Queen's University Belfast

Poly-γ-glutamic acid (γ-PGA) is a valuable biopolymer with diverse industrial applications, produced naturally by several Bacillus species. The dairy environment is an under-explored niche for identifying efficient, food-grade γ-PGA producers. In this study, four legacy dairy-derived Bacillus licheniformis strains: DPC3803, DPC6338, DPC6339, and DPC6340, producing high γ-PGA titres were examined using whole genome sequencing (WGS) and comparative genomic analysis to evaluate their suitability for future industrial applications. The genomes ranged from 4.19 to 4.29 Mb with an average GC content of 45.8–46.2%. Pangenome analysis of the four strains, together with 51 publicly available B. licheniformis genomes, identified 12,415 gene clusters, of which 18.9% and 81.1% were core and accessory genes respectively. Average nucleotide identity (ANI) analysis demonstrated >99% sequence identity among all 55 B. licheniformis genomes, despite their isolation from diverse environments, indicating strong genomic conservation within the species. Experimental validation confirmed γ-PGA production by all four strains, with maximum titres (g/L) of 43.27 ± 1.49, 59.54 ± 4.33, 27.93 ± 1.87, and 47.74 ± 0.19 for DPC3803, DPC6338, DPC6339, and DPC6340, respectively. Genomic screening revealed multiple γ-PGA metabolism and CAZyme-encoding genes, as well as unique secondary metabolite clusters with potential antimicrobial activity. Although no plasmids or virulence factors were detected, twenty-one prophages were identified, sharing no significant homology with known cultivated phages, and a single β-lactamase gene suggested intrinsic resistance to β-lactams. These findings highlight the genomic and functional potential of these dairy-derived B. licheniformis as efficient, food-grade candidates for industrial γ-PGA production.

This review article examines divergent approaches by International Oil Companies (IOCs) to the energy transition away from fossil fuels. While these companies are subjected to similar pressures across comparable markets and operations, European IOCs have been adopting a more “progressive” approach to the transition by doing more to diversify into renewables: they have been moving into “electrons”. By contrast, American IOCs have made a more “conservative” bet on the resilience of global oil and natural gas demand: they have been staying with “molecules”. Based on this counterintuitive development, or “puzzle”, this review surveys existing literature on the IOCs in the energy transition with the aim to, 1) examining the evidence on divergence and existing explanations thereof, and 2) offer the concept of a distinct American “petroculture” as a useful analytical lens for understanding divergence among IOCs. Combining the insights of the petrocultures approach with conventional political economy accounts of the agency of IOCs provides a novel and multidisciplinary account of corporate agency in research on energy transitions. Reflecting on the nature and explanations for divergence between American and European IOCs will also indicate how these multinational companies may fare in the energy transition – which ones may prosper and which ones may decline – and whether we ought to expect divergence or convergence in their strategies over time.

• Recent engineering model developments imply that the growth rate exponents of mixing layers may be changed permanently by only a temporary application of strain. • This effect has been demonstrated using Large-Eddy Simulations, with good qualitative agreement with the engineering model. • Under compression, the mixing layer exhibits a substantially reduced growth rate exponent from θ = 0.279 to θ = 0.112 and increased mixing. Recent engineering models of turbulent mixing layers under strain imply that there may be a permanent modification of important mixing layer physics following a temporary application of strain. This paper presents a set of Implicit Large-Eddy Simulations of a canonical Richtmyer-Meshkov instability to explore the validity of this model result. The well-characterised θ -group quarter scale case is modified to include a strain rate which halves domain widths in approximately five eddy turnover times. Following the removal of strain, the observed value of the growth rate exponent θ = 0.112 which is a 2.5 times reduction compared with the unstrained case. Whilst θ is slowly rising at late time, the actual change in θ is qualitatively in good agreement with the engineering model but is quantitatively a much greater change than expected. Mixedness also increases significantly, from Θ = 0.8 for the unstrained to Θ = 0.9 following the application of strain. Turbulent kinetic energy substantially rises during strain, but then dissipates more rapidly following the removal of strain due to the decreased turbulent length-scales. Overall these results demonstrate that modifications to engineering models, such as those proposed by Pascoe et al. (Phys. Rev. Fluids 10 (6), 064609, 2025) are needed to capture these significant variations in flow physics which persist even following the removal of strain. The engineering model further predicts more substantial impacts at high overall compression or expansion as expected in typical applications in inertial confinement fusion, supernovae or explosions.

Peatlands represent important habitats for specialised species as well as vital carbon sinks. Ecological restoration of peatlands by government and NGOs has become an increasingly common approach to tackle their degradation, driven primarily by the climate change mitigation agenda targeting enhanced carbon storage and, secondarily, biodiversity conservation. We assessed biodiversity restoration of lowland raised bogs previously exploited for commercial horticulture substrate production. After industrial extraction, restoration of two exploited peatlands in Northern Ireland included laser-levelling, creation of bunded cells, seeding with donor material, and raising the water table to rewet each site in stages over a decade. Restored cells representing a 10-year chronosequence were compared to bare peat, unrestored areas, and protected, near-natural lowland raised bogs which were taken as reference sites. Bryophytes, including extensive Sphagnum moss lawns and raised hummocks, re-established quickly, alongside the swift recolonisation by vascular plants, particularly peatland specialists such as cottongrass (Eriophorum spp.). Changes in the invertebrate communities were less pronounced, although restored sites supported more aquatic and peatland specialists than reference sites. After 10 years, restored plots matched reference sites in taxonomic richness, and contained more hydrophilic taxa but slightly lower invertebrate abundance. Reference lowland raised bogs had been historically drained and hand-cut for turf pre-designation, and ongoing atmospheric nitrogen deposition from nearby farming may have influenced community composition, resulting in drying and succession to more heath-associated communities. Thus, restored commercially exploited lowland raised bogs can rapidly re-establish species-rich, peatland-like communities, demonstrating the clear biodiversity benefits of active restoration.

Model-Based Testing (MBT) was first introduced in 1970′s, and has the potential to improve efficiency and effectiveness of testing. However, its adoption—especially for web applications—has been hindered by the effort required to manually design MBT models, and keep them updated. Based on the above challenge in a real industrial context, this study introduces an automated approach to reduce that effort by reverse engineering MBT models from clickstream data captured during users' interaction with web applications. We have developed and present in this paper an open-source tool, named MBTModelGenerator , which logs user interactions via a lightweight JavaScript module in the front-end, and transmits them to a REST API backend. These interactions are then transformed into directly executable MBT models in the input format of an open-source MBT tool named GraphWalker . The tool was evaluated on two representative open-source web applications, Spring PetClinic and a Task Manager web app, and is under evaluation in several large-scale industrial testing projects. The generated MBT models accurately reflected user navigation flows and could be executed in the GraphWalker MBT tool without any manual changes. Using the tool has significantly reduced the effort of MBT model design by more than 90%, while still allowing test engineers to inspect and refine the generated models for completeness. Our approach facilitates lightweight adoption of MBT by automating model generation, which is the most effort intensive phase of MBT. To ensure correctness and completeness, the generated models should still be reviewed by test engineers —but that effort remains substantially lower than designing MBT models from scratch. The tool is in active industrial use and available as open-source for reuse and further development.