Suchergebnisse

Three experiments conducted in 1997 and 1998 explored individual responses to reported fictitious international conflict involving the United States and other nations. Participants escalated the conflictual level of their responses to repeated attacks. In Experiment 1, escalation of conflict was greater in response to terrorist attacks than to military ones. In Experiment 2, after the initial attacks, men were more conflictual in responding to terrorist attacks by a democratic nation than by a nondemocratic nation, whereas the opposite pattern was found for women. In Experiment 3, participants responded with a higher level of conflict to terrorist attacks on military targets than to attacks on cultural/educational targets. Participants with greater personality dominance showed steeper escalation of conflict in their responses across successive attacks. These results are interpreted within the framework of an image theory of international relations and an expansion of the democratic peace hypothesis.

Blast-induced mild traumatic brain injury (bTBI) has become increasingly common in recent military conflicts. The mechanisms by which non-impact blast exposure results in bTBI are incompletely understood. Current small animal bTBI models predominantly utilize compressed air-driven membrane rupture as their blast wave source, while large animal models use chemical explosives. The pressure-time signature of each blast mode is unique, making it difficult to evaluate the contributions of the different components of the blast wave to bTBI when using a single blast source. We utilized a multi-mode shock tube, the McMillan blast device, capable of utilizing compressed air- and compressed helium-driven membrane rupture, and the explosives oxyhydrogen and cyclotrimethylenetrinitramine (RDX, the primary component of C-4 plastic explosives) as the driving source. At similar maximal blast overpressures, the positive pressure phase of compressed air-driven blasts was longer, and the positive impulse was greater, than those observed for shockwaves produced by other driving sources. Helium-driven shockwaves more closely resembled RDX blasts, but by displacing air created a hypoxic environment within the shock tube. Pressure-time traces from oxyhydrogen-driven shockwaves were very similar those produced by RDX, although they resulted in elevated carbon monoxide levels due to combustion of the polyethylene bag used to contain the gases within the shock tube prior to detonation. Rats exposed to compressed air-driven blasts had more pronounced vascular damage than those exposed to oxyhydrogen-driven blasts of the same peak overpressure, indicating that differences in blast wave characteristics other than peak overpressure may influence the extent of bTBI. Use of this multi-mode shock tube in small animal models will enable comparison of the extent of brain injury with the pressure-time signature produced using each blast mode, facilitating evaluation of the blast wave components contributing to bTBI.