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DPH1 Gene Mutations Identify a Candidate SAM Pocket in Radical Enzyme Dph1 Dph2 for Diphthamide Synthesis on EF2
(2023-11-16)
In eukaryotes, the Dph1•Dph2 dimer is a non-canonical radical SAM enzyme. Using iron-sulfur (FeS) clusters, it cleaves the cosubstrate S-adenosyl-methionine (SAM) to form a 3-amino-3-carboxy-propyl (ACP) radical for the synthesis of diphthamide. The latter decorates a histidine residue on elongation factor 2 (EF2) conserved from archaea to yeast and humans and is important for accurate mRNA translation and protein synthesis. Guided by evidence from archaeal orthologues, we searched for a putative SAM-binding pocket ...
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Telecoupled urban demand from West African cities causes social-ecological land use transformation in Saharan oases
(2023-09-08)
Little is known about the long-distance telecoupling effects of urban food demands on land use changes (LUCs) in remote oases of the Southern Sahara. Using the example of two typical oasis settlements on Mont Bagzam in the southern Ar Mountains of Niger which are linked to regional and global markets by an unpaved road since 2015, this study aimed at analyzing time trajectories of LUCs and related changing agricultural production patterns. LUCs were quantified for 1955 to 2022 using GIS-based mapping of agriculture ...
Aufsatz
Domain Imaging in Periodic Submicron Wide Nanostructures by Digital Drift Correction in Kerr Microscopy
(2023-08-27)
Magneto-optical Kerr microscopy is a powerful method for imaging magnetic domains. Even though domain imaging below the diffractive resolution limit is possible, such investigations are getting increasingly complex with decreasing structure size due to the decreasing Kerr contrast. As magnetic domain images free of topographical artifacts are obtained by subtracting a reference image from the actual image, the corresponding challenges are additionally increased by unavoidable sample motion in the time interval between ...
Aufsatz
Benzene Oxidation over Pt Loaded on Fly Ash Zeolite X
(2023-07-20)
In the present study, zeolite X (FANaX) was synthesized from coal fly ash (FA) by a two-step high-temperature method. In order to follow the effect of different contaminants in the starting coal ash, zeolite X was also synthesized from pure chemicals according to a classical recipe (NaX). Iron was loaded on this reference zeolite with the amount which was contained in the coal FA. The final catalytic samples were obtained by wet impregnation of Pt nanoparticles on both types of zeolite crystals. The most active samples ...
Aufsatz
Free to See the Big Picture: Autonomy Increases Abstractness of Action Identification
(2023-10-10)
People sometimes feel autonomous—free to choose and able to control their actions; at other times, they feel restricted in what they can do and what the outcome will be. Based on Action Identification Theory, the present work examines whether autonomy influences how abstractly actions are represented. In 6 studies, high (vs. low) autonomy increased abstractness of action identification. Participants selected more abstract (vs. concrete) redescriptions of actions when they imagined wanting (vs. having) to perform these ...
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Yeast gene KTI13 (alias DPH8) operates in the initiation step of diphthamide synthesis on elongation factor 2
(2023-08-08)
In yeast, Elongator-dependent tRNA modifications are regulated by the Kti11•Kti13 dimer and hijacked for cell killing by zymocin, a tRNase ribotoxin. Kti11 (alias Dph3) also controls modification of elongation factor 2 (EF2) with diphthamide, the target for lethal ADP-ribosylation by diphtheria toxin (DT). Diphthamide formation on EF2 involves four biosynthetic steps encoded by the DPH1-DPH7 network and an ill-defined KTI13 function. On further examining the latter gene in yeast, we found that kti13Δ null-mutants ...
Aufsatz
Fostering diagnostic competence in prospective mathematics elementary teachers through epistemic activities
(2023-12-21)
Research on fostering teachers’ diagnostic competence and thinking has become increasingly important. To this end, research has already identified several aspects of effective fostering of teachers’ diagnostic competence. One of the aspects is assignment of the role as a teacher in interventions but, so far, assignment of the role of student has hardly been considered. Based on a model of the diagnostic thinking process, this paper operationalizes the role of the student by solving specific tasks and the role of the ...
Aufsatz
Is the perceptual disfluency effect moderated by working memory capacity? Direct replication of Lehmann et al. (2016)
(2023-12-30)
According to an aptitude-treatment interaction experiment (Lehmann et al., Metacognition and Learning, 11, 89–105, 2016, N = 47, published in Metacognition and Learning), perceptually disfluent texts facilitated retention and comprehension performance (but not transfer performance) only for learners with higher working memory capacity (WMC). No effects of WMC for a fluent text were found (albeit theoretically, fluency may be more advantageous for learners with lower WMC). The findings of our (pre-registered) direct ...
Aufsatz
Nitrogen fixation of lablab and finger millet in South-India
(2023-12-21)
Background
In a long-term rotation experiment (2016–2022) with different nitrogen (N) fertilizer levels in subtropical South-India, crop yields of low N plots were unexpectedly high. We therefore hypothesized that in the absence of mineral N application, these yields are largely due to N inputs by N₂ fixation in the component crops. To assess the diazotrophic N₂-fixation of lablab (Lablab purpureus L. Sweet) and possible associative N₂-fixation of finger millet (Eleusine coracana L. Gaertn), a controlled experiment ...
Aufsatz
On the Monotonic and Cyclic Behavior of an Al-Mg-Zn-Cu-Si Compositionally Complex Alloy
(2023-08-03)
In present work, the monotonic and cyclic properties of a novel Al-Mg-Zn-Cu-Si compositionally complex alloy (CCA) are investigated. Microstructural studies reveal that a eutectic phase and fishbone-type structures are embedded in the Al-matrix. The mechanical properties of this CCA obtained under compressive loading are found to be promising. However, low ultimate strength and brittle behavior are seen under tension. The fatigue performance of the alloy in the low-cycle fatigue (LCF) regime is poor. Microstructural ...