Interview with German Media Theorist Vera Tollmann on View from Above By Geert Lovink This interview was previously published on October 11, 2023 on Geert Lovink’s blog, Net Critique, at: https://networkcultures.org/geert/2023/10/11/interview-with-german-media-theorist-vera-tollmann-on-view-from-above/
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The transition to a biobased economy necessitates utilizing renewable resources as a sustainable alternative to traditional fossil fuels. Bioconversion is a way to produce many green chemicals from renewables, e.g., biopolymers like PHAs. However, fermentation and bioconversion processes mostly rely on expensive, and highly refined pure substrates. The utilization of crude fractions from biorefineries, especially herbaceous lignocellulosic feedstocks, could significantly reduce costs. This presentation shows the microbial production of PHA from such a crude stream by a wild-type thermophilic bacterium Schlegelella thermodepolymerans [1]. Specifically, it uses crude xylose-rich fractions derived from a newly developed biorefinery process for grassy biomasses (the ALACEN process). This new stepwise mild flow-through biorefinery approach for grassy lignocellulosic biomass allows the production of various fractions: a fraction containing esterified aromatics, a monomeric xylose-rich stream, a glucose fraction, and a native-like lignin residue [2]. The crude xylose-rich fraction was free of fermentation-inhibiting compounds meaning that the bacterium S.thermodepolymerans could effectively use it for the production of one type of PHA, polyhydroxybutyrate. Almost 90% of the xylose in the refined wheat straw fraction was metabolized with simultaneous production of PHA, matching 90% of the PHA production per gram of sugars, comparable to PHA yields from commercially available xylose. In addition to xylose, S. thermodepolymerans converted oligosaccharides with a xylose backbone (xylans) into fermentable xylose, and subsequently utilized the xylose as a source for PHA production. Since the xylose-rich hydrolysates from the ALACEN process also contain some oligomeric xylose and minor hemicellulose-derived sugars, optimal valorization of the C5-fractions derived from the refinery process can be obtained using S. thermodepolymerans. This opens the way for further exploration of PHA production from C5-fractions out of a variety of herbaceous lignocellulosic biomasses using the ALACEN process combined with S. thermodepolymerans. Overall, the innovative utilization of renewable resources in fermentation technology, as shown herein, makes a solid contribution to the transition to a biobased economy.[1] W. Zhou, D.I. Colpa, H. Permentier, R.A. Offringa, L. Rohrbach, G.J.W. Euverink, J. Krooneman. Insight into polyhydroxyalkanoate (PHA) production from xylose and extracellular PHA degradation by a thermophilic Schlegelella thermodepolymerans. Resources, Conservation and Recycling 194 (2023) 107006, ISSN 0921-3449, https://doi.org/10.1016/j.resconrec.2023.107006. [2] S. Bertran-Llorens, W.Zhou. M.A.Palazzo, D.I.Colpa, G.J.W.Euverink, J.Krooneman, P.J.Deuss. ALACEN: a holistic herbaceous biomass fractionation process attaining a xylose-rich stream for direct microbial conversion to bioplastics. Submitted 2023.
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Although Pedagogical Content Knowledge (PCK) is traditionally defined as a static quality that teachers possess and apply in practice, we conceive of PCK as constituted by a dynamic, mutually influencing process between teacher and students. This co-constructing process is expressed in real-time interaction and defined by us as Expressed Pedagogical Content Knowledge (EPCK). The aim of this study is to develop a practically usable instrument that can track the microgenetic moment-to-moment interaction that embodies EPCK, and that enables us to observe different features and levels of EPCK in the form of changes in this interaction dynamics. We were interested to know how EPCK emerges and develops on the short-term time scale of classroom interaction. After presenting a general account of complex dynamic systems based measurement of psychological constructs (e.g., PCK), we describe a coding scheme for teacher-student interactions, based on theoretical EPCK components. The instrument was applied in an empirical observation study of a visit to a mobile planetarium by a grade 3 primary school class. A principal factor analysis was used to find latent EPCK components. Results show, firstly, that the instrument was reliable. Secondly, the variables in the coding scheme were relevant in view of the underlying theory. Thirdly, over the time course of the teaching session, latent components displayed various levels of EPCK – high, low or no ECPK. Instead of being an enduring or stable property of teaching-learning interactions, EPCK is a dynamic property occurring in the form of sequences of high and low levels, and corresponding peaks in the latent factors. Notably, EPCK did not appear in the form of a continuous steady state level but occurred in the form of bursts of high-level EPCK. We conclude that our coding scheme provides an adequate method for studying pedagogical content knowledge as it self-organizes in the form of real-time activity in the classroom.
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