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Investigating different types of aggression is important to facilitate a better understanding of excessive maladaptive aggression in referred youth. Using regression analysis, the authors investigated demographic, historical, diagnostic, and treatment correlates of proactive aggression and reactive aggression in a heterogeneous population (N = 323) of psychiatrically referred youths. Ratings of proactive and reactive aggression significantly correlated with more established measures of aggression. Results suggest the importance of hyperactive/impulsive behavior, disruptive behavior disorders, and self-reported hostility in youths with both reactive and proactive aggression. Substance use disorders, a family history of substance abuse, and family violence were specifically associated with proactive aggression. Younger age and a history of abuse were correlated with reactive aggression. Implications for clinical interventions and future research are discussed.

Summary1. The presence of Brucella abortus within free-ranging wildlife populations is an important conservation and management issue because of the risk of brucellosis transmission between wildlife and livestock. Predicting wildlife distributions is necessary to forecast wildlife and livestock spatial overlap and the potential for brucellosis transmission. 2. We used Global Positioning System data collected from telemetry-collared female elk Cervus elaphus to develop resource selection function (RSF) models during the brucellosis transmission risk period (the abortion and calving periods). We validated extrapolation of predictive models at two nearby elk ranges within the Greater Yellowstone Ecosystem. Additionally, we integrated extrapolated RSF maps and domestic livestock distributions to estimate the relative probability of elk and livestock commingling during the brucellosis transmission risk period. 3. The top-ranked model predicted that areas selected by elk had a lower probability of wolf Canis lupus occupancy, were privately owned and south facing, and had steeper slopes, lower road densities and higher Normalized Difference Vegetation Index (NDVI). Elk selected forests and shrublands over grasslands; however, the strength of selection decreased as snowpack increased. Elk selection for privately owned lands may lead to spatial overlap with livestock and increase the risk of elk and livestock intermingling. Furthermore, if both elk and livestock concentrate in areas of higher NDVI, increased spatial overlap may occur in these areas. 4. Predictive accuracy was highest in the study area where the model was developed. When compared to the model development area, predictive accuracy of extrapolated RSF maps was similar or better in one of the elk ranges and lower in the other elk range. 5. Synthesis and applications. Extrapolated RSF and spatial overlap maps can provide a foundation for identifying the highest risk areas of elk and livestock spatial overlap during the brucellosis transmission risk period. However, the predictive accuracy of the models is limited when applied to different areas. Site-specific models of spatial overlap would therefore be needed to provide the most accurate estimates of elk and livestock spatial overlap during the transmission risk period. The degree to which spatial overlap may lead to actual transmission risk needs to be investigated as this is not yet known and could have important implications for managing transmission risk.

Abstract. S. Creel et al. reported a negative correlation between fecal progesterone concentrations and elk : wolf ratios in greater Yellowstone elk (Cervus elaphus) herds and interpreted this correlation as evidence that pregnancy rates of elk decreased substantially in the presence of wolves (Canis lupus). Apparently, the hypothesized mechanism is that decreased forage intake reduces body condition and either results in elk failing to conceive during the autumn rut or elk losing the fetus during winter. We tested this hypothesis by comparing age-specific body condition (percentage ingesta-free body fat) and pregnancy rates for northern Yellowstone elk, one of the herds sampled by Creel et al., before (1962Creel et al., before ( -1968 and after (2000)(2001)(2002)(2003)(2004)(2005)(2006) wolf restoration using indices developed and calibrated for Rocky Mountain elk. Mean age-adjusted percentage body fat of female elk was similarly high in both periods (9.0% 6 0.9% pre-wolf; 8.9% 6 0.8% post-wolf). Estimated pregnancy rates (proportion of females that were pregnant) were 0.91 pre-wolf and 0.87 post-wolf for 4-9 year-old elk (95% CI on difference ¼ À0.15 to 0.03, P ¼ 0.46) and 0.64 pre-wolf and 0.78 post-wolf for elk .9 years old (95% CI on difference ¼ À0.01 to 0.27, P ¼ 0.06). Thus, there was little evidence in these data to support strong effects of wolf presence on elk pregnancy. We caution that multiple lines of evidence and/or strong validation should be brought to bear before relying on indirect measures of how predators affect pregnancy rates.

A single-sample, within-subject descriptive study was completed to ascertain individual subject characteristics associated with outcome for 87 youths discharged from a residential treatment facility. Two different methods of assessing outcome were also compared. Variables assessing a history of abuse and internalizing psychopathology at admission to residential care were associated with outcome. Low levels of staff agreement were found on the 2 outcome measures. Implications for acute residential care are discussed.