Intermittency of Superpositions of Ornstein-Uhlenbeck Type Processes

The phenomenon of intermittency has been widely discussed in physics literature. This paper provides a model of intermittency based on L\'evy driven Ornstein-Uhlenbeck (OU) type processes. Discrete superpositions of these processes can be constructed to incorporate non-Gaussian marginal distributions and long or short range dependence. While the partial sums of finite superpositions of OU type processes obey the central limit theorem, we show that the partial sums of a large class of infinite long range dependent superpositions are intermittent. We discuss the property of intermittency and behavior of the cumulants for the superpositions of OU type processes

The unusual properties of aggregated superpositions of Ornstein-Uhlenbeck type processes

Superpositions of Ornstein-Uhlenbeck type (supOU) processes form a rich class of stationary processes with a flexible dependence structure. The asymptotic behavior of the integrated and partial sum supOU processes can be, however, unusual. Their cumulants and moments turn out to have an unexpected rate of growth. We identify the property of fast growth of moments or cumulants as intermittency

Reliability and construct validity of the Participation in Life Activities Scale for children and adolescents with asthma: an instrument evaluation study

<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to evaluate the reliability and construct validity of the Participation in Life Activities Scale, an instrument designed to measure older school-age child and early adolescent level of involvement in chosen pursuits.</p> <p>Methods</p> <p>A cross-sectional design was used. The convenience sample consisted of 313 school-age children and early adolescents with asthma, ages 9–15 years. The self-report summative scale of interest is a 3-indicator survey. Higher scores are reflective of higher levels of participation. Internal consistency reliability and construct validity for the entire sample and sub groups of the sample were evaluated.</p> <p>Results</p> <p>The instrument was deemed sound for the entire sample as well as sub groups based on sex, race, age, socioeconomic status, and severity of illness. Cronbach's alpha coefficient for internal consistency reliability for the entire sample was .74. Exploratory factor analysis indicated a single component solution (loadings .79–.85) accounting for 66% of the explained variance. Construct validity was established by testing the posed relationship between participation in life activities scores and severity of illness. Confirmatory factor analysis revealed a good fit between the data and specified model, χ²(10, <it>n </it>= 302) = 8.074, <it>p </it>= .62.</p> <p>Conclusion</p> <p>This instrument could be used (a) in clinical settings to diagnose restricted participation in desired activities, guide decision-making about treatment plans to increase participation, and motivate behavioral change in the management of asthma; and (b) in research settings to explore factors influencing and consequences of restricted and unrestricted participation, and as an outcome measure to evaluate the effectiveness of programs designed to foster child and early adolescent management of asthma.</p

Testing an implementation strategy bundle on adoption and sustainability of evidence to optimize physical function in community-dwelling disabled and older adults in a Medicaid waiver: a multi-site pragmatic hybrid type III protocol

Background: In partnership with a state Medicaid home and community-based waiver program, this study tests implementation strategies for adoption and sustainability of an evidence-based intervention to support disabled and older adults who have difficulty with physical function and daily living tasks. A multi-level implementation strategy bundle will be directed at relationship, coalition, and team building; readiness to implement, leadership, and clinician attitude toward evidence assessments; intervention and facilitation training; interdisciplinary coordination; facilitation; and audit and feedback to support practice change. Methods: Knowledge-to-Action model underpins this 2-arm, 3-year pragmatic mixed method randomized hybrid type III trial in 18 waiver program sites in Michigan. Data will be collected on sites, 775 clinicians (registered nurses, occupational therapists, social workers), and 15,000 disabled and older adults. Consolidated Framework for Implementation Research guides examination of site, clinician, and beneficiary characteristics; clinician attitude and self-efficacy; leadership and readiness to implement; and intervention impact on beneficiary outcomes. Sites will be randomized to either usual waiver care with internal facilitation of the bundle of implementation strategies or usual waiver care with both internal and external facilitation of the bundle. Primary outcomes are site-level adoption and sustainability over 12 months, and intervention effects on these outcomes are hypothesized to be mediated by clinicians’ attitude and self-efficacy. At the beneficiary level, by addressing the individual’s capabilities and home environment, the intervention is hypothesized to improve secondary outcomes of activities of daily living, pain, depression, falls, emergency department visits, and hospitalizations. Baseline site readiness and leadership and stages of implementation at 6months will be explored as potential moderators. Linear mixed effects models will be used to test intervention effects on primary outcomes, with bias-correcting analytic strategy in mediation analyses. Generalized linear mixed effects modeling will be employed for the analysis of intervention effects on secondary outcomes. Discussion: Synthesizing findings within and across the sites, we will specify how leadership, readiness for change, and level of facilitation enhance capacity for adoption and sustainability of an evidence-based intervention in an underresourced Medicaid setting that cares for disabled and older adults

Heavy-tailed fractional Pearson diffusions

We define heavy-tailed fractional reciprocal gamma and Fisher-Snedecor diffusions by a nonMarkovian time change in the corresponding Pearson diffusions. Pearson diffusions are governed by the backward Kolmogorov equations with space-varying polynomial coefficients and are widely used in applications. The corresponding fractional reciprocal gamma and Fisher-Snedecor diffusions are governed by the fractional backward Kolmogorov equations and have heavy-tailed marginal distributions in the steady state. We derive the explicit expressions for the transition densities of the fractional reciprocal gamma and Fisher-Snedecor diffusions and strong solutions of the associated Cauchy problems for the fractional backward Kolmogorov equation

Ehrenfest-Brillouin-type correlated continuous time random walk and fractional Jacobi diffusion

Continuous time random walks (CTRWs) have random waiting times between particle jumps. Based on Ehrenfest-Brillouin-type model motivated by economics, we define the correlated CTRW that converge to the fractional Jacobi diffusion Y (E(t)), t ≥ 0, defined as a time change of Jacobi diffusion process Y (t) to the inverse E(t) of the standard stable subordinator. In the CTRW considered in this paper, the jumps are correlated so that in the limit the outer process Y (t) is not a L´evy process but a diffusion process with non-independent increments. The waiting times between jumps are selected from the domain of attraction of a stable law, so that the correlated CTRWs with these waiting times converge to Y (E(t))

Results of a multi-site pragmatic hybrid type 3 cluster randomized trial comparing level of facilitation while implementing an intervention in community-dwelling disabled and older adults in a Medicaid waiver

Background: Evidence-based interventions that optimize physical function for disabled and older adults living in the community who have difficulty with daily living tasks are available. However, uptake has been limited, particularly in resource-constrained (Medicaid) settings. Facilitation may be an effective implementation strategy. This study’s aim was to compare internal facilitation (IF) versus IF and external facilitation (EF) on adoption and sustainability of an intervention in a Medicaid home and community-based waiver. Methods: In a hybrid type 3 trial, waiver sites (N = 18) were randomly assigned to implement the intervention using a bundle of strategies with either IF or IF and EF. Adoption and sustainability were assessed via Stages of Implementation Completion (SIC) for each site. Clinician attitudes toward evidence-based practice and self-efficacy were evaluated among 539 registered nurses, social workers, and occupational therapists. Medicaid beneficiary outcomes of activities of daily living, depression, pain, falls, emergency department visits, and hospitalizations were evaluated in a sample of N = 7030 as reflected by electronic health records data of the Medicaid waiver program. Linear mixed-effects models were used to compare outcomes between trial arms while accounting for cluster-randomized design. Results: The mean SIC scores were 72.22 (standard deviation [SD] = 16.98) in the IF arm (9 sites) and 61.33 (SD = 19.29) in the IF + EF arm (9 sites). The difference was not statistically significant but corresponded to the medium clinically important effect size Cohen’s d = 0.60. Clinician implementation outcomes of attitudes and self-efficacy did not differ by trial arm. Beneficiary depression was reduced significantly in the IF + EF arm compared to the IF arm (p = .04, 95% confidence interval for the difference [0.01, 0.24]). No differences between trial arms were found for other beneficiary outcomes. Conclusions: Level of facilitation did not enhance capacity for adoption and sustainability of an evidence-based intervention in a Medicaid setting that cares for disabled and older adults. Improved beneficiary depression favored use of IF and EF compared to IF alone, and no differences were found for other outcomes. These findings also suggest level of facilitation may not have impacted beneficiary outcomes

The unusual properties of aggregated superpositions of Ornstein-Uhlenback type processes

Superpositions of Ornstein-Uhlenbeck type (supOU) processes form a rich class of stationary processes with a exible dependence structure. The asymptotic behavior of the integrated and partial sum supOU processes can be, however, unusual. Their cumulants and moments turn out to have an unexpected rate of growth. We identify the property of fast growth of moments or cumulants as intermittency. Many proofs are given in a supplemental article [21]

Recruitment and Early Retention of Women with Advanced Breast Cancer in a Complementary and Alternative Medicine Trial

More than 80% of women with breast cancer are now reported to be using complementary and alternative medicine (CAM) therapies during conventional treatment. A randomized clinical trial (RCT) of reflexology with late stage breast cancer patients serves as the data source for this article. The purposes were to investigate: (i) reasons for refusal to participate in a RCT of reflexology; (ii) the differences between those who completed the baseline interview and those who dropped out before baseline; and (iii) the utility of the Palliative Prognostic Score (PPS) as a prognostic screening tool in minimizing early attrition (before baseline) from the trial. Eligible women (N = 400) approached at 12 cancer centers in the Midwest had advanced breast cancer, were on chemotherapy or hormonal therapy, and had a PPS of 11 or less. Comparisons of those who dropped out early (N = 33) to those who stayed in the trial (N = 240) were carried out using Wilcoxon rank, t-, chi-squared and Fisher's exact tests. The reasons of being “too sick” or “overwhelmed” were given by less than 12% of the women who refused to participate. There was a higher early dropout rate among black women compared to other (primarily white) women (P = .01). Cancer recurrence and metastasis, age, and the PPS were not predictive of early retention of women. Specialized techniques may be needed to ensure black women remain in the trial once consented. Women with advanced disease were likely to enter and remain in the trial despite deterioration in health