TY - JOUR A1 - Monhonval, Arthur A1 - Strauss, Jens A1 - Thomas, Maxime A1 - Hirst, Catherine A1 - Titeux, Hugues A1 - Louis, Justin A1 - Gilliot, Alexia A1 - D'Aische, Eleonore du Bois A1 - Pereira, Benoit A1 - Vandeuren, Aubry A1 - Grosse, Guido A1 - Schirrmeister, Lutz A1 - Jongejans, Loeka Laura A1 - Ulrich, Mathias A1 - Opfergelt, Sophie T1 - Thermokarst processes increase the supply of stabilizing surfaces and elements (Fe, Mn, Al, and Ca) for mineral-organic carbon interactions JF - Permafrost and periglacial processes N2 - The stabilizing properties of mineral-organic carbon (OC) interactions have been studied in many soil environments (temperate soils, podzol lateritic soils, and paddy soils). Recently, interest in their role in permafrost regions is increasing as permafrost was identified as a hotspot of change. In thawing ice-rich permafrost regions, such as the Yedoma domain, 327-466 Gt of frozen OC is buried in deep sediments. Interactions between minerals and OC are important because OC is located very near the mineral matrix. Mineral surfaces and elements could mitigate recent and future greenhouse gas emissions through physical and/or physicochemical protection of OC. The dynamic changes in redox and pH conditions associated with thermokarst lake formation and drainage trigger metal-oxide dissolution and precipitation, likely influencing OC stabilization and microbial mineralization. However, the influence of thermokarst processes on mineral-OC interactions remains poorly constrained. In this study, we aim to characterize Fe, Mn, Al, and Ca minerals and their potential protective role for OC. Total and selective extractions were used to assess the crystalline and amorphous oxides or complexed metal pools as well as the organic acids found within these pools. We analyzed four sediment cores from an ice-rich permafrost area in Central Yakutia, which were drilled (i) in undisturbed Yedoma uplands, (ii) beneath a recent lake formed within Yedoma deposits, (iii) in a drained thermokarst lake basin, and (iv) beneath a mature thermokarst lake from the early Holocene period. We find a decrease in the amount of reactive Fe, Mn, Al, and Ca in the deposits on lake formation (promoting reduction reactions), and this was largely balanced by an increase in the amount of reactive metals in the deposits on lake drainage (promoting oxidation reactions). We demonstrate an increase in the metal to C molar ratio on thermokarst process, which may indicate an increase in metal-C bindings and could provide a higher protective role against microbial mineralization of organic matter. Finally, we find that an increase in mineral-OC interactions corresponded to a decrease in CO2 and CH4 gas emissions on thermokarst process. Mineral-OC interactions could mitigate greenhouse gas production from permafrost thaw as soon as lake drainage occurs. KW - Arctic KW - organic carbon stabilization KW - permafrost KW - redox processes KW - thaw KW - Yedoma Y1 - 2022 U6 - https://doi.org/10.1002/ppp.2162 SN - 1045-6740 SN - 1099-1530 VL - 33 IS - 4 SP - 452 EP - 469 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Padash, Amin A1 - Sandev, Trifce A1 - Kantz, Holger A1 - Metzler, Ralf A1 - Chechkin, Aleksei T1 - Asymmetric Levy flights are more efficient in random search JF - Fractal and fractional N2 - We study the first-arrival (first-hitting) dynamics and efficiency of a one-dimensional random search model performing asymmetric Levy flights by leveraging the Fokker-Planck equation with a delta-sink and an asymmetric space-fractional derivative operator with stable index alpha and asymmetry (skewness) parameter beta. We find exact analytical results for the probability density of first-arrival times and the search efficiency, and we analyse their behaviour within the limits of short and long times. We find that when the starting point of the searcher is to the right of the target, random search by Brownian motion is more efficient than Levy flights with beta <= 0 (with a rightward bias) for short initial distances, while for beta>0 (with a leftward bias) Levy flights with alpha -> 1 are more efficient. When increasing the initial distance of the searcher to the target, Levy flight search (except for alpha=1 with beta=0) is more efficient than the Brownian search. Moreover, the asymmetry in jumps leads to essentially higher efficiency of the Levy search compared to symmetric Levy flights at both short and long distances, and the effect is more pronounced for stable indices alpha close to unity. KW - asymmetric Levy flights KW - first-arrival density KW - search efficiency Y1 - 2022 U6 - https://doi.org/10.3390/fractalfract6050260 SN - 2504-3110 VL - 6 IS - 5 PB - MDPI CY - Basel ER - TY - JOUR A1 - Katzenberger, Anja A1 - Levermann, Anders A1 - Schewe, Jacob A1 - Pongratz, Julia T1 - Intensification of very wet monsoon seasons in India under global warming JF - Geophysical research letters N2 - Rainfall-intense summer monsoon seasons on the Indian subcontinent that are exceeding long-term averages cause widespread floods and landslides. Here we show that the latest generation of coupled climate models robustly project an intensification of very rainfall-intense seasons (June-September). Under the shared socioeconomic pathway SSP5-8.5, very wet monsoon seasons as observed in only 5 years in the period 1965-2015 are projected to occur 8 times more often in 2050-2100 in the multi-model average. Under SSP2-4.5, these seasons become only a factor of 6 times more frequent, showing that even modest efforts to mitigate climate change can have a strong impact on the frequency of very strong rainfall seasons. Besides, we find that the increasing risk of extreme seasonal rainfall is accompanied by a shift from days with light rainfall to days with moderate or heavy rainfall. Additionally, the number of wet days is projected to increase. KW - Indian monsoon KW - climate modeling KW - extreme seasons KW - climate change KW - CMIP6 KW - India Y1 - 2022 U6 - https://doi.org/10.1029/2022GL098856 SN - 0094-8276 SN - 1944-8007 VL - 49 IS - 15 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Habel, Jan Christian A1 - Ulrich, Werner A1 - Eberle, Jonas A1 - Schmitt, Thomas T1 - Species community structures of Afrotropical butterflies differ depending on the monitoring method JF - Biodiversity and conservation N2 - Standardised biodiversity assessment is crucial to understand community structures and population dynamics of animals. There exist various methods to monitor biodiversity. Approaches differ depending on the target species group and the aim of study, and show advantages and disadvantages. The obtained data and results are influenced by local environmental conditions and seasonal variability. In a comparative approach, we studied butterfly diversity and community structure in the dryland savannah biome of south-eastern Kenya with two different methods, transect counts and bait trapping. We repeatedly collected data throughout the dry and rainy seasons, in both near natural and anthropogenically influenced landscapes. Significantly more species and individuals were recorded by transect counts than by bait trapping, though the larger and more mobile Nymphalid species (and in particular representatives of the genus Charaxes) were comparatively overrepresented in traps. The transect data revealed much more pronounced effects of land-use and seasonality than the trap data. These results show that the choice of data collection methods must depend on the general research question, habitat conditions and season. To study the relative variation of species diversity and abundance, the collection of a fraction of the total species diversity might be sufficient. However, if the focus is on a largely complete recording of species diversity, the use of various collection methods is essential. More specifically, our data clearly demonstrate that transect counts represent a reasonable method for assessing butterfly diversity for the African dryland savannah region, but fails to fully capture occurrences of all species. Bait trapping can be used only as a supplementary method for assessing some few highly mobile low-density species. KW - monitoring KW - transect count KW - bait trap KW - population dynamic KW - disturbance KW - seasonality Y1 - 2022 U6 - https://doi.org/10.1007/s10531-021-02332-2 SN - 0960-3115 SN - 1572-9710 VL - 31 IS - 1 SP - 245 EP - 259 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Lepre, Enrico A1 - Heske, Julian A1 - Nowakowski, Michal A1 - Scoppola, Ernesto A1 - Zizak, Ivo A1 - Heil, Tobias A1 - Kühne, Thomas D. A1 - Antonietti, Markus A1 - Lopez-Salas, Nieves A1 - Albero, Josep T1 - Ni-based electrocatalysts for unconventional CO2 reduction reaction to formic acid JF - Nano energy N2 - Electrochemical reduction stands as an alternative to revalorize CO2. Among the different alternatives, Ni single atoms supported on carbonaceous materials are an appealing catalytic solution due to the low cost and versatility of the support and the optimal usage of Ni and its predicted selectivity and efficiency (ca. 100% towards CO). Herein, we have used noble carbonaceous support derived from cytosine to load Ni subnanometric sites. The large heteroatom content of the support allows the stabilization of up to 11 wt% of Ni without the formation of nanoparticles through a simple impregnation plus calcination approach, where nickel promotes the stabilization of C3NOx frameworks and the oxidative support promotes a high oxidation state of nickel. EXAFS analysis points at nickel single atoms or subnanometric clusters coordinated by oxygen in the material surface. Unlike the wellknown N-coordinated Ni single sites selectivity towards CO2 reduction, O-coordinated-Ni single sites (ca. 7 wt% of Ni) reduced CO2 to CO, but subnanometric clusters (11 wt% of Ni) foster the unprecedented formation of HCOOH with 27% Faradaic efficiency at - 1.4 V. Larger Ni amounts ended up on the formation of NiO nanoparticles and almost 100% selectivity towards hydrogen evolution. KW - CO 2 reduction reaction KW - Noble carbon KW - Ni-O4 electrocatalysts KW - Formic acid Y1 - 2022 U6 - https://doi.org/10.1016/j.nanoen.2022.107191 SN - 2211-2855 SN - 2211-3282 VL - 97 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Allroggen, Niklas A1 - Heincke, Bjorn H. A1 - Koyan, Philipp A1 - Wheeler, Walter A1 - Ronning, Jan S. T1 - 3D ground-penetrating radar attribute classification BT - a case study from a paleokarst breccia pipe in the Billefjorden area on Spitsbergen, Svalbard JF - Geophysics N2 - Ground-penetrating radar (GPR) is a method that can provide detailed information about the near subsurface in sedimentary and carbonate environments. The classical interpretation of GPR data (e.g., based on manual feature selection) often is labor-intensive and limited by the experience of the intercally used for seismic interpretation, can provide faster, more repeatable, and less biased interpretations. We have recorded a 3D GPD data set collected across a paleokarst breccia pipe in the Billefjorden area on Spitsbergen, Svalbard. After performing advanced processing, we compare the results of a classical GPR interpretation to the results of an attribute-based classification. Our attribute classification incorporates a selection of dip and textural attributes as the input for a k-means clustering approach. Similar to the results of the classical interpretation, the resulting classes differentiate between undisturbed strata and breccias or fault zones. The classes also reveal details inside the breccia pipe that are not discerned in the classical fer that the intrapipe GPR facies result from subtle differences, such as breccia lithology, clast size, or pore-space filling. Y1 - 2022 U6 - https://doi.org/10.1190/GEO2021-0651.1 SN - 0016-8033 SN - 1942-2156 VL - 87 IS - 4 SP - WB19 EP - WB30 PB - Society of Exploration Geophysicists CY - Tulsa ER - TY - JOUR A1 - Illien, Luc A1 - Sens-Schönfelder, Christoph A1 - Andermann, Christoff A1 - Marc, Odin A1 - Cook, Kristen L. A1 - Adhikari, Lok Bijaya A1 - Hovius, Niels T1 - Seismic velocity recovery in the subsurface BT - transient damage and groundwater drainage following the 2015 Gorkha Earthquake, Nepal JF - Journal of geophysical research : Solid earth N2 - Shallow earthquakes frequently disturb the hydrological and mechanical state of the subsurface, with consequences for hazard and water management. Transient post-seismic hydrological behavior has been widely reported, suggesting that the recovery of material properties (relaxation) following ground shaking may impact groundwater fluctuations. However, the monitoring of seismic velocity variations associated with earthquake damage and hydrological variations are often done assuming that both effects are independent. In a field site prone to highly variable hydrological conditions, we disentangle the different forcing of the relative seismic velocity variations delta v retrieved from a small dense seismic array in Nepal in the aftermath of the 2015 M-w 7.8 Gorkha earthquake. We successfully model transient damage effects by introducing a universal relaxation function that contains a unique maximum relaxation timescale for the main shock and the aftershocks, independent of the ground shaking levels. Next, we remove the modeled velocity from the raw data and test whether the corresponding residuals agree with a background hydrological behavior we inferred from a previously calibrated groundwater model. The fitting of the delta v data with this model is improved when we introduce transient hydrological properties in the phase immediately following the main shock. This transient behavior, interpreted as an enhanced permeability in the shallow subsurface, lasts for similar to 6 months and is shorter than the damage relaxation (similar to 1 yr). Thus, we demonstrate the capability of seismic interferometry to deconvolve transient hydrological properties after earthquakes from non-linear mechanical recovery. KW - earthquake damage KW - earthquake hydrology KW - relaxation KW - Gorkha earthquake KW - seismic monitoring KW - ambient noise Y1 - 2022 U6 - https://doi.org/10.1029/2021JB023402 SN - 2169-9313 SN - 2169-9356 VL - 127 IS - 2 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Rodriguez, Victoria A1 - Moskwa, Lisa-Marie A1 - Oses, Romulo A1 - Kühn, Peter A1 - Riveras-Muñoz, Nicolás A1 - Seguel, Oscar A1 - Scholten, Thomas A1 - Wagner, Dirk T1 - Impact of climate and slope aspects on the composition of soil bacterial communities involved in pedogenetic processes along the chilean coastal cordillera JF - Microorganisms N2 - Soil bacteria play a fundamental role in pedogenesis. However, knowledge about both the impact of climate and slope aspects on microbial communities and the consequences of these items in pedogenesis is lacking. Therefore, soil-bacterial communities from four sites and two different aspects along the climate gradient of the Chilean Coastal Cordillera were investigated. Using a combination of microbiological and physicochemical methods, soils that developed in arid, semi-arid, mediterranean, and humid climates were analyzed. Proteobacteria, Acidobacteria, Chloroflexi, Verrucomicrobia, and Planctomycetes were found to increase in abundance from arid to humid climates, while Actinobacteria and Gemmatimonadetes decreased along the transect. Bacterial-community structure varied with climate and aspect and was influenced by pH, bulk density, plant-available phosphorus, clay, and total organic-matter content. Higher bacterial specialization was found in arid and humid climates and on the south-facing slope and was likely promoted by stable microclimatic conditions. The presence of specialists was associated with ecosystem-functional traits, which shifted from pioneers that accumulated organic matter in arid climates to organic decomposers in humid climates. These findings provide new perspectives on how climate and slope aspects influence the composition and functional capabilities of bacteria, with most of these capabilities being involved in pedogenetic processes. KW - bacterial-community structure KW - bacterial diversity KW - climate gradient KW - slope aspect KW - Chilean Coastal Cordillera KW - soil formation Y1 - 2022 U6 - https://doi.org/10.3390/microorganisms10050847 SN - 2076-2607 VL - 10 IS - 5 PB - MDPI CY - Basel ER - TY - JOUR A1 - Seidel-Jacobs, Esther A1 - Kohl, Fiona A1 - Tamayo, Miguel A1 - Rosenbauer, Joachim A1 - Schulze, Matthias Bernd A1 - Kuss, Oliver A1 - Rathmann, Wolfgang T1 - Impact of applying a diabetes risk score in primary care on change in physical activity BT - a pragmatic cluster randomised trial JF - Acta diabetologica N2 - Aim There is little evidence of the impact of diabetes risk scores on individual diabetes risk factors, motivation for behaviour changes and mental health. The aim of this study was to investigate the effect of applying a noninvasive diabetes risk score in primary care as component of routine health checks on physical activity and secondary outcomes. Methods Cluster randomised trial, in which primary care physicians (PCPs), randomised (1:1) by minimisation, enrolled participants with statutory health insurance without known diabetes, >= 35 years of age with a body mass index >= 27.0 kg/m(2). The German Diabetes Risk Score was applied as add-on to the standard routine health check, conducted in the controls. Primary outcome was the difference in participants' physical activity (International Physical Activity Questionnaire) after 12 months. Secondary outcomes included body mass index, perceived health, anxiety, depression, and motivation for lifestyle change. Analysis was by intention-to-treat principle using mixed models. Results 36 PCPs were randomised; remaining 30 PCPs (intervention: n = 16; control: n = 14) recruited 315 participants (intervention: n = 153; controls: n = 162). A slight increase in physical activity was observed in the intervention group with an adjusted mean change of 388 (95% confidence interval: - 235; 1011) metabolic equivalents minutes per week. There were no relevant changes in secondary outcomes. Conclusions The application of a noninvasive diabetes risk score alone is not effective in promoting physical activity in primary care. Clinical Trial Registration: ClinicalTrials.gov (NCT03234322, registration date: July 31, 2017). KW - Risk score KW - Risk prediction model KW - Type 2 diabetes KW - Prevention KW - Physical activity KW - Primary care Y1 - 2022 U6 - https://doi.org/10.1007/s00592-022-01895-y SN - 0940-5429 SN - 1432-5233 VL - 59 IS - 8 SP - 1031 EP - 1040 PB - Springer CY - Mailand ER - TY - JOUR A1 - Gerlach, Marius A1 - Preitschopf, Tobias A1 - Karaev, Emil A1 - Quitian-Lara, Heidy Mayerly A1 - Mayer, Dennis A1 - Bozek, John A1 - Fischer, Ingo A1 - Fink, Reinhold F. T1 - Auger electron spectroscopy of fulminic acid, HCNO BT - an experimental and theoretical study JF - Physical chemistry, chemical physics : a journal of European Chemical Societies N2 - HCNO is a molecule of considerable astrochemical interest as a precursor to prebiotic molecules. It is synthesized by preparative pyrolysis and is unstable at room temperature. Here, we investigate its spectroscopy in the soft X-ray regime at the C 1s, N 1s and O 1s edges. All 1s ionization energies are reported and X-ray absorption spectra reveal the transitions from the 1s to the pi* state. Resonant and normal Auger electron spectra for the decay of the core hole states are recorded in a hemispherical analyzer. An assignment of the experimental spectra is provided with the aid of theoretical counterparts. The latter are using a valence configuration interaction representation of the intermediate and final state energies and wavefunctions, the one-center approximation for transition rates and band shapes according to the moment theory. The computed spectra are in very good agreement with the experimental data and most of the relevant bands are assigned. Additionally, we present a simple approach to estimate relative Auger transition rates on the basis of a minimal basis representation of the molecular orbitals. We demonstrate that this provides a qualitatively good and reliable estimate for several signals in the normal and resonant Auger electron spectra which have significantly different intensities in the decay of the three core holes. Y1 - 2022 U6 - https://doi.org/10.1039/d2cp02104h SN - 1463-9076 SN - 1463-9084 VL - 24 IS - 25 SP - 15217 EP - 15229 PB - Royal Society of Chemistry CY - Cambridge ER -