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A rockfall dataset for Germany is analysed with the objective of identifying the meteorological and hydrological (pre-)conditions that change the probability for such events in central Europe. The factors investigated in the analysis are precipitation amount and intensity, freeze–thaw cycles, and subsurface moisture. As there is no suitable observational dataset for all relevant subsurface moisture types (e.g. water in rock pores and cleft water) available, simulated soil moisture and a proxy for pore water are tested as substitutes. The potential triggering factors were analysed both for the day of the event and for the days leading up to it. A logistic regression model was built, which considers individual potential triggering factors and their interactions. It is found that the most important factor influencing rockfall probability in the research area is the precipitation amount at the day of the event, but the water content of the ground on that day and freeze–thaw cycles in the days prior to the event also influence the hazard probability. Comparing simulated soil moisture and the pore-water proxy as predictors for rockfall reveals that the proxy, calculated as accumulated precipitation minus potential evaporation, performs slightly better in the statistical model. Using the statistical model, the effects of meteorological conditions on rockfall probability in German low mountain ranges can be quantified. The model suggests that precipitation is most efficient when the pore-water content of the ground is high. An increase in daily precipitation from its local 50th percentile to its 90th percentile approximately doubles the probability for a rockfall event under median pore-water conditions. When the pore-water proxy is at its 95th percentile, the same increase in precipitation leads to a 4-fold increase in rockfall probability. The occurrence of a freeze–thaw cycle in the preceding days increases the rockfall hazard by about 50 %. The most critical combination can therefore be expected in winter and at the beginning of spring after a freeze–thaw transition, which is followed by a day with high precipitation amounts and takes place in a region preconditioned by a high level of subsurface moisture.

Objective: To objectively assess the cervical paraspinal musculature of French bulldogs (FBs) using computed tomography (CT) scan-based measurements, outline differences in other breeds published in the literature, and investigate the potential influence of its cervical paraspinal musculature on predisposed sites for intervertebral disk disease. Animals: Thirty FBs that underwent CT scans of the cervical spine from the skull to C7/T1 were enrolled. Fifteen dogs were patients suffering from intervertebral disk herniation (IVDH group), and 15 dogs underwent CT scans due to brachycephalic obstructive airway syndrome (BOAS group). Methods: At the level of each cervical intervertebral disk from C2/C3 to C7/T1, measurements were performed and statistically analyzed. On the sagittal CT scan reconstruction, the height ratio of the dorsal to ventral paraspinal musculature and the angle of the disk axis to vertebral body length were assessed. On the transverse plane, the area ratio of the dorsal and ventral paraspinal musculature and the ratio of force moments were determined at each intervertebral disk level. Finally, ratios were compared to the values of Labrador retrievers and dachshunds published by Hartmann et al. (1). Results: Comparing the two FB groups, one significant difference was detected in the mean height ratio of the dorsal to ventral paraspinal musculature at the level of C5/C6 (P = 0.0092) and C6/C7 (P = 0.0076), with IVDH FBs having the more prominent dorsal paraspinal musculature. At the level of C3/C4, a significantly less prominent dorsal paraspinal musculature in FBs than in dachshunds (P = 0.0058) and a significantly steeper disk to vertebral body angulation were observed (P = 0.0005). Conclusion: Although some incidental differences were found, most parameters did not significantly differ between the BOAS and IVDH FBs. Significant conformational differences in the cervical paraspinal musculature and disk to vertebral body length angulation were found between FBs and two other breeds (chondrodystrophic and non-chondrodystrophic). This study's findings suggest that the paraspinal musculature is an additional biomechanical influencing factor on the preferential sites of IVDH in the cervical spine and that other major factors exist in IVDH development, especially in FBs.

In der vorliegenden Arbeit geht es um die Relativistische Schrödingertheorie (RST), welche eine neue Methode zur Behandlung relativistischer Mehrteilchensysteme darstellt. Die RST und die ihr zugrunde liegenden Konzepte, d.h. Eichtheorien und Faserbündel, werden kurz vorgestellt sowie der RST-Formalismus auf den 2-Teilchen Fall mit elektromagnetischer Wechselwirkung spezialisiert. Es wird bewiesen, daß die in der RST auftretenden Mischungs- und Austauscheffekte, welche die zwei Teilchen zusätzlich zur Eichwechselwirkung aneinander koppeln, keine physikalischen Auswirkungen haben, sofern sie nicht gemeinsam auftreten. Der Mischungseffekt läßt sich auf eine Gruppenstruktur, die sogenannte Mischungsgruppe, zurückführen. Zur Behandlung des Austauscheffektes werden neue Feldgrößen eingeführt, welche die RST-Dynamik stark vereinfachen und die Konstruktion einer Lagrange-Dichte für das 2-Teilchen-RST-Feldgleichungssystem ermöglichen. Die physikalischen Auswirkungen des gemeinsamen Auftretens von Mischungs- und Austauscheffekten werden durch die Berechnung der Bindungszustände des He-Atoms in erster Ordnung Störungstheorie und den Vergleich sowohl mit den experimentellen Werten als auch mit den Resultaten der konventionellen Quantentheorie verdeutlicht., The present work deals with Relativistic Schrödinger Theory (RST), which constitutes a new method for treating relativistic many-particle systems; the RST theory and the underlying concepts of gauge theories and fibre bundles are explained and the RST formalism is specialized to the case of 2-particle systems with electromagnetic interactions. It is shown that the RST mixture and exchange effects, which couple the two particles in addition to the gauge interactions, do only influence the physical content of the theory if they both occur simultaneously. The mixture effect is related to a group structure, the so-called mixing group. For the treatment of the exchange effect, new field variables are introduced which simplify the RST dynamics considerably, leading to a Lagrangian formulation of the RST field equations for two particles. The physical impact of the occurence of both mixture and exchange effects is exemplified by calculating the bound-state energy levels of the He-Atom in first order perturbation theory and by comparison with both experimental values and the results of conventional quantum theory.