Split genes

Contrary to what Jacques Monod affirmed in the 1960s, it is now known that what is true of the bacterium is not true of the elephant. In particular, it was discovered in 1977 that the genes of the higher organisms are split into segments, instead of being continuous as is the case with, for example, Escherichia coli. What is the significance of this split structure and how do organisms manage to gather together the useful parts of their genes and to eliminate those which are surplus? This article reviews what is already certain in this field and comments on the most recent prospects opened up by the discovery of genes ‘in pieces’.     

Combining concept maps and interviews to produce representations of personal professional theories in higher vocational education: effects of order and vocational domain

This article presents the use of personal professional theories (PPTs) in Dutch higher vocational education. PPTs are internalised bodies of formal and practical knowledge and convictions that professionals use to direct their behaviour. With the aid of high-quality representations of students’ PPTs teachers can access, monitor, and support the professional development of students. Two qualitatively equivalent techniques for representing PPTs are (computer-supported) concept mapping and interviewing. The article reports on a study of the effects of combining these techniques to determine whether (1) this results in higher quality representations and (2), if so, whether technique order will make a difference. The study was conducted in two very different vocational domains: accountancy with 29 participants and teacher education with 20 participants. The results of a counterbalanced quasi-experiment with two factors (i.e. domain and order) show in both domains that combining the techniques improves quality but that the order in which the techniques are applied does not matter. This order independence has practical importance as the combination of first conducting a computer-supported analysis of a student generated concept map and subsequently discussing the results with the student, fosters learning and is well suited to educational practice.     

Interdisciplinary Research: A Promising Approach to Investigate Elite Performance in Sports

While the call for interdisciplinary studies has been loud and clear over the last decade or so, the number of interdisciplinary publications in sport sciences is rather limited. One of the reasons for this scarcity is the complexity of the research process itself. Still, the combination and integration of information from different scientific disciplines seems to be important to better explain how elite performance comes about. In this article, we focus on this issue and discuss the advantages of interdisciplinary research for understanding how elite athletes are able to achieve such high-proficiency levels. The first section provides an overview of the studies that investigated elite performance in sports. In the second section, we focus on the issue of interdisciplinarity and illustrate how the ecological–dynamical approach and the concept of dimensional reduction can be used to explain how elite performers cope with the complex nature of sport skills. In the last section, we present a research outline and some practical considerations that can be helpful for researchers who aim to study sport skills from an interdisciplinary perspective.     

Apprentissage dans un environnement informatique: possibilité nature transfert des acquis

Resumé L'articulation des deux registres algébrique et graphique de représentation des fonctions est l'une des grandes difficultés rencontrés dans l'appropriation du concept de fonction. Dans cet article, nous étudions les possibilités d'apprentissage offertes par un logiciel Fonctuse susceptible de favoriser cette articulation. Une première expérimentation, courte, à laquelle ont participé 56 élèves de lycée, a montré l'efficacité du logiciel. Une seconde expérimentation, présentée dans cet article, a été ensuite réalisée avec un seul binôme mais sur une plus longue période, pour mieux comprendre les processus cognitifs en jeu dans cet environnement, les construtions de connaissance posssibles et la transférabilité des acquis à un environnement traditionnel. Nous étudions en particulier l'influence sur ces processus et acquis des connaissances algébriques antérieures des élèves.

---

Linking the algebraic and graphical representations of functions is one of the great difficulties encountered in learning the function concept. In this article, we examine the possibilites for learning offered by a piece of software Fonctuse, likely to encourage this linking. A first short experiment, conducted with 56 upper secondary students, showed the effectiveness of the software. A second experiment, reported in this article, was then carried out with a single pair of students, but over a longer period, in order to better understand the cognitive processes at play in this environment the construction of knowledge which are possible and their transferability to a more traditional environment. We study, in particular the influence of prior algebraic knowledge on these process and constructions.

     

On the Relation Between Teachers’ (In)formal Learning and Innovative Working Behavior: the Mediating Role of Employability

Teachers’ innovative work behavior and professional development is receiving more attention lately. More precisely, it is argued that teachers’ formal and informal learning is crucial to anticipate and deal with continuous changes and innovations in technology and didactics, for example. Therefore, this study researches the teachers’ innovative work behavior by studying relations between (in)formal learning activities, employability (i.e. five competences: occupational expertise, anticipation and optimization, personal flexibility, corporate sense and balance) and innovative working behavior (IWB, i.e. ideas generation, promotion and realization). Furthermore, the mediating role of employability between learning and innovative working behavior is studied, too. Based on path analysis conducted on questionnaire data from 301 primary and secondary school teachers from the French-speaking community of Belgium, findings conclude that employability competences are related to both formal and informal learning, but the relationship between informal learning and employability is stronger. Next, making a distinction between the frequency and use of social informal learning is relevant given the differentiated role the different components play. Feedback use in particular seems to play an important role in teachers’ employability and IWB. Finally, it can be concluded that employability partially mediates the relation between the undertaking of (in)formal learning activities and dimensions of innovative working behavior. Results imply that schools should pay more attention to supporting teachers’ informal learning since it’s crucial for improving their ability to innovate and to be able to deal with changes in the dynamic world of education.     

Droplet microfluidics for kinetic studies of viral fusion

Viral infections remain a major threat to public health. The speed with which viruses are evolving drug-resistant mutations necessitates the further development of antiviral therapies with a large emphasis on drug discovery. To facilitate these efforts, there is a need for robust, high-throughput assays that allow the screening of large libraries of compounds, while enabling access to detailed kinetic data on their antiviral activity. We report here the development of a droplet-based microfluidic platform to probe viral fusion, an early critical step in infection by membrane-enveloped viruses such as HIV, Hepatitis C, and influenza. Using influenza A, we demonstrate the measurement of the kinetics of fusion of virions with target liposomes with sub-second temporal resolution. In analogy with acidification of the endosome that triggers fusion in a cellular context, we acidify the content of aqueous droplets containing virions and liposomes in situ by introducing acid from the dispersed phase and visualize the kinetics of fusion by using fluorescent probes.     

A comparison of methods to determine maximal accumulated oxygen deficit in running

The aim of this study was to compare maximal accumulated oxygen deficit (hereafter O2 deficit) estimated from the methods of Whipp et al. (1986), Medbo et al. (1988), and Hill et al. (1998) to determine whether they agree sufficiently to be used interchangeably. Nineteen moderately to highly trained endurance runners first performed an incremental test to exhaustion for the determination of maximal oxygen uptake ([Vdot]O(2max)) and peak treadmill speed, followed by six randomly ordered constant-speed tests at 95, 100, 105, 110, 110, and 120% of peak treadmill speed. All tests were separated by at least 72 h and were performed within 4 weeks. The method of Whipp produced an O(2) deficit estimate that was lower than that derived from the method of Hill or Medbo (bias +/- 95% limits of agreement: -29.6 +/- 36.6 and -26.1 +/- 32.8 ml . kg(-1), respectively; P < 0.001). The O2 deficit did not differ between the methods of Hill and Medbo (bias +/- 95% limits of agreement: 3.5 +/- 41.6 ml . kg(-1); n.s.). However, poor correlations (0.21 < r < 0.33; n.s.) together with wide limits of agreement between O2 deficit estimates (70 - 80% of the mean response) clearly question using these methods interchangeably.     

Radiation background due to radioactivity in palaces and museums: influence on TL/OSL dating

The environmental radiation level is unknown for objects that have been in collections for decades or centuries. We have performed dose rate measurements in museums representative of ancient castles and palaces. Annual dose rates between 0.3 and 1.3 mGy/year have been measured. There is a correlation between annual rates and the materials close to the dosimeters. The dating of objects by luminescence (TL and OSL) requires accurate knowledge of the dose rate in the minerals under investigation. An estimation of the errors on ages can be deduced from our measurements for typical situations of works of art and museum objects.     

Facilitating social learning in teacher education: a case study

It is increasingly recognised that social learning by teachers can stimulate professional development. In this study, we search for the social behaviour patterns which can act as a catalyst for professional development, with an explicit focus on student teachers’ learning. Based on the ‘Dimensions of Social Learning (DSL) Framework’, including 4 dimensions and 11 indicators of social learning, the present study explores the social configuration of one network of primary teachers (n?=?12), student teachers (n?=?12) and teacher educators (n?=?2). Two research questions guide this exploration: (1) What patterns of social behaviour in teacher networks are likely to lead to professional learning? (2) What network facilitation guidelines can be discerned to assist teachers and teacher educators wishing to optimise student teachers’ professional development? Data collection consisted of video recordings, reflective notes and semi-structured interviews with network members. The findings paint a picture of how social learning in teacher networks is related to the group’s social configuration. Observation criteria and student facilitation guidelines are suggested to support professional development within teacher networks. For each dimension in the DSL Framework, one point of attention is discerned to optimise students’ learning in teacher networks.