80 research outputs found

    Semiotic and theoretic control within and across conceptual frames

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    Benthic O-2 uptake by coral gardens at the Condor seamount (Azores)

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    Using the non-invasive aquatic eddy covariance technique, we provide the first oxygen (O-2) uptake rates from within coral gardens at the Condor seamount (Azores). To explore some of the key drivers of the benthic O-2 demand, we obtained benthic images, quantified local hydrodynamics, and estimated phototrophic biomass and deposition dynamics with a long-term moored sediment trap. The coral gardens were dominated by the octocorals Viminella flagellum and Dentomuricea aff. meteor. Daily rates of O-2 uptake within 3 targeted coral garden sites (203 to 206 m depth) ranged from 10.0 t 0.88 to 18.8 +/- 2.0 mmol m(-2) d(-1) (mean +/- SE) and were up to 10 times higher than 2 local sandy reference sites within the seamount summit area. The overall mean O-2 uptake rate for the garden (13.4 mmol m(-2) d(-1)) was twice the global mean for sedimentary habitats at comparable depths. Combined with parallel ex situ incubations, the results suggest that the octocorals might contribute just -similar to 5% of the observed O-2 uptake rates. Deposition of particulate organic matter (POM) assessed by the sediment trap accounted for less than 10% of the O-2 demand of the coral garden, implying a substantial POM supply circumventing the deployed traps. Our results expand the database for carbon turnover rates in cold-water coral habitats by including the first estimates from these largely understudied coral gardens.Peer reviewe

    Anthropogenic influence on sediment transport in the Whittard Canyon, NE Atlantic

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    Unusual peaks in turbidity were detected in two branches of the Whittard Canyon in June 2013. Enhanced nepheloid layers (ENLs) were defined as layers with concentrations of suspended particulate matter exceeding those of nepheloid layers typically observed in a given region. Here, ENLs had peaks in turbidity and elevated suspended particulate matter concentrations exceeding ~1 mg L−1 with the largest ENLs measuring between ~2–8mg L−1. The ENLs measured ~100–260m in vertical height and were detected inwater depths of between 640 and 2880 m. Vessel Monitoring System data showed that high spatial and temporal activity of potential bottom trawling vessels coincided with the occurrence of the ENLs. Molar C/N ratios of the suspended organic material from the ENLs showed a high degree of degradation. Regular occurrences of such events are likely to have implications for increased sediment fluxes, burial of organic carbon and alteration of benthic and canyon ecosystems

    Use of hydroxychloroquine in hospitalised COVID-19 patients is associated with reduced mortality: Findings from the observational multicentre Italian CORIST study

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    Background: Hydroxychloroquine (HCQ) was proposed as potential treatment for COVID-19. Objective: We set-up a multicenter Italian collaboration to investigate the relationship between HCQ therapy and COVID-19 in-hospital mortality. Methods: In a retrospective observational study, 3,451 unselected patients hospitalized in 33 clinical centers in Italy, from February 19, 2020 to May 23, 2020, with laboratory-confirmed SARS-CoV-2 infection, were analyzed. The primary end-point in a time-to event analysis was in-hospital death, comparing patients who received HCQ with patients who did not. We used multivariable Cox proportional-hazards regression models with inverse probability for treatment weighting by propensity scores, with the addition of subgroup analyses. Results: Out of 3,451 COVID-19 patients, 76.3% received HCQ. Death rates (per 1,000 person-days) for patients receiving or not HCQ were 8.9 and 15.7, respectively. After adjustment for propensity scores, we found 30% lower risk of death in patients receiving HCQ (HR=0.70; 95%CI: 0.59 to 0.84; E-value=1.67). Secondary analyses yielded similar results. The inverse association of HCQ with inpatient mortality was particularly evident in patients having elevated C-reactive protein at entry. Conclusions: HCQ use was associated with a 30% lower risk of death in COVID-19 hospitalized patients. Within the limits of an observational study and awaiting results from randomized controlled trials, these data do not discourage the use of HCQ in inpatients with COVID-19
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