Students’ reception of peer assessment of group-work contributions: problematics in terms of race and gender emerging from a South African case study
- Thondhlana, Gladman, Belluigi, Dina Z
- Authors: Thondhlana, Gladman , Belluigi, Dina Z
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59784 , vital:27649 , https://doi.org/10.1080/02602938.2016.1235133
- Description: Participatory assessment is increasingly employed in higher education worldwide as a formative mechanism to support students’ active learning. But do students in an increasingly relationally diverse environment perceive that peer assessment of individuals’ contributions to group-work tasks enhances their learning? Recognising the impact of students’ conceptions on the quality of their learning, this study considers students’ perspectives of peer assessment of group-work contributions at a South African university. Questionnaires elicited students’ perspectives of and general attitudes towards assessment of and by their peers. A growing measure of discontent with the process of assessing peer contributions to group tasks emerged, including actual and perceived racial and gender stereotyping, and related rejection-sensitivity. These initial findings were checked against the students’ experiences in a report-and-respond process that enabled probing discussions of the interpretations. This paper examines and explores the implications of such identifications and receptions for learning engagement and group-work curriculum development in the context of a rapidly transforming higher education sector.
- Full Text: false
- Date Issued: 2016
- Authors: Thondhlana, Gladman , Belluigi, Dina Z
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59784 , vital:27649 , https://doi.org/10.1080/02602938.2016.1235133
- Description: Participatory assessment is increasingly employed in higher education worldwide as a formative mechanism to support students’ active learning. But do students in an increasingly relationally diverse environment perceive that peer assessment of individuals’ contributions to group-work tasks enhances their learning? Recognising the impact of students’ conceptions on the quality of their learning, this study considers students’ perspectives of peer assessment of group-work contributions at a South African university. Questionnaires elicited students’ perspectives of and general attitudes towards assessment of and by their peers. A growing measure of discontent with the process of assessing peer contributions to group tasks emerged, including actual and perceived racial and gender stereotyping, and related rejection-sensitivity. These initial findings were checked against the students’ experiences in a report-and-respond process that enabled probing discussions of the interpretations. This paper examines and explores the implications of such identifications and receptions for learning engagement and group-work curriculum development in the context of a rapidly transforming higher education sector.
- Full Text: false
- Date Issued: 2016
Surfing the waves of learning: enacting a Semantics analysis of teaching in a first-year Law course
- Authors: Clarence, Sherran
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59816 , vital:27654 , https://doi.org/10.1080/07294360.2016.1263831
- Description: Students’ ability to build knowledge, and transfer it within and between contexts is crucial to cumulative learning and to academic success. This has long been a concern of higher education research and practice. A central part of this concern for educators is creating the conditions that enable their students' deep learning, as this is an area of significant struggle for many students. Legitimation Code Theory, in particular the dimension of Semantics, is proving useful in examining the kinds of conditions that may be necessary for students to build disciplinary knowledge cumulatively over time. Using illustrative data from one case study, this paper suggests that the conceptual tools offered by Semantics can provide academic lecturers and academic development staff with a set of conceptual and analytical tools which can enable them to ‘see’ and understand the ways in which knowledge can be cumulatively acquired and used, as well as the possible gaps between what they are teaching and what their students may be learning. The hope is that these new insights will provide new directions for change in teaching and learning where these may be needed.
- Full Text: false
- Date Issued: 2016
- Authors: Clarence, Sherran
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59816 , vital:27654 , https://doi.org/10.1080/07294360.2016.1263831
- Description: Students’ ability to build knowledge, and transfer it within and between contexts is crucial to cumulative learning and to academic success. This has long been a concern of higher education research and practice. A central part of this concern for educators is creating the conditions that enable their students' deep learning, as this is an area of significant struggle for many students. Legitimation Code Theory, in particular the dimension of Semantics, is proving useful in examining the kinds of conditions that may be necessary for students to build disciplinary knowledge cumulatively over time. Using illustrative data from one case study, this paper suggests that the conceptual tools offered by Semantics can provide academic lecturers and academic development staff with a set of conceptual and analytical tools which can enable them to ‘see’ and understand the ways in which knowledge can be cumulatively acquired and used, as well as the possible gaps between what they are teaching and what their students may be learning. The hope is that these new insights will provide new directions for change in teaching and learning where these may be needed.
- Full Text: false
- Date Issued: 2016
Synthesis and evaluation of substituted 4-(N-benzylamino)cinnamate esters as potential anti-cancer agents and HIV-1 integrase inhibitors
- Faridoon, H, Edkins, Adrienne L, Isaacs, Michelle, Mnkandhla, Dumisani, Hoppe, Heinrich C, Kaye, Perry T
- Authors: Faridoon, H , Edkins, Adrienne L , Isaacs, Michelle , Mnkandhla, Dumisani , Hoppe, Heinrich C , Kaye, Perry T
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66289 , vital:28929 , https://doi.org/10.1016/j.bmcl.2016.05.023
- Description: publisher version , Encouraging selectivity and low micromolar activity against HeLa cervical carcinoma (IC50 ⩾ 3.0 μM) and the aggressive MDA-MB-231 triple negative breast carcinoma (IC50 ⩾ 9.6 μM) cell lines has been exhibited by a number of readily accessible 4-(N-benzylamino)cinnamate esters. The potential of the ligands as HIV-1 integrase inhibitors has also been examined.
- Full Text: false
- Date Issued: 2016
- Authors: Faridoon, H , Edkins, Adrienne L , Isaacs, Michelle , Mnkandhla, Dumisani , Hoppe, Heinrich C , Kaye, Perry T
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66289 , vital:28929 , https://doi.org/10.1016/j.bmcl.2016.05.023
- Description: publisher version , Encouraging selectivity and low micromolar activity against HeLa cervical carcinoma (IC50 ⩾ 3.0 μM) and the aggressive MDA-MB-231 triple negative breast carcinoma (IC50 ⩾ 9.6 μM) cell lines has been exhibited by a number of readily accessible 4-(N-benzylamino)cinnamate esters. The potential of the ligands as HIV-1 integrase inhibitors has also been examined.
- Full Text: false
- Date Issued: 2016
The complex immunological and inflammatory network of adipose tissue in obesity
- Apostolopoulos, Vasso, De Courten, Maximilian P J, Stojanovska, Lily, Blatch, Gregory L, Tangalakis, Kathy, De Courten, Barbora
- Authors: Apostolopoulos, Vasso , De Courten, Maximilian P J , Stojanovska, Lily , Blatch, Gregory L , Tangalakis, Kathy , De Courten, Barbora
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66120 , vital:28905 , https://doi.org/10.1002/mnfr.201500272
- Description: publisher version , A number of approaches have been utilized in the prevention, management, and treatment of obesity, including, surgery, medication, diet, exercise, and overall lifestyle changes. Despite these interventions, the prevalence of obesity and the various disorders related to it is growing. In obesity, there is a constant state of chronic low‐grade inflammation which is characterized by activation and infiltration of pro‐inflammatory immune cells and a dysregulated production of high levels of pro‐inflammatory cytokines. This pro‐inflammatory milieu contributes to insulin resistance, type‐2 diabetes, cardiovascular disease, and other related co‐morbidities. The roles of the innate (macrophages, neutrophils, eosinophils, mast cells, NK cells, MAIT cells) and the adaptive (CD4 T cells, CD8 T cells, regulatory T cells, and B cells) immune responses and the roles of adipokines and cytokines in adipose tissue inflammation and obesity are discussed. An understanding of the crosstalk between the immune system and adipocytes may shed light in better treatment modalities for obesity and obesity‐related diseases.
- Full Text: false
- Date Issued: 2016
- Authors: Apostolopoulos, Vasso , De Courten, Maximilian P J , Stojanovska, Lily , Blatch, Gregory L , Tangalakis, Kathy , De Courten, Barbora
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66120 , vital:28905 , https://doi.org/10.1002/mnfr.201500272
- Description: publisher version , A number of approaches have been utilized in the prevention, management, and treatment of obesity, including, surgery, medication, diet, exercise, and overall lifestyle changes. Despite these interventions, the prevalence of obesity and the various disorders related to it is growing. In obesity, there is a constant state of chronic low‐grade inflammation which is characterized by activation and infiltration of pro‐inflammatory immune cells and a dysregulated production of high levels of pro‐inflammatory cytokines. This pro‐inflammatory milieu contributes to insulin resistance, type‐2 diabetes, cardiovascular disease, and other related co‐morbidities. The roles of the innate (macrophages, neutrophils, eosinophils, mast cells, NK cells, MAIT cells) and the adaptive (CD4 T cells, CD8 T cells, regulatory T cells, and B cells) immune responses and the roles of adipokines and cytokines in adipose tissue inflammation and obesity are discussed. An understanding of the crosstalk between the immune system and adipocytes may shed light in better treatment modalities for obesity and obesity‐related diseases.
- Full Text: false
- Date Issued: 2016
The effect of land-use on small mammal diversity inside and outside the Great Fish River Nature Reserve, Eastern Cape, South Africa
- Thondhlana, Gladman, Lagesse, Juliette V
- Authors: Thondhlana, Gladman , Lagesse, Juliette V
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67823 , vital:29150 , https://doi.org/10.1016/j.jaridenv.2016.03.006
- Description: Publisher version , This study investigated small mammal species diversity at 10 paired contrast sites along a fence line inside and outside the Great Fish River Nature Reserve (GFRNR), Eastern Cape, South Africa. The sites outside the GFRNR are used for subsistence land-based activities including livestock production and fuelwood harvesting. From 145 live captures, a total of 114 unique individuals of five small mammal species (four rodents and one elephant shrew) were recorded over 1170 trap nights. Average small mammal species diversity and abundance were significantly higher inside the reserve than outside. Human activities such as livestock grazing seemed to explain low levels of small mammal diversity and abundance at the communal sites. Vegetation variables showed a complex interplay with small mammal diversity. In general, high vegetation diversity had a positive influence on small mammal diversity though the influence of some environmental variables was species-dependent. We conclude that the GFRNR is effective in protecting small mammals but the findings raise questions around the influence of land use practices such as livestock grazing on biodiversity, especially given that local communities in South Africa are continuously seeking greater access to reserves for livestock grazing and other provisioning services.
- Full Text: false
- Date Issued: 2016
- Authors: Thondhlana, Gladman , Lagesse, Juliette V
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67823 , vital:29150 , https://doi.org/10.1016/j.jaridenv.2016.03.006
- Description: Publisher version , This study investigated small mammal species diversity at 10 paired contrast sites along a fence line inside and outside the Great Fish River Nature Reserve (GFRNR), Eastern Cape, South Africa. The sites outside the GFRNR are used for subsistence land-based activities including livestock production and fuelwood harvesting. From 145 live captures, a total of 114 unique individuals of five small mammal species (four rodents and one elephant shrew) were recorded over 1170 trap nights. Average small mammal species diversity and abundance were significantly higher inside the reserve than outside. Human activities such as livestock grazing seemed to explain low levels of small mammal diversity and abundance at the communal sites. Vegetation variables showed a complex interplay with small mammal diversity. In general, high vegetation diversity had a positive influence on small mammal diversity though the influence of some environmental variables was species-dependent. We conclude that the GFRNR is effective in protecting small mammals but the findings raise questions around the influence of land use practices such as livestock grazing on biodiversity, especially given that local communities in South Africa are continuously seeking greater access to reserves for livestock grazing and other provisioning services.
- Full Text: false
- Date Issued: 2016
The Guinea pigs of a problem-based learning curriculum
- Reddy, Sarasvathie, McKenna, Sioux
- Authors: Reddy, Sarasvathie , McKenna, Sioux
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66730 , vital:28987 , ISSN 1470-3300 , https://doi.org/10.1080/14703297.2014.959542
- Description: Publisher version , Participants in a study on learning the clinical aspects of medicine in a problem-based learning (PBL) curriculum repeatedly referred to themselves as ‘Guinea pigs’ at the mercy of a curriculum experiment. This article interrogates and problematises the ‘Guinea pig’ identity ascribed to and assumed by the first cohort of students who undertook a PBL curriculum. The article suggests that a range of issues may have come into play in the unfortunate events reported on here, and focuses on the participants’ reported experiences of marginalisation during their clinical education modules in the hospital wards. The impact of power differentials on identity formation was found to be exacerbated by the ‘Guinea pig’ characterisation.
- Full Text: false
- Date Issued: 2016
- Authors: Reddy, Sarasvathie , McKenna, Sioux
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66730 , vital:28987 , ISSN 1470-3300 , https://doi.org/10.1080/14703297.2014.959542
- Description: Publisher version , Participants in a study on learning the clinical aspects of medicine in a problem-based learning (PBL) curriculum repeatedly referred to themselves as ‘Guinea pigs’ at the mercy of a curriculum experiment. This article interrogates and problematises the ‘Guinea pig’ identity ascribed to and assumed by the first cohort of students who undertook a PBL curriculum. The article suggests that a range of issues may have come into play in the unfortunate events reported on here, and focuses on the participants’ reported experiences of marginalisation during their clinical education modules in the hospital wards. The impact of power differentials on identity formation was found to be exacerbated by the ‘Guinea pig’ characterisation.
- Full Text: false
- Date Issued: 2016
The impact of geographical origin of two strains of the herbivore, Eccritotarsus catarinensis, on several fitness traits in response to temperature
- Ismail, Mohannad, Brooks, Margot
- Authors: Ismail, Mohannad , Brooks, Margot
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66914 , vital:28999 , ISSN 0306-4565 , https://doi.org/10.1016/j.jtherbio.2016.07.008
- Description: Publisher version , Adaptation to temperature changes is vital to reduce adverse effects on individuals, and some may present phenotypic changes, which might be accompanied with physiological costs in fitness traits. The objective of this study was to determine whether the two strains of the herbivore Eccritotarsus catarinensis, a biological control agent against water hyacinth in South Africa, differ in their responses to temperature according to their geographical origin. We experimentally quantified the responses of the two strains, at three constant temperatures: 20 °C, 25 °C and 30 °C, using laboratory cultures that originated from Brazil and Peru, where climates differ. Reproductive output, egg hatching rate, sex ratio and longevity were recorded at each temperature. Fitness traits for both strains were significantly reduced at 30 °C compared with 25 °C and 20 °C in two successive generations. Nonetheless, Peruvian individuals continued their development at 30 °C, whereas Brazilian individuals that succeeded in emerging did not continue their development. In contrast, sex ratio was unaffected by temperature. The Peruvian strain of E. catarinensis presented different phenotypes depending on temperature and was more adapted to extreme high temperature than the Brazilian strain. The tropical origin of the population induces the insect to tolerate the extreme high temperature. We suggest that the Peruvian strain could be better suited for release to control water hyacinth in nature, particularly in regions where temperature is high.
- Full Text: false
- Date Issued: 2016
- Authors: Ismail, Mohannad , Brooks, Margot
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66914 , vital:28999 , ISSN 0306-4565 , https://doi.org/10.1016/j.jtherbio.2016.07.008
- Description: Publisher version , Adaptation to temperature changes is vital to reduce adverse effects on individuals, and some may present phenotypic changes, which might be accompanied with physiological costs in fitness traits. The objective of this study was to determine whether the two strains of the herbivore Eccritotarsus catarinensis, a biological control agent against water hyacinth in South Africa, differ in their responses to temperature according to their geographical origin. We experimentally quantified the responses of the two strains, at three constant temperatures: 20 °C, 25 °C and 30 °C, using laboratory cultures that originated from Brazil and Peru, where climates differ. Reproductive output, egg hatching rate, sex ratio and longevity were recorded at each temperature. Fitness traits for both strains were significantly reduced at 30 °C compared with 25 °C and 20 °C in two successive generations. Nonetheless, Peruvian individuals continued their development at 30 °C, whereas Brazilian individuals that succeeded in emerging did not continue their development. In contrast, sex ratio was unaffected by temperature. The Peruvian strain of E. catarinensis presented different phenotypes depending on temperature and was more adapted to extreme high temperature than the Brazilian strain. The tropical origin of the population induces the insect to tolerate the extreme high temperature. We suggest that the Peruvian strain could be better suited for release to control water hyacinth in nature, particularly in regions where temperature is high.
- Full Text: false
- Date Issued: 2016
The inhibitory effects of various substrate pre-treatment by-products and wash liquors on mannanolytic enzymes
- Malgas, Samkelo, Van Dyk, J Susan, Abboo, Sagaran, Pletschke, Brett I
- Authors: Malgas, Samkelo , Van Dyk, J Susan , Abboo, Sagaran , Pletschke, Brett I
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66156 , vital:28911 , https://doi.org/10.1016/j.molcatb.2015.11.014
- Description: publisher version , Biomass pre-treatment is essential for achieving high levels of bioconversion through increased accessibility of hydrolytic enzymes to hydrolysable carbohydrates. However, pre-treatment by-products, such as sugar and lignin degradation products, can negatively affect the performance of hydrolytic (mannanolytic) enzymes. In this study, two monomeric sugars, five sugar degradation products, five lignin derivatives and four liquors from biomass feedstocks pre-treated by different technologies, were evaluated for their inhibitory effects on mannanolytic enzymes (α-galactosidases, β-mannanases and β-mannosidases). Lignin derivatives elicited the greatest inhibitory effect on the mannanolytic enzymes, followed by organic acids and furan derivatives derived from sugar degradation. Lignin derivative inhibition appeared to be as a result of protein–phenolic complexation, leading to protein precipitating out of solution. The functional groups on the phenolic lignin derivatives appeared to be directly related to the ability of the phenolic to interfere with enzyme activity, with the phenolic containing the highest hydroxyl group content exhibiting the greatest inhibition. It was also demonstrated that various pre-treatment technologies render different pre-treatment soluble by-products which interact in various ways with the mannanolytic enzymes. The different types of biomass (i.e. different plant species) were also shown to release different by-products that interacted with the mannanolytic enzymes in a diverse manner even when the biomass was pre-treated using the same technology. Enzyme inhibition by pre-treatment by-products can be alleviated through the removal of these compounds prior to enzymatic hydrolysis to maximize enzyme activity.
- Full Text: false
- Date Issued: 2016
- Authors: Malgas, Samkelo , Van Dyk, J Susan , Abboo, Sagaran , Pletschke, Brett I
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66156 , vital:28911 , https://doi.org/10.1016/j.molcatb.2015.11.014
- Description: publisher version , Biomass pre-treatment is essential for achieving high levels of bioconversion through increased accessibility of hydrolytic enzymes to hydrolysable carbohydrates. However, pre-treatment by-products, such as sugar and lignin degradation products, can negatively affect the performance of hydrolytic (mannanolytic) enzymes. In this study, two monomeric sugars, five sugar degradation products, five lignin derivatives and four liquors from biomass feedstocks pre-treated by different technologies, were evaluated for their inhibitory effects on mannanolytic enzymes (α-galactosidases, β-mannanases and β-mannosidases). Lignin derivatives elicited the greatest inhibitory effect on the mannanolytic enzymes, followed by organic acids and furan derivatives derived from sugar degradation. Lignin derivative inhibition appeared to be as a result of protein–phenolic complexation, leading to protein precipitating out of solution. The functional groups on the phenolic lignin derivatives appeared to be directly related to the ability of the phenolic to interfere with enzyme activity, with the phenolic containing the highest hydroxyl group content exhibiting the greatest inhibition. It was also demonstrated that various pre-treatment technologies render different pre-treatment soluble by-products which interact in various ways with the mannanolytic enzymes. The different types of biomass (i.e. different plant species) were also shown to release different by-products that interacted with the mannanolytic enzymes in a diverse manner even when the biomass was pre-treated using the same technology. Enzyme inhibition by pre-treatment by-products can be alleviated through the removal of these compounds prior to enzymatic hydrolysis to maximize enzyme activity.
- Full Text: false
- Date Issued: 2016
The pattern-richness of graphical passwords
- Vorster, Johannes, Van Heerden, Renier, Irwin, Barry V W
- Authors: Vorster, Johannes , Van Heerden, Renier , Irwin, Barry V W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68322 , vital:29238 , https://doi.org/10.1109/ISSA.2016.7802931
- Description: Publisher version , Conventional (text-based) passwords have shown patterns such as variations on the username, or known passwords such as “password”, “admin” or “12345”. Patterns may similarly be detected in the use of Graphical passwords (GPs). The most significant such pattern - reported by many researchers - is hotspot clustering. This paper qualitatively analyses more than 200 graphical passwords for patterns other than the classically reported hotspots. The qualitative analysis finds that a significant percentage of passwords fall into a small set of patterns; patterns that can be used to form attack models against GPs. In counter action, these patterns can also be used to educate users so that future password selection is more secure. It is the hope that the outcome from this research will lead to improved behaviour and an enhancement in graphical password security.
- Full Text: false
- Date Issued: 2016
- Authors: Vorster, Johannes , Van Heerden, Renier , Irwin, Barry V W
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68322 , vital:29238 , https://doi.org/10.1109/ISSA.2016.7802931
- Description: Publisher version , Conventional (text-based) passwords have shown patterns such as variations on the username, or known passwords such as “password”, “admin” or “12345”. Patterns may similarly be detected in the use of Graphical passwords (GPs). The most significant such pattern - reported by many researchers - is hotspot clustering. This paper qualitatively analyses more than 200 graphical passwords for patterns other than the classically reported hotspots. The qualitative analysis finds that a significant percentage of passwords fall into a small set of patterns; patterns that can be used to form attack models against GPs. In counter action, these patterns can also be used to educate users so that future password selection is more secure. It is the hope that the outcome from this research will lead to improved behaviour and an enhancement in graphical password security.
- Full Text: false
- Date Issued: 2016
Thermoluminescence of kunzite: a study of kinetic processes and dosimetry characteristics
- Ogundare, F O, Alatishe, M A, Chithambo, Makaiko L, Costin, G
- Authors: Ogundare, F O , Alatishe, M A , Chithambo, Makaiko L , Costin, G
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124701 , vital:35650 , https://doi.org/10.1016/j.nimb.2016.02.059
- Description: Since the use of natural minerals for dating and dose reconstruction using luminescence techniques is well-established and always of interest, we present thermoluminescence characteristics of kunzite, a gem variety of spodumene. The chemical composition of the sample was determined using an Electron Probe MicroAnalyzer.
- Full Text: false
- Date Issued: 2016
- Authors: Ogundare, F O , Alatishe, M A , Chithambo, Makaiko L , Costin, G
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124701 , vital:35650 , https://doi.org/10.1016/j.nimb.2016.02.059
- Description: Since the use of natural minerals for dating and dose reconstruction using luminescence techniques is well-established and always of interest, we present thermoluminescence characteristics of kunzite, a gem variety of spodumene. The chemical composition of the sample was determined using an Electron Probe MicroAnalyzer.
- Full Text: false
- Date Issued: 2016
Time-resolved luminescence from quartz: an overview of contemporary developments and applications
- Chithambo, Makaiko L, Pagonis, Vasilis, Ankjærgaard, Christina
- Authors: Chithambo, Makaiko L , Pagonis, Vasilis , Ankjærgaard, Christina
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124743 , vital:35658 , https://doi.org/10.1016/j.physb.2015.10.014
- Description: Time-resolved optical stimulation of luminescence has become established as a key method for measurement of optically stimulated luminescence from quartz, feldspar and α-Al2O3:C, all materials of interest in dosimetry. The aim of time-resolved optical stimulation is to separate in time the stimulation and emission of luminescence. The luminescence is stimulated from a sample using a brief light pulse and the emission monitored during stimulation in the presence of scattered stimulating light or after pulsing, over photomultiplier noise only. Although the use of the method in retrospective dosimetry has been somewhat limited, the technique has been successfully applied to study mechanisms in the processes leading up to luminescence emission. The main means for this has been the temperature dependence of the luminescence intensity as well as the luminescence lifetimes determined from time-resolved luminescence spectra. In this paper we review some key developments in theory and applications to quartz including methods of evaluating lifetimes, techniques of evaluating kinetic parameters using both the dependence of luminescence intensity and lifetime on measurement temperature, and of lifetimes on annealing temperature. We then provide an overview of some notable applications such as separation of quartz signals from a quartz–feldspar admixture and the utility of the dynamic throughput, a measure of luminescence measured as a function of the pulse width. The paper concludes with some suggestions of areas where further exploration would advance understanding of dynamics of luminescence in quartz and help address some outstanding problems in its application.
- Full Text: false
- Date Issued: 2016
- Authors: Chithambo, Makaiko L , Pagonis, Vasilis , Ankjærgaard, Christina
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124743 , vital:35658 , https://doi.org/10.1016/j.physb.2015.10.014
- Description: Time-resolved optical stimulation of luminescence has become established as a key method for measurement of optically stimulated luminescence from quartz, feldspar and α-Al2O3:C, all materials of interest in dosimetry. The aim of time-resolved optical stimulation is to separate in time the stimulation and emission of luminescence. The luminescence is stimulated from a sample using a brief light pulse and the emission monitored during stimulation in the presence of scattered stimulating light or after pulsing, over photomultiplier noise only. Although the use of the method in retrospective dosimetry has been somewhat limited, the technique has been successfully applied to study mechanisms in the processes leading up to luminescence emission. The main means for this has been the temperature dependence of the luminescence intensity as well as the luminescence lifetimes determined from time-resolved luminescence spectra. In this paper we review some key developments in theory and applications to quartz including methods of evaluating lifetimes, techniques of evaluating kinetic parameters using both the dependence of luminescence intensity and lifetime on measurement temperature, and of lifetimes on annealing temperature. We then provide an overview of some notable applications such as separation of quartz signals from a quartz–feldspar admixture and the utility of the dynamic throughput, a measure of luminescence measured as a function of the pulse width. The paper concludes with some suggestions of areas where further exploration would advance understanding of dynamics of luminescence in quartz and help address some outstanding problems in its application.
- Full Text: false
- Date Issued: 2016
Trophic interactions in an austral temperate ephemeral pond inferred using stable isotope analysis
- Dalu, Tatenda, Weyl, Olaf L F, Froneman, P William, Wasserman, Ryan J
- Authors: Dalu, Tatenda , Weyl, Olaf L F , Froneman, P William , Wasserman, Ryan J
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68022 , vital:29185 , https://doi.org/10.1007/s10750-015-2533-5
- Description: Publisher version , Ephemeral ponds are vulnerable aquatic habitats which are difficult to protect given their dynamic nature and sensitivity to degradation during dry periods. Little information is available on these habitats in austral regions, with almost no information on food-web structure and complexity. The study aimed to assess trophic interactions among dominant organisms in an ephemeral pond food web, and investigate the importance of autochthonous and allochthonous carbon, using 13C and 15N isotopes. Results of the investigation suggest that the food web comprised four trophic levels, with the top predators being Notonectids (Notonecta sp.) and diving beetles (Cybister tripunctatus (Olivier)). Intermediary trophic levels comprised zooplankton (daphniids and copepodids), macroinvertebrates (e.g. micronectids and molluscs) and tadpoles. Generalist feeders dominated the higher trophic levels (>3) with specialists comprising the lower trophic levels (≤3). The consumers preferred autochthonous fine particulate organic matter, epiphyton and submerged macrophyte organic matter sources over allochthonous sources. Autochthonous organic matter was transferred to the food web via zooplankton and select macroinvertebrates including Micronecta sp. and Physa sp. The food-web structure within the pond appeared to reflect the secondary stage of trophic structural complexity in the evolution of ephemeral ponds over the course of their hydro-period.
- Full Text: false
- Date Issued: 2016
- Authors: Dalu, Tatenda , Weyl, Olaf L F , Froneman, P William , Wasserman, Ryan J
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68022 , vital:29185 , https://doi.org/10.1007/s10750-015-2533-5
- Description: Publisher version , Ephemeral ponds are vulnerable aquatic habitats which are difficult to protect given their dynamic nature and sensitivity to degradation during dry periods. Little information is available on these habitats in austral regions, with almost no information on food-web structure and complexity. The study aimed to assess trophic interactions among dominant organisms in an ephemeral pond food web, and investigate the importance of autochthonous and allochthonous carbon, using 13C and 15N isotopes. Results of the investigation suggest that the food web comprised four trophic levels, with the top predators being Notonectids (Notonecta sp.) and diving beetles (Cybister tripunctatus (Olivier)). Intermediary trophic levels comprised zooplankton (daphniids and copepodids), macroinvertebrates (e.g. micronectids and molluscs) and tadpoles. Generalist feeders dominated the higher trophic levels (>3) with specialists comprising the lower trophic levels (≤3). The consumers preferred autochthonous fine particulate organic matter, epiphyton and submerged macrophyte organic matter sources over allochthonous sources. Autochthonous organic matter was transferred to the food web via zooplankton and select macroinvertebrates including Micronecta sp. and Physa sp. The food-web structure within the pond appeared to reflect the secondary stage of trophic structural complexity in the evolution of ephemeral ponds over the course of their hydro-period.
- Full Text: false
- Date Issued: 2016
Vertebrate Biostratigraphy of the Witteberg Group and the Devonian-Carboniferous boundary in South Africa
- Authors: Gess, Robert W
- Date: 2016
- Language: English
- Type: text , boook chapter
- Identifier: http://hdl.handle.net/10962/73987 , vital:30248 , https://doi.org/10.1007/978-3-319-40859-0_13
- Description: Witteberg Group rocks are Late Devonian to Early Carboniferous in age. Comparison with Laurasian sea-level curves has correlated the earliest Carboniferous Tournasian transgression, with the argillaceous Kweekvlei Formation, overlying the arenaceous Witpoort Formation. The Devonian/Carboniferous boundary is globally characterised by a Mass Extinction which extinguished the entire grade of placoderm fish and radically reduced sarcopterygian and acanthodian diversity, preluding an Early Carboniferous radiation of actinopterygians. Analysis of Cape Supergroup biostratigraphy reveals that a fauna preservationally dominated by placoderms, sharks, and gyracanthid acanthodians may be traced from the Upper Bokkeveld Group through the Wagondrift Formation (Witteberg Group) to the Witpoort Formation, wherein it displays an increased diversity of placoderms, as well as sarcopterygians. Overlying strata contain no placoderms or sarcopterygians, but present are some relict sharks and acanthodians, and an increasing abundance of actinopterygians. This congruence confirms sea-level curve based age estimates of the Witteberg Group and the position of the Devonian/Carboniferous boundary.
- Full Text: false
- Date Issued: 2016
- Authors: Gess, Robert W
- Date: 2016
- Language: English
- Type: text , boook chapter
- Identifier: http://hdl.handle.net/10962/73987 , vital:30248 , https://doi.org/10.1007/978-3-319-40859-0_13
- Description: Witteberg Group rocks are Late Devonian to Early Carboniferous in age. Comparison with Laurasian sea-level curves has correlated the earliest Carboniferous Tournasian transgression, with the argillaceous Kweekvlei Formation, overlying the arenaceous Witpoort Formation. The Devonian/Carboniferous boundary is globally characterised by a Mass Extinction which extinguished the entire grade of placoderm fish and radically reduced sarcopterygian and acanthodian diversity, preluding an Early Carboniferous radiation of actinopterygians. Analysis of Cape Supergroup biostratigraphy reveals that a fauna preservationally dominated by placoderms, sharks, and gyracanthid acanthodians may be traced from the Upper Bokkeveld Group through the Wagondrift Formation (Witteberg Group) to the Witpoort Formation, wherein it displays an increased diversity of placoderms, as well as sarcopterygians. Overlying strata contain no placoderms or sarcopterygians, but present are some relict sharks and acanthodians, and an increasing abundance of actinopterygians. This congruence confirms sea-level curve based age estimates of the Witteberg Group and the position of the Devonian/Carboniferous boundary.
- Full Text: false
- Date Issued: 2016
Water footprint assessment of citrus production in South Africa: A case study of the Lower Sundays River Valley
- Munro, Samantha A, Fraser, Gavin C G, Snowball, Jeanette D, Pahlow, Markus
- Authors: Munro, Samantha A , Fraser, Gavin C G , Snowball, Jeanette D , Pahlow, Markus
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69240 , vital:29463 , https://doi.org/10.1016/j.jclepro.2016.06.142
- Description: Water footprint assessment is a developing method that is being increasingly applied to quantify water use, prioritise reductions, assess sustainability and provide information to achieve sustainable, efficient, and equitable water use. The objectives of this paper were to conduct a water footprint assessment of primary citrus production within the Lower Sundays River Valley in South Africa using local, high-resolution data and to examine indicators (water scarcity, pollution, efficiency, productivity and access) to determine the sustainability of blue, green and grey water footprints of a wet, dry and average year. Lemons were found to have the lowest blue and combined green-blue water footprint per ton of production across all climatic years, followed by soft citrus, valencias and navels. Valencias had the lowest, and navels the highest grey WF (relating to inorganic nitrogen). Lemons, despite their high crop water and fertiliser requirements, were regarded more economically efficient in comparison to valencias, soft citrus and navels, in that they provided higher net income and more employment hours per m3 of water in comparison to other citrus crops. In an average season, lemons generated approximately 39% more income per m3 of water than navels, despite navels being the dominant cultivar. Blue water consumption for citrus in the catchment was calculated to be 58.7 Mm3 for an average season and 89.2 Mm3 for a dry season. Due to an inter-basin transfer scheme, no physical water scarcity occurred, and both environmental and basic human needs are met. Water pollution levels related to nitrogen however, exceeded the assimilative capacity of the run-off in dry years. The area also experiences institutional and infrastructural scarcity and 14% of the population do not have access to piped water. Stakeholders and governments may use the results of water footprint assessments to determine the status of river basins, make evaluations for future water usage and the potential impacts of expanding agriculture and different management strategies. Including environmental and socio-economic indicators will also improve the integrity of water footprint assessments.
- Full Text: false
- Date Issued: 2016
- Authors: Munro, Samantha A , Fraser, Gavin C G , Snowball, Jeanette D , Pahlow, Markus
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69240 , vital:29463 , https://doi.org/10.1016/j.jclepro.2016.06.142
- Description: Water footprint assessment is a developing method that is being increasingly applied to quantify water use, prioritise reductions, assess sustainability and provide information to achieve sustainable, efficient, and equitable water use. The objectives of this paper were to conduct a water footprint assessment of primary citrus production within the Lower Sundays River Valley in South Africa using local, high-resolution data and to examine indicators (water scarcity, pollution, efficiency, productivity and access) to determine the sustainability of blue, green and grey water footprints of a wet, dry and average year. Lemons were found to have the lowest blue and combined green-blue water footprint per ton of production across all climatic years, followed by soft citrus, valencias and navels. Valencias had the lowest, and navels the highest grey WF (relating to inorganic nitrogen). Lemons, despite their high crop water and fertiliser requirements, were regarded more economically efficient in comparison to valencias, soft citrus and navels, in that they provided higher net income and more employment hours per m3 of water in comparison to other citrus crops. In an average season, lemons generated approximately 39% more income per m3 of water than navels, despite navels being the dominant cultivar. Blue water consumption for citrus in the catchment was calculated to be 58.7 Mm3 for an average season and 89.2 Mm3 for a dry season. Due to an inter-basin transfer scheme, no physical water scarcity occurred, and both environmental and basic human needs are met. Water pollution levels related to nitrogen however, exceeded the assimilative capacity of the run-off in dry years. The area also experiences institutional and infrastructural scarcity and 14% of the population do not have access to piped water. Stakeholders and governments may use the results of water footprint assessments to determine the status of river basins, make evaluations for future water usage and the potential impacts of expanding agriculture and different management strategies. Including environmental and socio-economic indicators will also improve the integrity of water footprint assessments.
- Full Text: false
- Date Issued: 2016
Ways of belonging: meanings of “Nature” among Xhosa-speaking township residents in South Africa
- Cocks, Michelle L, Alexander, Jamie K, Mogano, Lydia, Vetter, Susan M
- Authors: Cocks, Michelle L , Alexander, Jamie K , Mogano, Lydia , Vetter, Susan M
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66021 , vital:28877 , https://doi.org/10.2993/0278-0771-36.4.820
- Description: publisher version , The concept of biocultural diversity, originally used to describe indigenous people and their ways of using and managing natural resources, has more recently been applied within the urban context to understand the variability of interactions between humans and nature. Significant progress has been made internationally in acknowledging the need to preserve and maintain green spaces in urban environments. Current efforts to address the need for greening urban areas in South Africa primarily focus on the establishment and maintenance of botanical gardens and parks as well as various green belts within the urban landscape. South Africa's urban areas are overwhelmingly shaped by the historical segregation of space and stark disparities in wealth. The distribution, quality, and extent of urban green spaces reflect this. Many township dwellers do not have access to these amenities and their interactions with nature are thus usually constrained to access to municipal commonages. This article explores how areas of natural vegetation in municipal commonages on the outskirts of urban centers in South Africa continue to offer places of cultural, spiritual, and restorative importance to Xhosa-speaking township dwellers. A case study from Grahamstown, an urban center in the Eastern Cape with a population of around 80,000, illustrates how ability to access and move through such places contributes to people's well-being, identity formation, and shared heritage. A case is made for adopting a biocultural diversity approach to spatial planning and urban development within the South African context.
- Full Text: false
- Date Issued: 2016
- Authors: Cocks, Michelle L , Alexander, Jamie K , Mogano, Lydia , Vetter, Susan M
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66021 , vital:28877 , https://doi.org/10.2993/0278-0771-36.4.820
- Description: publisher version , The concept of biocultural diversity, originally used to describe indigenous people and their ways of using and managing natural resources, has more recently been applied within the urban context to understand the variability of interactions between humans and nature. Significant progress has been made internationally in acknowledging the need to preserve and maintain green spaces in urban environments. Current efforts to address the need for greening urban areas in South Africa primarily focus on the establishment and maintenance of botanical gardens and parks as well as various green belts within the urban landscape. South Africa's urban areas are overwhelmingly shaped by the historical segregation of space and stark disparities in wealth. The distribution, quality, and extent of urban green spaces reflect this. Many township dwellers do not have access to these amenities and their interactions with nature are thus usually constrained to access to municipal commonages. This article explores how areas of natural vegetation in municipal commonages on the outskirts of urban centers in South Africa continue to offer places of cultural, spiritual, and restorative importance to Xhosa-speaking township dwellers. A case study from Grahamstown, an urban center in the Eastern Cape with a population of around 80,000, illustrates how ability to access and move through such places contributes to people's well-being, identity formation, and shared heritage. A case is made for adopting a biocultural diversity approach to spatial planning and urban development within the South African context.
- Full Text: false
- Date Issued: 2016
What lies beneath: exploring the deeper purposes of feedback on student writing through considering disciplinary knowledge and knowers
- Van Heerden, Martina, Clarence, Sherran, Bharuthram, Sharita
- Authors: Van Heerden, Martina , Clarence, Sherran , Bharuthram, Sharita
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59856 , vital:27669 , https://doi.org/10.1080/02602938.2016.1212985
- Description: Feedback plays an integral role in students’ learning and development, as it is often the only personal communication that students have with tutors or lecturers about their own work. Yet, in spite of its integral role in student learning, there is disagreement between how students and tutors or lecturers perceive the pedagogic purpose of feedback. Central to this disagreement is the role that feedback has to play in ensuring that students produce the ‘right’ kinds of knowledge, and become the ‘right’ kinds of knowers within their disciplines. This paper argues that, in order to find common ground between students and tutors or lecturers on what feedback is for, and how to both give and use it effectively, we need to conceptualise disciplinary knowledge and knowers anew. We offer, as a useful starting point, the Specialisation dimension of Legitimation Code Theory as both practical theory and methodological tool for exploring knowledge and knowers in English Studies and Law as two illustrative cases. The paper concludes that this analysis offers lecturers and tutors a fresh understanding of the disciplinary knowledge and knower structures they work within and, relatedly, a clearer view of the work their feedback needs to do within these.
- Full Text: false
- Date Issued: 2016
- Authors: Van Heerden, Martina , Clarence, Sherran , Bharuthram, Sharita
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59856 , vital:27669 , https://doi.org/10.1080/02602938.2016.1212985
- Description: Feedback plays an integral role in students’ learning and development, as it is often the only personal communication that students have with tutors or lecturers about their own work. Yet, in spite of its integral role in student learning, there is disagreement between how students and tutors or lecturers perceive the pedagogic purpose of feedback. Central to this disagreement is the role that feedback has to play in ensuring that students produce the ‘right’ kinds of knowledge, and become the ‘right’ kinds of knowers within their disciplines. This paper argues that, in order to find common ground between students and tutors or lecturers on what feedback is for, and how to both give and use it effectively, we need to conceptualise disciplinary knowledge and knowers anew. We offer, as a useful starting point, the Specialisation dimension of Legitimation Code Theory as both practical theory and methodological tool for exploring knowledge and knowers in English Studies and Law as two illustrative cases. The paper concludes that this analysis offers lecturers and tutors a fresh understanding of the disciplinary knowledge and knower structures they work within and, relatedly, a clearer view of the work their feedback needs to do within these.
- Full Text: false
- Date Issued: 2016
A quantitative analysis of microplastic pollution along the south-eastern coastline of South Africa
- Nel, Holly A, Froneman, P William
- Authors: Nel, Holly A , Froneman, P William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68032 , vital:29187 , https://doi.org/10.1016/j.marpolbul.2015.09.043
- Description: Publisher version , The extent of microplastic pollution (< 5 mm) in the southern hemisphere, particularly southern Africa, is largely unknown. This study aimed to evaluate microplastic pollution along the south-eastern coastline of South Africa, looking at whether bays are characterised by higher microplastic densities than open stretches of coastline in both beach sediment and surf-zone water. Microplastic (mean ± standard error) densities in the beach sediment ranged between 688.9 ± 348.2 and 3308 ± 1449 particles·m− 2, while those in the water column varied between 257.9 ± 53.36 and 1215 ± 276.7 particles·m− 3. With few exceptions there were no significant spatial patterns in either the sediment or water column microplastic densities; with little differences in density between bays and the open coast (P > 0.05). These data indicate that the presence of microplastics were not associated with proximity to land-based sources or population density, but rather is governed by water circulation.
- Full Text: false
- Date Issued: 2015
- Authors: Nel, Holly A , Froneman, P William
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68032 , vital:29187 , https://doi.org/10.1016/j.marpolbul.2015.09.043
- Description: Publisher version , The extent of microplastic pollution (< 5 mm) in the southern hemisphere, particularly southern Africa, is largely unknown. This study aimed to evaluate microplastic pollution along the south-eastern coastline of South Africa, looking at whether bays are characterised by higher microplastic densities than open stretches of coastline in both beach sediment and surf-zone water. Microplastic (mean ± standard error) densities in the beach sediment ranged between 688.9 ± 348.2 and 3308 ± 1449 particles·m− 2, while those in the water column varied between 257.9 ± 53.36 and 1215 ± 276.7 particles·m− 3. With few exceptions there were no significant spatial patterns in either the sediment or water column microplastic densities; with little differences in density between bays and the open coast (P > 0.05). These data indicate that the presence of microplastics were not associated with proximity to land-based sources or population density, but rather is governed by water circulation.
- Full Text: false
- Date Issued: 2015
An assessment of chlorophyll-a concentration spatio-temporal variation using Landsat satellite data, in a small tropical reservoir
- Dalu, Tatenda, Dube, Timothy, Froneman, P William, Sachikonye, Mwazvita T B, Clegg, Bruce W, Nhiwatiwa, Tamuka
- Authors: Dalu, Tatenda , Dube, Timothy , Froneman, P William , Sachikonye, Mwazvita T B , Clegg, Bruce W , Nhiwatiwa, Tamuka
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68042 , vital:29189 , https://doi.org/10.1080/10106049.2015.1027292
- Description: Publisher version , Traditional approaches to monitoring aquatic systems are often limited by the need for data collection which often is time-consuming, expensive and non-continuous. The aim of the study was to map the spatio-temporal chlorophyll-a concentration changes in Malilangwe Reservoir, Zimbabwe as an indicator of phytoplankton biomass and trophic state when the reservoir was full (year 2000) and at its lowest capacity (year 2011), using readily available Landsat multispectral images. Medium-spatial resolution (30 m) Landsat multispectral Thematic Mapper TM 5 and ETM+ images for May to December 1999–2000 and 2010–2011 were used to derive chlorophyll-a concentrations. In situ measured chlorophyll-a and total suspended solids (TSS) concentrations for 2011 were employed to validate the Landsat chlorophyll-a and TSS estimates. The study results indicate that Landsat-derived chlorophyll-a and TSS estimates were comparable with field measurements. There was a considerable wet vs. dry season differences in total chlorophyll-a concentration, Secchi disc depth, TSS and turbidity within the reservoir. Using Permutational multivariate analyses of variance (PERMANOVA) analysis, there were significant differences (p < 0.0001) for chlorophyll-a concentration among sites, months and years whereas TSS was significant during the study months (p < 0.05). A strong positive significant correlation among both predicted TSS vs. chlorophyll-a and measured vs. predicted chlorophyll-a and TSS concentrations as well as an inverse relationship between reservoir chlorophyll-a concentrations and water level were found (p < 0.001 in all cases). In conclusion, total chlorophyll-a concentration in Malilangwe Reservoir was successfully derived from Landsat remote sensing data suggesting that the Landsat sensor is suitable for real-time monitoring over relatively short timescales and for small reservoirs. Satellite data can allow for surveying of chlorophyll-a concentration in aquatic ecosystems, thus, providing invaluable data in data scarce (limited on site ground measurements) environments.
- Full Text: false
- Date Issued: 2015
- Authors: Dalu, Tatenda , Dube, Timothy , Froneman, P William , Sachikonye, Mwazvita T B , Clegg, Bruce W , Nhiwatiwa, Tamuka
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68042 , vital:29189 , https://doi.org/10.1080/10106049.2015.1027292
- Description: Publisher version , Traditional approaches to monitoring aquatic systems are often limited by the need for data collection which often is time-consuming, expensive and non-continuous. The aim of the study was to map the spatio-temporal chlorophyll-a concentration changes in Malilangwe Reservoir, Zimbabwe as an indicator of phytoplankton biomass and trophic state when the reservoir was full (year 2000) and at its lowest capacity (year 2011), using readily available Landsat multispectral images. Medium-spatial resolution (30 m) Landsat multispectral Thematic Mapper TM 5 and ETM+ images for May to December 1999–2000 and 2010–2011 were used to derive chlorophyll-a concentrations. In situ measured chlorophyll-a and total suspended solids (TSS) concentrations for 2011 were employed to validate the Landsat chlorophyll-a and TSS estimates. The study results indicate that Landsat-derived chlorophyll-a and TSS estimates were comparable with field measurements. There was a considerable wet vs. dry season differences in total chlorophyll-a concentration, Secchi disc depth, TSS and turbidity within the reservoir. Using Permutational multivariate analyses of variance (PERMANOVA) analysis, there were significant differences (p < 0.0001) for chlorophyll-a concentration among sites, months and years whereas TSS was significant during the study months (p < 0.05). A strong positive significant correlation among both predicted TSS vs. chlorophyll-a and measured vs. predicted chlorophyll-a and TSS concentrations as well as an inverse relationship between reservoir chlorophyll-a concentrations and water level were found (p < 0.001 in all cases). In conclusion, total chlorophyll-a concentration in Malilangwe Reservoir was successfully derived from Landsat remote sensing data suggesting that the Landsat sensor is suitable for real-time monitoring over relatively short timescales and for small reservoirs. Satellite data can allow for surveying of chlorophyll-a concentration in aquatic ecosystems, thus, providing invaluable data in data scarce (limited on site ground measurements) environments.
- Full Text: false
- Date Issued: 2015
Cultural values of natural resources among the San people neighbouring Kgalagadi Transfrontier Park, South Africa
- Thondhlana, Gladman, Shackleton, Sheona E
- Authors: Thondhlana, Gladman , Shackleton, Sheona E
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67699 , vital:29131 , https://doi.org/10.1080/13549839.2013.818950
- Description: Publisher version , Globally, cultural values of natural resources are increasingly recognised as important for local natural resource management and conservation in and beyond parks. The tendency has been to focus on the direct-use rather than the cultural values and importance of natural resources. The cultural values underlying natural resources (directly or indirectly used) and various natural resource-based activities, and the implications for conservation, remain little explored. Drawing from household surveys, in-depth qualitative interviews, observations and secondary data, we explore the cultural significance of natural resources and different land-use practices among the San people bordering Kgalagadi Transfrontier Park in South Africa. Our findings illustrate that though cultural values are inextricably linked to resource use, they are not recognised by all community members. Further, cultural values arise from a diverse and sometimes conflicting array of values that punctuate individuals' lifestyles. A better understanding of context-specific cultural settings and the linkages between the cultural and material dimensions of resource use can lead to the development of interventions that can ensure effective conservation of both natural resources and culture.
- Full Text: false
- Date Issued: 2015
- Authors: Thondhlana, Gladman , Shackleton, Sheona E
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67699 , vital:29131 , https://doi.org/10.1080/13549839.2013.818950
- Description: Publisher version , Globally, cultural values of natural resources are increasingly recognised as important for local natural resource management and conservation in and beyond parks. The tendency has been to focus on the direct-use rather than the cultural values and importance of natural resources. The cultural values underlying natural resources (directly or indirectly used) and various natural resource-based activities, and the implications for conservation, remain little explored. Drawing from household surveys, in-depth qualitative interviews, observations and secondary data, we explore the cultural significance of natural resources and different land-use practices among the San people bordering Kgalagadi Transfrontier Park in South Africa. Our findings illustrate that though cultural values are inextricably linked to resource use, they are not recognised by all community members. Further, cultural values arise from a diverse and sometimes conflicting array of values that punctuate individuals' lifestyles. A better understanding of context-specific cultural settings and the linkages between the cultural and material dimensions of resource use can lead to the development of interventions that can ensure effective conservation of both natural resources and culture.
- Full Text: false
- Date Issued: 2015
Determinants of student satisfaction with campus residence life at a South African university
- Botha, Ferdi, Snowball, Jeanette D, De Klerk, Vivian A, Radloff, Sarah E
- Authors: Botha, Ferdi , Snowball, Jeanette D , De Klerk, Vivian A , Radloff, Sarah E
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/69277 , vital:29475 , https://doi.org/10.1007/978-3-319-15904-1_2
- Description: Factors outside the classroom can contribute to academic success as well as the achievement of important outcomes such as the appreciation of human diversity. Striving towards equality of residence life satisfaction is thus important for academic outcomes and for the development of well-functioning citizens. This study is based on the 2011 Quality of Residence Life (QoRL) Survey, conducted at a South African university, comprising roughly 2,000 respondents. The study investigates the association between satisfaction with QoRL and (i) residence milieu and characteristics, (ii) direct and indirect discrimination, (iii) perceptions of drug and alcohol issues in residence, (iv) safety, and (v) individual student characteristics. One main finding is that there are no significant differences in satisfaction with QoRL across racial and gender groups; suggesting significant progress in university transformation and equity goals. The general atmosphere and characteristics of residences are also important predictors of QoRL satisfaction.
- Full Text: false
- Date Issued: 2015
- Authors: Botha, Ferdi , Snowball, Jeanette D , De Klerk, Vivian A , Radloff, Sarah E
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/69277 , vital:29475 , https://doi.org/10.1007/978-3-319-15904-1_2
- Description: Factors outside the classroom can contribute to academic success as well as the achievement of important outcomes such as the appreciation of human diversity. Striving towards equality of residence life satisfaction is thus important for academic outcomes and for the development of well-functioning citizens. This study is based on the 2011 Quality of Residence Life (QoRL) Survey, conducted at a South African university, comprising roughly 2,000 respondents. The study investigates the association between satisfaction with QoRL and (i) residence milieu and characteristics, (ii) direct and indirect discrimination, (iii) perceptions of drug and alcohol issues in residence, (iv) safety, and (v) individual student characteristics. One main finding is that there are no significant differences in satisfaction with QoRL across racial and gender groups; suggesting significant progress in university transformation and equity goals. The general atmosphere and characteristics of residences are also important predictors of QoRL satisfaction.
- Full Text: false
- Date Issued: 2015