Mark Levi

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The model of a bicycle is a unit segment AB that can move in the plane so that it remains tangent to the trajectory of point A (the rear wheel is fixed on the bicycle frame); the same model describes the hatchet planimeter. The trajectory of the front wheel and the initial position of the bicycle uniquely determine its motion and its terminal position; the(More)
1. INTRODUCTION: THE PONCELET CLOSURE THEOREM. The Poncelet closure theorem (or Poncelet porism) is a classical result of projective geometry. Given nested ellipses γ and , with γ inside , one plays the following game: starting at a point x on , draw a tangent line to γ until it intersects at point y, repeat the construction , starting with y, and so on.(More)
Determinants of amphetamine (AMPH)-induced neurotoxicity are poorly understood. The role of lipopolysaccharides (LPS) and organ injury in AMPH-induced neurotoxicity was examined in adult male Sprague-Dawley rats that were give AMPH and became hyperthermic during the exposure. Environmentally-induced hyperthermia (EIH) in the rat was compared to AMPH to(More)
Eleven direct refractory dies were made from separate polysulfide rubber impressions of two Dentoform teeth which had been prepared for porcelain-fused-to-gold veneer crowns with labial porcelain shoulders. Porcelain veneer crowns were built and fired directly on the dies, following the manufacturer's instructions and using a common laboratory technique.(More)