SACM - United Kingdom
Permanent URI for this collectionhttps://drepo.sdl.edu.sa/handle/20.500.14154/9667
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Item Restricted 1 Evaluation of the expression of microRNAs, with an emphasis on microRNA-155 and miR-155*, in the serum of patients post haematopoietic stem cell transplantation and their association with acute graft versus host disease.(Saudi Digital Library) Osama Ali M Alsuraihi; Prof. Anne Dickinson102 0Item Restricted 1 PREDICTION OF SOLAR IRRADIANCE FROM WEATHER DATA USING MACHINE LEARNINGJOMANAH ALI ABDULAZIZ ALHAMIDI; Dr Alessandro CheccoA main aim of this study is to predict solar irradiance as solar power generation metrics. In order to do that, multiple machine learning algorithms are applied to data collected from a network of solar and wind resource monitoring stations and weather data in Saudi Arabia18 0Item Restricted 1 THE DEVELOPMENT OF ENGLISH VOCABULARY AMONG SAUDI TWITTER USERSSALWA NASSER JUBRAN HURAYSI; Dr.Ruth PageTwitter is a prominent micro-blogging platform among Saudi people, which indicates that Saudi users are now constantly engaged with thousands of native English speakers as well as other English as foreign language students and teachers. This research sheds light on the use of Twitter by Saudi users to determine their improvement of English vocabulary. The study examined how participants’ social interactions on Twitter can support second language vocabulary learning as well as the factors that influenced their decision to use Twitter to enhance their second language learning. The purpose of this research is to examine how Saudi users have adapted to Twitter and how they use it as an English language learning tool. As a theoretical framework, the researcher employed Vygotsky’s socio-cultural theory and zone of proximal development model, according to which when a learner is in the zone of proximal development for a specific assignment, offering the necessary support provides enough of a “boost” for the learner to complete the task independently via social interaction. To this end, 63 Saudi Twitter users with various levels of education were selected. Their ages ranged from 18–40 years old, and they were all likely to be of Arab descent. Based on a mixed-method approach, the data were collected through survey questionnaires. This mixed-methods study, which included survey questionnaires, examined the use of Twitter for educational reasons, with a focus on improving English vocabulary. An open and close-ended survey questionnaire was used to collect quantitative data from the selected sample. Survey questionnaire consisted of three parts. The first part addressed the demographic information, such as age, academic ranking, years of exposure to the English language, and study level of the participants. The second subsection consisted of open-ended questions to acquire in-depth, detailed data about the users’ perceptions of their English learning experiences using Twitter. The third subsection consisted of five Likert scale questions to investigate if they learned new vocabulary by Twitter, if they were confident in using English on Twitter, and if Twitter helped them to increase their knowledge of English vocabulary. The perceived attributes of Twitter were evaluated using a five-point Likert-type scale ranging from strongly agree to strongly disagree. The results revealed that Twitter had a positive impact, improving English vocabulary by 82.5% in. Twitter motivated users to communicate confidently with native speakers, with 63% scored in total. These findings can be expanded by more experimental research to assess how Twitter can be successfully used as a teaching tool in English language learning classrooms in Saudi Arabia and other countries. The findings suggest that Twitter and other social networking sites can be used as English language learning tools. Several implications and suggestions for teachers, policy makers, and scholars are discussed.37 0Item Restricted 1+1 Numerical Relativity: The Gravitational Collapse of a Massless Scalar FieldRAWAN SAUD SULTAN ALRAYES; Dr Eugene LimThis paper numerically solves the Einstein’s field equations in the 1+1D formalism for a spherically symmetric massless scalar field with a Gaussian configuration. The initial amplitude of the scalar field is varied to find that with an initial value of φ0 = 0.001 no collapse occurs, while for the case of φ0 = 0.002 the field collapses into a black hole.13 0Item Restricted 1. Which opportunities provided by cryptocurrencies are relevant for regulatory bodies? 2. What are the threats and barriers to the regulation of cryptocurrencies based on their inherent characteristics?(Saudi Digital Library) DIMA KHALID ALEIDI; James Cullen9 0Item Restricted 100% RENEWABLES BY 2020 IN SCOTLANDOSAMA MUSAED ALGHAMDI; neil wightAccording to the Scottish government and enforcing the climate act 2009. The Scottish government aims to rely on renewable resources 100% by 2020. This statement clarifies its target by stating the government aim to produce their electricity demand via renewable resources. But in this assignment that might not be possible due to the intermittency of the renewable resources.8 0Item Restricted 1D MODEL FOR FLOWIN THE PULMONARY AIRWAY SYSTEM(Saudi Digital Library) Eyman Salem Alahmadi1 0Item Restricted 1H-NMR based metabolomics and HPTLC for quality control of Panax ginseng extracts(Saudi Digital Library) ALAA ABDULLAH KHOJAH; Michael Heinrich27 0Item Restricted 2-HYDROXYBENZOATE ANALOGUE MEDIATED APOPTOSIS IN HUMAN HT-1080 FIBROSARCOMA CELLS(Saudi Digital Library) MOHAMMED ALKARRAWI1 0Item Restricted 201 Thallium cardiac stress studies in the assessment of laser transmyocardial revascularization (TMR) (M.Sc.)(Saudi Digital Library) HIJJI AL-SAKHARI0 0Item Restricted 20183623_A CASE STUDY OF THE RESPONSE OF SAUDI GOVERNMENT TO COVID-19SALEH OTHMAN KHUDHAIR; Dr Jamie WardmanThis qualitative case study explores the implication of Covid-19 on Saudi Arabia and the response of Saudi government to the pandemic. Majority of the existing research focuses more on the initiatives taken by different countries to fight against the spread of Covid-19, leaving a research gap on the implications of the protective and preventive measures taken by different countries. This research utilized a case study research design due to its ability to collect solid and in-depth understanding about a particular real-world phenomenon, which allows exploration of the main attributes and effects of the case. The research established that Saudi Arabia government had Covid-19 under surveillance since its outbreak and measures were put in place in preparation for the imminent entry in the country. These plans included social, economic, and healthcare measures. Social distancing measures were given preference due to their potential role in increasing transmissions. These bold measures were enforced in the best interest of the public health regardless of its potential for negative economic and social implications. The study established that the outbreak of Covid-19 was associated with a number of economic implications, both positive and negative, in Saudi Arabia as well as the rest of the world. The study recommends that more investment should be channeled into technology, as it played a crucial role in controlling infections, but is largely under-utilized. Technology can improve the efficiency of well-run government operations. Technology should be part of the overall plan of the government since it is based on thorough planning and preparation of several activities. Keywords: Economic implications, Covid-19 pandemic, protective and preventive measures, qualitative case study,13 0Item Restricted 2020 Technology Roadmap of solid-state Terahertz source device technologiesKHALID ABDULLAH KHALID ALMULHIM; Khalid AtaThe aim of this thesis is to review the Radio Frequency (RF) sources leading to Terahertz source technologies that operate at room temperature and are based on solid-state devices technologies and have light weight and mass manufactureable for growing wireless technologies such as 5G and beyond. This review study has enabled us to predict a 2020 roadmap to predict the future development and progress that is anticipated in terms of these source technologies to estimate the output power frequency capabilities these sources. We have identified three such source technologies and they are planar Gunn diode, Impact ionization avalanche Transit-Time diode (IMPATT) diode and resonant tunnelling diode (RTD). We find two remarkable trends for planar Gunn diode and Resonant Tunnelling Diodes. The planar Gunn diode is predicted to reach an output RF power of 110dBm & 1THz fundamental mode of operation by 2040 compared to current state of the art performance of -5dBm and 300GHz frequency of oscillations. In case of RDT a remarkable frequency of oscillations of 5.2THz and output power of 9.7dBm by 2040 from current state of the art performance of 1.9THz and 0dBm output power. This means without some significant breakthroughs the future researcher will find powerful RF sources for 5G and 6G technologies. Although there are other Terahertz solid-state sources able to produce higher output power such as THz quantum cascade lasers (QCLs), vacuum tube based sources. However, they are bulky, some needs cryogenic cooling and some are not mass producible and most of all they are expensive to use in commercial applications. The program of this research was in collaboration with the Cranfield University.4 0Item Restricted 24% Risk(University College of London, 2024) Alomayri, Hanan; Sandys-Winsch, LucyA Saudi filmmaker studying in London receives the news that her young cousin has been diagnosed with type 1 diabetes, a condition that is prevalent in her family. Concerned for her own health, she becomes determined to minimize her risk of developing diabetes. In a short documentary 24% Risk, she shares the proactive steps she takes to achieve this goal.5 0Item Restricted 24-Hour Movement Guidelines and Cardiorespiratory Fitness in Relation to Cardiovascular Disease Risk Factors in Adolescents from Saudi Arabia(University of Exeter, 2022) Alkhraiji, Mohummed Hamad; Williams, Craig A; Barker, Alan RPhysical activity in the form of moderate-to-vigorous physical activity (MVPA), sedentary behaviour in the form of recreational screen time (ST), and sleep, are individually associated with cardiovascular disease (CVD) risk factors in adolescents. Commonly, researchers investigate these three movement behaviours in relation to CVD risk factors in isolation. However, after the launch of the Canadian 24-Hour Movement Guidelines for children and youth, there have been calls to integrate all three 24-hour behaviours (PA, ST, & sleep). Furthermore, a scientific statement from the American Heart Association highlights the importance of cardiorespiratory fitness (CRF) as a measurement for health screening in children and adolescents as CRF is a strong predictor of CVD risk. Previous studies have individually explored how the 24-hour movement guidelines or CRF are associated with CVD risk factors in adolescents; however, which of the two (24-hour movement guidelines or CRF) is more strongly associated with CVD risk factors in adolescents is unknown. Currently, most studies have been conducted in North America and Europe, with the Middle East neglected, including Saudi Arabia, which has a very different lifestyle, environment, climate, school system, and culture compared to North America and Europe. Therefore, to address this gap in the literature in the context of Saudi Arabia, the studies included in this thesis aimed to investigate the prevalence of 24-hour movement guidelines and CRF and their relationship with CVD risk factors in adolescents from Saudi Arabia aged 12–15 years old. Chapter 4 narratively reviewed movement guidelines and CRF in relation to CVD risk factors in children and adolescents from the Gulf Cooperation Council Countries, which indicated gaps in the literature investigating the 24-hour movement guidelines. In addition, Chapter 4 highlighted that there is poor evidence for an association between single movement guidelines and CRF with multiple CVD risk factors; most studies have only examined associations with weight status. Chapter 5 examined the reliability and validity of using the Global School-Based Student Health Survey (GSHS) to assess the 24-hour movement guidelines in (n = 120; 50% females) adolescents aged 12–15 years old, from Saudi Arabia and found acceptable reliability and validity. In Chapter 6, the GSHS was used to examine the prevalence of the 24-hour movement guidelines and their associations with overweight/obesity in a sample of (n = 4224; 52% females) participants aged 12–15 years old. The results indicated that only 2.7% achieved the recommended 24-hour movement guidelines and highlighted weak, non-significant associations with the risk of overweight/obesity. In Chapter 7 a subsample of (n = 120; 50% females) participants aged 12–15 years old from the study in Chapter 6 underwent a 24-hour movement guidelines assessment using GENEActiv accelerometers (for MVPA and sleep) and the GSHS (for ST). In addition, CRF was assessed using the Progressive Aerobic Cardiovascular Endurance Run test, and fasting blood samples, blood pressure, and anthropometrics were collected. None of the adolescents in this subsample met all three of the 24-hour movement guidelines, and there were no favourable significant associations with individual or clustered CVD risk factors. In addition, few males (16%) and almost half of the female (46.3%) participants had a healthy CRF. However, in males only, having a CRF was significantly and negatively associated with waist circumference (WC) and clustered CVD risk. Collectively, the results presented in this PhD thesis contribute to enhancing the literature in four ways. Firstly, it demonstrates that there is a lack of studies on the 24-hour movement guidelines and CRF in relation to CVD risk factors for adolescents from the Gulf Cooperation Council countries. Secondly, it is the first study to examine a questionnaire for its reliability and validity to measure the 24-hour movement guidelines, which found an acceptable reliability and validity. Thirdly, it shows that via a questionnaire few adolescents (2.7%) from Saudi Arabia are meeting the 24-hour movement guidelines, which is not significantly associated with being at risk of overweight/obesity. Lastly, it shows that when using device-based accelerometry, none of the adolescents from Saudi Arabia are meeting the 24-hour movement guidelines, which is not significantly associated with individual or clustered CVD risk factors profiles in both sexes. Moreover, healthy CRF was not significantly associated with individual or clustered CVD risk factors in females, while in males, healthy CRF was only significantly and inversely associated with WC and clustered CVD risk factors. Based on the above findings, it is suggested that 24-hour movement guidelines are not favourable strongly associated with individual or clustered CVD risk factors in adolescents of both sexes from Saudi Arabia. In addition, in females it appears that there are no significant associations between CRF and individual or clustered CVD risk factors. Initiatives should be developed to encourage male adolescents from Saudi Arabia aged 12–15 years old to achieve a healthy CRF to reduce the risk of WC and clustered CVD risk factors. However, future longitudinal studies with larger sample sizes would enable further insight into the associations between 24-hour movement guidelines and CRF in relation to CVD risk factors in adolescents from Saudi Arabia and should provide specific recommendations for both sexes.26 0Item Restricted 3-(N,N-Diacylamino)quinazolin-4(3H)-ones: Preparation, Stereostructure and Application in Kinetic Resolution of Amines Ph.D(Saudi Digital Library) Abdullah Sehemi-Al16 0Item Restricted 3-D Reconstruction by Correlating Uncalibrated Images Phd(Saudi Digital Library) Ali Zahrani - Al0 0Item Restricted 37. Microsoft’s Acquisition of Skype: Value, Strategic Opportunities, and Threats(Saudi Digital Library) Faris Ayed Alharbi0 0Item Restricted 3D Geological Model of the Gullfaks Field Using Petrel(Saudi Digital Library) Mohammed AlQarni2 0Item Restricted 3D Human Activity RecognitionMARYAM ABDULRAHMAN ABDULLAH ALSULAMI; Dr Padraig CorcoranHuman action recognition based on 3D skeleton data has received considerable research attention. Existing methods for modelling skeletons which rely on hand-crafted features or deep learning fail to capture the long-term temporal information and the complex spatial structures which are very important to predict human action. In this work, we applied an existing model called Spatial-Temporal Graph Convolutional Networks (ST-GCN) using a different dataset (NTU-RGB 120).In addition, we apply recent findings in graph neural network (bottleneck problem) by changing the network architecture of ST-GCN(reducing the number of the network layers), and we obtain better recognition performance. We also add a code to compute the confusion matrix to evaluate the performance of ST-GCN. This model tackles the challenges faced by previous methods by automatically learning the spatial and temporal information of the skeleton. Furthermore, this model is the first work that applies Graph Convolutional Networks (GCNs) to model skeleton data as spatiotemporal graphs where nodes correspond to human body joins and edges correspond to connectivity between joints. Experimental results on NTU-RGB 120 dataset shows the effectiveness of the proposed model. We compared the performance of this model with a Two-Stream ST-GCN model, and with a new model with less number of layers.4 0Item Restricted 3D modelling and tissue level of the trapeziometacarapal joint(Saudi Digital Library) YASSER AYISH NASSER ALHARBI; Dr.Qenentine Fogg10 0