Development of styrene based imprinted sorbents for selective clean-up of metalloporphyrins in organic media
- Authors: Awokoya, Kehinde Nurudeen
- Date: 2014
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54521 , vital:26580
- Description: Most crude oils contain traces of vanadium and nickel complex with porphyrins (VTPP and NTPP) within their asphaltene fraction. Although these metals are only present in trace quantities, they have a significant and detrimental impact on the refining process by degrading the quality of intermediate and end products. Therefore, their selective removal is highly desirable. This thesis presents the development of nickel porphyrin, nickel vanadyl porphyrin imprinted nanofibers and vanadyl porphyrin imprinted polymer (MIP) particles for application as selective sorbents. Computational model based on the combination of molecular dynamics simulations and quantum mechanics was successfully applied to the styrene functional monomer selection. The particle was prepared by bulk polymerization and the nanofibers by a novel approach combining molecular imprinting and electrospinning technology. The morphologies, thermal stabilities and porosities of the imprinted sorbents were studied using SEM, TGA, and BET nitrogen gas adsorption. Chloroform was found to swell the polymer particles to a higher degree than methanol and acetonitrile. The adsorption characteristics of the imprinted sorbents best fitted with Freundlich isotherm model. The imprinted sorbents recorded high extraction efficiencies (EEs) of > 99 % in selectively extracting the metalloporphyrins. The impact of the template on the affinity of recognition for NTPP was evaluated. The results showed that the NTPP adsorption capacity increased as the molar ratio of NTPP to styrene was increased from 1:1 to 3:1. The optimal ratio of template to functional monomer which yielded the best specific affinity and highest recovery (99.9 %) was 3:1. The effects of trifluoroacetic acid (TFA), dichloromethane (DCM), dimethyl sulphoxide (DMSO), pentane (PEN) on electro-spinnability of the polymer solutions and the morphological appearance of the nanofibers were investigated. The imprinted nanofibers exhibited the same selectivity specialism for both NTPP and VTPP. A remarkable stability in relation to reusability was observed when imprinted nanofibers were used, as they could be reused nine times without incurring any significant loss in removal efficiency. The results were validated by analysing a certified reference material. The imprinted sorbents were therefore found to be selective sorbents that are well suited for handling trace metals in organic media.
- Full Text:
- Date Issued: 2014
- Authors: Awokoya, Kehinde Nurudeen
- Date: 2014
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/54521 , vital:26580
- Description: Most crude oils contain traces of vanadium and nickel complex with porphyrins (VTPP and NTPP) within their asphaltene fraction. Although these metals are only present in trace quantities, they have a significant and detrimental impact on the refining process by degrading the quality of intermediate and end products. Therefore, their selective removal is highly desirable. This thesis presents the development of nickel porphyrin, nickel vanadyl porphyrin imprinted nanofibers and vanadyl porphyrin imprinted polymer (MIP) particles for application as selective sorbents. Computational model based on the combination of molecular dynamics simulations and quantum mechanics was successfully applied to the styrene functional monomer selection. The particle was prepared by bulk polymerization and the nanofibers by a novel approach combining molecular imprinting and electrospinning technology. The morphologies, thermal stabilities and porosities of the imprinted sorbents were studied using SEM, TGA, and BET nitrogen gas adsorption. Chloroform was found to swell the polymer particles to a higher degree than methanol and acetonitrile. The adsorption characteristics of the imprinted sorbents best fitted with Freundlich isotherm model. The imprinted sorbents recorded high extraction efficiencies (EEs) of > 99 % in selectively extracting the metalloporphyrins. The impact of the template on the affinity of recognition for NTPP was evaluated. The results showed that the NTPP adsorption capacity increased as the molar ratio of NTPP to styrene was increased from 1:1 to 3:1. The optimal ratio of template to functional monomer which yielded the best specific affinity and highest recovery (99.9 %) was 3:1. The effects of trifluoroacetic acid (TFA), dichloromethane (DCM), dimethyl sulphoxide (DMSO), pentane (PEN) on electro-spinnability of the polymer solutions and the morphological appearance of the nanofibers were investigated. The imprinted nanofibers exhibited the same selectivity specialism for both NTPP and VTPP. A remarkable stability in relation to reusability was observed when imprinted nanofibers were used, as they could be reused nine times without incurring any significant loss in removal efficiency. The results were validated by analysing a certified reference material. The imprinted sorbents were therefore found to be selective sorbents that are well suited for handling trace metals in organic media.
- Full Text:
- Date Issued: 2014
Development of tourism diploma in IsiXhosa-speaking students' academic literacies : a multilingual intervention
- Authors: Batyi, Thokozile Thelma
- Date: 2014
- Subjects: Education, Bilingual -- South Africa -- Port Elizabeth , Language and languages -- Study and teaching -- South Africa -- Port Elizabeth , Education -- Study and teaching (Higher) -- South Africa -- Port Elizabeth , Multilingual communication -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:8369 , http://hdl.handle.net/10948/d1020194
- Description: In this study, it is argued that a bi/multilingual instruction is extremely beneficial for bi/multilingual students in higher education in South Africa. Since the adoption of democracy in 1994, cultural and linguistic diversity has become the norm in classrooms at Nelson Mandela Metropolitan University in Port Elizabeth. The testing of bi/multilingual strategies in this study (i.e. translation and development of multilingual glossaries; code-switching by tutor and students during teaching and learning; code-meshing by students online; and reading, speaking and writing bilingually), is an attempt to pedagogically adapt the curriculum to students’ needs. The data was collected from students in their Tourism Communication tutorial. The study was conducted in order to demonstrate that students benefit from bilingual pedagogies, which mobilise isiXhosa and English as languages of learning. Data was collected from tests, a questionnaire and interview, summaries, online discussions, written assignments and reflective journals in order to determine to what extent students’ performance was enhanced by bilingual tuition.
- Full Text:
- Date Issued: 2014
- Authors: Batyi, Thokozile Thelma
- Date: 2014
- Subjects: Education, Bilingual -- South Africa -- Port Elizabeth , Language and languages -- Study and teaching -- South Africa -- Port Elizabeth , Education -- Study and teaching (Higher) -- South Africa -- Port Elizabeth , Multilingual communication -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:8369 , http://hdl.handle.net/10948/d1020194
- Description: In this study, it is argued that a bi/multilingual instruction is extremely beneficial for bi/multilingual students in higher education in South Africa. Since the adoption of democracy in 1994, cultural and linguistic diversity has become the norm in classrooms at Nelson Mandela Metropolitan University in Port Elizabeth. The testing of bi/multilingual strategies in this study (i.e. translation and development of multilingual glossaries; code-switching by tutor and students during teaching and learning; code-meshing by students online; and reading, speaking and writing bilingually), is an attempt to pedagogically adapt the curriculum to students’ needs. The data was collected from students in their Tourism Communication tutorial. The study was conducted in order to demonstrate that students benefit from bilingual pedagogies, which mobilise isiXhosa and English as languages of learning. Data was collected from tests, a questionnaire and interview, summaries, online discussions, written assignments and reflective journals in order to determine to what extent students’ performance was enhanced by bilingual tuition.
- Full Text:
- Date Issued: 2014
Diagnosing the sexual pattern of Diplodus cervinus hottentotus (Pisces: Sparidae) from southern Angola
- Winkler, Alexander C, Santos, Carmen V D, Potts, Warren M
- Authors: Winkler, Alexander C , Santos, Carmen V D , Potts, Warren M
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124286 , vital:35589 , https://doi.10.1007/s11160-006-9034-6
- Description: The sexual pattern of Diplodus cervinus hottentotus was investigated in southern Angola. Females were significantly smaller and found in greater numbers, with an adult sex ratio of 1.0:0.7, F:M. Histological observations of preserved gonads indicated that the species is a rudimentary hermaphrodite, possessing a non-functional bisexual ovotestis before maturation. Histological examination of five macroscopically staged ‘bisexual’ individuals revealed that they were functional males with residual ovarian tissue in the gonad, which had persisted from a juvenile bisexual stage. Although empirical population structure and macroscopic observations suggested protogyny, histological evidence suggested otherwise, confirming the need for the use of histology when diagnosing the sexual pattern of sparid fishes.
- Full Text:
- Date Issued: 2014
- Authors: Winkler, Alexander C , Santos, Carmen V D , Potts, Warren M
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124286 , vital:35589 , https://doi.10.1007/s11160-006-9034-6
- Description: The sexual pattern of Diplodus cervinus hottentotus was investigated in southern Angola. Females were significantly smaller and found in greater numbers, with an adult sex ratio of 1.0:0.7, F:M. Histological observations of preserved gonads indicated that the species is a rudimentary hermaphrodite, possessing a non-functional bisexual ovotestis before maturation. Histological examination of five macroscopically staged ‘bisexual’ individuals revealed that they were functional males with residual ovarian tissue in the gonad, which had persisted from a juvenile bisexual stage. Although empirical population structure and macroscopic observations suggested protogyny, histological evidence suggested otherwise, confirming the need for the use of histology when diagnosing the sexual pattern of sparid fishes.
- Full Text:
- Date Issued: 2014
Dialogic pedagogical innovation for liberating learning practices: a case of one programme in a higher education institution in South Africa
- Authors: Mudehwe, Florence Rutendo
- Date: 2014
- Subjects: Educational change -- South Africa , School improvement programs -- South Africa , Critical pedagogy , Curriculum evaluation -- South Africa , Education --Study and teaching
- Language: English
- Type: Thesis , Doctoral , PhD (Education)
- Identifier: vital:16225 , http://hdl.handle.net/10353/d1019737 , Educational change -- South Africa , School improvement programs -- South Africa , Critical pedagogy , Curriculum evaluation -- South Africa , Education --Study and teaching
- Description: The past two to three decades have seen unprecedented expansion in enrolments in Universities across the world. Increased participation rates in Higher Education, however, has not been matched by a corresponding increase in success rates as reflected in students' poor retention rates and unsatisfactory outcomes. One strand of explanation claims that students, for a variety of reasons, come to university `unprepared' and suffer an articulation gap in the transition between high school and university; the other explanation seeks to move away from the deficit perspective and puts emphasis on the need to enrich experiences of students to enable them to exercise agency and change constraining circumstances in order to succeed. This study reports on one programme, a grounding programme known as the Life, Knowledge and Action (LKA) in one South African university. One of the central purposes of the LKA is to enrich students' first year experiences through liberating dialogue embedded in its pedagogical architecture. A sequential mixed methods study was carried out. A survey of first year students who had been exposed to the LKA was first carried out. This was followed by a case study of purposively selected first year students. Findings show that LKA promoted dialogue in varied ways depending on the level of the pedagogical architecture. At Umzi level students as peers across disciplines exchanged ideas freely about their circumstances and social issues. At the Ekhaya level where the abakwezeli (facilitators) were active, power dynamics emerged between students and the facilitators which had the effect of diminishing dialogical moments. At village level, there was not much discussion; instead there was a lot of lecturing. Dialogue was limited to a few minutes of discussion at the end of the lecture. The other finding was that seen from Archer's lens of morphogenetic analysis, the `articulation gap' can be seen as a structural constraint, that can be addressed through liberating dialogue which enables the students to question the status quo. There was evidence that through dialogue in the LKA, students felt that it liberated them in the sense that it exposed them to different perspectives as well as enabled them to explore alternatives. It can be concluded that through an appropriately designed dialogical pedagogy, students can be empowered to transform the structural constraints to their education and create enablers that can help them succeed in their learning. There is evidence that within the LKA pedagogical architecture, the students have the opportunity to take responsibility for their learning and thus enabled to exercise agency. It is recommended that the processes that take place at each level of the LKA architecture must be further studied with a view to discovering mechanisms at work that may undermine the liberating thrust of the programme. As a liberating core curriculum, LKA must not be limited to first year students; consideration must be given to roll it out across the levels of the undergraduate offerings.
- Full Text:
- Date Issued: 2014
- Authors: Mudehwe, Florence Rutendo
- Date: 2014
- Subjects: Educational change -- South Africa , School improvement programs -- South Africa , Critical pedagogy , Curriculum evaluation -- South Africa , Education --Study and teaching
- Language: English
- Type: Thesis , Doctoral , PhD (Education)
- Identifier: vital:16225 , http://hdl.handle.net/10353/d1019737 , Educational change -- South Africa , School improvement programs -- South Africa , Critical pedagogy , Curriculum evaluation -- South Africa , Education --Study and teaching
- Description: The past two to three decades have seen unprecedented expansion in enrolments in Universities across the world. Increased participation rates in Higher Education, however, has not been matched by a corresponding increase in success rates as reflected in students' poor retention rates and unsatisfactory outcomes. One strand of explanation claims that students, for a variety of reasons, come to university `unprepared' and suffer an articulation gap in the transition between high school and university; the other explanation seeks to move away from the deficit perspective and puts emphasis on the need to enrich experiences of students to enable them to exercise agency and change constraining circumstances in order to succeed. This study reports on one programme, a grounding programme known as the Life, Knowledge and Action (LKA) in one South African university. One of the central purposes of the LKA is to enrich students' first year experiences through liberating dialogue embedded in its pedagogical architecture. A sequential mixed methods study was carried out. A survey of first year students who had been exposed to the LKA was first carried out. This was followed by a case study of purposively selected first year students. Findings show that LKA promoted dialogue in varied ways depending on the level of the pedagogical architecture. At Umzi level students as peers across disciplines exchanged ideas freely about their circumstances and social issues. At the Ekhaya level where the abakwezeli (facilitators) were active, power dynamics emerged between students and the facilitators which had the effect of diminishing dialogical moments. At village level, there was not much discussion; instead there was a lot of lecturing. Dialogue was limited to a few minutes of discussion at the end of the lecture. The other finding was that seen from Archer's lens of morphogenetic analysis, the `articulation gap' can be seen as a structural constraint, that can be addressed through liberating dialogue which enables the students to question the status quo. There was evidence that through dialogue in the LKA, students felt that it liberated them in the sense that it exposed them to different perspectives as well as enabled them to explore alternatives. It can be concluded that through an appropriately designed dialogical pedagogy, students can be empowered to transform the structural constraints to their education and create enablers that can help them succeed in their learning. There is evidence that within the LKA pedagogical architecture, the students have the opportunity to take responsibility for their learning and thus enabled to exercise agency. It is recommended that the processes that take place at each level of the LKA architecture must be further studied with a view to discovering mechanisms at work that may undermine the liberating thrust of the programme. As a liberating core curriculum, LKA must not be limited to first year students; consideration must be given to roll it out across the levels of the undergraduate offerings.
- Full Text:
- Date Issued: 2014
Die ervaring van die geregistreerde verpleegkundedosent ten opsigte van die kliniese begeleiding van verpleegstudente
- Authors: De Wet, Annemie
- Date: 2014
- Subjects: Nursing students , Mentoring in nursing -- South Africa
- Language: Afrikaans
- Type: Thesis , Masters , MCur
- Identifier: vital:10053 , http://hdl.handle.net/10948/1018275
- Description: Die doel van die studie was om vas te stel hoe die verpleegkundedosent die begeleiding van verpleegstudente in die praktyk ervaar. In die verlede was begeleiding van verpleegstudente met praktika in gesondheidsorginstansies deur ʼn professionele verpleegkundige gedoen wat deel was van die personeel se verantwoordelikhede. Die verpleegstudente doen hul teoretiese kennis op by ʼn tersiêre instansie en verkry hul praktiese kennis by ʼn geakkrediteerde gesondheidsorginstansie soos vereis deur die Suid-Afrikaanse Raad op Verpleging (SARV). Een van die take van ‘n verpleegkundedosent van die privaat opleidingskool is om die kliniese begeleiding van verpleegstudente in geakkrediteerde instellings te doen. Omdat verpleging ʼn beroep is waar vaardighede belangrik is, is praktiese inoefening van prosedures en evaluering van die verpleegstudente se vaardigheid daarin noodsaaklik. Die verpleegstudente is heeltyd besig met die pasiënte in die vorm van prosedures waarby die teorie wat in die opleidingskool verkry was, gekorreleer moet word met die prosedure om die hele prentjie te vorm. Dit is dus nodig dat begeleiding van die verpleegstudente gedoen moet word om vaardigheid en toepassing van kennis te verseker. Die navorser het ʼn kwalitatiewe, ondersoekende, beskrywende en kontekstuele studie gedoen waarvan die populasie die geregistreerde dosente van verskeie provinsiale en privaatverpleegskole in die Klein-Karoo en Suid-kaapdistrikte was. Die navorser het gebruik gemaak van ʼn nie-waarskynlike steekproef. Inligtingryke data was ingesamel deur semi-gestruktureerde onderhoude wat aangevul was met veldnotas soos verkry tydens onderhoude. Data-ontleding was reeds begin met data-insameling en Tesch se inhoudsontleding was gebruik om ʼn mening te vorm. ‘n Literatuurkontrole was gedoen om te bepaal wat vorige navorsing oor begeleiding bevind en aanbeveel het. Lincoln en Guba se model was gebruik vir betroubaarheidsversekering volgens die kriteria wat hulle aanbeveel het, naamlik geloofwaardigheid, oordraagbaarheid, betroubaarheid en bevestigbaarheid. Uit die data-ontleding het vier belangrike temas en subtemas te voorskyn gekom. Die temas was dat die verpleegkundedosente aspekte van die begeleiding van verpleegstudente in die gesondheidsorginstansie as positief en ook as negatief beleef. Die wyse waarop die gesondheidsorginstansies bestuur word, het die begeleiding beïnvloed en daar was riglyne voorgestel wat die kliniese personeel en dosente kan rig wanneer hulle betrokke raak by die begeleiding van verpleegstudente. Die begeleiding van verpleegstudente deur verpleegkundedosente, kliniese dosente en die gesondheidsorginstansie se opgeleide personeel, is ʼn belangrike deel van verpleegopleiding en bepaal uiteindelik die kwaliteit van die pasiëntsorg wat verskaf word deur die verpleegkundiges. Die navorser het riglyne daar gestel om die begeleiding van vepleegstudente te rig. Die riglyne moet nou geïmplementeer en getoets word binne die konteks van die bepaalde verpleegskole en dan weer geëvalueer word. Beperkings wat ondervind was in die studie was dat die steekproef ʼn klein groepie verpleegkundedosente op die platteland was, wat veralgemening bemoeilik, veral in die stedelike konteks. Die begeleiding van die verpleegstudente is gedoen met die ingeskrewe verpleegstudente (Die Suid-Afrikaanse Raad op Verpleging Regulasies, Regulasie 2176 en 2175 van 19 November 1993), naamlik die kategorie met die minste status en verantwoordelikheid onder verpleegstudente. Veralgemening na alle kategorieë, veral verpleegstudente besig met professionele verpleegprogramme, mag dus nie sinvol wees nie.
- Full Text:
- Date Issued: 2014
- Authors: De Wet, Annemie
- Date: 2014
- Subjects: Nursing students , Mentoring in nursing -- South Africa
- Language: Afrikaans
- Type: Thesis , Masters , MCur
- Identifier: vital:10053 , http://hdl.handle.net/10948/1018275
- Description: Die doel van die studie was om vas te stel hoe die verpleegkundedosent die begeleiding van verpleegstudente in die praktyk ervaar. In die verlede was begeleiding van verpleegstudente met praktika in gesondheidsorginstansies deur ʼn professionele verpleegkundige gedoen wat deel was van die personeel se verantwoordelikhede. Die verpleegstudente doen hul teoretiese kennis op by ʼn tersiêre instansie en verkry hul praktiese kennis by ʼn geakkrediteerde gesondheidsorginstansie soos vereis deur die Suid-Afrikaanse Raad op Verpleging (SARV). Een van die take van ‘n verpleegkundedosent van die privaat opleidingskool is om die kliniese begeleiding van verpleegstudente in geakkrediteerde instellings te doen. Omdat verpleging ʼn beroep is waar vaardighede belangrik is, is praktiese inoefening van prosedures en evaluering van die verpleegstudente se vaardigheid daarin noodsaaklik. Die verpleegstudente is heeltyd besig met die pasiënte in die vorm van prosedures waarby die teorie wat in die opleidingskool verkry was, gekorreleer moet word met die prosedure om die hele prentjie te vorm. Dit is dus nodig dat begeleiding van die verpleegstudente gedoen moet word om vaardigheid en toepassing van kennis te verseker. Die navorser het ʼn kwalitatiewe, ondersoekende, beskrywende en kontekstuele studie gedoen waarvan die populasie die geregistreerde dosente van verskeie provinsiale en privaatverpleegskole in die Klein-Karoo en Suid-kaapdistrikte was. Die navorser het gebruik gemaak van ʼn nie-waarskynlike steekproef. Inligtingryke data was ingesamel deur semi-gestruktureerde onderhoude wat aangevul was met veldnotas soos verkry tydens onderhoude. Data-ontleding was reeds begin met data-insameling en Tesch se inhoudsontleding was gebruik om ʼn mening te vorm. ‘n Literatuurkontrole was gedoen om te bepaal wat vorige navorsing oor begeleiding bevind en aanbeveel het. Lincoln en Guba se model was gebruik vir betroubaarheidsversekering volgens die kriteria wat hulle aanbeveel het, naamlik geloofwaardigheid, oordraagbaarheid, betroubaarheid en bevestigbaarheid. Uit die data-ontleding het vier belangrike temas en subtemas te voorskyn gekom. Die temas was dat die verpleegkundedosente aspekte van die begeleiding van verpleegstudente in die gesondheidsorginstansie as positief en ook as negatief beleef. Die wyse waarop die gesondheidsorginstansies bestuur word, het die begeleiding beïnvloed en daar was riglyne voorgestel wat die kliniese personeel en dosente kan rig wanneer hulle betrokke raak by die begeleiding van verpleegstudente. Die begeleiding van verpleegstudente deur verpleegkundedosente, kliniese dosente en die gesondheidsorginstansie se opgeleide personeel, is ʼn belangrike deel van verpleegopleiding en bepaal uiteindelik die kwaliteit van die pasiëntsorg wat verskaf word deur die verpleegkundiges. Die navorser het riglyne daar gestel om die begeleiding van vepleegstudente te rig. Die riglyne moet nou geïmplementeer en getoets word binne die konteks van die bepaalde verpleegskole en dan weer geëvalueer word. Beperkings wat ondervind was in die studie was dat die steekproef ʼn klein groepie verpleegkundedosente op die platteland was, wat veralgemening bemoeilik, veral in die stedelike konteks. Die begeleiding van die verpleegstudente is gedoen met die ingeskrewe verpleegstudente (Die Suid-Afrikaanse Raad op Verpleging Regulasies, Regulasie 2176 en 2175 van 19 November 1993), naamlik die kategorie met die minste status en verantwoordelikheid onder verpleegstudente. Veralgemening na alle kategorieë, veral verpleegstudente besig met professionele verpleegprogramme, mag dus nie sinvol wees nie.
- Full Text:
- Date Issued: 2014
Diet and microhabitat use of the woodland dormouse Graphiurus murinus at the Great Fish River Reserve, Eastern Cape, South Africa
- Authors: Lamani, Siviwe
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Zoology)
- Identifier: vital:11797 , http://hdl.handle.net/10353/d1019854
- Description: The diet of the woodland dormouse Graphiurus murinus was studied in a riverine Combretum forest at the Great Fish River Reserve (Eastern Cape, South Africa). Food remains were collected seasonally from a maximum of 45 different nest boxes between December 2010 and November 2011. An overall mean of 1.32 ± 0.51 food categories (range 1–4) were identified in each nest box used as “larder” during the year. Dietary diversity and standardized diet breadth were low to intermediate, with a peak in summer and a nadir in winter. In terms of percentage occurrence, arthropods were dominant (99%) in all seasons, followed by molluscs (16%) and fruits (14%). When relative percentage occurrence and percentage weight were considered, arthropods were still dominant, but a slight decrease was observed in summer. Besides spiders (order Araneae), nine arthropod families were found in the diet of the woodland dormouse; Tenebrionidae (40%), Spirostreptidae (30%), Carabidae (15%) and Blattidae (14%) were the most dominant families in terms of percentage weight. Grewia robusta and Ziziphus mucronata were the only fruit species present in the diet. Pianka’s diet overlap indices were very high (>0.93), indicating that the diet of the woodland dormouse was similar between pairs of seasons. This study also investigated whether woodland dormice Graphiurus murinus positively select or avoid specific microhabitat types or structures, and whether a set of predictor variables related to microhabitat characteristics can explain the presence and rates of visits to specific trapping stations. Trapping was conducted seasonally, over 5 days, between June 2011 and April 2012. A grid of 96 stations (16 rows × 6 lines) was established. Trap stations were set at 10-m intervals. At each station two Sherman traps were placed. The 192 traps were distributed relatively equitably among four height categories (0–0.5 m, 0.51–1 m, 1.01–1.5 m, and 1.51–2.5 m). On average, trapping success was 4.70 ± 4.17 dormice per 100 traps. Dormice were trapped at an average height of 136 ± 64 cm, which was significantly higher than the average height at which traps were set (99 ± 75 cm). Bonferroni Z tests indicated that dormice positively selected areas with high canopy cover and connectivity, possibly to decrease predation risk. Generalized Linear Models showed that trap use and numbers of visits and different animals caught were positively associated with a high arboreal connectivity, hence supporting the hypothesis that woodland dormice may depend on wooden “corridors” for their movements.
- Full Text:
- Date Issued: 2014
- Authors: Lamani, Siviwe
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Zoology)
- Identifier: vital:11797 , http://hdl.handle.net/10353/d1019854
- Description: The diet of the woodland dormouse Graphiurus murinus was studied in a riverine Combretum forest at the Great Fish River Reserve (Eastern Cape, South Africa). Food remains were collected seasonally from a maximum of 45 different nest boxes between December 2010 and November 2011. An overall mean of 1.32 ± 0.51 food categories (range 1–4) were identified in each nest box used as “larder” during the year. Dietary diversity and standardized diet breadth were low to intermediate, with a peak in summer and a nadir in winter. In terms of percentage occurrence, arthropods were dominant (99%) in all seasons, followed by molluscs (16%) and fruits (14%). When relative percentage occurrence and percentage weight were considered, arthropods were still dominant, but a slight decrease was observed in summer. Besides spiders (order Araneae), nine arthropod families were found in the diet of the woodland dormouse; Tenebrionidae (40%), Spirostreptidae (30%), Carabidae (15%) and Blattidae (14%) were the most dominant families in terms of percentage weight. Grewia robusta and Ziziphus mucronata were the only fruit species present in the diet. Pianka’s diet overlap indices were very high (>0.93), indicating that the diet of the woodland dormouse was similar between pairs of seasons. This study also investigated whether woodland dormice Graphiurus murinus positively select or avoid specific microhabitat types or structures, and whether a set of predictor variables related to microhabitat characteristics can explain the presence and rates of visits to specific trapping stations. Trapping was conducted seasonally, over 5 days, between June 2011 and April 2012. A grid of 96 stations (16 rows × 6 lines) was established. Trap stations were set at 10-m intervals. At each station two Sherman traps were placed. The 192 traps were distributed relatively equitably among four height categories (0–0.5 m, 0.51–1 m, 1.01–1.5 m, and 1.51–2.5 m). On average, trapping success was 4.70 ± 4.17 dormice per 100 traps. Dormice were trapped at an average height of 136 ± 64 cm, which was significantly higher than the average height at which traps were set (99 ± 75 cm). Bonferroni Z tests indicated that dormice positively selected areas with high canopy cover and connectivity, possibly to decrease predation risk. Generalized Linear Models showed that trap use and numbers of visits and different animals caught were positively associated with a high arboreal connectivity, hence supporting the hypothesis that woodland dormice may depend on wooden “corridors” for their movements.
- Full Text:
- Date Issued: 2014
Diet of the yellow mongoose (Cynictis penicillata) in the Albany Thicket Biome of South Africa
- Authors: Bizani, Mfundo
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Zoology)
- Identifier: vital:11796 , http://hdl.handle.net/10353/d1019840
- Description: The dietary habits of the yellow mongoose Cynictis penicillata were studied in the Albany Thicket Biome of South Africa (Great Fish River Reserve, Eastern Cape). The diet was investigated through the analysis of 1,056 scats that were sampled over a period of 7 years (2005−2009 and 2011−2012) mainly in three similar sites (Kelarny, Grasslands and Junction 10) that were used by at least three families or groups of yellow mongooses. Scats were collected near latrine sites, labelled and stored in a freezer. In the laboratory, scats were oven dried for a period of 24 hours at 50 C. Diet was determined by identifying undigested food remains in the scats. Hair samples were examined under the compound microscope to identify which mammals were ingested. In the field, both arthropod and small mammal abundance were determined in order to evaluate whether yellow mongooses are opportunistic or specialist feeders. Furthermore, inter-annual (2006–2008) and inter-group/inter-site variations in the diet were assessed. Based on faecal analysis, arthropods were the principal prey, while small mammals acted as supplementary food item. Other food categories like vegetation, reptiles and birds were only ingested or preyed upon infrequently. Intermediate dietary diversity, and low standardised diet breadth indices were obtained for all seasons, as well as for the whole sampling period. The diet overlaps calculated for pairs of seasons were very high and did not differ substantially. However, the diet of the yellow mongoose varied seasonally, yearly and between groups (sites), mostly due to variations in arthropod and small mammal consumption. Food availability displayed an increase in biomass of both small mammals and arthropods in summer and autumn. Results obtained in this study could suggest that the yellow mongoose at the GFRR is insectivorous by preferring to feed on insects (and arthropods in general) when both insects and rodents are abundant. However the fact that its diet varies both seasonally, yearly and locally, as well as the presence of remains of other food categories in the scats, indicates that this species is rather an opportunistic, generalist feeder than an insect specialist.
- Full Text:
- Date Issued: 2014
- Authors: Bizani, Mfundo
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Zoology)
- Identifier: vital:11796 , http://hdl.handle.net/10353/d1019840
- Description: The dietary habits of the yellow mongoose Cynictis penicillata were studied in the Albany Thicket Biome of South Africa (Great Fish River Reserve, Eastern Cape). The diet was investigated through the analysis of 1,056 scats that were sampled over a period of 7 years (2005−2009 and 2011−2012) mainly in three similar sites (Kelarny, Grasslands and Junction 10) that were used by at least three families or groups of yellow mongooses. Scats were collected near latrine sites, labelled and stored in a freezer. In the laboratory, scats were oven dried for a period of 24 hours at 50 C. Diet was determined by identifying undigested food remains in the scats. Hair samples were examined under the compound microscope to identify which mammals were ingested. In the field, both arthropod and small mammal abundance were determined in order to evaluate whether yellow mongooses are opportunistic or specialist feeders. Furthermore, inter-annual (2006–2008) and inter-group/inter-site variations in the diet were assessed. Based on faecal analysis, arthropods were the principal prey, while small mammals acted as supplementary food item. Other food categories like vegetation, reptiles and birds were only ingested or preyed upon infrequently. Intermediate dietary diversity, and low standardised diet breadth indices were obtained for all seasons, as well as for the whole sampling period. The diet overlaps calculated for pairs of seasons were very high and did not differ substantially. However, the diet of the yellow mongoose varied seasonally, yearly and between groups (sites), mostly due to variations in arthropod and small mammal consumption. Food availability displayed an increase in biomass of both small mammals and arthropods in summer and autumn. Results obtained in this study could suggest that the yellow mongoose at the GFRR is insectivorous by preferring to feed on insects (and arthropods in general) when both insects and rodents are abundant. However the fact that its diet varies both seasonally, yearly and locally, as well as the presence of remains of other food categories in the scats, indicates that this species is rather an opportunistic, generalist feeder than an insect specialist.
- Full Text:
- Date Issued: 2014
Dietary aspects of establishing a mainland-based colony of the endangered African Penguin (Spheniscus demersus) in St Francis Bay, South Africa
- Authors: Voogt, Nina Margaret
- Date: 2014
- Subjects: African penguin -- South Africa -- Cape Saint Francis , African penguin -- Food -- South Africa -- Algoa Bay , African penguin -- Habitat suitability index models -- South Africa -- Cape Saint Francis , Stable isotopes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5875 , http://hdl.handle.net/10962/d1013115
- Description: Cape St Francis, Eastern Cape, has been identified as one of four potential sites for establishing a mainland-based African penguin (Spheniscus demersus) colony. This thesis comprises three main components: a verification of a preparation method for stable isotope samples from penguin feathers; a dietary analysis of the penguins on Bird Island, Algoa Bay, though stable isotope analysis of whole blood and feathers (2012 and 2013); and an estimation of available fish surplus that could potentially support a colony of penguins at Cape St Francis. Each component contributes towards the next, all building towards answering the main research question: Will there be enough food around St Francis Bay to support a colony of penguins and sustain the already established fisheries industry within the bay? Stable isotope analysis of whole blood and feathers from breeding adults and whole blood from juveniles provided insight into the variability of African penguins’ diets at different stages in their life history. Stable isotope mixing models indicated that the predicted proportions that each prey species could potentially contribute to diet conflicted with published stomach sample data. This might arise from inaccurate trophic enrichment factors used in the model, or from systematic biases in the published stomach sampling techniques, or both. Dietary sexual dimorphism was not demonstrated by the isotope signatures of breeding penguins. Based on official catch data, the fisheries activity on the south coast, and especially around the potential colony site at St Francis, is much lower than around the west coast’s penguin colonies. The model provided a first-order estimate for fish supply around the potential colony site at St Francis both at a large coastal scale and a local small scale. At both scales the estimate indicated an ample availability of fish at current fishing levels. The model in Chapter 4 can also be applied to refining the assessments of other potential colony sites on the south coast. In conclusion, the south coast is a promising area for a new colony of penguins in terms of food availability. There is relatively low fishing activity in the area and, as suggested by the large-scale model in Chapter 4, an ample fish resource. The final chapter briefly discusses factors that need to be considered before attempting to establish a mainland-based colony of African penguins.
- Full Text:
- Date Issued: 2014
- Authors: Voogt, Nina Margaret
- Date: 2014
- Subjects: African penguin -- South Africa -- Cape Saint Francis , African penguin -- Food -- South Africa -- Algoa Bay , African penguin -- Habitat suitability index models -- South Africa -- Cape Saint Francis , Stable isotopes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5875 , http://hdl.handle.net/10962/d1013115
- Description: Cape St Francis, Eastern Cape, has been identified as one of four potential sites for establishing a mainland-based African penguin (Spheniscus demersus) colony. This thesis comprises three main components: a verification of a preparation method for stable isotope samples from penguin feathers; a dietary analysis of the penguins on Bird Island, Algoa Bay, though stable isotope analysis of whole blood and feathers (2012 and 2013); and an estimation of available fish surplus that could potentially support a colony of penguins at Cape St Francis. Each component contributes towards the next, all building towards answering the main research question: Will there be enough food around St Francis Bay to support a colony of penguins and sustain the already established fisheries industry within the bay? Stable isotope analysis of whole blood and feathers from breeding adults and whole blood from juveniles provided insight into the variability of African penguins’ diets at different stages in their life history. Stable isotope mixing models indicated that the predicted proportions that each prey species could potentially contribute to diet conflicted with published stomach sample data. This might arise from inaccurate trophic enrichment factors used in the model, or from systematic biases in the published stomach sampling techniques, or both. Dietary sexual dimorphism was not demonstrated by the isotope signatures of breeding penguins. Based on official catch data, the fisheries activity on the south coast, and especially around the potential colony site at St Francis, is much lower than around the west coast’s penguin colonies. The model provided a first-order estimate for fish supply around the potential colony site at St Francis both at a large coastal scale and a local small scale. At both scales the estimate indicated an ample availability of fish at current fishing levels. The model in Chapter 4 can also be applied to refining the assessments of other potential colony sites on the south coast. In conclusion, the south coast is a promising area for a new colony of penguins in terms of food availability. There is relatively low fishing activity in the area and, as suggested by the large-scale model in Chapter 4, an ample fish resource. The final chapter briefly discusses factors that need to be considered before attempting to establish a mainland-based colony of African penguins.
- Full Text:
- Date Issued: 2014
Differential motif enrichment analysis of paired ChIP-seq experiments
- Lesluyes, Tom, Johnson, James, Machanick, Philip, Bailey, Timothy L
- Authors: Lesluyes, Tom , Johnson, James , Machanick, Philip , Bailey, Timothy L
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439250 , vital:73559 , https://doi.org/10.1186/1471-2164-15-752
- Description: Motif enrichment analysis of transcription factor ChIP-seq data can help identify transcription factors that cooperate or compete. Previously, little attention has been given to comparative motif enrichment analysis of pairs of ChIP-seq experiments, where the binding of the same transcription factor is assayed under different conditions. Such comparative analysis could potentially identify the distinct regulatory partners/competitors of the assayed transcription factor under different conditions or at different stages of development.
- Full Text:
- Date Issued: 2014
- Authors: Lesluyes, Tom , Johnson, James , Machanick, Philip , Bailey, Timothy L
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439250 , vital:73559 , https://doi.org/10.1186/1471-2164-15-752
- Description: Motif enrichment analysis of transcription factor ChIP-seq data can help identify transcription factors that cooperate or compete. Previously, little attention has been given to comparative motif enrichment analysis of pairs of ChIP-seq experiments, where the binding of the same transcription factor is assayed under different conditions. Such comparative analysis could potentially identify the distinct regulatory partners/competitors of the assayed transcription factor under different conditions or at different stages of development.
- Full Text:
- Date Issued: 2014
Digital disruption: some instagrams
- Authors: Garman, Anthea
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144558 , vital:38357 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC159516
- Description: I'm going to shamelessly pinch someone else's language to think about the changes and challenges of this media moment we are living through and take the theme for the Mennel Media Exchange (MMX14), organised by Laurie Bley of Duke University and Patrick Conroy of eNCA and held in Johannesburg in July. “ Digital disruption" doesn't fallen into the neat pessimism or optimism so emblematic of our times but does say forcefully that we are all on uncertain ground and need to reconfigure our ways of doing and being in media making, media managing and in education.
- Full Text:
- Date Issued: 2014
- Authors: Garman, Anthea
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144558 , vital:38357 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC159516
- Description: I'm going to shamelessly pinch someone else's language to think about the changes and challenges of this media moment we are living through and take the theme for the Mennel Media Exchange (MMX14), organised by Laurie Bley of Duke University and Patrick Conroy of eNCA and held in Johannesburg in July. “ Digital disruption" doesn't fallen into the neat pessimism or optimism so emblematic of our times but does say forcefully that we are all on uncertain ground and need to reconfigure our ways of doing and being in media making, media managing and in education.
- Full Text:
- Date Issued: 2014
Digital multimedia network with parameter join mechanism
- Gurdan, Robby, Foss, Richard
- Authors: Gurdan, Robby , Foss, Richard
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427059 , vital:72411 , https://patentimages.storage.googleapis.com/ae/e3/6a/0afc332b8afaea/US8855008.pdf
- Description: A digital multimedia network with a parameter join mechanism comprising at least one apparatus. A requesting device parameter of a source apparatus updates a local parameter group list by adding an entry for each device parameter of a target apparatus which joins the parameter group.
- Full Text:
- Date Issued: 2014
- Authors: Gurdan, Robby , Foss, Richard
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427059 , vital:72411 , https://patentimages.storage.googleapis.com/ae/e3/6a/0afc332b8afaea/US8855008.pdf
- Description: A digital multimedia network with a parameter join mechanism comprising at least one apparatus. A requesting device parameter of a source apparatus updates a local parameter group list by adding an entry for each device parameter of a target apparatus which joins the parameter group.
- Full Text:
- Date Issued: 2014
Digital storytelling to explore HIV- and AIDS- related stigma with secondary school learners in a rural community in KwaZulu-Natal
- Authors: Mnisi, Thoko Esther
- Date: 2014
- Subjects: AIDS (Disease) in adolescence -- Social aspects -- Africa, Southern , HIV infections -- Social aspects -- Africa, Southern , Stigma (Social psychology) -- South Africa -- KwaZulu-Natal , Digital storytelling
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9576 , http://hdl.handle.net/10948/d1018717
- Description: This study explores, through digital storytelling, the experiences of HIV- and AIDS-related stigma of rural community secondary school learners. HIV- and AIDS-related stigma is seen as an impediment to a proficient response to HIV and AIDS in communities, also rural communities, and requires addressing. The rural community in which the research is undertaken is particularly hard hit by HIV and AIDS. Learners’ experiences of HIV- and AIDS related stigma could therefore inform how school and community could engage with HIV- and AIDS-related stigma and how they could address it in a constructive way. The study attempts to respond to two research questions: What can digital storytelling reveal about secondary school learners’ experiences of HIV- and AIDS-related stigma in schools in a rural community? How can digital storytelling enable secondary school learners in school in a rural community to take action to address stigma? This qualitative study is positioned within a critical paradigm, and employs a community-based participatory research strategy. Twelve Grade 8 and 9 male and female learners aged 15 to 18 years, from two secondary schools in rural Vulindlela district of KwaZulu-Natal, South Africa, who experienced, witnessed or heard about HIV- and AIDS-related stigma participated. Digital storytelling, a visual participatory method, was used to generate the data, and this was complemented by group discussion and written pieces completed by the participants in reflection sessions. The thematic analysis of the data made use of participatory analysis: the analysis of the digital stories was done by the participants while the overarching analysis was done by the researcher. This study, located in the field of the Psychology of Education, is informed by the theoretical framework of symbolic interactionism. In terms of the experienced stigma, it was found that living with HIV and AIDS and the related stigma is perceived as a ‘hardship’. The stigma is experienced on many levels: in the family, at school, and from friends and members of the community. It has an impact on the individual on an intrapersonal and interpersonal level. The young person is caught up in a vicious cycle of silent suffering since there are no reliable and trustworthy people with whom he or she can share these challenges. Some so-called traditional beliefs and customs such as not talking about sex, and practices like virginity testing, also fuel HIV- and AIDS-related stigma. The use of derogatory terms and the severe criticism of early sexual debut along with the gossiping which is used to spread the stigmatising statements further complicate the hardship experienced by young people. Digital storytelling was found to not only enable the learners’ voices to be heard but also to enable their taking charge of the stigma and thus create the space for critical participation in this research. The implications for the study are that the pervasive stigma that young people experience should be addressed at every level of the community. The stakeholders such as the families, school, educators, the King (Inkosi) and Chiefs (Indunas) of the area, relevant departments with that of Education taking the lead, must work hand-in-hand with the affected young people. Such collaboration may allow for the identification of the problem, for reflection on it, and also for the addressing of it. HIV- and AIDS-related stigma, while it has changed since the emergence of HIV, still is an issue that many HIV-positive individuals have to contend with. This stigma is, however, contextual and how the individual is stigmatised fits in with the language, meaning and thought that a community constructs around stigma. While digital storytelling enables the uncovering of particular stories of stigma that learners experience in the context of a school in a rural community, the digital storytelling in and of itself enables a change in the language, meaning and thought around stigma in its drawing on the specifics of the stigma as experienced in the community. Also, digital storytelling is about sharing stories about, and experiences of HIV- and AIDS-related stigma and how these stories can be used as part of the solution. If such stories can be told, people can spread them just as gossip is spread, but in this case such spreading would work towards positive social change. I claim that in order to confront the challenges raised by the perpetuation of stigma, efforts must involve the communities and must tap into their own experiences of perpetuating or enduring stigmatisation. Suggestions by the very same people from the community who are at the front line of perpetuating and /or suffering the stigma must be considered. This may also become one way of instantly communicating the research findings back to the community involved in the research. Using digital storytelling can ensure getting self-tailored, contextual, specific views on how HIV- and AIDS-related stigma is experienced but also how it could be addressed.
- Full Text:
- Date Issued: 2014
- Authors: Mnisi, Thoko Esther
- Date: 2014
- Subjects: AIDS (Disease) in adolescence -- Social aspects -- Africa, Southern , HIV infections -- Social aspects -- Africa, Southern , Stigma (Social psychology) -- South Africa -- KwaZulu-Natal , Digital storytelling
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9576 , http://hdl.handle.net/10948/d1018717
- Description: This study explores, through digital storytelling, the experiences of HIV- and AIDS-related stigma of rural community secondary school learners. HIV- and AIDS-related stigma is seen as an impediment to a proficient response to HIV and AIDS in communities, also rural communities, and requires addressing. The rural community in which the research is undertaken is particularly hard hit by HIV and AIDS. Learners’ experiences of HIV- and AIDS related stigma could therefore inform how school and community could engage with HIV- and AIDS-related stigma and how they could address it in a constructive way. The study attempts to respond to two research questions: What can digital storytelling reveal about secondary school learners’ experiences of HIV- and AIDS-related stigma in schools in a rural community? How can digital storytelling enable secondary school learners in school in a rural community to take action to address stigma? This qualitative study is positioned within a critical paradigm, and employs a community-based participatory research strategy. Twelve Grade 8 and 9 male and female learners aged 15 to 18 years, from two secondary schools in rural Vulindlela district of KwaZulu-Natal, South Africa, who experienced, witnessed or heard about HIV- and AIDS-related stigma participated. Digital storytelling, a visual participatory method, was used to generate the data, and this was complemented by group discussion and written pieces completed by the participants in reflection sessions. The thematic analysis of the data made use of participatory analysis: the analysis of the digital stories was done by the participants while the overarching analysis was done by the researcher. This study, located in the field of the Psychology of Education, is informed by the theoretical framework of symbolic interactionism. In terms of the experienced stigma, it was found that living with HIV and AIDS and the related stigma is perceived as a ‘hardship’. The stigma is experienced on many levels: in the family, at school, and from friends and members of the community. It has an impact on the individual on an intrapersonal and interpersonal level. The young person is caught up in a vicious cycle of silent suffering since there are no reliable and trustworthy people with whom he or she can share these challenges. Some so-called traditional beliefs and customs such as not talking about sex, and practices like virginity testing, also fuel HIV- and AIDS-related stigma. The use of derogatory terms and the severe criticism of early sexual debut along with the gossiping which is used to spread the stigmatising statements further complicate the hardship experienced by young people. Digital storytelling was found to not only enable the learners’ voices to be heard but also to enable their taking charge of the stigma and thus create the space for critical participation in this research. The implications for the study are that the pervasive stigma that young people experience should be addressed at every level of the community. The stakeholders such as the families, school, educators, the King (Inkosi) and Chiefs (Indunas) of the area, relevant departments with that of Education taking the lead, must work hand-in-hand with the affected young people. Such collaboration may allow for the identification of the problem, for reflection on it, and also for the addressing of it. HIV- and AIDS-related stigma, while it has changed since the emergence of HIV, still is an issue that many HIV-positive individuals have to contend with. This stigma is, however, contextual and how the individual is stigmatised fits in with the language, meaning and thought that a community constructs around stigma. While digital storytelling enables the uncovering of particular stories of stigma that learners experience in the context of a school in a rural community, the digital storytelling in and of itself enables a change in the language, meaning and thought around stigma in its drawing on the specifics of the stigma as experienced in the community. Also, digital storytelling is about sharing stories about, and experiences of HIV- and AIDS-related stigma and how these stories can be used as part of the solution. If such stories can be told, people can spread them just as gossip is spread, but in this case such spreading would work towards positive social change. I claim that in order to confront the challenges raised by the perpetuation of stigma, efforts must involve the communities and must tap into their own experiences of perpetuating or enduring stigmatisation. Suggestions by the very same people from the community who are at the front line of perpetuating and /or suffering the stigma must be considered. This may also become one way of instantly communicating the research findings back to the community involved in the research. Using digital storytelling can ensure getting self-tailored, contextual, specific views on how HIV- and AIDS-related stigma is experienced but also how it could be addressed.
- Full Text:
- Date Issued: 2014
Direct and indirect effects of zooplanktivorous predators on the estuarine plankton community
- Authors: Wasserman, Ryan John
- Date: 2014
- Subjects: Zooplankton -- Effect of predation on , Predation (Biology) , Zooplankton -- Predators of , Copepoda
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5870 , http://hdl.handle.net/10962/d1012938
- Description: Although predation has been identified as a potentially important driver in terrestrial and freshwater ecosystems, estuarine planktonic research has focused largely on the so-called "bottom-up" drivers of community assemblages. As such, this thesis focuses on the direct and indirect effects of zooplanktivorous predators on the planktonic community in an estuarine environment. By using a suite of in situ mesocosm experiments, a number of hypotheses, pertaining to the major research themes associated with predator-prey interactions, are tested. These themes included trophic cascading, risk effects associated with predation events and the importance of predator diversity in maintaining prey communities. The first experiment assessed the significance of apex predation pressure for the planktonic community through trophic cascades. Various treatments using in situ mesocosms were established in a closed oligotrophic estuary to highlight the importance of predation in stabilising estuarine plankton abundances. Through either the removal (filtration) or addition of certain planktonic groups, varied trophic scenarios were established. The experimental treatment containing apex zooplanktivores had consequences for multiple trophic levels, exerting a stabilising pressure throughout the food web (Chapter 3). Furthermore, pyrosequencing of filtered water samples revealed that when compared to the remaining treatments, the treatment containing stable apex predatory pressure experienced limited temporal deviation-from-initial in bacterial community structure (Chapter 4). These findings are consistent with trophic cascade theory whereby predators mediate interactions at multiple lower trophic levels with consequent repercussions for diversity. To assess the non-consumptive effects of predators on prey, two experiments were conducted. Firstly, using egg numbers per clutch as a measure of potential reproductive output, the non-lethal effects of predatory pressure on reproductive success in a key planktonic copepod was investigated. In this study, the average clutch size of fecund female copepods was found to be consistently lower in the presence of predators when compared to females not exposed to predation threat (Chapter 5). The second study assessed the effects of conspecific chemical alarm cues associated with predation, on population dynamics of a copepod species. This study revealed that the copepods appear to detect the presence of chemical alarm cues associated with predation events, with repercussions for population demographics over time. Furthermore, it showed that in the absence of actual predation, copepod prey responses to alarm cues were adjusted over time, consistent with the threat sensitive predator avoidance hypothesis (Chapter 6). The final data chapter dealt with predator diversity and its implications for zooplankton community structure. By experimentally monitoring the effects of two alternate model predators on the metazoan community over time, dissimilarities in community level control emerged. Alternate key prey populations were regulated by the different model predators, highlighting the importance of predator and prey behaviour in mediating predator-prey interactions (Chapter 7). These results highlight the potential importance of predators in maintaining community dynamics in estuarine planktonic communities under certain conditions. This study represents some of the first work to address these various aspects of predator-prey dynamics within the context of planktonic estuarine ecology.
- Full Text:
- Date Issued: 2014
- Authors: Wasserman, Ryan John
- Date: 2014
- Subjects: Zooplankton -- Effect of predation on , Predation (Biology) , Zooplankton -- Predators of , Copepoda
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5870 , http://hdl.handle.net/10962/d1012938
- Description: Although predation has been identified as a potentially important driver in terrestrial and freshwater ecosystems, estuarine planktonic research has focused largely on the so-called "bottom-up" drivers of community assemblages. As such, this thesis focuses on the direct and indirect effects of zooplanktivorous predators on the planktonic community in an estuarine environment. By using a suite of in situ mesocosm experiments, a number of hypotheses, pertaining to the major research themes associated with predator-prey interactions, are tested. These themes included trophic cascading, risk effects associated with predation events and the importance of predator diversity in maintaining prey communities. The first experiment assessed the significance of apex predation pressure for the planktonic community through trophic cascades. Various treatments using in situ mesocosms were established in a closed oligotrophic estuary to highlight the importance of predation in stabilising estuarine plankton abundances. Through either the removal (filtration) or addition of certain planktonic groups, varied trophic scenarios were established. The experimental treatment containing apex zooplanktivores had consequences for multiple trophic levels, exerting a stabilising pressure throughout the food web (Chapter 3). Furthermore, pyrosequencing of filtered water samples revealed that when compared to the remaining treatments, the treatment containing stable apex predatory pressure experienced limited temporal deviation-from-initial in bacterial community structure (Chapter 4). These findings are consistent with trophic cascade theory whereby predators mediate interactions at multiple lower trophic levels with consequent repercussions for diversity. To assess the non-consumptive effects of predators on prey, two experiments were conducted. Firstly, using egg numbers per clutch as a measure of potential reproductive output, the non-lethal effects of predatory pressure on reproductive success in a key planktonic copepod was investigated. In this study, the average clutch size of fecund female copepods was found to be consistently lower in the presence of predators when compared to females not exposed to predation threat (Chapter 5). The second study assessed the effects of conspecific chemical alarm cues associated with predation, on population dynamics of a copepod species. This study revealed that the copepods appear to detect the presence of chemical alarm cues associated with predation events, with repercussions for population demographics over time. Furthermore, it showed that in the absence of actual predation, copepod prey responses to alarm cues were adjusted over time, consistent with the threat sensitive predator avoidance hypothesis (Chapter 6). The final data chapter dealt with predator diversity and its implications for zooplankton community structure. By experimentally monitoring the effects of two alternate model predators on the metazoan community over time, dissimilarities in community level control emerged. Alternate key prey populations were regulated by the different model predators, highlighting the importance of predator and prey behaviour in mediating predator-prey interactions (Chapter 7). These results highlight the potential importance of predators in maintaining community dynamics in estuarine planktonic communities under certain conditions. This study represents some of the first work to address these various aspects of predator-prey dynamics within the context of planktonic estuarine ecology.
- Full Text:
- Date Issued: 2014
Director's duties under the Companies Act 71 of 2008
- Authors: van Tonder, Jan-Louis
- Date: 2014
- Subjects: South Africa -- Companies Act, 2008 Corporation law -- South Africa , Commercial law -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10948/47892 , vital:40397
- Description: This research focuses on an analysis of the prescribed standards of directors’ conduct provision. The thesis of the dissertation is to analyse what this provision introduces into statute. Previously, the fiduciary duties and the duty of care and skill were regulated by the common law and case law. In May 2004 the Department of Trade and Industry released a policy document entitled South African Company Law for the 21st Century Guidelines for Corporate Law Reform. The policy document acknowledged that South Africa had no extensive statutory dispensation that covered the duties of directors. The policy document recognised the need to bring South African company law in line with international trends and to reflect and accommodate the changing environment for businesses locally and internationally. For the first time in South Africa’s corporate law history, the Companies Act 71 of 2008 partially codifies the fiduciary duties of directors, the duty of care and skill and introduces the business judgment rule into South African company law. The research establishes what the standards of conduct are that are expected of directors and analyses the meaning of these duties in the standards of directors’ conduct provision. The research examines whether the duties introduced in the standards of conduct provision are aligned to the common law principles. It will consider whether the standards of conduct provision amends the common law principles, adds anything new or narrows the common law duties in its statutory format.
- Full Text:
- Date Issued: 2014
- Authors: van Tonder, Jan-Louis
- Date: 2014
- Subjects: South Africa -- Companies Act, 2008 Corporation law -- South Africa , Commercial law -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10948/47892 , vital:40397
- Description: This research focuses on an analysis of the prescribed standards of directors’ conduct provision. The thesis of the dissertation is to analyse what this provision introduces into statute. Previously, the fiduciary duties and the duty of care and skill were regulated by the common law and case law. In May 2004 the Department of Trade and Industry released a policy document entitled South African Company Law for the 21st Century Guidelines for Corporate Law Reform. The policy document acknowledged that South Africa had no extensive statutory dispensation that covered the duties of directors. The policy document recognised the need to bring South African company law in line with international trends and to reflect and accommodate the changing environment for businesses locally and internationally. For the first time in South Africa’s corporate law history, the Companies Act 71 of 2008 partially codifies the fiduciary duties of directors, the duty of care and skill and introduces the business judgment rule into South African company law. The research establishes what the standards of conduct are that are expected of directors and analyses the meaning of these duties in the standards of directors’ conduct provision. The research examines whether the duties introduced in the standards of conduct provision are aligned to the common law principles. It will consider whether the standards of conduct provision amends the common law principles, adds anything new or narrows the common law duties in its statutory format.
- Full Text:
- Date Issued: 2014
Distribution of heavy minerals sand in Namalope deposit, Moma district, Mozambique
- Authors: Assane, Ali Ossufo
- Date: 2014
- Subjects: Heavy minerals -- Mozambique -- Moma District , Prospecting -- Mozambique -- Moma District , Mines and mineral resources -- Mozambique -- Moma District , Ilmenite -- Research , Zircon -- Research , Rutile -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5056 , http://hdl.handle.net/10962/d1012169 , Heavy minerals -- Mozambique -- Moma District , Prospecting -- Mozambique -- Moma District , Mines and mineral resources -- Mozambique -- Moma District , Ilmenite -- Research , Zircon -- Research , Rutile -- Research
- Description: The spatial distribution of heavy minerals along the mine paths 2014 and 2015 at the wet concentrate plant B shows an increase of heavy minerals sand concentration northwards and slime contents southwards, and it is commonly associated with depth and grain sorting; the increase of heavy minerals concentration with depth is considered to be from the surface formed by Unit 6 to the bottom of Unit 7. The Unit 82 is characterized by low heavy minerals concentrations and high slime contents declining northwards. The mineral proportion estimation suggests that ilmenite is the most abundant heavy mineral in the entire area followed by zircon, rutile and mozanite, and some accessory minerals such as chromite, kyanite, staurolite, tourmaline, epidote, spinel and quartz. The ilmenite occurrence is divided into ilmenite low (< 53% TiO₂) and high (> 53% TiO₂); the ilmenite high with zircon and rutile shows tendency to increase northwards while ilmenite low increase southwards. Zircon, monazite, rutile, chromite, kyanite and staurolite show low variability, which is probably associated with high resistance of minerals for abrasion during transportation and diagenesis. The depositional model of the Namalope deposit, in the flat area and wet concentrate plant B in particular, suggests deposition in a shallow marine environment associated with regression for deposition of Unit 6, 7 and 9 and transgression during deposition of Unit 82. The spatial distribution of heavy minerals in the Namalope deposit and its environment of deposition are the key points for discovery of new deposits around the Namalope with the same characteristic of mineral assemblage and they are used for mine strategic plans such as update block model and mine design.
- Full Text:
- Date Issued: 2014
- Authors: Assane, Ali Ossufo
- Date: 2014
- Subjects: Heavy minerals -- Mozambique -- Moma District , Prospecting -- Mozambique -- Moma District , Mines and mineral resources -- Mozambique -- Moma District , Ilmenite -- Research , Zircon -- Research , Rutile -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5056 , http://hdl.handle.net/10962/d1012169 , Heavy minerals -- Mozambique -- Moma District , Prospecting -- Mozambique -- Moma District , Mines and mineral resources -- Mozambique -- Moma District , Ilmenite -- Research , Zircon -- Research , Rutile -- Research
- Description: The spatial distribution of heavy minerals along the mine paths 2014 and 2015 at the wet concentrate plant B shows an increase of heavy minerals sand concentration northwards and slime contents southwards, and it is commonly associated with depth and grain sorting; the increase of heavy minerals concentration with depth is considered to be from the surface formed by Unit 6 to the bottom of Unit 7. The Unit 82 is characterized by low heavy minerals concentrations and high slime contents declining northwards. The mineral proportion estimation suggests that ilmenite is the most abundant heavy mineral in the entire area followed by zircon, rutile and mozanite, and some accessory minerals such as chromite, kyanite, staurolite, tourmaline, epidote, spinel and quartz. The ilmenite occurrence is divided into ilmenite low (< 53% TiO₂) and high (> 53% TiO₂); the ilmenite high with zircon and rutile shows tendency to increase northwards while ilmenite low increase southwards. Zircon, monazite, rutile, chromite, kyanite and staurolite show low variability, which is probably associated with high resistance of minerals for abrasion during transportation and diagenesis. The depositional model of the Namalope deposit, in the flat area and wet concentrate plant B in particular, suggests deposition in a shallow marine environment associated with regression for deposition of Unit 6, 7 and 9 and transgression during deposition of Unit 82. The spatial distribution of heavy minerals in the Namalope deposit and its environment of deposition are the key points for discovery of new deposits around the Namalope with the same characteristic of mineral assemblage and they are used for mine strategic plans such as update block model and mine design.
- Full Text:
- Date Issued: 2014
Distribution of iron-titanium oxides in the vanadiferous main magnetite seam of the upper zone : Northern limb, Bushveld complex
- Authors: Gwatinetsa, Demand
- Date: 2014
- Subjects: Igneous rocks -- South Africa -- Bushveld Complex , Sulfide minerals -- South Africa -- Bushveld Complex , Vanadium -- South Africa -- Bushveld Complex , Titanium dioxide -- South Africa -- Bushveld Complex , Ferric oxide -- South Africa -- Bushveld Complex , Geology -- South Africa -- Bushveld Complex , Mineralogy -- South Africa -- Bushveld Complex , Mines and mineral resources -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5063 , http://hdl.handle.net/10962/d1013281
- Description: The main magnetite seam of the Upper Zone of the Rustenburg Layered Suite (SACS, 1980) on the Bushveld Complex is known to host the world‘s largest vanadium bearing titaniferous iron ores. The vanadiferous titanomagnetites, contain vanadium in sufficient concentrations (1.2 - 2.2 per cent V₂O₅) to be considered as resources and vanadium has been mined historically by a number of companies among them Anglo-American, Highveld Steel and Vanadium and VanMag Resources as well as currently by Evraz Highveld Steel and Vanadium Limited of South Africa. The titanomagnetites contain iron ore in the form of magnetite and titanium with concentrations averaging 50-75 per cent FeO and 12-21 per cent TiO₂. The titaniferous iron ores have been historically dismissed as a source of iron and titanium, due to the known difficulties of using iron ore with high titania content in blast furnaces. The economic potential for the extractability of the titaniferous magnetites lies in the capacity of the ores to be separated into iron rich and titanium rich concentrates usually through, crushing, grinding and magnetic separation. The separatability of iron oxides and titanium oxides, is dependent on the nature in which the titanium oxide occurs, with granular ilmenite being the most favourable since it can be separated from magnetite via magnetic separation. Titanium that occurs as finely exsolved lamellae or as iron-titanium oxides with low titania content such as ulvospinel render the potential recoverability of titanium poor. The Upper Zone vanadiferous titanomagnetites contain titanium in various forms varying from discrete granular ilmenite to finely exsolved lamellae as well as occurring as part of the minerals ulvospinel (Fe₂TiO₄) and titanomagnetite (a solid solution series between ulvospinel and magnetite) . Discrete ilmenite constitutes between 3-5 per cent by volume of the massive titanomagnetite ores, and between 5-10 per cent by volume of the magnetite-plagioclase cumulates with more than 50 per cent opaque oxide minerals. The purpose of this research was to investigate the mineralogical setting and distribution of the iron and titanium oxides within the magnetitite layers from top to bottom as well as spatially along a strike length of 2 000m to determine the potential for the titanium to be extracted from the titanomagnetite ores. The titanomagnetites of the Upper Zone of the Bushveld Complex with particular reference to the Northern Limb where this research was conducted contains titanium oxides as discrete ilmenite grains but in low concentrations whose potential for separate economic extraction will be challenging. The highest concentration of titanium in the magnetite ores is not contained in the granular ilmenite, but rather in ulvospinel and titanomagnetite as illustrated by the marked higher concentration of TiO₂ in the massive ores which contain less granular ilmenite in comparison to the disseminated ores which contain 3 to 8 percentage points higher granular ilmenite than the massive ores. On the scale of the main magnetite seam, the TiO₂ content increases with increasing stratigraphic height from being completely absent in the footwall anorthosite. The V₂2O₅ content also increases with stratigraphic height except for in one of the 3 boreholes where it drops with increasing height. The decrease or increase patterns are repeated in every seam. The titanomagnetites of the main magnetite seam display a variety of textures from coarse granular magnetite and ilmenite, to trellis ilmenite lamellae, intergranular ilmenite and magnesian spinels and fine exsolution lamellae of ulvospinel and ferro-magnesian spinels parallel to the magnetite cleavage. The bottom contact of the main magnetite seam is very sharp and there is no titanium or vanadium in the footwall barely 10cm below the contact. Chromium is present in the bottom of the 4 layers that constitute the main magnetite seam and it upwards decreases rapidly. In boreholes P21 and P55, there are slight reversals in the TiO₂ and V₂O₅ content towards the top of the magnetite seams.
- Full Text:
- Date Issued: 2014
- Authors: Gwatinetsa, Demand
- Date: 2014
- Subjects: Igneous rocks -- South Africa -- Bushveld Complex , Sulfide minerals -- South Africa -- Bushveld Complex , Vanadium -- South Africa -- Bushveld Complex , Titanium dioxide -- South Africa -- Bushveld Complex , Ferric oxide -- South Africa -- Bushveld Complex , Geology -- South Africa -- Bushveld Complex , Mineralogy -- South Africa -- Bushveld Complex , Mines and mineral resources -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5063 , http://hdl.handle.net/10962/d1013281
- Description: The main magnetite seam of the Upper Zone of the Rustenburg Layered Suite (SACS, 1980) on the Bushveld Complex is known to host the world‘s largest vanadium bearing titaniferous iron ores. The vanadiferous titanomagnetites, contain vanadium in sufficient concentrations (1.2 - 2.2 per cent V₂O₅) to be considered as resources and vanadium has been mined historically by a number of companies among them Anglo-American, Highveld Steel and Vanadium and VanMag Resources as well as currently by Evraz Highveld Steel and Vanadium Limited of South Africa. The titanomagnetites contain iron ore in the form of magnetite and titanium with concentrations averaging 50-75 per cent FeO and 12-21 per cent TiO₂. The titaniferous iron ores have been historically dismissed as a source of iron and titanium, due to the known difficulties of using iron ore with high titania content in blast furnaces. The economic potential for the extractability of the titaniferous magnetites lies in the capacity of the ores to be separated into iron rich and titanium rich concentrates usually through, crushing, grinding and magnetic separation. The separatability of iron oxides and titanium oxides, is dependent on the nature in which the titanium oxide occurs, with granular ilmenite being the most favourable since it can be separated from magnetite via magnetic separation. Titanium that occurs as finely exsolved lamellae or as iron-titanium oxides with low titania content such as ulvospinel render the potential recoverability of titanium poor. The Upper Zone vanadiferous titanomagnetites contain titanium in various forms varying from discrete granular ilmenite to finely exsolved lamellae as well as occurring as part of the minerals ulvospinel (Fe₂TiO₄) and titanomagnetite (a solid solution series between ulvospinel and magnetite) . Discrete ilmenite constitutes between 3-5 per cent by volume of the massive titanomagnetite ores, and between 5-10 per cent by volume of the magnetite-plagioclase cumulates with more than 50 per cent opaque oxide minerals. The purpose of this research was to investigate the mineralogical setting and distribution of the iron and titanium oxides within the magnetitite layers from top to bottom as well as spatially along a strike length of 2 000m to determine the potential for the titanium to be extracted from the titanomagnetite ores. The titanomagnetites of the Upper Zone of the Bushveld Complex with particular reference to the Northern Limb where this research was conducted contains titanium oxides as discrete ilmenite grains but in low concentrations whose potential for separate economic extraction will be challenging. The highest concentration of titanium in the magnetite ores is not contained in the granular ilmenite, but rather in ulvospinel and titanomagnetite as illustrated by the marked higher concentration of TiO₂ in the massive ores which contain less granular ilmenite in comparison to the disseminated ores which contain 3 to 8 percentage points higher granular ilmenite than the massive ores. On the scale of the main magnetite seam, the TiO₂ content increases with increasing stratigraphic height from being completely absent in the footwall anorthosite. The V₂2O₅ content also increases with stratigraphic height except for in one of the 3 boreholes where it drops with increasing height. The decrease or increase patterns are repeated in every seam. The titanomagnetites of the main magnetite seam display a variety of textures from coarse granular magnetite and ilmenite, to trellis ilmenite lamellae, intergranular ilmenite and magnesian spinels and fine exsolution lamellae of ulvospinel and ferro-magnesian spinels parallel to the magnetite cleavage. The bottom contact of the main magnetite seam is very sharp and there is no titanium or vanadium in the footwall barely 10cm below the contact. Chromium is present in the bottom of the 4 layers that constitute the main magnetite seam and it upwards decreases rapidly. In boreholes P21 and P55, there are slight reversals in the TiO₂ and V₂O₅ content towards the top of the magnetite seams.
- Full Text:
- Date Issued: 2014
Diversity management practices at Lovedale College
- Authors: Chola, Zolani
- Date: 2014
- Subjects: Diversity in the workplace -- South Africa -- King William's Town , Public universities and colleges -- South Africa -- King William's Town
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9392 , http://hdl.handle.net/10948/d1021163
- Description: The global working environment has altered dramatically over the last decade and in particular, the workforce has begun to consist of many diverse individuals. The world has become a global marketplace, with boundaries between countries becoming increasingly vague and permeable. Advances in technology and the advent of a global economy have brought people from different countries closer together. Globalisation has precipitated many challenges in modern organisations, and one of these challenges is workforce diversity. Workforces in organisations differ in terms of gender, age, race, ethnicity and sexual orientation. Globally, countries are faced with the spiralling challenge of skills shortages and there is an expanding competition for skilled workers, specifically for those who possess scarce skills. This leads to an expatriation of skills, creating a natural increase in workforce diversity that expands beyond local ethnicity and language. This affects all organisations, including academic institutions such as universities, universities of technology and public further education and training colleges. Given this challenge organisations, educational institutions and other entities are investigating ways to better deal or serve their constituents. Lovedale PFET College is a public further education and training college that provides skills to young South Africans, specifically vocational related skills. The main research problem of this study was to identify the recommended diversity management best practices that characterise effective organisations and determine the extent to which these practices are applied at Lovedale PFET College. In order to address the problem, a theoretical study was conducted which focused on identifying the recommended diversity management best practices. In addition, interviews were conducted with managers at Lovedale College to gain an understanding of their perspective on diversity management. Based on the combined main points gleaned from theory and the interviews, a questionnaire was developed and administered to both academic and support staff at Lovedale PFET College to obtain their perceptions of the diversity practices and outcomes at the college. The results of the survey revealed that Lovedale PFET College could improve on the implementation of best practices in diversity management. Specifically, attention could be given to diversity education and training, and diversity management policies and procedures.
- Full Text:
- Date Issued: 2014
- Authors: Chola, Zolani
- Date: 2014
- Subjects: Diversity in the workplace -- South Africa -- King William's Town , Public universities and colleges -- South Africa -- King William's Town
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9392 , http://hdl.handle.net/10948/d1021163
- Description: The global working environment has altered dramatically over the last decade and in particular, the workforce has begun to consist of many diverse individuals. The world has become a global marketplace, with boundaries between countries becoming increasingly vague and permeable. Advances in technology and the advent of a global economy have brought people from different countries closer together. Globalisation has precipitated many challenges in modern organisations, and one of these challenges is workforce diversity. Workforces in organisations differ in terms of gender, age, race, ethnicity and sexual orientation. Globally, countries are faced with the spiralling challenge of skills shortages and there is an expanding competition for skilled workers, specifically for those who possess scarce skills. This leads to an expatriation of skills, creating a natural increase in workforce diversity that expands beyond local ethnicity and language. This affects all organisations, including academic institutions such as universities, universities of technology and public further education and training colleges. Given this challenge organisations, educational institutions and other entities are investigating ways to better deal or serve their constituents. Lovedale PFET College is a public further education and training college that provides skills to young South Africans, specifically vocational related skills. The main research problem of this study was to identify the recommended diversity management best practices that characterise effective organisations and determine the extent to which these practices are applied at Lovedale PFET College. In order to address the problem, a theoretical study was conducted which focused on identifying the recommended diversity management best practices. In addition, interviews were conducted with managers at Lovedale College to gain an understanding of their perspective on diversity management. Based on the combined main points gleaned from theory and the interviews, a questionnaire was developed and administered to both academic and support staff at Lovedale PFET College to obtain their perceptions of the diversity practices and outcomes at the college. The results of the survey revealed that Lovedale PFET College could improve on the implementation of best practices in diversity management. Specifically, attention could be given to diversity education and training, and diversity management policies and procedures.
- Full Text:
- Date Issued: 2014
DNS traffic based classifiers for the automatic classification of botnet domains
- Authors: Stalmans, Etienne Raymond
- Date: 2014
- Subjects: Denial of service attacks -- Research , Computer security -- Research , Internet -- Security measures -- Research , Malware (Computer software) , Spam (Electronic mail) , Phishing , Command and control systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4684 , http://hdl.handle.net/10962/d1007739
- Description: Networks of maliciously compromised computers, known as botnets, consisting of thousands of hosts have emerged as a serious threat to Internet security in recent years. These compromised systems, under the control of an operator are used to steal data, distribute malware and spam, launch phishing attacks and in Distributed Denial-of-Service (DDoS) attacks. The operators of these botnets use Command and Control (C2) servers to communicate with the members of the botnet and send commands. The communications channels between the C2 nodes and endpoints have employed numerous detection avoidance mechanisms to prevent the shutdown of the C2 servers. Two prevalent detection avoidance techniques used by current botnets are algorithmically generated domain names and DNS Fast-Flux. The use of these mechanisms can however be observed and used to create distinct signatures that in turn can be used to detect DNS domains being used for C2 operation. This report details research conducted into the implementation of three classes of classification techniques that exploit these signatures in order to accurately detect botnet traffic. The techniques described make use of the traffic from DNS query responses created when members of a botnet try to contact the C2 servers. Traffic observation and categorisation is passive from the perspective of the communicating nodes. The first set of classifiers explored employ frequency analysis to detect the algorithmically generated domain names used by botnets. These were found to have a high degree of accuracy with a low false positive rate. The characteristics of Fast-Flux domains are used in the second set of classifiers. It is shown that using these characteristics Fast-Flux domains can be accurately identified and differentiated from legitimate domains (such as Content Distribution Networks exhibit similar behaviour). The final set of classifiers use spatial autocorrelation to detect Fast-Flux domains based on the geographic distribution of the botnet C2 servers to which the detected domains resolve. It is shown that botnet C2 servers can be detected solely based on their geographic location. This technique is shown to clearly distinguish between malicious and legitimate domains. The implemented classifiers are lightweight and use existing network traffic to detect botnets and thus do not require major architectural changes to the network. The performance impact of implementing classification of DNS traffic is examined and it is shown that the performance impact is at an acceptable level.
- Full Text:
- Date Issued: 2014
- Authors: Stalmans, Etienne Raymond
- Date: 2014
- Subjects: Denial of service attacks -- Research , Computer security -- Research , Internet -- Security measures -- Research , Malware (Computer software) , Spam (Electronic mail) , Phishing , Command and control systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4684 , http://hdl.handle.net/10962/d1007739
- Description: Networks of maliciously compromised computers, known as botnets, consisting of thousands of hosts have emerged as a serious threat to Internet security in recent years. These compromised systems, under the control of an operator are used to steal data, distribute malware and spam, launch phishing attacks and in Distributed Denial-of-Service (DDoS) attacks. The operators of these botnets use Command and Control (C2) servers to communicate with the members of the botnet and send commands. The communications channels between the C2 nodes and endpoints have employed numerous detection avoidance mechanisms to prevent the shutdown of the C2 servers. Two prevalent detection avoidance techniques used by current botnets are algorithmically generated domain names and DNS Fast-Flux. The use of these mechanisms can however be observed and used to create distinct signatures that in turn can be used to detect DNS domains being used for C2 operation. This report details research conducted into the implementation of three classes of classification techniques that exploit these signatures in order to accurately detect botnet traffic. The techniques described make use of the traffic from DNS query responses created when members of a botnet try to contact the C2 servers. Traffic observation and categorisation is passive from the perspective of the communicating nodes. The first set of classifiers explored employ frequency analysis to detect the algorithmically generated domain names used by botnets. These were found to have a high degree of accuracy with a low false positive rate. The characteristics of Fast-Flux domains are used in the second set of classifiers. It is shown that using these characteristics Fast-Flux domains can be accurately identified and differentiated from legitimate domains (such as Content Distribution Networks exhibit similar behaviour). The final set of classifiers use spatial autocorrelation to detect Fast-Flux domains based on the geographic distribution of the botnet C2 servers to which the detected domains resolve. It is shown that botnet C2 servers can be detected solely based on their geographic location. This technique is shown to clearly distinguish between malicious and legitimate domains. The implemented classifiers are lightweight and use existing network traffic to detect botnets and thus do not require major architectural changes to the network. The performance impact of implementing classification of DNS traffic is examined and it is shown that the performance impact is at an acceptable level.
- Full Text:
- Date Issued: 2014
Domestic tax law v double tax treaties in the context of controlled foreign companies
- Authors: Froom, Natalie Marie
- Date: 2014
- Subjects: Taxation -- Law and legislation -- South Africa , Fiscal policy -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/3559 , vital:20442
- Description: The South African fiscal legislators have found it necessary to introduce anti-avoidance legislation which governs controlled foreign companies in order to counteract schemes devised by taxpayers where companies are established outside South Africa for the purpose of diverting income from the South African fiscal net. Whilst the enforcement of such legislation does have merit in that the intention behind the introduction of such domestic legislation is to prevent the erosion of the South African tax base, it is submitted that this does pose a problem from an international perspective. The objective of this treatise is to conduct a critical analysis of how compatible the South African fiscal legislation which governs controlled foreign companies is with the provisions of the double taxation agreement as prescribed in terms of the OECD Model Tax Convention (which was published in July 2010). In addition, the aim of this study is to deduce whether the purpose of the double taxation agreement is not only the avoidance of juridical double taxation but also that it addresses the avoidance of economic double taxation. This will assist in determining whether domestic controlled foreign company legislation (as embodied in section 9D of the Income Tax Act 58 of 1962) conflicts with the purpose of the double taxation agreement. By conducting an extensive research study and by depicting a certain scenario which addresses the issue at hand, the following is concluded: The tax treatment of the business profits generated by a controlled foreign company resident in a State outside South Africa and which have been generated from active business operating activities, is held to be in agreement with the provisions of the double taxation agreement. By contrast, the tax treatment of the controlled foreign company’s passive income in the form of interest income, is found not to correlate with the aforesaid agreement. As will be demonstrated in the chapters that follow, the controlled foreign company’s interest income is subjected to economic double taxation in terms of the scenario depicted in this treatise. This means that such income is taxed twice in the hands of two different taxpayers in two different States. As a result of this it is submitted that the following problem arises: Because section 9D of the Income Tax Act causes economic double taxation to occur (as illustrated in the previous paragraphs) and owing to the fact that the purpose of the double taxation agreement is the avoidance of economic double taxation, it can be shown that the section 9D domestic legislation conflicts with the terms of the double taxation agreement. This conflict is considered to be an area of concern because a contravention of the purpose of the double taxation agreement is regarded as a breach of the Contracting States’ international obligations in terms of the aforesaid agreement. It is further submitted that paragraph 23 of the OECD Commentary on article 1 and paragraph 14 of the OECD Commentary on article 7 are incorrect when they express the sentiment that domestic controlled foreign company legislation does not conflict with the provisions of the double taxation agreement. It is proposed that this be corrected to state the contrary.
- Full Text:
- Date Issued: 2014
- Authors: Froom, Natalie Marie
- Date: 2014
- Subjects: Taxation -- Law and legislation -- South Africa , Fiscal policy -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/3559 , vital:20442
- Description: The South African fiscal legislators have found it necessary to introduce anti-avoidance legislation which governs controlled foreign companies in order to counteract schemes devised by taxpayers where companies are established outside South Africa for the purpose of diverting income from the South African fiscal net. Whilst the enforcement of such legislation does have merit in that the intention behind the introduction of such domestic legislation is to prevent the erosion of the South African tax base, it is submitted that this does pose a problem from an international perspective. The objective of this treatise is to conduct a critical analysis of how compatible the South African fiscal legislation which governs controlled foreign companies is with the provisions of the double taxation agreement as prescribed in terms of the OECD Model Tax Convention (which was published in July 2010). In addition, the aim of this study is to deduce whether the purpose of the double taxation agreement is not only the avoidance of juridical double taxation but also that it addresses the avoidance of economic double taxation. This will assist in determining whether domestic controlled foreign company legislation (as embodied in section 9D of the Income Tax Act 58 of 1962) conflicts with the purpose of the double taxation agreement. By conducting an extensive research study and by depicting a certain scenario which addresses the issue at hand, the following is concluded: The tax treatment of the business profits generated by a controlled foreign company resident in a State outside South Africa and which have been generated from active business operating activities, is held to be in agreement with the provisions of the double taxation agreement. By contrast, the tax treatment of the controlled foreign company’s passive income in the form of interest income, is found not to correlate with the aforesaid agreement. As will be demonstrated in the chapters that follow, the controlled foreign company’s interest income is subjected to economic double taxation in terms of the scenario depicted in this treatise. This means that such income is taxed twice in the hands of two different taxpayers in two different States. As a result of this it is submitted that the following problem arises: Because section 9D of the Income Tax Act causes economic double taxation to occur (as illustrated in the previous paragraphs) and owing to the fact that the purpose of the double taxation agreement is the avoidance of economic double taxation, it can be shown that the section 9D domestic legislation conflicts with the terms of the double taxation agreement. This conflict is considered to be an area of concern because a contravention of the purpose of the double taxation agreement is regarded as a breach of the Contracting States’ international obligations in terms of the aforesaid agreement. It is further submitted that paragraph 23 of the OECD Commentary on article 1 and paragraph 14 of the OECD Commentary on article 7 are incorrect when they express the sentiment that domestic controlled foreign company legislation does not conflict with the provisions of the double taxation agreement. It is proposed that this be corrected to state the contrary.
- Full Text:
- Date Issued: 2014
Dreamscape and death : an analysis of three contemporary novels and a film
- Authors: Truter, Victoria Zea
- Date: 2014
- Subjects: Malouf, David, 1934- -- Criticism and interpretation , Warner, Alan -- Criticism and interpretation , McCarthy, Cormac, 1933- -- Criticism and interpretation , Linklater, Richard, 1960- -- Criticism and interpretation , Australian fiction -- History and criticism , American fiction -- History and criticism , English fiction -- History and criticism , Motion pictures, American -- History and criticism , Malouf, David, 1934- An imaginary life , Warner, Alan -- These demented lands , McCarthy, Cormac, 1933- -- Road , Linklater, Richard, 1960- -- Waking Life , Death in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2308 , http://hdl.handle.net/10962/d1012976
- Description: With its focus on the relationship between dreamscape and death, this study examines the possibility of indirectly experiencing – through writing and dreaming – that which cannot be directly experienced, namely death. In considering this possibility, the thesis engages at length with Maurice Blanchot's argument that death, being irrevocably absent and therefore unknowable, is not open to presentation or representation. After explicating certain of this thinker's theories on the ambiguous nature of literary and oneiric representation, and on the forfeiture of subjective agency that occurs in the moments of writing and dreaming, the study turns to an examination of the manner in which such issues are dealt with in selected dreamscapes. With reference to David Malouf's An Imaginary Life, Alan Warner's These Demented Lands, Cormac McCarthy's The Road, and Richard Linklater's Waking Life, the thesis explores the literary and cinematic representation of human attempts to define, resist, or control death through dreaming and writing about it. Ultimately, the study concludes that such attempts are necessarily inconclusive, and that it is only ever possible to represent death as a (mis)representation.
- Full Text:
- Date Issued: 2014
- Authors: Truter, Victoria Zea
- Date: 2014
- Subjects: Malouf, David, 1934- -- Criticism and interpretation , Warner, Alan -- Criticism and interpretation , McCarthy, Cormac, 1933- -- Criticism and interpretation , Linklater, Richard, 1960- -- Criticism and interpretation , Australian fiction -- History and criticism , American fiction -- History and criticism , English fiction -- History and criticism , Motion pictures, American -- History and criticism , Malouf, David, 1934- An imaginary life , Warner, Alan -- These demented lands , McCarthy, Cormac, 1933- -- Road , Linklater, Richard, 1960- -- Waking Life , Death in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2308 , http://hdl.handle.net/10962/d1012976
- Description: With its focus on the relationship between dreamscape and death, this study examines the possibility of indirectly experiencing – through writing and dreaming – that which cannot be directly experienced, namely death. In considering this possibility, the thesis engages at length with Maurice Blanchot's argument that death, being irrevocably absent and therefore unknowable, is not open to presentation or representation. After explicating certain of this thinker's theories on the ambiguous nature of literary and oneiric representation, and on the forfeiture of subjective agency that occurs in the moments of writing and dreaming, the study turns to an examination of the manner in which such issues are dealt with in selected dreamscapes. With reference to David Malouf's An Imaginary Life, Alan Warner's These Demented Lands, Cormac McCarthy's The Road, and Richard Linklater's Waking Life, the thesis explores the literary and cinematic representation of human attempts to define, resist, or control death through dreaming and writing about it. Ultimately, the study concludes that such attempts are necessarily inconclusive, and that it is only ever possible to represent death as a (mis)representation.
- Full Text:
- Date Issued: 2014