Quantum Features of the Cosmological Horizon

This thesis explores the thermodynamics of the cosmological horizon, aiming to make progress towards a better understanding of the microscopic nature of its entropy. We utilise the constrained nature of low-dimensional gravity to do so and investigate timelike boundaries in these theories, with an emphasis on the stretched horizon holographic picture. Given the success of AdS/CFT, one might try to embed de Sitter inside anti-de Sitter and describe the expanding region from the boundary. In two dimensions, such geometries exist and, by studying them in the presence of a timelike boundary, we find thermally stable solutions. We thus propose a dual matrix model that should describe this geometry, including the expanding region. One way to test this duality would be to compare bulk and boundary correlators. However, for de Sitter this poses a puzzle: in the saddle point approximation two-point functions are given by a sum over geodesics. Such correlation functions exist for any two arbitrary points in de Sitter, but geodesics do not. This is resolved by including complex saddles that appear upon Wick rotating from the sphere. Additionally, one can use the relationship between three-dimensional gravity and Chern-Simons theory to explore thermodynamic contributions to the de Sitter horizon. The Euclidean gravitational path integral provides the exact, all-loop quantum corrected de Sitter entropy. To understand the microscopic origin of this entropy, one hopes to find an analogous Lorentzian calculation that produces this result. This takes the form of an edge-mode theory living close to the cosmological horizon with a complexified gauge group, leading to an unbounded spectrum. To make progress, we study a comparable Abelian theory that leads to an entropy with an entanglement character. Finally, we summarise some new results on edge-mode theories arising from general boundary conditions.Comment: PhD thesis, King's College London. 159 pages, 18 figure

A study in vertical symmetry.

n/

The Episcopal Congregation of Charlotte Chapel, Edinburgh, 1794-1818

This thesis reassesses the nature and importance of the Scottish Episcopal Church in Edinburgh and more widely. Based on a microstudy of one chapel community over a twenty-four year period, it addresses a series of questions of religion, identity, gender, culture and civic society in late Enlightenment Edinburgh, Scotland, and Britain, combining ecclesiastical, social and economic history. The study examines the congregation of Charlotte Episcopal Chapel, Rose Street, Edinburgh, from its foundation by English clergyman Daniel Sandford in 1794 to its move to the new Gothic chapel of St John's in 1818. Initially an independent chapel, Daniel Sandford's congregation joined the Scottish Episcopal Church in 1805 and the following year he was made Bishop of Edinburgh, although he contined to combine this role with that of rector to the chapel until his death in 1830. Methodologically, the thesis combines a detailed reassessment of Daniel Sandford's thought and ministry (Chapter Two) with a prosopographical study of 431 individuals connected with the congregation as officials or in the in the chapel registers (Chapter Three). Biography of the leader and prosopography of the community are brought to illuminate and enrich one another to understand the wealth and business networks of the congregation (Chapter Four) and their attitudes to politics, piety and gender (Chapter Five). The thesis argues that Daniel Sandford's Evangelical Episcopalianism was both original in Scotland, and one of the most successful in appealing to educated and influential members of Edinburgh society. The congregation, drawn largely from the newly-built West End of Edinburgh, were bourgeois and British in their composition. The core membership of privileged Scots, rooted in land and law, led, but were also challenged by and forced to adapt to a broad social spread who brought new wealth and influence into the West End through India and the consumer boom. The discussion opens up many avenues for further research including the connections between Scottish Episcopalianism and romanticism, the importance of India and social mobility within the consumer economy in the development of Edinburgh, and Scottish female intellectual culture and its engagement with religion and enlightenment. Understanding the role of enlightened, evangelical Episcopalianism, which is the contribution of this study, will form an important context for these enquiries

intraoperative Radiotherapy for Breast Cancer

Intraoperative radiotherapy (IORT) for early stage breast cancer is a technique for partial breast irradiation. There are several technologies in clinical use to perform breast IORT. Regardless of technique, IORT generally refers to the delivery of a single dose of radiation to the periphery of the tumor bed in the immediate intraoperative time frame, although some protocols have performed IORT as a second procedure. There are two large prospective randomized trials establishing the safety and efficacy of breast IORT in early stage breast cancer patients with sufficient follow-up time on thousands of women. The advantages of IORT for partial breast irradiation include: direct visualization of the target tissue ensuring treatment of the high-risk tissue and eliminating the risk of marginal miss; the use of a single dose coordinated with the necessary surgical excision thereby reduc- ing omission of radiation and the selection of mastectomy for women without access to a radiotherapy facility or unable to undergo several weeks of daily radiation; favorable toxicity profiles; patient convenience and cost savings; radiobiological and tumor micro- environment conditions which lead to enhanced tumor control. The main disadvantage of IORT is the lack of final pathologic information on the tumor size, histology, margins, and nodal status. When unexpected findings on final pathology such as positive margins or positive sentinel nodes predict a higher risk of local or regional recurrence, additional whole breast radiation may be indicated, thereby reducing some of the convenience and low-toxicity advantages of sole IORT. However, IORT as a tumor bed boost has also been studied and appears to be safe with acceptable toxicity. IORT has potential efficacy advantages related to overall survival related to reduced cardiopulmonary radia- tion doses. It may also be very useful in specific situations, such as prior to oncoplastic reconstruction to improve accuracy of adjuvant radiation delivery, or when used as a boost in higher risk patients to improve tumor control. Ongoing international clinical trials are studying these uses and follow-up data are accumulating on completed studies

Optimization of Adjuvant Radiation in Breast Conservation Therapy: Can We Minimize without Compromise?

Adjuvant breast radiation therapy after breast conservation surgery is recommended as it yields significant reduction in the risk of local recurrence, and confers a potential overall survival benefit. Although the standard breast radiation regimen has historically been delivered over 5–7 weeks; more novel, shorter courses of breast radiation are currently being employed, offering the advantage of more convenience and less time-commitment. Herein, we review the recent literature substantiating these abbreviated radiation treatment approaches and the methods of delivery thereof. In addition, we discuss imaged guided techniques currently being utilized to further refine the delivery of adjuvant breast radiation therapy

Research Process Analysis of a Survey on Access to HIV/AIDS Care among Health Care Workers in Swaziland

In October 2007 the Swaziland Nursing Association (SNA), in collaboration with the South African Human Capacity Development Project (SA-HCD) and the Capacity Project - IntraHealth International, came together to conduct a survey on the „Access to HIV/AIDS care among health care workers in Swaziland.‟ The research stemmed from the observation of high rates of HIV/ AIDS fear and stigma among health workers, poor utilization of HIV care and support facilities by these health care workers, and health workers‟ concerns regarding breach of confidentiality. The objectives of the survey were largely two-fold: a. To assess health care workers‟ knowledge and access to work place HIV/AIDS infection prevention and control and to determine the barriers to receiving HIV/AIDS care and support by health care workers and their families. b. To use the knowledge obtained from the survey in a targeted intervention to reduce potential barriers to HIV/AIDS care among health care workers. The aim of this paper, written before the data analysis, is to present a descriptive analysis of the research process, critically analyze the research methods, and discuss possible strengths and limitations of the methods and the implications for further research. Analysis of the methods showed that like all research processes, the HCW survey is not without its strengths and biases. Methodological challenges such as contextual documentation, sampling, and time and human resource constraints were all factors that played into the research process and are important factors to be considered in the data analysis and results interpretations. The importance of community participatory approaches and training were found to have been great initiatives in the research process by way of the commitment, depth and ownership it imparted to the study. Additionally, the relevance of knowledge and awareness of the research context was highlighted in the quality imparted to the data collection processes. Based on this research process analysis, the need for the involvement of the survey implementers (nurses) in the data analysis and results interpretation is greatly emphasized in their ability to enhance the validity and reliability of the studies findings. In conclusion, capturing all aspects of the qualitative research process is imperative in ensuring in-depth understanding of the research data. It is hoped that information obtained from this research analysis will not only inform the data analysis and results write up of the health care workers‟ survey but also serve as a resource tool for future practice. The longer term goal of which would be that, subsequent interventions can build upon the information, to contribute to the establishment of a much needed resource data base for best practices in qualitative research development in the Kingdom of Swaziland.Master of Public Healt

Does self-control improve with practice? Evidence from a 6-week training program

Can self-control be improved through practice? Several studies have found that repeated practice of tasks involving self-control improves performance on other tasks relevant to self-control. However, in many of these studies, improvements after training could be attributable to methodological factors (e.g., passive control conditions). Moreover, the extent to which the effects of training transfer to real-life settings is not yet clear. In the present research, participants (N = 174) completed a 6-week training program of either cognitive or behavioral self-control tasks. We then tested the effects of practice on a range of measures of self-control, including lab-based and real-world tasks. Training was compared to both active and no-contact control conditions. Despite high levels of adherence to the training tasks, there was no effect of training on any measure of self-control. Trained participants did not, for example, show reduced ego depletion effects, become better at overcoming their habits, or report exerting more self-control in everyday life. Moderation analyses found no evidence that training was effective only among particular groups of participants. Bayesian analyses suggested that the data was more consistent with a null effect of training on self-control than with previous estimates of the effect of practice. The implication is that training self-control through repeated practice does not result in generalized improvements in self-control

‘Chaucer’s World’ study days in Oxford for post-16 students: enhancing learning and encouraging wonder

This collaborative essay, structured as a collection of tales akin to Chaucer’s, provides a multiperspectival reflection on enhancement study days, entitled ‘Chaucer’s World’, co-organised by the University of Oxford, the Ashmolean Museum, the Bodleian Library, and secondary schools from the area. The event is aimed at UK secondary school students in their final two years of study, and is intended not only to help students with their preparation for the A-Level English Literature exam but also to instil in them appreciation for Chaucer’s works, as well as for medieval literature and culture in general

A Model of Tuberculosis Screening for Pregnant Women in Resource-Limited Settings Using Xpert MTB/RIF

Timely diagnosis and treatment of maternal tuberculosis (TB) is important to reduce morbidity and mortality for both the mother and child, particularly in women who are coinfected with HIV. The World Health Organization (WHO) recommends the integration of TB/HIV screening into antenatal services but available diagnostic tools are slow and insensitive, resulting in delays in treatment initiation. Recently the WHO endorsed Xpert MTB/RIF, a highly sensitive, real-time PCR assay for Mycobacterium tuberculosis that simultaneously detects rifampicin resistance directly from sputum and provides results within 100 minutes. We propose a model for same-day TB screening and diagnosis of all pregnant women at antenatal care using Xpert MTB/RIF. Pilot studies are urgently required to evaluate strategies for the integration of TB screening into antenatal clinics using new diagnostic technologies

A model of tuberculosis screening for pregnant women in resource-limited settings using Xpert MTB/RIF

Timely diagnosis and treatment of maternal tuberculosis (TB) is important to reduce morbidity and mortality for both the mother and child, particularly in women who are coinfected with HIV. TheWorld Health Organization (WHO) recommends the integration of TB/HIV screening into antenatal services but available diagnostic tools are slow and insensitive, resulting in delays in treatment initiation. Recently the WHO endorsed Xpert MTB/RIF, a highly sensitive, real-time PCR assay for Mycobacterium tuberculosis that simultaneously detects rifampicin resistance directly from sputum and provides results within 100 minutes. We propose a model for same-day TB screening and diagnosis of all pregnant women at antenatal care using Xpert MTB/RIF. Pilot studies are urgently required to evaluate strategies for the integration of TB screening into antenatal clinics using new diagnostic technologies