Woody encroachment and plant-root soil interactions in a semi-arid savanna
- Authors: Gusha, Bukho
- Date: 2015
- Subjects: Pastures -- Management Weeds Invasive plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12053 , vital:39131
- Description: Savannas occupy 1/8 of the global land surface, support a large proportion of the world’s human population and the majority of its rangeland and livestock. Woody encroachment has been reported as the major challenge in these landscapes. This study describes the differences between three contrasting tree density classes in a semi- arid savanna with the view to developing an improved understanding of woody encroachment which is prevalent in this region. The study attempted to determine if there was a relationship between lateral root distributions at varying soil depths with increasing levels of woody encroachment, and to compare species composition and soil water profiles in these rangelands. Three homogeneous vegetation units, namely: sparsely encroached (HVU1), grassland (HVU2) and Albany thicket (HVU3) were identified for the study sites. A Trench method was used determine root biomass and a step point method was used to determine herbaceousspecies composition in all the HVUs. The results showed that more Decreaser species (especially Themeda triandra) were recorded in a sparsely encroached site (HVU1) and grassland site (HVU2), while Cynodon dactylon was mostly recorded in the thicket site (HVU3). Acacia karroo was mostly recorded in HVU1 while in HVU2 other woody species such as Coddia rudis and Grewia occidentalis were also recoded. HVU3 had the poorest basal cover (point to tuft distance) (22.60 cm) while HVU1 (9.93 cm) and HVU2 (7.73 cm) had moderate basal cover. The herbaceous standing biomass was significantly different across the HVUs. HVU3 was higher (1206.15 kg ha-1) than HVU1 (942.43 kg ha-1) and HVU2 (677.10 kg ha-1). The soil moisture content was significantly different between the HVUs, but was not significantly different between the depths (p< 0.05). High soil moisture content was recorded in HVU3 compared to other HVUs. The results of Analysis of Variance (ANOVA) showed that soil depth and the type of homogenous vegetation unit (HVU) had significant effects (p<0.01) on root biomass. The pair wise t-test showed that there were no significant difference in root biomass between sparsely encroached (HVU1) and grassland (HVU2) sites (p>0.05), but there were significant differences in root biomass between grassland (HVU2) and thicket (HVU3) site (p<0.05). The mean for total root biomass found in the study was 2.66 kg m-2. In all the trenches most of the root biomass was found in depth 1 (0-30 cm) which was 2.43 kg m-2followed by 1.32 kg m-2 in depth 2 (30-60 cm) and 0.49 kg m-2 in depth 3 (60-90 cm). According to the results on species composition, herbaceous biomass, basal cover, soil moisture content and the root biomass, Kwezana communal rangeland has a potential of running a sustainable livestock production enterprise if proper management practices can be implemented. To improve the rangelands of Kwezana communal rangelands management such as proper resting, burning, proper stocking rates and physically clearing of bushes should be considered.
- Full Text:
- Date Issued: 2015
- Authors: Gusha, Bukho
- Date: 2015
- Subjects: Pastures -- Management Weeds Invasive plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12053 , vital:39131
- Description: Savannas occupy 1/8 of the global land surface, support a large proportion of the world’s human population and the majority of its rangeland and livestock. Woody encroachment has been reported as the major challenge in these landscapes. This study describes the differences between three contrasting tree density classes in a semi- arid savanna with the view to developing an improved understanding of woody encroachment which is prevalent in this region. The study attempted to determine if there was a relationship between lateral root distributions at varying soil depths with increasing levels of woody encroachment, and to compare species composition and soil water profiles in these rangelands. Three homogeneous vegetation units, namely: sparsely encroached (HVU1), grassland (HVU2) and Albany thicket (HVU3) were identified for the study sites. A Trench method was used determine root biomass and a step point method was used to determine herbaceousspecies composition in all the HVUs. The results showed that more Decreaser species (especially Themeda triandra) were recorded in a sparsely encroached site (HVU1) and grassland site (HVU2), while Cynodon dactylon was mostly recorded in the thicket site (HVU3). Acacia karroo was mostly recorded in HVU1 while in HVU2 other woody species such as Coddia rudis and Grewia occidentalis were also recoded. HVU3 had the poorest basal cover (point to tuft distance) (22.60 cm) while HVU1 (9.93 cm) and HVU2 (7.73 cm) had moderate basal cover. The herbaceous standing biomass was significantly different across the HVUs. HVU3 was higher (1206.15 kg ha-1) than HVU1 (942.43 kg ha-1) and HVU2 (677.10 kg ha-1). The soil moisture content was significantly different between the HVUs, but was not significantly different between the depths (p< 0.05). High soil moisture content was recorded in HVU3 compared to other HVUs. The results of Analysis of Variance (ANOVA) showed that soil depth and the type of homogenous vegetation unit (HVU) had significant effects (p<0.01) on root biomass. The pair wise t-test showed that there were no significant difference in root biomass between sparsely encroached (HVU1) and grassland (HVU2) sites (p>0.05), but there were significant differences in root biomass between grassland (HVU2) and thicket (HVU3) site (p<0.05). The mean for total root biomass found in the study was 2.66 kg m-2. In all the trenches most of the root biomass was found in depth 1 (0-30 cm) which was 2.43 kg m-2followed by 1.32 kg m-2 in depth 2 (30-60 cm) and 0.49 kg m-2 in depth 3 (60-90 cm). According to the results on species composition, herbaceous biomass, basal cover, soil moisture content and the root biomass, Kwezana communal rangeland has a potential of running a sustainable livestock production enterprise if proper management practices can be implemented. To improve the rangelands of Kwezana communal rangelands management such as proper resting, burning, proper stocking rates and physically clearing of bushes should be considered.
- Full Text:
- Date Issued: 2015
Woody species composition and congregant appreciation of the cultural and spiritual services provided by cemeteries and church gardens in Grahamstown, South Africa
- Authors: De Lacy, Peter James Gerard
- Date: 2015
- Subjects: Plants -- Religious aspects , Cemeteries -- South Africa -- Grahamstown , Woody plants -- South Africa -- Grahamstown , Church gardens -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4783 , http://hdl.handle.net/10962/d1016401
- Description: Urbanization has increased rapidly throughout the world. The densification of urban areas has greatly reduced the number of natural areas occurring within the urban environment as well as impacting the ecosystem services that these areas provide. Urban greening and sustainable practices have been advocated as a means to once again provide the urban population with ecosystem services. Sacred natural areas that occur in surrounding forest, temple and cemetery sites have been known harbour a variety of biological diversity, as well as provide people with a number of cultural and spiritual benefits. Much of the literature on sacred natural sites comes from rural or eastern countries, leaving a large gap in the knowledge pertaining to information on these sites in both developed nations as well as urban areas. The aim of this study was to determine the abundance and composition of woody species, as well as the spiritual and cultural significance of sacred natural sites in Grahamstown. This study defined a sacred urban area as any form of garden surrounding a church, temple or mosque, as well as cemeteries. It looked at a total of 28 church gardens, one Hindu garden, one Mosque garden and five cemeteries in Grahamstown, South Africa. For each site the area was calculated and a tree and shrub inventory was done for all individuals above 1.5 m tall. Church/cemetery age, denomination and appearance were recorded as well as soil samples collected. An ordination of the data was done to summarize the community data, relating the community variation to environmental gradients. Questionnaires were completed by congregants who attended a religious building with a garden, as well as those that were not surrounded by a garden. These questionnaires were used to determine the cultural, spiritual and aesthetic value of trees and the sacred area, as well as the perceived and felt benefits that these areas provide. Those that were completed by congregants without gardens looked to find out whether or not it was believed that these areas would improve their experiences. There was an average plant density of 106.1 woody plants per hectare, with a total of 139 different species encountered. Of these, 56 percent were exotic species. This is slightly lower than that of studies done elsewhere in the world, but may be due to the omission of non-woody ornamentals and lawn species in this study. Of the top 11 most frequently occurring species, only two were indigenous. There was generally low similarity between plant assemblages found at the different sites. A significantly positive relationship was found between site size and woody plant basal area as well as the total number of woody plants. Site age and religious denomination had little influence on woody plant density, basal area, species richness or woody plant abundance. Congregants stated that a garden surrounding a religious building improved both their spiritual and aesthetic experiences. Stated spiritual and aesthetic experience was significantly influenced by basal area, while abundance significantly influenced stated aesthetic experience. Greenery was therefore important to many of the congregants, however, the species that were present were less influential. A greater sample size from a variety of religions and sacred areas within urban environments throughout the world would prove to be an interesting comparison for future research.
- Full Text:
- Date Issued: 2015
- Authors: De Lacy, Peter James Gerard
- Date: 2015
- Subjects: Plants -- Religious aspects , Cemeteries -- South Africa -- Grahamstown , Woody plants -- South Africa -- Grahamstown , Church gardens -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4783 , http://hdl.handle.net/10962/d1016401
- Description: Urbanization has increased rapidly throughout the world. The densification of urban areas has greatly reduced the number of natural areas occurring within the urban environment as well as impacting the ecosystem services that these areas provide. Urban greening and sustainable practices have been advocated as a means to once again provide the urban population with ecosystem services. Sacred natural areas that occur in surrounding forest, temple and cemetery sites have been known harbour a variety of biological diversity, as well as provide people with a number of cultural and spiritual benefits. Much of the literature on sacred natural sites comes from rural or eastern countries, leaving a large gap in the knowledge pertaining to information on these sites in both developed nations as well as urban areas. The aim of this study was to determine the abundance and composition of woody species, as well as the spiritual and cultural significance of sacred natural sites in Grahamstown. This study defined a sacred urban area as any form of garden surrounding a church, temple or mosque, as well as cemeteries. It looked at a total of 28 church gardens, one Hindu garden, one Mosque garden and five cemeteries in Grahamstown, South Africa. For each site the area was calculated and a tree and shrub inventory was done for all individuals above 1.5 m tall. Church/cemetery age, denomination and appearance were recorded as well as soil samples collected. An ordination of the data was done to summarize the community data, relating the community variation to environmental gradients. Questionnaires were completed by congregants who attended a religious building with a garden, as well as those that were not surrounded by a garden. These questionnaires were used to determine the cultural, spiritual and aesthetic value of trees and the sacred area, as well as the perceived and felt benefits that these areas provide. Those that were completed by congregants without gardens looked to find out whether or not it was believed that these areas would improve their experiences. There was an average plant density of 106.1 woody plants per hectare, with a total of 139 different species encountered. Of these, 56 percent were exotic species. This is slightly lower than that of studies done elsewhere in the world, but may be due to the omission of non-woody ornamentals and lawn species in this study. Of the top 11 most frequently occurring species, only two were indigenous. There was generally low similarity between plant assemblages found at the different sites. A significantly positive relationship was found between site size and woody plant basal area as well as the total number of woody plants. Site age and religious denomination had little influence on woody plant density, basal area, species richness or woody plant abundance. Congregants stated that a garden surrounding a religious building improved both their spiritual and aesthetic experiences. Stated spiritual and aesthetic experience was significantly influenced by basal area, while abundance significantly influenced stated aesthetic experience. Greenery was therefore important to many of the congregants, however, the species that were present were less influential. A greater sample size from a variety of religions and sacred areas within urban environments throughout the world would prove to be an interesting comparison for future research.
- Full Text:
- Date Issued: 2015
Working Towards Improved Facilitation of Research Capacity Development at Walter Sisulu University (WSU) Using Action Research (AR) Methodology
- Sotshangane, Nkosinathi Owen
- Authors: Sotshangane, Nkosinathi Owen
- Date: 2015
- Subjects: Capacity development -- Research Research -- Higher education Research development -- Study and teaching -- South Africa Education, higher -- Action Research -- South Africa
- Language: English
- Type: Thesis , Doctoral , D Ed
- Identifier: http://hdl.handle.net/11260/901 , vital:30009
- Description: This study was originally undertaken to change and improve the way I do my practice at Walter Sisulu University as a Research Associate whose responsibility is to facilitate research capacity development and research excellence within the University, amongst academics and postgraduate students. The success of the Research Resource Centre that I manage depends on the way I promote research culture and research productivity amongst academics and postgraduate students. According to Leedy and Ormrod (2013, p. 2), research is a systematic process that is used to collect, analyse, and interpret data in order to increase my understanding of the phenomenon about interest and concern about a given/identified phenomenon. In this case my own practice changed and improved for the better. The main objective of this study, therefore, was to examine the reasons behind the decline in research productivity in terms of research output and how this could be reversed through action research study intervention in order to enhance research productivity at Walter Sisulu University (WSU). The Department of Higher Education and Training’s (DHET) allocation of research output units for WSU indicated that there was a decline in research output from 2005 to 2010. The extent to which my practice improvement could contribute towards changing or improving research productivity was a question which this study addressed through a quantitative, qualitative and self-reflective action research cyclic inquiry. I organized sample strategies of this study as follows: For quantitative data, I used 120 lecturers as my respondents through questionnaires (females = 47 and males = 73) who were randomly selected; For qualitative data, I used 24 lecturers as respondents who were randomly selected with whom I conducted interviews; and For self-reflective action research cyclic inquiry I used 7 Transformative Education/al Studies (TES) project group members as my focus group. My research findings concluded that the heavy teaching workload at WSU was problematic and lecturers/academics could not devote time to do research. My recommendation is that research should be made compulsory so that academics become aware that at least one or two published articles are required from them, for the benefit of annual university research productivity. Some research participants also recommended that the Research Resource Centre must include programs that focus directly on active participation in research in order to increase the capacity of individual researchers so as to build a critical mass of competent researchers, perhaps by even including incentives as a reward for doing research. According to Koshy (2010), action research is a specific method of conducting research by professionals and practitioners with the ultimate aim of improving practice. My new knowledge, therefore, in respect of how a concerned Research Associate, from a Historically Disadvantaged Institution (HDI), provided the impetus to create a collaborative practice in a higher education institution which was forced to merge with two former technikons (which lacked understanding of what a university means by research productivity and research output). I consequently developed the Nkosinathi Sotshangane’s cyclic practice improvement model through self-reflective action research, from which I believed other research practitioners could learn by doing something similar in their own context.
- Full Text:
- Date Issued: 2015
- Authors: Sotshangane, Nkosinathi Owen
- Date: 2015
- Subjects: Capacity development -- Research Research -- Higher education Research development -- Study and teaching -- South Africa Education, higher -- Action Research -- South Africa
- Language: English
- Type: Thesis , Doctoral , D Ed
- Identifier: http://hdl.handle.net/11260/901 , vital:30009
- Description: This study was originally undertaken to change and improve the way I do my practice at Walter Sisulu University as a Research Associate whose responsibility is to facilitate research capacity development and research excellence within the University, amongst academics and postgraduate students. The success of the Research Resource Centre that I manage depends on the way I promote research culture and research productivity amongst academics and postgraduate students. According to Leedy and Ormrod (2013, p. 2), research is a systematic process that is used to collect, analyse, and interpret data in order to increase my understanding of the phenomenon about interest and concern about a given/identified phenomenon. In this case my own practice changed and improved for the better. The main objective of this study, therefore, was to examine the reasons behind the decline in research productivity in terms of research output and how this could be reversed through action research study intervention in order to enhance research productivity at Walter Sisulu University (WSU). The Department of Higher Education and Training’s (DHET) allocation of research output units for WSU indicated that there was a decline in research output from 2005 to 2010. The extent to which my practice improvement could contribute towards changing or improving research productivity was a question which this study addressed through a quantitative, qualitative and self-reflective action research cyclic inquiry. I organized sample strategies of this study as follows: For quantitative data, I used 120 lecturers as my respondents through questionnaires (females = 47 and males = 73) who were randomly selected; For qualitative data, I used 24 lecturers as respondents who were randomly selected with whom I conducted interviews; and For self-reflective action research cyclic inquiry I used 7 Transformative Education/al Studies (TES) project group members as my focus group. My research findings concluded that the heavy teaching workload at WSU was problematic and lecturers/academics could not devote time to do research. My recommendation is that research should be made compulsory so that academics become aware that at least one or two published articles are required from them, for the benefit of annual university research productivity. Some research participants also recommended that the Research Resource Centre must include programs that focus directly on active participation in research in order to increase the capacity of individual researchers so as to build a critical mass of competent researchers, perhaps by even including incentives as a reward for doing research. According to Koshy (2010), action research is a specific method of conducting research by professionals and practitioners with the ultimate aim of improving practice. My new knowledge, therefore, in respect of how a concerned Research Associate, from a Historically Disadvantaged Institution (HDI), provided the impetus to create a collaborative practice in a higher education institution which was forced to merge with two former technikons (which lacked understanding of what a university means by research productivity and research output). I consequently developed the Nkosinathi Sotshangane’s cyclic practice improvement model through self-reflective action research, from which I believed other research practitioners could learn by doing something similar in their own context.
- Full Text:
- Date Issued: 2015
Working with critical realist perspective and tools at the interface of indigenous and scientific knowledge in a science curriculum setting
- Authors: O'Donoghue, Rob B
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/437081 , vital:73329 , ISBN 9781315660899 , https://www.routledge.com/Critical-Realism-Environmental-Learning-and-Social-Ecological-Change/Price-Lotz-Sistka/p/book/9780367597689
- Description: This chapter uses basic and dialectical critical realism to exam-ine and review prevailing dispositions on indigenous and insti-tutional knowledge (Western science) in environmental educa-tion processes. It examines some of the macro social pro-cesses that have inscribed assumptions of incommensurable differences between the two kinds of knowledge. It notes that whereas a previous hegemony of positivism would have re-sulted in the dismissal of much indigenous knowledge as mere superstition, contemporary intellectual perspectives (poststruc-tural and hermeneutical) have shaped a proliferation of worldview modelling that has resulted in a macro-level exempli-fying of indigenous knowledge as different and opposing Western science. Here, the lack of adequate mediating tools has given rise to a problematic inscription of assumed differ-ence between the knowledge of indigenous peoples and that of scientific institutions. Furthermore, despite an overt emancipatory intention in worldview discourses, the marginalization of indigenous peoples and knowledge remains.
- Full Text:
- Date Issued: 2015
- Authors: O'Donoghue, Rob B
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/437081 , vital:73329 , ISBN 9781315660899 , https://www.routledge.com/Critical-Realism-Environmental-Learning-and-Social-Ecological-Change/Price-Lotz-Sistka/p/book/9780367597689
- Description: This chapter uses basic and dialectical critical realism to exam-ine and review prevailing dispositions on indigenous and insti-tutional knowledge (Western science) in environmental educa-tion processes. It examines some of the macro social pro-cesses that have inscribed assumptions of incommensurable differences between the two kinds of knowledge. It notes that whereas a previous hegemony of positivism would have re-sulted in the dismissal of much indigenous knowledge as mere superstition, contemporary intellectual perspectives (poststruc-tural and hermeneutical) have shaped a proliferation of worldview modelling that has resulted in a macro-level exempli-fying of indigenous knowledge as different and opposing Western science. Here, the lack of adequate mediating tools has given rise to a problematic inscription of assumed differ-ence between the knowledge of indigenous peoples and that of scientific institutions. Furthermore, despite an overt emancipatory intention in worldview discourses, the marginalization of indigenous peoples and knowledge remains.
- Full Text:
- Date Issued: 2015
Young people’s use of ‘peer pressure/normalization’ as discursive resources to justify gendered youth sexualities: implications for Life Orientation sexuality education programmes
- Jearey-Graham, Nicola, Macleod, Catriona I
- Authors: Jearey-Graham, Nicola , Macleod, Catriona I
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143749 , vital:38279 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: ‘Peer pressure’ has been associated in the scientific literature with a range of risky sexual behaviors, thereby undermining safe sex messages delivered in Life Orientation (LO) classes. LO texts warn against peer pressure. Taking a discursive psychology perspective, we show how young people, in contrast, use the discourses of ‘peer pressure to have sex’ and ‘peer normalization of sex’ to justify youth sexual activity. Using data from focus group discussions about youth sexualities with students at a Further Education and Training College in South Africa, we show how participants outlined a need for young people to be socially recognizable through engaging in, and being able to talk about sex, and how they implicated peer norms in governing individual sexual behavior. Both discourses pointed to a gendering of sexual norms. The deployment of these discourses by young people themselves has implications for Life Orientation programmes. Nuanced engagement with ‘peer group’ narratives is indicated.
- Full Text:
- Date Issued: 2015
- Authors: Jearey-Graham, Nicola , Macleod, Catriona I
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143749 , vital:38279 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: ‘Peer pressure’ has been associated in the scientific literature with a range of risky sexual behaviors, thereby undermining safe sex messages delivered in Life Orientation (LO) classes. LO texts warn against peer pressure. Taking a discursive psychology perspective, we show how young people, in contrast, use the discourses of ‘peer pressure to have sex’ and ‘peer normalization of sex’ to justify youth sexual activity. Using data from focus group discussions about youth sexualities with students at a Further Education and Training College in South Africa, we show how participants outlined a need for young people to be socially recognizable through engaging in, and being able to talk about sex, and how they implicated peer norms in governing individual sexual behavior. Both discourses pointed to a gendering of sexual norms. The deployment of these discourses by young people themselves has implications for Life Orientation programmes. Nuanced engagement with ‘peer group’ narratives is indicated.
- Full Text:
- Date Issued: 2015
‘Charmer boys’ and ‘cream girls’: children’s construction of the (hetero)sexual self through football and implications for Life Orientation sexuality education
- Authors: Mayeza, Emmanuel
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143760 , vital:38280 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: Due to the adult-centric ‘common-sense’ view of primary school children as non-sexual, research on schooling, gender and sexuality in South Africa rarely addresses primary schools. In contrast, this paper explores how nine-to-ten year-old children in a working-class, township primary school near Durban (hetero)sexualise their gendered identities through football. By illuminating the different ways in which the young children in the study construct themselves as both gendered and sexual beings in their everyday playground and sometimes ‘underground’ cultures at the school, the paper calls into question the ‘common-sense’ discourse of childhood which (re)produces primary schools as sexuallyfree contexts. Findings raise pertinent implications that call for the (re)conceptualisation of children; from being seen simply through the discourse of sexual innocence to being conceptualised as people who are capable of expressing sexual agency. This, in turn, calls for the development of new ways of working with the young children in Life Orientation sexuality and HIV/AIDS education which are empathetic and sympathetic to the children’s own constructions of themselves as both gendered and sexual beings.
- Full Text:
- Date Issued: 2015
- Authors: Mayeza, Emmanuel
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143760 , vital:38280 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: Due to the adult-centric ‘common-sense’ view of primary school children as non-sexual, research on schooling, gender and sexuality in South Africa rarely addresses primary schools. In contrast, this paper explores how nine-to-ten year-old children in a working-class, township primary school near Durban (hetero)sexualise their gendered identities through football. By illuminating the different ways in which the young children in the study construct themselves as both gendered and sexual beings in their everyday playground and sometimes ‘underground’ cultures at the school, the paper calls into question the ‘common-sense’ discourse of childhood which (re)produces primary schools as sexuallyfree contexts. Findings raise pertinent implications that call for the (re)conceptualisation of children; from being seen simply through the discourse of sexual innocence to being conceptualised as people who are capable of expressing sexual agency. This, in turn, calls for the development of new ways of working with the young children in Life Orientation sexuality and HIV/AIDS education which are empathetic and sympathetic to the children’s own constructions of themselves as both gendered and sexual beings.
- Full Text:
- Date Issued: 2015
‘It's just taking our souls back’: discourses of apartheid and race
- Authors: Bock, Zannie , Hunt, Sally
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124888 , vital:35707 , https://doi.org/10.2989/16073614.2015.1056196
- Description: Although apartheid officially ended in 1994, the issue of race as a primary identity marker has continued to permeate many aspects of private and public life in post-apartheid South Africa. This paper seeks to understand how youth at two South African tertiary institutions position themselves in relation to race and the apartheid past. Our data include four focus group interviews from two universities, one which can be described as historically ‘black’ and the other as historically ‘white’. Given the complex nature of the data, we elected to use a combination of corpus linguistics and discourse analysis as our methodological approach. We explore how words such as black, white, coloured, they, we, us and them feature in the interviews. Our analysis shows that the positioning by the interviewees reflects a complexity and ambivalence that is at times contradictory although several broader discourse patterns can be distilled. In particular, we argue, that all groups employ a range of discursive strategies so as to resist being positioned in the historical positions of ‘victim’ and ‘perpetrator’. Our paper reflects on these findings as well as what they offer us as we attempt to chart new discourses of the future.
- Full Text:
- Date Issued: 2015
- Authors: Bock, Zannie , Hunt, Sally
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124888 , vital:35707 , https://doi.org/10.2989/16073614.2015.1056196
- Description: Although apartheid officially ended in 1994, the issue of race as a primary identity marker has continued to permeate many aspects of private and public life in post-apartheid South Africa. This paper seeks to understand how youth at two South African tertiary institutions position themselves in relation to race and the apartheid past. Our data include four focus group interviews from two universities, one which can be described as historically ‘black’ and the other as historically ‘white’. Given the complex nature of the data, we elected to use a combination of corpus linguistics and discourse analysis as our methodological approach. We explore how words such as black, white, coloured, they, we, us and them feature in the interviews. Our analysis shows that the positioning by the interviewees reflects a complexity and ambivalence that is at times contradictory although several broader discourse patterns can be distilled. In particular, we argue, that all groups employ a range of discursive strategies so as to resist being positioned in the historical positions of ‘victim’ and ‘perpetrator’. Our paper reflects on these findings as well as what they offer us as we attempt to chart new discourses of the future.
- Full Text:
- Date Issued: 2015
‘Victim’ or ‘survivor’?: language, identity and ethics revisited
- Barker, Kim, Macleod, Catriona I
- Authors: Barker, Kim , Macleod, Catriona I
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143738 , vital:38278 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: Initially in feminist circles, and subsequently in more common usage, the term ‘survivor’ came to signify those who have been (sexually) violated and live on, and even thrive. The passivity implied by the term ‘victim’ therefore gave way to the more agentic connotations of ‘survivor’. However, neither term adequately captures the complexity and fluidity of subject positions taken up by and ascribed to women who have been subjected to sexual violence. The selection of an inadequate word is not neutral: each identifier calls forth particular identity constructions which have real effects. Reducing women’s experiences to one pole of this simple binary can diminish and totalise those experiences. In this paper we re-consider the use of these terms with reference to research conducted with protestors participating in an annual anti-rape protest held at Rhodes University, Grahamstown, South Africa. We focus on the perspectives of women who are ‘survivors’ of sexual violence.
- Full Text:
- Date Issued: 2015
- Authors: Barker, Kim , Macleod, Catriona I
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143738 , vital:38278 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: Initially in feminist circles, and subsequently in more common usage, the term ‘survivor’ came to signify those who have been (sexually) violated and live on, and even thrive. The passivity implied by the term ‘victim’ therefore gave way to the more agentic connotations of ‘survivor’. However, neither term adequately captures the complexity and fluidity of subject positions taken up by and ascribed to women who have been subjected to sexual violence. The selection of an inadequate word is not neutral: each identifier calls forth particular identity constructions which have real effects. Reducing women’s experiences to one pole of this simple binary can diminish and totalise those experiences. In this paper we re-consider the use of these terms with reference to research conducted with protestors participating in an annual anti-rape protest held at Rhodes University, Grahamstown, South Africa. We focus on the perspectives of women who are ‘survivors’ of sexual violence.
- Full Text:
- Date Issued: 2015
‘… a huge monster that should be feared and not done’: lessons learned in sexuality education classes in South Africa
- Shefer, Tamara, Kruger, Lou-Marie, Macleod, Catriona I, Baxen, Jean, Vincent, Louise
- Authors: Shefer, Tamara , Kruger, Lou-Marie , Macleod, Catriona I , Baxen, Jean , Vincent, Louise
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6314 , http://hdl.handle.net/10962/d1020933 , http://www.mrc.ac.za/crime/aspj/2015/AhugeMonster.pdf
- Description: Research has foregrounded the way in which heterosexual practices for many young people are not infrequently bound up with violence and unequal transactional power relations. The Life Orientation sexuality education curriculum in South African schools has been viewed as a potentially valuable space to work with young people on issues of reproductive health, gender and sexual norms and relations. Yet, research has illustrated that such work may not only be failing to impact on more equitable sexual practices between young men and women, but may also serve to reproduce the very discourses and practices that the work aims to challenge. Cultures of violence in youth sexuality are closely connected to prevailing gender norms and practices which, for example, render women as passive victims who are incapable of exercising sexual agency and men as inherently sexually predatory. This paper analyses the talk of Grade 10 learners in nine diverse schools in two South African provinces, the Eastern Cape and the Western Cape, to highlight what ‘lessons’ these young people seem to be learning about sexuality in Life Orientation classes. We find that these lessons foreground cautionary, negative and punitive messages, which reinforce, rather than challenge, normative gender roles. ‘Scare’ messages of danger, damage and disease give rise to presumptions of gendered responsibility for risk and the requirement of female restraint in the face of the assertion of masculine desire and predation. We conclude that the role which sexuality education could play in enabling young women in particular to more successfully negotiate their sexual relationships to serve their own needs, reproductive health and safety, is undermined by regulatory messages directed at controlling young people, and young women in particular – and that instead, young people’s sexual agency has to be acknowledged in any processes of change aimed at gender equality, anti-violence, health and well-being.
- Full Text:
- Date Issued: 2015
- Authors: Shefer, Tamara , Kruger, Lou-Marie , Macleod, Catriona I , Baxen, Jean , Vincent, Louise
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6314 , http://hdl.handle.net/10962/d1020933 , http://www.mrc.ac.za/crime/aspj/2015/AhugeMonster.pdf
- Description: Research has foregrounded the way in which heterosexual practices for many young people are not infrequently bound up with violence and unequal transactional power relations. The Life Orientation sexuality education curriculum in South African schools has been viewed as a potentially valuable space to work with young people on issues of reproductive health, gender and sexual norms and relations. Yet, research has illustrated that such work may not only be failing to impact on more equitable sexual practices between young men and women, but may also serve to reproduce the very discourses and practices that the work aims to challenge. Cultures of violence in youth sexuality are closely connected to prevailing gender norms and practices which, for example, render women as passive victims who are incapable of exercising sexual agency and men as inherently sexually predatory. This paper analyses the talk of Grade 10 learners in nine diverse schools in two South African provinces, the Eastern Cape and the Western Cape, to highlight what ‘lessons’ these young people seem to be learning about sexuality in Life Orientation classes. We find that these lessons foreground cautionary, negative and punitive messages, which reinforce, rather than challenge, normative gender roles. ‘Scare’ messages of danger, damage and disease give rise to presumptions of gendered responsibility for risk and the requirement of female restraint in the face of the assertion of masculine desire and predation. We conclude that the role which sexuality education could play in enabling young women in particular to more successfully negotiate their sexual relationships to serve their own needs, reproductive health and safety, is undermined by regulatory messages directed at controlling young people, and young women in particular – and that instead, young people’s sexual agency has to be acknowledged in any processes of change aimed at gender equality, anti-violence, health and well-being.
- Full Text:
- Date Issued: 2015
“Bold Distinguished You”: a critical discourse analysis of the representation of masculinity in Destiny Man, 2012 - 2013
- Authors: Hutcheson, Lauren
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/56032 , vital:26767
- Description: Radical social and economic changes have transformed the employment opportunities available to black men in South Africa, and consumer magazines like Destiny Man have been quick to respond. Historical shifts in the configuration of an ideal black masculinity have been proposed over time in magazine representations of black men. Critiques of the representations of black men in consumer magazines pre- and post- independence interrogate the politics of the ways in which black masculinity has been, and is, configured around classed identities. In this study, I present the findings of a critical discourse analysis (CDA) on the construction and representation of masculinity within a contemporary South African’s men’s lifestyle magazine, Destiny Man. This study presents an analysis of the subject positions that this magazine constructs for its male readers. Destiny Man proposes particular kinds of discursive subjects in its sets of representations, both in word and image. The images and copy validate a neo-liberal elite masculinity achieved through self-surveillance and a variety of technologies of self, with the ultimate focus on material success. I argue that these representations have implications for the development of masculinities in a context marked by extreme inequality.
- Full Text:
- Date Issued: 2015
- Authors: Hutcheson, Lauren
- Date: 2015
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/56032 , vital:26767
- Description: Radical social and economic changes have transformed the employment opportunities available to black men in South Africa, and consumer magazines like Destiny Man have been quick to respond. Historical shifts in the configuration of an ideal black masculinity have been proposed over time in magazine representations of black men. Critiques of the representations of black men in consumer magazines pre- and post- independence interrogate the politics of the ways in which black masculinity has been, and is, configured around classed identities. In this study, I present the findings of a critical discourse analysis (CDA) on the construction and representation of masculinity within a contemporary South African’s men’s lifestyle magazine, Destiny Man. This study presents an analysis of the subject positions that this magazine constructs for its male readers. Destiny Man proposes particular kinds of discursive subjects in its sets of representations, both in word and image. The images and copy validate a neo-liberal elite masculinity achieved through self-surveillance and a variety of technologies of self, with the ultimate focus on material success. I argue that these representations have implications for the development of masculinities in a context marked by extreme inequality.
- Full Text:
- Date Issued: 2015
“Ha! Relationships? I only shout at them!”: Strategic management of discordant rapport in an African small business context
- Lauriks, Sanne, Siebörger, Ian, De Vos, Mark A
- Authors: Lauriks, Sanne , Siebörger, Ian , De Vos, Mark A
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/385338 , vital:68009 , xlink:href="https://doi.org/10.1515/pr-2015-0002"
- Description: This study demonstrates how and why interactants at a tyre fitment centre in Grahamstown, South Africa, manage discordant interpersonal relationships in strategic ways. Individuals in a post-apartheid small business respond to their social and economic context and exercise agency to their advantage in doing so. This study draws on linguistic ethnography (Rampton 2007) and the Rapport Management Framework (RMF, Spencer-Oatey 2000b, 2011), itself a development of politeness theory (Brown and Levinson 1987). An initial RMF analysis ran into difficulties around interactions that at first glance appeared to be oriented toward Rapport Challenge and Neglect. Upon closer examination, it appeared that discordant rapport was being actively maintained in this business. This led us to address underdeveloped areas of RMF that were not responsive enough to describe naturally occurring small business interactions, and propose an Enhanced Rapport Management Framework to overcome its inadequacies. We conclude that people may deliberately maintain discordant relationships when it is in their best interests to do so. Thus, contrary to a common-sense belief that harmonious social relations are an intrinsic good, we found that promoting discordant social relations can be understood as a rational response to individuals’ social and economic contexts, particularly in conditions such as those in many postcolonial African societies.
- Full Text:
- Date Issued: 2015
- Authors: Lauriks, Sanne , Siebörger, Ian , De Vos, Mark A
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/385338 , vital:68009 , xlink:href="https://doi.org/10.1515/pr-2015-0002"
- Description: This study demonstrates how and why interactants at a tyre fitment centre in Grahamstown, South Africa, manage discordant interpersonal relationships in strategic ways. Individuals in a post-apartheid small business respond to their social and economic context and exercise agency to their advantage in doing so. This study draws on linguistic ethnography (Rampton 2007) and the Rapport Management Framework (RMF, Spencer-Oatey 2000b, 2011), itself a development of politeness theory (Brown and Levinson 1987). An initial RMF analysis ran into difficulties around interactions that at first glance appeared to be oriented toward Rapport Challenge and Neglect. Upon closer examination, it appeared that discordant rapport was being actively maintained in this business. This led us to address underdeveloped areas of RMF that were not responsive enough to describe naturally occurring small business interactions, and propose an Enhanced Rapport Management Framework to overcome its inadequacies. We conclude that people may deliberately maintain discordant relationships when it is in their best interests to do so. Thus, contrary to a common-sense belief that harmonious social relations are an intrinsic good, we found that promoting discordant social relations can be understood as a rational response to individuals’ social and economic contexts, particularly in conditions such as those in many postcolonial African societies.
- Full Text:
- Date Issued: 2015
“Mother of the Nation”: representations of womanhood in South African media
- Authors: Hunt, Sally
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/139229 , vital:37717 , ISBN 9789027206565 , https://benjamins.com/catalog/dapsac.65
- Description: The discourses of the post-apartheid South Africa embody symbols of change and promises of new lessons in history. This is the first volume that brings together analyses of a variety of discourses produced in South Africa through which we follow the evolution of transitional processes in the country’s political institutions and in the opinions of its populace. The book offers to the reader a visit to the Parliament, a peek into the internet forums, analyses of the country's official papers and speeches, and the media accounts. Through all these discourses we see the burning questions – "Who Are We Now?" and "Who Do We Want To Be?" – being repetitively examined and identities cross-formed while the country deals with new, post-apartheid challenges, as well as successes.
- Full Text:
- Date Issued: 2015
- Authors: Hunt, Sally
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/139229 , vital:37717 , ISBN 9789027206565 , https://benjamins.com/catalog/dapsac.65
- Description: The discourses of the post-apartheid South Africa embody symbols of change and promises of new lessons in history. This is the first volume that brings together analyses of a variety of discourses produced in South Africa through which we follow the evolution of transitional processes in the country’s political institutions and in the opinions of its populace. The book offers to the reader a visit to the Parliament, a peek into the internet forums, analyses of the country's official papers and speeches, and the media accounts. Through all these discourses we see the burning questions – "Who Are We Now?" and "Who Do We Want To Be?" – being repetitively examined and identities cross-formed while the country deals with new, post-apartheid challenges, as well as successes.
- Full Text:
- Date Issued: 2015
“Peer pressure” and “Peer normalization” : discursive resources that justify gendered youth sexualities
- Macleod, Catriona I, Jearey-Graham, Nicola
- Authors: Macleod, Catriona I , Jearey-Graham, Nicola
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6312 , http://hdl.handle.net/10962/d1019877 , https://link.springer.com/article/10.1007/s13178-015-0207-8
- Description: “Peer pressure” is associated in the scientific literature with a range of risky sexual behaviors and with undermining public sexual health messages. Interventions are instituted encouraging young people to resist peer pressure or to model positive peer norms. Taking a discursive psychology perspective, we show how young people themselves use the discourses of “peer pressure to have sex” and “peer normalization of sex” to explain and justify youth sexual activity. Using data from focus group discussions about youth sexualities with students at a South African further education and training college, we show how participants outlined a need for young people to be socially recognizable through engaging in, and talking about, sex and how they implicated peer norms in governing individual sexual behavior. Both discourses pointed to a gendering of peer-endorsed sexual norms: masculine virility, the avoidance of shameful virgin or gay positions, and multiple sexual partners were emphasized for men, while the necessity of keeping a boyfriend and avoiding a “slut” position were foregrounded for women. These discourses potentially undermine the aims of public sexual health programs targeting youth. Nuanced engagement with peer group narratives, especially how sexual activity is explained and justified in a gendered fashion, is indicated. , Full text access on Publisher website: https://link.springer.com/article/10.1007/s13178-015-0207-8
- Full Text: false
- Date Issued: 2015
- Authors: Macleod, Catriona I , Jearey-Graham, Nicola
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6312 , http://hdl.handle.net/10962/d1019877 , https://link.springer.com/article/10.1007/s13178-015-0207-8
- Description: “Peer pressure” is associated in the scientific literature with a range of risky sexual behaviors and with undermining public sexual health messages. Interventions are instituted encouraging young people to resist peer pressure or to model positive peer norms. Taking a discursive psychology perspective, we show how young people themselves use the discourses of “peer pressure to have sex” and “peer normalization of sex” to explain and justify youth sexual activity. Using data from focus group discussions about youth sexualities with students at a South African further education and training college, we show how participants outlined a need for young people to be socially recognizable through engaging in, and talking about, sex and how they implicated peer norms in governing individual sexual behavior. Both discourses pointed to a gendering of peer-endorsed sexual norms: masculine virility, the avoidance of shameful virgin or gay positions, and multiple sexual partners were emphasized for men, while the necessity of keeping a boyfriend and avoiding a “slut” position were foregrounded for women. These discourses potentially undermine the aims of public sexual health programs targeting youth. Nuanced engagement with peer group narratives, especially how sexual activity is explained and justified in a gendered fashion, is indicated. , Full text access on Publisher website: https://link.springer.com/article/10.1007/s13178-015-0207-8
- Full Text: false
- Date Issued: 2015
A high-level architecture for efficient packet trace analysis on gpu co-processors
- Nottingham, Alastair, Irwin, Barry V W
- Authors: Nottingham, Alastair , Irwin, Barry V W
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429572 , vital:72623 , 10.1109/ISSA.2013.6641052
- Description: This paper proposes a high-level architecture to support efficient, massively parallel packet classification, filtering and analysis using commodity Graphics Processing Unit (GPU) hardware. The proposed architecture aims to provide a flexible and efficient parallel packet processing and analysis framework, supporting complex programmable filtering, data mining operations, statistical analysis functions and traffic visualisation, with minimal CPU overhead. In particular, this framework aims to provide a robust set of high-speed analysis functionality, in order to dramatically reduce the time required to process and analyse extremely large network traces. This architecture derives from initial research, which has shown GPU co-processors to be effective in accelerating packet classification to up to tera-bit speeds with minimal CPU overhead, far exceeding the bandwidth capacity between standard long term storage and the GPU device. This paper provides a high-level overview of the proposed architecture and its primary components, motivated by the results of prior research in the field.
- Full Text:
- Date Issued: 2013
- Authors: Nottingham, Alastair , Irwin, Barry V W
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429572 , vital:72623 , 10.1109/ISSA.2013.6641052
- Description: This paper proposes a high-level architecture to support efficient, massively parallel packet classification, filtering and analysis using commodity Graphics Processing Unit (GPU) hardware. The proposed architecture aims to provide a flexible and efficient parallel packet processing and analysis framework, supporting complex programmable filtering, data mining operations, statistical analysis functions and traffic visualisation, with minimal CPU overhead. In particular, this framework aims to provide a robust set of high-speed analysis functionality, in order to dramatically reduce the time required to process and analyse extremely large network traces. This architecture derives from initial research, which has shown GPU co-processors to be effective in accelerating packet classification to up to tera-bit speeds with minimal CPU overhead, far exceeding the bandwidth capacity between standard long term storage and the GPU device. This paper provides a high-level overview of the proposed architecture and its primary components, motivated by the results of prior research in the field.
- Full Text:
- Date Issued: 2013
A kernel-driven framework for high performance internet routing simulation
- Herbert, Alan, Irwin, Barry V W
- Authors: Herbert, Alan , Irwin, Barry V W
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429585 , vital:72624 , 10.1109/ISSA.2013.6641048
- Description: The ability to provide the simulation of packets traversing an internet path is an integral part of providing realistic simulations for network training, and cyber defence exercises. This paper builds on previous work, and considers an in-kernel approach to solving the routing simulation problem. The inkernel approach is anticipated to allow the framework to be able to achieve throughput rates of 1GB/s or higher using commodity hardware. Processes that run outside the context of the kernel of most operating system require context switching to access hardware and kernel modules. This leads to considerable delays in the processes, such as network simulators, that frequently access hardware such as hard disk accesses and network packet handling. To mitigate this problem, as experienced with earlier implementations, this research looks towards implementing a kernel module to handle network routing and simulation within a UNIX based system. This would remove delays incurred from context switching and allows for direct access to the hardware components of the host.
- Full Text:
- Date Issued: 2013
- Authors: Herbert, Alan , Irwin, Barry V W
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429585 , vital:72624 , 10.1109/ISSA.2013.6641048
- Description: The ability to provide the simulation of packets traversing an internet path is an integral part of providing realistic simulations for network training, and cyber defence exercises. This paper builds on previous work, and considers an in-kernel approach to solving the routing simulation problem. The inkernel approach is anticipated to allow the framework to be able to achieve throughput rates of 1GB/s or higher using commodity hardware. Processes that run outside the context of the kernel of most operating system require context switching to access hardware and kernel modules. This leads to considerable delays in the processes, such as network simulators, that frequently access hardware such as hard disk accesses and network packet handling. To mitigate this problem, as experienced with earlier implementations, this research looks towards implementing a kernel module to handle network routing and simulation within a UNIX based system. This would remove delays incurred from context switching and allows for direct access to the hardware components of the host.
- Full Text:
- Date Issued: 2013
Deep Routing Simulation
- Irwin, Barry V W, Herbert, Alan
- Authors: Irwin, Barry V W , Herbert, Alan
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430353 , vital:72685 , https://www.academic-bookshop.com/ourshop/prod_2546879-ICIW-2013-8th-International-Conference-on-Information-Warfare-and-Security.html
- Description: This paper discusses a dataset of some 16 million packets targeting port 445/tcp collected by a network telescope utilising a /24 netblock in South African IP address space. An initial overview of the collected data is provided. This is followed by a detailed analysis of the packet characteristics observed, including size and TTL. The peculiarities of the observed target selection and the results of the flaw in the Conficker worm's propagation algorithm are presented. An analysis of the 4 million observed source hosts is reported, grouped by both packet counts and the number of distinct hosts per network address block. Address blocks of size /8, 16 and 24 are used for groupings. The localisation, by geographic region and numerical proximity, of high ranking aggregate netblocks is highlighted. The observed shift in geopolitical origins observed during the evolution of the Conficker worm is also discussed. The paper concludes with some overall analyses, and consideration of the application of network telescopes to the monitoring of such outbreaks in the future.
- Full Text:
- Date Issued: 2013
- Authors: Irwin, Barry V W , Herbert, Alan
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430353 , vital:72685 , https://www.academic-bookshop.com/ourshop/prod_2546879-ICIW-2013-8th-International-Conference-on-Information-Warfare-and-Security.html
- Description: This paper discusses a dataset of some 16 million packets targeting port 445/tcp collected by a network telescope utilising a /24 netblock in South African IP address space. An initial overview of the collected data is provided. This is followed by a detailed analysis of the packet characteristics observed, including size and TTL. The peculiarities of the observed target selection and the results of the flaw in the Conficker worm's propagation algorithm are presented. An analysis of the 4 million observed source hosts is reported, grouped by both packet counts and the number of distinct hosts per network address block. Address blocks of size /8, 16 and 24 are used for groupings. The localisation, by geographic region and numerical proximity, of high ranking aggregate netblocks is highlighted. The observed shift in geopolitical origins observed during the evolution of the Conficker worm is also discussed. The paper concludes with some overall analyses, and consideration of the application of network telescopes to the monitoring of such outbreaks in the future.
- Full Text:
- Date Issued: 2013
Synthesis of phthalocyanine conjugates with gold nanoparticles and liposomes for photodynamic therapy
- Nombona, Nolwazi, Maduray, Kaminee, Antunes, Edith M, Karsten, Aletta, Nyokong, Tebello
- Authors: Nombona, Nolwazi , Maduray, Kaminee , Antunes, Edith M , Karsten, Aletta , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/245798 , vital:51406 , xlink:href="https://doi.org/10.1016/j.jphotobiol.2011.11.007"
- Description: The efficiency of [2,9,17,23-tetrakis-(1,6-hexanedithiol)phthalocyaninato]zinc(II) as a photodynamic therapy (PDT) agent was investigated. This compound belongs to the second generation of photosensitizers currently tested for the cellular photo-damage of cancer cells. The production of reactive oxygen species (ROS) and phototoxicity of the photosensitizer were assessed. Healthy fibroblast cells and breast cancer (MCF-7) cells were treated with either free phthalocyanine or phthalocyanine bound to either gold nanoparticles or encapsulated in liposomes. Cell viability studies showed the optimum phototoxic effect on non-malignant cells to be 4.5 J cm−2. The PDT effect of the liposome bound phthalocyanine showed extensive damage of the breast cancer cells. Gold nanoparticles only showed a modest improvement in PDT activity.
- Full Text:
- Date Issued: 2012
- Authors: Nombona, Nolwazi , Maduray, Kaminee , Antunes, Edith M , Karsten, Aletta , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/245798 , vital:51406 , xlink:href="https://doi.org/10.1016/j.jphotobiol.2011.11.007"
- Description: The efficiency of [2,9,17,23-tetrakis-(1,6-hexanedithiol)phthalocyaninato]zinc(II) as a photodynamic therapy (PDT) agent was investigated. This compound belongs to the second generation of photosensitizers currently tested for the cellular photo-damage of cancer cells. The production of reactive oxygen species (ROS) and phototoxicity of the photosensitizer were assessed. Healthy fibroblast cells and breast cancer (MCF-7) cells were treated with either free phthalocyanine or phthalocyanine bound to either gold nanoparticles or encapsulated in liposomes. Cell viability studies showed the optimum phototoxic effect on non-malignant cells to be 4.5 J cm−2. The PDT effect of the liposome bound phthalocyanine showed extensive damage of the breast cancer cells. Gold nanoparticles only showed a modest improvement in PDT activity.
- Full Text:
- Date Issued: 2012
Histological validation of gonadal macroscopic staging criteria for Labeo cylindricus (Pisces: Cyprinidae)
- Booth, Anthony J, Weyl, Olaf L F
- Authors: Booth, Anthony J , Weyl, Olaf L F
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124593 , vital:35634 , https://doi.org/10.1080/15627020.2000.11657094
- Description: Histological examination of gametogenesis revealed that the current staging criteria used to assess gonadal recrudescence of the redeye labeo, Labeo cylindricus, were adequate. Gametogenesis was qualitatively similar to that of freshwater teleosts with a clearly defined seasonal reproductive cycle. L. cylindricus undergoes seasonal gross morphological and cytological gonadal changes with previtellogenesis dominating during the winter, vitellogenic development during spring and summer culminating in large-scale spawning at the end of summer. Post-spawning mass atresia of oocytes was evident in autumn. The histological data presented support macroscopical evidence that L. cylindricus is a synchronous iteroparous spawner, reproducing over a short period each year throughout its life-span.
- Full Text:
- Date Issued: 2010
- Authors: Booth, Anthony J , Weyl, Olaf L F
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124593 , vital:35634 , https://doi.org/10.1080/15627020.2000.11657094
- Description: Histological examination of gametogenesis revealed that the current staging criteria used to assess gonadal recrudescence of the redeye labeo, Labeo cylindricus, were adequate. Gametogenesis was qualitatively similar to that of freshwater teleosts with a clearly defined seasonal reproductive cycle. L. cylindricus undergoes seasonal gross morphological and cytological gonadal changes with previtellogenesis dominating during the winter, vitellogenic development during spring and summer culminating in large-scale spawning at the end of summer. Post-spawning mass atresia of oocytes was evident in autumn. The histological data presented support macroscopical evidence that L. cylindricus is a synchronous iteroparous spawner, reproducing over a short period each year throughout its life-span.
- Full Text:
- Date Issued: 2010
Synthesis, photophysical and photochemical properties of octa-substituted antimony phthalocyanines
- Modibane, Desmond Kwena, Nyokong, Tebello
- Authors: Modibane, Desmond Kwena , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/264226 , vital:53711 , xlink:href="https://doi.org/10.1016/j.poly.2008.11.052"
- Description: This work reports on the synthesis and photophysicochemical parameters of unsubstituted [SbIIIPc]+I3- and octa-phenoxy ([SbIIIOPPc]+I3-) and -4-t-butylphenoxy ([SbIIIOTBPPc]+I3-) substituted antimony phthalocyanines. Photophysical and photochemical properties were studied for these complexes in dimethylsulfoxide, dimethylformamide and toluene. The excitation spectra of oxidized antimony (Sb(V)Pc) derivates were similar to absorption spectra. Low fluorescence quantum yields, high triplet quantum yields and low triplet lifetimes were observed as the result of heavy atom (antimony ion).
- Full Text:
- Date Issued: 2009
- Authors: Modibane, Desmond Kwena , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/264226 , vital:53711 , xlink:href="https://doi.org/10.1016/j.poly.2008.11.052"
- Description: This work reports on the synthesis and photophysicochemical parameters of unsubstituted [SbIIIPc]+I3- and octa-phenoxy ([SbIIIOPPc]+I3-) and -4-t-butylphenoxy ([SbIIIOTBPPc]+I3-) substituted antimony phthalocyanines. Photophysical and photochemical properties were studied for these complexes in dimethylsulfoxide, dimethylformamide and toluene. The excitation spectra of oxidized antimony (Sb(V)Pc) derivates were similar to absorption spectra. Low fluorescence quantum yields, high triplet quantum yields and low triplet lifetimes were observed as the result of heavy atom (antimony ion).
- Full Text:
- Date Issued: 2009
(Ferrocenylpyrazolyl)zinc(II) benzoates as catalysts for the ring opening polymerization of ε-caprolactone
- Obuah, Collins, Lochee, Yemanlall, Jordaan, Johan H L, Otto, Daniel P, Nyokong, Tebello, Darkwa, James
- Authors: Obuah, Collins , Lochee, Yemanlall , Jordaan, Johan H L , Otto, Daniel P , Nyokong, Tebello , Darkwa, James
- Language: English
- Type: Article
- Identifier: vital:7264 , http://hdl.handle.net/10962/d1020273
- Description: The reaction of Zn(OAc)2 and C6H5COOH or 3,5-NO2-C6H3COOH with 3-ferrocenylpyrazolyl-methylenepyridine (L1), 3-ferrocenyl-5-methylpyrazolyl-methylenepyridine (L2), 3-ferrocenylpyrazolyl-ethylamine (L3) and 3-ferrocenyl-5-pyrazolyl-ethylamine (L4) afford the corresponding complexes [Zn(C6H5COO)2(L1)] (1), [Zn(C6H5COO)2(L2)] (2), [Zn(3,5-NO2-C6H3COO)2(L1)] (3), [Zn(3,5-NO2-C6H3COO)2(L2)] (4), [Zn(C6H5COO)2(L3)] (5), [Zn(C6H5COO)2(L4)] (6), [Zn(3,5-NO2-C6H3COO)2(L3)] (7) and [Zn(3,5-NO2-C6H3COO)2(L4)] (8). These complexes behave as catalysts for the ring opening polymerization of ɛ-caprolactone to produce polymers with molecular weight that range from 1480 to 7080 g mol−1 and exhibited moderate to broad PDIs. Evidence of these complexes acting as catalysts was obtained from both the polymerization data and kinetic studies. The polymerization data show that variation of the [CL]/[C] from 100 to 800 produced PCL with relatively the same molecular weight indicative of a catalyst behavior. The appearance of induction period in kinetic plots strengthens the fact that these complexes are catalysts rather than initiators. MALDI-TOF MS and 1H NMR data show di-hydroxy end groups, which support the coordination mechanism rather than insertion mechanism. To understand the broad PDIs obtained for some of the polymer, the electronic properties of the zinc complexes were investigated using cyclic voltammetry. The results show that the zinc complexes containing amine based ligands are highly electrophilic therefore making them unstable, hence the broad PDIs observed for zinc complexes containing amine based ligands. Among the eight complexes investigated, complex 7 is the most active catalyst with kp value of 1.18 × 10−7 h−1 mol−1 at 110 °C. , Original publication is available at http://dx.doi.org/10.1016/j.poly.2015.02.007
- Full Text: false
- Authors: Obuah, Collins , Lochee, Yemanlall , Jordaan, Johan H L , Otto, Daniel P , Nyokong, Tebello , Darkwa, James
- Language: English
- Type: Article
- Identifier: vital:7264 , http://hdl.handle.net/10962/d1020273
- Description: The reaction of Zn(OAc)2 and C6H5COOH or 3,5-NO2-C6H3COOH with 3-ferrocenylpyrazolyl-methylenepyridine (L1), 3-ferrocenyl-5-methylpyrazolyl-methylenepyridine (L2), 3-ferrocenylpyrazolyl-ethylamine (L3) and 3-ferrocenyl-5-pyrazolyl-ethylamine (L4) afford the corresponding complexes [Zn(C6H5COO)2(L1)] (1), [Zn(C6H5COO)2(L2)] (2), [Zn(3,5-NO2-C6H3COO)2(L1)] (3), [Zn(3,5-NO2-C6H3COO)2(L2)] (4), [Zn(C6H5COO)2(L3)] (5), [Zn(C6H5COO)2(L4)] (6), [Zn(3,5-NO2-C6H3COO)2(L3)] (7) and [Zn(3,5-NO2-C6H3COO)2(L4)] (8). These complexes behave as catalysts for the ring opening polymerization of ɛ-caprolactone to produce polymers with molecular weight that range from 1480 to 7080 g mol−1 and exhibited moderate to broad PDIs. Evidence of these complexes acting as catalysts was obtained from both the polymerization data and kinetic studies. The polymerization data show that variation of the [CL]/[C] from 100 to 800 produced PCL with relatively the same molecular weight indicative of a catalyst behavior. The appearance of induction period in kinetic plots strengthens the fact that these complexes are catalysts rather than initiators. MALDI-TOF MS and 1H NMR data show di-hydroxy end groups, which support the coordination mechanism rather than insertion mechanism. To understand the broad PDIs obtained for some of the polymer, the electronic properties of the zinc complexes were investigated using cyclic voltammetry. The results show that the zinc complexes containing amine based ligands are highly electrophilic therefore making them unstable, hence the broad PDIs observed for zinc complexes containing amine based ligands. Among the eight complexes investigated, complex 7 is the most active catalyst with kp value of 1.18 × 10−7 h−1 mol−1 at 110 °C. , Original publication is available at http://dx.doi.org/10.1016/j.poly.2015.02.007
- Full Text: false