Ritual Interdependencies and Posthuman Intimacy: Consumer Engagements with AI Companions

Relational artificial intelligence (AI) systems—such as AI companions, chatbots, and affective interfaces—are increasingly woven into everyday consumer life, yet their symbolic, emotional, and cultural significance remains poorly understood. This thesis investigates how intimacy is cultivated, maintained, and experienced in relationships between consumers and AI companions, situating these emerging practices within Consumer Culture Theory (CCT) and posthumanist perspectives. Drawing on a multi-method qualitative design combining observational netnography, longitudinal engagement with AI platforms, and abductive thematic analysis, the research examines how users construct meaningful bonds with non-sentient agents through ritualised practices.The findings reveal that intimacy with AI companions does not arise from technological sophistication alone but is generated through ritual interdependence—a dynamic system of interconnected symbolic acts that sustain emotional realism across time. Three relational mechanisms underpin this process: mutualistic co-habitation, attunement, and metamorphic bonding. These mechanisms illuminate how users actively curate, maintain, and protect the illusion of relational depth, even as they remain aware of the AI’s ontological limits.The thesis makes three contributions. First, it reconfigures ritual theory for a digital, posthuman era by introducing the concept of ritual interdependence, showing that rituals in AI companionship are recursive, distributed, and co-performed across human–technology assemblages. Second, it advances understandings of posthuman intimacy by demonstrating how emotional connection can emerge without sentience, grounded instead in symbolic labour, algorithmic care, and affective infrastructures that script the conditions of attachment. Third, it extends consumer identity theory by conceptualising relational selfhood as it forms through sustained engagement with AI companions, where identity is negotiated via emotional feedback loops, performative presence, and the continuity offered by AI memory systems.Overall, this thesis provides a culturally grounded account of how consumers create emotionally meaningful relationships with AI companions, offering new theoretical pathways for understanding intimacy, identity, and ritual in an increasingly algorithmic consumer landscape

OSTRICH2: Solver for Complex String Constraints

We present OSTRICH2, the latest evolution of the SMT solver OSTRICH for string constraints. OSTRICH2 supports a wide range of complex functions on strings and provides completeness guarantees for a substantial fragment of string constraints, including the straight-line fragment and the chain-free fragment. OSTRICH2 provides full support for the SMT-LIB theory of Unicode strings, extending the standard with several unique features not found in other solvers: among others, parsing of ECMAScript regular expressions (including look‐around assertions and capture groups) and handling of user‐defined string transducers. We empirically demonstrate that OSTRICH2 is competitive to other string solvers on SMT-COMP benchmarks

Short Mahler-measure-preserving multiples of multivariable polynomials

The $2$-variable polynomial $(y + 1)x^2 + (y^2 + y + 1)x + (y^2 + y)$ has length $7$; it is a factor of the length-$6$ polynomial $(y+1)x^3 + x^2 - y^3x - y^3 - y^2$ which shares the same Mahler measure. On the other hand, consider the $2$-variable length-$7$ polynomial $(1+x) + (1-x^2+x^4)y + (x^3+x^4)y^2$. Extensive computations by Boyd and Mossinghoff suggested strongly that this has no length-$6$ multiple with the same measure. But how can one prove this? In this paper we develop a method which attempts to find the shortest multiple of a polynomial in $\mathbb{Z}[z_1,\dots,z_m]$ such that the multiple has the same Mahler measure as the original polynomial. The method is heuristic: it might fail (although we have yet to find an example when it does fail), but when it succeeds it provides a proof of shortness. In particular we can remove any doubt concerning the Boyd-Mossinghoff example mentioned above, and we are able to find shortest-possible Mahler-measure-preserving multiples of all the known $2$-dimensional examples having measure below 1.37

Translating environmental DNA for monitoring nature: species, ecosystems, policy and practice

The unprecedented biodiversity loss driven by human activity is pushing ecosystems toward collapse, threatening global economies, human health, and essential natural systems that sustain life on Earth. Restoring nature requires decisions grounded in science and evidence, gained through monitoring practices. Monitoring ecosystems is essential for guiding environmental management, but traditional biomonitoring often falls short due to time-consuming, labour-intensive methods reliant on bio-indicators and limited by an underpinning of ecosystem function and services. Environmental DNA (eDNA) is revolutionising our ability to efficiently assess biodiversity, from a single species to whole communities across the Tree-of-Life. While eDNA research is advancing rapidly, its uptake in applied sectors is lagging, where it could significantly enhance the scale, speed and sensitivity of biomonitoring. This thesis explores the gap between research and application through stakeholder engagement, develops practical guidance, and conducts primary research on policy-relevant monitoring targets, including invasive species and pathogens. Stakeholder interviews across policy, industry and academia highlight the need for improved communication tools, robust validation and standardisation of methods. These views were considered during the development of guidance for DNA monitoring with citizen science. These insights also shaped the development of a quantitative PCR (qPCR) assay for detecting the invasive Chinese mitten crab (Eriocheir sinensis), which demonstrates rigorous experimental validation using a standardised scale. Enhanced ecological assessments should integrate the suite of eDNA tools, from species to whole communities, as the efficiency of eDNA pipelines enables sampling across the continuum of eDNA to host-tissue, as explored by literature review. The molecular detection of the parasite Bonamia ostreae in native and invasive oysters will aid the Solent Oyster Restoration Project by furthering the understanding of disease spread. In summary, this thesis provides a framework for integrating enhanced eDNA-based ecological assessments into policy and practice, providing tools to inform environmental management and nature restoration