Nitrate supply and uptake in the Atlantic Arctic sea ice zone: seasonal cycle, mechanisms and drivers

Nutrient supply to the surface ocean is a key factor regulating primary production in the Arctic Ocean under current conditions and with ongoing warming and sea ice losses. Here we present seasonal nitrate concentration and hydrographic data from two oceanographic moorings on the northern Barents shelf between autumn 2017 and summer 2018. The eastern mooring was sea ice-covered to varying degrees during autumn, winter and spring, and was characterized by more Arctic-like oceanographic conditions, while the western mooring was ice-free year-round and showed a greater influence of Atlantic water masses. The seasonal cycle in nitrate dynamics was similar under ice-influenced and ice-free conditions, with biological nitrate uptake beginning near-synchronously in early May, but important differences between the moorings were observed. Nitrate supply to the surface ocean preceding and during the period of rapid drawdown was greater at the ice-free more Atlantic-like western mooring, and nitrate drawdown occurred more slowly over a longer period of time. This suggests that with ongoing sea ice losses and Atlantification, the expected shift from more Arctic-like ice-influenced conditions to more Atlantic-like ice-free conditions is likely to increase nutrient availability and the duration of seasonal drawdown in this Arctic shelf region. The extent to which this increased nutrient availability and longer drawdown periods will lead to increases in total nitrate uptake, and support the projected increases in primary production, will depend on changes in upper ocean stratification and their effect on light availability to phytoplankton as changes in climate and the physical environment proceed. This article is part of the theme issue 'The changing Arctic Ocean: consequences for biological communities, biogeochemical processes and ecosystem functioning'

Transports and pathways of overflow water in the Rockall Trough

Water mass analysis reveals a persistent core of deep overflow water within the Rockall Trough which hugs the northern and western boundaries of the basin. Mean speeds within this overflow are 10–15 cm s−1 giving a transport time from the Wyville Thomson Ridge to the central basin of < 50 days. Analysis of the 40-year Extended Ellett Line record shows proportions of Norwegian Sea Deep Water associated with the deep core exceed 15% around one quarter of the time. We present the first transport estimates for overflow water in the Rockall Trough. This flux is for overflow water modified by mixing with a density greater than 27.65 kg m−3. Mean values calculated both from a newly deployed mooring array (OSNAP project) and indirectly from the Extended Ellett Line time-series are −0.3 ± 0.04 Sv. Although the flux is highly variable there is no long term trend. As some overflow appears to exit into the Iceland Basin via channels between the northern banks, we suggest that the volume transport will likely increase as the flow pathway is traced back around the boundary of the Rockall Trough towards the Wyville Thomson Ridge

Working to improve the management of sarcoma patients across Europe: a policy checklist

Background: The Sarcoma Policy Checklist was created by a multidisciplinary expert group to provide policymakers with priority areas to improve care for sarcoma patients. Main body: This paper draws on this research, by looking more closely at how France, Germany, Italy, Spain, Sweden and the United Kingdom are addressing each of these priority areas. It aims to highlight key gaps in research, policy and practice, as well as ongoing initiatives that may impact the future care of sarcoma patients in different European countries. A pragmatic review of the published and web-based literature was undertaken. Telephone interviews were conducted in each country with clinical and patient experts to substantiate findings. Research findings were discussed within the expert group and developed into five core policy recommendations. The five identified priority areas were: the development of designated and accredited centres of reference; more professional training; multidisciplinary care; greater incentives for research and innovation; and more rapid access to effective treatments. Most of the countries studied have ongoing initiatives addressing many of these priorities; however, many are in early stages of development, or require additional funding and resources. Conclusion: Gaps in access to quality care are particularly concerning in many of Europe’s lower-resourced countries. Equitable access to information, clinical trials, innovative treatments and quality specialist care should be available to all sarcoma patients. Achieving this across Europe will require close collaboration between all stakeholders at both the national and European level

Consolidation of Atlantic EGO Network Activities Report

Report on the network consolidation activities including the reports on the different meetings and personal exchange

Eastern boundaries survey

Report on glider surveys in eastern boundary regions, key regions for the Atlantic fishery and connected with the WP4. Survey, sampling and data delivery in these regions is investigated and reported in here

Interplay Between Membrane Permeability and Enzymatic Barrier Leads to Antibiotic-Dependent Resistance in Klebsiella Pneumoniae

The interplay between membrane permeability alterations and the enzymatic barrier contributes to Klebsiella pneumoniae multidrug resistance. We assessed the specific effect of the efflux levels of the main efflux pumps (AcrAB and OqxAB), alone and associated with the loss of the main porins (OmpK35 and OMPK36), on the activity of various antibiotics by constructing a set of K. pneumoniae isogenic strains, including strains with plasmid-mediated β-lactamases (DHA-1, CTX-M-15, and OXA-48). The two pumps contributed to intrinsic chloramphenicol resistance and AcrAB to that of nalidixic acid and cefoxitin, whereas they had no impact on the activity of the other 11 antibiotics tested. We confirmed the expulsion of these three antibiotics by the two overproduced pumps and that of tigecycline by overproduced AcrAB, and showed that overproduced AcrAB also expelled ertapenem, piperacillin, ceftolozane, and ceftazidime. The sole loss of porins did not significantly affect the activity of the tested antibiotics, except ertapenem. The effect of efflux increases and porin loss on β-lactam activity was the highest in plasmid-mediated β-lactamase-producing strains. Thus, DHA-1-producing strains became non-susceptible (NS) to (i) ertapenem when there was an increase in efflux or porin loss, (ii) imipenem and ceftazidime+avibactam when the two mechanisms were associated, and (iii) temocillin when AcrAB was overproduced. The CTX-M-15-producing strains became NS to (i) ertapenem when there was no porin, (ii) ceftolozane+tazobactam when there was either overproduced OqxAB or porin loss, and (iii) temocillin when AcrAB was overproduced. OXA-48-producing strains known to be NS to temocillin were also NS to ceftolozane and they became NS to imipenem when the two pumps were overproduced or there was porin loss. Overall, this study shows that the balance between influx and efflux differentially modulates the activity of the tested antibiotics, an important point for evaluating the activity of future antibiotics or new combinations

North Atlantic current and European slope current circulation in the Rockall Trough observed using moorings and gliders

The Rockall Trough (RT) accommodates the warmest and saltiest branch of the North Atlantic Current, which delivers water from the Gulf Stream into the marine environment around western Europe. In addition, the European Slope Current (ESC) carries warm water northward along the eastern boundary of the RT, and exchange between the ESC and the continental shelf is a dominant factor in determining the oceanographic conditions around the British Isles. However, the picture of the mean circulation and variability in the RT is still emerging, with a continuous observational campaign still in its relative infancy. The ESC, in particular, is poorly constrained by ship-based, mooring, and satellite observations. In this paper, we examine the RT circulation and volume transport using a temporally extended and spatially expanded observing network. Six years of continuous mooring occupation reveal that a large-amplitude, basin-scale freshening event, previously detected south of Iceland around 2015, impacted the RT around 2017. Geostrophic transport was greatly reduced during this period, driven by a concurrent subsurface temperature increase at the western boundary. The circulation regained strength during the latter part of the record. We gathered 110 glider transects over 22 months which capture the ESC velocity field in unprecedented detail. The data are sufficient to characterize both the mean state and the emergent seasonal variability of the ESC, and reveal the year-round presence of a southward countercurrent at depth. Variability in the strength and structure of this previously unstudied feature modulates net northward transport in the eastern boundary current system