Search results for "Crust"
showing 10 items of 599 documents
BIOCLEANING
2017
Cleaning is one of the first and most important steps in conservative restora- tion intervention, as it removes the unwanted layers of dirt and deposit from the surface of an artefact. It must be done selectively, however, by adapting the cleaning operation to the different zones and removing successive layers of deposit without acting directly on the original materials of the surface. Generally, cleaning protocols are based on chemical or physical procedures with potential negative effects for restorers’ health and/or for the materials constituting the artworks. As an alternative, solvent gels, rigid gels and resin soaps can be used for selective cleaning. In recent decades, biological cle…
Eighteen-Year Farming Management Moderately Shapes the Soil Microbial Community Structure but Promotes Habitat-Specific Taxa
2018
Soil microbes have critical influence on the productivity and sustainability of agricultural ecosystems, yet the magnitude and direction to which management practices affect the soil microbial community remain unclear. This work aimed to examine the impacts of three farming systems, conventional grain cropping (CON), organic grain cropping (ORG), and grain cropping-pasture rotation (ICL), on the soil microbial community structure and putative gene abundances of N transformations using high-throughput 16S rRNA gene and ITS sequencing approaches. Two additional systems, a forest plantation (PF) and an abandoned agricultural field subject to natural succession (SUC), were also included for bet…
Large Blooms of Bacillales (Firmicutes) Underlie the Response to Wetting of Cyanobacterial Biocrusts at Various Stages of Maturity.
2018
ABSTRACT Biological soil crusts (biocrusts) account for a substantial portion of primary production in dryland ecosystems. They successionally mature to deliver a suite of ecosystem services, such as carbon sequestration, water retention and nutrient cycling, and climate regulation. Biocrust assemblages are extremely well adapted to survive desiccation and to rapidly take advantage of the periodic precipitation events typical of arid ecosystems. Here we focus on the wetting response of incipient cyanobacterial crusts as they mature from “light” to “dark.” We sampled a cyanobacterial biocrust chronosequence before (dry) and temporally following a controlled wetting event and used high-throug…
External Influences on Invertebrate Brain Histamine and Related Compounds via an Automated Derivatization Method for Capillary Electrophoresis.
2017
8 pages; International audience; Histamine has been shown to modulate visual system and photic behavior in arthropods. However, few methods are available for the direct quantification of histamine and its precursor and metabolites in arthropod brain. In this work, a method for the separation of histamine, its precursor histidine, and its metabolite N-methyl-histamine from brain extracts of a freshwater crustacean has been developed using capillary electrophoresis with laser-induced fluorescence detection. Molecules were tagged on their primary amine function with naphthalene-2,3-dicarboxaldehyde, but derivatized histamine and N-methyl-histamine exhibited poor stability in contrast to deriva…
Characterization of crustacyanin-A2 subunit as a component of the organic matrix of gastroliths from the crayfish Cherax quadricarinatus.
2009
AbstractLike the lobsters, some terrestrial crabs and other crayfishes, the Australian red claw crayfish, Cherax quadricarinatus, elaborates in its stomach wall calcium storage structures called gastroliths. For understanding the cyclic elaboration and stabilization of these amorphous calcified structures, we studied the organic matrix (OM) of these paired biomineralizations. After decalcification with acetic acid, we analysed the proteinaceous components of an acetic acid-insoluble fraction by two-dimensional electrophoresis. Nine spots were digested by trpsin and the tryptic peptides were sequenced by nanoLC-nanoESI-MS/MS mass spectrometry. About 100 peptidic sequences were compared to se…
Comparison of odour sensory profiles performed by two independent trained panels following the same descriptive analysis procedures
2000
Odour sensory profiling of 28 associations of cheese ripening micro-organisms was performed by two panels of 10 assessors on two different sites. Sample preparation, training protocols and references, tasting procedures and scoring were similar in the two laboratories. Panel 2 used 10 attributes and panel 1 used these terms plus 4 extra descriptors. Analysis of variance and multivariate methods (canonical variate analysis, generalised procrustes analysis and STATIS) exhibited differences between assessors within a panel and between panels concerning the use of the scoring scale and the strength of product discrimination by attribute. Panel 1 was more sensitive to fruity notes and panel 2 to…
Fishing pressure impacts the abundance gradient of European lobsters across the borders of a newly established marine protected area
2019
Marine protected areas (MPAs) are considered viable fisheries management tools due to their potential benefits of adult spillover and recruitment subsidy to nearby fisheries. However, before–after control–impact studies that explore the biological and fishery effects of MPAs to surrounding fisheries are scarce. We present results from a fine-scale spatial gradient study conducted before and after the implementation of a 5 km 2 lobster MPA in southern Norway. A significant nonlinear response in lobster abundance, estimated as catch-per-unit-effort (CPUE) from experimental fishing, was detected within 2 years of protection. After 4 years, CPUE values inside the MPA had increased by a magnitu…
Widening of Hydrous Shear Zones During Incipient Eclogitization of Metastable Dry and Rigid Lower Crust—Holsnøy, Western Norway
2021
The partially eclogitized crustal rocks on Holsnøy in the Bergen Arcs, Norway, indicate that eclogitization is caused by the interplay of brittle and ductile deformation promoted by fluid infiltration and fluid‐rock interaction. Eclogitization generated an interconnected network of millimeter‐to‐kilometer‐wide hydrous eclogite‐facies shear zones, which presumably caused transient weakening of the mechanically strong lower crust. To decipher the development of those networks, we combine detailed lithological and structural mapping of two key outcrops with numerical modeling. Both outcrops are largely composed of preserved granulite with minor eclogite‐facies shear zones, thus representing th…
Are epizoites biological indicators of a western Mediterranean striped dolphin die-off?
1994
During a die-off of Mediterranean striped dolphins Stenella coeruleoalba in 1990-91, 82 individuals stranded on the Spanish coast were examined for crustacean ectoparasites and epizoites. Six species were detected: Syncyarnus aequus, PenneUa sp., Xenobalanus globicipitis, Conchoderma virgatum, Lepas pectinata and Lepas cf. hillii. The barnacles L. pectinata and L. cf. hillii are reported here for the first time on cetaceans; they were attached to the teeth. C. virgaturn was also found on the teeth; this is an unusual attachment on cetaceans. X. globicipitis showed a higher prevalence on the dolphins studied than on those stranded in the same months before (1980 to 1990) and after (1991 to 1…
Ecologia d'ostracodes simbionts (Entocytheridae) de carrancs invasors a Europa
2014
Els entocitèrids són una família d'ostracodes (Crustacea) ectosimbionts (bàsicament comensals) d'altres crustacis, majoritàriament decàpodes d'aigua dolça. Gran part de les espècies d'entocitèrids són originàries d'Amèrica del Nord i Central, i d'Oceania, associades a carrancs de riu americans i australians. No s'han descobert espècies d'entocitèrids en els carrancs de riu natius d'Europa. Les darreres dècades, els carrancs natius europeus s'han vist greument perjudicats per la invasió de carrancs exòtics, degut a fenòmens d'exclusió competitiva i transmissió de simbionts parasitaris. En la present tesi, hem avaluat la presència d'entocitèrids associats a carrancs de riu (natius i exòtics) …