Retrieval fluency inflates perceived preparation for difficult problems.

When faced with a difficult problem, people often rely on past experiences. While remembering clearly helps us reach solutions, can retrieval also lead to misperceptions of our abilities? In three experiments, participants encountered "worst case scenarios" they likely had never experienced and that would be difficult to navigate without extensive training (e.g., bitten by snake). Learning brief tips improved problem-solving performance later, but retrieval increased feelings of preparation by an even larger margin. This gap occurred regardless of whether people thought that tips came from an expert or another participant in the study, and it did not reflect mere familiarity with the problems themselves. Instead, our results suggest that the ease experienced while remembering, or retrieval fluency, inflated feelings of preparation.

How do static and dynamic risk factors work together to predict violent behaviour among offenders with an intellectual disability?

BACKGROUND: Research on risk assessment with offenders with an intellectual disability (ID) has largely focused on estimating the predictive accuracy of static or dynamic risk assessments, or a comparison of the two approaches. The aim of this study was to explore how static and dynamic risk variables may 'work together' to predict violent behaviour. METHODS: Data from 212 offenders with an ID were analysed. Risk assessment tools included one static measure (Violence Risk Appraisal Guide), and two dynamic measures (Emotional Problems Scale and the Short Dynamic Risk Scale). Six-month concurrent prediction data on violent behaviour were collected. A structured methodology was employed to explore putative relationships between static and dynamic factors. RESULTS: Static risk factors temporally preceded dynamic ones, and were shown to dominate both dynamic measures, while there was a non-zero relationship between the static and the two dynamic measures. According to Kraemer et al., these findings suggest that dynamic risk factors function as proxy risk factors for static risk. CONCLUSIONS: Dynamic and static risk factors appear to capture elements of the same underlying risk associated with violent behaviour in individuals with an ID. This is the first study to empirically explore risk interrelationships in the forensic ID field. We discuss the importance of the contribution of dynamic variables in the prediction and management of risk.

Pre- and post-fire pollutant loads in an urban fringe watershed in Southern California.

Post-fire runoff has the potential to be a large source of contaminants to downstream areas. However, the magnitude of this effect in urban fringe watersheds adjacent to large sources of airborne contaminants is not well documented. The current study investigates the impacts of wildfire on stormwater contaminant loading from the upper Arroyo Seco watershed, burned in 2009. This watershed is adjacent to the Greater Los Angeles, CA, USA area and has not burned in over 60 years. Consequently, it acts as a sink for regional urban pollutants and presents an opportunity to study the impacts of wildfire. Pre- and post-fire storm samples were collected and analyzed for basic cations, trace metals, and total suspended solids. The loss of vegetation and changes in soil properties from the fire greatly increased the magnitude of storm runoff, resulting in sediment-laden floods carrying high concentrations of particulate-bound constituents. Post-fire concentrations and loads were up to three orders of magnitude greater than pre-fire values for many trace metals, including lead and cadmium. A shift was also observed in the timing of chemical delivery, where maximum suspended sediment, trace metal, and cation concentrations coincided with, rather than preceded, peak discharge in the post-fire runoff, amplifying the fire's impacts on mass loading. The results emphasize the importance of sediment delivery as a primary mechanism for post-fire contaminant transport and suggest that traditional management practices that focus on treating only the early portion of storm runoff may be less effective following wildfire. We also advocate that watersheds impacted by regional urban pollutants have the potential to pose significant risk for downstream communities and ecosystems after fire.

Structure, fit and coherence of two circumplex assessments of personality in a population with intellectual disabilities.

BACKGROUND: Little research has been conducted investigating the way in which personality constructs relate to people with intellectual disabilities. The small amount of research that does exist suggests that underlying personality structure may be considerably different to that found in mainstream research. This hypothesis is, however, untested because so little work has been conducted with this population. METHOD: Two circumplex models, the Interpersonal Adjective Scales and the CIRCLE, were employed to explore the factor structure, coherence and fit of these models with this population. One hundred and twenty-three participants from forensic intellectual disability services were rated by staff on the assessments, although not all assessments were completed for all participants. RESULTS: The factor structures for both assessments conform broadly with a theoretical structure. Hypotheses concerning the magnitude and direction of Spearman's correlations both within and between assessments were generally confirmed. CONCLUSION: While results would support the applicability of mainstream personality assessments to this client group, cautions were expressed in relation to the source of the sample and to the method of data collection.

Emotional and behavioural problems in offenders with intellectual disability: comparative data from three forensic services.

BACKGROUND: Despite an increasing knowledge base concerning the assessment of emotional and behavioural problems in people with intellectual disabilities (ID), relatively little research has examined such problems in offenders with ID. METHODS: The study assessed 172 male offenders with ID in three service settings (high, medium-low security and community) using the Behaviour Rating Scale of the Emotional Problem Scales (EPS), with the aim of assessing differences in Externalizing and Internalizing Behaviour Problems. RESULTS: Normative information is presented on the Behaviour Rating Scale of the EPS across three levels of forensic ID care. It was found that offenders in higher secure care scored higher on sub-scales reflecting physical aggression than those in lower secure care. However, there was no difference in terms of other Externalizing Behaviour Problems, such as verbal aggression, non-compliance or hyperactivity. In addition, those offenders in higher secure care scored significantly higher on all Internalizing Behaviour Problems sub-scales, including anxiety, depression and low self-esteem. CONCLUSIONS: Implications for research and clinical practice are discussed, including the utility of the EPS as a measure of clinical need and treatment outcome.

Temporal reliability of psychological assessments for patients in a special hospital with severe personality disorder: a preliminary note.

BACKGROUND: The new programme for assessing those with dangerous and severe personality disorder relies heavily on psychological assessments of personality disorder and risk. METHODS: The temporal reliability of assessments of psychopathy (PCL-R), risk (HCR-20) and personality was assessed using the International Personality Disorder Examination (IPDE) in 15 randomly selected male prisoners in a high secure hospital carried out at intervals varying between a mean of nine and 19 months after initial assessments by a variety of assessors. RESULTS: Using the intra-class correlation coefficient the agreement varied between 0.57 (HCR-20), 0.58 (PCL-R) and 0.38-0.70 for IPDE personality disorders, with the best agreement for antisocial personality disorder (0.70). COMMENT: These levels of agreement are consistent with other recent work on temporal reliability of personality instruments but are a little too low for confidence in these measures alone in the assessment process.

Do warning lights and sirens reduce ambulance response times?

OBJECTIVE: To determine the time saving associated with lights and siren (L&S) use during emergency response in an urban EMS system. METHODS: This prospective study evaluated ambulance response times from the location at time of dispatch to the scene of an emergency in an urban area. A control group of responses using L&S was compared with an experimental group that did not use L&S. An observer was assigned to ride along with ambulance crews and record actual times for all L&S responses. At a later date, an observer and an off-duty paramedic in an identical ambulance retraced the route--at the same time of day on the same day of the week--without using L&S and recorded the travel time. Response times for the two groups were compared using paired t-test. RESULTS: The 32 responses with L&S averaged 105.8 seconds (1 minute, 46 seconds) faster than those without (95% confidence interval: 60.2 to 151.5 seconds, p = 0.0001). The time difference ranged from 425 seconds (7 minutes, 5 seconds) faster with L&S to 210 seconds (3 minutes, 30 seconds) slower with L&S. CONCLUSION: In this urban EMS system, L&S reduce ambulance response times by an average of 1 minute, 46 seconds. Although statistically significant, this time saving is likely to be clinically relevant in only a very few cases. A large-scale multicenter L&S trial may help address this issue on a national level.

Hydrogen peroxide decreases effective refractory period in the isolated heart.

Although previous investigations have concluded that reactive oxygen metabolites contribute to reperfusion arrhythmias, the experimental models employed also had a significant amount of tissue injury, which may have contributed to the observed electrophysiologic effects. We studied whether exposure of the intact heart to a reactive oxygen metabolite at doses that are not associated with histologic evidence of cell necrosis would alter myocardial refractoriness, suggesting that subtle and reversible oxidative stress could alter myocardial electrophysiologic properties and perhaps contribute to ventricular arrhythmias. Isolated rabbit hearts were perfused for 30 min with low doses of hydrogen peroxide (H2O2), either 10(-5), 5 x 10(-6), or 10(-6)-M H2O2 versus vehicle alone; followed by a 30-min washout period without H2O2. Infusion of H2O2 for 30 min decreased ventricular epicardial effective refractory period (ERP) in a dose-dependent manner compared to saline controls (delta ERP). The delta ERP versus time curves during the last 10 min of H2O2 infusion were different (p less than 0.01) for each of the three H2O2 doses. Creatine phosphokinase and reversible oxidized glutathione release occurred during 10(-5)-M H2O2 infusion, but not with lower H2O2 doses. Exposure of the intact heart to low concentrations of H2O2, in a range that caused subtle oxidative injury, decreased ventricular ERP in a dose-dependent manner. Thus, H2O2 generation could contribute to ventricular arrhythmias, even in settings of sublethal and potentially reversible oxidative injury.

Cellular immunotoxicity of amyl nitrite.

Functional deficits in lymphocyte interaction following occasional or chronic exposure to inhaled nitrites may be a potential contributing but not the etiologic factor in the acquired immunodeficiency syndrome (AIDS). We evaluated the effect of amyl nitrite vapors on mononuclear cell function and demonstrated functional deficits and structural alterations in these cells. In this closed, in vitro system, exposure of cells to amyl nitrite for up to 30 minutes did not effect cell viability. The functional deficits demonstrated were: inhibition of lymphocyte erythrocyte (E) rosette formation, a suppression of lymphocyte mitogen (phytohemagglutinin) and antigen (cytomegalovirus) transformation, a block in the S, G2 and M phases of cell cycling and diminished cell cytotoxicity to CMV infected cells. These effects on cellular function were demonstrated following 5, 10, and 15 minutes of amyl nitrite vapor exposure; some effect on all cellular functions was demonstrated at 5 minutes. The structural alterations seen on scanning and transmission electron micrographs were: reduction of filapodia, smoothing of the cell profile, cytoplasmic protrusions with pseudopod-like extensions, an increase in rough endoplasmic reticulum with swollen cisternae, alterations in size and distribution of golgi components and exocytotic vesicles in the outer membrane of the nuclear envelope. These vesicles and increased membrane proliferation suggests an effect on the membrane synthesis mechanism in these cells. These effects may be a potential factor in the alterations of phenotypic markers on T lymphocyte populations, as well as, a potential contributing factor in the functional deficit of mononuclear cells in patients with AIDS.