Assessment of sediment and organic carbon exports into the Arctic ocean: the case of the Yenisei river basin

The export of organic carbon export by the rivers to the oceans either as particulate organic carbon (POC) or dissolved organic carbon (DOC) is very sensitive to climate change especially in permafrost affected catchments where soils are very rich in organic carbon. With global warming, organic carbon export in both forms is expected to increase in Arctic regions. It should affect contemporary biogeochemical cycles in rivers and oceans and therefore modify the whole food web. This study tries to understand complex processes involved in sediment, POC and DOC riverine transport in the Yenisei River basin and to quantify their respective fluxes at the river outlet. The SWAT (Soil and Water Assessment Tool) hydrological model is used in this study to simulate water and suspended sediment transfers in the largest Arctic river. POC and DOC export have been quantified with empirical models, adapted from literature for the study case. First, the hydrological model has been calibrated and validated at a daily time step for the 2003–2008 and the 2009–2016 periods respectively, and its output has been compared with field data for water and sediment fluxes. Based on conceptualization of transfer processes, calibration on climate and soil properties has been performed in order to correctly represent hydrology and sediment transfer in permafrost basins. Second, calibration of empirical models for DOC/POC transport have been performed by comparing their output with field data, available from 2003 to 2016. Our study reveals that SWAT is capable of correctly representing hydrology, sediment transfer, POC and DOC fluxes and their spatial distribution at a daily timescale, and outlines the links between these fluxes and permafrost features. Our simulation effort results in specific sediment, POC and DOC fluxes of 2.97 t km−2 yr−1, 0.13 t km−2 yr−1 and 1.14 t km−2 yr−1 for the period 2003–2016 which are in the range of previous estimates. About 60% of the total fluxes of sediment, DOC and POC to the Arctic Ocean are exported during the two months of the freshet. Spatial analysis show that permafrost-free areas have returned higher daily organic carbon export than permafrost affected zones, highlighting the thawing permafrost effect on carbon cycle in climate change feedback

China at Skin Level : english- and french-speaking agents of influence in China and chinese bodily difference : from the 1830s to the early 1920s

Des années 1830 aux premières années de la République chinoise, services diplomatiques occidentaux et sociétés missionnaires attendent des agents qu’ils déploient dans l’Empire des Qing qu’ils désamorcent la prétendue xénophobie chinoise pour faciliter la pénétration diplomatique, commerciale et évangélique du pays. Cette préoccupation constitue l’accès à l’intimité des populations et des autorités chinoises en enjeu crucial et fait des médecins missionnaires protestants comme des médecins français détachés auprès du Quai d’Orsay des acteurs importants des politiques d’influence diplomatiques et évangéliques en Chine. C’est à la lumière de ces dernières que cette thèse aborde les savoirs occidentaux sur la différence chinoise des corps. Le décalage entre l’absence de cohérence raciale de la Chine pour l’anthropologie raciale du XIXe siècle et l’essor, tout au long du siècle, de savoirs relatifs aux corps chinois invite en effet à étudier ces derniers, non comme une simple déclinaison de théories raciales, mais à partir même des savoirs pratiques développés sur le terrain par les diplomates, missionnaires et médecins anglophones et francophones que nous choisissons de désigner comme agents d’influence occidentaux en Chine. Parce qu’on attend d’eux qu’ils sachent interagir, négocier avec des interlocuteurs chinois, les convertir ou les soigner, il leur incombe de déterminer ce que l’écart entre corps occidentaux et chinois leur impose d’ajustements et d’apprentissages. C’est dans l’incorporation même des dispositions qu’il leur faut donc acquérir – depuis la maîtrise de l’étiquette chinoise jusqu’au savoir-faire de la pratique médicale en Chine – que sourdent les réflexions sur cet écart corporel, dont les stéréotypes relatifs aux corps chinois qui se figent progressivement au cours du siècle constituent bien souvent autant de vies posthumes. À les étudier ainsi au plus près de la pratique, on se donne les moyens de saisir ce que les savoirs sur la différence chinoise des corps au XIXe siècle doivent à une diversité de théories savantes autant qu’aux enjeux professionnels et aux ambitions sinologiques qui guident les agents d’influence sur le terrain ; à leur expérience corporelle et sensible de la Chine autant qu’aux processus de co-construction qui mettent en jeu divers types de fixeurs et de savoirs chinois.From the 1830s to the early years of the Chinese Republic, Western diplomatic services and missionary societies expected the agents they dispatched to the Qing Empire to defuse the alleged Chinese xenophobia and ease the penetration of the country. Accessing the intimacy of Chinese laymen and officials became a critical issue, and medicine a key tool of diplomatic and evangelical influence policies in China. This thesis examines Western knowledge on Chinese bodily difference in the light of these policies. Nineteenth-century racial anthropology recognised no such thing as a Chinese race, and yet knowledge regarding Chinese bodies flourished throughout the century. This thesis argues that this knowledge should not be understood as a mere offshoot of racial theories, but investigated as the result of fieldwork practices by anglophone and francophone diplomats, missionaries and doctors, thereafter labelled as Western agents of influence in China. The incorporation of the diverse skills they had to acquire in China – ranging from the mastery of etiquette to the know-hows of medical practice – played a critical part on how they conceived of the gap between Western and Chinese bodies. While these reflections drew from a variety of scholarly theories, they were equally indebted to the professional stakes and sinological ambitions that drove these agents in the field, to their bodily and sensitive experience of China, and to the processes of co-construction that brought into play a variety of Chinese knowledge and brokers

"Lire les corps. Présentation"

International audienc

"Lire les corps" numéro spécial, n° 123, Genèses

International audienc

Implementation of Recommendations on the Use of Corticosteroids in Severe COVID-19

Importance: Research diversity and representativeness are paramount in building trust, generating valid biomedical knowledge, and possibly in implementing clinical guidelines. Objectives: To compare variations over time and across World Health Organization (WHO) geographic regions of corticosteroid use for treatment of severe COVID-19; secondary objectives were to evaluate the association between the timing of publication of the RECOVERY (Randomised Evaluation of COVID-19 Therapy) trial (June 2020) and the WHO guidelines for corticosteroids (September 2020) and the temporal trends observed in corticosteroid use by region and to describe the geographic distribution of the recruitment in clinical trials that informed the WHO recommendation. Design, setting, and participants: This prospective cohort study of 434 851 patients was conducted between January 31, 2020, and September 2, 2022, in 63 countries worldwide. The data were collected under the auspices of the International Severe Acute Respiratory and Emerging Infections Consortium (ISARIC)-WHO Clinical Characterisation Protocol for Severe Emerging Infections. Analyses were restricted to patients hospitalized for severe COVID-19 (a subset of the ISARIC data set). Exposure: Corticosteroid use as reported to the ISARIC-WHO Clinical Characterisation Protocol for Severe Emerging Infections. Main outcomes and measures: Number and percentage of patients hospitalized with severe COVID-19 who received corticosteroids by time period and by WHO geographic region. Results: Among 434 851 patients with confirmed severe or critical COVID-19 for whom receipt of corticosteroids could be ascertained (median [IQR] age, 61.0 [48.0-74.0] years; 53.0% male), 174 307 (40.1%) received corticosteroids during the study period. Of the participants in clinical trials that informed the guideline, 91.6% were recruited from the United Kingdom. In all regions, corticosteroid use for severe COVID-19 increased, but this increase corresponded to the timing of the RECOVERY trial (time-interruption coefficient 1.0 [95% CI, 0.9-1.2]) and WHO guideline (time-interruption coefficient 1.9 [95% CI, 1.7-2.0]) publications only in Europe. At the end of the study period, corticosteroid use for treatment of severe COVID-19 was highest in the Americas (5421 of 6095 [88.9%]; 95% CI, 87.7-90.2) and lowest in Africa (31 588 of 185 191 [17.1%]; 95% CI, 16.8-17.3). Conclusions and relevance: The results of this cohort study showed that implementation of the guidelines for use of corticosteroids in the treatment of severe COVID-19 varied geographically. Uptake of corticosteroid treatment was lower in regions with limited clinical trial involvement. Improving research diversity and representativeness may facilitate timely knowledge uptake and guideline implementation

Characteristics and outcomes of COVID-19 patients admitted to hospital with and without respiratory symptoms

Background: COVID-19 is primarily known as a respiratory illness; however, many patients present to hospital without respiratory symptoms. The association between non-respiratory presentations of COVID-19 and outcomes remains unclear. We investigated risk factors and clinical outcomes in patients with no respiratory symptoms (NRS) and respiratory symptoms (RS) at hospital admission. Methods: This study describes clinical features, physiological parameters, and outcomes of hospitalised COVID-19 patients, stratified by the presence or absence of respiratory symptoms at hospital admission. RS patients had one or more of: cough, shortness of breath, sore throat, runny nose or wheezing; while NRS patients did not. Results: Of 178,640 patients in the study, 86.4 % presented with RS, while 13.6 % had NRS. NRS patients were older (median age: NRS: 74 vs RS: 65) and less likely to be admitted to the ICU (NRS: 36.7 % vs RS: 37.5 %). NRS patients had a higher crude in-hospital case-fatality ratio (NRS 41.1 % vs. RS 32.0 %), but a lower risk of death after adjusting for confounders (HR 0.88 [0.83-0.93]). Conclusion: Approximately one in seven COVID-19 patients presented at hospital admission without respiratory symptoms. These patients were older, had lower ICU admission rates, and had a lower risk of in-hospital mortality after adjusting for confounders