Thesis advisor: Ziqiang Wang / Graphene has emerged as an important two dimensional electron system with novel physical properties due to its relativistic-like linear energy-momentum dispersion relation at low energy. Alongside two dimensional electron systems in semiconductor heterostructures, it has a rich set of integer and fractional quantum Hall states. Significant progresses have been made recently, but a full understanding of these states is still lacking. The prevailing approach for fractional quantum Hall effects in graphene has been the numerical exact diagonalization. In this work, we develop a fermionic Chern-Simons effective theory for Dirac fermions as a complement to the existing theories, and to bring new insights in our understanding of the phenomena. In particular, we study the possibility for quantum Hall plateaus at even-denominator filling factors. We first construct a unitary Chern-Simons transformation to attach even number of flux quanta to Dirac fermions. To deal with the four-fold spin-valley degeneracy, a set of K-matrices is introduced. At even-denominator filling factors in the zeroth Landau level, the fictitious magnetic field of the Chern-Simons field cancels the external magnetic field on average. It is shown that the Chern-Simons field mediates an effective mutual statistical interaction between composite Dirac fermions. We further show the statistical interaction and Coulomb interaction favor the formation of an exciton condensate. Quasi-particles at finite filling factors can be regarded as excita- tions above the exciton condensate, and can be described as massive Dirac fermions. This means a mass is generated dynamically for Dirac fermions. Different types of K-matrices give rise to different mass gaps. The Chern numbers associated with different massive Dirac band structures can be used to classify the K-matrices. In the last part of the thesis, we study the pairing instability of the composite Dirac fermion liquid. We show the statistical interaction drives a complex p-wave pairing among the quasi-particles. As long as the Coulomb pair breaking effect is weak, the system can develop a superconducting energy gap, thus form a fractional quantum Hall state. / Thesis (PhD) — Boston College, 2012. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Physics.

Thesis advisor: Krzysztof Kempa / Nonlocal effects, the wavenumber dependence in a medium's response to external disturbance, is treated in this thesis. Numerical computation methods to include nonlocal effects in plasmonic nanostructures’ electromagnetic response are discussed, and applications of plasmonics to a few other fields are elaborated. First, a computation scheme is proposed to extend conventional finite-difference time-domain (FDTD) methods to nonlocal domain. An effective film whose response is derived from Feibelman's d-function formalism is to replace the highly non-uniform metal surfaces in simulations. It successfully produces numerical results of plasmonic resonance shift and field enhancement which agrees with the experimental data to first order. This scheme is still classical, thus very fast compared to the other first principle quantum methods such as density functional theory. Then electron's scattering rate in an effective medium with plasmonic nanostructures embedded-in, in random phase approximation, is developed, with the wavenumber dependence in the medium’s response accounted. Utilizing this calculation scheme of electron’s scattering rate, further specific applications are following. We show by simulation of the plasmonic nanostructures and calculation of the electron scattering rates that hot-electron plasmon-protection (HELPP) effects can protect the extra energy of hot electrons from being dissipated as heat. This can be a prototype of the 3rd generation solar cells. In another application, we investigate the electron polar-optical-phonon (POP) scattering in heavily-doped semiconductors when plasmonic nanostructures are embedded-in. We show that electron-POP scattering can be significantly suppressed compared to that of bulk semiconductors. In the third application, we propose the plasmonic multiple exciton generation (PMEG) scheme, with simulations and calculations, showing that the efficiency of multiple exciton generation in conventional semiconductors could be enhanced significantly with proper designed plasmonic nanostructures embedded-in or attached-adjacent. / Thesis (PhD) — Boston College, 2018. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Physics.

MA, Faculty of Arts, University of the Witwatersrand, 2001

MSc (Med) Molecular Medicine and Haematology, Faculty of Health Sciences, University of the Witwatersrand, 2009 / This is the third phase of a project to identify, confirm, and operationalise biomarkers for crystalline silica dust exposure that could be used for surveillance of dust exposure levels in South African mines. The first phase of the project involved a comprehensive review of the relevant literature [Gulumian et al., 2006] from which ten potential biomarkers of effect were identified as being worthy of further investigation. The second phase of the project examined the ten identified biomarkers in silica dust-exposed and unexposed black male subjects [Murray et al., 2006]. Two of the ten short listed biomarkers, namely erythrocyte glutathione peroxidase (GPx) and serum Clara cell protein 16 (CC16), were found to have significantly reduced levels in the silica dust-exposed versus unexposed subjects. In addition, the biomarkers were found to be unaffected by HIV sero-status, smoking, age and the presence of silicosis. As a result, this third phase of the project aimed to confirm the levels of and further analyze GPx and CC16 in miners exposed to crystalline silica dust. This third phase involved the measurement of the levels of erythrocyte GPx and serum CC16 in 80 adult male gold miners upon their return from leave and then again two to six months after they had returned to work (involving exposure to crystalline silica). Before the field work was conducted, however, the optimal operational parameters for the biomarkers (namely storage temperature, delay in time between blood collection and separation, laboratory temperature and storage duration) were established. The results of these optimization experiments were used to develop Standard Operating Procedures (SOPs) for biomarker specimen handling and storage under field conditions, and for laboratory assays. In this phase, the findings of the second phase were confirmed in that the levels of GPx and CC16 were lowered in miners exposed to crystalline silica dust and were unaffected by age, race and cigarette smoking. In addition, while CC16 was unaffected by the presence of radiological silicosis, GPx may have been affected. Finally, the decrease in the levels of GPx activity and CC16 concentration observed in the study were unaffected by the level of silica dust exposure (high or low) as determined by job category or by the duration of crystalline silica exposure. Regarding the levels of GPx activity, the results suggested that GPx levels decrease after two to six months of chronic exposure to crystalline silica dust and remain decreased (throughout the working week and over a weekend) and then increase or even recover to normal levels during a period of leave. It was therefore concluded that GPx activity levels rise and fall, in response to silica dust exposure, gradually and over periods of some time, possibly months. The CC16 results were, however, less promising. After two to six months of chronic exposure to crystalline silica dust there was a significant change in CC16 on a Wednesday afternoon following an 8-hour shift and during the duration of a shift. In addition, there is the possibility that the observed changes were due to a time-dependent diurnal variation in the CC16 levels. It was concluded that the results of the current phase warrant further research into the use of erythrocyte GPx and serum CC16 as biomarkers of early effect from crystalline silica exposure.

The teratogenic effects of prenatal alcohol exposure can significantly influence the development of a child, which may result in a range of structural, cognitive and behavioural abnormalities. The severity of these effects can vary and fall under the fetal alcohol spectrum disorder (FASD). South Africa hosts the highest prevalence rate (12%) of this disorder in the world. All conditions included in the FASD spectrum are completely preventable through maternal abstinence of alcohol during pregnancy. At present, very limited information is available regarding how much pregnant women in South Africa know about adverse effects caused by prenatal alcohol exposure. This study aimed to determine pregnant women’s awareness of alcohol’s potential teratogenic effects on pregnancy and their knowledge of the features and characteristics associated with fetal alcohol syndrome (FAS), the most severe of the FASD conditions. Additionally, the study compared the awareness and knowledge of pregnant women attending private antenatal centres, to those attending an antenatal clinic at Charlotte Maxeke Johannesburg Academic Hospital, a state hospital in the Johannesburg area. Participants (n=211) completed a self-administered questionnaire at their private antenatal class or state clinic. A total of 211 questionnaires were analysed; 107 questionnaires from the state antenatal clinic and 104 from the private antenatal centres. The awareness levels regarding alcohol use in pregnancy were found to be very similar amongst the private (52%) and state (55%) participants. However, results indicated that significantly more private participants (19%), compared to state participants (3%) could be classified as having knowledge of the condition FAS. Overall, this study found that pregnant women from various backgrounds have limited knowledge of the harms caused by alcohol use during pregnancy. Misconceptions about the acceptable levels of maternal alcohol consumption and the effects thereof were also evident. The results of this research highlights that prevention strategies and awareness campaigns regarding alcohol use during pregnancy should incorporate information on the severity and permanent nature of FAS, as well as highlighting the fact that all types of alcoholic beverages can result in this condition. Also, these campaigns should focus on informing women that no level of alcohol is acceptable during pregnancy, as any amount may have potentially teratogenic effects on the developing fetus.

Faculty of Humanities; School of Human and Community development; MA Research Report / Social participation is one of the most debilitating effects of aphasia. Yet, to date no clear definitions or models of social participation have been developed that can be applied within aphasiology. In addition, generic stroke scales are still the outcome measures of choice within research. There is a need for patient-centred measures that accurately document and assess the experiences and perceptions of those with aphasia. Therefore, the current research aimed to investigate the social participation of adults with aphasia by extending patient-centred measures and encompassing the views of the families, particularly the spouses, of those with aphasia. Four crosssectional parallel single case studies were conducted that involved a protocol combining the quantitative measure of the ASHA FACS with the qualitative tools of semi-structured interviews and observations. In addition, social network analyses were completed for each participant. Overall, open coding of the individual participants’ results produced common themes among the people with aphasia and common themes among their spouses. Each participant reported significantly altered social participation, which permeated throughout the family unit and was felt considerably by the spouses of those with aphasia. The results are discussed in relation to current social models and approaches to intervention, while professional role expansion and the needs of the South African context are also considered. Furthermore, the concept of resilience and its implications for future research are discussed.

by Ai-Dong Qi. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (p. 219-256). / 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.

by Ho Iok Ieng Yolanda. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (p. 116-132). / 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 Ho Ka-Pong, Bosco. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 81-100). / Chapter CHAPTER 1: --- INTRODUCTION --- p.1 / Chapter CHAPTER 2: --- PURIFICATION OF HUMAN CLASS I LIVER ADH --- p.19 / Chapter CHAPTER 3: --- DISSOCIATION AND REASSOCIATION OF HUMAN CLASS I ADH BY FREEZE/THAW TECHNIQUE --- p.36 / Chapter CHAPTER 4: --- "DISSOCIATION AND REASSOCIATION OF HUMAN CLASS I ADH BY USING UREA, GdmCl,HIGH SALT AND LOW pH" --- p.51 / Chapter CHAPTER 5: --- GENERAL DISCUSSION --- p.77 / REFERENCES --- p.81

by Lam Heung-wah, Angora. / Thesis (M. Phil.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 124-131). / ACKNOWLEDGEMENTS --- p.iv / ABSTRACT --- p.v / LIST OF ABBREVIATIONS --- p.vii / LIST OF TABLES --- p.viii / LIST OF FIGURES --- p.ix / INTRODUCTION --- p.1 / LITERATURE REVIEW --- p.4 / Chapter A. --- Some Aspects of Cardiovascular Physiology and Pharmacology --- p.4 / Chapter I. --- Fundamental Principles Governing regulation of Arterial Pressure --- p.4 / Chapter II. --- Hypertension --- p.12 / Chapter III. --- Antihypertensive Substances --- p.16 / Chapter B. --- Mushrooms and Their Medicinal Values --- p.29 / Chapter I. --- "The Straw Mushroom, V. volvacea" --- p.29 / Chapter II. --- "Mushrooms, Blood Pressure, and Related Changes" --- p.32 / MATERIALS AND METHODS --- p.39 / Chapter A. --- Basic Preparative Procedures --- p.39 / Chapter I. --- Preparation of Straw Mushroom Extract (SME) --- p.39 / Chapter II. --- Purification of SME by Dialysis --- p.40 / Chapter III. --- Preparation for In vivo Blood Pressure Measurement in Rats --- p.40 / Chapter IV. --- preparation of Right Atrium for In vitro Studies --- p.41 / Chapter V. --- Preparation of Artery Strip for In vitro Studies --- p.42 / Chapter B. --- Experiments Done --- p.43 / Chapter Experiment 1. --- Toxicity of SME --- p.43 / Chapter Experiment 2. --- Hypotensive Effect of SME and Dialyzed Samples --- p.44 / Chapter Experiment 3. --- Pharmacological Antagonist Studies --- p.45 / Chapter Experiment 4. --- Effect of Autonomic Ganglion Blocker and Alpha Blocker on Hypotensive Changes Induced by SME --- p.47 / Chapter Experiment 5. --- Study on Renin-Angiotensin and Kinin Systems --- p.48 / Chapter Experiment 6. --- Urinary and Sodium Excretion in Water-loaded Rats --- p.48 / Chapter Experiment 7. --- Chronotropic and Inotropic Studies on Isolated Right Atria --- p.49 / Chapter Experiment 8. --- Contractile Responses of SME & Its Dialyzed Samples on Rat Tail Artery Strips --- p.50 / Chapter Experiment 9. --- Effect of Adrenergic Blockers in SME Preconstricted Strips --- p.51 / Chapter Experiment 10. --- Acute Oral Effect of DUL8000 and DLL8000 from SME on Blood Pressure --- p.51 / Chapter Experiment 11. --- "Chronic Oral Effect of SME on Blood Pressure, Total Free Cholesterol and Triglyceride Levels" --- p.52 / Chapter C. --- Statistics --- p.55 / RESULTS --- p.56 / Chapter A. --- Toxicity of Straw Mushroom Extract (SME) --- p.56 / Chapter B. --- Effects of SME in Normotensive Rats --- p.56 / Chapter I. --- Blood Pressure Changes --- p.56 / Chapter II. --- Pharmacological Antagonists Studies --- p.58 / Chapter III. --- Converting Enzyme Activity --- p.60 / Chapter IV. --- Urinary and Sodium Excretion --- p.60 / Chapter V. --- In vitro Arterial and Cardiac Effects --- p.61 / Chapter C. --- Cardiovascular Effects of Dialyzed Samples of SME (Molecular Mass cutoffl2000) in Spontaneously Hypertensive Rats (SHR) and Normotensive Rats --- p.61 / Chapter I. --- Blood Pressure Changes --- p.61 / Chapter II. --- In vitro Arterial and Cardiac Effects --- p.62 / Chapter D. --- Cardiovascular Effects of Dialyzed Samples (DUL8000 and DLL8000) in Spontaneously Hypertensive Rats (SHR) and Normotensive Rats --- p.63 / Chapter I. --- Blood Pressure Changes --- p.63 / Chapter II. --- In vitro Arterial and Cardiac Effects --- p.65 / Chapter E. --- The Acute Oral Effect of SME on Blood Pressure --- p.68 / Chapter F. --- "Chronic Dietary Effect of SME on Blood Pressure, Total Free Serum Cholesterol and Triglyceride Levels" --- p.68 / DISCUSSION --- p.109 / Chapter A. --- The Hypotensive Effect of SME --- p.109 / Chapter B. --- The Hypotensive Action of SME: Mechanism of Action --- p.110 / Chapter C. --- The Cardiovascular Active Fractions in SME --- p.113 / Chapter D. --- "The Cardiovascular Effect of DUL8000 and DLL8000 in Rats with Reference to Age, Sex and Strains" --- p.115 / Chapter E. --- The Oral Effect of SME on Blood Pressure and on Serum Cholesterol and Triglyceride Levels --- p.118 / SUMMARY --- p.121 / REFERENCES --- p.124 / APPENDIXES --- p.132