Investigating the implementation of continuous assessment by grade 7 Social Studies teachers in the Oshana education region
- Authors: Matheus, Hilya
- Date: 2007
- Subjects: Educational tests and measurements -- Namibia Social sciences -- Study and teaching (Elementary) -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1593 , http://hdl.handle.net/10962/d1003475
- Description: Since independence in 1990, Namibia’s Ministry of Education Sport and Culture has focused on curriculum and assessment reforms. The introduction of Continuous Assessment (CA) for appraising learners’ achievement was considered to be a very important aspect of teaching and learning. This study focused on the implementation of CA in schools. The study explores how the selected grade 7 Social Studies teachers understand and implement CA. This study was conducted in the Oshana region of Namibia. Four grade 7 Social Studies teachers participated from two different schools. This study was done through a case study to gain insight into the implementation of CA in schools. Semi-structured interviews, observations and document analysis were the research methods used to collect the data. The findings indicate that these teachers have a theoretical understanding of what CA implies and what role it plays and are aware of assessment strategies. However these theoretical perspectives are not translated into practice. This implies a limited understanding of CA and reflects a gap between the teachers’ theoretical understanding of CA and its practical implementation. The study also identified various systemic factors that hamper the implementation of CA, which include overcrowded classrooms, increased teachers’ workload by CA, shortages of resources such as textbooks and lack of professional development. The nature of pre-service teacher education the participants went through, professional development programmes that are given to teachers as in-service training and a lack of guidelines in the syllabus on how to approach continuous assessment are clearly evident in the findings as factors that contribute to the teachers’ gap between theory and practice. The study concludes that even though a number of workshops on continuous assessment were conducted, the teachers still could not implement it as expected. The study findings inform my professional context as an Advisory Teacher and that of my colleagues. Therefore it made me realize what the teachers’ needs are and what kind of support they require.
- Full Text:
- Date Issued: 2007
- Authors: Matheus, Hilya
- Date: 2007
- Subjects: Educational tests and measurements -- Namibia Social sciences -- Study and teaching (Elementary) -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1593 , http://hdl.handle.net/10962/d1003475
- Description: Since independence in 1990, Namibia’s Ministry of Education Sport and Culture has focused on curriculum and assessment reforms. The introduction of Continuous Assessment (CA) for appraising learners’ achievement was considered to be a very important aspect of teaching and learning. This study focused on the implementation of CA in schools. The study explores how the selected grade 7 Social Studies teachers understand and implement CA. This study was conducted in the Oshana region of Namibia. Four grade 7 Social Studies teachers participated from two different schools. This study was done through a case study to gain insight into the implementation of CA in schools. Semi-structured interviews, observations and document analysis were the research methods used to collect the data. The findings indicate that these teachers have a theoretical understanding of what CA implies and what role it plays and are aware of assessment strategies. However these theoretical perspectives are not translated into practice. This implies a limited understanding of CA and reflects a gap between the teachers’ theoretical understanding of CA and its practical implementation. The study also identified various systemic factors that hamper the implementation of CA, which include overcrowded classrooms, increased teachers’ workload by CA, shortages of resources such as textbooks and lack of professional development. The nature of pre-service teacher education the participants went through, professional development programmes that are given to teachers as in-service training and a lack of guidelines in the syllabus on how to approach continuous assessment are clearly evident in the findings as factors that contribute to the teachers’ gap between theory and practice. The study concludes that even though a number of workshops on continuous assessment were conducted, the teachers still could not implement it as expected. The study findings inform my professional context as an Advisory Teacher and that of my colleagues. Therefore it made me realize what the teachers’ needs are and what kind of support they require.
- Full Text:
- Date Issued: 2007
Investigating the influences of validation on pharmaceutical manufacturing processes
- Authors: Muller, Damian Christian
- Date: 2007
- Subjects: Pharmaceutical industry -- Quality control , Pharmaceutical technology , Drugs -- Standards
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10412 , http://hdl.handle.net/10948/566 , Pharmaceutical industry -- Quality control , Pharmaceutical technology , Drugs -- Standards
- Description: This investigation attempts to examine the influences of validation on pharmaceutical processes especially at a new manufacturing facility that has to meet international requirements, and fulfil a cost effective business strategy. At Aspen Pharmacare, a pharmaceutical organisation, there are two manufacturing facilities situated adjacent to each other, one new and one old. The new facility creates ideal opportunities to supply products to local and international markets. The investigation compares legal requirements from local and international regulatory authorities. Validation and qualification practices as well as the problems encountered during the different phases are discussed. Particular attention is given to the validation approach at the new Aspen facility. Problems and proposed solutions relating to the design review, installation, operational, and performance qualification are discussed. Validation of analytical methods for cleaning analysis, cleaning validation of equipment, and optimisation of some tablet manufacturing processes are described. Statistical evaluations of analytical results are included to find the optimum conditions for integrating new personnel with new processes and equipment. A business model reviews the cost of non-conformances of the enalapril maleate 10 mg tablets manufactured at the two manufacturing facilities. Finally the dissertation proves that validation is not only a regulatory requirement but that it also provides benefits such as adding value to the business, and ultimately reducing the cost of medicines.
- Full Text:
- Date Issued: 2007
- Authors: Muller, Damian Christian
- Date: 2007
- Subjects: Pharmaceutical industry -- Quality control , Pharmaceutical technology , Drugs -- Standards
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10412 , http://hdl.handle.net/10948/566 , Pharmaceutical industry -- Quality control , Pharmaceutical technology , Drugs -- Standards
- Description: This investigation attempts to examine the influences of validation on pharmaceutical processes especially at a new manufacturing facility that has to meet international requirements, and fulfil a cost effective business strategy. At Aspen Pharmacare, a pharmaceutical organisation, there are two manufacturing facilities situated adjacent to each other, one new and one old. The new facility creates ideal opportunities to supply products to local and international markets. The investigation compares legal requirements from local and international regulatory authorities. Validation and qualification practices as well as the problems encountered during the different phases are discussed. Particular attention is given to the validation approach at the new Aspen facility. Problems and proposed solutions relating to the design review, installation, operational, and performance qualification are discussed. Validation of analytical methods for cleaning analysis, cleaning validation of equipment, and optimisation of some tablet manufacturing processes are described. Statistical evaluations of analytical results are included to find the optimum conditions for integrating new personnel with new processes and equipment. A business model reviews the cost of non-conformances of the enalapril maleate 10 mg tablets manufactured at the two manufacturing facilities. Finally the dissertation proves that validation is not only a regulatory requirement but that it also provides benefits such as adding value to the business, and ultimately reducing the cost of medicines.
- Full Text:
- Date Issued: 2007
Ionic liquids as media for electro-organic synthesis
- Authors: Kruger, Elna
- Date: 2007
- Subjects: Ionic solutions , Inorganic compounds -- Synthesis , Electrochemistry
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10413 , http://hdl.handle.net/10948/538 , Ionic solutions , Inorganic compounds -- Synthesis , Electrochemistry
- Description: The IL’s used in this study were either synthesized or commercially available. Preparation of the IL’s involved 2 step processes: firstly the heating of distilled 1-methylimidazole with distilled 1-chlorobutane under reflux to obtain 1-butyl-3- methylimidazolium chloride; secondly, the metathesis reaction of sodium tetrafluoroborate with 1-butyl-3-methylimidazolium chloride to obtain 1-butyl-3- methylimidazolium tetrafluoroborate. The addition of sodium tetrafluoroborate, sodium hexafluorophosphate and lithium trifluoromethane sulfonamide with 1-butyl-3-methylimidazolium chloride produced good yields of 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide respectively. The IL’s are hygroscopic and must be stored under a nitrogen atmosphere. The IL’s were analyzed using 1H and 13C NMR analysis with CDCl3 as solvent. The physical and chemical properties of these IL’s were compared to commercial products. The physical and chemical properties compared well to reference values from the literature. The physical properties measured include the density, conductivity and electrochemical window. The electrochemical window is dependant primarily on the resistance of the cation to reduction and the resistance of the anion to oxidation. The electrochemical windows of the IL’s were very similar to the reference windows obtained from literature and it can be seen that some IL’s have a slightly lower window which can be due to water present. Water content in the IL’s was determined with the use of a Karl Fischer titrator, with Hydranal 5 Composite as titrant and HPLC grade methanol as the base. The concentration of halide in the IL’s was determined with a Perkin-Elmer ICP-MS.
- Full Text:
- Date Issued: 2007
- Authors: Kruger, Elna
- Date: 2007
- Subjects: Ionic solutions , Inorganic compounds -- Synthesis , Electrochemistry
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10413 , http://hdl.handle.net/10948/538 , Ionic solutions , Inorganic compounds -- Synthesis , Electrochemistry
- Description: The IL’s used in this study were either synthesized or commercially available. Preparation of the IL’s involved 2 step processes: firstly the heating of distilled 1-methylimidazole with distilled 1-chlorobutane under reflux to obtain 1-butyl-3- methylimidazolium chloride; secondly, the metathesis reaction of sodium tetrafluoroborate with 1-butyl-3-methylimidazolium chloride to obtain 1-butyl-3- methylimidazolium tetrafluoroborate. The addition of sodium tetrafluoroborate, sodium hexafluorophosphate and lithium trifluoromethane sulfonamide with 1-butyl-3-methylimidazolium chloride produced good yields of 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide respectively. The IL’s are hygroscopic and must be stored under a nitrogen atmosphere. The IL’s were analyzed using 1H and 13C NMR analysis with CDCl3 as solvent. The physical and chemical properties of these IL’s were compared to commercial products. The physical and chemical properties compared well to reference values from the literature. The physical properties measured include the density, conductivity and electrochemical window. The electrochemical window is dependant primarily on the resistance of the cation to reduction and the resistance of the anion to oxidation. The electrochemical windows of the IL’s were very similar to the reference windows obtained from literature and it can be seen that some IL’s have a slightly lower window which can be due to water present. Water content in the IL’s was determined with the use of a Karl Fischer titrator, with Hydranal 5 Composite as titrant and HPLC grade methanol as the base. The concentration of halide in the IL’s was determined with a Perkin-Elmer ICP-MS.
- Full Text:
- Date Issued: 2007
Isolation and characterization of genes encoding heat shock protein 70s (hsp 70s) from two species of the coelacanth, Latimeria chalumnae and Latimeria menadoensis
- Modisakeng, Keoagile William
- Authors: Modisakeng, Keoagile William
- Date: 2007
- Subjects: Coelacanth Coelacanth -- Genetics Heat shock proteins Molecular chaperones Proteins -- Analysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3971 , http://hdl.handle.net/10962/d1004030
- Description: The extant coelacanths have a close resemblance to the coelacanth fossil records dating back to 230mya. Like their predecessors, the extant coelacanths inhabit rocky caves at a depth of 100-300m below sea level. In the Comoros, the water temperature at these depths is estimated to fluctuate between 14-20°C. High-level adaptation to these environment and lack of competition are thought to have led to the morphological uniformity and slow change throughout the history of the coelacanths. Under stress conditions, proteins unfold or misfold leading to the formation of aggregates. Molecular chaperones facilitate the correct folding of other proteins so that they can attain a stable tertiary structure. In addition, molecular chaperones aid the refolding of denatured proteins and the degradation of terminally misfolded protein after cellular stress. Heat shock proteins form one of the major classes of molecular chaperones. Here we show that, despite high-level adaptation to a unique habitat and slow change, the genome of the coelacanth encodes the major and highly conserved molecular chaperone, Hsp70. Latimeria menadoensis and Latimeria chalumnae contain intronless hsp70 genes encoding Hsp70 proteins archetypal of known Hsp70s. Based on the coelacanth codon usage, we have shown that bacterial protein expression systems, particularly Escherichia coli, may not be appropriate for the overproduction of coelacanth Hsp70s and coelacanth proteins in general. Also interesting, was the discovery that like the rat Hsc70, the L. menadoensis Hsp70 could not reverse thermal sensitivity in a temperate sensitive E. coli DnaK mutant strain, BB2362. We also report the successful isolation of a 1.2 kb region of L. menadoensis hsp70 upstream regulatory region. This region contain three putative heat shock elements, a TATA- box and two CAAT-boxes. This regulatory region resembled the Xenopus, mouse, and particularly tilapia hsp70 promoters, all of which have been shown to drive the expression of reporter genes in a heat dependent manner. Taken together, this data is the first to strongly suggest an inducible Hsp70-base cytoprotection mechanism in the coelacanth. It further provides basis to formulate testable predictions about the regulation, structure and function of Hsp70s in the living fossil, Latimeria.
- Full Text:
- Date Issued: 2007
- Authors: Modisakeng, Keoagile William
- Date: 2007
- Subjects: Coelacanth Coelacanth -- Genetics Heat shock proteins Molecular chaperones Proteins -- Analysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3971 , http://hdl.handle.net/10962/d1004030
- Description: The extant coelacanths have a close resemblance to the coelacanth fossil records dating back to 230mya. Like their predecessors, the extant coelacanths inhabit rocky caves at a depth of 100-300m below sea level. In the Comoros, the water temperature at these depths is estimated to fluctuate between 14-20°C. High-level adaptation to these environment and lack of competition are thought to have led to the morphological uniformity and slow change throughout the history of the coelacanths. Under stress conditions, proteins unfold or misfold leading to the formation of aggregates. Molecular chaperones facilitate the correct folding of other proteins so that they can attain a stable tertiary structure. In addition, molecular chaperones aid the refolding of denatured proteins and the degradation of terminally misfolded protein after cellular stress. Heat shock proteins form one of the major classes of molecular chaperones. Here we show that, despite high-level adaptation to a unique habitat and slow change, the genome of the coelacanth encodes the major and highly conserved molecular chaperone, Hsp70. Latimeria menadoensis and Latimeria chalumnae contain intronless hsp70 genes encoding Hsp70 proteins archetypal of known Hsp70s. Based on the coelacanth codon usage, we have shown that bacterial protein expression systems, particularly Escherichia coli, may not be appropriate for the overproduction of coelacanth Hsp70s and coelacanth proteins in general. Also interesting, was the discovery that like the rat Hsc70, the L. menadoensis Hsp70 could not reverse thermal sensitivity in a temperate sensitive E. coli DnaK mutant strain, BB2362. We also report the successful isolation of a 1.2 kb region of L. menadoensis hsp70 upstream regulatory region. This region contain three putative heat shock elements, a TATA- box and two CAAT-boxes. This regulatory region resembled the Xenopus, mouse, and particularly tilapia hsp70 promoters, all of which have been shown to drive the expression of reporter genes in a heat dependent manner. Taken together, this data is the first to strongly suggest an inducible Hsp70-base cytoprotection mechanism in the coelacanth. It further provides basis to formulate testable predictions about the regulation, structure and function of Hsp70s in the living fossil, Latimeria.
- Full Text:
- Date Issued: 2007
Isolation of a Clostridium Beijerinckii sLM01 cellulosome and the effect of sulphide on anaerobic digestion
- Authors: Mayende, Lungisa
- Date: 2007
- Subjects: Cellulose , Clostridium , Cellulase , Sulfides
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3973 , http://hdl.handle.net/10962/d1004032 , Cellulose , Clostridium , Cellulase , Sulfides
- Description: Cellulose is the most abundant and the most resistant and stable natural organic compound on earth. Enzyme hydrolysis is difficult because of its insolubility and heterogeneity. Some (anaerobic) microorganisms have overcome this by having a multienzyme system called the cellulosome. The aims of the study were to isolate a mesophilic Clostridium sp. from a biosulphidogenic bioreactor, to purify the cellulosome from this culture, to determine the cellulase and endoglucanase activities using Avicel and carboxymethylcellulose (CMC) as substrates and the dinitrosalicyclic (DNS) method. The organism was identified using 16S rDNA sequence analysis. The sequence obtained indicated that a strain of Clostridium beijerinckii was isolated. The cellulosome was purified from the putative C. beijerinckii sLM01 host culture using affinity chromatography purification and affinity digestion purification procedures. The cellulosomal and non-cellulosomal fractions of C. beijerinckii sLM01 were separated successfully, but the majority of the endoglucanase activity was lost during the Sepharose 4B chromatography step. These cellulosomal and non-cellulosomal fractions were characterised with regards to their pH and temperature optima and effector sensitivity. Increased additions of sulphide activated the cellulase activity of the cellulosomal and non-cellulosomal fractions up to 700 %, while increased additions of sulphate either increased the activity slightly or inhibited it dramatically, depending on the cellulosomal and non-cellulosomal fractions. Increased additions of cellobiose, glucose and acetate inhibited the cellulase and endoglucanase activities. pH optima of 5.0 and 7.5 were observed for cellulases and 5.0 for endoglucanases of the cellulosomal fraction. The noncellulosomal fraction exhibited a pH optimum of 7.5 for both cellulase and endoglucanase activities. Both fractions and enzymes exhibited a temperature optimum of 30 °C. The fundamental knowledge gained from the characterisation was applied to anaerobic digestion, where the effect of sulphide on the rate-limiting step was determined. Sulphide activated cellulase and endoglucanase activities and increased the % chemical oxygen demand (COD) removal rate. Levels of volatile fatty acids (VFAs) were higher in the bioreactor containing sulphide, substrate and C. beijerinckii. Sulphide therefore accelerated the rate-limiting step of anaerobic digestion.
- Full Text:
- Date Issued: 2007
- Authors: Mayende, Lungisa
- Date: 2007
- Subjects: Cellulose , Clostridium , Cellulase , Sulfides
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3973 , http://hdl.handle.net/10962/d1004032 , Cellulose , Clostridium , Cellulase , Sulfides
- Description: Cellulose is the most abundant and the most resistant and stable natural organic compound on earth. Enzyme hydrolysis is difficult because of its insolubility and heterogeneity. Some (anaerobic) microorganisms have overcome this by having a multienzyme system called the cellulosome. The aims of the study were to isolate a mesophilic Clostridium sp. from a biosulphidogenic bioreactor, to purify the cellulosome from this culture, to determine the cellulase and endoglucanase activities using Avicel and carboxymethylcellulose (CMC) as substrates and the dinitrosalicyclic (DNS) method. The organism was identified using 16S rDNA sequence analysis. The sequence obtained indicated that a strain of Clostridium beijerinckii was isolated. The cellulosome was purified from the putative C. beijerinckii sLM01 host culture using affinity chromatography purification and affinity digestion purification procedures. The cellulosomal and non-cellulosomal fractions of C. beijerinckii sLM01 were separated successfully, but the majority of the endoglucanase activity was lost during the Sepharose 4B chromatography step. These cellulosomal and non-cellulosomal fractions were characterised with regards to their pH and temperature optima and effector sensitivity. Increased additions of sulphide activated the cellulase activity of the cellulosomal and non-cellulosomal fractions up to 700 %, while increased additions of sulphate either increased the activity slightly or inhibited it dramatically, depending on the cellulosomal and non-cellulosomal fractions. Increased additions of cellobiose, glucose and acetate inhibited the cellulase and endoglucanase activities. pH optima of 5.0 and 7.5 were observed for cellulases and 5.0 for endoglucanases of the cellulosomal fraction. The noncellulosomal fraction exhibited a pH optimum of 7.5 for both cellulase and endoglucanase activities. Both fractions and enzymes exhibited a temperature optimum of 30 °C. The fundamental knowledge gained from the characterisation was applied to anaerobic digestion, where the effect of sulphide on the rate-limiting step was determined. Sulphide activated cellulase and endoglucanase activities and increased the % chemical oxygen demand (COD) removal rate. Levels of volatile fatty acids (VFAs) were higher in the bioreactor containing sulphide, substrate and C. beijerinckii. Sulphide therefore accelerated the rate-limiting step of anaerobic digestion.
- Full Text:
- Date Issued: 2007
Isolation of bioactive metabolites with activity against HIV-1 target proteins from extracts of Sutherlandia frutescens and Lobostemon trigonus
- Authors: Dambuza, Ntokozo Shirley
- Date: 2007
- Subjects: Medicinal plants -- Africa, Southern , HIV infections -- Alternative treatment -- Africa, Southern , Plant bioactive compounds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10335 , http://hdl.handle.net/10948/492 , http://hdl.handle.net/10948/d1012003 , Medicinal plants -- Africa, Southern , HIV infections -- Alternative treatment -- Africa, Southern , Plant bioactive compounds
- Description: Acquired Immunodeficiency Syndrome (AIDS) is a human disease caused by the human immunodeficiency virus type 1 (HIV-1) and it is one of the biggest social, economic and health challenges in the world. The Joint United Nations Programme on HIV/AIDS (UNAIDS) and World Health Organization (WHO) estimated that between 33.4 to 46.0 million people around the world were living with HIV/AIDS in December 2005 and the highest estimates are in the Sub-Saharan Africa (around 25 million). In more developed countries a combined antiretroviral therapy called highly active antiretroviral therapy (HAART) is used, which results in reduced progression to AIDS in most patients. Despite the beneficial effects of HAART, significant side effects are experienced by treated patients. In addition, most infected people live in countries where the treatment is very expensive or, in many cases, not available at all. These people therefore rely on medicinal plants for health care. In this study, aqueous extracts from Sutherlandia frutescens and Lobostemon trigonus were screened for potential anti-HIV activities in a series of in vitro enzymatic assays, including reverse transcriptase, HIV-1 protease and glycohydrolases. Two extracts of Sutherlandia leaves (SFL-1 and SFL-2) were prepared that inhibited HIV reverse transcriptase and a Lobostemon leaf extract (LTL) was shown to also inhibit this enzyme. All extracts were assayed at 1.25mg/ml. Tannin content was determined for all active extracts using a tannic acid assay. SFL-1 and SFL-2 were found to contain about 6 percent and 7 percent tannins, respectively, and LTL contained 31% tannins by weight. Tannins were removed using polyamide columns and three fractions were collected for each. The extracts were also fractionated with Sephadex G-25, Amberlite IR 120 and Dowex 1-X8 as size exclusion, cation exchange and anion exchange, respectively. Extracts were also fractionated by preparative thin layer chromatography where two compounds were separated from S. frutescens extract with high activity against reverse transcriptase while showing insignificant inhibition towards other enzymes tested. SFL-BFW-10 and SFL-WEF-7 inhibited reverse transcriptase by almost 100 percent and the IC50 values calculated for these compounds were 0.34 and 0.23mg/ml, respectively. Cytotoxicity of these compounds was evaluated on Chang liver cells and peripheral blood mononuclear cells (PBMCs). None of these compounds showed any significant inhibition of cell proliferation. The purity of these compounds could not be confirmed because there was insufficient material to use in the techniques required to show purity and identification. Therefore, TLC was used to determine the nature of these compounds. SFL-BFW-10 was identified as an organic acid and SFL-WEF-7 was identified as flavonoid.
- Full Text:
- Date Issued: 2007
- Authors: Dambuza, Ntokozo Shirley
- Date: 2007
- Subjects: Medicinal plants -- Africa, Southern , HIV infections -- Alternative treatment -- Africa, Southern , Plant bioactive compounds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10335 , http://hdl.handle.net/10948/492 , http://hdl.handle.net/10948/d1012003 , Medicinal plants -- Africa, Southern , HIV infections -- Alternative treatment -- Africa, Southern , Plant bioactive compounds
- Description: Acquired Immunodeficiency Syndrome (AIDS) is a human disease caused by the human immunodeficiency virus type 1 (HIV-1) and it is one of the biggest social, economic and health challenges in the world. The Joint United Nations Programme on HIV/AIDS (UNAIDS) and World Health Organization (WHO) estimated that between 33.4 to 46.0 million people around the world were living with HIV/AIDS in December 2005 and the highest estimates are in the Sub-Saharan Africa (around 25 million). In more developed countries a combined antiretroviral therapy called highly active antiretroviral therapy (HAART) is used, which results in reduced progression to AIDS in most patients. Despite the beneficial effects of HAART, significant side effects are experienced by treated patients. In addition, most infected people live in countries where the treatment is very expensive or, in many cases, not available at all. These people therefore rely on medicinal plants for health care. In this study, aqueous extracts from Sutherlandia frutescens and Lobostemon trigonus were screened for potential anti-HIV activities in a series of in vitro enzymatic assays, including reverse transcriptase, HIV-1 protease and glycohydrolases. Two extracts of Sutherlandia leaves (SFL-1 and SFL-2) were prepared that inhibited HIV reverse transcriptase and a Lobostemon leaf extract (LTL) was shown to also inhibit this enzyme. All extracts were assayed at 1.25mg/ml. Tannin content was determined for all active extracts using a tannic acid assay. SFL-1 and SFL-2 were found to contain about 6 percent and 7 percent tannins, respectively, and LTL contained 31% tannins by weight. Tannins were removed using polyamide columns and three fractions were collected for each. The extracts were also fractionated with Sephadex G-25, Amberlite IR 120 and Dowex 1-X8 as size exclusion, cation exchange and anion exchange, respectively. Extracts were also fractionated by preparative thin layer chromatography where two compounds were separated from S. frutescens extract with high activity against reverse transcriptase while showing insignificant inhibition towards other enzymes tested. SFL-BFW-10 and SFL-WEF-7 inhibited reverse transcriptase by almost 100 percent and the IC50 values calculated for these compounds were 0.34 and 0.23mg/ml, respectively. Cytotoxicity of these compounds was evaluated on Chang liver cells and peripheral blood mononuclear cells (PBMCs). None of these compounds showed any significant inhibition of cell proliferation. The purity of these compounds could not be confirmed because there was insufficient material to use in the techniques required to show purity and identification. Therefore, TLC was used to determine the nature of these compounds. SFL-BFW-10 was identified as an organic acid and SFL-WEF-7 was identified as flavonoid.
- Full Text:
- Date Issued: 2007
Isolation, propagation and rapid molecular detection of the Kalahari truffle, a mycorrhizal fungus occurring in South Africa
- Authors: Adeleke, Rasheed Adegbola
- Date: 2007 , 2013-04-03
- Subjects: Truffles -- Kalahari Desert , Fungi -- Identification , Mycorrhizal fungi -- South Africa , Edible fungi -- South Africa , Mushroom culture -- South Africa , Fungi -- Cultures and culture media -- South Africa , Truffles -- South Africa , Truffles -- Lifecycles , Mycorrhizal fungi -- Lifecycles
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3889 , http://hdl.handle.net/10962/d1002951 , Truffles -- Kalahari Desert , Fungi -- Identification , Mycorrhizal fungi -- South Africa , Edible fungi -- South Africa , Mushroom culture -- South Africa , Fungi -- Cultures and culture media -- South Africa , Truffles -- South Africa , Truffles -- Lifecycles , Mycorrhizal fungi -- Lifecycles
- Description: Terfezia pfeilii is an edible mycorrhizal fungus that thrives in the Kalahari Desert of southern Africa. It is best known by desert dwellers for its flavour and as a source of nutrition. Although the genus Terfezia is generally regarded as being an ectomycorrhizal mycobiont, the exact mycorrhizal type formed by T. pfeilli and its' associated host plants remains uncertain. Discovery of the host plants for T. pfeilii would first be required in order to further investigate the life cycle and cultivation of this truffle. This study focussed on the isolation of mycelia from the ascocarp, optimising the growth conditions of the mycelial cultures, rapid molecular identification of T. pfeilii, investigation of potential helper bacteria and mycorrhizal synthesis experiments. T. pfeilii ascocarps were harvested from the Spitskop Nature Reserve in Upington, South Africa. Ascocarps were successfully identified using both morphological and molecular methods. Despite the delayed growth mostly caused by contaminating microorganisms, the isolation of T. pfeilii mycelia culture was successful. Molecular techniques were used to confirm the identity of the pure culture. Further studies were conducted on ways to improve the growth conditions of the mycelial culture on Fontana medium. An optimum temperature of 32°C, the addition of Bovine Serum Albumin as a nitrogen source and a pH of 7.5 significantly improved the growth of T. pfeilii in vitro. A rapid PeR-based molecular method was developed to speed up the identification of T. pfeilii. Specific primers that can exclusively amplify the ITS region of T. pfeilii were designed and used to identify both the ascocarps and the mycelial culture. The specificity of these primers was confirmed by their inability to amplify DNA from the isolates of contamining fungi obtained during the isolation process. Molecular comparison was made to confirm the reclassification of South African samples of T. pfeilii as Kalaharituber pfeilii as proposed by Ferdman et al.,(2005). However, in this study, the name T. pfeilii has been retained. A total of 17 bacterial isolates were obtained from the fruiting bodies of T. pfeaii and these were tested for stimulation of mycelial growth in vitro, indole production and phosphate solubilising capabilities. Bacterial isolates that showed potential to be Mycorrhization Helper Bacteria (MHB) were identified as Paenibacillus sp., Bacillus sp. and Rhizobium tropici. Selected plant seedlings were inoculated with T. pfeilii cultures or ascocarp slurry in order to re-establish the mycorrhizal association. After 8 months, light microscopy observations revealed an endomycorrhizal type association between Cynodon dactylon and T. pfeilii. This was confirmed with molecular analysis using specific T. pfeilii ITS primers. After 15 months, molecular methods confirmed Acacia erioloba as another host plant. These results have provided essential information paving the way for further investigation into the life cycle and biology of the Kalahari truffle. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 2007
- Authors: Adeleke, Rasheed Adegbola
- Date: 2007 , 2013-04-03
- Subjects: Truffles -- Kalahari Desert , Fungi -- Identification , Mycorrhizal fungi -- South Africa , Edible fungi -- South Africa , Mushroom culture -- South Africa , Fungi -- Cultures and culture media -- South Africa , Truffles -- South Africa , Truffles -- Lifecycles , Mycorrhizal fungi -- Lifecycles
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3889 , http://hdl.handle.net/10962/d1002951 , Truffles -- Kalahari Desert , Fungi -- Identification , Mycorrhizal fungi -- South Africa , Edible fungi -- South Africa , Mushroom culture -- South Africa , Fungi -- Cultures and culture media -- South Africa , Truffles -- South Africa , Truffles -- Lifecycles , Mycorrhizal fungi -- Lifecycles
- Description: Terfezia pfeilii is an edible mycorrhizal fungus that thrives in the Kalahari Desert of southern Africa. It is best known by desert dwellers for its flavour and as a source of nutrition. Although the genus Terfezia is generally regarded as being an ectomycorrhizal mycobiont, the exact mycorrhizal type formed by T. pfeilli and its' associated host plants remains uncertain. Discovery of the host plants for T. pfeilii would first be required in order to further investigate the life cycle and cultivation of this truffle. This study focussed on the isolation of mycelia from the ascocarp, optimising the growth conditions of the mycelial cultures, rapid molecular identification of T. pfeilii, investigation of potential helper bacteria and mycorrhizal synthesis experiments. T. pfeilii ascocarps were harvested from the Spitskop Nature Reserve in Upington, South Africa. Ascocarps were successfully identified using both morphological and molecular methods. Despite the delayed growth mostly caused by contaminating microorganisms, the isolation of T. pfeilii mycelia culture was successful. Molecular techniques were used to confirm the identity of the pure culture. Further studies were conducted on ways to improve the growth conditions of the mycelial culture on Fontana medium. An optimum temperature of 32°C, the addition of Bovine Serum Albumin as a nitrogen source and a pH of 7.5 significantly improved the growth of T. pfeilii in vitro. A rapid PeR-based molecular method was developed to speed up the identification of T. pfeilii. Specific primers that can exclusively amplify the ITS region of T. pfeilii were designed and used to identify both the ascocarps and the mycelial culture. The specificity of these primers was confirmed by their inability to amplify DNA from the isolates of contamining fungi obtained during the isolation process. Molecular comparison was made to confirm the reclassification of South African samples of T. pfeilii as Kalaharituber pfeilii as proposed by Ferdman et al.,(2005). However, in this study, the name T. pfeilii has been retained. A total of 17 bacterial isolates were obtained from the fruiting bodies of T. pfeaii and these were tested for stimulation of mycelial growth in vitro, indole production and phosphate solubilising capabilities. Bacterial isolates that showed potential to be Mycorrhization Helper Bacteria (MHB) were identified as Paenibacillus sp., Bacillus sp. and Rhizobium tropici. Selected plant seedlings were inoculated with T. pfeilii cultures or ascocarp slurry in order to re-establish the mycorrhizal association. After 8 months, light microscopy observations revealed an endomycorrhizal type association between Cynodon dactylon and T. pfeilii. This was confirmed with molecular analysis using specific T. pfeilii ITS primers. After 15 months, molecular methods confirmed Acacia erioloba as another host plant. These results have provided essential information paving the way for further investigation into the life cycle and biology of the Kalahari truffle. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 2007
Karen Horney : a psychobiographical study
- Authors: Green, Sarah-Jane
- Date: 2007
- Subjects: Horney, Karen, 1885-1952 Women psychologists Levinson, Daniel J., d.1994 Levinson, Daniel J., d.1994 -- The seasons of a woman's life
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3186 , http://hdl.handle.net/10962/d1008374
- Description: This psychobiography on the life of Karen Horney is an exploratory-descriptive study that aims to explore and describe Horney's life structure development according to Daniel Levinson's (1996) theory of adult development. The method of research uses a qualitative single-case research design that studies her life over her entire lifespan and highlights the individual characteristics of Horney in a holistic manner within her socio-historical context. A purposive sampling procedure was used to select Karen Horney as the subject of the research and only published data was analyzed in the research. Multiple sources of data are used to obtain the information in this research, including an autobiography and three biographies written by three different authors. This data is organized according to the temporal sequence of her lifespan and the developmental periods and time frame of Levinson's theory. Horney's life is described and explored to highlight those areas of her life that conform to the developmental theory and those aspects of her life that are not included in the theoretical constructs of Levinson 's theory. By exploring the significant relationships that Horney developed throughout her life with family, friends, work colleagues, community and religious affiliations, and the important issues in her development, this study verifies Levinson's theory by corroborating his conceptualisation of adult development as a process of sequential stages divided into four main eras of development, linked by three periods of transition. A shortcoming of Levinson's theory relates to his omission of self-esteem issues and religious concerns as relevant factors experienced during the era of pre-adulthood and spiritual concerns during the era of late adulthood.
- Full Text:
- Date Issued: 2007
- Authors: Green, Sarah-Jane
- Date: 2007
- Subjects: Horney, Karen, 1885-1952 Women psychologists Levinson, Daniel J., d.1994 Levinson, Daniel J., d.1994 -- The seasons of a woman's life
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3186 , http://hdl.handle.net/10962/d1008374
- Description: This psychobiography on the life of Karen Horney is an exploratory-descriptive study that aims to explore and describe Horney's life structure development according to Daniel Levinson's (1996) theory of adult development. The method of research uses a qualitative single-case research design that studies her life over her entire lifespan and highlights the individual characteristics of Horney in a holistic manner within her socio-historical context. A purposive sampling procedure was used to select Karen Horney as the subject of the research and only published data was analyzed in the research. Multiple sources of data are used to obtain the information in this research, including an autobiography and three biographies written by three different authors. This data is organized according to the temporal sequence of her lifespan and the developmental periods and time frame of Levinson's theory. Horney's life is described and explored to highlight those areas of her life that conform to the developmental theory and those aspects of her life that are not included in the theoretical constructs of Levinson 's theory. By exploring the significant relationships that Horney developed throughout her life with family, friends, work colleagues, community and religious affiliations, and the important issues in her development, this study verifies Levinson's theory by corroborating his conceptualisation of adult development as a process of sequential stages divided into four main eras of development, linked by three periods of transition. A shortcoming of Levinson's theory relates to his omission of self-esteem issues and religious concerns as relevant factors experienced during the era of pre-adulthood and spiritual concerns during the era of late adulthood.
- Full Text:
- Date Issued: 2007
Killing for the camera?: an investigation into the relationship between serial killers and the media
- Authors: Olivier, Erin Monique
- Date: 2007
- Subjects: Serial murderers -- Press coverage , Serial murders in mass media , Violence in mass media
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8411 , http://hdl.handle.net/10948/587 , http://hdl.handle.net/10948/d1011672 , Serial murderers -- Press coverage , Serial murders in mass media , Violence in mass media
- Description: This study focuses on the role of media portrayal and coverage in serial killing. The first objective of the study is to develop a conceptual structure that aids in the understanding of the cyclical relationship between media, serial killer, and audience. The media acts as a catalyst in this relationship, providing the stage on which serial killer and audience form a fatal relationship in which celebrity status forms the ultimate motivation. Media sensationalism of serial killing and the extreme glamorization in fictional representations has obviously negative consequences. In developing such a structure I hope to demonstrate that there is an alternative to the sensationalizing and glamorizing of serial killers in the media. This alternative will take the form education and a more documentary-style approach to films about serial murder. The study focuses mainly on developing a theoretical framework that emphasizes each of the three elements of the cyclical relationship mentioned above separately. The second chapter is devoted to the media and its role. The third chapter focuses on serial killers and the motivations involved. The fourth chapter deals with the audience attracted to serial killing as a source of identification. A number of thinkers’ work is used in coming to grips with this relationship, including both American and South African authors. The fifth and final chapter takes into consideration the moment of application by addressing the South African situation. I conclude by discussing the repercussions of media glamorization and possible documentary-style alternatives.
- Full Text:
- Date Issued: 2007
Killing for the camera?: an investigation into the relationship between serial killers and the media
- Authors: Olivier, Erin Monique
- Date: 2007
- Subjects: Serial murderers -- Press coverage , Serial murders in mass media , Violence in mass media
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8411 , http://hdl.handle.net/10948/587 , http://hdl.handle.net/10948/d1011672 , Serial murderers -- Press coverage , Serial murders in mass media , Violence in mass media
- Description: This study focuses on the role of media portrayal and coverage in serial killing. The first objective of the study is to develop a conceptual structure that aids in the understanding of the cyclical relationship between media, serial killer, and audience. The media acts as a catalyst in this relationship, providing the stage on which serial killer and audience form a fatal relationship in which celebrity status forms the ultimate motivation. Media sensationalism of serial killing and the extreme glamorization in fictional representations has obviously negative consequences. In developing such a structure I hope to demonstrate that there is an alternative to the sensationalizing and glamorizing of serial killers in the media. This alternative will take the form education and a more documentary-style approach to films about serial murder. The study focuses mainly on developing a theoretical framework that emphasizes each of the three elements of the cyclical relationship mentioned above separately. The second chapter is devoted to the media and its role. The third chapter focuses on serial killers and the motivations involved. The fourth chapter deals with the audience attracted to serial killing as a source of identification. A number of thinkers’ work is used in coming to grips with this relationship, including both American and South African authors. The fifth and final chapter takes into consideration the moment of application by addressing the South African situation. I conclude by discussing the repercussions of media glamorization and possible documentary-style alternatives.
- Full Text:
- Date Issued: 2007
Laboratory investigation of a load carriage task observed in forestry
- Authors: Furney, Sheena Elizabeth
- Date: 2007
- Subjects: Work -- Physiological aspects , Foresters -- Workload , Human engineering , Lifting and carrying
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5145 , http://hdl.handle.net/10962/d1008188 , Work -- Physiological aspects , Foresters -- Workload , Human engineering , Lifting and carrying
- Description: The objective of the present study was to investigate and compare the human responses to two load carriage tasks performed with three different load masses and on three different gradients. The task of carrying hydrogel in one hand was observed in a silviculture industry and crude physiological and perceptual responses were measured. This task was simulated in a laboratory setting together with a suggested intervention of backpack carriage. Eighteen conditions were established which consisted of the two modes of carriage and a combination of three load masses (9kg, 12kg and 15kg) and three gradients (5%, 10% and 15%). Twenty eight Rhodes University female students comprised the sample and the experimental procedures were conducted on a Quinton treadmill. Each participant was required to complete nine of the eighteen conditions which were each four minutes in duration. Postural changes were assessed using lateral and posterior digital images taken at the second and fourth minute and compression and shearing forces were estimated with the ErgolmagerTM Physiological responses (heart rate, ventilation and metabolic responses) were measured continuously with the Quark b² and perceptual responses ('central' and 'local' RPE) were measured every minute during the experimentation and body discomfort was rated at the completion of each condition. Overall responses revealed that hand carriage (146 bt.min⁻¹ , 25.09 mIO₂. kg-l.min⁻¹) was generally found to be more physiologically stressful than backpack carriage (130 bt.min⁻¹, 22.15 mIO₂.kg⁻¹ .min⁻¹) independent of load mass and gradient. Physiological responses were higher (113 bt.min-1 to 174 bt.min⁻¹ ) in responses to increasing gradient as opposed to increasing load mass (104 bt.min-1 to 153 bt.min⁻¹ ) for both backpack and hand carriage. Categorisation using the guidelines of Sanders and McCormick (1993) allowed for classification of conditions, with respect to physiological responses, into 'moderate', 'heavy' and 'very heavy' stress. For almost all of the physiological responses the majority of conditions which were classified as 'moderate' were backpack carriage conditions and the conditions classified as 'very heavy' were mostly hand carriage conditions. In terms of postural responses hand carriage resulted in more strain and greater compression and shearing forces on the spine. In terms of the compression forces increasing gradient had a greater affect on backpack carriage (681 N to 935 N) compared to hand carriage (570N to 793N). In contrast, increasing load mass had a larger affect on hand carriage postures and compression forces (751 N to 935N) in comparison to backpack carriage (723N to 780N). Shearing forces were found to be worse in hand carriage conditions overall. Although participants generally underrated perceived exertion in relation to cardiorespiratory responses, these perceptions revealed that backpack carriage, with a mean 'central' RPE of 12 compared to 11 for hand carriage, was somewhat preferred to hand carriage and that increasing gradient was perceived to be marginally more straining than increasing load mass.
- Full Text:
- Date Issued: 2007
- Authors: Furney, Sheena Elizabeth
- Date: 2007
- Subjects: Work -- Physiological aspects , Foresters -- Workload , Human engineering , Lifting and carrying
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5145 , http://hdl.handle.net/10962/d1008188 , Work -- Physiological aspects , Foresters -- Workload , Human engineering , Lifting and carrying
- Description: The objective of the present study was to investigate and compare the human responses to two load carriage tasks performed with three different load masses and on three different gradients. The task of carrying hydrogel in one hand was observed in a silviculture industry and crude physiological and perceptual responses were measured. This task was simulated in a laboratory setting together with a suggested intervention of backpack carriage. Eighteen conditions were established which consisted of the two modes of carriage and a combination of three load masses (9kg, 12kg and 15kg) and three gradients (5%, 10% and 15%). Twenty eight Rhodes University female students comprised the sample and the experimental procedures were conducted on a Quinton treadmill. Each participant was required to complete nine of the eighteen conditions which were each four minutes in duration. Postural changes were assessed using lateral and posterior digital images taken at the second and fourth minute and compression and shearing forces were estimated with the ErgolmagerTM Physiological responses (heart rate, ventilation and metabolic responses) were measured continuously with the Quark b² and perceptual responses ('central' and 'local' RPE) were measured every minute during the experimentation and body discomfort was rated at the completion of each condition. Overall responses revealed that hand carriage (146 bt.min⁻¹ , 25.09 mIO₂. kg-l.min⁻¹) was generally found to be more physiologically stressful than backpack carriage (130 bt.min⁻¹, 22.15 mIO₂.kg⁻¹ .min⁻¹) independent of load mass and gradient. Physiological responses were higher (113 bt.min-1 to 174 bt.min⁻¹ ) in responses to increasing gradient as opposed to increasing load mass (104 bt.min-1 to 153 bt.min⁻¹ ) for both backpack and hand carriage. Categorisation using the guidelines of Sanders and McCormick (1993) allowed for classification of conditions, with respect to physiological responses, into 'moderate', 'heavy' and 'very heavy' stress. For almost all of the physiological responses the majority of conditions which were classified as 'moderate' were backpack carriage conditions and the conditions classified as 'very heavy' were mostly hand carriage conditions. In terms of postural responses hand carriage resulted in more strain and greater compression and shearing forces on the spine. In terms of the compression forces increasing gradient had a greater affect on backpack carriage (681 N to 935 N) compared to hand carriage (570N to 793N). In contrast, increasing load mass had a larger affect on hand carriage postures and compression forces (751 N to 935N) in comparison to backpack carriage (723N to 780N). Shearing forces were found to be worse in hand carriage conditions overall. Although participants generally underrated perceived exertion in relation to cardiorespiratory responses, these perceptions revealed that backpack carriage, with a mean 'central' RPE of 12 compared to 11 for hand carriage, was somewhat preferred to hand carriage and that increasing gradient was perceived to be marginally more straining than increasing load mass.
- Full Text:
- Date Issued: 2007
Land reform policies and human rights : a South African case study
- Fabbriciani, Antonio Antonino
- Authors: Fabbriciani, Antonio Antonino
- Date: 2007
- Subjects: Land reform -- South Africa -- Case studies , Human rights -- South Africa -- Case studies
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:9042 , http://hdl.handle.net/10948/502 , Land reform -- South Africa -- Case studies , Human rights -- South Africa -- Case studies
- Description: This treatise begins with a discussion of different clauses of the Bill of Rights in the South African Constitution and the land reform policies of the South African government. The inequality and injustice caused by decades of apartheid land law forms the background of the land reform programme. The treatise addresses the consequences of this legacy on the implementation of the South African Constitution including the right to property. The discussion includes the three key elements of the land reform programme namely restitution, redistribution and tenure reform. The content of this treatise ranges over these three elements of land reform, applying constitutional issues to the relevant case law, The balancing and the reconciliation of rights and interest between the individual and the public in a just manner will be the barometer. The conclusion shows that the Constitution both protects existing rights and authorises the promotion of land reform within the framework of Section 25 of the Constitution, and that every aspect of the property clause has to be regarded as part of a constitional effort in balancing individual interest and public interest in terms of a constitutional order. It is my sincere hope that this treatise will contribute toward the achievement of equity, stability and by the values of an open and democratic society based on human dignity, freedom and human rights.
- Full Text:
- Date Issued: 2007
- Authors: Fabbriciani, Antonio Antonino
- Date: 2007
- Subjects: Land reform -- South Africa -- Case studies , Human rights -- South Africa -- Case studies
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:9042 , http://hdl.handle.net/10948/502 , Land reform -- South Africa -- Case studies , Human rights -- South Africa -- Case studies
- Description: This treatise begins with a discussion of different clauses of the Bill of Rights in the South African Constitution and the land reform policies of the South African government. The inequality and injustice caused by decades of apartheid land law forms the background of the land reform programme. The treatise addresses the consequences of this legacy on the implementation of the South African Constitution including the right to property. The discussion includes the three key elements of the land reform programme namely restitution, redistribution and tenure reform. The content of this treatise ranges over these three elements of land reform, applying constitutional issues to the relevant case law, The balancing and the reconciliation of rights and interest between the individual and the public in a just manner will be the barometer. The conclusion shows that the Constitution both protects existing rights and authorises the promotion of land reform within the framework of Section 25 of the Constitution, and that every aspect of the property clause has to be regarded as part of a constitional effort in balancing individual interest and public interest in terms of a constitutional order. It is my sincere hope that this treatise will contribute toward the achievement of equity, stability and by the values of an open and democratic society based on human dignity, freedom and human rights.
- Full Text:
- Date Issued: 2007
Limiting vulnerability exposure through effective patch management: threat mitigation through vulnerability remediation
- Authors: White, Dominic Stjohn Dolin
- Date: 2007 , 2007-02-08
- Subjects: Computer networks -- Security measures , Computer viruses , Computer security
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4629 , http://hdl.handle.net/10962/d1006510 , Computer networks -- Security measures , Computer viruses , Computer security
- Description: This document aims to provide a complete discussion on vulnerability and patch management. The first chapters look at the trends relating to vulnerabilities, exploits, attacks and patches. These trends describe the drivers of patch and vulnerability management and situate the discussion in the current security climate. The following chapters then aim to present both policy and technical solutions to the problem. The policies described lay out a comprehensive set of steps that can be followed by any organisation to implement their own patch management policy, including practical advice on integration with other policies, managing risk, identifying vulnerability, strategies for reducing downtime and generating metrics to measure progress. Having covered the steps that can be taken by users, a strategy describing how best a vendor should implement a related patch release policy is provided. An argument is made that current monthly patch release schedules are inadequate to allow users to most effectively and timeously mitigate vulnerabilities. The final chapters discuss the technical aspect of automating parts of the policies described. In particular the concept of 'defense in depth' is used to discuss additional strategies for 'buying time' during the patch process. The document then goes on to conclude that in the face of increasing malicious activity and more complex patching, solid frameworks such as those provided in this document are required to ensure an organisation can fully manage the patching process. However, more research is required to fully understand vulnerabilities and exploits. In particular more attention must be paid to threats, as little work as been done to fully understand threat-agent capabilities and activities from a day to day basis. , TeX output 2007.02.08:2212 , Adobe Acrobat 9.51 Paper Capture Plug-in
- Full Text:
- Date Issued: 2007
- Authors: White, Dominic Stjohn Dolin
- Date: 2007 , 2007-02-08
- Subjects: Computer networks -- Security measures , Computer viruses , Computer security
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4629 , http://hdl.handle.net/10962/d1006510 , Computer networks -- Security measures , Computer viruses , Computer security
- Description: This document aims to provide a complete discussion on vulnerability and patch management. The first chapters look at the trends relating to vulnerabilities, exploits, attacks and patches. These trends describe the drivers of patch and vulnerability management and situate the discussion in the current security climate. The following chapters then aim to present both policy and technical solutions to the problem. The policies described lay out a comprehensive set of steps that can be followed by any organisation to implement their own patch management policy, including practical advice on integration with other policies, managing risk, identifying vulnerability, strategies for reducing downtime and generating metrics to measure progress. Having covered the steps that can be taken by users, a strategy describing how best a vendor should implement a related patch release policy is provided. An argument is made that current monthly patch release schedules are inadequate to allow users to most effectively and timeously mitigate vulnerabilities. The final chapters discuss the technical aspect of automating parts of the policies described. In particular the concept of 'defense in depth' is used to discuss additional strategies for 'buying time' during the patch process. The document then goes on to conclude that in the face of increasing malicious activity and more complex patching, solid frameworks such as those provided in this document are required to ensure an organisation can fully manage the patching process. However, more research is required to fully understand vulnerabilities and exploits. In particular more attention must be paid to threats, as little work as been done to fully understand threat-agent capabilities and activities from a day to day basis. , TeX output 2007.02.08:2212 , Adobe Acrobat 9.51 Paper Capture Plug-in
- Full Text:
- Date Issued: 2007
Local food choices and nutrition : a case study of amarewu in the FET consumer studies curriculum
- Authors: Kota, Lutho Siyabulela
- Date: 2007
- Subjects: Continuing education -- South Africa -- Eastern Cape -- Curricula Education -- South Africa -- Eastern Cape -- Curricula Ethnoscience -- South Africa -- Eastern Cape Indigenous peoples -- Study and teaching -- South Africa -- Eastern Cape Nutrition -- Study and teaching -- South Africa--Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1666 , http://hdl.handle.net/10962/d1003549
- Description: This case study examines the introduction of Indigenous Knowledge (IK) in the Consumer Studies curriculum of Further Education and Training (FET). The research is centred on the use of enquiry methodologies involving learners observing parent demonstrations of the making of ‘amarewu’ and other activities centred on the propositional knowledge dealing with fermentation in the Consumer Studies curriculum. The research involved a review of curriculum documents, participant observation of a demonstration of local food practices related to ‘amarewu’ and learner research activities and interviews to review the developing learning interactions. The learning activities were focused on the learners’ researching the cultural and nutritional value of ‘amarewu’ and included an audit of food consumed in the community. What transpired from this study was that working with IK in the curriculum is possible. The inclusion of IK is not only possible but desirable and has exciting possibilities for relevance in contemporary education. The active involvement in parent demonstration engaged the learners in IK in their mother tongue, therefore indigenous knowledge has relevance. The curriculum concepts also enhanced the engagement by giving rise to more relevant knowledge and a respect for cultural matters. Intergenerational capital and subject concepts also enabled learners to engage with local nutritional problems and to come up with practical solutions. This study demonstrates how IK intergenerational capital in combination in combination with curriculum concepts (subject knowledge capital) can enhance relevance and the learners’ real engagement with local health and nutritional problems. Not only did the learners have culturally valued knowledge, but also knowledge that has a practical grasp of the problem and that they could use to engage relevant issues. These two views of knowledge join in learning and can be used to address health issues. I therefore recommend connection of cultural knowledge and conceptual knowledge to strengthen the revitalisation of cultural heritage, thus equalising it to the modern patterns of life and enhancing meaningful curriculum orientation.
- Full Text:
- Date Issued: 2007
- Authors: Kota, Lutho Siyabulela
- Date: 2007
- Subjects: Continuing education -- South Africa -- Eastern Cape -- Curricula Education -- South Africa -- Eastern Cape -- Curricula Ethnoscience -- South Africa -- Eastern Cape Indigenous peoples -- Study and teaching -- South Africa -- Eastern Cape Nutrition -- Study and teaching -- South Africa--Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1666 , http://hdl.handle.net/10962/d1003549
- Description: This case study examines the introduction of Indigenous Knowledge (IK) in the Consumer Studies curriculum of Further Education and Training (FET). The research is centred on the use of enquiry methodologies involving learners observing parent demonstrations of the making of ‘amarewu’ and other activities centred on the propositional knowledge dealing with fermentation in the Consumer Studies curriculum. The research involved a review of curriculum documents, participant observation of a demonstration of local food practices related to ‘amarewu’ and learner research activities and interviews to review the developing learning interactions. The learning activities were focused on the learners’ researching the cultural and nutritional value of ‘amarewu’ and included an audit of food consumed in the community. What transpired from this study was that working with IK in the curriculum is possible. The inclusion of IK is not only possible but desirable and has exciting possibilities for relevance in contemporary education. The active involvement in parent demonstration engaged the learners in IK in their mother tongue, therefore indigenous knowledge has relevance. The curriculum concepts also enhanced the engagement by giving rise to more relevant knowledge and a respect for cultural matters. Intergenerational capital and subject concepts also enabled learners to engage with local nutritional problems and to come up with practical solutions. This study demonstrates how IK intergenerational capital in combination in combination with curriculum concepts (subject knowledge capital) can enhance relevance and the learners’ real engagement with local health and nutritional problems. Not only did the learners have culturally valued knowledge, but also knowledge that has a practical grasp of the problem and that they could use to engage relevant issues. These two views of knowledge join in learning and can be used to address health issues. I therefore recommend connection of cultural knowledge and conceptual knowledge to strengthen the revitalisation of cultural heritage, thus equalising it to the modern patterns of life and enhancing meaningful curriculum orientation.
- Full Text:
- Date Issued: 2007
Localisation of Theiler's Murine Encephalomyelitis virus non-structural proteins 2B, 2C, 2BC and 3A in BHK-21 cells, and the effect of amino acid substitutions in 2C on localisation and virus replication
- Authors: Murray, Lindsay
- Date: 2007
- Subjects: Encephalomyelitis -- Genetic aspects , Amino acid sequence , Picornaviruses , Viruses -- Reproduction
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4090 , http://hdl.handle.net/10962/d1007722 , Encephalomyelitis -- Genetic aspects , Amino acid sequence , Picornaviruses , Viruses -- Reproduction
- Description: The picornavirus family includes significant human and animal viruses such as poliovirus (PV), human rhinovirus (HRV) and foot-and-mouth-disease virus (FMDV). Current disease treatment and control strategies are limited by an incomplete understanding of the interactions between the non-structural, replicative picornavirus proteins and host cell components. To investigate these interactions, Theiler's murine encephalomyelitis virus (TMEV) 2B, 2C, 2BC and 3A proteins were transiently expressed in BHK-21 cells and detected by indirect immunostaining and laser-scanning or epifluorescence microscopy. The signal of the 2B protein overlapped with that of the ER marker protein, ERp60, as well as that of the peripheral Golgi marker protein, β-COP. The 2C protein overlapped with ERp60 in a faint reticular stain, and localised to large punctate structures that partially overlapped with β-COP at higher levels of expression. The 2BC protein located to large perinuclear structures that overlapped exclusively with β-COP. The TMEV 3A protein signal overlapped with both ERp60 and β-COP stains, in addition in cells expressing the 3A protein the ER appeared swollen and bulbous while the Golgi was dispersed in some cells. 2C and 2BC proteins with C-terminal deletions localised in the same manner as the wild type proteins indicating that the localisation signals that determine subcellular localisation of the proteins are within the N-terminal 60 amino acids of the 2C protein. The significance of the high degree of conservation of the N-terminal domain of the 2C protein throughout the Picornaviridae was investigated through the introduction of amino acid substitution mutations at highly conserved residues in the N-terminal domain of 2C into the viral cDNA. Upon transfection of the viral RNA into BHK-21 cells, it was observed that substitution of amino acid residues 8, 18 and 29 abolished the ability of TMEV to induce cytopathic effect (CPE), while substitution of residues 4, 14 and 23 only attenuated the ability of TMEV to induce CPE. To determine whether amino acid substitution mutations would affect the localisation of the 2C protein, 2C proteins with substitution mutations at amino acids 4, 8, 14, 18, 23 and 29 were transiently expressed in BHK-21 cells and detected by indirect imrnunostaining and examination by laser-scanning confocal and epifluorescence microscopy. The 2C mutant 4, 8 and 29 proteins showed slightly altered localisation patterns compared to the wild type protein with a significant portion of the proteins localising in a perinuclear stain suggesting possible localisation to the nuclear envelop. The 2C mutant 14 and 18 proteins localised to a diffuse pattern in BHK-21 cells while the 2C mutant 23 protein located to small punctate structures that partially overlapped with the ERp60 stain but were completely separate from the β-COP stain. Finally, a hydrophilic, antigenic region of the 2C protein was expressed in frame with an N-terminal GST tag and was successfully purified on a pilot-scale and detected by Western analysis. This 2C178 peptide will be used to generate antibodies against the 2C and 2BC proteins for use in future studies. This study has furthered our knowledge of the localisation of the picornavirus 2B, 2C, 2BC and 3A proteins in host cells and identified a possible link between this localisation and an ability of TMEV to replicate in BHK-21 cells.
- Full Text:
- Date Issued: 2007
- Authors: Murray, Lindsay
- Date: 2007
- Subjects: Encephalomyelitis -- Genetic aspects , Amino acid sequence , Picornaviruses , Viruses -- Reproduction
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4090 , http://hdl.handle.net/10962/d1007722 , Encephalomyelitis -- Genetic aspects , Amino acid sequence , Picornaviruses , Viruses -- Reproduction
- Description: The picornavirus family includes significant human and animal viruses such as poliovirus (PV), human rhinovirus (HRV) and foot-and-mouth-disease virus (FMDV). Current disease treatment and control strategies are limited by an incomplete understanding of the interactions between the non-structural, replicative picornavirus proteins and host cell components. To investigate these interactions, Theiler's murine encephalomyelitis virus (TMEV) 2B, 2C, 2BC and 3A proteins were transiently expressed in BHK-21 cells and detected by indirect immunostaining and laser-scanning or epifluorescence microscopy. The signal of the 2B protein overlapped with that of the ER marker protein, ERp60, as well as that of the peripheral Golgi marker protein, β-COP. The 2C protein overlapped with ERp60 in a faint reticular stain, and localised to large punctate structures that partially overlapped with β-COP at higher levels of expression. The 2BC protein located to large perinuclear structures that overlapped exclusively with β-COP. The TMEV 3A protein signal overlapped with both ERp60 and β-COP stains, in addition in cells expressing the 3A protein the ER appeared swollen and bulbous while the Golgi was dispersed in some cells. 2C and 2BC proteins with C-terminal deletions localised in the same manner as the wild type proteins indicating that the localisation signals that determine subcellular localisation of the proteins are within the N-terminal 60 amino acids of the 2C protein. The significance of the high degree of conservation of the N-terminal domain of the 2C protein throughout the Picornaviridae was investigated through the introduction of amino acid substitution mutations at highly conserved residues in the N-terminal domain of 2C into the viral cDNA. Upon transfection of the viral RNA into BHK-21 cells, it was observed that substitution of amino acid residues 8, 18 and 29 abolished the ability of TMEV to induce cytopathic effect (CPE), while substitution of residues 4, 14 and 23 only attenuated the ability of TMEV to induce CPE. To determine whether amino acid substitution mutations would affect the localisation of the 2C protein, 2C proteins with substitution mutations at amino acids 4, 8, 14, 18, 23 and 29 were transiently expressed in BHK-21 cells and detected by indirect imrnunostaining and examination by laser-scanning confocal and epifluorescence microscopy. The 2C mutant 4, 8 and 29 proteins showed slightly altered localisation patterns compared to the wild type protein with a significant portion of the proteins localising in a perinuclear stain suggesting possible localisation to the nuclear envelop. The 2C mutant 14 and 18 proteins localised to a diffuse pattern in BHK-21 cells while the 2C mutant 23 protein located to small punctate structures that partially overlapped with the ERp60 stain but were completely separate from the β-COP stain. Finally, a hydrophilic, antigenic region of the 2C protein was expressed in frame with an N-terminal GST tag and was successfully purified on a pilot-scale and detected by Western analysis. This 2C178 peptide will be used to generate antibodies against the 2C and 2BC proteins for use in future studies. This study has furthered our knowledge of the localisation of the picornavirus 2B, 2C, 2BC and 3A proteins in host cells and identified a possible link between this localisation and an ability of TMEV to replicate in BHK-21 cells.
- Full Text:
- Date Issued: 2007
Making visual literacy meaningful in a rural context: an action research case study
- Authors: Mbelani, Madeyandile
- Date: 2007
- Subjects: Visual literacy -- Study and teaching (Secondary) -- South Africa -- Eastern Cape -- Case studies Education -- Research -- Case studies Education -- Research -- South Africa -- Eastern Cape Rural schools -- Research -- Case studies Rural schools -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1668 , http://hdl.handle.net/10962/d1003551
- Description: This thesis reports on a collaborative action research case study into the teaching of visual literacy to Grade 10 learners in a rural high school in the Eastern Cape, South Africa. Visual literacy is one of the critical aspects that have been incorporated in the teaching of English First Additional Language as required by the National Curriculum Statement (Grade 10-12), which has been implemented in Grade 10 as from 2006. With the aim of improving learners’ performance in visual literacy I designed a visual literacy unit that consisted of lesson plans running over 7 periods in 10 school days. In implementing the unit the learners were first grouped and then exposed to visual grammar and visual texts and then they critically viewed such texts and designed their own. Data was collected daily in the form of individual learner journals, researcher’s journal/diary, and copies were kept of activities done by learners (individually or in groups). Also, two teachers were invited as non-participant observers to each visit a lesson. Learner focus groups were conducted and critical friends were interviewed, tape recorded and transcribed. A camera was used to take still photographs to show learner activities in groups and during group presentations. The data revealed that visual literacy could be taught meaningfully in a rural high school as the learners could identify, cut, paste and discuss elements of visual language and they finally designed their own advertisements in groups. In the analysis of data the following factors emerged as hindrances for successful teaching of visual literacy in a rural high school: lack of resources; learners’ lack of a foundation in visual literacy from Grades 7-9; and problems revolving around time management and pacing. As action research comes in spirals, this research represented the first one and the researcher found the study an eye opener and a foundation to build on in the second spiral (that is not part of this research).
- Full Text:
- Date Issued: 2007
- Authors: Mbelani, Madeyandile
- Date: 2007
- Subjects: Visual literacy -- Study and teaching (Secondary) -- South Africa -- Eastern Cape -- Case studies Education -- Research -- Case studies Education -- Research -- South Africa -- Eastern Cape Rural schools -- Research -- Case studies Rural schools -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1668 , http://hdl.handle.net/10962/d1003551
- Description: This thesis reports on a collaborative action research case study into the teaching of visual literacy to Grade 10 learners in a rural high school in the Eastern Cape, South Africa. Visual literacy is one of the critical aspects that have been incorporated in the teaching of English First Additional Language as required by the National Curriculum Statement (Grade 10-12), which has been implemented in Grade 10 as from 2006. With the aim of improving learners’ performance in visual literacy I designed a visual literacy unit that consisted of lesson plans running over 7 periods in 10 school days. In implementing the unit the learners were first grouped and then exposed to visual grammar and visual texts and then they critically viewed such texts and designed their own. Data was collected daily in the form of individual learner journals, researcher’s journal/diary, and copies were kept of activities done by learners (individually or in groups). Also, two teachers were invited as non-participant observers to each visit a lesson. Learner focus groups were conducted and critical friends were interviewed, tape recorded and transcribed. A camera was used to take still photographs to show learner activities in groups and during group presentations. The data revealed that visual literacy could be taught meaningfully in a rural high school as the learners could identify, cut, paste and discuss elements of visual language and they finally designed their own advertisements in groups. In the analysis of data the following factors emerged as hindrances for successful teaching of visual literacy in a rural high school: lack of resources; learners’ lack of a foundation in visual literacy from Grades 7-9; and problems revolving around time management and pacing. As action research comes in spirals, this research represented the first one and the researcher found the study an eye opener and a foundation to build on in the second spiral (that is not part of this research).
- Full Text:
- Date Issued: 2007
Management of invasive aquatic weeds with emphasis on biological control in Senegal
- Authors: Diop, Ousseynou
- Date: 2007
- Subjects: Aquatic weeds -- Biological control -- Senegal Invasive plants -- Biological control -- Senegal Aquatic plants -- Biological control -- Senegal
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5728 , http://hdl.handle.net/10962/d1005414
- Description: In 1985 the Diama Dam was built near the mouth of the Senegal River to regulate flows during the rainy season and prevent the intrusion of seawater during the dry season. This created ideal conditions upstream of the dam wall for invasion by two highly invasive aquatic weeds, first by water lettuce Pistia stratiotes Linnaeus (Araceae) in 1993, and then by salvinia Salvinia molesta D.S. Mitchell (Salviniaceae) in 1999. This study was focused on the management of P. stratiotes and S. molesta. Following successes that were achieved elsewhere in the world, biological control programmes involving two weevil species were inaugurated against both weeds and research was focused on several aspects. These included pre-release studies to determine the weevils' host-specificity and impact on the plants in the laboratory, their subsequent mass-rearing and releases at selected sites and post-release evaluations on their impact on the weed populations in the field. Both programmes, which reprepresented the first biocontrol efforts against aquatic weeds in Senegal, proved highly successful with severe damage inflicted on the weed populations and complete control achieved within a relatively short time span. A laboratory exclusion experiment with N. affinis on P. stratiotes showed that in treated tubs, the weevil strongly depressed plant performance as measured by the plant growth parameters: mass, rosette diameter, root length, number of leaves and daughter plants whereas control plants were healthy. Field releases started in September 1994 and water coverage by P. stratiotes at Lake Guiers was reduced by 25% in January 1995 and 50% in April 1995. A general decline of 65% in water coverage by P. stratiotes was observed in June 1995 and by August 1995, eight months after releases P. stratiotes mats were destroyed. Further, although no releases were made there, good results were obtained within 18 months at Djoudj Park water bodies, located 150 km NW from Lake Guiers indicating the potential of the weevil to disperse long distances. In 2005, P. stratiotes reappeared and the weevil N. affinis has located and controlled all of these P. stratiotes recurrences after new releases. In 1999, S. molesta covered an estimated area of 18 000 ha on the Senegal River Left Bank and tributaries (Senegal) and 7 840 ha on the Senegal River Right Bank (Mauritania). Military and Civil Development Committee (CCMAD) and community volunteers made an effort to control S. molesta using physical removal, but this costly and labour-intensive approach was unsustainable. Hence, biological control was adopted by Senegal and Mauritania to manage the weed. Host range tests to assess feeding by C. salviniae on S. molesta and non-target plants and carried out on 13 crop species showed that no feeding damage was observed on the latter and weevils only fed on S. molesta. Field releases of some 48 953 weevils at 270 sites were made from early January 2002 to August 2002. Within one year, weevils were established and were being recovered up to 50 km from the release sites. In a case study conducted at one of the release sites, the S. molesta infestation was reduced from 100% to less than 3% 24 months after release. These results are discussed in the context of the weeds’ negative impact on aquatic systems and riverside communities, and in the involvement of these communities in the programmes.
- Full Text:
- Date Issued: 2007
- Authors: Diop, Ousseynou
- Date: 2007
- Subjects: Aquatic weeds -- Biological control -- Senegal Invasive plants -- Biological control -- Senegal Aquatic plants -- Biological control -- Senegal
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5728 , http://hdl.handle.net/10962/d1005414
- Description: In 1985 the Diama Dam was built near the mouth of the Senegal River to regulate flows during the rainy season and prevent the intrusion of seawater during the dry season. This created ideal conditions upstream of the dam wall for invasion by two highly invasive aquatic weeds, first by water lettuce Pistia stratiotes Linnaeus (Araceae) in 1993, and then by salvinia Salvinia molesta D.S. Mitchell (Salviniaceae) in 1999. This study was focused on the management of P. stratiotes and S. molesta. Following successes that were achieved elsewhere in the world, biological control programmes involving two weevil species were inaugurated against both weeds and research was focused on several aspects. These included pre-release studies to determine the weevils' host-specificity and impact on the plants in the laboratory, their subsequent mass-rearing and releases at selected sites and post-release evaluations on their impact on the weed populations in the field. Both programmes, which reprepresented the first biocontrol efforts against aquatic weeds in Senegal, proved highly successful with severe damage inflicted on the weed populations and complete control achieved within a relatively short time span. A laboratory exclusion experiment with N. affinis on P. stratiotes showed that in treated tubs, the weevil strongly depressed plant performance as measured by the plant growth parameters: mass, rosette diameter, root length, number of leaves and daughter plants whereas control plants were healthy. Field releases started in September 1994 and water coverage by P. stratiotes at Lake Guiers was reduced by 25% in January 1995 and 50% in April 1995. A general decline of 65% in water coverage by P. stratiotes was observed in June 1995 and by August 1995, eight months after releases P. stratiotes mats were destroyed. Further, although no releases were made there, good results were obtained within 18 months at Djoudj Park water bodies, located 150 km NW from Lake Guiers indicating the potential of the weevil to disperse long distances. In 2005, P. stratiotes reappeared and the weevil N. affinis has located and controlled all of these P. stratiotes recurrences after new releases. In 1999, S. molesta covered an estimated area of 18 000 ha on the Senegal River Left Bank and tributaries (Senegal) and 7 840 ha on the Senegal River Right Bank (Mauritania). Military and Civil Development Committee (CCMAD) and community volunteers made an effort to control S. molesta using physical removal, but this costly and labour-intensive approach was unsustainable. Hence, biological control was adopted by Senegal and Mauritania to manage the weed. Host range tests to assess feeding by C. salviniae on S. molesta and non-target plants and carried out on 13 crop species showed that no feeding damage was observed on the latter and weevils only fed on S. molesta. Field releases of some 48 953 weevils at 270 sites were made from early January 2002 to August 2002. Within one year, weevils were established and were being recovered up to 50 km from the release sites. In a case study conducted at one of the release sites, the S. molesta infestation was reduced from 100% to less than 3% 24 months after release. These results are discussed in the context of the weeds’ negative impact on aquatic systems and riverside communities, and in the involvement of these communities in the programmes.
- Full Text:
- Date Issued: 2007
Marital turnarounds : an exploratory qualitative study
- Authors: Ntlokwana, Nomalungelo
- Date: 2007
- Subjects: Remarriage -- South Africa -- Nelson Mandela Metropole
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9933 , http://hdl.handle.net/10948/585 , Remarriage -- South Africa -- Nelson Mandela Metropole
- Description: The purpose of this study was to study marital turnarounds by focusing on the exploration of the reasons for couples remarrying each other. A comprehensive approach based on human ecology provided a framework for exploring the reasons for marital turnarounds ranging from micro to macro level factors. Data was collected through six semi-structured interviews, with two African marital turnaround couples from the Nelson Mandela Metropole. Data analysis was carried out systematically through a stepwise process. Data verification and trustworthiness was also performed. Five major themes emerged from the data analysis of the interviews as follows: Culture and religious influences, individual influences, personal growth, family influences and the influence of friends. Culture and religion emerged as powerful theme in shaping decisions about marital turnaround. An important sub-theme was that, in a culture that continues to value marriage as a permanent commitment, spouses internalised the social and religious norm of marriage as a permanent commitment.
- Full Text:
- Date Issued: 2007
- Authors: Ntlokwana, Nomalungelo
- Date: 2007
- Subjects: Remarriage -- South Africa -- Nelson Mandela Metropole
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9933 , http://hdl.handle.net/10948/585 , Remarriage -- South Africa -- Nelson Mandela Metropole
- Description: The purpose of this study was to study marital turnarounds by focusing on the exploration of the reasons for couples remarrying each other. A comprehensive approach based on human ecology provided a framework for exploring the reasons for marital turnarounds ranging from micro to macro level factors. Data was collected through six semi-structured interviews, with two African marital turnaround couples from the Nelson Mandela Metropole. Data analysis was carried out systematically through a stepwise process. Data verification and trustworthiness was also performed. Five major themes emerged from the data analysis of the interviews as follows: Culture and religious influences, individual influences, personal growth, family influences and the influence of friends. Culture and religion emerged as powerful theme in shaping decisions about marital turnaround. An important sub-theme was that, in a culture that continues to value marriage as a permanent commitment, spouses internalised the social and religious norm of marriage as a permanent commitment.
- Full Text:
- Date Issued: 2007
Measuring the RFI environment of the South African SKA site
- Authors: Manners, Paul John
- Date: 2007
- Subjects: Radio telescopes , Radio telescopes -- South Africa , Radio astronomy , Radio astronomy -- South Africa , Square Kilometer Array (Spacecraft) , Radio -- Interference -- Measurement
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5474 , http://hdl.handle.net/10962/d1005259 , Radio telescopes , Radio telescopes -- South Africa , Radio astronomy , Radio astronomy -- South Africa , Square Kilometer Array (Spacecraft) , Radio -- Interference -- Measurement
- Description: The Square Kilometre Array (SKA) Project is an international effort to build the world’s largest radio telescope. It will be 100 times more sensitive than any other radio telescope currently in existence and will consist of thousands of dishes placed at baselines up to 3000 km. In addition to its increased sensitivity it will operate over a very wide frequency range (current specification is 100 MHz - 22 GHz) and will use frequency bands not primarily allocated to radio astronomy. Because of this the telescope needs to be located at a site with low levels of radio frequency interference (RFI). This implies a site that is remote and away from human activity. In bidding to host the SKA, South Africa was required to conduct an RFI survey at its proposed site for a period of 12 months. Apart from this core site, where more than half the SKA dishes may potentially be deployed, the measurement of remote sites in Southern Africa was also required. To conduct measurements at these sites, three mobile measurement systems were designed and built by the South African SKA Project. The design considerations, implementation and RFI measurements recorded during this campaign will be the focus for this dissertation.
- Full Text:
- Date Issued: 2007
- Authors: Manners, Paul John
- Date: 2007
- Subjects: Radio telescopes , Radio telescopes -- South Africa , Radio astronomy , Radio astronomy -- South Africa , Square Kilometer Array (Spacecraft) , Radio -- Interference -- Measurement
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5474 , http://hdl.handle.net/10962/d1005259 , Radio telescopes , Radio telescopes -- South Africa , Radio astronomy , Radio astronomy -- South Africa , Square Kilometer Array (Spacecraft) , Radio -- Interference -- Measurement
- Description: The Square Kilometre Array (SKA) Project is an international effort to build the world’s largest radio telescope. It will be 100 times more sensitive than any other radio telescope currently in existence and will consist of thousands of dishes placed at baselines up to 3000 km. In addition to its increased sensitivity it will operate over a very wide frequency range (current specification is 100 MHz - 22 GHz) and will use frequency bands not primarily allocated to radio astronomy. Because of this the telescope needs to be located at a site with low levels of radio frequency interference (RFI). This implies a site that is remote and away from human activity. In bidding to host the SKA, South Africa was required to conduct an RFI survey at its proposed site for a period of 12 months. Apart from this core site, where more than half the SKA dishes may potentially be deployed, the measurement of remote sites in Southern Africa was also required. To conduct measurements at these sites, three mobile measurement systems were designed and built by the South African SKA Project. The design considerations, implementation and RFI measurements recorded during this campaign will be the focus for this dissertation.
- Full Text:
- Date Issued: 2007
Micellar-enhanced ultrafiltration of palladium and platinum anions
- Authors: Gwicana, Sakumzi
- Date: 2007
- Subjects: Micelles , Ultrafiltration , Palladium catalysts
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10414 , http://hdl.handle.net/10948/518 , Micelles , Ultrafiltration , Palladium catalysts
- Description: The project was concerned with studying the capability of a micellar-enhanced ultrafiltration system (MEUF) to remove platinum group metal ions namely Pt (lV) and Pd (ll) chloro anions from aqueous industrial waste effluents. South Africa has the world’s largest reserves of platinum group metals (PGMs) and other valuable metals such as manganese, chrome ores, titanium minerals etc. which are required for new automotive and other technologies, including fuel cells, catalytic converters and lighter components. The consistent loss with the industrial waste stream and the toxicological effects of these precious metals led to the need to develop new and effective methods to recover them from industrial waste effluents. With such a wide variety of fields where these PGMs are used and the failure of the traditional techniques namely sedimentation, fermentation etc. to effectively reduce or recover these highly toxic and precious metal ions prior to discharging industrial waste effluents, it is necessary to explore other techniques such as membrane technology that can be used to recover these valuable species from industrial waste streams. The present study involved the use of a cationic surfactant, viz cetylpyridinium chloride, which was introduced into an aqueous solution containing palladium and platinum metal anions. The surfactant forms charged micelles above a certain critical concentration value. The metal anions adsorb onto the available oppositely charged sites on the micelle surfaces and are then able to be retained by a suitable membrane. Hollow fibre ultrafiltration membranes with the MWCO of +/- 10 kD and +/-30nm pore size were used as a filter component in this study. For this MEUF system to be effective, it was vital that the anionic metal ion species adsorbed sufficiently onto the available oppositely charged sites of the micelles and that the micelles were retained efficiently by the membrane. Results obtained during the investigation made it possible to make certain predictions about the micellisation process. It was also found that, it was not only the metal ion: surfactant (M:S) ratio that was critical, but the presence of other electrolytes in the aqueous stream proved to have a huge impact on the capability of the MEUF system. Findings of this research study showed that the MEUF system using cetylpyridinium chloride (CPC) can be used to recover or retain Pt (lV) and Pd (ll) anions from industrial waste effluents. It was also found that PtCl6 2-, due to its greater adsorption capabilities onto the micelle surface than PdCl4 2- or PdCl3(H2O)-, was preferentially retained in neutral medium. This may be exploited as a possible means of separating the two metal ions. The developed system offers the following advantages over some traditional and current methods: simplified unit operation line flow process, smaller amounts of chemical usage and no solid toxic sludge to be disposed of. Applications of this work could be of vital importance in catalytic converter recycling, especially in Port Elizabeth where extensive automobile parts manufacturing occurs.
- Full Text:
- Date Issued: 2007
- Authors: Gwicana, Sakumzi
- Date: 2007
- Subjects: Micelles , Ultrafiltration , Palladium catalysts
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10414 , http://hdl.handle.net/10948/518 , Micelles , Ultrafiltration , Palladium catalysts
- Description: The project was concerned with studying the capability of a micellar-enhanced ultrafiltration system (MEUF) to remove platinum group metal ions namely Pt (lV) and Pd (ll) chloro anions from aqueous industrial waste effluents. South Africa has the world’s largest reserves of platinum group metals (PGMs) and other valuable metals such as manganese, chrome ores, titanium minerals etc. which are required for new automotive and other technologies, including fuel cells, catalytic converters and lighter components. The consistent loss with the industrial waste stream and the toxicological effects of these precious metals led to the need to develop new and effective methods to recover them from industrial waste effluents. With such a wide variety of fields where these PGMs are used and the failure of the traditional techniques namely sedimentation, fermentation etc. to effectively reduce or recover these highly toxic and precious metal ions prior to discharging industrial waste effluents, it is necessary to explore other techniques such as membrane technology that can be used to recover these valuable species from industrial waste streams. The present study involved the use of a cationic surfactant, viz cetylpyridinium chloride, which was introduced into an aqueous solution containing palladium and platinum metal anions. The surfactant forms charged micelles above a certain critical concentration value. The metal anions adsorb onto the available oppositely charged sites on the micelle surfaces and are then able to be retained by a suitable membrane. Hollow fibre ultrafiltration membranes with the MWCO of +/- 10 kD and +/-30nm pore size were used as a filter component in this study. For this MEUF system to be effective, it was vital that the anionic metal ion species adsorbed sufficiently onto the available oppositely charged sites of the micelles and that the micelles were retained efficiently by the membrane. Results obtained during the investigation made it possible to make certain predictions about the micellisation process. It was also found that, it was not only the metal ion: surfactant (M:S) ratio that was critical, but the presence of other electrolytes in the aqueous stream proved to have a huge impact on the capability of the MEUF system. Findings of this research study showed that the MEUF system using cetylpyridinium chloride (CPC) can be used to recover or retain Pt (lV) and Pd (ll) anions from industrial waste effluents. It was also found that PtCl6 2-, due to its greater adsorption capabilities onto the micelle surface than PdCl4 2- or PdCl3(H2O)-, was preferentially retained in neutral medium. This may be exploited as a possible means of separating the two metal ions. The developed system offers the following advantages over some traditional and current methods: simplified unit operation line flow process, smaller amounts of chemical usage and no solid toxic sludge to be disposed of. Applications of this work could be of vital importance in catalytic converter recycling, especially in Port Elizabeth where extensive automobile parts manufacturing occurs.
- Full Text:
- Date Issued: 2007
MISSTEV : model for information security shared tacit espoused values
- Authors: Thomson, Kerry-Lynn
- Date: 2007
- Subjects: Computer security -- Management , Management information systems -- Security measures , Data protection
- Language: English
- Type: Thesis , Doctoral , DTech
- Identifier: vital:9787 , http://hdl.handle.net/10948/717 , Computer security -- Management , Management information systems -- Security measures , Data protection
- Description: One of the most critical assets in most organisations is information. It is often described as the lifeblood of an organisation. For this reason, it is vital that this asset is protected through sound information security practices. However, the incorrect and indifferent behaviour of employees often leads to information assets becoming vulnerable. Incorrect employee behaviour could have an extremely negative impact on the protection of information. An information security solution should be a fundamental component in most organisations. It is, however, possible for an organisation to have the most comprehensive physical and technical information security controls in place, but the operational controls, and associated employee behaviour, have not received much consideration. Therefore, the issue of employee behaviour must be addressed in an organisation to assist in ensuring the protection of information assets. The corporate culture of an organisation is largely responsible for the actions and behaviour of employees. Therefore, to address operational information security controls, the corporate culture of an organisation should be considered. To ensure the integration of information security into the corporate culture of an organisation, the protection of information should become part of the way the employees conduct their everyday tasks – from senior management, right throughout the entire organisation. Therefore, information security should become an integral component of the corporate culture of the organisation. To address the integration of information security into the corporate culture of an organisation, a model was developed which depicted the learning stages and modes of knowledge creation necessary to transform the corporate culture into one that is information security aware.
- Full Text:
- Date Issued: 2007
- Authors: Thomson, Kerry-Lynn
- Date: 2007
- Subjects: Computer security -- Management , Management information systems -- Security measures , Data protection
- Language: English
- Type: Thesis , Doctoral , DTech
- Identifier: vital:9787 , http://hdl.handle.net/10948/717 , Computer security -- Management , Management information systems -- Security measures , Data protection
- Description: One of the most critical assets in most organisations is information. It is often described as the lifeblood of an organisation. For this reason, it is vital that this asset is protected through sound information security practices. However, the incorrect and indifferent behaviour of employees often leads to information assets becoming vulnerable. Incorrect employee behaviour could have an extremely negative impact on the protection of information. An information security solution should be a fundamental component in most organisations. It is, however, possible for an organisation to have the most comprehensive physical and technical information security controls in place, but the operational controls, and associated employee behaviour, have not received much consideration. Therefore, the issue of employee behaviour must be addressed in an organisation to assist in ensuring the protection of information assets. The corporate culture of an organisation is largely responsible for the actions and behaviour of employees. Therefore, to address operational information security controls, the corporate culture of an organisation should be considered. To ensure the integration of information security into the corporate culture of an organisation, the protection of information should become part of the way the employees conduct their everyday tasks – from senior management, right throughout the entire organisation. Therefore, information security should become an integral component of the corporate culture of the organisation. To address the integration of information security into the corporate culture of an organisation, a model was developed which depicted the learning stages and modes of knowledge creation necessary to transform the corporate culture into one that is information security aware.
- Full Text:
- Date Issued: 2007