A 600-year marine record associated with the dynamics of the eastern Penny Ice Cap (Baffin Island, Nunavut, Canada)

Two composite sedimentary sequences sampled in the ice-proximal (12CS) and ice-distal (02CS) areas of Coronation Fjord (Baffin Island, Nunavut, Canada) were investigated in order to reconstruct the effect of climate variability on 600 years of changes in sediment transfer from the eastern Penny Ice Cap (PIC). Detrital proxies, and physical and sedimentological analyses revealed that glacial meltwater discharges led to frequent rapidly deposited layers (RDLs) in ice-proximal settings. RDLs in ice-distal settings involved the sudden release of a large quantity of sediment-laden water during floods probably originating from adjacent fjords with large sandur deltas. Laminated sediments with ice-rafted debris throughout the Little Ice Age interval in the ice-proximal environment suggest that colder conditions promoted glacier growth, leading to successive episodes of turbid hyperpycnal meltwater plumes and iceberg calving in Coronation Fjord. Since 1850 ce, the accelerated Coronation retreat in response to modern warming has led to increased sedimentation rates, abrupt mineralogical and grain size proxy variations and more frequent RDLs. Similar trends between the detrital proxies of the ice-proximal core and Atlantic Multidecadal Oscillation record and Arctic surface air temperature suggest high connectivity between atmospheric and sea surface temperature variations and PIC dynamics over the last 600 years. -- Keywords : Baffin Island ; geochemistry ; glacier dynamics ; mineralogy ; Penny Ice Cap ; rapidly deposited layers ; sediment dynamics ; sedimentology

Late Pleistocene and Holocene transgression inferred from the sediments of the Gulf of San Jorge, central Patagonia, Argentina

This study presents the first detailed description of the upper sedimentary succession of the late Pleistocene and Holocene deposits in the Gulf of San Jorge (Patagonia) based on several hundred kilometers of high-resolution seismic (sparker) profiles and numerous sediment cores. High-resolution seismic stratigraphy confirms the existence of a paleo-fluvial network formed during sea-level lowstands and buried by central basin estuarine deposits during the last marine transgression. Analyses of lithostratigraphy and radiocarbon ages indicate the onset of subtidal sedimentation at ~14 cal ka bp. Before the onset of subtidal conditions, the first steps of marine incursion seem to have led to the development of lagoonal/wind–tidal flat environments, advocating for a sea-level stillstand. An abrupt increase in the log(Ti/Ca) ratio in a distinct multi-centimeter-thick layer and the identification of a wave-ravinement surface suggest rapid sea-level rise in the gulf prior to ~14 cal ka bp, consistent with Meltwater Pulse 1A. Overall, this study highlights the significant impact of sea-level rise on sedimentation in the gulf from the onset of marine incursions to the mid-Holocene, as well as the reduced contribution, as currently observed, of riverine inputs due to the progressive diminution and withdrawal of glacial drainage starting before the Holocene. -- Keywords : elemental geochemistry ; incised valleys ; MWP-1A ; Patagonia ; postglacial sea-level changes

Decadal changes in the mid-depth water mass dynamic of the Northeastern Atlantic margin (Bay of Biscay)

The lithium/magnesium (Li/Mg) molar ratios, radiocarbon measurements (?14C) and Nd-isotopic composition (eNd) of the aragonite skeleton of a branching cold-water coral (CWC) species Madrepora oculata collected alive in the Bay of Biscay at ~691 m water depth were investigated to reconstruct a robust record of the mid-depth water mass dynamics between 1950 and 1990 AD. Temperature estimates based on the skeletons Li/Mg molar ratios reveal small decadal changes of about 1 °C at thermocline depth synchronous to and of similar amplitude as surface temperature anomalies. ?14C measurements shows quasi-decadal oscillations of 15‰ around pre-bomb ?14C average value of -59±6‰ and post-bomb ?14C of -12±6‰, which most likely reflect decadal changes of water mass exchange across the thermocline. The coral eNd values remain in narrow ranges of -11.9 to -10.2, similar to the isotopic composition of East North Atlantic Central Water, but show highest values in the late 1950s, and early 1960s, 1970s, and 1980s. The punctuated changes of the coral Nd-isotopic composition may thus reflect periods of particular enhanced advection of temperate intermediate water (mid-depth Subpolar Gyre/Mediterranean Sea Water). Altogether, our robust multi-proxy record provides new evidence that Northern Hemisphere atmospheric variability (such as, North Atlantic Oscillation and East Atlantic pattern) drives changes not only in the thermocline but also in the mid-depth water-mass advection patterns in the Northeastern Atlantic margin. However, the interannual variability of our record remains to be tested

Dredging and canal gate technologies in Portus, the ancient harbour of Rome, reconstructed from event stratigraphy and multi-proxy sediment analysis

Ancient harbours are rich archives of human-environment interaction. However, dating harbour deposits and correlating their stratigraphy is a major challenge because of typically high sedimentation rates over short periods and possible curative dredging events. Portus, the maritime harbour of Rome at the height of the Roman Empire, was a port complex composed of basins and canals connecting the commercial harbour to Rome via the Tiber River. Sediment core CPS1 in the narrowest of these canals, Canale Traverso, is located centrally in what was the capital city's commercial hub and contains a continuous harbour depositional record with average sedimentation rates greater than 1 cm per year. Here we use piston coring, high-resolution core scanning and a multi-proxy sediment analysis including for the first time paleo- and rock-magnetism, and bulk and clay mineralogy in order to overcome the problems of dating harbour deposits and correlating their stratigraphy. The method allowed precise identification of major reworked events, including a dredged deposit and a hyperpycnal deposit, which improve the chronostratigraphy and water depth reconstruction, and sheds light on harbour technologies at the height of the Roman Empire. A debris layer with abundant ceramic fragments and rocks marks the decommissioning of Canale Traverso and provides a new chronostratigraphic marker at Portus. Multi-proxy riverine input signatures point to the possible use of canal gate technology for water flow management

South Atlantic intermediate water advances into the North-east Atlantic with reduced Atlantic meridional overturning circulation during the last glacial period

The Nd isotopic composition (epsilon Nd) of seawater and cold-water coral (CWC) samples from the Gulf of Cadiz and the Alboran Sea, at a depth of 280-827 m were investigated in order to constrain middepth water mass dynamics within the Gulf of Cadiz over the past 40 ka. epsilon Nd of glacial and Holocene CWC from the Alboran Sea and the northern Gulf of Cadiz reveals relatively constant values (-8.6 to -9.0 and -9.5 to -10.4, respectively). Such values are similar to those of the surrounding present-day middepth waters from the Mediterranean Outflow Water (MOW; epsilon Nd approximate to -9.4) and Mediterranean Sea Water (MSW; epsilon Nd approximate to -9.9). In contrast, glacial epsilon Nd values for CWC collected at thermocline depth (550-827 m) in the southern Gulf of Cadiz display a higher average value (-8.90.4) compared to the present-day value (-11.70.3). This implies a higher relative contribution of water masses of Mediterranean (MSW) or South Atlantic origin (East Antarctic Intermediate Water, EAAIW). Our study has produced the first evidence of significant radiogenic epsilon Nd values (approximate to -8) at 19, 23-24, and 27 ka, which are coeval with increasing iceberg discharges and a weakening of Atlantic Meridional Overturning Circulation (AMOC). Since MOW epsilon Nd values remained stable during the last glacial period, it is suggested that these radiogenic epsilon Nd values most likely reflect an enhanced northward propagation of glacial EAAIW into the eastern Atlantic Basin

Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Dynamique sédimentaire et paleoclimatique du Golfe du Mexique au cours du dernier cycle glaciaire

Les objectifs de cette thèse sont d’étudier la sédimentation dans des sous bassins privilégiés du Golfe du Mexique (Bassin de Pigmy et de La Salle) afin de reconstituer la variabilité des apports détritiques via le fleuve Mississippi au cours du dernier cycle climatique. Une approche intégrée couplant minéralogie, granulométrie, géochimie élémentaire et organique, dans un cadre chronostratigraphique précis, a permis de progresser dans la compréhension des relations entre les mécanismes climatiques de moyenne et haute latitude et l’hydrologie du domaine subtropical et de proposer des schémas d’interprétation du couplage océan-atmosphère. La minéralogie contrastée des zones en érosion drainées par le système fluviatile du bassin versant du Mississippi permet de contraindre les zones continentales qui vont successivement alimenter la sédimentation du Golfe du Mexique. Les modifications des sources détritiques ainsi mises en évidence au cours du dernier cycle climatique ont permis (1) de contraindre la localisation des zones de déstabilisation de la marge Laurentide et l’enchaînement des processus sédimentaires lors des décharges d’eau douce qui caractérisent la dernière déglaciation, (2) de mettre en évidence une modification du front de précipitations associée aux périodes de mégacrue du Mississippi lors des périodes interglaciaires et d’en déduire des informations sur le régime hydrologique et (3) de suggérer des schémas de transferts méridiens d’humidité contrastés lors des stades interglaciaires 1 et 5e, suggérant des configurations atmosphériques sensiblement différentes. La confrontation de ces résultats avec d’autres données paléoclimatiques a alors permis de proposer plusieurs modèles simples pour les interactions océan-atmosphère dans le Golfe du Mexique, basés sur les modifications des configurations atmosphériques (Jet Stream et ITCZ) et océaniques (extension de l’Atlantic Warm Pool) et confirme le rôle majeur de l’atmosphère comme vecteur de la variabilité climatique rapide.The objectives of this thesis are to study the sedimentary features of some basins of the Gulf of Mexico (Pigmy and La Salle basins) in order to reconstitute the variability of the detrital input via the Mississippi River during the last climatic cycle. An integrated approach coupling mineralogy, granulometry, and geochemistry (inorganic and organic), within a precise chronostratigraphic framework, allows to progress in the understanding of the relations between the mid- and high-latitude climatic mechanisms and the subtropical hydrology, as well as to propose synoptic models of the ocean-atmosphere coupling. The contrasting mineralogy of the zones drained by the catchment system of the Mississippi River watershed allows constraining the continental zones which will successively feed the sedimentation of the Gulf of Mexico. The modifications of the detrital sources revealed for the last climatic cycle enabled (1) to track down the localization of the zones of destabilization of the southern margin of the Laurentide Ice Sheet and the sequence of sedimentary processes during the freshwater discharges, which characterized the last deglaciation, (2) to highlight modifications of the precipitation front which were associated with episodes of large Mississippi River floods during interglacial times, and therefore, to deduce information on the hydrological regime, and (3) to suggest schematic models of meridian transfer of moisture contrasted during interglacial stages 1 and 5e, suggesting an appreciable difference in the atmospheric configurations. The confrontation of these results with other paleoclimatic records allowed to propose simple models of the atmosphere-ocean-continent interactions recorded in the Gulf of Mexico, which are based on the modifications of both the atmospheric configurations (Jet Stream and ITCZ) and oceanic (extension of Atlantic Warm Pool). These models confirm the major role of the atmosphere as a vector of rapid climatic variabilit

Decadal changes in the mid-depth water mass dynamic of the Northeastern Atlantic margin (Bay of Biscay)

Montero-Serrano, Jean-Carlos ...et al.-- 11 pages, 7 figues, 1 table, 1 appendixThe lithium/magnesium (Li/Mg) molar ratios, radiocarbon measurements (δ14C) and Nd-isotopic composition (εNd) of the aragonite skeleton of a branching cold-water coral (CWC) species Madrepora oculata collected alive in the Bay of Biscay at ~691m water depth were investigated to reconstruct a robust record of the mid-depth water mass dynamics between 1950 and 1990 AD. Temperature estimates based on the skeletons Li/Mg molar ratios reveal small decadal changes of about 1°C at thermocline depth synchronous to and of similar amplitude as surface temperature anomalies δ14C measurements shows quasi-decadal oscillations of 15%; around pre-bomb δ14C average value of -59±6%; and post-bomb δ14C of -12±6%;, which most likely reflect decadal changes of water mass exchange across the thermocline. The coral εNd values remain in narrow ranges of -11.9 to -10.2, similar to the isotopic composition of East North Atlantic Central Water, but show highest values in the late 1950s, and early 1960s, 1970s, and 1980s. The punctuated changes of the coral Nd-isotopic composition may thus reflect periods of particular enhanced advection of temperate intermediate water (mid-depth Subpolar Gyre/Mediterranean Sea Water). Altogether, our robust multi-proxy record provides new evidence that Northern Hemisphere atmospheric variability (such as, North Atlantic Oscillation and East Atlantic pattern) drives changes not only in the thermocline but also in the mid-depth water-mass advection patterns in the Northeastern Atlantic margin. However, the interannual variability of our record remains to be tested. © 2013 Elsevier B.V.This work was funded through the French Agence National de Recherche projet (NEWTON: ANR-BLANC06-1-139504), the French Centre National de la Recherche Scientifique (CNRS) and the Commisariat à l'Energie Atomique et aux Energies Alternatives (CEA). We also acknowledge Louise Bordier for her support with the ICP-MS analyses. Finally we acknowledge the support of ESF EuroDIVERSITY MiCROSYSTEMS, the EC FP6 IP HERMES (GOCE-CT-2005-511234-1) and EC FP7 IP HERMIONE (Grant agreement no. 226354) projects during which the present coral sample has been recovered. [...] Determinations of U–Th isotopic compositions and 230Th/U dates were supported by Taiwan ROC grants (NSC 101-2116-M-002-009 and NTU 102R7625) to C.-C.S.Peer Reviewe