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Bouncing to coalescence transition for droplet impact onto moving liquid pools
Get PDFA droplet impacting a deep fluid bath is as common as rain over the ocean. If the impact is sufficiently gentle, the mediating air layer remains intact, and the droplet may rebound completely from the interface. In this work, we experimentally investigate the role of translational bath motion on the bouncing to coalescence transition. Over a range of parameters, we find that the relative bath motion systematically decreases the normal Weber number required to transition from bouncing to merging. Direct numerical simulations demonstrate that the depression created during impact combined with the translational motion of the bath enhances the air layer drainage on the upstream side of the droplet, ultimately favoring coalescence. A simple geometric argument is presented that rationalizes the collapse of the experimental threshold data, extending what is known for the case of axisymmetric normal impacts to the more general 3D scenario of interest herein
Correction: Psychiatrists effect on positive symptom severity and daily functioning during pharmacotherapy for first-episode psychosis patients
Get PDFCorrection to: Scientific Reportshttps://doi.org/10.1038/s41598-024-72678-4, published online 02 October 2024 The original version of this Article contained errors. During the production of the Article Dr Joran Lokkerbol and Dr Iris E.C. Sommer were erroneously omitted from the Author List. Additionally, Affiliation 11 “Centre of Economic Evaluations & Machine Learning, Trimbos Institute, Netherlands Institute of Mental Health and Addiction, Utrecht, The Netherlands” was also erroneously omitted from the original Affiliation list of the Article. The original Article has been corrected, and the Authors and Affiliation now appear as intended
Rationality Patterns in Export Promotion Organizations
Get PDFExport promotion organizations (EPOs) play an essential role in supporting global trade. Amid escalating global trade tensions, rising tariffs, and increased multipolarity, specialized teams within EPOs assume decision‐making functions guided by distinct rationalities. The aim of this research was to identify the different rationalities within EPOs and determine the factors contributing to their variations. Using a mixed method approach, we assessed the rationalities of these teams and show demonstrable differences. Key influencing factors are primarily rooted in the organizational context: institutional guidelines, perceived trends and challenges, and organizational goals. Our analysis reveals three different clusters reflecting differences between corporate‐oriented, government‐oriented, and independent rationality. Understanding these distinct rationalities provides valuable insights for policymakers and practitioners seeking to enhance organizational effectiveness in navigating contemporary global trade challenges
Demographic buffering in natural populations: A multi‐level perspective
Get PDFEnvironmental stochasticity poses significant challenges to population persistence. A key mechanism thought to buffer populations against such variability is demographic buffering—the ability of a population to stabilise growth despite temporal fluctuations in survival, development or reproduction. However, empirical tests of demographic buffering remain limited and often yield conflicting results. Here, we propose an integrative demographic framework that combines two complementary approaches to identify demographic buffering: (1) stochastic elasticities, which quantify the sensitivity of long‐term stochastic growth rates (λs) to variance in demographic processes, and (2) second‐order derivatives of deterministic growth (λ₁), which indicate whether selection acts to reduce or amplify variance in vital rates. Applying this framework to 43 natural populations across 37 mammalian species, we position each species along a variance continuum and assess whether those with low stochastic elasticities—suggestive of buffering—also exhibit signs of concave selection on key demographic processes. While most primates and a few other long‐lived mammals occupy the buffered end of the continuum, only one species—the Columbian ground squirrel—exhibits strong support for our hypothesis, with key vital rates both critical for λ₁ and under concave selection. In contrast, primates, despite showing low stochastic elasticities, often show convex or absent second‐order effects on their most influential vital rates, indicating a mismatch between ecological buffering and evolutionary constraint. Our findings suggest that demographic buffering is more dynamic and context dependent than previously recognised. Selection does not consistently act to reduce variance in key demographic processes, even in species where population growth appears robust to environmental variability. This decoupling implies that evolutionary and ecological signals of buffering may not always align. Our framework offers a new lens to dissect the demographic and selective processes underpinning resilience, providing a scalable tool for exploring demographic strategies across taxa. Future work integrating phylogenetic context, trait covariation and environmental drivers will be essential to understand the adaptive value of demographic buffering under global change
Operationalising artificial intelligence bills of materials for verifiable AI provenance and lifecycle assurance
Get PDFIntroduction: Artificial intelligence (AI) systems increasingly rely on complex, multi-layered software supply chains, creating substantial challenges for reproducibility, transparency, and security assurance. Existing software bills of materials inadequately capture AI-specific artefacts such as model lineage, training provenance, and disclosure metadata, limiting verifiable lifecycle governance. Methods: This study proposes an Artificial Intelligence Bill of Materials (AIBOM) schema that extends the CycloneDX standard through structured schema engineering. The framework integrates cryptographic validation and agent-driven automation to enable machine-verifiable provenance. An autonomous AI pipeline was implemented to conduct continuous environment inspection, vulnerability enrichment, and reproducibility auditing across containerised analytic workflows. Results: Empirical evaluation demonstrates 98.7% reproducibility fidelity across replicated executions, 96.2% precision in vulnerability matching against reference datasets, and a 63% reduction in manual oversight compared with conventional documentation-based approaches. Discussion: The results demonstrate the feasibility of automated provenance assurance and reproducible AI lifecycle validation at scale. The proposed AIBOM framework strengthens software supply chain transparency, enhances provenance integrity, and provides a generalisable methodology for securing AI systems. It further supports alignment with international information security and compliance standards, advancing the scientific foundations of reproducibility engineering in AI-enabled systems
High-degree cubature on Wiener space through unshuffle expansions
Get PDFUtilizing classical results on the structure of Hopf algebras, we develop a novel approach for the construction of cubature formulae on Wiener space based on unshuffle expansions. We demonstrate the effectiveness of this approach by constructing the first degree-7 cubature formula on d-dimensional Wiener space with drift in the sense of Lyons and Victoir (Lyons & Victoir 2004 Stoch. Anal. Appl. Math. Finance460, 169–198) which is explicit as a function of an underlying Gaussian cubature. The support of our degree-7 formula is significantly smaller than that of currently implemented or proposed constructions
Response to Boudinot et al
No full textThe diversification of Hymenoptera is a transformative evolutionary story in insect evolution, fundamentally tied to major global events like the Mid-Mesozoic Parasitoid Revolution (MMPR) and the Angiosperm Terrestrial Revolution (ATR). The recent paper by Jouault et al.1 provided a first largescale quantifi cation of Hymenoptera diversifi cation using fossil occurrence data through two complementary Bayesian methods: PyRate, which models origination and extinction dynamics, and the Bayesian Brownian Bridge (BBB), which estimates clade origination and extinction ages. In a critique, Boudinot et al.6 raise concerns that our analyses overfi t a sparse fossil record, misinterpret extinction signals, and overlook the putative absence of a Permian Hymenoptera ghost lineage. However, these concerns were not accompanied by statistical tests. Moreover, the original methodological papers include extensive simulations and empirical evaluations explicitly designed to assess the robustness and behavior of these models under varying fossil recovery scenarios; we direct readers to those studies for full details. Here, we clarify our methodology and counter these claims. Far from undermining our work, the critique merely reiterates and highlights the interpretive caution that underpins our study
Climate policy portfolios that accelerate emission reductions
Get PDFThe corpus of national climate policies continues to grow - but to what effect? Using data on 3,917 policy instruments across 43 OECD countries and major emerging economies from 2000-2022, we show that national climate policy portfolios specializing in instrument types and sectors are associated with faster reductions in fossil CO2 emission intensity. Supported by exemplar country case studies, we also provide quantitative evidence that the effectiveness of climate policy is amplified by long-term emission reduction targets and the presence of dedicated governmental bodies including ministries and intergovernmental organisations. The cumulative effect of all climate policy portfolios over our study period amounts to 3.1 GtCO2 fewer emissions in 2022 relative to a no-policy counterfactual - substantially less than what’s needed to stay on track for the Paris Agreement goals
The southwest Kalahari dune field does not emit dust post‐fire despite a lack of vegetation and above‐threshold winds
Get PDFVegetated sand dunes are not typically considered to be significant sources of dust because of coarse grain sizes and high vegetation cover. Yet, plumes of dust have been observed from vegetated dune fields, and wind tunnel experiments show the potential for interdunes to emit dust. The partially vegetated southwest Kalahari is one such dune field that is vulnerable to climate‐driven land degradation and vegetation cover change and has been posited as a potential future dust source. In this study, we monitor the post‐fire de‐vegetated state of 11 interdunes to investigate the dust emission potential and erodibility controls on emission. Findings suggest that there is little emission of dust despite a fine‐grain component (up to 30% of resident grains 7 m s−1) post‐fire. Erosive wind events were less frequent compared to other dust‐producing regions, with wind speeds generally under 7 m s−1. Five high wind speed events over 7 m s−1 were recorded in September 2022, the month immediately following burning, but even then, only one event had a concurrent increase in aerosol concentration. This is indicative of other erodibility factors limiting dust emission. These include high (>50%) burned debris cover in the immediate post‐fire period and evidence of biological soil crusts that survived burning. Both protect the surface after fire whilst the natural vegetation cover recovers. Combined, the general low wind speeds, high initial surface cover, and the protective effect of biocrusts result in a low probability of the southwest Kalahari emitting dust post‐fire. However, fine‐grain sizes and low vegetation cover under drought and high grazing may lead to conditions conducive for dust emission