Characterising population variability in brain structure through models of whole-brain structural connectivity

Models of whole-brain connectivity are valuable for understanding neurological function. This thesis seeks to develop an optimal framework for extracting models of whole-brain connectivity from clinically acquired diffusion data. We propose new approaches for studying these models. The aim is to develop techniques which can take models of brain connectivity and use them to identify biomarkers or phenotypes of disease. The models of connectivity are extracted using a standard probabilistic tractography algorithm, modified to assess the structural integrity of tracts, through estimates of white matter anisotropy. Connections are traced between 77 regions of interest, automatically extracted by label propagation from multiple brain atlases followed by classifier fusion. The estimates of tissue integrity for each tract are input as indices in 77x77 ”connectivity” matrices, extracted for large populations of clinical data. These are compared in subsequent studies. To date, most whole-brain connectivity studies have characterised population differences using graph theory techniques. However these can be limited in their ability to pinpoint the locations of differences in the underlying neural anatomy. Therefore, this thesis proposes new techniques. These include a spectral clustering approach for comparing population differences in the clustering properties of weighted brain networks. In addition, machine learning approaches are suggested for the first time. These are particularly advantageous as they allow classification of subjects and extraction of features which best represent the differences between groups. One limitation of the proposed approach is that errors propagate from segmentation and registration steps prior to tractography. This can cumulate in the assignment of false positive connections, where the contribution of these factors may vary across populations, causing the appearance of population differences where there are none. The final contribution of this thesis is therefore to develop a common co-ordinate space approach. This combines probabilistic models of voxel-wise diffusion for each subject into a single probabilistic model of diffusion for the population. This allows tractography to be performed only once, ensuring that there is one model of connectivity. Cross-subject differences can then be identified by mapping individual subjects’ anisotropy data to this model. The approach is used to compare populations separated by age and gender

The Urbanization of Social Justice Through Gender Mainstreaming in Vienna, Austria

The goal of this thesis is to evaluate different attempts at formulating a theory for how social justice can be achieved in cities. This evaluation is important because the physical elements that make up the design of cities and the people who make the decisions about how to allocate design elements within cities heavily influences the sources of injustice in cities. As such, theories of achieving social justice in cities provide ideas about what aspects of city design produce injustices and how the production of injustice can be mitigated. Chapter 1 identifies theories of social justice that have been part of the conversation about how to implement social justice measures in cities. Chapter 2 discusses spatial justice and the way social justice enters the physical design of cities through spatial planning. Chapter 3 then provides a case study of how social justice has been addressed through the form of gender mainstreaming in Vienna, Austria. Chapter 4 analyzes how the case study is used to demonstrate the ways in which different urban theories can work off of one another to make more just cities. The overall purpose of this thesis is to show how individual social justice theories do not have to present all of the possible ways to achieve more just cities. Rather, a combination of different elements from different theories allows for a more targeted approach to achieving social justice, as the selected elements can be related directly to the situation being addressed.Humanitie

Experiences of seeking support from health services in the context of homelessness and alcohol dependence

The portfolio thesis is comprised of three parts: a systematic literature review, an empirical paper, and supporting appendices.Part one is a systematic literature review, exploring the themes that represent the experiences of people experiencing homelessness in the context of seeking help from UK health services. Twenty-two articles were critically quality assessed, and a thematic synthesis was performed to analyse and synthesise the findings. There were three super-ordinate themes generated which represented positive and negative experiences of help-seeking for people experiencing homelessness at the individual, service, and social-contextual levels. Implications for services, policy and future research are outlined to facilitate people experiencing homelessness seeking health support.Part two is an empirical paper, exploring the role of alcohol and what helps and hinders access to alcohol treatment for people experiencing homelessness and alcohol dependence. A sample of seven participants, combining people experiencing homelessness and alcohol dependence and outreach and key workers, engaged with semi-structured interviews. Interviews were thematically analysed to identify five themes describing the role of alcohol and the capability, opportunity and motivation factors that help and hinder access to alcohol treatment for people experiencing homelessness and alcohol dependence. Clinical and research implications are discussed to aid engagement with people experiencing homelessness and alcohol dependence.Part three accumulates the appendices that accompany the systematic literature review and the empirical paper, including a reflective statement and epistemological statement to inform the context of the thesis portfolio

Public actors or private providers?: NGOs, Health Sector Reform and Community Based Health Care in Tanzania

The thesis poses two main questions: ‘what are NGOs?’ and ‘where do NGOs fit in?’. Taking the World Development Report of 1993 as the articulation of an international Health Sector Reform (HSR) agenda, the thesis questions the depiction of NGOs as private health service providers. Identifying four themes as key to the conceptualisation, design and implementation of HSR, it reflects on how these themes have been treated in health and development policy and practice. The thesis proposes that the ethos, programmes and actions of NGOs in health shed light on the interpretation of‘private*, ‘health’, ‘decentralisation’ and ‘community’ in ways that uncover important assumptions and contradictions inherent in the HSR agenda. It proposes that rather than taking NGOs to be private health service providers fitting neatly into increasingly market-based health systems, further exploration of the activist and advocacy role of NGOs is justified. Investigating HSR in Tanzania, the thesis shows that the dominant view of NGOs is as private service providers, but that, despite recognition of this role, NGOs have been largely excluded from policy discussions. The thesis takes Community Based Health Care (CBHC) - identified in the HSR policy documents and referred to by NGOs - as a case through which to explore the notion that NGOs are ‘community activists’, with a significance beyond direct health service provision. Promotion of CBHC by NGOs shows how they work in and around the formal health sector, at national, local government, and community levels. It concludes that whether providing primary health services, supporting selective primary health interventions, or promoting comprehensive empowerment-oriented approaches to primary health care, NGOs are embedded in complex processes of defining and meeting ‘public’ need. This merits the reconceptualisation of NGOs as public actors constantly defining, maintaining and developing their role through engagement in networks of public action

Getting the picture : iconicity does not affect representation-referent confusion

Three experiments examined 3- to 5-year-olds' (N = 428) understanding of the relationship between pictorial iconicity (photograph, colored drawing, schematic drawing) and the real world referent. Experiments 1 and 2 explored pictorial iconicity in picture-referent confusion after the picture-object relationship has been established. Pictorial iconicity had no effect on referential confusion when the referent changed after the picture had been taken/drawn (Experiment 1) and when the referent and the picture were different from the outset (Experiment 2). Experiment 3 investigated whether children are sensitive to iconicity to begin with. Children deemed photographs from a choice of varying iconicity representations as best representations for object reference. Together, findings suggest that iconicity plays a role in establishing a picture-object relation per se but is irrelevant once children have accepted that a picture represents an object. The latter finding may reflect domain general representational abilities