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Linear Diophantine equations and conjugator length in 2-step nilpotent groups
Get PDFWe establish upper bounds on the lengths of minimal conjugators in 2-step nilpotent groups. These bounds exploit the existence of small integral solutions to systems of linear Diophantine equations. We prove that in some cases these bounds are sharp. This enables us to construct a family of finitely generated 2-step nilpotent groups (Gm)m∈N such that the conjugator length function of Gm grows like a polynomial of degree m + 1
On the memory of the soul: the spiritualist metaphysic of Saint Augustine and Henri Bergson
No full textThis doctoral dissertation, On the Memory of the Soul: The Spiritualist Metaphysic of Saint Augustine and Henri Bergson, systematically presents the philosophical argument for the immateriality of the soul based on the phenomenon of recollection. It engages in a novel conceptual reconstruction of this argument by uniting the historically disparate philosophies of Saint Augustine (354–430) and Henri Bergson (1859– 1941). This dissertation not only provides an original comparative study of these monolithic thinkers, but it also rehabilitates and reframes their ideas by placing them in the context of both historical and contemporary philosophical discourse surrounding mind–body dualism and reductive materialism. With Bergson and Augustine, we advance a novel conception of the relationship between memory, time, and the human mind which serves to challenge the modern belief that the idea of the soul has no place in contemporary philosophy.This dissertation is divided into two parts. Part I, “Psychology” (Chapters I and II) consists in an analysis of memory in its diverse forms and a critical assessment of its traditional philosophical explanations. Part II, “Metaphysics” (Chapters III and IV), follows the steady approach from this alternative philosophy of memory to its wider implications for theories of self, mind, and soul. In Chapter I, “Image and Act”, we begin with an analysis of the psychology of memory and its ordinary operations. In Chapter II, “Brain and Mind”, we situate this model within the context of contemporary memory theory and question the limitations of the current “brain–storage” and “computer–brain” paradigms. In Chapter III, “Time and Duration”, we illustrate how memory expresses the peculiar relationship between the human being and time, expressed by Bergson in his concept of duration (la durée) and by Augustine in his concept of the distentio animi. In Chapter IV, “Memory and Soul”, we explore the meaning of soul, mind, and person in light of the previous analysis of recollection. Finally, in the Conclusion, we summarise the synthetic vision of the Augustinian–Bergsonian metaphysic of time, life, and memory
Conditional Cash Transfers, Schooling Decisions, and Labor-Market Conditions
Get PDFDoes the effectiveness of an education policy depend on the job opportunities in the local labor market? This paper provides a theoretical and empirical investigation of how schooling decisions respond to conditional cash transfer programs, across areas with different exposure to export manufacturing. Results show that Mexico’s PROGRESA program, documented to have increased educational attainment, was less effective in areas with more export-oriented manufacturing jobs. A theoretical model, combined with empirical evidence, suggests this is because these jobs generate more convex opportunity costs of schooling. Consistent with this, the heterogeneity documented is strongest among those old enough to be working in factory jobs. In addition, this heterogeneity is primarily driven by jobs that directly influence schooling opportunity costs: low-wage jobs and jobs for school-aged workers
Performance of active and passive ambulatory assessment measures and mood monitoring in bipolar disorder: a systematic review
Get PDFBackground: Ambulatory assessment uses digital technology to capture real-time data on mood, mental state and behaviour. It has the potential to enhance traditional clinical outcome measures, but the practical application of these tools fundamentally depends on their performance. Aims: This systematic review aimed to assess the performance of active and passive ambulatory assessment and mood monitoring outcome measures in non-randomised and randomised studies in bipolar disorder over 3 months or longer. We aimed to evaluate their performance against established clinical measures and through inter-ambulatory assessment comparisons. Methods: Systematic review (PROSPERO: CRD42023396473) of performance of mood monitoring and ambulatory assessment protocols in RCTs and non-randomised studies in bipolar disorder. Identified studies were assessed for risk of bias. Due to the very high heterogeneity in included studies and performance metrics we were not able to aggregate the data via meta-analysis. Results: The review included 42 studies with a combined sample of 7,813 participants. We included 28 distinct ambulatory assessment protocols which reported 487 different smartphone-based performance metrics. The considerable variability and inconsistency across these metrics limited our ability to make definitive comparisons of performance. Overall, some active ambulatory assessment approaches showed good performance when compared with established clinical measures. There was a paucity of data examining the performance of passive ambulatory assessment measures. Most studies were rated as having low to moderate risk of bias. Conclusions: While ambulatory assessment holds significant promise, current evidence fails to establish the validity and reliability of passive ambulatory assessment to measure mood. The substantial methodological variation—particularly in how performance metrics are defined and reported—limits meaningful comparison and replication. Greater consistency in ambulatory assessment design and reporting standards is essential to support reliable evaluation and broader adoption of these behavioural assessment tools
Homeostasis after injury: how intertwined inference and control underpin post-injury pain and behaviour
Get PDFInjuries are an unfortunate but inevitable fact of life, leading to an evolutionary mandate for powerful homeostatic processes of recovery and recuperation. The physiological responses of the body and the immune system must be coordinated with behaviour to allow protected time for this to happen, and to prevent further damage to the affected bodily parts. Reacting appropriately requires an internal control system that represents the nature and state of the injury and specifies and withholds actions accordingly. We bring the formal uncertainties embodied in this system into the framework of a partially observable Markov decision process. We discuss nociceptive phenomena in light of this analysis, noting particularly the counter-intuitive behaviours associated with injury investigation, and the propensity for transitions from normative, tonic, to pathological, chronic pain states. Importantly, these simulation results provide a quantitative account and enable us to sketch a much needed roadmap for future theoretical and experimental studies on injury, tonic pain, and the transition to chronic pain
PSyDUCK: hiding information in the denoising process of latent diffusion models
Get PDFRecent advances demonstrate that information can be covertly embedded in the outputs of stochastic generative AI models, raising both opportunities for secure communication and risks of misuse. Existing latent diffusion steganography methods typically hide data in the entropy of the initial latent state, inherently limiting embedding capacity. In this work, we instead investigate information hiding within the entropy of the diffusion denoising process itself. We introduce PSyDUCK, a simple but efficient framework that leverages controlled divergence and local mixing during denoising to enable high-capacity message embedding while preserving visual fidelity. Our empirical evaluation shows PSyDUCK can hide substantial information in both image and video diffusion models. While our formal analysis indicates that the security guarantees of denoising-based embedding are limited, the existence of this channel nonetheless requires that steganalysis methods account for entropy throughout the entire denoising process - not just in the initial latent state
The impact of low-coverage whole-genome sequencing on advancing genetic epidemiology studies in global populations
Get PDFGenetic epidemiology connects genomics with population health, offering insights into disease susceptibility, progression, and treatment outcomes. Understanding how genetic variation shapes these traits reveals biological mechanisms and informs clinical interventions. Yet, most existing knowledge stems from European, American, and select Asian populations, leaving major gaps in underrepresented regions where infectious diseases are most common. Expanding genomic studies to these populations is essential for scientific equity and a fuller understanding of human biology. Low-coverage whole-genome sequencing (lcWGS) offers a cost-effective, unbiased alternative to genotyping arrays and deep sequencing. LcWGS with imputation enables accurate variant discovery without ascertainment bias, enhancing sensitivity to population-specific and complex variants and making it especially valuable for large-scale global studies.This thesis explores the potential of lcWGS in genetic epidemiology through applications in the context of global populations with two cohorts from Africa and Asia. Using samples from The Gambia, I benchmarked lcWGS performance in detecting genome-wide variants, HLA alleles, and structural variants, demonstrating its strong potential for comprehensive variant discovery. In addition, I developed strategies to further improve imputation accuracy by refining computational workflows and enhancing population representation. Then, I applied lcWGS in a genome-wide association study of Hepatitis C Virus infection in a Vietnamese cohort, identifying a regulatory variant of OSBPL2 that likely influences viral replication. Together, these findings demonstrate lcWGS as a scalable, accurate, and inclusive approach for global genetic studies
A political disconnect? Evidence from voting on trade agreements
Get PDFWe study votes of Members of the European Parliament (MEPs) on the approval of free trade agreements (FTAs). Against widespread Eurosceptic arguments, we find that MEPs are responsive to the interests of their electorate and their re-election chances increase with the extent to which their votes on trade agreements are aligned with their constituents’ interests. By contrast, US legislators’ votes on FTAs are disconnected from their electorate’s interests and do not impact their re-election chances. Our results suggest that legislators’ accountability on a policy issue may depend on its salience relative to other policies in the legislators’ sphere of competence
A systematic review and meta‐synthesis of qualitative studies of alopecia: Managing identity and appearance changes
Get PDFPurpose: Alopecia is a medical dermatology condition resulting in multiple psychosocial negative consequences in identity and appearence. Despite numerous qualitative studies examining the experience of people with alopecia, a comprehensive synthesis is lacking. This can obscure progress in research and minimize the impact of psychosocial support people with alopecia can receive. This systematic meta‐synthesis aimed to critically integrate the existing literature to enhance psychological understanding of how people with alopecia manage issues about identity and appearance changes, and provide some evidence‐based recommendations for clinicians working in the area of psychodermatology. Methods: A systematic search of six databases: APA PsycInfo (OVID), Medline (OVID), Embase (OVID), CINAHL (EBSCO) and Scopus identified 22 eligible studies on the lived experience of alopecia among adults, adolescents and parents. The Critical Appraisal Skills Programme Qualitative Checklist was used to appraise the quality of the studies. Extracted data underwent inductive thematic analysis. Results: The synthesis, representing 990 people living with alopecia, identified five main themes, focusing on managing identity and appearance changes: (1) coming to terms with a changed identity; (2) the journey to acceptance; (3) complexities of concealing hair loss; (4) social influences in both facilitating and hindering adaptation; and (5) treatment experiences highlighting unmet needs. Findings reveal substantial variation in managing identity and appearance changes, with some individuals achieving acceptance swiftly while others struggle. Social reactions and personal interpretations significantly shape adjustment. Conclusions: Alopecia profoundly impacts identity, coping, and social interactions, often accompanied by dissatisfaction with health care and treatment options. The reactions of other people and interpretations of these experiences appear to play a key role in adjustment. The review underscores the need for personalized, non‐pharmacological interventions that address personal and social challenges. Greater co‐production in health care training and intervention development is necessary to improve support for individuals with appearance‐altering conditions