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Large earthquakes are usually modeled with simple planar fault surfaces or a combination of several planar fault segments. However, in general, earthquakes occur on faults that are non-planar and exhibit significant geometrical variations in both the along-strike and down-dip directions at all spatial scales. Mapping of surface fault ruptures and high-resolution geodetic observations are increasingly revealing complex fault geometries near the surface and accurate locations of aftershocks often indicate geometrical complexities at depth. With better geodetic data and observations of fault ruptures, more details of complex fault geometries can be estimated resulting in more realistic fault models of large earthquakes. To address this topic, we here parametrize non-planar fault geometries with a set of polynomial parameters that allow for both along-strike and down-dip variations in the fault geometry. Our methodology uses Bayesian inference to estimate the non-planar fault parameters from geodetic data, yielding an ensemble of plausible models that characterize the uncertainties of the non-planar fault geometry and the fault slip. The method is demonstrated using synthetic tests considering slip spatially distributed on a single continuous finite non-planar fault surface with varying dip and strike angles both in the down-dip and along-strike directions. The results show that fault-slip estimations can be biased when a simple planar fault geometry is assumed in presence of significant non-planar geometrical variations. Our method can help to model earthquake fault sources in a more realistic way and may be extended to include multiple non-planar fault segments or other geometrical fault complexities.
Tula orthohantavirus (TULV) is a rodent-borne hantavirus with broad geographical distribution in Europe. Its major reservoir is the common vole (Microtus arvalis), but TULV has also been detected in closely related vole species. Given the large distributional range and high amplitude population dynamics of common voles, this host-pathogen complex presents an ideal system to study the complex mechanisms of pathogen transmission in a wild rodent reservoir. We investigated the dynamics of TULV prevalence and the subsequent potential effects on the molecular evolution of TULV in common voles of the Central evolutionary lineage. Rodents were trapped for three years in four regions of Germany and samples were analyzed for the presence of TULV-reactive antibodies and TULV RNA with subsequent sequence determination. The results show that individual (sex) and population-level factors (abundance) of hosts were significant predictors of local TULV dynamics. At the large geographic scale, different phylogenetic TULV clades and an overall isolation-by-distance pattern in virus sequences were detected, while at the small scale (<4 km) this depended on the study area. In combination with an overall delayed density dependence, our results highlight that frequent, localized bottleneck events for the common vole and TULV do occur and can be offset by local recolonization dynamics.
Comb-like geometric constraints leading to emergence of the time-fractional Schrödinger equation
(2021)
This paper presents an overview over several examples, where the comb-like geometric constraints lead to emergence of the time-fractional Schrodinger equation. Motion of a quantum object on a comb structure is modeled by a suitable modification of the kinetic energy operator, obtained by insertion of the Dirac delta function in the Laplacian. First, we consider motion of a free particle on two- and three-dimensional comb structures, and then we extend the study to the interacting cases. A general form of a nonlocal term, which describes the interactions of the particle with the medium, is included in the Hamiltonian, and later on, the cases of constant and Dirac delta potentials are analyzed. At the end, we discuss the case of non-integer dimensions, considering separately the case of fractal dimension between one and two, and the case of fractal dimension between two and three. All these examples show that even though we are starting with the standard time-dependent Schrodinger equation on a comb, the time-fractional equation for the Green's functions appears, due to these specific geometric constraints.
Epistemic logic programs constitute an extension of the stable model semantics to deal with new constructs called subjective literals. Informally speaking, a subjective literal allows checking whether some objective literal is true in all or some stable models. As it can be imagined, the associated semantics has proved to be non-trivial, since the truth of subjective literals may interfere with the set of stable models it is supposed to query. As a consequence, no clear agreement has been reached and different semantic proposals have been made in the literature. Unfortunately, comparison among these proposals has been limited to a study of their effect on individual examples, rather than identifying general properties to be checked. In this paper, we propose an extension of the well-known splitting property for logic programs to the epistemic case. We formally define when an arbitrary semantics satisfies the epistemic splitting property and examine some of the consequences that can be derived from that, including its relation to conformant planning and to epistemic constraints. Interestingly, we prove (through counterexamples) that most of the existing approaches fail to fulfill the epistemic splitting property, except the original semantics proposed by Gelfond 1991 and a recent proposal by the authors, called Founded Autoepistemic Equilibrium Logic.
Earthquake source parameters such as seismic stress drop and corner frequency are observed to vary widely, leading to persistent discussion on potential scaling of stress drop and event size. Physical mechanisms that govern stress drop variations arc difficult to evaluate in nature and are more readily studied in controlled laboratory experiments. We perform two stick-slip experiments on fractured (rough) and cut (smooth) Westerly granite samples to explore fault roughness effects on acoustic emission (AE) source parameters. We separate large stick-slip events that generally saturate the seismic recording system from populations of smaller AE events which are sensitive to fault stresses prior to slip. AE event populations show many similarities to natural seismicity and may be interpreted as laboratory equivalent of natural microseismic events. We then compare the temporal evolution of mechanical data such as measured stress release during slip to temporal changes in stress drops derived from Alis using the spectral ratio technique. We report on two primary observations: (1) In contrast to most case studies for natural earthquakes, we observe a strong increase in seismic stress drop with AE size. (2) The scaling of stress drop with magnitude is governed by fault roughness, whereby the rough fault shows a more rapid increase of the stress drop magnitude relation with progressing large stick-slip events than the smooth fault. The overall range of AE sizes on the rough surface is influenced by both the average grain size and the width of the fault core. The magnitudes of the smallest AE events on smooth faults may also be governed by grain size. However, AEs significantly grow beyond peak roughness and the width of the fault core. Our laboratory tests highlight that source parameters vary substantially in the presence of fault zone heterogeneity (i.e. roughness and narrow grain size distribution), which may affect seismic energy partitioning and static stress drops of small and large AE events.
One of the main challenges of education in modern societies is to effectively address the variability of students in academic learning settings. Students vary in terms of their individual learning preconditions, such as achievement and preknowledge, but also motivation and emotion. Teachers, in turn, have limited resources to provide each learner with individually tailored instruction. This research overview reviews research on artificially intelligent teaching assistants and their role in providing adaptive learning opportunities in relation to learners’ heterogeneous individual learning preconditions in the field of motivation and emotion.
Im Hochmittelalter entstehen Erzählungen, die etablierte literarische Formen und Traditionen neu verbinden: Sie sind volkssprachig, allegorisch und verwenden als Erzählform die erste Person, um in dieser Kombination, die sich zu einem die Grenzen der Einzelsprachen überschreitenden Erzähl-Format verfestigt, unterschiedlichste Themen aufzugreifen. Dieses Format, erstmals realisiert im altfranzösischen Roman de la Rose, wird die europäische Literatur mit Texten wie Dantes Divina Comedia, Guillaumes de Deguileville Pèlerinage de la Vie Humaine, William Langlands Pierce Plowman und Christines de Pizan Le Livre de la mutation de Fortune bis weit in die Neuzeit hinein prägen. Der in den Band einleitende Beitrag geht der Frage nach, ob das narrative Format dabei universell verwendet wird oder, z.B. im Rahmen der Liebesdichtung, spezifische Besonderheiten aufweist.
Nationalism was declared to be dead too early. A postnational age was announced, and liberalism claimed to have been victorious by the end of the Cold War. At the same time postnational order was proclaimed in which transnational alliances like the European Union were supposed to become more important in international relations. But we witnessed the rise a strong nationalism during the early 21st century instead, and right wing parties are able to gain more and more votes in elections that are often characterized by nationalist agendas. This volume shows how nationalist dreams and fears alike determine politics in an age that was supposed to witness a rather peaceful coexistence by those who consider transnational ideas more valuable than national demands. It will deal with different case studies to show why and how nationalism made its way back to the common consciousness and which elements stimulated the re-establishment of the aggressive nation state. The volume will therefore look at the continuities of empire, actual and imagined, the role of "foreign-" and "otherness" for nationalist narratives, and try to explain how globalization stimulated the rise of 21st century nationalisms as well.
Religious Mapping Erbil (RME) is a joint project of teams from the Catholic University in Erbil (CUE), Salahaddin University-Erbil (SUE) and Tishk International University (TIU) under the guidance of the University of Potsdam (UP). From 2018 to 2022, the project was financed by the German Academic Exchange Service (DAAD).
This project involves scholars of various disciplines including religious studies, Islamic studies, English language, applied computing, and computer engineering. The research is a cooperation of students, PhD candidates and advanced scholars.
The project attempts to display the religious diversity in Erbil, the fast-changing capital of Iraqi Kurdistan. Unlike a census or a survey, which focuses on individuals, RME presents the locations (mosques, churches, synagogues, temples and other venues) together with the history and social profiles of the congregations meeting there. [insert tiny map or part of it]
The data were obtained by visiting the locations, observing their services, interviewing community leaders (mostly imams and priests), evaluating information from the Ministry of Endowment and Religious Affairs, and by consulting websites. All investigations followed the same pattern, consisting of (I) spatiotemporal and (III) social dimensions, framed by (II) religious performance.