Extreme weather events in the Sneeuberg, Karoo, South Africa: a case study of the floods of 9 and 12 February 2011
- Fox, Roddy C, Rowntree, Kate M
- Authors: Fox, Roddy C , Rowntree, Kate M
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6672 , http://hdl.handle.net/10962/d1004468
- Description: Two destructive flood events occurred in rapid succession in the semi-arid Sneeuberg Mountains of the Karoo, South Africa in February 2011. The temporal and spatial characteristics of these two extreme events are examined in this paper through analysis of data from an unusually dense, and reliable, network of farm rain gauges. These analyses add to our understanding derived from existing rain gauge information. Comparisons are then made with patterns from a range of modeled products derived from remote sensed information: the Modern-Era Retrospective Analysis for Research and Applications (MERRA), the Tropical Rainfall Measuring Mission (TRMM) and the Global Land Data Assimilation System (GLDAS). We found that the first flood event was widespread and precipitation was related strongly to altitude. The second was highly localised, with no relationship to altitude. Both had very sharply peaked rainfall intensities. These findings are of significance to the studies of flooding and landscape change in the area as such events have become more pronounced over the past 50 yr and it is likely that this trend will accelerate. The modeled patterns are derived largely from remote sensing and we found that they are reliable for drawing out monthly and annual variations but they make noticeable underestimates. They are poor estimates, however, both for the spatial distribution of precipitation, and the short term trends as they struggle to estimate the impact of topography and other local forcing factors. This finding corroborates information derived from other analyses at broader spatial scales using more widely spread, established rain gauge stations. Ten percent of southern Africa has been classified as mountainous and these areas provide much of our water resources so our findings are significant to water managers throughout this and similar mountainous regions.
- Full Text:
- Authors: Fox, Roddy C , Rowntree, Kate M
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6672 , http://hdl.handle.net/10962/d1004468
- Description: Two destructive flood events occurred in rapid succession in the semi-arid Sneeuberg Mountains of the Karoo, South Africa in February 2011. The temporal and spatial characteristics of these two extreme events are examined in this paper through analysis of data from an unusually dense, and reliable, network of farm rain gauges. These analyses add to our understanding derived from existing rain gauge information. Comparisons are then made with patterns from a range of modeled products derived from remote sensed information: the Modern-Era Retrospective Analysis for Research and Applications (MERRA), the Tropical Rainfall Measuring Mission (TRMM) and the Global Land Data Assimilation System (GLDAS). We found that the first flood event was widespread and precipitation was related strongly to altitude. The second was highly localised, with no relationship to altitude. Both had very sharply peaked rainfall intensities. These findings are of significance to the studies of flooding and landscape change in the area as such events have become more pronounced over the past 50 yr and it is likely that this trend will accelerate. The modeled patterns are derived largely from remote sensing and we found that they are reliable for drawing out monthly and annual variations but they make noticeable underestimates. They are poor estimates, however, both for the spatial distribution of precipitation, and the short term trends as they struggle to estimate the impact of topography and other local forcing factors. This finding corroborates information derived from other analyses at broader spatial scales using more widely spread, established rain gauge stations. Ten percent of southern Africa has been classified as mountainous and these areas provide much of our water resources so our findings are significant to water managers throughout this and similar mountainous regions.
- Full Text:
Factors influencing the successful adoption of mobile commerce services
- De Sousa, Sergio Anthony David
- Authors: De Sousa, Sergio Anthony David
- Date: 2013
- Subjects: Mobile commerce Electronic commerce Wireless communication systems Mobile communication systems Computer networks
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1152 , http://hdl.handle.net/10962/d1008184
- Description: Mobile Commerce (MC) can be defined as any transaction carried out over a wireless network, using a wireless device, such as a mobile phone, and that has monetary value (Wang and Liao, 2007). MC is a rapidly developing industry in tenns of its technological capabilities. With these increasing developments, come greater forecasts of potential benefits to societies, economies, industries and individuals. However, the growth and development ofthe underlying MC technology, has not been met by the creation and adoption of the services meant to accompany MC. It is said that the success of MC will ultimately lie in its services. As MC Service Providers (MCSP) are responsible for delivering these MC Services (MCS), the success ofMC can be said to rest on them. In order for MCSs to be successfully adopted, both the initial use and continuous use thereof should be targeted. In other words those that have used MCSs (users) and those that have yet to use MCSs (non-users) should be targeted. It is thus pivotal that an understanding of the factors that generate MCS adoption be sought. This research purposed to uncover the factors that generate MCS adoption within the user and nonuser group. In defining successful adoption ofMCS's, two separate measures were used for each group. User satisfaction is a well accepted construct among researchers for measuring system success among users. User satisfaction is also accepted to be a detenninant of service re-use and loyalty. Intention to use is a measure used for MC success among non-users and is accepted to be a detenninant of actual use. Factors affecting both detenninants, user satisfaction and intention to use, were investigated. After a review ofliterature and current models, ten (10) factors were hypothesised to be significant factors in determining user satisfaction and intention to use namely: ease of use, cost, speed, personalisation, pennission, privacy, security, convenience, relationship (with MCSP) and awareness. A questionnaire was developed to test the hypothesised factors. Not all factors were proven to have a significant impact on both user satisfactions and intention to use. One main recommendation is that both initial and continuous adoption should be the focus ofMC strategy. Services that cater to specific user needs and offer convenience at a low cost should be offered. MCSPs can use the factors proved to be significant to generate and evaluate their service offering, to users and non users, to increase the probability of successful adoption from initial to continuous use. The research concludes that MCSPs need to begin to offer MCSs that meet user needs and add value to their lives in order to realise the professed potential ofMC.
- Full Text:
- Authors: De Sousa, Sergio Anthony David
- Date: 2013
- Subjects: Mobile commerce Electronic commerce Wireless communication systems Mobile communication systems Computer networks
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1152 , http://hdl.handle.net/10962/d1008184
- Description: Mobile Commerce (MC) can be defined as any transaction carried out over a wireless network, using a wireless device, such as a mobile phone, and that has monetary value (Wang and Liao, 2007). MC is a rapidly developing industry in tenns of its technological capabilities. With these increasing developments, come greater forecasts of potential benefits to societies, economies, industries and individuals. However, the growth and development ofthe underlying MC technology, has not been met by the creation and adoption of the services meant to accompany MC. It is said that the success of MC will ultimately lie in its services. As MC Service Providers (MCSP) are responsible for delivering these MC Services (MCS), the success ofMC can be said to rest on them. In order for MCSs to be successfully adopted, both the initial use and continuous use thereof should be targeted. In other words those that have used MCSs (users) and those that have yet to use MCSs (non-users) should be targeted. It is thus pivotal that an understanding of the factors that generate MCS adoption be sought. This research purposed to uncover the factors that generate MCS adoption within the user and nonuser group. In defining successful adoption ofMCS's, two separate measures were used for each group. User satisfaction is a well accepted construct among researchers for measuring system success among users. User satisfaction is also accepted to be a detenninant of service re-use and loyalty. Intention to use is a measure used for MC success among non-users and is accepted to be a detenninant of actual use. Factors affecting both detenninants, user satisfaction and intention to use, were investigated. After a review ofliterature and current models, ten (10) factors were hypothesised to be significant factors in determining user satisfaction and intention to use namely: ease of use, cost, speed, personalisation, pennission, privacy, security, convenience, relationship (with MCSP) and awareness. A questionnaire was developed to test the hypothesised factors. Not all factors were proven to have a significant impact on both user satisfactions and intention to use. One main recommendation is that both initial and continuous adoption should be the focus ofMC strategy. Services that cater to specific user needs and offer convenience at a low cost should be offered. MCSPs can use the factors proved to be significant to generate and evaluate their service offering, to users and non users, to increase the probability of successful adoption from initial to continuous use. The research concludes that MCSPs need to begin to offer MCSs that meet user needs and add value to their lives in order to realise the professed potential ofMC.
- Full Text:
Faecal source tracking and water quality in the Eastern Cape, South Africa
- Authors: Luyt, Catherine Diane
- Date: 2013
- Subjects: Water quality -- South Africa -- Grahamstown , Waterborne infection -- Management , Drinking water -- Contamination -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6052 , http://hdl.handle.net/10962/d1018242
- Description: Water quality is concerning as many still lack access to safe drinking water. Alternate sources such as rivers (FC up to 1600 CFUs/100 mL) and rainwater are often polluted. Rainwater tanks require maintenance to improve water quality, but could be used for non-potable purposes or irrigation. Grahamstown infrastructural failures initiate deviations from DWAF 1996 domestic water guidelines for microorganisms within the distribution system. Frequent testing can decrease risks of waterborne diseases. Limitations to this are inaccessibility of rural areas, distances from testing centres and costs. The low cost H2S strip test able to be used onsite by communities, may aid in risk assessment. H2S strip test results are not affected by sulphate (14 to 4240 mg/L) or nitrite (up to 47 mg/L). Transportation of the H2S strip tests between 10 and 32°C does not modify results significantly. Similarly to other studies: Klebsiella spp.; Enterobacter spp. and Serratia spp. were isolated from H2S strip tests. The mH2S strip test corresponds best with HPC in treated water, while in untreated river water it has approximately 90% correspondence with FCs, while survival of FC causes discrepancies with the H2S test after 22 days. A faecal coliform inactivation rate of 0.1 CFUs/ day, may be longer than many pathogens. Faecal source tracking, not currently practised in South Africa, could aid health risk assessments for disaster management, which would improve the NMMP programme. Bacterial survival times could propose the time period for which water is unsafe. Bifidobacteria and Rhodococcus are proposed to help identify the faecal pollution source. But enumeration of Rhodococcus is too lengthy (21 days). The tracking ratio of bifidobacteria (between 0.1 to 6.25) is not source definitive. The bifidobacteria survival rate, could indicator the time since faecal pollution. The bifidobacteria average survival rate is 2.3 CFUs per day for both groups. The culturability and selectivity of agar is still poor, with total bifidobacteria less selectively culturable. Enterococci overgrowth of TB was decreased by Beerens media. SUB is still useful to identify potential human faecal inputs. A single tracking method is thus not suitable alone, but requires a combination of techniques.
- Full Text:
- Authors: Luyt, Catherine Diane
- Date: 2013
- Subjects: Water quality -- South Africa -- Grahamstown , Waterborne infection -- Management , Drinking water -- Contamination -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6052 , http://hdl.handle.net/10962/d1018242
- Description: Water quality is concerning as many still lack access to safe drinking water. Alternate sources such as rivers (FC up to 1600 CFUs/100 mL) and rainwater are often polluted. Rainwater tanks require maintenance to improve water quality, but could be used for non-potable purposes or irrigation. Grahamstown infrastructural failures initiate deviations from DWAF 1996 domestic water guidelines for microorganisms within the distribution system. Frequent testing can decrease risks of waterborne diseases. Limitations to this are inaccessibility of rural areas, distances from testing centres and costs. The low cost H2S strip test able to be used onsite by communities, may aid in risk assessment. H2S strip test results are not affected by sulphate (14 to 4240 mg/L) or nitrite (up to 47 mg/L). Transportation of the H2S strip tests between 10 and 32°C does not modify results significantly. Similarly to other studies: Klebsiella spp.; Enterobacter spp. and Serratia spp. were isolated from H2S strip tests. The mH2S strip test corresponds best with HPC in treated water, while in untreated river water it has approximately 90% correspondence with FCs, while survival of FC causes discrepancies with the H2S test after 22 days. A faecal coliform inactivation rate of 0.1 CFUs/ day, may be longer than many pathogens. Faecal source tracking, not currently practised in South Africa, could aid health risk assessments for disaster management, which would improve the NMMP programme. Bacterial survival times could propose the time period for which water is unsafe. Bifidobacteria and Rhodococcus are proposed to help identify the faecal pollution source. But enumeration of Rhodococcus is too lengthy (21 days). The tracking ratio of bifidobacteria (between 0.1 to 6.25) is not source definitive. The bifidobacteria survival rate, could indicator the time since faecal pollution. The bifidobacteria average survival rate is 2.3 CFUs per day for both groups. The culturability and selectivity of agar is still poor, with total bifidobacteria less selectively culturable. Enterococci overgrowth of TB was decreased by Beerens media. SUB is still useful to identify potential human faecal inputs. A single tracking method is thus not suitable alone, but requires a combination of techniques.
- Full Text:
Falcipains as malarial drug targets
- Authors: Kanzi, Aquillah Mumo
- Date: 2013
- Subjects: Malaria Malaria -- Chemotherapy Plasmodium falciparum Antimalarials -- Development Cysteine proteinases Cysteine proteinases -- Inhibitors Papain Drug development Bioinformatics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3897 , http://hdl.handle.net/10962/d1003842
- Description: Malaria is an infectious disease caused by parasites of the Plasmodium genus with mortality rates of more than a million annually, hence a major global public health concern. Plasmodium falciparum (P. falciparum) accounts for over 90% of malaria incidence. Increased resistance to antimalarial drugs by the Plasmodium parasite, coupled with the lack of an effective malaria vaccine necessitates the urgent need for new research avenues to develop novel and more potent antimalarial drugs. This study focused on falcipains, a group of P. falciparum cysteine proteases that belong to the clan CA and papain family C1, that have emerged as potential drug targets due to their involvement in a range of crucial functions in the P. falciparum life cycle. Recently, falcipain-2 has been validated as a drug target but little is known of its Plasmodium orthologs. Currently, there are several falcipain inhibitors that have been identified, most of which are peptide based but none has proceeded to drug development due to associated poor pharmacological profiles and susceptibility to degradation by host cysteine proteases. Non-peptides inhibitors have been shown to be more stable in vivo but limited information exists. In vivo studies on falcipain-2 and falcipain-3 inhibitors have also been complicated by varying outcomes, thus a good understanding of the structural variations of falcipain Plasmodium orthologs at the active site could go a long way to ease in vivo results interpretation and effective inhibitor design. In this study, we use bioinformatics approaches to perform comparative sequence and structural analysis and molecular docking to characterize protein-inhibitor interactions of falcipain homologs at the active site. Known FP-2 and FP-3 small molecule nonpeptide inhibitors were used to identify residue variations and their effect on inhibitor binding. This was done with the aim of screening a collection of selected non-peptide compounds of South African natural origin to identify possible new inhibitor leads. Natural compounds with high binding affinities across all Plasmodium orthologs were identified. These compounds were then used to search the ZINC database for similar compounds which could have better binding affinities across all selected falcipain homologs. Compounds with high binding affinities across all Plasmodium orthologs were found.
- Full Text:
- Authors: Kanzi, Aquillah Mumo
- Date: 2013
- Subjects: Malaria Malaria -- Chemotherapy Plasmodium falciparum Antimalarials -- Development Cysteine proteinases Cysteine proteinases -- Inhibitors Papain Drug development Bioinformatics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3897 , http://hdl.handle.net/10962/d1003842
- Description: Malaria is an infectious disease caused by parasites of the Plasmodium genus with mortality rates of more than a million annually, hence a major global public health concern. Plasmodium falciparum (P. falciparum) accounts for over 90% of malaria incidence. Increased resistance to antimalarial drugs by the Plasmodium parasite, coupled with the lack of an effective malaria vaccine necessitates the urgent need for new research avenues to develop novel and more potent antimalarial drugs. This study focused on falcipains, a group of P. falciparum cysteine proteases that belong to the clan CA and papain family C1, that have emerged as potential drug targets due to their involvement in a range of crucial functions in the P. falciparum life cycle. Recently, falcipain-2 has been validated as a drug target but little is known of its Plasmodium orthologs. Currently, there are several falcipain inhibitors that have been identified, most of which are peptide based but none has proceeded to drug development due to associated poor pharmacological profiles and susceptibility to degradation by host cysteine proteases. Non-peptides inhibitors have been shown to be more stable in vivo but limited information exists. In vivo studies on falcipain-2 and falcipain-3 inhibitors have also been complicated by varying outcomes, thus a good understanding of the structural variations of falcipain Plasmodium orthologs at the active site could go a long way to ease in vivo results interpretation and effective inhibitor design. In this study, we use bioinformatics approaches to perform comparative sequence and structural analysis and molecular docking to characterize protein-inhibitor interactions of falcipain homologs at the active site. Known FP-2 and FP-3 small molecule nonpeptide inhibitors were used to identify residue variations and their effect on inhibitor binding. This was done with the aim of screening a collection of selected non-peptide compounds of South African natural origin to identify possible new inhibitor leads. Natural compounds with high binding affinities across all Plasmodium orthologs were identified. These compounds were then used to search the ZINC database for similar compounds which could have better binding affinities across all selected falcipain homologs. Compounds with high binding affinities across all Plasmodium orthologs were found.
- Full Text:
Familiar claims : representations of same-gendered families in South African mainstream news media
- Authors: Morison, Tracy , Reddy, Vasu
- Date: 2013
- Language: English
- Type: Book chapter
- Identifier: vital:6211 , http://hdl.handle.net/10962/d1003062
- Description: From the Introduction: There has been significant reform of South African legislation pertaining to same-gendered families. The Constitution supports the rights of gay men and lesbians to establish life partnerships or, more recently, to enter into civil unions, to adopt children, keep custody of their own children in divorce proceedings, and to undertake co-parenting of their created families. Despite—or maybe because of—these developments, public debate on these issues is as lively and vociferous as it has ever been. At the time of writing this chapter, for instance, a veteran journalist published a column in a national newspaper in which he denounced same-gendered family “arrangements” as “neither the norm nor ultimately desirable” (Mulholland, 2013). Children in same-gendered families must be informed of this, he claimed. His argument was unsupported, save for unsubstantiated claims regarding the unnaturalness of same-gendered families, which defy “the natural order of things”, and the vehement refusal that “same-sex matrimony is the same as that of heterosexuals” (Mulholland, 2013). Mulholland’s column, which met with outrage by various activists and academics, demonstrates some of the ideas that circulate in public discussion of same-gendered families: concerns regarding the differences between homosexual and heterosexual families and the effects that these ‘differences’ might have on children living in ‘alternative’ families. In this chapter, we examine the public discussion, focusing on South African print media as a key site where debate has occurred. Recognising that the discussion of LGBTI issues in South Africa has increased in visibility over time, focusing on stories about coming out, rights, transgressions, stigma, discrimination and violence, this chapter concentrates on the public discussion in local print media that centre on ‘alternative’ family arrangements that are in contrast to a traditional heterosexual nuclear family. Drawing on a selection of print media reportage, we examine the social and public discourses that underpin and resist normative meanings associated with ‘the family’ as a social unit and, specifically, how same-gendered families (often rendered invisible and pathologised) are constructed within this material. , C. Lubbe & J. Marnell (Eds.) 2013. Home affairs: rethinking lesbian, gay, bisexual & transgender families in contemporary South Africa. A copy of the book can be obtained from: http://www.jacana.co.za
- Full Text:
- Authors: Morison, Tracy , Reddy, Vasu
- Date: 2013
- Language: English
- Type: Book chapter
- Identifier: vital:6211 , http://hdl.handle.net/10962/d1003062
- Description: From the Introduction: There has been significant reform of South African legislation pertaining to same-gendered families. The Constitution supports the rights of gay men and lesbians to establish life partnerships or, more recently, to enter into civil unions, to adopt children, keep custody of their own children in divorce proceedings, and to undertake co-parenting of their created families. Despite—or maybe because of—these developments, public debate on these issues is as lively and vociferous as it has ever been. At the time of writing this chapter, for instance, a veteran journalist published a column in a national newspaper in which he denounced same-gendered family “arrangements” as “neither the norm nor ultimately desirable” (Mulholland, 2013). Children in same-gendered families must be informed of this, he claimed. His argument was unsupported, save for unsubstantiated claims regarding the unnaturalness of same-gendered families, which defy “the natural order of things”, and the vehement refusal that “same-sex matrimony is the same as that of heterosexuals” (Mulholland, 2013). Mulholland’s column, which met with outrage by various activists and academics, demonstrates some of the ideas that circulate in public discussion of same-gendered families: concerns regarding the differences between homosexual and heterosexual families and the effects that these ‘differences’ might have on children living in ‘alternative’ families. In this chapter, we examine the public discussion, focusing on South African print media as a key site where debate has occurred. Recognising that the discussion of LGBTI issues in South Africa has increased in visibility over time, focusing on stories about coming out, rights, transgressions, stigma, discrimination and violence, this chapter concentrates on the public discussion in local print media that centre on ‘alternative’ family arrangements that are in contrast to a traditional heterosexual nuclear family. Drawing on a selection of print media reportage, we examine the social and public discourses that underpin and resist normative meanings associated with ‘the family’ as a social unit and, specifically, how same-gendered families (often rendered invisible and pathologised) are constructed within this material. , C. Lubbe & J. Marnell (Eds.) 2013. Home affairs: rethinking lesbian, gay, bisexual & transgender families in contemporary South Africa. A copy of the book can be obtained from: http://www.jacana.co.za
- Full Text:
Farewell to Lawrence Schlemmer: initiator of quality-of-life studies in South Africa
- Authors: Moller, Valerie
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67175 , vital:29055 , https://doi.org/10.1007/s11205-011-9965-8
- Description: publisher version , Professor Lawrence Schlemmer, affectionately known as Lawrie, was the father of South Africa’s quality-of-life studies and social indicators movement. He died on 26 October 2011 at the age of 75 after a short illness. In 1978, Lawrence marched into my office at the Centre for Applied Social Sciences, University of Natal, brandishing two books. We need to do some work on quality of life in South Africa, he announced, before handing me the volumes. At the time, South Africa’s leaders assumed that smiling black faces meant that South Africans were happy with their lot in life under apartheid. Our surveys were to prove otherwise. That weekend was spent reading cover to cover the classic works by Frank Andrews, Angus Campbell and their colleagues. The next week we pored over lists of concerns voiced by South Africans which we later put to test in the field. In 1982, we submitted our findings by ‘slug’ post to the editor of Social Indicators Research. We received a letter by return mail from Alex Michalos to say he would publish our paper and we should not be too disappointed with our regression results!
- Full Text: false
- Authors: Moller, Valerie
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67175 , vital:29055 , https://doi.org/10.1007/s11205-011-9965-8
- Description: publisher version , Professor Lawrence Schlemmer, affectionately known as Lawrie, was the father of South Africa’s quality-of-life studies and social indicators movement. He died on 26 October 2011 at the age of 75 after a short illness. In 1978, Lawrence marched into my office at the Centre for Applied Social Sciences, University of Natal, brandishing two books. We need to do some work on quality of life in South Africa, he announced, before handing me the volumes. At the time, South Africa’s leaders assumed that smiling black faces meant that South Africans were happy with their lot in life under apartheid. Our surveys were to prove otherwise. That weekend was spent reading cover to cover the classic works by Frank Andrews, Angus Campbell and their colleagues. The next week we pored over lists of concerns voiced by South Africans which we later put to test in the field. In 1982, we submitted our findings by ‘slug’ post to the editor of Social Indicators Research. We received a letter by return mail from Alex Michalos to say he would publish our paper and we should not be too disappointed with our regression results!
- Full Text: false
Farmers’ perceptions of the impact of legislation on farm workers’ wages and working conditions: an Eastern Cape case study
- Roberts, Tamaryn, Antrobus, Geoffrey G
- Authors: Roberts, Tamaryn , Antrobus, Geoffrey G
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142911 , vital:38175 , DOI: 10.1080/03031853.2013.778464
- Description: The status of South African farm workers has changed significantly over the past five decades. Using data from three major surveys conducted between 1957 and 2008, an Eastern Cape district was used as a case study to assess farmers’ perceptions of the changes that had occurred, particularly as a result of legislation. Considering the changes, the impacts on the farm labour market and wage and non-wage working conditions are analysed. The legislation focused on includes the Extension of Security of Tenure Act 62 (ESTA) of 1997, the Basic Conditions of Employment Act 75 (BCEA) of 1997 and minimum wage legislation. Farmers believed legislation had both positive and negative effects, which were compounded by changes in the political and economic contexts. The case study reveals that government has a role in improving the status of farm labourers, with education and healthcare services requiring special attention. However, caution is needed to ensure that further reductions in farm employment are restricted.
- Full Text:
- Authors: Roberts, Tamaryn , Antrobus, Geoffrey G
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142911 , vital:38175 , DOI: 10.1080/03031853.2013.778464
- Description: The status of South African farm workers has changed significantly over the past five decades. Using data from three major surveys conducted between 1957 and 2008, an Eastern Cape district was used as a case study to assess farmers’ perceptions of the changes that had occurred, particularly as a result of legislation. Considering the changes, the impacts on the farm labour market and wage and non-wage working conditions are analysed. The legislation focused on includes the Extension of Security of Tenure Act 62 (ESTA) of 1997, the Basic Conditions of Employment Act 75 (BCEA) of 1997 and minimum wage legislation. Farmers believed legislation had both positive and negative effects, which were compounded by changes in the political and economic contexts. The case study reveals that government has a role in improving the status of farm labourers, with education and healthcare services requiring special attention. However, caution is needed to ensure that further reductions in farm employment are restricted.
- Full Text:
Fears and desires in South African crime fiction
- Authors: Naidu, Samantha
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:26323 , http://hdl.handle.net/10962/53765 , http://www.tandfonline.com/doi/abs/10.1080/03057070.2013.826070 , https://orcid.org/0000-0001-9456-8657
- Description: This article is a review of a burgeoning literary genre, South African crime fiction, as much as it is a review of specific texts. First, for the purposes of contextualisation and historicisation, an overview of the primary literature is provided. Then criticism and theories of extant crime fiction in mainly the UK and USA, of which South African crime fiction is a descendent, are outlined. This outline is followed by descriptions of two sub-genres (the crime thriller novel and the literary detective novel). Two exemplar texts, Devil’s Peak (2007) and Lost Ground (2011) are then reviewed. The artistic merit of the respective sub-genres and their capacity for social analysis is also considered. The article ends with some brief inferences and the claim that the credibility and heft of this popular literary genre have been established
- Full Text:
- Authors: Naidu, Samantha
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:26323 , http://hdl.handle.net/10962/53765 , http://www.tandfonline.com/doi/abs/10.1080/03057070.2013.826070 , https://orcid.org/0000-0001-9456-8657
- Description: This article is a review of a burgeoning literary genre, South African crime fiction, as much as it is a review of specific texts. First, for the purposes of contextualisation and historicisation, an overview of the primary literature is provided. Then criticism and theories of extant crime fiction in mainly the UK and USA, of which South African crime fiction is a descendent, are outlined. This outline is followed by descriptions of two sub-genres (the crime thriller novel and the literary detective novel). Two exemplar texts, Devil’s Peak (2007) and Lost Ground (2011) are then reviewed. The artistic merit of the respective sub-genres and their capacity for social analysis is also considered. The article ends with some brief inferences and the claim that the credibility and heft of this popular literary genre have been established
- Full Text:
Female changes : the violation and violence of women in Ovid's Metamorphoses
- Authors: Champanis, Leigh Alexandra
- Date: 2013
- Subjects: Ovid, 43 B.C. - 17 or 18 A.D. -- Criticism and interpretation Ovid, 43 B.C. - 17 or 18 A.D. -- Metamorphoses Rape Women -- Violence against Violence in women
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3614 , http://hdl.handle.net/10962/d1006024
- Description: Ovid’s interest in women and their lives is apparent throughout his texts, but is especially so in the Metamorphoses. This study analyses the violation and violence of women in the Roman poet’s epic and sets out to uncover the governing social mores and values that perhaps shaped the representations of women in the text. It examines how Ovid’s narratives may betray his values and attitudes and those of his audience as well as looking at the various ways that the poet and his rape episodes have been read. After surveying the literature on rape in Ovid’s Metamorphoses, Ars Amatoria and the Fasti, a brief historical context for the Metamorphoses is provided; women’s lives in Rome, the rape laws that existed during this time, as well as Roman sexuality are then examined. After this, a close textual analysis of different rape episodes in the Metamorphoses is presented, including the episodes of nymphs as victims, the silencing of rape victims and sexually ‘aggressive’ women, in order to reveal and examine the patterns that emerge. While Ovid’s intentions and attitudes towards women, as they are found in the Metamorphoses, have been read by some as sympathetic, by others as misogynistic and still others as more neutral, it is concluded that, although there is space for various readings, as a poet, Ovid was ‘opportunistic’ in his choice of materia and, above all, he wished to stimulate and delight his audience. While his personal values may not necessarily be reflected in his works and his readers may never know the ‘true’ intentions behind the poem, the Metamorphoses does hold up a mirror to the negative treatment of women and exposes the gender inequalities that existed during Ovid’s time. As a poet, however, Ovid’s conceived role is to entertain his audience and despite his somewhat problematic treatment of women and rape victims, he does just that.
- Full Text:
- Authors: Champanis, Leigh Alexandra
- Date: 2013
- Subjects: Ovid, 43 B.C. - 17 or 18 A.D. -- Criticism and interpretation Ovid, 43 B.C. - 17 or 18 A.D. -- Metamorphoses Rape Women -- Violence against Violence in women
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3614 , http://hdl.handle.net/10962/d1006024
- Description: Ovid’s interest in women and their lives is apparent throughout his texts, but is especially so in the Metamorphoses. This study analyses the violation and violence of women in the Roman poet’s epic and sets out to uncover the governing social mores and values that perhaps shaped the representations of women in the text. It examines how Ovid’s narratives may betray his values and attitudes and those of his audience as well as looking at the various ways that the poet and his rape episodes have been read. After surveying the literature on rape in Ovid’s Metamorphoses, Ars Amatoria and the Fasti, a brief historical context for the Metamorphoses is provided; women’s lives in Rome, the rape laws that existed during this time, as well as Roman sexuality are then examined. After this, a close textual analysis of different rape episodes in the Metamorphoses is presented, including the episodes of nymphs as victims, the silencing of rape victims and sexually ‘aggressive’ women, in order to reveal and examine the patterns that emerge. While Ovid’s intentions and attitudes towards women, as they are found in the Metamorphoses, have been read by some as sympathetic, by others as misogynistic and still others as more neutral, it is concluded that, although there is space for various readings, as a poet, Ovid was ‘opportunistic’ in his choice of materia and, above all, he wished to stimulate and delight his audience. While his personal values may not necessarily be reflected in his works and his readers may never know the ‘true’ intentions behind the poem, the Metamorphoses does hold up a mirror to the negative treatment of women and exposes the gender inequalities that existed during Ovid’s time. As a poet, however, Ovid’s conceived role is to entertain his audience and despite his somewhat problematic treatment of women and rape victims, he does just that.
- Full Text:
Fig wasps (Hymenoptera: Chalcidoidea: Agaonidae, Pteromalidae) associated with Asian fig trees (Ficus, Moraceae) in southern Africa: Asian followers and African colonists: Insecta: Hymenoptera
- Van Noort, Simon, Wang, Rong, Compton, Stephen G
- Authors: Van Noort, Simon , Wang, Rong , Compton, Stephen G
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/479048 , vital:78255 , https://hdl.handle.net/10520/EJC143130
- Description: The Asian and Indo-Australasian fig tree species Ficus microcarpa and F. religiosa are widely-planted street and garden ornamentals in southern Africa and elsewhere. Like other fig trees, they depend for pollination on host specific fig wasps (Agaonidae). Their pollinators have also been widely introduced, and this allows the trees to become naturalised weeds. Both trees also support numerous non-pollinating fig wasps that can reduce seed or pollinator numbers, and a sub-set of these assemblages also now have wide distributions outside their native range. Two South African pollinators (Elisabethiella baijnathi, E. stuckenbergi), a galler (Otitesella uluzi) and a parasitoid (Sycoryctes species) occasionally succeed in reproducing in the figs of F. microcarpa, but in very small numbers.
- Full Text:
- Authors: Van Noort, Simon , Wang, Rong , Compton, Stephen G
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/479048 , vital:78255 , https://hdl.handle.net/10520/EJC143130
- Description: The Asian and Indo-Australasian fig tree species Ficus microcarpa and F. religiosa are widely-planted street and garden ornamentals in southern Africa and elsewhere. Like other fig trees, they depend for pollination on host specific fig wasps (Agaonidae). Their pollinators have also been widely introduced, and this allows the trees to become naturalised weeds. Both trees also support numerous non-pollinating fig wasps that can reduce seed or pollinator numbers, and a sub-set of these assemblages also now have wide distributions outside their native range. Two South African pollinators (Elisabethiella baijnathi, E. stuckenbergi), a galler (Otitesella uluzi) and a parasitoid (Sycoryctes species) occasionally succeed in reproducing in the figs of F. microcarpa, but in very small numbers.
- Full Text:
First year student performance in a test for computational thinking
- Gouws, Lindsey Ann, Bradshaw, Karen L, Wentworth, Peter E
- Authors: Gouws, Lindsey Ann , Bradshaw, Karen L , Wentworth, Peter E
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/477618 , vital:78104 , ISBN 9781450321129 , https://doi.org/10.1145/2513456.2513484
- Description: Computational thinking, a form of thinking and problem solving within computer science, has become a popular focus of research on computer science education. In this paper, we attempt to investigate the role that computational thinking plays in the experience of introductory computer science students at a South African university. To this end, we have designed and administered a test for computational thinking ability, and contrasted the results of this test with the class marks for the students involved. The results of this test give us an initial view of the abilities that students possess when entering the computer science course. The results indicate that students who performed well in the assessment have a favourable pass rate for their class tests, and specific areas of weakness have been identified. Finally, we describe the plan for a follow-up test to take place at the end of the course to determine how students' abilities have changed over a semester of studies.
- Full Text:
- Authors: Gouws, Lindsey Ann , Bradshaw, Karen L , Wentworth, Peter E
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/477618 , vital:78104 , ISBN 9781450321129 , https://doi.org/10.1145/2513456.2513484
- Description: Computational thinking, a form of thinking and problem solving within computer science, has become a popular focus of research on computer science education. In this paper, we attempt to investigate the role that computational thinking plays in the experience of introductory computer science students at a South African university. To this end, we have designed and administered a test for computational thinking ability, and contrasted the results of this test with the class marks for the students involved. The results of this test give us an initial view of the abilities that students possess when entering the computer science course. The results indicate that students who performed well in the assessment have a favourable pass rate for their class tests, and specific areas of weakness have been identified. Finally, we describe the plan for a follow-up test to take place at the end of the course to determine how students' abilities have changed over a semester of studies.
- Full Text:
Fish and fisheries of Bangweulu wetlands, Zambia
- Huchzermeyer, Carl Friedrich
- Authors: Huchzermeyer, Carl Friedrich
- Date: 2013
- Subjects: Bangweulu Swamps (Zambia) , Fisheries -- Zambia -- Bangweulu Swamps , Fishes -- Zambia -- Bangweulu Swamps , Fishery management -- Zambia -- Bangweulu Swamps , Fishing -- Zambia -- Bangweulu Swamps , Fishing -- Economic aspects -- Zambia -- Bangweulu Swamps , Fish stock assessment -- Zambia -- Bangweulu Swamps , Fish as food -- Zambia -- Bangweulu Swamps , Conservation of natural resources -- Zambia -- Bangweulu Swamps , Sustainable development -- Zambia -- Bangweulu Swamps
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5203 , http://hdl.handle.net/10962/d1003927 , Bangweulu Swamps (Zambia) , Fisheries -- Zambia -- Bangweulu Swamps , Fishes -- Zambia -- Bangweulu Swamps , Fishery management -- Zambia -- Bangweulu Swamps , Fishing -- Zambia -- Bangweulu Swamps , Fishing -- Economic aspects -- Zambia -- Bangweulu Swamps , Fish stock assessment -- Zambia -- Bangweulu Swamps , Fish as food -- Zambia -- Bangweulu Swamps , Conservation of natural resources -- Zambia -- Bangweulu Swamps , Sustainable development -- Zambia -- Bangweulu Swamps
- Description: Bangweulu Wetlands is a 6000 km² public-private-partnership conservation area in northeastern Zambia, lying on the south-eastern margins of the Bangweulu Swamps, Congo River system. The area is important for wildlife conservation, tourism and as a fishing ground for the local inhabitants. This study provides a baseline of the fish and fisheries of this area. The conservation area is situated on the transition zone between woodland, floodplain and swamp. A total of 42 fish species representing 12 taxonomic families were collected. The fish fauna of the area was characterised by a diversity of small cyprinids (14 species), cichlids (9 species), clariid catfishes (4 species) and mormyrids (4 species). Species such as Clarias gariepinus, C. ngamensis, Marcusenius macrolepidotus, Tilapia rendali, T. sparrmanii and several small Barbus species were shared with adjacent floodplain systems such as the upper Zambezi and Kafue rivers. Fishing was undertaken by fishing groups consisting of a fisherman and his family, or a group of men fishing together. Access to the fishing grounds was controlled by traditional fishing leaders, who collected tribute from fishermen. Fishing groups utilised fixed, distinct fishing areas determined by ancestry. The most important time for fishing was during the drawdown phase of the floodplains, from March until June. During the dry season fewer groups were engaged in fishing, with many having returned to farming activities. The main fishing methods of the floodplain fishery were basket traps and mosquito-mesh funnel nets set into earth fish barriers (fish weirs) constructed on the plains, various mesh sizes of gillnets, hook longlines and seine nets. The use of fish spears, drag baskets and piscicides was of lesser importance. Most fishing gears were constructed of a variety of natural and modern, manufactured materials. The fishery was multi-species and 23 fish species were recorded from in catch. The three most important species in the catches were C. gariepinus, T. rendalli and M. macrolepidotus. Together these contributed 67% by weight to the catch. Catch-per-unit-effort (CPUE) for the different gears was 0.4 ± 0.3 kg.trap.night⁻¹ for basket traps, 2.7 ± 4.6 kg.net.night⁻¹ for funnel nets, 0.3 ± 0.5 kg.50 m net.night⁻¹ for gill nets, 3.5 ± 6.3 kg.100 hooks.night⁻¹ for longlines, 1.79 ± 1.11 kg.haul⁻¹ for mosquito-mesh seine nets and 6.87 ± 6.27 kg.haul⁻¹ for larger-mesh seine nets. The weight of average daily landings of fishing groups, using a variety of gears was 7.8 ± 7.4 kg. Fishermen were able to maintain the same catch rate between dry and wet seasons, with no significant differences (p < 0.05) in daily landings between seasons. Yield per fisherman for a seven month season, which required 2-3 relocations due to falling water level, was 1.64 t based on catch assessment, and 1.9 t from a socio-economic survey. A tentative yield per area estimate for the area was 2I7 kg.ha⁻¹ over the three month shallow-floodplain fishing season. Most fish landed in the fishery were processed into sundried or smoke-dried products. These were used for 1) home consumption, 2) trade with village farmers (from up to 70 km inland of the fishing grounds) in exchange for staple starch meal, and 3) sold to urban fish traders, reaching markets as distant as Lubumbashi in Democratic Republic of Congo. Fish traders toured fishing camps to buy fish, supporting auxiliary industries such as transport and accommodation services. The price for dried fish at source was 3.14 ± 1.34 USDlkg and the market price reported for the Zambian Copperbelt was 6.14 ± 2.54 USD/kg. Typical returns on investment in fish trading were estimated as 68-77%. The fishery was considered to be biologically and socially sustainable. By harvesting a seasonally transient assemblage of species with high productivity and biological turnover rates and with life histories adapted to high mortality, fishermen were able to maintain a stable and viable livelihood. Management recommendations for the area were that a fisheries management plan be developed that would seek to strengthen the traditional system of rights-allocation, address problems between fishing and tourism activities, and enhance communication between fisheries and conservation stakeholders. To do this it was recommended that: 1) conservation authorities recognise the importance of the fishery, 2) no changes to current effort levels and fishing methods were necessary, 3) points 1 and 2 above be used to improve communication and trust between conservation authorities and fishermen, 4) customary resource-access mechanisms be understood and strengthened so that local inhabitants' rights to the resource are protected, 5) fishermen help formulate and accept conservation and tourism rules, 6) tourists and guides be made aware of the function of the fishery, 7) a fisheries management forum of key community, government and conservation stakeholders be formed to shape and implement the fisheries management plan, 8) locally-adapted bylaws be created to legitimise crucial floodplain gears currently considered illegal (e.g. mosquito-net gears, fish weirs), 9) no intervention to formalise fish trading be made, and 10) a trained person with a fisheries background be hired oversee the implementation of the recommendations.
- Full Text:
- Authors: Huchzermeyer, Carl Friedrich
- Date: 2013
- Subjects: Bangweulu Swamps (Zambia) , Fisheries -- Zambia -- Bangweulu Swamps , Fishes -- Zambia -- Bangweulu Swamps , Fishery management -- Zambia -- Bangweulu Swamps , Fishing -- Zambia -- Bangweulu Swamps , Fishing -- Economic aspects -- Zambia -- Bangweulu Swamps , Fish stock assessment -- Zambia -- Bangweulu Swamps , Fish as food -- Zambia -- Bangweulu Swamps , Conservation of natural resources -- Zambia -- Bangweulu Swamps , Sustainable development -- Zambia -- Bangweulu Swamps
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5203 , http://hdl.handle.net/10962/d1003927 , Bangweulu Swamps (Zambia) , Fisheries -- Zambia -- Bangweulu Swamps , Fishes -- Zambia -- Bangweulu Swamps , Fishery management -- Zambia -- Bangweulu Swamps , Fishing -- Zambia -- Bangweulu Swamps , Fishing -- Economic aspects -- Zambia -- Bangweulu Swamps , Fish stock assessment -- Zambia -- Bangweulu Swamps , Fish as food -- Zambia -- Bangweulu Swamps , Conservation of natural resources -- Zambia -- Bangweulu Swamps , Sustainable development -- Zambia -- Bangweulu Swamps
- Description: Bangweulu Wetlands is a 6000 km² public-private-partnership conservation area in northeastern Zambia, lying on the south-eastern margins of the Bangweulu Swamps, Congo River system. The area is important for wildlife conservation, tourism and as a fishing ground for the local inhabitants. This study provides a baseline of the fish and fisheries of this area. The conservation area is situated on the transition zone between woodland, floodplain and swamp. A total of 42 fish species representing 12 taxonomic families were collected. The fish fauna of the area was characterised by a diversity of small cyprinids (14 species), cichlids (9 species), clariid catfishes (4 species) and mormyrids (4 species). Species such as Clarias gariepinus, C. ngamensis, Marcusenius macrolepidotus, Tilapia rendali, T. sparrmanii and several small Barbus species were shared with adjacent floodplain systems such as the upper Zambezi and Kafue rivers. Fishing was undertaken by fishing groups consisting of a fisherman and his family, or a group of men fishing together. Access to the fishing grounds was controlled by traditional fishing leaders, who collected tribute from fishermen. Fishing groups utilised fixed, distinct fishing areas determined by ancestry. The most important time for fishing was during the drawdown phase of the floodplains, from March until June. During the dry season fewer groups were engaged in fishing, with many having returned to farming activities. The main fishing methods of the floodplain fishery were basket traps and mosquito-mesh funnel nets set into earth fish barriers (fish weirs) constructed on the plains, various mesh sizes of gillnets, hook longlines and seine nets. The use of fish spears, drag baskets and piscicides was of lesser importance. Most fishing gears were constructed of a variety of natural and modern, manufactured materials. The fishery was multi-species and 23 fish species were recorded from in catch. The three most important species in the catches were C. gariepinus, T. rendalli and M. macrolepidotus. Together these contributed 67% by weight to the catch. Catch-per-unit-effort (CPUE) for the different gears was 0.4 ± 0.3 kg.trap.night⁻¹ for basket traps, 2.7 ± 4.6 kg.net.night⁻¹ for funnel nets, 0.3 ± 0.5 kg.50 m net.night⁻¹ for gill nets, 3.5 ± 6.3 kg.100 hooks.night⁻¹ for longlines, 1.79 ± 1.11 kg.haul⁻¹ for mosquito-mesh seine nets and 6.87 ± 6.27 kg.haul⁻¹ for larger-mesh seine nets. The weight of average daily landings of fishing groups, using a variety of gears was 7.8 ± 7.4 kg. Fishermen were able to maintain the same catch rate between dry and wet seasons, with no significant differences (p < 0.05) in daily landings between seasons. Yield per fisherman for a seven month season, which required 2-3 relocations due to falling water level, was 1.64 t based on catch assessment, and 1.9 t from a socio-economic survey. A tentative yield per area estimate for the area was 2I7 kg.ha⁻¹ over the three month shallow-floodplain fishing season. Most fish landed in the fishery were processed into sundried or smoke-dried products. These were used for 1) home consumption, 2) trade with village farmers (from up to 70 km inland of the fishing grounds) in exchange for staple starch meal, and 3) sold to urban fish traders, reaching markets as distant as Lubumbashi in Democratic Republic of Congo. Fish traders toured fishing camps to buy fish, supporting auxiliary industries such as transport and accommodation services. The price for dried fish at source was 3.14 ± 1.34 USDlkg and the market price reported for the Zambian Copperbelt was 6.14 ± 2.54 USD/kg. Typical returns on investment in fish trading were estimated as 68-77%. The fishery was considered to be biologically and socially sustainable. By harvesting a seasonally transient assemblage of species with high productivity and biological turnover rates and with life histories adapted to high mortality, fishermen were able to maintain a stable and viable livelihood. Management recommendations for the area were that a fisheries management plan be developed that would seek to strengthen the traditional system of rights-allocation, address problems between fishing and tourism activities, and enhance communication between fisheries and conservation stakeholders. To do this it was recommended that: 1) conservation authorities recognise the importance of the fishery, 2) no changes to current effort levels and fishing methods were necessary, 3) points 1 and 2 above be used to improve communication and trust between conservation authorities and fishermen, 4) customary resource-access mechanisms be understood and strengthened so that local inhabitants' rights to the resource are protected, 5) fishermen help formulate and accept conservation and tourism rules, 6) tourists and guides be made aware of the function of the fishery, 7) a fisheries management forum of key community, government and conservation stakeholders be formed to shape and implement the fisheries management plan, 8) locally-adapted bylaws be created to legitimise crucial floodplain gears currently considered illegal (e.g. mosquito-net gears, fish weirs), 9) no intervention to formalise fish trading be made, and 10) a trained person with a fisheries background be hired oversee the implementation of the recommendations.
- Full Text:
Fixed points of single-valued and multi-valued mappings with applications
- Authors: Stofile, Simfumene
- Date: 2013
- Subjects: Fixed point theory Mappings (Mathematics) Coincidence theory (Mathematics) Metric spaces Uniform spaces Set-valued maps
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5397 , http://hdl.handle.net/10962/d1002960
- Description: The relationship between the convergence of a sequence of self mappings of a metric space and their fixed points, known as the stability (or continuity) of fixed points has been of continuing interest and widely studied in fixed point theory. In this thesis we study the stability of common fixed points in a Hausdorff uniform space whose uniformity is generated by a family of pseudometrics, by using some general notations of convergence. These results are then extended to 2-metric spaces due to S. Gähler. In addition, a well-known theorem of T. Suzuki that generalized the Banach Contraction Principle is also extended to 2-metric spaces and applied to obtain a coincidence theorem for a pair of mappings on an arbitrary set with values in a 2-metric space. Further, we prove the existence of coincidence and fixed points of Ćirić type weakly generalized contractions in metric spaces. Subsequently, the above result is utilized to discuss applications to the convergence of modified Mann and Ishikawa iterations in a convex metric space. Finally, we obtain coincidence, fixed and stationary point results for multi-valued and hybrid pairs of mappings on a metric space.
- Full Text:
- Authors: Stofile, Simfumene
- Date: 2013
- Subjects: Fixed point theory Mappings (Mathematics) Coincidence theory (Mathematics) Metric spaces Uniform spaces Set-valued maps
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5397 , http://hdl.handle.net/10962/d1002960
- Description: The relationship between the convergence of a sequence of self mappings of a metric space and their fixed points, known as the stability (or continuity) of fixed points has been of continuing interest and widely studied in fixed point theory. In this thesis we study the stability of common fixed points in a Hausdorff uniform space whose uniformity is generated by a family of pseudometrics, by using some general notations of convergence. These results are then extended to 2-metric spaces due to S. Gähler. In addition, a well-known theorem of T. Suzuki that generalized the Banach Contraction Principle is also extended to 2-metric spaces and applied to obtain a coincidence theorem for a pair of mappings on an arbitrary set with values in a 2-metric space. Further, we prove the existence of coincidence and fixed points of Ćirić type weakly generalized contractions in metric spaces. Subsequently, the above result is utilized to discuss applications to the convergence of modified Mann and Ishikawa iterations in a convex metric space. Finally, we obtain coincidence, fixed and stationary point results for multi-valued and hybrid pairs of mappings on a metric space.
- Full Text:
Fluorescence behavior of glutathione capped CdTe@ ZnS quantum dots chemically coordinated to zinc octacarboxy phthalocyanines
- Sekhosana, Kutloano E, Antunes, Edith M, Khene, Samson M, D'Souza, Sarah, Nyokong, Tebello
- Authors: Sekhosana, Kutloano E , Antunes, Edith M , Khene, Samson M , D'Souza, Sarah , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242019 , vital:50993 , xlink:href="https://doi.org/10.1016/j.jlumin.2012.11.044"
- Description: Core–shell CdTe@ZnS quantum dots capped with glutathione (CdTe@ZnS–GSH) were covalently linked to zinc octacarboxy phthalocyanine (ZnPc(COOH)8). The conjugate was characterized by UV/Vis, infrared and X-Ray photoelectron spectroscopies as well as transmission electron and atomic force microscopies. The fluorescence quantum yields of the core CdTe capped with thioglycolic acid increased upon formation of the core-shell. Upon conjugation with ZnPc(COOH)8, the fluorescence quantum yield of CdTe@ZnS–GSH decreased due to energy transfer from the latter to the Pc. The average fluorescence lifetime of the CdTe@ZnS–GSH QD also decreased upon conjugation from 26.2 to 13.3 ns.
- Full Text:
- Authors: Sekhosana, Kutloano E , Antunes, Edith M , Khene, Samson M , D'Souza, Sarah , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242019 , vital:50993 , xlink:href="https://doi.org/10.1016/j.jlumin.2012.11.044"
- Description: Core–shell CdTe@ZnS quantum dots capped with glutathione (CdTe@ZnS–GSH) were covalently linked to zinc octacarboxy phthalocyanine (ZnPc(COOH)8). The conjugate was characterized by UV/Vis, infrared and X-Ray photoelectron spectroscopies as well as transmission electron and atomic force microscopies. The fluorescence quantum yields of the core CdTe capped with thioglycolic acid increased upon formation of the core-shell. Upon conjugation with ZnPc(COOH)8, the fluorescence quantum yield of CdTe@ZnS–GSH decreased due to energy transfer from the latter to the Pc. The average fluorescence lifetime of the CdTe@ZnS–GSH QD also decreased upon conjugation from 26.2 to 13.3 ns.
- Full Text:
Fluorescence “switch on” of conjugates of CdTe@ ZnS quantum dots with Al, Ni and Zn tetraamino-phthalocyanines by hydrogen peroxide
- Adegoke, Oluwasesan, Khene, Samson M, Nyokong, Tebello
- Authors: Adegoke, Oluwasesan , Khene, Samson M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241750 , vital:50966 , xlink:href="https://doi.org/10.1007/s10895-013-1222-x"
- Description: In this study, we have developed a novel nanoprobe for H2O2 based on the conjugation of CdTe@ZnS quantum dots (QDs) to different metal tetraamino-phthalocyanine (MTAPc): (M = (OAc)Al, {OAc = acetate}, Ni and Zn). Chemical coordination of the QDs to the MTAPc resulted in the fluorescence “switch off” of the linked QDs which was associated with Förster resonance energy transfer (FRET). In the presence of varying concentration of H2O2, the fluorescence of the linked QDs was progressively “switched on” and the FRET mechanism between the QDs and the MTAPc was disrupted. The sensitivity/limit of detection of the nanoprobe followed the order: QDs-ZnTAPc (2.2 μM) > QDs-NiTAPc (4.4 μM) > QDs-AlTAPc (9.8 μM) while the selectivity followed the order: QDs-NiTAPc > QDs-AlTAPc > QDs-ZnTAPc. The varying degree of sensitivity/selectivity and mechanism of detection is discussed in detail.
- Full Text:
- Authors: Adegoke, Oluwasesan , Khene, Samson M , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241750 , vital:50966 , xlink:href="https://doi.org/10.1007/s10895-013-1222-x"
- Description: In this study, we have developed a novel nanoprobe for H2O2 based on the conjugation of CdTe@ZnS quantum dots (QDs) to different metal tetraamino-phthalocyanine (MTAPc): (M = (OAc)Al, {OAc = acetate}, Ni and Zn). Chemical coordination of the QDs to the MTAPc resulted in the fluorescence “switch off” of the linked QDs which was associated with Förster resonance energy transfer (FRET). In the presence of varying concentration of H2O2, the fluorescence of the linked QDs was progressively “switched on” and the FRET mechanism between the QDs and the MTAPc was disrupted. The sensitivity/limit of detection of the nanoprobe followed the order: QDs-ZnTAPc (2.2 μM) > QDs-NiTAPc (4.4 μM) > QDs-AlTAPc (9.8 μM) while the selectivity followed the order: QDs-NiTAPc > QDs-AlTAPc > QDs-ZnTAPc. The varying degree of sensitivity/selectivity and mechanism of detection is discussed in detail.
- Full Text:
Fluorescence “turn on” probe for bromide ion using nanoconjugates of glutathione-capped CdTe@ ZnS quantum dots with nickel tetraamino-phthalocyanine
- Adegoke, Oluwasesan, Nyokong, Tebello
- Authors: Adegoke, Oluwasesan , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190479 , vital:44998 , xlink:href="https://doi.org/10.1016/j.jphotochem.2013.05.013"
- Description: In this paper, three differently sized glutathione (GSH)-capped CdTe@ZnS quantum dots (QDs) have been successfully conjugated to nickel tetraamino-phthalocyanine (NiTAPc) to form different QDs-NiTAPc nanocomplexes. Several techniques such as TEM, FT-IR, time-resolved fluorescence measurement and electronic spectroscopy were employed to characterize the nanocomplex. Bromide ion was chosen as a model anion to test the efficacy of the nanoprobe. The fluorescence of the nanoconjugate was “turned off” upon binding but was progressively “turned on” upon interaction with varying concentrations of bromide ion. Experimental results showed that the quantum size effect of nanocrystal QD determined the overall sensitivity and selectivity of the nanoprobe and followed the order QD563-NiTAPc > QD605-NiTAPc > QD621-NiTAPc. The mechanism of reaction is proposed.
- Full Text:
- Authors: Adegoke, Oluwasesan , Nyokong, Tebello
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190479 , vital:44998 , xlink:href="https://doi.org/10.1016/j.jphotochem.2013.05.013"
- Description: In this paper, three differently sized glutathione (GSH)-capped CdTe@ZnS quantum dots (QDs) have been successfully conjugated to nickel tetraamino-phthalocyanine (NiTAPc) to form different QDs-NiTAPc nanocomplexes. Several techniques such as TEM, FT-IR, time-resolved fluorescence measurement and electronic spectroscopy were employed to characterize the nanocomplex. Bromide ion was chosen as a model anion to test the efficacy of the nanoprobe. The fluorescence of the nanoconjugate was “turned off” upon binding but was progressively “turned on” upon interaction with varying concentrations of bromide ion. Experimental results showed that the quantum size effect of nanocrystal QD determined the overall sensitivity and selectivity of the nanoprobe and followed the order QD563-NiTAPc > QD605-NiTAPc > QD621-NiTAPc. The mechanism of reaction is proposed.
- Full Text:
For the people : an appraisal comparison of imagined communities in letters to two South African newspapers
- Authors: Smith, Jade
- Date: 2013
- Subjects: Daily Sun (Johannesburg, South Africa) , Times (Johannesburg, South Africa) , Mass media and social integration -- South Africa , Language and languages -- Usage , Mass media and language -- South Africa , Mass media and culture -- South Africa , Belonging (Social psychology)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2385 , http://hdl.handle.net/10962/d1016264
- Description: This thesis reports on the bonds that unify imagined communities (Anderson 1983) that are created in 40 letters prominently displayed on the opinions pages of the Daily Sun, a popular tabloid, and The Times, a daily offshoot of the mainstream national Sunday Times. An APPRAISAL analysis of these letters reveals how the imagined communities attempt to align their audiences around distinctive couplings of interpersonal and ideational meaning. Such couplings represent the bonds around which community identities are co-constructed through affiliation and are evidence of the shared feelings that unite the communities of readership. Inferences drawn from this APPRAISAL information allow for a comparison of the natures of the two communities in terms of how they view their agency and group cohesion. Central to the analysis and interpretation of the data is the letters’ evaluative prosody, traced in order to determine the polarity of readers’ stances over four weeks. Asymmetrical prosodies are construed as pointing to the validity of ‘linguistic ventriloquism’, a term whose definition is refined and used as a diagnostic for whether the newspapers use their readers’ letters to promote their own stances on controversial matters. Principal findings show that both communities affiliate around the value of education, and dissatisfaction with the country’s political leaders, however The Times’ readers are more individualistic than the Daily Sun’s community members, who are concerned with the wellbeing of the group. The analysis highlights limitations to the application of the APPRAISAL framework, the value of subjectivity in the analytical process, and adds a new dimension to South African media studies, as it provides linguistic insights into the construction of imagined communities of newspaper readership.
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- Authors: Smith, Jade
- Date: 2013
- Subjects: Daily Sun (Johannesburg, South Africa) , Times (Johannesburg, South Africa) , Mass media and social integration -- South Africa , Language and languages -- Usage , Mass media and language -- South Africa , Mass media and culture -- South Africa , Belonging (Social psychology)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2385 , http://hdl.handle.net/10962/d1016264
- Description: This thesis reports on the bonds that unify imagined communities (Anderson 1983) that are created in 40 letters prominently displayed on the opinions pages of the Daily Sun, a popular tabloid, and The Times, a daily offshoot of the mainstream national Sunday Times. An APPRAISAL analysis of these letters reveals how the imagined communities attempt to align their audiences around distinctive couplings of interpersonal and ideational meaning. Such couplings represent the bonds around which community identities are co-constructed through affiliation and are evidence of the shared feelings that unite the communities of readership. Inferences drawn from this APPRAISAL information allow for a comparison of the natures of the two communities in terms of how they view their agency and group cohesion. Central to the analysis and interpretation of the data is the letters’ evaluative prosody, traced in order to determine the polarity of readers’ stances over four weeks. Asymmetrical prosodies are construed as pointing to the validity of ‘linguistic ventriloquism’, a term whose definition is refined and used as a diagnostic for whether the newspapers use their readers’ letters to promote their own stances on controversial matters. Principal findings show that both communities affiliate around the value of education, and dissatisfaction with the country’s political leaders, however The Times’ readers are more individualistic than the Daily Sun’s community members, who are concerned with the wellbeing of the group. The analysis highlights limitations to the application of the APPRAISAL framework, the value of subjectivity in the analytical process, and adds a new dimension to South African media studies, as it provides linguistic insights into the construction of imagined communities of newspaper readership.
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Forced degradation studies of clobetasol 17‐propionate in methanol, propylene glycol, as bulk drug and cream formulations by RP‐HPLC
- Fauzee, Ayesha F B, Walker, Roderick B
- Authors: Fauzee, Ayesha F B , Walker, Roderick B
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184005 , vital:44154 , xlink:href="https://doi.org/10.1002/jssc.201200969"
- Description: A rapid, simple, stability-indicating forced degradation study of clobetasol 17-propionate was conducted using RP-HPLC. The method was used to analyze clobetasol 17-propionate in methanol, propylene glycol, and a cream formulation. Isocratic elution of clobetasol and its degradation products was achieved using a Nova-Pak® 4 μm C18 150 mm × 3.9 mm id cartridge column and a mobile phase of methanol: water (68:32 v/v) at a flow rate of 0.9 mL min−1. Quantitation was achieved with UV detection at 239 nm. Nondegraded clobetasol was eluted at a retention time of 6.0 min. Clobetasol 17-propionate was subjected to different stress conditions viz., acidic, basic, heat, oxidation, light, and neutral hydrolysis. The greatest degradation occurred under strong base and oxidative conditions. Strong base-degraded clobetasol produced additional peaks at retention times of 1.8, 4.0, 5.0, and 8.0 min and clobetasol oxidation degradation peaks eluted at 2.2 and 24 min. Complete validation was performed for linearity, accuracy, and precision over the concentration range 0.15–15 μg mL−1. All data were analyzed statistically and this RP-HPLC method proved to be accurate, precise, linear, and stability indicating for the quantitation of clobetasol 17-propionate in methanol, propylene glycol, and cream formulations.
- Full Text:
- Authors: Fauzee, Ayesha F B , Walker, Roderick B
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184005 , vital:44154 , xlink:href="https://doi.org/10.1002/jssc.201200969"
- Description: A rapid, simple, stability-indicating forced degradation study of clobetasol 17-propionate was conducted using RP-HPLC. The method was used to analyze clobetasol 17-propionate in methanol, propylene glycol, and a cream formulation. Isocratic elution of clobetasol and its degradation products was achieved using a Nova-Pak® 4 μm C18 150 mm × 3.9 mm id cartridge column and a mobile phase of methanol: water (68:32 v/v) at a flow rate of 0.9 mL min−1. Quantitation was achieved with UV detection at 239 nm. Nondegraded clobetasol was eluted at a retention time of 6.0 min. Clobetasol 17-propionate was subjected to different stress conditions viz., acidic, basic, heat, oxidation, light, and neutral hydrolysis. The greatest degradation occurred under strong base and oxidative conditions. Strong base-degraded clobetasol produced additional peaks at retention times of 1.8, 4.0, 5.0, and 8.0 min and clobetasol oxidation degradation peaks eluted at 2.2 and 24 min. Complete validation was performed for linearity, accuracy, and precision over the concentration range 0.15–15 μg mL−1. All data were analyzed statistically and this RP-HPLC method proved to be accurate, precise, linear, and stability indicating for the quantitation of clobetasol 17-propionate in methanol, propylene glycol, and cream formulations.
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Forensic Entomology: An introduction, D.E. Gennard: book review
- Authors: Villet, Martin H
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451721 , vital:75072 , https://hdl.handle.net/10520/EJC141290
- Description: Dorothy Gennard's role in the fourth-year course in Forensic Science at the University of Lincoln has placed her in an excellent position to design a text that caters for this level. It was generally agreed (e.g. Villet and Richards 2008; Higley and Huntington 2009) that the first edition of her book, published in 2007, was a useful text for teaching introductory courses in forensics, and this substantially revised edition is even better suited to that niche. Other recently revised texts are either difficult to acquire (Haskell and Williams, 2008) or more expensive reference works (Amendt et al. 2010; Byrd and Castner 2010).
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- Authors: Villet, Martin H
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451721 , vital:75072 , https://hdl.handle.net/10520/EJC141290
- Description: Dorothy Gennard's role in the fourth-year course in Forensic Science at the University of Lincoln has placed her in an excellent position to design a text that caters for this level. It was generally agreed (e.g. Villet and Richards 2008; Higley and Huntington 2009) that the first edition of her book, published in 2007, was a useful text for teaching introductory courses in forensics, and this substantially revised edition is even better suited to that niche. Other recently revised texts are either difficult to acquire (Haskell and Williams, 2008) or more expensive reference works (Amendt et al. 2010; Byrd and Castner 2010).
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Form over function? The practical application of the Recognition of Customary Marriages Act 1998 in South Africa
- Authors: Kruuse, Helen
- Date: 2013
- Language: English
- Type: Article , text
- Identifier: http://hdl.handle.net/10962/54094 , vital:26389 , http://journals.co.za/content/ju_jur/2013/1/EJC148455
- Description: The Recognition of Customary Marriages Act 120 of 1998 is a major legislative measure for the development of customary marriages in line with the constitutional principle of equality, specifically for women. The article explores the interactions between this ideal in the Act with empirical observations and the latest judicial decisions concerning its application. It considers various examples of the lack of protection of women in relationships of a customary nature, and it concludes that both the state and courts favour a formal or definitional approach to customary marriage. In considering alternative approaches that could adequately protect vulnerable parties, two conclusions emerge: First, the article recommends a wholesale revision of the South African family law approach from a focus on form to dependency. Second (and as a short-term measure), the article advocates for the putative marriage doctrine to be applied in the customary marriage context to protect many women who are denied access to 'customary marriage' as a form, and as a result, all of the benefits that flow from such marriage.
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- Authors: Kruuse, Helen
- Date: 2013
- Language: English
- Type: Article , text
- Identifier: http://hdl.handle.net/10962/54094 , vital:26389 , http://journals.co.za/content/ju_jur/2013/1/EJC148455
- Description: The Recognition of Customary Marriages Act 120 of 1998 is a major legislative measure for the development of customary marriages in line with the constitutional principle of equality, specifically for women. The article explores the interactions between this ideal in the Act with empirical observations and the latest judicial decisions concerning its application. It considers various examples of the lack of protection of women in relationships of a customary nature, and it concludes that both the state and courts favour a formal or definitional approach to customary marriage. In considering alternative approaches that could adequately protect vulnerable parties, two conclusions emerge: First, the article recommends a wholesale revision of the South African family law approach from a focus on form to dependency. Second (and as a short-term measure), the article advocates for the putative marriage doctrine to be applied in the customary marriage context to protect many women who are denied access to 'customary marriage' as a form, and as a result, all of the benefits that flow from such marriage.
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