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Scaling limits for a population model with growth, division and cross-diffusion
No full textInternational audienceOriginally motivated by the morphogenesis of bacterial microcolonies, the aim of this article is to explore models through different scales for a spatial population of interacting, growing and dividing particles. We start from a microscopic stochastic model, write the corresponding stochastic differential equation satisfied by the empirical measure, and rigorously derive its mesoscopic (mean-field) limit. Under smoothness and symmetry assumptions for the interaction kernel, we then obtain entropy estimates, which provide us with a localization limit at the macroscopic level. Finally, we perform a thorough numerical study in order to compare the three modeling scales
A budget impact analysis of a digital monitoring solution in patients treated with oral anticancer agents: a medico-economic analysis of the randomized phase 3 CAPRI trial
No full textInternational audienceBackground/objectives: Remote patient monitoring (RPM) has demonstrated numerous benefits in cancer care, including improved quality of life, overall survival, and reduced medical resource use. This study presents a budget impact analysis of a nurse navigator-led RPM program, based on the CAPRI trial, from the perspective of the French national health insurance (NHI). The study aimed to assess the impact of the program on medical resource utilization and costs.Methods: Medical resource utilization data were collected from both medico-administrative sources and patient-reported questionnaires. Costs were calculated by applying unit costs to resource utilization and estimating the average monthly cost per patient. Sensitivity analyses were conducted to explore different perspectives and varying resource consumption.Results: The analysis included 559 cancer patients participating in the CAPRI program. From the NHI perspective, the program resulted in average savings of €377 per patient over the 4.58-month follow-up period, mainly due to reduced hospitalizations. The all-payers perspective yielded even greater savings of €504 per patient. Sensitivity analyses supported the robustness of the findings.Conclusion: The budget impact analysis demonstrated that the CAPRI RPM program was associated with cost savings from the perspective of the NHI. The program's positive impact on reducing hospitalizations outweighed the additional costs associated with remote monitoring. These findings highlight the potential economic benefits of implementing RPM programs in cancer care. Further research is warranted to assess the long-term cost-effectiveness and scalability of such programs in the real-world settings
The center-symmetric Landau gauge meets the lattice
No full textInternational audienceA lattice implementation of the recently introduced center-symmetric Landau gauge is discussed and its predictions confronted with numerical Monte Carlo simulations. It is shown that the link average and the link correlators computed in that gauge are order parameters of the confinement-deconfinement transition at nonzero temperature. Strictly speaking, this requires a specific treatment of the Gribov copies that we discuss in detail. The numerical simulations comply with the theoretical predictions for the link average computed below and above the deconfinement temperature. Our results show that, within appropriately chosen gauges, one can construct local order parameters for center symmetry, as proxies for the non-local Polyakov loop
On the approximation of the von Neumann equation in the semi-classical limit. Part I : numerical algorithm
No full textInternational audienceWe propose a new approach to discretize the von Neumann equation, which is efficient in the semi-classical limit. This method is first based on the so called Weyl’s variables to address the stiffness associated with the equation. Then, by applying a truncated Hermite expansion of the density operator, we successfully handle this stiffness. Additionally, we develop a finite volume approximation for practical implementation and conduct numerical simulations to illustrate the efficiency of our approach. This asymptotic preserving numerical approximation, combined with the use of Hermite polynomials, provides an efficient tool for solving the von Neumann equation in all regimes, near classical or not
CParty: Hierarchically Constrained Partition Function of RNA Pseudoknots
No full textInternational audienceBiologically relevant RNA secondary structures are routinely predicted by efficient dynamic programming algorithms that minimize their free energy. Starting from such algorithms, one can devise partition function algorithms, which enable stochastic perspectives on RNA structure ensembles. As the most prominent example, McCaskill's partition function algorithm is derived from pseudoknot-free energy minimization. While this algorithm became hugely successful for the analysis of pseudoknot-free RNA structure ensembles, as of yet there exists only one pseudoknotted partition function implementation, which covers only simple pseudoknots and comes with a borderline-prohibitive complexity of O(n^5) in the RNA length n. Here, we develop a partition function algorithm corresponding to the hierarchical pseudoknot prediction of HFold, which performs exact optimization in a realistic pseudoknot energy model. In consequence, our algorithm CParty carries over HFold's advantages over classical pseudoknot prediction to characterizing the Boltzmann ensemble at equilibrium. Given an RNA sequence S and a pseudoknot-free structure G, CParty computes the partition function over all possibly pseudoknotted density-2 structures G ∪ G ′ of S that extend the fixed G by a disjoint pseudoknot-free structure G ′ . Thus, CParty follows the common hypothesis of hierarchical pseudoknot formation, where pseudoknots form as tertiary contacts only after a first pseudoknotfree 'core' G and we call the computed partition function hierarchically constrained (by G). Like HFold, the dynamic programming algorithm CParty is very efficient, achieving the low complexity of the pseudoknot-free algorithm, i.e. cubic time and quadratic space. Finally, by computing pseudoknotted ensemble energies, we unveil kinetics features of a therapeutic target in SARS-CoV-2
String Theory in a Pinch: Resolving the Gregory-Laflamme Singularity
No full textInternational audienceThin enough black strings are unstable to growing ripples along their length, eventually pinching and forming a naked singularity on the horizon. We investigate how string theory can resolve this singularity. First, we study the string-scale version of the static non-uniform black strings that branch off at the instability threshold: "string-ball strings", which are linearly extended, self-gravitating configurations of string balls obtained in the Horowitz-Polchinski (HP) approach to near-Hagedorn string states. We construct non-uniform HP strings in spatial dimensions and show that, as the inhomogeneity increases, they approach localized HP balls. By examining the thermodynamic properties of the different phases in the canonical and microcanonical ensembles, we find that, for a given mass, the uniform HP string will not evolve into a non-uniform or localized configuration. Building on these results and independent evidence from the evolution of the black string instability with corrections, we propose that string theory slows and eventually halts the pinching evolution at a classically stable stringy neck, with details depending on the dimension . The system then enters a slower phase in which the neck gradually evaporates into radiation. We discuss this scenario as a framework for understanding how string theory resolves the formation of naked singularities
The biodiversity premium
No full textInternational audienceFocusing on biodiversity risks, we perform an empirical asset pricing analysis and document three main results. First, the factor going long on low biodiversity intensity assets and short on high biodiversity intensity ones as well as the factors based on the biodiversity intensity subcomponents (land use, greenhouse gases—GHG, air pollution, and water pollution) have heterogeneous dynamics but are not spanned by the Fama and French (2015) and carbon factors. Second, the biodiversity factor excluding the GHG subcomponent (ex-GHG) commands a positive risk premium on realized returns and a negative one on expected returns in the sector highly exposed to the double materiality of biodiversity risks (i.e., physical and transition risks). Third, we show that the negative premium of both the biodiversity and the ex-GHG biodiversity factors on expected returns has materialized strongly from 2021 onward and that it amplifies with attention to biodiversity issues and risk aversion.<br/
Causal and Stable Superfluid Hydrodynamics
No full textInternational audienceWe investigate the linearized stability and causality properties of relativistic viscous superfluid hydrodynamics. The Landau-Lifshitz-Clark-Putterman formulation for the theory of relativistic viscous superfluids suffers from the same instability and acausality issues as the relativistic Navier-Stokes equation for normal fluids when written in the formulations of Eckart or Landau and Lifshitz. We show that conditions to ensure stability and causality can be satisfied with judicious redefinitions of the hydrodynamic variables. The conditions we obtain hold at non-zero superfluid velocity as well
Study of same-sign W boson scattering and anomalous couplings in events with one tau lepton from pp collisions at = 13 TeV
No full textInternational audienceA first measurement is presented of the cross section for the scattering of same-sign W boson pairs via the detection of a lepton. The data from proton-proton collisions at the center-of-mass energy of 13 TeV were collected by the CMS detector at the LHC, and correspond to an integrated luminosity of 138 fb. Events were selected that contain two jets with large pseudorapidity and large invariant mass, one lepton, one light lepton (e or ), and significant missing transverse momentum. The measured cross section for electroweak same-sign WW scattering is 1.44 times the standard model prediction. In addition, a search is presented for the indirect effects of processes beyond the standard model via the effective field theory framework, in terms of dimension-6 and dimension-8 operators
Learning in Games with progressive hiding
No full textInternational audienceWhen learning to play an imperfect information game, it is often easier to first start with the basic mechanics of the game rules. For example, one can play several example rounds with private cards revealed to all players to better understand the basic actions and their effects. Building on this intuition, this paper introduces {\it progressive hiding}, an algorithm that learns to play imperfect information games by first learning the basic mechanics and then progressively adding information constraints over time. Progressive hiding is inspired by methods from stochastic multistage optimization such as scenario decomposition and progressive hedging. We prove that it enables the adaptation of counterfactual regret minimization to games where perfect recall is not satisfied. Numerical experiments illustrate that progressive hiding can achieve optimal payoff in a benchmark of emergent communication trading game