This paper examines two-dimensional vortex motion in a shear-flow with nonuniform vorticity. Typically, a vortex travels to an extremum in the background vorticity distribution. In general, the rate of this migration increases with the magnitude of the background vorticity gradient; however, a retrograde vortex, which rotates against the local shear, moves orders of magnitude faster than a prog...

introduction: all instrumentation techniques have been reported to be associated with extrusion of infected debris. the aim of this study was to evaluate the number of bacteria extruded apically from extracted teeth ex vivo after canal instrumentation using the two engine-driven techniques utilizing nickel-titanium instruments (flex master and mtwo). materials and methods: seventy extracted max...

INTRODUCTION Root canal irrigation carries a risk of extrusion of irrigant into the periapical tissues. The objective of this study was to compare different irrigation systems in matched pairs of teeth prepared to an apical size of 35.06 and 50.06 by measuring the frequency and extent of apical extrusion of sodium hypochlorite (NaOCl) into a simulated periapical environment. The null hypothesis...

We conducted a longitudinal study (duration 2 years), including 294 individuals (mean age 45 years, 58% female), in order to examine associations between meniscal extrusion, knee structure, radiographic changes and risk factors for osteoarthritis (OA) in a largely non-osteoarthritic cohort. Meniscal extrusion, tibiofemoral cartilage defect score and cartilage volume, and tibial plateau bone are...

Detached Eddy Simulation on a 13 M grid is conducted for a KVLCC2 tanker hull form at drift angle 301. The objective is to identify and analyze the vortical structures, instabilities, and turbulent structures with analogy to the vortex breakdown and helical instability analysis for delta wing at large angles of attack. One shear layer, one Karman-like vortex shedding, and three helical mode ins...

We analyze two-component spatial optical vortex solitons supported by parametric wave mixing processes in a nonlinear bulk medium. We study two distinct cases of such localized waves, namely, parametric vortex solitons due to phase-matched second-harmonic generation in an optical medium with competing quadratic and cubic nonlinear response, and vortex solitons in the presence of third-harmonic ...

We propose very general vortex nucleation mechanisms[1] analogous to a hydrodynamic instability and calculate associated critical velocity in agreement with experiments. The creation of vortices via extrinsic mechanism is driven by a formation of the surface vorticity sheet created by the flow, which reaches a critical size. Such a sheet screens an attraction of a half-vortex ring to the wall, ...

We perform a theoretical study into how dipole-dipole interactions modify the properties of superfluid vortices within the context of a two-dimensional atomic Bose gas of co-oriented dipoles. The reduced density at a vortex acts like a giant antidipole, changing the density profile and generating an effective dipolar potential centred at the vortex core whose most slowly decaying terms go as 1/...

The antiapoptotic protein Bcl-2 plays important roles in Ca(2+) signaling by influencing inositol triphosphate receptors and regulating Ca(2+)-induced Ca(2+) release. Here we investigated whether Bcl-2 affects Ca(2+) extrusion in pancreatic acinar cells. We specifically blocked the Ca(2+) pumps in the endoplasmic reticulum and assessed the rate at which the cells reduced an elevated cytosolic C...

Spine Ca 2 triggers the induction of synaptic plasticity and other adaptive neuronal responses. The amplitude and time course of Ca 2 signals specify the activation of the signaling pathways that trigger different forms of plasticity such as long-term potentiation and depression. The shapes of Ca 2 signals are determined by the dynamics of Ca 2 sources, Ca 2 buffers, and Ca 2 extrusion mechanis...