On the clustering of winter storm loss events over Germany

During the last decades, several windstorm series hit Europe leading to large aggregated losses. Such storm series are examples of serial clustering of extreme cyclones, presenting a considerable risk for the insurance industry. Clustering of events and return periods of storm series for Germany are quantified based on potential losses using empirical models. Two reanalysis data sets and observations from German weather stations are considered for 30 winters. Histograms of events exceeding selected return levels (1-, 2- and 5-year) are derived. Return periods of historical storm series are estimated based on the Poisson and the negative binomial distributions. Over 4000 years of general circulation model (GCM) simulations forced with current climate conditions are analysed to provide a better assessment of historical return periods. Estimations differ between distributions, for example 40 to 65 years for the 1990 series. For such less frequent series, estimates obtained with the Poisson distribution clearly deviate from empirical data. The negative binomial distribution provides better estimates, even though a sensitivity to return level and data set is identified. The consideration of GCM data permits a strong reduction of uncertainties. The present results support the importance of considering explicitly clustering of losses for an adequate risk assessment for economical applications

The words for 'star' in Indo-European and Semitic

This article brings together two fields: (1) the traditional study of the lexicon of Proto-Indo-European (including the material culture and belief system of the prehistoric speakers of Proto-Indo-European) and (2) the traditional study of the lexicon of Proto-Semitic (also including the material culture and belief system of the prehistoric speakers of Proto-Semitic). In particular, this paper deals with the words for 'star' in Indo-European and Semitic. The main proposals concerning their possible origin are evaluated, and the most probable proposal is highlighted. In both cases, the underlying meaning for the words for 'star' turns out to be something like 'the burning, glowing, shining thing or object'

Voluntary business engagement in climate change: A study of the ClimateWise Principles

There is an expectation that the insurance sector should be leading business efforts in responding to climate change due to their inherent exposure to increasing risks. However, insurance companies normally operate on a one year time horizon - underwriting risks through policies which change each year to reflect new knowledge of these risks. The ClimateWise principles is a voluntary initiative of the insurance sector that was launched in 2007 to provide a basis for insurance companies to engage with climate change risks. This paper introduces the ClimateWise initiative and explores progress made since its launch. The paper presents new knowledge on whether this voluntary initiative provides a useful structure for the insurance sector in responding to the challenge of climate change. It finds that while the insurance sector has engaged with climate change, there is much more to do and we welcome the recent changes to ClimateWise that more accurately reflect this. The paper concludes that ClimateWise has been a useful initiative for the insurance companies and as a potential benchmark for the sector it offers some value. However, ClimateWise has not provided a strong enough engagement across the sector to embed climate action into business decisions

L’absence maternelle, matrice de Cendrillon de Joël Pommerat

S’engager dans une réflexion sur l’œuvre de Joël Pommerat pose une première difficulté. L’artiste ne cesse en effet de mettre en évidence son goût pour la complexité, l’incertain, le trouble – pour reprendre le titre de l’ouvrage de Joëlle Gayot. Nous amorçons ici une entreprise paradoxale lors de laquelle nous chercherons à mettre en lumière certains aspects d’un spectacle, sans pour autant nous laisser aveugler par une trop grande clarté. Ce n’est pas un hasard si la compagnie de l’artiste..

Development of a statistical daily precipitation model and its application to precipitation records

In recent years, numerous record-breaking precipitation events have caused several deaths and high economic losses. However, current precipitation models do not adequately capture exceptionally high precipitation events. To address this problem, a new statistical daily precipitation model including several new aspects was developed. The model distinguishes between stratiform and convective precipitation, whereby the disaggregation of these two types of precipitation is based on SYNOP reports of 300 German weather stations. By combining a Weibull distribution with power law, a new probability distribution was derived and later implemented in the amount process. This four-parameter distribution improves the modelling of extreme precipitation amounts enormously and still delivers good results for small amounts. To take account of variability, a confined random walk was additionally implemented in the occurrence process of the model. The model was developed in a manner that allows universal use. By incorporating the elevation of a station and the time of the year as input parameters, the model was made applicable at any time and for any location in Germany. In a second step the model was applied to investigate daily precipitation records. For that, linear changes were implemented into the model. As result, a previously found decrease of records in the summer season can be explained by changes in the stratiform precipitation distribution. However, the decrease of precipitation records in the summer season is too low to rule out random processes as cause of this decrease. In contrast, the increase in the mean number of precipitation records in winter season cannot be reproduced with the developed model. A possible explanation for that is the neglect of spatial correlations in the amount process. An appropriate method for taking spatial correlations into account, could be a Copula approach

Development of a tissue-engineered skin substitute on a base of human amniotic membrane

Allogenic graft material and tissue engineering have recently shown promising results for the improvement of both esthetic and functional outcomes in the treatment of large skin defects. We chose human amniotic membrane as a cellular scaffold in order to develop a skin substitute for later in vivo uses. Various methods of de-epithelialization of the human amniotic membrane were evaluated by histological analysis including hematoxylin-eosin and laminin staining, optic coherence tomography, and scanning electron microscopy with 0.25/0.02% trypsin/ethylenediaminetetraacetic acid treatment and mechanical cell removal showing an almost complete loss of the epithelium and a mainly intact basement membrane. Novel examination of human amniotic membrane by optic coherence tomography was feasible, but difficulties were experienced in handling and interpretation of the tissue as no comparable data exist. Subsequently, we developed an air-liquid interface cell culture to cultivate keratinocytes and fibroblasts on the de-epithelialized human amniotic membrane. We achieved a mostly keratinized surface on the epidermal side with a confluent fibroblast network on the chorion side