Father contributions to cortisol responses in infancy and toddlerhood

Abstract: The current study is one of the first prospective examinations of longitudinal associations between observed father caregiving behaviors and child cortisol reactivity and regulation in response to emotional arousal. Observations of father and mother caregiving behaviors and child cortisol levels in response to challenges at 7 months and 24 months of child age were collected. Analyses were based on a subsample of children from the Family Life Project who lived with both their biological mothers and fathers and for whom there was at least partial cortisol data (7 months: n = 717; 24 months: n = 579). At the challenge conducted at 7 months of child age, 49.0% of the sample were girls; racial composition of the sample was 25.8% African American and 74.2% European American. At the challenge conducted at 24 months of child age 49.9% of the sample were girls; racial composition was 24.7% African American and 75.3% European American. We conducted analyses across assessment points simultaneously using mixed linear modeling for repeated measures data to test for differential effects of fathering across infancy and toddlerhood. Concurrent measures of father negativity were positively associated with greater increases in child cortisol levels in response to emotion challenge at 7 months (p = .01) and with higher overall levels of cortisol at 24 months (p < .001). However, there was no evidence that father caregiving during infancy independently predicted later cortisol activity during toddlerhood

Temperature Anomalies, Radiative Forcing and ENSO

The paper investigates the linkages between temperature anomalies, radiative forcing and ENSO. By means of a new flexible trend modeling approach, we uncover a nonlinear linkage between radiative forcing and global temperature anomalies. The nonlinear trend closely tracks the low frequency evolution in temperature anomalies, also accounting for the mid-end 1990s level switch, the 1998-2013 "warming hiatus" and the current steepening in trend temperatures. Radiative forcing is also found to account for trend dynamics in the Southern Oscillation Index (SOI), therefore providing support for the view that global warming might affect natural variability oscillations such as ENSO, and therefore enhance their disruptive effects. We also document the feature of time-varying volatility of temperature anomalies and SOI, which is well described by an IGARCH process. By means of a new dynamic conditional correlation model (SP-DCC), we finally document the presence of time-varying conditional correlations relating temperature anomalies across various zones and SOI. The correlation pattern is found to be consistent with the effects of ENSO events in the Tropics and their teleconnections