S. 2004. Diel patterns in pelagic fish behaviour and distribution observed from a stationary, bottom-mounted, and upward-facing transducer. e ICES Journal of Marine Science, 61: 1100e1104.Diel variation in pelagic fish distribution influences hydroacoustic abundance estimates. To study and quantify diel patterns in behaviour and spatial distribution in pelagic fish without causing avoidance reactions or attraction to any floating equipment or vessel we used a bottom-mounted, upward-facing transducer. Light intensities were measured as skylight and underwater light (at 5-m depth). The study was performed in a coastal area in the Baltic Sea, late July to mid-August in 2001 and 2002. The results provided additional information on fish behaviour and distribution valuable for future survey planning and in the analyses of hydroacoustic data from regular surveys in this area. At night, the data on hydroacoustic backscattering (s A ) were less variable, the vertical distribution of fish was more even, with fewer fish in the deepest layer, and the percentage of single-echo detections was higher. The tilt angle of fish seemed to differ day and night, but trawling and target-strength distribution results taken together also implied a partial diel change in the fish assemblage in the midwater layers. The processes of formation and disintegration of schools happened rapidly and coincided with day and night transition periods.

Purpose of investigation:To compare the maternal and neonatal outcomes of preterm premature rupture of the membranes (PPROM) between two management strategies. Materials and Methods: This retrospective cohort study involved 153 pregnant women who presented with PPROM at a gestational age of 28+0 to 36+6 weeks to evaluate the effects of expectant management (EM; labor > 36 hours) and active management (AM; labor < 36 hours) on maternal and neonatal outcomes. The EM and AM groups were also compared independently of gestational age and after being divided into two subgroups: early PPROM (gestational age 28+0 to 33+6 weeks) and late PPROM (34+0 to 36+6 weeks). Results: There were no differences between the AM and EM groups in the rates of maternal infection or placental abruption, or in neonatal outcomes, including low Apgar scores, respiratory distress syndrome, or the need for continuous positive airway pressure (CPAP). In the early PPROM subgroup, arterial umbilical blood base excess levels were more negative in the AM group (p = 0.007). In the late PPROM subgroup, the change in systolic blood pressure between admission to the maternity care center and membrane rupture was greater in the AM group (p = 0.049). Conclusions: There were no clinically significant differences in the maternal and neonatal outcomes of PPROM between AM and EM.