Rapid analysis of local data to inform off-label tocilizumab use early in the COVID-19 pandemic

The interleukin-6 receptor antagonist tocilizumab became widely used early in the coronavirus disease 2019 (COVID-19) pandemic based on small observational studies that suggested clinical benefit in COVID-19 patients with a hyperinflammatory state. To inform our local treatment algorithms in the absence of randomized clinical trial results, we performed a rapid analysis of the first 11 hospitalized COVID-19 patients treated with tocilizumab at our academic medical center. We report their early clinical outcomes and describe the process by which we assembled a team of diverse trainees and stakeholders to extract, analyze, and disseminate data during a time of clinical uncertainty

Preliminary investigation of trapped particle instabilities in EBT

An investigation is presented of the role which trapped particles might play in the drift wave stability of ELMO Bumpy Torus (EBT). The model adopted consists of a bounce-averaged drift kinetic equation with a Krook collision operator. Care has been taken to model, at least in an elementary way, the features which distinguish the physics of EBT from that of tokamaks, namely the large magnitude and velocity space dependence of the poloidal drift frequency ..cap omega.., the relatively small collisionality ..nu../..cap omega.., the enhancement of ..nu../sub eff/ for passing particles, and the closed nature of the field lines. Instabilities are found which have a somewhat dissipative character, however the precessional drift is found to be a significant stabilizing influence. In most cases, the modes are completely stabilized when ..omega../sub *//l..cap omega.. approximately equal to 1 for normal gradients. For reversed gradients (..omega../sub *//l..cap omega.. < 0), stability is greatly enhanced

Optimization of transport in stellarators

Here we relate two stellarator transport optimization schemes to single particle orbits. We also show that reducing transport in the 1/..nu.. regime reduces transport over a much broader range of collisionality. 6 refs., 2 figs

Comparison of analytic and full guiding center behavior at a trapped-passing interface in stellarators

The toroidal adiabatic invariant, can be used to describe both trapped and passing particle motion. Analytic expressions have also been developed to treat transitional particles, which are sometimes trapped, and sometimes passing. We have developed analytic descriptions using a non-canonical Hamiltonian formalism. Here we compare analytic approaches with solutions to the full guiding center equations of motion for a model stellarator magnetic and electric field. We also develop the analytic result directly from the equations of motion, since this clarifies some points, particularly for transitional particles

Truck Pavement Interactions: Requisite Research

A framework for consideration of the effects of dynamic loads on pavement performance is presented. The paper discusses requisite research which will permit both the pavement engineer and the truck designer to effectively utilize such a framework to arrive at optimal solutions which will result in overall savings to the agencies responsible for design, construction, maintenance, and rehabilitation of pavement facilities and to the users of the facilities as well.Included is a discussion of needed research to evaluate: the dynamic response of jointed portland cement concrete pavements to load, the influence of dynamic loads on the development of rutting in asphalt concrete pavements, and the development of new suspension concepts to reduce dynamic load variations with pavement roughness.Also included are recommendations for field measurement procedures to truly identify dynamic load spectra, methods to identify pavement profiles to reflect the effects of such profiles on truck suspension performance, and measurements to evaluate the methodology developed within the proposed framework

Truck Pavement Interactions: Requisite Research

A framework for consideration of the effects of dynamic loads on pavement performance is presented. The paper discusses requisite research which will permit both the pavement engineer and the truck designer to effectively utilize such a framework to arrive at optimal solutions which will result in overall savings to the agencies responsible for design, construction, maintenance, and rehabilitation of pavement facilities and to the users of the facilities as well.Included is a discussion of needed research to evaluate: the dynamic response of jointed portland cement concrete pavements to load, the influence of dynamic loads on the development of rutting in asphalt concrete pavements, and the development of new suspension concepts to reduce dynamic load variations with pavement roughness.Also included are recommendations for field measurement procedures to truly identify dynamic load spectra, methods to identify pavement profiles to reflect the effects of such profiles on truck suspension performance, and measurements to evaluate the methodology developed within the proposed framework

Numerical methods for stellarator optimization

A numerical optimization procedure utilizing an inverse 3-D equilibrium solver, a Mercier stability assessment, a deeply-trapped-particle loss assessment, and a nonlinear optimization package has been used to produce low aspect ratio (A = 4) stellarator designs. These designs combine good stability and improved transport with a compact configuration. 7 refs., 2 figs., 1 tab