Time-dependent impairment of inhibitory avoidance retention in rats by posttraining infusion of a mitogen-activated protein kinase kinase inhibitor into cortical and limbic structures

Mitogen-activated protein kinase (MAPK) is abundantly expressed in postmitotic neurons of the developed nervous system. MAPK is activated and required for induction of long-term potentiation (LTP) in the CA1 area of the hippocampus, which is blocked by the specific inhibitor of the MAPK kinase, PD 098059. Recently it was demonstrated that MAPK is activated in the hippocampus after training and is necessary for contextual fear conditioning learning. The present work tests the role of the MAPK cascade in step-down inhibitory avoidance (IA) retention. PD 098059 (50 microM) was bilaterally injected (0.5 microl/side) into the CA1 region of the dorsal hippocampus or entorhinal cortex at 0, 90, 180, or 360 min, or into the amygdala or parietal cortex at 0, 180, or 360 min after IA training in rats using a 0.4-mA foot shock. Retention testing was carried out 24 h after training. PD 098059 impaired retention when injected into the dorsal hippocampus at 180 min, but not 0, 90, and 360 min after training. When infused into the entorhinal cortex, PD 098059 was amnestic at 0 and 180 min, but not at 90 and 360 min after training. The MAPKK inhibitor also impairs IA retention when infused into the parietal cortex immediately after training, but not at 180 or 360 min. Infusions performed into amygdala were amnestic at 180 min, but not at 0 and 360 min after training. Our results suggest a time-dependent involvement of the MAPK cascade in the posttraining memory processing of IA; the time dependency is different in the hippocampus, amygdala, entorhinal cortex, or parietal cortex of rats.     

Organizational social context and psychopathology of youth in residential care: The intervening role of youth–caregiver relationship quality

Drawing on an ecological approach with multiple informants, this study investigated the mediating role of youth–caregiver relationship quality in associations between different features of residential care settings' organizational social context and youth's psychopathology. Participants were 378 youth aged between 12 and 25 years old, and 54 caregivers aged between 24 and 57 years old, from 29 generalist residential youth care settings in Portugal. Given the hierarchical structure of data, analyses were performed using multilevel modeling. Results revealed that organizational social contexts characterized by higher levels of engagement, stress, and centralization, as perceived by the caregivers, were associated with lower levels of youth's externalizing problems (e.g., aggressive behavior and delinquency), reported by the caregivers, via better youth–caregiver relationship quality, perceived by the youth in care. These findings highlight the relevance of creating an organizational social context in residential care settings that supports caregivers in establishing high-quality relationships with the youth in care, thereby promoting their mental health. This study contributes to the clarification of conflicting findings in previous studies of this field, by offering further empirical investigation of these issues.     

The Incompleteness of Theories of Games

We first state a few previously obtained results that lead to general undecidability and incompleteness theorems in axiomatized theories that range from the theory of finite sets to classical elementary analysis. Out of those results we prove several incompleteness theorems for axiomatic versions of the theory of noncooperative games with Nash equilibria; in particular, we show the existence of finite games whose equilibria cannot be proven to be computable.     

Exteroceptive control of response under delayed reinforcement

Three white rats, after 50 continuous reinforcements, were exposed successively, under dim illumination, to reinforcement delays of 1, 3, 5, 7.5, 10, 15, and 20 sec, with prolonged training at the 20-sec level. Behavior was maintained at each level, and an increase in interval was accompanied by an increase in post-reinforcement pause. Subsequently, under both 20- and 30-sec delays, the animals were tested during half of each daily session to determine the effect of introducing darkness during each delay interval. The result of this stimulus “support” was to regularize and increase response rate for each animal at both interval values.     

Collateral Reports and Cross-Informant Agreement about Adult Psychopathology in 14 Societies

To advance international mental health assessment, instruments that have been internationally validated are needed. To this end, we analyzed ratings from 14 societies on the Adult Behavior Checklist (ABCL), a collateral-report form parallel to the Adult Self-Report (ASR; Achenbach and Rescorla 2003) for ages 18 to 59. Both the ABCL and the ASR assess problems, personal strengths, and adaptive functioning. For a sample of 8322 see note below collaterals, we found strong consistency across societies regarding which ABCL problem items tended to obtain relatively low, medium, or high ratings. Most societal effect sizes (ESs) for problem scale scores were small to medium (< 13.9 %), but the ES for the ABCL Personal Strengths scale was 25 %. For most of the same participants (N = 8,302), we analyzed cross-informant agreement between self-reports on the ASR and collateral reports on the ABCL. Cross-informant correlations for problem scale scores averaged .47, with considerable societal variation. Problem score means were higher on the ASR than the ABCL in every society, but the size of the difference varied across societies. Mean item ratings on the ABCL and ASR were highly correlated within every society (mean r = .92), but within-dyad item rating agreement varied widely in every society (mean r = .39). In all societies, non-corroboration of self-reported deviance and of collateral-reported deviance was common. Overall findings indicated considerable similarity but also some important differences in collateral-reported problems and adaptive functioning across 14 societies.     

Husserl's Two Notions Of Completeness

In this paper I discuss Husserl's solution of the problem of imaginary elements in mathematics as presented in the drafts for two lectures hegave in Göttingen in 1901 and other related texts of the same period,a problem that had occupied Husserl since the beginning of 1890, whenhe was planning a never published sequel to Philosophie der Arithmetik(1891). In order to solve the problem of imaginary entities Husserl introduced,independently of Hilbert, two notions of completeness (definiteness in Husserl'sterminology) for a formal axiomatic system. I present and discuss these notionshere, establishing also parallels between Husserl's and Hilbert's notions ofcompleteness.