L. A. Hothorn

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A field study was conducted in Germany to determine the possible effects of transgenic maize cultivation on nontarget epigeic predator organisms. During the growing period of 2001-2003, the activity abundances of spiders and carabid beetles were recorded and compared in three treatments: (1) Bt-maize (Mon 810) expressing the Cry1ab protein from Bacillus(More)
Genome-wide association studies have reported an association between the A-allele of rs1006737 within CACNA1C and affective disorders and schizophrenia. The aim of the present study was to investigate the relationship between rs1006737 and established and potential endophenotypes for these disorders in a population-based cohort of 3793 subjects, using an(More)
OBJECTIVES In this article, we illustrate and compare exact simultaneous confidence sets with various approximate simultaneous confidence intervals for multiple ratios as applied to many-to-one comparisons. Quite different datasets are analyzed to clarify the points. METHODS The methods are based on existing probability inequalities (e.g., Bonferroni,(More)
The safety assessment of Novel Food, including GM biotechnology-derived crops, starts with the comparison of the Novel Food with a traditional counterpart that is generally accepted as safe based on a history of human food use. Substantial equivalence is established if no meaningful difference from the conventional counterpart was found, leading to the(More)
This paper proposes a general approach for handling multiple contrast tests for normally distributed data in the presence of heteroscedasticity. Three candidate procedures are described and compared by simulations. Only the procedure with both comparison-specific degrees of freedom and a correlation matrix depending on sample variances maintains the(More)
Simultaneous confidence intervals for contrasts of means in a one-way layout with several independent samples are well established for Gaussian distributed data. Procedures addressing different hypotheses are available, such as all pairwise comparisons or comparisons to control, comparison with average, or different tests for order-restricted alternatives.(More)
In this paper, we describe an adjusted method to facilitate non-inferiority tests in a three-arm design. While the methodology is readily available in the situation of homogeneous group variances, the adjusted method will also maintain the alpha-level in the presence of heteroscedasticity. We propose explicit criteria for an optimal allocation. Depending on(More)
Usually, a monotone dose-response dependence can be assumed for the simultaneous comparison of increasing levels of a certain drug. However, sometimes a reversal of the dose-response curve is likely to occur at the higher doses. We investigate such violations of the monotonicity assumption. Adequate alternatives are discussed and the "protected trend(More)
Plants constantly renew during their life cycle and thus require to shed senescent and damaged organs. Floral abscission is controlled by the leucine-rich repeat receptor kinase (LRR-RK) HAESA and the peptide hormone IDA. It is unknown how expression of IDA in the abscission zone leads to HAESA activation. Here we show that IDA is sensed directly by the(More)
Developmental neurotoxicity (DNT) and many forms of reproductive toxicity (RT) often manifest themselves in functional deficits that are not necessarily based on cell death, but rather on minor changes relating to cell differentiation or communication. The fields of DNT/RT would greatly benefit from in vitro tests that allow the identification of(More)