Correction of the IRD Influence for Paleo‐Current Flow Speed Reconstructions in Hemipelagic Sediments

Reconstructions of past changes in deep-sea current intensities are needed to understand ocean-climate interactions in the past. The mean size of the sortable silt fraction (10 – 63 µm, ) is one of the most used proxies in this domain. However, in polar and subpolar environments under relatively low flow speed conditions, the presence of Ice-Rafted Detritus (IRD) may alter the record and thus bias the interpretation of paleo-current strength changes. In this paper, we examine the influence of IRD on the record of three sedimentary cores from the subpolar North Atlantic and the Antarctic margin. The influence of unsorted IRD on records is clearly established. To remove this IRD influence on grain-size distributions, we propose a new method based on End-Member Analysis approach, and for which a MATLAB script is made available. This method characterizes the grain-size distribution of the unsorted IRD input, allowing it to be isolated and discarded, and the current sensitive variability to be robustly identified. The method therefore allows the recalculation of a modified sediment grain-size distribution free of unsorted IRD influence and the construction of modified and sortable silt percentage (the % of the 10-63 μm in the total <63 μm fraction) records. The application of the method to the three studied cores shows that (i) the unsorted IRD component is correctly removed from the grain-size signal and (ii) the new record is consistent with the XRF-based ln(Zr/Rb) grain-size proxy. This article is protected by copyright. All rights reserved. Key Points Evidence for unsorted IRD influence on records of hemipelagic sediments in subpolar environments New method proposed to provide grain-size distributions free of unsorted IRD influence Allows to define a paleo-current strength proxy free of unsorted IRD contributio

Hyperpycnal-fed turbidite lobe architecture and recent sedimentary processes: A case study from the Al Batha turbidite system, Oman margin

J. Bourget, S. Zaragosi, T. Mulder, J.-L. Schneider, T. Garlan, A. Van Toer, V. Mas, N. Ellouz-Zimmerman

Cost-effectiveness of laparoscopic ileocaecal resection versus infliximab treatment of terminal ileitis in Crohn's disease: The LIR!C Trial

Objective Evaluate the cost-effectiveness of laparoscopic ileocaecal resection compared with infliximab in patients with ileocaecal Crohn's disease failing conventional therapy. Design A multicentre randomised controlled trial was performed in 29 centres in The Netherlands and the UK. Adult patients with Crohn's disease of the terminal ileum who failed >3 months of conventional immunomodulators or steroids without signs of critical strictures were randomised to laparoscopic ileocaecal resection or infliximab. Outcome measures included quality-adjusted life-years (QALYs) based on the EuroQol (EQ) 5D-3L Questionnaire and the Inflammatory Bowel Disease Questionnaire (IBDQ). Costs were measured from a societal perspective. Analyses were performed according to the intention-to-treat principle. Missing cost and effect data were imputed using multiple imputation. Cost-effectiveness planes and cost-effectiveness acceptability curves were estimated to show uncertainty. Results In total, 143 patients were randomised. Mean Crohn's disease total direct healthcare costs per patient at 1 year were lower in the resection group compared with the infliximab group (mean difference €-8931; 95% CI €-12 087 to €-5097). Total societal costs in the resection group were lower than in the infliximab group, however not statistically significant (mean difference €-5729, 95% CI €-10 606 to €172). The probability of resection being cost-effective compared with infliximab was 0.96 at a willingness to pay (WTP) of €0 per QALY gained and per point improvement in IBDQ Score. This probability increased to 0.98 at a WTP of €20 000/QALY gained and 0.99 at a WTP of €500/point of improvement in IBDQ Score. Conclusion Laparoscopic ileocaecal resection is a cost-effective treatment option compared with infliximab. Clinical trial registration number Dutch Trial Registry NTR1150; EudraCT number 2007-005042-20 (closed on 14 October 2015)