Hydrogen peroxide oxidation of 2-chlorophenol and 2, 4, 5-trichlorophenol catalyzed by monomeric and aggregated cobalt tetrasulfophthalocyanine
- Agboola, Bolade, Ozoemena, Kenneth I, Nyokong, Tebello
- Authors: Agboola, Bolade , Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289249 , vital:56612 , xlink:href="https://doi.org/10.1016/j.molcata.2004.10.041"
- Description: Cobalt tetrasulfophthalocyanine (CoTSPc) was used to catalyze the oxidation of 2-chlorophenol (2-CP) and 2,4,5-trichlorophenol (TCP) using hydrogen peroxide (H2O2) as the oxidant. This CoTSPc catalyzed hydrogen peroxide oxidation of chlorophenols resulted in the formation of different types of oxidation products depending on the solvent conditions. In water/methanol conditions (where CoTSPc is mainly monomeric, and unionized forms of the phenols), phenol and hydroquinone were the main oxidation products, while in phosphate buffer solutions (pH 7 and 10 for TCP and 2-CP, respectively, where CoTSPc is mainly aggregated, and ionized forms of the phenols), benzoquinone was the main product. In contrast to CoTSPc, other MTSPc complexes studied (AlTSPc, CuTSPc and NiTSPc) exhibited no detectable catalytic effect on the oxidation of chlorophenols under the experimental conditions employed, thus proving the effect of the central metal ions on efficient catalysis of chlorophenol. Reaction pathways are proposed based on the relative time of oxidation products formation.
- Full Text:
- Date Issued: 2005
- Authors: Agboola, Bolade , Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289249 , vital:56612 , xlink:href="https://doi.org/10.1016/j.molcata.2004.10.041"
- Description: Cobalt tetrasulfophthalocyanine (CoTSPc) was used to catalyze the oxidation of 2-chlorophenol (2-CP) and 2,4,5-trichlorophenol (TCP) using hydrogen peroxide (H2O2) as the oxidant. This CoTSPc catalyzed hydrogen peroxide oxidation of chlorophenols resulted in the formation of different types of oxidation products depending on the solvent conditions. In water/methanol conditions (where CoTSPc is mainly monomeric, and unionized forms of the phenols), phenol and hydroquinone were the main oxidation products, while in phosphate buffer solutions (pH 7 and 10 for TCP and 2-CP, respectively, where CoTSPc is mainly aggregated, and ionized forms of the phenols), benzoquinone was the main product. In contrast to CoTSPc, other MTSPc complexes studied (AlTSPc, CuTSPc and NiTSPc) exhibited no detectable catalytic effect on the oxidation of chlorophenols under the experimental conditions employed, thus proving the effect of the central metal ions on efficient catalysis of chlorophenol. Reaction pathways are proposed based on the relative time of oxidation products formation.
- Full Text:
- Date Issued: 2005
Towards an economic valuation of biodiversity: freshwater ecosystems
- Antrobus, Geoffrey G, Law, Matt
- Authors: Antrobus, Geoffrey G , Law, Matt
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143013 , vital:38185 , http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.620.4217andrep=rep1andtype=pdf
- Description: The valuation of environmental resources and biodiversity as a whole has become an increasingly necessary topic of research as our understanding of the importance and benefits of the healthy functioning of the environment develops. A major shortcoming of current research is that there has been very little advance in the valuation of freshwater biodiversity. The paper examines the socioeconomic importance of biodiversity and outlines the fundamentals of economic valuation thereof. The difficulties associated with the valuation of freshwater ecosystems are outlined and the results of a study presented to the South African Water Research Commission incorporating resource economics into freshwater quality objectives is described. The valuation of freshwater biodiversity is an important and complicated task that needs close attention in future research.
- Full Text:
- Date Issued: 2005
- Authors: Antrobus, Geoffrey G , Law, Matt
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143013 , vital:38185 , http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.620.4217andrep=rep1andtype=pdf
- Description: The valuation of environmental resources and biodiversity as a whole has become an increasingly necessary topic of research as our understanding of the importance and benefits of the healthy functioning of the environment develops. A major shortcoming of current research is that there has been very little advance in the valuation of freshwater biodiversity. The paper examines the socioeconomic importance of biodiversity and outlines the fundamentals of economic valuation thereof. The difficulties associated with the valuation of freshwater ecosystems are outlined and the results of a study presented to the South African Water Research Commission incorporating resource economics into freshwater quality objectives is described. The valuation of freshwater biodiversity is an important and complicated task that needs close attention in future research.
- Full Text:
- Date Issued: 2005
The effect of structure on the electrochemical properties of 14 marine pyrroloquinoline metabolites
- Antunes, Edith M, Maree, Suzanne E, Nyokong, Tebello, Davies-Coleman, Mike T, Maree, M David
- Authors: Antunes, Edith M , Maree, Suzanne E , Nyokong, Tebello , Davies-Coleman, Mike T , Maree, M David
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286126 , vital:56242 , xlink:href="https://doi.org/10.3184/030823405775146915"
- Description: The electrochemical properties of 14 structurally related pyrroloquinoline metabolites (compounds 1–14) isolated from marine sponges were studied in pH-varied experiments using cyclic and square wave voltammetry. In general both substitution patterns and pH were observed to influence the reduction potentials of these molecules.
- Full Text:
- Date Issued: 2005
- Authors: Antunes, Edith M , Maree, Suzanne E , Nyokong, Tebello , Davies-Coleman, Mike T , Maree, M David
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286126 , vital:56242 , xlink:href="https://doi.org/10.3184/030823405775146915"
- Description: The electrochemical properties of 14 structurally related pyrroloquinoline metabolites (compounds 1–14) isolated from marine sponges were studied in pH-varied experiments using cyclic and square wave voltammetry. In general both substitution patterns and pH were observed to influence the reduction potentials of these molecules.
- Full Text:
- Date Issued: 2005
Harnessing newsroom knowledge:
- Authors: Berger, Guy
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159244 , vital:40280 , https://hdl.handle.net/10520/EJC146387
- Description: Nairobi's Nation newspaper has a sophisticated content management system (CMS); Grahamstown's Grocott's Mail has a patchwork of paper and computer tech. In Harare, the Mirror and the Independent newspapers fall somewhere in between. But what all of them lack is a way to use information communication technologies for knowledge management.
- Full Text:
- Date Issued: 2005
- Authors: Berger, Guy
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159244 , vital:40280 , https://hdl.handle.net/10520/EJC146387
- Description: Nairobi's Nation newspaper has a sophisticated content management system (CMS); Grahamstown's Grocott's Mail has a patchwork of paper and computer tech. In Harare, the Mirror and the Independent newspapers fall somewhere in between. But what all of them lack is a way to use information communication technologies for knowledge management.
- Full Text:
- Date Issued: 2005
"The French Imperial Nation-State":
- Authors: Bischoff, Paul, 1954-
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161376 , vital:40621
- Description: Book Review. The French Imperial Nation-State. By G Wilder (2005).
- Full Text:
- Date Issued: 2005
- Authors: Bischoff, Paul, 1954-
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161376 , vital:40621
- Description: Book Review. The French Imperial Nation-State. By G Wilder (2005).
- Full Text:
- Date Issued: 2005
The reflection on peace agreements in Africa: feature
- Authors: Bischoff, Paul, 1954-
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161398 , vital:40623
- Description: For Africa, the advent of globalisation, delivered in the shape of Structural Adjustment Programmes in the period from the early 1980s, ushered in the beginning of the end of the nation-building framework adopted at independence. Government's withdrawal from social, intellectual and economic areas of life brought into sharp relief the vulnerability of both state and society. Accompanied on the foreign policy front by a loss of Big Power protection after the Cold War ended, 'low and intrastate politics' came to the fore.
- Full Text:
- Date Issued: 2005
- Authors: Bischoff, Paul, 1954-
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161398 , vital:40623
- Description: For Africa, the advent of globalisation, delivered in the shape of Structural Adjustment Programmes in the period from the early 1980s, ushered in the beginning of the end of the nation-building framework adopted at independence. Government's withdrawal from social, intellectual and economic areas of life brought into sharp relief the vulnerability of both state and society. Accompanied on the foreign policy front by a loss of Big Power protection after the Cold War ended, 'low and intrastate politics' came to the fore.
- Full Text:
- Date Issued: 2005
Marine Reserves: a guide to science, design, and use
- Authors: Booth, Anthony J
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124965 , vital:35714 , https://doi.10.2989/16085910509503862
- Description: With the considerable pressures that are being placed on our marine resources, there is an urgent need to find alternative strategies to ensure their long-term sustainability. One measure that has been proposed, and which is rapidly gaining popularity, is the designation of Marine Protected Area (MPA). These are demarcated areas that prohibit (or at least restrict) consumptive or extractive uses, such that human interferences and impacts are minimised. In this edited collection of papers, most of which have been written or co-written by the authors themselves, Sobel and Dahlgren have presented an excellent synopsis of the rationale behind, and the scientific basis underpinning, the use of marine reserves as a management tool. In addition, they have devoted half the book to the provision of case studies.
- Full Text:
- Date Issued: 2005
- Authors: Booth, Anthony J
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124965 , vital:35714 , https://doi.10.2989/16085910509503862
- Description: With the considerable pressures that are being placed on our marine resources, there is an urgent need to find alternative strategies to ensure their long-term sustainability. One measure that has been proposed, and which is rapidly gaining popularity, is the designation of Marine Protected Area (MPA). These are demarcated areas that prohibit (or at least restrict) consumptive or extractive uses, such that human interferences and impacts are minimised. In this edited collection of papers, most of which have been written or co-written by the authors themselves, Sobel and Dahlgren have presented an excellent synopsis of the rationale behind, and the scientific basis underpinning, the use of marine reserves as a management tool. In addition, they have devoted half the book to the provision of case studies.
- Full Text:
- Date Issued: 2005
Imbhola yesiXhosa traditional Xhosa cosmetics:
- Cocks, Michelle L, Dold, Anthony P
- Authors: Cocks, Michelle L , Dold, Anthony P
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141370 , vital:37966 , http://pza.sanbi.org/sites/default/files/info_library/imbhola_yesixhosa_pdf.pdf
- Description: Plants have been used for cosmetic purposes since time immemorial. The earliest known cosmetics come from the First Dynasty of Egypt, about 3100-2907 BC. Since the ancient Egyptians who used olive oil perfumed with aromatic plants to keep their skin supple, humans have been using plant extracts for cleansing and beautifying purposes.
- Full Text:
- Date Issued: 2005
- Authors: Cocks, Michelle L , Dold, Anthony P
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141370 , vital:37966 , http://pza.sanbi.org/sites/default/files/info_library/imbhola_yesixhosa_pdf.pdf
- Description: Plants have been used for cosmetic purposes since time immemorial. The earliest known cosmetics come from the First Dynasty of Egypt, about 3100-2907 BC. Since the ancient Egyptians who used olive oil perfumed with aromatic plants to keep their skin supple, humans have been using plant extracts for cleansing and beautifying purposes.
- Full Text:
- Date Issued: 2005
Monetary valuation of livelihoods for understanding the composition and complexity of rural households
- Dovie, Delali B K, Witkowski, Ed T F, Shackleton, Charlie M
- Authors: Dovie, Delali B K , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181346 , vital:43721 , xlink:href="https://doi.org/10.1007/s10460-004-7233-0"
- Description: There is, at present, little precise understanding of the relative contributions of the various income streams used by impoverished rural households in southern Africa. The impact of household profiles on overall income also is not well understood. There is, therefore, little consideration of these factors in national economic accounting. This paper is an attempt to reduce this gap in knowledge by reflecting on the relative contribution of agro-pastoralism, secondary woodland resources, and formal and informal cash income streams to households in the semi-arid rural village of Thorndale, Limpopo Province, South Africa. In the absence of jobs and confronted with high migrant labor, households with open access to natural resources derived more benefits from land-based livelihoods than cash income streams (i.e., 57.5 % vs. 42.5 %). Total livelihood income was valued at US$2887 per household per annum. A significant correlation between monetary values derived from crops and formal wages was established, and it was found that households with high cash incomes tended to invest more in crop production. Over 80 of households were male-headed. Of these heads of household, more than 60 were long-term migrants to urban areas, leaving household decision-making to the women. The low literacy rates of women have deprived them of paid jobs outside the area and, therefore, have increased their dependence on crops (62%) and secondary woodlands resources (60%). This was further reflected in the proportion of households in which females were the main contributors of cash income (9.7%), or joint contributors with men (24.4%). Various positive correlations were established between the number of women per household and the three land-based livelihoods. This implied that women’s total control over such activities was mostly a result of the absence of men and not a typical phenomenon. In spite of this control, it was not positively reflected in the lives of majority of the women. Households differed in their participation in livelihood activities. Household size influenced the level of production and was positively correlated with the value of secondary woodland resources and crops. The study shows the interdependence of land-based livelihood sources and the impact of household features on production and consumption. Policies that focus on livelihood options need to recognize and accommodate associated household dynamics.
- Full Text:
- Date Issued: 2005
- Authors: Dovie, Delali B K , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181346 , vital:43721 , xlink:href="https://doi.org/10.1007/s10460-004-7233-0"
- Description: There is, at present, little precise understanding of the relative contributions of the various income streams used by impoverished rural households in southern Africa. The impact of household profiles on overall income also is not well understood. There is, therefore, little consideration of these factors in national economic accounting. This paper is an attempt to reduce this gap in knowledge by reflecting on the relative contribution of agro-pastoralism, secondary woodland resources, and formal and informal cash income streams to households in the semi-arid rural village of Thorndale, Limpopo Province, South Africa. In the absence of jobs and confronted with high migrant labor, households with open access to natural resources derived more benefits from land-based livelihoods than cash income streams (i.e., 57.5 % vs. 42.5 %). Total livelihood income was valued at US$2887 per household per annum. A significant correlation between monetary values derived from crops and formal wages was established, and it was found that households with high cash incomes tended to invest more in crop production. Over 80 of households were male-headed. Of these heads of household, more than 60 were long-term migrants to urban areas, leaving household decision-making to the women. The low literacy rates of women have deprived them of paid jobs outside the area and, therefore, have increased their dependence on crops (62%) and secondary woodlands resources (60%). This was further reflected in the proportion of households in which females were the main contributors of cash income (9.7%), or joint contributors with men (24.4%). Various positive correlations were established between the number of women per household and the three land-based livelihoods. This implied that women’s total control over such activities was mostly a result of the absence of men and not a typical phenomenon. In spite of this control, it was not positively reflected in the lives of majority of the women. Households differed in their participation in livelihood activities. Household size influenced the level of production and was positively correlated with the value of secondary woodland resources and crops. The study shows the interdependence of land-based livelihood sources and the impact of household features on production and consumption. Policies that focus on livelihood options need to recognize and accommodate associated household dynamics.
- Full Text:
- Date Issued: 2005
Modelling the sustainable harvest of Sclerocarya birrea subsp. caffra fruits in the South African lowveld
- Emanuel, P L, Shackleton, Charlie M, Baxter, Jeremy
- Authors: Emanuel, P L , Shackleton, Charlie M , Baxter, Jeremy
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181312 , vital:43718 , xlink:href="https://doi.org/10.1016/j.foreco.2005.03.066"
- Description: Levels of commercialization, size class profile and fruit production of Sclerocarya birrea (marula) trees were studied in the Bushbuckridge region of South Africa. A stage-based population matrix model was used to estimate the sustainable yield for S. birrea fruit. The trees begin to bear fruit at an average size of 42.8 cm in circumference and this relates to an approximate age of 19 years. For a stable size class profile, the population growth rate, λ, was 1.1828758. The observed size class profile did not conform to the stable stage size class profile, obtained from the model. Thus, it was not possible to predict the state of the observed population. Using the model, it was estimated that 92% of fruit could be removed without impacting the current population profile. The management of other more destructive forms of S. birrea resource use (such as bark or firewood harvesting), however, do need to be monitored to limit negative impacts on the population that may reduce fruit availability for regeneration or cropping.
- Full Text:
- Date Issued: 2005
- Authors: Emanuel, P L , Shackleton, Charlie M , Baxter, Jeremy
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181312 , vital:43718 , xlink:href="https://doi.org/10.1016/j.foreco.2005.03.066"
- Description: Levels of commercialization, size class profile and fruit production of Sclerocarya birrea (marula) trees were studied in the Bushbuckridge region of South Africa. A stage-based population matrix model was used to estimate the sustainable yield for S. birrea fruit. The trees begin to bear fruit at an average size of 42.8 cm in circumference and this relates to an approximate age of 19 years. For a stable size class profile, the population growth rate, λ, was 1.1828758. The observed size class profile did not conform to the stable stage size class profile, obtained from the model. Thus, it was not possible to predict the state of the observed population. Using the model, it was estimated that 92% of fruit could be removed without impacting the current population profile. The management of other more destructive forms of S. birrea resource use (such as bark or firewood harvesting), however, do need to be monitored to limit negative impacts on the population that may reduce fruit availability for regeneration or cropping.
- Full Text:
- Date Issued: 2005
The Dassie and the Hunter: A South African Meeting
- Authors: Kaschula, Russell H
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175147 , vital:42547 , https://doi.org/10.4314/tvl.v43i1.29727
- Description: This book does not resemble any of Jeff Opland’s previous academic works. There is no similarity in style, and to some extent content. His previous books, namely, Xhosa oral poetry: Aspects of a black South African tradition (Cambridge University Press, 1983), and Xhosa poets and poetry (David Philip, 1998), were written as purely scientific, academic works. The Dassie and the Hunter amounts to a subtle snub of academia and its restrictive rules. Though written by Opland, it is as if he and his research subject, Manisi, have colluded to make this work different and special, in a personal mystical way, disregarding academic etiquette, weaving a more creative, poetic tapestry. This makes the book an interesting read. In style and content, it is neither rigorously academic, solely biographical, nor purely creative. It evades classification. It is individualistic.
- Full Text:
- Date Issued: 2005
- Authors: Kaschula, Russell H
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175147 , vital:42547 , https://doi.org/10.4314/tvl.v43i1.29727
- Description: This book does not resemble any of Jeff Opland’s previous academic works. There is no similarity in style, and to some extent content. His previous books, namely, Xhosa oral poetry: Aspects of a black South African tradition (Cambridge University Press, 1983), and Xhosa poets and poetry (David Philip, 1998), were written as purely scientific, academic works. The Dassie and the Hunter amounts to a subtle snub of academia and its restrictive rules. Though written by Opland, it is as if he and his research subject, Manisi, have colluded to make this work different and special, in a personal mystical way, disregarding academic etiquette, weaving a more creative, poetic tapestry. This makes the book an interesting read. In style and content, it is neither rigorously academic, solely biographical, nor purely creative. It evades classification. It is individualistic.
- Full Text:
- Date Issued: 2005
The symbiosis between capitalists:
- Authors: Kyazze, Simwogerere
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159211 , vital:40277 , https://hdl.handle.net/10520/EJC146362
- Description: Question: Who is the most famous writer of the New Millennium? Answer: JK Rowling, author of the Harry Potter stories. If you answered in the affirmative, you will be forgiven for sharing the view of many teenagers (and an increasing number of young adults) around the world who swear by Mr Potter's benign witchcraft. But while we ponder the Harry Potter juggernaut (Ms Rowling's books are bestsellers in any language), let us also ponder why very few serious intellectuals make it to the top of the world's most famous best-seller lists (The New York Times, Amazon.com, Times of London, etc). There is a reason why Gore Vidal, Jeffery Sachs, Noam Chomsky and Edward Said, have all had some of their best work published by little known outfits such as St Mark's Publishing House, and not celebrated imprints of the Simon and Schuster or Alfred Knopf calibre.
- Full Text:
- Date Issued: 2005
- Authors: Kyazze, Simwogerere
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159211 , vital:40277 , https://hdl.handle.net/10520/EJC146362
- Description: Question: Who is the most famous writer of the New Millennium? Answer: JK Rowling, author of the Harry Potter stories. If you answered in the affirmative, you will be forgiven for sharing the view of many teenagers (and an increasing number of young adults) around the world who swear by Mr Potter's benign witchcraft. But while we ponder the Harry Potter juggernaut (Ms Rowling's books are bestsellers in any language), let us also ponder why very few serious intellectuals make it to the top of the world's most famous best-seller lists (The New York Times, Amazon.com, Times of London, etc). There is a reason why Gore Vidal, Jeffery Sachs, Noam Chomsky and Edward Said, have all had some of their best work published by little known outfits such as St Mark's Publishing House, and not celebrated imprints of the Simon and Schuster or Alfred Knopf calibre.
- Full Text:
- Date Issued: 2005
Agroforestry tree products (AFTPs): Targeting poverty reduction and enhanced livelihoods
- Leakey, Roger R, Tchoundjeu, Zac, Schreckenberg, Kate, Shackleton, Sheona E, Shackleton, Charlie M
- Authors: Leakey, Roger R , Tchoundjeu, Zac , Schreckenberg, Kate , Shackleton, Sheona E , Shackleton, Charlie M
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182136 , vital:43803 , xlink:href="https://doi.org/10.1080/14735903.2005.9684741"
- Description: Agroforestry tree domestication emerged as a farmer-driven, market-led process in the early 1990s and became an international initiative. A participatory approach now supplements the more traditional aspects of tree improvement, and is seen as an important strategy towards the Millennium Development Goals of eradicating poverty and hunger, promoting social equity and environmental sustainability. Considerable progress has been made towards the domestication of indigenous fruits and nuts in many villages in Cameroon and Nigeria. Vegetatively-propagated cultivars based on a sound knowledge of ‘ideotypes’ derived from an understanding of the tree-to-tree variation in many commercially important traits are being developed by farmers. These are being integrated into polycultural farming systems, especially the cocoa agroforests. Markets for Agroforestry Tree Products (AFTPs) are crucial for the adoption of agroforestry on a scale to have meaningful economic, social and environmental impacts. Important lessons have been learned in southern Africa from detailed studies of the commercialization of AFTPs. These provide support for the wider acceptance of the role of domesticating indigenous trees in the promotion of enhanced livelihoods for poor farmers in the tropics. Policy guidelines have been developed in support of this sustainable rural development as an alternative strategy to those proposed in many other major development and conservation fora.
- Full Text:
- Date Issued: 2005
- Authors: Leakey, Roger R , Tchoundjeu, Zac , Schreckenberg, Kate , Shackleton, Sheona E , Shackleton, Charlie M
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182136 , vital:43803 , xlink:href="https://doi.org/10.1080/14735903.2005.9684741"
- Description: Agroforestry tree domestication emerged as a farmer-driven, market-led process in the early 1990s and became an international initiative. A participatory approach now supplements the more traditional aspects of tree improvement, and is seen as an important strategy towards the Millennium Development Goals of eradicating poverty and hunger, promoting social equity and environmental sustainability. Considerable progress has been made towards the domestication of indigenous fruits and nuts in many villages in Cameroon and Nigeria. Vegetatively-propagated cultivars based on a sound knowledge of ‘ideotypes’ derived from an understanding of the tree-to-tree variation in many commercially important traits are being developed by farmers. These are being integrated into polycultural farming systems, especially the cocoa agroforests. Markets for Agroforestry Tree Products (AFTPs) are crucial for the adoption of agroforestry on a scale to have meaningful economic, social and environmental impacts. Important lessons have been learned in southern Africa from detailed studies of the commercialization of AFTPs. These provide support for the wider acceptance of the role of domesticating indigenous trees in the promotion of enhanced livelihoods for poor farmers in the tropics. Policy guidelines have been developed in support of this sustainable rural development as an alternative strategy to those proposed in many other major development and conservation fora.
- Full Text:
- Date Issued: 2005
Methodological Decisions in Context: The dilemmas and challenges of novice African scholars
- Lupele, Justin, Mwingi, Mweru, Kinyanjui, Felistus, Kimani, Joyce, Kisamba, Christine
- Authors: Lupele, Justin , Mwingi, Mweru , Kinyanjui, Felistus , Kimani, Joyce , Kisamba, Christine
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373734 , vital:66717 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122698"
- Description: This paper emerges out of a panel discussion during a PhD week and subsequent 8th International Environmental Education Invitation Seminar held at Rhodes University in 2004 and 2005 respectively. It illuminates some insights into our struggles (as novice African researchers) in trying to respond to contextual realities as we research education and social change in African contexts, seeking insight into what counts as legitimate research in this context. The paper considers our struggles at conceptual, methodological, analytical and data generation levels, and in a politics of research. This is done by means of examples drawn from five current doctoral research projects being undertaken in east and southern African regions, using a review framework that represents fairly common dimensions of PhD research. We conclude that research, when defined rigidly within research disciplines/paradigms (as have been defined in some – primarily Western – research trajectories) may fail to take into account African social and contextual realities when applied uncritically. We argue that there is need for researchers in Africa to consider a multiplicity of approaches if research is to be meaningful in, and responsive to, social and contextual realities. In particular, we argue for taking account of socio historical and socio-cultural contexts in creating African epistemology in and through research.
- Full Text:
- Date Issued: 2005
- Authors: Lupele, Justin , Mwingi, Mweru , Kinyanjui, Felistus , Kimani, Joyce , Kisamba, Christine
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373734 , vital:66717 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122698"
- Description: This paper emerges out of a panel discussion during a PhD week and subsequent 8th International Environmental Education Invitation Seminar held at Rhodes University in 2004 and 2005 respectively. It illuminates some insights into our struggles (as novice African researchers) in trying to respond to contextual realities as we research education and social change in African contexts, seeking insight into what counts as legitimate research in this context. The paper considers our struggles at conceptual, methodological, analytical and data generation levels, and in a politics of research. This is done by means of examples drawn from five current doctoral research projects being undertaken in east and southern African regions, using a review framework that represents fairly common dimensions of PhD research. We conclude that research, when defined rigidly within research disciplines/paradigms (as have been defined in some – primarily Western – research trajectories) may fail to take into account African social and contextual realities when applied uncritically. We argue that there is need for researchers in Africa to consider a multiplicity of approaches if research is to be meaningful in, and responsive to, social and contextual realities. In particular, we argue for taking account of socio historical and socio-cultural contexts in creating African epistemology in and through research.
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- Date Issued: 2005
Melatonin generates singlet oxygen on laser irradiation but acts as a quencher when irradiated by lamp photolysis
- Maharaj, Deepa S, Molell, H, Antunes, Edith M, Maharaj, Hiren, Maree, D M, Nyokong, Tebello, Glass, Beverley D, Daya, Santy
- Authors: Maharaj, Deepa S , Molell, H , Antunes, Edith M , Maharaj, Hiren , Maree, D M , Nyokong, Tebello , Glass, Beverley D , Daya, Santy
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300335 , vital:57917 , xlink:href="https://doi.org/10.1111/j.1600-079X.2004.00185.x"
- Description: Melatonin, a naturally occurring chemical mediator, although assigned a diverse range of functions, has attracted interest in recent years because of its ability to function as a free radical scavenger. Because of the implications of singlet oxygen in neurotoxicity, the objective of the study was to investigate the ability of melatonin to quench singlet oxygen generated using laser irradiation or lamp photolysis. The results show that melatonin produces radicals upon laser irradation while the lamp photolysis studies show that melatonin is able to scavenge singlet oxygen produced by naphthalene. While melatonin is a free radical scavenger under biological conditions, it acts as a generator of singlet oxygen and or radicals (as ΦΔ is 1.41) when irradiated with laser light, implying that it has the potential to be used in photodynamic therapy in the destruction of tumors.
- Full Text:
- Date Issued: 2005
- Authors: Maharaj, Deepa S , Molell, H , Antunes, Edith M , Maharaj, Hiren , Maree, D M , Nyokong, Tebello , Glass, Beverley D , Daya, Santy
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300335 , vital:57917 , xlink:href="https://doi.org/10.1111/j.1600-079X.2004.00185.x"
- Description: Melatonin, a naturally occurring chemical mediator, although assigned a diverse range of functions, has attracted interest in recent years because of its ability to function as a free radical scavenger. Because of the implications of singlet oxygen in neurotoxicity, the objective of the study was to investigate the ability of melatonin to quench singlet oxygen generated using laser irradiation or lamp photolysis. The results show that melatonin produces radicals upon laser irradation while the lamp photolysis studies show that melatonin is able to scavenge singlet oxygen produced by naphthalene. While melatonin is a free radical scavenger under biological conditions, it acts as a generator of singlet oxygen and or radicals (as ΦΔ is 1.41) when irradiated with laser light, implying that it has the potential to be used in photodynamic therapy in the destruction of tumors.
- Full Text:
- Date Issued: 2005
Language is culture:
- Authors: Malila, Vanessa
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159256 , vital:40281 , https://hdl.handle.net/10520/EJC146402
- Description: Many of us think that English dominates the web pages we surf each day. Indeed, until recently English was the predominant language for publishing online, but things are slowly changing and the presence of linguistic diversity on the Internet is starting to become a reality in the global village. The question, however, remains: how many African languages are represented in that diversity?.
- Full Text:
- Date Issued: 2005
- Authors: Malila, Vanessa
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159256 , vital:40281 , https://hdl.handle.net/10520/EJC146402
- Description: Many of us think that English dominates the web pages we surf each day. Indeed, until recently English was the predominant language for publishing online, but things are slowly changing and the presence of linguistic diversity on the Internet is starting to become a reality in the global village. The question, however, remains: how many African languages are represented in that diversity?.
- Full Text:
- Date Issued: 2005
Photochemical and photophysical properties of pentoxy-and naphthaloxy appended magnesium and zinc phthalocyanines
- Maqanda, Wesiwe, Nyokong, Tebello, Maree, David M
- Authors: Maqanda, Wesiwe , Nyokong, Tebello , Maree, David M
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289260 , vital:56613 , xlink:href="https://doi.org/10.1142/S1088424605000435"
- Description: Photochemical and photophysical measurements were conducted on pentoxy and naphthaloxy appended zinc and magnesium phthalocyanines. We describe in this paper the synthesis as well as unexpected photodegradation behavior of naphthaloxy appended magnesium phthalocyanines. General trends are described for quantum yields of photodegradation, triplet lifetimes and triplet quantum yields as well as singlet oxygen quantum yields of these compounds.
- Full Text:
- Date Issued: 2005
- Authors: Maqanda, Wesiwe , Nyokong, Tebello , Maree, David M
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289260 , vital:56613 , xlink:href="https://doi.org/10.1142/S1088424605000435"
- Description: Photochemical and photophysical measurements were conducted on pentoxy and naphthaloxy appended zinc and magnesium phthalocyanines. We describe in this paper the synthesis as well as unexpected photodegradation behavior of naphthaloxy appended magnesium phthalocyanines. General trends are described for quantum yields of photodegradation, triplet lifetimes and triplet quantum yields as well as singlet oxygen quantum yields of these compounds.
- Full Text:
- Date Issued: 2005
Bastards and bodies in Zoë Wicomb’s David’s Story:
- Authors: Marais, Mike
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144264 , vital:38326 , https://journals.sagepub.com/doi/pdf/10.1177/0021989405056969
- Description: The Population Registration Act of 1950, in the apartheid period of South African history, defined a coloured person as “a person who is not a White person or a Black”. In differentiating coloured from white, coloured from black, and black from white, somatic appearance obviously played a crucial role. So, for instance, a white person was defined as “a person who (a) in appearance obviously is a White person, and who is not generally accepted as a Coloured person; or (b) is generally accepted as a White person and is not in appearance obviously not a White person”.1 It follows that the body of the individual was read as a signifier of racial identity, a hermeneutic practice still prevalent in present-day South Africa. My argument in this essay is that Zoë Wicomb’s David’s Story2 shows how the trope of “pure blood” in the discourse of race not only reduces the body of the individual coloured person to a material sign of racial difference, but also inscribes a history of shame on that body.
- Full Text:
- Date Issued: 2005
- Authors: Marais, Mike
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144264 , vital:38326 , https://journals.sagepub.com/doi/pdf/10.1177/0021989405056969
- Description: The Population Registration Act of 1950, in the apartheid period of South African history, defined a coloured person as “a person who is not a White person or a Black”. In differentiating coloured from white, coloured from black, and black from white, somatic appearance obviously played a crucial role. So, for instance, a white person was defined as “a person who (a) in appearance obviously is a White person, and who is not generally accepted as a Coloured person; or (b) is generally accepted as a White person and is not in appearance obviously not a White person”.1 It follows that the body of the individual was read as a signifier of racial identity, a hermeneutic practice still prevalent in present-day South Africa. My argument in this essay is that Zoë Wicomb’s David’s Story2 shows how the trope of “pure blood” in the discourse of race not only reduces the body of the individual coloured person to a material sign of racial difference, but also inscribes a history of shame on that body.
- Full Text:
- Date Issued: 2005
Attaining a better society: critical reflections on what it means to be 'developed'
- Authors: Matthews, Sally
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142509 , vital:38086 , DOI: 10.3167/004058105780929228
- Description: It is clear from these and other definitions that development, no matter how it is conceived, involves change. However, it is also clear that not all change constitutes development. A particular change could be part of a process of development, but could also be part of several other processes, such as those of alteration, modification, deformation, adaptation, regression, degradation and the like. Thus it is necessary to differentiate between changes that can be said to be part of a process of development, and those that cannot. In an attempt to make such a distinction and in line with the above-mentioned definitions of development one could say that changes that are part of development are changes that bring about increased likeness to some more advanced or better state of being. A six-year-old child who, after years of talking, becomes mute is regressing rather than developing; and a child whose behaviour changes such that she begins to act like a dog would be considered to be in some kind of disordered state. However, when a child’s behaviour undergoes changes that lead to increased similarity to some conception of adult behaviour, then that child can be said to be developing. When assessing whether changes in a child’s behaviour constitute development, or some other kind of process, one has to have in mind some conception of what the child ought to be becoming.
- Full Text:
- Date Issued: 2005
- Authors: Matthews, Sally
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142509 , vital:38086 , DOI: 10.3167/004058105780929228
- Description: It is clear from these and other definitions that development, no matter how it is conceived, involves change. However, it is also clear that not all change constitutes development. A particular change could be part of a process of development, but could also be part of several other processes, such as those of alteration, modification, deformation, adaptation, regression, degradation and the like. Thus it is necessary to differentiate between changes that can be said to be part of a process of development, and those that cannot. In an attempt to make such a distinction and in line with the above-mentioned definitions of development one could say that changes that are part of development are changes that bring about increased likeness to some more advanced or better state of being. A six-year-old child who, after years of talking, becomes mute is regressing rather than developing; and a child whose behaviour changes such that she begins to act like a dog would be considered to be in some kind of disordered state. However, when a child’s behaviour undergoes changes that lead to increased similarity to some conception of adult behaviour, then that child can be said to be developing. When assessing whether changes in a child’s behaviour constitute development, or some other kind of process, one has to have in mind some conception of what the child ought to be becoming.
- Full Text:
- Date Issued: 2005
The environmental Kuznets curve: a literature survey
- Nahman, Anton, Antrobus, Geoffrey G
- Authors: Nahman, Anton , Antrobus, Geoffrey G
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143191 , vital:38209 , DOI: 10.1111/j.1813-6982.2005.00008.x
- Description: Literature on the environmental Kuznets curve (EKC) is examined, focussing on the possibility that the EKC may be explained by trade patterns. If significant, this trade effect would cast doubt on the oft‐stated conclusion that economic growth automatically leads to environmental improvement. Research has been insufficient, although a number of promising approaches have been developed. Although evidence on the pollution‐haven hypothesis is mixed, there is enough to suggest that the EKC development path may not be available to today's developing countries. Other problems cast doubt on whether the EKC exists in any relevant sense at all.
- Full Text:
- Date Issued: 2005
- Authors: Nahman, Anton , Antrobus, Geoffrey G
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143191 , vital:38209 , DOI: 10.1111/j.1813-6982.2005.00008.x
- Description: Literature on the environmental Kuznets curve (EKC) is examined, focussing on the possibility that the EKC may be explained by trade patterns. If significant, this trade effect would cast doubt on the oft‐stated conclusion that economic growth automatically leads to environmental improvement. Research has been insufficient, although a number of promising approaches have been developed. Although evidence on the pollution‐haven hypothesis is mixed, there is enough to suggest that the EKC development path may not be available to today's developing countries. Other problems cast doubt on whether the EKC exists in any relevant sense at all.
- Full Text:
- Date Issued: 2005