Confirming the latent structure and base rate of schizotypy: A taxometric analysis.

P. E. Meehl's (1962, 1990) model of schizotypy and the development of schizophrenia implies that the structure of liability for schizophrenia is dichotomous and that a "schizogene" determines membership in a latent class, or taxon (Meehl and R. R. Golden, 1982). The authors sought to determine the latent structure and base rate of schizotypy. They applied Meehl's (1973) MAXCOV-HITMAX taxometric analytic procedures to a subset of items from the Perceptual Aberration Scale (PAS; L. J. Chapman et al, 1978), a prominent psychometric index of schizotypy, derived from a randomly ascertained nonclinical sample (N?=?1,093). The results, in accordance with Meehl's conjectures, strongly suggest that schizotypy, as assessed by the PAS, is taxonic at the latent level with a general population taxon base rate of approximately .10. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of oxides on PIXE measurements

The presence of oxides on metallic samples used for PIXE analysis affects quantitative measurements. This effect has been calculated based on thick target analysis on layers of different compositions. The ratio of oxidized metal yield to clean metal yield is seen to depend on proton energy and on oxide thickness. Calculations are presented for oxides of Al, Si, Fe, and Cu, and applied to experimental data on Si. The method may be applied to measuring thicknesses of oxides of known stoichiometry.     

Observations on the A2 England influenza epidemic: a clinicopathological study

A clinicopathological study of the 1972-1973 A2 England influenza epidemic is presented. In fatal cases early necrosis of myofibrils was present in those patients who died within 24 hours of the onset of the influenza symptoms. At 5 days gross changes were present. These were largely resolved by the eighteenth day of illness. In 42 patients treated at home, transient ECG changes were found in 18 cases. These included ST-segment deviation, T-wave inversion, flattening of the T wave, sinus bradycardia, sinus tachycardia, nodal rhythm, and atrial fibrillation. Permanent changes were observed in one patient and in an additional patient admitted to hospital with permanent A-V block.     

Temporal contrast and the word frequency effect.

Studied the word frequency effect in recall and recognition under 3 list structures: (a) homogeneous rare or common nouns, (b) mixed alternating frequencies, and (c) mixed blocked frequencies. Exp I with 96 undergraduates found that the number of frequency contrasts within a list had a clear effect on recall and little effect on recognition. Recall of rare items was poor in a homogeneous list, equal to common items in a blocked list, and better than common items when in a list of alternating frequencies. Exp II with 48 Ss examined the reversed frequency effect of the alternating list under overt and covert rehearsal conditions across 3 trials. Under overt rehearsal there was no significant difference in number of rehearsals of rare and common items. The superior recall of rare items present on Trial 1 decreased across trials supporting a stimulus change-contrast interpretation of the effect of mixed frequency items in free recall. (French summary) (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impact of psychotherapy on the productivity of psychologists.

To investigate (a) the effects of psychotherapy on the scientific publications of American psychologists and (b) the extent to which this group had received psychotherapy, questionnaires were sent to all APA members receiving PhDs 1945-1951 to obtain information about their therapy. A number of publications was obtained from the Psychological Abstracts. There were no significant differences in number of publications between therapy and matched nontherapy control samples. Of 966 male psychologists responding, ? had received psychotherapy, with clinicians disproportionately represented. Of this ?, 13% had 3 or more therapeutic experiences. There was a high positive correlation between duration of therapy and therapy satisfaction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A filter-based evolutionary algorithm for constrained optimization

We introduce a filter-based evolutionary algorithm (FEA) for constrained optimization. The filter used by an FEA explicitly imposes the concept of dominance on a partially ordered solution set. We show that the algorithm is provably robust for both linear and nonlinear problems and constraints. FEAs use a finite pattern of mutation offsets, and our analysis is closely related to recent convergence results for pattern search methods. We discuss how properties of this pattern impact the ability of an FEA to converge to a constrained local optimum.     

Induced mood and the illusion of control.

Examined the directionality of the relationship between realism in judging personal control and depression. Depressed and elated mood states were induced transiently in 40 naturally nondepressed and 40 depressed females (Beck Depression Inventory and the Multiple Affect Adjective Check List), and the impact of these transient mood states on susceptibility to the illusion of control was assessed. Naturally nondepressed Ss gave accurate judgments of control while naturally depressed Ss showed an illusion of control and overestimated their impact on an objectively uncontrollable outcome. Mood induction groups showed predicted changes in self-reported affect and a behavioral measure of depression. These results are in contrast to those of L. B. Alloy and L. Y. Abramson (1979). An implication of the present findings may be that therapeutic interventions for depression that successfully remediate depressive symptoms may also increase depressed individuals' susceptibility to the illusion of control. (39 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transfer of fluency across repetitions and across texts.

Three experiments examined transfer of reading fluency across repeated readings of the same text and across related but different texts with a total of 102 college students. In Exp 1, it was found that a paraphrase that altered the syntactic structure of sentences but not the lexical identity of main concepts or the unfolding of the message was reprocessed as an unchanged repetition. However, when the paraphrase altered the lexical identity of main concepts, there was a loss in the repetition benefit. In Exps 2 and 3, there was transfer from a representation of 1 text to the reading of a 2nd text only if the messages were continuous. Results are discussed in terms of the influence of episodic text representations on reading fluency. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)