Changes In Boys Research Articles

Initial Outcomes of a Participatory-Based, Competency-Building Approach to Increasing Physical Education Teachers' Physical Activity Promotion and Students' Physical Activity: A Pilot Study.

This study examined the initial effects of a participatory-based, competency-/skill-building professional development workshop for physical education (PE) teachers on the use of physical activity (PA) promotion practices (e.g., eliminating lines, small-sided games) and students' moderate-to-vigorous physical activity (MVPA). A total of 823 students (52.8% boys) wore accelerometers at baseline (fall 2015) and outcome (spring 2016) on PE and non-PE days. The System for Observing Fitness Instruction Time+ measured changes in PA promotion practices. Teachers ( n = 9) attended a 90-minute workshop prior to outcome data collection. Mixed-model linear regressions estimated changes in teacher practices and students' MVPA. Three of the nine targeted PA promotion practices changed in the desired direction (i.e., p < .05; increased motor content and lessons taught outdoors, reduced activities with lines), with three more teacher practices trending in the desired direction (i.e., reduced management time and activities with elimination, increased small-sided games). During PE, boys and girls increased MVPA by 2.0 (95% confidence interval [1.1, 3.0]), and 1.3 (95% confidence interval [0.5-2.0]) minutes, respectively. However, there were no statistically significant changes in boys' or girls' MVPA during the school day. Greater implementation of promotion practices by the PE teachers was associated with boys', but not girls', MVPA during PE. Girls in high- and low-implementing teachers' lessons experienced increases in MVPA, suggesting that even small changes in PA promotion practices can increase girls' MVPA during PE. Overall, the workshops were effective at increasing teachers' PA promotion and students' MVPA in PE. Other school-based strategies that complement and extend efforts targeting PE are recommended to increase children's total daily PA.

Toward a pedagogy informed by research about the boy's changing voice

Toward a pedagogy informed by research about the boy's changing voice

Within-person changes in salivary testosterone and physical characteristics of puberty predict boys' daily affect

Recent investigations highlighted the role of within-person pubertal changes for adolescents' behavior. Yet, little is known about effects on adolescents' daily affect, particularly regarding the hormonal changes underlying physical changes during puberty. In a study with 148 boys aged 10 to 20years, we tested whether within-person physical and hormonal changes over eight months predicted everyday affect fluctuations, measured with experience sampling. As expected, greater within-person changes in testosterone (but not in dehydroepiandrosterone) were associated with higher affect fluctuations in daily life. Additionally, greater physical changes predicted higher affect fluctuations for individuals in the beginning of puberty. The findings demonstrate the relevance of physical and hormonal changes in boys' affective (in)stability.

Longitudinal changes in pubertal maturation and white matter microstructure

Emerging evidence in the field of adolescent neurodevelopment suggests that pubertal processes may contribute to known trajectories of brain maturation, and may contribute, in part, to sex differences in related cognitive, behavioral and mental health outcomes. The current longitudinal study examined how changes in physical pubertal maturation (measured by the Peterson Developmental Scale) predict changes in white matter microstructure in 18 boys and 15 girls over an approximate 2-year follow-up period, while accounting for age. Using Tract-Based Spatial Statistics and multi-level modeling, the results showed that physical pubertal changes predict patterns of changes in fractional anisotropy (FA) in white matter regions in the thalamus, precentral gyrus, superior corona radiata, corpus callosum (genu), superior corona radiata, and superior frontal gyrus. Sex specific changes were also seen, as changes in gonadal and adrenal development related to increases in FA in the superior frontal gyrus and precentral gyrus in boys, but gonadal development related to decreases in FA in the anterior corona radiata in girls. These findings are the first to show how changes over time in pubertal development influence white matter development. In addition, they support a larger body of emerging research suggesting that pubertal processes contribute to distinct changes in boys and girls across brain development.

Collaborative cognitive-activation strategies as an emancipatory force in promoting girls’ interest in and enjoyment of mathematics: A cross-national case study

The results of international large-scale assessments have revealed the emergence of gender disparities in attitudes to mathematics, with girls generally demonstrating lower levels of interest in and enjoyment of mathematics than boys. Given that attitudes to mathematics are key determinants of future STEM participation, collaborative cognitive-activation teaching strategies, which harmonise with the core tenets of feminist mathematical pedagogy, are proposed as a possible approach to improving girls’ relationships with mathematics. The results of a small-scale cross-national case study that incorporated this approach through a six week intervention are reported. The findings show a significant increase in girls’ enjoyment of mathematics but there was no significant change in boys’ attitudes. Potential implications for mathematics education policy and practice are elucidated.

The relationship between facial morphology, body measurements and socio-economic factors

Background and aim: The effect of socio-economic factors (living conditions) and parental smoking habits on development of facial morphology and body measurements was studied on a longitudinal Czech sample of 25 girls and 25 boys.&#x0D; Subjects and methods: A set of studied digitalized photographs taken from 0.5 to 18 years in intervals of 6 months originated in the Brno Longitudinal Study. Facial shape changes of sub-adult participants were described using a configuration of 27 landmarks and further studied by using methods of geometric morphometric and multivariate statistics. In order to localize growth-related shape changes within the face, the studied region was divided into upper, middle and lower facial units and analyzed separately.&#x0D; Results and conclusion: The results show that in the course of ontogenesis there is a strong correlation between facial shape change and body measurements, height included (r=0.10 and r=0.24 in boys and in girls, respectively). The pubertal spurt of the facial shape change rate was revealed at 10.5 years in girls and at 11.5 years in boys. The earlier onset of the pubertal rate increase in facial shape changes in boys was associated with records of poor living conditions. In addition, the mother’s smoking habits were linked to a noticeable facial shape change.

Re. “Prospective study of histological and endocrine parameters of gonadal function in boys with cryptorchidism”

Verkauskasa et al. are to be commended on the depth of their investigation on hormonal parameters and histological changes in boys with cryptorchidism [1]. The overall finding of the study, which is that Ad spermatogonia counts decrease with age of cryptorchid testis biopsy, is consistent with other studies and highlights the need for prompt treatment of cryptorchid patients after 6 months of age [2]. In the subgroup that had a high risk of infertility because of absence of Ad spermatogonia stem cells, the LH levels were lower than expected, consistent with this subgroup having a hypogonadotropic hypogonadism. However, this group is small, less than 20% of the total sample. While the Ad numbers were low in the patients studied, it appears that the count was zero in only 21/51 pts (i.e. the majority of testes showed some germ cell maturation). The authors claim that transformation of gonocytes into Ad spermatogonia is testosterone dependent; however, there are also contrary animal and human studies which show that, even in complete androgen insensitivity, Ad spermatogonia appear normal initially. This would suggest that gonocyte transformation into Ad spermatogonia may be androgen-independent. Furthermore, several recent studies in animals and humans show that the pathogenesis and etiology of isolated cryptorchidism is likely multifactorial and in most cases unknown [3]. The bottom line is this: while men with a history of unilateral cryptorchidism tend to have lower sperm counts than the normal

Symbolic dynamics of heart rate variability - a promising tool to investigate cardiac sympathovagal control in attention deficit/hyperactivity disorder (ADHD)?

We aimed to evaluate complex cardiac sympathovagal control in attention deficit/hyperactivity disorder (ADHD) by using heart rate variability (HRV) nonlinear analysis - symbolic dynamics. We examined 29 boys with untreated ADHD and 25 healthy boys (age 8-13 years). ADHD symptoms were evaluated by ADHD-RS-IV scale. ECG was recorded in 3 positions: baseline supine position, orthostasis, and clinostasis. Symbolic dynamics indices were used for the assessment of complex cardiac sympathovagal regulation: normalised complexity index (NCI), normalised unpredictability index (NUPI), and pattern classification measures (0V%, 1V%, 2LV%, 2UV%). The results showed that HRV complexity was significantly reduced at rest (NUPI) and during standing position (NCI, NUPI) in ADHD group compared to controls. Cardiac-linked sympathetic index 0V% was significantly higher during all posture positions and cardiovagal index 2LV% was significantly lower to standing in boys suffering from ADHD. Importantly, ADHD symptom inattention positively correlated with 0V%, and negatively correlated with NCI, NUPI. Concluding, symbolic dynamics revealed impaired complex neurocardiac control characterised by potential cardiac beta-adrenergic overactivity and vagal deficiency at rest and to posture changes in boys suffering from ADHD that is correlated with inattention. We suggest that symbolic dynamics indices could represent promising cardiac biomarkers in ADHD.

Is there a link between per capita alcohol consumption and youth drinking? A time-series analysis for Sweden in 1972-2012.

AimsTo estimate the relationship between per capita alcohol consumption and youth drinking in Sweden during the last 40 years and to estimate the relationship between female and male youth drinking during the 40‐year study period.Design, setting, participants and measurementsPer capita alcohol consumption was proxied by official sales data, supplemented by data on unrecorded consumption. Youth consumption was measured by a question on heavy episodic drinking (HED) included in an annual school survey of alcohol and drug habits among Swedish 9th ‐grade students (15–16 years of age). The annual samples comprise approximately 5000 individuals (with roughly equal numbers of boys and girls) with response rates in the range 80–93%. The study spans the period 1972–2012. Autoregressive integrated moving average (ARIMA) time–series analysis was used to estimate the relation between per‐capita alcohol consumption and youth drinking. Ocular inspection of the time–series data suggested a stronger synchronization between the two series in the early period, before the mid‐1990s, than in the later period, indicating a structural shift in the relation at issue. We therefore conducted period specific time–series analyses with 1995 as the year of division.ResultsThere was a statistically significant relation between per capita alcohol consumption and HED among youth for 1972–94. A 1% increase in per capita alcohol consumption was associated with an increase in HED of 1.52% (P = 0.008). The estimate for 1995–2012 (0.12) was well below statistical significance (P = 0.580). The estimated elasticity of the association between boys’ and girls’ HED during 1972–94 was close to unity (0.98, P < 0.001), suggesting proportional changes in boys’ and girls’ drinking. When controlling for per capita consumption, the association was halved (to 0.55) but still significant in table 3 (P = 0.045).ConclusionsAdult and youth drinking in Sweden were synchronized closely during the two last decades of the 20th century, but youth drinking developed an independent trajectory shortly before 2000.

Análisis de los efectos físicos de las concentraciones deportivas en judokas en edades escolares (Physical effects of the sports concentrations in judokas in school ages)

Los objetivos de este estudio han sido analizar la carga de entrenamiento y competición desarrollada en una concentración del equipo nacional, describir los efectos físicos que conlleva en los judokas y determinar si aparecen diferencias entre sexos. La muestra estaba formada por 29 judokas adolescentes (15 chicas y 14 chicos) de 15.2 ± 0.9 años de media. Se realizaron dos valoraciones, antes y después de la concentración, las cuales siguieron el mismo protocolo de pruebas: peso, talla, flexibilidad «sit and reach» y «dedos-suelo», CMJ y la fuerza isométrica manual. Los resultados muestran que el tiempo total de entrenamiento en tatami fue de 50700 seg (aproximadamente 14 horas) divididos en 6 sesiones. Las variables físicas afectadas por la carga de entrenamiento desarrollada fueron el peso corporal y la flexibilidad isquiosural, las cuales incrementaron significativamente sólo en las chicas al finalizar la concentración (p&lt;0.05), sin mostrar cambios físicos en los chicos. Por lo tanto, se manifiesta una buena orientación del trabajo en la concentración, no existiendo un volumen de entrenamiento que conlleve una sobrecarga en los judokas adolescentes.Palabra clave: judo, entrenamiento, adolescentes, escolares.Abstract: The objectives of this study were to analyze the burden of training and competition developed in a concentration of the national team, describe the physical effects involved in judokas and whether differences between sexes. The sample included 29 judokas adolescents (15 girls and 14 boys) of 15.2 ± 0.9 years on average. Two tests were performed before and after the merger, which followed the same testing protocol: weight, height, flexibility «sit and reach» and «finger-floor», CMJ and isometric force manual. The results show that the total training time was 50700 sec mat (approx. 14 hours) dividid into 6 sessions. The variables affected by the physical training load were developed body weight and flexibility isquiosural, which increased significantly only in girls when the concentration (p &lt;0.05), without showing physical changes in boys. Therefore, there is a good guide to the concentration of work, no amount of training that involves an in overcharging judokas adolescents.Key words: judo, training, young, school ages.

Marital problems, maternal gatekeeping attitudes, and father–child relationships in adolescence.

We evaluated maternal gatekeeping attitudes as a mediator of the relation between marital problems and father-child relationships in 3 waves when children were in Grades 7-10. We assessed each parent's contribution to the marital problems experienced by the couple. Findings from mediational and cross-lagged structural equation models revealed that increased marital problem behaviors on the part of mothers at Wave 1 predicted increased maternal gatekeeping attitudes at Wave 2, which in turn predicted decreased amounts of father-adolescent interaction at Wave 3. Decreased amounts of interaction with either parent were associated within each wave with adolescents' perceptions that they mattered less to that parent. Amount of interaction with fathers at Wave 2 positively predicted changes in boys' perceptions of how much they mattered to their fathers at Wave 3, and amount of interaction with mothers at Wave 2 positively predicted changes in girls' perceptions of how much they mattered to their mothers at Wave 3. The findings did not differ for European American versus Mexican American families or for biological fathers versus step-fathers.

La muda de la voz en los varones adolescentes: Implicaciones y consecuencias para el canto y la música coral escolar

The aim of this paper is twofold. On the one hand, it aims to present an overview about the research, theory and philosophy in relation to the boy's changing voice, with focus on physiological, psy...

Sex-specific effects of early life cadmium exposure on DNA methylation and implications for birth weight

Dietary cadmium exposure was recently found to alter DNA methylation in adults, but data on effects early in life are lacking. Our objective was to evaluate associations between prenatal cadmium exposure, DNA methylation and birth weight. In total 127 mother-child pairs from rural Bangladesh were studied. For comparison, we included 56 children at 4.5 y. Cadmium concentrations in mothers’ blood (gestational week 14) and children’s urine were measured by ICPMS. Global DNA methylation was analyzed by Infinium HumanMethylation450K BeadChip in cord blood and children’s blood. Maternal cadmium exposure was associated with cord blood DNA methylation (p-value < 10–16). The association was markedly sex-specific. In boys, 96% of the top 500 CpG sites showed positive correlations (rS-values > 0.50), whereas most associations in girls were inverse; only 29% were positive (rS > 0.45). In girls we found overrepresentation of methylation changes in genes associated with organ development, morphology and mineralization of bone, whereas changes in boys were found in cell death-related genes. Several individual CpG sites that were positively associated with cadmium were inversely correlated with birth weight, although none statistically significant after correction for multiple comparisons. The associations were, however, fairly robust in multivariable-adjusted linear regression models. We identified CpG sites that were significantly associated with cadmium exposure in both newborns and 4.5-y-old children. In conclusion, cadmium exposure in early life appears to alter DNA methylation differently in girls and boys. This is consistent with previous findings of sex-specific cadmium toxicity. Cadmium-related changes in methylation were also related to lower birth weight.

A prospective study of global DNA methylation and development of adiposity in Colombian schoolchildren

ObjectiveTo examine associations of global DNA methylation with changes in adiposity in a longitudinal study of school‐age children from Bogotá, Colombia.MethodsWe quantified methylation of LINE‐1 elements from peripheral leukocytes of 553 children aged 5–12 y at baseline using pyrosequencing technology (Qiagen). Anthropometric characteristics were measured periodically for a median of 30 months. We estimated mean change in 3 age‐standardized indicators of adiposity: body mass index (BMI) Z score (BMIZ), waist circumference Z score (WCZ), and triceps‐to‐subscapular skinfold thickness ratio Z score (SKFZ) according to quartiles of LINE‐1 methylation using multivariable mixed effects linear regression.ResultsThere were inverse, non‐linear relations of DNA methylation with BMIZ and SKFZ change in boys. After adjustment for baseline age and socioeconomic status, boys in the lowest quartile of LINE‐1 methylation experienced annual gains in BMIZ and SKFZ that were 0.06 Z/y (P=0.04) and 0.07 Z/y (P=0.03), respectively, higher than those in the upper three quartiles. There was an inverse, monotonic relation of LINE‐1 methylation with annual change in WCZ (P trend=0.02). DNA methylation was not related to development of adiposity during follow‐up among girls.ConclusionsGlobal DNA methylation was inversely related to development of central adiposity in boys.Grant Funding Source: This study was funded by the Robert Wood Johnson Foundation Research Project Awards. The Bogotá School Children Cohort is currently sponsored by the ASISA Research Fund at the University of Michigan.

Information science instruction and changes in girls' and boy's expectancy and value beliefs: In search of gender-equitable pedagogical practices

In this study, which was situated in the context of information science instruction, data were collected twice using student self-reports to examine the effects of pedagogical practices on changes in boys' and girls' expectancy and value beliefs about computing. Participants were 326 7th-grade students, enrolled in three middle schools that were located in a Greek metropolitan city. At both times boys expressed more positive intrinsic-value beliefs about computing. Teachers' pedagogical practices had effects on students' motivation. All students benefited from practices that highlighted the social benefits and applications of technology. Also, girls benefited from practices that connected information science to other school subjects and boys from practices encouraging social interaction. Findings challenge some assumptions about gender/technology relations and have implications for teaching about technology in a gender-equitable way.

Determinants and reference values of short-term heart rate variability in children

This paper provides age- and sex-specific reference values for short-term heart rate variability (HRV) data in children by time domain and frequency domain methods. Furthermore, HRV determinants will be determined. In 460 children (5-10 years), 5-minute HRV measurements in supine position were undertaken with Polar chest belts. The data were manually edited and processed with time and frequency domain methods. Age, time point, physical activity (accelerometry), physical fitness (cardiopulmonary fitness, upper and lower limb muscular fitness) and body composition (body mass index, fat%, fat and fat-free mass) were analysed as determinants using multiple regression analysis stratified by sex. Sex- and age-specific reference values were produced. Overall, girls had lower HRV. Age-related parasympathetic increases and sympathetic decreases were seen with sometimes age-related year-to-year wave-like changes in boys. The time point of recording had limited influence on HRV. Of the lifestyle related factors, fatness (only 7 % overweight) was not associated with HRV but fat-free mass, physical activity and in particular physical fitness (over and above activity) had a favourable association by increased parasympathetic activity. Future HRV studies in children should consider age, sex and physical fitness.

Some determinants of Stunting in children of Tehran

Some determinants of Stunting in children of Tehran

Peer relationships and depressive symptomatology in boys at puberty.

The physical changes of puberty coincide with an increase in the salience of peer relationships and a growing risk for depression and other forms of psychopathology. Previously, we reported that pubertal tempo, defined as a child's rate of intraindividual change in pubertal status (measured using parent-reported Tanner stages; Marshall & Tanner, 1970), was associated with changes in boys'--but not girls'--depressive symptoms over and above effects explained by pubertal timing (Mendle, Harden, Brooks-Gunn, & Graber, 2010). The present study extends this previous research by examining changes in the quality of peer relationships in the association between individual differences in pubertal development and change in boys' depressive symptoms. Boys (N = 128, M = 9.61 years, SD = 0.70, at Time 1) were recruited from public schools and assessed annually for 4 years. Results from latent growth curve models indicated that earlier pubertal timing and more rapid pubertal tempo were associated with greater decrements in the quality of boys' peer relationships. After accounting for the association between change in peer relationships and depressive symptoms, the direct effects of pubertal timing and tempo on depressive symptoms were no longer significant. These results highlight a multifaceted approach to studying puberty and emphasize how social mechanisms may intersect with biological risk to produce psychological distress.

Can Indoor Swimming Alter Hormones in Boys?

Can Indoor Swimming Alter Hormones in Boys?

Friends and Physical Activity during the Transition from Primary to Secondary School

The study's purpose was to examine whether friendship factors predict discretionary physical activity after the transition to secondary school. Data represent a secondary analysis of the Personal and Environmental Associations with Children's Health Study. Outcomes were minutes of moderate to vigorous physical activity (MVPA) obtained after school (3:30-8:30 p.m.) and for weekends. Data were collected at the end of primary and the start of secondary school. Exposures were self-reported number of friends, friend support for physical activity, and friend sedentary preferences. Change (secondary--primary) was calculated for all variables. Boys' after-school MVPA declined by 16% after the move from primary to secondary school with a 12% decline for girls. Both boys' (24%) and girls' (17%) weekend MVPA increased after the move to secondary school. Regression analysis indicated that an increase in the number of friends between primary and secondary school was associated with increased after-school and weekend MVPA. Inspection of the coefficients indicated that each additional friend was associated with 3.7 more minutes of MVPA after school and 9.8 min of MVPA during the weekend for girls. Similarly, each additional unit on a four-item friend support for physical activity scale was associated with 1.8 more minutes of after-school MVPA and 6.0 more minutes of weekend MVPA among girls. Although friend support was cross-sectionally associated with boys' MVPA during primary school, neither the number of friends nor friend support for physical activity was associated with change in boys' after-school or weekend MVPA. Increased number of friends and friend support for physical activity were associated with increases in girls' MVPA after the move to secondary school. Strategies to foster friend support for physical activity may be important for helping girls be active.