TY - JOUR
A1 - Kühne, Katharina
A1 - Nenaschew, Kristina
A1 - Miklashevsky, Alex
T1 - Space-valence mapping of social concepts
BT - Do we arrange negative and positive ethnic stereotypes from left to right?
JF - Frontiers in Psychology
N2 - Introduction: The body-specificity hypothesis states that in right-handers, positive concepts should be associated with the right side and negative concepts with the left side of the body. Following this hypothesis, our study postulated that negative out-group ethnic stereotypes would be associated with the left side, and positive in-group stereotypes would be associated with the right side.
Methods: The experiment consisted of two parts. First, we measured the spatial mapping of ethnic stereotypes by using a sensibility judgment task, in which participants had to decide whether a sentence was sensible or not by pressing either a left or a right key. The sentences included German vs. Arabic proper names. Second, we measured implicit ethnic stereotypes in the same participants using the Go/No-go Association Task (GNAT), in which Arabic vs. German proper names were presented in combination with positive vs. negative adjectives. Right-handed German native speakers (N = 92) participated in an online study.
Results: As predicted, in the GNAT, participants reacted faster to German names combined with positive adjectives and to Arabic names combined with negative adjectives, which is diagnostic of existing valenced in-and outgroup ethnic stereotypes. However, we failed to find any reliable effects in the sensibility judgment task, i.e., there was no evidence of spatial mapping of positive and negative ethnic stereotypes. There was no correlation between the results of the two tasks at the individual level. Further Bayesian analysis and exploratory analysis in the left-handed subsample (N = 9) corroborated the evidence in favor of null results.
Discussion: Our study suggests that ethnic stereotypes are not automatically mapped in a body-specific manner.
KW - body-specificity hypothesis
KW - embodied cognition
KW - ethnic stereotypes
KW - in-group stereotypes
KW - implicit associations
KW - GNAT
KW - out-group stereotypes
Y1 - 2022
U6 - https://doi.org/10.3389/fpsyg.2022.1070177
SN - 1664-1078
VL - 13
PB - Frontiers
CY - Lausanne, Schweiz
ER -
TY - JOUR
A1 - Schaefer, Laura
A1 - Dech, Silas
A1 - Bittmann, Frank
T1 - Adaptive force and emotionally related imaginations
BT - Preliminary results suggest a reduction of the maximal holding capacity as reaction to disgusting food imagination
JF - Heliyon
N2 - The link between emotions and motor control has been discussed for years. The measurement of the Adaptive Force (AF) provides the possibility to get insights into the adaptive control of the neuromuscular system in reaction to external forces. It was hypothesized that the holding isometric AF is especially vulnerable to disturbing inputs. Here, the behavior of the AF under the influence of positive (tasty) vs. negative (disgusting) food imaginations was investigated. The AF was examined in n = 12 cases using an objectified manual muscle test of the hip flexors, elbow flexors or pectoralis major muscle, performed by one of two experienced testers while the participants imagined their most tasty or most disgusting food. The reaction force and the limb position were measured by a handheld device. While the slope of force rises and the maximal AF did not differ significantly between tasty and disgusting imaginations (p > 0.05), the maximal isometric AF was significantly lower and the AF at the onset of oscillations was significantly higher under disgusting vs. tasty imaginations (both p = 0.001). A proper length tension control of muscles seems to be a crucial functional parameter of the neuromuscular system which can be impaired instantaneously by emotionally related negative imaginations. This might be a potential approach to evaluate somatic reactions to emotions.
KW - Adaptive Force
KW - Isometric Adaptive Force
KW - Holding capacity
KW - Holding
KW - isometric muscle action
KW - Imaginations
KW - Emotions
KW - Motor control
KW - Functional weakness
KW - Manual muscle test
Y1 - 2021
U6 - https://doi.org/10.1016/j.heliyon.2021.e07827
SN - 2405-8440
VL - 7
IS - 8
PB - Elsevier
CY - London
ER -
TY - JOUR
A1 - Kühne, Katharina
A1 - Fischer, Martin H.
A1 - Jeglinski-Mende, Melinda A.
T1 - During the COVID-19 pandemic participants prefer settings with a face mask, no interaction and at a closer distance
JF - Scientific Reports
N2 - Peripersonal space is the space surrounding our body, where multisensory integration of stimuli and action execution take place. The size of peripersonal space is flexible and subject to change by various personal and situational factors. The dynamic representation of our peripersonal space modulates our spatial behaviors towards other individuals. During the COVID-19 pandemic, this spatial behavior was modified by two further factors: social distancing and wearing a face mask. Evidence from offline and online studies on the impact of a face mask on pro-social behavior is mixed. In an attempt to clarify the role of face masks as pro-social or anti-social signals, 235 observers participated in the present online study. They watched pictures of two models standing at three different distances from each other (50, 90 and 150 cm), who were either wearing a face mask or not and were either interacting by initiating a hand shake or just standing still. The observers’ task was to classify the model by gender. Our results show that observers react fastest, and therefore show least avoidance, for the shortest distances (50 and 90 cm) but only when models wear a face mask and do not interact. Thus, our results document both pro- and anti-social consequences of face masks as a result of the complex interplay between social distancing and interactive behavior. Practical implications of these findings are discussed.
Y1 - 2022
U6 - https://doi.org/10.1038/s41598-022-16730-1
SN - 2045-2322
VL - 12
SP - 1
EP - 12
PB - Springer Nature
CY - Berlin
ER -
TY - JOUR
A1 - Schaefer, Laura
A1 - Bittmann, Frank
T1 - The adaptive force as a potential biomechanical parameter in the recovery process of patients with long COVID
JF - Diagnostics
N2 - Long COVID patients show symptoms, such as fatigue, muscle weakness and pain. Adequate diagnostics are still lacking. Investigating muscle function might be a beneficial approach. The holding capacity (maximal isometric Adaptive Force; AFisomax) was previously suggested to be especially sensitive for impairments. This longitudinal, non-clinical study aimed to investigate the AF in long COVID patients and their recovery process. AF parameters of elbow and hip flexors were assessed in 17 patients at three time points (pre: long COVID state, post: immediately after first treatment, end: recovery) by an objectified manual muscle test. The tester applied an increasing force on the limb of the patient, who had to resist isometrically for as long as possible. The intensity of 13 common symptoms were queried. At pre, patients started to lengthen their muscles at ~50% of the maximal AF (AFmax), which was then reached during eccentric motion, indicating unstable adaptation. At post and end, AFisomax increased significantly to ~99% and 100% of AFmax, respectively, reflecting stable adaptation. AFmax was statistically similar for all three time points. Symptom intensity decreased significantly from pre to end. The findings revealed a substantially impaired maximal holding capacity in long COVID patients, which returned to normal function with substantial health improvement. AFisomax might be a suitable sensitive functional parameter to assess long COVID patients and to support therapy process
KW - Adaptive Force
KW - maximal isometric Adaptive Force
KW - holding capacity
KW - muscle function
KW - long COVID fatigue
KW - post COVID syndrome
KW - muscle weakness
KW - neuromuscular control
KW - biomechanical parameter
Y1 - 2023
U6 - https://doi.org/10.3390/diagnostics13050882
SN - 2075-4418
VL - 13
IS - 5
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Bosch, Sina
A1 - De Cesare, Ilaria
A1 - Demske, Ulrike
A1 - Felser, Claudia
T1 - New empirical approaches to grammatical variation and change
JF - Languages : open access journal
Y1 - 2021
U6 - https://doi.org/10.3390/languages6030113
SN - 2226-471X
VL - 6
IS - 3
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Maier, Corinna Sabrina
A1 - Wiljes, Jana de
A1 - Hartung, Niklas
A1 - Kloft, Charlotte
A1 - Huisinga, Wilhelm
T1 - A continued learning approach for model-informed precision dosing
BT - Updating models in clinical practice
JF - CPT: pharmacometrics & systems pharmacology
N2 - Model-informed precision dosing (MIPD) is a quantitative dosing framework that combines prior knowledge on the drug-disease-patient system with patient data from therapeutic drug/ biomarker monitoring (TDM) to support individualized dosing in ongoing treatment. Structural models and prior parameter distributions used in MIPD approaches typically build on prior clinical trials that involve only a limited number of patients selected according to some exclusion/inclusion criteria. Compared to the prior clinical trial population, the patient population in clinical practice can be expected to also include altered behavior and/or increased interindividual variability, the extent of which, however, is typically unknown. Here, we address the question of how to adapt and refine models on the level of the model parameters to better reflect this real-world diversity. We propose an approach for continued learning across patients during MIPD using a sequential hierarchical Bayesian framework. The approach builds on two stages to separate the update of the individual patient parameters from updating the population parameters. Consequently, it enables continued learning across hospitals or study centers, because only summary patient data (on the level of model parameters) need to be shared, but no individual TDM data. We illustrate this continued learning approach with neutrophil-guided dosing of paclitaxel. The present study constitutes an important step toward building confidence in MIPD and eventually establishing MIPD increasingly in everyday therapeutic use.
Y1 - 2021
U6 - https://doi.org/10.1002/psp4.12745
SN - 2163-8306
VL - 11
IS - 2
SP - 185
EP - 198
PB - London
CY - Nature Publ. Group
ER -
TY - JOUR
A1 - Hartung, Niklas
A1 - Wahl, Martin
A1 - Rastogi, Abhishake
A1 - Huisinga, Wilhelm
T1 - Nonparametric goodness-of-fit testing for parametric covariate models in pharmacometric analyses
JF - CPT: pharmacometrics & systems pharmacology
N2 - The characterization of covariate effects on model parameters is a crucial step during pharmacokinetic/pharmacodynamic analyses. Although covariate selection criteria have been studied extensively, the choice of the functional relationship between covariates and parameters, however, has received much less attention. Often, a simple particular class of covariate-to-parameter relationships (linear, exponential, etc.) is chosen ad hoc or based on domain knowledge, and a statistical evaluation is limited to the comparison of a small number of such classes. Goodness-of-fit testing against a nonparametric alternative provides a more rigorous approach to covariate model evaluation, but no such test has been proposed so far. In this manuscript, we derive and evaluate nonparametric goodness-of-fit tests for parametric covariate models, the null hypothesis, against a kernelized Tikhonov regularized alternative, transferring concepts from statistical learning to the pharmacological setting. The approach is evaluated in a simulation study on the estimation of the age-dependent maturation effect on the clearance of a monoclonal antibody. Scenarios of varying data sparsity and residual error are considered. The goodness-of-fit test correctly identified misspecified parametric models with high power for relevant scenarios. The case study provides proof-of-concept of the feasibility of the proposed approach, which is envisioned to be beneficial for applications that lack well-founded covariate models.
Y1 - 2021
U6 - https://doi.org/10.1002/psp4.12614
SN - 2163-8306
VL - 10
IS - 6
SP - 564
EP - 576
PB - Nature Publ. Group
CY - London
ER -
TY - JOUR
A1 - Démaris, Alix
A1 - Widigson, Ella S. K.
A1 - Ilvemark, Johan F. K. F.
A1 - Steenholdt, Casper
A1 - Seidelin, Jakob B.
A1 - Huisinga, Wilhelm
A1 - Michelet, Robin
A1 - Aulin, Linda B. S.
A1 - Kloft, Charlotte
T1 - Ulcerative colitis and acute severe ulcerative colitis patients are overlooked in infliximab population pharmacokinetic models
BT - results from a comprehensive review
JF - Pharmaceutics / Molecular Diversity Preservation International
N2 - Ulcerative colitis (UC) is part of the inflammatory bowels diseases, and moderate to severe UC patients can be treated with anti-tumour necrosis alpha monoclonal antibodies, including infliximab (IFX). Even though treatment of UC patients by IFX has been in place for over a decade, many gaps in modelling of IFX PK in this population remain. This is even more true for acute severe UC (ASUC) patients for which early prediction of IFX pharmacokinetic (PK) could highly improve treatment outcome. Thus, this review aims to compile and analyse published population PK models of IFX in UC and ASUC patients, and to assess the current knowledge on disease activity impact on IFX PK. For this, a semi-systematic literature search was conducted, from which 26 publications including a population PK model analysis of UC patients receiving IFX therapy were selected. Amongst those, only four developed a model specifically for UC patients, and only three populations included severe UC patients. Investigations of disease activity impact on PK were reported in only 4 of the 14 models selected. In addition, the lack of reported model codes and assessment of predictive performance make the use of published models in a clinical setting challenging. Thus, more comprehensive investigation of PK in UC and ASUC is needed as well as more adequate reports on developed models and their evaluation in order to apply them in a clinical setting.
KW - infliximab
KW - inflammatory bowel disease
KW - ulcerative colitis
KW - acute severe
KW - disease activity
KW - pharmacokinetic
KW - pharmacometrics
Y1 - 2022
U6 - https://doi.org/10.3390/pharmaceutics14102095
SN - 1999-4923
VL - 14
IS - 10
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Moldenhawer, Ted
A1 - Moreno, Eduardo
A1 - Schindler, Daniel
A1 - Flemming, Sven
A1 - Holschneider, Matthias
A1 - Huisinga, Wilhelm
A1 - Alonso, Sergio
A1 - Beta, Carsten
T1 - Spontaneous transitions between amoeboid and keratocyte-like modes of migration
JF - Frontiers in Cell and Developmental Biology
N2 - The motility of adherent eukaryotic cells is driven by the dynamics of the actin cytoskeleton. Despite the common force-generating actin machinery, different cell types often show diverse modes of locomotion that differ in their shape dynamics, speed, and persistence of motion. Recently, experiments in Dictyostelium discoideum have revealed that different motility modes can be induced in this model organism, depending on genetic modifications, developmental conditions, and synthetic changes of intracellular signaling. Here, we report experimental evidence that in a mutated D. discoideum cell line with increased Ras activity, switches between two distinct migratory modes, the amoeboid and fan-shaped type of locomotion, can even spontaneously occur within the same cell. We observed and characterized repeated and reversible switchings between the two modes of locomotion, suggesting that they are distinct behavioral traits that coexist within the same cell. We adapted an established phenomenological motility model that combines a reaction-diffusion system for the intracellular dynamics with a dynamic phase field to account for our experimental findings.
KW - cell migration
KW - amoeboid motility
KW - keratocytle-like motility
KW - modes of
KW - migration
KW - D. discoideum
KW - actin dynamics
Y1 - 2022
U6 - https://doi.org/10.3389/fcell.2022.898351
SN - 2296-634X
VL - 10
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Hafner, Verena
A1 - Hommel, Bernhard
A1 - Kayhan, Ezgi
A1 - Lee, Dongheui
A1 - Paulus, Markus
A1 - Verschoor, Stephan
T1 - Editorial: The mechanisms underlying the human minimal self
JF - Frontiers in psychology
KW - agents
KW - self
KW - minimal self
KW - robotics
KW - humanoids
KW - cognition
Y1 - 2022
U6 - https://doi.org/10.3389/fpsyg.2022.961480
SN - 1664-1078
VL - 13
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Arntz, Fabian
A1 - Mkaouer, Bessem
A1 - Markov, Adrian
A1 - Schoenfeld, Brad
A1 - Moran, Jason
A1 - Ramirez-Campillo, Rodrigo
A1 - Behrens, Martin
A1 - Baumert, Philipp
A1 - Erskine, Robert M.
A1 - Hauser, Lukas
A1 - Chaabene, Helmi
T1 - Effect of Plyometric Jump Training on Skeletal Muscle Hypertrophy in Healthy Individuals: A Systematic Review With Multilevel Meta-Analysis
JF - Frontiers in Physiology
N2 - Objective: To examine the effect of plyometric jump training on skeletal muscle hypertrophy in healthy individuals.
Methods: A systematic literature search was conducted in the databases PubMed, SPORTDiscus, Web of Science, and Cochrane Library up to September 2021.
Results: Fifteen studies met the inclusion criteria. The main overall finding (44 effect sizes across 15 clusters median = 2, range = 1–15 effects per cluster) indicated that plyometric jump training had small to moderate effects [standardised mean difference (SMD) = 0.47 (95% CIs = 0.23–0.71); p < 0.001] on skeletal muscle hypertrophy. Subgroup analyses for training experience revealed trivial to large effects in non-athletes [SMD = 0.55 (95% CIs = 0.18–0.93); p = 0.007] and trivial to moderate effects in athletes [SMD = 0.33 (95% CIs = 0.16–0.51); p = 0.001]. Regarding muscle groups, results showed moderate effects for the knee extensors [SMD = 0.72 (95% CIs = 0.66–0.78), p < 0.001] and equivocal effects for the plantar flexors [SMD = 0.65 (95% CIs = −0.25–1.55); p = 0.143]. As to the assessment methods of skeletal muscle hypertrophy, findings indicated trivial to small effects for prediction equations [SMD = 0.29 (95% CIs = 0.16–0.42); p < 0.001] and moderate-to-large effects for ultrasound imaging [SMD = 0.74 (95% CIs = 0.59–0.89); p < 0.001]. Meta-regression analysis indicated that the weekly session frequency moderates the effect of plyometric jump training on skeletal muscle hypertrophy, with a higher weekly session frequency inducing larger hypertrophic gains [β = 0.3233 (95% CIs = 0.2041–0.4425); p < 0.001]. We found no clear evidence that age, sex, total training period, single session duration, or the number of jumps per week moderate the effect of plyometric jump training on skeletal muscle hypertrophy [β = −0.0133 to 0.0433 (95% CIs = −0.0387 to 0.1215); p = 0.101–0.751].
Conclusion: Plyometric jump training can induce skeletal muscle hypertrophy, regardless of age and sex. There is evidence for relatively larger effects in non-athletes compared with athletes. Further, the weekly session frequency seems to moderate the effect of plyometric jump training on skeletal muscle hypertrophy, whereby more frequent weekly plyometric jump training sessions elicit larger hypertrophic adaptations.
KW - muscle tissue
KW - muscle strength
KW - stretch shortening cycle exercise
KW - muscle growth
KW - human physical conditioning
KW - youth sports
KW - aged
Y1 - 2022
U6 - https://doi.org/10.3389/fphys.2022.888464
SN - 1664-042X
VL - 13
SP - 1
EP - 17
PB - Frontiers
CY - Lausanne, Schweiz
ET - 888464
ER -
TY - JOUR
A1 - Havermann, Felix
A1 - Ghirardo, Andrea
A1 - Schnitzler, Jörg-Peter
A1 - Nendel, Claas
A1 - Hoffmann, Mathias
A1 - Kraus, David
A1 - Grote, Rüdiger
T1 - Modeling intra- and interannual variability of BVOC emissions from maize, oil-seed rape, and ryegrass
JF - Journal of advances in modeling earth systems
N2 - Air chemistry is affected by the emission of biogenic volatile organic compounds (BVOCs), which originate from almost all plants in varying qualities and quantities. They also vary widely among different crops, an aspect that has been largely neglected in emission inventories. In particular, bioenergy-related species can emit mixtures of highly reactive compounds that have received little attention so far. For such species, long-term field observations of BVOC exchange from relevant crops covering different phenological phases are scarcely available. Therefore, we measured and modeled the emission of three prominent European bioenergy crops (maize, ryegrass, and oil-seed rape) for full rotations in north-eastern Germany. Using a proton transfer reaction-mass spectrometer combined with automatically moving large canopy chambers, we were able to quantify the characteristic seasonal BVOC flux dynamics of each crop species. The measured BVOC fluxes were used to parameterize and evaluate the BVOC emission module (JJv) of the physiology-oriented LandscapeDNDC model, which was enhanced to cover de novo emissions as well as those from plant storage pools. Parameters are defined for each compound individually. The model is used for simulating total compound-specific reactivity over several years and also to evaluate the importance of these emissions for air chemistry. We can demonstrate substantial differences between the investigated crops with oil-seed rape having 37-fold higher total annual emissions than maize. However, due to a higher chemical reactivity of the emitted blend in maize, potential impacts on atmospheric OH-chemistry are only 6-fold higher.
KW - biogenic volatile organic compounds
KW - process-based modeling
KW - Zea mays
KW - Brassica napus
KW - Lolium multiflorum
KW - plant ontogenetic stage
Y1 - 2022
U6 - https://doi.org/10.1029/2021MS002683
SN - 1942-2466
VL - 14
IS - 3
PB - American Geophysical Union
CY - Washington
ER -
TY - JOUR
A1 - Wicha, Sebastian G.
A1 - Huisinga, Wilhelm
A1 - Kloft, Charlotte
T1 - Translational pharmacometric evaluation of typical antibiotic broad-spectrum combination therapies against staphylococcus aureus exploiting in vitro information
JF - CPT: pharmacometrics & systems pharmacology
N2 - Broad-spectrum antibiotic combination therapy is frequently applied due to increasing resistance development of infective pathogens. The objective of the present study was to evaluate two common empiric broad-spectrum combination therapies consisting of either linezolid (LZD) or vancomycin (VAN) combined with meropenem (MER) against Staphylococcus aureus (S. aureus) as the most frequent causative pathogen of severe infections. A semimechanistic pharmacokinetic-pharmacodynamic (PK-PD) model mimicking a simplified bacterial life-cycle of S. aureus was developed upon time-kill curve data to describe the effects of LZD, VAN, and MER alone and in dual combinations. The PK-PD model was successfully (i) evaluated with external data from two clinical S. aureus isolates and further drug combinations and (ii) challenged to predict common clinical PK-PD indices and breakpoints. Finally, clinical trial simulations were performed that revealed that the combination of VAN-MER might be favorable over LZD-MER due to an unfavorable antagonistic interaction between LZD and MER.
Y1 - 2017
U6 - https://doi.org/10.1002/psp4.12197
SN - 2163-8306
VL - 6
SP - 512
EP - 522
PB - Wiley
CY - Hoboken
ER -
TY - JOUR
A1 - Hülscher, Julian
A1 - Sobel, Edward
A1 - Kallnik, Niklas
A1 - Hoffmann, J. Elis
A1 - Millar, Ian L.
A1 - Hartmann, Kai
A1 - Bernhardt, Anne
T1 - Apatites record sedimentary provenance change 4-5 myrs before clay in the Oligocene/Miocene Alpine molasse
JF - Frontiers in Earth Science
N2 - Extracting information about past tectonic or climatic environmental changes from sedimentary records is a key objective of provenance research. Interpreting the imprint of such changes remains challenging as signals might be altered in the sediment-routing system.
We investigate the sedimentary provenance of the Oligocene/Miocene Upper Austrian Northern Alpine Foreland Basin and its response to the tectonically driven exhumation of the Tauern Window metamorphic dome (28 +/- 1 Ma) in the Eastern European Alps by using the unprecedented combination of Nd isotopic composition of bulk-rock clay-sized samples and partly previously published multi-proxy (Nd isotopic composition, trace-element geochemistry, U-Pb dating) sand-sized apatite single-grain analysis.
The basin offers an excellent opportunity to investigate environmental signal propagation into the sedimentary record because comprehensive stratigraphic and seismic datasets can be combined with present research results. The bulk-rock clay-sized fraction epsilon Nd values of well-cutting samples from one well on the northern basin slope remained stable at similar to-9.7 from 27 to 19 Ma but increased after 19 Ma to similar to-9.1. In contrast, apatite single-grain distributions, which were extracted from 22 drill-core samples, changed significantly around 23.3 Ma from apatites dominantly from low-grade ( The detailed vegetation cover and structure information in the first two datasets are of use for ecological applications, on one hand for summergreen and evergreen needle-leaf forests and also for tundra-taiga ecotones. Datasets 1 and 2 further support the generation and validation of land cover remote-sensing products in radar and optical remote sensing. In addition to providing information on forest structure and vegetation composition of the vegetation plots, the third and fourth datasets are prepared as training and validation data for machine-learning purposes. For example, the synthetic tree-crown dataset is generated from the raw UAV images and optimized to be used in neural networks. Furthermore, the fourth SiDroForest dataset contains S-2 labeled image patches processed to a high standard that provide training data on vegetation class categories for machine-learning classification with JavaScript Object Notation (JSON) labels provided. The SiDroForest data collection adds unique insights into remote hard-to-reach circumboreal forest regions.
Y1 - 2022
U6 - https://doi.org/10.5194/essd-14-4967-2022
SN - 1866-3508
SN - 1866-3516
VL - 14
IS - 11
SP - 4967
EP - 4994
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Dietze, Elisabeth
A1 - Mangelsdorf, Kai
A1 - Andreev, Andrei
A1 - Karger, Cornelia
A1 - Schreuder, Laura T.
A1 - Hopmans, Ellen C.
A1 - Rach, Oliver
A1 - Sachse, Dirk
A1 - Wennrich, Volker
A1 - Herzschuh, Ulrike
T1 - Relationships between low-temperature fires, climate and vegetation during three late glacials and interglacials of the last 430 kyr in northeastern Siberia reconstructed from monosaccharide anhydrides in Lake El’gygytgyn sediments
JF - Climate of the Past
N2 - Landscapes in high northern latitudes are assumed to be highly sensitive to future global change, but the rates and long-term trajectories of changes are rather uncertain. In the boreal zone, fires are an important factor in climate-vegetation interactions and biogeochemical cycles. Fire regimes are characterized by small, frequent, low-intensity fires within summergreen boreal forests dominated by larch, whereas evergreen boreal forests dominated by spruce and pine burn large areas less frequently but at higher intensities. Here, we explore the potential of the monosaccharide anhydrides (MA) levoglucosan, mannosan and galactosan to serve as proxies of low-intensity biomass burning in glacial-to-interglacial lake sediments from the high northern latitudes. We use sediments from Lake El'gygytgyn (cores PG 1351 and ICDP 5011-1), located in the far north-east of Russia, and study glacial and interglacial samples of the last 430 kyr (marine isotope stages 5e, 6, 7e, 8, 11c and 12) that had different climate and biome configurations. Combined with pollen and non-pollen palynomorph records from the same samples, we assess how far the modern relationships between fire, climate and vegetation persisted during the past, on orbital to centennial timescales. We find that MAs attached to particulates were well-preserved in up to 430 kyr old sediments with higher influxes from low-intensity biomass burning in interglacials compared to glacials. MA influxes significantly increase when summergreen boreal forest spreads closer to the lake, whereas they decrease when tundra-steppe environments and, especially, Sphagnum peatlands spread. This suggests that low-temperature fires are a typical characteristic of Siberian larch forests also on long timescales. The results also suggest that low-intensity fires would be reduced by vegetation shifts towards very dry environments due to reduced biomass availability, as well as by shifts towards peatlands, which limits fuel dryness. In addition, we observed very low MA ratios, which we interpret as high contributions of galactosan and mannosan from biomass sources other than those currently monitored, such as the moss-lichen mats in the understorey of the summergreen boreal forest. Overall, sedimentary MAs can provide a powerful proxy for fire regime reconstructions and extend our knowledge of long-term natural fire-climate-vegetation feedbacks in the high northern latitudes.
KW - molecular tracers
KW - organic aerosols
KW - emission factors
KW - carbonaceous aerosols
KW - pollen records
KW - core PG1351
KW - biomass
KW - holocene
KW - levoglucosan
KW - charcoal
Y1 - 2020
U6 - https://doi.org/10.5194/cp-16-799-2020
SN - 1814-9332
SN - 1814-9324
VL - 16
IS - 2
SP - 788
EP - 818
PB - Copernicus Publications
CY - Göttingen
ER -
TY - JOUR
A1 - Miesner, Timon
A1 - Herzschuh, Ulrike
A1 - Pestryakova, Luidmila Agafyevna
A1 - Wieczorek, Mareike
A1 - Zakharov, Evgenii S.
A1 - Kolmogorov, Alexei I.
A1 - Davydova, Paraskovya V.
A1 - Kruse, Stefan
T1 - Forest structure and individual tree inventories of northeastern Siberia along climatic gradients
JF - Earth system science data : ESSD
N2 - We compile a data set of forest surveys from expeditions to the northeast of the Russian Federation, in Krasnoyarsk Krai, the Republic of Sakha (Yakutia), and the Chukotka Autonomous Okrug (59-73 degrees N, 97-169 degrees E), performed between the years 2011 and 2021. The region is characterized by permafrost soils and forests dominated by larch (Larix gmelinii Rupr. and Larix cajanderi Mayr).
Our data set consists of a plot database describing 226 georeferenced vegetation survey plots and a tree database with information about all the trees on these plots. The tree database, consisting of two tables with the same column names, contains information on the height, species, and vitality of 40 289 trees. A subset of the trees was subject to a more detailed inventory, which recorded the stem diameter at base and at breast height, crown diameter, and height of the beginning of the crown.
We recorded heights up to 28.5 m (median 2.5 m) and stand densities up to 120 000 trees per hectare (median 1197 ha(-1)), with both values tending to be higher in the more southerly areas. Observed taxa include Larix Mill., Pinus L., Picea A. Dietr., Abies Mill., Salix L., Betula L., Populus L., Alnus Mill., and Ulmus L.
In this study, we present the forest inventory data aggregated per plot. Additionally, we connect the data with different remote sensing data products to find out how accurately forest structure can be predicted from such products. Allometries were calculated to obtain the diameter from height measurements for every species group. For Larix, the most frequent of 10 species groups, allometries depended also on the stand density, as denser stands are characterized by thinner trees, relative to height. The remote sensing products used to compare against the inventory data include climate, forest biomass, canopy height, and forest loss or disturbance. We find that the forest metrics measured in the field can only be reconstructed from the remote sensing data to a limited extent, as they depend on local properties. This illustrates the need for ground inventories like those data we present here.
The data can be used for studying the forest structure of northeastern Siberia and for the calibration and validation of remotely sensed data.
Y1 - 2022
U6 - https://doi.org/10.5194/essd-14-5695-2022
SN - 1866-3508
SN - 1866-3516
VL - 14
IS - 12
SP - 5695
EP - 5716
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Kruse, Stefan
A1 - Stünzi, Simone Maria
A1 - Boike, Julia
A1 - Langer, Moritz
A1 - Gloy, Josias
A1 - Herzschuh, Ulrike
T1 - Novel coupled permafrost-forest model (LAVESI-CryoGrid v1.0) revealing the interplay between permafrost, vegetation, and climate across eastern Siberia
JF - Geoscientific model development : GMD ; an interactive open access journal of the European Geosciences Union
N2 - Boreal forests of Siberia play a relevant role in the global carbon cycle. However, global warming threatens the existence of summergreen larch-dominated ecosystems, likely enabling a transition to evergreen tree taxa with deeper active layers. Complex permafrost-vegetation interactions make it uncertain whether these ecosystems could develop into a carbon source rather than continuing atmospheric carbon sequestration under global warming. Consequently, shedding light on the role of current and future active layer dynamics and the feedbacks with the apparent tree species is crucial to predict boreal forest transition dynamics and thus for aboveground forest biomass and carbon stock developments. Hence, we established a coupled model version amalgamating a one-dimensional permafrost multilayer forest land-surface model (CryoGrid) with LAVESI, an individual-based and spatially explicit forest model for larch species (Larix Mill.), extended for this study by including other relevant Siberian forest species and explicit terrain.
Following parameterization, we ran simulations with the coupled version to the near future to 2030 with a mild climate-warming scenario. We focus on three regions covering a gradient of summergreen forests in the east at Spasskaya Pad, mixed summergreen-evergreen forests close to Nyurba, and the warmest area at Lake Khamra in the southeast of Yakutia, Russia. Coupled simulations were run with the newly implemented boreal forest species and compared to runs allowing only one species at a time, as well as to simulations using just LAVESI. Results reveal that the coupled version corrects for overestimation of active layer thickness (ALT) and soil moisture, and large differences in established forests are simulated. We conclude that the coupled version can simulate the complex environment of eastern Siberia by reproducing vegetation patterns, making it an excellent tool to disentangle processes driving boreal forest dynamics.
Y1 - 2022
U6 - https://doi.org/10.5194/gmd-15-2395-2022
SN - 1991-959X
SN - 1991-9603
VL - 15
IS - 6
SP - 2395
EP - 2422
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Radosavljevic, Boris
A1 - Lantuit, Hugues
A1 - Knoblauch, Christian
A1 - Couture, Nicole
A1 - Herzschuh, Ulrike
A1 - Fritz, Michael
T1 - Arctic nearshore sediment dynamics - an example from Herschel Island - Qikiqtaruk, Canada
JF - Journal of marine science and engineering
N2 - Increasing arctic coastal erosion rates imply a greater release of sediments and organic matter into the coastal zone. With 213 sediment samples taken around Herschel Island-Qikiqtaruk, Canadian Beaufort Sea, we aimed to gain new insights on sediment dynamics and geochemical properties of a shallow arctic nearshore zone. Spatial characteristics of nearshore sediment texture (moderately to poorly sorted silt) are dictated by hydrodynamic processes, but ice-related processes also play a role. We determined organic matter (OM) distribution and inferred the origin and quality of organic carbon by C/N ratios and stable carbon isotopes delta C-13. The carbon content was higher offshore and in sheltered areas (mean: 1.0 wt.%., S.D.: 0.9) and the C/N ratios also showed a similar spatial pattern (mean: 11.1, S.D.: 3.1), while the delta C-13 (mean: -26.4 parts per thousand VPDB, S.D.: 0.4) distribution was more complex. We compared the geochemical parameters of our study with terrestrial and marine samples from other studies using a bootstrap approach. Sediments of the current study contained 6.5 times and 1.8 times less total organic carbon than undisturbed and disturbed terrestrial sediments, respectively. Therefore, degradation of OM and separation of carbon pools take place on land and continue in the nearshore zone, where OM is leached, mineralized, or transported beyond the study area.
KW - permafrost
KW - Arctic Ocean
KW - stable carbon isotopes
KW - nitrogen
KW - sediment
KW - chemistry
KW - sediment dynamics
KW - Beaufort Sea
KW - grain size
Y1 - 2022
U6 - https://doi.org/10.3390/jmse10111589
SN - 2077-1312
VL - 10
IS - 11
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Dallmeyer, Anne
A1 - Kleinen, Thomas
A1 - Claussen, Martin
A1 - Weitzel, Nils
A1 - Cao, Xianyong
A1 - Herzschuh, Ulrike
T1 - The deglacial forest conundrum
JF - Nature Communications
N2 - How fast the Northern Hemisphere (NH) forest biome tracks strongly warming climates is largely unknown. Regional studies reveal lags between decades and millennia. Here we report a conundrum: Deglacial forest expansion in the NH extra-tropics occurs approximately 4000 years earlier in a transient MPI-ESM1.2 simulation than shown by pollen-based biome reconstructions. Shortcomings in the model and the reconstructions could both contribute to this mismatch, leaving the underlying causes unresolved. The simulated vegetation responds within decades to simulated climate changes, which agree with pollen-independent reconstructions. Thus, we can exclude climate biases as main driver for differences. Instead, the mismatch points at a multi-millennial disequilibrium of the NH forest biome to the climate signal. Therefore, the evaluation of time-slice simulations in strongly changing climates with pollen records should be critically reassessed. Our results imply that NH forests may be responding much slower to ongoing climate changes than Earth System Models predict.
Deglacial forest expansion in the Northern Hemisphere poses a conundrum: Model results agree with the climate signal but are several millennia ahead of reconstructed forest dynamics. The underlying causes remain unsolved.
Y1 - 2022
U6 - https://doi.org/10.1038/s41467-022-33646-6
SN - 2041-1723
VL - 13
IS - 1
PB - Nature Publishing Group UK
CY - [London]
ER -
TY - JOUR
A1 - Kruse, Stefan
A1 - Herzschuh, Ulrike
T1 - Regional opportunities for tundra conservation in the next 1000 years
JF - eLife
N2 - The biodiversity of tundra areas in northern high latitudes is threatened by invasion of forests under global warming. However, poorly understood nonlinear responses of the treeline ecotone mean the timing and extent of tundra losses are unclear, but policymakers need such information to optimize conservation efforts. Our individual-based model LAVESI, developed for the Siberian tundra-taiga ecotone, can help improve our understanding. Consequently, we simulated treeline migration trajectories until the end of the millennium, causing a loss of tundra area when advancing north. Our simulations reveal that the treeline follows climate warming with a severe, century-long time lag, which is overcompensated by infilling of stands in the long run even when temperatures cool again. Our simulations reveal that only under ambitious mitigation strategies (relative concentration pathway 2.6) will ~30% of original tundra areas remain in the north but separated into two disjunct refugia.
KW - Larix gmelinii
KW - Larix cajanderi
KW - nonlinear response
KW - treeline ecotone
KW - tundra
KW - Ecology
KW - Short Report
Y1 - 2022
U6 - https://doi.org/10.7554/eLife.75163
SN - 2050-084X
VL - 11
PB - eLife Sciences Publications
CY - Cambridge
ER -
TY - JOUR
A1 - Li, Chenzhi
A1 - Postl, Alexander K.
A1 - Böhmer, Thomas
A1 - Cao, Xianyong
A1 - Dolman, Andrew M.
A1 - Herzschuh, Ulrike
T1 - Harmonized chronologies of a global late Quaternary pollen dataset (LegacyAge 1.0)
JF - Earth system science data : ESSD
N2 - We present a chronology framework named LegacyAge 1.0 containing harmonized chronologies for 2831 pollen records (downloaded from the Neotoma Paleoecology Database and the supplementary Asian datasets) together with their age control points and metadata in machine-readable data formats.
All chronologies use the Bayesian framework implemented in Bacon version 2.5.3. Optimal parameter settings of priors (accumulation.shape, memory.strength, memory.mean, accumulation.rate, and thickness) were identified based on information in the original publication or iteratively after preliminary model inspection.
The most common control points for the chronologies are radiocarbon dates (86.1 %), calibrated by the latest calibration curves (IntCal20 and SHCal20 for the terrestrial radiocarbon dates in the Northern Hemisphere and Southern Hemisphere and Marine20 for marine materials).
The original publications were consulted when dealing with outliers and inconsistencies. Several major challenges when setting up the chronologies included the waterline issue (18.8% of records), reservoir effect (4.9 %), and sediment deposition discontinuity (4.4 %).
Finally, we numerically compare the LegacyAge 1.0 chronologies to those published in the original publications and show that the reliability of the chronologies of 95.4% of records could be improved according to our assessment.
Our chronology framework and revised chronologies provide the opportunity to make use of the ages and age uncertainties in synthesis studies of, for example, pollen-based vegetation and climate change.
The LegacyAge 1.0 dataset, including metadata, datings, harmonized chronologies, and R code used, is openaccess and available at PANGAEA (https://doi.org/10.1594/PANGAEA.933132; Li et al., 2021) and Zenodo (https://doi.org/10.5281/zenodo.5815192; Li et al., 2022), respectively.
Y1 - 2022
U6 - https://doi.org/10.5194/essd-14-1331-2022
SN - 1866-3508
SN - 1866-3516
VL - 14
IS - 3
SP - 1331
EP - 1343
PB - Copernics Publications
CY - Katlenburg-Lindau
ER -
TY - JOUR
A1 - Courtin, Jérémy
A1 - Andreev, Andrei
A1 - Raschke, Elena
A1 - Bala, Sarah
A1 - Biskaborn, Boris
A1 - Liu, Sisi
A1 - Zimmermann, Heike
A1 - Diekmann, Bernhard
A1 - Stoof-Leichsenring, Kathleen R.
A1 - Pestryakova, Luidmila Agafyevna
A1 - Herzschuh, Ulrike
T1 - Vegetation changes in Southeastern Siberia during the late pleistocene and the holocene
JF - Frontiers in Ecology and Evolution
N2 - Relationships between climate, species composition, and species richness are of particular importance for understanding how boreal ecosystems will respond to ongoing climate change. This study aims to reconstruct changes in terrestrial vegetation composition and taxa richness during the glacial Late Pleistocene and the interglacial Holocene in the sparsely studied southeastern Yakutia (Siberia) by using pollen and sedimentary ancient DNA (sedaDNA) records. Pollen and sedaDNA metabarcoding data using the trnL g and h markers were obtained from a sediment core from Lake Bolshoe Toko. Both proxies were used to reconstruct the vegetation composition, while metabarcoding data were also used to investigate changes in plant taxa richness. The combination of pollen and sedaDNA approaches allows a robust estimation of regional and local past terrestrial vegetation composition around Bolshoe Toko during the last similar to 35,000 years. Both proxies suggest that during the Late Pleistocene, southeastern Siberia was covered by open steppe-tundra dominated by graminoids and forbs with patches of shrubs, confirming that steppe-tundra extended far south in Siberia. Both proxies show disturbance at the transition between the Late Pleistocene and the Holocene suggesting a period with scarce vegetation, changes in the hydrochemical conditions in the lake, and in sedimentation rates. Both proxies document drastic changes in vegetation composition in the early Holocene with an increased number of trees and shrubs and the appearance of new tree taxa in the lake's vicinity. The sedaDNA method suggests that the Late Pleistocene steppe-tundra vegetation supported a higher number of terrestrial plant taxa than the forested Holocene. This could be explained, for example, by the "keystone herbivore" hypothesis, which suggests that Late Pleistocene megaherbivores were able to maintain a high plant diversity. This is discussed in the light of the data with the broadly accepted species-area hypothesis as steppe-tundra covered such an extensive area during the Late Pleistocene.
KW - last glacial
KW - Holocene
KW - Lake Bolshoe Toko
KW - paleoenvironments
KW - sedimentary ancient DNA
KW - metabarcoding
KW - trnL
KW - pollen
Y1 - 2021
U6 - https://doi.org/10.3389/fevo.2021.625096
SN - 2296-701X
VL - 9
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Heim, Birgit
A1 - Lisovski, Simeon
A1 - Wieczorek, Mareike
A1 - Morgenstern, Anne
A1 - Juhls, Bennet
A1 - Shevtsova, Iuliia
A1 - Kruse, Stefan
A1 - Boike, Julia
A1 - Fedorova, Irina
A1 - Herzschuh, Ulrike
T1 - Spring snow cover duration and tundra greenness in the Lena Delta, Siberia
BT - two decades of MODIS satellite time series (2001-2021)
JF - Environmental research letters
N2 - The Lena Delta in Siberia is the largest delta in the Arctic and as a snow-dominated ecosystem particularly vulnerable to climate change.
Using the two decades of MODerate resolution Imaging Spectroradiometer satellite acquisitions, this study investigates interannual and spatial variability of snow-cover duration and summer vegetation vitality in the Lena Delta.
We approximated snow by the application of the normalized difference snow index and vegetation greenness by the normalized difference vegetation index (NDVI). We consolidated the analyses by integrating reanalysis products on air temperature from 2001 to 2021, and air temperature, ground temperature, and the date of snow-melt from time-lapse camera (TLC) observations from the Samoylov observatory located in the central delta.
We extracted spring snow-cover duration determined by a latitudinal gradient. The 'regular year' snow-melt is transgressing from mid-May to late May within a time window of 10 days across the delta.
We calculated yearly deviations per grid cell for two defined regions, one for the delta, and one focusing on the central delta. We identified an ensemble of early snow-melt years from 2012 to 2014, with snow-melt already starting in early May, and two late snow-melt years in 2004 and 2017, with snow-melt starting in June. In the times of TLC recording, the years of early and late snow-melt were confirmed.
In the three summers after early snow-melt, summer vegetation greenness showed neither positive nor negative deviations. Whereas, vegetation greenness was reduced in 2004 after late snow-melt together with the lowest June monthly air temperature of the time series record. Since 2005, vegetation greenness is rising, with maxima in 2018 and 2021.
The NDVI rise since 2018 is preceded by up to 4 degrees C warmer than average June air temperature. The ongoing operation of satellite missions allows to monitor a wide range of land surface properties and processes that will provide urgently needed data in times when logistical challenges lead to data gaps in land-based observations in the rapidly changing Arctic.
KW - Arctic vegetation
KW - tundra
KW - snow cover duration
KW - NDVI
KW - NDSI
KW - MODIS
KW - Lena Delta
Y1 - 2022
U6 - https://doi.org/10.1088/1748-9326/ac8066
SN - 1748-9326
VL - 17
IS - 8
PB - IOP Publ. Ltd.
CY - Bristol
ER -
TY - JOUR
A1 - Herzschuh, Ulrike
A1 - Li, Chenzhi
A1 - Boehmer, Thomas
A1 - Postl, Alexander K.
A1 - Heim, Birgit
A1 - Andreev, Andrei A.
A1 - Cao, Xianyong
A1 - Wieczorek, Mareike
A1 - Ni, Jian
T1 - LegacyPollen 1.0
BT - a taxonomically harmonized global late Quaternary pollen dataset of 2831 records with standardized chronologies
JF - Earth system science data : ESSD
N2 - Here we describe the LegacyPollen 1.0, a dataset of 2831 fossil pollen records with metadata, a harmonized taxonomy, and standardized chronologies.
A total of 1032 records originate from North America, 1075 from Europe, 488 from Asia, 150 from Latin America, 54 from Africa, and 32 from the Indo-Pacific.
The pollen data cover the late Quaternary (mostly the Holocene). The original 10 110 pollen taxa names (including variations in the notations) were harmonized to 1002 terrestrial taxa (including Cyperaceae), with woody taxa and major herbaceous taxa harmonized to genus level and other herbaceous taxa to family level.
The dataset is valuable for synthesis studies of, for example, taxa areal changes, vegetation dynamics, human impacts (e.g., deforestation), and climate change at global or continental scales.
The harmonized pollen and metadata as well as the harmonization table are available from PANGAEA (https://doi.org/10.1594/PANGAEA.929773; Herzschuh et al., 2021). R code for the harmonization is provided at Zenodo (https://doi.org/10.5281/zenodo.5910972; Herzschuh et al., 2022) so that datasets at a customized harmonization level can be easily established.
Y1 - 2022
U6 - https://doi.org/10.5194/essd-14-3213-2022
SN - 1866-3508
SN - 1866-3516
VL - 14
IS - 7
SP - 3213
EP - 3227
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Weinelt, Ferdinand Anton
A1 - Stegemann, Miriam Songa
A1 - Theloe, Anja
A1 - Pfäfflin, Frieder
A1 - Achterberg, Stephan
A1 - Weber, Franz
A1 - Dübel, Lucas
A1 - Mikolajewska, Agata
A1 - Uhrig, Alexander
A1 - Kiessling, Peggy
A1 - Huisinga, Wilhelm
A1 - Michelet, Robin
A1 - Hennig, Stefanie
A1 - Kloft, Charlotte
T1 - Evaluation of a meropenem and piperacillin monitoring program in intensive care unit patients calls for the regular assessment of empirical targets and easy-to-use dosing decision tools
JF - Antibiotics : open access journal
N2 - The drug concentrations targeted in meropenem and piperacillin/tazobactam therapy also depend on the susceptibility of the pathogen. Yet, the pathogen is often unknown, and antibiotic therapy is guided by empirical targets. To reliably achieve the targeted concentrations, dosing needs to be adjusted for renal function. We aimed to evaluate a meropenem and piperacillin/tazobactam monitoring program in intensive care unit (ICU) patients by assessing (i) the adequacy of locally selected empirical targets, (ii) if dosing is adequately adjusted for renal function and individual target, and (iii) if dosing is adjusted in target attainment (TA) failure. In a prospective, observational clinical trial of drug concentrations, relevant patient characteristics and microbiological data (pathogen, minimum inhibitory concentration (MIC)) for patients receiving meropenem or piperacillin/tazobactam treatment were collected. If the MIC value was available, a target range of 1-5 x MIC was selected for minimum drug concentrations of both drugs. If the MIC value was not available, 8-40 mg/L and 16-80 mg/L were selected as empirical target ranges for meropenem and piperacillin, respectively. A total of 356 meropenem and 216 piperacillin samples were collected from 108 and 96 ICU patients, respectively. The vast majority of observed MIC values was lower than the empirical target (meropenem: 90.0%, piperacillin: 93.9%), suggesting empirical target value reductions. TA was found to be low (meropenem: 35.7%, piperacillin 50.5%) with the lowest TA for severely impaired renal function (meropenem: 13.9%, piperacillin: 29.2%), and observed drug concentrations did not significantly differ between patients with different targets, indicating dosing was not adequately adjusted for renal function or target. Dosing adjustments were rare for both drugs (meropenem: 6.13%, piperacillin: 4.78%) and for meropenem irrespective of TA, revealing that concentration monitoring alone was insufficient to guide dosing adjustment. Empirical targets should regularly be assessed and adjusted based on local susceptibility data. To improve TA, scientific knowledge should be translated into easy-to-use dosing strategies guiding antibiotic dosing.
KW - meropenem
KW - piperacillin/tazobactam
KW - antimicrobial stewardship
KW - critically ill
KW - antibiotics
KW - pharmacokinetic/pharmacodynamic
Y1 - 2022
U6 - https://doi.org/10.3390/antibiotics11060758
SN - 2079-6382
VL - 11
IS - 6
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Ehmann, Lisa
A1 - Zoller, Michael
A1 - Minichmayr, Iris K.
A1 - Scharf, Christina
A1 - Maier, Barbara
A1 - Schmitt, Maximilian V.
A1 - Hartung, Niklas
A1 - Huisinga, Wilhelm
A1 - Vogeser, Michael
A1 - Frey, Lorenz
A1 - Zander, Johannes
A1 - Kloft, Charlotte
T1 - Role of renal function in risk assessment of target non-attainment after standard dosing of meropenem in critically ill patients
BT - a prospective observational study
JF - Critical care
N2 - Background: Severe bacterial infections remain a major challenge in intensive care units because of their high prevalence and mortality. Adequate antibiotic exposure has been associated with clinical success in critically ill patients. The objective of this study was to investigate the target attainment of standard meropenem dosing in a heterogeneous critically ill population, to quantify the impact of the full renal function spectrum on meropenem exposure and target attainment, and ultimately to translate the findings into a tool for practical application. Methods: A prospective observational single-centre study was performed with critically ill patients with severe infections receiving standard dosing of meropenem. Serial blood samples were drawn over 4 study days to determine meropenem serum concentrations. Renal function was assessed by creatinine clearance according to the Cockcroft and Gault equation (CLCRCG). Variability in meropenem serum concentrations was quantified at the middle and end of each monitored dosing interval. The attainment of two pharmacokinetic/pharmacodynamic targets (100% T->MIC, 50% T->4xMIC) was evaluated for minimum inhibitory concentration (MIC) values of 2 mg/L and 8 mg/L and standard meropenem dosing (1000 mg, 30-minute infusion, every 8 h). Furthermore, we assessed the impact of CLCRCG on meropenem concentrations and target attainment and developed a tool for risk assessment of target non-attainment. Results: Large inter-and intra-patient variability in meropenem concentrations was observed in the critically ill population (n = 48). Attainment of the target 100% T->MIC was merely 48.4% and 20.6%, given MIC values of 2 mg/L and 8 mg/L, respectively, and similar for the target 50% T->4xMIC. A hyperbolic relationship between CLCRCG (25-255 ml/minute) and meropenem serum concentrations at the end of the dosing interval (C-8h) was derived. For infections with pathogens of MIC 2 mg/L, mild renal impairment up to augmented renal function was identified as a risk factor for target non-attainment (for MIC 8 mg/L, additionally, moderate renal impairment). Conclusions: The investigated standard meropenem dosing regimen appeared to result in insufficient meropenem exposure in a considerable fraction of critically ill patients. An easy-and free-to-use tool (the MeroRisk Calculator) for assessing the risk of target non-attainment for a given renal function and MIC value was developed.
KW - beta-Lactam
KW - Intensive care
KW - Pharmacokinetics/Pharmacodynamics
KW - Target attainment
KW - Renal function
KW - Risk assessment tool
KW - Continuous renal replacement therapy
Y1 - 2017
U6 - https://doi.org/10.1186/s13054-017-1829-4
SN - 1466-609X
SN - 1364-8535
VL - 21
PB - BioMed Central
CY - London
ER -
TY - JOUR
A1 - Stachanow, Viktoria
A1 - Neumann, Uta
A1 - Blankenstein, Oliver
A1 - Bindellini, Davide
A1 - Melin, Johanna
A1 - Ross, Richard
A1 - Whitaker, Martin J. J.
A1 - Huisinga, Wilhelm
A1 - Michelet, Robin
A1 - Kloft, Charlotte
T1 - Exploring dried blood spot cortisol concentrations as an alternative for monitoring pediatric adrenal insufficiency patients
BT - a model-based analysis
JF - Frontiers in pharmacology
N2 - Congenital adrenal hyperplasia (CAH) is the most common form of adrenal insufficiency in childhood; it requires cortisol replacement therapy with hydrocortisone (HC, synthetic cortisol) from birth and therapy monitoring for successful treatment. In children, the less invasive dried blood spot (DBS) sampling with whole blood including red blood cells (RBCs) provides an advantageous alternative to plasma sampling.
Potential differences in binding/association processes between plasma and DBS however need to be considered to correctly interpret DBS measurements for therapy monitoring. While capillary DBS samples would be used in clinical practice, venous cortisol DBS samples from children with adrenal insufficiency were analyzed due to data availability and to directly compare and thus understand potential differences between venous DBS and plasma. A previously published HC plasma pharmacokinetic (PK) model was extended by leveraging these DBS concentrations.
In addition to previously characterized binding of cortisol to albumin (linear process) and corticosteroid-binding globulin (CBG; saturable process), DBS data enabled the characterization of a linear cortisol association with RBCs, and thereby providing a quantitative link between DBS and plasma cortisol concentrations. The ratio between the observed cortisol plasma and DBS concentrations varies highly from 2 to 8. Deterministic simulations of the different cortisol binding/association fractions demonstrated that with higher blood cortisol concentrations, saturation of cortisol binding to CBG was observed, leading to an increase in all other cortisol binding fractions.
In conclusion, a mathematical PK model was developed which links DBS measurements to plasma exposure and thus allows for quantitative interpretation of measurements of DBS samples.
KW - adrenal insufficiency
KW - cortisol
KW - dried blood spots
KW - pediatrics
KW - pharmacokinetics
KW - binding
KW - association
KW - red blood cells
Y1 - 2022
U6 - https://doi.org/10.3389/fphar.2022.819590
SN - 1663-9812
VL - 13
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Abiuso, Paolo
A1 - Holubec, Viktor
A1 - Anders, Janet
A1 - Ye, Zhuolin
A1 - Cerisola, Federico
A1 - Perarnau-Llobet, Marti
T1 - Thermodynamics and optimal protocols of multidimensional quadratic Brownian systems
JF - Journal of physics communications
N2 - We characterize finite-time thermodynamic processes of multidimensional quadratic overdamped systems.
Analytic expressions are provided for heat, work, and dissipation for any evolution of the system covariance matrix.
The Bures-Wasserstein metric between covariance matrices naturally emerges as the local quantifier of dissipation.
General principles of how to apply these geometric tools to identify optimal protocols are discussed.
Focusing on the relevant slow-driving limit, we show how these results can be used to analyze cases in which the experimental control over the system is partial.
KW - stochastic thermodynamics
KW - thermodynamic control
KW - thermodynamic length
KW - overdamped brownian systems
Y1 - 2022
U6 - https://doi.org/10.1088/2399-6528/ac72f8
SN - 2399-6528
VL - 6
IS - 6
PB - IOP Publ. Ltd.
CY - Bristol
ER -
TY - JOUR
A1 - Glückler, Ramesh
A1 - Herzschuh, Ulrike
A1 - Kruse, Stefan
A1 - Andreev, Andrei
A1 - Vyse, Stuart Andrew
A1 - Winkler, Bettina
A1 - Biskaborn, Boris
A1 - Pestryakova, Luidmila Agafyevna
A1 - Dietze, Elisabeth
T1 - Wildfire history of the boreal forest of south-western Yakutia (Siberia) over the last two millennia documented by a lake-sediment charcoal record
JF - Biogeosciences : BG / European Geosciences Union
N2 - Wildfires, as a key disturbance in forest ecosystems, are shaping the world's boreal landscapes. Changes in fire regimes are closely linked to a wide array of environmental factors, such as vegetation composition, climate change, and human activity. Arctic and boreal regions and, in particular, Siberian boreal forests are experiencing rising air and ground temperatures with the subsequent degradation of permafrost soils leading to shifts in tree cover and species composition. Compared to the boreal zones of North America or Europe, little is known about how such environmental changes might influence long-term fire regimes in Russia. The larch-dominated eastern Siberian deciduous boreal forests differ markedly from the composition of other boreal forests, yet data about past fire regimes remain sparse. Here, we present a high-resolution macroscopic charcoal record from lacustrine sediments of Lake Khamra (southwest Yakutia, Siberia) spanning the last ca. 2200 years, including information about charcoal particle sizes and morphotypes. Our results reveal a phase of increased charcoal accumulation between 600 and 900 CE, indicative of relatively high amounts of burnt biomass and high fire frequencies. This is followed by an almost 900-year-long period of low charcoal accumulation without significant peaks likely corresponding to cooler climate conditions. After 1750 CE fire frequencies and the relative amount of biomass burnt start to increase again, coinciding with a warming climate and increased anthropogenic land development after Russian colonization. In the 20th century, total charcoal accumulation decreases again to very low levels despite higher fire frequency, potentially reflecting a change in fire management strategies and/or a shift of the fire regime towards more frequent but smaller fires. A similar pattern for different charcoal morphotypes and comparison to a pollen and non-pollen palynomorph (NPP) record from the same sediment core indicate that broad-scale changes in vegetation composition were probably not a major driver of recorded fire regime changes. Instead, the fire regime of the last two millennia at Lake Khamra seems to be controlled mainly by a combination of short-term climate variability and anthropogenic fire ignition and suppression.
Y1 - 2021
U6 - https://doi.org/10.5194/bg-18-4185-2021
SN - 1726-4170
SN - 1726-4189
VL - 18
IS - 13
SP - 4185
EP - 4209
PB - Copernicus
CY - Göttingen
ER -
TY - JOUR
A1 - Glückler, Ramesh
A1 - Geng, Rongwei
A1 - Grimm, Lennart
A1 - Baisheva, Izabella
A1 - Herzschuh, Ulrike
A1 - Stoof-Leichsenring, Kathleen R.
A1 - Kruse, Stefan
A1 - Andreev, Andrej Aleksandrovic
A1 - Pestryakova, Luidmila
A1 - Dietze, Elisabeth
T1 - Holocene wildfire and vegetation dynamics in Central Yakutia, Siberia, reconstructed from lake-sediment proxies
JF - Frontiers in Ecology and Evolution
N2 - Wildfires play an essential role in the ecology of boreal forests.
In eastern Siberia, fire activity has been increasing in recent years, challenging the livelihoods of local communities. Intensifying fire regimes also increase disturbance pressure on the boreal forests, which currently protect the permafrost beneath from accelerated degradation.
However, long-term relationships between changes in fire regime and forest structure remain largely unknown.
We assess past fire-vegetation feedbacks using sedimentary proxy records from Lake Satagay, Central Yakutia, Siberia, covering the past c. 10,800 years.
Results from macroscopic and microscopic charcoal analyses indicate high amounts of burnt biomass during the Early Holocene, and that the present-day, low-severity surface fire regime has been in place since c. 4,500 years before present.
A pollen-based quantitative reconstruction of vegetation cover and a terrestrial plant record based on sedimentary ancient DNA metabarcoding suggest a pronounced shift in forest structure toward the Late Holocene.
Whereas the Early Holocene was characterized by postglacial open larch-birch woodlands, forest structure changed toward the modern, mixed larch-dominated closed-canopy forest during the Mid-Holocene.
We propose a potential relationship between open woodlands and high amounts of burnt biomass, as well as a mediating effect of dense larch forest on the climate-driven intensification of fire regimes.
Considering the anticipated increase in forest disturbances (droughts, insect invasions, and wildfires), higher tree mortality may force the modern state of the forest to shift toward an open woodland state comparable to the Early Holocene.
Such a shift in forest structure may result in a positive feedback on currently intensifying wildfires.
These new long-term data improve our understanding of millennial-scale fire regime changes and their relationships to changes of vegetation in Central Yakutia, where the local population is already being confronted with intensifying wildfire seasons.
KW - fire
KW - larch
KW - boreal
KW - forest
KW - Russia
KW - charcoal
KW - pollen
KW - ancient DNA
Y1 - 2022
U6 - https://doi.org/10.3389/fevo.2022.962906
SN - 2296-701X
VL - 10
PB - Frontiers Media
CY - Lausanne
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 - Inceoglu, Fadil
A1 - Shprits, Yuri Y.
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 - Chaabene, Helmi
A1 - Markov, Adrian
A1 - Prieske, Olaf
A1 - Moran, Jason
A1 - Behrens, Martin
A1 - Negra, Yassine
A1 - Ramirez-Campillo, Rodrigo
A1 - Koch, Ulrike
A1 - Mkaouer, Bessem
T1 - Effect of flywheel versus traditional resistance training on change of direction performance in male athletes
BT - a systematic review with meta-analysis
JF - International journal of environmental research and public health : IJERPH
N2 - Objective:
This study aimed to systematically review and meta-analyze the effect of flywheel resistance training (FRT) versus traditional resistance training (TRT) on change of direction (CoD) performance in male athletes.
Methods:
Five databases were screened up to December 2021.
Results:
Seven studies were included. The results indicated a significantly larger effect of FRT compared with TRT (standardized mean difference [SMD] = 0.64). A within-group comparison indicated a significant large effect of FRT on CoD performance (SMD = 1.63). For TRT, a significant moderate effect was observed (SMD = 0.62). FRT of <= 2 sessions/week resulted in a significant large effect (SMD = 1.33), whereas no significant effect was noted for >2 sessions/week. Additionally, a significant large effect of <= 12 FRT sessions (SMD = 1.83) was observed, with no effect of >12 sessions. Regarding TRT, no significant effects of any of the training factors were detected (p > 0.05).
Conclusions:
FRT appears to be more effective than TRT in improving CoD performance in male athletes. Independently computed single training factor analyses for FRT indicated that <= 2 sessions/week resulted in a larger effect on CoD performance than >2 sessions/week. Additionally, a total of <= 12 FRT sessions induced a larger effect than >12 training sessions. Practitioners in sports, in which accelerative and decelerative actions occur in quick succession to change direction, should regularly implement FRT.
KW - human physical conditioning
KW - eccentric training
KW - strength training
KW - athletes
KW - sports
KW - muscle strength
Y1 - 2022
U6 - https://doi.org/10.3390/ijerph19127061
SN - 1661-7827
SN - 1660-4601
VL - 19
IS - 12
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Liu, Sisi
A1 - Stoof-Leichsenring, Kathleen Rosemarie
A1 - Kruse, Stefan
A1 - Pestryakova, Luidmila Agafyevna
A1 - Herzschuh, Ulrike
T1 - Holocene vegetation and plant diversity changes in the north-eastern Siberian treeline region from pollen and sedimentary ancient DNA
JF - Frontiers in Ecology and Evolution
N2 - Although sedimentary ancient DNA (sedaDNA) has been increasingly used to study paleoecological dynamics (Schulte et al., 2020), the approach has rarely been compared with the traditional method of pollen analysis for investigating past changes in the vegetation composition and diversity of Arctic treeline areas. Here, we provide a history of latitudinal floristic composition and species diversity based on a comparison ofsedaDNA and pollen data archived in three Siberian lake sediment cores spanning the mid-Holocene to the present (7.6-0 cal ka BP), from northern typical tundra to southern open larch forest in the Omoloy region. Our results show that thesedaDNA approach identifies more plant taxa found in the local vegetation communities, while the corresponding pollen analysis mainly captures the regional vegetation development and has its limitations for plant diversity reconstruction. Measures of alpha diversity were calculated based onsedaDNA data recovered from along a tundra to forest tundra to open larch forest gradient. Across all sites,sedaDNA archives provide a complementary record of the vegetation transition within each lake's catchment, tracking a distinct latitudinal vegetation type range from larch tree/alder shrub (open larch forest site) to dwarf shrub-steppe (forest tundra) to wet sedge tundra (typical tundra site). By contrast, the pollen data reveal an open landscape, which cannot distinguish the temporal changes in compositional vegetation for the open larch forest site and forest-tundra site. IncreasingLarixpollen percentages were recorded in the forest-tundra site in the last millenium although noLarixDNA was detected, suggesting that thesedaDNA approach performs better for tracking the local establishment ofLarix. Highest species richness and diversity are found in the mid-Holocene (before 4.4 ka) at the typical tundra site with a diverse range of vegetational habitats, while lowest species richness is recorded for the forest tundra where dwarf-willow habitats dominated the lake's catchment. During the late Holocene, strong declines in species richness and diversity are found at the typical tundra site with the vegetation changing to relatively simple communities. Nevertheless, plant species richness is mostly higher than at the forest-tundra site, which shows a slightly decreasing trend. Plant species richness at the open larch forest site fluctuates through time and is higher than the other sites since around 2.5 ka. Taken together, there is no evidence to suggest that the latitudinal gradients in species diversity changes are present at a millennial scale. Additionally, a weak correlation between the principal component analysis (PCA) site scores ofsedaDNA and species richness suggests that climate may not be a direct driver of species turnover within a lake's catchment. Our data suggest thatsedaDNA and pollen have different but complementary abilities for reconstructing past vegetation and species diversity along a latitude.
KW - sedimentary ancient DNA
KW - metabarcoding
KW - pollen
KW - Siberia
KW - palaeovegetation
KW - plant diversity
KW - latitudinal gradient
Y1 - 2020
U6 - https://doi.org/10.3389/fevo.2020.560243
SN - 2296-701X
VL - 8
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Huang, Sichao
A1 - Stoof-Leichsenring, Kathleen R.
A1 - Liu, Sisi
A1 - Courtin, Jeremy
A1 - Andreev, Andrej A.
A1 - Pestryakova, Luidmila. A.
A1 - Herzschuh, Ulrike
T1 - Plant sedimentary ancient DNA from Far East Russia covering the last 28,000 years reveals different assembly rules in cold and warm climates
JF - Frontiers in Ecology and Evolution
N2 - Woody plants are expanding into the Arctic in response to the warming climate. The impact on arctic plant communities is not well understood due to the limited knowledge about plant assembly rules.
Records of past plant diversity over long time series are rare. Here, we applied sedimentary ancient DNA metabarcoding targeting the P6 loop of the chloroplast trnL gene to a sediment record from Lake Ilirney (central Chukotka, Far Eastern Russia) covering the last 28 thousand years.
Our results show that forb-rich steppe-tundra and dwarf-shrub tundra dominated during the cold climate before 14 ka, while deciduous erect-shrub tundra was abundant during the warm period since 14 ka. Larix invasion during the late Holocene substantially lagged behind the likely warmest period between 10 and 6 ka, where the vegetation biomass could be highest.
We reveal highest richness during 28-23 ka and a second richness peak during 13-9 ka, with both periods being accompanied by low relative abundance of shrubs. During the cold period before 14 ka, rich plant assemblages were phylogenetically clustered, suggesting low genetic divergence in the assemblages despite the great number of species. This probably originates from environmental filtering along with niche differentiation due to limited resources under harsh environmental conditions. In contrast, during the warmer period after 14 ka, rich plant assemblages were phylogenetically overdispersed.
This results from a high number of species which were found to harbor high genetic divergence, likely originating from an erratic recruitment process in the course of warming. Some of our evidence may be of relevance for inferring future arctic plant assembly rules and diversity changes. By analogy to the past, we expect a lagged response of tree invasion. Plant richness might overshoot in the short term; in the long-term, however, the ongoing expansion of deciduous shrubs will eventually result in a phylogenetically more diverse community.
KW - sedimentary ancient DNA (sedaDNA)
KW - metabarcoding
KW - phylogenetic and taxonomic plant diversity
KW - Arctic Russia
KW - Siberia
KW - holocene
KW - glacial
KW - treeline
Y1 - 2021
U6 - https://doi.org/10.3389/fevo.2021.763747
SN - 2296-701X
VL - 9
PB - Frontiers Media
CY - Lausanne
ER -
TY - JOUR
A1 - Cao, Xianyong
A1 - Tian, Fang
A1 - Andreev, Andrei
A1 - Anderson, Patricia M.
A1 - Lozhkin, Anatoly V.
A1 - Bezrukova, Elena
A1 - Ni, Jian
A1 - Rudaya, Natalia
A1 - Stobbe, Astrid
A1 - Wieczorek, Mareike
A1 - Herzschuh, Ulrike
T1 - A taxonomically harmonized and temporally standardized fossil pollen dataset from Siberia covering the last 40 kyr
JF - Earth System Science Data
N2 - Pollen records from Siberia are mostly absent in global or Northern Hemisphere synthesis works. Here we present a taxonomically harmonized and temporally standardized pollen dataset that was synthesized using 173 palynological records from Siberia and adjacent areas (northeastern Asia, 42-75 degrees N, 50-180 degrees E). Pollen data were taxonomically harmonized, i.e. the original 437 taxa were assigned to 106 combined pollen taxa. Age-depth models for all records were revised by applying a constant Bayesian age-depth modelling routine. The pollen dataset is available as count data and percentage data in a table format (taxa vs. samples), with age information for each sample. The dataset has relatively few sites covering the last glacial period between 40 and 11.5 ka (calibrated thousands of years before 1950 CE) particularly from the central and western part of the study area. In the Holocene period, the dataset has many sites from most of the area, with the exception of the central part of Siberia. Of the 173 pollen records, 81 % of pollen counts were downloaded from open databases (GPD, EPD, PANGAEA) and 10 % were contributions by the original data gatherers, while a few were digitized from publications. Most of the pollen records originate from peatlands (48 %) and lake sediments (33 %). Most of the records (83 %) have >= 3 dates, allowing the establishment of reliable chronologies. The dataset can be used for various purposes, including pollen data mapping (example maps for Larix at selected time slices are shown) as well as quantitative climate and vegetation reconstructions. The datasets for pollen counts and pollen percentages are available at https://doi.org/10.1594/PANGAEA.898616 (Cao et al., 2019a), also including the site information, data source, original publication, dating data, and the plant functional type for each pollen taxa.
KW - Late Quaternary vegetation
KW - Holocene environmental history
KW - eastern continental Asia
KW - plant macrofossil data
KW - late pleistocene
KW - paleoenvironmental records
KW - Verkhoyansk mountains
KW - climate dynamics
KW - glacial maximum
KW - Northern Asia
Y1 - 2020
U6 - https://doi.org/10.5194/essd-12-119-2020
SN - 1866-3508
SN - 1866-3516
VL - 12
IS - 1
SP - 119
EP - 135
PB - Copernics Publications
CY - Katlenburg-Lindau
ER -
TY - JOUR
A1 - Steirou, Eva
A1 - Gerlitz, Lars
A1 - Sun, Xun
A1 - Apel, Heiko
A1 - Agarwal, Ankit
A1 - Totz, Sonja Juliana
A1 - Merz, Bruno
T1 - Towards seasonal forecasting of flood probabilities in Europe using climate and catchment information
JF - Scientific reports
N2 - We investigate whether the distribution of maximum seasonal streamflow is significantly affected by catchment or climate state of the season/month ahead. We fit the Generalized Extreme Value (GEV) distribution to extreme seasonal streamflow for around 600 stations across Europe by conditioning the GEV location and scale parameters on 14 indices, which represent the season-ahead climate or catchment state. The comparison of these climate-informed models with the classical GEV distribution, with time-constant parameters, suggests that there is a substantial potential for seasonal forecasting of flood probabilities. The potential varies between seasons and regions. Overall, the season-ahead catchment wetness shows the highest potential, although climate indices based on large-scale atmospheric circulation, sea surface temperature or sea ice concentration also show some skill for certain regions and seasons. Spatially coherent patterns and a substantial fraction of climate-informed models are promising signs towards early alerts to increase flood preparedness already a season ahead.
Y1 - 2022
U6 - https://doi.org/10.1038/s41598-022-16633-1
SN - 2045-2322
VL - 12
IS - 1
PB - Nature portfolio
CY - Berlin
ER -