Differential associations of conduct disorder, callous-unemotional traits and irritability with outcome expectations and values regarding the consequences of aggression.

BACKGROUND: Previous work has examined the association of aggression levels and callous-unemotional traits with outcome expectations and values regarding the consequences of aggression. Less work has examined the outcome expectations and values regarding the consequences of aggression of adolescents with Conduct Disorder (CD). Also, no studies have examined links between irritability (a second socio-affective trait associated with CD) and these social cognitive processes despite the core function of anger in retaliatory aggression and establishing dominance. METHOD: The current study, investigating these issues, involved 193 adolescents (typically developing [TD; N = 106], 87 cases with CD [N = 87]). Participants completed an adaptation of the Outcomes Expectations and Values Questionnaire and were assessed for CU traits and irritability via the Inventory of Callous-Unemotional traits and the Affective Reactivity Index. RESULTS: While CD was associated with atypical outcome expectations this was not seen within statistical models including CU traits and irritability. CU traits were associated with decreased expectation that aggression would result in feelings of remorse and victim suffering, as well as decreased concern that aggressive acts would result in punishment and victim suffering. Irritability was associated with increased expectations and concern that aggression would result in dominance and forced respect. CONCLUSIONS: The results suggest that CU traits and irritability, often present in youth with CD, are associated with different forms of maladaptive outcome expectations and values regarding the consequences of aggression. This suggests that the atypical social cognitive processes underlying aggressive behavior among youth exhibiting CU traits may differ from those exhibiting problems regulating anger.

Growth cessation uncouples isotopic signals in leaves and tree rings of drought-exposed oak trees.

An increase in temperature along with a decrease in summer precipitation in Central Europe will result in an increased frequency of drought events and gradually lead to a change in species composition in forest ecosystems. In the present study, young oaks (Quercus robur L. and Quercus petraea (Matt.) Liebl.) were transplanted into large mesocosms and exposed for 3 years to experimental warming and a drought treatment with yearly increasing intensities. Carbon and oxygen isotopic (δ(13)C and δ(18)O) patterns were analysed in leaf tissue and tree-ring cellulose and linked to leaf physiological measures and tree-ring growth. Warming had no effect on the isotopic patterns in leaves and tree rings, while drought increased δ(18)O and δ(13)C. Under severe drought, an unexpected isotopic pattern, with a decrease in δ(18)O, was observed in tree rings but not in leaves. This decrease in δ(18)O could not be explained by concurrent physiological analyses and is not supported by current physiological knowledge. Analysis of intra-annual tree-ring growth revealed a drought-induced growth cessation that interfered with the record of isotopic signals imprinted on recently formed leaf carbohydrates. This missing record indicates isotopic uncoupling of leaves and tree rings, which may have serious implications for the interpretation of tree-ring isotopes, particularly from trees that experienced growth-limiting stresses.

Responses of leaf nitrogen and mobile carbohydrates in different Quercus species/provenances to moderate climate changes.

Global warming and shortage of water have been evidenced in the recent past and are predicted for the future. Climate change will inevitably have considerable impact on plant physiology, growth, productivity and forest ecosystem functions. The present study determined the effects of simulated daytime air warming (+1 to 1.5 °C during the growing season), drought (-40% and -57% of mean precipitation of 728 mm during the 2007 and 2008 growing season, respectively) and their combination, on leaf nitrogen (N) and non-structural carbohydrates (NSC) of two Quercus species (Q. robur and Q. petraea) and provenances (two provenances for each species) grown in two soil types in Switzerland across two treatment years, to test the hypothesis that leaf N and NSC in the more water-sensitive species (Q. robur) and provenances (originating from water-rich locations) will more strongly respond to global warming and water deficit, compared to those in the more drought-tolerant species (Q. petraea) or provenances. No species- and provenance-specific responses in leaf N and NSC to the climate treatment were found, indicating that the results failed to support our hypothesis. The between-species variation of leaf N and NSC concentrations mainly reflected differences in biology of the two species, and the between-provenance variation of N and NSC concentrations apparently mirrored the climate of their origins. Hence, we conclude that (i) the two Quercus species studied are somewhat insensitive, due to their distribution covering a wide geographical and climate range, to moderate climate change within Switzerland, and (ii) a moderate global warming of B1 scenario (IPCC 2007) will not, or at least less, negatively affect the N and carbon physiology in Q. robur and Q. petraea.

Link between continuous stem radius changes and net ecosystem productivity of a subalpine Norway spruce forest in the Swiss Alps.

*Continuous stem radius changes (DR) include growth and water-related processes on the individual tree level. DR is assumed to provide carbon turnover information complementary to net ecosystem productivity (NEP) which integrates fluxes over the entire forest ecosystem. Here, we investigated the unexpectedly close relationship between NEP and DR and asked for causalities. *NEP (positive values indicate carbon sink) measured by eddy covariance over 11 yr was analysed at three time scales alongside automated point dendrometer DR data from a Swiss subalpine Norway spruce forest. *On annual and monthly scales, the remarkably close relationship between NEP and DR was positive, whereas on a half-hourly scale the relationship was negative. Gross primary production (GPP) had a similar explanatory power at shorter time scales, but was significantly less correlated with DR on an annual scale. *The causal explanation for the NEP-DR relationship is still fragmentary; however, it is partially attributable to the following: radial stem growth with a strong effect on monthly and annual increases in NEP and DR; frost-induced bark tissue dehydration with a parallel decrease in both measures on a monthly scale; and transpiration-induced DR shrinkage which is negatively correlated with assimilation and thus with NEP on a half-hourly scale.