Antibacterial properties of the methanol extract of helichrysum pedunculatum
- Authors: Ncube, Nqobile S
- Date: 2008
- Subjects: Medicinal plants , Methanol , Helichrysum
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11241 , http://hdl.handle.net/10353/461 , Medicinal plants , Methanol , Helichrysum
- Description: The methanol extract of Helichrisum pedunculatum was screened for antimicrobial activity up to a concentration of 5 mg/ml using the agar dilution technique. A number of test bacterial isolates, comprising both Gram negative and Gram positive organisms were susceptible to the crude extract of the plant. The minimum inhibitory concentrations (MICs) of the extract ranged between 1 and 5 mg/ml for the susceptible organisms. The MICs of the selected antibiotics, chloramphenicol and penicillin, ranged between 2 and 4 mg/L, and 2 and 32 mg/L respectively against Bacillus cereus, Proteus vulgaris and Staphylococcus aureus OKOH1. Bactericidal activity was determined by the time kill assay. The methanol extract of the plant was not bactericidal at 1 × MIC for B. cereus, P. vulgaris and Staph. aureus OKOH1. At 2 × MIC the extract was bacteriostatic against B. cereus but bactericidal against P. vulgaris and Staph. aureus OKOH1. Combination studies were done at 1/2 × MIC, 1 × MIC and 2 × MIC of the plant extract with 1 × MIC of the antibiotics. Combinations of the plant extract and chloramphenicol resulted in mostly indifferent interactions against P. vulgaris and Staph. aureus OKOH1 but synergistic interactions at higher concentration of the plant extract for B. cereus. Penicillin combinations gave synergistic interactions at lower concentrations of the plant for P.vulgaris and Staph. aureus OKOH1 but was mostly indifferent for B. cereus.
- Full Text:
- Date Issued: 2008
- Authors: Ncube, Nqobile S
- Date: 2008
- Subjects: Medicinal plants , Methanol , Helichrysum
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11241 , http://hdl.handle.net/10353/461 , Medicinal plants , Methanol , Helichrysum
- Description: The methanol extract of Helichrisum pedunculatum was screened for antimicrobial activity up to a concentration of 5 mg/ml using the agar dilution technique. A number of test bacterial isolates, comprising both Gram negative and Gram positive organisms were susceptible to the crude extract of the plant. The minimum inhibitory concentrations (MICs) of the extract ranged between 1 and 5 mg/ml for the susceptible organisms. The MICs of the selected antibiotics, chloramphenicol and penicillin, ranged between 2 and 4 mg/L, and 2 and 32 mg/L respectively against Bacillus cereus, Proteus vulgaris and Staphylococcus aureus OKOH1. Bactericidal activity was determined by the time kill assay. The methanol extract of the plant was not bactericidal at 1 × MIC for B. cereus, P. vulgaris and Staph. aureus OKOH1. At 2 × MIC the extract was bacteriostatic against B. cereus but bactericidal against P. vulgaris and Staph. aureus OKOH1. Combination studies were done at 1/2 × MIC, 1 × MIC and 2 × MIC of the plant extract with 1 × MIC of the antibiotics. Combinations of the plant extract and chloramphenicol resulted in mostly indifferent interactions against P. vulgaris and Staph. aureus OKOH1 but synergistic interactions at higher concentration of the plant extract for B. cereus. Penicillin combinations gave synergistic interactions at lower concentrations of the plant for P.vulgaris and Staph. aureus OKOH1 but was mostly indifferent for B. cereus.
- Full Text:
- Date Issued: 2008
An analysis of the influence of question design on pupils' approaches to number pattern generalisation tasks
- Authors: Samson, Duncan Alistair
- Date: 2008
- Subjects: Mathematics -- Study and teaching Number theory -- Problems, exercises, etc Algebra -- Study and teaching Arithmetic -- Foundations Pattern perception
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1421 , http://hdl.handle.net/10962/d1003302
- Description: This study is based on a qualitative investigation framed within an interpretive paradigm, and aims to investigate the extent to which question design affects the solution strategies adopted by children when solving linear number pattern generalisation tasks presented in pictorial and numeric contexts. The research tool comprised a series of 22 pencil and paper exercises based on linear generalisation tasks set in both numeric and 2-dimensional pictorial contexts. The responses to these linear generalisation questions were classified by means of stage descriptors as well as stage modifiers. The method or strategy adopted was carefully analysed and classified into one of seven categories. A meta-analysis focused on the formula derived for the nth term in conjunction with its justification. The process of justification proved to be a critical factor in being able to accurately interpret the origin of the sub-structure evident in many of these responses. From a theoretical perspective, the central role of justification/proof within the context of this study is seen as communication of mathematical understanding, and the process of justification/proof proved to be highly successful in providing a window of understanding into each pupil’s cognitive reasoning. The results of this study strongly support the notion that question design can play a critical role in influencing pupils’ choice of strategy and level of attainment when solving pattern generalisation tasks. Furthermore, this study identified a diverse range of visually motivated strategies and mechanisms of visualisation. An awareness and appreciation for such a diversity of visualisation strategies, as well as an understanding of the importance of appropriate question design, has direct pedagogical application within the context of the mathematics classroom.
- Full Text:
- Date Issued: 2008
- Authors: Samson, Duncan Alistair
- Date: 2008
- Subjects: Mathematics -- Study and teaching Number theory -- Problems, exercises, etc Algebra -- Study and teaching Arithmetic -- Foundations Pattern perception
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1421 , http://hdl.handle.net/10962/d1003302
- Description: This study is based on a qualitative investigation framed within an interpretive paradigm, and aims to investigate the extent to which question design affects the solution strategies adopted by children when solving linear number pattern generalisation tasks presented in pictorial and numeric contexts. The research tool comprised a series of 22 pencil and paper exercises based on linear generalisation tasks set in both numeric and 2-dimensional pictorial contexts. The responses to these linear generalisation questions were classified by means of stage descriptors as well as stage modifiers. The method or strategy adopted was carefully analysed and classified into one of seven categories. A meta-analysis focused on the formula derived for the nth term in conjunction with its justification. The process of justification proved to be a critical factor in being able to accurately interpret the origin of the sub-structure evident in many of these responses. From a theoretical perspective, the central role of justification/proof within the context of this study is seen as communication of mathematical understanding, and the process of justification/proof proved to be highly successful in providing a window of understanding into each pupil’s cognitive reasoning. The results of this study strongly support the notion that question design can play a critical role in influencing pupils’ choice of strategy and level of attainment when solving pattern generalisation tasks. Furthermore, this study identified a diverse range of visually motivated strategies and mechanisms of visualisation. An awareness and appreciation for such a diversity of visualisation strategies, as well as an understanding of the importance of appropriate question design, has direct pedagogical application within the context of the mathematics classroom.
- Full Text:
- Date Issued: 2008
Communal production systems of goats raised by resource-poor farmers in the Eastern Cape Province of South Africa
- Authors: Gwaze, Francisca Rumosa
- Date: 2008
- Subjects: Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Commons -- South Africa -- Eastern Cape , Pastoral systems -- Economic aspects -- South Africa -- Eastern Cape , Goats -- Economic aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Animal Science)
- Identifier: vital:11578 , http://hdl.handle.net/10353/172 , Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Commons -- South Africa -- Eastern Cape , Pastoral systems -- Economic aspects -- South Africa -- Eastern Cape , Goats -- Economic aspects -- South Africa -- Eastern Cape
- Description: Goats significantly contribute towards the subsistence, economic and social livelihoods of many resource-poor farmers in developing countries, the majority of which own goats. There, however, is dearth of information on communal goat production potential and roles to the rural populace. The broad objective of the study was to evaluate production practices, constraints, production efficiency and to determine nutritional and health status of goats raised by resource-poor communal farmers in the Eastern Cape Province of South Africa. Roles and management systems of goats, goat flock dynamics and, prevalence and loads of gastrointestinal infections and the nutritional status of goats in the study areas were determined. The relationships among body weight, body condition score, faecal egg counts and, haematological and biochemical profiles were also determined. Mean goat flock sizes per household were similar between the two districts studied; Amatole (14.0 ± 0.31) and Alfred Nzo (14.1 ± 1.42). Seventy-nine percent of households in Amatole and 78% in Alfred Nzo kept goats for ceremonies, such as the initiation ceremonies. Goat houses in the two districts were poorly constructed. Thirty two percent of farmers in Alfred Nzo district and 27% in Amatole district reported low buck to doe ratios, suggesting that inbreeding might have been reducing productivity of their flocks. Kid mortality had two major peaks; in May (21%) and in September (21%). Goat production potential (GPP), the proportion of mature and growing goats to the total flock size, was affected by gender of owner of goats. Goats owned by female had a significantly lower GPP value of 0.63 ± 0.015 than goats owned by male farmers (0.70 ± 0.010). Month also significantly affected GPP with the highest (P < 0.05) GPP recorded in May, June and July and the lowest in March and April. Village affected GPP with values for Nkosana and Qawukeni being significantly higher than for Mankone. Goat production potential was also higher (P < 0.05) in small flocks (0.04 ± 0.008) than in large flocks (0.02 ± 0.008). Goat production efficiency (GPE) ranged from 0.11 ± 0.193 in April to 1.55 ± 0.193 in December. The most prevalent gastrointestinal eggs were the strongyle egg type (68.4 ± 8.49 in Qawukeni and 96.1 ± 12.01 in Nkosana) followed by coccidia (53.3 ± 8.76 in Qawukeni and 68.8 ± 8.00 in Mankone). The other identified nematodes were Strongyloides and Trichostrongylus egg types. The trematodes observed were Fasciola and Paramphistomum species. High loads of strongyle eggs were observed in the hot-wet season and the post-rainy season, whilst the other egg types showed a peak in the hot-wet season only. For most of the gastrointestinal parasite eggs, prevalence was higher (P < 0.05) in the sour rangeland compared to the sweet rangeland. Higher (P < 0.05) levels of total protein (TP), globulin, aspartate aminotransferase (AST) and creatinine kinase (CK) levels were recorded in the wet than in the dry season. Body condition scores were positively correlated (P < 0.05) to albumin, body weight and packed cell volume. However, body condition scores were negatively correlated to TP, glucose, alanine transaminase (ALT) and AST. Strongyle egg loads were positively correlated to FAMACHA scores, packed cell volume, body weight and body condition score. The observed high globulin levels suggested a chronic health challenge. Thus, it is fundamental to devise affordable interventions for the control of gastrointestinal parasites in communal goats leading to improved goat productivity and hence rural livelihood
- Full Text:
- Date Issued: 2008
- Authors: Gwaze, Francisca Rumosa
- Date: 2008
- Subjects: Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Commons -- South Africa -- Eastern Cape , Pastoral systems -- Economic aspects -- South Africa -- Eastern Cape , Goats -- Economic aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Animal Science)
- Identifier: vital:11578 , http://hdl.handle.net/10353/172 , Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Commons -- South Africa -- Eastern Cape , Pastoral systems -- Economic aspects -- South Africa -- Eastern Cape , Goats -- Economic aspects -- South Africa -- Eastern Cape
- Description: Goats significantly contribute towards the subsistence, economic and social livelihoods of many resource-poor farmers in developing countries, the majority of which own goats. There, however, is dearth of information on communal goat production potential and roles to the rural populace. The broad objective of the study was to evaluate production practices, constraints, production efficiency and to determine nutritional and health status of goats raised by resource-poor communal farmers in the Eastern Cape Province of South Africa. Roles and management systems of goats, goat flock dynamics and, prevalence and loads of gastrointestinal infections and the nutritional status of goats in the study areas were determined. The relationships among body weight, body condition score, faecal egg counts and, haematological and biochemical profiles were also determined. Mean goat flock sizes per household were similar between the two districts studied; Amatole (14.0 ± 0.31) and Alfred Nzo (14.1 ± 1.42). Seventy-nine percent of households in Amatole and 78% in Alfred Nzo kept goats for ceremonies, such as the initiation ceremonies. Goat houses in the two districts were poorly constructed. Thirty two percent of farmers in Alfred Nzo district and 27% in Amatole district reported low buck to doe ratios, suggesting that inbreeding might have been reducing productivity of their flocks. Kid mortality had two major peaks; in May (21%) and in September (21%). Goat production potential (GPP), the proportion of mature and growing goats to the total flock size, was affected by gender of owner of goats. Goats owned by female had a significantly lower GPP value of 0.63 ± 0.015 than goats owned by male farmers (0.70 ± 0.010). Month also significantly affected GPP with the highest (P < 0.05) GPP recorded in May, June and July and the lowest in March and April. Village affected GPP with values for Nkosana and Qawukeni being significantly higher than for Mankone. Goat production potential was also higher (P < 0.05) in small flocks (0.04 ± 0.008) than in large flocks (0.02 ± 0.008). Goat production efficiency (GPE) ranged from 0.11 ± 0.193 in April to 1.55 ± 0.193 in December. The most prevalent gastrointestinal eggs were the strongyle egg type (68.4 ± 8.49 in Qawukeni and 96.1 ± 12.01 in Nkosana) followed by coccidia (53.3 ± 8.76 in Qawukeni and 68.8 ± 8.00 in Mankone). The other identified nematodes were Strongyloides and Trichostrongylus egg types. The trematodes observed were Fasciola and Paramphistomum species. High loads of strongyle eggs were observed in the hot-wet season and the post-rainy season, whilst the other egg types showed a peak in the hot-wet season only. For most of the gastrointestinal parasite eggs, prevalence was higher (P < 0.05) in the sour rangeland compared to the sweet rangeland. Higher (P < 0.05) levels of total protein (TP), globulin, aspartate aminotransferase (AST) and creatinine kinase (CK) levels were recorded in the wet than in the dry season. Body condition scores were positively correlated (P < 0.05) to albumin, body weight and packed cell volume. However, body condition scores were negatively correlated to TP, glucose, alanine transaminase (ALT) and AST. Strongyle egg loads were positively correlated to FAMACHA scores, packed cell volume, body weight and body condition score. The observed high globulin levels suggested a chronic health challenge. Thus, it is fundamental to devise affordable interventions for the control of gastrointestinal parasites in communal goats leading to improved goat productivity and hence rural livelihood
- Full Text:
- Date Issued: 2008
Application of the Baylis-Hillman methodology in the construction of novel heterocyclic derivatives
- Authors: Nyoni, Dubekile
- Date: 2008
- Subjects: Heterocyclic compounds -- Derivatives
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4402 , http://hdl.handle.net/10962/d1006704
- Description: Baylis-Hillman reactions of 2,2’-dithiodibenzaldehyde with the acyclic alkenes, methyl vinyl ketone (MVK) and methyl acrylate have afforded the thiochromene derivatives in moderate yields, and this approach has been extended to the use of the cyclic alkenes, 2-cyclohexenone and 2-cyclopentenone to afford the tricyclic analogues. In all cases, reduction of the disulphide link and intramolecular cyclisation occurred in situ, and a preliminary kinetic study of this reaction using the acyclic substrates MVK and methyl acrylate was undertaken with the aim of elucidating the mechanism involved. The results obtained showed that the consumption of both 2,2’-dithiodibenzaldehyde and MVK and/or methyl acrylate followed 1st-order kinetics during the initial stages of the reaction, but then deviated from 1st-order linearity. The reaction with methyl acrylate was much slower than with MVK, and the kinetic data indicates the mechanism to be more complex than anticipated. Conjugate addition reactions of methyl acrylate-derived 2-nitrobenzaldehyde Baylis-Hillman adducts with the amines, piperidine and benzylamine, afforded a range of conjugate addition products as diastereomeric mixtures in excellent yield (80-100%). Catalytic hydrogenation of the conjugate addition products using a Pd-C catalyst in ethanol, has afforded the corresponding, novel 3-amino-2-quinolone derivatives in lower yield (22-37%).The application of [superscript 13]C NMR prediction programmes to selected compounds synthesized in this study has revealed reasonable correlations between the experimental and predicted values.
- Full Text:
- Date Issued: 2008
- Authors: Nyoni, Dubekile
- Date: 2008
- Subjects: Heterocyclic compounds -- Derivatives
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4402 , http://hdl.handle.net/10962/d1006704
- Description: Baylis-Hillman reactions of 2,2’-dithiodibenzaldehyde with the acyclic alkenes, methyl vinyl ketone (MVK) and methyl acrylate have afforded the thiochromene derivatives in moderate yields, and this approach has been extended to the use of the cyclic alkenes, 2-cyclohexenone and 2-cyclopentenone to afford the tricyclic analogues. In all cases, reduction of the disulphide link and intramolecular cyclisation occurred in situ, and a preliminary kinetic study of this reaction using the acyclic substrates MVK and methyl acrylate was undertaken with the aim of elucidating the mechanism involved. The results obtained showed that the consumption of both 2,2’-dithiodibenzaldehyde and MVK and/or methyl acrylate followed 1st-order kinetics during the initial stages of the reaction, but then deviated from 1st-order linearity. The reaction with methyl acrylate was much slower than with MVK, and the kinetic data indicates the mechanism to be more complex than anticipated. Conjugate addition reactions of methyl acrylate-derived 2-nitrobenzaldehyde Baylis-Hillman adducts with the amines, piperidine and benzylamine, afforded a range of conjugate addition products as diastereomeric mixtures in excellent yield (80-100%). Catalytic hydrogenation of the conjugate addition products using a Pd-C catalyst in ethanol, has afforded the corresponding, novel 3-amino-2-quinolone derivatives in lower yield (22-37%).The application of [superscript 13]C NMR prediction programmes to selected compounds synthesized in this study has revealed reasonable correlations between the experimental and predicted values.
- Full Text:
- Date Issued: 2008
The trajectory, dynamics, determinants and nature of institutional change in post-1994 South African higher education
- Authors: Badat, Saleem
- Date: 2008
- Language: English
- Type: Conference paper , text
- Identifier: vital:7120 , http://hdl.handle.net/10962/d1006568
- Description: Introduction: The institutional change agenda in post-1994 South African higher education has been extensive in its objects, ambitious in its goals, and far-reaching in nature. Given its scope, it is not possible here to critically analyse change in all its dimensions or in all arenas. Instead, this paper confines itself to analysing the trajectory, dynamics, outcomes and determinants of institutional change in South African higher education since 1994, and concludes with observations on the nature of change. , Higher Education Close Up 4 : University of Cape Town, Breakwater Conference Centre, 26-28 June 2008
- Full Text:
- Date Issued: 2008
- Authors: Badat, Saleem
- Date: 2008
- Language: English
- Type: Conference paper , text
- Identifier: vital:7120 , http://hdl.handle.net/10962/d1006568
- Description: Introduction: The institutional change agenda in post-1994 South African higher education has been extensive in its objects, ambitious in its goals, and far-reaching in nature. Given its scope, it is not possible here to critically analyse change in all its dimensions or in all arenas. Instead, this paper confines itself to analysing the trajectory, dynamics, outcomes and determinants of institutional change in South African higher education since 1994, and concludes with observations on the nature of change. , Higher Education Close Up 4 : University of Cape Town, Breakwater Conference Centre, 26-28 June 2008
- Full Text:
- Date Issued: 2008
The effect of different management practices on the feed intake and growth rate of ostrich chicks
- Kruger, Anna Christina Magdalena
- Authors: Kruger, Anna Christina Magdalena
- Date: 2008
- Subjects: Ostriches -- South Africa -- Growth
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10589 , http://hdl.handle.net/10948/834 , Ostriches -- South Africa -- Growth
- Description: Different management techniques were studied, at the Kromme Rhee Experimental Farm near Stellenbosch, in order to stimulate feed intake of ostrich chicks and to determine the effect on their growth rate. A first experiment was conducted to determine the effect of different dietary flavourants on the feed intake of ostrich chicks. Ostrich chicks (1-28 days of age), with no previous exposure to flavourants showed a strong preference for salty feed. Another experiment determined the effect of different colourants on the feed intake of ostrich chicks. Exposure of chicks to feed coloured artificially in different colours (green, red, blue and yellow) had no impact on the feed intake of ostrich chicks (1-28 days of age). Throughout the study the dry matter intake was the highest for the control diet, indicating that the provision of coloured feed to ostriches, as practised in this study, will not stimulate feed intake. The effect of feed processing and restriction of water availability for ostrich chicks was also examined. Extrusion reduced microbial counts in feed by 99.7 percent. Feed intake as well as average daily gain of chicks were lowered by both the pelleting and the extrusion process practised in this study. Processing did not have a positive influence on the production of ostrich chicks 6-15 weeks of age. Dry matter intake for chicks subjected to water restriction were the same as for birds receiving water ad libitum. Similarly growth rate as well as feed conversion ratio was not effected by restriction of water, as practised in this study. Another technique studied was to determine the effect of 24h artificial light on feed intake, growth and the behaviour of ostrich chicks (1-28 days of age). A Timeactivity budget revealed that chicks subjected to 24 hours of light spent more time eating (14.7 percent) than those subjected to normal day and night cycles (11.4 percent). In spite of this, no significant difference in feed intake, growth rate and feed conversion ratio was observed for ostrich chicks subjected to different light regimes. The effect of different dietary salt levels on the production of ostrich chicks (8-12 weeks of age) was also determined. The performance of chicks was the best on a diet with a salt inclusion of 1.4 percent.
- Full Text:
- Date Issued: 2008
- Authors: Kruger, Anna Christina Magdalena
- Date: 2008
- Subjects: Ostriches -- South Africa -- Growth
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10589 , http://hdl.handle.net/10948/834 , Ostriches -- South Africa -- Growth
- Description: Different management techniques were studied, at the Kromme Rhee Experimental Farm near Stellenbosch, in order to stimulate feed intake of ostrich chicks and to determine the effect on their growth rate. A first experiment was conducted to determine the effect of different dietary flavourants on the feed intake of ostrich chicks. Ostrich chicks (1-28 days of age), with no previous exposure to flavourants showed a strong preference for salty feed. Another experiment determined the effect of different colourants on the feed intake of ostrich chicks. Exposure of chicks to feed coloured artificially in different colours (green, red, blue and yellow) had no impact on the feed intake of ostrich chicks (1-28 days of age). Throughout the study the dry matter intake was the highest for the control diet, indicating that the provision of coloured feed to ostriches, as practised in this study, will not stimulate feed intake. The effect of feed processing and restriction of water availability for ostrich chicks was also examined. Extrusion reduced microbial counts in feed by 99.7 percent. Feed intake as well as average daily gain of chicks were lowered by both the pelleting and the extrusion process practised in this study. Processing did not have a positive influence on the production of ostrich chicks 6-15 weeks of age. Dry matter intake for chicks subjected to water restriction were the same as for birds receiving water ad libitum. Similarly growth rate as well as feed conversion ratio was not effected by restriction of water, as practised in this study. Another technique studied was to determine the effect of 24h artificial light on feed intake, growth and the behaviour of ostrich chicks (1-28 days of age). A Timeactivity budget revealed that chicks subjected to 24 hours of light spent more time eating (14.7 percent) than those subjected to normal day and night cycles (11.4 percent). In spite of this, no significant difference in feed intake, growth rate and feed conversion ratio was observed for ostrich chicks subjected to different light regimes. The effect of different dietary salt levels on the production of ostrich chicks (8-12 weeks of age) was also determined. The performance of chicks was the best on a diet with a salt inclusion of 1.4 percent.
- Full Text:
- Date Issued: 2008
International law before municipal courts: the role of International Court of Justice decisions in domestic court proceedings with specific reference to United States case examples
- Authors: Mangezi, Mutsa
- Date: 2008
- Subjects: International Court of Justice -- Cases Vienna Convention on Consular Relations (1963) International and municipal law -- United States -- Cases International law -- United States -- Cases Jurisdiction (International law) -- Cases
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3711 , http://hdl.handle.net/10962/d1007325
- Description: In the case of LaGrand (Germany v United States), the International Court of Justice held that the United States (US) had violated its international obligation to Germany under the Vienna Convention on Consular Relations when it executed two German nationals without first informing them of their consular rights. The case came before the court after the United States had disregarded a preliminary ruling passed by the IC], which directed the US not to execute the German nationals pending the outcome of the ICJ case. The decision raised the issue of the effect of ICJ decisions in domestic proceedings and the effectiveness of ICJ enforcement mechanisms. This thesis considers the possibility of a role for national courts as active enforcers of ICJ decisions. It is argued that whilst evidence shows that there is no legal obligation on courts to enforce ICJ decisions, there is certainly room in international law to facilitate this development. In support of this argument, the thesis demonstrates how basic presuppositions about international law have shifted over the last few decades. This shift has been both the impetus and the result of globalisation. The case of LaGrand alongside similar cases is used to show how national courts may play an increased role in the enforcement of ICJ decisions.
- Full Text:
- Date Issued: 2008
- Authors: Mangezi, Mutsa
- Date: 2008
- Subjects: International Court of Justice -- Cases Vienna Convention on Consular Relations (1963) International and municipal law -- United States -- Cases International law -- United States -- Cases Jurisdiction (International law) -- Cases
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3711 , http://hdl.handle.net/10962/d1007325
- Description: In the case of LaGrand (Germany v United States), the International Court of Justice held that the United States (US) had violated its international obligation to Germany under the Vienna Convention on Consular Relations when it executed two German nationals without first informing them of their consular rights. The case came before the court after the United States had disregarded a preliminary ruling passed by the IC], which directed the US not to execute the German nationals pending the outcome of the ICJ case. The decision raised the issue of the effect of ICJ decisions in domestic proceedings and the effectiveness of ICJ enforcement mechanisms. This thesis considers the possibility of a role for national courts as active enforcers of ICJ decisions. It is argued that whilst evidence shows that there is no legal obligation on courts to enforce ICJ decisions, there is certainly room in international law to facilitate this development. In support of this argument, the thesis demonstrates how basic presuppositions about international law have shifted over the last few decades. This shift has been both the impetus and the result of globalisation. The case of LaGrand alongside similar cases is used to show how national courts may play an increased role in the enforcement of ICJ decisions.
- Full Text:
- Date Issued: 2008
Dungamanzi/stirring waters: Tsonga and Shangaan art from southern Africa, Nessa Leibhammer (Ed.): book reviews
- Authors: Simbao, Ruth K
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147358 , vital:38629 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC31053
- Description: A woman known as Nkoma We Lwandle (Cow of the Ocean) and a man, Dunga Manzi (Stirring Waters), are remembered as the first Tsonga diviners. Trained by Nzunzu - a powerful water serpent - they were pulled into a lake for a few months and later emerged as influential healers. Such stories (like the one relayed by Dederen of a young girl, Nsatimuni, who also temporarily disappeared into a lake) represent 'death' and 'rebirth', reflecting Arnold van Gennep's (1909) well-known schema of rites de passage: séparation, marge, and agrégation. Separated from daily life, these characters sink into another world where people breathe in water like a foetus in the liquid depths of a womb, evoking impending new birth (p. 171).
- Full Text:
- Date Issued: 2008
- Authors: Simbao, Ruth K
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147358 , vital:38629 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC31053
- Description: A woman known as Nkoma We Lwandle (Cow of the Ocean) and a man, Dunga Manzi (Stirring Waters), are remembered as the first Tsonga diviners. Trained by Nzunzu - a powerful water serpent - they were pulled into a lake for a few months and later emerged as influential healers. Such stories (like the one relayed by Dederen of a young girl, Nsatimuni, who also temporarily disappeared into a lake) represent 'death' and 'rebirth', reflecting Arnold van Gennep's (1909) well-known schema of rites de passage: séparation, marge, and agrégation. Separated from daily life, these characters sink into another world where people breathe in water like a foetus in the liquid depths of a womb, evoking impending new birth (p. 171).
- Full Text:
- Date Issued: 2008
An investigation of the antimicrobial and antifouling properties of marine algal metabolites
- Authors: Mann, Maryssa Gudrun Ailsa
- Date: 2008 , 2013-07-11
- Subjects: Anti-infective agents , Marine metabolites -- Therapeutic use , Marine algae , Pharmacognosy , Fouling , Marine fouling organisms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3831 , http://hdl.handle.net/10962/d1007465 , Anti-infective agents , Marine metabolites -- Therapeutic use , Marine algae , Pharmacognosy , Fouling , Marine fouling organisms
- Description: Prevention of the accumulation of undesirable biological material i.e. biofouling upon a solid surface requires the use of antifouling systems. The solid surface may be a contact lens, an off shore oil rig or a living organism. When chemicals are employed as a mechanism of defense against biofouling, the agents involved are known as antifouling agents. Marine algae must protect themselves from fouling organisms and it is thought that one of the mechanisms used by these organisms is the production of secondary metabolites with an array of biological activities. In vitro studies have shown numerous compounds isolated from marine algae to possess antibacterial, antifungal and antimacrofouling activity. The aim of this study was to evaluate the secondary metabolite extracts of selected Southern African marine macro-algae as a potential source of compounds that inhibit biofilm formation and that could be used as antifouling agents. In this project, marine macro-algae were collected from various sites along the South African coastline. Their extracts were screened for antimicrobial activity against four ubiquitous microorganisms, Staphylococcus aureus, Klebsiella pneumoniae, Mycobacterium aurm and Candida albicans. Results of screening assays guided the fractionation of two Rhodophyta, Plocamium corallorhiza and Laurencia flexuosa. The algae were fractionated using silica gel column chromatography and compounds were isolated by semi-preparative normal phase HPLC. Compound characterization was performed using UV, IR and advanced one- and two-dimensional NMR (¹H, ¹³C NMR, COSY, HSQC, HMBC and NOESY) spectroscopy and mass spectrometry. Ten halogenated monoterpenes including four members of the small class of halogenated monoterpene aldehydes were isolated from extracts of P. corallorhiza. The compounds isolated included the known compounds 3,4,6,7-tetrachloro-3,7-dimethyl-1-octene; 4,6-dibromo-1, 1-dichloro-3,7 -dimethyl-2E,7 octadiene; 4,8-d ibromo-1,1,7 -trichloro-3, 7-dimethyl-2,5Eoctadiene;1 ,4,8-tribromo-3, 7 -dichloro-3,7-dimethyl-1 E,5E-octadiene; 8-bremo-6, 7-dichloro-3,7-dimethyl-octa-2E,4E-dienal; 4-Bromo-8-chloro-3,7-dimethyl-octa-2E,6E-dienal; 4,6- Dibromo-3,7-dimethyl-octa-2E,7-dienal; 2,4-dichloro-1-(2-chlorovinyl)-1-methyl-5-methylidene-cyclohexane and two new metabolites 4,8-chloro-3,7-dimethyl-2Z,4,6Z-octatrien-1-al and Compound 3.47. Methodology was developed for the chemical derivatization and mass spectrometric analysis of the aldehydic compounds, The aldehyde trapping reagent 0-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride was used to derivatize the molecules, stabilizing them and allowing for their complete characterization. From Laurencia flexuosa a new cuparene sesquiterpene 4-bremo-2-(5-hydroxy-1,2,2- trimethylcyclopent-3-enyl)-5-methylphenol was isolated along with two geometric isomers of the vinyl acetylene bromofucin , An halogenated monoterpene 3S*,4R*-1-bromo-3,4,8-trichloro-9-dichloromethyl-1-E,5-E,7-Z-octatriene was also isolated but was suspected to be a contaminant and an investigation into its biological source revealed that it originated from Plocamium suhrii. A third alga, Martensia elegans was extracted based on published reports of antimicrobial compounds in related species. A new a-alkyl malate derivative was isolated and characterized. Selected compounds isolated during the course of the study were employed in preliminary assays that tested their ability to inhibit biofilm formation by Pseudomonas aeruginosa. The halogenated monoterpenes isolated from the Plocamium species were the only active compounds. 3S*,4R*-1-bromo-3,4,S-trichloro-g-dichloromethyl-1-E,5-E,7-octatriene from P. suhrii inhibited biofilm formation through antibacterial activity on planktonic cells but could not prevent biofilm formation when employed as a film on the surface of microtitre plate wells. 1,4,8-tribromo-3,7-dichloro-3,7-dimethyl-1E,5E-octadiene and 4,6-dibromo-1,1-dichloro-3,7-dimethyl-2E,7-octadiene inhibited biofilm formation when applied as a film to the microtitre plate wells but had no significant antibacterial activity. No potential antifouling agents were identified in this project but the antimicrobial activity exhibited by the crude algal extracts was highly encouraging and a number of new research areas have been identified. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2008
- Authors: Mann, Maryssa Gudrun Ailsa
- Date: 2008 , 2013-07-11
- Subjects: Anti-infective agents , Marine metabolites -- Therapeutic use , Marine algae , Pharmacognosy , Fouling , Marine fouling organisms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3831 , http://hdl.handle.net/10962/d1007465 , Anti-infective agents , Marine metabolites -- Therapeutic use , Marine algae , Pharmacognosy , Fouling , Marine fouling organisms
- Description: Prevention of the accumulation of undesirable biological material i.e. biofouling upon a solid surface requires the use of antifouling systems. The solid surface may be a contact lens, an off shore oil rig or a living organism. When chemicals are employed as a mechanism of defense against biofouling, the agents involved are known as antifouling agents. Marine algae must protect themselves from fouling organisms and it is thought that one of the mechanisms used by these organisms is the production of secondary metabolites with an array of biological activities. In vitro studies have shown numerous compounds isolated from marine algae to possess antibacterial, antifungal and antimacrofouling activity. The aim of this study was to evaluate the secondary metabolite extracts of selected Southern African marine macro-algae as a potential source of compounds that inhibit biofilm formation and that could be used as antifouling agents. In this project, marine macro-algae were collected from various sites along the South African coastline. Their extracts were screened for antimicrobial activity against four ubiquitous microorganisms, Staphylococcus aureus, Klebsiella pneumoniae, Mycobacterium aurm and Candida albicans. Results of screening assays guided the fractionation of two Rhodophyta, Plocamium corallorhiza and Laurencia flexuosa. The algae were fractionated using silica gel column chromatography and compounds were isolated by semi-preparative normal phase HPLC. Compound characterization was performed using UV, IR and advanced one- and two-dimensional NMR (¹H, ¹³C NMR, COSY, HSQC, HMBC and NOESY) spectroscopy and mass spectrometry. Ten halogenated monoterpenes including four members of the small class of halogenated monoterpene aldehydes were isolated from extracts of P. corallorhiza. The compounds isolated included the known compounds 3,4,6,7-tetrachloro-3,7-dimethyl-1-octene; 4,6-dibromo-1, 1-dichloro-3,7 -dimethyl-2E,7 octadiene; 4,8-d ibromo-1,1,7 -trichloro-3, 7-dimethyl-2,5Eoctadiene;1 ,4,8-tribromo-3, 7 -dichloro-3,7-dimethyl-1 E,5E-octadiene; 8-bremo-6, 7-dichloro-3,7-dimethyl-octa-2E,4E-dienal; 4-Bromo-8-chloro-3,7-dimethyl-octa-2E,6E-dienal; 4,6- Dibromo-3,7-dimethyl-octa-2E,7-dienal; 2,4-dichloro-1-(2-chlorovinyl)-1-methyl-5-methylidene-cyclohexane and two new metabolites 4,8-chloro-3,7-dimethyl-2Z,4,6Z-octatrien-1-al and Compound 3.47. Methodology was developed for the chemical derivatization and mass spectrometric analysis of the aldehydic compounds, The aldehyde trapping reagent 0-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride was used to derivatize the molecules, stabilizing them and allowing for their complete characterization. From Laurencia flexuosa a new cuparene sesquiterpene 4-bremo-2-(5-hydroxy-1,2,2- trimethylcyclopent-3-enyl)-5-methylphenol was isolated along with two geometric isomers of the vinyl acetylene bromofucin , An halogenated monoterpene 3S*,4R*-1-bromo-3,4,8-trichloro-9-dichloromethyl-1-E,5-E,7-Z-octatriene was also isolated but was suspected to be a contaminant and an investigation into its biological source revealed that it originated from Plocamium suhrii. A third alga, Martensia elegans was extracted based on published reports of antimicrobial compounds in related species. A new a-alkyl malate derivative was isolated and characterized. Selected compounds isolated during the course of the study were employed in preliminary assays that tested their ability to inhibit biofilm formation by Pseudomonas aeruginosa. The halogenated monoterpenes isolated from the Plocamium species were the only active compounds. 3S*,4R*-1-bromo-3,4,S-trichloro-g-dichloromethyl-1-E,5-E,7-octatriene from P. suhrii inhibited biofilm formation through antibacterial activity on planktonic cells but could not prevent biofilm formation when employed as a film on the surface of microtitre plate wells. 1,4,8-tribromo-3,7-dichloro-3,7-dimethyl-1E,5E-octadiene and 4,6-dibromo-1,1-dichloro-3,7-dimethyl-2E,7-octadiene inhibited biofilm formation when applied as a film to the microtitre plate wells but had no significant antibacterial activity. No potential antifouling agents were identified in this project but the antimicrobial activity exhibited by the crude algal extracts was highly encouraging and a number of new research areas have been identified. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2008
Written out, writing in : orature in the South African literary canon
- Authors: Seddon, Deborah Ann
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:2263 , http://hdl.handle.net/10962/d1004695
- Description: As described by Duncan Brown, South African orature represents "our truly original contribution to world literature" (Brown, Voicing the Text 1). This paper explores how orature might be successfully 'written into' the South African literary canon whilst promoting recognition of its existence as an oral form. My recent experiences of the difficulties, challenges, and benefits of teaching South African orature within the Rhodes University English department, have alerted me to the urgent need for the creation of a student- and teacher-friendly anthology which would collect, re-voice, and adequately contextualise a selection of the seminal works of South African oral poets from the colonial to the post-apartheid periods. Much of this poetry already exists in print-form but, despite an increasing recognition of oral poetry through a number of endeavours such the Poetry Africa Festival, the Lentswe Poetry Project on SABC 2, the Timbila Poetry Project and others, South African orature remains marginal in the country's literary canon. It is largely absent from the curriculum in the literature departments of its universities. The need to redress this situation is crucial, but the process of setting up and teaching an undergraduate course in South African oral poetry, while possible, is complicated. The works of our most important oral poets are scattered in a variety of books, libraries, and collections. The usual process of drawing up a booklist of set texts is undermined by the stark reality that many of the books are out of print. Fully giving voice to these texts is even harder to achieve - CD and video recordings of performances (if they exist at all) are not easily accessed or disseminated.
- Full Text:
- Date Issued: 2008
- Authors: Seddon, Deborah Ann
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:2263 , http://hdl.handle.net/10962/d1004695
- Description: As described by Duncan Brown, South African orature represents "our truly original contribution to world literature" (Brown, Voicing the Text 1). This paper explores how orature might be successfully 'written into' the South African literary canon whilst promoting recognition of its existence as an oral form. My recent experiences of the difficulties, challenges, and benefits of teaching South African orature within the Rhodes University English department, have alerted me to the urgent need for the creation of a student- and teacher-friendly anthology which would collect, re-voice, and adequately contextualise a selection of the seminal works of South African oral poets from the colonial to the post-apartheid periods. Much of this poetry already exists in print-form but, despite an increasing recognition of oral poetry through a number of endeavours such the Poetry Africa Festival, the Lentswe Poetry Project on SABC 2, the Timbila Poetry Project and others, South African orature remains marginal in the country's literary canon. It is largely absent from the curriculum in the literature departments of its universities. The need to redress this situation is crucial, but the process of setting up and teaching an undergraduate course in South African oral poetry, while possible, is complicated. The works of our most important oral poets are scattered in a variety of books, libraries, and collections. The usual process of drawing up a booklist of set texts is undermined by the stark reality that many of the books are out of print. Fully giving voice to these texts is even harder to achieve - CD and video recordings of performances (if they exist at all) are not easily accessed or disseminated.
- Full Text:
- Date Issued: 2008
Treatment and care of children and adolescents diagnosed with Attention deficit/Hyperactivity disorder
- Authors: Snyman, Sanmari
- Date: 2008
- Subjects: Attention-deficit disorder in adolescence , Hyperactive children -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10144 , http://hdl.handle.net/10948/871 , Attention-deficit disorder in adolescence , Hyperactive children -- South Africa -- Port Elizabeth
- Description: Background: In recent years the incidence of Attention Deficit/Hyperactivity Disorder (ADHD) has increased. Objectives: The primary aim of the study was to determine the treatment of children and adolescents diagnosed with ADHD in South Africa and more specifically the Eastern Cape. Methods: The study consisted of two parts, a retrospective drug utilisation study and a questionnaire survey. The drug utilisation study was conducted on chronic medication records of a private sector medical scheme administrator and contained records from 1994 to 2006. A total of 42 250 records representing 8 274 patients and 4 001 families, were analysed. The questionnaire survey was conducted in the Eastern Cape. The questionnaires were distributed by responsible pharmacists to parents of children receiving medication for the treatment of ADHD from his/her pharmacy. Fifty one completed questionnaires were analysed. Results: The average age of patients in the drug utilisation study were 14.28 (SD = 5.50) years. Males represented 77.37 percent of patients. Ritalin® 10 mg was the most frequently prescribed methylphenidate-containing product, followed by Ritalin® LA 20 mg. The two most frequently prescribed active ingredients apart from methylphenidate were fluticasone and budesonide. The two most common comorbid conditions were allergic rhinitis and asthma. The average age of patients in the questionnaire survey was 10.26 (SD = 2.51) years. Males represented 73.58 percent of patients. A third of patients had relatives previously diagnosed with ADHD. Ritalin® 10 mg was the most frequently prescribed methylphenidate-containing product. Conclusion: ADHD is a complex life-long disorder. It does not only affect the child diagnosed with the disorder, but also has effects on the family, schooling system and peer relationship. Therefore, more studies regarding the incidence and treatment of ADHD need to be conducted in South Africa.
- Full Text:
- Date Issued: 2008
- Authors: Snyman, Sanmari
- Date: 2008
- Subjects: Attention-deficit disorder in adolescence , Hyperactive children -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10144 , http://hdl.handle.net/10948/871 , Attention-deficit disorder in adolescence , Hyperactive children -- South Africa -- Port Elizabeth
- Description: Background: In recent years the incidence of Attention Deficit/Hyperactivity Disorder (ADHD) has increased. Objectives: The primary aim of the study was to determine the treatment of children and adolescents diagnosed with ADHD in South Africa and more specifically the Eastern Cape. Methods: The study consisted of two parts, a retrospective drug utilisation study and a questionnaire survey. The drug utilisation study was conducted on chronic medication records of a private sector medical scheme administrator and contained records from 1994 to 2006. A total of 42 250 records representing 8 274 patients and 4 001 families, were analysed. The questionnaire survey was conducted in the Eastern Cape. The questionnaires were distributed by responsible pharmacists to parents of children receiving medication for the treatment of ADHD from his/her pharmacy. Fifty one completed questionnaires were analysed. Results: The average age of patients in the drug utilisation study were 14.28 (SD = 5.50) years. Males represented 77.37 percent of patients. Ritalin® 10 mg was the most frequently prescribed methylphenidate-containing product, followed by Ritalin® LA 20 mg. The two most frequently prescribed active ingredients apart from methylphenidate were fluticasone and budesonide. The two most common comorbid conditions were allergic rhinitis and asthma. The average age of patients in the questionnaire survey was 10.26 (SD = 2.51) years. Males represented 73.58 percent of patients. A third of patients had relatives previously diagnosed with ADHD. Ritalin® 10 mg was the most frequently prescribed methylphenidate-containing product. Conclusion: ADHD is a complex life-long disorder. It does not only affect the child diagnosed with the disorder, but also has effects on the family, schooling system and peer relationship. Therefore, more studies regarding the incidence and treatment of ADHD need to be conducted in South Africa.
- Full Text:
- Date Issued: 2008
Isolation, purification and characterization of a 'factor' from Fusarium oxysporum responsible for platinum nanoparticle formation
- Authors: Govender, Yageshni
- Date: 2008
- Subjects: Nanoparticles , Platinum , Fusarium oxysporum , Fungi , Hydragenase
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3923 , http://hdl.handle.net/10962/d1003982 , Nanoparticles , Platinum , Fusarium oxysporum , Fungi , Hydragenase
- Description: Nanoparticles are microscopic particles in the nanometre range of between 1-100 nm. A wide variety of metal nanoparticles have been found to be produced by prokaryotic and eukaryotic organisms including several fungal species, when exposed to solutions containing metal salts. Previous studies have suggested that this bioreduction of metal particles may occur via an active reductase/hydrogenase enzyme process where H2 is the electron donor and positively charged platinum species act as the electron acceptors becoming reduced to a neutral metal nanoparticle. In view of this on going research, the current study investigated the “factors” in the fungus Fusarium oxysporum which were responsible for platinum nanoparticle formation. The fungus F.oxysporum was used in this study as it has been previously shown to produce a variety of nanoparticles including gold and silver. During exposure of the biomass to H2PtCl6 the initial response to the platinum salts was metal internalisation and subsequent reduction of H2PtCI6 to produce platinum nanoparticles. The observed localization and distribution of platinum precipitates provided some evidence for a hydrogenase mediated bioreduction of platinum salts to produce nanoparticles. Factors secreted by the fungus into the extracellular fluids, were shown to be responsible for platinum nanoparticle formation. From the identification, purification and characterisation studies it was concluded that a hydrogenase and other “factors” were responsible for platinum nanoparticle formation in F.oxysporum. Purification of the hydrogenase by freeze-drying and Sephacryl S200 size exclusion- ion exchange chromatography revealed the enzyme to be a dimer with a 29.4 and 44.5 kDa when analysed by a 10 % SDS-PAGE. Characterisation of the enzyme revealed optimal activity at a pH of 7.5 and temperature of 38 °C while it exhibited a poor thermal stability with a half life of 36 minutes. The kinetic parameters Vmax and Km were 3.16 U ml-1 and 3.64 mM respectively. The purified hydrogenase was used in subsequent experiments for the reduction of platinum salts, H2PtCl6 and PtCl2. the results indicated an over 90 % reduction of the platinum salts and TEM micrographs indicated the production of platinum nanoparticles under the various experimental conditions.
- Full Text:
- Date Issued: 2008
- Authors: Govender, Yageshni
- Date: 2008
- Subjects: Nanoparticles , Platinum , Fusarium oxysporum , Fungi , Hydragenase
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3923 , http://hdl.handle.net/10962/d1003982 , Nanoparticles , Platinum , Fusarium oxysporum , Fungi , Hydragenase
- Description: Nanoparticles are microscopic particles in the nanometre range of between 1-100 nm. A wide variety of metal nanoparticles have been found to be produced by prokaryotic and eukaryotic organisms including several fungal species, when exposed to solutions containing metal salts. Previous studies have suggested that this bioreduction of metal particles may occur via an active reductase/hydrogenase enzyme process where H2 is the electron donor and positively charged platinum species act as the electron acceptors becoming reduced to a neutral metal nanoparticle. In view of this on going research, the current study investigated the “factors” in the fungus Fusarium oxysporum which were responsible for platinum nanoparticle formation. The fungus F.oxysporum was used in this study as it has been previously shown to produce a variety of nanoparticles including gold and silver. During exposure of the biomass to H2PtCl6 the initial response to the platinum salts was metal internalisation and subsequent reduction of H2PtCI6 to produce platinum nanoparticles. The observed localization and distribution of platinum precipitates provided some evidence for a hydrogenase mediated bioreduction of platinum salts to produce nanoparticles. Factors secreted by the fungus into the extracellular fluids, were shown to be responsible for platinum nanoparticle formation. From the identification, purification and characterisation studies it was concluded that a hydrogenase and other “factors” were responsible for platinum nanoparticle formation in F.oxysporum. Purification of the hydrogenase by freeze-drying and Sephacryl S200 size exclusion- ion exchange chromatography revealed the enzyme to be a dimer with a 29.4 and 44.5 kDa when analysed by a 10 % SDS-PAGE. Characterisation of the enzyme revealed optimal activity at a pH of 7.5 and temperature of 38 °C while it exhibited a poor thermal stability with a half life of 36 minutes. The kinetic parameters Vmax and Km were 3.16 U ml-1 and 3.64 mM respectively. The purified hydrogenase was used in subsequent experiments for the reduction of platinum salts, H2PtCl6 and PtCl2. the results indicated an over 90 % reduction of the platinum salts and TEM micrographs indicated the production of platinum nanoparticles under the various experimental conditions.
- Full Text:
- Date Issued: 2008
Designing accessible portals in South Africa: a case study
- Authors: Meyer, Shaun
- Date: 2008
- Subjects: Web portals -- South Africa -- Port Elizabeth , Web site development -- South Africa -- Port Elizabeth , Internet programming , Web sites -- Design
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9782 , http://hdl.handle.net/10948/770 , Web portals -- South Africa -- Port Elizabeth , Web site development -- South Africa -- Port Elizabeth , Internet programming , Web sites -- Design
- Description: Web portals are considered “gateways” to the World Wide Web. These portals are becoming very popular entry points to the Web by offering important services such as email, news, weather reports, course notes and general information. In addition, some portal sites allow users the option of customising the site according to their personal interests. However, disabled and elderly people encounter many accessibility and usability barriers while accessing web portals. A preliminary review of a university portal was conducted to identify some of these accessibility problems. This treatise presents an overview of the processes to be followed when conducting an accessibility and usability evaluation. In addition, it mentions some guidelines to be considered when specifically designing portals for use by many different users from varying backgrounds.
- Full Text:
- Date Issued: 2008
- Authors: Meyer, Shaun
- Date: 2008
- Subjects: Web portals -- South Africa -- Port Elizabeth , Web site development -- South Africa -- Port Elizabeth , Internet programming , Web sites -- Design
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9782 , http://hdl.handle.net/10948/770 , Web portals -- South Africa -- Port Elizabeth , Web site development -- South Africa -- Port Elizabeth , Internet programming , Web sites -- Design
- Description: Web portals are considered “gateways” to the World Wide Web. These portals are becoming very popular entry points to the Web by offering important services such as email, news, weather reports, course notes and general information. In addition, some portal sites allow users the option of customising the site according to their personal interests. However, disabled and elderly people encounter many accessibility and usability barriers while accessing web portals. A preliminary review of a university portal was conducted to identify some of these accessibility problems. This treatise presents an overview of the processes to be followed when conducting an accessibility and usability evaluation. In addition, it mentions some guidelines to be considered when specifically designing portals for use by many different users from varying backgrounds.
- Full Text:
- Date Issued: 2008
A model for sustainable operational excellence through knowledge management practices and continuous improvement principles
- Beeken, Wilhelm Frederik Hartmann
- Authors: Beeken, Wilhelm Frederik Hartmann
- Date: 2008
- Subjects: Organizational effectiveness , Knowledge management
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: vital:8699 , http://hdl.handle.net/10948/1061 , Organizational effectiveness , Knowledge management
- Description: Integrating Knowledge Management maturity with associated Continuous Improvement efforts in order to remain competitive, is absent in most Operational Excellence initiatives. Furthermore, the intertwined relationship of Continuous Improvement and work development becomes a crucial focus area for organisations that wish to establish a continuously evolving management system consisting of core values, methodologies and tools with the aim of creating more satisfied customers with less resources. The old industrial paradigm that focused on labour, capital, materials, and energy viewed technology and knowledge as external influences on production. This framework is now being challenged and a new trend is emerging. This trend seeks to transform the old industrial system to that of a knowledge-based which one can lead to innovation and hence economic advantage. Continuous Improvement as a concept has roots in many other fields, including social-technical system design, human relations progress and the discussion surrounding ‘lean manufacturing’. This study will focus on Continuous Improvement as a noun, referring to on the outcome of the process of a stream of emergent innovations. The primary objective of the study is to create a model that will present an organisation with a three-layer knowledge reference process grid, which will align and depict the surrounding business knowledge functions, knowledge-enabling processes and knowledge-manipulating processes aiming for enabling Operational Excellence. This study promotes the theory that the cognitive domain layer, functional domain layer and resources layer of an organisation can be increasingly stimulated by focusing effort through Continuous Improvement routines towards the associated inter-organisational knowledge processes sustaining Operational Excellence. The proposed model is structured to review, compare, evaluate and integrate existing Knowledge Management practices of ii an organisation within the context of clear definitions for important concepts of Knowledge Management. Additionally the model provides an assessment instrument for evaluating the organisation’s Knowledge Management maturity level. The study concerns itself with two concepts towards business value creation which will lead to increased Operational Excellence. Firstly, the maturity of Knowledge Management processes, and secondly the level of the organisation wide process of focused and continuous incremental improvement namely, Continuous Improvement. A case study with PriceWaterhouseCoopers was concluded and an on-line Internet survey was used with a stratified sample from knowledge workers to test the factors from both a Knowledge Management and Continuous Improvement perspective. These factors were verified by means of a hypotheses network, describing in a structured and descriptive way, the importance of Knowledge Management and Continuous Improvement collectively on sustainable Operational Excellence as an integral development of Operational Excellence. With respect to Knowledge Management practices, the hypothesis network proposed at least three domains, which of knowledge generation, knowledge mobilisation and knowledge application as important input to the proposed process grid of knowledge development and associated layer elements. From a Continuous Improvement principles perspective it is apparent that elements from Continuous Improvement routines and Continuous Improvement characteristics are associated with the organisation Continuous Improvement ability. These findings are also a result of the deliberate design of processes, tools, structures and environments with the intent to increase, renew, share or improve the use of knowledge represented in any of the three elements for structural, human and social of intellectual capital. The proposed model combines the framework of the Boyd cycle as it is conceptualized as self-assessment activities, for it becomes possible to use them as basis of a self-assessment with sense making navigational properties across iii the proposed knowledge process grid for the model. The model will facilitate the concept of a three-layer knowledge reference process grid, which represents the main components of the knowledge processes within the cognitive domain layer, functional layer and resources layer of an organisation. The proposed model will deliver a single value that co-exists with the Knowledge Management maturity level and Continuous Improvement readiness index rating attained. Logical relationships to dynamic, evolving and flexible enabling Knowledge Management practices for each layer of the proposed three-layer knowledge reference process grid will be integrated as output of the proposed model. The research has limitations as Knowledge Management practices were measured using a subjective norm scale. It is suggested that a more comprehensive measure of Knowledge Management maturity processes may be needed to represent this construct. The complexity of the proposed model and the number of associated variables included in the results need further confirmation using possible multiple samples and additional measures of Knowledge Management maturity and Continuous Improvement readiness elements. The benefit of the proposed model as a practical Operational Excellence tool is to overcome the perceived gap of implementing Knowledge Management practices and Continuous Improvement principles collectively to deliver and sustain Operational Excellence.
- Full Text:
- Date Issued: 2008
- Authors: Beeken, Wilhelm Frederik Hartmann
- Date: 2008
- Subjects: Organizational effectiveness , Knowledge management
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: vital:8699 , http://hdl.handle.net/10948/1061 , Organizational effectiveness , Knowledge management
- Description: Integrating Knowledge Management maturity with associated Continuous Improvement efforts in order to remain competitive, is absent in most Operational Excellence initiatives. Furthermore, the intertwined relationship of Continuous Improvement and work development becomes a crucial focus area for organisations that wish to establish a continuously evolving management system consisting of core values, methodologies and tools with the aim of creating more satisfied customers with less resources. The old industrial paradigm that focused on labour, capital, materials, and energy viewed technology and knowledge as external influences on production. This framework is now being challenged and a new trend is emerging. This trend seeks to transform the old industrial system to that of a knowledge-based which one can lead to innovation and hence economic advantage. Continuous Improvement as a concept has roots in many other fields, including social-technical system design, human relations progress and the discussion surrounding ‘lean manufacturing’. This study will focus on Continuous Improvement as a noun, referring to on the outcome of the process of a stream of emergent innovations. The primary objective of the study is to create a model that will present an organisation with a three-layer knowledge reference process grid, which will align and depict the surrounding business knowledge functions, knowledge-enabling processes and knowledge-manipulating processes aiming for enabling Operational Excellence. This study promotes the theory that the cognitive domain layer, functional domain layer and resources layer of an organisation can be increasingly stimulated by focusing effort through Continuous Improvement routines towards the associated inter-organisational knowledge processes sustaining Operational Excellence. The proposed model is structured to review, compare, evaluate and integrate existing Knowledge Management practices of ii an organisation within the context of clear definitions for important concepts of Knowledge Management. Additionally the model provides an assessment instrument for evaluating the organisation’s Knowledge Management maturity level. The study concerns itself with two concepts towards business value creation which will lead to increased Operational Excellence. Firstly, the maturity of Knowledge Management processes, and secondly the level of the organisation wide process of focused and continuous incremental improvement namely, Continuous Improvement. A case study with PriceWaterhouseCoopers was concluded and an on-line Internet survey was used with a stratified sample from knowledge workers to test the factors from both a Knowledge Management and Continuous Improvement perspective. These factors were verified by means of a hypotheses network, describing in a structured and descriptive way, the importance of Knowledge Management and Continuous Improvement collectively on sustainable Operational Excellence as an integral development of Operational Excellence. With respect to Knowledge Management practices, the hypothesis network proposed at least three domains, which of knowledge generation, knowledge mobilisation and knowledge application as important input to the proposed process grid of knowledge development and associated layer elements. From a Continuous Improvement principles perspective it is apparent that elements from Continuous Improvement routines and Continuous Improvement characteristics are associated with the organisation Continuous Improvement ability. These findings are also a result of the deliberate design of processes, tools, structures and environments with the intent to increase, renew, share or improve the use of knowledge represented in any of the three elements for structural, human and social of intellectual capital. The proposed model combines the framework of the Boyd cycle as it is conceptualized as self-assessment activities, for it becomes possible to use them as basis of a self-assessment with sense making navigational properties across iii the proposed knowledge process grid for the model. The model will facilitate the concept of a three-layer knowledge reference process grid, which represents the main components of the knowledge processes within the cognitive domain layer, functional layer and resources layer of an organisation. The proposed model will deliver a single value that co-exists with the Knowledge Management maturity level and Continuous Improvement readiness index rating attained. Logical relationships to dynamic, evolving and flexible enabling Knowledge Management practices for each layer of the proposed three-layer knowledge reference process grid will be integrated as output of the proposed model. The research has limitations as Knowledge Management practices were measured using a subjective norm scale. It is suggested that a more comprehensive measure of Knowledge Management maturity processes may be needed to represent this construct. The complexity of the proposed model and the number of associated variables included in the results need further confirmation using possible multiple samples and additional measures of Knowledge Management maturity and Continuous Improvement readiness elements. The benefit of the proposed model as a practical Operational Excellence tool is to overcome the perceived gap of implementing Knowledge Management practices and Continuous Improvement principles collectively to deliver and sustain Operational Excellence.
- Full Text:
- Date Issued: 2008
The difficulty of living well: effort and failure in the good life
- Authors: Moore, Jesse Alexander
- Date: 2008
- Subjects: Conduct of life Ethics Happiness Values Failure (Psychology) Success Struggle
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2715 , http://hdl.handle.net/10962/d1002845
- Description: We all want to live good lives, but due to the difficulty involved, few of us ever succeed. We usually either fail in our attempts to live well or remain with our safer, and less worthwhile, options. In spite of this, there has been little, if any, investigation of the role that difficulty plays in our attempts to live well, and thus in our conceptions of the good life. Within the field of the good life, philosophers tend to acknowledge the fact that good lives are difficult to live, and leave it at that. Since we must all face the difficulty of living well, the lack of analysis of the implications of difficulty seems a glaring oversight. In order to redress this, I explore the role that difficulty plays in two requirements for living well, namely achievement and reflection. Firstly, I examine the relationship between effort and achievement. I argue that difficulty just is the requirement of effort, and that it is required in order for our achievements to be meaningful and for us to value them. Secondly, I look at the relationship between failure and reflection. I argue that reflection on our failures can lead us to knowledge that helps us to live well and that we would not usually come to if we did not fail. Finally, I look at the roles of effort and failure in some accounts of the good life and I draw on psychological research and theory to provide support for my conclusions about the positive effects of effort. I conclude by examining the implications of reducing difficulty for the future of humankind.
- Full Text:
- Date Issued: 2008
- Authors: Moore, Jesse Alexander
- Date: 2008
- Subjects: Conduct of life Ethics Happiness Values Failure (Psychology) Success Struggle
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2715 , http://hdl.handle.net/10962/d1002845
- Description: We all want to live good lives, but due to the difficulty involved, few of us ever succeed. We usually either fail in our attempts to live well or remain with our safer, and less worthwhile, options. In spite of this, there has been little, if any, investigation of the role that difficulty plays in our attempts to live well, and thus in our conceptions of the good life. Within the field of the good life, philosophers tend to acknowledge the fact that good lives are difficult to live, and leave it at that. Since we must all face the difficulty of living well, the lack of analysis of the implications of difficulty seems a glaring oversight. In order to redress this, I explore the role that difficulty plays in two requirements for living well, namely achievement and reflection. Firstly, I examine the relationship between effort and achievement. I argue that difficulty just is the requirement of effort, and that it is required in order for our achievements to be meaningful and for us to value them. Secondly, I look at the relationship between failure and reflection. I argue that reflection on our failures can lead us to knowledge that helps us to live well and that we would not usually come to if we did not fail. Finally, I look at the roles of effort and failure in some accounts of the good life and I draw on psychological research and theory to provide support for my conclusions about the positive effects of effort. I conclude by examining the implications of reducing difficulty for the future of humankind.
- Full Text:
- Date Issued: 2008
Developing a business model for a community radio station in Port Elizabeth: a case study
- Ngcezula, Anthony Thamsanqa "Delite"
- Authors: Ngcezula, Anthony Thamsanqa "Delite"
- Date: 2008
- Subjects: Radio in community development , Radio broadcasting -- South Africa , Community radio
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8720 , http://hdl.handle.net/10948/906 , Radio in community development , Radio broadcasting -- South Africa , Community radio
- Description: The purpose of this treatise is a development of a suitable model for a community radio station which would lead to operational effectiveness and ensure sustainability. The treatise has three phases namely a theoretical phase, a narration phase and an integration phase. Firstly, in the theoretical phase the research study investigates what the literature review reveals about community radio stations and business models. This treatise argues that a total dependency of community radio stations on donor funding leads to operational ineffectiveness which threatens their sustainability. The treatise also argues that a business model could be adapted for a community radio station by identifying the business issues which the literature review revealed, and use these to deconstruct a theoretical business model. Secondly, in the narrative phase the research study investigates the important business issues for a selected community radio station. The treatise argues the board and management of this selected community radio station revealed additional business issues of operations and gave different ratings to business issues which are important in their operations. Thirdly, in the integration phase, the theoretical model deconstructed in the theoretical phase, was revised by including additional business issues of operations revealed in the narrative phase. The research study concludes that this revised model is a suitable business model for a community radio station and can lead to operational effectiveness and ensure sustainability.
- Full Text:
- Date Issued: 2008
- Authors: Ngcezula, Anthony Thamsanqa "Delite"
- Date: 2008
- Subjects: Radio in community development , Radio broadcasting -- South Africa , Community radio
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8720 , http://hdl.handle.net/10948/906 , Radio in community development , Radio broadcasting -- South Africa , Community radio
- Description: The purpose of this treatise is a development of a suitable model for a community radio station which would lead to operational effectiveness and ensure sustainability. The treatise has three phases namely a theoretical phase, a narration phase and an integration phase. Firstly, in the theoretical phase the research study investigates what the literature review reveals about community radio stations and business models. This treatise argues that a total dependency of community radio stations on donor funding leads to operational ineffectiveness which threatens their sustainability. The treatise also argues that a business model could be adapted for a community radio station by identifying the business issues which the literature review revealed, and use these to deconstruct a theoretical business model. Secondly, in the narrative phase the research study investigates the important business issues for a selected community radio station. The treatise argues the board and management of this selected community radio station revealed additional business issues of operations and gave different ratings to business issues which are important in their operations. Thirdly, in the integration phase, the theoretical model deconstructed in the theoretical phase, was revised by including additional business issues of operations revealed in the narrative phase. The research study concludes that this revised model is a suitable business model for a community radio station and can lead to operational effectiveness and ensure sustainability.
- Full Text:
- Date Issued: 2008
The effect of varied instructions on prison guard role behaviour expectations
- Authors: Githaiga, Sandra J N
- Date: 2008
- Subjects: Prison psychology -- Experiments , Role expectations , Imprisonment -- Experiments
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9908 , http://hdl.handle.net/10948/961 , Prison psychology -- Experiments , Role expectations , Imprisonment -- Experiments
- Description: The Stanford Prison Experiment (SPE) was conducted to determine the psychological and behavioural effects of adopting the roles of prisoners or prison guards. In various published research articles Zimbardo reported that he instructed the prison guards to maintain law and order (Haney, Banks, & Zimbardo, 1973). However, in the Quiet Rage video (Zimbardo, 1989), Zimbardo gave the prison guards additional detailed instructions. To examine the effects of these different instructions on expected prison guard role behaviour, first year Psychology students were requested to predict expected prison guard role behaviour under two different conditions. In the order condition, participants received the instructions used in published research articles. While in the fear condition, participants received the instructions from the Quiet Rage video (Zimbardo, 1989). Participants estimated the likelihood of 50 guard behaviours. Participants in the order condition predicted more pleasant behaviour, while participants in the fear condition predicted more unpleasant behaviours. This indicates that the different instructions influenced their intent to perform the different behaviours. There was no significant difference between the fear and order conditions, and the control behaviours. Participants in both the fear and order conditions rated the control items as expected prison guard role behaviour. Participants in both conditions indicated that they would behave in this manner. Gender had no significant influence on expected prison guard role behavior.
- Full Text:
- Date Issued: 2008
- Authors: Githaiga, Sandra J N
- Date: 2008
- Subjects: Prison psychology -- Experiments , Role expectations , Imprisonment -- Experiments
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9908 , http://hdl.handle.net/10948/961 , Prison psychology -- Experiments , Role expectations , Imprisonment -- Experiments
- Description: The Stanford Prison Experiment (SPE) was conducted to determine the psychological and behavioural effects of adopting the roles of prisoners or prison guards. In various published research articles Zimbardo reported that he instructed the prison guards to maintain law and order (Haney, Banks, & Zimbardo, 1973). However, in the Quiet Rage video (Zimbardo, 1989), Zimbardo gave the prison guards additional detailed instructions. To examine the effects of these different instructions on expected prison guard role behaviour, first year Psychology students were requested to predict expected prison guard role behaviour under two different conditions. In the order condition, participants received the instructions used in published research articles. While in the fear condition, participants received the instructions from the Quiet Rage video (Zimbardo, 1989). Participants estimated the likelihood of 50 guard behaviours. Participants in the order condition predicted more pleasant behaviour, while participants in the fear condition predicted more unpleasant behaviours. This indicates that the different instructions influenced their intent to perform the different behaviours. There was no significant difference between the fear and order conditions, and the control behaviours. Participants in both the fear and order conditions rated the control items as expected prison guard role behaviour. Participants in both conditions indicated that they would behave in this manner. Gender had no significant influence on expected prison guard role behavior.
- Full Text:
- Date Issued: 2008
Utility of the cognitive assessment system (CAS) to predict reading proficiency in grade 1
- Authors: Hüttenrauch, Maria Eleonore
- Date: 2008
- Subjects: Das-Naglieri Cognitive Assessment System , Intelligence tests for preliterates , Cognition in children , Reading disability
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9839 , http://hdl.handle.net/10948/965 , Das-Naglieri Cognitive Assessment System , Intelligence tests for preliterates , Cognition in children , Reading disability
- Description: Reading disability, as the most commonly diagnosed learning disability, continues to pose a tenacious problem to teachers, practitioners and researchers. In an effort to understand the causes of reading disability, voluminous research has been undertaken over the past decades to pinpoint its causes or developmental stumbling blocks. One approach, the Planning, Attention, Simultaneous, and Successive processing (PASS) model, combines neuropsychological theory with elements from cognitive psychology. Based on this model, the Cognitive Assessment System (CAS), as well as methods of intervention for reading disability were developed. Although many studies have been conducted that investigated reading disability in terms of PASS cognitive processes, the final version of the CAS and its predictive utility with respect to reading disability has not been explored to date. The present study aimed to investigate the utility of the CAS, administered at the beginning of grade 1, to predict reading proficiency at the end of grade 1. The sample was comprised of 119 “average” (i.e., belonging to the general population) grade 1 students from schools of the Calgary Board of Education (CBE). The Basic Battery of the CAS was administered to the children in the sample at the beginning of grade 1, as well as four reading subtests of the Woodcock-Johnson Tests of Achievement – Third Edition (WJ-III ACH) at the end of grade 1. The WJ-III ACH yielded a cluster score for basic reading and one for reading comprehension. Correlational and regression analyses were used to address the first aim of this study, namely to explore the relationship between students’ scores on the CAS and their later reading proficiency. To this end, the children’s CAS Full Scale scores and WJ-III ACH cluster scores were subjected to a hierarchical regression analysis, whereby age, gender, and - xviii - SES were kept constant by entering them first in the equation. Next, the relationship between students’ PASS scale scores and the CAS subtest scores respectively and scores on the WJ-III ACH Basic Reading and Reading Comprehension Cluster scores was explored by means of stepwise regression analysis. To improve on the generalizability of results, the regression analyses were conducted on a randomly drawn analysis sample consisting of 80% of the sample, and cross-validated on the remaining 20% of the sample. The second aim of the present study was to ascertain whether clusters could be identified on the basis of CAS performance as well as levels of reading proficiency. To this end, the children’s CAS FS scores, PASS scale scores, and CAS subtest scores were subjected to cluster analyses. The investigation of aim 1 yielded some encouraging results, in that it was found that, together with the covariates: • The CAS FS emerged as a moderately strong predictor of both basic reading and reading comprehension; • Successive processing, in particular the Word Series subtest, significantly predicted basic reading skills; • Successive and simultaneous processing, particularly the Nonverbal Matrices and Sentence Repetition subtests, were significant predictors of reading comprehension; The second aim, which explored the relationship between patterns of CAS cognitive processes and their relationship with reading proficiency, yielded: • Two clusters with distinctly different PASS scale scores and with significant differences between their levels of reading proficiency. Higher PASS scales scores, particularly on the Attention and Planning scales, were associated with higher reading proficiency scores. • Four clusters with distinctly different CAS subtest scores that were also associated with distinctly different levels of reading performance. Good - xix - reading proficiency was associated with good CAS performance, whereas weaker reading proficiency was linked to weaker CAS performance. Biographical variables, such as age and SES were found to be related to performance on the CAS and reading proficiency, while gender did not emerge as an important predictor variable. The present study demonstrated the usefulness of the CAS, particularly its Successive and Simultaneous scales, as potential early predictor of reading disability. An exploration of the relationship between patterns of CAS cognitive processes and later reading proficiency also yielded encouraging and interesting results.
- Full Text:
- Date Issued: 2008
- Authors: Hüttenrauch, Maria Eleonore
- Date: 2008
- Subjects: Das-Naglieri Cognitive Assessment System , Intelligence tests for preliterates , Cognition in children , Reading disability
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9839 , http://hdl.handle.net/10948/965 , Das-Naglieri Cognitive Assessment System , Intelligence tests for preliterates , Cognition in children , Reading disability
- Description: Reading disability, as the most commonly diagnosed learning disability, continues to pose a tenacious problem to teachers, practitioners and researchers. In an effort to understand the causes of reading disability, voluminous research has been undertaken over the past decades to pinpoint its causes or developmental stumbling blocks. One approach, the Planning, Attention, Simultaneous, and Successive processing (PASS) model, combines neuropsychological theory with elements from cognitive psychology. Based on this model, the Cognitive Assessment System (CAS), as well as methods of intervention for reading disability were developed. Although many studies have been conducted that investigated reading disability in terms of PASS cognitive processes, the final version of the CAS and its predictive utility with respect to reading disability has not been explored to date. The present study aimed to investigate the utility of the CAS, administered at the beginning of grade 1, to predict reading proficiency at the end of grade 1. The sample was comprised of 119 “average” (i.e., belonging to the general population) grade 1 students from schools of the Calgary Board of Education (CBE). The Basic Battery of the CAS was administered to the children in the sample at the beginning of grade 1, as well as four reading subtests of the Woodcock-Johnson Tests of Achievement – Third Edition (WJ-III ACH) at the end of grade 1. The WJ-III ACH yielded a cluster score for basic reading and one for reading comprehension. Correlational and regression analyses were used to address the first aim of this study, namely to explore the relationship between students’ scores on the CAS and their later reading proficiency. To this end, the children’s CAS Full Scale scores and WJ-III ACH cluster scores were subjected to a hierarchical regression analysis, whereby age, gender, and - xviii - SES were kept constant by entering them first in the equation. Next, the relationship between students’ PASS scale scores and the CAS subtest scores respectively and scores on the WJ-III ACH Basic Reading and Reading Comprehension Cluster scores was explored by means of stepwise regression analysis. To improve on the generalizability of results, the regression analyses were conducted on a randomly drawn analysis sample consisting of 80% of the sample, and cross-validated on the remaining 20% of the sample. The second aim of the present study was to ascertain whether clusters could be identified on the basis of CAS performance as well as levels of reading proficiency. To this end, the children’s CAS FS scores, PASS scale scores, and CAS subtest scores were subjected to cluster analyses. The investigation of aim 1 yielded some encouraging results, in that it was found that, together with the covariates: • The CAS FS emerged as a moderately strong predictor of both basic reading and reading comprehension; • Successive processing, in particular the Word Series subtest, significantly predicted basic reading skills; • Successive and simultaneous processing, particularly the Nonverbal Matrices and Sentence Repetition subtests, were significant predictors of reading comprehension; The second aim, which explored the relationship between patterns of CAS cognitive processes and their relationship with reading proficiency, yielded: • Two clusters with distinctly different PASS scale scores and with significant differences between their levels of reading proficiency. Higher PASS scales scores, particularly on the Attention and Planning scales, were associated with higher reading proficiency scores. • Four clusters with distinctly different CAS subtest scores that were also associated with distinctly different levels of reading performance. Good - xix - reading proficiency was associated with good CAS performance, whereas weaker reading proficiency was linked to weaker CAS performance. Biographical variables, such as age and SES were found to be related to performance on the CAS and reading proficiency, while gender did not emerge as an important predictor variable. The present study demonstrated the usefulness of the CAS, particularly its Successive and Simultaneous scales, as potential early predictor of reading disability. An exploration of the relationship between patterns of CAS cognitive processes and later reading proficiency also yielded encouraging and interesting results.
- Full Text:
- Date Issued: 2008
An adaptive user interface model for contact centres
- Authors: Jason, Bronwin Anastasia
- Date: 2008
- Subjects: Call centers -- Management , Customer services -- Management , Call centers -- Customer services
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10467 , http://hdl.handle.net/10948/989 , Call centers -- Management , Customer services -- Management , Call centers -- Customer services
- Description: Contact centres (CC), are the primary interaction point between a company and its customers and these are rapidly expanding in terms of both workforce and economic scope. An important challenge for today's CC solutions is to increase the speed at which CCAs retrieve information to answer customer queries. CCAs, however, differ in their ability to respond to these queries and do not interact with the computer user interface (UI) in the same way as they each have different capabilities, experience and expertise. Studies have provided empirical support that user performance can be increased when the computer UI characteristics match the user skill level. Adaptive user interfaces (AUIs) are the key to creating personalised systems. Their sole task is to provide an interface most suitable to users' needs whilst facilitating the users' varying skill levels. The aim of this research was to develop an AUI model for CCs to support and improve the expertise level of CCAs. A literature review of CCs, user expertise, AUIs and existing AUI models resulted in the proposal of an AUI model for CCs. The proposed AUI model was described in terms of its architecture, component-level and interface design. An AUI prototype was developed as a proof-of-concept of the proposed AUI model. A literature review on existing AUI evaluation approaches resulted in an evaluation strategy for the proposed AUI model. The AUI prototype was evaluated according to the evaluation strategy that was identified. User testing incorporating eye-tracking and a post-test questionnaire was used to determine the usefulness and usability of the AUI prototype. Significant results were found with regards to user satisfaction ratings, the learnability of the AUI prototype and its effectiveness. This dissertation makes an important contribution in the design of an AUI model that supports and improves the expertise level of CCAs. The model could be used to assist the development of CC applications incorporating AUIs. Future research is however needed to evaluate the effect of the proposed AUI model in a larger CC environment.
- Full Text:
- Date Issued: 2008
- Authors: Jason, Bronwin Anastasia
- Date: 2008
- Subjects: Call centers -- Management , Customer services -- Management , Call centers -- Customer services
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10467 , http://hdl.handle.net/10948/989 , Call centers -- Management , Customer services -- Management , Call centers -- Customer services
- Description: Contact centres (CC), are the primary interaction point between a company and its customers and these are rapidly expanding in terms of both workforce and economic scope. An important challenge for today's CC solutions is to increase the speed at which CCAs retrieve information to answer customer queries. CCAs, however, differ in their ability to respond to these queries and do not interact with the computer user interface (UI) in the same way as they each have different capabilities, experience and expertise. Studies have provided empirical support that user performance can be increased when the computer UI characteristics match the user skill level. Adaptive user interfaces (AUIs) are the key to creating personalised systems. Their sole task is to provide an interface most suitable to users' needs whilst facilitating the users' varying skill levels. The aim of this research was to develop an AUI model for CCs to support and improve the expertise level of CCAs. A literature review of CCs, user expertise, AUIs and existing AUI models resulted in the proposal of an AUI model for CCs. The proposed AUI model was described in terms of its architecture, component-level and interface design. An AUI prototype was developed as a proof-of-concept of the proposed AUI model. A literature review on existing AUI evaluation approaches resulted in an evaluation strategy for the proposed AUI model. The AUI prototype was evaluated according to the evaluation strategy that was identified. User testing incorporating eye-tracking and a post-test questionnaire was used to determine the usefulness and usability of the AUI prototype. Significant results were found with regards to user satisfaction ratings, the learnability of the AUI prototype and its effectiveness. This dissertation makes an important contribution in the design of an AUI model that supports and improves the expertise level of CCAs. The model could be used to assist the development of CC applications incorporating AUIs. Future research is however needed to evaluate the effect of the proposed AUI model in a larger CC environment.
- Full Text:
- Date Issued: 2008
A historic-hermeneutic critique of luthiery with specific reference to selected South African guiter builders
- Authors: Bower, Rudi
- Date: 2008
- Subjects: Guitar -- Construction , Guitar -- History
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:8512 , http://hdl.handle.net/10948/779 , Guitar -- Construction , Guitar -- History
- Description: This study uses a general historical overview of luthiery that provides the reader with a basic understanding of construction techniques and terminology as a point of departure. From the outset the lack of consensus over an ideal or desired construction technique is highlighted. However, Torres is credited with the establishing of a perceived Spanish tradition of guitar construction and acknowledged as the “father” of the modern guitar. This will serve as a basic framework in which a discussion of six prominent past and present international luthiers can occur. These luthiers, namely Antonio de Torres, Hermann Hauser, Robert Bouchet, Daniel Friederich, Jose Romanillos and Greg Smallman are included in this study by virtue of their influence on the South African luthiers that are featured here. It is noted that these six luthiers, with the exception of Greg Smallman, all adhere to the “Spanish tradition” of guitar construction. Smallman can be considered a foremost proponent of a more recent “modern” school of guitar construction characterized by various innovative construction techniques. These are a result of new demands placed on the guitar as performance instrument because of larger concert venues and more collaboration with different instruments, resulting in a need for a stronger tone and more projection and penetration in sound. These two “poles” of luthiery are then manifested in the discussion on the seven featured South African luthiers. Alistair Thompson, Colin Cleveland, Mervyn Davis, Garth Pickard, Marc Maingard, Rodney Stedall and Hans van den Berg are discussed with special mention made of the features of their instruments, woods used and thoughts on luthiery, against the backdrop of their biographies. The four South African luthiers who build within the “Spanish tradition” (Pickard, Maingard, Stedall and Van den Berg) are distinguished from the three who build outside this so-called tradition (Thompson, Cleveland, Davis). South African luthiery is therefore shown to be an accurate microcosm of luthiery in global terms with styles of construction ranging from very “traditional” to very “modern”. The critical reflection on the information contained in this study appears in the form of a hermeneutic critique on luthiery that occurs within the parameters of the thought of two prominent hermeneutic thinkers, Martin Heidegger and his student, Hans-Georg Gadamer. It is shown that the collaboration that often occurs between guitar makers and performers can be related back to Gadamer and his analysis of Heidegger’s notion of the the hermeneutic circle. It is also argued that luthiery as practiced by the international and South African luthiers featured in this study can be seen both as art and technology in ancient Greek terms in that they are both a mode of revealing. Finally, it is shown how luthiery in its entirety can be viewed as a tradition and that different luthiers respond and add to this tradition in various ways.
- Full Text:
- Date Issued: 2008
- Authors: Bower, Rudi
- Date: 2008
- Subjects: Guitar -- Construction , Guitar -- History
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:8512 , http://hdl.handle.net/10948/779 , Guitar -- Construction , Guitar -- History
- Description: This study uses a general historical overview of luthiery that provides the reader with a basic understanding of construction techniques and terminology as a point of departure. From the outset the lack of consensus over an ideal or desired construction technique is highlighted. However, Torres is credited with the establishing of a perceived Spanish tradition of guitar construction and acknowledged as the “father” of the modern guitar. This will serve as a basic framework in which a discussion of six prominent past and present international luthiers can occur. These luthiers, namely Antonio de Torres, Hermann Hauser, Robert Bouchet, Daniel Friederich, Jose Romanillos and Greg Smallman are included in this study by virtue of their influence on the South African luthiers that are featured here. It is noted that these six luthiers, with the exception of Greg Smallman, all adhere to the “Spanish tradition” of guitar construction. Smallman can be considered a foremost proponent of a more recent “modern” school of guitar construction characterized by various innovative construction techniques. These are a result of new demands placed on the guitar as performance instrument because of larger concert venues and more collaboration with different instruments, resulting in a need for a stronger tone and more projection and penetration in sound. These two “poles” of luthiery are then manifested in the discussion on the seven featured South African luthiers. Alistair Thompson, Colin Cleveland, Mervyn Davis, Garth Pickard, Marc Maingard, Rodney Stedall and Hans van den Berg are discussed with special mention made of the features of their instruments, woods used and thoughts on luthiery, against the backdrop of their biographies. The four South African luthiers who build within the “Spanish tradition” (Pickard, Maingard, Stedall and Van den Berg) are distinguished from the three who build outside this so-called tradition (Thompson, Cleveland, Davis). South African luthiery is therefore shown to be an accurate microcosm of luthiery in global terms with styles of construction ranging from very “traditional” to very “modern”. The critical reflection on the information contained in this study appears in the form of a hermeneutic critique on luthiery that occurs within the parameters of the thought of two prominent hermeneutic thinkers, Martin Heidegger and his student, Hans-Georg Gadamer. It is shown that the collaboration that often occurs between guitar makers and performers can be related back to Gadamer and his analysis of Heidegger’s notion of the the hermeneutic circle. It is also argued that luthiery as practiced by the international and South African luthiers featured in this study can be seen both as art and technology in ancient Greek terms in that they are both a mode of revealing. Finally, it is shown how luthiery in its entirety can be viewed as a tradition and that different luthiers respond and add to this tradition in various ways.
- Full Text:
- Date Issued: 2008