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Concept

Euxinisme

Publications associées (22)

Diagenetic isotope exchange in biocalcites for paleoclimate reconstruction

Deyanira Graciela Cisneros Lazaro

The oxygen isotope compositions of fossil biocalcites, such as foraminifera, bivalves, brachiopods, and belemnites have allowed for reconstructions of sea surface and deep ocean temperatures throughout the Phanerozoic and constitute the most important reco ...

EPFL2024

Spatially Explicit Linkages Between Redox Potential Cycles and Soil Moisture Fluctuations

Andrea Rinaldo, Rizlan Bernier-Latmani, Paolo Benettin, Manon Frutschi, Mitra Asadollahi, Simiao Wang, Filippo Miele

Reduction-oxidation cycles measured through soil redox potential (Eh) are associated with dynamic soil microbial activity. Understanding changes in the composition of, and resource use by, soil microbial communities requires Eh predictability under shiftin ...

American Geophysical Union2023

Detritus-hosted methanogenesis sustains the methane paradox in an alpine lake

Damien Bouffard, Oscar Rodrigo Sepúlveda Steiner

Accumulation of methane in oxic waters of lakes and the ocean has been widely reported. Despite the importance for the greenhouse gas budget, mechanistic controls of such "methane paradox" remain elusive. Here, we use a combination of CH4 concentration and ...

American Society of Limnology and Oceanography2022

Active anaerobic methane oxidation and sulfur disproportionation in the deep terrestrial subsurface

Rizlan Bernier-Latmani, Manon Frutschi, Emma Bell

Microbial life is widespread in the terrestrial subsurface and present down to several kilometers depth, but the energy sources that fuel metabolism in deep oligotrophic and anoxic environments remain unclear. In the deep crystalline bedrock of the Fennosc ...

2022

Catalytic effects of photogenerated Fe(II) on the ligand-controlled dissolution of Iron(hydr)oxides by EDTA and DFOB

Janet Gordon Hering

Low bioavailability of iron due to poor solubility of iron(hydr)oxides limits the growth of microorganisms and plants in soils and aquatic environments. Previous studies described accelerated dissolution of iron(hydr)oxides under continuous illumination, b ...

Pergamon-Elsevier Science Ltd2021

Tailoring the redox-active transition metal content to enhance cycling stability in cation-disordered rock-salt oxides

Corsin Battaglia, Chunyang Zhang

Lithium-excess cation-disordered rock-salt oxides (DRXs) are investigated intensively as cathode materials for future lithium-ion batteries combining cationic and anionic redox reactions. However, the lattice oxygen redox can cause severe oxygen release re ...

ELSEVIER2021

Persistence of bioconvection-induced mixed layers in a stratified lake

Alfred Johny Wüest, Damien Bouffard, Oscar Rodrigo Sepúlveda Steiner

In situ observations of biophysical interactions in natural waters typically focus on physical mechanisms influencing biological activity. Yet, biological activity can also drive physical processes in aquatic environments. A community of photoautotrophic, ...

American Society of Limnology and Oceanography2021

In Situ Biostimulation of Cr(VI) Reduction in a Fast-Flowing Oxic Aquifer

Rizlan Bernier-Latmani, Daniel Scott Alessi

Hexavalent chromium is among the most common and hazardous inorganic contaminants in soils and groundwater. A promising in situ bioremediation approach is the delivery of electron donors to stimulate microbially mediated Cr(VI) reduction, producing relativ ...

AMER CHEMICAL SOC2020

Interplay of S and As in Mekong Delta sediments during redox oscillations

Rizlan Bernier-Latmani

The cumulative effects of periodic redox cycling on the mobility of As, Fe, and S from alluvial sediment to groundwater were investigated in bioreactor experiments. Two particular sediments from the alluvial floodplain of the Mekong Delta River were invest ...

2019

Hydrodynamics of a periodically wind‑forced small and narrow stratified basin: a large‑eddy simulation experiment

Alfred Johny Wüest, Damien Bouffard, Hugo Nicolás Ulloa Sánchez, Oscar Rodrigo Sepúlveda Steiner

We report novel results of a numerical experiment designed for examining the basin-scale hydrodynamics that control the mass, momentum, and energy distribution in a daily wind-forced, small thermally-stratified basin. For this purpose, the 3-D Boussinesq e ...

2018

Full-scale evaluation of methane production under oxic conditions in a mesotrophic lake

Sabine Flury McGinnis

Oxic lake surface waters are frequently oversaturated with methane (CH4). The contribution to the global CH4 cycle is significant, thus leading to an increasing number of studies and stimulating debates. Here we show, using a mass balance, on a temperate, ...

Nature Publishing Group2017

Surviving anoxia in marine sediments: The metabolic response of ubiquitous benthic foraminifera (Ammonia tepida)

Anders Meibom, Stéphane Laurent Escrig, Emmanuelle Geslin, Charlotte Madeleine Nicole Lekieffre

High input of organic carbon and/or slowly renewing bottom waters frequently create periods with low dissolved oxygen concentrations on continental shelves and in coastal areas; such events can have strong impacts on benthic ecosystems. Among the meiofauna ...

Public Library of Science2017

Correlated TEM-NanoSIMS investigation of foraminiferal metabolism

Charlotte Madeleine Nicole Lekieffre

Foraminifera are ubiquitous eukaryotic protists inhabiting all types of marine environments. The chemical and isotopic compositions of their carbonate tests are commonly used as proxies for paleo-environmental conditions. However, while foraminifera repres ...

EPFL2017

Oxygen depletion in Lake Geneva

Robert Vincent Schwefel

Low oxygen concentrations remain a global concern for the ecological health of lakes. High nutrient inputs and climate-induced changes in stratification and mixing are anthropogenic threats which largely impact aquatic oxygen budgets and overall ecosystem ...

EPFL2017

Uranium Isotopes Fingerprint Biotic Reduction

Rizlan Bernier-Latmani, Yuheng Wang, Malgorzata Alicja Stylo

Knowledge of paleo-redox conditions in the Earth's history provides a window into events that shaped the evolution of life on our planet. The role of microbial activity in paleo-redox processes remains unexplored due to the inability to discriminate biotic ...

Natl Acad Sciences2015

Redox variations and bioproductivity in the Ediacaran: Evidence from inorganic and organic geochemistry of the Corumba Group, Brazil

Mariluz Bagnoud

Stable isotope ratios combined with elemental compositions and molecular biomass data provide a powerful tool in Neoproterozoic palaeoenvironmental interpretations. Here, we report the results of an extensive organic and inorganic geochemical study perform ...

Elsevier2014

Column studies to assess the effects of climate variables on redox processes during riverbank filtration

Urs von Gunten, Janet Gordon Hering

Riverbank filtration is an established technique used world-wide to produce clean drinking water in a reliable and cost-efficient way. This practice is, however, facing new challenges posed by climate change, as already observed during past heat waves with ...

Elsevier2014

Stable isotope (S, C) chemostratigraphy and hydrocarbon biomarkers in the Ediacaran upper section of Sierras Bayas Group, Argentina

Mariluz Bagnoud

The Neoproterozoic sedimentary successions of the Sierras Bayas Group (SBG) are situated within the Tandilia Belt, Buenos Aires Province, Argentina. The Loma Negra Formation (LNF) from the upper part of the SBG has been investigated using a combination of ...

Elsevier2013

Methane formation and future extraction in Lake Kivu

Alfred Johny Wüest, Natacha Pasche

This chapter summarises the current knowledge on the vertical distribution of methane (CH4) and its formation in Lake Kivu. Additionally, we review the objectives and restrictions under consideration for sustainable extraction (safe, environmentally accept ...

Springer2012

Physical and biogeochemical limits to internal nutrient loading of meromictic Lake Kivu

Alfred Johny Wüest, Natacha Pasche, Beat Mueller

Lake Kivu is one of the large African Rift lakes situated between the Democratic Republic of the Congo and Rwanda. In its permanently stratified hypolimnion, unusually high methane concentrations have increased further in recent decades. Because methanogen ...

American Society of Limnology and Oceanography2009