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Decoding the chemistry of the FLASH effect:a physicochemical model of dose-rate, pH and oxygen-dependent H₂O₂ production
No full text Objective.To elucidate the initial chemical mechanisms that may underlie the FLASH effect by developing and validating a unified simulation framework for the radiolysis of pure water. The goal is to create a single model capable of reconciling conflicting experimental and simulation data regarding H₂O₂ production and explaining key radiobiological observations across conventional (CDRs) and ultra-high dose rates (UHDRs) under varied oxygenation levels. Approach.An ordinary differential equation-based model was developed to simulate the homogeneous chemistry phase of water radiolysis. The framework incorporates a detailed chemical reaction network and a novel description of acid-base equilibrium, allowing pH to evolve dynamically. A key innovation is the integration of an empirically derived, dose-rate dependent G-value coefficient ( G F( D R)) that anchors the simulation to experimental data. The temporal evolution of key species (H₂O₂, O₂, H₃O +, OH -) is tracked to investigate the impact of dose rate and oxygen concentration. Main results.The model reproduces two key experimental findings relevant to the FLASH effect-previously challenging for simulations: decreased net H₂O₂ production at UHDR under physioxic conditions. This reduction (vs CDR) aligns with normal tissue sparing, while hypoxic (tumour-like) conditions show comparable H₂O₂ production at UHDR and CDR, consistent with iso-tumour control. These results confirm that H₂O₂ radiochemistry is profoundly influenced by both dose rate and oxygen levels. Significance.This work resolves a key discrepancy between previously published simulations and experimental data on UHDR water radiolysis. The model provides a robust, mechanistic foundation linking the physical parameter of dose rate to the distinct chemical environments that likely drive the differential biological outcomes of the FLASH effect. It serves as a powerful new tool for investigating the complex interplay between dose rate, oxygenation, and radiolytic chemistry. </p
Analyse de pratiques, évaluation et rapport à la (aux) norme (s):quels risques? de déprofessionnalisation(s)?
No full text‘Why speak you this broken French when y’are a whole Englishman?’:French, Travelling, Self-Satire, and Cultural Mediation in London City Comedy
Get PDFGiven the widely multicultural and multilingual context of seventeenth-century London and the central role of French culture and language in Renaissance England, it comes as no surprise that a number of the highly topographical Jacobean city comedies contain French scenes. Drawing on Niayesh’s argument that French often served as a cultural and linguistic mediator between England and further, ‘exotic’ destinations in early modern drama (Niayesh 2008), this paper explores the links between French and travelling in two city comedies, Eastward Ho! and Anything for a Quiet Life. Exploring how and why staged French and Frenchmen are linked to the issue of England’s new, growing role as a colonising, global power and to the consequences of this role on London’s cosmopolitanism, it argues that French, often staged in the plays as spoken by Englishmen, is regularly used to criticize, comment on, or warn against superficial attitudes of Londoners toward ‘Others’. Linking the traditional analysis of city comedies as satirical plays criticizing English attitudes with scholarship on travel drama, it suggests that French in city comedies may be used as a means to make sense of an ever-evolving early modern English society which felt increasingly foreign or alienating. This paper thus follows McManus’s broad definition of the term ‘travel drama’, which is not restricted to plays staging trips in foreign countries represented as ‘exotic’ but also includes any play which is ‘in some way concerned with the motivations and consequences of travel’ (2018), and argues that the inclusion of plays set in London in this category is therefore contradictory solely in appearance
Aid allocation with optimal monitoring:Theory and policy
Get PDFWe explore the implications of allowing a poverty-averse donor to monitor aid use within the familiar context of the needs vs. aid effectiveness tradeoff. The paper focuses on the optimal aid allocation between two countries when the donor simultaneously decides about aid shares and country-specific monitoring effort aimed at increasing the amount reaching the poor. Endogenizing aid effectiveness is shown to raise the poor's income in the worse-governed country, yet not necessarily in the better-governed one, whereas the effect on country aid shares is essentially ambiguous. Those results still hold when the basic model is extended in various directions. Conventional aid allocation rules should be re-examined in their light.</p
Rethinking Paradigmatic Collaboration:A New Metric for Inter-paradigm Synergy in Software Engineering
No full textThis paper introduces two novel metrics for assessing collaboration potential between programming paradigms and languages, offering a fresh approach to evaluating inter-paradigm interactions. The quantitative framework introduced challenges traditional methods by highlighting both the opportunities and the challenges of integrating paradigms with varying characteristics. Initial findings suggest that the metric effectively captures collaboration within similar paradigms, with functional paradigms demonstrating particularly strong collaboration potential. However, it also underscores the complexity of unifying divergent paradigms. The goal of this paper is to provoke discussion and foster further research, such as the refinement of metrics to obtain useful measurements in technology selection steps and interdisciplinary software development.<br/
Topology shapes dynamics of higher-order networks
No full textHigher-order networks capture the many-body interactions present in complex systems, shedding light on the interplay between topology and dynamics. The theory of higher-order topological dynamics, which combines higher-order interactions with discrete topology and nonlinear dynamics, has the potential to enhance our understanding of complex systems, such as the brain and the climate, and to advance the development of next-generation AI algorithms. This theoretical framework, which goes beyond traditional node-centric descriptions, encodes the dynamics of a network through topological signals—variables assigned not only to nodes but also to edges, triangles and other higher-order cells. Recent findings show that topological signals lead to the emergence of distinct types of dynamical state and collective phenomena, including topological and Dirac synchronization, pattern formation and triadic percolation. These results offer insights into how topology shapes dynamics, how dynamics learns topology and how topology evolves dynamically. This Perspective primarily aims to guide physicists, mathematicians, computer scientists and network scientists through the emerging field of higher-order topological dynamics, while also outlining future research challenges
