Abstract: A composite structure having a thickness substantially less than its width such as a sheet is prepared which includes a substantially water-insoluble particulate or fibrous support having a surface energy of at least about 30 dynes per cm to which nitrogen-fixing filamentous blue-green algae heterocyst cells are attached. the support does not have a deleterious effect on the attached algae and is preferably cellulosic or a polyoletin such a polypropylene. The structure may contain a first and second layer and have a plurality of raised, three-dimensional shapes over at least a portion of at least one surface. Preparing the composite structure includes contacting the support with blue-green algae to permit the algae to attach to the support by means of heterocyst cells. The attach cells in a nitrogen deficient environment, fix nitrogen at a rate substantially greater than unattached cells, and have agricultural applications.

Abstract: A siloxane which contains at least one benzotriazolyl/tetraalkylpiperidyl group, which siloxane can be represented by the general formula, S-Z, in which S represents a siloxane moiety and Z represents a pendant benzotriazolyl/tetraalkylpiperidyl group attached by means of a divalent connecting group to a silicon atom.The compounds are useful as additives for the preparation of surface-segregatable, melt-extrudable thermoplastic compositions. The compositions, in turn, are useful for the preparation of fibers and films by melt extrusion, which fibers and films have enhanced stability to degradation by actinic radiation.