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The timing and ecological consequences of the late Pleistocene megafaunal declines on the Isthmus of Panama: Implications for trophic rewilding
Get PDFThe timing and ecological consequences of Late Quaternary megafaunal extinctions in Central America remain poorly resolved, limiting our understanding of how the Pleistocene megafaunal declines may have influenced past and present ecosystem dynamics and ecological processes. To address this gap, we applied a high-resolution multiproxy palaeoecological approach to reconstruct the Pleistocene megafaunal presence in the Isthmus of Panama. Lake sediment cores from Lake La Yeguada were analysed for spores of coprophilous fungi (SCF) using a multi-genus SCF approach; an analytical advancement that significantly improves the resolution and reliability of megafaunal reconstructions compared to traditional reliance on Sporormiella alone. This multi-genus SCF approach was integrated with fossil pollen and charcoal analyses to establish the first detailed record of megafaunal presence/absence, vegetation dynamics, and fire activity, respectively, spanning the Late Pleistocene to the Holocene in Panama. Our SCF record indicates that megafauna were present in the region from at least 16,600 cal yr BP (calibrated years before present) and underwent three distinct phases of decline around 13,600, 10,000, and 8400 cal yr BP. These declines were followed by recoveries at 11,200, 9000 cal and 7600 cal yr BP, likely caused by changes in megafaunal community compositions. These transitions coincided with shifts in vegetation composition between forest and grasslands, marked by the loss of large-seeded, megafaunal-dispersed plant taxa and increased fire activity, suggesting that megafaunal decline had cascading impacts on ecosystem processes in Panama. Our findings highlight the ecological consequences of megafaunal declines on megafaunal-dispersed and large-seeded plants and suggest that future declines could have implications for vegetation and fire activity. These insights provide a valuable baseline to inform conservation strategies for extant species and offer guidance for future trophic rewilding efforts aimed at restoring ecological functions lost with the extinction of Pleistocene megafauna
The transfer of 98% of the genome of Aegilops mutica into wheat (Triticum aestivum)
Get PDFKey message: New wheat-Ae. mutica introgression lines will deliver new genetic variation for hexaploid wheat breeding and provide new information on the distribution of homoeologous recombination between wheat and Ae. mutica. Abstract: Aegilops mutica Boiss. (2n = 2 × = 14, TT) is a wild relative of wheat that has been underutilised as a source of genetic variation for hexaploid wheat Triticum aestivum L. (2n = 6 × = 42; AABBDD), despite its potential to harbour important genetic diversity for a wide range of agronomically valuable traits. This species has been extensively exploited by the Wheat Research Centre (WRC) at the University of Nottingham to create a diverse resource of wheat-Ae. mutica introgression lines. In this study, we present the most comprehensive transfer of the Ae. mutica genome into wheat to date, with 98% of the genome now present in wheat through the development of new wheat–Ae. mutica introgression lines. These 68 new lines, comprising 57 unique Ae. mutica introgressions, have been characterised using kompetitive allele-specific PCR (KASP) genotyping, multi-colour genomic in situ hybridisation and low coverage whole-genome sequencing. This thorough characterisation has revealed the distribution of homoeologous recombination sites between wheat and Ae. mutica chromosomes, uncovering recombination “hotspots” and novel introgressed segments that were previously undetectable using conventional genotyping methods. This resource significantly expands the genetic diversity available for wheat improvement and offers a powerful platform for linking traits to specific genotypes. The creation and characterisation of this near-complete set of Ae. mutica introgressions will be invaluable for wheat researchers and breeders worldwide
Worlding otherwise: Virtual production as a participatory method for imagining safer digital futures
Get PDFThis article demonstrates the capability of Virtual Production (VP) technologies and techniques as new, and potentially very powerful, research tools. We do so through a case study in which a multi-user Virtual Reality (VR) environment was created so that participants could come and explore the troubling topic of online misogyny, sexism and antifeminism in a co-created, playful and embodied way. For this project, the interdisciplinary team developed a multi-stage methodology to deliver a critical, participatory research intervention using VP. Secondary data about participants’ lived experiences of online misogyny, the coping mechanisms they deploy in these situations and the in-built biases and failures of platform regulation that they identify was used to sensitise the case study. Participants’ ideas about familiar and fantastical environments, multiple spaces for creativity and collaboration with variable privacy levels, and customisable avatars for identity expression were used for inspiration by a dramaturg and creative technologist, who worked together to devise a virtual environment and activities for multiple users to explore together in VR. This took place during an all-day in-person workshop with eight participants at a University-based innovation and research driven VP studio. Through facilitated activities and reflective discussions, the participants and research team co-created positive interactions and experiences in the virtual environment based on clear, shared rules, cooperation around tasks, mutual learning and purposeful movement between online and offline contexts. We present this case study to share these findings, and to serve as a template for other researchers who could use VP to prototype provocative scenarios and devise socio-technical alternatives in response to different research questions
Efficiently predicting pressure-composition-temperature diagrams to discover low-stability metal hydrides
Get PDFQuantitatively accurate computational predictions of metal hydride thermodynamics are challenging but critical for alloy performance optimization across a multitude of technological domains, including hydrogen storage, compression, purification, and getters. Recent machine learning approaches have demonstrated great success in this area, but can potentially suffer from several shortcomings since they rely on imbalanced experimental training data and can have poor out-of-distribution (ood) test performance. Here we circumvent such pitfalls by developing a computationally efficient, first principles-based workflow for direct prediction of metal hydride phase equilibrium, i.e., the pressure-composition-temperature (PCT) diagram. We then demonstrate its utility on predicting low stability hydrides derived from compositionally complex C14 Laves phase AB2 alloys. Specifically, we computationally predict and then experimentally validate an AB2 alloy series (z < 0.6 for Ti2−zZrzCrMnFeNi) with ideal hydriding thermodynamics for a two-stage metal hydride-based compressor for pressurizing boil off from liquefied hydrogen. Importantly, this study lays the groundwork for accurate and efficient discovery/optimization of ood, low-stability hydrides for which purely data-driven approaches lack sufficient accuracy
Modelling complexity in system safety: generalizing the D2T2 methodology
Get PDFFault Tree (FT) and Event Tree (ET) analysis remain the most widely adopted methods for system safety assessment, valued for their efficiency and transparency. However, their static structure and assumption of independent basic events limit their ability to represent dynamic behaviours and dependencies, particularly in modern systems where control, automation, and shared resources play a central role. Existing extensions and alternatives improve expressiveness but often at the expense of generality, interpretability, or computational feasibility. The Dynamic and Dependent Tree Theory (D2T2) addresses these shortcomings by preserving the global FT/ET structure while enabling dependencies to be represented at multiple levels of fidelity. In this work, we propose an extension that generalizes the framework to directly capture subsystem and train level dependencies, thereby avoiding decomposition to basic event interactions that would otherwise exacerbate model complexity and state space growth. This capability places virtually no restriction on dependency type or location, and retains FT/ET traceability essential for review and certification purposes. By offering a continuum of modelling choices between classical FT/ET and fully dynamic formalisms, D2T2 provides a distinctive contributio
Characterisation and modelling of ductile fracture in incremental sheet forming of an aluminium alloy with consideration of temperature variations
Get PDFAlthough extensive studies have been conducted to predict ductile fracture at room temperature, no attempt has been made to use Gurson–Tvergaard–Needleman (GTN) model to capture the effect of temperature due to spindle speed induced friction heat on damage accumulation in incremental sheet forming (ISF). In this work, the temperature effect is incorporated into a shear modified GTN model to characterise ductile fracture behaviour of an aluminium alloy (AA1050) at varying temperatures in ISF processing under different strain states. The correlation between void evolution and damage accumulation at different temperatures is revealed, and the void volume fraction (VVF) at different deformation stages is determined by conducting microscopic in-situ tensile test. By introducing a new temperature-dependent VVF function and determining appropriate GTN damage parameters, ductile fracture under different ISF processing temperatures is evaluated using FE simulation and validated by ISF experimental testing. The results show that the proposed temperature-dependent VVF function in GTN modelling is capable of predicting the ductile fracture of both the set temperatures in in-situ tensile tests and the varying temperature conditions in ISF processes. This study unveils the underlying mechanisms behind material deformation and damage evolution with consideration of temperature variations caused by tool spindle speed at various ISF forming conditions, which provides guidance for process optimisation and formability improvement in ISF process
Optical coherence tomography features of the graft–host junctions after deep anterior lamellar keratoplasty: Long-term changes
Get PDFPurpose: The wound healing process in the graft–host junction (GHJ) after deep anterior lamellar keratoplasty (DALK) can affect the outcome. We studied the anterior segment optical coherence tomography (OCT) features of the GHJ in the early and late postoperative stages.Methods: OCT scans for 45 eyes of 43 patients within 4 weeks of DALK between 2014 and 2023 were retrospectively examined. Sixteen of these had a second scan 2 years or later postsurgery. GHJ profile, thickness, suture tracks, alignment (steps and shelves), and epithelial changes were examined and compared between early and late scans.Results: The GHJ profile at 2 to 4 weeks postoperative was perpendicular (7 eyes, 43.7%), zigzag (4 eyes), C shaped (4 eyes), or mixed (1 eye). These profiles were persistent in most of the eyes (13 eyes, 81.2%) in the late scans. The thickest region was predominantly in the graft (13 eyes, 81.2%). This disparity disappeared in the late scans. Suture tracks were seen as hyper-reflective lines which remained visible in the late scans even after suture removal. Five eyes (31.2%) had anterior and 1 eye (0.6%) had posterior graft steps which disappeared in the late scans. Host shelves were seen in 43.3% in the first scan, and all of them had disappeared or became attenuated in the late scan.Conclusions: These findings can help surgeons assess their technique to reduce misalignment which could influence the outcomes and improve the understanding of the effect of the wound healing process in the GHJ
Longitudinal survey of 6-monthly booster vaccination-induced antibody responses to equine influenza A virus (H3N8) in Standardbred trotting horses in training
Get PDFVaccination is an established and important tool in preventing the impact of influenza in the horse population but the frequency of booster vaccinations after the primary course of vaccinations to maintain protective antibody levels is still under debate. The aim of this field study was to monitor equine influenza antibody levels over the course of 13 months during which horses were given two booster vaccinations. Fifty-six vaccinated Standardbred trotters in training were monitored with monthly blood samples. The horses were routinely vaccinated with a commercial equine influenza vaccine 6 months apart, V1 and V2. Antibodies to vaccine strain A/equine/Borlänge/91 (Bor/91) were quantified by ELISA in all samples and also measured by single radial haemolysis (SRH) in samples obtained before and after V1. Mean titres against Bor/91 determined by ELISA were at the lowest level in the month prior to V1. All horses sampled immediately before and after V1 had an increase in titre except two ≥ 4-year-old horses. The antibody titres declined rapidly in the 3 months after V1. The boosting effect of V2 was lower compared to that of V1 and six horses with high pre-vaccination titres did not respond to V2, irrespective of age. Titres estimated by ELISA correlated well with antibody levels determined by SRH, which showed that while many of the horses would be unprotected before V1, antibody levels were boosted to protective levels after vaccination. Antibody responses were higher in horses with low antibody levels at booster vaccination compared to those with already high antibody levels
Cognitive interference in the learning of multiplication facts
No full textFluency with multiplication facts provides a strong foundation for future mathematics learning. Models of number fact storage and retrieval suggest that multiplication facts are stored in an associative network whereby neighbouring facts (e.g. 6 × 7 and 6 × 8) can interfere with one another. While existing theoretical models account for the skilled retrieval of number facts, an understanding of how interference develops during learning, and hence the need for inhibitory control during learning, is poor. In a pre-registered study, we tracked adults as they learnt a set of new multiplication facts and we monitored the interference between facts throughout their learning. Our findings are the first to show that interference emerges early in the learning process as individuals acquire knowledge of new facts. Moreover, interference does not decline as learning continues, even when retrieval accuracy is high and individuals are continuing to practice facts that they already know. These findings are consistent with theoretical assumptions and models of multiplication fact networks proposed by Ashcraft (1987), Campbell (1995) and De Visscher et al., (2016), but do not support the model proposed by Verguts & Fias (2005)
The results of ProHCL: Patient-reported outcomes in people living with type 1 diabetes on hybrid closed-loop insulin pump therapy − experiences from the NHS England pilot
No full textAims: This study evaluated the impact of ≥3 months of HCL use on patient-reported outcomes (PROs) in PwT1D and their partners.Methods: Participants enrolled on the NHS England HCL pilot were invited to take part in a mixed-methods study. Here, we present the results of the quantitative study. PwT1D completed online questionnaires, including INSPIRE (0–100), DTSQc (− 18 to +18), System Usability Scale (0–100), and bespoke measures. Self-reportedclinical data were collected. Optionally, partners completed the INSPIRE for partners questionnaire.Results: A total of 125 PwT1D and 33 partners participated. PROs included: INSPIRE 88/100 (IQR 73–95) and DTSQc 17/18(14–18). In INSPIRE, >70 % strongly agree that HCL improved HbA1c, time in range and overall quality of life. In DTSQc, >70 % noted that their blood glucose levels had been unacceptably low/high much less of the time since starting HCL. However, 54.4 % reported increased alarm burden and 21.6 % information overload. People who found HCL harder to use based on the SUS score had lower INSPIRE, DTSQs and DTSQc scores and higher HbA1c than those who found HCL easier to use.Conclusions: HCL therapy is associated with improved PROs in PwT1D. However, system usability significantly influences outcomes, and alarm and data burden remain concerns
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