Generating nested quadrature rules with positive weights based on arbitrary sample sets

For the purpose of uncertainty propagation a new quadrature rule technique is proposed that has positive weights, has high degree, and is constructed using onl

Bayesian model calibration with interpolating polynomials based on adaptively weighted Leja nodes

An efficient algorithm is proposed for Bayesian model calibration, which is commonly used to estimate the model parameters of non-linear, computationally expens

Bayesian model calibration with interpolating polynomials based on adaptively weighted Leja nodes

An efficient algorithm is proposed for Bayesian model calibration, which is commonly used to estimate the model parameters of non-linear, computationally expensive models using measurement data. The approach is based on Bayesian statistics: using a prior distribution and a likelihood, the posterior distribution is obtained through application of Bayes' law. Our novel algorithm to accurately determine this posterior requires significantly fewer discrete model evaluations than traditional Monte Carlo methods. The key idea is to replace the expensive model by an interpolating surrogate model and to construct the interpolating nodal set maximizing the accuracy of the posterior. To determine such a nodal set an extension to weighted Leja nodes is introduced, based on a new weighting function. We prove that the convergence of the posterior has the same rate as the convergence of the model. If the convergence of the posterior is measured in the Kullback-Leibler divergence, the rate doubles. The algorithm and its theoretical properties are verified in three different test cases: analytical cases that confirm the correctness of the theoretical findings, Burgers' equation to show its applicability in implicit problems, and finally the calibration of the closure parameters of a turbulence model to show the effectiveness for computationally expensive problems

A disease-specific measure of health-related quality of life for use in adults with immune thrombocytopenic purpura: Its development and validation

BACKGROUND: No validated disease-specific measures are available to assess health-related quality of life (HRQoL) in adult subjects with immune thrombocytopenic purpura (ITP). Therefore, we sought to develop and validate the ITP-Patient Assessment Questionnaire (ITP-PAQ) for adult subjects with ITP. METHODS: Information from literature reviews, focus groups with subjects, and clinicians were used to develop 50 ITP-PAQ items. Factor analyses were conducted to develop the scale structure and reduce the number of items. The final 44-item ITP-PAQ, which includes ten scales [Symptoms (S), Bother-Physical Health (B), Fatigue/Sleep (FT), Activity (A), Fear (FR), Psychological Health (PH), Work (W), Social Activity (SA), Women's Reproductive Health (RH), and Overall (QoL)], was self-administered to adult ITP subjects at baseline and 7–10 days later. Test-retest reliability, internal consistency reliability, construct and known groups validity of the final ITP-PAQ were evaluated. RESULTS: Seventy-three subjects with ITP completed the questionnaire twice. Test-retest reliability, as measured by the intra-class correlation, ranged from 0.52–0.90. Internal consistency reliability was demonstrated with Cronbach's alpha for all scales above the acceptable level of 0.70 (range: 0.71–0.92), except for RH (0.66). Construct validity, assessed by correlating ITP-PAQ scales with established measures (Short Form-36 v.1, SF-36 and Center for Epidemiologic Studies Depression Scale, CES-D), was demonstrated through moderate correlations between the ITP-PAQ SA and SF-36 Social Function scales (r = 0.67), and between ITP-PAQ PH and SF-36 Mental Health Scales (r = 0.63). Moderate to strong inter-scale correlations were reported between ITP-PAQ scales and the CES-D, except for the RH scale. Known groups validity was evaluated by comparing mean scores for groups that differed clinically. Statistically significant differences (p < 0.01) were observed when subjects were categorized by treatment status [S, FT, B, A, PH, and QoL, perceived effectiveness of ITP treatment [S], and time elapsed since ITP diagnosis [PH]. CONCLUSION: Results provide preliminary evidence of the reliability and validity of the ITP-PAQ in adult subjects with ITP. Further work should be conducted to assess the responsiveness and to estimate the minimal clinical important difference of the ITP-PAQ to more fully understand the impact of ITP and its treatments on HRQoL

Adult Attachment and Personal Recovery in Clients With a Psychotic Disorder

Background: Personal recovery has become a key objective in the treatment of clients with a psychotic disorder. So far it has been established that the two attachment dimensions, ie, anxious and avoidant, are negatively associated with subjective well-being, self-esteem and hope. This study is the first to explore whether attachment styles are related to personal recovery in this population. Aims: To study the effects of anxious and avoidant attachment on personal recovery in a population with a psychotic disorder. Method: This cross-sectional study is part of the UP's multicenter cohort study on recovery from psychotic disorders, in which 265 participants are currently included. Attachment was assessed using the Psychosis Attachment Measure, including the anxious and avoidant attachment dimensions. Personal recovery was measured using the Recovering Quality of Life-10 (ReQOL-10) and the Individual Recovery Outcomes Counter (I.ROC). Regression analysis was used to investigate the effect of attachment on personal recovery. Results: We found negative effects of the anxious attachment style on the total scores of the ReQoL-10 (b = -4.54, SE = 0.69, β = β0.37) and the I.ROC (b = -5.21, SE = 0.89, β = -0.32). Although there were also negative effects of the avoidant attachment style on the total scores of the ReQoL-10 (b = -3.08, SE = 0.93, β = -0.18) and the I.ROC (b = -4.24, SE = 1.24, β = -0.19), these were less pronounced. Conclusion: Results show that both forms of insecure attachment (anxious and avoidant) are related to poorer personal recovery in clients with a psychotic disorder.</p