Chan Cheung Shing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 88-90). / Abstracts in English and Chinese. / Abstract --- p.ii / Acknowledgements --- p.iv / Table of Contents --- p.v / List of Figures --- p.viii / List of Tables --- p.xii / Abbreviations and Notations --- p.xiii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background and Objective --- p.1 / Chapter 1.2 --- Contribution --- p.4 / Chapter 1.3 --- Thesis Outline --- p.5 / Chapter Chapter 2 --- System Architecture --- p.6 / Chapter 2.1 --- Conceptual Design --- p.6 / Chapter 2.2 --- Sensing Device and Fall-Detection Algorithm --- p.7 / Chapter 2.3 --- Mechanical Part --- p.10 / Chapter Chapter 3 --- Mechanical Design --- p.11 / Chapter 3.1 --- Similar Products --- p.11 / Chapter 3.1.1 --- Airbag Restraining Systems in Automobiles --- p.11 / Chapter 3.1.2 --- Airbag Jackets for Motorcycle and House Riders --- p.12 / Chapter 3.2 --- Mechanism adopted --- p.12 / Chapter 3.2.1 --- Time Requirement of Inflator --- p.12 / Chapter 3.2.2 --- Mechanism and Design --- p.13 / Chapter 3.2.3 --- Actuator --- p.14 / Chapter 3.2.4 --- Punch --- p.15 / Chapter 3.2.5 --- Airbags --- p.18 / Chapter 3.2.6 --- Other Mechanisms Tried --- p.19 / Chapter 3.3 --- Prototype --- p.21 / Chapter 3.3.1 --- Implementation --- p.21 / Chapter 3.3.2 --- Demonstration --- p.23 / Chapter Chapter 4 --- Inflation Estimation --- p.25 / Chapter 4.1 --- Theory and Model --- p.25 / Chapter 4.2 --- Validation of Model --- p.28 / Chapter 4.2.1 --- Testing Equipment --- p.28 / Chapter 4.2.2 --- Preprocessing of Pressure Sensor Outputs --- p.28 / Chapter 4.2.3 --- Validation for Basic Equations --- p.29 / Chapter 4.2.4 --- Adjustment of Discharge Coefficients --- p.36 / Chapter 4.2.5 --- Validation for Discharging to a Fixed Volume --- p.40 / Chapter 4.2.6 --- Estimation of the Size of Airbag's Leakage Hole --- p.45 / Chapter 4.2.7 --- Validation for Discharging to an Airbag --- p.47 / Chapter 4.2.8 --- Time Delay due to Addition of a Pipe --- p.52 / Chapter 4.3 --- Summary of Experiments --- p.53 / Chapter 4.4 --- Limitation of Model --- p.54 / Chapter 4.5 --- Prediction of Inflation Time and Airbag Pressure --- p.55 / Chapter 4.5.1 --- Effects of Orifice Size and Vent Size on Airbag Pressure and Volume --- p.55 / Chapter Chapter 5 --- Force Attenuation Estimation --- p.58 / Chapter 5.1 --- Theory and Model --- p.58 / Chapter 5.1.1 --- Kelvin-Voigt Model --- p.59 / Chapter 5.1.2 --- Standard Linear Solid Support Model --- p.59 / Chapter 5.2 --- Simple Testing for Validation --- p.61 / Chapter 5.3 --- Summary of Experiment --- p.64 / Chapter 5.4 --- Estimation --- p.64 / Chapter 5.4.1 --- Force Attenuation Ability of Prototype --- p.64 / Chapter 5.4.2 --- Minimum Airbag Volume and Pressure Required to Reduce the Force --- p.65 / Chapter Chapter 6 --- Future Work --- p.66 / Chapter 6.1 --- Impact Test for Airbag System --- p.66 / Chapter 6.2 --- The Effective Mass of the Target User --- p.67 / Chapter 6.3 --- The Motion Data Collection --- p.68 / Chapter 6.4 --- Modification in the Inflator --- p.69 / Chapter Chapter 7 --- Conclusion --- p.70 / Appendix A Review of Basic Thermodynamics and Fluid Dynamics --- p.72 / Chapter A.1 --- Thermodynamics --- p.72 / Chapter A.2 --- Fluid Mechanics: Incompressible and Compressible Flow --- p.75 / Appendix B Derivation of Equations --- p.77 / Chapter B.1 --- Mass Flow Rate Equations --- p.77 / Chapter B.2 --- Relationship between Rate of Changes of Airbag Pressure and Volume --- p.80 / Chapter B.3 --- Pressure Change of Compressed Gas Cylinder --- p.82 / Chapter B.4 --- Dominating Factors in the Mass Flow Rate Equation --- p.83 / Appendix C Dimensions of Inflator --- p.85 / Appendix D Experimental Data --- p.86

Dissertation (Ph.D.)--University of South Florida, 2009. / Title from PDF of title page. Document formatted into pages; contains 224 pages. Includes vita. Includes bibliographical references.

Background. Carotid stenosis is an important cause of stroke. Carotid endarterectomy is a means of reducing the burden of stroke but is of marginal benefit in individuals with asymptomatic carotid stenosis. The identification of factors associated with increased risk of cerebral ischemic events would help select individuals who may obtain a greater benefit. / Methods. A comprehensive search was performed to identify studies examining risk factors for cerebral ischemic events in patients with asymptomatic carotid stenosis. Inclusion criteria were defined a priori. Relevant studies were reviewed, assessed for quality, and data were extracted. / Results. Thirty-four studies met the inclusion criteria. There was a suggestion of increasing neurological events with increasing severity and progression of carotid stenosis. There was some evidence for an association with carotid plaque morphology. No consistent association was found with clinical factors, impaired cerebral vasoreactivity, or cerebral embolic signals. / Conclusions. The evidence is insufficient to reliably identify individuals with asymptomatic carotid stenosis who are at a higher risk of cerebral ischemic events.

Thesis (M.S.)--University of South Florida, 2007. / Title from PDF of title page. Document formatted into pages; contains 52 pages. Includes bibliographical references.

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Degree of Masters in Public Health by coursework and research report Maternal and Child Johannesburg, March 2012 / Adolescent sexual behaviour related to low condom-use and early sexual debut has been a concern in the transmission of sexually transmitted infections (STIs) and HIV. Treatment-seeking behaviour is a problem in adolescents due to embarrassment and unfriendly health care services. The Birth to Twenty study group (Bt20) is a cohort of singletons born in 1990 with approximately 10% having tested positive for STIs at an early age. Their sexually activity and unprotected sex practices have increased their risk for HIV infection. The objectives of this study were to explore the perceptions, sexual behaviour and treatment-seeking behaviour of a sample of girls who had a previous STI, through their narratives. One-on-one narrative interviews were done on 19 girls with the aid of an interview schedule. A life history of their sexual encounters was documented. The interviews were taped and transcribed. Thematic analysis was performed. The majority of the girls had no knowledge of STIs before they were counselled by the Bt20 nurses yet 50% of the girls used condoms in their first sexual experiences. Once counselled, almost all the girls went on to seek treatment for their STI. A third of the girls reported poor service at the clinic and would prefer to be treated either privately or at Bt20 if possible. Information regarding the role of STIs in the transmission of HIV seems to be unclear. Improving the life orientation programme at schools with a focus on STIs and pregnancy would positively impact on HIV transmission. One-on-one counselling is effective but may not be feasible in under-resourced communities and the continued education of nurses in clinics, whilst increasing the number of adolescent friendly clinics, must be prioritised.

A thesis completed by published work, Submitted to the School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, in fulfillment of the requirements for the degree of Doctor of Philosophy Johannesburg, South Africa 24 May 2017. / Introduction: Prevention of mother-to-child transmission (PMTCT) has potential to eliminate new HIV infections among infants. Yet, in many settings in sub-Saharan Africa, women are unable to adhere to PMTCT recommendations due to social constraints. One such factor may be intimate partner violence (IPV), or any actions taken by a relationship partner that cause physical, sexual, or psychological harm. Despite theoretical and empirical rationale for understanding the links between IPV and PMTCT adherence, few studies in the extant literature have explored this association. Methods: This thesis draws upon four distinct studies that interface using an overall mixed method study design. The first study is a systematic review of the literature around women’s experience of lifetime IPV and adherence to anti-retroviral treatment (ART). The second study is formative qualitative research with pregnant women, health workers, and other local stakeholders that explores how IPV may be related to PMTCT in the urban Johannesburg setting. The third study is a deeper qualitative examination of women living with both IPV and HIV, aiming to understand the mechanisms that link partner violence to PMTCT behaviors using a social constructionist lens. The final study is a quantitative cohort study nested within a randomized control trial testing an intervention for IPV in pregnancy. Using regression techniques and structural equation modeling, I aim to determine the association between IPV and ART adherence in pregnancy and postpartum and identify pathways that mediate the relationship between partner violence and PMTCT. Results: This doctoral research contributes several new findings to the extant literature around PMTCT. I find that IPV is related to ART adherence among HIV-positive women in extant literature, with meta-analysis showing significantly worse odds of ART uptake, self-reported adherence, and viral suppression among women reporting lifetime IPV. In one of first of studies among women in sub-Saharan Africa, I learn that impact of IPV on ART adherence in pregnancy and postpartum is marked. I identify several mechanisms through which IPV influences PMTCT adherence. Mental health emerges as a robust pathway linking IPV to worse adherence in both qualitative and quantitative papers. Partner non-disclosure due to IPV can impede adherence, or women can navigate this challenge through hiding their HIV status or medication. Women experiencing IPV may attend fewer antenatal clinic visits, leading to worsened adherence. An unexpected finding was that women in our qualitative and quantitative studies were resilient and used strategies to adhere despite IPV. Motherhood seems to be a central feature of women who are resilient to the effects of IPV on adherence. Conclusion: The findings of this research have implications for research, policy, and practice. Research should incorporate social factors, such as IPV, into future studies testing PMTCT adherence interventions. Clinical practice and HIV programs should recognize that partner-level dynamics such as IPV may drive persistent gaps in PMTCT coverage. HIV policy urgently needs to incorporate ethical and safety considerations for women who experience IPV around the time of pregnancy. Women living with recent or past IPV are highly resilient and often want to protect their own health and that of their children. Only by recognizing and addressing their experience within the context of HIV care can future PMTCT programs and studies ensure maternal and infant health. / MT2017

A DISSERTATION SUBMITTED TO THE FACULTY OF MEDICINE, UNIVERSITY OF THE WITWATERSRAND, JOHANNESBURG, FR THE DEGREE OF MASTER OF SCIENCE IN MEDICINE. / The influence of iron on the outcome of various infections have been extensively reviewed. Clinical observations suggests that iron deficiency may be protective against malaria. Various researchers have shown that certain iron chelators blocked the proliferation of plasmodium falciparum in vitro and in vivo. (Abbreviation abstract) / Andrew Chakane 2018

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Medicine in Emergency Medicine. Johannesburg, March, 2016 / Objectives: The aim of the current research was to determine the perception and experience of different emergency department occupational groups regarding workplace violence in the past 12 months and to determine the effect that it had on them in two government hospitals in Johannesburg, South Africa. Materials and Methods: The current research was a cross sectional, retrospective qualitative survey. Results: Eighty-six surveys (43%) out of the distributed 200 questionnaires were returned. Five surveys were unfilled leaving 81 surveys (40.5%) that are included in the analysis. Psychological violence was experienced by 73 % (n=51) of the participants while physical violence was experienced by 34.2% (n=27). Patients were the perpetrators of 61% and 67.9% of psychological and physical violence against staff members, respectively. Friends and family members who accompanied patients in the emergency department accounted for 27.4% psychological violence while this same set of people caused 17.3% of physical violence. Ninety-one percent of the participants reported that they did not receive any training courses on how to handle workplace violence incidents. Medical staff (doctors and nurses) were found to be at an increased risk to psychological violence. Conclusions: Workplace violence was commonly experienced by ED staff members. Majority of the incidents were in the form of psychological violence; however, a considerable percentage of the participants experienced physical violent incidents. Most of the violent incidents experienced were perceived to be preventable by majority of participants. This research supports the need for practical training and education of the ED staff members, on how to prevent and deal with issues related to ED WPV. / MT2016

A thesis completed by published work, Submitted to the School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, in fulfilment of the requirements for the degree of Doctor of Philosophy Johannesburg, South Africa December 2016. / Introduction With the largest epidemic in the world, the consequences of human immunodeficiency virus (HIV) in South Africa extend far beyond its disease burden. In fact, patterns of HIV-related infection and mortality in South Africa still reflect social cleavages and inequalities. Similarly, poverty-related issues such as poor education, unemployment and subsequent low socio-economic status, rural residence and inadequate access to health care are all implicated in human papillomavirus (HPV) associated cervical cancer-related mortality (of which South Africa also has the highest globally). Despite the knowledge of reproductive functions and sexuality being poor among adolescents in South Africa, the majority commence their sexual activity early with an estimated national average of 15 years for girls and 14 years for boys. Further, many South African adolescents engage in sexual risk-taking behaviours including concurrent partners and unprotected sexual acts that considerably increase their vulnerability to sexually transmitted infections including HIV and HPV. In recognising the unique health needs of adolescents in South Africa, the national government has already pin-pointed school health services as a strategic arm of primary health care re-engineering. The aim of this body of work is to elaborate on restructuring of adolescent health care by introducing the HIV and HPV vaccine concomitantly in South Africa via a school-based sexual and reproductive health service. Methodology Data from four studies were analysed and are presented in three published and two unpublished papers. The first study evaluated the synergism between HIV and HPV in the South African context and formed the basis of the literature review. The second study considered HIV vaccine implementation alone. The third study assessed dual HIV and HPV vaccine strategies among females and the final study compared the dual vaccination strategy against recognised biomedical HIV prevention interventions. The studies evaluated the implementation of a hypothetical HIV vaccine and the bivalent HPV vaccine both individually and in combination when administered to school-going adolescents in South Africa. The health outcomes and the cost-effectiveness of these strategies were assessed. Assumptions were made regarding the hypothetical HIV vaccine (based on HIV vaccine studies conducted to date) including a coverage rate of 60% (uncertainty range: 30-70%), vaccine efficacy of 50% (uncertainty range: 30-70%) and vaccine price per dose of US$ 12 (uncertainty range: US$ 3-24). The uncertainty ranges were tested in the sensitivity analysis. Mortality statistics, disease transition parameters (for the individual diseases and the models representing joint disease) and HPV vaccine characteristics were drawn from the South African literature. The joint effectiveness of the dual vaccine strategy was considered multiplicative. Nine year old adolescents attending South African schools in 2012 were eligible for the intervention (vaccination) that was introduced opportunistically as part of the national health initiative introducing school-based sexual and reproductive health services. The learners were targeted prior to their reported sexual debut. The HIV vaccine was considered against the comparator of HIV counselling and testing (HCT) and the national roll-out of antiretroviral therapy (ART) that constituted the standard of care in South Africa. The HPV vaccine was modelled as prevention against HPV-related cervical cancer and pre-cancerous HPV-related cervical states. The health service provider (provider) perspective was adopted and the cohort was modelled through a lifetime horizon of 70 years with annual cycles. The economic costs and health outcomes were discounted at 3% with an uncertainty range between 0% and 6% assessed. Cost valuations were for 2012 and costs were adjusted to this common year. The quality-adjusted life year (QALY) was used as the outcome measure of health related quality of life and was used to calculate the incremental cost-effectiveness ratio (ICER) of the comparator against the vaccination interventions. The core model was a semi-Markov simulation with annual cycles. The study population entered the model HIV and HPV disease free and were exposed to the risk of acquiring each disease annually. The model structure was parameterised drawing from South African data available in the literature. One-way sensitivity analyses evaluated the impact of single assumptions on cost and outcomes. Probabilistic sensitivity analysis (PSA) with a bootstrapping technique explored the uncertainty in the model and evaluated the robustness of the results. The PSA data generated determined if the intervention fell below the willingness-to-pay (WTP) threshold. As South Africa does not have a pre-defined WTP threshold, the Gross Domestic Product (GDP) per capita (for 2012) was used as a proxy in accordance with the World Health Organization’s Guide to Cost-Effective Analysis. Additionally, benchmark interventions were used in the final comparison study as a measure of cost-effectiveness. Ethical approval for the study was obtained from the Human Research Ethics Committee (Medical) of the University of the Witwatersrand. Findings The second study explored the implementation of the HIV vaccine on an individual and national, programmatic level. The simultaneous implementation of HIV vaccination services with current HIV management programmes would be cost-effective, even at relatively higher vaccine cost. At base vaccine cost of US$ 12, the ICER was US$ 43 per QALY gained, with improved ICER values yielded at lower vaccine costs. The ICER was sensitive to the duration of vaccine-mediated protection and to variations in the vaccine efficacy. Data from this work demonstrate that vaccines offering longer duration of protection and at lower cost would result in improved ICER values. Assessing this HIV vaccine model on a national programmatic level, yielded an ICER of US$ 5 per life-year gained (LYG) (95% CI US$ 3-12) compared with the comparator. This fell considerably below the national WTP threshold of cost-effectiveness. This also translated to an 11% increase in per capita costs from US$ 80 to US$ 89. National implementation of this intervention could potentially result in an estimated cumulative gain of 24 million years of life (95% CI 8–34 million years) among those adolescents aged between 10-19 years that were vaccinated. The 10 year absolute risk reduction projected by HIV vaccine implementation was 0.42% for HIV incidence and 0.41% for HIV mortality. The ICER was sensitive to the HIV vaccine efficacy, coverage and vaccine pricing in the sensitivity analysis. The third study assessed the impact of dual HIV and HPV implementation strategies. Programmes that involved the dual vaccine strategy were assessed as cost-saving. ICER values were sensitive to the HIV vaccine cost. The dual vaccine strategy resulted in 10 year absolute risk reductions in HIV incidence (5.24%), dual mortality (1.21%) and a reduction in HPV incidence (0.39%) compared with no vaccination. Importantly, the reduction in HIV incidence rate and dual mortality rate in the dual vaccine strategy exceeded the reductions noted with the use of the HIV vaccine alone. All scenarios assessed with the dual vaccine strategy were cost-effective. Lower vaccine prices and reduced discount rates were associated with improved ICER outcomes. The final study compared the biomedical interventions of oral pre-exposure prophylaxis (PrEP), voluntary medical male circumcision (VMMC) and the scaling-up of ART coverage against the vaccine strategies. When compared with other biomedical HIV prevention interventions, the dual vaccination intervention was the most cost-effective strategy (US$ 7 per QALY gained) and averted 29% of new HIV infections. VMMC (US$ 30 per QALY gained) proved more cost-effective than HIV vaccination alone (US$ 93 per QALY gained), though VMMC averted 6% more new infections than the HIV vaccine. PrEP interventions were the least cost-effective. Combined dual vaccination and VMMC strategies represent the only dominant intervention. Strategies involving oral PrEP were the least cost-effective. Conclusion The findings of this thesis have implications for school-based adolescent health care and HIV- and HPV-related disease prevention among adolescents, a highly susceptible population. The cost-effectiveness of the dual HIV and HPV vaccine strategy was demonstrated, and the improved health outcomes associated with the interventions quantified. Proposals were suggested regarding possible combinations of HIV prevention interventions that could yield the favourable health outcomes with the most efficient use of financial resources. Several important areas for future research were identified to shed light on improving adolescent health care and for optimising HIV prevention strategies. These include integrating HIV and HPV services as part of the re-engineering of primary health care in South Africa, and then formulating economic evaluations of HIV/HPV prevention strategies targeting adolescents specifically. Further, more effective methods of collecting data on socially marginalised populations such as young people need to be explored. Another vital research area is the discussion and implementation of existing school health documents with the ideals embodied in the school health programme envisaged under the National Health Insurance restructuring. Once these are integrated, the cost implication of the combined programmes need to be assessed. / MT2017