Universality in Systems with Power-Law Memory and Fractional Dynamics

There are a few different ways to extend regular nonlinear dynamical systems by introducing power-law memory or considering fractional differential/difference equations instead of integer ones. This extension allows the introduction of families of nonlinear dynamical systems converging to regular systems in the case of an integer power-law memory or an integer order of derivatives/differences. The examples considered in this review include the logistic family of maps (converging in the case of the first order difference to the regular logistic map), the universal family of maps, and the standard family of maps (the latter two converging, in the case of the second difference, to the regular universal and standard maps). Correspondingly, the phenomenon of transition to chaos through a period doubling cascade of bifurcations in regular nonlinear systems, known as "universality", can be extended to fractional maps, which are maps with power-/asymptotically power-law memory. The new features of universality, including cascades of bifurcations on single trajectories, which appear in fractional (with memory) nonlinear dynamical systems are the main subject of this review.Comment: 23 pages 7 Figures, to appear Oct 28 201

Impact of remote titration combined with telemonitoring on the optimization of guideline-directed medical therapy for patients with heart failure: internal pilot of a randomized controlled trial

Background: To improve health outcomes in patients with heart failure, guideline-directed medical therapy (GDMT) should be optimized to target doses. However, GDMT remains underutilized, with less than 25% of patients receiving target doses in clinical practice. Telemonitoring could provide reliable and real-time physiological data for clinical decision support to facilitate remote GDMT titration. Objective: This paper aims to present findings from an internal pilot study regarding the effectiveness of remote titration facilitated by telemonitoring. Methods: A 2-arm randomized controlled pilot trial comparing remote titration versus standard care in a heart function clinic was conducted. Patients were randomized to undergo remote medication titration facilitated by data from a smartphone-based telemonitoring system or standard titration performed during clinic visits. Results: A total of 42 patients with new-onset (10/42, 24%) and existing (32/42, 76%) heart failure and a mean age of 55.29 (SD 11.28) years were randomized between January and June 2019. Within 6 months of enrollment, 86% (18/21) of patients in the intervention group achieved optimal doses versus 48% (10/21) of patients in the control group. The median time to dose optimization was 11.0 weeks for the intervention group versus 18.8 weeks for the control group. The number of in-person visits in the intervention group was 54.5% lower than in the control group. Conclusions: The results of this pilot study suggest that remote titration facilitated by telemonitoring has the potential to increase the proportion of patients who achieve optimal GDMT doses, decrease time to dose optimization, and reduce the number of clinic visits. Remote titration may facilitate optimal and efficient titration of patients with heart failure while reducing the burden for patients to attend in-person clinic visits. Trial Registration: ClinicalTrials.gov NCT04205513; https://clinicaltrials.gov/ct2/show/NCT0420551

A Prospective Mixed-Methods Study of Decision-Making on Surgery or Active Surveillance for Low-Risk Papillary Thyroid Cancer

Background: Active surveillance (AS) of small, low-risk papillary thyroid cancers (PTCs) is increasingly being considered. There is limited understanding of why individuals with low-risk PTC may choose AS over traditional surgical management. Methods: We present a mixed-methods analysis of a prospective observational real-life decision-making study regarding the choice of thyroidectomy or AS for management of localized, low-risk PTCs <2 cm in maximum diameter (NCT03271892). Patients were provided standardized medical information and were interviewed after making their decision (which dictated disease management). We evaluated patients' levels of decision-self efficacy (confidence in medical decision-making ability) at the time information was presented and their level of decision satisfaction after finalizing their decision (using standardized questionnaires). We asked patients to explain the reason for their choice and qualitatively analyzed the results. Results: We enrolled 74 women and 26 men of mean age 52.4 years, with a mean PTC size of 11.0 mm (interquartile range 9.0, 14.0 mm). Seventy-one patients (71.0% [95% confidence interval 60.9-79.4%]) chose AS over surgery. Ninety-four percent (94/100) of participants independently made their own disease management choice; the rest shared the decision with their physician. Participants had a high baseline level of decision self-efficacy (mean 94.3, standard deviation 9.6 on a 100-point scale). Almost all (98%, 98/100) participants reported high decision satisfaction. Factors reported by patients as influencing their decision included the following: perceived risk of thyroidectomy or the cancer, family considerations, treatment timing in the context of life circumstances, and trust in health care providers. Conclusions: In this Canadian study, ∼7 out of 10 patients with small, low-risk PTC, who were offered the choice of AS or surgery, chose AS. Personal perceptions about cancer or thyroidectomy, contextual factors, family considerations, and trust in health care providers strongly influenced patients' disease management choices