and animal diets.
- Full Text:
- Date Issued: 2019
Phase Plane Analysis of Linear Systems in Dynamic Mathematical Models
- Authors: Marange, Simukai Daniel
- Date: 2019
- Subjects: Mathematical models
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14715 , vital:40064
- Description: A plethora of dynamic mathematical models exist and to understand and master all of them would be a gargantuan task. The author had, nonetheless, attempted to outline some of the methods used to analyse linear systems in modeling. Systems techniques are fundamental to current research in molecular cell-biology. The systems-approach stands in stark contrast to the historically, reductionist paradigm of molecular biology. Field work can be very dangerous. The main purpose of this study was to come up with the best analysis that would be used without going to the real field and thus saving time, money and risks associated with remote field localities. This research showed that the best analysis depends on the nature of the objectives intended to be solved by the model. Phase plane analysis on linear systems assisted in gaining deeper knowledge on the characteristics of such systems. This work analysed some dynamic models looking at phase planes, bifurcation, sensitivity and stability. The research provided a qualitative analysis of the processes not a numerical analysis.
- Full Text:
- Date Issued: 2019
- Authors: Marange, Simukai Daniel
- Date: 2019
- Subjects: Mathematical models
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14715 , vital:40064
- Description: A plethora of dynamic mathematical models exist and to understand and master all of them would be a gargantuan task. The author had, nonetheless, attempted to outline some of the methods used to analyse linear systems in modeling. Systems techniques are fundamental to current research in molecular cell-biology. The systems-approach stands in stark contrast to the historically, reductionist paradigm of molecular biology. Field work can be very dangerous. The main purpose of this study was to come up with the best analysis that would be used without going to the real field and thus saving time, money and risks associated with remote field localities. This research showed that the best analysis depends on the nature of the objectives intended to be solved by the model. Phase plane analysis on linear systems assisted in gaining deeper knowledge on the characteristics of such systems. This work analysed some dynamic models looking at phase planes, bifurcation, sensitivity and stability. The research provided a qualitative analysis of the processes not a numerical analysis.
- Full Text:
- Date Issued: 2019
Rural household dietary diversity and food security in Raymond Mhlaba local municipality
- Authors: Mnukwa, Minentle Lwando
- Date: 2019
- Subjects: Food security
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17282 , vital:40872
- Description: In order to formulate or implement relevant food security programmes in rural areas, it is important to have a deep understanding of the food security status of rural households. Accordingly, this study was conducted to assess the food security status of rural households in Raymond Mhlaba Local Municipality. The study also sought to identify the socio-economic characteristics that influence household food security status. The research relied on primary data. Primary data were collected by using a structured questionnaire, which covered both demographic features of respondent households, and their recent food consumption patterns. The household survey was conducted among 272 participants of Raymond Mhlaba Local Municipality. Statistical tools employed in this study included both descriptive and inferential statistics. The main descriptive statistics used were frequency tables, means and percentages in relation to a number of demographic characteristics and food security indicators. The main indicator of food security/insecurity used in the study was the Household Dietary Diversity Score (HDDS). After calculating the HDDS for each household, households were defined as either food secure or insecure depending on whether their HDDS was above or below the average HDDS. A logistic regression model (binary or dichotomous) was then used to identify socio-economic factors that influence some households to have above-average rather than below-average food security levels. The Binary logistic regression model revealed that four out of eight variables included in the model were significant in explaining the variation in the food security situation of households in the study areas, namely age of household head, education level of household head, household income and household size. Of these, the first three were positively associated with aboveaverage food security status, while household size had a negative association. A Tobit model was further used to identify the determinants of the household dietary diversity score. The exact same variables were significant from the Tobit analysis, and in the same manner.
- Full Text:
- Date Issued: 2019
- Authors: Mnukwa, Minentle Lwando
- Date: 2019
- Subjects: Food security
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17282 , vital:40872
- Description: In order to formulate or implement relevant food security programmes in rural areas, it is important to have a deep understanding of the food security status of rural households. Accordingly, this study was conducted to assess the food security status of rural households in Raymond Mhlaba Local Municipality. The study also sought to identify the socio-economic characteristics that influence household food security status. The research relied on primary data. Primary data were collected by using a structured questionnaire, which covered both demographic features of respondent households, and their recent food consumption patterns. The household survey was conducted among 272 participants of Raymond Mhlaba Local Municipality. Statistical tools employed in this study included both descriptive and inferential statistics. The main descriptive statistics used were frequency tables, means and percentages in relation to a number of demographic characteristics and food security indicators. The main indicator of food security/insecurity used in the study was the Household Dietary Diversity Score (HDDS). After calculating the HDDS for each household, households were defined as either food secure or insecure depending on whether their HDDS was above or below the average HDDS. A logistic regression model (binary or dichotomous) was then used to identify socio-economic factors that influence some households to have above-average rather than below-average food security levels. The Binary logistic regression model revealed that four out of eight variables included in the model were significant in explaining the variation in the food security situation of households in the study areas, namely age of household head, education level of household head, household income and household size. Of these, the first three were positively associated with aboveaverage food security status, while household size had a negative association. A Tobit model was further used to identify the determinants of the household dietary diversity score. The exact same variables were significant from the Tobit analysis, and in the same manner.
- Full Text:
- Date Issued: 2019
Sedimentology and shale gas potential of the Ecca Group, Karoo Supergroup in the Eastern Cape, South Africa
- Authors: Nemanashi , Tshisikhaiwe
- Date: 2019
- Subjects: Sedimentology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14616 , vital:40023
- Description: The aim of the study was to establish a deeper understanding on the stratigraphy, sedimentology, petrology, organic geochemistry and diagenesis of the Ecca Group, and to provide new insight on the shale gas occurrence and potential of the Ecca Group, Karoo Supergroup in the southern Karoo Basin. The Ecca Group stratigraphy is divided into five formations from the bottom upwards, namely the Prince Albert, Whitehill, Collingham, Ripon and the Fort Brown Formations. The stratigraphy of the five studied stratigraphy’s formations is now sub-divided into two new different members each. These subdivision was based on field investigation of lithological features, sedimentary structures, facies characteristics and stratigraphic correlation points. Each member has been assigned a lithological name. Sixteen sedimentary facies have been identified in the study area and were subdivided into six distinctive facies associations (FA 1, FA 2, FA 3, FA 4, FA 5 and FA 6). Sedimentological characteristics of facies associations identified indicate that the Ecca Group sediments initially accumulated in a deep marine environment, progressed through turbidite, shallow marine and ended in lacustrine and deltaic environments. The stratigraphic succession of the Ecca Group constitutes a perfect regression sequence, indicating that the marine water gradually retreated and the sea-level gradually dropped. Grain size analysis was performed on twenty four Ecca Group sandstone samples. Statistical parameters of grain-size statistical parameters, linear discriminate functions, passega diagrams and bivariate analysis were used to reveal the hydrodynamic conditions and depositional environments. The results indicated that the Ecca Group sandstones are mostly fine to very fine grained, near-symmetrical, mesokurtic and indicative of dominance of low energy environments. The linear discriminate function analysis for the Prince Albert, Whitehill, Collingham and Ripon Formations samples indicates that the majority of the deposits were by turbidity currents all in a deep marine environment; whilst of the Fort Brown Formation samples are lacustrine/deltaic deposits. The depositional mechanism C-M plot indicates that majority of the Ecca Group sediments clustered in the PQ and QR field suggesting deposition mainly by suspension, rolling or saltation as well as graded suspension. Modal mineral composition analysis indicates that the main framework grains of the Ecca Group sandstones are quartz, feldspar as well as lithic fragments derived from metamorphic, igneous and sedimentary rocks with a few from volcanic origin. The Ecca Group sandstones iii are immature compositionally and can be classified as feldspathic wackes and lithic wackes. The QFL ternary diagram revealed a dissected and recycled orogen arc provenance; whereas QmFLt ternary diagram point to dissected arc and transitional arc sources to an active continental margin as well as recycled provenance. These provenance characteristics suggest a metamorphic and plutonic terrains influence as the main source rock with minor debris derived from recycled sedimentary rocks. The weathering diagram and semi-quantitative weathering index suggests that the sandstones from the Ecca are mostly from a plutonic source area under arid to humid climatic conditions. The detrital modal compositions of these Ecca Group sandstones are related to a strike-slip setting, back arc to continental margin setting. Diagenetic features of the Ecca sandstones and shales are subdivided into early, late (burial) and uplift-related diagenetic stages. Mechanical compaction, recrystallization, cementation, replacement and the dissolution of framework grains or cements are some of the main diagenetic processes that largely affected the Ecca sediments. Early diagenetic processes include cementation, point/planar contact, formation of pyrite, hematite cements and mineral inversions. Recrystallization, replacement, compaction, overgrowth, albitization, seritisation, illitization, concave-convex and suture contacts as well as dissolution took place mostly in the later diagenetic stage due to increase of temperature and pressure as burial depth increased. The uplift-related diagenetic stage was mostly affected by deformation and fracturing, calcitization, dissolution, erosion and weathering. Diagenetic processes largely affected the porosity and permeability of the reservoir rock properties of the Ecca Group. Organic geochemistry results indicate that the sediments were highly weathered and the TOC values ranging from 0.10 to 7.35 wt% with mostly less than 0.5%, which indicate the source rocks have poor oil potential. The majority of the Ecca Shales have HI values less than 50 mg HC/g, TOC indicating Type-IV kerogen mostly derived from reworked organic matter with very little hydrocarbon generation potential. The relatively high Tmax (oC) and vitrinite reflective values indicate that most shales are thermally over-matured thus they have low hydrocarbon pontential.
- Full Text:
- Date Issued: 2019
- Authors: Nemanashi , Tshisikhaiwe
- Date: 2019
- Subjects: Sedimentology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14616 , vital:40023
- Description: The aim of the study was to establish a deeper understanding on the stratigraphy, sedimentology, petrology, organic geochemistry and diagenesis of the Ecca Group, and to provide new insight on the shale gas occurrence and potential of the Ecca Group, Karoo Supergroup in the southern Karoo Basin. The Ecca Group stratigraphy is divided into five formations from the bottom upwards, namely the Prince Albert, Whitehill, Collingham, Ripon and the Fort Brown Formations. The stratigraphy of the five studied stratigraphy’s formations is now sub-divided into two new different members each. These subdivision was based on field investigation of lithological features, sedimentary structures, facies characteristics and stratigraphic correlation points. Each member has been assigned a lithological name. Sixteen sedimentary facies have been identified in the study area and were subdivided into six distinctive facies associations (FA 1, FA 2, FA 3, FA 4, FA 5 and FA 6). Sedimentological characteristics of facies associations identified indicate that the Ecca Group sediments initially accumulated in a deep marine environment, progressed through turbidite, shallow marine and ended in lacustrine and deltaic environments. The stratigraphic succession of the Ecca Group constitutes a perfect regression sequence, indicating that the marine water gradually retreated and the sea-level gradually dropped. Grain size analysis was performed on twenty four Ecca Group sandstone samples. Statistical parameters of grain-size statistical parameters, linear discriminate functions, passega diagrams and bivariate analysis were used to reveal the hydrodynamic conditions and depositional environments. The results indicated that the Ecca Group sandstones are mostly fine to very fine grained, near-symmetrical, mesokurtic and indicative of dominance of low energy environments. The linear discriminate function analysis for the Prince Albert, Whitehill, Collingham and Ripon Formations samples indicates that the majority of the deposits were by turbidity currents all in a deep marine environment; whilst of the Fort Brown Formation samples are lacustrine/deltaic deposits. The depositional mechanism C-M plot indicates that majority of the Ecca Group sediments clustered in the PQ and QR field suggesting deposition mainly by suspension, rolling or saltation as well as graded suspension. Modal mineral composition analysis indicates that the main framework grains of the Ecca Group sandstones are quartz, feldspar as well as lithic fragments derived from metamorphic, igneous and sedimentary rocks with a few from volcanic origin. The Ecca Group sandstones iii are immature compositionally and can be classified as feldspathic wackes and lithic wackes. The QFL ternary diagram revealed a dissected and recycled orogen arc provenance; whereas QmFLt ternary diagram point to dissected arc and transitional arc sources to an active continental margin as well as recycled provenance. These provenance characteristics suggest a metamorphic and plutonic terrains influence as the main source rock with minor debris derived from recycled sedimentary rocks. The weathering diagram and semi-quantitative weathering index suggests that the sandstones from the Ecca are mostly from a plutonic source area under arid to humid climatic conditions. The detrital modal compositions of these Ecca Group sandstones are related to a strike-slip setting, back arc to continental margin setting. Diagenetic features of the Ecca sandstones and shales are subdivided into early, late (burial) and uplift-related diagenetic stages. Mechanical compaction, recrystallization, cementation, replacement and the dissolution of framework grains or cements are some of the main diagenetic processes that largely affected the Ecca sediments. Early diagenetic processes include cementation, point/planar contact, formation of pyrite, hematite cements and mineral inversions. Recrystallization, replacement, compaction, overgrowth, albitization, seritisation, illitization, concave-convex and suture contacts as well as dissolution took place mostly in the later diagenetic stage due to increase of temperature and pressure as burial depth increased. The uplift-related diagenetic stage was mostly affected by deformation and fracturing, calcitization, dissolution, erosion and weathering. Diagenetic processes largely affected the porosity and permeability of the reservoir rock properties of the Ecca Group. Organic geochemistry results indicate that the sediments were highly weathered and the TOC values ranging from 0.10 to 7.35 wt% with mostly less than 0.5%, which indicate the source rocks have poor oil potential. The majority of the Ecca Shales have HI values less than 50 mg HC/g, TOC indicating Type-IV kerogen mostly derived from reworked organic matter with very little hydrocarbon generation potential. The relatively high Tmax (oC) and vitrinite reflective values indicate that most shales are thermally over-matured thus they have low hydrocarbon pontential.
- Full Text:
- Date Issued: 2019