Dogs given inescapable shock in a Pavlovian harness later seem to "give up" and passively accept traumatic shock in shuttlebox escape/avoidance training. A theoretical analysis of this phenomenon was presented. As predicted by this analysis, the failure to escape was alleviated by repeatedly compelling the dog to make the response which terminated shock. This maladaptive passive behavior in the...

One approach to the study of wear involves the ch~~te~zation of surface failure under conditions of single-pass sliding. Such an approach has been used to show that the wear of commercial and experimental restorative resins and composites is determined by the resistance of the material to penetration and by the mode of deformation during sliding [l] . The purpose of this investigation was to ch...

Background: It is now well established that several environmental stress factors cause activation of p38 MAP kinase and JNK in various cell types to produce chemokines. Objective: To investigate the expression of CXC chemokines Gro/KC and SDF- 1a in rat's H4 hepatoma cells in response to heat shock, hyperosmolarity and oxidative stress. Methods: Hepatoma cells were maintained in MEM medium. Cel...

The mechanical response and fracture of metal sandwich panels subjected to multiple impulsive pressure loads (shocks) were investigated for panels with honeycomb and folded plate core constructions. The structural performance of panels with specific core configurations under multiple impulsive pressure loads is quantified by the maximum transverse deflection of the face sheets and the core crus...

INTRODUCTION Excessive sympathoadrenal activation in critical illness contributes directly to organ damage, and high concentrations of catecholamines damage the vascular endothelium. This study investigated associations between potential drivers of sympathoadrenal activation, circulating catecholamines and biomarkers of endothelial damage and outcome in ST segment elevation myocardial infarctio...

This paper presents a model for deterioration and repair of a railway line. The critical failure is “broken line”. Two main failure mechanisms are considered: either shock failure, i.e. an immediate critical failure (without “warning”), or the critical failure occurs as the result of a degradation process, i.e. a degraded failure (crack) occurs first. Various types of inspection and maintenance...

The face stability of shallow tunnels was investigated with small-scale model experiments at single gravity. Aim of the research was to detect the evolution of failure mechanisms in dense and loose soil samples with varying overburden above the tunnel. Moreover, the quality of proposed theoretical/numerical approaches for the determination of a necessary support pressure pf was assessed. The re...

Over the past three years, BMW has undertaken a significant project to first investigate, then proceed with migration from its present crash simulation software to ABAQUS. This project has been motivated by a growing recognition within BMW that, in order to advance its crash simulation methods, improved robustness in the software employed, along with a greater emphasis on physically-motivated s...