Fluid-induced aseismic fault slip outpaces pore-fluid migration.

Earthquake swarms attributed to subsurface fluid injection are usually assumed to occur on faults destabilized by increased pore-fluid pressures. However, fluid injection could also activate aseismic slip, which might outpace pore-fluid migration and transmit earthquake-triggering stress changes beyond the fluid-pressurized region. We tested this theoretical prediction against data derived from fluid-injection experiments that activated and measured slow, aseismic slip on preexisting, shallow faults.

Self-similar slip instability on interfaces with rate- and state-dependent friction.

We examine the development of a frictional instability, with diverging sliding rate, at the interface of elastic bodies in contact. Evolution of friction is determined by a slip rate and state dependence. Following Viesca (2016 , 060202(R).

Stable and unstable development of an interfacial sliding instability.

Examining a nonlinear instability of sliding rate on a frictional interface of elastic bodies, we investigate whether laboratory-constrained frictional relations suggest universal scaling under even the simplest of configurations. We find blowup solutions by solving an equivalent, classical problem in fracture mechanics. The solutions are fixed points of a dynamical system and we show that their stability is lost by a cascade of Hopf bifurcations as a single problem parameter is increased, leading to chaotic dynamics.

Digoxin for the treatment of fetal congestive heart failure with sinus rhythm assessed by cardiovascular profile score.

Objective: To evaluate the effects of digoxin on the progression of congestive heart failure (CHF), and to determine the best predictors of perinatal death in fetuses with sinus rhythm and CHF.

Methods: This was a retrospective case series of fetuses with CHF treated with transplacental digoxin, evaluated at baseline (before treatment), weekly during treatment, and prior to death or delivery, using a 10-point cardiovascular profile score (CVPS) consisting of echocardiographic markers of cardiac dysfunction: cardiomegaly, valve insufficiency, hydrops, and abnormal venous and arterial Doppler flow profiles. Composite CVPS and component markers were compared before and after digoxin treatment by nonparametric testing and best predictors of perinatal survival assessed by regression analysis and receiver operating characteristics.