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 contribution of smallholder agriculture production to food security in rural Zimbabwe : a case study of Masvingo Province
- Authors: Toringepi, Godfrey
- Date: 2016
- Subjects: Farms, Small -- Zimbabwe Agricultural productivity -- Zimbabwe Sustainable agriculture -- Zimbabwe
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/5598 , vital:29350
- Description: Agricultural development is back on the development agenda. Even though the smallholder farmers are in the majority and at the forefront in terms of food production and agriculture being the backbone of the economy of Zimbabwe, there is no clearly defined policy on smallholder agriculture in Zimbabwe. The food insecurity has remained a continuous challenge for the rural poor in Zimbabwe. This study investigated the contribution of smallholder agriculture to food security with particular reference to the Masvingo province. The study employed qualitative method of research entailing extensive review of literature as a method of data collection. The study utilized the modernisation theory and sustainable livelihoods framework to illustrate smallholder agriculture and food security nexus. The study revealed that smallholder agriculture is the best option for addressing food security since agriculture is considered the main livelihood strategy for small scale farmers in Zimbabwe. There is general scholarly consensus that the main cause of food insecurity in Zimbabwe is a decrease in smallholder agriculture productivity. The study revealed that poor infrastructure , limited access to credit, limited access to inputs, poor investment in human development, limited access to markets and harsh climatic conditions weaken the capacity of small scale farmers to improve food security. Key recommendations are that supportive institutions need to be put in place to strengthen the smallholder farmer’s capacity to improve food security in Zimbabwe.
- Full Text:
- Date Issued: 2016
The importance of habitat use in the foraging behaviour of village chacma baboons (Papio ursinus, Cercopithecidae: Primates) in Hogsback, Eastern Cape
- Authors: Pamla, Lwandiso
- Date: 2016
- Subjects: Chacma baboon -- Behavior -- South Africa -- Eastern Cape Cercopithecidae Primates -- Behavior
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8055 , vital:31494
- Description: Baboons are among the most widespread primates in Africa because they are able to adapt their foraging behaviour and omnivorous diet under challenging and changing conditions. They are attracted by food, shelter and water on human-owned properties, which brings them into conflict with the residents in Hogsback, Eastern Cape, South Africa, and results in them being shot, trapped or poisoned. To quantify the proportion of food baboons obtain from raiding human properties and to assess the quality of this food, I recorded activity budgets for foraging and movement in two free-ranging troops (Evie’s and Nola’s troops) using direct field observation. I determined home range sizes using GIS methods. I hypothesised that a troop that frequents more human-modified areas should have smaller home ranges, higher densities and forage less than a troop that spends more time in natural habitats, irrespective of troop size, because of more readily accessible food sources. The three methods I used (100 percent minimum convex method, 95 percent fixed kernel method and quadrat method) revealed that Evie’s troop used more human-modified habitat, but had a larger home range than Nola’s troop. The troop sizes have been stable for the past four years: at last count, Evie’s troop had 47 individuals and Nola’s, 38 individuals. During my field study I also recorded diverse vocalisations made by the animals, as an aid to detecting and identifying the troops and understanding individual interactions. Responses to the presence of baboons of many of the local residents – whether affluent and living on semi-urban estates, or impoverished and hunting for food – do not augur well for the future of Hogsback’s baboons. Affluent residents with horticultural gardens occasionally shoot baboons that venture on to their properties, while rural occupants hunt baboons in their natural environment. Both of these responses cause troop disruption and decreased troop size, possibly leading to local troop extinctions.
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- Date Issued: 2016
The influence of aspirations on changing livelihood strategies in rural households of Ndabakazi villages in the Eastern Cape
- Authors: Zantsi, Siphe
- Date: 2016
- Subjects: Households -- Economic aspects -- South Africa -- Eastern Cape Rural development projects -- South Africa -- Eastern Cape Sustainable development -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/5653 , vital:29357
- Description: The objective of this study is to explore the role of aspirations on changing livelihood strategies of rural households of Ndabakazi villages in the Eastern Cape. A sample of 80 respondents was chosen randomly for the household survey and semi-structured questionnaires were used to collect the data. Focus group discussions were also used to supplement the household survey. The data was descriptively analysed using a triangulation method. The findings show that social grants, mainly pensions and non-farm employment, and child support grants are the major sources of income. The majority of the households own five hectares of land and more, in which they grow crops only in gardens adjacent to their homes. However, 29 percent do not produce any crops at all. Farming contributes a small portion to the household income. The choice of farming is more powerful than the external factors. Interest in farming is minimal and can be related to the declining farming activities; therefore, household aspirations have an influence on changing livelihood aspirations. In the case of the rural areas of Ndabakazi – as indeed in many other parts of South Africa - policies of rural development mostly take a top-down approach; as a result most of these policies do not become effective in achieving the intended outcome. Development practitioners should incorporate beneficiaries when planning so as to tailor the development initiatives with the aspirations of local people for them to be effect and achieve intended goals thus a bottom-up approach. The notion that rural household farming activities have declined because they lack inputs, farming implements other necessary support is not always true. Some households are not interested in farming and they cannot be forced.
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- Date Issued: 2016
The potential use of baobab (Adansonia digitata) seedcake as a commercial diet replacement and in feed formulation for broiler chickens
- Authors: Nxele, Sibusiso Kabelo
- Date: 2016
- Subjects: Broilers (Chickens) Adansonia digitata Chickens -- Feeding and feeds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12259 , vital:39224
- Description: This dissertation is composed of two trials that were aimed at evaluating the effects of partially supplementing Baobab seed cake in broiler diets. In the first trail, performance and cost analysis of feeding birds a commercial starter diet from day-old to 21-days of age; then feeding a blend of the commercial finisher diet diluted by a mixture of baobab seedcake and ground maize from day 22nd to 35th were evaluated. The trial was conducted in an environmentally controlled deep litter housing system using 160 Ross 308 chicks of mixed sex that were randomly allocated into 4 treatments consisting of 16 pens of 1X2m2 area per pen, within similar environmental conditions. The trial diets were formulated as follows: T1 was 100 percent standard commercial starter diet, as a control; T2 had 95 percent (112g) commercial starter diet and 5 percent BSC-maize blend (2g BSC: 4g Maize); T3 had 85 percent (102g) of the commercial starter diet and 18percent BSC-maize blend (6g BSC + 12g Maize); and T4 had 75 percent commercial starter diet and 25 percent BSC-maize blend (10g BSC + 20g Maize). All diets (T1, T2, T3 and T4) percentages were calculated based on 120g being 100 percent of the diet. Each treatment consisted of 40 birds and 4 replicates, each replicate consisting of 10 birds per pen. Feed and clean water were provided ad libitum. Feed allocation and body weights were measured at placement, then weekly. Feed intakes (FI), body weight gain (BWG) and feed conversion ratio (FCR) were calculated; then the cost analysis of feeding each diet was conducted. No significant differences (P>0.05) were found amongst all growth performance parameters. The cost efficient treatment to feed, which accumulated the cheapest cost of feed per weight gain (R33.62/kg gain) was T2 (5percent BSC+MM). The second trial was conducted to evaluate the effect of feeding diets containing graded levels of baoabab (A. digitata) seedcake on performance, apparent digestibility and digestive organ weights of broilers chickens. A total of 200 Ross 308 day-old chicks of mixed sex were randomly allocated into 4 treatment groups (T1, T2, T3 and T4). The trial diets were as follows: T1 (control), was a commercial starter diet; while T2, T3 and T4 diets contained baobab seedcake meal at 0, 5, 10, and 15percent; respectively. Inclusion of BSC in diets only affected FI during the first and third weeks. In the first week, FI had significant differences (P < 0.05) during the first and third week of the trial, respectively. Birds in T4 had the least FI, while those in T3 had the highest (P<0.05). In the third week, T3 birds had the highest FI (P<0.05), while T1 birds had the lowest. Significant differences for changes in bodyweight were only evident in the second and forth weeks of the study. During week 2, birds in T had the highest BWG, whereas T4 birds had the lowest (P<0.05); however, in week 4, there were no statistical differences (P>0.05) amongst birds in T1, T2 and T4; respectively, while T4 had the lowest BWG (P<0.05). The FCR was not statistically different among treatment groups, except in week 3, where it was highest in T4birds with T3 birds having the lowest (P<0.05). No significant differences (P>0.05) were observed among treatment groups for all parameters that were considered for digestibility and digestive organ weights. Due to the fact that two different trials were conducted, it was concluded that blend of baobab seedcake and maize from the first trial can be supplemented up to 5 percent replacement level for optimum production; while up to 10 percent baobab seedcake graded level can be used on the second trial without resulting in any negative consequences on growth performance, nutrient utilization and digestive organ weights.
- Full Text:
- Date Issued: 2016
Two uses of DNA sequence variation in tracing evolutionary processes in Old World primates (Primates: Catarrhini)
- Authors: Dosi, Banele
- Date: 2016
- Subjects: Primates -- Evolution Monkeys Cercopithecidae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8022 , vital:31464
- Description: Primate evolution is particularly interesting to humans, because it includes our own history. Molecular genetics is by far the most dynamic field in contemporary biology, and offers a host of new techniques for investigating evolutionary processes and patterns. In the mid-twentieth century molecular genetics evolved from being a means of visualising hidden variation (e.g. allozymes) to tracing phylogenetic relationships between and among species (evolutionary histories of populations), and now has a wide variety of applications in medicine, species identification and relationships, and even wildlife forensics. For my Master’s project I investigated two applications of molecular genetic analysis to questions regarding the evolution of Old World monkeys (Catarrhini). First, I participated in a study designed to test the hypothesis that different primate social structures – particularly mating systems – may be reflected in the structure of a species genome. We investigated whether increased sperm production as a result of sexual selection increases the number of copy number variations (CNVs) that can be detected by comparing the male specific region Y (MSY) located on the Y chromosome in a sample of primate species. We did not find a clear differentiation between the primate species as hypothesised, which thus requires a more complex explanation, e.g. in terms of the type of environment rather than the mating system of the species, or possibly the active/inactive status of the genes. The second part of my study was phylogeographic in approach. I collaborated with researchers studying the distribution of Afromontane samango monkeys (Cercopithecus albogularis labiatus) in the Eastern Cape. I sequenced tissues from 5 samango monkey specimens found opportunistically in the Hogsback and coastal forests and analysed their genetic variation relative to the data published by Dalton et al. 2015. The Hogsback sample was not monophyletic relative to the sample from the coastal forests, indicating that, on the basis of this very small sample size, these populations have not been separated historically. In order to validate this conclusion, I will need to investigate a larger sample size. From this study I developed valuable skills in the areas of the laboratory techniques involved in molecular sequence analysis, and an appreciation for the importance of large sample sizes in deriving reliable results. I intend to continue in the future with a phylogeographic study of samango monkeys.
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- Date Issued: 2016
Using data mining techniques for the prediction of student dropouts from university science programs
- Authors: Vambe, William Tichaona
- Date: 2016
- Subjects: Data mining Dropout behavior, Prediction of
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12314 , vital:39252
- Description: Data Mining has taken a center stage in education for addressing student dropout challenges as it has become one of the major threat affecting Higher Educational Institutes (HEIs). Being able to predict students who are likely to dropout helps the university to assist those facing challenges early. This will results in producing more graduates with the intellectual capital who will provide skills in the industries, hence addressing the major challenge of skill shortage being faced in South Africa. Studies and researches as purported in literature have been done to address this major threat of dropout challenge by using the theoretical approach which banked on Tinto’s model, followed by the traditional and statistical approach. However, the two lacked accuracy and the automation aspect which makes them difficult and time-consuming to use as they require to be tested periodically for them to be validated. Recently data mining has become a vital tool for predicting non-linear phenomenon including where there is missing data and bringing about accuracy and automation aspect. Data mining usefulness and reliability assessment in education made it possible to be used for prediction by different researchers. As such this research used data mining approach that integrates classification and prediction techniques to analyze student academic data at the University of Fort Hare to create a model for student dropout using preentry data and university academic performance of each student. Following Knowledge Discovery from Database (KDD) framework, data for the students enrolled in the Bachelor of Science programs between 2003 and 2014 was selected. It went through preprocessing and transformation as to deal with the missing data and noise data. Classification algorithms were then used for student characterization. Decision trees (J48) which are found in Weka software were used to build the model for data mining and prediction. The reason for choosing decision trees was it’s ability to deal with textual, nominal and numeric data as was the case with our input data and because they have good precision.The model was then trained using a train data set, validated and evaluated with another data set. Experimental results demonstrations that data mining is useful in predicting students who have chances to drop out. A critical analysis of correctly classifying instances, the confusion matrix and ROC area shows that the model can correctly classify and predict those who are likely to dropout. The model accuracy was 66percent which is a good percentage as supported in literature which means the results produced can be reliably used for assessment and make strategic decisions. Furthermore, the model took a matter of seconds to compute the results when supplied with 400 instances which prove that it is effective and efficient. Grounding our conclusion from these experimental results, this research proved that Data Mining is useful for bringing about automation, accuracy in prediction of student dropouts and the results can be reliably depended on for decision making by faculty managers who are the decision makers.
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- Date Issued: 2016
A study of the southwestern Karoo basin in South Africa using magnetic and gravity data
- Authors: Nxantsiya, Zusakhe
- Date: 2017
- Subjects: Groundwater -- South Africa -- Karoo
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14043 , vital:39800
- Description: The early efforts of Booth, Johnson, Rubidge, Catuneanu, de Wit, Chevallier, Stankiewicz, Weckmann and many other scientists in studying the Karoo Supergroup has led to comprehensive documentation of the geology on the main Karoo Basin with regards to understanding the age, sedimentology, sedimentary facies and depositional environments. In spite of these studies, the subsurface structure, variations in thickness of various formations in large parts of the basin, the location and orientation of subsurface dolerite intrusions, and the depth to magnetic and gravity sources remains poorly documented. A geological study with the aid of geophysical techniques, magnetic and gravity, was conducted in the southwestern part of the main Karoo Basin. The objectives of the study were to construct numerous models of the main basin that image the crust to a depth of 45 km, to determine thicknesses of various formations, to relate observed geophysical anomalies with geological bodies and lineaments, to estimate the depth of existing anomalous bodies, to determine densities and porosity of various formations, as well as to determine the mineralogy of various rocks in the Karoo Basin. In total, seventy one rock samples were collected in the main Karoo Basin for density and mineralogical studies. The density results showed that the Beaufort and Ecca Group rocks have the low mean density of 2.490 g/cm3 amongst the rocks while the dolerite intrusions have the highest mean density of 2.697 g/cm3. The porosities of various rocks determined from the measured rock densities revealed that the Ecca Group shales, particularly the Whitehill Formation has the highest porosity of 4.5percent, while the Collingham Formation has the least porosity of 1.4 percent amongst the Ecca Group shales. Mineralogical analysis of seventeen XRD samples and 26 thin sections indicate that quartz, kaolinite, and plagioclase occur as the major mineral in most sandstones and shales in the Karoo Basin, while the pyrophyllite, smectite, and talc occur as minor minerals. Other mineral constituents include, calcite, mica, and amphibole. The 2½ dimensional (2½ D) gravity modelling along seven selected profiles, across the Beattie Magnetic Anomaly (BMA), revealed that the Ecca Group sediments, a target for shale gas exploration in the Karoo, occurs within a depth range of 0 - 4000 m from the surface. The basin deepens to a depth of 4600 m in the southwestern region, near the front of the Cape Fold Belt. It was observed as well that the Karoo dolerite sills are connected at depths and are mostly concentrated at the centre, the deepest part of the basin with some having saucer shape - like structure. These observations correspond well with the borehole data from AB 1/65 and QU 1/65 presented in Linol and de Wit (2016). Thickness isochore maps that were extracted from the gravity models indicate that the Ecca Group, which is the main target for hydrocarbon exploration, thickens to the south away from the centre of the basin and reaches thicknesses of greater than 3680 m. The Beaufort Group proves to be the thickest succession in the Karoo Basin with an estimated thickness of up to 6046 m. Constructed geophysical maps with the geology overlain reveal that most magnetic anomalies are due to dolerite intrusions, while gravity lows are due to less dense shales of the Ecca Group. The depth slices of magnetic data indicate that near surface magnetic bodies occur within the depth of 42 m from the surface whereas deep seated ones occur as deep as 9488 m and possibly deeper. Gravity depth slices reveal signatures that are predominant at depth of 2403 m are of short wavelength and are mainly lineaments and circular structures. They ultimately disappear at depth of 7120 m. The depth slices further indicate that the intensity of both magnetic and gravity long wavelength signatures become stronger with increasing depths.
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- Date Issued: 2017
An evaluation and estimation of risk factors associated with cholera : case study of registered patients in Raymond Mhlaba local municipality, South Africa
- Authors: Osuji, Georgeleen O
- Date: 2017
- Subjects: Cholera -- South Africa -- Eastern Cape Risk assessment -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/15562 , vital:40459
- Description: Background: Cholera is an acute infectious disease of the small intestine caused by the bacterium called Vibrio cholerae, which has two serogroups01and 0139which is also known as choleragenic V. cholerae. This disease is characterized by profuse watery diarrhoea and severe dehydration which can lead to death of both adult and children if treatment is not promptly given. Cholera is spread through ingestion of V. cholera contaminated water and food. Cholera has displayed global presence more than seven times and caused tremendous disaster to humankind. Method: This was a retrospective study among patients with cholera within the period of ten years (2005 to 2015) and the total number of patients was 106. The target population for this study were patients at Raymond Mhlaba Local Municipality who attended Victoria hospital and were diagnosed with Vibrio cholerae species with respect to sources of water and non-water sources during the mentioned period. A multivariate Logistic regression was used to determine the risk factors of cholera and comparison was made in the treatment of cholera outcomes for factors which were statistically significant at P < 0.05. Results: The median age was 24.5 (IQR: 7.0-44.8) for all respondents with cholera. Patients within the age range of 26-40 and 41-55 were found to have a higher risk of cholera (2.20, 95percent CI: 1.51, 4.22) and (1.13, 95percent CI: 0.61, 2.01) respectively. The risk of cholera was considerably higher among the black race (2.51, 95percent CI: 1.52, 4.31) compared to the coloured (1.33, 95percent CI: 0.75, 3.713). Patients who used source of water supply from carrier/Tanker and Dam/River had higher increased risk of contracting cholera (1.71, 95percent CI: 0.92, 3.62) and (2.61, 95percent CI: 1.38, 4.25) respectively compared to patients that used other sources of water. Home, party and restaurant as places patients had eaten 24 hours earlier before the onset of cholera were associated with increased risk of severe cholera. Patients who shared toilet facilities had increased risk of cholera (0.91, 95percent CI: 0.47, 1.62) compared to the ones who used private toilet. Those patients who did not practice hand washing had an increased risk of contracting cholera (1.45, 95percent CI: 0.88, 2.12) compared to the ones who washed their hands. When Logistic regression was carried out, the following risk factors were found to be statistically significant in causing cholera at 5percent significance level; Age ( 26-40), gender, level of education, marital status, sources of water supply, place eaten in the last 24 hours before onset of cholera, type of toilet used and hand washing. Conclusion: Improvement in level of education, sources of water supply, place of last eaten before cholera sickness, toilet facilities, hand washing practices are key risk factors for cholera disease and hospitalization among patients in Raymond Mhlaba local Municipality, Eastern Cape. The strong association between water and sanitation highlights the need for a more thorough assessment of potential waterborne exposures and the risk faced by family members suffering from cholera infection cases and may warrant renewed research regarding the use of targeted chemoprophylaxis in endemic rural settings.
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- Date Issued: 2017
An investigation on the motivational feattures influence on technical efficiency and profitability of smallholder irrigated crop farmers in Kwa-Nobuhle, Eastern Cape province of South Africa
- Authors: Funde, Sibongile
- Date: 2017
- Subjects: Crops -- South Africa -- Eastern Cape -- Marketing Irrigation farming -- South Africa -- Eastern Cape Agriculture -- Economic aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/11917 , vital:39118
- Description: Substantial impact and the importance of agriculture in the economies of the developing countries is increasingly acknowledged. Agriculture generally has shown to remain crucial to economic development. It has been noted that agricultural growth plays a pivotal role in poverty reduction and employment creation. Due to the potential of the smallholder sector to alleviate poverty and minimize unemployment rate leading to the country’s economic growth, enormous development programs have in the past and continues to be implemented by South African government. Programs such as land-based development strategies including agriculture, extension services, improved technologies including irrigation establishment, revitalization and rehabilitation, water rights legislation and financial support. However, the current state of smallholder low-agricultural productivity growth trends raises concerns on what other fundamental development strategies to implement in order to enhance agricultural productivity growth. Hence, this study seeks to address the impact of social farming on agricultural productivity by investigating smallholder farmer’s motivational features. Motivational features regarded are as important determinants of success, modify behaviour, serve to mobilize and direct energy into actions. Given the importance of motivational features and their formation in social interaction, the objective of the study was to investigate motivational features of smallholder farmers with regard to expanding irrigation land, determine technical efficiency of smallholder farmers as well as their profitability generation capability. A multistage sampling method was used that involved using purposive sampling, simple random sampling was adopted where three smallholder agriculture projects using irrigation methods to farm were selected and by use of snowball sampling the study ended up collecting data from a total of 124 respondents. The sample was chosen on the basis that smallholder farmers hold attributes that were crucial for execution of this research. The study proceeded by conducting face-to face interviews of smallholder farmers, focus groups and key informant using interview schedules and a questionnaire consisting both open and close-ended questions. Data were analysed using different methods. Firstly, data were analysed descriptively to get a deeper understanding of smallholder farmer’s socio-economic characteristics as well as their motivational features. Secondly, data were analysed statistically to determine Technical Efficiency (TE) of smallholder farmers using both Data Envelopment Analysis (DEA) and Stochastic Frontier Analysis (SFA). Lastly, Gross Margin Analysis was used to measure farmer’s profitability. Results show that smallholder farmers have a range of motivational features that incorporates both productive and non-productive goals. The study made use of twenty-five goals obtained from literature studies and categorised them into six motivational feature types namely; outcome based, process focused/extrinsic, performance, achievement, intrinsic/self-efficacy, and household livelihood strategies. Smallholder female and male outcome based motivations were found to be statistically significant at 5percent, while process focused/extrinsic, performance, achievement, intrinsic/self-efficacy and household livelihood strategies motivations between them were found not to be statistically significant, which means that smallholder female and male motivations are not different and that both farmers consider such motivations at the same level. Technical Efficiency (TE) was measured using DEA method and was found to be 0.70, which is different from the TE obtained using SFA that was 0.47. Three dominant crops were produced, namely potatoes, cabbage and spinach. Cabbage crop was the most produced, had the highest gross margin results with a commercialization ratio of 0.33percent as compared to potatoes and spinach. Which indicates that cabbage is a high value crop to smallholder farmers of Kwa-Nobuhle area. In view of the research findings, it was concluded that motivational features of smallholder farmers were positively related to technical efficiency which implies that the more motivated farmers become, the higher their technical efficiency, hence their potential to expand land under irrigation. Cabbage production was high and more profitable than potatoes and spinach production. Recommendations include that government, NGO’s, private sector and institution need to promote the use of improved technologies, agricultural training and take smallholder farmer’s motivational features into account in development programmes. These actions are necessary to increase irrigated farming, overcome low-performance levels and enhance profitability of smallholder farmers, and ultimately achieve poverty alleviation and improve employment opportunities in the rural areas.
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- Date Issued: 2017
Analyses of the simple harmonic oscillator and its variations
- Authors: Bambiso, Noludwe Patience
- Date: 2017
- Subjects: Harmonic analysis Vibration -- Mathematical models Oscillations
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8132 , vital:31530
- Description: Vibratory motion is fundamental to all natural phenomena. It occurs everywhere in nature, from fundamental particles to the complexity of the life of the smallest cell, to the properties of the cosmos. Its frequency ranges from those of gammarays down the spectrum of X-rays, microwave, optical and radio waves. These are common concepts in everyday life, but their origin and nature are seldom comprehended. In this thesis we look at the mathematical fundamentals and how to apply them. We start with fundamental concepts and extend them to more complicated systems. We consider methods of analysis and applications. In Chapter 2 we consider simple harmonic oscillators and their mathematical analyses and in Chapter 3 we look at applications. Chapter 4 discusses the general form of simple harmonic motion, i.e. damped and forced harmonic motion. We consider simple coupled systems and their analysis. In Chapter 5 we introduce the method of complex functions and its application to complicated compound systems. Chapter 6 introduces a novel application, that of how SHM can be used as a model for advanced effects, or acausality. Chapter 7 presents a summary and conclusion.
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- Date Issued: 2017
Aspects of the feeding biology of the copepod Pseudodiaptomus hessei (Copepoda: Calanoida) under culture conditions
- Authors: Mzozo, Ziyanda
- Date: 2017
- Subjects: Copepoda Microbial ecology Fishes -- Feeding and feeds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4727 , vital:28502
- Description: This study aimed to investigate the feeding behaviour of the calanoid copepod, Pseudodiaptomus hessei, particularly whether it prefers to feed on a planktonic or benthic food source. The effect of different microalgae species on the feeding preference, ingestion, and gut evacuation rate were investigated. Two microalgae species (Isochrysis galbana and Tetraselmis suecica) were used, to test gut fullness and gut evacuation of P. hessei. The copepods were starved for 6 h and allowed to feed on monalgae diets, I .galbana and T. suecica, and a 1:1 binary diet mixture of T. suecica and I. galbana. The gut fullness and gut evacuation rates were determined by observing under the dissecting microscope and gut content percentage was recorded (as 0, 25, 50, 75 or 100 percent) along with copepod sex. Copepods that feed on T. suecica fill their gut after 30 min, while those that feed on I. galbana do so after 40 min. There was a significant difference (p= 0.02) between sexes with males filling their gut faster than females. However, copepods that fed on I. galbana evacuated their gut content completely after 30 min, while those fed on T suecica evacuated theirs after 40 min. There was no difference between males and females for gut evacuation. Even though there was high gut fullness rate when P. hessei was feeding on T. suecica, I. galbana is recommended as the best mono-algae diet to culture P. hessei. The feeding behaviour of P. hessei was investigated, as to whether it prefers to feed on a planktonic or benthic food source. Copepods were starved for 3 h and then allowed to feed on two microalgae species (I. galbana and T. suecica), one presented as a benthic and other as planktonic. Controls included swapping the modes of presentation for each algae species. Ingested microalgae species were quantified using real-time PCR, with threshold cycles interpreted as relative abundance ratio (planktonic microalgae divided by benthic microalgae species). Pseudodiaptomus hessei preferred to feed on planktonic food sources initially as there was a difference between planktonic and benthic ingested food (p=0.026). Copepods shifted from planktonic to benthic food sources after 80 min of feeding planktonically. Planktonic food sources were the preferred choice for P. hessei regardless of microalgae species offered. The results from this study also confirm that P. hessei feed on a benthic food source during the day under culture conditions. This information can be used as baseline information for aquaculturists to rear the species as live feed for marine fish larvae.
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- Date Issued: 2017
Assessment of the Department of Rural Development and Agrarian Reform's maize cropping programme in the Eastern Cape
- Authors: Mqamelo, Luvolwethu
- Date: 2017
- Subjects: Cropping systems Crops and climate Crop yields
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/9165 , vital:34288
- Description: The Department of Rural Development and Agrarian Reform maize cropping programme is one of the flagship projects that has been entrusted by the provincial government to tackle the social ills faced by the rural communities of the Eastern Cape Province. The programme is in line with a number of policies that strive to unlock the agricultural potential in inducing the much talked about radical economic transformation. This study was aimed at establishing if the outlay of the implementation processes and the outcomes of the maize cropping programme in Eastern Cape are sufficient to achieve the stated objectives. The study adopted a triangulation method to get comprehensive understanding of the programme and for accuracy and verification of the data collected. A pre-tested semistructured questionnaire was used to collect the demographics and socio-economic status of the respondents; technical skills and capabilities; implementation processes of the programme and the perceptions of the participants and key strategic role players in the maize cropping programme. A total of 120 respondents from DRDAR’s 2016/2017 financial year supported list and 9 key informants were sampled for the study. Furthermore, a gross margin analysis was used to establish the viability and the sustainability of the programme with and without DRDAR’s subsidies. For purposes of determining if there was any relation between the maize enterprise income and 13 independent variables, a multiple regression model was employed. The results of the study show that the programme is dominated by old and uneducated individuals with an average age of 60 years. The implementation processes are proving to be fairly progressed however, at a very limited scale. This includes provision of production inputs and mechanization services on time, formation of self-serving legal entities and unlocking the private sector investment. The gross margins generated from the programme have been observed to be non-viable and unsustainable. As a result, only 31% of the respondents were able to attain a gross margin equal or greater than the allocable costs of producing maize both under irrigation and dry land. The results of the regression model indicated that, only 5 of the 13 independent variables (household gender, marital status, years of participation, area planted and yield) were found to have a significant effect to the maize enterprise income. Overall, the DRDAR’s maize cropping programme has failed to meet its intended objectives. In addition, more than 70 percent of the programme participants produced for subsistence purposes and showed no desire to fully commercialise their operations.
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- Date Issued: 2017
Biomass yield, nutrient content and silage quality of three forage sorghum (Sorghum Bicolour (L.) varieties grown in the semi-arid region of Eastern Cape Province, South Africa
- Authors: Gwantshu, Vuyolwethu Hamilton
- Date: 2017
- Subjects: Sorghum -- Varieties -- South Africa -- Eastern Cape Sorghum -- South Africa -- Eastern Cape Forage
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/9545 , vital:34368
- Description: The study determined the biomass yield, nutrient content and silage quality of forage sorghum varieties. Three varieties were used (King, PAN 868, and PAN 888), in a randomized complete block design (RCBD) with three blocks and three replicates per treatment at the University of Fort Hare research farm. The research study was conducted during the 2016/2017 growing season. The forages were harvested at flowering stage of growth. Biomass yields of fresh forage and dry matter yield were measured. Sub-samples were then dried, milled and analysed for nutrient content. Furthermore, the forage sorghum was ensiled and the silage was analysed for fermentation parameters and nutrient content. The fresh and dry matter biomass yield showed no significant differences (P>0.05) among the varieties. The highest fresh biomass yields were observed in PAN 888 variety was 13400 kg/ha, King had 12600 kg/ha and PAN 868 had 12600 kg/ha. The dry matter yield observed in PAN 888 was 4300.00 DM kg/ha, PAN 868 had 3633.33 DM kg/ha and King yielded 3533.33 DM kg/ha. The different sorghum varieties showed a significant (P<0.01) difference in some chemical composition parameters namely DM, NDIN and NSC. The different sorghum varieties had significant difference (P<0.01) in the silage fermentation parameters of pH, starch and lactic acid. The sorghum silage varieties were significantly (P<0.01) different in the starch fermentation with values of 0.001percent. The sorghum silage varieties were significant different for fermentation of lactic acid with values ranging from 1.99 to 2.62percent. However, PAN 868 and PAN 888 were not different from each other. Similarly, all varieties were different (P<0.05) in the pH with values ranging from 4.16 to 4.53. There were no significant (P>0.05) differences in CP, Fat, NDF, ADF, Hemicellulose, Ash, and ADIN content of the silages. The mineral composition (macro and micro) of the silage were not significantly (P>0.05) different among the varieties. In conclusion, the dry matter production and nutrient content of the three forage sorghum varieties were not significantly different. The silage fermentation quality showed significant (P<0.05) differences among the three sorghum varieties. Therefore, according to the results of this study PAN 888 is the recommended variety to grow in the semi-arid region of the Eastern Cape.
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- Date Issued: 2017
Characterisation of antibacterial compounds produced by Pseudomonas spp. isolated from Hogsback wetlands, Eastern Cape, South Africa
- Authors: Obi, Akudo Odochi
- Date: 2017
- Subjects: Bacteriology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/15688 , vital:40507
- Description: With microbial pathogens developing resistance against currently existing antimicrobials, there is an earnest need to discover and develop new therapeutic compounds with unique and/or precise modes of action. Natural products have provided the inspiration for most of the active ingredients in medicines and thus are regarded as a potential screening resource lead for discovery of new drugs. Pseudomonads are ubiquitous, Gram-negative, motile bacteria that flourish and inhabit a diversity of environments. Literature has vastly revealed that some members of the genus Pseudomonas are capable of producing a plethora of biologically active metabolites and thus are regarded as “attractive” bacteria for testing as potential sources for new therapeutic compounds. In this regard, this study was undertaken with an aim to isolate and characterize antibacterial compounds produced by Pseudomonas species isolated from aquatic milieu of the Hogsback wetlands, Eastern Cape, South Africa. A total of 12 water samples were aseptically collected from Hogsback wetlands. To ascertain antimicrobial potential of the isolates, 9 test bacterial (sensitive) strains, namely Escherichia coli ATCC 3695, Vibrio fluvialis, Salmonella typhimurium, Salmonella enteritidis, Pseudomonas aeruginosa ATCC 27853, Escherichia coli (2), Listeria ivanovii, Listeria monocytogenes and Enterococcus faecalis ATCC 19433 were used for antimicrobial screening. A total of 500 presumptive Pseudomonas spp. were isolated and screened for the production of antibacterial compound through the Agar-well diffusion method. About 8percent of the presumptive Pseudomonas spp. produced compound with activity against the test bacteria and based on the levels of activity shown, three isolates coded as A53, Y55 and Y138 were selected and identified by 16S rDNA sequence analysis and The Basic Local Alignment Search Tool analysis revealed that the three isolates (A53, Y55 and Y138) belonged to the Pseudomonas genus. Using MEGA6 software, a molecular phylogenetic tree was constructed by Maximum Likelihood Method. The phylogenetic analysis by this method showed that all three isolate codes (A53, Y55 and Y138) formed the same clade with Pseudomonas viridiflava strain P3 (Accession number: AY972186) and Pseudomonas plecoglossicida strain P9 (Accession number: AY972231) at a high bootstrap value of 100percent. Isolate code A53 and Y55 also grouped together at a bootstrap value of 96percent. Factors affecting antibacterial compound production by the three isolates were elucidated. The effect of pH on the three isolates revealed that isolate code A53 and Y55 could produce antibacterial compounds over all pH ranges (pH 4-9), however, antibacterial production was produced optimally at acidic conditions (pH 4) and a less acidic-neutral condition (pH 6) respectively. Isolate Y138 showed optimal production at pH 5. The effect of temperature on all three isolates was studied at different temperatures ranging between 25°C-40°C. Study on effect of temperature variations on antibacterial production revealed that all three isolates are capable of growing and producing antibacterial compounds over all the different temperature ranges, however, maximum/optimum production was observed at temperature of 30°C. In order to establish the role of plasmids in antibacterial production, two curing agents; Sodium dodecyl sulfate (SDS) and Ethidium bromide under different sub-lethal concentrations (1 mg/ml -11mg/ml and 2.5 μg/ml- 125 μg/ml respectively) were used to cure the selected isolates. Plasmid DNA samples of A53, Y55 and Y138, were separated by electrophoresis on a 0.7percent (w/v) agarose. Agarose gel electrophoresis revealed that not all the concentrations used were effective in curing the plasmid. A Quick Load 1 kb Extend DNA ladder marker was used for determining the size of the plasmids. Isolate code A53 and Y138 had a plasmid size of 48.5 kb while isolate Y55 had a plasmid size of approximately 20 kb. Antibacterial activity by agar-well diffusion method after the curing process revealed that antibacterial production was not lost or prevented, but rather increased. Thus, it is suggested that the genes responsible for antibiotic production in this study were chromosomal-encoded and not plasmid-encoded. This study revealed that Hogsback wetlands may represent a previously unexplored environment/source of discovering novel and potent antibacterial compounds.
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- Date Issued: 2017
Characterization of livestock manures biochar and their effect on soil chemical properties and crop growth under glasshouse conditions
- Authors: Dzvene, Admire Rukudzo
- Date: 2017
- Subjects: Biochar Soil fertility
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/9863 , vital:35091
- Description: Biochar is being promoted as an amendment to improve soil properties, crop productivity, and carbon sequestration. In Africa, biochar adoption is hindered by production systems which include technology and feedstocks availability. However, little research has been published on the influence of biochar incorporation on soil chemical properties and early crop establishment. The aim of this study was to characterize biochar from cattle, goat, sheep and poultry kraal manures and their effect on soil properties and crop growth. This was guided by the following specific objectives, (i) to explore the mixed-farming system of Raymond Mhlaba Municipality on availability and utilization of livestock kraal manures (ii) to characterize biochar samples produced from cattle, goat, sheep and poultry kraal manures (iii) to determine the nutrient release patterns of biochars amended in a degraded soil (iv) to determine the effectiveness of converting manure to biochar and cattle manure on maize early development and, (v) to determine the effects of biochar type and application rate on early maize development. The farming system was surveyed to identify quantities of livestock manure, its availability and utilization for soil fertility amendment in cropping in the Raymond Mhlaba Municipality. The emerging results across all the villages revealed that, the mean livestock numbers were, 9.24±8.21 sheep, 9.37±8.15 goats, 7.95±7.66 cattle and 9.02±9.47 chickens. The findings revealed that 94 (82.4percent) of the respondents had access to cropland allocations in the form of outfields and homegardens. However, only 55 (48.2percent) of the respondents were currently cropping their fields. Maize was the most common crop grown followed by butternuts and potatoes. The application of manure by the respondents currently cropping their lands was only 40 (35.1percent) and the quantities used ranged from 210-1450 kg ha-1. The results further showed that the estimated total manure production was 2.9 t year-1, 0.82 t year-1, 0.04 t year-1, and 0.8 t year-1 from cattle, goats, chicken, and sheeps respectively. Drum retort method of slow pyrolysis at a temperature of 400°C was used to produce biochar from cattle, goat, sheep and poultry manure feedstocks. The biochar yields were 63percent, 72percent, 61percent and 83percent on a weight basis for the different feedstocks. The chemical properties of the biochar were significantly different from those of the manure from which they were made. Biochars that were high in Ca and K such as poultry manure biochar and sheep manure biochar indicated higher pH and electrical conductivity values. For instance, sheep manure biochar was (8.1 mS cm-1) and poultry manure biochar was (9.2 mS cm-1). The scanning electron microscopy (SEM) revealed that, the biochars had porous structures ranging from 1.23um to 5.23um in diameter which are important for water conductance and holding capacity. The target soil carbon level to determine the effects of biochar soil incorporation was 2percent and the soil had 0.7percent. Therefore, it was treated with four livestock manure biochars at application rates of 0; 53.2 t ha-1 (CMB); 48.1 t ha-1 (GMB); 50.7 t ha-1 (SMB); and 40.2 t ha-1 (PMB) based on their carbon content to supplement the soil carbon difference. The effect on soil pH was such that SMB increased to 6.44, PMB (6.45), CMB (6.54), and GMB (6.53) relative to the control which did not show any changes. An increase was also observed on Olsen P concentrations (mg P kg-1) which varied with biochar treatments: PMB (6.22), GMB (6.37), SMB (6.44) and CMB (6.44) and were significantly higher than the control. Ammonium-N(NH4+) concentrations (mg NH4+-N) were increased in biochar treatments but, no significant differences were obtained with sampling time. SMB released 7.95 mg kg-1, CMB 7.50 mg kg- 1, PMB 7.46 mg kg-1 and GMB 7.05 mg kg-1, compared to the control 3.23 mg kg-1. Maize growth in soil sampled from farmers fields in cultivation and abandoned treated with biochar without application of inorganic fertilizer did not differ with control (soil only) treatments. However, maize growth in soil treated with biochar and inorganic fertilizer was comparative to manure treatments. This resulted in a follow up study to elucidate the effects of biochar alone and was carried out with cattle, goat, sheep and poultry biochars at five application rates (0, 100, 200, 300, and 400 kg C ha-1) applied to a sandy loam and a clayey loam soil of the Oakleaf and Tukulu soil forms respectively. Post-harvest soil pH, electrical conductivity and Olsen P showed improvements in biochar treatments relative to the control. Improvements in the chemical parameters and plant growth increased simultaneously with biochar application rate. Maize growth was not affected by biochar application at different rates.
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- Date Issued: 2017
Characterization of maize biochars, their effects on soils, early maize growth and effectiveness of fertilizers
- Authors: Pinkson, Sibusisiwe
- Date: 2017
- Subjects: Soil fertility Crops and soils Biochar
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/9974 , vital:35211
- Description: The use of maize biochar in smallholder cropping systems of the Eastern Cape (EC) Province could be a strategy that helps mitigate a common challenge such as poor soil fertility in maize productivity. The current study investigated the following: a) comparison of maize biochars derived from the drum and pit kiln pyrolytic systems as soil amendments; b) effects of maize biochars on soil acidity and extractable nutrients of three arable soil types of the EC Province; c) effects of maize biochars on early maize growth and nutrient uptake; d) effect of maize biochars on the effectiveness of organic and inorganic fertilizers for improved soil quality and maize growth. Maize biochars were produced from two pyrolytic systems namely the pit and drum kiln, each maize biochar type was analyzed with respect to its chemical and physical characteristics to investigate its potential as a soil amendment. Both pyrolytic systems were monitored to identify optimum pyrolytic temperatures reached by each process. Observed peak pyrolytic temperature were 300 °C and 500 °C for the pit and drum pyrolytic systems respectively. Both maize biochar types were alkaline in nature with pH values of 8.36 (H2O) and 7.45 (KCl) and 8.95 (H2O) and 7.82 (KCl) for pit and drum biochar respectively. Electrical conductivity (Ec) of drum biochar was 199 mS /m and that of pit biochar 186 mS /m. Generally, there were no differences in the chemical compositions of the two biochar types. However, in most analysis drum biochar gave higher values in nutrient composition compared to the pit biochar. Moreover, according to SEM analysis both biochar materials consisted of an increase in pore size distribution compared to the original feedstock material. In addition, an increase in nutrient composition in the two biochar types compared to the original feedstock was also observed. In an incubation experiment, potential effects of the two maize biochar types derived from the pit and drum kiln pyrolytic systems on soil acidity and nutrients were investigated on three arable soil types of the EC Province. Three soil types investigated were obtained from the University of Fort Hare (UFH), Phandulwazi (PND) and Msobomvu (MSV). The UFH soil was a sandy loam of the Oakleaf form or Eutric Cambisol, the PND soil was a sandy loam over sandy clay a Haplic Luvisol, while the MSV soil was a clay loam of Westleigh form a Ferric luvisol. Both maize biochar types significantly (p< 0.05) increased soil pH of the three soil types in the incubation study from an average of 4.68- 7.5. Soil pH improvement was in the following order pit biochar> drum biochar> control. Also, the two maize biochar types significantly (p< 0.05) increased the release of cations namely Ca, Mg and Na however, some decrease in nutrient concentrations were observed due to increase in pH levels at the later stage of the study. Biochar incorporation increased extractable P release from 30- 40 mg P/kg to an average range of between 120- 160 mg P/kg across all soil types. A glasshouse study was also conducted investigating the effect of different biochar rates of the two maize biochar types used in the previous studies on early maize growth and nutrient uptake, same soil types were used as those in the incubation study. Biochar was applied at application rates of 0, 100, 200 and 300 kg C/ha of biochar. The glasshouse experiment consisted of two cycles, each with a six week period of monitoring maize seedling growth development. Generally, a significant increase in maize growth parameters such as plant height, stem girth, number of leaves and leaf area increased after biochar additions compared to the control. Both biochars significantly improved maize seedling growth at an application rate of 200 kg C/haHowever, the two biochar types displayed varying impacts on maize growth due to influence of soil type and biochar application rates. Nutrient- uptake of Ca, P, Na and Mg showed to improve at an application rate of 200 kg C/ha for both biochar types showing a 50 percent increase compared to the control. Nutrient- uptake patterns for P, Ca, Mg and Na differed across all soil types, mainly due to changes in pH and Na levels which were influenced by increased biochar concentrations resulting in nutrient deficiency. Another glasshouse experiment aimed at investigating the effects on the two maize biochar types on influencing the effectiveness of both organic and inorganic fertilizers for improved early maize growth and soil productivity. Biochar was applied at an application rate of 400 kg C/ha of biochar, fertilizer was applied at application rates of 0, 10, 20, 30 and 40 kg N/ha and manure at 0, 10, 20, 30 and 40 t/ha respectively. The glasshouse experiment consisted of two cycles, each with a six week period of monitoring maize seedling growth development. In the 1st cycle, manure rate of 40 t/ha resulted in the highest plant height of maize seedlings grown in the glasshouse, biochar type also showed to influence plant height. After the 1st harvest Mg, K and P levels improved at 30 t/ha, Na at 20 t/ha and Ca 40 t/ha of manure. Plant height and stem girth improved at 30 kg N/ha of fertilizer, however, nutrient levels for Ca, K and Mg decreased after the 1st harvest, while Na levels increased. Nutrient uptake was the highest for Mg and Na at 40 kg N/ha while for Ca at 30 kg N/ha of fertilizer. During the 2nd cycle plant height was the highest at 30 t/ha of manure, and effect of manure rate was significant (p<0.05) for number of leaves, plant height and biomass. Whereas, manure rate and biochar type effect were insignificant (p>0.05) for pH, Ec and nutrient uptake changes. Maize seedling showed significant response to fertilizer 40 kg N/ha for most of the growth parameters measured (P<0.05), except for germination percentage. All treatments investigated had no effect on germination percentage. The two biochar types showed significant (p<0.05) effects on soil pH and Ec. Drum biochar was slightly better performing than pit biochar. Results obtained from the various studies suggests that maize biochars derived from the pit and drum pyrolytic systems are potential soil amendments in correcting soil acidity and nutrient deficiency in the EC Province. Both biochar types have shown abilities to improve early maize growth and effectiveness of fertilizers in maize based systems of the EC Province. However, some variations in soil fertility and early maize growth were observed as a result of the soil type response towards the two biochar applications. This could also have risen as a result of a number of factors such as the nutritional composition of biochar material, initial soil type chemical composition, biochar and fertilizer application rates and time taken or period to complete each study. Therefore, further experiments should be conducted to validate these results, preferable having longer periods of study, moreover, field experiments. In addition, investigations on potential feedstock materials such as animal wastes used as biochar in the EC Province can be conducted.
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- Date Issued: 2017
Characterization of Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus (MRSA) in selected recreational marine waters and beach sand in the Eastern Cape Province, South Africa
- Authors: Ankabi, Olufemi Emmanuel
- Date: 2017
- Subjects: Marine microbiology -- South Africa -- Eastern Cape Staphylococcus aureus infections -- South Africa -- Eastern Cape Pathogenic microorganisms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4992 , vital:28915
- Description: Staphylococcus aureus is a Gram-positive bacterium predominantly found on human skin and in nasal passages with 20 to 40 percent of the population carrying this organism. Although S. aureus is an unspectacular, non-motile coccoid bacterium, it is a perilous human pathogen associated with both nosocomial and community-acquired infections and it is increasingly becoming virulent and resistant to most antibiotics. It is responsible for several infections such as osteomyelitis, toxin-mediated diseases and bacteraemia, with severe infections arising from strains harbouring antibiotic resistance genes together with virulence genes. S. aureus has been largely confined to hospitals and long-term care facilities, but it is now emerging in the community in places such as recreational beach waters, and occurring in healthy individuals with no associated risk factors. This organism has been reported to be released by swimmers in beaches, suggesting that recreational waters are a potential source of community-acquired S. aureus infections. It is possibly the pathogen of greatest concern due to its intrinsic virulence, its capacity to cause various life-threatening infections, and its ability to adapt to varying environmental conditions. This study was aimed at characterizing S. aureus and methicillin-resistant S. aureus (MRSA) in Port Elizabeth, Port Alfred, Kenton-on-sea and East London beaches of the Eastern Cape Province of South Africa. This was done by investigating the occurrence, antibiotic susceptibilities, antibiotic-resistant genes and virulence genes profiles of S. aureus in the selected beaches. To achieve this aim, 249 beach sand and water samples were obtained from the beaches during the period of April 2015 to April 2016. Physico-chemical parameters of beach water was investigated on site using a multi-parameter ion specific meter during sample collection. Samples were filtered and inoculated on m-Endo agar, m-FC agar and bile aesculin azide agar for total and faecal coliform as well as Enterococci respectively. For isolation of S. aureus and MRSA, samples were cultured on Mannitol salt agar and Staph 24 agar. S. aureus was identified using morphological, Gram staining and molecular (PCR) methods. The isolates were further characterized by determining their antimicrobial resistance profiles, antibiotic resistant genes (mecA, rpoB, blaZ, ermB and tetK genes) and detection of virulent genes encoding intracellular adhesion (icaA), enterotoxin (seaA) and cytolytic toxins (PVL). The majority of study sites passed the directives of physico-chemical standards levels set by WHO during the study period. A total of 143 presumptive isolates were obtained of which 30 (30 percent) were confirmed as S. aureus with 22 (73.3 percent) of these confirmed isolates from marine water and 8 (26.7 percent) from marine sand. Upon culturing on MRSA 2 agar, 15 (50 percent) of isolates showed phonotypic resistance to methicillin. Based on Antimicrobial susceptibility tests, (22/30) 73.3 percent of the isolates showed phonotypic resistance to oxacillin. Out of the 30 isolates, 16 (53.3 percent) were mecA positive and were considered methicillin-resistant S. aureus. S. aureus showed high susceptibility to gentamycin, cefoxithin, levofloxacin, ciprofloxacin, imipenem, and chloramphenicol. A large proportion (36.67 percent to 96.7 percent) of the S. aureus isolates was resistant to penicillin G, ampicillin, oxacillin, tetracycline, clindamycin, rifampicin, vancomycin, sulfamethoxazole-Trimethoprim and erythromycin. Multiple antibiotic resistance (MAR) phenotypes were generated from 7 S. aureus isolates showing resistance to three or more antibiotics. The mecA, rpoB, blaZ, ermB and tetM genes coding for methicillin, rifampicin, βeta-lactam, erythromycin and tetracycline antibiotics resistance was detected in 5 (22.7 percent), 11 (45.8 percent), 16 (55.2 percent), 15 (71.4 percent) and 8 (72.7 percent) respectively. The PVL, icaA and seaA genes coding for virulent determinants were detected in 50, 20 and 13.3 percent of the confirmed isolates respectively. Physico-chemical and faecal indicator bacteria results obtained from this study can assist municipal authorities in developing appropriate management strategies for beaches in the study area. The findings of this study showed that the investigated beaches were contaminated with toxigenic and multi-drug resistant S. aureus strains. This emphasizes the need for the implementation of better control measures to reduce the occurrence of antibiotic resistant S. aureus and of virulent S. aureus strains in recreational waters. In our study it was established that the potential of recreational waters to be reservoirs of S. aureus should not be taken for granted, and it is important that beach goers be educated about this organism as well as other related pathogens that could affect human health, especially immuno-compromised individuals. The community should be educated on antibiotic stewardship and the detrimental effects of antibiotics abuse.
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- Date Issued: 2017
Comparative studies of different ant-hypertensive treatments used for cardiovascular disease patients : a case study of public health facility in the Eastern Cape South Africa
- Authors: Abiodun, Oluwatoyin Victoria
- Date: 2017
- Subjects: Survival analysis (Biometry) Cardiovascular system -- Diseases
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13205 , vital:39519
- Description: Discovery has shown that many deaths arising from cardiovascular disease often show early symptoms of high blood pressure, which makes it the leading risk factor of cardiovascular diseases. There is a distressing rate of 970 million hypertensive patients worldwide, a higher ratio of 640 million are from developing countries, if proper measures are not taken, there will be a higher growth of cardiovascular disease in adults by 2025. The focus of this study was to compare the therapeutic potentials of the anti-hypertensive therapies, drug A (amiloride + furosemide) and drug B (hydrochlorothiazide + enalapril) used in the treatment of cardiovascular disease patients for their capability to lengthen remission duration and survival time. All patients were diagnosed with a type of cardiovascular disorder, therefore patient records were followed up and blood pressure was being monitored for a period of two years. The retrospective data gotten from the public health facility was analysed using survival analysis methods. The results revealed that there was no statistical significance in the distributions of the length of remission and survival time of drug A and drug B patients. Also, in the age category, CVD patients that are 55 and above recover faster with drug A, while CVD patients below 55 shows a better survival with drug B. Then again, estimates from the gender category show a better survival in males using drug A, while the females thrive slightly better using drug B. Among all the risk factors considered in the study, only employment status showed a strong impact on survival time (remission). The findings from this study may help to formulate interventions and strategies that will increase the lifespan of cardiovascular patients and reduce early mortality due to cardiovascular diseases.
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- Date Issued: 2017
Computational design of a smart and efficient control system for a residential air source heat pump water heater
- Authors: Yongoua Nana Joel
- Date: 2017
- Subjects: Heat pumps -- Specifications Water heaters Renewable energy sources
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4582 , vital:28435
- Description: An air source heat pump (ASHP) water heater is a renewable and energy efficient hot water heating technology. ASHP water heaters are fast gaining maturity in the South African market and in Africa at large due to their low energy consumption (about 67 percent lower than conventional geysers), relatively low installation and operation cost, their environmental friendly nature and possibly the ease to retrofit with the old inefficient technologies. Furthermore, ASHP water heaters make use of some of the most recent advancement in refrigeration technologies enhancing their performance through a wide range of weather conditions. However, residential ASHP water heaters which come at the tail of a series of highly sophisticated models still harbour primitive control designs. One of such control system is the intermittent (on/off) control whereby the ASHP unit responds to a temperature differential threshold rather than instantaneous temperature fluctuations. Unfortunately, this control method contributes to a rapid deterioration of the compressor and other actuators due to high starting current during transient states and partial loading. Capacity control is a better alterative as it offers a more reliable system’s performance as well as a better protection for the system components. However, the drawbacks of implementing such a technology on residential ASHP water heaters is the initial purchasing cost. We use a systematic approach in this research to circumvent the purchasing cost and complete redesign hysteresis. The first step was centered around a hypothetical analysis of the performance of the heat exchangers in a bid to uncover the weakness during the operation of a residential ASHP water heater. It was observed that at ambient temperatures above 22°C notably during summer and winter afternoons, water only harnesses about 75 percent of the total heat rejected. Furthermore, the actuators keep doing work for about 15-20 minutes even after the heat transfer process has ceased completely. Following these observations, a sequential flow algorithm was developed aimed at matching the consumption point to weather variables like ambient temperature and secondly to most efficiently synchronize actuator components for a better energy management. This novel control method can save up to 58 percent of energy compared to the conventional on/off method during summer afternoons and averagely 20 percent during the rest of the day. It also has the merit to be cost effective as it barely requires no component retrofitting.
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- Date Issued: 2017