2 °C min−1), to http://www.selleckchem.com/products/dinaciclib-sch727965.html (i) progressively lower sub-zero temperatures (−12.5 to −19.5 °C) below the DTemp for 8 h, before re-warming to +4 °C at 0.2 °C min−1, and (ii) progressively longer periods (10–48 h) at the DTemp, before re-warming to +4 °C at 0.2 °C min−1. Soil temperature data available from previous seasons at Signy Island and Anchorage Island (67oS
68oW) were used as a basis to establish two thermoperiods; one that E. murphyi currently experiences in summer on Signy Island, and one that might be experienced in summer on Anchorage Island. This was undertaken to assess the ability of E. murphyi larvae to survive at a more extreme, higher latitude, location. Using these models, an alcohol bath was programmed to cycle between +6 and −1 °C, and between +4 and −3 °C, representing Signy and Anchorage Islands respectively,
over a 24 h period ( Fig. 1). Larvae were transferred to each thermoperiod (beginning at 4 °C). Three replicates of 10 individuals were removed at two points in the cycle (−1 and 6 °C [Signy Island model] and −3 and 4 °C [Anchorage Island model]) each day for 3 days during each thermoperiodic cycle and directly transferred to the DTemp for 8 h, before being re-warmed to +4 °C at 0.2 °C min−1. To determine the effect of RCH on the SCP, juvenile and mature larvae were cooled from +4 to −30 °C at either 0.2 °C min−1 (RCH treatment) or 1 °C min−1 (mature larvae only). Controls were directly transferred to the DTemp. Juvenile and mature larvae (8 and 24 individuals) were placed in contact with a thermocouple, within Beem capsules, in glass BMN 673 mw test tubes plugged with sponge, inside an alcohol bath, prior to each cooling regime. SCPs, defined as the temperature at the
onset of the freezing exotherm, were identified using an eight channel datalogger interfaced to a computer and recorded using PicoLog Recorder Software (Pico Technology Limited, UK) (cf. Hawes et al., 2006). The time at which all mature larvae froze at −7 °C, having been cooled at 1 °C min−1 from +4 °C, was calculated as 4 min using PicoLog Recorder Software (Pico Technology Limited, UK). Three groups of 10 mature larvae were subsequently cooled from +4 to −7 °C at 1 °C min−1, held for 4 min or 1 h 4 min, and transferred to the DTemp for 8 h, before being re-warmed Tyrosine-protein kinase BLK to +4 °C at 0.2 °C min−1. Survival was assessed 24 and 72 h after each treatment. The Kolmogorov–Smirnov test was used to confirm that all percentage survival and SCP data were normally distributed. The data were subsequently analyzed using analysis of variance (ANOVA) and Tukey’s multiple range test. The mean survival of both juvenile and mature larvae decreased significantly following exposure to progressively lower sub-zero temperatures for 8 h (Fig. 2; P < 0.05 Tukey’s multiple range test), declining from more than 80% at −9 °C to 0% at −14 °C.