Atomic diffusion by the dumb-bell mechanism in a concentrated random bcc alloy

Matter transport by <110> dumb-bell interstitials in the bcc random alloy is considered in an analytical treatment based on linear response theory. Four different jump mechanisms of the dumb-bell are dealt with. It was found that at a low level of approximation relations can be deduced which give two of the three phenomenological coefficients in terms of the third one. (These relations are analogous to exact ones deduced for vacancy diffusion in the random alloy by Moleko, L. K., and Allnatt, A. R., 1998, Phil. Mag. A, 58, 666). Monte Carlo simulation shows that the relations are quite accurate, suggesting that they may well be exact.     

Anxiety sensitivity taxonicity: a concurrent test of cognitive vulnerability for post-traumatic stress symptomatology among young adults

This study evaluated the anxiety sensitivity taxon using the 16-item Anxiety Sensitivity Index in relation to 2 criteria relevant to post-traumatic stress disorder; post-traumatic stress disorder symptom severity as indexed by the Post-Traumatic Diagnostic Scale, and post-traumatic cognitions as indexed by the Post-Traumatic Cognitions Inventory. Taxometric analyses of data collected from 331 young adults indicated that the latent structure of anxiety sensitivity was taxonic with an estimated base-rate range of 11-12%. As predicted, an 8-item Anxiety Sensitivity Index Taxon Scale accounted for significant variance above and beyond that accounted for by negative affectivity and the full-scale Anxiety Sensitivity Index total score in terms of both criteria. Moreover, after accounting for variance explained by the full-scale Anxiety Sensitivity Index total score and negative affectivity, the sum score for the 8 Anxiety Sensitivity Index items not included in the Anxiety Sensitivity Index Taxon Scale was associated with significant variance in these same dependent measures, but the relation was in the opposite direction to that predicted by theory. These findings are discussed in terms of theoretical and clinical implications for the study of anxiety sensitivity and post-traumatic stress disorder vulnerability.     

Taking non-conceptualism back to Dharmakīrti

Some recent surveys of the modern philosophical debate over the existence of non-conceptual perceptual content have concluded that the distinction between conceptual and non-conceptual representations is largely terminological. To remedy this terminological impasse, Robert Hanna and Monima Chadha claim that non-conceptualists must defend an essentialist view of non-conceptual content, according to which perceptual states have representational content whose structure and psychological function are necessarily distinct from that of conceptual states. Hanna and Chadha additionally suggest that non-conceptualists should go “back to Kant” to find the most defensible version of an essentialist content non-conceptualism. I propose instead that non-conceptualists go back even further to the seventh-century Indian Buddhist philosopher Dharmakīrti, so that they may not only find historical precedent for an essentialist content view, but also some better arguments in its favor. This essay reconstructs Dharmakīrti's essentialist non-conceptualism about the contents of conscious sensory representations and the refined theory of conceptualization that it presupposes. In particular, I examine his arguments from the proprietary phenomenology of sensory experience, the cognitive encapsulation of sensory processing, as well as the iconic format of sensory representations, and assess the strength of these arguments relative to their modern counterparts.     

Further evaluation of morphine aversion: maintenance of a taste aversion using a low, nonaversive morphine dose

Previously, in an investigation of morphine-conditioned taste aversion (CTA), we found that limited preexposure to a low, nonaversive (non-CTA-inducing) dose of morphine (2.5 mg/kg) was as effective as preexposure to a higher, CTA-inducing dose (15 mg/kg) in blocking the formation of a subsequent morphine CTA. In the present study, we examined the capacity of this low, 2.5-mg/kg morphine dose to maintain a CTA initially induced by the 15-mg/kg dose. A standard CTA procedure was used. Results indicated that rats given three initial taste-drug pairings with 15 mg/kg morphine followed on subsequent pairing days by treatment with the low, non-CTA-inducing, 2.5-mg/kg dose continued to exhibit a strong CTA over 8 pairing days. A similar pattern was observed for animals continuing to receive taste-drug pairings with the 15-mg/kg dose. Animals receiving only one taste-drug pairing with the 15-mg/kg dose, followed on subsequent pairing days by 2.5-mg/kg conditioning, failed to show such a pattern of CTA. An intermediate CTA pattern was seen with animals conditioned with 15, 10, 5, and repeated 2.5-mg/kg doses over consecutive pairing days. These data suggest that exposure to a low dose of morphine, with no apparent CTA-inducing properties, is sufficient to maintain a previously established morphine taste aversion. Potential implications for understanding the apparent discriminative complexity of morphine's motivational properties are discussed.     

Cigarette Smoking and Panic Psychopathology

ABSTRACT— The present paper summarizes empirical evidence suggesting that smoking and panic problems often co-occur; that smoking is a risk factor for, and may serve to maintain, panic attacks and panic disorder; and that premorbid panic-specific vulnerability variables and full-blown panic problems are related to coping-oriented smoking motives and perhaps to the maintenance of smoking behavior. An integrative model is offered to stimulate further work on this topic, followed by future directions for research.     

The Repeated Name Penalty,the Overt Pronoun Penalty,and Topic in Japanese

When reading sentences with an anaphoric reference to a subject antecedent, repeated-name anaphors result in slower reading times relative to pronouns (the Repeated Name Penalty: RNP), and overt pronouns are read slower than null pronouns (the Overt Pronoun Penalty: OPP). Because in most languages previously tested, the grammatical subject is typically also the discourse topic it remains unclear whether these effects reflect anaphors’ subject-hood or their topic-hood. To address this question we conducted a self-paced reading experiment in Japanese, a language which morphologically marks both subjects and topics overtly. Our results show that both repeated-name topic-subject anaphors and repeated-name non-topic-subject anaphors exhibit the RNP and that both overt-pronoun topic-subject and overt-pronoun non-topic-subject anaphors show the OPP. However, a detailed examination of performance revealed an interaction between the anaphor topic marking, reference form, and the antecedent’s grammatical status, indicating that the effect of the antecedent’s grammatical status is strongest for null pronoun and repeated name subject anaphors and that the overt form most similar to null pronouns is the repeated name topic anaphor. We discuss the implications of these findings for theories of anaphor processing.     

Job performance over time is a function of latent trajectories and previous performance

Previous literature addressing job performance over time notes that past performance can affect future performance and that individuals often have distinct latent performance trajectories. However, no research to date has modeled these 2 aspects of job performance in tandem. Drawing on previous literature, the authors note that current performance may act as performance feedback, influencing future performance directly (i.e., autoregression), and that individuals differ in their performance trajectories due to individual-difference factors (i.e., latent trajectories). The authors demonstrate an autoregressive latent trajectory (ALT) model to show how both autoregressive and latent trajectory parameters may be incorporated in modeling job performance over time. Also discussed are the implications of the ALT model for future studies examining job performance longitudinally.     

Panic-relevant predictability preferences: a laboratory test

In the present investigation the authors evaluated the role of verbally instructed safety periods as they relate to predictability preference within a single-session challenge paradigm involving recurrent administrations of 20% carbon dioxide (CO-sub-2) enriched air. Participants included 160 nonclinical young adults (91 women, 69 men) between the ages of 18 and 59 (M=21.6 years; SD=7.23). Results indicated that equivalent levels of anxiety were experienced during predictable and unpredictable administrations of 20% CO-sub-2, yet participants preferred predictable compared with unpredictable trials, with women showing a stronger predictability preference than men. Lower anxiety was reported during known safety periods (predictable room air trials) but not during predictable compared with unpredictable administrations of 20% CO-sub-2. Findings are discussed in relation to theoretical and applied implications for the role of predictability in the nature of anxiety and its disorders.