Search Results (825)

This paper presents a computational model of delirium in the Intensive Care Unit (ICU), in which delirium is defined as the endpoint of a self-reinforcing cycle of predictive failure between two bidirectionally coupled agents: the patient and the ICU room environment. Drawing on the active inference framework and the free energy principle, the paper proposes that delirium is not a property of the patient in isolation but a relational phenomenon that emerges when the environment persistently fails to predict the patient’s internal state. This failure triggers a causal feedback mechanism in which desynchronization pressure progressively sharpens the patient’s prior beliefs—implementing precision rigidity in the correct active inference sense: not a brain overwhelmed by noise but a brain locked into a state that incoming observations can no longer update. The model is implemented as a two-agent POMDP in which both agents maintain generative models and continuously attempt to predict each other’s states. The room agent (R)—understood as the environment-side sensing–inference–actuation loop, whether instantiated by clinical staff or by an automated monitoring system—infers the patient (P)’s latent parameters $({\theta }_{\mathrm{cog}},{\theta }_{\mathrm{emo}})$ over time and builds a progressively personalized generative model of the patient. Synchronization is operationalized via two commensurable directional surprisal metrics: $S_{R\to P}=-ln{Q}_R\left(s^{*}\right)$, the room’s surprisal at the patient’s true state, and $S_{P\to R}=-lnP(o_R\mid Q_P)$, the patient’s surprisal at the room’s observations. A systematic ablation study across four model variants shows that room inference is the architectural component necessary to reproduce the synchronization–delirium relationship: when the room infers, the association between synchronization and declared delirium is strong and stable, whereas a non-inferring room collapses to ceiling delirium rates and a weak association. $\theta$ learning and the prior-sharpening feedback do not increase the strength of this association; instead they shape the phenotypic gradient, reducing ceiling effects in vulnerable phenotypes and amplifying the separation between them. The model is presented as a computational hypothesis generator rather than a calibrated clinical predictor, and its implications for ICU design are discussed. Full article

Background/Objectives: Right heart failure remains the leading cause of death in pulmonary hypertension. Early detection of right-sided congestion is crucial but relies largely on clinical signs with limited diagnostic accuracy. We performed a post hoc analysis of the CODOVEIN study to evaluate the diagnostic performance of clinical and non-invasive parameters for predicting elevated right atrial pressure (RAP). Methods: This post hoc analysis included patients from a prospective cross-sectional study who underwent right heart catheterization. Clinical signs, echocardiographic parameters, venous Doppler indices, and NT-proBNP levels were assessed within four hours before catheterization. Patients were stratified according to invasively measured RAP. Diagnostic performances were evaluated using sensitivity, specificity, predictive values, likelihood ratios, and ROC curves. Results: Several clinical and imaging parameters were associated with increasing RAP. Among non-invasive markers, the femoral venous stasis index (FVSI) and inferior vena cava (IVC) collapsibility assessed in transverse view showed the best discriminative ability for detecting RAP > 14 mmHg. FVSI demonstrated the highest positive likelihood ratio (>11) and an excellent negative predictive value (>0.98), outperforming other clinical and echocardiographic markers. Conclusions: In patients with pulmonary hypertension, FVSI provides robust non-invasive identification of right atrial pressure elevation and may complement traditional clinical assessment for the early detection of right-sided congestion. Full article

Obstructive sleep apnea (OSA) constitutes a chronic disorder characterized by recurrent upper airway collapse during sleep. This condition is prevalent among patients with cardiac rhythm disturbances and represents a potent independent risk factor for arrhythmia. Although most studies have concentrated on the association between OSA and atrial fibrillation (AF), numerous investigations have established connections with ventricular and supraventricular arrhythmias. Arrhythmogenesis in OSA represents a complex multifactorial phenomenon. Acute mechanisms involve induction of negative intrathoracic pressure during the effort to breathe, which triggers recurrent episodes of hypoxia, hypercapnia, alterations in carbon dioxide and acid–base equilibrium, as well as surges in sympathetic nervous system activity. Chronic intermittent hypoxia (CIH) and negative thoracic pressure (NTP) induce atrial stretch, chronic structural remodeling, and elevated vagal tone, thereby heightening susceptibility to bradycardic and conduction arrhythmias. Intermediate pathways through which OSA may precipitate arrhythmia encompass heightened systemic inflammation, oxidative stress, a prothrombotic state, and vascular dysfunction. Long-term OSA is linked with atrial enlargement and fibrosis, ventricular hypertrophy, hypertension, and coronary artery disease. These factors predispose to cardiac arrhythmias through the following mechanisms: shortening of the atrial effective refractory period, abnormal automaticity, promotion of slowed and heterogeneous conduction, enhancement of reentrant arrhythmia persistence, and prolongation of the QT interval. In this paper, we aim to present the pathophysiological mechanisms underpinning the association between obstructive sleep apnea and cardiac arrhythmias. Understanding the precise pathophysiological pathways by which obstructive sleep apnea contributes to arrhythmogenesis will enable targeted preventive stratification of patients at risk for cardiovascular events and promote the development of innovative therapies to attenuate OSA-induced arrhythmogenicity. Full article

Amid intensifying extreme climate events, geopolitical conflicts, and sudden trade policy disruptions, the resilience and vulnerability of global staple food trade systems have emerged as pressing governance concerns. This study constructs directed weighted trade networks for wheat, maize, and rice from 2015 to 2024 and evaluates their vulnerability and resilience evolution using a three-dimensional structural resilience framework and underload cascading failure models. The results reveal that all three networks display scale-free and disassortative properties. The wheat network gradually recovered following the Russia–Ukraine conflict, whereas structural imbalance continues to deepen in the maize network, and the rice network faces persistent resilience pressure arising from excessive dependence on core exporters. Cascading failure simulations indicate that targeted attacks on key exporting countries can trigger large-scale network collapse. Introducing cross-crop substitution effects markedly enhances the resilience of individual food trade networks through cross-layer substitution and supplementation; yet under simultaneous attacks, crop substitution effects instead serve as a conduit for cross-layer cascading failure propagation, and even a minimal willingness to substitute can weaken network resilience. Accordingly, this study proposes policy recommendations to strengthen the resilience of the global staple food trade network. Full article

In ultra-cold narrow-window drilling, pipe connection causes flow-path switching as the main circulation is interrupted and bypass circulation is established, breaking the initial relative pressure balance of the whole wellbore and inducing asymmetric transient variations in flow distribution, annular friction, and bottomhole pressure response, thereby increasing the risks of wellbore instability, lost circulation, and kicks. To address the poor pressure-control accuracy, long non-productive time, and inadequate low-temperature adaptability of conventional drilling technologies in the Irkutsk block of Russia, this study developed and field-tested an integrated all-electric managed pressure drilling (MPD) and cold-resistant continuous circulation system (CCS). Existing conventional technologies often suffer from high communication latency and hydraulic freezing in extreme cold environments, leading to uncoordinated pressure compensation. To overcome these limitations, the scientific novelty of this work lies in proposing a transient pressure rebalancing mechanism that effectively suppresses the asymmetric pressure disturbances induced by topological flow path switching. Methodologically, the proposed system was validated through a comprehensive industrial field test. An improved Herschel–Bulkley temperature–pressure coupled model was established to dynamically calculate full wellbore annular pressure loss. Furthermore, a dedicated hardware adapter module utilizing multi-protocol conversion was integrated to achieve a communication delay of less than 8 ms, enabling high frequency coordinated pressure regulation. Field results demonstrate that compared to the delayed responses of conventional systems, the proposed integrated approach successfully maintained a dynamic backpressure tracking error within ±0.069 MPa under extreme conditions of −38 °C and a narrow pressure window of 0.08 g/cm³. The rapid suppression of asymmetric transient responses prevented any lost circulation, kicks, or wellbore collapse. These findings highlight the significant advantages of the integrated system in maintaining pressure field stability, thereby providing a robust and innovative engineering solution for complex well interventions. Full article

Concentrated rear runoff is an important hydraulic factor that promotes slope instability and flow-like transport characteristics in mountainous landslides; however, the deformation–failure process of slopes and their response relationships under different runoff intensities remain unclear. In this study, the Shaziba landslide in Enshi, Hubei Province, China, was selected as the research object. Two-dimensional flume model tests were conducted under four runoff discharge conditions of 7, 15, 27, and 35 mL/s to investigate the effects of runoff intensity on the hydraulic response and failure mode of the slope. The results show that, as the runoff discharge increased from 7 to 35 mL/s, the initial response times of water content, pore water pressure, and earth pressure at the rear edge decreased from 1205, 1488, and 888 s to 160, 248, and 112 s, respectively. Meanwhile, the gully formation time shortened from 6810 to 336 s, and the time of the first evident collapse decreased from 5758 to 650 s. Under low-runoff conditions, slope deformation was dominated by infiltration-induced softening and progressive creep. Under moderate to high runoff conditions, gully incision and gully-wall collapse accelerated slope disintegration, resulting in soil–water mixed transport and enhanced mobility of failed materials. Concentrated rear runoff drives the slope through successive stages of initial deformation, structural disintegration of the slope, flow-like failure, and toe deposition. These findings provide experimental evidence for the identification and prevention of landslides controlled by rear runoff. Full article

Rainfall-induced instability of gravelly silt slopes is strongly affected by infiltration, runoff erosion, pore water pressure evolution, and particle-scale degradation. In this study, laboratory rainfall model tests were conducted on gravelly silt slopes under three extreme rainfall intensities of 80, 120, and 160 mm/h, and an FVM-DEM coupled model was developed to investigate the associated hydromechanical response and failure mechanism. The tested soil was obtained from the Shanghai East Railway Station project, and the 30% gravel content was selected to represent the typical field condition. Pore water pressure gauges and laser displacement sensors were used to monitor the infiltration response and slope deformation. The results show that all three slopes developed shallow instability, but the deformation rate and failure mode changed with rainfall intensity. Under the tested infiltration-excess conditions, the additional rainfall mainly increased surface runoff, toe erosion, and failed mass mobility rather than proportionally increasing the infiltration depth. The numerical results further indicate that failure evolved through equivalent fine matrix mobilization, gravel destabilization, skeleton collapse, and matrix-entrained gravel movement. These findings clarify the progressive instability mechanism of gravelly silt model slopes under extreme rainfall and provide experimental evidence for slope protection under short-duration, high-intensity rainfall. Full article

Background: Hemodynamic failure remains a major determinant of mortality in critical illness, yet its detection is often delayed because conventional monitoring relies predominantly on Eulerian measurements that quantify pressure and flow magnitude without resolving the spatial and temporal organization of circulation. Consequently, clinically significant states of dysfunction may persist despite apparently stable hemodynamic indices. The Geometry of Shock is a conceptual and hypothesis-generating multi-scale framework intended to integrate established cardiovascular physiology with emerging computational approaches for the analysis of circulatory dysfunction. Framework: The proposed framework combines Guytonian venous return physiology and cardiopulmonary interactions with Lagrangian flow topology, geometric representations of circulatory equilibrium, topological data analysis, and physics-constrained inverse modeling. Rather than focusing exclusively on static thresholds of pressure and flow, the framework proposes a structural interpretation of circulation centered on the dynamic organization and coherence of blood transport across cardiovascular domains. Within this paradigm, under-recognized hemodynamic phenotypes—including stressed volume failure, oscillatory shock during spontaneous breathing, macro–microcirculatory decoupling, and pulmonary vascular pressure–flow dissociation—may emerge from disrupted coupling between vascular, cardiac, pulmonary, and microcirculatory systems. These states may represent reversible structural transitions in venous return geometry and cardiopulmonary interaction preceding overt circulatory collapse. Conclusions: By reframing shock as a disorder of circulatory structure and coherence rather than solely a deficit in flow, this framework proposes a mechanistic foundation that may support future approaches aimed at earlier recognition of instability, improved physiological characterization of hemodynamic phenotypes, and future development and prospective validation of physiology-informed computational decision-support strategies in critical care. These concepts remain exploratory and hypothesis-generating rather than clinically validated. Full article

For the low-lying atolls across Pasifika, climate change is neither hoax nor hypothesis but an imminent and lived reality. If theology is always contextual, then this is our context: ecological collapse unfolding in real time, exposing the fragility of some of our most cherished doctrinal frameworks. This paper responds to the growing call to reconsider the nature and function of doctrine under such pressure. Anglican theologian Mike Higton speaks of the “unfinished conversations” and “many voices” addressing the environmental crisis. This study extends that talanoa by bringing the emerging ‘Pasifika Household of God’ tradition into conversation with the Church’s first sustained post-apostolic household theology: Irenaeus of Lyons’ vision of the oikonomia theou. Bringing the Pasifika tradition as developed in the Pasifika Conference of Churches (PCC) declarations into conversation with Irenaeus’ cosmic ktisiology, this paper challenges the dominance of Western doctrinal formulations and calls for repentance through a return to humanity’s true vocation of theosis—divine participation within and as part of what creation itself is becoming in Christ. This vision stands in stark contrast to empire’s apotheosis: the pursuit of false divinity through conquest, neoliberal success, and escapist eschatologies. In the Patristic–Pasifika partnership here proposed, doctrine is not a static catalogue of propositional beliefs but a sacramental indwelling. Doctrine becomes dwelling as depth of tradition meets depth of place. Full article

In the era of big data, the Law of Large Numbers is often treated as an absolute guarantee that increasing sample size (N) leads to a more accurate representation of truth. However, this study challenges this paradigm by demonstrating that in social systems characterized by conformity pressure and systemic bias, the maximization of N paradoxically triggers a structural shift in the selection and filtration of information. Using a sociophysical framework based on statistical mechanics and opinion dynamics, we identify a critical threshold—the “Signal Cliff”—where the diversity of information plummets and minority signals are irreversibly discarded as statistical noise. By executing large-scale simulations up to $N={10}^{10}$ via macro-dynamic approximations, we observe a phase transition from a stochastic phase of informational diversity to a deterministic phase. This collapse of Shannon entropy serves as a mathematical demonstration of “Epistemic Injustice,” where the sheer scale of data acts as a mechanism for silencing minority perspectives. We propose “Informational Health Diagnostics” as a necessary framework for evaluating the integrity of decision-making processes in digital public opinion and democratic elections. This approach provides a vital benchmark for distinguishing between a healthy consensus and a distorted convergence, ensuring robust information judgment in increasingly complex data-driven environments. Full article

The wide application of liquid hydrogen as a key energy carrier is severely limited by the reliability of high-pressure and low-temperature pumps. The traditional research on liquid hydrogen pumps relies on empirical analysis of isolated components, but fails to reveal the fundamental failure mechanism of these pumps. This review argues for a paradigm shift in the understanding and design of liquid hydrogen pumps. We systematically decomposed the failure of the liquid hydrogen pump into a thermodynamic-driven, cross-scale cascading process rather than the failure of isolated components. At the molecular level, the extreme thermal physical properties of liquid hydrogen (ultra-low latent heat and surface tension) can lead to widespread nucleation under slight thermal disturbances. At the mesoscopic scale, the initial perturbation is significantly amplified through the nonlinear dynamics of bubble clusters. This amplification is characterized by intense collapse and strong energy concentration due to the low density and low viscosity of liquid hydrogen. At the component level, this enhanced destructive energy will cause faults similar to phase transitions; namely, the liquid lubrication in the bearings will disappear, the seals will shift from viscous blockage to gas diffusion, and at the same time, the damage caused by low-temperature hydrogen cavitation and corrosion to the materials will also occur simultaneously. At the system level, the strong dynamic coupling among the subsystems has led to a nonlinear performance collapse. This cross-scale failure chain reveals the flaws in the classical cavitation theory, which is based on the assumptions of isothermal and inertia dominance. We have expounded the thermodynamic-dominated cavitation state in liquid hydrogen. This state is quantified by the Σ parameter and governs the multimodal behavior of low-temperature cavitation phenomena. To address this complexity, we have proposed a comprehensive framework that integrates multi-scale collaborative simulation and digital twin, combining molecular dynamics, CFD, system dynamics, and targeted experiments. This review proposes a candidate physical framework for addressing the reliability challenges of liquid hydrogen pumps. It also provides a clear roadmap for the next generation of inherently robust cryogenic fluid machinery, and offers a reference for the design of energy systems under other extreme conditions. Full article

Televised accountability can be understood as a socio-technical urban governance arrangement in which media exposure, evidentiary inputs, staged interaction, and bureaucratic response are tied together in a structured oversight process. Drawing on Nanning’s long-running “Commitment to the People—TV Accountability” program, the analysis covers 73 episodes broadcast between 2014 and 2023, including 327 issue chains and 3675 official responses. Rather than collapsing episodes into aggregate cases, the design preserves issue chains and response sequence. Pre-response pressure is measured through factual specificity, emotional intensity, accountability directness, and evidence type, while official outputs are coded as acknowledgement, deflection, generic commitment, and specific commitment. Row-level logit models indicate that emotional intensity is associated with a broader immediate visible response: higher odds of acknowledgement, deflection, and generic commitment, but lower odds of specific commitment. Accountability directness is associated with higher odds of acknowledgement and deflection. Non-clip evidence is associated with specific commitment, whereas negative exposure clips are associated with lower odds of generic commitment. Terminal unit-chain models and sequence analyses further show that visible concession emerges early, whereas checkable commitment appears later and in fewer chains. Rather than serving as a simple transparency device, televised oversight operates here as a systemic accountability interface. It tends to channel official response toward low-cost, publicly legible adjustment while making high-cost commitment more selective, evidence-dependent, and stage-dependent. The findings speak to ongoing discussion of socio-technical governance, smart-city governance, and public-value production in data-mediated urban accountability settings. Full article

Soft robots have attracted extensive attention owing to their high flexibility. Inflatable membrane tubes offer lightweight and safe environmental interaction, and external shaping actuators have further expanded their applicability. However, modeling such rigid-flexible gas coupled systems remains challenging due to the internal pressure, external loads, and complex deformations including bending, indentation, and wrinkling. To address curvature variation caused by tube deformation hysteresis, this study presents a static model based on virtual work and a segmented approach for inflatable robots. In the actuator unit, the irregular curvature variation and centerline deviation are quantified. In the cantilever unit, the effective bending moment, as well as the wrinkling and failure criteria are derived. The post-buckling deflection equation characterizes the abrupt curvature variation at the tube root caused by the local wrinkling and collapse. A multi-sensor experimental platform is conducted. The experimental results show that the proposed models achieve superior performance in static parameter identification and kinematic prediction. The bending torque error is below 7%, and the tip position error is less than 5% within the bending angle range of 0° to 100°, which confirm that the proposed models accurately predict the coupled deformation and provide a theoretical basis for the precise control of rigid–flexible gas coupled systems. Full article

Expansive soils pose significant challenges in geotechnical engineering due to their volume changes with moisture variations. A critical distinction exists between a soil’s inherent potential to swell or shrink (governed by intrinsic parameters such as clay content, plasticity index, and activity index) and its actual behaviour under specific site conditions (governed by state parameters like porosity and water content). This paper critically evaluates the reliability of widely used single-index and multi-index classification methods against direct oedometer measurements of swelling pressure. Analysis of nearly 600 tests on natural active clays from four different sites in Romania reveals that, for these soils and site conditions, no single intrinsic parameter—nor any simple pair of parameters—correlates reliably with swelling pressure, demonstrating that these indices merely indicate potential, not actual, behaviour. In contrast, state parameters provide more meaningful insights. Drawing on parallels with collapsible soil mechanics, the study introduces the concept of “saturation-independent pressure” (si_p), the stress level beyond which saturated and natural-moisture soil behaviours converge. Furthermore, a practical calculation method is proposed for estimating both foundation heave (upon saturation) and shrinkage (upon drying), based on double oedometer compressibility curves. Notably, a strong correlation (R² = 0.79–0.86) is demonstrated between swelling pressure and the specific swelling strain measured under an initial load of 12.5 kPa, offering a rapid and inexpensive screening tool for identifying potentially problematic active clays. Full article

Traumatic injuries often result in nerve tissue damage and functional deficits due to limited regeneration. Silk fibroin, a biopolymer with inherent biocompatibility and tunable properties, is a promising material for 3D-bioprinted neural tissue scaffolds. This review highlights recent advancements in silk-derived composite scaffolds, often incorporating additional materials like collagen or conductive polymers to enhance their performance. This review examines how material composition, scaffold architecture, and fabrication strategy influence biological response and functional recovery. This comprehensive review follows PRISMA guidelines and uses comprehensive searches of PubMed, MEDLINE, Embase, Web of Science, Cochrane Central, and ClinicalTrials.gov for studies published through 2025. Studies were screened for eligibility based on substance type, mechanical properties, production methods, and outcomes. Findings were synthesized qualitatively. Twelve studies were included, comprising rat (50%), canine (8.3%), and in vitro (41.7%) models. Analysis reveals that silk fibroin acts as a highly adaptable mechanical backbone. It can consistently integrate with bioactive additives (collagen, dECM) or conductive polymers (Polypyrrole, MXene) to meet specific therapeutic demands. For spinal cord injuries, composites reached a compressive modulus capable of resisting physiological pressures and preventing scaffold collapse. In soft tissue applications, silk–hydrogel blends provided localized release of exosomes and small molecules during the acute injury phase, reducing neuroinflammatory markers. Additionally, adding conductive materials allowed the scaffolds to bridge electrical gaps and promote Schwann cell proliferation and neuronal differentiation. Furthermore, 3D bioprinting enabled the creation of defined microchannels that replicate native fascicular architecture. In vivo outcomes consistently showed superior axonal regeneration, myelination, and synaptic reconnection compared to controls, correlating with significant improvements in electrophysiological and motor function. This review highlights the clinical potential of silk fibroin-based 3D-printed biomaterials for nerve regeneration, including neural repair and neural tissue engineering. More recent studies place greater emphasis on integrating mechanical, architectural, and biological considerations into scaffold design, resulting in increasingly multifunctional scaffold systems. Despite promising efficacy, the heterogeneity of fabrication methods and the predominance of rodent models highlight the need for standardized protocols and evaluations in relevant models to facilitate clinical translation. Full article