Laboratoire Écologie Fonctionnelle et Environnement

ObjectivesTo determine the Incremental Cost-Utility Ratio (ICUR) of cochlear implantation in the treatment of adult patients with single-sided deafness (SSD) and asymmetric hearing loss (AHL).MethodsThis prospective multicenter pragmatic study including a randomized controlled trial (RCT) enrolled 155 subjects with SSD or AHL. Subjects chose a treatment option between: abstention, Contralateral Routing Of the Signal hearing aids, Bone Conduction Device or Cochlear Implant (CI). Participants who opted for CI were then randomized between two arms: “immediate CI” where the cochlear implantation was performed within one month and “initial observation” where subjects were first observed. The ICUR of CI was determined at 6 months follow-up by comparing the two arms. Utility was measured using EuroQoL- 5 dimensions (EQ-5D), to calculate the gain in Quality-Adjusted Life Years (QALY). Individual costs were extracted from the French National Health Insurance database. A Markovian MultiState (MMS) model assessed the ICUR evolution over the lifetime horizon.ResultsAmong the 155 included participants, 51 opted for a CI and were randomized. For a 6 months follow-up period, the ICUR was €422,279/QALY gained after CI. Using the MMS model, the ICUR of CI decreased to €57,561/QALY at 10 years follow-up, €38,006/QALY at 20 years, and dropped to €26,715 at 50 years. In the participants with severe tinnitus, mean ICUR was €31,105/QALY at 10 years.ConclusionsCI can be considered as an efficient treatment in SSD and AHL from 20 years follow-up in the global population, and before 10 years follow-up in patients with severe associated tinnitus.

To limit global warming below 2°C, a drastic overall reduction from current green-house gas emissions is needed. Scientists should also participate in this effort in their professional activity and especially Earth scientists, on the grounds of maintaining credibility and leading by example. The strategies and measures to reach a low-carbon scientific activity require detailed estimates of the current footprint of laboratories. Here, we present the footprint of six laboratories in Earth, environmental and space sciences, with a comprehensive scope also including international research infrastructures. We propose a novel method to attribute a part of the footprint of any research infrastructure to the laboratory using it. Our results highlight that most laboratories have annual footprints reaching 10–20 tonnes CO2equivalent per person (tCO2e p-1), dominated by infrastructures and specifically satellites in three cases (with footprints up to 11 tCO2e p-1), while air-travels and purchases remain within the top three sources in all cases (2–4 tCO2e p-1 each). Consequently, footprints related to commuting and laboratory functioning, about 2 tCO2e p-1 or less, are relatively modest compared to infrastructures, purchases and air-travels. Thus, reduction measures ignoring infrastructures may not be able to achieve reductions larger than 20 to 35% even with flight quotas and a substantial reduction of purchases. Finally, we also discuss how a deeper transformation of scientific practices, away from competitive, grant-based and innovation-oriented current practices, could make Earth and environmental sciences more sustainable and at the forefront of rapid and drastic changes in the whole society toward environment and climate preservation.

Abstract While research has extensively investigated the dynamics of CO2 water partial pressure (pCO2) and planktonic food webs (PFWs) separately, there has been limited exploration of their potential interconnections, especially in marsh typologies. This study’s objectives were to (1) investigated if pCO2 and atmospheric CO2 flux can be elucidated by PFW topologies, and (2) ascertain if these potential relationships are consistent across two distinct “Blue Carbon” ecosystems. Abiotic and biotic variables were measured in two contrasting wetlands at the Atlantic French coast: a saltwater (SM, L’Houmeau) and a freshwater marsh (FM, Tasdon). SM acted as a weak carbon source, with pCO2 between 542 and 842 ppmv. Conversely, FM exhibited strong atmospheric CO2 source or sink characteristics, varying with seasons and stations, with pCO2 between 3201 and 114 ppmv. Five PFW topologies were linked to varying pCO2 across the two ecosystems: three stable topologies ('biological winter', 'microbial', 'multivorous' PFW) exhibited consistently high pCO2 values (FM: 971, 1136, 3020 ppmv; SM: 'biological winter' not observed, 842, 832 ppmv), while two transient topologies ('weak multivorous' and 'weak herbivorous') displayed lower and more variable pCO2 values (FM: from 127 to 1402 ppmv; SM: from 638 to 749 ppmv). Seasonality emerged as an influencing factor for both pCO2 dynamics and PFW. However, PFW in FM did not demonstrate a seasonal equilibrium state, potentially hindering a clearer understanding of the relationship between pCO2 and PFW. This is the first documented association between PFW topologies and pCO2 dynamics in “Blue Carbon” marsh environments.

Abstract Intraspecific variability has implications for our understanding of ecosystem functioning. Yet, beyond ontogenetic variation in body size, we know little about how phenotypic differences between individuals modulate ecosystem functioning. We addressed this question empirically within a forested stream, by studying the ecosystem effects triggered by conspecific predatory dragonfly larvae that varied in sex, body shape, behaviour and growth rate. With the help of stream enclosures, we were able to evaluate how different predator phenotypes drive cascading effects on litter‐dwelling prey, fungal biomass and leaf litter decomposition, in uncontrolled natural conditions. Some individual predators increased leaf litter standing stocks and fungal biomass compared to controls (without dragonfly larvae added), but others had the opposite effect. These contrasting effects were repeatable between the two runs of our experiment. Phenotypic effects were related to the sex and the position of individuals along a life history—behavioural continuum, and were possibly mediated by differential top‐down control of prey, or by inter‐individual variability in non‐consumptive effects. Several phenotypic dimensions are likely to mediate individual variability in predator effects on ecosystem processes, even in a complex and stochastic natural context such as a forested stream. We invite further investigations that seek to understand the mechanisms (e.g., non‐consumptive effects) driving individual variability in predator effects on ecosystem processes.

Perinatal exposure to titanium dioxide (TiO 2 ), as a foodborne particle, may influence the intestinal barrier function and the susceptibility to develop inflammatory bowel disease (IBD) later in life

Karst aquifers, like most hydrological systems, are sensitive to the influence of changes in land use as well as current and future climate change. To be able to identify the effects of these changes, in particular on the variability of groundwater flows, we have endeavored to produce one of the longest hourly spring discharge time series available for a French karst watershed. This reconstitution is based on a digitisation of the limnigraphic archives available for the Baget karst watershed. Correlation, spectral and multifractal analyses were then performed based on the spring discharge time series to confirm the multiscale nature of the hydrological response of this basin and to highlight the non-stationarity of this response.

<strong class="journal-contentHeaderColor">Abstract.</strong> Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are bacterial lipids that have been largely used as environmental proxies in continental paleorecords. Another group of related lipids, branched glycerol monoalkyl glycerol tetraethers (brGMGTs), has recently been proposed as a potential paleotemperature proxy. Nevertheless, the sources and environmental dependencies of both brGDGTs and brGMGTs along the river-sea continuum are still poorly understood, complicating their application as paleoenvironmental proxies in aquatic settings. In this study, the sources of brGDGTs and brGMGTs and the potential factors controlling their distributions are explored across the Seine River basin (NW France), which encompasses the freshwater to seawater continuum. To this aim, brGDGTs and brGMGTs were analyzed in soils, Suspended Particulate Matter (SPM) and sediments (<em>n</em>=237) collected all along this basin, from land to sea. Both types of compounds are shown to be produced <em>in situ</em>, in freshwater as well as saltwater. Redundancy analysis further shows that both salinity and nitrogen loadings dominantly control the brGDGT distributions. Furthermore, the relative abundance of 6-methyl <em>vs</em>. 5-methyl brGDGTs (IR_6Me ratio), Total Nitrogen (TN), &delta;¹⁵N and chlorophyll <em>a</em> concentration co-vary in a specific zone with low salinity, suggesting that 6-methyl brGDGTs are preferentially produced under low-salinity and high-productivity conditions. In contrast with brGDGTs, brGMGT distribution appears to be primarily regulated by salinity, with a distinct influence on the individual homologues. Salinity is positively correlated with homologues H1020a and H1020b, and negatively correlated with compounds H1020c and H1034b. This suggests that bacteria thriving in freshwater preferentially produce compounds H1020c and H1034b, whereas bacteria primarily growing in saltwater appear to be predominantly responsible for the production of homologues H1020a and H1020b. Based on the abundance ratio of the freshwater-derived compounds (H1020c and H1034b) <em>vs.</em> saltwater-derived homologues (H1020a and H1020b), a novel proxy, Riverine IndeX (RIX) is proposed to trace riverine organic matter inputs, with high values (&gt;0.5) indicating higher riverine contribution. RIX was then applied to the Godavari River basin (India) and a paleorecord across the upper Paleocene and lower Eocene, showing its potential applicability in both modern samples and in paleorecords.

Measuring trace element concentrations in tissue can be a valuable approach to monitor animal health status. Temporal variation in the absorption, transport, and storage of elements between different tissues can, however, complicate the assessment of element-health relationships. Here, we measured concentrations of selected essential (copper (Cu), zinc (Zn), selenium (Se)) and non-essential (arsenic (As), cadmium (Cd), lead (Pb)) trace elements within blood, liver, kidney, and hair of fallow deer (Dama dama; N=20) and red deer (Cervus elaphus; N=21). Using multivariate regression and structural equation models, we estimated direct and indirect linkages between tissue-specific trace element profiles and long- (body condition) and short-term (serum protein biomarkers for acute inflammation, infection, and malnutrition) health indicators. Trace element concentrations varied markedly and were weakly correlated among tissues, with the exception of Se. After accounting for sex- and site-differences in trace element concentrations, body condition of red deer was directly, and positively, associated to trace element status in liver and hair, but not in kidney. For both deer species, trace element status in blood was directly linked to serum protein status with an indirect positive association to deer body condition. For fallow deer, no direct association between trace element status and body condition was detected in any of the tissues, possibly because of elemental homeostasis, and because all individuals were in good clinical health. This study shows that hair can serve as an effective, non-invasive, biomarker in deer health assessments, yet, to fully uncover trace element-health relationships a variety of sample matrices is preferred.