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The importance of social networks amongst refugees resettled through the Community Sponsorship scheme and The Vulnerable Persons Resettlement Scheme
Get PDFThe dramatic increase in the number of displaced people in the last decade, predominantly hosted by low and middle-income countries, has prompted a reassessment of solutions to ensure international protection and shared responsibilities for refugees. In response, resettlement programmes have been developed and expanded worldwide, allowing the transfer of refugees from first asylum countries to third countries. In 2014, the UK launched the Vulnerable Persons Resettlement Scheme (VPRS), aiming to resettle 20,000 refugees from the Syrian conflict. Through the programmes, refugees are supported by local authorities and an assigned caseworker to aid their integration processes. Simultaneously, sponsorship programmes, allowing individuals to sponsor refugee families and support their integration processes, have emerged in nearly twenty countries. In Europe, the UK developed the first Community Sponsorship (CS) scheme in 2016.
Behind the enthusiasm for sponsorship programmes often lies the assumption that sponsored refugees receive better assistance than those resettled by government-led programmes, due to the support provided by volunteers' networks facilitating their integration processes. However, there is a paucity of comparative studies providing evidence supporting this assumption, especially outside Canada, where sponsorship programmes differ significantly from those developed in Europe. Additionally, although the importance of social networks in integration processes is widely recognised, several knowledge gaps exist regarding the formation and development of refugees' social networks and their role in supporting integration processes.
Drawing on migration literature and social network analysis, this study addresses these knowledge gaps by comparing the social networks of refugees resettled through VPRS and CS with a view to understanding how different types of social connections and resources they provide shape integration processes. In addition to distinguishing between types of relationships and resources, this study's conceptual framework also considers individual-level factors, such as refugees' socio-demographic and migration characteristics, as well as contextual-level factors in shaping social networks and integration outcomes and processes.
The findings reveal significant depth and breadth differences between the social networks developed by CS and VPRS refugees, suggesting that through CS, refugees are more likely to develop broader and more diversified social networks compared to VPRS refugees. Differences in the types of resources available through social networks further highlight that sponsored refugees can access more tailored practical and emotional support than VPRS refugees. Utilising the Indicators of Integration framework, the study indicates that these variations in social networks and resources do not always lead to substantial disparities in integration outcomes, particularly in functional aspects, as the presence of a social network is insufficient to overcome structural barriers hindering integration processes. However, the presence of caring relationships providing emotional support among sponsored refugees' social networks underscores the significance of these relationships in integration processes. Specifically, sponsored refugees reported how these relationships enable them to feel more confident and comfortable, develop relationships with the wider community and increase their willingness and ability to reciprocate, positively impacting their integration processes
Mathematical modelling of invasive spread in the heterogeneous landscape
Get PDFInvasive plant species pose a significant threat to biodiversity and the economy, and their management is often resource-intensive and expensive. Evidence suggests that roads can have an important effect on the spread of invasive plant species, although little is known about the underlying mechanisms at play. Further research and the application of mathematical models is required to make control measures more efficient.
In this thesis, we develop a novel mathematical model to analyse the impact of roads on the propagation of invasive plants in both the one-dimensional and two-dimensional spatial domains. An integro-difference equation model is formulated for stage-structured population and incorporates a road sub-domain in the spatial domain. We show that, depending on the definition of the growth function in the model, there are three distinct types of behaviour in front of the road. Roads can act as: (1) a barrier to invasion; (2) a temporary obstacle, leading to the formation of a beachhead; (3) as a corridor for invasion. Small changes in conditions favouring the invasive species can change the case for the road, allowing the invasive species to invade the domain in front of the road where it previously could not. We investigate the propagation regime of the invasive plant species studied at the short-time scale before a travelling wave is established and advances into space at a constant speed. Using this approach, we demonstrate how nonlinear spatio-temporal dynamics arise in a transient regime where the propagation speed depends on the detection threshold population density.
In the two-dimensional spatial domain, a long-distance dispersal kernel is incorporated along the road sub-domain. We show how long-distance dispersal along the road can lead to increased invasion in the domain.
Finally, additional landscape heterogeneities around the edge of the road, the edge effect, are investigated. Leading to an increase or decrease in the population density of the species in the spatial domain around the road
Model-driven unsupervised medical image registration
Get PDFIn this thesis, we study pairwise medical image registration, a process that involves determining the optimal spatial deformation between two medical images. While traditional image registration methods relied on iterative optimization, recent years have witnessed a significant shift towards modern deep data-driven techniques. Within this context, this thesis focuses on unsupervised neural network-based registration approaches, with a primary emphasis on integrating prior knowledge derived from model-based strategies into network architectures to enhance their learning capabilities. More specifically, we address three critical research challenges currently facing the medical image registration community. The first challenge centers on whether deep data-driven registration methods can achieve higher registration accuracy. The second challenge concerns enhancing the data efficiency of deep registration methods. The third challenge involves accelerating the speed of deep registration methods, in terms of both training and inference.
To address the first challenge, we begin by offering a comprehensive guide to constructing a basic deformable registration method based on the U-Net architecture. Alongside this fundamental model, we then introduce three novel variants: Large Kernel U-Net (LKU-Net), which increases the network’s effective receptive field through multiple parallel convolutional layers to capture finer spatial structures from the input data; Cascaded LKU-Net, which stacks multiple base LKU-Nets and thereby effectively manages large deformations; and LKU-Net-Affine, which incorporates multiple fully connected modules to learn transformation-specific parameters, enabling adaptability to parametric rigid and affine registration tasks. These variants empower the U-Net model to address both parametric and deformable registration and effectively capture complex deformations that may present in high-resolution medical image data, such as 3D expansion microscopy images and 3D lung CT images.
To address the second challenge, we introduce VR-Net, a variational registration network that unrolls the mathematical structure of iterative variational optimization through variable splitting and seamlessly integrates it into a deep neural network in a cascading fashion. VR-Net is designed to inherit prior knowledge drawn from model-based solvers, ensuring the preservation of their data efficiency and generalizability while maintaining the fast speeds of learning-based approaches. Extensive experiments conducted on 2D and 3D cardiac MRI datasets demonstrate that VR-Net outperforms both traditional model-based and deep data-driven approaches in terms of registration accuracy while retaining fast inference speed and data efficiency.
To address the third challenge, we present Fourier-Net, a novel approach that predicts a compact, low-dimensional representation of the deformation in the band-limited Fourier space. Within Fourier-Net, we propose a model-driven decoder to effectively reconstruct the full-resolution deformation field from the band-limited coefficients. We then introduce Fourier-Net+, an extension of Fourier-Net, which learns the band-limited deformation field from the band-limited representation of images. Fourier-Net+ further accelerates the registration speed by constraining both the input and output of the network to low-dimensional representations, reducing the need for repeated convolution operations. Fourier-Net and Fourier-Net+ are evaluated on cardiac and brain MRI registration tasks in both 2D and 3D scenarios, demonstrating significant reductions in multiply-addition operations, memory footprint, and CPU runtime
Investigating DNA−polymer conjugates by low-volume aqueous polymerization-induced self-assembly (PISA)
Get PDFOver the past few decades, deoxyribonucleic acid (DNA)-polymer conjugates have been attracting interest as adaptable functional materials in various biorelated applications. However, determining the optimal synthetic conditions of conjugating hydrophilic DNA with hydrophobic polymers still presents a significant challenge and this limitation currently constrains the progress of research in this field. In recent decades, polymerization-induced self-assembly (PISA) has attracted significant attention for constructing nano-objects with various morphologies such as vesicles, worms, and spheres owing to the one-step nature of the process. To date, the most commonly utilized polymerization technique in PISA is reversible-addition fragmentation chain transfer (RAFT) polymerization due to its versatility and broad applicability.1, 2 In RAFTmediated emulsion PISA, a solvophilic macromolecular chain transfer agent (macroCTA) and a solvent-miscible monomer are polymerized to generate solvophobic polymer and create self-assembled nanostructures.3 Thus, PISA could be a potential method for producing amphiphilic DNA-polymer nanostructures. However, the high cost of DNA necessitates the use of minimal reaction volumes in PISA procedures, which remains an
ongoing challenge due to limitations such as oxygen inhibition, low potential reproducibility, and the requirement for special equipment. This Ph.D. project aims to develop reproducible conditions for low-volume PISA reactions in an attempt to utilize a deoxyribonucleic acid macromolecular chain transfer agent (DNA-macroCTA) and 2- hydroxypropyl methacrylate (HPMA) monomer to generate DNA-decorated polymeric nanostructures of various morphologies via PISA for future medical applications.In chapter 2, poly(ethylene glycol) macromolecular chain transfer agent was synthesized, and their corresponding synthetic diblock copolymers with HPMA monomer were prepared via RAFT-mediated photoinitiated PISA. The optimalization of a low-volume system was investigated through physical and chemical strategies to eliminate oxygen
inhibition in low-volume polymerization. Nitrogen glove bag method was applied for curing in an oxygen-free atmosphere for physical strategy while glucose oxidase (GOx) in the presence of glucose, was applied in chemical strategy. Moreover, phase diagram was investigated in the optimal low volume conditions. This optimal low volume condition was applied with the DNA-macroCTA and the identical HPMA monomer in
chapter 3. This chapter was divided into two sections, each focusing on the generation of DNA-PHPMA nanoparticles through different sources of synthesized DNA-macroCTA. The first section utilized DNA-macroCTA received from the Sleiman group, our collaborators while the second section involved DNA-macroCTA synthesized by our group. Additionally, two methods for synthesizing DNA-macroCTA were highlighted, involving both solution-based and solid support approaches. This chapter further explored the impact of salts and hybridization with the DNA-polymer particles. In chapter 4, the combination of PEG-macroCTA and DNA-macroCTA was investigated to facilitate morphological transitions in DNA-decorated particles. Moreover, the utilization of hybridization and hybridization chain reaction (HCR) was explored with the mixture corona of PEG and DNA
The politics of disablement and precarious work in the UK: prefiguring a non-productivist future
No full textThe Politics of Disablement and Precarious Work is a postdisciplinary qualitative research study of disabling capitalism’s social relations, its productivist institution of work, and non-productivist alternatives. The insights developed in this thesis are embedded in the viewpoints and everyday activities of twenty-seven gig economy workers who are subjected to disablement oppression and exploitation in contemporary UK and informed by the UPIAS-inspired social model and post-'68 non-productivist Marxisms. Its contributions are as follows. First, this thesis offers a new theoretical lens called the collective-materialist approach to disablement (with five tenets) through which I demonstrate the benefits of synthesising the UPIAS-inspired social model of disability with post-’68 anti-productivist Marxisms. Second, the relationship between structural disablement oppression and exploitation (on the one hand) and capitalist social relations (on the other) is clarified through a new disability composition thesis. In short, I demonstrate that all people with impairments, who are chronically ill, d/Deaf, neurodivergent, and who experience mental distress are subjected to disablement, regardless of how they self-identify. Third, this thesis highlights participants’ experiences of everyday activities whilst also centring their critiques of productivism and visions for alternative horizons of possibility. Thus, through an analysis of participant interviews and diary entries, I identify six broad spheres of activity, such as waged work, unwaged work for the state and ‘professionals’, navigating the individual model of disability in everyday interpersonal relations, assistance work, subversion work and collective self-activity, and activities conducive to rest. In doing so, this thesis offers an expansive definition of ‘work’ to include activities that are often overlooked in academic literatures. It also highlights the complexity of non-waged work and its relationship to disabling capitalism. I approach the analysis of these activities through the work transfer thesis and argue that transformed conditions and resources are necessary to make space for prefigurative activities that act against-and-beyond disabling capitalism and the wage system. This thesis’ collective-materialist approach to everyday activities’ role in reproducing, reforming, or prefiguring beyond disabling capitalist social relations provides scholars and activists with a perspective that can inform transformative collective action and analysis – a perspective that does not separate capitalism and disablement and that strives for their abolition. Finally, this thesis calls for further explorations of the political economy of rest from non-productivist Marxist perspectives
Global ionospheric model development and utilisation for novel radio systems
Get PDFGlobal ionospheric models have a wide range of uses in addition to developing the understanding and characterisation of the ionosphere. Two examples of these uses are explored within this work, both of which use ionospheric models to predict ionospheric impacts to radio transmissions as they pass through the ionosphere. The first example is the impact of the ionosphere on High Frequency (HF) propagation, namely in the context of a multistatic over the horizon radar (OTHR) simulation. By ray tracing through output from an ionospheric model, the sensitivity of a simulated multistatic OTHR (MOTHR) has been compared to the sensitivity of a simulated, conventional monostatic OTHR configuration. The MOTHR requires a target signal to be detected by the monostatic receiver and at least one bistatic receiver simultaneously. This makes it possible for a target velocity to be determined from a single radar sweep, and makes it easier to distinguish the signal scattered by the target from the signal scattered by illuminated terrain or water waves. The region for which targets could be detected by the MOTHR was very similar to the coverage area for a monostatic OTHR configuration. The monostatic configuration could detect smaller targets than the MOTHR configuration; however, the loss of sensitivity was not severe for most locations, and small targets could still be detected with the MOTHR.
The second example is the impact of the ionosphere on Ultra High Frequency (UHF) propagation, focusing on the impact of ionospheric irregularities on Global Navigation Satellite System (GNSS) transmissions. Transmissions passing through regions with sudden changes in plasma density can result in rapid fluctuations of signal amplitude or phase, referred to as ionospheric scintillation. These sudden changes in plasma density take the form of plasma bubbles at low latitudes, which can considerably degrade GNSS performance in that region. A novel method to forecast the scintillation due to plasma bubbles at low latitudes has been developed. This method is shown to have forecasting skill as good as, or better than, an existing method when using output from the same physics based ionospheric model. Modelled electron densities are used to determine a proxy for vertical plasma drift (PVPD) speeds at the post sunset magnetic equator, which are used as an indicator of whether scintillation will occur. PVPD forecasting using a global ensemble data assimilation ionospheric model is shown to have a significant improvement in forecasting skill compared to PVPD forecasting with the physics based model for a single test case. A methodology to use ensembles of PVPD values to produce probabilistic scintillation forecasts is also discussed.
The accuracy of HF ray tracing and scintillation forecasting within this work are dependent on the quality of the ionospheric specification. Furthermore, excellent ionospheric specification would be crucial for, e.g., coordinate registration in an operational MOTHR. A technique to potentially improve the accuracy of an ensemble data assimilation model of the ionosphere by increasing variability between ensemble members is described. Additional variability between ensemble members can be generated by adding perturbations to lower boundary horizontal wind speeds. It is shown that lower boundary perturbations impact ionospheric conditions at higher altitudes, and can increase the range of modelled ionospheric conditions
The processing of multi-word sequences in first and second language
Get PDFSentence reading not only involves recognising single words but also requires recurrent word sequences to be comprehended together. This thesis investigates the processing of different types of recurrent word sequences during sentence reading in both L1 and L2 speakers. Following a general introduction (Chapter 1) and a theoretical overview (Chapter 2), Chapter 3 followed a phraseological approach to define word combinations and compared the processing of free word combinations (of which all components are used in their literal sense and can be freely substituted, e.g., affect one’s mind), restricted collocations (which have one lexical part that is usually used in a de-lexical or figurative sense and which cannot be freely replaced by a word with a similar semantic meaning, e.g., enter one’s mind), and idioms (which have a conventionalised figurative interpretation, e.g., blow one’s mind). Chapter 3 used a self-paced reading paradigm paired with a stop-making-sense task. L1 speakers read idioms more quickly than free word combinations, while L2 proficiency and the type of word combinations interacted to affect the processing of these word combinations. Chapter 4 used the same experimental paradigm and addressed idiomatic ambiguity by comparing ambiguous idioms (i.e., those that can also interpreted literally, e.g., grey area) to corpus-defined collocations (e.g., vast area) and novel literal expressions (i.e., newly coined word combinations, e.g., rare area), with word-level and phrase-level frequencies strictly matched. L1 speakers read idioms used in their figurative interpretation more quickly than collocations. However, this idiom advantage was not found in L2 speakers. Both L1 and L2 speakers demonstrated meaning dominance and semantic decomposability interacted to resolve the idiomatic ambiguity. Chapter 5 used eye tracking-while-reading to investigate the change in word order in variation collocations by presenting collocations in passive constructions. The change in word order did not eliminate the collocation processing advantage in both L1 and L2 speakers
Optimisation of recombinant protein production in Escherichia coli
Get PDFCurrently, recombinant protein production (RPP) has become more crucial in biopharmaceutical industry and E. coli has become the bacteria of choice. This research has been done to find the optimum condition for RPP using E. coli as the host, and looking for an opportunity to be applied industrially. Green fluorescent protein (GFP) was used as a marker to indicate the production of green fluorescence-proteins, which in this study, was applied to TNFα-GFP. TNFα-GFP is recombinant human TNFα fused to GFP. Two promoter systems were used, namely pORT(T7) plasmid which was inserted into bacterial host BL21(T7) and paraBAD plasmid which was recombined into BL21(A) strain. Arabinose was selected to be used as the inducer in this study to enhance protein production. The parameters investigated in this study were the carbon source and its concentration (glycerol and glucose), the growth temperature (30°C and 37°C), and the concentration of inducer (arabinose). Flow cytometry was routinely used to monitor the quantity and folding state of the TNFα-GFP fusion and cell physiology and viability on a single cell level. Further analysis identified three subpopulations with different fluorescence intensity and productivities, existed in the fermentation medium when using pORT(T7) system. In contrast to paraBAD system which had shown the production of only one single population throughout the fermentation. The optimum condition for RPP measured from this study was the usage of glycerol with the concentration of 0.4% (v/v), incubated at 30°C and arabinose concentration induced was 0.015%. The optimum conditions obtained in these experiments were used for the production of GFP and TNFα-GFP in fed-batch fermentation at 5 L scale. It was concluded that with further adaptation, it is possible to use these optimal conditions to be applied for RP production on an industrial scale. The present study also involved the production of soluble and functional Fumarase B (FumB) enzyme, which was achieved via the use of the restriction-free (RF) cloning method to insert the fumB gene into the pET41c plasmid
The utility of post-treatment FDG PET/CT metrics in the evaluation of head and neck squamous cell carcinoma
Get PDFF-Fluorodeoxyglucose (FDG) positron-emission tomography–computed tomography (PET/CT) imaging is a valuable imaging procedure for tumour staging, restaging, assessing the response to therapy, and in follow-up surveillance among patients diagnosed with head and neck squamous cell carcinoma (HNSCC). While qualitatively assessing PET/CT images has become widely adopted, quantitative analyses have also been introduced to overcome several limitations of visual analysis, enabling a more objective and easier examination of inter- and intra-patient variations. This thesis presents research to investigate the role of FDG PET/CT quantitative metrics in HNSCC. A systematic review and three retrospective studies were undertaken to assess the utility of PET/CT quantitative metrics, including maximum standardised uptake value (SUV) and peak standardised uptake value (SUV) derived at three months following the completion of chemoradiotherapy (CRT) in HNSCC. These studies confirmed the continuous use of the SUV in post-treatment HNSCC and developed further insights regarding the diagnostic and prognostic value of these metrics in this setting. It also provided more insight into the impact of utilising different body size metrics as well as relative metrics in SUV normalisation. Specifically, the systematic review aimed to evaluate the evidence base in the literature on the diagnostic performance and prognostic value of post-treatment FDG PET/CT metrics derived from primary tumour and lymph node sites to discriminate residual disease and predict survival outcomes in patients with HNSCC. This review revealed inconsistent results, requiring further investigation to determine the value of these metrics in the post-treatment setting. The first study aimed to identify the normalisation method that is least sensitive to body size measurements when reporting PET/CT parameters in patients with HNSCC. It was found that variations in body size might have a limited impact on those metrics; therefore, the use of any body size factors appears to be acceptable when analysing post-treatment FGD PET/CT quantitative metrics in HNSCC. The second study sought to assess the diagnostic performance of these quantitative metrics for distinguishing HNSCC residual disease. It was found that all metrics could discriminate between residual disease at the primary and nodal sites at certain thresholds. It was also found that the use of lean body mass (LBM) and body surface area (BSA), as well as a second normalisation of the FDG uptake in the background regions, did not improve their performance. Lastly, the third study investigated the prognostic utility of these quantitative metrics in predicting survival outcomes, as well as the effect of human papilloma virus (HPV) status on their prognostic value. Regardless of HPV status, post-treatment primary tumour and lymph node SUV metrics were found to be significant prognostic factors for predicting three-year progression-free survival (PFS). However, the analysis of five-year overall survival (OS) showed inconclusive findings. Overall, it was concluded that the use of either total body weight, LBM, or BSA in SUV normalisation is suitable for analysing post-treatment scans of HNSCC. This includes the evaluation of quantitative metrics for prognostication and discriminatory ability. Importantly, an increase in post-treatment SUV and SUV values higher than the thresholds presented in this thesis, could potentially signify an augmented likelihood of disease progression. Patients with lesions exhibiting SUV and SUV values that surpass the specified thresholds should thus be closely monitored
Discovering, sharing, creating and hiding Intangible Cultural Heritage throughout the journey of displacement
Get PDFThroughout this thesis, I delve into the intricate interplay between Intangible Cultural Heritage (ICH) and the pervasive challenges of human displacement, aiming to unravel the ways in which ICH is employed, perceived, shared, discovered, hidden and also newly created within displaced communities. This is exemplified by the Rohingya population, who have suffered persecution and large-scale displacements from Burma / Myanmar. The fundamental questions guiding this research are: How is intangible cultural heritage used, viewed or created within displaced communities? And how do humanitarians utilise the intangible cultural heritage of displaced communities?
ICH is a broad term describing the elements of a group's traditional, contemporary and simultaneously living way of life. ICH encompasses a spectrum of traditions and living expressions passed down from ancestors to descendants that are dramatically disrupted during displacement. I propose, that this disruption should be better acknowledged and understood. The research highlights how projecting a lens on ICH firstly reveals a valuable resource that displaced populations use to unify themselves in times of stress and chaos, thus also exposing a valuable resource that humanitarians can tap into in order to ease the suffering of those forced to flee their homelands.
Employing an ethnographic approach, enriched by the narrative depth of 'Yarning,' this research endeavours to document the essence of ICH within a dispersed and displaced population of Rohingya people. Importantly, my research encompasses three Rohingya groups. These groups, each navigating diverse geographies - one in Cox’s Bazar, Bangladesh; another in Karachi, Pakistan; and a third of former refugees resettled in Carlow, Ireland - provide a comprehensive landscape for understanding the dynamics of ICH in displacement.
This thesis contributes to the scholarly discourse on the nexus of ICH in displacement and the Rohingya Muslim experience of identity and unity across borders. It illuminates a mimetic process within the diaspora; from many Muslim arrival stories, displacement emerges as a catalyst for creating one ethnic group of “Rohingya people” as their ICH is discovered, shared, created, and concealed as needed. The significance of ICH unfolds in various dimensions: youth employ Tarana (poetry) in peaceful protests in Bangladesh; fishermen leverage traditional skills to secure an economic niche in Pakistan; women continue traditional fashion and beauty practices even if only behind closed doors and resettled Rohingya utilise ICH from arts and language to sports for successful integration into Irish life. It is also clear that displaced communities suffer without their ability to access their ICH, and I reveal through this study how the agency to wield their ICH is intricately tied to their displacement status, gender dynamics, and acceptance by the host communities
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