Conditioned Alarm Behavior in Fathead Minnows (Pimephales promelas) Resulting from Association of Chemical Alarm Pheromone with a Nonbiological Visual Stimulus

Fathead minnows (Pimephales promelas) adopt antipredator (alarm) behavior when they detect alarm pheromone released from an injured conspecific. This is an adaptive response since alarm pheromone is generally released only in the context of a predation event. Alarm reactions may also occur in response to chemical and visual stimuli that minnows learn to associate with release of alarm pheromone. Here, we tested if fathead minnows can learn to associate a nonbiological, visual stimulus with predation risk. Minnows were simultaneously exposed to red light and conspecific alarm pheromone, inducing an alarm reaction. When retested using red light alone, small shoals of minnows displayed an antipredator response: dashing movements and disorganized swimming followed by decreased height in the water column and increased shoal cohesion. This resulted from a single-trial exposure to the combined cues and demonstrates a robust ecological mechanism by which minnows learn to recognize indicators of predation risk that may vary in space and time. However, learning to associate risk with biologically irrelevant stimuli may be an ecological liability. How minnows discern between relevant and irrelevant stimuli in nature is not known.     

Yeast and corn hydrolysates and other nutritious materials as attractants for onion and seed flies

The attractancy of enzymatic yeast hydrolysate, a corn hydrolysate, brewers' yeast, honey, ammonia,n-dipropyl disulfide, and several combinations of these treatments was tested in an onion field containing onion flies,Hylemya antiqua (Meigen) and seedcorn flies,H. platura (Meigen). Enzymatic yeast hydrolysate (concentrated powder) proved to be highly attractive to both fly species; females were more responsive than males. Brewers' yeast and corn hydrolysate were intermediately attractive, while all other treatments were only slightly or not at all attractive. Although no steps were taken to prolong release of volatiles, some of the nutritious materials remained highly attractive even after 11 days. The yeast products may, at certain times, be even more attractive than specific host volatiles. However, their activity was not constant over time and may be influenced by the stage of reproductive development of female flies.Diptera: AnthomyiidaePaper No. 9511 of the Michigan State University Agricultural Experiment Station.     

Hyperbolic decline-curve analysis using linear regression

Two rigorous techniques for hyperbolic decline-curve analysis based on the fundamental equations are investigated. The parameter estimation is made more accurate and repeatable than type curve matching if linear regression is used to extract the unknowns D_iq_i and n from the data. Maximizing the regression coefficient is the criterion used to select the correct parameter values. In application to six field examples, it is seen that the two methods do not always give identical results if there is a lot of scatter in the data.     

A validity study of the Psychological Stress Evaluator.

Assessed the Psychological Stress Evaluator (PSE) for its ability to display and detect arousal in the spoken word. 43 university students were asked to read aloud 10 words composed of random proportions of taboo and neutral words, PSE recordings of these words were then given to 2 trained and 10 untrained analysts for identification of stress patterns. Results indicate that, although the Ss rated the taboo words significantly more arousing than the neutral, the accuracy of identification of such words was no greater than chance for all analysts, regardless of training. It is concluded that the PSE may not be as effective as its manufacturers claim. Additional research appears warranted. (French summary) (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The ontogeny of right cerebral lateralization of spatial mental set.

Tested the manner in which right-hemisphere function lateralizes in childhood based on the left-hemisphere bias in visual orientation that results from inducing spatial mental set. 49 male and 49 female 5–12 yr olds identified tachistoscopically presented digits in either half field, given either verbal or spatial priming. The spatial priming even diminished the right-field advantage in the verbal condition when it was conducted in the 2nd session several days later. No evidence of progressive lateralization for the left hemisphere (verbal identification) or for the right hemisphere (spatial priming) process was found. Minor sex differences could be due to strategic factors. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Bayesian Approach to Controlling Percent Defective A Model and Application

The purpose of this paper is to develop a general model for controlling the percent defective of an ongoing production process. The model is developed in a Bayesian decision theory framework so that, using dynamic programming, optimal (least cost) control decisions can be found. An application of the model to a real world production process is described in detail. The problems of estimating the model parameters are discussed along with some approaches to overcoming the estimation problems. Finally, the optimal control policies for the real world process are presented and are shown to be straightforward and easily implemented.     

AC losses in tubular superconducting composites with anisotropic surface structure

AC losses have been measured in prototype tubular composite conductors of a design proposed for superconducting ac power transmission lines. The conductors were of 15 and 19 mm diameter, with a niobium surface layer bonded to a copper substrate either directly or via an intermediate layer of niobium-titanium alloy. At a surface current density appropriate for the working conditions of a power transmission line (40 A mm^?1) the losses measured for current flow in the axial or circumferential directions differed by up to an order of magnitude, depending on details of the surface anisotropy of each sample.For purely topological anisotropy, manifest in practice as longitudinal corrugations, circumferential currents gave the lower losses. For largely compositional anisotropy, such as longitudinal welds or strips of degraded surface material, circumferential currents gave the greater losses. These results have been interpreted in terms of the surface current distribution in each case.     

A Survey of Fault Tolerant Computer Architecture and its Evaluation

In striving to design highly reliable, highly available computers, two basic strategies have been employed: increasing the reliability throug-h advances in component technology; and designing self-repairing computers which use functional redundancy to permit correct performance (perhaps in a degraded manner) in the presence of component failures. Time has shown a fluctuation in the popularity of each strategy, based primarily on changes in technologies, applications and costs.