Search

Among other parameters, volcanic activity adjacent to shallow marine environments influences the development of ecosystems and their carbonate-producing communities. Volcaniclastic sediment influx in particular has potential to cause rapid and drastic environmental changes affecting biological systems in their composition and activity, and ultimately leading to changes to and breaks in carbonate sedimentation. Such sedimentary breaks that form in response to volcanic processes are rarely described in detail despite the common occurrence of carbonate platforms adjacent to active volcanoes both in the recent and past geological record. The Island of St. Bartholomew (St. Barths), French West Indies, exposes sections of middle Eocene limestones intercalated with thick volcaniclastic deposits and lavas. Theses carbonates provide an example of a low-latitude tropical platform where non-framework building biota were important, if not dominant, sediment contributors. The carbonate system records the repeated collapse and renewal of carbonate production, as a result of episodic volcaniclastic material input. The discontinuous nature of the carbonate sedimentation is reflected in contrasted depositional systems across sedimentary surfaces and gradational contacts. The studied Eocene deposits provide a sedimentary record of how volcanic events impacted warm-water carbonate factories, both in their disturbance, demise and recovery.

International audience; This paper presents a flexible and wearable (on-body) dual band antenna operating in two Industrial, Scientific and Medical (ISM) frequency bands. The central frequencies selected are equal to 2.45 GHz and 5.8 GHz. In order to make the antenna suitable for Wireless Body Area Network (WBAN) applications, it is fabricated on a flexible biopolymer called cellulose laurate (CL). The proposed antenna, that has been designed and optimized on ANSYS HFSS, is realized using a process based on copper adhesive tape and laser structuring. The characterization of the antenna in terms of reflection coefficient, gain and radiation patterns shows a good agreement with the simulation data. Compared to state-of-the-art antennas, the investigated solution demonstrates competitive results. The proposed antenna also features stable performance under bending conditions and the estimated specific absorption rate (SAR) is well below the limits defined by international standards. All these results suggest that the proposed antenna is very well suited for potential wearable applications and is a step towards fully green electronics.

The purpose of this study is to obtain ionically cross-linked gellan particles containing immobilized yeast cells. The zinc acetate was chosen as a cross-linking agent due to its beneficial role in the growth and nutrition of yeast cells and also due to the advantages of its use in fermentation processes. The physicochemical and morphological properties as well as the fermentative activity of the obtained particles were studied. The zinc acetate concentration has an influence on particles stability in water, on the mechanical stability and also on the swelling degree. The morphology of the obtained particles was analyzed by SEM and proves that the yeast cells are immobilized in large numbers in the polymeric matrix. The cell viability is maintained at high values after several fermentation cycles. These obtained micro-bioreactors were tested in terms of fermentative activity and the fermentation process was optimized by studying the influence of several factors. The gellan gum particles can be easily recovered by filtration and they can be reused in repeated fermentation cycles. The results obtained in the presence of these cross-linked particles are comparable to those achieved in the free yeast fermentation.

International audience; The photocatalytic removal of Flumequine (antibiotic) using a luminous textile which served as a support for the TiO2 and a light transmitter through optical fibers was examined in this study. Two configurations of luminous textile were investigated (Mono-Face and Double-Face) in terms of compounds degradation and mineralization. Photocatalytic performances of Double-Face configuration were found to be better than the one obtained with Mono-Face. Furthermore, to describe the kinetics of the reaction, the Langmuir-Hinshelwood model was successfully applied and both reaction kinetic and adsorption/desorption equilibrium constants were determined. Double-Face configuration also showed better performances compared to the conventional process in the different water matrices tested (ultrapure water, synthetic solution simulating seawater and synthetic hospital wastewater). This configuration was tested for cetirizine (antihistamine) degradation as well, with a satisfying result obtained. Moreover, this technology showed good stability and reusability. On the other hand, the larger size of Double-Face retained its performance at pilot-scale. Finally, the irradiation analyzes showed a good light distribution homogeneity on the textile surface at both laboratory-scale and pilot-scale.

Graphical abstract Scheme 1. Representation of enzymatic transformation of carbohydrates into glycolipids and the formation of biosurfactants in heterogenous medium., Highlights • This review summarizes most recent works on biocatalytic synthesis of glycolipids. • Main parameters affecting enzymatic synthesis of amphiphilic carbohydrates. • The outlined information embraces the development of green biosynthetic techniques., Glycolipids, carbohydrate fatty esters or sugar esters are amphiphilic molecules containing hydrophilic groups bonded to hydrophobic parent structures. Recently, glycolipids have shown their antimicrobial and antitumor capacities. Their surface activity properties have applications in the food, pharmaceutical and cosmetic industries. Sugar esters’ building blocks can be obtained from natural resources and/or be transformed by biochemical pathways for uses as surfactants. Biosurfactants are non-ionic, nontoxic, biodegradable, tasteless, and odourless. The biocatalysis of these molecules involves sustainable, green, and safer methods. The advantages of producing biosurfactants from enzymatic catalysis are the energy economy, high selectivity, production of natural products, reduction of the use of fossil-based solvents and chloride compounds. This review presents the most recent studies concerning the evaluation of the impact of the main parameters and their levels influencing the enzymatic synthesis of glycolipids. Various enzyme catalysed synthetic methods were described. The parameters studied were temperature, reaction time, solvent system, type of biocatalyst, substrates molar ratio proportion and the nature of substrates. This review discusses the influence of different biocatalysts in the conversions of glycolipids; The reactivity from mono to polysaccharides and their interaction with fatty acids of different carbon chain lengths in the presence of specific enzymes; The effect of the solvent polarity, the use of multiple solvents, ionic liquids, supercritical CO2, and solvent-free media in sugar ester conversions; And the optimization of temperature and reaction time in different enzymatic systems.

International audience; This study deals with photocatalytic application for indoor air pollution remediation. Two target compounds were selected: Butane-2,3-dione (C4H6O2) and Heptan-2-one (C7H14O). Escherichia coli (E. coli) were used as bacteria strain. Photocatalytic removal of VOCs alone, E. coli alone and their mixture (VOCs/E. coli) were evaluated, at pilot scale. Indeed, a series of experiments were carried out in a continuous planar reactor using a novel photocatalyst/TiO2 technology with metal wires e.g. Copper (Cu)/Silver (Ag)-woven in optical fiber. Effects of experimental conditions such as flow rate (2–12 m3.h−1), VOCs inlet concentration (5–20 mg.m−3) and humidity levels (5–70%) on removal efficiency were investigated to properly appraise the oxidation performance in real conditions. All textile fiber photo-catalysts (TiO2, TiO2-Cu and TiO2-Ag) showed good photocatalytic activities towards C4H6O2/C7H14O removal. As for simultaneous application with VOCs and E. coli: (i) in terms of VOCs removal efficiency, the same trend of performance was observed compared to VOCs experiments alone: 63% of removal efficiency by TiO2 alone, 46% by TiO2-Ag and 52% by TiO2-Cu, (ii) in terms of E. coli inactivation, only experiments with TiO2-Cu and TiO2-Ag revealed a good performance

In order to make concrete construction greener, new High Range Water Reducing Admixtures (HRWRAs) from natural origin-should be developed. Some natural polysaccharides and their derivates have interesting properties which explain their growing use in the field of materials. Their use is not only linked to the biodegradable and atoxic aspect but is also linked to the fact that they can confer new properties to cement-based materials. In the presented study, starch has been chosen as main polysaccharide chain. Starch has first been used without any modification, and then with different grafted substituents like acetate, maleate, succinate, sulfonate to mimic the structure of petrochemical HRWRAs. Some tests have been done to evaluate the potential effect of these biobased derivatives as new HRWRAs. Some of the starch-based polymers were also evaluated in a commercial self-leveling compound. Results show that a graft of sulfopropyle or sulfobutyle side chains on a starch polymer can lead to slump flows on grouts comparable with the ones obtained on PolyNaphtalene Sulfonate (PNS) based grouts, and also that starch-sulfobutyle or starch-maleate can potentially replace casein in self-leveling compounds.

6-Azido-6-deoxy- d -galactitol and d -mannitol were obtained quantitatively via the reduction of the corresponding 6-azido-6-deoxy- d -hexono-1,4-lactones, and 6-azido-6-deoxy- d -glucitol was obtained by the reduction of 6-azido-6-deoxyglucose in good yields. The reduction of monoazidodeoxyhexitols by catalytic hydrogenation gave the monoaminohexitol analogues in 95–98% yields. Oxidation of these afforded the corresponding 6-amino-6-deoxy- d -aldonic acids in moderate yields. Alternatively, saponification of 6-azido-6-deoxy- d -hexonolactones gave 6-azido-6-deoxyaldonic acid salts which, after reduction followed by neutralization, led to the expected compounds in 82–88% overall yields.

Resume Position du probleme La question des biais constitue un enjeu methodologique central pour l’epidemiologie. Cependant, l’histoire de ce concept n’a fait l’objet que de rares etudes. De plus, la definition classique du biais comme deviation systematique des resultats ou des inferences par rapport a la verite, telle qu’elle peut apparaitre dans les dictionnaires d’epidemiologie, ne semble correspondre ni a la maniere dont les epidemiologistes l’utilisent en pratique, ni aux differentes definitions qui jalonnent l’histoire de l’epidemiologie. Il s’agit donc d’expliquer ce paradoxe. Methodes Cet article historique et epistemologique propose d’analyser, depuis les articles classiques des annees 1950 sur le lien entre tabagisme et cancer du poumon jusqu’aux manuels d’epidemiologie les plus recents, les diverses occurrences du mot « biais » ainsi que la maniere dont les epidemiologistes utilisent, definissent et rectifient ce concept au fil du temps. Resultats Nous montrons que l’article de D.L. Sackett de 1979, consacre aux biais dans la recherche etiologique, vient clore, au moins provisoirement, une reflexion amorcee trente annees auparavant en epidemiologie populationnelle. Plus precisement, nous montrons que la definition donnee par Sackett du biais se construit moins en relation avec les besoins et les buts de l’epidemiologie populationnelle que de ceux de l’epidemiologie clinique. Au meme moment, le concept de biais est redefini au sein de l’epidemiologie populationnelle, notamment par K.J. Rohtman, comme une menace a la validite interne d’une etude, dans le cadre d’une redefinition de l’etude epidemiologique comme exercice de mesure. Conclusion Ainsi, il convient de distinguer entre deux concepts de biais : un concept epidemiologique de biais, concu comme un defaut de validite interne d’une etude observationnelle ; et un concept medical de biais, concu comme un ecart par rapport a la verite. Le premier porte sur le plan et la methodologie des etudes epidemiologiques ; le second est plus general et invite les epidemiologistes et les medecins a une certaine forme de scepticisme, voire de criticisme, envers leurs propres inferences.

Biosorbent materials represent an interesting alternative to classic methods of metal removal from industrial effluents. Acacia biomass showed a higher absorption capacity for heavy metals than living biomass. This study aimed to evaluate the bioadsorption of Lead and Cadmium onto Acacia Gummifera gum, using batch experiment. The structural characterization of the biosorbent was carried out using FT-IR, SEM, BET, TGA and DSC analysis. The adsorption equilibrium was reached within 15 min. A maximum uptake of 18.3 mg.g−1 Pb2+ and 9.57 mg.g−1 Cd2+ was achieved at pH 6.5. The metal ions seemed to be removed exclusively by ion exchange, physical sorption and chelation. The biomass of A. Gummifera powder was found to be effective for lead and cadmium removal with respectively 97% and 86% sorption efficiency at a concentration of 100 mg/L, in aqueous media. Parameters affecting adsorption capacities such as biosorbent dosage, initial metal concentration, temperature, and pH are discussed in detail. Furthermore, adsorption thermodynamics, kinetics, and equilibrium were studied and fitted by different models. Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherms were used to compare adsorption data at equilibrium. The adsorption kinetics data were found to be best fitted by the pseudo-second-order model, and the adsorption isotherm was well fitted with the Langmuir model. The calculated thermodynamic parameters (ΔG0, ΔS0 and ΔH0) indicated a spontaneous and exothermic biosorption of both metal ions onto Acacia Gummifera. Moreover, chromatograms obtained by size exclusion chromatography coupled with multi-angle laser light scattering detection system (SECMALLS) showed the formation of complexes between the arabinogalactan-peptide (AGP) and glycoprotein (GP) Acacia moieties and the two studied metal ions. The analysis of the FTIR spectra of dried Acacia and that of Acacia loaded with lead and cadmium in aqueous media suggests that the surface functional groups such as amides and carboxy groups might be involved in the metal removal process. The extent of adsorption for both metals increased along with an increase of the A. Gummifera biomass dosage. A. Gummifera biomass, which is safe, of low-cost, and highly selective, seems therefore to be a promising substrate for simultaneous trapping of Pd and Cd ions in aqueous solutions.

International audience; Three cubic-meters of CO2-saturated water was injected into a subsurface fractured aquifer in a post-mined area, using a push-pull test protocol. Groundwater samples were collected before and after CO2-injection to quantify geochemical changes. CO2-injection initially reduced the pH of water from 7.3 to 5.7, led to the enrichment of major ions (Ca2+, Mg2+, and alkalinity), and dissolved trace metals (including Fe, Mn, As, and Zn) in the groundwater. Rare earth elements (REE) and yttrium concentrations were also measured in these samples before and after CO2 perturbation, to evaluate their behavior. An enrichment of total Y plus REE (REY) occurred. REY fractionation was observed with higher heavy REE (HREE) enrichment compared to light REE (LREE), and significant variations in La/Yb and Y/Ho ratios were observed following CO2 perturbation. Enrichment by a factor of three was observed for Y, Lu, and Tm, and by nearly one order of magnitude for Dy and Yb. A geochemical model was used to evaluate the amount of REE aqueous ions complexed throughout the experiment. Modeling of the results showed that speciation of dissolved REE with carbonate, along with desorption from iron oxyhydroxide surface were the main factors controlling REE behavior. This study increases an understanding of dissolved REE behavior in the environment, and the potential use for applying iron oxides for REE recovery from mine drainages. Furthermore, the description of REE fractionation patterns may assist in surveying CO2 geological storage sites, surveying underground waste disposal sites, and for understanding the formation of ore deposits and fluid inclusions in geological formations.

International audience; Sewage sludge is a phosphorus (P) source alternative to P fertiliser derived from rock phosphate, but its impact on soil processes driving P cycling in agroecosystems requires further study. In order to optimise the use of sludge for sustainable P fertilisation, we need to elucidate the drivers of P dynamics. The present study aims at determining how different sludges (heated sludge, HS and composted sludge, CS) affect soil P pools and dynamics. A field experiment was established and soil was amended either with sludge or with inorganic P (triple superphosphate, TSP). Soil samples were collected five times during a vegetation period, and analysed for Hedley P fractions, microbial P and phosphatase activity. Phosphorus dynamics in soil was strongly influenced by P concentrations in sludge. About one year after application, sludge with the highest P concentration (HS) was as effective as TSP to improve soil P availability. The P source of TSP was immediately available for plant uptake, but the high phosphatase activity of the HS treatment evidenced that soil microorganisms released phosphatases which can hydrolyse HS-derived organic P compounds. In addition, the high content of microbial P in the HS treatment suggests that soil microorganisms assimilate P into their own biomass. By contrast, sludge with the lowest P concentration (CS) enriched primarily the weakly-soluble soil P fractions, resulting in lower P availability compared with that in the TSP treatment. Our findings suggest that both high P concentration and slow, but continuous microbial breakdown of organic P substrates derived from HS allow using this resource as an important source for plant mineral nutrition. This study stresses the need to both characterise P concentrations and P forms in sludge, prior to their application in the field.

In order to replace wood in particleboard manufacturing, two agricultural by-products were studied: the flax shives and the sunflower bark, which are abundant, renewable and little valorized raw materials. Sunflower bark in particular is very few studied. This study will demonstrate the possibility of using sunflower bark in particleboards and how to modulate the manufacturing process to take the benefits of both studied agroresources. These plant based particles present interesting porous structures for using as materials for building insulation or as furniture. To obtain totally biosourced materials, the plant based particles were self-bound by a thermocompression process with water. The properties of these materials were compared with particleboards made of the same plant based particles with a classical urea-formaldehyde binder. Particleboards of two target densities are compared: 350 and 500 kg m−3. Both agroresource materials do not present the same behavior to self-binding or classical binding. Flax shives are more adapted to self-binding process thanks to their biochemical composition and their morphological structure. These different boards were characterized according to mechanical and thermal properties, resistance to water and to fire. The type of agroresource or of binder does not influence the thermal conductivity. The denser binderless boards show better resistance to fire. The main defect of binderless boards is their too low resistance to water compared to boards made with a synthetic binder.

International audience; Ecological engineering of degraded ecosystems often manipulates plants, with positive outcomes for their restoration or ecosystem services production. The importance of soil biota for successional plant communities has prompted consideration of direct inoculation (active) or attraction (passive) of soil organisms as a relevant restoration strategy. However, few attempts have manipulated soil invertebrates as part of nature based solutions for ecosystem restoration, despite their major role in many soil ecological processes and in plant-soil feedback processes. In addition, while ecological restoration and ecological engineering approaches successfully incorporate plant traits, soil invertebrate traits remain underused. Exploiting the functional diversity of soil communities by adopting a trait-based approach could enhance restoration of soil chemical, biological and physical properties. Here, we conduct a narrative review and identify a set of soil invertebrate functional traits with great potential in ecosystem restoration. We focus on traits related to four main ecological functions that are often at the core of restoration plans: nutrient cycling and carbon cycling, pollutant detoxification, soil structure arrangement, and biological control agent by prey/pest regulation. This paper further proposes guidelines for stakeholders that need to be addressed to successfully integrate soil organism traits into ecological engineering. Finally, we highlight main knowledge gaps and limitations currently impeding the use of soil invertebrate traits in ecological engineering, and identify avenues for future research. We especially bring out (i) that few studies still use soil invertebrates in restoration, so even fewer are based on traits, (ii) a lack of data about soil invertebrate species role in ecosystems, (iii) a lack of data about attributes from specific traits and groups in existing soil functional trait databases, (iv) the complex relationships between functions and traits and (v) that future studies are needed to demonstrate the benefits of such trait-based approaches compared to approaches relying on emblematic species.

International audience; Wheat grain storage proteins, i.e. the gluten proteins, and alpha-amylase trypsin inhibitors are partially resistant to gastrointestinal digestion. They figure among the wheat components that are potential triggers of non-celiac wheat sensitivity. To explore the digestibility of bread wheat proteins in relation to heritable plant traits, old and modern wheat varieties grown in two environments were genotyped, phenotyped, and processed into breads, which were partially digested in vitro in a system resembling human digestion. The extent of proteolysis measured after 2 h of digestion was variable. Digestion of proteins present in bread made from old wheat cultivars registered before 1960 and modern cultivars registered after 1960 was similar. No major plant trait was correlated to partial protein digestibility of bread from cultivars with high grain protein content. The protein digestibility of bread from high yield cultivars was influenced by protein composition, as well as the genetic distance per chromosome from a reference variety. Improving high yield cultivars by breeding for highly digestible proteins might help to mitigate adverse reactions to a range of wheat proteins in susceptible individuals.

International audience; Conventional, intensively managed coffee plantations are currently facing environmental challenges. The use of shade trees and the organic management of coffee crops are welcome alternatives, aiming to reduce synthetic inputs and restore soil biological balance. However, little is known about the impacts of the different types of shade tree species on soil functioning and fauna. In this paper, we assess soil nutrient availability and food web structure on a 17-year old experimental coffee plantation in Turrialba in Costa Rica. Three shade types (unshaded coffee, shaded with Terminalia amazonia, and shaded with Erythrina poepiggiana) combined with two management practices (organic and conventional) were evaluated. Total C and N, inorganic N and Olsen P content, soil pH, global soil fertility, and nematode and microarthropod communities were measured in the top 10 cm soil layer, with the objective of determining how shade tree species impact the soil food web and soil C, N and P cycling under different types of management. We noted a decrease in soil inorganic N content and nematode density under conventional management (respectively -47% and -91% compared to organic management), which suggested an important biological imbalance, possibly caused by the lack of organic amendment. Under conventional management, soil nutrient availability and fauna densities were higher under shade, regardless of the shade tree species. Under organic management, only soils under E. poeppigiana, a heavily pruned. N-2 -fixing species, had increased nutrient availability and fauna density, while T amazonia shade had a null or negative impact. The effects of coffee management and shade type on soil nutrient availability were mirrored by changes in soil food web structure. Higher fertility was recorded in soil with balanced food webs. These results emphasize the importance of the choice of shade tree species for soil functions in low input systems, more so than in fertilized systems

International audience

International audience; Vegetation controls concentrated runoff and erosion in the European loess belt by increasing hydraulic roughness and sediment retention. Studies of plant effects on runoff velocity are usually based on a taxonomical characterisation and do not consider the effects of aboveground plant functional traits in attempts to understand soil erosion by water. This trait-based plant study investigates aboveground plant functional trait effects of herbaceous hedges on the hydraulic roughness to understand soil erosion. Eight aboveground morphological traits were measured on fourteen indigenous and perennial plant species (caespitose or comprising dry biomass in winter) from north-west Europe with a high morphological variability. For each trait, density-weighted traits were calculated. The effects of traits and density-weighted traits were examined using a runoff simulator with four discharges. The leaf density and area, as well as density-weighted stem and leaf areas, stem diameter and specific leaf area were positively correlated with the hydraulic roughness. Generalised linear models defined the best combinations of traits and density-weighted traits: (1) leaf density and leaf area, (2) density-weighted leaf area and density-weighted projected stem area, and (3) density-weighted leaf area and density-weighted stem diameter. Moreover, the effects of leaf density, leaf area and density-weighted specific leaf area, varied depending on the discharge. This study is one of the first characterisation of aboveground trait effects on hydraulic roughness and highlights that vegetation with large stem density, diameter and leaf area plays a significant role in minimising soil erosion. The selection of plant species can derive from these plant trait effects to design reconstructed herbaceous hedges to minimise soil erosion.

Understanding management factors driving soil biota is pivotal to improve the sustainability of cropping systems, especially given the emergence of new cropping systems induced by bioeconomy. Here, we investigated the combined effects of tillage practices (tillage versus no-tillage) and contrasted cropping systems, including conventional, feed and biogas cropping systems, on earthworm communities and microbial metabolic activity and diversity (using Biolog Ecoplate). After three years, our results revealed that tillage overrode the effect of cropping systems on soil biota while being also detrimental for both earthworm communities and microbial activity and diversity compared with no-tillage. By contrast, no-tillage had generally a beneficial effect on soil microbial activity and earthworm abundance. More importantly, under no-tillage, feed and biogas systems increased microbial activity and diversity which was likely due to the higher crop diversity and the use of digestate instead of manure and slurry compared with the conventional system. Taken together, our findings show that both earthworm communities and microbial activity and diversity are very sensitive to tillage. Moreover, microbial activity and diversity are also rapidly affected by the type of cropping system, suggesting that it would be a better indicator to detect short-term changes in soil functioning following change in land use. Our study also indicates that, provided that no-tillage is included, biogas cropping system with high crop diversity can promote soil biota compared with conventional farming practices, leading likely to the improvement of soil functioning and ecosystem service delivery.

Achieving sustainability is a worldwide current concern in agriculture that brings important challenges but also opportunities for rethinking agroecosystems. While many studies focused on tillage effects upon soil organisms, few of them have considered this into a temporal framework. In a study conducted in actual field conditions, we evaluated at short-term (7 months) the dynamic of several abiotic and biotic soil parameters under contrasting tillage systems. We hypothesised that (1) the reduction and especially the stopping of the soil mechanical perturbation lead overall to an improvement of the soil physical structure and the food resources available for soil fauna. (2) According to their specific ecological requirements, Collembola and Earthworms will show different dynamics of responses following alleviation of soil mechanical perturbation. (3) For a single group (either Collembola or earthworms), differences between tillage systems are dependent on the sampling period. We used a field set-up held on the INRA experimental station of Estrees-Mons (North of France). Three tillage systems were investigated: conventional tillage (with the soil inverted up to 25 cm depth) reduced tillage (limited to the first 7–8 cm depth) and no-tillage. Each treatment was replicated 4 times randomly (3 × 4 = 12 plots in total). Collembola and earthworms were sampled at each plot using standard methods. During the course of the experiment, two tillage operations were performed one in mid-March and one in mid-May. Samplings of soil fauna were performed on a regular basis according to tillage operation: 1 day before, and respectively 1; 7; 30; 49; 56; 104; 210 days after. Abiotic parameters (bulk density, SOC stock, Mean Weight Diameter (MWD) and aggregates size) and microflora (microbial and fungal biomass and their activity) were also monitored and used as explaining factors. Our findings showed that slightly reducing the intensity of soil mechanical perturbation, did not favour soil fauna. But, when stopping tillage, population sizes of earthworm and Collembola increased. This is related to the improvement of the distribution of, and accessibility to, organic matter as a basic food source (SOC stock, microbial and fungal biomass and their potential C mineralisation activity), the physical structure of the soil and the distribution of pore sizes as a space life (bulk density, MWD and aggregates size). Our kinetic study has shown that the different groups of soil fauna respond differently to mechanical soil disturbance. Overall, conservation tillage can foster one of the numerous services provided by the soil compartment, namely the soil biodiversity and therefore improve soil quality and health.

Previous work have indicated a lipid-lowering effect of esterified astaxanthin (AX) from algae Haematococcus pluvialis . The aim of this study was to set up a murine model of pre-obesity diet-induced dyslipidaemia to investigate the lipid-lowering effect of free-form AX from yeast Phaffia rhodozyma fermentation. After 6 weeks on high-fat diet, 32 male C57BL/6 mice were divided into 4 groups fed (1) a standard or (2–4) a high-fat diet (HFD) supplemented or not with AX at 0.03% or 0.06% for 8 weeks. Animals were anesthetized and sacrificed and biological samples (plasma and internal organs) collected and stored at −80 °C. The plasma concentrations of triglycerides and cholesterol were determined and gene expression measured for markers of energy metabolism in the liver and adipose tissue. Statistical analyses were performed using SPSS software and the significance set at p

Rare earth elements (REE) are powerful tracers for our understanding of sedimentary provenance and depositional processes. This study investigated geochemical characteristics of REE in 226 sediment samples collected from the piedmont, central and littoral plains of the North China Plain. Results showed that total REE concentrations exhibited a decreasing trend as piedmont > central > littoral, and 82%, 70% and 67% samples had total REE concentrations higher than the value of upper continental crust. The REE concentrations were controlled by sedimentary provenance and sediment physicochemical properties. Ternary diagrams of sandstone classification and Al2O3–CaO + Na2O–K2O reflected that sediments originated from greywackes and they experienced an incipient to intermediate chemical weathering. Average chemical index of alteration (CIA) value was 68, 51 and 55 for sediments from piedmont, central and littoral plains, respectively. Sediment North American Shale Composite (NASC)-normalized patterns were characterized by light REE (LREE) enrichment over heavy REE (HREE) and coherent negative Eu anomaly (Eu/Eu* ranging between 0.57 and 1.00). Value of (La/Yb)NASC ranged from 0.86 to 1.15 (average 1.23), and from 1.03 to 1.49, and from 0.91 to 1.49 in three zones, respectively, indicating REE fractionation occurred from piedmont to littoral during sedimentation processes. A positive correlation between (La/Yb)NASC and total REE concentrations was observed in piedmont and central sediment samples, implying that LREE were preferentially enriched over HREE with an accumulation of REE. This positive correlation was not found in littoral sediment samples, where a general decreasing trend along depth for REE concentrations existed. The findings of this study have an implication for using REE as a tracer in provenance studies from a basin scale.

Lime hemp concrete (LHC) is one of the most environmentally friendly alternatives to traditional building materials, which is normally used as an insulation material. The lime hemp concrete is made up of hemp shiv and aerial (or hydraulic) lime and has the ability to offer better thermal and acoustic performances. However, it is reported that the shiv/matrix reaction does not always meet the expectations, thus the properties of hemp concrete may be affected by certain characteristics, such as origin, retting time, harvest time, etc. of the used hemp. During this work, the authors have studied the influence of variability of hemp shiv on the setting of LHC. The results depicted that the soluble components (e.g., organic acids, simple sugars, etc.) from hemp shiv had a significant impact on the setting and hardening of mortars. This study also proved that hemp containing more soluble components tends to involve a longer setting time and hinders long-term carbonation reaction of binders. Furthermore, the experimental results also showed that water treatment can effectively remove these soluble agents from hemp shiv and improve the compatibility between shiv and binder in the composite.

A high quality chocolate requires not only a shiny surface, a crunchy and pleasant texture, but also a proper resistance to blooming. All these characteristics are influenced by the physical and chemical properties of the components, which are directly related to their crystalline structure. Some works found that the proportion of cocoa butter (CB), cocoa butter equivalent (CBE) and milk fatty acid (AMF) tend to strongly delay the blooming when mixing them. The goal of our research is to determine how the choice of adding CBE to the mixture delays chocolate blooming. ESI/MALDI-HRMS, X-ray, DSC, MIR and Raman investigations were used to analyze the structure features and the vibrational modes of CB and CBE. The comparison of these experimental results between CB and CBE made it possible to highlight markers of differentiation between CB and CBE which seems to explain the impact of CBE in the chocolate blooming. Part of these triglycerides remains in form IV instead. The presence of the latter seems to be a key parameter that favors the transformation deceleration to the form VI, which is responsible for the fat bloom development.

International audience; Many questions about the soil pollution due to mining activities have been analyzed by numerous methods which help to evaluate the dispersion of the Metallic Trace Elements (MTE) in the soil and stream sediments of the abandoned mine of Kettara (Morocco). The transport of these MTE could have an important role in the degradation of groundwater and the health of people who are living in the vicinity. The present paper aims to evaluate the groundwater samples from 15 hydrogeological wells. This evaluation concerns the hydrogeological parameters, pH, Electrical conductivity, temperature and the groundwater level, and the geochemical assessment of Mg, Ca, Ti, Cr, Mn, Fe, Co, Ni, Zn, Cu, As, Se, Cd, Sb, Tl and Pb. Furthermore, the Metallic Trace Elements are transported in the saturated zone via the fractures network. The groundwater flow is from the north-east to south-west. The spatial distribution of As, Fe, Zn and Mn is very heterogeneous, with high values observed in the north, upstream, of the mine site. This distribution is maybe related to: i) the existence of hydrogeological structures (dividing and drainage axes); ii) the individualization of the fractures network that affects the shaly lithostratigraphical formation; iii) the transport of the contaminants from the soil towards groundwater; and iv) interaction water/rocks. Some MTE anomalies are linked to the lithology and the fracturation system of the area. Therefore, the groundwater contamination by Arsenic is detected in the hydrogeological wells (E1 and E2). This pollution which is higher than guideline standards of Moroccan drinking water could affect the public health. The hydrogeological and geochemical investigations favor the geological origin (mafic rocks) of this contamination rather than mining activities.

International audience; Zinc is an essential micronutrient that is ultimately released during mineral weathering. In soils, organic matter plays a key role in influencing Zn partitioning and therefore on Zn biogeochemical cycling. Soil organic matter is partitioned between carbon that is more readily available for decomposition by microorganisms, and more stable carbon transiently preserved from decomposition. The role of the stable pool of soil organic matter on Zn biogeochemical cycling remains poorly understood. The pool of stable carbon is controlled by combination with mineral constituents or is material that is intrinsically resistant to decomposition. The Zn stable isotopes are fractionated by interactions between Zn and soil mineral and organic constituents. This study reports the Zn isotope composition of five Icelandic soil profiles derived from the same parent basalt and characterized by contrasting degrees of weathering and organic matter content (δ66Zn = + 0.10 ± 0.05 to + 0.35 ± 0.02‰), the distribution of reactive mineral constituents available to form associations with soil organic matter, and the amount of stable organic carbon. Throughout these soils, the δ66Zn isotope variations are little influenced by mineral constituents, but rather by soil organic matter content. These data suggest that a combination of organic matter accumulation and Zn loss by leaching is required to explain the observed decrease in Zn concentration in soils and lighter soil δ66Zn with increasing organic carbon content. These results suggest that the presence of stable organic carbon in soils provides a pool of light Zn, attributed to the Zn isotope signature of organic matter partially preserved from decomposition. Crucially, this stable organic carbon pool may also contribute to the formation of the light Zn isotope sink reported in organic-rich marine sediments, a key output required to explain the oceanic mass balance of Zn isotopes.

Ferromanganese (Fe-Mn) deposits constitute a ubiquitous mineral type in oceanic settings, with metal (Cu, Ni, Zn, Co, Pt) and rare earth element (REE) enrichments of potential economic interest. Routine analysis of trace elements by ICP-MS has advanced our understanding of the impact of hydrogenetic, diagenetic and hydrothermal processes on the mobility and interaction of high field strength elements (HFSE: Zr and Ti) and REE and yttrium (REY) with Fe-Mn oxyhydroxides. Recent discoveries in the French exclusive economic zone (EEZ) of Wallis and Futuna (southwest Pacific Ocean) have brought new insight into the formation of low temperature (LT) hydrothermal Mn deposits and lead us to reconsider the classification and discrimination diagrams for Fe-Mn deposits and ore-forming processes. Using a suite of LT hydrothermal Fe-Mn crusts from Wallis and Futuna, we investigate how contrasting genetic processes influence the distribution of metals (Mn, Fe, Cu, Ni, and Co), HFSE and REY in hydrogenetic, diagenetic, hydrothermal and mixed-type deposits from different environments in the global ocean. The interaction of the different metal oxide-forming processes indicates that: (i) enrichment of Co, HFSE and REY is favored by hydrogenetic precipitation, (ii) diagenetic processes produce higher Mn, Cu, and Ni concentrations with oxic remobilization in the sedimentary column, while suboxic conditions promote greater Mn and Fe remobilization that competes with the incorporation of Cu and Ni ions in nodules. HFSE and REY derived from seawater are usually low in diagenetic precipitates, which discriminate between hydrogenetic and diagenetic inputs within nodules, (iii) hydrothermal Fe-Mn deposits show strong depletion in HFSE and REY due to rapid formation and high contents of either Fe or Mn oxides. We present a new discrimination scheme for the genetic types of Fe-Mn deposits using a 10 ∗ (Cu + Ni + Co) − 100 ∗ (Zr + Y + Ce) − (Fe + Mn) / 4 ternary diagram. The use of HFSE and REY in the classification allows for a more robust discrimination of: (i) each ore-forming process with well-delimited fields, without overlap of metal-rich hydrothermal samples and hydrogenetic samples, (ii) oxic and suboxic diagenesis within nodules, (iii) trends between hydrogenetic and diagenetic end-members forming a continuum, and (iv) mixed genetic types such as the presence of hydrothermal particles within hydrogenetic crust layers. Alternatives are also explored to adapt our discriminative diagram to elements measurable by on-board instruments to aid in exploration at sea.

Verticillium wilt, due to the soilborne fungus Verticillium dahliae , is a persistent disease affecting flax culture in Upper Normandy. This pathology has increased since the last decade, leading to yield losses for flax producers. In part due to the long survival of V. dahliae in soil and the difficulty of early diagnosis in affected plant, Verticillium flax wilt management remains problematic in the absence of efficient phytosanitary treatment. Pathogen avoidance and the reduction of soil inoculum through adapted cultural practices are the best alternatives to fight against Verticillium wilt. Therefore, the objective was here to optimize and validate a rapid and specific real-time PCR assay targeting the ribosomal DNA Internal Transcribed Spacers (ITS) to measure V. dahliae density in soil. This method was then used to assess and compare the pathogen density in fields from four diverse management systems: conventional, integrated with or without tillage, and organic. First, the real-time PCR assay provided sensitive and reliable quantification of V. dahliae in a range of artificially inoculated soils with known inoculum density. Then, this method was successfully applied in crop fields. Measured V. dahliae densities presented an intra-parcel heterogeneity, emphasizing the importance of an adapted sampling strategy to assess pathogen load in crop field. Furthermore, these densities appeared to be impacted by agricultural practices, particularly tillage. The influence of the previous crop on pathogen load had also to be considered with attention to manage efficiently this disease through crop rotation. Such knowledge of pathogen density in soils could provide critical information for stakeholders to identify infested fields and predict disease development. Molecular approach should be considered as a useful tool for Verticillium wilt management in flax culture.

Soft wheat grains were subjected to oxidation by ozone treatment. A Box Benhken design with three variables (humidification rate, ozone inlet concentration and reaction time) was used for the experiment. Two wheat cultivars differing on their technological properties were used. The products were characterized by determining rheological, thermal and other physicochemical properties such as RVA (Rapid Visco Analyzer), DSC (Differential Scanning Calorimetry), molecular weight distribution and amylopectin branched chain length distribution. Contrary to previous works, results clearly show no significant effect of ozone treatment on wheat starch in our experimental conditions (i.e. starch extracted from ozonated whole wheat grain) whatever the cultivar studied. Only slight increases of carboxyl groups have been noticed with increasing ozonation. Modifications observed on rheological properties in flour samples (i.e. alveographic and RVA measurements) in previous works (Goze et al., 2015) could mainly be explained by the oxidation of others molecules such as proteins and non-starch polysaccharides.

International audience; To assess the influence of the composition of dissolved organic matter (DOM) on metal speciation, two models have been used: Model VI and NICA-Donnan. The speciation of Cu, Ni, Pb and Zn in the soil solution of 36 samples characterized by alkaline pH and different contamination levels has been determined. Four assumptions about DOM composition have been tested: (i) 100% of humic substances (HS) are fulvic acids (FA), (ii) 100% are humic acids (HA), (iii) 35% are HA and 65% FA and (iv) 84% are HA and 16% FA. The results obtained with the two distinct models are of the same order of magnitude; however, few differences have been highlighted regarding the description of the non-specific interactions, the Zn–FA interactions and the lowest free ion concentrations. The main result of this study is that the free ion concentrations calculated with the two models may differ by one order of magnitude depending on whether HA and/or FA are used to represent DOM. This work demonstrates the impact of the assumptions made about the DOM nature for metal speciation modelling.

Several 60L dry batch anaerobic digestion (AD) reactors were implemented with or without liquid reserve on cattle manure. The immersed part modulation of cattle manure increased the methane flow of about 13%. The quantitative real time PCR and the optimized DNA extraction were implemented and validated to characterize and quantify the methanogen dynamic in dry batch AD process. Final quantities of methanogens converged toward the same level in several inocula at the end of AD. Methanogen dynamic was shown by dominance of Methanosarcinaceae for acetotrophic methanogens and Methanobacteriales for the hydrogenotrophic methanogens. Overall, methanogens populations were stabilized in liquid phase, except Methanosaetaceae. Solid phase was colonized by Methanomicrobiales and Methanosarcinaceae populations giving a support to biofilm development. The methane increase could be explained by a raise of Methanosarcinaceae population in presence of a total contact between solid and liquid phases. Methanosarcinaceae was a bio-indicator of the methane production.

Arable crops are typically grown in annual rotations. Diverse rotations can support ecosystem services, provide economic resilience and support adaptation to climate change. Our aim was to assess farmers' attitudes to planning and diversifying crop rotations, focusing on their responses in the face of contrasting climate viewpoints. We interviewed 75 farmers from four regions along a latitudinal gradient from the south of the UK to the south of France. We used a semi-structured questionnaire with face-to-face interviews and asked farmers to respond to two narrative viewpoints of climate change impacts: one viewpoint focused on opportunities, the other on constraints. We found in all four regions that farmers' use rotations, and the crops within rotations, to achieve their main objectives of financial stability and improved soil health. Most farmers (79-100% depending on region) said they had experienced climate change, and many (54-83%) had already implemented changes in their farming practices. We did not find a difference in these results based on latitude. However, farmers' self-reported outlook was mostly optimistic in southern UK and become progressively more pessimistic further south. Overall, most farmers predicted that they would diversify and lengthen rotations in response to climate change. However, when presented with a viewpoint of climate change impacts focusing on opportunities, more farmers were likely to diversify and lengthen, and fewer were likely to shorten rotations, compared to a viewpoint presenting constraints from these impacts. Crucially, here we show that the presentation of climate change affects the ways in which farmers predict how they will respond to climate change. Diversified rotations would align with multiple other economic and environmental benefits. Therefore, it is essential to consider the way in which climate change impacts are communicated, and the effect on farmers' behavior, when designing measures to support environmentally-sustainable adaptation to climate change.

Digital Soil Mapping (DSM) is increasingly needed to improve existing soil information and derive soil property maps at the suitable spatial resolution for sustainable soil landscape management. However, predicting several soil properties while preserving specific pedological process is a great challenge, particularly when only coarse soil information is available over large areas. Spatial disaggregation seems to be an effective technique to extract pedological information by downscaling the original information to produce soil maps at finer resolutions. In a previous study, legacy soil maps of Brittany (France) were disaggregated at a 50 m spatial resolution using the DSMART (Disaggregation and Harmonization of Soil Map Units Through Resampled Classification Trees) algorithm and pedological knowledge. The present study had two main objectives: (i) assess the preservation of the relationships between soil properties when soil properties are estimated at standard depths by applying the equal-area spline method on soil data at pedon scale, and (ii) combine disaggregated soil maps and spline-function results to estimate spatial patterns of nine soil properties for six regular soil-depth intervals down to 200 cm across Brittany, an area of 27,040 km2. To this end, soil properties were first generated for standard soil-depth intervals using spline functions. Then, for mapping soil properties at the six standard depths, weighted mean of each soil attribute was calculated for each grid cell from reference soil-property values of the three most probable predicted soil types. Their associated probabilities of occurrence were used as weights. To assess the ability of spline functions to preserve soil-property relationships, multiple statistical analyses were performed using original and splined soil datasets. Bivariate and multivariate analysis highlighted that spline functions preserved soil-property relationships. Derived digital soil maps showed strong spatial patterns: SOC and silt contents generally decreased with depth, while sand content and coarse fragment percentage consistently increased with depth. In addition, experimental semivariogram analysis of SOC content showed high spatial variability over short distances for all soil-depth intervals except the deepest (100–200 cm), while silt content showed high semivariance for the deepest soil layers. This study can be considered an example of harmonization to common output specifications, which generates a geo-database of quantitative soil properties that describe lateral and vertical soil variation for regular depth intervals. These predictions can be incorporated into environmental models to help decision makers manage landscapes.

This experimental study provides complete datasets of hygrothermal properties of numerous hemp-clay with density ranging from 200 to 350 kg m-3 for building thermal insulation. In addition, attention is also paid on protocols and methods, on the measurements repeatability and on the influence of conditioning temperature and relative humidity: mean uncertainties do not exceed 10% for all measurements, while initial conditioning influences at most the results, particularly for the sorption isotherm. Heat and moisture storage properties depend obviously of the constituent (hemp or clay). Furthermore, they can be estimated with a good accuracy with a mixing law. Thermal conductivity of the composites ranges between 0.06 and 0.12 W m-1 K-1 and clearly depends on the density. Water vapor diffusion resistance factor ranges between 2.24 and 4.14, while capillary absorption coefficient ranges between 0.027 and 0.135 kg m-2 s-0.5.

International audience; Metal and metalloid (As, Cd, Co, Cu, Pb and Zn) distribution in soils from the Katanga Copperbelt (Democratic Republic of Congo) is investigated in order to characterize the environmental impacts of mining and smelting activities in that area. The concentrations of Cu, Co, As, Zn, Pb and Cd in soils from mining sites are higher than in non-metalliferous sites and above permissible metal and metalloid concentrations in soils. Moreover, the fractionation and mobility of Co, and Cu in such environment is assessed using the application of both ammonium acetate-EDTA extraction and speciation modeling (WHAM 6). The resulting data set covers wide range of environmental conditions (pH, trace metals concentration, natural soils and soils affected by mining and ore processing). These extractions show that only a small fraction of Cu and Co is mobile, with variation depending on sites: mobility is higher in soils affected by mining and ore processing. The strong affinity of Mn-oxides for Co may explain lower Co mobility in Mn-rich soils. The high Mn and Fe contents of Cu–Co soils from Katanga may actually exert a protective effect against the toxic effects of Co. Finally, Cu–Co speciation modeling of contaminated sites emphasizes that organic matter strongly sorb Cu whereas Co speciation is mostly by Mn content. This type of study leads to a better understanding of metal fractionation and can guide to define different practices of phytoremediation.

International audience; Ecological niche modelling helps us to understand the spatial assembly of species in heterogeneous environments. Three patterns have been widely reported in the research literature regarding the relationship between realised niches and macronutrient concentration gradients: (1) species' optima are unevenly distributed, with a higher frequency in mesic conditions; (2) species' response curves are narrower when optima density is higher; and (3) species with optima at the extremes of the gradients have skewed response curves with a longer tail toward mesic conditions. This study aims to test the existence of these patterns on a vegetation model occurring in metalliferous soils comprising copper and cobalt along a toxicity gradient in southeastern D.R. Congo. Realised niches of 80 taxa were modelled using generalised additive models. The niche optima and the niche widths were determined for each taxon. Results highlighted three groups which differ according to the niche optima location along the soil metal concentration gradients. The patterns found along macronutrient concentration gradients were, to some extent, transposable along micronutrient concentration gradients. Our findings on the diversity and assembly of realised niches has consequences for plant conservation strategies.

International audience; Spatial disaggregation of soil map units involves downscaling existing information to produce new information at a finer scale than that of the original source. Currently, it is becoming a powerful tool to address the spatial distribution of soil information over large areas, where legacy soil polygon maps are the only source of soil information. Because of the high expense of additional resampling, few studies have sought to validate disaggregated soil maps using independent sampling. This study implemented spatial disaggregation approach to measure the quality of soil property predictions derived from disaggregated soil maps, using stratified simple random sampling of a study area of 6848 km2 (11 strata and 135 soil profiles). In a previous study, the existing legacy soil polygon map of Brittany (France) at 1:250,000 scale was spatially disaggregated at 50 m resolution using an algorithm called Disaggregation and Harmonisation of Soil Map Units Through Resampled Classification Trees (DSMART), which uses soil-landscape expert rules of soil distribution in space. By fitting equal-area spline functions, soil properties were then estimated at six depth intervals according to GlobalSoilMap specifications. To validate disaggregated soil maps, two approaches were developed according to the soil attribute nature (continuous or categorical). For categorical soil properties (soil parent material, soil drainage class, soil type and soil depth class), the overall strict purity (the degree to which all classification criterion are respected) by the most probable STU (Soil Typological Unit) map was estimated at 34%, while the overall average purity reached 70%. The overall partial soil-type purity reached 60%, the overall partial parent material purity reached 78% and the overall partial soil drainage class as well as soil depth class purities reached 65% and 78%, respectively. Continuous soil properties (clay content, fine silt content, coarse silt content, total silt content, fine sand content, coarse sand content, coarse fragments, Cation Exchange Capacity (CEC) and pH) were validated at two soil depth intervals (5–15 and 30–60 cm) using 260 soil samples. In general, soil property predictions were unbiased except for coarse fragments and CEC in the 5–15 cm layer. Validation statistics (R2, RMSE, RRMSE and ME) were better for the 30–60 cm layer except for soil particle-size distribution. Thus, differences in prediction accuracies among strata (the validation support) denote areas where more soil data or better soil prediction models are needed to improve the disaggregation process.

The microwave heating of wheat kernels, flour, and gluten, has attracted attention lately because it has been claimed to abolish gluten toxicity for celiac patients. Nevertheless, contradictory results have been reported regarding the effect on gluten celiac-immunotoxicity. In order to better understand the effect of the microwave treatment on gluten structure, conformation, functionality and celiac-immunotoxicity, a central composite design with two factors, power level, and treatment time, was used to investigate a possible quadratic and interaction effects between both factors. Extractable gliadins content was affected by the power and time in a linear and quadratic fashion; extractable glutenins were not affected. Gluten secondary structure was affected by the microwave treatment and related to the polymer's disaggregation phenomenon observed. In fact, the microwave treatment increased the amount of potentially toxic epitopes released after peptic and tryptic digestion, showing inefficiency as a treatment to detoxify the gluten for celiac disease patients.

International audience; Within the recent years, researches dealing with the applications of intelligent and active packaging for food applications have taken a great importance. Intelligent packaging-systems are used to inform and advertise the consumers by giving information on the food quality during transport and storage. Active packaging-systems have also acquired new functions as antimicrobials and/or oxygen or water scavenging activities by incorporating active molecules. The aim of these packaging is to maintain or extend the quality and shelf-life of the food element. The application of this strategy, concerning bio-sourced packaging, is recent. In this work, polycaprolactones were blended in a starch based matrix to improve the suitability for contact with food of the packaging and to obtain a modulated water-scavenger effect. The migration of PCL in the pseudo-multilayered and multilayered films was investigated by FT-IR. Moreover, chitosan was included in the formulation to reduce the bacterial adhesion potential on the packaging.

International audience; One of the most serious environmental issues related to mining industry in Morocco and elsewhere around the world, is the pollution from abandoned mine sites. Mine wastes cause obvious sources of soil contaminations. Climatic effects such as heavy rainfall engender metal dispersion in semi-arid areas, since soils are typically and scarcely vegetated. In this study, extension and magnitude of soil contaminations with toxic elements from abandoned Kettara mine, in Morocco, are assessed using geochemical analysis and geostatistics for mapping. Soils and mine wastes are sampled and analyzed for 41 chemical elements (Mo, Cu, Pb, Zn, Ag, Ni, Co, Mn, Fe, As, U, Au, Th, Sr, Cd, Sb, Bi, V, Ca, P, La, Cr, Mg, Ba, Ti, Al, Na, K, W, Zr, Ce, Sn, Y, Nb, Ta, Be, Sc, Li, S, Rb and Hf). Based on enrichment factor (EF), only five elements of interest (Cu, Pb, Zn, As, and Fe) were selected in this research. Geochemical background is determined with exploratory data analysis and geochemical maps were elaborated using geostatistics in Geographic Information System (GIS) environment.The obtained results show that Kettara soils are contaminated with metals and metalloid that exceed the established geochemical background values (Cu ≈ 43.8 mg/kg, Pb ≈ 21.8 mg/kg, Zn ≈ 102.6 mg/kg, As ≈ 13.9 mg/kg and Fe ≈ 56,978 mg/kg). Geochemical maps show that the deposited mine wastes are responsible for soil contaminations with released metals and metalloid that have been dispersed downstream from the mine waste mainly, through water after rainfall. For sustainable development and environmental planning, the current study is expected to serve as a reference for politicians, managers, and decision makers to assess soil contaminations in abandoned mine sites in Morocco.

Crepidorhopalon perennis is an endemic metallophyte restricted to only one site on Cu-rich soils in Katanga. Crepidorhopalon tenuis has a broader niche, from normal to Cu-rich soils, but has high affinity for cupriferous habitats. Both plants have been considered as Cu-Co accumulators. Cu tolerance and accumulation of C. tenuis were studied in axenic conditions in vitro in four metallicolous populations and one non-metallicolous population whereas for C. perennis only one population was investigated. Results showed a Cu tolerance of both C. tenuis and C. perennis. Variation of tolerance among metallicolous and non-metallicolous populations was also observed. The addition of Cu enhanced the growth of some metallicolous populations under sterile conditions, hence confirming the high needs in copper of metallicolous populations. This could represent a cost of tolerance which would explain the high affinity of species for cupriferous habitats. On the other hand, Crepidorhopalon perennis did not show the same features. Its restricted distribution may be explained by a cost of Cu tolerance. Crepidorhopalon perennis and C. tenuis are not Cu hyperaccumulators and seem to behave rather like excluder species., SCOPUS: ar.j, info:eu-repo/semantics/published

International audience; Hyaluronidase (HAase) plays an important role in the control of the size and concentration of hyaluronan (HA) chains, whose biological properties strongly depend on their length. Our previous studies of HA hydrolysis catalyzed by testicular HAase demonstrated that, whilst the substrate-dependence curve has a Michaelis-Menten shape with a 0.15 mol L − 1 ionic strength, at low ionic strength (5 mmol L − 1), a strong decrease in the initial hydrolysis rate is observed at high substrate concentrations; the HA concentration for which the initial rate is maximum increases when the HAase concentration is increased. After examination of various hypotheses, we suggested that this could be explained by the ability of HA to form non-specific complexes with HAase, which thus becomes unable to catalyze HA hydrolysis. In order to verify this hypothesis, we first showed from turbidimetric measurements that HAase, like albumin, is able to form electrostatic complexes with HA. Albumin then was used as a non-catalytic protein able to compete with HAase for the formation of non-specific complexes with HA, allowing HAase to be free and catalytically active. The kinetic results showed that the HA-HAase non-specific complex inhibits HAase catalytic activity towards HA. Depending on the albumin concentration with respect to the HAase and HA concentrations, albumin can either remove this inhibition or induce another type of inhibition. Finally, the extent of such non-specific interactions between polyelectrolytes and proteins in HAase inhibition or activation, in particular under in vivo conditions, is discussed.