Antibacterial and phytochemical studies of selected South African honeys on clinical isolates of Helicobacter pylori
- Authors: Manyi-Loh, Christy E
- Date: 2012
- Subjects: Helicobacter pylori , Honey--South Africa , Drug resistance in microorganisms , Bacterial diseases , Honey -- Therapeutic use , Helicobacter pylori infections , Traditional medicine -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Microbiology)
- Identifier: vital:11240 , http://hdl.handle.net/10353/d1001056 , Helicobacter pylori , Honey--South Africa , Drug resistance in microorganisms , Bacterial diseases , Honey -- Therapeutic use , Helicobacter pylori infections , Traditional medicine -- South Africa -- Eastern Cape
- Description: Infection with Helicobacter pylori has been associated with the pathogenesis of numerous stomach and gastroduodenal diseases that pose threats to public health. Eradicaftion of this pathogen is a global challenge due to its alarming rate of multidrug resistance. Consequently, to find an alternative treatment, the search is increasingly focused on new antimicrobial product from natural sources including honey. Honey has been used as medicine in several cultures since ancient time due to its enormous biomedical activities. Its beneficial qualities have been endorsed to its antimicrobial, antioxidant, anti-inflammatory properties added to its phytocomponents. In this study, the anti-H. pylori activity of South African honeys and their solvent extracts as well as the phytochemicals present in the two most active honeys were evaluated. Agar well diffusion test was used to investigate the antimicrobial activity of six honey varieties obtained from different locations in the country. Subsequently, the honeys were extracted with four organic solvents viz n-hexane, diethyl ether, chloroform and ethyl acetate employed in order of increasing polarity. The antibacterial activity of the different solvent extracts of each honey was evaluated by agar well diffusion; broth micro dilution and time kill assays. Different chromatographic techniques (Thin layer & column chromatography) were employed to enumerate the phytochemical constituents in the most active solvent extracts of Pure Honey (PH) and Champagne Royal Train (CRT); and were identified by gas-chromatography linked mass-spectrometry. Linalool pure compound was equally evaluated for anti-H. pylori activity in a bid to trace the antibacterial agent among the variety of compounds identified. Data were analyzed by One-way ANOVA test at 95% confidence interval. Crude honeys and their solvent extracts demonstrated potent anti-H. pylori activity with zone diameter that ranged from [16.0mm (crude) to 22.2mm (extract)] and percentage susceptibilities of test isolates between 73.3% (crude) and 93.3% (extract). The chloroform extracts of PH and CRT were most active with MIC50 in the ranges 0.01- viii 10%v/v and 0.625-10%v/v respectively, not significantly different from amoxicillin (P> 0.05); and efficient bactericidal activity (100% bacterial cells killed) at 1/2MIC and 4xMIC over different time intervals, 36-72hrs and 18-72hrs respectively. The appearance of bands on the thin layer chromatography (TLC) chromatogram spotted with the chloroform extracts of PH and CRT; and developed with hexane: ethyl acetate: acetic acid (HEA) and methanol: acetic acid: water (MAAW) solvent systems indicated the presence of compounds. Purification of the compounds contained in these extracts over silica gel column yielded numerous fractions which were evaluated for antibacterial activity and purity. PHF5 was the most active fraction with a mean MIC50 value of 1.25mg/mL. Volatile compounds belonging to different known chemical families in honey were identified in all the active fractions obtained from PH. Conversely, only four compounds were identified in the active fractions obtained from CRT hence the non volatile constituents could be of prime relevance with respect to antibacterial activity of this honey. Of novelty was the presence of thiophene and N-methyl-D3-azirdine compounds, essential precursors used for the synthesis of natural products and pharmaceuticals with vital biomedical properties. Linalool demonstrated potent inhibitory (MIC95, 0.002- 0.0313mg/mL) and bactericidal activity (0.0039-0.313mg/mL) against the test isolates. On the other hand, a significant difference was recorded (P < 0.05) in comparing the activity of linalool compound to the fractions. PH could serve as a good economic source of bioactive compounds which could be employed as template for the synthesis of novel anti-H. pylori drugs. However, further studies are needed to determine the non volatile active ingredients in PH and CRT as well as toxicological testing
- Full Text:
- Date Issued: 2012
Assessing linkages between local ecological knowledge, HIV/AIDS and the commercialisation of natural resources across Southern Africa
- Authors: Weyer, Dylan James
- Date: 2012
- Subjects: AIDS (Disease) -- Africa, Southern , HIV infections -- Africa, Southern , Natural resources -- Management -- Africa, Southern , Traditional ecological knowledge -- Africa, Southern , Households -- Economic aspects -- Africa, Southern , Poverty -- Environmental aspects -- Africa, Southern , Ecology -- Economic aspects -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4769 , http://hdl.handle.net/10962/d1007180 , AIDS (Disease) -- Africa, Southern , HIV infections -- Africa, Southern , Natural resources -- Management -- Africa, Southern , Traditional ecological knowledge -- Africa, Southern , Households -- Economic aspects -- Africa, Southern , Poverty -- Environmental aspects -- Africa, Southern , Ecology -- Economic aspects -- Africa, Southern
- Description: That natural resources (NRs) are important to those experiencing adversity, and, especially, vulnerability associated with HIV/AIDS, is well documented, particularly with respect to food and energy security. What is unclear is where HIV/AIDS ranks in terms of its significance in comparison to other household shocks, the role local ecological knowledge may (LEK) play in households' response to shock, a propos the types of coping strategies that are employed. Consequently, this research aims to bridge the knowledge gap between HIV/AIDS and the degree to which it is contributing to the expansion of NR commercialisation and to explore the unknowns surrounding the influence of LEK on people's choice of coping strategy. A two phase study was designed to provide quantitative rigour with qualitative depth. Phase one was an extensive, rapid survey of NR traders within urban and rural settings in five southern Africa countries. The principle objective was to profile the trade, the livelihoods of those involved and their reasons for entering the trade, to ultimately establish to what degree HIV/AIDS may have been a catalyst for this. Almost one third of the sample entered the trade in response to illness and/or death in their households, with 80% of deaths being of breadwinners. The findings illustrated considerable dependence on the sale of NRs; for almost 60% of the sample it was their household's only source of income. There was evidently increased blurring of the lines between rural and urban NR use with a greater diversity of products being traded in urban areas. Phase two involved in-depth interviews and work with a smaller sample at two sites selected based on the findings from the first phase. It incorporated three groups of households; non-trading, inexperienced trading and experienced trading households. Key areas of focus were household shocks, coping strategies employed in response to these and the role LEK may be playing in the choice of coping strategies. Within a two year period, 95% of households registered at least one shock, of which 80% recorded AIDS-related proxy shocks. Non-trading households were significantly worse-off in this regard, while in the case of non-AIDS proxy shocks, there was no such difference between groups. The most frequently employed coping strategy was the consumption and sale of NRs and was of particular importance when households were faced with AIDS proxy shocks. Trading households emerged as having superior levels of LEK in comparison to non-trading households, even for non-traded NRs, suggesting that prior LEK of NRs opened up opportunities to trade in NR as a coping strategy. Further inspection of the latter group however revealed that the portion of non-trading households who traded on a very ad hoc basis actually had comparable levels of LEK to the trading households. Despite the ad hoc trading households' vulnerable state and their disproportionately high level of AIDS proxy measures, they had at their disposal, sufficient LEK to unlock certain key coping strategies, namely the NR trade. In this sense there are apparent linkages between LEK, HIV/AIDS and the expansion of the commercialisation of NRs.
- Full Text:
- Date Issued: 2012
Butterfly bones
- Authors: Gowans, Elisabeth
- Date: 2012
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5986 , http://hdl.handle.net/10962/d1015723
- Description: Butterfly Bones is a lyrical sequence of poetry and prose poems organised to trace a rhythmical, emotional pattern of experience. In its subject matter, the sequence presents an implied personal narrative recording the author's grief in the ten months following her mother's death in January 2011. It presents brief, vivid scenes from the poet's daily life in a rural village outside Grahamstown, and observations of creatures and her natural surroundings, which serve as a counterpoint to her grief. It can also be read as a meditation on writing, solitude and the possibilities of poetry.
- Full Text:
- Date Issued: 2012
Case study of the educational experiences of four teenage mothers in two high schools in the Buffalo City Metropole
- Authors: Adams, Hermie E
- Date: 2012
- Subjects: Teenage girls -- Sexual behavior -- South Africa -- Eastern Cape , High schools -- South Africa -- Eastern Cape -- Social conditions
- Language: English
- Type: Thesis , Masters , M Ed
- Identifier: vital:16168 , http://hdl.handle.net/10353/468 , Teenage girls -- Sexual behavior -- South Africa -- Eastern Cape , High schools -- South Africa -- Eastern Cape -- Social conditions
- Description: Teenage pregnancy is a worldwide phenomenon. World Health Organisation (2009) reports that teenage mothers between the ages of 15-19 years account for 11% of births recorded worldwide. In South Africa it has been estimated that teenagers aged 17-19 account for 93% of all teenage pregnancies. A large proportion of these adolescents return to school after giving birth. Research has shown that there is a great deal of controversy about not only pre-marital sex, but also concerning whether teenage mothers should be allowed back in school at all. The aim of this study was to gain some insights into the lived experiences of teenage mothers in schools with particular reference to how they cope with school work and the responsibilities of motherhood. A case study of four teenage mothers who returned to school after giving birth was carried out. In-depth phenomenological interviewing designed to elicit the voices of the selected adolescents was done. There were five main findings. First, all four teenagers were minors, under the age of 18 when they gave birth. Two of them were even under the statutory age of consent. Second, upon return to school, teenage mothers experienced stigmatisation from peers and teachers and this forced them to continually negotiate their dual identities as mothers and learners. Third, teenage mothers experienced psychological emotions of stress; low self-esteem; shame and depression. Fourth, they also had sociological experiences in the form of material, financial and social support from family and friends. In some cases they experienced rejection from peers and abandonment by boyfriends who had made them pregnant. Some educators discriminated against and ridiculed teenage mothers. Fifth, teenage mothers reorganised their lives after childbirth and established routines that enabled them to cope with the demands of school work and the responsibilities of motherhood. iii The study concludes that, although viewed with scepticism by sections of the community and some educators, and given that some pregnancies are a result of abuse and unequal power relations between men and women in society, the policy of allowing teenage mothers back to school after giving birth gives them another chance to re-focus their lives. It is recommended that the voices of teenage mothers who return to school after childbirth should be taken into account to inform any planning for future policies on teenage pregnancy by schools and the state. It is further recommended that all educators should also be trained to be able to assist the teenage mothers instead of alienating them. There should also be counselling services available for the teenage mothers to enable them to deal with psychological and sociological problems they might encounter. For further research, students from different backgrounds should be the target of similar research. Another area of research should focus on academic performance of teenage mothers who return to school after giving birth. Lastly, there should be research that seeks to link what is taught in the Life Orientation curriculum and voices of teenage mothers.
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- Date Issued: 2012
Comparative biogeography and ecology of freshwater fishes in the Breede and associated river systems, South Africa
- Authors: Chakona, Albert
- Date: 2012
- Subjects: Freshwater fishes -- South Africa -- Breede River , Freshwater fishes -- South Africa -- Geographical distribution , Freshwater fishes -- Ecology , Feshwater fishes -- Genetics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5372 , http://hdl.handle.net/10962/d1015694
- Description: Distribution patterns and levels of genetic diversity in extant taxa are a product of complex palaeogeographic processes and climatic oscillations as well as the species’ intrinsic ecological adaptations. The Cape Floristic Region of South Africa presents a unique system for studying the processes that promote species diversification and distribution patterns. This region has a high degree of endemism of both terrestrial and aquatic biota and is clearly isolated from neighbouring areas by the Cape Fold Mountains and the Great Escarpment. The objective of this study was to firstly examine the ecology of freshwater fishes belonging to the genera Galaxias, Pseudobarbus and Sandelia in the south-western CFR. This was followed by an assessment of the genetic diversity of these taxa. Unique lineages were identified and their distribution was mapped. The work aimed to explore the role of the region’s complex palaeogeographic and climatic history as well as the role of the species’ ecological adaptations in driving lineage diversification and shaping contemporary distribution patterns. The four main components of the study can be summarised as follows: 1. Habitat associations of three widely distributed lineages of Galaxias zebratus Pseudobarbus burchelli and Sandelia capensis were evaluated at multiple localities in minimally disturbed mountain tributaries of the Breede, Duiwenhoks and Goukou River systems. The lineages have distinct habitat associations which were related to differences in their morphological traits. The slender-bodied Galaxias ‘nebula’ and the fusiform-shaped Pseudobarbus ‘Breede’ are capable of exploiting upper reaches with faster water velocity. By contrast, the laterally compressed Sandelia ‘eastern’ is restricted to lower reaches, making this lineage more susceptible to a wide array of impacts. 2. A recently discovered lineage of Galaxias zebratus, (Galaxias ‘nebula’), was found to be capable of tolerating emersion for a prolonged period of time. This is the first time that such capabilities have been documented in an African galaxiid. These adaptations have implications for the interpretation of Galaxias ‘nebula’s wide distribution range. 3. The phylogeography of Galaxias ‘nebula’ across its entire distribution range was investigated using two mitochondrial genes (cytochrome c oxidase subunit I (COI) and cytochrome b (cyt b)). This lineage has a complex evolutionary history that was influenced by both intrinsic and extrinsic factors. Rare events such as episodic drainage connections during Pleistocene and Holocene pluvial periods, possibly augmented by river confluences during periods of lower sea-levels and river capture events seem to be the most credible explanation for the extensive contemporary distribution and the relatively shallow genetic divergence between different river systems. 4. Mitochondrial cyt b sequences were used (i) to assess genetic diversity in G. zebratus, P. burchelli and S. capensis from the south-western CFR and (ii) to determine the roles of intrinsic ecological adaptations and extrinsic landscape and climatic changes in promoting genetic diversification and shaping present day distribution patterns of lineages in the three taxa. Marine incursions during periods of major sea-level transgressions are proposed to have isolated populations in upland refugia, thereby driving allopatric divergence in these species. Subsequent connections of rivers during wetter periods and lower sea-levels are proposed to have facilitated post-speciation dispersal of lineages to attain present day distribution patterns. While detailed morphological studies and further genetic analysis are needed to substantiate the taxonomic status of the newly discovered lineages of Galaxias zebratus, Pseudobarbus burchelli and Sandelia capensis, results of the present study indicate that the south-western CFR represents a previously unrecognised centre of freshwater fish diversity and microendemism in the broader Cape Floristic Region. Accurate identification of lineages and comprehensive mapping of their distribution is a fundamental pre-requisite for ecological studies, assessing conservation status and implementation of appropriate conservation measures.
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- Date Issued: 2012
Competence development in marine protected area professionals: a case study of the South African Marine Protected Area Management Training Course (SAMPATC)
- Authors: Lewis, Sebastian Giulio
- Date: 2012
- Subjects: Core competencies Employees -- Training of Marine ecosystem management
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1456 , http://hdl.handle.net/10962/d1003337
- Description: This study reviews a training programme on Marine Protected Area (MPA) management. It notes that although MPAs are well promulgated under legislation, reports have found that there are still key challenges facing the management of these areas. The research examines how the course was developed following the Lemm and Attwood (2003) report and designed to develop competences for effective MPA management. The aim is to identify how a MPA management training course produced competences apposite to the workplace settings of the participants. An interpretive case study method was used, in two phases. The first phase explored salient issues in MPA management in South Africa through analysis of the two key ‘state of MPA management’ reports and interviews with MPA professionals. The second was an analysis of the South African Marine Protected Area Management Training Course. This involved interviews with course designers, a review of the course materials, interviews with past course participants, and an analysis of course evaluations. Evidence emerged that supported the following findings: Challenges and problems facing MPA management still exist. Competence in key areas of MPA management was addressed in an effective work-integrated approach. Social learning was a key process in the development of these competences. The competences articulate well with the workplace of participants. Gaps exist between some of the management issues and the competences developed by the course, and some aspects of the course design are ineffective. From these findings it is concluded that: The course took up the majority of issues in MPA management through the development of key competences. The course design facilitated the development of these competences. The competences developed through the course are relevant to the workplace of MPA professionals. The research found that the course adequately addresses issues in MPA management through the development of competences. Some recommendations for improvements are made.
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- Date Issued: 2012
Comprehension and production of figurative language by Afrikaans-speaking children with and without specific language impairment
- Authors: van der Merwe, Kristin , Adendorff, Ralph
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123442 , vital:35438 , https://doi.org/10.2989/16073614.2012.693708
- Description: This article reports on the comprehension and production of figurative language, namely idioms and similes, in first language Afrikaans-speaking (AFR) boys, ages eight to 10 years, and first language Afrikaans-speaking boys with specific language impairment (SLI), also ages eight to 10. It draws on a larger study by Van der Merwe (2007; see also Van der Merwe & Southwood, 2008). Testing of the comprehension and production abilities of the children was conducted verbally and individually and elicited their understanding of 25 idioms and 25 similes. The idioms were first presented without context; if the child gave an incorrect interpretation, the idiom was placed in context. Raw scores show that the SLI group performed marginally more poorly than the AFR group, but there was no statistically significant difference between the comprehension of idioms by the two groups. The same can be said for the number of literal interpretations provided by the groups. Placing the idioms in context was beneficial to both groups. The simile completion task required the children to provide the last word of each simile. For both groups, the similes task proved to be easier than the idioms task but there was again no statistically significant difference found between the two groups. The results seem to imply that children at this developmental phase, aged eight to 10, whether language impaired or not, have not yet fully grasped figurative language as a concept and need explicit instructions on figurative language. The article ends with a reflection on the suitability of idioms and similes as particular categories of figurative language in studies of this nature.
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- Date Issued: 2012
Contrasting habitat associations of imperilled endemic stream fishes from a global biodiversity hot spot
- Authors: Chakona, Albert , Swartz, E R
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:7148 , http://hdl.handle.net/10962/d1011850 , http://www.biomedcentral.com/1472-6785/12/19
- Description: Knowledge of the factors that drive species distributions provides a fundamental baseline for several areas of research including biogeography, phylogeography and biodiversity conservation. Data from 148 minimally disturbed sites across a large drainage system in the Cape Floristic Region of South Africa were used to test the hypothesis that stream fishes have similar responses to environmental determinants of species distribution. Two complementary statistical approaches, boosted regression trees and hierarchical partitioning, were used to model the responses of four fish species to 11 environmental predictors, and to quantify the independent explanatory power of each predictor.
- Full Text:
- Date Issued: 2012
Contrasting habitat associations of imperilled endemic stream fishes from a global biodiversity hot spot
- Authors: Chakona, Albert , Swartz, E R
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6777 , http://hdl.handle.net/10962/d1008087
- Description: Knowledge of the factors that drive species distributions provides a fundamental baseline for several areas of research including biogeography, phylogeography and biodiversity conservation. Data from 148 minimally disturbed sites across a large drainage system in the Cape Floristic Region of South Africa were used to test the hypothesis that stream fishes have similar responses to environmental determinants of species distribution. Two complementary statistical approaches, boosted regression trees and hierarchical partitioning, were used to model the responses of four fish species to 11 environmental predictors, and to quantify the independent explanatory power of each predictor.
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- Date Issued: 2012
Contribution towards the development of a management plan for the baitboat and sport fishery for tuna in South Africa
- Authors: Newcombe, Hylton Cecil
- Date: 2012
- Subjects: Tuna -- South Africa , Tuna fishing -- South Africa , Fishery management -- South Africa , Fishery management -- Economic aspects -- South Africa , Tuna fisheries -- Catch effort -- South Africa , Tuna fisheries -- Economic aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5249 , http://hdl.handle.net/10962/d1005092 , Tuna -- South Africa , Tuna fishing -- South Africa , Fishery management -- South Africa , Fishery management -- Economic aspects -- South Africa , Tuna fisheries -- Catch effort -- South Africa , Tuna fisheries -- Economic aspects -- South Africa
- Description: Tuna are of significant global economic importance and a prime food source. Increased levels of fishing have resulted in many stocks being under threat and a number of species are considered to be overfished. The South African tuna industry has had limited management attention from the South African fisheries management agency. A recent development has been an increase in the number of tuna caught by small vessels that target the fresh tuna market in South Africa and overseas. This has highlighted the importance of developing a holistic management plan for the sector and creating an awareness, among vessel owners, of the importance of compliance with initiatives such as the Marine Stewardship Council (MSC). The South African tuna fishery comprises three sectors: baitboat, sport and longline, all of which are currently in need of acquiring more biological and fisheries data. This project was initiated to collate existing information and to collect additional information where possible. This encompassed a qualitative and quantitative assessment of the size and shape of the tuna fishing industry, which included estimates of total catch, effort, catch-per-unit-of-effort (CPUE) and stock structure (obtained through comparative estimates of age and growth), as well as socio-economic and economic information. A technique involving an examination of specific vertebrae was used to obtain age-growth information for T. albacares. These data were used to estimate von Bertalanffy (VBGF) growth parameters: F 2 1. , k 0.1 , and t₀ -0. 1 year. No significant differences in growth parameters were found in yellowfin tuna (Thunnus albacares) from different localities around the South African coast, i.e. from the south eastern Atlantic and the south western Indian Ocean. In addition, growth did not differ between South Africa and other regions (Draganic and Pelzcarski 1984, Fonteneau 1980, Gascuel et al. 1992, LeGuen and Sakagawa 1973, Lehodey and Leroy 1999, Lessa and Duarte-Neto 2004, Shuford et al. 2007, Stequert et al. 1996, Wild 1986, Yang et al. 1969). Further substantiation of the above-mentioned observations was found by recording differences in the sizes of fish caught in the inshore (baitboat and sport fishery vessels) and offshore (large pelagic longline vessels) sectors of South African tuna fisheries. A significant difference between the regions — in terms of the size of fish caught inshore — was noted, with mostly-juvenile fish being caught in KwaZulu-Natal (5.4 ± 3.5kg), sub-adult fish in the Eastern Cape (26.2 ± 13.4kg), and adult fish in the Western Cape (42.3 ± 14.4kg). Since mostly-adult fish were caught offshore by longliners, with no significant differences between regions, it is however possible th at adult fish predominantly inhabit the offshore region. Yellowfin tuna caught by the large pelagic longline fishery in the three managerial zones (A, B and C) were predominantly adult fish of similar size, namely Zone A: 38.9 ± 6.9kg; Zone B: 28.7 ± 4.6kg, and Zone C: 36.0 ± 5.1kg. The recreational ski boat sport fishery has remained stable, in terms of participation, consisting mostly of white middle aged males in the top 25% of household income distribution, having either permanent occupational status or being retired. Fishers within this sector are willing to incur great expense to partake in the fishery and they provide an important economic contribution to coastal towns, particularly in the Eastern Cape. The total catch (of 83t) of yellowfin tuna by the competitive sport fishery within the Western and Eastern Cape regions was considerably lower than that of commercial tuna baitboat catches, which amounted to 186t, and the large pelagic longline sector that caught t in 200. It is however likely that the competitive sport fishery's total yellowfin tuna catch (of 83t in 2009) of the Eastern and Western Cape competitive sport fishery was considerably less than the total yellowfin tuna catches of the whole South African deep-sea sport fishery. Longfin tuna are the primary target species of South Africa‘s baitboat fisheries, comprising an average of 86% of the total catch and generating ZAR49 million in employment income in 2002. South Africa was responsible for 20% of the total longfin tuna annual yield in 2004 in the southern Atlantic Ocean, behind Taiwan with 59%. However, yellowfin tuna only contributes a small percentage towards total catches (8.4 ± 8.2% between 1995 and 2009), generating ZAR1.3 million in employment income in 2002. Of the four vessel categories comprising the tuna baitboat fishery, ski boats had the highest yellowfin tuna CPUE in 2009 (117 ± 62 kg.vessel⁻¹.day⁻¹) and the lowest effort. The ski boats sector is the most opportunistic fishery as they are only active when either longfin or yellowfin tuna are in high abundance. At such times catches are guaranteed, so can be expected to offset expenses. In 2009 the CPUE for yellowfin tuna for 15–19m vessels and freezer deckboats was 12 ± 20kg.vessel⁻¹.day⁻¹ and 3 ± 6kg.vessel⁻¹.day⁻¹, respectively. These vessels specifically target longfin tuna when they are in abundance. Since the start of the tuna baitboat fishery in 1995, there has been a substantial increase in the number of new entrants. In 2002 this sector had a fleet size of 82 vessels with a capital value of ZAR163 million and a total employment income of ZAR58 million, employing 2 173 fishers, of which 87% were black African. The commercial tuna baitboat fleet has subsequently grown to 200 vessels and 3600 crew, with 110 active vessels fishing for a combined fleet average of 46 days per year. There are a high number of owner-operated vessels. Since 2007 the fishery's profit to cost ratio has been low due to the low abundance of tuna stocks off the coast of South Africa, which has resulted in poor catch returns, placing economic pressure on the fishery. The baitboat industry is a low-profit-margin fishery with a total net catch value worth ZAR90 million in 2009 (Feike 2010). The abundance of yellowfin tuna influences profit margins, with very high profits being made when abundance and catches are high. The large pelagic longline fishery has a total allowable effort of 43 vessels of which only 30 vessels fished during 2009, when a reported 766t of yellowfin tuna were caught, representing a total tonnage far in excess of that obtained by the combined effort of the baitboat and sport fishery. It is, however, assumed that considerable underreporting of catches takes place within this fishery, which means that the estimated total net catch value of ZAR100 million could, in fact, be much higher. Such underreporting of catches is of great concern for this fishery, as is the high bycatch of Chondricthians spp. that significantly outweighs imposed regulatory limits (DEAT 2007). The present study demonstrates the current lack of comprehensive catch and effort data for the sport, baitboat and longline fisheries as well as the serious limitations and flaws associated with current databases. Results from the present study have drawn attention to a number of high-priority research needs, as outlined below. (1) A major lack of comprehensive catch and effort data for the sport fishery, which can be rectified by focussing on obtaining more competition data, as well as high-quality catch and effort and socio-economic information, as opposed to relying on information from non-club anglers (Gartside et al. 1999, Williams 2003, Cass-Calay 2008). Acquisition of such data is relatively inexpensive: the location of organized clubs and their frequent competition meetings provide widespread coverage along the Southern African coastline. Such data acquisition efforts have the potential to provide reliable information on spatial catch trends. (2) Validation of vessel catch return data is required for commercial fisheries and on some recent data that has emerged from studies of catch rates and trends for target species, particularly in the longline fishery. In this context it should be noted that the most recent peer-reviewed publications on this exploratory fishery were published more than a decade ago (Kroese 1999, Penny and Griffiths 1999). Additional studies need to be undertaken and journal articles published on the current stock status of South African catches of yellowfin and bigeye tuna and swordfish.
- Full Text:
- Date Issued: 2012
Critical factors for enabling knowledge sharing between government agencies within South Africa
- Authors: Mannie, Avain
- Date: 2012
- Subjects: Administrative agencies , Knowledge management , Business intelligence
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: vital:8822 , http://hdl.handle.net/10948/d1019699
- Description: Globally, organisations have recognised the strategic importance of knowledge management (KM) and are increasingly focusing their efforts on practices to foster the creation, sharing and integration of knowledge. Whilst most research in Knowledge Management (KM) has focused on the private sector, there is a breadth of potential applications of KM theory and practice for government agencies to adopt in search of resolving pertinent problems. The purpose of this study is to examine the factors that influence the effectiveness of knowledge management towards collaborative problem solving in government. What is missing is research-based evidence of the factors that influence the main factors for knowledge sharing across government agencies. Given this gap, the researcher addresses the research question: In government agencies mandated to resolve issues of crime, what are the key factors required which support and influence the collaborative sharing culture? Upon analysing the data, the researcher found the following key factors as being determinants on knowledge management: organisational culture, learning organisation, collaboration, subject matter experts and trust. The two factors – organisational culture and learning organisation were identified as the most significant factors which lay as the root or core for the ‘knowledge tree’. Once these roots are in place, the other factors will gain their significance on knowledge management. These findings serve to extend the findings of the existing literature within the government sector. This study is important because the findings provide government agencies with critically important information to guide their actions towards ensuring a knowledge sharing culture is embedded in government. Whilst the empirical findings do not focus on databases or information technology specifically, it is important to acknowledge the use of both technology and people. The main concern is with managing an organisation’s knowledge assets: creating, storing, protecting, disseminating and using mission-critical knowledge. When people need knowledge, is it the right knowledge and is it timely and easy to locate and access? Is this precious commodity updated as learning occurs and better ways of doing things are discovered? The awareness of the value of knowledge to a business, coupled with its leadership, acts as an integrator that improves cross- functional communication and cooperation. Shared knowledge not only makes for a more effective, efficient and agile organisation, but creates a common perspective and culture that produces a natural consistency of successful decisions and actions. The collaborative knowledge tree model proposed in this study uses the analogy of a tree when viewing South African government agencies as the branches of a collective tree (government). This ‘tree’ requires leaders and policy making to ‘dig deep’ into understanding the roots of the tree in order to ensure that the appropriate ‘seeds’ are planted such that the tree grows and is able to provide the necessary fruit required. Ultimately, as suggested by former President Thabo Mbeki (2012) in his address, the role of knowledge would thus be seen as a collaborative means towards the betterment of society.
- Full Text:
- Date Issued: 2012
Curriculum reform in Lesotho: exploring the interface between environmental education and geography in selected schools
- Authors: Raselimo, Mohaeka Gabriel
- Date: 2012
- Subjects: Curriculum planning -- Lesotho Curriculum change -- Lesotho Educational evaluation -- Lesotho Environmental education -- Study and teaching (Secondary) -- Lesotho Geography -- Study and teaching (Secondary) -- Lesotho Agenda 21 (Program)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1488 , http://hdl.handle.net/10962/d1003369
- Description: This study sought to explore the interface between environmental education (EE) and school geography with a view to understanding a process of curriculum reform in the context of Lesotho. The research was based on the curriculum reform process that was initiated by a Danish donor-funded project, known as the Lesotho Environmental Education Support Project (LEESP), which operated from 2001 to 2004. Driven by a sustainable development imperative, the project was intended to assist Lesotho in the implementation of local action for Agenda 21 by introducing environmental education into the formal education system. Deviating slightly from much published research on geographical and environmental education, which focuses on how geography contributes to environmental education, this study explored how the latter has shaped the former in terms of content and pedagogy. Using the lens of critical curriculum theory, I sought to understand the political nature of the curriculum and of curriculum change, focusing on the LEESP curriculum policy development, dissemination and implementation at classroom level. The study employed Bernstein's concepts of classification and framing to illuminate issues of power and control between discourses, and between teachers and learners. Operating within an interpretive qualitative research orientation, the study used a case study method focusing on five secondary/high schools in Lesotho. The data was generated through document analysis, interviews and classroom observations. The study examined the assumptions, values and ideologies underpinning environmental education curriculum intentions as reflected in LEESP documents. It also investigated the social process of conceptualising and disseminating environmental education to understand the challenges faced as education practitioners made sense of environmental education innovations in the specific contexts of Lesotho, and how these could possibly influence what happens at the classroom level. The analysis of the LEESP documents revealed that while there are many areas of synergy between the LEESP environmental education policy guidelines and the national education ideals in Lesotho, achievement of the transformational visions of action competence, which was the overarching concept in the reform process, would require major structural changes. The study also highlights issues of participation, contestations, tensions and contradictions associated with the conceptualisation and dissemination of environmental education. At implementation level, there is a disjuncture between environmental education policy intentions and practice. Geography teachers in the research schools generally understood the existence of environmental education in their schools in terms of environmental management. The findings also revealed that while there is generally a strong environmental dimension in geography content, as reflected in both curriculum materials and classroom practice, the subject still retains its disciplinary boundaries and makes little use of knowledge from other subjects or the everyday knowledge of the learners. Finally, it emerged that while the geography teachers in their rhetoric espoused learner-centred methods, in practice they generally employed traditional teacher-centred and book-centred methods. The study concludes that a lack of change in school geography in Lesotho, of the sort envisaged in LEESP, may be attributed to contextual and structural factors such as an overemphasis on examinations, and certain perceptions on the part of teachers and learners embedded in the history and culture of their society. A model of teacher professional development capable of supporting curriculum change is therefore proposed.
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- Date Issued: 2012
Dasein online! a study of the experience of flow in the virtual playground
- Authors: Godley, Donnae-Maree
- Date: 2012
- Subjects: Internet games -- Social aspects -- Research , Virtual reality -- Social aspects -- Research , Fantasy games -- Social aspects -- Research , Human-computer interaction -- Research , Online identities
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2983 , http://hdl.handle.net/10962/d1002492 , Internet games -- Social aspects -- Research , Virtual reality -- Social aspects -- Research , Fantasy games -- Social aspects -- Research , Human-computer interaction -- Research , Online identities
- Description: The purpose of this study was twofold. First, it aimed to present and understand the experiences of online gamers from the paradigm of positive psychology. To achieve this, the phenomenon of flow was investigated to see whether or not, it is experienced whilst gaming online and if present, how it is revealed in this context. The second purpose was to contribute to theory building and to respond to extant research recommendations. Aligned with a qualitative orientation, the method selected to achieve the objectives of the study was interpretative phenomenological analysis. A sample of four participants who met the criteria for inclusion in the research were selected and interviewed using semi-structured interviews. Data was analysed and interpreted inductively and categorised into superordinate themes. These were presented as two sections: Section A explored the experience and meaning of online gaming through the following three superordinate themes; intention, pre-gaming rituals and gaming process. Section B discussed the social experience and meaning of gaming online through the superordinate theme, a gamers way. This study both challenged and supported theory and research in the field and introduced novel areas, such as pregaming rituals and the subthemes; marijuana and gaming space. This is a notable and promising "side effect" of a research design that is exploratory. Findings called for future multi-disciplinary research into flow, gaming and online relationships considering Csikszentimaihalyi‟s concept of autotelic relationships and Heideggers‟ philosophical framework.
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- Date Issued: 2012
Deciding and doing what's right for people and planet : an investigation of the ethics-oriented learning of novice environmental educators
- Authors: Olvitt, Lausanne Laura
- Date: 2012
- Subjects: Environmental education Environmental ethics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1913 , http://hdl.handle.net/10962/d1007238
- Description: This study probes the ethics-oriented reflexive deliberations of three novice environmental education practitioners in South Africa. Two of the cases examined work in a local government context, and the third in an environmental non-governmental organisation context. All three practitioners are studying a one-year professional development course in environmental education. The research asks how their ethical deliberations ‘come to be what they are’, at the interface of their workplace and course-based learning processes. Working within a relational, social realist ontology, the study takes a sociocultural-historical approach to learning, development and social change. Cultural-historical activity theory (CHAT) provides theoretical tools and a descriptive language to approach the rich, qualitative data derived from workplace and course observations, extensive interviews, and document review. Critical discourse analysis was used as a secondary analytical tool to probe ethical and environmental discourses that were found to be influential in the course and workplace activity systems. Data from the three case studies was analysed in stages. In the first stage, CHAT provided a theoretical perspective and language of description to analyse the interacting activity systems in which each learner-practitioner’s ethics-oriented reflexive deliberations occurred. This provided a platform for the second stage of analysis which was framed by Margaret Archer’s (1995) social realist theory of morphogenesis/ morphostasis, followed by a summative retroductive analysis, to give an account of the interplay of historically-emergent social and cultural structures and individual reflexivity in relation to the ethical dimensions of environmental education practice. The study traces how ethics-oriented reflexive deliberations occur at the untidy, unpredictable intersection of workplace, course and personal contexts, and are strongest when they are situated in authentic contexts that resonate with learner-practitioners’ ‘ultimate concerns’ (after Archer, 2003; 2007). In this study, the learner-practitioners’ ‘ultimate concerns’ included family, personal well-being, social justice, cultural identity and religious commitments. The scope and depth of learner-practitioners’ social-ecological knowledge was also identified as a key factor influencing ethics-oriented reflexive deliberations, although the mediation of such knowledge can be hindered by language and conceptual ii barriers, amongst others. The study also noted how ethical positions circulating in the workplace, course and personal contexts were diverse, uneven and dynamic. Some ethical positions were found to be more explicitly differentiated than others, either resonating with or being overlooked by the learner-practitioners as they deliberated the ethical dimensions of their environmental education practice. In situations where there was limited depth, conceptual clarity and/ or confidence to engage directly with ethical concerns, there was a tendency towards (inadvertent) ethical relativism. Insights derived from the study suggest that these factors have limiting effects on the ethics-oriented reflexive deliberations of novice environmental educators. These insights point to the need for ethical deliberations to be re-personalised in context and underpinned by depth knowledge. A relational and pragmatic approach to environmental ethics (that recognises the validity of judgemental rationality – which can be fallible – and which seeks out practical adequacy) is put forward as appropriate and potentially generative in environmental education and training processes. This would need to be supported by careful attention to the influence of environmental discourses and practices in shaping ethical deliberations, and may also be helpful in developing a much-needed accessible, everyday language of ethical engagement. This study’s contribution to new knowledge in the field of environmental education is through its account of ethics-oriented reflexive deliberations emerging (in the Archerian morphogenetic sense) in complex, indeterminate ways at the interface of sociocultural and social-ecological contexts. The ethics-oriented reflexive deliberations of novice environmental educators occur in relation to their ‘ultimate concerns’ and are advanced or hindered by the historically-emergent practices, discourses and material realities of their workplace, personal and educational contexts. These insights require that the complex interplay of intersecting contexts and concerns that shape ethics-oriented reflexive deliberations be acknowledged and carefully mediated in both workplace-based and coursebased professional development processes.
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- Date Issued: 2012
Designing a strategy to bring about a greater professional confidence for educators by improving their involvement in their own continous professional development
- Authors: Oosthuizen, Lizette Clarise
- Date: 2012
- Subjects: Teacher educators -- Professional relationships , Teachers -- Training of
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:9559 , http://hdl.handle.net/10948/d1012145 , Teacher educators -- Professional relationships , Teachers -- Training of
- Description: To ensure the professionalism of the teaching force, it is vital that the growing gap between the knowledge educators acquired during their years of training and emerging knowledge about teaching and education during their teaching careers be closed. The continuous professional development (CPD) of educators is a much-debated issue, the general consensus being that it is imperative that educators themselves become directly involved in their own CPD. School leadership should therefore establish what educators find meaningful and invest in CPD programmes that respond to their needs. Educator development is considered as productive when the educators are involved in planning, decision-making, implementation and evaluation around the CPD programmes offered to them. As an office-based educator responsible for educator development and training, educators‟ perceived lack of interest in their own CPD prompted me to investigate how their professional confidence could be boosted through improved involvement in their own CPD. The research question that underpinned this study was: What are the perceptions of educators in the Uitenhage area of their involvements in their own CPD and how to find a strategy to enhance their professional confidence through such involvement? This study adopted the interpretive research paradigm, as the aim was to understand how educators understood their involvement in their own CPD. The qualitative research methods employed, allowed me to share the experiences of my participants. The research sample consisted of Integrated Quality Management Systems (IQMS) coordinators, as members of the school development team (SDT) responsible for educator development, from twelve primary schools in the Uitenhage District. In Phase 1 of the study, data were collected through questionnaires as well as individual and group interviews. Phase 2 consisted of a workshop for the participants, focusing on the key issues identified from the completed questionnaires and interviews. From the data analysis, five themes emerged, namely the contribution by the school, school management team (SMT), Department of Education (DoE) in the educators‟ CPD; the role of the individual educator in his/her own CPD; the factors influencing the effective implementation of educators‟ CPD; the skills and competencies that educators need to acquire through CPD; and the role of the IQMS process in the CPD of educators. Based on the research findings, a strategy was designed to guide educators to increase their professional confidence through improved involvement in their own CPD. Specific recommendations were formulated, such as that adequate time should be allocated for the CPD of educators; school leadership should make a concerted effort to motivate educators to become involved in CPD programmes; and educators should be encouraged to learn collaboratively through their involvement in communities of learning. The conclusions from this research are that educators should be life-long learners, actively involved in their own CPD and that schools, SMTs and the DoE should assist them by providing the necessary support, resources and guidance through enabling conditions conducive to a culture of learning.
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- Date Issued: 2012
Determining the willingness-to-pay for the removal of a local undesirable land use
- Authors: Cloete, Le Ann
- Date: 2012
- Subjects: Pollution , Willingness to pay -- South Africa -- Port Elizabeth , Pollutants
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:9010 , http://hdl.handle.net/10948/d1015979
- Description: A manganese ore dump and oil tank farm have been situated in the Port Elizabeth harbour for more than forty years. Although these facilities are independently operated and managed, they are viewed as one distinct disamenity, and there is strong local opposition to their continued location in the harbour. The negative environmental impacts (for example, water and air pollution) caused by the ore dump and tank farm have been well documented. This pollution takes the form of oil leaks from the oil tank farm, and ore dust pollution from the manganese ore dump. The air pollution caused by the manganese ore dump is a result of the dump currently being an open air handling and storage facility. The ore dust is dispersed into the air due to strong prevailing winds in the Bay and has resulted in respiratory illnesses of residents living in close proximity to the facility. Oil pollution, due to leakages experienced at the oil tank farm, has extended far beyond the periphery of the harbour. Inter alia, there has been a decline in local fish populations, as well as a decline in passive and active use satisfaction associated with the adjacent beach area, i.e. Kings Beach. These oil leakages, first reported in 2001, could have a detrimental effect on the Blue Flag status of this beach, as well as the Blue Flag status of other beaches situated further up the coast. The lease agreements for the oil tank farm and manganese ore dump are set to expire in 2014 and 2016, respectively. As yet, there is no consensus on when these disamenities will be (re)moved. In order to mitigate the secondary impacts of these facilities, both of them should be removed. Although these impacts should be the focus of public policy debates and cost-benefit assessments, no direct valuation method exists to value the economic cost to affected communities. Instead, non-market valuation methods, such as the contingent valuation method (CVM), are often applied to assign values to these economic costs. This study seeks to determine Nelson Mandela Bay households‟ preferences for the immediate removal of the manganese ore dump and oil tank farm from the Port Elizabeth harbour. This case was selected since it represents a current public policy debate issue that has not been resolved. Monetary estimates of people‟s preferences for the removal of pollution-creating activities can assist policy-makers and other stakeholders when locating industries in an urban setting. These estimates can also be of use in understanding the benefits associated with air and water quality improvement projects. The primary valuation technique used in this study is the CVM. This method was chosen as it is capable of measuring the economic significance of lost passive-use values of individuals affected by negative externalities. Both a non-parametric and a parametric estimate of mean willingness-to-pay (WTP) were derived. On average, a respondent was willing to pay a once-off amount of between R47.09 (non-parametric estimate) and R93.21 (parametric estimate). Non-parametric estimation (via the Turnbull estimator) was conducted to test the sensitivity of the parametric results (via a logit model). The logit model‟s results showed that the probability of a „yes‟ answer to the referendum question varies with a number of covariates in a realistic and expected way, which offers some support for the construct validity of this CV study. Household income, education, age, and disamenity awareness were significant determinants of individuals‟ responses to the WTP question. A summary of the findings of WTP estimates for both parametric and non-parametric analysis is provided in Table 1. Three primary recommendations stem from this study. Firstly, the study used a relatively small sample size. Although it was sufficient for a pilot study it is recommended that future research into this issue should aim for a much larger sample size to ensure more precise estimates of the WTP for the removal of the disamenity. Secondly, the conservative non-parametric mean WTP estimate should be used as opposed to the higher parametric mean WTP estimate. Third, the aggregate WTP estimation constitutes only a partial analysis of cost. A number of other factors and value streams need to be analysed and compared with the cost estimates generated by this study if adequate holistic decision-making is to take place with regard to the removal of the manganese ore dump and oil tank farm. More specifically, the total WTP estimated in this study should be viewed as only one input into a comprehensive social cost-benefit analysis to determine the desirability of the removal of this disamenity for wider society.
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- Date Issued: 2012
Dreams, sexuality and fantasy: a psychoanalytic reading of K. Sello Duiker’s novels
- Authors: Kirton-Els, Teneille
- Date: 2012
- Language: English
- Type: Thesis , Doctoral , DLitt et Phil
- Identifier: vital:11890 , http://hdl.handle.net/10353/d1020154
- Description: The primary aim of this thesis is to provide a text-based literary study exploring the characters and themes created by K. Sello Duiker in the three novels, Thirteen Cents, The Quiet Violence of Dreams and The Hidden Star. Duiker’s work is significant because it highlights prominent societal challenges prevalent in post-apartheid society. By analysing Duiker’s novels one acquires a better understanding of this author, an understanding of the world that contributed to the creation of his texts and his contribution to South African literature. Insight into Duiker’s fictional world allows for a careful investigation of the prominent societal issues prevalent in Duiker’s work - a world riddled with violence, issues of sexuality and psychological distress. For this purpose this thesis is premised on the notion that underpinning K. Sello Duiker’s oeuvre is a central focus on dreams, sexuality and fantasy. Logically, therefore, the main focus of the study is specifically on the inner working of the characters’ minds and how they deal/ or are unable to cope with contemporary social concerns, often resulting in psychological turmoil and dysfunctionality. For this reason, prominent themes examined in this study are the interpretation of dreams, an exploration of sexuality and an examination of fantasy in the three novels. Psychoanalytic literary theory, with the main focus being specifically on the theories presented by Sigmund Freud is used as an analytic tool to read Duiker’s texts. Psychoanalytic theory is arguably the most appropriate for analysing Duiker’s novels as it allows one to investigate the characters’ psyches and the psychological effect of societal influences on these characters. In addition, one is also able to examine how the characters are able/ unable to deal with the trauma caused by the contemporary issues in society – issues of violence, sexuality and psychological distress. Thus, one is able to grasp an overall understanding of the characters’ behaviour and actions. Furthermore, the characters’ experiences are based on the behaviour and incidents of real people, people suffering from psychological dysfunctionality, sexuality issues and identity crisis. The first chapter discusses post-apartheid literature, and provides a brief background on Duiker, his works and his conception as a writer. Chapter two provides an overview of psychoanalytic theory and on the relevant theories of Sigmund Freud. Chapter three offers a reading of Thirteen Cents, a novel that pays particular attention to the lives of children living on the streets of Cape Town. In the next chapter The Quiet Violence of Dreams is examined with a special focus on Duiker’s experimentation with form in the construction of this novel. Aspects pertaining to sexuality and dreams are also examined. Chapter five pays particular attention to magical realism and fantasy in The Hidden Star.
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- Date Issued: 2012
Effect of full and semi-scavenging rearing systems on crop contents and the quality of meat from village chickens during spring season of Eastern Cape, South Africa
- Authors: Hanyani, Charles Tawanda
- Date: 2012
- Subjects: Chickens -- Feeding and feeds -- South Africa -- Eastern Cape , Chicken breeds -- South Africa -- Eastern Cape , Meat -- Quality -- South Africa -- Eastern Cape , Forage plants -- South Africa -- Eastern Cape , Crops -- Nutrition -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11807 , http://hdl.handle.net/10353/440 , Chickens -- Feeding and feeds -- South Africa -- Eastern Cape , Chicken breeds -- South Africa -- Eastern Cape , Meat -- Quality -- South Africa -- Eastern Cape , Forage plants -- South Africa -- Eastern Cape , Crops -- Nutrition -- South Africa -- Eastern Cape
- Description: The objective of this study was to compare the nutrient status of full scavenging and semi-scavenging village chicken production systems. The semi-scavenging chickens were given broiler finisher mash between 14-24 weeks of age, whilst the full scavenging relied on natural foraging. The study also sought to compare the quality of meat from chickens from the two systems. After slaughtering the chickens, the crop contents were physically separated and analysed for chemical composition. Meat pH and colour were measured on the breast muscle of individual carcasses and a consumer sensory evaluation was also done on the breast muscle. The mean crop content weights per day were significantly higher in full scavenging chickens (±16.7g/day biomass) than in semi-scavenging chickens (±9.14g/day). Dry matter, calcium, and phosphorus levels were higher in the crop contents of the full than in the semi-scavenging chickens but crude protein, crude fibre and metabolisable energy were higher in the latter system. Semi-scavenging (1.3 ± 0.05kg) carcasses were heavier (P<0.05) than full scavenging ones (1.0 ± 0.06kg). The ultimate pH (24h) (pHu) of meat from full scavenging chickens (6.0 ± 0.03) was higher (P<0.05) than that of meat from the semi-scavenging chickens (5.7 ± 0.04). Meat from the full scavenging chickens had higher L* values (60 ± 1.2) than meat from the semi-scavenging chickens (47 ± 0.8). The a* value of meat of full scavenging chickens was significantly (P<0.05) less (4 ± 0.4) than that of meat from semi-scavenging chickens (15 ± 1.3). There was a significant positive (0.60) correlation between pHu and L* of meat from village chickens across rearing systems. The semi-scavenging system meat had better sensory attributes than the meat from the full scavenging system. Female consumers scored the typical flavour of village chicken meat across rearing systems higher (P< 0.05) than male consumers. The Shona consumers scored the meat higher (P< 0.05) than the Xhosa, Zulu, Ndebele and other tribes for initial juiciness, first bite impression and muscle fibre and tenderness of the chicken across rearing systems. Consumers scored of the meat from the semi-scavenging system higher (P<0.05) on initial juiciness (4.3 ± 0.20), first bite impression (4.2 ± 0.197), muscle fibre tenderness (4.5 ± 0.217) than meat from the full scavenging chickens. There were positive correlations (0.46) between aroma intensity and overall flavour intensity across both rearing systems. The semi-scavenging system produced better carcass characteristics, lighter (L*) meat and more consumer acceptable meat than full scavenging chickens. Therefore the full scavenging rearing system had better nutrient composition in its scavenging feed resource base, although the semi-scavenging systems produced chickens with better carcass, meat pH, colour and sensory characteristics than the full scavenging chickens.
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- Date Issued: 2012
Effects of feeding Moringa Oleifera leaf meal as an additive on growth performance of chicken, physico-chemical shelf-life indicators, fatty acid profiles and lipid oxidation of broiler meat
- Authors: Wapi, Cwayita
- Date: 2012
- Subjects: Moringa , Broilers (Chickens) , Meat -- Quality
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11822 , http://hdl.handle.net/10353/d1007546 , Moringa , Broilers (Chickens) , Meat -- Quality
- Description: Effects of feeding Moringa oleifera leaf meal as an additive on growth performance of chicken, physico- chemical shelf-life indicators, fatty acids profiles and lipid oxidation of broiler meat The main objective of the study was to determine the effect of M.oleifera leaf meal (MOLM) as an additive on growth performance, carcass characteristics, physico-chemical shelf-life indicators (colour, ultimate pH, driploss), fatty acids profiles and lipid oxidation of meat from broilers. A total of 432 1day old unsexed broiler chicks (Aviane 48) were randomly allocated to four dietary treatments (TRTS) in 72 cages. There were 18 cages per treatment and each cage allocated 6 chicks. Water and feed was provided at ad libitum. The feeding phases were, prestarter (0-7 Days), starter (8-18 Days), grower (19-28 Days), finisher (29-35 Days). The four TRTS contained graded levels of MOLM at 1000g/ton, 750g/ton, 500g/ton, and 0g/ton (control), respectively. The birds were slaughtered at 35 days of age. Breast muscles were sampled for meat, ultimate pH (pHu ), colour, drip loss over a 7 days shelf-life test. After each day’s test sub-samples were dipped in liquid nitrogen and kept at -180 C for thiobarbituric acid reactive substances determination. On Day1 and Day 7 extra sub-samples were also kept at -180 C for fatty acids analysis.The TRTS had no effect on average feed intake (AFI), feed conversion efficiency (FCE), and on average daily gain (ADG). Slaughter weight (SW), carcass weight (CW), dressing percentage and gizzard weight (GW) values were similar in all TRTS. Liver weight (LW), heart weight (HW), and gastro-intestinal fat (GIF) differed in all the TRTS, with treatment 2 having the highest value of HW (28.3±2.55), and LW (44.2±1.60) was the highest on treatment 4 . The pH values in all TRTS were constant from Day1 to Day5, reached peak on Day6, and then declined on Day7. Meat from broilers given treatment 1 with MOLM (1000g/ton) had the highest lightness (L*) values. The redness (a*) values were the highest in meat from treatment 2 (750g/ton MOLM). Treatments had no effect on yellowness (b*) values and on drip loss of the breasts. During storage L* values were high from Day1 to Day5 and decreased from Day6 to Day7. Drip loss increased with storage time as expected. Treatment 4 (control) had the highest proportions of poly-unsaturated fatty acids (PUFA) (30.3±1.87). Treatment 1 (1000g/ton) had the highest proportion of saturated fatty acids (SFA) (60.9±1.87). Treatment 1 (1000g/ton) had the highest proportion of SFA (60.9±4.30). Treatment 2 (750g/ton) had the highest n-6/n-3 ratio than other TRTS. Days had no effect (P>0.05) on PUFA, SFA, and n-6/n-3 ratio. Treatment 1 had a highest amount of malondialdehyde (MDA), treatment 4 had no effect (P>0.05) on MDA . Storage time had an effect (P<0.05) on MDA levels, except for on Day1 and Day7. Day2 had the highest amount of MDA (0.7±0.08). The use of MOLM as an additive in broiler diets reduced lipid oxidation in meat, and maintained the quality of the broiler meat during storage. It also did not have any adverse effects on the growth performance of broilers. Therefore, it has the potential to be used as an additive in broiler diets.
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- Date Issued: 2012
Efficacy of organic and synthetic insecticides on the control of cotton pests: The bollworm complex, Helicoverpa armigera, Diparopsis castanea, Earias insulana (Noctuidae) and the leafhopper, Jacobiell
- Authors: Malinga, Lawrence Nkosikhona
- Date: 2012
- Language: English
- Type: Thesis , Masters , MSc (Zoology)
- Identifier: vital:11791 , http://hdl.handle.net/10353/d1006798
- Description: A research was conducted on cotton to test different plant extracts with potential insecticidal properties against bollworms (Noctuidae) and leafhoppers (Cicadellidae) for the use by small-scale, cotton farmers. The study was carried out during the 2006/07 and 2007/08 seasons at ARC Institute for Industrial Crops, Rustenburg (25°39.0 S, 27°14.4 E) in the North West Province of South Africa. Four organic insecticides, tobacco (Nicotiana tabacium), khaki weed (Tagetes minuta), thorn apple (Datura stramonium) and garlic (Allium sativum) were compared with two chemical treatments, Mospilan® (acetamiprid) and Decis® (deltamethrin), and an untreated control. The cultivar, DeltaOPAL, was planted and the trial conducted using standard practices. Overall, Decis® and tobacco treatments exhibited significantly less bollworm larvae than the other treatments. Tobacco was the most promising biological pesticide against American bollworm (Helicoverpa armigera) and spiny bollworm (Earias insulana) larvae. All the treatments were significantly effective against the red bollworm (Diparopsis castanea) larvae, but Decis® and Mospilan® provided the best control. Although khaki weed, garlic and thorn apple were promising biological pesticides against the bollworm complex, tobacco was the most effective organic treatment. Mospilan® seemed to be more effective on the control of leafhoppers (Jacobiella fascialis), followed by Decis® and tobacco. Among the plant extracts, tobacco and garlic gave higher seed cotton yields compared to the khaki weed and thorn apple during both study seasons. In 2006/07, none of the treatments reached the corresponding economic threshold levels (ETLs). In contrast, in 2007/08, only rarely were the treatments (mostly Decis® and Mospilan®) below the corresponding ETLs. These differences were attributed to the higher rainfall recorded during the 2007/08 season, which reduced the effectiveness of the treatments by partly washing away the pesticidal applications. In addition, a high weed infestation also created competition for nutrients in the soil, thus resulting in lower (0.50-1.25 ton/ha in 2007/08 vs 2.50-5.00 ton/ha in 2006/07), but acceptable cotton seed yields. In conclusion, it is suggested that some plant extracts (particularly from tobacco and garlic) can be used as a cheaper and more environment-friendly alternative to chemical insecticides for the control of bollworms and leafhoppers, although it has been demonstrated that their efficacy do not reach the one of chemical treatments. Further research in the near future is recommended.
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- Date Issued: 2012