"Teaching about animal research in psychology": Erratum.

Reports an error in the original article by M. Domjan and J. E. Purdy (American Psychologist, 1996 [Jul], Vol 51[7], 736–737). Portions of the text were inadvertently omitted in the production process; the comment is presented in its entirety. (The following abstract of this article originally appeared in PA, Vol 83:32272.). Responds to P. F. Cunningham's (see record 83:32271) and S. D. Gosling's (see record 1995-45383-001) study of the acknowledgment of contributions of animal experimentation in leading introductory psychology textbooks. The authors agree with Gosling that the primary goal of the general psychology course is to facilitate the students' understanding of psychology and that animal research is not presented in an educationally effective fashion in general psychology textbooks. However, it is argued that students need to know not only the conclusions of research but also something about how the research was conducted. In response to Cunningham's contention that psychology instructors will have to address why research animals are kept under stressful laboratory conditions, the authors note that psychology experiments typically do not involve deadly diseases or experimental pathologies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Model of noise-grating selectivity in volume holographic recording materials by use of Monte Carlo simulations

A model describing the angular selectivity of noise gratings in volume holographic recording materials is presented. The noise grating is treated as an ensemble of superimposed, statistically distributed planar gratings. Rigorous coupled-wave analysis is used to treat reconstruction with various polarization states. The model accounts for material properties such as thickness change, absorption, and the angular distribution of scattered light within the recording medium. Results show good agreement with noise gratings that are experimentally formed in a thick cationic ring-opening photopolymer material.     

DNA mutation detection in a polymer microfluidic network using temperature gradient gel electrophoresis

A miniaturized system for DNA mutation analysis, utilizing temperature gradient gel electrophoresis (TGGE) in a polycarbonate (PC) microfluidic device, is reported. TGGE reveals the presence of sequence heterogeneity in a given heteroduplex sample by introducing a thermal denaturing gradient that results in differences between the average electrophoretic mobilities of DNA sequence variants. Bulk heater assemblies are designed and employed to externally generate temperature gradients in spatial and temporal formats along the separation channels. TGGE analyses of model mutant DNA fragments, each containing a single base substitution, are achieved using both single- and 10-channel parallel measurements in a microfluidic platform. Additionally, a comprehensive polymer microfluidic device containing an integrated microheater and sensor array is developed and demonstrated for performing spatial TGGE for DNA mutation analysis. The device consists of two PC modular substrates mechanically bonded together. One substrate is embossed with microchannels, and the other contains a tapered microheater, lithographically patterned along with an array of temperature sensors. Compared with the external heating approaches, the integrated platform provides significant reduction in power requirement and thermal response time while establishing more accurate and highly effective control of the temperature gradient for achieving improved separation resolution.     

Practicum training hours: Fact and fantasy.

Over the past five years, practicum experience has received increased attention as an important element in the sequence of training. Questions have arisen about the number of hours being counted and the activities occurring in practicum. This study examined the number of practicum hours accrued by comparing the actual number of direct service hours and total hours to an estimated length of time to complete those hours. Based on self-reports, it was estimated that graduate students spend between 2 and 7 years to accrue their practicum hours with 37.5 to 69.6% of that time in direct service. Implications for the profession, faculty, and students are provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Composite disc springs

The feasibility of replacing steel with composite materials in disc springs (or Belleville washers) is investigated. The objective was to reproduce the identical load/deflection characteristics and the maximum load capacity of the steel disc spring while achieving significant mass savings. Design equations for steel disc springs were modified for a quasi-isotropic composite lay-up. Several prototype disc springs were manufactured and tested, and compared with the performance of equivalent steel springs. The results show that accurate reproducibility of the steel spring’s load–deflection characteristics can be achieved by using composites, with a corresponding mass savings of almost 80%. Other composite disc springs of different geometries were tested so that preliminary observations of the effects of geometric features on load–deflection responses could be made. The failure mode (on overloading the composite spring) consisted of radial fracture arising from the hoop stress as predicted by theory. The results of this study indicate that composites can satisfactorily replace steel in disc springs with significant mass savings.     

Is death really the worm at the core? Converging evidence that worldview threat increases death-thought accessibility.

According to terror management theory, if the cultural worldview protects people from thoughts about death, then weakening this structure should increase death-thought accessibility (DTA). Five studies tested this DTA hypothesis. Study 1 showed that threatening Canadian participants' cultural values (vs. those of another culture) increased DTA on a word-fragment completion task. Study 2 showed that when participants could dismiss the threat, DTA remained low. Study 3 replicated the results of Study 1, but DTA was measured using a lexical decision task. Response latencies to death, negative, and neutral content were measured. Worldview threat increased DTA relative to accessibility for negative and neutral content. Study 4 showed that the DTA effect emerged independently of the arousal of anger or anxiety. Finally, Study 5 demonstrated that participants with a pro-creation (vs. pro-evolution) worldview had higher DTA after reading an anti-creation article. Discussion focused on theoretical implications and directions for further research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tuning an adaptive controller using a robust control approach

This article proposes a new technique for the tuning of a discrete adaptive controller that is designed based on Lyapunov stability concepts. The tuning is based on the minimisation of a performance index that can be calculated from a generalised eigenvalue problem (GEVP) using LMI's (Linear Matrix Inequalities). The proposed technique results in an adaptive controller with time-varying tuning gains. The solution is based on an approximation of the optimal dual adaptive control problem. The tuning technique was used to perform on-line control of a first-order system and an isothermal and a non-isothermal CSTR. The results show that the proposed approach provides better performance than an adaptive algorithm with the same structure, but with constant adaptation gains. Also, the proposed algorithm is shown to be superior to an adaptive controller based on a Recursive Least Squares (RLS) estimator during sudden changes in model parameters.     

Defect‐Mediated Polarization Switching in Ferroelectrics and Related Materials: From Mesoscopic Mechanisms to Atomistic Control

The plethora of lattice and electronic behaviors in ferroelectric and multiferroic materials and heterostructures opens vistas into novel physical phenomena including magnetoelectric coupling and ferroelectric tunneling. The development of new classes of electronic, energy‐storage, and information‐technology devices depends critically on understanding and controlling field‐induced polarization switching. Polarization reversal is controlled by defects that determine activation energy, critical switching bias, and the selection between thermodynamically equivalent polarization states in multiaxial ferroelectrics. Understanding and controlling defect functionality in ferroelectric materials is as critical to the future of oxide electronics and solid‐state electrochemistry as defects in semiconductors are for semiconductor electronics. Here, recent advances in understanding the defect‐mediated switching mechanisms, enabled by recent advances in electron and scanning probe microscopy, are discussed. The synergy between local probes and structural methods offers a pathway to decipher deterministic polarization switching mechanisms on the level of a single atomically defined defect.