Escape failure

In the shuttle box the acquisition of a two-way CAR was analyzed during 5 consecutive days. The rat was put in a box divided inside into two parts by a barrier with a small gate in the middle, and the animal was trained to cross the barrier under the influence of a conditioned stimulus (CS, fight flash). If it failed to respond within 5 s, it was punished with an unconditioned stimulus (US), a footshock (1 mA). If the rat failed to respond within 5 s to the US, it was classified as an escape failure (EF). One trial consisted of a 15 s intertrial interval (IR), followed by 15 s CS. The last 5 s of CS overlapped the 5 s of US. At each learning session, the number of CARs, EFs and IRs were automatically counted and evaluated by multi-way ANOVA. 

Rats (in each group 4 males and 4 females) were trained at 100 trials daily for 5 days in the shuttle box. The performance on the fifth day of training is shown in the table. CAR conditioned avoidance response EF escape failure IR intersignal reaction Significance of combination (tetrabenazine + (-)-BPAP) vs tetrabenazine (ANOVA) P < 0.05, P < 0.02, P < 0.01, P < 0.001. 

CAR conditioned avoidance response EF escape failure IR intersignal reaction Significance of (-)-BPAP vs saline was calculated according to ANOVA in all cases P > 0.05. 

Woods, D.D. 2009. Escaping failure of foresight. Safety Science, 47, 498-501. 

Cyclobutadiene escaped chemical charactenzation for more than 100 years Despite numerous attempts all synthetic efforts met with failure It became apparent not only that cyclobutadiene was not aromatic but that it was exceedingly unstable Beginning m the 1950s a variety of novel techniques succeeded m generating cyclobutadiene as a transient reactive intermediate... 

Filtration installations include wrapping the trench of a pavement-edge drain system to prevent contamination of the underdrain placement behind retaining walls and bridge abutments to prevent contamination of the sand blanket placed against the stmcture to allow dissipation of pore pressures in order to avoid failure of the stmcture as silt fences to allow surface mnoff from a site while retaining the soil suspended in the mnoff and on earth slopes beneath larger stone or other overlay materials to prevent erosion of the slope as water escapes from the interior of the slope. 

The use of appropriate instruments to monitor equipment operation and relevant process variables will detect, and provide warning of, undesirable excursions. Otherwise tliese can result in equipment failure or escape of chemicals, e.g. due to atmospheric venting, leakage or spillage. Instruments may facilitate automatic control, emergency action such as coolant or pressure relief or emergency shutdown, or the operation of water deluge systems. 

Chapter 6 was concerned, with determining the probability of various failures leading to insufficient core cooling of a nuclear reactor. This chapter describes how the accident effects are calculated as the accident progresses from radionuclide release, radionuclide migration within the plant, escape from retaining structures, atmospheric radionuclide transport and the public health effects. 

Rail accidents entailing escapes of haztu dous material happen mostly in the wake of rtiil crashes or derailments. Mechanical failures of rolling stock and faults in the rail track are frequent causes of these. Anotlier hazard of railways is fires along the track, caused bj engine or brake shoe sparks. 

Viewed in this context, the Three-Mile Island (TMI) accident was the coup de grace for an already foundering industry. In spite of the fact that the hydrogen gas bubble that accumulated in Reactor 2 did not explode, although some contaminated gas escaped and that the commissions who investigated the accident faulted human error rather than equipment failure, TMI caused (as the New York Times... 

Differential expansion must be accommodated by an expansion Joint. Gasket failure can allow tube-side fluid to escape to the atmosphere. 

The entrainment of air in lubricating oil can be brought about by operating conditions (for example, churning) and by bad design such as a return pipe that is not submerged. The air bubbles naturally rise to the surface, and if they do not burst quickly, a blanket of foam will form on the oil surface. Further air escape in thus prevented and the oil becomes aerated. Oil in this condition can have an adverse affect on the system that, in extreme cases, could lead to machine failure. The function of an anti-foam additive is to assist in the burst of air bubbles when they reach the surface of the oil. 

All mechanical doors are required by law to be capable of hand operation in the event of power failure, and doors of all types must have fastenings which can be opened from either side in case an operator is shut in the store. Targer rooms must have an escape door or breakout hatch or panel at the end remote from the doors, for use in an emergency. Door openings are frequently fitted, additionally, with plastic strip curtains or doors, to reduce infiltration when the main door is open. 

Microorganisms that escape phagocytosis in a local lesion may now be transported to the regional lymph nodes via the lymphatic vessels. If massive invasion occurs with which the resident macrophages are unable to cope, microorganisms may be transported through the thoracic duct into the bloodstream. The appearance of viable microorganisms in the bloodstream is termed bacteraemia and is indicative of an invasive infection and failure of the primary defences. 

This model was developed after pioneering experiments carried out in the USA by Overmier and Seligman (1967) who reported profound behavioural changes in dogs after their exposure to inescapable, uncontrollable stress (footshock). Subsequent work has concentrated on rats and mice, which show a similar behavioural response. This is expressed as appetite and sleep disturbance, general passivity and, on re-exposure of subjects to the stress, a failure to attempt to escape ( escape deficits ), even when this is feasible. 

During the experimental large scale continuous polymerisation of acrylic acid in aqueous solution in presence of an initiator and a moderator, failure of one of the feed pumps led to an unusually high concentration of monomer in solution. This led to runaway polymerisation which burst a glass vent line and the escaping contents ignited and led to an explosion and fire. 

If allowance is made for the fact that much of the carbohydrate formed from protein, which is oxidized in the non-diabetic, may escape metabolism by the diabetic and be excreted in the urine, the protein R. Q. for the diabetic should be 0.632 instead of the normal value of 0.802.134 The R. Q. for fat is also altered because of the failure of a complete combustion of this foodstuff, due to the attendant ketonuria. 

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