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Reconceptualising leprosy self-care as a social practice: a qualitative study in North Central Nigeria
No full textLeprosy self-care is essential for preventing disability and preserving dignity but remains challenging in resource-constrained settings like Nigeria. Traditional behavioural approaches often fail to address the broader social and material factors influencing self-care sustainability. This study employs Social Practice Theory (SPT) to reconceptualise leprosy self-care as a socially embedded practice, moving beyond individual-focused interventions. Conducted over four months in a leprosy-designated village in North Central Nigeria, the research utilised a qualitative methodology grounded in hermeneutic phenomenology. Data were collected through 20 in-depth interviews with individuals affected by leprosy, five key informant interviews, and 16 hours of non-participant observation. Thematic analysis, guided by SPT’s framework of competences, materials, and meanings, revealed that self-care is shaped by dynamic interactions among skills, resource availability, and cultural interpretations. Challenges included inadequate supplies, inconsistent healthcare support, and stigma, which often undermined engagement. Religious practices and daily routines, such as ablution, sometimes supported self-care, while competing activities like street begging posed barriers. The study distinguishes between replaceable and irreplaceable materials, highlighting their impact on practice sustainability. Family and peer involvement further influenced outcomes, either reinforcing or weakening self-care efforts. By framing self-care as a social practice, this research underscores the need for systemic, contextually sensitive interventions that integrate material provision, skill development, and stigma reduction. SPT offers a robust framework for designing multi-level strategies to enhance self-care for leprosy and other chronic conditions, promoting sustainable health outcomes in marginalised communities
The dependence of triggering mechanisms on radio AGN sub-types : the role of galaxy mergers
No full textPowerful, radio-loud active galactic nuclei (AGN) are associated with one of the most important forms of AGN feedback, and understanding how they are triggered is key to properly incorporating them into models of galaxy evolution. Here, we present the results of a deep Isaac Newton Telescope/Wide Field Camera imaging survey which, when combined with Gemini/Gemini Multi-Object Spectrograph South images, gives a 98 per cent complete sample of 112 3CR radio galaxies with redshifts z < 0.3, alongside a stellar mass matched control sample. Our results provide strong evidence for significant differences (∼3σ) between the triggering mechanisms of the different sub-types of powerful radio AGN. The high-excitation radio galaxies (HERGs) show a high rate of morphological disturbance (62 per cent) – an excess of ∼4σ compared with the control sample – consistent with them being predominantly triggered in galaxy mergers and interactions. In contrast, the low-excitation radio galaxies (LERGs) show a much lower rate of morphological disturbance (36 per cent), consistent with the control sample, and suggesting a different dominant triggering mechanism, such as the accretion of gas from the hot X-ray haloes of the host galaxies or galaxy clusters. We also demonstrate that, when considering the radio morphology, the FRII HERG sources preferentially reside in disturbed morphologies, a difference of ∼3σ to the FRII LERG objects. This suggests that the FRII LERG sources do not solely represent a ’switched-off’ phase in the HERG lifecycle of the same parent galaxy population as the FRII HERGs
Search for heavy neutral leptons in decays of W bosons produced in 13 TeV pp collisions using prompt signatures in the ATLAS detector
No full textThe existence of right-handed neutrinos with Majorana masses below the electroweak scale could help address the origins of neutrino masses, the matter–antimatter asymmetry, and dark matter. In this paper, leptonic decays of W bosons from 140 fb - 1 of 13 TeV proton–proton collisions at the LHC, reconstructed in the ATLAS experiment, are used to search for heavy neutral leptons produced through their mixing with muon or electron neutrinos in a scenario with lepton number violation. The search is conducted using prompt leptonic decay signatures. The considered final states require two same-charge leptons or three leptons, while vetoing three-lepton same-flavour topologies. No significant excess over the expected Standard Model backgrounds is found, leading to constraints on the heavy neutral lepton’s mixing with muon and electron neutrinos for heavy-neutral-lepton masses. The analysis excludes | U e | 2 values above 8 × 10 - 5 and | U μ | 2 values above 5.0 × 10 - 5 in the full mass range of 8–65 GeV. The strongest constraints are placed on heavy-neutral-lepton masses in the range 15–30 GeV of | U e | 2 < 1.1 × 10 - 5 and | U μ | 2 < 5 × 10 - 6
Dynamic Allocation of Mobile Servers in a Network
Get PDFMany operations research problems focus on optimizing network flows and routing in deterministic settings, yet real-world systems are inherently stochastic and dynamic. Allocating resources efficiently in such environments requires decision-making that responds to both spatial and temporal variations in demand. This thesis studies such problems in stochastic networks, where customer demand arrives randomly over time. Demand points generate jobs according to independent Poisson processes, and homogeneous servers travel across the network to provide service, with exponentially distributed service and switching times. Service and switching times are interruptible, allowing servers to adjust tasks in response to new changes. The objective is to minimize long-run average holding costs by balancing immediate responsiveness with long-term efficiency. The system is modeled as a Markov Decision Process, but the large state space renders exact optimization infeasible. To address this, the thesis develops scalable approximation methods that combine structural insights from index heuristics with computational approaches from approximate dynamic programming and reinforcement learning. The first part of the thesis focuses on single-server systems. Chapter 2 analyzes an infinite-state model and develops index-based policies with desirable structural properties. Chapter 3 considers a finite-state model and introduces reinforcement learning techniques to refine index heuristics through approximate policy improvement. The second part, introduced in Chapter 4, extends the analysis to multi-server systems, where additional challenges of coordination and workload balancing arise. In this setting, multiple servers may occupy the same node and provide service simultaneously. To address these, new heuristics are proposed, involving proportional assignment of demand points to servers to form server-specific local regions, allowing a modified version of the index-based heuristic from Chapter 2 to be applied. Numerical experiments across a variety of network configurations demonstrate that the proposed policies deliver strong performance while remaining computationally tractable
Crop genotypic richness enhances biomass production and phosphorus acquisition in maize‐mycorrhiza symbiosis
Get PDFSocietal Impact Statement: Our study tests how soil and plant biodiversity can enhance sustainability of crop production in Kenya. We tested whether mixtures of maize varieties performed better than monocultures and tested their response to arbuscular mycorrhizal fungi. Mycorrhizal responsiveness differed significantly by maize variety, and genetic mixtures outperformed monocultures. These findings demonstrate the benefits of using naturally‐occurring soil microorganisms in combination with genetic mixtures of crops to enhance food security. Summary: Plant genetic diversity is a key component of biodiversity but one that is often overlooked when considering the adoption of sustainable strategies to enhance crop production, such as inoculation with arbuscular mycorrhizal (AM) fungi. Here, we tested the hypothesis that the biomass of the most responsive maize genotypes to AM fungal inoculation when grown in genetic monoculture would be enhanced when grown in mixtures comprising a mix of genotypes (polyculture). In a first experiment, maize varieties were inoculated with Rhizophagus irregularis or Funneliformis mosseae or left uninoculated. We measured key growth parameters, AM fungal colonisation and phosphorus uptake and calculated mycorrhizal responsiveness. A second experiment evaluated the effect of crop genetic diversity on productivity by growing the four most responsive varieties as either monocultures or polyculture, with and without AM fungal inoculation. Mycorrhizal responsiveness differed significantly by maize variety, with some varieties demonstrating greater benefits from AM fungi. Polycultures outperformed monocultures in terms of AM fungal colonisation, biomass and phosphorus capture, which were driven by a combination of complementarity and facilitation effects resulting from biodiversity. Our findings demonstrate the critical role played by AM fungi in shaping crop genotype performance and the potential benefits of moving away from cropping systems that rely on genetic monocultures. The use of AM fungal inoculum in combination with targeted locally adapted crop genotype mixtures maximises plant nutrient efficiency and productivity and provides a sustainable approach to maize production in sub‐Saharan agroecological systems
Fact, Value, and Disorder
No full textPhilosophers of medicine have long sought to understand the distinction between the normal and the pathological, and have proposed a number of different accounts of “disorder.” Christopher Boorse has argued that disorder is fundamentally a factual concept, belonging to the biological sciences. Normativists disagree, and see disorder as a value-laden concept, connected to notions of “the good life.” All accounts of disorder developed to date run into difficulties, and there is a sense that the philosophical project that aims to describe our current concept of disorder has become bogged down. A number of authors have now given up trying to describe our current concept of disorder and have instead moved to revisionary projects of conceptual engineering. Eliminativists argue that we would do best to eliminate the concept of disorder, while more optimistic revisionists have proposals for new concept(s) of disorder that might better advance scientific or social progress
Smoothing of bivariate test score distributions - Model selection targeting test score equating
Get PDFObserved-score test equating is a vital part of every testing program, aiming to make test scores across test administrations comparable. Central to this process is the equating function, typically estimated by composing distribution functions of the scores to be equated. An integral part of this estimation is presmoothing, where statistical models are fit to observed score frequencies to mitigate sampling variability. This study evaluates the impact of commonly used model fit indices on bivariate presmoothing model-selection accuracy in both item response theory (IRT) and non-IRT settings. It also introduces a new model-selection criterion that directly targets the equating function in contrast to existing methods. The study focuses on the framework of non-equivalent groups with anchor test design, estimating bivariate score distributions based on real and simulated data. Results show that the choice of presmoothing model and model fit criterion influences the equated scores. In non-IRT contexts, a combination of the proposed model-selection criterion and the Bayesian information criterion exhibited superior performance, balancing bias, and variance of the equated scores. For IRT models, high selection accuracy and minimal equating error were achieved across all scenarios
