Sexual dimorphism of the femoral neck during the adolescent growth spurt: a structural analysis

Before puberty, there are only small sex differences in body shape and composition. During adolescence, sexual dimorphism in bone, lean, and fat mass increases, giving rise to the greater size and strength of the male skeleton. The question remains as to whether there are sex differences in bone strength or simply differences in anthropometric dimensions. To test this, we applied hip structural analysis (HSA) to derive strength and geometric indices of the femoral neck using bone densitometry scans (DXA) from a 6-year longitudinal study in Canadian children. Seventy boys and sixty-eight girls were assessed annually for 6 consecutive years. At the femoral neck, cross-sectional area (CSA, an index of axial strength), subperiosteal width (SPW), and section modulus (Z, an index of bending strength) were determined, and data were analyzed using a hierarchical (random effects) modeling approach. Biological age (BA) was defined as years from age at peak height velocity (PHV). When BA, stature, and total-body lean mass (TB lean) were controlled, boys had significantly higher Z than girls at all maturity levels (P < 0.05). Controlling height and TB lean for CSA demonstrated a significant independent sex by BA interaction effect (P < 0.05). That is, CSA was greater in boys before PHV but higher in girls after PHV The coefficients contributing the greatest proportion to the prediction of CSA, SPW, and Z were height and lean mass. Because the significant sex difference in Z was relatively small and close to the error of measurement, we questioned its biological significance. The sex difference in bending strength was therefore explained by anthropometric differences. In contrast to recent hypotheses, we conclude that the CSA-lean ratio does not imply altered mechanosensitivity in girls because bending dominates loading at the neck, and the Z-lean ratio remained similar between the sexes throughout adolescence. That is, despite the greater CSA in girls, the bone is strategically placed to resist bending; hence, the bones of girls and boys adapt to mechanical challenges in a similar way. (C) 2004 Elsevier Inc. All rights reserved.

Use of pulse transit time to distinguish respiratory events from tidal breathing in sleeping children

Study objectives: Currently, esophageal pressure monitoring is the "gold standard" measure for inspiratory efforts, hut its invasive nature necessitates a better tolerated and noninvasive method to be used on children. Pulse transit time (PTT) has demonstrated its potential as a noninvasive surrogate marker for inspiratory efforts. The principle velocity determinant of PTT is the change in stiffness of the arterial wall and is inversely correlated to BP. Moreover, PTT has been shown to identify changes in inspiratory effort via the BP fluctuations induced by negative pleural pressure swings. In this study, the capability of PTT to classify respiratory, events during sleep as either central or obstructive in nature was investigated. Setting and participants: PTT measure was used in adjunct to routine overnight polysomnographic studies performed on 33 children (26 boys and 7 girls; mean +/- SD age, 6.7 +/- 3.9 years). The accuracy of PTT measurements was then evaluated against scored corresponding respiratory events in the polysomnography recordings. Results: Three hundred thirty-four valid respiratory events occurred and were analyzed. One hundred twelve obstructive events (OEs) showed a decrease in mean PTT over a 10-sample window that had a probability of being correctly ranked below the baseline PTT during tidal breathing of 0.92 (p < 0.005); 222 central events (CEs) showed a decrease in the variance of PTT over a 10-sample window that had a probability of being ranked below the baseline PTT of 0.94 (p < 0.005). This indicates that, at a sensitivity of 0.90, OEs can be detected with a specificity of 0.82 and CEs can be detected with a specificity of 0.80. Conclusions: PTT is able to categorize CEs and OEs accordingly in the absence of motion artifacts, including hypopneas. Hence, PTT shows promise to differentiate respiratory, events accordingly and can be an important diagnostic tool in pediatric respiratory sleep studies.< 0.005); 222 central events (CEs) showed a decrease in the variance of PTT over a 10-sample window that had a probability of being ranked below the baseline PTT of 0.94 (p < 0.005). This indicates that, at a sensitivity of 0.90, OEs can be detected with a specificity of 0.82 and CEs can be detected with a specificity of 0.80. Conclusions: PTT is able to categorize CEs and OEs accordingly in the absence of motion artifacts, including hypopneas. Hence, PTT shows promise to differentiate respiratory, events accordingly and can be an important diagnostic tool in pediatric respiratory sleep studies.');"

Impact of ethnicity upon body composition assessment in Sri Lankan Australian children

Objectives: Obesity is a disease with excess body fat where health is adversely affected. Therefore it is prudent to make the diagnosis of obesity based on the measure of percentage body fat. Body composition of a group of Australian children of Sri Lankan origin were studied to evaluate the applicability of some bedside techniques in the measurement of percentage body fat. Methods: Height (H) and weight (W) was measured and BMI (W/H-2) calculated. Bioelectrical impedance analysis (BIA) was measured using tetra polar technique with an 800 mu A current of 50 Hz frequency. Total body water was used as a reference method and was determined by deuterium dilution and fat free mass and hence fat mass (FM) derived using age and gender specific constants. Percentage FM was estimated using four predictive equations, which used BIA and anthropometric measurements. Results: Twenty-seven boys and 15 girls were studied with mean ages being 9.1 years and 9.6 years, respectively. Girls had a significantly higher FM compared to boys. The mean percentage FM of boys (22.9 +/- 8.7%) was higher than the limit for obesity and for girls (29.0 +/- 6.0%) it was just below the cut-off. BMI was comparatively low. All but BIA equation in boys under estimated the percentage FM. The impedance index and weight showed a strong association with total body water (r(2)= 0.96, P < 0.001). Except for BIA in boys all other techniques under diagnosed obesity. Conclusions: Sri Lankan Australian children appear to have a high percentage of fat with a low BMI and some of the available indirect techniques are not helpful in the assessment of body composition. Therefore ethnic and/or population specific predictive equations have to be developed for the assessment of body composition, especially in a multicultural society using indirect methods such as BIA or anthropometry.

Tympanometric findings in children at school entry: A normative study

This study presents tympanometric normative data for Australian children at school entry in view of the lack of age-specific population-based data for this group. Participants were 327 children (164 boys, 163 girls) aged between 5 and 6 years, who had no history of middle ear infection, and passed pure-tone screening at 20 dB HL. Normative values for static admittance (SA), ear canal volume (ECV), tympanometric peak pressure, tympanometric width (TW) and tympanometric gradient were established. Based on these normative data, the use of the ASHA (1997) guidelines for medical referral, in which ECV > 1.0 ml in the presence of a flat tympanogram, SA < 0.3 ml, or TW > 200 daPa may not provide the best criteria for Australian children aged between 5 and 6 years. If SA < 0.3 ml were used instead of SA < 0.16 ml, a greater proportion of Australian children would have failed tympanometry, thus increasing the false alarm rate.

Measuring the ability of school children with a history of otitis media to understand everyday speech

The present study compared the ability of school-aged children with and without a history of otitis media (OM) to understand everyday speech in noise using the University of Queensland Understanding of Everyday Speech Test (UQUEST). Participants were 484 children (246 boys, 238 girls) attending Grade 3 (272, mean age = 8.25 yr., SD = 0.43) and Grade 4 (212, mean age = 9.28 yr., SD = 0.41) at 19 primary schools in Brisbane metropolitan and Sunshine Coast schools. Children selected for inclusion were native speakers of English with normal hearing on the day of testing and had no reported physical or behavioral impairments. The children were divided into three groups according to the number of episodes of OM since birth. The results showed no significant differences in speech scores across the participant groups. However, a significant difference in mean speech scores was found across the grades and the noise conditions. Although children with a history of OM performed equally well at a group level when compared to the controls, they exhibited a large range of abilities in speech comprehension within the same group.

Screening for posttraumatic stress disorder in children after accidental injury

OBJECTIVE. Children who have experienced an accidental injury are at increased risk of developing posttraumatic stress disorder. It is, therefore, essential that strategies are developed to aid in the early identification of children at risk of developing posttraumatic stress disorder symptomatology after an accident. The aim of this study was to examine the ability of the Child Trauma Screening Questionnaire to predict children at risk of developing distressing posttraumatic stress disorder symptoms 1 and 6 months after a traumatic accident. METHODS. Participants were 135 children (84 boys and 51 girls; with their parents) who were admitted to the hospital after a variety of accidents, including car- and bike-related accidents, falls, burns, dog attacks, and sporting injuries. The children completed the Child Trauma Screening Questionnaire and the Children's Impact of Events Scale within 2 weeks of the accident, and the Anxiety Disorders Interview Schedule for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Child Version, was conducted with the parents to assess full and subsyndromal posttraumatic stress disorder in their child 1 and 6 months after the accident. RESULTS. Analyses of the results revealed that the Child Trauma Screening Questionnaire correctly identified 82% of children who demonstrated distressing posttraumatic stress disorder symptoms (9% of sample) 6 months after the accident. The Child Trauma Screening Questionnaire was also able to correctly screen out 74% of children who did not demonstrate such symptoms. Furthermore, the Child Trauma Screening Questionnaire outperformed the Children's Impact of Events Scale. CONCLUSIONS. The Child Trauma Screening Questionnaire is a quick, cost-effective and valid self-report screening instrument that could be incorporated in a hospital setting to aid in the prevention of childhood posttraumatic stress disorder after accidental trauma.

Physical activity patterns of Singaporean adolescents

The purpose of this study was to document the level of physical activity and sedentary behavior in a representative sample of Singaporean adolescents. A random sample of 1,827 secondary school students from six secondary schools (929 boys, 898 girls, mean age 14.9 +/- 1.2 yr) completed the Three-Day Physical Activity Recall (3DPAR) self-report instrument. Approximately 63% of Singaporean high school students met current guidelines requiring 60 min of moderate to vigorous physical activity daily. Just over half (51.6%) met the guideline calling for regular vigorous physical activity. Across all grade levels, boys were consistently more active than girls. More than 70% of Singaporean high school students exceeded the recommended 2 hours per day of electronic media use. Collectively, these findings suggest that a significant proportion of Singaporean adolescents are not sufficiently active and are in need of programs to promote physical activity and decrease sedentary behavior.

Pedagogies and critical reflection: key understandings for transformative gender justice

It is widely acknowledged that quality pedagogy is central to improving the educational outcomes of all students. In improving the social and academic outcomes of boys, and more specifically disengaged boys, the productive pedagogies model has been presented as a way forward. In terms of drawing on this model in socially just ways; to facilitate a broadening, rather than reinscribing of boys' narrow constructions of gender identity, this paper illustrates the imperative of teachers interacting with key feminist understandings of masculinity. Organized around the four dimensions of productive pedagogy, the paper draws on ( predominantly Australian-based) seminal work in the sphere of masculinities and schooling to discuss key strategies and initiatives for improving boys' educational outcomes. Against this backdrop, the paper demonstrates the importance of two principle understandings. The first relates to teachers understanding masculinity through feminist lenses, as constructed, regulated and maintained through inequitable social processes and the second relates to teachers understanding pedagogy as critical and transformative practice. These understandings are presented as vital to enabling gender justice.

Avaliação Comparativa da Contenção de Molares Superiores Distalizados Realizada por Meio da Placa Lábio-Ativa ou Aparelho Extrabucal

O objetivo deste estudo foi comparar cefalometricamente os efeitos dentários promovidos pelo aparelho extrabucal e com a placa lábio-ativa, instalados para a contenção dos molares superiores distalizados previamente com a placa de Cetlin associada ao aparelho extrabucal. A amostra consistiu de 40 telerradiografias em norma lateral, obtidas de 20 pacientes, sendo 6 do sexo masculino e 14 do sexo feminino, com idade média de 11 anos e 7 meses, tratados por um período médio de 14 meses e 10 dias. Após a distalização, que foi feita com a placa de Cetlin associada ao aparelho extrabucal cérvico-occipital, estes pacientes foram divididos aleatoriamente em dois grupos, onde o grupo AEB utilizou o próprio aparelho extrabucal de uso noturno e o grupo PLA utilizou uma placa lábio-ativa superior em período integral, ambos os aparelhos para conter os primeiros molares superiores distalizados durante a fase de alinhamento e nivelamento dentários. Após a análise estatística, verificou-se que no grupo AEB os molares superiores apresentaram apenas uma inclinação para mesial em média de 8,220 . Já os incisivos superiores inclinaram para lingual, em média, 3,330. No grupo PLA, os molares apresentaram extrusão de, em média, 1,82 mm; mesialização de 3,14 mm; e inclinação para mesial de 8,320; já os incisivos inclinaram para lingual 5,780, em média. Ao comparar os resultados dos grupos entre si, verificou-se que não houve diferença estatisticamente significante entre os aparelhos utilizados. Portanto, tanto o aparelho extrabucal, como a placa lábio-ativa apresentaram-se eficazes para a contenção dos molares superiores distalizados durante as fases de alinhamento e nivelamento dentários.

AVALIAÇÃO TOMOGRÁFICA DA INCLINAÇÃO E DAS TÁBUAS ÓSSEAS VESTIBULAR E LINGUAL DE INCISIVOS NO TRATAMENTO DA CLASSE II DIVISÃO 1 COM O APARELHO FORSUS®

O objetivo deste estudo prospectivo foi avaliar os efeitos do aparelho Forsus® nos incisivos centrais superiores e inferiores. A amostra constituiu-se de 22 tomografias computadorizadas de 11 pacientes (sexo masculino e feminino) idade média de 15,8 anos com má oclusão de Classe II que foram tratados com o aparelho Forsus® na clínica do programa de pós-graduação em Odontologia, área de concentração Ortodontia, da Universidade Metodista de São Paulo. As tomografias foram obtidas em dois momentos T1 (final de nivelamento e antes da instalação do Forsus® e T2 (remoção do Forsus®). Para avaliar a distância do ápice até a tábua óssea, as imagens a serem examinadas foram obtidas com o auxílio do viewer do próprio i-CAT® , o iCATVision® e examinadas com o CorelDRAW X5® já para as medidas cefalométricas IMPA e 1.PP as imagens cefalométricas ortogonais foram obtidas em proporção 1:1 com auxílio do software Dolphin 3D® (Dolphin Imaging and Management Solutions, Chatsworth, EUA) e em seguida examinadas com o software Radiocef Studio 2 (Radio Memory, Belo Horizonte, Brasil). Para a obtenção do erro intra-examinador foi feito o teste t de Student pareado para o erro sistemático e a fórmula de DAHLBERG para estimar a ordem de grandeza dos erros casuais e na análise estatística dos resultados utilizou-se: o teste t para a determinação das diferenças entres as fases de observação e o teste de correlação de Pearson para avaliar a correlação entres as alterações. Observou-se: um aumento significativo (p<0,05) tanto no IMPA quanto no 1.PP, aproximação do ápice dos incisivos inferiores da tábua óssea lingual, aproximação do ápice dos incisivos superiores da tábua óssea vestibular, uma correlação negativa muito forte entre o IMPA e a distância do ápice do incisivo até a tábua óssea lingual e uma correlação negativa moderada entre 1.PP e a distância do ápice do incisivo até a tábua óssea vestibular. Sendo assim o aparelho Forsus® no tratamento da Classe II teve como efeito: vestibularização significativa dos incisivos centrais inferiores, uma verticalização significativa dos incisivos centrais superiores, aproximação do ápice dos incisivos inferiores da cortical óssea lingual e aproximação do ápice dos incisivos superiores da cortical óssea vestibular.

Schoolgirls in a rural context

It is proposed that, for rural secondary schoolgirls, school is a site of contestation. Rural girls attempt to `use' school as a means of resisting traditional patriarchal definitions of a `woman's place'. In their efforts, the girls are thwarted by aspects of the school itself, the behaviour and attitudes of the boys in school, and also the `careers advice' which they receive. It is argued that the girls perceive school as being of greater importance to them than is the case for the boys, and that these gender differentiated perceptions are related to the `social' lives of the girls and boys, and also to their future employment prospects. Unlike the boys, the girls experience considerable restrictions concerning these two areas. This theory was grounded in an ethnographic study which was conducted in and around a village in a rural county in England. As well as developing the theory through ethnography, the thesis contains tests of certain hypotheses generated by the theory. These hypotheses relate to the gender differentiated perspectives of secondary school pupils with regard to the areas of school itself, life outside school, and expectations for the future. The quantitative methods used to test these hypotheses confirm that there is a tendency for girls to be more positively orientated to school than the boys; to feel less able to engage in preferred activities outside school time than the boys, and also to be more willing to move away from the area than the boys. For comparative purposes these hypotheses were tested in two other rural locations and the results indicate the need for further research of a quantitative kind into the context of girls' schooling in such locations. A critical review of literature is presented, as is a detailed discussion of the research process itself.

"No one said girls could do engineering":a fresh look at an old problem

Previous work has drawn attention to what, in many respects, appears to be an insurmountable problem, the lack of women and girls in engineering. The debate about why young women are not attracted to engineering mostly focuses around issues of gender, with the profession stereotypically perceived as being more suitable for men. In seeking to investigate why this should be the case a participatory research approach was adopted in which two 17 year old female High School students were employed to interview their peers about their perceptions of engineering as a career. This paper presents some of the emergent findings of this research. In total twenty teenage girls from two city centre Schools were interviewed. The two teenage researchers developed the questions themselves, focusing on issues they identified as being important factors informing girls’ views of engineering. This approach provided a ‘new’ perspective – looking at the topic through the eyes of the target sample group. By drawing attention to some of the issues around gender and engineering, this paper contributes to current debates in this area – in doing so it provides a fresh look at an old problem and offers some workable solutions for ‘how to get more girls into engineering’.

The impact of a family home-learning program on levels of parental/caregiver efficacy

This study sought to determine if participation in a home education learning program would impact the perceived levels of parental self-efficacy of parents/caregivers who participate in the completion of home-learning assignments and increase their levels of home-learning involvement practices. Also, the study examined the relationship between the parental involvement practice of completing interactive home-learning assignments and the reading comprehension achievement of first grade students. A total of 146 students and their parents/caregivers representing a convenience sample of eight first grade classes participated in the study. Four classes (n=74) were selected as the experimental group and four classes (n=72) served as the control group. There were 72 girls in the sample and 74 boys and the median age was 6 years 6 months. The study employed a quasi-experimental research design utilizing eight existing first grade classes. It examined the effects of a home-learning support intervention program on the perceived efficacy levels of the participating parents/caregivers, as measured by the Parent Perceptions of Parent Efficacy Scale (Hoover-Dempsey, Bassler, & Brissie, 1992) administered on a pre/post basis. The amount and type of parent involvement in the completion of home assignments was determined by means of a locally developed instrument, the H.E.L.P. Parent Involvement Home-learning Scale, administered on a pre/post basis. Student achievement in reading comprehension was measured via the reading subtest of the Brigance, CIB-S pre and post. The elementary students and their parents/caregivers participated in an interactive home-learning intervention program for 12 weeks that required parent/caregiver assistance. Results revealed the experimental group of parents/caregivers had a significant increase in their levels of perceived self-efficacy, p<.001, from the pre to post, and also had significantly increased levels of parental involvement in seven home-learning activities, p<.001, than the control group parents/caregivers. The experimental group students demonstrated significantly higher reading levels than the control group students, p<.001. This study provided evidence that interactive home-learning activities improved the levels of parental self-efficacy and parental involvement in home-learning activities, and improved the reading comprehension of the experimental group in comparison to the control.

The effects of the ethic of care in an all-boys school from 1903 to 1974

Nel Noddings’ 1984 publication, Caring: A Feminine Approach to Ethics and Moral Education was the first formal introduction of the concept of an “ethic of care”. It is a concept that stresses the importance of compassion in any relationship. For the purpose of this dissertation, the ethic of care was studied in a specific educational community. ^ This research focused on the role of care ethics in a secondary school (The Ransom School for Boys) from 1903 to 1974. The researcher identified this school as one that operated with an ethic of care and collected and analyzed data from historical school documents as well as from 60–90 minute individual interviews with six alumni, five retired faculty, and two administrators. ^ The case study addressed how students and faculty experienced care ethics within the school and how it has been maintained throughout the adult lives of alumni. An a priori coding rubric was used to examine the presence of care ethics at the Ransom School for Boys and in the adult lives of its alumni. This rubric was generated using information taken from the literature review and encompasses 36 different words to identify the presence of care ethics. ^ The primary research question was: How have alumni incorporated care ethics into their personal and professional lives? Secondary questions included: (1) How did the ethic of care present itself over the span of 71 years? (2) Was character education part of the formal curriculum at the Ransom School? (3) Was character education part of the hidden curriculum at the Ransom School? (4) Did the presence of care ethics support the values being taught in the home? ^ While there has been research done on the importance of care ethics in an educational institution, the research is void of direct evidence associated with care ethics in a school community, specifically, an all-boys, private school. Through deductive analysis, care ethics was found to be present and utilized at the school. The interviews and historical documents suggested that moral education was an integral part of the informal curriculum and helped to integrate the ethic of care within the community.^

Children's learning of anxiety sensitivity : a preliminary study using a sample of youths referred for anxiety disorders

The purpose of the present study was to examine the origins of anxiety sensitivity (AS) by assessing youths' learning experiences in relation to their AS symptoms and anxiety symptoms. Participants were 33 youths between 7 to 13 years old (M = 9.39 years, SD = 2.01). Youths were assessed using a structured interview and self-report measures. Chi-square analyses revealed no statistically significant differences in the proportions of boys vs. girls, Hispanic vs. non-Hispanic, and married vs. non-married. Pearson correlation analyses revealed that youths' AS learning experiences were significantly related to youths' AS and to youths' anxiety symptoms scores. Partial correlations between youths' learning experiences associated with AS symptoms in relation to AS scores controlling for anxiety symptoms effects were statistically significant. Findings were consistent with theory and suggest that learning mechanisms may be involved in AS acquisition and maintenance. The findings' implications are discussed regarding possible learning experiences' role in the development of AS.