Clinically established biodegradable long acting injectables
- Nkanga, Christian I, Fisch, Andreas, Rad-Malkshahi, Mazda, Romic, Marieta D, Kittel, Birgit, Ullrich, Thomas, Wang, Jing, Krause, Rui W M, Adler, Sabine, Lammers, Twan, Hennink, Wim E, Ramazani, Farshad
- Authors: Nkanga, Christian I , Fisch, Andreas , Rad-Malkshahi, Mazda , Romic, Marieta D , Kittel, Birgit , Ullrich, Thomas , Wang, Jing , Krause, Rui W M , Adler, Sabine , Lammers, Twan , Hennink, Wim E , Ramazani, Farshad
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193386 , vital:45327 , xlink:href="https://doi.org/10.1016/j.addr.2020.11.008"
- Description: Long acting injectable formulations have been developed to sustain the action of drugs in the body over desired periods of time. These delivery platforms have been utilized for both systemic and local drug delivery applications. This review gives an overview of long acting injectable systems that are currently in clinical use. These products are categorized in three different groups: biodegradable polymeric systems, including microparticles and implants; micro and nanocrystal suspensions and oil-based formulations. Furthermore, the applications of these drug delivery platforms for the management of various chronic diseases are summarized. Finally, this review addresses industrial challenges regarding the development of long acting injectable formulations.
- Full Text:
- Date Issued: 2020
- Authors: Nkanga, Christian I , Fisch, Andreas , Rad-Malkshahi, Mazda , Romic, Marieta D , Kittel, Birgit , Ullrich, Thomas , Wang, Jing , Krause, Rui W M , Adler, Sabine , Lammers, Twan , Hennink, Wim E , Ramazani, Farshad
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193386 , vital:45327 , xlink:href="https://doi.org/10.1016/j.addr.2020.11.008"
- Description: Long acting injectable formulations have been developed to sustain the action of drugs in the body over desired periods of time. These delivery platforms have been utilized for both systemic and local drug delivery applications. This review gives an overview of long acting injectable systems that are currently in clinical use. These products are categorized in three different groups: biodegradable polymeric systems, including microparticles and implants; micro and nanocrystal suspensions and oil-based formulations. Furthermore, the applications of these drug delivery platforms for the management of various chronic diseases are summarized. Finally, this review addresses industrial challenges regarding the development of long acting injectable formulations.
- Full Text:
- Date Issued: 2020
Co-loading of isoniazid-grafted phthalocyanine-in-cyclodextrin and rifampicin in crude soybean lecithin liposomes: Formulation, spectroscopic and biological characterization
- Nkanga, Christian I, Roth, Michael, Walker, Roderick B, Noundou, Xavier S, Krause, Rui W M
- Authors: Nkanga, Christian I , Roth, Michael , Walker, Roderick B , Noundou, Xavier S , Krause, Rui W M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183481 , vital:43999 , xlink:href="https://doi.org/10.1166/jbn.2020.2880"
- Description: An inclusion complex of isoniazid-grafted phthalocyanine with gamma-cyclodextrin (Complex) was co-encapsulated with rifampicin (RIF) in crude soybean lecithin liposomes using a heating method. The encapsulation efficiency (%EE) of the Complex-RIF co-loaded liposomes (Rif-Complex-Lips) was determined using UV-Vis spectrophotometry. Rif-Complex-Lips formulations were evaluated using dynamic light scattering, transmission electron microscopy (TEM), 1H-NMR, absorption and emission spectroscopy. Dialysis was used for drug release study in two different media, pH 6.4 and 7.4. HeLa cells were used to assess potential cytotoxicity, and the uptake by lung fibroblasts and epithelial cells was investigated using fluorescence microscopy. The particle size and Zeta potential of Rif-Complex-Lips were approximately 594 nm and –50 mV. Spectroscopic analyses demonstrated molecular distribution of the cargo within the lipid core, and encapsulation efficiency of 58% for Complex and 86% for RIF. TEM analysis unveiled the existence of spherical nanoparticles in our samples, indicating the presence of liposomes. Rif-Complex-Lips exhibited much higher release rates for both INH and RIF at pH 6.4 compared to those tested at pH 7.4. In addition, there was no cytotoxicity on HeLa cells, but remarkable Rif-Complex-Lips internalization by peripheral lung fibroblasts and epithelial cells. Hence, Rif-Complex-Lips are promising vehicles for intracellular delivery of antimicrobial drugs.
- Full Text:
- Date Issued: 2020
- Authors: Nkanga, Christian I , Roth, Michael , Walker, Roderick B , Noundou, Xavier S , Krause, Rui W M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183481 , vital:43999 , xlink:href="https://doi.org/10.1166/jbn.2020.2880"
- Description: An inclusion complex of isoniazid-grafted phthalocyanine with gamma-cyclodextrin (Complex) was co-encapsulated with rifampicin (RIF) in crude soybean lecithin liposomes using a heating method. The encapsulation efficiency (%EE) of the Complex-RIF co-loaded liposomes (Rif-Complex-Lips) was determined using UV-Vis spectrophotometry. Rif-Complex-Lips formulations were evaluated using dynamic light scattering, transmission electron microscopy (TEM), 1H-NMR, absorption and emission spectroscopy. Dialysis was used for drug release study in two different media, pH 6.4 and 7.4. HeLa cells were used to assess potential cytotoxicity, and the uptake by lung fibroblasts and epithelial cells was investigated using fluorescence microscopy. The particle size and Zeta potential of Rif-Complex-Lips were approximately 594 nm and –50 mV. Spectroscopic analyses demonstrated molecular distribution of the cargo within the lipid core, and encapsulation efficiency of 58% for Complex and 86% for RIF. TEM analysis unveiled the existence of spherical nanoparticles in our samples, indicating the presence of liposomes. Rif-Complex-Lips exhibited much higher release rates for both INH and RIF at pH 6.4 compared to those tested at pH 7.4. In addition, there was no cytotoxicity on HeLa cells, but remarkable Rif-Complex-Lips internalization by peripheral lung fibroblasts and epithelial cells. Hence, Rif-Complex-Lips are promising vehicles for intracellular delivery of antimicrobial drugs.
- Full Text:
- Date Issued: 2020
CO2-induced woody thickening depends strongly on interacting abiotic and biotic factors
- Authors: Raubenheimer, Sarah Lynn
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164646 , vital:41151 , doi:10.21504/10962/164646
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Botany, 2020
- Full Text:
- Date Issued: 2020
- Authors: Raubenheimer, Sarah Lynn
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164646 , vital:41151 , doi:10.21504/10962/164646
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Botany, 2020
- Full Text:
- Date Issued: 2020
Coastal engineers embrace nature: characterizing the metamorphosis in hydraulic engineering in terms of Four Continua
- Slinger, Jill H, Vreugdenhil, Heleen S I
- Authors: Slinger, Jill H , Vreugdenhil, Heleen S I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163846 , vital:41076 , https://doi.org/10.3390/w12092504
- Description: Hydraulic engineering infrastructures, such as reservoirs, dikes, breakwaters, and inlet closures, have significantly impacted ecosystem functioning over the last two centuries. Currently, nature-based solutions are receiving increasing attention in hydraulic engineering projects and research programs. However, there is a lack of reflection on the concomitant, fundamental changes occurring in the field of hydraulic engineering, and coastal engineering in particular, and what this could mean for sustainability. In this article, we signal the shift from conventional to ecosystem-based hydraulic engineering design and characterize this in terms of four continua: (i) the degree of inclusion of ecological knowledge, (ii) the extent to which the full infrastructural lifecycle is addressed, (iii) the complexity of the actor arena taken into account, and (iv) the resulting form of the infrastructural artefact. We support our arguments with two carefully selected, iconic examples from the Netherlands and indicate how the stretching ideals of ecosystem-based engineering could engender further shifts towards sustainability.
- Full Text:
- Date Issued: 2020
- Authors: Slinger, Jill H , Vreugdenhil, Heleen S I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163846 , vital:41076 , https://doi.org/10.3390/w12092504
- Description: Hydraulic engineering infrastructures, such as reservoirs, dikes, breakwaters, and inlet closures, have significantly impacted ecosystem functioning over the last two centuries. Currently, nature-based solutions are receiving increasing attention in hydraulic engineering projects and research programs. However, there is a lack of reflection on the concomitant, fundamental changes occurring in the field of hydraulic engineering, and coastal engineering in particular, and what this could mean for sustainability. In this article, we signal the shift from conventional to ecosystem-based hydraulic engineering design and characterize this in terms of four continua: (i) the degree of inclusion of ecological knowledge, (ii) the extent to which the full infrastructural lifecycle is addressed, (iii) the complexity of the actor arena taken into account, and (iv) the resulting form of the infrastructural artefact. We support our arguments with two carefully selected, iconic examples from the Netherlands and indicate how the stretching ideals of ecosystem-based engineering could engender further shifts towards sustainability.
- Full Text:
- Date Issued: 2020
Combination ecosystem green engineering and early life history processes to enhance the intertidal biodiversity in the Port of East London
- Authors: Mafanya, Sandisiwer
- Date: 2020
- Subjects: Biotic communities -- South Africa -- East London , Perna -- Ecology --South Africa -- South Africa-- East London , Mexilhao mussel -- Ecology -- South Africa -- East London , Habitat (Ecology) -- Modification -- South Africa -- East London , Benthic animals -- Effect of habitat modification on -- South Africa -- East London , Harbors -- Environmental aspects -- South Africa -- East London
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/166376 , vital:41357
- Description: Marine coastal ecosystems are highly impacted by anthropogenic activities, including the development of, and practices within, harbours and/or ports. Artificial structures associated with harbours have a different chemical composition, texture and orientation than that of the natural benthic habitats they have replaced, and are therefore not generally favourable for the settlement and occurrence of indigenous species. Attempts are being made to identify what structures and materials can be used to aid in the rehabilitation of native species within harbours. The aim of this study was to investigate the effects of utilising environmentally-friendly artificial structures (tiles) with varying complexity (crevices and ridges with different depths) with ecological engineers (the indigenous bivalve Perna perna), on the associated benthic biodiversity within an international port in South Africa (Port of East London). The objectives of the study were to test the effects of artificial habitat complexity and the presence of bivalves on 1) the growth, mortality and biomass of a selected model species of ecosystem engineer (P. perna), and 2) the associated intertidal biodiversity. Tiles seeded with bivalves (P. perna) were deployed at two sites in the Port of East London and monitored monthly over a period of 12 months (November 2016-October 2017) to assess survival, growth and associated biodiversity. Environmental variables were also measured every month. The results of the three-way repeated measures ANOVAs indicated that tile treatment (especially high complexity of 2.5 and 5 cm) had an effect on the diversity of mobile species, length, height and biomass of the bivalves used as model ecosystem engineer, indicating the potentials for protection from wave dislodgement and refuge provision. Treatment (especially flat tiles) also had an effect on sessile/sedentary species diversity, indicating the greater proportion of space provided by these non-complex tiles. In addition, month had an effect on the mortality, height and biomass of the bivalves. Mortality was highest in October 2017, while the growth in height and biomass of P. perna were largest in January and October 2017 respectively. The use of artificial tiles also had a positive effect on the survival, growth, and biomass of bivalves (especially the length, weight and dry weight in 2.5 cm and 5 cm complexity). Additionally, this research investigated patterns of settlement and recruitment of the local bivalve population (P. perna) in the Port of East London and adjacent natural coastline to understand the early life history temporal and spatial dynamics of this model ecosystem engineer species. Settlement and recruitment were assessed every month by deploying and replacing artificial collectors for a total period of 19 months (November 2016-May 2018). The results of the two-way ANOVAs indicated that month and site (port vs natural) had an effect on settlement and recruitment of bivalves. Settlement and recruitment of bivalves were highest in July 2017 (port) and March 2018 (natural rocky shore). This study has highlighted that the use of artificial concrete tiles with increased complexity, as well as the investigation of the early stages of mussel populations could be important to consider in a framework of rehabilitation of urban coastal environments such as the Port of East London. Ecological engineering (in terms of increased complexity and heterogeneity) has indeed the potentials to be incorporated in South African programmes aiming at improving natural biodiversity in coastal urban environments. Nonetheless, the spatio-temporal variability of early driver of mussel populations (settlement and recruitment) is also an important feature to be closely monitored if biodiversity in South African coastal armouring is to be enhanced effectively and in the long term.
- Full Text:
- Date Issued: 2020
- Authors: Mafanya, Sandisiwer
- Date: 2020
- Subjects: Biotic communities -- South Africa -- East London , Perna -- Ecology --South Africa -- South Africa-- East London , Mexilhao mussel -- Ecology -- South Africa -- East London , Habitat (Ecology) -- Modification -- South Africa -- East London , Benthic animals -- Effect of habitat modification on -- South Africa -- East London , Harbors -- Environmental aspects -- South Africa -- East London
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/166376 , vital:41357
- Description: Marine coastal ecosystems are highly impacted by anthropogenic activities, including the development of, and practices within, harbours and/or ports. Artificial structures associated with harbours have a different chemical composition, texture and orientation than that of the natural benthic habitats they have replaced, and are therefore not generally favourable for the settlement and occurrence of indigenous species. Attempts are being made to identify what structures and materials can be used to aid in the rehabilitation of native species within harbours. The aim of this study was to investigate the effects of utilising environmentally-friendly artificial structures (tiles) with varying complexity (crevices and ridges with different depths) with ecological engineers (the indigenous bivalve Perna perna), on the associated benthic biodiversity within an international port in South Africa (Port of East London). The objectives of the study were to test the effects of artificial habitat complexity and the presence of bivalves on 1) the growth, mortality and biomass of a selected model species of ecosystem engineer (P. perna), and 2) the associated intertidal biodiversity. Tiles seeded with bivalves (P. perna) were deployed at two sites in the Port of East London and monitored monthly over a period of 12 months (November 2016-October 2017) to assess survival, growth and associated biodiversity. Environmental variables were also measured every month. The results of the three-way repeated measures ANOVAs indicated that tile treatment (especially high complexity of 2.5 and 5 cm) had an effect on the diversity of mobile species, length, height and biomass of the bivalves used as model ecosystem engineer, indicating the potentials for protection from wave dislodgement and refuge provision. Treatment (especially flat tiles) also had an effect on sessile/sedentary species diversity, indicating the greater proportion of space provided by these non-complex tiles. In addition, month had an effect on the mortality, height and biomass of the bivalves. Mortality was highest in October 2017, while the growth in height and biomass of P. perna were largest in January and October 2017 respectively. The use of artificial tiles also had a positive effect on the survival, growth, and biomass of bivalves (especially the length, weight and dry weight in 2.5 cm and 5 cm complexity). Additionally, this research investigated patterns of settlement and recruitment of the local bivalve population (P. perna) in the Port of East London and adjacent natural coastline to understand the early life history temporal and spatial dynamics of this model ecosystem engineer species. Settlement and recruitment were assessed every month by deploying and replacing artificial collectors for a total period of 19 months (November 2016-May 2018). The results of the two-way ANOVAs indicated that month and site (port vs natural) had an effect on settlement and recruitment of bivalves. Settlement and recruitment of bivalves were highest in July 2017 (port) and March 2018 (natural rocky shore). This study has highlighted that the use of artificial concrete tiles with increased complexity, as well as the investigation of the early stages of mussel populations could be important to consider in a framework of rehabilitation of urban coastal environments such as the Port of East London. Ecological engineering (in terms of increased complexity and heterogeneity) has indeed the potentials to be incorporated in South African programmes aiming at improving natural biodiversity in coastal urban environments. Nonetheless, the spatio-temporal variability of early driver of mussel populations (settlement and recruitment) is also an important feature to be closely monitored if biodiversity in South African coastal armouring is to be enhanced effectively and in the long term.
- Full Text:
- Date Issued: 2020
Combination of CTec2 and GH5 or GH26 Endo-Mannanases for Effective Lignocellulosic Biomass Degradation
- Malgas, Samkelo, Pletschke, Brett I
- Authors: Malgas, Samkelo , Pletschke, Brett I
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429397 , vital:72607 , xlink:href="https://doi.org/10.3390/catal10101193"
- Description: Among endo-mannanases, glycoside hydrolase (GH) family 26 enzymes have been shown to be more catalytically active than GH5 enzymes on mannans. However, only GH5 endo-mannanases have been used for the formulation of enzyme cocktails. In this study, Bacillus sp.-derived GH5 and GH26 endo-mannanases were comparatively analysed biochemically for their synergistic action with a commercial cellulase blend, CTec2, during pre-treated lignocellulose degradation. Substrate specificity and thermo-stability studies on mannan substrates showed that GH26 endo-mannanase was more catalytically active and stable than GH5. GH26 also exhibited higher binding affinity for mannan than GH5, while GH5 showed more affinity for lignocellulosic substrates than GH26. Applying the endo-mannanases in combination with CTec2 for lignocellulose degradation led to synergism with a 1.3-fold increase in reducing sugar release compared to when CTec2 was used alone. This study showed that using the activity of endo-mannanases displayed with model substrates is a poor predictor of their activity and synergism on complex lignocelluloses.
- Full Text:
- Date Issued: 2020
- Authors: Malgas, Samkelo , Pletschke, Brett I
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429397 , vital:72607 , xlink:href="https://doi.org/10.3390/catal10101193"
- Description: Among endo-mannanases, glycoside hydrolase (GH) family 26 enzymes have been shown to be more catalytically active than GH5 enzymes on mannans. However, only GH5 endo-mannanases have been used for the formulation of enzyme cocktails. In this study, Bacillus sp.-derived GH5 and GH26 endo-mannanases were comparatively analysed biochemically for their synergistic action with a commercial cellulase blend, CTec2, during pre-treated lignocellulose degradation. Substrate specificity and thermo-stability studies on mannan substrates showed that GH26 endo-mannanase was more catalytically active and stable than GH5. GH26 also exhibited higher binding affinity for mannan than GH5, while GH5 showed more affinity for lignocellulosic substrates than GH26. Applying the endo-mannanases in combination with CTec2 for lignocellulose degradation led to synergism with a 1.3-fold increase in reducing sugar release compared to when CTec2 was used alone. This study showed that using the activity of endo-mannanases displayed with model substrates is a poor predictor of their activity and synergism on complex lignocelluloses.
- Full Text:
- Date Issued: 2020
Combining DNA barcoding and morphology to identify larval fishes from the nearshore environment off the south-east coast of South Africa
- Authors: Somana, Zinzi Sinazo
- Date: 2020
- Subjects: Fishes -- Larvae -- South Africa -- Identification , Fishes -- Genetics -- Research -- Technique , Fishes -- South Africa -- Classification , Genetic markers
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/144605 , vital:38362
- Description: The early life history stages of most marine fish species are undescribed. The problem is, most of these fishes have pelagic larvae which are minute, delicate forms. Linking the larval stage to an adult counterpart is extremely challenging as larvae are morphologically different from the adults. Historically, larval fish identification relied solely on distinguishing morphological characteristics and meristic measurements, which has resulted in taxonomic confusion and misidentification. The introduction of the deoxyribonucleic acid (DNA) barcoding technique as an alternative approach has been successful in positively identifying larval fishes. The correct identification of larval specimens is the key to a better understanding of larval ecology, which underpins the success of any adult fish population. This study aimed to positively identify larval fishes of the south-east coast of South Africa using morphological characteristics and DNA barcoding. Larval and eggs specimens for this study were collected from the shallow nearshore waters of the south-east coast of South Africa. A total of 177 larval specimens were used for morphological analysis. Body shape, gut shape, pigmentation and morphometric measurements (such as body depth, preanal length and total body length) were used to identify each specimen to the family level. In addition, a fragment of mitochondrial cytochrome c oxidase subunit 1 gene (COI) was adopted for sequencing to identify larval fish specimens and fish eggs. Sequences generated from this study were compared to those in the Barcode of Life Database (BOLD). When there were no close matches to a sequence, the GenBank nucleic acid sequence database, maintained by the National Center for Biotechnology Information (NCBI), was used as an alternative. A total of 18 different families were identified through morphology. Seventy-seven of the 177 larval specimens were not subjected to morphological identification due to physical damage. The majority of larvae identified using morphological characteristics belonged to either the Sparidae, Tripterygiidae or Gobiesocidae fish families. Through DNA barcoding, 12 fish families, 16 genera and 18 different species were identified. Ten DNA barcodes (categorised as ‘no match’) from 10 different larval specimens were not identified through any of the online databases. Therefore, the 2% threshold value was used to identify members of the same species. The K2P genetic distance relationships were calculated among the no match sequences and downloaded probability matches from NCBI. This resulted in two unknown specimens assigned to the Blenniidae and Gobiidae. All other taxa were identified to species level, except specimens representing the Gobiidae and Tripterygiidae families. Based on the K2P genetic distances Gobiidae representatives were categorised as members of the Caffrogobius genus. Twenty-eight barcodes represented specimens from the Tripterygiidae. DNA barcode data from COI was analysed using the standard phylogenetic procedures in MEGA6 to examine relationships and differentiation among sequences. These could not be identified to the lowest taxonomic rank due to limited sequence data to compare them with. The sequence data from these specimens gave different results in the two online databases. BOLD results were to family level (Tripterygiidae) and NCBI to the species level (Clinidae: Pavoclinus profundus). Results in this study confirmed the efficiency of the DNA barcoding technique in species level identification of fish larvae. The evidence from genetic barcodes of the Tripterygiidae specimens, supported by morphological characteristics, suggests the need for thorough research to identify the individuals to the species level. The fact that this study identified taxonomically problematic Gobiidae and Tripterygiidae specimens suggests that studies similar to this may highlight additional diversity and help to resolve the taxonomy of other species in these families. However, the lack of reference sequence data from the adult specimens, and especially those with cryptic diversity, were both shortcomings for the positive identification of larvae. With that being said, it shows the necessity for more research to be conducted on barcoding of larvae in general as to accommodate all kinds of species from biodiversity to economic perspectives.
- Full Text:
- Date Issued: 2020
- Authors: Somana, Zinzi Sinazo
- Date: 2020
- Subjects: Fishes -- Larvae -- South Africa -- Identification , Fishes -- Genetics -- Research -- Technique , Fishes -- South Africa -- Classification , Genetic markers
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/144605 , vital:38362
- Description: The early life history stages of most marine fish species are undescribed. The problem is, most of these fishes have pelagic larvae which are minute, delicate forms. Linking the larval stage to an adult counterpart is extremely challenging as larvae are morphologically different from the adults. Historically, larval fish identification relied solely on distinguishing morphological characteristics and meristic measurements, which has resulted in taxonomic confusion and misidentification. The introduction of the deoxyribonucleic acid (DNA) barcoding technique as an alternative approach has been successful in positively identifying larval fishes. The correct identification of larval specimens is the key to a better understanding of larval ecology, which underpins the success of any adult fish population. This study aimed to positively identify larval fishes of the south-east coast of South Africa using morphological characteristics and DNA barcoding. Larval and eggs specimens for this study were collected from the shallow nearshore waters of the south-east coast of South Africa. A total of 177 larval specimens were used for morphological analysis. Body shape, gut shape, pigmentation and morphometric measurements (such as body depth, preanal length and total body length) were used to identify each specimen to the family level. In addition, a fragment of mitochondrial cytochrome c oxidase subunit 1 gene (COI) was adopted for sequencing to identify larval fish specimens and fish eggs. Sequences generated from this study were compared to those in the Barcode of Life Database (BOLD). When there were no close matches to a sequence, the GenBank nucleic acid sequence database, maintained by the National Center for Biotechnology Information (NCBI), was used as an alternative. A total of 18 different families were identified through morphology. Seventy-seven of the 177 larval specimens were not subjected to morphological identification due to physical damage. The majority of larvae identified using morphological characteristics belonged to either the Sparidae, Tripterygiidae or Gobiesocidae fish families. Through DNA barcoding, 12 fish families, 16 genera and 18 different species were identified. Ten DNA barcodes (categorised as ‘no match’) from 10 different larval specimens were not identified through any of the online databases. Therefore, the 2% threshold value was used to identify members of the same species. The K2P genetic distance relationships were calculated among the no match sequences and downloaded probability matches from NCBI. This resulted in two unknown specimens assigned to the Blenniidae and Gobiidae. All other taxa were identified to species level, except specimens representing the Gobiidae and Tripterygiidae families. Based on the K2P genetic distances Gobiidae representatives were categorised as members of the Caffrogobius genus. Twenty-eight barcodes represented specimens from the Tripterygiidae. DNA barcode data from COI was analysed using the standard phylogenetic procedures in MEGA6 to examine relationships and differentiation among sequences. These could not be identified to the lowest taxonomic rank due to limited sequence data to compare them with. The sequence data from these specimens gave different results in the two online databases. BOLD results were to family level (Tripterygiidae) and NCBI to the species level (Clinidae: Pavoclinus profundus). Results in this study confirmed the efficiency of the DNA barcoding technique in species level identification of fish larvae. The evidence from genetic barcodes of the Tripterygiidae specimens, supported by morphological characteristics, suggests the need for thorough research to identify the individuals to the species level. The fact that this study identified taxonomically problematic Gobiidae and Tripterygiidae specimens suggests that studies similar to this may highlight additional diversity and help to resolve the taxonomy of other species in these families. However, the lack of reference sequence data from the adult specimens, and especially those with cryptic diversity, were both shortcomings for the positive identification of larvae. With that being said, it shows the necessity for more research to be conducted on barcoding of larvae in general as to accommodate all kinds of species from biodiversity to economic perspectives.
- Full Text:
- Date Issued: 2020
Come listen quickly
- Authors: Gouws, Leigh-Anne
- Date: 2020
- Subjects: South African fiction (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/141559 , vital:37985
- Description: Creative work portfolio.
- Full Text:
- Date Issued: 2020
- Authors: Gouws, Leigh-Anne
- Date: 2020
- Subjects: South African fiction (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/141559 , vital:37985
- Description: Creative work portfolio.
- Full Text:
- Date Issued: 2020
Commonplaces
- Authors: Orsmond, Joseph Granger
- Date: 2020
- Subjects: South African fiction (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/144061 , vital:38307
- Description: My thesis is a collection of short to medium length poems. All of the subject matter is sustained by reflections, anecdotes or stories. The pieces in the collection are concerned with experiences linked to the seemingly ordinary and mundane. In this regard, I am inspired by how Alan Ziegler (in “Tales of Teaching” and Love at First Sight) and Raymond Carver (All of Us: The collected Poems) find stories in subject matter which is so commonplace, that it is often ignored creatively. Likewise, the lyricism and modes of expression of William Carlos Williams, Federico García Lorca and Luis Cernuda have informed how I write and structure my poetry.
- Full Text:
- Date Issued: 2020
- Authors: Orsmond, Joseph Granger
- Date: 2020
- Subjects: South African fiction (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/144061 , vital:38307
- Description: My thesis is a collection of short to medium length poems. All of the subject matter is sustained by reflections, anecdotes or stories. The pieces in the collection are concerned with experiences linked to the seemingly ordinary and mundane. In this regard, I am inspired by how Alan Ziegler (in “Tales of Teaching” and Love at First Sight) and Raymond Carver (All of Us: The collected Poems) find stories in subject matter which is so commonplace, that it is often ignored creatively. Likewise, the lyricism and modes of expression of William Carlos Williams, Federico García Lorca and Luis Cernuda have informed how I write and structure my poetry.
- Full Text:
- Date Issued: 2020
Comparative analysis of the known Hop1b and the novel Hop1a isoforms of the Hop gene
- Authors: Makhubu, Portia
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164311 , vital:41108 , doi:10.21504/10962/164311
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Biochemistry and Microbiology, 2020
- Full Text:
- Date Issued: 2020
- Authors: Makhubu, Portia
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164311 , vital:41108 , doi:10.21504/10962/164311
- Description: Thesis (PhD)--Rhodes University, Faculty of Science, Biochemistry and Microbiology, 2020
- Full Text:
- Date Issued: 2020
Compounds isolation and biological activities of Piptadeniastrum africanum (hook. f.) Brennan (Fabaceae) roots:
- Teinkela, Jean E M, Noundou, Xavier S, Mimba, Jeanne E Z, Meyer, Franck, Tabouguia, Octavie M, Nguedia, Jules C A, Hoppe, Heinrich C, Krause, Rui W M, Wintjens, René, Azebaze, Anatole G B
- Authors: Teinkela, Jean E M , Noundou, Xavier S , Mimba, Jeanne E Z , Meyer, Franck , Tabouguia, Octavie M , Nguedia, Jules C A , Hoppe, Heinrich C , Krause, Rui W M , Wintjens, René , Azebaze, Anatole G B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150084 , vital:38938 , https://doi.org/10.1016/j.jep.2020.112716
- Description: The dicotyledonous plant Piptadeniastrum africanum (hook.f.) Brennan (Fabaceae) is used in traditional medicine to treat various human complaints including bronchitis, coughing, urino-genital ailments, meningitis, abdominal pain, treatment of wounds, malaria and gastrointestinal ailments, and is used as a purgative and worm expeller. The present study describes the phytochemical investigation and the determination of the antimicrobial, antiplasmodial and antitrypanosomal activities of crude extract, fractions and compounds extracted from Piptadeniastrum africanum roots.
- Full Text:
- Date Issued: 2020
- Authors: Teinkela, Jean E M , Noundou, Xavier S , Mimba, Jeanne E Z , Meyer, Franck , Tabouguia, Octavie M , Nguedia, Jules C A , Hoppe, Heinrich C , Krause, Rui W M , Wintjens, René , Azebaze, Anatole G B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150084 , vital:38938 , https://doi.org/10.1016/j.jep.2020.112716
- Description: The dicotyledonous plant Piptadeniastrum africanum (hook.f.) Brennan (Fabaceae) is used in traditional medicine to treat various human complaints including bronchitis, coughing, urino-genital ailments, meningitis, abdominal pain, treatment of wounds, malaria and gastrointestinal ailments, and is used as a purgative and worm expeller. The present study describes the phytochemical investigation and the determination of the antimicrobial, antiplasmodial and antitrypanosomal activities of crude extract, fractions and compounds extracted from Piptadeniastrum africanum roots.
- Full Text:
- Date Issued: 2020
Comprehensive data on the mechanical properties and biodegradation profile of polylactide composites developed for hard tissue repairs
- Aworinde, Abraham K, Adeosun, Samson O, Oyawale, Festus A, Emagbetere, Eyere, Ishola, Felix A, Olatunji, Obafemi, Akinlab, Stephen, Oyedepo, Sunday O, Ajayi, Oluseyi O, Akinlabi, Esther T
- Authors: Aworinde, Abraham K , Adeosun, Samson O , Oyawale, Festus A , Emagbetere, Eyere , Ishola, Felix A , Olatunji, Obafemi , Akinlab, Stephen , Oyedepo, Sunday O , Ajayi, Oluseyi O , Akinlabi, Esther T
- Date: 2020
- Subjects: Regeneration (Biology) , Vickers microhardness , Melt-blending technique
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3149 , vital:43158 , https://doi.org/10.1016/j.dib.2020.106107
- Description: Africa, the ancestral home of all modern humans, is the most informative continent for understanding the human genome and its contribution to complex disease. To better understand the genetics of schizophrenia, we studied the illness in the Xhosa population of South Africa, recruiting 909 cases and 917 age-, gender-, and residence-matched controls. Individuals with schizophrenia were significantly more likely than controls to harbor private, severely damaging mutations in genes that are critical to synaptic function, including neural circuitry mediated by the neurotransmitters glutamine, γ-aminobutyric acid, and dopamine. Schizophrenia is genetically highly heterogeneous, involving severe ultrarare mutations in genes that are critical to synaptic plasticity. The depth of genetic variation in Africa revealed this relationship with a moderate sample size and informed our understanding of the genetics of schizophrenia worldwide.
- Full Text:
- Date Issued: 2020
- Authors: Aworinde, Abraham K , Adeosun, Samson O , Oyawale, Festus A , Emagbetere, Eyere , Ishola, Felix A , Olatunji, Obafemi , Akinlab, Stephen , Oyedepo, Sunday O , Ajayi, Oluseyi O , Akinlabi, Esther T
- Date: 2020
- Subjects: Regeneration (Biology) , Vickers microhardness , Melt-blending technique
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3149 , vital:43158 , https://doi.org/10.1016/j.dib.2020.106107
- Description: Africa, the ancestral home of all modern humans, is the most informative continent for understanding the human genome and its contribution to complex disease. To better understand the genetics of schizophrenia, we studied the illness in the Xhosa population of South Africa, recruiting 909 cases and 917 age-, gender-, and residence-matched controls. Individuals with schizophrenia were significantly more likely than controls to harbor private, severely damaging mutations in genes that are critical to synaptic function, including neural circuitry mediated by the neurotransmitters glutamine, γ-aminobutyric acid, and dopamine. Schizophrenia is genetically highly heterogeneous, involving severe ultrarare mutations in genes that are critical to synaptic plasticity. The depth of genetic variation in Africa revealed this relationship with a moderate sample size and informed our understanding of the genetics of schizophrenia worldwide.
- Full Text:
- Date Issued: 2020
Conceptualisations of and responses to plagiarism in the South African higher education system
- Mphahlele, Martha Matee (Amanda)
- Authors: Mphahlele, Martha Matee (Amanda)
- Date: 2020
- Subjects: Plagiarism , Plagiarism -- Prevention -- South Africa , Education, Higher -- Moral and ethical aspects , Education, Higher -- South Africa , Cheating (Education) -- South Africa , College students -- Legal status, laws, etc. -- South Africa , College discipline -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/162642 , vital:40963
- Description: Violations of academic integrity are a cause for concern in universities around the world and plagiarism is one of the most significant examples of these academic integrity issues with which universities are grappling . The approach taken to managing plagiarism depends to a large extent on the understanding of the phenomenon within institutions. This study investigated how plagiarism is conceptualised and responded to in the South African Higher Education system and how this impacts on teaching and learning. Data was collected from 25 out of the 26 South African public universities; the missing university had just been established and did not yet have policies or processes in place. The data was primarily in the form of documents known in these institutions as ‘plagiarism policies’, along with a wealth of other related policies and reports. This was supplemented by interviews as a means of verifying the document analysis with seven plagiarism committee members from across the three institutional types in South Africa, namely: traditional universities, comprehensive universities, and universities of technology. Using Bhaskar’s (2008) critical realism as a metatheory and Archer’s (1995) social realism as both a substantive theory and analytical framework, the experiences and events of plagiarism management were critically examined. Critical realism consider s these experiences and events at the level of the e mpirical and the actual , in order to identify the mechanisms at the l evel of the r eal from which these emerge. Social realism argues that when undertaking such an analysis in the social world, this entails identifying the emergent properties of both the parts (structure and culture) and people (agents). Therefore, the data was analysed using Archer’s analytical dualism to identify structural, cultural and agential mechanisms shaping the understanding of plagiarism and the practices associated with managing the phenomenon. The study found that dominant in the sector was an un derstanding of plagiarism as always being an intentional act, with implications for teaching and learning practices, which then focused on identifying and punishing incidents of plagiarism in student writing. A legal discourse was found to permeate the universities’ plagiarism management systems, such that most procedures replicated the legal framework. This was seen to undermine the identity of universities as teaching and learning spaces and of students as novice members of the disciplinary fields. The study further highlighted that due to plagiarism being perceived as an intentional act, punishment in almost all universities is prioritised as the key means of attending to plagiarism in the se institutions. This emerged as a structural constraint to students’ acquisition of academic writing norms. Such understandings and approaches were seen to be complementary to the risk-aversion of many institutions in a globalised era of university rankings. As increased bureaucracy has been put in place to attend to incidents of plagiarism, including obligatory reporting thereof, an unintentional consequence emerged, where it was at times simpler for academics to ignore incidences of plagiarism than to act on them. Turnitin was frequently referred to across the data as the preferred text - matching tool, but Turnitin together with other text-matching tools , was often used in a way that complemented the understanding of plagiarism as always being an intentional act. The stu dy found that text - matching software was largely misunderstood to be plagiarism software, where the similarity index was perceived to be a measure of plagiarism. This led to an understanding that students needed to paraphrase texts in order to avoid detect ion by the program me, and this may inadvertently encourage plagiarism , as students are taught to write towards the software. The research found that in those instances where educational responses to plagiarism were in place, they often demonstrated a lack of understanding of academic literacies development and the extent to which norms of knowledge production are disciplinary specific. Most (but not all) of the data about educational responses focused on add-on workshops and the signing of a declaration form, indicating that the student has not plagiarised. The workshops were seen to emphasise technical skills, such as the punctuation norms of referencing, and were often offered in a generic format by people outside of the target disciplines. These workshops were found to ignore the connection between the technical skills of referencing and the norms of knowledge construction, with a potential deleterious effect on the development of authorial identity. Finally, the data showed a few instances where particular institutions acknowledged that plagiarism occurs along a continuum, where on one side is intentional plagiarism associated with cheating and requiring punishment, and on the other side is unintentional plagiarism, which is understood to require an educational response , and was seen to emerge from either a lack of understanding of academic literacy norms , or from negligence. Literacy development with regard to taking on the norms of knowledge-making in the academy was seen to be a complex and lengthy process that was fundamental to educational endeavours of facilitating epistemological access, while cases of negligence were seen to be mainly caused by technical oversight rather than a lack of access to the relevant knowledge production norms. The study concludes by arguing that cases of intentional plagiarism require quick and appropriate punishment, but that there also needs to be an institution-wide understanding that unintentional plagiarism often emerges from students failing to access the specific knowledge-making norms of the discipline. There is thus a need for academics to be aware of the complexities related to taking on literacy practices, and who also understand the role of feedback in this process. But it ought not to be assumed that academics would have such insights simply by virtue of their expertise in the discipline. These academics need to have carefully constructed staff development support, as they take on such pedagogical approaches. The study argues that the dominant conceptualisation of plagiarism in the domain of culture as an intentional act and the complementary policies and processes in the domain of structure as focusing on detecting and punishing incidents of plagiarism, fail to address plagiarism in appropriate educational ways.
- Full Text:
- Date Issued: 2020
- Authors: Mphahlele, Martha Matee (Amanda)
- Date: 2020
- Subjects: Plagiarism , Plagiarism -- Prevention -- South Africa , Education, Higher -- Moral and ethical aspects , Education, Higher -- South Africa , Cheating (Education) -- South Africa , College students -- Legal status, laws, etc. -- South Africa , College discipline -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/162642 , vital:40963
- Description: Violations of academic integrity are a cause for concern in universities around the world and plagiarism is one of the most significant examples of these academic integrity issues with which universities are grappling . The approach taken to managing plagiarism depends to a large extent on the understanding of the phenomenon within institutions. This study investigated how plagiarism is conceptualised and responded to in the South African Higher Education system and how this impacts on teaching and learning. Data was collected from 25 out of the 26 South African public universities; the missing university had just been established and did not yet have policies or processes in place. The data was primarily in the form of documents known in these institutions as ‘plagiarism policies’, along with a wealth of other related policies and reports. This was supplemented by interviews as a means of verifying the document analysis with seven plagiarism committee members from across the three institutional types in South Africa, namely: traditional universities, comprehensive universities, and universities of technology. Using Bhaskar’s (2008) critical realism as a metatheory and Archer’s (1995) social realism as both a substantive theory and analytical framework, the experiences and events of plagiarism management were critically examined. Critical realism consider s these experiences and events at the level of the e mpirical and the actual , in order to identify the mechanisms at the l evel of the r eal from which these emerge. Social realism argues that when undertaking such an analysis in the social world, this entails identifying the emergent properties of both the parts (structure and culture) and people (agents). Therefore, the data was analysed using Archer’s analytical dualism to identify structural, cultural and agential mechanisms shaping the understanding of plagiarism and the practices associated with managing the phenomenon. The study found that dominant in the sector was an un derstanding of plagiarism as always being an intentional act, with implications for teaching and learning practices, which then focused on identifying and punishing incidents of plagiarism in student writing. A legal discourse was found to permeate the universities’ plagiarism management systems, such that most procedures replicated the legal framework. This was seen to undermine the identity of universities as teaching and learning spaces and of students as novice members of the disciplinary fields. The study further highlighted that due to plagiarism being perceived as an intentional act, punishment in almost all universities is prioritised as the key means of attending to plagiarism in the se institutions. This emerged as a structural constraint to students’ acquisition of academic writing norms. Such understandings and approaches were seen to be complementary to the risk-aversion of many institutions in a globalised era of university rankings. As increased bureaucracy has been put in place to attend to incidents of plagiarism, including obligatory reporting thereof, an unintentional consequence emerged, where it was at times simpler for academics to ignore incidences of plagiarism than to act on them. Turnitin was frequently referred to across the data as the preferred text - matching tool, but Turnitin together with other text-matching tools , was often used in a way that complemented the understanding of plagiarism as always being an intentional act. The stu dy found that text - matching software was largely misunderstood to be plagiarism software, where the similarity index was perceived to be a measure of plagiarism. This led to an understanding that students needed to paraphrase texts in order to avoid detect ion by the program me, and this may inadvertently encourage plagiarism , as students are taught to write towards the software. The research found that in those instances where educational responses to plagiarism were in place, they often demonstrated a lack of understanding of academic literacies development and the extent to which norms of knowledge production are disciplinary specific. Most (but not all) of the data about educational responses focused on add-on workshops and the signing of a declaration form, indicating that the student has not plagiarised. The workshops were seen to emphasise technical skills, such as the punctuation norms of referencing, and were often offered in a generic format by people outside of the target disciplines. These workshops were found to ignore the connection between the technical skills of referencing and the norms of knowledge construction, with a potential deleterious effect on the development of authorial identity. Finally, the data showed a few instances where particular institutions acknowledged that plagiarism occurs along a continuum, where on one side is intentional plagiarism associated with cheating and requiring punishment, and on the other side is unintentional plagiarism, which is understood to require an educational response , and was seen to emerge from either a lack of understanding of academic literacy norms , or from negligence. Literacy development with regard to taking on the norms of knowledge-making in the academy was seen to be a complex and lengthy process that was fundamental to educational endeavours of facilitating epistemological access, while cases of negligence were seen to be mainly caused by technical oversight rather than a lack of access to the relevant knowledge production norms. The study concludes by arguing that cases of intentional plagiarism require quick and appropriate punishment, but that there also needs to be an institution-wide understanding that unintentional plagiarism often emerges from students failing to access the specific knowledge-making norms of the discipline. There is thus a need for academics to be aware of the complexities related to taking on literacy practices, and who also understand the role of feedback in this process. But it ought not to be assumed that academics would have such insights simply by virtue of their expertise in the discipline. These academics need to have carefully constructed staff development support, as they take on such pedagogical approaches. The study argues that the dominant conceptualisation of plagiarism in the domain of culture as an intentional act and the complementary policies and processes in the domain of structure as focusing on detecting and punishing incidents of plagiarism, fail to address plagiarism in appropriate educational ways.
- Full Text:
- Date Issued: 2020
Conclusion: The diversity of contemporary African foreign policy: Selecting Signifiers to explain Agency
- Authors: Bischoff, Paul, 1954-
- Date: 2020
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/161681 , vital:40654 , ISBN 9780367348281 , https://www.routledge.com/African-Foreign-Policies-Selecting-Signifiers-to-Explain-Agency/Bischoff/p/book/9780367348281
- Description: This book explores, at a time when several powers have become serious players on the continent, aspects of African agency, past and present, by African writers on foreign policy, representative of geography, language and state size.
- Full Text:
- Date Issued: 2020
- Authors: Bischoff, Paul, 1954-
- Date: 2020
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/161681 , vital:40654 , ISBN 9780367348281 , https://www.routledge.com/African-Foreign-Policies-Selecting-Signifiers-to-Explain-Agency/Bischoff/p/book/9780367348281
- Description: This book explores, at a time when several powers have become serious players on the continent, aspects of African agency, past and present, by African writers on foreign policy, representative of geography, language and state size.
- Full Text:
- Date Issued: 2020
Congruence between fine-scale genetic breaks and dispersal potential in an estuarine seaweed across multiple transition zones:
- Nicastro, Katy R, Assis, Jorge, Serrão, Ester A, Pearson, Gareth A, Neiva, Joao, Valero, Myriam, Jacinto, Rita, Zardi, Gerardo I
- Authors: Nicastro, Katy R , Assis, Jorge , Serrão, Ester A , Pearson, Gareth A , Neiva, Joao , Valero, Myriam , Jacinto, Rita , Zardi, Gerardo I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149873 , vital:38908 , https://0-doi.org.wam.seals.ac.za/10.1093/icesjms/fsz179
- Description: Genetic structure in biogeographical transition zones can be shaped by several factors including limited dispersal across barriers, admixture following secondary contact, differential selection, and mating incompatibility. A striking example is found in Northwest France and Northwest Spain, where the estuarine seaweed Fucus ceranoides L. exhibits sharp, regional genetic clustering. This pattern has been related to historical population fragmentation and divergence into distinct glacial refugia, followed by post-glacial expansion and secondary contact. The contemporary persistence of sharp ancient genetic breaks between nearby estuaries has been attributed to prior colonization effects (density barriers) but the effect of oceanographic barriers has not been tested. Here, through a combination of mesoscale sampling (15 consecutive populations) and population genetic data (mtIGS) in NW France, we define regional genetic disjunctions similar to those described in NW Iberia. Most importantly, using high resolution dispersal simulations for Brittany and Iberian populations, we provide evidence for a central role of contemporary hydrodynamics in maintaining genetic breaks across these two major biogeographic transition zones. Our findings further show the importance of a comprehensive understanding of oceanographic regimes in hydrodynamically complex coastal regions to explain the maintenance of sharp genetic breaks along continuously populated coastlines.
- Full Text:
- Date Issued: 2020
- Authors: Nicastro, Katy R , Assis, Jorge , Serrão, Ester A , Pearson, Gareth A , Neiva, Joao , Valero, Myriam , Jacinto, Rita , Zardi, Gerardo I
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149873 , vital:38908 , https://0-doi.org.wam.seals.ac.za/10.1093/icesjms/fsz179
- Description: Genetic structure in biogeographical transition zones can be shaped by several factors including limited dispersal across barriers, admixture following secondary contact, differential selection, and mating incompatibility. A striking example is found in Northwest France and Northwest Spain, where the estuarine seaweed Fucus ceranoides L. exhibits sharp, regional genetic clustering. This pattern has been related to historical population fragmentation and divergence into distinct glacial refugia, followed by post-glacial expansion and secondary contact. The contemporary persistence of sharp ancient genetic breaks between nearby estuaries has been attributed to prior colonization effects (density barriers) but the effect of oceanographic barriers has not been tested. Here, through a combination of mesoscale sampling (15 consecutive populations) and population genetic data (mtIGS) in NW France, we define regional genetic disjunctions similar to those described in NW Iberia. Most importantly, using high resolution dispersal simulations for Brittany and Iberian populations, we provide evidence for a central role of contemporary hydrodynamics in maintaining genetic breaks across these two major biogeographic transition zones. Our findings further show the importance of a comprehensive understanding of oceanographic regimes in hydrodynamically complex coastal regions to explain the maintenance of sharp genetic breaks along continuously populated coastlines.
- Full Text:
- Date Issued: 2020
Conservation implications of fine scale population genetic structure of Ficus species in South African forests:
- Deng, Jun-Yin, van Noort, Simon, Compton, Stephen G, Chen, Yan, Greeff, Jaco M
- Authors: Deng, Jun-Yin , van Noort, Simon , Compton, Stephen G , Chen, Yan , Greeff, Jaco M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163838 , vital:41074 , ttps://doi.org/10.1016/j.foreco.2020.118387
- Description: Genetic considerations are rarely applied in forest conservation management strategies, but forest fragmentation can reduce pollen and seed dispersal both between and within isolated fragments. Gene flow and immigration rates determine the extent to which individual plants are related to each other at different distances from themselves. This gradation in relatedness is known as a population's fine scale spatial genetic structure (SGS). Specifically, reduced but clumped immigration from distant fragments reduces fine scale SGS, whereas reduced gene flow within fragments increases fine scale SGS. In addition, non-random mortality caused by post-dispersal ecological processes can also affect SGS. We studied the effects of fragmentation on the fine scale SGS of Ficus species with different habitat preferences and distributional ranges in an archipelago of South African forest patches.
- Full Text:
- Date Issued: 2020
- Authors: Deng, Jun-Yin , van Noort, Simon , Compton, Stephen G , Chen, Yan , Greeff, Jaco M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163838 , vital:41074 , ttps://doi.org/10.1016/j.foreco.2020.118387
- Description: Genetic considerations are rarely applied in forest conservation management strategies, but forest fragmentation can reduce pollen and seed dispersal both between and within isolated fragments. Gene flow and immigration rates determine the extent to which individual plants are related to each other at different distances from themselves. This gradation in relatedness is known as a population's fine scale spatial genetic structure (SGS). Specifically, reduced but clumped immigration from distant fragments reduces fine scale SGS, whereas reduced gene flow within fragments increases fine scale SGS. In addition, non-random mortality caused by post-dispersal ecological processes can also affect SGS. We studied the effects of fragmentation on the fine scale SGS of Ficus species with different habitat preferences and distributional ranges in an archipelago of South African forest patches.
- Full Text:
- Date Issued: 2020
Conserved bacterial genomes from two geographically isolated peritidal stromatolite formations shed light on potential functional guilds
- Waterworth, Samantha C, Isemonger, Eric W, Rees, Evan R, Dorrington, Rosemary A
- Authors: Waterworth, Samantha C , Isemonger, Eric W , Rees, Evan R , Dorrington, Rosemary A
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429411 , vital:72608 , xlink:href="https://doi.org/10.1111/1758-2229.12916"
- Description: Stromatolites are complex microbial mats that form lithified layers. Fossilized stromatolites are the oldest evidence of cellular life on Earth, dating back over3.4 billion years. Modern stromatolites are relatively rare but may provide clues about the function and evolution of their ancient counterparts. In this study, we focus on peritidal stromatolites occurring at Cape Recife and Schoenmakerskop on the southeastern South African coastline, the former being morphologically and structurally similar to fossilized phosphatic stromatolites formations. Using assembled shotgun metagenomic analysis, we obtained 183 genomic bins, of which the most dominant taxa were from the Cyanobacteria phylum. We identified functional gene sets in genomic bins conserved across two geographically isolated stromatolite formations, which included relatively high copy numbers of genes involved in the reduction of nitrates and phosphatic compounds. Additionally, we found little evidence of Archaeal species in these stromatolites, suggesting that they may not play an important role in peritidal stromatolite formations, as proposed for hypersaline formations.
- Full Text:
- Date Issued: 2020
- Authors: Waterworth, Samantha C , Isemonger, Eric W , Rees, Evan R , Dorrington, Rosemary A
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429411 , vital:72608 , xlink:href="https://doi.org/10.1111/1758-2229.12916"
- Description: Stromatolites are complex microbial mats that form lithified layers. Fossilized stromatolites are the oldest evidence of cellular life on Earth, dating back over3.4 billion years. Modern stromatolites are relatively rare but may provide clues about the function and evolution of their ancient counterparts. In this study, we focus on peritidal stromatolites occurring at Cape Recife and Schoenmakerskop on the southeastern South African coastline, the former being morphologically and structurally similar to fossilized phosphatic stromatolites formations. Using assembled shotgun metagenomic analysis, we obtained 183 genomic bins, of which the most dominant taxa were from the Cyanobacteria phylum. We identified functional gene sets in genomic bins conserved across two geographically isolated stromatolite formations, which included relatively high copy numbers of genes involved in the reduction of nitrates and phosphatic compounds. Additionally, we found little evidence of Archaeal species in these stromatolites, suggesting that they may not play an important role in peritidal stromatolite formations, as proposed for hypersaline formations.
- Full Text:
- Date Issued: 2020
Conserving land for people: transformative adaptive co-management of sustainable protected areas in the eastern Democratic Republic of Congo
- Authors: Kalyongo, Kujirakwinja Deo
- Date: 2020
- Subjects: Protected areas -- Congo (Democratic Republic) , Protected areas -- Government policy -- Congo (Democratic Republic) , Protected areas -- Management -- Congo (Democratic Republic) , Conservation of natural resources -- Congo (Democratic Republic)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/165912 , vital:41296
- Description: Conservation practices and approaches in the Democratic Republic of Congo (DRC), as in other parts of the world, have evolved from traditional to fortress and collaborative contemporary approaches such as adaptive co-management. These approaches aim to include multiple decision-makers using diversified resources and, existing formal and informal governance structures. Collaborative approaches also consider conflict resolution and external factors that can influence conservation outputs and outcomes. In the DRC context, conflicts over resources are related not only to resource access and power but also to the ineffectiveness of collaborative approaches that exclude stakeholders such as local communities. These conflicts have negatively affected protected areas and weakened the management and governance of protected areas. Therefore, evolving approaches such as adaptive co-management that consider power relations, the multi-scaled involvement of actors and learning loops to adjust strategies are seen as better options to improve the governance of protected areas and minimise the degradation of key ecosystems. My research explored the gazettement processes of three protected areas in the eastern DRC (Itombwe, Kabobo and Okapi Reserves). I focused on the influence of social-political, historical and psychological factors on the management and governance of protected areas in the DRC. In addition, the research reveals the inclusive gazettement processes of protected areas is the foundation of successful co-management approaches. I found that values and good governance practices play a key role in influencing local perceptions and support to conservation interventions. Whilst some conservation practitioners believe that economic benefits to communities are the most predominant motivating factor, I found that good conservation management practices can motivate communities to support protected area management. Bad management practices were related not only to inadequate conservation approaches and practices but also to factors such as corruption, inadequate law enforcement and the inappropriate equipment of rangers. Therefore, I suggest that long term protected area management in DRC should consider how the value of resources for communities and protected areas have been changing throughout the history of conservation, and how to best share power and responsibilities with local resource users and stakeholders. This is only possible if conservation practices and approaches, governance process and institutions are transformed at multiple levels.
- Full Text:
- Date Issued: 2020
- Authors: Kalyongo, Kujirakwinja Deo
- Date: 2020
- Subjects: Protected areas -- Congo (Democratic Republic) , Protected areas -- Government policy -- Congo (Democratic Republic) , Protected areas -- Management -- Congo (Democratic Republic) , Conservation of natural resources -- Congo (Democratic Republic)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/165912 , vital:41296
- Description: Conservation practices and approaches in the Democratic Republic of Congo (DRC), as in other parts of the world, have evolved from traditional to fortress and collaborative contemporary approaches such as adaptive co-management. These approaches aim to include multiple decision-makers using diversified resources and, existing formal and informal governance structures. Collaborative approaches also consider conflict resolution and external factors that can influence conservation outputs and outcomes. In the DRC context, conflicts over resources are related not only to resource access and power but also to the ineffectiveness of collaborative approaches that exclude stakeholders such as local communities. These conflicts have negatively affected protected areas and weakened the management and governance of protected areas. Therefore, evolving approaches such as adaptive co-management that consider power relations, the multi-scaled involvement of actors and learning loops to adjust strategies are seen as better options to improve the governance of protected areas and minimise the degradation of key ecosystems. My research explored the gazettement processes of three protected areas in the eastern DRC (Itombwe, Kabobo and Okapi Reserves). I focused on the influence of social-political, historical and psychological factors on the management and governance of protected areas in the DRC. In addition, the research reveals the inclusive gazettement processes of protected areas is the foundation of successful co-management approaches. I found that values and good governance practices play a key role in influencing local perceptions and support to conservation interventions. Whilst some conservation practitioners believe that economic benefits to communities are the most predominant motivating factor, I found that good conservation management practices can motivate communities to support protected area management. Bad management practices were related not only to inadequate conservation approaches and practices but also to factors such as corruption, inadequate law enforcement and the inappropriate equipment of rangers. Therefore, I suggest that long term protected area management in DRC should consider how the value of resources for communities and protected areas have been changing throughout the history of conservation, and how to best share power and responsibilities with local resource users and stakeholders. This is only possible if conservation practices and approaches, governance process and institutions are transformed at multiple levels.
- Full Text:
- Date Issued: 2020
Contradictions in womxn’s experiences of pre-abortion counselling in South Africa: Implications for client‐centred practice
- Mavuso, Jabulile M-J J, Macleod, Catriona I
- Authors: Mavuso, Jabulile M-J J , Macleod, Catriona I
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443638 , vital:74140 , xlink:href="https://doi.org/10.1111/nin.12330"
- Description: Pre-abortion counselling may play a key role in abortion seekers’ understanding of their decision to terminate a pregnancy and the subsequent emotions that they feel. In this paper, we report on a study conducted in the Eastern Cape province of South Africa concerning womxn's experiences of the pre-abortion counselling offered as part of the implementation of the Choice of Termination Act that governs the provision of legal abortion in the country. Using a narrative-discursive lens, the analysis revealed four micro-narratives in which participants appreciated non-directive and empathic counselling, as well as being provided with information. They also indicated that the counselling was upsetting and hurtful, particularly when providers drew on the awfulisation of abortion discourse to suggest that abortion leads to terrible consequences, and foetal personhood discourse to intimate that terminating the pregnancy is wrong and other alternatives (adoption, parenting) are better. The connection between these broadly positive and negative responses may lie in the dominance of anti-abortion discourses coupled with the powerful positioning of healthcare providers as experts. The attendant disempowerment of clients within the health clinic setting may constrain pregnant people's ability to question such ‘expert’ information. The implications for feminist client-centred pre-abortion counselling are discussed.
- Full Text:
- Date Issued: 2020
- Authors: Mavuso, Jabulile M-J J , Macleod, Catriona I
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443638 , vital:74140 , xlink:href="https://doi.org/10.1111/nin.12330"
- Description: Pre-abortion counselling may play a key role in abortion seekers’ understanding of their decision to terminate a pregnancy and the subsequent emotions that they feel. In this paper, we report on a study conducted in the Eastern Cape province of South Africa concerning womxn's experiences of the pre-abortion counselling offered as part of the implementation of the Choice of Termination Act that governs the provision of legal abortion in the country. Using a narrative-discursive lens, the analysis revealed four micro-narratives in which participants appreciated non-directive and empathic counselling, as well as being provided with information. They also indicated that the counselling was upsetting and hurtful, particularly when providers drew on the awfulisation of abortion discourse to suggest that abortion leads to terrible consequences, and foetal personhood discourse to intimate that terminating the pregnancy is wrong and other alternatives (adoption, parenting) are better. The connection between these broadly positive and negative responses may lie in the dominance of anti-abortion discourses coupled with the powerful positioning of healthcare providers as experts. The attendant disempowerment of clients within the health clinic setting may constrain pregnant people's ability to question such ‘expert’ information. The implications for feminist client-centred pre-abortion counselling are discussed.
- 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