A mathematics teacher's response to a dilemma: 'I'm supposed to teach them in English but they don't understand'
- Robertson, Sally-Ann, Graven, Mellony
- Authors: Robertson, Sally-Ann , Graven, Mellony
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148889 , vital:38783 , https://doi.org/10.4102/sajce.v10i1.800
- Description: English is the dominant language in South African schools although it is the home language for less than 10% of the population. Many schools have yet to embrace the Language in Education Policy’s advocacy of additive bilingualism. This has led to a majority of the country’s children learning and being assessed through a language in which they lack proficiency. This article draws on second language teaching and learning theory to make a case for more systematic support for learners’ second language development and for legitimation of use of home language in mathematics classrooms where a different language is the official medium. The article shares empirical data from a South African Grade 4 mathematics teacher’s classroom to illuminate arguments in favour of additive bilingualism.
- Full Text:
- Date Issued: 2020
- Authors: Robertson, Sally-Ann , Graven, Mellony
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148889 , vital:38783 , https://doi.org/10.4102/sajce.v10i1.800
- Description: English is the dominant language in South African schools although it is the home language for less than 10% of the population. Many schools have yet to embrace the Language in Education Policy’s advocacy of additive bilingualism. This has led to a majority of the country’s children learning and being assessed through a language in which they lack proficiency. This article draws on second language teaching and learning theory to make a case for more systematic support for learners’ second language development and for legitimation of use of home language in mathematics classrooms where a different language is the official medium. The article shares empirical data from a South African Grade 4 mathematics teacher’s classroom to illuminate arguments in favour of additive bilingualism.
- Full Text:
- Date Issued: 2020
A STAT3 of addiction: adipose tissue, adipocytokine signalling and STAT3 as mediators of metabolic remodelling in the tumour microenvironment
- Kadye, Rose, Stoffels, Mihlali, Fanucci, Sidne, Mbanxa, Siso, Prinsloo, Earl
- Authors: Kadye, Rose , Stoffels, Mihlali , Fanucci, Sidne , Mbanxa, Siso , Prinsloo, Earl
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149395 , vital:38846 , https://doi.org/10.3390/cells9041043
- Description: Metabolic remodelling of the tumour microenvironment is a major mechanism by which cancer cells survive and resist treatment. The pro-oncogenic inflammatory cascade released by adipose tissue promotes oncogenic transformation, proliferation, angiogenesis, metastasis and evasion of apoptosis. STAT3 has emerged as an important mediator of metabolic remodelling. As a downstream effector of adipocytokines and cytokines, its canonical and non-canonical activities affect mitochondrial functioning and cancer metabolism. In this review, we examine the central role played by the crosstalk between the transcriptional and mitochondrial roles of STAT3 to promote survival and further oncogenesis within the tumour microenvironment with a particular focus on adipose-breast cancer interactions.
- Full Text:
- Date Issued: 2020
- Authors: Kadye, Rose , Stoffels, Mihlali , Fanucci, Sidne , Mbanxa, Siso , Prinsloo, Earl
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149395 , vital:38846 , https://doi.org/10.3390/cells9041043
- Description: Metabolic remodelling of the tumour microenvironment is a major mechanism by which cancer cells survive and resist treatment. The pro-oncogenic inflammatory cascade released by adipose tissue promotes oncogenic transformation, proliferation, angiogenesis, metastasis and evasion of apoptosis. STAT3 has emerged as an important mediator of metabolic remodelling. As a downstream effector of adipocytokines and cytokines, its canonical and non-canonical activities affect mitochondrial functioning and cancer metabolism. In this review, we examine the central role played by the crosstalk between the transcriptional and mitochondrial roles of STAT3 to promote survival and further oncogenesis within the tumour microenvironment with a particular focus on adipose-breast cancer interactions.
- Full Text:
- Date Issued: 2020
Can fishing tourism contribute to conservation and sustainability via ecotourism?: a case study of the Fishery for Giant African Threadfin Polydactylus quadrifilis on the Kwanza Estuary, Angola
- Butler, Edward C, Childs, Amber-Robyn, Saayman, Andrea, Potts, Warren M
- Authors: Butler, Edward C , Childs, Amber-Robyn , Saayman, Andrea , Potts, Warren M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149253 , vital:38819 , https://doi.org/10.3390/su12104221
- Description: It has been suggested that tourism fisheries can raise the value of landed catch, provide alternative livelihoods for local artisanal fishers and, because recreationally caught fishes are often released, simultaneously conserve stocks. However, for fishing tourism to meet ecotourism standards, sustainable, local economic benefit is imperative. This study aimed to assess the direct economic contribution of the recreational fishery for Polydactylus quadrifilis on the Kwanza Estuary, Angola. The recreational fishery contributed significantly to economic productivity in an otherwise rural area, generating a total revenue (TR) of $236,826 per four-month fishing season.
- Full Text:
- Date Issued: 2020
- Authors: Butler, Edward C , Childs, Amber-Robyn , Saayman, Andrea , Potts, Warren M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149253 , vital:38819 , https://doi.org/10.3390/su12104221
- Description: It has been suggested that tourism fisheries can raise the value of landed catch, provide alternative livelihoods for local artisanal fishers and, because recreationally caught fishes are often released, simultaneously conserve stocks. However, for fishing tourism to meet ecotourism standards, sustainable, local economic benefit is imperative. This study aimed to assess the direct economic contribution of the recreational fishery for Polydactylus quadrifilis on the Kwanza Estuary, Angola. The recreational fishery contributed significantly to economic productivity in an otherwise rural area, generating a total revenue (TR) of $236,826 per four-month fishing season.
- Full Text:
- Date Issued: 2020
Exploring intermolecular contacts in multi-substituted benzaldehyde derivatives: X-ray, Hirshfeld surface and lattice energy analyses
- Hulushe, Siyabonga T, Manyeruke, Meloddy H, Louzada, Marcel, Rigin, Sergei, Hosten, Eric C, Watkins, Gareth M
- Authors: Hulushe, Siyabonga T , Manyeruke, Meloddy H , Louzada, Marcel , Rigin, Sergei , Hosten, Eric C , Watkins, Gareth M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148483 , vital:38743 , DOI: 10.1039/C9RA10752E
- Description: Crystal structures of six benzaldehyde derivatives (1–6) have been determined and their supramolecular networks were established by an X-ray crystallographic study. The study has shown that the compounds are linked by various intermolecular interactions such as weak C–H⋯O hydrogen bonding, and C–H⋯π, π–π and halogen bonding interactions which consolidate and strengthen the formation of these molecular assemblies. The carbonyl group generates diverse synthons in 1–6 via intermolecular C–H⋯O hydrogen bonds. An interplay of C–H⋯O hydrogen bonds, and C–H⋯π and π–π stacking interactions facilitates the formation of multi-dimensional supramolecular networks. Crystal packings in 4 and 5 are further generated by type I halogen⋯halogen bonding interactions. The differences in crystal packing are represented by variation of substitution positions in the compounds. Structure 3 is isomorphous with 4 but there are subtle differences in their crystal packing.
- Full Text:
- Date Issued: 2020
- Authors: Hulushe, Siyabonga T , Manyeruke, Meloddy H , Louzada, Marcel , Rigin, Sergei , Hosten, Eric C , Watkins, Gareth M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148483 , vital:38743 , DOI: 10.1039/C9RA10752E
- Description: Crystal structures of six benzaldehyde derivatives (1–6) have been determined and their supramolecular networks were established by an X-ray crystallographic study. The study has shown that the compounds are linked by various intermolecular interactions such as weak C–H⋯O hydrogen bonding, and C–H⋯π, π–π and halogen bonding interactions which consolidate and strengthen the formation of these molecular assemblies. The carbonyl group generates diverse synthons in 1–6 via intermolecular C–H⋯O hydrogen bonds. An interplay of C–H⋯O hydrogen bonds, and C–H⋯π and π–π stacking interactions facilitates the formation of multi-dimensional supramolecular networks. Crystal packings in 4 and 5 are further generated by type I halogen⋯halogen bonding interactions. The differences in crystal packing are represented by variation of substitution positions in the compounds. Structure 3 is isomorphous with 4 but there are subtle differences in their crystal packing.
- Full Text:
- Date Issued: 2020
First candidates for γ vibrational bands built on the [505] 11/2− neutron orbital in odd-A Dy isotopes:
- Majola, S N T, Sithole, M A, Mdletshe, L, Hartley, D, Timár, J, Nyakó, B M, Allmond, J M, Bark, R A, Beausang, C, Bianco, L, Bucher, T D, Bvumbi, S P, Carpenter, M P, Chiara, C J, Cooper, N, Cullen, D M, Curien, D, Dinoko, T S, Gall, B J P, Garrett, P E, Greenlees, P T, Hirvonen, J, Jakobsson, U, Jones, P M, Julin, R, Juutinen, S, Ketelhut, S, Keswa, B V, Kondev, F G, Korichi, A, Kulp, W D, Lauritsen, T, Lawrie, E A, Makhathini, L, Masiteng, P L, Maqabuka, B, McCutchan, E A, Miller, D, Miller, S, Minkova, A, Msebi, L, Mthembu, S H, Ndayishmiye, J, Nieminen, P, Ngcobo, P Z, Ntshamgase, S S, Orce, J N, Peura, P, Rahkila, P, Redon, N, Riedinger, L L, Riley, M A, Roux, D G, Ruotsalainen, P, Piot, J, Saren, J, Sharpey-Schafer, J F, Scholey, C, Shirinda, O, Simpson, J, Sorri, J, Stefansecu, I, Stolze, S, Uusitalo, J, Wang, X, Werner, V, Wood, J L, Yu, C-H, Zhu, S, Zimba, G
- Authors: Majola, S N T , Sithole, M A , Mdletshe, L , Hartley, D , Timár, J , Nyakó, B M , Allmond, J M , Bark, R A , Beausang, C , Bianco, L , Bucher, T D , Bvumbi, S P , Carpenter, M P , Chiara, C J , Cooper, N , Cullen, D M , Curien, D , Dinoko, T S , Gall, B J P , Garrett, P E , Greenlees, P T , Hirvonen, J , Jakobsson, U , Jones, P M , Julin, R , Juutinen, S , Ketelhut, S , Keswa, B V , Kondev, F G , Korichi, A , Kulp, W D , Lauritsen, T , Lawrie, E A , Makhathini, L , Masiteng, P L , Maqabuka, B , McCutchan, E A , Miller, D , Miller, S , Minkova, A , Msebi, L , Mthembu, S H , Ndayishmiye, J , Nieminen, P , Ngcobo, P Z , Ntshamgase, S S , Orce, J N , Peura, P , Rahkila, P , Redon, N , Riedinger, L L , Riley, M A , Roux, D G , Ruotsalainen, P , Piot, J , Saren, J , Sharpey-Schafer, J F , Scholey, C , Shirinda, O , Simpson, J , Sorri, J , Stefansecu, I , Stolze, S , Uusitalo, J , Wang, X , Werner, V , Wood, J L , Yu, C-H , Zhu, S , Zimba, G
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148827 , vital:38777 , https://0-journals.aps.org.wam.seals.ac.za/prc/abstract/10.1103/PhysRevC.101.044312
- Description: Rotational structures have been measured using the Jurogam II and GAMMASPHERE arrays at low spin following the 155Gd(α,2n)157Dy and 148Nd(12C,5n)155Dy reactions at 25 and 65 MeV, respectively. We report high-K bands, which are conjectured to be the first candidates of a Kπ=2+γ vibrational band, built on the [505]11/2− neutron orbital, in both odd-A155,157Dy isotopes. The coupling of the first excited K=0+ states or the so-called β vibrational bands at 661 and 676 keV in 154Dy and 156Dy to the [505]11/2− orbital, to produce a Kπ=11/2− band, was not observed in both 155Dy and 157Dy, respectively. The implication of these findings on the interpretation of the first excited 0+ states in the core nuclei 154Dy and 156Dy are also discussed.
- Full Text:
- Date Issued: 2020
- Authors: Majola, S N T , Sithole, M A , Mdletshe, L , Hartley, D , Timár, J , Nyakó, B M , Allmond, J M , Bark, R A , Beausang, C , Bianco, L , Bucher, T D , Bvumbi, S P , Carpenter, M P , Chiara, C J , Cooper, N , Cullen, D M , Curien, D , Dinoko, T S , Gall, B J P , Garrett, P E , Greenlees, P T , Hirvonen, J , Jakobsson, U , Jones, P M , Julin, R , Juutinen, S , Ketelhut, S , Keswa, B V , Kondev, F G , Korichi, A , Kulp, W D , Lauritsen, T , Lawrie, E A , Makhathini, L , Masiteng, P L , Maqabuka, B , McCutchan, E A , Miller, D , Miller, S , Minkova, A , Msebi, L , Mthembu, S H , Ndayishmiye, J , Nieminen, P , Ngcobo, P Z , Ntshamgase, S S , Orce, J N , Peura, P , Rahkila, P , Redon, N , Riedinger, L L , Riley, M A , Roux, D G , Ruotsalainen, P , Piot, J , Saren, J , Sharpey-Schafer, J F , Scholey, C , Shirinda, O , Simpson, J , Sorri, J , Stefansecu, I , Stolze, S , Uusitalo, J , Wang, X , Werner, V , Wood, J L , Yu, C-H , Zhu, S , Zimba, G
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148827 , vital:38777 , https://0-journals.aps.org.wam.seals.ac.za/prc/abstract/10.1103/PhysRevC.101.044312
- Description: Rotational structures have been measured using the Jurogam II and GAMMASPHERE arrays at low spin following the 155Gd(α,2n)157Dy and 148Nd(12C,5n)155Dy reactions at 25 and 65 MeV, respectively. We report high-K bands, which are conjectured to be the first candidates of a Kπ=2+γ vibrational band, built on the [505]11/2− neutron orbital, in both odd-A155,157Dy isotopes. The coupling of the first excited K=0+ states or the so-called β vibrational bands at 661 and 676 keV in 154Dy and 156Dy to the [505]11/2− orbital, to produce a Kπ=11/2− band, was not observed in both 155Dy and 157Dy, respectively. The implication of these findings on the interpretation of the first excited 0+ states in the core nuclei 154Dy and 156Dy are also discussed.
- Full Text:
- Date Issued: 2020
Impacts of a trophy hunting ban on private land conservation in South African biodiversity hotspots:
- Parker, Kim, de Vos, Alta, Clements, Hayley S, Biggs, Duan, Biggs, Reinette
- Authors: Parker, Kim , de Vos, Alta , Clements, Hayley S , Biggs, Duan , Biggs, Reinette
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158219 , vital:40163 , https://0-doi.org.wam.seals.ac.za/10.1111/csp2.214
- Description: Private land conservation areas (PLCAs) have become critical for achieving global conservation goals, but we lack understanding of how and when these areas respond to global pressures and opportunities. In southern Africa, where many PLCAs rely on trophy hunting as an income‐generating strategy, a potential ban on trophy hunting locally or abroad holds unknown consequences for the future conservation of these lands. In this study, we investigate the consequences of a potential trophy hunting ban in PLCAs in two biodiversity hotspots in South Africa's Eastern and Western Cape provinces. We used semistructured interviews with PLCA managers and owners to elicit perceived impacts of an internationally imposed trophy hunting ban on conservation activities in PLCAs, and to probe alternative viable land uses.
- Full Text:
- Date Issued: 2020
Impacts of a trophy hunting ban on private land conservation in South African biodiversity hotspots:
- Authors: Parker, Kim , de Vos, Alta , Clements, Hayley S , Biggs, Duan , Biggs, Reinette
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158219 , vital:40163 , https://0-doi.org.wam.seals.ac.za/10.1111/csp2.214
- Description: Private land conservation areas (PLCAs) have become critical for achieving global conservation goals, but we lack understanding of how and when these areas respond to global pressures and opportunities. In southern Africa, where many PLCAs rely on trophy hunting as an income‐generating strategy, a potential ban on trophy hunting locally or abroad holds unknown consequences for the future conservation of these lands. In this study, we investigate the consequences of a potential trophy hunting ban in PLCAs in two biodiversity hotspots in South Africa's Eastern and Western Cape provinces. We used semistructured interviews with PLCA managers and owners to elicit perceived impacts of an internationally imposed trophy hunting ban on conservation activities in PLCAs, and to probe alternative viable land uses.
- Full Text:
- Date Issued: 2020
Implantation, orientation and validation of a commercially produced heart-rate logger for use in a perciform teleost fish:
- Muller, Cuen, Childs, Amber-Robyn, Duncan, Murray I, Skeeles, Michael R, James, Nicola C, Van der Walt, Kerry-Ann, Winkler, Alexander C, Potts, Warren M
- Authors: Muller, Cuen , Childs, Amber-Robyn , Duncan, Murray I , Skeeles, Michael R , James, Nicola C , Van der Walt, Kerry-Ann , Winkler, Alexander C , Potts, Warren M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148494 , vital:38744 , doi.org.wam.seals.ac.za/10.1093/conphys/coaa035
- Description: Quantifying how the heart rate of ectothermic organisms responds to environmental conditions (e.g. water temperature) is important information to quantify their sensitivity to environmental change. Heart rate studies have typically been conducted in lab environments where fish are confined. However, commercially available implantable heart rate biologgers provide the opportunity to study free-swimming fish. Our study aimed to determine the applicability of an implantable device, typically used on fusiform-shaped fish (e.g. salmonids), for a perciform fish where morphology and anatomy prevent ventral incisions normally used on fusiform-shaped fish.
- Full Text:
- Date Issued: 2020
- Authors: Muller, Cuen , Childs, Amber-Robyn , Duncan, Murray I , Skeeles, Michael R , James, Nicola C , Van der Walt, Kerry-Ann , Winkler, Alexander C , Potts, Warren M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148494 , vital:38744 , doi.org.wam.seals.ac.za/10.1093/conphys/coaa035
- Description: Quantifying how the heart rate of ectothermic organisms responds to environmental conditions (e.g. water temperature) is important information to quantify their sensitivity to environmental change. Heart rate studies have typically been conducted in lab environments where fish are confined. However, commercially available implantable heart rate biologgers provide the opportunity to study free-swimming fish. Our study aimed to determine the applicability of an implantable device, typically used on fusiform-shaped fish (e.g. salmonids), for a perciform fish where morphology and anatomy prevent ventral incisions normally used on fusiform-shaped fish.
- Full Text:
- Date Issued: 2020
Integrated landscape change analysis of protected areas and their surrounding landscapes: application in the Brazilian Cerrado
- Bellón, Beatriz, Blanco, Julien, de Vos, Alta, de Oliviera Roque, Fabio, Pays, Olivier, Renaud, Pierre-Cyril
- Authors: Bellón, Beatriz , Blanco, Julien , de Vos, Alta , de Oliviera Roque, Fabio , Pays, Olivier , Renaud, Pierre-Cyril
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148681 , vital:38763 , https://doi.org/10.3390/rs12091413
- Description: Remote sensing tools have been long used to monitor landscape dynamics inside and around protected areas. Hereto, scientists have largely relied on land use and land cover (LULC) data to derive indicators for monitoring these dynamics, but these metrics do not capture changes in the state of vegetation surfaces that may compromise the ecological integrity of conservation areas’ landscapes. Here, we introduce a methodology that combines LULC change estimates with three Normalized Difference Vegetation Index-based proxy indicators of vegetation productivity, phenology, and structural change. We illustrate the utility of this methodology through a regional and local analysis of the landscape dynamics in the Cerrado Biome in Brazil in 2001 and 2016. Despite relatively little natural vegetation loss inside core protected areas and their legal buffer zones, the different indicators revealed significant LULC conversions from natural vegetation to farming land, general productivity loss, homogenization of natural forests, significant agricultural expansion, and a general increase in productivity. These results suggest an overall degradation of habitats and intensification of land use in the studied conservation area network, highlighting serious conservation inefficiencies in this region and stressing the importance of integrated landscape change analyses to provide complementary indicators of ecologically-relevant dynamics in these key conservation areas.
- Full Text:
- Date Issued: 2020
- Authors: Bellón, Beatriz , Blanco, Julien , de Vos, Alta , de Oliviera Roque, Fabio , Pays, Olivier , Renaud, Pierre-Cyril
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148681 , vital:38763 , https://doi.org/10.3390/rs12091413
- Description: Remote sensing tools have been long used to monitor landscape dynamics inside and around protected areas. Hereto, scientists have largely relied on land use and land cover (LULC) data to derive indicators for monitoring these dynamics, but these metrics do not capture changes in the state of vegetation surfaces that may compromise the ecological integrity of conservation areas’ landscapes. Here, we introduce a methodology that combines LULC change estimates with three Normalized Difference Vegetation Index-based proxy indicators of vegetation productivity, phenology, and structural change. We illustrate the utility of this methodology through a regional and local analysis of the landscape dynamics in the Cerrado Biome in Brazil in 2001 and 2016. Despite relatively little natural vegetation loss inside core protected areas and their legal buffer zones, the different indicators revealed significant LULC conversions from natural vegetation to farming land, general productivity loss, homogenization of natural forests, significant agricultural expansion, and a general increase in productivity. These results suggest an overall degradation of habitats and intensification of land use in the studied conservation area network, highlighting serious conservation inefficiencies in this region and stressing the importance of integrated landscape change analyses to provide complementary indicators of ecologically-relevant dynamics in these key conservation areas.
- Full Text:
- Date Issued: 2020
Mapping subtidal estuarine habitats with a remotely operated underwater vehicle (ROV):
- Wasserman, J, Claassens, Louw, Adams, J B
- Authors: Wasserman, J , Claassens, Louw , Adams, J B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150163 , vital:38945 , DOI: 10.2989/1814232X.2020.1731598
- Description: Subtidal habitats have not yet been accounted for in habitat maps of South African estuaries. In this study, a novel method for mapping subtidal estuarine habitats, using a remotely operated underwater vehicle (ROV) piloted from a boat, was developed and tested in the Knysna Estuary. Video footage was recorded along 48 transects across the width of the estuary, and then reviewed to identify, classify and map habitats. Using the method developed in this study, 21 hours of footage was recorded over 15 days of sampling, and about 30 hours of post-processing was carried out to map an area exceeding 850 ha. This study has produced the first baseline dataset of subtidal habitats for a South African estuary. Additionally, the study revealed the previously unknown distribution of the invasive red seaweed Asparagopsis taxiformis, and the underestimation in previous studies of the estuary of area cover of eelgrass Zostera capensis by 130 ha.
- Full Text:
- Date Issued: 2020
- Authors: Wasserman, J , Claassens, Louw , Adams, J B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150163 , vital:38945 , DOI: 10.2989/1814232X.2020.1731598
- Description: Subtidal habitats have not yet been accounted for in habitat maps of South African estuaries. In this study, a novel method for mapping subtidal estuarine habitats, using a remotely operated underwater vehicle (ROV) piloted from a boat, was developed and tested in the Knysna Estuary. Video footage was recorded along 48 transects across the width of the estuary, and then reviewed to identify, classify and map habitats. Using the method developed in this study, 21 hours of footage was recorded over 15 days of sampling, and about 30 hours of post-processing was carried out to map an area exceeding 850 ha. This study has produced the first baseline dataset of subtidal habitats for a South African estuary. Additionally, the study revealed the previously unknown distribution of the invasive red seaweed Asparagopsis taxiformis, and the underestimation in previous studies of the estuary of area cover of eelgrass Zostera capensis by 130 ha.
- Full Text:
- Date Issued: 2020
Post-release monitoring in classical biological control of weeds: higher trophic levels modify competitive interactions between invasive macrophytes
- Schaffner, Urs, Hill, Martin P, Dudley, Tom, D’Antonio, Carla
- Authors: Schaffner, Urs , Hill, Martin P , Dudley, Tom , D’Antonio, Carla
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150200 , vital:38949 , https://doi.org/10.1016/j.cois.2020.02.008
- Description: While various aspects of classical biological control (CBC) of weeds, including non-target risk assessment, have been continuously improved in the past few decades, post-release monitoring remains neglected and underfunded. Detailed assessments of the population, community and ecosystem outcomes of CBC introductions, including reasons for success/failure and absence or evidence of non-target effects are generally lacking or fragmentary. Here we review recent advances in understanding the demography of biological control agents released into a novel environment, their impact on the target weed and on non-target species, and the consequences for the resident plant and animal communities and ecosystem functioning, including the restoration of ecosystem services. We argue that post-release monitoring of CBC programs offers unique but largely underutilized opportunities to improve our understanding of CBC outcomes and to inform management and decision-makers on when and how CBC should be integrated with other management options to enhance ecosystem restoration.
- Full Text:
- Date Issued: 2020
- Authors: Schaffner, Urs , Hill, Martin P , Dudley, Tom , D’Antonio, Carla
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150200 , vital:38949 , https://doi.org/10.1016/j.cois.2020.02.008
- Description: While various aspects of classical biological control (CBC) of weeds, including non-target risk assessment, have been continuously improved in the past few decades, post-release monitoring remains neglected and underfunded. Detailed assessments of the population, community and ecosystem outcomes of CBC introductions, including reasons for success/failure and absence or evidence of non-target effects are generally lacking or fragmentary. Here we review recent advances in understanding the demography of biological control agents released into a novel environment, their impact on the target weed and on non-target species, and the consequences for the resident plant and animal communities and ecosystem functioning, including the restoration of ecosystem services. We argue that post-release monitoring of CBC programs offers unique but largely underutilized opportunities to improve our understanding of CBC outcomes and to inform management and decision-makers on when and how CBC should be integrated with other management options to enhance ecosystem restoration.
- Full Text:
- Date Issued: 2020
Predicting non-target impacts:
- Paynter, Quentin, Paterson, Iain D, Kwong, Raelene M
- Authors: Paynter, Quentin , Paterson, Iain D , Kwong, Raelene M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149982 , vital:38921 , https://doi.org/10.1016/j.cois.2020.02.002
- Description: Biocontrol of invasive alien weeds has produced great benefits, but concerns over undesirable impacts on non-target plants and/or indirect interactions between biocontrol agents and other biota impede the implementation of biocontrol in some countries. Although great strides have been made, continuing uncertainties predicting the realized host range of candidate agents is probably resulting in some being erroneously rejected due to overestimation of risk. Further refinement of host-range testing protocols is therefore desirable. Indirect interactions are inherently harder to predict, and the risk of both direct and indirect non-target impacts may change over time due to biocontrol agents evolving or expanding their range under climate change. Future research directions to better understand the risk of non-target impacts over time are discussed.
- Full Text:
- Date Issued: 2020
- Authors: Paynter, Quentin , Paterson, Iain D , Kwong, Raelene M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149982 , vital:38921 , https://doi.org/10.1016/j.cois.2020.02.002
- Description: Biocontrol of invasive alien weeds has produced great benefits, but concerns over undesirable impacts on non-target plants and/or indirect interactions between biocontrol agents and other biota impede the implementation of biocontrol in some countries. Although great strides have been made, continuing uncertainties predicting the realized host range of candidate agents is probably resulting in some being erroneously rejected due to overestimation of risk. Further refinement of host-range testing protocols is therefore desirable. Indirect interactions are inherently harder to predict, and the risk of both direct and indirect non-target impacts may change over time due to biocontrol agents evolving or expanding their range under climate change. Future research directions to better understand the risk of non-target impacts over time are discussed.
- Full Text:
- Date Issued: 2020
Structural Characterization of Carbonic Anhydrase VIII and Effects of Missense Single Nucleotide Variations to Protein Structure and Function:
- Sanyanga, Taremekedzwa Allan, Tastan Bishop, Özlem
- Authors: Sanyanga, Taremekedzwa Allan , Tastan Bishop, Özlem
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149670 , vital:38873 , https://doi.org/10.3390/ijms21082764
- Description: Human carbonic anhydrase 8 (CA-VIII) is an acatalytic isoform of the α -CA family. Though the protein cannot hydrate CO2, CA-VIII is essential for calcium (Ca2+) homeostasis within the body, and achieves this by allosterically inhibiting the binding of inositol 1,4,5-triphosphate (IP3) to the IP3 receptor type 1 (ITPR1) protein. However, the mechanism of interaction of CA-VIII to ITPR1 is not well understood. In addition, functional defects to CA-VIII due to non-synonymous single nucleotide polymorphisms (nsSNVs) result in Ca2+ dysregulation and the development of the phenotypes such as cerebellar ataxia, mental retardation and disequilibrium syndrome 3 (CAMRQ3). The pathogenesis of CAMRQ3 is also not well understood. The structure and function of CA-VIII was characterised, and pathogenesis of CAMRQ3 investigated. Structural and functional characterisation of CA-VIII was conducted through SiteMap and CPORT to identify potential binding site residues.
- Full Text:
- Date Issued: 2020
- Authors: Sanyanga, Taremekedzwa Allan , Tastan Bishop, Özlem
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149670 , vital:38873 , https://doi.org/10.3390/ijms21082764
- Description: Human carbonic anhydrase 8 (CA-VIII) is an acatalytic isoform of the α -CA family. Though the protein cannot hydrate CO2, CA-VIII is essential for calcium (Ca2+) homeostasis within the body, and achieves this by allosterically inhibiting the binding of inositol 1,4,5-triphosphate (IP3) to the IP3 receptor type 1 (ITPR1) protein. However, the mechanism of interaction of CA-VIII to ITPR1 is not well understood. In addition, functional defects to CA-VIII due to non-synonymous single nucleotide polymorphisms (nsSNVs) result in Ca2+ dysregulation and the development of the phenotypes such as cerebellar ataxia, mental retardation and disequilibrium syndrome 3 (CAMRQ3). The pathogenesis of CAMRQ3 is also not well understood. The structure and function of CA-VIII was characterised, and pathogenesis of CAMRQ3 investigated. Structural and functional characterisation of CA-VIII was conducted through SiteMap and CPORT to identify potential binding site residues.
- Full Text:
- Date Issued: 2020
Synthesis, structure and in vitro anti-trypanosomal activity of non-toxic Arylpyrrole-Based Chalcone derivatives:
- Zulu, Ayanda I, Oderinlo, Ogunyemi O, Kruger, Cuan, Isaacs, Michelle, Hoppe, Heinrich C, Smith, Vincent J, Veale, Clinton G L, Khanye, Setshaba D
- Authors: Zulu, Ayanda I , Oderinlo, Ogunyemi O , Kruger, Cuan , Isaacs, Michelle , Hoppe, Heinrich C , Smith, Vincent J , Veale, Clinton G L , Khanye, Setshaba D
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179017 , vital:40096 , https://doi.org/10.3390/molecules25071668
- Description: With an intention of identifying chalcone derivatives exhibiting anti-protozoal activity, a cohort of relatively unexplored arylpyrrole-based chalcone derivatives were synthesized in moderate to good yields. The resultant compounds were evaluated in vitro for their potential activity against a cultured Trypanosoma brucei brucei 427 strain. Several compounds displayed mostly modest in vitro anti-trypanosomal activity with compounds 10e and 10h emerging as active candidates with IC50 values of 4.09 and 5.11 µM, respectively. More importantly, a concomitant assessment of their activity against a human cervix adenocarcinoma (HeLa) cell line revealed that these compounds are non-toxic.
- Full Text:
- Date Issued: 2020
- Authors: Zulu, Ayanda I , Oderinlo, Ogunyemi O , Kruger, Cuan , Isaacs, Michelle , Hoppe, Heinrich C , Smith, Vincent J , Veale, Clinton G L , Khanye, Setshaba D
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/179017 , vital:40096 , https://doi.org/10.3390/molecules25071668
- Description: With an intention of identifying chalcone derivatives exhibiting anti-protozoal activity, a cohort of relatively unexplored arylpyrrole-based chalcone derivatives were synthesized in moderate to good yields. The resultant compounds were evaluated in vitro for their potential activity against a cultured Trypanosoma brucei brucei 427 strain. Several compounds displayed mostly modest in vitro anti-trypanosomal activity with compounds 10e and 10h emerging as active candidates with IC50 values of 4.09 and 5.11 µM, respectively. More importantly, a concomitant assessment of their activity against a human cervix adenocarcinoma (HeLa) cell line revealed that these compounds are non-toxic.
- Full Text:
- Date Issued: 2020
The in vitro antiplasmodial and antiproliferative activity of new ferrocene-based α-aminocresols targeting hemozoin inhibition and DNA interaction:
- Mbaba, Mziyanda, Dingle, Laura M K, Swart, Tarryn, Cash, Devon, Laming, Dustin, de la Mare, Jo-Anne, Taylor, Dale, Hoppe, Heinrich C, Biot, Christophe, Edkins, Adrienne L, Khanye, Setshaba D
- Authors: Mbaba, Mziyanda , Dingle, Laura M K , Swart, Tarryn , Cash, Devon , Laming, Dustin , de la Mare, Jo-Anne , Taylor, Dale , Hoppe, Heinrich C , Biot, Christophe , Edkins, Adrienne L , Khanye, Setshaba D
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149347 , vital:38827 , https://0-doi.org.wam.seals.ac.za/10.1002/cbic.202000132
- Description: Compounds incorporating ferrocene in a aminocresol scaffold showed antiplasmodial and anticancer activity. SAR studies revealed that an OH group and rotatable C–NH bond are vital for biological activity, with spectrophotometric techniques and docking simulations suggesting a dual mode of action involving hemozoin inhibition and DNA interaction. Targeting multiple pathways could delay the development of clinical resistance.
- Full Text:
- Date Issued: 2020
- Authors: Mbaba, Mziyanda , Dingle, Laura M K , Swart, Tarryn , Cash, Devon , Laming, Dustin , de la Mare, Jo-Anne , Taylor, Dale , Hoppe, Heinrich C , Biot, Christophe , Edkins, Adrienne L , Khanye, Setshaba D
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149347 , vital:38827 , https://0-doi.org.wam.seals.ac.za/10.1002/cbic.202000132
- Description: Compounds incorporating ferrocene in a aminocresol scaffold showed antiplasmodial and anticancer activity. SAR studies revealed that an OH group and rotatable C–NH bond are vital for biological activity, with spectrophotometric techniques and docking simulations suggesting a dual mode of action involving hemozoin inhibition and DNA interaction. Targeting multiple pathways could delay the development of clinical resistance.
- Full Text:
- Date Issued: 2020
The Thousand-Pulsar-Array programme on MeerKAT–I: science objectives and first results
- Johnston, Simon, Karastergiou, A, Keith, M J, Song, X, Weltevrede, P, Abbate, F, Bailes, M, Buchner, S, Camilo, F, Geyer, M, Hugo, B, Jameson, A, Kramer, M, Parthasarathy, A, Reardon, D J, Ridolfi A, Serylak, M, Shannon, R M, Spiewak, R, Van Straten, W, Venkatraman Krishnan, V, Jankowski, F, Meyers, B W, Oswald , L, Posselt, B, Sobey, C, Szary, A, Van Leeuwen, J
- Authors: Johnston, Simon , Karastergiou, A , Keith, M J , Song, X , Weltevrede, P , Abbate, F , Bailes, M , Buchner, S , Camilo, F , Geyer, M , Hugo, B , Jameson, A , Kramer, M , Parthasarathy, A , Reardon, D J , Ridolfi A , Serylak, M , Shannon, R M , Spiewak, R , Van Straten, W , Venkatraman Krishnan, V , Jankowski, F , Meyers, B W , Oswald , L , Posselt, B , Sobey, C , Szary, A , Van Leeuwen, J
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148814 , vital:38776 , https://0-doi.org.wam.seals.ac.za/10.1093/mnras/staa516
- Description: We report here on initial results from the Thousand-Pulsar-Array (TPA) programme, part of the Large Survey Project ‘MeerTime’ on the MeerKAT telescope. The interferometer is used in the tied-array mode in the band from 856 to 1712 MHz, and the wide band coupled with the large collecting area and low receiver temperature make it an excellent telescope for the study of radio pulsars. The TPA is a 5 year project, which aims at to observing (a) more than 1000 pulsars to obtain high-fidelity pulse profiles, (b) some 500 of these pulsars over multiple epochs, and (c) long sequences of single-pulse trains from several hundred pulsars.
- Full Text:
- Date Issued: 2020
- Authors: Johnston, Simon , Karastergiou, A , Keith, M J , Song, X , Weltevrede, P , Abbate, F , Bailes, M , Buchner, S , Camilo, F , Geyer, M , Hugo, B , Jameson, A , Kramer, M , Parthasarathy, A , Reardon, D J , Ridolfi A , Serylak, M , Shannon, R M , Spiewak, R , Van Straten, W , Venkatraman Krishnan, V , Jankowski, F , Meyers, B W , Oswald , L , Posselt, B , Sobey, C , Szary, A , Van Leeuwen, J
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148814 , vital:38776 , https://0-doi.org.wam.seals.ac.za/10.1093/mnras/staa516
- Description: We report here on initial results from the Thousand-Pulsar-Array (TPA) programme, part of the Large Survey Project ‘MeerTime’ on the MeerKAT telescope. The interferometer is used in the tied-array mode in the band from 856 to 1712 MHz, and the wide band coupled with the large collecting area and low receiver temperature make it an excellent telescope for the study of radio pulsars. The TPA is a 5 year project, which aims at to observing (a) more than 1000 pulsars to obtain high-fidelity pulse profiles, (b) some 500 of these pulsars over multiple epochs, and (c) long sequences of single-pulse trains from several hundred pulsars.
- Full Text:
- Date Issued: 2020
Urban foraging: land management policy, perspectives, and potential
- Sardeshpande, Mallika, Shackleton, Charlie M
- Authors: Sardeshpande, Mallika , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149384 , vital:38845 , https://0-doi.org.wam.seals.ac.za/10.1371/journal.pone.0230693
- Description: Gathering of uncultivated food from green spaces, also known as foraging, is observed in urban areas across the world, but the literature focuses predominantly on the global north. Our study examines the existing urban land management structure and its approach to urban foraging in the eastern coastal region of South Africa. Through interviews with municipal officials in nine cities, we identified different stakeholders and their roles in urban green space management. We then used network analysis to represent interactions and influence of these stakeholders, and environmental worldviews to determine organisational and perceptual barriers to and enablers of foraging in urban green spaces. The policy on urban green space management, as well as land managers themselves are amenable to the concept of foraging in public spaces. Lack of knowledge on wild indigenous species and sustainable offtake, ambiguous, coarse, or lacking policy, and normative views of pristine nature may hinder foraging. We recommend pathways for policy and stakeholder partnerships to incorporate sustainable foraging in their biodiversity conservation and land stewardship strategies.
- Full Text:
- Date Issued: 2020
- Authors: Sardeshpande, Mallika , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149384 , vital:38845 , https://0-doi.org.wam.seals.ac.za/10.1371/journal.pone.0230693
- Description: Gathering of uncultivated food from green spaces, also known as foraging, is observed in urban areas across the world, but the literature focuses predominantly on the global north. Our study examines the existing urban land management structure and its approach to urban foraging in the eastern coastal region of South Africa. Through interviews with municipal officials in nine cities, we identified different stakeholders and their roles in urban green space management. We then used network analysis to represent interactions and influence of these stakeholders, and environmental worldviews to determine organisational and perceptual barriers to and enablers of foraging in urban green spaces. The policy on urban green space management, as well as land managers themselves are amenable to the concept of foraging in public spaces. Lack of knowledge on wild indigenous species and sustainable offtake, ambiguous, coarse, or lacking policy, and normative views of pristine nature may hinder foraging. We recommend pathways for policy and stakeholder partnerships to incorporate sustainable foraging in their biodiversity conservation and land stewardship strategies.
- Full Text:
- Date Issued: 2020
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