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
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
Benthic diatom-based indices and isotopic biomonitoring of nitrogen pollution in a warm temperate Austral river system
- Dalu, Tatenda, Cuthbert, Ross N, Taylor, Jonathan C, Magoro, Mandla L, Weyl, Olaf L F, Froneman, P William, Wasserman, Ryan J
- Authors: Dalu, Tatenda , Cuthbert, Ross N , Taylor, Jonathan C , Magoro, Mandla L , Weyl, Olaf L F , Froneman, P William , Wasserman, Ryan J
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/466917 , vital:76798 , https://doi.org/10.1016/j.scitotenv.2020.142452
- Description: Rivers are impacted by pollutants from anthropogenic activities such as urbanisation and agricultural practices. Whilst point source pollution has been widely studied and in some cases remediated, non-point pollutant sources remain pervasive, particularly in developing countries that lack economic and human specialist capacity. Monitoring of pollution levels in many regions is additionally challenged by a lack of robust indicators for nitrogen inputs, however, diatom community indices and analysis of variation in microphytobenthos (MBP) stable isotope analysis variations have potential. The present study investigates variations and utilities in benthic diatom indices and MPB δ15N along different river sections (n = 31) of an austral river between two seasons (wet and dry), testing for relationships with key environmental variables (physical, water and sediment), in the context of N monitoring. One hundred and eighteen diatom taxa belonging to 36 genera were identified, with physical (water flow), water (nitrate, P and total dissolved solids) and sediment (B, Ca, Cr, Na, N, P, SOM, Pb and Zn) variables correlating to one or more of the 12 diatom indices presented. In particular, Biological Diatom Index, Biological Index of Water Quality, Central Economic Community, Index of Artois-Picardie Diatom (IDAP) and Sládeček's Index were strongly explained by sediment variables, whilst Descy's Pollution Index and Schiefele and Schreiner's Index were explained by water and physical variables.
- Full Text:
- Date Issued: 2020
- Authors: Dalu, Tatenda , Cuthbert, Ross N , Taylor, Jonathan C , Magoro, Mandla L , Weyl, Olaf L F , Froneman, P William , Wasserman, Ryan J
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/466917 , vital:76798 , https://doi.org/10.1016/j.scitotenv.2020.142452
- Description: Rivers are impacted by pollutants from anthropogenic activities such as urbanisation and agricultural practices. Whilst point source pollution has been widely studied and in some cases remediated, non-point pollutant sources remain pervasive, particularly in developing countries that lack economic and human specialist capacity. Monitoring of pollution levels in many regions is additionally challenged by a lack of robust indicators for nitrogen inputs, however, diatom community indices and analysis of variation in microphytobenthos (MBP) stable isotope analysis variations have potential. The present study investigates variations and utilities in benthic diatom indices and MPB δ15N along different river sections (n = 31) of an austral river between two seasons (wet and dry), testing for relationships with key environmental variables (physical, water and sediment), in the context of N monitoring. One hundred and eighteen diatom taxa belonging to 36 genera were identified, with physical (water flow), water (nitrate, P and total dissolved solids) and sediment (B, Ca, Cr, Na, N, P, SOM, Pb and Zn) variables correlating to one or more of the 12 diatom indices presented. In particular, Biological Diatom Index, Biological Index of Water Quality, Central Economic Community, Index of Artois-Picardie Diatom (IDAP) and Sládeček's Index were strongly explained by sediment variables, whilst Descy's Pollution Index and Schiefele and Schreiner's Index were explained by water and physical variables.
- Full Text:
- Date Issued: 2020
Climate modelling suggests a review of the legal status of Brazilian pepper Schinus terebinthifolia in South Africa is required:
- Martin, Grant D, Magengelele, Nwabisa L, Paterson, Iain D, Sutton, Guy F
- Authors: Martin, Grant D , Magengelele, Nwabisa L , Paterson, Iain D , Sutton, Guy F
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148606 , vital:38754 , https://doi.org/10.1016/j.sajb.2020.04.019
- Description: Brazilian pepper (Schinus terebinthifolia) is a tree native to subtropical South America that was introduced into South Africa in the early 1900s as an ornamental plant. The tree has since escaped cultivation and has invaded ruderal and pristine habitats along the eastern coast of South Africa. Brazilian Pepper is also one of the most problematic invasive alien plants in Florida, USA. We modelled the climatically suitable area for this species in South Africa using MaxEnt, with five distinct datasets: incorporating both the native and the invaded range of the species, as well as different backgrounds.
- Full Text:
- Date Issued: 2020
- Authors: Martin, Grant D , Magengelele, Nwabisa L , Paterson, Iain D , Sutton, Guy F
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148606 , vital:38754 , https://doi.org/10.1016/j.sajb.2020.04.019
- Description: Brazilian pepper (Schinus terebinthifolia) is a tree native to subtropical South America that was introduced into South Africa in the early 1900s as an ornamental plant. The tree has since escaped cultivation and has invaded ruderal and pristine habitats along the eastern coast of South Africa. Brazilian Pepper is also one of the most problematic invasive alien plants in Florida, USA. We modelled the climatically suitable area for this species in South Africa using MaxEnt, with five distinct datasets: incorporating both the native and the invaded range of the species, as well as different backgrounds.
- Full Text:
- Date Issued: 2020
Common dolphin Delphinus delphis occurrence off the Wild Coast of South Africa
- Caputo, Michelle, Froneman, P William, Plön, Stephanie
- Authors: Caputo, Michelle , Froneman, P William , Plön, Stephanie
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/467255 , vital:76845 , https://doi.org/10.2989/1814232X.2020.1841676
- Description: Despite their typical large group sizes, limited research exists on the occurrence of common dolphins Delphinus delphis because of the pelagic, offshore nature of this species and the lack of barriers to their movement in this environment. The main purpose of our study was to investigate the occurrence of common dolphins off the Wild Coast of South Africa (western Indian Ocean) and whether spatiotemporal and environmental conditions affected their encounter rate, relative abundance and mean group size. The annual sardine run in this region, during austral winter (May to July), is considered a main driver of dolphin occurrence; however, our boat-based surveys over the period 2014–2016 indicated that common dolphins occur and feed in this area outside of this time-frame. In terms of environmental factors, the largest group (∼1 250 animals) was found in the deepest waters. Additionally, at Hluleka, dolphins were observed primarily feeding, which could suggest that this coastal area is highly productive. As common dolphin distribution is thought to be correlated with prey distribution, our findings suggest that sufficient prey exists along the Wild Coast both during and outside the annual sardine run to sustain large groups of the dolphins and that their presence in the area is not solely a function of the sardine run.
- Full Text:
- Date Issued: 2020
- Authors: Caputo, Michelle , Froneman, P William , Plön, Stephanie
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/467255 , vital:76845 , https://doi.org/10.2989/1814232X.2020.1841676
- Description: Despite their typical large group sizes, limited research exists on the occurrence of common dolphins Delphinus delphis because of the pelagic, offshore nature of this species and the lack of barriers to their movement in this environment. The main purpose of our study was to investigate the occurrence of common dolphins off the Wild Coast of South Africa (western Indian Ocean) and whether spatiotemporal and environmental conditions affected their encounter rate, relative abundance and mean group size. The annual sardine run in this region, during austral winter (May to July), is considered a main driver of dolphin occurrence; however, our boat-based surveys over the period 2014–2016 indicated that common dolphins occur and feed in this area outside of this time-frame. In terms of environmental factors, the largest group (∼1 250 animals) was found in the deepest waters. Additionally, at Hluleka, dolphins were observed primarily feeding, which could suggest that this coastal area is highly productive. As common dolphin distribution is thought to be correlated with prey distribution, our findings suggest that sufficient prey exists along the Wild Coast both during and outside the annual sardine run to sustain large groups of the dolphins and that their presence in the area is not solely a function of the sardine run.
- Full Text:
- Date Issued: 2020
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
Dataset of experimental and adaptive neuro-fuzzy inference system (ANFIS) model prediction of R600a/MWCNT nanolubricant in a vapour compression system
- Babarinde, T O, Akinlabi, S A, Madyira, D M, Ekundayo, F M, Adedeji, P A
- Authors: Babarinde, T O , Akinlabi, S A , Madyira, D M , Ekundayo, F M , Adedeji, P A
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3248 , vital:43283 , https://doi.org/10.1016/j.dib.2020.106316
- Description: This research paper assessed the performance of R600a with the base lubricant and Multi-walled Carbon Nanotube (MWCNT) nanolubricant at steady state. It describes the instruments required for measurement of the data parameter and its uncertainties, steps involved in preparing and replacing the MWCNT nanolubricant concentration with base lubricant in vapour compression refrigeration. The system’s temperature data was collected at the components inlets and outlets. Pressure data was also registered at the compressor outlet and inlet. The data was captured at 27 °C ambient temperature at an interval of 30 min for 300 min. The experiment includes the experimental data collection, Adaptive Neuro-Fuzzy Inference System (ANFIS) training and testing dataset. The use of ANFIS model is explained in predicting the efficiency of MWCNT nanolubricant in a vapour compression refrigerator system. The ANFIS model also provides statistical output measures such as Root Mean Square Error (RMSE) and Mean Absolute Deviation (MAD), Mean Absolute Percentage Error (MAPE), and determination coefficient (R2). The data is useful and important for replacing MWCNT nanolubricant with base lubricant in a vapour compression refrigeration system for researchers in the specialisation of energy-efficient materials in refrigeration. The data present can be reused for vapour compression refrigeration systems simulation and modelling.
- Full Text:
- Date Issued: 2020
- Authors: Babarinde, T O , Akinlabi, S A , Madyira, D M , Ekundayo, F M , Adedeji, P A
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3248 , vital:43283 , https://doi.org/10.1016/j.dib.2020.106316
- Description: This research paper assessed the performance of R600a with the base lubricant and Multi-walled Carbon Nanotube (MWCNT) nanolubricant at steady state. It describes the instruments required for measurement of the data parameter and its uncertainties, steps involved in preparing and replacing the MWCNT nanolubricant concentration with base lubricant in vapour compression refrigeration. The system’s temperature data was collected at the components inlets and outlets. Pressure data was also registered at the compressor outlet and inlet. The data was captured at 27 °C ambient temperature at an interval of 30 min for 300 min. The experiment includes the experimental data collection, Adaptive Neuro-Fuzzy Inference System (ANFIS) training and testing dataset. The use of ANFIS model is explained in predicting the efficiency of MWCNT nanolubricant in a vapour compression refrigerator system. The ANFIS model also provides statistical output measures such as Root Mean Square Error (RMSE) and Mean Absolute Deviation (MAD), Mean Absolute Percentage Error (MAPE), and determination coefficient (R2). The data is useful and important for replacing MWCNT nanolubricant with base lubricant in a vapour compression refrigeration system for researchers in the specialisation of energy-efficient materials in refrigeration. The data present can be reused for vapour compression refrigeration systems simulation and modelling.
- Full Text:
- Date Issued: 2020
Development of manganese phthalocyanine decorated with silver nanoparticles nanocomposite for improved electrocatalytic oxidation of hydrazine:
- Mpeta, Lekhetho S, Sen, Pinar, Nyokong, Tebello
- Authors: Mpeta, Lekhetho S , Sen, Pinar , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148472 , vital:38742 , https://doi.org/10.1016/j.jelechem.2020.114173
- Description: In this study we report on the synthesis of tetrakis [4-(4-(5-chloro-1H-benzo [d]imidazol-2-yl) phenoxy phthalocyaninato] manganese (III) chloride (MnPc). The MnPc was first used to modify a glassy carbon electrode, followed by the growth of silver nanoparticles (AgNPs) onto the MnPc modified electrode to form MnPc-AgNPs modified electrode. The modified electrode was characterized using cydic voltammetry, chronoamperometry, scanning electrochemical microscopy and electrochemical impedance spectroscopy. The modified MnPc-AgNPs electrode was employed for the detection of hydrazine. The MnPc-AgNPs gave better current responses for electrooxidation of hydrazine relative to MnPc and AgNPs, individually. The catalytic rate constant was 1.90 x 10(5 )M(-1) S-1, with the detection limit (LoD) of 2.42 pM (using 3 sigma notation), and sensitivity of 61.56 mu A mM(-1), for MnPc-AgNPs. (C) 2020 Elsevier B.V. All rights reserved.
- Full Text:
- Date Issued: 2020
- Authors: Mpeta, Lekhetho S , Sen, Pinar , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148472 , vital:38742 , https://doi.org/10.1016/j.jelechem.2020.114173
- Description: In this study we report on the synthesis of tetrakis [4-(4-(5-chloro-1H-benzo [d]imidazol-2-yl) phenoxy phthalocyaninato] manganese (III) chloride (MnPc). The MnPc was first used to modify a glassy carbon electrode, followed by the growth of silver nanoparticles (AgNPs) onto the MnPc modified electrode to form MnPc-AgNPs modified electrode. The modified electrode was characterized using cydic voltammetry, chronoamperometry, scanning electrochemical microscopy and electrochemical impedance spectroscopy. The modified MnPc-AgNPs electrode was employed for the detection of hydrazine. The MnPc-AgNPs gave better current responses for electrooxidation of hydrazine relative to MnPc and AgNPs, individually. The catalytic rate constant was 1.90 x 10(5 )M(-1) S-1, with the detection limit (LoD) of 2.42 pM (using 3 sigma notation), and sensitivity of 61.56 mu A mM(-1), for MnPc-AgNPs. (C) 2020 Elsevier B.V. All rights reserved.
- Full Text:
- Date Issued: 2020
Dietary fatty acids of spiders reveal spatial and temporal variations in aquatic-terrestrial linkages
- Chari, Lenin D, Richoux, Nicole B, Moyo, Sydney, Villet, Martin H
- Authors: Chari, Lenin D , Richoux, Nicole B , Moyo, Sydney , Villet, Martin H
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441919 , vital:73935 , https://doi.org/10.1016/j.fooweb.2020.e00152
- Description: Stream and riparian food webs can be strongly linked by inputs of aquatic emergent insect prey to terrestrial predators. However, quantifying these linkages and understanding how they vary in time and space is challenging. We investigated the dynamic width of a riverine trophic subsidy zone by determining the relationship between perpendicular distance from a river and dietary contributions of aquatic insect prey to web-building spiders' diets. To assess this relationship, riparian web-building spiders at two river sites were sampled during four seasons and analysed for the fatty acids 16:0, 16:1ω7 and 20:5ω3, their total ω3-fatty acid content and their ω3:ω6 ratio to evaluate trophic subsidies reaching them from an adjacent river. River-derived fatty acids generally declined with increased distance from the river, indicating a diffusion of aquatically derived subsidies into the riparian zone. While the river was only 16 m wide at its broadest, river-derived trophic subsidies were detected up to four times that distance from the river edge. Spiders at a downstream section of the river, characterised by generally higher emergence rates of aquatic insects, contained higher proportions of aquatic indicator fatty acids compared with spiders located upstream, where emergence rates were lower. Similarly, proportions of aquatic indicator fatty acids in spiders were lowest during winter when aquatic insect emergence rates were lowest. The fatty acid 20:5ω3 (eicosapentaenoic acid; EPA) held the best promise as a biomarker of aquatic-derived tropic subsidies and could be developed as a useful tool for riparian research and management.
- Full Text:
- Date Issued: 2020
- Authors: Chari, Lenin D , Richoux, Nicole B , Moyo, Sydney , Villet, Martin H
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441919 , vital:73935 , https://doi.org/10.1016/j.fooweb.2020.e00152
- Description: Stream and riparian food webs can be strongly linked by inputs of aquatic emergent insect prey to terrestrial predators. However, quantifying these linkages and understanding how they vary in time and space is challenging. We investigated the dynamic width of a riverine trophic subsidy zone by determining the relationship between perpendicular distance from a river and dietary contributions of aquatic insect prey to web-building spiders' diets. To assess this relationship, riparian web-building spiders at two river sites were sampled during four seasons and analysed for the fatty acids 16:0, 16:1ω7 and 20:5ω3, their total ω3-fatty acid content and their ω3:ω6 ratio to evaluate trophic subsidies reaching them from an adjacent river. River-derived fatty acids generally declined with increased distance from the river, indicating a diffusion of aquatically derived subsidies into the riparian zone. While the river was only 16 m wide at its broadest, river-derived trophic subsidies were detected up to four times that distance from the river edge. Spiders at a downstream section of the river, characterised by generally higher emergence rates of aquatic insects, contained higher proportions of aquatic indicator fatty acids compared with spiders located upstream, where emergence rates were lower. Similarly, proportions of aquatic indicator fatty acids in spiders were lowest during winter when aquatic insect emergence rates were lowest. The fatty acid 20:5ω3 (eicosapentaenoic acid; EPA) held the best promise as a biomarker of aquatic-derived tropic subsidies and could be developed as a useful tool for riparian research and management.
- Full Text:
- Date Issued: 2020
Do spotted hyaenas outcompete the big cats in a small, enclosed system in South Africa?:
- Comley, Jessica, Joubert, Christoffel J, Mgqatsa, Nokubonga, Parker, Daniel M
- Authors: Comley, Jessica , Joubert, Christoffel J , Mgqatsa, Nokubonga , Parker, Daniel M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150099 , vital:38940 , doi:10.1111/jzo.12772
- Description: Carnivores are adapted to kill, meaning sympatric carnivores can have particularly aggressive and harmful competitive interactions. The co‐existence of multiple carnivores in an ecosystem could be restricted by their similarity in ecological niches (e.g. dietary overlap); however, high prey abundances could facilitate their co‐existence. Although the development of small, enclosed reserves (over 400 km2) in South Africa has reduced human–carnivore conflict, these systems may increase the likelihood of carnivore intra‐guild competition due to the clumping of competing carnivores into these restricted spaces. Using carnivore scat and kill site analyses, we determined the dietary preferences and overlap of sympatric large carnivores in a small, enclosed reserve, Selati Game Reserve (Selati).
- Full Text:
- Date Issued: 2020
- Authors: Comley, Jessica , Joubert, Christoffel J , Mgqatsa, Nokubonga , Parker, Daniel M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150099 , vital:38940 , doi:10.1111/jzo.12772
- Description: Carnivores are adapted to kill, meaning sympatric carnivores can have particularly aggressive and harmful competitive interactions. The co‐existence of multiple carnivores in an ecosystem could be restricted by their similarity in ecological niches (e.g. dietary overlap); however, high prey abundances could facilitate their co‐existence. Although the development of small, enclosed reserves (over 400 km2) in South Africa has reduced human–carnivore conflict, these systems may increase the likelihood of carnivore intra‐guild competition due to the clumping of competing carnivores into these restricted spaces. Using carnivore scat and kill site analyses, we determined the dietary preferences and overlap of sympatric large carnivores in a small, enclosed reserve, Selati Game Reserve (Selati).
- Full Text:
- Date Issued: 2020
Examining intraspecific multiple predator effects across shifting predator sex ratios:
- Cuthbert, Ross N, Dalu, Tatenda, Wasserman, Ryan J, Weyl, Olaf L F, Froneman, P William, Callaghan, Amanda, Dick, Jaimie T A
- Authors: Cuthbert, Ross N , Dalu, Tatenda , Wasserman, Ryan J , Weyl, Olaf L F , Froneman, P William , Callaghan, Amanda , Dick, Jaimie T A
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150119 , vital:38941 , https://doi.org/10.1016/j.baae.2020.03.002
- Description: Predator-predator interactions, or “multiple predator effects” (MPEs), are pervasive in the structuring of communities and complicate predictive quantifications of ecosystem dynamics. The nature of MPEs is also context-dependent, manifesting differently among species, prey densities and habitat structures. However, there has hitherto been a lack of consideration for the implications of intraspecific demographic variation within populations for the strength of MPEs. The present study extends MPE concepts to examine intraspecific interactions among male and female predators across differences in prey densities using a functional response approach. Focusing on a copepod-mosquito model predator-prey system, interaction strengths of different sex ratio pairs of Lovenula raynerae were quantified towards larval Culex pipiens complex prey, with observations compared to both additive and substitutive model predictions.
- Full Text:
- Date Issued: 2020
- Authors: Cuthbert, Ross N , Dalu, Tatenda , Wasserman, Ryan J , Weyl, Olaf L F , Froneman, P William , Callaghan, Amanda , Dick, Jaimie T A
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150119 , vital:38941 , https://doi.org/10.1016/j.baae.2020.03.002
- Description: Predator-predator interactions, or “multiple predator effects” (MPEs), are pervasive in the structuring of communities and complicate predictive quantifications of ecosystem dynamics. The nature of MPEs is also context-dependent, manifesting differently among species, prey densities and habitat structures. However, there has hitherto been a lack of consideration for the implications of intraspecific demographic variation within populations for the strength of MPEs. The present study extends MPE concepts to examine intraspecific interactions among male and female predators across differences in prey densities using a functional response approach. Focusing on a copepod-mosquito model predator-prey system, interaction strengths of different sex ratio pairs of Lovenula raynerae were quantified towards larval Culex pipiens complex prey, with observations compared to both additive and substitutive model predictions.
- Full Text:
- Date Issued: 2020
Fabrication of dye-sensitized solar cells based on push-pull asymmetrical substituted zinc and copper phthalocyanines and reduced graphene oxide nanosheet:
- Chindeka, Francis, Mashazi, Philani N, Britton, Jonathan, Oluwole, David O, Mapukata, Sivuyisiwe, Nyokong, Tebello
- Authors: Chindeka, Francis , Mashazi, Philani N , Britton, Jonathan , Oluwole, David O , Mapukata, Sivuyisiwe , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149076 , vital:38802 , https://doi.org/10.1016/j.jphotochem.2020.112612
- Description: Dye sensitized solar cells (DSSCs) were fabricated by using 2(3,5-biscarboxyphenoxy), 9(10), 16(17), 23(24)-tri(tertbutyl) phthalocyaninato Cu (4) and Zn (5) complexes as dyes on the ITO-TiO2 photoanodes containing reduced graphene oxide nanosheets (rGONS) or nitrogen-doped rGONS (NrGONS). The evaluation of the assembled DSSCs revealed that using ITO-TiO2-NrGONS-CuPc photoanode had the highest fill factor (FF) and power conversion efficiency (ɳ) of 69% and 4.36% respectively. These results show that the asymmetrical phthalocyanine complexes (4) and (5) exhibit significant improvement on the performance of the DSSC compared to our previous work on symmetrical carboxylated phthalocyanines with ɳ = 3.19%.
- Full Text:
- Date Issued: 2020
- Authors: Chindeka, Francis , Mashazi, Philani N , Britton, Jonathan , Oluwole, David O , Mapukata, Sivuyisiwe , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149076 , vital:38802 , https://doi.org/10.1016/j.jphotochem.2020.112612
- Description: Dye sensitized solar cells (DSSCs) were fabricated by using 2(3,5-biscarboxyphenoxy), 9(10), 16(17), 23(24)-tri(tertbutyl) phthalocyaninato Cu (4) and Zn (5) complexes as dyes on the ITO-TiO2 photoanodes containing reduced graphene oxide nanosheets (rGONS) or nitrogen-doped rGONS (NrGONS). The evaluation of the assembled DSSCs revealed that using ITO-TiO2-NrGONS-CuPc photoanode had the highest fill factor (FF) and power conversion efficiency (ɳ) of 69% and 4.36% respectively. These results show that the asymmetrical phthalocyanine complexes (4) and (5) exhibit significant improvement on the performance of the DSSC compared to our previous work on symmetrical carboxylated phthalocyanines with ɳ = 3.19%.
- Full Text:
- Date Issued: 2020
Lions do not change rivers: complex African savannas preclude top-down forcing by large carnivores
- Comley, Jessica, Joubert, Christoffel J, Mgqatsa, Nokubonga, Parker, Daniel M
- Authors: Comley, Jessica , Joubert, Christoffel J , Mgqatsa, Nokubonga , Parker, Daniel M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149215 , vital:38816 , https://doi.org/10.1016/j.jnc.2020.125844
- Description: Trophic cascade theories such as the ‘behaviourally-mediated trophic cascade hypothesis’ (BMTCH), have mainstreamed as ecological tools for conserving biodiversity and restoring ecosystems. The BMTCH relies on indirect negative effects of large carnivores through suppression of mesocarnivore activity and habitat use. Importantly, effects of top carnivores on mesocarnivores varies over time and space, is dependent on the species involved, and local context. In South Africa, there are very few free-ranging carnivores, as populations are often restricted to enclosed reserves. While predator-proof fences reduce human-wildlife conflict, they also influence space use within communities. We used an enclosed reserve with a relatively full complement of carnivores to test the generality of the BMTCH in the African context. Using single-species, multi-season occupancy models we investigated the spatial dynamics of multiple carnivores. We also investigated spatial partitioning by vegetation type and temporal partitioning.
- Full Text:
- Date Issued: 2020
- Authors: Comley, Jessica , Joubert, Christoffel J , Mgqatsa, Nokubonga , Parker, Daniel M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149215 , vital:38816 , https://doi.org/10.1016/j.jnc.2020.125844
- Description: Trophic cascade theories such as the ‘behaviourally-mediated trophic cascade hypothesis’ (BMTCH), have mainstreamed as ecological tools for conserving biodiversity and restoring ecosystems. The BMTCH relies on indirect negative effects of large carnivores through suppression of mesocarnivore activity and habitat use. Importantly, effects of top carnivores on mesocarnivores varies over time and space, is dependent on the species involved, and local context. In South Africa, there are very few free-ranging carnivores, as populations are often restricted to enclosed reserves. While predator-proof fences reduce human-wildlife conflict, they also influence space use within communities. We used an enclosed reserve with a relatively full complement of carnivores to test the generality of the BMTCH in the African context. Using single-species, multi-season occupancy models we investigated the spatial dynamics of multiple carnivores. We also investigated spatial partitioning by vegetation type and temporal partitioning.
- Full Text:
- Date Issued: 2020
Movement patterns of the epizoic limpet Lottia tenuisculpta on two host snails Omphalius nigerrimus and Reishia clavigera:
- Nakano, Tomoyuki, Okumura, Yousuke, Nakayama, Ryo, Seuront, Laurent
- Authors: Nakano, Tomoyuki , Okumura, Yousuke , Nakayama, Ryo , Seuront, Laurent
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160268 , vital:40429 , DOI: 10.1080/13235818.2020.1808280
- Description: The tiny epizoic limpet Lottia tenuisculpta lives on rocky surfaces and shells of the snails Omphalius nigerrimus and Reishia clavigera. The movement patterns of the limpet on host snails was observed during 24 h under controlled laboratory conditions. A specific behaviour, referred to as returning behaviour and reminiscent of homing behaviour, was observed in seven out of 20 individuals, and two out of 15 individuals on O. nigerrimus and R. clavigera, respectively.
- Full Text:
- Date Issued: 2020
- Authors: Nakano, Tomoyuki , Okumura, Yousuke , Nakayama, Ryo , Seuront, Laurent
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160268 , vital:40429 , DOI: 10.1080/13235818.2020.1808280
- Description: The tiny epizoic limpet Lottia tenuisculpta lives on rocky surfaces and shells of the snails Omphalius nigerrimus and Reishia clavigera. The movement patterns of the limpet on host snails was observed during 24 h under controlled laboratory conditions. A specific behaviour, referred to as returning behaviour and reminiscent of homing behaviour, was observed in seven out of 20 individuals, and two out of 15 individuals on O. nigerrimus and R. clavigera, respectively.
- Full Text:
- Date Issued: 2020
Non-material costs of wildlife conservation to local people and their implications for conservation interventions:
- Thondhlana, Gladman, Redpath, Stephen Mark, Vedeld, Pål Olav, Van Eeden, Lily, Pascual, Unai, Sherren, Kate, Murata, Chenai
- Authors: Thondhlana, Gladman , Redpath, Stephen Mark , Vedeld, Pål Olav , Van Eeden, 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 Eeden, 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
Nuruddin Farah: variations on the theme of return
- Authors: Naicker, Kamil
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149643 , vital:38871 , https://www.ajol.info/index.php/tvl/article/view/196356
- Description: This article explores the role of the returnee protagonist in selected works of Nuruddin Farah. Nadine Gordimer described Farah as “one of the real interpreters” of Africa and this article argues that Farah’s returnees operate as interpreters themselves, their liminality working to mediate between international readers and “local” subject matter. However, it also observes that Farah, who spent decades in exile, is often as preoccupied with writing non-belonging as he is with rendering Somalia itself. Farah’s returnee narratives are, broadly, novels of redress, in which characters enact their return in an attempt to seek out the missing, rebuild the lost or reclaim the stolen, with imperfect results. In exploring these variations on homecoming, the paper investigates the ways in which Farah’s body of work reflects shifts in identity politics over time, and the unique pressures these shifts exert on the homecoming arc.
- Full Text:
- Date Issued: 2020
- Authors: Naicker, Kamil
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149643 , vital:38871 , https://www.ajol.info/index.php/tvl/article/view/196356
- Description: This article explores the role of the returnee protagonist in selected works of Nuruddin Farah. Nadine Gordimer described Farah as “one of the real interpreters” of Africa and this article argues that Farah’s returnees operate as interpreters themselves, their liminality working to mediate between international readers and “local” subject matter. However, it also observes that Farah, who spent decades in exile, is often as preoccupied with writing non-belonging as he is with rendering Somalia itself. Farah’s returnee narratives are, broadly, novels of redress, in which characters enact their return in an attempt to seek out the missing, rebuild the lost or reclaim the stolen, with imperfect results. In exploring these variations on homecoming, the paper investigates the ways in which Farah’s body of work reflects shifts in identity politics over time, and the unique pressures these shifts exert on the homecoming arc.
- Full Text:
- Date Issued: 2020
Patient acceptance of HIV testing services in rural emergency departments in South Africa
- Aditi Rao, Caitlin Kennedy, Pamela Mda, Thomas C. Quinn, David Stead, Bhakti Hansoti
- Authors: Aditi Rao , Caitlin Kennedy , Pamela Mda , Thomas C. Quinn , David Stead , Bhakti Hansoti
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3270 , vital:43287 , https://doi.org/10.4102/sajhivmed.v21i1.1105
- Description: Background: South Africa faces the highest burden of HIV infection globally. The National Strategic Plan on HIV recommends provider-initiated HIV counselling and testing (HCT) in all healthcare facilities. However, HIV continues to overwhelm the healthcare system. Emergency department (ED)-based HCT could address unmet testing needs. Objectives: This study examines the reasons for accepting or declining HCT in South African EDs to inform the development of HCT implementation strategies. Method: We conducted a prospective observational study in two rural EDs, from June to September 2017. Patients presenting to the ED were systematically approached and offered a point-of-care test in accordance with national guidelines. Patients demographics, presenting compaint, medical history and reasons for accepting/declining testing, were recorded. A pooled analysis is presented. Results: Across sites, 2074 adult, non-critical patients in the ED were approached; 1880 were enrolled in the study. Of those enrolled, 19.7% had a previously known positive diagnosis, and 80.3% were unaware of their HIV status. Of those unaware, 90% patients accepted and 10% declined testing. The primary reasons for declining testing were ‘does not want to know status’ (37.6%), ‘in too much pain’ (34%) and ‘does not believe they are at risk’ (19.9%). Conclusions: Despite national guidelines, a high proportion of individuals remain undiagnosed, of which a majority are young men. Our study demonstrated high patient acceptance of ED-based HCT. There is a need for investment and innovation regarding effective pain management and confidential service delivery to address patient barriers. Findings support a routine, non-targeted HCT strategy in EDs. Keywords: HIV counselling and testing; South Africa; emergency department; patient acceptance; implementation research; linkage to care.
- Full Text:
- Date Issued: 2020
- Authors: Aditi Rao , Caitlin Kennedy , Pamela Mda , Thomas C. Quinn , David Stead , Bhakti Hansoti
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3270 , vital:43287 , https://doi.org/10.4102/sajhivmed.v21i1.1105
- Description: Background: South Africa faces the highest burden of HIV infection globally. The National Strategic Plan on HIV recommends provider-initiated HIV counselling and testing (HCT) in all healthcare facilities. However, HIV continues to overwhelm the healthcare system. Emergency department (ED)-based HCT could address unmet testing needs. Objectives: This study examines the reasons for accepting or declining HCT in South African EDs to inform the development of HCT implementation strategies. Method: We conducted a prospective observational study in two rural EDs, from June to September 2017. Patients presenting to the ED were systematically approached and offered a point-of-care test in accordance with national guidelines. Patients demographics, presenting compaint, medical history and reasons for accepting/declining testing, were recorded. A pooled analysis is presented. Results: Across sites, 2074 adult, non-critical patients in the ED were approached; 1880 were enrolled in the study. Of those enrolled, 19.7% had a previously known positive diagnosis, and 80.3% were unaware of their HIV status. Of those unaware, 90% patients accepted and 10% declined testing. The primary reasons for declining testing were ‘does not want to know status’ (37.6%), ‘in too much pain’ (34%) and ‘does not believe they are at risk’ (19.9%). Conclusions: Despite national guidelines, a high proportion of individuals remain undiagnosed, of which a majority are young men. Our study demonstrated high patient acceptance of ED-based HCT. There is a need for investment and innovation regarding effective pain management and confidential service delivery to address patient barriers. Findings support a routine, non-targeted HCT strategy in EDs. Keywords: HIV counselling and testing; South Africa; emergency department; patient acceptance; implementation research; linkage to care.
- Full Text:
- Date Issued: 2020
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
Quantifying the impacts of abrasion and bacterial transfer when fish are exposed to sand during a catch-and-release event:
- Foster, Ryan M, Childs, Amber-Robyn, Brooks, Margot, Farthing, Matthew W, Butler, Edward C, Potts, Warren M
- Authors: Foster, Ryan M , Childs, Amber-Robyn , Brooks, Margot , Farthing, Matthew W , Butler, Edward C , Potts, Warren M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160427 , vital:40445 , https://doi.org/10.2989/1814232X.2020.1792982
- Description: Best-practice guidelines to improve recreational fishers’ handling during catch-and-release (CandR) events are critical to improve the conservation and management of fish stocks worldwide. While best-practice research is growing, there are knowledge gaps, with the effects of sand exposure on fish mucous membranes understudied. This study aimed to determine the effects of exposing a fish to sand during a CandR event. A total of 360 juvenile (48–137 mm TL) Cape stumpnose Rhabdosargus holubi were subjected to a simulated CandR event during which they were either held: (i) with wet hands, or (ii) dry hands; or with wet hands and then placed on either (iii) wet sterilised sand, (iv) dry sterilised sand, (v) wet unsterilised sand, or (vi) dry unsterilised sand. Fish were maintained in a recirculating system for two weeks, euthanised and subjected to an examination of their mucous layer (bacterial counts, abrasion counts and percentage of abrasion area) and an internal biological assessment. Bacteria fro m fish mucous layers were cultivated on agar plates to count bacterial colonies.
- Full Text:
- Date Issued: 2020
- Authors: Foster, Ryan M , Childs, Amber-Robyn , Brooks, Margot , Farthing, Matthew W , Butler, Edward C , Potts, Warren M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160427 , vital:40445 , https://doi.org/10.2989/1814232X.2020.1792982
- Description: Best-practice guidelines to improve recreational fishers’ handling during catch-and-release (CandR) events are critical to improve the conservation and management of fish stocks worldwide. While best-practice research is growing, there are knowledge gaps, with the effects of sand exposure on fish mucous membranes understudied. This study aimed to determine the effects of exposing a fish to sand during a CandR event. A total of 360 juvenile (48–137 mm TL) Cape stumpnose Rhabdosargus holubi were subjected to a simulated CandR event during which they were either held: (i) with wet hands, or (ii) dry hands; or with wet hands and then placed on either (iii) wet sterilised sand, (iv) dry sterilised sand, (v) wet unsterilised sand, or (vi) dry unsterilised sand. Fish were maintained in a recirculating system for two weeks, euthanised and subjected to an examination of their mucous layer (bacterial counts, abrasion counts and percentage of abrasion area) and an internal biological assessment. Bacteria fro m fish mucous layers were cultivated on agar plates to count bacterial colonies.
- Full Text:
- Date Issued: 2020
Social capital reduces vulnerability in rural coastal communities of Solomon Islands:
- Malherbe, Willem, Sauer, Warwick H H, Aswani, Shankar
- Authors: Malherbe, Willem , Sauer, Warwick H H , Aswani, Shankar
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150230 , vital:38951 , https://doi.org/10.1016/j.ocecoaman.2020.105186
- Description: Rural island communities are generally regarded as the most vulnerable groups affected by climate change. This perception arises due to them often being in less developed areas with high levels of exposure to stressors, while reportedly lacking the means to cope with these stressors. Studies which use developed-country yardsticks, such as those used in past IPCC-based assessments, when measuring vulnerability in less developed states will however inevitably over-pronounce its effects in such areas. The sustainable livelihoods approach provides an alternate means of determining vulnerability using capital assets such as social capital. The presence of these assets enables communities to pursue diverse livelihood strategies which ultimately serve to reduce their vulnerability. This study seeks to measure attributes of social capital in five marine dependent communities of Solomon Islands.
- Full Text:
- Date Issued: 2020
- Authors: Malherbe, Willem , Sauer, Warwick H H , Aswani, Shankar
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150230 , vital:38951 , https://doi.org/10.1016/j.ocecoaman.2020.105186
- Description: Rural island communities are generally regarded as the most vulnerable groups affected by climate change. This perception arises due to them often being in less developed areas with high levels of exposure to stressors, while reportedly lacking the means to cope with these stressors. Studies which use developed-country yardsticks, such as those used in past IPCC-based assessments, when measuring vulnerability in less developed states will however inevitably over-pronounce its effects in such areas. The sustainable livelihoods approach provides an alternate means of determining vulnerability using capital assets such as social capital. The presence of these assets enables communities to pursue diverse livelihood strategies which ultimately serve to reduce their vulnerability. This study seeks to measure attributes of social capital in five marine dependent communities of Solomon Islands.
- Full Text:
- Date Issued: 2020