The focus control culture observation apparatus enable simple and reliable detection of a focusing position of an objective lens on a subject and with certainty. The network behavior of users of a computer-implemented social network are observed and used for user profiling. The capacitance of each second resonator C\u20142 is larger than the capacitance of each first resonator C\u20141. The system may also transform data from each of the plurality of data sources into a format that is compatible for combining the data from the plurality of data sources. The compounds are particularly suitable as antiarrhythmic active ingredients, in particular for the treatment and prophylaxis of atrial arrhythmias, for example atrial fibrillation or atrial flutter.