TY - JOUR A1 - Lohse, Karoline A1 - Hildebrandt, Andrea A1 - Hildebrandt, Frauke T1 - Hypotheses in adult-child interactions stimulate children's reasoning and verbalizations JF - Early childhood research quarterly N2 - Adult-child interactions can support children's development and are established as predictors of program quality in early childhood settings. However, the linguistic components that constitute positive interactions have not yet been studied in detail. This study investigates the effects of hypotheses proposed by adults on children's responses in a dyadic picture-book viewing situation. In 2 experiments, adults' use of hypotheses (e.g., "Maybe this is a dwarf's door") was tested against the use of instructive statements ("This is a dwarf's door") and in combination with open questions ("What do you think, why is the door so small?"). In Experiment 1, hypotheses differed from instructions only by the modal marker "maybe". Children's responses to hypotheses were longer and contained more self-generated explanations as compared to responses to instructions. The use of hypotheses also seemed to encourage children to attach more importance to their own explanations. In Experiment 2, combining hypotheses with open-ended why questions elicited longer responses but no more self-generated explanations in children than openended questions alone. Results indicate that subtle differences in adults' utterances can directly influence children's reasoning and children's contributions to dialogues. KW - adult-child interactions KW - sustained shared thinking KW - hypotheses KW - open KW - questions Y1 - 2021 U6 - https://doi.org/10.1016/j.ecresq.2021.09.014 SN - 0885-2006 VL - 58 SP - 254 EP - 263 PB - Elsevier CY - New York ER - TY - JOUR A1 - Laun, Konstantin A1 - Duffus, Benjamin R. A1 - Wahlefeld, Stefan A1 - Katz, Sagie A1 - Belger, Dennis Heinz A1 - Hildebrandt, Peter A1 - Mroginski, Maria Andrea A1 - Leimkühler, Silke A1 - Zebger, Ingo T1 - Infrared spectroscopy flucidates the inhibitor binding sites in a metal-dependent formate dehydrogenase JF - Chemistry - a European journal N2 - Biological carbon dioxide (CO2) reduction is an important step by which organisms form valuable energy-richer molecules required for further metabolic processes. The Mo-dependent formate dehydrogenase (FDH) from Rhodobacter capsulatus catalyzes reversible formate oxidation to CO2 at a bis-molybdopterin guanine dinucleotide (bis-MGD) cofactor. To elucidate potential substrate binding sites relevant for the mechanism, we studied herein the interaction with the inhibitory molecules azide and cyanate, which are isoelectronic to CO2 and charged as formate. We employed infrared (IR) spectroscopy in combination with density functional theory (DFT) and inhibition kinetics. One distinct inhibitory molecule was found to bind to either a non-competitive or a competitive binding site in the secondary coordination sphere of the active site. Site-directed mutagenesis of key amino acid residues in the vicinity of the bis-MGD cofactor revealed changes in both non-competitive and competitive binding, whereby the inhibitor is in case of the latter interaction presumably bound between the cofactor and the adjacent Arg587. KW - CO2 reduction KW - DFT KW - formate oxidation KW - inhibition kinetics KW - IR KW - spectroscopy KW - molybdoenzyme Y1 - 2022 U6 - https://doi.org/10.1002/chem.202201091 SN - 0947-6539 SN - 1521-3765 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Carminati, Andrea A1 - Schneider, Christoph L. A1 - Moradi, Ahmad B. A1 - Zarebanadkouki, Mohsen A1 - Vetterlein, Doris A1 - Vogel, Hans-Jörg A1 - Hildebrandt, Anke A1 - Weller, Ulrich A1 - Schüler, Lennart A1 - Oswald, Sascha T1 - How the rhizosphere may favor water availability to roots JF - Vadose zone journal N2 - Recent studies have shown that rhizosphere hydraulic properties may differ from those of the bulk soil. Specifically, mucilage at the root-soil interface may increase the rhizosphere water holding capacity and hydraulic conductivity during drying. The goal of this study was to point out the implications of such altered rhizosphere hydraulic properties for soil-plant water relations. We addressed this problem through modeling based on a steady-rate approach. We calculated the water flow toward a single root assuming that the rhizosphere and bulk soil were two concentric cylinders having different hydraulic properties. Based on our previous experimental results, we assumed that the rhizosphere had higher water holding capacity and unsaturated conductivity than the bulk soil. The results showed that the water potential gradients in the rhizosphere were much smaller than in the bulk soil. The consequence is that the rhizosphere attenuated and delayed the drop in water potential in the vicinity of the root surface when the soil dried. This led to increased water availability to plants, as well as to higher effective conductivity under unsaturated conditions. The reasons were two: (i) thanks to the high unsaturated conductivity of the rhizosphere, the radius of water uptake was extended from the root to the rhizosphere surface; and (ii) thanks to the high soil water capacity of the rhizosphere, the water depletion in the bulk soil was compensated by water depletion in the rhizosphere. We conclude that under the assumed conditions, the rhizosphere works as an optimal hydraulic conductor and as a reservoir of water that can be taken up when water in the bulk soil becomes limiting. Y1 - 2011 U6 - https://doi.org/10.2136/vzj2010.0113 SN - 1539-1663 VL - 10 IS - 3 SP - 988 EP - 998 PB - Soil Science Society of America CY - Madison ER -