Insurance with multiple insurers: A game-theoretic approach

This paper studies the set of Pareto optimal insurance contracts and the core of an insurance game. Our setting allows multiple insurers with translation invariant preferences. We characterise the Pareto optimal contracts, which determines the shape of the indemnities. Closed-form and numerical solutions are found for various preferences that the insurance players might have. Determining associated premiums with any given optimal Pareto contract is another problem for which economic-based arguments are further discussed. We also explain how one may link the recent fast growing literature on risk-based optimality criteria to the Pareto optimality criterion and we show that the latter is much more general than the former one, which according to our knowledge, has not been pointed out by now. Further, we extend some of our results when model risk is included, i.e. there is some uncertainty with the risk model and/or the insurance players make decisions based on divergent beliefs about the underlying risk. These robust optimal contracts are investigated and we show how one may find robust and Pareto efficient contracts, which is a key decision-making problem under uncertainty

Influence of injection volume and solvent strength on spilantholchromatography using RP fused-core amide stationary phase

For high-throughput purposes, newly developed Fused-Core HPLC stationary phases (HALO® columns) have attracted the interest of the chromatographic community. Due to their small particle size (2.7 μm) and unique particle technology with 0.5 μm porous shell fused to a solid core particle (1.7 µm diameter), these columns create fast and high performance separations. For our skin research, in vitro FDC experiments are performed, resulting in large sample numbers of low concentrated bio-active in physiologic receptor media (e.g. PBS). Spilanthol, present in Spilanthes acmella as most prominent N-alkylamide and having promising transdermal activity [1, 2], could be analyzed in reversed-phase mode on the HALO® amide stationary phase with methanol/H2O (70/30, V/V) acified with 1% formic acid as mobile phase. The influence of the injection volume and the sample solvent composition on six chromatographic characteristics characteristics (retention time, area, height, theoretical plate, symmetry factor and limit of detection) was investigated. Applying different injection volumes (2–100 µl), the chromatographic responses were obtained from a Spilanthes extract, dissolved in a purely aqueous (PBS) as well as methanol-based (70/30, V/V) sample solvent. Our results show that the chromatographic characteristics are highly dependent on the injection volume and solvent strength

New N-alkylamides from Anacyclus pyrethrum

The roots of Anacyclus pyrethrum DC (Asteraceae) are frequently used in traditional medicine e.g. as aphrodisiac [1]. Depending on the extraction method and solvent, different yields of N-alkylamide constituents can be found, possibly resulting in alterations in biological effects and toxicity. Therefore, analytical profiling of the bio-active N-alkylamides in these plant preparations is an inevitable quality parameter, with liquid chromatography-electrospray mass spectrometry (HPLC/ESI-MS) as recommended technique for comprehensive analysis of alkylamides in plant extracts [2-4].An N-alkylamide profiling from an ethanolic Anacyclus pyrethrum root extract was performed using a gradient reversed phase HPLC/ESI-MS method on an embedded polar column. MS1 and MS2 fragmentation data were used for identification purposes, while UV was used for quantification. Thirteen N-alkylamides (five N-isobutylamides, three N-methyl isobutylamides, four tyramides and one 2-phenylethylamide) were detected. Five of are novel compounds, which have never been identified in Anacyclus pyrethrum or other plants: Acknowledgements: Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen) (no. 091257) and the All India Council for Technical Education, New Delhi, India. References: 1. Sharma, V., Thakur, M., Chauhan, N., Dixit, V. 2010 Planta Med 76:1214-1214. 2. Sharma, V., Boonen, J., Chauhan, N., Thakur, M. De Spiegeleer, B., Dixit, V. 2011 Phytomedicine, In press. 3. Kartal, M., Kan, Y., Gulpinar, A. R. 2007 Planta Med 73:253. 4. Boonen, J., Baert, B., Burvenich, C., Blondeel, P., De Saeger, S., De Spiegeleer, B. 2010 J Pharmaceut Biomed 53:243-249

Une faune à conodontes du tournaisien dans le massif de la Vesdre

A conodont fauna is recorded from the Etroeungt and Pont d'Arcole Formations and from the base of the Landelies Formation in the Vesdre Massif ofBelgium. It is proposed to retain the name "Dolomie de la Vesdre" for the dolomites situated above the basal part of the Landelies Formation. This unit is the same as the "Obere Dolomit" in the German part of the massif