THE PRINCIPAL’S PERCEIVED ROLE IN TEACHER ASSESSMENT PRACTICES

The purpose of this study was to explore the principal’s perception of their role within the context of classroom assessments. Effective assessment practices have demonstrated the most consistent positive impact on student achievement. Research on the specific role of the principal in the process of classroom assessment is limited. This study used a qualitative methodology. Eight elementary principals with at least five years of experience were interviewed from both rural and urban schools in Southwestern Ontario. Interviews were conducted face-to-face using a semi-structured format. There were three key findings from the study. Principals ’levels of assessment literacy varied, from having a very limited understanding of assessment literacy to a more comprehensive understanding. Principals had a very limited view of the elements o fa sound assessment system, and the link between classroom and wide-scale assessments and reporting systems. Principals considered their role as more of a manager than an educational leader. There are two recommendations offered: first, at the provincial level, that the government of Ontario develop more resources that include a common language about assessment and for the development of assessment literacy of the educational community; and second, that the local board look at the role of the principal from a leadership positio

Relations between organic and terrigenous matter deposition in Holocene fluvial sediments: heterodox observations and conclusions.

International audienceAccumulation of organic matter in fens of fluvial valleys is often related to a low terrigenous matter delivery and to palaeoenvironmental conditions inducing low mechanical erosion. These assumptions come from the interpretation of contents in organic (MO) and mineral (MM) matters in sediments, expressed in percents, and then exactly anticorrelated. Calculation of mass accumulation rates of MO (TaMO) and MM (TaMM), expressed in g m−2 yr−1, shows that TaMO and TaMM generally are not anticorrelated and that high values of TaMO and TaMM could appear simultaneously. That expression of MO and MM accumulation makes it possible to precise the climatic and human impact on sedimentation

Classification and mapping of anthropogenic landforms on cultivated hillslopes using DEMs and soil thickness data - Example from the SW Parisian Basin, France

International audienceThis study focuses on linear anthropogenic landforms of decametric width on cultivated hillslopes and their relations to soil thickness variability. The 16 ha study area shows a rolling topography supported by Cretaceous chalk of the SW Parisian Basin, France. Two types of landforms were identified: lynchets, similar to those described as soil terraces occurring on downslope field parts in other contexts, and undulations, linear, convex landforms that cut across fields. Accurate DEM construction and a detailed soil thickness survey were performed all over the study area. Soil samples were classified considering their location on specific types of anthropogenic landforms. The classification tree (CT) method was applied to assess whether lynchets and undulations can be discriminated through morphometric attributes (slope, curvature, profile curvature and planform curvature) and soil thickness (CTsoil) or through morphometric attributes only (CTtopo). The CT application establishes predictive classification models to map the spatial distribution of lynchets and undulations over the whole study area. The validation results of the CTsoil and CTtopo applications show model efficiencies of 83% and 67%, respectively. Both models performed well for lynchets. Errors arise mainly from difficulties in unequivocally discriminating gently convex undulations and undifferentiated surfaces, especially when soil thickness is not accounted for. Mean values of soil thickness are 1.08, 0.62 and 0.45 m in lynchets, undulations and undifferentiated areas, respectively. The general shape of the thickened soil is characteristic to each type of anthropogenic landform. Multi-temporal mapping of field border networks shows that undulations are linked to borders that were removed during the latest land consolidation. Lynchets are associated with current field borders. Lynchets and undulations, which cover 39% of the study area, define topographic indicators of human-induced soil accumulations. The method involves perspectives for efficiently mapping and quantifying the anthropogenically modified spatial variability of soil thickness on agricultural hillsides

Relation between magnetization and Faraday angles produced by ultrafast spin-flip processes within the three-level A-type system

Ultrafast magneto-optical (MO) experiments constitute a powerful tool to explore the magnetization dynamics of diverse materials. Over the last decade, there have been many theoretical and experimental developments on this subject. However, the relation between the magnetization dynamics and the transient MO response still remains unclear. In this work, we calculate the magnetization of a material, as well as the magneto-optical rotation and ellipticity angles measured in a single-beam experiment. Then, we compare the magnetization to the MO response. The magnetic material is modeled by a three-level A-type system, which represents a simple model to describe MO effects induced by an ultrafast laser pulse. Our calculations use the density matrix formalism, while the dynamics of the system is obtained by solving the Lindblad equation taking into account population relaxation and dephasing processes. Furthermore, we consider the Faraday rotation of the optical waves that simultaneously causes spin-flip. We show that the Faraday angles remain proportional to the magnetization only if the system has reached the equilibrium-state, and that this proportionality is directly related to the population and coherence decay rates. For the non-equilibrium situation, the previous proportionality relation is no longer valid. We show that our model is able to interpret some recent experimental results obtained in a single-pulse experiment. We further show that, after a critical pulse duration, the decrease of the ellipticity as a function of the absorbed energy is a characteristic of the system

Effet de l'évolution du parcellaire agricole sur la redistribution des sols et la morphologie des versants cultivés (exemple du sud-ouest du Bassin parisien)

L évolution historique des types et techniques de production agricole a causé celle de l organisation paysagère, via les parcellaires notamment. Les bordures de parcelles créent des discontinuités dans les processus d érosion-dépôt de sol. L objectif est ici de comprendre l effet du parcellaire et de son évolution sur la distribution actuelle des sols et la morphologie des versants. Un versant cultivé (16 ha) dans le SW du Bassin Parisien a été étudié. La distribution spatiale de figures morphologiques linéaires et de l épaisseur des sols a été analysée. Les deux types de figures identifiés correspondent à des épaississements de sols (dépôts) induits par des bordures de parcelles, pérennes depuis plusieurs siècles pour les premières, et disparues en 1967 (remembrement) pour les secondes. Ces épaississements ont été cartographiés grâce à une analyse statistique (CART) de la morphologie du versant. L étude de traceurs granulométriques et minéralogiques (SEDI) a permis d identifier les processus d érosion-dépôt impliqués. La solifluxion périglaciaire puis le ruissellement auraient affecté l ensemble du versant avant la pérennisation d un parcellaire. Puis, des processus hydriques et aratoires ont agi dans des unités (parcelles) fixées par des bordures : les plus pérennes (1000 ans) montrent les dépôts les plus marqués (banquettes). La distribution spatiale du 137Cs et sa conversion en taux d érosion (modélisation numérique) ont permis d évaluer l implication relative des processus hydriques (15%) et aratoires (85%) depuis 1954. Le remembrement parcellaire de 1967 s avère avoir favorisé l érosion des sols, convertissant des zones de rétention en zones sources (ondulations).The historical evolution of agricultural practices is associated with a concomitent evolution of landscape spatial organisation, especially through field-border networks. Field borders create discontinuities of soil erosion-deposition processes. The aim of this PhD is to understand the effects of field-border networks and their evolution on the present spatial distribution of soils and hillslope morphology. A cultivated hillslope (16 ha) of the SW Parisian Basin was studied. The spatial distribution of linear landforms and soil thickness was analyzed. The two types of identified landforms correspond to soil thickenings (deposition) induced by field borders, that have existed for several centuries in the case of the first ones, and disappeared during a land consolidation (1967) in the case of the second ones. These soil thickenings were mapped through a statistical analysis (CART) of the hillslope morphology. The study of granulometric and mineralogical tracers (SEDI) led to identify the involved soil redistribution processes. Periglacial solifluxion, followed by runoff, probably occured over the whole hillslope before the establishment of perennial field borders. Then, water and tillage processes occured within areas delimited by field borders. The more developed soil depositions (lynchets) are linked with the most perennial borders (i.e., 1000 yrs). The spatial distribution of 137Cs and its conversion into erosion rates (numerical modeling) allowed to assess the relative implication of water (15%) and tillage processes (85%) since 1954. The land consolidation that occured in 1967 rised soil erosion when converting soil retention areas to sources (undulations).TOURS-Bibl.électronique (372610011) / SudocSudocFranceF

Contribution of bathymetry and geomorphology to the geodynamics of the East Indonesian seas

La compilation des données existantes et de celles recueillies dans le cadre de la coopération franco-indonésienne permet de présenter une nouvelle image bathymétrique des bassins océaniques de l’Est indonésien. La morphologie sert aussi de base aux études structurales menées à partir des données géophysiques insuffisamment denses. 3 bassins océaniques se sont ouverts successivement du NW au SE : le bassin Nord Banda (Sula) en position arrière arc, le bassin Sud Banda (Wetar et Damar) qui s’est ouvert au sein de l’arc volcanique et le bassin de Weber en position d’avant arc. La morphologie permet de préciser la direction d’ouverture NW-SE de ces bassins, en particulier dans le bassin de Sula où des accidents de cette direction, comme la zone de fracture de Tampomas sont mis en évidence. La carte bathymétrique permet aussi d’avancer des hypothèses sur la signification des rides de Banda qui séparent les bassins nord et sud. La succession d’ouverture de bassins est liée à la subduction australienne et à son recul. Le trait majeur de ces bassins est leur grande profondeur en regard de leur âge récent, qui ne s’intègre pas dans les modèles de subsidence thermique établis pour les grands océans ou pour les bassins marginaux. La situation géodynamique exceptionnelle qui place ces bassins au-dessus de plusieurs panneaux froids subductés et dans une région de collision active joue vraisemblablement un rôle important

7-(2-Chloro­phen­yl)-2,6,9-trimethyl­dibenzo[b,h][1,6]naphthyridine

In the title compound, C25H19ClN2, the dibenzo[b,h][1,6]naphthyridine system is planar to within 0.16 (2) Å, and the chloro­phenyl ring is inclined to it by 82.53 (7)°. In the crystal, mol­ecules are linked by C—H⋯N hydrogen bonds, forming chains propagating in [100]. There are also a number of weak π–π stacking inter­actions present [centroid–centroid distances = 3.8531 (1) and 3.7631 (1) Å]