Orthonormal Polynomials on the Unit Circle and Spatially Discrete Painlev\'e II Equation

We consider the polynomials $\phi_n(z)= \kappa_n (z^n+ b_{n-1} z^{n-1}+ >...)$ orthonormal with respect to the weight $\exp(\sqrt{\lambda} (z+ 1/z)) dz/2 \pi i z$ on the unit circle in the complex plane. The leading coefficient $\kappa_n$ is found to satisfy a difference-differential (spatially discrete) equation which is further proved to approach a third order differential equation by double scaling. The third order differential equation is equivalent to the Painlev\'e II equation. The leading coefficient and second leading coefficient of $\phi_n(z)$ can be expressed asymptotically in terms of the Painlev\'e II function.Comment: 16 page

Strategies for Monitoring Multiuse Trail Networks: Implications for Practice

Many municipalities, park districts, and nonprofit organizations have begun monitoring nonmotorized traffic on multiuse trails as the need for information about the use of facilities has grown and relatively low-cost sensors for automated monitoring have become available. As they have gained experience, they have begun to move from site-specific monitoring on individual trails to a more comprehensive monitoring of trail networks. This case study review compares strategies developed by 10 organizations for monitoring traffic on multiuse trails, including local, multicounty, statewide, and multistate trail networks. The focus is on approaches to the design of monitoring networks, particularly the rationales or objectives for monitoring and the selection of monitoring sites. It is shown that jurisdictions are following principles of monitoring established by FHWA and that the design of monitoring networks is evolving to meet new challenges, including monitoring large-scale networks. Relevant outcomes and implications for practice are summarized. The researchers concluded that FHWA guidelines can be adapted to many circumstances and can increase information for decision making. Trail monitoring is informing decisions related to facility planning, investment, and safety

Statin use and adverse effects among adults \u3e 75 years of age: Insights from the Patient and Provider Assessment of Lipid Management (PALM) registry

Background: Current statin use and symptoms among older adults in routine community practice have not been well characterized since the release of the 2013 American College of Cardiology/American Heart Association guideline. Methods and results: We compared statin use and dosing between adults \u3e75 and ≤75 years old who were eligible for primary or secondary prevention statin use without considering guideline-recommended age criteria. The patients were treated at 138 US practices in the Patient and Provider Assessment of Lipid Management (PALM) registry in 2015. Patient surveys also evaluated reported symptoms while taking statins. Multivariable logistic regression models examined the association between older age and statin use and dosing. Among 6717 people enrolled, 1704 (25%) were \u3e75 years old. For primary prevention, use of any statin or high-dose statin did not vary by age group: any statin, 62.6% in those \u3e75 years old versus 63.1% in those ≤75 years old (P=0.83); high-dose statin, 10.2% versus 12.3% in the same groups (P=0.14). For secondary prevention, older patients were slightly less likely to receive any statin (80.1% versus 84.2% [P=0.003]; adjusted odds ratio, 0.81; 95% confidence interval, 0.66-1.01 [P=0.06]), but were much less likely to receive a high-intensity statin (23.5% versus 36.2% [PP=0.0001]). Among current statin users, older patients were slightly less likely to report any symptoms (41.3% versus 46.6%; P=0.003) or myalgias (27.3% versus 33.3%; Conclusions: Overall use of statins was similar for primary prevention in those aged \u3e75 years versus younger patients, yet older patients were less likely to receive high-intensity statins for secondary prevention. Statins appear to be similarly tolerated in older and younger adult

Patient-reported reasons for declining or discontinuing statin therapy: Insights from the PALM registry

Background: Many adults eligible for statin therapy for cardiovascular disease prevention are untreated. Our objective was to investigate patient‐reported reasons for statin underutilization, including noninitiation, refusal, and discontinuation.Methods and Results: This study included the 5693 adults recommended for statin therapy in the PALM (Patient and Provider Assessment of Lipid Management) registry. Patient surveys evaluated statin experience, reasons for declining or discontinuing statins, and beliefs about statins and cardiovascular disease risk. Overall, 1511 of 5693 adults (26.5%) were not on treatment. Of those not on a statin, 894 (59.2%) reported never being offered a statin, 153 (10.1%) declined a statin, and 464 (30.7%) had discontinued therapy. Women (relative risk: 1.22), black adults (relative risk: 1.48), and those without insurance (relative risk: 1.38) were most likely to report never being offered a statin. Fear of side effects and perceived side effects were the most common reasons cited for declining or discontinuing a statin. Compared with statin users, those who declined or discontinued statins were less likely to believe statins are safe (70.4% of current users vs. 36.9% of those who declined and 37.4% of those who discontinued) or effective (86.3%, 67.4%, and 69.1%, respectively). Willingness to take a statin was high; 67.7% of those never offered and 59.7% of patients who discontinued a statin would consider initiating or retrying a statin.Conclusions: More than half of patients eligible for statin therapy but not on treatment reported never being offered one by their doctor. Concern about side effects was the leading reason for statin refusal or discontinuation. Many patients were willing to reconsider statin therapy if offered

Measurement of low‐density lipoprotein cholesterol levels in primary and secondary prevention patients: Insights from the PALM registry

Background The 2013 American College of Cardiology/American Heart Association Guideline on the Treatment of Blood Cholesterol to Reduce Atherosclerotic Cardiovascular Risk in Adults recommended testing low-density lipoprotein cholesterol ( LDL -C) to identify untreated patients with LDL -C ≥190 mg/dL, assess lipid-lowering therapy adherence, and consider nonstatin therapy. We sought to determine whether clinician lipid testing practices were consistent with these guidelines. Methods and Results The PALM (Patient and Provider Assessment of Lipid Management) registry enrolled primary and secondary prevention patients from 140 US cardiology, endocrinology, and primary care offices in 2015 and captured demographic data, lipid treatment history, and the highest LDL -C level in the past 2 years. Core laboratory lipid levels were drawn at enrollment. Among 7627 patients, 2787 (36.5%) had no LDL -C levels measured in the 2 years before enrollment. Patients without chart-documented LDL -C levels were more often women, nonwhite, uninsured, and non-college graduates (all P\u3c0.01). Patients without prior lipid testing were less likely to receive statin treatment (72.6% versus 76.0%; P=0.0034), a high-intensity statin (21.5% versus 24.3%; P=0.016), nonstatin lipid-lowering therapy (24.8% versus 27.3%; P=0.037), and had higher core laboratory LDL -C levels at enrollment (median 97 versus 92 mg/dL; P\u3c0.0001) than patients with prior LDL -C testing. Of 166 individuals with core laboratory LDL -C levels ≥190 mg/dL, 36.1% had no LDL -C measurement in the prior 2 years, and 57.2% were not on a statin at the time of enrollment. Conclusions In routine clinical practice, LDL -C testing is associated with higher-intensity lipid-lowering treatment and lower achieved LDL -C level

Impaired cerebrovascular function in coronary artery disease patients and recovery following cardiac rehabilitation

© 2016 Anazodo, Shoemaker, Suskin, Ssali, Wang and St. Lawrence. Coronary artery disease (CAD) poses a risk to the cerebrovascular function of older adults and has been linked to impaired cognitive abilities. Using magnetic resonance perfusion imaging, we investigated changes in resting cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) to hypercapnia in 34 CAD patients and 21 age-matched controls. Gray matter volume (GMV)s were acquired and used as a confounding variable to separate changes in structure from function. Compared to healthy controls, CAD patients demonstrated reduced CBF in the superior frontal, anterior cingulate (AC), insular, pre- and post-central gyri, middle temporal, and superior temporal regions. Subsequent analysis of these regions demonstrated decreased CVR in the AC, insula, post-central and superior frontal regions. Except in the superior frontal and precentral regions, regional reductions in CBF and CVR were identified in brain areas where no detectable reductions in GMV were observed, demonstrating that these vascular changes were independent of brain atrophy. Because aerobic fitness training can improve brain function, potential changes in regional CBF were investigated in the CAD patients after completion of a 6-months exercise-based cardiac rehabilitation program. Increased CBF was observed in the bilateral AC, as well as recovery of CBF in the dorsal aspect of the right AC, where the magnitude of increased CBF was roughly equal to the reduction in CBF at baseline compared to controls. These exercise-related improvements in CBF in the AC is intriguing given the role of this area in cognitive processing and regulation of cardiovascular autonomic control

Toward a Control Oriented Model of Xerographic Marking Engines

This paper presents some preliminary results from a research collaboration concerning the modeling and control of color xerography. In this first communication of our work, we describe our efforts to develop a model for a monochrome marking engine. We adopt the technique of principal component analysis for choice of output coordinates and demonstrate preliminary experimental evidence suggesting that this procedure yields accuracy in data reconstruction superior to present industry practice. Preliminary analysis of the experimental evidence suggests that the process has a nonlinear component that we seek to model using a mixture of physical and empirical insight

Quantifying the Learning Curve in the Use of a Novel Vascular Closure Device An Analysis of the NCDR (National Cardiovascular Data Registry) CathPCI Registry

ObjectivesThis study sought to quantify the learning curve for the safety and effectiveness of a newly introduced vascular closure device through evaluation of the NCDR (National Cardiovascular Data Registry) CathPCI clinical outcomes registry.BackgroundThe impact of learning on the clinical outcomes complicates the assessment of the safety and efficacy during the early experience with newly introduced medical devices.MethodsWe performed a retrospective analysis of the relationship between cumulative institutional experience and clinical device success, defined as device deployment success and freedom from any vascular complications, for the StarClose vascular closure device (Abbott Vascular, Redwood City, California). Generalized estimating equation modeling was used to develop risk-adjusted clinical success predictions that were analyzed to quantify learning curve rates.ResultsA total of 107,710 procedures used at least 1 StarClose deployment, between January 1, 2006, and December 31, 2007, with overall clinical success increasing from 93% to 97% during the study period. The learning curve was triphasic, with an initial rapid learning phase, followed by a period of declining rates of success, followed finally by a recovery to a steady-state rate of improved device success. The rates of learning were influenced positively by diagnostic (vs. percutaneous coronary intervention) procedure use and teaching status and were affected inversely by annual institutional volume.ConclusionsAn institutional-level learning curve for the initial national experience of StarClose was triphasic, likely indicating changes in patient selection and expansion of number of operators during the initial phases of device adoption. The rate of learning was influenced by several institutional factors, including overall procedural volume, utilization for percutaneous coronary intervention procedures, and teaching status

Is Emotion Recognition Impaired in Individuals with Autism Spectrum Disorders?

Researchers have argued that individuals with autism spectrum disorders (ASDs) use an effortful “systematizing” process to recognize emotion expressions, whereas typically developing (TD) individuals use a more holistic process. If this is the case, individuals with ASDs should show slower and less efficient emotion recognition, particularly for socially complex emotions. We tested this account by assessing the speed and accuracy of emotion recognition while limiting exposure time and response window. Children and adolescents with ASDs showed quick and accurate recognition for most emotions, including pride, a socially complex emotion, and no differences emerged between ASD and TD groups. Furthermore, both groups trended toward higher accuracy when responding quickly, even though systematizing should promote a speed-accuracy trade-off for individuals with ASDs