Systematic use of infrared imaging characterizes marks made on items and identifies the particular marking tool with better accuracy than use of visual imaging. The composition, which reduces the wear of sliding parts of a transmission element, comprises: an amide compound having one or two amide groups and forming a three-dimensional network structure; and a liquid base oil ingredient having a dynamic viscosity at 100\xb0 C. The circuit includes a circulation pump, a water overflow valve which can be set to a lower pressure than the feed pump, and a heating unit which is controlled by the first temperature sensor. The cover can also be deployed to treat vulnerable plaque. The or each trolley is provided with a clamping device which can be used to grip the inboard end of part of a multi-section streamer deployed over the stern end of the streamer deck, so facilitating the transfer of parts of streamers from one streamer station to another across the width of the streamer deck. The belief map includes belief values indicating the likelihood that respective pixels are representative of a particular material, such as flesh.