Teachers’ and Their Pupils’ Performance on Plant Nutrition: a Comparative Case

Research in Science Education - The research compares teachers’ and their pupils’ performance on plant nutrition. The misconceptions of 89 primary school children from one state school...     

Relations Among the Home Language and Literacy Environment and Children’s Language Abilities: A Study of Head Start Dual Language Learners and Their Mothers

Research Findings: This study explored the relations between Spanish–English dual language learner (DLL) children’s home language and literacy experiences and their expressive vocabulary and oral comprehension abilities in Spanish and in English. Data from Spanish–English mothers of 93 preschool-age Head Start children who resided in central Pennsylvania were analyzed. Children completed the Picture Vocabulary and Oral Comprehension subtests of the Batería III Woodcock–Muñoz and the Woodcock–Johnson III Tests of Achievement. Results revealed that the language spoken by mothers and children and the frequency of mother–child reading at home influenced children’s Spanish language abilities. In addition, the frequency with which children told a story was positively related to children’s performance on English oral language measures. Practice or Policy: The findings suggest that language and literacy experiences at home have a differential impact on DLLs’ language abilities in their 2 languages. Specific components of the home environment that benefit and support DLL children’s language abilities are discussed.     

The dynamic impact characteristics of tennis balls with tennis rackets

Abstract

The dynamic properties of six types of tennis balls were measured using a force platform and high-speed digital video images of ball impacts on rigidly clamped tennis rackets. It was found that the coefficient of restitution reduced with velocity for impacts on a rigid surface or with a rigidly clamped tennis racket. Pressurized balls had the highest coefficient of restitution, which decreased by 20% when punctured. Pressureless balls had a coefficient of restitution approaching that of a punctured ball at high speeds. The dynamic stiffness of the ball or the ball-racket system increased with velocity and pressurized balls had the highest stiffness, which decreased by 35% when punctured. The characteristics of pressureless balls were shown to be similar to those of punctured balls at high velocity and it was found that lowering the string tension produced a smaller range of stiffness or coefficient of restitution. It was hypothesized that players might consider high ball stiffness to imply a high coefficient of restitution. Plots of coefficient of restitution versus stiffness confirmed the relationship and it was found that, generally, pressurized balls had a higher coefficient of restitution and stiffness than pressureless balls. The players might perceive these parameters through a combination of sound, vibration and perception of ball speed off the racket.     

Sex education in Spain: the relevance of teachers’ training and attitudes / Educación sexual en España: importancia de la formación y las actitudes del profesorado

Abstract

This research has two main aims: a) the study of Spanish teachers’ training and attitudes towards sex education, as well as the delivery of this subject in classrooms, while also exploring the existence of differences according to personal and professional characteristics; and b) to examine the association between teachers’ training and attitudes, and the extent to which these variables predict the delivery of sex education. A total of 3,695 Infant, Primary, Secondary and High school teachers (66.1% women, 33.9% men) throughout the country completed a voluntary online questionnaire that inquired about their training and attitudes towards sex education, their delivery or non-delivery of this subject in classrooms, and other personal and professional characteristics. Analyses indicate that participants show positive attitudes towards sex education, but that 43.3% are not trained in this issue, and 48.6% do not teach it at school. Some significant differences by sex, educational stage and type of school have been found. In addition, trained teachers show more positive attitudes to sex education. Finally, having more positive attitudes and, to a lesser extent, having prior training, positively predicts the delivery of sex education. These results highlight the importance of reviewing and improving teachers’ training on sexuality and sex education, with particular emphasis on attitudinal contents.     

How should cultural diversity be measured? An application using the French publishing industry

Despite the lack of a clear definition of the concept, “cultural diversity” has remained a core issue for more than a decade (WTO, UNESCO, etc.). The aim of this paper is to begin to fill this gap. We argue that cultural diversity is a multi-dimensional concept and that accurate metrics must rely on three criteria: variety, balance and disparity. We also stress that supplied and consumed diversity have to be distinguished. We apply this set of multiple measures of diversity to publishing data for France over the period 1990–2003. Our main result is that the situation of the publishing industry in terms of cultural diversity is highly dependent on the dimension considered. Hence, diversity increases when variety is the sole consideration, whereas taking balance or disparity into account leads to the opposite conclusion. This issue raises a series of questions about the use of diversity measures in a policy debate concerned with furthering cultural diversity.

Does the long tail really favor small publishers?

A growing body of literature is devoted to testing the reality of the “long-tail” phenomenon. This literature is mostly, if not exclusively, focused on the impact of Internet on the distribution of sales by product. However, the long tail also raises the issue of a possible change in the usual market structure of cultural industries: an oligopoly with a competitive fringe. To our knowledge, no paper addresses the following question: If the long-tail effect does exist, is it of more benefit to small or dominant publishers? The aim of this paper was to address this issue in the context of the French publishing industry. Our main findings are as follows: (1) the market concentration of the French book industry is lower online than offline and (2) the difference in concentration between the two channels of distribution tended to widen over the period 2004–2010. Strategies adopted by leading publishers on the Web do not allow them to maintain the market share obtained with bricks-and-mortar retailers. Furthermore, we show that the market share lost by dominant firms is captured by small publishers online and by medium-sized publishers in conventional stores.