A critical reflection on computing the sampling variance of the partial correlation coefficient

The partial correlation coefficient quantifies the relationship between two variables while taking into account the effect of one or multiple control variables. Researchers often want to synthesize partial correlation coefficients in a meta-analysis since these can be readily computed based on the reported results of a linear regression analysis. The default inverse variance weights in standard meta-analysis models require researchers to compute not only the partial correlation coefficients of each study but also its corresponding sampling variance. The existing literature is diffuse on how to estimate this sampling variance, because two estimators exist that are both widely used. We critically reflect on both estimators, study their statistical properties, and provide recommendations for applied researchers. We also compute the sampling variances of studies using both estimators in a meta-analysis on the partial correlation between self-confidence and sports performance

Phase behaviour of binary mixtures of diamagnetic colloidal platelets in an external magnetic field

Using fundamental measure density functional theory we investigate paranematic-nematic and nematic-nematic phase coexistence in binary mixtures of circular platelets with vanishing thicknesses. An external magnetic field induces uniaxial alignment and acts on the platelets with a strength that is taken to scale with the platelet area. At particle diameter ratio lambda=1.5 the system displays paranematic-nematic coexistence. For lambda=2, demixing into two nematic states with different compositions also occurs, between an upper critical point and a paranematic-nematic-nematic triple point. Increasing the field strength leads to shrinking of the coexistence regions. At high enough field strength a closed loop of immiscibility is induced and phase coexistence vanishes at a double critical point above which the system is homogeneously nematic. For lambda=2.5, besides paranematic-nematic coexistence, there is nematic-nematic coexistence which persists and hence does not end in a critical point. The partial orientational order parameters along the binodals vary strongly with composition and connect smoothly for each species when closed loops of immiscibility are present in the corresponding phase diagram.Comment: 9 pages, to appear in J.Phys:Condensed Matte

Efficient Expression of Naked Plasmid DNA in Mucosal Epithelium: Prospective for the Treatment of Skin Lesions

Mucocutaneous gene therapy offers exciting new treatment modalities for skin lesions. Transient expression of naked plasmid DNA could be used as a local treatment of various skin lesions where the corresponding gene product (protein) has therapeutic or immunization potential. We analyzed the time course, magnitude, and histologic expression of the indicator plasmid DNA (pCMV:β-Gal) in mucosal epithelium and papilloma lesions. Upon direct injection of naked plasmid DNA (20 μg) into oral mucosa, expression occurred at high local concentrations, up to 35-fold higher than in comparable injections into the epidermis. Due to the accelerated turnover of mucosal epithelium β-galactosidase positive epithelial cells were detected in the basal and suprabasal layers as early as 3 h after injection, whereas only the most superficial mucosal layers demonstrated β-galactosidase staining at 24 h post-injection. These biologic characteristics need to be taken into consideration when clinical applications of expressing naked plasmid DNA in epithelial tissues are considered

A hard-sphere model on generalized Bethe lattices: Statics

We analyze the phase diagram of a model of hard spheres of chemical radius one, which is defined over a generalized Bethe lattice containing short loops. We find a liquid, two different crystalline, a glassy and an unusual crystalline glassy phase. Special attention is also paid to the close-packing limit in the glassy phase. All analytical results are cross-checked by numerical Monte-Carlo simulations.Comment: 24 pages, revised versio

Structural motifs of biomolecules

Biomolecular structures are assemblies of emergent anisotropic building modules such as uniaxial helices or biaxial strands. We provide an approach to understanding a marginally compact phase of matter that is occupied by proteins and DNA. This phase, which is in some respects analogous to the liquid crystal phase for chain molecules, stabilizes a range of shapes that can be obtained by sequence-independent interactions occurring intra- and intermolecularly between polymeric molecules. We present a singularityfree self-interaction for a tube in the continuum limit and show that this results in the tube being positioned in the marginally compact phase. Our work provides a unified framework for understanding the building blocks of biomolecules.Comment: 13 pages, 5 figure

Unified theory for Goos-H\"{a}nchen and Imbert-Fedorov effects

A unified theory is advanced to describe both the lateral Goos-H\"{a}nchen (GH) effect and the transverse Imbert-Fedorov (IF) effect, through representing the vector angular spectrum of a 3-dimensional light beam in terms of a 2-form angular spectrum consisting of its 2 orthogonal polarized components. From this theory, the quantization characteristics of the GH and IF displacements are obtained, and the Artmann formula for the GH displacement is derived. It is found that the eigenstates of the GH displacement are the 2 orthogonal linear polarizations in this 2-form representation, and the eigenstates of the IF displacement are the 2 orthogonal circular polarizations. The theoretical predictions are found to be in agreement with recent experimental results.Comment: 15 pages, 3 figure

Mixité en Education Physique et Sportive: Evolution de la motivation des élèves dans le cadre d’un enseignement mixte au cours d’un cycle de danse

Dans le cadre de notre formation en EPS, nous nous sommes intéressés à l’engagement des élèves dans les classes mixtes. Cette question de l’engagement dans un contexte mixte semblait important à nos yeux, dans un contexte d’enseignement de plus en plus en classes mixtes dans le Canton de Vaud. Il nous semblait judicieux de porter notre regard sur les variations de la motivation des élèves dans ce cas de figure, notamment dans les activités fortement connotées par genre (football, danse, …). La motivation en EPS a été investiguée par de nombreux auteurs. Nous avons choisi de porter la focale sur les effets éventuels du guidage de l’enseignant, du travail par petits groupes, de la création de sens par l’engagement des élèves dans un projet et de l’utilisation de la tablette numérique dans le processus d’apprentissage des élèves. Nous avons réalisé une étude avec deux classes de 9H sur 17 leçons, dans une activité connotée féminine (danse). Nous avons procédé à des observations, soutenues par trois focus groups et deux questionnaires (MIXEPS et ISEP). Des indicateurs ont été définis pour mesurer les variations de motivation des élèves, permettant de repérer les effets potentiels des différentes variables : guidage de l’enseignant, travail par petits groupes, projet et utilisation de la tablette numérique. Les résultats montrent que le guidage de l’enseignant et la mise en projet ont un impact positif sur l’évolution de la motivation au cours du cycle. Il est plus difficile de conclure avec certitude que l’enseignement par petits groupes et l’utilisation de la tablette génèrent une motivation plus importante. D’un point de vue professionnel, cette étude souligne l’importance du sens des apprentissages par le biais de la mise en projet ainsi que l’attention à porter sur l’évolution des élèves afin d’adapter les formes de guidage au plus près de cette évolution

ICME international survey on teachers working and learning through collaboration

This article presents preliminary results from a survey commissioned for ICME 13 (2016) focusing on "Teachers Working and Learning Through Collaboration". It takes as a starting point a previous survey, commissioned for ICME 10 in 2004 that focused on Mathematics Teacher Education. The current survey focuses centrally on teachers involved in collaborations, sometimes in formal settings of professional development, but also in a more diverse range of collaborative settings including research initiatives. The roles of teachers involved in the collaboration, survey methods, decisions and limitations are described. While some of the findings to date resonate with those of the earlier survey, other findings highlight characteristics and issues relating to the differing ways in which teachers collaborate, either with other teachers or the various 'others', most notably mathematics teacher educator researchers. The roles and relationships that contribute to learning in such collaborations, as well as theories and methodologies found in survey sources, are a focus of the findings presented here. Studies rarely theorised collaboration, and few of those that did so reported explicitly on how their theoretical frame shaped the design of research methodologies/approaches guiding activities with teachers. One significant outcome has been the difficulty of relating teachers' learning to collaboration within a project, although many initiatives report developments in teaching, teacher learning and students' learning