Search Results (132)

Background/Objectives: Antimicrobial resistance threatens public health globally, and critical access hospitals (CAHs) serving rural communities face structural barriers to implementing antibiotic stewardship programs (ASPs). This study evaluated whether a regional educational intervention could improve antimicrobial stewardship knowledge and implementation among rural healthcare professionals. Methods: A quantitative, quasi-experimental repeated cross-sectional evaluation was conducted following Antibiotic Stewardship conferences in 2023 and 2024. Participants from 38 rural and critical access hospitals completed pre-conference, post-conference, 6-month follow-up, and implementation surveys. Quantitative data were analyzed using descriptive statistics and unpaired chi-square tests, with Fisher’s exact test substituted where expected cell counts were below 5, with significance set at p < 0.05. Results: Seventy healthcare professionals participated across both years. Correct identification of the use of an antibiogram to guide empiric (rather than definitive) therapy improved from 27% pre-conference to 58% post-conference (p = 0.029). Confidence in antibiogram interpretation increased from 67% to 100% post-intervention (p = 0.004, Fisher’s exact) but declined to 50% (5 of 10) at 6-month follow-up. Knowledge of the minimum isolate threshold required to construct an antibiogram improved from 23% (7 of 30) pre-conference to 64% (7 of 11) at 6-month follow-up (p = 0.026, Fisher’s exact). Despite this, prescribing intent for conditions where antibiotics are typically unnecessary showed minimal improvement: recommendations for antibiotic use in middle ear infections decreased from 50% to 36.84%, and for mpox from 20% to 15.79%. All participants reported intent to modify clinical practice; however, time constraints, technology limitations, and lack of resources were consistently cited as primary barriers for implementation across both survey years. Conclusions: A regional educational intervention improved short-term antimicrobial stewardship knowledge and confidence among rural healthcare professionals, but knowledge retention declined over time and structural barriers persisted. Education alone is insufficient; sustained reinforcement and rural-adapted ASP models incorporating protected ASP time, decision-support tools and external partnerships are needed to translate knowledge gains into consistent stewardship practice. Full article

Background/Objective: International recommendations exist for MRI evaluation of sacroiliac joints (SIJs) in adult spondylarthritis (SpA) and other joints in juvenile (J)SpA. However, consensus recommendations for MRI acquisition protocols for SIJs in JSpA are lacking. Our survey gathered information on current imaging practices on SIJ MRI and expert opinions about imaging protocols. Methods: A survey was sent to an international group of pediatric radiologists and rheumatologists. Participants were asked about practices regarding sequences/planes, use of contrast, and preferred sequences/planes for evaluating individual lesions. Results: There were 38 unique survey respondents (North America, n = 19; South America, n = 1; Europe, n = 12; Asia, n = 2; Australia, n = 2; unknown = 2) from 32 institutions with a median of 15 (range 3–32) years of experience. Most (93%) institutions use the 2nd sacral vertebral body posterior cortex to plan coronal oblique sequences; most perform these as non-fat-suppressed T1W and fluid-sensitive sequences for evaluation of damage and inflammation, respectively. Among the 84% of institutions performing small field-of-view imaging, all include a coronal oblique plane, and 78% also do an axial oblique plane. Of all institutions, 22% utilize gradient echo (GRE) sequences. Most respondents (79%) did not consider contrast necessary for evaluating SIJs. Conclusions: Areas of agreement for a consensus MRI protocol for SIJ evaluation in JSpA include using a non-contrast-enhanced protocol and the S2 vertebral body posterior cortex to plan coronal oblique sequences. Further international consensus is required concerning the optimal scan plane to prescribe for axial sequences and the incorporation of an erosion-specific sequence into standard protocols. Full article

The classical Lotka–Volterra predator–prey system is often used in modeling species competition. The two-species nonlinear system is expressed in terms of a single positive coupling parameter $\lambda$. Based on a standard functional transformation, a novel $\lambda$-invariant Hamiltonian yields a system of two partially uncoupled first-order hybrid-function ODEs, albeit with one being linear. An exact single quadrature solution that is valid for any value of $\lambda$ and the system’s energy is derived. In the particular case of $\lambda =1$, the ODE system completely uncouples. One ODE is autonomous. An exact analytic quadrature solution is derived that is predicated on the exact turning-point solutions. It is expressed in terms of the Lambert W function and must be evaluated numerically. Exact time-dependent solutions are presented for each individual species separately. In the case of $\lambda \ne 1$ an accurate practical approximation uncoupling the nonlinear system is proposed and solutions are provided in terms of explicit quadratures together with high-energy asymptotic solutions. An exact analytic expression for the system’s oscillation period that is valid for any value of $\lambda$ and orbital energy is derived in terms of a dimensionless energy function. Full article

Accurately predicting high-energy laser propagation toward fast-moving aerial targets is not straightforward, since the slant range, elevation angle, atmospheric path, accumulated turbulence, and thermal blooming all change along with target motion. Because of this coupled evolution, fixed-path or quasi-static models can hardly describe, in a complete way, the time-varying loss of beam transmission and the weakening of energy concentration. To address this problem, this paper builds on established wave-optics propagation methods to develop a dynamic multi-physics framework for high-speed moving-target engagements. The central idea is to rebuild the propagation environment at every time step according to the instantaneous target position so that the optical path can be linked with height-dependent extinction, refractive-index structure, and absorption profiles; meanwhile, relative motion is represented as an effective transverse sweeping velocity, which helps reduce the accumulation effect of thermal blooming. Based on a unified split-step Fourier method, the model combines Beer–Lambert path attenuation, Kolmogorov-spectrum multilayer phase screens, and thermal-blooming phase modulation, yielding time-resolved indicators such as transmittance, received power, peak irradiance, Strehl ratio, scintillation index, pointing error, and beam-quality factor. Simulation results show that, in a 500 m static horizontal path, the attenuation module reduces to the Beer–Lambert solution, with the maximum relative error kept below ${10}^{-14}$; the turbulence phase-screen implementation is validated against the absolute Kolmogorov prediction. Over the resolved inertial interval, the ensemble-averaged structure function yields a fitted exponent $p_{\mathrm{f}\mathrm{i}\mathrm{t}}=1.671$ (theoretical: $5/3=1.667$) and a relative normalization error of $2.5\mathrm{\%}$, confirming that the generated screens reproduce both the Kolmogorov scaling and the prescribed turbulence strength. For a 1.064 μm, 2 kW Gaussian beam propagating over a 50 s trajectory of about 8 km, when the target speed increases from 0 to 300 m/s, the thermal-blooming-related beam-quality factor decreases from roughly 1.8 to 1.2, which indicates that dynamic geometry, turbulence, attenuation, and thermal blooming need to be considered together when evaluating laser propagation performance. Full article

The Lambert W is a Bernstein function and hence the cumulant function of a positive infinitely divisible law, the Lambert law $L(\Lambda )$. The Lambert law is self-decomposable with a unit rate compound Poisson background driving Lévy process (BDLP) with a certain jump law $L\left(J\right)$. Thus, it satisfies the random perpetuity relation $\Lambda \stackrel{L}{=}U(\Lambda +J)$, where U has the standard uniform law, as well as the relation $\Lambda \stackrel{L}{=}U\mathcal{S}J$, where $\mathcal{S}$ is the stationary-excess operator. If the law of J is unspecified, then these two in-law relations together characterise the law of $\Lambda$. Generalisations are pursued in which the Poisson jump rate a is arbitrary. If $a\ne 1$, the above two conditions determine a family of positive infinitely divisible laws for which the Laplace–Stieltjes transforms satisfy an algebraic trinomial equation investigated by Lambert and Euler. These laws occur as limiting distributions of shot noise processes and continuous-time branching processes. A sequence of n-times self-decomposable positive laws derived from a given subordinator is called a BDLP ladder. The BDLP ladder that includes the Lambert law has cumulant functions which are polynomial forms of the Lambert function. Under moment conditions, general BDLP ladder laws are asymptotically normal or stable. Full article

Semi-empirical models remain among the most widely used tools for analyzing proton exchange membrane fuel cells (PEMFCs) because they provide a practical balance between physical interpretability and computational efficiency. Existing reviews primarily focus on optimization techniques, system-level modeling, or data-driven approaches, with comparatively limited attention to the structural evolution of semi-empirical voltage models and their analytical reformulation. This paper presents a structured review of semi-empirical PEMFC models, tracing their development from classical formulations, including the Larminie–Dicks, Amphlett, and Mann models, to recent reduced-parameter models such as the Perez model and its variants. Emphasis is placed on the transition toward reduced formulations, highlighting their potential advantages in terms of numerical stability, reduced parameter coupling, and suitability for parameter-estimation and control-oriented applications. In addition, analytical reformulation approaches based on the Lambert W function and the g-function are reviewed and discussed, showing how these methods can enable partial analytical inversion of nonlinear model equations and support more systematic numerical solution procedures. A comparative benchmark analysis using Ballard Mark V and BCS 500 W PEMFC datasets is presented based on root mean square error, mean absolute error, voltage-error trends, and parameter-sensitivity analysis. The results show that reduced models can provide competitive accuracy and favorable robustness in the considered cases, while physically detailed models may remain advantageous when a richer physical interpretation is required. The review clarifies the trade-offs among physical fidelity, parameter identifiability, model complexity, and computational practicality, and provides guidance for model selection, parameter estimation, and optimization in PEMFC engineering applications. Full article

Deriving rigorous elastoplastic analytical solutions for shallow tunnels subject to a gravity-induced stress gradient presents significant mathematical challenges. This paper introduces a virtual cylindrical structure model to derive a closed-form elastoplastic solution for tunnel excavation. By evaluating the static equilibrium of infinitesimal elements, the methodology explicitly determines the plastic zone boundary via the Lambert W function and yields the elastoplastic distributions of stress and displacement fields under the Mohr–Coulomb criterion. The reliability of the derivations is verified by degenerating the equations under specific boundary conditions and comparing them with classical Lamé solutions, showing agreement at low friction angles ($\varphi =5°-10°$). A case study of a 14.5 m-diameter shield tunnel in the Yangtze River Delta is conducted to demonstrate its practical application. The analytical results show that the maximum convergence displacement is controlled within 15 mm, and a ground loss rate of 1.82% corresponds to an unloading ratio of 40%. The proposed method provides a theoretical tool for preliminary estimating excavation-induced disturbances in shallow homogeneous strata. Full article

The rotational evolution of pulsars is governed by torque mechanisms whose mathematical structure encodes fundamental symmetries of the underlying physics. We demonstrate that the standard spin-down equation $\dot{f}=-sf-r{f}^3-g{f}^5$ derives from a discrete antisymmetry requirement, namely invariance of the torque under reversal of rotation sense, which restricts the frequency dependence to odd integer powers. We show that physically motivated plasma processes systematically break this symmetry, introducing fractional frequency exponents: viscous Ekman pumping at the crust–superfluid boundary layer ($f^{3/2}$), magnetohydrodynamic turbulent dissipation via Kolmogorov and Sweet–Parker cascades ($f^{10/3}$, $f^{11/3}$), non-linear superfluid vortex dynamics ($f^{5/2}$), and saturated r-mode oscillations ($f^{7-2\beta }$). The central result is an exact analytical resolution of the long-standing Crab pulsar braking index puzzle: the observed $n=2.51\pm 0.01$, which has defied explanation for nearly four decades, emerges naturally from the superposition of magnetic dipole radiation ($\dot{f}\propto f^3$) and boundary layer Ekman pumping ($\dot{f}\propto f^{3/2}$), with analytically derived coefficients yielding a dipole-component surface field $B_p=6.2\times {10}^{12}$ G—higher than the standard $\sqrt{P\dot{P}}$ estimate of $3.8\times {10}^{12}$ G, because that formula conflates dipole and non-dipole torques, but lower than applying the Larmor formula to the full spin-down rate ($7.6\times {10}^{12}$ G), since $32.7\%$ of the total torque is non-radiative boundary-layer dissipation. We develop the Riemann–Liouville fractional calculus formalism for these equations, showing that fractional derivatives break time-translation symmetry through intrinsic memory effects, with solutions expressed in terms of Mittag-Leffler and Fox H-functions that interpolate continuously between exponential (fully symmetric) and power-law (scale-free symmetric) relaxation. Lambert–Tsallis $W_q$ functions with non-extensive parameter q encoding broken statistical symmetry enable equation-of-state-independent inference of neutron star compactness and tidal deformability. Our framework establishes a unified symmetry-based classification of pulsar spin-down mechanisms and predicts frequency-dependent braking indices evolving at rate $\mathrm{d}n/\mathrm{d}t\sim 2\times {10}^{-4}$ yr⁻¹, yielding $\mathrm{\Delta }n\approx 0.01$ over 50 years—testable with current pulsar timing programmes. The formalism provides a coherent theoretical foundation connecting plasma microphysics at the neutron star interior to macroscopic observables in electromagnetic and gravitational wave channels. Full article

This paper develops a teletraffic-based energy-efficiency analysis of QoS-constrained NOMA using an order-statistics framework for underlay secondary-access operation. Throughput is derived from the ordered SIR distribution for an orthogonal reference and for NOMA under minimum-rate requirements. A linear base-station power model is then incorporated to define energy efficiency, including both transmit power and SIC-related processing. For the multiuser case, the analysis shows that QoS constraints impose a structural feasibility limit on the supported number of users, which is also approximated in closed form through the Lambert W function. By coupling this feasibility result with a birth–death teletraffic model, the average energy efficiency is obtained as a function of the offered load. The results show that stricter QoS requirements reduce energy efficiency, while NOMA preserves a wider feasible region than the orthogonal reference in the setting considered. From a symmetry/asymmetry perspective, the orthogonal reference provides a more symmetric access structure, whereas NOMA introduces asymmetry through user ordering, unequal power allocation, and SIC. The resulting framework links ordered-user operation, QoS feasibility, SIC-aware power consumption, and traffic dynamics in the energy-efficiency characterization of underlay secondary access. Full article

Red Amaranth (RA) Azo dye is a persistent pollutant in wastewater and stands as a toxicological risk, which has led to the development of effective methods for its removal and photocatalytic degradation. Therefore, CeO₂ nanoparticles were synthesized by a controlled precipitation method, and Ultraviolet-Visible (UV–Vis) analysis and Tauc plots yielded a band gap of ~3.24 eV. The CeO₂ nanoparticles showed the fluorite cubic phase, and nearly spherical particles with an average size of ~10 nm. Nitrogen physisorption revealed a type IV isotherm with a Brunauer–Emmett–Teller (BET) surface area of 85.27 m²·g⁻¹ and a total pore volume of 0.27 cm³·g⁻¹, indicating a mesoporous structure and high surface accessibility. The chemical behavior showed Ce and O, consistent with phase purity. Photocatalytic performance was evaluated in 20 ppm aqueous solution of RA under 365 nm UV irradiation (LED 100 W), with a temperature of ~20 °C and a 15 min dark adsorption step. Concentration decay was followed at λ_max = 520 nm by Lambert–Beer. The degradation efficiency η and pseudo-first-order kinetic were obtained from ln(C₀/C_t) vs. time. In addition, chemical oxygen demand (COD) tests were performed on RA solution before and after photodegradation, showing a COD reduction of ~85% (from 19.8 to 3 mg O₂·L⁻¹), which corroborates mineralization beyond chromophore bleaching. Under [C₀ = 20 mg·L⁻¹] and [m_cat = 1.0 g·L⁻¹], CeO₂ achieved [RA = 90% at 180 min, k = 0.0125 min⁻¹]. These results demonstrate that CeO₂ is an effective photocatalyst for RA degradation under UV-A irradiation, integrating adsorption, kinetic behavior, and mineralization performance into a coherent structure–property relationship. Full article

The 2x2 Demonstrator, a prototype for the Deep Underground Neutrino Experiment (DUNE) liquid argon (LAr) Near Detector, was exposed to the Neutrinos from the Main Injector (NuMI) neutrino beam at Fermi National Accelerator Laboratory (Fermilab). This detector is a prototype of a new modular design for a liquid argon time-projection chamber (LArTPC), comprising a two-by-two array of four modules, each further segmented into two optically isolated LArTPCs. The 2x2 Demonstrator features a number of pioneering technologies, including a low-profile resistive field shell to establish drift fields, native 3D ionization pixelated imaging, and a high-coverage dielectric light readout system. The 2.4-tonne active mass detector is flanked upstream and downstream by supplemental solid-scintillator tracking planes, repurposed from the MINERvA experiment, which track ionizing particles exiting the argon volume. The antineutrino beam data collected by the detector over a 4.5 day period in 2024 include over 30,000 neutrino interactions in the LAr active volume—the first neutrino interactions reported by a DUNE detector prototype. During its physics-quality run, the 2x2 Demonstrator operated at a nominal drift field of 500 V/cm and maintained good LAr purity, with a stable electron lifetime of approximately 1.25 ms. This paper describes the detector and supporting systems, summarizes the installation and commissioning, and presents the initial validation of collected NuMI beam and off-beam self-triggers. In addition, it highlights observed interactions in the detector volume, including candidate muon antineutrino events. Full article

This study proposes Optimized Skewness and Kurtosis Transformation (OSKT), a novel moment-targeting normality transformation that corrects asymmetry and peakedness in non-normal data. OSKT employs a transformation function derived from the Tukey g–h distribution, incorporating skewness and kurtosis parameters, and is optimized by minimizing a single objective function based on the Anderson–Darling test statistic. The optimization process uses L-BFGS-B to tune the transformation parameters to find the best fit for the standard normal distribution. OSKT ensures a balance between symmetry and tail behavior by minimizing deviations from theoretical normality. It has highly competitive performance compared to the alternative, Box–Cox, Yeo–Johnson transformations, including their robust variants and moment-matching Lambert W method, for normalizing complex distributions. According to our analysis, OSKT also achieves superior normalization for highly non-Gaussian data, successfully transforming highly resistant distributions, including approximately symmetric bimodal datasets, where other methods fail. Full article

High-fidelity 3D reconstruction of human-sized objects typically requires multi-sensor scanning systems that are expensive, complex, and rely on proprietary hardware configurations. Existing low-cost approaches often rely on handheld scanning, which is inherently unstructured and operator-dependent, leading to inconsistent coverage and variable reconstruction quality. This limitation necessitates the need for a controlled, repeatable, and affordable scanning method that can generate high-quality data without requiring multi-sensor hardware or external tracking markers. This study presents a marker-less scanning platform designed for human-scale reconstruction. The system consists of a single structured-light sensor mounted on a vertical linear actuator, synchronised with a motorised turntable that rotates the subject. This constrained kinematic setup ensures a repeatable cylindrical acquisition trajectory. To address the geometric ambiguity often found in vertical translational symmetry (i.e., where distinct elevation steps appear identical), the system employs a sensor-assisted initialisation strategy, where feedback from the rotary encoder and linear drive serves as constraints for the registration pipeline. The captured frames are reconstructed into a complete model through a two-step Iterative Closest Point (ICP) procedure that eliminates the vertical drift and model collapse (often referred to as “telescoping”) common in unconstrained scanning. To evaluate system performance, a modular anthropometric benchmark object representing a human-sized target (1.6 m) was scanned. The reconstructed model was assessed in terms of surface coverage and volumetric fidelity relative to a CAD reference. The results demonstrate high sampling stability, achieving a mean surface density of $0.760{\mathrm{points}/\mathrm{mm}}^2$ on front-facing surfaces. Geometric deviation analysis revealed a mean signed error of −1.54 mm ($\sigma =$ 2.27 mm), corresponding to a relative volumetric error of approximately 0.096% over the full vertical span. These findings confirm that a single-sensor system, when guided by precise kinematics, can mitigate the non-linear bending and drift artefacts of handheld acquisition, providing an accessible yet rigorously accurate alternative to industrial multi-sensor systems. Full article

Two-dimensional (2D) correlation functions are central to understanding structural crossovers in soft-core fluids; however, their asymptotic analysis is hindered by the Hankel-transform kernel, whose asymptotic representation introduces a term that breaks the natural conjugate symmetry of the poles. To address this, we present a symmetric contour integration scheme that restores symmetry at the level of the integration path. By employing quarter-circle contours in the first and fourth quadrants, the method captures conjugate pole pairs simultaneously and evaluates the sine term from the Bessel-function asymptotic without variable transformation or real-part extraction, yielding closed-form analytic expressions for the long-range decay of the density–density correlation function. The approach is demonstrated for a 2D Gaussian-charge one-component plasma under the random phase approximation at intermediate coupling, where the pole analysis provides direct access to the oscillation wavelength and decay length. In the high-density regime, the pole equations simplify to a form amenable to a Lambert W-function approximation, revealing a logarithmic scaling of correlation lengths even at moderate coupling. These findings establish symmetric contour integration as a transparent and versatile framework for pole-resolved asymptotics in 2D liquids. Full article

This study develops an intelligent real-time diagnostic and forecasting model for photovoltaic (PV) stations operating in the rural regions of Kazakhstan. Field measurements show that in Kazakhstan’s rural conditions, daily temperature fluctuations of 18–27 °C reduce PV output by 10–15%, solar irradiance variations of 800–1100 W/m² cause an additional 8–12% deviation, and mineral-rich dust accumulation of 20–120 μm results in 3–5% power loss per 10 μm layer. Using the Beer–Lambert–Bouguer law, thermal degradation coefficients, and inverter droop models, the physical–mathematical behavior of PV degradation was described. The hybrid AI model (LSTM + XGBoost + Random Forest) achieved 89–91% accuracy in 24 h forecasting and 88–93% accuracy in fault detection. Overall, the proposed system reduces energy losses by 10–15% and shortens maintenance time by 18–24%, improving the reliability of rural PV stations in Kazakhstan. Full article