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There is growing interest in zebrafish as a model organism in behavioral pharmacology research. Several anxiety behaviors have been characterized in zebrafish, but the effect of anxiolytic drugs on these parameters has been scarcely studied. The purpose of this work was to assess the predictive validity of acute treatment with anxiolytic drugs on behavioral parameters of anxiety. In the first task we simultaneously observed behavior of adult zebrafish on four parameters: height in the tank, locomotion, color, and shoal cohesion. The second task was the assessment of light/dark preference for 5 min. The benzodiazepines clonazepam, bromazepam, diazepam, and a moderate dose of ethanol significantly reduced shoal cohesion. Buspirone specifically increased zebrafish exploration of higher portions of the tank. In the light/dark task, all benzodiazepines, buspirone, and ethanol increased time spent in the light compartment. After treatment with anxiolytics, fish typically spent more than 60s and rarely less than 40s in the light compartment whereas controls (n=45) spent 33.3±14.4s and always less than 60s in the light compartment. Propranolol had no clear effects in these tasks. These results suggest that light/dark preference in zebrafish is a practical, low-cost, and sensitive screening task for anxiolytic drugs. Height in the tank and shoal cohesion seem to be useful behavioral parameters in discriminating different classes of these drugs.

An extensive body of research using concurrent‐chains schedules of reinforcement has shown that choice for one of two differentially valued food‐associated stimuli is dependent upon the overall temporal context in which those stimuli are embedded. The present experiments examined whether the concurrent chains procedure was useful for the study of behavior maintained by alcohol and alcohol‐associated stimuli. In Experiment 1, rats responded on concurrent‐chains schedules with equal variable‐interval (VI) 10‐s schedules in the initial links. Across conditions, fixed‐interval schedules in the terminal links were varied to yield 1:1, 9:1, and 1:9 ratios of alcohol delivery. Initial‐link response rates reflected changes in terminal‐link schedules, with greater relative responding in the rich terminal link. In Experiment 2, terminal‐link schedules remained constant with a 9:1 ratio of alcohol delivery rates while the length of two equal duration initial‐link schedules was varied. Preference for the rich terminal link was less extreme when initial links were longer (i.e., the initial‐link effect), as has been previously reported with food reinforcers. This result suggests that the conditioned reinforcing value of an alcohol‐associated stimulus depends on the temporal context in which it is embedded. The concurrent‐chains procedure and quantitative models of concurrent chains performance may provide a useful framework within which to study how contextual variables modulate preference for drug‐associated conditioned reinforcers.

Abstract not Available.

Impulsive stress in repeated shock waves administered during extracorporeal shock-wave lithotripsy (ESWL) causes injury to kidney tissue. In a study of the mechanical input of ESWL, the effects of focused shock waves on thin planar polymeric membranes immersed in a variety of tissue-mimicking fluids have been examined. A direct mechanism of failure by shock compression and an indirect mechanism by bubble collapse have been observed. Thin membranes are easily damaged by bubble collapse. After propagating through cavitation-free acoustically heterogeneous media (liquids mixed with hollow glass spheres, and tissue) shock waves cause membranes to fail in fatigue by a shearing mechanism. As is characteristic of dynamic fatigue, the failure stress increases with strain rate, determined by the amplitude and rise time of the attenuated shock wave. Shocks with large amplitude and short rise time (i.e., in uniform media) cause no damage. Thus the inhomogeneity of tissue is likely to contribute to injury in ESWL. A definition of dose is proposed which yields a criterion for damage based on measurable shock wave properties.

One of the main uncertainties in long‐term distribution network planning is load forecasting error. This paper presents a probabilistic multistage expansion planning method to consider the load forecasting error as well as pseudo dynamic behavior of network parameters and geographical constraints. The optimal routes of MV feeders as backbone of distribution networks are obtained for both mid and long‐term case with deterministic and probabilistic modeling. The Imperialist Competitive Algorithm (ICA) is adapted for the optimal expansion planning of MV distribution network. To check and maintain the radial configuration of the MV distribution network during ICA random operators, a novel algorithm is employed. Comparative tabular and graphical results are given for deterministic and probabilistic planning. In probabilistic case the results is also represented by histogram of statistics data, mean and standard deviation of input and output variables using Monte Carlo Simulation (MCS). Based on the results it is possible to design the MV network at the presence of uncertainties more robust and flexible with respect to deterministic planning without reasonable increase in total cost. The efficiency and capability of the method is tested on a relatively large‐scale distribution network.

Abstract The accurate information of the thermal stresses and temperature in isotropic elastic solids is the key for many engineering applications. At present the classical linear coupled theory of thermoelasticity deduced with the assumptions of small temperature changes is widely used to solve the thermoelastic problems in engineering. In this paper, to describe the thermoelastic behavior in isotropic solids undergoing large temperature changes more accurately, the novel coupled models of thermoelasticity and the corresponding finite element models have been presented explicitly and validated by experimental measurement. The effect of large temperature changes on the solutions of thermoelastic problems is discussed. For the heat transfer process, if the isotropic elastic solids will expand when heated and contract when cooled and the condition d E E d T · σ i j E − δ i j 1 − 2 ν α 0 can be met in the context of small deformations, the effect of large temperature changes can be regarded as increasing the specific heat. The proposed models are applied to solve two thermoelastic problems. From the obtained numerical results, the effect of large temperature changes will increase with the amplitude of temperature change and may be considerably even when the temperature changes slowly.