In the framework of the complex cubic-quintic Ginzburg-Landau equation, we perform a systematic analysis of two-dimensional axisymmetric doughnut-shaped localized pulses with the inner phase field in the form of a rotating spiral. We put forward a qualitative argument which suggests that, on the contrary to the known fundamental azimuthal instability of spinning doughnut-shaped solitons in the ...

In many applications of regression discontinuity designs, the running variable used to assign treatment is only observed with error. We show that, provided (i) correctly classifies assignment and (ii) affects conditional means potential outcomes smoothly, ignoring measurement error nonetheless yields an estimate a causal interpretation: average effect for units whose equals cutoff. Possibly aft...

A 48-year-old female was complaining of attacks of upper abdominal colicky lasting for about 2–6 h. The pain was recurring every 2–3 weeks for 2 months. Abdominal computed tomography (CT) showed a solid mass with an area of cystic breakdown encroaching upon the body of the pancreas interpreted as a pancreatic lesion. Upon EUS examination, an extraluminal bowel mass with typical doughnut appeara...

Owing to its sensitivity and noninvasiveness, far-field fluorescence microscopy would be almost ideal for biological imaging if the resolution of its established variants were not limited by diffraction toDr l=ð2n sinaÞ, with l denoting the wavelength of light, n the index of refraction, and a the aperture angle of the objective lens. The first concept to overcome these limits in a fundamental ...