Abstract:Sixty-five mothers and their 24-month-old toddlers were observed in a series of laboratory procedures designed to assess relations between maternal interactive style and emotional, behavioral and physiological regulation. Emotional regulation was assessed by examining the child's behaviors (aggression, distraction, object focus) when confronted by three emotioneliciting tasks. Behavioral regulation was measured by examining children's ability to comply to maternal requests and to inhibit behavior during a delay task. Physiological regulation was derived from children's cardiac vagal tone responses to emotionally-arousing situations. Maternal interactive style was assessed by examining mothers' strategies for child behavior management (negative controlling, positive guidance) during three mother-child tasks. Maternal behavior was related to regulation in each of the three domains. Negative maternal behavior was related to poor physiological regulation, less adaptive emotion regulation, and noncompliant behavior. Positive maternal behavior was correlated with compliance, but not with any of the physiological or emotional measures. These findings are discussed in terms of the adaptive value of self-regulation in early development, and the importance of identifying the causal relations between maternal behavior and child regulation.

Seventy-three mothers and their 18-month-old toddlers were observed in a series of laboratory procedures designed to assess relations among physiological arousal, frustration distress, emotion regulation and maternal interactive style. Physiological arousal was assessed using baseline measures of vagal tone and heart period. Distress was assessed across four separate episodes designed to elicit the intensity, frequency, duration and latency of the distress response to frustrating events. Regulation was assessed by examining the child,s behaviors (aggression, distraction, mother-orientation, constructive coping) when confronted by the four frustration tasks. Maternal interactive style was assessed by examining mothers, strategies for child behavior management (negative controlling, positive guidance, preemptive interference) during four mother-child tasks. Distress to the frustrating tasks was related to aggression/acting-out behaviors, and negatively related to the use of more adaptive strategies. Maternal interference was related to distress to the frustrating events, while maternal positive guidance was related to the use of distraction and mother-oriented regulating behaviors. These findings are discussed in terms of the adaptive value of emotion regulation in early development. Key Words: emotion regulation temperament mother-child interaction toddler frustration Article: INTRODUCTION Recent approaches to the study of individual differences in personality during infancy and early childhood have conceptualized these differences in terms of variability in temperamental reactivity and emotion regulation (Gunnar, Porter, Wolf, Rigatuso, & Larson, 1995; Rothbart & Derryberry, 1981). Variations among children can be observed in the latency, intensity, frequency, and duration of emotional reactions and in the attentional and behavioral strategies used to manage such reactions (Rothbart & Derryberry, 1981). Moreover, inherent in such approaches to temperament is the notion that the behavioral manifestations of emotion experience and emotion management have underlying physiological substrates (Calkins, Fox, & Marshall, 1996; Fox, 1989; Stifter & Fox, 1990). A number of recent studies have examined emotionality in infancy and have demonstrated that there are significant relations between temperamental reactivity and emotion regulation (Stifter & Braungart, 1995) and that these relations are reflected in physiological reactivity and regulation (

Fifty-six mothers and their 24-month-old toddlers were observed on two occasions in a series of laboratory procedures designed to assess relations between emotional functioning (emotional reactivity and emotion regulation) in an individual assessment and social behavior with a same-sex peer. Emotional reactivity was assessed using two frustration tasks designed to elicit distress. Emotional regulation was assessed by examining the child's behaviors (venting, distraction, focal-object focus, self-orientation, and mother-orientation) when confronted by the two distress-eliciting tasks. Peer play behaviors were coded for social participation and peer-directed conflict (aggressive) behavior. The results indicated that both emotional reactivity and emotion regulation were important predictors of at least two types of social behavior: conflict and cooperation. Distress to frustration, when accompanied by high venting or high focal-object focus, was significantly related to conflict with peers but not when accompanied by distraction, mother-orientation or self-focused behaviors. These findings are discussed in terms of the adaptive value of emotion regulation skills in early development, and the importance of identifying the causal relations between child regulation and early social competence.

Frequently, primary hepatocytes are used as an in vitro model for the liver in vivo. However, the culture conditions reported vary considerably, with associated variability in performance. In this study, we characterized the differentiation character of primary human hepatocytes cultured using a highly defined, serum-free two-dimensional sandwich system, one that configures hepatocytes with collagen I as the substratum together with a dilute extracellular matrix (Matrigeltrade mark) overlay combined with a defined serum-free medium containing nanomolar levels of dexamethasone. Gap junctional communication, indicated by immunochemical detection of connexin 32 protein, was markedly enhanced in hepatocytes cultured in the Matrigel sandwich configuration. Whole genome expression profiling enabled direct comparison of liver tissues to hepatocytes and to the hepatoma-derived cell lines, HepG2 and Huh7. PANTHER database analyses were used to identify biological processes that were comparatively over-represented among probe sets expressed in the in vitro systems. The robustness of the primary hepatocyte cultures was reflected by the extent of unchanged expression character when compared directly to liver, with more than 77% of the probe sets unchanged in each of the over-represented categories, representing such genes as C/EBPalpha, HNF4alpha, CYP2D6, and ABCB1. In contrast, HepG2 and Huh7 cells were unchanged from the liver tissues for fewer than 48% and 55% of these probe sets, respectively. Further, hierarchical clustering of the hepatocytes, but not the cell lines, shifted from donor-specific to treatment-specific when the probe sets were filtered to focus on phenobarbital-inducible genes, indicative of the highly differentiated nature of the hepatocytes when cultured in a highly defined two-dimensional sandwich system.

No abstract