This study examines the impact of embedded versus nonembedded (unilateral) news coverage during the U.S. invasion and occupation of Iraq. A content analysis was conducted of the Washington Post, New York Times, Los Angeles Times, and Chicago Tribune news coverage of the invasion and occupation examining whether embedded and nonembedded new reports were different and, if so, how. News reports were examined for differences in tone toward the military, trust in the military, framing, and authoritativeness. The results of the study revealed significant differences in overall tone toward the military, trust in military personnel, framing, and authoritativeness between embedded and nonembedded articles.

The coronavirus SARS-CoV-2 (COVID-19) pandemic has offered a unique set of challenges to the medical community often requiring prolonged treatment algorithms. The illness, afflicting more than 7.3 million people worldwide with estimates of 5-20% requiring critical care, has become a burden on the healthcare community. These critically ill patients who acquire the severe form of the disease routinely require prolonged invasive mechanical ventilation. The questions then arise, "when and for whom does tracheostomy become indicated," and "how to safely perform a tracheostomy in this patient population." With consideration to aerosolization of the virus, we have derived and instituted a protocol at a community institution with aims of reducing provider risk while safely performing a tracheostomy. An open tracheostomy was performed at bedside, within a negative pressure intensive care unit (ICU) setting, utilizing a closed-circuit technique as described in this text. A total of 17 tracheostomies were performed employing the described technique. Minimal complications were noted throughout the study and no adverse oxygenation events were observed with an average total apneic time of 106 seconds. An acceptable mortality rate of 23% was observed given the lethal nature of this disease in ventilated, critically ill patients. No nosocomial transmission of the virus was documented for all team members. This protocol can be used to determine efficacy and safely execute a tracheostomy in COVID-19 patients. As information about COVID-19 continues to unfold, protocols for high risk procedures will need to fluidly evolve.

No abstract

Separation of variables is one of the oldest techniques for solving certain classes of partial differential equations (PDEs). As is the case with many other solution techniques for differential equations, separation of variables may be codified within the broader framework of symmetry analysis. Though the separation of variables technique is frequently used in the nuclear engineering context with various equations describing neutron transport, its connection to the symmetries of those equations has not yet been thoroughly established. It is thus the purpose of this work to establish that connection using neutron diffusion as both an initial step toward analysis of more generally applicable equations, and as a connection to previous results in related problems. Using Lie group analysis, it is found that the traditional space-time separable solution of the neutron diffusion equation (featuring a single αeigenvalue) corresponds to time translation and flux scaling symmetries. Additional solutions of this equation are also constructed using its broader symmetry set. IntroductionSeparation of variables is one of the oldest techniques for solving certain classes of partial differential equations (PDEs). Like many other such methods, it is often employed as a specific element out of a 'bag of tricks', so that given a certain equation the technique can either be expected to apply, or not. In this more general sense, it was not until the late 19th century that S. Lie began his investigation into a 'unification theory' of solution techniques for differential equations, inspired in part by the preceding successful application of group theory to algebraic equations. Lie was successful in his aim, and indeed it has since been found that a wide variety of solution techniques for differential equations can be integrated into the broader framework of symmetry analysis (as now set forth in rigorous detail by Ovsiannikov [1], Bluman and Anco [2], Ibragimov [3], Hydon [4], Olver [5], Cantwell [6], Stephani [7], and many others). Beginning in the 1970s, C Boyer, E Kalnins, and W Miller embarked upon a thorough program of analyzing the connection between Lie symmetries, separation of variables, and special functions in a variety of contexts, including Schrödinger equations, Helmholtz and Laplace equations, harmonic oscillator equations, Hamilton-Jacobi equations, wave equations, and multitudinous other structures in numerous coordinate systems and spaces. This effort is largely summarized in two books and a survey by Miller [8-10]. Following this work, a generalized attempt at demonstrating the connection in question was provided by Gegelia and Markovski [11]. Additional studies have been performed by Chou and Qu [12] for nonlinear diffusion-convection equations and Estevez et al [13] for a porous medium equation, and Polyanin and Zhurov [14] for the axisymmetric unsteady boundary-layer equations, to name a few. Modern developments intended to reconcile (or not) separation of variables within the symmetry analysis framework appear t...

No abstract