The Road and the Ring: Solid Geometry in Tolkien\u27s Middle-earth

Considers the complex interplay of the Ring and the Road (“linear progress and circular stasis”), along with other related motifs of lines, circles, intersections and crossroads, spirals and spheres, hands and eyes in The Lord of the Rings

Clinical variables that increase the probability of pulmonary embolism diagnosis in symptomatic children

Abstract Background Pulmonary embolism (PE) in children carries a significant morbidity and mortality. We examined previously described factors in 2 cohorts of children tested for PE and identified novel factors. Methods We combined data from 2 retrospective cohorts. Patients up to age 21 years were included who underwent imaging or D‐dimer testing for PE, with positive radiologic testing being the gold standard. Combined predictor variables were examined by univariate analysis and then forward stepwise multivariable logistic regression. Results The combined data set yielded 1103 patients with 42 unique predictor variables, and 93 PE‐positive patients (8.4%), with a median age of 16 years. Univariate analysis retained 17 variables, and multivariable logistic regression found 9 significant variables with increased probability of PE diagnosis: age‐adjusted tachycardia, tachypnea, hypoxia, unilateral limb swelling, trauma/surgery requiring hospitalization in previous 4 weeks, prior thromboembolism, cancer, anemia, and leukocytosis. Conclusion This combined data set of children with suspected PE discovered factors that may contribute to a diagnosis of PE: hypoxia, unilateral limb swelling, trauma/surgery requiring hospitalization in previous 4 weeks, prior thromboembolism, and cancer, age‐adjusted tachycardia, tachypnea, anemia, and leukocytosis. Prospective testing is needed to determine which criteria should be used to initiate diagnostic testing for PE in children