SACM - United States of America
Permanent URI for this collectionhttps://drepo.sdl.edu.sa/handle/20.500.14154/9668
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Item Restricted Next-Generation Diagnostics: Deep Learning based Approaches for Medical Image Analysis(Florida Institute of Technology, 2024-12) Alsubaie, Mohammed; Li, XianqiHigh-resolution medical imaging plays a pivotal role in accurate diagnostics and effective patient care. However, the extended acquisition times required for detailed imaging often lead to patient discomfort, motion artifacts, and increased scan failures. To address these challenges, advanced deep learning approaches are emerging as transformative tools in medical imaging. In this study, we propose a conditional denoising diffusion model-based framework designed to enhance the resolution and reconstruction quality of medical images, including Magnetic Resonance Imaging (MRI) and Magnetic Resonance Spectroscopic Imaging (MRSI). The framework incorporates a data fidelity term into the reverse sampling process to ensure consistency with physical acquisition models while improving reconstruction accuracy. Furthermore, it leverages a Self-Attention UNet architecture to upsample low-resolution MRSI data, preserving fine-grained details and critical structural information essential for clinical diagnostics. The proposed model demonstrates adaptability across varying undersampling rates and spatial resolutions, as a network trained on acceleration factor 8 generalizes effectively to other acceleration factors. Evaluations on publicly available fastMRI datasets and MRSI data highlight significant improvements over state-of-the-art methods, achieving superior metrics in SSIM, PSNR, and LPIPS while maintaining diagnostic relevance. Notably, the diffusion model excels in preserving intricate structural details, detecting small tumors, and maintaining texture integrity, particularly in glioma imaging for mapping tumor metabolism associated with IDH1 and IDH2 mutations. These findings underscore the potential of deep learning-based diffusion models to revolutionize medical imaging, enabling faster, more accurate scans and improving diagnostic workflows across clinical and research applications.12 0Item Restricted Unhealed Wounds: From Complex Trauma Exposure to Wellbeing and the Role of Coping(0023-07-23) Alsubaie, Mohammed; Bentley, JacobComplex Posttraumatic Stress Disorder (cPTSD) emerged as a theoretical construct reflecting symptoms beyond our current conceptualization of posttraumatic stress. Research examining its validity is still ongoing and cross-cultural research on the matter is emerging. An important risk factor to developing cPTSD is the experience of complex trauma, which constitutes experiences that reflect interpersonal violations of bodily boundary and integrity or betrayal (e.g., sexual assault and emotional abuse). There is still a gap in the literature linking complex trauma exposure to wellbeing or positive functioning in general. Survivors’ style of coping with trauma might influence later adjustment. With a sample of trauma survivors from Saudi Arabia, the present study evaluated the construct validity of cPTSD as well as examined the relationship between complex trauma and wellbeing as moderated by styles of coping. Results showed that all conceptualizations of complex trauma significantly predicted decreased wellbeing, but that such associations were not moderated by active nor passive style of coping. Factor and network analyses provided evidence for the construct validity of cPTSD, with the 6 first-order correlated factors model representing the best fit for the data, χ2 (155) = 431.373, p < .001, CFI = .941, TLI = .928, RMSEA = .064, 90% CI [.057, .071], SRMR = .041. Exploratory network analyses yielded 4-factor solutions distinguishing boundaries between PTSD, disturbance in self-organization (DSO), depression, and anxiety. Collectively, these findings call for systemic efforts to help increase access to well-researched and effective interventions as well as provide suggestions for central symptoms in these networks, and offer practitioners evidence for cPTSD validity and an assessment tool to utilize in Arabic.27 0Item Restricted The Economic Impacts of Geopolitical Risk(2023-01-17) Alsubaie, Mohammed; Ma, XiaohanThe purpose of this dissertation is to investigate the impact of the geopolitical risk shocks on the economy. The first chapter of this dissertation investigates how the geopolitical risk could affect macroeconomic variables of the United States. The second chapter studies the impact of the geopolitical risk on the aggregate and sectoral US employment. The third chapter studies the impact of geopolitical risk with various uncertainty proxies on the US economy.13 0