A review of topographic controls on moraine distribution

Ice-marginal moraines are often used to reconstruct the dimensions of former ice masses, which are then used as proxies for palaeoclimate. This approach relies on the assumption that the distribution of moraines in the modern landscape is an accurate reflection of former ice margin positions during climatically controlled periods of ice margin stability. However, the validity of this assumption is open to question, as a number of additional, nonclimatic factors are known to influence moraine distribution. This review considers the role played by topography in this process, with specific focus on moraine formation, preservation, and ease of identification (topoclimatic controls are not considered). Published literature indicates that the importance of topography in regulating moraine distribution varies spatially, temporally, and as a function of the ice mass type responsible for moraine deposition. In particular, in the case of ice sheets and ice caps ( > 1000km 2 ), one potentially important topographic control on where in a landscape moraines are deposited is erosional feedback, whereby subglacial erosion causes ice masses to become less extensive over successive glacial cycles. For the marine-terminating outlets of such ice masses, fjord geometry also exerts a strong control on where moraines are deposited, promoting their deposition in proximity to valley narrowings, bends, bifurcations, where basins are shallow, and/or in the vicinity of topographic bumps. Moraines formed at the margins of ice sheets and ice caps are likely to be large and readily identifiable in the modern landscape. In the case of icefields and valley glaciers (10-1000km 2 ), erosional feedback may well play some role in regulating where moraines are deposited, but other factors, including variations in accumulation area topography and the propensity for moraines to form at topographic pinning points, are also likely to be important. This is particularly relevant where land-terminating glaciers extend into piedmont zones (unconfined plains, adjacent to mountain ranges) where large and readily identifiable moraines can be deposited. In the case of cirque glaciers ( < 10km 2 ), erosional feedback is less important, but factors such as topographic controls on the accumulation of redistributed snow and ice and the availability of surface debris, regulate glacier dimensions and thereby determine where moraines are deposited. In such cases, moraines are likely to be small and particularly susceptible to post-depositional modification, sometimes making them difficult to identify in the modern landscape. Based on this review, we suggest that, despite often being difficult to identify, quantify, and mitigate, topographic controls on moraine distribution should be explicitly considered when reconstructing the dimensions of palaeoglaciers and that moraines should be judiciously chosen before being used as indirect proxies for palaeoclimate (i.e., palaeoclimatic inferences should only be drawn from moraines when topographic controls on moraine distribution are considered insignificant). © 2014 Elsevier B.V

Komorbidität und deren zeitliche Charakteristika bei Patienten mit Zwangsstörung

In der vorliegenden Studie wurden 70 Patienten mit der Diagnose einer Zwangsstörung und 65 Verwandte ersten Grades anhand des halbstrukturierten, DSM-IV-basierenden Interviews SADS-LA-IV exploriert. Besondere Aufmerksamkeit wurde zeitlichen Zusammenhängen von Symptomen und Störungen gewidmet. Unter den Patienten bestanden hohe komorbide Lebenszeitdiagnosen für affektive Störungen und Angststörungen. Es konnten anhand der psychiatrischen Erstmanifestation zwei Verlaufsformen der Zwangsstörung differenziert werden, die sich in Prädisposition, lebenszeitlichem Verlauf und der Bindung zum Formenkreis der Angststörungen unterschieden. Ein Teil der Patienten hatte eine hohe Vulnerabilität für Angststörungen. Hier war die Erstmanifestation einer psychiatrischen Störung eine spezifische oder soziale Phobie mit Beginn im Schulalter. Das Alter bei Beginn der Zwangsstörung war bei diesem Teil der Patienten höher als im Durchschnitt. Im Gegensatz dazu zeigten Patienten, die zuerst an einer Zwangsstörung erkrankten, ein niedrigeres Alter bei Beginn der Zwangsstörung und eine deutlich niedrigere Bereitschaft, weitere Angststörungen zu entwickeln: die durchschnittliche Anzahl der Angststörungen pro Person lag signifikant unter der der übrigen Patienten.In this study, 70 patients with the diagnosis of an obsessive-compulsive disorder and 65 first-degree relatives were explored using the DSM-IV based, semi-structured SADS-LA-IV interview. Special attention was paid to the course of symptoms and disorders. High lifetime prevalence rates for comorbide affective and anxiety disorders were found in this study. Two types of courses of obsessive-compulsive disorders could be differentiated by the disorder of first onset. Patients with social and specific phobia as first psychiatric disorder had a higher vulnerability for additional anxiety disorders. Age of onset of obsessive-compulsive disorder was higher in this group. Patients with obsessive-compulsive disorder as first psychiatric disorder had a significantly lower age of onset and a significantly lower vulnerability for additional anxiety disorders compared to the average of the study sample

ViroCon: A software to compute multivariate extremes using the environmental contour method

The environmental contour method is used by researchers and practitioners to define multivariate extremes of environmental conditions. These extreme conditions are then used to design or analyze marine structures. Here, we present a software called ViroCon, which implements different environmental contour methods. ViroCon is separated into two packages. One package is dedicated to the statistical computations and one package holds an easy-to-use graphical user interface. We expect that ViroCon will help researchers working on marine structures to better pursuit research questions concerning structural reliability by providing an easy-to-use and extendable software to compute extreme environmental conditions. Keywords: Marine structures, Probabilistic design, Extreme value statistic