Media and cyber-democracy in Africa: an introduction
- Authors: Banda, Fackson
- Date: 2006
- Language: English
- Type: Conference paper
- Identifier: vital:6323 , http://hdl.handle.net/10962/d1008549
- Description: The paper provides a sketch of the discourse of media and ‘cyber-democracy’ in and out of Africa. Firstly, it discusses the characteristic features of new media technology. Secondly, it attempts a ‘theorising’ of cyber-democracy, within the context of general democratic theory. Thirdly, it sets out a vision of cyber-democracy for Africa. In delineating this vision, it highlights six features characteristic of the democratic potential of new media technology and gives examples of how Africa has appropriated them. Finally, it outlines a ‘new media’ research agenda for Africa.
- Full Text:
- Date Issued: 2006
- Authors: Banda, Fackson
- Date: 2006
- Language: English
- Type: Conference paper
- Identifier: vital:6323 , http://hdl.handle.net/10962/d1008549
- Description: The paper provides a sketch of the discourse of media and ‘cyber-democracy’ in and out of Africa. Firstly, it discusses the characteristic features of new media technology. Secondly, it attempts a ‘theorising’ of cyber-democracy, within the context of general democratic theory. Thirdly, it sets out a vision of cyber-democracy for Africa. In delineating this vision, it highlights six features characteristic of the democratic potential of new media technology and gives examples of how Africa has appropriated them. Finally, it outlines a ‘new media’ research agenda for Africa.
- Full Text:
- Date Issued: 2006
Media in the service of citizens
- Authors: Banda, Fackson
- Date: 2006
- Language: English
- Type: Conference paper
- Identifier: vital:6321 , http://hdl.handle.net/10962/d1008547
- Description: This lecture looks at the role of the media in promoting an enhanced citizenship, locating the debate within the discourse of development and freedom. It identifies threats to what can be characterised as a 'media-citizens compact', such as media over-commercialisation. It concludes that public-service media are cardinal to the enjoyment of citizenship rights and freedoms.
- Full Text:
- Date Issued: 2006
- Authors: Banda, Fackson
- Date: 2006
- Language: English
- Type: Conference paper
- Identifier: vital:6321 , http://hdl.handle.net/10962/d1008547
- Description: This lecture looks at the role of the media in promoting an enhanced citizenship, locating the debate within the discourse of development and freedom. It identifies threats to what can be characterised as a 'media-citizens compact', such as media over-commercialisation. It concludes that public-service media are cardinal to the enjoyment of citizenship rights and freedoms.
- Full Text:
- Date Issued: 2006
On the fast track to land degradation? A case study of the impact of the Fast Track Land Reform Programme in Kadoma District, Zimbabwe
- Fox, Roddy C, Rowntree, Kate M, Chigumira, Easther C
- Authors: Fox, Roddy C , Rowntree, Kate M , Chigumira, Easther C
- Date: 2006
- Language: English
- Type: Conference paper
- Identifier: vital:6663 , http://hdl.handle.net/10962/d1006668
- Description: The Fast Track Land Reform Programme is the defining instrument for Zimbabwe’s future development prospects. In the three year period from 2000 to 2002 300,000 families were resettled on 11 million hectares thus witnessing the end of the colonial division of land which had seen 15.5 million hectares still in European hands in 1980, the start of the post-colonial period. The process which displaced the commercial farm workers and farm owners was chaotic, violent and disorderly and so has been called jambanja. Subsequent legislation and government agricultural initiatives have attempted to impose, retroactively, technocratic order to the sweeping changes that have taken place. Our study shows that the dire macro-economic situation coupled with trends of HIV/AIDS prevalence means that developing sustainable land use practices is going to be a very difficult proposition. At the local scale, our case studies show that there have been multiple outcomes with low investment, very limited government support and resource extraction leading to land degradation and unsustainable farming practices. In some instances, however, individual households have benefitted in the short term from the process but this has only occurred where climatic and soil conditions have been particularly favourable.
- Full Text:
- Date Issued: 2006
- Authors: Fox, Roddy C , Rowntree, Kate M , Chigumira, Easther C
- Date: 2006
- Language: English
- Type: Conference paper
- Identifier: vital:6663 , http://hdl.handle.net/10962/d1006668
- Description: The Fast Track Land Reform Programme is the defining instrument for Zimbabwe’s future development prospects. In the three year period from 2000 to 2002 300,000 families were resettled on 11 million hectares thus witnessing the end of the colonial division of land which had seen 15.5 million hectares still in European hands in 1980, the start of the post-colonial period. The process which displaced the commercial farm workers and farm owners was chaotic, violent and disorderly and so has been called jambanja. Subsequent legislation and government agricultural initiatives have attempted to impose, retroactively, technocratic order to the sweeping changes that have taken place. Our study shows that the dire macro-economic situation coupled with trends of HIV/AIDS prevalence means that developing sustainable land use practices is going to be a very difficult proposition. At the local scale, our case studies show that there have been multiple outcomes with low investment, very limited government support and resource extraction leading to land degradation and unsustainable farming practices. In some instances, however, individual households have benefitted in the short term from the process but this has only occurred where climatic and soil conditions have been particularly favourable.
- Full Text:
- Date Issued: 2006
Sidelining developmental goals? Re-imaging Port Elizabeth for the 2010 Soccer World Cup
- Authors: Baines, Gary F
- Date: 2006
- Language: English
- Type: Conference paper
- Identifier: vital:6155 , http://hdl.handle.net/10962/d1007070
- Full Text:
- Date Issued: 2006
- Authors: Baines, Gary F
- Date: 2006
- Language: English
- Type: Conference paper
- Identifier: vital:6155 , http://hdl.handle.net/10962/d1007070
- Full Text:
- Date Issued: 2006
The deductibility of interest
- Gunn, Richard, Stack, Elizabeth M
- Authors: Gunn, Richard , Stack, Elizabeth M
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: Conference paper
- Identifier: vital:6063 , http://hdl.handle.net/10962/d1004603
- Description: The deduction of interest expenditure, for the purpose of calculating the South African taxable income on which normal tax is levied, must satisfy the requirements of the preamble to section 11 and section 11(a) of the Income Tax Act 58 of 1962, read with section 23(g), unless a particular section makes specific provision for its deduction. There appears to be a presumption that if interest expenditure is incurred in the production of income derived from carrying on a trade, it is deductible and we need look no further. This presumption may underlie the 2005 amendment of sub-section (2) of section 24J, which provides that interest is deductible provided it has been incurred “in the production of income” and “for the purposes of trade” (sections 11(a) and 23(g)). This paper discusses the deductibility of interest and, in particular, whether there are circumstances in which interest paid on a loan used to acquire a capital asset could be of a capital nature. The provisions of the Income Tax Act and court decisions relating to the deductibility of interest, as well as opinions expressed by authoritative writers on tax, are subjected to critical analysis. The paper first distinguishes the tests for determining whether an expense has been incurred “in the production of income” and whether the expense is “of a capital nature”. Specific court decisions relating to the deductibility of interest are then analysed. The research considers section 24J of the Act, to determine whether its provisions have settled the debate, and refers briefly to the provisions of section 11(bB), in the context of the research question. The conclusion reached in the research is that there are occasions where the courts appear to have confused the tests for determining whether interest expenditure was incurred “in the production of income” and whether it is “of a capital nature”, in certain instances have also failed to address the question of the capital or revenue nature of the interest expenditure under scrutiny, and that the matter does not appear to be settled that interest incurred on funds used to acquire a capital asset used to produce trade income is automatically deductible.
- Full Text:
- Date Issued: 2006
- Authors: Gunn, Richard , Stack, Elizabeth M
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: Conference paper
- Identifier: vital:6063 , http://hdl.handle.net/10962/d1004603
- Description: The deduction of interest expenditure, for the purpose of calculating the South African taxable income on which normal tax is levied, must satisfy the requirements of the preamble to section 11 and section 11(a) of the Income Tax Act 58 of 1962, read with section 23(g), unless a particular section makes specific provision for its deduction. There appears to be a presumption that if interest expenditure is incurred in the production of income derived from carrying on a trade, it is deductible and we need look no further. This presumption may underlie the 2005 amendment of sub-section (2) of section 24J, which provides that interest is deductible provided it has been incurred “in the production of income” and “for the purposes of trade” (sections 11(a) and 23(g)). This paper discusses the deductibility of interest and, in particular, whether there are circumstances in which interest paid on a loan used to acquire a capital asset could be of a capital nature. The provisions of the Income Tax Act and court decisions relating to the deductibility of interest, as well as opinions expressed by authoritative writers on tax, are subjected to critical analysis. The paper first distinguishes the tests for determining whether an expense has been incurred “in the production of income” and whether the expense is “of a capital nature”. Specific court decisions relating to the deductibility of interest are then analysed. The research considers section 24J of the Act, to determine whether its provisions have settled the debate, and refers briefly to the provisions of section 11(bB), in the context of the research question. The conclusion reached in the research is that there are occasions where the courts appear to have confused the tests for determining whether interest expenditure was incurred “in the production of income” and whether it is “of a capital nature”, in certain instances have also failed to address the question of the capital or revenue nature of the interest expenditure under scrutiny, and that the matter does not appear to be settled that interest incurred on funds used to acquire a capital asset used to produce trade income is automatically deductible.
- Full Text:
- Date Issued: 2006
The relationship between Accounting 1 and Accounting 3 results
- Mazwi, Zukile, Stack, Elizabeth M
- Authors: Mazwi, Zukile , Stack, Elizabeth M
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: Conference paper
- Identifier: vital:6064 , http://hdl.handle.net/10962/d1004609
- Full Text:
- Date Issued: 2006
- Authors: Mazwi, Zukile , Stack, Elizabeth M
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: Conference paper
- Identifier: vital:6064 , http://hdl.handle.net/10962/d1004609
- Full Text:
- Date Issued: 2006
Evaluating parts-of-speech taggers for use in a text-to-scene conversion system
- Glass, Kevin R, Bangay, Shaun D
- Authors: Glass, Kevin R , Bangay, Shaun D
- Date: 2005
- Language: English
- Type: Conference paper
- Identifier: vital:6603 , http://hdl.handle.net/10962/d1009323
- Description: This paper presents parts-of-speech tagging as a first step towards an autonomous text-to-scene conversion system. It categorizes some freely available taggers, according to the techniques used by each in order to automatically identify word-classes. In addition, the performance of each identified tagger is verified experimentally. The SUSANNE corpus is used for testing and reveals the complexity of working with different tagsets, resulting in substantially lower accuracies in our tests than in those reported by the developers of each tagger. The taggers are then grouped to form a voting system to attempt to raise accuracies, but in no cases do the combined results improve upon the individual accuracies. Additionally a new metric, agreement, is tentatively proposed as an indication of confidence in the output of a group of taggers where such output cannot be validated.
- Full Text:
- Date Issued: 2005
- Authors: Glass, Kevin R , Bangay, Shaun D
- Date: 2005
- Language: English
- Type: Conference paper
- Identifier: vital:6603 , http://hdl.handle.net/10962/d1009323
- Description: This paper presents parts-of-speech tagging as a first step towards an autonomous text-to-scene conversion system. It categorizes some freely available taggers, according to the techniques used by each in order to automatically identify word-classes. In addition, the performance of each identified tagger is verified experimentally. The SUSANNE corpus is used for testing and reveals the complexity of working with different tagsets, resulting in substantially lower accuracies in our tests than in those reported by the developers of each tagger. The taggers are then grouped to form a voting system to attempt to raise accuracies, but in no cases do the combined results improve upon the individual accuracies. Additionally a new metric, agreement, is tentatively proposed as an indication of confidence in the output of a group of taggers where such output cannot be validated.
- Full Text:
- Date Issued: 2005
Learning science through two languages in South Africa
- Authors: Probyn, Margie J
- Date: 2005
- Language: English
- Type: Conference paper
- Identifier: vital:7015 , http://hdl.handle.net/10962/d1007208
- Description: [From the introduction]: South Africa is a multilingual country with eleven national languages - nine indigenous languages and the two former colonial languages of English and Afrikaans1 - recognised as official languages in the Constitution of 1996 (Constitution of the Republic of South Africa, 1996). Despite these provisions, since the democratic elections of 1994 English has expanded its position as the language of access and power with the relative influence of Afrikaans shrinking, and African languages effectively confined to functions of ‘home and hearth’. McLean and McCormick (1996: 329 in Mazrui 2002: 269) suggest that the constitutional recognition of 11 official languages in South Africa is largely 'intended and perceived as a symbolic statement and that for instrumental purposes, English remains the dominant language in South Africa'.
- Full Text:
- Date Issued: 2005
- Authors: Probyn, Margie J
- Date: 2005
- Language: English
- Type: Conference paper
- Identifier: vital:7015 , http://hdl.handle.net/10962/d1007208
- Description: [From the introduction]: South Africa is a multilingual country with eleven national languages - nine indigenous languages and the two former colonial languages of English and Afrikaans1 - recognised as official languages in the Constitution of 1996 (Constitution of the Republic of South Africa, 1996). Despite these provisions, since the democratic elections of 1994 English has expanded its position as the language of access and power with the relative influence of Afrikaans shrinking, and African languages effectively confined to functions of ‘home and hearth’. McLean and McCormick (1996: 329 in Mazrui 2002: 269) suggest that the constitutional recognition of 11 official languages in South Africa is largely 'intended and perceived as a symbolic statement and that for instrumental purposes, English remains the dominant language in South Africa'.
- Full Text:
- Date Issued: 2005
The Internet Quota System at Rhodes
- Authors: Halse, Guy A
- Date: 2005
- Language: English
- Type: Conference paper
- Identifier: vital:6608 , http://hdl.handle.net/10962/d1009519
- Full Text: false
- Date Issued: 2005
- Authors: Halse, Guy A
- Date: 2005
- Language: English
- Type: Conference paper
- Identifier: vital:6608 , http://hdl.handle.net/10962/d1009519
- Full Text: false
- Date Issued: 2005
Using a FreeBSD "cluster" to provide network services
- Authors: Siebörger, David
- Date: 2005
- Language: English
- Type: Conference paper
- Identifier: vital:6611 , http://hdl.handle.net/10962/d1009524
- Description: A presentation on how FreeBSD might be used in a load-balancing cluster, using work done at Rhodes University as a case study. Presented to a community of higher education IT practitioners in September 2005.
- Full Text:
- Date Issued: 2005
- Authors: Siebörger, David
- Date: 2005
- Language: English
- Type: Conference paper
- Identifier: vital:6611 , http://hdl.handle.net/10962/d1009524
- Description: A presentation on how FreeBSD might be used in a load-balancing cluster, using work done at Rhodes University as a case study. Presented to a community of higher education IT practitioners in September 2005.
- Full Text:
- Date Issued: 2005
Refining lecturers’ assessment practices through formal professional development at Rhodes University, Grahamstown
- Authors: Sayigh, L
- Date: 2003
- Language: English
- Type: Conference paper
- Identifier: vital:6080 , http://hdl.handle.net/10962/d1008584
- Description: In recent years, the so-called Accreditation and Registration of Assessors has given rise to much debate in the Higher Education sector. The idea that anyone assessing student learning should be required to train in order to gain a formal qualification and register as an assessor originated with the South African Qualifications Authority (SAQA) and was soon challenged within the higher education community. The Study Team appointed to investigate the implementation of the NQF (National Qualifications Framework) in 2001 recommended that registration of assessors should not be required of individuals teaching in the higher education sector if employed by an accredited institution and this recommendation was later accepted by the Department of Education and the Department of Labour in their joint consultative document entitled ‘An Interdependent National Qualifications Framework System’ (Department of Education, Department of Labour 2003). The waiving of the requirement to register assessors has been welcomed within the public higher education sector. But despite this, the need to train and qualify assessors of students’ learning remains important due to the emphasis placed on assessment by the HEQC (Higher Education Quality Committee) in its ‘Criteria for Institutional Audits’ (2004). The central issue has become how higher education institutions are to successfully train lecturers as assessors in higher education.
- Full Text:
- Date Issued: 2003
- Authors: Sayigh, L
- Date: 2003
- Language: English
- Type: Conference paper
- Identifier: vital:6080 , http://hdl.handle.net/10962/d1008584
- Description: In recent years, the so-called Accreditation and Registration of Assessors has given rise to much debate in the Higher Education sector. The idea that anyone assessing student learning should be required to train in order to gain a formal qualification and register as an assessor originated with the South African Qualifications Authority (SAQA) and was soon challenged within the higher education community. The Study Team appointed to investigate the implementation of the NQF (National Qualifications Framework) in 2001 recommended that registration of assessors should not be required of individuals teaching in the higher education sector if employed by an accredited institution and this recommendation was later accepted by the Department of Education and the Department of Labour in their joint consultative document entitled ‘An Interdependent National Qualifications Framework System’ (Department of Education, Department of Labour 2003). The waiving of the requirement to register assessors has been welcomed within the public higher education sector. But despite this, the need to train and qualify assessors of students’ learning remains important due to the emphasis placed on assessment by the HEQC (Higher Education Quality Committee) in its ‘Criteria for Institutional Audits’ (2004). The central issue has become how higher education institutions are to successfully train lecturers as assessors in higher education.
- Full Text:
- Date Issued: 2003
The biogeography of the Prosopistomatidae, with a particular emphasis on Southern African species
- Authors: Barber-James, Helen M
- Date: 2003
- Language: English
- Type: Conference paper
- Identifier: vital:6998 , http://hdl.handle.net/10962/d1008378
- Description: The mayfly family Prosopistomatidae consists of the single genus Prosopistoma Latreille. Its known distribution includes species from Africa, Madagascar, the Comores, Europe, the Levant, India, Sri Lanka, China, Vietnam, the Philippines, Malaysia, Sumatra, Java, the Solomon Islands, Papua New Guinea and northern Australia. A tropical Gondwanaland origin of the family has been suggested. No species are currently known from the Neotropical or Nearctic regions, though the family may yet be discovered in northeastern South America, since this region separated from West Africa only c.120 mya. Focussing on southern Africa, several undescribed species have recently been discovered, with interesting implications to the biogeography on a more localised scale. In the western Cape, a prosopistomatid species has been collected in the Olifants River, extending the distribution of this family further south into a more temperate region. Geological evidence indicates that the Olifants River was connected to the Orange River during the Tertiary period. Prosopistomatidae are known from the Orange River today, and the presence of the family in the Olifants River in the western Cape supports the geological evidence of the historical link between these two rivers. Another unexpected discovery was from the Buffalo River in the eastern Cape, at 33ºS. A subtropical zone extends along the east coast of South Africa as a result of the warm Agulhas current offshore, allowing the southerly extension of the distribution of more tropical species. , Research Update on Ephemeroptera & Plecoptera: Proceedings of the Tenth International Conference on Ephemeroptera, 8-11 August 2001, Perugia, Italy. University of Perugia, Perugia, Italy, pp. 263-270.
- Full Text:
- Date Issued: 2003
- Authors: Barber-James, Helen M
- Date: 2003
- Language: English
- Type: Conference paper
- Identifier: vital:6998 , http://hdl.handle.net/10962/d1008378
- Description: The mayfly family Prosopistomatidae consists of the single genus Prosopistoma Latreille. Its known distribution includes species from Africa, Madagascar, the Comores, Europe, the Levant, India, Sri Lanka, China, Vietnam, the Philippines, Malaysia, Sumatra, Java, the Solomon Islands, Papua New Guinea and northern Australia. A tropical Gondwanaland origin of the family has been suggested. No species are currently known from the Neotropical or Nearctic regions, though the family may yet be discovered in northeastern South America, since this region separated from West Africa only c.120 mya. Focussing on southern Africa, several undescribed species have recently been discovered, with interesting implications to the biogeography on a more localised scale. In the western Cape, a prosopistomatid species has been collected in the Olifants River, extending the distribution of this family further south into a more temperate region. Geological evidence indicates that the Olifants River was connected to the Orange River during the Tertiary period. Prosopistomatidae are known from the Orange River today, and the presence of the family in the Olifants River in the western Cape supports the geological evidence of the historical link between these two rivers. Another unexpected discovery was from the Buffalo River in the eastern Cape, at 33ºS. A subtropical zone extends along the east coast of South Africa as a result of the warm Agulhas current offshore, allowing the southerly extension of the distribution of more tropical species. , Research Update on Ephemeroptera & Plecoptera: Proceedings of the Tenth International Conference on Ephemeroptera, 8-11 August 2001, Perugia, Italy. University of Perugia, Perugia, Italy, pp. 263-270.
- Full Text:
- Date Issued: 2003
A bi-directional SOAP/SMS gateway service
- Halse, Guy A, Terzoli, Alfredo, Wells, George C
- Authors: Halse, Guy A , Terzoli, Alfredo , Wells, George C
- Date: 2002
- Subjects: Broadband 2 SATNAC 2002
- Language: English
- Type: Conference paper
- Identifier: vital:6600 , http://hdl.handle.net/10962/d1008293
- Description: Many applications need the ability to do real-time notification when events occur. Often the people who need to be kept aware of events are in a remote location. This paper looks at a bi-directional gateway between networked computers and the GSM short message service. The gateway is implemented as a web service, and uses the Simple Object Access Protocol to facilitate data communication. The service interacts with a database in order to facilitate retrieval of sent or received messages, as well as provide accounting abilities. It is intended as a practical proof-of-concept application demonstrating some ofdemonstrating some of the capabilities of the Simple Object Access Protocol.
- Full Text:
- Date Issued: 2002
- Authors: Halse, Guy A , Terzoli, Alfredo , Wells, George C
- Date: 2002
- Subjects: Broadband 2 SATNAC 2002
- Language: English
- Type: Conference paper
- Identifier: vital:6600 , http://hdl.handle.net/10962/d1008293
- Description: Many applications need the ability to do real-time notification when events occur. Often the people who need to be kept aware of events are in a remote location. This paper looks at a bi-directional gateway between networked computers and the GSM short message service. The gateway is implemented as a web service, and uses the Simple Object Access Protocol to facilitate data communication. The service interacts with a database in order to facilitate retrieval of sent or received messages, as well as provide accounting abilities. It is intended as a practical proof-of-concept application demonstrating some ofdemonstrating some of the capabilities of the Simple Object Access Protocol.
- Full Text:
- Date Issued: 2002
Accelerated sludge solubilisation under sulphate reducing conditions: the effect of hydrolytic enzymes on sludge floc size distribution and EPS composition
- Akhurst, P, Rose, Peter D, Whiteley, Chris G, Pletschke, Brett I
- Authors: Akhurst, P , Rose, Peter D , Whiteley, Chris G , Pletschke, Brett I
- Date: 2002
- Language: English
- Type: Conference paper
- Identifier: vital:6455 , http://hdl.handle.net/10962/d1010430
- Description: Extracellular polymeric substances (EPS) are the construction materials for microbial aggregates such as biofilms, flocs and sludge, and greatly contribute to the structural integrity of sludge flocs in wastewater treatment processes. The loss of integrity of the sewage sludge floc is believed to be due to enhanced hydrolysis of important structural components such as lignin, protein and cellulose in the sludge floc matrix. The mechanism of enhanced sludge floc fracture, due to the action of enzymes hydrolysing these structural components, remains a key element in our understanding of how the floc integrity in systems utilising a sulphate reducing system is compromised. A range of relatively non-specific exogenous enzymes (ß-glucosidase, cellulase, proteases: trypsin, pronase E and chymotrypsin) were added to a sulphidogenic bioreactor- (containing both sulphate reducing bacteria (SRB) and a methanogenic bacterial system) and a (control) methanogenic bioreactor sample, and the effect of these enzymes on sludge floc size (diameter) distribution and EPS composition was investigated. Sludge samples from the bioreactors were examined under bright field and differential interference contrast light microscopy. Proteolytic and glucohydrolytic activity of the enzymes were monitored using standard enzyme assaying techniques, and Bradford, Somogyi-Nelson, and total carbohydrate assays were performed to establish the composition of the EPS (after extraction with 3% (v/v) glutaraldehyde and Sephacryl S-400 size exclusion chromatography). Sludge flocs present in the sulphidogenic environment of the sulphidogenic bioreactor were found to have smaller diameters than their counterparts present in the methanogenic bioreactor. The addition of hydrolytic (i.e. proteolytic and glycohydrolytic) enzymes resulted in an increased rate of matrix hydrolysis, leading to increased rates of floc fracture and deflocculation. The presence of ß-glucosidase, cellulase, and proteases naturally residing within the sludge floc was confirmed. We propose that the addition of commercially available enzymes may be prohibitively costly on a large scale, and that the activity of the enzymes naturally residing within the floc matrix be optimised or enhanced. As the bulk of the EPS was shown to be composed of mainly polysaccharides, we propose that by increasing the activity of the naturally occurring ß-glucosidases residing within the floc matrix, the process of deflocculation may be enhanced. As sulphide has been shown to increase the activity of this very important key enzyme, we propose that this is one of the contributing factors why sludge solubilisation is accelerated under sulphate reducing conditions.
- Full Text:
- Date Issued: 2002
- Authors: Akhurst, P , Rose, Peter D , Whiteley, Chris G , Pletschke, Brett I
- Date: 2002
- Language: English
- Type: Conference paper
- Identifier: vital:6455 , http://hdl.handle.net/10962/d1010430
- Description: Extracellular polymeric substances (EPS) are the construction materials for microbial aggregates such as biofilms, flocs and sludge, and greatly contribute to the structural integrity of sludge flocs in wastewater treatment processes. The loss of integrity of the sewage sludge floc is believed to be due to enhanced hydrolysis of important structural components such as lignin, protein and cellulose in the sludge floc matrix. The mechanism of enhanced sludge floc fracture, due to the action of enzymes hydrolysing these structural components, remains a key element in our understanding of how the floc integrity in systems utilising a sulphate reducing system is compromised. A range of relatively non-specific exogenous enzymes (ß-glucosidase, cellulase, proteases: trypsin, pronase E and chymotrypsin) were added to a sulphidogenic bioreactor- (containing both sulphate reducing bacteria (SRB) and a methanogenic bacterial system) and a (control) methanogenic bioreactor sample, and the effect of these enzymes on sludge floc size (diameter) distribution and EPS composition was investigated. Sludge samples from the bioreactors were examined under bright field and differential interference contrast light microscopy. Proteolytic and glucohydrolytic activity of the enzymes were monitored using standard enzyme assaying techniques, and Bradford, Somogyi-Nelson, and total carbohydrate assays were performed to establish the composition of the EPS (after extraction with 3% (v/v) glutaraldehyde and Sephacryl S-400 size exclusion chromatography). Sludge flocs present in the sulphidogenic environment of the sulphidogenic bioreactor were found to have smaller diameters than their counterparts present in the methanogenic bioreactor. The addition of hydrolytic (i.e. proteolytic and glycohydrolytic) enzymes resulted in an increased rate of matrix hydrolysis, leading to increased rates of floc fracture and deflocculation. The presence of ß-glucosidase, cellulase, and proteases naturally residing within the sludge floc was confirmed. We propose that the addition of commercially available enzymes may be prohibitively costly on a large scale, and that the activity of the enzymes naturally residing within the floc matrix be optimised or enhanced. As the bulk of the EPS was shown to be composed of mainly polysaccharides, we propose that by increasing the activity of the naturally occurring ß-glucosidases residing within the floc matrix, the process of deflocculation may be enhanced. As sulphide has been shown to increase the activity of this very important key enzyme, we propose that this is one of the contributing factors why sludge solubilisation is accelerated under sulphate reducing conditions.
- Full Text:
- Date Issued: 2002
Open source in South African schools : two case studies
- Halse, Guy A, Terzoli, Alfredo
- Authors: Halse, Guy A , Terzoli, Alfredo
- Date: 2002
- Subjects: Open source
- Language: English
- Type: Conference paper
- Identifier: vital:6601 , http://hdl.handle.net/10962/d1009321
- Description: One of the major problems facing schools in South Africa is the difficulty in obtaining modern, up-to-date computer facilities. This paper looks at the use of open source solutions in two government schools in South Africa to demonstrate that it is possible for schools to utilise almost any existing computer to provide effective network solutions.
- Full Text:
- Date Issued: 2002
- Authors: Halse, Guy A , Terzoli, Alfredo
- Date: 2002
- Subjects: Open source
- Language: English
- Type: Conference paper
- Identifier: vital:6601 , http://hdl.handle.net/10962/d1009321
- Description: One of the major problems facing schools in South Africa is the difficulty in obtaining modern, up-to-date computer facilities. This paper looks at the use of open source solutions in two government schools in South Africa to demonstrate that it is possible for schools to utilise almost any existing computer to provide effective network solutions.
- Full Text:
- Date Issued: 2002
The land question in South Africa, Zimbabwe and Kenya: a geographical perspective on resource endowment
- Fox, Roddy C, Rowntree, Kate M
- Authors: Fox, Roddy C , Rowntree, Kate M
- Date: 2002
- Language: English
- Type: Conference paper
- Identifier: vital:6664 , http://hdl.handle.net/10962/d1006671
- Description: In sharp contrast to the debates concerning land policy, land tenure and sustainable resource management in South Africa is any input concerning the geographical distribution of land productivity. This paper attempts to redress this imbalance by providing an empirical investigation of land potential in South Africa. In this way we intend to provide the crucial context for policy and academic studies of the land issue in South Africa. Furthermore, we will undertake our study in such a way that comparison can be made to Zimbabwe and Kenya where the land issue has been such a critical component of the post-colonial development process. Theoretically our work is contextualised within the debates surrounding the importance of geographical endowments, institutions and policies in the development process.
- Full Text:
- Date Issued: 2002
- Authors: Fox, Roddy C , Rowntree, Kate M
- Date: 2002
- Language: English
- Type: Conference paper
- Identifier: vital:6664 , http://hdl.handle.net/10962/d1006671
- Description: In sharp contrast to the debates concerning land policy, land tenure and sustainable resource management in South Africa is any input concerning the geographical distribution of land productivity. This paper attempts to redress this imbalance by providing an empirical investigation of land potential in South Africa. In this way we intend to provide the crucial context for policy and academic studies of the land issue in South Africa. Furthermore, we will undertake our study in such a way that comparison can be made to Zimbabwe and Kenya where the land issue has been such a critical component of the post-colonial development process. Theoretically our work is contextualised within the debates surrounding the importance of geographical endowments, institutions and policies in the development process.
- Full Text:
- Date Issued: 2002
Mentoring and prospects for teacher development - a South African perspective
- Probyn, Margie, Van der Mescht, Hennie
- Authors: Probyn, Margie , Van der Mescht, Hennie
- Date: 2001
- Language: English
- Type: Conference paper
- Identifier: vital:6090 , http://hdl.handle.net/10962/d1009744
- Description: School-based mentoring has developed in response to a number of factors pertaining to the pre-service education of student teachers and the in-service professional development of experienced teachers. Traditionally teacher education has consisted of university-based theory with school-based practice, based on an understanding of professional learning as ‘theory into practice’. One of the problems with this model is that theory may come to seem too remote from practice, and that practice appears untheorised by remaining implicit and unproblematised. The one-year teachers’ diploma course offered by the Rhodes University Education Department incorporates a ten-week teaching practice slot. This protracted period has been useful in allowing frequent and consistent contact between university tutors and student teachers, and between mentor teachers and student teachers. Where the system has not been strong is in enabling meaningful collaboration among all three parties. A pilot school-based mentoring programme was thus implemented in 1999, involving English First and Second Language student teachers, the two university tutors and seven mentor teachers. Ongoing evaluative research revealed that the programme was welcomed by all, and that the student teachers in particular gained much in the way of learning to be critically reflexive in a non-threatening environment. However, the research also uncovered areas that need to be developed. Student teachers, for example, need guidance in terms of learning how to talk about teaching; mentor teachers need to develop the confidence and expertise required to open up their practice in a critically constructive context. On the strength of the programme’s success, the Education Department has extended school-based mentoring to all HDE students, and is exploring ways of setting up courses through which other educators (such as EDOs) may receive training in pre- and in-service teacher mentoring.
- Full Text:
- Date Issued: 2001
- Authors: Probyn, Margie , Van der Mescht, Hennie
- Date: 2001
- Language: English
- Type: Conference paper
- Identifier: vital:6090 , http://hdl.handle.net/10962/d1009744
- Description: School-based mentoring has developed in response to a number of factors pertaining to the pre-service education of student teachers and the in-service professional development of experienced teachers. Traditionally teacher education has consisted of university-based theory with school-based practice, based on an understanding of professional learning as ‘theory into practice’. One of the problems with this model is that theory may come to seem too remote from practice, and that practice appears untheorised by remaining implicit and unproblematised. The one-year teachers’ diploma course offered by the Rhodes University Education Department incorporates a ten-week teaching practice slot. This protracted period has been useful in allowing frequent and consistent contact between university tutors and student teachers, and between mentor teachers and student teachers. Where the system has not been strong is in enabling meaningful collaboration among all three parties. A pilot school-based mentoring programme was thus implemented in 1999, involving English First and Second Language student teachers, the two university tutors and seven mentor teachers. Ongoing evaluative research revealed that the programme was welcomed by all, and that the student teachers in particular gained much in the way of learning to be critically reflexive in a non-threatening environment. However, the research also uncovered areas that need to be developed. Student teachers, for example, need guidance in terms of learning how to talk about teaching; mentor teachers need to develop the confidence and expertise required to open up their practice in a critically constructive context. On the strength of the programme’s success, the Education Department has extended school-based mentoring to all HDE students, and is exploring ways of setting up courses through which other educators (such as EDOs) may receive training in pre- and in-service teacher mentoring.
- Full Text:
- Date Issued: 2001
XML to facilitate management of multi-vendor networks
- Halse, Guy A, Wells, George C, Terzoli, Alfredo
- Authors: Halse, Guy A , Wells, George C , Terzoli, Alfredo
- Date: 2001
- Subjects: XML Network Management SNMP
- Language: English
- Type: Conference paper
- Identifier: vital:6602 , http://hdl.handle.net/10962/d1009322
- Description: Many standards aimed at managing networks currently exist, and yet networks remain notoriously difficult to maintain. Template-based management systems go a long way towards solving this problem. By developing an XML based language to describe network elements, as well as the topology of a network, we can create tools that are free from vendor specific idiosyncrasies, and are capable of managing both today’s networks and those of the future.
- Full Text:
- Date Issued: 2001
- Authors: Halse, Guy A , Wells, George C , Terzoli, Alfredo
- Date: 2001
- Subjects: XML Network Management SNMP
- Language: English
- Type: Conference paper
- Identifier: vital:6602 , http://hdl.handle.net/10962/d1009322
- Description: Many standards aimed at managing networks currently exist, and yet networks remain notoriously difficult to maintain. Template-based management systems go a long way towards solving this problem. By developing an XML based language to describe network elements, as well as the topology of a network, we can create tools that are free from vendor specific idiosyncrasies, and are capable of managing both today’s networks and those of the future.
- Full Text:
- Date Issued: 2001
Bioequivalence testing of topical dermatological formulations, the gap between science and legislation
- Schwarb, Fabian P, Smith, Eric W, Haigh, John M, Surber, Christian
- Authors: Schwarb, Fabian P , Smith, Eric W , Haigh, John M , Surber, Christian
- Date: 1998
- Language: English
- Type: Conference paper
- Identifier: vital:6341 , http://hdl.handle.net/10962/d1006608
- Description: Bioavailability concerns for topical dermatological products are complex and it is especially difficult to determine the bioequivalence of similar topical formulations. Since only small amounts of drug dispersed in an appropriate vehicle are applied to the skin, the amount of drug that actually reaches the systemic circulation is often too small to be easily quantified. Additionally, it can be argued that the relevance of any serum/plasma concentration-time curve of a topical agent is questionable, since the curve reflects the amount of drug after the active moiety has left the site of action. For some topical drugs e.g., topical corticosteroids, it is possible to perform a pharmacodynamic bioassay to obtain acceptable bioequivalence data. In this case, the intensity of the side effect of blanching (vasoconstriction) in the skin caused by topical corticosteroids can be measured. The response is directly proportional to the clinical efficacy, and the skin blanching assay has proved to be a reliable procedure for the determination of topical corticosteroid bioavailability. Recently, we had sight of the results of a topical bioequivalence study, which was conducted for the registration of a new generic corticosteroid cream formulation. In this trial the new formulation was compared to two equivalent product from the local market and bioequivalence was demonstrated by the investigators for all three products. These results were examined with interest as the respective reference products have been used repeatedly as standard formulations in our laboratory. However, one of these reference formulations has consistently shown superior bioavailability in our trials, but was not demonstrated to be superior in the study results examined. In the present publication an overview of topical bioequivalence testing in general is given and the difficulties occurring in practice, for topical corticosteroid formulations in particular, are demonstrated.
- Full Text:
- Date Issued: 1998
- Authors: Schwarb, Fabian P , Smith, Eric W , Haigh, John M , Surber, Christian
- Date: 1998
- Language: English
- Type: Conference paper
- Identifier: vital:6341 , http://hdl.handle.net/10962/d1006608
- Description: Bioavailability concerns for topical dermatological products are complex and it is especially difficult to determine the bioequivalence of similar topical formulations. Since only small amounts of drug dispersed in an appropriate vehicle are applied to the skin, the amount of drug that actually reaches the systemic circulation is often too small to be easily quantified. Additionally, it can be argued that the relevance of any serum/plasma concentration-time curve of a topical agent is questionable, since the curve reflects the amount of drug after the active moiety has left the site of action. For some topical drugs e.g., topical corticosteroids, it is possible to perform a pharmacodynamic bioassay to obtain acceptable bioequivalence data. In this case, the intensity of the side effect of blanching (vasoconstriction) in the skin caused by topical corticosteroids can be measured. The response is directly proportional to the clinical efficacy, and the skin blanching assay has proved to be a reliable procedure for the determination of topical corticosteroid bioavailability. Recently, we had sight of the results of a topical bioequivalence study, which was conducted for the registration of a new generic corticosteroid cream formulation. In this trial the new formulation was compared to two equivalent product from the local market and bioequivalence was demonstrated by the investigators for all three products. These results were examined with interest as the respective reference products have been used repeatedly as standard formulations in our laboratory. However, one of these reference formulations has consistently shown superior bioavailability in our trials, but was not demonstrated to be superior in the study results examined. In the present publication an overview of topical bioequivalence testing in general is given and the difficulties occurring in practice, for topical corticosteroid formulations in particular, are demonstrated.
- Full Text:
- Date Issued: 1998
Chromametry: measuring precision of diurnal and local variation of human forearm skin colour
- Schwarb, Fabian P, Smith, Eric W, Haigh, John M, Surber, Christian
- Authors: Schwarb, Fabian P , Smith, Eric W , Haigh, John M , Surber, Christian
- Date: 1998
- Language: English
- Type: Conference paper
- Identifier: vital:6343 , http://hdl.handle.net/10962/d1006610
- Description: Chromameters are compact portable instruments used for the assessment of surface colour based on the tristimulus analysis of a reflected xenon light pulse, and have been used for the quantification of erythema in the study of irritant dermatitis, and corticosteroid-induced skin blanching in the vasoconstriction assay. The variability and the reproducibility of chromameter results were investigated since it is known that the location and application force of the measuring head on the skin and the orthostatic maneuver of the arms influence the colour measurement. Furthermore the diurnal variation and the homogeneity of forearm skin colour were investigated.
- Full Text:
- Date Issued: 1998
- Authors: Schwarb, Fabian P , Smith, Eric W , Haigh, John M , Surber, Christian
- Date: 1998
- Language: English
- Type: Conference paper
- Identifier: vital:6343 , http://hdl.handle.net/10962/d1006610
- Description: Chromameters are compact portable instruments used for the assessment of surface colour based on the tristimulus analysis of a reflected xenon light pulse, and have been used for the quantification of erythema in the study of irritant dermatitis, and corticosteroid-induced skin blanching in the vasoconstriction assay. The variability and the reproducibility of chromameter results were investigated since it is known that the location and application force of the measuring head on the skin and the orthostatic maneuver of the arms influence the colour measurement. Furthermore the diurnal variation and the homogeneity of forearm skin colour were investigated.
- Full Text:
- Date Issued: 1998