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Listeria monocytogenes is a ubiquitous, saprophytic, Gram-positive bacterium and occasional food-borne pathogen, often associated with ready-to-eat meat products. Because of the increased consumer interest in organic, all natural, and free range poultry products, it is important to understand L. monocytogenes in the context of such systems. Pasture-reared poultry were surveyed over the course of two 8-wk rearing periods. Cecal, soil, and grass samples were collected for Listeria isolation and characterization. Seven of 399 cecal samples (or 1.75%) were Listeria-positive. All positive cecal samples were obtained from broilers sampled at 2 wk of age. Grass and soil samples were collected from the pasture both before and after introduction of the poultry. Environmental samples collected after introduction of poultry were significantly more likely to contain Listeria (P < 0.001). The results of analytical profile index Listeria, sigB allelic typing, and hlyA PCR tests found that both L. monocytogenes and L. innocua, including hemolytic L. innocua, were recovered from the cecal and environmental (grass/soil) samples. The sigB allelic typing also revealed that (1) positive samples could be composed of 2 or more allelic types; (2) allelic types found in cecal samples could also be found in the environment; and (3) allelic types could persist through the 2 rearing periods. Our data indicate that both pasture-reared poultry and their environment can be contaminated with L. monocytogenes and hemolytic L. innocua.

Summary form only given. As device scaling approaches ever smaller regimes, multiple layer device fabrication is necessary to increase chip integration up to and beyond the gigascale regime. This paper presents multiple layer SOI (MLSOI) islands fabricated using Si SEG and ELO. The MLSOI fabrication process used was an extension of the single layer SOI island process (Neudeck et al, 1997). The first SOI layer was created by forming oxide wells via oxidation, RIE oxide etch, and re-oxidation. Adjacent to the wells, a SEG/ELO seed window is opened. SEG/ELO was grown from the seed window and laterally over the field oxide until the recessed oxide wells were filled. Excess SEG/ELO over the recess wells was removed by CMP down to the field oxide level, isolating Si in the recessed wells from the seed and thus creating SOI active device islands. The second SOI layer was similarly fabricated, but a PECVD oxide was used to create the next recessed well layer. The PECVD oxide layer wells were created by timed RIE or wet etching, but an intermediate etch stop layer can be incorporated by using LPCVD Si/sub 3/N/sub 4/ prior to oxide PECVD. By repeating the fabrication process presented, additional SOI layers can be fabricated. The potential benefits of MLSOI designs are immense. Packing densities can be dramatically increased. Different device processes can be incorporated into the different MLSOI layers, e.g. making pMOSFETs on one layer and nMOSFETs on another. By designing two SRAM cells (using eight nMOSFETs and four pMOSFETs) in three Si layers with pMOSFETs in the middle layer between nMOSFET layers, area saved is about 3/spl times/.