Enhanced photodynamic antimicrobial activity of surface modified SiNPs doped with zinc (II) phthalocyanines: the effect of antimicrobial ampicillin and extra charges from a sultone
- Magadla, Aviwe, Nyokong, Tebello
- Authors: Magadla, Aviwe , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160511 , vital:40452 , https://doi.org/10.1016/j.pdpdt.2020.101996
- Description: 1-(2-Methoxyethyl)piperidine sustituted Zn phthalocyanine complex (2) is synthesised and quartenised (3). These complexes are loaded into silica nanoparticles (SiNPs) that are futher surface modified with ampicillin and 1.3-propanesultone. The photophysical and photochemical properties of the complexes and their doped conjugates were investigated in dimethylsulfoxide. The cationic complex (3) is used for photodynamic antimicrobial activity. Log reduction values of above 9 are obtained towards the photoiactivation of Staphyloccocus aureus.
- Full Text:
- Date Issued: 2020
- Authors: Magadla, Aviwe , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160511 , vital:40452 , https://doi.org/10.1016/j.pdpdt.2020.101996
- Description: 1-(2-Methoxyethyl)piperidine sustituted Zn phthalocyanine complex (2) is synthesised and quartenised (3). These complexes are loaded into silica nanoparticles (SiNPs) that are futher surface modified with ampicillin and 1.3-propanesultone. The photophysical and photochemical properties of the complexes and their doped conjugates were investigated in dimethylsulfoxide. The cationic complex (3) is used for photodynamic antimicrobial activity. Log reduction values of above 9 are obtained towards the photoiactivation of Staphyloccocus aureus.
- Full Text:
- Date Issued: 2020
Implementing prolonged exposure therapy for PTSD in a context of ongoing adversity: a clinical case study
- Booysen, Duane D, Kagee, Ashraf
- Authors: Booysen, Duane D , Kagee, Ashraf
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149275 , vital:38821 , https://0-doi.org.wam.seals.ac.za/10.1177/1534650120925918
- Description: Obstacles regarding the implementation of empirically supported treatments (ESTs) for mental disorders such as post-traumatic stress disorder (PTSD) still require further investigation. One notable obstacle is whether persons in low- and middle-income countries (LMICs) residing in a context of ongoing adversity would benefit from an EST for PTSD. We reflect on the utility of a brief prolonged exposure intervention at a primary care community-counseling center in South Africa. “Sam,” a 45-year-old, female was assessed at baseline, during treatment, postassessment, and at 3-month follow-up. At the beginning of treatment, Sam had a positive diagnosis for PTSD (PSSI-5 = 55, and cutoff is 23) and at the end of treatment (PSSI-5 = 17), and 3-month follow-up (PSSI-5 = 21), she had a negative diagnosis for PTSD. We reflect on the mediating effects that contextual factors such as gang violence had on the treatment process and the feasibility of implementing ESTs for PTSD in LMICs under conditions of ongoing adversity.
- Full Text:
- Date Issued: 2020
- Authors: Booysen, Duane D , Kagee, Ashraf
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149275 , vital:38821 , https://0-doi.org.wam.seals.ac.za/10.1177/1534650120925918
- Description: Obstacles regarding the implementation of empirically supported treatments (ESTs) for mental disorders such as post-traumatic stress disorder (PTSD) still require further investigation. One notable obstacle is whether persons in low- and middle-income countries (LMICs) residing in a context of ongoing adversity would benefit from an EST for PTSD. We reflect on the utility of a brief prolonged exposure intervention at a primary care community-counseling center in South Africa. “Sam,” a 45-year-old, female was assessed at baseline, during treatment, postassessment, and at 3-month follow-up. At the beginning of treatment, Sam had a positive diagnosis for PTSD (PSSI-5 = 55, and cutoff is 23) and at the end of treatment (PSSI-5 = 17), and 3-month follow-up (PSSI-5 = 21), she had a negative diagnosis for PTSD. We reflect on the mediating effects that contextual factors such as gang violence had on the treatment process and the feasibility of implementing ESTs for PTSD in LMICs under conditions of ongoing adversity.
- Full Text:
- Date Issued: 2020
Integrative taxonomy reveals hidden diversity in the southern African darters genus Nannocharax Günther 1867 (Characiformes: Distichodontidae):
- Bragança, Pedro H N, Smith, Timothy G, Vreven, Emmanuel J W M N, Chakona, Albert
- Authors: Bragança, Pedro H N , Smith, Timothy G , Vreven, Emmanuel J W M N , Chakona, Albert
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163510 , vital:41044 , https://0-doi.org.wam.seals.ac.za/10.1111/jfb.14535
- Description: The present study explored the diversity of Nannocharax within southern Africa by implementing three species delimitation methods for a data set consisting of 37 mitochondrial cytochrome oxidase subunit I sequences. Two unilocus coalescent methods, the General Mixed Yule Coalescent (GMYC) and the Bayesian implementation of the Poisson Tree Processes (bPTP), and a genetic distance method, the Automatic Barcode Gap Discovery (ABGD), were applied. Both GMYC and bPTP delimited the same operational taxonomic units (OTUs), revealing a higher diversity for the genus in the region than previously recognised, whereas the ABGD failed to delimit the same candidate species.
- Full Text:
- Date Issued: 2020
- Authors: Bragança, Pedro H N , Smith, Timothy G , Vreven, Emmanuel J W M N , Chakona, Albert
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163510 , vital:41044 , https://0-doi.org.wam.seals.ac.za/10.1111/jfb.14535
- Description: The present study explored the diversity of Nannocharax within southern Africa by implementing three species delimitation methods for a data set consisting of 37 mitochondrial cytochrome oxidase subunit I sequences. Two unilocus coalescent methods, the General Mixed Yule Coalescent (GMYC) and the Bayesian implementation of the Poisson Tree Processes (bPTP), and a genetic distance method, the Automatic Barcode Gap Discovery (ABGD), were applied. Both GMYC and bPTP delimited the same operational taxonomic units (OTUs), revealing a higher diversity for the genus in the region than previously recognised, whereas the ABGD failed to delimit the same candidate species.
- Full Text:
- Date Issued: 2020
Integrative taxonomy reveals hidden diversity in the southern African darters genus Nannocharax Günther 1867 (Characiformes: Distichodontidae):
- Bragança, Pedro H N, Smith, Timothy G, Vreven, Emmanuel J W M N, Chakona, Albert
- Authors: Bragança, Pedro H N , Smith, Timothy G , Vreven, Emmanuel J W M N , Chakona, Albert
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163543 , vital:41047 , https://0-doi.org.wam.seals.ac.za/10.1111/jfb.14535
- Description: The present study explored the diversity of Nannocharax within southern Africa by implementing three species delimitation methods for a data set consisting of 37 mitochondrial cytochrome oxidase subunit I sequences. Two unilocus coalescent methods, the General Mixed Yule Coalescent (GMYC) and the Bayesian implementation of the Poisson Tree Processes (bPTP), and a genetic distance method, the Automatic Barcode Gap Discovery (ABGD), were applied. Both GMYC and bPTP delimited the same operational taxonomic units (OTUs), revealing a higher diversity for the genus in the region than previously recognised, whereas the ABGD failed to delimit the same candidate species.
- Full Text:
- Date Issued: 2020
- Authors: Bragança, Pedro H N , Smith, Timothy G , Vreven, Emmanuel J W M N , Chakona, Albert
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163543 , vital:41047 , https://0-doi.org.wam.seals.ac.za/10.1111/jfb.14535
- Description: The present study explored the diversity of Nannocharax within southern Africa by implementing three species delimitation methods for a data set consisting of 37 mitochondrial cytochrome oxidase subunit I sequences. Two unilocus coalescent methods, the General Mixed Yule Coalescent (GMYC) and the Bayesian implementation of the Poisson Tree Processes (bPTP), and a genetic distance method, the Automatic Barcode Gap Discovery (ABGD), were applied. Both GMYC and bPTP delimited the same operational taxonomic units (OTUs), revealing a higher diversity for the genus in the region than previously recognised, whereas the ABGD failed to delimit the same candidate species.
- Full Text:
- Date Issued: 2020
Intermediate disturbance promotes diversity and the conservation of dung beetles (Scarabaeoidea: Scarabaeidae and Aphodiidae) in the Eastern Cape, South Africa
- Tocco, Claudia, Midgley, John M, Villet, Martin H
- Authors: Tocco, Claudia , Midgley, John M , Villet, Martin H
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442195 , vital:73966 , https://doi.org/10.1016/j.baae.2020.10.005
- Description: Environmental fluctuations, such as changes in climate, agricultural management and anthropogenic land-use patterns can affect the diversity of organisms inhabiting an area. Losses of biodiversity alter ecosystems processes, eroding their capacity to deliver ecosystem services. Dung beetles are critical ecosystem service providers, making them an ideal ecological indicator to explore the effects of land-use change on biodiversity. Dung beetles were sampled across three land-use types, in the summers of 2015 and 2016 in the Eastern Cape province, South Africa. Game ranching is regarded as a relatively low-intensity land use type. It was compared with cattle ranching (medium intensity) and dairy farming (high intensity) to examine their effect on dung beetle assemblage metrics (abundance, species richness and true Shannon diversity index), guild diversity (as nesting guilds) and spatial turnover. The intermediate grazing intensity of cattle ranching supported a higher abundance and diversity of both whole dung beetle assemblage and the nesting guilds, followed by the game ranches and then dairy farms. Differences between the sampling years were dependent on the beetle nesting guild, and largely correlated with rainfall and temperature. Cattle and game ranches shared a higher number of species than either shared with dairy farms. Whittaker's Beta-diversity index showed the highest species turnover between game ranches and dairy farms. A mix of game and cattle ranching, minimising dairy farming or restricting it to already ecological degraded sites, appears the best alternative for maintenance of dung beetle diversity and their ecosystem services. The year-to-year trends of the data were in general consistent, confirming that dung beetles are reliable ecological indicators; but also suggest that climate change that affects rainfall will result in the reduction of the abundance and diversity of this key ecological group.
- Full Text:
- Date Issued: 2020
- Authors: Tocco, Claudia , Midgley, John M , Villet, Martin H
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442195 , vital:73966 , https://doi.org/10.1016/j.baae.2020.10.005
- Description: Environmental fluctuations, such as changes in climate, agricultural management and anthropogenic land-use patterns can affect the diversity of organisms inhabiting an area. Losses of biodiversity alter ecosystems processes, eroding their capacity to deliver ecosystem services. Dung beetles are critical ecosystem service providers, making them an ideal ecological indicator to explore the effects of land-use change on biodiversity. Dung beetles were sampled across three land-use types, in the summers of 2015 and 2016 in the Eastern Cape province, South Africa. Game ranching is regarded as a relatively low-intensity land use type. It was compared with cattle ranching (medium intensity) and dairy farming (high intensity) to examine their effect on dung beetle assemblage metrics (abundance, species richness and true Shannon diversity index), guild diversity (as nesting guilds) and spatial turnover. The intermediate grazing intensity of cattle ranching supported a higher abundance and diversity of both whole dung beetle assemblage and the nesting guilds, followed by the game ranches and then dairy farms. Differences between the sampling years were dependent on the beetle nesting guild, and largely correlated with rainfall and temperature. Cattle and game ranches shared a higher number of species than either shared with dairy farms. Whittaker's Beta-diversity index showed the highest species turnover between game ranches and dairy farms. A mix of game and cattle ranching, minimising dairy farming or restricting it to already ecological degraded sites, appears the best alternative for maintenance of dung beetle diversity and their ecosystem services. The year-to-year trends of the data were in general consistent, confirming that dung beetles are reliable ecological indicators; but also suggest that climate change that affects rainfall will result in the reduction of the abundance and diversity of this key ecological group.
- Full Text:
- Date Issued: 2020
Misconceptions and misapplications of student-centered approaches
- Authors: McKenna, Sioux , Quinn, Lynn
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/453507 , vital:75259 , ISBN 9780429259371 , https://www.taylorfrancis.com/chapters/edit/10.4324/9780429259371-8/misconceptions-misapplications-student-centered-approaches-sioux-mckenna-lynn-quinn
- Description: A 1967 cartoon strip by Bud Blake shows a young boy, Tiger, telling his friend that he has taught his dog, Stripe, to whistle. “I don’t hear him whistling,” says the friend. Tiger explains “I said I taught him. I didn’t say he learned it.” Understanding education in terms of what it is that teachers do at the expense of a focus on how students learn has long been criticized. In 1916, Dewey was calling for more democratic approaches to education which took the student’s context into account. In 1968, Freire called for a major shift away from the “banking model” of education to one that recognized the student’s role in co-constructing knowledge. Despite the long history of such calls, transmission modes of teaching endure. It is thus unsurprising that calls for student-centered learning (SCL) are widespread.
- Full Text:
- Date Issued: 2020
- Authors: McKenna, Sioux , Quinn, Lynn
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/453507 , vital:75259 , ISBN 9780429259371 , https://www.taylorfrancis.com/chapters/edit/10.4324/9780429259371-8/misconceptions-misapplications-student-centered-approaches-sioux-mckenna-lynn-quinn
- Description: A 1967 cartoon strip by Bud Blake shows a young boy, Tiger, telling his friend that he has taught his dog, Stripe, to whistle. “I don’t hear him whistling,” says the friend. Tiger explains “I said I taught him. I didn’t say he learned it.” Understanding education in terms of what it is that teachers do at the expense of a focus on how students learn has long been criticized. In 1916, Dewey was calling for more democratic approaches to education which took the student’s context into account. In 1968, Freire called for a major shift away from the “banking model” of education to one that recognized the student’s role in co-constructing knowledge. Despite the long history of such calls, transmission modes of teaching endure. It is thus unsurprising that calls for student-centered learning (SCL) are widespread.
- Full Text:
- Date Issued: 2020
New insights into the taxonomic status, distribution and natural history of De Witte's Clicking Frog (Kassinula wittei Laurent, 1940)
- Conradie, Werner C, Keates, Chad, Lobón-Rovira, Javier, Vaz Pinto, Pedro, Verburgt, Luke, Baptista, Ninda L, Harvey, James, Júlio, Timóteo
- Authors: Conradie, Werner C , Keates, Chad , Lobón-Rovira, Javier , Vaz Pinto, Pedro , Verburgt, Luke , Baptista, Ninda L , Harvey, James , Júlio, Timóteo
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443572 , vital:74134 , https://hdl.handle.net/10520/ejc-afzoo-v55-n4-a6
- Description: Kassinula is a monotypic genus of small frog in the family Hyperoliidae, only represented by Kassinula wittei. This species morphologically resembles both Kassina Girard, 1853 and Afrixalus Laurent, 1944, and its taxonomic status has been debated for decades. It has previously been subsumed within Kassina, and is currently placed as a sister genus to Afrixalus, although it has not been included in any phylogenetic studies until now. This species is poorly represented in museum collections and is only known from fewer than 35 specimens from southern Democratic Republic of the Congo and adjacent Zambia. Newly collected material from central Angola, a range extension of 400-800 km west of previously known localities, allowed us to revisit the taxonomic placement of the genus with the aid of phylogenetic analysis and shed light on its geographic distribution, morphology and natural history. Although our phylogenetic analysis is limited to a single mitochondrial gene (16S), we place Kassinula in the subfamily Hyperoliinae and closely related to Afrixalus, with a high degree of confidence. Further phylogenetic studies are needed before formally synonymising Afrixalus with Kassinula.
- Full Text:
- Date Issued: 2020
- Authors: Conradie, Werner C , Keates, Chad , Lobón-Rovira, Javier , Vaz Pinto, Pedro , Verburgt, Luke , Baptista, Ninda L , Harvey, James , Júlio, Timóteo
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443572 , vital:74134 , https://hdl.handle.net/10520/ejc-afzoo-v55-n4-a6
- Description: Kassinula is a monotypic genus of small frog in the family Hyperoliidae, only represented by Kassinula wittei. This species morphologically resembles both Kassina Girard, 1853 and Afrixalus Laurent, 1944, and its taxonomic status has been debated for decades. It has previously been subsumed within Kassina, and is currently placed as a sister genus to Afrixalus, although it has not been included in any phylogenetic studies until now. This species is poorly represented in museum collections and is only known from fewer than 35 specimens from southern Democratic Republic of the Congo and adjacent Zambia. Newly collected material from central Angola, a range extension of 400-800 km west of previously known localities, allowed us to revisit the taxonomic placement of the genus with the aid of phylogenetic analysis and shed light on its geographic distribution, morphology and natural history. Although our phylogenetic analysis is limited to a single mitochondrial gene (16S), we place Kassinula in the subfamily Hyperoliinae and closely related to Afrixalus, with a high degree of confidence. Further phylogenetic studies are needed before formally synonymising Afrixalus with Kassinula.
- Full Text:
- Date Issued: 2020
Photodynamic antimicrobial chemotherapy of a dimethylamino-functionalized asymmetric zinc (II) phthalocyanine and its quaternized derivative against Staphylococcus aureus when supported on asymmetric polystyrene polymer membranes:
- Mafukidze, Donovan Musizvinoda Chidyamurimi, Nyokong, Tebello
- Authors: Mafukidze, Donovan Musizvinoda Chidyamurimi , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148595 , vital:38753 , https://doi.org/10.1016/j.reactfunctpolym.2020.104634
- Description: Membrane applications are hindered by fouling. Photoactive membranes (containing photosensitizers) show photodynamic antimicrobial chemotherapy (PACT) activity which reduces biological fouling. In this work we use phthalocyanines (Pcs) as photosensitizers. The Pcs used are: 2-(4-carboxyphenoxy)-9(10), 16(17), 23(24)-tris(dimethylamino) phthalocyaninato zinc(II) (1) and the quaternized 2-(4-carboxyphenoxy)-9(10), 16(17), 23(24)-tris(trimethylamino) phthalocyanine zinc(II) methyl sulfate (2). Complex 2 showed an enhanced singlet oxygen quantum yield (ΦΔ) of 0.76 compared to 0.53 for 1. Complex 2 showed enhanced PACT activity against Staphylococcus aureus giving a log reduction value of 9.4, while its precursor (complex 1) gave 0.08. The complexes were then conjugated to amine-functionalized polystyrene and embedded into polystyrene to form membranes resulting in ΦΔ values of 0.24 and 0.27 for complexes 1 and 2 respectively in water. The latter membrane showed better PACT activity.
- Full Text:
- Date Issued: 2020
- Authors: Mafukidze, Donovan Musizvinoda Chidyamurimi , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148595 , vital:38753 , https://doi.org/10.1016/j.reactfunctpolym.2020.104634
- Description: Membrane applications are hindered by fouling. Photoactive membranes (containing photosensitizers) show photodynamic antimicrobial chemotherapy (PACT) activity which reduces biological fouling. In this work we use phthalocyanines (Pcs) as photosensitizers. The Pcs used are: 2-(4-carboxyphenoxy)-9(10), 16(17), 23(24)-tris(dimethylamino) phthalocyaninato zinc(II) (1) and the quaternized 2-(4-carboxyphenoxy)-9(10), 16(17), 23(24)-tris(trimethylamino) phthalocyanine zinc(II) methyl sulfate (2). Complex 2 showed an enhanced singlet oxygen quantum yield (ΦΔ) of 0.76 compared to 0.53 for 1. Complex 2 showed enhanced PACT activity against Staphylococcus aureus giving a log reduction value of 9.4, while its precursor (complex 1) gave 0.08. The complexes were then conjugated to amine-functionalized polystyrene and embedded into polystyrene to form membranes resulting in ΦΔ values of 0.24 and 0.27 for complexes 1 and 2 respectively in water. The latter membrane showed better PACT activity.
- Full Text:
- Date Issued: 2020
Regularly drinking desert birds have greater evaporative cooling capacity and higher heat tolerance limits than non‐drinking species
- Czenze, Zenon J, Kemp, Ryno, van Jaarsveld, Barry, Freeman, Marc T, Smit, Ben, Wolf, Blair O, McKechnie, Andrew
- Authors: Czenze, Zenon J , Kemp, Ryno , van Jaarsveld, Barry , Freeman, Marc T , Smit, Ben , Wolf, Blair O , McKechnie, Andrew
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441585 , vital:73900 , https://doi.org/10.1111/1365-2435.13573
- Description: Surface water is a critical resource for many birds inhabiting arid re-gions, but the implications of regular drinking and dependence on sur-face water for the evolution of thermal physiology remain largely unex-plored. We hypothesized that avian thermoregulation in the heat has evolved in tandem with the use of surface water and predicted that (a) regularly drinking species have a greater capacity to elevate rates of evaporative water loss (EWL) compared to non‐drinking species, and (b) heat tolerance limits (HTLs) are higher among drinking species. To test these predictions, we quantified thermoregulatory responses to high air temperature (Ta) in 12 species of passerines from the South African arid zone and combined these with values for an additional five species. We categorized each species as either: (a) water‐dependent, regularly drinking, or (b) water‐independent, occasional‐/non‐drinking.
- Full Text:
- Date Issued: 2020
- Authors: Czenze, Zenon J , Kemp, Ryno , van Jaarsveld, Barry , Freeman, Marc T , Smit, Ben , Wolf, Blair O , McKechnie, Andrew
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441585 , vital:73900 , https://doi.org/10.1111/1365-2435.13573
- Description: Surface water is a critical resource for many birds inhabiting arid re-gions, but the implications of regular drinking and dependence on sur-face water for the evolution of thermal physiology remain largely unex-plored. We hypothesized that avian thermoregulation in the heat has evolved in tandem with the use of surface water and predicted that (a) regularly drinking species have a greater capacity to elevate rates of evaporative water loss (EWL) compared to non‐drinking species, and (b) heat tolerance limits (HTLs) are higher among drinking species. To test these predictions, we quantified thermoregulatory responses to high air temperature (Ta) in 12 species of passerines from the South African arid zone and combined these with values for an additional five species. We categorized each species as either: (a) water‐dependent, regularly drinking, or (b) water‐independent, occasional‐/non‐drinking.
- Full Text:
- Date Issued: 2020
Rejection of the genetic implications of the “Abundant Centre Hypothesis” in marine mussels
- Ntuli, Noxolo N, Nicastro, Katy R, Zardi, Gerardo I, Assis, Jorge, McQuaid, Christopher D, Teske, Peter R
- Authors: Ntuli, Noxolo N , Nicastro, Katy R , Zardi, Gerardo I , Assis, Jorge , McQuaid, Christopher D , Teske, Peter R
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444839 , vital:74302 , https://www.nature.com/articles/s41598-020-57474-0
- Description: The ‘Abundant-Centre Hypothesis’ is a well-established but controversial hypothesis stating that the abundance of a species is highest at the centre of its range and decreases towards the edges, where conditions are unfavourable. As genetic diversity depends on population size, edge populations are expected to show lower intra-population genetic diversity than core populations, while showing high inter-population genetic divergence. Here, the genetic implications of the Abundant-Centre Hypothesis were tested on two coastal mussels from South Africa that disperse by means of planktonic larvae, the native Perna perna and the invasive Mytilus galloprovincialis. Genetic structure was found within P. perna, which, together with evidence from Lagrangian particle simulations, points to significant reductions in gene flow between sites. Despite this, the expected diversity pattern between centre and edge populations was not found for either species. We conclude that the genetic predictions of the Abundant-Centre Hypothesis are unlikely to be met by high-dispersal species with large population sizes, and may only become evident in species with much lower levels of connectivity.
- Full Text:
- Date Issued: 2020
- Authors: Ntuli, Noxolo N , Nicastro, Katy R , Zardi, Gerardo I , Assis, Jorge , McQuaid, Christopher D , Teske, Peter R
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444839 , vital:74302 , https://www.nature.com/articles/s41598-020-57474-0
- Description: The ‘Abundant-Centre Hypothesis’ is a well-established but controversial hypothesis stating that the abundance of a species is highest at the centre of its range and decreases towards the edges, where conditions are unfavourable. As genetic diversity depends on population size, edge populations are expected to show lower intra-population genetic diversity than core populations, while showing high inter-population genetic divergence. Here, the genetic implications of the Abundant-Centre Hypothesis were tested on two coastal mussels from South Africa that disperse by means of planktonic larvae, the native Perna perna and the invasive Mytilus galloprovincialis. Genetic structure was found within P. perna, which, together with evidence from Lagrangian particle simulations, points to significant reductions in gene flow between sites. Despite this, the expected diversity pattern between centre and edge populations was not found for either species. We conclude that the genetic predictions of the Abundant-Centre Hypothesis are unlikely to be met by high-dispersal species with large population sizes, and may only become evident in species with much lower levels of connectivity.
- Full Text:
- Date Issued: 2020
Sustainable conflict resolution through community based Water, Sanitation and Hygiene (WASH) Planning in fragile and conflict situations: the case of Somalia
- Mafuta, Wonder, Zuwarimwe, Jethro, Kamuzhanje, Joseph, Mwale, Marizvikuru, Chipaike, Ronald
- Authors: Mafuta, Wonder , Zuwarimwe, Jethro , Kamuzhanje, Joseph , Mwale, Marizvikuru , Chipaike, Ronald
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150241 , vital:38952 , https://0-doi.org.wam.seals.ac.za/10.1177/0021909620928104
- Description: The study examines the nature of disputes, which are prevalent in water, sanitation and hygiene (WASH) programming and suggests possible conflict management and resolution mechanisms. An online web-based survey, hosted on the popular Survey Monkey platform, was conducted through the Somalia WASH Cluster to 40 ‘active’ member organisations. A response rate of 73% was achieved. Thematic analysis was conducted using NVivo 12. The type of conflicts identified are as follows: visible versus non-visible benefits, emergency versus development focus, the young and the old, insiders versus outsiders, local versus donor priorities and men versus women. The article goes on to suggest possible conflict resolution mechanisms, which include: planning together with communities, continuum programming, setting up early warning systems, harmonisation of institutions managing WASH resources and the development of localised Memorandums of Understanding. It is recommended that the complexities of conflict and fragility require different approaches. The approaches would apply to both relief and developmental WASH programming.
- Full Text:
- Date Issued: 2020
- Authors: Mafuta, Wonder , Zuwarimwe, Jethro , Kamuzhanje, Joseph , Mwale, Marizvikuru , Chipaike, Ronald
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150241 , vital:38952 , https://0-doi.org.wam.seals.ac.za/10.1177/0021909620928104
- Description: The study examines the nature of disputes, which are prevalent in water, sanitation and hygiene (WASH) programming and suggests possible conflict management and resolution mechanisms. An online web-based survey, hosted on the popular Survey Monkey platform, was conducted through the Somalia WASH Cluster to 40 ‘active’ member organisations. A response rate of 73% was achieved. Thematic analysis was conducted using NVivo 12. The type of conflicts identified are as follows: visible versus non-visible benefits, emergency versus development focus, the young and the old, insiders versus outsiders, local versus donor priorities and men versus women. The article goes on to suggest possible conflict resolution mechanisms, which include: planning together with communities, continuum programming, setting up early warning systems, harmonisation of institutions managing WASH resources and the development of localised Memorandums of Understanding. It is recommended that the complexities of conflict and fragility require different approaches. The approaches would apply to both relief and developmental WASH programming.
- Full Text:
- Date Issued: 2020
The roles of phonological awareness, rapid automatised naming and morphological awareness in isiXhosa:
- Schaefer, Maxine, Probert, Tracy N, Rees, Siȃn
- Authors: Schaefer, Maxine , Probert, Tracy N , Rees, Siȃn
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159950 , vital:40359 , https://doi.org/10.5785/36-1-878
- Description: The current paper examines the unique contributions of phonological awareness (PA), rapid automatised naming (RAN) and morphological awareness (MA) to oral reading fluency (ORF) in isiXhosa. No published study has yet explored the individual contributions of these three cognitive-linguistic skills to reading in isiXhosa. Sixty-six grade 3 home language isiXhosa learners were assessed on these cognitive-linguistic skills. Results from a linear regression analysis showed that only RAN and MA, but not PA, were significant concurrent predictors of ORF. These results suggest that the role of PA in reading in grade 3 learners in isiXhosa may have been overestimated because other important predictors of reading have not been controlled. Our data also suggest that grade 3 isiXhosa learners may make use of the morpheme as a grain size in reading. Our study highlights the need for longitudinal research which explores the roles of PA, MA and RAN in reading development in order to inform reading pedagogy in isiXhosa and other Southern Bantu languages.
- Full Text:
- Date Issued: 2020
- Authors: Schaefer, Maxine , Probert, Tracy N , Rees, Siȃn
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159950 , vital:40359 , https://doi.org/10.5785/36-1-878
- Description: The current paper examines the unique contributions of phonological awareness (PA), rapid automatised naming (RAN) and morphological awareness (MA) to oral reading fluency (ORF) in isiXhosa. No published study has yet explored the individual contributions of these three cognitive-linguistic skills to reading in isiXhosa. Sixty-six grade 3 home language isiXhosa learners were assessed on these cognitive-linguistic skills. Results from a linear regression analysis showed that only RAN and MA, but not PA, were significant concurrent predictors of ORF. These results suggest that the role of PA in reading in grade 3 learners in isiXhosa may have been overestimated because other important predictors of reading have not been controlled. Our data also suggest that grade 3 isiXhosa learners may make use of the morpheme as a grain size in reading. Our study highlights the need for longitudinal research which explores the roles of PA, MA and RAN in reading development in order to inform reading pedagogy in isiXhosa and other Southern Bantu languages.
- Full Text:
- Date Issued: 2020
An Illustration of a Deductive Pattern Matching Procedure in Qualitative Leadership Research:
- Authors: Pearse, Noel J
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149895 , vital:38911 , DOI: 10.34190/JBRM.17.3.004
- Description: Most qualitative studies in business-related research have adopted an inductive approach, in that they explore specific cases and then extract themes, or statements that are more general, from this data. This approach has its shortcomings, including not developing a more systematic body of knowledge of behavioural and social processes that take place in organisations. In contrast, in deductive qualitative research, the theoretical propositions derived from a review of the literature serve as its departure point, informing how the data is collected. Later on in the analysis of data, the researcher uses the propositions to determine if the literature explains the case that was being investigated. Unfortunately, given the relative neglect of deductive qualitative research approaches, there is little guidance and few examples offered that illustrate the application of these techniques. This poses a challenge for researchers, who often need a greater level of structure when it comes to designing and conducting their research. Therefore, the aim of this paper is to illustrate the design of a research protocol that integrates two deductive approaches that are suitable for explanatory case study research, namely deductive thematic analysis and pattern matching. This paper develops a sevenstep process that researchers can follow, for carrying out this type of deductive qualitative research. Using extracts from a research study investigating the leading of organisational change, the steps in this process are illustrated.
- Full Text:
- Date Issued: 2019
- Authors: Pearse, Noel J
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149895 , vital:38911 , DOI: 10.34190/JBRM.17.3.004
- Description: Most qualitative studies in business-related research have adopted an inductive approach, in that they explore specific cases and then extract themes, or statements that are more general, from this data. This approach has its shortcomings, including not developing a more systematic body of knowledge of behavioural and social processes that take place in organisations. In contrast, in deductive qualitative research, the theoretical propositions derived from a review of the literature serve as its departure point, informing how the data is collected. Later on in the analysis of data, the researcher uses the propositions to determine if the literature explains the case that was being investigated. Unfortunately, given the relative neglect of deductive qualitative research approaches, there is little guidance and few examples offered that illustrate the application of these techniques. This poses a challenge for researchers, who often need a greater level of structure when it comes to designing and conducting their research. Therefore, the aim of this paper is to illustrate the design of a research protocol that integrates two deductive approaches that are suitable for explanatory case study research, namely deductive thematic analysis and pattern matching. This paper develops a sevenstep process that researchers can follow, for carrying out this type of deductive qualitative research. Using extracts from a research study investigating the leading of organisational change, the steps in this process are illustrated.
- Full Text:
- Date Issued: 2019
Comparative study of skipjack tuna Katsuwonus pelamis (Scombridae) fishery stocks from the South Atlantic and western Indian oceans
- Dahlet, Lol I, Downey-Breedt, Nicola, Arce, Gabriel, Sauer, Warwick H H, Gasalla, Maria A
- Authors: Dahlet, Lol I , Downey-Breedt, Nicola , Arce, Gabriel , Sauer, Warwick H H , Gasalla, Maria A
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123988 , vital:35523 , https://doi.org/10.3989/scimar.04804.22C
- Description: Temporal and spatial fluctuations in the abundance of oceanic pelagic populations spread geographically around the globe are common (Cushing 1975). The causes of these fluctuations may be exogenous (environmental or anthropogenic) or endogenous to the organism (e.g. ontogenetic drivers) (Ricker 1954). This scenario applies to some tuna stocks, including the skipjack tuna, Katsuwonus pelamis (Linnaeus, 1758), known as bonito-listrado in Brazil, katunkel, or ocean bonito in South Africa, and godhaa (bigger) or kadumas (smaller) skipjack in the Maldives. The skipjack belongs to the family Scombridae and inhabits tropical and subtropical areas of the globe. On average, 85% of skipjack catch occurs in waters warmer than 24°C (Fonteneau 2003). This resource is of particular importance, accounting for 57% of the global industrial tuna catch in 2016, and is mainly processed by the canning industry. Skipjack catches totaled 2.79 million t in 2016 (ISSF 2018), and currently 8.5% of worldwide catches are made by the pole-and line fleet. In Brazil and the Maldives, the resource is well-known. Catches in Brazil were seen to increase until 2014, while in the Maldives, 2006 marked the beginning of a strong and unsettling decline that continued until recent years. Off South Africa, skipjack catches are 1000 to 10000 times lower than those from Brazil and the Maldives, and the highest catches were recorded in 2012.
- Full Text:
- Date Issued: 2019
- Authors: Dahlet, Lol I , Downey-Breedt, Nicola , Arce, Gabriel , Sauer, Warwick H H , Gasalla, Maria A
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123988 , vital:35523 , https://doi.org/10.3989/scimar.04804.22C
- Description: Temporal and spatial fluctuations in the abundance of oceanic pelagic populations spread geographically around the globe are common (Cushing 1975). The causes of these fluctuations may be exogenous (environmental or anthropogenic) or endogenous to the organism (e.g. ontogenetic drivers) (Ricker 1954). This scenario applies to some tuna stocks, including the skipjack tuna, Katsuwonus pelamis (Linnaeus, 1758), known as bonito-listrado in Brazil, katunkel, or ocean bonito in South Africa, and godhaa (bigger) or kadumas (smaller) skipjack in the Maldives. The skipjack belongs to the family Scombridae and inhabits tropical and subtropical areas of the globe. On average, 85% of skipjack catch occurs in waters warmer than 24°C (Fonteneau 2003). This resource is of particular importance, accounting for 57% of the global industrial tuna catch in 2016, and is mainly processed by the canning industry. Skipjack catches totaled 2.79 million t in 2016 (ISSF 2018), and currently 8.5% of worldwide catches are made by the pole-and line fleet. In Brazil and the Maldives, the resource is well-known. Catches in Brazil were seen to increase until 2014, while in the Maldives, 2006 marked the beginning of a strong and unsettling decline that continued until recent years. Off South Africa, skipjack catches are 1000 to 10000 times lower than those from Brazil and the Maldives, and the highest catches were recorded in 2012.
- Full Text:
- Date Issued: 2019
Development of high yielding strain of Pleurotus tuber-regium fructification, nutritional and phylogenetic studies
- Bamigboye, Comfort O, Oloke, Julius K, Dames, Joanna F
- Authors: Bamigboye, Comfort O , Oloke, Julius K , Dames, Joanna F
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448595 , vital:74745 , https://doi.org/10.1007/s13197-019-03786-7
- Description: Mushrooms are nutritionally rich, healthy and medicinal. Pleurotus tuber-regium (Fr.) is one of the nutritious medicinal mushroom found in the tropics and subtropics, but with history of slow growth and low sclerotia yield. In this study, mutants were created by mycelia exposure to ultraviolet irradiation (at a wavelength of 254 nm and a distance of 45 cm), for 3 h and sub-cultured at 30 min interval. The DNA from the wild and mutant strains were extracted, PCR amplified and sequenced. A phylogenetic tree was constructed to show the degree of similarity and differences between the wild and the mutant strains. Fructification studies were conducted on Rhodes grass straw and sawdust to determine the viability of the mutant strains and any nutritional improvement. The wild strain of P. tuber-regium and mutant produced at 30 min (Pt30) cultivated on sawdust and Rhodes straw, yielded sclerotia with biological efficiency of 8.8 and 47.6% respectively. Proximate analysis of the sclerotium showed that the mutant, Pt30, had improved nutritional compositions compared to the wild strain with a total non-structural carbohydrate concentration of 2.41 g as against 0.93 g. Conclusively in this study, better strains of P. tuber-regium were produced with faster growth rate, higher mycelia ramification rate on lignocellulosic substrate and a higher sclerotia yield than the wild P. tuber-regium. It was also established that mutagenesis is capable of improving P. tuber-regium for a successful commercial venture in sclerotia production.
- Full Text:
- Date Issued: 2019
- Authors: Bamigboye, Comfort O , Oloke, Julius K , Dames, Joanna F
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448595 , vital:74745 , https://doi.org/10.1007/s13197-019-03786-7
- Description: Mushrooms are nutritionally rich, healthy and medicinal. Pleurotus tuber-regium (Fr.) is one of the nutritious medicinal mushroom found in the tropics and subtropics, but with history of slow growth and low sclerotia yield. In this study, mutants were created by mycelia exposure to ultraviolet irradiation (at a wavelength of 254 nm and a distance of 45 cm), for 3 h and sub-cultured at 30 min interval. The DNA from the wild and mutant strains were extracted, PCR amplified and sequenced. A phylogenetic tree was constructed to show the degree of similarity and differences between the wild and the mutant strains. Fructification studies were conducted on Rhodes grass straw and sawdust to determine the viability of the mutant strains and any nutritional improvement. The wild strain of P. tuber-regium and mutant produced at 30 min (Pt30) cultivated on sawdust and Rhodes straw, yielded sclerotia with biological efficiency of 8.8 and 47.6% respectively. Proximate analysis of the sclerotium showed that the mutant, Pt30, had improved nutritional compositions compared to the wild strain with a total non-structural carbohydrate concentration of 2.41 g as against 0.93 g. Conclusively in this study, better strains of P. tuber-regium were produced with faster growth rate, higher mycelia ramification rate on lignocellulosic substrate and a higher sclerotia yield than the wild P. tuber-regium. It was also established that mutagenesis is capable of improving P. tuber-regium for a successful commercial venture in sclerotia production.
- Full Text:
- Date Issued: 2019
In Search of the “Goodlife": Border Crossing and Agency in Luis Alberto Urrea's Into the Beautiful North and Graciela Limón's The River Flows North
- Authors: Naidu, Samantha
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158046 , vital:40142 , https://doi.org/10.1080/18125441.2019.16474490
- Description: This article explores representations of complex diasporic subjectivities that resist, or attempt to resist, obsolete nationalist notions of citizenship and identity by crossing the US– Mexico border (and, in so doing, crossing other intangible borders) in search of a better life. Two examples of border literature, Luis Alberto Urrea's Into the Beautiful North (2009) and Graciela Limón's The River Flows North (2009), have been selected for analysis. These texts, in describing various diaspora spaces—to enlist Avtar Brah's term (Cartographies of Diaspora. London: Routledge, 1996)—also examine how those who do not migrate are affected by migration. In Writing the Goodlife: Mexican American Literature and the Environment (Tucson: University of Arizona Press, 2016), Priscilla Solis Ybarra reveals how the past century and a half's Mexican-American literature contains valuable new approaches to creating and sustaining new forms of transnational relations between humans, and ecologically sound relationships between humans and nature.
- Full Text:
- Date Issued: 2019
- Authors: Naidu, Samantha
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158046 , vital:40142 , https://doi.org/10.1080/18125441.2019.16474490
- Description: This article explores representations of complex diasporic subjectivities that resist, or attempt to resist, obsolete nationalist notions of citizenship and identity by crossing the US– Mexico border (and, in so doing, crossing other intangible borders) in search of a better life. Two examples of border literature, Luis Alberto Urrea's Into the Beautiful North (2009) and Graciela Limón's The River Flows North (2009), have been selected for analysis. These texts, in describing various diaspora spaces—to enlist Avtar Brah's term (Cartographies of Diaspora. London: Routledge, 1996)—also examine how those who do not migrate are affected by migration. In Writing the Goodlife: Mexican American Literature and the Environment (Tucson: University of Arizona Press, 2016), Priscilla Solis Ybarra reveals how the past century and a half's Mexican-American literature contains valuable new approaches to creating and sustaining new forms of transnational relations between humans, and ecologically sound relationships between humans and nature.
- Full Text:
- Date Issued: 2019
Management Capacity within Small to Medium Tourism Enterprises (SMTEs) in the Eastern Cape Province
- Mxunyelwa, Siyabonga, Lloyd, Hendrik
- Authors: Mxunyelwa, Siyabonga , Lloyd, Hendrik
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/1962 , vital:39807 , https://www.ajhtl.com/uploads/7/1/6/3/7163688/article_49_vol_8_4__2019_wsu.pdf
- Description: The small to medium tourism enterprises (SMTEs) are recognised as significant contributors to the development of the local and regional economies and create much needed entrepreneurial ventures. Universally, SMTEs play a significant role in the tourism sector. Management of these enterprises by owners and managers seems to face challenges. This paper examines the factors impacting on management capacity with specific focus on the SMTEs in the Eastern Cape Province, South Africa. A systematic random sampling technique was utilised to choose a sample of 320 business respondents from the 2012 database of the Eastern Cape Parks and Tourism Agency, comprising of formally registered small tourism businesses. A total of 310 usable questionnaires was finally obtained. In this study descriptive and inferential statistics were applied. Descriptive statistics were captured to highlight the owners’ characteristics and to consolidate their measurement scores. Utilising inferential statistics, the study undertook an investigation into relationships between demographic variables, business characteristics and factors impacting on management capacity within SMTEs were undertaken. The paper elucidates that a significant relationship was found between business characteristics and demographic variables. Furthermore, skills development, strategic and management knowledge and business leadership factors were compared with the qualifications group. This study adds to the body of knowledge in a predominantly less researched phenomenon of management capacity within SMTEs.
- Full Text:
- Date Issued: 2019
- Authors: Mxunyelwa, Siyabonga , Lloyd, Hendrik
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/1962 , vital:39807 , https://www.ajhtl.com/uploads/7/1/6/3/7163688/article_49_vol_8_4__2019_wsu.pdf
- Description: The small to medium tourism enterprises (SMTEs) are recognised as significant contributors to the development of the local and regional economies and create much needed entrepreneurial ventures. Universally, SMTEs play a significant role in the tourism sector. Management of these enterprises by owners and managers seems to face challenges. This paper examines the factors impacting on management capacity with specific focus on the SMTEs in the Eastern Cape Province, South Africa. A systematic random sampling technique was utilised to choose a sample of 320 business respondents from the 2012 database of the Eastern Cape Parks and Tourism Agency, comprising of formally registered small tourism businesses. A total of 310 usable questionnaires was finally obtained. In this study descriptive and inferential statistics were applied. Descriptive statistics were captured to highlight the owners’ characteristics and to consolidate their measurement scores. Utilising inferential statistics, the study undertook an investigation into relationships between demographic variables, business characteristics and factors impacting on management capacity within SMTEs were undertaken. The paper elucidates that a significant relationship was found between business characteristics and demographic variables. Furthermore, skills development, strategic and management knowledge and business leadership factors were compared with the qualifications group. This study adds to the body of knowledge in a predominantly less researched phenomenon of management capacity within SMTEs.
- Full Text:
- Date Issued: 2019
Paper beads on the move: mobilizing trajectories and subjectivities to shape contemporary art in Uganda
- Authors: Kasozi, Dorah
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145985 , vital:38484 , https://0-doi.org.wam.seals.ac.za/10.1162/afar_a_00459
- Description: Beads cannot simply be viewed as nonrepresentational, decorative entities. In Uganda, the art of paper bead[ing] is empowering women economically while mobilizing new trajectories that reflect the intersecting and shifting landscapes of public space and private space to shape inquiry into gender relationships, art, art-making, and politics.
- Full Text:
- Date Issued: 2019
- Authors: Kasozi, Dorah
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145985 , vital:38484 , https://0-doi.org.wam.seals.ac.za/10.1162/afar_a_00459
- Description: Beads cannot simply be viewed as nonrepresentational, decorative entities. In Uganda, the art of paper bead[ing] is empowering women economically while mobilizing new trajectories that reflect the intersecting and shifting landscapes of public space and private space to shape inquiry into gender relationships, art, art-making, and politics.
- Full Text:
- Date Issued: 2019
An ecosystem service value chain analysis framework: a conceptual paper
- Rawlins, Jonathan M, De Lange, Willem J, Fraser, Gavin C G
- Authors: Rawlins, Jonathan M , De Lange, Willem J , Fraser, Gavin C G
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69321 , vital:29499 , https://doi.org/10.1016/j.ecolecon.2017.12.023
- Description: Modern day societies and economies are becoming increasingly vulnerable to the continued erosion of the stocks and flows of essential ecosystem services. Thus, the management of complex socio-economic systems to effectively provide these essential services has become a global priority policy and academic research area. Understanding how underlying processes and functions contribute towards the provision of final ecosystem services can facilitate improved dissemination of credible, legitimate and salient information to decision-makers. This paper presents an ecosystem service value chain analysis framework that applies basic system dynamics modelling in the form of causal loop diagrams to facilitate an alternative analysis of ecosystem service value chains. A scoping application of the framework is applied to a case study for flood attenuation services in the Baviaanskloof catchment in South Africa. The framework enables the identification of forward linkages and ripple effects in individual value chains of final ecosystem services as well as the identification and assessment of challenges and opportunities within individual causal pathways. Ultimately, providing the potential to advance strategies for improving the efficiency and effectiveness of final ecosystem service provision.
- Full Text: false
- Date Issued: 2018
- Authors: Rawlins, Jonathan M , De Lange, Willem J , Fraser, Gavin C G
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69321 , vital:29499 , https://doi.org/10.1016/j.ecolecon.2017.12.023
- Description: Modern day societies and economies are becoming increasingly vulnerable to the continued erosion of the stocks and flows of essential ecosystem services. Thus, the management of complex socio-economic systems to effectively provide these essential services has become a global priority policy and academic research area. Understanding how underlying processes and functions contribute towards the provision of final ecosystem services can facilitate improved dissemination of credible, legitimate and salient information to decision-makers. This paper presents an ecosystem service value chain analysis framework that applies basic system dynamics modelling in the form of causal loop diagrams to facilitate an alternative analysis of ecosystem service value chains. A scoping application of the framework is applied to a case study for flood attenuation services in the Baviaanskloof catchment in South Africa. The framework enables the identification of forward linkages and ripple effects in individual value chains of final ecosystem services as well as the identification and assessment of challenges and opportunities within individual causal pathways. Ultimately, providing the potential to advance strategies for improving the efficiency and effectiveness of final ecosystem service provision.
- Full Text: false
- Date Issued: 2018
Bird responses to land use change: Guild diversity in a Kenyan coastal forest and adjoining habitats
- Chiawo, David O, Kombe, Wellington N, Craig, Adrian J F K
- Authors: Chiawo, David O , Kombe, Wellington N , Craig, Adrian J F K
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448820 , vital:74763 , https://doi.org/10.1080/01584197.2018.1431052
- Description: Land use change can have profound effects on forest ecology, particularly on the avian community. Arabuko-Sokoke Forest, one of the Important Bird Areas (IBAs) in Kenya, is under threat due to ongoing land use change in the surroundings that could affect species composition of many bird guilds. However, information on the response of different guilds in tropical land use systems is sparse in Africa. We examined the effects of land use on bird guilds in primary forest (Arabuko-Sokoke Forest), adjoining plantations, and neighbouring farmland. Point counts were distributed equally in the three land use systems to survey bird populations. A total of 2600 bird observations was recorded, representing 97 species in five main feeding guilds (frugivores, nectarivores, insectivores, carnivores, and granivores). Granivores were most abundant and diverse in farmland, while carnivores (primarily raptors) utilised all habitats. Insectivores were most diverse in primary forest where vertical heterogeneity of the vegetation and the presence of large fruiting trees significantly influenced their occurrence. Specialist nectarivores were most frequent in primary forest, whereas occasional nectarivores were less abundant there. Contrary to expectation, frugivore diversity showed no significant effect of land use.
- Full Text:
- Date Issued: 2018
Bird responses to land use change: Guild diversity in a Kenyan coastal forest and adjoining habitats
- Authors: Chiawo, David O , Kombe, Wellington N , Craig, Adrian J F K
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448820 , vital:74763 , https://doi.org/10.1080/01584197.2018.1431052
- Description: Land use change can have profound effects on forest ecology, particularly on the avian community. Arabuko-Sokoke Forest, one of the Important Bird Areas (IBAs) in Kenya, is under threat due to ongoing land use change in the surroundings that could affect species composition of many bird guilds. However, information on the response of different guilds in tropical land use systems is sparse in Africa. We examined the effects of land use on bird guilds in primary forest (Arabuko-Sokoke Forest), adjoining plantations, and neighbouring farmland. Point counts were distributed equally in the three land use systems to survey bird populations. A total of 2600 bird observations was recorded, representing 97 species in five main feeding guilds (frugivores, nectarivores, insectivores, carnivores, and granivores). Granivores were most abundant and diverse in farmland, while carnivores (primarily raptors) utilised all habitats. Insectivores were most diverse in primary forest where vertical heterogeneity of the vegetation and the presence of large fruiting trees significantly influenced their occurrence. Specialist nectarivores were most frequent in primary forest, whereas occasional nectarivores were less abundant there. Contrary to expectation, frugivore diversity showed no significant effect of land use.
- Full Text:
- Date Issued: 2018