Chief executive officer compensation and the effect on company performance in a South African context
- Authors: Bradley, Samuel
- Date: 2012
- Subjects: Chief executive officers -- Salaries, etc. -- South Africa , Compensation management -- South Africa , Wage surveys -- South Africa , Organizational effectiveness -- Evaluation
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:883 , http://hdl.handle.net/10962/d1001637 , Chief executive officers -- Salaries, etc. -- South Africa , Compensation management -- South Africa , Wage surveys -- South Africa , Organizational effectiveness -- Evaluation
- Description: The goal of this research was to determine, in a South African context, whether there is any correlation between chief executive officer compensation and the performance of the company. For the purposes of the research , the compensation of chief executive officers was broken down into three components: salary, bonus and "other" remuneration, while company performance was measured on return on equity, return on assets and earnings per share figures. Studies on this topic have been carried out in other countries, most notably in the United States of America and the United Kingdom. It appears that no research of a similar nature has been carried out in South Africa. Data in respect of the forty largest listed companies in South Africa were collected over a period of five years. The econometric models used for the research were based on models identified in the literature study. The data were then analysed for evidence of a correlation between chief executive officer compensation and the performance of the company. The results of this study indicate that there is no linear relationship between chief executive officer compensation and company performance variables. The econometric models did, however, show correlations between certain variables, taking into account the other predictor variables in the model. Evidence of correlations between age and experience and compensation was also found , which may present potential avenues of research to scholars in the future.
- Full Text:
- Date Issued: 2012
- Authors: Bradley, Samuel
- Date: 2012
- Subjects: Chief executive officers -- Salaries, etc. -- South Africa , Compensation management -- South Africa , Wage surveys -- South Africa , Organizational effectiveness -- Evaluation
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:883 , http://hdl.handle.net/10962/d1001637 , Chief executive officers -- Salaries, etc. -- South Africa , Compensation management -- South Africa , Wage surveys -- South Africa , Organizational effectiveness -- Evaluation
- Description: The goal of this research was to determine, in a South African context, whether there is any correlation between chief executive officer compensation and the performance of the company. For the purposes of the research , the compensation of chief executive officers was broken down into three components: salary, bonus and "other" remuneration, while company performance was measured on return on equity, return on assets and earnings per share figures. Studies on this topic have been carried out in other countries, most notably in the United States of America and the United Kingdom. It appears that no research of a similar nature has been carried out in South Africa. Data in respect of the forty largest listed companies in South Africa were collected over a period of five years. The econometric models used for the research were based on models identified in the literature study. The data were then analysed for evidence of a correlation between chief executive officer compensation and the performance of the company. The results of this study indicate that there is no linear relationship between chief executive officer compensation and company performance variables. The econometric models did, however, show correlations between certain variables, taking into account the other predictor variables in the model. Evidence of correlations between age and experience and compensation was also found , which may present potential avenues of research to scholars in the future.
- Full Text:
- Date Issued: 2012
Structural analysis of effects of mutations on HIV-1 subtype C protease active site
- Mathu, Alexander Muchugia Nganga
- Authors: Mathu, Alexander Muchugia Nganga
- Date: 2012
- Subjects: HIV (Viruses) -- Research , HIV infections -- Treatment -- Research , Protease inhibitors -- Research , Viruses -- Effect of drugs on -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4013 , http://hdl.handle.net/10962/d1004073 , HIV (Viruses) -- Research , HIV infections -- Treatment -- Research , Protease inhibitors -- Research , Viruses -- Effect of drugs on -- Research
- Description: HIV/AIDS is a global pandemic that poses a great threat especially in Sub-Saharan Africa where the highest population of those infected with the virus is found. It has far reaching medical, socio-economic and scientific implications. The HIV-1 protease enzyme is a prime therapeutic target that has been exploited in an effort to reduce morbidity and mortality. However problems arise from drug toxicity and drug-resistant mutations of the protease which is a motivation for research for new, safer and effective therapies. Evidence exists to show that there are significant genomic differences in Subtype B and C that have a negative effect on the intrinsic binding of inhibitors. It is imperative to look at all perspectives from epidemiological, molecular to the pharmacological ones so as to achieve rational design of therapeutic agents. This study involved the use of in silico structural analysis of the effects of mutations in the active site. The data was provided by the National Institute of Communicable Diseases consisting of HIV-1 Subtype C protease sequences of 29 infants exhibiting drug-resistance to ritonavir and lopinavir. The major active site mutations causing drug resistance identified in this study were M46I, I54V and V82A using the Stanford HIV database tool. Homology modeling without extra restraints produced models with improved quality in comparison to those with restraints. MetaMQAPII results differed when models were visualized as dimers giving erroneous modeled regions in comparison to monomers. A broader study with a larger dataset of HIV-1 subtype C protease sequences is required to increase statistical confidence and in order to identify the pattern of drug resistant mutations. Homology modeling without extra restraints is preferred for calculating homology models for the HIV-1 subtype C. Further investigations needs to be done to ascertain the accuracy of validation results for dimers from MetaMQAPII as it is designed for evaluation of monomers.
- Full Text:
- Date Issued: 2012
- Authors: Mathu, Alexander Muchugia Nganga
- Date: 2012
- Subjects: HIV (Viruses) -- Research , HIV infections -- Treatment -- Research , Protease inhibitors -- Research , Viruses -- Effect of drugs on -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4013 , http://hdl.handle.net/10962/d1004073 , HIV (Viruses) -- Research , HIV infections -- Treatment -- Research , Protease inhibitors -- Research , Viruses -- Effect of drugs on -- Research
- Description: HIV/AIDS is a global pandemic that poses a great threat especially in Sub-Saharan Africa where the highest population of those infected with the virus is found. It has far reaching medical, socio-economic and scientific implications. The HIV-1 protease enzyme is a prime therapeutic target that has been exploited in an effort to reduce morbidity and mortality. However problems arise from drug toxicity and drug-resistant mutations of the protease which is a motivation for research for new, safer and effective therapies. Evidence exists to show that there are significant genomic differences in Subtype B and C that have a negative effect on the intrinsic binding of inhibitors. It is imperative to look at all perspectives from epidemiological, molecular to the pharmacological ones so as to achieve rational design of therapeutic agents. This study involved the use of in silico structural analysis of the effects of mutations in the active site. The data was provided by the National Institute of Communicable Diseases consisting of HIV-1 Subtype C protease sequences of 29 infants exhibiting drug-resistance to ritonavir and lopinavir. The major active site mutations causing drug resistance identified in this study were M46I, I54V and V82A using the Stanford HIV database tool. Homology modeling without extra restraints produced models with improved quality in comparison to those with restraints. MetaMQAPII results differed when models were visualized as dimers giving erroneous modeled regions in comparison to monomers. A broader study with a larger dataset of HIV-1 subtype C protease sequences is required to increase statistical confidence and in order to identify the pattern of drug resistant mutations. Homology modeling without extra restraints is preferred for calculating homology models for the HIV-1 subtype C. Further investigations needs to be done to ascertain the accuracy of validation results for dimers from MetaMQAPII as it is designed for evaluation of monomers.
- Full Text:
- Date Issued: 2012
Structural analysis of prodomain inhibition of cysteine proteases in plasmodium species
- Authors: Njuguna, Joyce Njoki
- Date: 2012
- Subjects: Plasmodium , Cysteine proteinases , Proteolytic enzymes , Malaria -- Chemotherapy , Antimalarials , Plasmodium falciparum
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4021 , http://hdl.handle.net/10962/d1004081 , Plasmodium , Cysteine proteinases , Proteolytic enzymes , Malaria -- Chemotherapy , Antimalarials , Plasmodium falciparum
- Description: Plasmodium is a genus of parasites causing malaria, a virulent protozoan infection in humans resulting in over a million deaths annually. Treatment of malaria is increasingly limited by parasite resistance to available drugs. Hence, there is a need to identify new drug targets and authenticate antimalarial compounds that act on these targets. A relatively new therapeutic approach targets proteolytic enzymes responsible for parasite‟s invasion, rupture and hemoglobin degradation at the erythrocytic stage of infection. Cysteine proteases (CPs) are essential for these crucial roles in the intraerythrocytic parasite. CPs are a diverse group of enzymes subdivided into clans and further subdivided into families. Our interest is in Clan CA, papain family C1 proteases, whose members play numerous roles in human and parasitic metabolism. These proteases are produced as zymogens having an N-terminal extension known as the prodomain which regulates the protease activity by selectively inhibiting its active site, preventing substrate access. A Clan CA protease Falcipain-2 (FP-2) of Plasmodium falciparum is a validated drug target but little is known of its orthologs in other malarial Plasmodium species. This study uses various structural bioinformatics approaches to characterise the prodomain‟s regulatory effect in FP-2 and its orthologs in Plasmodium species (P. vivax, P. berghei, P. knowlesi, P. ovale, P. chabaudi and P. yoelii). This was in an effort to discover short peptides with essential residues to mimic the prodomain‟s inhibition of these proteases, as potential peptidomimetic therapeutic agents. Residues in the prodomain region that spans over the active site are most likely to interact with the subsite residues inhibiting the protease. Sequence analysis revealed conservation of residues in this region of Plasmodium proteases that differed significantly in human proteases. Further prediction of the 3D structure of these proteases by homology modelling allowed visualisation of these interactions revealing differences between parasite and human proteases which will lead to significant contribution in structure based malarial inhibitor design.
- Full Text:
- Date Issued: 2012
- Authors: Njuguna, Joyce Njoki
- Date: 2012
- Subjects: Plasmodium , Cysteine proteinases , Proteolytic enzymes , Malaria -- Chemotherapy , Antimalarials , Plasmodium falciparum
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4021 , http://hdl.handle.net/10962/d1004081 , Plasmodium , Cysteine proteinases , Proteolytic enzymes , Malaria -- Chemotherapy , Antimalarials , Plasmodium falciparum
- Description: Plasmodium is a genus of parasites causing malaria, a virulent protozoan infection in humans resulting in over a million deaths annually. Treatment of malaria is increasingly limited by parasite resistance to available drugs. Hence, there is a need to identify new drug targets and authenticate antimalarial compounds that act on these targets. A relatively new therapeutic approach targets proteolytic enzymes responsible for parasite‟s invasion, rupture and hemoglobin degradation at the erythrocytic stage of infection. Cysteine proteases (CPs) are essential for these crucial roles in the intraerythrocytic parasite. CPs are a diverse group of enzymes subdivided into clans and further subdivided into families. Our interest is in Clan CA, papain family C1 proteases, whose members play numerous roles in human and parasitic metabolism. These proteases are produced as zymogens having an N-terminal extension known as the prodomain which regulates the protease activity by selectively inhibiting its active site, preventing substrate access. A Clan CA protease Falcipain-2 (FP-2) of Plasmodium falciparum is a validated drug target but little is known of its orthologs in other malarial Plasmodium species. This study uses various structural bioinformatics approaches to characterise the prodomain‟s regulatory effect in FP-2 and its orthologs in Plasmodium species (P. vivax, P. berghei, P. knowlesi, P. ovale, P. chabaudi and P. yoelii). This was in an effort to discover short peptides with essential residues to mimic the prodomain‟s inhibition of these proteases, as potential peptidomimetic therapeutic agents. Residues in the prodomain region that spans over the active site are most likely to interact with the subsite residues inhibiting the protease. Sequence analysis revealed conservation of residues in this region of Plasmodium proteases that differed significantly in human proteases. Further prediction of the 3D structure of these proteases by homology modelling allowed visualisation of these interactions revealing differences between parasite and human proteases which will lead to significant contribution in structure based malarial inhibitor design.
- Full Text:
- Date Issued: 2012
The structural arrangements in local government and their role in promoting community participation in basic service delivery: a case study of Emalahleni and Intsika Yethu local municipalities in the Chris Hani District Municipality area
- Authors: Nqwemeshe, Nomvuyo
- Date: 2012
- Subjects: Local government -- South Africa -- Eastern Cape , Municipal services -- South Africa -- Eastern Cape -- Citizen participation , Water utilities -- South Africa -- Eastern Cape -- Citizen participation , Water-supply -- South Africa -- Eastern Cape -- Citizen participation , Community development -- South Africa -- Eastern Cape , Economic development projects -- Evaluation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3315 , http://hdl.handle.net/10962/d1003103
- Description: This study analyses the effectiveness of community participation in service delivery. The area of study, the Chris Ham District Municipality (CHDM), is a Water Services Authority, responsible for ensuring access to water services (water and sanitation) by all communities within its jurisdiction. There are eight local municipalities within the CHDM. The objective of this study is to determine whether systems are in place in local government to promote participation by communities in service delivery projects and whether these systems are being utilised efficiently by the role-players concerned. The role-players in this research are people who are involved in community development programmes of the municipality (municipal staff in the relevant departments of the municipalities under study, the social facilitators, civil society organisations, ward committees, ward councillors, traditional authorities as well as the representatives of communities (Project Steering Committees) who are beneficiaries of the projects under study). The projects that are under study were selected from a readily available list of CHDM capital projects that appear in the 2003/2004 financial year funding plan and are running. The findings of the study at both levels (local and district) show that the municipal environment is not conducive to promoting community participation. This is linked to factors such as the structural arrangements, whereby the offices relevant for promoting community participation are not fully occupied, which provided evidence that community participation is not prioritised. There is lack of coordination of programmes within the local government spheres as well within departments of the DM and strategies for community participation have been found to be non-effective. At project level lack of community participation is linked to the utilisation of ward committees as the only mechanism for community participation regardless of its un-equal and party biased representation. This study therefore concludes that although the systems to promote community participation are in place, they are not effective.
- Full Text:
- Date Issued: 2012
- Authors: Nqwemeshe, Nomvuyo
- Date: 2012
- Subjects: Local government -- South Africa -- Eastern Cape , Municipal services -- South Africa -- Eastern Cape -- Citizen participation , Water utilities -- South Africa -- Eastern Cape -- Citizen participation , Water-supply -- South Africa -- Eastern Cape -- Citizen participation , Community development -- South Africa -- Eastern Cape , Economic development projects -- Evaluation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3315 , http://hdl.handle.net/10962/d1003103
- Description: This study analyses the effectiveness of community participation in service delivery. The area of study, the Chris Ham District Municipality (CHDM), is a Water Services Authority, responsible for ensuring access to water services (water and sanitation) by all communities within its jurisdiction. There are eight local municipalities within the CHDM. The objective of this study is to determine whether systems are in place in local government to promote participation by communities in service delivery projects and whether these systems are being utilised efficiently by the role-players concerned. The role-players in this research are people who are involved in community development programmes of the municipality (municipal staff in the relevant departments of the municipalities under study, the social facilitators, civil society organisations, ward committees, ward councillors, traditional authorities as well as the representatives of communities (Project Steering Committees) who are beneficiaries of the projects under study). The projects that are under study were selected from a readily available list of CHDM capital projects that appear in the 2003/2004 financial year funding plan and are running. The findings of the study at both levels (local and district) show that the municipal environment is not conducive to promoting community participation. This is linked to factors such as the structural arrangements, whereby the offices relevant for promoting community participation are not fully occupied, which provided evidence that community participation is not prioritised. There is lack of coordination of programmes within the local government spheres as well within departments of the DM and strategies for community participation have been found to be non-effective. At project level lack of community participation is linked to the utilisation of ward committees as the only mechanism for community participation regardless of its un-equal and party biased representation. This study therefore concludes that although the systems to promote community participation are in place, they are not effective.
- Full Text:
- Date Issued: 2012
The development of an orodispersible sildenafil citrate tablet intended for paediatric use
- Authors: Dagnolo, Bianca
- Date: 2012
- Subjects: Drug development -- Children -- Research -- South Africa , Pulmonary hypertension -- Children -- Research , Tablets (Medicine) -- Development , Pharmaceutical chemistry -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3751 , http://hdl.handle.net/10962/d1003229 , Drug development -- Children -- Research -- South Africa , Pulmonary hypertension -- Children -- Research , Tablets (Medicine) -- Development , Pharmaceutical chemistry -- Research
- Description: Sildenafil citrate (SC) is a phosphodiesterase-5 inhibitor that is used to treat pulmonary hypertension (PH) in paediatric patients. The purpose of these studies was to develop a formulation and manufacture an orodispersible tablet (ODT) that can be easily administered to neonates and children with PH. The advantages of ODT dosage forms include ease of administration, rapid dissolution of the API, SC. Furthermore the dosage form can be taken without water which is beneficial to patients without immediate access to potable fluids. A simple, rapid, accurate, precise and selective reversed-phase HPLC method was developed and validated in accordance with International Conference on Harmonization (ICH) guidelines and was successfully used for the analysis of SC as raw material and in SC containing pharmaceutical dosage forms. Preformulation studies were performed on SC, alone and in combination with potential excipients that could be used to make tablets. Investigations into potential interactions between SC and the excipients were performed using Differential Scanning Calorimetry (DSC) and Infrared Spectroscopy (IR). DSC results revealed that SC was compatible with all potential excipients except mannitol and magnesium stearate. However these interactions were not observed with IR and therefore it was concluded that the interactions were induced by the high temperatures that DSC operates at. Particle size and shape was also established by use of Scanning Electron Microscopy (SEM) and flow properties were monitored by calculating Carr’s Index (CI) and the Hausner Ratio (HR). Direct compression was used as the method of manufacture for SC tablets as this approach is simple and the most economic production approach. The powder blends were assessed for bulk and tapped density and the CI and HR were used to determine the flowability of the blends. The quality attributes of the resultant tablets that were monitored included uniformity of weight, friability, crushing strength, tensile strength, disintegration, wetting and in vitro dispersion times. Design of Experiments is an efficient statistical approach that has become a popular tool used in the pharmaceutical industry to optimize formulation compositions, as it allows for the investigation of several input factors at the same time whilst not using the tedious and traditional “ modification of one variable at a time” approach. A Central composite experimental design was chosen as the most appropriate means to optimize the formulation as it produces more accurate results as opposed to other experimental designs approaches as input factors are investigated at five different levels. Through the use of mathematical modelling, optimum concentrations of disintegrant(s) and an appropriate blending time were established. Analysis of the data from the experimental design and mathematical modelling studies reveal that no changes in disintegrant concentration or blending time altered the disintegration time of the formulation to any significant extent. This result is most likely due to the fact that the critical disintegrant concentration has been reached and increasing the disintegrant concentration further has no effect on disintegration time. It was also established that a change in the concentration of CMS and CRP altered the wetting time of the tablet significantly. Finally it was noted that there was a linear relationship between blending time and the uniformity of content of the tablets produced in these studies. The optimized product was a white tablet with a diameter of 7.31 mm with a thickness of 2.80mm.The dosage form had no visible cracks or evidence of picking or sticking. The tablet exhibits suitable friability and tensile strength while exhibiting a disintegration time of only 8s. Therefore an orodispersible tablet containing SC intended for paediatric use has been successfully developed, manufactured and optimized through the use of preformulation studies, appropriate quality control monitoring and mathematical modelling. These formulations require further optimization in respect of addition of flavours and or additional sweetening agents.
- Full Text:
- Date Issued: 2012
- Authors: Dagnolo, Bianca
- Date: 2012
- Subjects: Drug development -- Children -- Research -- South Africa , Pulmonary hypertension -- Children -- Research , Tablets (Medicine) -- Development , Pharmaceutical chemistry -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3751 , http://hdl.handle.net/10962/d1003229 , Drug development -- Children -- Research -- South Africa , Pulmonary hypertension -- Children -- Research , Tablets (Medicine) -- Development , Pharmaceutical chemistry -- Research
- Description: Sildenafil citrate (SC) is a phosphodiesterase-5 inhibitor that is used to treat pulmonary hypertension (PH) in paediatric patients. The purpose of these studies was to develop a formulation and manufacture an orodispersible tablet (ODT) that can be easily administered to neonates and children with PH. The advantages of ODT dosage forms include ease of administration, rapid dissolution of the API, SC. Furthermore the dosage form can be taken without water which is beneficial to patients without immediate access to potable fluids. A simple, rapid, accurate, precise and selective reversed-phase HPLC method was developed and validated in accordance with International Conference on Harmonization (ICH) guidelines and was successfully used for the analysis of SC as raw material and in SC containing pharmaceutical dosage forms. Preformulation studies were performed on SC, alone and in combination with potential excipients that could be used to make tablets. Investigations into potential interactions between SC and the excipients were performed using Differential Scanning Calorimetry (DSC) and Infrared Spectroscopy (IR). DSC results revealed that SC was compatible with all potential excipients except mannitol and magnesium stearate. However these interactions were not observed with IR and therefore it was concluded that the interactions were induced by the high temperatures that DSC operates at. Particle size and shape was also established by use of Scanning Electron Microscopy (SEM) and flow properties were monitored by calculating Carr’s Index (CI) and the Hausner Ratio (HR). Direct compression was used as the method of manufacture for SC tablets as this approach is simple and the most economic production approach. The powder blends were assessed for bulk and tapped density and the CI and HR were used to determine the flowability of the blends. The quality attributes of the resultant tablets that were monitored included uniformity of weight, friability, crushing strength, tensile strength, disintegration, wetting and in vitro dispersion times. Design of Experiments is an efficient statistical approach that has become a popular tool used in the pharmaceutical industry to optimize formulation compositions, as it allows for the investigation of several input factors at the same time whilst not using the tedious and traditional “ modification of one variable at a time” approach. A Central composite experimental design was chosen as the most appropriate means to optimize the formulation as it produces more accurate results as opposed to other experimental designs approaches as input factors are investigated at five different levels. Through the use of mathematical modelling, optimum concentrations of disintegrant(s) and an appropriate blending time were established. Analysis of the data from the experimental design and mathematical modelling studies reveal that no changes in disintegrant concentration or blending time altered the disintegration time of the formulation to any significant extent. This result is most likely due to the fact that the critical disintegrant concentration has been reached and increasing the disintegrant concentration further has no effect on disintegration time. It was also established that a change in the concentration of CMS and CRP altered the wetting time of the tablet significantly. Finally it was noted that there was a linear relationship between blending time and the uniformity of content of the tablets produced in these studies. The optimized product was a white tablet with a diameter of 7.31 mm with a thickness of 2.80mm.The dosage form had no visible cracks or evidence of picking or sticking. The tablet exhibits suitable friability and tensile strength while exhibiting a disintegration time of only 8s. Therefore an orodispersible tablet containing SC intended for paediatric use has been successfully developed, manufactured and optimized through the use of preformulation studies, appropriate quality control monitoring and mathematical modelling. These formulations require further optimization in respect of addition of flavours and or additional sweetening agents.
- Full Text:
- Date Issued: 2012
An evaluation of the organizational communication of a performance management system in the city of Windhoek
- Authors: Shilongo, Johannes Angula
- Date: 2012
- Subjects: Communication in organizations -- Namibia -- Windhoek Performance -- Management -- Namibia -- Windhoek Personnel management -- Namibia -- Windhoek Organizational change -- Namibia -- Windhoek Organizational behavior -- Namibia -- Windhoek
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:788 , http://hdl.handle.net/10962/d1003909
- Description: This study evaluated how the communication of the new performance management system by the City of Windhoek influenced the beliefs of its employees and consequently to determine the effects of the communication process on the degree to which buy-in and readiness is created. Armenakis, Harris and Field's (1999) five element model of examining the change recipient's beliefs, namely, discrepancy, appropriateness, principal support, efficacy, and valence was used as a framework for this study. These beliefs play a major role in affecting behaviours of the change recipients (employees) toward the implementation of a new change initiative in an organisation. Discrepancy involves assessing if employees believe that a need for change does really exist in the organization. Appropriateness seeks to find out from the change recipients whether the performance management system being introduced in the organization is an appropriate reaction to the need and the vision of the organisation. Principal support describes the support from change agents and opinion leaders for the organizational change. Efficacy refers to a belief in one's capabilities to organize and execute the courses of action required to produce given attainments. Valence refers to the intrinsic and extrinsic attractiveness (from the change recipient's perspective) associated with the perceived outcome of the change. Literature on organizational change, organizational communication and change implementation were used, to gain and highlight insights regarding the role of change communication during change implementation, and to provide the conceptual framework for the research design and analysis. A single case study research method was used under a mixed research paradigm. The study used a survey questionnaire that was sent to 711 employees; a sufficient and representative 202 questionnaires were returned from all levels of the organization, yielding a response rate of 22.4%. In addition, three focus group interviews of a representative cross section of staff were conducted as also document analysis to collect data for the study. The summative average percentages of levels of agreements and disagreements of the respondents for each of the five change recipient's beliefs indicate a fairly high degree of agreement (buy-in) and considerably low degree of disagreement (resistance) among the respondents to nearly all five change recipient's beliefs. Discrepancy received the highest degree of agreement (buy-in) 84%; efficacy received 73%, appropriateness 66% and valence 59% whereas principal support scored the lowest degree of agreement of about 40% of the respondents. Despite the high degree of agreement (buy-in) for these elements, there was also a notable number of the respondents who neither agreed nor disagreed to some of the five change recipient's beliefs. In particular, principal support had 38%, valence had 28%, and appropriateness had 22% who neither agreed nor disagreed. The degree of disagreement (resistance) is relatively low in almost all five change recipient‟s beliefs except for principal support which indicated slightly higher levels of disagreement (19%). The results of the study indicate that the communication methods e.g., the road show, leaflets and brochures, discussions and training sessions used during the pre-implementation phase of the new performance management system influenced the change recipient‟s beliefs on the discrepancy for the new performance management system. The evidence is that these communication methods and actions helped to create a sense of urgency and the need to implement a new performance management system among employees. The new performance management system was also believed to be appropriate and its appropriateness was justified through the use of various communication methods which provided detailed explanations on how the new performance management system was different to the earlier performance appraisal system. Notwithstanding the belief in the appropriateness of the new performance management system, the study found that the absence of such a performance management system over a long period of time had cultivated a hidden but unifying shared set of values, beliefs and assumptions among employees that seem not to fit or be suitable to the demands of the new performance management system and the current challenges facing the organization. The employees themselves noted this discrepancy. Hence, they argued, there is a need to bring about new culture with new sets of values, beliefs and assumptions that will better suit and support the current demands facing the organisation and its members. The study found that although employees significantly believe that they have high levels of personal self-efficacy, the change message that was communicated to them did not in itself appear to help to create and further develop this employee self-efficacy. The change message mainly focussed on the need for training, and the design of job descriptions and technical aspects of the performance management system. The study revealed that the employees' belief in principal support of the new performance management system was that principal support was seen as less than sufficient or not as evident as they would have liked. Employees remarked that principal support was only conveyed during the initial stage of communication, thereafter, principal support from senior management was seen to have declined throughout the pre-implementation phase. Nonetheless, immediate supervisors and managers were believed to more supportive than senior management. The literature points to a lack of belief in principal support as an important cause of a loss momentum in change initiatives, which in turn may result in cynicism and greater resistance, especially by those who have vested interest in maintaining the status quo. Valence refers to the intrinsic and extrinsic attractiveness (from the change recipient's perspective) associated with the perceived outcome of the change. The results show that respondents have mixed beliefs about the personal benefits associated with the new performance management system. Thus, 63% of the respondents believe that it will benefit them, 75% believe that it will increase their self fulfilment, 68% believe that it will increase their feeling of accomplishment, 45% believe that their fringe benefit will remain the same after it is implemented, and 58% believe that they could earn high performance return. However, the result also shows that there are still many respondents who neither agree nor disagree to the presence of personal valance with regard to the new performance managements system. This study established that the use of various communication methods persuaded the majority of the City of Windhoek employees to view the new performance management system overall in a favourable light. However, interviewees criticised the communications process on the grounds that most of these methods were only used once and were not repeated, as they would have liked. Lessons on this item from other change studies are that when communicating new change initiatives, change agents should use different methods of communication and as many times as possible to influence the belief of employees. This report is structured as follows: Section 1 provides an abstract and introduction to the study. Section 1.2 presents a brief review of core theories and recent empirical studies relevant to the research problem. Section 1.3 provides a description of the research method followed in addressing aim and objectives of this study. Section 1.4 presents the results of the evaluation report and section 1.5 discusses the findings and make conclusive recommendations. Section 2 of this study complements subsection section 1.2 (in section 1) with a more detailed review of the literature on organizational change, organizational communication and change implementation. This more detailed review was conducted before the field work and write up of Section 1. The literature incorporated into Section 1 was distilled from this more detailed review. Similarly, Section 3 of this study complement subsection 1.3 (of section 1) with an extended description of the research design and research procedure followed in the study.
- Full Text:
- Date Issued: 2012
- Authors: Shilongo, Johannes Angula
- Date: 2012
- Subjects: Communication in organizations -- Namibia -- Windhoek Performance -- Management -- Namibia -- Windhoek Personnel management -- Namibia -- Windhoek Organizational change -- Namibia -- Windhoek Organizational behavior -- Namibia -- Windhoek
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:788 , http://hdl.handle.net/10962/d1003909
- Description: This study evaluated how the communication of the new performance management system by the City of Windhoek influenced the beliefs of its employees and consequently to determine the effects of the communication process on the degree to which buy-in and readiness is created. Armenakis, Harris and Field's (1999) five element model of examining the change recipient's beliefs, namely, discrepancy, appropriateness, principal support, efficacy, and valence was used as a framework for this study. These beliefs play a major role in affecting behaviours of the change recipients (employees) toward the implementation of a new change initiative in an organisation. Discrepancy involves assessing if employees believe that a need for change does really exist in the organization. Appropriateness seeks to find out from the change recipients whether the performance management system being introduced in the organization is an appropriate reaction to the need and the vision of the organisation. Principal support describes the support from change agents and opinion leaders for the organizational change. Efficacy refers to a belief in one's capabilities to organize and execute the courses of action required to produce given attainments. Valence refers to the intrinsic and extrinsic attractiveness (from the change recipient's perspective) associated with the perceived outcome of the change. Literature on organizational change, organizational communication and change implementation were used, to gain and highlight insights regarding the role of change communication during change implementation, and to provide the conceptual framework for the research design and analysis. A single case study research method was used under a mixed research paradigm. The study used a survey questionnaire that was sent to 711 employees; a sufficient and representative 202 questionnaires were returned from all levels of the organization, yielding a response rate of 22.4%. In addition, three focus group interviews of a representative cross section of staff were conducted as also document analysis to collect data for the study. The summative average percentages of levels of agreements and disagreements of the respondents for each of the five change recipient's beliefs indicate a fairly high degree of agreement (buy-in) and considerably low degree of disagreement (resistance) among the respondents to nearly all five change recipient's beliefs. Discrepancy received the highest degree of agreement (buy-in) 84%; efficacy received 73%, appropriateness 66% and valence 59% whereas principal support scored the lowest degree of agreement of about 40% of the respondents. Despite the high degree of agreement (buy-in) for these elements, there was also a notable number of the respondents who neither agreed nor disagreed to some of the five change recipient's beliefs. In particular, principal support had 38%, valence had 28%, and appropriateness had 22% who neither agreed nor disagreed. The degree of disagreement (resistance) is relatively low in almost all five change recipient‟s beliefs except for principal support which indicated slightly higher levels of disagreement (19%). The results of the study indicate that the communication methods e.g., the road show, leaflets and brochures, discussions and training sessions used during the pre-implementation phase of the new performance management system influenced the change recipient‟s beliefs on the discrepancy for the new performance management system. The evidence is that these communication methods and actions helped to create a sense of urgency and the need to implement a new performance management system among employees. The new performance management system was also believed to be appropriate and its appropriateness was justified through the use of various communication methods which provided detailed explanations on how the new performance management system was different to the earlier performance appraisal system. Notwithstanding the belief in the appropriateness of the new performance management system, the study found that the absence of such a performance management system over a long period of time had cultivated a hidden but unifying shared set of values, beliefs and assumptions among employees that seem not to fit or be suitable to the demands of the new performance management system and the current challenges facing the organization. The employees themselves noted this discrepancy. Hence, they argued, there is a need to bring about new culture with new sets of values, beliefs and assumptions that will better suit and support the current demands facing the organisation and its members. The study found that although employees significantly believe that they have high levels of personal self-efficacy, the change message that was communicated to them did not in itself appear to help to create and further develop this employee self-efficacy. The change message mainly focussed on the need for training, and the design of job descriptions and technical aspects of the performance management system. The study revealed that the employees' belief in principal support of the new performance management system was that principal support was seen as less than sufficient or not as evident as they would have liked. Employees remarked that principal support was only conveyed during the initial stage of communication, thereafter, principal support from senior management was seen to have declined throughout the pre-implementation phase. Nonetheless, immediate supervisors and managers were believed to more supportive than senior management. The literature points to a lack of belief in principal support as an important cause of a loss momentum in change initiatives, which in turn may result in cynicism and greater resistance, especially by those who have vested interest in maintaining the status quo. Valence refers to the intrinsic and extrinsic attractiveness (from the change recipient's perspective) associated with the perceived outcome of the change. The results show that respondents have mixed beliefs about the personal benefits associated with the new performance management system. Thus, 63% of the respondents believe that it will benefit them, 75% believe that it will increase their self fulfilment, 68% believe that it will increase their feeling of accomplishment, 45% believe that their fringe benefit will remain the same after it is implemented, and 58% believe that they could earn high performance return. However, the result also shows that there are still many respondents who neither agree nor disagree to the presence of personal valance with regard to the new performance managements system. This study established that the use of various communication methods persuaded the majority of the City of Windhoek employees to view the new performance management system overall in a favourable light. However, interviewees criticised the communications process on the grounds that most of these methods were only used once and were not repeated, as they would have liked. Lessons on this item from other change studies are that when communicating new change initiatives, change agents should use different methods of communication and as many times as possible to influence the belief of employees. This report is structured as follows: Section 1 provides an abstract and introduction to the study. Section 1.2 presents a brief review of core theories and recent empirical studies relevant to the research problem. Section 1.3 provides a description of the research method followed in addressing aim and objectives of this study. Section 1.4 presents the results of the evaluation report and section 1.5 discusses the findings and make conclusive recommendations. Section 2 of this study complements subsection section 1.2 (in section 1) with a more detailed review of the literature on organizational change, organizational communication and change implementation. This more detailed review was conducted before the field work and write up of Section 1. The literature incorporated into Section 1 was distilled from this more detailed review. Similarly, Section 3 of this study complement subsection 1.3 (of section 1) with an extended description of the research design and research procedure followed in the study.
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- Date Issued: 2012
A case study of Bigodi Wetland Sanctuary as a community driven Community-Based Natural Resource Management initiative : maintaining livelihoods and wetland health
- Authors: Gosling, Amanda Karen
- Date: 2012
- Subjects: Wetland conservation -- Uganda , Wetland ecology -- Uganda , Natural resources management areas -- Uganda , Rural development -- Uganda
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4752 , http://hdl.handle.net/10962/d1007065 , Wetland conservation -- Uganda , Wetland ecology -- Uganda , Natural resources management areas -- Uganda , Rural development -- Uganda
- Description: Community-Based Natural Resource Management (CBNRM) is considered a win-win approach to reconcile conservation with natural resource use. CBNRM aims to accomplish conservation whilst prioritising development and contributing to poverty alleviation. This study analysed the different components of a CBNRM initiative, Bigodi Wetland Sanctuary (BWS), located in western Uganda. The study was carried out by interviewing the managing committee members (n= 8) as well as local households (n= 68) regarding the manner in which the project works, and the associated benefits and constraints. The main management issues recognised were a lack of monitoring and committee cohesiveness. The information gathered through the household survey enabled the calculation of the value of local livelihood options. This was done on the premise that conservation is better accepted when land users realise the economic value of natural resources. The average annual value of household livelihoods was represented by 30% crop production, 57% natural resource use, and 13% livestock. Lastly, wetland assessments were performed using the WET-Health and WET-EcoServices methodologies from the Wetland Management Series. These assessments indicated that the impacts of local livelihoods on the wetland were currently low but potential issues could arise with the increasing human population density. Ultimately, BWS presents both environmental and social costs and benefits. With a detailed and interdisciplinary method specific recommendations of improvement can be made to reduce such costs and further reconcile the conservation of Bigodi Wetland with local natural resource use..
- Full Text:
- Date Issued: 2012
- Authors: Gosling, Amanda Karen
- Date: 2012
- Subjects: Wetland conservation -- Uganda , Wetland ecology -- Uganda , Natural resources management areas -- Uganda , Rural development -- Uganda
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4752 , http://hdl.handle.net/10962/d1007065 , Wetland conservation -- Uganda , Wetland ecology -- Uganda , Natural resources management areas -- Uganda , Rural development -- Uganda
- Description: Community-Based Natural Resource Management (CBNRM) is considered a win-win approach to reconcile conservation with natural resource use. CBNRM aims to accomplish conservation whilst prioritising development and contributing to poverty alleviation. This study analysed the different components of a CBNRM initiative, Bigodi Wetland Sanctuary (BWS), located in western Uganda. The study was carried out by interviewing the managing committee members (n= 8) as well as local households (n= 68) regarding the manner in which the project works, and the associated benefits and constraints. The main management issues recognised were a lack of monitoring and committee cohesiveness. The information gathered through the household survey enabled the calculation of the value of local livelihood options. This was done on the premise that conservation is better accepted when land users realise the economic value of natural resources. The average annual value of household livelihoods was represented by 30% crop production, 57% natural resource use, and 13% livestock. Lastly, wetland assessments were performed using the WET-Health and WET-EcoServices methodologies from the Wetland Management Series. These assessments indicated that the impacts of local livelihoods on the wetland were currently low but potential issues could arise with the increasing human population density. Ultimately, BWS presents both environmental and social costs and benefits. With a detailed and interdisciplinary method specific recommendations of improvement can be made to reduce such costs and further reconcile the conservation of Bigodi Wetland with local natural resource use..
- Full Text:
- Date Issued: 2012
The impact of clothing and protective gear on biophysical, physiological, perceptual and performance responses of rugby players during a simulated rugby protocol
- Authors: Cannon, Michael-John
- Date: 2012
- Subjects: Protective clothing -- Rugby football -- Health aspects -- Research , Rugby football injuries -- Prevention -- Research , Sports injuries -- Prevention -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5124 , http://hdl.handle.net/10962/d1005202 , Protective clothing -- Rugby football -- Health aspects -- Research , Rugby football injuries -- Prevention -- Research , Sports injuries -- Prevention -- Research
- Description: Background: Clothing and protective gear worn during intermittent exercise has shown to increase physiological and perceptual responses, and negatively impact performance capacities, due to increased heat strain, suggested to hasten the onset of fatigue. However, the mechanisms of fatigue experienced in rugby remain unclear. Objectives: The aim of this study was establish whether clothing and protective gear worn during a simulated rugby protocol impacts players‘ biophysical, physiological, perceptual and performance responses. Methods: 15 registered university and school first XV rugby players with a mean (± SD) age of 20.9 years (± 1.9) volunteered to participate in the study. Testing was performed in a controlled laboratory setting, with temperatures having to be within the range of 16º C-22º C. The mean (± SD) ambient temperature was 17.6º C (± 1.6) for the control condition and 17.3º C (1.5) for the experimental condition. The mean (± SD) relative humidity was 65.2 % (± 9.5) for the control condition and 66.3 % (± 10.0) for the experimental condition. Player‘s performed two protocols of 80-minutes; a control condition (minimal clothing and protective gear) and an experimental condition (full clothing and protective gear). Physiological, perceptual and performance responses were measured at set intervals during the protocol, while biophysical responses were measured pre-, at half-time and post-protocol during a 3-minute EMG treadmill protocol. Results: Muscle activity significantly (p< 0.05) increased with increasing running speeds. There were no significant (p> 0.05) differences for muscle activity between conditions, except for the semitendinosus muscle, which was significantly (p< 0.05) higher during the control condition while running at high speeds. Players‘ heart rates, core temperatures and perceptual responses were significantly (p< 0.05) higher during the experimental condition, compared to the control condition. Performance responses were significantly (p< 0.05) lower during the experimental condition. Conclusion: The main driver of physiological and perceptual responses was the exercise itself. However, the additional clothing and protective gear exacerbated the responses, particularly towards the end stages of the protocol. This negatively impacted players‘ performance. Muscle activity appeared to be unaffected by increased body temperatures. However, core temperatures never reached critically high levels during either condition.
- Full Text:
- Date Issued: 2012
- Authors: Cannon, Michael-John
- Date: 2012
- Subjects: Protective clothing -- Rugby football -- Health aspects -- Research , Rugby football injuries -- Prevention -- Research , Sports injuries -- Prevention -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5124 , http://hdl.handle.net/10962/d1005202 , Protective clothing -- Rugby football -- Health aspects -- Research , Rugby football injuries -- Prevention -- Research , Sports injuries -- Prevention -- Research
- Description: Background: Clothing and protective gear worn during intermittent exercise has shown to increase physiological and perceptual responses, and negatively impact performance capacities, due to increased heat strain, suggested to hasten the onset of fatigue. However, the mechanisms of fatigue experienced in rugby remain unclear. Objectives: The aim of this study was establish whether clothing and protective gear worn during a simulated rugby protocol impacts players‘ biophysical, physiological, perceptual and performance responses. Methods: 15 registered university and school first XV rugby players with a mean (± SD) age of 20.9 years (± 1.9) volunteered to participate in the study. Testing was performed in a controlled laboratory setting, with temperatures having to be within the range of 16º C-22º C. The mean (± SD) ambient temperature was 17.6º C (± 1.6) for the control condition and 17.3º C (1.5) for the experimental condition. The mean (± SD) relative humidity was 65.2 % (± 9.5) for the control condition and 66.3 % (± 10.0) for the experimental condition. Player‘s performed two protocols of 80-minutes; a control condition (minimal clothing and protective gear) and an experimental condition (full clothing and protective gear). Physiological, perceptual and performance responses were measured at set intervals during the protocol, while biophysical responses were measured pre-, at half-time and post-protocol during a 3-minute EMG treadmill protocol. Results: Muscle activity significantly (p< 0.05) increased with increasing running speeds. There were no significant (p> 0.05) differences for muscle activity between conditions, except for the semitendinosus muscle, which was significantly (p< 0.05) higher during the control condition while running at high speeds. Players‘ heart rates, core temperatures and perceptual responses were significantly (p< 0.05) higher during the experimental condition, compared to the control condition. Performance responses were significantly (p< 0.05) lower during the experimental condition. Conclusion: The main driver of physiological and perceptual responses was the exercise itself. However, the additional clothing and protective gear exacerbated the responses, particularly towards the end stages of the protocol. This negatively impacted players‘ performance. Muscle activity appeared to be unaffected by increased body temperatures. However, core temperatures never reached critically high levels during either condition.
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- Date Issued: 2012
Love Interrupted (Short story anthology)
- Authors: Malatji, Reneilwe
- Date: 2012
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:21016 , http://hdl.handle.net/10962/6004
- Description: This collection of stories focuses on struggles between black South African men and women. Several of the stories explore how the rise of the affluent and powerful black woman is redefining relationships. Other stories in the collection describe women who do not know how to free themselves from their subservient role, or do not want to. Issues of interracial relations between blacks and whites in contemporary South Africa also feature in most of the stories.
- Full Text:
- Date Issued: 2012
- Authors: Malatji, Reneilwe
- Date: 2012
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:21016 , http://hdl.handle.net/10962/6004
- Description: This collection of stories focuses on struggles between black South African men and women. Several of the stories explore how the rise of the affluent and powerful black woman is redefining relationships. Other stories in the collection describe women who do not know how to free themselves from their subservient role, or do not want to. Issues of interracial relations between blacks and whites in contemporary South Africa also feature in most of the stories.
- Full Text:
- Date Issued: 2012
Musculoskeletal and perceptual responses of batsmen comparing high- and moderate-volume sprints between the wickets
- Authors: Sheppard, Bronwyn Jane
- Date: 2012
- Subjects: Cricket -- Batting -- Physiological aspects , Cricket injuries , Musculoskeletal system -- Wounds and injuries
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5171 , http://hdl.handle.net/10962/d1016366
- Description: Background: Literature has associated repeated eccentric muscle actions with increased muscle damage of the muscles involved. Eccentric actions are typical in sports which are ‘stop-start’ in nature requiring rapid acceleration and deceleration, typical of a batting activity in cricket. Ultra-structural damage of the skeletal muscle as a consequence of repeated decelerating activities is associated with performance decrements, particularly muscle strength and sprinting speeds. This suggests that eccentric strength decrements may provide an indication for the development of muscle strain injuries during these activities. Despite these findings, limited research has identified the specific musculoskeletal demands placed on cricket batsmen, particularly with reference to various match intensities. Objective: The present study, therefore, sought to determine the specific musculoskeletal, physiological and perceptual demands placed on specialised batsmen during two work bouts of different intensities; one representing a highintensity work bout and the other a moderate-intensity work bout. The dependent variables of interest were muscle activation, isokinetic strength changes, heart rate, ‘central’ and ‘local’ ratings of perceived exertion (RPE), body discomfort and performance. Methods: The two experimental conditions, representative of a high- (HVR) and moderate-volume running (MVR) batting protocol, required players to perform a simulated batting work bout of either twelve or six runs an over, within a laboratory setting. Selected physiological, perceptual and performance measures were collected at specific time intervals throughout the work bout while the biophysical measures were collected prior to, and following both protocols. Results: Of the variables measured, heart rate, ‘central’ and ‘local’ RPE values were observed to increase significantly (p<0.05) over time. This increase was greater as a consequence of the HVR in comparison to the MVR. No change in sprint times was documented during the MVR, in contrast, significant (p<0.05) increases over time were observed during the HVR, further highlighting the elevated demands associated with this condition. In addition, an ‘end spurt’ was observed particularly following the HVR condition, suggesting athletes were conserving themselves through the adoption of a pacing strategy. Reductions in biceps femoris and semitendinosus muscle activation levels were observed following the HVR. This was further supported by the significantly greater levels of semitendinosus activation following the MVR when compared to the HVR. Peak concentric and eccentric knee extensor (EXT) (-17.17% and -16.07% respectively) and eccentric flexor (FLEX) (- 17.49%) values decreased significantly (p<0.05) following the HVR at 60°.s-1. In addition, concentric and eccentric total work produced by the flexors and eccentric extensors resulted in significantly (p<0.05) lower values due to the HVR. Conclusion: The intermittent high-volume batting work bout elicited elevated mean heart rates, perceived ratings of cardiovascular and muscular effort and sprint times. Furthermore, hamstring activation levels and muscle strength, particularly concentric strength of the dominant lower limb were negatively affected by the HVR condition. These results suggest elevated demands were placed on the hamstring musculature as a consequence of the HVR condition, indicating a greater degree of musculoskeletal strain and increased injury risk associated with running between the wickets at this intensity, representative of an aggressive batting scenario.
- Full Text:
- Date Issued: 2012
- Authors: Sheppard, Bronwyn Jane
- Date: 2012
- Subjects: Cricket -- Batting -- Physiological aspects , Cricket injuries , Musculoskeletal system -- Wounds and injuries
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5171 , http://hdl.handle.net/10962/d1016366
- Description: Background: Literature has associated repeated eccentric muscle actions with increased muscle damage of the muscles involved. Eccentric actions are typical in sports which are ‘stop-start’ in nature requiring rapid acceleration and deceleration, typical of a batting activity in cricket. Ultra-structural damage of the skeletal muscle as a consequence of repeated decelerating activities is associated with performance decrements, particularly muscle strength and sprinting speeds. This suggests that eccentric strength decrements may provide an indication for the development of muscle strain injuries during these activities. Despite these findings, limited research has identified the specific musculoskeletal demands placed on cricket batsmen, particularly with reference to various match intensities. Objective: The present study, therefore, sought to determine the specific musculoskeletal, physiological and perceptual demands placed on specialised batsmen during two work bouts of different intensities; one representing a highintensity work bout and the other a moderate-intensity work bout. The dependent variables of interest were muscle activation, isokinetic strength changes, heart rate, ‘central’ and ‘local’ ratings of perceived exertion (RPE), body discomfort and performance. Methods: The two experimental conditions, representative of a high- (HVR) and moderate-volume running (MVR) batting protocol, required players to perform a simulated batting work bout of either twelve or six runs an over, within a laboratory setting. Selected physiological, perceptual and performance measures were collected at specific time intervals throughout the work bout while the biophysical measures were collected prior to, and following both protocols. Results: Of the variables measured, heart rate, ‘central’ and ‘local’ RPE values were observed to increase significantly (p<0.05) over time. This increase was greater as a consequence of the HVR in comparison to the MVR. No change in sprint times was documented during the MVR, in contrast, significant (p<0.05) increases over time were observed during the HVR, further highlighting the elevated demands associated with this condition. In addition, an ‘end spurt’ was observed particularly following the HVR condition, suggesting athletes were conserving themselves through the adoption of a pacing strategy. Reductions in biceps femoris and semitendinosus muscle activation levels were observed following the HVR. This was further supported by the significantly greater levels of semitendinosus activation following the MVR when compared to the HVR. Peak concentric and eccentric knee extensor (EXT) (-17.17% and -16.07% respectively) and eccentric flexor (FLEX) (- 17.49%) values decreased significantly (p<0.05) following the HVR at 60°.s-1. In addition, concentric and eccentric total work produced by the flexors and eccentric extensors resulted in significantly (p<0.05) lower values due to the HVR. Conclusion: The intermittent high-volume batting work bout elicited elevated mean heart rates, perceived ratings of cardiovascular and muscular effort and sprint times. Furthermore, hamstring activation levels and muscle strength, particularly concentric strength of the dominant lower limb were negatively affected by the HVR condition. These results suggest elevated demands were placed on the hamstring musculature as a consequence of the HVR condition, indicating a greater degree of musculoskeletal strain and increased injury risk associated with running between the wickets at this intensity, representative of an aggressive batting scenario.
- Full Text:
- Date Issued: 2012
Macroeconomic determinants of stock market behaviour in South Africa
- Authors: Junkin, Kyle
- Date: 2012
- Subjects: Stocks -- Prices -- South Africa Macroeconomics Risk management -- South Africa Stock exchanges -- South Africa Interest rates -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1016 , http://hdl.handle.net/10962/d1002751
- Description: This study investigates whether stock prices in South Africa are influenced by macroeconomic variables, and furthermore, the effects of financial crises on stock prices. The relationship between stock prices and the macroeconomy is a particularly important issue for investors, since a thorough understanding of such a relationship is likely to yield profitable or risk mitigating opportunities. Using monthly data for the period 1995 to 2010 the study focused at a macro level using the FTSE/JSE All Share Index, and at a micro level using sector indices. These included the construction and materials, financial, food producers’, general retailers, industrial, mining and pharmaceuticals indices. The Johansen and Juselius (1990) multivariate cointegration approach was employed, along with impulse response and variance decomposition tests to address the issue. The results showed that macroeconomic variables do have a significant influence on stock prices in South Africa. Also, the influences of these variables were found to have an inconsistent effect across the sectors under investigation. For example, inflation was found to negatively influence the All Share Index, but impacted the industrial index positively. These inconsistent influences on the various sectors were seen to have important diversification implications for investors. The impact of past financial crises proved to be significant on certain indices, however, indices such as that of the pharmaceuticals sector was found to be largely unaffected by such crises. The findings of the study were discussed through an investor’s perspective, and recommendations on investment decisions were given. The limitations of the study were such that certain results may have been influenced by a mis-specification of variables, particularly the Treasury bill rate.
- Full Text:
- Date Issued: 2012
- Authors: Junkin, Kyle
- Date: 2012
- Subjects: Stocks -- Prices -- South Africa Macroeconomics Risk management -- South Africa Stock exchanges -- South Africa Interest rates -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1016 , http://hdl.handle.net/10962/d1002751
- Description: This study investigates whether stock prices in South Africa are influenced by macroeconomic variables, and furthermore, the effects of financial crises on stock prices. The relationship between stock prices and the macroeconomy is a particularly important issue for investors, since a thorough understanding of such a relationship is likely to yield profitable or risk mitigating opportunities. Using monthly data for the period 1995 to 2010 the study focused at a macro level using the FTSE/JSE All Share Index, and at a micro level using sector indices. These included the construction and materials, financial, food producers’, general retailers, industrial, mining and pharmaceuticals indices. The Johansen and Juselius (1990) multivariate cointegration approach was employed, along with impulse response and variance decomposition tests to address the issue. The results showed that macroeconomic variables do have a significant influence on stock prices in South Africa. Also, the influences of these variables were found to have an inconsistent effect across the sectors under investigation. For example, inflation was found to negatively influence the All Share Index, but impacted the industrial index positively. These inconsistent influences on the various sectors were seen to have important diversification implications for investors. The impact of past financial crises proved to be significant on certain indices, however, indices such as that of the pharmaceuticals sector was found to be largely unaffected by such crises. The findings of the study were discussed through an investor’s perspective, and recommendations on investment decisions were given. The limitations of the study were such that certain results may have been influenced by a mis-specification of variables, particularly the Treasury bill rate.
- Full Text:
- Date Issued: 2012
The praxis of responsible investment in South Africa: a holistic case study of Evolution One Fund
- Zaulochnaya Ya-Brouwer, Irina
- Authors: Zaulochnaya Ya-Brouwer, Irina
- Date: 2012
- Subjects: Social responsibility of business -- South Africa Investments -- Moral and ethical aspects -- South Africa Institutional investments -- Moral and ethical aspects -- South Africa Private equity funds -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:778 , http://hdl.handle.net/10962/d1003899
- Description: At the beginning of the 21st century the public interest in environmental and social sustainability, and corporate governance grew exponentially fuelled by recurring ecological and financial crises. The market demand for cleaner production and corporate transparency created opportunities for sustainability entrepreneurs in a variety of industries, including financial markets and investment management. An increasing number of financial institutions across the world now offer ethical or socially responsible products to meet the environmental, social and governance (ESG) aspirations of their clients. In the US, according to the Social Investment Forum (SIF), responsible investment (RI) assets reached US$ 2,29 trillion in 2007 (Mitchell, 2008). The European Sustainable Investment Forum (EuroSIF) estimated that total European SRI assets reached EUR 5 trillion in 2009 (Wheelan, 2010). In June 2011 the International Finance Corporation (IFC) reported that at the end of 2010 professional sustainable investment under management in South Africa approximately equalled US$ 122,6 billion (IFC, 2011:44). The statistics describing the rapid growth in the ESG-type investments are, however, complicated by the variety of names and definitions used to describe this emerging type of investment and a general market uncertainty about what constitutes the practice of RI. The purpose of this case study is to better understand responsible investment principles and practice as seen through the eyes of a South African private equity fund, which specializes in clean technology.
- Full Text:
- Date Issued: 2012
- Authors: Zaulochnaya Ya-Brouwer, Irina
- Date: 2012
- Subjects: Social responsibility of business -- South Africa Investments -- Moral and ethical aspects -- South Africa Institutional investments -- Moral and ethical aspects -- South Africa Private equity funds -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:778 , http://hdl.handle.net/10962/d1003899
- Description: At the beginning of the 21st century the public interest in environmental and social sustainability, and corporate governance grew exponentially fuelled by recurring ecological and financial crises. The market demand for cleaner production and corporate transparency created opportunities for sustainability entrepreneurs in a variety of industries, including financial markets and investment management. An increasing number of financial institutions across the world now offer ethical or socially responsible products to meet the environmental, social and governance (ESG) aspirations of their clients. In the US, according to the Social Investment Forum (SIF), responsible investment (RI) assets reached US$ 2,29 trillion in 2007 (Mitchell, 2008). The European Sustainable Investment Forum (EuroSIF) estimated that total European SRI assets reached EUR 5 trillion in 2009 (Wheelan, 2010). In June 2011 the International Finance Corporation (IFC) reported that at the end of 2010 professional sustainable investment under management in South Africa approximately equalled US$ 122,6 billion (IFC, 2011:44). The statistics describing the rapid growth in the ESG-type investments are, however, complicated by the variety of names and definitions used to describe this emerging type of investment and a general market uncertainty about what constitutes the practice of RI. The purpose of this case study is to better understand responsible investment principles and practice as seen through the eyes of a South African private equity fund, which specializes in clean technology.
- Full Text:
- Date Issued: 2012
The synthesis and breast cancer inhibitory activity of cinnamic acid analogues based on the halogenated monoterpene pharmacophore
- Authors: Chiwakata, Maynard Tendai
- Date: 2012
- Subjects: Halocarbons , Cancer -- Treatment , Breast -- Cancer -- Treatment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3866 , http://hdl.handle.net/10962/d1016129
- Description: Breast cancer is one of the leading causes of death, with mortality rate estimates of 465 000 deaths per annum. It is estimated that 1.3 million women are diagnosed with the disease each year especially in the developing countries. Current chemotherapy relies on the use of high doses of non-specific toxic agents that possess adverse side effects and compromise patient’s compliance and adherence to treatment. Paclitaxel, one of the common drugs used in breast cancer chemotherapy results in sensory and motor neuropathy, whilst hormonal therapy e.g. Herceptin causes severe cardiovascular, gastrointestinal and cutaneous side effects. There has been a demand in developing newer cancer agents that demonstrate selective cytoxicity with minimal effect on normal body tissue. Numerous studies have shown that marine organisms produce a wide range of halogenated compounds that possess cytotoxic properties, and hence can be a source of new drug hits or leads for cancer therapy. Halomon, a polyhalogenated monoterpene from Portieria hornemannii, displayed interesting activity against brain, renal and lung cancer tumours with selective/differential cytotoxicity. This inspired us to focus our project on halogenated monoterpenes isolated from the same Rhodophyta class as P. hornemannii but with particular attention to Plocamium species. Several metabolites have been isolated from P. cornutum, P. corallorhiza and P. suhrii that possess interesting cytotoxicities against a breast cancer cell line (MCF7) and an oesophageal cancer line (WHCO1). The aim of the project was therefore centred at isolating target compounds for preliminary structure-activity studies against a breast cancer cell line, and use this information to synthesize a series of analogues that are more stable than the natural products and yet as active using a fragment-based type approach to map out pharmacophoric elements. Five metabolites were isolated from P. cornutum and five from P. corallorhiza. Cell-based assays were conducted using an MTT assay kit against MCF7 and MDA-MB-231 breast cancer cell lines and (1E,3E,5S,6R)-1,5,6-trichloro-2-(dichloromethyl)-6-methylocta-1,3,7-triene, isolated from P. cornutum was the most active with IC50 values of 3.0 μM and 6.15 μM respectively. Introduction of a terminal aromatic ring to enhance stability, together with varying substituents (H, CH3, CF3, Br, CN, CHO, CHCl2) on position 7 of the molecule, gave rise to a series of cinnamate ester derivatives inspired by (1E,3E,5S,6R)-1,5,6-trichloro-2-(dichloromethyl)-6-methylocta-1,3,7-triene. The analogues were synthesized from their benzaldehyde precursors via Aldol condensation, esterification and Wittig reactions. Their carboxylic acid counterparts were synthesized by hydrolysis of the parent esters in an attempt to promote water solubilities of the analogues. Biological activity assays were then conducted with the cinnamate analogues against the MDA-MB-231 breast cancer cell line using an MTT assay kit. Ester derivatives with -CHO and -CHCl2 functionalities had IC50 values of 43.45 μM and 100.01 μM respectively whilst the other ester derivatives were inactive. It was concluded that either an aldehyde (-CHO) or gem-dichlorides (-CHCl2) is specifically required for cytotoxic activity to be observed. None of the carboxylic acids were active which could have been due to failure of the compounds to enter the breast cancer cells and reach the target site because of their polar nature. Compounds with -CHO and -CHCl2 functionalities were therefore selected for future SARs studies.
- Full Text:
- Date Issued: 2012
- Authors: Chiwakata, Maynard Tendai
- Date: 2012
- Subjects: Halocarbons , Cancer -- Treatment , Breast -- Cancer -- Treatment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3866 , http://hdl.handle.net/10962/d1016129
- Description: Breast cancer is one of the leading causes of death, with mortality rate estimates of 465 000 deaths per annum. It is estimated that 1.3 million women are diagnosed with the disease each year especially in the developing countries. Current chemotherapy relies on the use of high doses of non-specific toxic agents that possess adverse side effects and compromise patient’s compliance and adherence to treatment. Paclitaxel, one of the common drugs used in breast cancer chemotherapy results in sensory and motor neuropathy, whilst hormonal therapy e.g. Herceptin causes severe cardiovascular, gastrointestinal and cutaneous side effects. There has been a demand in developing newer cancer agents that demonstrate selective cytoxicity with minimal effect on normal body tissue. Numerous studies have shown that marine organisms produce a wide range of halogenated compounds that possess cytotoxic properties, and hence can be a source of new drug hits or leads for cancer therapy. Halomon, a polyhalogenated monoterpene from Portieria hornemannii, displayed interesting activity against brain, renal and lung cancer tumours with selective/differential cytotoxicity. This inspired us to focus our project on halogenated monoterpenes isolated from the same Rhodophyta class as P. hornemannii but with particular attention to Plocamium species. Several metabolites have been isolated from P. cornutum, P. corallorhiza and P. suhrii that possess interesting cytotoxicities against a breast cancer cell line (MCF7) and an oesophageal cancer line (WHCO1). The aim of the project was therefore centred at isolating target compounds for preliminary structure-activity studies against a breast cancer cell line, and use this information to synthesize a series of analogues that are more stable than the natural products and yet as active using a fragment-based type approach to map out pharmacophoric elements. Five metabolites were isolated from P. cornutum and five from P. corallorhiza. Cell-based assays were conducted using an MTT assay kit against MCF7 and MDA-MB-231 breast cancer cell lines and (1E,3E,5S,6R)-1,5,6-trichloro-2-(dichloromethyl)-6-methylocta-1,3,7-triene, isolated from P. cornutum was the most active with IC50 values of 3.0 μM and 6.15 μM respectively. Introduction of a terminal aromatic ring to enhance stability, together with varying substituents (H, CH3, CF3, Br, CN, CHO, CHCl2) on position 7 of the molecule, gave rise to a series of cinnamate ester derivatives inspired by (1E,3E,5S,6R)-1,5,6-trichloro-2-(dichloromethyl)-6-methylocta-1,3,7-triene. The analogues were synthesized from their benzaldehyde precursors via Aldol condensation, esterification and Wittig reactions. Their carboxylic acid counterparts were synthesized by hydrolysis of the parent esters in an attempt to promote water solubilities of the analogues. Biological activity assays were then conducted with the cinnamate analogues against the MDA-MB-231 breast cancer cell line using an MTT assay kit. Ester derivatives with -CHO and -CHCl2 functionalities had IC50 values of 43.45 μM and 100.01 μM respectively whilst the other ester derivatives were inactive. It was concluded that either an aldehyde (-CHO) or gem-dichlorides (-CHCl2) is specifically required for cytotoxic activity to be observed. None of the carboxylic acids were active which could have been due to failure of the compounds to enter the breast cancer cells and reach the target site because of their polar nature. Compounds with -CHO and -CHCl2 functionalities were therefore selected for future SARs studies.
- Full Text:
- Date Issued: 2012
A process-genre approach to teaching argumentative writing to grade nine learners
- Authors: Elson, Jillian Margaret
- Date: 2012
- Subjects: English language -- Rhetoric -- Study and teaching (Secondary) English language -- Writing -- Study and teaching (Secondary) Written communication
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1714 , http://hdl.handle.net/10962/d1003597
- Description: This action research study aimed to improve teaching and learning of argumentative writing through a process-genre approach. Learners were carefully guided through the processes of writing the argumentative genre, with the focus being on teaching of the genre and on the structural conventions of writing arguments. Participants were a class of grade nine learners who speak English as a first language. They were chosen for this study as Grade Nine is a crucial year for writing development before learners enter the senior phase and are met with heightened expectations in the curriculum, that often they struggle to meet, as their writing has not been sufficiently developed to an academic level. The focus of writing in Grade Nine is on narrative and prose, so this writing intervention, in which a teaching module was developed in collaboration with the 1eamers, aimed to broaden their writing skills and provide them with a head start in leaming the fine art of argumentation, as this is a useful skill to acquire for purposes even beyond the classroom. Genre theorists advocate the importance of teaching genres to leamers at a young age, as it allows them access into different communities of discourse, as they become aware and understand the conventions held by a patiicular community, and realize the purpose of different styles of writing for effectively communicating, which prepares them to meet the expectations of their audience. Teaching the structures of different genres therefore allows the writer, and the audience, a framework for understanding the text. The process approach has been widely used by educators as it focuses on explicit teaching of writing processes that are fundamental to leamers' development in writing. Learners need to be carefully guided from the initial stages, to the more complex stages (especially in argumentative writing which has been deemed the most complex genre for learners to master) in order to understand the complexities of constructing an essay in a cohesive way, as they need to consider multiple aspects of writing, such as the linguistic features, rhetorical features and structural features of the genre and unify them into a sound argument. This takes time, practice and revision, and extensive feedback is required. The process-genre approach proved to be successful in this study, as leamers showed remarkable improvements in their writing from the initial stages of writing to the final drafts of their essays. The findings revealed that explicit teaching of genres and structural elements of writing is vital for ensuring learners' development. Learners require modelling of the genre, scaffolding and careful guidance through step-by-step processes in order to build confidence and express their ideas effectively in written text. The findings indicate the relevance of using the process-genre approach for teaching and learning and that teaching and learning writing is indeed a process that needs more time and practice that is cUiTently allocated in the curriculum.
- Full Text:
- Date Issued: 2012
- Authors: Elson, Jillian Margaret
- Date: 2012
- Subjects: English language -- Rhetoric -- Study and teaching (Secondary) English language -- Writing -- Study and teaching (Secondary) Written communication
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1714 , http://hdl.handle.net/10962/d1003597
- Description: This action research study aimed to improve teaching and learning of argumentative writing through a process-genre approach. Learners were carefully guided through the processes of writing the argumentative genre, with the focus being on teaching of the genre and on the structural conventions of writing arguments. Participants were a class of grade nine learners who speak English as a first language. They were chosen for this study as Grade Nine is a crucial year for writing development before learners enter the senior phase and are met with heightened expectations in the curriculum, that often they struggle to meet, as their writing has not been sufficiently developed to an academic level. The focus of writing in Grade Nine is on narrative and prose, so this writing intervention, in which a teaching module was developed in collaboration with the 1eamers, aimed to broaden their writing skills and provide them with a head start in leaming the fine art of argumentation, as this is a useful skill to acquire for purposes even beyond the classroom. Genre theorists advocate the importance of teaching genres to leamers at a young age, as it allows them access into different communities of discourse, as they become aware and understand the conventions held by a patiicular community, and realize the purpose of different styles of writing for effectively communicating, which prepares them to meet the expectations of their audience. Teaching the structures of different genres therefore allows the writer, and the audience, a framework for understanding the text. The process approach has been widely used by educators as it focuses on explicit teaching of writing processes that are fundamental to leamers' development in writing. Learners need to be carefully guided from the initial stages, to the more complex stages (especially in argumentative writing which has been deemed the most complex genre for learners to master) in order to understand the complexities of constructing an essay in a cohesive way, as they need to consider multiple aspects of writing, such as the linguistic features, rhetorical features and structural features of the genre and unify them into a sound argument. This takes time, practice and revision, and extensive feedback is required. The process-genre approach proved to be successful in this study, as leamers showed remarkable improvements in their writing from the initial stages of writing to the final drafts of their essays. The findings revealed that explicit teaching of genres and structural elements of writing is vital for ensuring learners' development. Learners require modelling of the genre, scaffolding and careful guidance through step-by-step processes in order to build confidence and express their ideas effectively in written text. The findings indicate the relevance of using the process-genre approach for teaching and learning and that teaching and learning writing is indeed a process that needs more time and practice that is cUiTently allocated in the curriculum.
- Full Text:
- Date Issued: 2012
The role of Hsp90/Hsp70 organising protein (Hop) in the Proliferation, Survival and Migration of Breast Cancer Cells.
- Authors: Willmer, Tarryn
- Date: 2012
- Subjects: Cancer -- Treatment , Heat shock proteins , Cancer cells , Breast -- Cancer
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4130 , http://hdl.handle.net/10962/d1015720
- Description: Hop (the Hsp90/Hsp70 organising protein) is a co-chaperone that acts as an adapter between the major molecular chaperones Hsp90 and Hsp70 during the cellular assembly of the Hsp90 complex. The Hsp90 complex regulates the stability and conformational maturation of a range of important cellular proteins, many of which are deregulated in cancer. In this study, we hypothesised that Hop knockdown inhibits proliferation and migration of cancer cells. We characterised the expression of Hop in cell models of different cancerous status, and provided evidence that Hop was upregulated in tumour cells compared to normal cell counterparts. Using an RNA interference approach, a 60-90% knockdown of Hop was achieved for up to 144 hours in the MDA-MB-231 and Hs578T breast cancer cell lines. Hop knockdown resulted in downregulation of the Hsp90 client proteins, Akt and Stat3, as well as a change in the expression of other Hsp90 co-chaperones, p23, Cdc37 and Aha1, while no change in the levels of Hsp90 or Hsp70 was observed. Silencing of Hop impaired cell proliferation in Hs578T cells but an increase in proliferation in MDA-MB-231, suggesting that the role of Hop in cancer cell proliferation was dependent on type of cancer cell. Hop knockdown in Hs578T and MDA-MB- 231 cells did not lead to any significant changes in the half maximal inhibitory concentrations (IC50) of selected small molecule inhibitors (paclitaxel, geldanamycin and novobiocin) in these cell lines after 72 hours. Hop knockdown cells were however, more sensitive than control cells to the Hsp90 inhibitors geldanamycin and novobiocin at earlier time points and in the presence of the drug transporter inhibitor, verapamil. Hop knockdown caused a decrease in cell migration as measured by the wound healing assay in both Hs578T and MDA-MB-231 cells. Hop was present in purified pseudopodia fractions of migrating cells, and immunofluorescence analysis showed that Hop colocalised with actin at the leading edges of pseudopodia, points of adhesion and at intercellular junctions of cells that have been stimulated to migrate with the chemokine stromal derived factor-1. Hop was able to bind to actin in vitro using actin cosedimentation assays, and silencing of Hop dramatically reduced the capacity of Hs578T cells to form pseudopodia. These results establish a correlation between Hop and actin dynamics, pseudopodia formation and migration in the context of Hop silencing, and collectively suggest that Hop plays a role in cancer cell migration. This study presents experimental evidence for a promising alternative to targeting Hsp90 and Hsp70 chaperones, a novel drug target in cancer therapy.
- Full Text:
- Date Issued: 2012
- Authors: Willmer, Tarryn
- Date: 2012
- Subjects: Cancer -- Treatment , Heat shock proteins , Cancer cells , Breast -- Cancer
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4130 , http://hdl.handle.net/10962/d1015720
- Description: Hop (the Hsp90/Hsp70 organising protein) is a co-chaperone that acts as an adapter between the major molecular chaperones Hsp90 and Hsp70 during the cellular assembly of the Hsp90 complex. The Hsp90 complex regulates the stability and conformational maturation of a range of important cellular proteins, many of which are deregulated in cancer. In this study, we hypothesised that Hop knockdown inhibits proliferation and migration of cancer cells. We characterised the expression of Hop in cell models of different cancerous status, and provided evidence that Hop was upregulated in tumour cells compared to normal cell counterparts. Using an RNA interference approach, a 60-90% knockdown of Hop was achieved for up to 144 hours in the MDA-MB-231 and Hs578T breast cancer cell lines. Hop knockdown resulted in downregulation of the Hsp90 client proteins, Akt and Stat3, as well as a change in the expression of other Hsp90 co-chaperones, p23, Cdc37 and Aha1, while no change in the levels of Hsp90 or Hsp70 was observed. Silencing of Hop impaired cell proliferation in Hs578T cells but an increase in proliferation in MDA-MB-231, suggesting that the role of Hop in cancer cell proliferation was dependent on type of cancer cell. Hop knockdown in Hs578T and MDA-MB- 231 cells did not lead to any significant changes in the half maximal inhibitory concentrations (IC50) of selected small molecule inhibitors (paclitaxel, geldanamycin and novobiocin) in these cell lines after 72 hours. Hop knockdown cells were however, more sensitive than control cells to the Hsp90 inhibitors geldanamycin and novobiocin at earlier time points and in the presence of the drug transporter inhibitor, verapamil. Hop knockdown caused a decrease in cell migration as measured by the wound healing assay in both Hs578T and MDA-MB-231 cells. Hop was present in purified pseudopodia fractions of migrating cells, and immunofluorescence analysis showed that Hop colocalised with actin at the leading edges of pseudopodia, points of adhesion and at intercellular junctions of cells that have been stimulated to migrate with the chemokine stromal derived factor-1. Hop was able to bind to actin in vitro using actin cosedimentation assays, and silencing of Hop dramatically reduced the capacity of Hs578T cells to form pseudopodia. These results establish a correlation between Hop and actin dynamics, pseudopodia formation and migration in the context of Hop silencing, and collectively suggest that Hop plays a role in cancer cell migration. This study presents experimental evidence for a promising alternative to targeting Hsp90 and Hsp70 chaperones, a novel drug target in cancer therapy.
- Full Text:
- Date Issued: 2012
An investigation into the benefits of integrating learners' prior everyday knowledge and experiences during teaching and learning of acids and bases in Grade 7: a case study
- Authors: Kuhlane, Zukiswa
- Date: 2012
- Subjects: Science -- Study and teaching (Primary) -- Research -- South Africa Prior learning -- South Africa Limited English-proficient students -- Education (Primary) -- South Africa Teaching -- Aids and devices -- Research
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1602 , http://hdl.handle.net/10962/d1003484
- Description: This study was conducted at a school designated as a higher primary school comprised of grade 0-9 learners (GET band) in Grahamstown in the Eastern Cape, South Africa. With the advent of the new curriculum in South Africa, we are also grappling with the implementation of the new curriculum at this school. This motivated me to investigate the benefits of eliciting and integrating learners’ prior everyday knowledge and experiences during teaching and learning of acids and bases. Essentially, the study sought to gain insight into whether engaging learners during practical activities using easily accessible materials from their homes facilitated meaning-making of acids and bases. This study is located within an interpretive paradigm. Within this paradigm, a qualitative case study approach was conducted with the researcher’s Grade 7 class. To gather data, document analysis, semi-structured interviews, questionnaires, lesson observations, stimulated recall discussions while watching the videotaped lessons as well as focus group interviews with learners were used. An inductive analysis to discover patterns and themes was applied during the data analysis process. The validation process was done through watching the videotaped lessons with the teachers who observed the lessons. Also, transcripts of the interviews and a summary of discussions were given back to the respondents to verify their responses and check for any misinterpretations. Rich data sets were analysed in relation to the research questions which were: How do Natural Sciences teachers elicit and integrate learners’ prioreveryday knowledge and experiences to facilitate learning of scientific concepts of acids and bases in their classrooms? Does engaging learners in practical activities using everyday substances enhance their conceptual development and understanding of acids and bases? The findings from the study revealed that the use of learners’ prior everyday knowledge and experiences during teaching and learning of acids and bases facilitated meaningful learning. Furthermore, linking learning to learners’ everyday experiences enabled them to learn scientific concepts in a relaxed and non-threatening environment. It is thus recommended that teachers should be supported in their endeavours to incorporate learners’ real life experiences during their teaching and learning repertoires. Notwithstanding, as much as there were benefits in this study there were, however, also some challenges that were encountered, such as language, which warrants further research.
- Full Text:
- Date Issued: 2012
- Authors: Kuhlane, Zukiswa
- Date: 2012
- Subjects: Science -- Study and teaching (Primary) -- Research -- South Africa Prior learning -- South Africa Limited English-proficient students -- Education (Primary) -- South Africa Teaching -- Aids and devices -- Research
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1602 , http://hdl.handle.net/10962/d1003484
- Description: This study was conducted at a school designated as a higher primary school comprised of grade 0-9 learners (GET band) in Grahamstown in the Eastern Cape, South Africa. With the advent of the new curriculum in South Africa, we are also grappling with the implementation of the new curriculum at this school. This motivated me to investigate the benefits of eliciting and integrating learners’ prior everyday knowledge and experiences during teaching and learning of acids and bases. Essentially, the study sought to gain insight into whether engaging learners during practical activities using easily accessible materials from their homes facilitated meaning-making of acids and bases. This study is located within an interpretive paradigm. Within this paradigm, a qualitative case study approach was conducted with the researcher’s Grade 7 class. To gather data, document analysis, semi-structured interviews, questionnaires, lesson observations, stimulated recall discussions while watching the videotaped lessons as well as focus group interviews with learners were used. An inductive analysis to discover patterns and themes was applied during the data analysis process. The validation process was done through watching the videotaped lessons with the teachers who observed the lessons. Also, transcripts of the interviews and a summary of discussions were given back to the respondents to verify their responses and check for any misinterpretations. Rich data sets were analysed in relation to the research questions which were: How do Natural Sciences teachers elicit and integrate learners’ prioreveryday knowledge and experiences to facilitate learning of scientific concepts of acids and bases in their classrooms? Does engaging learners in practical activities using everyday substances enhance their conceptual development and understanding of acids and bases? The findings from the study revealed that the use of learners’ prior everyday knowledge and experiences during teaching and learning of acids and bases facilitated meaningful learning. Furthermore, linking learning to learners’ everyday experiences enabled them to learn scientific concepts in a relaxed and non-threatening environment. It is thus recommended that teachers should be supported in their endeavours to incorporate learners’ real life experiences during their teaching and learning repertoires. Notwithstanding, as much as there were benefits in this study there were, however, also some challenges that were encountered, such as language, which warrants further research.
- Full Text:
- Date Issued: 2012
Rapid enzymatic detection of organophosphorous and carbamate pesticides in water
- Authors: Mwila, Katayi
- Date: 2012
- Subjects: Organophosphorus compounds , Carbamates , Water -- Pesticide content -- South Africa -- Eastern Cape , Water quality biological assessment -- South Africa -- Eastern Cape , Water quality management -- South Africa -- Eastern Cape , Pesticides -- Toxicology -- South Africa -- Eastern Cape , Biological assay , Acetylcholinesterase , Parathion , Aldicarb , Carbaryl , Carbofuran , Nitrophenols
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4024 , http://hdl.handle.net/10962/d1004084 , Organophosphorus compounds , Carbamates , Water -- Pesticide content -- South Africa -- Eastern Cape , Water quality biological assessment -- South Africa -- Eastern Cape , Water quality management -- South Africa -- Eastern Cape , Pesticides -- Toxicology -- South Africa -- Eastern Cape , Biological assay , Acetylcholinesterase , Parathion , Aldicarb , Carbaryl , Carbofuran , Nitrophenols
- Description: The increased use of pesticides has resulted in a corresponding increase in concern for the effect they may have on the health of humans and other non-target organisms. The two main areas of concern are the toxicological effects that mixtures of pesticides may have as well as the endocrine disrupting effects. Although the individual pesticides may be present at concentrations below the levels deemed to be detrimental to health, it has been argued that their combined effect may still result in elevated health risks. Another important aspect of pesticide risk assessment requires a consideration of the breakdown products of pesticides and their effect on human health. There has been very little research into the effects of degradation products and this issue should be addressed as these could potentially pose a higher risk than their parent compounds. One of the most important bio-markers available for use is the ubiquitous enzyme acetylcholinesterase (AChE). This enzyme is responsible for one of the most important functions in the body; namely nerve impulse transmission, upon which all life depends. The inhibition of this enzyme indicates toxicity and as a subsequence, a threat to the organism’s well-being. Bioassays have also recently been developed to test chemicals for endocrine disrupting effects. These tests rely on a dose response equivalent to that of the most potent well known estrogen 17-β estradiol. Any chemical that has a measurable response is deemed to display endocrine disrupting effects. This first aim of this study was to investigate the toxicological and endocrine disrupting effects of three organophosphorus pesticides; aldicarb, parathion and demeton-S-methyl, in addition to two breakdown products; aminophenol and p-nitrophenol. Two carbamate pesticides; carbaryl and carbofuran were also analysed. The toxicological effects of mixtures of the parent pesticide compounds were tested to assess if any antagonistic, additive or synergistic effects were observed. This data was then used in conjunction with an artificial neural network to assess if individual pesticides could be distinguished from mixtures of pesticides. A final objective was to sample various Eastern Cape water sources, utilising the enzymatic assay to determine the presence of any of these pesticides in these samples. There were several conclusions drawn from this study. AChE was successfully used as an assay to test the toxicity of the pesticides under investigation, based on their inhibition of this enzyme. An important factor for consideration throughout the study was the need to establish basal and monitor AChE activity (i.e. the need to monitor AChE activity in the absence of any pesticide). This ensured accurate comparison of the results obtained. It was found that demeton-S-methyl was the most potent of these pesticides followed by carbaryl, parathion, aldicarb and finally carbofuran, and that carbofuran could potentiate AChE. The results indicated that pesticide mixtures generally exhibited an additive inhibitory effect on AChE, although at some concentrations of pesticides, synergistic and antagonistic effects were noted. From the data using mixtures of pesticides, a feed forward neural network was created that was successfully able to distinguish individual pesticides from mixtures within its training parameters. None of the pesticides tested displayed endocrine disrupting properties in the Yeast Estrogen Screen (YES), T47D-KBluc and MDA-kb2 bio-assays. Other studies reported mixed results in this regard and thus no final conclusions could be drawn. The Blaauwkrantz River, Kariega River, Sundays River, Swartkops River and Kowie River were all tested for pesticides and although positive results were recorded, conventional methods indicated that there were no pesticides in the rivers. There were, however, trace metals present which are known to inhibit AChE, thus causing a false positive result. These results indicated that AChE can be used as a high throughput initial pre-screening tool, but that it cannot serve as a substitute for more accurate conventional testing methods.
- Full Text:
- Date Issued: 2012
- Authors: Mwila, Katayi
- Date: 2012
- Subjects: Organophosphorus compounds , Carbamates , Water -- Pesticide content -- South Africa -- Eastern Cape , Water quality biological assessment -- South Africa -- Eastern Cape , Water quality management -- South Africa -- Eastern Cape , Pesticides -- Toxicology -- South Africa -- Eastern Cape , Biological assay , Acetylcholinesterase , Parathion , Aldicarb , Carbaryl , Carbofuran , Nitrophenols
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4024 , http://hdl.handle.net/10962/d1004084 , Organophosphorus compounds , Carbamates , Water -- Pesticide content -- South Africa -- Eastern Cape , Water quality biological assessment -- South Africa -- Eastern Cape , Water quality management -- South Africa -- Eastern Cape , Pesticides -- Toxicology -- South Africa -- Eastern Cape , Biological assay , Acetylcholinesterase , Parathion , Aldicarb , Carbaryl , Carbofuran , Nitrophenols
- Description: The increased use of pesticides has resulted in a corresponding increase in concern for the effect they may have on the health of humans and other non-target organisms. The two main areas of concern are the toxicological effects that mixtures of pesticides may have as well as the endocrine disrupting effects. Although the individual pesticides may be present at concentrations below the levels deemed to be detrimental to health, it has been argued that their combined effect may still result in elevated health risks. Another important aspect of pesticide risk assessment requires a consideration of the breakdown products of pesticides and their effect on human health. There has been very little research into the effects of degradation products and this issue should be addressed as these could potentially pose a higher risk than their parent compounds. One of the most important bio-markers available for use is the ubiquitous enzyme acetylcholinesterase (AChE). This enzyme is responsible for one of the most important functions in the body; namely nerve impulse transmission, upon which all life depends. The inhibition of this enzyme indicates toxicity and as a subsequence, a threat to the organism’s well-being. Bioassays have also recently been developed to test chemicals for endocrine disrupting effects. These tests rely on a dose response equivalent to that of the most potent well known estrogen 17-β estradiol. Any chemical that has a measurable response is deemed to display endocrine disrupting effects. This first aim of this study was to investigate the toxicological and endocrine disrupting effects of three organophosphorus pesticides; aldicarb, parathion and demeton-S-methyl, in addition to two breakdown products; aminophenol and p-nitrophenol. Two carbamate pesticides; carbaryl and carbofuran were also analysed. The toxicological effects of mixtures of the parent pesticide compounds were tested to assess if any antagonistic, additive or synergistic effects were observed. This data was then used in conjunction with an artificial neural network to assess if individual pesticides could be distinguished from mixtures of pesticides. A final objective was to sample various Eastern Cape water sources, utilising the enzymatic assay to determine the presence of any of these pesticides in these samples. There were several conclusions drawn from this study. AChE was successfully used as an assay to test the toxicity of the pesticides under investigation, based on their inhibition of this enzyme. An important factor for consideration throughout the study was the need to establish basal and monitor AChE activity (i.e. the need to monitor AChE activity in the absence of any pesticide). This ensured accurate comparison of the results obtained. It was found that demeton-S-methyl was the most potent of these pesticides followed by carbaryl, parathion, aldicarb and finally carbofuran, and that carbofuran could potentiate AChE. The results indicated that pesticide mixtures generally exhibited an additive inhibitory effect on AChE, although at some concentrations of pesticides, synergistic and antagonistic effects were noted. From the data using mixtures of pesticides, a feed forward neural network was created that was successfully able to distinguish individual pesticides from mixtures within its training parameters. None of the pesticides tested displayed endocrine disrupting properties in the Yeast Estrogen Screen (YES), T47D-KBluc and MDA-kb2 bio-assays. Other studies reported mixed results in this regard and thus no final conclusions could be drawn. The Blaauwkrantz River, Kariega River, Sundays River, Swartkops River and Kowie River were all tested for pesticides and although positive results were recorded, conventional methods indicated that there were no pesticides in the rivers. There were, however, trace metals present which are known to inhibit AChE, thus causing a false positive result. These results indicated that AChE can be used as a high throughput initial pre-screening tool, but that it cannot serve as a substitute for more accurate conventional testing methods.
- Full Text:
- Date Issued: 2012
The effect of dietary fish oil replacement with soybean oil on growth and health of dusky kob, Argyrosomus japonicus (Pisces: Sciaenidae)
- Authors: Rossetti, Nani Adami
- Date: 2012
- Subjects: Sciaenidae , Fish culture , Argyrosomus -- Growth , Argyrosomus -- Feeding and feeds , Argyrosomus -- Health , Fish oils as feed , Soy oil , Lipids , Eicosapentaenoic acid , Docosahexaenoic acid
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5272 , http://hdl.handle.net/10962/d1005116 , Sciaenidae , Fish culture , Argyrosomus -- Growth , Argyrosomus -- Feeding and feeds , Argyrosomus -- Health , Fish oils as feed , Soy oil , Lipids , Eicosapentaenoic acid , Docosahexaenoic acid
- Description: Lipids are essential components for fish because they contain fatty acids that are vital for regular growth and health. Fish oil is rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are essential fatty acids for carnivorous fish, and therefore this product has traditionally been used as the main source of lipids in fish feeds. However, with declining fisheries resources worldwide and the rapid expansion of the aquaculture industry pressuring this finite resource, such ingredients are becoming less available and more expensive. It is therefore necessary to explore the utilization of ingredients that are sustainable and competitive alternatives to fish oil in marine finfish feeds. This work investigated the effects of the substitution of fish oil with soybean oil on the growth performance, feed efficiency, fatty acid composition of the liver tissue and some health parameters in juvenile dusky kob, Argyrosomus japonicus; an increasingly popular sciaenid marine aquaculture species in South Africa. Six diets (18 % total lipid and 46 % protein) with increasing percentage substitution of fish oil with soybean oil (1, 14, 28, 42, 56 and 70 %) were fed to juvenile kob. After 84 days of feeding these diets to the fish, no significant differences in fish length and weight between treatments were observed. However, there was a significant trend of a decrease in specific growth rate, ranging from (± standard error) 0.87 ± 0.06 to 0.72 ± 0.04 % body weight day⁻¹, and condition factor, ranging from 1.59 ± 0.03 to 1.54 ± 0.02, with increasing vegetable oil replacement in the diets between days 56 and 84. There were no differences in red blood cell count, haematocrit and haemoglobin concentration after 206 days of feeding. However, visceral fat index (VFI) increased significantly from 1.08 ± 0.17 % for fish fed diets with 28 % soybean oil, to 2.24 ± 0.15 % for fish fed diets with 70 % soybean oil. Similarly, hepatosomatic index (HSI) increased significantly from 0.84 ± 0.08 % to 1.80 ± 0.12 % in the control diet and the 56 % soybean oil diet, respectively. After 206 days of feeding, fish fed diets with 42 to 70 % soybean oil showed greater number of lipid vacuoles in the liver, which were also larger in size, and hepatocytes nuclei were displaced to the cell periphery. The fatty acid composition of the liver tissue strongly corresponded to the fatty acid composition of the diets. Linoleic acid accumulated in the liver of the fish fed increasing soybean oil in the diets. In contrast, EPA and DHA decreased from 13.63 to 1.97 %, and 14.34 to 3.28 %, respectively, in the liver tissue of fish fed diets with increasing soybean oil content; consequently the n-3/n-6 ratio was also significantly reduced with inclusion of vegetable oil in the diets. The trend of decreasing growth rate with increasing oil replacement towards the end of the trial corresponds with increases in VFI, HSI, as well as the fatty acid accumulation and lipid vacuoles in the liver. This suggests that dusky kob is less able to metabolise soybean oil at increased substitution levels which would account for the poorer growth at higher levels. The dependence of fish on dietary marine oil decreased significantly with each inclusion of soybean oil in the diets. Nonetheless, the calculations based on the nutrient ratio presented positive outcomes for all treatments, that is, values of marine oil dependency ratio were below one for all treatments. It is concluded that soybean oil can replace fish oil in formulated diets for dusky kob up to a level of 28 % of total dietary lipids, as evidenced by the good growth and feed efficiency, and no apparent negative health effects observed up to this level.
- Full Text:
- Date Issued: 2012
- Authors: Rossetti, Nani Adami
- Date: 2012
- Subjects: Sciaenidae , Fish culture , Argyrosomus -- Growth , Argyrosomus -- Feeding and feeds , Argyrosomus -- Health , Fish oils as feed , Soy oil , Lipids , Eicosapentaenoic acid , Docosahexaenoic acid
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5272 , http://hdl.handle.net/10962/d1005116 , Sciaenidae , Fish culture , Argyrosomus -- Growth , Argyrosomus -- Feeding and feeds , Argyrosomus -- Health , Fish oils as feed , Soy oil , Lipids , Eicosapentaenoic acid , Docosahexaenoic acid
- Description: Lipids are essential components for fish because they contain fatty acids that are vital for regular growth and health. Fish oil is rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are essential fatty acids for carnivorous fish, and therefore this product has traditionally been used as the main source of lipids in fish feeds. However, with declining fisheries resources worldwide and the rapid expansion of the aquaculture industry pressuring this finite resource, such ingredients are becoming less available and more expensive. It is therefore necessary to explore the utilization of ingredients that are sustainable and competitive alternatives to fish oil in marine finfish feeds. This work investigated the effects of the substitution of fish oil with soybean oil on the growth performance, feed efficiency, fatty acid composition of the liver tissue and some health parameters in juvenile dusky kob, Argyrosomus japonicus; an increasingly popular sciaenid marine aquaculture species in South Africa. Six diets (18 % total lipid and 46 % protein) with increasing percentage substitution of fish oil with soybean oil (1, 14, 28, 42, 56 and 70 %) were fed to juvenile kob. After 84 days of feeding these diets to the fish, no significant differences in fish length and weight between treatments were observed. However, there was a significant trend of a decrease in specific growth rate, ranging from (± standard error) 0.87 ± 0.06 to 0.72 ± 0.04 % body weight day⁻¹, and condition factor, ranging from 1.59 ± 0.03 to 1.54 ± 0.02, with increasing vegetable oil replacement in the diets between days 56 and 84. There were no differences in red blood cell count, haematocrit and haemoglobin concentration after 206 days of feeding. However, visceral fat index (VFI) increased significantly from 1.08 ± 0.17 % for fish fed diets with 28 % soybean oil, to 2.24 ± 0.15 % for fish fed diets with 70 % soybean oil. Similarly, hepatosomatic index (HSI) increased significantly from 0.84 ± 0.08 % to 1.80 ± 0.12 % in the control diet and the 56 % soybean oil diet, respectively. After 206 days of feeding, fish fed diets with 42 to 70 % soybean oil showed greater number of lipid vacuoles in the liver, which were also larger in size, and hepatocytes nuclei were displaced to the cell periphery. The fatty acid composition of the liver tissue strongly corresponded to the fatty acid composition of the diets. Linoleic acid accumulated in the liver of the fish fed increasing soybean oil in the diets. In contrast, EPA and DHA decreased from 13.63 to 1.97 %, and 14.34 to 3.28 %, respectively, in the liver tissue of fish fed diets with increasing soybean oil content; consequently the n-3/n-6 ratio was also significantly reduced with inclusion of vegetable oil in the diets. The trend of decreasing growth rate with increasing oil replacement towards the end of the trial corresponds with increases in VFI, HSI, as well as the fatty acid accumulation and lipid vacuoles in the liver. This suggests that dusky kob is less able to metabolise soybean oil at increased substitution levels which would account for the poorer growth at higher levels. The dependence of fish on dietary marine oil decreased significantly with each inclusion of soybean oil in the diets. Nonetheless, the calculations based on the nutrient ratio presented positive outcomes for all treatments, that is, values of marine oil dependency ratio were below one for all treatments. It is concluded that soybean oil can replace fish oil in formulated diets for dusky kob up to a level of 28 % of total dietary lipids, as evidenced by the good growth and feed efficiency, and no apparent negative health effects observed up to this level.
- Full Text:
- Date Issued: 2012
The feeding and spatial ecology of cheetahs (Acinonyx jubatus) and lions (Panthera leo) in the Little Karoo, South Africa
- Authors: Vorster, Paul Hendrik
- Date: 2012
- Subjects: Sanbona Wildlife Reserve , Cheetah -- South Africa -- Little Karoo , Lion -- South Africa -- Little Karoo , Cheetah -- Behavior -- South Africa -- Little Karoo , Lion -- Behavior -- South Africa -- Little Karoo , Cheetah -- Food -- South Africa -- Little Karoo , Lion -- Food -- South Africa -- Little Karoo , Spatial behavior in animals , Predation (Biology) , Game reserves -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5693 , http://hdl.handle.net/10962/d1005379 , Sanbona Wildlife Reserve , Cheetah -- South Africa -- Little Karoo , Lion -- South Africa -- Little Karoo , Cheetah -- Behavior -- South Africa -- Little Karoo , Lion -- Behavior -- South Africa -- Little Karoo , Cheetah -- Food -- South Africa -- Little Karoo , Lion -- Food -- South Africa -- Little Karoo , Spatial behavior in animals , Predation (Biology) , Game reserves -- Management
- Description: The re-introduction of large carnivores into relatively small conservation areas that fall within the historic distribution range of the species is becoming an increasingly common occurrence. The success of such re-introductions depends very much on the quality of the information that is available to guide management decisions, but in many cases, little information is available. The re-introduction of lions and cheetahs to Sanbona created the opportunity to monitor the behaviour of re-introduced predators to a relatively large system that was characterised by a low ungulate stocking density and little standing water. The broad aims were to study the feeding and spatial ecologies of the lions and cheetahs, to collect standard base-line data, and to examine the effects of the low prey density and limited standing water on habitat selection, range size and diet. The diet (data collected from direct observation and faecal analysis) was similar to that reported in previous studies, and lions and cheetahs preferred greater kudu, black wildebeest and springbok. Lions preferred medium to large prey items, and cheetahs preferred medium to small prey items. The hilly and mountainous terrain of much of the reserve meant that only 50% of the total space was available to the predators. Home ranges of most of the predators were focused around the single large body of standing water. This is likely to have been a response to the water, the vegetation, and the prey that was attracted to these. Habitat selection was also influenced by inter and intra-specific interactions at least for a solitary male lion and female cheetahs. Range sizes were larger than on some other reserves and it is suggested that this was a result of the low prey density. These results form the basis for management recommendations including the importance of continuing to monitor the system and opening up additional parts of the reserve to the predators.
- Full Text:
- Date Issued: 2012
- Authors: Vorster, Paul Hendrik
- Date: 2012
- Subjects: Sanbona Wildlife Reserve , Cheetah -- South Africa -- Little Karoo , Lion -- South Africa -- Little Karoo , Cheetah -- Behavior -- South Africa -- Little Karoo , Lion -- Behavior -- South Africa -- Little Karoo , Cheetah -- Food -- South Africa -- Little Karoo , Lion -- Food -- South Africa -- Little Karoo , Spatial behavior in animals , Predation (Biology) , Game reserves -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5693 , http://hdl.handle.net/10962/d1005379 , Sanbona Wildlife Reserve , Cheetah -- South Africa -- Little Karoo , Lion -- South Africa -- Little Karoo , Cheetah -- Behavior -- South Africa -- Little Karoo , Lion -- Behavior -- South Africa -- Little Karoo , Cheetah -- Food -- South Africa -- Little Karoo , Lion -- Food -- South Africa -- Little Karoo , Spatial behavior in animals , Predation (Biology) , Game reserves -- Management
- Description: The re-introduction of large carnivores into relatively small conservation areas that fall within the historic distribution range of the species is becoming an increasingly common occurrence. The success of such re-introductions depends very much on the quality of the information that is available to guide management decisions, but in many cases, little information is available. The re-introduction of lions and cheetahs to Sanbona created the opportunity to monitor the behaviour of re-introduced predators to a relatively large system that was characterised by a low ungulate stocking density and little standing water. The broad aims were to study the feeding and spatial ecologies of the lions and cheetahs, to collect standard base-line data, and to examine the effects of the low prey density and limited standing water on habitat selection, range size and diet. The diet (data collected from direct observation and faecal analysis) was similar to that reported in previous studies, and lions and cheetahs preferred greater kudu, black wildebeest and springbok. Lions preferred medium to large prey items, and cheetahs preferred medium to small prey items. The hilly and mountainous terrain of much of the reserve meant that only 50% of the total space was available to the predators. Home ranges of most of the predators were focused around the single large body of standing water. This is likely to have been a response to the water, the vegetation, and the prey that was attracted to these. Habitat selection was also influenced by inter and intra-specific interactions at least for a solitary male lion and female cheetahs. Range sizes were larger than on some other reserves and it is suggested that this was a result of the low prey density. These results form the basis for management recommendations including the importance of continuing to monitor the system and opening up additional parts of the reserve to the predators.
- Full Text:
- Date Issued: 2012
Environmental factors influencing learner absenteeism in six schools in the Kavango Region, Namibia
- Authors: Sanzila, Keith Mumba
- Date: 2012
- Subjects: School attendance -- Namibia -- Kavango Education -- Namibia -- Kavango Education and state -- Namibia -- Kavango Education -- Social aspects -- Namibia -- Kavango High school students -- Namibia -- Kavango -- Attitudes High school students -- Namibia -- Kavango -- Social conditions
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1516 , http://hdl.handle.net/10962/d1003398
- Description: This study on learner absenteeism takes place in the Namibian context with a focus on the Kavango region, located in Northern Namibia, where absenteeism has been identified as a problem. The intention of the study is to find out the relationship between learner absenteeism and environmental factors. The research question was framed as: How do environmental factors influence learner absenteeism in schools, conceptualised as human activity systems in the Kavango Region (Namibia)? The wider intention of this study is to inform processes that can be put in place to reduce the impact of environmental factors on learner absenteeism, with the ultimate view of improving the quality of education. The literature review provides insight into learner absenteeism in developing and developed nations. It outlines the Namibian policies developed for improving learner attendance and retention of learners in schools, with the view of improving access to school. The study is located within the broader goals of education of Namibia. The research adopts a qualitative interpretive approach, and focuses on environmental factors influencing learner absenteeism in six case studies, which are selected schools in the Kavango province. The study uses a variety of tools such as questionnaires, focus group interviews, observations and interviews as well as document analysis. It uses a combination of inductive and abductive modes of inference in the data analysis. It draws on systems thinking to develop a model that theorises the interrelated roles of different stakeholders, namely, learners, teachers, parents, educational officials (including the regional office and the Ministry of Education). It proposes possible strategies for reduction of learner absenteeism that could contribute towards the improvement of the quality of education. It also mentions the benefits of reducing learner absenteeism in the schools involved in the case study. The findings clearly show that poverty is the main environmental factor that influences learner attendance. The impact of poverty does not, however, occur in isolation; it interacts and has influence over other environmental factors such as alcohol abuse, sickness, lack of parental involvement, lack of motivation from stakeholders and household work. The study also found certain educational factors influenced learner absenteeism, such as teacher attitude, pedagogical styles, and lack of security. The study ends with recommendations to reduce learner absenteeism and recommendations for further research.
- Full Text:
- Date Issued: 2012
- Authors: Sanzila, Keith Mumba
- Date: 2012
- Subjects: School attendance -- Namibia -- Kavango Education -- Namibia -- Kavango Education and state -- Namibia -- Kavango Education -- Social aspects -- Namibia -- Kavango High school students -- Namibia -- Kavango -- Attitudes High school students -- Namibia -- Kavango -- Social conditions
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1516 , http://hdl.handle.net/10962/d1003398
- Description: This study on learner absenteeism takes place in the Namibian context with a focus on the Kavango region, located in Northern Namibia, where absenteeism has been identified as a problem. The intention of the study is to find out the relationship between learner absenteeism and environmental factors. The research question was framed as: How do environmental factors influence learner absenteeism in schools, conceptualised as human activity systems in the Kavango Region (Namibia)? The wider intention of this study is to inform processes that can be put in place to reduce the impact of environmental factors on learner absenteeism, with the ultimate view of improving the quality of education. The literature review provides insight into learner absenteeism in developing and developed nations. It outlines the Namibian policies developed for improving learner attendance and retention of learners in schools, with the view of improving access to school. The study is located within the broader goals of education of Namibia. The research adopts a qualitative interpretive approach, and focuses on environmental factors influencing learner absenteeism in six case studies, which are selected schools in the Kavango province. The study uses a variety of tools such as questionnaires, focus group interviews, observations and interviews as well as document analysis. It uses a combination of inductive and abductive modes of inference in the data analysis. It draws on systems thinking to develop a model that theorises the interrelated roles of different stakeholders, namely, learners, teachers, parents, educational officials (including the regional office and the Ministry of Education). It proposes possible strategies for reduction of learner absenteeism that could contribute towards the improvement of the quality of education. It also mentions the benefits of reducing learner absenteeism in the schools involved in the case study. The findings clearly show that poverty is the main environmental factor that influences learner attendance. The impact of poverty does not, however, occur in isolation; it interacts and has influence over other environmental factors such as alcohol abuse, sickness, lack of parental involvement, lack of motivation from stakeholders and household work. The study also found certain educational factors influenced learner absenteeism, such as teacher attitude, pedagogical styles, and lack of security. The study ends with recommendations to reduce learner absenteeism and recommendations for further research.
- Full Text:
- Date Issued: 2012