Diversified computational approaches for the identification of orthosteric drugs, allosteric modulators and unveiling drug resistance mechanisms: application to infectious diseases
- Authors: Boateng, Rita Afriyie
- Date: 2022-04-08
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/234173 , vital:50169
- Description: Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-04-08
- Authors: Boateng, Rita Afriyie
- Date: 2022-04-08
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/234173 , vital:50169
- Description: Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-04-08
Dynamics of charge movement in ∞-Al2O3:C,Mg using thermoluminescence phototransferred and optically stimulated luminescence
- Authors: Lontsi Sob, Aaron Joel
- Date: 2022-04-08
- Subjects: Thermoluminescence , Optically stimulated luminescence , Phototransfer , Deep traps , Phototransferred thermoluminescence (PTTL)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294607 , vital:57237 , DOI 10.21504/10962/294607
- Description: The dosimetric features of ∞-Al2O3:C,Mg have been investigated for unannealed and annealed samples. The unannealed sample is referred to as sample A whereas the samples annealed at 700, 900 and 1200°C for 15 minutes each are referred to as samples B, C and D respectively. A glow curve of unannealed ∞-Al2O3:C,Mg measured at 1°C/s after irradiation to 2.0 Gy consists of peaks at 43, 73, 164, 195, 246, 284, 336 and 374°C respectively. For sample B (annealed at 700°C), a glow curve measured at 1°C/s after irradiation to 3.0 Gy has peaks at 46, 76, 100, 170, 199, 290, 330 and 375°C whereas the glow curve of sample C (annealed at 900°C) recorded under the same conditions consists of peaks at 49, 80, 100, 174, 206, 235, 290, 335 and 375°C respectively. Sample D (annealed at 1200°C) is the most sensitive of the four samples. A glow curve of sample D measured at 1°C/s after irradiation to 0.2 Gy has peaks at 52, 82, 102, 174, 234, 288 and 384°C respectively. The peaks are labelled I-VIII in order of appearance. The 100°C peak, labelled IIa, is induced by annealing at or above 700°C. The dose response of these peaks was studied for doses within 0.1-8.2 Gy. The reported peaks follow first-order kinetics irrespective of annealing temperature. Peaks I-III of each sample are reproduced under phototransfer for preheating up to 400°C. For the unannealed sample, the reproduced peaks are labelled A1-A3 whereas for the annealed samples, they are labelled B1-B3, C1-C3 and D1-D3 respectively. The annealing-induced peak at 100°C is reproduced as B2a, C2a and D2a for samples B, C and D respectively. A PTTL peak labelled C2b or D2b is also observed near 140°C in samples C and D. In addition to these PTTL peaks, a PTTL peak corresponding to peak IV is also found for sample D and for the unannealed sample. As the corresponding conventional peaks, the PTTL peaks of each sample follow first-order kinetics. Peak I and its corresponding PTTL peak for each sample are unstable and fade to a minimal level after 300 s of storage time. On the other hand, peak II of each sample and its corresponding PTTL peak could still be observed with delay up to 5000 s. Peak III of the unannealed sample remains stable with storage time up to 48 hours. Irrespective of annealing, the trap corresponding to peak III is the most sensitive to optical stimulation. Time-dependent profiles of PTTL from unannealed and annealed ∞-Al2O3:C,Mg were also studied. The mathematical analysis of the PTTL time-response profiles is based on experimental results. The role of various electron traps in PTTL was determined by using pulse annealing and by monitoring the dependence of peak intensity on duration of illumination for peaks not removed by preheating. The presence and role of deep traps were further demonstrated with thermally assisted optically stimulated luminescence. For the unannealed sample, the activation energy for thermal assistance is 0.033 ± 0.001 eV and the activation energy for thermal i quenching is 1.043 ± 0.001 eV. For sample C, the activation energy for thermal assistance is 0.044 ± 0.003 eV whereas that for thermal quenching is 1.110 ± 0.006 eV. The values for the activation energy for thermal assistance are lower than those reported in literature. Only the values for the activation energy for thermal quenching are somewhat comparable to values reported elsewhere. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2022
- Full Text:
- Date Issued: 2022-04-08
- Authors: Lontsi Sob, Aaron Joel
- Date: 2022-04-08
- Subjects: Thermoluminescence , Optically stimulated luminescence , Phototransfer , Deep traps , Phototransferred thermoluminescence (PTTL)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294607 , vital:57237 , DOI 10.21504/10962/294607
- Description: The dosimetric features of ∞-Al2O3:C,Mg have been investigated for unannealed and annealed samples. The unannealed sample is referred to as sample A whereas the samples annealed at 700, 900 and 1200°C for 15 minutes each are referred to as samples B, C and D respectively. A glow curve of unannealed ∞-Al2O3:C,Mg measured at 1°C/s after irradiation to 2.0 Gy consists of peaks at 43, 73, 164, 195, 246, 284, 336 and 374°C respectively. For sample B (annealed at 700°C), a glow curve measured at 1°C/s after irradiation to 3.0 Gy has peaks at 46, 76, 100, 170, 199, 290, 330 and 375°C whereas the glow curve of sample C (annealed at 900°C) recorded under the same conditions consists of peaks at 49, 80, 100, 174, 206, 235, 290, 335 and 375°C respectively. Sample D (annealed at 1200°C) is the most sensitive of the four samples. A glow curve of sample D measured at 1°C/s after irradiation to 0.2 Gy has peaks at 52, 82, 102, 174, 234, 288 and 384°C respectively. The peaks are labelled I-VIII in order of appearance. The 100°C peak, labelled IIa, is induced by annealing at or above 700°C. The dose response of these peaks was studied for doses within 0.1-8.2 Gy. The reported peaks follow first-order kinetics irrespective of annealing temperature. Peaks I-III of each sample are reproduced under phototransfer for preheating up to 400°C. For the unannealed sample, the reproduced peaks are labelled A1-A3 whereas for the annealed samples, they are labelled B1-B3, C1-C3 and D1-D3 respectively. The annealing-induced peak at 100°C is reproduced as B2a, C2a and D2a for samples B, C and D respectively. A PTTL peak labelled C2b or D2b is also observed near 140°C in samples C and D. In addition to these PTTL peaks, a PTTL peak corresponding to peak IV is also found for sample D and for the unannealed sample. As the corresponding conventional peaks, the PTTL peaks of each sample follow first-order kinetics. Peak I and its corresponding PTTL peak for each sample are unstable and fade to a minimal level after 300 s of storage time. On the other hand, peak II of each sample and its corresponding PTTL peak could still be observed with delay up to 5000 s. Peak III of the unannealed sample remains stable with storage time up to 48 hours. Irrespective of annealing, the trap corresponding to peak III is the most sensitive to optical stimulation. Time-dependent profiles of PTTL from unannealed and annealed ∞-Al2O3:C,Mg were also studied. The mathematical analysis of the PTTL time-response profiles is based on experimental results. The role of various electron traps in PTTL was determined by using pulse annealing and by monitoring the dependence of peak intensity on duration of illumination for peaks not removed by preheating. The presence and role of deep traps were further demonstrated with thermally assisted optically stimulated luminescence. For the unannealed sample, the activation energy for thermal assistance is 0.033 ± 0.001 eV and the activation energy for thermal i quenching is 1.043 ± 0.001 eV. For sample C, the activation energy for thermal assistance is 0.044 ± 0.003 eV whereas that for thermal quenching is 1.110 ± 0.006 eV. The values for the activation energy for thermal assistance are lower than those reported in literature. Only the values for the activation energy for thermal quenching are somewhat comparable to values reported elsewhere. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2022
- Full Text:
- Date Issued: 2022-04-08
Inhibition of aluminium corrosion using phthalocyanines: Experimental and computational studies
- Authors: Nnaji, Nnaemeka Joshua
- Date: 2022-04-08
- Subjects: Aluminum Corrosion , Electrochemistry , Phthalocyanines , Corrosion and anti-corrosives , Protective coatings , Density functionals
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294643 , vital:57240 , DOI 10.21504/10962/294643
- Description: Metal deterioration over time is a process known as corrosion, an electrochemical process, which can occur by surface chemical actions on metals by its environment. Metal corrosion have great economic, security, and environmental consequences, and its control is a major research area in corrosion science. Amongst the different corrosion protecting approaches, the use of corrosion inhibitors and protective coatings have attracted enormous research interest in this area of scholasticism. This has necessitated the computational and electrochemical investigations of aluminium corrosion inhibitive potentials of some compounds in 1M HCl. Metal free (5_H2), ClGa(III) (5_Ga) and Co(II) (5_Co) tetrakis(4-acetamidophenoxy)phthalocyanines as well as Co(II) 2,9,16-tris(4-(tert-butyl)phenoxy)-23-(pyridin-4-yloxy)phthalocyanine (6) and Co(II) 2,9,16,24-tetrakis(4-(tert-butyl)phenoxy)phthalocyanine (7) were synthesized for the first time and studied for corrosion inhibition. The reported ClGa(III) tetrakis(benzo[d]thiazol-2-yl-thio)phthalocyaninine (1), ClGa(III) tetrakis(benzo[d]thiazol-2ylphenoxy)phthalocyanine (2), ClGa(III) tetrakis-4-(hexadecane-1,2-dioxyl)-bis(phthalocyanine) (3) and ClGa(III) tetrakis-4,4′-((4-(benzo[d]thiazol-2-yl)-1,2-bis(phenoxy)-bis(phthalocyanine) (4) were also employed for corrosion inhibition of Al in HCl. Corrosion inhibition measurements using electrochemical techniques showed that increased π conjugation caused (1) to (2) to outperform (1a) and (2a) respectively as aluminium corrosion inhibitors in 1.0 M hydrochloric acid. For similar reason, (4) outperformed 2. (1) and (2) were successfully electrodeposited onto aluminium for corrosion retardation in 1.0 M hydrochloric acid solution. Measurements obtained from electrochemical impedance spectroscopy gave corrosion inhibition efficiency values of 82% for 1 and 86% for 2 in 1.0 M hydrochloric acid solution and showed that electrodeposited phthalocyanines have enhanced aluminium corrosion retardation than when in solution. The use of reduced graphene oxide nanosheets (rGONS) alone as aluminium corrosion inhibitor is discouraged because of poor aluminium corrosion inhibition in 1M HCl. However, synergistic effects were observed when rGONS was mixed each with (4) and (3). (5_H2), (5_Ga) and (5_Co) decreased aluminium corrosion in 1M HCl and observation was that the heavier the atom the more decreased the protection and the free base performed best of the three. Studied tertbutylphenoxy-derived CoPcs (6 and 7) exhibited good aluminium corrosion inhibition properties in studied acidic solution and the unsymmetric CoPc (6) which has more heteroatoms, gave better performance. Quantum chemical calculations involved the use of density functional theoretical (DFT) approaches and gave results which corroborated with experimental findings. , Thesis (PhD) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-04-08
- Authors: Nnaji, Nnaemeka Joshua
- Date: 2022-04-08
- Subjects: Aluminum Corrosion , Electrochemistry , Phthalocyanines , Corrosion and anti-corrosives , Protective coatings , Density functionals
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294643 , vital:57240 , DOI 10.21504/10962/294643
- Description: Metal deterioration over time is a process known as corrosion, an electrochemical process, which can occur by surface chemical actions on metals by its environment. Metal corrosion have great economic, security, and environmental consequences, and its control is a major research area in corrosion science. Amongst the different corrosion protecting approaches, the use of corrosion inhibitors and protective coatings have attracted enormous research interest in this area of scholasticism. This has necessitated the computational and electrochemical investigations of aluminium corrosion inhibitive potentials of some compounds in 1M HCl. Metal free (5_H2), ClGa(III) (5_Ga) and Co(II) (5_Co) tetrakis(4-acetamidophenoxy)phthalocyanines as well as Co(II) 2,9,16-tris(4-(tert-butyl)phenoxy)-23-(pyridin-4-yloxy)phthalocyanine (6) and Co(II) 2,9,16,24-tetrakis(4-(tert-butyl)phenoxy)phthalocyanine (7) were synthesized for the first time and studied for corrosion inhibition. The reported ClGa(III) tetrakis(benzo[d]thiazol-2-yl-thio)phthalocyaninine (1), ClGa(III) tetrakis(benzo[d]thiazol-2ylphenoxy)phthalocyanine (2), ClGa(III) tetrakis-4-(hexadecane-1,2-dioxyl)-bis(phthalocyanine) (3) and ClGa(III) tetrakis-4,4′-((4-(benzo[d]thiazol-2-yl)-1,2-bis(phenoxy)-bis(phthalocyanine) (4) were also employed for corrosion inhibition of Al in HCl. Corrosion inhibition measurements using electrochemical techniques showed that increased π conjugation caused (1) to (2) to outperform (1a) and (2a) respectively as aluminium corrosion inhibitors in 1.0 M hydrochloric acid. For similar reason, (4) outperformed 2. (1) and (2) were successfully electrodeposited onto aluminium for corrosion retardation in 1.0 M hydrochloric acid solution. Measurements obtained from electrochemical impedance spectroscopy gave corrosion inhibition efficiency values of 82% for 1 and 86% for 2 in 1.0 M hydrochloric acid solution and showed that electrodeposited phthalocyanines have enhanced aluminium corrosion retardation than when in solution. The use of reduced graphene oxide nanosheets (rGONS) alone as aluminium corrosion inhibitor is discouraged because of poor aluminium corrosion inhibition in 1M HCl. However, synergistic effects were observed when rGONS was mixed each with (4) and (3). (5_H2), (5_Ga) and (5_Co) decreased aluminium corrosion in 1M HCl and observation was that the heavier the atom the more decreased the protection and the free base performed best of the three. Studied tertbutylphenoxy-derived CoPcs (6 and 7) exhibited good aluminium corrosion inhibition properties in studied acidic solution and the unsymmetric CoPc (6) which has more heteroatoms, gave better performance. Quantum chemical calculations involved the use of density functional theoretical (DFT) approaches and gave results which corroborated with experimental findings. , Thesis (PhD) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-04-08
Quantifying the impacts of cactus biological control agents in South Africa
- Authors: Mnqeta, Zezethu
- Date: 2022-04-08
- Subjects: Cactus Biological control South Africa , Noxious weeds South Africa , Invasive plants Biological control South Africa , Insects as biological pest control agents South Africa , Cochineal insect South Africa , Mealybugs South Africa , Agricultural productivity South Africa
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294631 , vital:57239 , DOI 10.21504/10962/294631
- Description: Invasive alien cacti are prominent weeds that threaten indigenous biodiversity and have a negative impact on agricultural productivity in South Africa. These plants are problematic because they form dense thickets that reduce the carrying capacity of rangelands; restrict the movement of livestock and wildlife thus reducing access to shade and water sources; and are directly harmful to livestock, wildlife and people due to their sharp spines. Biological control is the most effective, affordable and environmentally friendly method to control invasive alien cacti and minimize their negative impacts. Cochineal insects (Dactylopius spp.: Dactylopiidae) and the gall-forming mealybug, Hypogeococcus sp. (Pseudococcidae) are used as biological control agents for cacti. The agents are however poor dispersers, so mass-rearing and augmentative releases are required in order to establish the agents at sites where they are needed. This study aimed to evaluate the mass-rearing and release efforts of cactus biological control in South Africa, quantify the impact of the biological control agents on cactus plant populations through long-term monitoring, and assess the benefits accrued due to the biological control agents through the perceptions of land-users. An assessment of the effectiveness of the release effort for cactus biological control agents was conducted by comparing where biological control agents have been released with the known distribution of the target weeds. Only 26% of the quarter degree squares that are known to be occupied by invasive alien cacti have had biological control agents released in them. This indicated that the mass-rearing and release efforts in South Africa are inadequate and should be increased, especially in areas where few releases have been made and many cacti are present, such as the Limpopo Province. The impact of the biological control agents on cactus plant populations was assessed by monitoring agent densities, target plant densities and target plant reproductive outputs before and after releases. Plant biomass and reproductive output were reduced by biological control agents for three of the target weeds that were assessed, while the duration of the study was too short to measure reductions for the fourth target weed. Benefits to land-users were then quantified through a questionnaire survey. Land-users perceived biological control as an effective management option, with 81% of the land-users reporting that there was less invasive alien cactus after releasing biological control agents on their land. Forty-nine percent of the land-users believed that the negative impacts of the cactus had been reduced and that they benefited more from their land since control was achieved. Since land-users were only interviewed within four years of the releases being conducted, it is expected that the percentage of land-users who gained benefits from biological control will increase in future. Ninety-seven percent of the land-users stated that the agents were safe and had not fed on any other plants or had any detrimental impacts. These perceptions indicated that land-users regarded biological control as a safe and effective method of controlling invasive alien cacti. This study confirms that biological control is an effective and safe way of controlling invasive alien Cactaceae. It is also the first to assess some of the benefits that land-users have accrued due to biological control of cactus weeds. It is however evident that a greater mass-rearing and release effort is required for South Africa to get the maximum benefits possible from the use of the biological control agents for cactus weeds that are available in the country. , Izityalo ze-cactus ezisuka kwamanye amazwe zilukhula olubalaseleyo, olwenza ingxaki kwintlobo ngeentlobo zezityalo nezilwanyana kwaye ezizityalo zinefuthe neziphumo ezingalunganga kwimveliso yezolimo eMzantsi Afrika. Ezi zizityalo ziyingxaki kuba zenza amatyholo ashinyeneyo athi anciphise umthamo wokusebenzisa umhlaba: zinqanda ukuhamba nogkukhululekileyo kwemfuyo nezilwanyana zasendle ngokwenza oko zingakwazi ukufikelela emthuzini xa kutshisa nakwimithombo yamanzi yokusela; zikwayiyo nengozi kwimfuyo, izilwanyana zasendle kunye nabantu ngenxa yamave abukhali afumaneka kwezizityalo. Ukulawula nokwehliza ubunzini nezinga lemigcipheko yezizityalo, kusetyenziswa indlela ekuthiwa yi-biological control. Lendlela yeyona ndlela isebenza ngokuphucukileyo, efikelelayo, nengenabungozi kokusingqongileyo. Izinambuzane ze- cochineal (i-Dactylopius spp.: Dactylopiidae) kunye ne-mealybug, i-Hypogeococcus sp. (Pseudococcidae) zisetyenziswe njengezixhobo ze-biological control ezinceda ukulawula ezizityalo ze-cactus zingafunekiyo. Ingxaki yazo ezizinambuzane zizixhobo ze-biological control zingentla kukuba azikwazi kuzisasaza ngokwazo ukuba zifikelele nakwizityalo ezikude ngoko ke ukukhuliswa nokukhutshwa ngobuninzi bazo kuyafuneka ukukhawulelana nalengxaki kunye nokwandisa amathuba wokuba zifikelele kuzozonke izityalo ze-cactus ekufuneka zizilawule. Olu phononongo lujolise ekuvavanyeni iinzame zokukhulisa ngobuninzi nokukhupha ezezinambuzane zizixhobo ze-bioloigical control zokulawula izityalo ze-cactus eMzantsi Afrika, ukujonga ubungakanani befuthe notshintsho elenziwa zezinambuzane zizixhobo ze-bioloigical control kwizityalo ze-cactus emva kwexesha elide lokuzijonga, kunye nokuvavanya inzuzo efunyenwe ngenxa yokulawula ezizityalo ze-cactus ngokwemibono yabasebenzisi bomhlaba. Uvavanyo lweenzame zokukhutshwa kwezixhobo zezixhobo zezinambuzane ze-bioloigical control kwizityalo ze-cactus lwenziwa ngokuthelekisa iindawo apho izixhobo zezinambuzane ze-biological control zikhutshwe khona kunye neendawo apho izityalo ze-cactus kwaziwayo ukuba ziyafumaneka khona. Yi-26% kuphela yesikwere sekota eyaziwayo ukuba kukhona izityalo ze-cactus nalapho kukhutshwe khona kwezinambuzane ezizixhobo ze-biological control. Oku kubonisa ukuba iinzame zokukhulisa nokukhutshwa kwezinambuzane ezizixhobo ze-biological control eMzantsi Afrika azanelanga kwaye kufuneka zandiswe, ngakumbi kwiindawo apho kukho ukhutsho olumbalwa olwenziweyo kunye nezityalo ze-cactus ezininzi ezifumaneka khona, njengePhondo laseLimpopo. Iimpembelelo yokukhutshwa kwezinambuzane ezizixhobo ze-biological control kwizityalo ze-cactus zavavanywa ngokujonga ubunizi bezinambuzane ezizixhobo ze-biological control, ukuxinana kwezityalo ze-cactus ekujoliswe kuzo kunye nemveliso yokuzala kwezityalo ze-cactus phambi nasemva kokuba kukhutshwe izinambuzane ezizixhobo ze-biological control. Ubungakanani bezityalo ze-cactus kunye nemveliso yokuzala ziye zacutheka emva kokukhutshwa kwezinambuzane ezizixhobo ze-biological control kwinzityalo ezintathu ze-cactus ebekujoliswe uvavanyo kuzo, ngelixa ixesha lophononongo lalifutshane kakhulu ukuvavanya unciphiso kwisityalo se-cactus sesine. Izibonelelo zabasebenzisi bomhlaba zaye zavavanywa kusetyenziswa uhlobo lwemibuzo. Abasebenzisi bomhlaba balubona ukusetyenziswa kwezinambuzane ezizixhobo ze-biological control njengendlela yolawulo olusebenzayo, yi81% yabasebenzisi bomhlaba echaze ukuba izityalo ze-cactus zecuthekile emva kokukhutshwa kwezinambuzane ezizixhobo ze-biological control emhlabeni wabo. Amashumi amane anesithoba eepesenti zabasebenzisi bomhlaba bakholelwa ukuba impembelelo ezingalunganga ze-cactus zincitshisiwe kwaye baxhamle kakhulu kumhlaba wabo okoko lwaphunyenzwa. Oludliwano-ndlebe belwenziwe kubasebenzisi bomhlaba kwisithuba seminyaka emine emva kokuba kukhutshwe izinambuzane ezizixhobo ze-biological control, kulindeleke ukuba ipesenti yabasebenzisi bomhlaba abathe bafumana izibonelelo kwi-biological control lonyuke kwixesha elizayo. Amashumi alithoba anesixhenxe ekhulwini abasebenzisi bomhlaba bachaze ukuba izinambuzane ezizixhobo ze-biological control zikhuselekile kwaye khange zidle kuzo naziphi na ezinye izityalo ezingezi eze-cactus ebekujoliswe kuzo okanye zineempembelelo eyingozi. Ezi mbono ziyabonisa ukuba abasebenzi bomhlaba bayithatha i-biological control njengendlela ekhuselekileyo nesebenzayo yokulawula izityalo ze-cactus zamanye amazwe. Olu phononongo luqinisekisa ukuba ulawulo olusebenzisa izinambuzane ezizixhobo ze-biological control yindlela esebenzayo nekhuselekileyo yokulawula iCactaceae yamanye amazwe. Ikwangolokuqala ukuvavanya ezinye zezibonelelo ezizuzwe ngabasebenzisi bomhlaba ngenxa ye-biological control yezityalo ze-cactus. Nangona kunjalo kucacile ukuba ukwandisa inzame zokukhulisa nokukhupha ngobuninzi izinambuzane ezizixhobo ze-biological control kuyafuneka ukuze uMzantsi Afrika ufumane izibonelelo eziphakamileyo enokubakho ngokusetyenziswa kwe zinambuzane ezizixhobo ze-biological control zokulawula ukhula lwe-cactus olukhoyo kweli lizwe. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Date Issued: 2022-04-08
- Authors: Mnqeta, Zezethu
- Date: 2022-04-08
- Subjects: Cactus Biological control South Africa , Noxious weeds South Africa , Invasive plants Biological control South Africa , Insects as biological pest control agents South Africa , Cochineal insect South Africa , Mealybugs South Africa , Agricultural productivity South Africa
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294631 , vital:57239 , DOI 10.21504/10962/294631
- Description: Invasive alien cacti are prominent weeds that threaten indigenous biodiversity and have a negative impact on agricultural productivity in South Africa. These plants are problematic because they form dense thickets that reduce the carrying capacity of rangelands; restrict the movement of livestock and wildlife thus reducing access to shade and water sources; and are directly harmful to livestock, wildlife and people due to their sharp spines. Biological control is the most effective, affordable and environmentally friendly method to control invasive alien cacti and minimize their negative impacts. Cochineal insects (Dactylopius spp.: Dactylopiidae) and the gall-forming mealybug, Hypogeococcus sp. (Pseudococcidae) are used as biological control agents for cacti. The agents are however poor dispersers, so mass-rearing and augmentative releases are required in order to establish the agents at sites where they are needed. This study aimed to evaluate the mass-rearing and release efforts of cactus biological control in South Africa, quantify the impact of the biological control agents on cactus plant populations through long-term monitoring, and assess the benefits accrued due to the biological control agents through the perceptions of land-users. An assessment of the effectiveness of the release effort for cactus biological control agents was conducted by comparing where biological control agents have been released with the known distribution of the target weeds. Only 26% of the quarter degree squares that are known to be occupied by invasive alien cacti have had biological control agents released in them. This indicated that the mass-rearing and release efforts in South Africa are inadequate and should be increased, especially in areas where few releases have been made and many cacti are present, such as the Limpopo Province. The impact of the biological control agents on cactus plant populations was assessed by monitoring agent densities, target plant densities and target plant reproductive outputs before and after releases. Plant biomass and reproductive output were reduced by biological control agents for three of the target weeds that were assessed, while the duration of the study was too short to measure reductions for the fourth target weed. Benefits to land-users were then quantified through a questionnaire survey. Land-users perceived biological control as an effective management option, with 81% of the land-users reporting that there was less invasive alien cactus after releasing biological control agents on their land. Forty-nine percent of the land-users believed that the negative impacts of the cactus had been reduced and that they benefited more from their land since control was achieved. Since land-users were only interviewed within four years of the releases being conducted, it is expected that the percentage of land-users who gained benefits from biological control will increase in future. Ninety-seven percent of the land-users stated that the agents were safe and had not fed on any other plants or had any detrimental impacts. These perceptions indicated that land-users regarded biological control as a safe and effective method of controlling invasive alien cacti. This study confirms that biological control is an effective and safe way of controlling invasive alien Cactaceae. It is also the first to assess some of the benefits that land-users have accrued due to biological control of cactus weeds. It is however evident that a greater mass-rearing and release effort is required for South Africa to get the maximum benefits possible from the use of the biological control agents for cactus weeds that are available in the country. , Izityalo ze-cactus ezisuka kwamanye amazwe zilukhula olubalaseleyo, olwenza ingxaki kwintlobo ngeentlobo zezityalo nezilwanyana kwaye ezizityalo zinefuthe neziphumo ezingalunganga kwimveliso yezolimo eMzantsi Afrika. Ezi zizityalo ziyingxaki kuba zenza amatyholo ashinyeneyo athi anciphise umthamo wokusebenzisa umhlaba: zinqanda ukuhamba nogkukhululekileyo kwemfuyo nezilwanyana zasendle ngokwenza oko zingakwazi ukufikelela emthuzini xa kutshisa nakwimithombo yamanzi yokusela; zikwayiyo nengozi kwimfuyo, izilwanyana zasendle kunye nabantu ngenxa yamave abukhali afumaneka kwezizityalo. Ukulawula nokwehliza ubunzini nezinga lemigcipheko yezizityalo, kusetyenziswa indlela ekuthiwa yi-biological control. Lendlela yeyona ndlela isebenza ngokuphucukileyo, efikelelayo, nengenabungozi kokusingqongileyo. Izinambuzane ze- cochineal (i-Dactylopius spp.: Dactylopiidae) kunye ne-mealybug, i-Hypogeococcus sp. (Pseudococcidae) zisetyenziswe njengezixhobo ze-biological control ezinceda ukulawula ezizityalo ze-cactus zingafunekiyo. Ingxaki yazo ezizinambuzane zizixhobo ze-biological control zingentla kukuba azikwazi kuzisasaza ngokwazo ukuba zifikelele nakwizityalo ezikude ngoko ke ukukhuliswa nokukhutshwa ngobuninzi bazo kuyafuneka ukukhawulelana nalengxaki kunye nokwandisa amathuba wokuba zifikelele kuzozonke izityalo ze-cactus ekufuneka zizilawule. Olu phononongo lujolise ekuvavanyeni iinzame zokukhulisa ngobuninzi nokukhupha ezezinambuzane zizixhobo ze-bioloigical control zokulawula izityalo ze-cactus eMzantsi Afrika, ukujonga ubungakanani befuthe notshintsho elenziwa zezinambuzane zizixhobo ze-bioloigical control kwizityalo ze-cactus emva kwexesha elide lokuzijonga, kunye nokuvavanya inzuzo efunyenwe ngenxa yokulawula ezizityalo ze-cactus ngokwemibono yabasebenzisi bomhlaba. Uvavanyo lweenzame zokukhutshwa kwezixhobo zezixhobo zezinambuzane ze-bioloigical control kwizityalo ze-cactus lwenziwa ngokuthelekisa iindawo apho izixhobo zezinambuzane ze-biological control zikhutshwe khona kunye neendawo apho izityalo ze-cactus kwaziwayo ukuba ziyafumaneka khona. Yi-26% kuphela yesikwere sekota eyaziwayo ukuba kukhona izityalo ze-cactus nalapho kukhutshwe khona kwezinambuzane ezizixhobo ze-biological control. Oku kubonisa ukuba iinzame zokukhulisa nokukhutshwa kwezinambuzane ezizixhobo ze-biological control eMzantsi Afrika azanelanga kwaye kufuneka zandiswe, ngakumbi kwiindawo apho kukho ukhutsho olumbalwa olwenziweyo kunye nezityalo ze-cactus ezininzi ezifumaneka khona, njengePhondo laseLimpopo. Iimpembelelo yokukhutshwa kwezinambuzane ezizixhobo ze-biological control kwizityalo ze-cactus zavavanywa ngokujonga ubunizi bezinambuzane ezizixhobo ze-biological control, ukuxinana kwezityalo ze-cactus ekujoliswe kuzo kunye nemveliso yokuzala kwezityalo ze-cactus phambi nasemva kokuba kukhutshwe izinambuzane ezizixhobo ze-biological control. Ubungakanani bezityalo ze-cactus kunye nemveliso yokuzala ziye zacutheka emva kokukhutshwa kwezinambuzane ezizixhobo ze-biological control kwinzityalo ezintathu ze-cactus ebekujoliswe uvavanyo kuzo, ngelixa ixesha lophononongo lalifutshane kakhulu ukuvavanya unciphiso kwisityalo se-cactus sesine. Izibonelelo zabasebenzisi bomhlaba zaye zavavanywa kusetyenziswa uhlobo lwemibuzo. Abasebenzisi bomhlaba balubona ukusetyenziswa kwezinambuzane ezizixhobo ze-biological control njengendlela yolawulo olusebenzayo, yi81% yabasebenzisi bomhlaba echaze ukuba izityalo ze-cactus zecuthekile emva kokukhutshwa kwezinambuzane ezizixhobo ze-biological control emhlabeni wabo. Amashumi amane anesithoba eepesenti zabasebenzisi bomhlaba bakholelwa ukuba impembelelo ezingalunganga ze-cactus zincitshisiwe kwaye baxhamle kakhulu kumhlaba wabo okoko lwaphunyenzwa. Oludliwano-ndlebe belwenziwe kubasebenzisi bomhlaba kwisithuba seminyaka emine emva kokuba kukhutshwe izinambuzane ezizixhobo ze-biological control, kulindeleke ukuba ipesenti yabasebenzisi bomhlaba abathe bafumana izibonelelo kwi-biological control lonyuke kwixesha elizayo. Amashumi alithoba anesixhenxe ekhulwini abasebenzisi bomhlaba bachaze ukuba izinambuzane ezizixhobo ze-biological control zikhuselekile kwaye khange zidle kuzo naziphi na ezinye izityalo ezingezi eze-cactus ebekujoliswe kuzo okanye zineempembelelo eyingozi. Ezi mbono ziyabonisa ukuba abasebenzi bomhlaba bayithatha i-biological control njengendlela ekhuselekileyo nesebenzayo yokulawula izityalo ze-cactus zamanye amazwe. Olu phononongo luqinisekisa ukuba ulawulo olusebenzisa izinambuzane ezizixhobo ze-biological control yindlela esebenzayo nekhuselekileyo yokulawula iCactaceae yamanye amazwe. Ikwangolokuqala ukuvavanya ezinye zezibonelelo ezizuzwe ngabasebenzisi bomhlaba ngenxa ye-biological control yezityalo ze-cactus. Nangona kunjalo kucacile ukuba ukwandisa inzame zokukhulisa nokukhupha ngobuninzi izinambuzane ezizixhobo ze-biological control kuyafuneka ukuze uMzantsi Afrika ufumane izibonelelo eziphakamileyo enokubakho ngokusetyenziswa kwe zinambuzane ezizixhobo ze-biological control zokulawula ukhula lwe-cactus olukhoyo kweli lizwe. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Date Issued: 2022-04-08
Singlet oxygen and optical limiting applications of BODIPYs and other molecular dyes
- Authors: May, Aviwe Khanya
- Date: 2022-04-08
- Subjects: Dyes and dyeing Chemistry , Phthalocyanines , Photochemotherapy , Active oxygen , Nonlinear optics , Time-dependent density functional theory , Photochemistry
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294618 , vital:57238 , DOI 10.21504/10962/294620
- Description: A series of structurally diverse novel and previously synthesized BODIPY core dyes are synthesized and characterized in this thesis. These BODIPYs were synthesized using 2-methylpyrrole, 2-ethylpyrrole, 2,4-dimethylpyrrole and 3-ethyl-2,4-dimethylpyrrole as the starting pyrroles. The combination of different pyrroles with the same aldehyde results in BODIPY core dyes that are structural analogues. These core dyes were used as precursors to synthesise halogenated BODIPYs and novel styrylBODIPY dyes, which were successfully characterized using FT-IR and 1H NMR spectroscopy. The halogenated BODIPY core dyes and the styrylBODIPY dyes were also characterized using MALDI-TOF mass spectrometry. The introduction of heavy atoms on the BODIPY core leads to a red shift of the main spectral. In the presence of styryl groups, the main spectral band red shifts to the far red end of the visible region. As expected, the halogenated BODIPY core dyes also had moderate singlet oxygen quantum yields. These halogenated core dyes were found to be suitable as photosensitizers as all the dyes reduced bacterial viability to below 50% during photodynamic antimicrobial chemotherapy (PACT) studies against Staphylococcus aureus. The structure-property relationships studied demonstrate that the presence of protons rather than methyls at the 1,7-positions or iodines at the 2,6-positions results in more favorable PACT activity. This is likely to be related to the greater ability of the meso-aryl to rotate into the plane of the dipyrromethene ligand and suggests that there should be a stronger focus on dyes of this type in future studies in this field. During nonlinear optical (NLO) studies, all the styrylBODIPYs exhibited favorable reverse saturable absorption (RSA) responses. In the absence of methyl groups at the 1,7-positions, the meso-aryl ring lies closer to the π-system of the BODIPY core, enhancing donor (D)–π–acceptor (A) properties and resulting in slightly enhanced optical limiting (OL) parameters. Additionally, there is no evidence that the introduction of heavy atoms at the 2,6-positions significantly enhances OL properties. In a similar manner, alkyl substituents at these positions also do not significantly enhance OL properties; this was studied for the first time using 15 with ethyl groups at the 2,6-positions. The combination of z-scan data and transient spectroscopy for 16 demonstrated that the main mechanism responsible for the NLO properties of nonhalogenated BODIPY dyes is one-photon absorption from the ground state followed by ESA in the singlet manifold. From the NLO studies of 25, OL parameters of 1,3,5-tristyrylBODIPY dyes were found to be similar in magnitude to properties of distyrylBODIPY dyes, but to have less favorable optical properties for OL applications. The OL properties of scandium phthalocyanines were assessed for the first time, since the Sc(III) ion, unusually for a first row transition metal ion, is known to readily form sandwich complexes. The presence of a Sc(III) ion does not significantly enhance the OL properties of phthalocyanines relative to those of rare earth metal ions that also form complexes of this type. Because BODIPYs and phthalocyanines typically absorb significantly in the visible region, transparent PBC polymer thin films of disilane-bridged compounds with minimal absorption in this region were studied and exhibited an excellent RSA response. These compounds may be useful in the design of OL materials that can protect the human eye. The optimized geometries and spectroscopic properties of selected BODIPYs were studied. As expected, the presence of bromine, iodine, ethyl and styryl groups at different positions of the BODIPY core leads to a narrowing of the HOMO–LUMO band gap, which results in a red-shift of the main spectral band. Partial atomic charges have also been calculated for some of the styrylBODIPY dyes studied for application in OL, and electrostatic potential energy maps were also visualized to better assess how the dipole moment of BODIPY dyes can be modulated since this can affect the OL properties. For all the BODIPYs studied, the electronegativity of the atoms present influences charge distribution on the BODIPY structure. , Thesis (PhD) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-04-08
- Authors: May, Aviwe Khanya
- Date: 2022-04-08
- Subjects: Dyes and dyeing Chemistry , Phthalocyanines , Photochemotherapy , Active oxygen , Nonlinear optics , Time-dependent density functional theory , Photochemistry
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294618 , vital:57238 , DOI 10.21504/10962/294620
- Description: A series of structurally diverse novel and previously synthesized BODIPY core dyes are synthesized and characterized in this thesis. These BODIPYs were synthesized using 2-methylpyrrole, 2-ethylpyrrole, 2,4-dimethylpyrrole and 3-ethyl-2,4-dimethylpyrrole as the starting pyrroles. The combination of different pyrroles with the same aldehyde results in BODIPY core dyes that are structural analogues. These core dyes were used as precursors to synthesise halogenated BODIPYs and novel styrylBODIPY dyes, which were successfully characterized using FT-IR and 1H NMR spectroscopy. The halogenated BODIPY core dyes and the styrylBODIPY dyes were also characterized using MALDI-TOF mass spectrometry. The introduction of heavy atoms on the BODIPY core leads to a red shift of the main spectral. In the presence of styryl groups, the main spectral band red shifts to the far red end of the visible region. As expected, the halogenated BODIPY core dyes also had moderate singlet oxygen quantum yields. These halogenated core dyes were found to be suitable as photosensitizers as all the dyes reduced bacterial viability to below 50% during photodynamic antimicrobial chemotherapy (PACT) studies against Staphylococcus aureus. The structure-property relationships studied demonstrate that the presence of protons rather than methyls at the 1,7-positions or iodines at the 2,6-positions results in more favorable PACT activity. This is likely to be related to the greater ability of the meso-aryl to rotate into the plane of the dipyrromethene ligand and suggests that there should be a stronger focus on dyes of this type in future studies in this field. During nonlinear optical (NLO) studies, all the styrylBODIPYs exhibited favorable reverse saturable absorption (RSA) responses. In the absence of methyl groups at the 1,7-positions, the meso-aryl ring lies closer to the π-system of the BODIPY core, enhancing donor (D)–π–acceptor (A) properties and resulting in slightly enhanced optical limiting (OL) parameters. Additionally, there is no evidence that the introduction of heavy atoms at the 2,6-positions significantly enhances OL properties. In a similar manner, alkyl substituents at these positions also do not significantly enhance OL properties; this was studied for the first time using 15 with ethyl groups at the 2,6-positions. The combination of z-scan data and transient spectroscopy for 16 demonstrated that the main mechanism responsible for the NLO properties of nonhalogenated BODIPY dyes is one-photon absorption from the ground state followed by ESA in the singlet manifold. From the NLO studies of 25, OL parameters of 1,3,5-tristyrylBODIPY dyes were found to be similar in magnitude to properties of distyrylBODIPY dyes, but to have less favorable optical properties for OL applications. The OL properties of scandium phthalocyanines were assessed for the first time, since the Sc(III) ion, unusually for a first row transition metal ion, is known to readily form sandwich complexes. The presence of a Sc(III) ion does not significantly enhance the OL properties of phthalocyanines relative to those of rare earth metal ions that also form complexes of this type. Because BODIPYs and phthalocyanines typically absorb significantly in the visible region, transparent PBC polymer thin films of disilane-bridged compounds with minimal absorption in this region were studied and exhibited an excellent RSA response. These compounds may be useful in the design of OL materials that can protect the human eye. The optimized geometries and spectroscopic properties of selected BODIPYs were studied. As expected, the presence of bromine, iodine, ethyl and styryl groups at different positions of the BODIPY core leads to a narrowing of the HOMO–LUMO band gap, which results in a red-shift of the main spectral band. Partial atomic charges have also been calculated for some of the styrylBODIPY dyes studied for application in OL, and electrostatic potential energy maps were also visualized to better assess how the dipole moment of BODIPY dyes can be modulated since this can affect the OL properties. For all the BODIPYs studied, the electronegativity of the atoms present influences charge distribution on the BODIPY structure. , Thesis (PhD) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-04-08
Synthesis and evaluation of the medicinal potential of novel 4-hydroxycoumarin derivatives
- Authors: Manyeruke, Meloddy Hlatini
- Date: 2022-04-08
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/164458 , vital:41120 , doi:10.21504/10962/164458
- Description: This research has focused on the synthesis and biological evaluation of a broad range of compounds characterised by the presence of the pharmacologically significant 4-hydroxycoumalin scaffold. The compounds were designed to contain additional pharmachophoric centres to enhance bioactivity and generate lead compounds with dualaction potential. The use of 4-hydroxycoumarin as the primary synthon enabled access to various series of 4-hydroxycoumarin conjugates, the reactive 3-position on the 4-hydroxycoumarin moiety being exploited for regioselective construction of the targeted compounds in several steps. Some of the reactants required in the construction of these compounds were specially synthesised and included propargyloxy benzaldehydes, benzyloxy benzaldehydes and 2,3-dihydroxysuccino-dihydride. Overall, eight different families of novel compounds were accessed, comprising conjugates of 4-hydroxycoumarin with bisethylidenesuccinohyrazide, trifluoroacetamide, amino, benzyloxyphenyl-iminoethyl, benzylidenehyrazinyl-thiazoyl, benzylidenehydrazonoethyl, propargyloxybenzylidenehydrazonoethyl and phenylacryloyl moieties using protocols that required minimal work-up and purification. The eighty novel compounds synthesised in the study were fully characterised using HMRS and advanced NMR techniques. Cytotoxicity, HIV-1 IN and PR inhibitory, and antitrypanosomal, antimalarial and anti-Mtb assays were conducted on the synthesised coumarin derivatives. Several compounds exhibited activity against HIV-1 IN, the most potent being a bis-ethylidenesuccinohyrazide with an IC50 value of 3.5 μM. Various compounds exhibited anti-malarial activity (% pLDH viability in the range 62-77%), anti-trypanosomal activity (the most potent with an IC50 = 0.9 μM against T.b. brucei) and a measure of anti-Mtb activity. Apart from two chalconyl derivatives, none of the synthesised compounds exhibited significant cytotoxicity. Conflicting results were obtained from the in silico docking studies; in some cases supporting the observed in vitro assay data while, in others, exhibiting no correlation. , Thesis (PhD) -- Faculty of Science, Chemistry, 2020
- Full Text:
- Date Issued: 2022-04-08
- Authors: Manyeruke, Meloddy Hlatini
- Date: 2022-04-08
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/164458 , vital:41120 , doi:10.21504/10962/164458
- Description: This research has focused on the synthesis and biological evaluation of a broad range of compounds characterised by the presence of the pharmacologically significant 4-hydroxycoumalin scaffold. The compounds were designed to contain additional pharmachophoric centres to enhance bioactivity and generate lead compounds with dualaction potential. The use of 4-hydroxycoumarin as the primary synthon enabled access to various series of 4-hydroxycoumarin conjugates, the reactive 3-position on the 4-hydroxycoumarin moiety being exploited for regioselective construction of the targeted compounds in several steps. Some of the reactants required in the construction of these compounds were specially synthesised and included propargyloxy benzaldehydes, benzyloxy benzaldehydes and 2,3-dihydroxysuccino-dihydride. Overall, eight different families of novel compounds were accessed, comprising conjugates of 4-hydroxycoumarin with bisethylidenesuccinohyrazide, trifluoroacetamide, amino, benzyloxyphenyl-iminoethyl, benzylidenehyrazinyl-thiazoyl, benzylidenehydrazonoethyl, propargyloxybenzylidenehydrazonoethyl and phenylacryloyl moieties using protocols that required minimal work-up and purification. The eighty novel compounds synthesised in the study were fully characterised using HMRS and advanced NMR techniques. Cytotoxicity, HIV-1 IN and PR inhibitory, and antitrypanosomal, antimalarial and anti-Mtb assays were conducted on the synthesised coumarin derivatives. Several compounds exhibited activity against HIV-1 IN, the most potent being a bis-ethylidenesuccinohyrazide with an IC50 value of 3.5 μM. Various compounds exhibited anti-malarial activity (% pLDH viability in the range 62-77%), anti-trypanosomal activity (the most potent with an IC50 = 0.9 μM against T.b. brucei) and a measure of anti-Mtb activity. Apart from two chalconyl derivatives, none of the synthesised compounds exhibited significant cytotoxicity. Conflicting results were obtained from the in silico docking studies; in some cases supporting the observed in vitro assay data while, in others, exhibiting no correlation. , Thesis (PhD) -- Faculty of Science, Chemistry, 2020
- Full Text:
- Date Issued: 2022-04-08
The role of angling-guides in promoting pro-environmental catch-and-release attitudes and behaviours in the recreational angling community
- Authors: Farthing, Matthew William
- Date: 2022-04-08
- Subjects: Fishing , Fishing Catch effort , Fishing guides , Fishers , Human behavior , Role models
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294583 , vital:57235 , DOI 10.21504/10962/294585
- Description: Angling-guides are respected as opinion leaders of the recreational angling community, but nothing is known of their influence on angler behaviour. Given their social-standing, angling-guides may be perceived as role-models by angling-clients – thereby promoting the adoption of best and/or poor catch-and-release (C&R) practices, depending on their individual knowledge, attitudes and behaviour. It is critical to understand their potential influence, their knowledge and their behaviours to inform effective intervention strategies which could exploit their extensive networking potential. The aim of this thesis was to better understand the potential utility of angling-guides in efforts to improve angler behaviour. Firstly, this was done by investigating whether angling-guides are perceived as role-models by angling-clients (Chapter 2). Secondly, it was done by assessing the current level of knowledge, attitudes and behaviours of angling-guides from around the world (Chapter 3). Thirdly, it was done by exploring the relationship between angling-guide knowledge, attitudes, intentions and actual behaviour in a case-study of guided-angling trips (Chapter 4). Lastly, it was done by exploring intervention frameworks and incorporating insights into potential strategies for promoting pro-environmental angling behaviours to angling-guides (Chapter 5). To understand if angling-guides are perceived as role-models by the recreational angling community (Chapter 2), a digital survey was designed to assess previous angling-clients’ attitudes towards angling-guides serving the three role-model functions proposed in the Motivational Theory of Role-Modelling, namely as Behavioural models, Representations of the Possible and Inspiration. Of the 492 angling-clients (27 countries), most agreed that angling-guides were competent, skilled, and worth emulating (91.1%), suggesting they are perceived as Behavioural Models. Less agreed that angling-guides were Inspirational or Representations of the Possible (54.8%), suggesting they are less likely to motivate anglers to adopt and/or pursue new goals. As Behavioural Models, angling-guide C&R practices are likely to be emulated, which is of both utility and concern to managers. As angling-guides are likely to be emulated, a digital survey was designed to assess their knowledge, attitudes and behaviours (particularly C&R best-practices) (Chapter 3). Of the 342 angling-guides (47 countries), few had accredited training (9.4%). However, most were deemed “knowledgeable of best-practices” (69.0%), but pervasive misconceptions of key C&R best-practices were observed. Attitudes towards best-practices were generally pro-environmental, and those deemed knowledgeable had significantly more pro-environmental attitudes (p = 0.003). Most angling-guides had pro-environmental attitudes towards their environmental responsibilities (87.1 - 89.5%), but these broad attitudes cannot predict specific pro-environmental behaviours during guided-angling trips where angler satisfaction is often at odds with best-practice. Angling-client satisfaction has important financial implications for angling-guides, and even those with pro-environmental intentions may struggle to adhere to C&R best-practices with inherent sacrifices for the angling-client’s enjoyment. Observation of behaviour in context is critical for understanding the behaviour to be changed. To explore the relationship between angling-guide knowledge, intentions and actual behaviour (Chapter 4), five angling-guides were observed (and filmed) interacting with groups of angling-clients during their guided-angling trips over a 30 day period. Five angling behaviours of interest were identified, and a survey focussed on these behaviours was disseminated (18 months later) to the five angling-guides previously observed to assess their knowledge, attitudes, reported behaviours and perceptions of the norm. Generally the subjects’ reported behaviours aligned well with their knowledge of best-practice, but their actual behaviour was not well aligned (24.4%). Instead, their actual behaviour aligned better with their perceptions of the norm (80.9%), which was generally a “worse” practice than what they reported. Angling-guides appeared to favour client-satisfaction over pro-environmental behaviour. Gaps between angling-guides’ knowledge of best-practice and their actual behaviour indicate that there may be obscure and complex barriers to pro-environmental angling-guide behaviour. Many barriers are seemingly impossible to overcome, such as economic limitations and financial disincentives. These barriers may limit the efficacy of traditional knowledge-attitude-behaviour (KAB) change interventions. The strong alignment of angling-guide behaviour with social norms, and the strong community orientation of recreational angling suggests that the Community-Based Social Marketing (CBSM) approach may be a more effective framework for interventions that aim to promote pro-environmental catch-and-release behaviours at angling-guide level. The CBSM approach allows interventionists to leverage a larger suite of cognitive biases than KAB approaches, provided that sufficient understanding of the context, barriers and benefits for a given segment of the angling-guide community (likely defined by style-of-participation) are obtained. Furthermore, the success of the CBSM approach will depend on the ability of interventionists to effectively recruit and incentivise disjunct and isolated communities of angling-guides to participate in training and workshops in order to achieve the important in-person contact on which the CBSM approach depends. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-04-08
- Authors: Farthing, Matthew William
- Date: 2022-04-08
- Subjects: Fishing , Fishing Catch effort , Fishing guides , Fishers , Human behavior , Role models
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294583 , vital:57235 , DOI 10.21504/10962/294585
- Description: Angling-guides are respected as opinion leaders of the recreational angling community, but nothing is known of their influence on angler behaviour. Given their social-standing, angling-guides may be perceived as role-models by angling-clients – thereby promoting the adoption of best and/or poor catch-and-release (C&R) practices, depending on their individual knowledge, attitudes and behaviour. It is critical to understand their potential influence, their knowledge and their behaviours to inform effective intervention strategies which could exploit their extensive networking potential. The aim of this thesis was to better understand the potential utility of angling-guides in efforts to improve angler behaviour. Firstly, this was done by investigating whether angling-guides are perceived as role-models by angling-clients (Chapter 2). Secondly, it was done by assessing the current level of knowledge, attitudes and behaviours of angling-guides from around the world (Chapter 3). Thirdly, it was done by exploring the relationship between angling-guide knowledge, attitudes, intentions and actual behaviour in a case-study of guided-angling trips (Chapter 4). Lastly, it was done by exploring intervention frameworks and incorporating insights into potential strategies for promoting pro-environmental angling behaviours to angling-guides (Chapter 5). To understand if angling-guides are perceived as role-models by the recreational angling community (Chapter 2), a digital survey was designed to assess previous angling-clients’ attitudes towards angling-guides serving the three role-model functions proposed in the Motivational Theory of Role-Modelling, namely as Behavioural models, Representations of the Possible and Inspiration. Of the 492 angling-clients (27 countries), most agreed that angling-guides were competent, skilled, and worth emulating (91.1%), suggesting they are perceived as Behavioural Models. Less agreed that angling-guides were Inspirational or Representations of the Possible (54.8%), suggesting they are less likely to motivate anglers to adopt and/or pursue new goals. As Behavioural Models, angling-guide C&R practices are likely to be emulated, which is of both utility and concern to managers. As angling-guides are likely to be emulated, a digital survey was designed to assess their knowledge, attitudes and behaviours (particularly C&R best-practices) (Chapter 3). Of the 342 angling-guides (47 countries), few had accredited training (9.4%). However, most were deemed “knowledgeable of best-practices” (69.0%), but pervasive misconceptions of key C&R best-practices were observed. Attitudes towards best-practices were generally pro-environmental, and those deemed knowledgeable had significantly more pro-environmental attitudes (p = 0.003). Most angling-guides had pro-environmental attitudes towards their environmental responsibilities (87.1 - 89.5%), but these broad attitudes cannot predict specific pro-environmental behaviours during guided-angling trips where angler satisfaction is often at odds with best-practice. Angling-client satisfaction has important financial implications for angling-guides, and even those with pro-environmental intentions may struggle to adhere to C&R best-practices with inherent sacrifices for the angling-client’s enjoyment. Observation of behaviour in context is critical for understanding the behaviour to be changed. To explore the relationship between angling-guide knowledge, intentions and actual behaviour (Chapter 4), five angling-guides were observed (and filmed) interacting with groups of angling-clients during their guided-angling trips over a 30 day period. Five angling behaviours of interest were identified, and a survey focussed on these behaviours was disseminated (18 months later) to the five angling-guides previously observed to assess their knowledge, attitudes, reported behaviours and perceptions of the norm. Generally the subjects’ reported behaviours aligned well with their knowledge of best-practice, but their actual behaviour was not well aligned (24.4%). Instead, their actual behaviour aligned better with their perceptions of the norm (80.9%), which was generally a “worse” practice than what they reported. Angling-guides appeared to favour client-satisfaction over pro-environmental behaviour. Gaps between angling-guides’ knowledge of best-practice and their actual behaviour indicate that there may be obscure and complex barriers to pro-environmental angling-guide behaviour. Many barriers are seemingly impossible to overcome, such as economic limitations and financial disincentives. These barriers may limit the efficacy of traditional knowledge-attitude-behaviour (KAB) change interventions. The strong alignment of angling-guide behaviour with social norms, and the strong community orientation of recreational angling suggests that the Community-Based Social Marketing (CBSM) approach may be a more effective framework for interventions that aim to promote pro-environmental catch-and-release behaviours at angling-guide level. The CBSM approach allows interventionists to leverage a larger suite of cognitive biases than KAB approaches, provided that sufficient understanding of the context, barriers and benefits for a given segment of the angling-guide community (likely defined by style-of-participation) are obtained. Furthermore, the success of the CBSM approach will depend on the ability of interventionists to effectively recruit and incentivise disjunct and isolated communities of angling-guides to participate in training and workshops in order to achieve the important in-person contact on which the CBSM approach depends. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-04-08
The transformative potential of intersecting arts-based inquiry and environmental learning in urban South Africa: a focus on socio-ecological water pedagogies
- Authors: James, Anna Katharine
- Date: 2022-04-08
- Subjects: Environmental education South Africa , Water conservation Study and teaching South Africa , Art in environmental education South Africa , Social learning South Africa , Educational sociology South Africa , Water-supply Social aspects South Africa , Critical realism , Socio-ecological education
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/290660 , vital:56772 , DOI 10.21504/10962/290660
- Description: In this study I explore and explain transformative potential in arts-based environmental learning with a focus on water pedagogy. The study took place over a period of four years, where approximately 40 school pupils between the ages of 10 and 17 years-old were engaged in participatory arts-based inquiries into water located across unequal neighbourhoods in Cape Town, South Africa. Educators, school learners, citizens and decision-makers hold different historical, cultural, political and spiritual perspectives on water. These play a role in shaping what is termed in this research the ‘hydro-social cycle’. Yet, due to dominant ideas of what counts as knowing and truth, educators in educational settings struggle to account for the complexity of water, limiting educational encounters to a partial knowing leading mostly to limited unimaginative framings of problems and solutions. My focus on transformative potential in learning is derived from a concern for how environmental education encounters and the sense-making they enable, are infused by socio-economic, political, and historical elements, specifically colonialism, capitalism, and white supremacist racism. The connections between the multiple layers of capitalist crisis and the ever-urgent environmental crisis are not adequately made in mainstream forms of water education. The research explores how arts-based pedagogy could enable a productive meeting of critical environmental education with ecological literacies. Within this positioning, transformative potential considers how educational engagements position questions about water within the social life of participants/learners and inform learning that leads to fuller and more nuanced greater knowledge. Theoretically, I work with an interrogation of critical education theory, underlaboured by critical realism which enabled me to rigorously consider how claims to knowing are shaped by their accompanying assumptions of what is real. Drawing on recent debates in critical education theory, I resist the notion of critique as ideology and engage instead in the craftsmanship of contextual and responsive inquiry practice. This has enabled me to articulate processes and relationships in water education encounters with meaningful understandings of the effects of simultaneous crises rooted in racial capitalism and environmental crisis. My methodological approach is arts-based educational research with a directive to reflect upon educational encounters in an integrated way. It includes two parts informing the facilitation and analysis of open-ended learning processes. One component was arts-based inquiry practice developed for exploring complexity, drawing on the thinking of Norris (2009, 2011) and Finley (2016, 2017). The second part holds reflective space for these encounters guided by the practice of pedagogical narration inspired by the Reggio Amelia approach, demonstrated by Pacini-Ketchabaw, Nxumalo, Kocher, Elliot and Sanchez (2014). Clarifying the intellectual work of a responsive educator-researcher, pedagogical narration brings multiple theoretical lenses into conversation with emergent dimensions of educational process. In practice, in order to transgress the dominance of colonial white supremacist knowledge frames of water, I needed to be curious, to be confounded, to expect the unexpected in the educational encounters with participants and this mirroring of practice was emulated by the participants as they followed their own questions about water in Mzansi (South Africa). In our work together we came up against assumptions we had previously not questioned as individuals. Together we explored the implications of this by, for example, questioning who is responsible for saving water. These explorations required bringing together science knowledge and everyday knowledge at multiple scales: the household, catchment, government and global. It required us to be critical of how language and images are mobilized in public communication and school curriculums; for example, representations of water are infused with history and power in a way that impacts how we know and teach about water. The transformative potential of this pedagogical space is generated through acts of creative expression which are seen as acts of absenting absence, for example exhibiting through play how water use in the household interconnects with gender and age relationships. As such, creative expression through multiple mediums or more-than-text enables a deeper understanding of water as well as openings for interdisciplinary engagement with learning about water. My research found that in bringing together the contributions of critical education and environmental education in practice, two shifts are needed: environmental educators need to view ecological literacy as inseparable from the social and political. The knowledge that is shared about water in the classroom has social and political implications. On the other hand, critical educators need to better locate justice concerns in the material and ecological world at scale. Arts-based inquiry, as a kind of scaffolding for pedagogical process, has the potential to enable these shifts by opening up fixed analytical frames. Making these shifts requires a reflective practice on the part of the educator to navigate the inherited blind spots in environmental learning and critical education, such as dualities. One way to do this is for the educator to identify absences, as articulated in the Critical Realist tradition, and consider how these absences might be absented. This differs from a simplistic process of critique in the possibilities it opens up for collaboration between different schools of thought rather than further polarisation and alienation between educators and knowledge keepers on social ecologies. These insights have relevance for many sites of environmental education practice, such as natural science lecturers, school teachers or community activists. It is knowledge-learning work emergent from and responsive to complex ecological crisis, which requires everyone to rethink and open up to new ways of being, seeing and doing around these issues. The transformative potential of this work is that the thinking and transforming at all scales can be catalysed and grounded through the arts based educational encounters with the participants. , Thesis (PhD) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-04-08
- Authors: James, Anna Katharine
- Date: 2022-04-08
- Subjects: Environmental education South Africa , Water conservation Study and teaching South Africa , Art in environmental education South Africa , Social learning South Africa , Educational sociology South Africa , Water-supply Social aspects South Africa , Critical realism , Socio-ecological education
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/290660 , vital:56772 , DOI 10.21504/10962/290660
- Description: In this study I explore and explain transformative potential in arts-based environmental learning with a focus on water pedagogy. The study took place over a period of four years, where approximately 40 school pupils between the ages of 10 and 17 years-old were engaged in participatory arts-based inquiries into water located across unequal neighbourhoods in Cape Town, South Africa. Educators, school learners, citizens and decision-makers hold different historical, cultural, political and spiritual perspectives on water. These play a role in shaping what is termed in this research the ‘hydro-social cycle’. Yet, due to dominant ideas of what counts as knowing and truth, educators in educational settings struggle to account for the complexity of water, limiting educational encounters to a partial knowing leading mostly to limited unimaginative framings of problems and solutions. My focus on transformative potential in learning is derived from a concern for how environmental education encounters and the sense-making they enable, are infused by socio-economic, political, and historical elements, specifically colonialism, capitalism, and white supremacist racism. The connections between the multiple layers of capitalist crisis and the ever-urgent environmental crisis are not adequately made in mainstream forms of water education. The research explores how arts-based pedagogy could enable a productive meeting of critical environmental education with ecological literacies. Within this positioning, transformative potential considers how educational engagements position questions about water within the social life of participants/learners and inform learning that leads to fuller and more nuanced greater knowledge. Theoretically, I work with an interrogation of critical education theory, underlaboured by critical realism which enabled me to rigorously consider how claims to knowing are shaped by their accompanying assumptions of what is real. Drawing on recent debates in critical education theory, I resist the notion of critique as ideology and engage instead in the craftsmanship of contextual and responsive inquiry practice. This has enabled me to articulate processes and relationships in water education encounters with meaningful understandings of the effects of simultaneous crises rooted in racial capitalism and environmental crisis. My methodological approach is arts-based educational research with a directive to reflect upon educational encounters in an integrated way. It includes two parts informing the facilitation and analysis of open-ended learning processes. One component was arts-based inquiry practice developed for exploring complexity, drawing on the thinking of Norris (2009, 2011) and Finley (2016, 2017). The second part holds reflective space for these encounters guided by the practice of pedagogical narration inspired by the Reggio Amelia approach, demonstrated by Pacini-Ketchabaw, Nxumalo, Kocher, Elliot and Sanchez (2014). Clarifying the intellectual work of a responsive educator-researcher, pedagogical narration brings multiple theoretical lenses into conversation with emergent dimensions of educational process. In practice, in order to transgress the dominance of colonial white supremacist knowledge frames of water, I needed to be curious, to be confounded, to expect the unexpected in the educational encounters with participants and this mirroring of practice was emulated by the participants as they followed their own questions about water in Mzansi (South Africa). In our work together we came up against assumptions we had previously not questioned as individuals. Together we explored the implications of this by, for example, questioning who is responsible for saving water. These explorations required bringing together science knowledge and everyday knowledge at multiple scales: the household, catchment, government and global. It required us to be critical of how language and images are mobilized in public communication and school curriculums; for example, representations of water are infused with history and power in a way that impacts how we know and teach about water. The transformative potential of this pedagogical space is generated through acts of creative expression which are seen as acts of absenting absence, for example exhibiting through play how water use in the household interconnects with gender and age relationships. As such, creative expression through multiple mediums or more-than-text enables a deeper understanding of water as well as openings for interdisciplinary engagement with learning about water. My research found that in bringing together the contributions of critical education and environmental education in practice, two shifts are needed: environmental educators need to view ecological literacy as inseparable from the social and political. The knowledge that is shared about water in the classroom has social and political implications. On the other hand, critical educators need to better locate justice concerns in the material and ecological world at scale. Arts-based inquiry, as a kind of scaffolding for pedagogical process, has the potential to enable these shifts by opening up fixed analytical frames. Making these shifts requires a reflective practice on the part of the educator to navigate the inherited blind spots in environmental learning and critical education, such as dualities. One way to do this is for the educator to identify absences, as articulated in the Critical Realist tradition, and consider how these absences might be absented. This differs from a simplistic process of critique in the possibilities it opens up for collaboration between different schools of thought rather than further polarisation and alienation between educators and knowledge keepers on social ecologies. These insights have relevance for many sites of environmental education practice, such as natural science lecturers, school teachers or community activists. It is knowledge-learning work emergent from and responsive to complex ecological crisis, which requires everyone to rethink and open up to new ways of being, seeing and doing around these issues. The transformative potential of this work is that the thinking and transforming at all scales can be catalysed and grounded through the arts based educational encounters with the participants. , Thesis (PhD) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-04-08
Towards the Common Good: An expansive post-abyssal (Re)stor(y)ing of the epistemic cultures of the citizen sciences
- Authors: Vallabh, Priya
- Date: 2022-04-08
- Subjects: Science Citizen participation , Decolonization , Social epistemology , Hegemony , Common good , Traditional ecological knowledge , Ethnoscience
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/290671 , vital:56773 , DOI 10.21504/10962/290671
- Description: In this study I explore and explain transformatiThe citizen sciences convene complex and reflexive ecologies of knowledges in response to a range of social-ecological risks. Their epistemic cultures seem to be assembled in ways which increase potential mobilisation of the common knowledges being produced, thereby producing knowledges in forms that are more strongly aligned with a range of implementation strategies. However, much of such processes of knowledge production have been ‘cleaned out’ of official accounts through scientifically hegemonic systems of legitimation, deepening hegemonically-entrenched systems of epistemic, contributory and distributive injustices, and undermining the potential for stronger enactments of participatory and radical democracies. The engagement of sociologies of absences and emergences in this study evidence these epistemic insights, thereby evidencing an expansive post-abyssal (re)stor(y)ing of the citizen sciences. Through this research, I consider knowledge production as ‘commoning', towards the constitution of the common good. To date, most accounts of knowledge production within citizen science projects primarily focus on scientific processes of knowledge production and legitimation. Such accounts neglect the ecologies of diverse knowledges through which knowledge is being collaboratively produced, the forms of learning that occur, or the ways in which such ecologies are mobilised in response to specific socialecological risks. To better understand the ways in which citizen science projects build risk-responsive common knowledge, I bring a focus to the diversity of epistemic cultures convened, speaking to this gap. My primary research question is: How do the epistemic cultures within citizen science projects enable commoning in response to social-ecological risk? To begin, I establish a particular vantage point from which the remainder of the thesis is launched, one which centres as the primary interest of knowledge production, an interest in social-ecological justice and the constitution of the common good. From this vantage point, knowledge co-production and learning can be viewed as acts of commoning, which themselves constitute common goods. I draw on the work of Karin Knorr Cetina to conceptualise and frame notions of epistemic cultures and their epistemic features. Expanding notions of epistemic cultures from a post-abyssal perspective, I draw on the work of Bruno Latour and Boaventura de Sousa Santos. Latour’s distinctions between the production of ‘matters of fact’ and ‘matters of concern’ provide a way to challenge hegemonic systems of scientific knowledge production, while preserving the potential emergence of multiplicity in the context of evolving risk, thereby enabling a greater degree of situated reflexivity. Santos argues for the reclamation of all ways of knowing, including but not limited to scientific ways of knowing the world. He argues that other forms of knowledge are produced as nonexistent, and that they might be reclaimed through engaging sociologies of absences and emergences. Both authors enable a stronger analysis of knowledge production in terms of its ability to intervene into context in response to manifest risks. These three theoretical approaches are convened into an analytical framework for the study. To enact sociologies of absences and emergences, I engage two forms of immanent critique, complemented by an epistemic mapping of 50 South African citizen science projects, and an analysis of three illustrative case studies. The first critique is one of produced nonexistence, through which I consider three aspects of the general knowledge cultures within which the epistemic cultures of citizen science projects are situated. This critique makes evident the ways in which the ontological and related conceptual structures of hegemonic scientific knowledge production actively produce as nonexistent, other onto-epistemic contributions to knowledge production in response to social-ecological risks. The second critique reviews the field of peer-reviewed literature through a reading of presence and absence, with a focus on the articulation of epistemic cultures. Predictably, a key finding is that this form of scientific reporting primarily foregrounds legitimated scientifically processed knowledge, while once again producing as nonexistent, other forms of knowledges. However, there is evidence of increasing accounts of citizen science which recognise both a diversity of knowledge contributions, and epistemic, contributory and distributive justice issues as regards hegemonic forms of reporting. The epistemic mapping evidences a highly diversified field of citizen sciences, whose epistemic cultures are convened to produce distinct forms of scientifically-informed knowledges in response to diverse contexts, scales and notions of risk. The three illustrative case studies engage sociologies of absences and emergences, with particular focus on articulating the ecologies of knowledges evidenced in project documentation, including both official and unofficial accounts of epistemic activity. This analysis highlights the significant contributions of diverse forms of knowledges, including scientific, situated, embodied, governance, indigenous, spiritual and relational knowledges, and the ways in which these knowledge are convened to respond to specific configurations of risk. It once again highlights issues of epistemic, contributory and distributive justice, and makes evident the need for stronger integrity in processes of producing and reporting common knowledges. The case studies also illustrate the increased effectiveness of leveraging an ecology of knowledges (in contrast to a monoculture of scientific knowledge) in response to situated risks, including how such ecologies have a tendency to be generative and enable multiple forms of intervention into structures and applied contexts of intervention. In response to the collective research findings, a think-piece on rigour-as-integrity is offered as a contribution to commoning, in response to social-ecological risk. The piece draws together a postabyssal system of rigour intended to strengthen knowledge production in ways which actively centre forms of justice and commoning. ve potential in arts-based environmental learning with a focus on water pedagogy. The study took place over a period of four years, where approximately 40 school pupils between the ages of 10 and 17 years-old were engaged in participatory arts-based inquiries into water located across unequal neighbourhoods in Cape Town, South Africa. Educators, school learners, citizens and decision-makers hold different historical, cultural, political and spiritual perspectives on water. These play a role in shaping what is termed in this research the ‘hydro-social cycle’. Yet, due to dominant ideas of what counts as knowing and truth, educators in educational settings struggle to account for the complexity of water, limiting educational encounters to a partial knowing leading mostly to limited unimaginative framings of problems and solutions. My focus on transformative potential in learning is derived from a concern for how environmental education encounters and the sense-making they enable, are infused by socio-economic, political, and historical elements, specifically colonialism, capitalism, and white supremacist racism. The connections between the multiple layers of capitalist crisis and the ever-urgent environmental crisis are not adequately made in mainstream forms of water education. The research explores how arts-based pedagogy could enable a productive meeting of critical environmental education with ecological literacies. Within this positioning, transformative potential considers how educational engagements position questions about water within the social life of participants/learners and inform learning that leads to fuller and more nuanced greater knowledge. Theoretically, I work with an interrogation of critical education theory, underlaboured by critical realism which enabled me to rigorously consider how claims to knowing are shaped by their accompanying assumptions of what is real. Drawing on recent debates in critical education theory, I resist the notion of critique as ideology and engage instead in the craftsmanship of contextual and responsive inquiry practice. This has enabled me to articulate processes and relationships in water education encounters with meaningful understandings of the effects of simultaneous crises rooted in racial capitalism and environmental crisis. My methodological approach is arts-based educational research with a directive to reflect upon educational encounters in an integrated way. It includes two parts informing the facilitation and analysis of open-ended learning processes. One component was arts-based inquiry practice developed for exploring complexity, drawing on the thinking of Norris (2009, 2011) and Finley (2016, 2017). The second part holds reflective space for these encounters guided by the practice of pedagogical narration inspired by the Reggio Amelia approach, demonstrated by Pacini-Ketchabaw, Nxumalo, Kocher, Elliot and Sanchez (2014). Clarifying the intellectual work of a responsive educator-researcher, pedagogical narration brings multiple theoretical lenses into conversation with emergent dimensions of educational process. In practice, in order to transgress the dominance of colonial white supremacist knowledge frames of water, I needed to be curious, to be confounded, to expect the unexpected in the educational encounters with participants and this mirroring of practice was emulated by the participants as they followed their own questions about water in Mzansi (South Africa). In our work together we came up against assumptions we had previously not questioned as individuals. Together we explored the implications of this by, for example, questioning who is responsible for saving water. These explorations required bringing together science knowledge and everyday knowledge at multiple scales: the household, catchment, government and global. It required us to be critical of how language and images are mobilized in public communication and school curriculums; for example, representations of water are infused with history and power in a way that impacts how we know and teach about water. The transformative potential of this pedagogical space is generated through acts of creative expression which are seen as acts of absenting absence, for example exhibiting through play how water use in the household interconnects with gender and age relationships. As such, creative expression through multiple mediums or more-than-text enables a deeper understanding of water as well as openings for interdisciplinary engagement with learning about water. My research found that in bringing together the contributions of critical education and environmental education in practice, two shifts are needed: environmental educators need to view ecological literacy as inseparable from the social and political. The knowledge that is shared about water in the classroom has social and political implications. On the other hand, critical educators need to better locate justice concerns in the material and ecological world at scale. Arts-based inquiry, as a kind of scaffolding for pedagogical process, has the potential to enable these shifts by opening up fixed analytical frames. Making these shifts requires a reflective practice on the part of the educator to navigate the inherited blind spots in environmental learning and critical education, such as dualities. One way to do this is for the educator to identify absences, as articulated in the Critical Realist tradition, and consider how these absences might be absented. This differs from a simplistic process of critique in the possibilities it opens up for collaboration between different schools of thought rather than further polarisation and alienation between educators and knowledge keepers on social ecologies. These insights have relevance for many sites of environmental education practice, such as natural science lecturers, school teachers or community activists. It is knowledge-learning work emergent from and responsive to complex ecological crisis, which requires everyone to rethink and open up to new ways of being, seeing and doing around these issues. The transformative potential of this work is that the thinking and transforming at all scales can be catalysed and grounded through the arts based educational encounters with the participants. , Thesis (PhD) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-04-08
- Authors: Vallabh, Priya
- Date: 2022-04-08
- Subjects: Science Citizen participation , Decolonization , Social epistemology , Hegemony , Common good , Traditional ecological knowledge , Ethnoscience
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/290671 , vital:56773 , DOI 10.21504/10962/290671
- Description: In this study I explore and explain transformatiThe citizen sciences convene complex and reflexive ecologies of knowledges in response to a range of social-ecological risks. Their epistemic cultures seem to be assembled in ways which increase potential mobilisation of the common knowledges being produced, thereby producing knowledges in forms that are more strongly aligned with a range of implementation strategies. However, much of such processes of knowledge production have been ‘cleaned out’ of official accounts through scientifically hegemonic systems of legitimation, deepening hegemonically-entrenched systems of epistemic, contributory and distributive injustices, and undermining the potential for stronger enactments of participatory and radical democracies. The engagement of sociologies of absences and emergences in this study evidence these epistemic insights, thereby evidencing an expansive post-abyssal (re)stor(y)ing of the citizen sciences. Through this research, I consider knowledge production as ‘commoning', towards the constitution of the common good. To date, most accounts of knowledge production within citizen science projects primarily focus on scientific processes of knowledge production and legitimation. Such accounts neglect the ecologies of diverse knowledges through which knowledge is being collaboratively produced, the forms of learning that occur, or the ways in which such ecologies are mobilised in response to specific socialecological risks. To better understand the ways in which citizen science projects build risk-responsive common knowledge, I bring a focus to the diversity of epistemic cultures convened, speaking to this gap. My primary research question is: How do the epistemic cultures within citizen science projects enable commoning in response to social-ecological risk? To begin, I establish a particular vantage point from which the remainder of the thesis is launched, one which centres as the primary interest of knowledge production, an interest in social-ecological justice and the constitution of the common good. From this vantage point, knowledge co-production and learning can be viewed as acts of commoning, which themselves constitute common goods. I draw on the work of Karin Knorr Cetina to conceptualise and frame notions of epistemic cultures and their epistemic features. Expanding notions of epistemic cultures from a post-abyssal perspective, I draw on the work of Bruno Latour and Boaventura de Sousa Santos. Latour’s distinctions between the production of ‘matters of fact’ and ‘matters of concern’ provide a way to challenge hegemonic systems of scientific knowledge production, while preserving the potential emergence of multiplicity in the context of evolving risk, thereby enabling a greater degree of situated reflexivity. Santos argues for the reclamation of all ways of knowing, including but not limited to scientific ways of knowing the world. He argues that other forms of knowledge are produced as nonexistent, and that they might be reclaimed through engaging sociologies of absences and emergences. Both authors enable a stronger analysis of knowledge production in terms of its ability to intervene into context in response to manifest risks. These three theoretical approaches are convened into an analytical framework for the study. To enact sociologies of absences and emergences, I engage two forms of immanent critique, complemented by an epistemic mapping of 50 South African citizen science projects, and an analysis of three illustrative case studies. The first critique is one of produced nonexistence, through which I consider three aspects of the general knowledge cultures within which the epistemic cultures of citizen science projects are situated. This critique makes evident the ways in which the ontological and related conceptual structures of hegemonic scientific knowledge production actively produce as nonexistent, other onto-epistemic contributions to knowledge production in response to social-ecological risks. The second critique reviews the field of peer-reviewed literature through a reading of presence and absence, with a focus on the articulation of epistemic cultures. Predictably, a key finding is that this form of scientific reporting primarily foregrounds legitimated scientifically processed knowledge, while once again producing as nonexistent, other forms of knowledges. However, there is evidence of increasing accounts of citizen science which recognise both a diversity of knowledge contributions, and epistemic, contributory and distributive justice issues as regards hegemonic forms of reporting. The epistemic mapping evidences a highly diversified field of citizen sciences, whose epistemic cultures are convened to produce distinct forms of scientifically-informed knowledges in response to diverse contexts, scales and notions of risk. The three illustrative case studies engage sociologies of absences and emergences, with particular focus on articulating the ecologies of knowledges evidenced in project documentation, including both official and unofficial accounts of epistemic activity. This analysis highlights the significant contributions of diverse forms of knowledges, including scientific, situated, embodied, governance, indigenous, spiritual and relational knowledges, and the ways in which these knowledge are convened to respond to specific configurations of risk. It once again highlights issues of epistemic, contributory and distributive justice, and makes evident the need for stronger integrity in processes of producing and reporting common knowledges. The case studies also illustrate the increased effectiveness of leveraging an ecology of knowledges (in contrast to a monoculture of scientific knowledge) in response to situated risks, including how such ecologies have a tendency to be generative and enable multiple forms of intervention into structures and applied contexts of intervention. In response to the collective research findings, a think-piece on rigour-as-integrity is offered as a contribution to commoning, in response to social-ecological risk. The piece draws together a postabyssal system of rigour intended to strengthen knowledge production in ways which actively centre forms of justice and commoning. ve potential in arts-based environmental learning with a focus on water pedagogy. The study took place over a period of four years, where approximately 40 school pupils between the ages of 10 and 17 years-old were engaged in participatory arts-based inquiries into water located across unequal neighbourhoods in Cape Town, South Africa. Educators, school learners, citizens and decision-makers hold different historical, cultural, political and spiritual perspectives on water. These play a role in shaping what is termed in this research the ‘hydro-social cycle’. Yet, due to dominant ideas of what counts as knowing and truth, educators in educational settings struggle to account for the complexity of water, limiting educational encounters to a partial knowing leading mostly to limited unimaginative framings of problems and solutions. My focus on transformative potential in learning is derived from a concern for how environmental education encounters and the sense-making they enable, are infused by socio-economic, political, and historical elements, specifically colonialism, capitalism, and white supremacist racism. The connections between the multiple layers of capitalist crisis and the ever-urgent environmental crisis are not adequately made in mainstream forms of water education. The research explores how arts-based pedagogy could enable a productive meeting of critical environmental education with ecological literacies. Within this positioning, transformative potential considers how educational engagements position questions about water within the social life of participants/learners and inform learning that leads to fuller and more nuanced greater knowledge. Theoretically, I work with an interrogation of critical education theory, underlaboured by critical realism which enabled me to rigorously consider how claims to knowing are shaped by their accompanying assumptions of what is real. Drawing on recent debates in critical education theory, I resist the notion of critique as ideology and engage instead in the craftsmanship of contextual and responsive inquiry practice. This has enabled me to articulate processes and relationships in water education encounters with meaningful understandings of the effects of simultaneous crises rooted in racial capitalism and environmental crisis. My methodological approach is arts-based educational research with a directive to reflect upon educational encounters in an integrated way. It includes two parts informing the facilitation and analysis of open-ended learning processes. One component was arts-based inquiry practice developed for exploring complexity, drawing on the thinking of Norris (2009, 2011) and Finley (2016, 2017). The second part holds reflective space for these encounters guided by the practice of pedagogical narration inspired by the Reggio Amelia approach, demonstrated by Pacini-Ketchabaw, Nxumalo, Kocher, Elliot and Sanchez (2014). Clarifying the intellectual work of a responsive educator-researcher, pedagogical narration brings multiple theoretical lenses into conversation with emergent dimensions of educational process. In practice, in order to transgress the dominance of colonial white supremacist knowledge frames of water, I needed to be curious, to be confounded, to expect the unexpected in the educational encounters with participants and this mirroring of practice was emulated by the participants as they followed their own questions about water in Mzansi (South Africa). In our work together we came up against assumptions we had previously not questioned as individuals. Together we explored the implications of this by, for example, questioning who is responsible for saving water. These explorations required bringing together science knowledge and everyday knowledge at multiple scales: the household, catchment, government and global. It required us to be critical of how language and images are mobilized in public communication and school curriculums; for example, representations of water are infused with history and power in a way that impacts how we know and teach about water. The transformative potential of this pedagogical space is generated through acts of creative expression which are seen as acts of absenting absence, for example exhibiting through play how water use in the household interconnects with gender and age relationships. As such, creative expression through multiple mediums or more-than-text enables a deeper understanding of water as well as openings for interdisciplinary engagement with learning about water. My research found that in bringing together the contributions of critical education and environmental education in practice, two shifts are needed: environmental educators need to view ecological literacy as inseparable from the social and political. The knowledge that is shared about water in the classroom has social and political implications. On the other hand, critical educators need to better locate justice concerns in the material and ecological world at scale. Arts-based inquiry, as a kind of scaffolding for pedagogical process, has the potential to enable these shifts by opening up fixed analytical frames. Making these shifts requires a reflective practice on the part of the educator to navigate the inherited blind spots in environmental learning and critical education, such as dualities. One way to do this is for the educator to identify absences, as articulated in the Critical Realist tradition, and consider how these absences might be absented. This differs from a simplistic process of critique in the possibilities it opens up for collaboration between different schools of thought rather than further polarisation and alienation between educators and knowledge keepers on social ecologies. These insights have relevance for many sites of environmental education practice, such as natural science lecturers, school teachers or community activists. It is knowledge-learning work emergent from and responsive to complex ecological crisis, which requires everyone to rethink and open up to new ways of being, seeing and doing around these issues. The transformative potential of this work is that the thinking and transforming at all scales can be catalysed and grounded through the arts based educational encounters with the participants. , Thesis (PhD) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-04-08
Institutional self-deception
- Jacot-Guillarmod, Genevieve Nicole
- Authors: Jacot-Guillarmod, Genevieve Nicole
- Date: 2022-04-07
- Subjects: Self-deception , Business ethics , Social responsibility of business , Responsibility , Collective behavior Moral and ethical aspects , Attribution (Social psychology)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294548 , vital:57231 , DOI https://doi.org/10.21504/10962/294548
- Description: There are many examples of institutions which have made false claims, or performed certain acts, that have had, to varying degrees, a negative impact on their societies. For example, many corporations go to great lengths to present themselves as being environmentally friendly when in fact they are not. Many corporations have also been forced to recall dangerous products which they at one time or another insisted were safe. Research teams have misled participants with regard to what they can expect from their participation in studies, with grave consequences. Governments throughout the world are mired in corruption, and yet deny that this is so. One possible explanation is that in such situations these institutions are simply lying. However, another possible explanation is that these institutions are self-deceived, or lying to themselves. Recently it has been suggested that self-deception is something that affects certain groups as well as individuals. Given that institutions can wield a great deal of political, social and economic power, if institutions are capable of self-deception there is room for things to go awry on a very large scale with potentially dire consequences. Yet the explanations currently on offer for group-level self-deception appear to amount to instances of individual self-deception (either to certain key individual members of those groups being self-deceived, or to all or most members of a group sharing the same self-deceptive belief), and as such I do not regard the explanations currently on offer as satisfactory. I propose that there are certain situations in which we ought to see institutions themselves as self-deceived or lying to themselves. While the terms ‘self-deception’ and ‘lying to oneself’ are often used interchangeably, I differentiate between the two and argue that both institutional self-deception and an institution lying to itself are institution-level phenomena, and do not rely on any individual within the institution being self-deceived or lying to themselves. That this is so is of relevance to our attributions of accountability, and makes changes to institutional structure and procedures the focus of concern when it comes to preventing an institution succumbing to self-deception or lying to itself. , Thesis (PhD) -- Faculty of Humanities, Philosophy, 2022
- Full Text:
- Date Issued: 2022-04-07
- Authors: Jacot-Guillarmod, Genevieve Nicole
- Date: 2022-04-07
- Subjects: Self-deception , Business ethics , Social responsibility of business , Responsibility , Collective behavior Moral and ethical aspects , Attribution (Social psychology)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294548 , vital:57231 , DOI https://doi.org/10.21504/10962/294548
- Description: There are many examples of institutions which have made false claims, or performed certain acts, that have had, to varying degrees, a negative impact on their societies. For example, many corporations go to great lengths to present themselves as being environmentally friendly when in fact they are not. Many corporations have also been forced to recall dangerous products which they at one time or another insisted were safe. Research teams have misled participants with regard to what they can expect from their participation in studies, with grave consequences. Governments throughout the world are mired in corruption, and yet deny that this is so. One possible explanation is that in such situations these institutions are simply lying. However, another possible explanation is that these institutions are self-deceived, or lying to themselves. Recently it has been suggested that self-deception is something that affects certain groups as well as individuals. Given that institutions can wield a great deal of political, social and economic power, if institutions are capable of self-deception there is room for things to go awry on a very large scale with potentially dire consequences. Yet the explanations currently on offer for group-level self-deception appear to amount to instances of individual self-deception (either to certain key individual members of those groups being self-deceived, or to all or most members of a group sharing the same self-deceptive belief), and as such I do not regard the explanations currently on offer as satisfactory. I propose that there are certain situations in which we ought to see institutions themselves as self-deceived or lying to themselves. While the terms ‘self-deception’ and ‘lying to oneself’ are often used interchangeably, I differentiate between the two and argue that both institutional self-deception and an institution lying to itself are institution-level phenomena, and do not rely on any individual within the institution being self-deceived or lying to themselves. That this is so is of relevance to our attributions of accountability, and makes changes to institutional structure and procedures the focus of concern when it comes to preventing an institution succumbing to self-deception or lying to itself. , Thesis (PhD) -- Faculty of Humanities, Philosophy, 2022
- Full Text:
- Date Issued: 2022-04-07
The fiction of scarcity: conceptualising scarcity in terms of global justice
- Authors: Brotherton, Michelle
- Date: 2022-04-07
- Subjects: Scarcity Philosophy , Distributive justice , Political science Philosophy , Philosophy , Justification (Ethics) , Fallacies (Logic)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294526 , vital:57229 , DOI https://dx.doi.org/10.21504/10962/294526
- Description: This thesis intends to contribute to the discourse on global justice as it pertains to resources, the distribution of resources, and the allocation of resources. The focus is on the concept of scarcity. I examine scarcity for how it is understood, interpreted, and applied in the literature on global justice. This thesis argues that scarcity lacks conceptual clarity in the discourse on global justice and argues that if scarcity is misconstrued, the consequences can be severe. Conceptual clarity is thus necessary to ensure that scarcity is properly referred to in the discourse on global justice so that scarcity is not erroneously used when justifications are sought for material deprivation and consequent human suffering. In the process, I will also examine how scarcity is used as a justification in instances of material deprivation and why this is problematic. Given the lack of conceptual clarity regarding scarcity, I argue that reliance on scarcity as justification may be erroneous. The conflation of absolute scarcity and relative scarcity may amount to a category mistake. This thesis purports to clarify scarcity conceptually in the context of global justice. In doing so, I recommend that a resource-centric approach to resource scarcity is adopted to accurately account for the scarcity status of resources. A resource-centric approach to resource scarcity based on a more nuanced understanding of scarcity avoids the potential category mistake. Such an approach ensures that material deprivation and consequent human suffering are not wrongfully attributed to scarcity. , Thesis (PhD) -- Faculty of Humanities, Philosophy, 2022
- Full Text:
- Date Issued: 2022-04-07
- Authors: Brotherton, Michelle
- Date: 2022-04-07
- Subjects: Scarcity Philosophy , Distributive justice , Political science Philosophy , Philosophy , Justification (Ethics) , Fallacies (Logic)
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294526 , vital:57229 , DOI https://dx.doi.org/10.21504/10962/294526
- Description: This thesis intends to contribute to the discourse on global justice as it pertains to resources, the distribution of resources, and the allocation of resources. The focus is on the concept of scarcity. I examine scarcity for how it is understood, interpreted, and applied in the literature on global justice. This thesis argues that scarcity lacks conceptual clarity in the discourse on global justice and argues that if scarcity is misconstrued, the consequences can be severe. Conceptual clarity is thus necessary to ensure that scarcity is properly referred to in the discourse on global justice so that scarcity is not erroneously used when justifications are sought for material deprivation and consequent human suffering. In the process, I will also examine how scarcity is used as a justification in instances of material deprivation and why this is problematic. Given the lack of conceptual clarity regarding scarcity, I argue that reliance on scarcity as justification may be erroneous. The conflation of absolute scarcity and relative scarcity may amount to a category mistake. This thesis purports to clarify scarcity conceptually in the context of global justice. In doing so, I recommend that a resource-centric approach to resource scarcity is adopted to accurately account for the scarcity status of resources. A resource-centric approach to resource scarcity based on a more nuanced understanding of scarcity avoids the potential category mistake. Such an approach ensures that material deprivation and consequent human suffering are not wrongfully attributed to scarcity. , Thesis (PhD) -- Faculty of Humanities, Philosophy, 2022
- Full Text:
- Date Issued: 2022-04-07
Umzi ka Mama Family property transfer practices and the historical significance of title deeds to African female heads of household in Fingo Village: a participatory theatre approach
- Authors: Hellemann, Phemelo Cordelia
- Date: 2022-04-07
- Subjects: Public history South Africa Eastern Cape , Oral history South Africa Eastern Cape , Women Housing South Africa Eastern Cape , Feminism Africa , Apartheid Law and legislation South Africa , Participatory theater South Africa Eastern Cape , Playback theater , Theater and society South Africa Eastern Cape , History Citizen participation , South Africa. Group Areas Act, 1950
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294537 , vital:57230 , DOI https://doi.org/10.21504/10962/294537
- Description: Many everyday stories and experiences of African women remain underrepresented and undocumented. For example, the omission of Fingo Village women’s names from official deeds records silenced their voices. African women faced gender and racial discrimination that denied them fundamental human rights and limited their participation in urban life. Title deed records constitute one type of public record where African women’s names were omitted for centuries by the colonial and apartheid governments. Under apartheid, African women occupied the social status of minors; hence, the government denied them urban land rights. This African feminist study enlists narratives of a sample of seven African female heads of households residing in Fingo Village who are also property owners. Fingo Village is an atypical environment where African people had a rare legal advantage of owning title deeds dating back to 1855. This study employed an interdisciplinary approach by mixing oral history methodology and applied theatre methods to record, interpret and present Fingo Village women’s narratives of family property inheritance and the significance of title deed documentation in the suburb. The multiple technique approach created opportunities for authentic dialogue between the researcher and the participants beyond the inherent limitations of public history oral interviews. The traditional oral history interview and the participatory theatre methods helped uncover unconventional practices in family property relations. Though customary transfers of family homes to custodians were prevalent, title deed registration of family property was also acknowledged as a vital practice that empowered women legally. The researcher used participatory theatre techniques inspired by playback, image and forum theatre to enhance the researcher and participants’ relationship. These methods encouraged the researcher and respondents’ shared authority as they embarked on an extended participatory research project. In this regard, through dialogical and performance-based activities, the participants and the researcher became co-creators of untold Fingo Village stories. Moreover, the theatre techniques became interpretation and analysis tools that ensured that the participants’ untold stories were well represented. The first phase of the research involved engaging with the literature about the title deeds history of Fingo Village and conducting oral history interviews that served as data. In the second phase, the interviews were analysed and packaged in a documentary format. The third phase was a playback theatre inspired session in a 10-minute performance based on themes from the participants’ filmed interviews. Additionally, the performance was a catalyst for forum theatre activities that allowed the participants to interact with the performer and suggest solutions to the dilemma posed by the performer regarding family property use. The participants were decision-makers and family property relations experts within this imagined context. In the fourth phase, the image theatre adaptation and memory work activities were essential tools. The tools aided the visuals and information from an existing Fingo Village exhibition as additional resources that prompted dialogue and discussions. The exhibition encouraged participants to share their personal experiences and memories of the Group Areas Act (GAA) era. The findings showed that the GAA era saw many families revert to communal tenure practices as a strategy to evade forced sales; as such, this gave rise to undocumented family property transfers. Additionally, the findings revealed that though customary practices are often patriarchal, there are circumstances favouring women as the preferred family property custodian. These are embedded in the social status of women who are traditional healers, firstborn daughters, and those from families with just daughters. This study contributes to the growing literature that advocates for positive representation of African women’s stories by using active research methodologies that strengthen partnerships and shared authority between the researcher and the public. This methodology could inspire other researchers to explore theatre techniques to create more profound and meaningful engagements with their participants. The links to the video materials accompanying this thesis are provided on the contents page. , Thesis (PhD) -- Faculty of Humanities, History, 2022
- Full Text:
- Date Issued: 2022-04-07
- Authors: Hellemann, Phemelo Cordelia
- Date: 2022-04-07
- Subjects: Public history South Africa Eastern Cape , Oral history South Africa Eastern Cape , Women Housing South Africa Eastern Cape , Feminism Africa , Apartheid Law and legislation South Africa , Participatory theater South Africa Eastern Cape , Playback theater , Theater and society South Africa Eastern Cape , History Citizen participation , South Africa. Group Areas Act, 1950
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/294537 , vital:57230 , DOI https://doi.org/10.21504/10962/294537
- Description: Many everyday stories and experiences of African women remain underrepresented and undocumented. For example, the omission of Fingo Village women’s names from official deeds records silenced their voices. African women faced gender and racial discrimination that denied them fundamental human rights and limited their participation in urban life. Title deed records constitute one type of public record where African women’s names were omitted for centuries by the colonial and apartheid governments. Under apartheid, African women occupied the social status of minors; hence, the government denied them urban land rights. This African feminist study enlists narratives of a sample of seven African female heads of households residing in Fingo Village who are also property owners. Fingo Village is an atypical environment where African people had a rare legal advantage of owning title deeds dating back to 1855. This study employed an interdisciplinary approach by mixing oral history methodology and applied theatre methods to record, interpret and present Fingo Village women’s narratives of family property inheritance and the significance of title deed documentation in the suburb. The multiple technique approach created opportunities for authentic dialogue between the researcher and the participants beyond the inherent limitations of public history oral interviews. The traditional oral history interview and the participatory theatre methods helped uncover unconventional practices in family property relations. Though customary transfers of family homes to custodians were prevalent, title deed registration of family property was also acknowledged as a vital practice that empowered women legally. The researcher used participatory theatre techniques inspired by playback, image and forum theatre to enhance the researcher and participants’ relationship. These methods encouraged the researcher and respondents’ shared authority as they embarked on an extended participatory research project. In this regard, through dialogical and performance-based activities, the participants and the researcher became co-creators of untold Fingo Village stories. Moreover, the theatre techniques became interpretation and analysis tools that ensured that the participants’ untold stories were well represented. The first phase of the research involved engaging with the literature about the title deeds history of Fingo Village and conducting oral history interviews that served as data. In the second phase, the interviews were analysed and packaged in a documentary format. The third phase was a playback theatre inspired session in a 10-minute performance based on themes from the participants’ filmed interviews. Additionally, the performance was a catalyst for forum theatre activities that allowed the participants to interact with the performer and suggest solutions to the dilemma posed by the performer regarding family property use. The participants were decision-makers and family property relations experts within this imagined context. In the fourth phase, the image theatre adaptation and memory work activities were essential tools. The tools aided the visuals and information from an existing Fingo Village exhibition as additional resources that prompted dialogue and discussions. The exhibition encouraged participants to share their personal experiences and memories of the Group Areas Act (GAA) era. The findings showed that the GAA era saw many families revert to communal tenure practices as a strategy to evade forced sales; as such, this gave rise to undocumented family property transfers. Additionally, the findings revealed that though customary practices are often patriarchal, there are circumstances favouring women as the preferred family property custodian. These are embedded in the social status of women who are traditional healers, firstborn daughters, and those from families with just daughters. This study contributes to the growing literature that advocates for positive representation of African women’s stories by using active research methodologies that strengthen partnerships and shared authority between the researcher and the public. This methodology could inspire other researchers to explore theatre techniques to create more profound and meaningful engagements with their participants. The links to the video materials accompanying this thesis are provided on the contents page. , Thesis (PhD) -- Faculty of Humanities, History, 2022
- Full Text:
- Date Issued: 2022-04-07
A framework for guiding the interdisciplinary design of mHealth intervention apps for physical activity behaviour change
- Authors: Thomson, Callie Deborah
- Date: 2022-04-06
- Subjects: Wireless communication systems in medical care , Exercise Health aspects , Behavior modification , Mobile apps , Medical care Technological innovations , Medical informatics , Health promotion Technological innovations , Application software Development , Design Science Research (DSR)
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/232193 , vital:49970 , DOI http://doi.org/10.21504/10962/232193
- Description: The global pandemic of noncommunicable diseases and its associated premature mortality rates and socioeconomic burden have led to increasingly intensified efforts towards designing and delivering health promotion interventions aimed at addressing the leading modifiable health risk behaviours, such as physical inactivity. Developing physical activity behaviour change interventions that target individuals at the dual intra-interpersonal socioecological levels of health promotion has become a key objective worldwide. Digital and mobile technology is revolutionising the ways in which health behaviour change interventions are delivered to individuals across the world, with mobile health applications (mHealth apps) increasingly recognised as a powerful means of promoting physical activity behaviour change. However, with the growth and opportunities of mHealth apps, come several design challenges. Key design challenges concern the integration of theory, the incorporation of evidence-based behaviour change techniques, the application of persuasive systems design principles, and the importance of multi- and interdisciplinary collaborative design, development and evaluation approaches. These key challenges influence the output product design and effectiveness of mHealth physical activity behaviour change intervention apps. There exists a paucity of approaches for guiding and supporting the multi- and interdisciplinary collaborative design, development and evaluation of mHealth physical activity behaviour change intervention apps. To address this gap, this research study proposes an Interdisciplinary mHealth App Design Framework, framed by a novel boundary object view. This view considers the diverse communities of practice, boundary objects and supporting artefacts, process activities, and knowledge sharing practices necessary and relevant to the design of effective mHealth physical activity behaviour change intervention apps. The framework’s development is guided by a Design Science Research (DSR) approach. Its core components are based on the findings of a critical theoretical analysis of twenty existing multi- and interdisciplinary digital health development approaches. Once developed, the framework is evaluated using a qualitative DSR linguistic interpretivist approach, with semi-structured interviews as the research instrument. The thematic analysis findings from interviews with thirty-one international academic researchers and industry practitioners informs the iterative modification and revision of an enhanced Interdisciplinary mHealth App Design Framework, constituting the main DSR artefact contribution of the research study. In addition, four theoretical contributions are made to the mHealth intervention app design body of knowledge, and a practical contribution is made through the provision of guideline recommendations for academics and industry practitioners. Methodological contributions are also made in terms of applying DSR, adopting a hybrid cognitive reasoning strategy, and employing a qualitative linguistic interpretivist approach to evaluation within a DSR project. , Thesis (PhD) -- Faculty of Commerce, Information Systems, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Thomson, Callie Deborah
- Date: 2022-04-06
- Subjects: Wireless communication systems in medical care , Exercise Health aspects , Behavior modification , Mobile apps , Medical care Technological innovations , Medical informatics , Health promotion Technological innovations , Application software Development , Design Science Research (DSR)
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/232193 , vital:49970 , DOI http://doi.org/10.21504/10962/232193
- Description: The global pandemic of noncommunicable diseases and its associated premature mortality rates and socioeconomic burden have led to increasingly intensified efforts towards designing and delivering health promotion interventions aimed at addressing the leading modifiable health risk behaviours, such as physical inactivity. Developing physical activity behaviour change interventions that target individuals at the dual intra-interpersonal socioecological levels of health promotion has become a key objective worldwide. Digital and mobile technology is revolutionising the ways in which health behaviour change interventions are delivered to individuals across the world, with mobile health applications (mHealth apps) increasingly recognised as a powerful means of promoting physical activity behaviour change. However, with the growth and opportunities of mHealth apps, come several design challenges. Key design challenges concern the integration of theory, the incorporation of evidence-based behaviour change techniques, the application of persuasive systems design principles, and the importance of multi- and interdisciplinary collaborative design, development and evaluation approaches. These key challenges influence the output product design and effectiveness of mHealth physical activity behaviour change intervention apps. There exists a paucity of approaches for guiding and supporting the multi- and interdisciplinary collaborative design, development and evaluation of mHealth physical activity behaviour change intervention apps. To address this gap, this research study proposes an Interdisciplinary mHealth App Design Framework, framed by a novel boundary object view. This view considers the diverse communities of practice, boundary objects and supporting artefacts, process activities, and knowledge sharing practices necessary and relevant to the design of effective mHealth physical activity behaviour change intervention apps. The framework’s development is guided by a Design Science Research (DSR) approach. Its core components are based on the findings of a critical theoretical analysis of twenty existing multi- and interdisciplinary digital health development approaches. Once developed, the framework is evaluated using a qualitative DSR linguistic interpretivist approach, with semi-structured interviews as the research instrument. The thematic analysis findings from interviews with thirty-one international academic researchers and industry practitioners informs the iterative modification and revision of an enhanced Interdisciplinary mHealth App Design Framework, constituting the main DSR artefact contribution of the research study. In addition, four theoretical contributions are made to the mHealth intervention app design body of knowledge, and a practical contribution is made through the provision of guideline recommendations for academics and industry practitioners. Methodological contributions are also made in terms of applying DSR, adopting a hybrid cognitive reasoning strategy, and employing a qualitative linguistic interpretivist approach to evaluation within a DSR project. , Thesis (PhD) -- Faculty of Commerce, Information Systems, 2022
- Full Text:
- Date Issued: 2022-04-06
A framework for the economic valuation of wetland rehabilitation: case studies from South Africa
- Authors: Browne, Michelle
- Date: 2022-04-06
- Subjects: Wetland restoration South Africa , Wetland management South Africa , Ecosystem management South Africa , Ecosystem services South Africa , Ecosystem management Economic aspects South Africa , Wetland restoration Cost effectiveness South Africa
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/263560 , vital:53638 , DOI 10.21504/10962/263561
- Description: Wetlands are recognised as having the potential to contribute long-term benefits to society; wetland rehabilitation is undertaken to recover these benefits in response to widespread wetland degradation. Increasingly, there have been calls to value the benefits of wetland rehabilitation to justify further investment. Such is the case in South Africa. Furthermore, recent global agendas and targets for ecosystem restoration, such as the declaration of the Decade of Restoration 2021-2030, suggest increasing pressure on governments to implement rehabilitation and imply a concomitant increase in decision-making regarding where and how to rehabilitate. In response to these information needs, this thesis explores the economic valuation of wetland rehabilitation through a narrative review of the foundational theory of values and valuation, a quantitative review of applied wetland rehabilitation economic valuation studies, and the evaluation of five wetland rehabilitation projects from South Africa. Projects were selected as case studies to represent various rehabilitation goals and explore different contexts (urban-rural; beneficiary groups), the timing of the evaluation (ex ante, ex post) and value types and valuation methods. The final chapter of the thesis integrates the case study experiences with the findings of the theoretical research components to propose a framework for the valuation of wetland rehabilitation, which can be applied in South Africa, and more generally, to further demonstrate the values of wetland rehabilitation, and as a tool to guide wetland rehabilitation decision-making. While initially grounded in mainstream economics, the research led into a number of fields including philosophy, social-ecological systems and social-ecological relations thinking, several environmental science areas and livelihood and human well-being frameworks. A deeper look into economic theory and history revealed an evolution of thinking on the meaning of ‘value’ and view of ‘nature’ and numerous critiques of standard neoclassical economics. From the insights gained and the case study experiences, this thesis argues that the neoclassical economic perspective, especially combined with a monetary metric, is too restrictive, and arguably too abstract in its assumptions of human behaviour and reliance on mathematical models, as an overarching framework for the valuation of wetland rehabilition. This is not to suggest that standard economic valuation concepts and methods cannot be useful, as the research case studies illustrated, but rather that wetland valuation must be approached from a value pluralism perspective. To this end, the proposed framework offers a way to think beyond, or in addition to, standard economic approaches in articulating the values of wetland rehabilitation. , Thesis (PhD) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Browne, Michelle
- Date: 2022-04-06
- Subjects: Wetland restoration South Africa , Wetland management South Africa , Ecosystem management South Africa , Ecosystem services South Africa , Ecosystem management Economic aspects South Africa , Wetland restoration Cost effectiveness South Africa
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/263560 , vital:53638 , DOI 10.21504/10962/263561
- Description: Wetlands are recognised as having the potential to contribute long-term benefits to society; wetland rehabilitation is undertaken to recover these benefits in response to widespread wetland degradation. Increasingly, there have been calls to value the benefits of wetland rehabilitation to justify further investment. Such is the case in South Africa. Furthermore, recent global agendas and targets for ecosystem restoration, such as the declaration of the Decade of Restoration 2021-2030, suggest increasing pressure on governments to implement rehabilitation and imply a concomitant increase in decision-making regarding where and how to rehabilitate. In response to these information needs, this thesis explores the economic valuation of wetland rehabilitation through a narrative review of the foundational theory of values and valuation, a quantitative review of applied wetland rehabilitation economic valuation studies, and the evaluation of five wetland rehabilitation projects from South Africa. Projects were selected as case studies to represent various rehabilitation goals and explore different contexts (urban-rural; beneficiary groups), the timing of the evaluation (ex ante, ex post) and value types and valuation methods. The final chapter of the thesis integrates the case study experiences with the findings of the theoretical research components to propose a framework for the valuation of wetland rehabilitation, which can be applied in South Africa, and more generally, to further demonstrate the values of wetland rehabilitation, and as a tool to guide wetland rehabilitation decision-making. While initially grounded in mainstream economics, the research led into a number of fields including philosophy, social-ecological systems and social-ecological relations thinking, several environmental science areas and livelihood and human well-being frameworks. A deeper look into economic theory and history revealed an evolution of thinking on the meaning of ‘value’ and view of ‘nature’ and numerous critiques of standard neoclassical economics. From the insights gained and the case study experiences, this thesis argues that the neoclassical economic perspective, especially combined with a monetary metric, is too restrictive, and arguably too abstract in its assumptions of human behaviour and reliance on mathematical models, as an overarching framework for the valuation of wetland rehabilition. This is not to suggest that standard economic valuation concepts and methods cannot be useful, as the research case studies illustrated, but rather that wetland valuation must be approached from a value pluralism perspective. To this end, the proposed framework offers a way to think beyond, or in addition to, standard economic approaches in articulating the values of wetland rehabilitation. , Thesis (PhD) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-04-06
A 5G Communication system based on flexible spectrum technology for the SKA
- Authors: Karembera, Reinhard Siwombe
- Date: 2022-04
- Subjects: Mobile communication systems--Technological innovations , Wireless communication systems -- Standards --South Africa
- Language: English
- Type: Doctoral theses
- Identifier: http://hdl.handle.net/10948/56177 , vital:56013
- Description: Faculty of Science Radio astronomy research is rapidly expanding across the African continent. At the same time, the fifth generation (5G) of mobile communication systems are also being researched and developed. Throughout history, mobile communication networks are known to affect the activities of radio astronomy. If not carefully managed, radio frequencies from mobile communication devices can severely affect radio astronomy observations. To that end, many techniques have been proposed to protect the radio astronomer from RFIs coming from radio communication networks. Some of the proposed techniques such as RFI quite zones and spectrum assignment by regulatory authorities will not be convenient during the implementation of 5G mobile networks. This is because 5G radio communication systems are expected to support spectrum-hungry application such as video-on-demand, augmented realities, high-definition television and so on. To realize this, the 5G networks will be forced to have access to protected radio spectrum, including those at which radio astronomy activities are being researched. To facilitate this, the 5G radio communication networks should have the intelligence to coexist within such protected spectrums without the consequences of radio frequency interferences (RFI) to the primary user. In this thesis, we present novel 5G networks with the intelligence that allow them to coexist within radio astronomy areas without introducing RFIs to the primary user. We proposed a photonic solution, keeping in mind the characteristic requirements for future 5G radio communication networks. The thesis begins by reviewing the current trend of radio astronomy research in Africa. It was found that radio astronomy research in Africa is growing rapidly. Many African countries such as South Africa and Ghana are at advanced stages when it comes to radio astronomy research. Therefore, the finding and proposal of this thesis will be valuable to such countries. In order to develop a radio access network (RAN) that can coexist within radio astronomy areas, the thesis reviewed past and present state-of-the-art RANs. Each access network was analyses for its feasibility to be implemented within radio astronomy areas to realize mobile communication without the consequences of RFIs to the astronomer. It was motivated that the current centralized radio access network (C-RAN) the best solution to be developed for radio communication within radio astronomy areas. This is because the C-RAN architecture is centralized by pooling network resources to a common point. From such pool, network resources can be controlled and shared among 5G network user, including radio astronomers and the surrounding communities. The next chapters reviewed photonic RF transmitters and their associated lasers currently being proposed to be used within C-RANs. , Thesis (PhD) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Karembera, Reinhard Siwombe
- Date: 2022-04
- Subjects: Mobile communication systems--Technological innovations , Wireless communication systems -- Standards --South Africa
- Language: English
- Type: Doctoral theses
- Identifier: http://hdl.handle.net/10948/56177 , vital:56013
- Description: Faculty of Science Radio astronomy research is rapidly expanding across the African continent. At the same time, the fifth generation (5G) of mobile communication systems are also being researched and developed. Throughout history, mobile communication networks are known to affect the activities of radio astronomy. If not carefully managed, radio frequencies from mobile communication devices can severely affect radio astronomy observations. To that end, many techniques have been proposed to protect the radio astronomer from RFIs coming from radio communication networks. Some of the proposed techniques such as RFI quite zones and spectrum assignment by regulatory authorities will not be convenient during the implementation of 5G mobile networks. This is because 5G radio communication systems are expected to support spectrum-hungry application such as video-on-demand, augmented realities, high-definition television and so on. To realize this, the 5G networks will be forced to have access to protected radio spectrum, including those at which radio astronomy activities are being researched. To facilitate this, the 5G radio communication networks should have the intelligence to coexist within such protected spectrums without the consequences of radio frequency interferences (RFI) to the primary user. In this thesis, we present novel 5G networks with the intelligence that allow them to coexist within radio astronomy areas without introducing RFIs to the primary user. We proposed a photonic solution, keeping in mind the characteristic requirements for future 5G radio communication networks. The thesis begins by reviewing the current trend of radio astronomy research in Africa. It was found that radio astronomy research in Africa is growing rapidly. Many African countries such as South Africa and Ghana are at advanced stages when it comes to radio astronomy research. Therefore, the finding and proposal of this thesis will be valuable to such countries. In order to develop a radio access network (RAN) that can coexist within radio astronomy areas, the thesis reviewed past and present state-of-the-art RANs. Each access network was analyses for its feasibility to be implemented within radio astronomy areas to realize mobile communication without the consequences of RFIs to the astronomer. It was motivated that the current centralized radio access network (C-RAN) the best solution to be developed for radio communication within radio astronomy areas. This is because the C-RAN architecture is centralized by pooling network resources to a common point. From such pool, network resources can be controlled and shared among 5G network user, including radio astronomers and the surrounding communities. The next chapters reviewed photonic RF transmitters and their associated lasers currently being proposed to be used within C-RANs. , Thesis (PhD) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2022
- Full Text:
- Date Issued: 2022-04
A case study assessment of the ecological and social status of the South African boat-based whale watching industry
- Authors: Tolsma, Minke
- Date: 2022-04
- Subjects: Whale watching --South Africa , Dolphin watching
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55887 , vital:54397
- Description: Boat-based whale-watching (BBWW) is a rapidly growing marine tourism industry globally and in South Africa (SA). BBWW in SA was established in 1998, and since then the number of permits available has doubled from 20 to 40. However, the establishment and past growth of the industry was undertaken without ecological research or impact assessments. Global research has shown that BBWW has the potential to cause short-term changes in cetacean behaviour and movement, which in turn can have long-term population-level consequences. National policies to grow ocean economies in SA may encourage excessive growth in the BBWW industry, impacting the ecological sustainability. In the absence of long-term impact data, the BBWW industry should be managed to minimise short-term changes. This study aimed to determine the social and ecological status of the SA BBWW industry, using Plettenberg Bay as a case study, to inform its long term sustainability. To achieve this aim: 1) the short-term behavioural and movement responses of six cetacean species to encounters with commercial BBWW vessels were measured; 2) the efficacy of three permit regulations (approach speed, approach angle, and encounter duration) to prevent short-term behavioural changes in three cetacean species was measured; 3) rates of compliance of BBWWoperators with current regulations were recorded; 4) BBWW tourists’ expectations of and satisfaction with the industry were investigated; as well as 5) operators’ views on the current permit regulations of the industry All research was conducted between September 2018 and November 2020 in Plettenberg Bay (SA) where two BBWW companies operating two vessels each are active. Three dolphin (bottlenose, common and humpback dolphins) and three whale (Bryde’s, humpback and southern right whales) species are targeted by the industry, and were encountered during this study. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Tolsma, Minke
- Date: 2022-04
- Subjects: Whale watching --South Africa , Dolphin watching
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55887 , vital:54397
- Description: Boat-based whale-watching (BBWW) is a rapidly growing marine tourism industry globally and in South Africa (SA). BBWW in SA was established in 1998, and since then the number of permits available has doubled from 20 to 40. However, the establishment and past growth of the industry was undertaken without ecological research or impact assessments. Global research has shown that BBWW has the potential to cause short-term changes in cetacean behaviour and movement, which in turn can have long-term population-level consequences. National policies to grow ocean economies in SA may encourage excessive growth in the BBWW industry, impacting the ecological sustainability. In the absence of long-term impact data, the BBWW industry should be managed to minimise short-term changes. This study aimed to determine the social and ecological status of the SA BBWW industry, using Plettenberg Bay as a case study, to inform its long term sustainability. To achieve this aim: 1) the short-term behavioural and movement responses of six cetacean species to encounters with commercial BBWW vessels were measured; 2) the efficacy of three permit regulations (approach speed, approach angle, and encounter duration) to prevent short-term behavioural changes in three cetacean species was measured; 3) rates of compliance of BBWWoperators with current regulations were recorded; 4) BBWW tourists’ expectations of and satisfaction with the industry were investigated; as well as 5) operators’ views on the current permit regulations of the industry All research was conducted between September 2018 and November 2020 in Plettenberg Bay (SA) where two BBWW companies operating two vessels each are active. Three dolphin (bottlenose, common and humpback dolphins) and three whale (Bryde’s, humpback and southern right whales) species are targeted by the industry, and were encountered during this study. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-04
An ethnographic exploration of black lesbians rape survivors’ access to support services in Cape Town South Africa
- Wilson, Kaythrine Esther Jacqueline
- Authors: Wilson, Kaythrine Esther Jacqueline
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/232646 , vital:50010
- Description: Thesis (PhD) -- Faculty of Humanities, Sociology, 2022
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- Date Issued: 2022-04
- Authors: Wilson, Kaythrine Esther Jacqueline
- Date: 2022-04
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/232646 , vital:50010
- Description: Thesis (PhD) -- Faculty of Humanities, Sociology, 2022
- Full Text:
- Date Issued: 2022-04
Cape Vultures (Gyps coprotheres) and the threat of wind farms: a race to extinction?
- Authors: Brooke, Francis Rae
- Date: 2022-04
- Subjects: Wind Turbines --Blades --Materials , Gyps --South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55910 , vital:54399
- Description: The development of wind energy is increasing globally and is often considered more environmentally friendly when compared to fossil fuel technologies. However, one of the ecological drawbacks of wind energy are the collisions of wildlife with turbine blades. In addition, the resulting anthropogenic landscape transformation can negatively impact populations. The Cape Vulture (Gyps coprotheres), a large endangered southern African endemic species, thus may be at risk from turbine development. The species has decreased dramatically in the past 50 years and understanding how additional mortalities from wind turbine impacts affect the population is needed to ensure effective conservation efforts. This study aimed to determine the population response to this emerging threat. This study first reviewed the species-, site- and wind farm- specific traits that make Gyps species vulnerable to collision with wind energy infrastructure. It examined the monitoring practices employed during the pre- and post-construction phase and mitigation measures in South Africa and compared it with international standards. Furthermore, wind energy development may disrupt landscape connectivity and understanding which, and how habitat patches are used is needed. Using network theory combined with telemetry data from tagged individuals across three age classes, habitat patch use was identified. Further, environmental variables associated with identified habitat patches were identified. Additionally, considering the wind energy industry is expanding in South Africa, exploring how the Cape Vulture population will respond to this novel and emerging threat may aid future conservation management plans. Therefore, using a population viability analysis approach, the study explored how present and future wind turbine mortality scenarios impact the Cape Vulture population and how the population will respond to increased wind turbine development. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Brooke, Francis Rae
- Date: 2022-04
- Subjects: Wind Turbines --Blades --Materials , Gyps --South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55910 , vital:54399
- Description: The development of wind energy is increasing globally and is often considered more environmentally friendly when compared to fossil fuel technologies. However, one of the ecological drawbacks of wind energy are the collisions of wildlife with turbine blades. In addition, the resulting anthropogenic landscape transformation can negatively impact populations. The Cape Vulture (Gyps coprotheres), a large endangered southern African endemic species, thus may be at risk from turbine development. The species has decreased dramatically in the past 50 years and understanding how additional mortalities from wind turbine impacts affect the population is needed to ensure effective conservation efforts. This study aimed to determine the population response to this emerging threat. This study first reviewed the species-, site- and wind farm- specific traits that make Gyps species vulnerable to collision with wind energy infrastructure. It examined the monitoring practices employed during the pre- and post-construction phase and mitigation measures in South Africa and compared it with international standards. Furthermore, wind energy development may disrupt landscape connectivity and understanding which, and how habitat patches are used is needed. Using network theory combined with telemetry data from tagged individuals across three age classes, habitat patch use was identified. Further, environmental variables associated with identified habitat patches were identified. Additionally, considering the wind energy industry is expanding in South Africa, exploring how the Cape Vulture population will respond to this novel and emerging threat may aid future conservation management plans. Therefore, using a population viability analysis approach, the study explored how present and future wind turbine mortality scenarios impact the Cape Vulture population and how the population will respond to increased wind turbine development. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-04
Chemical analysis of selected Eastern Cape medicinal plants
- Authors: Mahanjana, Lungelwa
- Date: 2022-04
- Subjects: Medicinal plants -- South Africa --Eastern Cape , Traditional medicine --South Africa -- Eastern Cape Maps
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55976 , vital:54560
- Description: In the rural parts of the Eastern Cape Province of South Africa, the use of medicinal plants to treat or manage diseases, including those associated with diabetes and HIV, is a common practice. However, the phytochemistry, safety and efficacy of these medicinal plants remain less investigated. Based on available traditional medicinal knowledge (through traditional healers, university library resources, ethnobotanical and science journals and other internet resources), traditional uses and availability, three plant species, namely Bulbine latifolia L. Wild, Dicerothamnus rhinocerotis Koek. and Olea europaea subsp. africana (Mill.) P.S. Green were selected and investigated for their hytoconstituents and biological effects. Phytochemical screening of the three medicinal plants was carried out quantitatively and qualitatively using spectrophotometric methods. Chemical profiling of the crude methanol extracts of all the plant species was successfully done by high-performance thin layer chromatography (HPTLC) and tentative identification of the secondary metabolites was achieved by liquid chromatography–mass spectrometry (LCMS). Cytotoxicity effect investigations on the crude extracts of the three species was done using the 3-[4,5- dimethylthiazole-2-yl]-2,5- hiphenyltetrazolium bromide (MTT) assay against HeLa cervical cancer cells. Isolation and purification of single compounds was done using chromatographic techniques (column chromatography (CC), and preparative thin-layer chromatography (PTLC)). Characterisation of single compounds was achieved using spectroscopic techniques such as Nuclear Magnetic Resonance (NMR), High Resolution Mass Spectrometry (HRMS), Ultra Violet Spectroscopy (UV-vis), Fourier-Transformed Infra-Red Spectroscopy (FTIR) and Single-Crystal X-ray Diffraction (XRD). For the first time from the methanol crude extract of the tubers of B. latifolia, the crystal structure of the phenylanthraquinone, knipholone (3.12) (1-(3-acetyl-2,6- dihydroxy-4- methoxyphenyl)-4,5-dihydroxy-2-methylanthraquinone), was isolated and elucidated along with its derivatives, isoknipholone (3.14), knipholone-6’-methyl (3.27). Moreover, two new compounds, (M)-8-O-β-D-glucopyranosyl-10’-α-L-rhamnopyranosyl-1,1',8',10'-tetrahydroxy 3,3'-dimethyl-[10,7'-bianthracene]-4,9,9'(10'H)-trione (3.23a) and (P)- 8-O-β-D glucopyranosyl-10’-α-L-rhamnopyranosyl-1,1',8',10'-tetrahydroxy-3,3'-dimethyl-[10,7'- bianthracene]-4,9,9'(10'H)-trione (3.23b) were isolated. , Thesis (PhD) -- Faculty of Science, School of Biomecular and Chemical Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Mahanjana, Lungelwa
- Date: 2022-04
- Subjects: Medicinal plants -- South Africa --Eastern Cape , Traditional medicine --South Africa -- Eastern Cape Maps
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/55976 , vital:54560
- Description: In the rural parts of the Eastern Cape Province of South Africa, the use of medicinal plants to treat or manage diseases, including those associated with diabetes and HIV, is a common practice. However, the phytochemistry, safety and efficacy of these medicinal plants remain less investigated. Based on available traditional medicinal knowledge (through traditional healers, university library resources, ethnobotanical and science journals and other internet resources), traditional uses and availability, three plant species, namely Bulbine latifolia L. Wild, Dicerothamnus rhinocerotis Koek. and Olea europaea subsp. africana (Mill.) P.S. Green were selected and investigated for their hytoconstituents and biological effects. Phytochemical screening of the three medicinal plants was carried out quantitatively and qualitatively using spectrophotometric methods. Chemical profiling of the crude methanol extracts of all the plant species was successfully done by high-performance thin layer chromatography (HPTLC) and tentative identification of the secondary metabolites was achieved by liquid chromatography–mass spectrometry (LCMS). Cytotoxicity effect investigations on the crude extracts of the three species was done using the 3-[4,5- dimethylthiazole-2-yl]-2,5- hiphenyltetrazolium bromide (MTT) assay against HeLa cervical cancer cells. Isolation and purification of single compounds was done using chromatographic techniques (column chromatography (CC), and preparative thin-layer chromatography (PTLC)). Characterisation of single compounds was achieved using spectroscopic techniques such as Nuclear Magnetic Resonance (NMR), High Resolution Mass Spectrometry (HRMS), Ultra Violet Spectroscopy (UV-vis), Fourier-Transformed Infra-Red Spectroscopy (FTIR) and Single-Crystal X-ray Diffraction (XRD). For the first time from the methanol crude extract of the tubers of B. latifolia, the crystal structure of the phenylanthraquinone, knipholone (3.12) (1-(3-acetyl-2,6- dihydroxy-4- methoxyphenyl)-4,5-dihydroxy-2-methylanthraquinone), was isolated and elucidated along with its derivatives, isoknipholone (3.14), knipholone-6’-methyl (3.27). Moreover, two new compounds, (M)-8-O-β-D-glucopyranosyl-10’-α-L-rhamnopyranosyl-1,1',8',10'-tetrahydroxy 3,3'-dimethyl-[10,7'-bianthracene]-4,9,9'(10'H)-trione (3.23a) and (P)- 8-O-β-D glucopyranosyl-10’-α-L-rhamnopyranosyl-1,1',8',10'-tetrahydroxy-3,3'-dimethyl-[10,7'- bianthracene]-4,9,9'(10'H)-trione (3.23b) were isolated. , Thesis (PhD) -- Faculty of Science, School of Biomecular and Chemical Sciences, 2022
- Full Text:
- Date Issued: 2022-04
Constructing an online serviceScape for the funeral industry
- Authors: Coetzee, Cornelis Albertus
- Date: 2022-04
- Subjects: Funeral supplies industry , Funeral service , Service industries -- Marketing
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/57611 , vital:58186
- Description: An online servicescape serves as a moderator for excellence in Customer Relationship Management (CRM). The study approached the online servicescape from the perspective of the funeral industry. Nowhere is the relevance of an online servicescape more apparent than in an industry which is firstly, unsought, and secondly, perceived as dismal. During the process of arranging a funeral, the customer is experiencing an unusual purchase situation as it is a purchase that cannot be avoided. The possibility also exists that the customer most likely did not seek information about a funeral home prior to the demise of a loved one. A third contributing factor is the emotional state of the customer which will, in a time of bereavement, have a strong impact on the rational decision-making process. Considering these conditions, the study approached the online servicescape based on three elements, namely Search Engine Optimisation, perceived value, and perceived usefulness of the online servicescape. These elements contribute to trust in the funeral home’s online offerings, which could influence the purchase outcomes significantly. The aim of the study was to construct a functional servicescape for an unsought business such as a funeral home, hence contributing significantly to the CRM body of knowledge as it was determined that this has not been explored before from an academic perspective. A quantitative, exploratory methodology was implemented. The exploration is depended on Bitner's (1992a:60) seminal model of servicescapes, Harris and Goode's (2010:230-243) model for online servicescapes, and the key constructs of Simon's (1996:141-142) Design Theory to provide a methodological basis with which to construct the key elements for a funeral industry based online servicescape. The data collection process followed a twostep process. A content analysis was conducted on existing websites from five English speaking countries, followed by a survey that largely reflected the content analysis variables to gain customer insights. The data was analysed using a descriptive analysis process. v It was determined that customers would trust a functional servicescape, which will most probably lead to a purchase situation. However, customers also indicated the opposite if they detect anything on the website that might lead to distrust. It was therefore concluded that it is imperative for a funeral home to ensure that their online servicescape meets the functional needs of customers in order ensure trust and purchase intention. , Thesis (PhD) -- Faculty of Business and Economic science, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Coetzee, Cornelis Albertus
- Date: 2022-04
- Subjects: Funeral supplies industry , Funeral service , Service industries -- Marketing
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/57611 , vital:58186
- Description: An online servicescape serves as a moderator for excellence in Customer Relationship Management (CRM). The study approached the online servicescape from the perspective of the funeral industry. Nowhere is the relevance of an online servicescape more apparent than in an industry which is firstly, unsought, and secondly, perceived as dismal. During the process of arranging a funeral, the customer is experiencing an unusual purchase situation as it is a purchase that cannot be avoided. The possibility also exists that the customer most likely did not seek information about a funeral home prior to the demise of a loved one. A third contributing factor is the emotional state of the customer which will, in a time of bereavement, have a strong impact on the rational decision-making process. Considering these conditions, the study approached the online servicescape based on three elements, namely Search Engine Optimisation, perceived value, and perceived usefulness of the online servicescape. These elements contribute to trust in the funeral home’s online offerings, which could influence the purchase outcomes significantly. The aim of the study was to construct a functional servicescape for an unsought business such as a funeral home, hence contributing significantly to the CRM body of knowledge as it was determined that this has not been explored before from an academic perspective. A quantitative, exploratory methodology was implemented. The exploration is depended on Bitner's (1992a:60) seminal model of servicescapes, Harris and Goode's (2010:230-243) model for online servicescapes, and the key constructs of Simon's (1996:141-142) Design Theory to provide a methodological basis with which to construct the key elements for a funeral industry based online servicescape. The data collection process followed a twostep process. A content analysis was conducted on existing websites from five English speaking countries, followed by a survey that largely reflected the content analysis variables to gain customer insights. The data was analysed using a descriptive analysis process. v It was determined that customers would trust a functional servicescape, which will most probably lead to a purchase situation. However, customers also indicated the opposite if they detect anything on the website that might lead to distrust. It was therefore concluded that it is imperative for a funeral home to ensure that their online servicescape meets the functional needs of customers in order ensure trust and purchase intention. , Thesis (PhD) -- Faculty of Business and Economic science, 2022
- Full Text:
- Date Issued: 2022-04