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An exploration of decision-making processes and experiences for remitting funds abroad: a case for Malawi Diaspora in the UK
Get PDFThis thesis employs a mixed methods approach to investigate remittance patterns over time and the experiences of Malawian migrants in the UK when sending money abroad. The investigation begins with the motivation factors that drive Malawians to migrate to the United Kingdom, as it is argued that migration patterns influence remittance patterns. Qualitative method was used to delve deeply into the context, perspectives, and experiences of participants and patterns of remittance over time, and then to expand the knowledge with the added benefits of a broader study by quantitative method.
The study has demonstrated that remittance behaviours are complex and an approach that takes a broader view on the determinants and perpetuation of remittances and impact on the senders over time operates on multiple levels simultaneously than through individual theories. I have argued that determinants of remittances, patterns of remittances and impact of remittances on senders are strongly related to the phases in the individual life course that vary with the individual’s migration trajectory.
Malawians, I argue, led ambiguous lives in which they struggled to reconcile their feelings about the impact of remitting on their lives and the positive impact their remittances have on the lives of their relatives. While individuals experienced social and economic mobility upon arrival in the UK, sending remittances to Malawi had a negative impact on their economic, psychological, social, and physical wellbeing, and the small positive effects of remitting did not compensate for these difficulties
Investigating the role of age-related intestinal barrier dysfunction and microbial translocation in driving immunesenescence
Get PDFThe human gut is populated by millions of microorganisms and the intestinal epithelium functions as a dynamic barrier against microbes and the environment. The gut microbiota and its metabolites play a vital role in host functional homeostasis, including immune responses. Advancing age is accompanied by alterations in the gut microbiome composition and metabolite profile. Concurrently, ageing is accompanied by remodelling of the immune system, termed immunesenescence, which exerts negative effects on aged host health. However, the precise impact of microbiome changes on immunity are poorly understudied. This thesis aims to improve our understanding of the intricate relationship between the ageing gut microbiome, intestinal barrier dysfunction and immunesenescence.
In this thesis, we identified associations between intestinal barrier dysfunction and features of thymic involution and accelerated T cell ageing in older adults and confirmed a causal relationship between microbial translocation and thymic ageing using an aged germ-free mice model. Next, we linked the age-related loss of core commensals (Lactobacillus and Bifidobacterium) and reduced bioavailability of immunomodulatory microbial metabolites (short-chain fatty acids and secondary bile acids) with an unhealthy immune system and low influenza vaccine immunogenicity in old age. Lastly, we explored the potential for dietary patterns, such as the Mediterranean diet and multi-vitamin supplementation, as a strategy to promote healthy immune ageing. These novel findings extend our understanding of the consequences of age-related changes in the microbial-immune-metabolic axis and provide evidence for designing future microbiome-targeted interventions that restore immune homeostasis and promote healthy ageing in older adults
The Development of the Catenae on the Gospels
Get PDFThis thesis seeks to explain how the catenae on the Gospels developed up to the ninth century. Updated descriptions are provided here of five catena traditions on the Gospels of Matthew, Luke, and John which are called the Type A Basic Form, Type A Catena Form, Type B Basic Form, Type B Catena Form, and Type Z catenae. This research builds on the new catalogue of catena manuscripts of the Greek New Testament and the editio princeps of the catena in Codex Zacynthius. The Type A and Type B compilations developed in similar patterns of expansion from an anonymous compilation commentary into a more complex catena with attributed scholia. Examining the additional material in the Catena Forms led to the identification of another catena tradition, Type Z, as the source of the attributed scholia. The Basic Forms also share a connection to Type Z. All three compilations used as a source an early exegetical collection which is cited in the Type Z manuscripts with the enigmatic appellation ἐξ ἀνεπιγράφου (from an unattributed source). These findings chart the development of the catenae on the Gospels in new ways, proposing that the manuscripts in Type Z are a distinct catena type which were a project to interpret the Gospels as a collection. The catenae on Mark developed separately from the other catenae on the Gospels even though they are transmitted in the same manuscripts. The recensions of the Commentary on Mark are given updated descriptions and assessed in light of the development of the other catenae on the Gospels. These conclusions have led to a reclassification of the catenae on Luke in the Clavis Patrum Graecorum and provide the foundation for studying catenae as a genre of exegetical writing, the history of biblical interpretation, and the receptions or use of catenae in Byzantine Christianity
Functional and molecular responses of human neutrophils to Fusobacterium nucleatum subspecies
Get PDFFusobacterium nucleatum is a Gram-negative, commensal oral anaerobe, which is a key structural member of dental plaque biofilms. It is also considered an opportunistic pathogen due to its association with periodontitis and systemic extraoral diseases, such as cardiovascular disease and colorectal cancer. Five subspecies are currently recognised: animalis, fusiforme, nucleatum, polymorphum and vincentii. These subspecies, found in the oral cavity and in the extraoral tissues, interact with host innate immune cells, such as neutrophils, which form the first line of defence against microbes. Neutrophils possess a powerful antimicrobial arsenal to remove the invaders, however, excessive responses can cause collateral tissue damage and lead to chronic inflammation. Subspecies-specific neutrophil responses toward F. nucleatum have been reported in the neutrophil-like cell line HL-60, however responses of primary human neutrophils are largely unexplored. Additionally, F. nucleatum typically resides in biofilms, yet, the immunogenicity of biofilm-grown F. nucleatum subspecies has not been addressed to date. Therefore, this doctoral thesis systematically characterised biofilm formation by all subspecies. Subsequently, functional and molecular responses of primary human neutrophils were evaluated when stimulated with planktonic and biofilm-grown F. nucleatum subspecies. Characterisation of single-subspecies biofilm formation included biomass quantification using crystal violet (CV) staining, evaluation of biofilm architecture by scanning electron microscopy (SEM) and assessment of biofilm thickness and stability using confocal laser scanning microscopy (CLSM). Adhesion proteins (adhesins) involved in F. nucleatum biofilm formation were analysed in silico bioinformatically. Formalin-inactivated (planktonic) and live F. nucleatum subspecies (planktonic and biofilm-grown) were used as stimuli to evaluate functional and molecular responses of primary neutrophils isolated from human peripheral blood. Responses of HL-60 cells were evaluated alongside primary neutrophils for comparison
Linear friction welding of Ti-5.3Al-7.7V-0.5Si to Ti-6Al-4V: processing, characterisation and mechanical behaviour
Get PDFIn the development of jet engines, where the reduction of component weight is paramount for improvement in efficiency, the choice of materials and manufacturing processes is critical. Titanium alloys, known for their high specific strength and excellent fatigue resistance, are well-suited materials for engine components in lower-temperature stages. Bladed discs (Blisks), offering a substantial weight reduction over the traditional mechanical assemblies, have become a standard component in jet engines, mainly as fan blisks. Linear friction welding (LFW) emerges as an ideal method for manufacturing blisks by joining blades and discs that are machined separately. LFW is capable of joining dissimilar materials, providing the opportunity to exploit different materials for discs and blades, given their exposure to different thermo-mechanical conditions in service. This research focuses on LFW of dissimilar titanium alloys: Ti-6Al-4V (Ti-64) and Ti-5.3Al-7.7V-0.5Si (Ti-575), with a particular emphasis on optimisation of processing, characterisation of microstructure and crystallographic texture, as well as assessment of mechanical performance. This work aims to enhance the understanding of LFW'd dissimilar joints for aerospace applications, specifically for blisks in the fan and compressor stages of next-generation jet engines.
The microstructure of the parent materials (PMs) and the welded joints was characterised by electron microscopy. Ti-575 parent was found to have superior hardness due to its fine secondary and tertiar
Characterisation of high temperature dwell fatigue in a new generation nickel superalloy
No full textClinical Psychologists’ experiences and perceptions of the climate crisis and activism in the UK, a qualitative study
Get PDFBackground: The threat of climate change to physical and mental health is becoming widely acknowledged. Many clinical psychologists are recognising the relevance of the climate crisis within their professional roles, with the Association for Clinical Psychologists (ACP) and the British Psychological Society (BPS) encouraging psychologists to engage with climate activism. Despite this, there is no literature documenting clinical psychologists’ experiences and perceptions of the climate crisis and climate activism. This qualitative study aims to address this gap in the literature.
Method: Ten participants completed online qualitative surveys. The data were analysed using Reflexive Thematic Analysis (RTA). The study adopted a critical realist epistemology.
Findings: Four key themes were generated through the analysis, namely, Connection, Moving beyond awareness, Power, politics and leadership, Knowledge, dilemmas and dichotomies. Three barriers and two facilitators to climate activism were also identified.
Discussion: The findings are discussed in relation to existing research, and clinical implications are considered. These highlight the importance of embedding teaching on the climate crisis into clinical psychology training, foregrounding social justice and voices from the Global South, and the need for greater leadership and visibility on this topic. The strengths and weaknesses of the present study are discussed, and recommendations for future research are suggested
An analysis of the social aspects of camouflaging in Autism
Get PDFAs a consequence of experiencing significant stigmatisation and discrimination in predominantly neurotypical society, many autistic people engage in impression management strategies. One of those strategies is camouflaging, which encompasses behavioural strategies aimed at minimising the perception of one’s autistic traits. Qualitative research has found that camouflaging may lead to poor mental health and psychological wellbeing in autistic people, but a significant number of quantitative studies provides inconsistent evidence for the link between the two. The study of the relationship between camouflaging and mental health is complicated by the cross-sectional nature of the research body, measurement issues, the unclear directionality of that relationship, and the potential role of the social context and its interaction with one’s behaviour. The purpose of this thesis is to investigate these issues in camouflaging research through exploring potential sources of inconsistency in studies on camouflaging and mental health and the influence of the social context on camouflaging behaviour.
A systematic review and meta-analysis of 23 studies found that camouflaging was significantly associated with adverse mental health outcomes. Study-level effect sizes were not moderated by study quality and sample characteristics, namely the mean age and proportion of female and clinically diagnosed participants. In a qualitative study with 15 autistic adults, social factors such as perceived psychological safety, fit with the interaction partner, and situational demands were found to have an interactive relationship with camouflaging.
Together, the two studies demonstrate the complex nature of camouflaging by highlighting its unclear directionality and potential differential effects across contexts. The findings reiterate the importance of creating autism-inclusive social spaces and provide a foundation for future work on conceptualising and measuring the more complex aspects of camouflaging, such as unconscious camouflaging and its interaction with different social environments
Recognition of DNA junctions by Metallo-Supramolecular Complexes and their cellular delivery by spherical Nucleic Acids
Get PDFThe work presented in this thesis investigates the binding of non-canonical DNA structures by a range of metallo-supramolecular structures. The DNA binding properties of a palladium tetra-stranded helicate is investigated and it’s platinum analogue (PtCyl) is synthesised for the first time. Both the platinum and palladium complexes bind and stabilise DNA 3WJ and 4WJ structures. The platinum complex displays more effective binding to DNA structures due to its enhanced stability in buffered solution. The B-DNA and junction binding properties of this PtCyl and two other known junction binding agents (NiP and AuPill) are compared through several biophysical studies. These studies reveal insights into the structural properties of the complexes that favour junction binding and also the surprisingly high selectivity of PtCyl for DNA 3WJ structures. The binding affinity of the PtCyl and a three stranded dinuclear nickel supramolecular complex (NiP) for a DNA 3WJ structure are quantified through the use of isothermal titration calorimetry. Mass spectrometry is investigated as a possible method for studying the interactions of these supramolecular metal complexes with DNA structures. Spherical nucleic acids (SNAs) are studied as a potential vehicle for the delivery of these supramolecular metal complexes. SNAs are successfully synthesised and loaded with the NiP and PtCyl. The gold-SNA nanoparticles are able to release the metal complexes in the presence of their preferred binding target, DNA junctions. Efforts were made to increase the loading of the metal complexes on the nanoparticles, with limited success. Preliminary cell studies indicate very little toxicity of these systems which is likely due to the low loading of the complexes achieved
Anxiety prevalence following traumatic brain injury and detecting feigned impairment with the Denver Attention test
Get PDFThis thesis consists of four chapters. Chapter one is a meta-analytic review examining the prevalence data for generated anxiety disorder (GAD) and clinically significant cases of anxiety in adults with non-penetrating traumatic brain injury (TBI). The review is an update of a previous meta-analysis published in 2014 and explores the past decade of research in this area. Data from 33 studies and a combined sample of 12,063 participants are reported. The impact of time since injury, assessment method, injury severity, and psychiatric history are each examined. Findings reveal that following TBI, GAD and clinically significant anxiety are almost four and six times respectively, more prevalent than in the general population. These findings underscore the importance of assessing mental health needs following TBI.
Chapter two is an empirical study which explores the utility of a newly developed performance validity measure (PVT) called the Denver attention Test (DAT). A simulator study design is used to examine the DATs ability to discriminate between a group of participants who are instructed to do their best and another who are instructed to feign cognitive impairment. Results find that the DAT is a rapid, easy to administer PVT that provides a robust measure of performance validity. It demonstrates excellent ability to detect feigned cognitive impairment in a simulator sample, though further investigation is needed with clinical groups.
Chapters three and four are press releases for the meta-analytic review and empirical study. This research hopes to bring new insights to the field of neuropsychology
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