On the size of refutation Kripke models for some linear modal and tense logics

LetL be any modal or tense logic with the finite model property. For eachm, definer _L (m) to be the smallest numberr such that for any formulaA withm modal operators,A is provable inL if and only ifA is valid in everyL-model with at mostr worlds. Thus, the functionr _L determines the size of refutation Kripke models forL. In this paper, we will give an estimation ofr _L (m) for some linear modal and tense logicsL.     

Knowledge-based classification of ill-defined categories

In this paper, I report an exploratory study which investigated the role that prior knowledge plays in influencing classification learning. Under neutral or knowledge-imposing instructions, subjects learned to classify exemplars into categories that either were or were not linearly separable. Linearly separable categories are those categories whose members can be correctly classified based on an additive summation of weighted attribute information. Following category learning, the subjects were given transfer tests. A major finding was that knowledge facilitated the learning of linearly separable categories but interfered with the learning of not linearly separable categories. Quantitative analyses revealed that the knowledge facilitated category learning of the linearly separable categories by influencing the storage and reliance on both prototypical and exemplar information.     

Tactile Prompting and Weekly Performance Feedback for Increasing Teachers’ Behavior-Specific Praise

The school-based consultation literature includes a variety of empirically supported procedures for increasing teachers’ implementation of classroom management strategies. However, teachers may respond differently to empirically supported consultation procedures. This study used a multiple baseline design across three elementary teachers to test the effects of a tactile prompting and weekly performance feedback consultation procedure for increasing teachers’ behavior-specific praise. Additionally, this study included data for teachers’ rate of reprimands and their classrooms’ appropriately engaged behavior and disruptive behavior. Results indicated that tactile prompting and weekly performance feedback increased behavior-specific praise for all three teachers. However, a functional relation between tactile prompting and weekly performance feedback and changes in teachers’ reprimands and their classrooms’ appropriately engaged and disruptive behavior was not established. Implications for applied practice, and limitations and directions for future research are discussed.     

Maternal separation in early life impairs tumor immunity in adulthood in the F344 rat

Neonatal stress alters the hypothalamic-pituitary-adrenal (HPA) axis in rodents, such that, when these animals are exposed to stress as adults they hypersecrete corticosterone. Given that glucocorticoids are immunosuppressive, we examined the impact of maternal separation on HPA axis reactivity, natural killer (NK) cytotoxicity, and tumor growth in Fischer 344 rats following chronic restraint stress in adulthood. Pups underwent a chronic stress protocol whereby they were separated from their dams for 3 h on postnatal days 1-21. In adulthood, corticosterone responses were assessed following exposure to chronic (6 days for 10 h) restraint stress. Rats allocated to the chronic stress condition were inoculated with MADB106 tumor cells on day 4 of the restraint protocol. Blood was assessed for NK cytotoxicity on the final day of the chronic restraint protocol, and tumor colonization was assessed 3 weeks thereafter. Maternal separation impaired developmental weight gain (P < 0.05), depressed NK cytotoxicity (P < 0.05), and increased tumor colonization in the presence of chronic restraint stress in adulthood (P < 0.00 l). These findings occurred independently of circulating plasma corticosterone as only adult stress exposure potentiated corticosterone responses (P < 0.05). Our findings indicate that maternal separation and chronic stress can impair NK cytotoxicity and hence tumor immunity, but these effects are not directly mediated by perturbations in HPA axis function.     

Virtual reality goes to war: a brief review of the future of military behavioral healthcare

Numerous reports indicate that the incidence of posttraumatic stress disorder (PTSD) in returning OEF/OIF military personnel is creating a significant healthcare challenge. These findings have served to motivate research on how to better develop and disseminate evidence-based treatments for PTSD. Virtual Reality delivered exposure therapy for PTSD has been previously used with reports of positive outcomes. This article details how virtual reality applications are being designed and implemented across various points in the military deployment cycle to prevent, identify and treat combat-related PTSD in OIF/OEF Service Members and Veterans. The summarized projects in these areas have been developed at the University of Southern California Institute for Creative Technologies, a U.S. Army University Affiliated Research Center, and this paper will detail efforts to use virtual reality to deliver exposure therapy, assess PTSD and cognitive function and provide stress resilience training prior to deployment.     

Temporal Variation in Adolescent Suicide Attempts

The purpose of this study was to examine the association between adolescent suicide attempts and temporal cycles in a multiethnic population. Medical records at two hospitals in the state of Hawaii were reviewed for all adolescents (ages 12–18) admitted for suicide attempts during the years 1987–1991. Results showed 296 adolescents attempted suicide, and as hypothesized, temporal factors were associated with the attempts. A significant increase in attempts was found during the afternoon/evening and on Mondays and Tuesdays, transition points between home and school. The results are discussed and implications for delivery and temporal theory development considered.