240 research outputs found

    Extrapolated High-Order Propagators for Path Integral Monte Carlo Simulations

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    We present a new class of high-order imaginary time propagators for path-integral Monte Carlo simulations by subtracting lower order propagators. By requiring all terms of the extrapolated propagator be sampled uniformly, the subtraction only affects the potential part of the path integral. The negligible violation of positivity of the resulting path integral at small time steps has no discernable affect on the accuracy of our method. Thus in principle arbitrarily high order algorithms can be devised for path-integral Monte Carlo simulations. We verify this claim is by showing that fourth, sixth, and eighth order convergence can indeed be achieved in solving for the ground state of strongly interacting quantum many-body systems such as bulk liquid 4^4He.Comment: 9 pages and 3 figures. Submitted to J. Chem. Phy

    Root curvature localizations as indicators of post length in various tooth groups

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    — The straight line length available for post preparations in pulps of 957 human teeth was evaluated. Analysis of radiographs in both buccolingual and mesiodistal directions showed that only 2.7% of the teeth studied were straight to the apex in both views. Average straight line lengths were calculated for the different types of teeth and used to offer guidelines for the length of post preparation. Buccal roots of maxillary molars and the mesial roots of the mandibular molars frequently showed straight line lengths insufficient for post preparations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72918/1/j.1600-9657.1986.tb00125.x.pd

    PAR14: ASSESSMENT OF THE RELATIONSHIP BETWEEN DISEASE SEVERITY, QUALITY OF LIFE AND WILLINGNESS TO PAY IN ASTHMA

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    Growing-up hand in hand with robots: Designing and evaluating child-robot interaction from a developmental perspective

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    Robots are becoming part of children's care, entertainment, education, social assistance and therapy. A steadily growing body of Human-Robot Interaction (HRI) research shows that child-robot interaction (CRI) holds promises to support children's development in novel ways. However, research has shown that technologies that do not take into account children's needs, abilities, interests, and developmental characteristics may have a limited or even negative impact on their physical, cognitive, social, emotional, and moral development. As a result, robotic technology that aims to support children via means of social interaction has to take the developmental perspective into consideration. With this workshop (the third of a series of workshops focusing CRI research), we aim to bring together researchers to discuss how a developmental perspective play a role for smart and natural interaction between robots and children. We invite participants to share their experiences on the challenges of taking the developmental perspective in CRI, such as long-term sustained interactions in the wild, involving children and other stakeholders in the design process and more. Looking across disciplinary boundaries, we hope to stimulate thought-provoking discussions on epistemology, methods, approaches, techniques, interaction scenarios and design principles focused on supporting children's development through interaction with robotic technology. Our goal does not only focus on the conception and formulation of the outcomes in the context of the workshop venue, but also on their establishment and availability for the HRI community in different forms

    Hypertension treatment intensification among stroke survivors with uncontrolled blood pressure

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    Objective The study objective was to evaluate a pharmacist hypertension care management program within the patient-centered medical home. Methods This was a retrospective case-control study. Cases included all patients with hypertension who were referred to the care management program, and controls included patients with hypertension who were not referred to the program during the same 1-year period. Each case was matched to a maximum of 3 controls on the basis of primary care physician, age ±5 years, gender, diagnoses of diabetes and kidney disease, baseline systolic blood pressure ±10 mm Hg, and number of unique antihypertensive medications. Pharmacists provided a hypertension care management program under an approved scope of practice that allowed pharmacists to meet individually with patients, adjust medications, and provide patient education. Primary outcomes were systolic blood pressure and diastolic blood pressure at 6 and 12 months. Multivariate regression models compared each blood pressure end point between cases and controls adjusting for age, comorbidities, baseline blood pressure, and baseline number of blood pressure medications. Results A total of 573 patients were referred to the hypertension program; 86% (465/543) had at least 1 matched control and were included as cases in the analyses; 3:1 matching was achieved in 90% (418/465) of cases. At baseline, cases and controls did not differ with respect to age, gender, race, or comorbidity; baseline blood pressure was higher (139.9/80.0 mm Hg vs 136.7/78.2 mm Hg, P ≤ .0002) in the cases compared with controls. Multivariate regression modeling identified significantly lower systolic blood pressure for the cases compared with controls at both 6 and 12 months (6-month risk ratio [RR], 9.7; 95% confidence interval [CI], 2.7-35.3; 12-month RR, 20.3; 95% CI, 4.1-99.2; P < .01 for both comparisons). Diastolic blood pressure was significantly lower at 12 months (RR, 2.9; 95% CI, 1.2-7.1; P < .01) but not at 6 months (RR, 1.0; 95% CI, 0.31-3.4; P = .9) for the cases compared with controls. Conclusions Patients who were referred to the pharmacist hypertension care management program had a significant improvement in most blood pressure outcomes. This program may be an effective method of improving blood pressure control among patients in a medical home model of primary care

    Processes of Care Associated With Risk of Mortality and Recurrent Stroke Among Patients With Transient Ischemic Attack and Nonsevere Ischemic Stroke

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    Importance: Early evaluation and management of patients with transient ischemic attack (TIA) and nonsevere ischemic stroke improves outcomes. Objective: To identify processes of care associated with reduced risk of death or recurrent stroke among patients with TIA or nonsevere ischemic stroke. Design, Setting, and Participants: This cohort study included all patients with TIA or nonsevere ischemic stroke at Department of Veterans Affairs emergency department or inpatient settings from October 2010 to September 2011. Multivariable logistic regression was used to model associations of processes of care and without-fail care, defined as receiving all guideline-concordant processes of care for which patients are eligible, with risk of death and recurrent stroke. Data were analyzed from March 2018 to April 2019. Main Outcomes and Measures: Risk of all-cause mortality and recurrent ischemic stroke at 90 days and 1 year was calculated. Overall, 28 processes of care were examined. Without-fail care was assessed for 6 processes: brain imaging, carotid artery imaging, hypertension medication intensification, high- or moderate-potency statin therapy, antithrombotics, and anticoagulation for atrial fibrillation. Results: Among 8076 patients, the mean (SD) age was 67.8 (11.6) years, 7752 patients (96.0%) were men, 5929 (73.4%) were white, 474 (6.1%) had a recurrent ischemic stroke within 90 days, 793 (10.7%) had a recurrent ischemic stroke within 1 year, 320 (4.0%) died within 90 days, and 814 (10.1%) died within 1 year. Overall, 9 processes were independently associated with lower odds of both 90-day and 1-year mortality after adjustment for multiple comparisons: carotid artery imaging (90-day adjusted odds ratio [aOR], 0.49; 95% CI, 0.38-0.63; 1-year aOR, 0.61; 95% CI, 0.52-0.72), antihypertensive medication class (90-day aOR, 0.58; 95% CI, 0.45-0.74; 1-year aOR, 0.70; 95% CI, 0.60-0.83), lipid measurement (90-day aOR, 0.68; 95% CI, 0.51-0.90; 1-year aOR, 0.64; 95% CI, 0.53-0.78), lipid management (90-day aOR, 0.46; 95% CI, 0.33-0.65; 1-year aOR, 0.67; 95% CI, 0.53-0.85), discharged receiving statin medication (90-day aOR, 0.51; 95% CI, 0.36-0.73; 1-year aOR, 0.70; 95% CI, 0.55-0.88), cholesterol-lowering medication intensification (90-day aOR, 0.47; 95% CI, 0.26-0.83; 1-year aOR, 0.56; 95% CI, 0.41-0.77), antithrombotics by day 2 (90-day aOR, 0.56; 95% CI, 0.40-0.79; 1-year aOR, 0.69; 95% CI, 0.55-0.87) or at discharge (90-day aOR, 0.59; 95% CI, 0.41-0.86; 1-year aOR, 0.69; 95% CI, 0.54-0.88), and neurology consultation (90-day aOR, 0.67; 95% CI, 0.52-0.87; 1-year aOR, 0.74; 95% CI, 0.63-0.87). Anticoagulation for atrial fibrillation was associated with lower odds of 1-year mortality only (aOR, 0.59; 95% CI, 0.40-0.85). No processes were associated with reduced risk of recurrent stroke after adjustment for multiple comparisons. The rate of without-fail care was 15.3%; 1216 patients received all guideline-concordant processes of care for which they were eligible. Without-fail care was associated with a 31.2% lower odds of 1-year mortality (aOR, 0.69; 95% CI, 0.55-0.87) but was not independently associated with stroke risk. Conclusions and Relevance: Patients who received 6 readily available processes of care had lower adjusted mortality 1 year after TIA or nonsevere ischemic stroke. Clinicians caring for patients with TIA and nonsevere ischemic stroke should seek to ensure that patients receive all guideline-concordant processes of care for which they are eligible

    Reducing prescribing errors through creatinine clearance alert redesign

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    Background Literature has shown that computerized creatinine clearance alerts reduce errors during prescribing, and applying human factors principles may further reduce errors. Our objective was to apply human factors principles to creatinine clearance alert design and assess whether the redesigned alerts increase usability and reduce prescribing errors compared with the original alerts. Methods Twenty Veterans Affairs (VA) outpatient providers (14 physicians, 2 nurse practitioners, and 4 clinical pharmacists) completed 2 usability sessions in a counterbalanced study to evaluate original and redesigned alerts. Each session consisted of fictional patient scenarios with 3 medications that warranted prescribing changes because of renal impairment, each associated with creatinine clearance alerts. Quantitative and qualitative data were collected to assess alert usability and the occurrence of prescribing errors. Results There were 43% fewer prescribing errors with the redesigned alerts compared with the original alerts (P = .001). Compared with the original alerts, redesigned alerts significantly reduced prescribing errors for allopurinol and ibuprofen (85% vs 40% and 65% vs 25%, P = .012 and P = .008, respectively), but not for spironolactone (85% vs 65%). Nine providers (45%) voiced confusion about why the alert was appearing when they encountered the original alert design. When laboratory links were presented on the redesigned alert, laboratory information was accessed 3.5 times more frequently. Conclusions Although prescribing errors were high with both alert designs, the redesigned alerts significantly improved prescribing outcomes. This investigation provides some of the first evidence on how alerts may be designed to support safer prescribing for patients with renal impairment

    Short-Term Medical Costs of a VHA Health Information Exchange: A CHEERS-Compliant Article.

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    The Virtual Lifetime Electronic Record (VLER) Health program provides the Veterans Health Administration (VHA) a framework whereby VHA providers can access the veterans’ electronic health record information to coordinate healthcare across multiple sites of care. As an early adopter of VLER, the Indianapolis VHA and Regenstrief Institute implemented a regional demonstration program involving bi-directional health information exchange (HIE) between VHA and non-VHA providers.The aim of the study is to determine whether implementation of VLER HIE reduces 1 year VHA medical costs.A cohort evaluation with a concurrent control group compared VHA healthcare costs using propensity score adjustment. A CHEERs compliant checklist was used to conduct the cost evaluation.Patients were enrolled in the VLER program onsite at the Indianapolis VHA in outpatient clinics or through the release-of-information office.VHA cost data (in 2014 dollars) were obtained for both enrolled and nonenrolled (control) patients for 1 year prior to, and 1 year after, the index date of patient enrollment.There were 6104 patients enrolled in VLER and 45,700 patients in the control group. The annual adjusted total cost difference per patient was associated with a higher cost for VLER enrollees 1152(951152 (95% CI: 807–1433) (P < 0.01) (in 2014 dollars) than VLER nonenrollees.Short-term evaluation of this demonstration project did not show immediate reductions in healthcare cost as might be expected if HIE decreased redundant medical tests and treatments. Cost reductions from shared health information may be realized with longer time horizons

    Communication: Dopant-induced solvation of alkalis in liquid helium nanodroplets

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    Alkali metal atoms and small alkali clusters are classic heliophobes and when in contact with liquid helium they reside in a dimple on the surface. Here we show that alkalis can be induced to submerge into liquid helium when a highly polarizable co-solute, C60, is added to a helium nanodroplet. Evidence is presented that shows that all sodium clusters, and probably single Na atoms, enter the helium droplet in the presence of C60. Even clusters of cesium, an extreme heliophobe, dissolve in liquid helium when C60 is added. The sole exception is atomic Cs, which remains at the surface

    Robot George: interactive continuous learning of visual concepts

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    The video presents the robot George learning visual concepts in dialogue with a tuto
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