The mass spectra of many 16-and 17-keto steroids contain ions [ -56]•+, the formation of which has been ascribed to cleavages of the bonds C-13/17 and C-14/15.1 These ions are often accompanied by ions

BSIs) in a tertiary hospital reveals how community-hospital dynamics, 2 influence local BSI rates, the trends of the B2 phylogroup and the 3 ABSTRACT 24Escherichia coli is overrepresented in all bloodstream infections (BSIs) series, mostly 25 associated with a few clonal lineages. Its population structure has been analyzed but the 26 dynamics remains to be fully understood. We analyze the dynamics of E. coli-BSIs in a sample 27 of 649 isolates, representing all 7165 E. coli BSI episodes recorded in a tertiary hospital (1996-28 2016) according to clonal identification (phylogenetic groups/subgroups, STc131 subclades), 29 antibiotic susceptibility (13 antibiotics), and virulence-associated genes (VAGs, 29 genes). 30Patient data were obtained from the laboratory system and clinical charts. The incidence of BSI-31 EC doubled from 1996 to 2016 (5.5 to 10.8 BSI episodes/1000 hospitalizations). Intertwined 32 waves of community-acquired (CA) and hospital-acquired isolates (HA) episodes of both B2 and 33 non-B2 phylogroups, occurred until B2 overtook non-B2 BSI episodes. ST131 contributed to 34 increasing the B2 rates, but only transiently altered the population structure. B2 isolates 35 predominates (53%), overrepresented by subgroups B2-I (STc131), B2-II, B2-IX, and B2-VI 36 (25%, 25%, 14%, and 9%). We observed a remarkable increase only for B2-I-STc131 (C1/C2 37 subclades), a decreasing trend for phylogroup D, and oscillations for other B2 subgroups 38 throughout the years. According to VAG patterns, B2 strains exhibit a population structure 39 compatible with the niche specialization theory. A reservoir of B2 and non-B2 strains 40 represented in human microbiota, flows from the community to the hospital and vice-versa, 41where they can either be selected or coexist. The increase of BSI is determined by waves of CA 42 that predate the amplification of HA episodes of both B2 and non-B2 phylogroups in various 43 time periods, influenced by FQR and microbiota composition. 44 45 (O16/O25b), clades (H41, H22, H30), and the H30 subclades C0 [H30, fluoroquinolone 129 susceptible (FQ S )], C1 [H30-R, fluoroquinolone resistant (FQ R )], C2 (H30Rx, FQ R +bla CTX-M-15 ), 130 and C1-M27 (H30-Rx, FQ R + bla CTX-M-27 ) (22, 23). STc131 isolates were further analyzed by 131 pulsed field gel electrophoresis (PFGE). The presence of 29 virulence-associated genes 132 (VAGs) was determined for all B2 isolates by PCR (2, 24). 133 Statistical analysis. To calculate statistical significance, the chi-squared test, a 2-sample t-test 134 for normally distributed variables, and Kendall's correlation were used, considering p-values 135 <0.05 to be statistically significant. 136 137

Crew sleep-wake patterns were investigated using the new technology of actigraphy. During a routine seven day coastal patrol in HMCS Saguenay, the devices were worn by 20 personnel; eight dayworkers, eight ‘rotating shift’ watchkeepers, and four senior crew. To assess the validity of actigraphic data the results were compared with subjective sleep reports. Analyses showed that the actigraphic estimates of sleep quantity exceeded the subjective estimates by about one hour for watchkeepers and senior crew. There was no difference between the two estimates for dayworkers. Reasons suggested for differences between actigraphic and subjective sleep quantity estimates are discussed. Further laboratory studies are required to determine threshold sleep values for the actigraph. Once these studies have been completed the actigraph will have great utility for helping to determine optimal work/rest/sleep regimes for operational environments.