Understanding cardiac alternans: A piecewise linear modeling framework

Understanding cardiac alternans: a piecewise linear modeling framework.

Cardiac alternans is a beat-to-beat alternation in action potential duration (APD) and intracellular calcium (Ca(2+)) cycling seen in cardiac myocytes under rapid pacing that is believed to be a precursor to fibrillation. The cellular mechanisms of these rhythms and the coupling between cellular Ca(2+) and voltage dynamics have been extensively studied leading to the development of a class of p...

Piecewise Linear Modeling :

The Piecewise Linear Ballistic Accumulator 1 Running head: THE PIECEWISE LINEAR BALLISTIC ACCUMULATOR A new framework for modeling decisions about changing information: The Piecewise Linear Ballistic Accumulator model

In the real world, decision making processes must be able to integrate non-stationary information that changes systematically while the decision is in progress. Although theories of decision making have traditionally been applied to paradigms with stationary information, non-stationary stimuli are now of increasing theoretical interest. We developed the piecewise linear ballistic accumulator (P...

Piecewise linear car-following modeling

We present a traffic model that extends the linear car-following model as well as the minplus traffic model (a model based on the min-plus algebra). A discrete-time car-dynamics describing the traffic on a 1-lane road without passing is interpreted as a dynamic programming equation of a stochastic optimal control problem of a Markov chain. This variational formulation permits to characterize th...

Understanding cardiac alternans: the answer lies in the Ca2+ store.

Pulsus alternans is a condition wherein the heartbeat cyclically varies between weak and strong despite a constant heart rate. It was first described many years ago in experimental conditions, but it can be observed clinically, in particular, in patients with heart failure, where the presence of alternans portends a bad outcome (reviewed in1). Typically, alternans occurs at high heart rates, bu...