143174 research outputs found
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On independence and SCC-recursiveness in assumption-based argumentation
No full textWe introduce a notion of conditional independence in (flat) assumption-based argumentation (ABA), where independence between (sets of) assumptions amounts to the presence of information about one set of assumptions not impacting the acceptability of another. We study general properties, computational complexity, and the relation to independence in abstract argumentation. In light of the high computational complexity of deciding independence, we introduce sound methods for checking independence in polynomial time via two different routes: the first utilizes the strongly connected components (SCCs) of the instantiated abstract argumentation framework; the second exploits the structure of the ABA framework directly. Along the way, we introduce the notion of SCC-recursiveness for ABA
Running into the Lyme-light: a retrospective cross-sectional study of tick bites and Lyme disease prevalence, incidence, and prevention in hill runners, Scotland, UK
No full textBackground
Lyme disease (LD) incidence is increasing globally, driven by changes to habitat and human-vector interactions. Effective prevention relies on local and individual-level understanding of risk and ecosystem interactions. Despite frequent exposure to tick habitats, little is known about tick bites and LD risk among hill, trail, and mountain runners. This study aimed to evaluate the period prevalence of tick bites and incidence of LD in hill runners in Scotland, UK and examine preventive behaviours.
Methods
A cross-sectional retrospective survey of Scottish hill runners was conducted in June-July 2024. Hill runners aged 18+ resident in Scotland for the 12 months preceding the survey were eligible. Period prevalence was calculated as the proportion of hill runners with at least one self-reported tick bite in the 12 months preceding the survey. Treated suspected LD incidence was calculated for all study participants and those registered in competitive hill races. Multiple logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) of having a tick bite, for variables including age, sex, running hours per week, proportion of running that is hill running, other outdoor activity hours per week, frequency of insect repellent use, full leg and arm cover use, and full body tick checks.
Results
212 hill runners (56.1% male) completed the survey. Period prevalence of at least one tick bite was 82.5% (95%CI 76.76-87.40). Incidence of treated suspected LD for the 212 study participants was 4245.3 per 100,000 (95%CI 1941.21-8058.87), and the minimum estimate in 4668 registered competitive hill racers was 150.0 per 100,000 per year (95%CI 60.29-309.97). Most hill runners reported never/infrequently wearing full leg cover (67.9%), arm cover (58.0%), or using insect repellent (74.5%). Regularly/almost always conducting a tick check was associated with higher odds of at least one tick bite (OR 8.52, 95%CI 3.29-22.90, p<0.001), whereas regularly/almost always wearing full leg cover was associated with lower odds (OR 0.35, 95%CI 0.13-0.89, p=0.029), versus never/infrequently.
Conclusions
A high reported period prevalence of tick bites and incidence of treated suspected LD among surveyed hill runners in Scotland aligned with the low adherence to tick bite prevention behaviours in this population. Improving adherence with leg cover recommendations may lower the risk of tick bites. Raising awareness of tick bite risk and prevention may benefit hill runners internationally as the sport grows
Effect of interparticle friction on the one-dimensional compression behaviour of clay
No full textThis paper considers the effects of interparticle friction on the one-dimensional (1D) compression behaviour of clay via coarse-grained molecular dynamics (CGMD) simulations. In the CGMD simulations, individual clay particles are modelled as flat ellipsoids and particle interactions are described by the potential energy of interaction between a pair of particles as a function of their
separation distance and relative orientation. Most potential functions do not explicitly describe interparticle friction and so this study implemented a novel CGMD framework to simulate interparticle friction. The data generated confirmed the need to describe interparticle friction to reproduce physically realistic values for the coefficient of lateral earth pressure (0). Friction was also shown to
determine hysteresis in load-unload cycles. Despite the challenges associated with measuring 5 interparticle friction for clay, it is clear that this parameter is important, that it should be included in particle-scale simulations of clay, and that future research efforts should address uncertainty about how best to analytically/numerically describe friction and which friction model should be adopted
A modeling framework for fuel distribution systems in hydrogen-powered aircraft
No full textThe low-technological maturity, tightly coupled integration, and impact on aircraft-level feasibility of fuel systems on-board hydrogen-powered aircraft drives a need to both
explore the architectural design space and thoroughly characterise feasibility. To address these challenges, this work presents a Model for Exploring Hydrogen Fuel System Architectures (MEHFSA) that is both flexible to represent a wide range of system architectures and
able to capture interdisciplinary couplings and important physical phenomena to accurately characterise system feasibility. Integration of MEHFSA within an aircraft design environment demonstrates the ability to perform feasibility evaluations on two different fuel system architectures that evolve with time based on interdisciplinary interactions with changing operating conditions
Intervertebral disc distraction stiffness predicts endplate subsidence following transforaminal interbody cage expansion: an ex vivo study
No full textPurpose: Expandable cages have the potential to mitigate the currently high subsidence rates following transforaminal lumbar interbody fusion (TLIF), but are liable to over-distraction in situ. This may be due to the undefined patient-specific expansion threshold of the intervertebral disc (IVD) space. This study aimed to elucidate whether IVD properties affect the torque required to expand the cage within the IVD space, and determine the association between achieved torque, distraction stiffness, and subsidence severity.
Methods: Fifteen cadaveric L3-L4 and L4-L5 samples were prepared with the TLIF approach. Under 100N compression, the torque required to expand the cage per half-turn, alongside the changes to IVD and cage height, were recorded until maximum cage expansion. Subsidence
depth was measured after subsequent cyclic loading, and the surface area of removed IVD tissue was quantified post-test.
Results: Peak torque was inversely associated with preloaded IVD height (B: -0.34, p < 0.001) and the percentage of IVD removed (B: -0.04, p < 0.01). IVD distraction stiffness was associated with preloaded IVD height only (B: -0.19, p < 0.001). There was no association with IVD or facet degeneration. When subsidence depth was normalised to bone mineral density, a positive correlation was observed with peak torque and cage expansion stiffness (both p < 0.05).
Conclusion: The torque required to expand interbody cages in situ is relevant to subsidence risk, and depends on IVD geometry and the amount of residual tissue. Thus, short IVDs should be thoroughly prepared to alleviate excessive stiffness during cage expansion
Enhancing floc growth by oxidative and reductive modification of organic matter structure
No full textCoagulation is a critical process in drinking water treatment for removing contaminants, but its efficiency is challenged by complex natural organic matter (NOM) and emerging micropollutants. Conventional strategies (e.g., enhanced coagulation and novel coagulants) overlook the role of NOM characteristics in floc formation. Existing studies lack systematic evaluation of how chemical preconditioning (oxidation/reduction) modifies NOM functional groups and influences floc dynamics, particularly regarding molecular-scale mechanisms and water matrix effects. This study comparatively evaluates hypochlorite (NaClO), hydrogen peroxide (H₂O₂), and sodium borohydride (NaBH₄) pretreatments for NOM modification and their impacts on floc growth during coagulation. It was found that while NaClO (0.2–4 mg/L) reduced molecular weight and increased hydrophilicity, it consistently enhanced floc size (up to 44 %) by hydroxylating aromatic NOM. H₂O₂ exhibited a biphasic effect, and floc size improved at low doses (1 mg/L) but declined at high doses (>4 mg/L) due to excessive carboxyl group formation, inducing electrostatic repulsion. NaBH₄ (50–100 mg/L) promoted floc growth by reducing carbonyl to hydroxyl groups, though high doses (>100 mg/L) reduced efficacy due to borate interference. This work establishes molecular-level mechanisms for NOM-coagulant interactions, highlights the essential role of hydroxyl groups on floc formation, and provides a scientific basis for optimizing pretreatment-coagulation sequences tailored to specific water quality
Vinorelbine enhances the efficacy of oncolytic vaccinia virus in a preclinical model of ovarian high grade serous carcinoma
No full textVaccinia virus, known for its clinical safety, has a tropism for primary and metastatic tumors as well as ovarian tissue. Consequently, oncolytic approaches with recombinant vaccinia viruses have emerged as attractive agents against ovarian cancer. Unfortunately, oncolytic vaccinia monotherapies are yet to live up to their potential promise. Given this, there is a need to identify combination agents that improve the effectiveness of vaccinia in ovarian cancer treatment. We screened 9,000 compounds to identify drugs that enhance the ability of a recombinant vaccinia virus lacking VGF and F1 (ΔVF) to induce death of ID8 Trp53−/− murine ovarian cancer cells. We identified a class of tubulin polymerization inhibitors including vinorelbine. The combination of vinorelbine and vaccinia induces ID8 Trp53−/− cell death via apoptosis. In a syngeneic mouse model of high-grade serous ovarian carcinoma, ΔVF virus lacking the viral thymidine kinase (TK), armed with granulocyte-macrophage colony-stimulating factor (GM-CSF), and expressing NeonGreen (ΔVFTK-NG-GM-CSF) is tumor-specific. A combination of the ΔVFTK-NG-GM-CSF virus with vinorelbine prolongs mouse survival compared to the treatment of mice with either agent alone. Our study suggests that vinorelbine is a promising agent to combine with oncolytic vaccinia virus for the management of ovarian cancer
Automating operations and maintenance manual data extraction for retrofit applications: assessing GPT-4o’s performance and challenges
No full textOperations & Maintenance (O&M) manuals contain data that is essential to understand ahead of building retrofits. However, their unstructured format makes information retrieval time-consuming and error-prone. This study evaluates GPT-4o’s ability to extract information from O&M manuals, assessing accuracy in text extraction, categorization, and numerical data handling. Structured extraction steps and prompt strategies were developed based on industry needs. The extraction performance was compared to human-extracted data based on a dataset of 60 O&M manuals, using quantitative and qualitative evaluation. Results form the study show that text-based extraction is reliable, particularly for component names, types, and manufacturer details, where formatting differences had little impact on accuracy. However, challenges appeared in fields requiring categorization, numerical interpretation, and structured mapping. One issue was category misalignment, where GPT-4o could assign components to broad categories but had difficulty with domain-specific classifications that require specialized knowledge. This inconsistency suggests that rule-based constraints or further adjustments may be needed to improve standardization in retrofit applications. Another challenge was the model’s handling of numerical data. Mistakes occurred in quantity extraction, page numbering, and location references, where the model miscalculated totals, misread measurement units, or mismatched printed and digital page numbers. These errors suggest that GPT-4o lacks a way to process numerical information in context, meaning manual checks are still required for numerical fields. These findings highlight GPT-4o’s potential to automate O&M data extraction, reducing manual effort and speeding up the retrofit process
Mechanical unloading coupled with coronary reperfusion stimulates cardiomyocyte proliferation and prevents unloading-induced fibrosis after myocardial infarction
No full textPercutaneous left ventricular assist devices (LVADs) have become essential tools during coronary reperfusion in high-risk PCI. Significant reduction in infarct propagation is observed when mechanical unloading is coupled with reperfusion, but little is known of the effect this reduction in wall stress and extracellular matrix with LVADs has on the heart's regenerative capacity. This study investigates the effect coronary reperfusion coupled with mechanical unloading has on myocardial fibrosis, and the impact of these changes in extracellular matrix on the heart's regenerative potential. MI was induced by coronary artery ligation in Lewis rats. Hearts underwent permanent coronary ligation (AMI) or were reperfused after 90 min (AMI/R). In each group, hearts were either loaded (AMI-L or AMI/R-L) or unloaded (AMI-U or AMI/R-U). In the unloaded subgroup, the infarcted hearts were explanted after 90 min and transplanted into the abdomen of healthy recipients via heterotopic abdominal heart–lung transplantation. The recipient’s heart acted as control. Hearts were analysed on day 7. 30 hearts were studied. In the permanent ligation group, fibrosis increased in both the loaded and unloaded hearts with no significant rise in cardiomyocyte proliferation. After coronary reperfusion, no increase in fibrosis was observed with mechanical unloading but cardiomyocyte proliferation rose significantly (AMI/R-L vs AMI/R-U p = 0.0001). Cardiomyocyte proliferative rate in the loaded and unloaded hearts was 0.6% and 3.7%, respectively, after permanent ligation, and 0.5% and 10.4%, respectively, after coronary reperfusion. These data show that coronary reperfusion coupled with mechanical unloading reduces myocardial fibrosis and upregulates cardiomyocyte proliferation after myocardial infarction
Assessing the population genetic structure and demographic history of Anopheles gambiae and Anopheles arabiensis at island and mainland sites in Uganda: implications for testing novel malaria vector control approaches
No full textBackground
Despite substantial investments in malaria control, the disease remains a major burden in sub-Saharan Africa, particularly Uganda. Novel tools such as gene drive systems are being developed to suppress malaria vector populations, but their deployment requires detailed knowledge of mosquito population genetics.
Methods
The genetic structure, diversity, and demographic history of Anopheles gambiae and Anopheles arabiensis were assessed at six sites in Uganda: three islands in Lake Victoria and three mainland sites. A total of 2918 An, gambiae and 173 An. arabiensis were genotyped using targeted amplicon sequencing of 62 loci across coding and non-coding regions of the genome.
Results
Population structure analyses revealed clear separation between the two species but little differentiation within each species across sites. Pairwise FST values among An. gambiae populations were low (0.00054–0.028) but often statistically significant, with mainland populations showing higher connectivity and island populations exhibiting greater isolation. Anopheles arabiensis mainland populations showed no statistically significant differentiation, suggesting panmixia. Principal component analysis and Bayesian clustering similarly distinguished species-level structure but no obvious substructure within sites.
Mainland An. gambiae populations displayed higher nucleotide diversity than island populations, while An. arabiensis showed the lowest diversity overall. Tajima’s D values were negative across sites, consistent with recent population expansions. Effective population size estimates indicated small populations at the islands (146–249) compared to large mainland populations (4054–8190).
Discussion
These findings demonstrate strong genetic differentiation between An. gambiae and An. arabiensis, and subtle but meaningful structure between island and mainland An. gambiae populations. The reduced diversity and small effective population sizes at island sites suggest stronger genetic drift and limited gene flow, in contrast to the highly connected mainland populations.
Conclusion
This study highlights how geographic and ecological factors shape mosquito population structure and provides critical evidence for the design and monitoring of genetic-based vector control interventions, including the planning and evaluation of field trials