On some fundamental results about higher-rank graphs and their C*-algebras

Results of Fowler and Sims show that every k-graph is completely determined by its k-coloured skeleton and collection of commuting squares. Here we give an explicit description of the k-graph associated to a given skeleton and collection of squares and show that two k-graphs are isomorphic if and only if there is an isomorphism of their skeletons which preserves commuting squares. We use this to prove directly that each k-graph {\Lambda} is isomorphic to the quotient of the path category of its skeleton by the equivalence relation determined by the commuting squares, and show that this extends to a homeomorphism of infinite-path spaces when the k-graph is row finite with no sources. We conclude with a short direct proof of the characterisation, originally due to Robertson and Sims, of simplicity of the C*-algebra of a row-finite k-graph with no sources.Comment: 21 pages, two pictures prepared using TiK

Pre-Clinical Assessment of Single-Use Negative Pressure Wound Therapy During In Vivo Porcine Wound Healing

Objective: Traditional negative pressure wound therapy systems can be large and cumbersome, limiting patient mobility and adversely affecting quality of life. PICO™, a no canister single-use system offers a lightweight, portable alternative to traditional negative pressure wound therapy, with improved clinical performance. The aim of this study was to determine the potential mechanism(s) of action of single-use negative pressure wound therapy versus traditional negative pressure wound therapy.Approach: Single-use negative pressure wound therapy and traditional negative pressure wound therapy were applied to in in vivo porcine excisional wound model, following product use guidelines. Macroscopic, histological and biochemical analyses were performed at defined healing time-points to assess multiple aspects of the healing response. Results: Wounds treated with single-use negative pressure displayed greater wound closure and increased re-epithelialisation versus those treated with traditional negative pressure. The resulting granulation tissue was more advanced with fewer neutrophils, reduced inflammatory markers, more mature collagen and no wound filler-associated foreign body reactions. Of note, single-use negative pressure therapy failed to induce wound edge epithelial hyperproliferation, while traditional negative pressure therapy compromised peri-wound skin, which remained inflamed with high transepidermal water loss; features not observed following single-use treatment. Innovation: Single-use negative pressure was identified to improve multiple aspects of healing versus traditional negative pressure treatment.Conclusion: This study provides important new insight into the differing mode of action of single-use versus traditional negative pressure and may go some way to explain the improved clinical outcomes observed with single use negative pressure therapy

Use of electrical resistivity tomography to reveal the shallow freshwater–saline interface in The Fens coastal groundwater, eastern England (UK)

The Fens is a region that contributes 11% of the agri-food economy from just 4% of the agricultural land covering England (UK). This region is vulnerable to soil salinisation from sea-level rise with estimated 100-year flood events projected to be observed up to every 2 years by 2100. Seawater intrusion and upwelling of saline groundwater can provide an additional pathway; however, the area’s groundwater has not been assessed and the risk is unknown. This study used data from the British Geological Survey’s stratigraphic core archive to produce the first stratigraphic map of the loosely consolidated Holocene deposits in the South Holland–Holbeach Marsh region. There is a sandy unconfined aquifer towards the coast, a semiconfined central region with a silty cap and a clay confining cap in the north region. Electrical resistivity tomography data indicate water level depths of 0.58 ± 0.37 m above mean sea level (msl) in February 2021 and 0.01 ± 0.72 m msl in August 2021. The saline–freshwater boundary was at 1.70 ± 0.82 m msl in February 2021, deepening to 2.00 ± 1.02 m msl in August 2021, but the only evidence of seasonal fluctuation was within 10 km of the coast. A potential, but unverified, freshwater lens up to 3.25 m thick may exist beneath the surface. These results suggest that freshwater–saline interface fluctuations may primarily be driven by surface hydrology and would be vulnerable to climate-change-induced future variations in factors that affect surface water

Characterization of chilling-shock responses in four genotypes of Miscanthus reveals the superior tolerance of M. × giganteus compared with M. sinensis and M. sacchariflorus

Abstract Background and Aims The bioenergy grass Miscanthus is native to eastern Asia. As Miscanthus uses C4 photosynthesis, the cooler temperatures experienced in much of northern Europe are expected to limit productivity. Identification of genetic diversity in chilling tolerance will enable breeders to generate more productive varieties for these cooler regions. Characterizing the temporal relationships between photosynthesis, carbohydrate and molecular expression of relevant genes is key to understanding genotypic differences in tolerance or sensitivity. Methods To characterize chilling responses in four Miscanthus genotypes, plants were exposed to a sudden reduction in temperature. The genotypes studied comprised of two M. sinensis, one M. sacchariflorus and one inter-species hybrid, M. × giganteus. Changes in photosynthesis (Asat), carbohydrate composition and the expression of target transcripts were observed following chilling-shock. After 4 d the decline in leaf elongation rate (LER) in the different genotypes was measured. Results Following chilling-shock the greatest decline in Asat was observed in M. sacchariflorus and one M. sinensis genotype. Carbohydrate concentrations increased in all genotypes following chilling but to a lesser extent in M. sacchariflorus. Two stress inducible genes were most highly expressed in the genotypes that experienced the greatest declines in Asat and LER. Miscanthus × giganteus retained the highest Asat and was unique in exhibiting no decline in LER following transfer to 12 °C. Conclusions Miscanthus × giganteus exhibits a superior tolerance to chilling shock than other genotypes of Miscanthus. The absence of sucrose accumulation in M. sacchariflorus during chilling-shock suggests an impairment in enzyme function. A candidate transcription factor, MsCBF3, is most highly expressed in the most sensitive genotypes and may be a suitable molecular marker for predicting chilling sensitivity

Airport infrastructure planning to support sustainable aviation

Decarbonisation of the air transport sector is expected to be delivered through a combination of efficient aircraft and engine designs, low-carbon fuels such as sustainable aviation fuels (SAF), and zero carbon technologies, such as electric and hydrogen propulsion. The move toward low-carbon fuels and technologies is expected to pose a significant challenge to airport infrastructure requirements. The introduction of novel aircraft technologies will require complementary ground infrastructure at airports capable of supporting the transition at pace. Focused on electric flight, this paper proposes a holistic methodology that utilises historic airport logs, technological progression, along with aircraft mission feasibility to assess the airport infrastructure requirements over time. The methodology incorporates technology uncertainty and its effect on sustainable aviation. The main objective within the methodology is to project associated infrastructure requirements and fleet energy costs to enable planning support for decarbonisation transition pathways. The paper demonstrates the use of the proposed methodology using real-world historic flight logs, identifying the progression in energy demand and ground infrastructural requirements in five-year horizons up to 2050. The methodology presented in this paper and associated results will help airport operators, airline operators, and policymakers by providing planning support through such technology pathway projection

Identification of the factors associated with outcomes in a condition management programme

<p>Background: A requirement of the Government’s Pathways to Work (PtW) agenda was to introduce a Condition Management Programme (CMP). The aim of the present study was to identify the differences between those who engaged and made progress in this telephone-based biopsychosocial intervention, in terms of their health, and those who did not and to determine the client and practitioner characteristics and programme elements associated with success in a programme aimed at improving health.</p> <p>Methods: Data were obtained from the CMP electronic spreadsheets and clients paper-based case records. CMP standard practice was that questionnaires were administered during the pre- and post-assessment phases over the telephone. Each client’s record contains their socio-demographic data, their primary health condition, as well as the pre- and post-intervention scores of the health assessment tool administered. Univariate and multivariate statistical analysis was used to investigate the relationships between the database variables. Clients were included in the study if their records were available for analysis from July 2006 to December 2007.</p> <p> Results: On average there were 112 referrals per month, totalling 2016 referrals during the evaluation period. The majority (62.8%) of clients had a mental-health condition. Successful completion of the programme was 28.5% (575 “completers”; 144 “discharges”). Several factors, such as age, health condition, mode of contact, and practitioner characteristics, were significant determinants of participation and completion of the programme. The results showed that completion of the CMP was associated with a better mental-health status, by reducing the number of clients that were either anxious, depressed or both, before undertaking the programme, from 74% to 32.5%.</p> <p>Conclusions: Our findings showed that an individual's characteristics are associated with success in the programme, defined as completing the intervention and demonstrating an improved health status. This study provides some evidence that the systematic evaluation of such programmes and interventions could identify ways in which they could be improved.</p&gt

Delivering distribution system flexibility through micro-resilience

This study introduces the specific grid challenges faced at each of four micro-resilence sites and provides an overview of the innovative technical solutions deployed to improve grid flexibility, resilience and improve the distribution system operator customer experience. The sites were chosen due to their remote locations and reliance on a reliable electrical service due to dependent customers or lifesaving functions. Therefore, in addition to providing flexible grid services, when grid connected, there is also the opportunity to provide a reliable electrical supply to islanded pockets when there are high-voltage grid outages. The solution architecture and functions of technology such as the two-terminal power electronic devices (PEDs) and microgrid controller (MGC) are described. The combination of an energy storage system, distributed energy resources and PEDs will provide essential grid support functionality with co-ordination of devices, islanded status and data logging handled by a dedicated MGC. Also presented is the application of the Open Field Message Bus, open-standards communications framework for a field message bus, and a description of the specific interoperability use cases demonstrated within the project. This study provides valuable insights into a leading innovation project, delivered on operational networks to address practical customer issues through flexibility