Quality of father-child relationships as a predictor of sleep developments during preschool years

Substantial developmental changes in sleep occur during the preschool period, but few studies have investigated the factors that forecast these developments. The aim of this study was to examine whether three aspects of father-child relationships in toddlerhood predicted individual differences in developmental patterns of change in five actigraphy-derived sleep variables during the preschool period (N = 67; sleep assessed yearly between 2 and 4 years). In a predominantly White and middle-to-higher income sample, paternal mind-mindedness and quality of father-child interactions were assessed during father-child free play at 18 months and fathers self-reported on their involvement in childrearing at age 2. Multilevel growth modeling revealed that children whose father made more mind-related comments during father-child interactions had a higher proportion of sleep taking place during nighttime as well as shorter daytime and total sleep duration at 2 years. This was, however, followed by a relative leveling off (i.e., less rapid change) of these sleep features between 2 and 4 years. Given previous studies documenting that nighttime sleep proportion increases while daytime and total sleep duration decrease during preschool years, the findings suggest that children who are exposed to more paternal mind-mindedness may reach more mature sleep patterns earlier in development.

Further evidence for the multidimensional nature of maternal sensitivity: differential links with child socioemotional functioning at preschool age

There has been increasing scholarly attention to the study of maternal sensitivity as a multidimensional construct. This report investigated the predictive value of three dimensions of sensitivity during mother-infant interactions in an effort to gain greater understanding of how specific facets of sensitivity relate to child socioemotional outcomes. Maternal cooperation/attunement (accurate interpretation of infant cues and capacity to adjust the interaction correspondingly), positivity (positive attitude toward the infant), and accessibility/availability (consistent attentiveness) were assessed observationally in 195 mothers of 1-year-old infants. Child socioemotional functioning was assessed using behavioral tasks and maternal and teacher reports when children were 4 years of age. The results revealed that maternal accessibility/availability was predictive of less externalizing behavior, more prosocial behavior (mother- and teacher-reported), and better theory of mind, while maternal positivity predicted effortful control. These results highlight the advantages of a multidimensional assessment in understanding how sensitivity predicts different developmental outcomes.

Sleep development in preschool predicts executive functioning in early elementary school

This report investigates the role of normative developments in sleep during preschool years in the prediction of child EF performance at early school age. Sleep was assessed by actigraphy at ages 2, 3, and 4, and EF with behavioral tasks when children were in Grade 2. The results revealed that children whose sleep followed expected developmental trends more rapidly showed better EF performance: a more pronounced decrease in sleep duration between ages 2 and 4 predicted better subsequent working memory, whereas a more pronounced increase in sleep efficiency was predictive of better inhibitory control performance. These findings suggest that age-related development may be a key characteristic of sleep as it relates to children's executive skills.

Kids' Outcomes And Long-term Abilities (KOALA): protocol for a prospective, longitudinal cohort study of mild traumatic brain injury in children 6 months to 6 years of age

INTRODUCTION

Mild traumatic brain injury (mTBI) is highly prevalent, especially in children under 6 years. However, little research focuses on the consequences of mTBI early in development. The objective of the Kids' Outcomes And Long-term Abilities (KOALA) study is to document the impact of early mTBI on children's motor, cognitive, social and behavioural functioning, as well as on quality of life, stress, sleep and brain integrity.

METHODS AND ANALYSES

KOALA is a prospective, multicentre, longitudinal cohort study of children aged 6 months to 6 years at the time of injury/recruitment. Children who sustain mTBI (n=150) or an orthopaedic injury (n=75) will be recruited from three paediatric emergency departments (PEDs), and compared with typically developing children (community controls, n=75). A comprehensive battery of prognostic and outcome measures will be collected in the PED, at 10 days, 1, 3 and 12 months postinjury. Biological measures, including measures of brain structure and function (magnetic resonance imaging, MRI), stress (hair cortisol), sleep (actigraphy) and genetics (saliva), will complement direct testing of function using developmental and neuropsychological measures and parent questionnaires. Group comparisons and predictive models will test the a priori hypotheses that, compared with children from the community or with orthopaedic injuries, children with mTBI will (1) display more postconcussive symptoms and exhibit poorer motor, cognitive, social and behavioural functioning; (2) show evidence of altered brain structure and function, poorer sleep and higher levels of stress hormones. A combination of child, injury, socioenvironmental and psychobiological factors are expected to predict behaviour and quality of life at 1, 3 and 12 months postinjury.

ETHICS AND DISSEMINATION

The KOALA study is approved by the Sainte-Justine University Hospital, McGill University Health Centre and University of Calgary Conjoint Health Research Ethics Boards. Parents of participants will provide written consent. Dissemination will occur through peer-reviewed journals and an integrated knowledge translation plan.

Prospective relations between sleep in preschool years and academic achievement at school entry

It is often assumed that adequate sleep is a key ingredient of children's school success. Research to date, however, suggests modest associations between child sleep and academic achievement. Adopting a developmental perspective, this report investigates the associations between age-related changes in sleep across the preschool period and academic achievement at school entry. Sleep was assessed by actigraphy at ages 2, 3 and 4 among 128 children from mostly White middle-class families, and their performance in reading and mathematics was tested in Grade 1. The results revealed that children whose sleep duration decreased more rapidly across the preschool period showed better performance in both reading and mathematics. These results suggest that age-related developments may be a key characteristic of sleep in the preschool years.

Brain-Derived Neurotrophic Factor Val66Met Polymorphism and Internalizing Behaviors after Early Mild Traumatic Brain Injury

Pediatric traumatic brain injury (TBI) can lead to adverse emotional, social, and behavioral consequences. However, outcome is difficult to predict due to significant individual variability, likely reflecting a complex interaction between injury- and child-related variables. Among these variables are genetically determined individual differences, which can modulate TBI outcome through their influence on neuroplasticity mechanisms. In this study, we examined the effect of Val66Met, a common polymorphism of the brain-derived neurotrophic factor gene known to be involved in neuroplasticity mechanisms, on behavioral symptoms of mild TBI (mTBI) sustained in early childhood. This work is part of a prospective, longitudinal cohort study of early TBI. The current sample consisted of 145 children between ages 18 and 60 months assigned to one of three participant groups: mild TBI, orthopedic injury, or typically developing children. Participants provided a saliva sample to detect the presence of the Val66Met polymorphism, and the Child Behavior Checklist was used to document the presence of behavioral symptoms at 6- and 18-months post-injury. Contrary to our initial hypothesis, at 6 months post-injury, non-carriers of the Val66Met polymorphism in the mTBI group presented significantly more internalizing symptoms (e.g., anxiety/depression and somatic complaints) than Val66Met carriers, who were similar to orthopedically injured and typically developing children. However, at 18 months post-injury, all children with mTBI presented more internalizing symptoms, independent of genotype. The results of the study provide evidence for a protective effect of the Val66Met polymorphism on internalizing behavior symptoms 6 months after early childhood mTBI.

Disentangling the Direction of Associations between Sleep and Temperament in Toddlers

OBJECTIVES/BACKGROUND

Although much research has investigated the associations between children's sleep and their temperament, the direction of these associations remains unclear, largely due to a lack of longitudinal studies with repeated assessments of both sleep and temperament. Aiming to clarify the temporal precedence of these two constructs, the current study investigated reciprocal associations between toddlers' sleep and temperament with a longitudinal design.

PARTICIPANTS

The sample consisted of 82 toddlers (39 girls) assessed twice.

METHODS

At both 2 (M = 25.23 months; SD = 1.11) and 3 years of age (M = 36.81 months; SD = 0.91), toddlers' sleep duration and quality were assessed using actigraphy and their temperament was reported by their mothers with the Toddler Behavior Assessment Questionnaire.

RESULTS

Shorter nighttime sleep duration (ß = - .28, p = .03) and lower sleep efficiency (ß = - .33, p = .01) at 2 years predicted more temperamental proneness to anger at 3 years, while greater temperamental social fear at 2 years was predictive of shorter 24-hour (ß = - .44, p = .02) and nighttime (ß = - .36, p = .04) sleep duration at 3 years. Associations between temperamental activity level and sleep variables were non-significant.

CONCLUSION

The direction of the associations between toddlers' sleep and their temperament may vary according to which dimension of temperament is considered. These findings should encourage practitioners to identify the beginning of the causal chain leading to sleep or temperamental difficulties so as to develop well-tailored intervention plans.

Socioeconomic Status in Infancy and the Developing Brain: Functional Connectivity of the Hippocampus and Amygdala

The development of the hippocampus and amygdala is particularly sensitive to environmental factors, including socioeconomic status (SES). Studies that have investigated associations between SES and brain development markers have rarely focused on connectivity. Accordingly, this longitudinal study examined whether SES in infancy (parental education and income-to-needs ratio) predicts the functional connectivity of the hippocampus and amygdala in late childhood, and in turn whether functional connectivity is associated with child socioemotional adjustment in a middle-class sample. SES indices were measured when children (n = 28) were 7 months old. When children were 10 years of age, they underwent a resting-state functional magnetic resonance imaging exam, and their school teachers completed a questionnaire assessing child socioemotional adjustment. Whole-brain regression analyses, including left and right hippocampi and amygdalae as seeds and SES indices as predictors, revealed that higher parental education predicted stronger functional connectivity between the left and right hippocampi and the right amygdala with the dorsal anterior cingulate cortex, and between the left amygdala and bilateral angular gyrus, after accounting for child age and sex. In turn, the connectivity of these regions was associated with higher child prosocial behavior. These findings contribute to the emerging literature suggesting that SES is associated with variability in the neural substrates of social abilities in children.

Persistent Changes in Child Behavior After Early Mild Traumatic Brain Injury

OBJECTIVE

To document longitudinal changes in internalizing and externalizing behavioral symptoms after mild traumatic brain injury (mTBI) sustained in early childhood (i.e., between 18 and 60 months of age).

METHODS

Participants (N = 226) were recruited to one of three groups: children with mTBI, typically developing children and orthopedic injured children. The Child Behavior Checklist was used to document the presence of internalizing and externalizing behaviors at 6, 18, and 30 months postinjury. Linear mixed-model analyses were used to examine group effects on the trajectory of internalizing and externalizing behavioral manifestations over 30 months postinjury.

RESULTS

Children who sustain mTBI during the preschool period have higher rates of internalizing and externalizing behavioral symptoms at the initial assessment time point and these symptoms persist up to 30 months postinjury. Moreover, results indicate that for up to 18 months postinjury, significantly more children with mTBI present behavioral difficulties that may require some form of clinical attention (i.e., scores in the borderline or clinical range), than do their orthopedically injured and noninjured peers.

CONCLUSIONS

Sustaining mTBI early in life may lead to long-lasting behavioral changes in young children (i.e., at least 30 months). These changes are likely the product of a complex interplay between neurological and non-neurological factors, both contributing to generating and maintaining behavioral difficulties.

miR-122 does not impact recognition of the HCV genome by innate sensors of RNA but rather protects the 5' end from the cellular pyrophosphatases, DOM3Z and DUSP11

Hepatitis C virus (HCV) recruits two molecules of the liver-specific microRNA-122 (miR-122) to the 5′ end of its genome. This interaction promotes viral RNA accumulation, but the precise mechanism(s) remain incompletely understood. Previous studies suggest that miR-122 is able to protect the HCV genome from 5′ exonucleases (Xrn1/2), but this protection is not sufficient to account for the effect of miR-122 on HCV RNA accumulation. Thus, we investigated whether miR-122 was also able to protect the viral genome from innate sensors of RNA or cellular pyrophosphatases. We found that miR-122 does not play a protective role against recognition by PKR, RIG-I-like receptors, or IFITs 1 and 5. However, we found that knockdown of both the cellular pyrophosphatases, DOM3Z and DUSP11, was able to rescue viral RNA accumulation of subgenomic replicons in the absence of miR-122. Nevertheless, pyrophosphatase knockdown increased but did not restore viral RNA accumulation of full-length HCV RNA in miR-122 knockout cells, suggesting that miR-122 likely plays an additional role(s) in the HCV life cycle, beyond 5′ end protection. Overall, our results support a model in which miR-122 stabilizes the HCV genome by shielding its 5′ terminus from cellular pyrophosphatase activity and subsequent turnover by exonucleases (Xrn1/2).

Factors contributing to parent-child interaction quality following mild traumatic brain injury in early childhood

There is emerging evidence that parent-child interactions are affected by early childhood traumatic brain injury (TBI). These findings are of functional importance when considering the high prevalence of TBI in early childhood alongside evidence that young children exposed to positive relationships with their parents early in life exhibit better social functioning concurrently and longitudinally. Given that the overall quality of parent-child interactions is the result of both parent and child emotional and behavioural dispositions, it remains unclear which parental or child-related factors contribute to the quality of interactions post-TBI. The aim of this study was to investigate the factors that contribute to the quality of parent-child interactions following early childhood TBI. The sample included 68 children (18-60 months at recruitment) with accidental, uncomplicated mild TBI (mTBI). The quality of parent-child interactions was assessed 6 months post-injury using the Mutually Responsive Orientation scale, an observational measure of the dyadic quality of parent-child exchanges. Potential contributing factors were assessed among parental factors (e.g., age, socioeconomic status, family burden, parental stress, marital satisfaction) and child-related factors (e.g., age, sex, symptoms, fatigue, adaptive/behavioural skills). Socioeconomic status, child post-concussive symptoms, and child sleep problems were found to be significant independent contributing factors to parent-child interactions six months post-injury. This study provides the first evidence that both parental and child factors relate to the quality of parent-child interactions following mTBI, thus contributing to a better understanding of the scope and complexity of factors that play a role in childrens' recovery.

Beyond sites 1 and 2, miR-122 target sites in the HCV genome have negligible contributions to HCV RNA accumulation in cell culture

Hepatitis C virus (HCV) recruits two molecules of the liver-specific microRNA-122 (miR-122) to two adjacent sites (S1 and S2) located at the 5' end of the viral RNA genome. This interaction promotes HCV RNA accumulation by stabilising the viral RNA and resulting in alteration of the secondary structure of the viral genome. In addition to S1 and S2, the HCV genome contains several other putative miR-122 binding sites, one in the IRES region, three in the NS5B coding region, and one in the 3' UTR. We investigated and compared the relative contributions of the S1, S2, IRES, NS5B (NS5B.1, 2 and 3) and 3' UTR sites on protein expression, viral RNA accumulation, and infectious particle production by mutational analysis and supplementation with compensatory mutant miR-122 molecules. We found that mutations predicted to alter miR-122 binding at the IRES and NS5B.2 sites lead to reductions in HCV core protein expression and viral RNA accumulation; with a concomitant decrease in viral particle production for the NS5B.2 mutant. However, supplementation of miR-122 molecules with compensatory mutations did not rescue these site mutants to wild-type levels, suggesting that mutation of these sequences likely disrupts an additional interaction important to the HCV life cycle, beyond direct interactions with miR-122. Thus, S1 and S2 play a predominant role in viral RNA accumulation, while miR-122 interactions with the IRES, NS5B and 3' UTR regions have negligible contributions to viral protein expression, viral RNA accumulation, and infectious particle production.

Borderline Personality Disorder in Adolescence as a Generalization of Disorganized Attachment

Several researchers point to disorganized attachment as a core feature of borderline personality disorder (BPD). However, recent studies suggest that specific internal working models (IWMs) of each parent combine to account for child outcomes and that a secure relationship with one parent can protect against the deleterious effects of an insecure relationship with the other parent. It was thus hypothesized that adolescents with BPD are more likely to be disorganized with both their parents, whereas non-clinical controls are more secure with at least one of their caregivers. Thirty-six adolescents with BPD and 30 control participants (aged 13-19) were included. Psychiatrist diagnosis was verified with the Structured Interview for DSM-IV Personality Disorders (SIDP-IV) and comorbidity was assessed using the Kiddie-SADS. Reported trauma was assessed with the Childhood Trauma Questionnaire (CTQ). Attachment IWMs of each parent were assessed with the Attachment Multiple Model Interview (AMMI), which enables separate coding for each attachment figure and in which disorganization is conceptualized as conflicting attachment strategies within a specific relationship. Results of a logistic regression analysis suggested that beyond insecure attachment, being disorganized not just with one but with both parents is particularly characteristic of adolescents with BPD. Conversely, belonging to the non-clinical group was predicted by higher security scores with the father and lower deactivation with the mother. Although higher levels of childhood abuse or neglect were reported by adolescents with BPD, the retained attachment dimensions predicted group membership over and above reported trauma. These findings have important implications for clinical intervention and highlight the protective role fathers may have.