Risk management of climate impact for tourism operators: An empirical analysis on ski resorts

The aim of this paper is to analyze the performance of hedging strategies based on snow andtemperature options developed by ski operators to protect their profitability under adversechanges in climatic conditions. The setup is based on a joint non-parametric model for snowand temperature aimed at providing a modelling support for the assessment of the impact ofthese weather variables on the number of visitors at the ski resort. The analysis is carried outconsidering the case of Austrian Alps, and examines: i) the ability of the proposed approach toprovide a realistic representation of the true data-generating process; ii) the variability reductionin the Profit and Loss of the ski operator offered by the suggested strategies; and iii) the tradeoffbetween the budget earmarked for hedging and profitability protection

Simultaneous confidence intervals by iteratively adjusted alpha for relative effects in the one-way layout.

A bootstrap based method to construct 1 � α simultaneous confidence intervals for relative effects in the one-way layout is presented. This procedure takes the stochastic correlation between the test statistics into account and results in narrower simultaneous confidence intervals than the application of the Bonferroni correction. Instead of using the bootstrap distribution of a maximum statistic, the coverage of the confidence intervals for the individual com- parisons are adjusted iteratively until the overall confidence level is reached. Empirical coverage and power estimates of the introduced procedure for many-to-one comparisons are presented and compared with asymptotic procedures based on the multivariate normal distribution

Establishing bioequivalence in complete and incomplete data designs using AUCs.

Nonclinical in vivo animal studies have to be completed before starting clinical studies of the pharmacokinetic behavior of a drug in humans. The drug exposure in animal studies is often measured by the area under the concentration versus time curve (AUC). The classical complete data design where each animal is sampled for analysis at every time point is applicable for large animals only. In the case of small animals, where blood sampling is restricted, the batch design or the serial sampling design need to be considered. In batch designs, samples are taken more than once from each animal, but not at all time points. In serial sampling designs, only one sample is taken from each animal. In this article we derive the asymptotic distribution for the ratio of two AUCs and construct different confidence intervals, which are frequently used to assess bioequivalence. The performance of these intervals is then evaluated between the different designs in a simulation study. Additionally, the sample sizes required for the different designs are compared

Non-compartmental estimation of pharmacokinetic parameters in serial sampling designs.

Pharmacokinetic studies are commonly analyzed using a two-stage approach where the first stage involves estimation of pharmacokinetic parameters for each subject separately and the second stage uses the individual parameter estimates for statistical inference. This two-stage approach is not applicable in sparse sampling situations where only one sample is available per subject. Nonlinear models are often applied to analyze pharmacokinetic data assessed in such serial sampling designs. Modelling approaches are suitable provided that the form of the true model is known, which is rarely the case in early stages of drug development. This paper presents an alternative approach to estimate pharmacokinetic parameters based on non-compartmental and asymptotic theory in the case of serial sampling when a drug is given as an intravenous bolus. The statistical properties of the estimators of the pharmacokinetic parameters are investigated and evaluated using Monte Carlo simulations

Recombinant ADAMTS13 normalizes von Willebrand factor-cleaving activity in plasma of acquired TTP patients by overriding inhibitory antibodies

Severe deficiency of the von Willebrand factor (VWF)-cleaving protease ADAMTS13 as observed in acquired thrombotic thrombocytopenic purpura (TTP) is caused by inhibitory and non-inhibitory autoantibodies directed against the protease. Current treatment with plasma exchange is considered to remove circulating antibodies and to concurrently replenish the deficient enzyme

Duration of the Snow Cover and the Need for Artificial Snow—A Challenge for Management in Ski-Centres of Serbia

The production and use of artificial snow has become necessary in most ski centres in Europe. The lack of snow creates problems in ski centres that were built without the prior valuation of natural factors. The survey covered winter tourist centres in Serbia, which are facing problems due to the shortening of the tourist season caused by the lack of snow cover on the ski slopes. The duration of the snow cover is the result of several factors. Air temperature changes were analysed in mountain tourist centres in Serbia, as well as at undeveloped destinations with a potential for snow sports. On the basis of the quantitative indicators of the air temperature and the methodology by means of which snowmaking is carried out, the time periods during the year for making artificial snow are presented. Due to the forecast rise in air temperature, the issue of profitability of artificial snow in the ski centres of Serbia remains open