Triggering Process Research Articles

Strengthening local economy – an example of higher education institutions’ engagement in “co-creation for sustainability”

Major societal challenges like energy efficiency, climate change and resource scarcity trigger and influence continuous change processes worldwide, nationwide, but also on all regional levels. They force regions to think about (a more) sustainable development. As the transformation processes necessary for sustainable development are complex there is a need for actors willing to engage and support sustainability transitions. Higher education institutions (HEIs) are often expected to be one of these supporters on the regional level. The central aim of this paper is to show by the use of an example, that HEIs are able to provide impulses for sustainable transformation. Following Pflitsch and Radinger-Peer (2018:918) HEIs can play different roles in regional sustainable transition; the authors use two dimensions to distinguish these roles – depth and autonomy:
 - As to depth HEIs’ roles can be “comprehensive, involving diverse actors and approaching sustainability with a holistic perspective” or “more fragmented and passive, but also more focused on specific topics”.
 - As to autonomy the roles can be “autonomous, the university defining its own focus and priorities through interacting with a broad range of regional actors” or “more directed, the university working on topics that are relevant from the perspective of the regional or federal-state government”.
 Using this rough classification the HEI in our example focuses on a “specific topic” and it is interacting with other regional respectively local actors on a topic that is not only relevant from the perspective of most German cities and their citizens but also from the national and federal government’s perspective. The paper starts with a short systemisation of transfer channels and missions of HEIs. It starts with a description of transfer channels used by the two traditional missions of HEIs – education and research. Afterwards the concept of “third mission” is introduced and distinguished from a possible fourth mission of HEIs – the concept of “co-creation for sustainability”. Afterwards it deals with important concepts and approaches which are characteristic elements of “co-creation for sustainability” – transformative research, participatory action research (PAR), urban living labs and student service learning. The “specific topic” that serves as an example is introduced after that: it is about the problem of local economy in urban neighbourhoods. Local economy will be defined, its problems resulting from the functional change of urban neighbourhoods are sketched and the arising necessity of strengthening local economies will be discussed. We show the methodological concept that is used to develop strategies and specific measures for strengthening local economy. The paper shows that the elements of this concept are typical approaches of transformative sciences. Afterwards concrete examples stemming from an urban neighbourhood which is part of the city of Viersen (Northrhine-Westphalia, Germany) is used to show, how the approach works in practise. The paper ends trying to explain, why projects like this give an example of HEIs’ impulses for sustainable development in their regional surrounding. Furthermore, the usefulness, but also the shortcomings and further research necessities of the approach will be discussed.

Dynamical descriptors of physical vulnerability to sea-level rise in sheltered coastal systems: A methodological framework

Many studies about the susceptibility of coastal systems to flood hazard have been carried out using similar methodological approaches, based on the spatial integration of structural and dynamical variables. However, although the general framework fits well to most exposed coastal sectors, few examples can be found in the literature regarding the proposal of dynamical descriptors (variables of process) particularly relevant to the analysis of the physical vulnerability of sheltered coastal systems, such as lagoons. The aim of this study was to propose a methodology to assess the physical vulnerability to sea-level rise due to climate change which was tested in the Conceição Lagoon, located in Santa Catarina (Brazil), based on dynamic descriptors obtained from numerical modeling. After implementing a numerical model calibrated to satisfactorily reproduce the hydrodynamic characteristics of the studied system, we simulated different sea-level rise scenarios proposed by the Intergovernmental Panel on Climate Change (IPCC), using optimistic and pessimistic scenarios for the years 2050 and 2100. Results were classified following the often-adopted scheme of very low to very high vulnerability. The maximum variations in the lagoon level calculated by the model showed the importance of winds and tides (both astronomical and meteorological) as the main triggering processes of level oscillation. The final physical vulnerability spatial distribution, obtained by the integration of maximum lagoon level variations associated with future projections, allowed the recognition of the sectors within the lagoon system which are more prone to suffering impacts. Most of the system was considered to have an intermediate vulnerability to sea-level rise. However, sectors with high vulnerability were also identified, mostly located at the northern and southern shores of the lagoon (due to wind influence), as well as along its inlet margins (due to ocean dynamics). The proposed framework based on the variations of the water level can be widely adopted as a descriptor that synthesizes the main dynamic processes responsible for the physical vulnerability of sheltered systems, fitting to lagoons and bays with different physiographic characteristics. The determination of the spatial distribution of areas with different degrees of susceptibility can be a valuable tool for coastal planning and management actions to be performed in sheltered systems, which has been overlooked comparing to those applied in open coasts.

Spatial and temporal influence of rainfall on crustal pore pressure based on seismic velocity monitoring

Crustal pore pressure, which controls the activities of earthquakes and volcanoes, varies in response to rainfall. The status of pore pressure can be inferred from observed changes in seismic velocity. In this study, we investigate the response of crustal pore pressure to rainfall in southwestern Japan based on time series of seismic velocity derived from ambient noise seismic interferometry. To consider the heterogeneity of the area, rainfall and seismic velocity obtained at each location were directly compared. We used a band-pass filter to distinguish the rainfall variability from sea level and atmospheric pressure, and then calculated the cross-correlation between rainfall and variations in S-wave velocity (Vs). A mostly negative correlation between rainfall and Vs changes indicates groundwater recharge by rainfall, which increases pore pressure. The correlations differ between locations, where most of the observation stations with clear negative cross-correlations were located in areas of granite. On the other hand, we could not observe clear correlations in steep mountain areas, possibly because water flows through river without percolation. This finding suggests that geographical features contribute to the imprint of rainfall on deep formation pore pressure. We further modelled pore pressure change due to rainfall based on diffusion mechanism. A strong negative correlation between pore pressure estimated from rainfall and Vs indicates that the Vs variations are triggered by pore pressure diffusion in the deep formation. Our modelling results show a spatial variation of diffusion parameter which controls the pore pressure in deep formation. By linking the variations in seismic velocity and crustal pore pressure spatially, this study shows that seismic monitoring may be useful in evaluating earthquake triggering processes or volcanic activity.

Sequential Fault Reactivation and Secondary Triggering in the March 2019 Red Deer Induced Earthquake Swarm

AbstractUsing data from nodal geophones and broadband seismometers, this study investigates the seismicity near Red Deer, Alberta, a region with increasing cases of hydraulic fracturing (HF)‐induced earthquakes. A cluster of 417 events was detected, and their spatial distribution and focal mechanisms reveal a NE trending rupture area with two strike‐slip fault planes. Reactivation of preexisting faults by pore pressure diffusion is likely responsible for the occurrence of the earthquake sequence following the ML 4.18 mainshock. The temporal sequence of reactivated fault orientations suggests apparent changes in the local stress field following the mainshock, which is also responsible for a remotely triggered cluster observed 1 month after the mainshock. This secondary triggering process enhances our understanding of the trailing effect of HF‐induced seismicity.

A Shallow-Water Model for Convective Self-Aggregation

AbstractRandomly distributed convective storms can self-aggregate in the absence of large-scale forcings. Here we present a 1D shallow-water model to study the convective self-aggregation. This model simulates the dynamics of the planetary boundary layer and represents convection as a triggered process. Once triggered, convection lasts for finite time and occupies finite length. We show that the model can successfully simulate self-aggregation, and that the results are robust to a wide range of parameter values. In the simulations, convection excites gravity waves. The gravity waves then form a standing wave pattern, separating the domain into convectively active and inactive regions. We analyze the available potential energy (APE) budget and show that convection generates APE, providing energy for self-aggregation. By performing dimensional analysis, we develop a scaling theory for the size of convective aggregation, which is set by the gravity wave speed, damping time scale, and number density of convective storms. This paper provides a simple modeling framework to further study convective self-aggregation.

Explicitation and cognitive load in simultaneous interpreting

AbstractThis article investigates the correlation between explicitation and increased cognitive load in simultaneous interpreting by trainee interpreters. It has been hypothesised, on the one hand, that certain explicitating shifts in simultaneous interpreting may be caused by increased cognitive load and they may be performed in an attempt to mask processing problems; and, on the other, that performing explicitating shifts may lead to increased cognitive load and trigger processing problems. The study triangulates product analysis (manual comparison of source and target texts) with process analysis (retrospective protocols of the participants). In the product the correlation between the occurrence of explicitating shifts and increased cognitive load is sought by identifying problem indicators in the form of three types of disfluency: hesitation markers, false starts and anomalous pauses exceeding two seconds (performance measure). Retrospective protocols are analysed in search of reports of explicitating shifts and/or increased cognitive load experienced and/or the cognitive effort expended (subjective measure). The product analysis shows the correlation between explicitating shifts and cognitive load at the level of 31%. The Spearman’s rank-order correlation coefficientr = 0.48 indicates that there is a positive association between these two variables. This finding is further confirmed by 122 retrospective comments of the subjects in the study.

Empirical formula for the quality factors of crack resonances and its application to the estimation of source properties of long-period seismic events at active volcanoes

SUMMARYLong-period (LP) seismic events at active volcanoes are thought to be generated by oscillations of fluid-filled resonators. The resonator geometry and fluid properties of LP sources have been estimated by comparing observed frequencies and quality factors (Q) with those calculated by numerical simulations with a crack model. A method to estimate all the parameters of crack geometry and fluid properties using an analytical formula for crack resonance frequencies has recently been proposed, but this method requires long computational times to compare observed and simulated Q values, especially for LP events with large Q. To resolve this problem, we used numerical simulations to systematically investigate the empirical relation between Q and crack model parameters. We found that Q can be calculated with an empirical formula expressed by the crack width-to-length ratio and the ratio of P-wave velocity in the solid medium to sound speed in the fluid. We applied this formula to LP events at Kusatsu–Shirane volcano, Japan, between 1992 August and 1993 January and at Galeras volcano, Colombia, in 1993 January. Assuming misty gas as the fluid in the crack at Kusatsu–Shirane and dusty gas as the fluid at Galeras, the empirical formula provided more detailed estimates of the parameters than those obtained previously using the Q values estimated in numerical simulations. We then applied the empirical formula to LP events with large Q values observed at Galeras between 2006 December and 2007 January. When we assumed dusty gas as the fluid in the crack, we found decreasing trends in both crack volume and the gas-weight fraction of water vapour in the crack. We also found that the dust volume was proportionally related to the product of crack aperture and crack length or width. These trends and relations were similar to those in 1993 January, suggesting that the LP events at Galeras between 2006 and 2007 were triggered by the explosive fragmentation of intruded magma and the production of a dusty gas, as was previously inferred for the LP events in 1993 January. Welding of ash in the dusty gas and dense magma remaining in the conduit after fragmentation led to a decrease in the source crack size prior to the next LP event. These results demonstrate that our empirical formula for Q can be used to estimate the source properties of LP events with large Q values without requiring long computational times. Use of the formula may thus contribute to improved monitoring of fluid states and understanding of LP triggering processes beneath many volcanoes.

An electromagnetic view of relay time in propagation of neural signals* *Project supported by the National Key Research and Development Program of China (Grant Nos. 2017YFA0701302 and 2016YFA0200802) and the Fundamental Research Funds of Shandong University, China (Grant No. 2018GN030).

We review the experimental and computational data about the propagation of neural signals in myelinated axons in mice, cats, rabbits, and frogs published in the past five decades. In contrast to the natural assumption that neural signals occur one by one in time and in space, we figure out that neural signals are highly overlapped in time between neighboring nodes. This phenomenon was occasionally illustrated in some early reports, but seemed to have been overlooked for some time. The shift in time between two successive neural signals from neighboring nodes, defined as relay time τ, was calculated to be only 16.3 μs–87.0 μs, i.e., 0.8 %–4.4 % of the average duration of an action potential peak (roughly 2 ms). We present a clearer picture of the exact physical process about how the information transmits along a myelinated axon, rather than a whole action potential peak, what is transmitted is only a rising electric field caused by transmembrane ion flows. Here in the paper, τ represents the waiting time until the neighboring node senses an attenuated electric field reaching the threshold to trigger the open state. The mechanisms addressed in this work have the potential to be universal, and may hold clues to revealing the exact triggering processes of voltage-gated ion channels and various brain functions.

Local topography effects on the surface temperatures on Mars – Application to the case of Recurring Slope Lineae (RSL)

Recurring Slope Lineae (RSL) are dark linear recurrent features which incrementally lengthen and fade each year on Martian slopes. Their activity during warmest seasons rises the question of modern martian water related process. To investigate this question, this study focuses on the thermal context of slopes hosting RSL. The paper presents a numerical study of surface and subsurface temperatures at high spatial resolution (1 m/pix) of three well-described RSL sites: Palikir Crater, Coprates Chasma and Rauna Crater. We then compare our local thermal simulations to quantitative measurements of the length and timing of RSL lengthening and fading in these three sites. We underline that RSL sites surface temperatures are poorly correlated with RSL morphology's changes. Indeed, lineae lengthening occurs while surface temperature are under the melting point of pure water (273 K) for at least two sites: Coprates Chasma and Rauna Crater, for two different sets of surface physical properties. We also highlight the significant differences in temperature range while lengthening occurs for all the sites, from ~220 K in Coprates Chasma site to a maximum of ~300 K in Palikir Crater. RSL are sometimes associated with signals in topography, involving significant heating variations of the surface, which can yield to the formation of local winds. Facing the thermal inconsistency between wet triggering processes and RSL reported activity, we suggest that RSL are more probably dry processes.

Aspergillus-Derived Galactosaminogalactan Triggers Complement Activation on Human Platelets.

Invasive fungal infections caused by Aspergillus (A.) and Mucorales species still represent life-threatening diseases in immunocompromised individuals, and deeper knowledge about fungal interactions with elements of innate immunity, such as complement and platelets, appears essential for optimized therapy. Previous studies showed that galactosaminogalactan secreted by A. fumigatus and A. flavus is deposited on platelets, thereby inducing their activation. Since the altered platelet surface is a putative trigger for complement activation, we aimed to study the interplay of platelets with complement in the presence of fungal GAG. Culture supernatants (SN) of A. fumigatus and A. flavus both induced not only GAG deposition but also subsequent deposition of complement C3 fragments on the platelet surface. The SN of a Δuge3 mutant of A. fumigatus, which is unable to synthesize GAG, did not induce complement deposition on platelets, nor did the SN of other Aspergillus species and all tested Mucorales. Detailed analysis revealed that GAG deposition itself triggered the complement cascade rather than the GAG-induced phosphatidylserine exposure. The lectin pathway of complement could be shown to be crucially involved in this process. GAG-induced complement activation on the platelet surface was revealed to trigger processes that might contribute to the pathogenesis of invasive aspergillosis by A. fumigatus or A. flavus. Both pro-inflammatory anaphylatoxins C3a and C5a arose when platelets were incubated with SN of these fungal species; these processes might favor excessive inflammation after fungal infection. Furthermore, platelets were stimulated to shed microparticles, which are also known to harbor pro-inflammatory and pro-coagulant properties. Not only did early processes of the complement cascade proceed on platelets, but also the formation of the terminal complement C5b-9 complex was detected on platelets after incubation with fungal SN. Subsequently, reduced viability of the platelets could be shown, which might contribute to the lowered platelet numbers found in infected patients. In summary, fungal GAG initiates an interplay between complement and platelets that can be supposed to contribute to excessive inflammation, thrombocytopenia, and thrombosis, which are important hallmarks of fatal invasive mycoses.

Transient analysis of the active surge protection gap trigger process with lightning voltage impulse injection

An active gas surge protection gap (SPG) and its energy coupling trigger circuit were designed in this study. In the lightning voltage impulse test, the active SPG had better protection characteristics than the passive SPG. To investigate the influence of the trigger circuit on the protection characteristics, the transient voltage and current characteristics of each electrical component in the active coupling trigger circuit were discussed. The equivalent model of the active trigger circuit was established, and the correlation between the active SPG protection characteristics and the active trigger circuit parameters was derived. According to the relationship, the theoretical breakdown characteristics of the active SPGs can be obtained by MATLAB. The deviation between simulated results and experimental data was no more than 11%. Based on the simulation, the design principles of the active energy coupling triggering circuit were proposed, laying the foundation for the theoretical research and engineering application of active SPGs.

Impact of reservoir heterogeneity on fluid injection-induced fault slip: insights from numerical simulation

In order to meet the growing energy demand worldwide, the technology of hydraulic fracturing for shale gas extraction has been rapidly developed and applied in recent years. However, man-made fluid injection has also caused several problems of high societal concern such as induced earthquakes. The focus of this paper is on the process of induced fault activation in shale reservoirs caused by hydraulic stimulation activities. We constructed a two-dimensional numerical model representing the horizontal cross-section of a faulted reservoir and simulated important coupled hydro-mechanical processes during fluid injection. We parameterized our model with the site investigation data of an actual shale gas project including in-situ stress, rock properties and injection protocol, etc. We represented the natural fault zone as a geological composite involving a fault core and a damage zone consisting of a set of subsidiary fractures parallel to the fault strike. We coupled the solid deformation and fault displacement with Darcy-type fluid flow based on poroelasticity principles and hydro-mechanical constitutive relationships. The heterogeneous nature of the permeability of the shale formation is mimicked by a random field model governed by a log-normal probability density function and directional correlation lengths, such that we can explore the impact of reservoir heterogeneity on the fault slip behaviour. In addition, we also studied the effects of fault length, dip angle and injection point-to-fault distance on the fault slip. Specifically, we analysed the link between fault slip and fluid flow field, permitting the capture of fluid movement in the heterogeneous faulted reservoir, the temporal and spatial evolution of preferential flow channels and their consequences on induced fault slip. The results of this research have important implications for understanding the triggering processes and mechanisms of fault slip during shale gas exploitation as well as many other injection-related engineering activities.

Readout system of the ALICE Fast Interaction Trigger

The Fast Interaction Trigger (FIT) detector will be essential for the operation of the ALICE experiment at CERN during Run 3 and 4 of the LHC . FIT will serve as an interaction trigger, luminometer, the first indicator of the vertex position, and the forward multiplicity counter. It will also provide the precise collision time for the TOF-based particle identification, yield the centrality and interaction plane for flow measurements, and measure cross sections of diffractive processes. In order to cope with an increased interaction rate of up to 1 MHz in proton-proton (pp) collisions and up to 50 kHz in Pb-Pb collisions, a new readout system for the ALICE FIT detector has been designed and implemented. FIT readout system is compatible both with the triggered and continuous (triggers-less) ALICE readout modes. The GBT-FPGA based FIT readout and trigger systems allow to stream data up to 5.5 MHz event rate with 3.2 Gbps data rate. The trigger processing time is only 225 ns. With the additional 200 ns delay along the connecting signal cables, the total latency of the FIT trigger is 425 ns.

P50, N100, and P200 Auditory Sensory Gating Deficits in Schizophrenia Patients.

BackgroundSensory gating describes neurological processes of filtering out redundant or unnecessary stimuli during information processing, and sensory gating deficits may contribute to the symptoms of schizophrenia. Among the three components of auditory event-related potentials reflecting sensory gating, P50 implies pre-attentional filtering of sensory information and N100/P200 reflects attention triggering and allocation processes. Although diminished P50 gating has been extensively documented in patients with schizophrenia, previous studies on N100 were inconclusive, and P200 has been rarely examined. This study aimed to investigate whether patients with schizophrenia have P50, N100, and P200 gating deficits compared with control subjects.MethodsControl subjects and clinically stable schizophrenia patients were recruited. The mid-latency auditory evoked responses, comprising P50, N100, and P200, were measured using the auditory-paired click paradigm without manipulation of attention. Sensory gating parameters included S1 amplitude, S2 amplitude, amplitude difference (S1-S2), and gating ratio (S2/S1). We also evaluated schizophrenia patients with PANSS to be correlated with sensory gating indices.ResultsOne hundred four patients and 102 control subjects were examined. Compared to the control group, schizophrenia patients had significant sensory gating deficits in P50, N100, and P200, reflected by larger gating ratios and smaller amplitude differences. Further analysis revealed that the S2 amplitude of P50 was larger, while the S1 amplitude of N100/P200 was smaller, in schizophrenia patients than in the controls. We found no correlations between sensory gating indices and schizophrenia positive or negative symptom clusters. However, we found a negative correlation between the P200 S2 amplitude and Bell’s emotional discomfort factor/Wallwork’s depressed factor.ConclusionTill date, this study has the largest sample size to analyze P50, N100, and P200 collectively by adopting the passive auditory paired-click paradigm without distractors. With covariates controlled for possible confounds, such as age, education, smoking amount and retained pairs, we found that schizophrenia patients had significant sensory gating deficits in P50-N100-P200. The schizophrenia patients had demonstrated a unique pattern of sensory gating deficits, including repetition suppression deficits in P50 and stimulus registration deficits in N100/200. These results suggest that sensory gating is a pervasive cognitive abnormality in schizophrenia patients that is not limited to the pre-attentive phase of information processing. Since P200 exhibited a large effect size and did not require additional time during recruitment, future studies of P50-N100-P200 collectively are highly recommended.

Variational phase-field continuum model uncovers adhesive wear mechanisms in asperity junctions

Wear is well known for causing material loss in a sliding interface. Available macroscopic approaches are bound to empirical fitting parameters, which range several orders of magnitude. Major advances in tribology have recently been achieved via Molecular Dynamics, although its use is strongly limited by computational cost. Here, we propose a study of the physical processes that lead to wear at the scale of the surface roughness, where adhesive junctions are formed between the asperities on the surface of the materials. Using a brittle formulation of the variational phase-field approach to fracture, we demonstrate that the failure mechanisms of an adhesive junction can be linked to its geometry. By imposing specific couplings between the damage and the elastic energy, we further investigate the triggering processes underlying each failure mechanism. We show that a large debris formation is mostly triggered by tensile stresses while shear stresses lead to small or no particle formation. We also study groups of junctions and discuss how microcontact interactions can be favored in some geometries to form macro-particles. This leads us to propose a classification in terms of macroscopic wear rate. Although based on a continuum approach, our phase-field calculations are able to effectively capture the failure of adhesive junctions, as observed through discrete Molecular Dynamics simulations.

Formation of self-layered hydrothermal coating on magnesium aided by titanium ion implantation: Synergistic control of corrosion resistance and cytocompatibility

The self-layered phenomenon has been observed from the hydrothermal processing of magnesium and Mg alloys, but it is still difficult to controllably fabricate a self-layered hydrothermal (SLH) coating due to the unclear formation mechanism and complex influencing factors. In this work, titanium ion implantation is adopted as a trigger process to modify the surface of pure magnesium and induce the formation of self-layered hydrothermal film. Compared to the conventional hydrothermal process that yields a relatively smooth and single-layer coating on pure magnesium, this new method produces a magnesium hydroxide-based SLH coating composed of an inner compact layer and outer nanosheet-based layer. Characterization results show that a Ti-implantation layer with titanium nanocrystals embedded in Mg matrix was formed after Ti-ion implantation. The galvanic effect between Ti nanocrystal and magnesium matrix accelerates corrosion and consequently, Mg(OH)2 nanosheets are formed from precipitation in the rapidly supersaturated solution of magnesium ions and hydroxide ions. For the as-prepared SLH coating, the inner compact layer provides good corrosion protection, while the outer layer improves functional properties such as cell adhesion and cytocompatibility. With synergistic improvement of corrosion resistance and cytocompatibility, the ion implantation-induced SLH coating is promising for further application in biomedical magnesium materials.

A hybrid machine-learning model to estimate potential debris-flow volumes

Empirical-statistical models of debris-flow are challenging to implement in environments where sedimentary and hydrologic triggering processes change through time, such as after a large earthquake. The flexible and adaptive statistical methods provided by machine learning algorithms may improve the quality of debris flow predictions where triggering conditions and the nature of sediment that can bulk flows varies with time. We developed a hybrid machine-learning model of future debris-flow volumes using a dataset of measured debris-flow volumes from 60 catchments that generated post-Wenchuan Earthquake (Mw 7.9) debris flows. We input topographic variables (catchment area, topographic relief, channel length, distance from seismic fault, and average channel gradient) and the total volume of co-seismic landslide debris into the PSO-ELM_AdaBoost machine-learning model, created by combining Extreme learning machine (ELM), particle swarm optimization (PSO) and adaptive boosting machine learning algorithm (AdaBoost). The model was trained and tested using post-2008 Mw 7.9 Wenchuan Earthquake debris flows, then applied to understand potential volumes of post-earthquake debris flows associated with other regional earthquakes (2013 Mw 6.6 Lushan Earthquake, 2010 Mw 6.9 Yushu Earthquake). We compared the PSO-ELM_Adaboost method with different machine learning methods, including back-propagation neural network (BPNN), support vector machine (SVM), ELM, PSO-ELM. The Comparative analysis demonstrated that the PSO-ELM_Adaboost method has a higher statistical validity and prediction accuracy with a mean absolute percentage error (MAPE) less than 0.10. The prediction accuracy of debris-flow volumes trigged by other earthquakes decreases to 0.11–0.16 (absolute percentage error), suggesting that once calibrated for a region this method can be applied to other regional earthquakes. This model may be useful for engineering design to mitigate the risk of large post-earthquake debris flows.

Dust devil triggering of slope streaks on Mars

Slope streaks are gravity-driven landforms that occur throughout the martian year in dust-rich equatorial regions on Mars. The distinctive streaks predominantly originate from point sources showing no indication for a specific trigger mechanism. Rare observations revealed dust devil-related triggering of multiple slope streaks and thus indicate a dry triggering process.

Improved approach for stress drop estimation and its application to an induced earthquake sequence in Oklahoma

SUMMARYWe calculate source parameters for fluid-injection induced earthquakes near Guthrie, Oklahoma, guided by synthetic tests to quantify uncertainties. The average stress drop during an earthquake is a parameter fundamental to ground motion prediction and earthquake source physics, but it has proved hard to measure accurately. This has limited our understanding of earthquake rupture, as well as the spatio-temporal variations of fault strength. We use synthetic tests based on a joint spectral-fitting method to define the resolution limit of the corner frequency as a function of the maximum frequency of usable signal, for both individual spectra and the average from multiple stations. Synthetic tests based on stacking analysis find that an improved stacking approach can recover the true input stress drop if the corner frequencies are within the resolution limit defined by joint spectral-fitting. We apply the improved approach to the Guthrie sequence, using different wave types and signal-to-noise criteria to understand the stability of the calculated stress drop values. The results suggest no systematic scaling relationship of stress drop for M ≤ 3.1 earthquakes, but larger events (M ≥ 3.5) tend to have higher average stress drops. Some robust spatio-temporal variations can be linked to the triggering processes and indicate possible stress heterogeneity within the fault zone. Tight clustering of low stress drop events at the beginning stage of the sequence suggests that pore pressure influences earthquake source processes. Events at shallow depth have lower stress drop compared to deeper events. The largest earthquake occurred within a cluster of high stress drop events, likely rupturing a strong asperity.

Industry 4.0: changes in work organization and qualification requirements\u2014challenges for academic and vocational education

The following article is based on the observation that digitalisation in the world of work does on the one hand trigger processes of change, leading to shifts and new constellations in the required qualifications. On the other hand, the effects of digitalisation on qualification requirements are moderated by work organisation. Against the background of a generalist understanding of academic and vocational qualifications, the article deals with the question what curricula correspond to the changing requirements of digitalisation under the new organizational circumstances of Industry 4.0. Turning to the discussion of preparatory qualifications for occupations in Industry 4.0, it follows the hypothesis that the technological developments that lead to a change in qualification needs also increase the potential to meet those needs. This leads to the idea of a digital signature pedagogy.