VictorJuiz/thesis huggingface dataset:
On connections between dark matter and the baryon asymmetry
Keywords: Baryogenesis
Baryon Asymmetry
Dark Matter
Particle Theory

This thesis is dedicated to the study of a prominent class of dark matter (DM) models, in which the DM relic density is linked to the baryon asymmetry, often referred to as Asymmetric Dark Matter (ADM) theories. In ADM the relic density is set by a particle-antiparticle asymmetry, in direct analogue to the baryons. This is partly motivated by the observed proximity of the baryon and DM relic densities Ω_{DM} ≈ 5 Ω_{B}, as this can be explained if the DM and baryon asymmetries are linked. A general requisite of models of ADM is that the vast majority of the symmetric component of the DM number density, the DM-antiDM pairs, must be removed for the asymmetry to set the DM relic density and thus to explain the coincidence of Ω_{DM} and Ω_{B}. However we shall argue that demanding the efficient annihilation of the symmetric component leads to a tension with experimental constraints in a large class of models.
In order to satisfy the limits coming from direct detection and colliders searches, it is almost certainly required that the DM be part of a richer hidden sector of interacting states. Subsequently, examples of such extended hidden sectors are constructed and studied, in particular we highlight that the presence of light pseudoscalars can greatly aid in alleviating the experimental bounds and are well motivated from a theoretical stance. Finally, we highlight that self-conjugate DM can be generated from hidden sector particle asymmetries, which can lead to distinct phenomenology. Further, this variant on the ADM scenario can circumvent some of the leading constraints.
What should child poverty policy look like? Disjunctures between what young people, policymakers and academics think
Keywords: Policy
Participation
Poverty
Youth

This research uses a novel policy writing method to explore young people’s subjective understandings of the problems of poverty. Working with five groups of young people, aged 11 – 21, from some of the most financially deprived areas of England, it sought to draw out and explore their “policy imaginary”, or the way they viewed the problems of poverty through a lens of ideal policy responses.
It unpacks these young people’s policy imaginaries, and the life-narratives they discussed alongside these imaginaries, within a discourse of individualisation. Across four articles, it demonstrates and explores the complexities and ambiguities of these young people’s thinkings. This thesis begins by suggesting that many of the problems of poverty they identify as important to their lives are structural, and that they understanding the role of collective and political agency, rather than their own individual agency, in ending poverty. It then more specifically explores their understandings of their neighbourhoods and houses, which suggests that individualised factors often identified in other research, such as social contagion and epidemic neighbourhood effects, are not what they identify as most important in their local areas. It concludes by identifying a policy gap emerging along similar theoretical lines. Here, this research suggests that much of the policy directed towards these young people focuses on individualised problems, and their individual agency as a route of out poverty, but that this sort of policy response is not what these young people felt was needed.
However, this is not to suggest that these young people downplayed or dismissed their own agency in charting their life-pathways. Indeed, as much previous literature has found, these young people spoke fluently about the agency and opportunities they have in their lives, often seeming ‘hyper-agentic’. However, this thesis suggests that exploring these young people’s policy imaginary appears to create a medium through which they can talk both about their agency and the constraints and limitations low-incomes generate. It allowed them to bridge their highly agentic biographies to their socially structured histories, as they saw them.
Coping with 'ethnic' conflict: an analysis of teacher responses in Kenya
Keywords: Ethnic conflict
education
teacher development
Kenya

During post-conflict reconstruction, various roles are bestowed on teachers to manage the effects of violence such as peace educator, conflict resolution expert, counsellor and so on. However, there are no empirical studies that examine what teachers actually do when faced with the challenges of post-conflict schooling. More importantly, most policies often neglect the fact that teachers are not necessarily neutral in conflict. Whilst being professionals, many are also political and social beings that come from the community they serve. Surely the tension between their personal beliefs and professional practice has some impact on how teachers deal with the effects of conflict. This research investigates how teachers, who maintain a reflexive relationship with their community, feel about transforming their role to manage the effects of ethnic conflict.
The case of Kenya offers a suitable context in which to research this particular phenomenon because of its continuous association with conflict, consequent corrosion in ethnic relations, and increasing ethnic segregation in education systems. Employing a case study strategy, data was collected using semi-structured interviews and document analysis. The sample size consisted of twenty head teachers and seventy teachers and counsellors from government secondary schools in Nakuru and Kericho.
Analysis of the data suggests that ethnic tensions have seeped into schools affecting not only peer relationships but also teacher-student interactions. These tensions and fears continue to impair teachers from actively participating in schools and assuming the role of managing the effects of the conflict. Aside from this, various other factors in their classroots realities shape the manner in which they deal with the effects of the conflict. Some of these factors include external support, professional capacity, their purpose and motivation as well as the school culture.
This research concludes that teachers require adequate support and guidance from their head teacher in order to conceptualise their role in relation to managing the effects of violence. While the focus of external institutions is on relaying concepts of ‘peace’ and ‘conflict resolution’ to the students, there is merit in taking a more gradual approach and equipping teachers with the necessary skills and knowledge to teach these concepts. Moreover, teachers too require space to confront their own biases and prejudices towards other groups in order to assume these new roles. Finally, the creation of support networks is essential during post-conflict reconstruction as it ensures that teachers and students are provided with the necessary guidance, knowledge, and assistance in the absence of support from the state.
Tracing syndrome-specific trajectories of cognitive development: the impact of attention profiles on precursors of literacy and numeracy.
Keywords: Williams syndrome
attention
longitudinal
numeracy
Down syndrome
literacy

The research presented in this thesis combined a number of aims. One was to investigate in detail the early typical development of individual cognitive domains including attention, literacy and numeracy, and consequently to investigate whether domain-general attentional abilities constrain the development of either literacy or numeracy skills in preschool to school-age children. A further aim was to test the development of the same cognitive processes in two groups of children with developmental disorders of known genetic origin; Down syndrome (DS) and Williams syndrome (WS). A combination of standardised tests, novel experimental paradigms, and questionnaire measures were employed in pursuit of these aims, and children were assessed both cross-sectionally and longitudinally one year later. In typically developing (TD) children, novel findings pointed to differential influences of cognitive constructs of sustained and selective attention on the one hand, and executive attention on the other, on reading and numeracy abilities longitudinally. In both of the atypically developing groups of children, novel and individual patterns of developmental relationships emerged in the domains of attention, literacy and numeracy. In addition, the investigation of cross-domain relationships between attentional abilities and literacy and numeracy skills evidenced typical patterns in DS children, but atypical patterns in WS children. These findings emphasize the importance of cross-syndrome, cross-domain, and fully developmental research to understand both typical and atypical profiles of cognitive development. Furthermore, teaching practice, early identification of difficulties, and interventions should consider the wider implications of potential constraints of broader cognitive domains, such as attention, on learning.
A palaeoenvironmental history of the southern Bekaa Valley and the Lebanon Mountains, Lebanon during the last glacial period (~ 112-35 ka BP)
Keywords: last glacial period
Lebanon
landscape processess
climate change
vegetation dynamics

The remnant montane forests of southern Lebanon provide habitat to a rich diversity of endemic, rare and threatened plant and animal species. Prior to the intensification of human activity during the mid-Holocene period these forests covered most of the Lebanon and Anti-Lebanon Mountain ranges. What is not known is how the dynamics of these forests changed in response to major shifts in climate. The aim of this DPhil thesis was to document changes in vegetation composition in southern Lebanon during the last glacial period (~112 to 35 ka BP). To achieve this aim, a palynological study was conducted on a sedimentary sequence recovered from Aammiq Wetland located in the Bekaa Valley, Lebanon. Fossil pollen was analysed to reconstruct variability in vegetation composition and abundance. Energy dispersive spectroscopy, magnetic susceptibility and loss-on-ignition were used to reconstruct the geomorphological and hydrological processes acting within the wetland and its watershed. Macro and microcharcoal were analysed to reconstruct local and regional fire histories respectively. A chronology was established for this sequence using a combination of radiocarbon and optically stimulated luminescence dating (OSL) techniques.
The results indicate significant variability in the composition and abundance of vegetation through the time interval ~ 112 to ~ 35 ka BP closely aligned in time to global and regional climatic events. Changes in the chemical and physical properties of the sediments indicate significant variability in landscape erosion processes and hydrological conditions in the watershed and within the wetland over the similar interval in time. Peaks in local and regional fire activity were concurrent with periods of precession minima and Dansgaard-Oeschger warming events and had a significant impact on the composition of vegetation within the Aammiq region. These findings provide the first account of environmental change in the southern Bekaa Valley and adjacent slopes of the Lebanon Mountains during the last glacial period.
Characterisation of the HIV-1 reservoir and the potential for viral eradication
Keywords: virology
HIV
T cell
latency
AIDS
reservoir
eradication

The HIV-1 reservoir is the major barrier to eradication and cure of HIV-1 infection. The aim of this thesis was to characterise the HIV-1 reservoir in PHI and to investigate two potential reservoir clearance strategies.
Sensitive Q-PCR assays that quantify HIV-1 DNA reservoir level were developed and applied to characterise the HIV-1 reservoir in acutely infected patients enrolled in the SPARTAC trial. HIV-1 DNA levels were found to be a useful biomarker for predicting clinical progression and the time of viral remission in patients, after HAART interruption. Since low HIV-1 DNA reservoir levels were clinically beneficial, potential therapies aimed at decreasing the reservoir burden were investigated.
Thermotherapy was employed as a possible method for increasing CTL killing ability of HIV-1-infected cells. This may increase the likelihood of virological control and functional cure. SPION uptake impacted negatively on the natural killing ability of CTL that expressed the high affinity 868-TCR. However, localised thermotherapeutic heat generation was insufficient to cause direct thermal ablation of bound target cells or to enhance the natural killing ability of CTL.
868-TCR transduced CTL were employed directly as a means to target the latent viral reservoir by the ‘kick and kill’ hypothesis. Latent HIV-1 was reactivated in a variety of latent cell line models, but inconclusively in a primary model. 868-TCR transduced CTL killing of latently infected cells was observed. However, reactivation of latent virus did not necessarily relate to increased antigenicity of latent cells, perhaps in part due to anti-latency drug-induced alterations in MHC class I expression.
Despite recent and sustained interest in HIV-1 cure strategies, the prospect still remains elusive. Only through the development of sensitive assays that measure the HIV-1 reservoir and their application to novel and innovative cure strategies will HIV-1 ever be functionally cured or eradicated in patients on a large scale.
The effects of childbearing on women's body mass index, and on the risk of diabetes mellitus, or ischaemic heart disease after the menopause
Keywords: ischaemic heart disease
breastfeeding
obesity
BMI
parity
women
diabetes mellitus

Background: Excess adiposity, diabetes mellitus, and ischaemic heart disease are common important causes of morbidity and premature mortality in postmenopausal women in the UK. A large amount of data exists on known risk factors for these conditions, and for risk factors men and women share there is little evidence to suggest sex-based differences. It has been suggested that factors unique to women (such as parity and breastfeeding) may also influence risk. The nature of the relationship between childbearing and these conditions remains to be clarified. In this thesis I explore the association between women’s childbearing histories and their adiposity, and risk of diabetes or ischaemic heart disease after the menopause, to provide evidence on the character, repeatability and public health relevance of the associations.
Aim: To explore the hypothesis that childbearing (specifically parity and breastfeeding) is associated with women’s body weight and risk of excess adiposity, and also with women’s risk of diabetes mellitus, and ischaemic heart disease after the menopause.
Methods: Data are analysed from a large population-based cohort of middle-aged UK women recruited in 1996 to 2001 (the Million Women Study) with complete childbearing information, and who had baseline anthropometry, and were followed for incident diabetes or ischaemic heart disease through repeat survey questionnaires, hospital admission records, and central registry databases.
Results: In a large ethnically homogeneous population of postmenopausal UK women increasing parity was associated with an increase in BMI, however this increase was offset in women who breastfed. The associations between parity, breastfeeding and BMI were of a similar order of magnitude to established risk factors known to be associated with BMI, for example smoking, and physical activity. The associations between childbearing and women’s risk of diabetes mellitus after the menopause appear to be largely due to the effects of childbearing on maternal BMI. There is only limited evidence to suggest a direct effect of childbearing on women’s risk of diabetes after the menopause. There is statistically significant evidence of an association between childbearing and women’s risk of ischaemic heart disease after the menopause. Parity was associated with a modest increase in risk whereas breastfeeding was associated with a small decrease in risk, however the effects were small in comparison to known important risk factors.
Conclusions In a large population of UK women childbearing was found to have a persistent influence on women’s mean BMI after the menopause, and through this postmenopausal risk of diabetes mellitus. Childbearing was also found to be mod-estly associated with women’s risk of ischaemic heart disease after the menopause.
Arrangements of convenience: violent non-state actor relationships and citizen security in the shared borderlands of Colombia, Ecuador and Venezuela
Keywords: Ecuador
Colombia
security
transnational organised crime
Venezuela
borderlands
drug trade
conflict
Violent non-state actors
civil war

Borderlands are critical security zones but remain poorly understood. In regions plagued by drug violence and conflict, violent groups compete for territorial control, cooperate in illegal cross-border activities, and substitute for the functions of the state in these areas. Despite undermining physical security, fuelling fear, and challenging the state’s sovereignty, the exact modi operandi of these groups are little known.
Against this backdrop, this thesis explores how different interactions among violent non-state actors (VNSAs) in the Colombian-Ecuadorian and Colombian-Venezuelan borderlands impact on citizen security. These border areas attract rebels, paramilitaries and criminal organisations alike: they constitute geo-strategic corridors for the global cocaine industry and are sites of supply and operation for the major actors involved in Colombia’s decades-long armed internal conflict.
Adopting an interdisciplinary approach, this thesis consolidates the literature on conflict, security and organised crime, borders and borderlands, and anthropological approaches to fear and violence. It integrates theories of cooperation among social actors with original empirical research. It is based on a comparative, multi-sited case-study design, using ethnographic methods complemented by quantitative data. The research involved over twelve months of fieldwork with 433 interviews and participant observation on both sides of the crisis-affected Colombia-Ecuador and Colombia-Venezuela borders, and in Bogotá, Caracas and Quito.
Developing a typology of VNSA interactions, I argue that these create not only physical violence but also less visible types of insecurity: when VNSAs fight each other, citizens are exposed to violence but follow the rules imposed by the opposing parties. Fragile alliances produce uncertainty among communities and erode the social fabric by fuelling interpersonal mistrust. Where VNSAs provide security and are socially recognised, "shadow citizen security" arises: security based on undemocratic means. I show that the geography of borderlands reinforces the distinct impacts of VNSA arrangements on citizen security yet renders them less visible.
The relationship between engagement and learning in school students’ interactions with technology-driven multimodal exhibits in museums
Keywords: hands-on technologies
multimodal analysis
museum learning
science learning
history learning
multi-sensory technologies

This thesis reports a qualitative study of the use of multimodal technologies in museums— specifically, it examines the relationship between visitor engagement and learning, focusing on the use of multimodal technologies during school trips.
The study was conducted in the Natural History Museum and the Churchill Museum, both in London, with participants from several secondary schools. These sites were chosen due to their concern for the added value of learning and public engagement, including their education-orientated investments in technology, museum activities, and architecture. In the course of data collection, visits were made to six schools and both museum sites; the participants included 117 students, 18 teachers, three museum educators, and eight museum curators and media designers.
The study used a combination of video data analysis, stimulated recall interviews, document analysis, and engaging students in talk and reflection about their visit both at the museum and afterwards. The qualitative approach and multimodal analysis identify how the students’ social interactions help them construct learning through decontextualised bodily movements, which trigger contextualised discussion.
The study demonstrates how multimodal analysis can be used in research to capture a wide scope of information, while maintaining a micro-level of analysis and understanding—here, capturing the detail of students’ interactions and perceptions. The findings suggest that the learning experience in museums is produced through multiple layers of interaction and through the exchange of physical and psychological behaviour among people, resources, and space. Here, the multimodal technologies with which the students engaged essentially acted as initial platforms for sensory stimuli and social interaction, supporting their peer communication and motivating them to further explore both the given topic and their own understanding of their learning methods. It was the students’ further conversation, observation, and participation, however, that created a more meaningful and entertaining learning experience in the museums.
Higher order QCD corrections to diboson production at hadron colliders
Keywords: collider phenomenology
Hadronic colliders
QCD
NLO computations

Hadronic collider experiments have played a major role in particle physics phenomenology over the last few decades. Data recorded at the Tevatron at Fermilab is still of interest, and its successor, the Large Hadron Collider (LHC) at CERN, has recently announced the discovery of a particle consistent with the Standard Model Higgs boson. Hadronic colliders look set to guide the field for the next fifteen years or more, with the discovery of more particles anticipated.
The discovery and detailed study of new particles relies crucially on the availability of high-precision theoretical predictions for both the signal and background processes. This requires observables to be calculated to next-to-leading order (NLO) in perturbative quantum chromodynamics (QCD). Many hadroproduction processes of interest contain multiple particles in the final state. Until recently, this caused a bottleneck in NLO QCD calculations, due to the difficulty in calculating one-loop corrections to processes involving three or more final state particles. Spectacular developments in on-shell methods over the last six years have made these calculations feasible, allowing highly accurate predictions for final state observables at the Tevatron and LHC.
A particular realisation of on-shell methods, generalised unitarity, is used to compute the NLO QCD cross-sections and distributions for two processes: the hadroproduction of W+ W-jj, and the hadroproduction of W+ W-jj. The NLO corrections to both processes serve to reduce the scale dependence of the results significantly, while having a moderate effect on the central scale choice cross-sections, and leaving the shapes of the kinematic distributions mostly unchanged. Additionally, the gluon fusion contribution to the next-to-next-to-leading order (NNLO) QCD corrections to W+ W-j productions are studied. These contributions are found to be highly depen- dent on the kinematic cuts used. For cuts used in Higgs searches, the gluon fusion effect can be as large as the NLO scale uncertainty, and should not be neglected. All of the higher-order QCD corrections increase the accuracy and reliability of the theoretical predictions at hadronic colliders.