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Respiratory viral infections are routinely studied with animal models or in vitro culture which mimic but do not fully recapitulate elements of human immune responses or pathology. Studying events at the respiratory mucosa where infection is established is crucial to further our understanding of immune responses to these infections. In this thesis I evaluated the zebrafish gills as a novel in vivo model to study respiratory immunity. Using transgenic zebrafish, flow cytometry and several microscopy techniques I characterized immune cell composition and function in this tissue. In addition, I assessed the stimulatory effects of pathogen mimetics and derivatives on immune response pathways using RNA analysis. The stimulatory and pathological effects of live viral challenges were also assessed. These experiments highlighted the abundance and diversity of innate and adaptive immune cells in the gills from early to adult developmental stages. Some of these immune cells were capable of antigen-uptake and formed dynamic cell-cell interactions. Aggregates of T and B cells were identified as interbranchial lymphoid tissue which had some similarities but also some architectural differences to mammalian mucosal-associated lymphoid tissue. Different responses were stimulated by resiquimod and lipopolysaccharide highlighting these pathogen-related compounds as tools to interrogate immune pathways in the gills. On the other hand, zebrafish had limited responses to human respiratory or fish-endemic viruses and were resistant to pathological infection. These results highlight zebrafish gills as a useful model to investigate several aspects of immune cell function and inflammation in a respiratory mucosal in vivo setting. Further investigation with pathogens is needed to expand the use of this model for infection studies.

Current cognitive-behavioural sexual offender treatment programmes request that offenders recall detailed information regarding cognitions, emotions and behaviour in relation to their offending as a means of addressing issues such as claiming responsibility for the offence, social skills training and relapse prevention. However, it was hypothesised that should this offender group demonstrate overgeneralised autobiographical memory recall the efficacy of these fundamental treatment components would be restricted. Therefore, convicted male sexual offenders against children were recruited in order to investigate autobiographical memory recall, and its association with attributional style and social problem-solving. Twelve offender participants completed the Autobiographical Memory Test (AMT; Williams & Broadbent, 1986), Internal, Personal, and Situational Attributions Questionnaire (IPSAQ; Kinderman & Bentall, 1996a) and the Social Problem-Solving Inventory - Revised (SPSI-R; D'Zurilla, Nezu & Maydeu-Olivares, 1997). Demographic data were collected using a general information questionnaire devised by the researcher and the Beck Depression Inventory (BDI; Beck, Rush, Shaw & Emery, 1979) and the Symptom Checklist - 90 -R (SCL-90-R; Derogatis, 1994) were implemented in order to screen for depression and general psychopathology. Twelve male non-offender control participants were also recruited who matched the offender participants on age and level of intellectual ability based on the Raven's Standard Progressive Matrices (SPM; Raven, 1976). The results indicated that the offender group recalled significantly more overgeneral event memories than the control sample, and that this difference prevailed when depressed mood was controlled for. The offender group was also found to endorse 4 negative problem orientation (NPO) and avoidance style (AS) problem-solving strategies significantly more than the control group, and scored significantly poorer on overall social problem-solving (SPS) ability on the SPSI-R. However, when depressed mood was controlled for only a non-significant trend remained suggesting that the offender group implemented avoidance strategies more than the controls. Although, no significant group differences were found for attributional style, the data did highlight greater external attribution for positive than negative events suggestive of a selfblaming cognitive bias in the offender group, which is not consistent with the sexual offence literature. It is postulated that overgeneralised autobiographical memory recall in the offender group is associated with the use of a cognitive style implemented during development in order to defend against negative affect as a result of deviant sexual interests and in some instances a history of childhood sexual abuse (CSA). It is also proposed that a tendency towards avoidance is associated with and exacerbates overgeneral memory recall.

The concepts of “smart mobility” and “vehicle automation” have recently emerged with the aim of eliminating traffic crashes caused by driver error such as distraction, recklessness, speeding, alcohol/drugs-impaired driving, and fatigue, by minimizing or completely removing the human from the driving task. However, the uncertainty about the safety benefits of fully automated vehicles (AVs), especially in the short term, as well as the long-expected transition period before they become widespread on roadways makes it crucial to investigate their potential impact on traffic performance. Therefore the main objective of this research was to use a microsimulation-based method to assess the potential delay and safety impacts of AVs in a mixed autonomy setting where both human-driven and fully automated vehicles operate in the same traffic stream, at a busy signalized intersection with permitted left turns and right turns on red. PTV VISSIM was used to develop the simulation environment comprising of 13 simulation cases, with 4 traffic composition scenarios and 5 different AV market penetration rates (0%, 25%, 50%, 75%, and 100%). The Surrogate Safety Assessment Model (SSAM) was employed to conduct a thorough safety analysis of the diverse scenarios, through the utilization of PET and TTC as surrogate safety measures. 3 TTC approaches were then considered by varying the TTC threshold values to determine the number potential traffic conflicts. The results indicate that at 25% AV MPR, the average intersection delay could be reduced by 25% and as AVs reach 100% MPR, this reduction could go up to 60%. In terms of traffic safety, the total number of conflicts generated decreased as AV MPR increased, with potential safety benefits ranging from 11% to 81% as the AV percentage increased from 25% to 100%. The advanced capabilities of AVs were clearly highlighted in the analysis of rear-end conflicts, where incidents involving human-driven vehicles colliding with autonomous vehicles (HV-AV) were much more frequent than those involving AVs colliding with HVs (AV-HV) across all types of AVs. Comparing the 3 TTC approaches with each other shows an overall reduction in conflicts for lower TTC threshold values. A two-level statistical test performed revealed that at 25%, 75 & 100 % MPR, there is a significant difference going from basic to intermediate AVs but not from intermediate to advanced AVs.

Home based care is one important health care strategy to provide health care services to chronically ill individuals in households away from health facilities. In the advent of the HIV/AIDS epidemic, there are an increased number of individuals affected and infected. The chronicity of the disease has exerted different form of pressure on those who may find themselves caring for the infected. This interpretive phenomelogical study was conducted in Zambia. The study explored and described how family carers reconstructed their lived care life experiences as they dealt with them, how they coped or didn't cope with care demands. Data was generated, transcribed and translated over a period of 10 months through 16 in-depth interviews with family carers, and 10 focus group discussions (3 with Key Informants and 7 with family carers). Data was analysed using thematic analysis and NVIVO software was used to create models. The study adapted the salutogenic model and symbolic interactionism to describe the lived experiences of family carers in HBC situations. The study findings show that family members especially women and/or girls were key in the provision of care in households. However, there may be situations where men also became involved in care work. Family carers constructed their care lives based on the confirmed identity of being caregivers whose desire to provide care was mostly based on meaningfulness attached to the relationship with the patient, and derived satisfaction from their input to the health of their patient. There were strong interlinkages between comprehensibility, manageability and meaningfulness (the Generalised Resistance Resources components of the salutogenic model) and emotional closeness in the care situations. In the construction of their lived care experiences, one common coping factor was Godly devotions with strong relationship with spirituality and religion which was linked to the three aspects of the GRR. Other coping factors such as "training", "love for the patient", "piece work" and "patient is a relative" were mostly linked to comprehensibility. Caregivers strived to find knowledge and skills to deal with any challenging care situation, and most caregivers lacked these attributes. However, their perceived identity as a caregiver generated and strengthened their desire to do something for the patient. In addition, self-identity as caregivers and the sense of filial piety encouraged the motivation to go on despite difficulties faced. Caregivers constructed their care lives based on the meaning the care input meant for the patient, and to those they were ii confirming their identity to as caregivers. Hence meaningfulness was one key component that was observed to be high amongst all as this resource provided them with the desire to go on caring, there were weakness found in comprehensibility and manageability. There were weaknesses felt in comprehensibility as a resource to facilitate cognitive elements of care. Caregivers felt that care work was ordered but not predictable as situations and conditions related to the patient and households were dynamic. They did not have easy access to resources to support their work. Those who devised any coping mechanisms did so within the boundaries of "suffering" with care work. Their care life was viewed as difficult and subjected them to different situations in the health of the patients which they could not provide. Family carers found coping with care giving not easy to attain. Family carers made cognisant of the care environment, which did not make available supportive structures to enhance coping with care work. As result of the breakdown of family structures especially the extended families from HIV/AIDS, most family carers experienced an environment that was not conducive to provision of care for chronically ill patients. The findings challenge the implementation of HBC as a strategy to help chronically ill PLWHA as health care service at the household. The study suggests that the country‟s recognition of HBC strategy through different policy pronouncement will require concerted efforts to ensure that those providing care in households are provided with effective and efficient support mechanisms to improve care of patients.