A comparison of three models used to determine water fluxes over the Albany Thicket, Eastern Cape, South Africa:
- Palmer, Anthony R, Ezenne, G I, Choruma, D J, Gwate, O, Mantel, Sukhmani K, Tanner, Jane L
- Authors: Palmer, Anthony R , Ezenne, G I , Choruma, D J , Gwate, O , Mantel, Sukhmani K , Tanner, Jane L
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150047 , vital:38934 , https://doi.org/10.1016/j.agrformet.2020.107984
- Description: The Albany Thicket (AT) biome contains outstanding global biodiversity as well as the potential to achieve carbon credits associated with water-efficient Crasslucean acid metabolism (CAM). Understanding the water fluxes in the AT is crucial to determining carbon (C) sequestration rates and water-use efficiency. Despite large variation in water fluxes across the AT, only a few studies have been conducted in this region with their results validated against short periods of observed data. This study aims to evaluate three models of water fluxes over AT against data from an eddy covariance (EC) system active from October 2015 to May 2018. ET was modelled using the BioGeoChemistry Management (BGC-MAN) model, a biophysical model (Penman-Monteith-Leuning (PML)) and a remotely-sensed product (MOD16), and their results compared with that from the EC system.
- Full Text:
- Date Issued: 2020
- Authors: Palmer, Anthony R , Ezenne, G I , Choruma, D J , Gwate, O , Mantel, Sukhmani K , Tanner, Jane L
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150047 , vital:38934 , https://doi.org/10.1016/j.agrformet.2020.107984
- Description: The Albany Thicket (AT) biome contains outstanding global biodiversity as well as the potential to achieve carbon credits associated with water-efficient Crasslucean acid metabolism (CAM). Understanding the water fluxes in the AT is crucial to determining carbon (C) sequestration rates and water-use efficiency. Despite large variation in water fluxes across the AT, only a few studies have been conducted in this region with their results validated against short periods of observed data. This study aims to evaluate three models of water fluxes over AT against data from an eddy covariance (EC) system active from October 2015 to May 2018. ET was modelled using the BioGeoChemistry Management (BGC-MAN) model, a biophysical model (Penman-Monteith-Leuning (PML)) and a remotely-sensed product (MOD16), and their results compared with that from the EC system.
- Full Text:
- Date Issued: 2020
Alignment in the orientation of LOFAR radio sources:
- Osinga, E, Miley, G K, van Weeren, R J, Shimwell, T W, Duncan, K J, Hardcastle, M J, Mechev, A P, Röttgering, H J A, Tasse, C, Williams, W L
- Authors: Osinga, E , Miley, G K , van Weeren, R J , Shimwell, T W , Duncan, K J , Hardcastle, M J , Mechev, A P , Röttgering, H J A , Tasse, C , Williams, W L
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163452 , vital:41039 , https://doi.org/10.1051/0004-6361/202037680
- Description: Various studies have laid claim to finding an alignment of the polarization vectors or radio jets of active galactic nuclei over large distances, but these results have proven controversial and so far, there is no clear explanation for this observed alignment. To investigate this case further, we tested the hypothesis that the position angles of radio galaxies are randomly oriented in the sky by using data from the Low-Frequency Array (LOFAR) Two-metre Sky Survey (LoTSS). A sample of 7555 double-lobed radio galaxies was extracted from the list of 318 520 radio sources in the first data release of LoTSS at 150 MHz. We performed statistical tests for uniformity of the two-dimensional (2D) orientations for the complete 7555 source sample. We also tested the orientation uniformity in three dimensions (3D) for the 4212 source sub-sample with photometric or spectroscopic redshifts.
- Full Text:
- Date Issued: 2020
- Authors: Osinga, E , Miley, G K , van Weeren, R J , Shimwell, T W , Duncan, K J , Hardcastle, M J , Mechev, A P , Röttgering, H J A , Tasse, C , Williams, W L
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163452 , vital:41039 , https://doi.org/10.1051/0004-6361/202037680
- Description: Various studies have laid claim to finding an alignment of the polarization vectors or radio jets of active galactic nuclei over large distances, but these results have proven controversial and so far, there is no clear explanation for this observed alignment. To investigate this case further, we tested the hypothesis that the position angles of radio galaxies are randomly oriented in the sky by using data from the Low-Frequency Array (LOFAR) Two-metre Sky Survey (LoTSS). A sample of 7555 double-lobed radio galaxies was extracted from the list of 318 520 radio sources in the first data release of LoTSS at 150 MHz. We performed statistical tests for uniformity of the two-dimensional (2D) orientations for the complete 7555 source sample. We also tested the orientation uniformity in three dimensions (3D) for the 4212 source sub-sample with photometric or spectroscopic redshifts.
- Full Text:
- Date Issued: 2020
Environment and sustainability education research as policy engagement: (re-) invigorating ‘politics as potentia’ in South Africa
- Lotz-Sisitka, Heila, Rosenberg, Eureta, Ramsarup, Presha
- Authors: Lotz-Sisitka, Heila , Rosenberg, Eureta , Ramsarup, Presha
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158230 , vital:40164 , https://0-doi.org.wam.seals.ac.za/10.1080/13504622.2020.1759511
- Description: Using a meta-review approach organized historically in relation to critical policy incidents, this paper critically reviews the process of developing and (re) invigorating Environment and Sustainability Education (ESE) (policy) research as ESE policy engagement over a 30+ year period in a rapidly transforming society, South Africa. It offers an example of long term policy-research meta-review in a context of policy flux. It adds to a body of international ESE policy studies that are seeking to understand and develop the ESE research/policy interface as this relation emerges under more complex conditions. In particular, we respond to the finding in the systematic review of ESE policy research undertaken by Aikens, McKenzie and Vaughter (2016) which reports a geographic under-representation of Africa (amongst other places) in ESE policy studies, and González-Gaudiano (2016, 118)’s insight that ESE policy research in current neo-liberally dominated political conditions and as political process, is essentially an “open, unsteady, incomplete, and relational process”.
- Full Text:
- Date Issued: 2020
- Authors: Lotz-Sisitka, Heila , Rosenberg, Eureta , Ramsarup, Presha
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158230 , vital:40164 , https://0-doi.org.wam.seals.ac.za/10.1080/13504622.2020.1759511
- Description: Using a meta-review approach organized historically in relation to critical policy incidents, this paper critically reviews the process of developing and (re) invigorating Environment and Sustainability Education (ESE) (policy) research as ESE policy engagement over a 30+ year period in a rapidly transforming society, South Africa. It offers an example of long term policy-research meta-review in a context of policy flux. It adds to a body of international ESE policy studies that are seeking to understand and develop the ESE research/policy interface as this relation emerges under more complex conditions. In particular, we respond to the finding in the systematic review of ESE policy research undertaken by Aikens, McKenzie and Vaughter (2016) which reports a geographic under-representation of Africa (amongst other places) in ESE policy studies, and González-Gaudiano (2016, 118)’s insight that ESE policy research in current neo-liberally dominated political conditions and as political process, is essentially an “open, unsteady, incomplete, and relational process”.
- Full Text:
- Date Issued: 2020
Evidence of genetic differentiation in cigar wrasse Cheilio inermis (Labridae) within the western Indian Ocean:
- Mayekiso, Sisanda, Gouws, Gavin, Mwale, Monica, Gon, Ofer
- Authors: Mayekiso, Sisanda , Gouws, Gavin , Mwale, Monica , Gon, Ofer
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163499 , vital:41043 , https://doi.org/10.1139/gen-2019-0185
- Description: Patterns of genetic structure and connectivity of the monotypic cigar wrasse Cheilio inermis within western Indian Ocean (WIO) are poorly understood. Whether the species exists as a single panmictic population across the WIO is unclear. Sequence data were generated from two mitochondrial genes (cytochrome b and ATPase 6) and one nuclear intron (S7 intron I). High levels of haplotype and allelic diversity (h = 0.88–0.98; A = 0.95–0.98), along with low nucleotide diversities were observed across all markers.
- Full Text:
- Date Issued: 2020
- Authors: Mayekiso, Sisanda , Gouws, Gavin , Mwale, Monica , Gon, Ofer
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163499 , vital:41043 , https://doi.org/10.1139/gen-2019-0185
- Description: Patterns of genetic structure and connectivity of the monotypic cigar wrasse Cheilio inermis within western Indian Ocean (WIO) are poorly understood. Whether the species exists as a single panmictic population across the WIO is unclear. Sequence data were generated from two mitochondrial genes (cytochrome b and ATPase 6) and one nuclear intron (S7 intron I). High levels of haplotype and allelic diversity (h = 0.88–0.98; A = 0.95–0.98), along with low nucleotide diversities were observed across all markers.
- Full Text:
- Date Issued: 2020
Geotourism, iconic landforms and island-style speciation patterns in National Parks of East Africa:
- Authors: Scoon, Roger N
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158252 , vital:40166 , https://0-doi.org.wam.seals.ac.za/10.1007/s12371-020-00486-z
- Description: Many of the national parks in East Africa are equally as famous for their iconic landforms as they are for their diversity and concentrations of fauna and flora. The newly formed Ngorongoro-Lengai Geopark in northern Tanzania is the first geopark to be established in the region, but there is remarkable potential for geotourism in the majority of the national parks. The most spectacular landforms have been shaped by the East African Rift System. Formation of the two major rifts in the region, the Albertine Rift (or western branch) and the Gregory Rift (or eastern branch), was accompanied, or in some cases preceded, by extensive alkaline volcanism. The rifting and volcanism are primarily Late Cenozoic phenomenon that dissected and overprinted the older regional plateaus. Rifting impacted the regional drainage and captured major rivers, including the Victoria Nile.
- Full Text:
- Date Issued: 2020
- Authors: Scoon, Roger N
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158252 , vital:40166 , https://0-doi.org.wam.seals.ac.za/10.1007/s12371-020-00486-z
- Description: Many of the national parks in East Africa are equally as famous for their iconic landforms as they are for their diversity and concentrations of fauna and flora. The newly formed Ngorongoro-Lengai Geopark in northern Tanzania is the first geopark to be established in the region, but there is remarkable potential for geotourism in the majority of the national parks. The most spectacular landforms have been shaped by the East African Rift System. Formation of the two major rifts in the region, the Albertine Rift (or western branch) and the Gregory Rift (or eastern branch), was accompanied, or in some cases preceded, by extensive alkaline volcanism. The rifting and volcanism are primarily Late Cenozoic phenomenon that dissected and overprinted the older regional plateaus. Rifting impacted the regional drainage and captured major rivers, including the Victoria Nile.
- Full Text:
- Date Issued: 2020
Nutrient release dynamics associated with native and invasive leaf litter decomposition: a Mesocosm Experiment
- Mutshekwa, Thendo, Cuthbert, Ross N, Wasserman, Ryan J, Murungweni, Florence M, Dalu, Tatenda
- Authors: Mutshekwa, Thendo , Cuthbert, Ross N , Wasserman, Ryan J , Murungweni, Florence M , Dalu, Tatenda
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160467 , vital:40448 , https://doi.org/10.3390/w12092350
- Description: Leaf litter contributes to the functioning of aquatic ecosystems through allochthonous inputs of carbon, nitrogen, and other elements. Here, we examine leaf litter nutrient inputs and decomposition associated with four plant species using a mesocosm approach. Native sycamore fig Ficus sycomorus L., and silver cluster–leaf Terminalia sericea Burch. ex DC. decomposition dynamics were compared to invasive tickberry Lantana camara L. and guava Psidium guajava L., whereby phosphate, nitrate, nitrite, silicate, and ammonium releases were quantified over time. Leaf inputs significantly reduced pH, with reductions most marked by invasive L. camara. Conductivity was heightened by all leaf input treatments, except native T. sericea.
- Full Text:
- Date Issued: 2020
- Authors: Mutshekwa, Thendo , Cuthbert, Ross N , Wasserman, Ryan J , Murungweni, Florence M , Dalu, Tatenda
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160467 , vital:40448 , https://doi.org/10.3390/w12092350
- Description: Leaf litter contributes to the functioning of aquatic ecosystems through allochthonous inputs of carbon, nitrogen, and other elements. Here, we examine leaf litter nutrient inputs and decomposition associated with four plant species using a mesocosm approach. Native sycamore fig Ficus sycomorus L., and silver cluster–leaf Terminalia sericea Burch. ex DC. decomposition dynamics were compared to invasive tickberry Lantana camara L. and guava Psidium guajava L., whereby phosphate, nitrate, nitrite, silicate, and ammonium releases were quantified over time. Leaf inputs significantly reduced pH, with reductions most marked by invasive L. camara. Conductivity was heightened by all leaf input treatments, except native T. sericea.
- Full Text:
- Date Issued: 2020
Synthetic, characterization and cytotoxic studies of ruthenium complexes with Schiff bases encompassing biologically relevant moieties:
- Maikoo, Sanam, Dingle, Laura M K, Chakraborty, Abir, Xulu, Bheki, Edkins, Adrienne L, Booysen, Irvin N
- Authors: Maikoo, Sanam , Dingle, Laura M K , Chakraborty, Abir , Xulu, Bheki , Edkins, Adrienne L , Booysen, Irvin N
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165429 , vital:41243 , https://doi.org/10.1016/j.poly.2020.114569
- Description: This research study describes the formation and characterization of novel paramagnetic ruthenium complexes, cis-Cl, trans-P-[RuIIICl2(carboim)(PPh3)2] with bidentate chelating carbohydrazide Schiff bases (carboim = bpc for 1, ttc for 2 and tpc for 3). These metal complexes were synthesized by the equimolar coordination reactions of trans-[RuCl2(PPh3)2] with N-[1,3-benzothiazole-2-ylmethylidene]pyridine-2-carbohydrazide (Hbpc), N-((uracil-5-yl)methylene)thiophene-2-carbohydrazide (Httc) and N-[(uracil-5-yl)methylidene]pyridine-2-carbohydrazide (Htpc), respectively. Physicochemical techniques including nuclear magnetic resonance-, electron-spin resonance- and infrared spectroscopy, UV–Vis spectrophotometry, voltammetry as well as molar conductivity measurements provided definitive determinations of the respective ruthenium compounds’ structures.
- Full Text:
- Date Issued: 2020
- Authors: Maikoo, Sanam , Dingle, Laura M K , Chakraborty, Abir , Xulu, Bheki , Edkins, Adrienne L , Booysen, Irvin N
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165429 , vital:41243 , https://doi.org/10.1016/j.poly.2020.114569
- Description: This research study describes the formation and characterization of novel paramagnetic ruthenium complexes, cis-Cl, trans-P-[RuIIICl2(carboim)(PPh3)2] with bidentate chelating carbohydrazide Schiff bases (carboim = bpc for 1, ttc for 2 and tpc for 3). These metal complexes were synthesized by the equimolar coordination reactions of trans-[RuCl2(PPh3)2] with N-[1,3-benzothiazole-2-ylmethylidene]pyridine-2-carbohydrazide (Hbpc), N-((uracil-5-yl)methylene)thiophene-2-carbohydrazide (Httc) and N-[(uracil-5-yl)methylidene]pyridine-2-carbohydrazide (Htpc), respectively. Physicochemical techniques including nuclear magnetic resonance-, electron-spin resonance- and infrared spectroscopy, UV–Vis spectrophotometry, voltammetry as well as molar conductivity measurements provided definitive determinations of the respective ruthenium compounds’ structures.
- Full Text:
- Date Issued: 2020
The alternative theory of state-minded protest texts in the music of democratic Nigeria:
- Authors: Osiebe, Garhe
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160423 , vital:40444 , DOI: 10.1080/21681392.2020.1810085
- Description: This paper centres on an alternative discourse of popular music culture in re-democratized Nigeria. Whereas much work has been done on state-minded protest music in Nigeria, studies have been reticent in appreciating the works of Fela's son, Femi; particularly within a framework of re-democratized Nigeria's equivalent of Fela's works which constituted a major alternative voice through military-ruled Nigeria. The paper is an attempt to make up this lacuna along the lines of Chris Atton’s 2006 alternative media theory. The analysis of the alternative media theory is complemented by an analysis of the texts of selected state-minded protest works from two crossover popular musicians – Blackface and Mr Raw – of re-democratized Nigeria, both of whose state-minded protest works have hitherto been unexplored by the academe.
- Full Text:
- Date Issued: 2020
- Authors: Osiebe, Garhe
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160423 , vital:40444 , DOI: 10.1080/21681392.2020.1810085
- Description: This paper centres on an alternative discourse of popular music culture in re-democratized Nigeria. Whereas much work has been done on state-minded protest music in Nigeria, studies have been reticent in appreciating the works of Fela's son, Femi; particularly within a framework of re-democratized Nigeria's equivalent of Fela's works which constituted a major alternative voice through military-ruled Nigeria. The paper is an attempt to make up this lacuna along the lines of Chris Atton’s 2006 alternative media theory. The analysis of the alternative media theory is complemented by an analysis of the texts of selected state-minded protest works from two crossover popular musicians – Blackface and Mr Raw – of re-democratized Nigeria, both of whose state-minded protest works have hitherto been unexplored by the academe.
- Full Text:
- Date Issued: 2020
‘That ever-blurry line between us and the criminals’: African Noir and the Ambiguity of Justice in MŨkoma wa NgŨgĨ’s Black Star Nairobi and Leye Adenle’s When Trouble Sleeps
- Authors: Naidu, Samantha
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158069 , vital:40145 , https://0-doi.org.wam.seals.ac.za/10.1093/fmls/cqaa020
- Description: This article, which focuses on African noir as a variety of neo-noir literature, begins by outlining the intertextual and intercultural relationships between classic noir and African noir. Thereafter, the postcolonial, postmodernist and transnational elements of African noir are described utilizing Mũkoma wa Ngũgĩ’s novel Black Star Nairobi (2013) and Leye Adenle’s When Trouble Sleeps (2018) as exemplars. Arguing that African noir draws on various genres and discourses, the article demonstrates how issues of socio-political justice, ontological and existential dilemmas, aesthetic concerns and the epistemological quest are rendered as ambiguous and murky. Based on a close reading of Black Star Nairobi and When Trouble Sleeps, the article concludes that the predominant chiaroscuro effect of African noir is not so much a ‘dark’ sensibility as one of abstruseness and poignant Afro-pessimism.
- Full Text:
- Date Issued: 2020
- Authors: Naidu, Samantha
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158069 , vital:40145 , https://0-doi.org.wam.seals.ac.za/10.1093/fmls/cqaa020
- Description: This article, which focuses on African noir as a variety of neo-noir literature, begins by outlining the intertextual and intercultural relationships between classic noir and African noir. Thereafter, the postcolonial, postmodernist and transnational elements of African noir are described utilizing Mũkoma wa Ngũgĩ’s novel Black Star Nairobi (2013) and Leye Adenle’s When Trouble Sleeps (2018) as exemplars. Arguing that African noir draws on various genres and discourses, the article demonstrates how issues of socio-political justice, ontological and existential dilemmas, aesthetic concerns and the epistemological quest are rendered as ambiguous and murky. Based on a close reading of Black Star Nairobi and When Trouble Sleeps, the article concludes that the predominant chiaroscuro effect of African noir is not so much a ‘dark’ sensibility as one of abstruseness and poignant Afro-pessimism.
- Full Text:
- Date Issued: 2020
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