6,132 research outputs found

    The Influence of Neuroendocrine and Genetic Markers of Stress on Cognitive Processing and Intrusive Symptoms

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    This body of research investigated the influence of neuroendocrine and genetic elements of arousal on cognitive processes in the development of intrusive memories and flash-forward intrusions as related to Post-Traumatic Stress Disorder. Specifically, this thesis investigated various mechanisms that may underlie intrusive symptoms as postulated by prevalent theories of PTSD. Study 1 examined the distinctive relationship between peritraumatic dissociation and subsequent re-experiencing symptoms. Network analyses revealed strong positive edges between peritraumatic dissociation and subsequent amnesia, as well as the re-experiencing symptoms of physical reactivity to reminders, flashbacks, intrusions, and dreams, and to a lesser extent emotional numbness and hypervigilance. The finding that peritraumatic dissociation is related to subsequent re-experiencing symptoms is consistent with cognitive models that emphasize the role of dissociative experiences during a traumatic event in the etiology of PTSD re-experiencing symptoms. Study 2 aimed to determine whether peri-traumatic stress, as measured via salivary cortisol and salivary alpha-amylase, as well as pre-existing genetic polymorphisms on the FKBP5 gene increased dissociation and data-driven processing, and subsequently impacted intrusive memories related to a trauma film. The findings revealed that greater noradrenergic arousal predicted less intrusive memory distress in individuals who scored higher on data-driven processing and trait dissociation, and in FKBP5 low-risk carriers. For individuals who reported less data-driven processing and trait dissociation, and in FKBP5 high-risk carriers, as noradrenergic arousal increased, intrusive memory distress increased. This study also showed no association between data-driven processing with memory fragmentation, and fragmentation with intrusive memories. Whilst these findings support some aspect of cognitive models of PTSD as they indicate a role for data-driven processing and dissociation in intrusive symptoms, they highlight a threshold at which these variables stop moderating the relationship between arousal and intrusive memories and suggest that memory fragmentation is not related to intrusive memories. Study 3 examined the role of cognitive control in flash-forward intrusions in the context of an enduring stressor, the COVID-19 pandemic. In line with expectations, results showed that as cognitive control worsened, FKBP5 high-risk carriers reported more flash-forward distress, and low-risk carriers reported less distress. These findings are considered in the context of hippocampal changes and are consistent with emerging theories of PTSD. Lastly, study 4 sought to investigate the role of two neurological processes, pattern separation and pattern completion in intrusive memories in individuals with PTSD compared to trauma exposed controls. Consistent with existing literature, the data indicate that individuals with PTSD reported more data-driven processing, more intrusive symptoms, and demonstrated better behavioural pattern completion than trauma-exposed controls. These findings are in line with current cognitive models of PTSD, as they again indicate a role for data-driven processing in PTSD. However, study 4 found no support for the postulate that deficient pattern separation is a feature of PTSD and found an opposite effect for the role of pattern completion. Whilst these findings are inconsistent with theory, they are in line with existing experimental studies. Overall, the findings from this thesis provide insight into cognitive and biological models of PTSD and shed light on the mechanisms underlying the nature and development of intrusive symptoms

    Beam scanning by liquid-crystal biasing in a modified SIW structure

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    A fixed-frequency beam-scanning 1D antenna based on Liquid Crystals (LCs) is designed for application in 2D scanning with lateral alignment. The 2D array environment imposes full decoupling of adjacent 1D antennas, which often conflicts with the LC requirement of DC biasing: the proposed design accommodates both. The LC medium is placed inside a Substrate Integrated Waveguide (SIW) modified to work as a Groove Gap Waveguide, with radiating slots etched on the upper broad wall, that radiates as a Leaky-Wave Antenna (LWA). This allows effective application of the DC bias voltage needed for tuning the LCs. At the same time, the RF field remains laterally confined, enabling the possibility to lay several antennas in parallel and achieve 2D beam scanning. The design is validated by simulation employing the actual properties of a commercial LC medium

    Machine Learning Research Trends in Africa: A 30 Years Overview with Bibliometric Analysis Review

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    In this paper, a critical bibliometric analysis study is conducted, coupled with an extensive literature survey on recent developments and associated applications in machine learning research with a perspective on Africa. The presented bibliometric analysis study consists of 2761 machine learning-related documents, of which 98% were articles with at least 482 citations published in 903 journals during the past 30 years. Furthermore, the collated documents were retrieved from the Science Citation Index EXPANDED, comprising research publications from 54 African countries between 1993 and 2021. The bibliometric study shows the visualization of the current landscape and future trends in machine learning research and its application to facilitate future collaborative research and knowledge exchange among authors from different research institutions scattered across the African continent

    'Exarcheia doesn't exist': Authenticity, Resistance and Archival Politics in Athens

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    My thesis investigates the ways people, materialities and urban spaces interact to form affective ecologies and produce historicity. It focuses on the neighbourhood of Exarcheia, Athens’ contested political topography par excellence, known for its production of radical politics of discontent and resistance to state oppression and eoliberal capitalism. Embracing Exarcheia’s controversial status within Greek vernacular, media and state discourses, this thesis aims to unpick the neighbourhoods’ socio-spatial assemblage imbued with affect and formed through the numerous (mis)understandings and (mis)interpretations rooted in its turbulent political history. Drawing on theory on urban spaces, affect, hauntology and archival politics, I argue for Exarcheia as an unwavering archival space composed of affective chronotopes – (in)tangible loci that defy space and temporality. I posit that the interwoven narratives and materialities emerging in my fieldwork are persistently – and perhaps obsessively – reiterating themselves and remaining imprinted on the neighbourhood’s landscape as an incessant reminder of violent histories that the state often seeks to erase and forget. Through this analysis, I contribute to understandings of place as a primary ethnographic ‘object’ and the ways in which place forms complex interactions and relationships with social actors, shapes their subjectivities, retains and bestows their memories and senses of historicity

    Conscience and Consciousness: British Theatre and Human Rights.

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    This research project investigates a paradigm of human rights theatre. Through the lens of performance and theatre-making, this thesis explores how we came to represent, speak about, discuss, and own human rights in Britain. My framework of ‘human rights theatre’ proposes three distinctive features: firstly, such works dramatise real-world issues and highlights the role of the state in endangering its citizens; secondly, ethical ruptures are encountered within and without the drama, and finally, these performances characteristically aspire to produce an activist effect on the collective behaviours of the audience. This thesis interrogates the strategies theatre-makers use to articulate human rights concerns or to animate human rights intent. The selected case-studies for this investigation are ice&fire’s testimonial project, Actors for Human Rights; Badac Theatre; Jonathan Holmes’ work as director of Jericho House; Cardboard Citizens’ youth participation programme, ACT NOW; and Tony Cealy’s Black Men’s Consortium. Deliberately selecting companies and performance events that have received limited critical attention, my methodology constellates case-studies through original interviews, durational observation of creative working methods and proximate descriptions of practice. The thesis is interested in the experience of coming to ‘consciousness’ through human rights theatre, an awakening to the impacts of rights infringements and rights claiming. I explore consciousness as a processual, procedural, and durational happening in these performance events. I explore the ‘éffect’ of activist art and examine the ways in which makers of human rights theatre aim to amplify both affective and effective qualities in their work. My thesis also considers the articulation of activist purpose and the campaigning intent of the selected theatre-makers and explores how their activism is animated in their productions. Through the rich seam of discussion generated by the identification and exploration of the traits of a distinctive human rights theatre, I affirm the generative value of this typological enquiry

    The new age of fear: an analysis of crisis framing by right-wing populist parties in Greece and France

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    From the 2009 Eurozone economic downturn, to the 2015 mass movement of forcibly displaced migrants and the current COVID-19 pandemic, crises have seemingly become a ‘new normal’ feature of European politics. During this decade, rolling crises generated a wave of public discontent that damaged the legitimacy of national governments and the European Union and heralded a renaissance of populism. The central message of populist parties, which helped them rise in popularity or enter parliament for the first time, is simple but very effective: democratic representation has been undermined by national and global elites. This has provoked a wealth of studies seeking to explain the rise or breakthrough of populist fringe parties, without adequate consideration of how crises transform, not only the demand side, but also the supply of populist arguments, which has received scarce attention. This thesis seeks to address this imbalance by synthesising insights from the crisis framing literature, which facilitates an understanding and operationalisation of populism as a style of discourse. To assess how far-right parties employ this discourse, and the implications of this for their electoral prospects, a comparative case-study design is employed, exploring the discourse of parties, the National Rally (NR) in France and Golden Dawn (GD) in Greece. Their ideologically similar profile but differential electoral performance, allows for a more nuanced analysis of their respective framing strategies. The thesis examines the discourse of the two parties MPs on month by month basis over a four year period, 2012-2015 for GD and 2012-2013 and 2016-2017 for NR, via the use of the NVivo software. Their respective discourses are quantified and broken down into four key areas associated with Foreign Policy, the Economy, the Political System and Society, analysing the content, frequency and salience of key crisis frames. Discourse analysis of excerpts adds a qualitative element to the analysis that showcases the substantial differences between the two case studies. The analysis demonstrates that references to ‘the people’ and anti-elitism were the centrepieces of each case study’s discourse with strong nativist and nationalist elements. The two parties were extremely similar in the diagnostic stage of their framing and the way which they attribute blame for the crises. However, their discursive strategies diverge regarding their proposed solutions to the crises. Golden Dawn remained a single issue party in terms of discourse, since it never presented a comprehensive plan for ending the crises. As a result, Golden Dawn’s discourse remained one-dimensional throughout its brief period of success, being centred solely on attributing blame and attacking its political opponents and the European Union. On the other hand, National Rally’s framing was more elaborate and ambitious both in terms of the variety of issues raised and, especially, the proposed solutions if advocated. This, it is argued, contributed to the evolution of RN into a mainstream competitor that is no longer dependent on a niche part of the electoral market, while the inability of GD to develop equally successful crisis frames offers a unique understanding as to why the party failed electorally and was unable to enter Parliament in the 2019 elections. The overall analysis produces a rich framework that maps out the key elements of populist crisis discourse by far-right parties, which has implications for electoral politics and for our understanding of populism, more broadly
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