Integrating stomach content and stable isotope analyses to elucidate the feeding habits of non-native sharptooth catfish Clarias gariepinus
- Kadye, Wilbert T, Booth, Anthony J
- Authors: Kadye, Wilbert T , Booth, Anthony J
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124843 , vital:35703 , https://doi.10.1007/s10530-011-0116-6
- Description: Sharptooth catfish Clarias gariepinus was introduced into the Eastern Cape Province, South Africa, in 1976 and there are concerns about its possible negative impacts on native biota. This study investigated its trophic impact by examining its feeding habits. Stomach content and stable isotope analyses were compared from three localities—the Great Fish River, Sundays River and Glen Melville Dam. Stomach content analysis indicated a catholic diet dominated by fish particularly in all localities.Spatially, however, the diets revealed differences based on the dominance of macrophytes that were only present in the rivers, and aquatic invertebrates that appeared more diverse within the Great Fish River compared to other localities. By contrast, stable isotopes revealed a more generalised feeding pattern with no clear dominance of particular prey. Stable isotopes further showed that the catfish was a complex predator, with large catfish being top predators whereas smaller size groups appeared to feed lower in the food chain. An ontogenetic shift in diet was evident, with small fish predominantly consuming aquatic invertebrates and shifting towards fish with increasing size. High dietary overlap suggests the potential risk associated catfish feeding, especially the potential of piscivory by small catfish that are more likely to persist in shallow and marginal where endangered indigenous minnows occur. The alteration of environmental conditions, especially flow by inter basin water transfer (IBWT) schemes, was inferred to have had a probable influence its invasion success. Occurrence of other invaders, which was facilitated by the IBWT together with the catfish, posits the risk of invasion meltdown within the study systems.
- Full Text:
- Date Issued: 2012
- Authors: Kadye, Wilbert T , Booth, Anthony J
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124843 , vital:35703 , https://doi.10.1007/s10530-011-0116-6
- Description: Sharptooth catfish Clarias gariepinus was introduced into the Eastern Cape Province, South Africa, in 1976 and there are concerns about its possible negative impacts on native biota. This study investigated its trophic impact by examining its feeding habits. Stomach content and stable isotope analyses were compared from three localities—the Great Fish River, Sundays River and Glen Melville Dam. Stomach content analysis indicated a catholic diet dominated by fish particularly in all localities.Spatially, however, the diets revealed differences based on the dominance of macrophytes that were only present in the rivers, and aquatic invertebrates that appeared more diverse within the Great Fish River compared to other localities. By contrast, stable isotopes revealed a more generalised feeding pattern with no clear dominance of particular prey. Stable isotopes further showed that the catfish was a complex predator, with large catfish being top predators whereas smaller size groups appeared to feed lower in the food chain. An ontogenetic shift in diet was evident, with small fish predominantly consuming aquatic invertebrates and shifting towards fish with increasing size. High dietary overlap suggests the potential risk associated catfish feeding, especially the potential of piscivory by small catfish that are more likely to persist in shallow and marginal where endangered indigenous minnows occur. The alteration of environmental conditions, especially flow by inter basin water transfer (IBWT) schemes, was inferred to have had a probable influence its invasion success. Occurrence of other invaders, which was facilitated by the IBWT together with the catfish, posits the risk of invasion meltdown within the study systems.
- Full Text:
- Date Issued: 2012
The Privacy Paradox applies to IoT devices too: a Saudi Arabian study
- Aleisa, Noura, Renaud, Karen, Bongiovanni, Ivano
- Authors: Aleisa, Noura , Renaud, Karen , Bongiovanni, Ivano
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158350 , vital:40176 , https://doi.org/10.1016/j.cose.2020.101897
- Description: The “privacy paradox” is the term used to describe the disconnect between self-reported privacy value attributions and actions actually taken to protect and preserve personal privacy. This phenomenon has been investigated in a number of domains and we extend the body of research with an investigation in the IoT domain. We presented participants with evidence of a specific IoT device’s (smart plug) privacy violations and then measured changes in privacy concerns and trust, as well as uptake of a range of behavioural responses.
- Full Text:
- Date Issued: 2020
- Authors: Aleisa, Noura , Renaud, Karen , Bongiovanni, Ivano
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158350 , vital:40176 , https://doi.org/10.1016/j.cose.2020.101897
- Description: The “privacy paradox” is the term used to describe the disconnect between self-reported privacy value attributions and actions actually taken to protect and preserve personal privacy. This phenomenon has been investigated in a number of domains and we extend the body of research with an investigation in the IoT domain. We presented participants with evidence of a specific IoT device’s (smart plug) privacy violations and then measured changes in privacy concerns and trust, as well as uptake of a range of behavioural responses.
- Full Text:
- Date Issued: 2020
Reform in defence of sovereignty: South Africa in the UN Security Council, 2007–2008
- Authors: Bischoff, Paul, 1954-
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161431 , vital:40626 , https://0-doi.org.wam.seals.ac.za/10.1177/000203970904400205
- Description: After 1994, South Africa became the sine qua non of an internationalist state, willing to promote cooperation amongst a plurality of actors, believing common interests to be more important than their differences. This raised the hopes of constitutionalists, and those who believed in the expansion of a liberal democratic peace. South Africa has acted out two seemingly contradictory roles: those of a reformer and those of a conserver. By 2007–2008 she had shifted towards the latter, conservative-reformist position. Thus, South Africa's voting record at the General Assembly expressed her overriding concern to regionalise African issues and minimise the US and the West shaping political events. This brought her foreign policy into sharper relief. But while in some sense successful, it came at a price: a controversy about her surrendering her internationalism and principles on human rights for African unity and traditional sovereignty. But it also marked the arrival of South Africa in the world of international Realpolitik.
- Full Text:
- Date Issued: 2009
- Authors: Bischoff, Paul, 1954-
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161431 , vital:40626 , https://0-doi.org.wam.seals.ac.za/10.1177/000203970904400205
- Description: After 1994, South Africa became the sine qua non of an internationalist state, willing to promote cooperation amongst a plurality of actors, believing common interests to be more important than their differences. This raised the hopes of constitutionalists, and those who believed in the expansion of a liberal democratic peace. South Africa has acted out two seemingly contradictory roles: those of a reformer and those of a conserver. By 2007–2008 she had shifted towards the latter, conservative-reformist position. Thus, South Africa's voting record at the General Assembly expressed her overriding concern to regionalise African issues and minimise the US and the West shaping political events. This brought her foreign policy into sharper relief. But while in some sense successful, it came at a price: a controversy about her surrendering her internationalism and principles on human rights for African unity and traditional sovereignty. But it also marked the arrival of South Africa in the world of international Realpolitik.
- Full Text:
- Date Issued: 2009
The Educational Journal
- Date: 1982-05
- Subjects: Education –- South Africa , South Africa -- Politics and government , Government, Resistance to -- South Africa
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/36006 , vital:33879 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa.
- Full Text: false
- Date Issued: 1982-05
- Date: 1982-05
- Subjects: Education –- South Africa , South Africa -- Politics and government , Government, Resistance to -- South Africa
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/36006 , vital:33879 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa.
- Full Text: false
- Date Issued: 1982-05
Olive Schreiner in Rhodesia: an episode in a biography
- Walters, Paul S, Fogg, W Jeremy M
- Authors: Walters, Paul S , Fogg, W Jeremy M
- Date: 2007
- Language: English
- Type: text , Article
- Identifier: vital:6123 , http://hdl.handle.net/10962/d1004707
- Description: Readers of biographies of Olive Schreiner - except for the pioneering work of Vera Buchanan-Gould (see 1948, 198-99) - could be forgiven for doubting whether Olive Schreiner ever was in Rhodesia. Although her husband's edition of her Letters includes three which cover this journey (Cronwright-Schreiner 1924a), he makes no mention of it in his Life (1924), and it is not touched on either in First and Scott (1980) or in Stanley's impressive biographical chapter (2002). Arguably, it does nothing to alter the by now well-established outlines of Olive Schreiner's life; yet, as we shall see, the visit itself might have meant the premature end of that life. Moreover, it documents Schreiner's visit to two sites of immense importance to her : the 'Hanging Tree' in Bulawayo which features in the (deliberately shocking) photographic frontispiece to the first edition of Trooper Peter Halket of Mashonaland (1897), and, secondly, Cecil Rhodes's grave in the Matopos. In just over a decade (13 Aug. 1921), she too would lie in her chosen mountaintop tomb.
- Full Text:
- Date Issued: 2007
- Authors: Walters, Paul S , Fogg, W Jeremy M
- Date: 2007
- Language: English
- Type: text , Article
- Identifier: vital:6123 , http://hdl.handle.net/10962/d1004707
- Description: Readers of biographies of Olive Schreiner - except for the pioneering work of Vera Buchanan-Gould (see 1948, 198-99) - could be forgiven for doubting whether Olive Schreiner ever was in Rhodesia. Although her husband's edition of her Letters includes three which cover this journey (Cronwright-Schreiner 1924a), he makes no mention of it in his Life (1924), and it is not touched on either in First and Scott (1980) or in Stanley's impressive biographical chapter (2002). Arguably, it does nothing to alter the by now well-established outlines of Olive Schreiner's life; yet, as we shall see, the visit itself might have meant the premature end of that life. Moreover, it documents Schreiner's visit to two sites of immense importance to her : the 'Hanging Tree' in Bulawayo which features in the (deliberately shocking) photographic frontispiece to the first edition of Trooper Peter Halket of Mashonaland (1897), and, secondly, Cecil Rhodes's grave in the Matopos. In just over a decade (13 Aug. 1921), she too would lie in her chosen mountaintop tomb.
- Full Text:
- Date Issued: 2007
Figuring maternity: Christine Dixie's Parturient Prospects
- Authors: Schmahmann, Brenda
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147748 , vital:38667 , https://doi.org/10.1080/00043389.2007.11877068
- Description: The Interior, Birthing Tray and Parturition are three sub-sections of a project entitled Parturient Prospects that artist Christine Dixie began in 2005, when she was pregnant with her second child, and completed by the end of 2006. In Parturient Prospects, the author reveals, Dixie situates her experiences against Western discourses, especially images from early modern Europe. Focusing on the ways in which visual representations construct woman as ‘other’, Dixie invokes reference to not only representations of birth and maternity but also religious, medical and geographical images.
- Full Text:
- Date Issued: 2017
- Authors: Schmahmann, Brenda
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147748 , vital:38667 , https://doi.org/10.1080/00043389.2007.11877068
- Description: The Interior, Birthing Tray and Parturition are three sub-sections of a project entitled Parturient Prospects that artist Christine Dixie began in 2005, when she was pregnant with her second child, and completed by the end of 2006. In Parturient Prospects, the author reveals, Dixie situates her experiences against Western discourses, especially images from early modern Europe. Focusing on the ways in which visual representations construct woman as ‘other’, Dixie invokes reference to not only representations of birth and maternity but also religious, medical and geographical images.
- Full Text:
- Date Issued: 2017
"My novel, Hill of Fools"
- Peteni, R L, Wright, Laurence
- Authors: Peteni, R L , Wright, Laurence
- Date: 2004
- Language: English
- Type: text , article
- Identifier: vital:7038 , http://hdl.handle.net/10962/d1007376 , http://hdl.handle.net/10520/EJC47869
- Description: preprint , R.L. Peteni - 'There is a tendency in human beings to pay no heed to events in small remote areas. They would rather concern themselves only with those events which make headlines, with political upheavals and industrial conflicts centred in large metropolitan regions. Yet there is always drama and human conflict in the humblest rural village. In selecting a pastoral theme and small fictitious villages in an obscure corner of Keiskammahoek as the setting of the novel, I had an ironic intention. Themes illustrated in these obscure villages would, I believed, have more universal application than they would if I had selected a larger centre, identifiable personages and known political trends. I did not want anybody to sit back, complacent, feeling that the spotlight was on Lennox Sebe’s Ciskei alone, or Kaiser Matanzima’s Transkei, or John Vorster’s apartheid South Africa. The spotlight is on the Ciskei, yes, on Transkei, on South Africa, on any other country where public life and personal relationships are bedevilled by tribalism or racialism or any form of sectionalism.
- Full Text:
- Date Issued: 2004
- Authors: Peteni, R L , Wright, Laurence
- Date: 2004
- Language: English
- Type: text , article
- Identifier: vital:7038 , http://hdl.handle.net/10962/d1007376 , http://hdl.handle.net/10520/EJC47869
- Description: preprint , R.L. Peteni - 'There is a tendency in human beings to pay no heed to events in small remote areas. They would rather concern themselves only with those events which make headlines, with political upheavals and industrial conflicts centred in large metropolitan regions. Yet there is always drama and human conflict in the humblest rural village. In selecting a pastoral theme and small fictitious villages in an obscure corner of Keiskammahoek as the setting of the novel, I had an ironic intention. Themes illustrated in these obscure villages would, I believed, have more universal application than they would if I had selected a larger centre, identifiable personages and known political trends. I did not want anybody to sit back, complacent, feeling that the spotlight was on Lennox Sebe’s Ciskei alone, or Kaiser Matanzima’s Transkei, or John Vorster’s apartheid South Africa. The spotlight is on the Ciskei, yes, on Transkei, on South Africa, on any other country where public life and personal relationships are bedevilled by tribalism or racialism or any form of sectionalism.
- Full Text:
- Date Issued: 2004
Women Leadership in COSATU
- NALEDI
- Authors: NALEDI
- Date: 1999
- Subjects: NALEDI
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/151630 , vital:39155
- Description: The aim of this paper is to provide updated figures on women's representation in leadership structures in COSATU. These figures enable the federation to review progress and to set targets for women’s leadership, as resolved in the 1997 COSATU Congress. The paper provides the most recent statistics (for 1998) on women’s leadership in COSATU at regional and national level. The intention of this report was to focus on collecting the actual figures and is therefore confined to a more quantitative (statistical) reflection on women’s leadership. It will be valuable to embark on further research that examines the qualitative aspects, in other words, women’s experiences of leadership.
- Full Text:
- Date Issued: 1999
- Authors: NALEDI
- Date: 1999
- Subjects: NALEDI
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/151630 , vital:39155
- Description: The aim of this paper is to provide updated figures on women's representation in leadership structures in COSATU. These figures enable the federation to review progress and to set targets for women’s leadership, as resolved in the 1997 COSATU Congress. The paper provides the most recent statistics (for 1998) on women’s leadership in COSATU at regional and national level. The intention of this report was to focus on collecting the actual figures and is therefore confined to a more quantitative (statistical) reflection on women’s leadership. It will be valuable to embark on further research that examines the qualitative aspects, in other words, women’s experiences of leadership.
- Full Text:
- Date Issued: 1999
What about the queers?: the institutional culture of heteronormativity and its implications for queer staff and students
- Authors: Donaldson, Natalie
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/142051 , vital:38045 , ISBN 9781869142902 , https://books.google.co.za/books?id=49o8rgEACAAJanddq=Being+at+home:+Race,+institutional+culture+and+transformation+at+South+African+higher+education+institutionandhl=enandsa=Xandved=0ahUKEwiPgsa6mpjjAhXNN8AKHbNwAtoQ6AEIKDAA
- Description: This edited work has gathered together contributions on how to transform universities in South Africa; as many are struggling to shift their institutional culture. In a South African context, transformation means to attempt to change higher education institutions such that they no longer reflect the values promoted by apartheid but rather reflect the values embodied in South Africa's 1996 Constitution. Institutional culture is the main subject for discussion in this book. In order to transform South Africa's universities, the contributors begin by analyzing the idea of what a university is, and relatedly, what its ideal aims are. A second theme is to understand what institutional culture is and how it functions. Moreover, transformation cannot occur without transforming the broader cultures of which they are a part. Related to this theme is a general concern about how contemporary moves towards the instrumentalization of higher education affect the ability to transform institutions. These institutions are being pushed to conform to goals that are outside the traditional idea of a university, such as concerns that universities are being 'bureaucratized' and becoming corporations, instead of a place of learning open to all. In conclusion it can be said that the contemporary South African academic community has an opportunity to recreate itself as the end of apartheid created space for engaging in transformative epistemic projects. The transformation of the tertiary sector entails a transformation of institutional cultures.
- Full Text:
- Date Issued: 2015
- Authors: Donaldson, Natalie
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/142051 , vital:38045 , ISBN 9781869142902 , https://books.google.co.za/books?id=49o8rgEACAAJanddq=Being+at+home:+Race,+institutional+culture+and+transformation+at+South+African+higher+education+institutionandhl=enandsa=Xandved=0ahUKEwiPgsa6mpjjAhXNN8AKHbNwAtoQ6AEIKDAA
- Description: This edited work has gathered together contributions on how to transform universities in South Africa; as many are struggling to shift their institutional culture. In a South African context, transformation means to attempt to change higher education institutions such that they no longer reflect the values promoted by apartheid but rather reflect the values embodied in South Africa's 1996 Constitution. Institutional culture is the main subject for discussion in this book. In order to transform South Africa's universities, the contributors begin by analyzing the idea of what a university is, and relatedly, what its ideal aims are. A second theme is to understand what institutional culture is and how it functions. Moreover, transformation cannot occur without transforming the broader cultures of which they are a part. Related to this theme is a general concern about how contemporary moves towards the instrumentalization of higher education affect the ability to transform institutions. These institutions are being pushed to conform to goals that are outside the traditional idea of a university, such as concerns that universities are being 'bureaucratized' and becoming corporations, instead of a place of learning open to all. In conclusion it can be said that the contemporary South African academic community has an opportunity to recreate itself as the end of apartheid created space for engaging in transformative epistemic projects. The transformation of the tertiary sector entails a transformation of institutional cultures.
- Full Text:
- Date Issued: 2015
Steam activation, characterisation and adsorption studies of activated carbon from maize tassels.
- Olorundare, O F, Msagati, Titus A, Krause, Rui W M, Okonkwo, J O, Mamba, Bhekie B
- Authors: Olorundare, O F , Msagati, Titus A , Krause, Rui W M , Okonkwo, J O , Mamba, Bhekie B
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123847 , vital:35507 , https://doi.org/10.1080/02757540.2013.877001
- Description: In this paper, steam-produced activated carbon (STAC) from maize tassel (MT) was evaluated for its ability to remove basic dye (methylene blue MB) from aqueous solution in a batch adsorption process. The equilibrium experiments were conducted in the range of 50–300 mg/L initial MB concentrations at 30°C, for effect of pH, adsorbent dosage and contact time. The experimental data were analysed by Langmuir, Freundlich and Temkin isotherm models of adsorption. Freundlich adsorption isotherm was found to have highest value of R2(R2=0.97) compared to other models of Langmuir and Temkin having (0.96 and 0.95 respectively). STAC has a high adsorptive capacity for MB dye (200 mg/g) and also showed favourable adsorption for the dye with the separation factor for the dye-activated carbon system. The kinetic data obtained were analysed using pseudo first-order kinetic equation and pseudo second-order kinetic equation. The experimental data fitted well into pseudo second-order kinetic equation, as demonstrated by the high value of R2.
- Full Text:
- Date Issued: 2014
- Authors: Olorundare, O F , Msagati, Titus A , Krause, Rui W M , Okonkwo, J O , Mamba, Bhekie B
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123847 , vital:35507 , https://doi.org/10.1080/02757540.2013.877001
- Description: In this paper, steam-produced activated carbon (STAC) from maize tassel (MT) was evaluated for its ability to remove basic dye (methylene blue MB) from aqueous solution in a batch adsorption process. The equilibrium experiments were conducted in the range of 50–300 mg/L initial MB concentrations at 30°C, for effect of pH, adsorbent dosage and contact time. The experimental data were analysed by Langmuir, Freundlich and Temkin isotherm models of adsorption. Freundlich adsorption isotherm was found to have highest value of R2(R2=0.97) compared to other models of Langmuir and Temkin having (0.96 and 0.95 respectively). STAC has a high adsorptive capacity for MB dye (200 mg/g) and also showed favourable adsorption for the dye with the separation factor for the dye-activated carbon system. The kinetic data obtained were analysed using pseudo first-order kinetic equation and pseudo second-order kinetic equation. The experimental data fitted well into pseudo second-order kinetic equation, as demonstrated by the high value of R2.
- Full Text:
- Date Issued: 2014
Strategic plan for the restructuring of the textile and clothing industries
- SACTWU
- Authors: SACTWU
- Date: 1995
- Subjects: SACTWU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/176444 , vital:42695
- Description: The achievement of international competitiveness within a 10 year time frame with: a minimisation of the loss of job opportunities in the textile industry, the growth and net creation of jobs in the clothing sector, both formal and informal, successful, in general, export-orientated textile and clothing industries, the acceptance by the industries of a greater responsibility for their own future by lessening their dependence on government by improving productivity through human resource development, work organisation and upgraded technology; a conscious move out of the lower end of the market but simultaneous efforts to retain these activities within the region; and a competitive environment where everyone gains, including the consumer, by making basic goods more affordable.
- Full Text:
- Date Issued: 1995
- Authors: SACTWU
- Date: 1995
- Subjects: SACTWU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/176444 , vital:42695
- Description: The achievement of international competitiveness within a 10 year time frame with: a minimisation of the loss of job opportunities in the textile industry, the growth and net creation of jobs in the clothing sector, both formal and informal, successful, in general, export-orientated textile and clothing industries, the acceptance by the industries of a greater responsibility for their own future by lessening their dependence on government by improving productivity through human resource development, work organisation and upgraded technology; a conscious move out of the lower end of the market but simultaneous efforts to retain these activities within the region; and a competitive environment where everyone gains, including the consumer, by making basic goods more affordable.
- Full Text:
- Date Issued: 1995
Fatty acid profiles reveal temporal and spatial differentiation in diets within and among syntopic rocky shore suspension-feeders
- Vermeulen, I, Richoux, N.B, Froneman, Pierre William
- Authors: Vermeulen, I , Richoux, N.B , Froneman, Pierre William
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124269 , vital:35582 , http://dx.doi.10.3354/meps10581
- Description: Regional and temporal variations in the diets of rocky shore suspension-feeders (the volcano barnacle Tetraclita serrata, the brown mussel Perna perna and the reef-building poly- chaete Gunnarea gaimardi) were assessed using fatty acid profiling. Specimens were collected up-current and down-current of a river mouth in 2 coastal regions ~50 km apart along southeast- ern South Africa during March and July of 2009. One of the rivers represents a marine-dominated system, and the other a freshwater-dominated system. Our aims were to assess any dietary differences among the 3 suspension-feeders, spatial changes in diet within each species (at regional and local scales—50 and 15 km, respectively), and temporal changes in diet within each species. Fatty acid profiles clearly distinguished the species, with barnacles characterised by dinoflagellate and zooplankton-associated fatty acids; polychaetes, by diatom-associated fatty acids; and mussels, by a combination of mixed phytoplankton and mollusc-specific fatty acids (non-methylene interrupted). These interspecific differences probably arose in part from the contrasting feeding mechanisms employed. The distinctions in diet contribute to ecological partitioning of the sus- pended food within a highly competitive habitat. Regional- and local-scale intraspecific differences in diets were minimal to absent, but temporal distinctions in intraspecific diets were dominant features in the data set, confirming that the trophic environment for suspension-feeders can change markedly throughout a year.
- Full Text: false
- Date Issued: 2014
- Authors: Vermeulen, I , Richoux, N.B , Froneman, Pierre William
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124269 , vital:35582 , http://dx.doi.10.3354/meps10581
- Description: Regional and temporal variations in the diets of rocky shore suspension-feeders (the volcano barnacle Tetraclita serrata, the brown mussel Perna perna and the reef-building poly- chaete Gunnarea gaimardi) were assessed using fatty acid profiling. Specimens were collected up-current and down-current of a river mouth in 2 coastal regions ~50 km apart along southeast- ern South Africa during March and July of 2009. One of the rivers represents a marine-dominated system, and the other a freshwater-dominated system. Our aims were to assess any dietary differences among the 3 suspension-feeders, spatial changes in diet within each species (at regional and local scales—50 and 15 km, respectively), and temporal changes in diet within each species. Fatty acid profiles clearly distinguished the species, with barnacles characterised by dinoflagellate and zooplankton-associated fatty acids; polychaetes, by diatom-associated fatty acids; and mussels, by a combination of mixed phytoplankton and mollusc-specific fatty acids (non-methylene interrupted). These interspecific differences probably arose in part from the contrasting feeding mechanisms employed. The distinctions in diet contribute to ecological partitioning of the sus- pended food within a highly competitive habitat. Regional- and local-scale intraspecific differences in diets were minimal to absent, but temporal distinctions in intraspecific diets were dominant features in the data set, confirming that the trophic environment for suspension-feeders can change markedly throughout a year.
- Full Text: false
- Date Issued: 2014
Learning (dis)advantage in matriculation language classrooms
- Authors: Prinsloo, J
- Date: 2006
- Language: English
- Type: Book chapter
- Identifier: vital:529 , http://hdl.handle.net/10962/d1008479
- Description: During the first decade of democracy in South Africa formal education has been characterised by sweeping policy shifts and consequent curriculum revision. In many instances, curricular revisions are criticised for failing to effect desired or anticipated changes. In this chapter the focus is on the language curriculum and the associated practices, or what I refer to as the literacy practices that have become naturalised over decades and persist in the present. The argument that is presented here contends that to enable effective change, it is essential to understand better what has historically constituted literacy practices and to recognise their social, cultural and economic implications.
- Full Text:
- Date Issued: 2006
- Authors: Prinsloo, J
- Date: 2006
- Language: English
- Type: Book chapter
- Identifier: vital:529 , http://hdl.handle.net/10962/d1008479
- Description: During the first decade of democracy in South Africa formal education has been characterised by sweeping policy shifts and consequent curriculum revision. In many instances, curricular revisions are criticised for failing to effect desired or anticipated changes. In this chapter the focus is on the language curriculum and the associated practices, or what I refer to as the literacy practices that have become naturalised over decades and persist in the present. The argument that is presented here contends that to enable effective change, it is essential to understand better what has historically constituted literacy practices and to recognise their social, cultural and economic implications.
- Full Text:
- Date Issued: 2006
Fishes of the deep demersal habitat at Ngazidja (Grand Comoro) Island, Western Indian Ocean
- Heemstra, P C, Hissmann, K, Fricke, H
- Authors: Heemstra, P C , Hissmann, K , Fricke, H
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:7158 , http://hdl.handle.net/10962/d1011885
- Description: Underwater observations of the coelacanth, Latimeria chalumnae Smith, 1939, from a research submersible provided opportunities to study the deep demersal fish fauna at the Comoro Islands. The demersal habitat in depths of 150–400 m at the volcanic island of Ngazidja is low in fish diversity and biomass, compared with the shallow-water coral reef habitat of Ngazidja or the deep demersal habitats of other localities in the Indo-Pacific region. The resident deep demersal fish fauna at Ngazidja is dominated by the coelacanth, an ancient predator that is specially adapted for this low-energy environment. Other large fish predators are scarce in this environment, because of the heavy fishing pressure from local fishermen. Eighty-nine fish taxa (including 65 recognizable species) were recorded from videotapes, photographs, visual observations, fishermen’s catches and ancillary attempts to sample the fish fauna with baited fish traps, gill nets, and hook and line. Although no coelacanth feeding events were seen, seven fish species are known from coelacanth stomach contents, and 64 other fish species in this habitat are considered potential prey of this dominant predator.
- Full Text:
- Date Issued: 2006
- Authors: Heemstra, P C , Hissmann, K , Fricke, H
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:7158 , http://hdl.handle.net/10962/d1011885
- Description: Underwater observations of the coelacanth, Latimeria chalumnae Smith, 1939, from a research submersible provided opportunities to study the deep demersal fish fauna at the Comoro Islands. The demersal habitat in depths of 150–400 m at the volcanic island of Ngazidja is low in fish diversity and biomass, compared with the shallow-water coral reef habitat of Ngazidja or the deep demersal habitats of other localities in the Indo-Pacific region. The resident deep demersal fish fauna at Ngazidja is dominated by the coelacanth, an ancient predator that is specially adapted for this low-energy environment. Other large fish predators are scarce in this environment, because of the heavy fishing pressure from local fishermen. Eighty-nine fish taxa (including 65 recognizable species) were recorded from videotapes, photographs, visual observations, fishermen’s catches and ancillary attempts to sample the fish fauna with baited fish traps, gill nets, and hook and line. Although no coelacanth feeding events were seen, seven fish species are known from coelacanth stomach contents, and 64 other fish species in this habitat are considered potential prey of this dominant predator.
- Full Text:
- Date Issued: 2006
Comparing the fish assemblages and food web structures of large floodplain rivers
- Taylor, Geraldine C, Weyl, Olaf L F, Hill, Jaclyn M, Peel, Richard A, Hay, Clinton J
- Authors: Taylor, Geraldine C , Weyl, Olaf L F , Hill, Jaclyn M , Peel, Richard A , Hay, Clinton J
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68961 , vital:29343 , https://doi.org/10.1111/fwb.13032
- Description: The Upper Zambezi, Kavango and Kwando are large floodplain rivers with substantial biodiversity, providing water and ecosystem services to a large tract of southern Africa. These rivers differ in hydrological regime. The Upper Zambezi and Kavango rivers are in flood for 4 months (March, April, May, June) while, in the Kwando River, floods are later and last for 1–2 months in July and August. The Upper Zambezi River has the largest annual flood pulse, followed by the Kavango River, while the Kwando River experiences small and unreliable floods. During years of exceptional flooding of the Upper Zambezi and Kavango rivers, the rivers are interconnected at peak flows and therefore share a common ichthyofauna. This provided a natural experiment to investigate the responses of fish communities comprised of the same species to differing flood regimes by comparing the fish assemblages and food‐web structures between rivers.
- Full Text: false
- Date Issued: 2017
- Authors: Taylor, Geraldine C , Weyl, Olaf L F , Hill, Jaclyn M , Peel, Richard A , Hay, Clinton J
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68961 , vital:29343 , https://doi.org/10.1111/fwb.13032
- Description: The Upper Zambezi, Kavango and Kwando are large floodplain rivers with substantial biodiversity, providing water and ecosystem services to a large tract of southern Africa. These rivers differ in hydrological regime. The Upper Zambezi and Kavango rivers are in flood for 4 months (March, April, May, June) while, in the Kwando River, floods are later and last for 1–2 months in July and August. The Upper Zambezi River has the largest annual flood pulse, followed by the Kavango River, while the Kwando River experiences small and unreliable floods. During years of exceptional flooding of the Upper Zambezi and Kavango rivers, the rivers are interconnected at peak flows and therefore share a common ichthyofauna. This provided a natural experiment to investigate the responses of fish communities comprised of the same species to differing flood regimes by comparing the fish assemblages and food‐web structures between rivers.
- Full Text: false
- Date Issued: 2017
Small steps to equal dignity: the work of the South African equality courts
- Authors: Krüger, Rósaan
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68920 , vital:29339 , http://www.equalrightstrust.org/ertdocumentbank/ERR7_kruger.pdf
- Description: Publisher version , Introduction: “The South African Constitution is primarily and emphatically an egalitarian constitution. The supreme laws of comparable constitutional states may underscore other principles and rights. But in the light of our own particular history, and our vision for the future, a constitution was written with equality at its centre. Equality is our Constitution’s focus and organising principle.” Given the foundational role of equality in the South African constitutional framework, the drafters of the South African Constitution (the Constitution) directed the South African Parliament (Parliament) to enact legislation to “prevent or prohibit unfair discrimination” between individuals within three years of the enactment of the Constitution.3 Under great pressure, Parliament finalised and passed the Promotion of Equality and Prevention of Unfair Discrimination Act (the Equality Act) within two days of the constitutional deadline.4 The Equality Act, as the title indicates, addresses the promotion of equality on the one hand, and provides for reactive measures where the equality right is breached, on the other. The reactive provisions include the prohibition of unfair discrimination and related infringements of the equality right. The Equality Act expressly provides for the enforcement of its provisions in specifically created equality courts. The majority of the reactive provisions of the Equality Act have been operational since 16 June 2003. More than a decade after the enactment of the legislation, the promotional aspects of the Equality Act are yet to come into operation. This article focuses on the reactive provisions of the Equality Act by providing a snapshot of the work of selected South African equality courts for the period from June 2003 to December 2007 insofar as complaints of racism are concerned. In order to contextualise the application of the Equality Act, the article provides a brief overview of the reactive provisions of the Equality Act and the mechanisms for its enforcement.
- Full Text: false
- Date Issued: 2011
- Authors: Krüger, Rósaan
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68920 , vital:29339 , http://www.equalrightstrust.org/ertdocumentbank/ERR7_kruger.pdf
- Description: Publisher version , Introduction: “The South African Constitution is primarily and emphatically an egalitarian constitution. The supreme laws of comparable constitutional states may underscore other principles and rights. But in the light of our own particular history, and our vision for the future, a constitution was written with equality at its centre. Equality is our Constitution’s focus and organising principle.” Given the foundational role of equality in the South African constitutional framework, the drafters of the South African Constitution (the Constitution) directed the South African Parliament (Parliament) to enact legislation to “prevent or prohibit unfair discrimination” between individuals within three years of the enactment of the Constitution.3 Under great pressure, Parliament finalised and passed the Promotion of Equality and Prevention of Unfair Discrimination Act (the Equality Act) within two days of the constitutional deadline.4 The Equality Act, as the title indicates, addresses the promotion of equality on the one hand, and provides for reactive measures where the equality right is breached, on the other. The reactive provisions include the prohibition of unfair discrimination and related infringements of the equality right. The Equality Act expressly provides for the enforcement of its provisions in specifically created equality courts. The majority of the reactive provisions of the Equality Act have been operational since 16 June 2003. More than a decade after the enactment of the legislation, the promotional aspects of the Equality Act are yet to come into operation. This article focuses on the reactive provisions of the Equality Act by providing a snapshot of the work of selected South African equality courts for the period from June 2003 to December 2007 insofar as complaints of racism are concerned. In order to contextualise the application of the Equality Act, the article provides a brief overview of the reactive provisions of the Equality Act and the mechanisms for its enforcement.
- Full Text: false
- Date Issued: 2011
Evaluating the IRI topside model for the South African region: An overview of the modelling techniques
- Sibanda, Patrick, McKinnell, Lee-Anne
- Authors: Sibanda, Patrick , McKinnell, Lee-Anne
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6810 , http://hdl.handle.net/10962/d1004303
- Description: The representation of the topside ionosphere (the region above the F2 peak) is critical because of the limited experimental data available. Over the years, a wide range of models have been developed in an effort to represent the behaviour and the shape of the electron density (Ne) profile of the topside ionosphere. Various studies have been centred around calculating the vertical scale height (VSH) and have included (a) obtaining VSH from Global Positioning System (GPS) derived total electron content (TEC), (b) calculating the VSH from ground-based ionosonde measurements, (c) using topside sounder vertical Ne profiles to obtain the VSH. One or a combination of the topside profilers (Chapman function, exponential function, sech-squared (Epstein) function, and/or parabolic function) is then used to reconstruct the topside Ne profile. The different approaches and the modelling techniques are discussed with a view to identifying the most adequate approach to apply to the South African region’s topside modelling efforts. The IRI-2001 topside model is evaluated based on how well it reproduces measured topside profiles over the South African region. This study is a first step in the process of developing a South African topside ionosphere model.
- Full Text:
- Date Issued: 2009
- Authors: Sibanda, Patrick , McKinnell, Lee-Anne
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6810 , http://hdl.handle.net/10962/d1004303
- Description: The representation of the topside ionosphere (the region above the F2 peak) is critical because of the limited experimental data available. Over the years, a wide range of models have been developed in an effort to represent the behaviour and the shape of the electron density (Ne) profile of the topside ionosphere. Various studies have been centred around calculating the vertical scale height (VSH) and have included (a) obtaining VSH from Global Positioning System (GPS) derived total electron content (TEC), (b) calculating the VSH from ground-based ionosonde measurements, (c) using topside sounder vertical Ne profiles to obtain the VSH. One or a combination of the topside profilers (Chapman function, exponential function, sech-squared (Epstein) function, and/or parabolic function) is then used to reconstruct the topside Ne profile. The different approaches and the modelling techniques are discussed with a view to identifying the most adequate approach to apply to the South African region’s topside modelling efforts. The IRI-2001 topside model is evaluated based on how well it reproduces measured topside profiles over the South African region. This study is a first step in the process of developing a South African topside ionosphere model.
- Full Text:
- Date Issued: 2009
Water, water everywhere: is Integrated Water Resource Management the right institutional prescription for South Africa's water management challenges?
- Madigele, Patricia K, Snowball, Jeanette D, Fraser, Gavin C G
- Authors: Madigele, Patricia K , Snowball, Jeanette D , Fraser, Gavin C G
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68555 , vital:29282 , http://2015.essa.org.za/fullpaper/essa_2849.pdf
- Description: Publisher version , Ostrom (2007) and Ostrom and Cox (2010) argue that natural resource management has been plagued by the “panacea problem": that one-size-fits-all solutions to allocation and management problems have been applied without due consideration of the specific context. The outcome has been the disappointing results of many development and management programs. Integrated Water Resource Management (IWRM) has been recognised as a potentially effective way of allocating water where there are multiple, sometimes competing, users (Saravanan et al. 2009). It has been used successfully in a number of other developing country contexts, including Mexico, Brazil, India and Thailand (Orne-Giliemann 2008; Meinzen-Dick 2007). The principles of IWRM were also adopted in South Africa under the National Water Act (1998). Water User Associations (WUA) are seen as one of the key institutions driving IWRM, since they are designed to allow stake-holders at local level a say in the allocation and management of this important public good (Aoki 2001). However, WUAs in South Africa have mostly not been a success and are currently being reviewed at national level. For the most part, emerging black farmers and rural communities still do not have equal access to water, or a meaningful role in decision-making, and there are significant security of supply and allocation issues with regard to municipal users as well. Using the AID (Institutional Analysis and Development) framework (Ostrom 2007), with particular reference to economic theory relating to incentives and transactions costs, this paper asks if IWRM is a panacea treatment that does not fit the diagnosis of South Africa's water management problems. A case study approach is used, focusing on one of the few established WUAs in the Sundays River Valley Municipality in a rural area of South Africa.
- Full Text:
- Date Issued: 2015
- Authors: Madigele, Patricia K , Snowball, Jeanette D , Fraser, Gavin C G
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68555 , vital:29282 , http://2015.essa.org.za/fullpaper/essa_2849.pdf
- Description: Publisher version , Ostrom (2007) and Ostrom and Cox (2010) argue that natural resource management has been plagued by the “panacea problem": that one-size-fits-all solutions to allocation and management problems have been applied without due consideration of the specific context. The outcome has been the disappointing results of many development and management programs. Integrated Water Resource Management (IWRM) has been recognised as a potentially effective way of allocating water where there are multiple, sometimes competing, users (Saravanan et al. 2009). It has been used successfully in a number of other developing country contexts, including Mexico, Brazil, India and Thailand (Orne-Giliemann 2008; Meinzen-Dick 2007). The principles of IWRM were also adopted in South Africa under the National Water Act (1998). Water User Associations (WUA) are seen as one of the key institutions driving IWRM, since they are designed to allow stake-holders at local level a say in the allocation and management of this important public good (Aoki 2001). However, WUAs in South Africa have mostly not been a success and are currently being reviewed at national level. For the most part, emerging black farmers and rural communities still do not have equal access to water, or a meaningful role in decision-making, and there are significant security of supply and allocation issues with regard to municipal users as well. Using the AID (Institutional Analysis and Development) framework (Ostrom 2007), with particular reference to economic theory relating to incentives and transactions costs, this paper asks if IWRM is a panacea treatment that does not fit the diagnosis of South Africa's water management problems. A case study approach is used, focusing on one of the few established WUAs in the Sundays River Valley Municipality in a rural area of South Africa.
- Full Text:
- Date Issued: 2015
Rewarding tax compliance: taxpayers’ attitudes and beliefs
- Bornman, Marina, Stack, Elizabeth M
- Authors: Bornman, Marina , Stack, Elizabeth M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61039 , vital:27931
- Description: In a society the tax climate is determined by the interaction between taxpayers and tax authorities. In a ‘service and client’ climate, taxpayers do not expect authorities to automatically suspect them of being tax evaders. Evidence suggests that recognising good tax behaviour with strategies of rewards has a positive effect on voluntary tax compliance. Principles derived from the cognitive evaluation theory predict that when feelings of competence are affirmed and this is accompanied by a sense of autonomy it can enhance the intrinsic motivation for an action. The present research surveyed the attitudes and beliefs of taxpayers involved in small business on being rewarded for tax compliance. Results were corroborated with the principles of the cognitive evaluation theory and it was found that that the principles of the theory are applicable to rewarding tax compliance behaviour.
- Full Text:
- Date Issued: 2015
- Authors: Bornman, Marina , Stack, Elizabeth M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61039 , vital:27931
- Description: In a society the tax climate is determined by the interaction between taxpayers and tax authorities. In a ‘service and client’ climate, taxpayers do not expect authorities to automatically suspect them of being tax evaders. Evidence suggests that recognising good tax behaviour with strategies of rewards has a positive effect on voluntary tax compliance. Principles derived from the cognitive evaluation theory predict that when feelings of competence are affirmed and this is accompanied by a sense of autonomy it can enhance the intrinsic motivation for an action. The present research surveyed the attitudes and beliefs of taxpayers involved in small business on being rewarded for tax compliance. Results were corroborated with the principles of the cognitive evaluation theory and it was found that that the principles of the theory are applicable to rewarding tax compliance behaviour.
- Full Text:
- Date Issued: 2015
Intraspecific mitochondrial gene variation can be as low as that of nuclear rRNA:
- Matumba, Tshifhiwa G, Oliver, Jody, Barker, Nigel P, McQuaid, Christopher D, Teske, Peter R
- Authors: Matumba, Tshifhiwa G , Oliver, Jody , Barker, Nigel P , McQuaid, Christopher D , Teske, Peter R
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160401 , vital:40442 , https://doi.org/10.12688/f1000research.23635.2
- Description: Mitochondrial DNA (mtDNA) has long been used to date historical demographic events. The idea that it is useful for molecular dating rests on the premise that its evolution is neutral. Even though this idea has long been challenged, the evidence against clock-like evolution of mtDNA is often ignored. Here, we present a particularly clear and simple example to illustrate the implications of violations of the assumption of selective neutrality.
- Full Text:
- Date Issued: 2020
- Authors: Matumba, Tshifhiwa G , Oliver, Jody , Barker, Nigel P , McQuaid, Christopher D , Teske, Peter R
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160401 , vital:40442 , https://doi.org/10.12688/f1000research.23635.2
- Description: Mitochondrial DNA (mtDNA) has long been used to date historical demographic events. The idea that it is useful for molecular dating rests on the premise that its evolution is neutral. Even though this idea has long been challenged, the evidence against clock-like evolution of mtDNA is often ignored. Here, we present a particularly clear and simple example to illustrate the implications of violations of the assumption of selective neutrality.
- Full Text:
- Date Issued: 2020