Zur Motivierung im Informatikunterricht: eine Charakterisierung unterrichtspraktischer Einstiege aus der Perspektive von Lehrenden und Lernenden

Motivierungen ermöglichen es, Lernende für Unterrichtsinhalte zu interessieren und zu begeistern. Diese Arbeit untersucht Motivierung im Informatikunterricht anhand von unterrichtspraktischen Einstiegen. In einer explorativ angelegten Studie werden 12 Typen motivierender Unterrichtseinstiege herausgearbeitet, die eine Bandbreite von Themenbereichen des Informatikunterrichts abdecken. Die Typen motivierender Unterrichtseinstiege werden beschrieben, durch Beispiele illustriert und klassifiziert. Die Hauptuntersuchung erfolgt sowohl aus Lehrer- als auch aus Schülerperspektive. Als theoretische Grundlage dient das um eine didaktische Komponente erweiterte ARCS-Modell der Motivierung nach Keller. Mit Hilfe von Vignetten in Text- und Videoform wird eine Charakterisierung der ermittelten Typen anhand ihrer motivierenden Eigenschaften vorgenommen. Dabei können Top-Gruppen nachgewiesen werden, die einzelne Motivierungsfaktoren in besonderer Weise verkörpern. Hervorzuheben ist, dass die Motivierungstypen Aktuelle Sachverhalte erörtern, Entwicklung von Informatiksystemen als Ziel vorgeben und der Kopplungstyp Entwicklung von Informatiksystemen aus dem Alltag als Ziel vorgeben alle untersuchten Motivierungsfaktoren in hoher Ausprägung in sich vereinen (können). Lehrende und Lernende schätzen das Motivierungspotenzial derjenigen Typen als besonders hoch ein, die allgemeinbildende Informatikaspekte verkörpern. Dem Entwickeln von Informatiksystemen aus dem Alltag als vorgegebenes Ziel der Unterrichtseinheit wird von beiden Teilnehmergruppen insgesamt das höchste Motivierungspotenzial beigemessen. Insgesamt kann geschlussfolgert werden, dass Motivierungen im Informatikunterricht erfolgreich auf Schülerinnen und Schüler wirken, wenn sie flexibel mit den Interessen der Jugendlichen arbeiten, sie den Sinn und Zweck der Lernhandlung verkörpern und Möglichkeiten für die Arbeit mit und an Informatiksystemen (er)schaffen

Cut&Carry – Wirkung auf den Boden im Hinblick auf Erosionsschutz und Wassergehalt

Im Projekt VORAN (Verbesserung ökologischer Fruchtfolgen mit Transfermulch für ein angepasstes regeneratives Nährstoffmanagement) wird seit 2019 in Feld- und Gewächshausversuchen im LfULG untersucht, welche Bodenschutzeffekte erzielt werden können

In Vitro Systems for Toxicity Evaluation of Microbial Volatile Organic Compounds on Humans: Current Status and Trends

Microbial volatile organic compounds (mVOC) are metabolic products and by-products of bacteria and fungi. They play an important role in the biosphere: They are responsible for inter- and intra-species communication and can positively or negatively affect growth in plants. But they can also cause discomfort and disease symptoms in humans. Although a link between mVOCs and respiratory health symptoms in humans has been demonstrated by numerous studies, standardized test systems for evaluating the toxicity of mVOCs are currently not available. Also, mVOCs are not considered systematically at regulatory level. We therefore performed a literature survey of existing in vitro exposure systems and lung models in order to summarize the state-of-the-art and discuss their suitability for understanding the potential toxic effects of mVOCs on human health. We present a review of submerged cultivation, air-liquid-interface (ALI), spheroids and organoids as well as multi-organ approaches and compare their advantages and disadvantages. Furthermore, we discuss the limitations of mVOC fingerprinting. However, given the most recent developments in the field, we expect that there will soon be adequate models of the human respiratory tract and its response to mVOCs

A workshop report on the FDNext project funded by the German Research Foundation

Nach zwei Jahren Projektlaufzeit lud der DFG-geförderte Projektverbund FDNext zu einem zweiten Community-Workshop ein. Unter dem Motto „Nachhaltiges Forschungsdatenmanagement gemeinsam umsetzen“ wurde eine projektweite Ergebnisbilanz gezogen und im Rahmen einer Online-Veranstaltung vorgestellt. Einzelne Formate ermöglichten den Austausch und die Diskussion zur Vision des Kulturwandels und eines ganzheitlichen FDMs durch Initiativen wie die Nationale Forschungsdateninfrastruktur (NFDI) sowie die Möglichkeiten der Zusammenarbeit zwischen einzelnen Konsortien und Hochschulen. Dabei wurden Aufgaben identifiziert, welche nur gemeinsam mit der FDM- bzw. Wissenschafts-Community bearbeitet werden können.Two years into the project duration, the collaborative project FDNext convened its second community workshop titled “Implementing Sustainable Research Data Management in a Joint Project”. Focusing on a review of achievements, the online event presented findings from all participating parties. Various formats fostered exchange and debates about perspectives of cultural change and a holistic research data management through initiatives such as the Nationale Forschungsdateninfrastruktur NFDI (national research data infrastructure), as well as collaboration opportunities between individual consortia and universities. Tasks and challenges that can only be dealt with in cooperation with RDM and scientific communities have been identified.Peer Reviewe

Rapid Engineering of Bacterial Reporter Gene Fusions by Using Red Recombination▿ †

Reporter gene fusions are essential tools for the investigation of gene regulation. Such fusions are traditionally generated by transposon mutagenesis and identified by a suitable selection procedure. Alternatively, specific reporter fusions can be generated by cloning of DNA fragments containing promoters or other regulatory elements in reporter plasmids. Here, we describe a novel approach for the rapid generation of reporter gene fusions in single copies at defined positions in bacterial genomes. This technique utilizes the Red recombinase for the homologous recombination of PCR-generated cassettes containing various currently used reporter genes, such as those for β-galactosidase, luciferase, and green fluorescent protein. The approach allows the generation of transcriptional or translational reporter fusions in a single step without the requirement for recombinant DNA constructs and is applicable to various enterobacterial species. Generation of reporter fusions by Red recombination is rapid, overcomes the current limitations of transposon mutagenesis or reporter plasmids, and offers new options for the study of bacterial gene regulation

Rapid Oligonucleotide-Based Recombineering of the Chromosome of Salmonella enterica▿ †

Recombinant engineering using Red recombinase-based approaches offers efficient and rapid approaches to deletion and modification of genes. Here we describe a novel application of Red recombinant engineering that enables direct manipulation of chromosomal loci by electroporation with short synthetic DNA molecules. We demonstrate the use of this approach for the generation of scarless in-frame deletions in chromosomal genes of Salmonella enterica. Furthermore, we describe rapid site-directed mutagenesis within bacterial chromosomes without any requirement for cloning and mutating genes in vitro or for reintroducing mutant alleles into the chromosome. This approach can be expected to facilitate mutational analysis in S. enterica and in other bacterial species able to support Red-mediated recombination

Effect of the O-Antigen Length of Lipopolysaccharide on the Functions of Type III Secretion Systems in Salmonella enterica▿

The virulence of Salmonella enterica critically depends on the functions of two type III secretion systems (T3SS), with the Salmonella pathogenicity island 1 (SPI1)-encoded T3SS required for host cell invasion and the SPI2-T3SS enabling Salmonella to proliferate within host cells. A further T3SS is required for the assembly of the flagella. Most serovars of Salmonella also possess a lipopolysaccharide with a complex O-antigen (OAg) structure. The number of OAg units attached to the core polysaccharide varies between 16 and more than 100 repeats, with a trimodal distribution. This work investigated the correlation of the OAg length with the functions of the SPI1-T3SS and the SPI2-T3SS. We observed that the number of repeats of OAg units had no effect on bacterial motility. The interaction of Salmonella with epithelial cells was altered if the OAg structure was changed by mutations in regulators of OAg. Strains defective in synthesis of very long or long and very long OAg species showed increased translocation of a SPI1-T3SS effector protein and increased invasion. Invasion of a strain entirely lacking OAg was increased, but this mutant strain also showed increased adhesion. In contrast, translocation of a SPI2-T3SS effector protein and intracellular replication were not affected by modification of the OAg length. Mutant strains lacking the entire OAg or long and very long OAg were highly susceptible to complement killing. These observations indicate that the architecture of the outer membrane of Salmonella is balanced to permit sufficient T3SS function but also to confer optimal protection against antimicrobial defense mechanisms

Application of impedance measurement to investigate in vitro inhalation toxicity of bacteria

Abstract Background Workers of agriculture and intensive life stock farming are exposed to highly contaminated workplaces. Bioaerosol exposures are suspected to trigger respiratory health effects of the workers. So far, risk evaluation of bioaerosols has been assessed through the infectivity of comprising biological agents that is classified in Europe by four risk groups according to the criteria of Directive 2000/54EC of the European Parliament. However, this directive additionally requires the risk assessment of allergenic and toxigenic effects without further elaboration. The aim of our study was to establish an in vitro screening system that is able to measure inhalative toxic effects of bacteria and their metabolites. Methods In this study, we analyzed three bacterial toxins and five culture supernatants of selected bacteria with known toxicity as model agents exposed to the lung epithelial cell line NuLi-1. We used electrical cell-substrate impedance sensing (ECIS) method to monitor real-time cell changes and the viability test Prestoblue™. Results We confirmed concentration dependent cytotoxic effects of the selected toxins in NuLi-1 cells over a period of up to 48 h. Each toxin resulted in a different but specific impedance profile over time according to their mode of action, whereas viability assay showed the metabolic activity of the cells at a chosen time point without revealing any information on their mode of action. Furthermore, dose-response-relationships were monitored. Tested model bacteria (Streptoccous pneumoniae, Acinetobacter radioresistens, Aerococcus viridans, Aeromonas hydrophila) reacted according to their expected toxicity except one bacterium (Enterococcus faecalis). The established assays revealed the concentration dependent onset and intensity of bacterial cytotoxicity and the viability of the cells at 24 h and 48 h exposure. Conclusion Impedance measurement and the viability assay Prestoblue™ in combination are suitable as sensitive screening methods to analyze toxic potential of bacteria and can therefor support the risk assessment of workplaces in terms of the directive 2000/54/EC

Application of impedance measurement to investigate in vitro inhalation toxicity of bacteria

Background!#!Workers of agriculture and intensive life stock farming are exposed to highly contaminated workplaces. Bioaerosol exposures are suspected to trigger respiratory health effects of the workers. So far, risk evaluation of bioaerosols has been assessed through the infectivity of comprising biological agents that is classified in Europe by four risk groups according to the criteria of Directive 2000/54EC of the European Parliament. However, this directive additionally requires the risk assessment of allergenic and toxigenic effects without further elaboration. The aim of our study was to establish an in vitro screening system that is able to measure inhalative toxic effects of bacteria and their metabolites.!##!Methods!#!In this study, we analyzed three bacterial toxins and five culture supernatants of selected bacteria with known toxicity as model agents exposed to the lung epithelial cell line NuLi-1. We used electrical cell-substrate impedance sensing (ECIS) method to monitor real-time cell changes and the viability test Prestoblue™.!##!Results!#!We confirmed concentration dependent cytotoxic effects of the selected toxins in NuLi-1 cells over a period of up to 48 h. Each toxin resulted in a different but specific impedance profile over time according to their mode of action, whereas viability assay showed the metabolic activity of the cells at a chosen time point without revealing any information on their mode of action. Furthermore, dose-response-relationships were monitored. Tested model bacteria (Streptoccous pneumoniae, Acinetobacter radioresistens, Aerococcus viridans, Aeromonas hydrophila) reacted according to their expected toxicity except one bacterium (Enterococcus faecalis). The established assays revealed the concentration dependent onset and intensity of bacterial cytotoxicity and the viability of the cells at 24 h and 48 h exposure.!##!Conclusion!#!Impedance measurement and the viability assay Prestoblue™ in combination are suitable as sensitive screening methods to analyze toxic potential of bacteria and can therefor support the risk assessment of workplaces in terms of the directive 2000/54/EC