MMed (Paediatrics), Faculty of health Sciences, University of the Witwatersrand / AIM: To evaluate aspects of the PMTCT programmes at selected hospitals and clinics in Gauteng. METHOD: A cross sectional survey of post partum women in Gauteng was undertaken during April- June 2006. Data was collected at four hospitals and eight Midwife Obstetric Units (MOUs) in four regions in Gauteng. Mothers, irrespective of HIV status, who delivered in the previous 48 hours were interviewed. This was followed by a review of the mother’s and infant’s records as well as relevant registers. RESULTS: Interviews with, and record reviews, of 182 mother-infant pairs were conducted/obtained; 69 (38%) at MOUs and 113 (62%) at hospitals. The majority (172 [95%]) of mothers were “booked” of whom 155 (85%) had undergone an antenatal HIV test. Forty-two mothers (23%) were HIV positive. Nevirapine was issued antenatally to 37/42 (89%) of eligible mothers; 30/42 (71%) took it during labour. Three women (8%) received the drug for the first time during labour; thus 33/42 (79%) of eligible mothers received nevirapine. Thirtytwo (76%) of babies born to HIV positive mothers received nevirapine. However, in only 24/42 of mother-infant pairs (57%) was receipt of nevirapine by both parties, recorded. There was no significant difference in nevirapine administration rates to mothers at clinics compared to hospitals (76% vs. 81%, p=0.71). Infants were more likely to receive nevirapine at clinics compared to hospitals (90% vs. 62%, p= 0.03). CONCLUSION: Four years after introduction of a PMTCT programme in Gauteng, nevirapine uptake and administration rates remained sub-optimal, with at least a quarter of eligible (identified) women and infants not receiving the intervention. The findings highlight the need to prioritise and consolidate PMTCT activities in the province.

MFamMed, Faculty of Health Sciences, University of the Witwatersrand, 2009 / BACKGROUND Until recent years, uptake of voluntary counselling and testing for HIV (VCT) and enrolment into the programme of prevention of mother-to-child transmission of HIV (PMTCT) was very poor among pregnant women. This study aims to identify factors influencing enrolment into the programme of PMTCT among post-partum women. METHODS Cross sectional interview of 200 consecutive post-partum women was conducted using an interviewer-administered questionnaire. Forms of those who declined to participate were kept and marked “refusal”. Data was analysed using Epi info software. RESULTS The response rate was 84.5%. VCT uptake was 96.9% among participants and PMTCT uptake among HIV+ve mothers was 90.9%. The mean age of participants was 25 years, ranged from 14 to 41 years. Women in the age-group 20-29 were more likely to accept VCT and enroll for PMTCT than women in the other age-groups (p=0.0114). CONCLUSIONS AND RECOMMENDATIONS Provision of clear and well-defined policy guidelines and strong commitment to implementation of these guidelines have been largely responsible for impressive uptake of VCT among participants and high rates of satisfaction with PMTCT programme among HIV-infected women. Training of more lay-counsellors is recommended for its cost-effectiveness.

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 Public Health. Johannesburg, April 2012 / Introduction Routine PMTCT programmes are highly effective in reducing the mother-to-child transmission (MTCT) rate of HIV, but generally fail in follow-up of HIV-exposed children. Loss to follow-up in the PMTCT programme translates into failure in primary prevention of new infections in HIV-exposed infants, failure to identify HIV disease early in children, and a missed opportunity for early referral of HIV-positive children to ARV sites. An assessment of what happens to babies born of HIV-positive mothers in the West Rand district of Gauteng province, South Africa has never been done, and neither has the extent to which these babies are followed up for the first 12 months, and the extent of loss to follow-up been documented. Aim The purpose of this study is to describe the referral and follow-up of babies born to HIV-positive women during July to December 2005 in the PMTCT programme in the West Rand district of Gauteng. Method This was a descriptive study involving a retrospective review of records for a cohort of babies born to HIV-positive mothers in the PMTCT programme in the West Rand during July 2005 to December 2005. All records of HIV-positive mothers seen over the six-month period at Leratong hospital and the two midwife obstetric units (MOUs) that refer patients to Leratong hospital were reviewed, as were records of their babies. A total of 887 Mother-infant pairs were consecutively enrolled in the study. Results Referral linkages within the PMTCT programme were found to be weak. Only 34% of babies enrolled in the PMTCT programme were successfully registered with PMTCT follow-up services. HIV PCR testing of babies enrolled in the PMTCT programme was relatively low. Overall only 41% of enrolled babies were tested for HIV infection. Of those babies who had a HIV PCR test, 16% were tested before or at six weeks with the majority of babies (84%) having a HIV PCR after six weeks. HIV PCR testing coverage at six weeks was 8.4%. Referral of confirmed HIV-positive babies to ARV sites was poor. Only 25% of all HIV PCR-positive infants were successfully referred to ARV sites. There was a high loss to follow-up in the PMTCT follow-up programme. The probability of an infant remaining in the PMTCT programme decreased from 0.5 at six weeks to 0.04 beyond 20 weeks. Conclusion Despite a high enrolment of babies in the PMTCT programme in the West Rand, referral linkages within the PMTCT programme are weak and there is a high loss to follow-up of infants in the PMTCT follow-up programme. HIV PCR coverage at six weeks is significantly low, and referral of confirmed HIV PCR-positive babies to ARV sites is also significantly low. Further research is needed to assess whether there has been an improvement in the follow-up of babies in the PMTCT programme in the West Rand since the time of this study.

La Fièvre de la Vallée du Rift (VFVR) est une arbovirose zoonotique affectant principalement les ruminants et les humains. Son éco-épidémiologie complexe implique de nombreuses espèces de vecteurs, d'hôtes et de voies de transmission. Ainsi, différents mécanismes de transmission et d'émergence sont impliqués dans la circulation du virus de la FVR (VFVR) et ceux-ci dans des écosystèmes contrastés d'Afrique, de la Péninsule Arabique et des îles du sud-ouest de l'Océan Indien, dont l'île de Madagascar.Par sa superficie, sa grande diversité éco-climatique et sa faune et flore endémique, Madagascar est considérée comme une île continent. On y retrouve, en effet, des écosystèmes variés plus ou moins favorables aux moustiques : semi-arides dans le sud-ouest, humides et froids sur les hautes terres centrales, per-humide dans l'est et humides et chaud dans le nord-ouest. Madagascar a été affectée par deux épidémies de FVR en 1990-91 puis 2008-09. Une étude menée lors de la dernière épidémie a montré que le virus avait largement diffusé dans l'île de façon hétérogène.Compte tenu de la complexité des mécanismes de transmission de la FVR et de la diversité des écosystèmes de Madagascar, nous avons supposé que cette hétérogénéité spatiale était due à des mécanismes de transmission et d'émergence qui variaient en fonction des écosystèmes de l'île. Ainsi, le premier objectif de ce travail de thèse étaient de déterminer les mécanismes et les dynamiques de transmission de la FVR inhérents aux différents écosystèmes de Madagascar. Le second objectif a été d'identifier les mécanismes d'émergence de la FVR à Madagascar et de déterminer s'il sera possible, et nécessaire, de prédire cette émergence à l'échelle des écosystèmes.Dans le cadre de ce travail de thèse deux enquêtes sérologiques nationales, l'une bovine (2008) et l'autre humaine (2011-13) ont, premièrement, été analysées par un modèle linéaire mixte généralisé afin d'identifier les facteurs environnementaux et comportementaux favorables à la circulation du virus chez les bovins et les humains. Deuxièmement, deux enquêtes sérologiques bovines, l'une réalisée en 2008 et l'autre en 2014, ont été analysées pour reconstruire la dynamique de transmission de la FVR dans les différents écosystèmes de l'île. Cette reconstruction a été réalisée à partir de données de séroprévalence et d'âge inclues dans un modèle Bayésien hiérarchique pour estimer la force d'infection annuelle de 1992 à 2014. Enfin, afin de faire le lien biologique avec les résultats des travaux menés à une échelle nationale et de décrire les mécanismes de transmission à une échelle fine, des enquêtes longitudinales entomologiques et sérologiques ont été réalisées entre 2015 et 2016 dans un écosystème à risque. Et ceci, afin de décrire la transmission saisonnière du VFVR chez les ruminants associée à la dynamique de transmission des vecteurs potentiels.Nos résultats ont montré que la région du nord-ouest de l'île est une région à risque de transmission. D'une part, elle est constituée d'environnements associant une forte densité de bovins à des zones humides, inondables et irriguées, favorables aux espèces d'Anopheles et Culex. D'autre part, le VFVR semble avoir circulé de façon relativement intense lors de la période inter-épizootique de 1992 à 2007, puis sa transmission a soudainement augmenté en 2007-2008, ce qui est concomitant avec l'apparition des foyers de FVR en 2008. Pour finir, 6 ans après l'épidémie de FVR à Madagascar, le virus semble toujours circuler à bas bruit dans la région. Cette circulation étant probablement due à une transmission vectorielle favorisée par l'abondance de vecteurs potentiels dans la région.Les résultats de ces différents travaux nous ont permis de présenter des hypothèses de transmission dans les différents écosystèmes de l'île et ainsi de proposer des stratégies de surveillance, de prévention et de lutte contre la FVR adaptées au contexte de Madagascar. / Rift Valley fever (RVF) is a zoonotic vector-borne disease affecting ruminants and humans. Its complex eco-epidemiology involves several species of vectors, hosts and transmission routes. These particularities allowed the circulation of RVF virus (RVFV) in a variety of ecosystems involving different transmission and emergence mechanisms. Indeed, the RVFV has affected contrasted eco-regions in Africa, Arabian Peninsula and South-West Indian Ocean islands, including Madagascar.Madagascar is considered as a continent island due to its ecological diversity and its endemicity level of the flora and the fauna. In particular, the variation of the Malagasy ecosystems (semi-arid in the south, humid and cold in the highlands, humid and warm in the north-west and per-humid in the east) has an impact in their presence and /or the relative abundance of some mosquito species. Madagascar was heavily affected by RVF in 1990-91 and 2008-2009, with evidence of a large and heterogeneous spread of the disease.Thus considering the diversity of RVF eco-epidemiological cycles and the variety of Malagasy ecosystems, we hypothesized that, in Madagascar, the mechanisms of transmission would be different according to these ecosystems. Therefore, the first objective of this thesis was to understand the mechanisms and the dynamics of transmission of RVFV in the different ecosystems. The second objective was to determine the mechanisms of emergence of RVFV and if it would be necessary and possible to predict the emergence of RVFV outbreaks according to the ecosystems.Firstly, we analyzed both cattle and human serological data performed at the national level using generalized linear mixed models to identify the environmental and behavioral factors associated with RVF transmission in both cattle and human. Secondly, we reconstructed the dynamic of transmission of RVF in the different Malagasy ecosystems. Seroprevalence data of cattle of known age were fitted using Bayesian hierarchical models to estimate the annual force of infection from 1992 to 2014. Thirdly, to understand the biological process link to the mechanisms of transmission at the national scale, we investigated the fine scale mechanisms of transmission of RVFV in pilot area of an at-risk region. We, thus, performed both longitudinal entomological and serological surveys between 2015 and 2016, in order to describe the seasonal transmission of RVFV among ruminants and its association with the dynamics of RVFV potential vectors.Our results showed that the northwestern part of Madagascar is an at-risk region for RVFV transmission. On one hand, it is characterized by high cattle densities associated with humid, floodplain and irrigated areas suitable for RVFV potential vector like Anopheles and Culex species. On the other hand, RVFV had probably circulated intensively in the region during the 1992-2007 inter-epizootic period and its transmission increased suddenly in 2007-08, almost concomitantly with the first outbreaks recorded in 2008. Finally, RVFV was still circulated in the northwestern region at low level, 6 years after the last epidemic. This circulation is likely due to vectorial transmission favoring by the abundance of several potential vectors of RVFV in this pilot region.Finally, our better understanding of the mechanisms of transmission of RVFV throughout Madagascar allowed us to propose hypothesis of transmission in different ecosystems of Madagascar and consequently refine strategies for RVF surveillance and prevention.

University of Macau / Faculty of Science and Technology. / Department of Electromechanical Engineering

by Hung Kwok Wah. / Summary in Chinese and English / Bibliography: leaves 43-46 / Thesis (M.Ph.)--Chinese University of Hong Kong, 1985

by Tam Wai Yip. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1990. / Bibliography: leaves [124]-[127] / ACKNOWLEDGEMENT --- p.i / LIST OF SYMBOLS --- p.ii / Chapter CHAPTER 1 --- INTRODUCTION --- p.1-1 / Chapter CHAPTER 2 --- ANALYSIS OF MICROSTRIP ANTENNA ON A PLANAR SURFACE --- p.2-1 / Chapter 2.1 --- Dyadic Green's function formulation of a double-patch system --- p.2-3 / Chapter 2.1.1 --- Field components --- p.2-4 / Chapter 2.1.2 --- Boundary conditions and dyadic Green's function --- p.2-8 / Chapter 2.2 --- Microstrip antenna with an airgap --- p.2-14 / Chapter 2.3 --- Microstrip antenna with a superstate --- p.2-16 / Chapter 2.4 --- Galerkin's method --- p.2-18 / Chapter 2.5 --- Numerical computation --- p.2-25 / Chapter 2.6 --- Results and discussions --- p.2-30 / Chapter CHAPTER 3 --- ANALYSIS OF MICROSTRIP ANTENNA ON SPHERICAL SURFACE --- p.3-1 / Chapter 3.1 --- Fields in spherical coordinates --- p.3-3 / Chapter 3.1.1 --- solution of scalar Helmholtz equation in spherical coordinates --- p.3-3 / Chapter 3.1.2 --- Vector potentials --- p.3-6 / Chapter 3.2 --- Cavity model approach --- p.3-10 / Chapter 3.2.1 --- Formulation of radiation patterns --- p.3-11 / Chapter 3.2.2 --- Results and discussions --- p.3-23 / Chapter 3.3 --- Spectral domain approach --- p.3-39 / Chapter 3.3.1 --- General formulation --- p.3-39 / Chapter 3.3.2 --- Complex resonant frequency --- p.3-48 / Chapter 3.3.3 --- Far field radiation pattern --- p.3-51 / Chapter 3.3.4 --- Current distribution --- p.3-52 / Chapter 3.3.5 --- Limiting case of thin dielectric --- p.3-58 / Chapter 3.3.6 --- Results and discussions --- p.3-63 / Chapter CHAPTER 4 --- CONCLUSIONS --- p.4-1 / REFERENCES / Chapter APPENDIX I --- ASSOCIATED LEGENDRE FUNCTIONS / Chapter APPENDIX II --- SPHERICAL BESSEL FUNCTIONS / Chapter APPENDIX III --- VECTOR LEGENDRE SERIES / Chapter APPENDIX IV --- RESONANT FREQUENCY RELATION FOR THIN DIELECTRIC / Chapter APPENDIX V --- LIST OF PUBLICATIONS THAT ARE PRODUCED BY THE STUDIES

Kwong Lap-ming. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 101-[104]). / Abstracts in English and Chinese. / Chapter 1 --- Introduction to Image Communication --- p.1 / Chapter 1.1 --- Existing Approach improving Image Communication --- p.8 / Chapter 1.1.1 --- Data Compression --- p.8 / Chapter 1.1.2 --- Progressive Image Transmission --- p.10 / Chapter 2 --- Review of Progressive Image Transmission Methods --- p.13 / Chapter 2.1 --- Pyramidal Image Coding --- p.14 / Chapter 2.1.1 --- Expansive Image Pyramid --- p.15 / Chapter 2.1.2 --- Non-Expansive Image Pyramid --- p.18 / Chapter 2.1.3 --- Pros and Cons of Pyramidal Data Structure --- p.19 / Chapter 2.2 --- Hierarchical Data Structure with Bit Plane Transmission --- p.20 / Chapter 2.2.1 --- Bitwise Condensed Quadtree method (BCQ)[6] --- p.21 / Chapter 2.2.2 --- Progressive Transmission of Full-Search VQ[7] --- p.25 / Chapter 2.2.3 --- Pros and Cons of Hierarchical Data Structure with Bit Plane Transmission --- p.26 / Chapter 2.3 --- Embedded Transform Coding --- p.27 / Chapter 2.3.1 --- SPIHT method [16] --- p.27 / Chapter 2.3.2 --- Embedded DCT Method [13] --- p.30 / Chapter 2.3.3 --- Pros and Cons of Embedded Transform Coding --- p.31 / Chapter 2.4 --- Summary --- p.32 / Chapter 3 --- Progressive Refinement of Colormapped Image --- p.34 / Chapter 3.1 --- Colormapped Image --- p.36 / Chapter 3.1.1 --- Pros and Cons of the Usage of Colormapped Image --- p.37 / Chapter 3.2 --- Progressive Refinement in both Spatial and Contrast Resolutions --- p.38 / Chapter 4 --- The Design of Progressive Refinement of Colormapped Image --- p.42 / Chapter 4.1 --- The Scalar Quantization in the YCrCb color space --- p.44 / Chapter 4.1.1 --- The Color Space for Color Quantization --- p.44 / Chapter 4.1.2 --- Color Quantization --- p.44 / Chapter 4.1.3 --- The Order of Quantization --- p.47 / Chapter 4.1.4 --- Pixel Mapping --- p.55 / Chapter 4.2 --- Reordering Pixels --- p.58 / Chapter 4.3 --- Transmission Sequence --- p.61 / Chapter 4.4 --- Changing the progression rate of the spatial and the contrast resolution --- p.62 / Chapter 4.5 --- Data Transmission --- p.69 / Chapter 4.6 --- Displaying the image --- p.70 / Chapter 5 --- Results Analysis & Performance Evaluation --- p.72 / Chapter 5.1 --- Traffic overhead --- p.72 / Chapter 5.2 --- Performance Evaluation --- p.73 / Chapter 5.2.1 --- Experiment --- p.73 / Chapter 5.2.2 --- Comparison with other Methods --- p.81 / Chapter 5.2.3 --- Image quality variation --- p.93 / Chapter 6 --- Discussion and Conclusion --- p.97 / Chapter 6.1 --- Discussion --- p.97 / Chapter 6.2 --- Conclusion --- p.99 / Bibliography --- p.101

Xu Bai Yu. / "August 22, 2000." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (p. [164]-169). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

by Chan Hang Fung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 62-68). / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Overview of video transmission --- p.1 / Chapter 1.2 --- Previous work on lossless video transmission --- p.4 / Chapter 1.3 --- Central theme of thesis ´ؤ Lossless video Aggregation --- p.5 / Chapter 1.4 --- Organization of thesis --- p.9 / Chapter 2 --- Framework of LVAS --- p.11 / Chapter 2.1 --- Review: Transporting single VBR stream using a CBR channel --- p.11 / Chapter 2.2 --- Lossless aggregation of VBR streams --- p.14 / Chapter 3 --- Minimization of Buffer Size --- p.17 / Chapter 3.1 --- A theoretical approach ´ؤ Dynamic programming --- p.19 / Chapter 3.2 --- A practical heuristic ´ؤ Backward Equalization --- p.21 / Chapter 3.3 --- Simulation results of the heuristic method --- p.24 / Chapter 4 --- Bit-rate allocation with fixed buffer --- p.28 / Chapter 4.1 --- Problem formulation --- p.28 / Chapter 4.2 --- Different bit-rate scheduling methods --- p.33 / Chapter 4.3 --- Speed up using point sampling technique --- p.39 / Chapter 4.4 --- Simulation results --- p.44 / Chapter 5 --- Call Admission and Interactive Control for Video Aggregation --- p.50 / Chapter 5.1 --- Call admission issues --- p.50 / Chapter 5.2 --- Interactive Control --- p.53 / Chapter 5.3 --- CBR and ABR hybrid --- p.54 / Chapter 5.4 --- Simulation results --- p.55 / Chapter 6 --- Conclusions and Future research --- p.57 / Chapter 6.1 --- Future Research Suggestions --- p.58 / Chapter 6.2 --- Publications --- p.60 / Bibliography --- p.62