Spatio-temporal analyses of woody vegetation cover using remote sensing techniques: the case of Alice - King Williams Town route, Eastern Cape, South Africa
- Authors: Fundisi, Emmanuel
- Date: 2016
- Subjects: Woody plants -- South Africa -- Eastern Cape Vegetation classification -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/1830 , vital:27564
- Description: Expansion of woody vegetation results in the transformation of a grass-dominated ecosystem to a tree-dominated ecosystem causing land degradation in most semi-arid areas. The imbalance in the natural ecosystem between herbaceous plants and woody vegetation poses a threat to the natural environment. Such changes alter the flow, availability and quality of nutrient resources in the biogeochemical cycle. Most of the dominating woody plants are often unpalatable to domestic livestock. Therefore, the objective is to assess the spatial extent of woody vegetation over time. Knowledge of the spatial and temporal characteristics of woody vegetation dynamics will enable the development of management plans. These characteristics can be derived using remote sensing techniques which have become efficient in such studies. This study aimed to characterize woody vegetation dynamics along the route between Alice and King Williams’s town in Eastern Cape Province South Africa using Landsat data. This aim was achieved by focussing on three specific objectives. The first objective was to compare the performance of multispectral data and Normalized Difference Vegetation Index (NDVI) data of Landsat imagery in mapping woody vegetation cover. The second objective was to investigate the effect of the spatial resolution of remotely-sensed data on discrimination of woody vegetation from other land cover types. The third objective characterised woody vegetation dynamics between 1986 and 2013/2014 using the results from the first objective. The study used Landsat imagery acquired in November or February of 1986, 1994/1995, 2002/2003 and 2013/2014. Due to lack of data which covered the study area two separate dates (November and February) where used for the study resulting in naming the study area western and eastern parts. Unsupervised classification was performed on the multispectral, NDVI and pan-sharpened images to generate four generic land cover classes, namely water, bare land, grassland and woodland. Accuracy assessments of the classified images was done using error matrix. The results showed that the classification based on NDVI images yielded a better overall accuracy than the classification based on multispectral images for the western (83 percent and 75 percent, respectively) and eastern (82 percent and 76 percent, respectively) parts of the study area. Similarly, pan-sharpening resulted in better overall classification accuracy than multispectral, but comparable to the classification of the NDVI images for both the western (82 percent) and eastern (83 percent) parts of the study area. Remote sensing is an effective tool in assessing changes in the physical environment. Landsat imagery is suitable in assessing land cover dynamics given the long-term and free availability of the image. In addition, the large spatial coverage it provides, enables Landsat data to be used on studies that have wide spatial coverage. Classification for the purpose of time-series analysis was then performed on the NDVI images of each date (1986, 1994/1995, 2002/2003 and 2013/2014). Both woody vegetation and grassland experienced changes from 1986 to 2013/2014 with grassland occupying (75 percent) compared to woodland (17 percent) in 1986. In the year 2013/14 grassland occupied 32 percent and woodland occupied 51 percent of the study area. The increase in woody vegetation in the study area can be attributed to livestock rearing and migration of people from the rural to urban areas post-Apartheid. The study output will aid in the development of a database on land cover distribution of the area between King William’s town and Alice town, providing useful information to decision-making and further studies on woody vegetation.
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- Date Issued: 2016
Synthesis and structural studies of NiS and PdS nanoparticles/nanocomposites from dithiocarbamates single source precursors
- Authors: Nqombolo, Azile
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11359 , http://hdl.handle.net/10353/d1021326
- Description: The main aim of this research is to synthesize Ni(II) and Pd(II) dithiocarbamate complexes and use them as single source precursors for the synthesis of NiS and PdS nanoparticles and metal sulphides potato starch nanocomposites. Four dithiocarbamate ligands were synthesized and characterized using elemental analysis and spectroscopic techniques. The ligands were used to prepared homoleptic Ni(II) and Pd(II) complexes of the dithiocarbamate ligands. The metal complexes were characterized with elemental analysis, UV-Vis, FTIR and 1H-NMR spectroscopic techniques. Conductivity measurements indicate that all the complexes are non-electrolytes in solution and results from the electronic spectra studies confirmed the proposed 4-coordinate square planar geometry around the metal ions. The nickel complexes showed d-d transitions around 477 nm while in the palladium complexes, no d-d transitions were observed but the compounds showed strong metal to ligand charge transfer transitions. From the FTIR spectra studies, it can be confirmed that the complexes were successfully synthesised because all peaks of interest were observed at expected regions from the literature. The νC-N was observed around 1469-1495 cm-1, νC=S around 1101-1188 cm-1 and νC-S around 738-1060 cm-1 for both Ni(II) and Pd(II) complexes. νNi-S was observed around 375-543 cm-1 and νPd-S around 529-545 cm-1. The FTIR also confirmed that the dithiocarbamate ligands act as bidentate chelating ligands through the sulfur atoms. The complexes were used as single source precursors and thermolysed in hexadecylamine (HDA) at 220 °C to prepare four HDA-capped nickel sulfide nanoparticles and four palladium sulfide nanoparticles. The as-prepared nanoparticles were studied with optical absorption spectra, photoluminescence, powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The optical studies results showed that NiS have large band gaps that are greater than that of the bulk, therefore they are found to be blue shifted relative to the bulk, which shows that they have small particle size and thus confirming their quantum confinement effect. PL spectra reveal that the emission peaks are red shifted compared to the absorption band edges of the nanoparticles. The XRD patterns confirmed the formation of cubic and rhombohedral phase for NiS nanoparticles and cubic phase for PdS nanoparticles. SEM images of both NiS and PdS show uniform surface morphology at low and high magnification with different shapes. EDS analyses confirmed the presence of Ni, S, and Pd in each of the spectrum indicating that the nanoparticles were successfully synthesized. TEM images showed that the synthesised nanoparticles have uniform and narrow size distribution with no agglomeration. The sizes of the NiS nanoparticles were found to be in the range of 12-38 nm for NiS1, 8-11 nm for NiS2, 9-16 nm for NiS3 and 4-9 nm for NiS4. The TEM images for the as-prepared PdS nanoparticles showed that the average crystallite sizes are 6.94-9.62 nm for PdS1, 8-11 nm for PdS2, 9-16 nm for PdS3 and 4-9 nm for PdS4 respectively. The nanoparticles were used to prepare potato starch nanocomposites and SEM images indicate that the surface morphology of starch polymer nanocomposites compose of potato starch and few particles in between the pores of the matrix, this is due to the small ratio of nanoparticles used.
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- Date Issued: 2016
Technical and institutional constraints faced by vegetable co-operatives in the Buffalo City Metropolitan Municipality in Eastern Cape Province, South Africa
- Authors: Madlodlo, Sinazo
- Date: 2016
- Subjects: Agriculture, Cooperative -- South Africa -- Eastern Cape , Vegetable trade -- South Africa -- Eastern Cape , Cooperative marketing of farm produce -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/1497 , vital:27396
- Description: This study focused on the technical and institutional constraints faced by the vegetable co-operatives with regard to the impact on productivity. Vegetable co-operatives have no access to markets due to their poor performance on productivity and poor quality produce resulting to low prices for the produce such that they cannot compete in a market economy. In this study, the data was drawn from a sample of thirty vegetable co-operatives in the Buffalo City Metropolitan Municipality (BCMM) of the Eastern Cape; obtained through focus group discussions and interviews from each cooperative. The objectives of the study are to measure the productivity of vegetable co-operatives using Total factor productivity analysis (TFP) and profitability of vegetable co-operative using Gross Margin (GM). Followed by the descriptive statistics in identifying and assessing the socio-economic characteristics as well as coping strategies adopted by vegetable co-operatives in BCMM where percentages, means and tables are used looking at the highest frequency. The results show that the vegetable co-operatives in the BCMM are not productive and profitable due to major constraints experienced by co-operatives such as lack of market, information, trainings and business skills, capital, infrastructural facilities, effective extension services that all leads to poor produce quality. Co-operative is said to be profitable and viable if total revenue is greater than the total variable cost which makes the gross margin positive. In this case, the total gross margin is negative. The results showed that the production costs, maintenance (tractor hire, generator hire and servicing) and electricity costs were the major costs incurred in the production of vegetable by the co-operatives.
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- Date Issued: 2016
The biomass production, nutrient content and silage quality of Perennial ryegrass (Lolium perenne (L)) Cocksfoot (Dactylis glomerata (L)) and Tall fescue (Festuca arundinacea (Schreb)) varieties grown under irrigation in Alice, South Africa
- Authors: Tikwayo, Sizwe Edward
- Date: 2016
- Subjects: Ryegrasses -- Varieties -- South Africa -- Eastern Cape Ryegrasses -- Irrigation -- South Africa -- Eastern Cape Biomass energy -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/1796 , vital:27560
- Description: The study aims to evaluate the biomass production and nutrient content and silage quality of perennial ryegrass (Lolium perenne (L)), cocksfoot (Dactylis glomerata (L)) and tall fescue (Festuca arundinacea (Schreb)). Six varieties were used, two for each species. A completely randomized block designed replicated three times was conducted at University of Fort Hare Research Farm during 2014-2015 growing season. The plots were harvested at four-week interval (post emergency) for one year. Biomass yields were measured for fresh forage and dry matter yield. Duplicated samples were then dried, milled and analyzed for chemical and mineral composition (CP, NDF, ADF, and ash, Ca, P, K, Na, Mn, Cu, Zn and Fe) for only winter season. In addition the grasses were ensiled and the silage was analyzed for its fermentation parameters and nutrient content (lactic acid, pH, DM, CP, NDF, ADF, and ash, Ca, P, K, Na, Mn, Cu, Zn and Fe). Biomass results showed significant differences (P < 0.05) between season and varieties. On average Tall fescue varieties Jessup (13741.67 FM kg/ha), Alix (12007.78 FM kg/ ha) and Ryegrass varieties Samson (11597.22 FM kg/ha) and Nui (10591.67 FM kg/ha) had the highest fresh biomass yield. Similarly, Tall fescue varieties Jessup (2833.06 DM kg/ha) and Alix (2708.3 DM kg/ ha) and Ryegrass varieties Samson (2169.44 DM kg/ha) and Nui (2169.67 kg/ha) had the highest dry biomass yield. Throughout the year the average biomass yield was significantly different among species (P< 0.05). During summer and autumn Tall fescue varieties Jessup and Alix gave the highest dry matter yields of 3855.5 to 1977.8 DM kg/ha, and 3877.8 to 1900 DM kg/ha, respectively, and followed by Cocksfoot 2400 DM kg/ha. Ryegrass had the highest dry matter biomass yield in winter (2975 DM kg/ha) and the least in summer (977.75 DM kg/ha). There were no significant (P>0.05) differences on the chemical composition (CP, NDF, ADF, and ash) and mineral composition (Ca, P, K, Na, Mn, Cu, Zn and Fe) of the six varieties. The grass silage results showed significant differences (P< 0.05) among the six varieties for moisture content. Perennial ryegrass variety Nui (66.76 percent) had low moisture content than the other grass silages. The different varieties had no significant effects (P>0.05) on chemical composition (CP, NDF, ADF, and ash) and mineral composition (Ca, P, K, Na, Mn, Cu, Zn and Fe). It is concluded that the biomass production of the six varieties of three grass species was different throughout the year under irrigation hence Ryegrass and Tall fescue are recommended for dairy farmers in the region for all seasons. It can be concluded that there is no difference with respect to fermentation characteristics and nutrient content among the varieties of the grass species.
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- Date Issued: 2016
The classsification of fuzzy subgroups of some finite Abelian p-groups of rank 3
- Authors: Appiah, Isaac Kwadwo
- Date: 2016
- Subjects: Fuzzy sets Abelian groups Finite groups
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2468 , vital:27845
- Description: An important trend in fuzzy group theory in recent years has been the notion of classification of fuzzy subgroups using a suitable equivalence relation. In this dissertation, we have successfully used the natural equivalence relation defined by Murali and Makamba in [81] and a natural fuzzy isomorphism to classify fuzzy subgroups of some finite abelian p-groups of rank three of the form Zpn + Zp + Zp for any fixed prime integer p and any positive integer n. This was achieved through the usage of a suitable technique of enumerating distinct fuzzy subgroups and non-isomorphic fuzzy subgroups of G. We commence by giving a brief discussion on the theory of fuzzy sets and fuzzy subgroups from the perspective of group theory through to the theory of sets, leading us to establish a linkage among these theories. We have also shown in this dissertation that the converse of theorem 3.1 proposed by Das in [24] is incorrect by giving a counter example and restate the theorem. We have then reviewed and enriched the study conducted by Ngcibi in [94] by characterising the non-isomorphic fuzzy subgroups in that study. We have also developed a formula to compute the crisp subgroups of the under-studied group and provide its proof. Furthermore, we have compared the equivalence relation under which the classification problem is based with various versions of equivalence studied in the literature. We managed to use this counting technique to obtain explicit formulae for the number of maximal chains, distinct fuzzy subgroups, non-isomorphic maximal chains and non-isomorphic fuzzy subgroups of these groups and their proofs are provided.
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- Date Issued: 2016
The perceptions of nurse educators regarding the use of high-fidelity simulation in nursing education at a South African private nursing college
- Authors: Janse van Vuuren, S V
- Date: 2016
- Subjects: Nursing -- Study and teaching -- Simulation methods Simulated patients
- Language: English
- Type: Thesis , Masters , MCur
- Identifier: http://hdl.handle.net/10353/1752 , vital:27555
- Description: Although Nurse Educators are aware of the advantages of simulation-based training, some still feel uncomfortable to use technology or lack the motivation to learn how to use the technology. The aging population of nurse educators cause frustration and anxiety. They struggle with how to include these tools, particularly in the light of faculty shortages. Nursing education programmes are increasingly adopting simulation in both undergraduate and graduate curricula. Scoping literature reviews show that nursing practice has changed in recent years, placing demands on nurse educators to utilise different approaches in education. The fact that nurse educators are an aging population needs to be taken into consideration and acknowledge that many of them did not grow up with computers and lag behind in technological skills. The aim of this study was to investigate the perceptions of nurse educators regarding the use of high-fidelity simulation in nursing education at a South African Private Nursing College in order to be able to determine why High-fidelity Simulators (HFS) have not yet been embraced by nurse educators and students. A national survey of nurse educators and clinical training specialists was completed with 128 participants; but only 79 completed the survey. In addition to background information, participants were questioned about their use of simulators. They were asked to complete the Technology Readiness Index. Information was also obtained regarding their perceptions of the use of HFS. Findings included indications that everyone is at the same level as far as technology readiness is concerned; this, however, does not play a large role in the use of HFS. This finding supports the educators’ need for training to adequately prepare them to use simulation equipment. Recommendations for further study include research to determine what other factors play a role in the use of HFS, studies to determine whether the benefits of HFS are superior to other teaching strategies warranting the time and financial commitment. The results of this study can be used as guidelines for other institutions to prepare their teaching staff for the use of HFS.
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- Date Issued: 2016
A survey of the classification of fuzzy subgroups of some finite groups
- Authors: Makamba, Babington
- Date: 2015-03-18
- Language: English
- Type: Inaugural lecture
- Identifier: vital:11981 , http://hdl.handle.net/10353/d1016591
- Description: In this lecture we survey the classification of fuzzy subgroups of finite groups as studied byProf. B.B Makamba and V. Murali. We present the impact of the research on our postgraduate students. The classification is focusing on finite abelian p-groups and dihedral groups, giving a mixture of abelian and non-abelian groups. We show some highlights and what still needs to be done in the classification of fuzzy subgroups. We also touch on what other researchers have achieved in the classification of fuzzy subgroups and how our work is related to theirs. We begin with a historical background of fuzzy logic. , Inaugural Lecture Address by Prof. Babington Makamba- A survey of the classification of fuzzy subgroups of some finite groups.
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- Date Issued: 2015-03-18
A comparative study of the in vitro antidiabetic properties, cytotoxicity and mechanism of action of Albuca bracteata and Albuca setosa bulb extracts
- Authors: Odeyemi, Samuel Wale
- Date: 2015
- Subjects: Medicinal plants Herbs -- Therapeutic use Diabetics -- Alternative treatment
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/3154 , vital:28327
- Description: The search for cheap, non toxic and readily available antidiabetic drugs has been a challenge for researchers and the pharmaceutical industries. Diabetes mellitus is a metabolic disease characterized by defects in the synthesis of insulin and/or insensitivity to the action of insulin at the target cells. The disease has been on the increase mostly in developing countries where large proportions of the population have little access to good medical care due to either accessibility or non availability of synthetic drugs. This has led to the use of medicinal plants to treat diabetes because it is safe, cheap and with few side effects. There is little scientific evidence on the dosages, active compounds, mechanisms of action and toxicity of these traditionally used plants. Two of the most frequently used plants; Albuca setosa and Albuca bracteata were investigated in this study. The qualitative analysis of different extractions of these plants revealed the presence of phenolics, alkaloids, tannins and saponins. The antioxidant properties of aqueous, acetone and methanollic extracts of Albuca setosa and Albuca bracteata were investigated using models such as Diphenyl-1-Picrylhydrazyl (DPPH), 2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), Ferric ion reducing antioxidant potential (FRAP), Nitric Oxide and Hydrogen Peroxide (H2O2). Both plants revealed inhibitions against DPPH in a concentration - dependent manner with Albuca setosa (0.330 mg/ml) showing higher activity than Albuca bracteata (0.647 mg/ml) determined from the IC50. The aqueous extract of Albuca setosa showed a higher inhibition against DPPH radical compared to the Albuca bracteata aqueous extract at all concentrations investigated. The isolated saponins from Albuca bracteata had a higher DPPH scavenging activity than the crude methanolic extract of the plant in a concentration - dependent manner but are significantly different from each other at 0.4, 0.6 and 1.0 mg/ml only. The IC50 of the saponins was also observed to be higher than the crude extracts and standards.The Albuca setosa aqueous extract showed a higher percentage inhibition of ABTS radicals than Albuca bracteata at all the concentrations investigated. Overall, the Albuca setosa aqueous extract (0.0809 mg/ml) showed maximum activity against ABTS radicals. The iron reducing power was significantly higher (P < 0.05) in the methanolic extract of both plants compared to the aqueous counterpart. Overall, the Albuca bracteata aqueous extract (0.344 mg/ml) showed maximum activity as indicated by the IC50. The aqueous extracts of both plants also revealed percentage inhibitions in a concentration - dependent manner against NO2. The aqueous extract of Albuca bracteata bulb was more active against nitric oxide and hydrogen peroxide inhibition. In this study, the cytotoxicity of the extracts was evaluated at a high dose of 100 μg/ml on Chang liver cells and determined using MTT, crystal violet, glucose consumption, lactate production and lactate dehydrogenase release and FRAP. The aqueous extracts of both Albuca setosa and Albuca bracteata were non-toxic on Chang liver cells at the concentrations investigated. The MTT revealed that the aqueous extract of Albuca setosa bulb had the optimum cell viability of 108.09 percent while the acetonic extract of Albuca bracteata showed the least cell viability (37.72 percent) compared with the control. The crystal violet test also revealed the acetone extract of Albuca bracteata to have the least percentage of cell viability at 31.47 percent, while the aqueous extract of Albuca setosa showed the maximum cell viability at 112.5 percent. The aqueous extracts of both plants showed higher percentage cell density on the second day of incubation from the proliferation assay. All the tested samples were observed to consume more glucose than the blank except for the methanollic and acetone extracts of Albuca bracteata bulb. The aqueous and methanolic extracts of Albuca setosa bulbs produced the highest lactate with 120.2 μg/ml and 113.7 μg/ml respectively. The acetone extracts of both Albuca setosa and Albuca bracteata revealed toxicity with a higher lactate dehydrogenase release compared to the control.
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- Date Issued: 2015
A preliminary study on the effects of elevated CO2 on aphid resistance of Tugela Dn and the population dynamics of the Russian wheat aphid (Homoptera: Aphididae), Diuraphis noxia
- Authors: Mundondo, Daphine
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Biochemistry)
- Identifier: vital:11402 , http://hdl.handle.net/10353/d1020244
- Description: Food security is of major importance due to the increasing world population with 8.9 billion people expected by 2050 (Cohen, 2003). Diuraphis noxia (RWA), have caused aggravating, massive losses to wheat farmers in many areas of the world. If unchecked, RWA are able to destroy plants resulting in major economic impacts (Botha, 2013). Due to ineffective use of other control methods, the Small Grains Institute in Bethlehem, South Africa, have therefore developed resistant cultivars to the known RWA subtypes over the past decades through intensive breeding programmes (Tolmay et al., 2006). Climate change has however become a major factor threatening food security especially with the observed increase in CO2 from less than 300 ppm in pre-industrial period to the current 385 ppm and is predicted to reach 550 ppm by 2050 (IPCC, 2007; Meehl et al., 2007). Elevated CO2 concentration may affect individual species of a community hence the need to understand the wheat-aphid interactions. In this study, population growth rates and virulence of RWA SA1 at ambient (385 ppm) and elevated (450 ppm) CO2 concentration were evaluated on two wheat cultivars: Tugela Dn (resistant) and Scheepers (susceptible). Fluorescence microscopy techniques using aniline blue were used to investigate feeding related damage caused by RWA SA1 through an examination of callose deposition at the two CO2 concentration. A two-dimensional gel electrophoresis method was developed in order to determine the effect of RWA SA1 on the wheat cultivars proteome at the two CO2 concentration. Differentially expressed proteins that were up or down regulated more than two fold were identified using PDQuestTM Basic 2D Gel analysis software. Populations of RWA SA1 increased significantly on the two wheat cultivars at both CO2 concentration. Although the population growth rate for RWA SA1 on both cultivars was generally exponential at all treatments, growth at elevated CO2 concentration was noticeably faster with populations increasing 3 fold in 14 days as compared to the 2 times at ambient CO2 concentration. Hence, both cultivars provided a better quality host for RWA SA1 at 450 ppm than 385 ppm. There was no significant difference between RWA SA1 population on Tugela Dn and on Scheepers at elevated CO2 concentration on day 14 after infestation which means there was a change in the resistance mechanism in Tugela Dn at this condition. Approximately 70% of the total leaf showed chlorosis by 21 days of aphid infestation for both cultivars although the susceptible cultivar was more vulnerable. There was low callose deposition in the controls (uninfested plants) but heavy callose in infested plants due to aphid feeding. A proteomics approach was used as a pilot study to investigate whether it would be possible to identify the changes in the resistance mechanism during aphid infestation under elevated CO2 levels. The major changes in the proteome of the control group (uninfested Tugela Dn at ambient versus elevated CO2 concentration) occurred in the early events (day 1-7) in the molecular weight range of approximately 25 kDa to 55 kDa are mainly within the basic to neutral pH range. This was suggested to be a result of mechanisms to adjust to the CO2 concentration. Elevated CO2 results in instant higher photosynthetic rates and C:N ratios as well as changes in expression levels of SA-dependant defense genes (Lindroth 1995; Hughes and Bazzaz, 2001; Sun et al., 2013). Because most of these changes are directly regulated by proteins, it is expected that the most differential protein expression will occur immediately after the atmospheric changes (early events) as was shown in the study. Infested plants under elevated and ambient conditions showed that the stress conditions gave rise to differentially regulated proteins within the wheat proteome. Most changes occurred elevated CO2 levels. It can be suggested that the changes were a result of differentially regulated plant defence proteins which fall in this range (25 kDa - 80 kDa) such as peroxidases, chitinases and β-1.3-glucanases as well as protein kinases, heat-shock proteins and photosynthetic proteins. These results indicate that there has been changes in the resistance due to elevated CO2 because of the evident changes in the proteome. If so, then the results will be similar to those documented by Louw (2007) where up-regulation was due to putative storage proteins, proteins involved in photosynthesis, heat shock proteins and defense proteins. Of course, the pI value and molecular mass of the proteins and the identification of the proteins in these spots, must be determined in future work to specifically identify whether these suggestions are authentic. However, Louw (2007) also reports that the susceptible Betta wheat cultivar, displayed a defence response similar to the HR although it was unable to up-regulate specific defensive proteins against RWA infestation but proteins for broad resistance. Although the changes in the proteins in infested Tugela Dn under elevated CO2 concentration were not accurately identified, the defense mechanism is similar to that portrayed by the susceptible Betta wheat cultivar which shows that the resistance mechanism had been overcome. Because this was a pilot study and preliminary results were obtained due to limited funding and time constraints, suggestions were made on how to further develop the method to obtain statistically significant results.
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- Date Issued: 2015
An evaluation of security issues in cloud-based file sharing technologies
- Authors: Fana, Akhona
- Date: 2015
- Subjects: Cloud computing -- Security measures Computer networks -- Security measures Computer security
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/1841 , vital:27565
- Description: Cloud computing is one of the most promising technologies for backup and data storage that provides flexible access to data. Cloud computing plays a vital role in remote backup. It is so unfortunate that this computing technique has flaws that thrilled and edgy end users in implementing it effectively. These flaws include factors like lack of integrity, confidentiality and privacy to information. A secure cloud is impossible unless the computer-generated environment is appropriately secured. In any form of technology it is always advisable that security challenges must be prior identified and fixed before the implementation of that particular technology. Primarily, this study will focus on finding security issues in cloud computing with the objective of finding concerns like credential theft and session management in the ―Cloud‖. Main arguments like HTTP banner disclosure, Bash ―ShellShock‖ Injection and password issues were discovered during the stages of study implementation. These challenges may provide information that will permit hackers in manipulating and exploiting cloud environment. Identifying credential theft and session management in cloud-based file sharing technologies a mixed method approach was implemented throughout the course of the study due to the nature of study and unity of analysis. Penetration tests were performed as security testing technique. Prevention and guideline of security threats leads to a friendly and authentic world of technology.
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- Date Issued: 2015
An investigation of skills and knowledge of women participating in water and food security projects in the Eastern Cape Province: a case of Mbekweni village, Sirhosheni and Lutengele villages
- Authors: Makeleni, Maliviwe
- Date: 2015
- Subjects: Agricultural development projects -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11235 , http://hdl.handle.net/10353/d1021306 , Agricultural development projects -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape
- Description: The South African government initiated programmes to ensure that women in agriculture are empowered with sufficient agricultural skills and knowledge to engage in agriculture in order to alleviate poverty for their families and communities. Studies argue that within the agricultural sector, women are not capacitated adequately enough in terms of the skills and knowledge they need to acquire, and particularly as this relates to their ability to have knowledge about more advanced technologies in farming. This includes the most up to date knowledge related to sustainable-development. This study has attempted to investigate skills and knowledge possessed by women participating in water and food security projects in the Eastern Cape. Selected study areas were Mbekweni village located in Whittlesea, Sirhosheni village which is situated in Willowvale and Lutengele village in Port St Johns. The thesis was also aiming to find the skills/knowledge gap amongst the sample so as to come up with recommendations. The data was collected using two semi-structured questionnaires. The first questionnaire was for the main survey which mainly concentrated on the socio-economic information of the respondents. This data were collected from 163 households across three sites using systematic sampling. The second questionnaire was mainly used to gain more in-depth analysis. The data were collected from 30 households across three sites using purposive sampling. Both questionnaires were administered through face-to-face interviews. The majority of respondents have stated that they have basic knowledge and skills in farming, however they need further training on appropriate planting methods for various crops, irrigation scheduling and frequency, application of pesticides and marketing skills. Econometric analysis, through the use of the binomial regression model revealed that education affects the level of knowledge of farmers in selecting appropriate planting methods as well as farmers’ knowledge in determining seed depth of a crop. Gender influences the level of knowledge farmers have when selecting appropriate planting methods. Having extension assistance was recognised to affect farmers’ knowledge in determining irrigation scheduling and intensity. All variables were statistically significant showing a 5% level. The thesis ultimately argues that encouraging support to agricultural extension that respects local-level indigenous farming will increase the food-security potential of residents within the Eastern Cape.
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- Date Issued: 2015
Assessment of bioflocculant production by two marine bacteria isolated from the bottom sediment of marine Algoa Bay
- Authors: Ntozonke, Ncedo
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11298 , http://hdl.handle.net/10353/d1021290
- Description: Bioflocculants are polymers, mostly, of microbial origin which floc out suspended particles from liquid medium. The ability of these biopolymers to remove suspended particles from solutions is termed bioflocculation, and the efficiency of flocculation activities depends on the characteristics of the flocculants. In comparison with conventionally used flocculants, bioflocculants have the advantage of being safe (no toxic effects known), biodegradable and harmlessness to the environment. The study assessed production of bioflocculant by two marine bacteria from the bottom sediment of marine environment. The 16S rDNA was used for identification, and the two bacteria species were identified as Enterococcus hirae and Bacillus thuringiensis. Factors affecting the production and activity of the bioflocculants produced by these two organisms were studied. The bacteria optimally produced bioflocculant with fructose (91.7%) and urea (91%) as sole carbon and nitrogen sources respectively. Mg2+ (87%) and Ca2+ (86%), likewise, served as best cation sources on the production of the bioflocculant at pH 5(93%). Additionally, the flocculating activity of the bioflocculant increased with the addition of Mg2+ (81%) and Na+ (81%), and the highest flocculating activity was at pH 5 of the kaolin clay. The Fourier transform infrared spectroscopy (FTIR) shows that the bioflocculant is a glycoprotein. The second bacterium (Bacillus thuringiensis) produced bioflocculant optimally when the media had mixed nitrogen sources (Urea, ammonium chloride and tryptone (67%)) and glucose (85.65%) as a sole carbon source, also Ca2+ (74.6%) was the best cation that induced the production of bioflocculant. After purification, the bioflocculant flocculated optimally in alkaline pH 12 (81%) in the presence of Mn2+ (73%) and Ca2+ (72.8%). Chemical analysis of the bioflocculant revealed it to be a polysaccharide. Both bioflocculants flocculate efficiently and can be used to replace synthetic flocculants in water treatment, wastewater, in downstream processing, and processing of food and chemicals and other industrial uses of flocculants. Challenges though (i) are to develop conditions for large scale production of the bioflocculant, (ii) to do further characterization of the both bioflocculants (iii) to assess the bioflocculants for treatments of water/wastewater, and to apply it in various industrial processes.
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- Date Issued: 2015
Assessment of the effects of stream channel incision on soil water levels, soil morphology and vegetation in a wetland in the Hogsback area, Eastern Cape, South Africa
- Authors: Omar, Mohamed Yussuf
- Date: 2015
- Subjects: Hydrology Wetland Soil Formation
- Language: English
- Type: Thesis , Masters , Degree
- Identifier: http://hdl.handle.net/10353/3132 , vital:28264
- Description: Wetland degradation in the form of channel incisioning can significantly alter the hydrological functioning of a wetland. In this study in a small headwater wetland in the Hogsback area, Eastern Cape Province, the impact of channel incisioning on soil water levels and soil morphology was examined. A good correlation (R2 = 0.89) exists between the depth of channel incisioning and average water table depths in most of the 21 installed piezometers. In localised cases the upslope supply of water was in equilibrium with drainage from the piezometers. Although all the studied soils show hydromorphic characteristics, those continuously saturated close to the surface exhibit redox accumulations in oxygen supplying macropores, whereas gleyic colour patterns occur deeper in soils where the water table has been lowered by channel incision. The nature and occurrence of different hydromorphic soil indicators observed confirm the contribution of soil morphology as a valuable indicator of long-term average soil water conditions. The study evaluates the effects of hydrological processes on plant species composition and distribution in a Hogsback wetland. Twenty-four circular plots with a radius of 2 m were established between March and August 2013. Within each sample plot, the habitat information and species present were recorded including Braun-Blanquet cover-abundance value for each and every species present in the plot. Plant species were identified in the field and the unknown plant species were collected, pressed, oven-dried and identified at the National Herbarium, South African Biodiversity Institute (SANBI), Pretoria and Schonland Herbarium, Rhodes University, Grahamstown. A total of 39 taxa belonging to 19 families and 34 genera were recorded from the Hogsback wetland. Of the documented taxa, three were exotic and three endemic to South Africa, indicating diversity and dynamic nature of Hogsback wetland flora. Plant families with the highest number of species were: Poaceae (11 species), Asteraceae (5 species), Onagraceae and Cyperaceae with 3 taxa each. The low number of exotic plant species in Hogsback wetland (three taxa in total) indicates limited anthropogenic influence. Unique species recorded in Hogsback wetlands are three species that are endemic to South Africa, namely, Alchemilla capensis, Helichrysum rosum and Lysimachia nutans. Five main floristic associations were identified from the Hierarchical Cluster Analysis whilst Detrenched .Correspondence Analysis (DCA) identified four groups. The Canonical Correspondence Analysis (CCA) indicates that edaphic factors, particularly in an area covered with water, erosion category, organic matter content and water table depth were the most important environmental variables measured accounting for the vegetation pattern present in the Hogsback wetland.
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- Date Issued: 2015
Assessment of the quality indices and prevalence of Escherichia coli pathotypes in selected rivers of Osun state, Southwestern Nigeria
- Authors: Titilawo, Osuolale Yinka
- Date: 2015
- Language: English
- Type: Thesis , Doctoral , PhD (Microbiology)
- Identifier: vital:11295 , http://hdl.handle.net/10353/d1021274
- Description: Surface waters are important freshwater sources used for domestic, industrial, agricultural and recreational activities, and the availability of good quality freshwater is indispensable for preventing water-borne diseases and improving quality of life especially in communities that lack pipe-borne water. Water samples were collected from ten rivers at different locations in Osun State, Southwestern Nigeria. A total of 12 physicochemical parameters, counts of total coliforms (TC) and Escherichia coli isolates were determined using standard analytical procedures. Confirmed Escherichia coli isolates (n=300) were assessed for the presence of 10 virulence genes (VGs) associated with Escherichia coli strains causing intestinal and extra-intestinal infections. The recovered Escherichia coli isolates were elucidated for their antibiogram profiling by disk diffusion method and the resistant isolates were further profiled for their genotypic antimicrobial resistance by polymerase chain reaction technique. The physicochemical qualities ranged as follows: pH (6.9 - 7.6), temperature (26 – 29 ºC), turbidity (2.28 – 9.46 NTU), electrical conductivity (229 – 581 μS/cm), nitrate (0.03 – 0.05 mg/L), nitrite (0.00 – 0.01 mg/L), sulphate (3.33 – 20.33 mg/L), chloride ions (7.83 – 27.33 mg/L), dissolved oxygen (4.23 – 5.57 mg/L), total dissolved solids (56 – 184 mg/L), total hardness (78 – 519 mg/L) and alkalinity (50.67 – 146.67 mg/L). Statistical analysis showed that pH, temperature, electrical conductivities, nitrates, nitrites, chloride, dissolved oxygen, total dissolved solid, total hardness and alkalinity were significantly different (P < 0.05), whereas turbidity and sulphate were not significantly different (P ˃ 0.05) from each parameter with respect to sampling sites. While the VG lt for enterotoxigenic E. coli had the highest prevalence of 45%, the enteropathogenic E. coli genes eae and bfp were detected in 6% and 4% of the isolates respectively. The VGs stx1 and stx2 specific for the enterohemorrhagic E. coli pathotypes were equally detected in 7% and 1% of the isolates respectively. Also, the VG eagg harboured by enteroaggregative pathotype and diffusely-adherent E. coli VG daaE were detected in 2% and 4% of the isolates respectively and enteroinvasive E. coli VG ipaH was not detected. In addition, the VGs papC for uropathogenic and ibeA for neonatal meningitis were frequently detected in 19% and 3% of isolates respectively. While all the isolates tested were susceptible to imipenem, meropenem, amikacin and gatilofloxacin, others were variously susceptible, and resistant as follows; ciprofloxacin (96%), kanamycin (95%), neomycin (92%), streptomycin (84%), chloramphenicol (73%), nalidixic acid (66%), nitrofuratoin (64%), gentamycin (63%), doxycycline (58%), cefepime (57%), tetracycline (49%) and cephalothin (42%). Conversely, all the isolates were resistant to sulphamethoxazole, and high levels of resistance were equally observed against amoxycillin (59%), ampicilin (57%) and cefuroxime (40%). Cefepime, cephalothin, cefuroxime, nalidixic acid, nitrofuratoin, chloramphenicol and tetracycline were not significantly different in their effect against the isolates from all locations (P > 0.05), whereas the resistance profile of the isolates against gentamycin, ciprofloxacin, sulphamethoxazole, ampicillin and amoxicillin were significantly different (P < 0.05). Amikacin, kanamycin, streptomycin, meropenem, imipenem and gatilofloxacin were statistically excluded from the analysis since all tested isolates showed total susceptibility to these antimicrobials. The multiple antibiotic resistance indexing ranged from 0.50 to 0.80 for all the sampling locations and exceeded the threshold value of 0.2. Prevalence and distributions of the 19 resistance determinants assessed were obtained as follows; [sulfonamides (sulI (8%), sulII (41%)], [beta-lactams; (ampC 22%; blaTEM, (21%), blaZ (18%),], [tetracyclines (tetA (24%), tetB (23%), tetC (18%), tetD (78%), tetK (15%), tetM, (10%)], [phenicols; (catI (37%), catII (28%), cmlA1 (19%)] and [aminoglycosides; (aacC2 (8%), aphA1 (80%), aphA2 (80%), aadA (79%) and strA (38%)]. The Pearson chi square exact test revealed many strong significant associations among ampC, blaTEM, blaZ and tetA genes with some determinants screened. In the same vein, a grand total of 366 resistance gene fingerprints were spotted across the sampling locations and among the resistant pathotypes, the modal prevalent gene prints were found among the ETEC strains in 148 (40%), being the predominant pathotype observed, followed by UPEC strains 80 (22%) while the lowest was the least occurring EAEC pathotype 14 (4%). While some physicochemical parameters exceeded prescribed standards for drinking water, some fell within. The total coliforms obtained in all the sampling sites were above the acceptable limits. Findings reveal the presence of diarrhoeagenic and non-diarrhoeagenic E. coli in the selected rivers and suggest a potential public health risk as the rivers are important resources for domestic, recreational and livelihood usage by their host communities. The multiple drug resistance indexing signifies isolates and pathotypes of high antimicrobial usage origin. An increase in the antimicrobial resistance signatures towards conventionally used antibiotics as observed in this study necessitates for safe water supply, adequate sanitation facilities and proper surveillance programs towards the monitoring of antimicrobial resistance determinants in water-bodies. Generally, results from this study indicate that the river waters are not suitable for consumption, domestic or recreational use and re-echo the importance of safeguarding the freshwater resources of Southwestern Nigeria.
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- Date Issued: 2015
Characterization of some virulence and antibiotic resistance genes of Staphylococcus aureus isolated from cases of Bovine Mastitis in Nkonkobe Municipality, Eastern Cape Province, RSA
- Authors: Pekana, Abongile
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11293 , http://hdl.handle.net/10353/d1021133
- Description: Staphylococcus aureus is one of the predominant causative agents of mastitis disease in dairy herds. Mastitis disease has a negative impact in the economic losses in the dairy sector across the globe. The aim of this study is to detect some of the virulence genes in the S. aureus isolated from 400 milk samples of subclinical and clinical mastitis dairy cows in Fort Hare dairy farm and Middle Drift dairy farm in Alice in the Eastern Cape province of South Africa. In addition antibiotic resistance pattern and antibiotic resistance genes were investigated. Gram-staining, oxidase test, catalase test and API Staph kit were preliminary biochemical tests used for the identification of S. aureus isolates. The MALDI-TOF-MS was also used for further identification. Polymerase chain reaction was performed of genes encoding antibiotic resistance as well as clumping (clfA), coagulase (coa) gene, toxic shock syndrome (tsst), exfoliative toxin A and B (eta and etb), and the gene segment encoding the immunoglobulin G binding region and X region of protein gene spa. A total of 20 (5%) S. aureus strains obtained from 400 milk samples from the two farms were subjected to 16 antibiotics for antibiotic susceptibility testing. In Middle Drift dairy farm 11 (5.5%) isolates were obtained from 200 samples and 9 (4.5%) isolates were obtained in Fort Hare dairy farm from 200 samples. A large percent of the isolates were resistant to penicillin G (60%), followed by trimethoprim (60%) and tetracycline (60%), trimethoprim-sulfamethaxazole (55%), telithroprim (55%) and doxycycline (45%). Most of the isolates were sensitive to several (50-85%) antibiotics. Of the twenty isolates tested 12 samples contained the penicillin antibiotic resistance gene (blaZ gene), 8 samples contained at least one aminoglycoside-modifying enzyme gene (AME gene); the (aac(6’)/aph(2’’) gene and no amplification occurred for aph(3’)-IIIa and ant(4’)-Ia) genes. In the case of the tetracycline antibiotic resistance gene (tetK and tetM), 2 samples contained tetM and a single sample contained tetK gene. No amplification was observed for the erythromycin antibiotic resistance genes (ermA, ermB, ermC, Mef and msrA). All the samples tested were negative for the expression of toxic syndrome gene (tsst), etb, and Immunoglobulin G binding region. However, amplification of the clumping factor was observed in 7 (35%) isolates of S. aureus, exfoliative toxin (eta) expressed 4(20%) isolates; coagulase gene (coa) yielded six DNA bands of six differences sizes from 16 (80%) isolates. A total of four different bands size were expressed for the spa X region from 12 (60%) isolates. The data obtained in this study suggests that poor hygienic practices and inadequate management practices are responsible for the increase in Staphylococcus aureus isolation. The high resistance of S. aureus to antibiotics and the distribution of virulence genes contribute in bovine mastitis in these farms may cause health problems in the community consuming raw milk purchased from these farms.
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- Date Issued: 2015
Chemical constituents and biological studies of Tagetes minuta L. and Rauvolfia caffra Sond
- Authors: Mlala, Sithenkosi
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Organic Chemistry)
- Identifier: vital:11358 , http://hdl.handle.net/10353/d1021325
- Description: Consequently, specific parts or the whole plant can be used for various treatments. The aim of this study was to extract, isolate and characterize the biologically active volatile and non-volatile compounds from Tagetes minuta and Rauvolfia caffra respectively. Tagetes minuta plant was considered for extraction of essential oils using hydrodistillation method. Cis-β-ocimene (38.03%), caryophyllene oxide (18.04%), alloocimene (25.35 %), isopropyl tetradecanoate (17.02 %), cis-ocimene (38.14%) and trans-β-ocimene (37.03%) were the major components of essential oil analyzed from fresh stem, dried stem, fresh leaf, dried leaf, fresh flower and dried flower respectively. The volatile compounds were identified by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography (GC). Essential oil of dried stem leaf and flower parts of T. minuta exhibit antioxidant activity as demonstrated by the DPPH and FRAP bioassays. Crude extracts were extracted from R. caffra stem bark using sequence of solvents namely n-hexane, dichloromethane, ethyl acetate, methanol and ethanol. A white powder, a β-sitosterol (non-volatile compound) was isolated by column chromatography from ethyl acetate fractions of R. caffra stem bark and identified on various spectroscopic techniques such as FTIR and (1D and 2D) NMR. Melting point was also determined to be a sharp 129-130 ºC. DCM, EA, MetOH and EtOH fractions as well as β-Sitosterol (compound SM/01), showed antioxidant activity when tested on DPPH, FRAP, total phenolic and flavonoid bioassays. This antioxidant activity might be due to the presence of hydroxyl groups in the compound and crude fractions. On the other hand, T. minuta’s essential oil showed high antioxidant activity when evaluated on the DPPH and FRAP bioassays, which can be attributed to the presence of oxygenated monoterpenes and sesquiterpenes known to act as free radical scavenging and reducing agents. The use of R. caffra stem bark extracts against hypertension and other diseases by traditional healers could be attributed to the presence of phytochemicals (polyphenols and flavonoids) with known health benefits. Thus, it is recommended that the plant should be exploited further using modern techniques involving separation and purification of compounds that can be used for drug formulation. This study supports the use of T. minuta and R. caffra as the potential natural antioxidant source to manage various diseases including hypertension.
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- Date Issued: 2015
Consumer perceptions and values on beef quality: implications on beef markets
- Authors: Mabhera, Sunungukai.
- Date: 2015
- Subjects: Beef -- Quality -- Health aspects -- South Africa -- Eastern Cape , Livestock -- Handling -- South Africa -- Eastern Cape , Beef cattle -- Breeding -- South Africa -- Eastern Cape , Beef -- Quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11224 , http://hdl.handle.net/10353/d1020173 , Beef -- Quality -- Health aspects -- South Africa -- Eastern Cape , Livestock -- Handling -- South Africa -- Eastern Cape , Beef cattle -- Breeding -- South Africa -- Eastern Cape , Beef -- Quality -- South Africa -- Eastern Cape
- Description: Beef constitutes an important part of many consumers’ diets. Beef is the most consumed red meat in South Africa. Consumer perceptions can affect the whole supply or value chain of beef. Recently there has been increased interest in food safety; greater concern for environmental and animal welfare issues, increased importance of eating quality and healthy food as well as the greater role of food services. The demand for beef is no longer limited to economic factors alone but to non-economic factors as well. Consumers of beef in Alice have become more concerned about meat-borne risks and personal health. This research prioritized the exploration of the beef consumers’ (i) self-perception (ii) price perception (iii) benefit perception [in the form of – (a) value perception and (b) quality perception]. The study was conducted in the Eastern Cape Province specifically in Alice town and the surrounding rural areas (Ntselamanzi, Gaga, Hillcrest, Gqumashe, and Dyamala) of the Nkonkobe municipality. Anyone who admitted to eating beef and at the point of data collection bought beef for their own consumption or family consumption was deemed as a unit of analysis. Non – probabilistic sampling techniques which included accidental and random sampling were used to collect data from 100 interviewees. A semi structured questionnaire was used to analyse the perceptions and attitudes of beef consumers. The respondents were asked to indicate their agreement or disagreement with 47 statements or items presented on either five alternatives in a Likert scale scored from 1 (strongly disagree) to 5 (strongly agree) or a six Likert scale ranging from 1 (very low) through 5 (very high) to 6 (I do not know).The data was analysed using SPSS. It was discovered that beef consumers did not consider either intrinsic or extrinsic cues in isolation when purchasing beef but rather all characteristics contribute to the final perception. The Alice consumer market is heterogeneous and consists of different races with different cultures and market segments with varying needs and preferences. The results showed that five factors were extracted from forty seven items Factor 1: Information reliance and quality indication; Factor 2: convenience; Factor 3: Traceability and animal Welfare; Factor 4: Health and safety Conscious and Factor 5: Price and Branding. Furthermore, four main consumer segments emerged as - Segment 1: Informed buyers; Segment 2: Elite buyers; Segment 3: Health & safety conscious buyers and Segment 4: Apathetic buyers. The cluster analysis shows that quality is a subjective concept that is informed by a consumer’s personal taste and preferences. Taste and preferences inform the consumer’s effective demand which in retrospect is informed by the consumer’s socioeconomic status.
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- Date Issued: 2015
Creating a safe learning environment in two schools in the Butterworth District, Eastern Cape
- Authors: Vokozela, Zandile
- Date: 2015
- Language: English
- Type: Thesis , Masters , Msc (Environmental Studies)
- Identifier: vital:11881 , http://hdl.handle.net/10353/d1021297
- Description: This study focuses on the creation of a safe learning environment at two schools in the Butterworth District of the Eastern Cape in South Africa. The two schools are Ndabankulu Senior Secondary School and Butterworth High School. The study is of a comparative design and aims to assist the communities of Ndabankulu Senior Secondary School, and Butterworth High School to improve health, safety and security issues of their children by reducing their exposure to environmental risks while attending school. An ethnographic study was used to collect data and the study employed questionnaires, document analysis and interviews as methods of collecting data. The primary aim of this study was to assess whether the school is still a safe place for learning and teaching to take place without fear and harm so that both learners and teachers can attain growth and development. Physical risks were assessed through observation and document analysis. Interviews were conducted with the senior members of staff while questionnaires were issued to eighty learners and were all returned back for analysis. The content analysis and interpretation yielded findings that suggests that hazards that may harm the development of learners at Ndabankulu S.S.S. and Butterworth High school exist. The study concludes that it is crucial that strategies and necessary interventions be set up and implemented to ensure that all stakeholders perceive school safety as an important aspect, both for the benefit of the school and that of the wider society. The barriers to school safety, specifically to both schools in this study need to be attended to. The study has presented findings that are consistent with those of other studies which emphasized that if barriers to school safety are identified, confronted and tackled, the schools could benefit positively from effects of involving everyone to create a safe learning environment. The conditions under which learners receive education in South Africa have to be closely and constantly monitored by Departmental officials. Teachers and managers need to be trained in their duties so that schools become places where learners are safe and enjoy reaching their future goals.
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- Date Issued: 2015
Determination and validation of medicinal plants used by farmers to control internal and external parasites in goats in the Eastern Cape Province, South Africa
- Authors: Sanhokwe, Marcia
- Date: 2015
- Subjects: Medicinal plants -- South Africa -- Eastern Cape Goats -- Parasites -- Control
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2249 , vital:27718
- Description: The broad objective of the study was to determine and validate medicinal plants used by resource-limited farmers to control internal and external parasites in goats in the Eastern Cape Province, South Africa. A survey was conducted among 50 farmers and three herbalists to determine medicinal plants used to control parasites in goats. The survey revealed nine plant species belonging to eight families that were used. Among the identified plant species, Aloe ferox, Acokanthera oppositifolia and Elephantorrhiza elephantina were the plants having the highest Fidelity Level for their use, each scored 100.00 percent, followed by Albuca setosa (83.33 percent). These plants were then selected for validation studies. Gas-Chromatography-Mass-Spectrometry (GC-MS) revealed 7, 33, 26 and 32 bioactive phytochemicals in A. ferox, E. elephantina, A. oppositifolia and A. setosa, respectively. Terpenes and fatty acids were present, oxygenated terpenes being the most abundant hydrocarbons present in all the four plant species. The effect of acetone, methanol and ethanol extracts of leaves of Aloe ferox and Acokanthera oppositifolia on tick repellency and acaricidal activity were investigated on blood engorged Ambylomma hebraeum and Rhipicephalus decoloratus ticks at concentration 15, 30 and 50 percent. The 30 and 50 percent acetone extract of A. ferox and Dazzel dip had the highest acaricidal properties of 100 percent. The 50 percent methanol extract of A. oppositifolia and 50 percent acetone extract of A. ferox had the highest repellency activity of 89 percent and 85.33 percent, respectively. Results from this study revealed that the efficacy of medicinal plants used by farmers to control ticks vary with the type of solvent used for extracting the bioactive compounds. Furthermore, it revealed that Aloe ferox and A. opppositifolia plant extracts possess repellent and acaricidal activities. In a study to investigate the anthelminthic effect of crude extracts of Elephantorrhiza elephantina and Albuca setosa plants, significant anthelminthic effect on nematodes was observed in both plants. In this study, all E. elephantina and A. setosa extracts caused paralysis and mortality. Methanol was the most effective solvent in extracting bioactive compounds and methanol extract showed the best anthelminthic effects among the crude extracts investigated in both plants. The least time taken for the worms to be paralysed was 8.33 mins and 14.33mins in 100mg/ml methanol extracts of E. elephantina and A. setosa, resepectively. Methanol extract of E. elephantina and A. setosa (100mg/ml) had the highest anthelminthic activity and mortality was recorded after 18mins and 20mins, respectively. Results from this study revealed that these two plants possess anthelminthic activities. The study revealed that resource-limited farmers use medicinal plants to control internal and external parasites in goats. Gas-Chromatography-Mass-Spectrometry analysis showed that these plants contain bioactive compounds that have a potential in controlling parasites. Validation studies showed that A. ferox and A. oppositifolia possess repellent and acaricidal activities whereas A. setosa and E. elephantina possess anthelminthic activities.
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- Date Issued: 2015
Development of high performance computing cluster for evaluation of sequence alignment algorithms
- Authors: Ngxande, Mkhuseli
- Date: 2015
- Language: English
- Type: Thesis , Masters , MSc (Computer Science)
- Identifier: vital:11399 , http://hdl.handle.net/10353/d1020163
- Description: As the biological databases are increasing rapidly, there is a challenge for both Biologists and Computer Scientists to develop algorithms and databases to manage the increasing data. There are many algorithms developed to align the sequences stored in biological databases - some take time to process the data while others are inefficient to produce reasonable results. As more data is generated, and time consuming algorithms are developed to handle them, there is a need for specialized computers to handle the computations. Researchers are typically limited by the computational power of their computers. High Performance Computing (HPC) field addresses this challenge and can be used in a cost-effective manner where there is no need for expensive equipment, instead old computers can be used together to form a powerful system. This is the premise of this research, wherein the setup of a low-cost Beowulf cluster is explored, with the subsequent evaluation of its performance for processing sequent alignment algorithms. A mixed method methodology is used in this dissertation, which consists of literature study, theoretical and practise based system. This mixed method methodology also have a proof and concept where the Beowulf cluster is designed and implemented to perform the sequence alignment algorithms and also the performance test. This dissertation firstly gives an overview of sequence alignment algorithms that are already developed and also highlights their timeline. A presentation of the design and implementation of the Beowulf Cluster is highlighted and this is followed by the experiments on the baseline performance of the cluster. A detailed timeline of the sequence alignment algorithms is given and also the comparison between ClustalW-MPI and T-Coffee (Tree-based Consistency Objective Function For alignment Evaluation) algorithm is presented as part of the findings in the research study. The efficiency of the cluster was observed to be 19.8%, this percentage is unexpected because the predicted efficiency is 83.3%, which is found in the theoretical cluster calculator. The theoretical performance of the cluster showed a high performance as compared with the experimental performance, this is attributable to the slow network, which was 100Mbps, low processor speed of 2.50 GHz, and low memory of 2 Gigabytes.
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- Date Issued: 2015