"Self-intersections of immersions and Steenrod operations". Mark Grant (Durham) Abstract: In the late 1960's tom Dieck discovered operations in cobordism theory which lift Steenrod's operations in ordinary cohomology. Under Quillen's geometric interpretation of cobordism, these admit a simple interpretation in terms of proper maps of manifolds. Let f be a proper, generic immersion representing the cobordism class [f]. We will give a formula for the image of [f] under a Steenrod-tom Dieck operation of Z_2 type, involving the double-point immersion of f and the pushed-forward characteristic classes of the normal bundle, and discuss applications. This is joint work (in progress) with Peter Eccles.