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.     

Education of deaf students in Spain: legal and educational politics developments

This article examines the legal instruments and educational politics affecting deaf persons' educational rights in Spain. We present a historical view of deaf education in Spain before and after the Congress of Milan (1880) and then introduce educational legislation and practices in recent decades. At present, Spanish legislation is moving toward recognition of sign languages and the suitability of bilingual education for deaf students at all educational levels. This is a consequence of taking into account the low academic achievement of two generations of deaf students educated in a monolingual model. Bilingual projects are now run throughout Spain. We emphasize that efforts must be made in the legal sphere to regulate the way in which professionals who know sign language and Deaf culture-teachers, interpreters, deaf adult models-are incorporated in bilingual deaf schools.     

Anthropometric profiles of elite older triathletes in the Ironman Brazil compared with those of young Portuguese triathletes and older Brazilians

The objective of this study was to describe the anthropometric profiles of elite older triathletes participating in the 2009 Ironman Brazil and to compare their somatotype, anthropometric and body composition characteristics with those of elite young triathletes and older non-athletes. The sample consisted of 64 males, divided into three groups: (1) older triathletes (n = 17), (2) young triathletes (n = 24), and (3) older non-athletes (n = 23). Somatotype was analysed according to the Carter and Heath ( 1990 ) method. Body mass index, sum of four skinfolds, percentage body fat, body fat mass, and fat-free mass were also estimated. Older non-athletes had higher endomorphy, sum of four skinfolds, fat percentage, and body fat mass than the athletes. Older athletes who participated in the Ironman and elite young triathletes had higher fat-free mass than older non-athletes. Older triathletes and older non-athletes were considered mainly endomorphic mesomorphs and young triathletes mainly ectomorphic mesomorphs. The findings that characterize the anthropometric profile of athletes in this sports modality could be used as a reference.     

A mathematical model for decision-making in the classification of para-footballers with different severity of coordination impairments

Classification is a defining feature of Para-sport, and sports-specific classification systems determined through multidisciplinary scientific research are required, i.e., evidence-based and focused on the relationship between the impairment and the key performance determinants. Data envelopment analysis (DEA) was applied as a classification tool using a directional distance function (DDF) model. The aim of the study was to test the DEA as a possible classification tool in cerebral palsy football. We analyse the performance of 56 international para-footballers with hypertonia, ataxia or athetosis, who completed a 20-test battery with DEA models. Five of the tests are included in the model (change of direction: Illinois agility test; jumping: standing broad jump, four bounds for distance, and triple hop with the non-dominant leg; 10-m sprint/acceleration; and ball dribbling, both in a straight line and following a trajectory), showing that players with less impairment exhibit the highest efficiency. This outcome suggests that DEA models might be feasible for detecting and discriminating the performance and magnitude of impairment in cerebral palsy football, with an objective ranking of the athletes in relation to different physical performance tests. This study also provides reference scores for decision-making during classification and guidance for further research in team Paralympic sports.     

Application of functional derivatives to analysis of complex systems

The application of the functional derivatives to the mathematical modeling of complex systems is studied here. The connection of functional derivatives with total differentials in Banach spaces is shown. Local and global existence theorems for the linear equations in total differentials are proved. Consequently, a total integrability conditions are derived for the case of linear equations with the functional derivatives. Some illustrative examples are included.     

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.     

Validation of two accelerometers to determine mechanical loading of physical activities in children

The purpose of this study was to assess the validity of accelerometers using force plates (i.e., ground reaction force (GRF)) during the performance of different tasks of daily physical activity in children. Thirteen children (10.1 (range 5.4–15.7) years, 3 girls) wore two accelerometers (ActiGraph GT3X+ (ACT), GENEA (GEN)) at the hip that provide raw acceleration signals at 100 Hz. Participants completed different tasks (walking, jogging, running, landings from boxes of different height, rope skipping, dancing) on a force plate. GRF was collected for one step per trial (10 trials) for ambulatory movements and for all landings (10 trials), rope skips and dance procedures. Accelerometer outputs as peak loading (g) per activity were averaged. ANOVA, correlation analyses and Bland–Altman plots were computed to determine validity of accelerometers using GRF. There was a main effect of task with increasing acceleration values in tasks with increasing locomotion speed and landing height (P < 0.001). Data from ACT and GEN correlated with GRF (r = 0.90 and 0.89, respectively) and between each other (r = 0.98), but both accelerometers consistently overestimated GRF. The new generation of accelerometer models that allow raw signal detection are reasonably accurate to measure impact loading of bone in children, although they systematically overestimate GRF.     

The chameleon on a tartan rug: adaptations of three academic developers’ professional identities

This paper builds on discussions of academic developers’ identity experienced as a discomfiting, troubled, and often marginal space. Three experienced academic developers, located in research-intensive institutions in three different countries, using auto-ethnographic writing and a shared narrative inquiry, explore moments of congruence and conflict. While there are elements that sustain them in their job, the categorisation of their role can impact on their ability to do their job, undermining their credibility. This can prevent them from engaging in research that could enrich practice in their institutions and inform institutional strategy or change the culture in teaching and learning. Instead they are forced into discomfit: having to defend their right to be involved in the institutional discussions. The most worrying issue is the pervasive trend in the change of academic developers’ status (from tenure-track academic peers to professionals).     

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.