Design And Evaluation Of Wireless Technology Systems For Data Analysis

DissertationThe internet and cloud storage are becoming increasingly important to researchers, hobbyists and commercial developers. This includes the transmission of reliable data as the availability and functionality of remote sensors and IoT devices are becoming more common. The availability of high-speed internet connections, like fibre-optic cable, LTE and digital radios, changed the playing field and enabled the user to transmit data to cloud storage as speedily as possible. With these various technologies available, the question now arises: Which technology is more reliable and efficient for IoT sensors and for users to transmit data to a cloud server? This project aims to investigate the reliability and transmission delay of transmitted data from Wi-Fi, GPRS Class 10, and digital radio networks to cloud storage. A sampling unit was designed to evaluate analogue inputs periodically and send the recorded data to the three technologies under test. It also records the data to an on-board micro SD card along with an indexing system. The systems then transmit the sampled data and index number to a cloud storage server via the communication technologies under test. The cloud-stored data is then compared with the recorded data of the sampler unit to determine data integrity. The transmission delays can be calculated by using the cloud storage server’s time stamp information and the original time stamp of each data message. From the results acquired in the research, it showed that digital radio is a very reliable and stable means of data communication but it lacks direct connection to the internet. Although, both Wi-Fi and GPRS Class 10 are permanently connected to the internet, it was also observed that Wi-Fi internet connectivity may be susceptible to interference from external factors like the continuity of supply from the national power grid and from load shedding. It also showed that the XBee digital radio system lost 0.21% packets compared to the 0.31% for Wi-Fi and 1.46% for GPRS Class 10. On the other hand, although GPRS Class 10 may be a bit less reliable than digital radio and Wi-Fi, it is relatively cheap to use and has the ability to connect to multiple communication towers for communications redundancy. The outcome of this research may help researchers, hobbyists and commercial developers to make a better-informed decision about the technology they wish to use for their particular project

Variants within the MMP3 gene are associated with achilles tendinopathy: possible interaction with the COL5A1 gene

Objectives: Sequence variation within the COL5A1 and TNC genes are known to associate with Achilles tendinopathy. The primary aim of this case-control genetic association study was to investigate whether variants within the matrix metalloproteinase 3 (MMP3) gene also contributed to both Achilles tendinopathy and Achilles tendon rupture in a Caucasian population. A secondary aim was to establish whether variants within the MMP3 gene interacted with the COL5A1 rs12722 variant to raise risk of these pathologies. Methods: 114 subjects with symptoms of Achilles tendon pathology and 98 healthy controls were genotyped for MMP3 variants rs679620, rs591058 and rs650108. Results: As single markers, significant associations were found between the GG genotype of rs679620 (OR = 2.5, 95% CI 1.2 to 4.90, p = 0.010), the CC genotype of rs591058 (OR = 2.3, 95% CI 1.1 to 4.50, p = 0.023) and the AA genotype of rs650108 (OR = 4.9, 95% CI 1.0 to 24.1, p = 0.043) and risk of Achilles tendinopathy. The ATG haplotype (rs679620, rs591058, and rs650108) was under-represented in the tendinopathy group when compared to the control group (41% vs 53%, p = 0.038). Finally, the G allele of rs679620 and the T allele of COL5A1 rs12722 significantly interacted to raise risk of AT (p = 0.006). No associations were found between any of the MMP3 markers and Achilles tendon rupture. Conclusion: Variants within the MMP3 gene are associated with Achilles tendinopathy. Furthermore, the MMP3 gene variant rs679620 and the COL5A1 marker rs12722 interact to modify the risk of tendinopathy. These data further support a genetic contribution to a common sports related injur

Characterisation of the Tensile and Metallurgical Properties of Laser Powder Bed Fusion-Produced Ti-6Al-4V ELI in the Duplex Annealed and Dry Electropolished Conditions

Metal additive manufacturing is becoming a popular manufacturing process in industries requiring geometrically complex components, part consolidation, and reductions in material waste. Metals manufactured via additive manufacturing processes such as laser powder bed fusion typically exhibit process-induced defects, material inhomogeneities, and anisotropy in terms of mechanical properties. Post-processing techniques such as heat treatments and surface finishing have been touted as approaches for improving these materials. Although various post-processing techniques have been proposed, the optimal post-processing route remains an active area of research. This research investigates Ti-6Al-4V ELI produced using laser powder bed fusion and post-processed via different routes. The materials in the stress-relieved and duplex annealed material conditions as well as dry electropolished and machined surface conditions were characterised. The duplex annealed Ti-6Al-4V ELI material showed improvements in ductility but at reduced strength when compared with the material in the stress-relieved condition. The microstructure of the duplex annealed material shows little evidence of process-induced defects and features and consists primarily of elongated and acicular α in a lamellar structure with intergranular β and exhibits uniform microhardness throughout the material. A reduced surface roughness due to surface finishing resulted in an improved reduction in area. This research highlights the effects of post-processing treatments and their ability to improve the properties of laser powder bed fusion-produced Ti-6Al-4V ELI

Proximal oesophageal strictures in a child with HIV disease

The patient and her twin brother were born preterm by caesarean section. Her birth weight was 2 100 g. She had perinatal exposure to HIV, and was therefore bottle-fed with term formula milk.She remained well until the age of 11 months when, weighing 6 880 g, she required hospital admission for a right upper lobe pneumonia, which responded well to oral amoxicillin. No causative organism was isolated. There was no evidence of active tuberculous infection on gastric washings or Mantoux test

Islet neogenesis is stimulated by brief occlusion of the main pancreatic duct

Objective. Current models of islet neogenesis either cause substantial pancreatic damage or continuously stimulate the pancreas, making these models unsuitable for the study of early events that occur in the neogenic process. We aimed to develop a method where the initial events that culminate in increased pancreatic endocrine mass caube studied. Design and methods. Ten 12-week-old female Wistar rats were subjected to a midline laparotomy, the pancreas was isolated and the main pancreatic duct was occluded for 60 seconds. The pancreas was released and carefully relocated within the abdomen. Ten age-, strain- and sex-matched control rats were subjected to a sham operation. The animals were killed 56 days post .occlusion, and the pancreata excised and fiXed tor histological analysis. Body, pancreatic and hepatic weights were .noted at termination. and serum was taken for analysis. The endocrine-to-exocrine. ratio was calculated and the number of endocrine cells in eacn islet from the sectioned pancreata was counted. Results. Occlusion of the main pancreatic ductfor 60 seconds results in an increase in endocrine mass. by 80% 56 days post occlusion. This constitutes an increase in endocrine units (1 - 6 cellst and in small (7 - 30 cells), medium (31 - 60 cells) and large (> 60 cells) islets by 85%, 96%, 95% and 71% respectively. Conclusion. Brief occlusion of the main pancreatic duct results in anincrease in pancreatic endocrine. mass. An increase in endocrine units and small islets is indicative of islet neogenesis. Therefore, owing to the briefness of the stimulation; this model can therefore be used to study the iniUal events that occur during the neogenic process

Factors influencing the development of early- or late-onset Parkinson’s disease in a cohort of South African patients

Background. Neurodegenerative disorders such as Parkinson’s disease (PD) contribute significantly to global disease burden. PD can be categorised into early-onset PD (EOPD) with an age at onset (AAO) of ≤50 years and late-onset PD (LOPD) with an AAO of 50 years. Aims. To identify factors influencing EOPD and LOPD development in a group of patients in South Africa (SA). Methods. A total of 397 unrelated PD patients were recruited from the Movement Disorders Clinic at Tygerberg Hospital and via the Parkinson’s Association of SA. Patient demographic and environmental data were recorded and associations with PD onset (EOPD v. LOPD) were analysed with a Pearson’s Chi-squared test. The English- and Afrikaans-speaking (Afrikaner) white patients were analysed separately. Results. Logistic regression analysis showed that ethnicity (