A property of a target structure is measured based on intensity of an image of the target. , wherein the substituents have the values mentioned herein, are Procollagen C-Proteinase inhibitors and have utility in conditions mediated by PCP. When a distance to be focused is infinity, only the first lens group and the second lens group move for zooming. The network interface advantageously provides an isochronous request to the arbiter filter to thereby de-assert conflicting requests so that the network interface may effectively perform a time-sensitive isochronous data transfer. A latch on the base and a keeper provided by the handle interengage in the retracted position of the legs to releasably hold the legs in the retracted position.