Compounds of formula as well as pharmaceutically acceptable salts and esters thereof wherein the residues have the significance given in claim 1 and which can be used in the form of pharmaceutical compositions. In order for the receiver to have a high dynamic range, the adjustable impedance element is a PIN diode and the control means comprise separating means for separating the direct voltage component from the output voltage of the transimpedance amplifier, and means for adjusting the voltage over the PIN diode directly on the basis of the separated direct voltage component. For a given cooking process with fixed times for the supply of steam, on the basis of the moisture sensor evaluation during the measuring phase, the end of cooking is determined. A retainer provided on the cover engages the shelf to prevent the cover from moving forward or backward. In another described implementation, a watermarking system begins encoding of a watermark at a variable position after the beginning of a clip. The first helical threading defines a first volume between adjacent thread turns along the first length, and the second helical threading defines a second volume between adjacent thread turns along the second length, with the first volume being different from the second volume.