163 research outputs found

    Molecular epidemiology of Salmonella in the broiler industry of Sri Lanka : thesis presented in fulfilment of the requirements for the degree of Doctor of Philosophy in Veterinary Science at Massey University, Palmerston North, New Zealand

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    The increasing occurrence of non-typhoidal Salmonella in poultry is an emerging threat for public health in Sri Lanka, and salmonellosis has incurred massive economic loss for the poultry industry in the country. Thus, the thesis presented encompasses a comprehensive study to understand prevalence and possible risk factors for Salmonella carriage in broiler farms as well as whole-genome sequence-based population structure, phylogenetic relationships and antimicrobial resistance in Salmonella in Sri Lankan poultry. The studies described in this thesis include a cross-sectional survey (i.e., sampling and questionnaire-based study) conducted from July to December 2017 in broiler farms (115) from poultry-dense areas and associated hatcheries (15) as well as an outbreak study (from 2010 to 2018), based on isolates and metadata from poultry salmonellosis outbreaks. After initial identification and PCR confirmation of a total of 164 Salmonella isolates, whole-genome sequencing was performed and antimicrobial resistance profiles of the isolates were determined. Results revealed a Salmonella prevalence of 32.2%, CI 95% [23.6-40.7] in broiler farms and 66.7%, CI 95% [42.8-90.5] in the associated hatcheries. Litter management, rest period between flocks, feed storage, district and farmersā€™ knowledge of sick birds were identified as risk factors for Salmonella carriage in the broiler farms, through multivariate logistic regression modelling. Eighteen different multi-locus sequence types of Salmonella were identified, including nine which were reported for the first time in Sri Lankan poultry. The most common serovars were S. Kentucky ST314 (26.8%, CI 95% [20.0-33.6]) and S. Enteritidis ST11 (19.5%, CI 95% [13.4-25.6]). A high percentage of quinolone resistance manifesting as resistance to nalidixic acid (41.5%, CI 95% [33.9-49.1]) and intermediate resistance to ciprofloxacin (45.1%, CI 95% [37.5-52.7]) and enrofloxacin (35.4%, CI 95% [28.0-42.7]) was found. The findings of this thesis, especially in the absence of previous comprehensive studies, will enable the design of control strategies to strengthen the national Salmonella control programme in Sri Lanka

    Massive Open Online Courses

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    Massive Open Online Courses (MOOCs) are a new addition to the open educational provision. They are offered mainly by prestigious universities on various commercial and non-commercial MOOC platforms allowing anyone who is interested to experience the world class teaching practiced in these universities. MOOCs have attracted wide interest from around the world. However, learner demographics in MOOCs suggest that some demographic groups are underrepresented. At present MOOCs seem to be better serving the continuous professional development sector

    A conceptual framework for learners self-directing their learning in MOOCs: components, enablers and inhibitors

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    The conceptual framework presented in this chapter describes the learning components influencing the learning experiences of adult informal learners engaged in MOOCs offered on the FutureLearn platform. It consists of five learning components: individual characteristics, technology, individual & social learning, organising learning, and context. These five learning components are driven by two enablers or inhibitors of learning: motivation and learning goals. For adult informal learners, motivation is mostly intrinsic, and learning goals are mostly personal. This research investigated the informal learning of 56 adult learners with prior online experience, as they studied various subjects in MOOCs. Literature on MOOCs, mobile and informal learning provides scientific support, in addition to literature clarifying the rationale for self-directed learning as a focus of investigation. The participants of this study voluntarily followed one of three FutureLearn courses that were rolled out for the first time at the end of 2014. Data were collected at three stages through an online survey (pre-course), self-reported learning logs (during the course), and semi-structured one-on-one interviews (post-course). The data were analysed using Charmazā€™s (2014) method for constructing a grounded theory
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