Browsing by Author "Aljohani, Alaa"

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Economic Growth and Tourism Trends and Dynamics in Saudi Arabia: A Time Series Perspective
(Saudi Digital Library, 2023-08-25) Aljohani, Alaa; Potlogea, Andrei
This study employs time-series econometric analysis to explore the trends and dynamics between economic growth and tourism development in Saudi Arabia. The investigation sheds light on the evolving trends and dynamics within this nexus. The findings hold implications for policymakers and researchers seeking to comprehend the interplay between these crucial variables. Through a series of comprehensive analyses, the study reveals significant associations between economic growth and tourism development in Saudi Arabia. The complexities arising from varying cointegration indications prompted an insightful investigation into the subsequent regression analyses. The findings revealed that the incorporation of the first differenced variables led to diminished statistical significance. This observation underlines the need to cautiously interpret initial results, attributing them to spurious results due to cointegration. Thus, the study accentuates the importance of accounting for cointegration effects, with greater emphasis placed on regression outcomes involving first differenced variables. Nonetheless, prudent interpretation of these findings is imperative, taking into account the study's limitations and the intricate spectrum of factors influencing the convoluted relationship between tourism and the economy in the country. Noteworthy among these limitations are data constraints and the dearth of literature that delves into Saudi Arabia's distinct context. Moreover, the study acknowledges the intricate landscape shaped by the nation's historical dependence on oil revenue and the ongoing transformation of its burgeoning tourism sector. Despite these constraints, the research yields invaluable insights that enrich the broader comprehension of the role of tourism in fueling economic growth, particularly in a resource-dependent country like Saudi Arabia. In conclusion, this study emphasises the imperative for Saudi Arabia to harness the potential of tourism diversification in its economic landscape. This strategic shift requires proactive promotion, investment, and the cultivation of sustainable growth across various sectors. By embracing a holistic approach to growth, Saudi Arabia can foster economic resilience, inclusivity, and competitiveness on a global scale. The recommendations put forth underscore the need for comprehensive data collection, collaborative research efforts, and a focus on enhancing the nation's tourism infrastructure to attract a diverse range of tourists. By implementing these suggestions, Saudi Arabia can unlock the transformative potential of tourism as a driving force for economic development and economic diversification.
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Piptedoglycan Dynamics in Bacillus subtilis
(Newcastle University, 2024-09) Aljohani, Alaa; Richard, Daniel
Gram-positive bacterial cell morphology, growth, and division rely on a delicate balance of peptidoglycan synthesis and controlled degradation to maintain the structural integrity of the cell wall. The process of growth involves synthesising new wall material underneath the existing cell wall on the surface of the cell membrane. This growth requires the cell wall degrading enzymes to distinguish between the newly generated wall and the old wall, selectively degrading the outer layers of the wall to facilitate cell enlargement. As the B. subtilis genome encodes 42 genes that are potentially involved in peptidoglycan degradation, systematic deletion of the known autolytic enzymes was used combined with phenotypic analysis for both cell morphological changes and the ability to become motile. From this work, it was found that only 1 of 2 specific autolytic enzymes is functionally required for growth (CwlO and LytE). Although these two autolytic enzymes exhibit a significant degree of functional redundancy, they are required for slightly different aspects of cell morphology. Only CwlO, in concert with CwlQ or CwlS, was also found to be required for the efficient insertion of flagella through the cell wall. Further analysis showed that CwlO activity with respect to cell growth required the activity of a peptidoglycan carboxypeptidase (DacA), but this was not required for flagellar insertion, suggesting that CwlO has two distinct modes of action. In summary, the results of the work presented in this thesis show that the majority of the predicted cell wall degrading enzymes are dispensable, and only 2 enzymes, CwlO and LytE, have critical roles in maintaining normal cell morphology. Interestingly, this study also reveals that the two key autolytic enzymes seem to have distinct modes of action and potentially differ in their substrate specificity. In this respect, a model for cell growth is presented that tries to amalgamate the results of this work with previously published ideas to explain how cell growth is coordinated with respect to peptidoglycan synthesis and degradation without compromising cell integrity and maintaining cell morphology. This model potentially outlines the basic mechanism of cell wall metabolism in Gram-positive rod-shaped bacteria. It also seems that aspects of the mechanism are also conserved in other bacterial species with a different cell morphology as well as in Gram-negative bacteria. These results clearly indicate that the autolytic enzymes and their regulatory mechanisms are potentially interesting novel targets for the development of small molecule antibacterial compounds.
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