Transport properties of heterogeneous materials derived from Gaussian random fields: Bounds and Simulation

We investigate the effective conductivity ($\sigma_e$) of a class of amorphous media defined by the level-cut of a Gaussian random field. The three point solid-solid correlation function is derived and utilised in the evaluation of the Beran-Milton bounds. Simulations are used to calculate $\sigma_e$ for a variety of fields and volume fractions at several different conductivity contrasts. Relatively large differences in $\sigma_e$ are observed between the Gaussian media and the identical overlapping sphere model used previously as a `model' amorphous medium. In contrast $\sigma_e$ shows little variability between different Gaussian media.Comment: 15 pages, 14 figure

Intergroup Contact Attitudes Across Peer Networks in School: Selection, Influence, and Implications for Crossâ Group Friendships

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152596/1/cdev13061.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152596/2/cdev13061_am.pd

Positive youth development in swimming: clarification and consensus of key psychosocial assets

The purpose of this study was to gain a more cohesive understanding of the assets considered necessary to develop in young swimmers to ensure both individual and sport specific development. This two stage study involved (a) a content analysis of key papers to develop a list of both psychosocial skills for performance enhancement and assets associated with positive youth development, and (b) in-depth interviews involving ten expert swim coaches, practitioners and youth sport scholars. Five higher order categories containing seventeen individual assets emerged. These results are discussed in relation to both existing models of positive youth development and implications for coaches, practitioners and parents when considering the psychosocial development of young British swimmers

Academic language socialisation in high school writing conferences

This study examines multilingual high school writers’ individual talk with their teachers in two advanced English language development classes to observe how such talk shapes linguistically diverse adolescents’ writing. Addressing adolescent writers’ language socialization through microethnographic discourse analysis, the author argues that teachers’ oral responses during writing conferences can either scaffold or deter students’ socialization into valued ways of using academic language for school writing. She suggests what forms of oral response provide scaffolding and what forms might limit multilingual adolescent learners’ academic literacy. Constructive interactions engaged students in dialogue about their writing, and students included content or phrasing from the interaction in their texts. Unhelpful interactions failed to foster students’ language development in observable ways. Although teachers attempted to scaffold ideas and language, they often did not guide students’ discovery of appropriate forms or points. These interactions represent restrictive academic language socialization: while some students did create academic texts, they learned little about academic language use

Childhood loneliness as a predictor of adolescent depressive symptoms: an 8-year longitudinal study

Childhood loneliness is characterised by children’s perceived dissatisfaction with aspects of their social relationships. This 8-year prospective study investigates whether loneliness in childhood predicts depressive symptoms in adolescence, controlling for early childhood indicators of emotional problems and a sociometric measure of peer social preference. 296 children were tested in the infant years of primary school (T1 5 years of age), in the upper primary school (T2 9 years of age) and in secondary school (T3 13 years of age). At T1, children completed the loneliness assessment and sociometric interview. Their teachers completed externalisation and internalisation rating scales for each child. At T2, children completed a loneliness assessment, a measure of depressive symptoms, and the sociometric interview. At T3, children completed the depressive symptom assessment. An SEM analysis showed that depressive symptoms in early adolescence (age 13) were predicted by reports of depressive symptoms at age 8, which were themselves predicted by internalisation in the infant school (5 years). The interactive effect of loneliness at 5 and 9, indicative of prolonged loneliness in childhood, also predicted depressive symptoms at age 13. Parent and peer-related loneliness at age 5 and 9, peer acceptance variables, and duration of parent loneliness did not predict depression. Our results suggest that enduring peer-related loneliness during childhood constitutes an interpersonal stressor that predisposes children to adolescent depressive symptoms. Possible mediators are discussed

Endoscopic procedures for removal of foreign bodies of the aerodigestive tract: The Bugando Medical Centre experience

<p>Abstract</p> <p>Background</p> <p>Foreign bodies in the aerodigestive tract continue to be a common problem that contributes significantly to high morbidity and mortality worldwide. This study was conducted to describe our own experience with endoscopic procedures for removal of foreign bodies in the aerodigestive tract, in our local setting and compare with what is described in literature.</p> <p>Methods</p> <p>This was a prospective descriptive study which was conducted at Bugando Medical Centre between January 2008 and December 2009. Data were collected using a structured questionnaire and analyzed using SPSS computer software version 15.</p> <p>Results</p> <p>A total of 98 patients were studied. Males outnumbered females by a ratio of 1.1:1. Patients aged 2 years and below were the majority (75.9%). The commonest type of foreign bodies in airways was groundnuts (72.7%) and in esophagus was coins (72.7%). The trachea (52.2%) was the most common site of foreign body's lodgment in the airways, whereas cricopharyngeal sphincter (68.5%) was the commonest site in the esophagus. Rigid endoscopy with forceps removal under general anesthesia was the main treatment modality performed in 87.8% of patients. The foreign bodies were successfully removed without complications in 90.8% of cases. Complication rate was 7.1% and bronchopneumonia was the most common complication accounting for 42.8% of cases. The mean duration of hospital stay was 3.4 days and mortality rate was 4.1%.</p> <p>Conclusion</p> <p>Aerodigestive tract foreign bodies continue to be a significant cause of childhood morbidity and mortality in our setting. Rigid endoscopic procedures under general anesthesia are the main treatment modalities performed. Prevention is highly recommended whereby parents should be educated to keep a close eye on their children and keep objects which can be foreign bodies away from children's reach.</p