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The Vishniac instability was posited as an instability that could affect supernova remnants in their late stage of evolution when subject to strong radiative cooling, which can drive the effective ratio of specific heats below 1.3. The potential importance of this instability to these astrophysical objects has motivated a number of laser-driven laboratory studies. However, the Vishniac instability is essentially a dynamical instability that should operate independently of whatever physical processes happen to reduce the ratio of specific heats. In this paper, we examine the possibility that ionization and molecular dissociation processes can achieve this, and we show that this is possible for a certain range of shock wave Mach numbers for ionizing/dissociating shock waves propagating into cold atomic and molecular gases.

We show, using three dimensional hybrid particle-in-cell simulations, that fast electron transport is improved in a resistive guide when using a linear decreasing gradient in the resistivity between the guide and substrate. We observe increased heating-at-depth along the guide and significantly reduced heating inhomogeneity. These improvements result from an increase in the width of the collimating magnetic field, improving fast electron confinement and limiting the growth of magnetic fields in the interior of the guide.

Resuscitative endovascular balloon occlusion of the aorta (REBOA), used to temporize noncompressible and junctional hemorrhage, may be deployable to the forward environment. Our hypothesis was that nonsurgeon physicians and high-level military medical technicians would be able to learn the theory and insertion of REBOA.US Army Special Operations Command medical personnel without prior endovascular experience were included. All participants received didactic instruction of the Basic Endovascular Skills for Trauma Course™ together, with individual evaluation of technical skills. A pretest and a posttest were administered to assess comprehension.Four members of US Army Special Operations Command-two nonsurgeon physicians, one physician assistant, and one Special Operations Combat Medic-were included. REBOA procedural times moving from trial 1 to trial 6 decreased significantly from 186 ± 18.7 seconds to 83 ± 10.3 seconds (ρ.0001). All participants demonstrated safe REBOA insertion and verbalized the indications for REBOA insertion and removal through all trials. All five procedural tasks were performed correctly by each participant. Comprehension and knowledge between the pretest and posttest improved significantly from 67.6 ± 7.3% to 81.3 ± 8.1% (ρ = .039).This study demonstrates that nonsurgeon and nonphysician providers can learn the steps required for REBOA after arterial access is established. Although insertion is relatively straightforward, the inability to gain arterial access percutaneously is prohibitive in providers without a surgical skillset and should be the focus of further training.

The radiation pressure of next generation ultra-high intensity ($>10^{23}$ W/cm$^{2}$) lasers could efficiently accelerate ions to GeV energies. However, nonlinear quantum-electrodynamic effects play an important role in the interaction of these laser pulses with matter. Here we show that these effects may lead to the production of an extremely dense ($\sim10^{24}$ cm$^{-3}$) pair-plasma which absorbs the laser pulse consequently reducing the accelerated ion energy and energy conversion efficiency by up to 30-50\% \& 50-65\%, respectively. Thus we identify the regimes of laser-matter interaction where either ions are efficiently accelerated or dense pair-plasmas are produced as a guide for future experiments.

Using 3 dimensional numerical simulations, this paper shows that grading the atomic number and thus the resistivity at the interface between an embedded high atomic number guide element and a lower atomic number substrate enhances the growth of a resistive magnetic field. This can lead to a large integrated magnetic flux density, which is fundamental to confining higher energy fast electrons. This results in significant improvements in both magnetic collimation and fast-electron-temperature uniformity across the guiding. The graded interface target provides a method for resistive guiding that is tolerant to laser pointing.

Effects of a soy protein diet on oxidant and anti-oxidant levels in selected rodent tissues were investigated under simulated microgravity. Methods: Adult Male Rats were maintained either on a regular Purina Rat chow or on a 9.6% soy protein diet and allowed to remain in either non-suspended (control) or hind-limb-suspended (HLS) state via their tails at a 30 degree angle for 14 days. Body weights, food and water intakes were monitored daily during the entire study period. Hematological parameters, oxidant and. antioxidant levels in the brain, liver and pancreatic tissues were measured. Results: At term, the body weights of the hind limb suspended animals were found significantly decreased when compared with the non-suspended controls, p