Specialty Grand Challenges in Urban Agriculture: Ecological and Social Approaches to Sustainability Transformations
- Zimmerer, Karl S, Bell, Martha G, Chirisa, Innocent, Duvall, Chris S, Egerer, Monika, Hung, Po-Yi, Lerner, Amy M, Shackleton, Charlie M, Ward, James David, Yacamán Ochoa, Carolina
- Authors: Zimmerer, Karl S , Bell, Martha G , Chirisa, Innocent , Duvall, Chris S , Egerer, Monika , Hung, Po-Yi , Lerner, Amy M , Shackleton, Charlie M , Ward, James David , Yacamán Ochoa, Carolina
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175779 , vital:42623 , https://doi.org/10.3389/fsufs.2021.668561
- Description: This synopsis of the Grand Challenges of Urban Agriculture (UA) is framed by the urgent need to understand and strengthen the expanding yet highly diverse roles of UA amid rapid global urbanization, failures of predominant food systems, and crises in systems of physical and mental health. More than half of humanity lives in cities today and by 2030 this is projected to grow to 60.4 percent, ~5 billion people (UN Habitat, 2020). More than 90 percent of urban demographic increase is anticipated to take place in the developing world.
- Full Text:
- Date Issued: 2021
- Authors: Zimmerer, Karl S , Bell, Martha G , Chirisa, Innocent , Duvall, Chris S , Egerer, Monika , Hung, Po-Yi , Lerner, Amy M , Shackleton, Charlie M , Ward, James David , Yacamán Ochoa, Carolina
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175779 , vital:42623 , https://doi.org/10.3389/fsufs.2021.668561
- Description: This synopsis of the Grand Challenges of Urban Agriculture (UA) is framed by the urgent need to understand and strengthen the expanding yet highly diverse roles of UA amid rapid global urbanization, failures of predominant food systems, and crises in systems of physical and mental health. More than half of humanity lives in cities today and by 2030 this is projected to grow to 60.4 percent, ~5 billion people (UN Habitat, 2020). More than 90 percent of urban demographic increase is anticipated to take place in the developing world.
- Full Text:
- Date Issued: 2021
Ontogenetic and seasonal shifts in the diet of Diplodus cervinus hottentotus (Pisces: Sparidae) in southern Angola
- Winkler, Alexander C, Santos, Carmen V D, Potts, Warren M
- Authors: Winkler, Alexander C , Santos, Carmen V D , Potts, Warren M
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125452 , vital:35784 , https://doi.10.2989/1814232X.2014.951392
- Description: Fishes of the family Sparidae occupy a diverse range of trophic niches, from herbivores to generalist omnivores and specialist predators (Hanel and Tsigenopoulos 2011). Feeding specialisation in this family is facilitated by diversity in tooth type and anterior jaw arrangement (Vandewalle et al. 1995). Other fish families, such as Cyprinidae and Labridae, have developed crushing pharyngeal teeth to process their food. Sparids, however, have retained a simple pharyngeal tooth arrangement and instead have developed molariform teeth to process hard-shelled molluscs and invertebrate prey. Hanel and Tsigenopoulos (2011) suggested that this alternate strategy is a major factor facilitating the trophic diversity in sparid fishes.
- Full Text:
- Date Issued: 2014
- Authors: Winkler, Alexander C , Santos, Carmen V D , Potts, Warren M
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125452 , vital:35784 , https://doi.10.2989/1814232X.2014.951392
- Description: Fishes of the family Sparidae occupy a diverse range of trophic niches, from herbivores to generalist omnivores and specialist predators (Hanel and Tsigenopoulos 2011). Feeding specialisation in this family is facilitated by diversity in tooth type and anterior jaw arrangement (Vandewalle et al. 1995). Other fish families, such as Cyprinidae and Labridae, have developed crushing pharyngeal teeth to process their food. Sparids, however, have retained a simple pharyngeal tooth arrangement and instead have developed molariform teeth to process hard-shelled molluscs and invertebrate prey. Hanel and Tsigenopoulos (2011) suggested that this alternate strategy is a major factor facilitating the trophic diversity in sparid fishes.
- Full Text:
- Date Issued: 2014
Designing writing groups to support postgraduate students’ academic writing: a case study from a South African university
- Authors: Wilmot, Kirstin
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66267 , vital:28926 , https://doi.org/10.1080/14703297.2016.1238775
- Description: publisher version , This paper reports on a writing group pilot programme implemented at a South African university. Drawing on literature, anonymous student evaluations and facilitator observations, it discusses the use of writing groups for supporting postgraduate academic writing practices. Developed within a broader postgraduate academic writing support programme, the paper discusses a case study of two pilot writing groups: a multidisciplinary long-term group and a disciplinary short-term ‘writing-intensive’ group. The findings indicate that the overall experience of the writing group was a positive one, with each group presenting varied ‘success’ aspects as well as challenges. Insights gleaned may contribute to our understanding of how these groups can be utilised to support postgraduate students and how different kinds of groups can be developed to serve particular student needs. The paper concludes with a discussion of the inclusion of a disciplinary expert, which proved particularly useful in this pilot.
- Full Text: false
- Date Issued: 2018
- Authors: Wilmot, Kirstin
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66267 , vital:28926 , https://doi.org/10.1080/14703297.2016.1238775
- Description: publisher version , This paper reports on a writing group pilot programme implemented at a South African university. Drawing on literature, anonymous student evaluations and facilitator observations, it discusses the use of writing groups for supporting postgraduate academic writing practices. Developed within a broader postgraduate academic writing support programme, the paper discusses a case study of two pilot writing groups: a multidisciplinary long-term group and a disciplinary short-term ‘writing-intensive’ group. The findings indicate that the overall experience of the writing group was a positive one, with each group presenting varied ‘success’ aspects as well as challenges. Insights gleaned may contribute to our understanding of how these groups can be utilised to support postgraduate students and how different kinds of groups can be developed to serve particular student needs. The paper concludes with a discussion of the inclusion of a disciplinary expert, which proved particularly useful in this pilot.
- Full Text: false
- Date Issued: 2018
Knockdown of Hop downregulates RhoC expression, and decreases pseudopodia formation and migration in cancer cell lines:
- Willmer, Tarryn, Contu, Lara, Blatch, Gregory L, Edkins, Adrienne L
- Authors: Willmer, Tarryn , Contu, Lara , Blatch, Gregory L , Edkins, Adrienne L
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165196 , vital:41217 , DOI: 10.1016/j.canlet.2012.09.021
- Description: The Hsp90/Hsp70 organising protein (Hop) is a co-chaperone that mediates the interaction of Hsp90 and Hsp70 molecular chaperones during assembly of Hsp90 complexes in cells. Formation of Hsp90 complexes is a key intermediate step in the maturation and homeostasis of oncoproteins and several hormone receptors. In this paper, we demonstrate that knockdown of Hop decreased migration of Hs578T and MDA-MB-231 breast cancer cells. Hop was identified in isolated pseudopodia fractions; it colocalised with actin in lamellipodia, and co-sedimented with purified actin in vitro. Knockdown of Hop caused a decrease in the level of RhoC GTPase, and significantly inhibited pseudopodia formation in Hs578T cells. Our data suggest that Hop regulates directional cell migration by multiple unknown mechanisms.
- Full Text:
- Date Issued: 2013
- Authors: Willmer, Tarryn , Contu, Lara , Blatch, Gregory L , Edkins, Adrienne L
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165196 , vital:41217 , DOI: 10.1016/j.canlet.2012.09.021
- Description: The Hsp90/Hsp70 organising protein (Hop) is a co-chaperone that mediates the interaction of Hsp90 and Hsp70 molecular chaperones during assembly of Hsp90 complexes in cells. Formation of Hsp90 complexes is a key intermediate step in the maturation and homeostasis of oncoproteins and several hormone receptors. In this paper, we demonstrate that knockdown of Hop decreased migration of Hs578T and MDA-MB-231 breast cancer cells. Hop was identified in isolated pseudopodia fractions; it colocalised with actin in lamellipodia, and co-sedimented with purified actin in vitro. Knockdown of Hop caused a decrease in the level of RhoC GTPase, and significantly inhibited pseudopodia formation in Hs578T cells. Our data suggest that Hop regulates directional cell migration by multiple unknown mechanisms.
- Full Text:
- Date Issued: 2013
Docking of HIV protease to silver nanoparticles
- Whiteley, Chris G, Shing, C-Y, Kuo, C-C, Lee, Duu-Jong
- Authors: Whiteley, Chris G , Shing, C-Y , Kuo, C-C , Lee, Duu-Jong
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67105 , vital:29032 , https://doi.org/10.1016/j.jtice.2015.10.029
- Description: publisher version , This interaction of silver nanoparticles (AgNP) with human immune-deficiency virus aspartic protease (HIVPR) is examined by molecular dynamics simulation using the Colores (Situs) package and biophysical techniques using UV–vis spectroscopy, dynamic light scattering, transmission electron microscopy and circular dichroism. The ‘docking’ of AgNP with HIVPR creates a complex [AgNP–HIVPR] to initiate a hypochromic time-dependent red-shift for the surface plasmon resonance maximum. MD simulations reflect large perturbations to enzyme conformations by fluctuations of both rmsd and B-factors. Increase in changes to electrostatic potentials within the enzyme, especially, with chain B, suggest hydrophobic interactions for the binding of the AgNP. This is supported by changes to mainchain and sidechain dihedrals for many hydrophobic amino acid including Cys95, Trp6 and Trp42. Circular dichroism spectra reveal disappearance of α-helices and β-sheets and increase in random coil first from chain B then chain A. During initial stages of the interactive simulation the enzyme is conformational flexible to accommodate the AgNP, that docks with the enzyme under a cooperative mechanism, until a more stable structure is formed at convergence. There is a decrease in size of the HIVPR–AgNP complex measured by changes to the gyration radius supporting evidence that the AgNP associates, initially, with chain B.
- Full Text: false
- Date Issued: 2016
- Authors: Whiteley, Chris G , Shing, C-Y , Kuo, C-C , Lee, Duu-Jong
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67105 , vital:29032 , https://doi.org/10.1016/j.jtice.2015.10.029
- Description: publisher version , This interaction of silver nanoparticles (AgNP) with human immune-deficiency virus aspartic protease (HIVPR) is examined by molecular dynamics simulation using the Colores (Situs) package and biophysical techniques using UV–vis spectroscopy, dynamic light scattering, transmission electron microscopy and circular dichroism. The ‘docking’ of AgNP with HIVPR creates a complex [AgNP–HIVPR] to initiate a hypochromic time-dependent red-shift for the surface plasmon resonance maximum. MD simulations reflect large perturbations to enzyme conformations by fluctuations of both rmsd and B-factors. Increase in changes to electrostatic potentials within the enzyme, especially, with chain B, suggest hydrophobic interactions for the binding of the AgNP. This is supported by changes to mainchain and sidechain dihedrals for many hydrophobic amino acid including Cys95, Trp6 and Trp42. Circular dichroism spectra reveal disappearance of α-helices and β-sheets and increase in random coil first from chain B then chain A. During initial stages of the interactive simulation the enzyme is conformational flexible to accommodate the AgNP, that docks with the enzyme under a cooperative mechanism, until a more stable structure is formed at convergence. There is a decrease in size of the HIVPR–AgNP complex measured by changes to the gyration radius supporting evidence that the AgNP associates, initially, with chain B.
- Full Text: false
- Date Issued: 2016
Preliminary evidence for the organisation of a bacterial community by zooplanktivores at the top of an estuarine planktonic food web
- Wasserman, Ryan J, Matcher, Gwynneth F, Vink, Tim J F, Froneman, P William
- Authors: Wasserman, Ryan J , Matcher, Gwynneth F , Vink, Tim J F , Froneman, P William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68237 , vital:29222 , https://doi.org/10.1007/s00248-014-0505-3
- Description: Publisher version , As part of a larger investigation, the effect of apex predation on estuarine bacterial community structure, through trophic cascading, was investigated using experimental in situ mesocosms. Through either the removal (filtration) or addition of specific size classes of planktonic groups, four different trophic scenarios were established using estuarine water and its associated plankton. One such treatment represented a “natural” scenario in which stable apex predatory pressure was qualified. Water samples were collected over time from each of the treatments for bacterial community evaluation. These samples were assessed through pyrosequencing of the variable regions 4 and 5 of the bacterial 16S rRNA gene and analysed at the species operational taxonomic unit (OTU) level using a community procedure. The blue-green group dominated the samples, followed by Proteobacteria and Bacteroidetes. Samples were the most similar among treatments at the commencement of the experiment. While the bacterial communities sampled within each treatment changed over time, the deviation from initial appeared to be linked to the treatment trophic scenarios. The least temporal deviation-from-initial in bacterial community was found within the stable apex predatory pressure treatment. These findings are consistent with trophic cascade theory, whereby predators mediate interactions at multiple lower trophic levels with consequent repercussions for diversity.
- Full Text: false
- Date Issued: 2015
- Authors: Wasserman, Ryan J , Matcher, Gwynneth F , Vink, Tim J F , Froneman, P William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68237 , vital:29222 , https://doi.org/10.1007/s00248-014-0505-3
- Description: Publisher version , As part of a larger investigation, the effect of apex predation on estuarine bacterial community structure, through trophic cascading, was investigated using experimental in situ mesocosms. Through either the removal (filtration) or addition of specific size classes of planktonic groups, four different trophic scenarios were established using estuarine water and its associated plankton. One such treatment represented a “natural” scenario in which stable apex predatory pressure was qualified. Water samples were collected over time from each of the treatments for bacterial community evaluation. These samples were assessed through pyrosequencing of the variable regions 4 and 5 of the bacterial 16S rRNA gene and analysed at the species operational taxonomic unit (OTU) level using a community procedure. The blue-green group dominated the samples, followed by Proteobacteria and Bacteroidetes. Samples were the most similar among treatments at the commencement of the experiment. While the bacterial communities sampled within each treatment changed over time, the deviation from initial appeared to be linked to the treatment trophic scenarios. The least temporal deviation-from-initial in bacterial community was found within the stable apex predatory pressure treatment. These findings are consistent with trophic cascade theory, whereby predators mediate interactions at multiple lower trophic levels with consequent repercussions for diversity.
- Full Text: false
- Date Issued: 2015
Life-history characteristics of an age-validated established invasive African sharptooth catfish, Clarias gariepinus, population in a warm–temperate African impoundment
- Wartenberg, Reece, Weyl, Olaf L F, Booth, Anthony J, Winker, A Henning
- Authors: Wartenberg, Reece , Weyl, Olaf L F , Booth, Anthony J , Winker, A Henning
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124921 , vital:35710 , https://doi.10.3377/004.048.0225
- Description: African sharptooth catfish Clarias gariepinus (Burchell, 1822) is a widely distributed fish that has now invaded water bodies in South America, Eastern Europe, Asia and South Africa (Cambray 2003). In South Africa it is native as far south as the Orange-Vaal river system, but inter-basin water transfer schemes (IBWTs), illegal stocking by anglers and from aquaculture has resulted in the establishment of extralimital populations in almost all river systems (van Rensburg et al. 2011). Within the Eastern Cape Province, C. gariepinus has invaded the Great Fish and Sundays rivers through IBWTs, that connect the Orange River to the Great Fish River and then to the Sundays River system which flows directly into Darlington Dam (Kadye & Booth 2013a) (Fig. 1). Soon after the completion of the IBWTs sharptooth catfish were recorded in Grassridge Dam in 1976 (Laurenson & Hocutt 1985), and later from Darlington Dam in 1981 (Scott et al. 2006). Although Cambray & Jubb (1977) are of the opinion that the species was translocated prior to the IBWT connection, there is now a permanent corridor between the Orange River and its receiving river systems that can facilitate the continued introduction of non-native Orange River fishes and other aquatic biota.
- Full Text:
- Date Issued: 2012
- Authors: Wartenberg, Reece , Weyl, Olaf L F , Booth, Anthony J , Winker, A Henning
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124921 , vital:35710 , https://doi.10.3377/004.048.0225
- Description: African sharptooth catfish Clarias gariepinus (Burchell, 1822) is a widely distributed fish that has now invaded water bodies in South America, Eastern Europe, Asia and South Africa (Cambray 2003). In South Africa it is native as far south as the Orange-Vaal river system, but inter-basin water transfer schemes (IBWTs), illegal stocking by anglers and from aquaculture has resulted in the establishment of extralimital populations in almost all river systems (van Rensburg et al. 2011). Within the Eastern Cape Province, C. gariepinus has invaded the Great Fish and Sundays rivers through IBWTs, that connect the Orange River to the Great Fish River and then to the Sundays River system which flows directly into Darlington Dam (Kadye & Booth 2013a) (Fig. 1). Soon after the completion of the IBWTs sharptooth catfish were recorded in Grassridge Dam in 1976 (Laurenson & Hocutt 1985), and later from Darlington Dam in 1981 (Scott et al. 2006). Although Cambray & Jubb (1977) are of the opinion that the species was translocated prior to the IBWT connection, there is now a permanent corridor between the Orange River and its receiving river systems that can facilitate the continued introduction of non-native Orange River fishes and other aquatic biota.
- Full Text:
- Date Issued: 2012
Application of the Minolta chromameter to the assessment of corticosteroid-induced skin blanching
- Walker, Roderick B, Haigh, John M, Smith, Eric W
- Authors: Walker, Roderick B , Haigh, John M , Smith, Eric W
- Date: 2000
- Language: English
- Type: Book chapter , text
- Identifier: vital:6451 , http://hdl.handle.net/10962/d1006639
- Full Text:
- Date Issued: 2000
- Authors: Walker, Roderick B , Haigh, John M , Smith, Eric W
- Date: 2000
- Language: English
- Type: Book chapter , text
- Identifier: vital:6451 , http://hdl.handle.net/10962/d1006639
- Full Text:
- Date Issued: 2000
Kappia lobulata (Apocynaceae, Periplocoideae), a new genus from South Africa
- Venter, H J T, Dold, Anthony P, Verhoeven, R L, Ionta, G
- Authors: Venter, H J T , Dold, Anthony P , Verhoeven, R L , Ionta, G
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6556 , http://hdl.handle.net/10962/d1006015
- Description: Kappia, a new genus from the Fish River Valley in the Eastern Cape Province, South Africa is presented. At first described as Raphionacme lobulata Venter and R.L.Verh. [Venter, H.J.T., Verhoeven, R.L. 1988. Raphionacme lobulata (Periplocaceae), a new species from the eastern Cape Province, South Africa. South African Journal of Botany 54, 603–606.] based on a single specimen collected in 1936, recently discovered plants of this species proved it to be a new genus. In habit Kappia resembles Baseonema Schltr. and Rendle, Batesanthus N.E.Br., Mondia Skeels and Stomatostemma N.E.Br. However, as far as floral structure is concerned, Kappia reveals more affinity with Raphionacme Harv. DNA sequence data show Kappia to be distinct from Batesanthus, Mondia and Raphionacme Harv. and weakly supported as a sister to Stomatostemma.
- Full Text:
- Date Issued: 2006
- Authors: Venter, H J T , Dold, Anthony P , Verhoeven, R L , Ionta, G
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6556 , http://hdl.handle.net/10962/d1006015
- Description: Kappia, a new genus from the Fish River Valley in the Eastern Cape Province, South Africa is presented. At first described as Raphionacme lobulata Venter and R.L.Verh. [Venter, H.J.T., Verhoeven, R.L. 1988. Raphionacme lobulata (Periplocaceae), a new species from the eastern Cape Province, South Africa. South African Journal of Botany 54, 603–606.] based on a single specimen collected in 1936, recently discovered plants of this species proved it to be a new genus. In habit Kappia resembles Baseonema Schltr. and Rendle, Batesanthus N.E.Br., Mondia Skeels and Stomatostemma N.E.Br. However, as far as floral structure is concerned, Kappia reveals more affinity with Raphionacme Harv. DNA sequence data show Kappia to be distinct from Batesanthus, Mondia and Raphionacme Harv. and weakly supported as a sister to Stomatostemma.
- Full Text:
- Date Issued: 2006
Application of quality by design principles for optimizing process variables of Extrusion and Spheronization of a Captopril Pellet Formulation:
- Veerubhotla, Krishna, Walker, Roderick B
- Authors: Veerubhotla, Krishna , Walker, Roderick B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/178312 , vital:40098 , DOI: 10.36468/pharmaceutical-sciences.624
- Description: Product development using quality by design is a proactive and risk-based approach that shifts the manufacturing process from empirical to science-based. Risk assessment was performed to identify and analyse risk areas for the manufacture of captopril pellets. Twelve experimental runs were performed using a Plackett-Burman screening design. Pareto plots revealed the effect of formulation and process variables on the responses monitored and facilitated the identification of the most critical parameters for optimization of the formulation. A response surface methodology approach in conjunction with a central composite design was used to optimize the Eudragit® RL 30D (15-30 ml), microcrystalline cellulose (20-40 % w/w), sodium starch glycolate (2-5 % w/w) and spheronizer speed (650-1050 rpm).
- Full Text:
- Date Issued: 2020
- Authors: Veerubhotla, Krishna , Walker, Roderick B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/178312 , vital:40098 , DOI: 10.36468/pharmaceutical-sciences.624
- Description: Product development using quality by design is a proactive and risk-based approach that shifts the manufacturing process from empirical to science-based. Risk assessment was performed to identify and analyse risk areas for the manufacture of captopril pellets. Twelve experimental runs were performed using a Plackett-Burman screening design. Pareto plots revealed the effect of formulation and process variables on the responses monitored and facilitated the identification of the most critical parameters for optimization of the formulation. A response surface methodology approach in conjunction with a central composite design was used to optimize the Eudragit® RL 30D (15-30 ml), microcrystalline cellulose (20-40 % w/w), sodium starch glycolate (2-5 % w/w) and spheronizer speed (650-1050 rpm).
- Full Text:
- Date Issued: 2020
A continuous process for the biological treatment of heavy metal contaminated acid mine water
- Van Hille, R P, Boshoff, G A, Rose, P D, Duncan, J R
- Authors: Van Hille, R P , Boshoff, G A , Rose, P D , Duncan, J R
- Date: 1999
- Language: English
- Type: Article
- Identifier: vital:6464 , http://hdl.handle.net/10962/d1005793 , dx.doi.org/10.1016/S0921-3449(99)00010-5
- Description: Alkaline precipitation of heavy metals from acidic water streams is a popular and long standing treatment process. While this process is efficient it requires the continuous addition of an alkaline material, such as lime. In the long term or when treating large volumes of effluent this process becomes expensive, with costs in the mining sector routinely exceeding millions of rands annually. The process described below utilises alkalinity generated by the alga Spirulina sp., in a continuous system to precipitate heavy metals. The design of the system separates the algal component from the metal containing stream to overcome metal toxicity. The primary treatment process consistently removed over 99% of the iron (98.9 mg/l) and between 80 and 95% of the zinc (7.16 mg/l) and lead (2.35 mg/l) over a 14-day period (20 l effluent treated). In addition the pH of the raw effluent was increased from 1.8 to over 7 in the post-treatment stream. Secondary treatment and polishing steps depend on the nature of the effluent treated. In the case of the high sulphate effluent the treated stream was passed into an anaerobic digester at a rate of 4 l/day. The combination of the primary and secondary treatments effected a removal of over 95% of all metals tested for as well as a 90% reduction in the sulphate load. The running cost of such a process would be low as the salinity and nutrient requirements for the algal culture could be provided by using tannery effluent or a combination of saline water and sewage. This would have the additional benefit of treating either a tannery or sewage effluent as part of an integrated process.
- Full Text:
- Date Issued: 1999
- Authors: Van Hille, R P , Boshoff, G A , Rose, P D , Duncan, J R
- Date: 1999
- Language: English
- Type: Article
- Identifier: vital:6464 , http://hdl.handle.net/10962/d1005793 , dx.doi.org/10.1016/S0921-3449(99)00010-5
- Description: Alkaline precipitation of heavy metals from acidic water streams is a popular and long standing treatment process. While this process is efficient it requires the continuous addition of an alkaline material, such as lime. In the long term or when treating large volumes of effluent this process becomes expensive, with costs in the mining sector routinely exceeding millions of rands annually. The process described below utilises alkalinity generated by the alga Spirulina sp., in a continuous system to precipitate heavy metals. The design of the system separates the algal component from the metal containing stream to overcome metal toxicity. The primary treatment process consistently removed over 99% of the iron (98.9 mg/l) and between 80 and 95% of the zinc (7.16 mg/l) and lead (2.35 mg/l) over a 14-day period (20 l effluent treated). In addition the pH of the raw effluent was increased from 1.8 to over 7 in the post-treatment stream. Secondary treatment and polishing steps depend on the nature of the effluent treated. In the case of the high sulphate effluent the treated stream was passed into an anaerobic digester at a rate of 4 l/day. The combination of the primary and secondary treatments effected a removal of over 95% of all metals tested for as well as a 90% reduction in the sulphate load. The running cost of such a process would be low as the salinity and nutrient requirements for the algal culture could be provided by using tannery effluent or a combination of saline water and sewage. This would have the additional benefit of treating either a tannery or sewage effluent as part of an integrated process.
- Full Text:
- Date Issued: 1999
Privacy risk and the use of Facebook Apps: a gender-focused vulnerability assessment
- van der Schyff, Karl, Flowerday, Stephen, Furnell, Steven
- Authors: van der Schyff, Karl , Flowerday, Stephen , Furnell, Steven
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149054 , vital:38800 , https://doi.org/10.1016/j.cose.2020.101866
- Description: The surveillance and subsequent privacy risks (i.e., misuse of personal information) of Facebook App data constitute a persistent problem that affects millions of users. However, despite Facebook App research on specifics such as privacy concerns, value of information, and demographics, none of them has conducted vulnerability assessments on the use of Facebook Apps as influenced by specific factors such as age, gender, and information privacy attitudes. As such, the purpose of this study was to predict the extent to which these factors influence an individual's intention to continue using Facebook Apps as part of a gender-focused vulnerability assessment. We evaluate two hypotheses by way of ordinal logistic regression using data gathered from 621 respondents. The results are indicative of the following: First, females are particularly vulnerable to privacy risks as a function of continued use of Facebook Apps. More specifically, those risks related to Facebook's access to personal information. Second, results indicate that a user's age is nonsignificant in relation to the continued use of Facebook Apps. We conclude with several theoretical and practice-oriented information privacy recommendations.
- Full Text:
- Date Issued: 2020
- Authors: van der Schyff, Karl , Flowerday, Stephen , Furnell, Steven
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149054 , vital:38800 , https://doi.org/10.1016/j.cose.2020.101866
- Description: The surveillance and subsequent privacy risks (i.e., misuse of personal information) of Facebook App data constitute a persistent problem that affects millions of users. However, despite Facebook App research on specifics such as privacy concerns, value of information, and demographics, none of them has conducted vulnerability assessments on the use of Facebook Apps as influenced by specific factors such as age, gender, and information privacy attitudes. As such, the purpose of this study was to predict the extent to which these factors influence an individual's intention to continue using Facebook Apps as part of a gender-focused vulnerability assessment. We evaluate two hypotheses by way of ordinal logistic regression using data gathered from 621 respondents. The results are indicative of the following: First, females are particularly vulnerable to privacy risks as a function of continued use of Facebook Apps. More specifically, those risks related to Facebook's access to personal information. Second, results indicate that a user's age is nonsignificant in relation to the continued use of Facebook Apps. We conclude with several theoretical and practice-oriented information privacy recommendations.
- Full Text:
- Date Issued: 2020
Metabolic responses to various combinations of gradient, load and marching speed
- Todd, Andrew I, Scott, Patricia A
- Authors: Todd, Andrew I , Scott, Patricia A
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6751 , http://hdl.handle.net/10962/d1009331
- Description: This study examined the metabolic cost of South African soldiers carrying loads under various conditions of gradient and marching speed. Thirty-two male soldiers participated in the study. Three speed and load combinations, 4, 5 and 6 km.h[superscript (-1)] carrying of 50, 35 and 20 kg respectively, were imposed, on each of three gradients: -10%, 0% and +10%; a total of nine experimental conditions. Subjects wore standardized military uniforms and breathed into a portable ergospirometer (Metamax) for the duration of each condition. Subjects were required to march for six minutes under each condition, and metabolic responses were monitored during the third and sixth minute of each condition. The metabolic responses to the three level marching conditions showed no significant differences. Marching uphill resulted in a significant increase in metabolic demands under all three speed and load onditions. Downhill marching elicited significant decreases only under the two lighter load conditions. Downhill marching with heavy loads appears to show no reduction in metabolic demands placed on soldiers.
- Full Text:
- Date Issued: 2002
- Authors: Todd, Andrew I , Scott, Patricia A
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6751 , http://hdl.handle.net/10962/d1009331
- Description: This study examined the metabolic cost of South African soldiers carrying loads under various conditions of gradient and marching speed. Thirty-two male soldiers participated in the study. Three speed and load combinations, 4, 5 and 6 km.h[superscript (-1)] carrying of 50, 35 and 20 kg respectively, were imposed, on each of three gradients: -10%, 0% and +10%; a total of nine experimental conditions. Subjects wore standardized military uniforms and breathed into a portable ergospirometer (Metamax) for the duration of each condition. Subjects were required to march for six minutes under each condition, and metabolic responses were monitored during the third and sixth minute of each condition. The metabolic responses to the three level marching conditions showed no significant differences. Marching uphill resulted in a significant increase in metabolic demands under all three speed and load onditions. Downhill marching elicited significant decreases only under the two lighter load conditions. Downhill marching with heavy loads appears to show no reduction in metabolic demands placed on soldiers.
- Full Text:
- Date Issued: 2002
Contributions of the pars lateralis, pars basilaris and femur to age estimations of the immature skeleton within a South African forensic setting:
- Thornton, Roxanne, Edkins, Adrienne L, Hutchinson, E F
- Authors: Thornton, Roxanne , Edkins, Adrienne L , Hutchinson, E F
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165451 , vital:41245 , https://0-doi.org.wam.seals.ac.za/10.1007/s00414-019-02143-9
- Description: Dental development and eruption sequences have prevailed as the gold standard in age estimations of previously unidentified immature individuals within a legal context. However, in the absence of the dentition, skeletal assessments have served as a frequently applied alternative. While various cranial and postcranial skeletal elements have been used in estimating age of the immature skeleton, little is known about the anthropometric value of the pars basilaris, pars lateralis and femur as skeletal age estimation tools. Thus, this study aimed to assess if these bones of the immature human skeleton were useful elements in estimating the age of prenatal and postnatal individuals. These bones were excised from the remains of 74 unclaimed human immature individuals and evaluated using traditional anthropometric methods. The study sample was sourced from the Johannesburg Forensic Pathology Services (JFPS) and the Johannesburg Forensic Paediatric Collection (JFPC), University of the Witwatersrand and subdivided into an early prenatal (younger than 30 gestational weeks); late prenatal (30 to 40 gestational weeks) and postnatal (birth to 7.5 months) age ranges.
- Full Text:
- Date Issued: 2020
- Authors: Thornton, Roxanne , Edkins, Adrienne L , Hutchinson, E F
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165451 , vital:41245 , https://0-doi.org.wam.seals.ac.za/10.1007/s00414-019-02143-9
- Description: Dental development and eruption sequences have prevailed as the gold standard in age estimations of previously unidentified immature individuals within a legal context. However, in the absence of the dentition, skeletal assessments have served as a frequently applied alternative. While various cranial and postcranial skeletal elements have been used in estimating age of the immature skeleton, little is known about the anthropometric value of the pars basilaris, pars lateralis and femur as skeletal age estimation tools. Thus, this study aimed to assess if these bones of the immature human skeleton were useful elements in estimating the age of prenatal and postnatal individuals. These bones were excised from the remains of 74 unclaimed human immature individuals and evaluated using traditional anthropometric methods. The study sample was sourced from the Johannesburg Forensic Pathology Services (JFPS) and the Johannesburg Forensic Paediatric Collection (JFPC), University of the Witwatersrand and subdivided into an early prenatal (younger than 30 gestational weeks); late prenatal (30 to 40 gestational weeks) and postnatal (birth to 7.5 months) age ranges.
- Full Text:
- Date Issued: 2020
Local institutions, actors, and natural resource governance in Kgalagadi Transfrontier Park and surrounds, South Africa
- Thondhlana, Gladman, Shackleton, Sheona E, Blignaut, James
- Authors: Thondhlana, Gladman , Shackleton, Sheona E , Blignaut, James
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67689 , vital:29130 , https://doi.org/10.1016/j.landusepol.2015.03.013
- Description: Publisher version , Crafting local institutions to allow more effective decision-making in the management of and access to natural resources in and beyond parks has long been considered key to collaborative governance. South Africa, in particular, has vigorously pursued collaborative governance as a desired approach to managing natural resources as evident in the new arrangements for previously restricted parks. However, though the discourse of collaborative governance has occupied conservation thinking and practice globally, few studies have looked at the interplay between local institutions, actors and collaborative governance involving indigenous hunter–gatherer communities in Southern Africa. In response, we assess the local actors and institutions that were put in place to facilitate collaborative governance of natural resources in the Kgalagadi Transfrontier Park and its surrounds in South Africa. Our findings show that though collaborative governance has a practical appeal, it is hampered by lack of participation in decision-making, information dissemination, transparency, trust and accountability, power relations, divergent interests and unequal access to natural resources. The findings also draw our attention to issues of heterogeneity, even within indigenous communities assumed to be homogenous by local conservation authorities as reflected in land settlement agreements in co-managed parks. We argue that collaborative governance arrangements need to reflect and be understood within the broader background of complex local realities.
- Full Text: false
- Date Issued: 2015
- Authors: Thondhlana, Gladman , Shackleton, Sheona E , Blignaut, James
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67689 , vital:29130 , https://doi.org/10.1016/j.landusepol.2015.03.013
- Description: Publisher version , Crafting local institutions to allow more effective decision-making in the management of and access to natural resources in and beyond parks has long been considered key to collaborative governance. South Africa, in particular, has vigorously pursued collaborative governance as a desired approach to managing natural resources as evident in the new arrangements for previously restricted parks. However, though the discourse of collaborative governance has occupied conservation thinking and practice globally, few studies have looked at the interplay between local institutions, actors and collaborative governance involving indigenous hunter–gatherer communities in Southern Africa. In response, we assess the local actors and institutions that were put in place to facilitate collaborative governance of natural resources in the Kgalagadi Transfrontier Park and its surrounds in South Africa. Our findings show that though collaborative governance has a practical appeal, it is hampered by lack of participation in decision-making, information dissemination, transparency, trust and accountability, power relations, divergent interests and unequal access to natural resources. The findings also draw our attention to issues of heterogeneity, even within indigenous communities assumed to be homogenous by local conservation authorities as reflected in land settlement agreements in co-managed parks. We argue that collaborative governance arrangements need to reflect and be understood within the broader background of complex local realities.
- Full Text: false
- Date Issued: 2015
Non-material costs of wildlife conservation to local people and their implications for conservation interventions:
- Thondhlana, Gladman, Redpath, Stephen Mark, Vedeld, Pål Olav, van Eden, Lily, Pascual, Unai, Sherren, Kate, Murata, Chenai
- Authors: Thondhlana, Gladman , Redpath, Stephen Mark , Vedeld, Pål Olav , van Eden, Lily , Pascual, Unai , Sherren, Kate , Murata, Chenai
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150174 , vital:38946 , https://doi.org/10.1016/j.biocon.2020.108578
- Description: In assessment of costs (and benefits) of wildlife conservation, conventional economic valuation frameworks may inadequately address various non-tangible values and neglect social, cultural and political contexts of resources and their use. Correspondingly, there seems to be much more focus on quantifying the economic, material benefits and costs of wildlife conservation than the non-material aspects that also affect human well-being. In addition, current research on the costs of wildlife conservation tends to be discipline-focused which constrains comparability, often causing conceptual ambiguity. This paper is an attempt to address this ambiguity. While there is growing acknowledgement of the material costs of wildlife conservation, we contend that employing a broader, composite social well-being approach may provide better conceptual insights on—and practical options for—managing various non-material impacts of wildlife conservation for local people.
- Full Text:
- Date Issued: 2020
- Authors: Thondhlana, Gladman , Redpath, Stephen Mark , Vedeld, Pål Olav , van Eden, Lily , Pascual, Unai , Sherren, Kate , Murata, Chenai
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150174 , vital:38946 , https://doi.org/10.1016/j.biocon.2020.108578
- Description: In assessment of costs (and benefits) of wildlife conservation, conventional economic valuation frameworks may inadequately address various non-tangible values and neglect social, cultural and political contexts of resources and their use. Correspondingly, there seems to be much more focus on quantifying the economic, material benefits and costs of wildlife conservation than the non-material aspects that also affect human well-being. In addition, current research on the costs of wildlife conservation tends to be discipline-focused which constrains comparability, often causing conceptual ambiguity. This paper is an attempt to address this ambiguity. While there is growing acknowledgement of the material costs of wildlife conservation, we contend that employing a broader, composite social well-being approach may provide better conceptual insights on—and practical options for—managing various non-material impacts of wildlife conservation for local people.
- Full Text:
- Date Issued: 2020
Dependence on environmental resources and implications for household welfare: evidence from the Kalahari drylands, South Africa
- Thondhlana, Gladman, Muchapondwa, Edwin
- Authors: Thondhlana, Gladman , Muchapondwa, Edwin
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67810 , vital:29149 , https://doi.org/10.1016/j.ecolecon.2014.10.003
- Description: Publisher version , This paper examines dependence on environmental resources and impacts on household welfare among the indigenous San and Mier rural communities neighbouring Kgalagadi Transfrontier Park in South Africa. Data on the various household income types, including environmental income, were collected through a structured survey of 200 households. Environmental income constituted 20% of the total income. The poorest income quintile showed the highest relative dependence on environmental income (31%), though absolute environmental income increased with total income. Poverty analyses showed that poverty incidence and poverty gap would increase by 13 and 7 percentage points respectively without environmental income. Gini-coefficient analyses revealed that income inequality would increase by 6 percentage points for all households if environmental income was excluded. The results generally suggest that environmental income is important for both the poor and the well-off, and wealth accumulation might be tied to resource use. There is a case for promoting sound environmental management, and sustainable and fair resource use in the Kalahari drylands in order to help pull more households out of poverty. Our findings also point to issues of heterogeneity in resource access even among indigenous communities previously thought to be homogenous. These should be key considerations for conservation interventions.
- Full Text: false
- Date Issued: 2014
- Authors: Thondhlana, Gladman , Muchapondwa, Edwin
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67810 , vital:29149 , https://doi.org/10.1016/j.ecolecon.2014.10.003
- Description: Publisher version , This paper examines dependence on environmental resources and impacts on household welfare among the indigenous San and Mier rural communities neighbouring Kgalagadi Transfrontier Park in South Africa. Data on the various household income types, including environmental income, were collected through a structured survey of 200 households. Environmental income constituted 20% of the total income. The poorest income quintile showed the highest relative dependence on environmental income (31%), though absolute environmental income increased with total income. Poverty analyses showed that poverty incidence and poverty gap would increase by 13 and 7 percentage points respectively without environmental income. Gini-coefficient analyses revealed that income inequality would increase by 6 percentage points for all households if environmental income was excluded. The results generally suggest that environmental income is important for both the poor and the well-off, and wealth accumulation might be tied to resource use. There is a case for promoting sound environmental management, and sustainable and fair resource use in the Kalahari drylands in order to help pull more households out of poverty. Our findings also point to issues of heterogeneity in resource access even among indigenous communities previously thought to be homogenous. These should be key considerations for conservation interventions.
- Full Text: false
- Date Issued: 2014
Rhodes University Library Annual Report 2009: Library Director’s Review
- Authors: Thomas, G M E
- Date: 2009
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/59941 , vital:27713
- Description: [From the Introduction] As you read through this annual overview of the work carried out by the staff of the Rhodes University Library Services Division, I am sure you will be impressed by their achievements during a year marked by major building construction and a demanding institutional review of our services and staffing structures.
- Full Text:
- Date Issued: 2009
- Authors: Thomas, G M E
- Date: 2009
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/59941 , vital:27713
- Description: [From the Introduction] As you read through this annual overview of the work carried out by the staff of the Rhodes University Library Services Division, I am sure you will be impressed by their achievements during a year marked by major building construction and a demanding institutional review of our services and staffing structures.
- Full Text:
- Date Issued: 2009
Phylogeographic structure of Octopus vulgaris in South Africa revisited: identification of a second lineage near Durban harbour
- Teske, P R, Oosthuizen, A, Papadopoulos, I, Barker, Nigel P
- Authors: Teske, P R , Oosthuizen, A , Papadopoulos, I , Barker, Nigel P
- Date: 2007
- Language: English
- Type: text , article
- Identifier: vital:6951 , http://hdl.handle.net/10962/d1013236 , http://dx.doi.org/10.1007/s00227-007-0644-x
- Description: preprint , In a previous study that investigated genetic structure of Octopus vulgaris along the South African coast by sequencing the mitochondrial cytochrome oxidase III gene (COIII), all sequences generated were identical. Such a finding is unusual, because mitochondrial DNA mutates quickly, and several marine invertebrates present in southern Africa show considerable genetic variation and structure. We reanalysed the samples using two different mitochondrial markers, namely cytochrome oxidase I (COI) and the large ribosomal subunit (16S rRNA). Sequences of both these markers showed variation. The conclusion of the previous study, that South Africa’s O. vulgaris population is characterised by a lack of genetic structure along the coast, is rejected. Some specimens from Durban (southeast Africa) were genetically more different from those found in the remainder of the country than were specimens from other regions (Tristan da Cunha and Senegal). We suggest that the lineage in Durban may have been recently introduced.
- Full Text:
- Date Issued: 2007
- Authors: Teske, P R , Oosthuizen, A , Papadopoulos, I , Barker, Nigel P
- Date: 2007
- Language: English
- Type: text , article
- Identifier: vital:6951 , http://hdl.handle.net/10962/d1013236 , http://dx.doi.org/10.1007/s00227-007-0644-x
- Description: preprint , In a previous study that investigated genetic structure of Octopus vulgaris along the South African coast by sequencing the mitochondrial cytochrome oxidase III gene (COIII), all sequences generated were identical. Such a finding is unusual, because mitochondrial DNA mutates quickly, and several marine invertebrates present in southern Africa show considerable genetic variation and structure. We reanalysed the samples using two different mitochondrial markers, namely cytochrome oxidase I (COI) and the large ribosomal subunit (16S rRNA). Sequences of both these markers showed variation. The conclusion of the previous study, that South Africa’s O. vulgaris population is characterised by a lack of genetic structure along the coast, is rejected. Some specimens from Durban (southeast Africa) were genetically more different from those found in the remainder of the country than were specimens from other regions (Tristan da Cunha and Senegal). We suggest that the lineage in Durban may have been recently introduced.
- Full Text:
- Date Issued: 2007
Local government and coloured residential segregation in Port Elizabeth, 1964-1976
- Authors: Taylor, Beverley J
- Date: 1994
- Language: English
- Type: text , article
- Identifier: vital:7108 , https://doi.org/10.1080/03736245.1994.9713566 , http://hdl.handle.net/10962/d1010736
- Description: preprint , Studies of racial territorial segregation affecting the coloured population in Port Elizabeth tend to perceive it as an outcome of a power struggle between central and local government over the implementation of apartheid legislation. This paper explores the underlying economic forces on the local government to bring about residential segregation and address the coloured housing crisis in the city. It is proposed that whereas central government motives for segregation were primarily political, local government was influenced largely by economic considerations. Local government objectives were severely compromised through both local industrial interests and the implementation of central government Group Areas policies.
- Full Text:
- Date Issued: 1994
- Authors: Taylor, Beverley J
- Date: 1994
- Language: English
- Type: text , article
- Identifier: vital:7108 , https://doi.org/10.1080/03736245.1994.9713566 , http://hdl.handle.net/10962/d1010736
- Description: preprint , Studies of racial territorial segregation affecting the coloured population in Port Elizabeth tend to perceive it as an outcome of a power struggle between central and local government over the implementation of apartheid legislation. This paper explores the underlying economic forces on the local government to bring about residential segregation and address the coloured housing crisis in the city. It is proposed that whereas central government motives for segregation were primarily political, local government was influenced largely by economic considerations. Local government objectives were severely compromised through both local industrial interests and the implementation of central government Group Areas policies.
- Full Text:
- Date Issued: 1994