TY - JOUR A1 - Bathke, Hannes A1 - Sudhaus, Henriette A1 - Holohan, E. P. A1 - Walter, T. R. A1 - Shirzaei, M. T1 - An active ring fault detected at Tendurek volcano by using InSAR JF - JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH N2 - Although ring faults are present at many ancient, deeply eroded volcanoes, they have been detected at only very few modern volcanic centers. At the so far little studied Tendurek volcano in eastern Turkey, we generated an ascending and a descending InSAR time series of its surface displacement field for the period from 2003 to 2010. We detected a large (similar to 105km(2)) region that underwent subsidence at the rate of similar to 1cm/yr during this period. Source modeling results show that the observed signal fits best to simulations of a near-horizontal contracting sill located at around 4.5km below the volcano summit. Intriguingly, the residual displacement velocity field contains a steep gradient that systematically follows a system of arcuate fractures visible on the volcano’s midflanks. RapidEye satellite optical images show that this fracture system has deflected Holocene lava flows, thus indicating its presence for at least several millennia. We interpret the arcuate fracture system as the surface expression of an inherited ring fault that has been slowly reactivated during the detected recent subsidence. These results show that volcano ring faults may not only slip rapidly during eruptive or intrusive phases, but also slowly during dormant phases. KW - Tendurek volcano KW - caldera subsidence KW - arcuate fracture system KW - fault reactivation Y1 - 2013 U6 - https://doi.org/10.1002/jgrb.50305 SN - 2169-9313 VL - 118 IS - 8 SP - 4488 EP - 4502 PB - AMER GEOPHYSICAL UNION CY - WASHINGTON ER - TY - JOUR A1 - Heslop, J. K. A1 - Anthony, K. M. Walter A1 - Grosse, Guido A1 - Liebner, Susanne A1 - Winkel, Matthias T1 - Century-scale time since permafrost thaw affects temperature sensitivity of net methane production in thermokarst-lake and talik sediments JF - The science of the total environment : an international journal for scientific research into the environment and its relationship with man N2 - Permafrost thaw subjects previously frozen soil organic carbon (SOC) to microbial degradation to the greenhouse gases carbon dioxide (CO2) and methane (CH4). Emission of these gases constitutes a positive feedback to climate warming. Among numerous uncertainties in estimating the strength of this permafrost carbon feedback (PCF), two are: (i) how mineralization of permafrost SOC thawed in saturated anaerobic conditions responds to changes in temperature and (ii) how microbial communities and temperature sensitivities change over time since thaw. To address these uncertainties, we utilized a thermokarst-lake sediment core as a natural chronosequence where SOC thawed and incubated in situ under saturated anaerobic conditions for up to 400 years following permafrost thaw. Initial microbial communities were characterized, and sediments were anaerobically incubated in the lab at four temperatures (0 °C, 3 °C, 10 °C, and 25 °C) bracketing those observed in the lake's talik. Net CH4 production in freshly-thawed sediments near the downward-expanding thaw boundary at the base of the talik were most sensitive to warming at the lower incubation temperatures (0 °C to 3 °C), while the overlying sediments which had been thawed for centuries had initial low abundant methanogenic communities (< 0.02%) and did not experience statistically significant increases in net CH4 production potentials until higher incubation temperatures (10 °C to 25 °C). We propose these observed differences in temperature sensitivities are due to differences in SOM quality and functional microbial community composition that evolve over time; however further research is necessary to better constrain the roles of these factors in determining temperature controls on anaerobic C mineralization. KW - Carbon KW - Lake sediments KW - Methane KW - Permafrost KW - Talik KW - Temperature sensitivity Y1 - 2019 U6 - https://doi.org/10.1016/j.scitotenv.2019.06.402 SN - 0048-9697 SN - 1879-1026 VL - 691 SP - 124 EP - 134 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Stech, Marlitt A1 - Merk, Helmut A1 - Schenk, Jörg A. A1 - Stöcklein, Walter F. M. A1 - Wüstenhagen, Doreen Anja A1 - Micheel, Burkhard A1 - Duschl, Claus A1 - Bier, Frank Fabian A1 - Kubick, Stefan T1 - Production of functional antibody fragments in a vesicle-based eukaryotic cell-free translation system JF - Journal of biotechnology N2 - Cell-free protein synthesis is of increasing interest for the rapid and high-throughput synthesis of many proteins, in particular also antibody fragments. In this study, we present a novel strategy for the production of single chain antibody fragments (scFv) in a eukaryotic in vitro translation system. This strategy comprises the cell-free expression, isolation and label-free interaction analysis of a model antibody fragment synthesized in two differently prepared insect cell lysates. These lysates contain translocationally active microsomal structures derived from the endoplasmic reticulum (ER), allowing for posttranslational modifications of cell-free synthesized proteins. Both types of these insect cell lysates enable the synthesis and translocation of scFv into ER-derived vesicles. However, only the one that has a specifically adapted redox potential yields functional active antibody fragments. We have developed a new methodology for the isolation of functional target proteins based on the translocation of cell-free produced scFv into microsomal structures and subsequent collection of protein-enriched vesicles. Antibody fragments that have been released from these vesicles are shown to be well suited for label-free binding studies. Altogether, these results show the potential of insect cell lysates for the production, purification and selection of antibody fragments in an easy-to-handle and time-saving manner. KW - Cell-free KW - In vitro translation KW - Single chain antibody (scFv) KW - Insect lysate KW - Surface plasmon resonance Y1 - 2012 U6 - https://doi.org/10.1016/j.jbiotec.2012.08.020 SN - 0168-1656 VL - 164 IS - 2 SP - 220 EP - 231 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Nassar, Yomna M. A1 - Hohmann, Nicolas A1 - Michelet, Robin A1 - Gottwalt, Katharina A1 - Meid, Andreas D. A1 - Burhenne, Jürgen A1 - Huisinga, Wilhelm A1 - Haefeli, Walter E. A1 - Mikus, Gerd A1 - Kloft, Charlotte T1 - Quantification of the Time Course of CYP3A Inhibition, Activation, and Induction Using a Population Pharmacokinetic Model of Microdosed Midazolam Continuous Infusion JF - Clinical Pharmacokinetics N2 - Background Cytochrome P450 (CYP) 3A contributes to the metabolism of many approved drugs. CYP3A perpetrator drugs can profoundly alter the exposure of CYP3A substrates. However, effects of such drug-drug interactions are usually reported as maximum effects rather than studied as time-dependent processes. Identification of the time course of CYP3A modulation can provide insight into when significant changes to CYP3A activity occurs, help better design drug-drug interaction studies, and manage drug-drug interactions in clinical practice. Objective We aimed to quantify the time course and extent of the in vivo modulation of different CYP3A perpetrator drugs on hepatic CYP3A activity and distinguish different modulatory mechanisms by their time of onset, using pharmacologically inactive intravenous microgram doses of the CYP3A-specific substrate midazolam, as a marker of CYP3A activity. Methods Twenty-four healthy individuals received an intravenous midazolam bolus followed by a continuous infusion for 10 or 36 h. Individuals were randomized into four arms: within each arm, two individuals served as a placebo control and, 2 h after start of the midazolam infusion, four individuals received the CYP3A perpetrator drug: voriconazole (inhibitor, orally or intravenously), rifampicin (inducer, orally), or efavirenz (activator, orally). After midazolam bolus administration, blood samples were taken every hour (rifampicin arm) or every 15 min (remaining study arms) until the end of midazolam infusion. A total of 1858 concentrations were equally divided between midazolam and its metabolite, 1'-hydroxymidazolam. A nonlinear mixed-effects population pharmacokinetic model of both compounds was developed using NONMEM (R). CYP3A activity modulation was quantified over time, as the relative change of midazolam clearance encountered by the perpetrator drug, compared to the corresponding clearance value in the placebo arm. Results Time course of CYP3A modulation and magnitude of maximum effect were identified for each perpetrator drug. While efavirenz CYP3A activation was relatively fast and short, reaching a maximum after approximately 2-3 h, the induction effect of rifampicin could only be observed after 22 h, with a maximum after approximately 28-30 h followed by a steep drop to almost baseline within 1-2 h. In contrast, the inhibitory impact of both oral and intravenous voriconazole was prolonged with a steady inhibition of CYP3A activity followed by a gradual increase in the inhibitory effect until the end of sampling at 8 h. Relative maximum clearance changes were +59.1%, +46.7%, -70.6%, and -61.1% for efavirenz, rifampicin, oral voriconazole, and intravenous voriconazole, respectively. Conclusions We could distinguish between different mechanisms of CYP3A modulation by the time of onset. Identification of the time at which clearance significantly changes, per perpetrator drug, can guide the design of an optimal sampling schedule for future drug-drug interaction studies. The impact of a short-term combination of different perpetrator drugs on the paradigm CYP3A substrate midazolam was characterized and can define combination intervals in which no relevant interaction is to be expected. Y1 - 2022 U6 - https://doi.org/10.1007/s40262-022-01175-6 SN - 0312-5963 SN - 1179-1926 VL - 61 IS - 11 SP - 1595 EP - 1607 PB - Springer CY - Northcote ER - TY - JOUR A1 - Schad, Daniel A1 - Garbusow, Maria A1 - Friedel, Eva A1 - Sommer, Christian A1 - Sebold, Miriam A1 - Hägele, Claudia A1 - Bernhardt, Nadine A1 - Nebe, Stephan A1 - Kuitunen-Paul, Sören A1 - Liu, Shuyan A1 - Eichmann, Uta A1 - Beck, Anne A1 - Wittchen, Hans-Ulrich A1 - Walter, Henrik A1 - Sterzer, Philipp A1 - Zimmermann, Ulrich S. A1 - Smolka, Michael N. A1 - Schlagenhauf, Florian A1 - Huys, Quentin J. M. A1 - Heinz, Andreas A1 - Rapp, Michael A. T1 - Neural correlates of instrumental responding in the context of alcohol-related cues index disorder severity and relapse risk JF - European archives of psychiatry and clinical neuroscience : official organ of the German Society for Biological Psychiatry N2 - The influence of Pavlovian conditioned stimuli on ongoing behavior may contribute to explaining how alcohol cues stimulate drug seeking and intake. Using a Pavlovian-instrumental transfer task, we investigated the effects of alcohol-related cues on approach behavior (i.e., instrumental response behavior) and its neural correlates, and related both to the relapse after detoxification in alcohol-dependent patients. Thirty-one recently detoxified alcohol-dependent patients and 24 healthy controls underwent instrumental training, where approach or non-approach towards initially neutral stimuli was reinforced by monetary incentives. Approach behavior was tested during extinction with either alcohol-related or neutral stimuli (as Pavlovian cues) presented in the background during functional magnetic resonance imaging (fMRI). Patients were subsequently followed up for 6 months. We observed that alcohol-related background stimuli inhibited the approach behavior in detoxified alcohol-dependent patients (t = -3.86, p < .001), but not in healthy controls (t = -0.92, p = .36). This behavioral inhibition was associated with neural activation in the nucleus accumbens (NAcc) (t((30)) = 2.06, p < .05). Interestingly, both the effects were only present in subsequent abstainers, but not relapsers and in those with mild but not severe dependence. Our data show that alcohol-related cues can acquire inhibitory behavioral features typical of aversive stimuli despite being accompanied by a stronger NAcc activation, suggesting salience attribution. The fact that these findings are restricted to abstinence and milder illness suggests that they may be potential resilience factors. KW - Alcohol dependence KW - Human neuroimaging KW - Nucleus accumbens KW - Pavlovian-instrumental transfer KW - Relapse Y1 - 2018 U6 - https://doi.org/10.1007/s00406-017-0860-4 SN - 0940-1334 SN - 1433-8491 VL - 269 IS - 3 SP - 295 EP - 308 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Friedel, Eva A1 - Sebold, Miriam A1 - Kuitunen-Paul, Sören A1 - Nebe, Stephan A1 - Veer, Ilya M. A1 - Zimmermann, Ulrich S. A1 - Schlagenhauf, Florian A1 - Smolka, Michael N. A1 - Rapp, Michael A. A1 - Walter, Henrik A1 - Heinz, Andreas T1 - How Accumulated Real Life Stress Experience and Cognitive Speed Interact on Decision-Making Processes JF - Frontiers in human neuroscienc N2 - Rationale: Advances in neurocomputational modeling suggest that valuation systems for goal-directed (deliberative) on one side, and habitual (automatic) decision-making on the other side may rely on distinct computational strategies for reinforcement learning, namely model-free vs. model-based learning. As a key theoretical difference, the model-based system strongly demands cognitive functions to plan actions prospectively based on an internal cognitive model of the environment, whereas valuation in the model-free system relies on rather simple learning rules from operant conditioning to retrospectively associate actions with their outcomes and is thus cognitively less demanding. Acute stress reactivity is known to impair model-based but not model-free choice behavior, with higher working memory capacity protecting the model-based system from acute stress. However, it is not clear which impact accumulated real life stress has on model-free and model-based decision systems and how this influence interacts with cognitive abilities. Methods: We used a sequential decision-making task distinguishing relative contributions of both learning strategies to choice behavior, the Social Readjustment Rating Scale questionnaire to assess accumulated real life stress, and the Digit Symbol Substitution Test to test cognitive speed in 95 healthy subjects. Results: Individuals reporting high stress exposure who had low cognitive speed showed reduced model-based but increased model-free behavioral control. In contrast, subjects exposed to accumulated real life stress with high cognitive speed displayed increased model-based performance but reduced model-free control. Conclusion: These findings suggest that accumulated real life stress exposure can enhance reliance on cognitive speed for model-based computations, which may ultimately protect the model-based system from the detrimental influences of accumulated real life stress. The combination of accumulated real life stress exposure and slower information processing capacities, however, might favor model-free strategies. Thus, the valence and preference of either system strongly depends on stressful experiences and individual cognitive capacities. KW - chronic stress KW - model-based learning KW - model-free learning KW - decision making KW - cognitive speed KW - real-life events Y1 - 2017 U6 - https://doi.org/10.3389/fnhum.2017.00302 SN - 1662-5161 VL - 11 SP - 1 EP - 9 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Flóvenz, Ólafur G. A1 - Wang, Rongjiang A1 - Hersir, Gylfi Páll A1 - Dahm, Torsten A1 - Hainzl, Sebastian A1 - Vassileva, Magdalena A1 - Drouin, Vincent A1 - Heimann, Sebastian A1 - Isken, Marius Paul A1 - Gudnason, Egill Á. A1 - Ágústsson, Kristján A1 - Ágústsdóttir, Thorbjörg A1 - Horálek, Josef A1 - Motagh, Mahdi A1 - Walter, Thomas R. A1 - Rivalta, Eleonora A1 - Jousset, Philippe A1 - Krawczyk, Charlotte M. A1 - Milkereit, Claus T1 - Cyclical geothermal unrest as a precursor to Iceland's 2021 Fagradalsfjall eruption JF - Nature geoscience N2 - Understanding and constraining the source of geodetic deformation in volcanic areas is an important component of hazard assessment. Here, we analyse deformation and seismicity for one year before the March 2021 Fagradalsfjall eruption in Iceland. We generate a high-resolution catalogue of 39,500 earthquakes using optical cable recordings and develop a poroelastic model to describe three pre-eruptional uplift and subsidence cycles at the Svartsengi geothermal field, 8 km west of the eruption site. We find the observed deformation is best explained by cyclic intrusions into a permeable aquifer by a fluid injected at 4 km depth below the geothermal field, with a total volume of 0.11 ± 0.05 km3 and a density of 850 ± 350 kg m–3. We therefore suggest that ingression of magmatic CO2 can explain the geodetic, gravity and seismic data, although some contribution of magma cannot be excluded. Y1 - 2022 U6 - https://doi.org/10.1038/s41561-022-00930-5 SN - 1752-0894 SN - 1752-0908 VL - 15 IS - 5 SP - 397 EP - 404 PB - Nature Research CY - Berlin ER - TY - JOUR A1 - Saritoprak, Zeki A1 - Vorpahl, Daniel A1 - Turan, Hakan A1 - Arslan, Hakki A1 - Zoref, Arye A1 - Tarabieh, Abdallah A1 - Yeshaya, Joachim A1 - Anzi, Menashe A1 - Merkur, Lianne A1 - Schmidt, Daniela A1 - Schuster, Dirk A1 - Langer, Armin A1 - Blum, Rahel A1 - Stürmann, Jakob A1 - Pohlmann, Julia A1 - Schulz, Michael Karl A1 - Arnold, Rafael D. A1 - Salzer, Dorothea M. A1 - Geißler-Grünberg, Anke A1 - Talabardon, Susanne A1 - Rasumny, Wiebke A1 - Stellmacher, Martha A1 - Denz, Rebekka A1 - Walter, Simon A1 - Grözinger, Elvira ED - Riemer, Nathanael ED - Sanci, Kadir ED - Schulz, Michael Karl T1 - PaRDeS : Zeitschrift der Vereinigung für Jüdische Studien = Muslimisch-Jüdischer Dialog T1 - PaRDeS : Journal of the Association of Jewish Studies = Muslim-Jewish Dialogue T2 - PaRDeS : Zeitschrift der Vereinigung für Jüdische Studien e.V. N2 - PaRDeS. Zeitschrift der Vereinigung für Jüdische Studien e.V., möchte die fruchtbare und facettenreiche Kultur des Judentums sowie seine Berührungspunkte zur Umwelt in den unterschiedlichen Bereichen dokumentieren. Daneben dient die Zeitschrift als Forum zur Positionierung der Fächer Jüdische Studien und Judaistik innerhalb des wissenschaftlichen Diskurses sowie zur Diskussion ihrer historischen und gesellschaftlichen Verantwortung. N2 - The journal aims at documenting the fruitful and multifarious culture of Judaism as well as its relations to its environment within diverse areas of research. In addition, the journal is meant to promote Jewish Studies within academic discourse and discuss its historic and social responsibility. T3 - PaRDeS : Zeitschrift der Vereinigung für Jüdische Studien e.V. - 22 Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-95416 SN - 978-3-86956-370-1 SN - 1614-6492 SN - 1862-7684 IS - 22 PB - Universitätsverlag Potsdam CY - Potsdam ER -