Characterization of suspended particulate matter in the Moselle River (Lorraine,France): evolution along the course of the river and in different hydrologic regimes

Purpose

Suspended particulate matter (SPM) plays an important role in the transport and fate of contaminants in the environment. To better understand the relationships between contaminants and SPM, SPM properties, and their variations with flow regime, river size, land use, and season should be considered.

Materials and methods

The grain size distribution, elemental composition, and mineralogy of SPM from different stations along the Moselle River (Lorraine, France) were investigated at the particle scale during different flow regimes. The resulting data were compared with the elemental composition of the dissolved compartment to understand the role of particles in element transport.

Results and discussion

The grain size distribution, elemental composition, and mineralogy of SPM along the Moselle River and during different flow regimes showed only slight variations, except for the Fensch and Orne tributaries, two rivers that were impacted by inherited steel-making industrialization and different land use. In the Moselle River, SPM mainly consisted of clay minerals, while in Fensch and Orne Rivers, SPM mainly consisted of multiple types of anthropogenic particles. The diffuse urbanization gradient was hardly recognized based on the Trace Metal Element (TMEs) content in the river SPM, while the rivers impacted by the steel industries had greater TME contents. Finally, the TME content in the Moselle SPM was more strongly influenced by water flow than by the position of sampling on the linear reach of the Moselle River. The partitioning of TMEs in the particles and water at the main Moselle station (Frouard) revealed that SPM predominantly contributed to TMEs transport.

Conclusions

This study confirmed that catchment geology greatly contributed to the SPM composition in the mean-sized rivers. In addition, the high anthropogenic pressure could be deciphered for small tributaries. Furthermore, this study allowed us to observe the high contribution of particles to TMEs and Rare Earth Element (REEs) transportation.

     

Assessing success in gene transfer betweenLolium multiflorum andFestuca arundinacea

Summary AFestuca arundinacea (2n=6x-42) plant with three PGI/2 homoeoalleles marking three homoeologous chromosomes was crossed with aLolium multiflorum plant (2n=4x=28) with a different PGI/2 phenotype to give a pentaploid hybrid (2n=5x=35) with five chromosomes each marked by a different PGI/2 allele. This hybrid plant was backcrossed twice with diploidL. multiflorum (2n=2x=14) with a different PGI/2 phenotype. Numbers of interspecific recombinants involving chromosomes marked by PGI/2 were then determined in both backcross generations. In the BC1, recombinants involving only one PGI/2 allele were found but in the BC2, all three homoeologousF. arundinacea chromosomes carrying the PGI/2 locus recombined withLolium with one in greater frequency and the others in equal but lower frequency. The evidence supports claims made forF pratensis (2n=2x=14) andF. arundinacea var.glaucescens (2n=4x=28) being progenitors forF. arundinacea.     

Transverse shrinkage in G-fibers as a function of cell wall layering and growth strain

Transverse drying shrinkage was measured at microscopic and mesoscopic levels in poplar wood characterised by an increasing growth strain (GS), from normal to tension wood. Results show that: (a) the drying shrinkage, measured as a relative thickness decrease, was significantly higher for G-layer (GL) than for the other layers (OL), GL shrinkage was not significantly correlated with GS, and OL shrinkage was negatively correlated with GS. (b) In gelatinous fibre (G-fibre), lumen size increased during drying and this increase was positively related with GS, but in normal wood fibre, lumen size decreased during drying. These findings suggest that GL shrank outwards (i.e., its internal perimeter increases), so that its shrinkage weakly affected the total cell shrinkage and the mesoscopic shrinkage was controlled by the OL shrinkage which shrank inwards (i.e., its external perimeter decreases). (c) Measurements done on 7 × 7 mm2 thin sections evidenced a negative correlation between transverse shrinkage and GS, significant in T direction but weak in R direction. These observations at both levels allow to discuss the contribution of GL to the mesoscopic shrinkage of tension wood.     

Soil carbon dioxide efflux in pure and mixed stands of oak and beech

Total Soil Respiration (TSR) was measured in pure and mixed stands of oak and beech and was partitioned into two contributions using the forest floor removal technique: Mineral Soil Respiration (MSR) and Forest Floor Respiration (FFR). In addition, laboratory incubations of the forest floor and the Ah horizon were performed to evaluate the heterotrophic respiration and the DOC production of these horizons. The relationships between soil temperature and the various soil respiration contributions in the three stands were compared using Q ₁₀ functions. In situ, significant differences (α = 0,05) between stands were observed for the R ₁₀ parameter (respiration rate at 10 °C) of the TSR, MSR and FFR contributions, while only the temperature sensitivity (Q ₁₀) of TSR was significantly affected by stand composition. The effect of soil water content was only significant on MSR and followed different patterns according to stand composition. Under controlled conditions, the R ₁₀ of the forest floor and of the Ah horizon varied with stand composition and the Q ₁₀ of the forest floor decreased in the order: oak (2.27) > mixture (2.01) > beech (1.71).     

Chemical composition and pharmacological activity of essential oil of Canarium schweinfurthii

The essential oil obtained by hydrodistillation of the resin of Canarium schweinfurthii growing in Central African Republic, was analysed by GC and GC/MS and its analgesic and antiinflammatory effects were studied. The major constituents of the essential oil were octylacetate (60%) and nerolidol (14%). At the doses of 1, 2 and 3 ml/kg i.p. essential oil shows a significant analgesic effect using acetic acid-induced writhing and hot plate methods. However, its was unable to reduce inflammatory process in cotton pellet induced granuloma method.     

A new acylated quercetin glycoside from Ranunculus lanuginosus

A new acylated quercetin glycoside, quercetin 3-O-(2-t-p-coumaroyl)-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside-7-O-beta-D-glucopyranoside (1), together with the known 3-(3,4-dihydroxyphenyl)lactic acid (2) were isolated from Ranunculus lanuginosus leaves and identified on the basis of detailed spectral analysis, including 2D-NMR spectrometry and ESI-MS.     

Antibacterial and antioxidant activities of Artemisia annua essential oil

The essential oil of Artemisia annua aerial parts, consisting of camphor (44%), germacrene D (16%), trans-pinocarveol (11%), beta-selinene (9%), beta-caryophyllene (9%) and artemisia ketone (3%), was screened for its antimicrobial activity. The essential oil remarkably inhibited the growth of tested Gram-positive bacteria Enterococcus hirae and both tested fungi. This oil has shown an antioxidant activity equivalent to 18% of the reference compound (alpha-tocopherol).