Saudi Cultural Missions Theses & Dissertations

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    Treatment Strategies for Delayed Cerebral Ischaemia After Subarachnoid Haemorrhage: A Systematic Review
    (Queen Mary University of London, 1431-07-18) Alanazi, Abdullah; Zolfaghari, Parjam
    ABSTRACT Delayed cerebral ischaemia (DCI) is a devastating complication which may occur after aneurysmal subarachnoid haemorrhage (SAH). It significantly increases mortality among SAH patients and leads to poor functional outcomes. Due to uncertainty among researchers and healthcare professionals regarding the pathophysiology and clinical diagnosis of DCI, no sufficient treatment model has been proposed. Aims and Objectives: The aim of this study is to address the literature gap in the current recommendations on the treatment for DCI. In doing so, we aim to bring to light potential avenues for novel therapies, which have not yet been addressed by treatment models, and to inform directions for future research. Methodology: Three electronic databases (Pubmed, Medline, and Embase) were systematically searched for randomised control trials (RCT) and retrospective cohort studies that addressed various treatment methods of DCI. These included data on the use of statins, endovascular rescue therapy (ERT), calcium antagonists and vasodilators, assessing their efficacy and safety profile. Studies were included on the basis of predetermined inclusion criteria. Primary and secondary outcomes included mortality rate, ICU and hospital length of stay, incidence of vasospasm, and adverse events for each treatment modality. Results: A total of nine studies were included: 3 RCT and 6 retrospective cohort studies. No study reported a significant increase in adverse events, indicating that the included treatments are safe to use. A significant improvement in the severity of vasospasm was reported after the given treatment modalities; however, changes in functional outcome (Glasgow Coma Scale, Glasgow Outcome Scale, modified Rankin Scale) were not significant. Only the studies on statins included the length of hospital stay as a measure, which also showed insignificant results. Adjunct therapy of ERT with nimodipine appears to improve functional outcomes compared to single therapies. Conclusion: There is currently insufficient evidence for the addition of milrinone and statins to the current guidelines. However, adjuvant therapies show promise and more combinations should therefore be explored in the future. Keywords: Delayed cerebral ischaemia, cerebral vasospasm, aneurysmal subarachnoid haemorrhage, treatment, statins, endovascular rescue therapy, balloon angioplasty, nimodipine, milrinone
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    Saudi Arabian English Teachers' Perception About Teaching Speaking And Oral Communication In Secondary Public Schools
    (Brunel University, 1445-05-29) Aljnaidi, Alya; Aman, Ruth
    The overarching aim of this study was to understand the experiences of teachers who teach English speaking and oral communication in Saudi secondary schools to understand the challenges and recommend appropriate interventions. This study particularly investigated the subsequently delineated research question: "How do Saudi teachers perceive teaching English speaking and oral communication as a foreign language in secondary schools?” It additionally investigated the sub-questions: How do teachers perceive their own speaking skills and use of teaching practices in oral communication? What are the challenges of teaching oral communication and speaking in the context of English as a foreign language? In response to these questions, the interviews conducted with Saudi ELT teachers in the secondary schools revealed that teaching English speaking and oral communication skills is difficult because they lack exposure to the English Language and thus have limited knowledge of it. ELT teachers' limited knowledge of English was also attributed to poor training in phonology and the inability of education courses to meet their needs during pre-service training. As a result of prevailing knowledge gaps and limited exposure to the language, the interviewed ELT teachers reported that they lacked confidence in teaching English speaking and oral communication skills and tended to revert to using the Arabic language excessively to hide their deficiencies. The interviews conducted with Saudi ELT teachers in the secondary schools also revealed that teaching English speaking and oral communication skills is difficult because of system-level factors. These system-level factors pertain to the assessment methods employed by public secondary schools and the lack of resources. The interviewed Saudi ELT teachers noted that there is an absence of speaking and listening tests in their schools, which means that they are compelled to focus on reading, writing and grammar since assessment methods are primarily written. 4 Additionally, the teachers lamented about the skewed focus on textbook evaluation which means that important resources to support students' oral proficiency, such as audio CDs, are largely ignored and not provided. Finally, the interviews conducted with Saudi ELT teachers in the secondary schools revealed that teaching English speaking and oral communication skills is difficult because of student attitudes towards learning and cognitions about what constitutes a qualified ELT teacher. The teachers reported that most of their students conceptualize English as merely a subject that must be passed instead of a language they must learn to speak to communicate effectively with others.
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    Enhancing Graph-Routing Algorithm for Industrial Wireless Sensor Networks
    (University of Glasgow, 1445-08-18) Alharbi, Nouf Helal; Mackenzie, Lewis
    Industrial Wireless Sensor Networks (IWSNs) are gaining increasing traction, especially in domains such as the Industrial Internet of Things (IIoT), and the Fourth Industrial Revolution (Industry 4.0). Devised for industrial automation, they have stringent requirements regarding data packet delivery, energy consumption balance, and End-to-End Transmission (E2ET) time. Achieving effective communication is critical to the fulfilment of these requirements and is significantly facilitated by the implementation of graph-routing – the main routing method in the Wireless Highway Addressable Remote Transducer (WirelessHART), which is the global standard of IWSNs. However, graph-routing in IWSN creates a hotspot challenge resulting from unbalanced energy consumption. This issue stems from the typical configuration of WirelessHART paths, which transfers data packets from sensor nodes through mesh topology to a central system called the Network Manager (NM), which is connected to a network gateway. Therefore, the overall aim of this research is to improve the performance of IWSNs by implementing a graph-routing algorithm with unequal clustering and optimisation techniques. In the first part of this thesis, a basic graph-routing algorithm based on unequal clustering topologies is examined with the aim of helping to balance energy consumption, maximise data packet delivery, and reduce the number of hops in the network. To maintain network stability, the creation of static clusters is proposed using the WirelessHART Density-controlled Divide-and-Rule (WDDR) topology. Graph-routing can then be built between Cluster Heads (CHs), which are selected according to the maximum residual energy rate between the sensor nodes in each static cluster. Simulation results indicate that graph-routing with the WDDR topology and probabilistic unequal clustering outperforms mesh topology, even as the network density increased, despite isolated nodes found in the WDDR topology. The second part of this thesis focuses on using the Covariance-Matrix Adaptation Evolution Strategy (CMA-ES) algorithm. This addresses the three IWSN requirements that form the focus of this research, by proposing three single-objective graph-routing paths: minimum distance (PODis), maximum residual energy (POEng), and minimum end-to-end transmission time (POE2E). The research also adapts the CMA-ES to balance multiple objectives, resulting in the Best Path of Graph-Routing with a CMA-ES (BPGR-ES). Simulation results show that the BPGR-ES effectively balances IWSN requirements, but single-objective paths of graph-routing does not achieve balanced energy consumption with mesh topology, resulting in a significant reduction in the efficiency of the network. Therefore, the third part of this thesis focuses on an Improvement of the WDDR (IWDDR) topology to avoid isolated nodes in the static cluster approaches. The IWDDR topology is used to evaluate the performance of the single-objective graph-routing paths (PODis, POEng, and POE2E). The results show that in IWDDR topology, single-objective graph-routing paths result in more balanced energy consumption.
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