The present invention encompasses polymer compositions comprising aliphatic polycarbonate chains containing sites of olefinic unsaturation. This invention also relates to the transformed cells and seeds, and to the fertile plants grown from the transformed cells and to their pollen. The optical fibre has a core region that includes three segments and an inner cladding segment, each having a maximum refractive index percent difference, \u0394deltai %, i=0-3, the subscript i referring to a particular refractive index, the core segments being selected such that \u0394delta0%>\u0394delta2%>\u0394delta1%\u22670 and \u0394delta2%>\u0394delta3%\u22670. The first and second laminate barrier layers are sealed together to form a fluid-tight enclosure, wherein the product material substantially fills the enclosure and the modified dome shape is resiliently sustainable. Different embodiments of end connectors and side connectors in divisible or indivisible unions are provided for end-to-end and side-to-end anastomoses of various hollow structures. The system includes a circumferential ablation member with an ablation element and also includes a delivery assembly for delivering the ablation member to the location.