Profiling and prediction of flare in rheumatoid arthritis using clinical, epigenomic, and transcriptomic data

Abstract not currently available

The immunology of the gut-joint axis

Axial spondyloarthritis (axSpA) is a form of arthritis that results in inflammation in the spine and sacroiliac joints. A large portion of people with axSpA have microscopic intestinal inflammation and the prevalence of inflammatory bowel disease (IBD) is markedly higher in this group of people compared to the general population. IBD is an umbrella term for Crohn’s disease (CD) and ulcerative colitis which causes intestinal inflammation as a result of aberrant inflammation towards bacteria within the intestine. Likewise, a substantial proportion of people with IBD have articular inflammation. Although intestinal inflammation in people with axSpA and articular inflammation in people with IBD may be caused by non-specific systemic inflammation, there is evidence to suggest that these diseases have shared immune mechanisms that may drive this inflammation. However, there is a limited number of studies in humans directly comparing the immunology of axSpA and IBD. Understanding whether intestinal inflammation is an integral feature of axSpA or a consequence of systemic inflammation may help inform treatment strategies within the disease. For example, non-steroidal anti-inflammatory drugs (NSAIDs) are a first line intervention for axSpA, however, NSAIDs cause gastrointestinal side effects. In the case that articular inflammation is driven by intestinal changes in this disease, prevention of disease progression and long-term remission may be hindered by the current therapies used to treat axSpA. We therefore aimed to compare changes in the frequencies of various immune cells – including monocytes, DCs, NK cells, NKT-like cells, B cells, CD4+ T cells, and CD8+ T cells – in both people with axSpA and people with CD to identify common changes to circulating immune cells within these two diseases. In addition, we aimed to investigate the expression of activation markers on each of these cell subsets to understand which cells may contribute to inflammation within each disease. To achieve this, we deployed an unbiased, R-based workflow to analyze flow cytometry data. We also quantified the systemic concentrations of various cytokines, including proinflammatory cytokines associated with innate immunity and cytokines associated with type 1, type 2, and type 3 immune responses. Finally, we aimed to determine whether monocytes from people with axSpA exhibit an activated and hyperinflammatory phenotype compared to monocytes from controls by determining phenotypic and functional responses of these cells to LPS stimulation. We found shared changes in the frequencies of nonclassical monocyte, natural killer cell, CD4+ T cell, and CD8+ T cell clusters, alongside shared phenotypic changes on natural killer cells, CD4+ T cells, and CD8+ T cells in both axSpA and CD. In addition, we found shared systemic increases of IL-6, IL-10, IL-17A, IL-17F, IL-22, IL-27, and TNFα, with a shared systemic decrease of IL-4 in both axSpA and CD. While we found decreased CD86+ monocytes in people with axSpA and decreased basal production of IL-10, we did not find any evidence of increased activation or a hyperinflammatory phenotype within monocytes in people with axSpA. This work provides the basis for future research to determine how functional changes in monocytes, natural killer cells, CD4+ T cells, and CD8+T cells may contribute to inflammation in the gut-joint axis

Essays on remittances in conflict-affected and fragile states

This thesis investigates the role of remittances in household welfare and the impact of various shocks on remittance flows in fragile conflict-affected Somalia. The thesis constitutes of three interconnected essays. The first essay analyses how remittances influence key household outcomes, such as asset accumulation, savings behavior, financial inclusion, education and consumption pattern. It utilizes unique survey data from Somalia and propensity score matching techniques are applied to compare households receiving remittances with those that do not, in order to analyze the causal effects of remittances. The results show that remittances (1) have a consistently positive impact on productive assets, such as savings and livestock ownership, as well as on educational attainment for children; (2) enhances financial inclusion and living standards, resulting in higher consumption levels and improvements in both food and non food consumption; (3) benefits both poor and non-poor households, with the most significant impact observed among non-poor recipients; and (4) increase household wealth across both small and large households, although the effect on livestock ownership is less pronounced in large families. The results underscore the important role of remittances in improving key household outcomes in Somalia. This suggests that stabilizing and supporting remittance flows can significantly enhance asset accumulation, savings, and financial inclusion, and consequently increasing living standards. Effective management of remittance mechanisms is essential for maximizing their beneficial impact on household welfare. The second essay explores the effects of violent conflict events on the flow and frequency of remittances at the sub-national level. It utilizes detailed administrative data on remittance transactions from money transfer operators in eight developed countries (Australia, Canada, Denmark, Finland, Norway, Sweden, the UK, and the US), focusing specifically on remittances sent to Somalia at the district level. The study focuses on 65 out of 74 pre-war districts, analyzing data from January 2017 to December 2021, with a particular emphasis on 58 districts that consistently received remittances. By employing a fixed effects estimator to account for time and district-specific variations, the research finds that violent conflicts significantly disrupt remittance flows. Specifically, a one-month lag in overall violence correlates with reductions in both the amount and frequency of remittances. The analysis reveals varying impacts depending on the type of violence, with explosions and attacks on civilians leading to more substantial declines. Additionally, instrumental variable regression, using the African Union Transition Mission in Somalia (ATMIS) as an instrument, confirms that lagged violence conflicts reduce remittance flows and frequency. These findings highlight the urgent need for improved security and stability in conflict-affected areas to support and potentially increase remittance flows, which are important for household welfare in Somalia. Based on these results, it is recommended that policymakers develop strategies to lessen the effects of local conflicts on remittance flows to ensure the continuous availability of these critical external financial flows. The third essay investigates the impacts of external economic shocks, such as currency depreciation, regulatory de-risking measures, and increases in the Consumer Price Index (CPI) on remittance flows and frequency. Using administrative data from migrant transactions in Australia, Canada, Norway, Sweden, and the US for the period from January 2017 to May 2023, the study employs a staggered adoption design in combination with the Difference-In Difference (DID) method to analyze the effects of these external shocks on remittance patterns. The results indicate that economic disruptions lead to significant reductions in both the amount and frequency of remittances, and the impacts of such shocks vary (e.g., currency depreciation in Australia, regulatory de-risking measures in Norway and Canada, and increases in the CPI in Sweden each affect remittance flows differently). Extending the analysis with the DID method, the study quantifies the impact of exchange rate depreciation on remittance flows, revealing that a 5-10% depreciation (which proportionally increases the cost of sending remittances) leads to a 4% decrease in remittance amounts. Analyzing shocks by country shows that a 7% rise in remittance costs results in a substantial 12% decrease in remittance flows in Norway, while a 6% increase in costs corresponds to a 7% decline in Sweden. These findings underscore the importance of including such external economic shocks in policy considerations. Effectively addressing and reducing these external shocks is important for sustaining and potentially improving remittance flows, which are important for the economic stability of developing countries

Once an urban gull, always an urban gull? Migrating lesser black-backed gulls vary in whether or not they niche-track

Abstract not currently available

Exploring existentialism, power, and religion in modern Arabic literature: A comparison between Naguib Mahfouz and Reem Bassiouney’s literature

Abstract not currently available

Estimating the glacial valley fill of the north-west Greater Caucasus Mountains using artificial neural networks

Glaciation and subsequent glacier retreat has resulted in unknown quantities of sediments being stored in valleys throughout the Greater Caucasus Mountains. It is difficult to estimate the quantity of this sediment fill as a result of there being no direct measurements of the thickness of these sediments. In this study, valley cross-sections are extracted from a catchment area in the western Caucasus using a DEM. Training data comprised of valley widths and sediment depth estimates is obtained from these cross-sections based on assumptions about the geometry of glacially eroded valleys. This training data is used to train an artificial neural network to create a model which can be used to estimate sediment depths and associated volumes in other valleys in the Caucasus. This model was then applied to other valleys that were found to show evidence of glacial sediment fill. A volume of 42.05 ± 1.01 km3 is found from a combination of 7 valleys in the north-western and central part of the Caucasus which corresponds to a total mass of 8.83x1013 ± 8.67x1012 kg. The individual results from each valley showed that there is a relationship between the average width of the valleys and the maximum depth of sediment found within them. The results also highlighted that there are parts of the valleys that do not show evidence of glacial fill where they may be expected to. This presents implications for the glacial processes that impact the location of this sediment fill such as glacier motion and glacial erosion. The quantity and distribution of these sediments also have implications for isostatic adjustment associated with glacial retreat in the Caucasus as they demonstrate how mass has been transferred away from the mountains, which can contribute to the surface uplift resulting from ice mass loss

Fair group-based exposure of documents in ranked search results

The main objective in the development and deployment of Information Retrieval (IR) systems has traditionally been to ensure that users receive relevant information, for example by ranking documents with respect to the documents’ predicted relevance to the users’ information needs, as represented by the users’ queries. However, retrieval systems that only rank documents by predicted relevance can unintentionally introduce unfairness in the search results. In particular, search results can be unfair when groups of documents that are linked to specific entities such as individuals, organisations, or demographics are systematically ranked lower due to their associated attributes. Groups of documents that are ranked lower in the search results are less exposed to the user and therefore receive less attention. This lack of exposure can amplify biases and create unequal opportunities, thereby raising numerous ethical concerns and challenges. Therefore, in this thesis, we address the task of ensuring fairness in the search results. In particular, we aim to ensure fairness of exposure over groups of documents. Such groups are formed based on shared characteristics, such as a common associated geographic location, language, or other given attributes. Since maintaining relevance in the search results remains the main objective of every IR System, we aim to ensure fairness over the groups of documents without compromising the relevance or quality of the rankings. Indeed, search results that are perfectly fair according to a specific fairness definition but lack relevant documents would render an IR system ineffective and unusable. In this thesis, we provide insights into assessing exposure and demonstrate how IR systems using standard retrieval methods can be adapted to distribute exposure more fairly across groups of documents in search results while maintaining the quality of their results. We start our investigation by providing an overview of how exposure is distributed across document groups in search results. Based on our analysis, we argue that when adjustments to exposure distributions are necessary, modifying the ranked search results—by adding or removing documents from certain groups—is more effective than solely relying on re-ranking strategies. Moreover, we show that assessing the expected exposure distribution before implementing fairness-enhancing modifications to IR systems is a critical step. By evaluating how exposure is likely to be allocated among document groups prior to retrieval, potential disparities can be detected and the necessity and type of required fairness interventions can be determined. Specifically, we introduce a novel approach that predicts the exposure groups will receive prior to executing the retrieval process. Similar to Query Performance Prediction methods, which estimate the relevance of search results, our approach predicts how exposure will be distributed across groups of documents. Through experiments conducted over different document groups, we demonstrate that our proposed Group Exposure Predictor can assess the exposure distributions before traditional retrieval is performed. To assess or predict the exposure received by document groups, it is necessary to know the labels that define these groups. However, in practice, such labels are often incomplete or entirely unavailable. To address this issue, we propose a robust method for assessing exposure in search results when document labels are missing, through the use of Quantification techniques. Unlike traditional classification methods that infer individual labels, Quantification focuses on estimating the distribution of labels across groups. We argue that this approach is more suitable for group exposure assessment, as it directly provides the aggregate information needed to evaluate group-level disparities, rather than relying on potentially inaccurate individual predictions. To address unfair exposure distributions in search results, we propose adapting existing retrieval methods. Specifically, we argue that methods designed to increase the recall of search results are the most promising for adaptation, as adding more documents from underrepresented groups has a material impact on improving exposure distribution. To this end, we introduce a novel adaptation of the Graph-Based Adaptive Re-ranking (GAR) method to achieve a more fair exposure allocation over groups of documents in the search results. We propose several policies to adapt the GAR process and demonstrate through our experiments that each policy effectively improves the allocation of exposure across document groups in the search results, without compromising relevance. Another effective approach to increasing the recall of relevant documents in search results is through query modification. In this thesis, we propose several query modification techniques that adapt and extend existing retrieval methods to improve the representation of underrepresented groups in the search results. These include techniques such as query expansion, where additional terms are added to the original query to retrieve more diverse and relevant documents and pseudo-relevance feedback, where the system analyses an initial set of retrieved documents to refine the query. By incorporating these approaches, we aim to retrieve more relevant documents for groups with a low representation in an initial retrieval, thereby enhancing recall and promoting a more balanced allocation of exposure in final rankings. To successfully modify a user’s query, we propose to use pre-trained large language models to generate query terms and full queries that help retrieve more documents from underrepresented groups. Through our empirical evaluation, we show that all of our techniques are suitable for improving the exposure distribution over groups of documents while maintaining the relevance and quality of the search results. Overall, this thesis contributes to a growing body of research on fairness in IR systems. By addressing key challenges in balancing relevance and fairness, this work provides novel insights and practical methods for improving the equitable distribution of exposure in search results. Through the development of predictive models, robust measurement techniques, and adaptations of effective retrieval methods, including recent generative AI approaches, this thesis advances both the theoretical understanding and practical implementation of fairness-aware IR systems. These contributions not only enhance the design of more inclusive and socially responsible retrieval systems but also open new avenues for future research in this critical and evolving field

Effectively cornering new physics at colliders and beyond

The Standard Model has achieved remarkable success, yet growing empirical and theoretical tensions point to the need for new physics at the TeV scale. As collider experiments enter a precision era, even small deviations from Standard Model predictions can provide crucial clues about the underlying structure of fundamental interactions. This thesis explores these possibilities through both model-dependent studies and the effective field theory approach. Multi-Higgs production is used to probe extended scalar sectors, offering insight into the nature of electroweak symmetry breaking and the dynamics of possible phase transitions. Electroweak-scale triplet models are examined through collider signatures and flavour constraints, presenting a realistic mechanism for radiative neutrino mass generation. In the top-quark sector, momentum-dependent width effects are implemented in a gauge-consistent way, leading to more accurate predictions for SMEFT constraints. To address the challenge of high-multiplicity final states, machine learning techniques, including graph neural networks, are applied to identify hidden correlations and enhance signal sensitivity. Together, these studies sharpen existing bounds and provide complementary strategies to guide future experimental efforts at the High-Luminosity LHC and beyond

Electroencephalograph predictors of central neuropathic pain in subacute spinal cord injury

Abstract not currently available

Postcolonization of university accounting education: case of Sri Lanka

This study addresses a notable research gap by offering an institutional-level analysis of how and why university accounting education in an ex-colony interacts with the global accountancy discourses and practices. Adopting a postcolonial lens, it examines how and why Sri Lanka's first accounting degree programme engages with global accountancy discourses and practices. Both the literature and my pre-understanding suggest that university accounting education in ex-colonies often reproduces global discourses and practices, as adopted by local professional accounting bodies (PABs). To provide a comprehensive understanding, the study explores the interaction between Institute of Chartered Accountants of Sri Lanka (CA Sri Lanka) and the global accountancy discourses and practices. The findings highlight a complex interplay of complicity and resistance (ambivalence) among key constituencies of CA Sri Lanka has led the local PAB to replicate global discourses and practices, including reproducing global curricula, implementing Mutual Recognition arrangements (MRAs), and adopting International Financial Reporting Standards (IFRSs) and International Standards on Auditing (ISA). This has resulted in CA Sri Lanka developing a hybrid identity as a "globalised local institute," aimed at producing accountants aligned with global capital demands, thus enhancing their global mobility. Similarly, the study of B.Sc. Accounting (Hons.) degree programme reveals that ambivalence among its key constituencies has driven the programme to replicate global discourses and practices, including adopting PAB-based curricular, seeking exemptions and accreditations from PABs, and promoting global standards such as IFRSs and ISA. This has created a hybrid identity for the degree programme: a globally recognised, professionally oriented academic qualification. Through this, the degree programme aims to produce graduates who are prepared to serve global capital, thereby enhancing their employability in international markets, which resembles that of CA Sri Lanka. This thesis contributes to postcolonial studies in accounting by offering a nuanced institutional-level analysis of global-local interactions within accounting profession and education in an ex-colony, from the perspective of colonized