Polybrominated Diphenyl Ether Dynamics in Ambient Air and Atmospheric Bulk/Wet Deposition in Downtown Paris (France)     

Khawla Tlili  Pierre Labadie  Fabrice Alliot  Catherine Bourges  Annie Desportes  Marc Chevreuil 《Water, air, and soil pollution》2012,223(4):1543-1553

This study reports on the polybrominated diphenyl ether (PBDE) atmospheric dynamics in the dense urban environment of downtown Paris (France). Eight PBDE congeners (BDE-28, BDE-47, BDE-100, BDE-99, BDE-154, BDE-153, BDE-183 and BDE-209) were simultaneously analysed in bulk and wet atmospheric deposition, as well as in ambient air (gaseous/particulate phases), twice a month over a 12-month period (May 2008–May 2009). The total air concentration of Σ 8PBDEs ranged between 12 and 185 pg m⁻³, and the seasonal variations of PBDE levels were controlled by air temperature (except for BDE-209). Regarding bulk deposition, Σ 8PBDE flux was in the range 5–94 ng m⁻² day⁻¹, and it was positively correlated with atmospheric particulate phase PBDE concentrations. Meanwhile, the measured wet deposition flux of Σ 8PBDE ranged between 2 and 24 ng m⁻² day⁻¹, and its median contribution to bulk deposition was 39% only, which highlights the importance of dry deposition.  相似文献   

Assessment of the resilience and resistance of remediated soils using denitrification as model process     

Farhan Hafeez  Laurent Philippot  Aymé Spor  Fabrice Martin-Laurent 《Journal of Soils and Sediments》2014,14(1):178-182

Purpose

Soil contamination by pollutants is increasing, urging for remediation strategies but little is known about the functional sustainability of these strategies.

Materials and methods

We assessed the resistance and resistance of a microbial respiratory process, denitrification, to two different levels of heat-drought disturbances among (1) thermally treated industrial soil, (2) constructed Technosol made of thermally treated soil, compost, and paper by products, and (3) an arable soil.

Results and discussion

We showed that thermal remediation lead to low resistance and resilience after disturbances. However, addition of compost and paper mill sludge improved the stability.

Conclusions

This work underlines the relevance of resistance and resilience ecological concepts for assessing remediation strategies.  相似文献   

Two‐Step Surgery Combining Standing Laparoscopy With Recumbent Ventral Median Celiotomy for Removal of Enlarged Pathologic Ovaries in 20 Mares     

Amélie Vitte DVM  Fabrice Rossignol DVM  Diplomate ECVS  Céline Mespoulhes‐Rivière DVM  Diplomate ECVS  Antoine Lechartier DVM  Michael Röecken DVM 《Veterinary surgery : VS》2014,43(6):663-667

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In vitro comparison of two techniques for suture prosthesis placement in the muscular process of the equine arytenoid cartilage     

Rossignol F  Perrin R  Desbrosse F  Elie C 《Veterinary surgery : VS》2006,35(1):49-54

OBJECTIVE: To compare in vitro the load necessary for a partial and complete rupture of the muscular process arytenoid cartilage when a suture prosthesis is positioned by a bone trocar versus a trocar point needle and to compare failure mode. STUDY DESIGN: Experimental using cadaver specimens. SAMPLE POPULATION: Larynges from 18 Thoroughbred race horses, aged 2-20 years. METHODS: Arytenoid cartilages were separated randomly into 2 groups: group 1-suture prosthesis inserted directly through the muscular process using a curved trocar point needle and group 2-suture passed through a hole predrilled with a 3 mm bone trocar. Distracting force (constant rate, 1 mm/s) was applied to the suture until failure of the muscular process. Partial failure load, maximum load at complete failure, and force-time curve were recorded. Each arytenoid cartilage was examined, radiographed, and classified as having a linear or curved failure plane. RESULTS: No significant differences in mechanical test variables were detected. Failure mode followed the fissures occurring at the beginning of failure and then followed the tension axis. Significantly more linear failures occurred in group 2 (trocar) and more curved failures occurred in group 1 (needle). CONCLUSION: Use of a bone trocar for tunneling through the muscular process may reduce fissure formation. CLINICAL RELEVANCE: Use of bone trocar to create a hole in the muscular process of the arytenoid cartilage for suture passage in laryngoplasty may reduce fissure formation and decrease the risk of cartilage failure from suture pullout.  相似文献   

pcaH, a molecular marker for estimating the diversity of the protocatechuate-degrading bacterial community in the soil environment     

El Azhari N  Chabaud S  Percept A  Bru D  Martin-Laurent F 《Pest management science》2007,63(5):459-467

Microorganisms degrading phenolic compounds play an important role in soil carbon cycling as well as in pesticide degradation. The pcaH gene encoding a key ring-cleaving enzyme of the beta-ketoadipate pathway was selected as a functional marker. Using a degenerate primer pair, pcaH fragments were cloned from two agricultural soils. Restriction fragment length polymorphism (RFLP) screening of 150 pcaH clones yielded 68 RFLP families. Comparison of 86 deduced amino acid sequences displayed 70% identity to known PcaH sequences. Phylogenetic analysis results in two major groups mainly related to PcaH sequences from Actinobacteria and Proteobacteria phyla. This confirms that the developed primer pair targets a wide diversity of pcaH sequences, thereby constituting a suitable molecular marker to estimate the response of the pca community to agricultural practices.  相似文献   

Sources of spatial and temporal variability of inorganic nitrogen in pure and mixed deciduous temperate forests     

Michaël Aubert  Fabrice Bureau  Marthe Vinceslas-Akpa 《Soil biology & biochemistry》2005,37(1):67-79

We investigated the influence of tree canopy composition and structure on the spatial and temporal variability of (i) concentrations of inorganic N (NH₄⁺ and NO₃⁻) and (ii) net N-mineralization and net nitrification, within the temperate forest floor. We compared a pure European beech stand (PS) with a mixed beech-hornbeam one (MS). Three sampling areas were chosen in each stand. Within the PS, the tree locations represented a decreasing gradient of light intensity reaching the forest floor. Within the MS they represented a gradient in the amount of hornbeam leaves present in the litter. In the field NH₄⁺ and NO₃⁻ concentrations were measured in the upper mineral soil (UMS) and the overlying organic layers (OL and OF+OH). Field exposures using buried bags were carried out on UMS over 1 year to measure in situ net N-mineralization and net nitrification. Potential net N-mineralization and net nitrification were investigated in summer with UMS, OL and OF+OH incubated at 28 °C for 28 days in the laboratory. We hypothesize that with the presence of a mull-forming species (hornbeam) within a stand dominated by a moder-forming one (European beech), (i) the spatial and (ii) temporal patterns of soil inorganic N concentrations, net N-mineralization and net nitrification would be different in the two stands. Our main results show that tree species composition has an influence on both spatial and temporal patterns of nitrification. The PS exhibited its highest peaks of UMS NO₃⁻ concentration and net nitrification in spring and early summer while they were highest in the MS in winter. Furthermore, PS exhibited a higher rate of net nitrification than MS. We discuss this unexpected result and suggest that dissolved organic C may be the controlling factor for net nitrification in the MS.  相似文献   

Earthworm communities in a wet agricultural landscape of the Seine Valley (Upper Normandy, France) The 7th international symposium on earthworm ecology · Cardiff · Wales · 2002     

Thibaud Decaë  ns  Fabrice Bureau  Pierre Margerie 《Pedobiologia》2003,47(5-6):479-489

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Grassland-to-crop conversion in agricultural landscapes has lasting impact on the trait diversity of bees     

Le Provost  Gaëtane  Badenhausser  Isabelle  Violle  Cyrille  Requier  Fabrice  D’Ottavio  Marie  Roncoroni  Marilyn  Gross  Louis  Gross  Nicolas 《Landscape Ecology》2021,36(1):281-295

Context

Global pollinator decline has motivated much research to understand the underlying mechanisms. Among the multiple pressures threatening pollinators, habitat loss has been suggested as a key-contributing factor. While habitat destruction is often associated with immediate negative impacts, pollinators can also exhibit delayed responses over time.

Objectives

We used a trait-based approach to investigate how past and current land use at both local and landscape levels impact plant and wild bee communities in grasslands through a functional lens.

Methods

We measured flower and bee morphological traits that mediate plant–bee trophic linkage in 66 grasslands. Using an extensive database of 20 years of land-use records, we tested the legacy effects of the landscape-level conversion of grassland to crop on flower and bee trait diversity.

Results

Land-use history was a strong driver of flower and bee trait diversity in grasslands. Particularly, bee trait diversity was lower in landscapes where much of the land was converted from grassland to crop long ago. Bee trait diversity was also strongly driven by plant trait diversity computed with flower traits. However, this relationship was not observed in landscapes with a long history of grassland-to-crop conversion. The effects of land-use history on bee communities were as strong as those of current land use, such as grassland or mass-flowering crop cover in the landscape.

Conclusions

Habitat loss that occurred long ago in agricultural landscapes alters the relationship between plants and bees over time. The retention of permanent grassland sanctuaries within intensive agricultural landscapes can offset bee decline.

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Magnetic Signature of Industrial Pollution of Stream Sediments and Correlation with Heavy Metals: Case Study from South France     

Desenfant  Fabrice  Petrovský  Eduard  Rochette  Pierre 《Water, air, and soil pollution》2004,152(1-4):297-312

Industrial pollution is one of the most important environmentalthreats, with serious consequences for the future. Thus, its detailed study is of great importance. Apart from expensive andtime-consuming chemical methods, several rapid and cheap proxymethods have been developed recently, one of them being based on rock-magnetic parameters. In the present paper we examine the use of rock-magnetic methods designed to assess the degree of pollution of recent stream sediments taken from the Arc river (Provence, France). The aim was to identify industrially-derived magnetic particles and to link this `magnetic pollution' to concentrations of heavy metals. Geological basements allow the easy determination of magnetic particles of industrial origin. Our results clearly demonstrate that magnetic anomalies, observed in the stream sediments along the river, can be explained by human activities, as they correlate well with concentrations of lead, zinc, iron and chromium.  相似文献   

Spatial distribution of earthworm species assemblages in a chalky slope of the Seine Valley (Normandy, France)     

Pierre Margerie  Thibaud Decaëns  Fabrice Bureau  Didier Alard 《European Journal of Soil Biology》2001,37(4)

The aim of this study was to characterize the spatial distribution of earthworm species assemblages on a chalky slope of the Seine Valley (Upper Normandy, France), with contrasting vegetation cover representing the different stages of a typical post-pastoral secondary succession. Samples were hand sorted in a spatially explicit design consisting of a regular grid. A Principal Component Analysis was performed to identify species associations. Maps of the factorial coordinates of sample points together with geostatistical analysis were used to describe the spatial structure of the assemblages. The first axis of the PCA opposed points with high density to others with low. The resulting spatial structure was significant. The second axis opposed points where species assemblages were dominated either by an endogeic (Allolobophora chlorotica), an anecic (Aporrectodea longa) and an epigeic species (Lumbricus castaneus) to others dominated by two endogeics (Aporrectodea rosea and Octolasium cyaneum). A significant spatial structure was detected, with alternating patches characterised by one species assemblage or the other. The location of these structures did not seem to be clearly associated with a specific vegetation type. These results  revealed a complex determinism of species co-occurrence at small spatial scale.  相似文献