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  • Research Data
    α-RuCl3 intercalated into graphite: a new three-dimensional platform for exotic quantum phases
    Multilayer graphene with different stacking sequences has emerged as a powerful setting for correlated and topological phases. In parallel, progress in graphene heterostructures with magnetic or correlated materials—most notably the Kitaev candidate α-RuCl3 —has demonstrated charge transfer, magnetic proximity effects, and interfacial reconstruction, creating new opportunities for engineered quantum systems. Motivated by these developments, we explore a three-dimensional analogue in which α-RuCl3 layers are inserted directly into the van der Waals gaps of graphite, forming an intercalated system. Here, we report the successful synthesis and comprehensive characterization of graphite intercalated with α- RuCl3. Using a combination of X-ray diffraction, quantum oscillation measurements, and first-principles electronic structure calculations, we study the structural and electronic properties of this intercalated crystals. Our results demonstrate that graphite intercalated with α-RuCl3 offers a robust route to develop three-dimensional materials with access to novel correlated and topological states.
      3  1
  • Research Data
    Many-body Euler topology
    2026-01-20
    Neupert, Titus
    Kopp, Thilo
    Valentí, Roser
    Code for calculations and data points for figures.
      4  2
  • Research Data
    Spatial confinement of T cell receptors is sufficient to initiate signaling
    2026-06-12
    Glück, David
    Leitner, Judith
    Nocker, Tobias
    Steinberger, Peter
    T cell receptor (TCR) activation is traditionally attributed to antigen recognition via peptide–MHC (pMHC) complexes. However, TCR signaling can occur independently of antigen engagement, raising questions about the physical triggers initiating activation. Here, we engineered fully functional TCR–CD3 complexes bearing an extracellular His-tag, enabling controlled nanoscale clustering without pMHC binding. Using antibody-mediated crosslinking, chemically retargeted antibodies, and spatially patterned surfaces, we demonstrate that enforced TCR clustering is sufficient to trigger early signaling events, including ZAP-70 phosphorylation, CD45 phosphatase exclusion, and NF-κB activation. Notably, signaling output exhibits a threshold-like behavior rather than correlating with receptor density. These findings demonstrate that nanoscale receptor confinement is sufficient to initiate proximal T cell signaling in the absence of pMHC engagement. This work experimentally separates receptor spatial organization from antigen recognition and provides a framework to understand antigen-independent and tonic signaling in adaptive immunity.
      40  2
  • Research Data
    AI-based Monitoring of European Hamster Activity
    2026-02-03
    Dierkes, Paul W.
    Wittekind, Marie
    In order to ensure the effective conservation of the critically endangered European hamster (Cricetus cricetus), there is a necessity for the implementation of targeted conservation measures and reliable monitoring methods. This study explores the potential of employing artificial intelligence (AI) to assist with camera trap monitoring for the purpose of tracking hamster activity. To this end, a deep learning object detection model (YOLO) was trained to efficiently analyze large volumes of video data from summer 2023 with high reliability. The model achieved a weighted average F1-score of 0.93 and an accuracy of 0.93 for the detection of European hamsters, effectively differentiating them from other species. A comparison between AI-based and human evaluations confirmed that AI can reliably depict hamster activity patterns. The findings of this study suggest that European hamsters exhibit peak activity levels at dusk, with the highest peak in activity occurring around sunset. In contrast, activity levels were lowest around midday. Autocorrelation analysis revealed a biphasic activity pattern, with a secondary peak occurring approximately before sunrise. This study underscores the potential of employing artificial intelligence for long-term conservation efforts and its applicability in assessing the success of reintroduction programs.
      6  15
  • Research Data
    TEI/XML encoded transcription Na_50-412 from the Arthur Schopenhauer Legacy
    This document is a TEI/XML encoded transcription of the document Na_50-412 from the Arthur Schopenhauer Legacy - 'Schopenhauer-Archive': "Selbstverfasstes Gedicht "Was wäre wünschenswerter wohl als ganz zu siegen über das leere und so arme Leben?"" from Arthur Schopenhauer. Transcribed by Marcus Koch, TEI encoded by Hannah Völker (https://sammlungen.ub.uni-frankfurt.de/schopenhauer/content/titleinfo/4235145)
      9
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  • Research Data
    The global water resources and use model WaterGAP v2.2e - model output driven by gswp3-w5e5 and historical setup of direct human impacts
    2023-10-20
    Trautmann, Tim
    Ackermann, Sebastian
    Cáceres, Denise
    Flörke, Martina
    Gerdener, Helena
    Kynast, Ellen
    Peiris, Thedini Asali
    Schiebener, Leonie
    Schumacher, Maike
    Assessing global freshwater resources and human water use is of value for a number of needs but challenging. The global water use and water availability model WaterGAP has been in development since 1996 and has served a range of applications such as assessments of global water resources and water stress, also under the impact of climate change, drought hazard quantification, Life Cycle Assessments, water (over)use and consequently depletion of water resources and a better understanding of terrestrial water storage variations (jointly with satellite observations). Here, the reader can download model output for the time period 1901-2019 that was computed by driving WaterGAP v2.2e by four alternative climate datasets (climate forcings) that were generated in the ISIMIP context (https://www.isimip.org) and are described in https://data.isimip.org/10.48364/ISIMIP.982724. For two climate datasets, model runs up to 2021 or 2022 are available. For comparison, output of a version of WaterGAP v2.2d that is calibrated to the same dataset of observed streamflow as WaterGAP v2.2e is provided. Each of the climate forcing-model version combinations is run in two socio-economic settings, histsoc and nosoc. In nosoc, human water use is set to zero and man-made reservoirs are assumed to be non-existant. In the paper connected to this dataset (to be submitted to Geoscientific Model Development), the newest model version, WaterGAP v2.2e is described by providing the modifications to the previous version v2.2d (Müller Schmied et al. 2021) and the corresponding changes in model output. The most important and requested model outputs (total water storage variations, streamflow and water use) are evaluated against observation data. Standard model output is described as well as the specifics of the WaterGAP contribution within the ISIMIP framework. Müller Schmied, H., Cáceres, D., Eisner, S., Flörke, M., Herbert, C., Niemann, C., Peiris, T. A., Popat, E., Portmann, F. T., Reinecke, R., Schumacher, M., Shadkam, S., Telteu, C.-E., Trautmann, T., Döll, P. (2021): The global water resources and use model WaterGAP v2.2d: Model description and evaluation. Geosci. Model Dev., 14, 1037–1079. https://doi.org/10.5194/gmd-14-1037-2021
      1582  1065
  • Research Data
    The global water resources and use model WaterGAP v2.2e - model output driven by gswp3-era5 and historical setup of direct human impacts
    2023-10-20
    Trautmann, Tim
    Ackermann, Sebastian
    Cáceres, Denise
    Flörke, Martina
    Gerdener, Helena
    Kynast, Ellen
    Peiris, Thedini Asali
    Schiebener, Leonie
    Schumacher, Maike
    Assessing global freshwater resources and human water use is of value for a number of needs but challenging. The global water use and water availability model WaterGAP has been in development since 1996 and has served a range of applications such as assessments of global water resources and water stress, also under the impact of climate change, drought hazard quantification, Life Cycle Assessments, water (over)use and consequently depletion of water resources and a better understanding of terrestrial water storage variations (jointly with satellite observations). Here, the reader can download model output for the time period 1901-2019 that was computed by driving WaterGAP v2.2e by four alternative climate datasets (climate forcings) that were generated in the ISIMIP context (https://www.isimip.org) and are described in https://data.isimip.org/10.48364/ISIMIP.982724. For two climate datasets, model runs up to 2021 or 2023 are available. For comparison, output of a version of WaterGAP v2.2d that is calibrated to the same dataset of observed streamflow as WaterGAP v2.2e is provided. Each of the climate forcing-model version combinations is run in two socio-economic settings, histsoc and nosoc. In nosoc, human water use is set to zero and man-made reservoirs are assumed to be non-existant. In the paper connected to this dataset (in review with Geoscientific Model Development), the newest model version, WaterGAP v2.2e is described by providing the modifications to the previous version v2.2d (Müller Schmied et al. 2021) and the corresponding changes in model output. The most important and requested model outputs (total water storage variations, streamflow and water use) are evaluated against observation data. Standard model output is described as well as the specifics of the WaterGAP contribution within the ISIMIP framework. Müller Schmied, H., Cáceres, D., Eisner, S., Flörke, M., Herbert, C., Niemann, C., Peiris, T. A., Popat, E., Portmann, F. T., Reinecke, R., Schumacher, M., Shadkam, S., Telteu, C.-E., Trautmann, T., Döll, P. (2021): The global water resources and use model WaterGAP v2.2d: Model description and evaluation. Geosci. Model Dev., 14, 1037–1079. https://doi.org/10.5194/gmd-14-1037-2021
      973  997
  • Research Data
    The global water resources and use model WaterGAP v2.2e - daily water storage model output driven by gswp3-w5e5 and historical setup of direct human impacts
    2024-04-04
    Trautmann, Tim
    Ackermann, Sebastian
    Cáceres, Denise
    Flörke, Martina
    Gerdener, Helena
    Kynast, Ellen
    Peiris, Thedini Asali
    Schiebener, Leonie
    Schumacher, Maike
    Assessing global freshwater resources and human water use is of value for a number of needs but challenging. The global water use and water availability model WaterGAP has been in development since 1996 and has served a range of applications such as assessments of global water resources and water stress, also under the impact of climate change, drought hazard quantification, Life Cycle Assessments, water (over)use and consequently depletion of water resources and a better understanding of terrestrial water storage variations (jointly with satellite observations). Here, the reader can download daily model output for water storage variables for the time period 1901-2019 (2023) that was computed by driving WaterGAP v2.2e by two alternative climate datasets (climate forcings) that were generated in the ISIMIP context (https://www.isimip.org) and are described in https://data.isimip.org/10.48364/ISIMIP.982724. In the paper connected to this dataset (in review with Geoscientific Model Development), the newest model version, WaterGAP v2.2e is described by providing the modifications to the previous version v2.2d (Müller Schmied et al. 2021) and the corresponding changes in model output. Here, the single water storage compartments and terrestrial (total) water storage are provided.
      461  238
  • Research Data
    The global water resources and use model WaterGAP v2.2e - daily water storage model output driven by gswp3-era5 and historical setup of direct human impacts
    2024-04-04
    Trautmann, Tim
    Ackermann, Sebastian
    Cáceres, Denise
    Flörke, Martina
    Gerdener, Helena
    Kynast, Ellen
    Peiris, Thedini Asali
    Schiebener, Leonie
    Schumacher, Maike
    Assessing global freshwater resources and human water use is of value for a number of needs but challenging. The global water use and water availability model WaterGAP has been in development since 1996 and has served a range of applications such as assessments of global water resources and water stress, also under the impact of climate change, drought hazard quantification, Life Cycle Assessments, water (over)use and consequently depletion of water resources and a better understanding of terrestrial water storage variations (jointly with satellite observations). Here, the reader can download daily model output for water storage variables for the time period 1901-2019 (2023) that was computed by driving WaterGAP v2.2e by two alternative climate datasets (climate forcings) that were generated in the ISIMIP context (https://www.isimip.org) and are described in https://data.isimip.org/10.48364/ISIMIP.982724. In the paper connected to this dataset (in review with Geoscientific Model Development), the newest model version, WaterGAP v2.2e is described by providing the modifications to the previous version v2.2d (Müller Schmied et al. 2021) and the corresponding changes in model output. Here, the single water storage compartments and terrestrial (total) water storage are provided.
      445  333
  • Research Data
    A j_eff 12 Kitaev material on the triangular lattice: The case of NaRuO2
    Motivated by recent reports of a quantum disordered ground state in the triangular lattice compound NaRuO$_2$, we derive a $j_{\rm eff}=1/2$ magnetic model for this system by means of first-principles calculations. The pseudospin Hamiltonian is dominated by bond-dependent off-diagonal $\Gamma$ interactions, complemented by a ferromagnetic Heisenberg exchange and a notably \emph{antiferromagnetic} Kitaev term. In addition to bilinear interactions, we find a sizable four-spin ring exchange contribution with a \emph{strongly anisotropic} character, which has been so far overlooked when modeling Kitaev materials. The analysis of the magnetic model, based on the minimization of the classical energy and exact diagonalization of the quantum Hamiltonian, points toward the existence of a rather robust easy-plane ferromagnetic order, which cannot be easily destabilized by physically relevant perturbations.
      376  40