The effectiveness of a primer (contact resin) in diminishing marginal leakage of a direct filling resin (isopast)

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The pupal response to an experimental luting resin

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Developing and validating a competence framework for secondary mathematics student teachers through a Delphi method

Initial teacher education programmes provide student teachers with the desired competences to develop themselves as teachers. Although a generic framework for teaching competences is available covering all school subjects in Spain, the initial teacher education programmes curriculum does not specify which competences secondary mathematics student teachers should acquire during their initial teacher education. This explains why this study aimed at developing and validating a competence framework for secondary mathematics student teachers in Spain. Building on existing models and international frameworks, a preliminary list of competences was drawn up. The validation process was based on a Delphi method. Besides experts expressed their opinions about the formulation of the chosen competences. A comprehensive framework of thirty-three competences for secondary mathematics student teachers could be validated

Pulpal responses to two luting cements

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Exploring the effectiveness of video-vignettes to develop mathematics student teachers’ feedback competence

The ability to give constructive, purposeful and timely feedback is essential to the teaching profession. Research indicates that this competence remains underdeveloped during initial teacher education. This paper focuses on the design, implementation, and evaluation of a competence development intervention with secondary mathematics student teachers. The intervention builds on videotaped response-based simulations. A pre-test/post-test design was used. Mathematics student teachers were invited to respond to open-ended questions while watching a series of video-vignettes which focused on providing feedback to students in different real-life classroom situations. Content analysis of student teachers’ answers helped us map changes in their feedback competence development. A scale was developed to capture their related feedback self-efficacy. The results indicate that the intervention had a positive impact on the development of mathematics student teachers’ feedback competence. Implications and directions for future research are discussed

Hubble Space Telescope Survey of the Perseus Cluster: II. Photometric scaling relations in different environments

We investigate the global photometric scaling relations traced by early-type galaxies in different environments, ranging from dwarf spheroidals, over dwarf elliptical galaxies, up to giant ellipticals (-8 mag > M_V > -24 mag). These results are based in part on our new HST/ACS F555W and F814W imagery of dwarf spheroidal galaxies in the Perseus Cluster. These scaling relations are almost independent of environment, with Local Group and cluster galaxies coinciding in the various diagrams. We show that at M_V ~ -14 mag, the slopes of the photometric scaling relations involving the Sersic parameters change significantly. We argue that these changes in slope reflect the different physical processes that dominate the evolution of early-type galaxies in different mass regimes. As such, these scaling relations contain a wealth of information that can be used to test models for the formation of early-type galaxies.Comment: accepted for publication by MNRA

The degeneracy between star-formation parameters in dwarf galaxy simulations and the Mstar-Mhalo relation

We present results based on a set of N-Body/SPH simulations of isolated dwarf galaxies. The simulations take into account star formation, stellar feedback, radiative cooling and metal enrichment. The dark matter halo initially has a cusped profile, but, at least in these simulations, starting from idealised, spherically symmetric initial conditions, a natural conversion to a core is observed due to gas dynamics and stellar feedback. A degeneracy between the efficiency with which the interstellar medium absorbs energy feedback from supernovae and stellar winds on the one hand, and the density threshold for star formation on the other, is found. We performed a parameter survey to determine, with the aid of the observed kinematic and photometric scaling relations, which combinations of these two parameters produce simulated galaxies that are in agreement with the observations. With the implemented physics we are unable to reproduce the relation between the stellar mass and the halo mass as determined by Guo et al. (2010), however we do reproduce the slope of this relation.Comment: Accepted for publication in MNRAS | 12 pages, 8 figure