Early Adolescent Period Research Articles

Primary school students' opinions about the competences of physical education teachers: The role of gender, age and training

Previous studies of the competences of physical education teachers point to the problematic operationalization of the questionnaires designed to assess the competences of teachers based on students' assessment, as well as to the presence of gender and age differences, and the differences related to the fact whether the students practice some sport outside formal education. The aim of the present research was to determine the latent structure of the Questionnaire of the Opinions about the Physical Education Teachers Competences as well as to examine the gender and age differences on the questionnaire dimensions. Additionally, the study was aimed at providing the answer to the question whether the fact that a student actively practices some sport is a factor that influences the answers on the different measures of the questionnaire. The study involved 119 students (46% male) aged 11 to 14, from the territory of Vojvodina. In the total sample, 19% of students attended the fifth grade, 31% attended the sixth grade, 18% attended the seventh, and 32% of students attended the eighth grade of primary school. A total of 64% of students were practicing some sport. The Questionnaire of the Opinions about the Physical Education Teachers Competences was used, which is intended for assessing the competences of teachers by students. Factor analysis extracted two main components of the questionnaire: professional competences and socio-emotional competences of teachers. The results point to the conclusion that on both components of the questionnaire younger students had higher scores, while gender differences were not detected. The differences in relation to practicing sports are present only in the case of the socio-emotional competences of physical education teachers, meaning that those students who practice sports outside formal education scored higher on this dimension. It seems that the competences of physical education teachers are of great importance in the period of early and middle adolescence, and they need to be adapted to students, depending on their socio-demographic characteristics and affection for sports and sports practicing.

The Role of BDNF in the Development of Fear Learning.

Brain-derived neurotrophic factor (BDNF) is a growth factor that is dynamically expressed in the brain across postnatal development, regulating neuronal differentiation and synaptic plasticity. The neurotrophic hypothesis of psychiatric mood disorders postulates that in the adult brain, decreased BDNF levels leads to altered neural plasticity, contributing to disease. Although BDNF has been established as a key factor regulating the critical period plasticity in the developing visual system, it has recently been shown to also play a role in fear circuitry maturation, which has implications for the emergence of fear-related mood disorders. This review provides a detailed overview of developmental changes in expression of BDNF isoforms, as well as their receptors across postnatal life. In addition, recent developmental studies utilizing a genetic BDNF single nucleotide polymorphism (Val66Met) knock-in mouse highlight the impact of BDNF on fear learning during a sensitive period spanning the transition into adolescent time frame. We hypothesize that BDNF in the developing brain regulates fear circuit plasticity during a sensitive period in early adolescence, and alterations in BDNF expression (genetic or environmental) have a persistent impact on fear behavior and fear-related disorders.

Neuropeptide Y expression confers benzo[a]pyrene induced anxiolytic like behavioral response during early adolescence period of male Wistar rats

Environmental neurotoxicant like benzo[a]pyrene (B[a]P) is known to induce neurobehavioral changes. Our previous reports address the adverse effect of B[a]P on the neurobehavioral responses and neuromorphology of sensitive brain regions in adolescent rats. Present study was conducted on male Wistar rat neonates at postnatal day 5 (PND5) to ascertain B[a]P induced anxiolytic like behavioral response could be an outcome of neuropeptide Y (NPY) overexpression in brain. Single intracisternal administration of B[a]P was carried out at PND5 to elucidate the role of NPY on neurobehavioral responses at PND30. The behavioral studies showed anxiolytic like effect of B[a]P in both light and dark box and elevated plus maze tests. Antioxidant assay involving glutathione peroxidase activity was significantly decreased where as lipid peroxidation was significantly augmented in both hippocampus and hypothalamus of B[a]P treated group as compared to naive and control. The neurotransmitter estimation by HPLC-ECD showed significant increase in 5-HT level in both hippocampus and hypothalamus of B[a]P treated group. Significant elevation in NPY expression was observed in both hippocampus and hypothalamus of B[a]P group. Intracellular Ca2+ estimation using Fura-2AM by fluorometry showed that B[a]P induced increase in Ca2+ influx was associated with augmented NPY expression in brain. As NPY has orexigenic effect, our result revealed that there was a significant increase in body weight at PND30 following B[a]P administration to rat neonates at PND5. These findings suggested that NPY overexpression in brain regions might be associated with anxiolytic like behavioral response and orexigenic effect in rats following single intracisternal B[a]P administration. Future research directing towards understanding the signaling cascades of B[a]P induced biochemical and neuromorphological alteration might address the independent pathway which induce neurodegeneration despite NPY overexpression in brain regions of adolescent rats.

Neonatal Benzo[a]pyrene Exposure Induces Oxidative Stress and DNA Damage Causing Neurobehavioural Changes during the Early Adolescence Period in Rats

Humans are exposed to polycyclic aromatic hydrocarbons (PAHs) by ingestion of contaminated food and water. Prenatal exposure to benzo[a]pyrene (B[a]P) like PAHs through the placental barrier and neonatal exposure by breast milk and the environment may affect early brain development. In the present study, single intracisternal administration of B[a]P (0.2 and 2.0 µg/kg body weight) to male Wistar rat pups at postnatal day 5 (PND5) was carried out to study its specific effect on neonatal brain development and its consequences at PND30. B[a]P administration showed a significant increase in exploratory and anxiolytic-like behaviour with elevated hippocampal lipid peroxidation and protein oxidation at PND30. Further, DNA damage was estimated in vitro (Neuro2a and C6 cell lines) by the comet assay, and oxidative DNA damage of hippocampal sections was measured in vivo following exposure to B[a]P. DNA strand breaks (single and double) significantly increased due to B[a]P at PND30 in hippocampal neurons and increased the nuclear tail moment in Neuro2a cells. Hippocampal 8-oxo-2′-deoxyguanosine production was significantly elevated showing expression of more TUNEL-positive cells in both doses of B[a]P. Histological studies also revealed a significant reduction in mean area and perimeter of hippocampal neurons in rats treated with B[a]P 2.0 μg/kg, when compared to naïve and control rats. B[a]P significantly increased anxiolytic-like behaviour and oxidative DNA damage in the hippocampus causing apoptosis that may lead to neurodegeneration in adolescence. The findings of the present study address the potential role of B[a]P in inducing oxidative stress-mediated neurodegeneration in the hippocampus through oxidative DNA damage in the early adolescence period of rats.

Age-related changes in the relationship between alcohol use and violence from early adolescence to young adulthood

BackgroundDespite the accumulation of studies examining the link between alcohol use and violence, no studies to our knowledge have systematically set out to detect age-related differences in these relationships. This limitation inhibits important insights into the stability of the relationship between alcohol use and violence among youth across varying ages. MethodStudy findings are based on repeated, cross-sectional data collected annually as part of the National Survey on Drug Use and Health between 2002 and 2013. We combined a series of nationally representative cross-sections to provide a multi-year string of data that, in effect, reflects a nationally representative non-traditional cohort. We conducted logistic regression analyses to examine the cross-sectional association between non-binge and binge drinking and violent attacks among youth between ages 12 (2002) and 24/25 (2013). ResultsWith respect to the association between non-binge alcohol use and violence, the only significant relationship identified—while controlling for sociodemographic and drug use factors—was for youth at age 13 (2003; OR=1.97, 95% CI=1.04–3.72). For binge drinking, we identified a distinct pattern of results. Controlling for sociodemographic, drug use factors, and school enrollment, binge drinking was significantly associated with violence between ages 13 (2003) and 20 (2010) with the largest odds ratios observed during the early adolescent period. ConclusionsNon-binge drinking is associated with violent behavior at age 13. Binge drinking was found to be associated with violence among youth through age 20; however, the relationship dissipates when youth arrive at the legal drinking age of 21.

Neonatal exposure to benzo[a]pyrene induces oxidative stress causing altered hippocampal cytomorphometry and behavior during early adolescence period of male Wistar rats

Environmental neurotoxicants like benzo[a]pyrene (B[a]P) have been well documented regarding their potential to induce oxidative stress. However, neonatal exposure to B[a]P and its subsequent effect on anti-oxidant defence system and hippocampal cytomorphometry leading to behavioral changes have not been fully elucidated. We investigated the effect of acute exposure of B[a]P on five days old male Wistar pups administered with single dose of B[a]P (0.2μg/kg BW) through intracisternal mode. Control group was administered with vehicle i.e., DMSO and a separate group of rats without any treatment was taken as naive group. Behavioral analysis showed anxiolytic-like behavior with significant increase in time spent in open arm in elevated plus maze. Further, significant reduction in fall off time during rotarod test showing B[a]P induced locomotor hyperactivity and impaired motor co-ordination in adolescent rats. B[a]P induced behavioral changes were further associated with altered anti-oxidant defence system involving significant reduction in the total ATPase, Na+ K+ ATPase, Mg2+ ATPase, GR and GPx activity with a significant elevation in the activity of catalase and GST as compared to naive and control groups. Cytomorphometry of hippocampus showed that the number of neurons and glia in B[a]P treated group were significantly reduced as compared to naive and control. Subsequent observation showed that the area and perimeter of hippocampus, hippocampal neurons and neuronal nucleus were significantly reduced in B[a]P treated group as compared to naive and control. The findings of the present study suggest that the alteration in hippocampal cytomorphometry and neuronal population associated with impaired antioxidant signaling and mood in B[a]P treated group could be an outcome of neuromorphological alteration leading to pyknotic cell death or impaired differential migration of neurons during early postnatal brain development.

Health-Related Behaviour of Czech Adolescents

This study presents partial results of an extensive research project called Health-Enhancing and Health-Threatening Behaviour: Determinants, Models, and Consequences (GA13-19808S) and explores selected factors of health-promoting behaviour of Czech adolescents. The study discussed the interconnections found between components of health-related behaviour of adolescents during a key stage of their development. In addition, we also aimed to study possible developmental trend of the above-mentioned correlates during adolescence. The subjects participating in the above-described broad research project were administered an extensive battery of tests, and as a part of the presented study, the descriptive data concerning the subjects’ age and sex, the Health-Related Behaviour Scale (Dosedlová et al., 2013), the Subjective Health Problems Inventory (modified version of the inventory by Osecká et al., 1998), Mental Health Continuum, MHC-SF (Keyes, 2005) and the Big Five Inventory (O.P. Donahue, R.I. Kentle, 1991) were all used. The research sample consisted of 735 adolescents (47.4% women and 52.6% men) aged 12-19 years (35.3% in the period of early and middle adolescence and 64.7% in the period of late adolescence). In cluster analysis, six different life styles were defined using five health-related factors. Analyses of variance were conducted to examine whether adolescents with different life-styles differ in chosen personal characteristics.

Neurotoxic Effect of Benzo[a]pyrene and Its Possible Association with 6-Hydroxydopamine Induced Neurobehavioral Changes during Early Adolescence Period in Rats.

Exposure to persistent genotoxicants like benzo[a]pyrene (B[a]P) during postnatal days causes neurobehavioral changes in animal models. However, neurotoxic potential of B[a]P and its association with 6-hydroxydopamine (6-OHDA) induced neurobehavioral changes are yet to be explored. The growth of rat brain peaks at the first week of birth and continues up to one month with the attainment of adolescence. Hence, the present study was conducted on male Wistar rats at postnatal day 5 (PND 5) following single intracisternal administration of B[a]P to compare with neurobehavioral and neurotransmitter changes induced by 6-OHDA at PND 30. Spontaneous motor activity was significantly increased by 6-OHDA showing similar trend following B[a]P administration. Total distance travelled in novel open field arena and elevated plus maze was significantly increased following B[a]P and 6-OHDA administration. Neurotransmitter estimation showed significant alleviation of dopamine in striatum following B[a]P and 6-OHDA administration. Histopathological studies of striatum by hematoxylin and eosin (H&E) staining revealed the neurodegenerative potential of B[a]P and 6-OHDA. Our results indicate that B[a]P-induced spontaneous motor hyperactivity in rats showed symptomatic similarities with 6-OHDA. In conclusion, early postnatal exposure to B[a]P in rats causing neurobehavioral changes may lead to serious neurodegenerative consequences during adolescence.

Social Self-Regulation in the Context of Applied Parental Styles and Preferred Styles of Coping in Early and Middle Adolescence – Pilot Study

The study was realised as a part of an extensive research plan, which aims at tracing a developmental trend in the development of self-regulation of an individual in the context of coping, self-efficacy and self-esteem, by monitoring selected connections between social self-regulation, applied parental educational styles and preferred strategies of coping in the period of early and middle adolescence. Since this is already a widely held belief this study may be considered unnecessary unless the writers say that this study hopes to provide further empirical evidence to support this belief. In order to execute the above mentioned research plan, we have chosen a quantitative research design realised through a one-time interview survey by using a combination of questionnaire methods: Social selection, optimisation and compensation questionnaire (Social SOC; Geldholf, Little, Hawley, 2012), Parents Perception Scale (Niemiec, Ryan & Deci 1991; adapted Robbins 1994) and Children´s Coping Strategies Checklist (Ayers et al., 1996). This study included 229 respondents aged 13 to 15 (M=14,7; sd=0,712), from which 53.3% were girls (N=122) and 46.7% were boys (N=107). The results of the study generated many findings related to self-regulation and coping strategies with a focus on significant gender differences in social self-regulation and also differences in preferred coping strategies (r=44,21,sd=7,896). From a practical point of view, the study generated valuable conclusions about differences in preferred styles of coping in relation to applied parental educational styles – e.g. the group of respondents with low average scores in Parents Perception Scale had statistically considerably lower score in several fundamental coping strategies (COP_ACT (p<0,001) and COP_SUP (p<0,001)).

Change and predictors of change in parental self-efficacy from early to middle adolescence.

Parental self-efficacy (PSE) describes parents' beliefs about being able to handle developmentally specific issues and being able to influence their child in a way that fosters the child's positive development and adjustment (Bandura, 1997). Parents of adolescents have been shown to feel less efficacious than parents of preadolescent children (Ballenski & Cook, 1982), but little is known about the factors behind low levels of PSE among parents of adolescents. This study examined mean-level changes in PSE and predictors of change among parents of adolescents. The sample was derived from a 3-wave longitudinal data set of 398 parents of children starting spanning early (11 or 12 years) to middle (14 or 15 years) adolescence (47% boys). Latent growth curve analysis was performed, and it was hypothesized that theoretically driven predictors reflecting the developing child, as well as the ecological context, would predict the level of PSE. Despite generally high levels of PSE across all time points, parents decreased in PSE during the developmental period. Some predictors were of particular importance for the level and amount of change in PSE, such as physical changes in the child, parents' target-based expectations for risk taking during adolescence, the quality of parent-adolescent communication, and ethnicity. This study adds insight into the development of PSE during the critical transitional period of early and middle adolescence. The findings advance theory of PSE, as it illuminates why some parents' decrease in PSE more than do other parents.

Central nervous system manifestations of Mycoplasma pneumoniae: Report of two children

Mycoplasma pneumoniae is a common infection in the early adolescent period, presenting most commonly as an upper respiratory tract infection with variable severity. Extrapulmonary manifestations include neurologic, hematologic, hepatic, and cardiac involvement. Hemiparesis and dysarthria are frequently encountered in the setting of cerebrovascular accidents. We present two patients who had neurological complications secondary to Mycoplasma pneumoniae infection. The first patient was a 12-year-old boy who presented with recurrent episodes of transient hemiparesis and dysarthria. The second patient was a 3-year-old girl who presented with seizures and aphasia. Both patients had pneumonia and positive serum immunoglobulin M against Mycoplasma pneumoniae. Follow up revealed a full recovery in the first case and moderate articulation disorder in the second patient.

The influence of sport club participation on physical activity, fitness and body fat during childhood and adolescence: The LOOK Longitudinal Study.

To investigate the longitudinal effect of sport participation in physical activity, fitness and body fat changes during childhood and adolescence. Longitudinal study (134 boys, 155 girls) of Australian youth aged 8-16 years. Physical activity was assessed by pedometers and accelerometers, fitness by the 20m shuttle-run, body fat by DEXA and club sport participation by questionnaire. Linear mixed models were used to determine the effects of sport participation and gender differences. Sports club participants were more physically active at all age groups than non-participants; boys took an extra 1800 steps (p<0.001) and girls 590 steps per day (p<0.01) and boys engaged in an extra 9min and girls 6min more moderate to vigorous PA per day (both p<0.05). Fitness was higher among sports participants (boys 27% and girls 20% higher, both p<0.001) and sport participant girls had 2.9% less body fat (p<0.05). Higher fitness scores were maintained over time by sports participants but their greater PA diminished during adolescence, this being more evident among girls. Only 20% of sports club participants met the recommended daily average of 60min MVPA. Sport participants were more active, fitter and had less body fat (girls only) than non-sports participants. However, the associated benefits of sport with PA diminished during adolescence and the majority of sports participants did not meet recommended levels of PA. Strategies aiming to maximise the benefits of sports participation may be enhanced by providing special attention to the early adolescent period particularly among girls.

The relationship between internalising symptom development and academic attainment in early adolescence.

Evidence for the longitudinal associations between internalising symptom development and academic attainment is sparse and results from existing studies are largely inconclusive. The approaches that have been used in existing studies examining this relationship have in common the limitation of grouping together all individuals in the sample which makes the assumption that the relationship between time, symptoms and attainment across all individuals is the same. The current study aimed to use heterogeneous trajectories of symptom development to examine the longitudinal associations between internalising symptom development and change in academic attainment over a three years period in early adolescence, a key period for internalising symptom development. Internalising symptoms were assessed for 3 consecutive years in a cohort from age 11–14 years (n = 2647, mean age at T1 = 11.7 years). National standardised test scores prior to the first wave and subsequent to the last wave were used as measures of academic attainment. Heterogeneous symptom development trajectories were identified using latent class growth analysis and socio-demographic correlates, such as gender, SES and ethnicity, of the different trajectory groupings were investigated. Derived trajectory groupings were examined as predictors of subsequent academic attainment, controlling for prior attainment. Results demonstrate that symptom trajectories differentially predicted change in academic attainment with increasing trajectories associated with significantly worse academic outcomes when compared to pupils with low levels of symptoms in all waves. Hence, a trajectory based approach provides a more nuanced breakdown of complexities in symptom development and their differential relationships with academic outcomes and in doing so helps clarify the longitudinal relationship between these two key domains of functioning in early adolescence.

Neonatal Isolation Stress Inhibits Pre-Weaning Weight Gain and Mild-Stressor Induced Locomotor Activity in Early Adolescent Male and Female Rats

The present study looked at the effects of neonatal isolation, an early life stress experience, in male and female early adolescent rats, an age which is underrepresented in the early stress literature. Four stress-sensitive indices were assessed: weight gain during the pre-weaning period, open field activity, and locomotor activity in response to two mild stressors: exposure to a novel environment, and a single IP saline injection. Rats in the neonatal isolation condition were removed from dam and littermates on postnatal days 2-9 in accord with the procedure used by Kehoe et al. (1995); behavioral testing occurred on PN25-PN30 during the early adolescent period. It was found that neonatally isolated pups weighed less than non-isolate controls on each of three measurement days (PN7, PN14, PN21) throughout the pre-weaning period. Further, neonatal isolation experience consistently reduced horizontal locomotor activity measured in the open field, in a novel environment, and following a single mild acute stressor. On some measures, behavior reflected greater impact of NI in males compared with NI females, suggesting that the effects of NI in early adolescent rats may be sexually dimorphic.

Twenty Years After International Conference on Population and Development: Where Are We With Adolescent Sexual and Reproductive Health and Rights?

The International Conference on Population and Development in Cairo in 1994 laid out a bold, clear, and comprehensive definition of reproductive health and called for nations to meet the educational and service needs of adolescents to enable them to deal in a positive and responsible way with their sexuality. In the context of the ongoing review of the International Conference on Population and Development Programme of Action and the considerations for a post-2015 development agenda, this article summarizes the findings of the articles presented in this volume and identifies key challenges and critical answers that need to be tackled in addressing adolescent sexual and reproductive health and rights. The key recommendations are to link the provision of sexuality education and sexual and reproductive health (SRH) services; build awareness, acceptance, and support for youth-friendly SRH education and services; address gender inequality in terms of beliefs, attitudes, and norms; and target the early adolescent period (10–14 years). The many knowledge gaps, however, point to the pressing need for further research on how to best design effective adolescent SRH intervention packages and how best to deliver them.

Adolescent exposure to cocaine, amphetamine, and methylphenidate cross-sensitizes adults to methamphetamine with drug- and sex-specific effects

The increasing availability, over-prescription, and misuse and abuse of ADHD psychostimulant medications in adolescent populations necessitates studies investigating the long-term effects of these drugs persisting into adulthood. Male and female C57Bl/6J mice were exposed to amphetamine (AMPH) (1.0 and 10mg/kg), methylphenidate (MPD) (1.0 and 10mg/kg), or cocaine (COC) (5.0mg/kg) from postnatal day 22 to 31, which represents an early adolescent period. After an extended period of drug abstinence, adult mice were challenged with a subacute methamphetamine (METH) dose (0.5mg/kg), to test the long-term effects of adolescent drug exposures on behavioral cross-sensitization using an open field chamber. There were no sex- or dose-specific effects on motor activity in adolescent, saline-treated controls. However, AMPH, MPD, and COC adolescent exposures induced cross-sensitization to a subacute METH dose in adulthood, which is a hallmark of addiction and a marker of long-lasting plastic changes in the brain. Of additional clinical importance, AMPH-exposed male mice demonstrated increased cross-sensitization to METH in contrast to the female-specific response observed in MPD-treated animals. There were no sex-specific effects after adolescent COC exposures. This study demonstrates differential drug, dose, and sex-specific alterations induced by early adolescent psychostimulant exposure, which leads to behavioral alterations that persist into adulthood.

Physiological reactivity moderates the association between parental directing and young adolescent friendship adjustment.

This study examined whether the longitudinal association between parental directing of friendships (i.e., encouraging or discouraging certain friendships) and young adolescents' friendship adjustment (i.e., friendship quality and friends' positive characteristics) was moderated by skin conductance level reactivity (SCLR) to peer stress. Participants included 123 young adolescents (M age = 12.03 years at Time [T]1; 50% boys; 58.5% European Americans). At T1 (summer before the transition to middle school), parents reported on the extent to which they directed adolescents toward or away from certain peers, and adolescents' SCLR was assessed during a lab-based peer evaluation task. At T1 and T2 (spring of the first year of middle school), adolescents reported on the quality of their friendships and positive peer affiliations. Controlling for T1 friendship adjustment, parental directing predicted higher friendship quality and more positive peer affiliations, but only among young adolescents with lower SCLR, which was conceptualized as a marker of underarousal and insensitivity to stress. Results are discussed with reference to the developmental period of early adolescence and related research on interactions between parental control and child characteristics as predictors of adolescent adjustment.

Physical activity levels and energy expenditure in urban Serbian adolescents--a preliminary study.

The aim of this study was to evaluate the level of PA and EE in Serbian urban adolescents, using an objective measure. In particular, we explored gender and weight status related differences in PA level and EE among Serbian adolescents. In addition, their PA and EE obtained during schooldays and weekends were compared. From the representative sample of elementary schools in Belgrade, one school was selected by random sampling for the purpose of the objective PA assessment. The sample included 115 students (53 boys and 62 girls) of the average age 14.0 (0.6) years. EE and the duration of PA levels were assessed by the Sense Wear PRO3 Armband device (Body Media Inc., Pittsburgh, PA, USA). IOTF cut-off points were used to define subjects as non-overweight, overweight or obese. Analysis of variance was applied to examine the impacts of gender and weight status on EE and PA duration. Adolescents spent most of the time in sedentary regime 241.7 ± 62.8 min/day, on average and they were totally physically active for 196.0 ± 73.5 min/day. Boys accumulated more PA than girls and during schooldays, the PA of all adolescents was higher than during weekend days. OW girls spent less time in total PA, MPA, and VVPA. On the other hand, NW and OW boys differed only in VVPA. Consequently, OW girls had lower energy expenditure compared with their NW peers, but no such differences in boys were found. The results of this study indicate that low PA activity might be a more important factor in propagation of overweight in girls than boys, at least in early adolescent period. PA in girls should be strongly encouraged, with a special focus on vigorous PA during weekends.

Childhood growth, schooling, and cognitive development: further evidence from the Young Lives study

A growing literature has linked early childhood growth to later-life cognition and schooling outcomes in developing countries. Although existing evidence suggests that children's ability to recover from early growth delays in later childhood is limited, longitudinal studies on the persistence and risk of growth faltering beyond age 5 y remain scarce. Using longitudinal data recently collected from 4 developing countries as part of the Young Lives study, we investigated catch-up growth in children between the ages of 8 and 15 y and the effects of growth during this late-childhood and early-adolescence period on schooling and developmental outcomes. We analyzed the associations between children's physical growth and development by using longitudinal data from 3327 children aged 8-15 y collected in Ethiopia, India, Peru, and Vietnam as part of the Young Lives project. The study yielded 2 main results. First, 36% of children stunted at age 8 y managed to catch up with their peers by age 15 y, and those who caught up had smaller deficits in cognitive scores than did children who remained stunted. Second, physical growth faltering was not restricted to early childhood but rather affected a substantial share of children in the 8-15-y age range, with large negative consequences for cognition and schooling outcomes. The results from this study suggest that child development in developing countries is a dynamic process offering continued opportunities for children to catch up during adolescence and sustained risks for children to fall behind in their developmental trajectories.

Which emotional regulatory strategy makes Chinese adolescents happier? A longitudinal study.

Growing interest in emotion regulation is reflected in the studies of cognitive and social development. However, the extant studies mainly highlight how emotion regulation develops based on a western value system. This study utilised a longitudinal design to examine the development of emotion regulation and explored the contributions of different regulatory strategies to emotion experience regarding the early adolescent development period in a Chinese population. A total of 303 Chinese adolescents (age range = 10-14 years) were followed up in a three-phase longitudinal study for 3 years. In each phase of the study, participants completed Adolescents Emotion Regulation Questionnaire and Daily Emotion Scale. Results of hierarchical linear regressions revealed that Chinese adolescents reported more down-regulation. Down-regulation is more effective than up-regulation in enhancing desirable emotion experience and reducing undesirable emotion experience during adolescents' development. Also, the adaptive functions of emotional regulatory strategies in Chinese background were discussed.