Search Results (557)

Why do the laws represented by the Standard Model and general relativity have their observed forms, and why do their particular symmetry groups and numerical inputs occur? The reconstruction program proposes that these structures arise from a premetric selection layer logically prior to dynamical evolution. This article develops the laws side of that program as a conditional physical reconstruction framework with a theorem-level mathematical core. It is neither a replacement for established post-read-out physics nor a completed theory of quantum gravity. The Indefinite Reconstruction Stability Principle (IRSP) is formulated as an existence condition: once an observable quotient and a class of admissible continuations have been declared, a candidate physical identity cannot depend on an unread representative or on an arbitrary terminal refinement. A structure that fails this requirement may be an intermediate mathematical configuration, but it is not a reconstruction-independent physical identity. This persistence is not temporal immortality: unstable particles and other transient systems remain admissible when their identities and changes are unambiguously readable. An exact descent theorem formalizes representative independence. A single neutral parent, understood as a common premetric archetype rather than an additional particle, then organizes the conditional read-out bridges. Primitive complement readability, compact scalar return, and smooth holonomy yield codimension-two loop structure and a local $\mathrm{U}\left(1\right)$ connection. A continuum stability implementation of IRSP forces real-root hyperbolicity, while a separate full-dimensional reciprocal-response bridge supplies a nondegenerate quadratic principal form and hence Lorentzian signature with one temporal direction. Conformal descent of the reconstructed curvature two-form independently fixes the total dimension to four. On the selected $(3+1)$-dimensional platform, gauge invariance and nativeness yield a source-free Abelian Maxwell law, while a readable metric scale yields Einstein–Hilbert dynamics at leading order. A separate conditional $3+2$ internal read-out selects $S\left(\mathrm{U}\right(3)\times \mathrm{U}(2\left)\right)$, equivalently, the Standard Model gauge group with maximal ${\mathbb{Z}}_6$ quotient. These results are conditional on explicitly audited bridges. Reconstruction may consequently offer quantum-gravity programs, including string theory, an additional persistence-and-read-out filter on candidate microscopic phases or vacua; applying that filter to solve the landscape problem remains an open program rather than a result established here. Full article

In scattering and tunnelling-to-continuum problems, the regular and irregular solution pairs to the one-particle radial Schrödinger equation follow various amplitude and phase difference conventions at infinity. The Milne transformation of the Schrödinger equation (a.k.a. the Phase-Amplitude Method) leads to a solution pair whose form inherently complies with scattering theory’s requirements of common amplitude and phase difference of $\pi /2$ at the $r\to \mathrm{\infty }$ limit. On occasion, applications favoured the adoption of the reverse phase convention. In this work we present a formal framework that permits switching of the regular/irregular solution pairs between representations. To showcase the formalism, two exemplar potential curves are investigated: a repulsive Coulomb barrier and the Coulomb-Stark potential, the latter corresponding to the hydrogen atom in the presence of a static homogeneous electric field. Analysis of the results, assessment of the methodology and a discussion of possible extensions are also included. Ultimately, this work shows that it is the regular solution that acts as the thread that binds together the different representations. Full article

“Polymer quantum mechanics” is the name given to a quantization scheme inspired by loop quantum gravity in which the configuration space of the theory is chosen to have a discrete topology. Polymer quantization yields a representation of the canonical commutation relations that is genuinely distinct from the conventional “Schrödinger” representation. In this paper, we summarize the main features of polymer quantum mechanics and investigate in detail the polymer quantization of systems with configuration spaces that are classically compact. We show explicitly how using the standard construction of polymer states leads to a Hilbert space of states defined on a finite graph of points. By way of example, we find the exact energy eigenvalues and eigenfunctions for a particle on a ring and a particle in a box defined on such lattices, and discuss similarities and differences from standard Schrödinger quantum mechanics. We also explore the continuum limit of states in these systems, and demonstrate in detail how the exact eigenfunctions in the position representation approach their continuum counterparts. Full article

The widespread penetration of generative artificial intelligence is reshaping adolescents’ social ecosystems and emotional experiences, while challenging the interpretive boundaries of traditional connectedness theories. Following the logical path of “connotation reconstruction–extension transformation–concept construction”, this study integrates the ethics of care and neo-ecological theory to systematically construct a theoretical framework of artificial intelligence connectedness. First, tracing theories across philosophy, sociology, and psychology, this research reconstructs the core connotation of connectedness rooted in the ethics of care, proposes the continuum hypothesis of caring relationships, and clarifies AI’s unique position on this continuum. Second, from the neo-ecological perspective, this paper sorts out the extended structure of connectedness and demonstrates the ecological shifts brought by the rise of virtual microsystems and the entry of AI actors. On this basis, the study formally defines artificial intelligence connectedness and establishes its three-dimensional structure: demand identification, two-way behavioral engagement, and responsive confirmation. Through systematic comparison with adjacent concepts, this paper identifies its uniqueness and positions it as a specific subtype of connectedness for the digital era. It defines it as a perceived bond that is both psychologically real and ethically asymmetric, carrying asymmetric risks under particular usage conditions and design logics. Finally, this paper builds a dual interpretive framework integrating traditional connectedness and artificial intelligence connectedness, verifies its incremental validity and unique predictive power, and puts forward falsifiable research propositions. This study expands the boundary of connectedness theory and provides an integrated analytical framework for parsing the complex mental health mechanisms of adolescents in the digital age. However, it should be noted that the artificial intelligence connectedness proposed in this study is currently a theoretical construct; its scientific validity and applicability remain to be verified through the development of standardized measurement tools and systematic empirical research. Full article

Angle-resolved photoemission spectroscopy (ARPES) clearly resolves surface-localized (SL) states, yet conventional density functional theory (DFT) band structures from slab calculations do not readily distinguish weakly confined SL states on surfaces such as Al(001), as traditional layer-threshold criteria fail for surfaces with long surface-state decay lengths. We establish a dual-criterion scheme using the surface ratio R and the localization integral L weighted by the inelastic mean free path (IMFP) to quantitatively distinguish SL states: R quantifies the surface-projected charge fraction, while L incorporates the photoelectron IMFP to mimic ARPES surface sensitivity, both evaluated within a fully converged 81-layer Al(001) slab that eliminates artificial inter-surface coupling. Band structures color-coded by R and L intuitively highlight SL states as bright yellow-white bands against red bulk backgrounds. Our calculations show that continuum SL features arise from multi-band hybridization (sharp surface resonances). Notably, R and L alone cannot separate absolute surface states from resonances. All DFT calculations were performed using the PBEsol exchange-correlation functional within the GGA framework, the PAW formalism, and an 81-layer Al(001) slab model. This work reveals the electronic nature of surface features on Al(001) and provides a quantitative SL-state identification tool that is conceptually transferable to other crystalline surfaces. Full article

Frailty syndrome and Alzheimer’s disease are prevalent conditions in the elderly that are associated with aging, decreased quality of life, and a significant healthcare burden. Evidence for a relationship between physical frailty and neurodegenerative decline is accumulating. This study analyzed two independent datasets, a frailty dataset based on gait and mobility parameters and an AD dataset with clinical, functional and lifestyle variables, in order to evaluate and compare their classification performance using machine learning. Features were optimized using dimensionality reduction techniques to keep predictors of clinical significance and hyperparameter optimized Random Forest models were built to develop the best model. Evaluation was performed with Accuracy, F1-score, Matthews Correlation Coefficient and Area Under the Curve. The results showed that the models constructed on the whole AD dataset achieved maximum predictive power with an accuracy of 0.946, which was slightly increased to an accuracy of 0.948 after the selection of significant features. Diagnostic models based on frailty were able to demonstrate an ACC predictive capacity of 0.6418, and in terms of feature selection, improvements appeared in all indicators. Regarding the features derived from Alzheimer’s disease associated with geriatric frailty, they managed to surpass the ACC frailty features of 0.741 alone, suggesting some intercalation mechanisms between neurodegeneration and physical vulnerability. These findings show that machine learning algorithms accompanied by feature selection improve clinical discrimination and prediction of frailty and neurodegenerative disorders, which offers a promising aspect for geriatric assessment. The frailty models analyzed demonstrated an ACC predictive capacity of 0.6418, even though feature selection improved all indicators. Alzheimer’s disease-derived features associated with frailty outperformed features in the frailty dataset with an ACC of 0.741, suggesting the mechanism of overlap between neurodegeneration and physical vulnerability. These results support the theory of a motor-cognitive aging continuum, indicating that algorithmic machine learning techniques coupled with feature selection mainly provide computational validation for the biological intersection of neurodegeneration and physical frailty, rather than forming an independent predictive clinical model. Using these algorithms the study highlights shared pathophysiological mechanisms, providing a significant insight into systemic geriatric deterioration. Full article

The rheological behaviour of complex fluids such as blood and polymer melts is governed by viscosities that are inherently subject to epistemic uncertainty arising from incomplete knowledge of evolving small scales rather than intrinsic randomness. Classical continuum models assume precisely known viscosity functions, an assumption that is physically unjustifiable in such systems, while existing fuzzy approaches have failed to integrate rigorously with the full conservation laws of continuum mechanics. To address this gap, we introduce Fuzzy–Viscous Fluid Dynamics (FVFD), a novel framework in which dynamic viscosity is governed by Dynamic Interval-Valued Intuitionistic Fuzzy Sets (DIVIFS), with membership functions grounded in Coleman–Gurtin internal-variable thermodynamics and evolution equations derived from a Lyapunov dissipation postulate. Employing the parabolic comparison principle together with Galerkin–Leray–Hopf theory, we establish that intuitionistic ordering constraints are preserved over time and prove the existence of global weak solutions to the coupled fuzzy Navier–Stokes equations (FNSEs). An exact analytical solution for fuzzy Couette flow is derived, recovering the classical Newtonian limit and shown, via a structural argument, to be non-linear precisely because and only because FVFD departs from the purely local generalised-Newtonian closure shared by the Power-law, Carreau–Yasuda, and Cross models. Three governing dimensionless parameters, the Reynolds number ($Re$), Damköhler number ($Da$), and fuzzy number ($Fz$), are identified and justified to characterise distinct flow regimes. This framework provides a rigorous, physically grounded alternative to stochastic and data-driven methods for explicitly tracking epistemic uncertainty through interval-valued hesitancy parameters, enabling more accurate modelling of complex fluids whose internal aggregation states remain inaccessible to direct observation. Full article

National parks in densely populated regions face growing pressure to shift from boundary-based protection toward cross-boundary landscape governance, yet connectivity between wildlands within and outside the national park remains understudied. China’s large population and marked spatial variation in anthropogenic pressure make it a particularly informative setting for investigating this issue. We developed a rewilding-oriented framework for wildland network modeling, applied to Baishanzu National Park and its surrounding counties in China. By integrating Boolean overlay, wilderness continuum analysis, and circuit theory, we systematically delineated wilderness patches, corridors, and pinch points. We identified 143 wilderness patches covering 1102.79 km² (14.06% of the study area), dominated by small fragments indicative of severe landscape fragmentation. High current-density zones are concentrated along continuous montane forest belts, valley-ridge transition zones, and narrow inter-patch passages. Twenty-six pinch points were identified, primarily within Baishanzu National Park, southeastern Jingning County, and the northern Yunhe–Longquan interface, alongside 15 internal corridors within the park. Rewilding strategies for montane national parks in human-dominated landscapes may benefit from extending beyond boundaries. Cross-boundary wildland network modeling offers a methodological reference for corridor planning and rewilding practice globally. Full article

Background/Objectives: Boronic acid-based proteasome inhibitors (BABPIs) including Bortezomib, Ixazomib, and Delanzomib are clinically relevant anticancer agents whose mechanism of action depends on direct interaction between the boronic acid warhead and the threonine residue at the first position (Thr1), leading to the formation of covalent tetrahedral complex. Although the formation of this complex is well studied, the subsequent behavior of the boronic acid warhead, particularly the possible formation of monoanionic boronate species through deprotonation of one of the two boronic hydroxyl groups, remains unexplored. Therefore, the present study addresses whether the formation of Thr1-OH and a monoanionic boronate species is thermodynamically favorable and which of the two hydroxyl groups is more favorable for deprotonation. Methods: Density Functional Theory (DFT) calculations at the B3LYP/6-311+G(d,p) level, combined with the Polarizable Continuum Model (PCM), were used to study two competing deprotonation pathways for the inhibitors and for a simplified warhead model. To mimic the proteasome environment, reactions were modeled in different polar media—diethyl ether (ε = 4), methanol (ε = 33), and water (ε = 78). Results: Our DFT calculations confirmed that the covalent tetrahedral complex could convert into Thr1-OH and a monoanionic boronate species, representing the deprotonation of one of the boronic hydroxyl groups. Deprotonation via pathway 1 is more favorable than deprotonation via pathway 2 for all inhibitors, especially in polar solvents. Bortezomib demonstrated a strong preference for -OH₁ deprotonation with ∆∆G ≈ −7 kcal·mol⁻¹. In contrast, Ixazomib, Delanzomib, and the simplified warhead model showed smaller ∆∆G values (≈−2 kcal·mol⁻¹), within the method’s uncertainty (±2 kcal·mol⁻¹), suggesting both deprotonation modes under physiological conditions. Conclusions: These results provide comparative thermodynamic insight into the deprotonation behavior of BABPIs, suggesting that the two hydroxyl groups are not equivalent during deprotonation. This finding offers a physicochemical framework that may support the rational design of next-generation BABPIs. Full article

Many bargaining problems allocate control over heterogeneous issues rather than a single scalar surplus. This paper studies a two-player game-theoretic Nash bargaining problem over a continuum of issues with stochastic valuation fields. Taking the classical maximum Nash welfare cutoff allocation as a benchmark, we characterize the selected agreement as an endogenous excursion set of the log-relative valuation field. We then study its economic geometry: stationarity and ergodicity yield deterministic many-issue payoff limits, a finite-domain perturbation formula separates local shocks from global cutoff feedback, Kac–Rice methods describe boundary intensity, and a perimeter penalty for fragmented contracts turns the bargain into a finite perimeter variational problem. At regular boundary points, the complexity-penalized bargain satisfies a curvature-adjusted bargaining condition. The analysis connects cooperative game theory, Nash bargaining, fair division, random field geometry, and contract complexity. Full article

We develop a framework in which quantum field equations are reconstructed from a multi-branch Hamilton–Jacobi structure supplemented by density functionals on configuration space. Each branch is defined by a solution of a functional Hamilton–Jacobi equation, while the associated density encodes measure-theoretic and dynamical information. Under suitable analytical assumptions, we show that the superposition of these branchwise contributions yields a wave functional satisfying the functional Schrödinger equation. The construction is established in a mathematically controlled setting, including finite-dimensional regularizations and a continuum limit under appropriate convergence hypotheses. Explicit examples demonstrate the exact reconstruction of both free and interacting scalar quantum field equations. Extensions to fermionic and gauge fields are outlined, highlighting the role of graded structures and constraints. Beyond the reconstruction result, the framework provides a structural reinterpretation of quantum theory. Classical dynamics is encoded in the space of Hamilton–Jacobi solutions, while quantum phenomena arise from the coherent superposition of these classical configurations through density and phase. From a geometric viewpoint, the construction is naturally related to multisymplectic structures and admits a cohomological interpretation. This approach establishes a direct bridge between classical variational principles and quantum field theory, offering a unified perspective on the emergence of quantum behavior from structured ensembles of classical configurations. Full article

Dry-connected prefabricated composite walls have been increasingly used in steel structures owing to the development of building industrialization and the demand for rapid and efficient construction. However, the respective influences of dry-connection configuration and wall panel material on the seismic response of prefabricated composite walls require further clarification. To address this issue, full-scale quasi-static tests, continuum damage mechanics (CDM) analysis, and finite element simulations were conducted. Six specimens were tested under low-cycle reversed loading. The influence of connection type was evaluated by comparing MRC walls with U-type and Z-type connections, whereas the influence of wall panel material was evaluated by comparing MRC and SFC walls under U-type connections. For the tested MRC walls, the deformation capacity of the connections strongly influenced the failure mode. The U-type rigid connections provided limited deformation buffering, resulting in stress concentration at the wall ends, initial cracking at displacements of 8–10 mm, rapid crack propagation, and semi-brittle failure. In contrast, the Z-type flexible connections released deformation demand through the slip and rotation mechanisms of the slotted holes. The maximum tested displacements of the Z-type specimens were approximately 2.58–2.78 times the ultimate displacements of the corresponding U-type specimens. The Z-type specimens maintained stable load-carrying behavior with limited panel damage throughout the tested displacement range. Furthermore, a restoring-force calculation method was established based on CDM theory, and the predicted peak loads were generally consistent with the experimental results. This study identifies the load-transfer, deformation, and energy-dissipation characteristics of the tested connection–panel configurations and provides comparative evidence for the further development of prefabricated composite wall systems. Full article

To characterize the cross-scale coupling between macroscopic deformation and microscopic rough-surface contact in metal O-rings, this study proposes a macro–micro contact analysis and leakage flow regime identification method for metal O-ring sealing interfaces. Finite element analysis was employed at the macroscopic scale to obtain the sealing contact width and pressure distribution, while microscopic rough-surface morphology was characterized using fractal theory. Based on asperity contact analysis, the equivalent leakage channel height was determined, and the Knudsen number (Kn) was introduced to identify the fluid flow regime within micro-gaps. The results show that the O-ring cross-section flattens into an elliptical shape under compression, while the contact pressure exhibits a saddle-shaped distribution, and micro-gap leakage channels remain present. As the compression ratio increased from 5% to 25%, the sealing contact width and contact pressure increased, whereas the leakage gap height decreased significantly, resulting in an increase in the Kn values from 0.00176 to 0.045, 0.07, 0.155, and 2.78. Consequently, the flow regime evolved from continuum flow through the transition regime to molecular flow. The findings reveal the cross-scale coupling mechanism between macro–micro contact behavior and leakage flow regime evolution, providing practical guidance for determining the preload level and selecting appropriate leakage models in the engineering design of metal O-ring seals. Full article

Background: Although cervical cancer is preventable, Latinas are twice as likely to receive a late diagnosis compared with non-Hispanic Whites (NHW). We currently know very little about the experiences of cervical cancer among middle- to older-age Latinas in the U.S. This study aimed to document Latina cervical cancer survivors’ journeys with an emphasis on improving the cervical cancer system of care to address inequities among a rapidly aging Latina population. Methods: We interviewed participants aged ≥ 40 years with a diagnosis of cervical cancer of three months or greater who identify as Latina. Recruitment was multi-pronged, including electronic healthcare records search, community tabling events, and snowball sampling. We conducted a qualitative study using the Database of Individual Patient Experiences (DIPEx) methodology and identified themes using grounded theory constructivist analysis. Results: A total of 20 Latinas (43 to 85 years old) participated, including 16 Spanish-language interviews. We identified three themes: formative experiences driving screening and prevention behaviors, provider communication that was suboptimal throughout the cancer continuum, and survivorship impacts including isolation and stigma with implications for the next generation. Conclusions: A central takeaway was the pervasiveness of Latinas’ feelings of shame, lack of communication, and isolation. Healthcare systems must improve culturally responsive communication, survivorship support, and screening equity for aging Latina populations. Abuelas, tias, and/or primas (grandmothers, aunts, and cousins) could play a critical role in raising awareness and increasing timely and early screening among the wider Latina population. Full article

The continuum limit theory of dislocations in crystals predicts divergences in the elastic energy at crystal geometry-dependent limiting velocities $v_L$. The $v_L$ separate subsonic, transonic, and supersonic dislocation glide regimes, and are therefore important for material strength models at high strain rates. Although it is known how to calculate these limiting velocities, there is one special case—edge dislocations with reflection symmetry, but non-vanishing elastic constants $c_{16}^{\prime }$ or $c_{26}^{\prime }$—where previous methods have been notoriously slow. In this paper, we address this deficiency by deriving a computationally efficient method for determining the $v_L$ of edge dislocations with reflection symmetry that is two orders of magnitude faster than the previous method. Full article