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1. Origin and fate of dissolved inorganic carbon in a karst groundwater fed peatland using δ13CDIC

Author

Alexandre Lhosmot, Marc Steinmann, Philippe Binet, Laure Gandois, Jean-Sébastien Moquet, Vanessa Stefani, Marie-Laure Toussaint, Anne Boetsch, Christophe Loup, Valentin Essert, Guillaume Bertrand, Laboratoire Chrono-environnement (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Institut des Sciences de la Terre d'Orléans - UMR7327 (ISTO), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Biogéosystèmes Continentaux - UMR7327, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Bourgogne Franche-Comté Region (CRITICAL PEAT project, Acceuil de Nouvelle Equipe de Recherche Agreement n°2019-Y09069), and SNO Tourbières

Subjects
Geochemistry and Petrology, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, [SDE.MCG]Environmental Sciences/Global Changes, Geology, Peatland Carbon-13 Jura Mountains, [SDU.STU.HY]Sciences of the Universe [physics]/Earth Sciences/Hydrology, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment
Abstract

International audience; Continental hydrosystems and in particular peatlands play an important role in the carbon cycle of the Critical Zone (CZ). Peatlands are important sinks for organic carbon and have therefore been extensively studied. However, peatlands are not only important for the fate of organic carbon, but they also affect the cycle of Dissolved Inorganic Carbon (DIC) of the peatland and the surrounding watershed. The fate of DIC is particularly complex in peatlands in limestone-dominated regions, because bicarbonate concentrations in surface and groundwater are high and the interaction between peatlands and surrounding hydrosystems are facilitated by the presence of highly permeable karst aquifers. In the present paper we study the origin and the fractionation of DIC in a peatland located on top of a karst aquifer. The study is based on hydrochemical and isotopic (δ13CDIC) data from samples recovered during 2 campaigns (low flow, high flow) at various depths within the Forbonnet peatland (Jura Mountains, eastern France), at the peatland outlet and at adjacent karst springs representing the underlying aquifer. In order to evaluate secondary fractionation processes, the measured δ13CDIC compositions were compared to modeled values considering the origin of DIC and potentially associated fractionation and speciation processes. The main results are: (1) DIC is lost at the bog surface by CO2 outgassing. (2) The δ13CDIC compositions of deep catotelm pore waters from the bog were much heavier than the modeled values. We relate this discrepancy to methanogenesis and show that this process is favored by reduced conditions at pH ~ 6 and a HCO3 − content of ~1 mmol/L, most probably due to punctual groundwater inflows at the base of the bog. Finally, contrasted δ13CDIC compositions between the bog and the fen of the peatland reveal an additional ecohydrological control on DIC speciation.

Published
2023
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2. Original detection methods for tephra layers and cryptotephras

Author

Christophe Loup, Gwénolé Jouannic, Gilles Bossuet, Anne-Lise Develle, Eric Delabrousse, Anne-Véronique Walter-Simonnet, Walter-Simonnet, Anne-Véronique, Rocha R., Pais J ., Kullberg J.C., Finney S., Groupement de Recherche Eau, Sol, Environnement ( GRESE ), Université de Limoges ( UNILIM ), Laboratoire Chrono-environnement ( LCE ), Université Bourgogne Franche-Comté ( UBFC ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Franche-Comté ( UFC ), Environnements, Dynamiques et Territoires de la Montagne ( EDYTEM ), Université Savoie Mont Blanc ( USMB [Université de Savoie] [Université de Chambéry] ) -Centre National de la Recherche Scientifique ( CNRS ), Centre Hospitalier Régional Universitaire [Besançon] ( CHRU Besançon ), Groupement de Recherche Eau, Sol, Environnement (GRESE), Université de Limoges (UNILIM), Laboratoire Chrono-environnement - CNRS - UBFC (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Environnements, Dynamiques et Territoires de la Montagne (EDYTEM), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre Hospitalier Régional Universitaire de Besançon (CHRU Besançon), Rocha R., Pais J ., Kullberg J.C., and Finney S.

Subjects
geography, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, Sediment, Mineralogy, Sampling (statistics), [ SDU.STU.VO ] Sciences of the Universe [physics]/Earth Sciences/Volcanology, 010502 geochemistry & geophysics, 01 natural sciences, Volcanic glass, Sedimentary structures, Volcano, 13. Climate action, Magma, [SDU.STU.VO] Sciences of the Universe [physics]/Earth Sciences/Volcanology, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, Sedimentary rock, Tephra, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract

The building of independent and accurate chronologies is crucial to correlate environmental and climatic changes as reflected in biotic as well as abiotic signals from continental lacustrine sediments. The use of tephras, which are instantaneous and synchronous atmospheric deposits, as time-parallel markers, allows independent, high-precision regional and inter-regional correlations to be established. The development of effective, rapid methods to detect tephra layers in sedimentary records of various compositions is a challenge. Many traditional methods for the detection of tephra layers, such as regular sampling or magnetic susceptibility measurements, have shown their limits. Regular sampling takes a long time, and finding tephra layers is an uncertain process. Moreover, magnetic susceptibility is ineffective when tephra layers are composed of volcanic glass shards of differentiated magma composition. This study proposes three original methods to detect tephra layers: XRF, CT imaging, and quantitative sulphur analysis. XRF enables tephra layer composition elements and sediment to be differentiated. CT imaging may be used to observe 3D sedimentary structures. Sulphur analysis allows the environmental impact of degassing in volcanic eruptions to be examined. These methods can be used successfully to detect tephra layers of various chemical compositions in both peaty and carbonated deposits.

Published
2013

3. Improvement of porphyrin cellular delivery and activity by conjugation to a carrier peptide

Author

Christophe Loup, Mariana Marin, Frédéric Heitz, Pascal Bigey, Marc Piechaczyk, Nathalie Galéotti, Bernard Meunier, Laurent Chaloin, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut de Génétique Moléculaire de Montpellier (IGMM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Unité Mixte de Recherches sur les Herbivores - UMR 1213 (UMRH), VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Institut National de la Recherche Agronomique (INRA), Unité de Recherches sur les Herbivores (URH), and Institut National de la Recherche Agronomique (INRA)

Subjects
Cell Membrane Permeability, Metalloporphyrins, Molecular Sequence Data, Biomedical Engineering, Pharmaceutical Science, Bioengineering, Peptide, Antineoplastic Agents, 010402 general chemistry, 01 natural sciences, Substrate Specificity, chemistry.chemical_compound, Mice, Surface-Active Agents, Cleave, Tumor Cells, Cultured, Animals, Humans, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Amino Acid Sequence, Pharmacology, chemistry.chemical_classification, Nuclease, Drug Carriers, Binding Sites, Deoxyribonucleases, biology, 010405 organic chemistry, Organic Chemistry, DNA, Neoplasm, Porphyrin, In vitro, 0104 chemical sciences, nuclear-localization sequence gene-transfer synthetic peptides mammalian-cells signal peptide DNA cleavers in-vitro cyclin-a cleavage efficient, chemistry, biology.protein, Biophysics, Drug carrier, Peptides, DNA, Cell Division, Biotechnology, Conjugate
Abstract

The chemical nuclease metalloporphyrin (manganese(III) porphyrin) can cleave DNA irreversibly and can thus constitute a potential antitumor drug. However, these molecules show low permeability to cell surface membranes. We report here the conjugation of an amphipathic carrier peptide to improve considerably its cellular delivery. The metalloporphyrin-peptide conjugate can be internalized by cells within only 5 min of incubation with a yield as high as 80%. Furthermore, the metalloporphyrin-peptide conjugate is able to cleave in vitro high or low molecular weight DNA to the same extend as metalloporphyrin alone without affecting the sequence-specific cleaving activity of the porphyrin. The conjugate is 100-fold more efficient at inducing tumor cells death than the free metalloporphyrin via a mechanism involving genomic DNA cleavage. The results are promising for further therapeutic applications with antitumor drugs such as metalloporphyrin, and also with other existing drugs by using a carrier peptide system in order to improve the cellular uptake of such molecules.

Published
2001
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