A Pilot Study of Pharyngeal Electrical Stimulation for Orally Intubated ICU Patients with Dysphagia.

Objective: Dysphagia is a common disorder in neurological and non-neurological intensive care unit (ICU) patients and can lead to aspiration pneumonia, prolonged ventilation, and delayed extubation. Dysphagia is an independent predictor of increased mortality. In dysphagic stroke patients with tracheotomy, the use of pharyngeal electric stimulation (PES), an emerging technique to treat dysphagia, has been shown to improve airway protection and shorten time to decannulation.

Simulation of spatial systems with demographic noise.

The demographic (shot) noise in population dynamics scales with the square root of the population size. This process is very important, as it yields an absorbing state at zero field, but simulating it, especially on spatial domains, is a nontrivial task. Here, we analyze two similar methods that were suggested for simulating the corresponding Langevin equation, one by Pechenik and Levine and the other by Dornic, Chaté, and Muñoz (DCM).

Empirical analysis of vegetation dynamics and the possibility of a catastrophic desertification transition.

The process of desertification in the semi-arid climatic zone is considered by many as a catastrophic regime shift, since the positive feedback of vegetation density on growth rates yields a system that admits alternative steady states. Some support to this idea comes from the analysis of static patterns, where peaks of the vegetation density histogram were associated with these alternative states. Here we present a large-scale empirical study of vegetation dynamics, aimed at identifying and quantifying directly the effects of positive feedback.

Predicting catastrophic shifts.

Catastrophic shifts are known to pose a serious threat to ecology, and a reliable set of early warning indicators is desperately needed. However, the tools suggested so far have two problems. First, they cannot discriminate between a smooth transition and an imminent irreversible shift.

Theory of pinned fronts.

The properties of a front between two different phases in the presence of a smoothly inhomogeneous external field that takes its critical value at the crossing point is analyzed. Two generic scenarios are studied. In the first, the system admits a bistable solution and the external field governs the rate in which one phase invades the other.