Synthesis and biological evaluation of novel thiazole-based compounds
- Authors: Olawode, Emmanual Oladayo
- Date: 2016
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/62955 , vital:28325
- Description: Thesis embargoed for one-year period. Expected date of release: April 2019
- Full Text:
- Date Issued: 2016
Synthesis and characterization of group 12 dithiolate complexes as single source precursors for the preparation of hexadecylamine capped metal sulfide nanoparticles and polymer
- Authors: Osuntokun, Jejenija
- Date: 2016
- Subjects: Nanotechnology Nanoparticles Semiconductors
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/14060 , vital:39801
- Description: A series of heteroleptic mixed ligand complexes of some alkyl substituted thiourea, tetramethyl thiuram disulfide and 1-cyano-1-carboethoxy-2,2 ditholate of Zn(II) Cd(II) and Hg(II) have been synthesized by stoichiometry reactions of the ligands with respective metal salts. They have been characterized with analytical and spectroscopic techniques. Seven out of the 19 complexes synthesized are pyridine 2, 2 bipyridine and 1, 10 phenanthroline adducts of dissopropyl parent adducts of Zn(II) and Cd(II) complexes. All the complexes are proposed as four coordinate except the pyridine adducts, 2, 2’ bipyridine and 1, 10 phenanhroline adducts that are proposed as five and six coordinate respectively. All the complexes are solid, air stable and moisture stable for a many months. They are not soluble in common organic solvents but partially soluble in coordinating solvents like DMF and DMSO and due to their insolubility problems all attempts to grow single crystal of the complexes proved abortive. The complexes gave respective metal sulfide on thermal decomposition in TGA and this makes them to be potentially useful single source precursor for the synthesis of metal sulfide. All the complexes were invariably thermolysed in HDA to synthesis a series of HDA-capped ZnS, CdS and HgS nanoparticles. The optical properties of the nanoparticles reveal that they are all blue-shifted from the absorbance edge and this confirms quantum confinement of the nanoparticles. The transmittance electron microscope showed that the nanoparticles are in nanodimension. ZnS nanoparticles from the pyridine adducts gave HDA-capped ZnS nanoparticles with a mixture of hexagonal and cubic phases while the HDA capped CdS from the 2, 2 bipyridine and 1,10 phenanthroline gave anisotropic nanoparticles. The sizes of the CdS from the 1,10 phenanthroline adducts were also found to be biggest while CdS nanoparticles from 2,2 bipyridine adduct were also revealed to be bigger than the particle sizes obtained from the parent complex, (1-cyano-1 carboethoxyethylene-2,2-dithiolato- κ,S’S)-bis(N, N’-diisopropylthiourea -κS)cadmium(II). ZnS and CdS polymer encapsulated nanocomposites were also synthesized using a solution casting method. The polymers employed were; Polymethyl metharcrylate (PMMA), Poly(vinly alcohol) (PVA), and poly vinyl pyrrolidone (PVP). The structural and thermal properties of the pure polymers and the respective nanocomposites were investigated. It was observed that the ZnS/PVA and CdS/PVA were the most thermally stable composites when the thermal stability of the pure polymers were compared relative to the nanocomposites using data obtained from thermal decomposition results of the TGA.
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- Date Issued: 2016
Synthesis and exploration of resorcinol derivatives as Plasmodium falciparum Hsp90 inhibitors
- Authors: Umumararungu, Théoneste
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/717 , vital:19984
- Description: In this research project, we have synthesized a series of nine dimethyl ether resorcinol analogues of NMS-E973 (L-1) 38, a potent Hsp90 inhibitor. These analogues were chosen because they share the same pharmacophore with NMS-E973 (L-1) 38 and were thus expected to have a similar biological activity. Moreover, it is generally easier to synthesize the dimethyl ether resorcinol analogues of NMS-E973 (L-1) 38 as compared to their demethylated counterparts. Since other Hsp90 inhibitors such as geldanamycin 19 have demonstrated anti-plasmodial activity, we also expected our compounds to be Hsp90 inhibitors and to possess anti-plasmodial activity. However, our compounds were tested for growth inhibitory activity of Plasmodium falciparum and not for P. falciparum Hsp90 (PfHSP90) inhibitory activity. The synthesis involved a series of steps that led to the formation of the ester compound TU-011 (L-7) 43 that was then used as a precursor for different NMS-E973 (L-1) 38 analogues. The choice of analogues to be synthesized was dictated by binding affinity predictions obtained from molecular docking. The chosen synthetic analogues were active against chloroquine-sensitive Plasmodium falciparum (3D7 strain) in a Plasmodium lactate dehydrogenase assay and they were not generally cytotoxic to human cervical adenocarcinoma cell line HeLa. The most active of our compounds was TU-018 (L-103) 50 with an IC50 value of approximately 1.830 µM as compared to the standard, chloroquine, with an IC50 value of 0.01062 µM. Some of the compounds showed mild cytotoxicity towards HeLa cells with IC50 values higher than 25 µM as compared to the standard apoptosis inducer drug, emetine that had an IC50 value of 0.09948 µM. These results highlight the fact that the synthesized analogues are novel relatively non-toxic anti-plasmodial agents.
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- Date Issued: 2016
Synthesis of chiral ketopinic acid-derived catalysts and their evaluation in asymmetric transformations
- Authors: Hassan, Yusuf
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/550 , vital:19969
- Description: Four new (+)-ketopinic acid-derived Mn(III) complexes, three of which possess pseudo C2- symmetry, were synthesised as chiral catalyst candidates. The ligands were prepared by refluxing (+)-ketopinic acid with ethane-1,2-diamine, the resolved (R,R)- and (S,S)-1,2-diaminocyclohexanes, and 1,2-diaminobenzene in chloroform. Treatment of the ligands with manganese(II) acetate tetrahydrate in refluxing ethanol afforded the respective complexes as brown amorphous powders. Characterisation of the ligands and the corresponding complexes was achieved using 1-D and 2-D NMR, IR spectroscopy, and elemental analysis. Various homogeneous asymmetric transformations, were investigated using these four complexes, viz., aldol, and Baylis-Hillman reactions, aza-Michael addition of piperidine to the Baylis-Hillman adducts, epoxidation, and ketone and imine reduction. Asymmetric aldol reactions of benzaldehyde with the aryl ketones, acetophenone, propiophenone, -tetralone, 4-nitroacetophenone, and 4-methoxyacetophenone, conducted in the presence of 10 mole % of the chiral catalysts, afforded enantioselectivities of up to 99% e.e. Asymmetric Baylis-Hillman reactions of methyl- and tert-butyl acrylates with pyridine-2- carbaldehyde, 6-methylpyridine-2-carbaldehyde, 5-chlorosalicylaldehyde, benzaldehyde, 4-chlorobenzaldehyde, and 2-nitrobenzaldehyde were conducted in the presence of catalyst 139 (10 mole %) to afford enantioselectivities of up to 44% e.e. Aza-Michael addition of piperidine to racemic Baylis- Hillman adducts in the presence of the catalyst 139 (10 mole %) was found to proceed with diastereoselectivities of up to 91% d.e. Asymmetric epoxidation of trans-methyl styrene, styrene, trans-stilbene, cis-stilbene, and indene, using a 5 mole % chiral catalyst loading and m-CPBA as the oxygen source, gave enantioselectivities of up to 32 % e.e. Asymmetric reductions of acetophenone, 3-chloropropiophenone, 4-hydroxyacetophenone, -tetralone, and 2-hydroxy-1-acetonapthone were investigated using NaBH4 as the reducing agent and a 10 mole % loading of the chiral catalysts. A stereoselectivity of 68% e.e. was obtained in the reduction of acetophenone, but attempts to reduce the selected imines to the corresponding chiral amines proved to be unsuccessful — even in the absence of the catalysts. It thus became apparent that the catalytic version of the reaction was not feasible.
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- Date Issued: 2016
Teaching for criticality: an analysis of the current status at two teacher education colleges in Zimbabwe
- Authors: Manyumwa, Canisius
- Date: 2016
- Subjects: Critical pedagogy -- Zimbabwe , Teachers colleges -- Zimbabwe , Teachers -- Training of -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/8119 , vital:25016
- Description: The education system in Zimbabwe is an adoption and adaptation of former colonial education that ended in 1980 with the attainment of independence. However, much of the ethos and practices of colonial education appear to have defied the transition, resulting in a transmission-based education system that is averse to critical thinking and critical pedagogy. This research study sought to find out the level of criticality at selected Zimbabwe teacher education colleges and to suggest ways of improving the development of this criticality. The study was a critical social research, situated in the transformative paradigm of qualitative research. I adopted a multi-site case study approach where focus group discussion and document analysis techniques were used in data generation at two teacher education colleges. The sample for the study comprised six (6) and seven (7) members of the Theory of Education department teaching staff at the respective institutions who volunteered to take part in the focus group discussions. The study used Antonio Gramsci’s ‘cultural hegemony’ and Malewski and Jaramillo’s ‘epistemologies of ignorance’ as its theoretical framework. The main findings were that there were very low levels of criticality in the teacher education programme because critical thinking and critical pedagogy were generally viewed negatively in the institutions. The key operational documents in the programme, the syllabus and the examination question papers did not reflect any meaningful critical thinking or critical pedagogy concepts or demands. Research participants turned out to have a very inadequate understanding of critical thinking and critical pedagogy. In addition, they blamed the failure to teach critical thinking skills on shortage of time and the large numbers of students on the teacher education programme. From analysis, both of these reasons were not convincing. From the findings in the study, I recommended a nationwide campaign to raise teacher educators’ awareness of the nature and value of developing criticality. I also recommended some formal educational programmes for key players in the teacher education system that can help advance their understanding of critical thinking and critical pedagogy. Critical thinking and critical pedagogy should be substantively included on the teacher education syllabi and examinations. Teacher education, and all other sectors of education, should go beyond just teaching criticality skills to learners. Educators need to be able to use such skills themselves in their teaching and in their own lives. My suggested framework for the inclusion of criticality in education can be used as a way of ensuring that criticality is developed and catches appeal across the country.
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- Date Issued: 2016
The chemistry of Algoa Bay ascidians
- Authors: Bromley, Candice Leigh
- Date: 2016
- Subjects: Sea squirts -- South Africa -- Algoa Bay , Marine metabolites , Chemistry, Analytic , Liquid chromatography , Inductively coupled plasma mass spectrometry , Metal ions , Nucleosides , Vanadium
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4560 , http://hdl.handle.net/10962/d1020606
- Description: This thesis investigates the chemistry of 25 ascidian species collected from Algoa Bay, South Africa with a concerted focus on metal accumulation by these ascidians and the possible interaction of these metals with ascidian metabolites. Chapter 2 details the screening techniques employed to establish the presence of nitrogenous metabolites (1H- 15N HMBC), hyper-accumulated metal ions (ICP-MS) and potential metal ion/ ascidian metabolite complexes (LC-ICP-MS/ESI-MS). Unfortunately, exhaustive attempts to detect intact metal ion/ascidian metabolite complexes through the use of liquid chromatography with parallel inductively coupled plasma mass spectrometry/electrospray mass spectrometry (LC-ICPMS/ ESI-MS) were unsuccessful. However, the LC-ICP-MS/ESI-MS data obtained for the crude organic extracts of six of the Algoa Bay ascidian species, Distaplia skoogi, Aplidium monile, Aplidium sp., Didemnum sp., Leptoclindines sp. and Polycitor sp. enabled identification of a number of ten halogenated metabolites, namely the indoles 2.28-2.30, and the tyramine and tyrosine derivatives (2.31-2.33, 2.41, 2.43, 2.44 and 2.46), within the ascidian extracts. This study confirmed that LC-ICP-MS/ESI-MS is a powerful tool for the dereplication of halogenated metabolites in complex mixtures especially where these compounds are present in very small amounts. This study is also the first report of these compounds (eight of which are known) in African ascidians. Compounds 2.32 and 2.46 have not been reported before from a marine source. Compounds 2.28-2.30 and 2.33 were present in sufficient amounts in the respective ascidian extracts to allow their isolation and structure elucidation using standard spectroscopic techniques Chapter 3 explores the ability of ascidians to accumulate a wide range of metal ions at concentrations which are often orders of magnitude higher than those of the surrounding sea water. Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the total ion concentrations of 24 metals in 25 Algoa Bay ascidian species. To the best of our knowledge this is the largest and most extensive investigation of metal concentrations in a group of different ascidians occurring in the same area. Hypotheisizing that the metal ion concentrations for each ascidian specimen screened may represent a unique fingerprint for each specimen principal component analysis (PCA) was used in an attempt to establish whether there were spatial, temporal or phylogenetic relationships associated with the metal concentration fingerprints of the ascidians that formed part of this study. The PCA results showed that there were no statistically significant relationships between ascidian metal ion concentrations and either the collection year or the collection site of the ascidians. However, species from the family Didemnidae provided the clearest statistical evidence supporting a phylogenetic relationship between these ascidians and their hyperaccumulated metal ion profiles. Furthermore, these results suggested that ascidian species are indeed actively concentrating metal ions from the surrounding sea water and are not simply sinks for passively accumulated metal ions. Interestingly, the concentration of vanadium in the set of ascidians studied did not appear to correlate with any of the other metals accumulated by these ascidians suggesting that there is possibly a unique method employed for the accumulation of vanadium by ascidians. Chapter 4 investigated this possibility further after the nucleosides 4.10, 4.11, 4.13, 4.15, 4.17 and 4.40 were isolated from the vanadium accumulating ascidian Aplidium monile. Studies into the interactions between nucleosides and vanadyl are unfortunately rare and usually qualitative in nature with limited information provided about the stability or structures of the complexes formed. The vanadyl accumulating aplousobranch ascidians e.g. Aplidium monile dominated our study of Algoa Bay ascidians therefore providing us with the rationale to investigate the relatively little studied binding ability and stability of vandyl-nucleoside complexes. Potentiometric studies were conducted to determine the stability constants of complexes formed between the oxovanadium ion vanadyl (VO2+) and the commercially available nucleosides 4.10-4.14. The data afforded by this analysis clearly confirmed the complexity of the vanadyl/nucleoside complexation and suggested that guanosine (4.12) formed the most stable complex with oxovanadium ions. We were also able to establish a third protonation constant for the hydroxyl moiety in 4.12 with a logK 8.87 which has not been previously reported. Finally, Chapter 5 revisited the cytoxicity two Algoa Bay ascidians, Clavelina sp. and Atriolum marinense the extracts from which produced promising bioactivity results in previous studies against oesophageal cancer cells. The HP-20 fractionated extracts of Clavelina sp. and Atriolum marinense proved to be similalrly cytotoxic to breast cancer cells. With the exception for the 100% acetone(aq)fractions the NMR data for both species suggested that most active non polar fractions were dominated by what appeared to be structurally unremarkable fatty acid glycerides and as such were not pursued further. Purification of the 100% acetone(aq)fraction of A. marinense resulted in the isolation of a styrene trimer, 5.1, common to both ascidian extracts. The NMR simulation software WIN-DAISY was employed to confirm the structure of 5.1. Attempts to establish if 5.1 was an isolation artefact or a product of marine pollution were inconclusive
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- Date Issued: 2016
The Contribution of fruit from trees to improve household nutritional security in the context of deforestation in Cameroon
- Authors: Tata epse Ngome, Precillia Ijang
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/793 , vital:19991
- Description: Cameroon needs healthy citizens to archive emergence by 2035. Malnutrition and undernourishment is the highest burden in the World in recent times and a silent crisis facing most rural communities in forest areas of Cameroon. Its abstruseness makes extremely fragile political, social and economic planning to foster development in such areas. Therefore, it is time we bring appropriate understanding and new strategies on unpacking the complexities of food and nutritional security and define practical solutions to food insecurity. Working in the context of increasing deforestation, this thesis brings evidence on the situation of household food insecurity (FIS) access experience in forest areas which is not reported in current discussions at the national level. It further investigates the knowledge and awareness of households on the availability, accessibility, utilisation, vulnerability and consumption of nutrient rich food items using the example of fruits from trees. Thus, the aim of this research was to investigate strategies for addressing household FIS through increased domestic supply and consumption of fruits from trees in the context of deforestation in Cameroon. Data were collected through four rounds of structured interviews completed between August 2013 and October 2014. Analysis was done using simple citations and ordering, Principal Component Analysis (PCA), Likert scale, χ2-test of association and Cramer's V coefficient to test the strength of the association and means and ANOVA. The HFIAS approach used to determine household FIS. Only 1% of the population were food secure and the moderately deforested zone showed the worst trends in food insecurity. Therefore, the effect of deforestation was nuanced. Diverse fruit trees were registered. Households said they required fruits only 2.4 ± 1.5 times per week. Recently, the intake of 400 g of fruit per person per day for good health was announced as a priority of international recognition. However, households were not aware of the importance and frequency of fruit consumption with less than 50% of households eating fruits daily during the harvesting season. Fruit tree nurseries where scarce and seeds where obtained from local sources. Fruit tree diseases where rampant and up to 50% harvest lost was registered for some fruits species. This study has shown that food availability does not necessarily mean adequate food intake. Three opinions about fruit trees and the prevalence of food insecurity in Cameroon has been raised in this thesis. First, there is ineffectiveness in the eradication of FIS because even in agricultural conducive environments, hunger and food insecurity are still prevalent at high rates. Therefore, effective and efficient targeting of food insecured groups need to be promoted in all clusters of the population. Secondly, the national nutrition program is neglecting sensitisation on food consumption patterns and therefore people are not making use of nutrient rich foods even when this maybe found around their environments - taking the case of fruits from trees. Thus, very few people ate fruits and at irregular frequencies of consumption. Thus, there is need to design special campaign programs to promote the consumption of fruits from trees. Thirdly, the word-of-mouth or neighbour-to-neighbour dissemination approach on fruit trees planting has not been efficient across communities. As such nurseries where scarce and people obtained fruit trees plants from natural regeneration or found them on the field when establishing the field. Therefore, in this research, it is postulated that no matter the nature of efforts and level of intervention, what is certain is that addressing FIS requires effective targeting of the vulnerable population and the implementation of novel and practical approaches on promoting access to and consumption of fruits in the right frequencies. This research further revealed that poor eating habits was a problem and lack of knowledge about the frequency and intake of nutrient rich food was serious. For instance, people were not aware on the recommended frequency of fruit consumption and people ate infested fruit while reserving the healthy ones for sale. This is the trap of the food insecurity problem in some regions – knowledge about foods and ways of food utilisation. This is neither a problem of availability nor accessibility, but rather a problem of lack of knowledge and lack of sensitisation. From FAO reports on the state of food insecurity in the world and other studies of food intake in most developing nation, poor food consumption is a global problem in most poor regions and even in rich areas affected by obesity. Thus, there is a need to establish a high level policy framework maybe in the form of a convention or an intergovernmental panel at the level of the United Nations and/or the African Union on ‘reducing malnutrition in all its forms (rates, drivers and consequences on human health and the environment)’. This structure will promote setting priorities, strategies, monitoring on peoples eating habits, setting nutritional standards, and principles and indicators for observing under nutrition, over nutrition and associated problems within all population strata.
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- Date Issued: 2016
The development of a discovery and control environment for networked audio devices based on a study of current audio control protocols
- Authors: Eales, Andrew Arnold
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/539 , vital:19968
- Description: This dissertation develops a standard device model for networked audio devices and introduces a novel discovery and control environment that uses the developed device model. The proposed standard device model is derived from a study of current audio control protocols. Both the functional capabilities and design principles of audio control protocols are investigated with an emphasis on Open Sound Control, SNMP and IEC-62379, AES64, CopperLan and UPnP. An abstract model of networked audio devices is developed, and the model is implemented in each of the previously mentioned control protocols. This model is also used within a novel discovery and control environment designed around a distributed associative memory termed an object space. This environment challenges the accepted notions of the functionality provided by a control protocol. The study concludes by comparing the salient features of the different control protocols encountered in this study. Different approaches to control protocol design are considered, and several design heuristics for control protocols are proposed.
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- Date Issued: 2016
The development of trilingual literacy in primary schools in Kenya
- Authors: Mose, Peter N
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/815 , vital:19993
- Description: The Kenyan language in education policy contemplates development of trilingual literacy skills in pupils by the end of standard three. The purpose of this study was to determine to what extent standard three pupils were literate in their mother tongue (Ekegusii), Kiswahili, and English. The study was undertaken in the context of; a language in education policy that provides for the use of mother tongues and Kiswahili (as languages of instruction) in rural and urban schools respectively up to the end of standard three, followed by a transition to an English medium from standard four; a general negative public attitude towards mother tongue instruction; and substantial empirical evidence in support of mother tongue instruction in basic education. Cummins’ Linguistic Interdependence and Linguistic Threshold Hypotheses guided the study. Adopting a mixed methods approach, the study used direct classroom observations, face-to-face interviews, document analyses, and reading tests to obtain data. Thematic, content, and statistical approaches were used in data analysis. It was found that various stakeholders understand key aspects of the language in education policy differently. Secondly, efforts in mother tongue instruction in schools are not motivated by theoretical and empirical foundations; development efforts are hence ineffective and inadequate leaving majority of learners with below average literacy skills in their mother tongue by the end of standard three. Thirdly, teachers do not implement the language in education policy as spelt out in the relevant documents; the three languages have therefore been allocated various classroom functions. Fourthly, the factors that motivate the disregard of the language policy include the language of examinations and textbooks, and transition to standard four in which English is the language of instruction. Lastly, reading scores indicate that majority of pupils transiting to standard four do not possess adequate reading skills to enable them read to learn in a mother tongue, Kiswahili, and English. This is observed across rural, peri-urban, and urban schools. The study recommends that: The ministry of education conducts workshops to re-educate the relevant stakeholders on the meaning and significance of the language in education policy and the significance of mother tongue instruction in second language, literacy, and skill development. This should be followed by a re-classification of primary schools on the basis of linguistic homogeneity, or otherwise, to ensure the intention of the policy is achieved. This could include empowering individual schools to determine language of instruction in lower primary based on language predominance. Secondly, the ministry should provide relevant resources for mother tongues and Kiswahili to develop them as effective languages of instruction as recommended by various past education commission reports. Additionally, a bilingual course in teacher training colleges to equip primary school teachers for bilingualism and biliteracy development should be introduced; one implication of this is teachers giving notes and tests in the languages spelt out in the policy. Thirdly, the ministry should intensify inspection of schools to assess implementation of the policy. Fourthly, future studies should assess mother tongue literacies as well, since they determine the extent and success of second language acquisition and learning; and measures should be put to ensure English is adequately resourced and taught well. Finally, mother tongue instruction should be extended up to, at least, standard five.
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- Date Issued: 2016
The ecology of hard substrate communities around Sardinia Bay in the warm-temperate Agulhas Bioregion
- Authors: Evans, Adrian G , Nel, Ronel
- Date: 2016
- Subjects: Aquatic biodiversity -- South Africa -- Nelson Mandela Bay Municipality , Marine ecology -- South Africa -- Nelson Mandela Bay Municipality , Seashore biology -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/6782 , vital:21141
- Description: Hard substrates in the marine environment are an important ecosystem of great scientific and economic value. Hard substrates provide suitable habitat for a diverse assemblage of benthic organisms. This thesis investigated the ecology of benthic hard substrate communities along a section of wave-exposed coastline, including the Sardinia Bay Marine Protected Area (MPA), in the warm-temperate Agulhas bioregion of South Africa. The effect of physical variables on benthic communities, including both the intertidal and shallow subtidal, was quantitatively assessed across (Chapter 3) and along (Chapter 4) the shore to provide a model of zonation for this bioregion and a baseline of community patters and biodiversity, as this information was lacking especially for the Sardinia Bay MPA. The zones described in Chapter 3 were in agreement with previous trends described for this bioregion with the addition of different biotopes in the upper Balanoid and deeper subtidal zones as well as the addition of an intermediate/transition zone in the subtidal between the algal dominated shallow subtidal and deeper subtidal, which has an increased abundance of sessile invertebrates. Disturbance is an important process in structuring benthic communities, and its role in structuring shallow benthic communities was investigated using a disturbance simulation experiment across a wave-exposure gradient (Chapter 5). Communities were found to change along the exposure gradient and monitoring the undisturbed communities showed that large waves caused disturbances across all the exposures. The recovery process was similar across all exposures mainly through lateral vegetative growth and regrowth from basal parts with communities in disturbed quadrats recovering to resemble the surrounding undisturbed community. Recruitment did not have a significant effect in the recovery process and community composition was therefore a result of the effects of the physical environment along the exposure gradient. Lastly this thesis investigated the indirect effects of protection in the small Sardinia Bay MPA (Chapter 6). Despite the small size of the MPA this study found differences in diversity and abundance between communities inside and outside the MPA. These differences in benthic biota infer indirect effects of protection that are probably due to the increase in abundance of exploited fish inside the MPA. Lower abundances of red algae, macroinvertebrates and diversity inside the MPA in the shallow depth category was attributed to the higher abundance of the generalist fish species that concentrate in the shallows. Significantly lower abundances of Chordata in the shallow and medium depth categories inside the MPA was attributed to predation by the benthic carnivorous species as ascidians are included in the diet of these species. This chapter also compared the effectiveness of destructive (scraped quadrats) and non-destructive (visually assessed quadrats) sampling methods. Scraped quadrats were found to be more effective in detecting changes across the MPA compared to visually assessed quadrats. Destructive methods sample the entire assemblage, to a higher taxonomic level, and measure abundance using biomass. It was concluded that biomass is a better metric when comparing communities across protection or other treatments as it provides better biological information of the community.
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- Date Issued: 2016
The effect of different land uses on household livelihoods in Tale Ga-Morudu Communal Property Association
- Authors: Ramaloko, Thomas Tshwantshi
- Date: 2016
- Subjects: Land use -- South Africa -- Limpopo Reparations for historical injustices -- South Africa -- Limpopo
- Language: English
- Type: Thesis , Masters , PhD
- Identifier: http://hdl.handle.net/10948/14146 , vital:27436
- Description: This study is about a population of 235 households in Blouberg municipality, Limpopo Province, that constituted itself in 2004 into a Communal Property Association. The Tale Ga-Morudu CPA was formed in order to own, manage and control a total of seventeen farms which were progressively restituted to them during 2004 by the Commission on Restitution of Land Rights. Tale Ga-Morudu households were dispossessed and forcefully removed from a number of fertile, arable and irrigable farms1in the 1960s due to racially discriminatory laws or practices. These households were then relocated by the then apartheid regime on the eastern part of Mogalakwena River. They were distributed in the arid communal areas of Laanglagte/Vergelegen, Matekereng; Ga- Mankgodi; Letswatla and Mamoleka under the traditional leadership of Kgoshi Maleboho of BabinaTšhwene. (Map one). It is the aim of this study to find out how Tale Ga-Morudu CPA currently uses these restituted farms for the households who have said to have benefited from restituted land. The researcher used his own observations, lessons and analysis of perspectives from case studies conducted from Limpopo in order to pursue this aim. This study adopted a descriptive household survey design that used a predominantly quantitative approach, and the use of qualitative methods to complement contextual details. A quantitative questionnaire was used on a sample unit of (20%) 45 households obtained by simple random sampling from a population of 235 households of the CPA. Other qualitative methods include focus group discussion, document review and observation. From the results it is clear that land claimants, prefer to retain existing practices of land use, than risk changes in land use in order to meet their socio-economic needs. Thus, instead of investing in commercial agriculture or wildlife farming, people follow subsistence agriculture and remain dependent on social grants and pensions for their livelihood. The general study findings show that the CPA planned to implement different types of land use including those of direct land use value. These include food gardens, resettlement; game farming; poultry enterprises and livestock grazing, and also of indirect use value. The latter refers to contract crop cultivation, rentals and strategic partnerships. The study found that despite income being generated from indirect types of land use, the majority of these intended beneficiaries never benefited from accrued financial dividends of land rental and development. However, households were still able to take advantage of employment opportunities created by contract crop cultivation and in the process they acquired crop cultivation skills. Furthermore the harvesting of natural resources such as wood and poles also contribute to the wellness of households. Households, also derived cultural wellness and a sense of satisfaction by accessing their restored farms to perform rituals. The general conclusion of the study is that the CPA is underutilizing its properties, including arable and irrigable fields, rentable recreational facilities, game farming and its tourism potential.
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- Date Issued: 2016
The effect of kelp supplementation in formulated feed on the production performance and gut microbiota of South African abalone (Haliotis midae)
- Authors: Nel, Aldi
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/899 , vital:20001
- Description: Formulated feeds with a relatively low (< 5 % of dry mass) kelp (Ecklonia maxima) inclusion level are widely used on commercial abalone (Haliotis midae) farms in South Africa. Although the use of kelp, a major constituent of the natural diet of H. midae, as a dietary supplement is considered to enhance abalone growth and feed utilisation, there are no published studies which quantify the effects of kelp inclusion in formulated feeds. Furthermore, the physiological mechanisms by which kelp supplementation may positively influence abalone digestive physiology and growth are largely unknown. As the kelp supplement is comprised mostly of soluble fibres and abalone gut bacteria associated with macroalgae (and its fibrous polysaccharides) are known to play a key role in digestion, it was hypothesised that the kelp supplement influences the gut-bacterial community profiles of cultured abalone through prebiotic and other metabolic effects. The present thesis thus examined the effect of kelp supplementation on the performance of abalone (Haliotis midae) fed formulated feeds and explored the influence of a kelp supplement on the abalone gut microbiota and its function in the gastrointestinal tract. The key hypotheses of the study were that kelp supplementation in formulated feed: 1) enhances abalone growth; 2) causes a shift in abalone gut-bacterial community composition through a prebiotic-like effect; 3) may induce changes in crop morphology as a result of potential bacterial-associated increases in volatile short-chain fatty acids, and 4) alters digestive enzyme activities in the abalone gut through changes in bacterial-derived (exogenous) digestive enzymes. The growth-promoting efficacy of low-level kelp supplementation was tested by feeding isonitrogenous and isoenergetic experimental feeds containing 0.00 – 3.54 % kelp (dry mass) to sub-adult abalone (~43 mm shell length) for eight months under commercial farm conditions. The growth trial established that kelp supplementation (0.44 – 3.54 % of dry mass) promoted faster growth and improved feed conversion and protein efficiency ratios in cultured abalone compared to abalone fed the non-supplemented control diet, while there were no significant differences in growth for abalone fed the different kelp-supplemented diets (0.44, 0.88, 1.76 and 3.54 % of dry mass). Feed conversion and protein efficiency ratios displayed significant correlations with kelp level in the range of 0.00 – 3.54 % dry mass, and it is therefore recommended that kelp be included in the formulated feeds of cultured South African abalone at a rate of up to 3.54 % of dry mass. A kelp-supplemented (0.88 % dry weight inclusion) feed was fed to abalone under farm conditions to compare gut physiological parameters (crop morphology, digestive enzyme activities and the gut microbiota) in abalone against that of abalone fed an isonitrogenous and isoenergetic non-supplemented control feed. To establish if the observed higher abalone growth rates were related to improved gastrointestinal tract epithelium activity and integrity, as reflected by epithelial cell growth in response to potential changes in bacterial-derived short-chain fatty acid production, crop epithelial morphology was compared between abalone fed the kelp-supplemented and control feeds. Kelp supplementation did not induce any observable changes in crop epithelial cell height for farm-reared sub-adult abalone fed the experimental diets on-farm for seven weeks. This was attributed to the similar macronutrient compositions of kelp-supplemented and control diets and/ or the common diet history of experimental abalone from weaning to the initiation of the experiment. Digestive enzyme activity was compared between abalone fed a kelp-supplemented and a control feed during an on-farm feeding trial with sub-adult abalone. Gut samples were collected after seven weeks and colorimetric enzyme assays were performed for the polysaccharide-degrading enzymes amylase, alginate lyase, laminarinase and fucoidanase, and for acid protease, trypsin and chymotrypsin activity. Amylase and alginate lyase activities were relatively high, compared to the other enzymes. Polysaccharidase and acid protease activity levels did not differ significantly between abalone fed kelp-supplemented and control feeds, but a greater variability in enzyme activity levels was observed in abalone fed the control diet. It was hypothesised that this might be due to the kelp supplement promoting a more stable and less opportunistic gut-bacterial community than the control diet. Pooled gut samples of abalone fed the kelp-supplemented diet were used for proteomic analyses to identify the composition of enzyme proteins of both endogenous and exogenous origin in the abalone digestive system. The key polysaccharidases and proteases in the gut samples of kelp-supplemented formulated feed-fed abalone were all of abalone origin, whereas the bacterial enzymes were of the types that form part of intermediate reactions in metabolic pathways. The results suggested that bacterial enzymes play a different role to abalone endogenous enzymes in the digestion of formulated feed. While abalone enzymes appear to be the main degraders of carbohydrate and protein macromolecules, the profile of exogenous enzymes suggests that they perform bioconversions of smaller organic compounds. The profiles of gut-bacterial communities of farm-reared sub-adult abalone fed kelpsupplemented and control feeds on-farm for seven weeks were analysed with metagenomic pyrosequencing and DGGE analyses, using 16S rDNA-targeted amplified DNA. The results indicated a shift in gut-bacterial composition with a higher abundance of Mollicutes in abalone fed kelp-supplemented feed compared to those fed the control feed. DGGE band patterns displayed a greater within-group similarity in gut bacteria for abalone fed the kelpsupplemented diet and the presence of unique and variable bands for bacteria in the guts of abalone fed the control diet. It was concluded that when cultured abalone are fed kelpsupplemented formulated feeds, more stable gut bacterial communities are present compared to a more opportunistic gut-bacterial community in abalone fed non-supplemented feeds, and that the observed increase in Mollicutes could reflect the restoration of the abalone gut microbiota to a more natural state. The novel application of proteomics to abalone nutrition in the present study demonstrated that gut-bacterial enzymes may form part of many different metabolic pathways and suggests that the metabolism of the gut microbiota serves as an extension of the abalone’s digestive metabolism. Future studies should quantify the contribution of commensal gut-bacteria to cultured abalone nutrition by employing metabolomic studies to characterize the utilisation of bacterial-derived metabolites by the abalone host.
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- Date Issued: 2016
The effect of shaped nanoparticles on the photophysicochemical behaviour of metallophthalocyanines
- Authors: D'Souza, Sarah
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/529 , vital:19967
- Description: The synthesis, spectroscopic characterization and photophysicochemical analysis of novel and known metallophthalocyanines are reported in this thesis. The novel lowsymmetry compounds were extensively studied. Selected phthalocyanines were conjugated to a variety of nanoparticles consisting of silver (AgNPs), gold (AuNPs) and zinc oxide (ZnO NPs) in order to improve their photophysical and photochemical behaviour. As with the phthalocyanines, the nanoparticles and phthalocyaninenanoparticle conjugates were thoroughly investigated. Research on the effect of the solvent used, as well as the influence of nanoparticle composition and shape on the properties of the phthalocyanines, were performed. The findings showed that there was a general increase in triplet quantum yields of the phthalocyanines in the presence of the nanoparticles. It was also noted that the use of different solvents directly affected the photophysicochemical properties. In the case of the nanoparticle conjugates, photophysical and photochemical changes were observed. Of significance were the gold nanostars, which decreased the degree of phthalocyanine aggregation in water, resulting in increased fluorescence lifetimes. The studies also revealed that the effect of the nanoparticle shape on the phthalocyanine properties was highly dependent on the nanoparticle material. The photodynamic antimicrobial activity of selected phthalocyanine-zinc oxide nanoparticle conjugates was investigated against Staphylococcus aureus (S. aureus) in solution. The phthalocyanines alone exhibited remarkable growth inhibition, however the presence of the nanoparticles in the conjugates increased the photoinactivation of S. aureus.
- Full Text:
- Date Issued: 2016
The effect of silica on the reduction of precipitated iron-based fischer-tropsch catalysts
- Authors: Coombes, Matthew
- Date: 2016
- Subjects: Fischer-Tropsch process Reduction (Chemistry) , Catalysts
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/14873 , vital:27888
- Description: Iron Fischer-Tropsch (FT) catalysts are typically prepared as iron oxides which are reduced to FT-active iron metal and iron carbide prior to FT synthesis. The iron oxides contain a variety of different chemical and structural promoters to alter FT-activity. Silica is a common structural promoter which stabilises the formation of small crystallites and provides mechanical integrity to the catalyst. However, silica inhibits the reduction of the oxide precursor to the FT-active phases. This ultimately affects catalyst activity and product selectivity. It has been proposed that the silica interacts with the iron to form encapsulating shells of fayalite (Fe2SiO4), or fayalite rafts between the iron oxide and the silica support. In this study, six silica-promoted iron oxide samples were prepared using a simple co-precipitation technique. Samples contain varying amounts of silica, and the samples are named 100/x Fe/SiO2, where x is the weight of silica for 100 weight iron, with x taking on values of 0, 10, 25, 50, 100 and 200. The resulting iron oxides were characterised using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRPD), M¨ossbauer spectroscopy (MS), magnetic susceptibility measurements (MM), Raman spectroscopy, thermal gravimetric analysis (TGA) and nitrogen physisorption. Their reduction in a hydrogen atmosphere was investigated using temperature programmed reduction (TPR), in situ XRPD and TEM. The reduction in hydrogen of 100/0 Fe/SiO2 and 100/10 Fe/SiO2 was also studied using in situ gas flow TEM cells. These cells allow the samples to be studied in the electron microscope at temperature and pressure conditions approaching those experienced in a real reactor environment. In the absence of a silica promoter (100/0 Fe/SiO2), hematite particles are formed with mean particle diameters of 39 ± 12 and 52.7 ± 0.2 nm determined using TEM and XRPD respectively. MM data reveals a magnetic transition (Morin transition) at≈230 K, consistent with a mean particle size of≈50 nm. In a hydrogen atmosphere, the hematite reduces to metallic iron via a two-step process viz. hematite → magnetite → iron. The final iron particles have an average crystallite size of 68.0 ± 0.2 nm. The presence of lower amounts of silica in the samples 100/10 Fe/SiO2, 100/25 Fe/SiO2 and 100/50 Fe/SiO2 results in the formation of silicasubstituted 2-line ferrihydrite particles. Bands in the Raman spectra of these samples shift on increasing silica content, which indicates an increasing number of Fe-O-Si bonds within the ferrihydrite framework. MM reveals typical superparamagnetic (SPM) behaviour above a blocking temperature in the range 39 - 68 K which gives mean particle sizes of 4.2, 3.6 and 3.5 nm for 100/10 Fe/SiO2, 100/25 Fe/SiO2 and 100/50 Fe/SiO2 respectively, in good agreement with particle sizes determined using TEM (3.1±0.4, 2.4±0.3 and 2.4±0.3 nm respectively). MS data at 300 K and 4.2 K were fitted with distributions of ∆EQ and Bhf respectively. The median values of Bhf decrease with increasing silica content, indicating greater degrees of distortion in the Fe3+ environments induced by increased silica substitution. The reduction to metallic iron occurs via a three-step process viz. hematite → magnetite → wu¨stite → iron, with the silica stabilising the wu¨stite phase. The increasing amount of Fe-O-Si bonds on increasing silica content shifts reduction to higher temperatures broadens each reduction step as a result of local Fe-O-Si concentration variations. Fractions of each sample are not completely reduced even at 1000°C, with the relative proportion increasing with increasing silica content. In situ gas flow TEM studies reveal that the mechanism of reduction involves the liberation of atomic iron atoms from the silica-substituted iron oxides which agglomerate and grow into final iron particles. This leaves a poorly crystalline Fe-O-Si bonded framework behind. STEM-EDS and STEM-EELS reveal low concentrations of silicon at the surface of the resulting iron particles, however they do not form encapsulating shells of fayalite as previously suggested. The majority of the silica remains in the Fe-O-Si material which may crystallise into separate fayalite particles at elevated temperature. The presence of silica in high proportions (100/100 Fe/SiO2 and 100/200 Fe/SiO2) results in the formation of a two-phase system consisting of silicasubstituted 2-line ferrihydrite particles which are encapsulated in an ironinfused amorphous silica network. As with the other silica-bearing samples, there is an increase in Fe-O-Si bonds and an increase in the degree of distortion at Fe3+ sites with increasing silica content. The large amount of silica suppresses the blocking temperature of the SPM crystallites. In a hydrogen atmosphere, the reduction to metallic iron follows the same three step process as the other silica-bearing samples. Reduction temperatures are further shifted to higher values and given reduction steps are considerably broader with increasing silica content. The fraction of iron not fully reduced also increases. Iron particle diameters are very small, since encapsulation by the silica matrix prevents growth of particles.
- Full Text:
- Date Issued: 2016
The effects of a gradual shift rotation and a split shift nap intervention on cognitive, physiological and subjective responses under simulated night shift settings
- Authors: Davy, Jonathan Patrick
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/517 , vital:19966
- Description: Introduction: Shift work, particularly work that occurs at night has been associated with numerous challenges to occupational safety and productivity. This stems from the associated extended wakefulness, circadian disruptions and sleep loss from the inversion of the sleep wake cycle, which predisposes shift workers to reduced alertness, increased fatigue and decrements in performance capacity. These effects may be exacerbated over consecutive night shifts as a result of reductions in sleep length associated with attempting to sleep against the alerting signals of the circadian rhythm during the day. Although a variety of shift work countermeasures exist, new and innovative fatigue management strategies are needed to mitigate the effects of night work. This study proposed two night shift interventions; the Rolling rotation and a split shift nap combination. Aims: The aim of this study was to explore the effects of these interventions to a conventional Fixed night shift arrangement. Selected performance, physiological and subjective measures were applied to track any effects during a five-day shift work study. Methods: The study was laboratory-based and performance was quantified through the application of computer-based perceptual, cognitive and motor tests. Student participants (24 females and 21 males) partook in the study, which adopted a nonrepeated measures design and spanned five consecutive days. During this time, participants were required to perform a simple beading task over five 8-hour shifts. Participants were split according to sex and chronotype between four independent conditions; 1. Fixed night condition required participants to complete one afternoon shift (14h00 – 22h00) and four consecutive night shifts (22h00 - 06h00) 2. Rolling rotation condition gradually “rolled” participants into the night shift by delaying the start and end of an afternoon shift by two hours each day (16h00 – 00h00, 18h00 – 02h00, 20h00 – 04h00, 22h00 – 06h00) until the times matched that of the Fixed night condition. 3. The split shift nap system was made up of two independent groups, both of which completed one afternoon (14h00 to 22h00) and four night shifts. The Nap early condition worked from 20h00 to 08h00, napping between 00h00 and 04h00, while the Nap late condition worked from 00h00 to 12h00 and napped between 04h00 and 08h00 during the night shifts. Napping, the opportunity for which was 200 minutes occurred in the laboratory, but post shift recovery sleep, for all conditions, happened outside the laboratory. During each shift, six test batteries were completed, in which the following measures were taken: 1. Performance: beading output, eye accommodation time, choice reaction time, visual vigilance, simple reaction time, processing speed and object recognition, working memory, motor response time and tracking performance. 2. Physiological: heart rate, heart rate variability (r-MSSD, normalised Low frequency power: LFnu). 3. Self-reported measures: subjective sleepiness and reported sleep length and quality while outside the laboratory. Results: Analyses revealed that: 1. Measures of beading performance, simple reaction time, vigilance and object recognition, working memory, motor response time and control, all physiological measures, except LFnu and subjective sleepiness demonstrated the effects of time of day / fatigue, irrespective of condition. 2. There was no evidence of cumulative fatigue over the four night shifts in the performance and subjective measures and most of the physiological indicators. Beading output decreased significantly over the course of the night shifts, while reported post shift sleep length was significantly reduced with the start of the night shifts, irrespective of condition. 3. The majority of the physiological and performance measures did not differ significantly between conditions. However, there were some effects: the Rolling rotation condition produced the highest beading output compared to the Nap late condition; working memory was significantly lower in the Nap late condition compared to the other conditions. Furthermore, the nap opportunity in both the Nap early and Nap late conditions reduced subjective sleepiness, while napping during the night shift reduced post shift sleep length compared to the Rolling rotation and Fixed night conditions. There was also evidence of sleep inertia following pre-post nap test comparisons, which mainly affected visual perception tasks in both nap conditions. Sleep inertia possibly also accounted for an apparent dissociation between subjective and performance measures. Conclusions: Quantifying and interpreting the effects of night shift work in a laboratory setting has limitations. These stem mainly from the limited ecological validity of the performance outcome measures adopted and the characteristics of the sample that is tested. However, in order to fully understand the efficacy of any shift work countermeasure, the laboratory setting offers a safe, controlled environment in which to do so. The conclusions should thus be considered in light of these limitations. Night shift work negatively affected all elements of human information processing. The combination of reduced physiological arousal, extended wakefulness, increased perceptions of sleepiness and reduced total sleep obtained explained these decrements in performance. While cumulative fatigue has been reported as a challenge associated with night shift work, there was no conclusive evidence of this in the current study. In the case of the Rolling rotation, the gradual introduction to the night shift delayed the inevitable reduction in alertness and performance, which limits the viability of this intervention. The inclusion of the nap interventions was associated with reduced perceptions of sleepiness, which did not translate into improved performance, relative to the Rolling rotation and Fixed night conditions. Apart from considerations of how to manage sleep inertia post nap, the split shift nap intervention can provide an alternative to conventional night shift work arrangements.
- Full Text:
- Date Issued: 2016
The effects of land use on the avifauna and its conservation in a Kenyan coastal forest ecosystem, and the significance of the Arabuko Sokoke Forest to the local community
- Authors: Chiawo, David O
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5950 , http://hdl.handle.net/10962/d1020946
- Description: This study examines the effects of land use on the bird community of Arabuko Sokoke Forest, the largest area of coastal forest remaining in East Africa and a major Important Bird Area in mainland Kenya. Bird species diversity in three land use types (primary forest, plantation and farm lands) was compared using multivariate analysis to determine the response of different feeding guilds to habitat characteristics. The effect of habitat characteristics on overall bird diversity and specific feeding guilds was tested using linear mixed models. A total of 2600 bird observations were recorded during point counts, representing 97 bird species including 25 fruit-eating birds, 17 nectar feeders; and 60 species belonging exclusively to other feeding guilds. Land use had a significant effect on overall bird diversity and abundance. The distribution of frugivorous birds was primarily influenced by the presence of fruiting trees rather than land use type, while nectarivores were significantly affected by vertical habitat heterogeneity and vegetation type. Although the distribution of insectivorous birds is influenced by many habitat factors, proximity to natural forest, habitat heterogeneity, and the presence of large trees and fruiting trees appear to be most important to this guild. The natural forest has the greatest avian diversity and a distinctive community compared to plantation and farmlands. Patterns of habitat use by birds in the area suggest that vertical vegetation heterogeneity and complexity is especially significant in sustaining diverse and abundant bird populations, if they are in close proximity to native forests. Improvement of conservation management for the plantation and farmlands is thus critical for connectivity with other remnant primary forest patches in the area. Socio-economic data was collected from 109 forest adjacent households to determine the value of the forest to the local community and their perception of conservation issues. Arabuko Sokoke Forest is important in supplementing the livelihood needs of the local community. However, the community lacks information on the forest management plan and many people have little knowledge of local birds, which could limit their capacity to participate in conservation projects. Drivers for local community participation in conservation projects are primarily a sustainable income and the fulfillment of basic household needs. Community conservation education is needed to promote local knowledge of forest biodiversity, as well as clear frameworks for the active involvement of the local community in forest management. Support of community based projects is vital to achieve both the conservation and livelihood objectives of the Arabuko Sokoke Forest management plan.
- Full Text:
- Date Issued: 2016
The effects of poor programme management coordination on the delivery of health infrastructure projects: a case of the Northern Cape
- Authors: Mabona, Lesetja Godley
- Date: 2016
- Subjects: Health facilities -- South Africa -- Northern Cape , Hospital buildings -- Maintenance and repair
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/8165 , vital:25341
- Description: The Northern Cape Department of Health (NCDoH) experiences sub-optimal programme management coordination in the delivery of health facilities. This research study aimed to determine how programme management coordination amongst the provincial office of the NCDoH, district office and the hospital that did undergo revitalisation through the Hospital Revitalisation Programme (HRP) could be improved. In order to explore the research problem the concepts of construction management and operations management were studied from which factors that impact positively and negatively on programme management coordination were extracted. A rationalist philosophical approach and subjectivist epistemology were utilised. The empirical enquiry was conducted through the case study method to obtain in-depth context of the case. The empirical evidence was obtained through a research interview guide utilising the purposive sampling strategy. The research initiated the sampling procedure by targeting the most relevant managers to the research study in the three units of analysis. A snowball approach evolved for the identification of other managers deemed relevant for purposes of this research. The thesis obtained opinions on the subject matter from managers who participated or were supposed to participate in the implementation of the delivery objectives of the administrative programmes in the NCDoH together with the objectives of the HRP. The research revealed that poor programme management coordination in the NCDoH as a result of internal competition and silo functions which prevent synergy from programme management plan development up to implementation. Furthermore, the complete building infrastructure only attains the objectives of construction management but the building infrastructure are not a complete justification for benefit realisation without the integration of operations management. The NCDoH cannot declare a successful programme management practices if it fails to realise the benefits that require integration of infrastructure and services. It is recommended that in order to attain effective programme management and realise the benefits of strategic objectives there should be a cross-functional approach from executive management which should trickle-down to the lowest level of administration. This research has developed a framework that can be useful in the integration of construction and operations management whereby infrastructure and operational services have to be delivered simultaneously in the field of programme management.
- Full Text:
- Date Issued: 2016
The gendered appropriation of the mobile phone for online health information by youths in Zimbabwean tertiary learning institutions
- Authors: Tsarwe, Stanley Zvinaiye
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/738 , vital:19986
- Description: The study uses domestication of technology and Cultural Studies theories to investigate how youth in three institutions of tertiary learning in Harare, Zimbabwe are accessing health-related information online using their smart phones. The study critically examines how youths deploy these digital media technologies to construct their identities in a context where social and political power is unevenly distributed. To understand these issues, the study uses a triangulated research design comprising a social survey, in-depth individual interviews and field observation for data collection. Results from this data gathering showed that the use of digital media technologies differ across gender, at least in terms of the distribution of online health seeking practices between male and female youths. According to the survey results, more women tend to use their mobile phones to access health-related information. Data from the individual in-depth interviews showed that the most significant site of social change (social disruption) relates to how digital media facilitates emerging new identities (i.e. identity in the broader sense as well as health-related and sexual health identities). For both young men and young women, mobile phones are used precisely for image management, peer acceptance and the desire to define respective feminities and masculinities within their social networks. Both male and female youths assert they are able to access a variety of information online, and some of this information would not easily accessible when sought from traditional structures such as their parents. This way, youth feel that digital media technologies allow them to cultivate their own preferred identities outside the purview of parental authority and social control. Drawing on postmodern literature, such emerging identities are predicated on cultural volatility, unpredictability, decentralisation and refusal to fixation and conformity to socially constructed identities about being a youth, or being a young Zimbabwean woman or man, for example. Thus, the use of mobile phones and mobile Internet by youths in Zimbabwe to access health-related information has sociopolitical significance, because it allows young people to fashion preferred identities that resists entrenched regimes of social power. For young people in Zimbabwe, online health seeking practices precisely reflects attempt towards negotiating with and circumvent the structural limitations of either an expensive health care system or the general curiosity associated with growing up. That way, it is arguable that youth use digital media technologies to help them exercise some level of social autonomy and agency in dealing with everyday life. Individual in-depth interviews demonstrated that mobile phones and mobile Internet can thus be seen as opening up more spaces for youth to learn more about issues about growing up, sexuality and adolescents that a conservative society such as Zimbabwe traditionally consider as ‘inappropriate’ for youth consumption. They argued that the inability of parents to discuss with them issues about growing up often result in them “finding out on our own” using digital media technologies to satisfy the desire to wean themselves from what they view as arbitrary and asymmetrical social power. The study demonstrated that youth use the mobile phone to challenge the social world of adults and to show resistance to it, thereby strengthening a subculture as well as constructing an identity. However, despite the positive attributes of social capital, connectivity and personalised experience afforded by the mobile phone, the mobile phone is sometimes a source of conflict in relationships between young men and women; that is, between unmarried partners. Young women reported that their boyfriends often force them to disclose who they communicate with using their mobile phones. They also reported that their boyfriends often did some random surveillance of their social media contacts and activities. Thus, whilst one of the mobile phone’s most powerful attribute is its ability to offer personalised experience, as well as offer synchronised and unlimited access to distant connections, results from in-depth interviews showed that some unwritten expectations and norms dictated that young men closely watch their ‘girlfriends’ social media activities, including their online search activities. As a result, privacy as well as the much touted relationship between mobile phone and women’s autonomy becomes contested arenas. Even at young ages, and before marriage, women are socialised to show subservience to their partners by allowing them access to their mobile phones.
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- Date Issued: 2016
The impact of government expenditure on economic growth of the economic community of West African states (ECOWAS)
- Authors: Wanjuu, Lazarus Zungwe
- Date: 2016
- Subjects: Economic development -- Africa Africa -- Economic conditions Developing countries -- Economic aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/13261 , vital:27169
- Description: Available statistics on growth trends in the Economic Community of West African States (ECOWAS) are wanting, particularly net per capita growth rates. The analysis of available data from 1970 to 2012 by this study, for instance, shows that the net real GDP growth rate for the ECOWAS is 0.52%. Only four countries had net growth rates above 1% per annum mean growth rate of ECOWAS region. At the estimated growth rate, the prospect of accelerated growth in ECOWAS is very weak. The Barro endogenous growth model states that government provision of services can generate externalities to the private productive activities. Government’s provision of productive services in ECOWAS can ensure long-run per capita output growth without the per capita growth rate running into steady state growth. However, there are divergent views as to whether government provision of services induces long run economic growth. These views are based on different schools of thought. For instance, the economic freedom school argues for minimum government involvement (small governments) to ensure economic and political freedom to induce private investors invest and encourage economic growth. The optimal government school of thought (medium size governments) argues that government spending enhances private productivity growth through the provision of infrastructure, spending on research and development, public education, sewage, other public goods and protection through functional law and order systems. The optimal school of thought also acknowledges that government expenditure can also reduce economic growth through increases in taxation. An increase in taxation reduces the returns on investment of physical and human capital and in research and development (R&D) of private firms. This thesis investigates the impact of government expenditure on the provision of public services on economic growth in ECOWAS. To assess the impact of government expenditure on the provision of services on economic growth of ECOWAS, this thesis assesses whether the size of government, government expenditure and economic institutions promoted economic growth in ECOWAS. The thesis also determines whether per capita government capital expenditure, per capita government consumption expenditure, per capita private capital stock, per capita manufacturing output, per capita services output and per capita agricultural output have any impact on per capita real GDP growth in ECOWAS. To carry out this study, data were collected from United Nations Conference on Trade and Development (UNCTAD) database and Transparency International (TI) database. The data used covered the period of 1970 – 2013. The statistical research methods applied are the time-series methods of panel unit root test, panel co-integration test, and panel regression analysis, using both panel OLS regression models and estimation and inferences in co-integrated panel data regression methods. The panel OLS regression models applied are the panel OLS regression; panel fixed effect model (FEM) regression and the panel random effect model (REM) regression. The estimation and inferences in co-integrated panel data regression models applied are panel VEC regression model, panel DOLS regression and panel FMOLS regression. The panel DOLS regression and panel FMOLS regression models do not have an intercept, unlike their pure time-series models, which have intercepted. To ensure that the parameters estimated are reliable, this thesis conducted diagnostic tests to subject the regression result to scrutiny. The estimated panel data regression using panel OLS regression, panel FEM regression and panel REM regression indicate that the results of the estimated parameters were spurious having both autocorrelations and heteroscedasticity. High values of adjusted R-squares that were approaching one and high significant values of t statistics but very low values of Durbin-Watson Statistics demonstrated the existence of heteroscedasticity and autocorrelation in residuals. The results of the diagnostic tests also show that the DOLS estimated regression model out-performed both VEC and FMOLS regression models based on both aggregate data and per capita data estimated parameters. The results of the parameter estimated using panel VEC and panel FMOLS regression models showed that both panel VEC and panel FMOLS regression models had the problems of their residuals having not only autocorrelations but heteroscedasticity. The panel DOLS regression results were satisfactory, having no multicollinearity, autocorrelations and heteroscedasticity. The estimated panel DOLS regression results were applied to test hypotheses formulated to guide this thesis. Results from panel DOLS estimated parameters show that the existing government size in ECOWAS stimulated economic growth. The results also showed that the government expenditure exhibited an inverted U-shape with respect to economic growth. The thesis also showed that existing government size in ECOWAS significantly stimulated economic growth in the region. The results of regression indicate that economic institutions contribute negatively to the economic growth of the ECOWAS. The results also established that government capital expenditure per capita has significantly engendered economic growth. Government consumption expenditure per capita stimulated economic growth. However, private capital stock per capita has not stimulated economic growth in ECOWAS. Service sector output per capita, agricultural output per capita and manufacturing output per capita stimulated significantly economic growth in the ECOWAS sub-region.
- Full Text:
- Date Issued: 2016
The implementation of the inclusive education policy in sport: a case study of four secondary schools in Masvingo District, Zimbabwe
- Authors: Mudyahoto, Tapiwa
- Date: 2016
- Subjects: Inclusive education -- Zimbabwe Educational equalization -- Zimbabwe Physical education and training -- Study and teaching (Secondary) -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/2116 , vital:27611
- Description: The purpose of the present study was to explore the implementation of the inclusive education policy in sport in four secondary schools in Masvingo District, Zimbabwe. The case study research design was employed; interviews, focus groups, document analysis and observations were used to collect data. Four school Heads, 4 sports masters, 4 team trainers, 4 team captains, 2 learners with disabilities and a district education officer were purposively selected to take part in this study. Data were presented, analysed/discussed, starting with demographic data in the first section followed by emerging themes. It emerged from the study that all the participants were not knowledgeable about inclusive education and the aspect of including learners with disabilities in mainstream sport. The major barriers identified include inadequate policy dialogue, unavailability of sporting equipment and attitudes. Further findings revealed that there is dire need for knowledge and skills in inclusive sport among teachers in regular schools. Findings also confirmed unavailability of policy circulars in schools. Most teachers were not afforded opportunities to attend workshops and seminars. Findings also revealed that teachers faced major challenges such as funding to undertake courses in SNE and inclusive sport. Teachers were reeled in with a lot of pressure due to congested timetables and large classes. Participants believed that the challenges they faced could be resolved through some proposed intervention strategies. The researcher concluded that teachers in regular schools were not equipped to teach sport to learners with special education needs in the mainstream. The MoPSE was not doing much in preparing teachers to be effective in including learners with disabilities in regular school sport. The study recommended that the MoPSE should put in place provisions to meet the inclusive needs of both teachers and learners. It also recommended that school Heads should be taught about SNE and inclusive sport for them to be able to guide teachers properly. Besides the national policy, schools should design inclusive policies specifically for their respective schools in line with the national policy. The study also recommended that the MoPSE should come up with a comprehensive framework in sport to counter some of these challenges.
- Full Text:
- Date Issued: 2016