19 research outputs found

    Towards comprehensive observing and modeling systems for monitoring and predicting regional to coastal sea level

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    A major challenge for managing impacts and implementing effective mitigation measures and adaptation strategies for coastal zones affected by future sea level (SL) rise is our limited capacity to predict SL change at the coast on relevant spatial and temporal scales. Predicting coastal SL requires the ability to monitor and simulate a multitude of physical processes affecting SL, from local effects of wind waves and river runoff to remote influences of the large-scale ocean circulation on the coast. Here we assess our current understanding of the causes of coastal SL variability on monthly to multi-decadal timescales, including geodetic, oceanographic and atmospheric aspects of the problem, and review available observing systems informing on coastal SL. We also review the ability of existing models and data assimilation systems to estimate coastal SL variations and of atmosphere-ocean global coupled models and related regional downscaling efforts to project future SL changes. We discuss (1) observational gaps and uncertainties, and priorities for the development of an optimal and integrated coastal SL observing system, (2) strategies for advancing model capabilities in forecasting short-term processes and projecting long-term changes affecting coastal SL, and (3) possible future developments of sea level services enabling better connection of scientists and user communities and facilitating assessment and decision making for adaptation to future coastal SL change.RP was funded by NASA grant NNH16CT00C. CD was supported by the Australian Research Council (FT130101532 and DP 160103130), the Scientific Committee on Oceanic Research (SCOR) Working Group 148, funded by national SCOR committees and a grant to SCOR from the U.S. National Science Foundation (Grant OCE-1546580), and the Intergovernmental Oceanographic Commission of UNESCO/International Oceanographic Data and Information Exchange (IOC/IODE) IQuOD Steering Group. SJ was supported by the Natural Environmental Research Council under Grant Agreement No. NE/P01517/1 and by the EPSRC NEWTON Fund Sustainable Deltas Programme, Grant Number EP/R024537/1. RvdW received funding from NWO, Grant 866.13.001. WH was supported by NASA (NNX17AI63G and NNX17AH25G). CL was supported by NASA Grant NNH16CT01C. This work is a contribution to the PIRATE project funded by CNES (to TP). PT was supported by the NOAA Research Global Ocean Monitoring and Observing Program through its sponsorship of UHSLC (NA16NMF4320058). JS was supported by EU contract 730030 (call H2020-EO-2016, “CEASELESS”). JW was supported by EU Horizon 2020 Grant 633211, Atlantos

    Altimetry for the future: Building on 25 years of progress

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    In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the ‘‘Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

    Altimetry for the future: building on 25 years of progress

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    In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the “Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

    Effects of Landiolol on Macrocirculatory Parameters and Left and Right Ventricular Performances Following Cardiac Surgery: A Randomized Controlled Trial

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    International audienceObjectifs : La fibrillation auriculaire postopĂ©ratoire (FAOP) est une complication majeure aprĂšs chirurgie cardiaque, et une introduction postopĂ©ratoire prĂ©coce de bĂȘta-bloquants est recommandĂ©e pour rĂ©duire son incidence. Landiolol, un nouveau bĂȘta-bloquant intraveineux Ă  courte durĂ©e d'action, pourrait prĂ©senter un profil macrohĂ©modynamique utile et sĂ»r aprĂšs une chirurgie cardiaque. Les effets mĂ©taboliques et hĂ©modynamiques dĂ©taillĂ©s du landiolol sur les performances cardiaques restent cependant mal documentĂ©s. Les auteurs visaient Ă  Ă©tudier les effets hĂ©modynamiques et mĂ©taboliques dose-dĂ©pendants du landiolol dans ce contexte spĂ©cifique.Conception : Une Ă©tude prospective, randomisĂ©e, en double aveugle versus placebo.Cadre : Un hĂŽpital universitaire tertiaire.Participants : Patients adultes programmĂ©s pour une chirurgie cardiaque Ă©lective avec circulation extracorporelle.Interventions : Des doses incrĂ©mentielles de landiolol intraveineux (0,5, 1, 2, 5 et 10 ÎŒg/kg/min) ont Ă©tĂ© administrĂ©es dans les 2 heures suivant l'arrivĂ©e Ă  l'unitĂ© de soins intensifs. Les paramĂštres macrocirculatoires et les performances cardiaques ont Ă©tĂ© dĂ©rivĂ©s de la thermodilution transpulmonaire et de l'Ă©chocardiographie transthoracique. Les donnĂ©es mĂ©taboliques ont Ă©tĂ© obtenues Ă  partir de tests sanguins artĂ©riels.Mesures et principaux rĂ©sultats : De janvier Ă  novembre 2019, 58 patients ont Ă©tĂ© analysĂ©s et rĂ©partis en un groupe landiolol (n=30) et un groupe contrĂŽle (n=28). La frĂ©quence cardiaque a significativement diminuĂ© dans le groupe landiolol (p < 0,01), tandis que la pression artĂ©rielle moyenne et le volume d'Ă©jection systolique sont restĂ©s inchangĂ©s. Aucune modification significative n'a Ă©tĂ© trouvĂ©e dans les performances systolique et diastolique gauche et droite. Les variables mĂ©taboliques Ă©taient similaires dans les deux groupes. Une FAOP d'apparition rĂ©cente est survenue chez 9 (32 %) contre 5 (17 %) patients dans les groupes contrĂŽle et landiolol, respectivement (p = 0,28).Conclusions : La perfusion de landiolol dans la plage de 0,5 Ă  10 ÎŒg/kg/min au cours de la pĂ©riode postopĂ©ratoire prĂ©coce prĂ©sente un bon profil d'innocuitĂ© macrohĂ©modynamique chez les patients en chirurgie cardiaque et pourrait ĂȘtre utile pour prĂ©venir la FAOP

    Prediction of retention for sulfonamides in supercritical fluid chromatography

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    Properties-retention studies were undertaken on a test library of sulfonamides using supercritical fluid chromatography with CO2-MeOH mobile phases (in the presence or absence of additive) and a 2-ethyl-pyridyl column. Taking a restricted range of retention ratios, k (1 &lt; k &lt; 10) and keeping the proportion of modifier in the mobile phase, ?, above 10%, it was shown that log k varies linearly with ? (R2 &gt; 0.98). From these relationships, the different retention characteristics of the analytes were calculated. Literature studies of quantitative structure–retention relationships (QSRR) showed that these characteristics can be correlated with simple molecular descriptors to derive equations predicting the retention behaviour of new compounds. Measured retention characteristics were found to correlate with total dipole moment, ?, molecular surface area, A, and the electronic charge on the most negatively charged atom, ?min. The correlation of chromatographic measurements with calculated molecular descriptors may allow the prediction of the retention behaviour for an unknown compound provided its properties are known

    Effect of increasing concentration of ammonium acetate as an additive in supercritical fluid chromatography using CO2–methanol mobile phase

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    The effects of increasing concentrations of ammonium acetate additive in supercritical fluid chromatography were studied on silica, 2-ethyl-pyridine and endcapped 2-ethyl-pyridine stationary phases. The study involved the addition of increasing concentrations of the ammonium acetate either in the mobile phase modifier (methanol) or in the sample solvent. The effects of ammonium acetate on retention and peak shape of the analytes were evaluated. Compounds that exhibited satisfactory chromatographic behaviour in the absence of the additive were virtually unaffected by its presence in the mobile phase or sample solvent. Nevertheless, compounds that exhibited late elution and strongly tailing peak shapes when pure methanol was used showed dramatically improved chromatographic behaviour in the presence of the additive. Shorter retention was observed not only when the modifier was introduced in the mobile phase but also when it was in the sample solvent.<br/

    Contributions of altimetry and Argo to non‐closure of the global mean sea level budget since 2016

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    Over 1993-2016, studies have shown that the observed global mean sea level (GMSL) budget is closed within the current data uncertainties. However, non-closure of the budget was recently reported when using Jason-3, Argo and GRACE/GRACE Follow-On data after 2016. This non-closure may result from errors in the datasets used to estimate the GMSL and its components. Here, we investigate possible sources of errors affecting Jason-3 and Argo data. Comparisons of Jason-3 GMSL trends with other altimetry missions show good agreement within 0.4 mm/yr over 2016-present. Besides, the wet tropospheric correction uncertainty from the Jason-3 radiometer contributes to up to 0.2 mm/yr. Therefore, altimetry alone cannot explain the misfit in the GMSL budget observed after 2016. Argo-based salinity products display strong discrepancies since 2016, attributed to instrumental problems and data editing issues. Re-assessment of the sea level budget with the thermosteric component provides about 40 % improvement in the budget closure. Plain Language Summary Sea level rise, due to the addition of meltwater from glaciers and ice-sheets in the oceans and to the thermal expansion of seawater, is commonly used as an indicator for climate change. The sea level budget provides information on temporal changes in one or more components of the budget, on process understanding, on missing contributions and allows cross validation of the observing systems involved in the sea level budget (satellite altimetry, Argo oceanic float and GRACE/GRACE Follow-On satellite gravimetry). The sea level budget was closed until 2015-2016, i.e. the observed global mean sea level agrees well with the sum of components. However, since 2016, the budget is not closed anymore. In this study, we show that errors in Argo salinity measurements are responsible for about 40 % of the budget error while the altimetry data cannot explain the remaining error. Other sources of errors should be further investigated to fully understand the error in the budget after 2016, in particular satellite GRACE/GRACE Follow-On gravity measurements or missing physical contributions

    Prevalence and Recovery From Olfactory and Gustatory Dysfunctions in Covid-19 Infection: A Prospective Multicenter Study

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    International audienceBackground Covid-19 is defined by an association of multiple symptoms, including frequently reported olfactory and gustatory disorders. Objective The main purpose of this study was to analyze the prevalence of these neurosensory impairments in patients with Covid-19, and to assess short-term recovery. Methods We performed a multicenter case series study during the Covid-19 epidemic. All patients presenting a RT-PCR-confirmed SARS-CoV-2 infection were included, whether hospitalized or treated at home. To analyze the prevalence and features of olfactory and gustatory dysfunctions, a phone interview was conducted 5 days after the positive PCR result. The questionnaire was submitted again 10 days later to patients having reported olfactory and gustatory disorders, in order to assess their recovery. Results 115 patients were included in our study. 81 patients (70%) reported olfactory and gustatory disorders without nasal obstruction or rhinorrhea. These impairments were more frequently reported in the female population, young people, and house-bound patients with mild symptomatic forms. Short-term recovery assessed at Day 15 was complete for 64% of the patients, and incomplete in 33%. Median recovery time was 15 days (4–27 days) after olfactory or gustatory symptom onset. Conclusion Olfactory and gustatory dysfunctions related to Covid-19 are frequently reported and prevalent in mild symptomatic forms of the disease. Recovery in most cases seems rapid and complete

    Guidelines on perioperative optimization protocol for the adult patient 2023

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    International audienceObjective: The French Society of Anesthesiology and Intensive Care Medicine [SociĂ©tĂ© Française d'AnesthĂ©sie et de RĂ©animation (SFAR)] aimed at providing guidelines for the implementation of perioperative optimization programs. Design: A consensus committee of 29 experts from the SFAR was convened. A formal conflict-of-interest policy was developed at the outset of the process and enforced throughout. The entire guidelines process was conducted independently of any industry funding. The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide assessment of quality of evidence. Methods: Four fields were defined: 1) Generalities on perioperative optimization programs; 2) Preoperative measures; 3) Intraoperative measures and; 4) Postoperative measures. For each field, the objective of the recommendations was to answer a number of questions formulated according to the PICO model (population, intervention, comparison, and outcomes). Based on these questions, an extensive bibliographic search was carried out using predefined keywords according to PRISMA guidelines and analyzed using the GRADEÂź methodology. The recommendations were formulated according to the GRADEÂź methodology and then voted on by all the experts according to the GRADE grid method. As the GRADEÂź methodology could have been fully applied for the vast majority of questions, the recommendations were formulated using a “formalized expert recommendations” format. Results: The experts' work on synthesis and application of the GRADEÂź method resulted in 30 recommendations. Among the formalized recommendations, 19 were found to have a high level of evidence (GRADE 1±) and ten a low level of evidence (GRADE 2±). For one recommendation, the GRADE methodology could not be fully applied, resulting in an expert opinion. Two questions did not find any response in the literature. After two rounds of rating and several amendments, strong agreement was reached for all the recommendations. Conclusions: Strong agreement among the experts was obtained to provide 30 recommendations for the elaboration and/or implementation of perioperative optimization programs in the highest number of surgical fields
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