Effects of ethanol storage and lipid and urea extraction on δ15 N and δ13 C isotope ratios in a benthic elasmobranch, the bluespotted maskray Neotrygon kuhlii.

Ethanol storage and lipid and urea extraction had no effect on bluespotted maskray Neotrygon kuhlii muscle δ13 C values whereas urea-removal and ethanol storage increased δ15 N values. Results presented here show a significant δ15 N increase post-urea removal and provide additional support for this approach in future elasmobranch stable-isotope analysis (SIA) studies. Further experimental work on other elasmobranch species is needed to assess extraction and preservation effects on stable-isotope (SI) values.

Do relational risks and protective factors moderate the linkages between childhood aggression and early psychological and school adjustment?

This investigation addressed the question of how relational stressors and supports interface with a known behavioral risk (aggression) to influence early emerging adjustment trajectories. Children's risk for aggression, as well as multiple relational risk and protective factors (i.e., stressful and supportive features of peer and teacher relationships), were assessed in a sample of 396 children and used to predict changes in psychological functioning and school adjustment from the fall of their kindergarten year to the spring of their first-grade year. Results were largely consistent with additive risk-maladjustment models; with few exceptions, relational experiences predicted adjustment beyond children's aggressive risk status. For some adjustment criteria, however, there was evidence to suggest that relational stressors or supports exacerbated or compensated for dysfunctions that were linked with aggressive behavior. Moreover, compared with early onset, the chronicity of children's aggressive risk status and relational stressors and supports bore a stronger association with changes in maladjustment. Analyses conducted by ethnic groups suggested that African American children, who were typically a minority among their European American classmates, were more likely to experience particular stressors (e.g., chronic peer rejection), and were less likely to be afforded some form of support (e.g., stable teacher-child closeness). However, the nature of the predictive linkages found between the relational risk and protective factors and later maladjustment did not differ substantially by SES or ethnicity. The importance of investigating behavioral risks in conjunction with the relational features of children's interpersonal environments is discussed.

Charting the relationship trajectories of aggressive, withdrawn, and aggressive/withdrawn children during early grade school.

The premises examined in this longitudinal investigation were that specific behavioral characteristics place children at risk for relationship maladjustment in school environments, and that multiple behavioral risks predispose children to the most severe and prolonged difficulties. Aggressive, withdrawn, and aggressive/withdrawn children were compared to normative and matched control groups on teacher and peer relationship attributes, loneliness, and social satisfaction from kindergarten (M age = 5 years, 7 months; n = 250) through grade 2 (M age = 8.1; n = 242). Children's withdrawn behavior was neither highly stable nor predictive of relational difficulties, as their trajectories resembled the norm except for initially less close and more dependent relationships with teachers. Aggressive behavior was fairly stable, and associated with early-emerging, sustained difficulties including low peer acceptance and conflictual teacher-child relationships. Aggressive/withdrawn children evidenced the most difficulty: compared to children in the normative group, they were consistently more lonely, dissatisfied, friendless, disliked, victimized, and likely to have maladaptive teacher-child relationships. Findings are discussed with respect to recent developments in two prominent literatures: children at-risk and early relationship development.