Saudi Cultural Missions Theses & Dissertations
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Item Restricted Mechanistic Studies of the Formation and Reactions of Organometallic Intermediates in the Gas Phase.(Saudi Digital Library, 2025-07-25) Altalhi, Weam A. O; Richard A. J. O’HairOrganic synthesis focuses on constructing molecules through strategic bond transformations at various types of carbon atoms. The 2010 Nobel Prize recognized palladium-catalyzed cross- coupling reactions, which involve the transmetalation process. While Suzuki reactions are well- studied, fundamental data (e.g., thermochemistry) on transmetalation remain scarce. This thesis brings a mechanistic lens into aspects of the formation and reactions of organometallic intermediates relevant to elementary steps in catalytic cross-coupling reactions, utilizing various mass spectrometry-based approaches and DFT calculations. Gas-phase ion–ion reactions between tris(1,10-phenathroline) transition metal dications and the tetraphenylborate anion, presented in chapter 2, were used for the first time to investigate the formation of ion-pairs in the gas-phase and their role as precursors to transmetalation reactions. Initial formation of outer sphere ion-pair [(phen)3M][BPh4]+ is highly exothermic and the excess energy can fuel loss of a phen ligand to form the inner sphere ion-pair [(phen)2M][BPh4]+, which is a key precursor to transmetalation to form the organometallic cations [(phen)nMPh]+. The gas-phase ion–ion reaction approach was extended, presented in chapter 3, to an investigation into the formation of ion-pairs derived from a f-block metal and their role as precursors to transmetalation reactions. Electron transfer is the dominant pathway and produces the ytterbium dication [Yb(II)(L)3]2+ (6b). One of the simplest cationic copper(II) aryl complexes with a bidentate chelating ligand, presented in chapter 4, [(phen)Cu(Ph)]+, has been prepared in the gas phase through three routes: transmetalation of [(phen)3Cu][BPh4]+, desulfination of [(phen)Cu(O2SPh)]+ and decarboxylation of [(phen)Cu(O2CPh)]+. The bimolecular reactivity of these organocopper(II) cations towards a range of organic substrates was evaluated for their ability to undergo C–H, C–C, C–I, and C–S bond forming reactions. The aim of the work presented chapter 5 in this chapter was to translate the organocopper [(phen)Cu(Ar)]+ observed in the gas-phase to the solution phase using the concept of pseudo gas phase conditions pioneered by Prof. Krossing. Chapter 6 explored the gas-phase decarboxylation of alkali metal complexes in the gas-phase using the fixed charge ligand [4-(CH3)3N(C6H4)CO2] consisting of a benzoate substituted with a cationic quaternary ammonium group at the para-position. CID of the carboxylate complexes [4-(CH3)3N(C6H4)CO2M]+ (M = Li, Na, K, Rb and Cs) produced the mono nuclear organoalkali cations [4-(CH3)3N(C6H4)M]+ in all cases, which is consistent with DFT calculations which reveal that loss of the alkali cation via bond heterolysis is higher in energy than decarboxylation. Additionally, other surprising product cations were observed and these were rationalised as products of a SN2 reaction between the alkali hydroxide (MOH) and the quaternary cation (CH3)3N(C6H5)+ within the exit channel ion-neutral complex via a roaming mechanism. Chapter 7 covers a theoretical study to establish a methide affinity (MA) scale for permethylated cations, neutrals, and anions from elements of both the s and p blocks. The calculated MA values shows that the cations are mostly positive indicating the stability of neutrals towards methide loss. However, the MA values of the anions are all negative, indicating that the dianions thermodynamically unstable with respect to methide loss. Three systems Me4Ca2−, Me4Sr2−, and Me4Ba2− calculated to be kinetically stable and thus might be observable in the gas phase.8 0Item Restricted Corporate Taxation, Income Shifting, and Behavioural Outcomes: Implications for Financial Decision-Making and Reporting(Saudi Digital Library, 2025-07-25) Almohaimeed, Ahmed Abdullah A; Grantley, Taylor; Lien, DuongThis thesis consists of three essays that examine the effects of the 2017 U.S. Tax Cuts and Jobs Act (TCJA) on corporate behavior and outcomes, focusing on income shifting, investment decisions, and accounting reporting design. The TCJA, one of the largest tax reforms in U.S. history, fundamentally altered the U.S. tax system which transitioned from a worldwide to a territorial system. These essays provide empirical evidence as to how this landmark reform influenced corporate financial strategies, tax practices, and reporting behavior. Together, these essays contribute to the ongoing discussion on the effectiveness and impacts of the TCJA, shedding light on how tax reform influences corporate debt strategies, investment behavior and tax compliance. This thesis offers valuable insights for policymakers and academics interested in the intersection of tax policy, corporate governance, and financial decision-making. Chapter 1 documents the purpose and objectives of this research and provides an overview of each of the main sections of the thesis. Chapter 2 entitled “The impact of the Tax Cut Jobs Act and income shifting on the cost of bank loans”, investigates whether changes in income shifting incentives following the TCJA are associated with a shift in the cost of bank loans for U.S. multinational corporations (MNCs). The study finds that the TCJA reduced bank loan costs and altered the relationship between income shifting incentives and loan pricing, particularly in environments characterized by weak information transparency, lower IRS audit probability, stronger corporate governance, higher R&D investments, and greater liquidity. Chapter 3 entitled “The Tax Cuts and Jobs Act legislation and corporate behavioral outcomes”, examines the broader effects of the TCJA on corporate behavior, including changes in investment decisions, cash holdings, and payout policies for both U.S. MNCs and domestic firms. The findings reveal distinct post-TCJA patterns: U.S. MNCs reduced capital expenditures, increased cash reserves, and raised dividend payouts and share repurchases, while domestic firms primarily increased cash holdings and share repurchases. The study highlights the shift toward more domestic investment by MNCs and provides critical insights into how the TCJA reshaped corporate financial strategies. Chapter 4 entitled “Income-shifting arrangements of U.S. multinational corporations and accounting reporting design”, focuses on the role of XBRL (eXtensible Business Reporting Language) tags in reducing aggressive income-shifting practices among U.S. MNCs. Using a large sample of firm-year observations, the study demonstrates a significant negative association between income shifting and the design of accounting reports, as measured by the number of XBRL tags. This association is particularly pronounced for firms with tax haven subsidiaries, multiple offshore subsidiaries, and lower ESG scores. The results suggest that the adoption of XBRL reporting enhances the efficiency of IRS audits, thereby mitigating income-shifting incentives. Chapter 5 concludes the thesis and outlines directions for future research.12 0Item Restricted Similarities and Differences in Two Adult Learners’ Communicative Repertoires in Arabic as an Additional Language: A Study of Sociolinguistic and Contextual Alignment in the Saudi Hijazi Context(Saudi Digital Library, 2025-05) Bugshan, Omar Ahmed S; Howard, NicholasFramed by the principal research question, “How do L2 learners of Arabic develop their communicative repertoire?”, this thesis investigated how two adult learners of Arabic as an additional language developed their communicative repertoires within the complex sociolinguistic environment of Arabic-speaking contexts, with a specific focus on the Hijazi Arabic context of Jeddah city in the Western territory of Saudi Arabia. I conceptualise second language learning as a socially embedded process, in which sociocultural and contextual features shape each communicative act, I used the Multiplicity framework of the communicative repertoire (Nicholas & Starks, 2014; 2019). Intersections between its four dimensions of Modes, Mediations, Varieties and Purposes offer a new way of understanding the flexibility of SLA processes. I examined the communicative resources learners noticed and selected during interactions and how they aligned and deployed these resources across varied sociocultural contexts. The two case studies based on individual interviews and focus-group discussions, all in Arabic, revealed communicative repertoire development as a dynamic and individually-mediated process shaped by learners’ sociocultural awareness, access to interaction and recognition of sociolinguistic variation. Where one participant conformed to previous studies of adding dialectical varieties to the standard target language, the other actively resisted a standard orientation and, from the outset of her additional language acquisition, engaged actively with multiple varieties, including the standard language. The first case study was shaped by limited early opportunities for social negotiation and reduced exposure to varied Arabic-speaking contexts, delaying the recognition of sociolinguistic variation until later experiences in Jeddah. The second case study was distinguished by early, sustained and multimodal engagement with multiple Arabic varieties, facilitated by social friendships, digital interactions and lived experiences across diverse social settings. The findings have implications for SLA theorising and the pedagogy of multidialectal teaching and socially-anchored Arabic language learning.11 0Item Restricted Saudi Families-Teachers Partnerships and Attitudes Towards Families' Involvement in Early Childhood Inclusive Education(Saudi Digital Library, 2025) Alotaibi, Wadha; Evans, David; O'Donovan, Mary-AnnThis study describes the families' involvement in their child's learning in inclusive early childhood settings in Riyadh, Saudi Arabia. It aims to examine the family-school partnerships level, and attitudes of those surrounding a child regarding family involvement, including the role of both parents in their child's learning within these environments, as well as the attitudes of teachers and providers. Bronfenbrenner’s bio-ecological systems theory (1979, 2009) has been employed to support the current study conceptualisation as it provides an analytical lens considering multiple environments and relations (e.g., preschool and family), which have direct influence on children across inclusive early childhood settings. Subsequently, certain factors that could underpin participants’ perspectives on family involvement were examined. These included but were not limited to, age, education level, teaching experience, and number in family. This study is considered the first to focus on three important groups: special and general early childhood teachers, service providers, and parents, including fathers. It is, moreover, the first study to involve fathers as participants in surveys and interviews within the Saudi early childhood context, which is predominantly female dominated. The study analysed surveys from 265 participants to initially explore attitudes towards family involvement. Following this, semi-structured interviews were developed and conducted with 17 participants, to gain a deeper understanding and explanation of the enablers and barriers participants face regarding family involvement in their child's learning. In the quantitative phase of this study, parents had the most positive attitudes towards family involvement. At the same time, the number of children per family emerged as a key element affecting parental involvement. Surprisingly, variables traditionally thought to influence such attitudes, including the age of the parents and their level of education, did not show a meaningful impact on the level of family involvement. Conversely, interviews suggested that a lower educational level among parents may adversely impact their involvement in their children's education. Another key finding is that all participants overwhelmingly focused on the difficulty of involving fathers in Saudi early childhood education, citing traditional and preschool structural reasons. Families are involved in their child's learning differently, depending on the unique attributes and barriers present in various preschools. This thesis emphasises the contributions of family, including fathers, to their children's education. The study provides an original notion of the barriers to fathers' involvement, and suggestions to facilitate this issue in the Saudi context. The findings are expected to aid in the reconsideration of family involvement in inclusive preschool environments.8 0Item Restricted Cloud-Computing for Carbon Finance Decision Support System with Dynamic Machine Learning Repository Management Service(Saudi Digital Library, 2025-06-20) ALTHUNAYYAN, AZZAM; Dong, Yuan; Liu, Charles ZThis thesis presents the development of a local machine learning-based decision support system designed to predict future carbon prices. Carbon finance markets play a critical role in supporting global climate change mitigation strategies, where market price volatility poses substantial challenges for investors, policymakers, and carbon traders. This research integrates and compares five advanced forecasting models — Extreme Gradient Boosting (XGBoost), Light Gradient Boosting Machine (LightGBM), Categorical Boosting (CatBoost), Facebook Prophet, and Autoregressive Integrated Moving Average (ARIMA)—by training and evaluating them on historical carbon price datasets to identify the optimal predictive approach. The system is implemented as a Spring Boot web application operating in a local environment, serving as a functional proof-of-concept for potential future deployment on scalable cloud infrastructure. The models are evaluated using performance metrics such as Root Mean Square Error (RMSE), Mean Absolute Error (MAE), and the coefficient of determination (R²). Results demonstrate that the selected best-performing model offers superior forecasting accuracy and robustness under varying market conditions. This work contributes to the intersection of carbon finance and artificial intelligence by delivering an extensible, locally operable system that lays the groundwork for future cloud-based deployment, supporting informed decision-making for stakeholders in the carbon trading ecosystem.27 0Item Restricted Implementing a Standardized Operating Room Turnover Time Measurement System to Improve Operating Room Efficiency(Saudi Digital Library, 2025) Alhoti, Abdulrahman; Christine, McCloudOperating Room (OR) turnover time (ToT) significantly affects surgical workflow efficiency, patient outcomes, and hospital financial sustainability. This Practice Improvement Project (PIP) aimed to address prolonged OR ToT observed in a hospital setting by implementing a standardised, automated ToT measurement system. Using a Plan-Do-Study-Act (PDSA) cycle and co-design approach, the project involved stakeholders across departments to define turnover phases, collect real-time data, and provide actionable feedback. Data were gathered through automated tracking, interviews, observations, and electronic health records to assess the system’s effectiveness. Results focused on OR efficiency, patient and staff satisfaction, and reduction in adverse postoperative outcomes. Implementation barriers, such as technological resistance and resource constraints, were mitigated through change management strategies. The project demonstrated the potential of standardised ToT systems to improve operating room performance, reduce patient wait times, and enhance the safety and quality of surgical care. The findings support broader adoption and further research into AI-driven surgical efficiency tools.19 0Item Restricted Developing Real-time Corrosion Monitoring: A Cutting-Edge Fusion of Electrochemical Noise Data and Machine Learning Techniques(Curtin University, 2024-12-20) Abdulmutaali, Ahmed; Katerina Lepkova and Chris AldrichThe study addresses effectively monitoring and controlling the corrosion process using electrochemical noise analysis in different scenarios. It explores the challenges in feature extraction and analytical methods. It also proposes novel systematic approaches to overcome these challenges using deep learning models such as stochastic neighbour embedding (t-SNE) and principal component analysis (PCA). This work provides a potential quantification analysis method for online corrosion monitoring and control, widely considered the industry standard.27 0Item Restricted The Role of Chaperones in Outer Membrane Biogenesis and Host Cell Interactions in Neisseria Gonorrhoeae(Saudi Digital Library, 2025-05-30) Albalawi, Tawfiq; Wooldridge, Karl; Oldfield, NeilNeisseria gonorrhoeae, the gonococcus, is the aetiologic agent of the sexually transmitted disease gonorrhoea, which poses a global public health concern. Owing to the emergence of multidrug-resistant strains and the lack of an effective vaccine against this pathogen, novel interventions are required. The assembly of outer membrane proteins (OMPs) is essential for the survival and virulence of Gram-negative pathogens, such as N. gonorrhoeae. The periplasmic translocation and outer membrane (OM) assembly mechanism of OMPs is not completely understood, but it is dependent on the assistance of periplasmic chaperones. This study investigates the roles of three periplasmic chaperones - NGO1656, SurA and Skp - in the translocation and assembly of OMPs of N. gonorrhoeae, shedding light on their contributions to OM biogenesis and pathogenesis. To this end, the three chaperones were characterised by a bioinformatics approach to determine their degree of conservation across gonococcal strains. Subsequently, mutants of strain FA1090 with single or double knockouts of the periplasmic chaperones were generated using standard molecular biology techniques. Complemented derivatives of mutants were also constructed to validate the resulting phenotypes. The in vitro growth kinetics of the generated mutant and complemented strains were determined. The impact of individual or double deficiency of periplasmic chaperones on the overall OMP profiles was studied using SDS-PAGE. Moreover, the effect of the mutations on the assembly of individual OMPs, particularly those involved in iron acquisition, was tested using immunoblotting assays. The capacity of tested strains to colonise and invade host cells was examined by in vitro adhesion and invasion assays using human cervical carcinoma cells. Furthermore, biofilm formation was studied using a crystal violet assay. The results showed that NGO1656, SurA and Skp are highly conserved among gonococcal strains but are not essential for FA1090 viability under the conditions tested. The results of the 1D SDS-PAGE did not reveal any observable difference in OMP profiles between the mutant strains and the wild-type FA1090. However, immunoblotting analyses demonstrated that NGO1656 contributes to the translocation and assembly of transferrin-binding protein A (TbpA) and lactoferrin-binding protein A (LbpA), while Skp is the primary chaperone that contributes to the assembly and iv translocation of TbpB into the outer membrane. These results were confirmed by the reduced capacity of the mutant strains to use iron from human transferrin and lactoferrin in feeding assays. The three chaperones, especially NGO1656 were also shown to contribute to adhesion and possibly invasion. In addition, NGO1656 redundantly promotes the ability of gonococci to form biofilms together with SurA or Skp. Unlike E. coli SurA, N. gonorrhoeae FA1090 SurA does not appear to play a major role in translocation of OMPs to the outer membrane. These findings support the suggestion that the examined chaperones are viable options for therapeutic or preventive interventions against gonococcal infections, particularly when considered in the light of complementary data from other studies that demonstrated the chaperones are immunogenic and accessible to antibodies. This study reports for the first time on the contribution of NGO1656 in the acquisition of host-specific nutrients, adherence to host cells and biofilm formation in N. gonorrhoeae. Further investigations are needed to identify the exact role played by this periplasmic chaperone in these pathogenicity-related processes.7 0Item Restricted Sleep Disorders in Patients with Type 2 Diabetes(Saudi Digital Library, 2025) Makhdom, Esraa; Tahrani, Abd; Adderley, NicolaIntroduction Type 2 diabetes (T2D) is a growing global health challenge. Diabetes-related microvascular complications like retinopathy, nephropathy, and neuropathy contribute significantly to morbidity, mortality, and healthcare costs. Despite the significant efforts to manage glycaemic and metabolic control, the prevalence of these complications is rising. Gaining a deeper understanding of their underlying causes and exploring alternative preventive strategies are crucial in reducing the health and economic burden of T2D. Sleep disorders are highly prevalent among patients with T2D. The interrelationship between obstructive sleep apnoea (OSA), T2D, and microvascular complications is well established, with obesity recognised as a major risk factor. However, the impact of OSA treatment -continuous positive airway pressure (CPAP) - still needs to be investigated. Furthermore, the relationship between sleep disorders, including sleep duration and sleep quality, and T2D needs to be examined. Fragility fractures are also common among individuals with T2D, highlighting the need to explore whether OSA contributes to an increased risk of such fractures. Aims In this thesis, I aimed to assess the following: Aim 1: The impact of OSA treatment on microvascular complications in patients with T2D. Aim 2: The longitudinal relationship between sleep duration and obesity in patients with T2D. Aim 3: The relationship between sleep quality and microvascular complications in patients with T2D. Aim 4: The relationship between OSA and the risk of fragility fractures in patients with T2D. Methods To examine the first 3 aims, I used data collected from the SLEEP T2D study. SLEEP T2D is an observational cohort study with an embedded feasibility RCT in a subgroup of patients. The feasibility RCT is an open-label multicentre trial in which patients with OSA were randomised to CPAP vs No CPAP. For aim 4, I conducted a retrospective study in patients with T2D using data from the Clinical Practice Research Datalink (CPRD) Aurum, a real-world primary care database. Results For Aim 1: 83 participants fulfilled the eligibility criteria for the RCT and were followed up for 2 years. I found that OSA treatment had a favourable impact on diabetic peripheral neuropathy (DPN). It also had a favourable impact on the estimated glomerular filtration rate (eGFR), albumin-to-creatinine ratio (ACR), and quality of life. For Aim 2: 204 participants were included in the analysis and followed up for two years. Short sleep duration was defined as (≤ 6 sleep duration per night). The prevalence of short sleep duration was 54.9%. I found that short sleep duration was significantly associated with obesity, as measured by body mass index (BMI) and waist circumference. Additionally, I discovered that baseline short sleep duration was linked to weight gain in patients with T2D (P = 0.04). For Aim 3: 194 participants were included in this analysis. The prevalence of poor sleep quality was 75.8% (poor sleep quality was defined as PSQI > 5). The study did not show an association between sleep quality and diabetes-related microvascular complications, except for pain and adiposity measures in patients with T2D. For Aim 4: A total of 83,919 patients with T2D were included in cohort 1: 19,795 patients with OSA and 64,124 without OSA. 88,119 patients with T2D were included in cohort 2: 21,769 patients with OSA and 66,350 without OSA. OSA was associated with an increased risk of fragility fractures in patients with T2D compared to those with T2D but without OSA. This association persisted regardless of whether OSA was diagnosed before or after the diagnosis of T2D and remained significant even after adjusting for potential confounders. Conclusion Among patients with T2D, being randomized to CPAP showed a favourable association with improvements in diabetic peripheral neuropathy, diabetic nephropathy, and quality of life compared to those without CPAP. Furthermore, short sleep duration was associated with obesity and increased risk of weight gain in patients with T2D. Poor sleep quality was also significantly associated with obesity and pain in patients with T2D. Additionally, patients with both T2D and OSA had a significantly higher risk of fragility fractures compared to those with T2D but without OSA, regardless of whether OSA was diagnosed, proceeded or followed the diagnosis of T2D.9 0Item Restricted Theory of Quantum Transport in Molecular-Scale Structures(Saudi Digital Library, 2025) Alghamdi, Hajar; Lambert, ColinIn this thesis, the primary objective is to address the central question: how can the electrical conductance of azulene molecules be controlled, and how can a large on-off conductance ratio be achieved? To tackle this challenge, we employed two distinct strategies. The first strategy is to systematically vary the dihedral angle across a family of molecules. Accordingly, we pose the following research question: how can the modulation of the dihedral angle in the azulene molecule be optimized to maximize the on/off ratio of electrical conductance?. Furthermore, the second strategy is employed, involving the introduction of pendant groups through charge transfer complexes.6 0