SACM - United Kingdom
Permanent URI for this collectionhttps://drepo.sdl.edu.sa/handle/20.500.14154/9667
Browse
4335 results
Search Results
Item Restricted Investigation of Novel Type III Secretion System Protein Effectors of Aeromonas veronii(Saudi Digital Library, 2025) Alfaify, Abdulkhaleg; Shaw, JonathanThe type III secretion system (T3SS) plays a crucial role in the pathogenesis of various Gram-negative bacteria, enabling them to directly inject effector proteins into host cells. This study focuses on the identification, characterization, and functional analysis of putative T3SS effector proteins (AopX, PteB, and PteA) in Aeromonas veronii. Insertional gene mutants were generated and evaluated using the Galleria mellonella larvae infection model, showing significant alterations in virulence phenotypes. Transcriptomic analysis of an exsD mutant strain provided insights into the regulation of these novel effectors and demonstrated that they were part of theT3SS regulon. The study further characterized these proteins through expressing them in both Saccharomyces cerevisiae and A549 mammalian cells. Fluorescence imaging analysis showed that these proteins had significant impacts on host cell morphology and cytoskeletal organization. Additionally, BioID proximity labelling combined with mass spectrometry proteomics analysis identified host protein interactions and key cellular pathways that influenced by these bacterial effectors. Furthermore, protein purification was optimized using various chromatography approaches and computational modelling via AlphaFold and Phyre2 was used to predict and align protein structures. Overall we found that AopX, PteB, and PteA are regulated by the T3SS regulon. AopX primarily disrupts the actin cytoskeleton in both yeast and A549 cells, most probably through interacting with Filamin A, while PteB prevents bud formation and affects cell cycle progression by interacting with Serine/Threonine phosphatases. This comprehensive investigation enhances our understanding of T3SS effector proteins in A. veronii pathogenesis and provides insights into their regulation, structural features, and specific mechanisms of host cell manipulation.11 0Item Restricted Design and Analysis of Next Generation Wireless Networks(Saudi Digital Library, 2025) Altuwairgi, Khaled Humaid; Hamdi, KhairiRecent advancements in wireless communications have increased the demand for high data rates, massive connectivity, high spectral and energy efficiency, and low latency, which cannot be met by existing systems. The sixth-generation (6G) wireless network is envisioned as the next step to support these demands by integrating technologies, including intelligent reflecting surface (IRS), backscatter communication, non-orthogonal multiple access (NOMA), integrated sensing and communication (ISAC), and terahertz (THz) communications. Specifically, the IRS enhances the energy and cost efficiency by controlling the propagation environment through an array of reflecting elements. Backscatter communication enables passive battery-free devices to communicate using external RF signals, offering an energy-efficient and low-cost solution for the Internet of Things (IoT) paradigm. NOMA improves spectral efficiency and massive connectivity by allowing multiple users to share the same time-frequency resources, while ISAC combines sensing and communication functionalities into a single system for efficient spectrum and hardware usage. Finally, THz communication addresses the current limited spectrum by providing extensive bandwidth that supports ultra-high data rates. This thesis studies the integration of these technologies with a special focus on IRS and backscatter communications, considering various system models and realistic scenarios. It evaluates the performance of IRS-aided backscatter communication in both dedicated and ambient configurations using different detection techniques and transmission schemes. It also investigates IRS-assisted THz to serve multiple users through NOMA and wireless powered communication under various practical scenarios. Moreover, it explores the integration of ISAC with ambient backscatter communication. The thesis identifies the potential benefits of these technologies and examines the adverse impacts of practical factors such as beam misalignment, co-channel interference, imperfect successive interference cancellation, phase shift quantization errors, and hardware imperfection. Accurate analytical expressions are developed for key metrics, including bit error rate, ergodic capacity, and outage probability, under various system models and transmission schemes. Numerical and simulation results are provided to validate the accuracy of the theoretical analysis and provide valuable insights into the system design.9 0Item Restricted Sustainable Waste Management of Date Palm Fronds in Saudi Arabia: Pyrolysis-Derived Biochar Integration into Construction Materials for Carbon Sequestration(Saudi Digital Library, 2024-09) Shaiban, Saad; Scott, BanksThis study focuses on integrating biochar derived from date palm fronds into cement production in Riyadh, Saudi Arabia (KSA), to optimise carbon sequestration (CCS) and reduce carbon emissions. Employing a mixed-method approach, the research combines quantitative Life Cycle Assessment (LCA) using SimaPro software with qualitative sustainability analysis through the Bioeconomy Sustainability Indicator Model (BSIM) and Sustainable Development Goals (SDGs) indicators. Phase 1 compares the environmental impact of traditional open combustion versus pyrolysis for biochar production, revealing that pyrolysis significantly reduces carbon emissions from 3.5 tons CO₂-equivalent per ton of waste to 646 kg CO₂-equivalent. This substantial reduction supports Riyadh's climate goals and aligns with KSA’s Vision 2030 sustainability objectives. Phase 2 evaluates the integration of biochar into cement mortar, showing that a 20% substitution of cement with biochar reduces emissions by 24.81 kg CO₂-equivalent per ton of mortar, potentially saving up to 1,796 million tons of CO₂-equivalent annually based on current cement production levels. The sustainability analysis using BSIM highlights benefits such as job creation and economic growth while identifying transportation logistics risks and production efficiency risks. Additionally, the study assesses contributions to SDGs, particularly in climate action, sustainable cities, and responsible consumption and production. The study recommends optimising the supply chain, investing in advanced pyrolysis technology, and supporting market development through policy incentives. Future research should focus on the long-term performance of biochar, explore additional applications in agriculture and water treatment, and further integrate biochar into sustainable construction practices. This research provides valuable insights for advancing sustainable waste management and construction practices in Riyadh, contributing to climate action and supporting regional and global sustainability efforts.9 0Item Restricted Development of a home based resistance exercise programme for muscle strength and function during weight loss(Saudi Digital Library, 2025) Binmahfoz, Ahmad; Gray, StuartThesis abstract Background The prevalence of obesity continues to increase, representing a major public health concern across the globe. While dietary interventions can reduce body mass, the concurrent loss of fat free mass and muscle strength is a potentially deleterious consequence. Resistance exercise may help preserve muscle mass and function during weight loss, yet its implementation remains challenging. This thesis investigated the potential of home-based resistance exercise to attenuate these deleterious effects of weight loss through three research studies. Methods Study 1 included a systematic review and meta-analysis examining the effects of resistance exercise on body composition, muscle strength, and cardiometabolic health during dietary weight loss. Study 2 employed qualitative methods to explore experiences and perceptions of resistance exercise among people living with overweight or obesity (n=11), informing a theory of change for intervention development. Study 3 evaluated the effects of a 12-week home-based resistance exercise intervention, during dietary weight loss, through a randomised controlled pilot trial (n=48). Results The systematic review and meta-analysis (25 RCTs) demonstrated that supervised resistance exercise during dietary weight loss preserved fat free mass (SMD: 0.40, p<0.001), increased fat mass loss (SMD: -0.36, p<0.001), and improved muscle strength (SMD: 2.36, p<0.001) relative to a no exercise control. The qualitative study identified multiple barriers, including pandemic-related limits, access to facilities and financial constraints to traditional gym-based resistance exercise, and indicated strong preferences for home-based alternatives. The pilot trial showed that, during weight loss, home-based resistance training improved grip strength (p=0.046), knee extensor maximal voluntary contraction force (p=0.019) and sit-to-stand performance (p<0.001), but did not have any effects on body composition (body mass index, total body mass, fat mass, fat free mass, muscle thickness) compared to dietary weight loss alone. Conclusions The current thesis demonstrates that supervised resistance exercise enhances the benefits of diet induced weight loss by preserving muscle mass and improving muscle function. The development and evaluation of a home-based programme showed promising results for overcoming traditional barriers to resistance exercise participation and improving muscle strength and function, but not muscle mass. These findings support the implementation of accessible resistance exercise interventions during weight loss for people living with overweight or obesity.12 0Item Restricted Exploring expression of neurodevelopmental susceptibility genes in the foetal human thalamus and other related structures(Newcastle University, 2024) Alhesain, Maznah; Fiona, LeBeau; Gavin, ClowryThe thalamus is a brain region consisting of neuronal clusters and with a large number of connections which are responsible for several important functions including cognitive functions. It serves as a major relay centre, transmitting and modulating information between the cerebral cortex and subcortical structures. Given its involvement in higher-order cognitive functions, abnormalities in thalamic development have been implicated in various neurodevelopmental disorders, including schizophrenia and autism spectrum disorders. However, the developmental process of these nuclei in the human brain is still unknown. Understanding the developmental trajectory of the thalamus in humans is essential for several reasons. Firstly, while rodent models have provided insights into thalamic development, there are significant species-specific differences in the timing, organization, and molecular regulation of thalamic nuclei formation. These differences necessitate direct investigation of human developmental processes to bridge the gap between animal models and human neurodevelopment. Secondly, delineating how thalamic nuclei emerge during early foetal development may provide critical information on the origins of functional specialization within the thalamus, shedding light on how distinct neuronal populations are specified and how their connectivity is established. Finally, by identifying molecular markers and gene expression patterns specific to early thalamic development, we can gain a deeper understanding of the genetic and cellular mechanisms that may contribute to neurodevelopmental disorders, potentially informing future diagnostic and therapeutic approaches. This study aims to investigate gene expression patterns in the human thalamus, extending from 8 to 21 PCW, in order to track the development of each thalamic nucleus. Additionally, we focus on 14 PCW to identify distinct thalamic nuclei based on the expression of a unique combination of transcription factors and other genes/proteins. We also aim to investigate the expression of susceptibility genes linked to neurological diseases such as FEZ1, NRXN1 regarding their expression in specific thalamic nuclei. The methods we used are immunostaining and RNAscope in situ hybridisation, including double staining methods for multiple markers. Sections were taken from human early foetal brains (ethically sourced and supplied by the Human Developmental Biology Resource), in all planes and covering the extent of the diencephalon. Sections taken at 14 PCW were aligned with 3-D maps of the forebrain collected by structural MRI scanning. The expression of combinations of markers were localised to particular regions of the thalamus. We also analysed open source scRNAseq data with the aim of identifying clusters of cells grouped by shared gene expression patterns. We also investigated the expression of neurodevelopmental disease susceptibility genes in specific nuclei and cell types of the thalamus and telencephalon. This study provides significant insights into the early development of the human thalamus and telencephalon. The study highlights distinct gene expression patterns and the emergence of thalamic nuclei from a protomap. Our findings demonstrate that different transcription factors and molecular markers define specific thalamic regions, reinforcing the concept that a structured thalamic map begins to emerge by 14 PCW. Furthermore, we identified 15 distinct groups of cells with functional characteristics, supporting the notion that thalamic differentiation is an intricate and highly regulated process. It also implicates that neurogenesis and extensive cellular migration are critical processes during this crucial period. The differential expression of neurodevelopmental disease susceptibility genes in the thalamus further underscores the importance of studying early thalamic development in the context of neurological disorders. The high expression of FEZ1 in progenitor cells, transitioning to glutamatergic neurons, and the elevated presence of NRXN1 in the thalamus suggest potential roles in neuronal connectivity and function. These findings may provide critical clues for understanding the etiology of conditions such as schizophrenia, where thalamic dysfunction has been implicated. Overall, this study bridges a crucial gap in our knowledge of human thalamic development, and lay the foundation for future research into the molecular mechanisms underlying thalamic organization. Further investigations, including functional studies and longitudinal analyses, will be essential for uncovering how early developmental events shape thalamic function and its implications for neurodevelopmental and neuropsychiatric disorders.6 0Item Restricted Corporate Social Responsibility (CSR) and Its Influence on Employee Loyalty and Engagement in Saudi Arabia(Coventry University, 2025) Alsaadi, Halah; Lawton, Natalia RochaThis study investigates the influence of Corporate Social Responsibility (CSR) approaches in Human Resource (HR) practices on employee loyalty and engagement within Saudi Arabia’s healthcare sector, a context shaped by the nation’s Vision 2030 reforms. Drawing on Stakeholder Theory and Social Identity Theory, the research explores how CSR dimensions environmental, social, and governance (ESG) integrated into HR policies can foster organizational commitment, retention, and employee identification. A qualitative, interpretivist methodology is employed, utilizing secondary data from peer-reviewed studies, government reports, and institutional publications, analysed thematically to identify patterns and implications. Findings reveal that genuine, culturally aligned CSR initiatives embedded in HR practices such as staff welfare programs, ethical governance, environmental sustainability measures, and community engagement significantly enhance employee trust, pride, and loyalty. Sectoral differences emerge, with public healthcare CSR focusing on societal welfare, while private sector efforts prioritize direct employee benefits. The study underscores the strategic role of CSR as both a driver of workforce stability and a tool for aligning organizational goals with national priorities. Recommendations emphasize transparent, authentic CSR integration into HR strategies to strengthen engagement and retention, contributing to sustainable organizational performance in the evolving Saudi healthcare landscape.7 0Item Restricted Narratives From The Margins: A Comparative Study of Exile and Subalternity in Dina Nayeri’s Refuge and Kiran Desai’s The Inheritance of Loss(University of Nottingham, 2025) Alhujuri, Amal; Matthews, Sean; Rounce, AdamUsing Kiran Desai’s The Inheritance of Loss and Dina Nayeri’s Refuge as primary texts to analyse, with a focus on asylum seekers, refugees, and women as marginalized and subaltern voices, this dissertation tries to examine how marginalization, recurrent displacements, and exile affect one’s identity and culture while examining how the subalterns have been silenced and marginalized in different cultures and situations. The study draws on the theoretical perspectives of Salman Rushdie, Edward Said, and Azar Nafisi to analyse the consequences and impacts of exile and displacement physiologically and culturally. In addition, it uses Gayatri Chakravorty Spivak’s ideas of subalternity and Chandra Talpade Mohanty’s critiques of the concept of “global sisterhood” to assert the uniqueness and disparities of women’s struggles worldwide. Therefore, it argues that such marginalized voices should be acknowledged and heard, which will allow them to represent themselves and foster understanding.15 0Item Restricted The USA banking performance pre and post the crisis: how the bank size influenced the performance?(University of Leeds, 2025-03) AlSamah, Ibrahim; Cave, JoshuaThis dissertation investigates how bank size influenced the U.S. banking performance in terms of profitability during the 2008 financial crisis. The crisis originated in the United States which led to worldwide economic instability. Categorising banks into two groups: small - large and considering two distinct time periods pre-crisis (2002-2006) and post-crisis (2007-2013), the dissertation conducts a cross-sectional analysis to explore bank behaviour patterns, highlighting similarities and differences. In addition, considering the main literature contributions, the dissertation predicts that small banks were more resilient than their counterparts. To address the research objective, the dissertation tests the mentioned hypothesis using the regression analysis (OLS, fixed and random effect models), which examined the relationships between size, liquidity, leverage and profitability.2 0Item Restricted The Sweet Spot: A Dessert Shop and Cafe in Riyadh, Saudi Arabia(DE MONTFORT UNIVERSITY, 2024) Almutairi, Fahad; Simon, HillThis dissertation explores the establishment of “The Sweet Spot,” a dessert shop and café in Riyadh, Saudi Arabia, offering authentic French desserts with a healthy twist by incorporating fresh fruits, nuts, and low sugar content. The study analyzes market gaps, identifies potential opportunities in the Saudi dessert sector, and evaluates current competitors. Using Porter’s differentiation strategy, it proposes a business model targeting health-conscious and premium consumer segments through dine-in, takeaway, and home delivery channels. The research further outlines a comprehensive marketing strategy, stakeholder management approach, and financial analysis, demonstrating the project’s viability and potential for expansion through new branches and franchising.6 0Item Restricted A systematic Review of the Consequences of Parents’ Divorce and Challenges of Raising Children between Saudi Arabia and the United Kingdom(Bangor University, 2024) Qahtani, Wasmmih Nayef; Margiad, WilliamsAbstract Purpose: The objective of this study is to assess the emotional, psychological, and social effects of parental divorce on children in the United Kingdom and Saudi Arabia as well as the challenges parents face in parenting after divorce in the two cultures. Methodology: A pragmatic research paradigm was adopted for conducting a systematic review. Literature relevant to the project was then identified, screened, and assessed in line with the PRISMA framework. The approach was a mixed-methods one, using qualitative findings, and supported with quantitative data. The assessment of key themes was conducted through narrative analysis. Results: The children in the UK brought up in an emotionally expressive climate have significant emotional and behavioural issues post-divorce. Saudi children, especially girls, however, are taught to suppress emotions as a cultural norm. Co-parenting challenges are different, with UK laws favouring shared custody but lacking emotional safeguards, and Saudi laws favouring paternal custody and limiting involvement. Conclusion: The experiences children have after a divorce are shaped by cultural values and legal systems and therefore need context specific support strategies. Keywords: Divorce, children, co-parenting, UK, Saudi Arabia, culture, emotional impact4 0