United Arab Emirates University
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CHARACTERISTICS OF LACTOBACILLUS HELVETICUS FERMENTATION OF CAMEL AND BOVINE MILKS
Get PDFIn this study, the fermentation of low-fat camel milk (CM) and bovine milk (BM) with Lactobacillus helveticus was compared to fermentation with L. delbrueckii subsp. bulgaricus, and S. thermophilus at 28°C, 35°C, and 42°C. The fermentation activities were followed by measuring bacterial counts, titratable acidity, pH, and changes in lactose, organic acids, and proteolysis for 96 hours. Although bacterial growth was comparable in CM and BM, the fermented milks showed differences in acidification and proteolysis. Negative correlations between TA (%) and pH were consistent in both CM and BM suggesting similar buffering capacities. In both milks, L. helveticus behavior was more comparable to S. thermophilus than L. delbrueckii subsp. bulgaricus. These findings provide valuable insights into the dynamics of L. helveticus offering possibilities for alternative fermentation processes in dairy product production
VISUALIZING PRIVATELY PROTECTED DATA: EXPLORING THE PRIVACY-UTILITY TRADE-OFFS
Get PDFIn a data-driven era, achieving a balance between privacy and utility is crucial. Organizations often utilize data for research, analysis, and enhancement of services, which emphasizes the significance of effective privacy-preserving techniques to protect individuals\u27 privacy and comply with regulations. This equilibrium is vital in data visualization to derive insightful decisions from data representations. The goal is to evaluate the trade-off between privacy preservation and data utility, understanding how differentially private parameters impact effective visualizations. Valuable insights will guide strategies for achieving optimal privacy-preserving visualization techniques. The study aims to investigate the effects on privacy and data utility in different privacy settings and identify the ideal trade-off between privacy protection and data usability. Differential privacy techniques are used to obfuscate sensitive data, relying on data sensitivity and varied epsilon values to achieve different privacy levels. The impact on data utility is analyzed using histograms, which show data frequency and distribution. These graphic aids visualized the compromises that must be made between protecting privacy and guaranteeing data usability. Our analysis highlights the vital role of visual analytics in balancing privacy protection and data utility. We present a hybrid multi-objective metric in our study that comprehensively assesses the trade-offs between privacy and utility. This novel contribution helps to develop strategies that maximize data utility and privacy protection by offering a more nuanced understanding of how privacy-preserving techniques affect data visualization. Additionally, we design an evaluation model using both empirical and estimated experiments that provide practical privacy parameters adapted for real-world scenarios. This dual-method approach offers useful techniques for protecting privacy in data visualization and determining the best trade-off, which fills a void in the existing literature. This contribution to the field delivers valuable insights to best optimize privacy-preserving techniques for data visualization
THE EFFECT OF NUCIFERINE ON THE RENAL DYSFUNCTION FOLLOWING ISCHEMIA/REPERFUSION INJURY
Get PDFRenal Ischemia-Reperfusion Injury (IRI) is an inevitable consequence of some surgical procedures and clinical conditions such as renal transplantation and aortic cross-clamping. The pathophysiology of renal IRI includes oxidative stress, an aggravated inflammatory response, apoptotic cell death, and fibrogenesis. These pathophysiological processes underlying renal IRI lead to the development of Acute Kidney Injury (AKI). Therefore, there is a need for effective and affordable therapeutic agents, such as phytochemical compounds to mitigate this injury. Nuciferine (NF), is a phytochemical compound extracted from the plant Nelumbo nucifera Gaertn and has been selected for its antioxidant and anti-inflammatory properties as demonstrated in the literature. Therefore, this study aimed to investigate the effects of NF on renal IRI-induced renal dysfunction. Rats were divided into three groups: G-Sham (n=12), G-IRI (n=12), and GIRI/NF (n=12). The G-IRI and G-IRI/NF groups underwent warm renal ischemia through bilateral ligation of the right and left renal arteries for 35 min, with one receiving vehicle and the other receiving 30 mg/kg NF treatment, respectively. G-Sham underwent sham surgery and received only vehicle. Major renal functional parameters, including serum creatinine, Blood Urea Nitrogen (BUN), creatinine clearance, and Albumin Creatinine Ratio (ACR) were measured to evaluate kidney function. Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) and western blot analysis of key oxidative stress, inflammation, cell death and survival, and fibrotic markers, and histological analysis were performed. Our results demonstrated that NF did not affect basal kidney function compared with the pre-IRI samples. NF significantly attenuated the alterations in serum creatinine (0.38±0.03 vs. 0.68±0.13), creatinine clearance (1.32±0.10 vs. 0.85±0.12), ACR (139.86±13.62 vs. 208.81±25.47) when comparing G-IRI/NF to G-IRI groups (p\u3c0.05 for all). NF also significantly attenuated alterations in markers of renal injury, pro-inflammatory cytokines, pro-fibrotic and apoptotic factors, and histological changes. For instance, the gene expression of Neutrophil Gelatinase-Associated Lipocalin (NGAL) and Kidney Injury Molecule-1 (KIM-1) in the G-IRI/NF and G-IRI were (13.86±1.51 vs. 17.91±0.63) and (296.16±73.59 vs. 590.03±36.79), respectively (p\u3c0.05 for both). Moreover, western blot analysis revealed that NF significantly reduced the expression and activation of NF- kB transcription factor and cleaved caspase-3, both of which were increased following renal IRI. Additionally, NF significantly reversed the IRI-induced reduction in the autophagic marker LC3II/LC3I ratio. Therefore, NF has demonstrated antiinflammatory, anti-apoptotic, and anti-fibrotic properties in renal IRI, which is reflected in the partial recovery of major renal functional parameters and histological features. This study presents, for the first time, the therapeutic potential of NF in renal IRI and this might have clinical implications
LOCALLY TAILORED KNOWLEDGE, ATTITUDE AND PRACTICE TOWARDS DIET SUSTAINABILITY QUESTIONNAIRE: VALIDATION AMONG UAEU ADULTS
Get PDFFood production is a major contributor to global environmental change and sustainability. Sustainable diets can be defined as “diets with low environmental impacts which contribute to food and nutrition security and healthy life for present and future generations”. The United Arab Emirates (UAE) aims to enhance its food security to meet the current local demand and future needs of an increasing population. Before determining a sustainable diet pattern for the UAE population, it is foremost more important to understand the perception of sustainable diet production and consumption. A thorough comprehension of the knowledge, attitudes, and practices of the United Arab Emirates population is crucial for the development of targeted programs aimed at promoting sustainable diets. To the best of our knowledge, no detailed validated questionnaire that measures the attitudes and behaviors toward sustainable diet production/ consumption exists as these tools are vital in analyzing the gap between current practice and optimal practice and determining future trends. The aim of the study is to design and validate adapted tools and to assess the Knowledge, Attitude, and Practice (KAP) of adults toward adopting a sustainable diet in the United Arab Emirates population. A cross-sectional study has been conducted at UAEU in 2023. The study was conducted over two phases. Phase 1 was about generating the items, designing the questionnaire, and pilot testing of the questionnaire on a smaller group of participants (N= 86) by using Kaiser-Meyer-Olkin’s (KMO), Bartlett\u27s Tests, Cronbach’s α, Confirmatory Factorial Analysis, and Fit Indices. In phase 2, the same tests mentioned earlier in phase 1 were used beside item-to-total correlation to validate the questionnaire on a larger group of participants. Reliability was assessed in phase 2 and test-retest reliability was done by using the Mann-Whitney test, Bland-Altman Analysis, and Cronbach α. Knowledge, attitude, and practice toward diet sustainability have been assessed by using a questionnaire that has been tailored from existing English questionnaires. It was filled online by 389 participants from the UAEU. Sociodemographic data were collected including age, gender, BMI, employment status, educational level, income, nationality, marital status, family size, diet counseling, nutrition education, and nutrition knowledge. The questionnaire was administered twice to the participants with a one-month interval between two administrations for reliability assessment purposes. In phase 1, construct validity was done for pilot testing of 86 participants as a pre-test administration with satisfied KMO ranged between 0.720 and 0.852, and Bartlett\u27s tests of sphericity were statistically significant. All factorial weights in phase 1 were beyond 0.5, and acceptable association between the items and the factor except in domain D which led to item modifications. Internal consistency for 86 participants was acceptable and satisfied by measuring Cronbach’s α. In phase 2, 389 questionnaires were collected from adults (80.70% female) aged 25.0 ± 9.7 on average. Factor analysis revealed that the three-factor model had moderate fit indices. High internal consistencies of Cronbach\u27s α values of 0.900, 0.960, and 0.897 were observed for knowledge, attitude, and practice. Data of test-retest reliability using Bland-Altman Analysis shows the reliability between 2 responses. Results showed that participants had poor knowledge, and practice, with a positive attitude toward food sustainability Significant correlations between domain response and all sociodemographic characteristics (P-value ≤ 0.05) were found, except BMI (kg/ m2) with knowledge domain. The questionnaire of the present study is reliable, valid, and can be used as the best tool compared to others for the UAE adult population. Moreover, reliable data preferably from validated present questionnaire will be needed to develop interventions, awareness campaigns, and programs accordingly in the future
DEVELOPMENT OF A NON-INTRUSIVE LOAD MONITORING TECHNIQUE USING PHASE-SPACE-RECONSTRUCTION AND 2-D FOURIER SERIES CURRENT WAVEFORM FEATURES
Get PDFThe growing need for energy and efficient energy control has emphasized the importance of tracking appliance-level energy usage. The capability of Non-Intrusive Load Monitoring (NILM) to separate energy usage data per appliance from a single measurement provides a practical solution. This thesis explores developing a novel NILM method using Phase-Space Reconstruction (PSR) and 2-D Fourier Series to enhance feature extraction from the steady-state current waveforms. Existing NILM techniques frequently encounter accuracy challenges caused by overlapping power signatures of appliances and complex operational states. The proposed method is designed to efficiently capture the steady-state characteristics of electrical appliances. It is evaluated on the COOLL dataset, which includes high resolution current and voltage measurements for a variety of appliances, using basic machine learning algorithms like K-Nearest Neighbors (KNN) and Decision Trees (DT). The findings show that the use of a combination of PSR and 2-D Fourier series to extract appliances features has enhanced the classification accuracy, achieving a peak of 99.88% when the number of harmonics and the time delay for PSR are optimal. The results suggest that a relatively large time delay produces best representation for the current waveforms and the initial few harmonics are sufficient to efficiently capture load signatures. Future studies should explore the method using various datasets, apply feature selection techniques to reduce dimensionality and implement a real-time system to confirm the method effectiveness
المعايير العالمية المشتركة لتقييم جودة البيئة السكنية
Get PDFتعمل الحكومات على تحسين جودة الحياة لمواطنيها من خلال مشاريعها وبرامجها التنموية. حيث يُعنى برنامج جودة الحياة، كجزء من برامج دعم تحقيق رؤية المملكة العربية السعودية ٢٠٣٠، بتحسين جودة حياة أفراد المجتمع. في حين يتطلب تحسين جودة الحياة العمل على تعزيز مجالات الحياة المختلفة والبيئة المحيطة. ومن هنا، تحتل جودة البيئة المبنية أهمية محورية، خاصةً في البيئة السكنية التي تُشكّل الجزء الأكبر من النسيج العمراني.
إن تلبية الطلب المتزايد على الإسكان بجودة تساهم في تحقيق أهداف رؤية ٢٠٣٠ وبالسرعة المطلوبة يستدعي وضع معايير سعودية لتقييم جودة البيئة السكنية. هذه المعايير ستكون مرجعًا لكافة مراحل التصميم، والمراجعة، والتقييم. ولكن استنباط هذه المعايير، يستدعي الاطلاع على المعايير العالمية لتقييم جودة البيئة السكنية وتحديد المستويات المشتركة بينها، لتكوين أساس مرجعي يمكن الرجوع له لاحقًا لتطوير معايير محلية خاصة بالمملكة.
ركزت هذه الدراسة على استقصاء المعايير العالمية لتقييم جودة البيئة السكنية وتحديد المستويات المشتركة بينها، من خلال منهجية بحثية مكونة من خمس مراحل. بدأت بمراجعة منهجية للأدبيات العالمية ذات الصلة، وجمع المصادر التي تناولت موضوع جودة البيئة السكنية. تم تحليل وتقييم ملخصات هذه المصادر لاختيار تلك التي تركز على تقييم جودة البيئة السكنية. تلا ذلك تقييم متعمق لمحتوى المراجع المختارة وتحديد المعايير المتعلقة بجودة البيئة السكنية، ثم استخلاص المعايير المشتركة منها. في النهاية، تم التوصل إلى قائمة تضم ثمانية وثلاثين معيارًا عالميًا لجودة المسكن، مصنفة تحت سبعة محاور رئيسية، مع المؤشرات وأدوات القياس ونطاق التطبيق.
تمثل نتائج هذه الدراسة الخطوة الأولى نحو تطوير معايير لتقييم جودة البيئة السكنية في المملكة العربية السعودية. وتؤكد الدراسة على أهمية مراعاة السياق السعودي والاعتبارات الثقافية والاجتماعية عند تطوير المعايير، لضمان تحسين البيئة السكنية وتعزيز جودة الحياة بما يتماشى مع الأهداف الاستراتيجية لرؤية المملكة ٢٠٣٠
DYNAMIC RESOURCE ALLOCATION FOR BEYOND 5G NETWORKS THROUGH UAV-ASSISTED COMMUNICATION
Get PDFIn response to the surging demand for cellular services, driven partly by the post-COVID-19 era, network operators are grappling with the challenge of enhancing network capacity and throughput. Fifth-generation mobile technology and beyond (6G) with techniques like network slicing are emerging as promising solutions for faster data speeds and improved network performance across various devices. In network slicing, distributing radio resources between different virtual operators (slices) is often performed in a static manner. Therefore, due to the dynamic user demand, the users of one virtual operator could suffer from a lack of resources, whereas another virtual operator with overlapping cells is underutilized. The research of this thesis addresses the dynamic resource allocation between the two virtual operators (slices) with the aid of aerial base stations (UAVs). The proposed algorithm harnesses reinforcement learning to find the optimal placement of the aerial base station to maximize the network users’ throughput. This enables UAVs to dynamically manage radio resources by serving the users of the underutilized slice while offloading some of the users of the heavily utilized slice to the ground cells of the underutilized slice. Comprehensive tests, using both single-UAV and dual-agent UAVs on a grid of overlapping cells, evaluated average user throughput, the percentage of satisfied users (with improved throughput), and throughput enhancement for satisfied users. Different offloading strategies are examined based on the number of offloaded users, their locations, and the capability of their user equipment (numerology). One of the main findings of this research is that offloading a certain percentage of the users in a heavily utilized slice cell based on their locations leads to a significantly improved user throughput
DISTURBANCE OBSERVER-BASED CONTROL SCHEMES FOR OFF-GRID RENEWABLE ENERGY-BASED DISTRIBUTED GENERATION SYSTEMS FEEDING UNBALANCED AND NONLINEAR LOADS
Get PDFThis thesis addresses two critical issues in Renewable Energy-based Distributed Generation (REDG) systems that operate autonomously to supply unbalanced and nonlinear loads. The first issue concerns voltage regulation in grid-forming three-phase Pulse Width Modulation Voltage Source Inverters (PWM VSIs), which convert DC power generated by Distributed Generators (DGs) into three-phase AC power. These inverters often face challenges when feeding unbalanced and nonlinear loads, leading to poor voltage quality. To address this, a voltage controller was developed for grid-forming three-phase PWM VSIs to deliver symmetrical and high-quality voltage to such loads. The proposed controller integrates a Disturbance Observer (DO) into a state feedback controller designed using the Feedback Linearization (FL) framework to address a range of disturbances, including non-oscillatory disturbances and oscillatory disturbances that represent the harmonic oscillations induced by unbalanced and nonlinear loads. The controller’s steady-state and transient responses were verified through simulation and experimentation, with a comparative analysis conducted against a conventional cascaded PI control scheme. The findings demonstrate the controller’s capability to accurately track the reference voltage while complying with IEEE voltage quality standards under the tested conditions. The second issue addressed in this thesis is the occurrence of Double Fundamental Frequency Oscillations (DFFO) in the voltage across the DC link, particularly when unbalanced AC loads are connected to the system. These oscillations, which circulate in the DC link capacitor as a result of feeding unbalanced AC loads, can lead to the degradation of the capacitor at the DC link and subsequently a reduction in its lifespan. To mitigate these oscillations, an energy storage (ES)-based compensation strategy was developed. This strategy is executed by incorporating a Disturbance Observer (DO)-based control scheme to operate the interfacing DC-DC converter of the ES. This control scheme enables the ES to effectively compensate for DFFO in the DC link voltage while maintaining its power balancing function. The effectiveness of this strategy was evaluated through a comparative study with a conventional control scheme that cannot compensate for the DFFO, under various operating modes and transient conditions. The results demonstrated that the proposed strategy effectively mitigates DFFO, leading to a stable and smooth DC link voltage under the tested conditions. Additionally, the strategy reduced the need for large DC link capacitors, which are typically used to dampen the DFFO. The research findings highlight the importance of advanced control schemes for power electronic converters (PECs) in ensuring the reliable performance of REDG systems when supplying loads that present unbalance and nonlinearity. Moreover, the integration of disturbance observer techniques into control strategies significantly enhances controller performance under loads that draw unbalanced and distorted currents and improves response to load transients. Furthermore, these control strategies can also help eliminate the need for larger circuit components that are typically required to mitigate the oscillations within the system. The proposed solutions contribute to the optimization of REDG systems, ensuring stable and efficient operation under diverse load conditions. A broader consequence of these developments is the enhanced reliability and efficiency of REDG systems, facilitating their seamless integration into power networks and significantly advancing the development and deployment of renewable energy technologies
PHENOLIC COMPOUNDS IN DATE FRUITS (Phoenix dactylifera L.)
Get PDFThis study investigated the phenolic compounds in date fruits, mainly soluble and hydrolyzable compounds, and insoluble melanin. Soluble (27.5–54.0 mg/100 g FW) and hydrolyzable (24.0–78.5 mg/100g FW) phenolic compounds were determined in 18 cultivars using ultra-performance liquid chromatography coupled with mass spectrometry. Phenolic acids were predominant in both fractions while flavonoids were mainly present in the soluble phenolic fraction and the proanthocyanidin B1 and B2 were only present in the hydrolyzable fraction. Four total antioxidant activity assays (total phenolic content, ABTS, FRAP, and DPPH) gave different results for both the soluble and hydrolysable fractions of 26 date fruit cultivars, which questions the reliability of these assays. Date fruits contained high levels of insoluble allomelanin (1.2–5.1 g/100 g FW). Electron paramagnetic and nuclear magnetic resonance coupled with computational density functional theory suggested that the date fruits melanin is based on (-) -epicatechin stacked oligomers. Overall, this study provides new insights into the phenolic compounds present in date fruits, particularly hydrolyzable phenolic compounds and melanin
Comparison the impact of CO2 and UVB on Moringa peregrina and Moringa Oleifera growth under Open Top Chamber
Get PDFClimate change has caused a tremendous impact on ecosystems, with an apparent connection between farming methods and environmental changes. Climate change has a substantial effect on both abiotic factors and biotic issues affecting crop plants. The increasing number of abiotic stresses has highlighted the impact of global warming on plant productivity. This study compared and evaluated the abiotic stress resistance of two Moringa species (Moringa oleifera and Moringa peregrina) against UV radiation, increased CO₂ levels, and their combined effects. The evaluation mainly focused on key morphological features, including plant height (cm) and fresh and dry weights, to assess the species responses to various environmental stresses. The results revealed that Moringa oleifera showed better growth performance compared with Moringa peregrina under CO₂ and UVB stress conditions. Furthermore, Moringa oleifera presented higher values of chlorophyll and carotenoids, allowing for more efficient photosynthesis and protection against oxidative stress