48 research outputs found

    Naar een praktische adaptieve aanpak voor spreekvaardigheidsonderwijs in moderne vreemde talen

    Get PDF
    A teaching method will only be implemented in the classroom if it is not only of benefit to students but is also practicable for teachers. In this contribution we propose an adaptive teaching method for speaking skills in foreign languages. To make it practicable, we used the Bridging Model which assumes that regular teaching and the new method are shaped around the same lesson segments. By recombination of these segments teachers can adapt the new method to their teaching context. Based on questionnaires and visual representations of lessons, we examined how and with which considerations 13 teachers enacted the method in practice. Furthermore, the practicability was examined using impact analysis. Results show that the teachers succeeded in applying the method in practice and found the adaptive method to be significantly more desirable than their regular teaching. The flexibility of the method could be an ingredient for curriculum reforms in general.Theoretical and Experimental Linguistic

    Isolation and Characterization of a Mn(II)-Oxidizing Bacillus Strain from the Demosponge Suberites domuncula

    Get PDF
    In this study we demonstrate that the demosponge Suberites domuncula harbors a Mn(II)-oxidizing bacterium, a Bacillus strain, termed BAC-SubDo-03. Our studies showed that Mn(II) stimulates bacterial growth and induces sporulation. Moreover, we show that these bacteria immobilize manganese on their cell surface. Comparison of the 16S rDNA sequence allowed the grouping of BAC-SubDo-03 to the Mn-precipitating bacteria. Analysis of the spore cell wall revealed that it contains an Mn(II)-oxidizing enzyme. Co-incubation studies of BAC-SubDo-03 with 100 μM MnCl2 and >1 μM of CuCl2 showed an increase in their Mn(II)-oxidizing capacity. In order to prove that a multicopper oxidase-like enzyme(s) (MCO) exists in the cell wall of the S. domuncula-associated BAC-SubDo-03 Bacillus strain, the gene encoding this enzyme was cloned (mnxG-SubDo-03). Sequence alignment of the deduced MCO protein (MnxG-SubDo-03) revealed that the sponge bacterium clusters together with known Mn(II)-oxidizing bacteria. The expression of the mnxG-SubDo-03 gene is under strong control of extracellular Mn(II). Based on these findings, we assume that BAC-SubDo-03 might serve as a Mn reserve in the sponge providing the animal with the capacity to detoxify Mn in the environment. Applying the in vitro primmorph cell culture system we could demonstrate that sponge cells, that were co-incubated with BAC-SubDo-03 in the presence of Mn(II), show an increased proliferation potential

    Increasing Costs Due to Ocean Acidification Drives Phytoplankton to Be More Heavily Calcified: Optimal Growth Strategy of Coccolithophores

    Get PDF
    Ocean acidification is potentially one of the greatest threats to marine ecosystems and global carbon cycling. Amongst calcifying organisms, coccolithophores have received special attention because their calcite precipitation plays a significant role in alkalinity flux to the deep ocean (i.e., inorganic carbon pump). Currently, empirical effort is devoted to evaluating the plastic responses to acidification, but evolutionary considerations are missing from this approach. We thus constructed an optimality model to evaluate the evolutionary response of coccolithophorid life history, assuming that their exoskeleton (coccolith) serves to reduce the instantaneous mortality rates. Our model predicted that natural selection favors constructing more heavily calcified exoskeleton in response to increased acidification-driven costs. This counter-intuitive response occurs because the fitness benefit of choosing a better-defended, slower growth strategy in more acidic conditions, outweighs that of accelerating the cell cycle, as this occurs by producing less calcified exoskeleton. Contrary to the widely held belief, the evolutionarily optimized population can precipitate larger amounts of CaCO3 during the bloom in more acidified seawater, depending on parameter values. These findings suggest that ocean acidification may enhance the calcification rates of marine organisms as an adaptive response, possibly accompanied by higher carbon fixation ability. Our theory also provides a compelling explanation for the multispecific fossil time-series record from ∼200 years ago to present, in which mean coccolith size has increased along with rising atmospheric CO2 concentration

    Comparative genomics of Pseudomonas fluorescens subclade III strains from human lungs

    Full text link
    Abstract Background While the taxonomy and genomics of environmental strains from the P. fluorescens species-complex has been reported, little is known about P. fluorescens strains from clinical samples. In this report, we provide the first genomic analysis of P. fluorescens strains in which human vs. environmental isolates are compared. Results Seven P. fluorescens strains were isolated from respiratory samples from cystic fibrosis (CF) patients. The clinical strains could grow at a higher temperature (>34 °C) than has been reported for environmental strains. Draft genomes were generated for all of the clinical strains, and multi-locus sequence analysis placed them within subclade III of the P. fluorescens species-complex. All strains encoded type- II, −III, −IV, and -VI secretion systems, as well as the widespread colonization island (WCI). This is the first description of a WCI in P. fluorescens strains. All strains also encoded a complete I2/PfiT locus and showed evidence of horizontal gene transfer. The clinical strains were found to differ from the environmental strains in the number of genes involved in metal resistance, which may be a possible adaptation to chronic antibiotic exposure in the CF lung. Conclusions This is the largest comparative genomics analysis of P. fluorescens subclade III strains to date and includes the first clinical isolates. At a global level, the clinical P. fluorescens subclade III strains were largely indistinguishable from environmental P. fluorescens subclade III strains, supporting the idea that identifying strains as ‘environmental’ vs ‘clinical’ is not a phenotypic trait. Rather, strains within P. fluorescens subclade III will colonize and persist in any niche that provides the requirements necessary for growth.http://deepblue.lib.umich.edu/bitstream/2027.42/116129/1/12864_2015_Article_2261.pd

    The SpeakTeach method: Towards self-regulated learning of speaking skills in foreign languages in secondary schools: an adaptive and practical approach

    No full text
    The SpeakTeach method, Towards self-regulated learning of speaking skills in foreign languages in secondary schools: an adaptive and practical approach De SpeakTeach didactiek, Naar zelfregulerend leren bij spreek- en gespreksvaardigheid in moderne vreemde talen in het voortgezet onderwijs: een adaptieve en praktische aanpakDudoc AlfaTeaching and Teacher Learning (ICLON

    De SpeakTeach-didactiek

    No full text
    Adaptieve feedback op individuele spreekprestaties in klassen van dertig leerlingen, hoe is dat nou mogelijk? Met SpeakTeach: een didactiek voor adaptieve feedback en gedifferentieerde activiteiten ter verbetering van spreek- en gespreksvaardigheid moderne vreemde talen.Teaching and Teacher Learning (ICLON

    Manganese reduction by a marine Bacillus species.

    No full text
    Mature dormant spores of marine Bacillus sp. strain SG1 catalyze the oxidation of Mn(II) to MnO2. We report that vegetative cells of the same strain reduced MnO2 under low-oxygen conditions. The rate of reduction was a function of cell concentration. The process had a pH optimum of 7.5 to 8.0 and was inhibited by HgCl2, by preheating of the cells at 80 degrees C for 5 min, by antimycin A, and by N-heptyl-hydroxy-quinoline-N-oxide. At a nonlimiting O2 concentration, little MnO2 reduction was observed. Under these conditions, the process could be induced by the addition of NaN3. Spectrophotometric analysis of the Bacillus cells indicated the presence of type b and c cytochromes. Both types can be oxidized in situ by addition of MnO2 to the cells

    Moderne Vreemde Talen

    No full text
    Theoretical and Experimental Linguistic
    corecore