Incorporation of Ni(II)-dimethylglyoxime ion-imprinted polymer into electrospun polysulphone nanofibre for the determination of Ni(II) ions from aqueous samples
- Rammika, M, Darko, G, Torto, N
- Authors: Rammika, M , Darko, G , Torto, N
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6589 , http://hdl.handle.net/10962/d1004172
- Description: Ni(II)-dimethylglyoxime ion-imprinted polymer (Ni(II)-DMG IIP) was encapsulated in polysulphone and electrospun into nanofibres with diameters ranging from 406 to 854 nm. The structures of the Ni(II)-DMG encapsulated-IIP nanofibre, non-imprinted encapsulated-polymer nanofibre and polysulphone nanofibre mats were observed by scanning electron microscopy and evaluated by infrared spectroscopy. Electrospinning increased the specific surface area of the Ni(II)-DMG encapsulated-IIP nanofibre mats, as was evidenced by the low masses of the Ni(II)-DMG encapsulated-IIP nanofibre mats used. The accuracy of the method was validated by analysing a custom solution of certified reference material (SEP-3); the concentration of Ni(II) obtained was close to the certified one. The limit of detection was found to be 4.0x10-4 μg∙mℓ−1 while the limit of quantification was found to be 1.2x10-3 μg∙mℓ−1. The recovery of Ni(II) achieved using the Ni(II)-DMG imprinted nanofibre mats in water samples was found to range from 83 to 89%, while that of non-imprinted nanofibre mats was found to range from 59 to 65%, and that of polysulphone from 55 to 62%.
- Full Text:
- Date Issued: 2011
- Authors: Rammika, M , Darko, G , Torto, N
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6589 , http://hdl.handle.net/10962/d1004172
- Description: Ni(II)-dimethylglyoxime ion-imprinted polymer (Ni(II)-DMG IIP) was encapsulated in polysulphone and electrospun into nanofibres with diameters ranging from 406 to 854 nm. The structures of the Ni(II)-DMG encapsulated-IIP nanofibre, non-imprinted encapsulated-polymer nanofibre and polysulphone nanofibre mats were observed by scanning electron microscopy and evaluated by infrared spectroscopy. Electrospinning increased the specific surface area of the Ni(II)-DMG encapsulated-IIP nanofibre mats, as was evidenced by the low masses of the Ni(II)-DMG encapsulated-IIP nanofibre mats used. The accuracy of the method was validated by analysing a custom solution of certified reference material (SEP-3); the concentration of Ni(II) obtained was close to the certified one. The limit of detection was found to be 4.0x10-4 μg∙mℓ−1 while the limit of quantification was found to be 1.2x10-3 μg∙mℓ−1. The recovery of Ni(II) achieved using the Ni(II)-DMG imprinted nanofibre mats in water samples was found to range from 83 to 89%, while that of non-imprinted nanofibre mats was found to range from 59 to 65%, and that of polysulphone from 55 to 62%.
- Full Text:
- Date Issued: 2011
Influences of food quality and quantity on the male reproductive organs of a seasonally breeding rodent, the pouched mouse (Saccostomus campestris), from a seasonal but unpredictable environment
- Tinney, Gregory M, Bernard, Ric T F, White, Rehema M
- Authors: Tinney, Gregory M , Bernard, Ric T F , White, Rehema M
- Date: 2001
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447258 , vital:74600 , https://doi.org/10.1080/15627020.2001.11657110
- Description: Reproduction in the pouched mouse (Saccostomus campestris) is inhibited in winter in the field and this seasonality is not controlled by photoperiod alone. The present study examines the hypothesis that reproduction in the pouched mouse is opportunistic (sensu Bronson 1989) and that the winter inhibition of reproduction is controlled by a reduction in either food quantity or quality. Food restriction (70 % of normal daily food intake) for six weeks, under short day conditions, was associated with a significant decrease in body fat index and mass of the accessory glands, testes and epididymides, while a high-fibre diet resulted in a significant reduction in fat index and masses of both the accessory glands and epididymides. A low-fibre/low-protein diet had no significant effect on either fat index or masses of the reproductive organs. Although the three experimental diets resulted in assimilation of significantly less energy than the controls, they did not inhibit spermatogenesis. We conclude that reproduction in the pouched mouse in the Eastern Cape Province is probably opportunistic and that the winter inhibition of reproduction may be controlled by a reduction in available energy which results from a combination of the lower ambient temperatures of winter and reduced food quantity and/or quality.
- Full Text:
- Date Issued: 2001
- Authors: Tinney, Gregory M , Bernard, Ric T F , White, Rehema M
- Date: 2001
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447258 , vital:74600 , https://doi.org/10.1080/15627020.2001.11657110
- Description: Reproduction in the pouched mouse (Saccostomus campestris) is inhibited in winter in the field and this seasonality is not controlled by photoperiod alone. The present study examines the hypothesis that reproduction in the pouched mouse is opportunistic (sensu Bronson 1989) and that the winter inhibition of reproduction is controlled by a reduction in either food quantity or quality. Food restriction (70 % of normal daily food intake) for six weeks, under short day conditions, was associated with a significant decrease in body fat index and mass of the accessory glands, testes and epididymides, while a high-fibre diet resulted in a significant reduction in fat index and masses of both the accessory glands and epididymides. A low-fibre/low-protein diet had no significant effect on either fat index or masses of the reproductive organs. Although the three experimental diets resulted in assimilation of significantly less energy than the controls, they did not inhibit spermatogenesis. We conclude that reproduction in the pouched mouse in the Eastern Cape Province is probably opportunistic and that the winter inhibition of reproduction may be controlled by a reduction in available energy which results from a combination of the lower ambient temperatures of winter and reduced food quantity and/or quality.
- Full Text:
- Date Issued: 2001
Information extraction model from Ge’ez texts
- Gebeyehu, Seffi, Wolde, Worke, Shibeshi, Zelalem S
- Authors: Gebeyehu, Seffi , Wolde, Worke , Shibeshi, Zelalem S
- Date: 2023
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429176 , vital:72565 , 10.11591/ijeecs.v30.i2.pp787-795
- Description: Nowadays, voluminous and unstructured textual data is found on the Internet that could provide varied valuable information for different institutions such as health care, business-related, training, religion, culture, and history, among others. A such alarming growth of unstructured data fosters the need for various methods and techniques to extract valuable information from unstructured data. However, exploring helpful information to satisfy the needs of the stakeholders becomes a problem due to information overload via the internet. This paper, therefore, presents an effective model for extracting named entities from Ge'ez text using deep learning algorithms. A data set with a total of 5,270 sentences were used for training and testing purposes. Two experimental setups, i.e., long short-term memory (LSTM) and bidirectional long short-term memory (Bi-LSTM) were used to make an empirical evaluation with training and a testing split ratio of 80% to 20%, respectively. Experimental results showed that the proposed model could be a practical solution for building information extraction (IE) systems using Bi-LSTM, reaching a training, validation, and testing accuracy as high as 98.59%, 97.96%, and 96.21%, respectively. The performance evaluation results reflect a promising performance of the model compared with resource-rich languages such as English.
- Full Text:
- Date Issued: 2023
- Authors: Gebeyehu, Seffi , Wolde, Worke , Shibeshi, Zelalem S
- Date: 2023
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429176 , vital:72565 , 10.11591/ijeecs.v30.i2.pp787-795
- Description: Nowadays, voluminous and unstructured textual data is found on the Internet that could provide varied valuable information for different institutions such as health care, business-related, training, religion, culture, and history, among others. A such alarming growth of unstructured data fosters the need for various methods and techniques to extract valuable information from unstructured data. However, exploring helpful information to satisfy the needs of the stakeholders becomes a problem due to information overload via the internet. This paper, therefore, presents an effective model for extracting named entities from Ge'ez text using deep learning algorithms. A data set with a total of 5,270 sentences were used for training and testing purposes. Two experimental setups, i.e., long short-term memory (LSTM) and bidirectional long short-term memory (Bi-LSTM) were used to make an empirical evaluation with training and a testing split ratio of 80% to 20%, respectively. Experimental results showed that the proposed model could be a practical solution for building information extraction (IE) systems using Bi-LSTM, reaching a training, validation, and testing accuracy as high as 98.59%, 97.96%, and 96.21%, respectively. The performance evaluation results reflect a promising performance of the model compared with resource-rich languages such as English.
- Full Text:
- Date Issued: 2023
Innovation through education: rediscovering the lost generation
- Authors: Pieterse, Koot
- Subjects: Business incubators , Entrepreneurship , f-sa
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/20889 , vital:29411
- Description: Innovation implies the generation as well as the practical implementation of new ideas. These ideas could appear as new product opportunities, new markets or new management systems and business schools are ideally situated to promote their exploitation and implementation. This study emphasises the need for business schools to elevate innovation to one of the core values in their mission. The need for innovation in the local business environment is explored along with reasons why these opportunities have not always been pursued with the required vigour. The results of a literature study are represented, that demonstrate what initiatives on the incorporation of innovation into their activities have been taken by a selection of business schools around the world and the study is concluded by exploring similar opportunities open to the Business School of the Nelson Mandela Metropolitan University.
- Full Text:
- Authors: Pieterse, Koot
- Subjects: Business incubators , Entrepreneurship , f-sa
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/20889 , vital:29411
- Description: Innovation implies the generation as well as the practical implementation of new ideas. These ideas could appear as new product opportunities, new markets or new management systems and business schools are ideally situated to promote their exploitation and implementation. This study emphasises the need for business schools to elevate innovation to one of the core values in their mission. The need for innovation in the local business environment is explored along with reasons why these opportunities have not always been pursued with the required vigour. The results of a literature study are represented, that demonstrate what initiatives on the incorporation of innovation into their activities have been taken by a selection of business schools around the world and the study is concluded by exploring similar opportunities open to the Business School of the Nelson Mandela Metropolitan University.
- Full Text:
Insect herbivores on the exotic weeds Solanum elaeagnifolium Cavanilles and S. sisymbriifolium Lamarck (Solanaceae) in South Africa
- Hill, Martin P, Hulley, Patrick E, Olckers, T
- Authors: Hill, Martin P , Hulley, Patrick E , Olckers, T
- Date: 1993
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451454 , vital:75050 , https://hdl.handle.net/10520/AJA10213589_58
- Description: In South Africa, the weeds Solanum elaeagnifolium Cavanilles and S. sisymbriifolium Lamarck (Solanaceae) sustain little observable damage from herbivorous insects. Relatively few insect species occur on these plants and at low individual densities. Since native insects are not important in the natural control of S. elaeagnifolium and S. sisymbriifolium, additional agents should be imported for the biological control of these weeds. The absence of important local herbivores means that the possibility of interaction between these and potential biological control agents need not be a consideration in choosing the agents. The nature and numbers of the insect herbivores of S. elaeagnifolium and S. sisymbriifolium are compared with those on another solanaceous weed, S. mauritianum Scopoli, and on native Solanum species. These insect species are discussed relative to plant defence mechanisms.
- Full Text:
- Date Issued: 1993
- Authors: Hill, Martin P , Hulley, Patrick E , Olckers, T
- Date: 1993
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451454 , vital:75050 , https://hdl.handle.net/10520/AJA10213589_58
- Description: In South Africa, the weeds Solanum elaeagnifolium Cavanilles and S. sisymbriifolium Lamarck (Solanaceae) sustain little observable damage from herbivorous insects. Relatively few insect species occur on these plants and at low individual densities. Since native insects are not important in the natural control of S. elaeagnifolium and S. sisymbriifolium, additional agents should be imported for the biological control of these weeds. The absence of important local herbivores means that the possibility of interaction between these and potential biological control agents need not be a consideration in choosing the agents. The nature and numbers of the insect herbivores of S. elaeagnifolium and S. sisymbriifolium are compared with those on another solanaceous weed, S. mauritianum Scopoli, and on native Solanum species. These insect species are discussed relative to plant defence mechanisms.
- Full Text:
- Date Issued: 1993
Insights from experimental economics on local cooperation in a small-scale fishery management system:
- Aswani, Shankar, Gurney, Georgina G, Mulville, Sara, Matera, Jaime, Gurven, Michael
- Authors: Aswani, Shankar , Gurney, Georgina G , Mulville, Sara , Matera, Jaime , Gurven, Michael
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145437 , vital:38438 , DOI: 10.1016/j.gloenvcha.2013.08.003
- Description: Cooperation is central to collective management of small-scale fisheries management, including marine protected areas. Thus an understanding of the factors influencing stakeholders’ propensity to cooperate to achieve shared benefits is essential to accomplishing successful collective fisheries management. In this paper we study stakeholders’ cooperative behavioral disposition and elucidate the role of various socio-economic factors in influencing it in the Roviana Lagoon, Western Solomon Islands. We employed a Public Goods Game from experimental economics tailored to mimic the problem of common pool fisheries management to elucidate peoples’ cooperative behavior. Using Ostrom's framework for analyzing social-ecological systems to guide our analysis, we examined how individual-scale variables (e.g., age, education, family size, ethnicity, occupational status, personal norms), in the context of village-scale variables (e.g., village, governance institutions, group coercive action), influence cooperative behavior, as indexed by game contribution. Ostrom's framework provides an effective window for conceptually peeling back the various socio-economic and governance layers which influence cooperation within these communities.
- Full Text:
- Date Issued: 2013
- Authors: Aswani, Shankar , Gurney, Georgina G , Mulville, Sara , Matera, Jaime , Gurven, Michael
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145437 , vital:38438 , DOI: 10.1016/j.gloenvcha.2013.08.003
- Description: Cooperation is central to collective management of small-scale fisheries management, including marine protected areas. Thus an understanding of the factors influencing stakeholders’ propensity to cooperate to achieve shared benefits is essential to accomplishing successful collective fisheries management. In this paper we study stakeholders’ cooperative behavioral disposition and elucidate the role of various socio-economic factors in influencing it in the Roviana Lagoon, Western Solomon Islands. We employed a Public Goods Game from experimental economics tailored to mimic the problem of common pool fisheries management to elucidate peoples’ cooperative behavior. Using Ostrom's framework for analyzing social-ecological systems to guide our analysis, we examined how individual-scale variables (e.g., age, education, family size, ethnicity, occupational status, personal norms), in the context of village-scale variables (e.g., village, governance institutions, group coercive action), influence cooperative behavior, as indexed by game contribution. Ostrom's framework provides an effective window for conceptually peeling back the various socio-economic and governance layers which influence cooperation within these communities.
- Full Text:
- Date Issued: 2013
Interpreting the Text of the Hebrew Bible: THB 211
- Authors: Adolph, E , Oosthuizen, R
- Date: 2011-06
- Language: English
- Type: Examination paper
- Identifier: vital:18160 , http://hdl.handle.net/10353/d1011089
- Description: Interpreting the Text of the Hebrew Bible: THB 211, degree examination June/July 2011.
- Full Text: false
- Date Issued: 2011-06
- Authors: Adolph, E , Oosthuizen, R
- Date: 2011-06
- Language: English
- Type: Examination paper
- Identifier: vital:18160 , http://hdl.handle.net/10353/d1011089
- Description: Interpreting the Text of the Hebrew Bible: THB 211, degree examination June/July 2011.
- Full Text: false
- Date Issued: 2011-06
Intra- and interspecific brood recognition in pure and mixed-species honeybee colonies, Apis cerana and A. mellifera
- Tan, K, Yang, M-X, Radloff, Sarah E, Yu, Y, Pirk, Christian W W, Hepburn, H Randall
- Authors: Tan, K , Yang, M-X , Radloff, Sarah E , Yu, Y , Pirk, Christian W W , Hepburn, H Randall
- Date: 2009
- Subjects: Apis mellifera Apis cerana
- Language: English
- Type: text , Article
- Identifier: vital:6837 , http://hdl.handle.net/10962/d1010962 , http://dx.doi.org/10.1051/apido/2009003
- Description: We studied the effects of mixed honeybee colonies of Apis mellifera and Apis cerana on the intraspecific and interspecific recognition of female brood stages in the honeybees A. cerana and A. mellifera by transferring brood combs between queenright colonies. In the intraspecific tests, significantly more larvae were removed in A. cerana than in A. mellifera, whilst significantly fewer eggs and pupae were removed in A. cerana than in A. mellifera. In the interspecific tests, A. cerana colonies removed significantly more larvae and pupae of A. mellifera than the same brood stages of A. cerana were removed by A. mellifera. We show there are highly significant differences in both intraspecific and interspecific brood recognition between A. cerana and A. mellifera and that brood recognition operates with decreasing intensity with increasing developmental age within species. This suggests that worker policing in egg removal is a first line of defense against heterospecific social parasites.
- Full Text: false
- Date Issued: 2009
- Authors: Tan, K , Yang, M-X , Radloff, Sarah E , Yu, Y , Pirk, Christian W W , Hepburn, H Randall
- Date: 2009
- Subjects: Apis mellifera Apis cerana
- Language: English
- Type: text , Article
- Identifier: vital:6837 , http://hdl.handle.net/10962/d1010962 , http://dx.doi.org/10.1051/apido/2009003
- Description: We studied the effects of mixed honeybee colonies of Apis mellifera and Apis cerana on the intraspecific and interspecific recognition of female brood stages in the honeybees A. cerana and A. mellifera by transferring brood combs between queenright colonies. In the intraspecific tests, significantly more larvae were removed in A. cerana than in A. mellifera, whilst significantly fewer eggs and pupae were removed in A. cerana than in A. mellifera. In the interspecific tests, A. cerana colonies removed significantly more larvae and pupae of A. mellifera than the same brood stages of A. cerana were removed by A. mellifera. We show there are highly significant differences in both intraspecific and interspecific brood recognition between A. cerana and A. mellifera and that brood recognition operates with decreasing intensity with increasing developmental age within species. This suggests that worker policing in egg removal is a first line of defense against heterospecific social parasites.
- Full Text: false
- Date Issued: 2009
Introduction to Agricultural Economics: AGE 111
- Authors: Mushunje, A , Obi, A
- Date: 2011-08
- Subjects: Agriculture -- Economic aspects
- Language: English
- Type: Examination paper
- Identifier: vital:17648 , http://hdl.handle.net/10353/d1010027
- Description: Introduction to Agricultural Economics: AGE 111, examination August 2011.
- Full Text: false
- Date Issued: 2011-08
- Authors: Mushunje, A , Obi, A
- Date: 2011-08
- Subjects: Agriculture -- Economic aspects
- Language: English
- Type: Examination paper
- Identifier: vital:17648 , http://hdl.handle.net/10353/d1010027
- Description: Introduction to Agricultural Economics: AGE 111, examination August 2011.
- Full Text: false
- Date Issued: 2011-08
Introduction to Agricultural Economics: AGE 111
- Authors: Mushunje, A , Obi, A
- Date: 2011-06
- Language: English
- Type: Examination paper
- Identifier: vital:17665 , http://hdl.handle.net/10353/d1010055
- Description: Introduction to Agricultural Economics: AGE 111, examination June 2011.
- Full Text: false
- Date Issued: 2011-06
- Authors: Mushunje, A , Obi, A
- Date: 2011-06
- Language: English
- Type: Examination paper
- Identifier: vital:17665 , http://hdl.handle.net/10353/d1010055
- Description: Introduction to Agricultural Economics: AGE 111, examination June 2011.
- Full Text: false
- Date Issued: 2011-06
Introduction to Computers and Computing: CLT 111 & 111F
- Authors: Ntlabathi, S , Xazela, W
- Date: 2011-06
- Language: English
- Type: Examination paper
- Identifier: vital:17892 , http://hdl.handle.net/10353/d1011060
- Description: Introduction to Computers & Computing: CLT 111 and 111F, degree examination June 2011.
- Full Text: false
- Date Issued: 2011-06
- Authors: Ntlabathi, S , Xazela, W
- Date: 2011-06
- Language: English
- Type: Examination paper
- Identifier: vital:17892 , http://hdl.handle.net/10353/d1011060
- Description: Introduction to Computers & Computing: CLT 111 and 111F, degree examination June 2011.
- Full Text: false
- Date Issued: 2011-06
Introduction: the need to understand the ecological sustainability of non-timber forest products harvesting systems
- Shackleton, Charlie M, Ticktin, Tamara, Pandey, Ashok K
- Authors: Shackleton, Charlie M , Ticktin, Tamara , Pandey, Ashok K
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433683 , vital:72994 , ISBN 9781317916130 , https://www.taylorfrancis.com/chapters/edit/10.4324/9781315851587-2/introduction-charlie-shackleton-tamara-ticktin-ashok-pandey
- Description: The importance of non-timber forest products (NTFPs) in rural livelihoods in developing countries has become widely acknowledged over the last decade or so within the research and, increasingly, policy arenas, on the basis of numerous studies from around the world. Indeed, there has been a tenfold increase in the annual number of research papers published over the last 20 years (Figure 1.1). Most of these studies are from developing countries, but they do include developed countries (e.g. Kim et al. 2012, Poe et al. 2013, Sténs and Sandström 2013). Additionally, most are from rural areas, albeit with a smattering from urban settings (e.g. Kilchling et al. 2009, Poe et al. 2013, Kaoma and Shackleton 2014), although with increasing urbanization this distinction is blurred with significant markets for rural NTFPs imported into towns and cities (Lewis 2008, Padoch et al. 2008, McMullin et al. 2012). Two pertinent findings of many of these studies is that NTFPs generally contribute in many different ways to local livelihoods (see Chapter 2) and that when translated into income terms many households earn a significant proportion of their income (cash and/or non-cash) from NTFPs (Shackleton et al. 2007, Angelsen et al. 2014). In other words, they are not simply minor products of little value, but rather they are vital components of livelihoods, and in some instances, of local and regional economies. This requires that they, and the land on which they are found, are managed in a responsible manner to ensure that these livelihood benefits continue to accrue to rural, and often impoverished, people.
- Full Text:
- Date Issued: 2015
- Authors: Shackleton, Charlie M , Ticktin, Tamara , Pandey, Ashok K
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433683 , vital:72994 , ISBN 9781317916130 , https://www.taylorfrancis.com/chapters/edit/10.4324/9781315851587-2/introduction-charlie-shackleton-tamara-ticktin-ashok-pandey
- Description: The importance of non-timber forest products (NTFPs) in rural livelihoods in developing countries has become widely acknowledged over the last decade or so within the research and, increasingly, policy arenas, on the basis of numerous studies from around the world. Indeed, there has been a tenfold increase in the annual number of research papers published over the last 20 years (Figure 1.1). Most of these studies are from developing countries, but they do include developed countries (e.g. Kim et al. 2012, Poe et al. 2013, Sténs and Sandström 2013). Additionally, most are from rural areas, albeit with a smattering from urban settings (e.g. Kilchling et al. 2009, Poe et al. 2013, Kaoma and Shackleton 2014), although with increasing urbanization this distinction is blurred with significant markets for rural NTFPs imported into towns and cities (Lewis 2008, Padoch et al. 2008, McMullin et al. 2012). Two pertinent findings of many of these studies is that NTFPs generally contribute in many different ways to local livelihoods (see Chapter 2) and that when translated into income terms many households earn a significant proportion of their income (cash and/or non-cash) from NTFPs (Shackleton et al. 2007, Angelsen et al. 2014). In other words, they are not simply minor products of little value, but rather they are vital components of livelihoods, and in some instances, of local and regional economies. This requires that they, and the land on which they are found, are managed in a responsible manner to ensure that these livelihood benefits continue to accrue to rural, and often impoverished, people.
- Full Text:
- Date Issued: 2015
Invasion of a headwater stream by non-native fishes in the Swartkops River system, South Africa
- Ellender, Bruce R, Weyl, Olaf L F, Swartz, Ernst R
- Authors: Ellender, Bruce R , Weyl, Olaf L F , Swartz, Ernst R
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446866 , vital:74566 , https://doi.org/10.1080/15627020.2011.11407477
- Description: In South Africa, fishes in headwater streams are increasingly being threatened by non-native fish invasions. These invasions originate primarily from source populations in mainstream rivers and impoundments. In the Blindekloof stream, a Swartkops River headwater tributary, the non-native Micropterus salmoides was eradicated from the stream by conservation authorities in 1989. As a result of this eradication subsequent occurrences of non-native fishes are most likely a result of upstream invasions from the mainstream Swartkops River. The Blindekloof stream therefore provided a unique opportunity to investigate whether M. salmoides would reinvade after its removal in 1989 and if the more recently introduced Clarias gariepinus and Tilapia sparrmanii would invade the Blindekloof stream. During snorkel and electrofishing surveys four non-native species were recorded (M. salmoides, M. dolomieu, T. sparrmanii, C. gariepinus ).
- Full Text:
- Date Issued: 2011
- Authors: Ellender, Bruce R , Weyl, Olaf L F , Swartz, Ernst R
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446866 , vital:74566 , https://doi.org/10.1080/15627020.2011.11407477
- Description: In South Africa, fishes in headwater streams are increasingly being threatened by non-native fish invasions. These invasions originate primarily from source populations in mainstream rivers and impoundments. In the Blindekloof stream, a Swartkops River headwater tributary, the non-native Micropterus salmoides was eradicated from the stream by conservation authorities in 1989. As a result of this eradication subsequent occurrences of non-native fishes are most likely a result of upstream invasions from the mainstream Swartkops River. The Blindekloof stream therefore provided a unique opportunity to investigate whether M. salmoides would reinvade after its removal in 1989 and if the more recently introduced Clarias gariepinus and Tilapia sparrmanii would invade the Blindekloof stream. During snorkel and electrofishing surveys four non-native species were recorded (M. salmoides, M. dolomieu, T. sparrmanii, C. gariepinus ).
- Full Text:
- Date Issued: 2011
Irreplaceable acting
- Authors: Wright, Laurence
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/453995 , vital:75303 , https://hdl.handle.net/10520/EJC142419
- Description: What do I mean by irreplaceable acting? In one way all acting is irreplaceable. Very obviously, without acting there is no play, just a text - perhaps not even that, if one considers improvised pieces or physical theatre scenarios. In a more important sense, all acting is replaceable, almost by definition. The same part is played by different actors on different stages in different ages. Acting is replaceable, because it is acting; it is not the real thing. But some performances, some moments on stage, seem to me best described as irreplaceable.
- Full Text:
- Date Issued: 2013
- Authors: Wright, Laurence
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/453995 , vital:75303 , https://hdl.handle.net/10520/EJC142419
- Description: What do I mean by irreplaceable acting? In one way all acting is irreplaceable. Very obviously, without acting there is no play, just a text - perhaps not even that, if one considers improvised pieces or physical theatre scenarios. In a more important sense, all acting is replaceable, almost by definition. The same part is played by different actors on different stages in different ages. Acting is replaceable, because it is acting; it is not the real thing. But some performances, some moments on stage, seem to me best described as irreplaceable.
- Full Text:
- Date Issued: 2013
Izwilethu
- Council of Unions of South Africa (CUSA)
- Authors: Council of Unions of South Africa (CUSA)
- Date: 1986-10
- Language: English
- Type: newspaper , text
- Identifier: http://hdl.handle.net/10962/60097 , vital:27733
- Description: Izwilethu newspaper, vol. 4, no. 8. Oct. 1986 Conference Issue.
- Full Text:
- Date Issued: 1986-10
- Authors: Council of Unions of South Africa (CUSA)
- Date: 1986-10
- Language: English
- Type: newspaper , text
- Identifier: http://hdl.handle.net/10962/60097 , vital:27733
- Description: Izwilethu newspaper, vol. 4, no. 8. Oct. 1986 Conference Issue.
- Full Text:
- Date Issued: 1986-10
Kinetic analysis and general features of thermoluminescence of B2O3-Li2O-ZnF2 glass
- Thomas, Sunil, Chithambo, Makaiko L
- Authors: Thomas, Sunil , Chithambo, Makaiko L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/116154 , vital:34324 , https://doi.org/10.1016/j.radmeas.2017.03.038
- Description: The intention of this study is to explore the thermoluminescence of beta irradiated B2O3-Li2O-ZnF2 glass. The glow-curve corresponding to 200 Gy shows three peaks; two weak-intensity peaks at 60 and 243 °C and a more prominent one at 118 °C, when measured at 1 °C/s. The dose response of the main peak at 118 °C was found to be sublinear in the range 200–1000 Gy. Regarding the kinetic analysis of the main peak, the activation energy of the corresponding electron trap was evaluated as 0.96 eV and the frequency factor as ∼1011 s−1. It is proposed that the thermoluminescence in B2O3-Li2O-ZnF2 glass is due to recombination of electrons, thermally released from Zn+ ionic defect sites, with the holes at boron-oxygen hole centres.
- Full Text: false
- Date Issued: 2017
- Authors: Thomas, Sunil , Chithambo, Makaiko L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/116154 , vital:34324 , https://doi.org/10.1016/j.radmeas.2017.03.038
- Description: The intention of this study is to explore the thermoluminescence of beta irradiated B2O3-Li2O-ZnF2 glass. The glow-curve corresponding to 200 Gy shows three peaks; two weak-intensity peaks at 60 and 243 °C and a more prominent one at 118 °C, when measured at 1 °C/s. The dose response of the main peak at 118 °C was found to be sublinear in the range 200–1000 Gy. Regarding the kinetic analysis of the main peak, the activation energy of the corresponding electron trap was evaluated as 0.96 eV and the frequency factor as ∼1011 s−1. It is proposed that the thermoluminescence in B2O3-Li2O-ZnF2 glass is due to recombination of electrons, thermally released from Zn+ ionic defect sites, with the holes at boron-oxygen hole centres.
- Full Text: false
- Date Issued: 2017
Kowieria alveoformis gen. nov. sp. nov., a new heterosporous lycophyte from the Latest Devonian of Southern Africa
- Gess, Robert W, Prestianni, Cyrille
- Authors: Gess, Robert W , Prestianni, Cyrille
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/73894 , vital:30239 , https://doi.org/10.1016/j.revpalbo.2017.10.002
- Description: A new lycopsid, Kowieria alveoformis gen. et sp. nov., is described from the FamennianWitpoort Formation, Grahamstown, South Africa. It possesses spirally arranged elongated falcate vegetative leaves. Terminal bisporangiate strobili are present and show loosely grouped micro- and megasporophylls. Sporophylls are similar in shape to the vegetative leaves though somewhat wider with a marked expansion to house the sporangium. One sporangium is attached directly to the adaxial surface of the lamina. Each megasporangium contains up to four heavily ornamented hologulate megaspores of the Lagenicula type. The combination of both basal and derived characters within this plant places it at an interesting position at the base of the phylogenetic tree of rhizomorphic lycopsids.
- Full Text:
- Date Issued: 2018
- Authors: Gess, Robert W , Prestianni, Cyrille
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/73894 , vital:30239 , https://doi.org/10.1016/j.revpalbo.2017.10.002
- Description: A new lycopsid, Kowieria alveoformis gen. et sp. nov., is described from the FamennianWitpoort Formation, Grahamstown, South Africa. It possesses spirally arranged elongated falcate vegetative leaves. Terminal bisporangiate strobili are present and show loosely grouped micro- and megasporophylls. Sporophylls are similar in shape to the vegetative leaves though somewhat wider with a marked expansion to house the sporangium. One sporangium is attached directly to the adaxial surface of the lamina. Each megasporangium contains up to four heavily ornamented hologulate megaspores of the Lagenicula type. The combination of both basal and derived characters within this plant places it at an interesting position at the base of the phylogenetic tree of rhizomorphic lycopsids.
- Full Text:
- Date Issued: 2018
Language policy and planning: general constraints and pressures
- Authors: Wright, Laurence
- Date: 2007
- Language: English
- Type: text , article
- Identifier: vital:7043 , http://hdl.handle.net/10962/d1007385
- Description: preprint , The general idea of language policy and planning is easily expressed. Christopher Brumfit, for one, defines language planning as “The attempt to control the use, status, and structure of a language through a language policy developed by a government or other authority” (see the Oxford Companion to the English Language). The Random House Dictionary of the English Language concurs, but adds some detail: language planning is “the development of policies or programmes designed to direct or change language use, as through the establishment of an official language, the standardization or modernization of a language, or the development or alteration of a writing system”. Such definitions could easily be multiplied, and they differ only slightly in nuance and depth.Language Policy is the formal, often legally entrenched, expression of language planning.
- Full Text:
- Date Issued: 2007
- Authors: Wright, Laurence
- Date: 2007
- Language: English
- Type: text , article
- Identifier: vital:7043 , http://hdl.handle.net/10962/d1007385
- Description: preprint , The general idea of language policy and planning is easily expressed. Christopher Brumfit, for one, defines language planning as “The attempt to control the use, status, and structure of a language through a language policy developed by a government or other authority” (see the Oxford Companion to the English Language). The Random House Dictionary of the English Language concurs, but adds some detail: language planning is “the development of policies or programmes designed to direct or change language use, as through the establishment of an official language, the standardization or modernization of a language, or the development or alteration of a writing system”. Such definitions could easily be multiplied, and they differ only slightly in nuance and depth.Language Policy is the formal, often legally entrenched, expression of language planning.
- Full Text:
- Date Issued: 2007
Learning about sustainability through experiencing complex, adverse conditions typical of the South : reflections from the African Catchment Games played in Finland 2008
- Fraenkel, Linda A, Fox, Roddy C
- Authors: Fraenkel, Linda A , Fox, Roddy C
- Date: 2009
- Language: English
- Type: Conference paper
- Identifier: vital:6666 , http://hdl.handle.net/10962/d1006678
- Description: The African Catchment Game is an innovative role playing game which was played twice in Finland in 2008 as part of the CIMO funded collaboration between Finland Futures Research Centre and Rhodes University. It simulates a "real imaginary country" and enables participants to explore and experience how southern countries may or may not develop scenarios of sustainable resource extraction and consumption. New processes modelling climatic variability, water management and consumption were introduced for these two game runs. This imaginary country has roles for an urban/industrial sector, the informal sector, trading intermediaries, overseas trade, a government comprised of a president and two ministers, peasant and commercial farmers. Chapman's original game, Green Revolution Game/Exaction, is based on systems and complexity theories from the 1970s and 1980s. Our modifications to Chapman’s game are underpinned by theories of Complex Adaptive Systems and educational approaches based on constructivist, active/experiential learning models. The paper presents an analysis of the two Finnish games from the perspectives of the participants and the game managers. Participants’ information came from pre and post game questionnaires and the focus group discussions that were part of the debriefing pro-cess. These two methods enabled us to examine the local and network processes which de-veloped during the games. Global scale processes of production, consumption, resource utilization, trading and water provision was collected by the game managers as part of their management processes throughout each game run. Our analysis shows that the par-ticipants’ understanding altered and deepened as a result of playing the game. The nature of the game, as a Complex Adaptive System, and the constructivist learning approach through which the game is experienced means that lessons of a more universal nature cannot be extrapolated.
- Full Text:
- Date Issued: 2009
- Authors: Fraenkel, Linda A , Fox, Roddy C
- Date: 2009
- Language: English
- Type: Conference paper
- Identifier: vital:6666 , http://hdl.handle.net/10962/d1006678
- Description: The African Catchment Game is an innovative role playing game which was played twice in Finland in 2008 as part of the CIMO funded collaboration between Finland Futures Research Centre and Rhodes University. It simulates a "real imaginary country" and enables participants to explore and experience how southern countries may or may not develop scenarios of sustainable resource extraction and consumption. New processes modelling climatic variability, water management and consumption were introduced for these two game runs. This imaginary country has roles for an urban/industrial sector, the informal sector, trading intermediaries, overseas trade, a government comprised of a president and two ministers, peasant and commercial farmers. Chapman's original game, Green Revolution Game/Exaction, is based on systems and complexity theories from the 1970s and 1980s. Our modifications to Chapman’s game are underpinned by theories of Complex Adaptive Systems and educational approaches based on constructivist, active/experiential learning models. The paper presents an analysis of the two Finnish games from the perspectives of the participants and the game managers. Participants’ information came from pre and post game questionnaires and the focus group discussions that were part of the debriefing pro-cess. These two methods enabled us to examine the local and network processes which de-veloped during the games. Global scale processes of production, consumption, resource utilization, trading and water provision was collected by the game managers as part of their management processes throughout each game run. Our analysis shows that the par-ticipants’ understanding altered and deepened as a result of playing the game. The nature of the game, as a Complex Adaptive System, and the constructivist learning approach through which the game is experienced means that lessons of a more universal nature cannot be extrapolated.
- Full Text:
- Date Issued: 2009
Lessons Learned In The Global Deployment Of An Open Source Security Solution
- Authors: Irwin, Barry V W
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428830 , vital:72539 , https://digifors.cs.up.ac.za/issa/2004/Proceedings/Research/023.pdf
- Description: This paper covers the lessons learned, and the challenges facing the deployment of an Open Source derivative firewall and Virtual Private Network (VPN) solution into the established commercially driven Tele-communications arena. The lessons learned and issues discussed are drawn from the author’s own experiences having worked for a global Wireless Application Service Provider over a three year period. Focus is placed on the issues surrounding the integration of the open source equipment with that of the established global Telecommunications players, where compliance to existing network standards was a re-quirement for connectivity. Major stumbling blocks to the acceptance and success of the open source product were the concerns expressed by the Telecommunications Operators relating to interoperability and troubleshooting facilities when interfaced to their existing commercially available equipment and existing rigid telecommunications networks. The processes resulting in the initial decision to utilise an open source solution in preference to commercial offerings are also explored. An open source solution was found to offer higher flexibility and functionali-ty and greater return on investment whilst maintaining a significantly re-duced cost in comparison to commercial solutions available.
- Full Text:
- Date Issued: 2004
- Authors: Irwin, Barry V W
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428830 , vital:72539 , https://digifors.cs.up.ac.za/issa/2004/Proceedings/Research/023.pdf
- Description: This paper covers the lessons learned, and the challenges facing the deployment of an Open Source derivative firewall and Virtual Private Network (VPN) solution into the established commercially driven Tele-communications arena. The lessons learned and issues discussed are drawn from the author’s own experiences having worked for a global Wireless Application Service Provider over a three year period. Focus is placed on the issues surrounding the integration of the open source equipment with that of the established global Telecommunications players, where compliance to existing network standards was a re-quirement for connectivity. Major stumbling blocks to the acceptance and success of the open source product were the concerns expressed by the Telecommunications Operators relating to interoperability and troubleshooting facilities when interfaced to their existing commercially available equipment and existing rigid telecommunications networks. The processes resulting in the initial decision to utilise an open source solution in preference to commercial offerings are also explored. An open source solution was found to offer higher flexibility and functionali-ty and greater return on investment whilst maintaining a significantly re-duced cost in comparison to commercial solutions available.
- Full Text:
- Date Issued: 2004