Ordinary Objects and Series‐Style Answers to the Special Composition Question

The special composition question asks, roughly, under what conditions composition occurs. The common sense view is that composition only occurs among some things and that all and only ‘ordinary objects’ exist. Peter van Inwagen has marshaled a devastating argument against this view. The common sense view appears to commit one to giving what van Inwagen calls a ‘series‐style answer’ to the special composition question, but van Inwagen argues that series‐style answers are impossible because they are inconsistent with the transitivity of parthood. In what follows I answer this objection in addition to other, less troubling objections raised by van Inwagen.     

INFLUENCE OF ASSESSMENT CENTER METHODS ON ASSESSORS'RATINGS

Recently a number of authors have argued persuasively that performance ratings are influenced to a large extent by the way the rater selects, organizes, stores, and recalls information. Although the influence of the rater's cognitive processes on the obtained ratings has been considered in the job-performance evaluation literature, this issue has not been considered in the assessment center literature. The purpose of the present study was to examine how assessment center methods affect the way assessors organize and process assessment center information and affect the ratings they make. Independent groups of assessors underwent one of two methods for evaluating candidates in an assessment center. Data indicated differences in the convergent and discriminant validities and differences in the factor structures of the ratings for the two methods. The pattern of results suggested that the two methods for evaluating assessment center candidates affected the way the assessors organized the assessment center information and affected the obtained ratings. Future research should consider assessment center methods and assessors as sources of variation in assessment center ratings.     

Evidence for the involvement of brain GABA and serotonin systems in the anticonflict effects of chlordiazepoxide in rats

Using male hooded Lister rats the effects of GABAergic and serotonergic treatments alone and with chlordiazepoxide (CDP) were compared with the behavioral effects of CDP in a conditioned conflict procedure with three components; Reward, Time Out, and Conflict. CDP (2.5, 5.0, and 10.0 mg/kg ip) dose- relatedly increased punished and time out responding, but increased rewarded responding in an inversely dose-related manner. Punished responding was enhanced by chronic treatment to a rate which remained stable between 9 and 19 injections. The GABA transaminase inhibitor ethanolamine-O-sulfate (EOS), given chronically in drinking water (5.0 mg/ml), increased punished responding linearly to a high stable level after 2-3 weeks. Rewarded and time out responding were less substantially increased. CDP given with EOS dose- relatedly increased time out and punished responding substantially above the rates found with either treatment alone. The GABA antagonist picrotoxin blocked the increase in punished and time out responding found with EOS and CDP alone. The tryptophan hydroxylase inhibitor p-chlorophenylalanine (PCPA; 100 mg/kg x 3) linearly increased punished responding for the first week of treatment. CDP with PCPA selectively and significantly increased punished responding above the rates for either treatment alone, but the increases were not as substantial as those with EOS + CDP. The serotonin reuptake inhibitor Wy 25093 reduced increases in time out and punished responding under CDP, and the precursor 5-hydroxytryptophan (5-HTP) counteracted increases in punished responding under PCPA but also substantially reduced rewarded responding. These results provide evidence that both increased GABA and decreased serotonin transmission are involved in the anticonflict effects of CDP, as EOS and PCPA both mimicked and potentiated effects of CDP, while picrotoxin, Wy 25093, and 5-HTP counteracted them.(ABSTRACT TRUNCATED AT 250 WORDS)     

A LONGITUDINAL ANALYSIS OF BIOGRAPHICAL SUBGROUPS USING OWENS' DEVELOPMENTAL-INTEGRATIVE MODEL

The study examined the differential validity of 20 male and 14 female biographical subgroups in terms of 12 factor analyzed dimensions of postcollege experience. Owens' Developmental-Integrative Model hypothesizes that different subgroups of individuals with similar within-group early life experiences should exhibit significant differences (between-group) in a wide variety of life experiences. A sample of 1428 first-year college students were statistically grouped into 23 male and 15 female biodata subgroups after completing a standardized 118-item biodata form (Owens, 1968). Seven years later, a 97-item post-college experience inventory obtained scores for 484 of the original subjects on 12 factors of post-college behavior including job satisfaction, transition from college, personal and marital adjustment, and others. Significant univariate and multivariate differences were found between the biodata subgroups across the 7-year period. Implications for the validity of the D-I model are offered.     

Attenuation of Hippocampal 11beta-Hydroxysteroid Dehydrogenase Type 1 by Chronic Psychosocial Stress in the Tree Shrew

11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD-1) catalyses the interconversion of active cortisol and corticosterone with inert cortisone and 11-dehydrocorticosterone, thus regulating glucocorticoid access to intracellular receptors. In rats, chronic glucocorticoid excess or stress increases 11beta-HSD-1 in the hippocampus, producing suggestions that it may attenuate the deleterious effects of chronic glucocorticoid excess. However, 11beta-HSD-1 predominantly catalyses 11beta-reduction in the intact liver and hippocampal cells, thus regenerating active glucocorticoids from inert substrate. We studied 11beta-HSD activity in the tissues of male tree shrews following 28 days of sustained psychosocial stress or exogenous administration of cortisol. In the hippocampus, chronic psychosocial stress attenuated 11-HSD-1 activity (69 +/- 9% of control), whereas cortisol alone had no effect. In the liver, both chronic stress and cortisol administration decreased 11beta-HSD-1 activity (47 +/- 11% and 49 +/- 4% fall, resp.). Attenuation of 11beta-HSD-1 within tissues may reflect a homeostatic mechanism designed to minimise the adverse effects of prolonged stress and/or glucocorticoid excess.