TY - JOUR
A1 - Reese, Ronja
A1 - Winkelmann, Ricarda
A1 - Gudmundsson, Gudmundur Hilmar
T1 - Grounding-line flux formula applied as a flux condition in numerical simulations fails for buttressed Antarctic ice streams
JF - The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union
N2 - Currently, several large-scale ice-flow models impose a condition on ice flux across grounding lines using an analytically motivated parameterisation of grounding-line flux. It has been suggested that employing this analytical expression alleviates the need for highly resolved computational domains around grounding lines of marine ice sheets. While the analytical flux formula is expected to be accurate in an unbuttressed flow-line setting, its validity has hitherto not been assessed for complex and realistic geometries such as those of the Antarctic Ice Sheet. Here the accuracy of this analytical flux formula is tested against an optimised ice flow model that uses a highly resolved computational mesh around the Antarctic grounding lines. We find that when applied to the Antarctic Ice Sheet the analytical expression provides inaccurate estimates of ice fluxes for almost all grounding lines. Furthermore, in many instances direct application of the analytical formula gives rise to unphysical complex-valued ice fluxes. We conclude that grounding lines of the Antarctic Ice Sheet are, in general, too highly buttressed for the analytical parameterisation to be of practical value for the calculation of grounding-line fluxes.
Y1 - 2018
U6 - https://doi.org/10.5194/tc-12-3229-2018
SN - 1994-0416
SN - 1994-0424
VL - 12
IS - 10
SP - 3229
EP - 3242
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Ciemer, Catrin
A1 - Rehm, Lars
A1 - Kurths, Jürgen
A1 - Donner, Reik Volker
A1 - Winkelmann, Ricarda
A1 - Boers, Niklas
T1 - An early-warning indicator for Amazon droughts exclusively based on tropical Atlantic sea surface temperatures
JF - Environmental Research Letters
N2 - Droughts in tropical South America have an imminent and severe impact on the Amazon rainforest and affect the livelihoods of millions of people. Extremely dry conditions in Amazonia have been previously linked to sea surface temperature (SST) anomalies in the adjacent tropical oceans. Although the sources and impacts of such droughts have been widely studied, establishing reliable multi-year lead statistical forecasts of their occurrence is still an ongoing challenge. Here, we further investigate the relationship between SST and rainfall anomalies using a complex network approach. We identify four ocean regions which exhibit the strongest overall SST correlations with central Amazon rainfall, including two particularly prominent regions in the northern and southern tropical Atlantic. Based on the time-dependent correlation between SST anomalies in these two regions alone, we establish a new early-warning method for droughts in the central Amazon basin and demonstrate its robustness in hindcasting past major drought events with lead-times up to 18 months.
KW - complex networks
KW - droughts
KW - prediction
KW - Amazon rainforest
Y1 - 2019
VL - 15
IS - 9
PB - IOP - Institute of Physics Publishing
CY - Bristol
ER -
TY - JOUR
A1 - Seroussi, Helene
A1 - Nowicki, Sophie
A1 - Payne, Antony J.
A1 - Goelzer, Heiko
A1 - Lipscomb, William H.
A1 - Abe-Ouchi, Ayako
A1 - Agosta, Cecile
A1 - Albrecht, Torsten
A1 - Asay-Davis, Xylar
A1 - Barthel, Alice
A1 - Calov, Reinhard
A1 - Cullather, Richard
A1 - Dumas, Christophe
A1 - Galton-Fenzi, Benjamin K.
A1 - Gladstone, Rupert
A1 - Golledge, Nicholas R.
A1 - Gregory, Jonathan M.
A1 - Greve, Ralf
A1 - Hattermann, Tore
A1 - Hoffman, Matthew J.
A1 - Humbert, Angelika
A1 - Huybrechts, Philippe
A1 - Jourdain, Nicolas C.
A1 - Kleiner, Thomas
A1 - Larour, Eric
A1 - Leguy, Gunter R.
A1 - Lowry, Daniel P.
A1 - Little, Chistopher M.
A1 - Morlighem, Mathieu
A1 - Pattyn, Frank
A1 - Pelle, Tyler
A1 - Price, Stephen F.
A1 - Quiquet, Aurelien
A1 - Reese, Ronja
A1 - Schlegel, Nicole-Jeanne
A1 - Shepherd, Andrew
A1 - Simon, Erika
A1 - Smith, Robin S.
A1 - Straneo, Fiammetta
A1 - Sun, Sainan
A1 - Trusel, Luke D.
A1 - Van Breedam, Jonas
A1 - van de Wal, Roderik S. W.
A1 - Winkelmann, Ricarda
A1 - Zhao, Chen
A1 - Zhang, Tong
A1 - Zwinger, Thomas
T1 - ISMIP6 Antarctica
BT - a multi-model ensemble of the Antarctic ice sheet evolution over the 21st century
JF - The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union
N2 - Ice flow models of the Antarctic ice sheet are commonly used to simulate its future evolution in response to different climate scenarios and assess the mass loss that would contribute to future sea level rise. However, there is currently no consensus on estimates of the future mass balance of the ice sheet, primarily because of differences in the representation of physical processes, forcings employed and initial states of ice sheet models. This study presents results from ice flow model simulations from 13 international groups focusing on the evolution of the Antarctic ice sheet during the period 2015-2100 as part of the Ice Sheet Model Intercomparison for CMIP6 (ISMIP6). They are forced with outputs from a subset of models from the Coupled Model Intercomparison Project Phase 5 (CMIP5), representative of the spread in climate model results. Simulations of the Antarctic ice sheet contribution to sea level rise in response to increased warming during this period varies between 7:8 and 30.0 cm of sea level equivalent (SLE) under Representative Concentration Pathway (RCP) 8.5 scenario forcing. These numbers are relative to a control experiment with constant climate conditions and should therefore be added to the mass loss contribution under climate conditions similar to present-day conditions over the same period. The simulated evolution of the West Antarctic ice sheet varies widely among models, with an overall mass loss, up to 18.0 cm SLE, in response to changes in oceanic conditions. East Antarctica mass change varies between 6 :1 and 8.3 cm SLE in the simulations, with a significant increase in surface mass balance outweighing the increased ice discharge under most RCP 8.5 scenario forcings. The inclusion of ice shelf collapse, here assumed to be caused by large amounts of liquid water ponding at the surface of ice shelves, yields an additional simulated mass loss of 28mm compared to simulations without ice shelf collapse. The largest sources of uncertainty come from the climate forcing, the ocean-induced melt rates, the calibration of these melt rates based on oceanic conditions taken outside of ice shelf cavities and the ice sheet dynamic response to these oceanic changes. Results under RCP 2.6 scenario based on two CMIP5 climate models show an additional mass loss of 0 and 3 cm of SLE on average compared to simulations done under present-day conditions for the two CMIP5 forcings used and display limited mass gain in East Antarctica.
Y1 - 2020
U6 - https://doi.org/10.5194/tc-14-3033-2020
SN - 1994-0416
SN - 1994-0424
VL - 14
IS - 9
SP - 3033
EP - 3070
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Reese, Ronja
A1 - Levermann, Anders
A1 - Albrecht, Torsten
A1 - Seroussi, Helene
A1 - Winkelmann, Ricarda
T1 - The role of history and strength of the oceanic forcing in sea level projections from Antarctica with the Parallel Ice Sheet Model
JF - The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union
N2 - Mass loss from the Antarctic Ice Sheet constitutes the largest uncertainty in projections of future sea level rise. Ocean-driven melting underneath the floating ice shelves and subsequent acceleration of the inland ice streams are the major reasons for currently observed mass loss from Antarctica and are expected to become more important in the future. Here we show that for projections of future mass loss from the Antarctic Ice Sheet, it is essential (1) to better constrain the sensitivity of sub-shelf melt rates to ocean warming and (2) to include the historic trajectory of the ice sheet. In particular, we find that while the ice sheet response in simulations using the Parallel Ice Sheet Model is comparable to the median response of models in three Antarctic Ice Sheet Intercomparison projects - initMIP, LARMIP-2 and ISMIP6 - conducted with a range of ice sheet models, the projected 21st century sea level contribution differs significantly depending on these two factors. For the highest emission scenario RCP8.5, this leads to projected ice loss ranging from 1:4 to 4:0 cm of sea level equivalent in simulations in which ISMIP6 ocean forcing drives the PICO ocean box model where parameter tuning leads to a comparably low sub-shelf melt sensitivity and in which no surface forcing is applied. This is opposed to a likely range of 9:1 to 35:8 cm using the exact same initial setup, but emulated from the LARMIP-2 experiments with a higher melt sensitivity, even though both projects use forcing from climate models and melt rates are calibrated with previous oceanographic studies. Furthermore, using two initial states, one with a previous historic simulation from 1850 to 2014 and one starting from a steady state, we show that while differences between the ice sheet configurations in 2015 seem marginal at first sight, the historic simulation increases the susceptibility of the ice sheet to ocean warming, thereby increasing mass loss from 2015 to 2100 by 5% to 50 %. Hindcasting past ice sheet changes with numerical models would thus provide valuable tools to better constrain projections. Our results emphasize that the uncertainty that arises from the forcing is of the same order of magnitude as the ice dynamic response for future sea level projections.
Y1 - 2020
U6 - https://doi.org/10.5194/tc-14-3097-2020
SN - 1994-0416
SN - 1994-0424
VL - 14
IS - 9
SP - 3097
EP - 3110
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Zeitz, Maria
A1 - Levermann, Anders
A1 - Winkelmann, Ricarda
T1 - Sensitivity of ice loss to uncertainty in flow law parameters in an idealized one-dimensional geometry
JF - The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union
N2 - Acceleration of the flow of ice drives mass losses in both the Antarctic and the Greenland Ice Sheet. The projections of possible future sea-level rise rely on numerical ice-sheet models, which solve the physics of ice flow, melt, and calving. While major advancements have been made by the ice-sheet modeling community in addressing several of the related uncertainties, the flow law, which is at the center of most process-based ice-sheet models, is not in the focus of the current scientific debate. However, recent studies show that the flow law parameters are highly uncertain and might be different from the widely accepted standard values. Here, we use an idealized flow-line setup to investigate how these uncertainties in the flow law translate into uncertainties in flow-driven mass loss. In order to disentangle the effect of future warming on the ice flow from other effects, we perform a suite of experiments with the Parallel Ice Sheet Model (PISM), deliberately excluding changes in the surface mass balance. We find that changes in the flow parameters within the observed range can lead up to a doubling of the flow-driven mass loss within the first centuries of warming, compared to standard parameters. The spread of ice loss due to the uncertainty in flow parameters is on the same order of magnitude as the increase in mass loss due to surface warming. While this study focuses on an idealized flow-line geometry, it is likely that this uncertainty carries over to realistic three-dimensional simulations of Greenland and Antarctica.
Y1 - 2020
U6 - https://doi.org/10.5194/tc-14-3537-2020
SN - 1994-0416
SN - 1994-0424
VL - 14
IS - 10
SP - 3537
EP - 3550
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Albrecht, Torsten
A1 - Winkelmann, Ricarda
A1 - Levermann, Anders
T1 - Glacial-cycle simulations of the Antarctic Ice Sheet with the Parallel Ice Sheet Model (PISM)
BT - Part 1: boundary conditions and climatic forcing
JF - The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union
N2 - Simulations of the glacial-interglacial history of the Antarctic Ice Sheet provide insights into dynamic threshold behavior and estimates of the ice sheet's contributions to global sea-level changes for the past, present and future. However, boundary conditions are weakly constrained, in particular at the interface of the ice sheet and the bedrock. Also climatic forcing covering the last glacial cycles is uncertain, as it is based on sparse proxy data.
We use the Parallel Ice Sheet Model (PISM) to investigate the dynamic effects of different choices of input data, e.g., for modern basal heat flux or reconstructions of past changes of sea level and surface temperature. As computational resources are limited, glacial-cycle simulations are performed using a comparably coarse model grid of 16 km and various parameterizations, e.g., for basal sliding, iceberg calving, or for past variations in precipitation and ocean temperatures. In this study we evaluate the model's transient sensitivity to corresponding parameter choices and to different boundary conditions over the last two glacial cycles and provide estimates of involved uncertainties. We also discuss isolated and combined effects of climate and sea-level forcing. Hence, this study serves as a "cookbook" for the growing community of PISM users and paleo-ice sheet modelers in general.
For each of the different model uncertainties with regard to climatic forcing, ice and Earth dynamics, and basal processes, we select one representative model parameter that captures relevant uncertainties and motivates corresponding parameter ranges that bound the observed ice volume at present. The four selected parameters are systematically varied in a parameter ensemble analysis, which is described in a companion paper.
Y1 - 2020
U6 - https://doi.org/10.5194/tc-14-599-2020
SN - 1994-0416
SN - 1994-0424
VL - 14
IS - 2
SP - 599
EP - 632
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Kreuzer, Moritz
A1 - Reese, Ronja
A1 - Huiskamp, Willem Nicholas
A1 - Petri, Stefan
A1 - Albrecht, Torsten
A1 - Feulner, Georg
A1 - Winkelmann, Ricarda
T1 - Coupling framework (1.0) for the PISM (1.1.4) ice sheet model and the MOMS (5.1.0) ocean model via the PICO ice shelf cavity model in an Antarctic domain
JF - Geoscientific model development : an interactive open access journal of the European Geosciences Union
N2 - The past and future evolution of the Antarctic Ice Sheet is largely controlled by interactions between the ocean and floating ice shelves. To investigate these interactions, coupled ocean and ice sheet model configurations are required. Previous modelling studies have mostly relied on high-resolution configurations, limiting these studies to individual glaciers or regions over short timescales of decades to a few centuries. We present a framework to couple the dynamic ice sheet model PISM (Parallel Ice Sheet Model) with the global ocean general circulation model MOM5 (Modular Ocean Model) via the ice shelf cavity model PICO (Pots-dam Ice-shelf Cavity mOdel). As ice shelf cavities are not resolved by MOM5 but are parameterized with the PICO box model, the framework allows the ice sheet and ocean components to be run at resolutions of 16 km and 3 degrees respectively. This approach makes the coupled configuration a useful tool for the analysis of interactions between the Antarctic Ice Sheet and the global ocean over time spans of the order of centuries to millennia. In this study, we describe the technical implementation of this coupling framework: sub-shelf melting in the ice sheet component is calculated by PICO from modelled ocean temperatures and salinities at the depth of the continental shelf, and, vice versa, the resulting mass and energy fluxes from melting at the ice-ocean interface are transferred to the ocean component. Mass and energy fluxes are shown to be conserved to machine precision across the considered component domains. The implementation is computationally efficient as it introduces only minimal overhead. Furthermore, the coupled model is evaluated in a 4000 year simulation under constant present-day climate forcing and is found to be stable with respect to the ocean and ice sheet spin-up states. The framework deals with heterogeneous spatial grid geometries, varying grid resolutions, and timescales between the ice and ocean component in a generic way; thus, it can be adopted to a wide range of model set-ups.
Y1 - 2021
U6 - https://doi.org/10.5194/gmd-14-3697-2021
SN - 1991-959X
SN - 1991-9603
VL - 14
IS - 6
SP - 3697
EP - 3714
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Zeitz, Maria
A1 - Haacker, Jan M.
A1 - Donges, Jonathan
A1 - Albrecht, Torsten
A1 - Winkelmann, Ricarda
T1 - Dynamic regimes of the Greenland Ice Sheet emerging from interacting melt-elevation and glacial isostatic adjustment feedbacks
JF - Earth system dynamics
N2 - The stability of the Greenland Ice Sheet under global warming is governed by a number of dynamic processes and interacting feedback mechanisms in the ice sheet, atmosphere and solid Earth.
Here we study the long-term effects due to the interplay of the competing melt-elevation and glacial isostatic adjustment (GIA) feedbacks for different temperature step forcing experiments with a coupled ice-sheet and solid-Earth model.
Our model results show that for warming levels above 2 degrees C, Greenland could become essentially ice-free within several millennia, mainly as a result of surface melting and acceleration of ice flow. These ice losses are mitigated, however, in some cases with strong GIA feedback even promoting an incomplete recovery of the Greenland ice volume. We further explore the full-factorial parameter space determining the relative strengths of the two feedbacks: our findings suggest distinct dynamic regimes of the Greenland Ice Sheets on the route to destabilization under global warming - from incomplete recovery, via quasi-periodic oscillations in ice volume to ice-sheet collapse.
In the incomplete recovery regime, the initial ice loss due to warming is essentially reversed within 50 000 years, and the ice volume stabilizes at 61 %-93 % of the present-day volume. For certain combinations of temperature increase, atmospheric lapse rate and mantle viscosity, the interaction of the GIA feedback and the melt-elevation feedback leads to self-sustained, long-term oscillations in ice-sheet volume with oscillation periods between 74 000 and over 300 000 years and oscillation amplitudes between 15 %-70 % of present-day ice volume.
This oscillatory regime reveals a possible mode of internal climatic variability in the Earth system on timescales on the order of 100 000 years that may be excited by or synchronized with orbital forcing or interact with glacial cycles and other slow modes of variability. Our findings are not meant as scenario-based near-term projections of ice losses but rather providing insight into of the feedback loops governing the "deep future" and, thus, long-term resilience of the Greenland Ice Sheet.
Y1 - 2022
U6 - https://doi.org/10.5194/esd-13-1077-2022
SN - 2190-4979
SN - 2190-4987
VL - 13
IS - 3
SP - 1077
EP - 1096
PB - Copernicus Publ.
CY - Göttingen
ER -
TY - JOUR
A1 - Albrecht, Torsten
A1 - Winkelmann, Ricarda
A1 - Levermann, Anders
T1 - Glacial-cycle simulations of the Antarctic Ice Sheet with the Parallel Ice Sheet Model (PISM)
BT - part 2: parameter ensemble analysis
JF - The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union
N2 - The Parallel Ice Sheet Model (PISM) is applied to the Antarctic Ice Sheet over the last two glacial cycles (approximate to 210 000 years) with a resolution of 16 km. An ensemble of 256 model runs is analyzed in which four relevant model parameters have been systematically varied using full-factorial parameter sampling. Parameters and plausible parameter ranges have been identified in a companion paper (Albrecht et al., 2020) and are associated with ice dynamics, climatic forcing, basal sliding and bed deformation and represent distinct classes of model uncertainties. The model is scored against both modern and geologic data, including reconstructed grounding-line locations, elevation-age data, ice thickness, surface velocities and uplift rates. An aggregated score is computed for each ensemble member that measures the overall model-data misfit, including measurement uncertainty in terms of a Gaussian error model (Briggs and Tarasov, 2013). The statistical method used to analyze the ensemble simulation results follows closely the simple averaging method described in Pollard et al. (2016).
This analysis reveals clusters of best-fit parameter combinations, and hence a likely range of relevant model and boundary parameters, rather than individual best-fit parameters. The ensemble of reconstructed histories of Antarctic Ice Sheet volumes provides a score-weighted likely range of sea-level contributions since the Last Glacial Maximum (LGM) of 9.4 +/- 4.1m (or 6.5 +/- 2.0 x 10(6) km(3)), which is at the upper range of most previous studies. The last deglaciation occurs in all ensemble simulations after around 12 000 years before present and hence after the meltwater pulse 1A (MWP1a). Our ensemble analysis also provides an estimate of parametric uncertainty bounds for the present-day state that can be used for PISM projections of future sea-level contributions from the Antarctic Ice Sheet.
Y1 - 2020
U6 - https://doi.org/10.5194/tc-14-633-2020
SN - 1994-0416
SN - 1994-0424
VL - 14
IS - 2
SP - 633
EP - 656
PB - Copernicus Publ.
CY - Göttingen
ER -
TY - JOUR
A1 - Schlemm, Tanja
A1 - Feldmann, Johannes
A1 - Winkelmann, Ricarda
A1 - Levermann, Anders
T1 - Stabilizing effect of melange buttressing on the marine ice-cliff instability of the West Antarctic Ice Sheet
JF - The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union
N2 - Owing to global warming and particularly high regional ocean warming, both Thwaites and Pine Island Glaciers in the Amundsen region of the Antarctic Ice Sheet could lose their buttressing ice shelves over time. We analyse the possible consequences using the parallel ice sheet model (PISM), applying a simple cliff-calving parameterization and an ice melange-buttressing model. We find that the instantaneous loss of ice-shelf buttressing, due to enforced ice-shelf melting, initiates grounding-line retreat and triggers marine ice sheet instability (MISI). As a consequence, the grounding line progresses into the interior of the West Antarctic Ice Sheet and leads to a sea level contribution of 0.6 m within 100 a. By subjecting the exposed ice cliffs to cliff calving using our simplified parameterization, we also analyse marine ice cliff instability (MICI). In our simulations it can double or even triple the sea level contribution depending on the only loosely constrained parameter that determines the maximum cliff-calving rate. The speed of MICI depends on this upper bound of the calving rate, which is given by the ice melange buttressing the glacier. However, stabilization of MICI may occur for geometric reasons. Because the embayment geometry changes as MICI advances into the interior of the ice sheet, the upper bound on calving rates is reduced and the progress of MICI is slowed down. Although we cannot claim that our simulations bear relevant quantitative estimates of the effect of ice-melange buttressing on MICI, the mechanism has the potential to stop the instability. Further research is needed to evaluate its role for the past and future evolution of the Antarctic Ice Sheet.
Y1 - 2022
U6 - https://doi.org/10.5194/tc-16-1979-2022
SN - 1994-0416
SN - 1994-0424
VL - 16
IS - 5
SP - 1979
EP - 1996
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Feldmann, Johannes
A1 - Reese, Ronja
A1 - Winkelmann, Ricarda
A1 - Levermann, Anders
T1 - Shear-margin melting causes stronger transient ice discharge than ice-stream melting in idealized simulations
JF - The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union
N2 - Basal ice-shelf melting is the key driver of Antarctica's increasing sea-level contribution. In diminishing the buttressing force of the ice shelves that fringe the ice sheet, the melting increases the ice discharge into the ocean.
Here we contrast the influence of basal melting in two different ice-shelf regions on the time-dependent response of an isothermal, inherently buttressed ice-sheet-shelf system. In the idealized numerical simulations, the basal-melt perturbations are applied close to the grounding line in the ice-shelf's (1) ice-stream region, where the ice shelf is fed by the fastest ice masses that stream through the upstream bed trough and (2) shear margins, where the ice flow is slower.
The results show that melting below one or both of the shear margins can cause a decadal to centennial increase in ice discharge that is more than twice as large compared to a similar perturbation in the ice-stream region. We attribute this to the fact that melt-induced ice-shelf thinning in the central grounding-line region is attenuated very effectively by the fast flow of the central ice stream. In contrast, the much slower ice dynamics in the lateral shear margins of the ice shelf facilitate sustained ice-shelf thinning and thereby foster buttressing reduction.
Regardless of the melt location, a higher melt concentration toward the grounding line generally goes along with a stronger response. Our results highlight the vulnerability of outlet glaciers to basal melting in stagnant, buttressing-relevant ice-shelf regions, a mechanism that may gain importance under future global warming.
Y1 - 2022
U6 - https://doi.org/10.5194/tc-16-1927-2022
SN - 1994-0416
SN - 1994-0424
VL - 16
IS - 5
SP - 1927
EP - 1940
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Wunderling, Nico
A1 - Willeit, Matteo
A1 - Donges, Jonathan
A1 - Winkelmann, Ricarda
T1 - Global warming due to loss of large ice masses and Arctic summer sea ice
JF - Nature Communications
N2 - Several large-scale cryosphere elements such as the Arctic summer sea ice, the mountain glaciers, the Greenland and West Antarctic Ice Sheet have changed substantially during the last century due to anthropogenic global warming. However, the impacts of their possible future disintegration on global mean temperature (GMT) and climate feedbacks have not yet been comprehensively evaluated. Here, we quantify this response using an Earth system model of intermediate complexity. Overall, we find a median additional global warming of 0.43 degrees C (interquartile range: 0.39-0.46 degrees C) at a CO2 concentration of 400 ppm. Most of this response (55%) is caused by albedo changes, but lapse rate together with water vapour (30%) and cloud feedbacks (15%) also contribute significantly. While a decay of the ice sheets would occur on centennial to millennial time scales, the Arctic might become ice-free during summer within the 21st century. Our findings imply an additional increase of the GMT on intermediate to long time scales. The disintegration of cryosphere elements such as the Arctic summer sea ice, mountain glaciers, Greenland and West Antarctica is associated with temperature and radiative feedbacks. In this work, the authors quantify these feedbacks and find an additional global warming of 0.43 degrees C.
Y1 - 2020
U6 - https://doi.org/10.1038/s41467-020-18934-3
SN - 2041-1723
VL - 11
IS - 1
PB - Nature Publishing Group
CY - Berlin
ER -
TY - JOUR
A1 - Zeitz, Maria
A1 - Reese, Ronja
A1 - Beckmann, Johanna
A1 - Krebs-Kanzow, Uta
A1 - Winkelmann, Ricarda
T1 - Impact of the melt-albedo feedback on the future evolution of the Greenland Ice Sheet with PISM-dEBM-simple
JF - The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union
N2 - Surface melting of the Greenland Ice Sheet contributes a large amount to current and future sea level rise. Increased surface melt may lower the reflectivity of the ice sheet surface and thereby increase melt rates: the so-called melt-albedo feedback describes this self-sustaining increase in surface melting. In order to test the effect of the melt-albedo feedback in a prognostic ice sheet model, we implement dEBM-simple, a simplified version of the diurnal Energy Balance Model dEBM, in the Parallel Ice Sheet Model (PISM). The implementation includes a simple representation of the melt-albedo feedback and can thereby replace the positive-degree-day melt scheme. Using PISM-dEBM-simple, we find that this feedback increases ice loss through surface warming by 60 % until 2300 for the high-emission scenario RCP8.5 when compared to a scenario in which the albedo remains constant at its present-day values. With an increase of 90 % compared to a fixed-albedo scenario, the effect is more pronounced for lower surface warming under RCP2.6. Furthermore, assuming an immediate darkening of the ice surface over all summer months, we estimate an upper bound for this effect to be 70 % in the RCP8.5 scenario and a more than 4-fold increase under RCP2.6. With dEBM-simple implemented in PISM, we find that the melt-albedo feedback is an essential contributor to mass loss in dynamic simulations of the Greenland Ice Sheet under future warming.
Y1 - 2021
U6 - https://doi.org/10.5194/tc-15-5739-2021
SN - 1994-0416
SN - 1994-0424
VL - 15
IS - 12
SP - 5739
EP - 5764
PB - Copernicus
CY - Katlenburg-Lindau
ER -
TY - JOUR
A1 - Klose, Ann Kristin
A1 - Wunderling, Nico
A1 - Winkelmann, Ricarda
A1 - Donges, Jonathan
T1 - What do we mean, 'tipping cascade'?
JF - Environmental research letters : ERL
N2 - Based on suggested interactions of potential tipping elements in the Earth's climate and in ecological systems, tipping cascades as possible dynamics are increasingly discussed and studied. The activation of such tipping cascades would impose a considerable risk for human societies and biosphere integrity. However, there are ambiguities in the description of tipping cascades within the literature so far. Here we illustrate how different patterns of multiple tipping dynamics emerge from a very simple coupling of two previously studied idealized tipping elements. In particular, we distinguish between a two phase cascade, a domino cascade and a joint cascade. A mitigation of an unfolding two phase cascade may be possible and common early warning indicators are sensitive to upcoming critical transitions to a certain degree. In contrast, a domino cascade may hardly be stopped once initiated and critical slowing down-based indicators fail to indicate tipping of the following element. These different potentials for intervention and anticipation across the distinct patterns of multiple tipping dynamics should be seen as a call to be more precise in future analyses of cascading dynamics arising from tipping element interactions in the Earth system.
KW - tipping cascade
KW - domino effect
KW - tipping interactions
KW - cascading regime
KW - shifts
KW - early warning indicators
Y1 - 2021
U6 - https://doi.org/10.1088/1748-9326/ac3955
SN - 1748-9326
VL - 16
IS - 12
PB - IOP Publ. Ltd.
CY - Bristol
ER -
TY - JOUR
A1 - Tiberius, Victor
A1 - Weyland, Michael
T1 - Identifying constituent elements of entrepreneurship curricula
BT - a systematic literature review
JF - Administrative sciences
N2 - Entrepreneurship education research has a strong “output” focus on impact studies but pays much less attention to the “inside” or process perspective of the way entrepreneurship education occurs. In particular, the scattered previous entrepreneurship curriculum research has not managed to provide a current and comprehensive overview of the curricular elements that constitute entrepreneurship education. To overcome this shortcoming, we aim to identify the teaching objectives, teaching contents, teaching methods, and assessment methods discussed in entrepreneurship curriculum research. To this end, we conducted a systematic literature review on the four entrepreneurship curriculum dimensions and collected all mentioned curriculum items. We used a two-stage coding procedure to find the genuinely entrepreneurship-specific items. Among numerous items (also from business management and other subjects), we found 26 objectives, 34 contents, 11 teaching methods, and 7 assessment methods that were entrepreneurship-specific. Most of these items were addressed by only a few scholarly papers.
KW - assessment methods
KW - curriculum
KW - entrepreneurship education
KW - teaching contents
KW - teaching methods
KW - teaching objectives
Y1 - 2023
U6 - https://doi.org/10.3390/admsci14010001
SN - 2076-3387
VL - 14
IS - 1
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Romero Barbosa, Luís
A1 - Coelho, Victor Hugo R.
A1 - Scheiffele, Lena
A1 - Baroni, Gabriele
A1 - Ramos Filho, Geraldo M.
A1 - Montenegro, Suzana M. G. L.
A1 - Das Neves Almeida, Cristiano
A1 - Oswald, Sascha
T1 - Dynamic groundwater recharge simulations based on cosmic-ray neutron sensing in a tropical wet experimental basin
JF - Vadose zone journal : VZJ : advancing critical zone science
N2 - Although cosmic-ray neutron sensing (CRNS) is probably the most promising noninvasive proximal soil moisture measurement technique at the field scale, its application for hydrological simulations remains underexplored in the literature so far. This study assessed the use of CRNS to inversely calibrate soil hydraulic parameters at the intermediate field scale to simulate the groundwater recharge rates at a daily timescale. The study was conducted for two contrasting hydrological years at the Guaraira experimental basin, Brazil, a 5.84-km(2), a tropical wet and rather flat landscape covered by secondary Atlantic forest. As a consequence of the low altitude and proximity to the equator low neutron count rates could be expected, reducing the precision of CRNS while constituting unexplored and challenging conditions for CRNS applications. Inverse calibration for groundwater recharge rates was used based on CRNS or point-scale soil moisture data. The CRNS-derived retention curve and saturated hydraulic conductivity were consistent with the literature and locally performed slug tests. Simulated groundwater recharge rates ranged from 60 to 470 mm yr(-1), corresponding to 5 and 29% of rainfall, and correlated well with estimates based on water table fluctuations. In contrast, the estimated results based on inversive point-scale datasets were not in alignment with measured water table fluctuations. The better performance of CRNS-based estimations of field-scale hydrological variables, especially groundwater recharge, demonstrated its clear advantages over traditional invasive point-scale techniques. Finally, the study proved the ability of CRNS as practicable in low altitude, tropical wet areas, thus encouraging its adoption for water resources monitoring and management.
Y1 - 2021
U6 - https://doi.org/10.1002/vzj2.20145
SN - 1539-1663
VL - 20
IS - 4
PB - Wiley
CY - Hoboken
ER -
TY - JOUR
A1 - Durand, Gael
A1 - van den Broeke, Michiel R.
A1 - Le Cozannet, Goneri
A1 - Edwards, Tamsin L.
A1 - Holland, Paul R.
A1 - Jourdain, Nicolas C.
A1 - Marzeion, Ben
A1 - Mottram, Ruth
A1 - Nicholls, Robert J.
A1 - Pattyn, Frank
A1 - Paul, Frank
A1 - Slangen, Aimee B. A.
A1 - Winkelmann, Ricarda
A1 - Burgard, Clara
A1 - van Calcar, Caroline J.
A1 - Barre, Jean-Baptiste
A1 - Bataille, Amelie
A1 - Chapuis, Anne
T1 - Sea-Level rise: from global perspectives to local services
JF - Frontiers in Marine Science
N2 - Coastal areas are highly diverse, ecologically rich, regions of key socio-economic activity, and are particularly sensitive to sea-level change. Over most of the 20th century, global mean sea level has risen mainly due to warming and subsequent expansion of the upper ocean layers as well as the melting of glaciers and ice caps. Over the last three decades, increased mass loss of the Greenland and Antarctic ice sheets has also started to contribute significantly to contemporary sea-level rise. The future mass loss of the two ice sheets, which combined represent a sea-level rise potential of similar to 65 m, constitutes the main source of uncertainty in long-term (centennial to millennial) sea-level rise projections. Improved knowledge of the magnitude and rate of future sea-level change is therefore of utmost importance. Moreover, sea level does not change uniformly across the globe and can differ greatly at both regional and local scales. The most appropriate and feasible sea level mitigation and adaptation measures in coastal regions strongly depend on local land use and associated risk aversion. Here, we advocate that addressing the problem of future sea-level rise and its impacts requires (i) bringing together a transdisciplinary scientific community, from climate and cryospheric scientists to coastal impact specialists, and (ii) interacting closely and iteratively with users and local stakeholders to co-design and co-build coastal climate services, including addressing the high-end risks.
KW - sea-level rise
KW - Antarctic
KW - Greenland
KW - glaciers
KW - local impact
Y1 - 2022
U6 - https://doi.org/10.3389/fmars.2021.709595
SN - 2296-7745
VL - 8
PB - Frontiers Media
CY - Lausanne
ER -
TY - BOOK
A1 - Leubner, Martin
A1 - Saupe, Anja
T1 - Differenzierung im Literaturunterricht
BT - ein Leitfaden und Aufgabenbeispiele
N2 - Der Band stellt ein Modell für einen differenzierenden Literaturunterricht vor, der individuelle Förderung für unterschiedliche Bereiche von Heterogenität ermöglicht.
Eine ergiebige Differenzierung nutzt die Aspekte Ziele, Themen und Methoden des Unterrichts sowie Lenkung und Aufgabenformat. Diese Aspekte werden mit Blick auf die einzelnen Phasen des Unterrichts präzisiert. Dabei werden Leistungsunterschiede, sprachliche, kulturelle und soziale sowie individuelle Voraussetzungen der einzelnen Schüler:innen deutlicher adressiert.
Einzelne exemplarische Aufgabensets mit ausführlicher Erläuterung dienen der Veranschaulichung des Modells. Zudem werden Unterrichtseinheiten vorgestellt, die systematisch Möglichkeiten der Differenzierung nutzen.
Y1 - 2023
UR - https://www.wbv.de/shop/Differenzierung-im-Literaturunterricht-I73538
SN - 978-3-76397-352-1
SN - 978-3-76397-353-8
U6 - https://doi.org/10.3278/9783763973538
PB - wbv
CY - Bielefeld
ER -
TY - JOUR
A1 - Zielnica, Krzystof
ED - Ette, Ottmar
ED - Knobloch, Eberhard
T1 - Alexander von Humboldt und Polen – zum 150. Jahrestag seiner Reise nach Warschau
BT - mit einleitenden Worten von Ingo Schwarz
JF - HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies
N2 - Zuerst erschienen in:
Alexander von Humboldt-Stiftung. Mitteilungen, 5. Jg., Heft 38, Oktober 1980, S. 27–36.
KW - Verhältnis zu Polen
KW - Ehrenmitglied der Warschauer Gesellschaft der Freunde der Wissenschaften
KW - Julian Ursyn Niemcewicz
KW - Nikolaus I.
KW - Kaiser von Russland und König von Polen (Kongresspolen)
Y1 - 2024
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-646635
SN - 2568-3543
SN - 1617-5239
VL - XXV
IS - 48
SP - 87
EP - 101
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - BOOK
A1 - Franz, Norbert P.
T1 - Der russische Krimi
BT - Buch und Film ; Von Škljarevskij bis Akunin
N2 - Die erste umfassende Darstellung des Kriminalgenres in Russland. Sie geht auf Bücher und Filme ein und berücksichtigt die Debatten der Literaturkritik, da sich die Kulturpolitik während der sowjetischen Jahrzehnte schwer damit tat, dem Kriminalgenre überhaupt ein Existenzrecht zubilligen. Sympathie für die Miliz zu erzeugen wurde schließlich offizieller Zweck dieses politisch zu einer Nischenexistenz gedrängten Genres. Entsprechend liegt ein Akzent der Studie auf der Ideologie, besonders bei der Darstellung der Helden und ihrer Gegner und der Lebenswelt, die die Leser als ihre wiedererkennen sollten. Dabei erfahren sie eine Menge über die Gesellschaft, vor allem über deren sonst eher verschwiegene Schattenseiten.
Nicht zuletzt wegen der langen Entbehrung spannender Texte wurde der Krimi nach dem Ende des Sozialismus zu dem Bestsellergenre schlechthin. Am Beispiel des Frauenkrimis (Marinina und Nachfolgerinnen) und des postmodernen Krimis (Akunin) wird die postsowjetische Entwicklung bis in die 2010er Jahre gezeigt.
N2 - Первое объемное исследование детективного жанра в России. В нем анализируются книги и фильмы, учитываются дебаты в литературной критике, поскольку культурная политика в советские десятилетия не давала криминальному жанру полные права на существование. Создание положительного и привлекательного образа милиции стало в итоге официальной задачей этого жанра, который политически был вынужден существовать в определенной нише. Соответственно в исследовании значительное внимание уделяется идеологии, особенно в изображении героев и их противников, а также их жизненной среды, с которой должен был познакомиться читатель. В процессе чтения он узнает много нового об обществе, особенно о его темной стороне, которую принято было по идеологическим причинам замалчивать.
В годы горбачевской перестройки и гласности детективный роман постепенно стал жанром бестселлера par excellence. Постсоветское развитие вплоть до 2010-х годов показано на примере женского детектива (Маринина и ее преемницы) и постмодернистского криминального романа (Акунин).
N2 - Der russische Krimi presents the first comprehensive account of crime fiction in Russia. It offers detailed discussions of books and movies and also of the broader critical literary debates, as cultural policy during the Soviet decades would not easily grant the crime genre any right to exist. Instead, generating sympathy for the security apparatus eventually became the official purpose of this genre, which was politically relegated to a niche existence. Accordingly, the study places particular emphasis on ideology, especially in the portrayal of the heroes and their opponents and a fictional reality that the reader should nonetheless recognize as his own. In this process, he learns a lot about the darker sides of society that are otherwise mostly kept secret. Not least because of the long-time scarcity of exciting texts, after the end of socialism crime fiction became the bestseller genre par excellence. These post-Soviet developments up to the 2010s are shown using the example of the women's crime novel (Marinina and her successors) and the postmodern crime novel (Akunin).
KW - Russische Kulturgeschichte
KW - Kriminalliteratur
KW - Russische Popularkultur
KW - Sozialistischer Realismus
KW - Frauenkrimi
KW - postmoderner Krimi
KW - Kriminalfilm
KW - Aleksandr Škljarevskij (1837-1883)
KW - Arkadij Adamov (1920-1991)
KW - Arkadij Vajner (1931-2005)
KW - Georgij Vajner (1938-2009)
KW - Aleksandra Marinina (*1957)
KW - Boris Akunin (*1956)
KW - история русской культуры
KW - русская популярная культура
KW - детективный жанр
KW - социалистический реализм
KW - женский детектив
KW - постмодернистский детектив
KW - Russian cultural history
KW - Crime fiction
KW - Russian popular culture
KW - Socialist realism
KW - women’s crime fiction
KW - postmodern crime fiction
Y1 - 2024
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-615591
SN - 978-3-86956-549-1
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - GEN
A1 - Moreno-Romero, Jordi
A1 - Probst, Aline V.
A1 - Trindade, Inês
A1 - Kalyanikrishna,
A1 - Engelhorn, Julia
A1 - Farrona, Sara
T1 - Looking At the Past and Heading to the Future
BT - Meeting Summary of the 6th European Workshop on Plant Chromatin 2019 in Cologne, Germany
T2 - Frontiers in Plant Science
N2 - In June 2019, more than a hundred plant researchers met in Cologne, Germany, for the 6th European Workshop on Plant Chromatin (EWPC). This conference brought together a highly dynamic community of researchers with the common aim to understand how chromatin organization controls gene expression, development, and plant responses to the environment. New evidence showing how epigenetic states are set, perpetuated, and inherited were presented, and novel data related to the three-dimensional organization of chromatin within the nucleus were discussed. At the level of the nucleosome, its composition by different histone variants and their specialized histone deposition complexes were addressed as well as the mechanisms involved in histone post-translational modifications and their role in gene expression. The keynote lecture on plant DNA methylation by Julie Law (SALK Institute) and the tribute session to Lars Hennig, honoring the memory of one of the founders of the EWPC who contributed to promote the plant chromatin and epigenetic field in Europe, added a very special note to this gathering. In this perspective article we summarize some of the most outstanding data and advances on plant chromatin research presented at this workshop.
KW - EWPC2019
KW - chromatin
KW - epigenetics
KW - transcription
KW - nucleus
Y1 - 2020
U6 - https://doi.org/10.3389/fpls.2019.01795
SN - 1664-462X
VL - 10
IS - 1795
SP - 1
EP - 12
PB - Frontiers Media
CY - Lausanne
ER -
TY - GEN
A1 - Grohmann, Nils-Hendrik
T1 - How to avoid politicised monitoring?
BT - treaty-design suggestions for a business and human rights framework convention
T2 - Völkerrechtsblog : Der Blog des Arbeitskreis junger Völkerrechtswissenschaftler*innen
Y1 - 2022
UR - https://voelkerrechtsblog.org/de/how-to-avoid-politicised-monitoring/
U6 - https://doi.org/10.17176/20220623-153108-0
SN - 2510-2567
PB - M. Riegner c/o Humboldt-Univ
CY - Berlin
ER -
TY - JOUR
A1 - Pang, Peter Tsun Ho
A1 - Dietrich, Tim
A1 - Tews, Ingo
A1 - Van Den Broeck, Chris
T1 - Parameter estimation for strong phase transitions in supranuclear matter using gravitational-wave astronomy
JF - Physical review research
N2 - At supranuclear densities, explored in the core of neutron stars, a strong phase transition from hadronic matter to more exotic forms of matter might be present. To test this hypothesis, binary neutron-star mergers offer a unique possibility to probe matter at densities that we cannot create in any existing terrestrial experiment. In this work, we show that, if present, strong phase transitions can have a measurable imprint on the binary neutron-star coalescence and the emitted gravitational-wave signal. We construct a new parametrization of the supranuclear equation of state that allows us to test for the existence of a strong phase transition and extract its characteristic properties purely from the gravitational-wave signal of the inspiraling neutron stars. We test our approach using a Bayesian inference study simulating 600 signals with three different equations of state and find that for current gravitational-wave detector networks already 12 events might be sufficient to verify the presence of a strong phase transition. Finally, we use our methodology to analyze GW170817 and GW190425 but do not find any indication that a strong phase transition is present at densities probed during the inspiral.
Y1 - 2020
U6 - https://doi.org/10.1103/PhysRevResearch.2.033514
SN - 2643-1564
VL - 2
IS - 3
PB - American Physical Society
CY - College Park
ER -
TY - JOUR
A1 - Bosch, Sina
A1 - De Cesare, Ilaria
A1 - Demske, Ulrike
A1 - Felser, Claudia
T1 - Word-order variation and coherence in German infinitival complementation
JF - The journal of comparative Germanic linguistics
N2 - This study provides a synthesis of corpus-based and experimental investigations of word-order preferences in German infinitival complementation. We carried out a systematic analysis of present-day German corpora to establish frequency distributions of different word-order options: extraposition, intraposition, and 'third construction'. We then examined, firstly, whether and to what extent corpus frequencies and processing economy constraints can predict the acceptability of these three word-order variants, and whether subject raising and subject control verbs form clearly distinguishable subclasses of infinitive-embedding verbs in terms of their word-order behaviour. Secondly, our study looks into the issue of coherence by comparing acceptability ratings for monoclausal coherent and biclausal incoherent construals of intraposed infinitives, and by examining whether a biclausal incoherent analysis gives rise to local and/or global processing difficulty. Taken together, our results revealed that (i) whilst the extraposition pattern consistently wins out over all other word-order variants for control verbs, neither frequency nor processing-based approaches to word-order variation can account for the acceptability of low-frequency variants, (ii) there is considerable verb-specific variation regarding word-order preferences both between and within the two sets of raising and control verbs under investigation, and (iii) although monoclausal coherent intraposition is rated above biclausal incoherent intraposition, the latter is not any more difficult to process than the former. Our findings indicate that frequency of occurrence and processing-related constraints interact with idiosyncratic lexical properties of individual verbs in determining German speakers' structural preferences.
KW - Syntactic variation
KW - German
KW - Infinitives
KW - Corpus linguistics
KW - Acceptability judgements
KW - Self-paced reading
Y1 - 2023
U6 - https://doi.org/10.1007/s10828-023-09140-8
SN - 1572-8552
VL - 26
IS - 1
PB - Springer
CY - New York
ER -
TY - JOUR
A1 - Bulla, Mattia
A1 - Coughlin, Michael W.
A1 - Dhawan, Suhail
A1 - Dietrich, Tim
T1 - Multi-messenger constraints on the Hubble constant through combination of gravitational waves, gamma-ray bursts and kilonovae from neutron star mergers
JF - Universe : open access journal
N2 - The simultaneous detection of gravitational waves and light from the binary neutron star merger GW170817 led to independent measurements of distance and redshift, providing a direct estimate of the Hubble constant H-0 that does not rely on a cosmic distance ladder, nor assumes a specific cosmological model.
By using gravitational waves as "standard sirens", this approach holds promise to arbitrate the existing tension between the H-0 value inferred from the cosmic microwave background and those obtained from local measurements.
However, the known degeneracy in the gravitational-wave analysis between distance and inclination of the source led to a H-0 value from GW170817 that was not precise enough to resolve the existing tension.
In this review, we summarize recent works exploiting the viewing-angle dependence of the electromagnetic signal, namely the associated short gamma-ray burst and kilonova, to constrain the system inclination and improve on H-0.
We outline the key ingredients of the different methods, summarize the results obtained in the aftermath of GW170817 and discuss the possible systematics introduced by each of these methods.
KW - gravitational waves
KW - stars: neutron
KW - stars: binaries
KW - cosmology: cosmological parameters
KW - cosmology: distance scale
KW - cosmology: cosmic background radiation
Y1 - 2022
U6 - https://doi.org/10.3390/universe8050289
SN - 2218-1997
VL - 8
IS - 5
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Tiberius, Victor
A1 - Weyland, Michael
T1 - Improving curricula for higher entrepreneurship education
BT - an international real-time Delphi
JF - Education sciences
N2 - Existing curricula for entrepreneurship education do not necessarily represent the best way of teaching. How could entrepreneurship curricula be improved? To answer this question, we aim to identify and rank desirable teaching objectives, teaching contents, teaching methods, and assessment methods for higher entrepreneurship education. To this end, we employ an international real-time Delphi study with an expert panel consisting of entrepreneurship education instructors and researchers. The study reveals 17 favorable objectives, 17 items of content, 25 teaching methods, and 15 assessment methods, which are ranked according to their desirability and the group consensus. We contribute to entrepreneurship curriculum research by adding a normative perspective.
KW - curriculum design
KW - Delphi study
KW - entrepreneurship education
Y1 - 2024
U6 - https://doi.org/10.3390/educsci14020130
SN - 2227-7102
VL - 14
IS - 2
SP - 1
EP - 17
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Lehmann, Nico
A1 - Kuhn, Yves-Alain
A1 - Keller, Martin
A1 - Aye, Norman
A1 - Herold, Fabian
A1 - Draganski, Bogdan
A1 - Taube, Wolfgang
A1 - Taubert, Marco
T1 - Brain activation during active balancing and its behavioral relevance in younger and older adults
BT - a functional near-infrared spectroscopy (fNIRS) study
JF - Frontiers in Aging Neuroscience
N2 - Age-related deterioration of balance control is widely regarded as an important phenomenon influencing quality of life and longevity, such that a more comprehensive understanding of the neural mechanisms underlying this process is warranted.
Specifically, previous studies have reported that older adults typically show higher neural activity during balancing as compared to younger counterparts, but the implications of this finding on balance performance remain largely unclear.
Using functional near-infrared spectroscopy (fNIRS), differences in the cortical control of balance between healthy younger (n = 27) and older (n = 35) adults were explored.
More specifically, the association between cortical functional activity and balance performance across and within age groups was investigated. To this end, we measured hemodynamic responses (i.e., changes in oxygenated and deoxygenated hemoglobin) while participants balanced on an unstable device.
As criterion variables for brain-behavior-correlations, we also assessed postural sway while standing on a free-swinging platform and while balancing on wobble boards with different levels of difficulty.
We found that older compared to younger participants had higher activity in prefrontal and lower activity in postcentral regions.
Subsequent robust regression analyses revealed that lower prefrontal brain activity was related to improved balance performance across age groups, indicating that higher activity of the prefrontal cortex during balancing reflects neural inefficiency.
We also present evidence supporting that age serves as a moderator in the relationship between brain activity and balance, i.e., cortical hemodynamics generally appears to be a more important predictor of balance performance in the older than in the younger. Strikingly, we found that age differences in balance performance are mediated by balancing-induced activation of the superior frontal gyrus, thus suggesting that differential activation of this region reflects a mechanism involved in the aging process of the neural control of balance.
Our study suggests that differences in functional brain activity between age groups are not a mere by-product of aging, but instead of direct behavioral relevance for balance performance.
Potential implications of these findings in terms of early detection of fall-prone individuals and intervention strategies targeting balance and healthy aging are discussed.
KW - aging
KW - neuroimaging
KW - functional near-infrared spectroscopy (fNIRS)
KW - balance
KW - postural control
KW - prefrontal cortex
KW - neural inefficiency
Y1 - 2022
U6 - https://doi.org/10.3389/fnagi.2022.828474
SN - 1663-4365
VL - 14
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Herold, Fabian
A1 - Labott, Berit K.
A1 - Grässler, Bernhard
A1 - Halfpaap, Nicole
A1 - Langhans, Corinna
A1 - Müller, Patrick
A1 - Ammar, Achraf
A1 - Dordevic, Milos
A1 - Hökelmann, Anita
A1 - Müller, Notger Germar
T1 - A Link between Handgrip Strength and Executive Functioning: A Cross-Sectional Study in Older Adults with Mild Cognitive Impairment and Healthy Controls
JF - Healthcare : open access journal
N2 - Older adults with amnestic mild cognitive impairment (aMCI) who in addition to their memory deficits also suffer from frontal-executive dysfunctions have a higher risk of developing dementia later in their lives than older adults with aMCI without executive deficits and older adults with non-amnestic MCI (naMCI). Handgrip strength (HGS) is also correlated with the risk of cognitive decline in the elderly. Hence, the current study aimed to investigate the associations between HGS and executive functioning in individuals with aMCI, naMCI and healthy controls. Older, right-handed adults with amnestic MCI (aMCI), non-amnestic MCI (naMCI), and healthy controls (HC) conducted a handgrip strength measurement via a handheld dynamometer. Executive functions were assessed with the Trail Making Test (TMT A&B). Normalized handgrip strength (nHGS, normalized to Body Mass Index (BMI)) was calculated and its associations with executive functions (operationalized through z-scores of TMT B/A ratio) were investigated through partial correlation analyses (i.e., accounting for age, sex, and severity of depressive symptoms). A positive and low-to-moderate correlation between right nHGS (rp (22) = 0.364; p = 0.063) and left nHGS (rp (22) = 0.420; p = 0.037) and executive functioning in older adults with aMCI but not in naMCI or HC was observed. Our results suggest that higher levels of nHGS are linked to better executive functioning in aMCI but not naMCI and HC. This relationship is perhaps driven by alterations in the integrity of the hippocampal-prefrontal network occurring in older adults with aMCI. Further research is needed to provide empirical evidence for this assumption.
KW - MCI
KW - hippocampal-prefrontal network
KW - handgrip strength
KW - exercise cognition
KW - aging
KW - brain health
Y1 - 2022
U6 - https://doi.org/10.3390/healthcare10020230
SN - 2227-9032
VL - 10
SP - 1
EP - 14
PB - MDPI
CY - Basel, Schweiz
ET - 2
ER -
TY - JOUR
A1 - Spiegel, Thomas J.
T1 - The Scientific Weltanschauung
BT - (Anti-)Naturalism in Dilthey, Jaspers and Analytic Philosophy
JF - Journal of Transcendental Philosophy
N2 - Different forms of methodological and ontological naturalism constitute the current near-orthodoxy in analytic philosophy. Many prominent figures have called naturalism a (scientific) image (Sellars, W. 1962. “Philosophy and the Scientific Image of Man.” In Wilfrid Sellars, Science, Perception, Reality, 1–40. Ridgeview Publishing), a Weltanschauung (Loewer, B. 2001. “From Physics to Physicalism.” In Physicalism and its Discontents, edited by C. Gillett, and B. Loewer. Cambridge: Cambridge University Press; Stoljar, D. 2010. Physicalism. Routledge), or even a “philosophical ideology” (Kim, J. 2003. “The American Origins of Philosophical Naturalism.” Journal of Philosophical Research 28: 83–98). This suggests that naturalism is indeed something over-and-above an ordinary philosophical thesis (e.g. in contrast to the justified true belief-theory of knowledge). However, these thinkers fail to tease out the host of implications this idea – naturalism being a worldview – presents. This paper draws on (somewhat underappreciated) remarks of Dilthey and Jaspers on the concept of worldviews (Weltanschauung, Weltbild) in order to demonstrate that naturalism as a worldview is a presuppositional background assumption which is left untouched by arguments against naturalism as a thesis. The concluding plea is (in order to make dialectical progress) to re-organize the existing debate on naturalism in a way that treats naturalism not as a first-order philosophical claim, but rather shifts its focus on naturalism’s status as a worldview.
KW - naturalism
KW - ideology
KW - Dilthey
KW - Jaspers
KW - scientific image
KW - worldview
Y1 - 2021
U6 - https://doi.org/10.1515/jtph-2021-0016
SN - 2626-8329
SN - 2626-8310
VL - 2
IS - 2
SP - 259
EP - 276
PB - De Gruyter
CY - Berlin ; Boston
ER -
TY - JOUR
A1 - Wachs, Sebastian
A1 - Wright, Michelle F.
A1 - Sittichai, Ruthaychonnee
A1 - Singh, Ritu
A1 - Biswal, Ramakrishna
A1 - Kim, Eun-mee
A1 - Yang, Soeun
A1 - Gámez-Guadix, Manuel
A1 - Almendros, Carmen
A1 - Flora, Katerina
A1 - Daskalou, Vassiliki
A1 - Maziridou, Evdoxia
T1 - Associations between witnessing and perpetrating online hate in eight countries
BT - the buffering effects of problem-focused coping
JF - International Journal of Environmental Research and Public Health
N2 - Online hate is a topic that has received considerable interest lately, as online hate represents a risk to self-determination and peaceful coexistence in societies around the globe. However, not much is known about the explanations for adolescents posting or forwarding hateful online material or how adolescents cope with this newly emerging online risk. Thus, we sought to better understand the relationship between a bystander to and perpetrator of online hate, and the moderating effects of problem-focused coping strategies (e.g., assertive, technical coping) within this relationship. Self-report questionnaires on witnessing and committing online hate and assertive and technical coping were completed by 6829 adolescents between 12 and 18 years of age from eight countries. The results showed that increases in witnessing online hate were positively related to being a perpetrator of online hate. Assertive and technical coping strategies were negatively related with perpetrating online hate. Bystanders of online hate reported fewer instances of perpetrating online hate when they reported higher levels of assertive and technical coping strategies, and more frequent instances of perpetrating online hate when they reported lower levels of assertive and technical coping strategies. In conclusion, our findings suggest that, if effective, prevention and intervention programs that target online hate should consider educating young people about problem-focused coping strategies, self-assertiveness, and media skills. Implications for future research are discussed.
KW - online hate
KW - hate speech
KW - bystander
KW - perpetrator
KW - coping strategies
KW - cyber aggression
Y1 - 2019
U6 - https://doi.org/10.3390/ijerph16203992
SN - 1660-4601
VL - 16
IS - 20
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Balint, Miklos
A1 - Marton, Orsolya
A1 - Schatz, Marlene
A1 - Düring, Rolf-Alexander
A1 - Grossart, Hans-Peter
T1 - Proper experimental design requires randomization/balancing of molecular ecology experiments
JF - Ecology and evolution
N2 - Properly designed (randomized and/or balanced) experiments are standard in ecological research. Molecular methods are increasingly used in ecology, but studies generally do not report the detailed design of sample processing in the laboratory. This may strongly influence the interpretability of results if the laboratory procedures do not account for the confounding effects of unexpected laboratory events. We demonstrate this with a simple experiment where unexpected differences in laboratory processing of samples would have biased results if randomization in DNA extraction and PCR steps do not provide safeguards. We emphasize the need for proper experimental design and reporting of the laboratory phase of molecular ecology research to ensure the reliability and interpretability of results.
KW - batch effect
KW - bias
KW - DNA extraction
KW - environmental DNA
KW - laboratory practice
KW - lake community
KW - metabarcoding
KW - nondemonic intrusions
KW - PCR
KW - sediment
Y1 - 2018
U6 - https://doi.org/10.1002/ece3.3687
SN - 2045-7758
VL - 8
IS - 3
SP - 1786
EP - 1793
PB - Wiley
CY - Hoboken
ER -
TY - JOUR
A1 - Bizic-Ionescu, Mina
A1 - Ionescu, Danny
A1 - Grossart, Hans-Peter
T1 - Organic Particles: Heterogeneous Hubs for Microbial Interactions in Aquatic Ecosystems
JF - Frontiers in microbiology
N2 - The dynamics and activities of microbes colonizing organic particles (hereafter particles) greatly determine the efficiency of the aquatic carbon pump. Current understanding is that particle composition, structure and surface properties, determined mostly by the forming organisms and organic matter, dictate initial microbial colonization and the subsequent rapid succession events taking place as organic matter lability and nutrient content change with microbial degradation. We applied a transcriptomic approach to assess the role of stochastic events on initial microbial colonization of particles. Furthermore, we asked whether gene expression corroborates rapid changes in carbon-quality. Commonly used size fractionated filtration averages thousands of particles of different sizes, sources, and ages. To overcome this drawback, we used replicate samples consisting each of 3–4 particles of identical source and age and further evaluated the consequences of averaging 10–1000s of particles. Using flow-through rolling tanks we conducted long-term experiments at near in situ conditions minimizing the biasing effects of closed incubation approaches often referred to as “the bottle-effect.” In our open flow-through rolling tank system, however, active microbial communities were highly heterogeneous despite an identical particle source, suggesting random initial colonization. Contrasting previous reports using closed incubation systems, expression of carbon utilization genes didn’t change after 1 week of incubation. Consequently, we suggest that in nature, changes in particle-associated community related to carbon availability are much slower (days to weeks) due to constant supply of labile, easily degradable organic matter. Initial, random particle colonization seems to be subsequently altered by multiple organismic interactions shaping microbial community interactions and functional dynamics. Comparative analysis of thousands particles pooled togethers as well as pooled samples suggests that mechanistic studies of microbial dynamics should be done on single particles. The observed microbial heterogeneity and inter-organismic interactions may have important implications for evolution and biogeochemistry in aquatic systems.
KW - particle-associated bacteria
KW - microbial communities
KW - inter- and intra-species interactions
KW - antagonism
KW - phage
KW - transcriptome
Y1 - 2018
U6 - https://doi.org/10.3389/fmicb.2018.02569
SN - 1664-302X
VL - 9
PB - Frontiers Research Foundation
CY - Lausanne
ER -
TY - JOUR
A1 - Wurzbacher, Christian
A1 - Fuchs, Andrea
A1 - Attermeyer, Katrin
A1 - Frindte, Katharina
A1 - Grossart, Hans-Peter
A1 - Hupfer, Michael
A1 - Casper, Peter
A1 - Monaghan, Michael T.
T1 - Shifts among Eukaryota, Bacteria, and Archaea define the vertical organization of a lake sediment
JF - Microbiome
N2 - Background: Lake sediments harbor diverse microbial communities that cycle carbon and nutrients while being constantly colonized and potentially buried by organic matter sinking from the water column. The interaction of activity and burial remained largely unexplored in aquatic sediments. We aimed to relate taxonomic composition to sediment biogeochemical parameters, test whether community turnover with depth resulted from taxonomic replacement or from richness effects, and to provide a basic model for the vertical community structure in sediments. Methods: We analyzed four replicate sediment cores taken from 30-m depth in oligo-mesotrophic Lake Stechlin in northern Germany. Each 30-cm core spanned ca. 170 years of sediment accumulation according to Cs-137 dating and was sectioned into layers 1-4 cm thick. We examined a full suite of biogeochemical parameters and used DNA metabarcoding to examine community composition of microbial Archaea, Bacteria, and Eukaryota. Results: Community beta-diversity indicated nearly complete turnover within the uppermost 30 cm. We observed a pronounced shift from Eukaryota- and Bacteria-dominated upper layers (<5 cm) to Bacteria-dominated intermediate layers (5-14 cm) and to deep layers (>14 cm) dominated by enigmatic Archaea that typically occur in deep-sea sediments. Taxonomic replacement was the prevalent mechanism in structuring the community composition and was linked to parameters indicative of microbial activity (e.g., CO2 and CH4 concentration, bacterial protein production). Richness loss played a lesser role but was linked to conservative parameters (e.g., C, N, P) indicative of past conditions. Conclusions: By including all three domains, we were able to directly link the exponential decay of eukaryotes with the active sediment microbial community. The dominance of Archaea in deeper layers confirms earlier findings from marine systems and establishes freshwater sediments as a potential low-energy environment, similar to deep sea sediments. We propose a general model of sediment structure and function based on microbial characteristics and burial processes. An upper "replacement horizon" is dominated by rapid taxonomic turnover with depth, high microbial activity, and biotic interactions. A lower "depauperate horizon" is characterized by low taxonomic richness, more stable "low-energy" conditions, and a dominance of enigmatic Archaea.
KW - Archaea
KW - Eukaryota
KW - Bacteria
KW - Community
KW - Freshwater
KW - Lake
KW - DNA metabarcoding
KW - Beta-diversity
KW - Sediment
KW - Turnover
Y1 - 2017
U6 - https://doi.org/10.1186/s40168-017-0255-9
SN - 2049-2618
VL - 5
PB - BioMed Central
CY - London
ER -
TY - JOUR
A1 - Göritz, Anna
A1 - Berger, Stella A.
A1 - Gege, Peter
A1 - Grossart, Hans-Peter
A1 - Nejstgaard, Jens C.
A1 - Riedel, Sebastian
A1 - Röttgers, Rüdiger
A1 - Utschig, Christian
T1 - Retrieval of water constituents from hyperspectral in-situ measurements under variable cloud cover
BT - a case study at Lake Stechlin (Germany)
JF - Remote sensing / Molecular Diversity Preservation International (MDPI)
N2 - Remote sensing and field spectroscopy of natural waters is typically performed under clear skies, low wind speeds and low solar zenith angles. Such measurements can also be made, in principle, under clouds and mixed skies using airborne or in-situ measurements; however, variable illumination conditions pose a challenge to data analysis. In the present case study, we evaluated the inversion of hyperspectral in-situ measurements for water constituent retrieval acquired under variable cloud cover. First, we studied the retrieval of Chlorophyll-a (Chl-a) concentration and colored dissolved organic matter (CDOM) absorption from in-water irradiance measurements. Then, we evaluated the errors in the retrievals of the concentration of total suspended matter (TSM), Chl-a and the absorption coefficient of CDOM from above-water reflectance measurements due to highly variable reflections at the water surface. In order to approximate cloud reflections, we extended a recent three-component surface reflectance model for cloudless atmospheres by a constant offset and compared different surface reflectance correction procedures. Our findings suggest that in-water irradiance measurements may be used for the analysis of absorbing compounds even under highly variable weather conditions. The extended surface reflectance model proved to contribute to the analysis of above-water reflectance measurements with respect to Chl-a and TSM. Results indicate the potential of this approach for all-weather monitoring.
KW - remote sensing
KW - inland water
KW - hyperspectral measurements
KW - in-situ
KW - cloud
KW - surface reflection
KW - inversion
KW - bio-optical modeling
Y1 - 2018
U6 - https://doi.org/10.3390/rs10020181
SN - 2072-4292
VL - 10
IS - 2
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Cuadrat, Rafael R. C.
A1 - Ionescu, Danny
A1 - Davila, Alberto M. R.
A1 - Grossart, Hans-Peter
T1 - Recovering genomics clusters of secondary metabolites from lakes using genome-resolved metagenomics
JF - Frontiers in microbiology
N2 - Metagenomic approaches became increasingly popular in the past decades due to decreasing costs of DNA sequencing and bioinformatics development. So far, however, the recovery of long genes coding for secondary metabolites still represents a big challenge. Often, the quality of metagenome assemblies is poor, especially in environments with a high microbial diversity where sequence coverage is low and complexity of natural communities high. Recently, new and improved algorithms for binning environmental reads and contigs have been developed to overcome such limitations. Some of these algorithms use a similarity detection approach to classify the obtained reads into taxonomical units and to assemble draft genomes. This approach, however, is quite limited since it can classify exclusively sequences similar to those available (and well classified) in the databases. In this work, we used draft genomes from Lake Stechlin, north-eastern Germany, recovered by MetaBat, an efficient binning tool that integrates empirical probabilistic distances of genome abundance, and tetranucleotide frequency for accurate metagenome binning. These genomes were screened for secondary metabolism genes, such as polyketide synthases (PKS) and non-ribosomal peptide synthases (NRPS), using the Anti-SMASH and NAPDOS workflows. With this approach we were able to identify 243 secondary metabolite clusters from 121 genomes recovered from our lake samples. A total of 18 NRPS, 19 PKS, and 3 hybrid PKS/NRPS clusters were found. In addition, it was possible to predict the partial structure of several secondary metabolite clusters allowing for taxonomical classifications and phylogenetic inferences. Our approach revealed a high potential to recover and study secondary metabolites genes from any aquatic ecosystem.
KW - metagenomics 2.0
KW - PKS
KW - NRPS
KW - freshwater
KW - environmental genomics
Y1 - 2018
U6 - https://doi.org/10.3389/fmicb.2018.00251
SN - 1664-302X
VL - 9
PB - Frontiers Research Foundation
CY - Lausanne
ER -
TY - JOUR
A1 - Xiao, Shangbin
A1 - Liu, Liu
A1 - Wang, Wei
A1 - Lorke, Andreas
A1 - Woodhouse, Jason Nicholas
A1 - Grossart, Hans-Peter
T1 - A Fast-Response Automated Gas Equilibrator (FaRAGE) for continuous in situ measurement of CH4 and CO2 dissolved in water
JF - Hydrology and earth system sciences : HESS
N2 - Biogenic greenhouse gas emissions, e.g., of methane (CH4) and carbon dioxide (CO2) from inland waters, contribute substantially to global warming. In aquatic systems, dissolved greenhouse gases are highly heterogeneous in both space and time. To better understand the biological and physical processes that affect sources and sinks of both CH4 and CO2, their dissolved concentrations need to be measured with high spatial and temporal resolution. To achieve this goal, we developed the Fast-Response Automated Gas Equilibrator (FaRAGE) for real-time in situ measurement of dissolved CH4 and CO2 concentrations at the water surface and in the water column. FaRAGE can achieve an exceptionally short response time (t(95%) = 12 s when including the response time of the gas analyzer) while retaining an equilibration ratio of 62.6% and a measurement accuracy of 0.5% for CH4. A similar performance was observed for dissolved CO2 (t(95%) = 10 s, equilibration ratio 67.1 %). An equilibration ratio as high as 91.8% can be reached at the cost of a slightly increased response time (16 s). The FaRAGE is capable of continuously measuring dissolved CO2 and CH4 concentrations in the nM-to-submM (10(-9)-10(-3) mol L-1) range with a detection limit of subnM (10(-10) mol L-1), when coupling with a cavity ring-down greenhouse gas analyzer (Picarro GasScouter). FaRAGE allows for the possibility of mapping dissolved concentration in a "quasi" three-dimensional manner in lakes and provides an inexpensive alternative to other commercial gas equilibrators. It is simple to operate and suitable for continuous monitoring with a strong tolerance for suspended particles. While the FaRAGE is developed for inland waters, it can be also applied to ocean waters by tuning the gas-water mixing ratio. The FaRAGE is easily adapted to suit other gas analyzers expanding the range of potential applications, including nitrous oxide and isotopic composition of the gases.
Y1 - 2020
U6 - https://doi.org/10.5194/hess-24-3871-2020
SN - 1027-5606
SN - 1607-7938
VL - 24
IS - 7
SP - 3871
EP - 3880
PB - European Geosciences Union (EGU) ; Copernicus
CY - Munich
ER -
TY - JOUR
A1 - Hoke, Alexa
A1 - Woodhouse, Jason Nicholas
A1 - Zoccarato, Luca
A1 - McCarthy, Valerie
A1 - de Eyto, Elvira
A1 - Caldero-Pascual, Maria
A1 - Geffroy, Ewan
A1 - Dillane, Mary
A1 - Grossart, Hans-Peter
A1 - Jennings, Eleanor
T1 - Impacts of extreme weather events on bacterial community composition of a temperate humic lake
JF - Water
N2 - Extreme weather events are projected to increase in frequency and intensity as climate change continues. Heterotrophic bacteria play a critical role in lake ecosystems, yet little research has been done to determine how they are affected by such extremes. The purpose of this study was to use high-throughput sequencing to explore the bacterial community composition of a humic oligotrophic lake on the North Atlantic Irish coast and to assess the impacts on composition dynamics related to extreme weather events. Samples for sequencing were collected from Lough Feeagh on a fortnightly basis from April to November 2018. Filtration was used to separate free-living and particle-associated bacterial communities and amplicon sequencing was performed for the 16S rRNA V4 region. Two named storms, six high discharge events, and one drought period occurred during the sampling period. These events had variable, context-dependent effects on bacterial communities in Lough Feeagh. The particle-associated community was found to be more likely to respond to physical changes, such as mixing, while the free-living population responded to changes in nutrient and carbon concentrations. Generally, however, the high stability of the bacterial community observed in Lough Feeagh suggests that the bacterial community is relatively resilient to extreme weather events.
KW - extreme weather event
KW - storm
KW - drought
KW - bacteria
KW - free-living
KW - particle-associated
KW - humic lake
Y1 - 2020
U6 - https://doi.org/10.3390/w12102757
SN - 2073-4441
VL - 12
IS - 10
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Schellenberg, Johannes
A1 - Reichert, Jessica
A1 - Hardt, Martin
A1 - Klingelhöfer, Ines
A1 - Morlock, Gertrud
A1 - Schubert, Patrick
A1 - Bižić, Mina
A1 - Grossart, Hans-Peter
A1 - Kämpfer, Peter
A1 - Wilke, Thomas
A1 - Glaeser, Stefanie P.
T1 - The bacterial microbiome of the long-term aquarium cultured high-microbial abundance sponge Haliclona cnidata
BT - sustained bioactivity despite community shifts under detrimental conditions
JF - Frontiers in Marine Science
N2 - Marine sponges host highly diverse but specific bacterial communities that provide essential functions for the sponge holobiont, including antimicrobial defense. Here, we characterized the bacterial microbiome of the marine sponge Haliclona cnidata that has been in culture in an artificial marine aquarium system. We tested the hypotheses (1) that the long-term aquarium cultured sponge H. cnidata is tightly associated with a typical sponge bacterial microbiota and (2) that the symbiotic Bacteria sustain bioactivity under harmful environmental conditions to facilitate holobiont survival by preventing pathogen invasion. Microscopic and phylogenetic analyses of the bacterial microbiota revealed that H. cnidata represents a high microbial abundance (HMA) sponge with a temporally stable bacterial community that significantly shifts with changing aquarium conditions. A 4-week incubation experiment was performed in small closed aquarium systems with antibiotic and/or light exclusion treatments to reduce the total bacterial and photosynthetically active sponge-associated microbiota to a treatment-specific resilient community. While the holobiont was severely affected by the experimental treatment (i.e., bleaching of the sponge, reduced bacterial abundance, shifted bacterial community composition), the biological defense and bacterial community interactions (i.e., quorum sensing activity) remained intact. 16S rRNA gene amplicon sequencing revealed a resilient community of 105 bacterial taxa, which remained in the treated sponges. These 105 taxa accounted for a relative abundance of 72-83% of the bacterial sponge microbiota of non-treated sponge fragments that have been cultured under the same conditions. We conclude that a sponge-specific resilient community stays biologically active under harmful environmental conditions, facilitating the resilience of the holobiont. In H. cnidata, bacteria are located in bacteriocytes, which may have contributed to the observed phenomenon.
KW - HMA sponge
KW - bacterial symbionts
KW - holobiont
KW - antimicrobial defense
KW - quorum sensing
KW - bacteriocytes
Y1 - 2020
U6 - https://doi.org/10.3389/fmars.2020.00266
SN - 2296-7745
VL - 7
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Huang, Lixing
A1 - Qiao, Ying
A1 - Xu, Wei
A1 - Gong, Linfeng
A1 - He, Rongchao
A1 - Qi, Weilu
A1 - Gao, Qiancheng
A1 - Cai, Hongyan
A1 - Grossart, Hans-Peter
A1 - Yan, Qingpi
T1 - Full-length transcriptome
BT - a reliable alternative for single-cell RNA-seq analysis in the spleen of teleost without reference genome
JF - Frontiers in immunology
N2 - Fish is considered as a supreme model for clarifying the evolution and regulatory mechanism of vertebrate immunity. However, the knowledge of distinct immune cell populations in fish is still limited, and further development of techniques advancing the identification of fish immune cell populations and their functions are required. Single cell RNA-seq (scRNA-seq) has provided a new approach for effective in-depth identification and characterization of cell subpopulations. Current approaches for scRNA-seq data analysis usually rely on comparison with a reference genome and hence are not suited for samples without any reference genome, which is currently very common in fish research. Here, we present an alternative, i.e. scRNA-seq data analysis with a full-length transcriptome as a reference, and evaluate this approach on samples from Epinephelus coioides-a teleost without any published genome. We show that it reconstructs well most of the present transcripts in the scRNA-seq data achieving a sensitivity equivalent to approaches relying on genome alignments of related species. Based on cell heterogeneity and known markers, we characterized four cell types: T cells, B cells, monocytes/macrophages (Mo/M phi) and NCC (non-specific cytotoxic cells). Further analysis indicated the presence of two subsets of Mo/M phi including M1 and M2 type, as well as four subsets in B cells, i.e. mature B cells, immature B cells, pre B cells and early-pre B cells. Our research will provide new clues for understanding biological characteristics, development and function of immune cell populations of teleost. Furthermore, our approach provides a reliable alternative for scRNA-seq data analysis in teleost for which no reference genome is currently available.
KW - scRNA-seq
KW - full-length transcriptome
KW - immune cell population
KW - teleost
KW - infection
Y1 - 2021
U6 - https://doi.org/10.3389/fimmu.2021.737332
SN - 1664-3224
VL - 12
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Aichner, Bernhard
A1 - Dubbert, David
A1 - Kiel, Christine
A1 - Kohnert, Katrin
A1 - Ogashawara, Igor
A1 - Jechow, Andreas
A1 - Harpenslager, Sarah-Faye
A1 - Hölker, Franz
A1 - Nejstgaard, Jens Christian
A1 - Grossart, Hans-Peter
A1 - Singer, Gabriel
A1 - Wollrab, Sabine
A1 - Berger, Stella Angela
T1 - Spatial and seasonal patterns of water isotopes in northeastern German lakes
JF - Earth system science data : ESSD
N2 - Water stable isotopes (delta O-18 and delta H-2) were analyzed in samples collected in lakes, associated with riverine systems in northeastern Germany, throughout 2020. The dataset (Aichner et al., 2021; https://doi.org/10.1594/PANGAEA.935633) is derived from water samples collected at (a) lake shores (sampled in March and July 2020), (b) buoys which were temporarily installed in deep parts of the lake (sampled monthly from March to October 2020), (c) multiple spatially distributed spots in four selected lakes (in September 2020), and (d) the outflow of Muggelsee (sampled biweekly from March 2020 to January 2021). At shores, water was sampled with a pipette from 40-60 cm below the water surface and directly transferred into a measurement vial, while at buoys a Limnos water sampler was used to obtain samples from 1 m below the surface. Isotope analysis was conducted at IGB Berlin, using a Picarro L2130-i cavity ring-down spectrometer, with a measurement uncertainty of < 0.15 parts per thousand (delta O-18) and < 0.0 parts per thousand (delta H-2). The data give information about the vegetation period and the full seasonal isotope amplitude in the sampled lakes and about spatial isotope variability in different branches of the associated riverine systems.
Y1 - 2022
U6 - https://doi.org/10.5194/essd-14-1857-2022
SN - 1866-3508
SN - 1866-3516
VL - 14
IS - 4
SP - 1857
EP - 1867
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Ilicic, Doris
A1 - Grossart, Hans-Peter
T1 - Basal parasitic fungi in marine food webs-a mystery yet to unravel
JF - Journal of Fungi
N2 - Although aquatic and parasitic fungi have been well known for more than 100 years, they have only recently received increased awareness due to their key roles in microbial food webs and biogeochemical cycles. There is growing evidence indicating that fungi inhabit a wide range of marine habitats, from the deep sea all the way to surface waters, and recent advances in molecular tools, in particular metagenome approaches, reveal that their diversity is much greater and their ecological roles more important than previously considered. Parasitism constitutes one of the most widespread ecological interactions in nature, occurring in almost all environments. Despite that, the diversity of fungal parasites, their ecological functions, and, in particular their interactions with other microorganisms remain largely speculative, unexplored and are often missing from current theoretical concepts in marine ecology and biogeochemistry. In this review, we summarize and discuss recent research avenues on parasitic fungi and their ecological potential in marine ecosystems, e.g., the fungal shunt, and emphasize the need for further research.
KW - basal fungi
KW - parasites
KW - Chytridiomycota
KW - Rozellomycota
KW - food web
KW - biological carbon pump
Y1 - 2022
U6 - https://doi.org/10.3390/jof8020114
SN - 2309-608X
VL - 8
IS - 2
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Riemann, Lasse
A1 - Rahav, Eyal
A1 - Passow, Uta
A1 - Grossart, Hans-Peter
A1 - de Beer, Dirk
A1 - Klawonn, Isabell
A1 - Eichner, Meri
A1 - Benavides, Mar
A1 - Bar-Zeev, Edo
T1 - Planktonic aggregates as hotspots for heterotrophic diazotrophy: the plot thickens
JF - Frontiers in microbiology
N2 - Biological dinitrogen (N-2) fixation is performed solely by specialized bacteria and archaea termed diazotrophs, introducing new reactive nitrogen into aquatic environments.
Conventionally, phototrophic cyanobacteria are considered the major diazotrophs in aquatic environments. However, accumulating evidence indicates that diverse non-cyanobacterial diazotrophs (NCDs) inhabit a wide range of aquatic ecosystems, including temperate and polar latitudes, coastal environments and the deep ocean. NCDs are thus suspected to impact global nitrogen cycling decisively, yet their ecological and quantitative importance remain unknown. Here we review recent molecular and biogeochemical evidence demonstrating that pelagic NCDs inhabit and thrive especially on aggregates in diverse aquatic ecosystems. Aggregates are characterized by reduced-oxygen microzones, high C:N ratio (above Redfield) and high availability of labile carbon as compared to the ambient water.
We argue that planktonic aggregates are important loci for energetically-expensive N-2 fixation by NCDs and propose a conceptual framework for aggregate-associated N-2 fixation. Future studies on aggregate-associated diazotrophy, using novel methodological approaches, are encouraged to address the ecological relevance of NCDs for nitrogen cycling in aquatic environments.
KW - aggregates
KW - nitrogen fixation
KW - heterotrophic bacteria
KW - marine
KW - aquatic
KW - NCDs
Y1 - 2022
U6 - https://doi.org/10.3389/fmicb.2022.875050
SN - 1664-302X
VL - 13
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Zoccarato, Luca
A1 - Sher, Daniel
A1 - Miki, Takeshi
A1 - Segre, Daniel
A1 - Grossart, Hans-Peter
T1 - A comparative whole-genome approach identifies bacterial traits for marine microbial interactions
JF - Communications biology
N2 - Luca Zoccarato, Daniel Sher et al. leverage publicly available bacterial genomes from marine and other environments to examine traits underlying microbial interactions.
Their results provide a valuable resource to investigate clusters of functional and linked traits to better understand marine bacteria community assembly and dynamics.
Microbial interactions shape the structure and function of microbial communities with profound consequences for biogeochemical cycles and ecosystem health. Yet, most interaction mechanisms are studied only in model systems and their prevalence is unknown. To systematically explore the functional and interaction potential of sequenced marine bacteria, we developed a trait-based approach, and applied it to 473 complete genomes (248 genera), representing a substantial fraction of marine microbial communities.
We identified genome functional clusters (GFCs) which group bacterial taxa with common ecology and life history. Most GFCs revealed unique combinations of interaction traits, including the production of siderophores (10% of genomes), phytohormones (3-8%) and different B vitamins (57-70%). Specific GFCs, comprising Alpha- and Gammaproteobacteria, displayed more interaction traits than expected by chance, and are thus predicted to preferentially interact synergistically and/or antagonistically with bacteria and phytoplankton. Linked trait clusters (LTCs) identify traits that may have evolved to act together (e.g., secretion systems, nitrogen metabolism regulation and B vitamin transporters), providing testable hypotheses for complex mechanisms of microbial interactions.
Our approach translates multidimensional genomic information into an atlas of marine bacteria and their putative functions, relevant for understanding the fundamental rules that govern community assembly and dynamics.
Y1 - 2022
U6 - https://doi.org/10.1038/s42003-022-03184-4
SN - 2399-3642
VL - 5
IS - 1
PB - Springer Nature
CY - Berlin
ER -
TY - GEN
A1 - Wachs, Sebastian
A1 - Wright, Michelle F.
A1 - Sittichai, Ruthaychonnee
A1 - Singh, Ritu
A1 - Biswal, Ramakrishna
A1 - Kim, Eun-mee
A1 - Yang, Soeun
A1 - Gámez-Guadix, Manuel
A1 - Almendros, Carmen
A1 - Flora, Katerina
A1 - Daskalou, Vassiliki
A1 - Maziridou, Evdoxia
T1 - Correction: Associations between witnessing and perpetrating online hate in eight countries: The Buffering Effects of Problem-Focused Coping.
T2 - International Journal Environmental Research and Public Health
Y1 - 2021
U6 - https://doi.org/10.3390/ijerph18052609
SN - 1660-4601
VL - 18
IS - 3992
SP - 1
EP - 2
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Sanchez Sanz, Arturo
A1 - Laudenbach, Benoît
A1 - Weiß, Adrian
A1 - Werner, Eva
A1 - Stachon, Markus
A1 - Anders, Friedrich
A1 - Barthel, Christian
A1 - Berrens, Dominik
A1 - Avalli, Andrea
A1 - Vandewalle, Alexander
A1 - Ferrara, Pasquale
A1 - Pohl, Patrik
ED - Ambühl, Annemarie
ED - Carlà-Uhink, Filippo
ED - Rollinger, Christian
ED - Walde, Christine
T1 - Spring Issue
T2 - thersites
Y1 - 2023
U6 - https://doi.org/10.34679/thersites.vol16
SN - 2364-7612
VL - 2023
IS - 16
ER -
TY - JOUR
A1 - Knobloch, Eberhard
A1 - Kraft, Tobias
A1 - Päßler, Ulrich
A1 - Ette, Ottmar
A1 - Götz, Carmen
A1 - Schwarz, Ingo
ED - Ette, Ottmar
ED - Knobloch, Eberhard
T1 - HiN : Alexander von Humboldt im Netz
N2 - -Eberhard Knobloch: Alexander von Humboldts unbekannter Briefwechsel mit Ludwig August von Buch
-Tobias Kraft und Ulrich Päßler: Das Ganze erfassen. Dem Alexander-von-Humboldt-Forscher Eberhard Knobloch zum 80. Geburtstag
-Ottmar Ette: Vor und nach der „glücklichen Revolution“. Langsdorff, die Berliner Debatte um die Neue Welt und ihre Folgen für die wissenschaftlichen Expeditionen
-Carmen Götz: Die (Un-)Ordnung des Schreibens. Der Index général und die Amerikanischen Reisetagebücher
-Ingo Schwarz: „Jedes ernste wissenschaftliche Streben ist ehrenwert.“ Carl Friedrich von Klödens Rezension des Kosmos von Alexander von Humboldt (1845)
-Tobias Kraft und Ulrich Päßler: Schriftenverzeichnis: Publikationen von Eberhard Knobloch zu Alexander von Humboldt
-Eberhard Knobloch: Alexander von Humboldts Naturgemälde der Anden
T3 - HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies - 47
KW - A. v. Humboldts Rußlandreise
KW - Ludwig August von Buch
KW - Preußische Legation am Römischen Hof
KW - Eberhard Knobloch
KW - 80. Geburtstag
KW - Berliner Debatte um die Neue Welt
KW - Antoine-Joseph Pernety
KW - Cornelius de Pauw
KW - Georg Heinrich Freiherr von Langsdorff
KW - Aufklärung
KW - République des Lettres
KW - Amerikanische Reisetagebücher
KW - Index général
KW - Paginierung
KW - Vollständigkeit
KW - Überlieferungszustand
KW - Ordnung
KW - Unordnung
KW - Alexander von Humboldts Kosmos
KW - Rezension
KW - Carl Friedrich von Klöden
KW - Vossische Zeitung
KW - Eduard Buschmann
KW - Schriftenverzeichnis
KW - Bibliografie
Y1 - 2023
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-611678
SN - 2568-3543
SN - 1617-5239
VL - XXIV
IS - 47
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - JOUR
A1 - Inceoglu, Fadil
A1 - Shprits, Yuri
A1 - Heinemann, Stephan G.
A1 - Bianco, Stefano
T1 - Identification of coronal holes on AIA/SDO images using unsupervised machine learning
JF - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2 - Through its magnetic activity, the Sun governs the conditions in Earth's vicinity, creating space weather events, which have drastic effects on our space- and ground-based technology.
One of the most important solar magnetic features creating the space weather is the solar wind that originates from the coronal holes (CHs).
The identification of the CHs on the Sun as one of the source regions of the solar wind is therefore crucial to achieve predictive capabilities.
In this study, we used an unsupervised machine-learning method, k-means, to pixel-wise cluster the passband images of the Sun taken by the Atmospheric Imaging Assembly on the Solar Dynamics Observatory in 171, 193, and 211 angstrom in different combinations.
Our results show that the pixel-wise k-means clustering together with systematic pre- and postprocessing steps provides compatible results with those from complex methods, such as convolutional neural networks.
More importantly, our study shows that there is a need for a CH database where a consensus about the CH boundaries is reached by observers independently.
This database then can be used as the "ground truth," when using a supervised method or just to evaluate the goodness of the models.
Y1 - 2022
U6 - https://doi.org/10.3847/1538-4357/ac5f43
SN - 1538-4357
VL - 930
IS - 2
PB - IOP Publ. Ltd.
CY - Bristol
ER -
TY - JOUR
A1 - Smirnov, Artem G.
A1 - Kronberg, Elena A.
A1 - Daly, Patrick W.
A1 - Aseev, Nikita
A1 - Shprits, Yuri
A1 - Kellerman, Adam C.
T1 - Adiabatic Invariants Calculations for Cluster Mission: A Long-Term Product for Radiation Belts Studies
JF - Journal of Geophysical Research: Space Physics
N2 - The Cluster mission has produced a large data set of electron flux measurements in the Earth's magnetosphere since its launch in late 2000. Electron fluxes are measured using Research with Adaptive Particle Imaging Detector (RAPID)/Imaging Electron Spectrometer (IES) detector as a function of energy, pitch angle, spacecraft position, and time. However, no adiabatic invariants have been calculated for Cluster so far. In this paper we present a step-by-step guide to calculations of adiabatic invariants and conversion of the electron flux to phase space density (PSD) in these coordinates. The electron flux is measured in two RAPID/IES energy channels providing pitch angle distribution at energies 39.2-50.5 and 68.1-94.5 keV in nominal mode since 2004. A fitting method allows to expand the conversion of the differential fluxes to the range from 40 to 150 keV. Best data coverage for phase space density in adiabatic invariant coordinates can be obtained for values of second adiabatic invariant, K, similar to 10(2), and values of the first adiabatic invariant mu in the range approximate to 5-20 MeV/G. Furthermore, we describe the production of a new data product "LSTAR," equivalent to the third adiabatic invariant, available through the Cluster Science Archive for years 2001-2018 with 1-min resolution. The produced data set adds to the availability of observations in Earth's radiation belts region and can be used for long-term statistical purposes.
KW - L-Asterisk
KW - magnetosphere
KW - electrons
KW - model
Y1 - 2019
VL - 125
IS - 2
PB - John Wiley & Sons, Inc.
CY - New Jersey
ER -
TY - JOUR
A1 - Kuhlman, Sabine
T1 - Back to bureaucracy?
BT - the advent of the neo-weberian state in Germany
JF - Journal of policy studies
N2 - In this contribution, the emergence of the neo-Weberian state (NWS) is analyzed with regard to German public administration. Drawing on the concept of a governance space, which consists of a hierarchy, markets, and networks, we distinguish between four empirical manifestations of the NWS, namely, the NWS as (1) come back of the public/ re-municipalization; (2) re-hierarchization; (3) de-agencification; (4) de-escalation in performance management. These movements can, on the one hand, be interpreted as a (partial) reversal of New Public Management (NPM) approaches and a “swinging back of the pendulum” (see Kuhlmann & Wollmann, 2019) toward public and classical Weberian principles (e.g., hierarchy, regulation, institutional re-aggregation). This reversal re-strengthened the hierarchy within the overall governance space to the detriment of, but without completely replacing, market mechanisms and networks. NPM’s failure to deliver what it promised and its inappropriateness as a response to more recent challenges connected to crises and wicked problems have engendered a partial return of the public and a move away from the economization logic of NPM. On the other hand, post-NPM reversals and managerial de-escalation gave rise to hybrid models that merge NPM and classic Weberian administration. While some well-functioning combinations of NPM and Weberianism exist, the hybridization of “old” and “neo” elements has also provoked ambivalent and negative assessments regarding the actual functioning of the NWS in Germany. Our analysis suggests that the NWS is only partially suitable as a model for reform and future administrative modernization, largely depending on the context surrounding reform and implementation practices.
KW - weo-weberian State
KW - bureaucracy
KW - post-new public management
KW - hierarchy
KW - re-municipalization
KW - crisis
Y1 - 2024
U6 - https://doi.org/10.52372/jps39202
SN - 2799-9130
SN - 2800-0714
VL - 39
IS - 2
SP - 11
EP - 44
PB - Graduate School of Public Administration
CY - Seoul
ER -
TY - JOUR
A1 - Asante, Drusilla Obenewaa
A1 - Osei, Francis
A1 - Abdul-Samed, Fridaus
A1 - Nanevie, Victoria Dzifa
T1 - Knowledge and participation in exercise and physical activity among pregnant women in Ho, Ghana
JF - Frontiers in Public Health
N2 - Background
Physical activity (PA) and exercise have been identified to improve the general fitness and health.
Although, the Pregnancy Physical Activity Questionnaire (PPAQ) has been validated for use in assessing PA in pregnant women. However, understanding the knowledge and participation levels of PA in pregnant women in the underdeveloped regions of Ghana is of clinical relevance to foster education and promotion of PA. In Ghana, pregnant women believe the "myth" (mostly in rural areas and underdeveloped regions) that exercising in the first trimester might lead to miscarriage.
Thus, the main objective of this study was to investigate the extent of knowledge and participation levels in PA among pregnant women in Ho, Ghana using a self-developed questionnaire which consisted of some questions adapted from the PPAQ. MethodsSeventy-seven (n = 77) pregnant women between the ages of 18-50 years were recruited from three hospitals across the Ho municipality of Ghana.
A self-developed questionnaire which consisted of some questions taken from the PPAQ was administered to participants under the researchers' supervision. Spearman's correlation analysis was used to find the association between the level of participation in PA, knowledge of PA and gestational age among pregnant women.
Results
From the total participants (n = 77) recruited, 57 (74%) of the participants scored high in PA knowledge.
Most of the participants 48 (62.3%) answered that PA promotes healthy pregnancy. Participants who reported barriers to PA during pregnancy were no exercise habits 51 (66.2%), having no time 17 (22.1%) and fear of miscarriage 9 (11.7%).
There was a significant (p < 0.05) association between the level of participation and gestational age. No significant (p > 0.05) association between the level of participation and knowledge of PA was observed.
Conclusion
There is a high level of knowledge of PA among pregnant women in Ho, Ghana. However, most pregnant women rather engage in PA as their gestational age increases. Thus, to foster sustainable exercise participation during pregnancy, all healthcare providers saddled with the responsibility of providing maternal healthcare must strengthen the education and promotion of exercise and PA among pregnant women in Ho, Ghana.
KW - physical activity
KW - barriers to physical activity
KW - education
KW - pregnancy
KW - gestational age
Y1 - 2022
U6 - https://doi.org/10.3389/fpubh.2022.927191
SN - 2296-2565
VL - 10
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - von Steinkeller, Annika
A1 - Grosse, Gerlind
T1 - Children are more social when playing analog games together than digital games
JF - Computers in Human Behavior Reports
N2 - Digital media are being used more and more frequently by children and for a wide variety of functions.
However, there are no studies to date that examine the effect of such use on peer interactions and the occurrence of prosocial behavior in peers.
For parents, it has been found that when using digital media only few parents respond responsively to their children's attempts at interaction and also very rarely, they communicate with them verbally and nonverbally.
In the present study, we investigated how playing a game in a digital versus analog form influences in-teractions (especially prosocial behavior) of peers.
We used an experimental situation, where 24 dyads of 4-10-year-old children were examined. Each of the dyads was randomly assigned to a condition where they played either a digital or analog game together. Various interaction parameters and prosocial behavior during and after the game were analyzed.
Results show that children in the analog condition communicated verbally with each other more often, responded more often to interaction attempts of their partners and showed less often negative forms of inter-action and more often positive forms of interaction than children in the digital condition.
However, the type of medium had no influence on prosocial behavior after the game situation.
These results suggest that the format of a game (digital vs. analog) has a decisive influence on peer interactions concerning their communication during but not their prosocial behavior after the game situation.
KW - child development
KW - peer interactions
KW - media
KW - prosocial behavior
KW - digital
KW - games
Y1 - 2022
U6 - https://doi.org/10.1016/j.chbr.2022.100195
SN - 2451-9588
VL - 6
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Winkelbeiner, Nicola Lisa
A1 - Wandt, Viktoria Klara Veronika
A1 - Ebert, Franziska
A1 - Lossow, Kristina
A1 - Bankoglu, Ezgi E.
A1 - Martin, Maximilian
A1 - Mangerich, Aswin
A1 - Stopper, Helga
A1 - Bornhorst, Julia
A1 - Kipp, Anna Patricia
A1 - Schwerdtle, Tanja
T1 - A Multi-Endpoint Approach to Base Excision Repair Incision Activity Augmented by PARylation and DNA Damage Levels in Mice
BT - Impact of Sex and Age
JF - International Journal of Molecular Sciences
N2 - Investigation of processes that contribute to the maintenance of genomic stability is one crucial factor in the attempt to understand mechanisms that facilitate ageing. The DNA damage response (DDR) and DNA repair mechanisms are crucial to safeguard the integrity of DNA and to prevent accumulation of persistent DNA damage. Among them, base excision repair (BER) plays a decisive role. BER is the major repair pathway for small oxidative base modifications and apurinic/apyrimidinic (AP) sites. We established a highly sensitive non-radioactive assay to measure BER incision activity in murine liver samples. Incision activity can be assessed towards the three DNA lesions 8-oxo-2’-deoxyguanosine (8-oxodG), 5-hydroxy-2’-deoxyuracil (5-OHdU), and an AP site analogue. We applied the established assay to murine livers of adult and old mice of both sexes. Furthermore, poly(ADP-ribosyl)ation (PARylation) was assessed, which is an important determinant in DDR and BER. Additionally, DNA damage levels were measured to examine the overall damage levels. No impact of ageing on the investigated endpoints in liver tissue were found. However, animal sex seems to be a significant impact factor, as evident by sex-dependent alterations in all endpoints investigated. Moreover, our results revealed interrelationships between the investigated endpoints indicative for the synergetic mode of action of the cellular DNA integrity maintaining machinery.
KW - maintenance of genomic integrity
KW - ageing
KW - sex
KW - DNA damage
KW - base excision repair (incision activity)
KW - DNA damage response
KW - poly(ADP-ribosyl)ation
KW - liver
Y1 - 2020
U6 - https://doi.org/10.3390/ijms21186600
SN - 1422-0067
VL - 21
IS - 18
PB - Molecular Diversity Preservation International
CY - Basel
ER -
TY - JOUR
A1 - Schmidt, Hendrikje
A1 - Felisatti, Arianna
A1 - Aster, Michael von
A1 - Wilbert, Jürgen
A1 - Moers, Arpad von
A1 - Fischer, Martin H.
T1 - Neuromuscular diseases affect number representation and processing
BT - An exploratory study
JF - Frontiers in psychology / Frontiers Research Foundation
N2 - Spinal muscular atrophy (SMA) and Duchenne muscular dystrophy (DMD) both are rare genetic neuromuscular diseases with progressive loss of motor ability. The neuromotor developmental course of those diseases is well documented. In contrast, there is only little evidence about characteristics of general and specific cognitive development. In both conditions the final motor outcome is characterized by an inability to move autonomously: children with SMA never accomplish independent motoric exploration of their environment, while children with DMD do but later lose this ability again. These profound differences in developmental pathways might affect cognitive development of SMA vs. DMD children, as cognition is shaped by individual motor experiences. DMD patients show impaired executive functions, working memory, and verbal IQ, whereas only motor ability seems to be impaired in SMA. Advanced cognitive capacity in SMA may serve as a compensatory mechanism for achieving in education, career progression, and social satisfaction. This study aimed to relate differences in basic numerical concepts and arithmetic achievement in SMA and DMD patients to differences in their motor development and resulting sensorimotor and environmental experiences. Horizontal and vertical spatial-numerical associations were explored in SMA/DMD children ranging between 6 and 12 years through the random number generation task. Furthermore, arithmetic skills as well as general cognitive ability were assessed. Groups differed in spatial number processing as well as in arithmetic and domain-general cognitive functions. Children with SMA showed no horizontal and even reversed vertical spatial-numerical associations. Children with DMD on the other hand revealed patterns in spatial numerical associations comparable to healthy developing children. From the embodied Cognition perspective, early sensorimotor experience does play a role in development of mental number representations. However, it remains open whether and how this becomes relevant for the acquisition of higher order cognitive and arithmetic skills.
KW - spatial-numerical associations
KW - numerical processing
KW - mathematics
KW - child development
KW - embodied cognition
KW - neuromuscular disease
KW - spinal muscular atrophy
KW - Duchenne muscular dystrophy
Y1 - 2021
U6 - https://doi.org/10.3389/fpsyg.2021.697881
SN - 1664-1078
VL - 12
PB - Frontiers Research Foundation
CY - Lausanne
ER -
TY - JOUR
A1 - Richly, Keven
A1 - Brauer, Janos
A1 - Schlosser, Rainer
T1 - Predicting location probabilities of drivers to improved dispatch decisions of transportation network companies based on trajectory data
JF - Proceedings of the 9th International Conference on Operations Research and Enterprise Systems - ICORES
N2 - The demand for peer-to-peer ridesharing services increased over the last years rapidly. To cost-efficiently dispatch orders and communicate accurate pick-up times is challenging as the current location of each available driver is not exactly known since observed locations can be outdated for several seconds. The developed trajectory visualization tool enables transportation network companies to analyze dispatch processes and determine the causes of unexpected delays. As dispatching algorithms are based on the accuracy of arrival time predictions, we account for factors like noise, sample rate, technical and economic limitations as well as the duration of the entire process as they have an impact on the accuracy of spatio-temporal data. To improve dispatching strategies, we propose a prediction approach that provides a probability distribution for a driver’s future locations based on patterns observed in past trajectories. We demonstrate the capabilities of our prediction results to ( i) avoid critical delays, (ii) to estimate waiting times with higher confidence, and (iii) to enable risk considerations in dispatching strategies.
KW - trajectory data
KW - location prediction algorithm
KW - Peer-to-Peer ridesharing
KW - transport network companies
KW - risk-aware dispatching
Y1 - 2020
PB - Springer
CY - Berlin
ER -
TY - JOUR
A1 - Wagner, Birgit
A1 - Rosenberg, Nicole
A1 - Hofmann, Laura
A1 - Maaß, Ulrike
T1 - Web-based bereavement care
BT - a systematic review and meta-analysis
JF - Frontiers in psychiatry
N2 - Background:
Web-based interventions have been introduced as novel and effective treatments for mental disorders and, in recent years, specifically for the bereaved. However, a systematic summary of the effectiveness of online interventions for people experiencing bereavement is still missing.
Objective:
A systematic literature search was conducted by four reviewers who reviewed and meta-analytically summarized the evidence for web-based interventions for bereaved people.
Methods:
Systematic searches (PubMed, Web of Science, PsycInfo, PsycArticles, Medline, and CINAHL) resulted in seven randomized controlled trials (N= 1,257) that addressed adults having experienced bereavement using internet-based interventions. We used random effects models to summarize treatment effects for between-group comparisons (treatmentvs.control at post) and stability over time (postvs.follow-up).
Results:
All web-based interventions were based on cognitive behavioral therapy (CBT). In comparison with control groups, the interventions showed moderate (g= .54) to large effects (g= .86) for symptoms of grief and posttraumatic stress disorder (PTSD), respectively. The effect for depression was small (g= .44). All effects were stable over time. A higher number of treatment sessions achieved higher effects for grief symptoms and more individual feedback increased effects for depression. Other moderators (i.e.dropout rate, time since loss, exposure) did not significantly reduce moderate degrees of heterogeneity between the studies.
Limitations:
The number of includable studies was low in this review resulting to lower power for moderator analyses in particular.
Conclusions:
Overall, the results of web-based bereavement interventions are promising, and its low-threshold approach might reduce barriers to bereavement care. Nonetheless, future research should further examine potential moderators and specific treatment components (e.g.exposure, feedback) and compare interventions with active controls.
KW - grief
KW - bereavement
KW - depression
KW - post-traumatic stress disorder
KW - internet
KW - e-health
KW - intervention
KW - psychotherapy
Y1 - 2020
U6 - https://doi.org/10.3389/fpsyt.2020.00525
SN - 1664-0640
VL - 11
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Wagner, Birgit
A1 - Hofmann, Laura
A1 - Maaß, Ulrike
T1 - Online-group intervention after suicide bereavement through the use of webinars
BT - study protocol for a randomized controlled trial
JF - Trials
N2 - Introduction:
The death of a significant person through suicide is a very difficult experience and can have long-term impact on an individual's psychosocial and physical functioning. However, there are only few studies that have examined the effects of interventions in suicide survivors. In the present study, we examine an online-group intervention for people bereaved by suicide using a group-webinar.
Methods:
The intervention was developed based on focus groups with the target group. The cognitive-behavioral 12-module webinar-based group intervention focuses on suicide bereavement-related themes such as feelings of guilt, stigmatization, meaning reconstruction and the relationship to the deceased. Further, the webinar includes testimonial videos and psychoeducation. The suicide survivors are randomized to the intervention or the waiting list in a group-cluster randomized controlled trial. Primary outcomes are suicidality (Beck Scale for Suicide Ideation) and depression (Beck Depression Inventory-II) and secondary outcomes are symptoms of prolonged grief disorder (Inventory of Complicated Grief-German Version ), posttraumatic stress disorder ( Revised Impact of Event Scale ), stigmatization (Stigma of Suicide and Suicide Survivor ) and posttraumatic cognitions (Posttraumatic Cognitions Inventory).
Discussion:
Previous studies of Internet-based interventions for the bereaved were based on writing interventions showing large treatment effects. Little is known about the use of webinars as group interventions. Advantages and challenges of this novel approach of psychological interventions will be discussed.
KW - Suicide bereavement
KW - grief
KW - group intervention
KW - webinar
KW - suicidality
KW - prolonged grief disorder
KW - randomized controlled trial
Y1 - 2020
U6 - https://doi.org/10.1186/s13063-019-3891-5
SN - 1468-6694
SN - 1745-6215
VL - 21
IS - 1
PB - BioMed Central
CY - London
ER -
TY - JOUR
A1 - Maaß, Ulrike
A1 - Kühne, Franziska
A1 - Heinze, Peter Eric
A1 - Ay-Bryson, Destina Sevde
A1 - Weck, Florian
T1 - The concise measurement of clinical communication skills
BT - Validation of a short scale
JF - Frontiers in Psychiatry
N2 - Objective: There is a lack of brief rating scales for the reliable assessment of psychotherapeutic skills, which do not require intensive rater training and/or a high level of expertise. Thus, the objective is to validate a 14-item version of the Clinical Communication Skills Scale (CCSS-S).
Methods: Using a sample of N = 690 video-based ratings of role-plays with simulated patients, we calculated a confirmatory factor analysis and an exploratory structural equation modeling (ESEM), assessed convergent validities, determined inter-rater reliabilities and compared these with those who were either psychology students, advanced psychotherapy trainees, or experts.
Results: Correlations with other competence rating scales were high (rs > 0.86–0.89). The intraclass correlations ranged between moderate and good [ICC(2,2) = 0.65–0.80], with student raters yielding the lowest scores. The one-factor model only marginally replicated the data, but the internal consistencies were excellent (α = 0.91–95). The ESEM yielded a two-factor solution (Collaboration and Structuring and Exploration Skills).
Conclusion: The CCSS-S is a brief and valid rating scale that reliably assesses basic communication skills, which is particularly useful for psychotherapy training using standardized role-plays. To ensure good inter-rater reliabilities, it is still advisable to employ raters with at least some clinical experience. Future studies should further investigate the one- or two-factor structure of the instrument.
KW - standardized patient
KW - treatment integrity
KW - measurement
KW - therapist competence
KW - role-play
KW - psychotherapy process
Y1 - 2022
U6 - https://doi.org/10.3389/fpsyt.2022.977324
SN - 1664-0640
VL - 13
PB - Frontiers
CY - Lausanne, Schweiz
ER -
TY - JOUR
A1 - Felisatti, Arianna
A1 - Aagten-Murphy, David
A1 - Laubrock, Jochen
A1 - Shaki, Samuel
A1 - Fischer, Martin H.
T1 - The brain’s asymmetric frequency tuning
BT - asymmetric behavior originates from asymmetric perception
JF - Symmetry / Molecular Diversity Preservation International (MDPI)
N2 - To construct a coherent multi-modal percept, vertebrate brains extract low-level features (such as spatial and temporal frequencies) from incoming sensory signals. However, because frequency processing is lateralized with the right hemisphere favouring low frequencies while the left favours higher frequencies, this introduces asymmetries between the hemispheres. Here, we describe how this lateralization shapes the development of several cognitive domains, ranging from visuo-spatial and numerical cognition to language, social cognition, and even aesthetic appreciation, and leads to the emergence of asymmetries in behaviour. We discuss the neuropsychological and educational implications of these emergent asymmetries and suggest future research approaches.
KW - asymmetry
KW - global
KW - local
KW - spatial frequencies
KW - temporal frequencies
KW - embodied cognition
Y1 - 2020
U6 - https://doi.org/10.3390/sym12122083
SN - 2073-8994
VL - 12
IS - 12
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Heistermann, Maik
A1 - Francke, Till
A1 - Scheiffele, Lena
A1 - Petrova, Katya Dimitrova
A1 - Budach, Christian
A1 - Schrön, Martin
A1 - Trost, Benjamin
A1 - Rasche, Daniel
A1 - Güntner, Andreas
A1 - Doepper, Veronika
A1 - Förster, Michael
A1 - Köhli, Markus
A1 - Angermann, Lisa
A1 - Antonoglou, Nikolaos
A1 - Zude, Manuela
A1 - Oswald, Sascha
T1 - Three years of soil moisture observations by a dense cosmic-ray neutron sensing cluster at an agricultural research site in north-east Germany
JF - Earth system science data : ESSD
N2 - Cosmic-ray neutron sensing (CRNS) allows for the estimation of root-zone soil water content (SWC) at the scale of several hectares. In this paper, we present the data recorded by a dense CRNS network operated from 2019 to 2022 at an agricultural research site in Marquardt, Germany - the first multi-year CRNS cluster. Consisting, at its core, of eight permanently installed CRNS sensors, the cluster was supplemented by a wealth of complementary measurements: data from seven additional temporary CRNS sensors, partly co-located with the permanent ones; 27 SWC profiles (mostly permanent); two groundwater observation wells; meteorological records; and Global Navigation Satellite System reflectometry (GNSS-R). Complementary to these continuous measurements, numerous campaign-based activities provided data by mobile CRNS roving, hyperspectral im-agery via UASs, intensive manual sampling of soil properties (SWC, bulk density, organic matter, texture, soil hydraulic properties), and observations of biomass and snow (cover, depth, and density). The unique temporal coverage of 3 years entails a broad spectrum of hydro-meteorological conditions, including exceptional drought periods and extreme rainfall but also episodes of snow coverage, as well as a dedicated irrigation experiment. Apart from serving to advance CRNS-related retrieval methods, this data set is expected to be useful for vari-ous disciplines, for example, soil and groundwater hydrology, agriculture, or remote sensing. Hence, we show exemplary features of the data set in order to highlight the potential for such subsequent studies. The data are available at doi.org/10.23728/b2share.551095325d74431881185fba1eb09c95 (Heistermann et al., 2022b).
Y1 - 2023
U6 - https://doi.org/10.5194/essd-15-3243-2023
SN - 1866-3508
SN - 1866-3516
VL - 15
IS - 7
SP - 3243
EP - 3262
PB - Copernics Publications
CY - Katlenburg-Lindau
ER -
TY - BOOK
A1 - Pürgstaller, Esther
A1 - Neuber, Nils
ED - Pürgstaller, Esther
ED - Neuber, Nils
T1 - Tänzerischer Kreativitätstest für 8- bis 12-Jährige
BT - Testmanual
N2 - Der tänzerische Kreativitätstest stellt ein valides Instrumentarium dar, welches auf tanzspezifischen Aufgaben basiert und für die differenzierte und standardisierte Erfassung der tänzerischen Kreativität bei Kindern im Alter von 8 bis 12 Jahren konzipiert ist. Mit dem tänzerischen Kreativitätstest können nicht nur Fragestellungen zum Stand sowie zur Entwicklung tänzerisch-kreativer Fähigkeiten im Kindesalter bearbeitet werden, sondern er liefert auch wertvolle Informationen für die Optimierung von Trainings-, Förder- und Vermittlungsmaßnahmen. Erfasst werden folgende tänzerisch-kreativen Fähigkeiten: 1) Vielfalt und Originalität in der Fortbewegung und in Körperpositionen sowie 2) Ideenreichtum, Vielfalt und Originalität in der Gestaltung von Bewegungspatterns und -kompositionen. Dieser Test lässt sich mit größeren Gruppen und minimalem materiellen Aufwand durchführen, ist zeitlich unbeschränkt und ermöglicht es, unterschiedliche Leistungsniveaus zu identifizieren. Der tänzerische Kreativitätstest bietet Forschenden und Lehrkräften eine wertvolle Möglichkeit, die tänzerisch-kreativen Fähigkeiten von Kindern zu analysieren und zu fördern.
N2 - The dance creativity test represents a valid instrument based on dance-specific tasks, designed for the differentiated and standardized evaluation of dance creativity in children aged 8 to 12 years. With the dance creativity test questions regarding the status and development of dance-creative abilities in childhood be addressed. It also provides valuable information for optimizing training, promotion, and teaching. The following dance-creative abilities are captured: 1) Variety and originality in locomotor movements and body shapes, and 2) Fluency, variety, and originality in movement patterns and compositions. This test can be conducted with larger groups and minimal material effort, is not time-restricted, and allows for the identification of different performance levels. The dance creativity test offers researchers and teachers a valuable opportunity to analyze and promote the dance creative abilities of children.
KW - Kreativitätstest
KW - Tanz
KW - Test
KW - Testmanual
KW - Kinder
KW - creativity test
KW - dance
KW - test
KW - test manual
KW - children
Y1 - 2024
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-627040
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - JOUR
A1 - Smirnov, Artem
A1 - Shprits, Yuri
A1 - Allison, Hayley
A1 - Aseev, Nikita
A1 - Drozdov, Alexander
A1 - Kollmann, Peter
A1 - Wang, Dedong
A1 - Saikin, Anthony
T1 - Storm-Time evolution of the Equatorial Electron Pitch Angle Distributions in Earth's Outer Radiation Belt
JF - Frontiers in astronomy and space sciences
N2 - In this study we analyze the storm-time evolution of equatorial electron pitch angle distributions (PADs) in the outer radiation belt region using observations from the Magnetic Electron Ion Spectrometer (MagEIS) instrument aboard the Van Allen Probes in 2012-2019. The PADs are approximated using a sum of the first, third and fifth sine harmonics. Different combinations of the respective coefficients refer to the main PAD shapes within the outer radiation belt, namely the pancake, flat-top, butterfly and cap PADs. We conduct a superposed epoch analysis of 129 geomagnetic storms and analyze the PAD evolution for day and night MLT sectors. PAD shapes exhibit a strong energy-dependent response. At energies of tens of keV, the PADs exhibit little variation throughout geomagnetic storms. Cap PADs are mainly observed at energies < 300 keV, and their extent in L shrinks with increasing energy. The cap distributions transform into the pancake PADs around the main phase of the storm on the nightside, and then come back to their original shapes during the recovery phase. At higher energies on the dayside, the PADs are mainly pancake during pre-storm conditions and become more anisotropic during the main phase. The quiet-time butterfly PADs can be observed on the nightside at L> 5.6. During the main phase, butterfly PADs have stronger 90 degrees-minima and can be observed at lower L-shells (down to L = 5), then transitioning into flat-top PADs at L similar to 4.5 - 5 and pancake PADs at L < 4.5. The resulting PAD coefficients for different energies, locations and storm epochs can be used to test the wave models and physics-based radiation belt codes in terms of pitch angle distributions.
KW - pitch angle
KW - pitch angle distributions
KW - electrons
KW - radiation belts
KW - magnetosphere
KW - van alien probes
Y1 - 2022
U6 - https://doi.org/10.3389/fspas.2022.836811
SN - 2296-987X
VL - 9
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Düvel, Pia
A1 - Ehmig, Ulrike
A1 - McCall, Jeremiah
A1 - Unceta Gómez, Luis
A1 - Bakogianni, Anastasia
A1 - Fischer, Jens
A1 - Serrano Lozano, David
A1 - Ambühl, Annemarie
A1 - Matz, Alicia
A1 - Brinker, Wolfram
A1 - Mach, Jonas Konstantin
A1 - Mancini, Mattia
A1 - Werner, Eva
ED - Ambühl, Annemarie
ED - Carlà-Uhink, Filippo
ED - Rollinger, Christian
ED - Walde, Christine
T1 - Spring Issue
T2 - thersites
KW - history textbooks
KW - textbook research
KW - historical consciousness
KW - Spartacus
KW - slavery
KW - history teaching
KW - Anfänge der systematischen lateinische Epigraphik
KW - Corpus Inscriptionum Latinarum
KW - Archiv
KW - Reproduktion von Inschriften
KW - history
KW - video games
KW - agents
KW - historiography
KW - Jonathan Muroya
KW - Greek mythology
KW - classical reception
KW - cartoons
Y1 - 2024
U6 - https://doi.org/10.34679/thersites.vol18
SN - 2364-7612
VL - 2024
IS - 18
ER -
TY - JOUR
A1 - Shprits, Yuri
A1 - Menietti, J. D.
A1 - Drozdov, Alexander
A1 - Horne, Richard B.
A1 - Woodfield, Emma E.
A1 - Groene, J. B.
A1 - de Soria-Santacruz, M.
A1 - Averkamp, T. F.
A1 - Garrett, H.
A1 - Paranicas, C.
A1 - Gurnett, Don A.
T1 - Strong whistler mode waves observed in the vicinity of Jupiter’s moons
JF - Nature Communications
N2 - Understanding of wave environments is critical for the understanding of how particles are accelerated and lost in space. This study shows that in the vicinity of Europa and Ganymede, that respectively have induced and internal magnetic fields, chorus wave power is significantly increased. The observed enhancements are persistent and exceed median values of wave activity by up to 6 orders of magnitude for Ganymede. Produced waves may have a pronounced effect on the acceleration and loss of particles in the Jovian magnetosphere and other astrophysical objects. The generated waves are capable of significantly modifying the energetic particle environment, accelerating particles to very high energies, or producing depletions in phase space density. Observations of Jupiter’s magnetosphere provide a unique opportunity to observe how objects with an internal magnetic field can interact with particles trapped in magnetic fields of larger scale objects.
Y1 - 2018
U6 - https://doi.org/10.1038/s41467-018-05431-x
SN - 2041-1723
VL - 9
PB - Nature Publ. Group
CY - London
ER -
TY - JOUR
A1 - Adolfs, Marjolijn
A1 - Hoque, Mohammed Mainul
A1 - Shprits, Yuri
T1 - Storm-time relative total electron content modelling using machine learning techniques
JF - Remote sensing
N2 - Accurately predicting total electron content (TEC) during geomagnetic storms is still a challenging task for ionospheric models. In this work, a neural-network (NN)-based model is proposed which predicts relative TEC with respect to the preceding 27-day median TEC, during storm time for the European region (with longitudes 30 degrees W-50 degrees E and latitudes 32.5 degrees N-70 degrees N). The 27-day median TEC (referred to as median TEC), latitude, longitude, universal time, storm time, solar radio flux index F10.7, global storm index SYM-H and geomagnetic activity index Hp30 are used as inputs and the output of the network is the relative TEC. The relative TEC can be converted to the actual TEC knowing the median TEC. The median TEC is calculated at each grid point over the European region considering data from the last 27 days before the storm using global ionosphere maps (GIMs) from international GNSS service (IGS) sources. A storm event is defined when the storm time disturbance index Dst drops below 50 nanotesla. The model was trained with storm-time relative TEC data from the time period of 1998 until 2019 (2015 is excluded) and contains 365 storms. Unseen storm data from 33 storm events during 2015 and 2020 were used to test the model. The UQRG GIMs were used because of their high temporal resolution (15 min) compared to other products from different analysis centers. The NN-based model predictions show the seasonal behavior of the storms including positive and negative storm phases during winter and summer, respectively, and show a mixture of both phases during equinoxes. The model's performance was also compared with the Neustrelitz TEC model (NTCM) and the NN-based quiet-time TEC model, both developed at the German Aerospace Agency (DLR). The storm model has a root mean squared error (RMSE) of 3.38 TEC units (TECU), which is an improvement by 1.87 TECU compared to the NTCM, where an RMSE of 5.25 TECU was found. This improvement corresponds to a performance increase by 35.6%. The storm-time model outperforms the quiet-time model by 1.34 TECU, which corresponds to a performance increase by 28.4% from 4.72 to 3.38 TECU. The quiet-time model was trained with Carrington averaged TEC and, therefore, is ideal to be used as an input instead of the GIM derived 27-day median. We found an improvement by 0.8 TECU which corresponds to a performance increase by 17% from 4.72 to 3.92 TECU for the storm-time model using the quiet-time-model predicted TEC as an input compared to solely using the quiet-time model.
KW - ionosphere
KW - relative total electron content
KW - geomagnetic storms
KW - neural
KW - networks
KW - NTCM
KW - European storm-time model
Y1 - 2022
U6 - https://doi.org/10.3390/rs14236155
SN - 2072-4292
VL - 14
IS - 23
PB - MDPI
CY - Basel
ER -
TY - BOOK
A1 - Garus, Marcel
A1 - Sawahn, Rohan
A1 - Wanke, Jonas
A1 - Tiedt, Clemens
A1 - Granzow, Clara
A1 - Kuffner, Tim
A1 - Rosenbaum, Jannis
A1 - Hagemann, Linus
A1 - Wollnik, Tom
A1 - Woth, Lorenz
A1 - Auringer, Felix
A1 - Kantusch, Tobias
A1 - Roth, Felix
A1 - Hanff, Konrad
A1 - Schilli, Niklas
A1 - Seibold, Leonard
A1 - Lindner, Marc Fabian
A1 - Raschack, Selina
ED - Grapentin, Andreas
ED - Tiedt, Clemens
ED - Polze, Andreas
T1 - Operating systems II - student projects
N2 - This technical report presents the results of student projects which were prepared during the lecture “Operating Systems II” offered by the “Operating Systems and Middleware” group at HPI in the Summer term of 2020. The lecture covered ad- vanced aspects of operating system implementation and architecture on topics such as Virtualization, File Systems and Input/Output Systems. In addition to attending the lecture, the participating students were encouraged to gather practical experience by completing a project on a closely related topic over the course of the semester. The results of 10 selected exceptional projects are covered in this report.
The students have completed hands-on projects on the topics of Operating System Design Concepts and Implementation, Hardware/Software Co-Design, Reverse Engineering, Quantum Computing, Static Source-Code Analysis, Operating Systems History, Application Binary Formats and more. It should be recognized that over the course of the semester all of these projects have achieved outstanding results which went far beyond the scope and the expec- tations of the lecture, and we would like to thank all participating students for their commitment and their effort in completing their respective projects, as well as their work on compiling this report.
N2 - Dieser technische Bericht beschriebt die Ergebnisse der Projekte, welche im Rahmen der Lehrveranstaltung "Betriebssysteme II" on teilnehmenden Studierenden durchgeführt wurden. Die Lehrveranstaltung wurde von der "Betriebssysteme und Middleware" am HPI im Sommersemester 2020 durchgeführt und behandele fortgeschrittene Aspekte der Betriebssystemarchitektur und -Implementierung am Beispiel der Virtualisierung, der Dateisysteme und der Eingabe/Ausgabe (I/O) Systeme. Zusätzlich zu den Vorlesungen wurden die Studierenden angeleitet, durch die Durchführung eines begleitenden Projekts praktische Erfahrungen im Umgang mit den behandelten Themen zu sammeln. Die Ergebnisse von 10 ausgewählten, herausragenden Projekten werden in diesem Report vorgestellt.
Die Studierenden haben unter anderem Projekte zu den Themen Betriebssystemdesign und -Implementierung, Hardware/Software Co-Design, Reverse Engineering, Quanten-Computing, Statische Quellcodeanalyse, Betriebssystemgeschichte, dem Binärformat von ausführbaren Dateien durchgeführt. Es ist anzuerkennen, dass alle teilnehmenden Studierenden im Verlauf des Semesters herausragende Ergebnisse erzielt haben, die weit über die Anforderungen der Lehrveranstaltung hinausgingen. Wir möchten uns bei allen teilnehmenden Studierenden für Ihren Einsatz bei der Durchführung der Projekte, sowie bei der Erstellung dieses Reports bedanken.
T3 - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam - 142
KW - operating systems
KW - network protocols
KW - software/hardware co-design
KW - static source-code analysis
KW - reverse engineering
KW - quantum computing
KW - Betriebssysteme
KW - Netzwerkprotokolle
KW - Software/Hardware Co-Design
KW - statische Quellcodeanalyse
KW - Reverse Engineering
KW - Quanten-Computing
Y1 - 2023
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-526363
SN - 978-3-86956-524-8
SN - 1613-5652
SN - 2191-1665
IS - 142
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - BOOK
A1 - Meinel, Christoph
A1 - Galbas, Michael
A1 - Hagebölling, David
T1 - Digitale Souveränität: Erkenntnisse aus dem deutschen Bildungssektor
T1 - Digital sovereignty: insights from Germany’s education sector
N2 - Digitale Technologien bieten erhebliche politische, wirtschaftliche und gesellschaftliche Chancen. Zugleich ist der Begriff digitale Souveränität zu einem Leitmotiv im deutschen Diskurs über digitale Technologien geworden: das heißt, die Fähigkeit des Staates, seine Verantwortung wahrzunehmen und die Befähigung der Gesellschaft – und des Einzelnen – sicherzustellen, die digitale Transformation selbstbestimmt zu gestalten. Exemplarisch für die Herausforderung in Deutschland und Europa, die Vorteile digitaler Technologien zu nutzen und gleichzeitig Souveränitätsbedenken zu berücksichtigen, steht der Bildungssektor. Er umfasst Bildung als zentrales öffentliches Gut, ein schnell aufkommendes Geschäftsfeld und wachsende Bestände an hochsensiblen personenbezogenen Daten. Davon ausgehend beschreibt der Bericht Wege zur Entschärfung des Spannungsverhältnisses zwischen Digitalisierung und Souveränität auf drei verschiedenen Ebenen – Staat, Wirtschaft und Individuum – anhand konkreter technischer Projekte im Bildungsbereich: die HPI Schul-Cloud (staatliche Souveränität), die MERLOT-Datenräume (wirtschaftliche Souveränität) und die openHPI-Plattform (individuelle Souveränität).
N2 - Digital technology offers significant political, economic, and societal opportunities. At the same time, the notion of digital sovereignty has become a leitmotif in German discourse: the state’s capacity to assume its responsibilities and safeguard society’s – and individuals’ – ability to shape the digital transformation in a self-determined way. The education sector is exemplary for the challenge faced by Germany, and indeed Europe, of harnessing the benefits of digital technology while navigating concerns around sovereignty. It encompasses education as a core public good, a rapidly growing field of business, and growing pools of highly sensitive personal data. The report describes pathways to mitigating the tension between digitalization and sovereignty at three different levels – state, economy, and individual – through the lens of concrete technical projects in the education sector: the HPI Schul-Cloud (state sovereignty), the MERLOT data spaces (economic sovereignty), and the openHPI platform (individual sovereignty).
T3 - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam - 156
KW - Digitalisierung
KW - digitale Souveränität
KW - digitale Bildung
KW - HPI Schul-Cloud
KW - MERLOT
KW - openHPI
KW - Europäische Union
KW - digitalization
KW - digital sovereignty
KW - digital education
KW - HPI Schul-Cloud
KW - MERLOT
KW - openHPI
KW - European Union
Y1 - 2023
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-595138
SN - 978-3-86956-560-6
SN - 1613-5652
SN - 2191-1665
IS - 156
SP - 1
EP - 29
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - BOOK
A1 - Meinel, Christoph
A1 - Galbas, Michael
A1 - Hagebölling, David
T1 - Digital sovereignty: insights from Germany’s education sector
T1 - Digitale Souveränität: Erkenntnisse aus dem deutschen Bildungssektor
N2 - Digital technology offers significant political, economic, and societal opportunities. At the same time, the notion of digital sovereignty has become a leitmotif in German discourse: the state’s capacity to assume its responsibilities and safeguard society’s – and individuals’ – ability to shape the digital transformation in a self-determined way. The education sector is exemplary for the challenge faced by Germany, and indeed Europe, of harnessing the benefits of digital technology while navigating concerns around sovereignty. It encompasses education as a core public good, a rapidly growing field of business, and growing pools of highly sensitive personal data. The report describes pathways to mitigating the tension between digitalization and sovereignty at three different levels – state, economy, and individual – through the lens of concrete technical projects in the education sector: the HPI Schul-Cloud (state sovereignty), the MERLOT data spaces (economic sovereignty), and the openHPI platform (individual sovereignty).
N2 - Digitale Technologien bieten erhebliche politische, wirtschaftliche und gesellschaftliche Chancen. Zugleich ist der Begriff digitale Souveränität zu einem Leitmotiv im deutschen Diskurs über digitale Technologien geworden: das heißt, die Fähigkeit des Staates, seine Verantwortung wahrzunehmen und die Befähigung der Gesellschaft – und des Einzelnen – sicherzustellen, die digitale Transformation selbstbestimmt zu gestalten. Exemplarisch für die Herausforderung in Deutschland und Europa, die Vorteile digitaler Technologien zu nutzen und gleichzeitig Souveränitätsbedenken zu berücksichtigen, steht der Bildungssektor. Er umfasst Bildung als zentrales öffentliches Gut, ein schnell aufkommendes Geschäftsfeld und wachsende Bestände an hochsensiblen personenbezogenen Daten. Davon ausgehend beschreibt der Bericht Wege zur Entschärfung des Spannungsverhältnisses zwischen Digitalisierung und Souveränität auf drei verschiedenen Ebenen – Staat, Wirtschaft und Individuum – anhand konkreter technischer Projekte im Bildungsbereich: die HPI Schul-Cloud (staatliche Souveränität), die MERLOT-Datenräume (wirtschaftliche Souveränität) und die openHPI-Plattform (individuelle Souveränität).
T3 - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam - 157
KW - digitalization
KW - digital sovereignty
KW - digital education
KW - HPI Schul-Cloud
KW - MERLOT
KW - openHPI
KW - European Union
KW - Digitalisierung
KW - digitale Souveränität
KW - digitale Bildung
KW - HPI Schul-Cloud
KW - MERLOT
KW - openHPI
KW - Europäische Union
Y1 - 2023
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-597723
SN - 978-3-86956-561-3
SN - 1613-5652
SN - 2191-1665
IS - 157
SP - 1
EP - 27
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - JOUR
A1 - Zwickel, Theresa
A1 - Kahl, Sandra
A1 - Rychlik, Michael
A1 - Müller, Marina E. H.
T1 - Chemotaxonomy of Mycotoxigenic Small-Spored Alternaria Fungi
BT - Do Multitoxin Mixtures Act as an Indicator for Species Differentiation?
JF - Frontiers in microbiology
N2 - Necrotrophic as well as saprophytic small-spored Altemaria (A.) species are annually responsible for major losses of agricultural products, such as cereal crops, associated with the contamination of food and feedstuff with potential health-endangering Altemaria toxins. Knowledge of the metabolic capabilities of different species-groups to form mycotoxins is of importance for a reliable risk assessment. 93 Altemaria strains belonging to the four species groups Alternaria tenuissima, A. arborescens, A. altemata, and A. infectoria were isolated from winter wheat kernels harvested from fields in Germany and Russia and incubated under equal conditions. Chemical analysis by means of an HPLC-MS/MS multi-Alternaria-toxin-method showed that 95% of all strains were able to form at least one of the targeted 17 non-host specific Altemaria toxins. Simultaneous production of up to 15 (modified) Altemaria toxins by members of the A. tenuissima, A. arborescens, A. altemata species-groups and up to seven toxins by A. infectoria strains was demonstrated. Overall tenuazonic acid was the most extensively formed mycotoxin followed by alternariol and alternariol mono methylether, whereas altertoxin I was the most frequently detected toxin. Sulfoconjugated modifications of alternariol, alternariol mono methylether, altenuisol and altenuene were frequently determined. Unknown perylene quinone derivatives were additionally detected. Strains of the species-group A. infectoria could be segregated from strains of the other three species-groups due to significantly lower toxin levels and the specific production of infectopyrone. Apart from infectopyrone, alterperylenol was also frequently produced by 95% of the A. infectoria strains. Neither by the concentration nor by the composition of the targeted Altemaria toxins a differentiation between the species-groups A. altemata, A. tenuissima and A. arborescens was possible.
KW - small-spored Alternaria fungi
KW - Alternaria species-groups
KW - Alternaria mycotoxins
KW - chemotaxonomy
KW - secondary metabolite profiling
KW - LC-MS/MS
KW - wheat
KW - perylene quinone derivatives
Y1 - 2018
U6 - https://doi.org/10.3389/fmicb.2018.01368
SN - 1664-302X
VL - 9
PB - Frontiers Research Foundation
CY - Lausanne
ER -
TY - JOUR
A1 - Ette, Ottmar
A1 - Schwarz, Ingo
A1 - Gao, Hong
A1 - Kraft, Tobias
A1 - Kutzinski, Vera
A1 - Zielnica, Krzysztof
ED - Ette, Ottmar
ED - Knobloch, Eberhard
T1 - HiN : Alexander von Humboldt im Netz
N2 - -Ottmar Ette, Ingo Schwarz: „Ein junges, neues Geschlecht wird besseres liefern als das alte“. Ein Empfehlungsbrief Alexander von Humboldts für Carl Ludwig
-GAO Hong: Nachgedanken zur Übersetzung des ersten Bandes von Humboldts Kosmos
-Tobias Kraft: Neue Quellen zu Humboldts Kuba-Forschung. Das „Digitale Dossier“ des Proyecto Humboldt Digital (2019 – 2023)
-Vera Kutzinski: Off-Road Adventures: Reading Statistics in Alexander von Humboldt’s Political Essay on the Kingdom of New Spain
-Krzysztof Zielnica: Alexander von Humboldt und Polen – zum 150. Jahrestag seiner Reise nach Warschau. Mit einleitenden Worten von Ingo Schwarz
T3 - HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies - 48
KW - Alexander von Humboldt
KW - Förderung junger Wissenschaftler
KW - Carl Ludwig
KW - Emil du Bois-Reymond
KW - Kurhessen
KW - Bernhard Eberhard
KW - Physiologie
KW - Kosmos
KW - Zusammenhänge der Naturerscheinungen und deren Wechselwirkungen auf einander
KW - Ehrfurcht vor Kosmos
KW - architektonische Schönheit der Humboldt’schen Sprache
KW - digitale Geisteswissenschaften
KW - Kuba
KW - Editionsphilologie
KW - Humboldt-Nachlass
KW - Essai politique sur l'île de Cuba
KW - statistics
KW - visuality and narrative
KW - word-image relations
KW - New Spain
KW - Verhältnis zu Polen
KW - Ehrenmitglied der Warschauer Gesellschaft der Freunde der Wissenschaften
KW - Julian Ursyn Niemcewicz
KW - Nikolaus I.
KW - Kaiser von Russland und König von Polen (Kongresspolen)
Y1 - 2024
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-633524
SN - 2568-3543
SN - 1617-5239
VL - XXV
IS - 48
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - JOUR
A1 - Landis, Daji August
A1 - Saikin, Anthony
A1 - Zhelavskaya, Irina
A1 - Drozdov, Alexander
A1 - Aseev, Nikita
A1 - Shprits, Yuri
A1 - Pfitzer, Maximilian F.
A1 - Smirnov, Artem G.
T1 - NARX Neural Network Derivations of the Outer Boundary Radiation Belt Electron Flux
JF - Space Weather: the international journal of research and applications
N2 - We present two new empirical models of radiation belt electron flux at geostationary orbit. GOES-15 measurements of 0.8 MeV electrons were used to train a Nonlinear Autoregressive with Exogenous input (NARX) neural network for both modeling GOES-15 flux values and an upper boundary condition scaling factor (BF). The GOES-15 flux model utilizes an input and feedback delay of 2 and 2 time steps (i.e., 5 min time steps) with the most efficient number of hidden layers set to 10. Magnetic local time, Dst, Kp, solar wind dynamic pressure, AE, and solar wind velocity were found to perform as predicative indicators of GOES-15 flux and therefore were used as the exogenous inputs. The NARX-derived upper boundary condition scaling factor was used in conjunction with the Versatile Electron Radiation Belt (VERB) code to produce reconstructions of the radiation belts during the period of July-November 1990, independent of in-situ observations. Here, Kp was chosen as the sole exogenous input to be more compatible with the VERB code. This Combined Release and Radiation Effects Satellite-era reconstruction showcases the potential to use these neural network-derived boundary conditions as a method of hindcasting the historical radiation belts. This study serves as a companion paper to another recently published study on reconstructing the radiation belts during Solar Cycles 17-24 (Saikin et al., 2021, ), for which the results featured in this paper were used.
KW - radiation belts
KW - forecasting (1922, 4315, 7924, 7964)
KW - machine learning (0555)
Y1 - 2022
U6 - https://doi.org/10.1029/2021SW002774
SN - 1542-7390
VL - 20
IS - 5
PB - American Geophysical Union
CY - Washington
ER -
TY - JOUR
A1 - Prol, Fabricio S.
A1 - Smirnov, Artem G.
A1 - Hoque, M. Mainul
A1 - Shprits, Yuri
T1 - Combined model of topside ionosphere and plasmasphere derived from radio-occultation and Van Allen Probes data
JF - Scientific reports
N2 - In the last years, electron density profile functions characterized by a linear dependence on the scale height showed good results when approximating the topside ionosphere. The performance above 800 km, however, is not yet well investigated.
This study investigates the capability of the semi-Epstein functions to represent electron density profiles from the peak height up to 20,000 km. Electron density observations recorded by the Van Allen Probes were used to resolve the scale height dependence in the plasmasphere.
It was found that the linear dependence of the scale height in the topside ionosphere cannot be directly used to extrapolate profiles above 800 km.
We find that the dependence of scale heights on altitude is quadratic in the plasmasphere. A statistical model of the scale heights is therefore proposed. After combining the topside ionosphere and plasmasphere by a unified model, we have obtained good estimations not only in the profile shapes, but also in the Total Electron Content magnitude and distributions when compared to actual measurements from 2013, 2014, 2016 and 2017.
Our investigation shows that Van Allen Probes can be merged to radio-occultation data to properly represent the upper ionosphere and plasmasphere by means of a semi-Epstein function.
Y1 - 2022
U6 - https://doi.org/10.1038/s41598-022-13302-1
SN - 2045-2322
VL - 12
IS - 1
PB - Macmillan Publishers Limited, part of Springer Nature
CY - London
ER -
TY - JOUR
A1 - Haas, Bernhard
A1 - Shprits, Yuri
A1 - Allison, Hayley
A1 - Wutzig, Michael
A1 - Wang, Dedong
T1 - Which parameter controls ring current electron dynamics
JF - Frontiers in astronomy and space sciences
N2 - Predicting the electron population of Earth's ring current during geomagnetic storms still remains a challenging task.
In this work, we investigate the sensitivity of 10 keV ring current electrons to different driving processes, parameterised by the Kp index, during several moderate and intense storms.
Results are validated against measurements from the Van Allen Probes satellites. Perturbing the Kp index allows us to identify the most dominant processes for moderate and intense storms respectively.
We find that during moderate storms (Kp < 6) the drift velocities mostly control the behaviour of low energy electrons, while loss from wave-particle interactions is the most critical parameter for quantifying the evolution of intense storms (Kp > 6). Perturbations of the Kp index used to drive the boundary conditions at GEO and set the plasmapause location only show a minimal effect on simulation results over a limited L range.
It is further shown that the flux at L & SIM; 3 is more sensitive to changes in the Kp index compared to higher L shells, making it a good proxy for validating the source-loss balance of a ring current model.
KW - ring current
KW - magnetosphere
KW - electron lifetimes
KW - electrons
KW - van allen probes (RBSP)
KW - ring current model
KW - verb
Y1 - 2022
U6 - https://doi.org/10.3389/fspas.2022.911002
SN - 2296-987X
VL - 9
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Kühne, Franziska
A1 - Paunov, Tatjana
A1 - Weck, Florian
T1 - Recognizing obsessive-compulsive disorder
BT - How suitable is the German Zohar-Fineberg obsessive-compulsive screen?
JF - BMC psychiatry
N2 - Background
Despite the prevalence of obsessive-compulsive disorder (OCD), its precise identification remains challenging. With the Zohar-Fineberg Obsessive-Compulsive Screen (ZF-OCS; 5 or 6 items), a brief instrument is widely available mainly in English. As there is a lack of empirical studies on the ZF-OCS, the aim of the present study was to translate the items into German and investigate the instrument in a nonclinical sample.
Methods
In two consecutive online surveys, n = 304 and n = 51 students participated. Besides the ZF-OCS, they answered established measures on OCD, depression, health anxiety, general anxiety and health-related well-being.
Results
Whereas internal consistency was low (α = .53–.72; ω = .55–.69), retest reliability (rt1,t2 = .89) at two weeks was high. As expected, we found high correlations with other OCD instruments (r > .61; convergent validity), and significantly weaker correlations with measures of depression (r = .39), health anxiety (r = .29), and health-related well-being (r = −.28, divergent validity). Nonetheless, the correlations with general anxiety were somewhere in between (r = .52).
Conclusions
Due to heterogeneous OCD subtypes, the ZF-OCS asks diverse questions which probably resulted in the present internal consistency. Nevertheless, the results on retest reliability and validity were promising. As for other OCD instruments, divergent validity regarding general anxiety seems problematic to establish. Even so, the ZF-OCS seems valuable for screening purposes, as it is short and easy to administer, and may facilitate initiating subsequent clinical assessment. Further studies should determine the instrument’s diagnostic accuracy.
KW - Obsessive-compulsive disorder
KW - Psychodiagnostics
KW - Psychometric properties
KW - Screening
Y1 - 2021
U6 - https://doi.org/10.1186/s12888-021-03458-x
SN - 1471-244X
VL - 21
PB - Springer Nature
CY - London
ER -
TY - JOUR
A1 - Bornhorst, Dorothee
A1 - Seyfried, Salim
T1 - Strong as a hippo’s heart
BT - Biomechanical hippo signaling during zebrafish cardiac development
JF - Frontiers in cell and developmental biology
N2 - The heart is comprised of multiple tissues that contribute to its physiological functions. During development, the growth of myocardium and endocardium is coupled and morphogenetic processes within these separate tissue layers are integrated. Here, we discuss the roles of mechanosensitive Hippo signaling in growth and morphogenesis of the zebrafish heart. Hippo signaling is involved in defining numbers of cardiac progenitor cells derived from the secondary heart field, in restricting the growth of the epicardium, and in guiding trabeculation and outflow tract formation. Recent work also shows that myocardial chamber dimensions serve as a blueprint for Hippo signaling-dependent growth of the endocardium. Evidently, Hippo pathway components act at the crossroads of various signaling pathways involved in embryonic zebrafish heart development. Elucidating how biomechanical Hippo signaling guides heart morphogenesis has direct implications for our understanding of cardiac physiology and pathophysiology.
KW - Hippo signaling
KW - Yap1/Wwtr1 (Taz)
KW - cardiac development
KW - mechanobiology
KW - endocardium
KW - myocardium
KW - zebrafish
KW - intra-organ-communication
Y1 - 2021
U6 - https://doi.org/10.3389/fcell.2021.731101
SN - 2296-634X
VL - 9
SP - 1
EP - 10
PB - Frontiers Media
CY - Lausanne, Schweiz
ER -
TY - JOUR
A1 - Szangolies, Leonna
A1 - Rohwäder, Marie-Sophie
A1 - Jeltsch, Florian
T1 - Single large AND several small habitat patches
BT - a community perspective on their importance for biodiversity
JF - Basic and applied ecology : Journal of the Gesellschaft für Ökologie
N2 - The debate whether single large or several small (SLOSS) patches benefit biodiversity has existed for decades, but recent literature provides increasing evidence for the importance of small habitats.
Possible beneficial mechanisms include reduced presence of preda-tors and competitors in small habitat areas or specific functions such as stepping stones for dispersal.
Given the increasing amount of studies highlighting individual behavioral differences that may influence these functions, we hypothesize that the advantage of small versus large habitat patches not only depends on patch functionality but also on the presence of animal personalities (i.e., risk-tolerant vs. risk-averse). Using an individual-based, spatially-explicit community model, we analyzed the diversity of mammal communities in landscapes consisting of a few large habitat islands interspersed with different amounts and sizes of small habitat patches.
Within these heterogeneous environments, individuals compete for resources and form home-ranges, with only risk-tolerant individuals using habitat edges. Results show that when risk-tolerant individuals exist, small patches increase species diversity. A strong peak occurs at approximately 20% habitat cover in small patches when those small habitats are only used for foraging but not for breeding and home-range core position. Additional usage as stepping stones for juvenile dispersal further increases species persistence. Over-all, our results reveal that a combination of a few large and several small habitat patches promotes biodiversity by enhancing land-scape heterogeneity.
Here, heterogeneity is created by pronounced differences in habitat functionality, increasing edge density, and variability in habitat use by different behavioral types. The finding that a combination of single large AND several small (SLASS) patches is needed for effective biodiversity preservation has implications for advancing landscape conservation.
Particularly in struc-turally poor agricultural areas, modern technology enables precise management with the opportunity to create small foraging habitats by excluding less profitable agricultural land from cultivation.
KW - SLOSS
KW - fragmentation
KW - heterogeneity
KW - community
KW - coexistence
KW - coviability
KW - competition
KW - home-ranges
KW - inter-individual difference
KW - personality
Y1 - 2022
U6 - https://doi.org/10.1016/j.baae.2022.09.004
SN - 1439-1791
SN - 1618-0089
VL - 65
SP - 16
EP - 27
PB - Elsevier
CY - München
ER -
TY - JOUR
A1 - Küken, Anika
A1 - Treves, Haim
A1 - Nikoloski, Zoran
T1 - A simulation-free constrained regression approach for flux estimation in isotopically nonstationary metabolic flux analysis with applications in microalgae
JF - Frontiers in plant science : FPLS
N2 - Introduction Flux phenotypes from different organisms and growth conditions allow better understanding of differential metabolic networks functions. Fluxes of metabolic reactions represent the integrated outcome of transcription, translation, and post-translational modifications, and directly affect growth and fitness. However, fluxes of intracellular metabolic reactions cannot be directly measured, but are estimated via metabolic flux analysis (MFA) that integrates data on isotope labeling patterns of metabolites with metabolic models. While the application of metabolomics technologies in photosynthetic organisms have resulted in unprecedented data from 13CO2-labeling experiments, the bottleneck in flux estimation remains the application of isotopically nonstationary MFA (INST-MFA). INST-MFA entails fitting a (large) system of coupled ordinary differential equations, with metabolite pools and reaction fluxes as parameters. Here, we focus on the Calvin-Benson cycle (CBC) as a key pathway for carbon fixation in photosynthesizing organisms and ask if approaches other than classical INST-MFA can provide reliable estimation of fluxes for reactions comprising this pathway.
Methods First, we show that flux estimation with the labeling patterns of all CBC intermediates can be formulated as a single constrained regression problem, avoiding the need for repeated simulation of time-resolved labeling patterns.
Results We then compare the flux estimates of the simulation-free constrained regression approach with those obtained from the classical INST-MFA based on labeling patterns of metabolites from the microalgae Chlamydomonas reinhardtii, Chlorella sorokiniana and Chlorella ohadii under different growth conditions.
Discussion Our findings indicate that, in data-rich scenarios, simulation-free regression-based approaches provide a suitable alternative for flux estimation from classical INST-MFA since we observe a high qualitative agreement (rs=0.89) to predictions obtained from INCA, a state-of-the-art tool for INST-MFA.
KW - metabolic flux analysis
KW - INST-MFA
KW - regression
KW - 13C labeling
KW - algae
Y1 - 2023
U6 - https://doi.org/10.3389/fpls.2023.1140829
SN - 1664-462X
VL - 14
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Puchkov, Dmytro
A1 - Müller, Paul Markus
A1 - Lehmann, Martin
A1 - Matthäus, Claudia
T1 - Analyzing the cellular plasma membrane by fast and efficient correlative STED and platinum replica EM
JF - Frontiers in cell and developmental biology
N2 - The plasma membrane of mammalian cells links transmembrane receptors, various structural components, and membrane-binding proteins to subcellular processes, allowing inter- and intracellular communication. Therefore, membrane-binding proteins, together with structural components such as actin filaments, modulate the cell membrane in their flexibility, stiffness, and curvature. Investigating membrane components and curvature in cells remains challenging due to the diffraction limit in light microscopy. Preparation of 5–15-nm-thin plasma membrane sheets and subsequent inspection by metal replica transmission electron microscopy (TEM) reveal detailed information about the cellular membrane topology, including the structure and curvature. However, electron microscopy cannot identify proteins associated with specific plasma membrane domains. Here, we describe a novel adaptation of correlative super-resolution light microscopy and platinum replica TEM (CLEM-PREM), allowing the analysis of plasma membrane sheets with respect to their structural details, curvature, and associated protein composition. We suggest a number of shortcuts and troubleshooting solutions to contemporary PREM protocols. Thus, implementation of super-resolution stimulated emission depletion (STED) microscopy offers significant reduction in sample preparation time and reduced technical challenges for imaging and analysis. Additionally, highly technical challenges associated with replica preparation and transfer on a TEM grid can be overcome by scanning electron microscopy (SEM) imaging. The combination of STED microscopy and platinum replica SEM or TEM provides the highest spatial resolution of plasma membrane proteins and their underlying membrane and is, therefore, a suitable method to study cellular events like endocytosis, membrane trafficking, or membrane tension adaptations.
KW - plasma membrane
KW - endocytosis
KW - CLEM
KW - STED
KW - TEM
KW - SEM
KW - electron microscopy
Y1 - 2023
U6 - https://doi.org/10.3389/fcell.2023.1305680
SN - 2296-634X
VL - 11
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Wojcik, Laurie Anne Myriam
A1 - Ceulemans, Ruben
A1 - Gaedke, Ursula
T1 - Functional diversity buffers the effects of a pulse perturbation on the dynamics of tritrophic food webs
JF - Ecology and Evolution
N2 - Biodiversity decline causes a loss of functional diversity, which threatens ecosystems through a dangerous feedback loop: This loss may hamper ecosystems’ ability to buffer environmental changes, leading to further biodiversity losses. In this context, the increasing frequency of human-induced excessive loading of nutrients causes major problems in aquatic systems. Previous studies investigating how functional diversity influences the response of food webs to disturbances have mainly considered systems with at most two functionally diverse trophic levels. We investigated the effects of functional diversity on the robustness, that is, resistance, resilience, and elasticity, using a tritrophic—and thus more realistic—plankton food web model. We compared a non-adaptive food chain with no diversity within the individual trophic levels to a more diverse food web with three adaptive trophic levels. The species fitness differences were balanced through trade-offs between defense/growth rate for prey and selectivity/half-saturation constant for predators. We showed that the resistance, resilience, and elasticity of tritrophic food webs decreased with larger perturbation sizes and depended on the state of the system when the perturbation occurred. Importantly, we found that a more diverse food web was generally more resistant and resilient but its elasticity was context-dependent. Particularly, functional diversity reduced the probability of a regime shift toward a non-desirable alternative state. The basal-intermediate interaction consistently determined the robustness against a nutrient pulse despite the complex influence of the shape and type of the dynamical attractors. This relationship was strongly influenced by the diversity present and the third trophic level. Overall, using a food web model of realistic complexity, this study confirms the destructive potential of the positive feedback loop between biodiversity loss and robustness, by uncovering mechanisms leading to a decrease in resistance, resilience, and potentially elasticity as functional diversity declines.
KW - functional diversity
KW - nutrient spike
KW - pulse perturbation
KW - regime shift
KW - robustness
KW - tritrophic food web
Y1 - 2021
U6 - https://doi.org/10.1002/ece3.8214
SN - 2045-7758
N1 - Wojcik and Ceulemans shared first authorship.
VL - 11
IS - 22
SP - 15639
EP - 15663
PB - John Wiley & Sons, Inc.
CY - Hoboken (New Jersey)
ER -
TY - GEN
A1 - Krause, Werner
T1 - Die Macht der Sonntagsfrage
T2 - Verfassungsblog : on matters constitutional
N2 - Für das Jahr 2024 sind entscheidende Wahlen geplant – unter ihnen die
US-Präsidentschaftswahl und die Wahlen zum Europäischen Parlament. In
Deutschland werden in Brandenburg, Sachsen und Thüringen die Landtage
gewählt. Wahlumfragen, insbesondere die Sonntagsfrage, sind zu einem
integralen Bestandteil von Wahlkämpfen geworden; gleichzeitig steht auch
deren Zuverlässigkeit im Zentrum medialer Aufmerksamkeit. Eine Debatte über
die Kommunikation und Darstellung von Meinungsumfragen ist in Deutschland
dringend notwendig. Eine bindende Selbstverpflichtung der Umfrageinstitute und
Medienhäuser wäre eine vielversprechende Lösung.
Y1 - 2023
U6 - https://doi.org/10.17176/20231222-111226-0
SN - 2366-7044
PB - Max Steinbeis Verfassungsblog gGmbH
CY - Berlin
ER -
TY - CHAP
A1 - Schladebach, Marcus
ED - Gräfe, Hans-Christian
T1 - Satelliten-Megakonstellationen im Weltraumrecht
T2 - Tagungsband zur Sommerkonferenz 2022 : Telemedicus – Recht der Informationsgesellschaft
Y1 - 2022
UR - https://rainermuehlhoff.de/media/publications/telemedicus-2022-tagungsband-isbn-978-3-8005-1857-9.pdf
SN - 978-3-8005-1857-9
VL - 6
SP - 68
EP - 75
PB - Fachmedien Recht und Wirtschaft, dfv Mediengruppe
CY - Frankfurt am Main
ER -
TY - GEN
A1 - El Mahmoud, Khaled
T1 - ‘Steadfast and unreserved’
BT - is Germany in breach of its obligation to ensure respect for international humanitarian law?
T2 - Verfassungsblog : on matters constitutional
Y1 - 2023
U6 - https://doi.org/10.59704/b01ead5567535025
SN - 2366-7044
PB - Max Steinbeis Verfassungsblog gGmbH
CY - Berlin
ER -
TY - JOUR
A1 - Aktas, Berfin
A1 - Stede, Manfred
T1 - Anaphoric distance in oral and written language
BT - Experimental evidence
JF - Discours : revue de linguistique, psycholinguistique et informatique
N2 - We investigate the variation in oral and written language in terms of anaphoric distance (i.e., the textual distance between anaphors and their antecedents), expanding corpus-based research with experimental evidence.
Contrastive corpus studies demonstrate that oral genres include longer average anaphoric distance than written genres, if the distance is measured in terms of clauses (Fox, 1987; Aktas & Stede, 2020).
We designed an experiment in order to examine the contrasts in oral and written mediums, using the same genre.
We aim to gain more insight about the impact of the medium, in a situation where both mediums convey a similar level of spontaneity, informality and interactivity. We designed a story continuation study, where the participants are recruited via crowdsourcing.
To our knowledge, this is the first study of its kind, where anaphoric distance is manipulated systematically in a language production experiment in order to examine medium distinctions.
We observed that participants use more pronouns in oral medium than in written medium if the anaphoric distance is long.
This result is in line with the implications of the earlier corpus-based research. In addition, our results indicate that anaphoric distance has a larger effect in referential choice for the written medium.
KW - anaphora
KW - anaphoric distance
KW - referential choice
KW - production medium
KW - oral
KW - written
KW - story continuation
KW - crowdsourcing
Y1 - 2022
U6 - https://doi.org/10.4000/discours.12383
SN - 1963-1723
IS - 31
PB - Université de Paris-Sorbonne, Maion Recherche
CY - Paris
ER -
TY - GEN
A1 - Ambos, Kai
A1 - Bock, Stefanie
A1 - Geneuss, Julia
A1 - Jeßberger, Florian
A1 - Kreß, Claus
A1 - Oeter, Stefan
A1 - Paulus, Andreas
A1 - Talmon, Stefan
A1 - Zimmermann, Andreas
T1 - Without fear or favour
BT - for an effective international criminal court
T2 - Verfassungsblog : on matters constitutional
Y1 - 2024
U6 - https://doi.org/10.59704/eea458648230c9df
SN - 2366-7044
PB - Max Steinbeis Verfassungsblog gGmbH
CY - Berlin
ER -
TY - GEN
A1 - Koethke, Kira
T1 - Forschungsfreiheit im Strafprozess
T2 - Verfassungsblog : on matters constitutional
KW - Beschlagnahme
KW - Deutschland
KW - Forschungsfreiheit
KW - Strafverfahren
KW - Wissenschaftsfreiheit
KW - Zeugnisverweigerungsrecht
Y1 - 2023
U6 - https://doi.org/10.59704/1e5535e98d06a19b
SN - 2366-7044
PB - Max Steinbeis Verfassungsblog gGmbH
CY - Berlin
ER -
TY - JOUR
A1 - Gutzeit, Lilly Joan
A1 - Tiberius, Victor
T1 - Business and management research on the motion picture industry
BT - a bibliometric analysis
JF - Journalism and media
N2 - The motion picture industry is subject to extensive business and management research conducted on a wide range of topics. Due to high research productivity, it is challenging to keep track of the abundance of publications. Against this background, we employ a bibliographic coupling analysis to gain a comprehensive understanding of current research topics. The following themes were defined: Key factors for success, word of mouth and social media, organizational and pedagogical dimensions, advertising—product placement and online marketing, tourism, the influence of data, the influence of culture, revenue maximization and purchase decisions, and the perception and identification of audiences. Based on the cluster analysis, we suggest the following future research opportunities: Exploring technological innovations, especially the influence of social media and streaming platforms in the film industry; the in-depth analysis of the use of artificial intelligence in film production, both in terms of its creative potential and ethical and legal challenges; the exploration of the representation of wokeness and minorities in films and their cultural and economic significance; and, finally, a detailed examination of the long-term effects of the COVID-19 pandemic and other crises on the film industry, especially in terms of changed consumption habits and structural adjustments.
KW - bibliometric analysis
KW - business researc
KW - films
KW - movies
KW - literature review
KW - motion pictures
Y1 - 2023
U6 - https://doi.org/10.3390/journalmedia4040076
SN - 2673-5172
VL - 4
IS - 4
SP - 1198
EP - 1210
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Kuhlmann, Sabine
A1 - Franzke, Jochen
A1 - Peters, Niklas
A1 - Dumas, Benoît Paul
T1 - Institutional designs and dynamics of crisis governance at the local level
BT - European governments facing the polycrisis
JF - Policy design and practice
N2 - This article analyses the institutional design variants of local crisis governance responses to the COVID-19 pandemic and their entanglement with other locally impactful crises from a cross-country comparative perspective (France, Germany, Poland, Sweden, and the UK/England). The pandemic offers an excellent empirical lens for scrutinizing the phenomenon of polycrises governance because it occurred while European countries were struggling with the impacts of several prior, ongoing, or newly arrived crises. Our major focus is on institutional design variants of crisis governance (dependent variable) and the influence of different administrative cultures on it (independent variable). Furthermore, we analyze the entanglement and interaction of institutional responses to other (previous or parallel) crises (polycrisis dynamics). Our findings reveal a huge variance of institutional designs, largely evoked by country-specific administrative cultures and profiles. The degree of de-/centralization and the intensity of coordination or decoupling across levels of government differs significantly by country. Simultaneously, all countries were affected by interrelated and entangled crises, resulting in various patterns of polycrisis dynamics. While policy failures and “fatal remedies” from previous crises have partially impaired the resilience and crisis preparedness of local governments, we have also found some learning effects from previous crises.
KW - polycrisis
KW - pandemic
KW - local government
KW - intergovernmental relations
KW - public administration
KW - crisis management
KW - Germany
KW - France
KW - Poland
KW - Sweden
KW - United Kingdom
Y1 - 2024
U6 - https://doi.org/10.1080/25741292.2024.2344784
SN - 2574-1292
SP - 1
EP - 21
PB - Taylor & Francis
CY - London
ER -
TY - BOOK
A1 - Kuban, Robert
A1 - Rotta, Randolf
A1 - Nolte, Jörg
A1 - Chromik, Jonas
A1 - Beilharz, Jossekin Jakob
A1 - Pirl, Lukas
A1 - Friedrich, Tobias
A1 - Lenzner, Pascal
A1 - Weyand, Christopher
A1 - Juiz, Carlos
A1 - Bermejo, Belen
A1 - Sauer, Joao
A1 - Coelh, Leandro dos Santos
A1 - Najafi, Pejman
A1 - Pünter, Wenzel
A1 - Cheng, Feng
A1 - Meinel, Christoph
A1 - Sidorova, Julia
A1 - Lundberg, Lars
A1 - Vogel, Thomas
A1 - Tran, Chinh
A1 - Moser, Irene
A1 - Grunske, Lars
A1 - Elsaid, Mohamed Esameldin Mohamed
A1 - Abbas, Hazem M.
A1 - Rula, Anisa
A1 - Sejdiu, Gezim
A1 - Maurino, Andrea
A1 - Schmidt, Christopher
A1 - Hügle, Johannes
A1 - Uflacker, Matthias
A1 - Nozza, Debora
A1 - Messina, Enza
A1 - Hoorn, André van
A1 - Frank, Markus
A1 - Schulz, Henning
A1 - Alhosseini Almodarresi Yasin, Seyed Ali
A1 - Nowicki, Marek
A1 - Muite, Benson K.
A1 - Boysan, Mehmet Can
A1 - Bianchi, Federico
A1 - Cremaschi, Marco
A1 - Moussa, Rim
A1 - Abdel-Karim, Benjamin M.
A1 - Pfeuffer, Nicolas
A1 - Hinz, Oliver
A1 - Plauth, Max
A1 - Polze, Andreas
A1 - Huo, Da
A1 - Melo, Gerard de
A1 - Mendes Soares, Fábio
A1 - Oliveira, Roberto Célio Limão de
A1 - Benson, Lawrence
A1 - Paul, Fabian
A1 - Werling, Christian
A1 - Windheuser, Fabian
A1 - Stojanovic, Dragan
A1 - Djordjevic, Igor
A1 - Stojanovic, Natalija
A1 - Stojnev Ilic, Aleksandra
A1 - Weidmann, Vera
A1 - Lowitzki, Leon
A1 - Wagner, Markus
A1 - Ifa, Abdessatar Ben
A1 - Arlos, Patrik
A1 - Megia, Ana
A1 - Vendrell, Joan
A1 - Pfitzner, Bjarne
A1 - Redondo, Alberto
A1 - Ríos Insua, David
A1 - Albert, Justin Amadeus
A1 - Zhou, Lin
A1 - Arnrich, Bert
A1 - Szabó, Ildikó
A1 - Fodor, Szabina
A1 - Ternai, Katalin
A1 - Bhowmik, Rajarshi
A1 - Campero Durand, Gabriel
A1 - Shevchenko, Pavlo
A1 - Malysheva, Milena
A1 - Prymak, Ivan
A1 - Saake, Gunter
ED - Meinel, Christoph
ED - Polze, Andreas
ED - Beins, Karsten
ED - Strotmann, Rolf
ED - Seibold, Ulrich
ED - Rödszus, Kurt
ED - Müller, Jürgen
T1 - HPI Future SOC Lab – Proceedings 2019
N2 - The “HPI Future SOC Lab” is a cooperation of the Hasso Plattner Institute (HPI) and industry partners. Its mission is to enable and promote exchange and interaction between the research community and the industry partners.
The HPI Future SOC Lab provides researchers with free of charge access to a complete infrastructure of state of the art hard and software. This infrastructure includes components, which might be too expensive for an ordinary research environment, such as servers with up to 64 cores and 2 TB main memory. The offerings address researchers particularly from but not limited to the areas of computer science and business information systems. Main areas of research include cloud computing, parallelization, and In-Memory technologies.
This technical report presents results of research projects executed in 2019. Selected projects have presented their results on April 9th and November 12th 2019 at the Future SOC Lab Day events.
N2 - Das Future SOC Lab am HPI ist eine Kooperation des Hasso-Plattner-Instituts mit verschiedenen Industriepartnern. Seine Aufgabe ist die Ermöglichung und Förderung des Austausches zwischen Forschungsgemeinschaft und Industrie.
Am Lab wird interessierten Wissenschaftlern eine Infrastruktur von neuester Hard- und Software kostenfrei für Forschungszwecke zur Verfügung gestellt. Dazu zählen teilweise noch nicht am Markt verfügbare Technologien, die im normalen Hochschulbereich in der Regel nicht zu finanzieren wären, bspw. Server mit bis zu 64 Cores und 2 TB Hauptspeicher. Diese Angebote richten sich insbesondere an Wissenschaftler in den Gebieten Informatik und Wirtschaftsinformatik. Einige der Schwerpunkte sind Cloud Computing, Parallelisierung und In-Memory Technologien.
In diesem Technischen Bericht werden die Ergebnisse der Forschungsprojekte des Jahres 2019 vorgestellt. Ausgewählte Projekte stellten ihre Ergebnisse am 09. April und 12. November 2019 im Rahmen des Future SOC Lab Tags vor.
T3 - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam - 158
KW - Future SOC Lab
KW - research projects
KW - multicore architectures
KW - in-memory technology
KW - cloud computing
KW - machine learning
KW - artifical intelligence
KW - Future SOC Lab
KW - Forschungsprojekte
KW - Multicore Architekturen
KW - In-Memory Technologie
KW - Cloud Computing
KW - maschinelles Lernen
KW - künstliche Intelligenz
Y1 - 2024
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-597915
SN - 978-3-86956-564-4
SN - 1613-5652
SN - 2191-1665
IS - 158
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - JOUR
A1 - Romero Mujalli, Daniel
A1 - Rochow, Markus
A1 - Kahl, Sandra
A1 - Paraskevopoulou, Sofia
A1 - Folkertsma, Remco
A1 - Jeltsch, Florian
A1 - Tiedemann, Ralph
T1 - Adaptive and nonadaptive plasticity in changing environments
BT - Implications for sexual species with different life history strategies
JF - Ecology and evolution
N2 - Populations adapt to novel environmental conditions by genetic changes or phenotypic plasticity. Plastic responses are generally faster and can buffer fitness losses under variable conditions. Plasticity is typically modeled as random noise and linear reaction norms that assume simple one-to- one genotype–phenotype maps and no limits to the phenotypic response. Most studies on plasticity have focused on its effect on population viability. However, it is not clear, whether the advantage of plasticity depends solely on environmental fluctuations or also on the genetic and demographic properties (life histories) of populations. Here we present an individual-based model and study the relative importance of adaptive and nonadaptive plasticity for populations of sexual species with different life histories experiencing directional stochastic climate change. Environmental fluctuations were simulated using differentially autocorrelated climatic stochasticity or noise color, and scenarios of directiona climate change. Nonadaptive plasticity was simulated as a random environmental effect on trait development, while adaptive plasticity as a linear, saturating, or sinusoidal reaction norm. The last two imposed limits to the plastic response and emphasized flexible interactions of the genotype with the environment. Interestingly, this assumption led to (a) smaller phenotypic than genotypic variance in the population (many-to- one genotype–phenotype map) and the coexistence of polymorphisms, and (b) the maintenance of higher genetic variation—compared to linear reaction norms and genetic determinism—even when the population was exposed to a constant environment for several generations. Limits to plasticity led to genetic accommodation, when costs were negligible, and to the appearance of cryptic variation when limits were exceeded. We found that adaptive plasticity promoted population persistence under red environmental noise and was particularly important for life histories with low fecundity. Populations produing more offspring could cope with environmental fluctuations solely by genetic changes or random plasticity, unless environmental change was too fast.
KW - developmental canalization
KW - environmental change
KW - genetic accommodation
KW - Individual-based models
KW - limits
KW - many-to-one genotype–phenotype map
KW - noise color
KW - phenotypic plasticity
KW - reaction norms
KW - stochastic fluctuations
Y1 - 2020
U6 - https://doi.org/10.1002/ece3.7485
SN - 2045-7758
VL - 11
IS - 11
SP - 6341
EP - 6357
PB - John Wiley & Sons, Inc.
CY - New Jersey
ER -
TY - JOUR
A1 - Kayler, Zachary E.
A1 - Premke, Katrin
A1 - Gessler, Arthur
A1 - Gessner, Mark O.
A1 - Griebler, Christian
A1 - Hilt, Sabine
A1 - Klemedtsson, Leif
A1 - Kuzyakov, Yakov
A1 - Reichstein, Markus
A1 - Siemens, Jan
A1 - Totsche, Kai-Uwe
A1 - Tranvik, Lars
A1 - Wagner, Annekatrin
A1 - Weitere, Markus
A1 - Grossart, Hans-Peter
T1 - Integrating Aquatic and Terrestrial Perspectives to Improve Insights Into Organic Matter Cycling at the Landscape Scale
JF - Frontiers in Earth Science
N2 - Across a landscape, aquatic-terrestrial interfaces within and between ecosystems are hotspots of organic matter (OM) mineralization. These interfaces are characterized by sharp spatio-temporal changes in environmental conditions, which affect OM properties and thus control OM mineralization and other transformation processes. Consequently, the extent of OM movement at and across aquatic-terrestrial interfaces is crucial in determining OM turnover and carbon (C) cycling at the landscape scale. Here, we propose expanding current concepts in aquatic and terrestrial ecosystem sciences to comprehensively evaluate OM turnover at the landscape scale. We focus on three main concepts toward explaining OM turnover at the landscape scale: the landscape spatiotemporal context, OM turnover described by priming and ecological stoichiometry, and anthropogenic effects as a disruptor of natural OM transfer magnitudes and pathways. A conceptual framework is introduced that allows for discussing the disparities in spatial and temporal scales of OM transfer, changes in environmental conditions, ecosystem connectivity, and microbial-substrate interactions. The potential relevance of priming effects in both terrestrial and aquatic systems is addressed. For terrestrial systems, we hypothesize that the interplay between the influx of OM, its corresponding elemental composition, and the elemental demand of the microbial communities may alleviate spatial and metabolic thresholds. In comparison, substrate level OM dynamics may be substantially different in aquatic systems due to matrix effects that accentuate the role of abiotic conditions, substrate quality, and microbial community dynamics. We highlight the disproportionate impact anthropogenic activities can have on OM cycling across the landscape. This includes reversing natural OM flows through the landscape, disrupting ecosystem connectivity, and nutrient additions that cascade across the landscape. This knowledge is crucial for a better understanding of OM cycling in a landscape context, in particular since terrestrial and aquatic compartments may respond differently to the ongoing changes in climate, land use, and other anthropogenic interferences.
KW - landscape connectivity
KW - organic matter mineralization
KW - priming effects
KW - ecological stoichiometry
KW - aquatic-terrestrial interfaces
KW - anthropogenic interferences
Y1 - 2019
U6 - https://doi.org/10.3389/feart.2019.00127
SN - 2296-6463
VL - 7
PB - Frontiers Research Foundation
CY - Lausanne
ER -
TY - JOUR
A1 - Lundgreen, Regitze B. C.
A1 - Jaspers, Cornelia
A1 - Traving, Sachia J.
A1 - Ayala, Daniel J.
A1 - Lombard, Fabien
A1 - Grossart, Hans-Peter
A1 - Nielsen, Torkel G.
A1 - Munk, Peter
A1 - Riemann, Lasse
T1 - Eukaryotic and cyanobacterial communities associated with marine snow particles in the oligotrophic Sargasso Sea
JF - Scientific reports
N2 - Marine snow aggregates represent heterogeneous agglomerates of dead and living organic matter. Composition is decisive for their sinking rates, and thereby for carbon flux to the deep sea. For oligotrophic oceans, information on aggregate composition is particularly sparse. To address this, the taxonomic composition of aggregates collected from the subtropical and oligotrophic Sargasso Sea (Atlantic Ocean) was characterized by 16S and 18S rRNA gene sequencing. Taxonomy assignment was aided by a collection of the contemporary plankton community consisting of 75 morphologically and genetically identified plankton specimens. The diverse rRNA gene reads of marine snow aggregates, not considering Trichodesmium puffs, were dominated by copepods (52%), cnidarians (21%), radiolarians (11%), and alveolates (8%), with sporadic contributions by cyanobacteria, suggesting a different aggregate composition than in eutrophic regions. Composition linked significantly with sampling location but not to any measured environmental parameters or plankton biomass composition. Nevertheless, indicator and network analyses identified key roles of a few rare taxa. This points to complex regulation of aggregate composition, conceivably affected by the environment and plankton characteristics. The extent to which this has implications for particle densities, and consequently for sinking rates and carbon sequestration in oligotrophic waters, needs further interrogation.
Y1 - 2019
U6 - https://doi.org/10.1038/s41598-019-45146-7
SN - 2045-2322
VL - 9
PB - Nature Publ. Group
CY - London
ER -
TY - JOUR
A1 - Numberger, Daniela
A1 - Ganzert, Lars
A1 - Zoccarato, Luca
A1 - Mühldorfer, Kristin
A1 - Sauer, Sascha
A1 - Grossart, Hans-Peter
A1 - Greenwood, Alex D.
T1 - Characterization of bacterial communities in wastewater with enhanced taxonomic resolution by full-length 16S rRNA sequencing
JF - Scientific reports
N2 - Wastewater treatment is crucial to environmental hygiene in urban environments. However, wastewater treatment plants (WWTPs) collect chemicals, organic matter, and microorganisms including pathogens and multi-resistant bacteria from various sources which may be potentially released into the environment via WWTP effluent. To better understand microbial dynamics in WWTPs, we characterized and compared the bacterial community of the inflow and effluent of a WWTP in Berlin, Germany using full-length 16S rRNA gene sequences, which allowed for species level determination in many cases and generally resolved bacterial taxa. Significantly distinct bacterial communities were identified in the wastewater inflow and effluent samples. Dominant operational taxonomic units (OTUs) varied both temporally and spatially. Disease associated bacterial groups were efficiently reduced in their relative abundance from the effluent by the WWTP treatment process, except for Legionella and Leptospira species which demonstrated an increase in relative proportion from inflow to effluent. This indicates that WWTPs, while effective against enteric bacteria, may enrich and release other potentially pathogenic bacteria into the environment. The taxonomic resolution of full-length 16S rRNA genes allows for improved characterization of potential pathogenic taxa and other harmful bacteria which is required to reliably assess health risk.
Y1 - 2019
U6 - https://doi.org/10.1038/s41598-019-46015-z
SN - 2045-2322
VL - 9
PB - Nature Publ. Group
CY - London
ER -
TY - JOUR
A1 - Numberger, Daniela
A1 - Dreier, Carole
A1 - Vullioud, Colin
A1 - Gabriel, Gülsah
A1 - Greenwood, Alex D.
A1 - Grossart, Hans-Peter
T1 - Recovery of influenza a viruses from lake water and sediments by experimental inoculation
JF - PLoS one
N2 - Influenza A viruses (IAV) are zoonotic pathogens relevant to human, domestic animal and wildlife health. Many avian IAVs are transmitted among waterfowl via a faecal-oral-route. Therefore, environmental water where waterfowl congregate may play an important role in the ecology and epidemiology of avian IAV. Water and sediment may sustain and transmit virus among individuals or species. It is unclear at what concentrations waterborne viruses are infectious or remain detectable. To address this, we performed lake water and sediment dilution experiments with varying concentrations or infectious doses of four IAV strains from seal, turkey, duck and gull. To test for infectivity of the IAV strains in a concentration dependent manner, we applied cultivation to specific pathogen free (SPF) embryonated chicken eggs and Madin-Darby Canine Kidney (MDCK) cells. IAV recovery was more effective from embryonated chicken eggs than MDCK cells for freshwater lake dilutions, whereas, MDCK cells were more effective for viral recovery from sediment samples. Low infectious dose (1 PFU/200 mu L) was sufficient in most cases to detect and recover IAV from lake water dilutions. Sediment required higher initial infectious doses (>= 100 PFU/200 mu L).
Y1 - 2019
U6 - https://doi.org/10.1371/journal.pone.0216880
SN - 1932-6203
VL - 14
IS - 5
PB - PLoS
CY - San Fransisco
ER -
TY - JOUR
A1 - Rojas-Jimenez, Keilor
A1 - Grossart, Hans-Peter
A1 - Cordes, Erik
A1 - Cortés, Jorge
T1 - Fungal Communities in Sediments Along a Depth Gradient in the Eastern Tropical Pacific
JF - Frontiers in Microbiology
N2 - Deep waters represent the largest biome on Earth and the largest ecosystem of Costa Rica. Fungi play a fundamental role in global biogeochemical cycling in marine sediments, yet, they remain little explored. We studied fungal diversity and community composition in several marine sediments from 16 locations sampled along a bathymetric gradient (from a depth of 380 to 3,474 m) in two transects of about 1,500 km length in the Eastern Tropical Pacific (ETP) of Costa Rica. Sequence analysis of the V7-V8 region of the 18S rRNA gene obtained from sediment cores revealed the presence of 787 fungal amplicon sequence variants (ASVs). On average, we detected a richness of 75 fungal ASVs per sample. Ascomycota represented the most abundant phylum with Saccharomycetes constituting the dominant class. Three ASVs accounted for ca. 63% of all fungal sequences: the yeast Metschnikowia (49.4%), Rhizophydium (6.9%), and Cladosporium (6.7%). We distinguished a cluster composed mainly by yeasts, and a second cluster by filamentous fungi, but we were unable to detect a strong effect of depth and the overlying water temperature, salinity, dissolved oxygen (DO), and pH on the composition of fungal communities. We highlight the need to understand further the ecological role of fungi in deep-sea ecosystems.
KW - deep-sea
KW - aquatic fungi
KW - biodiversity
KW - Metschnikowia
KW - Costa Rica
Y1 - 2020
U6 - https://doi.org/10.3389/fmicb.2020.575207
SN - 1664-302X
VL - 11
PB - Frontiers Media
CY - Lausanne
ER -
TY - GEN
A1 - Numberger, Daniela
A1 - Dreier, Carola
A1 - Vullioud, Colin
A1 - Gabriel, Guelsah
A1 - Greenwood, Alex D.
A1 - Grossart, Hans-Peter
T1 - Correction: Recovery of influenza A viruses from lake water and sediments by experimental inoculation (vol 14, e0216880, 2019)
T2 - PLoS one
Y1 - 2019
U6 - https://doi.org/10.1371/journal.pone.0218882
SN - 1932-6203
VL - 14
IS - 6
PB - PLoS
CY - San Fransisco
ER -
TY - JOUR
A1 - Tiegs, Scott D.
A1 - Costello, David M.
A1 - Isken, Mark W.
A1 - Woodward, Guy
A1 - McIntyre, Peter B.
A1 - Gessner, Mark O.
A1 - Chauvet, Eric
A1 - Griffiths, Natalie A.
A1 - Flecker, Alex S.
A1 - Acuna, Vicenc
A1 - Albarino, Ricardo
A1 - Allen, Daniel C.
A1 - Alonso, Cecilia
A1 - Andino, Patricio
A1 - Arango, Clay
A1 - Aroviita, Jukka
A1 - Barbosa, Marcus V. M.
A1 - Barmuta, Leon A.
A1 - Baxter, Colden V.
A1 - Bell, Thomas D. C.
A1 - Bellinger, Brent
A1 - Boyero, Luz
A1 - Brown, Lee E.
A1 - Bruder, Andreas
A1 - Bruesewitz, Denise A.
A1 - Burdon, Francis J.
A1 - Callisto, Marcos
A1 - Canhoto, Cristina
A1 - Capps, Krista A.
A1 - Castillo, Maria M.
A1 - Clapcott, Joanne
A1 - Colas, Fanny
A1 - Colon-Gaud, Checo
A1 - Cornut, Julien
A1 - Crespo-Perez, Veronica
A1 - Cross, Wyatt F.
A1 - Culp, Joseph M.
A1 - Danger, Michael
A1 - Dangles, Olivier
A1 - de Eyto, Elvira
A1 - Derry, Alison M.
A1 - Diaz Villanueva, Veronica
A1 - Douglas, Michael M.
A1 - Elosegi, Arturo
A1 - Encalada, Andrea C.
A1 - Entrekin, Sally
A1 - Espinosa, Rodrigo
A1 - Ethaiya, Diana
A1 - Ferreira, Veronica
A1 - Ferriol, Carmen
A1 - Flanagan, Kyla M.
A1 - Fleituch, Tadeusz
A1 - Shah, Jennifer J. Follstad
A1 - Frainer, Andre
A1 - Friberg, Nikolai
A1 - Frost, Paul C.
A1 - Garcia, Erica A.
A1 - Lago, Liliana Garcia
A1 - Garcia Soto, Pavel Ernesto
A1 - Ghate, Sudeep
A1 - Giling, Darren P.
A1 - Gilmer, Alan
A1 - Goncalves, Jose Francisco
A1 - Gonzales, Rosario Karina
A1 - Graca, Manuel A. S.
A1 - Grace, Mike
A1 - Grossart, Hans-Peter
A1 - Guerold, Francois
A1 - Gulis, Vlad
A1 - Hepp, Luiz U.
A1 - Higgins, Scott
A1 - Hishi, Takuo
A1 - Huddart, Joseph
A1 - Hudson, John
A1 - Imberger, Samantha
A1 - Iniguez-Armijos, Carlos
A1 - Iwata, Tomoya
A1 - Janetski, David J.
A1 - Jennings, Eleanor
A1 - Kirkwood, Andrea E.
A1 - Koning, Aaron A.
A1 - Kosten, Sarian
A1 - Kuehn, Kevin A.
A1 - Laudon, Hjalmar
A1 - Leavitt, Peter R.
A1 - Lemes da Silva, Aurea L.
A1 - Leroux, Shawn J.
A1 - Leroy, Carri J.
A1 - Lisi, Peter J.
A1 - MacKenzie, Richard
A1 - Marcarelli, Amy M.
A1 - Masese, Frank O.
A1 - Mckie, Brendan G.
A1 - Oliveira Medeiros, Adriana
A1 - Meissner, Kristian
A1 - Milisa, Marko
A1 - Mishra, Shailendra
A1 - Miyake, Yo
A1 - Moerke, Ashley
A1 - Mombrikotb, Shorok
A1 - Mooney, Rob
A1 - Moulton, Tim
A1 - Muotka, Timo
A1 - Negishi, Junjiro N.
A1 - Neres-Lima, Vinicius
A1 - Nieminen, Mika L.
A1 - Nimptsch, Jorge
A1 - Ondruch, Jakub
A1 - Paavola, Riku
A1 - Pardo, Isabel
A1 - Patrick, Christopher J.
A1 - Peeters, Edwin T. H. M.
A1 - Pozo, Jesus
A1 - Pringle, Catherine
A1 - Prussian, Aaron
A1 - Quenta, Estefania
A1 - Quesada, Antonio
A1 - Reid, Brian
A1 - Richardson, John S.
A1 - Rigosi, Anna
A1 - Rincon, Jose
A1 - Risnoveanu, Geta
A1 - Robinson, Christopher T.
A1 - Rodriguez-Gallego, Lorena
A1 - Royer, Todd V.
A1 - Rusak, James A.
A1 - Santamans, Anna C.
A1 - Selmeczy, Geza B.
A1 - Simiyu, Gelas
A1 - Skuja, Agnija
A1 - Smykla, Jerzy
A1 - Sridhar, Kandikere R.
A1 - Sponseller, Ryan
A1 - Stoler, Aaron
A1 - Swan, Christopher M.
A1 - Szlag, David
A1 - Teixeira-de Mello, Franco
A1 - Tonkin, Jonathan D.
A1 - Uusheimo, Sari
A1 - Veach, Allison M.
A1 - Vilbaste, Sirje
A1 - Vought, Lena B. M.
A1 - Wang, Chiao-Ping
A1 - Webster, Jackson R.
A1 - Wilson, Paul B.
A1 - Woelfl, Stefan
A1 - Xenopoulos, Marguerite A.
A1 - Yates, Adam G.
A1 - Yoshimura, Chihiro
A1 - Yule, Catherine M.
A1 - Zhang, Yixin X.
A1 - Zwart, Jacob A.
T1 - Global patterns and drivers of ecosystem functioning in rivers and riparian zones
JF - Science Advances
N2 - River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth’s biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constraints toward the poles and greater roles for other environmental drivers (e.g., nutrient loading) toward the equator. These results and data set the stage for unprecedented “next-generation biomonitoring” by establishing baselines to help quantify environmental impacts to the functioning of ecosystems at a global scale.
Y1 - 2019
U6 - https://doi.org/10.1126/sciadv.aav0486
SN - 2375-2548
VL - 5
IS - 1
PB - American Assoc. for the Advancement of Science
CY - Washington
ER -
TY - BOOK
A1 - Curiel Martínez, Geishel
ED - Ette, Ottmar
T1 - Rumbo a Venecia
T1 - Richtung Venedig
T1 - Towards Venice
BT - espacio y movimiento en viajes ficcionales al laberinto lacustre
BT - Raum und Bewegung in fiktionalen Reisen zum Lagunenlabyrinth
BT - space and movement in fictional journeys to the lagoon labyrinth
N2 - Esta investigación explora la representación de viajes a Venecia en la literatura latinoamericana y de lengua alemana del siglo XX. Aplicando planteamientos teóricos de literatura de viaje, se descodifica la estructura mítica que subyace en la descripción del desplazamiento hacia la ciudad lacustre. El objetivo es exponer los recursos narrativos y estilísticos utilizados para entrelazar este recorrido, en su mayoría oblicuo, con la emersión gradual del conflicto de los y las protagonistas. Además, a partir del estudio comparativo de algunos elementos arquitectónicos emblemáticos como son los palacios, los puentes y, sobre todo, la conformación laberíntica, se muestran las peculiaridades de la representación de Venecia en obras de Julieta Campos, Alejo Carpentier, Julio Cortázar, Hugo von Hofmannsthal, Thomas Mann y Sergio Pitol. Con ello se busca, primeramente, visibilizar el papel de Venecia en la literatura latinoamericana y, segundo, ofrecer nuevas claves de lectura a obras que han sido ampliamente estudiadas, mas no en una confrontación transareal.
N2 - Diese Studie untersucht die Darstellung von Reisen nach Venedig in der lateinamerikanischen und deutschsprachigen Literatur des zwanzigsten Jahrhunderts. Anhand theoretischer Ansätze zur Reiseliteratur wird die mythische Struktur entschlüsselt, die der Beschreibung der Reise in die Lagunenstadt zugrunde liegt. Ziel ist es, die erzählerischen und stilistischen Mittel aufzuzeigen, mit denen diese meist schemenhafte Reise mit der allmählichen Herausbildung des Konflikts der Protagonisten verwoben wird. Darüber hinaus werden anhand der vergleichenden Untersuchung einiger emblematischer architektonischer Elemente wie Paläste, Brücken und vor allem des labyrinthischen Aufbaus die Besonderheiten der Darstellung Venedigs in Werken von Julieta Campos, Alejo Carpentier, Julio Cortázar, Hugo von Hofmannsthal, Thomas Mann und Sergio Pitol aufgezeigt. Ziel ist es, erstens die Rolle Venedigs in der lateinamerikanischen Literatur sichtbar zu machen und zweitens neue Schlüssel für die Lektüre von Werken anzubieten, die zwar vielfach untersucht wurden, aber nicht in einer transareale Gegenüberstellung.
N2 - This research explores the representation of journeys to Venice in twentieth-century Latin American and German-language literature. Theoretical approaches to travel writing are used to decipher the mythical structure underlying the description of the journey to the lagoon city. The aim is to show the narrative and stylistic means by which this mostly shadowy journey is interwoven with the gradual emergence of the protagonists' conflict. Furthermore, through the comparative study of some emblematic architectural elements such as palaces, bridges and, above all, the labyrinthine structure, the specificities of the representation of Venice in works by Julieta Campos, Alejo Carpentier, Julio Cortázar, Hugo von Hofmannsthal, Thomas Mann and Sergio Pitol will be highlighted. The aim is firstly to make visible the role of Venice in Latin American literature and secondly to offer new keys for reading works that have been widely studied, but not in a transareal juxtaposition.
T3 - Potsdamer Bibliothek der WeltRegionen (PoWeR) - 7
KW - literatura de viaje
KW - Venecia
KW - literatura latinoamericana
KW - literatura alemana y austríaca
KW - Reiseliteratur
KW - Venedig
KW - lateinamerikanische Literatur
KW - deutschsprachige Literatur
KW - travel writing
KW - Venice
KW - Latin American literature
KW - German-language literature
Y1 - 2024
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-586964
SN - 978-3-86956-558-3
SN - 2629-2548
SN - 2629-253X
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - JOUR
A1 - Woodfield, Emma E.
A1 - Horne, Richard B.
A1 - Glauert, S. A.
A1 - Menietti, J. D.
A1 - Shprits, Yuri
A1 - Kurth, William S.
T1 - Formation of electron radiation belts at Saturn by Z-mode wave acceleration
JF - Nature Communications
N2 - At Saturn electrons are trapped in the planet’s magnetic field and accelerated to relativistic energies to form the radiation belts, but how this dramatic increase in electron energy occurs is still unknown. Until now the mechanism of radial diffusion has been assumed but we show here that in-situ acceleration through wave particle interactions, which initial studies dismissed as ineffectual at Saturn, is in fact a vital part of the energetic particle dynamics there. We present evidence from numerical simulations based on Cassini spacecraft data that a particular plasma wave, known as Z-mode, accelerates electrons to MeV energies inside 4 RS (1 RS = 60,330 km) through a Doppler shifted cyclotron resonant interaction. Our results show that the Z-mode waves observed are not oblique as previously assumed and are much better accelerators than O-mode waves, resulting in an electron energy spectrum that closely approaches observed values without any transport effects included.
Y1 - 2018
U6 - https://doi.org/10.1038/s41467-018-07549-4
SN - 2041-1723
VL - 9
PB - Nature Publ. Group
CY - London
ER -
TY - JOUR
A1 - Quarmby, Andrew
A1 - Zhang, Martin
A1 - Geisler, Moritz
A1 - Javorsky, Tomas
A1 - Mugele, Hendrik
A1 - Cassel, Michael
A1 - Lawley, Justin
T1 - Risk factors and injury prevention strategies for overuse injuries in adult climbers
BT - a systematic review
JF - Frontiers in sports and active living
N2 - Introduction Climbing is an increasingly popular activity and imposes specific physiological demands on the human body, which results in unique injury presentations. Of particular concern are overuse injuries (non-traumatic injuries). These injuries tend to present in the upper body and might be preventable with adequate knowledge of risk factors which could inform about injury prevention strategies. Research in this area has recently emerged but has yet to be synthesized comprehensively. Therefore, the aim of this study was to conduct a systematic review of the potential risk factors and injury prevention strategies for overuse injuries in adult climbers.
Methods This systematic review was conducted in accordance with the PRISMA guidelines. Databases were searched systematically, and articles were deemed eligible based upon specific criteria. Research included was original and peer-reviewed, involving climbers, and published in English, German or Czech. Outcomes included overuse injury, and at least one or more variable indicating potential risk factors or injury prevention strategies. The methodological quality of the included studies was assessed with the Downs and Black Quality Index. Data were extracted from included studies and reported descriptively for population, climbing sport type, study design, injury definition and incidence/prevalence, risk factors, and injury prevention strategies.
Results Out of 1,183 records, a total of 34 studies were included in the final analysis. Higher climbing intensity, bouldering, reduced grip/finger strength, use of a “crimp” grip, and previous injury were associated with an increased risk of overuse injury. Additionally, a strength training intervention prevented shoulder and elbow injuries. BMI/body weight, warm up/cool downs, stretching, taping and hydration were not associated with risk of overuse injury. The evidence for the risk factors of training volume, age/years of climbing experience, and sex was conflicting.
Discussion This review presents several risk factors which appear to increase the risk of overuse injury in climbers. Strength and conditioning, load management, and climbing technique could be targeted in injury prevention programs, to enhance the health and wellbeing of climbing athletes. Further research is required to investigate the conflicting findings reported across included studies, and to investigate the effectiveness of injury prevention programs.
Systematic Review Registrationhttps://www.crd.york.ac.uk/, PROSPERO (CRD42023404031).
KW - climbing
KW - bouldering
KW - overuse injuries
KW - risk factors
KW - injury prevention
KW - systematic reveiw
KW - climbing injuries
Y1 - 2023
U6 - https://doi.org/10.3389/fspor.2023.1269870
SN - 2624-9367
VL - 5
PB - Frontiers Media
CY - Lausanne
ER -