Predicting recidivism with the Psychopathy Checklist: Are factor score composites really necessary?

In two previous studies on general and violent recidivism (Walters & Heilbrun, 2010; Walters, Knight, Grann, & Dahle, 2008), the summed composite antisocial facet of the Psychopathy Checklist displayed incremental validity relative to the other 3 facets (interpersonal, affective, lifestyle), whereas the other 3 facets generally failed to demonstrate incremental validity relative to the antisocial facet. Because summed composite scores do not account for ordinal item distributions, the 6 Walters et al. (2008) samples were reanalyzed with factor score composites derived from a 4-factor confirmatory factor analysis. The results, however, showed little change from what had been obtained earlier with summed composite scores. Two additional samples not previously included in any incremental validity analyses of the Psychopathy Checklist evidenced a 3-factor structure, with the lifestyle and antisocial facets merged into a single factor. This single factor displayed incremental validity relative to the interpersonal and affective facets, but the reverse was not true regardless of whether summed composite scores or factor score composites were used. A comparison of zero-order correlations from all 8 samples revealed that the antisocial summed composite score predicted significantly better than the summed composite scores for the other 3 facets and that a superordinate factor failed to improve on the performance of either the antisocial summed composite score or the antisocial factor score composite. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A Weighted-Least-Squares Estimation Approach to Comparing Trends in Age-Adjusted Cancer Rates Across Overlapping Regions

Li and Tiwari (2008) recently developed a corrected Z-test statistic for comparing the trends in cancer age-adjusted mortality and incidence rates across overlapping geographic regions, by properly adjusting for the correlation between the slopes of the fitted simple linear regression equations. One of their key assumptions is that the error variances have unknown but common variance. However, since the age-adjusted rates are linear combinations of mortality or incidence counts, arising naturally from an underlying Poisson process, this constant variance assumption may be violated. This paper develops a weighted-least-squares based test that incorporates heteroscedastic error variances, and thus significantly extends the work of Li and Tiwari. The proposed test generally outperforms the aforementioned test through simulations and through application to the age-adjusted mortality data from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute.     

Comparing the relative fit of categorical and dimensional latent variable models using consistency tests.

A number of recent studies have used Meehl’s (1995) taxometric method to determine empirically whether one should model assessment-related constructs as categories or dimensions. The taxometric method includes multiple data-analytic procedures designed to check the consistency of results. The goal is to differentiate between strong evidence of categorical structure, strong evidence of dimensional structure, and ambiguous evidence that suggests withholding judgment. Many taxometric consistency tests have been proposed, but their use has not been operationalized and studied rigorously. What tests should be performed, how should results be combined, and what thresholds should be applied? We present an approach to consistency testing that builds on prior work demonstrating that parallel analyses of categorical and dimensional comparison data provide an accurate index of the relative fit of competing structural models. Using a large simulation study spanning a wide range of data conditions, we examine many critical elements of this approach. The results provide empirical support for what marks the first rigorous operationalization of consistency testing. We discuss and empirically illustrate guidelines for implementing this approach and suggest avenues for future research to extend the practice of consistency testing to other techniques for modeling latent variables in the realm of psychological assessment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Improving the effectiveness of computer-delivered personalized drinking feedback interventions for college students.

This study evaluated methods of enhancing college students' retention of information provided to them in a computer-delivered personalized drinking feedback intervention and whether enhanced retention reduced alcohol consumption during the two-week period following the intervention. Participants were 98 college students who reported at least one heavy drinking episode in the past two weeks. After participating in an online, personalized drinking feedback intervention, students were randomly assigned to one of three experimental conditions: 1) typical, in which they were simply sent home, 2) reading, in which they were asked to spend the next 20 minutes re-reading the feedback, and 3) recall, in which they were asked to spend the next 20 minutes writing down as much of the information from the feedback as they could remember. Two weeks following the intervention, participants completed a recall test and provided information on their alcohol use during the previous two weeks. Results indicated that participants in the reading and recall conditions retained more of the feedback information than did participants in the typical condition. In addition, participants in the reading and recall conditions reported reduced alcohol consumption in the two-week period following the intervention, compared to those in the typical condition. Information retention partially mediated the effects of the reading and recall conditions on drinking outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Genetic Programming Approach to Rainfall-Runoff Modelling

Planning for sustainable development of water resources relies crucially on the data available. Continuous hydrologic simulation based on conceptual models has proved to be the appropriate tool for studying rainfall-runoff processes and for providing necessary data. In recent years, artificial neural networks have emerged as a novel identification technique for the modelling of hydrological processes. However, they represent their knowledge in terms of a weight matrix that is not accessible to human understanding at present. This paper introduces genetic programming, which is an evolutionary computing method that provides a transparent and structured system identification, to rainfall-runoff modelling. The genetic-programming approach is applied to flow prediction for the Kirkton catchment in Scotland (U.K.). The results obtained are compared to those attained using two optimally calibrated conceptual models and an artificial neural network. Correlations identified using data-driven approaches (genetic programming and neural network) are surprising in their consistency considering the relative size of the models and the number of variables included. These results also compare favourably with the conceptual models.     

U73122 and U73343 inhibit receptor-mediated phospholipase D activation downstream of phospholipase C in CHO cells

We investigated the effects of nitric oxide (NO) donors, S-nitroso-N-acetylpenicillamine and sodium nitroprusside on basal and K+-evoked release of [3H]noradrenaline from superfused synaptosomes from the rat cerebral cortex. Both substances produced concentration-dependent increases in the release of the labeled transmitter under basal and depolarized conditions. The effects of the donors on basal release were Ca2+-independent but were not inhibited by the carrier-uptake blocker, desipramine; the effects were abolished by hemoglobin (an NO scavenger). Thirty-five minutes after stimulation with sodium nitroprusside, the synaptosomes were still responsive to KCl stimulation, indicating that the donor's effects were not caused by damage to the synaptosome membrane. The cGMP analogue, 8-bromo-cGMP, had no effect on basal release, and the enhanced release produced by sodium nitroprusside was not inhibited by the specific inhibitor of soluble guanylate cyclase, 1H-[1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one, indicating that NO's effects on basal release of the neurotransmitter are guanylate cyclase-independent. Both of the NO donors had more marked effects on release of [3H]noradrenaline during K+-stimulated depolarization. The NO-mediated increase in this case was partially antagonized by 10 microM LH-[1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one, and 8-Br-cGMP was also capable of producing concentration-dependent increases in the K+-stimulated release of the transmitter. These findings indicate that the effects of the NO donors on [3H]noradrenaline release during depolarization are partially mediated by the activation of guanylate cyclase.     

The t(5;17) variant of acute promyelocytic leukemia expresses a nucleophosmin-retinoic acid receptor fusion

The classical action of the hormone 1,25-dihydroxyvitamin D3 (VD) is the regulation of calcium metabolism. In contrast, the peptide hormone atrial natriuretic factor (ANF) is one of the few known nonclassical VD responding genes. We screened the promoter of the rat ANF gene and identified a typical VD receptor (VDR) binding site formed by a direct repeat of two hexameric core binding motifs spaced by three nucleotides, between positions -907 and -891. Like most of the DR3-type VD response elements this sequence is bound with high affinity (Kd = 0.53 nM) by a heterodimer formed by VDR and retinoid X receptor. In a heterologous promoter context one copy of this sequence mediated an about fourfold gene activation by VD and a half-maximal activation (EC50) value of 0.48 nM VD. This characterizes the identified sequence as one of the most potent VD response elements.     

Informed consent: how much information is enough?

BACKGROUND: Recent judicial decisions involving informed consent have led to some medical practitioners altering the way they obtain consent. The aim of this study was to determine the degree to which patients understood the risks associated with a surgical procedure after giving routine consent and whether providing additional detailed verbal and/or written information improved their understanding. It was further determined whether the provision of more extensive information altered patients' anxiety levels. METHODS: Patients undergoing femoral popliteal bypass or carotid surgery were randomized to obtain either routine consent only or routine consent with verbal or written or verbal and written consent. Patients undertook a pre-operative risk and complication questionnaire, a pre- and postoperative anxiety and depression evaluation and a follow-up questionnaire 6 weeks after discharge. RESULTS: Thirty-two patients were included in the trial. The comprehension questionnaire resulted in a correct percentage response of 48% for the routine information only, 59% with added verbal information, 59% with added written information and 55% with added written and verbal information. Twenty-five per cent of patients stated that they had a poor understanding of the risks and complications of the procedure. CONCLUSIONS: Additional written or verbal information did not improve a patient's understanding of risks and complications of the procedure. It also did not improve patients' perceived understanding of the operation or its complications. Patients' anxiety levels were unaltered by the increase in the information they were given. The information provided to patients should be simple, easy to understand and list any possible major complications to enable the patient to determine whether to undergo or decline a procedure.