A welding bug comprising a welding torch for welding in a groove. A gangway extends from the frame’s front end for extending to another platform such as an aircraft doorway so that the gangway can be aligned therewith by manipulating the frame in the operating plane. Also provided by the invention are tissue cultures of the soybean variety 01046238 and the plants regenerated therefrom. A flow sensor, for sensing a measure related to a flow rate of a fluid flowing through the fluid channel, is positioned in one of the two or more fluid sub-passages. Moreover, in the gain region, an optical gain for the TE mode is configured to be larger than that for the TM mode, and, in the saturable absorption region, absorption saturation energy for the TM mode is configured to be smaller than absorption saturation energy for the TE mode.