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
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
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
Immobilized cobalt (II) phthalocyanine–cobalt (II) porphyrin pentamer at a glassy carbon electrode
- Ozoemena, Kenneth I, Zhao, Zhixin, Nyokong, Tebello
- Authors: Ozoemena, Kenneth I , Zhao, Zhixin , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300322 , vital:57916 , xlink:href="https://doi.org/10.1016/j.elecom.2005.04.019"
- Description: This communication describes the electrochemistry of a novel cobalt phthalocyanine–cobalt porphyrin (cobalt(II)phthalocyanine–cobalt(II)tetra(5-phenoxy-10,15,20-triphenylporphyrin)) (CoPc-(CoTPP)4) immobilised onto a glassy carbon electrode (GCE). The GCE-CoPc-(CoTPP)4 displayed high efficiency as a potential amperometric sensor for hydrogen peroxide (H2O2) in neutral and alkaline pH conditions. Electrochemical and electrocatalytic properties of the pentamer seem to depend mostly on the central CoPc, and partly, on the synergistic effect of the CoPc/CoPP units. The GCE-CoPc-(CoTPP)4 showed very fast amperometric response (∼1 s), with linearities up to ⩾1.50 mM, low detection limits (μM range) and stability (8 weeks) towards the amperometric determination of laboratory and medical solutions of H2O2.
- Full Text:
- Date Issued: 2005
- Authors: Ozoemena, Kenneth I , Zhao, Zhixin , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300322 , vital:57916 , xlink:href="https://doi.org/10.1016/j.elecom.2005.04.019"
- Description: This communication describes the electrochemistry of a novel cobalt phthalocyanine–cobalt porphyrin (cobalt(II)phthalocyanine–cobalt(II)tetra(5-phenoxy-10,15,20-triphenylporphyrin)) (CoPc-(CoTPP)4) immobilised onto a glassy carbon electrode (GCE). The GCE-CoPc-(CoTPP)4 displayed high efficiency as a potential amperometric sensor for hydrogen peroxide (H2O2) in neutral and alkaline pH conditions. Electrochemical and electrocatalytic properties of the pentamer seem to depend mostly on the central CoPc, and partly, on the synergistic effect of the CoPc/CoPP units. The GCE-CoPc-(CoTPP)4 showed very fast amperometric response (∼1 s), with linearities up to ⩾1.50 mM, low detection limits (μM range) and stability (8 weeks) towards the amperometric determination of laboratory and medical solutions of H2O2.
- Full Text:
- Date Issued: 2005
In-kernel cryptographic executable verification
- Motara, Yusuf, M, Irwin, Barry V W
- Authors: Motara, Yusuf, M , Irwin, Barry V W
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429049 , vital:72556 , https://doi.org/10.1007/0-387-31163-7_25
- Description: This paper discusses the problems posed by Trojan horses and unauthorized code, and reviews existing solutions for dealing with them. A technique involving the in-kernel verification of executables is proposed. Its advantages include simplicity, transparency, ease of use and minimal setup time. In addition, the technique has several applications, including assisting with honeypot implementations, incident response and forensic investigations.
- Full Text:
- Date Issued: 2005
- Authors: Motara, Yusuf, M , Irwin, Barry V W
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429049 , vital:72556 , https://doi.org/10.1007/0-387-31163-7_25
- Description: This paper discusses the problems posed by Trojan horses and unauthorized code, and reviews existing solutions for dealing with them. A technique involving the in-kernel verification of executables is proposed. Its advantages include simplicity, transparency, ease of use and minimal setup time. In addition, the technique has several applications, including assisting with honeypot implementations, incident response and forensic investigations.
- Full Text:
- Date Issued: 2005
In-kernel cryptographic executable verification
- Motara, Yusuf, M, Irwin, Barry V W
- Authors: Motara, Yusuf, M , Irwin, Barry V W
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429937 , vital:72653 , https://doi.org/10.1007/0-387-31163-7_25
- Description: This paper discusses the problems posed by Trojan horses and unau-thorized code, and reviews existing solutions for dealing with them. A technique involving the in-kernel verification of executables is pro-posed. Its advantages include simplicity, transparency, ease of use and minimal setup time. In addition, the technique has several applications, including assisting with honeypot implementations, incident response and forensic investigations.
- Full Text:
- Date Issued: 2005
- Authors: Motara, Yusuf, M , Irwin, Barry V W
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429937 , vital:72653 , https://doi.org/10.1007/0-387-31163-7_25
- Description: This paper discusses the problems posed by Trojan horses and unau-thorized code, and reviews existing solutions for dealing with them. A technique involving the in-kernel verification of executables is pro-posed. Its advantages include simplicity, transparency, ease of use and minimal setup time. In addition, the technique has several applications, including assisting with honeypot implementations, incident response and forensic investigations.
- 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
Life history of the springhare (Pedetes capensis) from a strongly seasonal environment in the Eastern Cape Province of South Africa
- Peinke, Dean, Bernard, Ric T F
- Authors: Peinke, Dean , Bernard, Ric T F
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447089 , vital:74583 , doi.org/10.1080/15627020.2005.11407327
- Description: The life history of the springhare (Pedetes capensis, Forster, 1778) at 33°S, in the Eastern Cape Province of South Africa, was characterized by continuous, aseasonal and asynchronous reproduction. Females were monotocous and consecutive pregnancies were separated by a non pregnant period (30–50 days) similar in length to the period of lactation. Young were relatively large at birth (8% of adult body weight) but were altricial and only emerged from the burrow at weaning. Towards the end of lactation, many females mated again (20% of all females were both lactating and in early pregnancy) and annual fecundity was probably two but never more than three. For a rodent, albeit a large one, this is a very slow rate of reproduction and we propose that the ricochetal locomotion (jumping on the hind legs) and semi-fossorial life style of the springhare will have resulted in decreased juvenile and adult mortality, and increased longevity, and that these factors have shaped the evolution of the life history of the springhare.
- Full Text:
- Date Issued: 2005
- Authors: Peinke, Dean , Bernard, Ric T F
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447089 , vital:74583 , doi.org/10.1080/15627020.2005.11407327
- Description: The life history of the springhare (Pedetes capensis, Forster, 1778) at 33°S, in the Eastern Cape Province of South Africa, was characterized by continuous, aseasonal and asynchronous reproduction. Females were monotocous and consecutive pregnancies were separated by a non pregnant period (30–50 days) similar in length to the period of lactation. Young were relatively large at birth (8% of adult body weight) but were altricial and only emerged from the burrow at weaning. Towards the end of lactation, many females mated again (20% of all females were both lactating and in early pregnancy) and annual fecundity was probably two but never more than three. For a rodent, albeit a large one, this is a very slow rate of reproduction and we propose that the ricochetal locomotion (jumping on the hind legs) and semi-fossorial life style of the springhare will have resulted in decreased juvenile and adult mortality, and increased longevity, and that these factors have shaped the evolution of the life history of the springhare.
- Full Text:
- Date Issued: 2005
Mainstreaming Gender Standards in Collective Bargaining
- COSATU
- Authors: COSATU
- Date: 2005
- Subjects: COSATU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/154231 , vital:39624
- Description: The apartheid system and capitalism used the patriarchal nature of the South African society through the sexual division of labour and divided the labour force on the grounds of class, race and gender to exploit them for cheap labour to maximize their profits. They exploited the notion of men as the head of the family to force men to become migrant labourers and disregarded the reproductive and domestic role of women.
- Full Text:
- Date Issued: 2005
- Authors: COSATU
- Date: 2005
- Subjects: COSATU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/154231 , vital:39624
- Description: The apartheid system and capitalism used the patriarchal nature of the South African society through the sexual division of labour and divided the labour force on the grounds of class, race and gender to exploit them for cheap labour to maximize their profits. They exploited the notion of men as the head of the family to force men to become migrant labourers and disregarded the reproductive and domestic role of women.
- 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
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
Methodological Decisions in Context: The dilemmas and challenges of novice African scholars
- Lupele, Justin, Mwingi, Mweru P, Kinyanjui, Felistus, Kimani, Joyce, Kisamba, Christine
- Authors: Lupele, Justin , Mwingi, Mweru P , 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 P , 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
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
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
Multivariate analysis of honeybees, Apis mellifera Linnaeus (Hymenoptera: Apidae) of the northeastern and southern regions of Algeria.
- Barour, C, Tahar, A, Radloff, Sarah E, Hepburn, H Randall
- Authors: Barour, C , Tahar, A , Radloff, Sarah E , Hepburn, H Randall
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451976 , vital:75092 , https://hdl.handle.net/10520/EJC32628
- Description: Morphometric characters of worker honeybees, Apis mellifera Linnaeus, were analysed by multivariate methods to characterize their populations in the northeastern and southern regions (ecological-climatological zones) of Algeria, from 36°55' to 32°25'N and 3°39' to 8°22'E. Three morphoclusters were identified by using principal components and linear discriminant analyses. The bees are identified as Apis mellifera intermissa Buttel-Reepen.
- Full Text:
- Date Issued: 2005
- Authors: Barour, C , Tahar, A , Radloff, Sarah E , Hepburn, H Randall
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451976 , vital:75092 , https://hdl.handle.net/10520/EJC32628
- Description: Morphometric characters of worker honeybees, Apis mellifera Linnaeus, were analysed by multivariate methods to characterize their populations in the northeastern and southern regions (ecological-climatological zones) of Algeria, from 36°55' to 32°25'N and 3°39' to 8°22'E. Three morphoclusters were identified by using principal components and linear discriminant analyses. The bees are identified as Apis mellifera intermissa Buttel-Reepen.
- 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
Photophysical and photochemical studies of sulphonated non-transition metal phthalocyanines in aqueous and non-aqueous media
- Ogunsipe, Abimbola, Nyokong, Tebello
- Authors: Ogunsipe, Abimbola , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289271 , vital:56614 , xlink:href="https://doi.org/10.1016/j.jphotochem.2005.03.001"
- Description: The photophysical and photochemical parameters for mixed sulphonated metallophthalocyanine complexes (AlPcSmix, SiPcSmix, GePcSmix, SnPcSmix, and ZnPcSmix) are reported in phosphate buffer saline (PBS, pH 7.4), PBS containing the surfactant Triton X-100, and in dimethylsulphoxide (DMSO). The ground state spectra of SiPcSmix, GePcSmix and SnPcSmix show splitting of the Q-band in DMSO, but the fluorescence spectra have only one band, suggesting that only some components of the mixed complexes fluoresce. In general the quantum yields of fluorescence (ΦF) were smaller in DMSO compared to the aqueous solvents, while quantum yields of triplet state (ΦT) were larger in DMSO. Triplet lifetimes were much lower in aqueous solutions (compared to DMSO) due to the fact that water absorbs strongly around 1108 nm, which corresponds to the triplet energy of a metallophthalocyanine complex. The MPcSmix complexes quenched hydroquinone, and the Stern–Volmer constants follow the order: AlPcSmix > SiPcSmix > GePcSmix > ZnPcSmix > SnPcSmix which is the order of the extinction coefficients (of the low energy band for complexes with split Q-band) of these molecules. The rate constants for fluorescence, intersystem crossing, internal conversion, and photodegradation were determined from the hydroquinone quenching data.
- Full Text:
- Date Issued: 2005
- Authors: Ogunsipe, Abimbola , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289271 , vital:56614 , xlink:href="https://doi.org/10.1016/j.jphotochem.2005.03.001"
- Description: The photophysical and photochemical parameters for mixed sulphonated metallophthalocyanine complexes (AlPcSmix, SiPcSmix, GePcSmix, SnPcSmix, and ZnPcSmix) are reported in phosphate buffer saline (PBS, pH 7.4), PBS containing the surfactant Triton X-100, and in dimethylsulphoxide (DMSO). The ground state spectra of SiPcSmix, GePcSmix and SnPcSmix show splitting of the Q-band in DMSO, but the fluorescence spectra have only one band, suggesting that only some components of the mixed complexes fluoresce. In general the quantum yields of fluorescence (ΦF) were smaller in DMSO compared to the aqueous solvents, while quantum yields of triplet state (ΦT) were larger in DMSO. Triplet lifetimes were much lower in aqueous solutions (compared to DMSO) due to the fact that water absorbs strongly around 1108 nm, which corresponds to the triplet energy of a metallophthalocyanine complex. The MPcSmix complexes quenched hydroquinone, and the Stern–Volmer constants follow the order: AlPcSmix > SiPcSmix > GePcSmix > ZnPcSmix > SnPcSmix which is the order of the extinction coefficients (of the low energy band for complexes with split Q-band) of these molecules. The rate constants for fluorescence, intersystem crossing, internal conversion, and photodegradation were determined from the hydroquinone quenching data.
- Full Text:
- Date Issued: 2005
Photophysical properties of a water-soluble adjacently substituted bisnaphthalophthalocyanine
- Seotsanyana-Mokhosi, Itumeleng, Nyokong, Tebello
- Authors: Seotsanyana-Mokhosi, Itumeleng , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286091 , vital:56237 , xlink:href="https://doi.org/10.1142/S1088424605000599"
- Description: Spectral properties of a water soluble metal free tetracarboxyphenoxy bisnaphthalo-phthalocyanine (3) were studied in water and organic solvents. It was found that in protic solvents, complex 3 was highly aggregated. The surfactant, Triton X100, and bovineserum albumin (BSA) do not effect disaggregation while cetyl trimethylammonium chloride (CTAC) caused the molecule to disaggregate. The fluorescence quantum yields were higher in the presence of CTAC. Studying the interaction of BSA with complex 3 using fluorometry revealed that BSA is highly quenched by the latter. A 1:1 stoichiometric binding ratio between BSA and the Pc was found. Triplet quantum yields in water containing CTAC were higher than in organic solvents.
- Full Text:
- Date Issued: 2005
- Authors: Seotsanyana-Mokhosi, Itumeleng , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286091 , vital:56237 , xlink:href="https://doi.org/10.1142/S1088424605000599"
- Description: Spectral properties of a water soluble metal free tetracarboxyphenoxy bisnaphthalo-phthalocyanine (3) were studied in water and organic solvents. It was found that in protic solvents, complex 3 was highly aggregated. The surfactant, Triton X100, and bovineserum albumin (BSA) do not effect disaggregation while cetyl trimethylammonium chloride (CTAC) caused the molecule to disaggregate. The fluorescence quantum yields were higher in the presence of CTAC. Studying the interaction of BSA with complex 3 using fluorometry revealed that BSA is highly quenched by the latter. A 1:1 stoichiometric binding ratio between BSA and the Pc was found. Triplet quantum yields in water containing CTAC were higher than in organic solvents.
- Full Text:
- Date Issued: 2005
Playing musement games: Retroduction in social research, with particular reference to indigenous knowledge in environmental and health education
- Authors: Price, Leigh
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373763 , vital:66722 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122701"
- Description: My aim here is to introduce the concept of musement (retroduction or abduction) as an appropriate alternative to deduction and induction, both in indigenous knowledge (IK) specifically and in social science generally. As an example, I will use musement to tentatively address some of the ethical problems of using indigenous knowledge (IK) in environmental education and health education. This paper will therefore be of use both to researchers/educators wanting a discussion of retroduction, and researchers/educators wanting a discussion of indigenous knowledge epistemology and its relationship with ethics. I am arguing, from a perspective that allows a stratified reality (things can be real even if not measurable or actually present), that, we admit retroduction into our list of allowable research logics. In terms of IK, the result of accepting retroduction as a valid logic is that we allow IK to be dynamic and non-reified. It also allows a previously ignored aspect of IK, its spiritual/non-empirical beliefs, to be validated through ethical outcomes experienced in our lives, rather than through the previous criteria of empirical validity. In other words, we ask for IK: does believing in (whatever) adequately explain experience and/or provide optimistic, long term, ethical, appropriate ways of living? Thus, retroduction has the potential to allow IK to contribute to a normative ethics.
- Full Text:
- Date Issued: 2005
- Authors: Price, Leigh
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373763 , vital:66722 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122701"
- Description: My aim here is to introduce the concept of musement (retroduction or abduction) as an appropriate alternative to deduction and induction, both in indigenous knowledge (IK) specifically and in social science generally. As an example, I will use musement to tentatively address some of the ethical problems of using indigenous knowledge (IK) in environmental education and health education. This paper will therefore be of use both to researchers/educators wanting a discussion of retroduction, and researchers/educators wanting a discussion of indigenous knowledge epistemology and its relationship with ethics. I am arguing, from a perspective that allows a stratified reality (things can be real even if not measurable or actually present), that, we admit retroduction into our list of allowable research logics. In terms of IK, the result of accepting retroduction as a valid logic is that we allow IK to be dynamic and non-reified. It also allows a previously ignored aspect of IK, its spiritual/non-empirical beliefs, to be validated through ethical outcomes experienced in our lives, rather than through the previous criteria of empirical validity. In other words, we ask for IK: does believing in (whatever) adequately explain experience and/or provide optimistic, long term, ethical, appropriate ways of living? Thus, retroduction has the potential to allow IK to contribute to a normative ethics.
- Full Text:
- Date Issued: 2005
Primary caregivers' experience of raising children with autism: a phenomenological perspective
- Authors: Swanepoel, Yolandi
- Date: 2005
- Subjects: Autism in children Autistic children Autism in children -- Diagnosis Parents of autistic children
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:3067 , http://hdl.handle.net/10962/d1002576
- Description: Autism occupies an extreme position among childhood pathologies due to its severity, duration and impact on the family. In this qualitative study, four primary caregivers of autistic children were interviewed regarding their experiences of the diagnostic process, their post-diagnostic adjustment, and how helping professionals can improve their service rendering to these families. This study utilised a phenomenological approach to look at primary caregivers as the best-informed authority to explore and describe their lived realities and experiences of raising their autistic children in South Africa. The rationale for a phenomenological approach in this study is that such an interpretative inquiry enables material to be collected and analysed within the specific context of the subjective realities of primary caregivers of autistic children in South Africa. The researcher utilised semi-structured, in-depth, face-to-face interviews as method of data collection. Each participant was interviewed over the course of three separate interviews. The themes and categories that resulted from a content analysis of the material were grouped into two broad fields of experience, namely: (1) experiences surrounding the diagnostic process; and (2) the pervasive influence of autism on different areas of family life. In terms of experiences surrounding children’s diagnosis, four themes were identified: (1) Being a new parent and making sense out of chaos; (2) Responsibility and blame; (3) Confusion and disillusionment during early experiences with helping professionals; and (4) Feelings about the diagnosis. The pervasive influence of autism on different areas of family life includes: (5) Strained family relationships; (6) Challenges of behaviour management and disciplining the autistic child; (7) Challenges of finding suitable resources for education and day-care; and (8) Maintaining the family unit and doing things as a family.
- Full Text:
- Date Issued: 2005
- Authors: Swanepoel, Yolandi
- Date: 2005
- Subjects: Autism in children Autistic children Autism in children -- Diagnosis Parents of autistic children
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:3067 , http://hdl.handle.net/10962/d1002576
- Description: Autism occupies an extreme position among childhood pathologies due to its severity, duration and impact on the family. In this qualitative study, four primary caregivers of autistic children were interviewed regarding their experiences of the diagnostic process, their post-diagnostic adjustment, and how helping professionals can improve their service rendering to these families. This study utilised a phenomenological approach to look at primary caregivers as the best-informed authority to explore and describe their lived realities and experiences of raising their autistic children in South Africa. The rationale for a phenomenological approach in this study is that such an interpretative inquiry enables material to be collected and analysed within the specific context of the subjective realities of primary caregivers of autistic children in South Africa. The researcher utilised semi-structured, in-depth, face-to-face interviews as method of data collection. Each participant was interviewed over the course of three separate interviews. The themes and categories that resulted from a content analysis of the material were grouped into two broad fields of experience, namely: (1) experiences surrounding the diagnostic process; and (2) the pervasive influence of autism on different areas of family life. In terms of experiences surrounding children’s diagnosis, four themes were identified: (1) Being a new parent and making sense out of chaos; (2) Responsibility and blame; (3) Confusion and disillusionment during early experiences with helping professionals; and (4) Feelings about the diagnosis. The pervasive influence of autism on different areas of family life includes: (5) Strained family relationships; (6) Challenges of behaviour management and disciplining the autistic child; (7) Challenges of finding suitable resources for education and day-care; and (8) Maintaining the family unit and doing things as a family.
- Full Text:
- Date Issued: 2005