Overabundant ungulates in French Sologne? Increasing red deer and wild boar pressure may not threaten woodland birds in mature forest stands

Increasing ungulate populations have been considered to drive changes in woodland bird communities in temperate and boreal forests. Ungulates may negatively affect understory-dependent woodland birds either directly or indirectly. For instance ungulates may prey on nests, or they may reduce the availability of nesting sites, foraging resources or cover for understory-dependent bird species. We conducted ungulate pressure, vegetation and bird surveys on 95 plots, in nineteen mature forest stands (9 fenced and 10 unfenced properties) located in the Sologne region (France). In such private forests, ungulate population densities are highly variable; we were therefore able to explore the effects of varying red deer (Cervus elaphus) browsing and wild boar (Sus scrofa) rooting intensity on bird communities. Bayesian Binomial mixture models indicated that ground-nesting birds were more abundant in forests with high observed wild boar rooting intensity. Generally, increasing deer browsing pressure did not have any negative effect on woodland birds in mature forest stands with a developed canopy, and did not result in lower shrub cover. Most previous studies documenting a negative effect of browsing on birds focused on young forest stands where overstory vegetation was scarce. Our results suggest that the impact of ungulate pressure on forest birds may decrease with forest stand age

Enseignement des sciences et de la technologie fondé sur l’investigation au collège

Dans le cadre des nouveaux programmes mis en place au collège depuis la rentrée 2006, les prescriptions institutionnelles envisagent l’apprentissage des sciences et de la technologie par une démarche d’investigation considérée comme méthode d’enseignement privilégiée (B.O.E.N. Hors Série n°5 du 25 août 2005, p 6). Cette recherche vise à identifier quelle mise en œuvre a lieu effectivement dans les classes par les enseignants de sciences physiques et de technologie au collège. Il s’agit de regarder si le travail d'un groupe d'enseignants et de chercheurs permet de mettre en évidence les enjeux d'un enseignement fondé sur l'investigation, et les conditions favorisant sa mise en œuvre par les praticiens

Augmented Reality for Teacher Education faculties (ARTEfac): images of the Earth-sun model

International audienceIn France, primary school science curricula (equivalent P4 to P6) includes astronomical content knowledge about the movement of the Earth to explain the seasons. However, researches about students' knowledge have highlighted misconceptions when explaining the phenomenon of seasons, often related to the distance model (varying distance between the Earth and the Sun), associated to highly elliptical images of the Earth orbit about the Sun commonly depicted in print or on the internet. The question of which images can be used during teacher education programs arises, especially in a context where learners are exposed to multiple modes of representations. Teacher educators' institutions are challenged with the need to develop resources to prepare future teachers to teach in a multimodal environment. The idea of the present research is to use augmented reality (AR), and in particular 3D animated images to help students to visualize the Earth-Sun model and better understand the phenomenon of seasons. A team of educational researchers, teacher educators, technicians and developers worked together to design 3D images of the Earth-Sun model and the associated modeling application. The objective of this research is to question the role of 3D animated images in students' understanding of the phenomenon of seasons, based on the evolution of their representations. A preliminary qualitative research has been conducted with 4 teacher students in primary education in France in order to question their prior representations (Q1) and how they evolved while working with 3D animated images in AR (Q2). Through designated questions, their prior knowledge of astronomical concepts was assessed (Q1). Training sessions using the 3D animated images were videotaped to analyze the relationship between students' prior representations and the explanatory models they developed based on the use of 3D animated images in AR (Q2). The data highlights interesting interactions between students use of the 3D images, speak and gestures. First results show an improvement in the way students explain the phenomenon of seasons, but also a recognition of the visual and conceptual difficulties their pupils will have, and the interest of visualization using 3D animated images in AR in primary science classrooms

Influence of Augmented Reality activities on students’ cognitive load and learning outcomes.

International audienc

Influence of Augmented Reality activities on students' cognitive load

International audienceThe ARTEfac project is a web solution developed by researchers and engineers from Aix-Marseille University and a private company. The solution is composed of a Backoffice for scenarios' designers and a mobile user application. An Augmented Reality (AR) science learning scenario has been designed for university students allowing them to build knowledge about Earth's seasons. The scenario included an interactive AR model representing the earth revolution around the sun using 3D objects. The users had the possibility to interact with the model like stopping the revolution and rotation, changing the earth inclination, etc. A quasi-experimental approach was used to investigate the impact of an AR model on the students' cognitive load, short-term and long-term learning outcomes. A test group composed of 24 students learnt Earth's seasons through the AR model while the 24 students control group learnt the topic with images and diagrams. A self-assessment of cognitive load has been used during the learning tasks and pre, post and retention questionnaires assessed the students' knowledge about Earth' seasons. According to the previous literature, we expect to find significant higher cognitive load for the control group (based on Wilcoxon rank-sum test) whereas the test group would outperform the control group in retention test. The post-test could be not significantly different. All these results will be discussed according to their limitations and the previous studies done in the same field

VERS UNE PRODUCTION D’OUTILS DE FORMATION EN SCIENCES ET TECHNOLOGIE POUR LE PREMIER DEGRE

Les travaux s'appuient en particulier sur les orientations actuelles en termes de prescriptions en lien avec la mise en œuvre d'un enseignement des sciences par investigation et s'appuient sur de nombreux travaux à ce sujet. Des séquences d'enseignement sont conçues en vue de créer des outils de formation où une attention particulière est portée à la notion de débat scientifique, qui fait partie des stratégies didactiques très étudiées dans la recherche en éducation scientifique

Characterization of the Bubblegum acyl-CoA synthetase of Microchloropsis gaditana

International audienceThe metabolic pathways of glycerolipids are well described in cells containing chloroplasts limited by a two-membrane en-velope but not in cells containing plastids limited by four membranes, including heterokonts. Fatty acids (FAs) producedin the plastid, palmitic and palmitoleic acids (16:0 and 16:1), are used in the cytosol for the synthesis of glycerolipids viavarious routes, requiring multiple acyl-Coenzyme A (CoA) synthetases (ACS). Here, we characterized an ACS of theBubblegum subfamily in the photosynthetic eukaryote Microchloropsis gaditana, an oleaginous heterokont used for theproduction of lipids for multiple applications. Genome engineering with TALE-N allowed the generation of MgACSBGpoint mutations, but no knockout was obtained. Point mutations triggered an overall decrease of 16:1 in lipids, a specificincrease of unsaturated 18-carbon acyls in phosphatidylcholine and decrease of 20-carbon acyls in the betaine lipid diacyl-glyceryl–trimethyl–homoserine. The profile of acyl-CoAs highlighted a decrease in 16:1-CoA and 18:3-CoA. Structuralmodeling supported that mutations affect accessibility of FA to the MgACSBG reaction site. Expression in yeast defectivein acyl-CoA biosynthesis further confirmed that point mutations affect ACSBG activity. Altogether, this study supports acritical role of heterokont MgACSBG in the production of 16:1-CoA and 18:3-CoA. In M. gaditana mutants, the excess satu-rated and monounsaturated FAs were diverted to triacylglycerol, thus suggesting strategies to improve the oil content inthis microalg