Double-and quintuple-decker phthalocyaninato chelates as optical limiters in solution and thin film
- Sekhosana, Kutloano E, Nyokong, Tebello
- Authors: Sekhosana, Kutloano E , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186733 , vital:44529 , xlink:href="https://doi.org/10.1016/j.dyepig.2019.107836"
- Description: The rare-earth quintuple-decker phthalocyaninato chelates (3a and 3b) were synthesized from their parent rare-earth double-decker phthalocyaninato precursors (2b and 2a). After extensive structural elucidation, these complexes were subjected to various spectroscopic techniques to investigate their electronic behavior. It was found that complexes 3a and 3b existed as the oxidized forms. When investigating the optical limiting properties, all these complexes were found to exhibit reverse saturable absorption, with complex 2a showing a more enhanced open-aperture Z-Scan signature than complex 2b. Interestingly, complexes 3a and 3b (in solution) exhibited better open-aperture Z-Scan signatures than their parent rare-earth double-decker phthalocyaninato precursors (2b and 2a). However, thin films fabricated from these complexes did not show an improvement in the optical limiting properties when compared to 2a, 3a, 3b except for that which was prepared from 2b. This study shows the importance of extensive π-electron system in phthalocyaninato complexes for optical limiting applications.
- Full Text:
- Date Issued: 2020
- Authors: Sekhosana, Kutloano E , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186733 , vital:44529 , xlink:href="https://doi.org/10.1016/j.dyepig.2019.107836"
- Description: The rare-earth quintuple-decker phthalocyaninato chelates (3a and 3b) were synthesized from their parent rare-earth double-decker phthalocyaninato precursors (2b and 2a). After extensive structural elucidation, these complexes were subjected to various spectroscopic techniques to investigate their electronic behavior. It was found that complexes 3a and 3b existed as the oxidized forms. When investigating the optical limiting properties, all these complexes were found to exhibit reverse saturable absorption, with complex 2a showing a more enhanced open-aperture Z-Scan signature than complex 2b. Interestingly, complexes 3a and 3b (in solution) exhibited better open-aperture Z-Scan signatures than their parent rare-earth double-decker phthalocyaninato precursors (2b and 2a). However, thin films fabricated from these complexes did not show an improvement in the optical limiting properties when compared to 2a, 3a, 3b except for that which was prepared from 2b. This study shows the importance of extensive π-electron system in phthalocyaninato complexes for optical limiting applications.
- Full Text:
- Date Issued: 2020
Analytical Detection and Electrocatalysis of Paracetamol in Aqueous Media Using Rare‐Earth Double‐Decker Phthalocyaninato Chelates as Electrochemically Active Materials
- Sekhosana, Kutloana E, Nkhahle, Reitumetse, Nyokong, Tebello
- Authors: Sekhosana, Kutloana E , Nkhahle, Reitumetse , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190840 , vital:45033 , xlink:href="https://doi.org/10.1002/slct.202002268"
- Description: Paracetamol (PA), being an analgesic and antipyretic medicine, can cause fatal hepatotoxicity and nephrotoxicity when overdosed. It is therefore important to develop electrochemical sensors that can monitor and quantify it in aquatic environments. In this study, rare-earth sandwich-type phthalocyaninato chelates based on neodymium (1 a) and samarium (1 b) were employed as electrocatalysts to modify glassy carbon electrodes (GCE) for the first time. It was found that 1 a-modified GCE (herein referred to as 1 a-GCE) is less conductive than 1 b-modified counterpart (1 b-GCE). A larger rate constant was also obtained for 1 b-GCE. It was established that a faster oxidation rate efficiency was responsible for lower limit of detection value obtained for 1 b-GCE as compared to 1 a-GCE.
- Full Text:
- Date Issued: 2020
- Authors: Sekhosana, Kutloana E , Nkhahle, Reitumetse , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190840 , vital:45033 , xlink:href="https://doi.org/10.1002/slct.202002268"
- Description: Paracetamol (PA), being an analgesic and antipyretic medicine, can cause fatal hepatotoxicity and nephrotoxicity when overdosed. It is therefore important to develop electrochemical sensors that can monitor and quantify it in aquatic environments. In this study, rare-earth sandwich-type phthalocyaninato chelates based on neodymium (1 a) and samarium (1 b) were employed as electrocatalysts to modify glassy carbon electrodes (GCE) for the first time. It was found that 1 a-modified GCE (herein referred to as 1 a-GCE) is less conductive than 1 b-modified counterpart (1 b-GCE). A larger rate constant was also obtained for 1 b-GCE. It was established that a faster oxidation rate efficiency was responsible for lower limit of detection value obtained for 1 b-GCE as compared to 1 a-GCE.
- Full Text:
- Date Issued: 2020
Synthesis of novel heterocyclic systems as potential inhibitors of HIV-1 enzymes
- Authors: Sekgota, Khethobole Cassius
- Date: 2020
- Subjects: Protease inhibitors , Heterocyclic compounds , HIV (Viruses) , Quinoline , Amides , Nuclear magnetic resonance , Antiretroviral agents , AIDS vaccines , Nitrobenzaldehyde , Propylphosphonic acid anhydride
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146502 , vital:38531
- Description: This study has focussed on the application of Baylis-Hillman methodology in the development of efficient synthetic pathways to libraries of novel 3-[(N-cycloalkylbenzamido)methyl]-2-quinolones and indolizine-2-carboxamides and on an exploration of their medicinal potential. The approach to 3-[(N-cycloalkylbenzamido)methyl]-2(1H)-quinolones involved a six-step pathway comprising: Baylis-Hillman reaction of 2-nitrobenzaldehyde derivatives and methyl acrylate to afford nitro-Baylis-Hillman adducts; thermal cyclisation of the adducts to give a range of 3-(acetoxymethyl)-2(1H)-quinolones in good to excellent yields; hydrolysis of the acetates; conversion of the resulting alcohols to the 3-chloromethyl analogues; amination; and, finally, acylation to afford the target amides. Variable temperature NMR methods were used to facilitate analysis of the ¹H and ¹³C NMR spectra which were complicated by internal rotation and cycloalkyl ring-flipping effects. On the other hand, the indolizine-2-carboxamides were obtained in several steps commencing with the Baylis-Hillman reaction of pyridine-2-carboxaldehyde and methyl acrylate. Thermal cyclisation of the Baylis-Hillman adduct afforded indolizine esters, hydrolysis of which gave the corresponding acids which served as precursors to the target indolizine-2-carboxamides. The final amidation step, however, proved to be particularly challenging. Various coupling strategies were explored to access indolizine-2-carboxamides. These included the use of 2,2,2-trifluoroethyl borate which showed limited promise, but propylphosphonic acid anhydride (T3P) proved to be the most effective coupling agent, permitting the formation of 24 novel indolizine-2-carboxamides from hydrazines, aliphatic amines and a range of heterocyclic amines. A high-field NMR-based kinetic study of the mechanism of the Baylis-Hillman reaction of pyridine-4-carboxaldehyde and methyl acrylate in the presence of 3-hydroxyquinuclidine in deuterated chloroform was initiated, reaction progress being followed by the automated collection of ¹H and DEPT 135 NMR spectra over ca. 24 hours using a high-field (600 MHz) NMR instrument. The results have provided critical new insights into the mechanism. NMR analysis has also been used to elucidate the multiplicity of signals associated with rotameric equilibria observed at ambient probe temperature. Variable temperature 1D- and 2D-NMR spectra were used to facilitate the unambiguous characterisation of the 2-quinolone benzamides and some of the indolizine-2-carboxamides. The 3-[(N-cycloalkylbenzamido)methyl]-2(1H)-quinolones, together with selected precursors, and a number of the indolizine-2-carboxamides have been screened in vitro as potential HIV-1 enzyme inhibitors. A survey of the activity of the 2-quinolones against HIV-1 integrase, protease and reverse transcriptase revealed selective inhibition of HIV-1 integrase with the most active IN inhibitor, 3-[(cyclopentylamino)methyl-6-methoxy-2(1H)-quinolone 115e, producing residual enzyme activity of 40% at a concentration of 20 μM. Many of the 2-quinolones exhibited no significant cytotoxicity against HEK 293 cells at 20 μM concentrations. 3-[(N-Cyclohexylamino)methyl]-6-methoxy-2(1H)-quinolone 114e was the only compound to exhibit ant-plasmodial activity (55% pfLDH activity). The survey of indolizine-2-carboxamides also revealed encouraging inhibition against HIV-1 integrase. None of these compounds exhibited cytotoxicity at 20 μM against HEK 293 cells, while a number of them exhibited some activity against Plasmodium falciparum (3D7 strain) and Trypanosoma brucei. Selected indolizine-2-carboxamides exhibited significant anti-tubercular activity in the 7H9 CAS GLU Tx and 7H9 ADC GLU Tw media. In view of the inherent fluorescent character and biological potential of the synthesised indolizine-2-carboxamides, their photophysical properties were explored to establish their possible dual use as bio-imaging and therapeutic agents. The major absorption and corresponding emission bands, and the associated molar absorption coefficients (Ɛ) expressed in the form of log Ɛ were determined. Their high extinction coefficients, large Stokes shift and red-shifted emissions in the visible region indicate their potential for use as fluorophores.
- Full Text:
- Date Issued: 2020
- Authors: Sekgota, Khethobole Cassius
- Date: 2020
- Subjects: Protease inhibitors , Heterocyclic compounds , HIV (Viruses) , Quinoline , Amides , Nuclear magnetic resonance , Antiretroviral agents , AIDS vaccines , Nitrobenzaldehyde , Propylphosphonic acid anhydride
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146502 , vital:38531
- Description: This study has focussed on the application of Baylis-Hillman methodology in the development of efficient synthetic pathways to libraries of novel 3-[(N-cycloalkylbenzamido)methyl]-2-quinolones and indolizine-2-carboxamides and on an exploration of their medicinal potential. The approach to 3-[(N-cycloalkylbenzamido)methyl]-2(1H)-quinolones involved a six-step pathway comprising: Baylis-Hillman reaction of 2-nitrobenzaldehyde derivatives and methyl acrylate to afford nitro-Baylis-Hillman adducts; thermal cyclisation of the adducts to give a range of 3-(acetoxymethyl)-2(1H)-quinolones in good to excellent yields; hydrolysis of the acetates; conversion of the resulting alcohols to the 3-chloromethyl analogues; amination; and, finally, acylation to afford the target amides. Variable temperature NMR methods were used to facilitate analysis of the ¹H and ¹³C NMR spectra which were complicated by internal rotation and cycloalkyl ring-flipping effects. On the other hand, the indolizine-2-carboxamides were obtained in several steps commencing with the Baylis-Hillman reaction of pyridine-2-carboxaldehyde and methyl acrylate. Thermal cyclisation of the Baylis-Hillman adduct afforded indolizine esters, hydrolysis of which gave the corresponding acids which served as precursors to the target indolizine-2-carboxamides. The final amidation step, however, proved to be particularly challenging. Various coupling strategies were explored to access indolizine-2-carboxamides. These included the use of 2,2,2-trifluoroethyl borate which showed limited promise, but propylphosphonic acid anhydride (T3P) proved to be the most effective coupling agent, permitting the formation of 24 novel indolizine-2-carboxamides from hydrazines, aliphatic amines and a range of heterocyclic amines. A high-field NMR-based kinetic study of the mechanism of the Baylis-Hillman reaction of pyridine-4-carboxaldehyde and methyl acrylate in the presence of 3-hydroxyquinuclidine in deuterated chloroform was initiated, reaction progress being followed by the automated collection of ¹H and DEPT 135 NMR spectra over ca. 24 hours using a high-field (600 MHz) NMR instrument. The results have provided critical new insights into the mechanism. NMR analysis has also been used to elucidate the multiplicity of signals associated with rotameric equilibria observed at ambient probe temperature. Variable temperature 1D- and 2D-NMR spectra were used to facilitate the unambiguous characterisation of the 2-quinolone benzamides and some of the indolizine-2-carboxamides. The 3-[(N-cycloalkylbenzamido)methyl]-2(1H)-quinolones, together with selected precursors, and a number of the indolizine-2-carboxamides have been screened in vitro as potential HIV-1 enzyme inhibitors. A survey of the activity of the 2-quinolones against HIV-1 integrase, protease and reverse transcriptase revealed selective inhibition of HIV-1 integrase with the most active IN inhibitor, 3-[(cyclopentylamino)methyl-6-methoxy-2(1H)-quinolone 115e, producing residual enzyme activity of 40% at a concentration of 20 μM. Many of the 2-quinolones exhibited no significant cytotoxicity against HEK 293 cells at 20 μM concentrations. 3-[(N-Cyclohexylamino)methyl]-6-methoxy-2(1H)-quinolone 114e was the only compound to exhibit ant-plasmodial activity (55% pfLDH activity). The survey of indolizine-2-carboxamides also revealed encouraging inhibition against HIV-1 integrase. None of these compounds exhibited cytotoxicity at 20 μM against HEK 293 cells, while a number of them exhibited some activity against Plasmodium falciparum (3D7 strain) and Trypanosoma brucei. Selected indolizine-2-carboxamides exhibited significant anti-tubercular activity in the 7H9 CAS GLU Tx and 7H9 ADC GLU Tw media. In view of the inherent fluorescent character and biological potential of the synthesised indolizine-2-carboxamides, their photophysical properties were explored to establish their possible dual use as bio-imaging and therapeutic agents. The major absorption and corresponding emission bands, and the associated molar absorption coefficients (Ɛ) expressed in the form of log Ɛ were determined. Their high extinction coefficients, large Stokes shift and red-shifted emissions in the visible region indicate their potential for use as fluorophores.
- Full Text:
- Date Issued: 2020
The small pelagic fishery of the Pemba Channel, Tanzania: What we know and what we need to know for management under climate change
- Sekadende, Baraka, Scott, Lucy, Anderson, Jim, Shankar, Aswani, Francis, Julius, Jacobs, Zoe, Jebri, Fatma, Jiddawi, Narriman, Kamukuru, Albogast T, Kelly, Stephen, Kizenga, Hellen, Kuguru, Baraka, Kyewalyanga, Margareth, Noyon, Margaux, Nyandwi, Ntahondi, Painter, Stuart C, Palmer, Matthew, Raitsos, Dionysios E, Roberts, Michael, Sailley, Sévrine F, Samoilys, Melita, Sauer, Warwick, Shayo, Salome, Shaghude, Yohan, Taylor, Sarah F, Wihsgott, Juliane, Popova, Ekaterina
- Authors: Sekadende, Baraka , Scott, Lucy , Anderson, Jim , Shankar, Aswani , Francis, Julius , Jacobs, Zoe , Jebri, Fatma , Jiddawi, Narriman , Kamukuru, Albogast T , Kelly, Stephen , Kizenga, Hellen , Kuguru, Baraka , Kyewalyanga, Margareth , Noyon, Margaux , Nyandwi, Ntahondi , Painter, Stuart C , Palmer, Matthew , Raitsos, Dionysios E , Roberts, Michael , Sailley, Sévrine F , Samoilys, Melita , Sauer, Warwick , Shayo, Salome , Shaghude, Yohan , Taylor, Sarah F , Wihsgott, Juliane , Popova, Ekaterina
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406570 , vital:70286 , xlink:href="https://doi.org/10.1016/j.ocecoaman.2020.105322"
- Description: Small pelagic fish, including anchovies, sardines and sardinellas, mackerels, capelin, hilsa, sprats and herrings, are distributed widely, from the tropics to the far north Atlantic Ocean and to the southern oceans off Chile and South Africa. They are most abundant in the highly productive major eastern boundary upwelling systems and are characterised by significant natural variations in biomass. Overall, small pelagic fisheries represent about one third of global fish landings although a large proportion of the catch is processed into animal feeds. Nonetheless, in some developing countries in addition to their economic value, small pelagic fisheries also make an important contribution to human diets and the food security of many low-income households. Such is the case for many communities in the Zanzibar Archipelago and on mainland Tanzania in the Western Indian Ocean. Of great concern in this region, as elsewhere, is the potential impact of climate change on marine and coastal ecosystems in general, and on small pelagic fisheries in particular. This paper describes data and information available on Tanzania's small pelagic fisheries, including catch and effort, management protocols and socio-economic significance. Then, incorporating the rapidly improving understanding of the region's oceanography resulting from the application of remote sensing and oceanographic modelling, the paper undertakes the most complete assessment to date of the potential impacts of climate change on the small pelagic fishery of the Pemba Channel. Pathways of climate change impact are explored and crucial knowledge gaps, both in terms of the fishery itself and the wider ecosystem, are identified in order to guide future research activities. Although we analyse small pelagics in the specific context of the Pemba Channel, the key challenges identified in the analysis are likely to be relevant to many small pelagic fisheries in coastal nations heavily dependent on living marine resources.
- Full Text:
- Date Issued: 2020
- Authors: Sekadende, Baraka , Scott, Lucy , Anderson, Jim , Shankar, Aswani , Francis, Julius , Jacobs, Zoe , Jebri, Fatma , Jiddawi, Narriman , Kamukuru, Albogast T , Kelly, Stephen , Kizenga, Hellen , Kuguru, Baraka , Kyewalyanga, Margareth , Noyon, Margaux , Nyandwi, Ntahondi , Painter, Stuart C , Palmer, Matthew , Raitsos, Dionysios E , Roberts, Michael , Sailley, Sévrine F , Samoilys, Melita , Sauer, Warwick , Shayo, Salome , Shaghude, Yohan , Taylor, Sarah F , Wihsgott, Juliane , Popova, Ekaterina
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406570 , vital:70286 , xlink:href="https://doi.org/10.1016/j.ocecoaman.2020.105322"
- Description: Small pelagic fish, including anchovies, sardines and sardinellas, mackerels, capelin, hilsa, sprats and herrings, are distributed widely, from the tropics to the far north Atlantic Ocean and to the southern oceans off Chile and South Africa. They are most abundant in the highly productive major eastern boundary upwelling systems and are characterised by significant natural variations in biomass. Overall, small pelagic fisheries represent about one third of global fish landings although a large proportion of the catch is processed into animal feeds. Nonetheless, in some developing countries in addition to their economic value, small pelagic fisheries also make an important contribution to human diets and the food security of many low-income households. Such is the case for many communities in the Zanzibar Archipelago and on mainland Tanzania in the Western Indian Ocean. Of great concern in this region, as elsewhere, is the potential impact of climate change on marine and coastal ecosystems in general, and on small pelagic fisheries in particular. This paper describes data and information available on Tanzania's small pelagic fisheries, including catch and effort, management protocols and socio-economic significance. Then, incorporating the rapidly improving understanding of the region's oceanography resulting from the application of remote sensing and oceanographic modelling, the paper undertakes the most complete assessment to date of the potential impacts of climate change on the small pelagic fishery of the Pemba Channel. Pathways of climate change impact are explored and crucial knowledge gaps, both in terms of the fishery itself and the wider ecosystem, are identified in order to guide future research activities. Although we analyse small pelagics in the specific context of the Pemba Channel, the key challenges identified in the analysis are likely to be relevant to many small pelagic fisheries in coastal nations heavily dependent on living marine resources.
- Full Text:
- Date Issued: 2020
The small pelagic fishery of the Pemba Channel, Tanzania: what we know and what we need to know for management under climate change
- Sekadende, Baraka, Scott, Lucy E P, Anderson, Jim, Aswani, Shankar, Francis, Julius, Jacobs, Zoe, Jebri, Fatma, Jiddawi, Narriman, Kamukuru, Albogast T, Kelly, Stephen, Kizenga, Hellen, Kuguru, Baraka, Kyewalyanga, Margareth, Noyon, Margaux, Nyandwi, Ntahondi, Painter, Stuart C, Palmer, Matthew, Raitsos, Dionysios, Roberts, Michael, Sailley, Sévrine F, Samoilys, Melita, Sauer, Warwick H H, Shayo, Salome, Shaghude, Yohana, Taylor, Sarah F W, Wihsgott, Juliane, Ekaterina Popova
- Authors: Sekadende, Baraka , Scott, Lucy E P , Anderson, Jim , Aswani, Shankar , Francis, Julius , Jacobs, Zoe , Jebri, Fatma , Jiddawi, Narriman , Kamukuru, Albogast T , Kelly, Stephen , Kizenga, Hellen , Kuguru, Baraka , Kyewalyanga, Margareth , Noyon, Margaux , Nyandwi, Ntahondi , Painter, Stuart C , Palmer, Matthew , Raitsos, Dionysios , Roberts, Michael , Sailley, Sévrine F , Samoilys, Melita , Sauer, Warwick H H , Shayo, Salome , Shaghude, Yohana , Taylor, Sarah F W , Wihsgott, Juliane , Ekaterina Popova
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/178986 , vital:40102 , https://doi.org/10.1016/j.ocecoaman.2020.105322
- Description: Small pelagic fish, including anchovies, sardines and sardinellas, mackerels, capelin, hilsa, sprats and herrings, are distributed widely, from the tropics to the far north Atlantic Ocean and to the southern oceans off Chile and South Africa. They are most abundant in the highly productive major eastern boundary upwelling systems and are characterised by significant natural variations in biomass. Overall, small pelagic fisheries represent about one third of global fish landings although a large proportion of the catch is processed into animal feeds. Nonetheless, in some developing countries in addition to their economic value, small pelagic fisheries also make an important contribution to human diets and the food security of many low-income households. Such is the case for many communities in the Zanzibar Archipelago and on mainland Tanzania in the Western Indian Ocean. Of great concern in this region, as elsewhere, is the potential impact of climate change on marine and coastal ecosystems in general, and on small pelagic fisheries in particular. This paper describes data and information available on Tanzania's small pelagic fisheries, including catch and effort, management protocols and socio-economic significance.
- Full Text:
- Date Issued: 2020
- Authors: Sekadende, Baraka , Scott, Lucy E P , Anderson, Jim , Aswani, Shankar , Francis, Julius , Jacobs, Zoe , Jebri, Fatma , Jiddawi, Narriman , Kamukuru, Albogast T , Kelly, Stephen , Kizenga, Hellen , Kuguru, Baraka , Kyewalyanga, Margareth , Noyon, Margaux , Nyandwi, Ntahondi , Painter, Stuart C , Palmer, Matthew , Raitsos, Dionysios , Roberts, Michael , Sailley, Sévrine F , Samoilys, Melita , Sauer, Warwick H H , Shayo, Salome , Shaghude, Yohana , Taylor, Sarah F W , Wihsgott, Juliane , Ekaterina Popova
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/178986 , vital:40102 , https://doi.org/10.1016/j.ocecoaman.2020.105322
- Description: Small pelagic fish, including anchovies, sardines and sardinellas, mackerels, capelin, hilsa, sprats and herrings, are distributed widely, from the tropics to the far north Atlantic Ocean and to the southern oceans off Chile and South Africa. They are most abundant in the highly productive major eastern boundary upwelling systems and are characterised by significant natural variations in biomass. Overall, small pelagic fisheries represent about one third of global fish landings although a large proportion of the catch is processed into animal feeds. Nonetheless, in some developing countries in addition to their economic value, small pelagic fisheries also make an important contribution to human diets and the food security of many low-income households. Such is the case for many communities in the Zanzibar Archipelago and on mainland Tanzania in the Western Indian Ocean. Of great concern in this region, as elsewhere, is the potential impact of climate change on marine and coastal ecosystems in general, and on small pelagic fisheries in particular. This paper describes data and information available on Tanzania's small pelagic fisheries, including catch and effort, management protocols and socio-economic significance.
- Full Text:
- Date Issued: 2020
A systematic review of the efficacy of internet-based interventions for depression and anxiety disorders: the possibilities and limitations for feasibility within South Africa
- Authors: Sealy-Fisher, Kay Tibeta
- Date: 2020
- Subjects: Depression, Mental -- Treatment -- South Africa , Anxiety disorders -- Treatment -- South Africa , Internet in psychotherapy -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/144632 , vital:38364
- Description: Technological advances may alleviate the burden on South Africa’s mental healthcare system. This study is a systematic review of literature that assesses the efficacy of high quality online interventions for depression and anxiety, and that compares the reviewed studies’ characteristics to the South African context to assist in future developments of online interventions for depression and anxiety within South Africa. This was achieved through using a 2010 systematic review of Griffiths, Farrer, and Christensen as point of departure. This research had two aims: to provide an updated systematic review of the literature reporting on the efficacy of internet-based interventions for depression and anxiety disorders; and to evaluate the possibilities and limitations for the feasibility of implementing internet-based interventions for depression and anxiety disorders in the South African context. Databases accessed were PubMed, PsycINFO, and Cochrane Central Register of Controlled Trials. Included studies must: (i) report on one or more internet-based intervention, (ii) target depression or anxiety or both, (iii) report the effect size or provide enough information to calculate it, (iv) report a measure of symptoms outcome, (v) be a Randomised Controlled Trial, (vi) include a control group that received no active intervention, (vii) be published and peer-reviewed, (viii) have been published after January 2010. The search yielded 2999 potential studies of which 20 full texts were reviewed. Of these, 75% (n=15) of the studies report effect sizes above 0.20, and 25% (n=5) of the studies report effect sizes above 0.80. Themes emergent from literature and included studies distinguished effective from non-effective studies included the use of cognitive behavioural therapy, therapist input and reminders to engage with the intervention, and duration of over 6 weeks. Attrition rates did not differ between experimental and control groups. Sample characteristics between the reviewed interventions and South Africa’s population were found to be different and is discussed. Unfortunately, 37 potential studies could not be accessed and thus not included, although several attempts were made. The majority of studies had effect sizes equal to that of face-to-face therapeutic interventions. Implications of application in South Africa’s context with limited technological familiarity, insufficiency of professionally trained therapists, poor literacy, and high costs of internet data are discussed. It is concluded that with appropriate adaptation, online internet interventions for depression and anxiety would be beneficial to South Africa’s people and assist in lowering the country’s burden of mental health disorders.
- Full Text:
- Date Issued: 2020
- Authors: Sealy-Fisher, Kay Tibeta
- Date: 2020
- Subjects: Depression, Mental -- Treatment -- South Africa , Anxiety disorders -- Treatment -- South Africa , Internet in psychotherapy -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/144632 , vital:38364
- Description: Technological advances may alleviate the burden on South Africa’s mental healthcare system. This study is a systematic review of literature that assesses the efficacy of high quality online interventions for depression and anxiety, and that compares the reviewed studies’ characteristics to the South African context to assist in future developments of online interventions for depression and anxiety within South Africa. This was achieved through using a 2010 systematic review of Griffiths, Farrer, and Christensen as point of departure. This research had two aims: to provide an updated systematic review of the literature reporting on the efficacy of internet-based interventions for depression and anxiety disorders; and to evaluate the possibilities and limitations for the feasibility of implementing internet-based interventions for depression and anxiety disorders in the South African context. Databases accessed were PubMed, PsycINFO, and Cochrane Central Register of Controlled Trials. Included studies must: (i) report on one or more internet-based intervention, (ii) target depression or anxiety or both, (iii) report the effect size or provide enough information to calculate it, (iv) report a measure of symptoms outcome, (v) be a Randomised Controlled Trial, (vi) include a control group that received no active intervention, (vii) be published and peer-reviewed, (viii) have been published after January 2010. The search yielded 2999 potential studies of which 20 full texts were reviewed. Of these, 75% (n=15) of the studies report effect sizes above 0.20, and 25% (n=5) of the studies report effect sizes above 0.80. Themes emergent from literature and included studies distinguished effective from non-effective studies included the use of cognitive behavioural therapy, therapist input and reminders to engage with the intervention, and duration of over 6 weeks. Attrition rates did not differ between experimental and control groups. Sample characteristics between the reviewed interventions and South Africa’s population were found to be different and is discussed. Unfortunately, 37 potential studies could not be accessed and thus not included, although several attempts were made. The majority of studies had effect sizes equal to that of face-to-face therapeutic interventions. Implications of application in South Africa’s context with limited technological familiarity, insufficiency of professionally trained therapists, poor literacy, and high costs of internet data are discussed. It is concluded that with appropriate adaptation, online internet interventions for depression and anxiety would be beneficial to South Africa’s people and assist in lowering the country’s burden of mental health disorders.
- Full Text:
- Date Issued: 2020
Psychologists’ perceptions of cultural competence in working with clients from diverse cultures in psychotherapy within the Nelson Mandela Bay area
- Authors: Sdinane, Thembeka Gloria
- Date: 2020
- Subjects: Cultural competence
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/46453 , vital:39597
- Description: There has beenanincreasedacknowledgement of the need for current psychological interventions to meet the needs of the diverse cultural contexts reflective of the SouthAfrican clients. As such, researchers began exploring, enhancing,and evaluating modelsof psychotherapy, applicable to the cultures of the diverse clients. To address disparities caused by Eurocentricepistemologies that fail to recognise the impact of culture on clients, the concept of cultural competence was introduced.While there is international literature available on cultural competence in psychotherapy, there is still a significant gap in South African literature.Consequently, this study explored psychologists’ perceptions of cultural competence when working with diverse clients in psychotherapy. A general exploratory qualitative approach informed this study. The qualitative data was collected using semi-structured interviews. Using a purposive sampling strategy, registered clinical and counselling psychologists who are in private practice were selected. A total of 6 participants were interviewed.The interviews were transcribed verbatim, and the thematic analysis method was used to analyse data with aid from the Atlas.ti coding Software. Findings of this study are presented using the four identified themes i) Complexities of working with diverse cultures, ii) knowledge limitation hinders complete cultural competence, iii) Actions towards cultural competence and iv) The geographical context. The findings of this study suggest that the idea of complete cultural competence in psychological therapyis not plausible, given the nuances embedded within South African society. As such, the researcher suggests a move from cultural competence to cultural effectiveness as an alternative that could potentially create aplatform that bridges the gap between psychological science and the nuances posed by cultures.
- Full Text:
- Date Issued: 2020
- Authors: Sdinane, Thembeka Gloria
- Date: 2020
- Subjects: Cultural competence
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/46453 , vital:39597
- Description: There has beenanincreasedacknowledgement of the need for current psychological interventions to meet the needs of the diverse cultural contexts reflective of the SouthAfrican clients. As such, researchers began exploring, enhancing,and evaluating modelsof psychotherapy, applicable to the cultures of the diverse clients. To address disparities caused by Eurocentricepistemologies that fail to recognise the impact of culture on clients, the concept of cultural competence was introduced.While there is international literature available on cultural competence in psychotherapy, there is still a significant gap in South African literature.Consequently, this study explored psychologists’ perceptions of cultural competence when working with diverse clients in psychotherapy. A general exploratory qualitative approach informed this study. The qualitative data was collected using semi-structured interviews. Using a purposive sampling strategy, registered clinical and counselling psychologists who are in private practice were selected. A total of 6 participants were interviewed.The interviews were transcribed verbatim, and the thematic analysis method was used to analyse data with aid from the Atlas.ti coding Software. Findings of this study are presented using the four identified themes i) Complexities of working with diverse cultures, ii) knowledge limitation hinders complete cultural competence, iii) Actions towards cultural competence and iv) The geographical context. The findings of this study suggest that the idea of complete cultural competence in psychological therapyis not plausible, given the nuances embedded within South African society. As such, the researcher suggests a move from cultural competence to cultural effectiveness as an alternative that could potentially create aplatform that bridges the gap between psychological science and the nuances posed by cultures.
- Full Text:
- Date Issued: 2020
Geotourism, iconic landforms and island-style speciation patterns in National Parks of East Africa:
- Authors: Scoon, Roger N
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158252 , vital:40166 , https://0-doi.org.wam.seals.ac.za/10.1007/s12371-020-00486-z
- Description: Many of the national parks in East Africa are equally as famous for their iconic landforms as they are for their diversity and concentrations of fauna and flora. The newly formed Ngorongoro-Lengai Geopark in northern Tanzania is the first geopark to be established in the region, but there is remarkable potential for geotourism in the majority of the national parks. The most spectacular landforms have been shaped by the East African Rift System. Formation of the two major rifts in the region, the Albertine Rift (or western branch) and the Gregory Rift (or eastern branch), was accompanied, or in some cases preceded, by extensive alkaline volcanism. The rifting and volcanism are primarily Late Cenozoic phenomenon that dissected and overprinted the older regional plateaus. Rifting impacted the regional drainage and captured major rivers, including the Victoria Nile.
- Full Text:
- Date Issued: 2020
- Authors: Scoon, Roger N
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158252 , vital:40166 , https://0-doi.org.wam.seals.ac.za/10.1007/s12371-020-00486-z
- Description: Many of the national parks in East Africa are equally as famous for their iconic landforms as they are for their diversity and concentrations of fauna and flora. The newly formed Ngorongoro-Lengai Geopark in northern Tanzania is the first geopark to be established in the region, but there is remarkable potential for geotourism in the majority of the national parks. The most spectacular landforms have been shaped by the East African Rift System. Formation of the two major rifts in the region, the Albertine Rift (or western branch) and the Gregory Rift (or eastern branch), was accompanied, or in some cases preceded, by extensive alkaline volcanism. The rifting and volcanism are primarily Late Cenozoic phenomenon that dissected and overprinted the older regional plateaus. Rifting impacted the regional drainage and captured major rivers, including the Victoria Nile.
- Full Text:
- Date Issued: 2020
The spatiotemporal aspects of predation on the Cape gannet Morus capensis population at the Lambert’s Bay gannet colony, Western Cape, South Africa
- Authors: Schoeman, Zanri
- Date: 2020
- Subjects: Sea birds -- South Africa -- Western Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/47656 , vital:40262
- Description: Seabirds are one of the most threatened groups of birds with 29% of seabird species at some risk of extinction. As a result of multiple human-induced threats, seabird species including the Cape gannet Morus capensis which is endemic to southern Africa population experience significant declines and is now classified as Endangered. The Cape gannet faces predation threats from a variety of different species. The current predators of concern at Lambert’s Bay gannet colony are both the Cape fur seal Arctocephalus pusillus pusillus and the Kelp gull Larus dominancus. The former predates on fledglings and the latter predates on eggs. In the 2005/06 breeding season the entire Cape gannet population deserted the Lambert’s Bay gannet colony due to predation by the Cape fur seal. Although the Cape gannets have subsequently recovered to approximately 8000 pairs, seal predation on Cape gannet fledglings continues, together with predation by Kelp gulls. This has caused concern over the impact of predation on this species at the Lambert’s Bay colony, particularly given the species’ conservation status, its small breeding range and its current population trend. CapeNature, the conservation agency involved at this colony has been monitoring and managing the predation on Cape gannets and are interested in evaluating the success of their efforts. Therefore the aim of this study was to determine the spatial and temporal aspects of predation on the Cape gannet population at Lambert’s Bay gannet colony. When examining the influence of fish availability on predation intensity, we found that in years with an increase in fish biomass there was a decrease in predation probability by Cape fur seals. This increase in fish biomass not only led to decreased predation on the fledglings it also led to increased breeding success of the Cape gannets. In determining the effect of predation within the Cape gannet breeding colony we found that the probability of predation by Kelp gulls decreased in years with increased adult gannet density. Indirectly, Cape gannet population growth should lead to a decrease in Kelp gull predation as a higher gannet density increases the risk of injury to the Kelp gulls. This suggests that if Cape gannet populations continue to decline, they may become increasingly vulnerable to Kelp gull predation which can result in a further population decline. In terms of past management actions, the selective culling of predatory Cape fur seals and Kelp gulls, was evaluated. It was found that in the years in which culling of Cape fur seals and Kelp gulls was implemented, a decrease in predation was observed. This indicated that culling reduced predation in the short-term. Predation is inevitable, but due to the Cape gannet’s conservation status we suggest that additional, long-term, and more sustainable methods to reduce predation should be explored. Our research emphasises the need for improving food availability to Cape gannets as food security is paramount to their long-term survival and population growth. Colony management in isolation from other management strategies, is not efficient for conserving a species. We therefore suggest that sound management of predation at the terrestrial habitats are required but that effective management of fisheries are also required for the successful conservation of the Cape gannet. Food security for Cape gannets could be improved by, for example, establishing some ways that we suggest improving the food security for Cape gannets would be to establish Marine Protected Areas (MPAs) with dynamic boundaries around Cape gannet colonies, and to have locate the MPAs close to breeding and foraging hotspots where these areas are closed to fishing thus reducing the competition between commercial fisheries and marine predators, such as the Cape gannet. Another way to improve food security for the gannets are to promote the efforts of focussing on developing and implementing an ecosystem approach to fisheries management in which fishing quotas account for the needs of marine predators. The findings of this study have not only aided the understanding of the dynamics of predation on the Cape gannets and highlighted the extent that predation takes place on them but can also guide future management decisions regarding predation on this endemic and endangered species.
- Full Text:
- Date Issued: 2020
- Authors: Schoeman, Zanri
- Date: 2020
- Subjects: Sea birds -- South Africa -- Western Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/47656 , vital:40262
- Description: Seabirds are one of the most threatened groups of birds with 29% of seabird species at some risk of extinction. As a result of multiple human-induced threats, seabird species including the Cape gannet Morus capensis which is endemic to southern Africa population experience significant declines and is now classified as Endangered. The Cape gannet faces predation threats from a variety of different species. The current predators of concern at Lambert’s Bay gannet colony are both the Cape fur seal Arctocephalus pusillus pusillus and the Kelp gull Larus dominancus. The former predates on fledglings and the latter predates on eggs. In the 2005/06 breeding season the entire Cape gannet population deserted the Lambert’s Bay gannet colony due to predation by the Cape fur seal. Although the Cape gannets have subsequently recovered to approximately 8000 pairs, seal predation on Cape gannet fledglings continues, together with predation by Kelp gulls. This has caused concern over the impact of predation on this species at the Lambert’s Bay colony, particularly given the species’ conservation status, its small breeding range and its current population trend. CapeNature, the conservation agency involved at this colony has been monitoring and managing the predation on Cape gannets and are interested in evaluating the success of their efforts. Therefore the aim of this study was to determine the spatial and temporal aspects of predation on the Cape gannet population at Lambert’s Bay gannet colony. When examining the influence of fish availability on predation intensity, we found that in years with an increase in fish biomass there was a decrease in predation probability by Cape fur seals. This increase in fish biomass not only led to decreased predation on the fledglings it also led to increased breeding success of the Cape gannets. In determining the effect of predation within the Cape gannet breeding colony we found that the probability of predation by Kelp gulls decreased in years with increased adult gannet density. Indirectly, Cape gannet population growth should lead to a decrease in Kelp gull predation as a higher gannet density increases the risk of injury to the Kelp gulls. This suggests that if Cape gannet populations continue to decline, they may become increasingly vulnerable to Kelp gull predation which can result in a further population decline. In terms of past management actions, the selective culling of predatory Cape fur seals and Kelp gulls, was evaluated. It was found that in the years in which culling of Cape fur seals and Kelp gulls was implemented, a decrease in predation was observed. This indicated that culling reduced predation in the short-term. Predation is inevitable, but due to the Cape gannet’s conservation status we suggest that additional, long-term, and more sustainable methods to reduce predation should be explored. Our research emphasises the need for improving food availability to Cape gannets as food security is paramount to their long-term survival and population growth. Colony management in isolation from other management strategies, is not efficient for conserving a species. We therefore suggest that sound management of predation at the terrestrial habitats are required but that effective management of fisheries are also required for the successful conservation of the Cape gannet. Food security for Cape gannets could be improved by, for example, establishing some ways that we suggest improving the food security for Cape gannets would be to establish Marine Protected Areas (MPAs) with dynamic boundaries around Cape gannet colonies, and to have locate the MPAs close to breeding and foraging hotspots where these areas are closed to fishing thus reducing the competition between commercial fisheries and marine predators, such as the Cape gannet. Another way to improve food security for the gannets are to promote the efforts of focussing on developing and implementing an ecosystem approach to fisheries management in which fishing quotas account for the needs of marine predators. The findings of this study have not only aided the understanding of the dynamics of predation on the Cape gannets and highlighted the extent that predation takes place on them but can also guide future management decisions regarding predation on this endemic and endangered species.
- Full Text:
- Date Issued: 2020
Synthesis and application of fluorescent triazolyl-coumarin based chemosensors
- Authors: Schoeman, Stiaan
- Date: 2020
- Subjects: Chemistry
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/47454 , vital:39992
- Description: The search for a fluorescent chemosensor with high selectivity and sensitivity that can be used for the detection of trace amounts of a toxic transition metal or heavy metal ions have gained immense popularity in recent years. Coumarin derivatives have been widely used as the basis of these fluorescent chemosensors by which a 1,2,3-triazole ring is used as the binding site for such metal ions. The benefits of chemosensors include nearly eliminating the need for tedious sample preparation and highly skilled operators. Therefore, enabling quantitative and qualitative measurement in both a lab setting and on-site. In addition, chemosensors provide a more sensitive and selective detection method at low-cost. A variety of chemosensors were designed and synthesized, in which some synthesis steps were refined to obtain better yields and purer products. Chemosensors designed, in this study, can be divided into novel triazolyl-coumarin derivatives without a spacer 1C – 1D and with a spacer between the coumarin and triazole ring (2D and 2E). 1C – 1D were characterized by 1H NMR, 13C NMR and IR and photophysical properties were investigated in DMF. 2D and 2E could not be purified and further investigation was discontinued. An overall enhancement was observed for the chemosensors 1C – 1D in the presence of 24 different ions that were tested. 1C had a quenching effect in the presence of Cd2+, however, competition studies revealed that 1C is not selective in the presence of competing metal cations. Molecular modelling studies were performed on sensors 1C – 1G in the presence of various ions. The molecular modelling studies provided invaluable insights into the binding of the selected metal ions as well as revealed a variety of binding sites. In addition, the space-filled depictions offered insights into the overlapping during binding which had an effect in the electrostatic potential maps of the chemosensors..
- Full Text:
- Date Issued: 2020
- Authors: Schoeman, Stiaan
- Date: 2020
- Subjects: Chemistry
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/47454 , vital:39992
- Description: The search for a fluorescent chemosensor with high selectivity and sensitivity that can be used for the detection of trace amounts of a toxic transition metal or heavy metal ions have gained immense popularity in recent years. Coumarin derivatives have been widely used as the basis of these fluorescent chemosensors by which a 1,2,3-triazole ring is used as the binding site for such metal ions. The benefits of chemosensors include nearly eliminating the need for tedious sample preparation and highly skilled operators. Therefore, enabling quantitative and qualitative measurement in both a lab setting and on-site. In addition, chemosensors provide a more sensitive and selective detection method at low-cost. A variety of chemosensors were designed and synthesized, in which some synthesis steps were refined to obtain better yields and purer products. Chemosensors designed, in this study, can be divided into novel triazolyl-coumarin derivatives without a spacer 1C – 1D and with a spacer between the coumarin and triazole ring (2D and 2E). 1C – 1D were characterized by 1H NMR, 13C NMR and IR and photophysical properties were investigated in DMF. 2D and 2E could not be purified and further investigation was discontinued. An overall enhancement was observed for the chemosensors 1C – 1D in the presence of 24 different ions that were tested. 1C had a quenching effect in the presence of Cd2+, however, competition studies revealed that 1C is not selective in the presence of competing metal cations. Molecular modelling studies were performed on sensors 1C – 1G in the presence of various ions. The molecular modelling studies provided invaluable insights into the binding of the selected metal ions as well as revealed a variety of binding sites. In addition, the space-filled depictions offered insights into the overlapping during binding which had an effect in the electrostatic potential maps of the chemosensors..
- Full Text:
- Date Issued: 2020
A comparison between the responsiveness of selected physiological and subjective mental workload indicators during real-world driving scenarios
- Authors: Schmidtke, Nadia-Jasmine
- Date: 2020
- Subjects: Automobile driving -- Physiological aspects , Automobile driving -- Psychological aspects , Automobile drivers -- Health and hygiene , Mental fatigue , Mental work -- Case studies
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/148115 , vital:38711
- Description: Sub-optimal levels of mental workload in automobile drivers is a risk factor for road accidents. However, mental workload as a construct cannot be directly measured. Common indicators of mental workload include heart rate frequency and variability, eye motion and subjective rating tools. Namely, the National Aeronautics and Space Administration Task Load Index (NASA-TLX), its modified, unweighted version called the Raw-TLX, and the Rating Scale of Mental Effort (RSME). Comparisons between the suitability and responsiveness of these mental workload indicators have been almost exclusively examined in driving simulators. However, real-world driving research is important as even high-fidelity simulators cannot capture the complexity of driving scenarios. Hence, this research aimed to compare the suitability and responsiveness of these mental workload indicators in response to real-world driving scenarios. Six participants drove along a set route for an hour while wearing a heart rate monitor and eye tracker. A dashcam was used to capture footage of the different driving scenarios encountered. The set route comprised of driving through the industrial, residential, provincial main road and Rhodes University campus areas. RSME scores were taken during brief stops after driving though each zone. The NASA-TLX questionnaire was administered on completion of the drive and analysed later as the modified Raw-TLX version. The data collected in response to the encountered driving scenarios were sorted into three meta-groupings. (1) Data was segmented according to the different areas that participants drove through. This was termed Area Events and were long duration scenarios of between five and thirty minutes. These driving scenarios were further segmented into two meta-groups with short duration driving scenarios (< 90 seconds). (2) The Common Events meta-group consisted of driving scenarios that were encountered by all participants. These were scenarios were anticipated by drivers. (3) The All Events meta-group was grouped according to all the driving scenarios that were encountered by participants. It consisted of both anticipated and unanticipated driving scenarios of short durations. Data were further analysed using a method of systematically selecting a threshold value for each mental workload indicator. Responses to driving scenarios which surpassed the threshold were considered indicative of an increase in mental workload. The total frequency of higher mental workload events was used as a determiner responsiveness (or ‘sensitivity’) for each mental workload indicator. Mental workload indicators were evaluated for their responsiveness and suitability for assessing mental workload. Results found blink frequency to be a responsive mental workload indicator for all categories of driving scenarios. Blink frequency and duration were the most responsive short duration mental workload indicators. Furthermore, the indicators were able to distinguish between higher and lower mental workload driving scenarios. However, blink parameters are also sensitive to driver fatigue and drowsiness. Further research on distinguishing mental workload from that of fatigue in response to real-world driving was recommended. Pupil diameter, fixation duration, saccade saccade duration and saccade amplitude were found to be responsive short duration mental workload indicators. However, these measures were not determined to be suitable for real-world driving applications. Pupil diameter was confounded by changing illumination levels. Fixation and saccade responses were confounded by the driving task itself as gaze could not be accounted for. For long duration driving scenarios heart rate frequency, heart rate variability: high-frequency power, blink frequency and RSME were found to be responsive and suitable MWL indicators. The Raw-TLX results could not be assessed for responsiveness as it was administered once. However, it was confirmed as a suitable cumulative mental workload indicator in the application of real-world driving. The moderate levels of workload reported by participants agreed with the experimental protocol that prevented inducing sub-optimal mental workload. Blink frequency shows promise as a responsive and suitable mental workload indicator for different types of driving scenarios. More research is needed regarding the assessment of mental workload during short durations using blink frequency and blink duration. For driving durations between five and thirty minutes long, further research into heart rate frequency, heart rate variability: high frequency power, and the RSME was recommended.
- Full Text:
- Date Issued: 2020
- Authors: Schmidtke, Nadia-Jasmine
- Date: 2020
- Subjects: Automobile driving -- Physiological aspects , Automobile driving -- Psychological aspects , Automobile drivers -- Health and hygiene , Mental fatigue , Mental work -- Case studies
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/148115 , vital:38711
- Description: Sub-optimal levels of mental workload in automobile drivers is a risk factor for road accidents. However, mental workload as a construct cannot be directly measured. Common indicators of mental workload include heart rate frequency and variability, eye motion and subjective rating tools. Namely, the National Aeronautics and Space Administration Task Load Index (NASA-TLX), its modified, unweighted version called the Raw-TLX, and the Rating Scale of Mental Effort (RSME). Comparisons between the suitability and responsiveness of these mental workload indicators have been almost exclusively examined in driving simulators. However, real-world driving research is important as even high-fidelity simulators cannot capture the complexity of driving scenarios. Hence, this research aimed to compare the suitability and responsiveness of these mental workload indicators in response to real-world driving scenarios. Six participants drove along a set route for an hour while wearing a heart rate monitor and eye tracker. A dashcam was used to capture footage of the different driving scenarios encountered. The set route comprised of driving through the industrial, residential, provincial main road and Rhodes University campus areas. RSME scores were taken during brief stops after driving though each zone. The NASA-TLX questionnaire was administered on completion of the drive and analysed later as the modified Raw-TLX version. The data collected in response to the encountered driving scenarios were sorted into three meta-groupings. (1) Data was segmented according to the different areas that participants drove through. This was termed Area Events and were long duration scenarios of between five and thirty minutes. These driving scenarios were further segmented into two meta-groups with short duration driving scenarios (< 90 seconds). (2) The Common Events meta-group consisted of driving scenarios that were encountered by all participants. These were scenarios were anticipated by drivers. (3) The All Events meta-group was grouped according to all the driving scenarios that were encountered by participants. It consisted of both anticipated and unanticipated driving scenarios of short durations. Data were further analysed using a method of systematically selecting a threshold value for each mental workload indicator. Responses to driving scenarios which surpassed the threshold were considered indicative of an increase in mental workload. The total frequency of higher mental workload events was used as a determiner responsiveness (or ‘sensitivity’) for each mental workload indicator. Mental workload indicators were evaluated for their responsiveness and suitability for assessing mental workload. Results found blink frequency to be a responsive mental workload indicator for all categories of driving scenarios. Blink frequency and duration were the most responsive short duration mental workload indicators. Furthermore, the indicators were able to distinguish between higher and lower mental workload driving scenarios. However, blink parameters are also sensitive to driver fatigue and drowsiness. Further research on distinguishing mental workload from that of fatigue in response to real-world driving was recommended. Pupil diameter, fixation duration, saccade saccade duration and saccade amplitude were found to be responsive short duration mental workload indicators. However, these measures were not determined to be suitable for real-world driving applications. Pupil diameter was confounded by changing illumination levels. Fixation and saccade responses were confounded by the driving task itself as gaze could not be accounted for. For long duration driving scenarios heart rate frequency, heart rate variability: high-frequency power, blink frequency and RSME were found to be responsive and suitable MWL indicators. The Raw-TLX results could not be assessed for responsiveness as it was administered once. However, it was confirmed as a suitable cumulative mental workload indicator in the application of real-world driving. The moderate levels of workload reported by participants agreed with the experimental protocol that prevented inducing sub-optimal mental workload. Blink frequency shows promise as a responsive and suitable mental workload indicator for different types of driving scenarios. More research is needed regarding the assessment of mental workload during short durations using blink frequency and blink duration. For driving durations between five and thirty minutes long, further research into heart rate frequency, heart rate variability: high frequency power, and the RSME was recommended.
- Full Text:
- Date Issued: 2020
The impact of illustrated side effect information on understanding and sustained retention of antiretroviral side effect knowledge:
- Scheihing, Konstantin W, Tanner, Jane, Weaver, Matthew, Schöniger, Matthias
- Authors: Scheihing, Konstantin W , Tanner, Jane , Weaver, Matthew , Schöniger, Matthias
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/156389 , vital:39985 , https://doi.org/10.1016/j.jup.2020.101043
- Description: About 7.5 million South Africans access gratuitous drinking water via communal taps provided by municipalities under a free basic water policy. Supplying running water for free to low-income communities is essential but can result in water wastage due to a potential indifference of non-paying end-consumers. The consequence is a loss of municipal water and financial resources. We outline a new strategy that rewards low-income communities for reducing water wastage. The incentive strategy promotes water conservation and community development and decreases recurring water-related public expenses. The concept is funded by a percentage of municipal cost savings yielded from the respective water conservation.
- Full Text:
- Date Issued: 2020
- Authors: Scheihing, Konstantin W , Tanner, Jane , Weaver, Matthew , Schöniger, Matthias
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/156389 , vital:39985 , https://doi.org/10.1016/j.jup.2020.101043
- Description: About 7.5 million South Africans access gratuitous drinking water via communal taps provided by municipalities under a free basic water policy. Supplying running water for free to low-income communities is essential but can result in water wastage due to a potential indifference of non-paying end-consumers. The consequence is a loss of municipal water and financial resources. We outline a new strategy that rewards low-income communities for reducing water wastage. The incentive strategy promotes water conservation and community development and decreases recurring water-related public expenses. The concept is funded by a percentage of municipal cost savings yielded from the respective water conservation.
- Full Text:
- Date Issued: 2020
Nutrient patchiness, phytoplankton surge-uptake, and turbulent history: a theoretical approach and its experimental validation
- Schapira, Mathilde, Seuront, Laurent
- Authors: Schapira, Mathilde , Seuront, Laurent
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149774 , vital:38883 , https://doi.org/10.3390/fluids5020080
- Description: Despite ample evidence of micro- and small-scale (i.e., millimeter- to meter-scale) phytoplankton and zooplankton patchiness in the ocean, direct observations of nutrient distributions and the ecological importance of this phenomenon are still relatively scarce. In this context, we first describe a simple procedure to continuously sample nutrients in surface waters, and subsequently provide evidence of the existence of microscale distribution of ammonium in the ocean. We further show that ammonium is never homogeneously distributed, even under very high conditions of turbulence. Instead, turbulence intensity appears to control nutrient patchiness, with a more homogeneous or a more heterogeneous distribution observed under high and low turbulence intensities, respectively, under the same concentration in nutrient. Based on a modelling procedure taking into account the stochastic properties of intermittent nutrient distributions and observations carried out on natural phytoplankton communities, we introduce and verify the hypothesis that under nutrient limitation, the “turbulent history” of phytoplankton cells, i.e., the turbulent conditions they experienced in their natural environments, conditions their efficiency to uptake ephemeral inorganic nitrogen patches of different concentrations.
- Full Text:
- Date Issued: 2020
- Authors: Schapira, Mathilde , Seuront, Laurent
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149774 , vital:38883 , https://doi.org/10.3390/fluids5020080
- Description: Despite ample evidence of micro- and small-scale (i.e., millimeter- to meter-scale) phytoplankton and zooplankton patchiness in the ocean, direct observations of nutrient distributions and the ecological importance of this phenomenon are still relatively scarce. In this context, we first describe a simple procedure to continuously sample nutrients in surface waters, and subsequently provide evidence of the existence of microscale distribution of ammonium in the ocean. We further show that ammonium is never homogeneously distributed, even under very high conditions of turbulence. Instead, turbulence intensity appears to control nutrient patchiness, with a more homogeneous or a more heterogeneous distribution observed under high and low turbulence intensities, respectively, under the same concentration in nutrient. Based on a modelling procedure taking into account the stochastic properties of intermittent nutrient distributions and observations carried out on natural phytoplankton communities, we introduce and verify the hypothesis that under nutrient limitation, the “turbulent history” of phytoplankton cells, i.e., the turbulent conditions they experienced in their natural environments, conditions their efficiency to uptake ephemeral inorganic nitrogen patches of different concentrations.
- Full Text:
- Date Issued: 2020
Post-release monitoring in classical biological control of weeds: higher trophic levels modify competitive interactions between invasive macrophytes
- Schaffner, Urs, Hill, Martin P, Dudley, Tom, D’Antonio, Carla
- Authors: Schaffner, Urs , Hill, Martin P , Dudley, Tom , D’Antonio, Carla
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150200 , vital:38949 , https://doi.org/10.1016/j.cois.2020.02.008
- Description: While various aspects of classical biological control (CBC) of weeds, including non-target risk assessment, have been continuously improved in the past few decades, post-release monitoring remains neglected and underfunded. Detailed assessments of the population, community and ecosystem outcomes of CBC introductions, including reasons for success/failure and absence or evidence of non-target effects are generally lacking or fragmentary. Here we review recent advances in understanding the demography of biological control agents released into a novel environment, their impact on the target weed and on non-target species, and the consequences for the resident plant and animal communities and ecosystem functioning, including the restoration of ecosystem services. We argue that post-release monitoring of CBC programs offers unique but largely underutilized opportunities to improve our understanding of CBC outcomes and to inform management and decision-makers on when and how CBC should be integrated with other management options to enhance ecosystem restoration.
- Full Text:
- Date Issued: 2020
- Authors: Schaffner, Urs , Hill, Martin P , Dudley, Tom , D’Antonio, Carla
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150200 , vital:38949 , https://doi.org/10.1016/j.cois.2020.02.008
- Description: While various aspects of classical biological control (CBC) of weeds, including non-target risk assessment, have been continuously improved in the past few decades, post-release monitoring remains neglected and underfunded. Detailed assessments of the population, community and ecosystem outcomes of CBC introductions, including reasons for success/failure and absence or evidence of non-target effects are generally lacking or fragmentary. Here we review recent advances in understanding the demography of biological control agents released into a novel environment, their impact on the target weed and on non-target species, and the consequences for the resident plant and animal communities and ecosystem functioning, including the restoration of ecosystem services. We argue that post-release monitoring of CBC programs offers unique but largely underutilized opportunities to improve our understanding of CBC outcomes and to inform management and decision-makers on when and how CBC should be integrated with other management options to enhance ecosystem restoration.
- Full Text:
- Date Issued: 2020
The roles of phonological awareness, rapid automatised naming and morphological awareness in isiXhosa:
- Schaefer, Maxine, Probert, Tracy N, Rees, Siȃn
- Authors: Schaefer, Maxine , Probert, Tracy N , Rees, Siȃn
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159950 , vital:40359 , https://doi.org/10.5785/36-1-878
- Description: The current paper examines the unique contributions of phonological awareness (PA), rapid automatised naming (RAN) and morphological awareness (MA) to oral reading fluency (ORF) in isiXhosa. No published study has yet explored the individual contributions of these three cognitive-linguistic skills to reading in isiXhosa. Sixty-six grade 3 home language isiXhosa learners were assessed on these cognitive-linguistic skills. Results from a linear regression analysis showed that only RAN and MA, but not PA, were significant concurrent predictors of ORF. These results suggest that the role of PA in reading in grade 3 learners in isiXhosa may have been overestimated because other important predictors of reading have not been controlled. Our data also suggest that grade 3 isiXhosa learners may make use of the morpheme as a grain size in reading. Our study highlights the need for longitudinal research which explores the roles of PA, MA and RAN in reading development in order to inform reading pedagogy in isiXhosa and other Southern Bantu languages.
- Full Text:
- Date Issued: 2020
- Authors: Schaefer, Maxine , Probert, Tracy N , Rees, Siȃn
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159950 , vital:40359 , https://doi.org/10.5785/36-1-878
- Description: The current paper examines the unique contributions of phonological awareness (PA), rapid automatised naming (RAN) and morphological awareness (MA) to oral reading fluency (ORF) in isiXhosa. No published study has yet explored the individual contributions of these three cognitive-linguistic skills to reading in isiXhosa. Sixty-six grade 3 home language isiXhosa learners were assessed on these cognitive-linguistic skills. Results from a linear regression analysis showed that only RAN and MA, but not PA, were significant concurrent predictors of ORF. These results suggest that the role of PA in reading in grade 3 learners in isiXhosa may have been overestimated because other important predictors of reading have not been controlled. Our data also suggest that grade 3 isiXhosa learners may make use of the morpheme as a grain size in reading. Our study highlights the need for longitudinal research which explores the roles of PA, MA and RAN in reading development in order to inform reading pedagogy in isiXhosa and other Southern Bantu languages.
- Full Text:
- Date Issued: 2020
Activity of diverse chalcones against several targets: statistical analysis of a high-throughput virtual screen of a custom chalcone library
- Authors: Sarron, Arthur F D
- Date: 2020
- Subjects: Acetophenone , Benzaldehyde , Ketones , Pyruvate kinase , Drug development , Aromatic compounds , Heat shock proteins
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/116028 , vital:34291
- Description: Chalcone family molecules are well known to have therapeutic proprieties (anti-inflammatory, anti-microbial or anti-cancer, etc). However the mechanism of action in some cases is not well known. A virtual library of this family of compounds was constructed using custom scripts, based on the aldol condensation, and this library was modified further to analogues by expansion of the α,β-unsaturated ketone linker. Acetophenone and benzaldehyde derivatives which are available and purchasable were used as a base to design the chalcone virtual library. 8063 chalcones were constructed and geometrically optimized with Gaussian 09. Their physicochemical characteristics linked to the Lipinski rules were analyzed with Knime and CDK. The entire library was after docked against several targets including HIV-1 integrase, MRSA pyruvate kinase, HSP90, COX-1, COX-2, ALR2, MAOA, MAOB, acetylcholinesterase, butyrylcholinesterase and PLA2. With the exception of MAOA, which does not have a crystal structure ligand, all dockings were validated by redocking the original ligand provided by the literature. These targets are known in the literature to be inhibited by chalcone-derivatives. However, specificity of the particular known chalcone inhibitors to the particular targets is not known. To this end the performance of the generated chalcone library against the list of targets was of interest. The binding energy of ligand-protein complexes was generally good across the library. Statistical analysis including principal component analysis and hierarchical clustering analysis were made in order to investigate for any physical/chemical characteristics which might explain what chalcone features affect the binding energy of the ligand-protein complexes. The spherical polar coordinates defining the orientation of the binding poses were also calculated and used in the statistical analysis. The statistical analysis has allowed us to hypothesize the importance of these radial distances and the polar angles of key atoms in the chalcones in binding to the pyruvate kinase crystal structure. This was validated by the docking of another small library of compound models in which the α,β-unsaturated ketone chain of the chalcone was replaced by incrementally longer conjugated chains. Further studies on the chalcones themselves reveal rotameric systems in both cis and trans-configurations (which may impact binding), and also studied was the effect of Topliss-based modification and its impact of binding to HSP90. Molecular dynamics confirmed good binding of identified chalcone hits.
- Full Text:
- Date Issued: 2020
- Authors: Sarron, Arthur F D
- Date: 2020
- Subjects: Acetophenone , Benzaldehyde , Ketones , Pyruvate kinase , Drug development , Aromatic compounds , Heat shock proteins
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/116028 , vital:34291
- Description: Chalcone family molecules are well known to have therapeutic proprieties (anti-inflammatory, anti-microbial or anti-cancer, etc). However the mechanism of action in some cases is not well known. A virtual library of this family of compounds was constructed using custom scripts, based on the aldol condensation, and this library was modified further to analogues by expansion of the α,β-unsaturated ketone linker. Acetophenone and benzaldehyde derivatives which are available and purchasable were used as a base to design the chalcone virtual library. 8063 chalcones were constructed and geometrically optimized with Gaussian 09. Their physicochemical characteristics linked to the Lipinski rules were analyzed with Knime and CDK. The entire library was after docked against several targets including HIV-1 integrase, MRSA pyruvate kinase, HSP90, COX-1, COX-2, ALR2, MAOA, MAOB, acetylcholinesterase, butyrylcholinesterase and PLA2. With the exception of MAOA, which does not have a crystal structure ligand, all dockings were validated by redocking the original ligand provided by the literature. These targets are known in the literature to be inhibited by chalcone-derivatives. However, specificity of the particular known chalcone inhibitors to the particular targets is not known. To this end the performance of the generated chalcone library against the list of targets was of interest. The binding energy of ligand-protein complexes was generally good across the library. Statistical analysis including principal component analysis and hierarchical clustering analysis were made in order to investigate for any physical/chemical characteristics which might explain what chalcone features affect the binding energy of the ligand-protein complexes. The spherical polar coordinates defining the orientation of the binding poses were also calculated and used in the statistical analysis. The statistical analysis has allowed us to hypothesize the importance of these radial distances and the polar angles of key atoms in the chalcones in binding to the pyruvate kinase crystal structure. This was validated by the docking of another small library of compound models in which the α,β-unsaturated ketone chain of the chalcone was replaced by incrementally longer conjugated chains. Further studies on the chalcones themselves reveal rotameric systems in both cis and trans-configurations (which may impact binding), and also studied was the effect of Topliss-based modification and its impact of binding to HSP90. Molecular dynamics confirmed good binding of identified chalcone hits.
- Full Text:
- Date Issued: 2020
Urban foraging: land management policy, perspectives, and potential
- Sardeshpande, Mallika, Shackleton, Charlie M
- Authors: Sardeshpande, Mallika , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149384 , vital:38845 , https://0-doi.org.wam.seals.ac.za/10.1371/journal.pone.0230693
- Description: Gathering of uncultivated food from green spaces, also known as foraging, is observed in urban areas across the world, but the literature focuses predominantly on the global north. Our study examines the existing urban land management structure and its approach to urban foraging in the eastern coastal region of South Africa. Through interviews with municipal officials in nine cities, we identified different stakeholders and their roles in urban green space management. We then used network analysis to represent interactions and influence of these stakeholders, and environmental worldviews to determine organisational and perceptual barriers to and enablers of foraging in urban green spaces. The policy on urban green space management, as well as land managers themselves are amenable to the concept of foraging in public spaces. Lack of knowledge on wild indigenous species and sustainable offtake, ambiguous, coarse, or lacking policy, and normative views of pristine nature may hinder foraging. We recommend pathways for policy and stakeholder partnerships to incorporate sustainable foraging in their biodiversity conservation and land stewardship strategies.
- Full Text:
- Date Issued: 2020
- Authors: Sardeshpande, Mallika , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149384 , vital:38845 , https://0-doi.org.wam.seals.ac.za/10.1371/journal.pone.0230693
- Description: Gathering of uncultivated food from green spaces, also known as foraging, is observed in urban areas across the world, but the literature focuses predominantly on the global north. Our study examines the existing urban land management structure and its approach to urban foraging in the eastern coastal region of South Africa. Through interviews with municipal officials in nine cities, we identified different stakeholders and their roles in urban green space management. We then used network analysis to represent interactions and influence of these stakeholders, and environmental worldviews to determine organisational and perceptual barriers to and enablers of foraging in urban green spaces. The policy on urban green space management, as well as land managers themselves are amenable to the concept of foraging in public spaces. Lack of knowledge on wild indigenous species and sustainable offtake, ambiguous, coarse, or lacking policy, and normative views of pristine nature may hinder foraging. We recommend pathways for policy and stakeholder partnerships to incorporate sustainable foraging in their biodiversity conservation and land stewardship strategies.
- Full Text:
- Date Issued: 2020
Foraging for fruits: natural resource use and its conservation potential in urban environments
- Authors: Sardeshpande, Mallika
- Date: 2020
- Subjects: Non-timber forest products , Wild plants, Edible , Urban plants , Urban ecology (Biology) , Open spaces , Environmental protection -- Citizen participation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167465 , vital:41483
- Description: Wild edible fruits (WEFs) are a type of natural resource that humans across the world collect from diverse natural landscapes. They are among the most used non-timber forest products (NTFPs) and wild foods, and often serve more than a nutritional purpose for humans, in the form of fibre, fuel, medicine, and other products. The use of WEFs may augment household dietary diversity, food security, and income in some contexts. The prevalence of WEF species across the spectrum of natural to modified ecosystems presents the potential for integrated landscape-level conservation efforts centred on these species. The first half of this thesis investigates the state of knowledge about this versatile and ubiquitous resource in the wider context of other wild foods and NTFPs, and compares the patterns of use of WEFs with those of other wild foods and NTFPs. Through these studies, I find that WEFs are indeed a widely occurring, resilient, and useful resource along the rural-urban gradient. They are unique in that their use transcends the geographical and socio-economic criteria that influence the use of other wild foods and NTFPs. Based on these findings, in the second half of the thesis, I propose the use-based conservation of WEF species in urban landscapes through the practice of urban foraging. Through interviews with urban land managers and foragers, I describe the state of urban green space management and urban foraging, and identify synergies between the two. Green space management is increasingly devolved and well-defined in developed cities, and relatively diffused in smaller towns, but nevertheless supportive of use-based biodiversity conservation. Planting and foraging for WEFs in urban green spaces ties in with local and national objectives of urban land use management policy. However, the lack of information on species, spaces, and sustainability related to foraging are a hindrance to addressing this activity and harnessing its conservation potential. Foragers use a variety of WEF species collected from natural as well as highly used and urbanised areas in their cities. Although most foragers consider foraging as a cultural and recreational activity, many of them agreed with the prospect of commercialising or popularising it to protect and promote the biodiversity and culture associated with their foraging spaces. The synthesis of this study presents four possible pathways to conserve the diversity of WEF species, and to extend the benefits of WEF use to landscape stewardship. It identifies key stakeholders in implementing these pathways and possible collaborations between these stakeholders; the multiple conservation objectives and policies these pathways respond to; and context-specific considerations for policy and implementation related to planting and foraging of WEFs.
- Full Text:
- Date Issued: 2020
- Authors: Sardeshpande, Mallika
- Date: 2020
- Subjects: Non-timber forest products , Wild plants, Edible , Urban plants , Urban ecology (Biology) , Open spaces , Environmental protection -- Citizen participation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/167465 , vital:41483
- Description: Wild edible fruits (WEFs) are a type of natural resource that humans across the world collect from diverse natural landscapes. They are among the most used non-timber forest products (NTFPs) and wild foods, and often serve more than a nutritional purpose for humans, in the form of fibre, fuel, medicine, and other products. The use of WEFs may augment household dietary diversity, food security, and income in some contexts. The prevalence of WEF species across the spectrum of natural to modified ecosystems presents the potential for integrated landscape-level conservation efforts centred on these species. The first half of this thesis investigates the state of knowledge about this versatile and ubiquitous resource in the wider context of other wild foods and NTFPs, and compares the patterns of use of WEFs with those of other wild foods and NTFPs. Through these studies, I find that WEFs are indeed a widely occurring, resilient, and useful resource along the rural-urban gradient. They are unique in that their use transcends the geographical and socio-economic criteria that influence the use of other wild foods and NTFPs. Based on these findings, in the second half of the thesis, I propose the use-based conservation of WEF species in urban landscapes through the practice of urban foraging. Through interviews with urban land managers and foragers, I describe the state of urban green space management and urban foraging, and identify synergies between the two. Green space management is increasingly devolved and well-defined in developed cities, and relatively diffused in smaller towns, but nevertheless supportive of use-based biodiversity conservation. Planting and foraging for WEFs in urban green spaces ties in with local and national objectives of urban land use management policy. However, the lack of information on species, spaces, and sustainability related to foraging are a hindrance to addressing this activity and harnessing its conservation potential. Foragers use a variety of WEF species collected from natural as well as highly used and urbanised areas in their cities. Although most foragers consider foraging as a cultural and recreational activity, many of them agreed with the prospect of commercialising or popularising it to protect and promote the biodiversity and culture associated with their foraging spaces. The synthesis of this study presents four possible pathways to conserve the diversity of WEF species, and to extend the benefits of WEF use to landscape stewardship. It identifies key stakeholders in implementing these pathways and possible collaborations between these stakeholders; the multiple conservation objectives and policies these pathways respond to; and context-specific considerations for policy and implementation related to planting and foraging of WEFs.
- Full Text:
- Date Issued: 2020
Fruits of the Veld: Ecological and Socioeconomic Patterns of Natural Resource Use across South Africa
- Sardeshpande, Mallika, Shackleton, Charlie M
- Authors: Sardeshpande, Mallika , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175756 , vital:42621 , https://doi.org/10.1007/s10745-020-00185-x
- Description: Wild edible fruits (WEFs) are important non-timber forest products (NTFP) that are commonly grouped with other wild foods or NTFPs in general. We hypothesize that WEFs, other wild foods, and non-food NTFPs contribute in different ways to household economies. Using data collected through a survey of 503 households in South Africa, we describe patterns of use of WEFs across socioeconomic and geographical gradients and compare them to the patterns of use of other wild foods and non-food NTFPs. WEFs were used by one-fifth of all sampled households, independent of economic and urbanisation gradients and were grown in or collected mostly from surrounding areas. More households, usually in rural areas, used other wild foods and non-food NTFPs, which were often purchased from other collectors.
- Full Text:
- Date Issued: 2020
- Authors: Sardeshpande, Mallika , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175756 , vital:42621 , https://doi.org/10.1007/s10745-020-00185-x
- Description: Wild edible fruits (WEFs) are important non-timber forest products (NTFP) that are commonly grouped with other wild foods or NTFPs in general. We hypothesize that WEFs, other wild foods, and non-food NTFPs contribute in different ways to household economies. Using data collected through a survey of 503 households in South Africa, we describe patterns of use of WEFs across socioeconomic and geographical gradients and compare them to the patterns of use of other wild foods and non-food NTFPs. WEFs were used by one-fifth of all sampled households, independent of economic and urbanisation gradients and were grown in or collected mostly from surrounding areas. More households, usually in rural areas, used other wild foods and non-food NTFPs, which were often purchased from other collectors.
- Full Text:
- Date Issued: 2020
Structural Characterization of Carbonic Anhydrase VIII and Effects of Missense Single Nucleotide Variations to Protein Structure and Function:
- Sanyanga, Taremekedzwa Allan, Tastan Bishop, Özlem
- Authors: Sanyanga, Taremekedzwa Allan , Tastan Bishop, Özlem
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149670 , vital:38873 , https://doi.org/10.3390/ijms21082764
- Description: Human carbonic anhydrase 8 (CA-VIII) is an acatalytic isoform of the α -CA family. Though the protein cannot hydrate CO2, CA-VIII is essential for calcium (Ca2+) homeostasis within the body, and achieves this by allosterically inhibiting the binding of inositol 1,4,5-triphosphate (IP3) to the IP3 receptor type 1 (ITPR1) protein. However, the mechanism of interaction of CA-VIII to ITPR1 is not well understood. In addition, functional defects to CA-VIII due to non-synonymous single nucleotide polymorphisms (nsSNVs) result in Ca2+ dysregulation and the development of the phenotypes such as cerebellar ataxia, mental retardation and disequilibrium syndrome 3 (CAMRQ3). The pathogenesis of CAMRQ3 is also not well understood. The structure and function of CA-VIII was characterised, and pathogenesis of CAMRQ3 investigated. Structural and functional characterisation of CA-VIII was conducted through SiteMap and CPORT to identify potential binding site residues.
- Full Text:
- Date Issued: 2020
- Authors: Sanyanga, Taremekedzwa Allan , Tastan Bishop, Özlem
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149670 , vital:38873 , https://doi.org/10.3390/ijms21082764
- Description: Human carbonic anhydrase 8 (CA-VIII) is an acatalytic isoform of the α -CA family. Though the protein cannot hydrate CO2, CA-VIII is essential for calcium (Ca2+) homeostasis within the body, and achieves this by allosterically inhibiting the binding of inositol 1,4,5-triphosphate (IP3) to the IP3 receptor type 1 (ITPR1) protein. However, the mechanism of interaction of CA-VIII to ITPR1 is not well understood. In addition, functional defects to CA-VIII due to non-synonymous single nucleotide polymorphisms (nsSNVs) result in Ca2+ dysregulation and the development of the phenotypes such as cerebellar ataxia, mental retardation and disequilibrium syndrome 3 (CAMRQ3). The pathogenesis of CAMRQ3 is also not well understood. The structure and function of CA-VIII was characterised, and pathogenesis of CAMRQ3 investigated. Structural and functional characterisation of CA-VIII was conducted through SiteMap and CPORT to identify potential binding site residues.
- Full Text:
- Date Issued: 2020