In this work, we address the problem of finite-time stabilization for a class of bilinear system. We propose a decomposition-based approach in which the nominal system is split into two subsystems, one of which is inherently finite-time stable without control. This allows the stabilization analysis to focus solely on the remaining subsystem. To ensure the well-posedness of the closed-loop system, we establish sufficient conditions on the system and control operators. The stabilization results are then derived using a suitable Lyapunov function and an observation condition. The effectiveness of the proposed approach is demonstrated through examples involving both parabolic and hyperbolic infinite-dimensional systems.
Introduction Infective endocarditis (IE) remains a severe disease with high mortality despite advances in management. Although it predominantly affects male patients, female patients account for about 1-quarter of cases. Sex-specific differences in outcomes and prognostic factors remain insufficiently explored. Methods We conducted a retrospective study including 519 patients ≥16 years hospitalized for definite or possible IE (ESC 2023 criteria) at La Timone Hospital, Marseille, between March 2019 and October 2023. The primary endpoint was 1-year mortality; secondary endpoints included surgical management, valve involvement, and prognostic factors. Results Of the 519 patients, 26% were female patients. One-year mortality was comparable between sexes (27% in female patients vs 23% in male patients, P = .415). Postdischarge mortality was not significantly different between sexes (P = .096). Mitral valve involvement was more frequent in female patients, and aortic involvement predominated in male patients. Independent predictors of mortality included annular complications and lack of surgery. Importantly, sex-specific differences in prognostic factors were observed in this exploratory analysis: in female patients, TAVI and ischemic heart disease were associated with higher mortality; in male patients, right-sided IE and pacemaker presence were predictive. Furthermore, fatal cases in male patients were marked by more in-hospital complications (heart failure, cardiogenic or septic shock, acute renal failure), suggesting distinct mortality pathways. Conclusion Although overall mortality was similar between sexes, male patients and female patients with IE appeared to show different prognostic profiles in this single-center cohort. These preliminary, hypothesis-generating findings suggest that some established risk factors may largely reflect male data, emphasizing the need for larger, multicenter studies to confirm sex-specific determinants and improve individualized management.
The purpose of this note is to determine the plume parameter, Γi, for a canonical fire configuration, namely a pool fire. The evaluation of this parameter, which characterizes the plume nature (forced or lazy), requires knowledge of the vertical velocity and temperature of the gases in the near-field region above the fire source. Order-of-magnitude estimates of these two quantities are obtained by combining two formulations of the convective heat release rate. A numerical application presented for a heptane pool fire indicates a plume parameter greater than unity, which thus suggests a lazy plume behavior. This is a result that is likely to be of interest to researchers who use surrogate buoyant plumes in their laboratory experiments for smoke propagation and control issues.
Motor imagery (MI), the mental simulation of movement without execution, provides a behavioural tool to evaluate sensorimotor representations. However, its characterisation in young children remains debated. This study investigated age-related differences in MI across early primary school years using a multi-task battery.One hundred and eighteen children aged 5–8 years (61 females), spanning the final year of kindergarten (GSM), first grade (CP), second grade (CE1), and third grade (CE2), completed executed and imagined trials of five functional tasks (standing up, typical gait, precision gait, drawing, and cube handling). Psychometric properties of the battery were evaluated. To ensure feasibility, engagement with imagery tasks was verified by comparing executed-imagined consistency in complexity-duration structure (i.e., complex tasks take longer both when executed and when imagined). Age-related differences were evaluated in terms of execution–imagery isochrony and variability across classes.Internal consistency was excellent (α = .91–.98) and test–retest reliability ranged from moderate to excellent (ICC = .68–.92). Engagement increased by age but already exceeded 70 % in the youngest group. Isochrony improved with age for simpler, highly practised tasks (typical gait, standing up), whereas more complex tasks (precision gait, cube handling) showed stable performance across classes. Variability decreased with age, and older children’s performance became increasingly influenced by task complexity demands.Findings demonstrate that mental chronometry can reliably capture MI abilities in children as young as five, revealing both developmental gains and task-specific constraints. These results highlight the feasibility of MI assessment in early childhood, warranting the need for longitudinal neuroimaging approaches to clarify mechanistic insights.
Pressure relaxation is a fundamental mechanism in compressible multiphase flows and heterogeneous materials, where local pressure disequilibria arise from unresolved microscale processes such as wave scattering, pore deformation, and interfacial dynamics. At the macroscopic scale, these phenomena manifest as dissipative volume redistribution mechanisms that progressively drive the system toward mechanical equilibrium. Despite their importance, pressure relaxation closures are commonly introduced through phenomenological source terms whose thermodynamic consistency and physical interpretation remain largely heuristic.This work proposes a variational framework for finite-rate pressure relaxation in compressible multiphase flows based on the theory of Generalized Standard Materials. The relaxation process is formulated as a constitutive evolution law governed by the competition between a stored energy and a convex dissipation pseudo-potential depending on the rates of volume fractions. The resulting evolution equations are obtained from the stationarity conditions of an incremental variational principle, providing a systematic derivation of relaxation closures while ensuring non-negative entropy production and thermodynamic consistency by construction.The framework is developed for both phase-wise and interaction-based dissipation potentials. A central result is that the interfacial pressure emerges naturally as a Lagrange multiplier associated with the saturation constraint on volume fractions, rather than being prescribed through ad hoc averaging or impedance-weighting procedures. This yields a rigorous thermodynamic interpretation of interfacial pressure and clarifies its role in energy exchanges between phases.The variational structure further induces symmetric tangent operators for the constitutive update problem, enabling efficient and robust monolithic Newton solution strategies. The proposed formulation is discretized within a Godunov-type finite-volume framework and applied to representative multiphase flow configurations. The results demonstrate the accuracy, robustness, and thermodynamic consistency of the approach, and highlight its potential as a unified constitutive framework for dissipative processes in compressible multiphase and heterogeneous media.
