Responding under basic schedules of reinforcement in the crow.

Conditioned 5 crows to key-peck for food reinforcement using standard operant-conditioning apparatus and procedures. Responding under fixed-ratio, variable-interval, variable-ratio, and fixed-interval schedules of reinforcement was successfully maintained for each S with substantial schedule requirements. Terminal patterns of response under each of the schedules were similar to those displayed by other species, with the exception that crows paused longer after reinforcement, and responded more slowly under fixed-interval schedules, than pigeons usually do. Functional relationships between measures of performance and schedule requirements were quite consistent with reports on other species. (22 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Use of Photoinjection to Determine Oxide Charge Distributions and Interface Properties in MOS Structures-Invited Paper

Determination of the distribution of oxide charge and interface properties is important to an understanding of oxide charging phenomena such as that produced by irradiation. The physical mechanism dominating the voltage dependence of photoinjected currents in SiO2 is the scattering of electrons in the region of the oxide between the injecting electrode and the image force potential maximum. Since the spatial position of the potential maximum depends on the electric field resulting from space charge in the oxide as well as the field due to the applied voltage, analysis of the V-I characteristics of photoinjected currents can provide information about the spatial location of oxide charge. Presented in this paper are the results of an analysis of the effects of oxide space charge on the voltage dependence of photoinjected currents. It is shown that charge distribution in SiO2 can be nondestructively profiled over a range from about ten to several hundred angstroms from the injecting electrode. Since photoinjection V-I characteristics depend on electric field at the potential maximum in the oxide, whereas C-V characteristics depend on the field just inside the semiconductor, analysis of both characteristics permits distinction between charge in t e oxide a distance greater than about 10 ? and charge located at the interface.     

Fatigue self-management strategies and reported fatigue in international pilots

The use of strategies to manage fatigue associated with work was investigated in a sample of 253 pilots operating Air New Zealand regional and international routes. Overall, 13% of pilots responded that they experienced fatigue from their job as a pilot three times a week or more but no differences in overall fatigue levels were found by age, rank or fleet. The use of napping by pilots prior to an overnight duty was variable and 25% of pilots responded that they napped only a little of the time or not at all before such a duty. Pilots who routinely used daytime napping prior to overnight duties reported significantly lower levels of general fatigue. The use of the cockpit napping procedure was evenly split, with 52.5% of pilots reporting the use of cockpit napping over the previous 12 months. The use of the cockpit napping procedure was associated with lower levels of reported fatigue. Hypnotic medication use in the previous 2 months was reported by 19% of pilots mostly on an occasional basis. Melatonin and alternative medicine were used less frequently than hypnotics. This study highlights fatigue as a major problem for many pilots operating regional and international routes. The strategies used by international aircrew to manage fatigue are variable and provide support for the association between napping and lower reported fatigue.     

Reaction diffusion and associated nonequilibrium effects in the Au-Co system

Inerdiffusion in two-phase Au-Co couples was investigated using metallographic and elec-tron microprobe analyses. Deviations from local equilibrium at the moving α-@#@ α interface were observed. These deviations were significant for short (1 to 2 h duration) anneals and, as the annealing time increased, the interface compositions approached the equilibrium val-ues. The interdiffusion coefficients (~D) and intrinsic diffusivities (D_Au and D_Co) in the α-Au terminal solid solution at 950° and 900°C were determined.