Medienpädagogische und fachdidaktische Kompetenzmodellierungen für das Lehren und Lernen mit und über digitale Medien

Digitalisierung und Mediatisierung bedingen gesamtgesellschaftliche Transformationsprozesse, die den Bereich der Bildung ebenso durchdringen, wie auch auf die professionelle Kompetenz von Lehrkräften wirken. Der vorliegende Beitrag befasst sich mit der medienbezogenen Ausgestaltung der universitären Bildung von Lehrkräften in Deutschland und formuliert Fragenkomplexe, die transdisziplinär, evidenzbasiert und nachhaltig beantwortet werden müssen. Ausgangspunkt dafür muss eine systematische Betrachtung erforderlicher medienbezogener Kompetenzen von (angehenden) Lehrerinnen und Lehrern sein, die das Kernstück dieses Artikels bildet: Der Beitrag gibt einen Überblick über nationale und internationale Modellierungsansätze von Kompetenzen zum Lehren und Lernen mit und über Medien, um in der Folge drei zentrale Modelle (TPACK, DigCompEdu, M3K) detaillierter und vergleichend zu beschreiben und einen Ausblick auf eine transdisziplinäre Gestaltung der Bildung von Lehrkräften zu geben

Global application of an unoccupied aerial vehicle photogrammetry protocol for predicting aboveground biomass in non‐forest ecosystems

P. 1-15Non-forest ecosystems, dominated by shrubs, grasses and herbaceous plants, provide ecosystem services including carbon sequestration and forage for grazing, and are highly sensitive to climatic changes. Yet these ecosystems are poorly represented in remotely sensed biomass products and are undersampled by in situ monitoring. Current global change threats emphasize the need for new tools to capture biomass change in non-forest ecosystems at appropriate scales. Here we developed and deployed a new protocol for photogrammetric height using unoccupied aerial vehicle (UAV) images to test its capability for delivering standardized measurements of biomass across a globally distributed field experiment. We assessed whether canopy height inferred from UAV photogrammetry allows the prediction of aboveground biomass (AGB) across low-stature plant species by conducting 38 photogrammetric surveys over 741 harvested plots to sample 50 species. We found mean canopy height was strongly predictive of AGB across species, with a median adjusted R2 of 0.87 (ranging from 0.46 to 0.99) and median prediction error from leave-one-out cross-validation of 3.9%. Biomass per-unit-of-height was similar within but different among, plant functional types. We found that photogrammetric reconstructions of canopy height were sensitive to wind speed but not sun elevation during surveys. We demonstrated that our photogrammetric approach produced generalizable measurements across growth forms and environmental settings and yielded accuracies as good as those obtained from in situ approaches. We demonstrate that using a standardized approach for UAV photogrammetry can deliver accurate AGB estimates across a wide range of dynamic and heterogeneous ecosystems. Many academic and land management institutions have the technical capacity to deploy these approaches over extents of 1–10 ha−1. Photogrammetric approaches could provide much-needed information required to calibrate and validate the vegetation models and satellite-derived biomass products that are essential to understand vulnerable and understudied non-forested ecosystems around the globe.S

Split-Cre Complementation Indicates Coincident Activity of Different Genes In Vivo

Cre/LoxP recombination is the gold standard for conditional gene regulation in mice in vivo. However, promoters driving the expression of Cre recombinase are often active in a wide range of cell types and therefore unsuited to target more specific subsets of cells. To overcome this limitation, we designed inactive “split-Cre” fragments that regain Cre activity when overlapping co-expression is controlled by two different promoters. Using transgenic mice and virus-mediated expression of split-Cre, we show that efficient reporter gene activation is achieved in vivo. In the brain of transgenic mice, we genetically defined a subgroup of glial progenitor cells in which the Plp1- and the Gfap-promoter are simultaneously active, giving rise to both astrocytes and NG2-positive glia. Similarly, a subset of interneurons was labelled after viral transfection using Gad67- and Cck1 promoters to express split-Cre. Thus, split-Cre mediated genomic recombination constitutes a powerful spatial and temporal coincidence detector for in vivo targeting