A Bell-ringing Transformer

Calcium signalling: Ringing changes to the ‘bell-shaped curve’

The stimulation of cells with agonists that activate phospholipase C, and hence increase the cytoplasmic concentration of inositol 1,4,5-trisphosphate (IP3), often produces complex intracellular Ca2+ signals, such as Ca2+ waves [1]. The key to understanding how Ca2+ waves propagate was the observation that the Ca2+ wave velocity and concentration gradient was maintained as the Ca2+ waves swept ...

Ringing the changes

Ringing Js refinements

Both the four-point and the uniform cubic B-spline refinement (i.e. subdivision) schemes double the number of vertices of a closed-loop polygonal curve P and respectively produce sequences of vertices fk and bk. The Js refinement proposed here produces vertices vk=(1–s)fk+sbk. Iterative applications of Js yield a family of curves parameterized by s. It includes the four-point curve (J0), the un...

A No-reference Metric for Perceived Ringing

A novel no-reference metric to quantify ringing annoyance in compressed images is presented. It makes use of a recently proposed method to detect regions with perceived ringing. In this paper that method is expanded with the estimation of the visibility of ringing artifacts in the detected regions. A psychovisual experiment is carried out to validate the proposed metric. Its performance is comp...

Listening for Ringing Black Holes

The gravitational radiation produced by binary black holes during their inspiral, merger, and ringdown phases is a promising candidate for detection by the first or second generation of kilometer-scale interferometric gravitational wave antennas. Waveforms for the last phase, the quasinormal ringing, are well understood. I discuss the feasibility of detection of the quasinormal ringing of a bla...