Automated Software Testing of Relational Database Schemas

Relational databases are critical for many software systems, holding the most valuable data for organisations. Data engineers build relational databases using schemas to specify the structure of the data within a database and defining integrity constraints. These constraints protect the data's consistency and coherency, leading industry experts to recommend testing them. Since manual schema testing is labour-intensive and error-prone, automated techniques enable the generation of test data. Although these generators are well-established and effective, they use default values and often produce many, long, and similar tests --- this results in decreasing fault detection and increasing regression testing time and testers inspection efforts. It raises the following questions: How effective is the optimised random generator at generating tests and its fault detection compared to prior methods? What factors make tests understandable for testers? How to reduce tests while maintaining effectiveness? How effectively do testers inspect differently reduced tests? To answer these questions, the first contribution of this thesis is to evaluate a new optimised random generator against well-established methods empirically. Secondly, identifying understandability factors of schema tests using a human study. Thirdly, evaluating a novel approach that reduces and merge tests against traditional reduction methods. Finally, studying testers' inspection efforts with differently reduced tests using a human study. The results show that the optimised random method efficiently generates effective tests compared to well-established methods. Testers reported that many NULLs and negative numbers are confusing, and they prefer simple repetition of unimportant values and readable strings. The reduction technique with merging is the most effective at minimising tests and producing efficient tests while maintaining effectiveness compared to traditional methods. The merged tests showed an increase in inspection efficiency with a slight accuracy decrease compared to only reduced tests. Therefore, these techniques and investigations can help practitioners adopt these generators in practice

Instability of non-uniform viscoelastic liquid jets

The industrial prilling process is a common technique to produce small pellets which are generated from the break-up of rotating liquid jets. In many cases the fluids used are molten liquid and/or contain small quantities of polymers and thus typically can be modelled as non-Newtonian liquids. Industrial scale set-ups are costly to run and thus mathematical modelling provides an opportunity to assess methods to improve efficiency and introduce greater levels of precision. In order to understand this process, we consider a mathematical model to capture the essential physics related to a cylindrical drum which is rotated about its axis and from which a slender liquid jet emerges from a hole placed on the side of the drum. Furthermore, surfactants may be used in such process to manipulate the size of the resulting droplets. In this thesis, we model the viscoelastic nature of the fluid using the Oldroyd-B model. An asymptotic approach is used to simplify the governing equations and then we consider a linear temporal stability analysis of the resulting set of equations. The effect of gravity on viscoelastic liquid jets has been discussed both with rotation and without rotation. The trajectory of this problem has been plotted in three dimensions. Our results show the effect of many non-dimensional parameters on the linear instability of a viscoelastic curved liquid with gravity and without gravity

Characterisation of a pair of copper storage proteins from pathogenic bacteria

Ph. D. ThesisNeisseria gonorrhoeae is a pathogenic Gram-negative bacterium that causes human gonorrhoeal disease. Its genome encodes a putative periplasmic homologue of a new family of copper storage proteins (Csp) recently described in methanotrophic bacteria. Although members of this protein family are abundant in pathogenic bacteria, the presence of this periplasmic Csp in N. gonorrhoeae is almost unique. Most Csp genes in pathogenic bacterial genomes lack a signal peptide and are therefore presumed to be cytosolic. For example, the Csp protein encoded in genomes of Salmonella sp. lacks a signal sequence. However, the N. gonorrhoeae Csp possesses a putative Tat signal for targeting it to the periplasm. Salmonella enterica is an important global pathogen, consisting of more than 2500 various serovars that can be host-specific or can have a broad range of hosts, whereas N. gonorrhoeae is highly specialised for infecting humans. Antibiotic resistance in both of these bacteria, N. gonorrhoeae and S. enterica, further enhances their risk to human health. Copper is a redox active metal that is essential for several biological functions as a cofactor used by a number of copper-dependent enzymes. However, excess copper is toxic; thus, its homeostasis is carefully regulated through a system of protein transporters, sensors, trafficking proteins, and storage proteins. The Waldron lab is studying the form and function of these Csp proteins in pathogenic bacteria, as copper is known to play an important role in the innate immune system’s ability to fight infection. It is anticipated that a putative role for N. gonorrhoeae Csp1 and Salmonella Csp3 in defending these pathogens from attack by the immune system would make these proteins potential therapeutic targets for future antibiotics. This study explored the copper binding properties of Csp1 from N. gonorrhoeae and of Csp3 from S. enterica, in order to understand how they may be able to aid virulence, either through sequestration of excess copper, thereby reducing copper toxicity, or by storing copper during times of abundance and subsequent release of copper during copper deficiency. Copper binding by the Csp proteins was assessed, and the crystal structure of Salmonella Csp3 was determined. We concluded that Csps bind a large number of copper ions, likely as a storage mechanism, within a four-helix bundle structure that could be targeted in future drug discovery programmes

The Four-C Framework for High Capacity Ultra-Low Latency in 5G Networks: A Review

Network latency will be a critical performance metric for the Fifth Generation (5G) networks expected to be fully rolled out in 2020 through the IMT-2020 project. The multi-user multiple-input multiple-output (MU-MIMO) technology is a key enabler for the 5G massive connectivity criterion, especially from the massive densification perspective. Naturally, it appears that 5G MU-MIMO will face a daunting task to achieve an end-to-end 1 ms ultra-low latency budget if traditional network set-ups criteria are strictly adhered to. Moreover, 5G latency will have added dimensions of scalability and flexibility compared to prior existing deployed technologies. The scalability dimension caters for meeting rapid demand as new applications evolve. While flexibility complements the scalability dimension by investigating novel non-stacked protocol architecture. The goal of this review paper is to deploy ultra-low latency reduction framework for 5G communications considering flexibility and scalability. The Four (4) C framework consisting of cost, complexity, cross-layer and computing is hereby analyzed and discussed. The Four (4) C framework discusses several emerging new technologies of software defined network (SDN), network function virtualization (NFV) and fog networking. This review paper will contribute significantly towards the future implementation of flexible and high capacity ultra-low latency 5G communications

Occupational pressures and its impact on time consumed in receiving and providing emergency department in Governmental Hospitals at Najran, Saudi Arabia

The study aims to measure Occupational pressures and its impact on time consumed in receiving and providing emergency service in the emergency department of Governmental Hospitals in Najran Region in Saudi Arabia, the study followed Quantitative research methodology, descriptive and analytical research method depending on questionnaire which was applied a sample that consists of (229) physicians, Medical Support Services, nursing staff, and Administration in all public hospitals in Najran Province the study reached results the most important of which there was a high degree of occupational pressures, where the study results indicated that the work environment dimension was in the first rank, followed by the role ambiguity dimension, where are two variables at a high level of estimation. In the third rank there was the career growth dimension, followed by the role burden dimension in the fourth rank. In fifth rank there was the volume of work required dimension, while in last rank there was the difficulty of the work dimension, where these dimensions were at medium level of estimation. The study results showed that there is a statistically significant relationship between (role burden, career growth, work environment) and the time consumed in providing emergency service in public hospitals in Najran Province in Saudi Arabia. According to the results the study reached recommendations that could reduce occupational pressures to reduce time consumed in providing emergency service in public hospitals in Najran Province in Saudi Arabia

NAFLD and nutraceuticals: a review of completed phase III and IV clinical trials

BackgroundNonalcoholic Fatty Liver Disease (NAFLD) has become a significant public health concern, affecting approximately one-fourth of the population. Despite its prevalence, no FDA-approved drug treatments specifically target NAFLD.AimTo provide a review of clinical trials investigating the use of herbal remedies and dietary supplements in NAFLD management, utilizing the ClinicalTrials.gov database.MethodsThis review evaluates the current evidence by examining completed phase III and IV clinical trials registered on ClinicalTrials.gov. An exhaustive search was performed on April 17, 2023, using the terms “Nonalcoholic Fatty Liver Disease” and “NAFLD.” Two independent reviewers appraised eligible trials based on pre-defined inclusion and exclusion criteria.ResultsAn initial search yielded 1,226 clinical trials, with 12 meeting the inclusion criteria after filtration. The majority of trials focused on Omega-3 fatty acids (20.0%) and vitamin D (26.7%), followed by caffeine, chlorogenic acid, ginger, phosphatidylcholine, Trigonella Foenum-graecum seed extract, vitamin C, and vitamin E (each 6.7%). Most studies were Phase 3 (75.0%) and used a parallel assignment model (91.7%). Quadruple masking was the most prevalent technique (58.3%), and Iran was the leading country in terms of trial locations (25.0%). These interventions constitute two herbal interventions and nine supplement interventions.ConclusionThis reveals a diverse range of nutraceuticals, with Omega-3 fatty acids and vitamin D being predominant in the management of NAFLD. The global distribution of trials highlights the widespread interest in these therapeutics. However, more rigorous, large-scale trials are needed to establish safety, efficacy, and optimal dosages

Burden of musculoskeletal disorders in the Eastern Mediterranean Region, 1990–2013: findings from the Global Burden of Disease Study 2013

Moradi-Lakeh M, Forouzanfar MH, Vollset SE, et al. Burden of musculoskeletal disorders in the Eastern Mediterranean Region, 1990–2013: findings from the Global Burden of Disease Study 2013. Annals of the Rheumatic Diseases. 2017;76(8):annrheumdis-2016-210146