Pursuing socio-economic rights in post-apartheid South Africa : a case study of the Buffalo City metropolitan municipality, Eastern Cape province
- Authors: Makapela, Sicelo Leonard
- Date: 2017
- Subjects: Civil rights -- South Africa -- Eastern Cape Human rights -- South Africa -- Eastern Cape Social justice -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/12881 , vital:39387
- Description: The overall aim of this research was to investigate the extent to which a wide range of socio-economic rights such as housing, education, healthcare, water, sanitation, electricity, food security, social security and the right to work are enjoyed in the Buffalo City Metropolitan Municipality in the Eastern Cape Province. South Africa has nine provinces and the Eastern Cape is considered as one of the poorest with high levels of the triad of poverty, inequality and unemployment. The study used a rights-based approach (RBA) which examines the quality of human life from a rights perspective. Survey questionnaires were distributed to a sample of 500 respondents who were selected through a cluster random sample and six in-depth interviews were further conducted with government officials who were selected through purposive sampling. The study was guided by four main objectives and the first sought to explore citizens’ perceptions of the intersection between service delivery protests and socio-economic rights. The findings revealed that the majority of the survey respondents had no sense of the intersection between service delivery and socio-economic rights. Many did not know anything about the South African Constitution and could not relate to its content. Most critically, the majority did not know the socio-economic rights enshrined in the Constitution. The majority was more comfortable with the phrase service delivery over socio-economic rights and this was so because the former was the most commonly used by the politicians, the media and community leaders. In short, the majority of respondents had a poor understanding of the Constitution and socio-economic rights. On the contrary, the in-depth interview participants showed an excellent knowledge of the Constitution and its socio-economic rights content and saw a strong intersection between service delivery protests and socio-economic rights. Both the questionnaire respondents and the in-depth interview participants regarded employment as the most import demand that the government should address urgently. The second objective sought to describe the extent to which the government has fulfilled various rights. Caution was needed in interpreting this objective. While the majority of the questionnaire respondents had rated the government’s efforts negatively in many socio-economic rights, however, further probing revealed that the government had done well. The questionnaire respondents continued to rate the government negatively even in instances where they indicated that the government had done well. Thus, the findings revealed mixed results that the government had done pretty well in some, not so well in others and very bad in some cases. The in-depth interview participants, on the contrary, were all positive about the government’s fulfilment of various socio-economic rights and rated it favourably. The findings, therefore, dismiss the views shared by the majority of the questionnaire respondents that the government had fulfilled various socio-economic rights to a smaller extent and equally challenge the idea that the government was highly successful in all its efforts to fulfil various socio-economic rights. The evidence shows that the government was successful in some and not so in others. Third, the study revealed a number of factors affecting the enjoyment of socio-economic rights in the Buffalo City Metropolitan Municipality including lack of democracy, lack of human rights knowledge, poor performance by Ward Councillors etc. Finally, the study identified a number of challenges which inhibited the enjoyment of socio-economic rights and these included corruption, crime, lack of participation by the poor in decision-making, alienation of the masses, but the most single serious threat identified by both the questionnaire respondents and in-depth interview participants was the rampant corruption. Most disturbingly, the respondents did not know what to do, how or where to go to claim their rights. This was revealed by the majority who pointed out that they have never approached the government, Constitutional Court or any court and don’t talk to their Ward Councillors about socio-economic rights. Moreover, they have never used the rights language during service delivery protests. All these point to the significant lack of knowledge about rights despite being familiar with the phrase (amalungel’ethu), a Xhosa expression for our rights. Thus, the questionnaire respondents were simply passive citizens and were not doing enough to pursue their socio-economic rights. Since corruption has been indicated as a major challenge affecting the enjoyment socio-economic rights, it is therefore recommended that alternative institutions should play a critical role not only in exposing corruption but the state should prosecute those found guilty of corruption especially on issues that affect the enjoyment of socio-economic rights. It is also recommended that there should be a dialogue between community representatives and the citizens to talk about socio-economic rights during community meetings. The study further, recommends that human rights education should be incorporated in school curricula, especially in secondary and tertiary institutions. Finally, it is recommended that the development of a comprehensive tool for monitoring and evaluating socio-economic rights should be put in place. At present, no such tool exists.
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Qualitative assessment of the performance and challenges of the recapitalization and development programme : the case of Buffalo City metropolitan municipality, Eastern Cape, South Africa
- Authors: Maka, Loquitur
- Date: 2017
- Subjects: Mentoring--South Africa--Eastern Cape Land reform--South Africa--Eastern Cape Agricultural assistance--South Africa--Eastern Cape
- Language: English
- Type: Thesis , Masters , Agricultural Extention
- Identifier: http://hdl.handle.net/10353/11619 , vital:39090
- Description: The Recapitalization and Development Programme (RADP) is a tool which seeks to provide black emerging farmers with the social and economic infrastructure and basic resources that are required to run a successful agricultural business. The RADP’s objectives include: to increase production, to guarantee food security, to graduate emerging farmers to commercial farmers and to create jobs opportunities within the agricultural sector. But above all, the unstated objective of the RADP is to revive failing land reform projects. The aim of the study was to evaluate the impact of the RADP, specifically looking at land reform beneficiaries in Buffalo City Metropolitan Municipality. Qualitative research was conducted in the form of seven in-depth case studies of RADP-supported land reform projects, together with interviews with four RADP mentors and three government officials. Some of the challenges in the farms before RADP funding was received included: little or no income, high mortality rate of livestock, and lack of skills. The study revealed that the RADP funds contribute to making a difference to the beneficiaries’ activities and provide the necessary infrastructure and equipment for sustainable commercial production. Even though there were mostly positive responses from the beneficiaries, some were dissatisfied with their mentors because the feel that some mentors do not understand their role and responsibilities. Most beneficiaries who appreciated the mentorship programme seem to be older people. However, the impact as mentioned by the mentors is not sustainable due to the short duration of support by the government both in terms of the mentorship and financial support to the projects.
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Quality indices of the Eastern Cape beach waters in Buffalo City Metropolitan Municipality, Eastern Cape, South Africa
- Authors: Mani, Sinalo
- Date: 2017
- Subjects: Waterfronts -- Recreational use -- South Africa -- Eastern Cape Water quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/19054 , vital:40108
- Description: Surface waters constitute important sources of water and serve for agricultural, recreational and industrial purposes; however, the vulnerability of such water sources to pollution presents serious ecological, public health and economic problems of global concerns. Beach water quality is monitored to reduce the risk of recreational waterborne illnesses. Water samples were collected between September 2014 and August 2015 at Eastern beach and a total of 5 physicochemical parameters, counts of faecal coliforms, E. coli and Enterococcus isolates were determined using standard analytical procedures. Confirmed Escherichia coli isolates were assessed for virulence genes associated with pathogenic E. coli strains responsible for intestinal and extra-intestinal infections. Recovered E. coli isolates were then interpreted for their antibiogram profiling using disk diffusion method. On the other hand, the recovered Enterococcus isolates were characterized for Enterococcus speciation of key species that are normally implicated in infections and further assessed for their antibiogram profiling by disk diffusion method. The physicochemical qualities of the water ranged as follows: turbidity (1.4 to 36.8 NTU); pH (7.0 to 8.6); temperature (14.5 to 24.5 ºC); total dissolved solids (TDS) (5.2 to 46 mg/L) and electrical conductivity (EC) (8.2 to 70.7 μS/cm). Microbiological qualities obtained were as follows: faecal coliform (101 to 103 CFU/100 mL); Escherichia coli (101 to 103 CFU/100 mL); and enterococci (101 CFU/100 mL to 102 CFU/100 mL). Only 38/104 (37 percent) harbored at least 1 virulence gene while 66/104 (63 percent) of the isolates harbored none. Most frequent virulence genes were eae for EPEC/EHEC, fliCH7 for EHEC, ibeA for NMEC, while daaE for DAEC and ipaH for EIEC were discovered in three isolates each; bfp for EPEC was detected in 2 isolates and lt gene for ETEC in one isolate. EAEC and UPEC genes were not detected in all the isolates. All tested isolates were resistant to ampicillin, tetracycline, gentamycin and chloramphenicol (85 percent), ciprofloxacin (78 percent), trimethoprim (54 percent) and norfloxacin (54 percent) and the Multiple Antibiotic Resistance Index for all isolates ranged between 0.6- 1.0 with the average being 0.8, which exceeded the threshold value of 0.2. Among the 96 recovered Enterococcus isolates, 55 percent were identified as E. faecium, 22 percent were E. hirae, 2 percent were E. durans and 21 percent were uncharacterized Enterococcus species. E. faecalis and E. casseliflavus were not detected amongst the isolates. All isolates were resistant to vancomycin, erythromycin and chloramphenicol. While the resistance against other antibiotics followed the order: tetracycline (97 percent), gentamycin (96 percent), ciprofloxacin (93 percent), linezolid (91 percent), ampicillin (91 percent) and trimethoprim (62percent). Only 6 percent of the isolates were susceptible to trimethoprim and the MAR index for all isolates ranged between 0.6- 1.0 with the average being 0.9 which greater than 0.2, suggesting that these bacterial strains originates from environments with high use or contamination of antibiotics.
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Quality indices of the Nahoon beach and canal in Buffalo City Metropolitan Municipality, Eastern Cape, South Africa
- Authors: Ebomah, Kingsley Ehi
- Date: 2017
- Subjects: Pathogenic bacteria -- South Africa -- Eastern Cape Water quality -- South Africa -- Eastern Cape -- Measurement Water -- Microbiology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8122 , vital:31525
- Description: Faecal indicator bacteria have long been recommended for usage in water quality monitoring of various water sources including surface water. A large number of people in different parts of the world often engage in recreational and other commercial activities at the various beaches along the coastal lines, most especially, during summer season and festive periods. It is generally assumed that beach water is safe all the times, however, there have been increasing reports of beach and other coastal water pollutions because of rising anthropogenic activities around coastal areas globally. The presence of pathogens in faecal contaminated beach water either directly or indirectly increases the risk of human exposure which may result in skin infections as well as the ingestion and transmission of multidrug resistant pathogens. Microorganisms may gain entry into beach water directly from improperly treated final effluents released by wastewater treatment plants and from agricultural runoffs and/or faulty drainages. The aim of this study was to evaluate the quality indices of the Nahoon Beach and canal waters in the Eastern Cape Province of South Africa. In order to achieve this aim, the objectives of this study were as follow: to determine the seasonal variations of the physicochemical characteristics of the Nahoon beach and canal waters, to assess the microbiological quality of the beach water by assessing the prevalence of potentially E. coli and Enterococcus species, and to evaluate the antibiogram profile of the E. coli pathotypes and Enterococci species recovered from the beach water samples. Water samples were collected bi-weekly for a period of twelve months, during which on-site physicochemical analyses were carried out. Bacteriological assessment was performed using the membrane filtration technique and the necessary incubation conditions were followed. Identification of the target organisms was done by molecular based methods using PCR (polymerase chain reaction) while antibiotic susceptibility testing was done using the disk diffusion method. During the spring season (August to October) and periods of festive activities (December, January and March), it was observed that turbidity was at its highest, consequently, influencing total dissolved solids and a rise in the values of pH and electrical conductivity. Microbiological qualities assessed follow the order: Escherichia coli (101 – 103 CFU/100ml) and Enterococcus (101 – 102 CFU/100 ml). The results show that 41.2percent (107/260) of the presumptive E. coli isolates were positive for uidA gene. A total of 73 out of 107 (68.2percent) PCR-confirmed E. coli isolates were observed to belong to different pathotypes while 59percent (102/172) of the presumptive Enterococcus strains isolated were positive for SodA gene (Enterococcus spp.). Out of 102 enterococci isolates, 45 strains were identified as species (E. faecalis and E. faecium) and these were subjected to antibiotic susceptibility testing. The E. coli strains exhibited a frequency of 100percent resistance against ampicillin while the Enterococcus strains also showed 100percent resistance against vancomycin and linezolid. Target genes eae 11 (10.3percent); ipaH 14 (13.1percent); ibeA 48 (44.9percent) that encode pathogenicity in E. coli were successfully amplified by PCR suggesting that the isolates are potentially pathogenic strains whereas Enterococcus spp. including Enterococcus faecalis 26 (25.5percent) and Enterococcus faecium 19 (18.6percent) were also identified in the water samples. In this study, the phenotypic antibiogram profiles of the E. coli isolates revealed that all 73 (100percent) of the pathotypes were resistant to ampicillin, 67 (91.8percent) were resistant to amikacin, gentamicin and ceftazidime while about 61 (83.6percent) and 51 (69.9percent) were resistant to tetracycline and ciprofloxacin as well as trimethoprim respectively. About 21.9percent (16) of the E. coli isolates exhibited multiple antibiotic resistances with 100percent being resistant to eight antibiotics whereas multiple antimicrobial resistances were observed in 14 (31percent) of the enterococci strains and the most predominant profile was the simultaneous resistance to ampicillin, penicillin and vancomycin. The results obtained in this study show that the beach water generally did not comply with the set guidelines. The results also suggest the possible survival and prevalence of potentially virulent E. coli as well as Enterococcus strains in the aquatic environment which may be a cause of concern for public health. Monitoring of the quality of surface water and antimicrobial resistance (AMR) in bacteria is of great importance and has clinical and human health significance. Nonetheless, this study underscores the need for more detailed study of other waterborne pathogens of health importance including enteric viruses to ascertain the safety of the beach for human use.
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Reform-based approaches in the learning and teaching for conceptual understanding of calculus for diploma studies at south african university
- Authors: Coetzee, Johanna
- Date: 2017
- Subjects: Calculus Mathematics -- Study and teaching
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/4959 , vital:28878
- Description: This research tested whether Reform-Based Approaches (RBAs) in the learning and teaching of calculus could lead to improved conceptual understanding. The study adopted positivistic paradigm, quantitative approach and pre- and post-test in a quasi-experimental design. The theoretical framework was Constructivism. The interventions were grounded on learner-centred RBAs including Interactive Engagement (IE), Peer Discussion (PD) and Good Questions (GQ). The experimental group comprised 119 volunteering students from a population of 461 registered for Mathematics as a service subject for the National Diploma (ND) in science or engineering at a South African university. Those not in the experimental group were taught through teacher-centred traditional approaches which have been the norm. However, only 71 out of those in the traditionally taught cohort volunteered to write both Pre- and Post-tests. As such, the total number of subjects in the study was 190, i.e., 119 from the Reform-Based cohort and 71 from the Traditional cohort. The instrument, the Calculus Concept Inventory for Technicians (CCIT), consisted of 19 questions on functions, differentiation and integration. Based on a pilot test, the instrument was improved. The Reform-Based cohort did not receive any participation reward and test scores did not contribute to promotion scores. The students wrote Pre-tests in the second week after commencement of lectures and Post-tests during the last week of lectures. The data were analysed using various statistical tools, tests and measures such as Chi-squares, Student t-tests, Pearson’s Product Moment correlation, Cronbach alpha, KR-20, the Difficulty Index, and Item Discrimination Point Biserial Index (PBI). The raw gain and normalised gains were also employed in data analyses. The main finding of this study was that RBA made a significant impact on the conceptual understanding of calculus of the experimental group. The gain achieved by the experimental group was in a low range and corresponded to the low use of IE (25% of contact time). A combination of RBA with Traditional teaching is recommended. Also, RBA will be most successfully introduced if supplemented and complemented through supportive environments.
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Removal rate of endocrine disruptors (phthalates and phenolic compounds) in effluents of selected wastewater treatment plants operated under different treatment technologies in the Eastern Cape, South Africa
- Authors: Salaudeen, Taofeek Gbenga
- Date: 2017
- Subjects: Water -- Purification Phenols
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8552 , vital:33113
- Description: The presence of phthalate esters (PAEs) and certain phenolic compounds widely known as endocrine disruptors in environmental waters such as treated wastewaters constitutes health hazard to human and aquatic lives. Unfortunately, wastewater treatment plants (WWTPs) only partially remove these synthetic chemical compounds from wastewater. In order to forestall the health challenge faced by rural dwellers, which rely on surface water for their daily needs, the present study embarked on investigating these endocrine disruptors in Municipal wastewater in the Amathole and Buffalo Districts in the Eastern Cape, South Africa and their removal rate by different WWTP technologies. One WWTP each from Adelaide, Alice, Bedford, Berlin and Seymour, using activated sludge (AS), trickling filter (TF), and oxidation pond (OP) technology were randomly selected. Some physicochemical parameters of these wastewaters were determined on-site using standard methods and the extraction method for endocrine disrupting chemicals (EDCs) in water was validated using solid phase extraction (SPE). Extracts were analysed using gas chromatography-mass spectrometer (GC-MS). Nine phenolic compounds; phenol (PH), 2-chlorophenol (2-CP), 2,4-dimethylphenol (2,4-DMP), 2,4-dichlorophenol (2,4-DCP), 4-chloro-3-methylphenol (4-C-3MP), 2-nitrophenol (2-NP), 4-nitrophenol (4-NP), pentachlorophenol (PCP), 2,4,6-trichlorophenol (2,4,6-TCP) and six priority PAEs namely; dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP), di(2-ethyl hexyl) phthalate (DEHP), and di-n-octyl phthalate (DOP) were the investigated EDCs. PAEs were extracted from dried sludge samples in an ultrasonic bath using dichloromethane. Some physicochemical parameters of the wastewater assessed revealed that treatment processes of AS, TF, and OP reduced turbidity, total suspended solids (TSS), total dissolved solids (TDS), and electrical conductivity (EC) while dissolved oxygen (DO) was increased. There was no significant influence on temperature and pH across the sampling points. Except for turbidity, the quality of effluent released mostly falls within South Africa standard limits for domestic and recreational water. The nine phenolic compounds were detected across the sampling points for all the WWTPs at different frequencies. The prominent phenolic compounds were 2-NP, 4-C-3MP, PCP, and 2,4-DMP with concentrations ranging from 3.3 (2,4-DMP) – 83.0 μgL-1 (4-C-3MP) in the influents. However, their concentrations in the effluents and receiving water bodies were below tolerable limits of 5 μgL-1 set by the US Environmental Protection Agency (USEPA) and the European Union (EU) for domestic use. The removal capacities of the WWTPs varied between 33 and 96 percent. The six PAEs were detected in all water samples from all the WWTPs. DBP was the most abundant compound in all the sampling points and sometimes DEHP in some receiving waters. The maximum detection for DBP in influent, effluent, downstream and sludge were 2,488 μgL-1 (Alice), 26.47 μgL-1 (Adelaide), 115.3 μgL-1 (Seymour) and 1,249 μg/g dw (Alice), respectively. DEHP was the highest detected PAE in the upstream 17.53 μgL-1 (Seymour). There was a notable reduction of all PAEs in the final effluent with a removal efficiency which varied as much as 61.9 – 99.5 percent except for AS in Seymour which operated a single tank system (27.3 - 93.7 percent). Removal mechanisms continued more on adsorption on settling particles and sludge than biodegradation as this study found a high positive correlation between TSS, turbidity and PAEs removal. The concentrations of PAEs detected in the receiving waters were above 1.3 and 3μgL-1 limit standard set by the EU and USEPA, respectively for DEHP in surface water. Similarly, the average concentrations of DBP, BBP, DEHP and DOP which vary as much as 25.97 (BBP) – 1249 μg/g d.w (DBP) in sludge samples were above EU legislation of 100 μg/g d.w. for agricultural use. AS technology, showed a better performance in the removal of PAEs (77 – 99 percent), followed by TF (76 – 98 percent) and OP (61 – 98 percent). In conclusion, the PAE concentration in the WWTP effluents impacted negatively on the receiving water bodies and sewage sludge unlike the phenolic compounds that were notably reduced below the acceptable limits. Perhaps, due to the meagre amounts of the phenolic compounds that was detected entering the WWTPs. In order to avert the potential health risk to aquatic organisms’ and rural dwellers, it is exigent that constituted authorities gather more information on micro-pollutants in the environment as a basis for regulations on the use of these dangerous chemicals in industries.
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Richard Charles Nicholas Branson : a psychobiographical study
- Authors: Preston, Amanda Lorraine
- Date: 2017
- Subjects: Branson, Richard Charles Nicholas, -- 1950- Businessmen -- Great Britain -- Biography Success in business
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/5543 , vital:29318
- Description: Unique individuals are fascinating as we all want to be successful. There is thus a need to understand, unpack and share the psychological development and traits that allow some people to become sui generis, and to learn from them. Psychobiographical research is a qualitative approach that can be utilised to uncover the story of such an individual life, resulting in greater understanding of the psychological concepts underpinning the person. This form of study is invaluable, and involves applying psychological theory to lives completed or unfinished, enabling the development and testing of developmental theories. Richard Branson (1950-present), an entrepreneur, adventurer, philanthropist and family man is the single psychological subject chosen in this study. Branson was selected based on interest value, his uniqueness and the lack of a specifically academic and psychologically focused case study on his life. The primary aim was to explore and describe Branson’s personality development across his life, to date. This was achieved by applying both Maslow’s (1954, 1970) theory of optimal development and Adler’s (1929, 1956) Individual Psychology theory to provide a comprehensive idiographic interpretation of the development of Branson. To achieve this, the case study utilised the systematic and consistent collection, analysis and interpretation of life history materials, highlighting three areas of development, namely Childhood, Adolescence and Adulthood. The theoretical frameworks were used to discern, transform and reconstruct his life into a coherent and illuminating narrative of his psychological movement through life. Alexander’s (1988; 1990) model of identifying salient themes was used to analyse data for analytical generalisation (Yin, 2009). The conceptual framework derived from the theoretical perspective was constructed to organize, integrate data, and guide the presentation and discussion of findings of the study in an integrative and comprehensive manner. The findings suggest both Maslow’s and Adler’s theories considered the biopsychosocial context in Branson’s personality development and, at least to some extent, supported concepts indicative of progression toward optimality through having met the needs of the ego actualisation of his self, toward transcending selfishness and attaining altruism and social interest. The study of Branson’s personality development has provided a positive demonstration of the value of Maslow’s (1970a) and Adler’s (1929, 1956) theories to understand the process of development. It has further highlighted the unique trajectory of an individual’s life, contextualized, as well as the possibility of being agents in our own lives and despite challenges, able to become our own idiosyncratic best. The study also highlights the need, at a macro level, for governments to assist those unable to satisfy basic needs such as food, shelter and safety, to set an imperative, to aid those who struggle if a country and its people are to be uplifted. In terms of Adlerian theory, the study highlights the importance of family and early experiences in supporting the earliest years of children to assist them to develop an identity that is healthy and socially useful. Finally, recommendations were made for future research utilising a psychobiographical research design to uncover, illuminate and reconstruct the lives of outstanding and interesting individuals.
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Rights as trumps in African communitarian ethics
- Authors: Nwogbo, Johnbosco
- Date: 2017
- Subjects: Communitarianism Human rights Social values
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10353/12282 , vital:39249
- Description: The notion of rights is among the most basic ideas of contemporary political philosophy on the continent and elsewhere. Although rights are common-place in political philosophy it is fair to say that the discussion around it has been nothing short of contested. On the whole, there have been two kinds of questions to which most of the discussion about rights in political philosophy have been answers, namely, (i) what are rights?, and (ii) to what do people have rights? The first has to do with the nature of rights, while the second has to the nature of that to which people may be said to have rights. This research falls neatly within the parlance of the first kind of questions (i.e., the question of what rights are). Specifically, in this research, I am concerned with the question of whether the radical and moderate African communitarian rights theses of Ifeanyi Menkiti and Kwame Gyekye measure up to what rights are commonly understood to be. I argue that if rights are trumps, which override competing societal and communal considerations, then Menkiti’s and Gyekye’s theories of rights fall short of this fairly standard and typical conception of rights.
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Ruthenium sulphide nanoparticles derived from tri-dithiocarbamato ruthenium (III) complexes : synthesis, optical and structural studies
- Authors: Mbese, Johannes Zanoxolo
- Date: 2017
- Subjects: Nanoparticles Ruthenium compounds
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/15420 , vital:40406
- Description: The present Thesis pioneer the application of single-source molecular precursor method for the synthesis of ruthenium sulfide nanoparticles using a series of novel self-prepared single-source molecular precursors. The preparation of precursors involved the design and synthesis of compounds containing all the desired elements required within the coordination compound. Good precursors are tailored to give reproducible, clean decomposition at moderate temperatures, leading to high quality, defect free, mono-dispersed nanoparticles. Nine (9) homonuclear tris-dithiocarbamato ruthenium(III) complexes, [Ru(S2CNR2)3] were prepared from a stoichiometric reaction of RuCl3·H2O with self-prepared dithiocarbamate ligands at room temperature in a molar ratio of Ru3+: Ligand of 1:3. Dithiocarbamate ligands were derived from a stoichiometric reaction of carbon disulfide with (aniline, N-allylmethylamine, p-toluidine, p-anisidine, N-ethyl-m-toluidine, piperidine, morpholine, di-isopropylamine, and diallylamine) in the presence of concentrated ammonia or potassium hydroxide in ice cold bath. The dithiocarbamate ligands and complexes were characterized by elemental analyses, UV-Vis, Fourier transform infrared spectroscopy (FTIR), 1H- and 13C-NMR spectroscopy. Thermogravimetric analyses (TGA) was used to study the decomposition profiles of the precursor complexes. The results obtained from the TGA of precursors showed that the complexes decompose to ruthenium sulfide nanoparticles. The FTIR spectra of the ligands revealed prominent strong absorption bands ascribed to v(N-H) stretching vibrations and also confirm the bidentate coordination of the dithiocarbamate ligands. Ruthenium(III) complexes show absorption spectra in the visible region that exhibit bands attributed to n → π* electronic transitions located on the sulfur atoms located in the S–C–S and N–C–S chromophores of the bidentate dithiocarbamate ligands respectively. The absorption spectra also confirmed the geometry of ruthenium(III) complexes to be octahedral. The proposed structures of dithiocarbamate ligands and ruthenium(III) complexes were confirmed by the 1H- and 13C-NMR. The complexes were used as single-source molecular precursors for the synthesis of ruthenium sulfide nanoparticles. The structural and optical properties were studied using transmission electron microscope (TEM), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), UV-Vis absorption and photoluminescence (PL) spectra. FTIR revealed that Ru2S3 nanoparticles are capped through the interaction of the –NH2 group of hexadecylamine HDA adsorbed on the surfaces of nanoparticles and it also showed that oleic acid (OA) is acting as both coordinating stabilizing surfactant and capping agent. The XRD confirmed the successful formation of Ru2S3 nanoparticles induced by the thermal decomposition of series of [Ru(S2CNR2)3] complexes. The diffraction peaks: 2θ = 29.43, 40.54, 49.33, 51.86, 61.92, and 75.94 were assign the Miler indices (hkl) to be (111), (211), (220), (300), (222) and (330) reflections, respectively, and were found to be in agreement with a cubic crystal structure reported in database file of (JCPDS 19-1107). The particle sizes estimated from Scherer's equation were found in a range between 2.5 and 4.9 nm. EDS spectra reveal that the prepared nanoparticles are mainly composed of Ru and S, confirming the presence of Ru2S3 nanoparticles in cubic phase. The inner morphology of nanoparticles was obtained by transmission electron microscopy (TEM) and most nanoparticles had narrow particle size distribution characterized by an average diameter of 8.45 nm with a standard deviation of 1.6 nm. The optical band gap (Eg) determined from Tauc plot was found in the range (3.44 to 4.18 eV) values.
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Screening of shark liver extracts for potential antimicrobial properties against selected pathogenic bacterial strains
- Authors: Mrwetyana, Thandolwethu
- Date: 2017
- Subjects: Fishes -- Diseases Pathogenic bacteria
- Language: English
- Type: Thesis , Masters , Microbiology
- Identifier: http://hdl.handle.net/10353/13004 , vital:39431
- Description: The growing problem of antimicrobial resistance prevents the effective treatment of bacterial infections. Traditional antibiotics such as penicillin have been rendered ineffective against most microbial pathogens. This has led to an increased need for the development of new and improved drugs. The marine environment contains a great array of organisms with unique biological properties, but still remains one of our most underutilized biological resources. The aim of this study was to screen different shark liver extracts for antimicrobial properties. After optimizing the extraction methods, the liver extracts (oil and aminosterol) of three different shark species, namely the Dogfish (Squalus acanthias), the Catshark (Scyliorhinus capensis) and the Hammerhead (Sphyrna zygaena) shark, were screened for antimicrobial properties using the Kirby-Bauer disc diffusion method against selected bacterial pathogens (Helicobacter pylori, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus cereus), after which the MIC was determined using the modified broth micro-dilution described by Vollekova et al. (2001). The most active extract was fractionated using thin layer chromatography, and TLC-direct bioautography was used to determine the antimicrobial properties of the fractionated compounds. The Folch et al and the Shinnar et al methods yielded the highest extract volumes for oil and aminosterol consecutively, and the catshark and dogfish aminosterol extract showed greater levels of bioactivity against all selected bacterial pathogens, with S. aureus showing highest susceptibility levels to both extracts. A total of 22 compounds were observed in the developed plates with two compounds (Rf 0.53 and 0.79) showing antimicrobial activity. Certain shark liver extracts possess antimicrobial properties that have the potential to be used in the development of new antimicrobial drugs.
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Screening of shark liver extracts for potential antimicrobial properties against selected pathogenic bacterial strains
- Authors: Mrwetyana, Thandolwethu
- Date: 2017
- Subjects: Fishes -- Diseases Pathogenic bacteria Antibiotics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12982 , vital:39413
- Description: The growing problem of antimicrobial resistance prevents the effective treatment of bacterial infections. Traditional antibiotics such as penicillin have been rendered ineffective against most microbial pathogens. This has led to an increased need for the development of new and improved drugs. The marine environment contains a great array of organisms with unique biological properties, but still remains one of our most underutilized biological resources. The aim of this study was to screen different shark liver extracts for antimicrobial properties. After optimizing the extraction methods, the liver extracts (oil and aminosterol) of three different shark species, namely the Dogfish (Squalus acanthias), the Catshark (Scyliorhinus capensis) and the Hammerhead (Sphyrna zygaena) shark, were screened for antimicrobial properties using the Kirby-Bauer disc diffusion method against selected bacterial pathogens (Helicobacter pylori, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus cereus), after which the MIC was determined using the modified broth micro-dilution described by Vollekova et al. (2001). The most active extract was fractionated using thin layer chromatography, and TLC-direct bioautography was used to determine the antimicrobial properties of the fractionated compounds. The Folch et al and the Shinnar et al methods yielded the highest extract volumes for oil and aminosterol consecutively, and the catshark and dogfish aminosterol extract showed greater levels of bioactivity against all selected bacterial pathogens, with S. aureus showing highest susceptibility levels to both extracts. A total of 22 compounds were observed in the developed plates with two compounds (Rf 0.53 and 0.79) showing antimicrobial activity. Certain shark liver extracts possess antimicrobial properties that have the potential to be used in the development of new antimicrobial drugs.
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Seasonal variations in tick loads, coat characteristics, temperature-humidity index and blood metabolite profiles of extensively raised Boran cows
- Authors: Ntilini, Wonga John
- Date: 2017
- Subjects: Boran cattle -- South Africa Ticks -- South Africa
- Language: English
- Type: Thesis , Masters , MAgric
- Identifier: http://hdl.handle.net/10353/13471 , vital:39672
- Description: This study sought to determine the seasonal variations in tick loads, coat characteristics, temperature-humidity index and blood metabolite profiles of Boran cows reared in arid rangelands of South Africa. A total of 20 Boran cows of different age groups were used in this study. Tick counts, hair length, coat score, average temperature and relative humidity readings were measured twice (beginning and end) in each season (post-rainy, cold-dry, hot-dry, hot-wet). Blood samples were taken seasonally (beginning and end of the season) for the analysis of creatine kinase (CK) activity and haematological parameters (HP). Ticks were observed and counted from different anatomical sites, namely anterior (neck, head, ears, and around eyes), ventral (belly, udder, and limbs) and posterior (back and under the tail). The tick species observed from the Boran cows were Rhipicephalus evertsi evertsi (34.58percent), Amblyomma hebreaum (43.35percent), Rhipicephalus simus (4.48percent) and Rhipicephalus (Boophilus) decoloratus (17.59percent). Significant differences were observed in tick burdens at various anatomical sites, with posterior position having the highest tick loads during the post-rainy, cold-dry and hot-dry season. While the ventral position recorded the highest tick loads during the hot-wet season. It was also observed that the cattle had significantly long hair lengths during the cold-dry season. Furthermore, coat score and hair length were observed to be negatively (P<0.05) correlated with tick counts, while coat scores were positively (P<0.05) correlated with hair length. Significant differences were observed in CK activity across season, with higher levels during the hot-dry and hot-wet seasons compared to the post-rainy and cold-dry seasons. Boran cows were exposed to a mild stress condition during the hot-dry and hot-wet season when the THI values were high (>70). Seasonal variations had an effect (P<0.05) on some HP (HB, HCT, MCV, MCH, EOS, and BAS). Neutrophils (-0.267) and basophils (0.268) were significantly correlated with THI. In conclusion, the Boran cows were more susceptible to tick loads during the hot seasons. Likewise, the levels of creatine kinase activity and temperature-humidity index were high during the hot-dry and hot-wet season. Therefore, seasonal variations had an effect on tick loads, coat characteristics, temperature-humidity index and blood metabolite profiles of extensively raised Boran cows.
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Sedimentary, geochemical and geophysical study of the Ecca group, Karoo supergroup and its hydrocarbon potential in the Eastern Cape Province, South Africa
- Authors: Baiyegunhi, Christopher
- Date: 2017
- Subjects: Sediments (Geology) -- South Africa -- Eastern Cape Sedimentology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/4881 , vital:28658
- Description: The Ecca Group of Karoo Supergroup is a sedimentary rock sequence that deposited between the Late Carboniferous (Dwyka Group) and the Late Permian-Middle Triassic (Beaufort Group). The Ecca Group investigated in this study is situated in the Eastern Cape Province of South Africa and it comprises mainly of shales, mudstones, siltstones and sandstones. The Ecca Group sequence contains considerable carbon content and suitable thickness to make it an ideal target for shale gas exploration. Previous studies put more emphasis on the geology and stratigraphy of the Ecca Group, this study revised the stratigraphy, and put new insight on the petrography, depositional processes, sedimentary facies, provenance, paleoweathering, tectonic setting, subsidence rates and history, electrical resistivity, source rock characteristics and diagenesis of the potentially feasible sandstone and mudrock reservoir rocks of the Ecca Group. Based on the lithological features, sedimentary structures and facies characteristics, the stratigraphy of the Prince Albert, Whitehill, Collingham and Fort Brown Formations of the Ecca Group is now subdivided into two informal members each, i.e. Lower Member and Upper Member. Furthermore, the Ripon Formation is now subdivided into three informal members. Each member has been asigned a lithological name. The grain size parameters show that most of the Ecca Group sandstones are very fine to fine grained, poorly to moderately well sorted, mostly near-symmetrical and mesokurtic in grain-size distribution. The linear discriminant function analysis is dominantly indicative of turbidity current deposits under deep marine environment for Prince Albert, Whitehill and Collingham Formations, shallow marine environment for Ripon Formation, while the Fort Brown Formation is lacustrine-deltaic deposits. Modal composition analysis and petrography studies revealed that the detrital components of the sandstones are dominated by monocrystalline quartz, feldspar and lithic fragments. The sandstones are compositionally and texturally immature and can be classified as feldspathic wacke and lithic wacke. The provenance analysis revealed plutonic and metamorphic terrains as the main source rocks with minor debris derived from recycled sedimentary rocks. The detrital modal compositions of these sandstones are related to back arc to island and continental margin of tectonic setting. Based on the detailed sedimentological analyses of outcrop and borehole data, fourteen lithofacies were identified and seven facies associations (FAs) were recognised. The facies associations are: FA 1: Shale and mudstones intercalated with siltstones, FA 2: Carbonaceous shale, mudstone with subordinate chert and sandstone, FA 3: Mudstones rhythmite with thin bedded mudstone and lenticular siltstone, FA 4: Greyish medium bedded sandstone intercalated with laminated mudstone, FA 5: Dark-grey medium to thick bedded mudstone and siltstone, FA 6: Thin to medium bedded sandstone alternated with thin bedded carbonaceous mudstone, and FA 7: Varved mudstone rhythmite intercalated with siltstone and minor sandstone. Sedimentological characteristics of the identified facies associations indicate four deposition environments, namely, deep marine basin, turbidite, shallow marine and lacustrine environments, which constitute a gradually regression sequence as a result of sea-level dropping and shallowing of the basin during the developmental processes. Geochemical analysis of the Ecca mudrocks and sandstones revealed that the rocks are of quartzose sedimentary provenance, suggesting that they were derived from a cratonic interior or recycled orogen. The petrography and geochemistry of the sandstones indicated that the source areas are composed of plutonic and metamorphic rocks with a minor component from sedimentary rocks. The geochemical diagrams and indices of weathering suggested that the granitic source rocks underwent moderate to high degree of chemical weathering. The tectonic setting discrimination diagrams support passive continental margin setting of the provenance.
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Small-scale farmers' participation in planning and implementation of farmer support programmes in Amahlathi Local Municipality, Eastern Cape Province, South Africa
- Authors: Makunga, Phendulwa Zikhona
- Date: 2017
- Subjects: Agricultural development projects , Farms, Small -- South Africa -- Eastern Cape , Agriculture -- Economic aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6248 , vital:29529
- Description: The democratic government in South Africa has brought about several policies which were initiated for rural development, and one of the government’s strategies was to involve the agricultural sector. Farmer Support Programmes (FSPs) were developed to assist small-scale farmers to become commercial farmers. The study looked at the participation of small scale farmers in the planning and implementation of the FSPs in the Amahlathi Local Municipality. 108 small scale farmers were selected using a non-random purposive probability and twelve farmers’ organisations. Semi-structured questionnaires and semi-structured interviews were used as the data collection tool and method respectively. The data analysis used was a descriptive analysis and a thematic analysis. The results revealed that the farmers have a positive perception towards the support programmes being helpful in their farming needs. The positive perception was especially on the extension and advisory services, dipping and vaccination programme, and the supply and funding of inputs and assets. However, the results revealed that there was no significant difference between gender and the perception of the farmers when a chi square test of association was performed. The results also revealed that the farmers and farmers’ organisations were not involved in the planning of the programmes by the government. It is therefore recommended that for the success of the FSP and for economic growth in the rural areas, the government has to avoid using a top-down approach when developing these programmes, and instead consult the farmers and the farmers’ organisations to know the specific needs of the farmers in their farming practices.
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Smallholder farmer's climate change knowledge in Ngqushwa Local Municipality, Eastern Cape : implications on coping and adaptation
- Authors: Shoko, Witness Alvis
- Date: 2017
- Subjects: Climatic changes -- South Africa -- Eastern Cape Farms, Small -- South Africa -- Eastern Cape Sustainable agriculture
- Language: English
- Type: Thesis , Masters , MSoc
- Identifier: http://hdl.handle.net/10353/6480 , vital:29744
- Description: Lack of knowledge about climate change poses a greater risk to human development in general. This study emerges from the premise that agriculture, and more specifically smallholder farmers, are the most affected by climate variability due to the type of assets they hold. Among other factors, climate change can directly and adversely impact the ability of smallholder farmers to sustain their livelihoods. Taking into consideration spatial differences across Ngqushwa Local Municipality, smallholder farmers in different areas have to understand the constraints they face that emanate from climate change. The study aimed to explore the knowledge that smallholder farmers in Ngqushwa local municipality have on climate change, strategies they utilise to cope and minimise the detrimental effects of climate change. The study also focused on climate change information sources namely, meteorological and Indigenous Knowledge (IK) that smallholder farmers have at their disposal for coping and adaptation to climate change. Furthermore, the study analyses comprehensiveness and usefulness of information that the resource-poor farmers possess. The findings of this study show that smallholder farmers in Ngqushwa local municipality access climate change information through televisions, newspapers and listening to the radio. Their knowledge of the behaviour of birds, moon, wind, and insects is also an important source of forecasting weather patterns. Recommendations from this study include the following: enhancing and widening the sources of climate change information, education encompassing the nature of climate change, networking of smallholder farmers, linking meteorological and indigenous knowledge and supplementing natural water supply.
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Socio-economic benefits of agricultural projects to surrounding communities: the case of Qamata Irrigation Scheme in the Eastern Cape, South Africa
- Authors: Masela, Zandile
- Date: 2017
- Subjects: Agricultural development projects -- South Africa -- Eastern Cape , Agriculture -- Economic aspects -- South Africa -- Eastern Cape , Irrigation farming -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4716 , vital:28501
- Description: The Qamata Irrigation Scheme (QIS) is one of the largest irrigation schemes in South Africa. Despite substantial state investment, community members have only derived limited benefits from the scheme, leading the government efforts to revitalize the scheme. Many studies have been conducted about QIS but none of them have analyzed the effects of the QIS on the surrounding communities. This study investigated the socio-economic benefits of QIS to surrounding communities. For the purposes of this study, the units of analysis were the surrounding household members, questionnaires were used to collect data. Probabilistic sampling of random sampling method was used to select the villages; respondents’ were availability selected with sample size of 197 households. Quantitative and qualitative data were collected from the participants. To analyse data, descriptive statistics and multinomial logit regression model were used. The study found out that female-headed households constitute 63.45 percent compared to male-headed households at 36.55 percent. The average age of the households in the villages that are within the radius of 10km is 58 years, while it is 59 years in villages that are beyond the 10km radius. In villages within the radius of 10km, 86.08 percent of respondents are unemployed, 5.70 percent are employed at the scheme and 8.23 percent are self-employed. In villages beyond 10km, 84.62 percent of respondents are unemployed, 5.13 percent are employed at the scheme and 10.26 percent are self-employed. In both villages, 71 percent of respondents reported that that they do not get feed supply from the scheme while 29 percent of respondents reported that they get feed supply from the scheme. From the overall distribution of villages within and beyond the radius of 10km, 80 percent of respondents reported that they do not get job opportunities from the QIS while 20 percent of respondents reported that they get job opportunities from the QIS. The study shows that 53 percent of respondents from villages within the radius of 10km are low-benefitting, 33 percent of respondents are intermediate-benefitting and 14 percent of respondents are high-benefitting from the scheme, while in villages beyond the radius of 10km, 97 percent of respondents are low-benefitting, 3 percent of respondents are intermediate-benefitting and none of the respondents is high-benefitting from the scheme. Furthermore, the study, through the multinomial logit regression model, shows that gender for intermediate benefitting has a negative coefficient (-1.70) and shows a significance of 10 percent On the other hand, gender for high benefitting has a positive coefficient (2.57) and shows a significance of 1 percent. Distance from the scheme has a negative coefficient (-3.08) and shows a significance of 1 percent. Access to farmland has a positive coefficient (2.33) and shows a significance of 10 percent. The study recommends that surrounding communities should own home gardens so that they can grow fresh produce and create job opportunities. The surrounding communities are also encouraged to own more farmlands or produce their own crops so they can also learn from the skills of the scheme.
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Spatial and seasonal distribution of selected persistent organic pollutants and phenolic derivatives along the course of the Buffalo River in the Eastern Cape Province of South Africa
- Authors: Yahaya, Abdulrazaq
- Date: 2017
- Subjects: Organic water pollutants Water -- Purification -- Organic compounds removal
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/5939 , vital:29448
- Description:
Persistent organic pollutants (POPs) fall under a group of synthetic chemicals known for their persistence in environmental matrices such as soil and water, and are used in industrial, domestic and agricultural applications. Because of their volatility and lipophilicity, POPs can be transported far away from their point sources and bio-accumulate in food and in fatty tissues of humans and animals. In view of their toxicity and carcinogenicity some organic pollutants such as polychlorinated biphenyl (PCBs), organochlorine pesticides (OCPs) and phenolic derivatives (chlorophenol and nitrophenol) have been classified by United State Environmental Protection Agency (USEPA) and World Health Organization (WHO) as priority pollutants. The present work evaluated the distribution patterns of 19 polychlorinated biphenyls congeners, 17 organochlorine pesticides and selected phenolic derivatives (USEPA 11-priority pollutants) in the Buffalo River, in the Eastern Cape Province, South Africa between December 2015 and May 2016. The Liquid-liquid extraction technique was used for PCBs, OCPs and phenolic derivatives in the river water samples. Silica gel and florisil clean up were carried out for PCBs and OCPs samples respectively and analyzed with gas chromatography electron capture detector (GC/ECD). Phenolic compounds were derivatized and analyzed by gas chromatography mass spectrometer (GC/MS). Limits of detection (LOD), limit of quantitation (LOQ) and relative standard deviation (RSD) for the PCBs were 10 to 330 ng/L, 20 to 1,060 ng/L and 1.18 to 14.1 percent respectively. The LOD, LOQ and RSD for the OCPs were from 20 - 60 ng/L, 110 - 530 ng/L and 0.02 - 0.06 percent, while the corresponding values for the phenolic derivatives were 10 to 70 ng/L, 33 to 222 ng/L and 1.99 - 10.86 percent. In summer, the concentrations of PCBs, OCPs and phenolic derivatives ranged from
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Species composition and seasonal population dynamics of free-living and engorged cattle ticks in three agro-ecological zones of the Eastern Cape Province, South Africa
- Authors: Yawa, Mandla
- Date: 2017
- Subjects: Ticks Boophilus microplus
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/9067 , vital:34224
- Description: This study was conducted to determine species composition and seasonal population dynamics of free-living and engorged cattle ticks in three agro-ecological zones (Bedford dry grassland, Kowie thicket and Bisho thornveld) of the Eastern Cape Province, South Africa. The occurrence of ticks on cattle was studied monthly from April 2016 and March 2017. Tick collections were performed on 360 selected cattle in each agro-ecological zones. During tick collections, 10 randomly selected cattle were sampled at each locality and more attention was given to African blue tick and the presence of Asian blue tick. A half body tick collection was performed from cattle and visible ticks were collected by means of fine-forceps after the animals had been restrained. Body regions that were examined includes the ear, head, neck, chest, abdomen, flank, front and hind leg and feet, tail, and peri-anal region. At each locality, six replicate drags of 100 m, approximately 50 m apart, were performed to collect ticks from vegetation. All ticks collected per cattle and from vegetation were stored in labelled sample tubes containing 70percent ethanol, subsequently counted and identified to genus and species level using a standard stereomicroscope. A total of 31425 ticks belonging to ten species were collected during the study. Rhipicephalus (Boophilus) decoloratus, was the most observed tick species (32.50percent), all other ticks like R. evertsi evertsi (18.84percent), R. appendiculatus (17.26percent), A. hebraeum (16.27percent), R. simus (7.69percent) were also commonly collected. Ixodes pilosus (3.84percent), H. rufipes (3.46percent), R. follis (0.08percent) together with Haemaphysalis silacea (0.02percent) were sporadic infestation. Haemaphysalis elliptica (0.04percent) was only found on the vegetation. No H. rufipes was collected in the thicket vegetation. Agro-ecological zones differ significantly (P<0.05) in tick species and distribution. Significantly more R. (B.) decoloratus were collected in thicket during summer compared to thornveld and dry grassland regions (P<0.05). Free-living ticks were widely distributed across different seasons but with of R. (B.) decoloratus larvae were significantly higher (P<0.05) in thornveld region during the spring season. In conclusion, agro-ecological differences and seasonal variations had an influence on ticks abundance and distribution. From this study, it is of interest to note the absence of R. (B.) microplus, whose trend to invade new areas previously colonised by R. (B.) decoloratus has been observed in Africa. In conclusion, agro-ecological differences and seasonal variations had an influence on ticks abundance and distribution. The aforementioned absence of R. (B.) microplus in this study highlights the importance of further research as this tick invades new areas previously colonised by R. (B.) decoloratus in the continent.
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Statistical analysis and modelling of malaria relapse risk factors using Cox Proportional Hazards model approach : a case study of material data collected from Democratic Republic of Congo
- Authors: Mutambayi, Ruffin Mpiana
- Date: 2017
- Subjects: Malaria -- Congo (Democratic Republic) -- Mathematical models Statistics -- Congo (Democratic Republic) -- Econometric models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15001 , vital:40110
- Description: The field of survival analysis has experienced tremendous growth during the latter half of the 20th century. The objective of this study was to model the relapsing time of uncomplicated falciparum malaria using biographical, sanitation, environmental and preventive information as covariate risk factors. The methodological developments of survival analysis that have had the most profound impact are the Kaplan-Meier method for estimating the survival function, the log-rank test for comparing the equality of two or more survival distributions, and the Cox proportional hazards (PH) model for examining the covariate effects on the hazard function. This thesis presents basic concepts, nonparametric methods (the Kaplan-Meier method and the log-rank test), semi parametric methods (the Cox PH model, and Cox model with time-dependent covariates) and parametric methods (Parametric PH model and the AFT model) for analysing survival data. An improved method was applied to randomized uncomplicated falciparum malaria patients to investigate the risk factors related to the relapsing time in RD Congo. Firstly, the Cox PH model , inf 1 0 ( ) ( )exp 1.91613 0.49633 0.81466 dump spr t X h h t X X X where is the instantaneous risk of experiencing the event at time , without the influence of any covariate was found to better fit the data, as confirmed by the results of the global test that present reasonable and significant results: (Likelihood Ratio: 18.2264 with p-value < 0.0004; Score: 17.6569 with p-value < 0.0005 and Wald: 19.3975 with p<0.0002). Hence from the model above, it can be noticed that ‘dumping site’ (p-value <0.0106; 95percent HR C.I: 1.545, 29.451), ‘spray used’ (p-value < 0. 0.0220; 95percent C.I: 0.391, 0.915), and ‘information related to source of malaria’ (p-value < 0. 0.0012; 95percent C.I: 1.380, 3.725), have a significant impact on the relapsing time of the patients under investigation. It should be noted that many 0() h tt other important covariates such as “usage of mosquito nets” were excluded because of the non-proportionality of the hazards. Secondly, the improvement concept was applied to the Cox model as proposed, and the improved model was as follows: h h t t X t X t X t X t X t X t X t r dump_inf1 spr_inf1 Where h0 (t) is the instantaneous risk of experiencing the event at time t , without the influence of any covariate. The model was found to better fit the data than the standard model — as confirmed by the results from the convergence criterion comparison, where the AIC value of the improved model (754.460) was lower than that of the standard model (767.428). Moreover, the improved model was found to be adequate as the results from the global null hypothesis were significant: (Likelihood Ratio: p-value is 0.0001; Score: p-value is 0.0001; Wald: p-value is 0.0001) and the goodness-of-fit test was confirmed by the plotting of Coxresiduals where the 45 degrees’ line confirmed the results. In conclusion, it was found that the covariates ‘pit’ (p-value is 0.0009; 95percent HR C.I: 11.4133, 1.243e+04), ‘tdwel_spr’ (pvalue = 0.0257; 95percent HR C.I: 1.0016, 1.030e+00), ‘tdwel_inf1 (p-value = 0.0122; 95percent HR C.I: 0.9691, 9.964e-01), ‘maint_dump’ (p-value is 0.0005; 95percent HR C.I: 1.0239, 1.087e+00),‘maint_pit’ (p-value is 0.0007; 95percent HR C.I: 0.9179, 9.774e-01), ‘dump_spr’ (p-value is 0.0027; 95percent HR C.I: 0.9308, 9.853e-01), ‘dump_inf1’ (p-value <0.0001; 95percent HR C.I: 0.9849, 9.947e-01) and ‘spr_inf1’ (p-value is 0.0005; 95percent HR C.I: 1.0119, 1.043e+00) affected the time to relapse from uncomplicated falciparum malaria.
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Stem cutting propagation protocol for rose-scented geranium (Pelargonium graveolens)
- Authors: Matafeni, Ntombekhaya
- Date: 2017
- Subjects: Plant propagation Pelargoniums Plant cuttings
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/9832 , vital:35060
- Description: Rose-scented geranium (Pelargonium graveolens), is a high value essential oil plant that is used in the perfumery, cosmetic, aromatherapy and food flavouring industries. The increasing demand for this plant, due to its economic importance necessitates the development of an efficient propagation protocol for quality seedling and its maximum production. The present study therefore, sought to develop effective stem cutting propagation protocol which could facilitate multiplication of rose-scented geranium stem cuttings. Three separate experiments were undertaken to determine factors influencing effective propagation of rose-scented geranium. These factors were: rooting media, rooting hormone, cutting length and wound healing period on rooting and development of rose-scented geranium stem cuttings. The cuttings were assessed based on root number, length and fresh mass, plant height, leaf number, and stem circumference. In terms of root measurements, the growing media were washed out from the root system of plantlets, their roots were separated from stem before data was recorded which comprised of root number, length and root fresh mass. Root holding ability (RHA) on rooting medium was determined by visual observation and rated on a 1-5 scale where 1 = very loose, not acceptable; 2 = loose, not acceptable; 3 = medium, marginally acceptable; 4 = tight, acceptable; 5 = very tight, acceptable. The experiments were carried out at Essential Amatole Nursery, at the University of Fort Hare Research Farm, Alice Campus (located at 320 47ʹ3ʺS, 260 50ʹ43ʺ E, with an altitude of 519 m.a.s.l). All the experiments were carried out under mist conditions on bottom-heated beds in a greenhouse (with polycarbonate roofing of about 40percent shading effect) for the first three weeks after sticking the cuttings to the growing medium to facilitate root induction in relatively high temperature and relative humidity. Thereafter, the plantlets were grown in a shade house with 70percent light penetration until the termination of the experiment. To optimize the technology for the propagation of this plant the present experiment was designed with the objective to determine the efficient growing medium and proper rooting hormone for successful rooting and development of quality seedlings of rose-scented geranium. The experiment was set up in a complete randomized design (CRD) and was replicated three times with two factors 7×4, seven different growing media i.e. (1) Mixture growing medium which serves as control (pine bark 8 bags + sand 2 bags + lime 4kg + coconut 10 blocks + talborne 6.25 kg + bone meal 2 kg); (2) River sand only; (3) Pine bark; (4) Hygrotex (commercial rooting media); (5) Pine bark + river sand ( at1:1 ratio on volume basis); (6) Pine bark + hygrotex (at 1:1, ratio on volume basis), and; (7) Pine bark + river sand + hygrotex ( at 1:1:1 ratio on volume basis) and four different IBA hormone levels (auxins, types of IBA) applied as treatment were (1) Dynaroot (1 – 1g/kg), (2) Dynaroot (2- 3g/kg), (3) Dynaroot (3-8g/kg) and (4) Control (untreated with hormone). Hygrotex was identified as the best growth media for quicker regeneration giving the highest root number, length and fresh mass. While, hygrotex + pine bark (v/v 1:1) was efficient in producing more leaves, stem circumference and other aerial parameters. Dynaroot 3 was identified as the best rooting enhancer with maximum root number, length, fresh weight and plant height. Both Dynaroot 3 and Dynaroot 2 did not have major differences on giving highest leaf number. Control (untreated with hormone) was consistent in giving the greatest stem circumference than any other treatment. To maximize stem circumference, a combination of control (untreated with hormone) and hygrotex + pine bark (v/v 1:1) was identified as the best treatment. Based on the investigation for maximum production and quality seedlings of rose-scented geranium, hygrotex and Dynaroot 3 were identified as the best combination for successful rooting. The ideal cutting stem length, rooting hormone and growing medium for quality seedlings of rose-scented geranium were also investigated. The experimental lay out was in randomized complete design (RCD) with a 4 × 4 × 2 factorial treatment combination. Treatments used were, four different cutting lengths viz. 10, 12, 14 and 16 cm long; four different concentrations of IBA rooting hormone (Dynaroot 1, 2, 3 (powder form) and distilled water (control) and two types of growing medium (hygrotex and hygrotex + pine bark v/v 1:1) were used. Stem cuttings of 14 and 16 cm length gave the highest root number of 34, 38 and 35.13, and root length of 3.40 and 3.51cm respectively, with no significance. Cutting length of 10 cm favoured stem circumference (3.1 cm) as compared to other treatments. Whereas, cuttings treated with Dynaroot 3 showed a better root number (33.46 roots), root length (3.54 cm), root fresh mass (0.59 mg), leaf number of (11.08) as well as highest root holding ability (5). However, they showed no significance difference with Dynaroot 2 treated cuttings. In addition, cuttings treated with Control favoured shoot number (3.79) and stem circumference (3.05). Visually, hygrotex was observed to be better substrate though it was not significantly different from hygrotex + pine bark (1:1 v/v) on propagation of rose-scented geranium stem cuttings. Therefore, it is recommended that rose-scented geranium should be propagated through the combination of 14 cm cuttings length and treated with Dynaroot 2 IBA rooting hormone. Both hygrotex and hygrotex + pine bark (1:1 v/v) are the best growing media for root formation and growth of rose-scented geranium, though hygrotex alone is more economical. Wound healing period (WHP) of stem cutting was evaluated using 4 × 4 factorial, cuttings were separated into four groups during the healing duration (intervals of 24 hrs: days 0, 1, 2 and 3). These four groups were further subdivided into four subgroups of rooting hormone viz. Dynaroot 1, 2, 3 of indole-3-butyric acid and control (water). Experiment was laid out in a randomised complete block design (RCBD) with three replicates. The results obtained from the study revealed that rose-scented geranium rooted easily when planted on Day 2 of the wound healing period such that root holding ability was at its highest. While, Day 0 cuttings showed good response for stem circumference and shoot number. The study recommends that rose-scented geranium be propagated using cuttings that have enough time to heal the wound that is, Day 2 cuttings. Dynaroot 3 (IBA hormone concentration) showed good response to rooting and other arial parameters except for stem circumference which was favoured by application of control. Based on the results of the study, it can be concluded that propagation of rose-scented geranium requires a wound healing period of about three days in room temperature and application of IBA hormone before sucking cuttings in growing medium. Instead, of Dynaroot 3 or 2, Dynaroot 1 can also be used because, it is less economical and they all have a similar effect on cuttings that have been healing for three days.
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