Vulkanische Seismizität des Vulkans Villarrica

This thesis analyzes the nature and origin of the low-frequent seismicity of Villarrica Volcano in Chile. Villarrica is an active volcano with an intermittent lava lake in its central vent. The typical volcanic activity consists of persistent degassing and usually mild Strombolian explosions and is accompanied by a notorious seismic tremor overlain by swarms of transient events in approximately 1-min intervals. Both types of signals display frequencies between 0.5 and 5 Hz. They are usually attributed to the volcanic activity with the transients being interpreted as the bursting of slugs at the surface of the lava lake (Strombolian explosions). This work examines the origin of the tremor signal and the nature of the transient events. The base for this work are 12 days of seismic data recorded by a dense local seismic network in early March 2012. The results are most likely applicable to today’s conditions since Villarrica is generally a stable system. The tremor source was located in the crater area using three different location methods. The occurrence of the transients in terms of magnitude and waiting time between two events is statistically similar to properties found for gaseous slugs flowing through a liquid-filled pipe and therefore supports the interpretation of these events as explosions. The waveforms could be classified into at least 67 families although the majority belonged to one of two families. The families likely originate in or close to the crater and share a similar source region

Bernard Delpal, Philippe Hanus, Olivier Vallade (dir.), Résistances juives. Solidarités, réseaux, parcours

Cet ouvrage collectif est né d’une rencontre organisée en 2016 à Moissac par l’association Moissac, ville de Justes oubliée, le réseau Mémorha Auvergne Rhône-Alpes et le Laboratoire de Recherche Historique Rhône-Alpes (LARHRA, CNRS). La rencontre a rassemblé acteurs institutionnels locaux (représentants associatifs et politiques des trois villes : Chambon, Dieulefit, Moissac), chercheurs (historiens pour la plupart) et témoins. Parmi ces acteurs, le réseau Memorha, dont le nom est une contrac..

Comparative interevent time statistics of degassing and seismic activity at Villarrica Volcano (Chile)

It is generally assumed that seismic activity at volcanoes is closely connected to degassing processes. Intuitively, one would therefore expect a good correlation between degassing rates and seismic amplitude. However, both examples and counterexamples of such a correlation exist. In this study on Villarrica volcano (Chile), we pursued a different approach to relate gas flux and volcanic seismicity using 3 months of SO$_2$ flux rate measurements and 12 days of seismic recordings from early 2012.<br /> We analyzed the statistical distributions of interevent times between transient seismic waveforms commonly associated with explosions and between peaks in the degassing time series.<br /> Both event types showed a periodic recurrence with a mode of 20-25 s and around 1 h for transients and degassing, respectively. The normalized interevent times were fitted by almost identical log-normal distributions. Given the actually very different time scales, this similarity potentially indicates a scale-invariant phenomenon. We could reproduce these empirical findings by modelling the occurrence of transients as a renewal process from which the degassing events were derived recursively with increasing probability since the previous degassing event. In this model, the seismic transients could be either produced by degassing processes within the conduit or by gas release at the lava lake surface while the longer intervals of the degassing events may be explained by accumulation of gas either in the magma column or in the juvenile gas plume.<br /> Additionally, we analyzed volcano-tectonic events, which behaved very differently from the transients. They showed the clustered occurrence of tectonic earthquakes

Does the circulating ketoconazole metabolite N-deacetyl ketoconazole contribute to the drug-drug interaction potential of the parent compound?

Ketoconazole is a strong inhibitor of cytochrome P450 3A4 (CYP3A4) and of P-glycoprotein (P-gp) and is often used as an index inhibitor especially for CYP3A4-mediated drug metabolism. A preliminary physiologically based pharmacokinetic (PBPK) model for drug-drug interactions indicated possible involvement of a metabolite to the perpetrator potential of ketoconazole. Still unknown for humans, in rodents, N-deacetyl ketoconazole (DAK) has been identified as the major ketoconazole metabolite. We therefore investigated in vitro, whether DAK also inhibits the human CYPs and drug transporters targeted by ketoconazole and quantified DAK in human plasma from healthy volunteers after receiving a single oral dose of 400 mg ketoconazole. Our data demonstrated that DAK also inhibits CYP3A4 (2.4-fold less potent than ketoconazole), CYP2D6 (13-fold more potent than ketoconazole), CYP2C19 (equally potent), P-gp (3.4-fold less potent than ketoconazole), breast cancer resistance protein (more potent than ketoconazole) and organic anion transporting polypeptide 1B1 and 1B3 (7.8-fold and 2.6-fold less potent than ketoconazole). After a single oral dose of 400 mg ketoconazole, maximum concentrations of DAK in human plasma were only 3.1 ‰ of the parent compound. However, assuming that DAK also highly accumulates in the human liver as demonstrated for rodents, inhibition of the proteins investigated could also be conceivable in vivo. In conclusion, DAK inhibits several CYPs and drug transporters, which might contribute to the perpetrator potential of ketoconazole

A Physiologically Based Pharmacokinetic Model of Ketoconazole and Its Metabolites as Drug–Drug Interaction Perpetrators

The antifungal ketoconazole, which is mainly used for dermal infections and treatment of Cushing’s syndrome, is prone to drug–food interactions (DFIs) and is well known for its strong drug– drug interaction (DDI) potential. Some of ketoconazole’s potent inhibitory activity can be attributed to its metabolites that predominantly accumulate in the liver. This work aimed to develop a wholebody physiologically based pharmacokinetic (PBPK) model of ketoconazole and its metabolites for fasted and fed states and to investigate the impact of ketoconazole’s metabolites on its DDI potential. The parent–metabolites model was developed with PK-Sim® and MoBi® using 53 plasma concentration-time profiles. With 7 out of 7 (7/7) DFI AUClast and DFI Cmax ratios within two-fold of observed ratios, the developed model demonstrated good predictive performance under fasted and fed conditions. DDI scenarios that included either the parent alone or with its metabolites were simulated and evaluated for the victim drugs alfentanil, alprazolam, midazolam, triazolam, and digoxin. DDI scenarios that included all metabolites as reversible inhibitors of CYP3A4 and P-gp performed best: 26/27 of DDI AUClast and 21/21 DDI Cmax ratios were within two-fold of observed ratios, while DDI models that simulated only ketoconazole as the perpetrator underperformed: 12/27 DDI AUClast and 18/21 DDI Cmax ratios were within the success limits

Facilitating stress prevention in micro and small-sized enterprises:Protocol for a mixed method study to evaluate the effectiveness and implementation process of targeted web-based interventions

BACKGROUND: Workplace-related stress is a major risk factor for mental and physical health problems and related sickness absence and productivity loss. Despite evidence regarding the effectiveness of different workplace-based interventions, the implementation of stress prevention interventions is rare, especially in micro and small-sized enterprises (MSE) with fewer than 50 employees. The joint research project “PragmatiKK”(+) aims to identify and address the specific barriers to the implementation of stress prevention interventions in MSE. This study protocol describes a mixed method study design to evaluate the effectiveness of adapted stress prevention interventions and the implementation process via an integrated web-based platform (“System P”) specifically targeted at MSE. METHODS: First, we develop a web-based intervention, which accounts for the specific working conditions in MSE and addresses stress prevention at a structural and behavioral level. Second, we use common methods of implementation research to perform an effect and process evaluation. We analyze the effectiveness of the web-based stress prevention interventions by comparing depressive symptoms at baseline and follow-up (after 6 months and 12 months). Indicators for a successful implementation process include acceptability, adoption, feasibility, reach, dose, and fidelity, which we will measure with quantitative web-based questionnaires and qualitative interviews. We will also analyze the accumulated usage data from the web-based platform. DISCUSSION: Collecting data on the implementation process and the effectiveness of a web-based intervention will help to identify and overcome common barriers to stress prevention in MSE. This can improve the mental health of employees in MSE, which constitute more than 90% of all enterprises in Germany. (+) Full Project Name: „PragmatiKK - Pragmatische Lösungen für die Implementation von Maßnahmen zur Stressprävention in Kleinst- und Kleinbetrieben “(= Pragmatic solutions for the implementation of stress prevention interventions in micro and small-sized enterprises). TRIAL REGISTRATION: German Register of Clinical Studies (DRKS): DRKS00026154, date of registration: 2021-09-16. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-022-12921-7

A single-source precursor route to anisotropic halogen-doped zinc oxide particles as a promising candidate for new transparent conducting oxide materials

Correccions a aquest document es poden consultar a a https://ddd.uab.cat/record/185756The license is subject to the Beilstein Journal of Nanotechnology terms and conditions: http://www.beilstein-journals.org/bjnanoNumerous applications in optoelectronics require electrically conducting materials with high optical transparency over the entire visible light range. A solid solution of indium oxide and substantial amounts of tin oxide for electronic doping (ITO) is currently the most prominent example for the class of so-called TCOs (transparent conducting oxides). Due to the limited, natural occurrence of indium and its steadily increasing price, it is highly desired to identify materials alternatives containing highly abundant chemical elements. The doping of other metal oxides (e.g., zinc oxide, ZnO) is a promising approach, but two problems can be identified. Phase separation might occur at the required high concentration of the doping element, and for successful electronic modification it is mandatory that the introduced heteroelement occupies a defined position in the lattice of the host material. In the case of ZnO, most attention has been attributed so far to n-doping via substitution of Zn²+ by other metals (e.g., Al³+). Here, we present first steps towards n-doped ZnO-based TCO materials via substitution in the anion lattice (O²− versus halogenides). A special approach is presented, using novel single-source precursors containing a potential excerpt of the target lattice 'HalZn·Zn₃O₃' preorganized on the molecular scale (Hal = I, Br, Cl). We report about the synthesis of the precursors, their transformation into halogene-containing ZnO materials, and finally structural, optical and electronic properties are investigated using a combination of techniques including FT-Raman, low- T photoluminescence, impedance and THz spectroscopies

Low-Frequency Seismicity at Villarrica Volcano: Source Location and Seismic Velocities

Villarrica Volcano (Chile) is one of the most active volcanoes in South America. Its low-frequency (≤5 Hz) seismicity consists of a continuous tremor, overlain by impulsive transient events of higher amplitude in 60-s intervals. This signal was recorded in March 2012 by an extensive local network, comprising 75 stations and including 6 subarrays. It allowed us to apply and compare three techniques to locate the origin of the seismicity: intersection of propagation directions determined by array analysis, mapping amplitudes, and modeling of amplitude decay. All methods yield almost identical, temporally stable, epicenters inside the summit crater, which confirms earlier attributions of the seismicity to volcanic activity inside the conduit. The discrete transients and the interevent tremor share the same source location. From the dominance of surface waves and the obvious scattering, we infer a source near the surface. For two arrays at the northern and western flank, a dispersion relation was derived, which allowed for the determination of S wave velocity-depth functions. At both locations, the velocity structure can be modeled by three layers with interfaces at 100 and 400m depths. The velocities (300 to 3,000 m/s) correspond to pyroclastic material at different states of consolidation. The modeling of the amplitude decay reveals a quality factor around 50

Grond reports for "Deep neural network based denoising of regional seismic waveforms and impact on analysis of North Korean nuclear tests"

<p>This are the Grond reports of the seismic moment tensor inversion done for the manuscript titled:</p><p>"Deep neural network based denoising of regional seismic waveforms and impact on analysis of North Korean nuclear tests"</p><p>You can view the summary figures of the inversions in the subfolders for each event manually if you wish.</p><p>However to view the reports interactively you need to have the pyrocko and grond softwares installed. See here for installation instruction for pyrocko: https://pyrocko.org/ and here for grond https://pyrocko.org/grond/docs/current/</p><p>After correct installation you can view the reports in any browser by executing the command "grond report --so" in the folder which contains the unpacked "report" folder.</p&gt