Disinfection by-products effect on swimmers oxidative stress and respiratory damage

Disinfection by-products (DBPs) are generated through the reaction of chlorine with organic and inorganic matter in indoor swimming pools. Different DBPs are present in indoor swimming pools. This study evaluated the effects of different chlorinated formations in oxidative stress and lung damage in 20 swimmers after 40?min of aerobic swimming in 3 indoor pools with different characteristics. Biological samples were collected to measure lung damage (serum-surfactant-associated proteins A and B), oxidative stress parameters (plasma protein carbonylation and malondialdehyde, and whole-blood glutathione oxidation), and swimming exertion values (blood lactate) before and after exercise. Free chlorine and combined chlorine in water, and chlorine in air samples were determined in all the swimming pools. Chlorination as disinfection treatment led to the formation of chloramines in water samples, mainly mono- and dichloramine. However, free chlorine was the predominate species in ultraviolet-treated swimming pool. Levels of total chlorine increased as a function of the swimming activity in chlorinated swimming pools. The lower quality of the installation resulted in a higher content of total chlorine, especially in air samples, and therefore a higher exposure of the swimmer to DBPs. However, the concentration level of chlorinated DBPs did not result in significant variation in serum-surfactant-associated proteins A and oxidative stress parameters in swimmers. In conclusion, the quality of the installation affected the DBPs concentration; however, it did not lead to lung epithelial damage and oxidative stress parameters in swimmers.     

Preschool Teachers’ Implementation of Vocabulary Strategies During Shared Reading: a Comparative Study

Research Findings: Shared reading is reported to be the single best instructional practice for emergent literacy skills. Vocabulary instruction practices implemented during shared reading by both Head Start (HS) teachers and teachers from more affluent private school settings were compared to determine whether there were differences between the 2 groups of teachers in their implementation of research-based practices. HS teachers implemented vocabulary instruction practices during shared reading more often, and chose different words to instruct, than private school teachers. Whereas 78% of HS teachers provided some vocabulary instruction during shared reading, only 59% of private school teachers did so. Among those teachers who provided vocabulary instruction during shared reading, HS teachers used significantly more contextualization strategies for word instruction than private school teachers. These findings suggest that preschool teachers who work with children from high-needs backgrounds use vocabulary instruction during shared reading as a way to bolster children’s vocabularies more frequently than teachers working in private preschools that serve children from more privileged backgrounds. Extratextual language was also compared, and private school teachers had a higher mean length of utterance and type–token ratio than the HS teachers. Practice or Policy: Professional development is recommended for preschool teachers to increase the implementation of best practices for vocabulary instruction during shared reading.     

Interrupted experiences: reflection, listening and negativity in the practice of teaching

This inquiry explores the educative meaning of interruptions or breaks in teacher’s experiences by looking at their role in reflection and listening. Reflection and listening are not only two vital and distinct aspects of teaching, but are also interrelated and as such can serve to productively inform one another. In this context, I develop the notion of negativity of experience to describe the space that opens up when our experience has been in some way interrupted, the space where we dwell between old and new experiences and where new thoughts and ideas emerge. I demonstrate throughout my discussion that it is in this space that listening and reflection take place. To begin, I analyze the works of John Dewey and Donald Schön to take up a few particular aspects of reflective thinking and its relation to the practice of teaching. In this context, I point out similarities and important learning-theoretical differences between the notion of ‘negativity of experience’ and Schön’s notion of ‘messy situations’. The second section examines the role of negativity of experience in listening. Here, I seek to explore ways to include listening in the contemporary discussion on reflective teaching and practice. The inquiry concludes by considering the meaning of reflection, listening and negativity for the education of professional teachers.     

Diverse Approaches to the Diversity of Learning Styles in Teacher Education

The goal of this paper is to present the findings of a new research project on teacher candidates' learning style preferences and the implications thereof for their teaching styles. The researchers utilized two different learning‐style assessment instruments based on Dunn and Dunn's learning style model—one paper and pencil and one online learning style assessment instrument to identify course participants' learning styles. Within the same institution of higher education, the learning style concept was introduced and operationalized in two different ways. Using a combination of quantitative and qualitative approaches, teacher candidates' individual and group learning style profiles and their reflections on their own learning and teaching styles are discussed.     

A survey of pre-service primary teachers' experiences of science in schools

In 1990, a large proportion of third year primary trainee teachers at Victoria College had observed or taught very few or no science lessons during the first two years of their course. The students felt that a lack of content knowledge, a crowded school curriculum, and problems associated with managing resources and equipment, were the main factors contributing to the low level of science being taught in schools. By the end of their third year significantly more students had taught science than after the second year. There was also a change in approach to teaching science with more practical activities being included than previously. The science method unit taught to the students in the third year of their course contributed to this increase. The students considered the hands-on activities in class to have been the most effective aspect of the unit in their preparation for the teaching of primary science. Specializations: children's learning in science, primary teacher education. Specializations: student understanding of biology, evaluation of formal and informal educational settings. Specializations: gender, science and technology, environmental education. Specializations: children's learning in science, language and science.     

Learning to teach science in urban schools

Teaching in urban schools, with their problems of violence, lack of resources, and inadequate funding, is difficult. It is even more difficult to learn to teach in urban schools. Yet learning in those locations where one will subsequently be working has been shown to be the best preparation for teaching. In this article we propose coteaching as a viable model for teacher preparation and the professional development of urban science teachers. Coteaching—working at the elbow of someone else—allows new teachers to experience appropriate and timely action by providing them with shared experiences that become the topic of their professional conversations with other coteachers (including peers, the cooperating teacher, university supervisors, and high school students). This article also includes an ethnography describing the experiences of a new teacher who had been assigned to an urban high school as field experience, during which she enacted a curriculum that was culturally relevant to her African American students, acknowledged their minority status with respect to science, and enabled them to pursue the school district standards. Even though coteaching enables learning to teach and curricula reform, we raise doubts about whether our approaches to teacher education and enacting science curricula are hegemonic and oppressive to the students we seek to emancipate through education. © 2001 John Wiley & Sons, Inc. J Res Sci Teach 38: 941–964, 2001     

Improving Students’ Information Problem-Solving Skills on the Web Through Explicit Instruction and the Use of Customized Search Software

Abstract

Research shows that students face a range of difficulties when using the Internet to solve information problems. Using a quasi-experimental design, we tested a strategy to improve Chilean 10th graders’ skills for information problem solving using the Internet (IPS-I). The intervention was based on a workshop in which students learned IPS-I strategies and solved information problems using a customized Internet search software package. Results showed that members of the experimental group changed their search behavior and improved the quality of their products. However, no correlation between the number of search actions and product quality was found. Based on this, we highlight the potential of combining teaching strategies to improve specific search skills and the use of customized search tools with embedded functionalities that foster good search techniques.