Molecular characterization of the tetM gene in clinical isolates of neisseria gonorrhoeae in KwaZulu-Natal, South Africa.

Master of Medical Science in Medical Microbiology and Infection Prevention and Control. University of KwaZulu-Natal, Durban 2017.Abstract available in PDF file

Survival and rooting of selected vegetatively propagated Eucalyptus clones in relation to supplied auxin.

Thesis (M.Sc.)-University of KwaZulu-Natal, Durban 2013.Eucalyptus spp. and hybrids dominate the global plantation forestry industry, and vegetative propagation through cuttings is the preferred method for their commercial use. However, the cuttings of some species and hybrids show recalcitrance to rooting. The first aim of this study was to improve percentage rooting of three clones of E. grandis x E. nitens (Clones 1, 2 and 3) identified by a commercial nursery as having variable rooting abilities. The second was to relate their rooting responses as cuttings to their rooting responses in vitro. Minicuttings (3.5 – 4 cm in length) (hereafter referred to as cuttings) were subjected to commercial nursery propagation practices. Initial results revealed that in the absence of exogenous plant growth regulators (PGRs), soft (juvenile, thin diameter) cuttings survived (87 – 95%) and rooted (29 – 32%) significantly better than hard (mature, thick diameter) ones (62 – 71% survival and 2 – 8% rooting). This validated the use of soft cuttings by the nursery and all subsequent studies were conducted with soft cuttings. The other nursery practice of applying the commercial rooting powder Seradix 2 (3 g kgˉ¹ indole-3-butyric acid [IBA]) adversely affected the survival and subsequent rooting of cuttings of Clones 1 and 2. Ensuing studies investigated: 1) the effect of mode of IBA application (powder vs. liquid); 2) concentrations of Seradix (0, 0.5, 1, 2 and 3 g kgˉ¹ IBA), applied at initial placement of cuttings and two weeks later; and 3) the influence of season on the survival and subsequent rooting of cuttings. Results showed that regardless of the mode of application, IBA significantly reduced percentage survival and rooting in cuttings of Clones 1 and 2. The delayed application of Seradix, two weeks after cuttings were initially set, resulted in a higher percentage survival and rooting than when cuttings were supplied with Seradix at initial placement. Nevertheless, the best survival for Clones 1, 2 and 3 (95%, 99% and 71%, respectively) and rooting (83%, 64% and 47%, respectively) occurred in the absence of Seradix. In addition, the survival and rooting of cuttings were seasonally variable, with particularly low rooting during winter (e.g. for Clone 1, 32%) when compared with summer (e.g. for Clone 1, 83%). Shoots from all the clones were multiplied in vitro, followed by elongation on either of two media (E1= kinetin, α-naphthalene acetic acid [NAA] and IBA; E2 = kinetin and indole-3-acetic acid [IAA]), and then rooting on 0, 0.1 or 1.0 mg 1ˉ¹ IBA. The latter were selected to typify the range of Seradix concentrations used for the cuttings (i.e. no IBA, low and high IBA concentrations). For all three clones, shoots elongated on E1 or E2 displayed high survival (> 80%) but failed to root without IBA in the rooting medium. For Clones 1, 2 and 3 the best in vitro survival (80%, 100% and 100%, respectively) and rooting (40%, 75% and 40%, respectively) occurred when shoots were elongated on E2 and rooted on 0.1 mg 1ˉ¹ IBA. However, 1.0 mg 1ˉ¹ IBA in the rooting medium severely inhibited survival (0 – 50%), irrespective of the clone or the elongation treatment used. Overall, cuttings demonstrated the best survival and rooting in the absence of exogenous IBA, which suggested that sufficient endogenous auxin was present within the shoots for successful root induction. The application of exogenous IBA may have disrupted the cuttings’ endogenous PGR balance resulting in an inhibition of survival and rooting. In vitro shoots required a low concentration of IBA (0.1 mg 1ˉ¹) in order to counteract the antagonistic effect of cytokinins that were supplied during the multiplication and elongation culture stages, and promote rhizogenesis. Essentially, both cuttings and in vitro shoots demonstrated adverse survival and rooting responses when subjected to excessively high IBA concentrations

The effect of omni-distribution systems in managing demand order fulfilment frequencies : an apparel retailer.

Master of Commerce in Management Studies. University of KwaZulu-Natal, Westville 2016.There is no gainsaying that the world of business is characterised by its own set of commercial dynamics. It is within this milieu that the study explores the emerging strategies that characterise the world of commerce with its myriad challenges. In the prevailing commercial environment it is observed that retailers are adopting the omni-channel approach as customers demand a more seamless shopping experience. To remain competitive, distribution networks are challenged to fulfil volatile customer demand from the omni-channel. South African retailers have taken to digital platforms despite barriers to entry in respect of the high cost of broad band and logistics challenges The research objectives of this study aim firstly, to determine the effects of omni-channel retail adoption by retail apparel companies in managing the transformation of the supply chain retail distribution systems; secondly, to examine the extent of relative change in demand to which the distribution systems enhance frequencies of order fulfilment, lead time and cycle time and fill rate; thirdly, to ascertain how the demand-driven omni-distribution systems influence the order fulfilment frequencies in a designated supply chain network; and finally, to establish the perceived contribution of integrated information systems towards information sharing and visibility within the virtual omni-distribution network. Omni-channel retailing is a contemporary topic with very little literature available especially in a South African context. The study employs deductive reasoning with the use of an exploratory case study which adopts a mixed-method approach. The exploratory nature of the study involves the exploration of new phenomena to understand the relationship between variables using interviews and a survey to collect data. Based on a population of 333 managers from 161 stores, 175 assistant store managers, store managers and area managers were surveyed and 13 senior managers and directors from Retailer X and the third party logistics (3PL) were interviewed. The univariate and bivariate methods were used for quantitative analysis while content analysis was used in the qualitative approach. The study reveals that the dispersed landscape and spectrum of cost consciousness to convenience focused customers warrants a customized distribution approach for South African retailers. Using the principles of leagility under the push-pull theory, cost and lead time has to be managed to achieve perfect order fulfilment

Bullying as a Group Process in Childhood:A Longitudinal Social Network Analysis

This study investigates the dynamic interplay between bullying relationships and friendships in a sample of 481 students in 19 elementary school classrooms (age 8-12 years; 50% boys). Based on a relational framework, it is to be expected that friendships would be formed when two children bullied the same person and that children would start to bully the victims of their friends. Similarly, it is to be expected that friendships would be formed when two children were victimized by the same bully and that children would become victimized by the bullies of their friends. Longitudinal bivariate social network analysis supported the first two hypotheses but not the latter two. This study provides evidence for group processes in bullying networks in childhood

The classroom as context for bullying:a social network approach

School bullying is a complex social problem as it involves the characteristics of the perpetrator, the target, and the social context. Recognizing that bullying is relational―who bullies whom, this dissertation uses a social network perspective to study the impact of classroom characteristics on bullying and defending relationships, focusing on classroom structure and stability, and on social relations and social norms. Based on data from Dutch elementary school students, the findings from four different studies show that the examined classroom characteristics have a small impact on the formation of victim-bully as well as victim-defender relationships. No evidence was found that younger children are more likely to be victimized by older classmates, either in multigrade or single-grade classrooms. Bullying relationships were found to develop most easily between children in the same grade, more so in stable classrooms than in classrooms with changing classroom composition, with no clear evidence that newcomers are more at risk of becoming victimized. The finding that bullies tend to become friends and bullies influence their friends to bully, provided further evidence for group processes in bully-victim networks. Examining the relationships between victims and their defenders, it was found that regardless of the number of bullies in the classroom, defending is primarily driven by the direct positive relationship between victim and defender, and to a lesser extent by the shared relationships with other classmates. This dissertation provided more insights in the dynamics of network relationships and school bullying

An examination of Eyal & Hurst’s (2008) framework for promoting retention in resource-poor settings through locally-relevant training: A case study for the University of Guyana Surgical Training Program

Background: Eyal and Hurst proposed that locally relevant medical education can offset the prevalence of physician “brain drain” in resource-poor regions of the world, and presented a framework of the ethical and pragmatic benefits and concerns posed by these initiatives. The present study explored the framework’s utility through a case study of the University of Guyana Diploma in Surgery (UGDS) programMethods: The framework’s utility was evaluated using a case study designthat included review and analysis of documents and semi-structured interviews with graduates, trainees, faculty members, and policy makers associated with the UGDS program. Data were analyzed from constructivist and interpretivist perspectives, and compared against the benefits and concerns described by Eyal and Hurst.Results: The framework is a useful template for capturing the breadth of experience of locally relevant training in the Guyanese setting. However, the results suggest that delineating the framework factors as either beneficial or concerning may constrict its applicability. The case study design also provided specific insights about the UGDS program, which indicate that the Program has promoted the retention of graduates and a sustainable culture of postgraduate medical education in Guyana.Conclusion: It is suggested that the framework be modified so as to represent the benefits and concerns of locally relevant training along a continuum of advantage. These approaches may help us understand retention within a resource-poor country, but also within particularly remote areas and public health care systems generally

Interesting Properties of p-, d-, and f-Block Elements When Coordinated With Dipicolinic Acid and Its Derivatives as Ligands: Their Use as Inorganic Pharmaceuticals

This is a review of the literature concerning the interesting properties of p-, d-, and f-block elements when coordinated with 2,6-pyridinedicarboxylic acid (dipicolinic acid, H2dipic) and its derivatives as ligands, with a focus on their use as inorganic pharmaceuticals. Some of the complexes reported were used as insulin-like, bioimaging contrasting agents, antimicrobial agents, and anticancer agents

Evolution of drug resistance in Mycobacterium tuberculosis: a review on the molecular determinants of resistance and implications for personalized care.

CAPRISA, 2018.Abstract available in pdf

Determining the Community Prevalence of Acute Gastrointestinal Illness and Gaps in Surveillance of Acute Gastroenteritis and Foodborne Diseases in Guyana

Guyana is an English-speaking country in South America and, culturally, it is part of the Caribbean. Objective of this study was to determine the community prevalence and true burden and economic impact of acute gastroenteritis (AGE) and foodborne diseases (FBDs) in Guyana. A cross-sectional population-based survey was conducted in 7 of the 10 regions in Guyana during August and November 2009 to capture the high- and low-AGE season respectively. Overall, 1,254 individual surveys were administered at a response rate of 96.5%. The overall monthly prevalence of self-reported cases of AGE was 7.7% (97 cases) (95% CI 6.3-9.3), and the yearly incidence was 1.0 episodes per person-year. The highest monthly prevalence of AGE was observed in region 4 (8.9%) and in children aged 1-4 year(s) (12.7%). Of the 97 AGE cases, 23% sought medical care; 65% reported spending time at home due to their illness [range 1-20 day(s), mean 2.7 days], of whom 51% required other individuals to look after them while ill. The maximum number of stools per 24 hours ranged from 3 to 9 (mean 4.5), and number of days an individual suffered from AGE ranged from 1 to 21 day(s) (mean 2.7 days). The burden of syndromic AGE cases in the population for 2009 was estimated to be 131,012 cases compared to the reported 30,468 cases (76.7% underreporting), which implies that, for every syndromic case of AGE reported, there were additional 4.3 cases occurring in the community. For every laboratory-confirmed case of FBD/AGE pathogen reported, it was estimated that approximately 2,881 more cases were occurring in the population. Giardia was the most common foodborne pathogen isolated. The minimum estimated annual cost associated with the treatment for AGE was US$ 2,358,233.2, showing that AGE and FBD pose a huge economic burden on Guyana. Underreporting of AGE and foodborne pathogens, stool collection, and laboratory capacity were major gaps, affecting the surveillance of AGE in Guyana