CSs and USs: What's the difference?

Differences in processing representations of conditioned and unconditioned stimuli (CSs and UCSs) may result from either their temporal order in training (i.e., CSs precede UCSs) or the greater biological significance of UCSs. The CS- and UCS-preexposure effects were used to probe this question. These effects are similar except that context extinction between preexposure and training more readily attenuates the UCS- than the CS-preexposure effect. In Experiments 1, 2, and 5, context extinction following preexposure to the stimulus that later served as Event 1 in Event 1?→?Event 2 pairings alleviated the response deficit due to Event 1 preexposure if Event 1 was biologically significant. In Experiments 3 and 4, context extinction alleviated the response deficit due to Event 2 preexposure if Event 2 was biologically significant. Thus, biological significance and not temporal order determines how a representation will be processed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Overshadowing and latent inhibition counteract each other: support for the comparator hypothesis

In 4 conditioned lick suppression experiments with rats, the combined effects of latent inhibition treatment followed by overshadowing treatment were assessed as a test of the comparator hypothesis's (R.R. Miller & L.D. Matzel, 1988) explanations of overshadowing and latent inhibition. Experiments 1 and 2 confirmed the prediction of the comparator hypothesis that combined latent inhibition and overshadowing treatments attenuate the response deficit produced by either treatment alone. Furthermore, consistent with the comparator hypothesis, posttraining changes in the associative status of the putative comparator stimulus altered responding to the target conditioned stimulus (Experiment 3), and switching contexts between latent inhibition and overshadowing treatments (Experiment 4) eliminated the interaction between the latent inhibition and overshadowing treatments.     

Nonverbal communication deficits and response to performance feedback in depression.

Evaluated aspects of recent behavioral and cognitive theories of depression. Social-skill concepts were conceived as involving 2 component processes, termed receptive and expressive communication, and the ability of depressed Ss to engage in these behaviors was studied within a nonverbal communication paradigm. Three groups of 10 females—depressed, psychiatric control, and normal control—had their facial expressions videotaped while exposed to a differential classical conditioning procedure, with pictorial stimuli following 1 CS, auditory stimuli following a 2nd CS, and a neutral event following a 3rd CS. In a 2nd session, the Ss observed the videotapes of other Ss, one from each diagnostic group, and judged which type of conditioning trial the observed S was undergoing, in addition to predicting their anticipated performance prior to each set of judgments. Results indicate that the depressed Ss were the most difficult to judge correctly; this deficit did not seem to be attributable to idiosyncratic response predispositions on the part of the depressives. This finding is interpreted as consistent with P. M. Lewinsohn's (see PA, Vol 53:7587) theory. Predictions of performance did not differ significantly between groups, failing to support one aspect of A. T. Beck's (1967) theory. For all groups, changes in Ss' ratings of their anticipated performance were highly correlated with the discrepancy between predicted and actual performance on previous trials. This finding is contrary to a prediction derived from M. E. Seligman's (see record 1973-06430-001) model of depression. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Deactivation kinetics and modelling of coke removal under supercritical conditions for the example of ethylbenzene disproportionation

Deactivation kinetics and coke removal kinetics were derived from experimental studies on the disproportionation of ethylbenzene with a protonated Y-faujasite (Z-14) in a loop reactor under supercritical conditions. Derivation of the steady state kinetics of ethylbenzene disproportionation permitted determination of the catalyst activity. At small educt mole fractions of ethylbenzene, owing to the modest removal of coke the deactivation kinetics can be described by a power relationship. The rate of coke removal can be correlated with the activity and the deactivation rate of the catalyst.     

Synthesis of α, ω-dichloro polyindene and poly(isobutylene-b-indene-b-isobutylene) employing Kennedy's inifer technique

Summary Kennedy's inifer technique has been modified and used for the preparation of ,-dichloro polyindene (PInCl₂). This telechelic has subsequently been used as initiator for the cationic isobutylene polymerization in conjunction with AlEt₂-Cl coinitiator. The resulting materials have been characterized by fractionation and GPC investigations.     

Zum Angriff von Aluminiumschmelzen auf niedriglegierten Stahl

Attack of molten aluminum on low alloy steel The present paper demonstrates the iron uptake by an initially ironfree hot dip aluminizing aluminum melt during the reaction with a low alloy steel (13 CrMo 44) between 700 and 800°C. The kinetic law governing iron accumulation in the melt is determined and correlated with the microscopically investigates phenomena at the phase boundary solid/melt. It is shown that an aluminum melt in contact with iron or steel not only takes up iron up to saturation but also removes from the solid additional iron, transforming it into the Θ-phase. The content of this phase in the iron saturated melt gradually increases during the process.     

Overview of wireless personal communications

This article presents an overview of the current state of wireless communications, including relevant ongoing activities in technology development, standards, and spectrum allocation. The authors discuss cellular radio, cordless telephony, and wireless data systems. Ongoing and planned future developments are summarized. The presentation is oriented toward broad coverage rather than technical depth. However, brief discussions of the air interfaces for existing digital cellular and digital cordless systems are provided, because the air interface bears heavily on system capacity and the environments in which the system can be used, as well as on the cost and complexity of the equipment