Modelling Molecular Mechanisms: A Framework of Scientific Reasoning to Construct Molecular-Level Explanations for Cellular Behaviour

Although molecular-level details are part of the upper-secondary biology curriculum in most countries, many studies report that students fail to connect molecular knowledge to phenomena at the level of cells, organs and organisms. Recent studies suggest that students lack a framework to reason about complex systems to make this connection. In this paper, we present a framework that could help students to reason back and forth between cells and molecules. It represents both the general type of explanation in molecular biology and the research strategies scientists use to find these explanations. We base this framework on recent work in the philosophy of science that characterizes explanations in molecular biology as mechanistic explanations. Mechanistic explanations describe a phenomenon in terms of the entities involved, the activities displayed and the way these entities and activities are organized. We conclude that to describe cellular phenomena scientists use entities and activities at multiple levels between cells and molecules. In molecular biological research, scientists use heuristics based on these intermediate levels to construct mechanistic explanations. They subdivide a cellular activity into hypothetical lower-level activities (top-down approaches) and they predict and test the organization of macromolecules into functional modules that play a role in higher-level activities (bottom-up approaches). We suggest including molecular mechanistic reasoning in biology education and we identify criteria for designing such education. Education using molecular mechanistic reasoning can build on common intuitive reasoning about mechanisms. The heuristics that scientists use can help students to apply this intuitive notion to the levels in between molecules and cells.     

Socialisation into organised sports of young adolescents with a lower socio-economic status

Studies investigating sport socialisation often focussed on the barriers for youngsters from lower socio-economic status (SES) families to participate in sport. In the present study, the socialisation into sports of young adolescents from lower SES families that do participate in organised sports was investigated. A total of 9 girls and 12 boys from lower SES families (18 Dutch; three foreign ethnic background) from one city in the Netherlands who participated in organised sport were interviewed. Although multiple agents may be of influence on the socialisation process, this study was limited to the family, school and peers as potential socialising contexts. Drawing on the theoretical work of Bourdieu and Bernstein, parents were found to be the main influencers of the sports habitus of these young adolescents. The school context appeared to have no influence on their sport socialisation. Peers were found to have an influence on the choice for a specific type of sport. This interplay between socialising contexts for young adolescents from lower SES families is similar to the sport socialisation of youngsters from higher SES families. Therefore, it is suggested that if sport socialisation takes place, then the role of SES is less pronounced than often assumed. Moreover, there seem to be differences in the relative importance of the socialising contexts with younger children with a lower SES. Therefore, it is hypothesised that the relative importance of socialising agents changes over time. Although the findings may be limited to the specific sample of this study, they provide hypotheses that challenge the often-presumed importance of SES if sport socialisation takes place.     

A physically active lifestyle is related to a lower level of skin autofluorescence in a large population with chronic-disease (LifeLines cohort)

Background:Physical activity(PA)has substantial health benefits and is important in combatting chronic diseases,which have been associated with elevated levels of advanced glycation endproducts(AGEs).AGEs play a role in the aging process,and an association between PA and AGEs has been reported.We aimed to investigate the relationship between PA and AGE accumulation in a general population and in a population with chronic diseases.Methods:This large cross-sectional population study used data from adult participants in the LifeLines project,with participant information drawn from the LifeLines database as well data from patients with diabetes mellitus or renal and/or cardiovascular diseases.Tissue AGE accumulation was assessed non-invasively by skin-autofluorescence(SAF)using an AGE reader(DiagnOptics Technologies BV,Groningen,the Netherlands).PA was assessed using the short questionnaire to assess health-enhancing physical activity(SQUASH).Multivariate linear regression analyses were adjusted for age,body mass index,sex,and smoking status.Results:Data from 63,452 participants(general population n=59,177,chronic disease n=4275)were analyzed.The general population was significantly younger(43.58±11.77 years,mean±SD)and had significantly lower SAF(1.90±0.42 arbitrary units(AU))compared to the population with chronic disease(age:55.51±12.07 years;SAF:2.27±0.51 AU).In the group with chronic disease,more hours of moderate to vigorous physical activities per week were associated with lower SAF(β=-0.002,95%confidence interval(95%CI):-0.002 to-0.001).For the general population,there was no association between hours of moderate to vigorous activity and SAF(β=3.2×10^-5,95%CI:0.000-0.001,p=0.742).However,there was an association in the general population between total hours of PA per week and SAF(β=4.2×10^-4,95%CI:0.000-0.001,p<0.001),but this association was not found in the chronic disease population(β=-3.2×10^-4,95%CI:-0.001 to 0.000,p=0.347).Conclusion:Our study demonstrates that an inverse relationship exists between PA and AGE accumulation in the population with chronic disease.More hours of moderate to vigorous activity is associated a significantly decreased SAF.More PA is associated a lower SAF,even after for the established predictors(age,body mass index,smoking status,and sex).Our findings could help to promote health and prolong longevity.     

Intellectual Disability and Developmental Risk: Promoting Intervention to Improve Child and Family Well‐Being

Initial intervention processes for children with intellectual disabilities (IDs) largely focused on direct efforts to impact core cognitive and academic deficits associated with the diagnosis. Recent research on risk processes in families of children with ID, however, has influenced new developmental system approaches to early intervention. Recent risk and resilience processes are reviewed that connect stress, family process, and the high rates of behavioral problems in children with ID that have substantial influence on child and family outcomes. These models are linked to emerging evidence‐based intervention processes that focus on strategic parent skill training and mindfulness interventions that reduce parental stress and create indirect benefits for children's behavioral competencies. A family‐focused developmental systems approach (M. J. Guralnick, 2011) is emphasized.     

University Practicum Supervisors: marching to a different drummer?

The roles and responsibilities of university supervisors in the practicum have changed during the last ten years. Once, the routine tasks of observation and feedback of student teaching performance were the main responsibilities associated with visits to the school. Lecturers in this role also determined, with the school personnel, the assessment rating of the student teacher. Presently, there is considerable variation in the part played by university supervisors of the practicum. Against this background, this paper examines the actual and ideal characteristics of university supervisors from their own viewpoint and from the perspective of teacher supervisors, principals and student teachers. The reasons for the actual‐ideal discrepancies are discussed, and suggestions are made in relation to addressing the matter.     

选用案例 加强教学

学校教育教学的主要途径是课堂教学，提高课堂教学效率的较好方法是有效选用教学案例。文章从教学案例的材料来源上，强调教学案例选用客观性；联系教学内容，讨论教学案例选用的适用性；依据学生的实际，阐述教学案例选用的针对性；依据教学过程，介绍教学案例有效的选用方法，提高教学案例在课堂教学中的有效性，从而达到提高课堂教学的效率。     

Environmental paper buying — best practice

In this article the environmental and commercial issues, which are an integral part of the need for, and practice of, recycling paper, are explored and explained. Although of particular interest to publishers, paper buyers and printers this is a subject that no one can afford to ignore.