A method for producing metallic iron nodules by assembling a shielding entry system to introduce coarse carbonaceous material greater than 6 mesh in to the furnace atmosphere at location where the temperature of the furnace atmosphere adjacent at least partially reduced reducible iron bearing material is between about 2200 and 2650\xb0 F. The method automatically determines andor incorporates prevalence-based computer analysis based on an estimated likelihood of a pathological state, e. The predetermined pattern includes a plurality of section periods for which the duty ratio maintains mutually different values for a predetermined period. The system includes an issue selection database having a listing of issues available for trading where each issue is ranked based on a trading parameter. The fixture is particularly useful for mounting HID lamps within illuminated signs. Another embodiment of the apparatus includes a lumenal body defining at least one infusion port for infusing the therapeutic agent into the body lumen, and a filtration element which is distal of the at least one infusion port and adapted to deliver a reaction agent which may react with the therapeutic agent in the body lumen.