COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Influence of planktonic foodweb structure on a system's capacity to support pelagic production: an inverse analysis approach

International audienceCoupled plankton/small pelagic (SP) fish systems were analysed to assess how foodweb structure influences the export of carbon topelagic fish during the spring bloom in the Bay of Biscay. The investigation of carbon export flows through inverse analysis was supplementedby estimating the carrying capacity for pelagic fish production by applying linear programming. A planktonic foodwebdominated by microbial pathways had the highest trophic efficiency owing to the tight coupling between planktonic trophiclevels and predation pressure on mesozooplankton by fish. Moreover, the magnitude of the gap between carrying capacity and estimatedcarbon export was related to the size structure of primary producers, with the picophytoplankton-based foodweb having thesmallest gap and the microphytoplankton-based one the largest gap. Planktonic foodwebs dominated by small autotrophic cells channelledmost of their available carbon to pelagic fish production, whereas foodwebs dominated by large phytoplankton were bettersuited to benthic communities with a large loss of carbon through sedimentation. Although the total carbon available to highertrophic levels does not vary with the size of the main primary producers, the potential export to SP fish depends on the structureof the planktonic foodweb

Valorization of mineral waste through accelerated carbonation

Mineral waste is by far the largest waste stream in Europe. Unlike other waste streams, it is rarely recycled and is predominantly disposed of in landfills. The aim of this study is to bring added value to some mineral waste by valorizing them as a partial substitute for cement in mortar composition. To this end, mineral wastes are first crushed to obtain particle sizes ranging from 0 to 100 μm. Half of the resulting fine particles undergoes a carbonation process. Tests are carried out on fresh mortars in which cement is partially replaced by carbonated or non-carbonated fines, to evaluate their impact on mortars workability. Initial findings indicate that, at a fixed substitution rate, carbonation of the studied fines improves the workability of the mortars by reducing their porosity. Tests are also conducted on hardened mortar specimens to determine their mechanical strength. Preliminary tests indicate that carbonation treatment of fines contributes to improve the mechanical performances of mortar specimens compared to specimens made of raw fines, although both result in a loss of mechanical properties when substituted to Portland cement. It also helps to reduce the porosity of the hardened mortar and, consequently, improves its durability. In conclusion, substituting cement with carbonated fines slightly improves the durability of mortars, and reduces the loss of mechanical strength compared to mortars made with non-carbonated fines. Workability is also improved when fines are carbonated.Mineral Loo

Community structure and grazing of the nano-microzooplankton on the continental shelf of the Bay of Biscay

International audienceIn order to investigate the parameters controlling the heterotrophic protists (nano-microzooplankton) on the continental shelf of the southern Bay of Biscay, plankton communities and their physico-chemical environment were studied 4 times in February, April, June and SeptembereOctober 2004 at three stations in the euphotic zone in the Bay of Biscay. The abundance and carbon biomass of heterotrophic protists (ciliates, heterotrophic dinoflagellates and nanoflagellates) as well as all the others groups of plankton (picoplankton, nanophytoplankton, diatoms, autotrophic dinoflagellates, metazoan micro-zooplankton and mesozooplankton), the environmental parameters and the primary and bacteria production were evaluated at each sampling period. Microzooplankton grazing experiments were undertaken at the same time. Ciliates and heterotrophic dinoflagellates accounted for the main major component of nano-and microzooplankton communities in term of biomass. The total carbon biomass of heterotrophic protists was highest in spring and lowest at the end of summer. The development of heterotrophic protists started after a winter microphytoplankton bloom (principally large diatoms), the biomass was lower in June and was low in September (through inappropriate prey). The carbon requirement of microzooplankton ranged from 50 to more than 100% of daily primary, bacterial and nanoflagellate production. The heterotrophic protist community was predominantly constrained by bottom-up control in spring and at the end of summer via food availability and quality

Tropical harmful algal blooms: an emerging threat to coral reef communities?

Tropical harmful algal blooms (HABs) are increasing in frequency and intensity and are substantially affecting marine communities. In October/November 2008 a large-scale HAB event (> 500 km2, dinoflagellate Cochlodinium polykrikoides) in the Gulf of Oman caused the complete loss of the branching corals, Pocillopora and Acropora spp., and substantial reductions in the abundance, richness and trophic diversity of the associated coral reef fish communities. Although the causative agents of this C. polykrikoides bloom are unknown, increased coastal enrichment, natural oceanographic mechanisms, and the recent expansion of this species within ballast water discharge are expected to be the main agents. With rapid changes in oceanic climate, enhanced coastal eutrophication and increased global distribution of HAB species within ballast water, large-scale HAB events are predicted to increase dramatically in both intensity and distribution and can be expected to have increasingly negative effects on coral reef communities globally

Spatio-temporal drivers of microphytoplankton community in the Bay of Biscay: do species ecological niches matter?

From 2000 to 2016, substantial changes in biomass and community structure of small pelagic fish and mesozooplankton have been reported in the Bay of Biscay. Since significant relationships have been found between phytoplankton chlorophyll a and mesozooplankton as well as between phytoplankton chlorophyll a and shifts in sardine body condition, it was hypothesized that phytoplankton communities may have also been affected during this period and may have played a role in these changes. However, the available data were insufficient to validate this hypothesis and the causes of these changes remained unexplained. The present study analyzed a spatio-temporal marine microphytoplankton dataset collected during the annual PELGAS (PELagiques GAScogne) surveys from 2003 to 2014. The thorough analysis of microphytoplankton taxonomic composition, with an approach integrating the relative role of environmental conditions as well as biotic interactions and applying the concept of ecological niche, confirmed that significant modifications in microphytoplankton community structure occurred during this period. Temporal changes were stronger than spatial differences at these sampling scales. Three main periods, 2003-2005, 2006 and 2007-2014, showing different community structure, diversity and dominant taxonomic units were highlighted. Twenty eight taxonomic units were involved in these community changes. Among them, five were identified as the protagonists (Pseudo-nitzschia spp., Gymnodinium spp. + Gyrodinium spp., Leptocylindrus danicus, Leptocylindrus minimus and Chaetoceros sp.). Variations in water temperature and equivalent freshwater depth constrained the realized ecological niches of these species and explained, at least in part, changes in community structure. This study stresses the need to improve our knowledge of phytoplankton species ecological niches and to take into account biotic interactions for a thorough understanding of the processes shaping plankton communities and the resulting diversity patterns

The spring mesozooplankton variability and its relationship with hydrobiological structure over year-to-year changes (2003–2013) in the southern Bay of Biscay (Northeast Atlantic)

International audienceMesozooplankton can be considered the most important secondary producers in marine food webs because they hold an intermediate position between the phytoplankton assemblage and the upper trophic levels. They also are a robust indicator of climatic and hydrological conditions. We conducted an analysis of the interannual variability of the spring mesozooplankton assemblage, as sampled by the PELGAS fisheries survey in the southern part of the Bay of Biscay (Northeast Atlantic Ocean) between 2003 and 2013. We examined hydrology and trophic drivers to explain the variability. Our results revealed that the subsurface temperature, the subsurface salinity, the biomasses of subsurface pico-, nano-, and microphytoplankton, and the copepod assemblage exhibited a recurrent spatial pattern that was driven mainly by freshwater and nutrient inputs from the main rivers. The mesozooplankton assemblage was dominated by copepods (82%), composed of coastal, neritic, and oceanic copepod genera that paralleled the various hydrological fronts converging in the southern Bay of Biscay. The copepod community displayed high temporal-variability; there were three periods of abundant adult copepods throughout the southern Bay of Biscay. The copepod community was structured primarily around the drive for resource control, especially by the microphytoplankton biomass (24.3% of the total variability), and to a lesser extent by hydrological features (13.7% of the total variability)

Comparative analysis of the food webs of two intertidal mufflats during two seasons using inverse modelling: Aiguillon Cove and Brouage Mudflat, France.

International audienceInverse analysis was used to model the food webs of two intertidal mudflat ecosystems: Aiguillon Cove (AC) and Brouage Mudflat (BM) (south-western Atlantic coast, France). The aim of the present study is to describe and compare the functioning of these two ecosystems. The method of inverse analysis has been adapted in order to take into account, in a single calculation, two seasons: spring/summer (mid-March to mid-October) and autumn/winter (the rest of the year). Gathering all available data on the two sites, the most important gaps in knowledge were identified with the help of sensitivity analyses: they concerned mainly the exports of material by grazing fish (such as mullet Liza ramada), resuspension of microphytobenthos, and fluxes linked to microfauna which is poorly known for the two systems. The two sites presented the same overall type of functioning (net import of detritus, export of living organic material and higher faunal activity during spring/summer). In both ecosystems, primary production was dominated by the microphytobenthic production, of which a great part was exported via watercolumn advection and biotic vectors (grazing fish), while many secondary producers also used detritus as a food resource. Each system also had its own characteristics, one BM being much more seasonally driven than the other AC. It appeared essential to take the seasons into account, as variations in microphytobenthos production and in meiofauna, macrofauna and biotic vectors led to great differences in the food-web organisation

The growing need for sustainable ecological management of marine communities of the Persian Gulf

The Persian Gulf is a semi-enclosed marine system surrounded by eight countries, many of which are experiencing substantial development. It is also a major center for the oil industry. The increasing array of anthropogenic disturbances may have substantial negative impacts on marine ecosystems, but this has received little attention until recently. We review the available literature on the Gulf’s marine environment and detail our recent experience in the United Arab Emirates (U.A.E.) to evaluate the role of anthropogenic disturbance in this marine ecosystem. Extensive coastal development may now be the single most important anthropogenic stressor. We offer suggestions for how to build awareness of environmental risks of current practices, enhance regional capacity for coastal management, and build cooperative management of this important, shared marine system. An excellent opportunity exists for one or more of the bordering countries to initiate a bold and effective, long-term, international collaboration in environmental management for the Gulf