Search results for "LER"
showing 10 items of 14795 documents
Retrospective environmental biomonitoring – Mussel Watch expanded
2016
Abstract Monitoring bioavailable contaminants and determining baseline conditions in aquatic environments has become an important aspect of ecology and ecotoxicology. Since the mid-1970s and the initiation of the Mussel Watch program, this has been successfully accomplished with bivalve mollusks. These (mostly) sessile organisms reliably and proportionately record changes of a range of organic and inorganic pollutants occurring in the water, food or sediment. The great majority of studies have measured the concentration of pollutants in soft tissues and, to a much lesser extent, in whole shells or fractions thereof. Both approaches come with several drawbacks. Neither soft tissues nor whole…
Triterpene glycosides from Blighia welwitschii and evaluation of their antibody recognition capacity in multiple sclerosis
2020
Multiple sclerosis (MS) in a multifactorial autoimmune disease in which reliable biomarkers are needed for therapeutic monitoring and diagnosis. Autoantibodies (autoAbs) are known biomarker candidates although their detection in biological fluids requires a thorough characterization of their associated antigens. Over the past twenty years, a reverse chemical-based approach aiming to screen putative autoantigens has underlined the role of glycans, in particular glucose, in MS. Despite the progress achieved, a lack of consensus regarding the nature of innate antigens as well as difficulties proposing new synthetic glucose-based structures have proved to be obstacles. Here is proposed a strate…
Morphological variations of crossed-lamellar ultrastructures of Glycymeris bimaculata (Bivalvia) serve as a marine temperature proxy
2020
Abstract Bivalve shells are among the most promising archives for high-resolution seawater temperature reconstructions. However, despite major research advances in bivalve sclerochronology over the past decades, estimating water temperature from shells remains a challenging task. This is largely because the most frequently used and widely accepted temperature proxy in bivalves, i.e., the shell oxygen isotope (δ18Oshell) value, also requires knowledge of changes in δ18O of the water (δ18Owater) in which the bivalve lived, which is rarely available for ancient environments. According to a few recent studies, the size and shape of individual biomineral units (BMUs) of the shell ultrastructure …
Antibiotics accelerate growth at the expense of immunity
2021
Antibiotics have long been used in the raising of animals for agricultural, industrial or laboratory use. The use of subtherapeutic doses in diets of terrestrial and aquatic animals to promote growth is common and highly debated. Despite their vast application in animal husbandry, knowledge about the mechanisms behind growth promotion is minimal, particularly at the molecular level. Evidence from evolutionary research shows that immunocompetence is resource-limited, and hence expected to trade off with other resource-demanding processes, such as growth. Here, we ask if accelerated growth caused by antibiotics can be explained by genome-wide trade-offs between growth and costly immunocompete…
A mycorrhiza helper bacterium enhances ectomycorrhizal and endomycorrhizal symbiosis of Australian Acacia species.
2003
The aims of this study were to test the effects of a mycorrhiza helper bacterium (MHB), Pseudomonas monteilii strain HR13 on the mycorrhization of (1) an Australian Acacia, A. holosericea, by several ectomycorrhizal fungi or one endomycorrhizal fungus Glomus intraradices, and (2) several Australian Acacia species by Pisolithus alba strain IR100 under glasshouse conditions. Bacterial inoculant HR13 significantly promoted ectomycorrhizal colonization for all the Acacia species, from 45.8% ( A. mangium) to 70.3% ( A. auriculiformis). A stimulating effect of HR13 on the ectomycorrhizal establishment was recorded with all the fungal isolates (strains of Pisolithus and Scleroderma). The same effe…
Stress for invasion success? Temperature stress of preceding generations modifies the response to insecticide stress in an invasive pest insect
2012
Adaptation to stressful environments is one important factor influencing species invasion success. Tolerance to one stress may be complicated by exposure to other stressors experienced by the preceding generations. We studied whether parental temperature stress affects tolerance to insecticide in the invasive Colorado potato beetle Leptinotarsa decemlineata. Field-collected pyrethroid-resistant beetles were reared under either stressful (17°C) or favourable (23°C) insecticide-free environments for three generations. Then, larvae were exposed to pyrethroid insecticides in common garden conditions (23°C). Beetles were in general tolerant to stress. The parental temperature stress alone affect…
Energetic reserves, leptin and testosterone: a refinement of the immunocompetence handicap hypothesis.
2007
Electronic supplementary material is available at http://dx.doi.org/10.1098/rsbl.2007.0020 or via http://www.journals.royalsoc.ac.uk.
Effectifs et recrutement du clergé séculier français à la fin du Moyen Age
1993
Il n'existe dans aucun diocèse français d'état descriptif du clergé, de matricule qui aurait permis aux évêques ou à leurs officiers de prendre une vue globale des effectifs de clercs placés sous leur juridiction. La question ne les préoccupait sans doute guère, puisque les registres de visites pastorales, s'ils comptent les livres liturgiques et observent les tuiles des toitures, ne dénombrent pas systématiquement les prêtres et les clercs de chaque paroisse. Un document de ce type n'apparai...
Synergistic reduction of a native key herbivore performance by two non-indigenous invasive algae
2019
Abstract Native generalist grazers can control the populations of non-indigenous invasive algae (NIIA). Here, it was found that the simultaneous consumption of two co-occurring NIIA, Caulerpa cylindracea and C. taxifolia var. distichophylla, hinders the grazing ability of the main Mediterranean herbivorous, the native sea urchin Paracentrotus lividus. The ingestion of any of the two NIIA alone did not produce any difference in sea urchin righting time with respect to usual algal diet. In contrast, the simultaneous consumption of both NIIA, which grow intermingled in nature and are consumed by P. lividus, retarded its righting behavior. Such result reveals substantial physiological stress in…
Classification of European and Mediterranean coastal dune vegetation
2018
Aims: Although many phytosociological studies have provided detailed local and regional descriptions of coastal dune vegetation, a unified classification of this vegetation in Europe and the Mediterranean Basin has been missing. Our aim is to produce a formalized classification of this vegetation and to identify the main factors driving its plant species composition at a continental scale. LocationAtlantic and Baltic coasts of Europe, Mediterranean Basin and the Black Sea region. - Methods: We compiled a database of 30,759 plots of coastal vegetation, which were resampled to reduce unbalanced sampling effort, obtaining a data set of 11,769 plots. We classified these plots with TWINSPAN, int…