Compounds, isolated from the bacteria Xenorhabdus bovienil, have antineoplastic activity. The compounds are inhibitors of the processing of APP by gamma-secretase, and hence are useful in the treatment or prevention of Alzheimer’s disease. For example, a virtual router may receive various messages that include encoded audio corresponding to a natural language utterance contained in a multi-modal interaction provided to one or more of the devices. The fixing element is arranged on the outer front side of the cover so as to be pivotable such that the fixing element can be displaced essentially parallel to the front side of the cover.