12 research outputs found

    Sedimentary record of V, U, Mo and Mn in the Pierre-Blanche lagoon (Southern France). Evidence for a major anoxia event during the Roman period

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    International audienceThe distribution of redox-sensitive elements (V, U, Mo, Mn) was studied in a sedimentary archive of the Pierre-Blanche lagoon encompassing 3500 years of sedimentation. Between 240 and 255 cm (i.e. between 0 and 350 cal. ad) in the core, there was a dark layer with no mollusc shells. Enrichments of V, U and Mo and depletion of Mn were observed in this layer compared with overlying and underlying sediments. This was attributed to the occurrence of anoxia in bottom water or at the sediment/water interface during the Roman period. This episode was concomitant with the formation of a sandy barrier, which now isolates the lagoon from the sea. Our results suggest that the isolation of the lagoon, which was deeper in the period concerned than at present, favoured stagnation of the water. Combined with the excess nutrient inputs because of human activities in Lattara harbour, stagnation may have caused anoxia in bottom water at least in some parts of the Palavasian lagoon system. Bottom conditions nevertheless remained sufficiently reducing for the accumulation of U and Mo to persist until around 800 cal. ad. Although the lagoon has been hyper-eutrophic since at least the middle of the 20th century and although anoxia occurs frequently in summer, redox proxies show no evidence for their occurrence. The shallow water and associated resuspension and reoxidation events explain the lack of V, Mo and U enrichment in recent sediments

    A 10,000-year record of trace metal and metalloid (Cu, Hg, Sb, Pb) deposition in a western Alpine lake (Lake Robert, France): Deciphering local and regional mining contamination

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    International audienceConcentrations of trace metals and metalloids (Cu, Hg, Sb, Pb), major elements, stable Pb and C isotoperatios, total organic carbon (TOC), C/N atomic ratios, were analyzed in two sediment cores encompassing10,000 years of sedimentation sampled in Lake Robert (French Alps).The results showed that the establishment of a soil cover and vegetation during the Holocene climaticoptimum increased Cu and Hg deposition in sediments. Results also enabled reconstruction of the historyand local vs regional origins of pollution. During the Bronze Age (1800e1000 BC), Cu mining activitiesincreased Hg and Sb accumulation rates (AR) by a factor of 7 (Hg) and 9 (Sb) compared to pre-Bronze Agevalues. The rise in Hg AR was equivalent to that of the industrial era highlighting a major local Hg pointsource not recorded in regional archives. During the Iron Age, Pb pollution was attributed to Sicilian oreswhereas during the Roman Empire Pb pollution had the isotopic signature of Spanish Pb ores. During theMedieval period (ca. AD 1200), Pb and Hg pollution was due to the exploitation of the local AgePb mines.Finally, during the industrial era, metal accumulations rates were 90 (Pb), 5 (Hg) and 20 (Sb) times higherthan those in the pre-Bronze Age. The isotopic composition of Pb reflected mixed sources includingindustrial Pb and gasoline Pb. Synchronously, the increase in Sb and Hg pollution is attributed to globaland regional atmospheric pollution

    Late Holocene volcanic and anthropogenic mercury deposition in the western Central Andes (Lake Chungará, Chile)

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    International audienceVolcanism is one of the major natural processes emitting mercury (Hg) to the atmosphere, representing a significant component of the global Hg budget. The importance of volcanic eruptions for local-scale Hg deposition was investigated using analyses of Hg, inorganic elemental tracers, and organic biomarkers in a sediment sequence from Lake Chungará (4520 m a.s.l.). Environmental change and Hg deposition in the immediate vicinity of the Parinacota volcano were reconstructed over the last 2700 years, encompassing the pre-anthropogenic and anthropogenic periods. Twenty eruptions delivering large amounts of Hg (1 to 457 μg Hg m−2 yr−1 deposited at the timescale of the event) were locally recorded. Peaks of Hg concentration recorded after most of the eruptions were attributed to a decrease in sedimentation rate together with the rapid re-oxidation of gaseous elemental Hg and deposition with fine particles and incorporation into lake primary producers. Over the study period, the contribution of volcanic emissions has been estimated as 32% of the total Hg input to the lake. Sharp depletions in primary production occurred at each eruption, likely resulting from massive volcaniclastic inputs and changes in the lake-water physico-chemistry. Excluding the volcanic deposition periods, Hg accumulation rates rose from natural background values (1.9 ± 0.5 μg m−2 yr−1) by a factor of 2.3 during the pre-colonial mining period (1400–900 yr cal. BP), and by a factor of 6 and 7.6, respectively, during the Hispanic colonial epoch (400–150 yr cal. BP) and the industrial era (~140 yr cal. BP to present). Altogether, the dataset indicates that lake primary production has been the main, but not limiting, carrier for Hg to the sediment. Volcanic activity and climate change are only secondary drivers of local Hg deposition relative to the magnitude of regional and global anthropogenic emissions

    Usefulness of a personalized algorithm-based discharge checklist in patients hospitalized for acute heart failure

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    Aims The aim of this study is to evaluate the usefulness of a personalized discharge checklist (PCL) based on simple baseline characteristics on mortality, readmission for heart failure (HF), and quality of care in patients hospitalized for acute HF. Methods and results We designed an algorithm to generate PCL, based on 2016 HF European Society of Cardiology Guidelines and the screening of common comorbidities in elderly HF patients. We prospectively included 139 patients hospitalized for HF from May 2018 to October 2018. A PCL was fulfilled for each patient at admission and 24 to 48 hours before the planned discharge. A control cohort of 182 consecutive patients was retrospectively included from May 2017 to October 2017. The primary composite endpoint was mortality or readmission for HF at 6 months. The secondary endpoints were mortality, readmission for HF, and quality of care (evidence-based medications, management of HF comorbidities, and planned care plan). There was no difference among baseline characteristics between PCL and control cohorts; mean age was 78.1 +/- 12.2 vs. 79.0 +/- 12.5 years old (P = 0.46) and 61 patients (43.9%) vs. 63 (34.6%) had HF with left ventricular ejection fraction (LVEF) = 40%) LVEF showed no significant difference among groups. There was a non-significant trend toward a reduction in HF readmission rate in the PCL group [38 patients (27.3%) vs. 64 patients (35.2%), HR: 0.73, 95%CI (0.49-1.09), P = 0.13]. There was no difference regarding survival or the use of evidence-based medications. A higher proportion of patients were screened and treated for iron and vitamin D deficiencies (53.2% vs. 35.7%, P < 0.01 and 73.4% vs. 29.7%, P < 0.01, respectively), as well as malnutrition supplemented in the PCL group. There was a higher referral to HF follow-up programme in the PCL group but not to telemedicine or cardiac rehabilitation programs. Conclusions In this preliminary study, the use of a PCL did not improve outcomes at 6 months in patients hospitalized for acute HF. There was a non-significant trend towards a reduction in HF readmission rate in the PCL group. In addition, the management of HF comorbidities was significantly improved by PCL with a better referral to follow-up programme. A multicentre study is warranted to assess the usefulness of a simple costless personalized checklist in a large HF patients' population

    Indications actuelles de la contre-pulsion par ballonnet intra-aortique : le registre CP-GARO

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    International audienceBACKGROUND: Intra-aortic balloon pumps (IABPs) have been used routinely since the 1970s. Recently, large randomized trials failed to show that IABP therapy has meaningful benefit, and international recommendations downgraded its place, particularly in cardiogenic shock. AIMS: The aim of this registry was to describe the contemporary use of IABP therapy, in light of these new data. METHODS: This prospective multicentre registry included 172 patients implanted with an IABP in 19 French cardiac centres in 2015. Baseline characteristics, aetiologies leading to IABP use, and IABP-related and disease-related complications were assessed. In-hospital and 1-year mortality rates were studied. RESULTS: A total of 172 patients were included (mean age 65.5±12.0 years; 118 men [68.6%]). The reasons for IABP implantation were mainly haemodynamic (n=107; 62.2%), followed by bridge to revascularization (n=34; 19.8%) and four other "rare" aetiologies (n=29 patients; 16.8%). In-hospital and 1-year mortality rates were 40.7% and 45.8%, respectively. Fourteen patients (8.1%) experienced ischaemic or haemorrhagic complications, which were directly related to the IABP in seven patients (4.1%). CONCLUSIONS: Despite current international guidelines regarding the place of IABPs in ischaemic cardiogenic shock without mechanical complications, this aetiology remains the leading cause for its utilization in the contemporary era
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