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:
- 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:
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:
- 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:
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:
- 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
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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:
- 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:
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:
- 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.
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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:
- 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.
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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:
- 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.
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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:
- 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:
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:
- 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:
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:
- 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:
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:
- 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:
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:
- 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:
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:
- 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:
Sequencing, assembly and annotation of the mitochondrial and plastid genomes of Gelidium pristoides (Turner) Kützing from Kenton-on-Sea, South Africa
- Authors: Mangali, Sandisiwe
- Date: 2019
- Subjects: Gelidium -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/19109 , vital:39883
- Description: The genome is the complete set of an organism's hereditary information that contains all the information necessary for the functioning of that organism. Complete nuclear, mitochondrial and plastid DNA constitute the three main types of genomes which play interconnected roles in an organism. Genome sequencing enables researchers to understand the regulation and expression of the various genes and the proteins they encode. It allows researchers to extract and analyse genes of interests for a variety of studies including molecular, biotechnological, bioinformatics and conservation and evolutionary studies. Genome sequencing of Rhodophyta has received little attention. To date, no published studies are focusing on both whole genome sequencing and sequencing of the organellar genomes of Rhodophyta species found in along the South African coastline. This study focused on genome sequencing, assembly and annotation mitochondrial and plastid genomes of Gelidium pristoides. Gelidium pristoides was collected from Kenton-on-Sea and was morphologically identified at Rhodes University. Its genomic DNA was extracted using the Nucleospin® Plant II kit and quantified using Qubit 2.0, Nanodrop and 1% agarose gel electrophoresis. The Ion Plus Fragment Library kit was used for the preparation of a 600 bp library, which was sequenced in two separate runs through the Ion S5 platform. The produced reads were quality-controlled through the Ion Torrent server version 5.6. and assessed using the FASTQC program. The SPAdes version 3.11.1 assembler was used to assemble the quality-controlled reads, and the resultant genome assembly was quality-assessed using the QUAST 4.1 software. The mitochondrial genome was selected from the produced Gelidium pristoides draft genome using mitochondrial genomes of other Gelidiales as search queries on the local BLAST algorithm of the BioEdit software. Contigs matching the organellar genomes were ordered according to the mitochondrial genomes of other Gelidiales using the trial version of Geneious R11.12 software. The plastid genome was also selected following the same approach but using plastid genomes of Gelidium elegans and Gelidium vagum as search queries. Gaps observed in the organellar genomes were closed by amplification of the relevant gap using polymerase chain reaction with newly designed primers and Sanger sequencing. Open reading frames for both organellar genomes were annotated using the NCBI ORF-Finder and alignments obtained from BlastN and BlastX searches from the NCBI database, while the tRNAs and rRNAs were identified using the tRNAscan-SE1.21 vi and the RNAmmer 1.2 servers. The circular physical map of the mitochondrial genome was constructed using the CGView server. Lastly, in silico analysis of cytochrome c oxidase 3 and Heat Shock Protein 70 was performed using the PRIMO and the SWISS-MODEL pipelines respectively. Their phylogenies were analysed through Clustal omega and the trees viewed on TreeView 1.6.6 software. Qubit and Nanodrop genomic DNA qualification revealed A260/A280 and A230/A260 ratios of 1.81 and 1.52 respectively. The 1% agarose gel electrophoresis further confirmed the good quality of the genomic DNA used for library preparation and sequencing. Pre-assembly quality control of reads resulted in a total of 30 792 074 high-quality reads which were assembled into a total of 94140 contigs, making up an estimated genome length of 217.06 Mb. The largest contig covered up to 13.17 kb of the draft genome, and an N50 statistic value of 3.17 kb was obtained. The G.pristoides mitochondrial genome mapped into a circular molecule of 25012 bp, with an overall GC content of 31.04% and a total of 45 genes distributed into 20 tRNA-coding, 2 rRNAcoding genes and 23 protein-coding genes, mostly adopting the modified genetic code of Rhodophyta. The SecY and rps12 genes overlapped by 41 bp. This study presents a partial plastid genome composed of 89 (38%) fully annotated genes, of which 71 are protein-coding, and 18 are distributed among 15 tRNA-coding, 2 rRNA-coding and 1 RNaseP RNA-coding genes. Sixty-one (26%) partial protein-coding genes were predicted, while approximately 84 (36%) genes are not yet predicted. In silico analysis of the cytochrome c oxidase and heat shock protein 70 showed that the gene sequences obtained in this study and the resultant transcribed protein have sequences and structures that are similar to those from several other different species, thus validating the integrity of the genome sequences. This study provides genomic data necessary for understanding the genomic constituent of G.pristoides and serve as a foundation for studies of individual genes and for resolving evolutionary relationships.
- Full Text:
- Authors: Mangali, Sandisiwe
- Date: 2019
- Subjects: Gelidium -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/19109 , vital:39883
- Description: The genome is the complete set of an organism's hereditary information that contains all the information necessary for the functioning of that organism. Complete nuclear, mitochondrial and plastid DNA constitute the three main types of genomes which play interconnected roles in an organism. Genome sequencing enables researchers to understand the regulation and expression of the various genes and the proteins they encode. It allows researchers to extract and analyse genes of interests for a variety of studies including molecular, biotechnological, bioinformatics and conservation and evolutionary studies. Genome sequencing of Rhodophyta has received little attention. To date, no published studies are focusing on both whole genome sequencing and sequencing of the organellar genomes of Rhodophyta species found in along the South African coastline. This study focused on genome sequencing, assembly and annotation mitochondrial and plastid genomes of Gelidium pristoides. Gelidium pristoides was collected from Kenton-on-Sea and was morphologically identified at Rhodes University. Its genomic DNA was extracted using the Nucleospin® Plant II kit and quantified using Qubit 2.0, Nanodrop and 1% agarose gel electrophoresis. The Ion Plus Fragment Library kit was used for the preparation of a 600 bp library, which was sequenced in two separate runs through the Ion S5 platform. The produced reads were quality-controlled through the Ion Torrent server version 5.6. and assessed using the FASTQC program. The SPAdes version 3.11.1 assembler was used to assemble the quality-controlled reads, and the resultant genome assembly was quality-assessed using the QUAST 4.1 software. The mitochondrial genome was selected from the produced Gelidium pristoides draft genome using mitochondrial genomes of other Gelidiales as search queries on the local BLAST algorithm of the BioEdit software. Contigs matching the organellar genomes were ordered according to the mitochondrial genomes of other Gelidiales using the trial version of Geneious R11.12 software. The plastid genome was also selected following the same approach but using plastid genomes of Gelidium elegans and Gelidium vagum as search queries. Gaps observed in the organellar genomes were closed by amplification of the relevant gap using polymerase chain reaction with newly designed primers and Sanger sequencing. Open reading frames for both organellar genomes were annotated using the NCBI ORF-Finder and alignments obtained from BlastN and BlastX searches from the NCBI database, while the tRNAs and rRNAs were identified using the tRNAscan-SE1.21 vi and the RNAmmer 1.2 servers. The circular physical map of the mitochondrial genome was constructed using the CGView server. Lastly, in silico analysis of cytochrome c oxidase 3 and Heat Shock Protein 70 was performed using the PRIMO and the SWISS-MODEL pipelines respectively. Their phylogenies were analysed through Clustal omega and the trees viewed on TreeView 1.6.6 software. Qubit and Nanodrop genomic DNA qualification revealed A260/A280 and A230/A260 ratios of 1.81 and 1.52 respectively. The 1% agarose gel electrophoresis further confirmed the good quality of the genomic DNA used for library preparation and sequencing. Pre-assembly quality control of reads resulted in a total of 30 792 074 high-quality reads which were assembled into a total of 94140 contigs, making up an estimated genome length of 217.06 Mb. The largest contig covered up to 13.17 kb of the draft genome, and an N50 statistic value of 3.17 kb was obtained. The G.pristoides mitochondrial genome mapped into a circular molecule of 25012 bp, with an overall GC content of 31.04% and a total of 45 genes distributed into 20 tRNA-coding, 2 rRNAcoding genes and 23 protein-coding genes, mostly adopting the modified genetic code of Rhodophyta. The SecY and rps12 genes overlapped by 41 bp. This study presents a partial plastid genome composed of 89 (38%) fully annotated genes, of which 71 are protein-coding, and 18 are distributed among 15 tRNA-coding, 2 rRNA-coding and 1 RNaseP RNA-coding genes. Sixty-one (26%) partial protein-coding genes were predicted, while approximately 84 (36%) genes are not yet predicted. In silico analysis of the cytochrome c oxidase and heat shock protein 70 showed that the gene sequences obtained in this study and the resultant transcribed protein have sequences and structures that are similar to those from several other different species, thus validating the integrity of the genome sequences. This study provides genomic data necessary for understanding the genomic constituent of G.pristoides and serve as a foundation for studies of individual genes and for resolving evolutionary relationships.
- Full Text:
Spectroscopy based mapping of selected dominant rock types in the Balfour Formation (Beaufort Group), Eastern Cape Province, South Africa
- Authors: Qabaqaba, Mcebisi
- Date: 2019
- Subjects: spectrum Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14693 , vital:40057
- Description: Lithological mapping of areas is crucial for both mineral resource identification and determination of ore concentrations. Without adequate knowledge on the extent of an area’s lithology, the above applications cannot be meaningfully accomplished. Spectroscopy-based mapping of rocks involves the use of portable reflectance spectrometers and digital maps to analyze, assess and map changes in rocks. Thereafter, understand and interpret the geochemical, physical and environmental processes that have an impact on the reflectance of the rocks while also making spatial and spectral links. Mapping lithology using remote sensing involves identification of rocks in remotely sensed images with lithological mapping being achievable through field and laboratory spectroscopy and creation of a spectral library. The main goal of this study was to measure, extract and analyze spectral signatures of dominant rocks within the Balfour Formation in order to create a spectral library that is capable of enabling, fast and cost-effective mapping of the spatial distributions of rocks within the Balfour Formation. The spectra of dominant rocks of the Balfour Formation were measured using the SR 3500 spectroradiometer. Different pre-processing techniques were applied to the acquired spectra such as smoothing, scatter correction and outlier detection. Random Forest classifier was used in the classification of the different rocks. Analysis of Variance and Bonferroni post hoc test were applied on the spectral signatures of different rocks to ascertain if there were any spectral differences between the absorption features in the spectra of the rocks. Landsat 8 imagery was used for classification of the different rocks within the Balfour Formation, maximum likelihood and spectral angle mapper were the two classifiers that were XI used. Maximum likelihood presented an accuracy of 76.19 % and 66.67 % for spectral angle mapper.
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- Authors: Qabaqaba, Mcebisi
- Date: 2019
- Subjects: spectrum Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14693 , vital:40057
- Description: Lithological mapping of areas is crucial for both mineral resource identification and determination of ore concentrations. Without adequate knowledge on the extent of an area’s lithology, the above applications cannot be meaningfully accomplished. Spectroscopy-based mapping of rocks involves the use of portable reflectance spectrometers and digital maps to analyze, assess and map changes in rocks. Thereafter, understand and interpret the geochemical, physical and environmental processes that have an impact on the reflectance of the rocks while also making spatial and spectral links. Mapping lithology using remote sensing involves identification of rocks in remotely sensed images with lithological mapping being achievable through field and laboratory spectroscopy and creation of a spectral library. The main goal of this study was to measure, extract and analyze spectral signatures of dominant rocks within the Balfour Formation in order to create a spectral library that is capable of enabling, fast and cost-effective mapping of the spatial distributions of rocks within the Balfour Formation. The spectra of dominant rocks of the Balfour Formation were measured using the SR 3500 spectroradiometer. Different pre-processing techniques were applied to the acquired spectra such as smoothing, scatter correction and outlier detection. Random Forest classifier was used in the classification of the different rocks. Analysis of Variance and Bonferroni post hoc test were applied on the spectral signatures of different rocks to ascertain if there were any spectral differences between the absorption features in the spectra of the rocks. Landsat 8 imagery was used for classification of the different rocks within the Balfour Formation, maximum likelihood and spectral angle mapper were the two classifiers that were XI used. Maximum likelihood presented an accuracy of 76.19 % and 66.67 % for spectral angle mapper.
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Synthesis, characterization and anticancer studies of Oxovanadium(iv) Dithiocarbamate complexes
- Authors: Hlobo, Priscilla Vuyiswa
- Date: 2019
- Subjects: Inorganic compounds -- Synthesis Chemistry, Inorganic
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/19131 , vital:39880
- Description: Eight new oxovanadium(IV) dithiocarbamate complexes, formed by the interaction of vanadyl sulfate pentahydrate and as-synthesized dithiocarbamate ligands, potassium N-morpholine-4- dithiocarbamate ligand (L1), potassium N-piperidinedithiocarbamate (L2), potassium N-(4- methoxyphenyl)dithiocarbamate ligand (L3), potassium N-diallyldithiocarbamate ligand (L4), potassium N-phenyldithiocarbamate ligand (L5), potassium N-dibenzylminedithiocarbamate ligand (L6), potassium N-(4-methylphenyl)dithiocarbamate ligand (L7), N-(1Himidazoledithiocarbamate) fluoride ligand (L8) in aqueous ethanol are described. The resulting complexes were elemental analyses, molar conductance, infrared, electronic, and nuclear magnetic resonance spectral studies. The spectral studies confirmed the formation of the ligands and complexes. Four complexes [VO(L1)2], [VO(L3)2], [VO(L6)2], and [VO(L8)2] derived from potassium N-morpholine-4-dithiocarbamate ligand (L1), potassium N-(4- methoxyphenyl)dithiocarbamate ligand (L3), potassium N-dibenzylminedithiocarbamate ligand (L6), and N-(1H-imidazoledithiocarbamate) fluoride ligand (L8) were characterized using cyclic voltammetry, to study their electrochemical behavior. Square pyramid oxovanadium(IV) complexes were proposed with the metal ion coordinated to two bidentate dithiocarbamate ligands through sulphur to complete its square pyramidal geometry. The anticancer screening of four oxovanadium(IV) dithiocarbamate complexes [VO(L1)2], [VO(L3)2], [VO(L6)2], and [VO(L8)2] are described.
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- Authors: Hlobo, Priscilla Vuyiswa
- Date: 2019
- Subjects: Inorganic compounds -- Synthesis Chemistry, Inorganic
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/19131 , vital:39880
- Description: Eight new oxovanadium(IV) dithiocarbamate complexes, formed by the interaction of vanadyl sulfate pentahydrate and as-synthesized dithiocarbamate ligands, potassium N-morpholine-4- dithiocarbamate ligand (L1), potassium N-piperidinedithiocarbamate (L2), potassium N-(4- methoxyphenyl)dithiocarbamate ligand (L3), potassium N-diallyldithiocarbamate ligand (L4), potassium N-phenyldithiocarbamate ligand (L5), potassium N-dibenzylminedithiocarbamate ligand (L6), potassium N-(4-methylphenyl)dithiocarbamate ligand (L7), N-(1Himidazoledithiocarbamate) fluoride ligand (L8) in aqueous ethanol are described. The resulting complexes were elemental analyses, molar conductance, infrared, electronic, and nuclear magnetic resonance spectral studies. The spectral studies confirmed the formation of the ligands and complexes. Four complexes [VO(L1)2], [VO(L3)2], [VO(L6)2], and [VO(L8)2] derived from potassium N-morpholine-4-dithiocarbamate ligand (L1), potassium N-(4- methoxyphenyl)dithiocarbamate ligand (L3), potassium N-dibenzylminedithiocarbamate ligand (L6), and N-(1H-imidazoledithiocarbamate) fluoride ligand (L8) were characterized using cyclic voltammetry, to study their electrochemical behavior. Square pyramid oxovanadium(IV) complexes were proposed with the metal ion coordinated to two bidentate dithiocarbamate ligands through sulphur to complete its square pyramidal geometry. The anticancer screening of four oxovanadium(IV) dithiocarbamate complexes [VO(L1)2], [VO(L3)2], [VO(L6)2], and [VO(L8)2] are described.
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Synthesis, characterization and in vitro antibacterial analysis of carvacrol based-hybrid analogues
- Authors: Mbese, Zintle
- Date: 2019
- Subjects: Medicinal plants Herbs -- Therapeutic use
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14527 , vital:39998
- Description: he focus of this research was to synthesize and characterize carvacrol hybrid analogues. Twenty-one (21) carvacrol analogues were synthesized by reacting carvacrol with (1. 4- aminosalicylic acid, 2. ferrocene keto-butanoic acid, 3. Ferrocene butanoic acid, 4. succinic anhydride, 5. folic acid, 6. cinnamic acid, 7. leucovorin, 8. oleanolic acid, 9. artesunate, 10. cholesterol, 11. cholesterol succinate, 12. curcumin, 13. curcumin succinate, 14. zidovudine, 15. Zidovudine succinate, 16. 8-hydroxyquinoline, 17. 8-hydroxyquinoline succinate, 18. 2- (7-chloroquinolin-4-ylamino)ethyl 5-isopropyl-2-methylphenyl, 19. 2-(7-chloroquinolin-4- ylamino)ethyl 5-isopropyl-2-methylphenyl succinate, 20. 2-(2-(7-chloroquinolin-4- ylamino)ethoxy)ethyl 5-isopropyl-2-methylphenyl, 21. 2-(2-(7-chloroquinolin-4- ylamino)ethoxy)ethyl 5-isopropyl-2-methylphenyl succinate). The carvacrol analogues were characterized using FTIR, UHPLC-HRMS, 1H- and 13C-NMR spectroscopy. The antibacterial analysis was performed to evaluate the carvacrol analogues against bacterial strains. FTIR spectra of carvacrol analogues were found to exhibit peaks of C-O stretch and Ar-C in a range of 1014-1280 cm-1 and a range of 1414-1697 cm-1 which confirm the successful formation of esters. The proposed structures of carvacrol analogues were confirmed by the 1H- and 13C-NMR. The selected 1H-NMR signal for aromatic protons ranged at 6.00-8.95 ppm/δ. The selected 13C-NMR signal for ester carbon and aromatic carbons ranged at 160.0-175.0 ppm/δ and at 110.00-154.00 ppm/δ. The structures were also confirmed by UHPLC-HRMS. Carvacrol analogues exhibited the highest inhibitory effect against Gram-positive and Gram-negative tested bacterial strains.
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- Authors: Mbese, Zintle
- Date: 2019
- Subjects: Medicinal plants Herbs -- Therapeutic use
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14527 , vital:39998
- Description: he focus of this research was to synthesize and characterize carvacrol hybrid analogues. Twenty-one (21) carvacrol analogues were synthesized by reacting carvacrol with (1. 4- aminosalicylic acid, 2. ferrocene keto-butanoic acid, 3. Ferrocene butanoic acid, 4. succinic anhydride, 5. folic acid, 6. cinnamic acid, 7. leucovorin, 8. oleanolic acid, 9. artesunate, 10. cholesterol, 11. cholesterol succinate, 12. curcumin, 13. curcumin succinate, 14. zidovudine, 15. Zidovudine succinate, 16. 8-hydroxyquinoline, 17. 8-hydroxyquinoline succinate, 18. 2- (7-chloroquinolin-4-ylamino)ethyl 5-isopropyl-2-methylphenyl, 19. 2-(7-chloroquinolin-4- ylamino)ethyl 5-isopropyl-2-methylphenyl succinate, 20. 2-(2-(7-chloroquinolin-4- ylamino)ethoxy)ethyl 5-isopropyl-2-methylphenyl, 21. 2-(2-(7-chloroquinolin-4- ylamino)ethoxy)ethyl 5-isopropyl-2-methylphenyl succinate). The carvacrol analogues were characterized using FTIR, UHPLC-HRMS, 1H- and 13C-NMR spectroscopy. The antibacterial analysis was performed to evaluate the carvacrol analogues against bacterial strains. FTIR spectra of carvacrol analogues were found to exhibit peaks of C-O stretch and Ar-C in a range of 1014-1280 cm-1 and a range of 1414-1697 cm-1 which confirm the successful formation of esters. The proposed structures of carvacrol analogues were confirmed by the 1H- and 13C-NMR. The selected 1H-NMR signal for aromatic protons ranged at 6.00-8.95 ppm/δ. The selected 13C-NMR signal for ester carbon and aromatic carbons ranged at 160.0-175.0 ppm/δ and at 110.00-154.00 ppm/δ. The structures were also confirmed by UHPLC-HRMS. Carvacrol analogues exhibited the highest inhibitory effect against Gram-positive and Gram-negative tested bacterial strains.
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The effect of fresh seaweed and a formulated diet supplemented with seaweed on the growth and gonad quality of the collector sea urchin, Tripneustes gratilla under farm conditions
- Authors: Onomu , Abigail John
- Date: 2019
- Subjects: Marine algae Algae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14682 , vital:40044
- Description: This study investigates the effect of two fresh seaweeds, a formulated diet and different feeding regimes on the growth (weight, diameter and height) and gonad quality (gonadosomatic index, colour, texture, firmness and gonad maturity) of the collector sea urchin, Tripneustes gratilla under farm conditions for eighteen weeks. The gonad enhancement study was divided into two sections. The first section investigated the effect of feeds on the somatic growth and gonad quality for 12 weeks. The feeds investigated during this phase of the study were fresh Ulva (U); a 50:50 mixture of fresh Ulva and Gracilaria (UG); fresh Gracilaria (G) and a formulated diet, which contained 200g of dried Ulva per kg (designated as 20U). The second section or phase of this study started for a period of 6 weeks and investigated the effect of a change of diet on urchins previously fed the various feeds from section 1. The feeding regimes used were (U-20U) i.e urchins previously fed with Ulva were subsequently fed 20U diet, similarly, (UG-20U); (G-20U) and (20U- 20U). For the first section of the experiment, no differences were observed in the growth (weight, diameter and height) of urchins fed both fresh diets and the formulated diet. However, urchins fed the formulated diet produced gonad weight of 50.72 ± 5.4g which was significantly higher (P<0.001) than those fed fresh diets. The gonads of urchins fed the Gracilaria diet were significantly darker (P= 0.023) in colour compared with those examined from urchins fed the formulated diet, but were not significantly different from any of the other fresh diets tested (Ulva and Ulva mixed with Gracilaria). Gonad from each of the feed treatments were similar in terms of the redness (a*) and yellowness (b*) as well as the texture and firmness. The gonad maturities of urchins fed the various diets were not significantly different from each other. By the end of the second section/phase of the study (6 week period following the diet change), somatic growth (weight, height and diameter) of urchins in all treatment groups did not differ significantly from each other (ANOVA, P= 0.784; P= 0.988; P= 0.28 respectively). Gonad weight of urchins in treatment groups UG-20U and G-20U became similar to those fed the 20U diet at the end of the trial (week18). However, the gonad weight of urchins in the 20U treatment group remained significantly greater than urchins in the U-20U group at the end of the trial (Kruskal-Wallis ANOVA, P= 0.002). Gonad colour of urchins in the G-20U treatment became significantly lighter (ANOVA, P= 0.029) than those in the U-20U group after the change of diet. However, gonad lightness (L*) of urchins in treatment groups U-20U and G–20U did not differ significantly from those in the UG-20U and 20U treatment groups. All feed regimes were similar in terms of the gonad‟s redness (a*) and yellowness (b*), texture and firmness as well as gonad maturity at the end of the trial. This gonad enhancement study on wild collected adult T. gratilla has shown that somatic growth (urchin weight, test diameter and height) does not differ between the dietary treatments (fresh seaweeds and a formulated diet) tested in this study. The formulated feed (20U diet) does however enhance gonad growth of T. gratilla under farm conditions, supporting previous laboratory trials conducted on this species fed similar diets, indicating that sea urchins gonad enhancement can be cultured under farm conditions in South Africa.
- Full Text:
- Authors: Onomu , Abigail John
- Date: 2019
- Subjects: Marine algae Algae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14682 , vital:40044
- Description: This study investigates the effect of two fresh seaweeds, a formulated diet and different feeding regimes on the growth (weight, diameter and height) and gonad quality (gonadosomatic index, colour, texture, firmness and gonad maturity) of the collector sea urchin, Tripneustes gratilla under farm conditions for eighteen weeks. The gonad enhancement study was divided into two sections. The first section investigated the effect of feeds on the somatic growth and gonad quality for 12 weeks. The feeds investigated during this phase of the study were fresh Ulva (U); a 50:50 mixture of fresh Ulva and Gracilaria (UG); fresh Gracilaria (G) and a formulated diet, which contained 200g of dried Ulva per kg (designated as 20U). The second section or phase of this study started for a period of 6 weeks and investigated the effect of a change of diet on urchins previously fed the various feeds from section 1. The feeding regimes used were (U-20U) i.e urchins previously fed with Ulva were subsequently fed 20U diet, similarly, (UG-20U); (G-20U) and (20U- 20U). For the first section of the experiment, no differences were observed in the growth (weight, diameter and height) of urchins fed both fresh diets and the formulated diet. However, urchins fed the formulated diet produced gonad weight of 50.72 ± 5.4g which was significantly higher (P<0.001) than those fed fresh diets. The gonads of urchins fed the Gracilaria diet were significantly darker (P= 0.023) in colour compared with those examined from urchins fed the formulated diet, but were not significantly different from any of the other fresh diets tested (Ulva and Ulva mixed with Gracilaria). Gonad from each of the feed treatments were similar in terms of the redness (a*) and yellowness (b*) as well as the texture and firmness. The gonad maturities of urchins fed the various diets were not significantly different from each other. By the end of the second section/phase of the study (6 week period following the diet change), somatic growth (weight, height and diameter) of urchins in all treatment groups did not differ significantly from each other (ANOVA, P= 0.784; P= 0.988; P= 0.28 respectively). Gonad weight of urchins in treatment groups UG-20U and G-20U became similar to those fed the 20U diet at the end of the trial (week18). However, the gonad weight of urchins in the 20U treatment group remained significantly greater than urchins in the U-20U group at the end of the trial (Kruskal-Wallis ANOVA, P= 0.002). Gonad colour of urchins in the G-20U treatment became significantly lighter (ANOVA, P= 0.029) than those in the U-20U group after the change of diet. However, gonad lightness (L*) of urchins in treatment groups U-20U and G–20U did not differ significantly from those in the UG-20U and 20U treatment groups. All feed regimes were similar in terms of the gonad‟s redness (a*) and yellowness (b*), texture and firmness as well as gonad maturity at the end of the trial. This gonad enhancement study on wild collected adult T. gratilla has shown that somatic growth (urchin weight, test diameter and height) does not differ between the dietary treatments (fresh seaweeds and a formulated diet) tested in this study. The formulated feed (20U diet) does however enhance gonad growth of T. gratilla under farm conditions, supporting previous laboratory trials conducted on this species fed similar diets, indicating that sea urchins gonad enhancement can be cultured under farm conditions in South Africa.
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The role of gardening in improving community resilience in rural areas: a case study of Raymond Mhlaba, Port St Johns and Ingquza Hill Local Municipalities, Eastern Cape Province, South Africa
- Authors: Hendrick, Namhla Andiphile
- Date: 2019
- Subjects: Community gardens
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17224 , vital:40867
- Description: The increase of challenges in rural areas especially in developing countries has widened the vulnerability of rural people in the rural communities. This study has found that gardening has become the weapon to defend rural people and communities in developing countries against poverty and other hardships, since gardening in rural communities has the possibility to act as sustainable livelihood strategy. Semi structured questionnaire was used to collect primary data from smallholder farmers in the three local municipalities (Raymond Mhlaba, Port St Johns and Ingquza Hill local municipalities). The research investigated both home and community gardening. Multistage sampling was employed to select the sample. In stage one, the three Local Municipalities (LM’s) were purposively selected. In stage two, farmers were grouped into wards and communities and samples drawn in such a way that each group was well represented. This was followed by using quota sampling through the census statistics to determine farmers who are practising gardening whether it is community gardening or household gardening in these three local municipalities. Finally, random sampling was used to select a sample of 203 households that are undertaking some form of gardening (home or community) and are willingness to participate in the study. The Statistical Package for Social Sciences (SPSS version 24) was used to analyse the data by means of descriptive statistics and logistic regression model. The results confirm the strong links between home or community gardening and community resilience and that the influence is conditioned by a range of socioeconomic and demographic characteristics, including, age, occupation, access to extension officer and farming experience. In the light of the foregoing, it is recommended that households and communities be encouraged establish and operate home and/or community gardens as a strategy for coping with adversities that rural areas confront from time to time. In line with that, social interactions must be encouraged in communities because such interactions increase resilience in the sense that they build confidence in community members and a strong sense of belonging and trust. The role of education in enhancing access to information and knowledge that promote community resilience to disasters and shocks needs to be recognized and incorporated in community planning
- Full Text:
- Authors: Hendrick, Namhla Andiphile
- Date: 2019
- Subjects: Community gardens
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/17224 , vital:40867
- Description: The increase of challenges in rural areas especially in developing countries has widened the vulnerability of rural people in the rural communities. This study has found that gardening has become the weapon to defend rural people and communities in developing countries against poverty and other hardships, since gardening in rural communities has the possibility to act as sustainable livelihood strategy. Semi structured questionnaire was used to collect primary data from smallholder farmers in the three local municipalities (Raymond Mhlaba, Port St Johns and Ingquza Hill local municipalities). The research investigated both home and community gardening. Multistage sampling was employed to select the sample. In stage one, the three Local Municipalities (LM’s) were purposively selected. In stage two, farmers were grouped into wards and communities and samples drawn in such a way that each group was well represented. This was followed by using quota sampling through the census statistics to determine farmers who are practising gardening whether it is community gardening or household gardening in these three local municipalities. Finally, random sampling was used to select a sample of 203 households that are undertaking some form of gardening (home or community) and are willingness to participate in the study. The Statistical Package for Social Sciences (SPSS version 24) was used to analyse the data by means of descriptive statistics and logistic regression model. The results confirm the strong links between home or community gardening and community resilience and that the influence is conditioned by a range of socioeconomic and demographic characteristics, including, age, occupation, access to extension officer and farming experience. In the light of the foregoing, it is recommended that households and communities be encouraged establish and operate home and/or community gardens as a strategy for coping with adversities that rural areas confront from time to time. In line with that, social interactions must be encouraged in communities because such interactions increase resilience in the sense that they build confidence in community members and a strong sense of belonging and trust. The role of education in enhancing access to information and knowledge that promote community resilience to disasters and shocks needs to be recognized and incorporated in community planning
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The role of non-timber forest products (NTFPs) in the livelihoods of communities in Alfred Nzo District Municipality, Eastern Cape Province
- Authors: Thinyane, Zingisa
- Date: 2019
- Subjects: Non-timber forest products
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14737 , vital:40077
- Description: Non-timber forest products (NTFPs) are renewable natural resources which are harvested by local communities from the surrounding homesteads, fields, grazing lands, woodlands, grasslands and natural habitats. The term NTFP may be used in reference to biological products collected from the domesticated land, semidomesticated land or from the wild. This study examined the use of NTFPs in Alfred Nzo District Municipality, Eastern Cape Province, South Africa, assessing their consumption patterns and contribution to the household well-being. Data on NTFP identity and utilization in the study area were gathered through community focus group discussions and household surveys using semi-structured questionnaires between April 2017 and May 2018. A sample of 124 participants selected via snowball-sampling technique provided detailed accounts on diversity and utilization of NTFPs in the study area. A total of 59 species and eight extractable NTFPs were utilized by the communities in Alfred Nzo District Municipality. The identified eight use categories were herbal medicine (39.0%), edible plants and mushroom (18.0%), firewood (11%), bushmeat (10.0%), forage (9.0%), construction material (6.0%), ceremonial uses (2.0%) and others with miscellaneous uses (5.0%). Popular NTFPs with use values exceeding 0.50 include Agapanthus africanus (L.) Hoffmanns, Bulbine latifolia (L.f.) Spreng., Centella asiatica (L.) Urb, Elephantorrhiza elephantina (Burch.) Skeels, Hypoxis hemerocallidea Fisch., C.A. Mey & Avé-Lall and Leonotis leonurus (L.) R. Br., all used as herbal medicines, Agapanthus africanus (L.) (herbal medicine and ornamental), Datura stromonium L. (herbal medicine, forage and firewood), Dicerothamnus rhinocerotis (L.f) Koekemoer (herbal medicine and fumigant), Aepyceros melampus Lichtenstein, Pavo cristatus L., Struthio camelus L. and Xerus inauris Hemprich & Ehnrenberg as bushmeat. Information on diversity, consumption ii patterns and contribution of NTFPs to livelihood needs of households may enable policy makers and government officers to draft policies required for sustainable management of NTFPs.
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- Authors: Thinyane, Zingisa
- Date: 2019
- Subjects: Non-timber forest products
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14737 , vital:40077
- Description: Non-timber forest products (NTFPs) are renewable natural resources which are harvested by local communities from the surrounding homesteads, fields, grazing lands, woodlands, grasslands and natural habitats. The term NTFP may be used in reference to biological products collected from the domesticated land, semidomesticated land or from the wild. This study examined the use of NTFPs in Alfred Nzo District Municipality, Eastern Cape Province, South Africa, assessing their consumption patterns and contribution to the household well-being. Data on NTFP identity and utilization in the study area were gathered through community focus group discussions and household surveys using semi-structured questionnaires between April 2017 and May 2018. A sample of 124 participants selected via snowball-sampling technique provided detailed accounts on diversity and utilization of NTFPs in the study area. A total of 59 species and eight extractable NTFPs were utilized by the communities in Alfred Nzo District Municipality. The identified eight use categories were herbal medicine (39.0%), edible plants and mushroom (18.0%), firewood (11%), bushmeat (10.0%), forage (9.0%), construction material (6.0%), ceremonial uses (2.0%) and others with miscellaneous uses (5.0%). Popular NTFPs with use values exceeding 0.50 include Agapanthus africanus (L.) Hoffmanns, Bulbine latifolia (L.f.) Spreng., Centella asiatica (L.) Urb, Elephantorrhiza elephantina (Burch.) Skeels, Hypoxis hemerocallidea Fisch., C.A. Mey & Avé-Lall and Leonotis leonurus (L.) R. Br., all used as herbal medicines, Agapanthus africanus (L.) (herbal medicine and ornamental), Datura stromonium L. (herbal medicine, forage and firewood), Dicerothamnus rhinocerotis (L.f) Koekemoer (herbal medicine and fumigant), Aepyceros melampus Lichtenstein, Pavo cristatus L., Struthio camelus L. and Xerus inauris Hemprich & Ehnrenberg as bushmeat. Information on diversity, consumption ii patterns and contribution of NTFPs to livelihood needs of households may enable policy makers and government officers to draft policies required for sustainable management of NTFPs.
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