Plasmoid Formation and Strong Radiative Cooling in a Driven Magnetic Reconnection Experiment.

We present the first experimental study of plasmoid formation in a magnetic reconnection layer undergoing rapid radiative cooling, a regime relevant to extreme astrophysical plasmas. Two exploding aluminum wire arrays, driven by the Z machine, generate a reconnection layer (S_{L}≈120) in which the cooling rate far exceeds the hydrodynamic transit rate (τ_{hydro}/τ_{cool}>100). The reconnection layer generates a transient burst of >1  keV x-ray emission, consistent with the formation and subsequent rapid cooling of the layer.

Hydrodynamic Mechanism for Clumping along the Equatorial Rings of SN1987A and Other Stars.

An explanation for the origin and number of clumps along the equatorial ring of Supernova 1987A has eluded decades of research. Our linear analysis and hydrodynamic simulations of the expanding ring prior to the supernova reveal that it is subject to the Crow instability between vortex cores. The dominant wave number is remarkably consistent with the number of clumps, suggesting that the Crow instability stimulates clump formation.

Saturation of Vortex Rings Ejected from Shock-Accelerated Interfaces.

Structures evoking vortex rings can be discerned in shock-accelerated flows ranging from astrophysics to inertial confinement fusion. By constructing an analogy between vortex rings produced in conventional propulsion systems and rings generated by a shock impinging upon a high-aspect-ratio protrusion along a material interface, we extend classical, constant-density vortex-ring theory to compressible multifluid flows. We further demonstrate saturation of such vortex rings as the protrusion aspect ratio is increased, thus explaining morphological differences observed in practice.

Purtscher-Like Retinopathy with Cardioembolic Stroke: Case Report and Literature Review.

Purtscher-like retinopathy (PUR) is a rare condition characterized by sudden vision loss with associated retinal white patches thought to be due to precapillary arteriolar occlusion. We present a case of PUR associated with a cardioembolic stroke in a patient following temporary cessation of anticoagulant therapy for a surgical procedure. Our patient presented with multiple risk factors for PUR and classic signs and symptoms including multiple peripapillary white retinal lesions near arterioles and sudden unilateral decrease in visual acuity.