Effect of different swim caps on the assessment of body volume and percentage body fat by air displacement plethysmography

Isothermal air trapped in scalp hair generates an underestimation of body volume when it is measured by air displacement plethysmography. The aim of this study was to examine the effect of wearing different types of swim caps on the measurement of body volume and percentage body fat by air displacement plethysmography. It was hypothesized that wearing a silicone swim cap would more thoroughly compress scalp hair compared with a lycra swim cap, yielding higher estimates of body volume and percent body fat. Thirty female participants aged 25.7 ± 6.4 years were measured in random order when wearing no swim cap, a lycra swim cap or a silicone swim cap. For the no-cap versus lycra cap condition, the mean bias for body volume was -0.579 ± 0.380 litre (limits of agreement: -1.340 to 0.181 litre) and for percent fat -4.9 ± 3.1% fat (limits of agreement: -11.2 to 1.3% fat) (P < 0.05). For the silicone versus lycra condition, the mean bias for body volume was 0.137 ± 0.099 litre (limits of agreement: -0.062 to 0.335 litre) and for percent fat 1.2 ± 0.9% fat (limits of agreement: -0.5 to 2.9% fat) (P < 0.05). In conclusion, attention should be paid to optimal compression of isothermal air trapped in scalp hair when using air displacement plethysmography. The present results suggest that this compression may be more thorough when wearing a silicone swim cap.     

Economic hardship, parenting, and distress in adolescence

The relation between family economic hardship and adolescent distress among secondary school students in a small Midwestern community was investigated. According to prior results, family hardship has both direct and indirect effects on adolescent distress. The indirect effects come about through stress-induced changes in parental nurturance and parental discipline. The findings of this study showed that hardship effects varied according to type of distress. For females as well as males, economic hardship had both direct and indirect effects on a depression-loneliness distress factor. The indirect effects occurred through less parental nurturance and more inconsistent discipline. No direct effect of economic hardship was found for either males or females on a distress factor composed of delinquency and drug use items. For both females and males, however, an indirect effect of family economic hardship on the delinquency-drug use factor was found with inconsistent parental discipline as the mediating variable.     

Support from Spouse as Mediator and Moderator of the Disruptive Influence of Economic Strain on Parenting

A model is presented regarding associations between economic strain, support from spouse, and quality of parenting. The model was tested using a sample of 451 2-parent families, each of which included a seventh grader (age 12-13). Parent and adolescent reports, as well as observational ratings, were used as indicators of constructs. Analysis using structural equation modeling procedures indicated that level of spouse support was positively related to supportive parenting, whereas economic strain operated to undermine parental involvement. As posited, economic strain produced its effect through a direct relation with parenting and indirectly through its association with spouse support. These findings held for mothers and fathers, regardless of the gender of the child. Spouse support moderated the impact of economic strain on supportive parenting for mothers but not fathers. Possible explanations for this gender difference are presented.     

Pick a Number … Any Number?

A recent classroom revelation caused us to reconsider the adequacy of the instructions offered in our textbooks for one of our most elementary quantitative methods. Specifically, we found that many students were mystified concerning how to pick an initial objective function value when plotting an isoprofit line in order to graphically solve a linear programming problem. We observed that this seemingly insignificant issue was causing a surprising amount of wasted time, confusion, and even anxiety. Our experience indicated that students do not necessarily possess any consistent intuition for choosing an appropriate initial value. We confirmed this perception through informal experimentation. We reviewed several textbooks and found that most simply do not bother to address this issue. Therefore, we devised a simple, comprehensible method which we have taught our students to resolve or avoid this problem. Although we quickly found the method to be helpful for many students, we conducted an experiment to formally measure its effect.     

Measuring learners’ perceptions of a team-taught learning environment: development and validation of the Learners’ Team Teaching Perceptions Questionnaire (LTTPQ)

Learning Environments Research - Team teaching is a teaching model in which teachers work collaboratively in the preparation, teaching and evaluation of a course. Literature suggests that team...     

Teachers’ motives for learning in networks: costs,rewards and community interest

Background: This paper discusses teachers’ perspectives on learning networks and their motives for participating in these networks. Although it is widely held that teachers’ learning may be developed through learning networks, not all teachers participate in such networks.

Purpose: The theme of reciprocity, central to studies in the area of learning in networks, is often approached from a rational exchange perspective. This study attempts to extend this approach with reference to the concept of symbolic interactionism. The study was guided by the following research question: What is the relationship between teachers’ perceptions of learning networks and their motives for participation or non-participation in these networks?

Design and methods: In order to address this research question, semi-structured interviews among 25 teachers in secondary education in the Netherlands were carried out. The semi-structured interviews consisted of three parts: background information, perspectives on learning networks and personal experiences with those networks. Data were analysed qualitatively and analyses consisted of within-case analysis, and cross-case analysis of interview fragments. Three themes were considered: (1) perspectives on learning networks, (2) motives for participation perceived as rational exchange, (3) motives for participation perceived as related to social order.

Findings: The findings are presented around these three themes. Each theme is discussed in relation to relevant aspects from the literature. Findings indicated that teachers perceived learning networks to be organised both within-school and outside school, and mostly focused around specific content knowledge. Reasons for participation or non-participation were related to rational costs and rewards (such as time, technology, self-efficacy); in symbolic motives (such as joy, sharing and mutual understanding), and also in a sense of meaning that resulted from networking activities.

Conclusions: We conclude that, in addition to social exchange motives, the data suggest that symbolic aspects of communication and interaction play an important role in considerations for participation in learning networks. This may be described in terms of four ‘types’ of networking teachers: the Community focused networking teacher, the Locally focused networking teacher, the Not-yet-networking teacher, and the Non-networking teacher. It is hoped that these exploratory findings could be helpful in supporting the development of learning networks for all teachers.     

Initial and Further Education: Substitutes or Complements? Differences in Continuing Education and Training over the Life-Course of European Workers

This investigation examines the place of initial and further education in continuing education and training over the life-course of workers across Europe. The evidence presented demonstrates that in countries with a strong orientation towards vocational education, participation in continuing education and training among employees is higher than in countries that mainly provide general education. Moreover, it can be seen that the effect of the vocational orientation of the education system increases over the life-course of workers. The conclusion of this investigation is that further education complements rather than substitutes for initial education. This implies that national education and training policies meant to encourage lifelong learning should not only attempt to expand or redirect training received by already experienced workers, but also try to facilitate participation in initial vocational training.     

Comparing the gender gap in educational attainment: the impact of emancipatory contexts in 33 cohorts across 33 countries

Nowadays, women outperform men in educational attainment in many countries. Still, large variation between countries remains. Emancipatory contexts in which individuals are raised might explain these differences in male–female educational attainment, both over time and across countries. This study examines individual and contextual factors that affect educational attainment of men and women for cohorts born between 1950 and 1982 across 33 countries. Possible explanations for differentiation over time and across countries relate to women’s labour market participation and an emancipatory normative climate, indicated by degree of religiosity. We employ multilevel models on data (N = 138,498) from 6 waves of the European Social Survey and the US General Social Survey (2002–2012) to test our hypotheses. Results show that a higher level of female labour market participation in early adolescence improves women’s performance in education, whereas high levels of religiosity during that phase negatively affect women’s educational attainment.