TY - JOUR A1 - Donat, Matthias A1 - Knigge, Michel A1 - Dalbert, Claudia T1 - Being a good or a just teacher BT - Which experiences of teachers’ behavior can be more predictive of school bullying? JF - Aggressive behavior : a multidisciplinary journal devoted to the experimental and observational analysis of conflict in humans and animals N2 - In two cross-sectional questionnaire studies with N = 2,931 German students, aged between 12 and 17 years (M = 14.1, SD = 0.5), we investigated the relation between students’ bullying behavior and their personal belief in a just world (BJW). We considered students’ personal experience of teacher justice as a possible mediator in this relation and investigated whether the students’ experiences of their teachers’ classroom management explained bullying behavior in addition to personal BJW and teacher justice, while statistically controlling for sex and school type. In both studies, multilevel modeling results showed that the more students endorsed personal BJW and the more they evaluated their teachers’ behavior toward them personally as being just, the less likely they were to report that they bullied others. The students’ personal experience of teacher justice mediated the association of personal BJW with bullying. Furthermore, the students’ personal experience of classroom management significantly predicted bullying in addition to personal BJW and teacher justice. The observed relations were mainly significant at the individual level. The pattern of results persisted when we controlled for school type and when we considered student sex as a moderator. We discussed the adaptive functions of BJW and implications for future school research and practice. KW - belief in a just world KW - bullying behavior KW - classroom management KW - multilevel modeling KW - teacher justice Y1 - 2018 U6 - https://doi.org/10.1002/ab.21721 SN - 0096-140X SN - 1098-2337 VL - 44 IS - 1 SP - 29 EP - 39 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Merks, Anne Margarete A1 - Swinarski, Marie A1 - Meyer, Alexander Matthias A1 - Müller, Nicola Victoria A1 - Özcan, Ismail A1 - Donat, Stefan A1 - Burger, Alexa A1 - Gilbert, Stephen A1 - Mosimann, Christian A1 - Abdelilah-Seyfried, Salim A1 - Panakova, Daniela T1 - Planar cell polarity signalling coordinates heart tube remodelling through tissue-scale polarisation of actomyosin activity JF - Nature Communications N2 - Development of a multiple-chambered heart from the linear heart tube is inherently linked to cardiac looping. Although many molecular factors regulating the process of cardiac chamber ballooning have been identified, the cellular mechanisms underlying the chamber formation remain unclear. Here, we demonstrate that cardiac chambers remodel by cell neighbour exchange of cardiomyocytes guided by the planar cell polarity (PCP) pathway triggered by two non-canonical Wnt ligands, Wnt5b and Wnt11. We find that PCP signalling coordinates the localisation of actomyosin activity, and thus the efficiency of cell neighbour exchange. On a tissue-scale, PCP signalling planar-polarises tissue tension by restricting the actomyosin contractility to the apical membranes of outflow tract cells. The tissue-scale polarisation of actomyosin contractility is required for cardiac looping that occurs concurrently with chamber ballooning. Taken together, our data reveal that instructive PCP signals couple cardiac chamber expansion with cardiac looping through the organ-scale polarisation of actomyosin-based tissue tension. Y1 - 2018 U6 - https://doi.org/10.1038/s41467-018-04566-1 SN - 2041-1723 VL - 9 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Hammer, Conny A1 - Fäh, Donat A1 - Ohrnberger, Matthias T1 - Automatic detection of wet-snow avalanche seismic signals JF - Natural hazards : journal of the International Society for the Prevention and Mitigation of Natural Hazards N2 - Avalanche activity is an important factor when estimating the regional avalanche danger. Moreover, a complete and detailed picture of avalanche activity is needed to understand the processes that lead to natural avalanche release. Currently, information on avalanche activity is mainly obtained through visual observations. However, this involves large uncertainties in the number and release times, influencing the subsequent analysis. Therefore, alternative methods for the remote detection of snow avalanches in particular in non-observed areas are highly desirable. In this study, we use the excited ground vibration to identify avalanches automatically. The specific seismic signature of avalanches facilitates the objective detection by a recently developed classification procedure. A probabilistic description of the signals, called hidden Markov models, allows the robust identification of corresponding signals in the continuous data stream. The procedure is based upon learning a general background model from continuous seismic data. Then, a single reference waveform is used to update an event-specific classifier. Thus, a minimum amount of training data is required by constructing such a classifier on the fly. In this study, we processed five days of continuous data recorded in the Swiss Alps during the avalanche winter 1999. With the restriction of testing large wet-snow avalanches only, the presented approach achieved very convincing results. We successfully detect avalanches over a large volume and distance range. Ninety-two percentage of all detections (43 out of 47) could be confirmed as avalanche events; only four false alarms are reported. We see a clear dependence of recognition capability on run-out distance and source-receiver distance of the observed events: Avalanches are detectable up to a source-receiver distance of eight times the avalanche length. Implications for analyzing a more comprehensive data set (smaller events and different flow regimes) are discussed in detail. KW - Snow avalanche recognition KW - Automatic detection KW - Avalanche forecasting KW - Hidden Markov model Y1 - 2016 U6 - https://doi.org/10.1007/s11069-016-2707-0 SN - 0921-030X SN - 1573-0840 VL - 86 SP - 601 EP - 618 PB - Springer CY - New York ER - TY - JOUR A1 - Hammer, Conny A1 - Ohrnberger, Matthias A1 - Faeh, Donat T1 - Classifying seismic waveforms from scratch: a case study in the alpine environment JF - Geophysical journal international N2 - Nowadays, an increasing amount of seismic data is collected by daily observatory routines. The basic step for successfully analyzing those data is the correct detection of various event types. However, the visually scanning process is a time-consuming task. Applying standard techniques for detection like the STA/LTAtrigger still requires the manual control for classification. Here, we present a useful alternative. The incoming data stream is scanned automatically for events of interest. A stochastic classifier, called hidden Markov model, is learned for each class of interest enabling the recognition of highly variable waveforms. In contrast to other automatic techniques as neural networks or support vector machines the algorithm allows to start the classification from scratch as soon as interesting events are identified. Neither the tedious process of collecting training samples nor a time-consuming configuration of the classifier is required. An approach originally introduced for the volcanic task force action allows to learn classifier properties from a single waveform example and some hours of background recording. Besides a reduction of required workload this also enables to detect very rare events. Especially the latter feature provides a milestone point for the use of seismic devices in alpine warning systems. Furthermore, the system offers the opportunity to flag new signal classes that have not been defined before. We demonstrate the application of the classification system using a data set from the Swiss Seismological Survey achieving very high recognition rates. In detail we document all refinements of the classifier providing a step-by-step guide for the fast set up of a well-working classification system. KW - Time series analysis KW - Neural networks, fuzzy logic KW - Seismic monitoring and test-ban treaty verification KW - Early warning KW - Probability distributions Y1 - 2013 U6 - https://doi.org/10.1093/gji/ggs036 SN - 0956-540X SN - 1365-246X VL - 192 IS - 1 SP - 425 EP - 439 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Lontsi, Agostiny Marrios A1 - Garcia-Jerez, Antonio A1 - Camilo Molina-Villegas, Juan A1 - Jose Sanchez-Sesma, Francisco A1 - Molkenthin, Christian A1 - Ohrnberger, Matthias A1 - Krüger, Frank A1 - Wang, Rongjiang A1 - Fah, Donat T1 - A generalized theory for full microtremor horizontal-to-vertical [H/V(z,f)] spectral ratio interpretation in offshore and onshore environments JF - Geophysical journal international N2 - Advances in the field of seismic interferometry have provided a basic theoretical interpretation to the full spectrum of the microtremor horizontal-to-vertical spectral ratio [H/V(f)]. The interpretation has been applied to ambient seismic noise data recorded both at the surface and at depth. The new algorithm, based on the diffuse wavefield assumption, has been used in inversion schemes to estimate seismic wave velocity profiles that are useful input information for engineering and exploration seismology both for earthquake hazard estimation and to characterize surficial sediments. However, until now, the developed algorithms are only suitable for on land environments with no offshore consideration. Here, the microtremor H/V(z, f) modelling is extended for applications to marine sedimentary environments for a 1-D layered medium. The layer propagator matrix formulation is used for the computation of the required Green’s functions. Therefore, in the presence of a water layer on top, the propagator matrix for the uppermost layer is defined to account for the properties of the water column. As an application example we analyse eight simple canonical layered earth models. Frequencies ranging from 0.2 to 50 Hz are considered as they cover a broad wavelength interval and aid in practice to investigate subsurface structures in the depth range from a few meters to a few hundreds of meters. Results show a marginal variation of 8 per cent at most for the fundamental frequency when a water layer is present. The water layer leads to variations in H/V peak amplitude of up to 50 per cent atop the solid layers. KW - Numerical modelling KW - Earthquake hazards KW - Seismic interferometry KW - Site effects KW - Theoretical seismology KW - Wave propagation Y1 - 2019 U6 - https://doi.org/10.1093/gji/ggz223 SN - 0956-540X SN - 1365-246X VL - 218 IS - 2 SP - 1276 EP - 1297 PB - Oxford Univ. Press CY - Oxford ER - TY - GEN A1 - Merks, Anne Margarete A1 - Swinarski, Marie A1 - Meyer, Alexander Matthias A1 - Müller, Nicola Victoria A1 - Özcan, Ismail A1 - Donat, Stefan A1 - Burger, Alexa A1 - Gilbert, Stephen A1 - Mosimann, Christian A1 - Abdelilah-Seyfried, Salim A1 - Panáková, Daniela T1 - Planar cell polarity signalling coordinates heart tube remodelling through tissue-scale polarisation of actomyosin activity T2 - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe N2 - Development of a multiple-chambered heart from the linear heart tube is inherently linked to cardiac looping. Although many molecular factors regulating the process of cardiac chamber ballooning have been identified, the cellular mechanisms underlying the chamber formation remain unclear. Here, we demonstrate that cardiac chambers remodel by cell neighbour exchange of cardiomyocytes guided by the planar cell polarity (PCP) pathway triggered by two non-canonical Wnt ligands, Wnt5b and Wnt11. We find that PCP signalling coordinates the localisation of actomyosin activity, and thus the efficiency of cell neighbour exchange. On a tissue-scale, PCP signalling planar-polarises tissue tension by restricting the actomyosin contractility to the apical membranes of outflow tract cells. The tissue-scale polarisation of actomyosin contractility is required for cardiac looping that occurs concurrently with chamber ballooning. Taken together, our data reveal that instructive PCP signals couple cardiac chamber expansion with cardiac looping through the organ-scale polarisation of actomyosin-based tissue tension. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 849 KW - convergent extension KW - branching morphogenesis KW - actin cytoskeleton KW - zebrafish heart KW - mouse heart KW - drosophila KW - cadherin KW - gene KW - differentiation KW - proliferation Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427026 SN - 1866-8372 IS - 849 ER -