Search results for "accumulation"
showing 10 items of 240 documents
Arbuscular mycorhizal proteomes: what news at the nearby and distant horizon?
2007
International audience; Proteomics has soon emerged as a powerful tool to point out protein modifications in roots interacting with arbuscular mycorrhiza (AM) fungi. Depending on the developmental mycorrhizal stage and on the available amount of mycorrhizal material, untargeted and/or sub-cellular proteomic approaches were applied to reveal and identify proteins whose accumulation was modified during the AM colonisation of Medicago truncatula roots. For the early stage of symbiosis, the protein patterns obtained from noninoculated roots and roots synchronized for appressorium formation in wild-type (Jemalong J5), penetration-defective (TRV25, dmi3) and autoregulation-defective (TR122, sunn)…
The contribution of M. truncatula to the understanding of complex developmental processes in legumes: the case for seed reserve accumulation
2009
National audience
Low human capital accumulation traps among French NEETs: A Multidimensional and Fuzzy approach
2019
International audience; NEETs are generally considered as young people who cannot acquire human capital either through education, training or professional experience. The aim of this communication is to discuss this issue taking in to account the heterogeneity of human capital acquisition among young people. We use a multidimensional and fuzzy approach. The main advantage of this approach is that it makes it possible to construct an indicator that is similar to a membership function by including different deprivation dimensions. The data used come from the French National Survey of Youth Resources conducted by DREES/INSEE (5800 people aged 18 to 24). Our results show a strong heterogeneity …
L’artisan, son comptable et sa retraite. Etude d’un profil d’indépendants établis
2017
International audience; En complément des constats statistiques de la recherche sur l’accumulation patrimoniale chez les indépendants, l’article vise à contribuer à une compréhension des choix faits par les artisans pour préparer leur retraite. Il prend au sérieux la persistance d’une conception professionnelle de la retraite, fondée sur un souci d’autoprotection de ses vieux jours, qui semble expliquer un niveau de détention patrimoniale des ménages indépendants très supérieur à celui des ménages salariés. Étayée par une enquête qualitative, à la fois circonscrite géographiquement et centrée sur un profil d’artisans du bâtiment établis, l’analyse propose de rendre compte de deux mécanismes…
Extrapolation of the Species Accumulation Curve for Incomplete Species Samplings: A New Nonparametric Approach to Estimate the Degree of Sample Compl…
2015
9 pages; International audience; Incomplete species samplings are deemed to remain the common practice in those groups of animals, such as small or micro- invertebrates, with numerous species that often are more or less difficult to detect in the field. Thus, extrapolating the Species Accumulation Curve as far as possible beyond the actual sample size may thus serve as a useful (although imperfect) surrogate to the desired, but practically inaccessible, complete samplings. In this context, several kinds of theoretical or empirical models for the Species Accumulation Curve and also a lot of estimators of the asymptotic limit of the Curve (i.e. total species richness) have been proposed. The …
Influence of light exclusion on anthocyanin composition in "Cabernet Sauvignon"
2011
On the Ability of Perfluorohexane Sulfonate (PFHxS) Bioaccumulation by Two
2019
PFASs (perfluoroalkyl and polyfluoroalkyl substances) are highly fluorinated, aliphatic, synthetic compounds with high thermal and chemical stability as well as unique amphiphilic properties which make them ingredients in a range of industrial processes. PFASs have attracted consideration due to their persistence, toxicity and bioaccumulation tendency in the environment. Recently, attention has begun to be addressed to shorter-chain PFASs, such as perfluorohexane sulfonate [PFHxS], apparently less toxic to and more easily eliminated from lab animals. However, short-chain PFASs represent end-products from the transformation of fluorotelomers whose biotic breakdown reactions have not been ide…
Processing of metals and metalloids by actinobacteria: Cell resistance mechanisms and synthesis of metal(loid)-based nanostructures
2020
Metal(loid)s have a dual biological role as micronutrients and stress agents. A few geochemical and natural processes can cause their release in the environment, although most metal-contaminated sites derive from anthropogenic activities. Actinobacteria include high GC bacteria that inhabit a wide range of terrestrial and aquatic ecological niches, where they play essential roles in recycling or transforming organic and inorganic substances. The metal(loid) tolerance and/or resistance of several members of this phylum rely on mechanisms such as biosorption and extracellular sequestration by siderophores and extracellular polymeric substances (EPS), bioaccumulation, biotransformation, and me…
Biotic methylation of mercury by intestinal and sulfate-reducing bacteria and their potential role in mercury accumulation in the tissue of the soil-…
2014
Abstract Monomethylmercury as one of the most toxic mercury species influences the health and development of higher organisms and tends to accumulate in the tissue of animals and humans. The aim of this study was to explore the mercury methylating capability of (1) intestinal microbiota of the soil-living earthworm Eisenia foetida (E. foetida) and (2) intestinal sulfate reducing-bacteria in pure cultures. After exposing animals to inorganic mercury chloride (4 mg kg−1 Hg2+) in soil and sterile soil for ten days, the amount of methylmercury in tissue was measured. Despite sterilization of soil, the accumulation of the organic mercury species in tissue was 51 ng g−1. To elucidate the potentia…
Bioaccumulation of organochlorine compounds in earthworms
1992
Abstract Bioaccumulation of chlorophenolic wood preservatives 2,3,4,6-tetrachlorophenol (2346-TeCP) and pentachlorophenol (PeCP) and their metabolites in earthworms were studied in the laboratory, and by taking worm samples from the contaminated soil of a sawmill which was abandoned 28 yr ago. In two laboratory experiments 2346-TeCP (containing PeCP as impurity) was added into the soil, and samples were taken at certain intervals both from the soil and the earthworms ( Lumbricus rubellus in experiment 1 and Aporrectodea caliginosa tuberculata in experiment 2). Considerable amounts of chlorophenols were found in field samples. Soil concentrations ranged from 157 to 338 μg 2346-TeCP g −1 dry …