Stability of Core Language Skill from Early Childhood to Adolescence: A Latent Variable Approach

This four‐wave prospective longitudinal study evaluated stability of language in 324 children from early childhood to adolescence. Structural equation modeling supported loadings of multiple age‐appropriate multisource measures of child language on single‐factor core language skills at 20 months and 4, 10, and 14 years. Large stability coefficients (standardized indirect effect = .46) were obtained between language latent variables from early childhood to adolescence even when accounting for child nonverbal intelligence and social competence and maternal verbal intelligence, education, speech, and social desirability. Stability coefficients were similar for girls and boys. Stability of core language skill was stronger from 4 to 10 to 14 years than from 20 months to 4 years, so early intervention to improve lagging language is recommended.     

Beyond Consultation: A New Model for Librarian's Office Hours

ABSTRACT

Given the many changes in our students and their study and research practices, libraries are finding it necessary to seek new ways to reach these students. The Undergraduate Library at the University of Illinois at Urbana-Champaign created a new model to do so. Librarian's Office Hours are a hybrid of reference and instructional services that fulfill the dual purposes of meeting the needs of term paper research counseling and library workshops. This article discusses the strategies involved in the creation and implementation of this service and examines suggestions for the future of such a service.     

Citizenship Education: An empirical study of policy,practices and outcomes

This article reports on a comparative study of civic education in six countries-Britain, the USA, Germany, Denmark, the Netherlands and Australia. Differing policies and practices with respect to citizenship education among the six Western democracies were found to be associated with different patterns of adolescent student political attitudes and perceptions. In those contexts in which civic education includes political content and opportunities for students to explore and express opinions on public policy issues, and to engage in decision-making, young people (ages 15-19) appear to be more interested in the political arena than in those contexts in which they do not have such experiences.     

Limit analysis of flow through conical converging dies

A variety of mathematical models may be used to analyse plastic deformation during a metal-forming process. One of these methods—limit analysis—places the estimate of required power between an upper bound and a lower bound. The upper and lower bound analyses are designed so that the actual power or forming stress requirement is less than that predicted by the upper bound and greater than that predicted by the lower bound. Finding a lower upper bound and a higher lower bound reduces the uncertainty of the actual power requirement. Upper and lower bounds will permit the determination of such quantities as required forces, limitations on the process, optimal die design, flow patterns, and prediction and prevention of defects.Fundamental to the development of both upper bound and lower bound solutions is the division of the body into zones. For each of the zones there is written either a velocity field (upper bound) or a stress field (lower bound). A better choice of zones and fields brings the calculated values closer to actual values.In the present work, both upper and lower bound solutions are presented for axisymmetric flow through conical converging dies. For the upper bound triangular velocity fields have been solved and compared to previously published work on spherical velocity fields. It is found that each type provides a lower solution over a part of the range of process variables. A previously published lower bound solution for axisymmetric flow is refined.     

Proportionnalité et Pourcentage Chez des Apprentis Vendeurs. Réflexion sur la Relation Mathématiques / Réalité dans une Formation 'en Alternance'

This article presents the results of a research study conducted with apprentices in order to examine the double hypothesis that vocational training incorporating work placement gives the opportunity to construct authentic situations out of the everyday practices of students and that these situations allow students to improve their understanding of mathematical problems. After analysis of workplace situations had shown that the only mathematical concept used by apprentices was that of proportionality applied to percentage calculations, we first analysed the way in which students at several levels handled this idea of percentage. We then devised an experimental framework in order to help the apprentices to transfer their knowledge. RéSUMé: Cet article présente les résultats d'une recherche menée avec des apprentis vendeurs afin de vérifier la double hypothèse qu'un enseignement professionnel en alternance donne l'opportunité de construire des situations authentiques, à partir des pratiques quotidiennes des élèves et que ces situations permettent aux élèves d'améliorer leur compréhension des problèmes mathématiques. L'analyse des situations de travail ayant montré que le seul concept mathématique dont les apprentis ont l'usage est le concept de proportionnalité appliqué aux calculs de pourcentage, nous avons d'abord analysé le comportement d'élèves de plusieurs niveaux face à cette notion de pourcentage. Nous avons ensuite mis en place un dispositif expérimental afin d'aider les apprentis à transférer leurs connaissances. This revised version was published online in July 2006 with corrections to the Cover Date.     

富有特色的“集体家书”─—五邑的侨刊乡讯

江门五邑是全国著名侨乡,众多的侨刊乡讯是其一大特色。文章介绍了它的历史发展及鲜明特色,分析了其长盛不衰的奥秘所在。     

Practical precooling: effect on cycling time trial performance in warm conditions

The purpose of this study was to compare the effects of two practical precooling techniques (skin cooling vs. skin + core cooling) on cycling time trial performance in warm conditions. Six trained cyclists completed one maximal graded exercise test (VO2(peak) 71.4 +/- 3.2 ml x kg(-1) x min(-1)) and four approximately 40 min laboratory cycling time trials in a heat chamber (34.3 degrees C +/- 1.1 degrees C; 41.2% +/- 3.0% rh) using a fixed-power/variable-power format. Cyclists prepared for the time trial using three techniques administered in a randomised order prior to the warm-up: (1) no cooling (control), (2) cooling jacket for 40 min (jacket) or (3) 30-min water immersion followed by a cooling jacket application for 40 min (combined). Rectal temperature prior to the time trial was 37.8 degrees C +/- 0.1 degrees C in control, similar in jacket (37.8 degrees C +/- 0.3 degrees C) and lower in combined (37.1 degrees C +/- 0.2 degrees C, P < 0.01). Compared with the control trial, time trial performance was not different for jacket precooling (-16 +/- 36 s, -0.7%; P = 0.35) but was faster for combined precooling (-42 +/- 25 s, - .8%; P = 0.009). In conclusion, a practical combined precooling strategy that involves immersion in cool water followed by the use of a cooling jacket can produce decrease in rectal temperature that persist throughout a warm-up and improve laboratory cycling time trial performance in warm conditions.