Signal space cooperative communication with partial relay selection.

Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2012.Exploiting the available diversity from various sources in wireless networks is an easy way to improve performance at the expense of additional hardware, space, complexity and/or bandwidth. Signal space diversity (SSD) and cooperative communication are two promising techniques that exploit the available signal space and space diversity respectively. This study first presents symbol error rate (SER) analysis of an SSD system containing a single transmit antenna and N receive antennas with maximal-ratio combining (MRC) reception; thereafter it presents a simplified maximum-likelihood (ML) detection scheme for SSD systems, and finally presents the incorporation of SSD into a distributed switch and stay combining with partial relay selection (DSSC-PRS) system. Performance analysis of an SSD system containing a single transmit antenna and multiple receive antennas with MRC reception has been presented previously in the literature using the nearest neighbour (NN) approximation to the union bound, however results were not presented in closed form. Hence, closed form expressions are presented in this work. A new lower bound for the SER of an SSD system is also presented which is simpler to evaluate than the union bound/NN approximation and also simpler to use with other systems. The new lower bound is based on the minimum Euclidean distance of a rotated constellation and is termed the minimum distance lower bound (MDLB); it is also presented here in closed form. The presented bounds have been validated with simulation and found to be tight under certain conditions. The SSD scheme offers error performance and diversity benefits with the only penalty being an increase in detector complexity. Detection is performed in the ML sense and conventionally, all points in an M-ary quadrature amplitude modulation (M-QAM) constellation are searched to find the transmitted symbol. Hence, a simplified detection scheme is proposed that only searches m symbols from M after performing initial signal conditioning. The simplified detection scheme is able to provide SER performance close to that of optimal ML detection in systems with multiple receive antennas. Cooperative communication systems can benefit from the error performance and diversity gains of the spectrally efficient SSD scheme since it requires no additional hardware, bandwidth or transmit power. Integrating SSD into a DSSC-PRS system has shown an improvement of approximately 5dB at an SER of 10-4 with a slight decrease in spectral efficiency at low SNR. Analysis has been performed using the newly derived MDLB and confirmed with simulation

Trends in glycaemic control and morbidity over 10 years in patients with type 1 diabetes mellitus at Inkosi Albert Luthuli Central Hospital

Aim: To assess control and morbidity in patients with type 1 diabetes mellitus (T1 attending a tertiary adult diabetes clinic in Durban, South Africa.Methods: A retrospective chart review of all patients with T1D who attended clinic in the years 2006, 2012 and 2015. Clinical and laboratory changes were assessed at an individual patient-level follow-up (IPLF) and whole clinic level (n = 231).Results: In the IPLF study arm (n = 58; 45% Black patients; 62% female; median age 18 years), mean HbA1c [% (mmol/mol)] decreased from 9.9 ± 2.6% (85 ± 28) in 2006 to 8.7 ± 1.5% (72 ± 16) in 2012 (p < 0.001) and to 9.1 ± 1.7% (76 ± 19) in 2015 (p = 0.03); target HbA1c < 7.0% (< 53 mmol/mol) was achieved in 7.1%, 5.3% and 8.3%, respectively. Compared with 2006, in 2015 there was a higher prevalence of retinopathy (10.3% vs. 29.3%, p = 0.004), abnormal glomerular filtration rate (0% vs. 6.9%, p = 0.04) and abnormal serum creatinine (0% vs. 8.6%, p = 0.02). Predictive risk factors for new retinopathy included diabetes duration (OR 1.4; 95% CI 1.0–1.3; p = 0.03) and diastolic blood pressure (OR 1.15; 95% CI 1.0–1.3; p = 0.04).Conclusion: Glycaemic control improved over 10 years, but fell short of recommended targets. Intensive efforts are required to achieve current targets for glycaemic and non-glycaemic control

Women in rheumatology in Africa

Despite the increasing occurrence of rheumatic diseases worldwide, there is poor access to rheumatology services and few rheumatologists to provide these services in many regions of the world. This fact is particularly true in areas of lower socioeconomic status and low-income and middle-income countires. Studies across various countries show a relative shortage of rheumatologists compared with the rising need for the specialty worldwide

Consensus evidence-based clinical practice guidelines for the diagnosis and treat-to-target management of osteoporosis in Africa: an initiative by the African Society of Bone Health and Metabolic Bone Diseases.

The objective of this consensus statement is to inform the clinical practice communities, research centres and policymakers across Africa of the results of the recommendations for osteoporosis prevention, diagnosis and management. The developed guideline provides state-of-the-art information and presents the conclusions and recommendations of the consensus panel regarding these issues. To reach an African expert consensus on a treat-to-target strategy, based on current evidence for best practice, for the management of osteoporosis and prevention of fractures. A 3-round Delphi process was conducted with 17 osteoporosis experts from different African countries. All rounds were conducted online. In round 1, experts reviewed a list of 21 key clinical questions. In rounds 2 and 3, they rated the statements stratified under each domain for its fit (on a scale of 1-9). After each round, statements were retired, modified or added in view of the experts' suggestions and the percent agreement was calculated. Statements receiving rates of 7-9 by more than 75% of experts' votes were considered as achieving consensus. The developed guidelines adopted a fracture risk-centric approach. Results of round 1 revealed that of the 21 proposed domains, 10 were accepted whereas 11 were amended. In round 2, 32 statements were presented: 2 statements were retired for similarity, 9 statements reached consensus, whereas modifications were suggested for 21 statements. After the 3rd round of rating, the experts came to consensus on the 32 statements. Frequency of high-rate recommendation ranged from 83.33 to 100%. The response rate of the experts was 100%. An algorithm for the osteoporosis management osteoporosis was suggested. This study is an important step in setting up a standardised osteoporosis service across the continent. Building a single model that can be applied in standard practice across Africa will enable the clinicians to face the key challenges of managing osteoporosis; furthermore, it highlights the unmet needs for the policymakers responsible for providing bone health care together with and positive outcomes of patients' care. [Abstract copyright: © 2021. International Osteoporosis Foundation and National Osteoporosis Foundation.