Abstract: Described herein are nucleic acid detection compositions and systems comprising an internal nuclease chain reaction (NCR) for signal amplification and methods of using these NCR-containing compositions and systems.

Abstract: Gravel packing a wellbore can include simultaneously conveying separate gravel slurry delivery and production strings into the wellbore, flowing a gravel slurry through the gravel slurry delivery string and into an annulus about the production string, and producing fluid from the wellbore via the production string. A gravel packing system can include the gravel slurry delivery and production strings positioned laterally adjacent each other in a wellbore, and the gravel slurry delivery string being in direct fluid communication with one passage in a packer, and the production string being in direct fluid communication with another passage in the packer. Another gravel packing method can include flowing a gravel slurry through a gravel slurry delivery string and into an annulus about a production string, producing fluid from the wellbore via the production string, and these steps being performed without manipulation of either of the strings in the wellbore.

Abstract: A high impact polyvinyl halide composition containing a polyvinyl halide polymer, a high rubber content copolymer of acrylonitrile, bitadiene and styrene, a copolymer of .alpha. methyl styrene and acrylonitrile, and a copolymer of ethylene and vinyl acetate.