The Lambeth Conventions are guidelines intended to be of practical value in the investigation of arrhythmias induced by ischaemia, infarction, and reperfusion. They cover the design and execution of experiments and the definition, classification, quantification, and analysis of arrhythmias. Investigators are encouraged to adopt the conventions in the hope that this will improve uniformity and interlaboratory comparisons.

Some of the longest and most comprehensive marine ecosystem monitoring programs were established in the Gulf of Alaska following the environmental disaster of the Exxon Valdez oil spill over 30 years ago. These monitoring programs have been successful in assessing recovery from oil spill impacts, and their continuation decades later has now provided an unparalleled assessment of ecosystem responses to another newly emerging global threat, marine heatwaves. The 2014–2016 northeast Pacific marine heatwave (PMH) in the Gulf of Alaska was the longest lasting heatwave globally over the past decade, with some cooling, but also continued warm conditions through 2019. Our analysis of 187 time series from primary production to commercial fisheries and nearshore intertidal to offshore oceanic domains demonstrate abrupt changes across trophic levels, with many responses persisting up to at least 5 years after the onset of the heatwave. Furthermore, our suite of metrics showed novel community-level groupings relative to at least a decade prior to the heatwave. Given anticipated increases in marine heatwaves under current climate projections, it remains uncertain when or if the Gulf of Alaska ecosystem will return to a pre-PMH state.

While recent work demonstrates that glacial meltwater provides a substantial and relatively labile flux of the micronutrient iron to oceans, the role of high-latitude estuary environments as a potential sink of glacial iron is unknown. Here we present the first quantitative description of iron removal in a meltwater-dominated estuary. We find that 85% of "dissolved" Fe is removed in the low-salinity region of the estuary along with 41% of "total dissolvable" iron associated with glacial flour. We couple these findings with hydrologic and geochemical data from Gulf of Alaska (GoA) glacierized catchments to calculate meltwater-derived fluxes of size and species partitioned Fe to the GoA. Iron flux data indicate that labile iron in the glacial flour and associated Fe minerals dominate the meltwater contribution to the Fe budget of the GoA. As such, GoA nutrient cycles and related ecosystems could be strongly influenced by continued ice loss in its watershed.

Abstract:We developed new perspectives to identify important questions and to propose approaches for future research on marine food web lipids. They were related to (i) structure and function of lipids, (ii) lipid changes during critical life phases, (iii) trophic marker lipids, and (iv) potential impact of climate change. The first addresses the role of lipids in membranes, storage lipids, and buoyancy with the following key question: How are the properties of membranes and deposits affected by the various types of lipids? The second deals with the importance of various types of lipids during reproduction, development, and resting phases and addresses the role of the different storage lipids during growth and dormancy. The third relates to trophic marker lipids, which are an important tool to follow lipid and energy transfer through the food web. The central question is how can fatty acids be used to identify and quantify food web relationships? With the fourth, hypotheses are presented on effects of global warming, which may result in the reduction or change in abundance of large, lipid-rich copepods in polar oceans, thereby strongly affecting higher trophic levels. The key question is how will lipid dynamics respond to changes in ocean climate at high latitudes? Kattner et al. 1639Résumé : Une nouvelle approche a été développée afin d'identifier les questions importantes relatives aux lipides dans les réseaux alimentaires marins et pour suggérer de nouvelles perspectives pour les recherches futures. Celles-ci concernent (i) la structure et la fonction des lipides, (ii) les changements lipidiques durant les phases critiques du cycle biologique, (iii) le rôle des lipides comme marqueurs trophiques et (iv) l'impact potentiel du changement climatique. Le premier point touche le rôle des lipides dans les membranes, les lipides de réserve et la flottabilité et la question essentielle est de savoir comment les propriétés des membranes et des réserves sont affectées par les divers types de lipides? Le second point traite de l'importance des lipides durant les phases de reproduction, de développement et de repos, ainsi que du rôle des différents lipides de réserve durant la croissance et la dormance.

During mid-May-early June 1997 observations of hydrography, phytoplankton and nitrate concentrations, and abundance and stage distribution of Calanus finmarchicus populations were made in the Labrador Sea and south of Greenland. Egg production rates were also measured for isolated C. finmarchicus females. Surface nitrate and integrated phytoplankton concentrations indicated that, in the deep water, the phytoplankton bloom had ended in the north and east, was in progress in the north central Labrador Sea and near the basin margins, and had not yet become established in an area stretching from the central Labrador Sea to the south of Greenland. C. finmarchicus egg production rates and stage distributions at stations in the 3 areas designated as early, mid-and late/post-bloom zones, suggested that development rates of the overwintered GO generation into mature adults (females and males) were probably low before the bloom, but accelerated during its development. Individual and area1 rates of egg production were highest in the early bloom zone, whereas nauplii were more abundant in the bloom and late/post-bloom zones. Differences in naupliar abundance may have been related to food limitation, or predation. Following development through to the young copepodite stages (CI-111), which were most abundant in the late/post-bloom zone, morality rates were apparently lower and growth rates less dependent on high phytoplankton concentrations and perhaps more dependent on temperature. In the Labrador Sea, where the annual growth season is relatively short and C. finmarchicus produces only 1 generation per year, the timing of the spring bloom may have a significant impact on recruitment of the new year's generation. In areas where the bloom is early and intense, maturation of the overwintered adults will be rapid and egg-laying will occur when phytoplankton concentrations are high. Subsequent survival success of eggs through to later stages will also probably be relatively high and individuals from the new year's generation will have ample time to reach stages capable of overwintering. By contrast, if the bloom is late or of low intensity, adult maturation wdl be delayed and egg-laying may occur when phytoplankton concentrations are low. Under these condtions relatively few eggs may survive and individuals that do survive will have a shorter period in which to attain stages which can overwinter.