Browsing by Author "Almutairi, Abdulaziz"

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Effect of Covid 19 on Cyberspace
(Saudi Digital Library, 2023-10-01) Almutairi, Abdulaziz; Adda, Mo
In addition to altering the world's physical appearance, the COVID-19 epidemic has hastened the world's transition to a fully digital society. With an emphasis on remote work, online education, and electronic communication, this thesis explores the far-reaching effects of the pandemic on global technology use, cybersecurity threats, and government policy. This study used a mixed-methods strategy to investigate these effects in depth. A comprehensive international survey was carried out to collect information from people, organisations, and governments in many parts of the world. The results show that people have shifted dramatically towards remote employment, online schooling, and virtual communication due to the pandemic. Cybersecurity challenges, such as increased cyber-attacks, data breaches, and vulnerabilities associated with remote work settings, have increased with digital transformation. To variable degrees of effectiveness, governments and organisations have made steps to reduce these dangers. The research provides guidelines for improving cybersecurity, including risk assessments, developing incident response plans, providing enough employee training, and using cutting-edge technology like artificial intelligence and blockchain.
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MACROPHAGE IPLA2β-DERIVED LIPID SIGNALING CONTRIBUTES TO TYPE 1 DIABETES DEVELOPMENT
(Saudi Digital Library, 2023-05-23) Almutairi, Abdulaziz; Ramanadham, Sasanka
Type 1 Diabetes (T1D) is an autoimmune disease characterized by the destruction of insulin-secreting pancreatic β-cells that leads to hyperglycemia; however, the mechanism of β-cells destruction remains elusive. Ca2+-independent phospholipase A2β (iPLA2β), which hydrolyzes membrane phospholipids at the sn-2 position and releases bioactive lipids, modulates polarization of macrophages (M0). Data from our lab suggests that selective iPLA2β-derived lipid signals (iDLs) (i.e., PGs, HETEs, DHETs, LTB4) produced by M0 from spontaneous-T1D prone nonobese diabetic mice (NOD) are high during the pre-diabetic phase. However, the impact of macrophage-derived iDLs in T1D remains unclear. Therefore, we generated a NOD mouse model with a conditional reduction in macrophage iPLA2β, cHET, and cKO mice, to examine the roles of macrophage-iDLs on T1D development. We show that reduction of iPLA2β in macrophages can inhibit macrophage proinflammatory polarization (M1) and reduces production of select proinflammatory iDLs (PGs, DHETs, and TXB2) during the disease stage (14 weeks of age). Furthermore, selective inhibition of DHET production or PGE2 signaling diminish NOD macrophage polarization towards an M1 proinflammatory phenotype. We expand on these findings to show how modulation of macrophage-iPLA2β selectively protects from T1D development. We show cHET and cKO mice have conferred significantly reduced pancreatic immune cell infiltration, reduced diabetes incidence and improved glucose homeostasis. Moreover, pancreata of cHET and cKO NOD mice exhibited increased anti-inflammatory (M2) macrophage and less TNF+CD4+ and TNF+CD8+ T cells suggesting that reduction of macrophage-iPLA2β can halt an ongoing autoimmune disease process. The conclusions from this work provide a direction for the modulation of macrophage-iPLA2β expression and macrophage-derived iDLs to counter T1D development.
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Van der Waals Heterostructures and 2D Materials with Native Oxide for Emerging Electronic Applications
(University of Cambridge, 2023-12-30) Almutairi, Abdulaziz; Hofmann, Stephan
The rapid advancement of Artificial Intelligence (AI) and Machine Learning (ML) in various industries has created a significant energy demand. However, this demand poses a challenge as the world strives to shift towards sustainable energy sources. The current computational paradigms, reliant on complementary metal-oxide-semiconductor (CMOS) transistors, are becoming more inadequate for meeting these emerging demands due to limitations imposed by materials characteristics and device architecture. To address this computational paradigm shift, an innovative material platform is necessary. Two-dimensional (2D) layered materials and their heterostructures offer a promising solution to meet this demand, owing to their unique properties. In addition, oxidation processes of 2D materials, which are termed "morphotaxy", allow for precise control over the material thickness and the fabrication of complex heterostructures, opening the door for advanced computing architectures such as non-von Neumann neuromorphic computing. This thesis explores the critical role of interfaces in the performance and efficiency of devices based on 2D materials van der Waals (vdW) and semiconductor/native oxide heterostructures. The susceptibility of these materials to contamination is highlighted, especially in vdW heterostructures. Elemental analysis of chemical species present at the interfaces of hBN-encapsulated graphene is conducted to determine the origin of contaminants. The findings highlighted the difference between contaminants originating from the heterostructure stacking process and the ones from the device lithography process. Moreover, the impact of such interfaces on carrier transport across two 2D materials and the realisation of phenomena like moiré superlattices in vdW heterostructures based on twisted WSe2/MoS2 hetero-bilayer is discussed. The results showed that inhomogeneity across the heterostructure interface brought by strain and contamination has an impact on the formation of the interlayer exciton (ILX) by reducing the hybridisation of the electronic states between the two 2D layers. In addition, the interface between the semiconductor and oxide in oxidised HfS2 and GaS is probed using complementary characterisation techniques. The results clearly demonstrate the role of the oxidation method on the crystallinity, thickness and uniformity of the produced oxide. This level of control facilitated the production of highly uniform ultrathin oxide layers on top of their corresponding 2D semiconductor materials, which are used for the first demonstration of low-energy resistive switching.
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