Gender possibilities in the African context as explored by Mariama Ba's So long a letter, Neshani Andrea's The purple violet of Oshaantu and Sindiwe Magona's Beauty gift
- Authors: Goremusandu, Tania
- Date: 2016
- Subjects: Women and literature Feminist fiction -- History and criticism Women authors, African
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10353/6469 , vital:29739
- Description: Gender oppression has been a significant discussion to the development of gender, cultural and feminist theories. The primary focus of this study is to investigate how patriarchal traditions, colonialism, and religious oppression force women to struggle under constrictions oppositional to empowerment. Thus, the project provides a comparative analysis of three texts from different African postcolonial societies by three African female writers: Mariama Bâ, Neshani Andreas and Sindiwe Magona. The author‟s biographies and historical context of their novels will be analyzed, as well as a summary of their stories will be included in order to provide the context for gender criticism. These writer‟s work; So Long a Letter, The Purple Violet of Oshaantu and Beauty‟s Gift depict patriarchal, cultural and religious laws which exist in Senegal, Namibia and South Africa, respectively, that limit the position of women. Therefore, this study will interrogate the experience of African women as inscribed in these selected texts, uncovering the literary expressions of gender oppression as well as the possibilities of empowerment. The selected texts will be analyzed through the lens of Gender studies, African feminism and Cultural studies. From these theories, the focus of the study is on the struggles of the female characters living in patriarchal societies as well as on the idea that gender is constructed socially and culturally in the African context. In conclusion, the emergence of these renowned female African writers together with the emancipation of African countries from colonial supremacy has opened a space for women to compensate and correct the stereotyped female images in African literature and post- colonial societies. Most contemporary African writers like Buchi Emecheta, Tsitsi Dangarembga, Sindiwe Magona, Mariama Bâ and Neshani Andreas have shown that women are seeking to attain empowerment. As a result, this study can be viewed as an opportunity to highlight such experiences by continuing to interrogate the writings of African women writers and to explore their gender-based themes so as to inform and or inspire the implementation of women empowerment. It will broaden and encourage further academic discussion in the field of Cultural studies and gender criticism of women‟s literature within the African context.
- Full Text:
- Date Issued: 2016
- Authors: Goremusandu, Tania
- Date: 2016
- Subjects: Women and literature Feminist fiction -- History and criticism Women authors, African
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10353/6469 , vital:29739
- Description: Gender oppression has been a significant discussion to the development of gender, cultural and feminist theories. The primary focus of this study is to investigate how patriarchal traditions, colonialism, and religious oppression force women to struggle under constrictions oppositional to empowerment. Thus, the project provides a comparative analysis of three texts from different African postcolonial societies by three African female writers: Mariama Bâ, Neshani Andreas and Sindiwe Magona. The author‟s biographies and historical context of their novels will be analyzed, as well as a summary of their stories will be included in order to provide the context for gender criticism. These writer‟s work; So Long a Letter, The Purple Violet of Oshaantu and Beauty‟s Gift depict patriarchal, cultural and religious laws which exist in Senegal, Namibia and South Africa, respectively, that limit the position of women. Therefore, this study will interrogate the experience of African women as inscribed in these selected texts, uncovering the literary expressions of gender oppression as well as the possibilities of empowerment. The selected texts will be analyzed through the lens of Gender studies, African feminism and Cultural studies. From these theories, the focus of the study is on the struggles of the female characters living in patriarchal societies as well as on the idea that gender is constructed socially and culturally in the African context. In conclusion, the emergence of these renowned female African writers together with the emancipation of African countries from colonial supremacy has opened a space for women to compensate and correct the stereotyped female images in African literature and post- colonial societies. Most contemporary African writers like Buchi Emecheta, Tsitsi Dangarembga, Sindiwe Magona, Mariama Bâ and Neshani Andreas have shown that women are seeking to attain empowerment. As a result, this study can be viewed as an opportunity to highlight such experiences by continuing to interrogate the writings of African women writers and to explore their gender-based themes so as to inform and or inspire the implementation of women empowerment. It will broaden and encourage further academic discussion in the field of Cultural studies and gender criticism of women‟s literature within the African context.
- Full Text:
- Date Issued: 2016
Generation of New Ecotoxicity Data for Salts Using Indigenous South African Freshwater Macroinvertebrate: Updating the National Salts Toxicity Database
- Mensah, Paul K, Mgaba, Ntombekhaya, Griffin, Neil J, Odume, Oghenekaro N, Palmer, Carolyn G
- Authors: Mensah, Paul K , Mgaba, Ntombekhaya , Griffin, Neil J , Odume, Oghenekaro N , Palmer, Carolyn G
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437854 , vital:73417 , ISBN 978-1-4312-0747-3 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/KV%20353.pdf
- Description: Scherman and Palmer (2013) reviewed the historical and current trends of Environmental Water Quality (EWQ) in South Africa. Based on the review, they identified research gaps for which they proposed a co-ordinated set of projects that need to be commissioned and executed to fill these gaps. These co-ordinated set of projects include update of TEACHA (Tool for Ecological Aquatic Chemical Habitat Assessment); update of the national salt toxicity database; integration of Resource Directed Measures (RDM) components (ie Ecological Reserve, Re-source Quality Objectives (RQOs) and Classification); integrating water quality and quantity; evaluation of the RDM participatory process based on research and current understandings of complex social-ecological systems and ecosystem services; and integrating RDM and SDC (Source Direct Control) to ensure coherent link between the two. The overarching aim of the above set of projects is to support implementa-tion of the National Water Resource Strategy 2 (NWRS2). Therefore, the main objective of this project to contribute to addressing the second research gap listed above (ie updating the national salt toxicity data-base). Noting that the database contains only data on single salts with nothing on salt mixtures, the project also generated binary salt mixtures data for the database, in addition to generating data for single salts.
- Full Text:
- Date Issued: 2016
- Authors: Mensah, Paul K , Mgaba, Ntombekhaya , Griffin, Neil J , Odume, Oghenekaro N , Palmer, Carolyn G
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/437854 , vital:73417 , ISBN 978-1-4312-0747-3 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/KV%20353.pdf
- Description: Scherman and Palmer (2013) reviewed the historical and current trends of Environmental Water Quality (EWQ) in South Africa. Based on the review, they identified research gaps for which they proposed a co-ordinated set of projects that need to be commissioned and executed to fill these gaps. These co-ordinated set of projects include update of TEACHA (Tool for Ecological Aquatic Chemical Habitat Assessment); update of the national salt toxicity database; integration of Resource Directed Measures (RDM) components (ie Ecological Reserve, Re-source Quality Objectives (RQOs) and Classification); integrating water quality and quantity; evaluation of the RDM participatory process based on research and current understandings of complex social-ecological systems and ecosystem services; and integrating RDM and SDC (Source Direct Control) to ensure coherent link between the two. The overarching aim of the above set of projects is to support implementa-tion of the National Water Resource Strategy 2 (NWRS2). Therefore, the main objective of this project to contribute to addressing the second research gap listed above (ie updating the national salt toxicity data-base). Noting that the database contains only data on single salts with nothing on salt mixtures, the project also generated binary salt mixtures data for the database, in addition to generating data for single salts.
- Full Text:
- Date Issued: 2016
Genetic and biological characterisation of a novel South African Cydia pomonella granulovirus (CpGV-SA) isolate
- Motsoeneng, Boitumelo Madika
- Authors: Motsoeneng, Boitumelo Madika
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:20503 , http://hdl.handle.net/10962/d1021266
- Description: The codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), is the primary pest of pome fruit cultivated worldwide. The control of this insect pest has been dependent on the frequent use of broad-spectrum chemical pesticides, which has led to the development of resistance in pest populations and negative effects on human health and the environment. The Betabaculovirus of C. pomonella has successfully been applied as a biological control agent in integrated pest management (IPM) programmes for the suppression of pest populations worldwide. Previously, all Cydia pomonella granulovirus (CpGV) biopesticides were based on a Mexican isolate (CpGV-M) and although these products are highly efficient at controlling C. pomonella, resistance cases have been reported across Europe. The identification of novel CpGV isolates as additional or alternative control agents to manage resistance is therefore necessary. This study aimed to genetically and biologically characterise a novel South African C. pomonella granulovirus isolate and to test its virulence against neonate larvae. Based on the morphology of the occlusion bodies observed using transmission electron microscopy, granuloviruses were recovered from diseased and dead larvae collected from an orchard in South Africa where no virus applications had been made. DNA was extracted and the identification of the isolated granulovirus was achieved through the PCR amplification and sequencing of the lef-8, lef-9, granulin and egt genes. Submission of the gene sequences to BLAST revealed high percentage identities to sequences from various CpGV isolates, resulting in the naming of the isolate in this study as the South African Cydia pomonella granulovirus (CpGV-SA) isolate. Phylogenetic analysis based on the single nucleotide polymorphisms (SNPs) detected in the lef-8, lef-9 and granulin nucleotide sequences grouped the South African isolate with CpGV-E2 (genome type B) and CpGV-S (genome type E). The CpGV-SA isolate was further genetically characterised by restriction endonuclease analysis and complete sequencing of the genomic DNA. Differences were observed for the BamHI, EcoRI, PstI and XhoI profiles of CpGV-SA in comparison to the respective profiles generated for CpGV-M extracted from a biopesticide, Carpovirusine® (Arysta Lifescience, France). Several genetic variations between the complete genome sequence of CpGV-SA and the reference isolate, CpGV-M1, as well as a recent genome submission of CpGV-M, both representing genome type A were observed. The complete genome analysis confirmed that CpGV-SA is genetically different from the Mexican CpGV isolate, used in thedevelopment of most biopesticides. In silico restriction profiles of the genome sequence obtained for CpGV-SA and genome sequences of genetically different CpGV isolates originating from Mexico (M1 and M), England (E2), Canada (S) and Iran (I12 and I07), available on the NCBI’s GenBank database confirmed that CpGV-SA is of mixed genotypes. Furthermore, the South African isolate shared the single common difference found in the pe38 gene of resistance overcoming isolates, which was the absence of an internal 24 nucleotide repeat present in CpGV-M1. In addition to the common difference, SNPs detected in the pe38 gene grouped the isolate with the CpGV-S isolate, suggesting that the CpGV-SA isolate is predominantly of genome type E. To determine the biological activity of CpGV-SA against neonate C. pomonella larvae, surface bioassays were conducted alongside CpGV-M (Carpovirusine®) bioassays. The LC50 and LC90 values for the South African isolate were 1.6 × 103 and 1.2 × 105 OBs/ml respectively. The LT50 was determined to be 135 hours. These values were similar to the values obtained for CpGV-M (Carpovirusine®). The results in this study suggest that a novel South African CpGV isolate of mixed genotypes, potentially able to overcome resistance in C. pomonella, with biological activity similar to CpGV-M (Carpovirusine®) and important for the control of C. pomonella was recovered. The CpGV-SA isolate could therefore potentially be developed into a biopesticide for use in resistance management strategies against C. pomonella populations in South Africa.
- Full Text:
- Date Issued: 2016
- Authors: Motsoeneng, Boitumelo Madika
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:20503 , http://hdl.handle.net/10962/d1021266
- Description: The codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), is the primary pest of pome fruit cultivated worldwide. The control of this insect pest has been dependent on the frequent use of broad-spectrum chemical pesticides, which has led to the development of resistance in pest populations and negative effects on human health and the environment. The Betabaculovirus of C. pomonella has successfully been applied as a biological control agent in integrated pest management (IPM) programmes for the suppression of pest populations worldwide. Previously, all Cydia pomonella granulovirus (CpGV) biopesticides were based on a Mexican isolate (CpGV-M) and although these products are highly efficient at controlling C. pomonella, resistance cases have been reported across Europe. The identification of novel CpGV isolates as additional or alternative control agents to manage resistance is therefore necessary. This study aimed to genetically and biologically characterise a novel South African C. pomonella granulovirus isolate and to test its virulence against neonate larvae. Based on the morphology of the occlusion bodies observed using transmission electron microscopy, granuloviruses were recovered from diseased and dead larvae collected from an orchard in South Africa where no virus applications had been made. DNA was extracted and the identification of the isolated granulovirus was achieved through the PCR amplification and sequencing of the lef-8, lef-9, granulin and egt genes. Submission of the gene sequences to BLAST revealed high percentage identities to sequences from various CpGV isolates, resulting in the naming of the isolate in this study as the South African Cydia pomonella granulovirus (CpGV-SA) isolate. Phylogenetic analysis based on the single nucleotide polymorphisms (SNPs) detected in the lef-8, lef-9 and granulin nucleotide sequences grouped the South African isolate with CpGV-E2 (genome type B) and CpGV-S (genome type E). The CpGV-SA isolate was further genetically characterised by restriction endonuclease analysis and complete sequencing of the genomic DNA. Differences were observed for the BamHI, EcoRI, PstI and XhoI profiles of CpGV-SA in comparison to the respective profiles generated for CpGV-M extracted from a biopesticide, Carpovirusine® (Arysta Lifescience, France). Several genetic variations between the complete genome sequence of CpGV-SA and the reference isolate, CpGV-M1, as well as a recent genome submission of CpGV-M, both representing genome type A were observed. The complete genome analysis confirmed that CpGV-SA is genetically different from the Mexican CpGV isolate, used in thedevelopment of most biopesticides. In silico restriction profiles of the genome sequence obtained for CpGV-SA and genome sequences of genetically different CpGV isolates originating from Mexico (M1 and M), England (E2), Canada (S) and Iran (I12 and I07), available on the NCBI’s GenBank database confirmed that CpGV-SA is of mixed genotypes. Furthermore, the South African isolate shared the single common difference found in the pe38 gene of resistance overcoming isolates, which was the absence of an internal 24 nucleotide repeat present in CpGV-M1. In addition to the common difference, SNPs detected in the pe38 gene grouped the isolate with the CpGV-S isolate, suggesting that the CpGV-SA isolate is predominantly of genome type E. To determine the biological activity of CpGV-SA against neonate C. pomonella larvae, surface bioassays were conducted alongside CpGV-M (Carpovirusine®) bioassays. The LC50 and LC90 values for the South African isolate were 1.6 × 103 and 1.2 × 105 OBs/ml respectively. The LT50 was determined to be 135 hours. These values were similar to the values obtained for CpGV-M (Carpovirusine®). The results in this study suggest that a novel South African CpGV isolate of mixed genotypes, potentially able to overcome resistance in C. pomonella, with biological activity similar to CpGV-M (Carpovirusine®) and important for the control of C. pomonella was recovered. The CpGV-SA isolate could therefore potentially be developed into a biopesticide for use in resistance management strategies against C. pomonella populations in South Africa.
- Full Text:
- Date Issued: 2016
Genetic structure and biogeography of three wrasse species (Labridae) within the Western Indian Ocean
- Authors: Mayekiso, Sisanda
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/1114 , vital:20021
- Description: The biogeography of wrasses within the Western Indian Ocean (WIO) is poorly understood, with regard to origins and genetic differentiation or connectivity among the regions of the WIO. This region is a good model for studying the influence of physical complexities and biogeographic breaks in shaping patterns of differentiation in wrasses. Three reef-associated fish species, Cheilio inermis, Thalassoma hebraicum and T. lunare, were selected to examine the factors that have influenced patterns of differentiation across the WIO. Each species was sampled from various localities of the WIO, the Red Sea and Indo-West Pacific Islands. Sequence data were generated from two mitochondrial gene fragments (cytochrome b and ATPase 6) and one nuclear locus (the first intron of the ribosomal protein S7 gene). Genetic analyses were used to calculate genetic diversity indices within species, which were then compared among species. The relationships among haplotypes and alleles were constructed using median-joining networks. Where necessary, neighbour-joining trees (NJ) were constructed to examine relationships among haplotypes and alleles for the Thalassoma species. Population structure was analysed using AMOVA and pairwise ФST to compare and calculate differentiation between the WIO localities. Mismatch distributions were used to examine population growth and decline or stability, and demographic parameters were used to calculate time of population expansion. There was high haplotype (h = 0.88 to 0.98) and low nucleotide diversities (π = 0.003 to 0.008) among all species for mitochondrial markers. For S7 intron I, high allelic (A = 0.95 to 0.98) and low nucleotide diversities (π = 0.002 to 0.014) were observed for all species. The pairwise ФST values revealed little to great (ФST = -0.02 to 0.67) genetic differentiation between localities, across all species for the three gene regions. The pairwise comparisons indicated the differentiation in C. inermis of Tanzania and Kenya from Mozambique and Nosy Be (Madagascar). The widespread C. inermis also revealed the differentiation of Kenya and Tanzania. For C. inermis, the AMOVAs of ATPase 6 and cytochrome b data indicated high differentiation among defined locality groups. The groups were defined according to geographic proximity. However, the AMOVA of the nuclear gene (S7 intron I) did not find variation among defined locality groups. Cheilio inermis revealed a sequence divergence of 0.4%. The divergence that was found in C. inermis was not enough to suggest a cryptic species within the WIO. Overall, the widespread and monotypic C. inermis revealed genetic differentiation within the WIO. Thalassoma hebraicum generally revealed little genetic differentiation across the WIO. The AMOVAs of the three gene regions showed no variation among specimens of the defined locality groups. However, some differentiation was found between localities. The pairwise comparisons of T. hebraicum revealed the differentiation of Seychelles from the African mainland and Madagascar. Southern Africa was observed to be differentiated from Nosy Be and Zanzibar. The observed differentiation could be caused by oceanic barriers such as the South Equatorial Current (SEQC), East African Coastal Current (EACC), and the Comoros Gyres and eddies in the Mozambique Channel, and Agulhas Current. Thalassoma lunare revealed genetic isolation between the WIO and the Red Sea as well as within the WIO. The genetic isolation between the WIO and the Red Sea is probably due to the historical isolation by the Bab al Mandab and contemporary barriers such as the cold upwelling cells in Somalia. The differentiation of Maldives from the African mainland and Seychelles could be due to distance and the upwelling cells created by monsoon winds. Mismatch distributions suggested that C. inermis and T. hebraicum had undergone demographic expansion during the Pleistocene (92 678 to 40 219 years ago). The results of the current study are similar to those from previous studies of WIO reef fish species, and the results of the present study could have potential implications for conservation and fisheries management. Single genetic markers and single species studies do not detect all barriers to dispersal in the WIO, thus they are insufficient to inform conservation management. Thus, the use of multispecies and genetic markers in the current study can be adopted by other studies of the marine taxa of the WIO.
- Full Text:
- Date Issued: 2016
- Authors: Mayekiso, Sisanda
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/1114 , vital:20021
- Description: The biogeography of wrasses within the Western Indian Ocean (WIO) is poorly understood, with regard to origins and genetic differentiation or connectivity among the regions of the WIO. This region is a good model for studying the influence of physical complexities and biogeographic breaks in shaping patterns of differentiation in wrasses. Three reef-associated fish species, Cheilio inermis, Thalassoma hebraicum and T. lunare, were selected to examine the factors that have influenced patterns of differentiation across the WIO. Each species was sampled from various localities of the WIO, the Red Sea and Indo-West Pacific Islands. Sequence data were generated from two mitochondrial gene fragments (cytochrome b and ATPase 6) and one nuclear locus (the first intron of the ribosomal protein S7 gene). Genetic analyses were used to calculate genetic diversity indices within species, which were then compared among species. The relationships among haplotypes and alleles were constructed using median-joining networks. Where necessary, neighbour-joining trees (NJ) were constructed to examine relationships among haplotypes and alleles for the Thalassoma species. Population structure was analysed using AMOVA and pairwise ФST to compare and calculate differentiation between the WIO localities. Mismatch distributions were used to examine population growth and decline or stability, and demographic parameters were used to calculate time of population expansion. There was high haplotype (h = 0.88 to 0.98) and low nucleotide diversities (π = 0.003 to 0.008) among all species for mitochondrial markers. For S7 intron I, high allelic (A = 0.95 to 0.98) and low nucleotide diversities (π = 0.002 to 0.014) were observed for all species. The pairwise ФST values revealed little to great (ФST = -0.02 to 0.67) genetic differentiation between localities, across all species for the three gene regions. The pairwise comparisons indicated the differentiation in C. inermis of Tanzania and Kenya from Mozambique and Nosy Be (Madagascar). The widespread C. inermis also revealed the differentiation of Kenya and Tanzania. For C. inermis, the AMOVAs of ATPase 6 and cytochrome b data indicated high differentiation among defined locality groups. The groups were defined according to geographic proximity. However, the AMOVA of the nuclear gene (S7 intron I) did not find variation among defined locality groups. Cheilio inermis revealed a sequence divergence of 0.4%. The divergence that was found in C. inermis was not enough to suggest a cryptic species within the WIO. Overall, the widespread and monotypic C. inermis revealed genetic differentiation within the WIO. Thalassoma hebraicum generally revealed little genetic differentiation across the WIO. The AMOVAs of the three gene regions showed no variation among specimens of the defined locality groups. However, some differentiation was found between localities. The pairwise comparisons of T. hebraicum revealed the differentiation of Seychelles from the African mainland and Madagascar. Southern Africa was observed to be differentiated from Nosy Be and Zanzibar. The observed differentiation could be caused by oceanic barriers such as the South Equatorial Current (SEQC), East African Coastal Current (EACC), and the Comoros Gyres and eddies in the Mozambique Channel, and Agulhas Current. Thalassoma lunare revealed genetic isolation between the WIO and the Red Sea as well as within the WIO. The genetic isolation between the WIO and the Red Sea is probably due to the historical isolation by the Bab al Mandab and contemporary barriers such as the cold upwelling cells in Somalia. The differentiation of Maldives from the African mainland and Seychelles could be due to distance and the upwelling cells created by monsoon winds. Mismatch distributions suggested that C. inermis and T. hebraicum had undergone demographic expansion during the Pleistocene (92 678 to 40 219 years ago). The results of the current study are similar to those from previous studies of WIO reef fish species, and the results of the present study could have potential implications for conservation and fisheries management. Single genetic markers and single species studies do not detect all barriers to dispersal in the WIO, thus they are insufficient to inform conservation management. Thus, the use of multispecies and genetic markers in the current study can be adopted by other studies of the marine taxa of the WIO.
- Full Text:
- Date Issued: 2016
Genetics, physiology, proteomics of quality protein maize inbred lines under drought and heat stress
- Authors: Pfunde, Cleopatra Nyaradzo
- Date: 2016
- Subjects: Corn Drought-tolerant plants Proteomics
- Language: English
- Type: Thesis , Masters/Doctoral , Crop Science
- Identifier: http://hdl.handle.net/10353/11696 , vital:39098
- Description: When plants perceive heat stress alone or in combination with drought, they activate several responses to synchronize development and molecular activities to ensure survival. In this study, a multidiscipline approach was adopted to investigate the plant genetics, proteomics and physiology for understanding the mechanisms underlying the adaptive response to combined drought and heat stress. The quality protein maize (QPM) inbred lines used had varied degrees of tolerance to both heat stress alone and in combination with drought. The overall objective of this study was to identify drought and heat tolerant germplasm that combine well under drought and heat stress for use in breeding programs to develop new QPM varieties. Initially, the genetic diversity among available inbred lines was estimated using two molecular markers, simple sequence repeats (SSRs) and single nucleotide polymorphisms (SNPs). The results indicated that moderate diversity exists among the QPM inbred lines which can be exploited to generate high performing hybrids. Cross combinations between QS26 and CIM2 and those between QS6 and CIM14 were selected as crosses likely to give substantial heterosis in the field because of the high genetic distances that were found between them using SNPs. Screening of inbred lines for drought and heat tolerance was done at the early germination and seedling stages. Differences in heat tolerance at both stages of growth were observed. Heat tolerant inbred lines at early germination stage had longer coleoptiles and radicles after recovery. The following inbred lines exhibited acquired thermo-tolerance, QS6, CIM7, QS17 and QS19, while CIM12, QS1, CIM21 and QS32 showed basal thermo-tolerance. At the early seedling stage inbred lines with significant differences (P< 0.001) in morpho-physiological traits were noted under heat stress alone and under combined drought and heat stress. However, no significant differences were noted for morpho-physiological measurements in the control treatment. Electron transport rate, sub-stomatal CO2, and stomatal conductance were significantly (P<0.001) reduced in response to combined drought and heat stress. Thus, drought coupled with heat stress resulted in stomatal closure, decreased photosynthetic rate, enhanced respiration and increased leaf temperature for susceptible inbred lines. The combined effects of drought and heat stress were more deleterious than the individual effect of heat stress alone as indicated by the reduction in dry weight. Based on the physiological parameters, biomass and tolerance indices, inbred lines QS22, CIM18 and QS6 showed tolerance to combined drought and heat stress, while CIM18, QS14 and QS30 exhibited thermo-tolerance. Inbred line CIM18 showed cross tolerance to combined drought and heat stress, and to heat stress alone. Further investigations into the comparative proteomic analysis of CIM18 (tolerant) with QS21 (susceptible) under combined drought and heat stress at seedling stage revealed that photosynthetic and stress related proteins were upregulated in CIM18. In addition, the abundance of heat shock proteins such as HSP70 and sHSP 17.8 kDa meant that CIM18 was better able to maintain cellular homeostasis and metabolism. The presence of metabolism related proteins meant that the energy needs of photosynthesis and other activities were met under drought and heat stress. Anti-oxidant enzymes such as glutathione s transferase were responsible for detoxification of reactive oxygen species induced by oxidative stress. These proteins mediated tolerance to combined stress in CIM18. The proteins that were micro-sequenced have previously been identified in individual drought and heat stress studies. The expression of these proteins under combined stress indicated that mechanisms from both stresses were pooled to confer tolerance in CIM18. Accordingly, the study proposes that CIM18 is a drought and heat tolerant QPM inbred line and is recommended for inclusion in breeding programs aimed at the development of drought and heat tolerant varieties. QPM has the potential to improve human nutrition in several rural households. The combining ability analysis of inbred lines revealed that GCA effects under combined drought and heat stress were significant for ears per plant, chlorophyll content, canopy temperature, anthesis silking interval, days to 50percent silking and ear length. Specific combining ability effects were significant for grain yield, days to 50percent anthesis, chlorophyll content and senescence. The study revealed that non-additive gene action was more important in determining grain yield under combined drought and heat stress. Inbred lines L2, L3, L7 and L3, L7 and L11 were good sources of genes for high grain yield under well-watered and combined drought and heat stress respectively. Cross combinations L3 x L13 (3.05 t/ha) and L5 x L9 (2.95 t/ha) were the best performing single cross hybrids for grain yield while cross combination L2 x L10 (1.33t/ha) was the least performing hybrid under combined stress conditions. Under well-watered conditions, the highest yielding crosses were between L2 x L13 (6.51t/ha) and L2 x L8 (6.46 t/ha). The inbred lines identified as sources of drought and heat tolerance and the high yielding cross combinations maybe useful for improving tolerance by generating hybrids or synthetic QPM maize varieties. The inbred lines which exhibited tolerance to both drought and heat stress were genetically diverse and were able to maintain photosynthesis and hence growth during stressful conditions. The ability of these genotypes to accumulate biomass or produce yield under stressful conditions highlights underlying mechanisms which need to be further exploited. While partial proteomic work was done in this study, a more comprehensive study looking into greater depth at the genes responsible for these mechanisms is paramount to fully utilize and/or transfer these genes to other desirable genotypes.
- Full Text:
- Date Issued: 2016
Genetics, physiology, proteomics of quality protein maize inbred lines under drought and heat stress
- Authors: Pfunde, Cleopatra Nyaradzo
- Date: 2016
- Subjects: Corn Drought-tolerant plants Proteomics
- Language: English
- Type: Thesis , Masters/Doctoral , Crop Science
- Identifier: http://hdl.handle.net/10353/11696 , vital:39098
- Description: When plants perceive heat stress alone or in combination with drought, they activate several responses to synchronize development and molecular activities to ensure survival. In this study, a multidiscipline approach was adopted to investigate the plant genetics, proteomics and physiology for understanding the mechanisms underlying the adaptive response to combined drought and heat stress. The quality protein maize (QPM) inbred lines used had varied degrees of tolerance to both heat stress alone and in combination with drought. The overall objective of this study was to identify drought and heat tolerant germplasm that combine well under drought and heat stress for use in breeding programs to develop new QPM varieties. Initially, the genetic diversity among available inbred lines was estimated using two molecular markers, simple sequence repeats (SSRs) and single nucleotide polymorphisms (SNPs). The results indicated that moderate diversity exists among the QPM inbred lines which can be exploited to generate high performing hybrids. Cross combinations between QS26 and CIM2 and those between QS6 and CIM14 were selected as crosses likely to give substantial heterosis in the field because of the high genetic distances that were found between them using SNPs. Screening of inbred lines for drought and heat tolerance was done at the early germination and seedling stages. Differences in heat tolerance at both stages of growth were observed. Heat tolerant inbred lines at early germination stage had longer coleoptiles and radicles after recovery. The following inbred lines exhibited acquired thermo-tolerance, QS6, CIM7, QS17 and QS19, while CIM12, QS1, CIM21 and QS32 showed basal thermo-tolerance. At the early seedling stage inbred lines with significant differences (P< 0.001) in morpho-physiological traits were noted under heat stress alone and under combined drought and heat stress. However, no significant differences were noted for morpho-physiological measurements in the control treatment. Electron transport rate, sub-stomatal CO2, and stomatal conductance were significantly (P<0.001) reduced in response to combined drought and heat stress. Thus, drought coupled with heat stress resulted in stomatal closure, decreased photosynthetic rate, enhanced respiration and increased leaf temperature for susceptible inbred lines. The combined effects of drought and heat stress were more deleterious than the individual effect of heat stress alone as indicated by the reduction in dry weight. Based on the physiological parameters, biomass and tolerance indices, inbred lines QS22, CIM18 and QS6 showed tolerance to combined drought and heat stress, while CIM18, QS14 and QS30 exhibited thermo-tolerance. Inbred line CIM18 showed cross tolerance to combined drought and heat stress, and to heat stress alone. Further investigations into the comparative proteomic analysis of CIM18 (tolerant) with QS21 (susceptible) under combined drought and heat stress at seedling stage revealed that photosynthetic and stress related proteins were upregulated in CIM18. In addition, the abundance of heat shock proteins such as HSP70 and sHSP 17.8 kDa meant that CIM18 was better able to maintain cellular homeostasis and metabolism. The presence of metabolism related proteins meant that the energy needs of photosynthesis and other activities were met under drought and heat stress. Anti-oxidant enzymes such as glutathione s transferase were responsible for detoxification of reactive oxygen species induced by oxidative stress. These proteins mediated tolerance to combined stress in CIM18. The proteins that were micro-sequenced have previously been identified in individual drought and heat stress studies. The expression of these proteins under combined stress indicated that mechanisms from both stresses were pooled to confer tolerance in CIM18. Accordingly, the study proposes that CIM18 is a drought and heat tolerant QPM inbred line and is recommended for inclusion in breeding programs aimed at the development of drought and heat tolerant varieties. QPM has the potential to improve human nutrition in several rural households. The combining ability analysis of inbred lines revealed that GCA effects under combined drought and heat stress were significant for ears per plant, chlorophyll content, canopy temperature, anthesis silking interval, days to 50percent silking and ear length. Specific combining ability effects were significant for grain yield, days to 50percent anthesis, chlorophyll content and senescence. The study revealed that non-additive gene action was more important in determining grain yield under combined drought and heat stress. Inbred lines L2, L3, L7 and L3, L7 and L11 were good sources of genes for high grain yield under well-watered and combined drought and heat stress respectively. Cross combinations L3 x L13 (3.05 t/ha) and L5 x L9 (2.95 t/ha) were the best performing single cross hybrids for grain yield while cross combination L2 x L10 (1.33t/ha) was the least performing hybrid under combined stress conditions. Under well-watered conditions, the highest yielding crosses were between L2 x L13 (6.51t/ha) and L2 x L8 (6.46 t/ha). The inbred lines identified as sources of drought and heat tolerance and the high yielding cross combinations maybe useful for improving tolerance by generating hybrids or synthetic QPM maize varieties. The inbred lines which exhibited tolerance to both drought and heat stress were genetically diverse and were able to maintain photosynthesis and hence growth during stressful conditions. The ability of these genotypes to accumulate biomass or produce yield under stressful conditions highlights underlying mechanisms which need to be further exploited. While partial proteomic work was done in this study, a more comprehensive study looking into greater depth at the genes responsible for these mechanisms is paramount to fully utilize and/or transfer these genes to other desirable genotypes.
- Full Text:
- Date Issued: 2016
Genotypic and phenotypic characterization of enterococci from cow dung and environmental water sources in three selected dairy farms in Amathole District
- Authors: Tanih, Godfred Ngu
- Date: 2016
- Subjects: Enterobacteriaceae Water -- Microbiology Enterococcus faecalis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2348 , vital:27755
- Description: Enterococcus species are integral members of the gastrointestinal microfloral of humans, animals, birds, as well as insects. Their presence in water and food has been greatly associated with faecal contamination. This study was aimed at evaluating the incidence of Enterococcus species in cow dung and environmental water sources in three commercial dairy farms. In addition, their antibiotic profiles were determined as well as resistance and virulence genes. Furthermore, the genetic relatedness of the isolates was determined by molecular typing method (RAPD PCR). Three hundred and thirty four water and faecal samples consisting of 117, 116 and 101 were collected from Seven Star Middle Drift and Fort Hare Dairy trusts respectively. Of the 334 samples collected, 289 were of faecal origin and 45 from water sources within the farms. All samples were screened for enterococci using culture base growth media and molecular methods targeting the tuf gene. Speciation was done using species-specific primers and the incidences of various species within the farms determined. Furthermore resistance to antibiotics and multidrug-resistant phenotypes were established using the disk diffusion method. Genes coding for virulence and resistance were also determined. From the samples collected, 313 (289 faecal and 24 water) presumptive enteroccocci were isolated, 305 of 313 (97.45 percent) were confirmed as Enterococcus of which 239 of 305 (78.38 percent) were identified as E. hirae, 15 of 305 (4.92 percent) as E. faecium, 12/305 (3.93 percent) as E. durans, 6 of 305 (1.97 percent) as E. faecalis and 33 of 305 (10.82 percent) were unidentified. Out of the five virulence genes that were targeted in the study only gelE (71.80 percent of 219/305) and ace (27.2 percent 83/305) were present in the isolates. Phenotypic resistance to antibiotics was observed is in all twelve antibiotics tested with multidrug resistance phenotypes detected in some enterococcal isolates most predominant in Seven Star and Middledrift dairy trust. Finally RAPD profiles of the isolates showed high relatedness between the strains from water and cow dung sources in all three commercial dairy farms suggesting possible contamination from cow dung to the water sources or vice versa.
- Full Text:
- Date Issued: 2016
- Authors: Tanih, Godfred Ngu
- Date: 2016
- Subjects: Enterobacteriaceae Water -- Microbiology Enterococcus faecalis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2348 , vital:27755
- Description: Enterococcus species are integral members of the gastrointestinal microfloral of humans, animals, birds, as well as insects. Their presence in water and food has been greatly associated with faecal contamination. This study was aimed at evaluating the incidence of Enterococcus species in cow dung and environmental water sources in three commercial dairy farms. In addition, their antibiotic profiles were determined as well as resistance and virulence genes. Furthermore, the genetic relatedness of the isolates was determined by molecular typing method (RAPD PCR). Three hundred and thirty four water and faecal samples consisting of 117, 116 and 101 were collected from Seven Star Middle Drift and Fort Hare Dairy trusts respectively. Of the 334 samples collected, 289 were of faecal origin and 45 from water sources within the farms. All samples were screened for enterococci using culture base growth media and molecular methods targeting the tuf gene. Speciation was done using species-specific primers and the incidences of various species within the farms determined. Furthermore resistance to antibiotics and multidrug-resistant phenotypes were established using the disk diffusion method. Genes coding for virulence and resistance were also determined. From the samples collected, 313 (289 faecal and 24 water) presumptive enteroccocci were isolated, 305 of 313 (97.45 percent) were confirmed as Enterococcus of which 239 of 305 (78.38 percent) were identified as E. hirae, 15 of 305 (4.92 percent) as E. faecium, 12/305 (3.93 percent) as E. durans, 6 of 305 (1.97 percent) as E. faecalis and 33 of 305 (10.82 percent) were unidentified. Out of the five virulence genes that were targeted in the study only gelE (71.80 percent of 219/305) and ace (27.2 percent 83/305) were present in the isolates. Phenotypic resistance to antibiotics was observed is in all twelve antibiotics tested with multidrug resistance phenotypes detected in some enterococcal isolates most predominant in Seven Star and Middledrift dairy trust. Finally RAPD profiles of the isolates showed high relatedness between the strains from water and cow dung sources in all three commercial dairy farms suggesting possible contamination from cow dung to the water sources or vice versa.
- Full Text:
- Date Issued: 2016
Geochemical exploration for copper - cobalt in the Democratic Republic of Congo, Central African Copperbelt: a case study on PR851
- Authors: Katombe-Kisumbule, Paul
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3035 , vital:20354
- Description: The PR851 licence area is located at about 80 km west from the town of Likasi in the district of Haut-Katanga and 175 km north-west of Lubumbashi, the capital city of Katanga Province in the Democratic Republic of Congo. The exploration licence was granted by the government of the Democratic Republic of Congo to First Quantum Minerals Ltd through its Congolese subsidiary Compagnie Minière de Sakania Sprl (CoMiSa Sprl) under certificate N˚ CAMI/CR/70/2003 on the 10th of October 2003 for a period of 5 years with a possibility of renewal for 3 years in respect to the new Congolese mining code. The PR851 area lies on fragments of Mines Subgroup rocks of the Roan Group in the Congolese Copperbelt where most of the Cu-Co and stratiform-stratabound deposits such as Kipushi, Ruashi-Etoile, Kinsevere, Kipoi, Luishya, Luswishi, Shituru, Kamoya, Kambove, Tenke- Fungurume, Shinkolobwe, Swambo, Mindingi and Kamoto among others are found. During the 20th century, the Union Minière du Haut Katanga (U.M.H.K.) undertook mineral exploration in the Congolese Copperbelt and numerous copper- and cobalt-occurrences were identified (for instance Kibamba copper occurrence in PR851 area). From 2003, the Compagnie Minière de Sakania Sprl initiated a grassroots exploration program in PR851 area and geochemical exploration survey as one of the mineral exploration tools was implemented to aim at detecting copper and cobalt concentration in soil. The B horizon of the thick tropical soil in the area was sampled and soil samples were sent to Genalysis laboratories in Johannesburg, Republic of South Africa for main chemical analysis of Cu and Co only, whereas 10% of analyzed samples were dispatched to Perth, Western Australia for quality control analysis. Thresholds for anomalies of copper and cobalt were defined by literature comparison, standard deviations and spatial analysis. The anomalies were tested at a later stage by reverse circulation / diamond drilling during the year of 2005 to 2008 and the Cu-Co resources were estimated by Digital Mining Services of Harare, Zimbabwe in the year of 2008. Geological logging of chips from reverse circulation and diamond drill cores revealed that copper mineralization is represented by malachite, chrysocolla, chalcopyrite and bornite whereas cobalt mineralization appeared in form of heterogenite. The source of supergene mineralization remains unknown. Recommendations have been made to undertake more geological exploration work in order to fully investigate the geological setting and structural architecture of the region, which may result in a better understanding of the Cu-Co mineralization system and ore genesis. The latter has been no consensus up-to-date and different theories have been proposed to discuss the ore genesis, including syn- and dia- genetic, synorogenic and sulphide remobilization to late-to-post- orogenic Cu-Zn-Pb Kipushi-type deposit. However, geological observations favored that the diagenetic and syngenetic models are applicable to numerous deposits in the Central African Copperbelt.
- Full Text:
- Date Issued: 2016
- Authors: Katombe-Kisumbule, Paul
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3035 , vital:20354
- Description: The PR851 licence area is located at about 80 km west from the town of Likasi in the district of Haut-Katanga and 175 km north-west of Lubumbashi, the capital city of Katanga Province in the Democratic Republic of Congo. The exploration licence was granted by the government of the Democratic Republic of Congo to First Quantum Minerals Ltd through its Congolese subsidiary Compagnie Minière de Sakania Sprl (CoMiSa Sprl) under certificate N˚ CAMI/CR/70/2003 on the 10th of October 2003 for a period of 5 years with a possibility of renewal for 3 years in respect to the new Congolese mining code. The PR851 area lies on fragments of Mines Subgroup rocks of the Roan Group in the Congolese Copperbelt where most of the Cu-Co and stratiform-stratabound deposits such as Kipushi, Ruashi-Etoile, Kinsevere, Kipoi, Luishya, Luswishi, Shituru, Kamoya, Kambove, Tenke- Fungurume, Shinkolobwe, Swambo, Mindingi and Kamoto among others are found. During the 20th century, the Union Minière du Haut Katanga (U.M.H.K.) undertook mineral exploration in the Congolese Copperbelt and numerous copper- and cobalt-occurrences were identified (for instance Kibamba copper occurrence in PR851 area). From 2003, the Compagnie Minière de Sakania Sprl initiated a grassroots exploration program in PR851 area and geochemical exploration survey as one of the mineral exploration tools was implemented to aim at detecting copper and cobalt concentration in soil. The B horizon of the thick tropical soil in the area was sampled and soil samples were sent to Genalysis laboratories in Johannesburg, Republic of South Africa for main chemical analysis of Cu and Co only, whereas 10% of analyzed samples were dispatched to Perth, Western Australia for quality control analysis. Thresholds for anomalies of copper and cobalt were defined by literature comparison, standard deviations and spatial analysis. The anomalies were tested at a later stage by reverse circulation / diamond drilling during the year of 2005 to 2008 and the Cu-Co resources were estimated by Digital Mining Services of Harare, Zimbabwe in the year of 2008. Geological logging of chips from reverse circulation and diamond drill cores revealed that copper mineralization is represented by malachite, chrysocolla, chalcopyrite and bornite whereas cobalt mineralization appeared in form of heterogenite. The source of supergene mineralization remains unknown. Recommendations have been made to undertake more geological exploration work in order to fully investigate the geological setting and structural architecture of the region, which may result in a better understanding of the Cu-Co mineralization system and ore genesis. The latter has been no consensus up-to-date and different theories have been proposed to discuss the ore genesis, including syn- and dia- genetic, synorogenic and sulphide remobilization to late-to-post- orogenic Cu-Zn-Pb Kipushi-type deposit. However, geological observations favored that the diagenetic and syngenetic models are applicable to numerous deposits in the Central African Copperbelt.
- Full Text:
- Date Issued: 2016
Geology, regional diamond exploration and diamond provenance of the proterozoic diamondiferous Umkondo conglomerates, Umkondo group, eastern Zimbabwe
- Authors: Zhou, Takawira
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3598 , vital:20528
- Description: The Umkondo Sedimentary Basin in eastern Zimbabwe has been studied by various individuals and organizations since 1901. Their interest had been in finding limestone and beryl and base metal deposits, especially copper, iron and uranium, but these occurrences had proved to be of no economic value (Watson, 1969). The recent discovery of placer diamonds within the Proterozoic basal conglomerates of the Umkondo Sedimentary Basin has now attracted worldwide interest in the basin’s diamond economic potential, in understanding of the geology, and the diamond provenance of the Umkondo conglomerates. The Umkondo Sedimentary Basin basal conglomerate placer deposit might narrowly be defined as a mega-placer because of its sheer large size and high grades, especially on the 70,000 hectare western margin diamond dispersion halo where alluvial diamonds are being mined. Bluck, et al., (2005, pp 213) defines a diamond mega-placer as: . . . a number of linked deposits that are a result of one or a continuous process of transportation and deposition and holds or have held at least >= 50 million carats at >= 95% gem quality, for example, the Orange-Vaal dispersal, off the Kaapvaal craton in South Africa. On craton placers are residual, and transient placers are eroded and deposited into the exit drainage, while terminal placers, the final depositories of diamonds with the highest chances of being mega-placers are deposited into terminal basins like oceans and foreland basins. Though data is limited at the moment, the Umkondo conglomerates caratage is likely to run into hundreds of millions of carats, with a diamond gem content of between twenty and twenty-five percent, as is indicated from recent diamond production data. The greater part of the Umkondo diamonds are likely to be lodged beneath the deep gravels of the Middle and Lower Save River basin, because small remnant tilted mountain blocks and inselbergs forming the caps of hills are what remains of the host conglomerate on the western margin of the Umkondo Basin. Areas to be examined in this document will be the geology; the mode of formation of the Umkondo basin and its sedimentary system; the regional kimberlite exploration around the basin; and diamond production in the Marange diamond field, in order to come up with indications of the provenance of the diamonds within the Umkondo conglomerates. The kimberlite clusters in and around the Umkondo sedimentary basin have all proved to be barren or only nominally diamondiferous and that the kimberlites are between 200Ma and 500Ma and thus much younger than the greater than 1.1Ga Umkondo diamondiferous conglomerates. Studies so far undertaken have not managed to point to the origin, or provenance, of the Umkondo or Marange diamonds, which were discovered on the western edge of the Umkondo Basin and in the east of the basin below the Chimanimani Mountains along the Haroni River. This paper is an attempt to clear up some of the misconceptions surrounding the Marange diamond deposit and to raise interest in the urgent rquirement to study and understand the Umkondo Basin and the origin of its diamonds. The only meaningful studies on diamond occurrence and diamond exploration of the basin were undertaken from 1996 to 2006 by Kimberlitic Searches Zimbabwe (Pvt) Ltd, the then Zimbabwe kimberlite exploration arm of De Beers, Zimbabwe, in their quest to find kimberlites, which were thought to be related to the Umkondo alluvial diamond deposit. As will be shown in the following chapters, many of the discovered kimberlites range from very low grade to non-diamondiferous, and are much younger than the Umkondo conglomerates, whose diamonds are in turn a great deal older. Thus the basic question concerning the origin or provenance of the Umkondo placer diamonds still remains unresolved. Because of the sheer size of the basin, modern, wide-area-coverage, geophysical exploration methods become appropriate to effectively generate diamond potential targets for further examination. This document will attempt to collate various data available to paint a true picture of the state of exploration within the Umkondo Basin.
- Full Text:
- Date Issued: 2016
- Authors: Zhou, Takawira
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3598 , vital:20528
- Description: The Umkondo Sedimentary Basin in eastern Zimbabwe has been studied by various individuals and organizations since 1901. Their interest had been in finding limestone and beryl and base metal deposits, especially copper, iron and uranium, but these occurrences had proved to be of no economic value (Watson, 1969). The recent discovery of placer diamonds within the Proterozoic basal conglomerates of the Umkondo Sedimentary Basin has now attracted worldwide interest in the basin’s diamond economic potential, in understanding of the geology, and the diamond provenance of the Umkondo conglomerates. The Umkondo Sedimentary Basin basal conglomerate placer deposit might narrowly be defined as a mega-placer because of its sheer large size and high grades, especially on the 70,000 hectare western margin diamond dispersion halo where alluvial diamonds are being mined. Bluck, et al., (2005, pp 213) defines a diamond mega-placer as: . . . a number of linked deposits that are a result of one or a continuous process of transportation and deposition and holds or have held at least >= 50 million carats at >= 95% gem quality, for example, the Orange-Vaal dispersal, off the Kaapvaal craton in South Africa. On craton placers are residual, and transient placers are eroded and deposited into the exit drainage, while terminal placers, the final depositories of diamonds with the highest chances of being mega-placers are deposited into terminal basins like oceans and foreland basins. Though data is limited at the moment, the Umkondo conglomerates caratage is likely to run into hundreds of millions of carats, with a diamond gem content of between twenty and twenty-five percent, as is indicated from recent diamond production data. The greater part of the Umkondo diamonds are likely to be lodged beneath the deep gravels of the Middle and Lower Save River basin, because small remnant tilted mountain blocks and inselbergs forming the caps of hills are what remains of the host conglomerate on the western margin of the Umkondo Basin. Areas to be examined in this document will be the geology; the mode of formation of the Umkondo basin and its sedimentary system; the regional kimberlite exploration around the basin; and diamond production in the Marange diamond field, in order to come up with indications of the provenance of the diamonds within the Umkondo conglomerates. The kimberlite clusters in and around the Umkondo sedimentary basin have all proved to be barren or only nominally diamondiferous and that the kimberlites are between 200Ma and 500Ma and thus much younger than the greater than 1.1Ga Umkondo diamondiferous conglomerates. Studies so far undertaken have not managed to point to the origin, or provenance, of the Umkondo or Marange diamonds, which were discovered on the western edge of the Umkondo Basin and in the east of the basin below the Chimanimani Mountains along the Haroni River. This paper is an attempt to clear up some of the misconceptions surrounding the Marange diamond deposit and to raise interest in the urgent rquirement to study and understand the Umkondo Basin and the origin of its diamonds. The only meaningful studies on diamond occurrence and diamond exploration of the basin were undertaken from 1996 to 2006 by Kimberlitic Searches Zimbabwe (Pvt) Ltd, the then Zimbabwe kimberlite exploration arm of De Beers, Zimbabwe, in their quest to find kimberlites, which were thought to be related to the Umkondo alluvial diamond deposit. As will be shown in the following chapters, many of the discovered kimberlites range from very low grade to non-diamondiferous, and are much younger than the Umkondo conglomerates, whose diamonds are in turn a great deal older. Thus the basic question concerning the origin or provenance of the Umkondo placer diamonds still remains unresolved. Because of the sheer size of the basin, modern, wide-area-coverage, geophysical exploration methods become appropriate to effectively generate diamond potential targets for further examination. This document will attempt to collate various data available to paint a true picture of the state of exploration within the Umkondo Basin.
- Full Text:
- Date Issued: 2016
Geospatial technologies and indigenous Knowledge Systems:
- Authors: Aswani, Shankar
- Date: 2016
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/145448 , vital:38439 , ISBN 9781315181523 , https://www.taylorfrancis.com/books/e/9781315181523/chapters/10.1201/9781315181523-18
- Description: During the twentieth and twenty-first centuries, pressure on coastal ecosystems has amplified and resulted in the widespread degradation of adjacent marine and terrestrial habitats globally (Burke et al., 2001). The ecosystem services provided by coastal habitats, including coastal protection and food procurement, have been heavily compromised by anthropogenic disturbance such as overfishing, pollution, sedimentation and alteration of coastal vegetation (Costanza et al., 1997; Agardy et al., 2009). In the context of small islands, this continued degradation in tandem with the ongoing effects of climate change is putting the livelihoods of coastal peoples at risk (e.g. Bell et al., 2009). While international efforts at curtailing these negative trends are ongoing, many researchers are working directly with coastal local/ indigenous communities to seek more effective management of coastal terrestrial and marine resources. Among various approaches, researchers are increasingly incorporating local knowledge systems for designing resource management and conservation plans (e.g. Gadgil et al., 1993).
- Full Text:
- Date Issued: 2016
- Authors: Aswani, Shankar
- Date: 2016
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/145448 , vital:38439 , ISBN 9781315181523 , https://www.taylorfrancis.com/books/e/9781315181523/chapters/10.1201/9781315181523-18
- Description: During the twentieth and twenty-first centuries, pressure on coastal ecosystems has amplified and resulted in the widespread degradation of adjacent marine and terrestrial habitats globally (Burke et al., 2001). The ecosystem services provided by coastal habitats, including coastal protection and food procurement, have been heavily compromised by anthropogenic disturbance such as overfishing, pollution, sedimentation and alteration of coastal vegetation (Costanza et al., 1997; Agardy et al., 2009). In the context of small islands, this continued degradation in tandem with the ongoing effects of climate change is putting the livelihoods of coastal peoples at risk (e.g. Bell et al., 2009). While international efforts at curtailing these negative trends are ongoing, many researchers are working directly with coastal local/ indigenous communities to seek more effective management of coastal terrestrial and marine resources. Among various approaches, researchers are increasingly incorporating local knowledge systems for designing resource management and conservation plans (e.g. Gadgil et al., 1993).
- Full Text:
- Date Issued: 2016
Global proliferation of cephalopods
- Doubleday, Zoë A, Prowse, Thomas A A, Arkhipkin, Alexander, Pierce, Graham J, Semmens, Jayson, Steer, Michael, Leporati, Stephen C, Lourenço, Sílvia, Quetglas, Antoni, Sauer, Warwick H H, Gillanders, Bronwyn M
- Authors: Doubleday, Zoë A , Prowse, Thomas A A , Arkhipkin, Alexander , Pierce, Graham J , Semmens, Jayson , Steer, Michael , Leporati, Stephen C , Lourenço, Sílvia , Quetglas, Antoni , Sauer, Warwick H H , Gillanders, Bronwyn M
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124560 , vital:35628 , https://doi.10.1016/j.cub.2016.04.002
- Description: Human activities have substantially changed the world’s oceans in recent decades, altering marine food webs, habitats and biogeochemical processes [1]. Cephalopods (squid, cuttlefish and octopuses) have a unique set of biological traits, including rapid growth, short lifespans and strong life-history plasticity, allowing them to adapt quickly to changing environmental conditions [2–4]. There has been growing speculation that cephalopod populations are proliferating in response to a changing environment, a perception fuelled by increasing trends in cephalopod fisheries catch [4,5]. To investigate long-term trends in cephalopod abundance, we assembled global time-series of cephalopod catch rates (catch per unit of fishing or sampling effort). We show that cephalopod populations have increased over the last six decades, a result that was remarkably consistent across a highly diverse set of cephalopod taxa. Positive trends were also evident for both fisheries-dependent and fisheries independent time-series, suggesting that trends are not solely due to factors associated with developing fisheries. Our results suggest that large-scale, directional processes, common to a range of coastal and oceanic environments, are responsible. This study presents the first evidence that cephalopod populations have increased globally, indicating that these ecologically and commercially important invertebrates may have benefited from a changing ocean environment.
- Full Text:
- Date Issued: 2016
- Authors: Doubleday, Zoë A , Prowse, Thomas A A , Arkhipkin, Alexander , Pierce, Graham J , Semmens, Jayson , Steer, Michael , Leporati, Stephen C , Lourenço, Sílvia , Quetglas, Antoni , Sauer, Warwick H H , Gillanders, Bronwyn M
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124560 , vital:35628 , https://doi.10.1016/j.cub.2016.04.002
- Description: Human activities have substantially changed the world’s oceans in recent decades, altering marine food webs, habitats and biogeochemical processes [1]. Cephalopods (squid, cuttlefish and octopuses) have a unique set of biological traits, including rapid growth, short lifespans and strong life-history plasticity, allowing them to adapt quickly to changing environmental conditions [2–4]. There has been growing speculation that cephalopod populations are proliferating in response to a changing environment, a perception fuelled by increasing trends in cephalopod fisheries catch [4,5]. To investigate long-term trends in cephalopod abundance, we assembled global time-series of cephalopod catch rates (catch per unit of fishing or sampling effort). We show that cephalopod populations have increased over the last six decades, a result that was remarkably consistent across a highly diverse set of cephalopod taxa. Positive trends were also evident for both fisheries-dependent and fisheries independent time-series, suggesting that trends are not solely due to factors associated with developing fisheries. Our results suggest that large-scale, directional processes, common to a range of coastal and oceanic environments, are responsible. This study presents the first evidence that cephalopod populations have increased globally, indicating that these ecologically and commercially important invertebrates may have benefited from a changing ocean environment.
- Full Text:
- Date Issued: 2016
Goeie maniere en etiket
- Authors: Van Staden, Antoinique
- Date: 2016
- Language: Afrikaans , English
- Type: Thesis , Masters , MA
- Identifier: vital:6011 , http://hdl.handle.net/10962/d1021226
- Description: This bilingual collection of short stories combines the fairy tale form and the Bizarro genre to explore the value system ingrained in me at a very early age via my conservative Afrikaans upbringing. To my mind the four characteristics of the fairy tale form as identified by Kate Bernheimer (in her path-breaking essay “Fairy Tale is form, Form is Fairy Tale”) namely flatness, abstraction, intuitive logic and normalized magic, also apply to the Bizarro genre. This intersection is exemplified by some of Bernheimer's own fiction, as well as the fiction of Aimee Bender and Lucy Corin, among others, all of whom have influenced my writing. , Hierdie tweetalige versameling kortverhale kombineer sprokieselemente met die van die Bizarro-genre, om die waardesisteem wat van kleins af deur my konserwatiewe Afrikaanse opvoeding by my ingeprent is, te ondersoek. Die vier eienskappe van die sprokie word deur Kate Bernheimer in haar baanbrekende opstel Fairy tale is form, Form is fairy tale uitgelê as: ’n onbetrokke verteller, abstraksie, instinktiewe logika en genormaliseerde towerkuns. Na my mening is dié vier eienskappe ook op die Bizarro-genre van toepassing. Hierdie oorvleuling is sigbaar in Bernheimer se fiksie en ook onder andere Lucy Corin en Aimee Bender s'n – skrywers wat my werk beïnvloed het. , This thesis is presented in two parts: Afrikaans and English.
- Full Text:
- Date Issued: 2016
- Authors: Van Staden, Antoinique
- Date: 2016
- Language: Afrikaans , English
- Type: Thesis , Masters , MA
- Identifier: vital:6011 , http://hdl.handle.net/10962/d1021226
- Description: This bilingual collection of short stories combines the fairy tale form and the Bizarro genre to explore the value system ingrained in me at a very early age via my conservative Afrikaans upbringing. To my mind the four characteristics of the fairy tale form as identified by Kate Bernheimer (in her path-breaking essay “Fairy Tale is form, Form is Fairy Tale”) namely flatness, abstraction, intuitive logic and normalized magic, also apply to the Bizarro genre. This intersection is exemplified by some of Bernheimer's own fiction, as well as the fiction of Aimee Bender and Lucy Corin, among others, all of whom have influenced my writing. , Hierdie tweetalige versameling kortverhale kombineer sprokieselemente met die van die Bizarro-genre, om die waardesisteem wat van kleins af deur my konserwatiewe Afrikaanse opvoeding by my ingeprent is, te ondersoek. Die vier eienskappe van die sprokie word deur Kate Bernheimer in haar baanbrekende opstel Fairy tale is form, Form is fairy tale uitgelê as: ’n onbetrokke verteller, abstraksie, instinktiewe logika en genormaliseerde towerkuns. Na my mening is dié vier eienskappe ook op die Bizarro-genre van toepassing. Hierdie oorvleuling is sigbaar in Bernheimer se fiksie en ook onder andere Lucy Corin en Aimee Bender s'n – skrywers wat my werk beïnvloed het. , This thesis is presented in two parts: Afrikaans and English.
- Full Text:
- Date Issued: 2016
Gold nanoparticle–based colorimetric probes for dopamine detection
- Authors: Ngomane, Nokuthula
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4565 , http://hdl.handle.net/10962/d1021261
- Description: Colorimetric probes have become important tools in analysis and biomedical technology. This thesis reports on the development of such probes for the detection of dopamine (DA). Liquid and different solid state probes were developed utilizing un–functionalized gold nanoparticles (UF–AuNPs). The liquid state probe is based on the growth and aggregation of the UF–AuNPs in the presence of DA. Upon addition of the UF–AuNPs to various concentrations of DA, the shape, size and colour change results in spectral shifts from lower to higher wavelengths. The analyte can be easily monitored by the naked eye from 5.0 nM DA with a calculated limit of detection of 2.5 nM (3σ) under optimal pH. Ascorbic acid (AA) has a potential to interfere with DA detection in solution since it is often present in biological fluids, but in this case the interference was limited to solutions where its concentration was beyond 200 times greater than that of DA. Since most of the previously reported colorimetric probes, especially those for DA are solution based, the main focus of the thesis was in the development of a solid state based colorimetric probe in the form of nanofibre mats. To overcome the interference challenges experienced in the solution studies (the interference by high concentrations of AA), the suitability of molecularly imprinted polymers (MIPs) for the selective detection of DA was investigated. The results showed that the MIPs produced did not play a significant role in enhancing the selectivity towards DA. A probe composed of just the UF–AuNPs and Nylon–6 (UF–AuNPs + N6) was also developed. The UF–AuNPs were synthesized following an in situ reduction method. The probe was only selective to DA and insensitive to other catecholamines at physiological pH. Thus, the probe did not require any addition functionalities to achieve selectivity and sensitive to DA. The liquid state probe and the composite UF–AuNPs + N6 nanofibre probe were successfully applied to a whole blood sample and showed good selectivity towards DA. The simple, sensitive and selective probe could be an excellent alternative for on–site and immediate detection of DA without the use of instrumentation. For quantification of DA using the solid state probe, open–source software imageJ was used to assist in the analysis of the nanofibre colours. It was observed that the intensity of the colour increased with the increase in concentration of DA in a linear fashion. The use of imageJ can also be a great alternative where the colour changes are not so clear or for visually impaired people. The solid state probe developed can detect DA qualitatively and quantitatively. The work also forms a good foundation for development of such probes for other analyte.
- Full Text:
- Date Issued: 2016
- Authors: Ngomane, Nokuthula
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4565 , http://hdl.handle.net/10962/d1021261
- Description: Colorimetric probes have become important tools in analysis and biomedical technology. This thesis reports on the development of such probes for the detection of dopamine (DA). Liquid and different solid state probes were developed utilizing un–functionalized gold nanoparticles (UF–AuNPs). The liquid state probe is based on the growth and aggregation of the UF–AuNPs in the presence of DA. Upon addition of the UF–AuNPs to various concentrations of DA, the shape, size and colour change results in spectral shifts from lower to higher wavelengths. The analyte can be easily monitored by the naked eye from 5.0 nM DA with a calculated limit of detection of 2.5 nM (3σ) under optimal pH. Ascorbic acid (AA) has a potential to interfere with DA detection in solution since it is often present in biological fluids, but in this case the interference was limited to solutions where its concentration was beyond 200 times greater than that of DA. Since most of the previously reported colorimetric probes, especially those for DA are solution based, the main focus of the thesis was in the development of a solid state based colorimetric probe in the form of nanofibre mats. To overcome the interference challenges experienced in the solution studies (the interference by high concentrations of AA), the suitability of molecularly imprinted polymers (MIPs) for the selective detection of DA was investigated. The results showed that the MIPs produced did not play a significant role in enhancing the selectivity towards DA. A probe composed of just the UF–AuNPs and Nylon–6 (UF–AuNPs + N6) was also developed. The UF–AuNPs were synthesized following an in situ reduction method. The probe was only selective to DA and insensitive to other catecholamines at physiological pH. Thus, the probe did not require any addition functionalities to achieve selectivity and sensitive to DA. The liquid state probe and the composite UF–AuNPs + N6 nanofibre probe were successfully applied to a whole blood sample and showed good selectivity towards DA. The simple, sensitive and selective probe could be an excellent alternative for on–site and immediate detection of DA without the use of instrumentation. For quantification of DA using the solid state probe, open–source software imageJ was used to assist in the analysis of the nanofibre colours. It was observed that the intensity of the colour increased with the increase in concentration of DA in a linear fashion. The use of imageJ can also be a great alternative where the colour changes are not so clear or for visually impaired people. The solid state probe developed can detect DA qualitatively and quantitatively. The work also forms a good foundation for development of such probes for other analyte.
- Full Text:
- Date Issued: 2016
Good governance as a key to effective and efficient service delivery in South Africa : a case of Buffalo City Metropolitan Municipality
- Authors: Mutangabende, Shepherd
- Date: 2016
- Subjects: Municipal government -- South Africa -- Eastern Cape Municipal government -- South Africa -- Eastern Cape Municipal government -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: http://hdl.handle.net/10353/7815 , vital:30720
- Description: In South Africa service delivery has become an everyday song as citizens are gradually questioning for a workable way out of their daily problems stimulated by the unsolved challenges of shortage of clean drinkable water, electricity, poor health facilities and poverty, housing, hunger and refuse removal among other things. All these problems are attributed to lack of accountability, transparency and participation in the manner public institutions and officials are operating. Thus, one can argue that good governance in the public sector is a key to improve service delivery because these protests “reflect very little opportunity for community participation and poor governance”. This in turn means, the crisis in service delivery is a crisis in transparency, participation and accountability because these three are narrowly inter-related as participation and transparency are a precondition for real accountability. The primary focus of this study is on accountability which is the outcome of a combination of transparency and public participation. The prevailing characteristics of governance in BCMM lack robust public participation and transparent which collaborates and empowers citizens by involving them in all the processes as indicated by missing links. The inescapable conclusion is that if good governance is to be achieved in BCMM according to its vision, public participation in service delivery, implementation, monitoring, evaluation in a transparent way and accountability has to be done like in the case of Brazil and India who have both found formidable ways of fostering accountability and improved service delivery. This study used a descriptive research design and a mixed methods approach.
- Full Text:
- Date Issued: 2016
- Authors: Mutangabende, Shepherd
- Date: 2016
- Subjects: Municipal government -- South Africa -- Eastern Cape Municipal government -- South Africa -- Eastern Cape Municipal government -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: http://hdl.handle.net/10353/7815 , vital:30720
- Description: In South Africa service delivery has become an everyday song as citizens are gradually questioning for a workable way out of their daily problems stimulated by the unsolved challenges of shortage of clean drinkable water, electricity, poor health facilities and poverty, housing, hunger and refuse removal among other things. All these problems are attributed to lack of accountability, transparency and participation in the manner public institutions and officials are operating. Thus, one can argue that good governance in the public sector is a key to improve service delivery because these protests “reflect very little opportunity for community participation and poor governance”. This in turn means, the crisis in service delivery is a crisis in transparency, participation and accountability because these three are narrowly inter-related as participation and transparency are a precondition for real accountability. The primary focus of this study is on accountability which is the outcome of a combination of transparency and public participation. The prevailing characteristics of governance in BCMM lack robust public participation and transparent which collaborates and empowers citizens by involving them in all the processes as indicated by missing links. The inescapable conclusion is that if good governance is to be achieved in BCMM according to its vision, public participation in service delivery, implementation, monitoring, evaluation in a transparent way and accountability has to be done like in the case of Brazil and India who have both found formidable ways of fostering accountability and improved service delivery. This study used a descriptive research design and a mixed methods approach.
- Full Text:
- Date Issued: 2016
Good governance as a mechanism to optimise development in Chris Hani District Municipality
- Mbunge, Sibongiseni Patronella
- Authors: Mbunge, Sibongiseni Patronella
- Date: 2016
- Subjects: Heritage tourism -- South Africa -- Eastern Cape Tourism -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/11752 , vital:26965
- Description: Good governance is the most important factor in exterminating poverty and stimulating development. South African heritage has the potential to contribute significantly towards the country’s economic development. Cultural Villages were introduced in the South African tourism industry as a contribution to the objective of rural development in order to improve African curio shops and township experiences and to advance diversification. This study was undertaken to investigate Good Governance Principle that can be employed in the Chris Hani District Municipality (CHDM) to enhance optimise development brought about by the Cultural Villages (CV) in the area. The study is qualitative in nature. The literature reviewed in this study shows that there is a general poor implementation of good governance principles in the governance and management of the cultural villages. The researcher attempted to achieve high validity and reliability by ensuring that the views and arguments advanced by respondents are accurate in that the chosen respondents consisted of operational workers within the municipality and members of the community. The study establishes that there are several challenges that hinder the effective implementation of good governance principles in the local and district municipalities. Other findings of the study include that there is a challenge of poor management of the CVs, lack of public participation and inadequate funding for the CVs. The main finding of the study is that, although good governance plays a significant role in the improvement of development, it has not contributed to the improvement of the development of the CHDM communities. The main recommendation based on this finding is that there should be regular and thorough public participation within the local municipalities about all the developments relating to the cultural villages. Additional recommendations include, inter alia, strong partnerships between the municipality and the communities and accountability.
- Full Text:
- Date Issued: 2016
- Authors: Mbunge, Sibongiseni Patronella
- Date: 2016
- Subjects: Heritage tourism -- South Africa -- Eastern Cape Tourism -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/11752 , vital:26965
- Description: Good governance is the most important factor in exterminating poverty and stimulating development. South African heritage has the potential to contribute significantly towards the country’s economic development. Cultural Villages were introduced in the South African tourism industry as a contribution to the objective of rural development in order to improve African curio shops and township experiences and to advance diversification. This study was undertaken to investigate Good Governance Principle that can be employed in the Chris Hani District Municipality (CHDM) to enhance optimise development brought about by the Cultural Villages (CV) in the area. The study is qualitative in nature. The literature reviewed in this study shows that there is a general poor implementation of good governance principles in the governance and management of the cultural villages. The researcher attempted to achieve high validity and reliability by ensuring that the views and arguments advanced by respondents are accurate in that the chosen respondents consisted of operational workers within the municipality and members of the community. The study establishes that there are several challenges that hinder the effective implementation of good governance principles in the local and district municipalities. Other findings of the study include that there is a challenge of poor management of the CVs, lack of public participation and inadequate funding for the CVs. The main finding of the study is that, although good governance plays a significant role in the improvement of development, it has not contributed to the improvement of the development of the CHDM communities. The main recommendation based on this finding is that there should be regular and thorough public participation within the local municipalities about all the developments relating to the cultural villages. Additional recommendations include, inter alia, strong partnerships between the municipality and the communities and accountability.
- Full Text:
- Date Issued: 2016
Government policies aimed at combating land degradation in Alfred Nzo District
- Authors: Nqaphi, David Zibekile
- Date: 2016
- Subjects: Land degradation -- South Africa Land reform -- Law and legislation -- South Africa Land use -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/12404 , vital:27063
- Description: Land degradation is a serious problem in communal district of Alfred Nzo, Eastern Cape in South Africa. The root causes of land degradation and soil erosion differ. The causes of land degradation in Alfred Nzo district communal areas are due to soil erosion by wind, water and poor agricultural practices. Rainfall is one of the most important climatic factor that contributed a lot in land degradation in the Alfred Nzo District. Other main factors contributing to land degradation include: Socio-economic factors related to historical land policies and inappropriate land uses, Poor land use planning, Drought and rainfall variability .Land use and management and sand mining. This study tried to pay more focus on the assessment of government policies which aimed at combating land degradation in South Africa in their nature but the area of focus will be Ntabankulu Local Municipality area in the project called Ematolweni Agricultural Co-operative Project. The reason to focus in this project is because they are currently practising crop production under electrified irrigation system but the main obstacle in this project are the dongas which are seemed to be a serious threat to the project site. During rainy seasons the project site is not easily accessible, that hampers access to market. There is also direct and serious effect of land degradation which is food insecurity which is emanating from loss of biodiversity and ground cover, loss of soil productivity, loss of income, decreased yield, and decline in economic productivity and national development. Lastly it is wisely recommended that to reduce the effect of land degradation in Alfred Nzo enlarge, government should strengthen the intervention programmes and provide more support to the LandCare programme which was the concept introduced in Australian and adopted in South Africa in 2001. This programme is assisting at restoring sustainability and productivity to land and water management in both rural and urban areas. It is holistic in nature, encompassing integrated sustainable natural resource management.
- Full Text:
- Date Issued: 2016
- Authors: Nqaphi, David Zibekile
- Date: 2016
- Subjects: Land degradation -- South Africa Land reform -- Law and legislation -- South Africa Land use -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/12404 , vital:27063
- Description: Land degradation is a serious problem in communal district of Alfred Nzo, Eastern Cape in South Africa. The root causes of land degradation and soil erosion differ. The causes of land degradation in Alfred Nzo district communal areas are due to soil erosion by wind, water and poor agricultural practices. Rainfall is one of the most important climatic factor that contributed a lot in land degradation in the Alfred Nzo District. Other main factors contributing to land degradation include: Socio-economic factors related to historical land policies and inappropriate land uses, Poor land use planning, Drought and rainfall variability .Land use and management and sand mining. This study tried to pay more focus on the assessment of government policies which aimed at combating land degradation in South Africa in their nature but the area of focus will be Ntabankulu Local Municipality area in the project called Ematolweni Agricultural Co-operative Project. The reason to focus in this project is because they are currently practising crop production under electrified irrigation system but the main obstacle in this project are the dongas which are seemed to be a serious threat to the project site. During rainy seasons the project site is not easily accessible, that hampers access to market. There is also direct and serious effect of land degradation which is food insecurity which is emanating from loss of biodiversity and ground cover, loss of soil productivity, loss of income, decreased yield, and decline in economic productivity and national development. Lastly it is wisely recommended that to reduce the effect of land degradation in Alfred Nzo enlarge, government should strengthen the intervention programmes and provide more support to the LandCare programme which was the concept introduced in Australian and adopted in South Africa in 2001. This programme is assisting at restoring sustainability and productivity to land and water management in both rural and urban areas. It is holistic in nature, encompassing integrated sustainable natural resource management.
- Full Text:
- Date Issued: 2016
GPU Accelerated protocol analysis for large and long-term traffic traces
- Nottingham, Alastair Timothy
- Authors: Nottingham, Alastair Timothy
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/910 , vital:20002
- Description: This thesis describes the design and implementation of GPF+, a complete general packet classification system developed using Nvidia CUDA for Compute Capability 3.5+ GPUs. This system was developed with the aim of accelerating the analysis of arbitrary network protocols within network traffic traces using inexpensive, massively parallel commodity hardware. GPF+ and its supporting components are specifically intended to support the processing of large, long-term network packet traces such as those produced by network telescopes, which are currently difficult and time consuming to analyse. The GPF+ classifier is based on prior research in the field, which produced a prototype classifier called GPF, targeted at Compute Capability 1.3 GPUs. GPF+ greatly extends the GPF model, improving runtime flexibility and scalability, whilst maintaining high execution efficiency. GPF+ incorporates a compact, lightweight registerbased state machine that supports massively-parallel, multi-match filter predicate evaluation, as well as efficient arbitrary field extraction. GPF+ tracks packet composition during execution, and adjusts processing at runtime to avoid redundant memory transactions and unnecessary computation through warp-voting. GPF+ additionally incorporates a 128-bit in-thread cache, accelerated through register shuffling, to accelerate access to packet data in slow GPU global memory. GPF+ uses a high-level DSL to simplify protocol and filter creation, whilst better facilitating protocol reuse. The system is supported by a pipeline of multi-threaded high-performance host components, which communicate asynchronously through 0MQ messaging middleware to buffer, index, and dispatch packet data on the host system. The system was evaluated using high-end Kepler (Nvidia GTX Titan) and entry level Maxwell (Nvidia GTX 750) GPUs. The results of this evaluation showed high system performance, limited only by device side IO (600MBps) in all tests. GPF+ maintained high occupancy and device utilisation in all tests, without significant serialisation, and showed improved scaling to more complex filter sets. Results were used to visualise captures of up to 160 GB in seconds, and to extract and pre-filter captures small enough to be easily analysed in applications such as Wireshark.
- Full Text:
- Date Issued: 2016
- Authors: Nottingham, Alastair Timothy
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/910 , vital:20002
- Description: This thesis describes the design and implementation of GPF+, a complete general packet classification system developed using Nvidia CUDA for Compute Capability 3.5+ GPUs. This system was developed with the aim of accelerating the analysis of arbitrary network protocols within network traffic traces using inexpensive, massively parallel commodity hardware. GPF+ and its supporting components are specifically intended to support the processing of large, long-term network packet traces such as those produced by network telescopes, which are currently difficult and time consuming to analyse. The GPF+ classifier is based on prior research in the field, which produced a prototype classifier called GPF, targeted at Compute Capability 1.3 GPUs. GPF+ greatly extends the GPF model, improving runtime flexibility and scalability, whilst maintaining high execution efficiency. GPF+ incorporates a compact, lightweight registerbased state machine that supports massively-parallel, multi-match filter predicate evaluation, as well as efficient arbitrary field extraction. GPF+ tracks packet composition during execution, and adjusts processing at runtime to avoid redundant memory transactions and unnecessary computation through warp-voting. GPF+ additionally incorporates a 128-bit in-thread cache, accelerated through register shuffling, to accelerate access to packet data in slow GPU global memory. GPF+ uses a high-level DSL to simplify protocol and filter creation, whilst better facilitating protocol reuse. The system is supported by a pipeline of multi-threaded high-performance host components, which communicate asynchronously through 0MQ messaging middleware to buffer, index, and dispatch packet data on the host system. The system was evaluated using high-end Kepler (Nvidia GTX Titan) and entry level Maxwell (Nvidia GTX 750) GPUs. The results of this evaluation showed high system performance, limited only by device side IO (600MBps) in all tests. GPF+ maintained high occupancy and device utilisation in all tests, without significant serialisation, and showed improved scaling to more complex filter sets. Results were used to visualise captures of up to 160 GB in seconds, and to extract and pre-filter captures small enough to be easily analysed in applications such as Wireshark.
- Full Text:
- Date Issued: 2016
Grace “The story of a wise cat and a cruel man.”
- Authors: Phepheng, Maruping
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:6005 , http://hdl.handle.net/10962/d1021213
- Description: Morgan, a widower and police detective, is quickly promoted from constable to captain after a series of successful criminal investigations, creating enemies in the process. One of the convicted and incarcerated is Paper, a gang leader with a violent upbringing. After a lucky release from prison, Paper, now Morgan’s fierce foe, plots to hurt him in the worst way possible – by killing his only son. The story is narrated by a cat named Grace, whose presence and companionship comes from another dimension and helps Morgan to keep sane.
- Full Text:
- Date Issued: 2016
- Authors: Phepheng, Maruping
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:6005 , http://hdl.handle.net/10962/d1021213
- Description: Morgan, a widower and police detective, is quickly promoted from constable to captain after a series of successful criminal investigations, creating enemies in the process. One of the convicted and incarcerated is Paper, a gang leader with a violent upbringing. After a lucky release from prison, Paper, now Morgan’s fierce foe, plots to hurt him in the worst way possible – by killing his only son. The story is narrated by a cat named Grace, whose presence and companionship comes from another dimension and helps Morgan to keep sane.
- Full Text:
- Date Issued: 2016
Grade 12 learners' perceptions of the effect of urban agriculture on life satisfaction in Duncan Village
- Authors: Beni, Ntombomzi Octavia
- Date: 2016
- Subjects: Urban agriculture -- South Africa -- Eastern Cape Agricultural education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/17861 , vital:41461
- Description: The importance of agricultural sciences in the school curriculum all over the world cannot be over-emphasized. It includes an alternative source of fresh produce, improved life satisfaction and a way to preserve cultural identity and traditions. This research study seeks to investigate the perception of Grade 12 learners on the effects of urban agriculture on life satisfaction in Duncan Village. The study adopts a descriptive survey design to elicit information from the respondents on their perceptions on the effects of urban agriculture on life satisfaction. A validated structured questionnaire whose reliability co-efficient is 0.81 was used to collect information. The simple random sampling technique was used to select 78 (seventy-eight) Grade 12 learners. The study reveals among others some components of life satisfaction as a result of urban agriculture. These components are; nutrition, self-employment, food security and poverty eradication and they have positive effects on life satisfaction of the respondents. The study recommends that the South Africa Government should make agriculture education as a compulsory subject for grade 10 and 11 learners in rural areas. This will enable them to develop entrepreneurial skills and self-reliance mentality before they finish their secondary school careers. Similarly, the practical components of this subject should constitute 50percent if not more from the overall marks. Realisation of this idea will alleviate, to some extent burden of unemployment and food scarcity as school leavers will be able to implement right away agricultural skills already acquired.
- Full Text:
- Date Issued: 2016
- Authors: Beni, Ntombomzi Octavia
- Date: 2016
- Subjects: Urban agriculture -- South Africa -- Eastern Cape Agricultural education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/17861 , vital:41461
- Description: The importance of agricultural sciences in the school curriculum all over the world cannot be over-emphasized. It includes an alternative source of fresh produce, improved life satisfaction and a way to preserve cultural identity and traditions. This research study seeks to investigate the perception of Grade 12 learners on the effects of urban agriculture on life satisfaction in Duncan Village. The study adopts a descriptive survey design to elicit information from the respondents on their perceptions on the effects of urban agriculture on life satisfaction. A validated structured questionnaire whose reliability co-efficient is 0.81 was used to collect information. The simple random sampling technique was used to select 78 (seventy-eight) Grade 12 learners. The study reveals among others some components of life satisfaction as a result of urban agriculture. These components are; nutrition, self-employment, food security and poverty eradication and they have positive effects on life satisfaction of the respondents. The study recommends that the South Africa Government should make agriculture education as a compulsory subject for grade 10 and 11 learners in rural areas. This will enable them to develop entrepreneurial skills and self-reliance mentality before they finish their secondary school careers. Similarly, the practical components of this subject should constitute 50percent if not more from the overall marks. Realisation of this idea will alleviate, to some extent burden of unemployment and food scarcity as school leavers will be able to implement right away agricultural skills already acquired.
- Full Text:
- Date Issued: 2016
Gradient high performance liquid chromatographic method for the simultaneous analysis of efavirenz, emtricitabine and tenofovir
- Authors: Koekemoer, Sonya Mariana
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/54679 , vital:26599
- Description: In 2014, approximately 6.8 million people in South Africa were HIV-positive, and the majority of those affected are aged 15 or older. A fixed-dose combination (FDC) antiretroviral (ARV) dosage form containing one non-nucleotide reverse transcriptase inhibitor (efavirenz) and two nucleotide reverse transcriptase inhibitors (emtricitabine and tenofovir) was licensed in South Africa in April 2013. New consolidated guidelines for HIV management and prevention of mother to child transmission (PMTCT) were published by the South African Department of Health in December 2014 and the FDC is now the recommended first-line treatment for HIV-positive patients. According to these guidelines all such people aged 15 and older, and weighing more than 40 kg, with a CD4 count of ≤ 500/ μl will be eligible for antiretroviral therapy (ART) using the FDC. In addition every pregnant and breastfeeding woman is eligible for lifelong ART regardless of CD4 count and EFV can be used as first-line treatment for pregnant women regardless of the length of gestation state of the pregnancy at that time. The use of this simplified regime is likely to promote much needed and improved adherence to therapy. An investigation into the development of a stability-indicating reversed-phase high performance liquid chromatography (RP-HPLC) method for the simultaneous quantitation of EFV, FTC and TNF was undertaken. Isocratic HPLC analysis was found to be unsuitable due to the highly polar FTC molecule eluting in the void. Therefore a gradient HPLC method was developed and validated. The method was validated according to the International Conference on Harmonisation, now known as International Council for Harmonization (ICH). Correlation coefficients > 0.999 were obtained for each assessment of linearity and FTC, TNF and EFV are linear in the range 0.4-40 μg/ml, 0.6-60 μg/ml and 1.2-120 μg/ml. The equation of the best-fit least squares regression lines for FTC, TNF and EFV were y = 0.0191x+0.0007, y = 0.0163x+0.0116 and y = 0.01x+0.016, respectively. The method is accurate as the y-intercept was < 2% of the detector response for all ARV, and the method is precise in terms of intra- and inter-assay precision as all % RSD < 2%. The stability-indicating nature of the method was demonstrated under acidic, alkaline and oxidative stress in addition to UV exposure and elevated temperatures, and the individual chromatograms were overlaid using Empower® 3 Software to establish whether there was interference with the peaks of interest. The forced degradation studies demonstrated the selectivity of the method for the ARV compounds. The method was applied to assay and in vitro dissolution studies of commercially available tablets. The amount of each active ingredient released from Atripla® was determined and compared to the amount of each drug released from Aspen Efavirenz® and Truvada® (a combination of FTC and TNF). The percent FTC released from Atripla® and Truvada® was similar based on the acceptance criteria for immediate-release BCS class 1 compounds. Statistical analysis was undertaken to compare the dissolution profiles of FTC, TNF and EFV. The percent of these compounds released in these studies indicate that bioequivalence testing would be required to declare these products interchangeable. The validated RP-HPLC and in vitro dissolution test method are suitable for routine quality control testing of solid oral dosage forms containing EFV, FTC and TNF, and as the dissolution method can discriminate between different formulations of the same molecule, these tools can also be used for analysis during formulation development studies. The method is not suitable for the analysis of the ARV plasma due to lack of sensitivity and an inability to quantitate the compounds at the required concentration levels. The use of HPLC with mass spectroscopy for quantitation would enhance the sensitivity of the method and may eliminate the quantitation of the molecules in the presence of interference that was observed when using UV detection. Fixed dose combination tablets are convenient for patient therapy and it is likely that in the future more molecules will be formulated into such dosage forms. However formulations such as these can pose significant difficulties when developing and using analytical methods for the quantitation of all compounds in the dosage form at the same time, in particular when the compounds have vastly different physico-chemical properties that impact the quality of a separation and therefore the analysis. Therefore when embarking on the development of FDC product cognisance of the difficulties of developing single methods for the analyses is required and approaches to overcome these difficulties should be considered.
- Full Text:
- Date Issued: 2016
- Authors: Koekemoer, Sonya Mariana
- Date: 2016
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/54679 , vital:26599
- Description: In 2014, approximately 6.8 million people in South Africa were HIV-positive, and the majority of those affected are aged 15 or older. A fixed-dose combination (FDC) antiretroviral (ARV) dosage form containing one non-nucleotide reverse transcriptase inhibitor (efavirenz) and two nucleotide reverse transcriptase inhibitors (emtricitabine and tenofovir) was licensed in South Africa in April 2013. New consolidated guidelines for HIV management and prevention of mother to child transmission (PMTCT) were published by the South African Department of Health in December 2014 and the FDC is now the recommended first-line treatment for HIV-positive patients. According to these guidelines all such people aged 15 and older, and weighing more than 40 kg, with a CD4 count of ≤ 500/ μl will be eligible for antiretroviral therapy (ART) using the FDC. In addition every pregnant and breastfeeding woman is eligible for lifelong ART regardless of CD4 count and EFV can be used as first-line treatment for pregnant women regardless of the length of gestation state of the pregnancy at that time. The use of this simplified regime is likely to promote much needed and improved adherence to therapy. An investigation into the development of a stability-indicating reversed-phase high performance liquid chromatography (RP-HPLC) method for the simultaneous quantitation of EFV, FTC and TNF was undertaken. Isocratic HPLC analysis was found to be unsuitable due to the highly polar FTC molecule eluting in the void. Therefore a gradient HPLC method was developed and validated. The method was validated according to the International Conference on Harmonisation, now known as International Council for Harmonization (ICH). Correlation coefficients > 0.999 were obtained for each assessment of linearity and FTC, TNF and EFV are linear in the range 0.4-40 μg/ml, 0.6-60 μg/ml and 1.2-120 μg/ml. The equation of the best-fit least squares regression lines for FTC, TNF and EFV were y = 0.0191x+0.0007, y = 0.0163x+0.0116 and y = 0.01x+0.016, respectively. The method is accurate as the y-intercept was < 2% of the detector response for all ARV, and the method is precise in terms of intra- and inter-assay precision as all % RSD < 2%. The stability-indicating nature of the method was demonstrated under acidic, alkaline and oxidative stress in addition to UV exposure and elevated temperatures, and the individual chromatograms were overlaid using Empower® 3 Software to establish whether there was interference with the peaks of interest. The forced degradation studies demonstrated the selectivity of the method for the ARV compounds. The method was applied to assay and in vitro dissolution studies of commercially available tablets. The amount of each active ingredient released from Atripla® was determined and compared to the amount of each drug released from Aspen Efavirenz® and Truvada® (a combination of FTC and TNF). The percent FTC released from Atripla® and Truvada® was similar based on the acceptance criteria for immediate-release BCS class 1 compounds. Statistical analysis was undertaken to compare the dissolution profiles of FTC, TNF and EFV. The percent of these compounds released in these studies indicate that bioequivalence testing would be required to declare these products interchangeable. The validated RP-HPLC and in vitro dissolution test method are suitable for routine quality control testing of solid oral dosage forms containing EFV, FTC and TNF, and as the dissolution method can discriminate between different formulations of the same molecule, these tools can also be used for analysis during formulation development studies. The method is not suitable for the analysis of the ARV plasma due to lack of sensitivity and an inability to quantitate the compounds at the required concentration levels. The use of HPLC with mass spectroscopy for quantitation would enhance the sensitivity of the method and may eliminate the quantitation of the molecules in the presence of interference that was observed when using UV detection. Fixed dose combination tablets are convenient for patient therapy and it is likely that in the future more molecules will be formulated into such dosage forms. However formulations such as these can pose significant difficulties when developing and using analytical methods for the quantitation of all compounds in the dosage form at the same time, in particular when the compounds have vastly different physico-chemical properties that impact the quality of a separation and therefore the analysis. Therefore when embarking on the development of FDC product cognisance of the difficulties of developing single methods for the analyses is required and approaches to overcome these difficulties should be considered.
- Full Text:
- Date Issued: 2016
Graduate job search activity in Zambia: a social capital analysis
- Authors: Nsenduluka, Mukupa
- Date: 2016
- Subjects: Social capital (Sociology) -- Zambia Unemployment -- Zambia , College graduates -- Employment -- Zambia
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/12917 , vital:27134
- Description: There is much to be said about the use of social capital in the job search patterns of graduates, however, little is researched on the use of social capital as a job search strategy. Despite the years of research that acknowledges the critical role social capital plays in determining job search outcomes, little to no research has been done to specifically understand the different ways in which graduates utilize their social capital (family, friends and acquaintances) to look for work. Human capital theory posits that education is the greatest determinant of employment in a labour market system that that awards educational credentials with occupational attainment. However, the reality is that a large number of Zambian graduates are jobless despite being educated. This study, therefore seeks to analyse the high levels of graduate unemployment from lternative theories of social capital and the job search. Knowing the different ways social capital expresses itself in graduate job search patterns provides possible solutions and a different perspective to addressing the high levels of graduate unemployment in Zambia. This study adopted a qualitative case study research design and made use of the snow ball sampling approach. Fifteen semistructured interviews were conducted and findings and emerging themes analysed in response to the central question, “how does social capital express itself in graduate job search patterns in Lusaka, Zambia?”. Through extensive thematic analyses, the researcher finds that there are eight ways in which graduates utilize their social capital to look for work and overcome challenges of the job search. This demonstrates that social capital can be a useful and beneficial job search strategy to adopt in a labour market system where educational credentials alone do not guarantee graduates successful job search outcomes.
- Full Text:
- Date Issued: 2016
- Authors: Nsenduluka, Mukupa
- Date: 2016
- Subjects: Social capital (Sociology) -- Zambia Unemployment -- Zambia , College graduates -- Employment -- Zambia
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/12917 , vital:27134
- Description: There is much to be said about the use of social capital in the job search patterns of graduates, however, little is researched on the use of social capital as a job search strategy. Despite the years of research that acknowledges the critical role social capital plays in determining job search outcomes, little to no research has been done to specifically understand the different ways in which graduates utilize their social capital (family, friends and acquaintances) to look for work. Human capital theory posits that education is the greatest determinant of employment in a labour market system that that awards educational credentials with occupational attainment. However, the reality is that a large number of Zambian graduates are jobless despite being educated. This study, therefore seeks to analyse the high levels of graduate unemployment from lternative theories of social capital and the job search. Knowing the different ways social capital expresses itself in graduate job search patterns provides possible solutions and a different perspective to addressing the high levels of graduate unemployment in Zambia. This study adopted a qualitative case study research design and made use of the snow ball sampling approach. Fifteen semistructured interviews were conducted and findings and emerging themes analysed in response to the central question, “how does social capital express itself in graduate job search patterns in Lusaka, Zambia?”. Through extensive thematic analyses, the researcher finds that there are eight ways in which graduates utilize their social capital to look for work and overcome challenges of the job search. This demonstrates that social capital can be a useful and beneficial job search strategy to adopt in a labour market system where educational credentials alone do not guarantee graduates successful job search outcomes.
- Full Text:
- Date Issued: 2016