Characterisation of the J domain aminoacid residues important for the interaction of DNAJ-like proteins with HSP70 chaperones
- Authors: Hennessy, Fritha
- Date: 2004
- Subjects: Heat shock proteins Protein folding Proteins -- Analysis Proteins -- Structure Molecular chaperones
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3937 , http://hdl.handle.net/10962/d1003996
- Description: The 70 kDa heat shock proteins (Hsp70s) are vital for normal protein folding, as they stabilise the unfolded state of nascent polypeptides, allowing these sufficient time to attain a correct tertiary structure. Hsp70s are aided by the DnaJ-like family of proteins, which interact with Hsp70s in order to enhance the chaperone activity of these proteins. DnaJ-like proteins contain a J domain, a seventy amino acid domain consisting of four α-helices, which is defined by the presence of an invariant tripeptide of histidine, proline and aspartic acid (HPD motif). This motif is key to the interaction between DnaJ-like proteins and Hsp70s. This thesis has focused on determining the presence of other conserved residues in the J domain and their role in mediating the interaction of DnaJ-like proteins with partner Hsp70s. DnaJ-like proteins from Agrobacterium tumefaciens RUOR were isolated and used as a model system. A. tumefaciens DnaJ (Agt DnaJ) was able to replace the lack of E. coli DnaJ in an E. coli null mutant strain, however, additional A. tumefaciens DnaJ-like proteins Agt DjC1/DjlA, Agt DjC2 and Agt DjC5 were unable to complement for the lack of E. coli DnaJ. Replacement of the Agt DnaJ J domain with J domains from these proteins resulted in non-functional chimeric proteins, despite some sequence conservation. The kinetics of the basal specific ATPase activity of Agt DnaK, and its ability to have this activity stimulated by Agt DnaJ and Agt DnaJ-H33Q were also investigated. Stimulation of the ATPase activity by Agt DnaJ ranged between 1.5 to 2 fold, but Agt DnaJ-H33Q was unable to stimulate the basal ATPase activity. Conserved amino acids in the J domain were identified in silico, and these residues were substituted in the J domain of Agt DnaJ. The ability of these derivative proteins to replace E. coli DnaJ was investigated. Alterations in the HPD motif gave rise to proteins unable to complement for lack of E. coli DnaJ, consistent with literature. Agt DnaJ-R26A was unable to replace E. coli DnaJ suggesting that Arg26 could be key to the interaction with partner Hsp70s. Agt DnaJ-D59A was unable to replace E. coli DnaJ; substitutions in Asp59 have not previously been shown to impact on the function of DnaJ. Substituting Arg63 in Agt DnaJ abrogated the levels of complementation. Substitution of several structural residues was also found to disrupt the in vivo function of Agt DnaJ suggesting that the maintenance of the structural integrity of the J domain was important for function. This study has identified a number of residues critical to the structure and function of the J domain of Agt DnaJ, and potentially of general importance as molecular determinants for DnaJ-Hsp70 interaction.
- Full Text:
- Date Issued: 2004
- Authors: Hennessy, Fritha
- Date: 2004
- Subjects: Heat shock proteins Protein folding Proteins -- Analysis Proteins -- Structure Molecular chaperones
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3937 , http://hdl.handle.net/10962/d1003996
- Description: The 70 kDa heat shock proteins (Hsp70s) are vital for normal protein folding, as they stabilise the unfolded state of nascent polypeptides, allowing these sufficient time to attain a correct tertiary structure. Hsp70s are aided by the DnaJ-like family of proteins, which interact with Hsp70s in order to enhance the chaperone activity of these proteins. DnaJ-like proteins contain a J domain, a seventy amino acid domain consisting of four α-helices, which is defined by the presence of an invariant tripeptide of histidine, proline and aspartic acid (HPD motif). This motif is key to the interaction between DnaJ-like proteins and Hsp70s. This thesis has focused on determining the presence of other conserved residues in the J domain and their role in mediating the interaction of DnaJ-like proteins with partner Hsp70s. DnaJ-like proteins from Agrobacterium tumefaciens RUOR were isolated and used as a model system. A. tumefaciens DnaJ (Agt DnaJ) was able to replace the lack of E. coli DnaJ in an E. coli null mutant strain, however, additional A. tumefaciens DnaJ-like proteins Agt DjC1/DjlA, Agt DjC2 and Agt DjC5 were unable to complement for the lack of E. coli DnaJ. Replacement of the Agt DnaJ J domain with J domains from these proteins resulted in non-functional chimeric proteins, despite some sequence conservation. The kinetics of the basal specific ATPase activity of Agt DnaK, and its ability to have this activity stimulated by Agt DnaJ and Agt DnaJ-H33Q were also investigated. Stimulation of the ATPase activity by Agt DnaJ ranged between 1.5 to 2 fold, but Agt DnaJ-H33Q was unable to stimulate the basal ATPase activity. Conserved amino acids in the J domain were identified in silico, and these residues were substituted in the J domain of Agt DnaJ. The ability of these derivative proteins to replace E. coli DnaJ was investigated. Alterations in the HPD motif gave rise to proteins unable to complement for lack of E. coli DnaJ, consistent with literature. Agt DnaJ-R26A was unable to replace E. coli DnaJ suggesting that Arg26 could be key to the interaction with partner Hsp70s. Agt DnaJ-D59A was unable to replace E. coli DnaJ; substitutions in Asp59 have not previously been shown to impact on the function of DnaJ. Substituting Arg63 in Agt DnaJ abrogated the levels of complementation. Substitution of several structural residues was also found to disrupt the in vivo function of Agt DnaJ suggesting that the maintenance of the structural integrity of the J domain was important for function. This study has identified a number of residues critical to the structure and function of the J domain of Agt DnaJ, and potentially of general importance as molecular determinants for DnaJ-Hsp70 interaction.
- Full Text:
- Date Issued: 2004
Cleaning of fouled membranes using enzymes from a sulphidogenic bioreactor
- Authors: Melamane, Xolisa L
- Date: 2004
- Subjects: Membrane filters , Membrane filters -- Fouling , Enzymes -- Biotechnology , Enzymes -- Purification , Water -- Purification -- Membrane filtration , Ultrafiltration
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4133 , http://hdl.handle.net/10962/d1015764
- Description: Maintenance of membrane performance requires inevitable cleaning or defouling of fouled membranes. Membrane cleaning using enzymes such as proteases, lipases, α-glucosidases from a sulphidogenic bioreactor was investigated. At first, dilute and concentrated enzyme extract were prepared form the sulphidogenic pellet. Enzyme assays on 0.5 % azocaisen, 1 % triacetin and 1 mg/ml ρ-nitrophenyl-α-D-glucopyranoside were performed using the concentrated enzyme extract (0 – 200 mg/ml). For membrane fouling, an abattoir effluent was obtained from Ostritech Pty (Ltd), Grahamstown, South Africa. The effluent was characterised for presence of potential foulants such as lipids, proteins, amino acids and carbohydrates. Static fouling of polysulphone membranes (0.22 μm, 47 mm) was then performed using the abattoir effluent. Cleaning of the fouled membranes was also performed using at first the dilute and then the concentrated form (200 mg/ml) of enzyme extracts. Qualitative and quantitative biochemical analysis for proteins, lipids and carbohydrates was performed to ascertain the presence of foulants on polysulphone membranes and their removal by dilute or concentrated enzyme extracts. The ability of dilute enzyme extracts to remove proteins lipids, and carbohydrates fouling capillary UF membrane module; their ability to restore permeate fluxes and transmembrane pressure after cleaning/defouling was also investigated. Permeate volumes from this UF membrane module were analysed for protein, amino acids, lipids, and carbohydrates concentrations after fouling and defouling. Fouling was further characterized by standard blocking, cake filtration and pore blocking models using stirred UF cell and polyethersulphone membranes with MWCO of 30 000, 100 000 and 300 000. After characterization of fouling, polyethersulphone membranes with MWCO of 30 000 and 300 000 were defouled using the concentrated enzyme extract (100 mg ml). Enzyme activities at 200 mg/ml of enzyme concentration were 8.071 IU, 86.71 IU and 789.02 IU for proteases, lipases and α-glucosidases. The abattoir effluent contained 553 μg/ml of lipid, 301 μg/ml of protein, 141 μg/ml of total carbohydrate, and 0.63 μg/ml of total reducing sugars. Proteins, lipids and carbohydrates fouling polysulphone membranes after a day were removed by 23.4 %, when a dilute enzyme was used. A concentrated enzyme extract of 200 mg/ml was able to remove proteins, lipids and carbohydrates up to 5 days of fouling by 100 %, 82 %, 71 %, 68 % and 76 % respectively. Defouling of dynamically fouled capillary ultrafiltration membranes using sulphidogenic proteases was successful at pH 10, 37°C, within 1 hour. Sulphidogenic proteases activity was 2.1 U/ml and flux Recovery (FR %) was 64. Characterization of fouling revealed that proteins and lipids were major foulants while low concentration of carbohydrates fouled polyethersulphone membranes. Fouling followed standard blocking for 10 minutes in all the membranes; afterwards fouling adopted cake filtration model for membranes with 30 000 MWCO and pore blocking model for membranes with 300 000 MWCO. A concentration of 100 mg/ml of enzyme extract was able to remove fouling from membranes with MWCO of 30 000. Defouling membranes that followed pore blocking model i.e. 300 000 MWCO was not successful due to a mass transfer problem. From the results of defouling of 30 000 and 300 000 MWCO it was concluded that defouling of cake layer fouling (30 000 MWCO) was successful while defouling of pore blocking fouling was unsuccessful due to a mass transfer problem. The ratio of enzymes present in the enzyme extract when calculated based on enzymatic activity for proteases, lipases and α-glucosidases was 1.1 %, 11 % and 87.9 %. It was hypothesized that apart from proteases, lipases, α and β-glucosidases; phosphatases, sulphatases, amonipeptidases etc. from a sulphidogenic bioreactor clean or defoul cake layer fouling by organic foulants and pore blocking fouling provided the mass transfer problem is solved. However, concentration of enzymes from a sulphidogenic bioreactor has not been optimized yet. Other methods of concentrating the enzyme extract can be investigated for example use of organic solvents.
- Full Text:
- Date Issued: 2004
- Authors: Melamane, Xolisa L
- Date: 2004
- Subjects: Membrane filters , Membrane filters -- Fouling , Enzymes -- Biotechnology , Enzymes -- Purification , Water -- Purification -- Membrane filtration , Ultrafiltration
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4133 , http://hdl.handle.net/10962/d1015764
- Description: Maintenance of membrane performance requires inevitable cleaning or defouling of fouled membranes. Membrane cleaning using enzymes such as proteases, lipases, α-glucosidases from a sulphidogenic bioreactor was investigated. At first, dilute and concentrated enzyme extract were prepared form the sulphidogenic pellet. Enzyme assays on 0.5 % azocaisen, 1 % triacetin and 1 mg/ml ρ-nitrophenyl-α-D-glucopyranoside were performed using the concentrated enzyme extract (0 – 200 mg/ml). For membrane fouling, an abattoir effluent was obtained from Ostritech Pty (Ltd), Grahamstown, South Africa. The effluent was characterised for presence of potential foulants such as lipids, proteins, amino acids and carbohydrates. Static fouling of polysulphone membranes (0.22 μm, 47 mm) was then performed using the abattoir effluent. Cleaning of the fouled membranes was also performed using at first the dilute and then the concentrated form (200 mg/ml) of enzyme extracts. Qualitative and quantitative biochemical analysis for proteins, lipids and carbohydrates was performed to ascertain the presence of foulants on polysulphone membranes and their removal by dilute or concentrated enzyme extracts. The ability of dilute enzyme extracts to remove proteins lipids, and carbohydrates fouling capillary UF membrane module; their ability to restore permeate fluxes and transmembrane pressure after cleaning/defouling was also investigated. Permeate volumes from this UF membrane module were analysed for protein, amino acids, lipids, and carbohydrates concentrations after fouling and defouling. Fouling was further characterized by standard blocking, cake filtration and pore blocking models using stirred UF cell and polyethersulphone membranes with MWCO of 30 000, 100 000 and 300 000. After characterization of fouling, polyethersulphone membranes with MWCO of 30 000 and 300 000 were defouled using the concentrated enzyme extract (100 mg ml). Enzyme activities at 200 mg/ml of enzyme concentration were 8.071 IU, 86.71 IU and 789.02 IU for proteases, lipases and α-glucosidases. The abattoir effluent contained 553 μg/ml of lipid, 301 μg/ml of protein, 141 μg/ml of total carbohydrate, and 0.63 μg/ml of total reducing sugars. Proteins, lipids and carbohydrates fouling polysulphone membranes after a day were removed by 23.4 %, when a dilute enzyme was used. A concentrated enzyme extract of 200 mg/ml was able to remove proteins, lipids and carbohydrates up to 5 days of fouling by 100 %, 82 %, 71 %, 68 % and 76 % respectively. Defouling of dynamically fouled capillary ultrafiltration membranes using sulphidogenic proteases was successful at pH 10, 37°C, within 1 hour. Sulphidogenic proteases activity was 2.1 U/ml and flux Recovery (FR %) was 64. Characterization of fouling revealed that proteins and lipids were major foulants while low concentration of carbohydrates fouled polyethersulphone membranes. Fouling followed standard blocking for 10 minutes in all the membranes; afterwards fouling adopted cake filtration model for membranes with 30 000 MWCO and pore blocking model for membranes with 300 000 MWCO. A concentration of 100 mg/ml of enzyme extract was able to remove fouling from membranes with MWCO of 30 000. Defouling membranes that followed pore blocking model i.e. 300 000 MWCO was not successful due to a mass transfer problem. From the results of defouling of 30 000 and 300 000 MWCO it was concluded that defouling of cake layer fouling (30 000 MWCO) was successful while defouling of pore blocking fouling was unsuccessful due to a mass transfer problem. The ratio of enzymes present in the enzyme extract when calculated based on enzymatic activity for proteases, lipases and α-glucosidases was 1.1 %, 11 % and 87.9 %. It was hypothesized that apart from proteases, lipases, α and β-glucosidases; phosphatases, sulphatases, amonipeptidases etc. from a sulphidogenic bioreactor clean or defoul cake layer fouling by organic foulants and pore blocking fouling provided the mass transfer problem is solved. However, concentration of enzymes from a sulphidogenic bioreactor has not been optimized yet. Other methods of concentrating the enzyme extract can be investigated for example use of organic solvents.
- Full Text:
- Date Issued: 2004
Comparison of two granulation processes with the view to reduce manufacturing cost
- Authors: Maclean, Aldritt Allister
- Date: 2004
- Subjects: Drugs -- Granulation , Tablets (Medicine) , Pharmaceutical industry
- Language: English
- Type: Thesis , Masters , MTech (Chemistry)
- Identifier: vital:10980 , http://hdl.handle.net/10948/210 , Drugs -- Granulation , Tablets (Medicine) , Pharmaceutical industry
- Description: Aspen Pharmacare, one of the leading pharmaceutical manufacturers in South Africa has embarked on a programme of improving the production processes currently employed at their Port Elizabeth site. With the introduction of new technology at the site and the move towards globalization, it became imperative that Aspen remain competitive in the market. The product of interest in this research, Degoran Plus tablets, is one of the company’s leading brand sellers. Upon investigation, it became apparent that this product created opportunity for process improvement using the new technology. The manufacture of Degoran Plus entails granulation, compression and coating of the product. Most opportunity for improvement was possible in the granulation stage because of the laborious nature of the present process. Degoran Plus tablets had a history of analytical failures, especially with regard to the dissolution rate of the final product, as well as other quality related issues. The product was not considered to be a “through-runner”, which resulted in bad production output, due to continual repeats of not only analysis but also reworks in production. A strategic decision was taken to manufacture Degoran Plus using the Collette Gral granulator as the equipment offered superior mixing capability when compared to the Bear planetary granulator. It was assumed that the granulation process would result in more uniform distribution of the actives. Upon producing a better granule, a final product of superior quality would be attained. The validation protocol stipulates that three samples be taken and tested from the powder mix. Nine samples taken from granulated bulk are treated in the same manner. The validation protocol further stipulates that the first three batches manufactured utilise the new process, and tested according to the protocol. The results obtained from the analysis are evaluated statistically and a conclusion and recommendation were derived based on the evaluation.
- Full Text:
- Date Issued: 2004
- Authors: Maclean, Aldritt Allister
- Date: 2004
- Subjects: Drugs -- Granulation , Tablets (Medicine) , Pharmaceutical industry
- Language: English
- Type: Thesis , Masters , MTech (Chemistry)
- Identifier: vital:10980 , http://hdl.handle.net/10948/210 , Drugs -- Granulation , Tablets (Medicine) , Pharmaceutical industry
- Description: Aspen Pharmacare, one of the leading pharmaceutical manufacturers in South Africa has embarked on a programme of improving the production processes currently employed at their Port Elizabeth site. With the introduction of new technology at the site and the move towards globalization, it became imperative that Aspen remain competitive in the market. The product of interest in this research, Degoran Plus tablets, is one of the company’s leading brand sellers. Upon investigation, it became apparent that this product created opportunity for process improvement using the new technology. The manufacture of Degoran Plus entails granulation, compression and coating of the product. Most opportunity for improvement was possible in the granulation stage because of the laborious nature of the present process. Degoran Plus tablets had a history of analytical failures, especially with regard to the dissolution rate of the final product, as well as other quality related issues. The product was not considered to be a “through-runner”, which resulted in bad production output, due to continual repeats of not only analysis but also reworks in production. A strategic decision was taken to manufacture Degoran Plus using the Collette Gral granulator as the equipment offered superior mixing capability when compared to the Bear planetary granulator. It was assumed that the granulation process would result in more uniform distribution of the actives. Upon producing a better granule, a final product of superior quality would be attained. The validation protocol stipulates that three samples be taken and tested from the powder mix. Nine samples taken from granulated bulk are treated in the same manner. The validation protocol further stipulates that the first three batches manufactured utilise the new process, and tested according to the protocol. The results obtained from the analysis are evaluated statistically and a conclusion and recommendation were derived based on the evaluation.
- Full Text:
- Date Issued: 2004
Competition for attachment of aquaculture candidate probiotic and pathogenic bacteria on fish intestinal mucus:
- Vine, Niall G, Leukes, Winston D, Kaiser, Horst, Daya, Santylal, Baxter, Jeremy, Hecht, Thomas
- Authors: Vine, Niall G , Leukes, Winston D , Kaiser, Horst , Daya, Santylal , Baxter, Jeremy , Hecht, Thomas
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142819 , vital:38120 , DOI: 10.1111/j.1365-2761.2004.00542.x
- Description: Probiotics for aquaculture are generally only selected by their ability to produce antimicrobial metabolites; however, attachment to intestinal mucus is important in order to remain within the gut of its host. Five candidate probiotics (AP1–AP5), isolated from the clownfish, Amphiprion percula (Lacepéde), were examined for their ability to attach to fish intestinal mucus and compete with two pathogens, Aeromonas hydrophila and Vibrio alginolyticus. Two different radioactive isotopes were used to quantify competition between pathogens and probionts. Attachment of the pathogens was enhanced by the presence of the candidate probiotics. However, the addition of the candidate probiotics after the pathogens resulted in reduced pathogen attachment.
- Full Text:
- Date Issued: 2004
- Authors: Vine, Niall G , Leukes, Winston D , Kaiser, Horst , Daya, Santylal , Baxter, Jeremy , Hecht, Thomas
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142819 , vital:38120 , DOI: 10.1111/j.1365-2761.2004.00542.x
- Description: Probiotics for aquaculture are generally only selected by their ability to produce antimicrobial metabolites; however, attachment to intestinal mucus is important in order to remain within the gut of its host. Five candidate probiotics (AP1–AP5), isolated from the clownfish, Amphiprion percula (Lacepéde), were examined for their ability to attach to fish intestinal mucus and compete with two pathogens, Aeromonas hydrophila and Vibrio alginolyticus. Two different radioactive isotopes were used to quantify competition between pathogens and probionts. Attachment of the pathogens was enhanced by the presence of the candidate probiotics. However, the addition of the candidate probiotics after the pathogens resulted in reduced pathogen attachment.
- Full Text:
- Date Issued: 2004
Composition portfolio
- Authors: Prince, Lloyd T
- Date: 2004
- Subjects: Music -- South Africa Composition (Music)
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:2652 , http://hdl.handle.net/10962/d1002318
- Full Text:
- Date Issued: 2004
- Authors: Prince, Lloyd T
- Date: 2004
- Subjects: Music -- South Africa Composition (Music)
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:2652 , http://hdl.handle.net/10962/d1002318
- Full Text:
- Date Issued: 2004
Concerning secondary thermoluminescence peaks in α-Al_2_O_3_:C
- Authors: Chithambo, Makaiko L
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6793 , http://hdl.handle.net/10962/d1003823
- Description: Thermoluminescence characteristics of two subsidiary glow peaks, one below 100°C and the other above 300°C, have been studied for measurements between 30°C and 500°C in α-Al_2_O_3_:C. The thermoluminescence intensity of the lower temperature peak decreased with storage with a half-life of about 150 s. In contrast, the intensity of the higher temperature peak increased with storage towards some maximum. The peak-temperature of each of the secondary glow peaks was essentially constant with dose, whereas that of the main peak decreased with irradiation. The dose response for the three peaks was similar except for sublinear growth in the higher temperature peak at low dose values. These effects are discussed in terms of changes in the concentration of F+ luminescence precursors brought about by competitive electron retrapping at deep electron-traps or hole-traps. This work refines the physics and application of α-Al_2_O_3_:C luminescence in radiation dosimetry.
- Full Text:
- Date Issued: 2004
- Authors: Chithambo, Makaiko L
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6793 , http://hdl.handle.net/10962/d1003823
- Description: Thermoluminescence characteristics of two subsidiary glow peaks, one below 100°C and the other above 300°C, have been studied for measurements between 30°C and 500°C in α-Al_2_O_3_:C. The thermoluminescence intensity of the lower temperature peak decreased with storage with a half-life of about 150 s. In contrast, the intensity of the higher temperature peak increased with storage towards some maximum. The peak-temperature of each of the secondary glow peaks was essentially constant with dose, whereas that of the main peak decreased with irradiation. The dose response for the three peaks was similar except for sublinear growth in the higher temperature peak at low dose values. These effects are discussed in terms of changes in the concentration of F+ luminescence precursors brought about by competitive electron retrapping at deep electron-traps or hole-traps. This work refines the physics and application of α-Al_2_O_3_:C luminescence in radiation dosimetry.
- Full Text:
- Date Issued: 2004
Constructing a cardinal measure of democratic development in a transition polity: the Nigerian example
- Dinneya, Godson E, Tsegaye, Asrat
- Authors: Dinneya, Godson E , Tsegaye, Asrat
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6076 , http://hdl.handle.net/10962/d1003837
- Description: Existing measures of the level of democracy present in a given state treat democracy as a product and therefore place undue emphasis on actual freedoms enjoyed by the citizens of the country. In transition polities where the actual levels of freedom are low despite continuing efforts to democratize, democracy should be seen as a process rather than a product. A measure that dilutes the end product to capture today's struggles against undemocratic structures and policies does so in order to recognize the foundations these inputs lay for future democratic development. Nigeria exemplifies the many polities in transition on the African continent. This essay looks at the major political events that typify the processes of power change, quality of governance, political environment and democratic dividends, and uses them to construct democratization indices to determine the pattern and level of democratization in Nigeria since political independence. This exercise sets the stage for assessing the impacts of various dimensions of democratization on the performance of the Nigerian economy.
- Full Text:
- Date Issued: 2004
- Authors: Dinneya, Godson E , Tsegaye, Asrat
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6076 , http://hdl.handle.net/10962/d1003837
- Description: Existing measures of the level of democracy present in a given state treat democracy as a product and therefore place undue emphasis on actual freedoms enjoyed by the citizens of the country. In transition polities where the actual levels of freedom are low despite continuing efforts to democratize, democracy should be seen as a process rather than a product. A measure that dilutes the end product to capture today's struggles against undemocratic structures and policies does so in order to recognize the foundations these inputs lay for future democratic development. Nigeria exemplifies the many polities in transition on the African continent. This essay looks at the major political events that typify the processes of power change, quality of governance, political environment and democratic dividends, and uses them to construct democratization indices to determine the pattern and level of democratization in Nigeria since political independence. This exercise sets the stage for assessing the impacts of various dimensions of democratization on the performance of the Nigerian economy.
- Full Text:
- Date Issued: 2004
Consumer decision making styles: a comparative study among Motswana, Chinese and South African students
- Authors: Li, Yuejin
- Date: 2004
- Subjects: Consumer behavior -- China , Consumer behavior -- Botswana , Consumer behavior -- South Africa , Young consumers , Caucasian race
- Language: English
- Type: Thesis , Masters , MTech (Marketing)
- Identifier: vital:10771 , http://hdl.handle.net/10948/154 , Consumer behavior -- China , Consumer behavior -- Botswana , Consumer behavior -- South Africa , Young consumers , Caucasian race
- Description: As the global marketplace becomes more integrated and consumer specialists develop an international focus, developing useful scales to profile consumer decision-making styles in other cultures becomes important. Comparing the decision-making styles of consumers from different countries would thus contribute to the understanding of the effect of the marketing environment as well as of the cultural factors on consumer decision-making styles. It would also be significant to determine if the decision-making styles of foreign consumers differ from those of local ones. The influx of foreign students enrolled at South African Universities and Technikons has resulted in an increase in the number of consumers who have to make purchases connected to their daily lives within a different cultural environment. An understanding of students as consumers and their decisionmaking processes is important to marketers, particularly as students are recognised as a specialised market segment for a variety of goods and services. It would thus be significant to determine if the decision-making styles of foreign students differ from those of local students. This exploratory study investigates the decision-making styles among Chinese, Motswana and South African Caucasian students in a South African context, with a view of verifying the international applicability of the Consumer Styles Inventory (CSI) developed by Sproles and Kendall (1986). Only students with a Caucasian background were included in an attempt to avoid the influence of the different subcultures amongst South African students. It was found that Sproles and Kendall’s (1986) model did not fit the South African samples. It was furthermore found that differences exist among Motswana, Chinese and Caucasian students in consumer decision-making styles. The mean value for the “Novelty-fashion conscious” style was number one in the list of factors for Chinese and Motswana students and second for the Caucasian sample. “Price conscious” style, however, was number one for the Caucasian students.
- Full Text:
- Date Issued: 2004
- Authors: Li, Yuejin
- Date: 2004
- Subjects: Consumer behavior -- China , Consumer behavior -- Botswana , Consumer behavior -- South Africa , Young consumers , Caucasian race
- Language: English
- Type: Thesis , Masters , MTech (Marketing)
- Identifier: vital:10771 , http://hdl.handle.net/10948/154 , Consumer behavior -- China , Consumer behavior -- Botswana , Consumer behavior -- South Africa , Young consumers , Caucasian race
- Description: As the global marketplace becomes more integrated and consumer specialists develop an international focus, developing useful scales to profile consumer decision-making styles in other cultures becomes important. Comparing the decision-making styles of consumers from different countries would thus contribute to the understanding of the effect of the marketing environment as well as of the cultural factors on consumer decision-making styles. It would also be significant to determine if the decision-making styles of foreign consumers differ from those of local ones. The influx of foreign students enrolled at South African Universities and Technikons has resulted in an increase in the number of consumers who have to make purchases connected to their daily lives within a different cultural environment. An understanding of students as consumers and their decisionmaking processes is important to marketers, particularly as students are recognised as a specialised market segment for a variety of goods and services. It would thus be significant to determine if the decision-making styles of foreign students differ from those of local students. This exploratory study investigates the decision-making styles among Chinese, Motswana and South African Caucasian students in a South African context, with a view of verifying the international applicability of the Consumer Styles Inventory (CSI) developed by Sproles and Kendall (1986). Only students with a Caucasian background were included in an attempt to avoid the influence of the different subcultures amongst South African students. It was found that Sproles and Kendall’s (1986) model did not fit the South African samples. It was furthermore found that differences exist among Motswana, Chinese and Caucasian students in consumer decision-making styles. The mean value for the “Novelty-fashion conscious” style was number one in the list of factors for Chinese and Motswana students and second for the Caucasian sample. “Price conscious” style, however, was number one for the Caucasian students.
- Full Text:
- Date Issued: 2004
Contested rights : the impact of game farming on farm workers in the Bushmen's River area
- Authors: Luck, Kelly
- Date: 2004
- Subjects: Game farms -- South Africa -- Eastern Cape , Agricultural laborers -- South Africa -- Eastern Cape -- Social conditions Agricultural laborers -- South Africa -- Eastern Cape -- Economic conditions Agricultural laborers -- Political aspects -- South Africa -- Eastern Cape Agricultural laborers -- Legal status, laws, etc. -- South Africa -- Eastern Cape Agricultural laborers -- Protection -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2104 , http://hdl.handle.net/10962/d1004144
- Description: This thesis is an investigation of the impact of commercial game farming on former farm workers in the Bushman's River area of the Eastern Cape. In its examination of the broader economic and political changes that have facilitated a move from agriculture to game farming, it analyses how these changes affect farm workers. The main concern of the thesis is the ways in which farm workers (at the local level) respond to changes at the national and global level (legal and political changes, the advent of tourism, and the injection of foreign capital and businessmen into the area). Lack of knowledge about their rights under the current political dispensation, as well as the perceived need for mediation between themselves and foreign landowners, points to a general sense of powerlessness. Feelings of alienation from local government structures aimed at fulfilling this function indicate a significant gap between the statute at the national level and the local reality. Local reality is informed by a strong conservatism which is generated by African Independent Church structures and local Xhosa perceptions of manhood and respectability. This conservative discourse leads to a frame of reference which is largely informed by pre-1994 interactions with farmers and government. This results in a situation in which farm workers, largely unaware of their rights in the new dispensation, operate as they did in the past; waiting for landowners to decide their fate for them. What ensues is a lack of meaningful interaction with government and landowners, perpetuating their subjugation and cynicism as to whether government structures are in fact working in their interests. The thesis comes to three main conclusions. The first is that game farming has been negatively received by farm workers due to the associated threats of unemployment and eviction. The second is that despite high levels of subjugation, even the very poor are agents to some degree. The creation of a masculine identity which is internally articulated, as opposed to outwardly expressed, and the grounding of reputation in the family suggest that farm workers have developed mechanisms to deal with their disempowered position. Lastly, farm workers are in possession of social capital which has made it possible for them to deal with their low status in the societal hierarchy. This includes the Church, family and fellow community members. These coping strategies have however proved a disadvantage in the current era because they prevent direct communication with landowners, government and NGOs.
- Full Text:
- Date Issued: 2004
- Authors: Luck, Kelly
- Date: 2004
- Subjects: Game farms -- South Africa -- Eastern Cape , Agricultural laborers -- South Africa -- Eastern Cape -- Social conditions Agricultural laborers -- South Africa -- Eastern Cape -- Economic conditions Agricultural laborers -- Political aspects -- South Africa -- Eastern Cape Agricultural laborers -- Legal status, laws, etc. -- South Africa -- Eastern Cape Agricultural laborers -- Protection -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2104 , http://hdl.handle.net/10962/d1004144
- Description: This thesis is an investigation of the impact of commercial game farming on former farm workers in the Bushman's River area of the Eastern Cape. In its examination of the broader economic and political changes that have facilitated a move from agriculture to game farming, it analyses how these changes affect farm workers. The main concern of the thesis is the ways in which farm workers (at the local level) respond to changes at the national and global level (legal and political changes, the advent of tourism, and the injection of foreign capital and businessmen into the area). Lack of knowledge about their rights under the current political dispensation, as well as the perceived need for mediation between themselves and foreign landowners, points to a general sense of powerlessness. Feelings of alienation from local government structures aimed at fulfilling this function indicate a significant gap between the statute at the national level and the local reality. Local reality is informed by a strong conservatism which is generated by African Independent Church structures and local Xhosa perceptions of manhood and respectability. This conservative discourse leads to a frame of reference which is largely informed by pre-1994 interactions with farmers and government. This results in a situation in which farm workers, largely unaware of their rights in the new dispensation, operate as they did in the past; waiting for landowners to decide their fate for them. What ensues is a lack of meaningful interaction with government and landowners, perpetuating their subjugation and cynicism as to whether government structures are in fact working in their interests. The thesis comes to three main conclusions. The first is that game farming has been negatively received by farm workers due to the associated threats of unemployment and eviction. The second is that despite high levels of subjugation, even the very poor are agents to some degree. The creation of a masculine identity which is internally articulated, as opposed to outwardly expressed, and the grounding of reputation in the family suggest that farm workers have developed mechanisms to deal with their disempowered position. Lastly, farm workers are in possession of social capital which has made it possible for them to deal with their low status in the societal hierarchy. This includes the Church, family and fellow community members. These coping strategies have however proved a disadvantage in the current era because they prevent direct communication with landowners, government and NGOs.
- Full Text:
- Date Issued: 2004
Coping and satisfaction with life of retired elderly females in a residence for the aged
- Authors: Yerushalmi, Orit
- Date: 2004
- Subjects: Older women -- South Africa -- Port Elizabeth -- Attitudes , Old age homes -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11027 , http://hdl.handle.net/10948/383 , Older women -- South Africa -- Port Elizabeth -- Attitudes , Old age homes -- South Africa -- Port Elizabeth
- Description: Demographically the aged are the fastest growing group both world-wide and in South Africa but despite this, psychologists have neglected psycho-geriatric research and its importance. In the past, old age has been studied by psychologists as a deviation from the norm of youth. The primary focus has been on the rate of cognitive decline, the process of social withdrawal and the etiology of dementia. Although these issues are of significant importance, the positive aspects of aging should also be considered; thereby challenging the stereotype that old age means disengagement, decline and degeneration. This study aimed to explore and describe the coping and life satisfaction of the retired elderly females in a residence for the aged. A quantitative exploratory descriptive research design was employed, making use of non-probability convenience sampling. The sample consisted of 40 retired females who have been living in a residence for the aged for at least 12 months. Further inclusion criterions were that the participants should have a relatively "sound/stable" neuropsychological status (i.e., they should not be suffering from any clinically diagnosed disorders, for example, dementia and/or Alzheimer's disease). The Coping Resources Inventory (CRI) was utilized to identify the coping resources used by the participants; the Orientation to Life Questionnaire (SOC-29) was utilised as a measure of the participants' sense of coherence; the Life Satisfaction in the Elderly Scale (LSES) was employed to measure the global life satisfaction of the participants, namely on the cognitive level. A biographical questionnaire collated important demographic and background information. The data was analysed through computing descriptive statistics. Following this a Pearson product-moment correlation coefficient was utilised to inter-correlate the total score of the SOC-29 and the total score of the LSES with the individual subscales of the CRI. The results of the present study indicated the following: the SOC-29 revealed a relatively high mean score for the current sample. Results of the CRI revealed relatively high mean scores for the total scale as well as the five different subscales. The highest scores were obtained for the Spiritual/Philosophical and Physical Resources Subscales, while the lowest score was obtained for the Cognitive Resource Subscale. Results from the LSES indicated relatively high mean scores for both the total and all eight subscales. The highest scores were obtained for the Mood and xii Social contacts Subscales, while the lowest scores were obtained for the Health and Finance Subscales. Significant positive correlation was evident between the total scores of the CRI, the SOC-29 and the LSES. With regard to the individual subscales of the CRI, the results indicated significant moderate relationships between the SOC- 29 total raw score, the LSES total raw score and the Cognitive, Social and Physical Subscales scores of the CRI. However, the SOC-29 and LSES total raw scores did not correlate with the Emotional and Spiritual/Philosophical subscales of the CRI.
- Full Text:
- Date Issued: 2004
- Authors: Yerushalmi, Orit
- Date: 2004
- Subjects: Older women -- South Africa -- Port Elizabeth -- Attitudes , Old age homes -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11027 , http://hdl.handle.net/10948/383 , Older women -- South Africa -- Port Elizabeth -- Attitudes , Old age homes -- South Africa -- Port Elizabeth
- Description: Demographically the aged are the fastest growing group both world-wide and in South Africa but despite this, psychologists have neglected psycho-geriatric research and its importance. In the past, old age has been studied by psychologists as a deviation from the norm of youth. The primary focus has been on the rate of cognitive decline, the process of social withdrawal and the etiology of dementia. Although these issues are of significant importance, the positive aspects of aging should also be considered; thereby challenging the stereotype that old age means disengagement, decline and degeneration. This study aimed to explore and describe the coping and life satisfaction of the retired elderly females in a residence for the aged. A quantitative exploratory descriptive research design was employed, making use of non-probability convenience sampling. The sample consisted of 40 retired females who have been living in a residence for the aged for at least 12 months. Further inclusion criterions were that the participants should have a relatively "sound/stable" neuropsychological status (i.e., they should not be suffering from any clinically diagnosed disorders, for example, dementia and/or Alzheimer's disease). The Coping Resources Inventory (CRI) was utilized to identify the coping resources used by the participants; the Orientation to Life Questionnaire (SOC-29) was utilised as a measure of the participants' sense of coherence; the Life Satisfaction in the Elderly Scale (LSES) was employed to measure the global life satisfaction of the participants, namely on the cognitive level. A biographical questionnaire collated important demographic and background information. The data was analysed through computing descriptive statistics. Following this a Pearson product-moment correlation coefficient was utilised to inter-correlate the total score of the SOC-29 and the total score of the LSES with the individual subscales of the CRI. The results of the present study indicated the following: the SOC-29 revealed a relatively high mean score for the current sample. Results of the CRI revealed relatively high mean scores for the total scale as well as the five different subscales. The highest scores were obtained for the Spiritual/Philosophical and Physical Resources Subscales, while the lowest score was obtained for the Cognitive Resource Subscale. Results from the LSES indicated relatively high mean scores for both the total and all eight subscales. The highest scores were obtained for the Mood and xii Social contacts Subscales, while the lowest scores were obtained for the Health and Finance Subscales. Significant positive correlation was evident between the total scores of the CRI, the SOC-29 and the LSES. With regard to the individual subscales of the CRI, the results indicated significant moderate relationships between the SOC- 29 total raw score, the LSES total raw score and the Cognitive, Social and Physical Subscales scores of the CRI. However, the SOC-29 and LSES total raw scores did not correlate with the Emotional and Spiritual/Philosophical subscales of the CRI.
- Full Text:
- Date Issued: 2004
Coping resources and sense of coherence of male police officers in the South African Police Services
- Authors: Kayal, Mohammed
- Date: 2004
- Subjects: Police -- Job stress -- South Africa , South African Police Service , Coping Responses Inventory -- South Africa , Adjustment (Psychology) -- South Africa -- Testing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11018 , http://hdl.handle.net/10948/345 , Police -- Job stress -- South Africa , South African Police Service , Coping Responses Inventory -- South Africa , Adjustment (Psychology) -- South Africa -- Testing
- Description: In South Africa the extraordinary high levels of violence and crime, escalating execution and killings of police officers, large number of murders, hijacking, robberies and shootings have created an unusually dangerous and stressful working environment for the members of the South African Police Services (SAPS). An overview of the literature on the nature of work in the SAPS indicates that these working conditions might have a detrimental effect on the coping resources and sense of coherence of police officers. This study aimed to explore and describe the coping resources and sense of coherence of male police officers in the SAPS. It employed a quantitative exploratory descriptive research design, making use of non-probability convenience sampling. The sample consisted of 70 male police officers who have been in the service of the SAPS for at least two years. All police officers that were included in the sample were also shift workers defined by the SAPS as police officers who work unsociable hours and who are likely to be exposed to violence, risks, danger, and traumatic situations. A further inclusion criterion was that the police officers must not be subjected to possible relocation or transfer as stipulated in Resolution 7/2002. The Coping Resources Inventory (CRI) was employed to identify the coping resources used by the participants and the Sense of Coherence Questionnaire (SOC- 29) was utilised as a measure of the participants’ sense of coherence. A biographical questionnaire collated important demographic and background information. The data was analysed by computing descriptive statistics. To examine the relationship between the sense of coherence and coping resources of the participants, a multiple correlation xv between the total score of the SOC-29 and the subscales of the CRI was conducted. Following this, a Pearson product-moment correlation coefficient was utilised to intercorrelate the total score of the SOC-29 and the individual subscales of the CRI. The results of the present study indicated the followings: The SOC-29 revealed relatively low scores for the current sample. Results on the CRI revealed low average scores for both the total and all five scales. The correlational analysis revealed a significant positive relationship between the two measures for the current sample.
- Full Text:
Coping resources and sense of coherence of male police officers in the South African Police Services
- Authors: Kayal, Mohammed
- Date: 2004
- Subjects: Police -- Job stress -- South Africa , South African Police Service , Coping Responses Inventory -- South Africa , Adjustment (Psychology) -- South Africa -- Testing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:11018 , http://hdl.handle.net/10948/345 , Police -- Job stress -- South Africa , South African Police Service , Coping Responses Inventory -- South Africa , Adjustment (Psychology) -- South Africa -- Testing
- Description: In South Africa the extraordinary high levels of violence and crime, escalating execution and killings of police officers, large number of murders, hijacking, robberies and shootings have created an unusually dangerous and stressful working environment for the members of the South African Police Services (SAPS). An overview of the literature on the nature of work in the SAPS indicates that these working conditions might have a detrimental effect on the coping resources and sense of coherence of police officers. This study aimed to explore and describe the coping resources and sense of coherence of male police officers in the SAPS. It employed a quantitative exploratory descriptive research design, making use of non-probability convenience sampling. The sample consisted of 70 male police officers who have been in the service of the SAPS for at least two years. All police officers that were included in the sample were also shift workers defined by the SAPS as police officers who work unsociable hours and who are likely to be exposed to violence, risks, danger, and traumatic situations. A further inclusion criterion was that the police officers must not be subjected to possible relocation or transfer as stipulated in Resolution 7/2002. The Coping Resources Inventory (CRI) was employed to identify the coping resources used by the participants and the Sense of Coherence Questionnaire (SOC- 29) was utilised as a measure of the participants’ sense of coherence. A biographical questionnaire collated important demographic and background information. The data was analysed by computing descriptive statistics. To examine the relationship between the sense of coherence and coping resources of the participants, a multiple correlation xv between the total score of the SOC-29 and the subscales of the CRI was conducted. Following this, a Pearson product-moment correlation coefficient was utilised to intercorrelate the total score of the SOC-29 and the individual subscales of the CRI. The results of the present study indicated the followings: The SOC-29 revealed relatively low scores for the current sample. Results on the CRI revealed low average scores for both the total and all five scales. The correlational analysis revealed a significant positive relationship between the two measures for the current sample.
- Full Text:
Coping with change: an investigation into language policy and practice in three Port Elizabeth primary schools
- Authors: Foli, Cordelia Nokuthula
- Date: 2004
- Subjects: Language policy -- South Africa -- Port Elizabeth , Education, Primary -- South Africa -- Port Elizabeth , Multicultural education -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10995 , http://hdl.handle.net/10948/327 , Language policy -- South Africa -- Port Elizabeth , Education, Primary -- South Africa -- Port Elizabeth , Multicultural education -- South Africa -- Port Elizabeth
- Description: This is a qualitative case study of three Primary, schools in Port Elizabeth District.They are an ex -White, ex-Coloured and ex-Indian schools. These schools have become desegregated and are multicultural and multilingual. The medium of instruction in the schools is English. The study aims to show: Adaptations that teachers are making to make the curriculum accessible to children from diverse linguistic and cultural backgrounds; coping strategies that learners have needed to adapt when learning in a language that is not their mother tongue; attitudes of parents, teachers and pupils to the use of English and to the level at which the other home languages are offered as subjects. Another aim of the study is to document strategies and adaptations that teachers and learners have had to make in teaching and learning in multicultural and multilingual environments. Data was gathered through questionnaires, classroom observation, discussions with teachers, interviews with principals, parents and learners. The study concludes that two of the schools that were investigated have attempted to change school language policy. They have done this by introducing isiXhosa as one of the subjects in the curriculum. Contrary to the language policy which encourages maintenance of primary language, these learning contexts encourage the development of English to the detriment of isiXhosa. The issue that still needs to be addressed is the level at which isiXhosa primary language speakers are offered the language at school. This study further concludes that isiXhosa and Afrikaans speaking parents and learners in the English environments, value their primary languages for communicative purposes only in informal situations. English is valued as a language of access and for use as a language of learning and teaching. Finally, it is teachers in the Foundation Phase who seem to have needed to make a lot of adaptations and adjustments to accommodate non- native speakers of English in the classrooms.
- Full Text:
- Date Issued: 2004
- Authors: Foli, Cordelia Nokuthula
- Date: 2004
- Subjects: Language policy -- South Africa -- Port Elizabeth , Education, Primary -- South Africa -- Port Elizabeth , Multicultural education -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10995 , http://hdl.handle.net/10948/327 , Language policy -- South Africa -- Port Elizabeth , Education, Primary -- South Africa -- Port Elizabeth , Multicultural education -- South Africa -- Port Elizabeth
- Description: This is a qualitative case study of three Primary, schools in Port Elizabeth District.They are an ex -White, ex-Coloured and ex-Indian schools. These schools have become desegregated and are multicultural and multilingual. The medium of instruction in the schools is English. The study aims to show: Adaptations that teachers are making to make the curriculum accessible to children from diverse linguistic and cultural backgrounds; coping strategies that learners have needed to adapt when learning in a language that is not their mother tongue; attitudes of parents, teachers and pupils to the use of English and to the level at which the other home languages are offered as subjects. Another aim of the study is to document strategies and adaptations that teachers and learners have had to make in teaching and learning in multicultural and multilingual environments. Data was gathered through questionnaires, classroom observation, discussions with teachers, interviews with principals, parents and learners. The study concludes that two of the schools that were investigated have attempted to change school language policy. They have done this by introducing isiXhosa as one of the subjects in the curriculum. Contrary to the language policy which encourages maintenance of primary language, these learning contexts encourage the development of English to the detriment of isiXhosa. The issue that still needs to be addressed is the level at which isiXhosa primary language speakers are offered the language at school. This study further concludes that isiXhosa and Afrikaans speaking parents and learners in the English environments, value their primary languages for communicative purposes only in informal situations. English is valued as a language of access and for use as a language of learning and teaching. Finally, it is teachers in the Foundation Phase who seem to have needed to make a lot of adaptations and adjustments to accommodate non- native speakers of English in the classrooms.
- Full Text:
- Date Issued: 2004
CREWS : a Component-driven, Run-time Extensible Web Service framework
- Authors: Parry, Dominic Charles
- Date: 2004
- Subjects: Component software -- Development , Computer software -- Reusability , Software reengineering , Web services
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4628 , http://hdl.handle.net/10962/d1006501 , Component software -- Development , Computer software -- Reusability , Software reengineering , Web services
- Description: There has been an increased focus in recent years on the development of re-usable software, in the form of objects and software components. This increase, together with pressures from enterprises conducting transactions on the Web to support all business interactions on all scales, has encouraged research towards the development of easily reconfigurable and highly adaptable Web services. This work investigates the ability of Component-Based Software Development (CBSD) to produce such systems, and proposes a more manageable use of CBSD methodologies. Component-Driven Software Development (CDSD) is introduced to enable better component manageability. Current Web service technologies are also examined to determine their ability to support extensible Web services, and a dynamic Web service architecture is proposed. The work also describes the development of two proof-of-concept systems, DREW Chat and Hamilton Bank. DREW Chat and Hamilton Bank are implementations of Web services that support extension dynamically and at run-time. DREW Chat is implemented on the client side, where the user is given the ability to change the client as required. Hamilton Bank is a server-side implementation, which is run-time customisable by both the user and the party offering the service. In each case, a generic architecture is produced to support dynamic Web services. These architectures are combined to produce CREWS, a Component-driven Runtime Extensible Web Service solution that enables Web services to support the ever changing needs of enterprises. A discussion of similar work is presented, identifying the strengths and weaknesses of our architecture when compared to other solutions.
- Full Text:
- Date Issued: 2004
- Authors: Parry, Dominic Charles
- Date: 2004
- Subjects: Component software -- Development , Computer software -- Reusability , Software reengineering , Web services
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4628 , http://hdl.handle.net/10962/d1006501 , Component software -- Development , Computer software -- Reusability , Software reengineering , Web services
- Description: There has been an increased focus in recent years on the development of re-usable software, in the form of objects and software components. This increase, together with pressures from enterprises conducting transactions on the Web to support all business interactions on all scales, has encouraged research towards the development of easily reconfigurable and highly adaptable Web services. This work investigates the ability of Component-Based Software Development (CBSD) to produce such systems, and proposes a more manageable use of CBSD methodologies. Component-Driven Software Development (CDSD) is introduced to enable better component manageability. Current Web service technologies are also examined to determine their ability to support extensible Web services, and a dynamic Web service architecture is proposed. The work also describes the development of two proof-of-concept systems, DREW Chat and Hamilton Bank. DREW Chat and Hamilton Bank are implementations of Web services that support extension dynamically and at run-time. DREW Chat is implemented on the client side, where the user is given the ability to change the client as required. Hamilton Bank is a server-side implementation, which is run-time customisable by both the user and the party offering the service. In each case, a generic architecture is produced to support dynamic Web services. These architectures are combined to produce CREWS, a Component-driven Runtime Extensible Web Service solution that enables Web services to support the ever changing needs of enterprises. A discussion of similar work is presented, identifying the strengths and weaknesses of our architecture when compared to other solutions.
- Full Text:
- Date Issued: 2004
Decryption of Wire-level Network Protocols for Forensic Inspection
- Authors: Irwin, Barry V W
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428339 , vital:72504 , https://www.researchgate.net/profile/Barry-Irwin/publication/327622612_Decryption_of_Wire-lev-el_Network_Protocols_for_Forensic_Inspection/links/5b9a1220299bf14ad4d6a3b1/Decryption-of-Wire-level-Network-Protocols-for-Forensic-Inspection.pdf
- Description: With the increased use of encrypted transport protocols, the problem of debugging and monitoring the contents of these protocols has in-creased in complexity. This work proposes the development of a unified means of access to the plaintext, through the use of privileged access to the encryption keys, based on the assumption that an administrator has legitimate access to one side of a communication, and is thereby able to gain access to the encryption tokens.
- Full Text:
- Date Issued: 2004
- Authors: Irwin, Barry V W
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428339 , vital:72504 , https://www.researchgate.net/profile/Barry-Irwin/publication/327622612_Decryption_of_Wire-lev-el_Network_Protocols_for_Forensic_Inspection/links/5b9a1220299bf14ad4d6a3b1/Decryption-of-Wire-level-Network-Protocols-for-Forensic-Inspection.pdf
- Description: With the increased use of encrypted transport protocols, the problem of debugging and monitoring the contents of these protocols has in-creased in complexity. This work proposes the development of a unified means of access to the plaintext, through the use of privileged access to the encryption keys, based on the assumption that an administrator has legitimate access to one side of a communication, and is thereby able to gain access to the encryption tokens.
- Full Text:
- Date Issued: 2004
Design and evaluation of a new pharmaceutical pictogram sequence to convey medicine usage
- Mansoor, Leila E, Dowse, Roslind
- Authors: Mansoor, Leila E , Dowse, Roslind
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6402 , http://hdl.handle.net/10962/d1006338
- Description: Pictorials may be used to augment textual instructions in the depiction of safety and warning information on medicines. The objective of this study was to design, develop and evaluate a simple and culturally appropriate pictogram sequence for using nystatin suspension, and to assess its understandability in low-literate Xhosa participants. A new pharmaceutical pictogram sequence was designed through focus group discussions and evaluated in a 2-phase process. The results of Phase 1 (30 participants) identified various problems associated with the new pictogram sequence. It was modified accordingly and re-evaluated in Phase 2 with 20 participants. All participants belonged to the Xhosa group, had between 0 and 7 years of formal schooling and had English as their second language. Acceptance of the new pictogram sequence was based on international standards (ANSI and ISO criterion) for evaluating the comprehensibility of pictograms. In Phase 1, the new pictogram sequence was correctly interpreted by 66.7% of the participants and this complied with the ISO criterion of 67% correct. In Phase 2, 95% of the participants were able to correctly interpret the new pictogram sequence. This result complied with the ANSI criterion of 85% correct, therefore, this new pictogram sequence was considered to be acceptable. This study has illustrated the success of using a consultative approach in the design of new pictograms.
- Full Text:
- Date Issued: 2004
- Authors: Mansoor, Leila E , Dowse, Roslind
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6402 , http://hdl.handle.net/10962/d1006338
- Description: Pictorials may be used to augment textual instructions in the depiction of safety and warning information on medicines. The objective of this study was to design, develop and evaluate a simple and culturally appropriate pictogram sequence for using nystatin suspension, and to assess its understandability in low-literate Xhosa participants. A new pharmaceutical pictogram sequence was designed through focus group discussions and evaluated in a 2-phase process. The results of Phase 1 (30 participants) identified various problems associated with the new pictogram sequence. It was modified accordingly and re-evaluated in Phase 2 with 20 participants. All participants belonged to the Xhosa group, had between 0 and 7 years of formal schooling and had English as their second language. Acceptance of the new pictogram sequence was based on international standards (ANSI and ISO criterion) for evaluating the comprehensibility of pictograms. In Phase 1, the new pictogram sequence was correctly interpreted by 66.7% of the participants and this complied with the ISO criterion of 67% correct. In Phase 2, 95% of the participants were able to correctly interpret the new pictogram sequence. This result complied with the ANSI criterion of 85% correct, therefore, this new pictogram sequence was considered to be acceptable. This study has illustrated the success of using a consultative approach in the design of new pictograms.
- Full Text:
- Date Issued: 2004
Design and implementation of robotic control for industrial applications
- Authors: Will, Desmond Jeffrey
- Date: 2004
- Subjects: Robotics
- Language: English
- Type: Thesis , Masters , MTech (Electrical Engineering)
- Identifier: vital:10819 , http://hdl.handle.net/10948/213 , Robotics
- Description: Background: With the pressing need for increased productivity and delivery of end products of uniform quality, industry is turning more and more to computer-based automation. At the present time, most of industrial automated manufacturing is carried out by specialpurpose machines, designed to perform specific functions in a manufacturing process. The inflexibility and generally high cost of these machines often referred to as hard automation systems, have led to a broad-based interest in the use of robots capable of performing a variety of manufacturing functions in a more flexible working environment and at lower production costs. A robot is a reprogrammable general-purpose manipulator with external sensors that can perform various assembly tasks. A robot may possess intelligence, which is normally due to computer algorithms associated with its controls and sensing systems. Industrial robots are general-purpose, computer-controlled manipulators consisting of several rigid links connected in series by revolute or prismatic joints. Most of today’s industrial robots, though controlled by mini and microcomputers are basically simple positional machines. They execute a given task by playing back a prerecorded or preprogrammed sequence of motion that has been previously guided or taught by the hand-held control teach box. Moreover, these robots are equipped with little or no external sensors for obtaining the information vital to its working environment. As a result robots are used mainly for relatively simple, repetitive tasks. More research effort has been directed in sensory feedback systems, which has resulted in improving the overall performance of the manipulator system. An example of a sensory feedback system would be: a vision Charge-Coupled Device (CCD) system. This can be utilized to manipulate the robot position dependant on the surrounding robot environment (various object profile sizes). This vision system can only be used within the robot movement envelope
- Full Text:
- Date Issued: 2004
- Authors: Will, Desmond Jeffrey
- Date: 2004
- Subjects: Robotics
- Language: English
- Type: Thesis , Masters , MTech (Electrical Engineering)
- Identifier: vital:10819 , http://hdl.handle.net/10948/213 , Robotics
- Description: Background: With the pressing need for increased productivity and delivery of end products of uniform quality, industry is turning more and more to computer-based automation. At the present time, most of industrial automated manufacturing is carried out by specialpurpose machines, designed to perform specific functions in a manufacturing process. The inflexibility and generally high cost of these machines often referred to as hard automation systems, have led to a broad-based interest in the use of robots capable of performing a variety of manufacturing functions in a more flexible working environment and at lower production costs. A robot is a reprogrammable general-purpose manipulator with external sensors that can perform various assembly tasks. A robot may possess intelligence, which is normally due to computer algorithms associated with its controls and sensing systems. Industrial robots are general-purpose, computer-controlled manipulators consisting of several rigid links connected in series by revolute or prismatic joints. Most of today’s industrial robots, though controlled by mini and microcomputers are basically simple positional machines. They execute a given task by playing back a prerecorded or preprogrammed sequence of motion that has been previously guided or taught by the hand-held control teach box. Moreover, these robots are equipped with little or no external sensors for obtaining the information vital to its working environment. As a result robots are used mainly for relatively simple, repetitive tasks. More research effort has been directed in sensory feedback systems, which has resulted in improving the overall performance of the manipulator system. An example of a sensory feedback system would be: a vision Charge-Coupled Device (CCD) system. This can be utilized to manipulate the robot position dependant on the surrounding robot environment (various object profile sizes). This vision system can only be used within the robot movement envelope
- Full Text:
- Date Issued: 2004
Design of a performance evaluation tool for multimedia databases with special reference to Oracle
- Authors: Stakemire, Tonia
- Date: 2004
- Subjects: Oracle (Computer file) , Application software -- Evaluation , Database management -- Evaluation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4705 , http://hdl.handle.net/10962/d1015975
- Description: Increased production and use of multimedia data has led to the development of a more advanced Database Management System (DBMS), like an Object Relational Database Management System (ORDBMS). These advanced databases are necessitated by the complexity in structure and the functionality required by multimedia data. Unfortunately, no suitable benchmarks exist with which to test the performance of databases when handling multimedia data. This thesis describes the design of a benchmark to measure the performance of basic functionality found in multimedia databases. The benchmark, called MORD (Multimedia Object Relational Databases), targets Oracle, a well known commercial Object Relational Database Management System (ORDBMS) that can handle multimedia data. Although MORD targets Oracle, it can easily be applied to other Multimedia Database Management System (MMDBMS) as a result of a design that stressed its portability, and simplicity. MORD consists of a database schema, test data, and code to simulate representative queries on multimedia databases. A number of experiments are described that validate MORD and ensure its correct design and that its objectives are met. A by-product of these experiments is an initial understanding of the performance of multimedia databases. The experiments show that with multimedia data the buffer cache should be at least large enough to hold the largest dataset, a bigger block size improves the performance, and turning off logging and caching for bulk loading improves the performance. MORD can be used to compare different ORDBMS or to assist in the configuration of a specific database.
- Full Text:
- Date Issued: 2004
- Authors: Stakemire, Tonia
- Date: 2004
- Subjects: Oracle (Computer file) , Application software -- Evaluation , Database management -- Evaluation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4705 , http://hdl.handle.net/10962/d1015975
- Description: Increased production and use of multimedia data has led to the development of a more advanced Database Management System (DBMS), like an Object Relational Database Management System (ORDBMS). These advanced databases are necessitated by the complexity in structure and the functionality required by multimedia data. Unfortunately, no suitable benchmarks exist with which to test the performance of databases when handling multimedia data. This thesis describes the design of a benchmark to measure the performance of basic functionality found in multimedia databases. The benchmark, called MORD (Multimedia Object Relational Databases), targets Oracle, a well known commercial Object Relational Database Management System (ORDBMS) that can handle multimedia data. Although MORD targets Oracle, it can easily be applied to other Multimedia Database Management System (MMDBMS) as a result of a design that stressed its portability, and simplicity. MORD consists of a database schema, test data, and code to simulate representative queries on multimedia databases. A number of experiments are described that validate MORD and ensure its correct design and that its objectives are met. A by-product of these experiments is an initial understanding of the performance of multimedia databases. The experiments show that with multimedia data the buffer cache should be at least large enough to hold the largest dataset, a bigger block size improves the performance, and turning off logging and caching for bulk loading improves the performance. MORD can be used to compare different ORDBMS or to assist in the configuration of a specific database.
- Full Text:
- Date Issued: 2004
Designing an evaluation instrument for South African intermediate phase school textbooks
- Authors: Vosloo, Barend Jacobus
- Date: 2004
- Subjects: Textbooks -- South Africa -- Evaluation , Curriculum change -- South Africa -- Evaluation
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:11014 , http://hdl.handle.net/10948/324 , Textbooks -- South Africa -- Evaluation , Curriculum change -- South Africa -- Evaluation
- Description: No coherent theory about the practice of South African intermediate phase school textbook evaluation has been forthcoming since the advent of a new South African school curriculum in 1998. This deficiency has had an adverse effect on the quality of intermediate phase school textbooks, as well as on the capacity to assess their value. This research project, therefore, had two aims. The first was to articulate a theory about the practice of textbook evaluation. The second was to develop a procedure for evaluating South African intermediate phase school textbooks in terms of the theory. The research method was underpinned by the interpretive research paradigm in terms of which relevant data were analysed and interpreted. The data emanated from a literature review, an analysis of the national Department of Education’s Revised National Curriculum Statement and its draft policy for the evaluation of learning support material, and two surveys. The first survey comprised a sample of intermediate phase teachers and the second a sample of intermediate phase textbook authors. Sufficient evidence was found to conclude that the capabilities of the authoring team, the authors’ rationale and their observance of the process of learning and instruction, the accessibility of the textbook, the availability of teacher support, meeting the requirements of the Revised National Curriculum Statement, and certain key notions about textbook evaluation play a role in articulating a theory about textbook evaluation in order to guide the process of determining the effectiveness of South African intermediate phase school textbooks. Based on the above-mentioned theory, this study proposes a procedure to assist teachers and textbook evaluators to assess the worth of South African intermediate phase school textbooks in a brief, systematic, thorough, rigorous, and practical manner.
- Full Text:
- Date Issued: 2004
- Authors: Vosloo, Barend Jacobus
- Date: 2004
- Subjects: Textbooks -- South Africa -- Evaluation , Curriculum change -- South Africa -- Evaluation
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:11014 , http://hdl.handle.net/10948/324 , Textbooks -- South Africa -- Evaluation , Curriculum change -- South Africa -- Evaluation
- Description: No coherent theory about the practice of South African intermediate phase school textbook evaluation has been forthcoming since the advent of a new South African school curriculum in 1998. This deficiency has had an adverse effect on the quality of intermediate phase school textbooks, as well as on the capacity to assess their value. This research project, therefore, had two aims. The first was to articulate a theory about the practice of textbook evaluation. The second was to develop a procedure for evaluating South African intermediate phase school textbooks in terms of the theory. The research method was underpinned by the interpretive research paradigm in terms of which relevant data were analysed and interpreted. The data emanated from a literature review, an analysis of the national Department of Education’s Revised National Curriculum Statement and its draft policy for the evaluation of learning support material, and two surveys. The first survey comprised a sample of intermediate phase teachers and the second a sample of intermediate phase textbook authors. Sufficient evidence was found to conclude that the capabilities of the authoring team, the authors’ rationale and their observance of the process of learning and instruction, the accessibility of the textbook, the availability of teacher support, meeting the requirements of the Revised National Curriculum Statement, and certain key notions about textbook evaluation play a role in articulating a theory about textbook evaluation in order to guide the process of determining the effectiveness of South African intermediate phase school textbooks. Based on the above-mentioned theory, this study proposes a procedure to assist teachers and textbook evaluators to assess the worth of South African intermediate phase school textbooks in a brief, systematic, thorough, rigorous, and practical manner.
- Full Text:
- Date Issued: 2004
Determination of 2′, 3′-Dideoxyinosine Using Iron (II) Phthalocyanine Modified Carbon Paste Electrode
- Ozoemena, Kenneth I, Stefan, Raluca-Ioana, Nyokong, Tebello
- Authors: Ozoemena, Kenneth I , Stefan, Raluca-Ioana , Nyokong, Tebello
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300298 , vital:57914 , xlink:href="https://doi.org/10.1081/AL-200031940"
- Description: An amperometric sensor, based on carbon paste impregnated with iron (II) phthalocyanine complex (FePc), has been constructed for the assay of anti‐HIV agent dideoxyinosine (didanosine, DDI). Using chronoamperometry (E = +1.04 V versus Ag/AgCl) technique, the amperometric sensor can be used reliably for dideoxyinosine assay at pH 7.4 phosphate buffer in the 1.5–9.5 nmol/L concentration range with a detection limit of 5.7 × 10−10 mol/L. The surface of the electrode can easily be regenerated by simple polishing, obtaining a fresh surface ready for use in a new assay. The new amperometric sensor proved to be highly reliable for the assay of dideoxyinosine purity in raw material as well as for the uniformity content test of Videx® tablets.
- Full Text:
- Date Issued: 2004
- Authors: Ozoemena, Kenneth I , Stefan, Raluca-Ioana , Nyokong, Tebello
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300298 , vital:57914 , xlink:href="https://doi.org/10.1081/AL-200031940"
- Description: An amperometric sensor, based on carbon paste impregnated with iron (II) phthalocyanine complex (FePc), has been constructed for the assay of anti‐HIV agent dideoxyinosine (didanosine, DDI). Using chronoamperometry (E = +1.04 V versus Ag/AgCl) technique, the amperometric sensor can be used reliably for dideoxyinosine assay at pH 7.4 phosphate buffer in the 1.5–9.5 nmol/L concentration range with a detection limit of 5.7 × 10−10 mol/L. The surface of the electrode can easily be regenerated by simple polishing, obtaining a fresh surface ready for use in a new assay. The new amperometric sensor proved to be highly reliable for the assay of dideoxyinosine purity in raw material as well as for the uniformity content test of Videx® tablets.
- Full Text:
- Date Issued: 2004
Determining the elements of the operations management transformation model for the monitoring and breaching of the Great Brak River Mouth system
- Authors: Kriel, J F
- Date: 2004
- Subjects: Rivers -- Management -- South Africa , Stream conservation -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10935 , http://hdl.handle.net/10948/214 , Rivers -- Management -- South Africa , Stream conservation -- South Africa
- Description: The prime challenge to those responsible for the management of South Africa’s estuaries is to maintain their viability in the face of ever increasing pressures. It is important that we learn to appreciate the value of estuaries and that we act wisely to manage them for sustainable use. Any operation must have the adequate resources to perform the duties and the correct processes must be followed. The purpose of this research is to determine whether the current inputs and processes needed for the monitoring and breaching of the Great Brak River Mouth system are sufficient to adhere to the output objectives of a healthy estuary together with safeguarding of properties. The research methodology for this study comprised the following steps: Firstly, a literature study was performed to identify the key elements of the operation management transformation model. Operations management deals with the output of any business, in other words the conversion of inputs to create certain outputs and they do this by a process of transformation. Secondly, extensive literature study was performed in order to access material regarding effective estuary and river mouth management. Thirdly, the current situation at Great Brak was assessed to determine whether the current inputs and processes are in place and if additional or altered inputs and processes are needed.
- Full Text:
- Date Issued: 2004
- Authors: Kriel, J F
- Date: 2004
- Subjects: Rivers -- Management -- South Africa , Stream conservation -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10935 , http://hdl.handle.net/10948/214 , Rivers -- Management -- South Africa , Stream conservation -- South Africa
- Description: The prime challenge to those responsible for the management of South Africa’s estuaries is to maintain their viability in the face of ever increasing pressures. It is important that we learn to appreciate the value of estuaries and that we act wisely to manage them for sustainable use. Any operation must have the adequate resources to perform the duties and the correct processes must be followed. The purpose of this research is to determine whether the current inputs and processes needed for the monitoring and breaching of the Great Brak River Mouth system are sufficient to adhere to the output objectives of a healthy estuary together with safeguarding of properties. The research methodology for this study comprised the following steps: Firstly, a literature study was performed to identify the key elements of the operation management transformation model. Operations management deals with the output of any business, in other words the conversion of inputs to create certain outputs and they do this by a process of transformation. Secondly, extensive literature study was performed in order to access material regarding effective estuary and river mouth management. Thirdly, the current situation at Great Brak was assessed to determine whether the current inputs and processes are in place and if additional or altered inputs and processes are needed.
- Full Text:
- Date Issued: 2004