International field experiences: The impact of class,gender and race on the perceptions and experiences of preservice teachers

We explore ways class, gender and race complicate perceptions and experiences of preservice teachers during an international field experience in Honduras. Data were collected over 5 years through observations, group discussions, course assignments, and on-site focus group interviews and post-trip individual interviews. An inductive approach combined with cross-comparative analysis reveal diverse ways class, gender and race shaped and re-shaped preservice teachers' perceptions of self, peers, and host community members. We conclude with a call for international cross-cultural experiences that encourage preservice teachers to critically examine their perspectives, positions in the host community, and learning during study abroad.     

Teachers' approaches towards word problem solving: Elaborating or restricting the problem context

This contribution reports about a seven-month long video-based study in two regular Flemish sixth-grade mathematics classrooms. The focus is on teachers' approaches towards problem solving. In our analysis we distinguished between a paradigmatic-oriented (focus on the mathematical structure) and a narrative-oriented (focus on the contextual aspects of a problem) perspective on the problem-solving process. The findings have highlighted that the word problem-solving lessons were more dominated by a paradigmatic than a narrative approach and that interventions in which the relation between the mathematics structure and the realistic constraints of the problem context is addressed, were rare.     

Weekday–weekend variations in mother-/father–child physical activity and screen time relationship: A cross-sectional study in a random sample of Czech families with 5- to 12-year-old children

This study assessed the associations between these factors in a random sample of Czech families with preschool and school-aged children. A nationally representative sample comprised 185 families with preschool children and 649 families with school-aged children (dyads; both parents and child n?=?365, mother and child n?=?730, and father and child n?=?469). The participants wore Yamax Digiwalker SW-200 pedometers at least four weekdays and both weekend days and completed family logbooks (anthropometric parameters, daily step counts (SC), and screen time (ST)). When a parent (fathers at weekends and mothers both on weekdays and at weekends) achieved 10,000 SC per day, their children were also significantly (OR?=?2.93–6.06, 95% CI?=?2.02–9.26) more likely to meet the daily SC recommendation. On the contrary, the involvement of fathers in organized leisure-time PA reduced their children's odds of meeting the SC recommendation on weekdays (OR?=?0.53, 95% CI?=?0.31–0.89) and at weekends (OR?=?0.41, 95% CI?=?0.24–0.72). The excessive ST of parents at weekends reduced the odds of their children meeting the SC recommendation (mother–child dyads: OR?=?0.44, 95% CI?=?0.26–0.72; father–child dyads: OR?=?0.63, 95% CI?=?0.37–1.06). High levels of parents’ PA contribute to the achievement of the recommended daily PA in children on weekdays and at weekends. Excessive weekend ST of parents reduces their odds of their children achieving the recommended daily PA; however, the influence of parents’ PA on their children’s achieving the recommended daily PA is stronger than the inhibitory effect of ST.     

Carbohydrate mouth rinse does not affect performance during a 60-min running race in women

This study examined the effect of carbohydrate mouth rinsing on endurance running performance in women. Fifteen female recreational endurance runners, who used no oral contraceptives, ran two races of 1-h duration on an indoor track (216-m length) at 18:00 h after an 8-h fast with a 7-days interval between races, corresponding to the 3^rd-10th day of each premenopausal runner’s menstrual cycle, or any day for the postmenopausal runners. In a double-blind random order, participants rinsed their mouth with 25 ml of either a 6.4% carbohydrate (RCHO) or a placebo solution (RP). No fluid was ingested during exercise. Serum 17β-Εstradiol (P = 0.59) and Progesterone (P = 0.35) did not differ between treatments. There was no difference in 1-hour running performance (RCHO: 10,621.88 ± 205.98 m vs. RP: 10,454.00 ± 206.64 m; t = 1.784, P = 0.096). Furthermore, the mean percentage effect (±99%CI) of RCHO relative to RP, 1.67% (?1.1% to 4.4%), and Cohen’s effect size (d = 0.21) support a trivial outcome of RCHO for total distance covered. In conclusion, carbohydrate mouth rinsing did not improve 60-min track running performance in female recreational runners competing in a low ovarian hormone condition, after an 8-h fast and when no fluid was ingested during exercise.     

Middle School Teachers’ Use of Mathematics to Make Sense of Student Solutions to Proportional Reasoning Problems

Mathematics teacher education aims to improve teachers’ use of mathematical knowledge to support teaching and learning, an aspect of pedagogical content knowledge (PCK). In this study, we interviewed teachers to understand how they used mathematics to make sense of student solutions to proportional reasoning problems. The larger purpose was to find accurate ways of categorizing teachers’ ability to do this vital aspect of teaching and thereby to inform assessment, teacher education, and professional development. We conjectured that teachers’ PCK for proportional reasoning could be reliably described in terms of attention to quantitative meanings in story problem contexts and in terms of understanding naïve forms of proportional reasoning. Instead, our findings reveal that individual teachers used a variety of means to make sense of (1) cognitively similar student solutions to different tasks and (2) mathematically related steps of a student solution within a single task. These findings illustrate the complexity of PCK for the topic of proportional reasoning and suggest the limits of what can be inferred about teacher knowledge from teachers’ evaluations of student solutions. We discuss implications for teacher education and assessment.     

Effect of exercise and nasal splinting on static and dynamic measures of nasal airflow

The main aim of this study was to assess the separate and combined effects of exercise and nasal splinting on static and dynamic measures of nasal airflow. In a randomized crossover design, 12 healthy participants (6 men, 6 women) performed static and dynamic spirometric nasal airflow assessment tests, with or without nasal splinting (Breathe-Right?), before and after a maximal oxygen uptake (VO 2max ) treadmill test. At least 7 days later, the V O 2max and nasal airflow tests were repeated. The results showed that the measured variables were not significantly different with and without nasal splinting. We conclude that the absence of significantly enhanced nasal patency observed for nasal splinting and after exercise suggest that these factors have a minimal impact on nasal airflow volume and rate.     

Sprint mechanical differences at maximal running speed: Effects of performance level

ABSTRACT

As the effect of performance level on sprinting mechanics has not been fully studied, we examined mechanical differences at maximal running speed (MRS) over a straight-line 35 m sprint amongst sprinters of different performance levels. Fifty male track and field sprinters, divided in Slow, Medium and Fast groups (MRS: 7.67 ± 0.27 m?s^?1, 8.44 ± 0.22 m?s^?1, and 9.37 ± 0.41 m?s^?1, respectively) were tested. A high-speed camera (250 Hz) recorded a full stride in the sagittal plane at 30–35 m. MRS was higher (p < 0.05) in Fast vs. Medium (+11.0%) and Slow (+22.1%) as well as in Medium vs. Slow (+10.0%). Twelve, eight and seven out of 21 variables significantly distinguished Fast from Slow, Fast from Medium and Medium from Slow sprinters, respectively. Propulsive phase was signi?cantly shorter in Fast vs. Medium (?17.5%) and Slow (?29.4%) as well as in Medium vs. Slow (?14.4%). Fast sprinters had significantly higher vertical and leg stiffness values than Medium (+44.1% and +18.1%, respectively) and Slow (+25.4% and +22.0%, respectively). MRS at 30–35 m increased with performance level during a 35-m sprint and was achieved through shorter contact time, longer step length, faster step rate, and higher vertical and leg stiffness.     

Performance Enhancement and Politicisation of High-Performance Sport: The West German ‘air clyster’ Affair of 1976

While the politicisation of high-performance sport is perceived to represent one of the driving forces behind doping, we know not much how exactly the cold war in sports has affected sporting misconduct in western societies. Therefore, we propose here to distinguish between ideological and institutional politicisation and explicit and implicit acceptance of dubious practices. We apply our framework to analyse the West German ‘air clyster’ affair of 1976 in order to examine to what extent the politicisation of high-performance sport during the cold war affected the search for innovation in performance enhancement. We find that political pressure for improved competitiveness in West German sport had served to create a semi-autonomous high-performance sport sector in West Germany where blurred lines of accountability allowed questionable practices to prosper. While the public despised the use of questionable methods, sportive nationalism served to eclipse dubious practices. West German sport leaders adopted insofar a permissive attitude towards questionable practices as sporting misconduct was not sanctioned. Thus, our results strongly suggest that sport's politicisation during the cold war facilitated the search for performance-increasing methods in western societies.     

When favourites fail: Tournament trophies as reward cues in tennis finals

Abstract

In tournaments in various sports that feature one–on–one competition, the trophy is sometimes prominently displayed near the athletes during the final. Based on recent research on subtle reward cues, we propose that such trophies have the potential to induce choking under pressure in the match favourites, who are known to be most at risk. To test this idea, we analysed real-life tennis performance data (service performance and rally performance) from professional tournaments. While favourites generally outperformed underdogs during rallies, they did not do so in finals in which (a) large amounts of money were at stake and (b) a trophy was on display near the court. These findings support the idea that tournament trophies may distract favourites by continuously reminding them of what is at stake, and via that route may severely thwart their performance.