This study tests if the drives to empathize (E) and systemize (S), measured by the Systemizing Quotient-Revised (SQ-R) and Empathy Quotient (EQ), show effects of sex and academic degree. The responses of 419 students from the Humanities and the Physical Sciences were analyzed in terms of the E-S theory predictions. Results confirm that there is an interaction between sex, degree and the drive to empathize relative to systemize. Female students in the Humanities on average had a stronger drive to empathize than to systemize in comparison to males in the Humanities. Male students in the Sciences on average had a stronger drive to systemize than to empathize in comparison to females in the Sciences. Finally, students in the sciences on average had a stronger drive to systemize more than to empathize, irrespective of their sex. The reverse is true for students in the Humanities. These results strongly replicate earlier findings.

Key Points Question How do incidence and relative risk of contracting COVID-19 from the original wild-type SARS-CoV-2 strain in adolescents and youth compare with that in older adults in the US? Findings Results of this cross-sectional study using state health department data from the start of the pandemic through fall 2020 indicate that, in 16 of the 19 states examined, the incidence rate and relative risk of COVID-19 infection from wild-type SARS-CoV-2 were significantly greater in adolescents and youth than in older adults. For example, in Florida, the incidence rate in adolescents and youth was 0.055 compared with 0.028 in older adults—adolescents and youth had 1.94 times the risk of contracting COVID-19 compared with older adults. Meaning These results suggest that, contrary to reports from Europe and Asia, infection rates and relative risk among US adolescents and youth exceeded that in older adults from the start of the COVID-19 pandemic through fall 2020, before vaccines were available.

A Lagrangian panel method is presented for vortex sheet motion in threedimensional (3D) flow. The sheet is represented by a set of quadrilateral panels having a tree structure. The panels have active particles that carry circulation and passive particles used for adaptive refinement. The Biot-Savart kernel is regularized and the velocity is evaluated by a treecode. The method is applied to compute the azimuthal instability of a vortex ring, starting from a perturbed circular disc vortex sheet initial condition. Details of the core dynamics are clarified by tracking material lines on the sheet surface. Results are presented showing the following sequence of events: spiral roll-up of the sheet into a ring, wavy deformation of the ring axis, first collapse of the vortex core in each wavelength, second collapse of the vortex core out of phase with the first collapse, formation of loops wrapped around the core and radial ejection of ringlets. The collapse of the vortex core is correlated with converging axial flow.

Abstract. We study torsional rigidity for graph and quantum graph analogs of well-known pairs of isospectral non-isometric planar domains. We prove that such isospectral pairs are distinguished by torsional rigidity.

A hierarchical panel method for representing vortex sheet surface motion in 3D flow is presented. Unlike previously employed filament methods, each panel is a leaf of the tree, so it can be subdivided locally, which allows an efficient adaptive point insertion. In addition, we developed curvature-based insertion criteria which allow to localize point insertion to the most complicated curved regions of the sheet. The particles representing the sheet are advected by a regularized Biot-Savart integral with Rosenhead-Moore kernel. The particle velocities are evaluated by an adaptive treecode algorithm based on Taylor expansions in Cartesian coordinates due to Lindsay and Krasny (2001). The method allows to consider much later stages of a vortex ring instability, which may shed light on this complicated flow phase directly leading to the turbulent flow.