Independent Contributions of Callous-Unemotional Behaviors and Quantitative Autistic Traits to Aggression in Early Childhood.

Objective: Callous-unemotional (CU) behaviors and quantitative autistic traits (QATs), heritable domains implicated in social development, are both associated with reduced prosocial behavior and increased aggression at their clinical extremes. However, they are hypothesized to contribute to aggression through separate mechanisms. This study tested whether CU behaviors and QATs exhibited distinct profiles of heritable influences as well as independent contributions to early childhood aggression in a general population sample with enhanced sensitivity to clarify these relationships.

An introduction to inverse probability weighting and marginal structural models: The case of environmental tobacco exposure and attention deficit/hyperactivity disorder behaviors.

Developmental scientists routinely examine how a focal predictor relates to some aspect of children's development. Although covariate adjustment is typically used to test hypotheses, propensity score-based methods, including inverse probability of treatment weighting (IPTW) and marginal structural models (MSM), can strengthen inference and answer more nuanced, developmentally relevant questions. This article provides a didactic introduction to IPTW and MSM methods and demonstrates their use for testing the impact of environmental smoke exposure (continuous treatment) from 6 to 90 months on parent-reported attention deficit hyperactivity disorder behaviors in first grade for 1,053 children (51% male, 44% Black) in the Family Life Project.

A Comparison of Three Executive Function Batteries in a Preschool-Aged Sample.

There is great interest in the development of executive function (EF) in the preschool period. Accordingly, multiple performance-based measures of EF have been developed for this age group, yet little is known about how they compare to one another. This study used a large and diverse sample of 3-to-5-year-old children ( = 846), who completed subtests of the National Institutes of Health's Toolbox Cognition Battery (NTCB), the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-IV), and the EF Touch battery.

Fluorometric Methods to Measure Bioavailable and Total Heme.

Heme b (iron protoporphyrin IX) is an essential but potentially cytotoxic cofactor, signaling molecule, and nutritional source of iron. Its importance in cell biology and metabolism is underscored by the fact that numerous diseases, including various cancers, neurodegenerative disorders, infectious diseases, anemias, and porphyrias, are associated with the dysregulation of heme synthesis, degradation, trafficking, and/or transport. Consequently, methods to measure, image, and quantify heme in cells are required to better understand the physiology and pathophysiology of heme.