The impact of memory effect on space fractional strong quantum couplers with tunable decay behavior and its numerical simulation.

The nontrivial behavior of wave packets in the space fractional coupled nonlinear Schrödinger equation has received considerable theoretical attention. The difficulty comes from the fact that the Riesz fractional derivative is inherently a prehistorical operator. In contrast, nonlinear Schrödinger equation with both time and space nonlocal operators, which is the cornerstone in the modeling of a new type of fractional quantum couplers, is still in high demand of attention. This paper is devoted to numerically study the propagation of solitons through a new type of quantum couplers which can be called time-space fractional quantum couplers. The numerical methodology is based on the finite-difference/Galerkin Legendre spectral method with an easy to implement numerical algorithm. The time-fractional derivative is considered to describe the decay behavior and the nonlocal memory of the model. We conduct numerical simulations to observe the performance of the tunable decay and the sharpness behavior of the time-space fractional strongly coupled nonlinear Schrödinger model as well as the performance of the numerical algorithm. Numerical simulations show that the time and space fractional-order operators control the decay behavior or the memory and the sharpness of the interface and undergo a seamless transition of the fractional-order parameters.

Gait and balance assessments as early indicators of frailty in patients with known peripheral artery disease.

BACKGROUND: Peripheral artery disease is associated with increased morbidity and mortality, and frailty syndrome may mediate the risk of these adverse health outcomes to predict intervention results. The aim of this study was to determine the association between motor performance impairments based on in-clinic gait and balance measurements with frailty at intermediate stages (pre-frailty) in peripheral artery disease patients. METHODS: Seventeen participants with peripheral artery disease (≥ 55 years) were recruited and frailty assessed using Fried criteria. Gait and balance were quantified using wearable sensor technologies in the clinical setting. Between-group differences in frailty were assessed using analysis of variance, and independent associations between gait and balance parameters with frailty were determined using logistic regression models. FINDINGS: Based on Fried index nine (53%), participants were pre-frail and eight (47%) were non-frail. Although no between-group differences in demographics or clinical parameters was observed, gait parameters were worse among pre-frail compared to non-frail participants. The highest effect sizes for between-group differences were observed in double support during habitual normal walking (effect size=1.86, p<0.01), speed variability during dual-task (effect size=1.26, p=0.03), and trunk sway during fast walking (effect size=1.43, p=0.02). No significant difference was observed in balance parameters (p>0.07). The regression model using gait parameters demonstrated a high sensitivity and specificity in predicting pre-frailty. INTERPRETATION: A short 25-step sensor-based in-clinic overground gait test objectively identified pre-frailty independent of age. Double support was the most sensitive parameter in identifying pre-frail aging adults.