9 research outputs found
Global compilation of Rare Earth Element concentrations in biological, sediment and water samples from 1973 to 2023
No full textOver the past 30 years, the significant increasing exploitation of Rare Earth Elements (REEs) for their use in new technologies (e.g. low-carbon energy, multimedia, medicine) has led to their release into the environment. The occurrence of these emerging contaminants in the environment leads to major health and environmental issues. In the last decade, a growing number of studies have observed the presence of anthropogenic REEs in freshwater and marine aquatic organisms. However, limited information is currently available regarding the natural levels of REE concentrations in aquatic organisms. A global understanding of these natural levels is therefore essential to: i) understand the natural biogeochemical cycles of REEs; ii) gain better insights into the risks of exposure associated with anthropogenic REEs; and iii) determine research perspectives by evaluating current knowledge gaps.
This dataset compiles concentrations for the 14 stable REEs, from lanthanum (La) to lutetium (Lu), and sum of REE concentrations (∑REE). These data were compiled from 102 articles published over the last 50 years, between April 1973 and January 2023. These articles provided at least one concentration value for one REE in one aquatic organism, regardless of the analyzed tissue (e.g. whole organism, leaf, liver, shell). A total of 15,710 concentration data were compiled for aquatic organisms. The REE concentrations were compiled for in situ aquatic organisms (expressed in µg.kg-1). The available concentration data for water (n=2105; in µg.l-1) and sediment samples (n=1125; in µg.kg-1) from these studies were also compiled. These field data span across a global scale, encompassing both freshwater and marine ecosystems.
The REE concentrations were associated with various biological parameters (e.g. Phylum, Species, Habitat, Tissues) and spatial parameters (e.g. Ecosystem, Area). For each of these parameters, the most precise information was obtained from the published articles providing these data. Additionally, the data were classified based on the presence or absence of environmental REE contamination at the sampling site. Further complementary information is available in the dataset (ReadMe tab). The reference for each of the cited articles is also provided in the dataset (References tab)
Inputs, dynamics and potential impacts of silver (Ag) from urban wastewater to a highly turbid estuary (SW France)
No full textInternational audienceAlthough silver (Ag) has been listed as a priority pollutant for the aquatic environment by the European Union (Directive 2006/11/EC), the use of Ag-based products with antimicrobial effects is increasing in Europe, as well as North America and Asia. This study investigates personal care products (PCP) as a potential source of Ag in wastewater, as well as the dynamics and fate of Ag in the influent and effluent of a major urban wastewater treatment plant (WWTP) located on the fluvial part of the Gironde Estuary. Typical household PCPs marked as using Ag contained concentrations of up to 0.4 mg kg−1 making them likely contributors to urban Ag released into the aquatic environment. Silver concentrations in influent wastewater generally occurred during mid-week working hours and decreased during the night and on weekends clearly indicating the dominance of urban sources. Up to 90% of the total Ag in wastewater was bound to particles and efficiently (>80%) removed by the treatment process, whereas 20% of Ag was released into the fluvial estuary. Silver concentrations in wastewater effluents clearly exceeded estuarine concentrations and may strongly amplify the local Ag concentrations and fluxes, especially during summer rainstorms in low river discharge conditions. Further work should focus on environmental effects and fate of urban Ag release due to immediate localized outfall and/or the adsorption on estuarine particles and subsequent release as dissolved Ag chloro-complexes within the estuarine salinity gradien
Spatial distribution of trace elements in the soils of south-western France and identification of natural and anthropogenic sources
No full textInternational audienceThe contamination of soils by trace elements is a major concern for soil quality. This study is based on the analysis of 356 samples from the RMQS soil monitoring network to establish the spatial distribution and origin of six trace elements (As, Cd, Cu, Cr, Ni, Pb) in soils of south-western region of France (area of 90,293 km2). An exploratory and multivariate statistical analysis, and geostatistics combined with a geographic information system (GIS) were used to identify and characterize any concentration anomalies in trace elements. For all the trace elements studied, the exploratory analysis shows that there are more anomalies in this region than in the rest of the country. Analysis of the semivariograms shows that the six elements are spatially auto correlated. The spatial structure of As highlights anisotropic behaviour with a direction that corresponds to the gold deposit and mining activities of the region. This indicates a dual origin anthropogenic and geogenic for As. The correlation between Cd and inherent features of calcareous soil (pH, CaCO3 and cation exchange capacity) suggest a mainly geogenic origin for this element; Cd origin is confirmed by its spatial distribution associated with the Jurassic limestone bedrock. The correlations between Cr, Ni and clays highlight a geogenic origin for these elements, as weathered parent material rich in clays is also rich in Cr and Ni. The high Cu concentrations are of anthropogenic origin, linked to viticulture and the spreading of Bordeaux mixture as a fungicide. Locally high Pb concentrations are associated with mining activities and automobile emissions in large cities in the region
Contributions and potential impacts of seven priority substances (As, Cd, Cu, Cr, Ni, Pb, and Zn) to a major European Estuary (Gironde Estuary, France) from urban wastewater
No full textInternational audienceUrban wastewater metal inputs into coastal systems are of increasing interest to both scientists and managers facing restrictive environmental protection policies, population increase and changing metal applications. However, their impact and contribution to metal loads in estuarine and coastal environments is widely unknown due to the lack of (i) monitoring in both artificial and natural aquatic systems and (ii) an understanding of control parameters, such as spatial and temporal variations in hydrological conditions. We investigated the daily concentrations, fluxes and dynamics of seven EU priority contaminants (potentially toxic metals Cd, Cu, Cr, Ni, Pb, Zn and the metalloid As) transported by the Garonne River (La Réole site; watershed area ~ 57,000 km2) to those released into the freshwater reaches of the Gironde Estuary (Garonne Branch) by two main wastewater treatment plants (WWTPs) of Bordeaux under low river discharge and contrasting rainfall situations. During short intense summer rainstorms, wastewater flow into the WWTPs increased by up to 150% and 60%, respectively, resulting in an increase of 70% (As) to 200% (Pb) for fluxes entering the treatment plants. Overall resulting WWTP particulate and dissolved effluent concentrations were up to 2 (Cr), 3 (Pb, Cu and Ni) and 5 (Cd and Zn) times higher than measured upstream in the Garonne River, respectively. During low-discharge, maximum outlet fluxes at the WWTPs were similar to respective watershed-derived fluxes in the Garonne River. During rain events, Pb in all fractions, total and dissolved Cu and total and particulate Zn fluxes entering the fluvial estuary were close to the respective minimum flux values at the La Réole site. Furthermore, during rain episodes, particulate Cu and dissolved Zn fluxes from the WWTPs to the fluvial estuary were greater than those transported by the Garonne River at the La Réole site. Mixing of treated wastewater with highly turbid estuarine freshwater most likely results in a re-equilibration between the dissolved and particulate phases, although biogeochemical processes in downstream estuarine turbidity and salinity gradients may partly reverse contaminant adsorption on estuarine particles. Accordingly, urban wastewater contaminant release clearly impacts estuarine water quality before being expulsed to the Bay of Biscay
Hormonal and genetic modulation of memory processes in healthy humans: focus on cortisol and "HDAC5"
No full textIndividual differences in memory performance can be due to the influence of various hormones as well as genetic variations and epigenetic modifications. These complex molecular and genetic mechanisms can impact learning, memory consolidation and retrieval differentially. This thesis deals with the modulation of memory processes in healthy human subjects focusing on two viewpoints. Firstly, by addressing the influence of the stress hormone cortisol, as evidence from animal and human studies shows that cortisol can enhance memory consolidation and impair retrieval. Secondly, by analyzing genetic and epigenetic data to find a target associated with synaptic plasticity and memory formation.
To investigate if stress, induced by the cold pressor test, affects memory processes, a fear-conditioning paradigm was used. The stress group showed an increase in the cortisol level and reduced retrieval of the conditioned fear memory. In a further study, we investigated if inter-individual changes in basal cortisol levels affect episodic memory. Results showed an association between stronger decreases in cortisol levels during retrieval and a better recall performance.
In a large genetic study we focused on genetic polymorphisms tagging histone deacetylase 5 (HDAC5), a gene associated with synaptic plasticity and memory formation in animal models. We detected significant associations between these polymorphisms and episodic memory performance, especially for emotional information. Surprisingly, these polymorphisms were strongly associated with expression levels of a transcript in the vicinity of HDAC5.
These results may have implications for the understanding of the mechanisms underlying memory formation in healthy subjects and the interpretation of genetic data. Additionally, our results may have clinical implications for different neuropsychiatric disorders, such as depression, anxiety disorders or posttraumatic stress disorder, for which learning and memory play an important role
The X-ray Integral Field Unit at the end of the Athena reformulation phase
No full textInternational audienceThe Athena mission entered a redefinition phase in July 2022, driven by the imperative to reduce the mission cost at completion for the European Space Agency below an acceptable target, while maintaining the flagship nature of its science return. This notably called for a complete redesign of the X-ray Integral Field Unit (X-IFU) cryogenic architecture towards a simpler active cooling chain. Passive cooling via successive radiative panels at spacecraft level is now used to provide a 50 K thermal environment to an X-IFU owned cryostat. 4.5 K cooling is achieved via a single remote active cryocooler unit, while a multi-stage Adiabatic Demagnetization Refrigerator ensures heat lift down to the 50 mK required by the detectors. Amidst these changes, the core concept of the readout chain remains robust, employing Transition Edge Sensor microcalorimeters and a SQUID-based Time-Division Multiplexing scheme. Noteworthy is the introduction of a slower pixel. This enables an increase in the multiplexing factor (from 34 to 48) without compromising the instrument energy resolution, hence keeping significant system margins to the new 4 eV resolution requirement. This allows reducing the number of channels by more than a factor two, and thus the resource demands on the system, while keeping a 4' field of view (compared to 5' before). In this article, we will give an overview of this new architecture, before detailing its anticipated performances. Finally, we will present the new X-IFU schedule, with its short term focus on demonstration activities towards a mission adoption in early 2027
The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase
No full textThe Athena X-ray Integral Unit (X-IFU) is the high resolution X-ray
spectrometer, studied since 2015 for flying in the mid-30s on the Athena space
X-ray Observatory, a versatile observatory designed to address the Hot and
Energetic Universe science theme, selected in November 2013 by the Survey
Science Committee. Based on a large format array of Transition Edge Sensors
(TES), it aims to provide spatially resolved X-ray spectroscopy, with a
spectral resolution of 2.5 eV (up to 7 keV) over an hexagonal field of view of
5 arc minutes (equivalent diameter). The X-IFU entered its System Requirement
Review (SRR) in June 2022, at about the same time when ESA called for an
overall X-IFU redesign (including the X-IFU cryostat and the cooling chain),
due to an unanticipated cost overrun of Athena. In this paper, after
illustrating the breakthrough capabilities of the X-IFU, we describe the
instrument as presented at its SRR, browsing through all the subsystems and
associated requirements. We then show the instrument budgets, with a particular
emphasis on the anticipated budgets of some of its key performance parameters.
Finally we briefly discuss on the ongoing key technology demonstration
activities, the calibration and the activities foreseen in the X-IFU Instrument
Science Center, and touch on communication and outreach activities, the
consortium organisation, and finally on the life cycle assessment of X-IFU
aiming at minimising the environmental footprint, associated with the
development of the instrument. Thanks to the studies conducted so far on X-IFU,
it is expected that along the design-to-cost exercise requested by ESA, the
X-IFU will maintain flagship capabilities in spatially resolved high resolution
X-ray spectroscopy, enabling most of the original X-IFU related scientific
objectives of the Athena mission to be retained. (abridged).Comment: 48 pages, 29 figures, Accepted for publication in Experimental
Astronomy with minor editin
The X-ray Integral Field Unit at the end of the Athena reformulation phase
No full textThe Athena mission entered a redefinition phase in July 2022, driven by the imperative to reduce the mission cost at completion for the European Space Agency below an acceptable target, while maintaining the flagship nature of its science return. This notably called for a complete redesign of the X-ray Integral Field Unit (X-IFU) cryogenic architecture towards a simpler active cooling chain. Passive cooling via successive radiative panels at spacecraft level is now used to provide a 50 K thermal environment to an X-IFU owned cryostat. 4.5 K cooling is achieved via a single remote active cryocooler unit, while a multi-stage Adiabatic Demagnetization Refrigerator ensures heat lift down to the 50 mK required by the detectors. Amidst these changes, the core concept of the readout chain remains robust, employing Transition Edge Sensor microcalorimeters and a SQUID-based Time-Division Multiplexing scheme. Noteworthy is the introduction of a slower pixel. This enables an increase in the multiplexing factor (from 34 to 48) without compromising the instrument energy resolution, hence keeping significant system margins to the new 4 eV resolution requirement. This allows reducing the number of channels by more than a factor two, and thus the resource demands on the system, while keeping a 4’ field of view (compared to 5’ before). In this article, we will give an overview of this new architecture, before detailing its anticipated performances. Finally, we will present the new X-IFU schedule, with its short term focus on demonstration activities towards a mission adoption in early 2027we would like to re-express our gratitude to the lead funding agencies supporting X-IFU for their unfailing and vigorous support, at a time when the future of the mission was not secured, and from now on, towards the goal of adopting NewAthena in 2027. The Italian contribution to XIFU is supported by ASI (Italian Space Agency) through Contract No. 2019- 27-HH.0. The X-IFU consortium members working at Instituto de Física de Cantabria acknowledge Grant PID2021_122955OB-C41 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”https://link.springer.com/article/10.1007/s10686-025-09984-
