Efficient compressed database of equilibrated configurations of ring-linear polymer blends for MD simulations.

To effectively archive configuration data during molecular dynamics (MD) simulations of polymer systems, we present an efficient compression method with good numerical accuracy that preserves the topology of ring-linear polymer blends. To compress the fraction of floating-point data, we used the Jointed Hierarchical Precision Compression Number - Data Format (JHPCN-DF) method to apply zero padding for the tailing fraction bits, which did not affect the numerical accuracy, then compressed the data with Huffman coding. We also provided a dataset of well-equilibrated configurations of MD simulations for ring-linear polymer blends with various lengths of linear and ring polymers, including ring complexes composed of multiple rings such as polycatenane. We executed 109 MD steps to obtain 150 equilibrated configurations. The combination of JHPCN-DF and SZ compression achieved the best compression ratio for all cases. Therefore, the proposed method enables efficient archiving of MD trajectories. Moreover, the publicly available dataset of ring-linear polymer blends can be employed for studies of mathematical methods, including topology analysis and data compression, as well as MD simulations.

Henhouse feeding style and Salmonella Enteritidis contamination in unvaccinated flocks of egg farms, April 1994-March 2001.

From April 1994 to March 2001, monitoring tests (surveillance) for contamination of Salmonella Enteritidis (SE) at commercial egg farms and farm traceback inspections for cases of SE foodborne illness were carried out in the Himeji Livestock Hygiene Service Center jurisdiction of Hyogo Prefecture, Japan. SE vaccination was not performed before the outbreak of SE-associated foodborne illness, and SE contamination of a farm was recognized. In the surveillance, the year average percentages of identified SE-positive farms were 6.1% in farms with floor feeding in an open-type henhouse (F-OH) and 12.7% in farms with cage feeding in a windowless-type henhouse (C-WH), but 0% in farms with only cage feeding in an open-type henhouse (C-OH). The highest identified proportion of SE-positive farms among all styles of farms was found (4.3%) in April 1997-March 1999. Farm traceback inspections were performed in 2 of 7 farms feeding by F-OH and in 5 of 9 farms feeding by C-WH in this period. Easier contamination with SE was found for C-WH or F-OH than for C-OH. Ninety percent of the birds (3,632,000 birds at 70 farms) are fed at these easier contamination farms by C-WH (89% of birds in 13% of farms) or F-OH (1% of birds at 10% of farms). Integrated sanitary requirements and SE vaccinations are especially necessary on farms feeding by F-OH or C-WH. Since 1999, these countermeasures have been performed, and SE foodborne illnesses and affected patients in Hyogo Prefecture have gradually decreased.