Can electoral reforms such as an independent redistricting commission and the top-two primary create conditions that lead to better legislative representation? We explore this question by presenting a new method for measuring a key indicator of representation - the congruence between a legislator's ideological position and the average position of her district's voters. Our novel approach combines two methods: the joint classification of voters and political candidates on the same ideological scale, along with multilevel regression and post-stratification to estimate the position of the average voter across many districts in multiple elections. After validating our approach, we use it to study the recent impact of reforms in California, showing that they did not bring their hoped-for effects.

Deformable image registration is a powerful tool for mapping information, such as radiation therapy dose calculations, from one computed tomography image to another. However, deformable image registration is susceptible to mapping errors. Recently, an automated deformable image registration evaluation of confidence tool was proposed to predict voxel-specific deformable image registration dose mapping errors on a patient-by-patient basis. The purpose of this work is to conduct an extensive analysis of automated deformable image registration evaluation of confidence tool to show its effectiveness in estimating dose mapping errors. The proposed format of automated deformable image registration evaluation of confidence tool utilizes 4 simulated patient deformations (3 B-spline-based deformations and 1 rigid transformation) to predict the uncertainty in a deformable image registration algorithm's performance. This workflow is validated for 2 DIR algorithms (B-spline multipass from Velocity and Plastimatch) with 1 physical and 11 virtual phantoms, which have known ground-truth deformations, and with 3 pairs of real patient lung images, which have several hundred identified landmarks. The true dose mapping error distributions closely followed the Student t distributions predicted by automated deformable image registration evaluation of confidence tool for the validation tests: on average, the automated deformable image registration evaluation of confidence tool-produced confidence levels of 50%, 68%, and 95% contained 48.8%, 66.3%, and 93.8% and 50.1%, 67.6%, and 93.8% of the actual errors from Velocity and Plastimatch, respectively. Despite the sparsity of landmark points, the observed error distribution from the 3 lung patient data sets also followed the expected error distribution. The dose error distributions from automated deformable image registration evaluation of confidence tool also demonstrate good resemblance to the true dose error distributions. Automated deformable image registration evaluation of confidence tool was also found to produce accurate confidence intervals for the dose-volume histograms of the deformed dose.

BACKGROUND: Pneumonia from COVID-19 that results in ARDS may require invasive mechanical ventilation. This retrospective study assessed the characteristics and outcomes of subjects with COVID-19-associated ARDS versus ARDS (non-COVID) during the first 6 months of the COVID-19 pandemic in 2020. The primary objective was to determine whether mechanical ventilation duration differed between these cohorts and identify other potential contributory factors. METHODS: We retrospectively identified 73 subjects admitted between March 1 and August 12, 2020, with either COVID-19-associated ARDS (37) or ARDS (36) who were managed with the lung protective ventilator protocol and required >48 h of mechanical ventilation. Exclusion criteria were the following: <18 years old or the patient required tracheostomy or interfacility transfer. Demographic and baseline clinical data were collected at ARDS onset (ARDS day 0), with subsequent data collected on ARDS days 1-3, 5, 7, 10, 14, and 21. Comparisons were made by using the Wilcoxon rank-sum test (continuous variables) and chi-square test (categorical variables) stratified by COVID-19 status. A Cox proportional hazards model assessed the cause-specific hazard ratio for extubation. RESULTS: The median (interquartile range) mechanical ventilation duration among the subjects who survived to extubation was longer in those with COVID-19-ARDS versus the subjects with non-COVID ARDS: 10 (6-20) d versus 4 (2-8) d; P < .001. Hospital mortality was not different between the two groups (22% vs 39%; P = .11). The competing risks Cox proportional hazard analysis (fit among the total sample, including non-survivors) revealed that improved compliance of the respiratory system and oxygenation were associated with the probability of extubation. Oxygenation improved at a lower rate in the subjects with COVID-19-associated ARDS than in the subjects with non-COVID ARDS. CONCLUSIONS: Mechanical ventilation duration was longer in subjects with COVID-19-associated ARDS compared with the subjects with non-COVID ARDS, which may be explained by a lower rate of improvement in oxygenation status.

A 42-year-old woman at 29 weeks gestation via in vitro fertilization who presented with eight metastatic brain lesions received Gamma Knife stereotactic radiosurgery (GKSRS) at our institution. In this study, we report our clinical experience and a general procedure of determining the fetal dose from patient-specific treatment plans and we describe quality assurance measurements to guide the safe practice of multi-target GKSRS of pregnant patients. To estimate fetal dose pre-treatment, peripheral dose-to-focal dose ratios (PFRs) were measured in a phantom at the distance approximating the fundus of uterus. Post-treatment, fetal dose was calculated from the actual patient treatment plan. Quality assurance measurements were carried out via the extrapolation dosimetry method in a head phantom at increasing distances along the longitudinal axis. The measurements were then empirically fitted and the fetal dose was extracted from the curve. The computed and measured fetal dose values were compared with each other and associated radiation risk was estimated. Based on low estimated fetal dose from preliminary phantom measurements, the patient was accepted for GKSRS. Eight brain metastases were treated with prescription doses of 15-19 Gy over 143 min involving all collimator sizes as well as composite sector mixed shots. Direct fetal dose computation based on the actual patient's treatment plan estimated a maximum fetal dose of 0.253 cGy, which was in agreement with surface dose measurements at the level of the patient's uterine fundus during the actual treatment. Later phantom measurements also estimated fetal dose to be in the range of 0.21-0.28 cGy (dose extrapolation curve R² = 0.998). Using the National Council on Radiation Protection and Measurements (NCRP) population-based model, we estimate the fetal risk of secondary malignancy, which is the primary toxicity after 25 weeks gestation, to be less than 0.01%. Of note, the patient delivered the baby via scheduled cesarean section at 36 weeks without complications attributable to the GKSRS procedure. GKSRS of multiple brain metastases was demonstrated to be safe and feasible during pregnancy. The applicability of a general patient-specific fetal dose determination method was also demonstrated for the first time for such a treatment.