Laboratory investigation of a load carriage task observed in forestry
- Authors: Furney, Sheena Elizabeth
- Date: 2007
- Subjects: Work -- Physiological aspects , Foresters -- Workload , Human engineering , Lifting and carrying
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5145 , http://hdl.handle.net/10962/d1008188 , Work -- Physiological aspects , Foresters -- Workload , Human engineering , Lifting and carrying
- Description: The objective of the present study was to investigate and compare the human responses to two load carriage tasks performed with three different load masses and on three different gradients. The task of carrying hydrogel in one hand was observed in a silviculture industry and crude physiological and perceptual responses were measured. This task was simulated in a laboratory setting together with a suggested intervention of backpack carriage. Eighteen conditions were established which consisted of the two modes of carriage and a combination of three load masses (9kg, 12kg and 15kg) and three gradients (5%, 10% and 15%). Twenty eight Rhodes University female students comprised the sample and the experimental procedures were conducted on a Quinton treadmill. Each participant was required to complete nine of the eighteen conditions which were each four minutes in duration. Postural changes were assessed using lateral and posterior digital images taken at the second and fourth minute and compression and shearing forces were estimated with the ErgolmagerTM Physiological responses (heart rate, ventilation and metabolic responses) were measured continuously with the Quark b² and perceptual responses ('central' and 'local' RPE) were measured every minute during the experimentation and body discomfort was rated at the completion of each condition. Overall responses revealed that hand carriage (146 bt.min⁻¹ , 25.09 mIO₂. kg-l.min⁻¹) was generally found to be more physiologically stressful than backpack carriage (130 bt.min⁻¹, 22.15 mIO₂.kg⁻¹ .min⁻¹) independent of load mass and gradient. Physiological responses were higher (113 bt.min-1 to 174 bt.min⁻¹ ) in responses to increasing gradient as opposed to increasing load mass (104 bt.min-1 to 153 bt.min⁻¹ ) for both backpack and hand carriage. Categorisation using the guidelines of Sanders and McCormick (1993) allowed for classification of conditions, with respect to physiological responses, into 'moderate', 'heavy' and 'very heavy' stress. For almost all of the physiological responses the majority of conditions which were classified as 'moderate' were backpack carriage conditions and the conditions classified as 'very heavy' were mostly hand carriage conditions. In terms of postural responses hand carriage resulted in more strain and greater compression and shearing forces on the spine. In terms of the compression forces increasing gradient had a greater affect on backpack carriage (681 N to 935 N) compared to hand carriage (570N to 793N). In contrast, increasing load mass had a larger affect on hand carriage postures and compression forces (751 N to 935N) in comparison to backpack carriage (723N to 780N). Shearing forces were found to be worse in hand carriage conditions overall. Although participants generally underrated perceived exertion in relation to cardiorespiratory responses, these perceptions revealed that backpack carriage, with a mean 'central' RPE of 12 compared to 11 for hand carriage, was somewhat preferred to hand carriage and that increasing gradient was perceived to be marginally more straining than increasing load mass.
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Limiting vulnerability exposure through effective patch management: threat mitigation through vulnerability remediation
- Authors: White, Dominic Stjohn Dolin
- Date: 2007 , 2007-02-08
- Subjects: Computer networks -- Security measures , Computer viruses , Computer security
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4629 , http://hdl.handle.net/10962/d1006510 , Computer networks -- Security measures , Computer viruses , Computer security
- Description: This document aims to provide a complete discussion on vulnerability and patch management. The first chapters look at the trends relating to vulnerabilities, exploits, attacks and patches. These trends describe the drivers of patch and vulnerability management and situate the discussion in the current security climate. The following chapters then aim to present both policy and technical solutions to the problem. The policies described lay out a comprehensive set of steps that can be followed by any organisation to implement their own patch management policy, including practical advice on integration with other policies, managing risk, identifying vulnerability, strategies for reducing downtime and generating metrics to measure progress. Having covered the steps that can be taken by users, a strategy describing how best a vendor should implement a related patch release policy is provided. An argument is made that current monthly patch release schedules are inadequate to allow users to most effectively and timeously mitigate vulnerabilities. The final chapters discuss the technical aspect of automating parts of the policies described. In particular the concept of 'defense in depth' is used to discuss additional strategies for 'buying time' during the patch process. The document then goes on to conclude that in the face of increasing malicious activity and more complex patching, solid frameworks such as those provided in this document are required to ensure an organisation can fully manage the patching process. However, more research is required to fully understand vulnerabilities and exploits. In particular more attention must be paid to threats, as little work as been done to fully understand threat-agent capabilities and activities from a day to day basis. , TeX output 2007.02.08:2212 , Adobe Acrobat 9.51 Paper Capture Plug-in
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Local food choices and nutrition : a case study of amarewu in the FET consumer studies curriculum
- Authors: Kota, Lutho Siyabulela
- Date: 2007
- Subjects: Continuing education -- South Africa -- Eastern Cape -- Curricula Education -- South Africa -- Eastern Cape -- Curricula Ethnoscience -- South Africa -- Eastern Cape Indigenous peoples -- Study and teaching -- South Africa -- Eastern Cape Nutrition -- Study and teaching -- South Africa--Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1666 , http://hdl.handle.net/10962/d1003549
- Description: This case study examines the introduction of Indigenous Knowledge (IK) in the Consumer Studies curriculum of Further Education and Training (FET). The research is centred on the use of enquiry methodologies involving learners observing parent demonstrations of the making of ‘amarewu’ and other activities centred on the propositional knowledge dealing with fermentation in the Consumer Studies curriculum. The research involved a review of curriculum documents, participant observation of a demonstration of local food practices related to ‘amarewu’ and learner research activities and interviews to review the developing learning interactions. The learning activities were focused on the learners’ researching the cultural and nutritional value of ‘amarewu’ and included an audit of food consumed in the community. What transpired from this study was that working with IK in the curriculum is possible. The inclusion of IK is not only possible but desirable and has exciting possibilities for relevance in contemporary education. The active involvement in parent demonstration engaged the learners in IK in their mother tongue, therefore indigenous knowledge has relevance. The curriculum concepts also enhanced the engagement by giving rise to more relevant knowledge and a respect for cultural matters. Intergenerational capital and subject concepts also enabled learners to engage with local nutritional problems and to come up with practical solutions. This study demonstrates how IK intergenerational capital in combination in combination with curriculum concepts (subject knowledge capital) can enhance relevance and the learners’ real engagement with local health and nutritional problems. Not only did the learners have culturally valued knowledge, but also knowledge that has a practical grasp of the problem and that they could use to engage relevant issues. These two views of knowledge join in learning and can be used to address health issues. I therefore recommend connection of cultural knowledge and conceptual knowledge to strengthen the revitalisation of cultural heritage, thus equalising it to the modern patterns of life and enhancing meaningful curriculum orientation.
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Localisation of Theiler's Murine Encephalomyelitis virus non-structural proteins 2B, 2C, 2BC and 3A in BHK-21 cells, and the effect of amino acid substitutions in 2C on localisation and virus replication
- Authors: Murray, Lindsay
- Date: 2007
- Subjects: Encephalomyelitis -- Genetic aspects , Amino acid sequence , Picornaviruses , Viruses -- Reproduction
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4090 , http://hdl.handle.net/10962/d1007722 , Encephalomyelitis -- Genetic aspects , Amino acid sequence , Picornaviruses , Viruses -- Reproduction
- Description: The picornavirus family includes significant human and animal viruses such as poliovirus (PV), human rhinovirus (HRV) and foot-and-mouth-disease virus (FMDV). Current disease treatment and control strategies are limited by an incomplete understanding of the interactions between the non-structural, replicative picornavirus proteins and host cell components. To investigate these interactions, Theiler's murine encephalomyelitis virus (TMEV) 2B, 2C, 2BC and 3A proteins were transiently expressed in BHK-21 cells and detected by indirect immunostaining and laser-scanning or epifluorescence microscopy. The signal of the 2B protein overlapped with that of the ER marker protein, ERp60, as well as that of the peripheral Golgi marker protein, β-COP. The 2C protein overlapped with ERp60 in a faint reticular stain, and localised to large punctate structures that partially overlapped with β-COP at higher levels of expression. The 2BC protein located to large perinuclear structures that overlapped exclusively with β-COP. The TMEV 3A protein signal overlapped with both ERp60 and β-COP stains, in addition in cells expressing the 3A protein the ER appeared swollen and bulbous while the Golgi was dispersed in some cells. 2C and 2BC proteins with C-terminal deletions localised in the same manner as the wild type proteins indicating that the localisation signals that determine subcellular localisation of the proteins are within the N-terminal 60 amino acids of the 2C protein. The significance of the high degree of conservation of the N-terminal domain of the 2C protein throughout the Picornaviridae was investigated through the introduction of amino acid substitution mutations at highly conserved residues in the N-terminal domain of 2C into the viral cDNA. Upon transfection of the viral RNA into BHK-21 cells, it was observed that substitution of amino acid residues 8, 18 and 29 abolished the ability of TMEV to induce cytopathic effect (CPE), while substitution of residues 4, 14 and 23 only attenuated the ability of TMEV to induce CPE. To determine whether amino acid substitution mutations would affect the localisation of the 2C protein, 2C proteins with substitution mutations at amino acids 4, 8, 14, 18, 23 and 29 were transiently expressed in BHK-21 cells and detected by indirect imrnunostaining and examination by laser-scanning confocal and epifluorescence microscopy. The 2C mutant 4, 8 and 29 proteins showed slightly altered localisation patterns compared to the wild type protein with a significant portion of the proteins localising in a perinuclear stain suggesting possible localisation to the nuclear envelop. The 2C mutant 14 and 18 proteins localised to a diffuse pattern in BHK-21 cells while the 2C mutant 23 protein located to small punctate structures that partially overlapped with the ERp60 stain but were completely separate from the β-COP stain. Finally, a hydrophilic, antigenic region of the 2C protein was expressed in frame with an N-terminal GST tag and was successfully purified on a pilot-scale and detected by Western analysis. This 2C178 peptide will be used to generate antibodies against the 2C and 2BC proteins for use in future studies. This study has furthered our knowledge of the localisation of the picornavirus 2B, 2C, 2BC and 3A proteins in host cells and identified a possible link between this localisation and an ability of TMEV to replicate in BHK-21 cells.
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Making visual literacy meaningful in a rural context: an action research case study
- Authors: Mbelani, Madeyandile
- Date: 2007
- Subjects: Visual literacy -- Study and teaching (Secondary) -- South Africa -- Eastern Cape -- Case studies Education -- Research -- Case studies Education -- Research -- South Africa -- Eastern Cape Rural schools -- Research -- Case studies Rural schools -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1668 , http://hdl.handle.net/10962/d1003551
- Description: This thesis reports on a collaborative action research case study into the teaching of visual literacy to Grade 10 learners in a rural high school in the Eastern Cape, South Africa. Visual literacy is one of the critical aspects that have been incorporated in the teaching of English First Additional Language as required by the National Curriculum Statement (Grade 10-12), which has been implemented in Grade 10 as from 2006. With the aim of improving learners’ performance in visual literacy I designed a visual literacy unit that consisted of lesson plans running over 7 periods in 10 school days. In implementing the unit the learners were first grouped and then exposed to visual grammar and visual texts and then they critically viewed such texts and designed their own. Data was collected daily in the form of individual learner journals, researcher’s journal/diary, and copies were kept of activities done by learners (individually or in groups). Also, two teachers were invited as non-participant observers to each visit a lesson. Learner focus groups were conducted and critical friends were interviewed, tape recorded and transcribed. A camera was used to take still photographs to show learner activities in groups and during group presentations. The data revealed that visual literacy could be taught meaningfully in a rural high school as the learners could identify, cut, paste and discuss elements of visual language and they finally designed their own advertisements in groups. In the analysis of data the following factors emerged as hindrances for successful teaching of visual literacy in a rural high school: lack of resources; learners’ lack of a foundation in visual literacy from Grades 7-9; and problems revolving around time management and pacing. As action research comes in spirals, this research represented the first one and the researcher found the study an eye opener and a foundation to build on in the second spiral (that is not part of this research).
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Management of invasive aquatic weeds with emphasis on biological control in Senegal
- Authors: Diop, Ousseynou
- Date: 2007
- Subjects: Aquatic weeds -- Biological control -- Senegal Invasive plants -- Biological control -- Senegal Aquatic plants -- Biological control -- Senegal
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5728 , http://hdl.handle.net/10962/d1005414
- Description: In 1985 the Diama Dam was built near the mouth of the Senegal River to regulate flows during the rainy season and prevent the intrusion of seawater during the dry season. This created ideal conditions upstream of the dam wall for invasion by two highly invasive aquatic weeds, first by water lettuce Pistia stratiotes Linnaeus (Araceae) in 1993, and then by salvinia Salvinia molesta D.S. Mitchell (Salviniaceae) in 1999. This study was focused on the management of P. stratiotes and S. molesta. Following successes that were achieved elsewhere in the world, biological control programmes involving two weevil species were inaugurated against both weeds and research was focused on several aspects. These included pre-release studies to determine the weevils' host-specificity and impact on the plants in the laboratory, their subsequent mass-rearing and releases at selected sites and post-release evaluations on their impact on the weed populations in the field. Both programmes, which reprepresented the first biocontrol efforts against aquatic weeds in Senegal, proved highly successful with severe damage inflicted on the weed populations and complete control achieved within a relatively short time span. A laboratory exclusion experiment with N. affinis on P. stratiotes showed that in treated tubs, the weevil strongly depressed plant performance as measured by the plant growth parameters: mass, rosette diameter, root length, number of leaves and daughter plants whereas control plants were healthy. Field releases started in September 1994 and water coverage by P. stratiotes at Lake Guiers was reduced by 25% in January 1995 and 50% in April 1995. A general decline of 65% in water coverage by P. stratiotes was observed in June 1995 and by August 1995, eight months after releases P. stratiotes mats were destroyed. Further, although no releases were made there, good results were obtained within 18 months at Djoudj Park water bodies, located 150 km NW from Lake Guiers indicating the potential of the weevil to disperse long distances. In 2005, P. stratiotes reappeared and the weevil N. affinis has located and controlled all of these P. stratiotes recurrences after new releases. In 1999, S. molesta covered an estimated area of 18 000 ha on the Senegal River Left Bank and tributaries (Senegal) and 7 840 ha on the Senegal River Right Bank (Mauritania). Military and Civil Development Committee (CCMAD) and community volunteers made an effort to control S. molesta using physical removal, but this costly and labour-intensive approach was unsustainable. Hence, biological control was adopted by Senegal and Mauritania to manage the weed. Host range tests to assess feeding by C. salviniae on S. molesta and non-target plants and carried out on 13 crop species showed that no feeding damage was observed on the latter and weevils only fed on S. molesta. Field releases of some 48 953 weevils at 270 sites were made from early January 2002 to August 2002. Within one year, weevils were established and were being recovered up to 50 km from the release sites. In a case study conducted at one of the release sites, the S. molesta infestation was reduced from 100% to less than 3% 24 months after release. These results are discussed in the context of the weeds’ negative impact on aquatic systems and riverside communities, and in the involvement of these communities in the programmes.
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Measuring the RFI environment of the South African SKA site
- Authors: Manners, Paul John
- Date: 2007
- Subjects: Radio telescopes , Radio telescopes -- South Africa , Radio astronomy , Radio astronomy -- South Africa , Square Kilometer Array (Spacecraft) , Radio -- Interference -- Measurement
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5474 , http://hdl.handle.net/10962/d1005259 , Radio telescopes , Radio telescopes -- South Africa , Radio astronomy , Radio astronomy -- South Africa , Square Kilometer Array (Spacecraft) , Radio -- Interference -- Measurement
- Description: The Square Kilometre Array (SKA) Project is an international effort to build the world’s largest radio telescope. It will be 100 times more sensitive than any other radio telescope currently in existence and will consist of thousands of dishes placed at baselines up to 3000 km. In addition to its increased sensitivity it will operate over a very wide frequency range (current specification is 100 MHz - 22 GHz) and will use frequency bands not primarily allocated to radio astronomy. Because of this the telescope needs to be located at a site with low levels of radio frequency interference (RFI). This implies a site that is remote and away from human activity. In bidding to host the SKA, South Africa was required to conduct an RFI survey at its proposed site for a period of 12 months. Apart from this core site, where more than half the SKA dishes may potentially be deployed, the measurement of remote sites in Southern Africa was also required. To conduct measurements at these sites, three mobile measurement systems were designed and built by the South African SKA Project. The design considerations, implementation and RFI measurements recorded during this campaign will be the focus for this dissertation.
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Molecular characterisation of the chaperone properties of Plasmodium falciparum heat shock protein 70
- Authors: Shonhai, Addmore
- Date: 2007
- Subjects: Heat shock proteins Plasmodium falciparum Protein folding Proteins -- Purification Molecular chaperones Malaria -- Prevention
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3977 , http://hdl.handle.net/10962/d1004036
- Description: Heat shock protein 70 (called DnaK in prokaryotes) is one of the most prominent groups of chaperones whose role is to prevent and reverse protein misfolding. PfHsp70 is a heatinducible cytoplasm/nuclear localised Plasmodium falciparum Hsp70. PfHsp70 is thought to confer chaperone cytoprotection to P. falciparum during the development of malaria fever. The objective of this study was to examine the chaperone properties of PfHsp70 using a bioinformatics approach, coupled to in vivo and in vitro analysis. Structural motifs that qualify PfHsp70 as a typical Hsp70 chaperone were identified. Although PfHsp70 has a higher similarity to human Hsc70 than E. coli DnaK, in vivocomplementation assays showed that PfHsp70 was able to reverse the thermosensitivity of E. coli dnaK756 (a temperature sensitive strain whose DnaK is functionally compromised). Two residues (V401 and Q402) in the linker region of PfHsp70 that are critical for its in vivo function were identified. Constructs were generated that encoded the ATPase domain of PfHsp70 and the peptide binding domain of E. coli DnaK (to generate PfK chimera); and the ATPase domain of E. coli DnaK fused to the peptide binding domain of PfHsp70 (KPf). The two chimeras were tested for their ability to reverse the thermosensitivity of E. coli dnaK756 cells. Whilst KPf was able to reverse the thermosensitivity of the E. coli dnaK756 cells, PfK could not. Previously, PfHsp70 purification involved urea denaturation. Using a detergent, polyethylenimine (PEI), PfHsp70 was natively purified. Natively purified PfHsp70 had a basal ATPase activity approximately two times higher than the previously reported activity for the protein purified through urea denaturation. PfJ4, a type II Hsp40, could not stimulate the ATPase activity of PfHsp70 in vitro. Arch and hydrophobic pocket substitutions (A419Y, Y444A and V451F) were introduced in the PfHsp70 peptide binding domain. Similar substitutions were also introduced in the KPf chimera. PfHsp70-V451F (hydrophobic pocket mutant) had marginally compromised in vivo function. However, a similar mutation (V436F), introduced in KPf abrogated the in vivo function of this chimera. The arch and hydrophobic pocket derivatives of PfHsp70 exhibited marginally compromised in vivo function, whilst equivalent mutations in KPf did not affect its in vivo function. The ability of PfHsp70 and its arch/hydrophobic pocket mutants to suppress the heatinduced aggregation of malate dehydrogenase (MDH) in vitro was investigated. Whilst PfHsp70 arch mutants displayed marginal functional loss in vivo, data from in vitro studies revealed that their functional deficiencies were more severe. This is the first study in which an Hsp70 from a parasitic eukaryote was able to suppress the thermosensitivity of an E. coli DnaK mutant strain. Findings from the in vivo and in vitro assays conducted on PfHsp70 suggest that this protein plays a key role in the life-cycle of P. falciparum. Furthermore, this study raised insights that are pertinent to the current dogma on the Hsp70 mechanism of action.
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Mores, fault and fides: are these acceptable criteria when income tax deductions are claimed
- Authors: Swanepoel, Marius G
- Date: 2007
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:889 , http://hdl.handle.net/10962/d1001643
- Description: The two “pillars” on which taxable income is based are the definition of “gross income” in section 1 of the Income Tax Act, 58 of 1962, and the “general deduction formula” comprising the preamble to section 11, section 11(a) and section 23(g) of the Act. Many of the terms used in these sections are not defined in the Income Tax Act. Case law in relation to these sections reveals that morality issues, the negligence of taxpayers and the good faith of taxpayers have from time to time been treated as relevant considerations by the courts, both abroad and in South Africa, in allowing or disallowing deductions from the gross income of taxpayers. In some instances this occurred apparently unwittingly. In other instances, earlier decisions were followed without a thorough consideration of the correctness of the underlying reasoning or of the criteria which were applied in the earlier decisions. In relation to the definition of “gross income”, however, fides, mores and fault have not been a consideration. In CIR v Delagoa Bay Cigarette Co Ltd 1918 TPD 391 Bristowe, J stated: “I do not think it is material for the purpose of this case whether the business carried on by the company is legal or illegal.” There were a number of cases heard in relation to income from illegal activities (for example, COT v G, 1981 (4) SA 167 (ZA), 43 SATC 159, and ITC 291, 7 SATC 335, which related to the misappropriation of funds, ITC 1545, 54 SATC 464, which dealt with the proceeds of the sale of stolen diamonds and ITC 1624, 59 SATC 373, which dealt with overcharging customers). In these cases, the question turned on whether or not the amounts were received by the taxpayers for their own benefit and therefore to be included in gross income, or whether the taxpayers incurred a concomitant liability to repay the amounts, and did not involve the question of fides, mores or fault. The research concludes that, providing an even-handed approach is applied to both income and expense considerations, fides and mores may continue to play a role as a useful yardstick in this context. However, that fault, particularly the causal negligence of taxpayers in the process of sustaining a loss or incurring expenditure whilst conducting their income generating operations, has effectively been jettisoned as an irrelevant consideration, is a salutary development which has contributed to legal certainty.
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Networking: enabling professional development and institutionalisation of environmental education courses in Southern Africa
- Authors: Lupele, Justin Kalaba
- Date: 2007
- Subjects: SADC Regional Environmental Education Programme Education -- Africa, Southern Environmental education -- Africa, Southern Environmental education -- Study and teaching -- Africa, Southern
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1678 , http://hdl.handle.net/10962/d1003561
- Description: This study was aimed at understanding how networking can enable or constrain professional development and institutionalisation of environmental education courses in southern Africa in the context of the Course Development Network (CDN), a project of the Southern Africa Development Community Regional Environmental Education Programme (SADC REEP). The study involved 12 institutions (each institution was represented in the CDN by a staff member) in eight SADC member states. It was contextualized through a review of social, political, environmental and educational developments in southern Africa, with specific reference to regionalization processes, as the SADC REEF is constituted under this post-colonial political framework. Relational philosophy informed the research process and methodology. The philosophy underpinned three distinct, yet related theoretical perspectives namely: critical realism, which provided the ontological perspectives of the study; Actor Network Theory; and Community of Practice, which provided the epistemological perspectives. Data was generated during a 33-month period in southern Africa and 12 months in the United Kingdom (and on a one week visit to Italy). During a 12 month Split Site Commonwealth Scholarship award, tenable at Manchester Metropolitan University in the United Kingdom, I studied the Environment and School Initiative (ENSI) and the Sustainability Education for European Primary Schools (SEEPS), to examine whether the same mechanisms that made them successful would apply to the CDN in the context of southern Africa. While these two case studies provided useful insight into the relationship between networking, professional development and institutionalization of environmental education programmes, they were not the main focus of the research. Data analysis was mainly through inductive, abductive and retroductive modes of inference. Inductive data analysis was done by means of Nvivo – a computer software package used for qualitative data analysis. The software aided in revealing features and relationships in the data in more depth as it allowed flexibility in working with data. Abduction is the interpretation of a phenomenon by means of a conceptual framework. In this study, I used Actor Network Theory (ANT) (Latour & Woolgar, 1979; Callon, 1986) and Community of Practice (COP) (Lave, 1988; Lave & Wenger, 1991; Fullan, 2003) as analytical conceptual frameworks to probe networking and professional development respectively. Data on institutionalisation of environmental education courses was analysed by means of retroductive mode of inference, which is a thought operation that enables the understanding of social reality beyond what is empirically observable or experienced. This study reveals that there were a number of necessary (internal) and contingent (external) factors that enabled or constrained networking, professional development and institutionalisation of environmental education courses in the context of the CDN. The key factors included existing cultural capital, donor political economy, power relations, poverty related factors and social transformation trends. The study found that relational approaches and the use of three relational theoretical lenses provided a broader lens which enabled this study to identify different dynamics, greater ontological depth and understanding of the relational dynamics and relations at play in the CDN beyond the participants' experience and observable events. The study also contends that networking can provide a support structure for social transformation and change in environmental education.
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Nguni fermented foods: working with indigenous knowledge in the Life Sciences: a case study
- Authors: Hanisi, Nosipho
- Date: 2007
- Subjects: Life sciences -- Study and teaching (Secondary) -- South Africa -- Case studies Environmental education -- South Africa -- Case studies Fermented foods -- Case studies Fermentation Indigenous peoples -- Case studies Nguni (African people) -- Social life and customs. Xhosa (African people) -- Social life and customs. Ethnoscience
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1957 , http://hdl.handle.net/10962/d1008372
- Description: This study examines learning interactions around indigenous ways of knowing associated with fermented grain foods (the making of umqombothi) and the concept of alcoholic fermentation in the Grade 11 Life Sciences curriculum. As an environmental education study it also investigates the cultural significances of the fermented grain food and how learners might make better lifestyle choices. The inclusion of indigenous ways of knowing in the Life Sciences curriculum (FET band) created spaces and opportunities for the use of both knowledge's in sociocultural context and the structured propositions of the learning area in order to construct knowledge. This stimulated learners' understanding of fermentation and also led to a valuing of social context as well as the cultural capital embedded in the indigenous ways of knowing. The study suggests that parental involvement contributed to this valuing of intergenerational ways of knowing. Learners also deliberated how colonial interpretations of Nguni culture and the religious beliefs of Christians had served to marginalise and foster a widening urban rejection of isiXhosa cultural practices related to fermented foods. In their learning and discussion, learners developed new insights and respect for isiXhosa fermentation practices (ukudidiyela) that bring out the food value and nutrition in the grain. The data illustrates that lesson activity that drew on relevant Learning Outcomes and Assessment Standards to integrate Indigenous Knowledge practices in a Life Sciences learning programme, served to enhance learner understanding of alcoholic fermentation. They also document a revaluing of cultural heritage and learners bringing up the problem of alcohol abuse in the community. Curriculum work with Indigenous Knowledge thus not only assisted learners to grasp the science but to use this alongside a valued cultural knowledge capital to deliberate and act on a local concern.
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Occult forces -- lived identities: witchcraft, spirit possession and cosmology amongst the Mayeyi of Namibia's Caprivi Strip
- Authors: Von Maltitz, Emil Arthur
- Date: 2007
- Subjects: Yeye (African people) , Yeye (African people) -- Namibia -- History , Occultism -- Namibia , Witchcraft -- Namibia , Spirit possession -- Namibia , Cosmology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2121 , http://hdl.handle.net/10962/d1013279
- Description: Around Africa there seems to be an increasing disillusion with 'development', seen under the rubric of teleological 'progress', which is touted by post-colonial governments as being the cure for Africa's ailments and woes. Numerous authors have pointed out that this local disillusion, and the attempt to manage the inequities that arise through development and modernity, can be seen to be understood and acted upon by local peoples through the idiom of witchcraft beliefs and fears (see Geschiere & Fisiy 2001; Geschiere 1997; Nyamnjoh 2001; Comaroff & Comaroff 1993; Ashforth 2005) and spirit possession nanatives (see Luig 1999; Gezon 1999), or more simply, occult beliefs and praxis (Moore & Sanders 2001). The majority of the Mayeyi of Namibia's Eastern Caprivi perceive that development is the only way their regiOn and people can survive and succeed in a modernising world. At ~he same time there is also a seeming reluctance to move towards perceiving witchcraft as a means of accumulation (contra Geschiere 1997). This notion of the 'witchcraft of wealth' is emerging, but for the most part witches are seen as the enemies of development, while spirit possession narratives speak to the desire for development and of the identity of the group vis-a-vis the rest of the world. The thesis presented argues that, although modernity orientated analyses enable occult belief to be used as a lens through which to 1..mderstand 'modernity's malcontents' (Comaroff & Comaroff 1993), they can only go so far in explaining the intricacies of witchcraft and spirit possession beliefs themselves. The dissertation argues that one should return to the analysis of the cosmological underpinnings of witchcraft belief and spirit possession, taken together as complementary phenomena, in seeking to understand the domain of the occult. By doing so the thesis argues that a more comprehensive anthropological understanding is obtained of occult belief and practice, the ways in which the domain of the occult is constituted and the ways in which it is a reflection or commentary on a changing world.
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Opportunities for eco-efficiency at Summerpride Foods Ltd.: a pineapple processing factory
- Authors: Venters, Bruce Russell Ainsley
- Date: 2007
- Subjects: Summerpride Foods Ltd. (South Africa) Environmental protection -- South Africa Industries -- Environmental aspects -- South Africa Pineapple industry -- South Africa Environmental policy -- South Africa Sustainable development -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:787 , http://hdl.handle.net/10962/d1003908
- Description: International awareness and demands for the protection of the environment by the public on industry has only been pushed into the limelight in the past couple of decades. Prior to this it could be argued that it was accepted that environmental protection and economic development were at odds. However it has since been recognised that there is a need to achieve environmental sustainability, the concept of which was released in the 1987 Brundtland Report released by the United Nations. There are a number of ways that industry can reduce its impact on the environment and thus help reach this goal. While some advocated that stricter legislation would result in greater innovation by industry in “cleaning-up” its act, such as the Porter Hypothesis, there were also a number of new concepts and voluntary industry codes being developed. These new practices and codes have been promoted by organisations such as the International Chamber of Commerce and include technological improvements within organisations and improved resource productivity. The aim of this case study research was to find out what the environmental policy and related performance of Summerpride Foods Ltd, a pineapple processing factory in East London was and does an understanding of its environmental performance provide insights for improved efficiency. This involved the identification and analysis of what resources were used during the processing of pineapples as well as making recommendations that would result in increased efficiencies of their use. Due to the number of resources identified, only the use of water and coal which were ranked as having the highest impact were investigated further. The literature review showed that there are industry moves to applying cleaner production and eco-efficiency concepts as a means to attaining environmental sustainability. There are a number of voluntary environmental management system standards and codes that organisations can subscribe to with most probably the ISO 14001 standard being the most internationally recognised. There are many benefits to organisations adopting such standards. The use of lifecycle assessments is a useful tool that can be used to assess the environmental impact of a product through its entire life and thus enable one to identify all resources used and their impact, as well as to provide the information required to quantify areas where the greatest improvements can be made. The results of this research showed that at the start of the study, there was no formal environmental policy in place at Summerpride Foods Ltd and that this was starting to become a requirement with some customers. The detailed results which focused on water and coal usage showed that current operating methods do not recognise the importance of any wastage and that there are a number of changes that could be made that would not only result in better efficiency of use but would also result in substantial financial savings to the organisation. Summerpride Foods Ltd currently has a number of systems in place that help reduce its impact on the environment but these are not formally recorded. Summerpride Foods Ltd should adopt the principles of eco-efficiency and record all systems that impact on the environment. This would be the first step to attaining a formal environmental management system accreditation which due the increasing competitiveness of the international market in which Summerpride Foods Ltd operates, would give it a degree of advantage over those competing pineapples processing factories that do not have such accreditation.
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Opportunity and constraint : historicity, hybridity and notions of cultural identity among farm workers in the Sundays River Valley
- Authors: Connor, Teresa Kathleen
- Date: 2007
- Subjects: Agricultural laborers -- South Africa -- Relocation Addo Elephant National Park (South Africa) Xhosa (African people) -- South Africa -- Eastern Cape -- Ethnic identity Forced migration -- South Africa -- Eastern Cape Land settlement -- South Africa -- Government policy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2117 , http://hdl.handle.net/10962/d1008367
- Description: This thesis focuses on relationships of opportunity and constraint among farm workers in the Sundays River Valley (SRV), Eastern Cape Province. Relationships of 'constraint' include those experiences of displacement and forced removal and war, including forced removals by the apartheid state in 1960 and 1970. Relationships of 'opportunity' include the ways in which residents in the SRV have contested their experiences of upheaval and domination, and the formation of a regional sense of place and belonging/ investigate how farm workers actually draw elements of locality and identity from their experiences of upheaval, and how displacement bolsters feelings of belonging and place. Instead of viewing displacement as a once-off experience, this thesis investigates displacement in historical terms, as a long-term, 'serial' experience of human movement, which is continued in the present- specifically through the creation of the Greater Addo Elephant National Park. I concentrate on developing a spatialised and cultural notion of movemenUplacement. 'Place' is investigated as a term that refers to rather indeterminate feelings of nostalgia, memory and identity, which depend on a particular connection to territory (ie: 'space'). I emphasise that elements of place in the SRV are drawn from and expressed along dualistic lines, which juxtapose situations of opportunity and constraint. In this way, farm workers' sense of connection to farms and ancestral territory in the SRV depends on their experiences of stable residency and work on farms, as well as their memories of removal from land in the area. I emphasise that those elements of conservatism (expressed as 'tradition' and Redness) among Xhosa-speaking farm workers are indications of a certain hybridity of identity in the region, which depend on differentiation from other groups (such as so-called 'coloured' farm workers and 'white' farmers), as well as associations between these groups. This thesis lays emphasis upon those less visible and definable 'identities' in the Eastern Cape Province, specifically by shifting focus away from the exhomeland states of the Ciskei and Transkei, to more marginal expressions of identity and change (among farm workers) in the Province. I point out that labourers cannot solely be defined by their positions as farm workers, but by their place and sense of cultural belonging in the area. In this sense, I use the idea of work as a loaded concept that can comment on a range of cultural attitudes towards belonging and place, and which is firmly embedded in the private lives of labourers - beyond their simple socio-economic conditions of farm work. I use Bourdieu's conception of habitus and doxa to define work as a set of dispositions that have been historicised and internalised by workers to such an extent, that relationships of domination are sometimes inadvertently obscured through their apparent 'naturalness'. Moreover, I point out that work can be related to ritualised action in the SRV through the use of performance and practice-based anthropological theory. Both work and ritual are symbolic actions, and are sites of struggle within which workers express themselves dualistically. Rituals, specifically, are dramatic events that combine disharmonious and harmonious social processes - juxtaposing the powerlessness of workers (on farms), and the deep sense of belonging and place in the SRV. I argue that the deep historical connections in the SRV have largely been ignored by conservationists in the drive to establish new protected zones (such as the Greater Addo Elephant National Park), and that a new model of shared conservation management is needed for this Park.
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Particle precipitation effects on the South African ionosphere
- Authors: Sibanda, Patrick
- Date: 2007
- Subjects: Ionosphere -- South Africa , Precipitation (Chemistry) -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5481 , http://hdl.handle.net/10962/d1005267 , Ionosphere -- South Africa , Precipitation (Chemistry) -- South Africa
- Description: Particle precipitation involves the injection of energetic particles into the ionosphere which could increase the ionisation and conductivity of the upper atmosphere. The goal of this study was to examine the ionospheric response and changes due to particle precipitation in the region over South Africa, using a combination of groundbased and satellite instruments. Particle precipitation events were identified from satellite particle flux measurements of the Defence Meteorological Satellite Program (DMSP). Comprehensive studies were done on the events of 5 April, 2000 and 7 October, 2000. Analysis of the data from the satellite instruments indicates that no particle precipitation was observed over the South African region during these events and that it is unlikely to occur during other such events. To validate the data, methods and tools used in this study, precipitation in the South Atlantic anomaly (SAA) region is used. Satellite ion density measurements revealed that strong density enhancements occurred over the SAA region at satellite altitudes during the precipitation events, but this did not occur in the South African region. The measurements also revealed how the ionisation enhancements in the SAA region correlated with geomagnetic and solar activities. Particle precipitation and convective electric fields are two major magnetospheric energy sources to the upper atmosphere in the auroral and the SAA regions. These increase dramatically during geomagnetic storms and can disturb thermospheric circulation in the atmosphere and alter the rates of production and recombination of the ionised species. Ionosonde observations at Grahamstown, South Africa (33.30S, 26.50E), provided the data to build a picture of the response of the ionosphere over the South African region to particle precipitation during the precipitation events. This analysis showed that, within the confines of the available data, no direct connections between particle precipitation events and disturbances in the ionosphere over this region were revealed.
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Passing the spear : a grounded theory study of the influence of family business value sets on succession planning in black family-owned businesses
- Authors: Musengi, Sandra
- Date: 2007
- Subjects: Grounded theory Family-owned business enterprises Family-owned business enterprises -- Succession Family-owned business enterprises -- Management Business enterprises, Black Business planning
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1192 , http://hdl.handle.net/10962/d1007056
- Description: Literature suggests that a small number of family businesses are able to make the transition from the founder to other family members with a common reason cited being the lack of planning. This study aims to build understanding of leadership succession in family businesses by focusing on the influence of a founder's family business value set on the succession planning process in Black family-owned businesses. Using the Strauss and Corbin (1990) grounded theory method, this study develops a theory of succession planning of Black familyowned businesses labelled Passing the Spear which is comprised of three stages based on an analysis of 21 qualitative interviews. The Spear was an analogy used to represent both the values of the founder and the family business, thus in Passing the Spear, founders where essentially performing a dual transfer of their values and leadership to the successor. The implementation of the process Passing the Spear was influenced by the family business value set of the founder, which in this study, were labelled as Traditional, Progressive, and Transitional. These value sets were distinguished by their behaviour regarding their choice of successor where founders with a traditional value set exhibited gatekeeping behaviour, while the behaviour of founders with a progressive value set was labelled navigating, and finally, founders with a transitional value set demonstrated behaviour labelled exploring. Furthermore, it was found that after the successor had been chosen, founders appeared to follow a generic succession planning process, however, the ease and timing of implementation was influenced by the family business context, evidence of being proactive and the degree of family business resilience. The process of Passing the Spear comprised of three stages of (a) Showing the spear where the founder's focus is on the induction and socialization of the successor using the strategies of bringing the successor into the family business and managing the family-business interface using relationships; (b) Explaining the spear entailed founders using the strategies of sharing knowledge and teaching the successors about the family business; and ( c) Sharing the spear was where founders focused on empowering the successors by implementing strategies of sharing responsibilities and learning from the successor.The process provides insights into the influence of family business values on the succession planning process and can be useful for founders of Black family-owned businesses in planning for succession in their businesses. In addition, the study provides another perspective of succession planning and offers a contribution to the literature for understanding succession in Black family-owned businesses.
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Past trauma, anxious future a case-based evaluation of the Ehlers and Clark model for PTSD applied in Africa
- Authors: Van der Linde, Francois
- Date: 2007
- Subjects: Cognitive therapy Post-traumatic stress disorder -- Africa Rape trauma syndrome -- Treatment -- Africa Rape victims -- Africa Anxiety -- Treatment Depression, Mental -- Treatment Post-traumatic stress disorder -- Patients Case studies
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3075 , http://hdl.handle.net/10962/d1002584
- Description: This research report documents the therapeutic intervention undertaken with a 23-year-old Swazi rape victim. The format of this research report takes the form of a case study that follows the principles proposed by Fishman (2005). Its aim is to document the treatment process of an individual of African decent in order to establish whether the treatment model can be effective in clinical settings and in contexts and cultural settings different from that in which it was developed. The Ehlers and Clark (2000) cognitive therapy model for post-traumatic stress disorder (PTSD) was utilised to assess, conceptualise, and treat the case. The client entered therapy three years after being raped for a third time. The case formulation identified factors maintaining the disorder as well as how other traumatic and abusive events earlier in her life influenced her response to the rapes. Data consisted off audio-tape recordings and detailed written synopses of each assessment and therapy session, psychometric measurement instruments and self-report scales completed throughout the intervention, material written by the client, and a research interview conducted by an independent party. She was treated for PTSD and comorbid depression over a period of five months in accordance with the principles described by Ehlers and Clark and a narrative of the treatment process was written. The case narrative in conjunction with quantitative data suggested that this model assisted the client in initiating a healing process. As such the model was found to be both effective and transportable to an African context. Various points of discussion are highlighted, including the challenges of working with PTSD and comorbid major depression, the client-therapist relationship, and that a client and therapist from different cultures, backgrounds, and with different home languages can work together effectively using the Ehlers and Clark model.
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Pharmaceutical analysis and quality of complementary medicines : sceletium and associated products
- Authors: Patnala, Satya Siva Rama Ranganath Srinivas
- Date: 2007
- Subjects: Alternative medicine , Herbs -- Therapeutic use
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3872 , http://hdl.handle.net/10962/d1018263
- Description: There has been an upsurge in the use of Complementary and Alternate Medicines (CAMs) in both developed and developing countries. Although herbal medicines have been in use for many centuries, their quality, safety and efficacy are still of major concern. Many countries are in the process of integrating CAMs into conventional health care systems based on the knowledge and use of traditional medicines. The quality control (QC) of herbal products usually presents a formidable analytical challenge in view of the complexity of the constituents in plant material and the commercial non-availability of appropriate qualified reference standards. Sceletium, a genus belonging to the family Aizoaceae, has been reported to contain psychoactive alkaloids, specifically mesembrine, mesembrenone, mesembrenol and some other related alkaloids. Sceletium is marketed as dried plant powder and as phyto-pharmaceutical dosage forms. Sceletium products and plant material marketed through health shops and on the internet are associated with unjustified claims of specific therapeutic efficacy and may be of dubious quality. Validated analytical methods to estimate Sceletium alkaloids have not previously been reported in the scientific literature and the available methods have focused only on qualitative estimation. Furthermore, since appropriate markers were not commercially available for use as reference standards, a primary objective of this study was to isolate relevant compounds, qualify them as reference standards which could be applied to develop appropriate validated qualitative and quantitative analytical methods for fingerprinting and assay of Sceletium plant material and dosage forms. The alkaloidal markers mesembrine, mesembrenone and ∆⁷ mesembrenone were isolated by solvent extraction and chromatography from dried plant material. Mesembranol and epimesembranol were synthesised by hydrogenation of the isolated mesembrine using the catalyst platinum (IV) oxide and then further purified by semi-preparative column chromatography. All compounds were subjected to analysis by ¹H, ¹³C, 2-D nuclear magnetic resonance and liquid chromatography-tandem mass spectroscopy. Mesembrine was converted to hydrochloride crystals and mesembranol was isolated as crystals from the hydrogenation reaction mass. These compounds were analysed and characterised by X-ray crystallography. A relatively simple HPLC method for the separation and quantitative analysis of five relevant alkaloidal components in Sceletium was developed and validated. The method was applied to determine the alkaloids in plant material and dosage forms containing Sceletium. An LCMS method developed during the study provided accurate identification of the five relevant Sceletium alkaloids. The method was applied for the quantitative analysis and QC of Sceletium plant material and its dosage forms. This LCMS method was found to efficiently ionize the relevant alkaloidal markers in order to facilitate their detection, identification and quantification in Sceletium plant material as well as for the assay and QC of dosage forms containing Sceletium. The chemotaxonomy of some Sceletium species and commercially available Sceletium dosage forms were successfully studied by the LCMS method. The HPLC and LCMS methods were also used to monitor the bio-conversion of some of the alkaloids while processing the plant material as per traditional method of fermentation. Additionally a high resolution CZE method was developed for the separation of several Sceletium alkaloids in relatively short analysis times. This analytical method was used successfully to fingerprint the alkaloids and quantify mesembrine in Sceletium and its products. Sceletium species grown under varying conditions at different locations, when analyzed, showed major differences in their composition of alkaloids and an enormous difference was found to exist between the various species with respect to the presence and content of alkaloids. Sceletium and its products marketed through health shops and the internet may thus have problems with respect to the quality and related therapeutic efficacy. The QC of Sceletium presents a formidable challenge as Sceletium plants and products contain a complex mixture of compounds. The work presented herein contributes to a growing body of scientific knowledge to improve the QC standards of herbal medicines and also to provide vital information regarding the selection of plant species and information on the specific alkaloidal constituents to the cultivators of Sceletium and the manufacturers of its products.
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Phthalocyanines : photochemical, electrochemical and biomimetic catalytic behaviour
- Authors: Sehlotho, Nthapo
- Date: 2007
- Subjects: Phthalocyanines Photochemistry Electrochemistry Biomimetics Oxidation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4336 , http://hdl.handle.net/10962/d1004997
- Description: This thesis explored use of metallophthalocyanines as electrocatalysts towards thiol and thiocyanate oxidation, nitrosothiol decomposition and reduction of oxygen, as well as biomimetic and photo-catalysts of cyclohexene oxidation. 2-mercaptoethanol (2-ME), L-cysteine (CYS) and reduced glutathione (GSH) thiols were oxidized on cobalt tetra ethoxythiophene and cobalt tetra phenoxy pyrrole phthalocyanine modified glassy carbon electrodes, whose catalytic activity was found to depend on pH, film thickness and method of electrode modification. Oxidation of thiocyanate (SCN-), CYS and 2-ME was catalyzed by a selfassembled monolayer of cobalt tetraethoxythiophene Thiocyanate oxidation occurred via two electron transfer, whereas that of CYS and 2-ME required 1 electron. The oxidations of SCN- and 2-ME were catalyzed by ring based processes, while CYS was catalyzed by both Co[superscript III]/Co[superscript II] process and ring-based processes. Oxidation of GSH and 2-ME was conducted on screen printed graphite electrodes modified with cobalt phthalocyanine. Activity depended on method of electrode modification and CoPc % composition. Decomposition of Snitrosoglutathione occurred in the presence of copper ions and NaBH[subscript 4]. Reduced and oxidized glutathione were detected as products using cobalt phthalocyanine adsorbed on an ordinary pyrolytic graphite electrode. Reduction of oxygen was electro-catalyzed by adsorbed manganese phthalocyanine complexes on glassy carbon electrodes. FePc, FePc(Cl)[subscript 16], CoPc and CoPc substituted with phenoxypyrrole and ethoxythiophene ligands were also used as electro-catalysts. Oxygen reduction occurred via two electron transfer in acidic and neutral media forming hydrogen peroxide, while water was formed in basic media via four electron transfer. Cyclohexene oxidation using tert-butylhydroperoxide or chloroperoxy benzoic acid as oxidants in the presence of FePc, FePc(Cl)[subscript 16] and CoPc formed cyclohexene oxide, 2-cyclohexen-1-ol, 2- cyclohexen-1-one and adipic acid. Product selectivity depended on the nature of catalyst and oxidant. The FePc(Cl)[subscript 16] catalyst was transformed into a µ-oxo dimer during the oxidation process while M[superscript III]Pc intermediates were formed with Co[superscript II]Pc and Fe[superscript II]Pc catalysts. Cyclohexene photooxidation catalyzed by zinc phthalocyanine using either red or white light formed 2-cyclohexen-1-one, 2-cyclohexen-1-ol, transcyclohexane diol, cyclohexene oxide and cyclohexene hydroperoxide via singlet oxygen and radical mechanisms. Product yields depended on the light wavelength and intensity, solvent, irradiation time and the rate of photodegradation of the catalyst.
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Population structure, growth and recruitment of two exploited infralittoral molluscs (Haliotis midae and Turbo sarmaticus) along the south east coast, South Africa
- Authors: Proudfoot, Lee-Anne
- Date: 2007
- Subjects: Abalones -- South Africa , Abalones -- Growth -- South Africa , Turbinidae -- South Africa , Mollusks -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5744 , http://hdl.handle.net/10962/d1005430 , Abalones -- South Africa , Abalones -- Growth -- South Africa , Turbinidae -- South Africa , Mollusks -- South Africa
- Description: The two most frequently exploited species along the south east coast of South Africa are the gastropods, Haliotis midae (abalone) and Turbo sarmaticus (alikreukel). H. midae is a high valued commercial species, and suffers intense levels of illegal fishing. T. sarmaticus however, has no commercial value but is the preferred food item for impoverished subsistence communities. Owing to the fact that no legal commercial fishery exists for either species along the south coast, very few studies have been undertaken, especially in the heavily exploited infralittoral. Infralittoral size frequency distributions for both species revealed significant variation in density and size among sites of varying exploitation pressure. Densities ranged between 0 – 2.23 m⁻² (H. midae) and 0.03 – 4.93 m⁻² (T. sarmaticus) and maximum shell lengths ranged from 49.4 – 153.5 mm (H. midae) and 28.3 – 104.4 mm (T. sarmaticus). Relatively high densities and large sizes were found in marine reserves and secluded areas, and low densities and small sizes at sites near to large population centres and within the former Ciskei homeland region. Mean size of the largest 10% of the population, total density and sexually mature density were significantly related to exploitation predictors for both species. In addition, densities of H. midae juveniles were significantly related to exploitation predictors, suggesting that recruitment may be suppressed at the most exploited sites. Exploitation of T. sarmaticus tended to be localized with refuge and subtidal populations persisting. H. midae exploitation was however, far more extensive and intense. Growth of H. midae was investigated using three methods; mark-recapture, cohort analysis and growth banding analysis at Kowie Rocks, Port Alfred. The most useful of these methods for determining growth was a new technique described for growth banding analysis; which was validated using cohort analysis and measurements of shells of known age. This technique was less time consuming and labour intensive than previously described methods. Abalone growth was best described by the Schnute (1981) growth function. Systematic geographic variation in growth was observed for 10 sites along the South African coastline. Significant differences in growth among sites existed for animals between 0-4 years (P < 0.0001) and 4-6 years (P < 0.0001), and in the mean maximum sizes attained (P < 0.001). In general, abalone from the south east/east coast were found to have faster growth rates, smaller mean maximum sizes and attained sexual maturity earlier than those along the south west/ west coast. Haliotis midae recruit and juvenile densities were found to differ significantly among sites of varying exploitation pressure (P < 0.0001) and among months for recruit densities (P < 0.001). Exploited sites had low recruit and juvenile densities compared to unexploited sites and peak recruitment occurred during October/ November 2005. Recruit densities were significantly related to infralittoral adult densities during two of the three sampling months (P<0.05), when recruitment was low. No relationship was observed during the period of high recruitment, with all sites receiving high recruit densities. It was concluded that variation in recruit densities was the result of a combination of both density-dependent relationships (i.e. local spawner density and temporal variability in recruitment intensity) and the possible dispersal capabilities of H. midae. In addition, it was concluded that at present recruitment overfishing was not occurring along the south east coast. Post-recruitment mortality rates were variable but relatively constant, with hypothetical percentage survival and density curves revealing high rates and similar mortality curves among sites. Variation in juvenile densities was consequently a result of initial recruit densities and not variation in post-recruitment mortality. T. sarmaticus populations were found to be regionally sustainable and persisted along the south east coast due to adjacent intertidal and subtidal refuge populations. However, H. midae populations are becoming decimated along the south east coast. From the information obtained in this study new management proposals were suggested and discussed, such as closed areas and region-based management fisheries together with stock enhancement. These suggestions may prove to be feasible alternatives to present management strategies.
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