Reading and Spelling Development Across Languages Varying in Orthographic Consistency: Do Their Paths Cross?

We examined the cross-lagged relations between reading and spelling in five alphabetic orthographies varying in consistency (English, French, Dutch, German, and Greek). Nine hundred and forty-one children were followed from Grade 1 to Grade 2 and were tested on word and pseudoword reading fluency and on spelling to dictation. Results indicated that the relations across languages were unidirectional: Earlier reading predicted subsequent spelling. However, we also found significant differences between languages in the strength of the effects of earlier reading on subsequent spelling. These findings suggest that, once children master decoding, the observed differences between languages are not related to the direction of the effects but to the strength of the effects from reading to spelling. Theoretical and practical implications are discussed.     

Enhancement of biosensing performance in a droplet-based bioreactor by in situ microstreaming

A droplet-based micro-total-analysis system involving biosensor performance enhancement by integrated surface-acoustic-wave (SAW) microstreaming is shown. The bioreactor consists of an encapsulated droplet with a biosensor on its periphery, with in situ streaming induced by SAW. This paper highlights the characterization by particle image tracking of the speed distribution inside the droplet. The analyte-biosensor interaction is then evaluated by finite element simulation with different streaming conditions. Calculation of the biosensing enhancement shows an optimum in the biosensor response. These results confirm that the evaluation of the Damköhler and Peclet numbers is of primary importance when designing biosensors enhanced by streaming.It has been pointed out that biosensing performances can be limited by the diffusion of the analytes near the sensing surface.¹ In the case of low Peclet number hydrodynamic flows, typical of microfluidic systems, molecule displacements are mainly governed by diffusive effects that affect time scales and sensitivity. To overcome this problem, the enhancement of biosensor performance by electrothermal stirring within microchannels was first reported by Meinhart et al.² Other authors^{3, 4} numerically studied the analyte transport as a function of the position of a nanowire-based sensor inside a microchannel, stressing on the fact that the challenge for nanobiosensors is not the sensor itself but the fluidic system that delivers the sample. Addressing this problem, Squires et al.⁵ developed a simple model applicable to biosensors embedded in microchannels. However, the presented model is limited to the case of a steady flow. The use of surface-acoustic waves (SAWs) for stirring in biomicrofluidic and chemical systems is becoming a popular investigation field,^{6, 7, 8, 9} especially to overcome problems linked to steady flows by enhancing the liquid∕surface interaction.^{1, 10, 11} The main challenges that need to be addressed when using SAW-induced stirring are the complexity of the flow and its poor reproducibility. However, some technical solutions were proposed to yield a simplified microstreaming. Yeo et al. presented a centrifugation system based on SAW that produces the rotation of the liquid in a droplet in a reproducible way by playing on the configuration of the transducers and reflectors,¹² and presented a comprehensive experimental study of the three-dimensional (3D) flow that causes particle concentration in SAW-stirred droplets,¹³ revealing the presence of an azimuthal secondary flow in addition to the main vortexlike circular flow present in acoustically stirred droplets. The efficiency of SAW stirring in microdroplets to favorably cope with mass transport issues was finally shown by Galopin et al.,¹⁴ but the effect of the stirring on the analyte∕biosensor interaction was not studied. It is expected to overcome mass transport limitations by bringing fresh analytes from the bulk solution to the sensing surface.The studied system, described in Fig. ​Fig.1,1, consists of a microliter droplet microchamber squeezed between a hydrophobic piezoelectric substrate and a hydrophobic glass cover. Rayleigh SAWs are generated using interdigitated transducers (interdigital spacing of 50 μm) laid on an X-cut LiNbO₃ substrate.^{1, 15, 16} The hydrophobicity of the substrate and the cover are obtained by grafting octadecyltrichlorosilane (OTS) self-assembled monolayers (contact angle of 108° and hysteresis of 9°). To do so, the surface is first hydroxylized using oxygen plasma (150 W, 100 mT, and 30 sccm³ O₂) during 1 min and then immersed for 3 h into a 1 mM OTS solution with n-hexane as a solvent.Open in a separate windowFigure 1(a) General view of the considered system. (b) Mean value of the measured speeds within the droplet as a function of the inlet power before amplification.When Rayleigh waves are radiated toward one-half of the microchamber, a vortex is created in the liquid around an axis orthogonal to the substrate due to the momentum transfer between the solid and the liquid. This wave is generated under the Rayleigh angle into the liquid.Speed cartographies of the flow induced in the droplet are realized using the particle image tracking technique for different SAW generation powers. To do so, instantaneous images of the flow are taken with a high-speed video camera at 200 frames∕s and an aperture time of 500 μs on a 0.25 μl droplet containing 1 μm diameter fluorescent particles. Figure ​Figure11 shows the mean speed measured in the droplet as a function of the inlet power. The great dependence of the induced mean speed with the SAW power enables a large range of flow speeds in the stirred droplet. Moreover, the flow was visualized with a low depth of field objective. It was found to be circular and two dimensional (2D) in a large thickness range of the droplet.The binding of analytes to immobilized ligands on a biosensor is a two step process, including the mass transport of the analyte to the surface, followed by a complexation step,Abulk↔kmAsurface+B↔ka,kdAB(1)with k_m as the constant rate for mass transport from and to the sensor, and k_a and k_d as the constant rates of association and dissociation of the complex.At the biosensor surface, the reaction kinetics consumes analytes but their transport is limited by diffusive effects. In this case, the Damköhler number brings valuable information by comparing these two effects. Calling the characteristic time of reaction and diffusion, respectively, τ_C and τ_M, the mixing time in diffusion regime can be approximated by τ_M≈h²∕D with D as the diffusion coefficient and h a characteristic length of the microchannel. Calling R_T the ligand concentration on the surface in mole∕m², the Damköhler number (D_a) can be written asDa=τMτC=kaRThD.(2)Depending on the type of reaction, the calculation of D_a helps determine if a specific biointeraction will benefit from a mass SAW-based microstreaming. If the Damköhler number is low, the reaction is slow compared to mass transport and the reaction will not significantly benefit from microstirring. For example, the hybridization of 19 base single stranded DNA in a microfluidic system with a characteristic length of 500 μm is characterized by a Damköhler number of 0.07 and is therefore not significantly influenced by mass transport. On the contrary, the binding of biotin to immobilized streptavidin is characterized by a D_a number of approximately 10⁴. In this case, the stirring solution will significantly improve the reaction rate.COMSOL numerical simulations were carried out to study the efficiency of the SAW stirring in the case of a droplet-based microbioreactor with a diameter of 1 mm. Assuming a 2D flow, the simulated model takes into account the convective and diffusive effects in the analyte-carrying fluid and the binding kinetics on the biosensor surface. This approach was thoroughly developed by Meinhart et al.²On the biosensor surface, the following equations are solved:∂B∂t=kacs(RT−B)−kdB,(3)∂B∂t=D|∂c∂y|y=0(4)with c as the local concentration of analytes in the droplet and B as the surface concentration of bound analytes on the biosensor surface. Simulation results show that a depleted zone is formed near the biosensor in the case of an interaction without stirring. This zone is characterized by a low concentration of analytes and results from the trapping of analytes on the biosensor surface, thus creating a concentration gradient on the vicinity of the biosensor. When stirring is applied, the geometry of the depleted zone is modified, as it is pushed in the direction of the flow. The geometry of the depleted zone then depends on many parameters, among which the diffusion coefficient D, the speed distribution of the flow (not only near the biosensor but also in the whole microfluidic system), and the reaction kinetics on the biosensor. In our case, which is assimilated to a simple circular flow, the depleted zone reaches a permanent state consisting of an analyte-poor layer situated in the exterior perimeter of the stirred droplet. The diffusion of analytes is then limited again by diffusion from the inner part of the droplet toward its exterior perimeter (see Fig. ​Fig.22).Open in a separate windowFigure 2(a) Mean concentration of bound analytes vs time for different mean flow speeds. (b) The obtained concentration profiles with and without circular stirring, t=10 000 s.The initial analyte and receptor concentrations are, respectively, 0.1 nM in the solution and 3.3×10⁻³ nM m on the biosensor surface, the diffusion coefficient is D=10⁻¹¹ m² s⁻¹, and the reaction constants are k_a=10⁶ M⁻¹ s⁻¹ and k_d=10⁻³ s⁻¹. Simulations show that the mean concentration of bound analytes highly increases with the flow speed, improving the efficiency of the biosensing device. To evaluate the benefits of in situ microstreaming with SAW, the same simulations were conducted for D_a numbers ranging from 10⁴ to 10⁸ M⁻¹∕s, by ranging the diffusion coefficient from 4×10⁻¹² to 4×10⁻⁹ m²∕s, and the association coefficient k_a from 10⁴ to 10⁸ M⁻¹∕s. The enhancement factor of analyte capture, defined as the ratio of the binding rate with streaming B and the binding rate without streaming B0, is plotted in Fig. ​Fig.33 for different values of D_a. Calculations are done in the case of a mean flow speed of 0.5 mm∕s.Open in a separate windowFigure 3(a) Enhancement factor (defined as the ratio between binding rate with streaming B and binding rate without streaming B0) for different Damkhöler numbers and (b) normalized enhancement factor for different Peclet numbers.One can notice the saturation of the enhancement factor curve for large value of D_a to the value of 3.5 for high D_a. This can be explained by the fact that for large k_a∕D_a ratios, the analytes, which normally require penetration in the depleted zone by diffusion, do not have time to interact with the biosensor when they pass in the vicinity of its surface. The efficiency of the streaming is then reduced for large values of D_a. In the case of our specific flow configuration, the enhancement factor reaches 3.2 for the interaction of streptavidin on immobilized biotin (D_a=10³).The reported simulation results can be compared to an experimental value obtained using the droplet-based surface plasmon resonance sensor streamed in situ using SAW reported by Yeo et al.¹² By monitoring the streptavidin∕biotin binding interaction on an activated gold slide, they showed that SAW stirring brings an improvement factor of more than 2. This difference can be accounted to the high complexity of the induced 3D flow, which was modeled in a simple manner in our calculations.Other factors must be taken into account when optimizing the improvement factor, such as the flow velocity and the characteristic length of the mixing. To do so, the Peclet number allows the comparison of the convective and diffusive effects.¹⁷ For δC a typical variation in concentration on the distance h, the Peclet number is given byPe=UhD.(5)A significantly high Peclet number causes a decrease in biosensing efficiency as the analytes do not have enough time to interact with the biosensing surface by diffusion through the analyte-poor layer. On the contrary, the case of a low Peclet number corresponds to the diffusion-limited problem. Therefore, for each Damköhler number, there is a Peclet number optimizing this factor. To illustrate this fact, Fig. ​Fig.3b3b shows the calculation of the enhancement factor as a function of the Peclet number for a given D_a.In this paper, we showed that surface loading of typical analytes on a droplet-based biosensor can be highly increased by SAW microstirring. The system permits the enhancement of the biosensing performances by the continuous renewal of the analyte-carrying fluid near the sensing surface. Thanks to mean flow speeds measured up to 1800 μm∕s, the SAW microstreaming can be beneficial to the biosensing of a large range of analyte∕ligand interactions. In addition to the biosensing performance improvement, such a method can be easily integrated in micro-micro-total-analysis systems, which makes it a convenient tool for liquid handling in future biochips.     

A review of the penetration of Francophone research on intervention in physical education and sport in Anglophone journals since 2010

ABSTRACT

Introduction: Since the 1990s, the notion of intervention has expanded with growing interest in the analysis of practices in Francophone country. French-speaking research community considers intervention sciences as a specific field of research in sport and PE. The aim of this literature review was to characterize the penetration of Francophone research in the English-language literature in physical education and sport concerned with intervention since 2010 in the category ‘Education & Educational Research’ of the Journal Citation Reports (2017). This research was in line with the analysis of the papers presented during six Francophone congresses from 2000 to 2010 of the Association for Research on Intervention in Sport (Musard and Poggi 2015 Musard, Mathilde, and Marie-Paule Poggi. 2015. “Intervention in Physical Education and Sport: Trends and Developments in a Decade of Francophone Research.” Physical Education and Sport Pedagogy 20 (3): 250–267. doi:10.1080/17408989.2013.817008.[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]).

Methods: The selection of articles was carried out in three stages: selection of journals, selection of articles manually, the second level of selection. The selection of journals is do in this category "Education & Educational Research" (JCR, 2017) focusing primarily on sport and physical education. Six journals met these criteria: Physical Education and Sport Pedagogy, European Physical Education Review, Journal of Teaching in Physical Education, Sport Education and society, Quest, Journal of Hospitality Leisure Sport & Tourism Education. Then, the selection of articles was manually analyzing all the publications of each journal since 2010 (almost 2000 articles) according to inclusion criteria "sport or physical education", "francophone authors", and "intervention". Each 46 articles selected was classified according to its theoretical framework. The last stage of selection corresponded to an analyze and an extension of the literature review by a French-speaking specialist in each theoretical framework.

Results: The results show that French-language research on/in/for intervention is in close connection with the international tradition. Some approaches such as didactique, a technological approach, and course of action, have a Francophone specificity based on various international theoretical anchors; others such as motor learning, social psychology, ecological approach come from non-French-speaking international theoretical frameworks.

Discussion and conclusion: These findings raise the question of the Francophone specificity of intervention sciences. Beyond particular French-speaking theoretical frameworks, concepts and concerns join Anglophone traditions. As in the international fields of ‘sport pedagogy’ or ‘praxis’, the Francophone intervention sciences are composed of a diversity of theoretical approaches and are focused towards an epistemology of action. These two communities can enrich each other and deserve more interaction and exchange.     

Key Competences in Europe: interpretation,policy formulation and implementation

The evolution in Europe towards more competence-based curricula in the last ten years or so is the result of several exogenous factors and a determined European policy. The Reference Framework of Key Competences for Lifelong Learning, a Recommendation approved by the European Parliament and the Council in 2006, and the work carried out within the Open Method of Coordination as well as by European research bodies have had a significant impact on Member States' curriculum reforms. This article shows that some terminology issues, both conceptual and practical, may explain, together with other causes, the diverse formulations of key competences and the way in which they are being integrated into the compulsory education curricula by the Member States or at intra-national levels. The focus of the article is on cross-curricular competences because these are the key competences which require the most significant innovations in teaching and learning practices, on assessment tools and procedures, and school organisation. The analysis illustrates the main differences and convergences in policy formulation and implementation strategies among the EU Member States. It also identifies key obstacles that must be overcome for an effective implementation before suggesting some policy recommendations.     

On the interest of enunciative postures (co-enunciation,under-enunciation,over-enunciation) for the interpretation of texts (in the classroom) / Sobre el interés de las posturas enunciativas de coenunciación,infraenunciación y supraenunciación para la interpretación de textos (en el aula)

Abstract

This article makes a provisional assessment of the question of enunciative postures. It begins by distinguishing co-enunciation and co-locution and defining postures with respect to the role of the enunciators in the co-construction of points of view (POV): co-enunciation corresponds to the speaker’s co-construction of a common POV, which commits them as enunciators. Over-enunciation is defined as an unequal co-construction of a dominating POV and under-enunciation consists of the unequal co-construction of a dominated POV. The second part illustrates the role of these different postures in the analysis and interpretation of texts with the aim of optimising their pedagogical exploitation by defining the enunciative stakes and the interactional positioning underlying in the construction of POV.     

Importance of Ability Grouping in French “Collèges” and its Impact upon Pupils’ Academic Achievement

This article tries to assess the prevalence and learning consequences of ability grouping in French lower secondary schools (collèges). The article shows that ability grouping is in fact relatively widespread in France and has a strong local connotation. In terms of pupil learning, the article stresses that the better the class they attend, the better students tend to perform. However, a heterogeneous context proves to be more favourable (for low achievers, a homogeneous class is the worst case). The results also stress the existence of a potential conflict of interest between the policy-maker and the actors of the system. Résumé L’article vise à évaluer l’importance de l’organisation des études en groupes de niveau dans le premoier cycle secondaire en France ainsi que ses conséquences en termes d’acquisitions des élèves. L’article montre en premier lieu que cette pratique est en fait relativement fréquente dans les établissements français tout en ayant une dimension locale assez accentuée. En termes d’acquisitions, l’article souligne que les progressions des élèves ont tendance à être d’autant meilleures que le niveau moyen des élèves de la classe est élève; cependant, un contexte hétérogène s’avère aussi le plus favorable (un contexte homogène étant la pire des choses pour les élèves faibles). Les résultats soulignent aussi l’existence d’un conflit potentiel d’intérêt entre le décideur du système qui vise des onjectifs généraux et les différents acteurs (enseignants, parents d’élèves) qui visent leurs intérêts particuliers.     

A Round-Up of French Language Media Publications

François Archambault & Jean François Lemoine, Quatre milliards de journaux: La presse de province (Paris: A. Moreau, 1977—55 FF, 484 pp.)

Alain Besson, La Presse locale en liberté surveillée (Paris: Editions Ouvrières, 1978—38 FF, 256 pp.)

Jean Cluzel, Télé-Violence (Paris: Plon, 1978—35 FF, 251 pp.)

Jean Egen, Le Canard Enchainé (Paris: Seghers, 1978—19.50 FF, 187 pp.)

Francis Hamon, Liberté et responsabilité de la presse en Grande-Bretagne: le Press Council; and Claude-Jean Bertrand, Les Conseils de presse dans la monde (Paris: Notes et etudes documentaires, La Documentation francaise, December 26, 1977—10.50 FF, 79 pp.)

Denis Perier-Daville, La Liberté de la presse nest pas à vendre (Paris: Le Seuil, 1978—42 FF, 254 pp.)

Jean Bruno Renard, Clefs pour la bande dessineé (Paris: Seghers, 1978— 25 FF, 256 pp.)

Pierre Schaeffer, Les Antennes de Jéricho (Paris: Stock, 1978—49 FF, 333 pp.)     

Higher education and employment markets in France

The theory of human capital has been used to account for the link between educational investment and individual earnings. The authors argue that any investigation of the relationship between these two elements must take into account the choice model used by the individual student as he enters higher education. His academic and social background influence his choice as do his estimate of the returns likely to come from investing in the study of particular disciplines and the extent to which he is prepared to risk failure, especially in highly competitive programmes of study with high rates of return. Evidence from a study made in Dijon in 1974 is summarised and offers support for the suggested choice model.