Combined metabolic gas analyser and dGPS analysis of performance in cross-country skiing

The purpose of this study was to provide a more detailed analysis of performance in cross-country skiing by combining findings from a differential global positioning system (dGPS), metabolic gas measurements, speed in different sections of a ski-course and treadmill threshold data. Ten male skiers participated in a freestyle skiing field test (5.6 km), which was performed with dGPS and metabolic gas measurements. A treadmill running threshold test was also performed and the following parameters were derived: anaerobic threshold, threshold of decompensated metabolic acidosis, respiratory exchange ratio = 1, onset of blood lactate accumulation and peak oxygen uptake (VO2peak). The combined dGPS and metabolic gas measurements made detailed analysis of performance possible. The strongest correlations between the treadmill data and final skiing field test time were for VO2peak (l x min(-1)), respiratory exchange ratio = 1 (l x min(-1)) and onset of blood lactate accumulation (l x min(-1)) (r = -0.644 to - 0.750). However, all treadmill test data displayed stronger associations with speed in different stretches of the course than with final time, which stresses the value of a detailed analysis of performance in cross-country skiing. Mean oxygen uptake (VO2) in a particular stretch in relation to speed in the same stretch displayed its strongest correlation coefficients in most stretches when VO2 was presented in units litres per minute, rather than when VO2 was normalized to body mass (ml x kg(-1) x min(-1) and ml x min(-1) x kg(-2/3)). This suggests that heavy cross-country skiers have an advantage over their lighter counterparts. In one steep uphill stretch, however, VO2 (ml x min(-1) x kg(-2/3)) displayed the strongest association with speed, suggesting that in steep uphill sections light skiers could have an advantage over heavier skiers.     

Evaluation of the use of Funori for consolidation of powdering paint layers in wall paintings

Funori is a polysaccharide-based adhesive extracted from seaweeds and is generally used in the conservation of easel paintings for the consolidation of matte paint. It is appreciated since it does not change the optical properties of the consolidated materials and its mechanical properties do not change with ageing. Because of these characteristics, this research focused on the evaluation of Funori as a suitable material for the consolidation of powdering paint layers in wall paintings. Tests were carried out where Funori was applied onto painted plaster replicas, which were then artificially aged and investigated in order to evaluate the material's behaviour according to the specific properties and conditions of wall paintings. The effectiveness of the consolidation was evaluated from the point of view of adhesive power, as well as the interactions of Funori with some physical properties of the consolidated painting, such as colour and water vapour permeability and, therefore, its resistance to accelerated ageing and biological colonization. In addition, the behaviour of Funori applied on plasters contaminated with soluble salts, a frequent condition in wall paintings, was also evaluated.     

Meeting Goals and Confronting Conflict: Children's Changing Perceptions of Social Comparison

It was proposed that previously observed grade-related changes in children's social comparison behavior could be explained by the changing goals and meanings children assign to this behavior. Specifically, it was suggested that, as children progress through the school system, they become increasingly aware of the negative and positive aspects of social comparison and adjust their behavior in response to this awareness, as well as to increasingly salient self-evaluation goals. To examine these propositions, 106 elementary school children were observed in their classrooms and interviewed once a year for 3 years. Consistent with previous research, overt forms of social comparison were most frequent among younger children, whereas subtle forms of social comparison were most frequent among older children. Furthermore, with increasing grade children were likely to view overt forms of social comparison negatively and subtle forms as useful in meeting self-evaluation goals. Additional analyses revealed little association between perceptions of social comparison and actual social comparison behavior, except that perceiving subtle social comparison as useful for self-evaluative goals predicted engagement in such behavior 2 years later.     

Competitive comparison in music: influences upon self-efficacy beliefs by gender

This study profiles gender differences in instrumental performance self-efficacy perceptions of high school students (N?=?87) over the course of a three-day orchestra festival in which students competed against one another for rank-based seating and then rehearsed and performed as a group. Reported self-beliefs rose significantly for the sample over the course of the festival. Self-efficacy beliefs of females were significantly lower than those of males before the seating audition and first rehearsal, but were no longer different by the midpoint of the festival. Survey free-response data were coded according to Bandura's (1997 Bandura, A. 1997. Self-efficacy: The Exercise of Control. New York: W. H. Freeman. [Google Scholar]) four sources of self-efficacy. A 52% drop in the frequency of student comments regarding competitive comparison appeared at the same point in which female self-efficacy beliefs were no longer different from those of males. Results support past research to suggest that males and females may respond differently to rank-based competition versus social support.     

Preferences for Various Learning Environments: Teachers' and Parents' Perceptions

In the last ten years, a number of innovations, mainly inspired by constructivist notions of learning, have been introduced at various levels of the Dutch educational system. However, constructivist learning environments are rarely implemented. Teachers tend to stick to expository and structured learning environments. This consistent finding requires research in order to gain insight into teachers' preferences for learning environments and to determine the factors that support and impede the realization of these learning environments. Regarding the influence of social backgrounds on student learning, is it also important to take stock of parental views on learning environments.This study is focused on teachers' preferences for learning environments, their reported teaching behavior, and how these match with parents' preferences. Three parallel questionnaires were developed for teachers (n = 285), students (n = 951), and parents (n = 636) to measure preferences and behavior at different levels of education, for three types of learning environments: direct instruction; discovery learning; and authentic pedagogy. The results show that teachers often prefer direct instruction, and seldom promote discovery learning. While teachers sometimes realize authentic pedagogy, constructive learning tasks are seldom used. Teachers' reported practice and parents' preferences for their children appear to correspond reasonably.Results of multiple regression analyses show that the use of the three types of learning environments yield different predictors. For the use of discovery learning and authentic pedagogy, confidence in students' regulative skills is an important predictor. In predicting the use of direct instruction, the teacher's own conception of learning turns out to be an important predictor.     

Alternation of generations and experimental design: a guided-inquiry lab exploring the nature of the her1 developmental mutant of Ceratopteris richardii (C-Fern)

Inquiry-based labs have been shown to greatly increase student participation and learning within the biological sciences. One challenge is to develop effective lab exercises within the constraints of large introductory labs. We have designed a lab for first-year biology majors to address two primary goals: to provide effective learning of the unique aspects of the plant life cycle and to gain a practical knowledge of experimental design. An additional goal was to engage students regardless of their biology background. In our experience, plant biology, and the plant life cycle in particular, present a pedagogical challenge because of negative student attitudes and lack of experience with this topic. This lab uses the fern Ceratopteris richardii (C-Fern), a model system for teaching and research that is particularly useful for illustrating alternation of generations. This lab does not simply present the stages of the life cycle; it also uses knowledge of alternation of generations as a starting point for characterizing the her1 mutation that affects gametophyte sexual development. Students develop hypotheses, arrive at an appropriate experimental design, and carry out a guided inquiry on the mechanism underlying the her1 mutation. Quantitative assessment of student learning and attitudes demonstrate that this lab achieves the desired goals.     

Validation of a wireless accelerometer network for energy expenditure measurement

The purpose of this study was to validate a wireless network of accelerometers and compare it to a hip-mounted accelerometer for predicting energy expenditure in a semi-structured environment. Adults (n = 25) aged 18–30 engaged in 14 sedentary, ambulatory, exercise, and lifestyle activities over a 60-min protocol while wearing a portable metabolic analyser, hip-mounted accelerometer, and wireless network of three accelerometers worn on the right wrist, thigh, and ankle. Participants chose the order and duration of activities. Artificial neural networks were created separately for the wireless network and hip accelerometer for energy expenditure prediction. The wireless network had higher correlations (r = 0.79 vs. r = 0.72, P < 0.01) but similar root mean square error (2.16 vs. 2.09 METs, P > 0.05) to the hip accelerometer. Measured (from metabolic analyser) and predicted energy expenditure from the hip accelerometer were significantly different for the 3 of the 14 activities (lying down, sweeping, and cycle fast); conversely, measured and predicted energy expenditure from the wireless network were not significantly different for any activity. In conclusion, the wireless network yielded a small improvement over the hip accelerometer, providing evidence that the wireless network can produce accurate estimates of energy expenditure in adults participating in a range of activities.     

The influence of race/ethnicity on disadvantaged mothers’ child care arrangements

This study uses data from the Fragile Families and Child Wellbeing Study [Reichman, N., Teitler, J., Garfinkel, I., & McLanahan, S. (2001). The fragile families and child wellbeing study: Sample and design. Children and Youth Services Review, 23, 303–326] to describe primary child care arrangements of employed, predominantly low-income mothers of 1-year olds, and to quantify their child care calculus in the post-welfare reform era. The sorting of children across arrangement types differs by mother's race/ethnicity: Hispanic children are most likely to be cared for maternal kin, Black children in organized centers, and White children by their fathers. Multinomial regression reveals that the association between race/ethnicity and arrangement type is largely – but not entirely – accounted for by mothers’ socioeconomic, household, job, and cultural characteristics; interaction tests show that the associations between arrangement type and both poverty status and marital status are contingent on race/ethnicity. These findings indicate that disadvantage does not translate into child care arrangements similarly across racial/ethnic groups and child care policy must take into account structural and cultural differences associated with parents’ race/ethnicity.     

Student Collaboration in Group Work: Inclusion as Participation

Group work is an educational mode that promotes learning and socialisation among students. In this study, we focused on the inclusive processes when students work in small groups. The aim was to investigate and describe students’ inclusive and collaborative processes in group work and how the teacher supported or impeded these transactions. Social Interdependence Theory was utilised as the theoretical perspective overarching the study. The observational data employed were collected by video-recording group work. A part of Black-Hawkins framework of participation was used to define inclusion and for the analysis of inclusive and collaborative processes. The results suggest that students’ active participation in the discussions around the group work structures and analytical discussions, together with the teacher’s more defined feedback and avoidance of the traditional authoritative role, are examples of prerequisites for group work to be enacted in an inclusive manner.