Links between the local trade in natural products, livelihoods and poverty alleviation in a semi-arid region of South Africa
- Shackleton, Sheona E, Campbell, Bruce, Lotz-Sisitka, Heila, Shackleton, Charlie M
- Authors: Shackleton, Sheona E , Campbell, Bruce , Lotz-Sisitka, Heila , Shackleton, Charlie M
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181246 , vital:43712 , xlink:href="https://doi.org/10.1016/j.worlddev.2007.03.003"
- Description: Can the local commercialization of natural products contribute to reduced poverty and vulnerability? Commentary on this issue is mixed, with some observers being quite optimistic, while others hold a counterview. This paper explores the poverty alleviation potential of four products traded in Bushbuckridge, South Africa—traditional brooms, reed mats, woodcraft, and “marula” beer. While key in enhancing the livelihood security of the poorest households, these products were unlikely to provide a route out of poverty for most, although there were exceptions. Incomes often surpassed local wage rates, and some producers obtained returns equivalent to the minimum wage. Non-financial benefits such as the opportunity to work from home were highly rated, and the trade was found to represent a range of livelihood strategies both within and across products.
- Full Text:
- Date Issued: 2008
- Authors: Shackleton, Sheona E , Campbell, Bruce , Lotz-Sisitka, Heila , Shackleton, Charlie M
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181246 , vital:43712 , xlink:href="https://doi.org/10.1016/j.worlddev.2007.03.003"
- Description: Can the local commercialization of natural products contribute to reduced poverty and vulnerability? Commentary on this issue is mixed, with some observers being quite optimistic, while others hold a counterview. This paper explores the poverty alleviation potential of four products traded in Bushbuckridge, South Africa—traditional brooms, reed mats, woodcraft, and “marula” beer. While key in enhancing the livelihood security of the poorest households, these products were unlikely to provide a route out of poverty for most, although there were exceptions. Incomes often surpassed local wage rates, and some producers obtained returns equivalent to the minimum wage. Non-financial benefits such as the opportunity to work from home were highly rated, and the trade was found to represent a range of livelihood strategies both within and across products.
- Full Text:
- Date Issued: 2008
Links between water temperatures, ecological responses and flow rates: a framework for establishing water temperature guidelines for the ecological reserve
- Rivers-Moore, Nick A, Hughes, Denis A, Mantel, Sukhmani K M
- Authors: Rivers-Moore, Nick A , Hughes, Denis A , Mantel, Sukhmani K M
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438295 , vital:73449 , ISBN 978-1-77005-738-8 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/KV214-CONSERVATION.pdf
- Description: Global ecosystems face unprecedented crises in habitat fragmentation, destruction and ultimately extinction (Groves, 2003), and of all the vary-ing ecological systems rivers are the most neglected and endangered (Groves, 2003; Driver, et al., 2005; Roux et al., 2005). The greatest threat to these systems is the loss or degradation of natural habitat and processes (Driver et al., 2005), and water temperatures, after flow vol-umes, are a primary abiotic driver of species patterns within river sys-tems. Stuckenberg (1969) highlighted the links between temperature, topography and faunal assemblages, while Rivers-Moore et al.(2004) highlights the major impacts of water temperatures on organisms, and illustrate how water temperatures are one of the primary environmental drivers structuring fish communities in the Sabie River, arguably the most icthyologically species-rich river in South Africa.
- Full Text:
- Date Issued: 2008
- Authors: Rivers-Moore, Nick A , Hughes, Denis A , Mantel, Sukhmani K M
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438295 , vital:73449 , ISBN 978-1-77005-738-8 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/KV214-CONSERVATION.pdf
- Description: Global ecosystems face unprecedented crises in habitat fragmentation, destruction and ultimately extinction (Groves, 2003), and of all the vary-ing ecological systems rivers are the most neglected and endangered (Groves, 2003; Driver, et al., 2005; Roux et al., 2005). The greatest threat to these systems is the loss or degradation of natural habitat and processes (Driver et al., 2005), and water temperatures, after flow vol-umes, are a primary abiotic driver of species patterns within river sys-tems. Stuckenberg (1969) highlighted the links between temperature, topography and faunal assemblages, while Rivers-Moore et al.(2004) highlights the major impacts of water temperatures on organisms, and illustrate how water temperatures are one of the primary environmental drivers structuring fish communities in the Sabie River, arguably the most icthyologically species-rich river in South Africa.
- Full Text:
- Date Issued: 2008
Living in Rhini : a 2007 update on the 1999 Social Indicators Report
- Authors: Moller, Valerie
- Date: 2008
- Language: English
- Type: Book , text
- Identifier: vital:541 , http://hdl.handle.net/10962/d1010770 , ISBN 9780868104461
- Description: [From the preface]: This report is a sequel to ‘Living in Grahamstown East/Rini – A Social Indicators report’ published by the Institute of Social and Economic Research in 2001 as Number 6 in its Research Report series. The No. 6 monograph was based on results of a sample survey of householders conducted in May 1999 in the area of Makana generally known as Grahamstown East or Rini at that time. This report is based on information collected in November 2007 in the same area. The ‘Living in Rhini’ project takes its title from a series of reports on social indicators initiated by Statistics South Africa (then Central Statistical Services). The popular series aimed to communicate to ordinary people the statistics on living conditions in various parts of the country. The 1999 sample survey conducted among 862 households from all neighbourhoods of Grahamstown East/Rini was a large survey by most standards. The 2007 sample similarly comprises over 1000 households spread over all neighbourhoods of Rhini including the ones developed since 1999.
- Full Text:
- Date Issued: 2008
- Authors: Moller, Valerie
- Date: 2008
- Language: English
- Type: Book , text
- Identifier: vital:541 , http://hdl.handle.net/10962/d1010770 , ISBN 9780868104461
- Description: [From the preface]: This report is a sequel to ‘Living in Grahamstown East/Rini – A Social Indicators report’ published by the Institute of Social and Economic Research in 2001 as Number 6 in its Research Report series. The No. 6 monograph was based on results of a sample survey of householders conducted in May 1999 in the area of Makana generally known as Grahamstown East or Rini at that time. This report is based on information collected in November 2007 in the same area. The ‘Living in Rhini’ project takes its title from a series of reports on social indicators initiated by Statistics South Africa (then Central Statistical Services). The popular series aimed to communicate to ordinary people the statistics on living conditions in various parts of the country. The 1999 sample survey conducted among 862 households from all neighbourhoods of Grahamstown East/Rini was a large survey by most standards. The 2007 sample similarly comprises over 1000 households spread over all neighbourhoods of Rhini including the ones developed since 1999.
- Full Text:
- Date Issued: 2008
Local Institutions for Water Governance: A Story of the Development of a Water User Association and Catchment Forum in the Kat River Valley, Eastern Cape
- Burt, Jane C, McMaster, Alistair, Rowntree, Kate, Berold, Robert
- Authors: Burt, Jane C , McMaster, Alistair , Rowntree, Kate , Berold, Robert
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433040 , vital:72927 , xlink:href="https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/TT 295 -web-Water policy and General.pdf"
- Description: This report describes the development of water resource management organisations (institutions) in the Kat River Valley from 1997 to 2006. The two organisations described here – the Kat River Valley Water User Association and the Kat River Catchment Forum – are given separate narratives for the sake of clarity, although they developed in close association. Both these organisations were nurtured and supported as a result of a research process by members of the Catchment Research Group (CRG) from the Department of Geography at Rhodes University. Funding came largely through the Water Research Commission (WRC).
- Full Text:
- Date Issued: 2008
- Authors: Burt, Jane C , McMaster, Alistair , Rowntree, Kate , Berold, Robert
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433040 , vital:72927 , xlink:href="https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/TT 295 -web-Water policy and General.pdf"
- Description: This report describes the development of water resource management organisations (institutions) in the Kat River Valley from 1997 to 2006. The two organisations described here – the Kat River Valley Water User Association and the Kat River Catchment Forum – are given separate narratives for the sake of clarity, although they developed in close association. Both these organisations were nurtured and supported as a result of a research process by members of the Catchment Research Group (CRG) from the Department of Geography at Rhodes University. Funding came largely through the Water Research Commission (WRC).
- Full Text:
- Date Issued: 2008
Media consumption and everyday life
- Authors: Strelitz, Larry N
- Date: 2008
- Language: English
- Type: text , Conference paper
- Identifier: vital:6324 , http://hdl.handle.net/10962/d1008550
- Description: I see this inaugural lecture as an opportunity to trace my journey into the field of media studies, showing how significant youthful experiences with the media set me off on my particular research trajectory. In this address I will use the umbrella term ‘mass media’ to cover both the traditional news media as well as forms of popular culture such as soap operas, popular music and so on. Sometimes we use the terms ‘popular culture’ and ‘mass media’ interchangeably as they both constitute the cultural life of ordinary people.
- Full Text:
- Date Issued: 2008
- Authors: Strelitz, Larry N
- Date: 2008
- Language: English
- Type: text , Conference paper
- Identifier: vital:6324 , http://hdl.handle.net/10962/d1008550
- Description: I see this inaugural lecture as an opportunity to trace my journey into the field of media studies, showing how significant youthful experiences with the media set me off on my particular research trajectory. In this address I will use the umbrella term ‘mass media’ to cover both the traditional news media as well as forms of popular culture such as soap operas, popular music and so on. Sometimes we use the terms ‘popular culture’ and ‘mass media’ interchangeably as they both constitute the cultural life of ordinary people.
- Full Text:
- Date Issued: 2008
Mussolini's moment: Roy Sargeant directs The Merchant of Venice at Maynardville, January, 2007
- Authors: Wright, Laurence
- Date: 2008
- Language: English
- Type: text , article
- Identifier: vital:7047 , http://hdl.handle.net/10962/d1007389 , http://hdl.handle.net/10520/EJC48107
- Description: preprint , What an inspired choice of play for this year’s Maynardville offering! With the national scene strewn with trials and rumours of trials, all of them vital to the quality of life citizens of this fair city beneath the beautiful mountain (‘Belmont’) may hope to enjoy in the future, Shakespeare’s cliff-hanger about the use and abuse of the law couldn’t be more apt.
- Full Text:
- Date Issued: 2008
- Authors: Wright, Laurence
- Date: 2008
- Language: English
- Type: text , article
- Identifier: vital:7047 , http://hdl.handle.net/10962/d1007389 , http://hdl.handle.net/10520/EJC48107
- Description: preprint , What an inspired choice of play for this year’s Maynardville offering! With the national scene strewn with trials and rumours of trials, all of them vital to the quality of life citizens of this fair city beneath the beautiful mountain (‘Belmont’) may hope to enjoy in the future, Shakespeare’s cliff-hanger about the use and abuse of the law couldn’t be more apt.
- Full Text:
- Date Issued: 2008
Not an astute political thinker or visionary
- Authors: Maylam, Paul
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449993 , vital:74874 , https://www.scielo.org.za/pdf/hist/v53n1/19.pdf
- Description: Colin Eglin served as member of parliament for thirty-three years (1958-1961, 1974- 2004), under seven prime ministers or presidents (from Strijdom to Mbeki), and under five different constitutions (the Union Constitution, the Republican, the Tricameral, the 1994 Interim, and the final 1996 Constitution). Moreover during his parliamentary career he belonged to no less than six political parties (the United Party, the Progressive Party, the Progressive Reform Party, the Progressive Federal Party, the Democratic Party, and the Democratic Alliance). This is not to suggest at all that Eglin was one of those party-hopping opportunists that have come to bedevil South African politics in recent years. Far from it – Eglin only once switched parties, being one of the original “Prog” MPs who left the decaying, ever more conservative United Party in 1959 and became one of the founding MPs of the Progressive Party. Thereafter all his changing party affiliations would result from mergers and realignments in parliamentary opposition politics – realignments that always kept the “Progs” at the core.
- Full Text:
- Date Issued: 2008
- Authors: Maylam, Paul
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449993 , vital:74874 , https://www.scielo.org.za/pdf/hist/v53n1/19.pdf
- Description: Colin Eglin served as member of parliament for thirty-three years (1958-1961, 1974- 2004), under seven prime ministers or presidents (from Strijdom to Mbeki), and under five different constitutions (the Union Constitution, the Republican, the Tricameral, the 1994 Interim, and the final 1996 Constitution). Moreover during his parliamentary career he belonged to no less than six political parties (the United Party, the Progressive Party, the Progressive Reform Party, the Progressive Federal Party, the Democratic Party, and the Democratic Alliance). This is not to suggest at all that Eglin was one of those party-hopping opportunists that have come to bedevil South African politics in recent years. Far from it – Eglin only once switched parties, being one of the original “Prog” MPs who left the decaying, ever more conservative United Party in 1959 and became one of the founding MPs of the Progressive Party. Thereafter all his changing party affiliations would result from mergers and realignments in parliamentary opposition politics – realignments that always kept the “Progs” at the core.
- Full Text:
- Date Issued: 2008
On academic freedom
- Authors: Pityana, Barney
- Date: 2008
- Subjects: Academic Freedom -- South Africa Universities and colleges -- South Africa Equality Liberty Education and state -- South Africa Education, Higher -- South Africa
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/751 , vital:19987
- Description: Traditionally, higher education has formed the vanguard of ideological persuasion and even indoctrination, in support of political and social change. We should not be surprised then, that the converse also applies. Where an existing order is threatened, those intellectuals who do not toe the line are often vilified, marginalised and even worse. Many of the great revolutions have commenced with a thorough purging of intellectuals. History will testify to that. Furthermore, where the State funds higher education institutions, then notions of academic freedom will always be tempered by the expectation of some sort of reciprocal loyalty.
- Full Text:
- Date Issued: 2008
- Authors: Pityana, Barney
- Date: 2008
- Subjects: Academic Freedom -- South Africa Universities and colleges -- South Africa Equality Liberty Education and state -- South Africa Education, Higher -- South Africa
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/751 , vital:19987
- Description: Traditionally, higher education has formed the vanguard of ideological persuasion and even indoctrination, in support of political and social change. We should not be surprised then, that the converse also applies. Where an existing order is threatened, those intellectuals who do not toe the line are often vilified, marginalised and even worse. Many of the great revolutions have commenced with a thorough purging of intellectuals. History will testify to that. Furthermore, where the State funds higher education institutions, then notions of academic freedom will always be tempered by the expectation of some sort of reciprocal loyalty.
- Full Text:
- Date Issued: 2008
Opensource software and localisation in indigenous South African languages with Pootle
- Dalvit, Lorenzo, Terzoli, Alfredo, Wolff, F
- Authors: Dalvit, Lorenzo , Terzoli, Alfredo , Wolff, F
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428496 , vital:72515 , https://citeseerx.ist.psu.edu/document?repid=rep1andtype=pdfanddoi=912f3d0d94f0268467e1d790fd7780f14d9c4e44
- Description: The majority of the South African population is not fully proficient in Eng-lish. Besides access to the necessary infrastructure, many Africans lack epistemological access to the ICT world simply because of linguistic reasons. Limited availability of resources and lack of interest for the promotion of African languages in the ICT domain among their speakers are often blamed for this. The opensource community has been particu-larly responsive to the needs of this portion of the population, and a vari-ety of software is already available in African languages. Translate. org. za, an NGO committed to the development of opensource software in all 11 South African languages, has been particularly active with respect to this. On the one hand, they have developed a Webbased application to support collaborative translation online. On the other, they have part-nered with various institutions to organise translation efforts, mainly rely-ing on volunteers. In this paper we describe an experience showing how these two models can be used to address issues of lack of resources and support for the use of African languages in the ICT domain.
- Full Text:
- Date Issued: 2008
- Authors: Dalvit, Lorenzo , Terzoli, Alfredo , Wolff, F
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428496 , vital:72515 , https://citeseerx.ist.psu.edu/document?repid=rep1andtype=pdfanddoi=912f3d0d94f0268467e1d790fd7780f14d9c4e44
- Description: The majority of the South African population is not fully proficient in Eng-lish. Besides access to the necessary infrastructure, many Africans lack epistemological access to the ICT world simply because of linguistic reasons. Limited availability of resources and lack of interest for the promotion of African languages in the ICT domain among their speakers are often blamed for this. The opensource community has been particu-larly responsive to the needs of this portion of the population, and a vari-ety of software is already available in African languages. Translate. org. za, an NGO committed to the development of opensource software in all 11 South African languages, has been particularly active with respect to this. On the one hand, they have developed a Webbased application to support collaborative translation online. On the other, they have part-nered with various institutions to organise translation efforts, mainly rely-ing on volunteers. In this paper we describe an experience showing how these two models can be used to address issues of lack of resources and support for the use of African languages in the ICT domain.
- Full Text:
- Date Issued: 2008
Pan-African multilateralism: transformative or disconnected?
- Authors: Bischoff, Paul, 1954-
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161452 , vital:40628 , https://doi.org/10.1080/02589340802366968
- Description: Despite a multitude of international institutions on the African continent, worldwide Africa's multilateralism has generally received little attention. Yet, with the emergence of the African Union (AU) and its institutions, questions arise about its character. Will rhetoric and state symbolism take the place of substance or will the space opened up for democracy and civil society participation allow for greater democratically informed sustainability? With this in mind, the article addresses the issue to what extent the character of African multilateralism continues to display features of disconnectedness as opposed to those of transformation, where its institutions address issues of uneven development in concert with civil society concerns.
- Full Text:
- Date Issued: 2008
- Authors: Bischoff, Paul, 1954-
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161452 , vital:40628 , https://doi.org/10.1080/02589340802366968
- Description: Despite a multitude of international institutions on the African continent, worldwide Africa's multilateralism has generally received little attention. Yet, with the emergence of the African Union (AU) and its institutions, questions arise about its character. Will rhetoric and state symbolism take the place of substance or will the space opened up for democracy and civil society participation allow for greater democratically informed sustainability? With this in mind, the article addresses the issue to what extent the character of African multilateralism continues to display features of disconnectedness as opposed to those of transformation, where its institutions address issues of uneven development in concert with civil society concerns.
- Full Text:
- Date Issued: 2008
Participation, situated culture, and practical reason
- Lotz-Sisitka, Heila, O'Donoghue, Rob B
- Authors: Lotz-Sisitka, Heila , O'Donoghue, Rob B
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/437436 , vital:73378 , ISBN 978-1-4020-6415-9 , https://link.springer.com/chapter/10.1007/978-1-4020-6416-6_7
- Description: This chapter examines the emergence of participatory education as both a central feature and a terrain of ambivalence within the develop-ing landscape of environmental education in South Africa. From its roots in nature experience activities through to more socially critical forms of environmental education, participatory imperatives in this area have yet to address sufficiently the conceptual and practical challenges inherent in pedagogies of participation. We argue that more recent de-velopments reveal similar anomalies, such that participatory education in South Africa has now become an idealised and techniqued logic of practice.
- Full Text:
- Date Issued: 2008
- Authors: Lotz-Sisitka, Heila , O'Donoghue, Rob B
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/437436 , vital:73378 , ISBN 978-1-4020-6415-9 , https://link.springer.com/chapter/10.1007/978-1-4020-6416-6_7
- Description: This chapter examines the emergence of participatory education as both a central feature and a terrain of ambivalence within the develop-ing landscape of environmental education in South Africa. From its roots in nature experience activities through to more socially critical forms of environmental education, participatory imperatives in this area have yet to address sufficiently the conceptual and practical challenges inherent in pedagogies of participation. We argue that more recent de-velopments reveal similar anomalies, such that participatory education in South Africa has now become an idealised and techniqued logic of practice.
- Full Text:
- Date Issued: 2008
Phosphorescence of orthopaedic–grade ultra high molecular weight polyethylene
- Authors: Chithambo, Makaiko L
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125617 , vital:35801 , https://doi.10.1002/pssc.200776802
- Description: Isothermal luminescence decay curves have been measured from orthopaedic–standard ultra high molecular weight polyethylene between 35 and 70 ˚C on the rising edge of the main glow peak at 70 ˚C. Preparatory peak-shape analysis of the temperature-resolved glow peak at 70 ˚C measured at 1 ˚C s–1 gave a geometrical factor close to 0.5 suggestive of second order kinetics for both the isothermal and thermally stimulated luminescence. The results of analysis of the phosphorescence of transformed monotonic-to-peak isothermal decay curves are also second order, as is the conclusion from thermoluminescence glow-curve de-convolution. All methods of analysis give an activation energy of about 0.7 eV.
- Full Text:
- Date Issued: 2008
- Authors: Chithambo, Makaiko L
- Date: 2008
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125617 , vital:35801 , https://doi.10.1002/pssc.200776802
- Description: Isothermal luminescence decay curves have been measured from orthopaedic–standard ultra high molecular weight polyethylene between 35 and 70 ˚C on the rising edge of the main glow peak at 70 ˚C. Preparatory peak-shape analysis of the temperature-resolved glow peak at 70 ˚C measured at 1 ˚C s–1 gave a geometrical factor close to 0.5 suggestive of second order kinetics for both the isothermal and thermally stimulated luminescence. The results of analysis of the phosphorescence of transformed monotonic-to-peak isothermal decay curves are also second order, as is the conclusion from thermoluminescence glow-curve de-convolution. All methods of analysis give an activation energy of about 0.7 eV.
- Full Text:
- Date Issued: 2008
Photocatalytic oxidation of 1-hexene using GaPc and InPc octasubstituted derivatives
- Chauke, Vongani, Nyokong, Tebello
- Authors: Chauke, Vongani , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268611 , vital:54214 , xlink:href="https://doi.org/10.1016/j.molcata.2008.04.003"
- Description: Photocatalytic oxidation of 1-hexene by GaPc (1a–1c) and InPc (2a–2c) derivatives (Pc = phthalocyanine) is hereby presented. The derivatives studied are Pc octasubstituted with phenoxy (a), 4-tert-butylphenoxy (b) or benzyloxyphenoxy (c) at the peripheral positions. The photocatalytic oxidation products for 1-hexene were 1,2-epoxyhexane and 1-hexen-3-ol. The %conversion values of 1-hexene and %selectivity of 1,2-epoxyhexane were generally higher for InPc derivatives. Even though InPc derivatives showed better photocatalytic results than GaPc derivatives, the former were less stable relative to the latter. Both type I and type II mechanism were implicated in the photocatalysis mechanism.
- Full Text:
- Date Issued: 2008
- Authors: Chauke, Vongani , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268611 , vital:54214 , xlink:href="https://doi.org/10.1016/j.molcata.2008.04.003"
- Description: Photocatalytic oxidation of 1-hexene by GaPc (1a–1c) and InPc (2a–2c) derivatives (Pc = phthalocyanine) is hereby presented. The derivatives studied are Pc octasubstituted with phenoxy (a), 4-tert-butylphenoxy (b) or benzyloxyphenoxy (c) at the peripheral positions. The photocatalytic oxidation products for 1-hexene were 1,2-epoxyhexane and 1-hexen-3-ol. The %conversion values of 1-hexene and %selectivity of 1,2-epoxyhexane were generally higher for InPc derivatives. Even though InPc derivatives showed better photocatalytic results than GaPc derivatives, the former were less stable relative to the latter. Both type I and type II mechanism were implicated in the photocatalysis mechanism.
- Full Text:
- Date Issued: 2008
Photocatalytic transformation of 4-nitrophenol in aqueous media using suspended, water-insoluble metallophthalocyanine complexes
- Marais, Eloise, Antunes, Edith M, Nyokong, Tebello
- Authors: Marais, Eloise , Antunes, Edith M , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265986 , vital:53907 , xlink:href="https://doi.org/10.1080/00958970802146056"
- Description: Unsubstituted magnesium (MgPc), zinc (ZnPc) and chloroaluminium (ClAlPc) phthalocyanine complexes and the ring substituted zinc tetranitro (ZnPc(NO2)4), zinc tetraamino (ZnPc(NH2)4), zinc hexadecafluoro (ZnPcF16) and zinc hexadecachloro (ZnPcCl16), phthalocyanine complexes are employed as photocatalysts for the heterogeneous transformation of 4-nitrophenol (4-Np) to fumaric acid and 4-nitrocatechol. ClAlPc is the best catalyst, with 89 ± 8% degradation of 4-Np after 100 min. The least effective catalysts were ZnPcCl16 and MgPc.
- Full Text:
- Date Issued: 2008
- Authors: Marais, Eloise , Antunes, Edith M , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265986 , vital:53907 , xlink:href="https://doi.org/10.1080/00958970802146056"
- Description: Unsubstituted magnesium (MgPc), zinc (ZnPc) and chloroaluminium (ClAlPc) phthalocyanine complexes and the ring substituted zinc tetranitro (ZnPc(NO2)4), zinc tetraamino (ZnPc(NH2)4), zinc hexadecafluoro (ZnPcF16) and zinc hexadecachloro (ZnPcCl16), phthalocyanine complexes are employed as photocatalysts for the heterogeneous transformation of 4-nitrophenol (4-Np) to fumaric acid and 4-nitrocatechol. ClAlPc is the best catalyst, with 89 ± 8% degradation of 4-Np after 100 min. The least effective catalysts were ZnPcCl16 and MgPc.
- Full Text:
- Date Issued: 2008
Photoinduced energy transfer between water-soluble CdTe quantum dots and aluminium tetrasulfonated phthalocyanine
- Idowu, Mopelola, Chen, Ji-Yao, Nyokong, Tebello
- Authors: Idowu, Mopelola , Chen, Ji-Yao , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268564 , vital:54210 , xlink:href="https://doi.org/10.1039/B707808K"
- Description: Thiol stabilized CdTe quantum dots (QDs) synthesized in aqueous phase were used as energy donors to aluminium tetrasulfonated phthalocyanine (AlTSPc) through fluorescence resonance energy transfer (FRET). Energy transfer occurred from the QDs to AlTSPc upon photoexcitation of the QDs. An enhancement in efficiency of energy transfer with the nature of the carboxylic thiol stabilizers on the QDs was observed. The results showed that for enhanced FRET to occur, the donor–acceptor distance has to be lower than the critical distance. The quenching constant K as well as the binding constant kb values were calculated suggesting strong interaction of the QDs with the AlTSPc. Study of the photophysics of AlTSPc in the presence of the QDs revealed a high triplet state yield, hence the possibility of using QDs in combination with phthalocyanines as photosensitizers in photodynamic therapy. The triplet state lifetimes of AlTSPc in the presence of the QDs were calculated and the lifetime in the presence of CdTe capped with 3-mercaptopropionic acid (MPA) was found to be the longest. MPA capped QD in a mixture with AlTSPc resulted in long triplet lifetime and high triplet yield of the latter, and high energy transfer efficiency, hence was found to be most suitable as a potential candidate for photodynamic therapy of cancer studies.
- Full Text:
- Date Issued: 2008
- Authors: Idowu, Mopelola , Chen, Ji-Yao , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268564 , vital:54210 , xlink:href="https://doi.org/10.1039/B707808K"
- Description: Thiol stabilized CdTe quantum dots (QDs) synthesized in aqueous phase were used as energy donors to aluminium tetrasulfonated phthalocyanine (AlTSPc) through fluorescence resonance energy transfer (FRET). Energy transfer occurred from the QDs to AlTSPc upon photoexcitation of the QDs. An enhancement in efficiency of energy transfer with the nature of the carboxylic thiol stabilizers on the QDs was observed. The results showed that for enhanced FRET to occur, the donor–acceptor distance has to be lower than the critical distance. The quenching constant K as well as the binding constant kb values were calculated suggesting strong interaction of the QDs with the AlTSPc. Study of the photophysics of AlTSPc in the presence of the QDs revealed a high triplet state yield, hence the possibility of using QDs in combination with phthalocyanines as photosensitizers in photodynamic therapy. The triplet state lifetimes of AlTSPc in the presence of the QDs were calculated and the lifetime in the presence of CdTe capped with 3-mercaptopropionic acid (MPA) was found to be the longest. MPA capped QD in a mixture with AlTSPc resulted in long triplet lifetime and high triplet yield of the latter, and high energy transfer efficiency, hence was found to be most suitable as a potential candidate for photodynamic therapy of cancer studies.
- Full Text:
- Date Issued: 2008
Photophysical and photochemical properties of tetrasulfonated silicon and germanium phthalocyanine in aqueous and non-aqueous media
- Idowu, Mopolela, Nyokong, Tebello
- Authors: Idowu, Mopolela , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268624 , vital:54215 , xlink:href="https://doi.org/10.1016/j.jphotochem.2008.01.004"
- Description: The photophysical and photochemical properties of tetrasulfonated silicon and germanium phthalocyanine (SiPcS4 and GePcS4) in aqueous solution (phosphate-buffered saline (PBS) solution, pH 7.4) (in the presence and absence of cremophore EL (CEL)) and in dimethylsulphoxide (DMSO) were studied. The complexes have intense absorption in the visible/near-IR region though they highly aggregate in aqueous solution with a dimerization constant of ∼2 × 104 dm3 mol−1. The fluorescence excitation spectra however have only one band suggesting that only the monomer fluoresces. Both the quantum yields of the triplet state (ΦT) and the triplet lifetimes (τT) were found to be higher in DMSO compared to in aqueous solution. Aggregation is hindered by addition of cremophore EL in aqueous solution and this induced disaggregation caused an increased ΦT and τT probably due to the reduced interaction of the phthalocyanines with the aqueous medium in the presence of CEL.
- Full Text:
- Date Issued: 2008
- Authors: Idowu, Mopolela , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268624 , vital:54215 , xlink:href="https://doi.org/10.1016/j.jphotochem.2008.01.004"
- Description: The photophysical and photochemical properties of tetrasulfonated silicon and germanium phthalocyanine (SiPcS4 and GePcS4) in aqueous solution (phosphate-buffered saline (PBS) solution, pH 7.4) (in the presence and absence of cremophore EL (CEL)) and in dimethylsulphoxide (DMSO) were studied. The complexes have intense absorption in the visible/near-IR region though they highly aggregate in aqueous solution with a dimerization constant of ∼2 × 104 dm3 mol−1. The fluorescence excitation spectra however have only one band suggesting that only the monomer fluoresces. Both the quantum yields of the triplet state (ΦT) and the triplet lifetimes (τT) were found to be higher in DMSO compared to in aqueous solution. Aggregation is hindered by addition of cremophore EL in aqueous solution and this induced disaggregation caused an increased ΦT and τT probably due to the reduced interaction of the phthalocyanines with the aqueous medium in the presence of CEL.
- Full Text:
- Date Issued: 2008
Photosensitizing properties of octacarboxy metallophthalocyanines in aqueous medium and their interaction with bovine serum albumin
- Idowu, Mopelola, Nyokong, Tebello
- Authors: Idowu, Mopelola , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/264552 , vital:53744 , xlink:href="https://doi.org/10.1016/j.jphotochem.2008.09.003"
- Description: Photosensitizing properties of aluminium, silicon, zinc and germanium octacarboxy phthalocyanines ((OH)AlOCPc, (OH)2SiOCPc, ZnOCPc and (OH)2GeOCPc) were studied in aqueous medium and in the presence of bovine serum albumin (BSA). Triplet quantum yields increased with increasing atomic number of the central metals of the metallophthalocyanine. The efficiency of singlet oxygen generation via energy transfer from the excited triplet state of the octacarboxy metallophthalocyanines (MOCPcs) to ground state oxygen increased markedly in the presence of BSA. The triplet state lifetimes of the MOCPc complexes in the presence of BSA were found to be longer than in the absence of BSA, ranging from 110 to 580 μs. These complexes bind readily to BSA. Stern–Volmer quenching constant KSV as well as the binding constant kb values were calculated. The probable mechanism of quenching of BSA fluorescence by the MOCPc complexes is by static quenching.
- Full Text:
- Date Issued: 2008
- Authors: Idowu, Mopelola , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/264552 , vital:53744 , xlink:href="https://doi.org/10.1016/j.jphotochem.2008.09.003"
- Description: Photosensitizing properties of aluminium, silicon, zinc and germanium octacarboxy phthalocyanines ((OH)AlOCPc, (OH)2SiOCPc, ZnOCPc and (OH)2GeOCPc) were studied in aqueous medium and in the presence of bovine serum albumin (BSA). Triplet quantum yields increased with increasing atomic number of the central metals of the metallophthalocyanine. The efficiency of singlet oxygen generation via energy transfer from the excited triplet state of the octacarboxy metallophthalocyanines (MOCPcs) to ground state oxygen increased markedly in the presence of BSA. The triplet state lifetimes of the MOCPc complexes in the presence of BSA were found to be longer than in the absence of BSA, ranging from 110 to 580 μs. These complexes bind readily to BSA. Stern–Volmer quenching constant KSV as well as the binding constant kb values were calculated. The probable mechanism of quenching of BSA fluorescence by the MOCPc complexes is by static quenching.
- Full Text:
- Date Issued: 2008
Pragmatic research design
- Amos, Trevor L, Pearse, Noel J
- Authors: Amos, Trevor L , Pearse, Noel J
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/270943 , vital:54494 , xlink:href="https://academic-publishing.org/index.php/ejbrm/article/view/1230/1193"
- Description: The creation of wealth is an important issue in any society, and entrepreneurship is regarded as an important catalyst in the creation of new wealth. This presents a challenge to develop entrepreneurship successfully. An important site for the development of entrepreneurship is higher education. The challenge however, is that there is a lack of a general understanding on how to educate students for entrepreneurship. In addition, current thought and practice on entrepreneurship education is historically biased, implying that graduates are essentially prepared for the past instead of for the future. From the perspective of higher education, the problem is how to develop current students to be entrepreneurial in the future. What is needed is to project into the future and then to develop an understanding of what should be taught as well as how it should be taught today. A versatile research technique that can assist in achieving this objective is the Delphi technique, as it is used to conduct futures research or research into areas where knowledge is incomplete. The Delphi method is a type of group interview, using the collective opinion of knowledgeable experts. The technique makes use of several rounds of data collection and feedback to create a consensus of opinion. Making use of the Delphi technique, research is being designed that will formulate expert‑based strategic guidelines on entrepreneurial education within the South African higher education sector. The aim of this paper is to illustrate the research design considerations that arise in the use of the Delphi technique for this purpose and how they are addressed. The main characteristics of the Delphi are presented and arguments for the use of the Delphi within a constructivist paradigm are discussed. Practical issues related to the design of the Delphi, panel‑member selection, and the formulation of panel questions, are examined. In illustrating these design considerations, the paper demonstrates a pragmatic approach to research design as well as the importance of creating coherence between the research question, the research paradigm, the research method and its use, encouraging research practitioners to adopt a more systematic, deliberate and philosophically‑based approach to research design.
- Full Text:
- Date Issued: 2008
- Authors: Amos, Trevor L , Pearse, Noel J
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/270943 , vital:54494 , xlink:href="https://academic-publishing.org/index.php/ejbrm/article/view/1230/1193"
- Description: The creation of wealth is an important issue in any society, and entrepreneurship is regarded as an important catalyst in the creation of new wealth. This presents a challenge to develop entrepreneurship successfully. An important site for the development of entrepreneurship is higher education. The challenge however, is that there is a lack of a general understanding on how to educate students for entrepreneurship. In addition, current thought and practice on entrepreneurship education is historically biased, implying that graduates are essentially prepared for the past instead of for the future. From the perspective of higher education, the problem is how to develop current students to be entrepreneurial in the future. What is needed is to project into the future and then to develop an understanding of what should be taught as well as how it should be taught today. A versatile research technique that can assist in achieving this objective is the Delphi technique, as it is used to conduct futures research or research into areas where knowledge is incomplete. The Delphi method is a type of group interview, using the collective opinion of knowledgeable experts. The technique makes use of several rounds of data collection and feedback to create a consensus of opinion. Making use of the Delphi technique, research is being designed that will formulate expert‑based strategic guidelines on entrepreneurial education within the South African higher education sector. The aim of this paper is to illustrate the research design considerations that arise in the use of the Delphi technique for this purpose and how they are addressed. The main characteristics of the Delphi are presented and arguments for the use of the Delphi within a constructivist paradigm are discussed. Practical issues related to the design of the Delphi, panel‑member selection, and the formulation of panel questions, are examined. In illustrating these design considerations, the paper demonstrates a pragmatic approach to research design as well as the importance of creating coherence between the research question, the research paradigm, the research method and its use, encouraging research practitioners to adopt a more systematic, deliberate and philosophically‑based approach to research design.
- Full Text:
- Date Issued: 2008
Prototyping a p2p sip user agent with support for multiple overlays
- Tsietsi, Mosiuoa, Terzoli, Alfredo, Wells, George C
- Authors: Tsietsi, Mosiuoa , Terzoli, Alfredo , Wells, George C
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430858 , vital:72722 , 10.1109/PERCOM.2008.102
- Description: This paper describes a systematic approach to provide support at the user agent level for peer-to-peer based multimedia communications us-ing SIP (session initiation protocol). In a society that is becoming in-creasingly mobile, the advantages of engaging in interactive sessions without relying on central servers or infrastructure are clear. Yet, cur-rently many user agents and devices have little support for peer-to-peer communications. In this paper, we motivate for the use of structured peer-to-peer protocols called DHTs, as a foundation for a peer-to-peer layer. We introduce the concept of "DHTplug-ins" which assist in ab-stracting the interface between the higher level application and the pro-prietary APIs exposed by the underlying DHTs, allowing us to manipu-late user agents with peer-to-peer logic. This embeddable-DHT concept allows these user agents to use different DHTs with one common inter-face and participate in multiple overlays. We show how an open source SIP user agent was thus modified and how realtime communications were supported.
- Full Text:
- Date Issued: 2008
- Authors: Tsietsi, Mosiuoa , Terzoli, Alfredo , Wells, George C
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430858 , vital:72722 , 10.1109/PERCOM.2008.102
- Description: This paper describes a systematic approach to provide support at the user agent level for peer-to-peer based multimedia communications us-ing SIP (session initiation protocol). In a society that is becoming in-creasingly mobile, the advantages of engaging in interactive sessions without relying on central servers or infrastructure are clear. Yet, cur-rently many user agents and devices have little support for peer-to-peer communications. In this paper, we motivate for the use of structured peer-to-peer protocols called DHTs, as a foundation for a peer-to-peer layer. We introduce the concept of "DHTplug-ins" which assist in ab-stracting the interface between the higher level application and the pro-prietary APIs exposed by the underlying DHTs, allowing us to manipu-late user agents with peer-to-peer logic. This embeddable-DHT concept allows these user agents to use different DHTs with one common inter-face and participate in multiple overlays. We show how an open source SIP user agent was thus modified and how realtime communications were supported.
- Full Text:
- Date Issued: 2008
Reading Conference recommendations in a wider context of social change
- Authors: Lotz-Sisitka, Heila
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373792 , vital:66723 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122783"
- Description: This short Viewpoint paper considers the role and value of conference recommendations in shaping the field of environmental education. It explores the social politics, and often contested nature, of conference recommendations and their institutional histories, arguing that the act of producing conference recommendations forms part of the practices of new social movements. The paper recommends historicising conference recommendations and OEcross readings‚ to consider changing discourses and new developments in the field. Accompanying the short Viewpoint paper, are two sets of recently produced conference recommendations, one from the 4th International Environmental Education Conference held in Ahmedabad, India, and the other from the 1st International Conference on Mainstreaming Environment and Sustainability in African Universities held in Nairobi, Kenya.
- Full Text:
- Date Issued: 2008
- Authors: Lotz-Sisitka, Heila
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373792 , vital:66723 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122783"
- Description: This short Viewpoint paper considers the role and value of conference recommendations in shaping the field of environmental education. It explores the social politics, and often contested nature, of conference recommendations and their institutional histories, arguing that the act of producing conference recommendations forms part of the practices of new social movements. The paper recommends historicising conference recommendations and OEcross readings‚ to consider changing discourses and new developments in the field. Accompanying the short Viewpoint paper, are two sets of recently produced conference recommendations, one from the 4th International Environmental Education Conference held in Ahmedabad, India, and the other from the 1st International Conference on Mainstreaming Environment and Sustainability in African Universities held in Nairobi, Kenya.
- Full Text:
- Date Issued: 2008