Effects For Boys Research Articles

Involvement in Sports, Hippocampal Volume, and Depressive Symptoms in Children

BackgroundRecent studies have found that higher levels of exercise are associated with fewer symptoms of depression among young people. In addition, research suggests that exercise may modify hippocampal volume, a brain region that has been found to show reduced volume in depression. However, it is not clear whether this relationship emerges as early as preadolescence. MethodsWe examined data from a nationwide sample of 4191 children 9 to 11 years of age from the Adolescent Brain and Cognitive Development Study. The parents of the children completed the Child Behavior Checklist, providing data about the child’s depressive symptoms, and the Sports and Activities Questionnaire, which provided data about the child’s participation in 23 sports. Children also took part in a structural magnetic resonance imaging scan, providing us with measures of bilateral hippocampal volume. ResultsSports involvement interacted with sex to predict depressive symptoms, with a negative relationship found in boys only (t = −5.257, β = −.115, p < .001). Sports involvement was positively correlated with hippocampal volume in both boys and girls (t = 2.810, β = .035, p = .007). Hippocampal volume also interacted with sex to predict depressive symptoms, with a negative relationship in boys (t = −2.562, β = −.070, p = .010), and served as a partial mediator for the relationship between involvement in sports and depressive symptoms in boys. ConclusionsThese findings help illuminate a potential neural mechanism for the impact of exercise on the developing brain, and the differential effects in boys versus girls mirror findings in the animal literature. More research is needed to understand the causal relationships between these constructs.

Adolescent Girls’ Biological Sensitivity to Context: Heart Rate Reactivity Moderates the Relationship Between Peer Victimization and Internalizing Problems

The theory of biological sensitivity to context (BSC) suggests that heightened stress reactivity may reflect the potential for some children to develop negative mental health outcomes under adverse environmental conditions and gain resilience under supportive environments. This study investigated the interactive effects of heart rate (HR) reactivity on an understudied form of adverse environmental conditions in BSC models, peer victimization, on internalizing problems among 82 adolescents (44 girls and 38 boys; M age = 12.08 years). Participants were nominated by peers for internalizing problems and peer victimization. HR reactivity was assessed in response to a laboratory interpersonal stressor. For girls, peer victimization was associated with internalizing problems only if girls showed high HR reactivity; there was no effect for boys. This association was absent when girls showed low HR reactivity. Results suggest that HR reactivity serves as a marker of sensitivity to environmental influence, moderating the relationship of peer victimization to internalizing behaviors for adolescent girls.

Neuroticism is linked to microstructural left-right asymmetry of fronto-limbic fibre tracts in adolescents with opposite effects in boys and girls

Neuroticism is a fundamental personality trait that reflects a tendency to experience heightened negative affect and susceptibility to stress. Negative emotionality has been associated with fronto-limbic brain structures and connecting fibre tracts. The major fibre tracts connecting the frontal and limbic brain regions are the cingulum bundle and uncinate fasciculus. We previously found that healthy adults with higher neuroticism scores had decreased left relative to right fractional anisotropy (FA) of the cingulum. Both cingulum and uncinate fasciculus FA increases throughout childhood and into early adulthood. Since adolescence is associated with an increased incidence of anxiety and mood disorders, for which neuroticism is a known risk factor, the question arises whether the association between neuroticism and fronto-limbic white matter microstructure asymmetry is already present in children and adolescents or whether such relationship emerges during this age period. To address this question, we assessed 72 typically-developing 10-to-15 year-olds with diffusion-weighted imaging on a 3 T magnetic resonance scanner. Neuroticism was assessed with the Junior Eysenck Personality Questionnaire. FA and parallel and perpendicular diffusivity measures were extracted for cingulum, uncinate fasciculus as well as the white matter underlying the ventromedial prefrontal cortex. Higher neuroticism scores were associated with decreased left relative to right cingulum FA in boys, while in girls, higher neuroticism scores were associated with increased left relative to right cingulum and ventromedial prefrontal white matter FA, indicating that there are sex differences in the neural correlates of neuroticism. Our findings suggest that the link between neuroticism and frontal-limbic white matter microstructure asymmetry likely predates early adolescence. Future studies need to elucidate the significance of the observed sex differences in the neural correlates of neuroticism.

Sex-differential effects of diphtheria-tetanus-pertussis vaccine for the outcome of paediatric admissions? A hospital based observational study from Guinea-Bissau.

In spite of protection against the targeted infections, a large volume of observational data indicates that diphtheria-tetanus-pertussis (DTP) vaccine may have a negative impact on overall childhood mortality in low-income countries, especially in girls. In an observational study using data from Bandim Health Project's continuous registration of all admissions to the paediatric ward at the National Hospital Simão Mendes in Bissau, we investigated whether DTP was associated with higher female than male in-hospital mortality (female/male case fatality ratio (F/M CFR)) and whether the CFR comparing DTP-vaccinated and DTP-unvaccinated children differed by sex. We included children aged 6 weeks to 8 months (274 days) admitted to the paediatric ward with a vaccination card seen during admission. From May 2001 to January 2008, 4230 children aged 6 weeks to 8 months were admitted and 3450 (82%; 1997 boys, 1453 girls) presented a vaccination card. The proportion presenting a vaccination card and DTP coverage did not differ by sex. During admission, 16% (200/1250) of the girls and 13% (220/1694) of the boys who had received DTP died. The F/M CFR among the 2944 DTP-vaccinated children was 1.23 (1.03-1.46); while it was 0.95 (0.66-1.38) among the 506 children who had not received DTP. DTP-vaccinated children were older and had better socioeconomic status. Adjusted for age, BCG-vaccination, residence, and maternal education the CFR comparing DTP-vaccinated boys with DTP-unvaccinated boys was 0.84 (0.63-1.11), while the CFR comparing DTP-vaccinated girls with DTP-unvaccinated girls was 1.28 (0.90-1.83) (p = .07 for same effect in boys and girls). Among DTP-vaccinated children, female in-hospital mortality was higher than male in-hospital mortality and DTP-vaccination tended to be associated with higher mortality in girls. The data are consistent with DTP having negative effects on mortality for girls. Further studies are necessary to design the optimal vaccination programme for both sexes.

Gender differences in influences of temperament on olfactory reactivity and awareness

Children’s olfactory performance is associated with temperament but whether there is a link with olfactory reactivity and awareness is not known. In adults negative affectivity is linked to reactivity to environmental odours but it is not clear whether these associations extend to children. We aimed to investigate the effect of temperamental factors on olfactory reactivity and awareness. In so doing, we controlled for the effect of parenting styles on temperamental assessment and of verbal fluency on children’s olfactory reactivity and awareness. We hypothesised that children with a high degree of negative affectivity would show greater olfactory reactivity and awareness. 129 children (62 boys, mean age 6.83 ± 0.40 years) were interviewed about their olfactory reactivity and awareness in everyday life using the established Children’s Olfactory Behavior in Everyday Life questionnaire (COBEL). Parents assessed their child’s temperament using the 94-item short form of the Children’s Behavior Questionnaire. We found that the relationship between negative affectivity and total COBEL scores varied between the genders: there was a positive, medium to large effect in boys and a negative, small one in girls. Future studies could include behavioural observations of temperament and olfactory reactivity and awareness.

Does the Good Schools Toolkit Reduce Physical, Sexual and Emotional Violence, and Injuries, in Girls and Boys equally? A Cluster-Randomised Controlled Trial

We aimed to investigate whether the Good School Toolkit reduced emotional violence, severe physical violence, sexual violence and injuries from school staff to students, as well as emotional, physical and sexual violence between peers, in Ugandan primary schools. We performed a two-arm cluster randomised controlled trial with parallel assignment. Forty-two schools in one district were allocated to intervention (n = 21) or wait-list control (n = 21) arms in 2012. We did cross-sectional baseline and endline surveys in 2012 and 2014, and the Good School Toolkit intervention was implemented for 18 months between surveys. Analyses were by intention to treat and are adjusted for clustering within schools and for baseline school-level proportions of outcomes. The Toolkit was associated with an overall reduction in any form of violence from staff and/or peers in the past week towards both male (aOR = 0.34, 95%CI 0.22–0.53) and female students (aOR = 0.55, 95%CI 0.36–0.84). Injuries as a result of violence from school staff were also lower in male (aOR = 0.36, 95%CI 0.20–0.65) and female students (aOR = 0.51, 95%CI 0.29–0.90). Although the Toolkit seems to be effective at reducing violence in both sexes, there is some suggestion that the Toolkit may have stronger effects in boys than girls. The Toolkit is a promising intervention to reduce a wide range of different forms of violence from school staff and between peers in schools, and should be urgently considered for scale-up. Further research is needed to investigate how the intervention could engage more successfully with girls.

Does physical education influence eye-hand coordination? The Lifestyles of our Kids intervention study.

In Australian government-funded primary schools, the responsibility for physical education (PE) falls mainly on general classroom teachers, many of whom possess limited PE training. This study sought to examine the impact of specialist-taught PE on eye-hand coordination (EHC) development. In this 4-year cluster-randomized intervention, participants were 187 boys and 172 girls initially in grade 2 in 29 primary schools, where no school employed university-trained specialist PE teachers. In 13 (intervention) schools, specialist PE teachers conducted 268 PE classes (two 45-minute sessions/wk) from grade 2 to grade 6. The intervention was based on traditional PE educational objectives, including fundamental motor skills, but did not specifically focus on EHC. The remaining 16 (control) schools continued with common-practice PE taught by general classroom teachers (30-60min/wk). EHC was measured by a ball throw and wall-rebound catch test and recorded at ages 8, 10, and 12 (SD 0.3) at ends of grades 2, 4, and 6, respectively. There was steady yearly improvement of EHC in both groups, but no evidence of any intervention effect in boys (P=.88) or girls (P=.20). The introduction of specialist-taught PE during 4years of primary school did not influence EHC development. Considering evidence that classroom teachers make little contribution to PE in this jurisdiction, together with the steady progression of EHC over the 4years, other influences such as organized sport, after-school activities, natural development, and parental instruction are conceivably more influential factors in EHC development during primary school years.

Randomized Trials Comparing Inactivated Vaccine After Medium- or High-titer Measles Vaccine With Standard Titer Measles Vaccine After Inactivated Vaccine: A Meta-analysis.

Observational studies have suggested that girls have higher mortality if their most recent immunization is an inactivated vaccine rather than a live vaccine. We therefore reanalyzed 5 randomized trials of early measles vaccine (MV) in which it was possible to compare an inactivated vaccines [after medium-titer MV (MTMV) or high-titer MV (HTMV)] and a live standard titer MV (after an initial inactivated vaccine). The trials were conducted in Sudan, Senegal, The Gambia and Guinea-Bissau. The intervention group received live MTMV or HTMV from 4 to 5 months and then an inactivated vaccine from 9 to 10 months of age; the control children received inactivated vaccine/placebo from 4 to 5 months and standard titer MV from 9 to 10 months of age. We compared mortality from 9 months until end of study at 3 to 5 years of age for children who received inactivated vaccine (after MTMV or HTMV) and standard titer MV (after inactivated vaccine), respectively. The original datasets were analyzed using a Cox proportional hazards model stratified by trial. The mortality rate ratio (MRR) was 1.38 (95% confidence interval: 1.05-1.83) after an inactivated vaccine (after MTMV or HTMV) compared with a standard titer MV (after inactivated vaccine). Girls had a MRR of 1.89 (1.27-2.80), whereas there was no effect for boys, the sex-differential effect being significant (P = 0.02). Excluding measles cases did not alter these conclusions, the MRR after inactivated vaccines (after MTMV or HTMV) being 1.40 (1.06-1.86) higher overall and 1.92 (1.29-2.86) for girls. Control for variations in national immunization schedules for other vaccines did not modify these results. After 9 months of age, all children had been immunized against measles, and mortality in girls was higher when they had received inactivated vaccines (after MTMV or HTMV) rather than live standard titer MV (after an inactivated vaccine).

Infant Neurodevelopment is Affected by Prenatal Maternal Stress: The QF2011 Queensland Flood Study

Research shows that prenatal maternal stress (PNMS) negatively affects a range of infant outcomes; yet no single study has explored the effects of stress in pregnancy from a natural disaster on multiple aspects of infant neurodevelopment. This study examined the effects of flood-related stress in pregnancy on 6-month-olds' neurodevelopment and examined the moderating effects of timing of the stressor in gestation and infant sex on these outcomes. Women exposed to the 2011 Queensland (Australia) floods in pregnancy completed surveys on their flood-related objective and subjective experiences at recruitment and reported on their infants' neurodevelopment on the problem solving, communication, and personal-social scales of the Ages and Stages-III at 6months postpartum (N=115). Interaction results showed that subjective flood stress in pregnancy had significantly different effects in boys and girls, and that at high levels of stress girls had significantly lower problem solving scores than boys. Timing of the flood later in pregnancy predicted lower personal-social scores in the sample, and there was a trend (p<.10) for greater objective flood exposure to predict lower scores. PNMS had no effect on infants' communication skills. In conclusion, differential aspects of maternal flood-related stress in pregnancy influenced aspects of 6-month-olds' neurodevelopment.

Does father-child conflict mediate the association between fathers' postnatal depressive symptoms and children's adjustment problems at 7 years old?

Paternal depressive symptoms are associated with children's emotional and behavioural problems, which may be mediated by negative parenting. But there is no research on the influence of paternal depressive symptoms on children's emotion regulation and limited literature investigating fathers' parenting as a mediator in the pathway between paternal depressive symptoms and children's externalizing and internalizing problems. We aimed to investigate the mediating role of father-child conflict (at 3 years) in the association between postnatal paternal depressive symptoms (at 9 months) and children's emotional and behavioural problems (at 7 years) (aim 1). We also examined whether mediation pathways were more pronounced for boys or for girls (aim 2). Secondary data analysis was conducted on the Millennium Cohort Study, when children were 9 months, 3 years and 7 years old (n = 3520). Main study variables were measured by self-report questionnaires. Fathers completed the Rutter Scale (depressive symptoms) and the Parent-Child Relationship Questionnaire (father-child conflict), while mothers completed the Strengths and Difficulties Questionnaire and the Social Behaviour Questionnaire (child emotional and behavioural problems, emotion regulation). We used structural equation modelling to estimate direct, indirect and total effects of paternal depressive symptoms on child outcomes, mediated by father-child conflict whilst adjusting for relevant covariates (maternal depressive symptoms, child temperament, marital conflict, and socio-economic factors such as poverty indicator and fathers' education level). Multi-group and interaction analysis was then conducted to determine the differential effect by gender of the association between paternal depressive symptoms on child outcomes via father-child conflict. Father-child conflict mediated the association between paternal depressive symptoms and emotion regulation problems [standardized indirect effect (SIE) 95% confidence interval (CI) -0.03 to -0.01, p < 0.001; standardized total effect (STE) 95% CI -0.05 to -0.01, p < 0.05] (aim 1). Father-child conflict mediated a larger proportion of the effect in boys (SIE 95% CI -0.03 to -0.01, p < 0.001; STE 95% CI -0.05 to 0.00, p = 0.063) than it did in girls (SIE 95% CI -0.02 to -0.01, p < 0.001; STE 95% CI -0.04 to 0.01, p = 0.216) (aim 2). Father-child conflict may mediate the association between postnatal paternal depressive symptoms and children's emotion regulation problems. Paternal depressive symptoms and father-child conflict resolution may be potential targets in preventative interventions.

Child sex and respiratory sinus arrhythmia reactivity as moderators of the relation between internalizing symptoms and aggression.

Previous studies have examined sex differences in physiological responding, including respiratory sinus arrhythmia (RSA) reactivity in response to changing stimulus conditions involving situation specific or gender related cues, in children and adolescents. The present study examined whether RSA reactivity moderates the relation between aggression and internalizing symptoms and whether there are sex differences in this effect. Participants were 82 adolescents (M age=12.1years; 44 girls) from the general middle-school population. Peer nominations assessed aggression and internalizing symptoms, and RSA reactivity (defined as change in RSA from baseline to task) was recorded while participants anticipated and responded to an 85dB signaled white-noise burst. For girls, internalizing symptoms were associated with aggression only if girls showed low RSA reactivity from baseline to task; there was no effect for boys. This association was absent when girls showed high RSA reactivity. Thus, child sex appears to influence not only levels of physiological responding but also relations of physiological responding to comorbidity of adjustment problems.

Cardiorespiratory Fitness May Help in Protecting Against Depression Among Middle School Adolescents

PurposeCross-sectional studies demonstrate a robust association between depression, physical activity, and cardiorespiratory fitness in adolescents, but longitudinal evidence that can better parse the direction of these effects is scarce and conflicting, and no such studies in adolescents have considered the importance of fitness (as opposed to physical activity per se) for preventing depression. Therefore, the present study sought to determine if cardiorespiratory fitness in the first year of middle school (sixth grade) would protect against developing depression a year later (seventh grade), even after controlling for other risk factors (i.e., preexisting depression levels and weight status). MethodsParticipants (N = 437 with 54.9% female) were recruited from six different middle schools during their sixth-grade year and reassessed during the seventh grade. At each assessment, participants completed self-report measures of depression and fitness. Participants were also weighed and were asked to complete a shuttle-run at both points. ResultsA cross-lagged panel model indicated that cardiorespiratory fitness in the sixth grade was associated with significantly less depression by the seventh grade in girls, even after controlling for preexisting depression and weight. The effect was in the same direction for boys, but was nonsignificant. In both cases, effects were modest to small. ConclusionsCardiorespiratory fitness had a small, but significant protective effect against developing depression in middle school girls, and may have a similar but smaller effect in boys. Promotion of cardiorespiratory fitness can be an important strategy for preventing depression in middle school adolescents, but needs to be coupled with interventions that more directly address symptom treatment.

Mathematics and Gender: Heterogeneity in Causes and Consequences

We exploit an institutional reduction in the costs of acquiring advanced high school mathematics to assess the causes and consequences of fewer girls choosing advanced mathematics. Girls at the top and boys at the middle of the mathematics ability distribution took more mathematics because of the cost reduction. We estimate a positive average earnings effect encompassing girls completing more advanced and more mathematics intensive college degrees, choosing more competitive careers and climbing higher up the corporate hierarchy. Encouraging more students to opt for advanced mathematics has a sizeable positive earnings effect for girls, but no effect for boys at the margin.

Family background and educational attainment - Are there birth order effects in Germany? (replication data)

This paper contributes to the literature on the determinants of children’s human capital by analyzing the effects of birth order in Germany. These effects are typically attributed to sibling rivalry for parental resources. For our analysis we use data collected as part of the German Life History Study on birth cohorts 1946–1977. We find a substantial positive impact of being first born on the probability of completing higher secondary education. Analyzing gender differences, we find stronger effects for boys. Furthermore, birth order effects are more prevailing in small families. The results are discussed against the background of equal opportunities in the German educational system.

Is Foot Asymmetry a Correlate of Hand Performance Asymmetry? Evidence from the Jamaican Symmetry Project

Handedness is likely to be controlled by many genetic variants, some of which are in sex-dependent genes that also influence body asymmetry. One such asymmetry may be in foot length. Levy and Levy (Science, 200, 1291–1292, 1978) reported that right-handed males have longer right feet than left and left-handed males have longer left feet than right, while this trend was found to be reversed in females. Subsequent studies, however, were unable to replicate this effect. Here, we consider the relationship between foot asymmetry and asymmetry of hand performance in a sample of 251 children from the Jamaican rural countryside. Foot length was measured and asymmetry was calculated (L–R). An Annett peg test was used to measure speed of hand performance for right and left hands. Lateralised hand performance (LHP) was calculated by dividing the right-hand time by the left-hand time (i.e. LHP <1 = faster right hands). For boys, L–R foot length asymmetry was positively correlated to right-hand times and to LHP, and the relationships were independent of age. It is notable that the larger the relative size of the right foot, the faster the speed of the right hand, but so also the smaller the relative size of the right foot, the slower the speed of the right hand—the distribution is continuous and significant. In girls, foot length asymmetry did not correlate with hand speed. Thus, we have replicated the Levy and Levy effect in boys, but not girls. We discuss these results in relationship to the influence of sex-dependent genes and foetal sex steroids on brain and body lateralisation.

Mealtime exposure to food advertisements while watching television increases food intake in overweight and obese girls but has a paradoxical effect in boys.

Food advertisements (ads) in TV programs influence food choice and have been associated with higher energy intake from snacks in children; however, their effects at mealtime have not been reported. Therefore, we measured energy intake at a pizza meal consumed by normal weight (NW) and overweight/obese (OW/OB) children (aged 9-14 years) while they watched a TV program with or without food ads and following pre-meal consumption of a sweetened beverage with or without calories. NW and OW/OB boys (experiment 1, n = 27) and girls (experiment 2, n = 23) were randomly assigned to consume equally sweetened drinks containing glucose (1.0 g/kg body weight) or sucralose (control). Food intake was measured 30 min later while children watched a program containing food or nonfood ads. Appetite was measured before (0-30 min) and after (60 min) the meal. Both boys and girls reduced energy intake at the meal in compensation for energy in the glucose beverage (p < 0.05). Food ads resulted in further compensation (51%) in boys but not in girls. Food ads increased energy intake at the meal (9%; p = 0.03) in OW/OB girls only. In conclusion, the effects of TV programs with food ads on mealtime energy intake and response to pre-meal energy consumption in children differ by sex and body mass index.

Friendship selection and influence in bullying and defending: effects of moral disengagement.

The current study examined the development of bullying and defending over a 1-year period as related to friends' influence and individual and friends' moral disengagement (i.e., self-justification mechanisms that allow one to avoid moral self-censure of transgressive actions) in children and young adolescents. Via longitudinal social network analysis (RSiena), it was tested whether similarity between friends in bullying and defending developed over time due to friends' influence, while controlling for friendship selection processes, and whether there were differences in these processes between children (age 9-10 years; n = 133; 42.9% girls) and young adolescents (age 11-14 years; n = 236; 40.6% girls). Results showed that individuals selected peers as friends who were similar in bullying and became more similar to friends in bullying over time, but only in early adolescence. Moreover, there was marginal support that friends' influence was stronger in young adolescents with higher moral disengagement. In early adolescence, bullying was also indirectly influenced through friends' moral disengagement, with different effects for boys and girls. With regard to defending, young adolescents maintained friendships with peers who were similar in defending, and became more similar to friends in terms of defending over time. These findings suggest important differences between late childhood and early adolescence in socialization processes and indicate that in early adolescence, friends' influence on the development of bullying is partially affected by moral disengagement.

Behavioral adjustment in prenatally cocaine-exposed adolescents

Behavioral adjustment in prenatally cocaine-exposed adolescents

Active vaccination inhibits the acquisition of methamphetamine self-administration in rats

Active vaccination inhibits the acquisition of methamphetamine self-administration in rats

Arsenic exposure in early pregnancy alters genome-wide DNA methylation in cord blood, particularly in boys.

Early-life inorganic arsenic exposure influences not only child health and development but also health in later life. The adverse effects of arsenic may be mediated by epigenetic mechanisms, as there are indications that arsenic causes altered DNA methylation of cancer-related genes. The objective was to assess effects of arsenic on genome-wide DNA methylation in newborns. We studied 127 mothers and cord blood of their infants. Arsenic exposure in early and late pregnancy was assessed by concentrations of arsenic metabolites in maternal urine, measured by high performance liquid chromatography-inductively coupled plasma mass spectrometry. Genome-wide 5-methylcytosine methylation in mononuclear cells from cord blood was analyzed by Infinium HumanMethylation450K BeadChip. Urinary arsenic in early gestation was associated with cord blood DNA methylation (Kolmogorov-Smirnov test, P-value<10-15), with more pronounced effects in boys than in girls. In boys, 372 (74%) of the 500 top CpG sites showed lower methylation with increasing arsenic exposure (r S -values>-0.62), but in girls only 207 (41%) showed inverse correlation (r S -values>-0.54). Three CpG sites in boys (cg15255455, cg13659051 and cg17646418), but none in girls, were significantly correlated with arsenic after adjustment for multiple comparisons. The associations between arsenic and DNA methylation were robust in multivariable-adjusted linear regression models. Much weaker associations were observed with arsenic exposure in late compared with early gestation. Pathway analysis showed overrepresentation of affected cancer-related genes in boys, but not in girls. In conclusion, early prenatal arsenic exposure appears to decrease DNA methylation in boys. Associations between early exposure and DNA methylation might reflect interference with de novo DNA methylation.