An Immersive Audio Control System Using Mobile Devices and Ethernet AVB-Capable Speakers:
- Foss, Richard, Devonport, Sean
- Authors: Foss, Richard , Devonport, Sean
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426745 , vital:72388 , https://www.aes.org/e-lib/browse.cfm?elib=19714
- Description: Immersive Sound is commonly used to create the localization of sound sources above, below, and around listeners. To achieve this immersive goal, sound systems are employing an ever-increasing number of speakers. Given that immersive sound systems have large speaker configurations such as in cinemas, theaters, museums, and home theater installations, there is a need to provide control for these various contexts and also to provide a means of automating this control. An immersive sound system has been created that allows for the real-time control over sound source localization. It is a multi-user client/server system where the client devices are mobile devices, thereby allowing remote control over sound source localization. Touch and orientation capabilities of mobile devices are used for the generation of three-dimensional coordinates. The server receives localization control messages from the client and uses an Ethernet AVB (audio video bridging) network to distribute appropriate mix levels to speakers with built-in signal processing. These localization messages can be recorded by users for later playback.
- Full Text:
- Authors: Foss, Richard , Devonport, Sean
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426745 , vital:72388 , https://www.aes.org/e-lib/browse.cfm?elib=19714
- Description: Immersive Sound is commonly used to create the localization of sound sources above, below, and around listeners. To achieve this immersive goal, sound systems are employing an ever-increasing number of speakers. Given that immersive sound systems have large speaker configurations such as in cinemas, theaters, museums, and home theater installations, there is a need to provide control for these various contexts and also to provide a means of automating this control. An immersive sound system has been created that allows for the real-time control over sound source localization. It is a multi-user client/server system where the client devices are mobile devices, thereby allowing remote control over sound source localization. Touch and orientation capabilities of mobile devices are used for the generation of three-dimensional coordinates. The server receives localization control messages from the client and uses an Ethernet AVB (audio video bridging) network to distribute appropriate mix levels to speakers with built-in signal processing. These localization messages can be recorded by users for later playback.
- Full Text:
Designing writing groups to support postgraduate students’ academic writing: a case study from a South African university
- Authors: Wilmot, Kirstin
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66267 , vital:28926 , https://doi.org/10.1080/14703297.2016.1238775
- Description: publisher version , This paper reports on a writing group pilot programme implemented at a South African university. Drawing on literature, anonymous student evaluations and facilitator observations, it discusses the use of writing groups for supporting postgraduate academic writing practices. Developed within a broader postgraduate academic writing support programme, the paper discusses a case study of two pilot writing groups: a multidisciplinary long-term group and a disciplinary short-term ‘writing-intensive’ group. The findings indicate that the overall experience of the writing group was a positive one, with each group presenting varied ‘success’ aspects as well as challenges. Insights gleaned may contribute to our understanding of how these groups can be utilised to support postgraduate students and how different kinds of groups can be developed to serve particular student needs. The paper concludes with a discussion of the inclusion of a disciplinary expert, which proved particularly useful in this pilot.
- Full Text: false
- Authors: Wilmot, Kirstin
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66267 , vital:28926 , https://doi.org/10.1080/14703297.2016.1238775
- Description: publisher version , This paper reports on a writing group pilot programme implemented at a South African university. Drawing on literature, anonymous student evaluations and facilitator observations, it discusses the use of writing groups for supporting postgraduate academic writing practices. Developed within a broader postgraduate academic writing support programme, the paper discusses a case study of two pilot writing groups: a multidisciplinary long-term group and a disciplinary short-term ‘writing-intensive’ group. The findings indicate that the overall experience of the writing group was a positive one, with each group presenting varied ‘success’ aspects as well as challenges. Insights gleaned may contribute to our understanding of how these groups can be utilised to support postgraduate students and how different kinds of groups can be developed to serve particular student needs. The paper concludes with a discussion of the inclusion of a disciplinary expert, which proved particularly useful in this pilot.
- Full Text: false
Distinct responses of bacterial communities to agricultural and urban impacts in temperate southern African estuaries
- Matcher, Gwynneth F, Froneman, P William, Meiklejohn, Ian, Dorrington, Rosemary A
- Authors: Matcher, Gwynneth F , Froneman, P William , Meiklejohn, Ian , Dorrington, Rosemary A
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/479218 , vital:78271 , https://doi.org/10.1016/j.ecss.2017.11.015
- Description: Worldwide, estuaries are regarded as amongst the most ecologically threatened ecosystems and are increasingly being impacted by urban development, agricultural activities and reduced freshwater inflow. In this study, we examined the influence of different human activities on the diversity and structure of bacterial communities in the water column and sediment in three distinct, temperate permanently open estuarine systems within the same geographic region of southern Africa. The Kariega system is freshwater-deprived and is considered to be relatively pristine; the Kowie estuary is marine-dominated and impacted by urban development, while the Sundays system is fresh-water dominated and impacted by agricultural activity in its catchment. The bacterial communities in all three systems comprise predominantly heterotrophic species belonging to the Bacteroidetes and Proteobacteria phyla with little overlap between bacterioplankton and benthic bacterial communities at the species level. There was overlap between the operational taxonomic units (OTUs) of the Kowie and Kariega, both marine-influenced estuaries. However, lower species richness in the Kowie, likely reflects the impact of human settlements along the estuary. The dominant OTUs in the Sundays River system were distinct from those of the Kariega and Kowie estuaries with an overall decrease in species richness and evenness. This study provides an important snapshot into the microbial population structures of permanently open temperate estuarine systems and the influence of anthropogenic impacts on bacterial diversity and community structure.
- Full Text:
- Authors: Matcher, Gwynneth F , Froneman, P William , Meiklejohn, Ian , Dorrington, Rosemary A
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/479218 , vital:78271 , https://doi.org/10.1016/j.ecss.2017.11.015
- Description: Worldwide, estuaries are regarded as amongst the most ecologically threatened ecosystems and are increasingly being impacted by urban development, agricultural activities and reduced freshwater inflow. In this study, we examined the influence of different human activities on the diversity and structure of bacterial communities in the water column and sediment in three distinct, temperate permanently open estuarine systems within the same geographic region of southern Africa. The Kariega system is freshwater-deprived and is considered to be relatively pristine; the Kowie estuary is marine-dominated and impacted by urban development, while the Sundays system is fresh-water dominated and impacted by agricultural activity in its catchment. The bacterial communities in all three systems comprise predominantly heterotrophic species belonging to the Bacteroidetes and Proteobacteria phyla with little overlap between bacterioplankton and benthic bacterial communities at the species level. There was overlap between the operational taxonomic units (OTUs) of the Kowie and Kariega, both marine-influenced estuaries. However, lower species richness in the Kowie, likely reflects the impact of human settlements along the estuary. The dominant OTUs in the Sundays River system were distinct from those of the Kariega and Kowie estuaries with an overall decrease in species richness and evenness. This study provides an important snapshot into the microbial population structures of permanently open temperate estuarine systems and the influence of anthropogenic impacts on bacterial diversity and community structure.
- Full Text:
Extending the NFComms framework for bulk data transfers
- Pennefather, Sean, Bradshaw, Karen L, Irwin, Barry V W
- Authors: Pennefather, Sean , Bradshaw, Karen L , Irwin, Barry V W
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430152 , vital:72669 , https://doi.org/10.1145/3278681.3278686
- Description: In this paper we present the design and implementation of an indirect messaging extension for the existing NFComms framework that pro-vides communication between a network flow processor and host CPU. This extension addresses the bulk throughput limitations of the frame-work and is intended to work in conjunction with existing communication mediums. Testing of the framework extensions shows an increase in throughput performance of up to 300× that of the current direct mes-sage passing framework at the cost of increased single message laten-cy of up to 2×. This trade-off is considered acceptable as the proposed extensions are intended for bulk data transfer only while the existing message passing functionality of the framework is preserved and can be used in situations where low latency is required for small messages.
- Full Text:
- Authors: Pennefather, Sean , Bradshaw, Karen L , Irwin, Barry V W
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430152 , vital:72669 , https://doi.org/10.1145/3278681.3278686
- Description: In this paper we present the design and implementation of an indirect messaging extension for the existing NFComms framework that pro-vides communication between a network flow processor and host CPU. This extension addresses the bulk throughput limitations of the frame-work and is intended to work in conjunction with existing communication mediums. Testing of the framework extensions shows an increase in throughput performance of up to 300× that of the current direct mes-sage passing framework at the cost of increased single message laten-cy of up to 2×. This trade-off is considered acceptable as the proposed extensions are intended for bulk data transfer only while the existing message passing functionality of the framework is preserved and can be used in situations where low latency is required for small messages.
- Full Text:
Finding the bird in the bush, or,“the material that appears”: rethinking the ‘creative’in teaching ‘creative writing’
- Authors: Wessels, Paul
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/458498 , vital:75749 , https://hdl.handle.net/10520/EJC-1061d9acf3
- Description: If we want to bring assessment into alignment with teaching and learning practices in creative writing, we will need to change our conceptions of teaching and learning themselves. I believe there is a precedent for a changed conception of teaching and learning and will sketch the outline of such a change. I will do so via a practical example of a course I teach in creative writing, as well as via theoretical interventions from current educational theorists. I take my lead from a call made from within the imperilled waters of creativity such as it exists in creative writing today, that we need to pay attention to ontological and ethical issues if our conception of creativity is to survive the slide into the hyper-cynical discourse of advertising. Without changing our understanding of the “what” of education we will never arrive at the how or the why.
- Full Text:
- Authors: Wessels, Paul
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/458498 , vital:75749 , https://hdl.handle.net/10520/EJC-1061d9acf3
- Description: If we want to bring assessment into alignment with teaching and learning practices in creative writing, we will need to change our conceptions of teaching and learning themselves. I believe there is a precedent for a changed conception of teaching and learning and will sketch the outline of such a change. I will do so via a practical example of a course I teach in creative writing, as well as via theoretical interventions from current educational theorists. I take my lead from a call made from within the imperilled waters of creativity such as it exists in creative writing today, that we need to pay attention to ontological and ethical issues if our conception of creativity is to survive the slide into the hyper-cynical discourse of advertising. Without changing our understanding of the “what” of education we will never arrive at the how or the why.
- Full Text:
Metabolic activity throughout early development of dusky kob Argyrosomus japonicus (Sciaenidae)
- Edworthy, Carla, James, Nicola C, Erasmus, B, Kemp, Justin O G, Kaiser, Horst, Potts, Warren M
- Authors: Edworthy, Carla , James, Nicola C , Erasmus, B , Kemp, Justin O G , Kaiser, Horst , Potts, Warren M
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125159 , vital:35737 , https://doi.10.2989/1814232x.2018.1441907
- Description: Metabolism quantifies the energy-consuming activities of an organism (Nelson 2016) and is used as an indication of how organisms partition energy resources to activities that allow them to survive, grow and reproduce (Post and Lee 1996). The metabolic profile, which is a composition of the various metabolic rates of an individual, therefore gives an indication of the efficiency of energy transformation and allocation (Fry 1971; Brown et al. 2004). McKenzie et al. (2016) suggested that an organism’s physiology contributes towards its ability to survive under specific environmental conditions. As a result, physiological condition can be a reflection of the performance and fitness of an organism (Pörtner 2010). When combined with information on changing environmental conditions, physiological information can provide insight into species- and community-level responses (Pörtner and Farrell 2008). These kinds of data have served numerous ecological applications, including resource management, conservation (McKenzie et al. 2016) and climate-change assessments (Pörtner and Farrell 2008).
- Full Text:
- Authors: Edworthy, Carla , James, Nicola C , Erasmus, B , Kemp, Justin O G , Kaiser, Horst , Potts, Warren M
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125159 , vital:35737 , https://doi.10.2989/1814232x.2018.1441907
- Description: Metabolism quantifies the energy-consuming activities of an organism (Nelson 2016) and is used as an indication of how organisms partition energy resources to activities that allow them to survive, grow and reproduce (Post and Lee 1996). The metabolic profile, which is a composition of the various metabolic rates of an individual, therefore gives an indication of the efficiency of energy transformation and allocation (Fry 1971; Brown et al. 2004). McKenzie et al. (2016) suggested that an organism’s physiology contributes towards its ability to survive under specific environmental conditions. As a result, physiological condition can be a reflection of the performance and fitness of an organism (Pörtner 2010). When combined with information on changing environmental conditions, physiological information can provide insight into species- and community-level responses (Pörtner and Farrell 2008). These kinds of data have served numerous ecological applications, including resource management, conservation (McKenzie et al. 2016) and climate-change assessments (Pörtner and Farrell 2008).
- Full Text:
New thiazolidine-2,4-dione derivatives combined with organometallic ferrocene: Synthesis, structure and antiparasitic activity
- Oderinlo, Ogunyemi O, Tukulula, Matshawandile, Isaacs, Michelle, Taylor, Dale, Smith, Vincent J, Khanye, Setshaba D, Hoppe, Heinrich C
- Authors: Oderinlo, Ogunyemi O , Tukulula, Matshawandile , Isaacs, Michelle , Taylor, Dale , Smith, Vincent J , Khanye, Setshaba D , Hoppe, Heinrich C
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/122978 , vital:35382 , https://doi.org/10.1002/aoc.4385
- Description: Favourable physicochemical properties of an organometallic ferrocene and antiplasmodial potency of compounds containing the thiazolidine‐2,4‐dione framework (TZD‐4) prompted us to explore compounds containing both the thiazolidine‐2,4‐dione core and the ferrocenyl unit with the primary aim of identifying compounds with promising antiprotozoal activities. Thus, a new series of rationally designed ferrocene‐based thiazolidine‐2,4‐dione derivatives, containing a selection of secondary cyclic amines, was synthesised and fully characterised using standard spectroscopic techniques. The resulting compounds were screened for their antiplasmodial and antitrypanosomal activities against both the chloroquine‐resistant (Dd2) strain of Plasmodium falciparum and the Nagana Trypanosoma brucei brucei 427. The general trend that emerged indicated that the target compounds were more selective towards T. b. brucei compared to the P. falciparum parasite. Moreover, the analogues bearing methylpiperazine (8a) and piperidine (8b) rings were more active against T. b. brucei compared to hit compound TZD‐4. Except compound 8b, which appeared promising, none of the synthesised compounds showed better activity than TZD‐4 against the P. falciparum parasite. All the synthesised compounds were non‐toxic and often showed >90% viability of the HeLa cell line screened.
- Full Text:
- Authors: Oderinlo, Ogunyemi O , Tukulula, Matshawandile , Isaacs, Michelle , Taylor, Dale , Smith, Vincent J , Khanye, Setshaba D , Hoppe, Heinrich C
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/122978 , vital:35382 , https://doi.org/10.1002/aoc.4385
- Description: Favourable physicochemical properties of an organometallic ferrocene and antiplasmodial potency of compounds containing the thiazolidine‐2,4‐dione framework (TZD‐4) prompted us to explore compounds containing both the thiazolidine‐2,4‐dione core and the ferrocenyl unit with the primary aim of identifying compounds with promising antiprotozoal activities. Thus, a new series of rationally designed ferrocene‐based thiazolidine‐2,4‐dione derivatives, containing a selection of secondary cyclic amines, was synthesised and fully characterised using standard spectroscopic techniques. The resulting compounds were screened for their antiplasmodial and antitrypanosomal activities against both the chloroquine‐resistant (Dd2) strain of Plasmodium falciparum and the Nagana Trypanosoma brucei brucei 427. The general trend that emerged indicated that the target compounds were more selective towards T. b. brucei compared to the P. falciparum parasite. Moreover, the analogues bearing methylpiperazine (8a) and piperidine (8b) rings were more active against T. b. brucei compared to hit compound TZD‐4. Except compound 8b, which appeared promising, none of the synthesised compounds showed better activity than TZD‐4 against the P. falciparum parasite. All the synthesised compounds were non‐toxic and often showed >90% viability of the HeLa cell line screened.
- Full Text:
Phototransferred thermoluminescence of synthetic quartz: analysis of illumination-time response curves
- Chithambo, Makaiko L, Niyonzima, P, Kalita, Jitumani M
- Authors: Chithambo, Makaiko L , Niyonzima, P , Kalita, Jitumani M
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/111020 , vital:33364 , https://doi.org/10.1016/j.jlumin.2018.02.029
- Description: Phototransferred thermoluminescence (PTTL) induced in synthetic quartz by 470 nm blue light is reported. The glow curve measured at 5 °C/s up to 500 °C after irradiation to 100 Gy shows six peaks at 94, 116, 175, 212, 280 and 348 °C labelled I through VI and another one at 80 °C (labelled A1). PTTL is only observed for peaks A1 and I and is induced at peak A1 as long as peak III has been removed by preheating and at peak I after preheating to deplete peak VI. The inducement of PTTL even when all peaks have been removed points to deep electron traps in the quartz also acting as donors in addition to the putative ones below 500 °C. The PTTL intensity as a function of duration of illumination for A1 goes through a peak and decreases monotonically or to a stable value depending on the preheating temperature. The change of PTTL intensity as a function of illumination time is described using a set of coupled linear differential equations. The number of acceptors and donors in a particular system described in this way is influenced by the preheating temperature.
- Full Text: false
- Authors: Chithambo, Makaiko L , Niyonzima, P , Kalita, Jitumani M
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/111020 , vital:33364 , https://doi.org/10.1016/j.jlumin.2018.02.029
- Description: Phototransferred thermoluminescence (PTTL) induced in synthetic quartz by 470 nm blue light is reported. The glow curve measured at 5 °C/s up to 500 °C after irradiation to 100 Gy shows six peaks at 94, 116, 175, 212, 280 and 348 °C labelled I through VI and another one at 80 °C (labelled A1). PTTL is only observed for peaks A1 and I and is induced at peak A1 as long as peak III has been removed by preheating and at peak I after preheating to deplete peak VI. The inducement of PTTL even when all peaks have been removed points to deep electron traps in the quartz also acting as donors in addition to the putative ones below 500 °C. The PTTL intensity as a function of duration of illumination for A1 goes through a peak and decreases monotonically or to a stable value depending on the preheating temperature. The change of PTTL intensity as a function of illumination time is described using a set of coupled linear differential equations. The number of acceptors and donors in a particular system described in this way is influenced by the preheating temperature.
- Full Text: false
Sacrificial males the potential role of copulation and predation in contributing to copepod sex-skewed ratios
- Wasserman, Ryan J, Weston, Mark, Weyl, Olaf, L F, Froneman, P William, Welch, Rebecca J, Vink, Tim J F, Dalu, Tatenda
- Authors: Wasserman, Ryan J , Weston, Mark , Weyl, Olaf, L F , Froneman, P William , Welch, Rebecca J , Vink, Tim J F , Dalu, Tatenda
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/467233 , vital:76843 , https://doi.org/10.1111/oik.04832
- Description: Predation is thought to play a selective role in the emergence of behavioural traits in prey. Differences in behaviour between prey demographics may, therefore, be driven by predation with select components of the population being less vulnerable to predators. While under controlled conditions prey demography has been shown to have consequences for predation success, investigations linking these implications to natural prey population demographics are scarce. Here we assess predator–prey dynamics between notonectid predators (backswimmers) and Lovenula raynerae (Copepoda), key faunal groups in temperate ephemeral pond ecosystems. Using a combination of field and experimental approaches we test for the development and mechanism of predation‐induced sex‐skewed ratios. A natural population of L. raynerae was tracked over time in relation to their predator (notonectid) and prey (Cladocera) numbers. In the laboratory, L. raynerae sex ratios were also assessed over time but in the absence of predation pressure.
- Full Text:
- Authors: Wasserman, Ryan J , Weston, Mark , Weyl, Olaf, L F , Froneman, P William , Welch, Rebecca J , Vink, Tim J F , Dalu, Tatenda
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/467233 , vital:76843 , https://doi.org/10.1111/oik.04832
- Description: Predation is thought to play a selective role in the emergence of behavioural traits in prey. Differences in behaviour between prey demographics may, therefore, be driven by predation with select components of the population being less vulnerable to predators. While under controlled conditions prey demography has been shown to have consequences for predation success, investigations linking these implications to natural prey population demographics are scarce. Here we assess predator–prey dynamics between notonectid predators (backswimmers) and Lovenula raynerae (Copepoda), key faunal groups in temperate ephemeral pond ecosystems. Using a combination of field and experimental approaches we test for the development and mechanism of predation‐induced sex‐skewed ratios. A natural population of L. raynerae was tracked over time in relation to their predator (notonectid) and prey (Cladocera) numbers. In the laboratory, L. raynerae sex ratios were also assessed over time but in the absence of predation pressure.
- Full Text:
South African national reconciliation discourse and isiXhosa written poetry: 1994–2004
- Mona, Godfrey V, Kaschula, Russell H
- Authors: Mona, Godfrey V , Kaschula, Russell H
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/174690 , vital:42501 , DOI: 10.1080/02572117.2018.1429867
- Description: The main thesis put forward in this article is that during the first ten years of democracy in South Africa, 1994–2004, isiXhosa poetry contributed thematically to the goal of reconciliation. Furthermore, this poetry demonstrates how an aspect of culture can be employed to advance the sociopolitical process of reconciliation. IsiXhosa writers, through their poetry, exposed the on-the-ground endeavours that contributed to the broader and deepening reconciliation process, thereby making a meaningful contribution towards the interpretation and building of a fair, democratic and inclusive South African society. The article analyses a number of poems against the backdrop of the post-1994 reconciliation process in South Africa.
- Full Text:
- Authors: Mona, Godfrey V , Kaschula, Russell H
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/174690 , vital:42501 , DOI: 10.1080/02572117.2018.1429867
- Description: The main thesis put forward in this article is that during the first ten years of democracy in South Africa, 1994–2004, isiXhosa poetry contributed thematically to the goal of reconciliation. Furthermore, this poetry demonstrates how an aspect of culture can be employed to advance the sociopolitical process of reconciliation. IsiXhosa writers, through their poetry, exposed the on-the-ground endeavours that contributed to the broader and deepening reconciliation process, thereby making a meaningful contribution towards the interpretation and building of a fair, democratic and inclusive South African society. The article analyses a number of poems against the backdrop of the post-1994 reconciliation process in South Africa.
- Full Text:
Toward distributed key management for offline authentication
- Linklater, Gregory, Smith, Christian, Herbert, Alan, Irwin, Barry V W
- Authors: Linklater, Gregory , Smith, Christian , Herbert, Alan , Irwin, Barry V W
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430283 , vital:72680 , https://doi.org/10.1145/3278681.3278683
- Description: Self-sovereign identity promises prospective users greater control, security, privacy, portability and overall greater convenience; however the immaturity of current distributed key management solutions results in general disregard of security advisories in favour of convenience and accessibility. This research proposes the use of intermediate certificates as a distributed key management solution. Intermediate certificates will be shown to allow multiple keys to authenticate to a single self-sovereign identity. Keys may be freely added to an identity without requiring a distributed ledger, any other third-party service or sharing private keys between devices. This research will also show that key rotation is a superior alternative to existing key recovery and escrow systems in helping users recover when their keys are lost or compromised. These features will allow remote credentials to be used to issuer, present and appraise remote attestations, without relying on a constant Internet connection.
- Full Text:
- Authors: Linklater, Gregory , Smith, Christian , Herbert, Alan , Irwin, Barry V W
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430283 , vital:72680 , https://doi.org/10.1145/3278681.3278683
- Description: Self-sovereign identity promises prospective users greater control, security, privacy, portability and overall greater convenience; however the immaturity of current distributed key management solutions results in general disregard of security advisories in favour of convenience and accessibility. This research proposes the use of intermediate certificates as a distributed key management solution. Intermediate certificates will be shown to allow multiple keys to authenticate to a single self-sovereign identity. Keys may be freely added to an identity without requiring a distributed ledger, any other third-party service or sharing private keys between devices. This research will also show that key rotation is a superior alternative to existing key recovery and escrow systems in helping users recover when their keys are lost or compromised. These features will allow remote credentials to be used to issuer, present and appraise remote attestations, without relying on a constant Internet connection.
- Full Text:
An Exploratory Study of the Relationship between Learners’ Attitudes Towards Learning Science and Characteristics of an Afterschool Science Club
- Agunbiade, Esther, Ngcoza, Kenneth M, Jawahar, Kavish, Sewry, Joyce
- Authors: Agunbiade, Esther , Ngcoza, Kenneth M , Jawahar, Kavish , Sewry, Joyce
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/483279 , vital:78739 , https://doi.org/10.1080/18117295.2017.1369274
- Description: The Khanya Maths and Science Club (KMSC) is an afterschool science/maths enrichment programme for learners in Grades 7–12 supported by postgraduate students and academic staff volunteers. This research seeks to explore the relationship between participating learners’ attitude toward learning science and the characteristics of this afterschool science club. The study draws from Wenger’s community of practice model to explore the features. Six learners participating in the KMSC were interviewed and their journal entries were analysed inductively, resulting in three themes. The study revealed that learners’ attitudes towards learning science were associated with the club’s instructional characteristics, facilitators/environmental characteristics and the level to which science was connected with everyday life. These characteristics are also related to the community of practice elements. It was concluded that incorporating the community of practice model in structuring afterschool science activities could have a positive influence on learners’ attitude towards learning science.
- Full Text:
- Authors: Agunbiade, Esther , Ngcoza, Kenneth M , Jawahar, Kavish , Sewry, Joyce
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/483279 , vital:78739 , https://doi.org/10.1080/18117295.2017.1369274
- Description: The Khanya Maths and Science Club (KMSC) is an afterschool science/maths enrichment programme for learners in Grades 7–12 supported by postgraduate students and academic staff volunteers. This research seeks to explore the relationship between participating learners’ attitude toward learning science and the characteristics of this afterschool science club. The study draws from Wenger’s community of practice model to explore the features. Six learners participating in the KMSC were interviewed and their journal entries were analysed inductively, resulting in three themes. The study revealed that learners’ attitudes towards learning science were associated with the club’s instructional characteristics, facilitators/environmental characteristics and the level to which science was connected with everyday life. These characteristics are also related to the community of practice elements. It was concluded that incorporating the community of practice model in structuring afterschool science activities could have a positive influence on learners’ attitude towards learning science.
- Full Text:
Biogeographical comparison of the emergent macrophyte, Sagittaria platyphylla in its native and introduced ranges
- Kwong, Raelene M, Sagliocco, Jean Louis, Harms, Nathan E, Butler, Kym L, Green, Peter T, Martin, Grant D
- Authors: Kwong, Raelene M , Sagliocco, Jean Louis , Harms, Nathan E , Butler, Kym L , Green, Peter T , Martin, Grant D
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76980 , vital:30652 , https://doi.org/10.1016/j.aquabot.2017.05.001
- Description: Understanding why some plant species become invasive is important to predict and prevent future weed threats and identify appropriate management strategies. Many hypotheses have been proposed to explain why plants become invasive, yet few studies have quantitatively compared plant and population parameters between native and introduced range populations to gain an objective perspective on the causes of plant invasion. The present study uses a biogeographical field survey to compare morphological and reproductive traits and abundance between the native range (USA) and two introduced ranges (Australia and South Africa) of Sagittaria platyphylla (Engelm.) J.G. Sm (Alismataceae), a highly invasive freshwater macrophyte. Introduced and native populations differed in sexual reproductive output with the number of achenes per fruiting head and individual achene weight found to be 40% and 50% greater in introduced populations respectively. However, no other morphological traits were found to be consistently different between the native and both introduced ranges, especially after taking into account differences in environmental conditions between the three ranges. Although populations in introduced regions were larger and occupied greater percentage cover, no differences in plant density were evident. Our results suggest that, apart from sexual reproduction, many of the trait patterns observed in S. platyphylla are influenced by environmental and habitat conditions within the native and invaded ranges. We conclude that the enemy release hypothesis best explains the results observed for sexual reproduction. In particular, we hypothesise that a release from natural enemies, specifically a pre-dispersal seed predator, may induce reproductive plasticity in S. platyphylla.
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- Authors: Kwong, Raelene M , Sagliocco, Jean Louis , Harms, Nathan E , Butler, Kym L , Green, Peter T , Martin, Grant D
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76980 , vital:30652 , https://doi.org/10.1016/j.aquabot.2017.05.001
- Description: Understanding why some plant species become invasive is important to predict and prevent future weed threats and identify appropriate management strategies. Many hypotheses have been proposed to explain why plants become invasive, yet few studies have quantitatively compared plant and population parameters between native and introduced range populations to gain an objective perspective on the causes of plant invasion. The present study uses a biogeographical field survey to compare morphological and reproductive traits and abundance between the native range (USA) and two introduced ranges (Australia and South Africa) of Sagittaria platyphylla (Engelm.) J.G. Sm (Alismataceae), a highly invasive freshwater macrophyte. Introduced and native populations differed in sexual reproductive output with the number of achenes per fruiting head and individual achene weight found to be 40% and 50% greater in introduced populations respectively. However, no other morphological traits were found to be consistently different between the native and both introduced ranges, especially after taking into account differences in environmental conditions between the three ranges. Although populations in introduced regions were larger and occupied greater percentage cover, no differences in plant density were evident. Our results suggest that, apart from sexual reproduction, many of the trait patterns observed in S. platyphylla are influenced by environmental and habitat conditions within the native and invaded ranges. We conclude that the enemy release hypothesis best explains the results observed for sexual reproduction. In particular, we hypothesise that a release from natural enemies, specifically a pre-dispersal seed predator, may induce reproductive plasticity in S. platyphylla.
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Extended use of grey water for irrigating home gardens in an arid environment
- Al-Ismaili, Abdulrahim M, Ahmed, Mushtaque, Al-Busaidi, Ahmed, Al-Adawi, Seif, Tandlich, Roman, Al-Amri, Mohammed
- Authors: Al-Ismaili, Abdulrahim M , Ahmed, Mushtaque , Al-Busaidi, Ahmed , Al-Adawi, Seif , Tandlich, Roman , Al-Amri, Mohammed
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76048 , vital:30497 , https://doi.org/10.1007/s11356-017-8963-z
- Description: The use of treated grey water (GW) for home gardens, peri-urban agriculture and landscaping is becoming popular in many water stressed countries such as Oman. This study aims to investigate the treatment efficacy, health and chemical concerns, cost-benefits and maintenance protocol of a GW treatment system as well as the effect of irrigation with GW on crop yield. Therefore, a decentralized homemade GW treatment system was installed in a newly constructed house in Muscat, Oman and studied over a 2-year period. The treated GW was found to be suitable for irrigation as per Omani standards. GW when mixed with kitchen effluent substituted the use of nutrient supplements for plants and did not show any harmful chemical or biological contamination. The capital cost of the system was around US $980, and the annual operating cost was US $78 with annual income and savings from the system being around US $572 indicating a payback period of nearly 2 years. It was found that the system required simple but regular maintenance particularly cleaning of the top layer of the filter. It can be concluded from this study that such a GW system should be technically, economically and environmentally feasible in Oman. Also, wider acceptance by the general public to the idea of GW reuse will help in mitigating the water shortage problem of the country to some extent.
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- Authors: Al-Ismaili, Abdulrahim M , Ahmed, Mushtaque , Al-Busaidi, Ahmed , Al-Adawi, Seif , Tandlich, Roman , Al-Amri, Mohammed
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76048 , vital:30497 , https://doi.org/10.1007/s11356-017-8963-z
- Description: The use of treated grey water (GW) for home gardens, peri-urban agriculture and landscaping is becoming popular in many water stressed countries such as Oman. This study aims to investigate the treatment efficacy, health and chemical concerns, cost-benefits and maintenance protocol of a GW treatment system as well as the effect of irrigation with GW on crop yield. Therefore, a decentralized homemade GW treatment system was installed in a newly constructed house in Muscat, Oman and studied over a 2-year period. The treated GW was found to be suitable for irrigation as per Omani standards. GW when mixed with kitchen effluent substituted the use of nutrient supplements for plants and did not show any harmful chemical or biological contamination. The capital cost of the system was around US $980, and the annual operating cost was US $78 with annual income and savings from the system being around US $572 indicating a payback period of nearly 2 years. It was found that the system required simple but regular maintenance particularly cleaning of the top layer of the filter. It can be concluded from this study that such a GW system should be technically, economically and environmentally feasible in Oman. Also, wider acceptance by the general public to the idea of GW reuse will help in mitigating the water shortage problem of the country to some extent.
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Integrating Climate Change Adaptation (CCA) and Disaster Risk Reduction (DRR) for greater local level resilience: lessons from a multi-stakeholder think-tank
- Pereira, Taryn, Shackleton, Sheona E, Donkor, Felix Kwabena
- Authors: Pereira, Taryn , Shackleton, Sheona E , Donkor, Felix Kwabena
- Date: 2017
- Subjects: Climatic changes -- South Africa , Climatic changes -- South Africa -- Eastern Cape -- South Africa
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/62027 , vital:28097
- Description: The last few years have seen one of the most severe droughts in recent times in the southern African region, and news headlines are increasingly full of warnings about heavy storms, fires and floods. There is no doubt that extreme hydro-meteorological events, and their multiple and potentially disastrous impacts, are at the forefront of the public consciousness at the present time and are one of the key concerns regarding the impacts of climate change in the region. While the links between extreme climate events, disaster risk reduction (DRR - see Box 1) and climate change adaptation (CCA - see Box 2) are recognised in the South African Climate Change White Paper, this is not the case for the whole region. Furthermore, even if there is national recognition of the need to synergise these two spheres of endeavour, this does not always trickle down to effective policy, planning and implementation at the local level.
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- Authors: Pereira, Taryn , Shackleton, Sheona E , Donkor, Felix Kwabena
- Date: 2017
- Subjects: Climatic changes -- South Africa , Climatic changes -- South Africa -- Eastern Cape -- South Africa
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/62027 , vital:28097
- Description: The last few years have seen one of the most severe droughts in recent times in the southern African region, and news headlines are increasingly full of warnings about heavy storms, fires and floods. There is no doubt that extreme hydro-meteorological events, and their multiple and potentially disastrous impacts, are at the forefront of the public consciousness at the present time and are one of the key concerns regarding the impacts of climate change in the region. While the links between extreme climate events, disaster risk reduction (DRR - see Box 1) and climate change adaptation (CCA - see Box 2) are recognised in the South African Climate Change White Paper, this is not the case for the whole region. Furthermore, even if there is national recognition of the need to synergise these two spheres of endeavour, this does not always trickle down to effective policy, planning and implementation at the local level.
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Investigating the effects various compilers have on the electromagnetic signature of a cryptographic executable
- Frieslaar, Ibraheem, Irwin, Barry V W
- Authors: Frieslaar, Ibraheem , Irwin, Barry V W
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430207 , vital:72673 , https://doi.org/10.1145/3129416.3129436
- Description: This research investigates changes in the electromagnetic (EM) signatures of a cryptographic binary executable based on compile-time parameters to the GNU and clang compilers. The source code was compiled and executed on a Raspberry Pi 2, which utilizes the ARMv7 CPU. Various optimization flags are enabled at compile-time and the output of the binary executable's EM signatures are captured at run-time. It is demonstrated that GNU and clang compilers produced different EM signature on program execution. The results indicated while utilizing the O3 optimization flag, the EM signature of the program changes. Additionally, the g++ compiler demonstrated fewer instructions were required to run the executable; this related to fewer EM emissions leaked. The EM data from the various compilers under different optimization levels was used as input data for a correlation power analysis attack. The results indicated that partial AES-128 encryption keys was possible. In addition, the fewest subkeys recovered was when the clang compiler was used with level O2 optimization. Finally, the research was able to recover 15 of 16 AES-128 cryptographic algorithm's subkeys, from the the Pi.
- Full Text:
- Authors: Frieslaar, Ibraheem , Irwin, Barry V W
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430207 , vital:72673 , https://doi.org/10.1145/3129416.3129436
- Description: This research investigates changes in the electromagnetic (EM) signatures of a cryptographic binary executable based on compile-time parameters to the GNU and clang compilers. The source code was compiled and executed on a Raspberry Pi 2, which utilizes the ARMv7 CPU. Various optimization flags are enabled at compile-time and the output of the binary executable's EM signatures are captured at run-time. It is demonstrated that GNU and clang compilers produced different EM signature on program execution. The results indicated while utilizing the O3 optimization flag, the EM signature of the program changes. Additionally, the g++ compiler demonstrated fewer instructions were required to run the executable; this related to fewer EM emissions leaked. The EM data from the various compilers under different optimization levels was used as input data for a correlation power analysis attack. The results indicated that partial AES-128 encryption keys was possible. In addition, the fewest subkeys recovered was when the clang compiler was used with level O2 optimization. Finally, the research was able to recover 15 of 16 AES-128 cryptographic algorithm's subkeys, from the the Pi.
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Issues-Based Enquiry: An Enabling Pedagogy for ESD in Teacher Education and School Geography
- Authors: Wilmot, P Dianne
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/436266 , vital:73253 , ISBN 978-3-319-45989-9 , https://doi.org/10.1007/978-3-319-45989-9_10
- Description: This chapter addresses the need for innovations in geography teacher education programmes in a developing world context. More specifically, it responds to the need for practical ‘how to’ examples for ESD integration into school geography by de-scribing a pedagogical experiment that was piloted with in-service Namibian teachers and education development offic-ers (EDOs) enrolled for a Bachelor of Education (Honours) de-gree in 2014. The theoretical constructs underpinning the ex-periment’s design and pedagogical approach as well as the teacher professional development model are described. This is followed by a description and justification of the methodology used to answer the research question: ‘How can issues-based enquiry enable the integration of ESD at the micro level of the classroom?’ The findings of the experiment provide evidence of how issues-based enquiry, underpinned by active learning and constructivist epistemology and a model of teacher pro-fessional development located in reflexive practice, enabled the teachers to acquire foundational knowledge and pedagog-ical content knowledge for effective integration of ESD into school geography. This chapter may offer other teacher educators some guidelines on how to develop teacher capacity to integrate ESD into their own programmes.
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- Authors: Wilmot, P Dianne
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/436266 , vital:73253 , ISBN 978-3-319-45989-9 , https://doi.org/10.1007/978-3-319-45989-9_10
- Description: This chapter addresses the need for innovations in geography teacher education programmes in a developing world context. More specifically, it responds to the need for practical ‘how to’ examples for ESD integration into school geography by de-scribing a pedagogical experiment that was piloted with in-service Namibian teachers and education development offic-ers (EDOs) enrolled for a Bachelor of Education (Honours) de-gree in 2014. The theoretical constructs underpinning the ex-periment’s design and pedagogical approach as well as the teacher professional development model are described. This is followed by a description and justification of the methodology used to answer the research question: ‘How can issues-based enquiry enable the integration of ESD at the micro level of the classroom?’ The findings of the experiment provide evidence of how issues-based enquiry, underpinned by active learning and constructivist epistemology and a model of teacher pro-fessional development located in reflexive practice, enabled the teachers to acquire foundational knowledge and pedagog-ical content knowledge for effective integration of ESD into school geography. This chapter may offer other teacher educators some guidelines on how to develop teacher capacity to integrate ESD into their own programmes.
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Life-histories explain the conservation status of two estuary-associated pipefishes
- Whitfield, Alan K, Mkare, Thomas K, Teske, Peter R, James, Nicola C, Cowley, Paul D
- Authors: Whitfield, Alan K , Mkare, Thomas K , Teske, Peter R , James, Nicola C , Cowley, Paul D
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445087 , vital:74346 , https://doi.org/10.1016/j.biocon.2017.06.024
- Description: Two endemic southern African pipefish species (Teleostei: Syngnathidae) co-occur in estuaries on the southeast coast of South Africa. The larger longsnout pipefish, Syngnathus temminckii, is abundant and has a wide range that comprises coastal and estuarine habitats in all three of the region's marine biogeographic provinces. In contrast, the smaller estuarine pipefish S. watermeyeri is critically endangered, and confined to a few warm-temperate estuaries. Here, we explore reasons for these considerable differences in conservation status.
- Full Text:
- Authors: Whitfield, Alan K , Mkare, Thomas K , Teske, Peter R , James, Nicola C , Cowley, Paul D
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445087 , vital:74346 , https://doi.org/10.1016/j.biocon.2017.06.024
- Description: Two endemic southern African pipefish species (Teleostei: Syngnathidae) co-occur in estuaries on the southeast coast of South Africa. The larger longsnout pipefish, Syngnathus temminckii, is abundant and has a wide range that comprises coastal and estuarine habitats in all three of the region's marine biogeographic provinces. In contrast, the smaller estuarine pipefish S. watermeyeri is critically endangered, and confined to a few warm-temperate estuaries. Here, we explore reasons for these considerable differences in conservation status.
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Method and madness: de/colonising scholarship and theatre research with participants labelled mad
- Authors: Sutherland, Alexandra
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/469566 , vital:77268 , https://doi.org/10.1080/13569783.2017.1326805
- Description: This article discusses a long-term theatre project that I run with mental health care users and staff in a forensic psychiatric hospital in South Africa. I argue that the values underpinning the project align with those of Mad Studies, a field that is located as an emerging academic discipline within disability studies. The article seeks to problematise the conceptual frameworks available to a researcher working within theatre and disability in the global South. As a researcher, I may choose the framework of ‘madness’ as part of a social justice research stance. However, in a South African context of little to no psychiatric survivor/consumer activism, this may not in any way be adopted, understood, or claimed by any of the people who suffer ‘madness’ and with whom I create theatre. This article seeks to provoke questions around applied theatre disability research and the potential for research practices to de/re colonise.
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- Authors: Sutherland, Alexandra
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/469566 , vital:77268 , https://doi.org/10.1080/13569783.2017.1326805
- Description: This article discusses a long-term theatre project that I run with mental health care users and staff in a forensic psychiatric hospital in South Africa. I argue that the values underpinning the project align with those of Mad Studies, a field that is located as an emerging academic discipline within disability studies. The article seeks to problematise the conceptual frameworks available to a researcher working within theatre and disability in the global South. As a researcher, I may choose the framework of ‘madness’ as part of a social justice research stance. However, in a South African context of little to no psychiatric survivor/consumer activism, this may not in any way be adopted, understood, or claimed by any of the people who suffer ‘madness’ and with whom I create theatre. This article seeks to provoke questions around applied theatre disability research and the potential for research practices to de/re colonise.
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Quantifying the economic water savings benefit of water hyacinth (Eichhornia crassipes) control in the Vaalharts Irrigation Scheme
- Arp, Reinhardt S, Fraser, Gavin C G, Hill, Martin P
- Authors: Arp, Reinhardt S , Fraser, Gavin C G , Hill, Martin P
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/472762 , vital:77570 , https://www.ajol.info/index.php/wsa/article/view/150822
- Description: Global freshwater resources are threatened by an ever-growing population and continued economic development, highlighting the need for sustainable water management. Sustainable management must include the control of any additional factors that may aggravate water scarcity, such as invasive alien plants. Water hyacinth (Eichhornia crassipes), one of the world’s most destructive invasive plants, presents a direct threat to economically productive water resources. Through high levels of evapotranspiration, water hyacinth leads to substantial water losses that could otherwise be used more productively, thereby creating an externality on water-dependent industries, such as irrigation-fed agriculture. This study provides an economic valuation of the water-saving benefit of water hyacinth control, using Warrenton Weir on the Vaalharts Irrigation Scheme as a case study. A Residual Value Method was employed to estimate the average production value of irrigation water, based on water’s relative proportion of total costs (TC), to serve as a proxy for the value of water lost via evapotranspiration by water hyacinth. Three evapotranspiration to evaporation ratios, derived from the literature, at three levels of invasion (100; 50 and 25% cover), were used to estimate the annual water loss at Warrenton Weir. The average production value of irrigation water was estimated to be R38.71/m3, which translated into an annual benefit of between R54 million and R1.18 billion. These results highlight the need for invasive plant control, particularly in economically productive water resources. An alien plant control policy should prioritise invasions of this nature, as they present significant costs to the economy and threaten the sustainability of freshwater resources.
- Full Text:
- Authors: Arp, Reinhardt S , Fraser, Gavin C G , Hill, Martin P
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/472762 , vital:77570 , https://www.ajol.info/index.php/wsa/article/view/150822
- Description: Global freshwater resources are threatened by an ever-growing population and continued economic development, highlighting the need for sustainable water management. Sustainable management must include the control of any additional factors that may aggravate water scarcity, such as invasive alien plants. Water hyacinth (Eichhornia crassipes), one of the world’s most destructive invasive plants, presents a direct threat to economically productive water resources. Through high levels of evapotranspiration, water hyacinth leads to substantial water losses that could otherwise be used more productively, thereby creating an externality on water-dependent industries, such as irrigation-fed agriculture. This study provides an economic valuation of the water-saving benefit of water hyacinth control, using Warrenton Weir on the Vaalharts Irrigation Scheme as a case study. A Residual Value Method was employed to estimate the average production value of irrigation water, based on water’s relative proportion of total costs (TC), to serve as a proxy for the value of water lost via evapotranspiration by water hyacinth. Three evapotranspiration to evaporation ratios, derived from the literature, at three levels of invasion (100; 50 and 25% cover), were used to estimate the annual water loss at Warrenton Weir. The average production value of irrigation water was estimated to be R38.71/m3, which translated into an annual benefit of between R54 million and R1.18 billion. These results highlight the need for invasive plant control, particularly in economically productive water resources. An alien plant control policy should prioritise invasions of this nature, as they present significant costs to the economy and threaten the sustainability of freshwater resources.
- Full Text: