Cointegration in equity markets: a comparison between South African and major developed and emerging markets
- Authors: Petrov, Pavel
- Date: 2011
- Subjects: Cointegration Stock exchanges -- South Africa Stock exchanges -- Developing countries Stock exchanges -- Developed countries South Africa -- Economic conditions Portfolio management -- South Africa Econometrics Autoregression (Statistics)
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:5575 , http://hdl.handle.net/10962/d1005539
- Description: Cointegration has important implications for portfolio diversification. One of these is that in order to spread risk it is advisable to invest in markets that are not cointegrated. Over the last several decades communication technology has made the world a smaller place and hence cointegration in equity markets has become more prevalent. The bulk of research into cointegration focuses on developed and Asian markets, with little research been done on African markets. This study compares the Engle-Granger and Johansen tests for cointegration and uses them to calculate the level of cointegration between South African and other global equity markets. Each market is compared pair-wise with South Africa and the results have been that in general South Africa is cointegrated with other emerging markets but not really with African nor developed markets. Short-run analysis with the error correction was carried out and showed that in general markets respond slowly to any disequilibrium. Innovation accounting methods showed that the country placed first in Cholesky ordering dominates the other one. Multivariate cointegration was carried out using three selections of 4, 6 and 8 market portfolios. One of the markets was SA and the others were all chosen based on the criteria that they are not pair-wise cointegrated with SA. The level of cointegration varied depending on the portfolios, as did the error correction rates, impulse responses and variance decomposition. The one constant was that the USA dominated any portfolio where it was introduced. Recommendations were finally made about which market portfolio an investor should consider as most favourable.
- Full Text:
- Authors: Petrov, Pavel
- Date: 2011
- Subjects: Cointegration Stock exchanges -- South Africa Stock exchanges -- Developing countries Stock exchanges -- Developed countries South Africa -- Economic conditions Portfolio management -- South Africa Econometrics Autoregression (Statistics)
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:5575 , http://hdl.handle.net/10962/d1005539
- Description: Cointegration has important implications for portfolio diversification. One of these is that in order to spread risk it is advisable to invest in markets that are not cointegrated. Over the last several decades communication technology has made the world a smaller place and hence cointegration in equity markets has become more prevalent. The bulk of research into cointegration focuses on developed and Asian markets, with little research been done on African markets. This study compares the Engle-Granger and Johansen tests for cointegration and uses them to calculate the level of cointegration between South African and other global equity markets. Each market is compared pair-wise with South Africa and the results have been that in general South Africa is cointegrated with other emerging markets but not really with African nor developed markets. Short-run analysis with the error correction was carried out and showed that in general markets respond slowly to any disequilibrium. Innovation accounting methods showed that the country placed first in Cholesky ordering dominates the other one. Multivariate cointegration was carried out using three selections of 4, 6 and 8 market portfolios. One of the markets was SA and the others were all chosen based on the criteria that they are not pair-wise cointegrated with SA. The level of cointegration varied depending on the portfolios, as did the error correction rates, impulse responses and variance decomposition. The one constant was that the USA dominated any portfolio where it was introduced. Recommendations were finally made about which market portfolio an investor should consider as most favourable.
- Full Text:
Cointegration, causality and international portfolio diversification : investigating potential benefits to a South African investor
- Authors: Msimanga, Nkululeko Lwazi
- Date: 2011
- Subjects: Cointegration , Econometrics , International finance , Stock exchanges -- South Africa , Stock exchanges -- Developing countries , Stock exchanges -- Developed countries , Investments -- South Africa , Portfolio management -- South Africa , Investment analysis , Autoregression (Statistics)
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:962 , http://hdl.handle.net/10962/d1002696 , Cointegration , Econometrics , International finance , Stock exchanges -- South Africa , Stock exchanges -- Developing countries , Stock exchanges -- Developed countries , Investments -- South Africa , Portfolio management -- South Africa , Investment analysis , Autoregression (Statistics)
- Description: Research studies on portfolio diversification have tended to focus on developed markets and paid less attention to emerging markets. Traditionally, correlation analysis has been used to determine potential benefits from diversification but current studies have shifted focus from correlation analysis to exploring cointegration analysis and other forms of tests such as the Vector Error Correction Methodology. The research seeks to find if it is beneficial for a South African investor to diversify their portfolio of emerging market equities over a long-term period. Daily weighted share indices for the period of January 1996 to November 2008 were collected and analysed through the application of the Johansen cointegration technique and Vector Error Correction Methodology. Granger Causality tests were also performed to established whether one variable can be useful in forecasting another variable. The study found that there was at least one statistically significant long-run relationship between the emerging markets. After testing for unit roots for all the share indices and their first difference using the Augmented Dickey-Fuller test (ADF), Philips-Perron and Kwiatkowski, Phillips, Schmidt, and Shin (KPSS) unit root tests, similar conclusions were m~de. All the unit root tests and their levels could not be rejected for all the series. However, unit root tests on the first differences were rejected, meaning that all series are of order 1(1) - evidence of cointegration. Simply put, emerging markets tend not to drift apart over time. This suggests that emerging markets offer limited benefits to investors who are looking to add some risk to their portfolios. In addition, the study also found evidence of both unidirectional and bidirectional causality (Granger-Cause tests) between markets. This implies that the conditions for a particular market are exogenous of the other market. The study concludes that emerging markets are gradually adopting the same profile as developed markets.
- Full Text:
- Authors: Msimanga, Nkululeko Lwazi
- Date: 2011
- Subjects: Cointegration , Econometrics , International finance , Stock exchanges -- South Africa , Stock exchanges -- Developing countries , Stock exchanges -- Developed countries , Investments -- South Africa , Portfolio management -- South Africa , Investment analysis , Autoregression (Statistics)
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:962 , http://hdl.handle.net/10962/d1002696 , Cointegration , Econometrics , International finance , Stock exchanges -- South Africa , Stock exchanges -- Developing countries , Stock exchanges -- Developed countries , Investments -- South Africa , Portfolio management -- South Africa , Investment analysis , Autoregression (Statistics)
- Description: Research studies on portfolio diversification have tended to focus on developed markets and paid less attention to emerging markets. Traditionally, correlation analysis has been used to determine potential benefits from diversification but current studies have shifted focus from correlation analysis to exploring cointegration analysis and other forms of tests such as the Vector Error Correction Methodology. The research seeks to find if it is beneficial for a South African investor to diversify their portfolio of emerging market equities over a long-term period. Daily weighted share indices for the period of January 1996 to November 2008 were collected and analysed through the application of the Johansen cointegration technique and Vector Error Correction Methodology. Granger Causality tests were also performed to established whether one variable can be useful in forecasting another variable. The study found that there was at least one statistically significant long-run relationship between the emerging markets. After testing for unit roots for all the share indices and their first difference using the Augmented Dickey-Fuller test (ADF), Philips-Perron and Kwiatkowski, Phillips, Schmidt, and Shin (KPSS) unit root tests, similar conclusions were m~de. All the unit root tests and their levels could not be rejected for all the series. However, unit root tests on the first differences were rejected, meaning that all series are of order 1(1) - evidence of cointegration. Simply put, emerging markets tend not to drift apart over time. This suggests that emerging markets offer limited benefits to investors who are looking to add some risk to their portfolios. In addition, the study also found evidence of both unidirectional and bidirectional causality (Granger-Cause tests) between markets. This implies that the conditions for a particular market are exogenous of the other market. The study concludes that emerging markets are gradually adopting the same profile as developed markets.
- Full Text:
Community radio and museum outreach: a case study of community radio practices to inform the environment and sustainability programmes of Livingstone Museum
- Authors: Muloongo, Arthanitius Henry
- Date: 2011
- Subjects: Community radio -- Zambia Livingstone Museum Museum outreach programs -- Zambia Environmental education -- Zambia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1454 , http://hdl.handle.net/10962/d1003335
- Description: This is a qualitative study whose purpose was to investigate the community radio education practices and the museum outreach education activities with a view to understanding how a museum-radio partnership may be used to engage the Livingstone community in environment and sustainability learning. Environment and sustainability issues require a community approach in order to bring about sustained responses to environmental challenges. As such, the study worked with social learning ideas of engaging the community in environment and sustainability learning. The data was generated mainly from face-to-face semi-structured interviews involving three community radio stations, Radio Listener Clubs and museum experts. The data generated was then presented to a strategy workshop involving the Livingstone Museum and Radio Musi-otunya staff. Arising from this workshop, recommendations were made about the possibility of the museum working in partnership with the radio to engage the community in environmental education. The study has shown that much of the museum environmental education activities have been confined to exhibitions and lectures within the museum building, which has affected the number of people being serviced by the museum. These education activities are arranged such that museum expert-led knowledge is presented to the audience with minimal community engagement on the environmental learning content. The study has also shown that community radio programming provides opportunities for community-led social learning which the Livingstone Museum could make use of to engage the community in environmental learning. Community radio programming allows community participation through Radio Listener Clubs, in identification and presentation of local environmental issues. This makes it a suitable tool to address locally relevant environmental issues, by the local community. Environmental issues are different from one place to another. Therefore environmental education approaches that bring issues into the museum may fail to address the different environmental education issues in different community context. The study concludes by recommending that Livingstone Museum should explore the use of community radio so that their expert knowledge and that of the radio producers could be used to shape environmental education programmes to go beyond awareness-raising.
- Full Text:
- Authors: Muloongo, Arthanitius Henry
- Date: 2011
- Subjects: Community radio -- Zambia Livingstone Museum Museum outreach programs -- Zambia Environmental education -- Zambia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1454 , http://hdl.handle.net/10962/d1003335
- Description: This is a qualitative study whose purpose was to investigate the community radio education practices and the museum outreach education activities with a view to understanding how a museum-radio partnership may be used to engage the Livingstone community in environment and sustainability learning. Environment and sustainability issues require a community approach in order to bring about sustained responses to environmental challenges. As such, the study worked with social learning ideas of engaging the community in environment and sustainability learning. The data was generated mainly from face-to-face semi-structured interviews involving three community radio stations, Radio Listener Clubs and museum experts. The data generated was then presented to a strategy workshop involving the Livingstone Museum and Radio Musi-otunya staff. Arising from this workshop, recommendations were made about the possibility of the museum working in partnership with the radio to engage the community in environmental education. The study has shown that much of the museum environmental education activities have been confined to exhibitions and lectures within the museum building, which has affected the number of people being serviced by the museum. These education activities are arranged such that museum expert-led knowledge is presented to the audience with minimal community engagement on the environmental learning content. The study has also shown that community radio programming provides opportunities for community-led social learning which the Livingstone Museum could make use of to engage the community in environmental learning. Community radio programming allows community participation through Radio Listener Clubs, in identification and presentation of local environmental issues. This makes it a suitable tool to address locally relevant environmental issues, by the local community. Environmental issues are different from one place to another. Therefore environmental education approaches that bring issues into the museum may fail to address the different environmental education issues in different community context. The study concludes by recommending that Livingstone Museum should explore the use of community radio so that their expert knowledge and that of the radio producers could be used to shape environmental education programmes to go beyond awareness-raising.
- Full Text:
Comparative study of the feeding damage caused by the South African biotypes of the Russian wheat aphid (Diuraphis noxia Kurdjumov) on resistant and non-resistant lines of barley (Hordeum vulgare L.)
- Authors: Jimoh, Mahboob Adekilekun
- Date: 2011
- Subjects: Aphids Russian wheat aphid -- Research -- South Africa Barley -- Diseases and pests -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4201 , http://hdl.handle.net/10962/d1003770
- Description: Cereal crop productivity is hampered when these plants are infested by phloem feeding aphids. A great deal of research has been carried out with the direct aim of a clearer understanding of the mechanism involved in the interaction between aphids and their host plants. Research has directly or indirectly been geared towards enhanced plant productivity and achieving sustainable agriculture. Barley (Hordeum vulgare L.) is an important small grain crop in South Africa, whose crop performance is negatively affected by fluctuations in weather patterns as well as by agricultural pests. One of the insect pests infesting barley is the Russian wheat aphid, Diuraphis noxia Kurdjumov (RWA), of which the two South African biotypes, codenamed RWASA1 and RWASA2, were studied in this thesis. During dry spells, RWA infestation becomes a more serious threat to barley productivity. Resistant plants have been used to combat RWA infestation of small grains. In South Africa, 27 RWA-resistant wheat cultivars are currently used in commercial cultivation, but no resistant barley lines have, unfortunately, been developed, in spite of this grain’s significant economic importance. This informed the study in this thesis, and this interest particularly focussed on three RWA-resistant lines developed by the USDA, testing their performance against South African RWA biotypes, for possible adaptation to South Africa. The aim was thus to examine the plant-aphid interactions, aphid breeding rates, plant damage and sustainability, evidence of resistance or tolerance and finally potential performance under elevated CO2 (a very real climate change threat). Two major avenues of research were undertaken. The first aspect involved examination of structural and functional damage caused by RWASA1 and RWASA2 on the three resistant and a non-resistant line. Aphid population growth and damage symptoms (chlorosis and leaf roll) of infestation by these aphid biotypes were evaluated. This was followed by a structural and functional approach in which the effects of feeding on the transport systems (phloem and xylem) of barley were investigated. Fluorescence microscopy techniques (using aniline blue fluorochrome, a specific stain for callose and 5,6-CFDA, a phloem-mobile probe) were applied to investigate the feeding-related damage caused by the aphids, through an examination of wound callose formation and related to this, the resultant reduction in phloem transport capacity. Transmission electron microscopy (TEM) techniques provided evidence of the extent of the feeding-related cell damage. The second aspect involved a study of the effect of changing CO2 concentrations ([CO2]) on the resistant and susceptible barley cultivars to feeding by the two RWA biotypes. Leaves of plants grown at ambient and two elevated levels of [CO2] were analysed to investigate the effect of changing [CO2] on biomass, leaf nitrogen content and C:N ratio of control (uninfested) and infested plants. The population growth studies showed that the populations of the two RWA biotypes as well as bird cherry-oat aphid (BCA, Rhopalosiphum padi L.) increased substantially on the four barley lines. BCA was included here, as it had been the subject of several previous studies. RWASA2 bred faster than RWASA1 on all lines. The breeding rates of the two RWA biotypes were both suppressed and at near-equivalent levels on the three resistant lines, compared to the non-resistant PUMA. This suggests that the resistant lines possessed an antibiosis resistance mechanism against the feeding aphids. Feeding by the aphids manifested in morphological damage symptoms of chlorosis and leaf roll. The two biotypes inflicted severe chlorosis and leaf roll on the non-resistant PUMA. In the resistant plants, leaf rolling was more severe because of RWASA2 feeding compared to RWASA1 feeding. In contrast, chlorosis symptoms were more severe during RWASA1 feeding than was the case with RWASA2 feeding. Investigation of the effect of aphid feeding on the plants showed that callose was deposited within 24h and that this increased with longer feeding exposure. Wound callose distribution is more extensive in the non-resistant PUMA than in the resistant plants. RWASA2 feeding on the resistant lines caused deposition of more callose than was evident with RWASA1 feeding. During long-term feeding, it was evident that variation in the intensity and amount of wound callose was visible in the longitudinal and transverse veins of the resistant plants. Of the three STARS plants, STARS-9301B had the least callose. Interestingly, wound callose occurred in both resistant and non-resistant plants, in sharp contrast to what has been reported on resistant wheat cultivars that were developed in South Africa. The relative reduction in the wound callose deposited in the resistant line, when compared to the non-resistant lines, suggests the presence of a mechanism in the resistant lines, which may prevent excessive callose formation. Alternatively, the mechanism may stimulate callose breakdown. RWASA2 feeding on the resistant lines deposited more wound callose than RWASA1 feeding. This evidence supports the hypothesis that RWASA2 is a resistance breaking and more aggressive feeder than RWASA1 is; and further underscores the urgent need for development of RWA-resistant barley cultivars. The ultrastructural investigation of the feeding damage showed that the two biotypes caused extensive vascular damage in non-resistant plants. There was extensive and severe cell disruption and often obliteration of cell structure of the vascular parenchyma, xylem and phloem elements. In sharp contrast, among the resistant plants, feeding-related cell damage appeared to be substantially reduced compared to the non-resistant PUMA. Low frequency of damaged cells indicated that majority of the cell components of the vascular tissues were intact and presumed functional. There was evidence of salivary material lining the secondary walls of the vascular tissue, which resulted in severe damage. Within xylem vessels, saliva material impregnated half-bordered pit pairs between the vessels and adjacent xylem parenchyma. This is believed to prevent solute exchange through this interface, thereby inducing leaf stress and vi leaf roll. A notable finding is that RWASA2 effectively induced more cell damage to vascular tissues in the resistant lines than did RWASA1. In general the experimental evidence (see Chapter 5) suggests that the resistant lines are possibly more tolerant (or able to cope with) to RWA feeding. Evidence for this is the reduction of wound callose and at the TEM level, a comparatively less obvious cell damage in the resistant lines, which suggests that they possess antibiosis and tolerance capacity. The apparent reduction of feeding-related cell damage from the TEM study confirmed the disruptive action of the feeding aphids in experiments using the phloem-mobile probe, 5,6-CF. Results showed that feeding by RWASA1 and RWASA2 reducedthe transport functionality of the phloem in all cases, but that RWASA2 feeding caused a more obvious reduction in the rate and distance that 5,6-carboxyfluorescein was transported, than did RWASA1. Investigation of the effect of changing [CO2] on the barley cultivars showed that in the absence of aphids and under elevated CO2 conditions, the plants grew more vigorously. In this series of experiments, the infested plants suffered significant reduction in biomass under ambient (as was expected) and under the two elevated CO2 regimes. Biomass loss was greater at elevated CO2 than under ambient [CO2]. The infested nonresistant PUMA plants showed a more significant biomass loss than did the resistant cultivars. Clearly, the benefits derived from elevated CO2 enrichment was thus redirected to the now-advantaged aphids. Uninfested vii plants showed an increase in leaf nitrogen under the experimental conditions. However, feeding aphids depleted leaf nitrogen content and this was more apparent on plants exposed to RWASA2 than was the case with RWASA1. The end result of this was that C:N ratio of infested plants were higher than uninfested plants. Clearly, the faster breeding rates of the aphids at elevated CO2 caused depletion of N and a resultant deficiency exacerbated chlorosis as well as leaf rolling due to the higher aphid population density under elevated CO2 than at ambient. By 28 days after infestation (DAI), majority of the plants exposed to enriched CO2 treatments had died. A major finding here was thus that although this study demonstrated that elevated CO2 resulted in an increase in biomass, this was detrimentally offset in plants infested by the aphids, with a decline in biomass and loss of functionality leading to plant death at 28DAI. The overriding conclusion from this study is a clear signal that the twin effects of CO2 enrichment (a feature of current climate change) and aphid infestations may precipitate potential grain shortages. A disastrous food security threat looms.
- Full Text:
- Authors: Jimoh, Mahboob Adekilekun
- Date: 2011
- Subjects: Aphids Russian wheat aphid -- Research -- South Africa Barley -- Diseases and pests -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4201 , http://hdl.handle.net/10962/d1003770
- Description: Cereal crop productivity is hampered when these plants are infested by phloem feeding aphids. A great deal of research has been carried out with the direct aim of a clearer understanding of the mechanism involved in the interaction between aphids and their host plants. Research has directly or indirectly been geared towards enhanced plant productivity and achieving sustainable agriculture. Barley (Hordeum vulgare L.) is an important small grain crop in South Africa, whose crop performance is negatively affected by fluctuations in weather patterns as well as by agricultural pests. One of the insect pests infesting barley is the Russian wheat aphid, Diuraphis noxia Kurdjumov (RWA), of which the two South African biotypes, codenamed RWASA1 and RWASA2, were studied in this thesis. During dry spells, RWA infestation becomes a more serious threat to barley productivity. Resistant plants have been used to combat RWA infestation of small grains. In South Africa, 27 RWA-resistant wheat cultivars are currently used in commercial cultivation, but no resistant barley lines have, unfortunately, been developed, in spite of this grain’s significant economic importance. This informed the study in this thesis, and this interest particularly focussed on three RWA-resistant lines developed by the USDA, testing their performance against South African RWA biotypes, for possible adaptation to South Africa. The aim was thus to examine the plant-aphid interactions, aphid breeding rates, plant damage and sustainability, evidence of resistance or tolerance and finally potential performance under elevated CO2 (a very real climate change threat). Two major avenues of research were undertaken. The first aspect involved examination of structural and functional damage caused by RWASA1 and RWASA2 on the three resistant and a non-resistant line. Aphid population growth and damage symptoms (chlorosis and leaf roll) of infestation by these aphid biotypes were evaluated. This was followed by a structural and functional approach in which the effects of feeding on the transport systems (phloem and xylem) of barley were investigated. Fluorescence microscopy techniques (using aniline blue fluorochrome, a specific stain for callose and 5,6-CFDA, a phloem-mobile probe) were applied to investigate the feeding-related damage caused by the aphids, through an examination of wound callose formation and related to this, the resultant reduction in phloem transport capacity. Transmission electron microscopy (TEM) techniques provided evidence of the extent of the feeding-related cell damage. The second aspect involved a study of the effect of changing CO2 concentrations ([CO2]) on the resistant and susceptible barley cultivars to feeding by the two RWA biotypes. Leaves of plants grown at ambient and two elevated levels of [CO2] were analysed to investigate the effect of changing [CO2] on biomass, leaf nitrogen content and C:N ratio of control (uninfested) and infested plants. The population growth studies showed that the populations of the two RWA biotypes as well as bird cherry-oat aphid (BCA, Rhopalosiphum padi L.) increased substantially on the four barley lines. BCA was included here, as it had been the subject of several previous studies. RWASA2 bred faster than RWASA1 on all lines. The breeding rates of the two RWA biotypes were both suppressed and at near-equivalent levels on the three resistant lines, compared to the non-resistant PUMA. This suggests that the resistant lines possessed an antibiosis resistance mechanism against the feeding aphids. Feeding by the aphids manifested in morphological damage symptoms of chlorosis and leaf roll. The two biotypes inflicted severe chlorosis and leaf roll on the non-resistant PUMA. In the resistant plants, leaf rolling was more severe because of RWASA2 feeding compared to RWASA1 feeding. In contrast, chlorosis symptoms were more severe during RWASA1 feeding than was the case with RWASA2 feeding. Investigation of the effect of aphid feeding on the plants showed that callose was deposited within 24h and that this increased with longer feeding exposure. Wound callose distribution is more extensive in the non-resistant PUMA than in the resistant plants. RWASA2 feeding on the resistant lines caused deposition of more callose than was evident with RWASA1 feeding. During long-term feeding, it was evident that variation in the intensity and amount of wound callose was visible in the longitudinal and transverse veins of the resistant plants. Of the three STARS plants, STARS-9301B had the least callose. Interestingly, wound callose occurred in both resistant and non-resistant plants, in sharp contrast to what has been reported on resistant wheat cultivars that were developed in South Africa. The relative reduction in the wound callose deposited in the resistant line, when compared to the non-resistant lines, suggests the presence of a mechanism in the resistant lines, which may prevent excessive callose formation. Alternatively, the mechanism may stimulate callose breakdown. RWASA2 feeding on the resistant lines deposited more wound callose than RWASA1 feeding. This evidence supports the hypothesis that RWASA2 is a resistance breaking and more aggressive feeder than RWASA1 is; and further underscores the urgent need for development of RWA-resistant barley cultivars. The ultrastructural investigation of the feeding damage showed that the two biotypes caused extensive vascular damage in non-resistant plants. There was extensive and severe cell disruption and often obliteration of cell structure of the vascular parenchyma, xylem and phloem elements. In sharp contrast, among the resistant plants, feeding-related cell damage appeared to be substantially reduced compared to the non-resistant PUMA. Low frequency of damaged cells indicated that majority of the cell components of the vascular tissues were intact and presumed functional. There was evidence of salivary material lining the secondary walls of the vascular tissue, which resulted in severe damage. Within xylem vessels, saliva material impregnated half-bordered pit pairs between the vessels and adjacent xylem parenchyma. This is believed to prevent solute exchange through this interface, thereby inducing leaf stress and vi leaf roll. A notable finding is that RWASA2 effectively induced more cell damage to vascular tissues in the resistant lines than did RWASA1. In general the experimental evidence (see Chapter 5) suggests that the resistant lines are possibly more tolerant (or able to cope with) to RWA feeding. Evidence for this is the reduction of wound callose and at the TEM level, a comparatively less obvious cell damage in the resistant lines, which suggests that they possess antibiosis and tolerance capacity. The apparent reduction of feeding-related cell damage from the TEM study confirmed the disruptive action of the feeding aphids in experiments using the phloem-mobile probe, 5,6-CF. Results showed that feeding by RWASA1 and RWASA2 reducedthe transport functionality of the phloem in all cases, but that RWASA2 feeding caused a more obvious reduction in the rate and distance that 5,6-carboxyfluorescein was transported, than did RWASA1. Investigation of the effect of changing [CO2] on the barley cultivars showed that in the absence of aphids and under elevated CO2 conditions, the plants grew more vigorously. In this series of experiments, the infested plants suffered significant reduction in biomass under ambient (as was expected) and under the two elevated CO2 regimes. Biomass loss was greater at elevated CO2 than under ambient [CO2]. The infested nonresistant PUMA plants showed a more significant biomass loss than did the resistant cultivars. Clearly, the benefits derived from elevated CO2 enrichment was thus redirected to the now-advantaged aphids. Uninfested vii plants showed an increase in leaf nitrogen under the experimental conditions. However, feeding aphids depleted leaf nitrogen content and this was more apparent on plants exposed to RWASA2 than was the case with RWASA1. The end result of this was that C:N ratio of infested plants were higher than uninfested plants. Clearly, the faster breeding rates of the aphids at elevated CO2 caused depletion of N and a resultant deficiency exacerbated chlorosis as well as leaf rolling due to the higher aphid population density under elevated CO2 than at ambient. By 28 days after infestation (DAI), majority of the plants exposed to enriched CO2 treatments had died. A major finding here was thus that although this study demonstrated that elevated CO2 resulted in an increase in biomass, this was detrimentally offset in plants infested by the aphids, with a decline in biomass and loss of functionality leading to plant death at 28DAI. The overriding conclusion from this study is a clear signal that the twin effects of CO2 enrichment (a feature of current climate change) and aphid infestations may precipitate potential grain shortages. A disastrous food security threat looms.
- Full Text:
Consumer perceptions of private label brands: an Eastern Cape university-aged analysis
- Authors: Mpofu, Bukhosi Dumoluhle
- Date: 2011
- Subjects: House brands -- South Africa -- Eastern Cape Young consumers -- South Africa -- Eastern Cape Consumer behavior -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1167 , http://hdl.handle.net/10962/d1002783
- Description: This research investigates the consumer perceptions of private label brands amongst the university aged consumers from selected Eastern Cape universities. The research also aimed to ascertain whether or not generation Y consumers are aware of the existence of private labels, whether price, quality, advertising, packaging, reference groups and demographic variables influenced generation Y purchasing behavior of private label brands. To achieve these objectives, the research made use of the simple random technique to gather the primary data via the use of an online structured questionnaire. The sample population selected where the students in the Eastern Cape Province Universities (Rhodes and Nelson Mandela Metropolitan Universities) who reside off-campus. The assumption was that students who reside off-campus are more aware of private labels as they carry out shopping more than those that reside on campus and generally would have more disposable income and the reason that two different universities have been chosen is to provide a broad base of student opinions, covering varying cultural and income backgrounds, thus allowing for unbiased, valuable research. After pre-tests were conducted the questionnaire was made available online to easy the distribution of the questionnaire and allow for a greater response rate. Descriptive and inferential statistics where used to analyze the results of the questionnaire. The results showed that consumers are generally aware of private label brands and have at least seen them being advertised. Furthermore, the results showed that consumers purchase groceries based on price, quality and convenience of location of the grocery stores .The results indicate that Generation Y consumers are indeed a significant part of the consumer population and that they represent a confident, self reliant, optimistic and positive generation and are verbally and visually more sophisticated, creating a whole new language through digital media and that Generation Y consumers are generally aware of the existence of private labels. The results also indicate that Generation Y consumers strongly agreed that they purchase groceries based on price and quality, meaning price and quality are very influential when purchasing groceries and that the packaging of, generally, all private label brands was not attractive hence a conclusion was made that packaging of private labeled products does not influence Generation Y’s purchasing behaviour of private labels.
- Full Text:
- Authors: Mpofu, Bukhosi Dumoluhle
- Date: 2011
- Subjects: House brands -- South Africa -- Eastern Cape Young consumers -- South Africa -- Eastern Cape Consumer behavior -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1167 , http://hdl.handle.net/10962/d1002783
- Description: This research investigates the consumer perceptions of private label brands amongst the university aged consumers from selected Eastern Cape universities. The research also aimed to ascertain whether or not generation Y consumers are aware of the existence of private labels, whether price, quality, advertising, packaging, reference groups and demographic variables influenced generation Y purchasing behavior of private label brands. To achieve these objectives, the research made use of the simple random technique to gather the primary data via the use of an online structured questionnaire. The sample population selected where the students in the Eastern Cape Province Universities (Rhodes and Nelson Mandela Metropolitan Universities) who reside off-campus. The assumption was that students who reside off-campus are more aware of private labels as they carry out shopping more than those that reside on campus and generally would have more disposable income and the reason that two different universities have been chosen is to provide a broad base of student opinions, covering varying cultural and income backgrounds, thus allowing for unbiased, valuable research. After pre-tests were conducted the questionnaire was made available online to easy the distribution of the questionnaire and allow for a greater response rate. Descriptive and inferential statistics where used to analyze the results of the questionnaire. The results showed that consumers are generally aware of private label brands and have at least seen them being advertised. Furthermore, the results showed that consumers purchase groceries based on price, quality and convenience of location of the grocery stores .The results indicate that Generation Y consumers are indeed a significant part of the consumer population and that they represent a confident, self reliant, optimistic and positive generation and are verbally and visually more sophisticated, creating a whole new language through digital media and that Generation Y consumers are generally aware of the existence of private labels. The results also indicate that Generation Y consumers strongly agreed that they purchase groceries based on price and quality, meaning price and quality are very influential when purchasing groceries and that the packaging of, generally, all private label brands was not attractive hence a conclusion was made that packaging of private labeled products does not influence Generation Y’s purchasing behaviour of private labels.
- Full Text:
Curating the reviled, beloved and quotidian: a retrospective of Vladimir Tretchikoff
- Authors: Lamprecht, Andrew Paul
- Date: 2011
- Subjects: Tretchikoff, Vladimir -- Criticism and interpretation Painters -- South Africa -- Criticism and interpretation Curatorship -- South Africa -- Art Kitsch
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2407 , http://hdl.handle.net/10962/d1002203
- Description: This thesis aims to contextualise my curation of 'Tretchikoff: The People's Painter' at the Iziko South African National Gallery by outlining the process by which I came to embark on this project and to examine the concepts of mass art and kitsch in relation to the painter. Mass art, in Noel Carroll's explication of the term, is art that utilises industrial processes of replication. Carroll argues that this leads to specific formal and structural tendencies in this art which have much in common with the pejorative concept of kitsch, or art that is lacking in taste or effuses excessive emotion. The latter term was and continues to be applied to Tretchikoff. Although some have attempted to 'reclaim' the word as a positive concept the negative associations that link this term to Tretchikoff are strong. Interrogating these concepts led me to decide to curate TretchikofPs retrospective by focusing on his painting and not including the prints for which he was so well known. Awareness of the complex associations and 'received knowledge' that his prints engender has influenced several curatorial decisions that I have taken. I consider the intellectual underpinnings of my curatorial strategy and argue for an 'open' exhibition which gives the viewer the opportunity to assess his work and legacy in an objective manner, free from as much curatorial mediation and didacticsm as possible. There are no answers to be offered in my curation of Tretchikxiff the People's Painter, rather I have aimed to set up dialogues, discussions, confrontations and challenges; I have offered simple relationships rather than complex juxtapositions I have aimed to position the artwork as the centre of the engagement relative to the viewer.
- Full Text:
- Authors: Lamprecht, Andrew Paul
- Date: 2011
- Subjects: Tretchikoff, Vladimir -- Criticism and interpretation Painters -- South Africa -- Criticism and interpretation Curatorship -- South Africa -- Art Kitsch
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2407 , http://hdl.handle.net/10962/d1002203
- Description: This thesis aims to contextualise my curation of 'Tretchikoff: The People's Painter' at the Iziko South African National Gallery by outlining the process by which I came to embark on this project and to examine the concepts of mass art and kitsch in relation to the painter. Mass art, in Noel Carroll's explication of the term, is art that utilises industrial processes of replication. Carroll argues that this leads to specific formal and structural tendencies in this art which have much in common with the pejorative concept of kitsch, or art that is lacking in taste or effuses excessive emotion. The latter term was and continues to be applied to Tretchikoff. Although some have attempted to 'reclaim' the word as a positive concept the negative associations that link this term to Tretchikoff are strong. Interrogating these concepts led me to decide to curate TretchikofPs retrospective by focusing on his painting and not including the prints for which he was so well known. Awareness of the complex associations and 'received knowledge' that his prints engender has influenced several curatorial decisions that I have taken. I consider the intellectual underpinnings of my curatorial strategy and argue for an 'open' exhibition which gives the viewer the opportunity to assess his work and legacy in an objective manner, free from as much curatorial mediation and didacticsm as possible. There are no answers to be offered in my curation of Tretchikxiff the People's Painter, rather I have aimed to set up dialogues, discussions, confrontations and challenges; I have offered simple relationships rather than complex juxtapositions I have aimed to position the artwork as the centre of the engagement relative to the viewer.
- Full Text:
Development of techniques for the isolation of a granulovirus from potato tuber moth, phthorimaea operculella (Zeller)
- Authors: King, Shirley Anne
- Date: 2011
- Subjects: Potato tuberworm -- Larvae , Agricultural pests -- Biological control , Potato tuberworm , Baculoviruses
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5910 , http://hdl.handle.net/10962/d1015202
- Description: Phthorimaea operculella, commonly known as the Potato Tuber Moth, is an economically important agricultural pest worldwide. The baculovirus, Phthorimaea operculella granulovirus (PhoGV) has been considered as a means of control alternative to chemical control because of its host specificity and harmless impact on other organisms and ecosystems. An isolate of PhoGV obtained from a South African PTM population would be beneficial in the production of a biopesticide, which is not yet available. An efficient and cost-effective rearing method would be advantageous for potential commercial production. Commercial table and seed potato plantations and storage facilities located in Patensie, Bathurst, Howick and Ivanhoe were surveyed for PTM infestations. Patensie was the only site where milky discoloured larvae were found, a potential symptom of PhoGV infection. TEM analysis revealed no virus in these samples. Since no virus was found in the field-collected samples, PTM insects were collected to initiate rearing in the laboratory. PTM was raised by three different methods in the laboratory. A cost/benefit analysis, survival rate, fertility and sex ratio were recorded for each rearing method. Rearing method one was deemed unsuccessful for efficient commercial rearing, as survival percentage and fertility were low. Rearing methods two and three had high survival rates and high fertility, and were efficient and less labour intensive than rearing method one. Rearing method three was the most productive technique, but for commercial production rearing method two was considered the most manageable and efficient. The sex ratio was 1:1 for all three cultures. The cost analysis revealed that rearing methods two and three were less expensive than rearing method one because less labour was required to monitor insects. The success of rearing PTM for 19 months will enable these cultures to be up-scaled to a large production facility for mass rearing. Virus was not found in the field surveys or in laboratory cultures, therefore chemical, temperature, humidity and carbon dioxide stressors were used in an attempt to initiate a baculoviral infection. Symptoms were exhibited in larvae subjected to chemical, temperature and humidity treatments, but these were confirmed by TEM analysis not to be a result of PhoGV infection. The success of rearing PTM in the laboratory suggests that the method could be used in the commercial rearing of the insects in a large mass-rearing facility. The data obtained from induction protocols have allowed for better understanding for future induction for PhoGV and other baculoviruses in other insect species. The failure to isolate a South African PhoGV strain for developing a biopesticide against PTM has motivated further studies in obtaining a baculovirus in order for South Africa to develop a commercial product against this pest.
- Full Text:
- Authors: King, Shirley Anne
- Date: 2011
- Subjects: Potato tuberworm -- Larvae , Agricultural pests -- Biological control , Potato tuberworm , Baculoviruses
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5910 , http://hdl.handle.net/10962/d1015202
- Description: Phthorimaea operculella, commonly known as the Potato Tuber Moth, is an economically important agricultural pest worldwide. The baculovirus, Phthorimaea operculella granulovirus (PhoGV) has been considered as a means of control alternative to chemical control because of its host specificity and harmless impact on other organisms and ecosystems. An isolate of PhoGV obtained from a South African PTM population would be beneficial in the production of a biopesticide, which is not yet available. An efficient and cost-effective rearing method would be advantageous for potential commercial production. Commercial table and seed potato plantations and storage facilities located in Patensie, Bathurst, Howick and Ivanhoe were surveyed for PTM infestations. Patensie was the only site where milky discoloured larvae were found, a potential symptom of PhoGV infection. TEM analysis revealed no virus in these samples. Since no virus was found in the field-collected samples, PTM insects were collected to initiate rearing in the laboratory. PTM was raised by three different methods in the laboratory. A cost/benefit analysis, survival rate, fertility and sex ratio were recorded for each rearing method. Rearing method one was deemed unsuccessful for efficient commercial rearing, as survival percentage and fertility were low. Rearing methods two and three had high survival rates and high fertility, and were efficient and less labour intensive than rearing method one. Rearing method three was the most productive technique, but for commercial production rearing method two was considered the most manageable and efficient. The sex ratio was 1:1 for all three cultures. The cost analysis revealed that rearing methods two and three were less expensive than rearing method one because less labour was required to monitor insects. The success of rearing PTM for 19 months will enable these cultures to be up-scaled to a large production facility for mass rearing. Virus was not found in the field surveys or in laboratory cultures, therefore chemical, temperature, humidity and carbon dioxide stressors were used in an attempt to initiate a baculoviral infection. Symptoms were exhibited in larvae subjected to chemical, temperature and humidity treatments, but these were confirmed by TEM analysis not to be a result of PhoGV infection. The success of rearing PTM in the laboratory suggests that the method could be used in the commercial rearing of the insects in a large mass-rearing facility. The data obtained from induction protocols have allowed for better understanding for future induction for PhoGV and other baculoviruses in other insect species. The failure to isolate a South African PhoGV strain for developing a biopesticide against PTM has motivated further studies in obtaining a baculovirus in order for South Africa to develop a commercial product against this pest.
- Full Text:
Development, manufacture and assessment of Clobetasol 17-propionate cream formulations
- Fauzee, Ayeshah Fateemah Beebee
- Authors: Fauzee, Ayeshah Fateemah Beebee
- Date: 2011
- Subjects: Adrenocortical hormones , Adrenocortical hormones -- Physiological effect , Adrenocortical hormones -- Testing , Drugs -- Testing , Drugs -- Development , Dermatopharmacology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3856 , http://hdl.handle.net/10962/d1013324
- Description: Eczema or dermatitis is the most common dermatological condition accounting for one-third of all diagnoses in the total population surveyed in South Africa. The prevalence of seborrhoeic dermatitis, extreme photodermatitis and severe psoriasis has increased markedly over the last decade and this increase may be ascribed to the HIV epidemic, first diagnosed in South Africa in 1982. Potent innovator corticosteroids, such as clobetasol 17-propionate (CP) that are used to treat skin disorders, are expensive and there is therefore a need for the production of generic topical corticosteroid products. Formulation and manufacturing processes can be challenging aspects for formulation scientists to produce a robust product that will elicit an appropriate and desirable pharmacokinetic-pharmacodynamic profile. Laboratory scale CP creams were manufactured using different concentrations of Gelot® 64 and propylene glycol in order to establish a composition that would produce a formulation, with similar physical and chemical characteristics and in vitro release profile as an innovator product, Dermovate®. These formulations were assessed in terms of their viscosity, spreadability, pH, content uniformity and in vitro release characteristics using a Franz diffusion cell apparatus. A formulation containing 3% w/w Gelot® 64 and 46% v/v propylene glycol (CPLS-02) was found to exhibit similar viscosity and spreadability characteristics and released CP in a manner similar to Dermovate®. The mechanism of drug release was evaluated using mathematical models such as zero order, first order and Higuchi models. In addition, the in vitro release profiles were characterised by use of difference (f1) and similarity (f2 and Sd) factors. A scale-up formulation with the same % w/w composition as the laboratory scale was also investigated following manufacture using a Wintech® cream/ointment mixer. A Central Composite Design approach was used to investigate the effect of process variables on the performance of the scale-up cream formulations. The homogenisation speed, anchor speed, homogenisation time and cooling time were the process variables investigated. Thirty scale-up batches were manufactured and analysed in terms of their viscosity, spreadability, pH, % drug content and cumulative % drug released per unit area over 72 hours. Model fitting using Design-Expert® software was undertaken and revealed that a correlation between the process variables and the cream responses was most suitably described by quadratic polynomial relationships. The homogenisation speed had the most significant effect on the quality of the scale-up formulations, whereas the anchor speed had a secondary effect on the measured responses, for the formulations investigated. The qualitative interpretation and statistical analysis of the in vitro release data from the scale-up formulations using ANOVA and the f1, f2 and Sd factors revealed that one scale-up batch (CPSU-04), for which the process variables were a homogenisation speed of 1900 rpm, an anchor speed of 35 rpm, a homogenisation time of 100 minutes and a cooling time of 100 minutes, released CP at a similar rate and extent to Dermovate®. A diffusion-controlled mechanism appeared to be predominant in these formulations. A human skin blanching study, using both visual and chromameter assessments, was performed to establish whether batch CPSU-04 was bioequivalent to Dermovate®. The bioequivalence of the selected scale-up formulation to Dermovate® was confirmed, following the calculation of a 90% CI.
- Full Text:
- Authors: Fauzee, Ayeshah Fateemah Beebee
- Date: 2011
- Subjects: Adrenocortical hormones , Adrenocortical hormones -- Physiological effect , Adrenocortical hormones -- Testing , Drugs -- Testing , Drugs -- Development , Dermatopharmacology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3856 , http://hdl.handle.net/10962/d1013324
- Description: Eczema or dermatitis is the most common dermatological condition accounting for one-third of all diagnoses in the total population surveyed in South Africa. The prevalence of seborrhoeic dermatitis, extreme photodermatitis and severe psoriasis has increased markedly over the last decade and this increase may be ascribed to the HIV epidemic, first diagnosed in South Africa in 1982. Potent innovator corticosteroids, such as clobetasol 17-propionate (CP) that are used to treat skin disorders, are expensive and there is therefore a need for the production of generic topical corticosteroid products. Formulation and manufacturing processes can be challenging aspects for formulation scientists to produce a robust product that will elicit an appropriate and desirable pharmacokinetic-pharmacodynamic profile. Laboratory scale CP creams were manufactured using different concentrations of Gelot® 64 and propylene glycol in order to establish a composition that would produce a formulation, with similar physical and chemical characteristics and in vitro release profile as an innovator product, Dermovate®. These formulations were assessed in terms of their viscosity, spreadability, pH, content uniformity and in vitro release characteristics using a Franz diffusion cell apparatus. A formulation containing 3% w/w Gelot® 64 and 46% v/v propylene glycol (CPLS-02) was found to exhibit similar viscosity and spreadability characteristics and released CP in a manner similar to Dermovate®. The mechanism of drug release was evaluated using mathematical models such as zero order, first order and Higuchi models. In addition, the in vitro release profiles were characterised by use of difference (f1) and similarity (f2 and Sd) factors. A scale-up formulation with the same % w/w composition as the laboratory scale was also investigated following manufacture using a Wintech® cream/ointment mixer. A Central Composite Design approach was used to investigate the effect of process variables on the performance of the scale-up cream formulations. The homogenisation speed, anchor speed, homogenisation time and cooling time were the process variables investigated. Thirty scale-up batches were manufactured and analysed in terms of their viscosity, spreadability, pH, % drug content and cumulative % drug released per unit area over 72 hours. Model fitting using Design-Expert® software was undertaken and revealed that a correlation between the process variables and the cream responses was most suitably described by quadratic polynomial relationships. The homogenisation speed had the most significant effect on the quality of the scale-up formulations, whereas the anchor speed had a secondary effect on the measured responses, for the formulations investigated. The qualitative interpretation and statistical analysis of the in vitro release data from the scale-up formulations using ANOVA and the f1, f2 and Sd factors revealed that one scale-up batch (CPSU-04), for which the process variables were a homogenisation speed of 1900 rpm, an anchor speed of 35 rpm, a homogenisation time of 100 minutes and a cooling time of 100 minutes, released CP at a similar rate and extent to Dermovate®. A diffusion-controlled mechanism appeared to be predominant in these formulations. A human skin blanching study, using both visual and chromameter assessments, was performed to establish whether batch CPSU-04 was bioequivalent to Dermovate®. The bioequivalence of the selected scale-up formulation to Dermovate® was confirmed, following the calculation of a 90% CI.
- Full Text:
Dryland conservation areas, indigenous people, livelihoods and natural resource values in South Africa: the case of Kgalagadi Transfrontier Park
- Authors: Thondhlana, Gladman
- Date: 2011
- Subjects: Human ecology -- Kgalagadi Transfrontier Park (Botswana and South Africa) Arid regions biodiversity conservation -- Kgalagadi Transfrontier Park (Botswana and South Africa) Arid regions agriculture -- Kgalagadi Transfrontier Park (Botswana and South Africa) Indigenous peoples -- Ecology -- Kgalagadi Transfrontier Park (Botswana and South Africa) Natural resources conservation areas -- Kgalagadi Transfrontier Park (Botswana and South Africa) Natural resources -- Government policy -- Kgalagadi Transfrontier Park (Botswana and South Africa) Natural resources -- Kgalagadi Transfrontier Park (Botswana and South Africa) -- Management
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4777 , http://hdl.handle.net/10962/d1011732
- Description: Contemporary conservation and development understanding in both policy and academic circles espouses that natural resources have a significant contribution to the livelihoods of local people and that knowledge of this can better foster conservation policies that are consistent with livelihood and ecological needs. This thesis is based on research conducted in the southern Kalahari region, South Africa among the San and Mier communities bordering Kgalagadi Transfrontier Park. It looks at the importance of natural resources to the San and Mier community groups and ascertains the extent of resource use and its value within broader livelihood portfolios. It also focuses on the cultural values of natural resources and interactions among institutions and actors and how these shape natural resource governance and livelihood outcomes. Overall, natural resources represent an important livelihood source contributing up to 32 % and 9 % of the total income of the San and Mier respectively or up to 46 % and 23 % if livestock incomes are included. However, the dependence on, diversification patterns and distribution of natural resource income vary substantially between and within the two communities. With regards to the cultural values attached to natural resources by the San and Mier, the findings show that these arise from an incredibly diverse and sometimes conflicting array of values that punctuate the two communities’ way of life and they are inextricably linked to resource use. Lastly, governance of natural resources in the co-managed Park and communitymanaged resettlement farms is characterised by complex institutional arrangements, compounded by the existence of multiple actors that have multiple and sometimes conflicting objectives – as shaped by different meanings and interpretations of natural resources. Heightened inter- and intra-community conflicts are common, notably resource use conflicts between the San and Mier and between the San ‘modernist’ and ‘traditionalist’ groups. This demonstrates that the communities’ livelihood dynamics in general and the dependence on natural resources in particular, are closely linked with ecological, economic and social factors including history, culture and present livelihood needs. By exploring the social-environment interactions, the study highlights the complexities and diversity of resource use for livelihoods that should be taken into consideration for both conservation and development policy interventions and research. The main argument of the study is that the contribution of natural resources to local livelihood portfolios in co- and community-managed areas, can be better understood through a consideration of cultural dynamics and institutional arrangements since these condition natural resource access, value and use.
- Full Text:
- Authors: Thondhlana, Gladman
- Date: 2011
- Subjects: Human ecology -- Kgalagadi Transfrontier Park (Botswana and South Africa) Arid regions biodiversity conservation -- Kgalagadi Transfrontier Park (Botswana and South Africa) Arid regions agriculture -- Kgalagadi Transfrontier Park (Botswana and South Africa) Indigenous peoples -- Ecology -- Kgalagadi Transfrontier Park (Botswana and South Africa) Natural resources conservation areas -- Kgalagadi Transfrontier Park (Botswana and South Africa) Natural resources -- Government policy -- Kgalagadi Transfrontier Park (Botswana and South Africa) Natural resources -- Kgalagadi Transfrontier Park (Botswana and South Africa) -- Management
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4777 , http://hdl.handle.net/10962/d1011732
- Description: Contemporary conservation and development understanding in both policy and academic circles espouses that natural resources have a significant contribution to the livelihoods of local people and that knowledge of this can better foster conservation policies that are consistent with livelihood and ecological needs. This thesis is based on research conducted in the southern Kalahari region, South Africa among the San and Mier communities bordering Kgalagadi Transfrontier Park. It looks at the importance of natural resources to the San and Mier community groups and ascertains the extent of resource use and its value within broader livelihood portfolios. It also focuses on the cultural values of natural resources and interactions among institutions and actors and how these shape natural resource governance and livelihood outcomes. Overall, natural resources represent an important livelihood source contributing up to 32 % and 9 % of the total income of the San and Mier respectively or up to 46 % and 23 % if livestock incomes are included. However, the dependence on, diversification patterns and distribution of natural resource income vary substantially between and within the two communities. With regards to the cultural values attached to natural resources by the San and Mier, the findings show that these arise from an incredibly diverse and sometimes conflicting array of values that punctuate the two communities’ way of life and they are inextricably linked to resource use. Lastly, governance of natural resources in the co-managed Park and communitymanaged resettlement farms is characterised by complex institutional arrangements, compounded by the existence of multiple actors that have multiple and sometimes conflicting objectives – as shaped by different meanings and interpretations of natural resources. Heightened inter- and intra-community conflicts are common, notably resource use conflicts between the San and Mier and between the San ‘modernist’ and ‘traditionalist’ groups. This demonstrates that the communities’ livelihood dynamics in general and the dependence on natural resources in particular, are closely linked with ecological, economic and social factors including history, culture and present livelihood needs. By exploring the social-environment interactions, the study highlights the complexities and diversity of resource use for livelihoods that should be taken into consideration for both conservation and development policy interventions and research. The main argument of the study is that the contribution of natural resources to local livelihood portfolios in co- and community-managed areas, can be better understood through a consideration of cultural dynamics and institutional arrangements since these condition natural resource access, value and use.
- Full Text:
Economic impact studies and methodological bias : the case of the National Arts Festival in South Africa
- Authors: Bragge, Brent Reuben
- Date: 2011
- Subjects: Standard Bank National Arts Festival Standard Bank National Arts Festival -- Economic aspects Performing arts festivals- Economic aspects -- South Africa Arts -- Economic aspects -- South Africa Economic impact analysis Edinburgh International Festival -- Economic aspects Klein Karoo Nasionale Kunstefees (Oudtshoorn, South Africa) -- Economic aspects Volksbladfees (Bloemfontein, South Africa) -- Economic aspects
- Language: English
- Type: Thesis , Masters , MEcon
- Identifier: vital:968 , http://hdl.handle.net/10962/d1002702
- Description: Over the course of the last three decades, it has become popular practice to evaluate tourism events like cultural festivals in financial terms, through the use of economic impact studies. This can be attributed at least in part to the notable growth in the number of festivals being held globally and, as such, a higher level of competition between festivals for the limited funding which is available. Economic impact studies, and the resultant findings, have thus become powerful tools for the lobbying of sponsorship, and it has become increasingly important that the impact calculations be as accurate as possible, so as to effectively allocate both government and private resources to projects which will be of the greatest benefit to the host region. The allocation of funding is especially vital in an area like the Eastern Cape Province of South Africa, which is faced with many financial difficulties. The allocation of public funds to an event like the National Arts Festival, which is hosted in a relatively wealthy part of the province, might be weighed against initiatives which directly benefit the poorer parts of the region. Although it is acknowledged that the benefits which are felt by the host community of a cultural event go beyond that of the financial, it is often on this basis that festivals are most easily compared. The primary goal of the thesis was to analyse the various forms of methodological bias which can exist in the economic impact analyses (EIA) associated with cultural events. Theoretical considerations were discussed, specifically regarding economic impact as a method of measuring value. Various forms of bias (including data collection, the calculation of visitor numbers, multipliers, defining the area of interest, inclusion of visitor spending, and accounting for benefits only, not costs) are put into a real-life context, through the investigation of economic impact studies conducted on three selected South African festivals (the Volksblad, the Klein Karoo Nasionale Kunstfees, and the National Arts Festival), and one international festival (the Edinburgh Festival). An in-depth comparison of two separate studies conducted at the National Arts Festival (NAF) in 2004 (by Antrobus and Snowball) and 2005 (by Saayman et al.) was made, focussing on the manner in which the economic impact was calculated. Having considered the common forms of bias, and assessing several possible reasons for the difference of approximately twenty million Rand in the advertised economic impacts, it was concluded that, most likely, the miscalculation of visitor numbers was the cause. This was confirmed when the Antrobus and Saayman methods were applied to the 2006 NAF data, and noting that the economic impact figures arrived at were strikingly similar. As such, it is advisable that extreme caution be taken when calculating visitor numbers, as they can significantly influence the outcome of an economic impact study. It is recommended that each study should also have transparent checks in place, regarding the key calculation figures, to ensure that less scrupulous researchers are not as easily able to succumb to the pressure event sponsors might impose to produce inflated impact values.
- Full Text:
- Authors: Bragge, Brent Reuben
- Date: 2011
- Subjects: Standard Bank National Arts Festival Standard Bank National Arts Festival -- Economic aspects Performing arts festivals- Economic aspects -- South Africa Arts -- Economic aspects -- South Africa Economic impact analysis Edinburgh International Festival -- Economic aspects Klein Karoo Nasionale Kunstefees (Oudtshoorn, South Africa) -- Economic aspects Volksbladfees (Bloemfontein, South Africa) -- Economic aspects
- Language: English
- Type: Thesis , Masters , MEcon
- Identifier: vital:968 , http://hdl.handle.net/10962/d1002702
- Description: Over the course of the last three decades, it has become popular practice to evaluate tourism events like cultural festivals in financial terms, through the use of economic impact studies. This can be attributed at least in part to the notable growth in the number of festivals being held globally and, as such, a higher level of competition between festivals for the limited funding which is available. Economic impact studies, and the resultant findings, have thus become powerful tools for the lobbying of sponsorship, and it has become increasingly important that the impact calculations be as accurate as possible, so as to effectively allocate both government and private resources to projects which will be of the greatest benefit to the host region. The allocation of funding is especially vital in an area like the Eastern Cape Province of South Africa, which is faced with many financial difficulties. The allocation of public funds to an event like the National Arts Festival, which is hosted in a relatively wealthy part of the province, might be weighed against initiatives which directly benefit the poorer parts of the region. Although it is acknowledged that the benefits which are felt by the host community of a cultural event go beyond that of the financial, it is often on this basis that festivals are most easily compared. The primary goal of the thesis was to analyse the various forms of methodological bias which can exist in the economic impact analyses (EIA) associated with cultural events. Theoretical considerations were discussed, specifically regarding economic impact as a method of measuring value. Various forms of bias (including data collection, the calculation of visitor numbers, multipliers, defining the area of interest, inclusion of visitor spending, and accounting for benefits only, not costs) are put into a real-life context, through the investigation of economic impact studies conducted on three selected South African festivals (the Volksblad, the Klein Karoo Nasionale Kunstfees, and the National Arts Festival), and one international festival (the Edinburgh Festival). An in-depth comparison of two separate studies conducted at the National Arts Festival (NAF) in 2004 (by Antrobus and Snowball) and 2005 (by Saayman et al.) was made, focussing on the manner in which the economic impact was calculated. Having considered the common forms of bias, and assessing several possible reasons for the difference of approximately twenty million Rand in the advertised economic impacts, it was concluded that, most likely, the miscalculation of visitor numbers was the cause. This was confirmed when the Antrobus and Saayman methods were applied to the 2006 NAF data, and noting that the economic impact figures arrived at were strikingly similar. As such, it is advisable that extreme caution be taken when calculating visitor numbers, as they can significantly influence the outcome of an economic impact study. It is recommended that each study should also have transparent checks in place, regarding the key calculation figures, to ensure that less scrupulous researchers are not as easily able to succumb to the pressure event sponsors might impose to produce inflated impact values.
- Full Text:
Effect of alkaline pre-treatments on the synergistic enzymatic hydrolysis of sugarcane (Saccharum officinarum) bagasse by Clostridium cellulovorans XynA, ManA and ArfA
- Authors: Beukes, Natasha
- Date: 2011
- Subjects: Sugarcane -- Biotechnology Lignocellulose -- Biotechnology Renewable energy sources Hydrolysis Enzymes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3952 , http://hdl.handle.net/10962/d1004011
- Description: The continual increase in industrialization and global population has increased the dependency and demand on traditional fossil fuels for energy; however, there are limited amounts of fossil fuels available. The slow depletion of fossil fuels has sparked a fresh interest in renewable sources such as lignocellulose to produce a variety of biofuels, such as biogases (e.g. methane), bioethanol, biodiesel and a variety of other solvents and economically valuable by-products. Agricultural crop wastes produced in surplus are typically lignocellulosic in composition and thus partially recalcitrant to enzymatic degradation. The recalcitrant nature of plant biomass and the inability to obtain complete enzymatic hydrolysis has led to the establishment of various pre-treatment strategies. Alkaline pre-treatments increase the accessibility of the exposed surface to enzymatic hydrolysis through the removal of acetyl and uronic acid substituents on hemicellulose. Unlike the use of steam and acid pre-treatments, alkaline pre-treatments solubilize lignin and a small percentage of the hemicellulose, increasing enzyme accessibility and thus the hydrolysis of lignocellulose. The majority of Clostridium cellulovorans associated enzyme synergy studies have been devoted to an understanding of the cellulolytic and hemi-cellulolytic degradation of plant cell walls. However, little is known about the effect of various physical and chemical pre-treatments on the synergistic enzymatic degradation of plant biomass and possible depolymerization of plant cell walls. This study investigates the use of slake lime, sodium hydroxide and ammonium hydroxide to pre-treat sugarcane bagasse under mild conditions and elucidates potentially important synergistic associations between the C. cellulovorans enzymes for the enhanced degradation of lignocellulose. The primary aims of the study were addressed using of a variety of techniques. This included suitable vector constructs for the expression and purification of recombinant C. cellulovorans enzymes, identification of the effects of various pre-treatments on enzyme synergy, and identification of the resultant reducing sugars and phenolic compounds (released during the pre-treatment of the bagasse). This study also made use of physical and chemical pre-treatment methods, protein purification using affinity, high performance liquid and thin layer chromatography, mass spectrometry, sodium dodecyl sulphate and fluorophore-assisted polyacrylamide gel electrophoresis (FACE) , enzymatic degradation and synergy studies with various substrates indirectly using the 3, 4-dinitrosalicylic acid (DNS) reducing sugar assay. From this investigation, the following conclusions were made: alkaline pre-treatment successfully solublised, redistributed and removed lignin from the bagasse, increasing the digestibility of the substrates. In summary, the most effective pre-treatment employed 0.114 M ammonium hydroxide / gram bagasse at 70°C for 36 hours, followed by hydrolysis with an enzyme cocktail containing 25% ManA and 75% XynA. This increased the production of sugars approximately 13-fold. Analysis of the sugars produced by the synergistic hydrolysis of sugarcane bagasse (SCB) indicated the presence of xylose, indicating that the enzymes are potentially bifunctional under certain conditions. This study indicated that the use of mild pre-treatment conditions sufficiently removed a large portion of lignin without affecting the hemicellulose moiety of the SCB. This facilitated the potential use of the hemicellulose component for the production of valuable products (e.g. xylitol) in addition to the production of bioethanol. Thus, the potential use of additional components of holocellulose may generate an additional biotechnological benefit and allow a certain degree of flexibility in the biofuel industry, depending on consumer and industrial needs.
- Full Text:
- Authors: Beukes, Natasha
- Date: 2011
- Subjects: Sugarcane -- Biotechnology Lignocellulose -- Biotechnology Renewable energy sources Hydrolysis Enzymes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3952 , http://hdl.handle.net/10962/d1004011
- Description: The continual increase in industrialization and global population has increased the dependency and demand on traditional fossil fuels for energy; however, there are limited amounts of fossil fuels available. The slow depletion of fossil fuels has sparked a fresh interest in renewable sources such as lignocellulose to produce a variety of biofuels, such as biogases (e.g. methane), bioethanol, biodiesel and a variety of other solvents and economically valuable by-products. Agricultural crop wastes produced in surplus are typically lignocellulosic in composition and thus partially recalcitrant to enzymatic degradation. The recalcitrant nature of plant biomass and the inability to obtain complete enzymatic hydrolysis has led to the establishment of various pre-treatment strategies. Alkaline pre-treatments increase the accessibility of the exposed surface to enzymatic hydrolysis through the removal of acetyl and uronic acid substituents on hemicellulose. Unlike the use of steam and acid pre-treatments, alkaline pre-treatments solubilize lignin and a small percentage of the hemicellulose, increasing enzyme accessibility and thus the hydrolysis of lignocellulose. The majority of Clostridium cellulovorans associated enzyme synergy studies have been devoted to an understanding of the cellulolytic and hemi-cellulolytic degradation of plant cell walls. However, little is known about the effect of various physical and chemical pre-treatments on the synergistic enzymatic degradation of plant biomass and possible depolymerization of plant cell walls. This study investigates the use of slake lime, sodium hydroxide and ammonium hydroxide to pre-treat sugarcane bagasse under mild conditions and elucidates potentially important synergistic associations between the C. cellulovorans enzymes for the enhanced degradation of lignocellulose. The primary aims of the study were addressed using of a variety of techniques. This included suitable vector constructs for the expression and purification of recombinant C. cellulovorans enzymes, identification of the effects of various pre-treatments on enzyme synergy, and identification of the resultant reducing sugars and phenolic compounds (released during the pre-treatment of the bagasse). This study also made use of physical and chemical pre-treatment methods, protein purification using affinity, high performance liquid and thin layer chromatography, mass spectrometry, sodium dodecyl sulphate and fluorophore-assisted polyacrylamide gel electrophoresis (FACE) , enzymatic degradation and synergy studies with various substrates indirectly using the 3, 4-dinitrosalicylic acid (DNS) reducing sugar assay. From this investigation, the following conclusions were made: alkaline pre-treatment successfully solublised, redistributed and removed lignin from the bagasse, increasing the digestibility of the substrates. In summary, the most effective pre-treatment employed 0.114 M ammonium hydroxide / gram bagasse at 70°C for 36 hours, followed by hydrolysis with an enzyme cocktail containing 25% ManA and 75% XynA. This increased the production of sugars approximately 13-fold. Analysis of the sugars produced by the synergistic hydrolysis of sugarcane bagasse (SCB) indicated the presence of xylose, indicating that the enzymes are potentially bifunctional under certain conditions. This study indicated that the use of mild pre-treatment conditions sufficiently removed a large portion of lignin without affecting the hemicellulose moiety of the SCB. This facilitated the potential use of the hemicellulose component for the production of valuable products (e.g. xylitol) in addition to the production of bioethanol. Thus, the potential use of additional components of holocellulose may generate an additional biotechnological benefit and allow a certain degree of flexibility in the biofuel industry, depending on consumer and industrial needs.
- Full Text:
Effect of nanoparticles on the photophysicochemical behaviour of metallophthalocyanines
- Moeno, Sharon Keitumetse Gail Mpheletso
- Authors: Moeno, Sharon Keitumetse Gail Mpheletso
- Date: 2011 , 2011-03-30
- Subjects: Phthalocyanines Nanoparticles Photochemistry Quantum dots
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4310 , http://hdl.handle.net/10962/d1004968
- Description: The synthesis, spectroscopic characterization, and studies of the photophysicochemical behaviour of selective anionic, cationic and neutral metallophthallocyanine (MPc) complexes were carried out and the results are presented herein. Studies on the effect of the central metal ion, the solvent used and the presence of nanoparticles on the photophysicochemical properties were conducted. The findings showed that the photophysicochemical parameters were mostly enhanced in the presence of central metal ions of high atomic numbers and also in the presence of nanoparticles. It was also observed that solvents that encouraged the monomericity of the MPc complexes also lead to improved photophysical and photochemical behaviour. CdTe quantum dots (QDs) stabilized with mercaptocarbonic acids were also observed to cause stimulated emission of the MPcs through Förster resonance energy transfer (FRET) thus acting as energy donors while the respective MPc acted as energy acceptors in all the FRET studies. FRET was observed following the photoexcitation of QDs for all monomeric anionic MPcs but it was also shown to occur for some cationic MPcs in organic media. Both the substituent and solvent used were found to exert a strong influence on the occurrence of FRET. Other cationic MPcs however showed different behaviour in the presence of the meraptocarbonic stabilized CdTe QDs; with the cationic porphyrazine giving clear indications of Pc ring reduction. The rest of the cationic MPcs did not give clear evidence of Pc ring reduction, instead they showed signs of aggregate formation possibly from the assembly of electrostatic ion pair complexes which could result in reduction of the quaternized pyridinium ring of the substituent. Both the QDs and the MPc complex emission spectra were significantly quenched for each in the presence of the other. Stern-Volmer quenching studies indicated that both static and dynamic quenching of the QDs in the presence of MPcs took place. The fluorescence lifetimes of the mercaptopropionic acid (MPA) capped CdTe QDs in the presence of various MPc complexes showed quenching of mostly the longer lifetimes of the QDs in the presence of MPcs suggesting that the surface defects and states are involved in the interaction of the QDs and MPcs. An MPc complex terminating in thio tethers was employed in the conjugation to AuNPs. Spectroscopic and microscopic studies confirmed the formation of the MPc-AuNP conjugate which was also shown to exhibit improved photophysicochemical properties compared to the free MPc.
- Full Text:
- Authors: Moeno, Sharon Keitumetse Gail Mpheletso
- Date: 2011 , 2011-03-30
- Subjects: Phthalocyanines Nanoparticles Photochemistry Quantum dots
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4310 , http://hdl.handle.net/10962/d1004968
- Description: The synthesis, spectroscopic characterization, and studies of the photophysicochemical behaviour of selective anionic, cationic and neutral metallophthallocyanine (MPc) complexes were carried out and the results are presented herein. Studies on the effect of the central metal ion, the solvent used and the presence of nanoparticles on the photophysicochemical properties were conducted. The findings showed that the photophysicochemical parameters were mostly enhanced in the presence of central metal ions of high atomic numbers and also in the presence of nanoparticles. It was also observed that solvents that encouraged the monomericity of the MPc complexes also lead to improved photophysical and photochemical behaviour. CdTe quantum dots (QDs) stabilized with mercaptocarbonic acids were also observed to cause stimulated emission of the MPcs through Förster resonance energy transfer (FRET) thus acting as energy donors while the respective MPc acted as energy acceptors in all the FRET studies. FRET was observed following the photoexcitation of QDs for all monomeric anionic MPcs but it was also shown to occur for some cationic MPcs in organic media. Both the substituent and solvent used were found to exert a strong influence on the occurrence of FRET. Other cationic MPcs however showed different behaviour in the presence of the meraptocarbonic stabilized CdTe QDs; with the cationic porphyrazine giving clear indications of Pc ring reduction. The rest of the cationic MPcs did not give clear evidence of Pc ring reduction, instead they showed signs of aggregate formation possibly from the assembly of electrostatic ion pair complexes which could result in reduction of the quaternized pyridinium ring of the substituent. Both the QDs and the MPc complex emission spectra were significantly quenched for each in the presence of the other. Stern-Volmer quenching studies indicated that both static and dynamic quenching of the QDs in the presence of MPcs took place. The fluorescence lifetimes of the mercaptopropionic acid (MPA) capped CdTe QDs in the presence of various MPc complexes showed quenching of mostly the longer lifetimes of the QDs in the presence of MPcs suggesting that the surface defects and states are involved in the interaction of the QDs and MPcs. An MPc complex terminating in thio tethers was employed in the conjugation to AuNPs. Spectroscopic and microscopic studies confirmed the formation of the MPc-AuNP conjugate which was also shown to exhibit improved photophysicochemical properties compared to the free MPc.
- Full Text:
Effects of colours, shapes and icons on performance and familiarity
- Authors: Dambuza, Inga Yola
- Date: 2011
- Subjects: Industrial hygiene -- Research -- South Africa , Industrial safety -- Research -- South Africa , Industrial hygiene -- Standards -- South Africa , Human engineering -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5117 , http://hdl.handle.net/10962/d1005195 , Industrial hygiene -- Research -- South Africa , Industrial safety -- Research -- South Africa , Industrial hygiene -- Standards -- South Africa , Human engineering -- Research -- South Africa
- Description: Occupational injuries and illnesses remain to be a heavy burden on workers and employees in industrial developing and industrially developed societies, and health and safety in workplaces continues to be an important issue for ergonomists. Steps are being taken to stimulate health and safety agendas and to discover ways in which health and safety in industries can be improved. The main responsibility of employers is to provide employees with information, instructions and training that they required to carry out their work tasks in a healthy, practical and safe manner. The role of education as a countermeasure to occupational injury and illness is being re-examined by health and safety practitioners and safety training is being considered as a vital part of accident prevention strategies. Effective training programmes should guarantee that workers possess the skills they require to complete their tasks in a safe and healthy manner. Very little is known about the type and quality of training workers undergo and how that training affects the safety outcomes of companies. There has been an attempt over the past 20 years to increase the research on safety communications and a great deal of this research has been focused on safety warnings; with the greatest attention been placed on the components of safety signs, such as colours, size, shapes and icons. The effects of these components on comprehension with relation to age and education have not received the same amount of attention. The impact of familiarity on safety warnings with respect to age and education has also received very little attention; despite the knowledge that familiarity has been shown to increase the noticing of warnings and the comprehension of safety information. Despite the increase in the research on safety communication, the literature and research in South Africa is scarce. Studies present in South Africa do not encompass the comprehension of safety signs or the ability of individuals with different age and education levels to learn the information included in the signs. Due to the multi-linguistic nature of South Africa and the fact that South Africa is an Industrially Developing Country (IDC) with high levels of illiteracy, issues such as the comprehension of safety information must be addressed. Therefore, the objectives of this study were to investigate the effects of safety sign attributes on learning and familiarity, in subjects that differed in age and education levels. These effects were investigated through measuring the reaction and response times of the different subject groups, as well as the number of components in the safety signs that were recalled correctly. The combined results of these responses were used as a measure for familiarity. A set of signs was designed for the study by the researcher using three different colours, three different shapes, three different icons and text. Certain variables were omitted from some signs to create the test pool and the eight conditions that were tested in a laboratory setting. Each condition contained different components of the designed signs and 60 subjects were used to test these conditions. The subjects were placed in groups according to their age and level of education. Subjects were required to learn a set of 64 signs, either “With Occlusion” or “Without Occlusion”, and asked to recall the meanings of the components in the signs. Reaction time, response time and error rate were measured from the responses. The results showed that the conditions resulted in different reaction times, response times and error rates for all subjects. The signs containing a combination of shapes and text resulted in the best performance. Age and education were found to have a significant effect on various performance criteria as did the method in which the signs were displayed (Occlusion and No Occlusion). The increased repetitions and sessions elicited lower reaction times, response times and error rates. The conclusions drawn from this study suggest that different attributes be considered carefully when subjects are expected to learn and recall information in safety signs. The results also highlighted the need to increase the exposure of individuals to safety signs in order to increase familiarity and ultimately improve the recall and comprehension of the attributes.
- Full Text:
- Authors: Dambuza, Inga Yola
- Date: 2011
- Subjects: Industrial hygiene -- Research -- South Africa , Industrial safety -- Research -- South Africa , Industrial hygiene -- Standards -- South Africa , Human engineering -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5117 , http://hdl.handle.net/10962/d1005195 , Industrial hygiene -- Research -- South Africa , Industrial safety -- Research -- South Africa , Industrial hygiene -- Standards -- South Africa , Human engineering -- Research -- South Africa
- Description: Occupational injuries and illnesses remain to be a heavy burden on workers and employees in industrial developing and industrially developed societies, and health and safety in workplaces continues to be an important issue for ergonomists. Steps are being taken to stimulate health and safety agendas and to discover ways in which health and safety in industries can be improved. The main responsibility of employers is to provide employees with information, instructions and training that they required to carry out their work tasks in a healthy, practical and safe manner. The role of education as a countermeasure to occupational injury and illness is being re-examined by health and safety practitioners and safety training is being considered as a vital part of accident prevention strategies. Effective training programmes should guarantee that workers possess the skills they require to complete their tasks in a safe and healthy manner. Very little is known about the type and quality of training workers undergo and how that training affects the safety outcomes of companies. There has been an attempt over the past 20 years to increase the research on safety communications and a great deal of this research has been focused on safety warnings; with the greatest attention been placed on the components of safety signs, such as colours, size, shapes and icons. The effects of these components on comprehension with relation to age and education have not received the same amount of attention. The impact of familiarity on safety warnings with respect to age and education has also received very little attention; despite the knowledge that familiarity has been shown to increase the noticing of warnings and the comprehension of safety information. Despite the increase in the research on safety communication, the literature and research in South Africa is scarce. Studies present in South Africa do not encompass the comprehension of safety signs or the ability of individuals with different age and education levels to learn the information included in the signs. Due to the multi-linguistic nature of South Africa and the fact that South Africa is an Industrially Developing Country (IDC) with high levels of illiteracy, issues such as the comprehension of safety information must be addressed. Therefore, the objectives of this study were to investigate the effects of safety sign attributes on learning and familiarity, in subjects that differed in age and education levels. These effects were investigated through measuring the reaction and response times of the different subject groups, as well as the number of components in the safety signs that were recalled correctly. The combined results of these responses were used as a measure for familiarity. A set of signs was designed for the study by the researcher using three different colours, three different shapes, three different icons and text. Certain variables were omitted from some signs to create the test pool and the eight conditions that were tested in a laboratory setting. Each condition contained different components of the designed signs and 60 subjects were used to test these conditions. The subjects were placed in groups according to their age and level of education. Subjects were required to learn a set of 64 signs, either “With Occlusion” or “Without Occlusion”, and asked to recall the meanings of the components in the signs. Reaction time, response time and error rate were measured from the responses. The results showed that the conditions resulted in different reaction times, response times and error rates for all subjects. The signs containing a combination of shapes and text resulted in the best performance. Age and education were found to have a significant effect on various performance criteria as did the method in which the signs were displayed (Occlusion and No Occlusion). The increased repetitions and sessions elicited lower reaction times, response times and error rates. The conclusions drawn from this study suggest that different attributes be considered carefully when subjects are expected to learn and recall information in safety signs. The results also highlighted the need to increase the exposure of individuals to safety signs in order to increase familiarity and ultimately improve the recall and comprehension of the attributes.
- Full Text:
Effects of habitat patch size and isolation on the population structure of two siphonarian limpets
- Authors: Johnson, Linda Gail
- Date: 2011
- Subjects: Siphonaria , Limpets , Population biology , Marine ecology , Habitat selection , Animals -- Dispersal , Ecological heterogeneity , Animal populations , Biodiversity
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5679 , http://hdl.handle.net/10962/d1005364 , Siphonaria , Limpets , Population biology , Marine ecology , Habitat selection , Animals -- Dispersal , Ecological heterogeneity , Animal populations , Biodiversity
- Description: Habitat fragmentation is a fundamental process that determines trends and patterns of distribution and density of organisms. These patterns and trends have been the focus of numerous terrestrial and marine studies and have led to the development of several explanatory hypotheses. Systems and organisms are dynamic and no single hypothesis has adequately accounted for these observed trends. It is therefore important to understand the interaction of these processes and patterns to explain the mechanisms controlling population dynamics. The main aim of this thesis was to test the effect of patch size and isolation on organisms with different modes of dispersal. Mode of dispersal has previously been examined as a factor influencing the effects that habitat fragmentation has on organisms. Very few studies have, however, examined the mode of dispersal of marine organisms because it has long been assumed that marine animals are not directly influenced by habitat fragmentation because of large-scale dispersal. I used two co-occurring species of siphonariid limpets with different modes of dispersal to highlight that not only are marine organisms affected by habitat fragmentation but that they are affected in different ways. The two species of limpet, Siphonaria serrata and Siphonaria concinna, are found within the same habitat and have the same geographic range along the South African coastline, however, they have different modes of dispersal and development. The effect of patch size on organism density has been examined to a great extent with varied results. This study investigated whether habitat patch size played a key role in determining population density and limpet body sizes. The two species are found on the eastern and southern coasts of South Africa were examined across this entire biogeographic range. Patch size was found to have a significant effect on population density of the pelagic developer, S. concinna, but not the direct developing S. serrata. Patch size did play a role in determining limpet body size for both species. S. concinna body size was proposed to be effected directly by patch size whilst S. serrata body size was proposed to be affected indirectly by the effects of the S. concinna densities. The same patterns and trends were observed at five of the seven examined regions across the biogeographic range. The trends observed for S. concinna with respect to patch size conform to the source-sink hypothesis with large habitat patches acting as the source populations whilst the small habitat patches acted as the sink populations. Many previous studies have focused on the effects of habitat patch size at one point in time or over one season. I tested the influence of habitat patch size on the two species of limpets over a period of twelve months to determine whether the trends observed were consistent over time or whether populations varied with time. S. concinna showed a consistently significant difference between small and large patches; whilst S. serrata did not follow a consistent pattern. The mode of dispersal for the two limpets was used to explain the different trends shown by the two species. This examination allowed for the determining of source and sink populations for S. concinna through the examination of fluctuations in limpet body sizes and population densities at small and large habitat patches over twelve months. The direct developing S. serrata trends could not be explained using source-sink theory, as populations were independent from one another. S. serrata demonstrated body size differences at small and large patches which, may be explained by interspecific and intraspecific competition. Habitat isolation is known to play an important role in determining the structure of assemblages and the densities of populations. In this study the population density of the pelagic developing S. concinna showed a weak influence of degree of isolation whilst that of the direct developing S. serrata did not, which may be because of habitat patches along the South African coastline not having great enough degrees of isolation. The population size-structure was influenced directly influenced by isolation for S. concinna, whilst the different population size structure for S. serrata may be explained by assemblage co-dependence. The mode of dispersal showed effects on the relationship of population density and population size-structure with habitat size and isolation. This study indicates the importance of investigating patterns and processes across a range of spatial and temporal scales to gain a comprehensive understanding of factors effecting intertidal organisms.
- Full Text:
- Authors: Johnson, Linda Gail
- Date: 2011
- Subjects: Siphonaria , Limpets , Population biology , Marine ecology , Habitat selection , Animals -- Dispersal , Ecological heterogeneity , Animal populations , Biodiversity
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5679 , http://hdl.handle.net/10962/d1005364 , Siphonaria , Limpets , Population biology , Marine ecology , Habitat selection , Animals -- Dispersal , Ecological heterogeneity , Animal populations , Biodiversity
- Description: Habitat fragmentation is a fundamental process that determines trends and patterns of distribution and density of organisms. These patterns and trends have been the focus of numerous terrestrial and marine studies and have led to the development of several explanatory hypotheses. Systems and organisms are dynamic and no single hypothesis has adequately accounted for these observed trends. It is therefore important to understand the interaction of these processes and patterns to explain the mechanisms controlling population dynamics. The main aim of this thesis was to test the effect of patch size and isolation on organisms with different modes of dispersal. Mode of dispersal has previously been examined as a factor influencing the effects that habitat fragmentation has on organisms. Very few studies have, however, examined the mode of dispersal of marine organisms because it has long been assumed that marine animals are not directly influenced by habitat fragmentation because of large-scale dispersal. I used two co-occurring species of siphonariid limpets with different modes of dispersal to highlight that not only are marine organisms affected by habitat fragmentation but that they are affected in different ways. The two species of limpet, Siphonaria serrata and Siphonaria concinna, are found within the same habitat and have the same geographic range along the South African coastline, however, they have different modes of dispersal and development. The effect of patch size on organism density has been examined to a great extent with varied results. This study investigated whether habitat patch size played a key role in determining population density and limpet body sizes. The two species are found on the eastern and southern coasts of South Africa were examined across this entire biogeographic range. Patch size was found to have a significant effect on population density of the pelagic developer, S. concinna, but not the direct developing S. serrata. Patch size did play a role in determining limpet body size for both species. S. concinna body size was proposed to be effected directly by patch size whilst S. serrata body size was proposed to be affected indirectly by the effects of the S. concinna densities. The same patterns and trends were observed at five of the seven examined regions across the biogeographic range. The trends observed for S. concinna with respect to patch size conform to the source-sink hypothesis with large habitat patches acting as the source populations whilst the small habitat patches acted as the sink populations. Many previous studies have focused on the effects of habitat patch size at one point in time or over one season. I tested the influence of habitat patch size on the two species of limpets over a period of twelve months to determine whether the trends observed were consistent over time or whether populations varied with time. S. concinna showed a consistently significant difference between small and large patches; whilst S. serrata did not follow a consistent pattern. The mode of dispersal for the two limpets was used to explain the different trends shown by the two species. This examination allowed for the determining of source and sink populations for S. concinna through the examination of fluctuations in limpet body sizes and population densities at small and large habitat patches over twelve months. The direct developing S. serrata trends could not be explained using source-sink theory, as populations were independent from one another. S. serrata demonstrated body size differences at small and large patches which, may be explained by interspecific and intraspecific competition. Habitat isolation is known to play an important role in determining the structure of assemblages and the densities of populations. In this study the population density of the pelagic developing S. concinna showed a weak influence of degree of isolation whilst that of the direct developing S. serrata did not, which may be because of habitat patches along the South African coastline not having great enough degrees of isolation. The population size-structure was influenced directly influenced by isolation for S. concinna, whilst the different population size structure for S. serrata may be explained by assemblage co-dependence. The mode of dispersal showed effects on the relationship of population density and population size-structure with habitat size and isolation. This study indicates the importance of investigating patterns and processes across a range of spatial and temporal scales to gain a comprehensive understanding of factors effecting intertidal organisms.
- Full Text:
Emplacement of the 2.44 Ga ultramafic layered Kemi intrusion, Finland PGE, geochemical and Sm-Nd isotopic implications
- Authors: Linkermann, Sean Aaron
- Date: 2011
- Subjects: Chromite -- Finland -- Kemi , Mining geology -- Finland -- Kemi , Geochemistry -- Finland -- Kemi , Petrology -- Finland -- Kemi
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4940 , http://hdl.handle.net/10962/d1005552 , Chromite -- Finland -- Kemi , Mining geology -- Finland -- Kemi , Geochemistry -- Finland -- Kemi , Petrology -- Finland -- Kemi
- Description: Europe’s largest chrome deposit is hosted by the 2.44 Ga Kemi ultramafic layered intrusion. The lower half of the intrusion consists of peridotites, pyroxenites and chromitite layers while the upper half consists of websterites, gabbronorites and leucogabbros. The mafic minerals of the lower and upper parts of the intrusion are altered to serpentine, chlorite, talc, amphiboles and carbonates. However, the original mineralogy is still preserved in the middle part of the intrusion. Earlier work on the Kemi intrusion concentrated mainly on the economically important chromitite layers and suggested that these layers were formed through contamination of a single pulse of primitive magma by underlying Archaean basement crustal material. The broad variations of the major element concentrations reflect variations in the mode of the Kemi rocks. The petrology, which shows olivine- and orthopyroxene-dominated rocks in the lower portion of the intrusion to plagioclase- and clinopyroxene-dominated rocks in the upper portion, shows a gross consistency with a fractional crystallization process.The incompatible elements are relatively enriched in the lower portion of the intrusion which is not consistent with a broad fractional crystallization process. These variations suggest that the ultramafic portion of the KemiIntrusion is relatively enriched in trapped liquid compared to the mafic portion.ε2.44 Nd values ranges from +4 (consistent with depleted mantle source) to -10 (indicating a contribution from Archaean crust). The lower peridotites, pyroxenites and websterites have ε2.44 Nd values ranging between depleted mantle signatures and -2, whereas the gabbroic cumulates have ε2.44 Nd values which cover a range from around -5 to -10. Nd isotopic variation in the lower part of the profile is punctuated by distinct spikes to lower ε2.44 Nd corresponding to the chromitite horizons. Both the lower and upper portions of the Kemi Intrusion show enrichment of LREEC1 relative to HREEC1. The LREEC1 enriched values start to increase markedly from about the 1000 meter mark and continue to increase in value towards the roof of the intrusion.The main enrichment of PGE (ΣPPGE = 55 to 148 ppb) occurs approximately 90 to 160 m above the basal contact, beginning within andcontinuing above the main chromitite ore horizon. The mantle-normalized PGE abundances of the main chromitite horizon and the peridotites and pyroxenites below it show enrichment of IPGEPM (Os + Ir + Ru) relative to PPGEPM (Rh + Pd + Pt). In contrast, the overlying rocks are characterised by enrichment of PPGEPM relative to IPGEPM. These PGE-patterns suggest the influence of two distinct controlling processes above and below the main chromitite reef.The isotopic data are consistent with the initial introduction of multiple pulses of depleted mantle-derived magma crystallising olivine and pyroxene. Before the parent magma was fed into the Kemi magma chamber, it underwent crustal contamination and assimilation in a staging chamber within the lower crust. Some of these pulses were “critically crustally contaminated”, inducing chromite saturation and precipitation. The modelling also predicts minor in-situ contamination of the parent magma in the Kemi chamber with its wall and roof rocks. Above the main chromitite layer (about 160 m above the basal contact), the chromite content decreases and the PPGEPM/IPGEPM values increase which is consistent with scavenging of the IPGE into the lowermost layers and/or evolving magma compositions. Above 1000 m, the isotopic and REE data indicate a new magma pulse which has also been extensively contaminated in the staging magma chamber before emplacement into the Kemi magma chamber. The contamination in the staging magma chamber increased which is reflected in a progressively larger crustal component towards the top of the Kemi Intrusion
- Full Text:
- Authors: Linkermann, Sean Aaron
- Date: 2011
- Subjects: Chromite -- Finland -- Kemi , Mining geology -- Finland -- Kemi , Geochemistry -- Finland -- Kemi , Petrology -- Finland -- Kemi
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4940 , http://hdl.handle.net/10962/d1005552 , Chromite -- Finland -- Kemi , Mining geology -- Finland -- Kemi , Geochemistry -- Finland -- Kemi , Petrology -- Finland -- Kemi
- Description: Europe’s largest chrome deposit is hosted by the 2.44 Ga Kemi ultramafic layered intrusion. The lower half of the intrusion consists of peridotites, pyroxenites and chromitite layers while the upper half consists of websterites, gabbronorites and leucogabbros. The mafic minerals of the lower and upper parts of the intrusion are altered to serpentine, chlorite, talc, amphiboles and carbonates. However, the original mineralogy is still preserved in the middle part of the intrusion. Earlier work on the Kemi intrusion concentrated mainly on the economically important chromitite layers and suggested that these layers were formed through contamination of a single pulse of primitive magma by underlying Archaean basement crustal material. The broad variations of the major element concentrations reflect variations in the mode of the Kemi rocks. The petrology, which shows olivine- and orthopyroxene-dominated rocks in the lower portion of the intrusion to plagioclase- and clinopyroxene-dominated rocks in the upper portion, shows a gross consistency with a fractional crystallization process.The incompatible elements are relatively enriched in the lower portion of the intrusion which is not consistent with a broad fractional crystallization process. These variations suggest that the ultramafic portion of the KemiIntrusion is relatively enriched in trapped liquid compared to the mafic portion.ε2.44 Nd values ranges from +4 (consistent with depleted mantle source) to -10 (indicating a contribution from Archaean crust). The lower peridotites, pyroxenites and websterites have ε2.44 Nd values ranging between depleted mantle signatures and -2, whereas the gabbroic cumulates have ε2.44 Nd values which cover a range from around -5 to -10. Nd isotopic variation in the lower part of the profile is punctuated by distinct spikes to lower ε2.44 Nd corresponding to the chromitite horizons. Both the lower and upper portions of the Kemi Intrusion show enrichment of LREEC1 relative to HREEC1. The LREEC1 enriched values start to increase markedly from about the 1000 meter mark and continue to increase in value towards the roof of the intrusion.The main enrichment of PGE (ΣPPGE = 55 to 148 ppb) occurs approximately 90 to 160 m above the basal contact, beginning within andcontinuing above the main chromitite ore horizon. The mantle-normalized PGE abundances of the main chromitite horizon and the peridotites and pyroxenites below it show enrichment of IPGEPM (Os + Ir + Ru) relative to PPGEPM (Rh + Pd + Pt). In contrast, the overlying rocks are characterised by enrichment of PPGEPM relative to IPGEPM. These PGE-patterns suggest the influence of two distinct controlling processes above and below the main chromitite reef.The isotopic data are consistent with the initial introduction of multiple pulses of depleted mantle-derived magma crystallising olivine and pyroxene. Before the parent magma was fed into the Kemi magma chamber, it underwent crustal contamination and assimilation in a staging chamber within the lower crust. Some of these pulses were “critically crustally contaminated”, inducing chromite saturation and precipitation. The modelling also predicts minor in-situ contamination of the parent magma in the Kemi chamber with its wall and roof rocks. Above the main chromitite layer (about 160 m above the basal contact), the chromite content decreases and the PPGEPM/IPGEPM values increase which is consistent with scavenging of the IPGE into the lowermost layers and/or evolving magma compositions. Above 1000 m, the isotopic and REE data indicate a new magma pulse which has also been extensively contaminated in the staging magma chamber before emplacement into the Kemi magma chamber. The contamination in the staging magma chamber increased which is reflected in a progressively larger crustal component towards the top of the Kemi Intrusion
- Full Text:
Ericoid mycorrhizal fungi and potential for inoculation of commercial berry species (Vaccinium corymbosium L.)
- Authors: Bizabani, Christine
- Date: 2011
- Subjects: Ericaceae , Mycorrhizas , Fynbos
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4136 , http://hdl.handle.net/10962/d1016127
- Description: Ericaceous plants are the richest growth form of the fynbos vegetation of South Africa. The fynbos is characterized by highly leached acidic soils, low mineral nutrients and climatically it is a winter rainfall and dry summer region. Ericoid mycorrhizal fungi associate with Erica species enhancing their ability to access essential nutrients for survival under unfavourable growth conditions. The aim of this study was to select local Ericaceae plant species and to isolate, identify and characterize the ericoid endophytes and assess these isolates as potential inocula for commercial berry species. Two ericaceous plants Erica cerinthoides L. and Erica demmissa Klotzsch ex Benth. were identified from the Mountain Drive area of Grahamstown, Eastern Cape. Root staining was used to confirm the mycorrhizal status of both plants. Hyphal coils typical of ericoid association were observed within the epidermal cells of the hair roots under a light microscope. The endophytes were successfully isolated in pure culture on 2% malt extract agar (MEA) and modified Fontana medium. Cultural morphology and microscopy were used for initial identification. Two slow growing isolates were selected. These isolates were further subjected to molecular identification; extracted DNA was amplified using ITS1 and ITS4 fungal primers. The rDNA gene internal transcriber spacer (ITS) was then sequenced and analyzed by comparison to sequences in the GenBank. On the basis of percentage sequence identity Lachnum Retz. species and Cadophora Lagerb. & Melin species were identified as the ericoid endophytes of E. cerinthoides and E. demmissa respectively. The optimum growth parameters of the fungal isolates were determined in 2% MEA incubated at varying temperatures and pH. It was established that both species had optimum growth at 27⁰C and pH 5. The Ericaceae species are sometimes found in metal contaminated sites were ericoid fungi have been proved to alleviate toxicity of their host. The fungal isolates were grown in increasing concentration of Cu²⁺ and Zn²⁺ in 2% MEA. The growth of Lachnum species decreased with increasing Zn²⁺ ions above 2.7 mM while Cadophora species showed a change in morphology and also decreased in growth with increased ion concentration. However there were no significant differences recorded in the growth of Cadophora and Lachnum species on increasing Cu²⁺ concentration. Lachnum and Cadophora isolates were formulated into a semi solid inoculum and inoculated onto micropropagated Vaccinni corymbosum L. plantlets of 5 different varieties. Colonization was low for all varieties, Elliott and Brightwell varieties recorded the highest colonization of 35% and 31% respectively. Lachnum species infected roots showed potential ericoid structures while the Cadophora inoculated plantlets had hyphal coils within the cortical cells typical of ericoid mycorrhizas. Inoculation significantly enhanced the shoot growth of Brightwell and Elliott varieties. The Chandler variety inoculated with Lachnum species showed improved shoot dry weight. The Bluecrop and Elliott varieties inoculated with Cadophora and Lachnum accumulated more root biomass. All inoculated Bluecrop plantlets had an improved canopy growth index. Brightwell plantlets inoculated with Lachnum species also had an enhanced canopy growth index. The growth responses were variable within varieties and between varieties. Treatments with the Cadophora and Lachnum have shown potential in the promotion of growth of the Blueberry species. The findings indicate the need to conduct trials under conditions which simulate the commercial growth conditions so as explore the optimum potential of the isolates.
- Full Text:
- Authors: Bizabani, Christine
- Date: 2011
- Subjects: Ericaceae , Mycorrhizas , Fynbos
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4136 , http://hdl.handle.net/10962/d1016127
- Description: Ericaceous plants are the richest growth form of the fynbos vegetation of South Africa. The fynbos is characterized by highly leached acidic soils, low mineral nutrients and climatically it is a winter rainfall and dry summer region. Ericoid mycorrhizal fungi associate with Erica species enhancing their ability to access essential nutrients for survival under unfavourable growth conditions. The aim of this study was to select local Ericaceae plant species and to isolate, identify and characterize the ericoid endophytes and assess these isolates as potential inocula for commercial berry species. Two ericaceous plants Erica cerinthoides L. and Erica demmissa Klotzsch ex Benth. were identified from the Mountain Drive area of Grahamstown, Eastern Cape. Root staining was used to confirm the mycorrhizal status of both plants. Hyphal coils typical of ericoid association were observed within the epidermal cells of the hair roots under a light microscope. The endophytes were successfully isolated in pure culture on 2% malt extract agar (MEA) and modified Fontana medium. Cultural morphology and microscopy were used for initial identification. Two slow growing isolates were selected. These isolates were further subjected to molecular identification; extracted DNA was amplified using ITS1 and ITS4 fungal primers. The rDNA gene internal transcriber spacer (ITS) was then sequenced and analyzed by comparison to sequences in the GenBank. On the basis of percentage sequence identity Lachnum Retz. species and Cadophora Lagerb. & Melin species were identified as the ericoid endophytes of E. cerinthoides and E. demmissa respectively. The optimum growth parameters of the fungal isolates were determined in 2% MEA incubated at varying temperatures and pH. It was established that both species had optimum growth at 27⁰C and pH 5. The Ericaceae species are sometimes found in metal contaminated sites were ericoid fungi have been proved to alleviate toxicity of their host. The fungal isolates were grown in increasing concentration of Cu²⁺ and Zn²⁺ in 2% MEA. The growth of Lachnum species decreased with increasing Zn²⁺ ions above 2.7 mM while Cadophora species showed a change in morphology and also decreased in growth with increased ion concentration. However there were no significant differences recorded in the growth of Cadophora and Lachnum species on increasing Cu²⁺ concentration. Lachnum and Cadophora isolates were formulated into a semi solid inoculum and inoculated onto micropropagated Vaccinni corymbosum L. plantlets of 5 different varieties. Colonization was low for all varieties, Elliott and Brightwell varieties recorded the highest colonization of 35% and 31% respectively. Lachnum species infected roots showed potential ericoid structures while the Cadophora inoculated plantlets had hyphal coils within the cortical cells typical of ericoid mycorrhizas. Inoculation significantly enhanced the shoot growth of Brightwell and Elliott varieties. The Chandler variety inoculated with Lachnum species showed improved shoot dry weight. The Bluecrop and Elliott varieties inoculated with Cadophora and Lachnum accumulated more root biomass. All inoculated Bluecrop plantlets had an improved canopy growth index. Brightwell plantlets inoculated with Lachnum species also had an enhanced canopy growth index. The growth responses were variable within varieties and between varieties. Treatments with the Cadophora and Lachnum have shown potential in the promotion of growth of the Blueberry species. The findings indicate the need to conduct trials under conditions which simulate the commercial growth conditions so as explore the optimum potential of the isolates.
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Evaluating the sustainable management of the State indigenous forests in the Eastern Cape Province
- Authors: Quvile, Nkosipendule
- Date: 2011
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:793 , http://hdl.handle.net/10962/d1004130
- Description: This research assesses the state of sustainability of State indigenous forests in the Eastern Cape and provides recommendations to improve their sustainability. The Eastern Cape Indigenous Forest Management Audit (ECIFMA) report of 2009 provided the primary data for this assessment (DAFF, 2009). The research was inspired by the fact that the global challenge of forestry destruction and degradation where the extent of forests is being reduced at an alarming rate of 6% annually. It became essential for global leaders to develop policies and strategies that sought to promote sustainable forest management. The monitoring of sustainability of forests was only possible through use of globally and nationally developed sets of criteria and indicators. Eleven forest estates responsible for the management of State indigenous forests in the Eastern Cape were selected for this research. The choice was influenced by the availability of audit data from the ECIFMA report of 2009. This report contained performance information of 41 indicators under 18 criteria for monitoring sustainable forest management as extracted from the PCI&S assessment checklist developed for monitoring the sustainability of indigenous forests in South Africa (DWAF, 2005). The data was refined using the MCA methods (ranking and scoring) as described by Mendoza and Prabhu (2000). These methods yielded to the determination of the performance of indicators of forest sustainability. It was thus important to conclude the research by responding to the following questions: • What is the state of sustainability of the State indigenous forests in the Eastern Cape? • What recommendations could be made to improve the sustainability of State indigenous forests? It was found that the State indigenous forests were not managed in a sustainable manner. The research report is concluded by providing concrete recommendations to improve forest sustainability.
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- Authors: Quvile, Nkosipendule
- Date: 2011
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:793 , http://hdl.handle.net/10962/d1004130
- Description: This research assesses the state of sustainability of State indigenous forests in the Eastern Cape and provides recommendations to improve their sustainability. The Eastern Cape Indigenous Forest Management Audit (ECIFMA) report of 2009 provided the primary data for this assessment (DAFF, 2009). The research was inspired by the fact that the global challenge of forestry destruction and degradation where the extent of forests is being reduced at an alarming rate of 6% annually. It became essential for global leaders to develop policies and strategies that sought to promote sustainable forest management. The monitoring of sustainability of forests was only possible through use of globally and nationally developed sets of criteria and indicators. Eleven forest estates responsible for the management of State indigenous forests in the Eastern Cape were selected for this research. The choice was influenced by the availability of audit data from the ECIFMA report of 2009. This report contained performance information of 41 indicators under 18 criteria for monitoring sustainable forest management as extracted from the PCI&S assessment checklist developed for monitoring the sustainability of indigenous forests in South Africa (DWAF, 2005). The data was refined using the MCA methods (ranking and scoring) as described by Mendoza and Prabhu (2000). These methods yielded to the determination of the performance of indicators of forest sustainability. It was thus important to conclude the research by responding to the following questions: • What is the state of sustainability of the State indigenous forests in the Eastern Cape? • What recommendations could be made to improve the sustainability of State indigenous forests? It was found that the State indigenous forests were not managed in a sustainable manner. The research report is concluded by providing concrete recommendations to improve forest sustainability.
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Exchange rate behavior in the cases of the Zambian Kwacha and Malawian Kwacha : is there misalignment?
- Magwizi, Brenda Thandekha, Rhodes University
- Authors: Magwizi, Brenda Thandekha , Rhodes University
- Date: 2011
- Subjects: Foreign exchange rates -- Zambia Foreign exchange rates -- Malawi International relations -- Case studies -- Zambia International relations -- Case studies -- Malawi
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:974 , http://hdl.handle.net/10962/d1002708
- Description: The exchange rate is the price of one currency against another currency or currencies of a group of countries. Real exchange rates are important because they show the external competitiveness of a country‟s economy. Thus, when the exchange rate of a country is misaligned, this will affect its trade, production and the welfare of people. This study analysed macroeconomic determinants of the real exchange rate and dynamic adjustment of the real exchange rate as a result of shocks to these determinants. The study also determined the extent of misalignment of the real exchange rate in Malawi and Zambia and identified variables that contributed to it. Such information is important to policy makers. Quarterly data were used for both countries from 1980:1-2008:4. The literature review identified those variables that determine the exchange rate and these include government consumption, foreign aid, net foreign assets, commodity prices, terms of trade, domestic credit, openness and the Balassa Samuelson effect (technological progress). To determine the long-run relationship between the exchange rate and its determinants, we employed the Johansen approach and the Vector Error Correction Model (VECM). For robustness check on the long-run and shortrun effects of determinants on the exchange rate, variance decomposition and impulse response analyses were used. Results in the study show that in Malawi for both models, an increase in LAID, LGCON and LTOT resulted in real exchange rate depreciation and increases in LDC, NFA and LNEER resulted in an appreciation. In Zambia, increases in LAID, LGCON, LOPEN and LTOT caused the real exchange rate to depreciate while increases in LDC, NFA and LCOPPER led to an appreciation. Lagged LREER and LNEER were found to have short run effects on the equilibrium exchange rate for Malawi and lagged LCOPPER and LDC for Zambia. Periods of exchange rate misalignment were found in both countries. It was also found that the coefficient of speed of adjustment in Malawi in models 1 and 2 indicate that 11% and 27% of the variation in the real exchange rate from its equilibrium adjust each quarter respectively. The speed of adjustment for Zambia in both models was 45% and 47% respectively, higher than that of Malawi. Foreign aid has proven to be important in exchange rate misalignment in both countries, though this was not really expected in the case of Zambia. Given these results, it may be of interest to policy makers to understand which variables impact most on the exchange rate and how misalignment due to these determinants can be minimised.
- Full Text:
- Authors: Magwizi, Brenda Thandekha , Rhodes University
- Date: 2011
- Subjects: Foreign exchange rates -- Zambia Foreign exchange rates -- Malawi International relations -- Case studies -- Zambia International relations -- Case studies -- Malawi
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:974 , http://hdl.handle.net/10962/d1002708
- Description: The exchange rate is the price of one currency against another currency or currencies of a group of countries. Real exchange rates are important because they show the external competitiveness of a country‟s economy. Thus, when the exchange rate of a country is misaligned, this will affect its trade, production and the welfare of people. This study analysed macroeconomic determinants of the real exchange rate and dynamic adjustment of the real exchange rate as a result of shocks to these determinants. The study also determined the extent of misalignment of the real exchange rate in Malawi and Zambia and identified variables that contributed to it. Such information is important to policy makers. Quarterly data were used for both countries from 1980:1-2008:4. The literature review identified those variables that determine the exchange rate and these include government consumption, foreign aid, net foreign assets, commodity prices, terms of trade, domestic credit, openness and the Balassa Samuelson effect (technological progress). To determine the long-run relationship between the exchange rate and its determinants, we employed the Johansen approach and the Vector Error Correction Model (VECM). For robustness check on the long-run and shortrun effects of determinants on the exchange rate, variance decomposition and impulse response analyses were used. Results in the study show that in Malawi for both models, an increase in LAID, LGCON and LTOT resulted in real exchange rate depreciation and increases in LDC, NFA and LNEER resulted in an appreciation. In Zambia, increases in LAID, LGCON, LOPEN and LTOT caused the real exchange rate to depreciate while increases in LDC, NFA and LCOPPER led to an appreciation. Lagged LREER and LNEER were found to have short run effects on the equilibrium exchange rate for Malawi and lagged LCOPPER and LDC for Zambia. Periods of exchange rate misalignment were found in both countries. It was also found that the coefficient of speed of adjustment in Malawi in models 1 and 2 indicate that 11% and 27% of the variation in the real exchange rate from its equilibrium adjust each quarter respectively. The speed of adjustment for Zambia in both models was 45% and 47% respectively, higher than that of Malawi. Foreign aid has proven to be important in exchange rate misalignment in both countries, though this was not really expected in the case of Zambia. Given these results, it may be of interest to policy makers to understand which variables impact most on the exchange rate and how misalignment due to these determinants can be minimised.
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Exchange rate pass-through to domestic prices in Kenya
- Authors: Mnjama, Gladys Susan
- Date: 2011
- Subjects: Kenya -- Economic conditions , Kenya -- Economic conditions -- Econometric models , Foreign exchange rates -- Kenya , Stocks -- Prices -- Kenya , Banks and banking -- Kenya , Cointegration , Econometrics , Inflation (Finance) -- Kenya
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:975 , http://hdl.handle.net/10962/d1002709 , Kenya -- Economic conditions , Kenya -- Economic conditions -- Econometric models , Foreign exchange rates -- Kenya , Stocks -- Prices -- Kenya , Banks and banking -- Kenya , Cointegration , Econometrics , Inflation (Finance) -- Kenya
- Description: In 1993, Kenya liberalised its trade policy and allowed the Kenyan Shillings to freely float. This openness has left Kenya's domestic prices vulnerable to the effects of exchange rate fluctuations. One of the objectives of the Central Bank of Kenya is to maintain inflation levels at sustainable levels. Thus it has become necessary to determine the influence that exchange rate changes have on domestic prices given that one of the major determinants of inflation is exchange rate movements. For this reason, this thesis examines the magnitude and speed of exchange rate pass-through (ERPT) to domestic prices in Kenya. In addition, it takes into account the direction and size of changes in the exchange rates to determine whether the exchange rate fluctuations are symmetric or asymmetric. The thesis uses quarterly data ranging from 1993:Ql - 2008:Q4 as it takes into account the period when the process of liberalization occurred. The empirical estimation was done in two stages. The first stage was estimated using the Johansen (1991) and (1995) co integration techniques and a vector error correction model (VECM). The second stage entailed estimating the impulse response and variance decomposition functions as well as conducting block exogeneity Wald tests. In determining the asymmetric aspect of the analysis, the study followed Pollard and Coughlin (2004) and Webber (2000) frameworks in analysing asymmetry with respect to appreciation and depreciation and large and small changes in the exchange rate to import prices. The results obtained showed that ERPT to Kenya is incomplete but relatively low at about 36 percent in the long run. In terms of asymmetry, the results showed that ERPT is found to be higher in periods of appreciation than depreciation. This is in support of market share and binding quantity constraints theory. In relation to size changes, the results show that size changes have no significant impact on ERPT in Kenya.
- Full Text:
- Authors: Mnjama, Gladys Susan
- Date: 2011
- Subjects: Kenya -- Economic conditions , Kenya -- Economic conditions -- Econometric models , Foreign exchange rates -- Kenya , Stocks -- Prices -- Kenya , Banks and banking -- Kenya , Cointegration , Econometrics , Inflation (Finance) -- Kenya
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:975 , http://hdl.handle.net/10962/d1002709 , Kenya -- Economic conditions , Kenya -- Economic conditions -- Econometric models , Foreign exchange rates -- Kenya , Stocks -- Prices -- Kenya , Banks and banking -- Kenya , Cointegration , Econometrics , Inflation (Finance) -- Kenya
- Description: In 1993, Kenya liberalised its trade policy and allowed the Kenyan Shillings to freely float. This openness has left Kenya's domestic prices vulnerable to the effects of exchange rate fluctuations. One of the objectives of the Central Bank of Kenya is to maintain inflation levels at sustainable levels. Thus it has become necessary to determine the influence that exchange rate changes have on domestic prices given that one of the major determinants of inflation is exchange rate movements. For this reason, this thesis examines the magnitude and speed of exchange rate pass-through (ERPT) to domestic prices in Kenya. In addition, it takes into account the direction and size of changes in the exchange rates to determine whether the exchange rate fluctuations are symmetric or asymmetric. The thesis uses quarterly data ranging from 1993:Ql - 2008:Q4 as it takes into account the period when the process of liberalization occurred. The empirical estimation was done in two stages. The first stage was estimated using the Johansen (1991) and (1995) co integration techniques and a vector error correction model (VECM). The second stage entailed estimating the impulse response and variance decomposition functions as well as conducting block exogeneity Wald tests. In determining the asymmetric aspect of the analysis, the study followed Pollard and Coughlin (2004) and Webber (2000) frameworks in analysing asymmetry with respect to appreciation and depreciation and large and small changes in the exchange rate to import prices. The results obtained showed that ERPT to Kenya is incomplete but relatively low at about 36 percent in the long run. In terms of asymmetry, the results showed that ERPT is found to be higher in periods of appreciation than depreciation. This is in support of market share and binding quantity constraints theory. In relation to size changes, the results show that size changes have no significant impact on ERPT in Kenya.
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Exchange rates behaviour in Ghana and Nigeria: is there a misalignment?
- Authors: Mapenda, Rufaro
- Date: 2011 , 2011-11-09
- Subjects: Foreign exchange rates -- Ghana , Foreign exchange rates -- Nigeria , Economic development -- Ghana , Economic development -- Nigeria , Foreign exchange administration -- Ghana , Foreign exchange administration -- Nigeria , International relations
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:976 , http://hdl.handle.net/10962/d1002710 , Foreign exchange rates -- Ghana , Foreign exchange rates -- Nigeria , Economic development -- Ghana , Economic development -- Nigeria , Foreign exchange administration -- Ghana , Foreign exchange administration -- Nigeria , International relations
- Description: Exchange rates are believed to be one of the major driving forces behind sustainable macroeconomic growth and it is therefore important to ensure that they are at an appropriate level. Exchange rate misalignment is a situation where the actual exchange rate differs significantly from its equilibrium value, resulting in either an overvalued or an undervalued currency. The problem with an undervalued currency is that it will increase the domestic price of tradable goods whereas an overvalued currency will cause a fall in the domestic prices of the tradable goods. Persistent exchange rate misalignment is thus expected to result in severe macroeconomic instability. The aim of this study is to estimate the equilibrium real exchange rate for both Ghana and Nigeria. After so doing, the equilibrium real exchange rate is compared to the actual real exchange rate, in order to assess the extent of real exchange rate misalignment in both countries, if any such exists. In order test the applicability of the equilibrium exchange rate models, the study draws from the simple monetary model as well as the Edwards (1989) and Montiel (1999) models. These models postulate that the variables which determine the real exchange rate are the terms of trade, trade restrictions, domestic interest rates, foreign aid inflow, income, money supply, world inflation, government consumption expenditure, world interest rates, capital controls and technological progress. Due to data limitations in Ghana and in Nigeria, not all the variables are utilised in the study. The study uses the Johansen (1995) model as well as the Vector Error Correction Model (VECM) to estimate the long- and the short-run relationships between the above-mentioned determinants and the real exchange rate. Thereafter the study employs the Hodrick-Prescott filter to estimate the permanent equilibrium exchange rate. The study estimates a real exchange rate model each for Ghana and Nigeria. Both the exchange rate models for Ghana and Nigeria provide evidence of exchange rate misalignment. The model for Ghana shows that from the first quarter of 1980 to the last quarter of 1983 the real exchange rate was overvalued; thereafter the exchange rate moved close to its equilibrium value and was generally undervalued with few and short-lived episodes of overvaluation. In regard to real exchange rate misalignment in Nigeria prior to the Structural Adjustment Program in 1986 there were episodes of undervaluation from the first quarter of 1980 to the first quarter of 1984 and overvaluation from the second quarter of 1984 to the third quarter of 1986; thereafter the exchange rate was generally and marginally undervalued.
- Full Text:
- Authors: Mapenda, Rufaro
- Date: 2011 , 2011-11-09
- Subjects: Foreign exchange rates -- Ghana , Foreign exchange rates -- Nigeria , Economic development -- Ghana , Economic development -- Nigeria , Foreign exchange administration -- Ghana , Foreign exchange administration -- Nigeria , International relations
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:976 , http://hdl.handle.net/10962/d1002710 , Foreign exchange rates -- Ghana , Foreign exchange rates -- Nigeria , Economic development -- Ghana , Economic development -- Nigeria , Foreign exchange administration -- Ghana , Foreign exchange administration -- Nigeria , International relations
- Description: Exchange rates are believed to be one of the major driving forces behind sustainable macroeconomic growth and it is therefore important to ensure that they are at an appropriate level. Exchange rate misalignment is a situation where the actual exchange rate differs significantly from its equilibrium value, resulting in either an overvalued or an undervalued currency. The problem with an undervalued currency is that it will increase the domestic price of tradable goods whereas an overvalued currency will cause a fall in the domestic prices of the tradable goods. Persistent exchange rate misalignment is thus expected to result in severe macroeconomic instability. The aim of this study is to estimate the equilibrium real exchange rate for both Ghana and Nigeria. After so doing, the equilibrium real exchange rate is compared to the actual real exchange rate, in order to assess the extent of real exchange rate misalignment in both countries, if any such exists. In order test the applicability of the equilibrium exchange rate models, the study draws from the simple monetary model as well as the Edwards (1989) and Montiel (1999) models. These models postulate that the variables which determine the real exchange rate are the terms of trade, trade restrictions, domestic interest rates, foreign aid inflow, income, money supply, world inflation, government consumption expenditure, world interest rates, capital controls and technological progress. Due to data limitations in Ghana and in Nigeria, not all the variables are utilised in the study. The study uses the Johansen (1995) model as well as the Vector Error Correction Model (VECM) to estimate the long- and the short-run relationships between the above-mentioned determinants and the real exchange rate. Thereafter the study employs the Hodrick-Prescott filter to estimate the permanent equilibrium exchange rate. The study estimates a real exchange rate model each for Ghana and Nigeria. Both the exchange rate models for Ghana and Nigeria provide evidence of exchange rate misalignment. The model for Ghana shows that from the first quarter of 1980 to the last quarter of 1983 the real exchange rate was overvalued; thereafter the exchange rate moved close to its equilibrium value and was generally undervalued with few and short-lived episodes of overvaluation. In regard to real exchange rate misalignment in Nigeria prior to the Structural Adjustment Program in 1986 there were episodes of undervaluation from the first quarter of 1980 to the first quarter of 1984 and overvaluation from the second quarter of 1984 to the third quarter of 1986; thereafter the exchange rate was generally and marginally undervalued.
- Full Text: