12 research outputs found

    Mg/Ca-Temperature Calibration of Polar Benthic foraminifera species for reconstruction of bottom water temperatures on the Antarctic shelf

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    Benthic foraminifera Mg/Ca is a well-established bottom water temperature (BWT) proxy used in paleoclimate studies. The relationship between Mg/Ca and BWT for numerous species has been determined using core-top and culturing studies. However, the scarcity of calcareous microfossils in Antarctic shelf sediments and poorly defined calibrations at low temperatures has limited the use of the foraminiferal Mg/Ca paleothermometer in ice proximal Antarctic sediments. Here we present paired ocean temperature and modern benthic foraminifera Mg/Ca data for three species, Trifarina angulosa, Bulimina aculeata, and Globocassidulina subglobosa, but with a particular focus on Trifarina angulosa. The core-top data from several Antarctic sectors span a BWT range of −1.7 to +1.2 °C and constrain the relationship between Mg/Ca and cold temperatures. We compare our results to published lower-latitude core-top data for species in the same or related genera, and in the case of Trifarina angulosa, produce a regional calibration. The resulting regional equation for Trifarina angulosa is Temperature (°C) = (Mg/Ca −1.14 ± 0.035)/0.069 ± 0.033). Addition of our Trifarina angulosa data to the previously published Uvigerina spp. dataset provides an alternative global calibration, although some data points appear to be offset from this relationship and are discussed. Mg-temperature relationships for Bulimina aculeata and Globocassidulina subglobosa are also combined with previously published data to produce calibration equations of Temperature (°C) = (Mg/Ca-1.04 ± 0.07)/0.099 ± 0.01 and Temperature (°C) = (Mg/Ca-0.99 ± 0.03)/0.087 ± 0.01, respectively. These refined calibrations highlight the potential utility of benthic foraminifera Mg/Ca-paleothermometry for reconstructing past BWT in Antarctic margin settings

    Large subglacial source of mercury from the southwestern margin of the Greenland Ice Sheet

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    The Greenland Ice Sheet is currently not accounted for in Arctic mercury budgets, despite large and increasing annual runoff to the ocean and the socio-economic concerns of high mercury levels in Arctic organisms. Here we present concentrations of mercury in meltwaters from three glacial catchments on the southwestern margin of the Greenland Ice Sheet and evaluate the export of mercury to downstream fjords based on samples collected during summer ablation seasons. We show that concentrations of dissolved mercury are among the highest recorded in natural waters and mercury yields from these glacial catchments (521–3,300 mmol km−2 year−1) are two orders of magnitude higher than from Arctic rivers (4–20 mmol km−2 year−1). Fluxes of dissolved mercury from the southwestern region of Greenland are estimated to be globally significant (15.4–212 kmol year−1), accounting for about 10% of the estimated global riverine flux, and include export of bioaccumulating methylmercury (0.31–1.97 kmol year−1). High dissolved mercury concentrations (~20 pM inorganic mercury and ~2 pM methylmercury) were found to persist across salinity gradients of fjords. Mean particulate mercury concentrations were among the highest recorded in the literature (~51,000 pM), and dissolved mercury concentrations in runoff exceed reported surface snow and ice values. These results suggest a geological source of mercury at the ice sheet bed. The high concentrations of mercury and its large export to the downstream fjords have important implications for Arctic ecosystems, highlighting an urgent need to better understand mercury dynamics in ice sheet runoff under global warming

    Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans

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    Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in 25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16 regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP, while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium (LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region. Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the refined data for existing association signals, we estimate that these loci now explain ∼38.9% of the familial relative risk of PrCa, an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent signals within the same regio

    Implementation of corticosteroids in treating COVID-19 in the ISARIC WHO Clinical Characterisation Protocol UK:prospective observational cohort study

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    BACKGROUND: Dexamethasone was the first intervention proven to reduce mortality in patients with COVID-19 being treated in hospital. We aimed to evaluate the adoption of corticosteroids in the treatment of COVID-19 in the UK after the RECOVERY trial publication on June 16, 2020, and to identify discrepancies in care. METHODS: We did an audit of clinical implementation of corticosteroids in a prospective, observational, cohort study in 237 UK acute care hospitals between March 16, 2020, and April 14, 2021, restricted to patients aged 18 years or older with proven or high likelihood of COVID-19, who received supplementary oxygen. The primary outcome was administration of dexamethasone, prednisolone, hydrocortisone, or methylprednisolone. This study is registered with ISRCTN, ISRCTN66726260. FINDINGS: Between June 17, 2020, and April 14, 2021, 47 795 (75·2%) of 63 525 of patients on supplementary oxygen received corticosteroids, higher among patients requiring critical care than in those who received ward care (11 185 [86·6%] of 12 909 vs 36 415 [72·4%] of 50 278). Patients 50 years or older were significantly less likely to receive corticosteroids than those younger than 50 years (adjusted odds ratio 0·79 [95% CI 0·70–0·89], p=0·0001, for 70–79 years; 0·52 [0·46–0·58], p80 years), independent of patient demographics and illness severity. 84 (54·2%) of 155 pregnant women received corticosteroids. Rates of corticosteroid administration increased from 27·5% in the week before June 16, 2020, to 75–80% in January, 2021. INTERPRETATION: Implementation of corticosteroids into clinical practice in the UK for patients with COVID-19 has been successful, but not universal. Patients older than 70 years, independent of illness severity, chronic neurological disease, and dementia, were less likely to receive corticosteroids than those who were younger, as were pregnant women. This could reflect appropriate clinical decision making, but the possibility of inequitable access to life-saving care should be considered. FUNDING: UK National Institute for Health Research and UK Medical Research Council

    Fludarabine, cytarabine, granulocyte colony-stimulating factor, and idarubicin with gemtuzumab ozogamicin improves event-free survival in younger patients with newly diagnosed aml and overall survival in patients with npm1 and flt3 mutations

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    Purpose To determine the optimal induction chemotherapy regimen for younger adults with newly diagnosed AML without known adverse risk cytogenetics. Patients and Methods One thousand thirty-three patients were randomly assigned to intensified (fludarabine, cytarabine, granulocyte colony-stimulating factor, and idarubicin [FLAG-Ida]) or standard (daunorubicin and Ara-C [DA]) induction chemotherapy, with one or two doses of gemtuzumab ozogamicin (GO). The primary end point was overall survival (OS). Results There was no difference in remission rate after two courses between FLAG-Ida + GO and DA + GO (complete remission [CR] + CR with incomplete hematologic recovery 93% v 91%) or in day 60 mortality (4.3% v 4.6%). There was no difference in OS (66% v 63%; P = .41); however, the risk of relapse was lower with FLAG-Ida + GO (24% v 41%; P < .001) and 3-year event-free survival was higher (57% v 45%; P < .001). In patients with an NPM1 mutation (30%), 3-year OS was significantly higher with FLAG-Ida + GO (82% v 64%; P = .005). NPM1 measurable residual disease (MRD) clearance was also greater, with 88% versus 77% becoming MRD-negative in peripheral blood after cycle 2 (P = .02). Three-year OS was also higher in patients with a FLT3 mutation (64% v 54%; P = .047). Fewer transplants were performed in patients receiving FLAG-Ida + GO (238 v 278; P = .02). There was no difference in outcome according to the number of GO doses, although NPM1 MRD clearance was higher with two doses in the DA arm. Patients with core binding factor AML treated with DA and one dose of GO had a 3-year OS of 96% with no survival benefit from FLAG-Ida + GO. Conclusion Overall, FLAG-Ida + GO significantly reduced relapse without improving OS. However, exploratory analyses show that patients with NPM1 and FLT3 mutations had substantial improvements in OS. By contrast, in patients with core binding factor AML, outcomes were excellent with DA + GO with no FLAG-Ida benefit

    Para-infectious brain injury in COVID-19 persists at follow-up despite attenuated cytokine and autoantibody responses

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    To understand neurological complications of COVID-19 better both acutely and for recovery, we measured markers of brain injury, inflammatory mediators, and autoantibodies in 203 hospitalised participants; 111 with acute sera (1–11 days post-admission) and 92 convalescent sera (56 with COVID-19-associated neurological diagnoses). Here we show that compared to 60 uninfected controls, tTau, GFAP, NfL, and UCH-L1 are increased with COVID-19 infection at acute timepoints and NfL and GFAP are significantly higher in participants with neurological complications. Inflammatory mediators (IL-6, IL-12p40, HGF, M-CSF, CCL2, and IL-1RA) are associated with both altered consciousness and markers of brain injury. Autoantibodies are more common in COVID-19 than controls and some (including against MYL7, UCH-L1, and GRIN3B) are more frequent with altered consciousness. Additionally, convalescent participants with neurological complications show elevated GFAP and NfL, unrelated to attenuated systemic inflammatory mediators and to autoantibody responses. Overall, neurological complications of COVID-19 are associated with evidence of neuroglial injury in both acute and late disease and these correlate with dysregulated innate and adaptive immune responses acutely

    Mutation studies in lacI

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    Mg/Ca-Temperature Calibration of Polar Benthic foraminifera species for reconstruction of bottom water temperatures on the Antarctic shelf

    Get PDF
    Benthic foraminifera Mg/Ca is a well-established bottom water temperature (BWT) proxy used in paleoclimate studies. The relationship between Mg/Ca and BWT for numerous species has been determined using core-top and culturing studies. However, the scarcity of calcareous microfossils in Antarctic shelf sediments and poorly defined calibrations at low temperatures has limited the use of the foraminiferal Mg/Ca paleothermometer in ice proximal Antarctic sediments. Here we present paired ocean temperature and modern benthic foraminifera Mg/Ca data for three species, Trifarina angulosa, Bulimina aculeata, and Globocassidulina subglobosa, but with a particular focus on Trifarina angulosa. The core-top data from several Antarctic sectors span a BWT range of -1.7 to 1.2˚C and constrain the relationship between Mg/Ca and cold temperatures. We compare our results to published lower-latitude core-top data for species in the same or related genera, and in the case of Trifarina angulosa, produce a regional calibration. The resulting regional equation for Trifarina angulosa is Temperature (°C) = (Mg/Ca -1.14±0.035)/0.069±0.033). Addition of our Trifarina angulosa data to the previously published Uvigerina spp. dataset provides and alternative global calibration, although some data points appear to be offset from this relationship and are discussed. Mg-temperature relationships for Bulimina aculeata and Globocassidulina subglobosa are also combined with previously published data to produce calibration equations of Temperature (°C) = (Mg/Ca-1.04±0.07)/0.099±0.01 and Temperature (°C) = (Mg/Ca-0.99±0.03)/0.087±0.01, respectively. These refined calibrations highlight the potential utility of benthic foraminifera Mg/Ca-paleothermometry for reconstructing past BWT in Antarctic margin settings, although further work is required before they are routinely used

    Photochemical Oxidation of a Manganese(III) Complex with Oxygen and Toluene Derivatives to Form a Manganese(V)-Oxo Complex

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