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Track matching using machine learning techniques in the ALICE Muon Forward Tracker
(2026) Barday, Salmaan; Horowitz, William; Buthelezi, Edith; Fortsch, Siegfried
Matching muon-arm tracks, reconstructed from the Muon Chambers (MCH) and Muon Identifier (MID), to Muon Forward Tracker (MFT) tracks is required to reconstruct global forward moun tracks in ALICE Run 3(2022- 2026). When the correct association is made, the MFT measurements close to the interaction point can be combined with the muon-arm track, yielding substantially improved pointing to the primary vertex. This is essential for separating prompt muons from displaced heavy-flavour decays, i.e. decays of particles containing charm or beauty quarks. For each muon-arm track, one selects the most compatible MFT candidate from a set of candidates, or rejects the match. The MFT reconstructs tracks very close to the interaction point, in a region of high track multiplicity. The muon-arm track, by contrast, is reconstructed further from the interaction point, only after the particle has traversed the hadron absorber. This transport distorts the trajectory through multiple scattering and energy loss. As a result, several MFT candidates can appear compatible with the same muon-arm track, and this ambiguity increases strongly in Pb–Pb collisions compared with pp. This thesis investigates supervised machine learning approaches to improve the MUON–MFT association decision while leaving other reconstruction steps unchanged. Training and validation use Run 3-style anchored Monte Carlo samples, which are simulated samples matched to realistic detector conditions and stored in the ALICE Analysis Object Data format (AO2D). These samples provide truth labels for candidate associations. Performance is evaluated with metrics designed for the best-candidate-or-no-match decision and studied in bins of transverse momentum to isolate the most difficult matching regions. In addition to track parameters from the AO2Ds, the models use engineered features that explicitly encode MUON–MFT compatibility. The study shows that retaining multiple candidate matches per muon-arm track is crucial for learning-based matching. Moving from a single saved candidate to five saved candidates substantially improves separability. For the stacked classifier, which combines the outputs of several base models, the ROC AUC increases from 0.916 to 0.968, corresponding to a 5.7% relative gain. In the multi-candidate setting, learning-based methods provide their most meaningful improvements at low pT. Across both proton–proton and Pb–Pb environments, the best-performing stacked configuration provides a robust balance between selecting correct pairings and maintaining matching efficiency in the most difficult kinematic region. Overall, the results demonstrate that supervised learning combined with multi-candidate information and physically motivated compatibility features can improve MUON–MFT association beyond the standard x2 baseline in both pp and Pb–Pb collisions. The largest impact is concentrated in the kinematic region where matching is intrinsically most challenging.
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Open Access
"Beyond the clash of civilizations" (Todorov)? The representation of the "sociorevolutionary" Islamist terrorism in contemporary Francophone literature (Philippe Lançon, Julien Suaudeau, Ousmane Diarra, and Bréhima Touré)
(2026) Bamupale, Kayembe Augustin; Arnold, Markus
Dans son essai La peur des barbares : Au-delà du choc des civilisations (2008), Tzvetan Todorov développe une théorie humaniste subdivisée en deux parties. « La peur des barbares », d'une part, identifie et dénonce le ressentiment que certains humains ont envers des populations issues des cultures différentes. L'idée de l'« au-delà du choc des civilisations » constitue, d'autre part, un appel à l'humanisme et à l'émancipation d'une grille de lecture identitaire réductrice pour lire les rapports culturels et géopolitiques globaux contemporains. En effet, Todorov conteste l'idée identitaire du « choc des civilisations » qui, selon Samuel Huntington, n'envisage la guerre qu'entre les populations issues des différentes aires culturelles. Dans le « monde nouveau » qui se dessine pour le politologue américain, « les conflits les plus étendues, les plus importants et les plus dangereux » dépasseront les clivages sociaux et économiques et auront lieu « entre peuples appartenant à différentes entités culturelles » (1997 : 20). La présente recherche s'appuiera sur ces deux pôles chez Todorov afin de comparer la représentation du terrorisme islamiste, dans sa forme « sociorévolutionnaire », dans quatre textes littéraires francophones contemporains, à savoir Dawa (2014) de Julien Suaudeau, Le lambeau (2018) de Philippe Lançon, La route des clameurs (2014) d'Ousmane Diarra et La guerre des influences (2019) de Bréhima Touré. Nous examinerons notamment comment ce corpus français-malien représente et investit la théorie huntingtonienne, qui est autant un reflet du terrorisme islamiste qu'il est susceptible de nourrir celui-ci. Mais nous nous intéresserons aussi à la question de savoir dans quelle mesure s'observent dans ces textes le postulat de l'« au-delà » civilisationnel selon Todorov ; une perspective qui complexifie et met à mal la lecture huntingtonienne ainsi qu'une lecture simpliste du terrorisme. En problématisant ces questions à travers ces quatre textes littéraires contemporains, cette recherche suggère que la perception du terrorisme islamiste doit évoluer d'une seule conception identitaire (soit civilisationnelle, culturaliste et religieuse) vers un cadre de lecture plus nuancé et complexe (soit historique et socio-politique). Cette ouverture des perspectives saura contribuer à une vision plus juste – plus émancipatrice et possiblement plus humaniste – quant à la représentation des violences historiques et contemporaines. Par ailleurs, le terrorisme islamo-politique mis en scène et analysé s'inscrit dans un prisme dit sociorévolutionnaire, dans la mesure où les personnages lient leurs motivations et actes djihadistes aux faits socio-politiques et (macro)économiques, y compris les défaillances étatiques, l'aire d'influence de la culture musulmane et les stratégies d'autodéfense. L'objectif principal de cette recherche est donc de montrer que l'engagement littéraire de Lançon, Suaudeau, Diarra et Touré repose également dans leur prise en compte critique de cette dimension sociorévolutionnaire afin de complexifier la représentation du terrorisme au-delà des visions idéologiques courantes.
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Open Access
Investigating how maternal HIV-1 infection and use of antiretroviral therapy impacts preterm birth using an in vitro model system
(2026) Andrews, Cameron; Woodman, Zenda
Preterm birth (PTB) remains a leading cause of neonatal morbidity and mortality, yet the mechanisms linking diverse maternal factors to premature labour are poorly understood. Women living with HIV, as well as those receiving antiretroviral therapy, have an elevated risk of preterm birth, but the underlying pathways remain unclear. This study investigated the effects of HIV pseudovirions (HIV-PSV), antiretroviral drugs, and immune cell interactions on human myometrial contractility using an in vitro model. HIV-PSV Env induced significant myometrial contraction, while ARVs had no effect. Viral entry assays confirmed that contraction occurs independently of productive infection. HIV-PSV exposure reduced ERK1/2 phosphorylation but triggered secretion of IL-1β, IL-6, IL-8, and MCP-1, with IL-1β and IL-6 directly promoting contraction. These findings support a model in which Env-dependent signalling activates myometrial cells and drives autocrine, cytokine-mediated contraction. This mechanism provides a biologically plausible explanation for PTB risk in women living with HIV and identifies potential targets for therapeutic intervention to mitigate HIV-associated preterm labour.
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Open Access
Family structure, inequality and child health in South Africa
(2026) Adika, Gameli; Muchapondwa, Edwin; Burns, Justine
This thesis examines the relationship between family structure, socioeconomic inequality, and childhood chronic illness in South Africa, using data from the National Income Dynamics Study (NIDS). It comprises three empirical chapters that collectively examine how access to healthcare, early-life nutrition, and household structure and multi-generational living arrangements shape chronic illness risks among children in South Africa. The first empirical chapter examines socioeconomic inequality in childhood chronic illness using data from 2012 and 2017 waves of NIDS. We find that reported chronic illness is concentrated among wealthier children; a pattern driven less by true differences in morbidity and more by unequal access to healthcare. Using concentration indices and decomposition methods, we quantify the contribution of socioeconomic factors to these disparities and examine changes over time. We further exploit geographic variation in exposure to the National Health Insurance (NHI) Phase 1 pilot to estimate its impact on reported chronic illness using a difference-in-differences design. The findings suggest that changes in inequality in relation to race, income, and access to sanitation contributed to the narrowing of pro-rich disparities in reported childhood chronic illness between 2012 and 2017. We also find that NHI pilot districts experienced a 40% increase in reported chronic illness, relative to non-NHI pilot districts. The findings highlight the importance of equitable access to healthcare in revealing and addressing hidden child health burdens. The second chapter examines the medium-term health effects of early-life undernutrition using data from the last 3 waves of NIDS. Drawing on the Developmental Origins of Health and Disease (DOHaD) and life-course frameworks, we estimate the impact of early nutritional status on reported childhood chronic illness using standard probit models. To account for temporal ordering, we model child health as a function of height-for-age z-scores, a proxy for nutritional status, in prior years. To strengthen identification, we correct for survival bias by inverse probability weighting and perform robustness checks using binary stunting indicators, measures of cumulative risk exposure, and an instrumental variables strategy. We find that more recent and severe stunting increases the likelihood of reported chronic illness among children. The findings underscore the long-term health costs of early-life nutritional deprivation and the urgent need for sustained investments in child nutrition to reduce chronic disease risk. The third empirical chapter uses panel data from the National Income Dynamics Study (NIDS) to examine how multigenerational living arrangements shape child health in South Africa, focusing on the roles of coresident grandmothers and remittances from non-resident parents. In the canonical household structure model, children in single-parent or non-parental households exhibit worse health outcomes than those in two-parent households. However, once the model is augmented to reflect South Africa's extended family structures, these differences disappear. Children in one-parent or no-parent households with a co-resident grandmother show no significant health disadvantage relative to those in two-parent households. Coresident, but pension-ineligible grandmothers improve child health primarily through caregiving time, while transitioning and eligible grandmothers do so through both time and income. Subgroup analyses show that the time contributions of pension ineligible grandmothers are particularly important in urban households, where both parents are present but likely engaged in full-time work and among younger children. The results are robust to potential diagnostic or reporting bias, adjusted using inverse probability weights (IPWs). The findings underscore the complementary roles of intergenerational care and financial transfers in promoting child health. Together, the chapters in this thesis contribute to the literature on health inequality, household economics, and child development and demonstrates that child health is shaped not only by nutritional and biological factors, but also by household structure, financial transfers, and access to care.
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Open Access
It's a kind of magic: Exploring the manipulation of magic and philosophy in Apuleius' Apologia
(2026) Chernotsky, Kaylie; Shelton, Matthew
My thesis examines how Apuleius manipulates the concepts of magic and philosophy in his self-defence speech, the Apologia. Through careful analysis of the text, I show that Apuleius characterises magic and its practitioners in two distinct ways: according to the common or vulgar view, and according to the intellectual or Platonic view. Although the two conceptions appear to be similar and share the name ‘magic' (magia), they are different, crucially in terms of piety: vulgar magic coerces the gods, while intellectual magic worships the gods. The crowd's narrow understanding of magic leads to the common error that confuses magic and philosophy and leads to the accusation that philosophers practise magic as it is commonly understood. As part of his argument, Apuleius aims to teach the audience about the intellectual view to correct this error. I show that Apuleius identities three groups in his audience: the intellectuals (himself and Maximus), the ignorant (the prosecution), and the uneducated crowd. Apuleius is careful not to equivocate between the crowd and the accusers. I show that Apuleius brings the audience into his rhetorical frame, to correct a wide misunderstanding of philosophy, which he argues has led to this accusation against him. I first examine Apuleius' outline of the different interpretations of magic (Chapter One) and then show how he uses this double conception of magic in his defence through three case studies (Chapters Two, Three, and Four).