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9 results on '"Stefan Lambert"'

1. Assessment of microbial communities from cold mine environments and subsequent enrichment, isolation and characterization of putative antimony- or copper-metabolizing microorganisms

Author

Francisca Prieto-Fernández, Stefan Lambert, and Katharina Kujala

Subjects
metal, metalloid, cold, copper, antimony, enrichment, Microbiology, QR1-502
Abstract

Mining activities, even in arctic regions, create waste materials releasing metals and metalloids, which have an impact on the microorganisms inhabiting their surroundings. Some species can persist in these areas through tolerance to meta(loid)s via, e.g., metabolic transformations. Due to the interaction between microorganisms and meta(loid)s, interest in the investigation of microbial communities and their possible applications (like bioremediation or biomining) has increased. The main goal of the present study was to identify, isolate, and characterize microorganisms, from subarctic mine sites, tolerant to the metalloid antimony (Sb) and the metal copper (Cu). During both summer and winter, samples were collected from Finnish mine sites (site A and B, tailings, and site C, a water-treatment peatland) and environmental parameters were assessed. Microorganisms tolerant to Sb and Cu were successfully enriched under low temperatures (4°C), creating conditions that promoted the growth of aerobic and fermenting metal(loid) tolerating or anaerobic metal(loid) respiring organism. Microbial communities from the environment and Sb/Cu-enriched microorganisms were studied via 16S rRNA amplicon sequencing. Site C had the highest number of taxa and for all sites, an expected loss of biodiversity occurred when enriching the samples, with genera like Prauserella, Pseudomonas or Clostridium increasing their relative abundances and others like Corynebacterium or Kocuria reducing in relative abundance. From enrichments, 65 putative Sb- and Cu-metabolizing microorganisms were isolated, showing growth at 0.1 mM to 10 mM concentrations and 0°C to 40°C temperatures. 16S rRNA gene sequencing of the isolates indicated that most of the putative anaerobically Sb-respiring tolerators were related to the genus Clostridium. This study represents the first isolation, to our knowledge, of putative Sb-metabolizing cold-tolerant microorganisms and contributes to the understanding of metal (loid)-tolerant microbial communities in Arctic mine sites.

Published
2024
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2. Lyapunov-based observer design for steam boilers

Author

Markus Tranninger, Stefan Lambert Hölzl, Richard Seeber, Martin Horn, and Robert Bauer

Subjects
Lyapunov function, 0209 industrial biotechnology, State variable, Observer (quantum physics), business.industry, Computer science, 020208 electrical & electronic engineering, Automotive industry, ComputerApplications_COMPUTERSINOTHERSYSTEMS, Ranging, 02 engineering and technology, Power (physics), symbols.namesake, Extended Kalman filter, 020901 industrial engineering & automation, Control and Systems Engineering, Air conditioning, Control theory, 0202 electrical engineering, electronic engineering, information engineering, symbols, business
Abstract

Steam boilers are widely used in industrial applications ranging from air conditioning to power plants. Advanced control schemes for such boilers require the knowledge of internal state variables, which are not always measurable. This paper proposes a new observer for steam boilers whose construction builds on a special state variable choice and a Lyapunov-based design of the observer gains. Tuning insight is gained from an oscillator-like structure of the (linearised) observer error dynamics. Comparisons to an extended Kalman filter in simulations and on experimental data from a small-scale automotive application demonstrate the performance of the proposed approach.

Published
2020
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3. In situ community dynamics influences the temperature- and light- dependent succession of seasonal phytoplankton

Author

Margot Tragin, François-Yves Bouget, Jean-Claude Lozano, Stefan Lambert, Laboratoire d'Océanographie Microbienne (LOMIC), Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire océanologique de Banyuls (OOB), and Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
In situ, Mamiellophyceae, Ecological succession, microcosms, diatoms, 03 medical and health sciences, Mediterranean sea, Phytoplankton, 14. Life underwater, Tragin et al. -Seasonal Microcosms -p. 2 Phytoplankton, Picoplankton, 030304 developmental biology, 0303 health sciences, biology, seasonality, 030306 microbiology, Ecology, Archaeplastida, Chlorodendrophyceae, temperature, biology.organism_classification, metabarcoding, [SDE]Environmental Sciences, Environmental science, light, Microcosm, Bloom
Abstract

Temperature and light play a crucial role in regulating phytoplankton blooms in the Ocean. To assess the importance of these two parameters experimentally, microcosms were conducted on seven picoplankton communities (

Published
2021
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4. Seasonal marine microorganisms change neighbours under contrasting environmental conditions

Author

Jean-Claude Lozano, Stefan Lambert, François-Yves Bouget, and Pierre E. Galand

Subjects
Ecological niche, 0303 health sciences, Nutrient cycle, Picoeukaryote, biology, Bacteria, 030306 microbiology, Ecology, Carbon sequestration, Plankton, biology.organism_classification, Microbiology, Archaea, 03 medical and health sciences, Extreme weather, Ecosystem, Seasons, Picoplankton, Ecology, Evolution, Behavior and Systematics, 030304 developmental biology
Abstract

Marine picoplankton contribute to global carbon sequestration and nutrient recycling. These processes are directly related to the composition of communities, which in turn depends on microbial interactions and environmental forcing. Under regular seasonal cycles, marine communities show strong predictable patterns of annual re-occurrences, but little is known about the effect of environmental perturbation on their organization. The aim of our study was to investigate the co-occurrence patterns of planktonic picoeukaryote, bacteria and archaea under contrasting environmental conditions. The study was designed to have high sampling frequency that could match both the biological rhythm of marine microbes and the short time scale of extreme weather events. Our results show that microbial networks changed from year to year depending on conditions. In addition, individual taxa became less interconnected and changed neighbours, which revealed an unfaithful relationship between marine microorganisms. This unexpected pattern suggests possible switches between organisms that have similar specific functions, or hints at the presence of organisms that share similar environmental niches without interacting. Despite the observed annual changes, the time series showed re-occurring communities that appear to recover from perturbations. Changing co-occurrence patterns between marine microorganisms may allow the long-term stability of ecosystems exposed to contrasting meteorological events.

Published
2020

5. Optimization-Based Iterative Learning Speed Control for Vehicle Test Procedures

Author

Richard Seeber, Stefan Lambert Hölzl, Robert Bauer, and Martin Horn

Subjects
Scheme (programming language), 0209 industrial biotechnology, Electronic speed control, Yield (engineering), Optimization problem, Automatic control, Computer science, business.industry, 020208 electrical & electronic engineering, Iterative learning control, Automotive industry, 02 engineering and technology, 020901 industrial engineering & automation, Control and Systems Engineering, Control theory, Position (vector), 0202 electrical engineering, electronic engineering, information engineering, business, computer, computer.programming_language, TRACE (psycholinguistics)
Abstract

Procedures for measuring the emissions of automotive vehicles typically include a speed trace that the driver has to track within prescribed tolerances. For development purposes, following this trace by means of automatic control is desirable in order to minimize costs. In this contribution, an iterative learning scheme is proposed that iteratively improves a feed-forward control signal. This is done by means of an optimization problem that takes the speed tolerances into account in the form of constraints. Experimental results obtained with a vehicle on a Road-to-Rig (R2R) test bed for a part of the Worldwide Harmonized Light Vehicle Test Procedure (WLTP) are presented and compared to results of a pure PI control scheme. After very few iterations, both tolerance violations and sudden changes of the pedal position are eliminated, yielding a significantly improved driving behavior.

Published
2019
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7. Rhythmicity of coastal marine picoeukaryotes, bacteria and archaea despite irregular environmental perturbations

Author

Margot Tragin, Stefan Lambert, Jean-Claude Lozano, Daniel Vaulot, François-Yves Bouget, Jean-François Ghiglione, Pierre E. Galand, Adaptation Biologique et Vieillissement = Biological Adaptation and Ageing (B2A), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Diversité et Interactions au sein du Plancton Océanique (DIPO), Adaptation et diversité en milieu marin (AD2M), Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), ECOlogy of MArine Plankton (ECOMAP), Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Océanographie Microbienne (LOMIC), Observatoire océanologique de Banyuls (OOB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Adaptation et diversité en milieu marin (ADMM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire océanologique de Banyuls (OOB)

Subjects
[SDV]Life Sciences [q-bio], Microbiology, Article, 03 medical and health sciences, Mediterranean sea, Phytoplankton, Mediterranean Sea, Ecosystem, Seawater, 14. Life underwater, Autotroph, Ecology, Evolution, Behavior and Systematics, ComputingMilieux_MISCELLANEOUS, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, 030304 developmental biology, Micromonas, Ecological niche, 0303 health sciences, biology, Bacteria, 030306 microbiology, Ecology, Eukaryota, biology.organism_classification, Archaea, [SDE]Environmental Sciences, Seasons, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Bay
Abstract

International audience; Seasonality in marine microorganisms has been classically observed in phytoplankton blooms, and more recently studied at the community level in prokaryotes, but rarely investigated at the scale of individual microbial taxa. Here we test if specific marine eukaryotic phytoplankton, bacterial and archaeal taxa display yearly rhythms at a coastal site impacted by irregular environmental perturbations. Our seven-year study in the Bay of Banyuls (North Western Mediterranean Sea) shows that despite some fluctuating environmental conditions, many microbial taxa displayed significant yearly rhythms. The robust rhythmicity was found in both autotrophs (picoeukaryotes and cyanobacteria) and heterotrophic prokaryotes. Sporadic meteorological events and irregular nutrient supplies did, however, trigger the appearance of less common non-rhythmic taxa. Among the environmental parameters that were measured, the main drivers of rhythmicity were temperature and day length. Seasonal autotrophs may thus be setting the pace for rhythmic heterotrophs. Similar environmental niches may be driving seasonality as well. The observed strong association between Micromonas and SAR11, which both need thiamine precursors for growth, could be a first indication that shared nutritional niches may explain some rhythmic patterns of co-occurrence.

Published
2019
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9. Blue-light dependent reactive oxygen species formation by Arabidopsis cryptochrome may define a novel evolutionarily conserved signaling mechanism

Author

Laurent Consentino, Françoise Corbineau, Nathalie Jourdan, Pablo R. Castello, Carlos F. Martino, Margaret Ahmad, Stefan Lambert, Pierre-Etienne Bouchet, Jacques Witczak, Alain d'Harlingue, Mohamed A. El-Esawi, Adaptation Biologique et Vieillissement = Biological Adaptation and Ageing (B2A), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Department of Biomedical Engineering, Florida Institute of Technology [Melbourne], Facultad de Ciencias Exactas y Naturales, Universidad de Belgrano, Botany Department, Tanta University, Laboratoire de Biologie du Développement (LBD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Xavier University, Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie Paris Seine (IBPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Photobiologie (PHOTO), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Biologie Paris Seine (IBPS), and Administateur, HAL Sorbonne Université

Subjects
0106 biological sciences, PHOTORECEPTOR, Arabidopsis thaliana, Light, Physiology, [SDV]Life Sciences [q-bio], Arabidopsis, Plant Science, medicine.disease_cause, 01 natural sciences, Cryptochrome, Sf9 Cells, oxidative stress, [SDV.BV] Life Sciences [q-bio]/Vegetal Biology, CRYPTOCHROME, OXIDATIVE STRESS, chemistry.chemical_classification, Recombination, Genetic, 0303 health sciences, biology, Cell Death, Protoplasts, Bioquímica y Biología Molecular, Biological Evolution, Cell biology, REACTIVE OXYGEN SPECIES (ROS) SIGNALING, Photomorphogenesis, cryptochrome, CIENCIAS NATURALES Y EXACTAS, Signal Transduction, Subcellular Fractions, Programmed cell death, PHOTOMORPHOGENESIS, Cell Survival, [SDV.BC]Life Sciences [q-bio]/Cellular Biology, Ciencias Biológicas, 03 medical and health sciences, medicine, reactive oxygen species (ROS) signaling, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, [SDV.BC] Life Sciences [q-bio]/Cellular Biology, Transcription factor, 030304 developmental biology, Reactive oxygen species, Arabidopsis Proteins, fungi, ARABIDOPSIS THALIANA, biology.organism_classification, photoreceptor, photomorphogenesis, Cryptochromes, Oxygen, chemistry, Reactive Oxygen Species, Oxidative stress, 010606 plant biology & botany
Abstract

Cryptochromes are widespread blue-light absorbing flavoproteins with important signaling roles. In plants they mediate de-etiolation, developmental and stress responses resulting from interaction with downstream signaling partners such as transcription factors and components of the proteasome. Recently, it has been shown that Arabidopsis cry1 activation by blue light also results in direct enzymatic conversion of molecular oxygen (O2) to reactive oxygen species (ROS) and hydrogen peroxide (H2O2) in vitro. Here we explored whether direct enzymatic synthesis of ROS by Arabidopsis cry1 can play a physiological role in vivo. ROS formation resulting from cry1 expression was measured by fluorescence assay in insect cell cultures and in Arabidopsis protoplasts from cryptochrome mutant seedlings. Cell death was determined by colorimetric assay. We found that ROS formation results from cry1 activation and induces cell death in insect cell cultures. In plant protoplasts, cryptochrome activation results in rapid increase in ROS formation and cell death. We conclude that ROS formation by cryptochromes may indeed be of physiological relevance and could represent a novel paradigm for cryptochrome signaling. Fil: Consentino, Laurent. Université Pierre et Marie Curie; Francia Fil: Lambert, Stefan. Université Pierre et Marie Curie; Francia Fil: Martino, Carlos. Université Pierre et Marie Curie; Francia. University of Florida; Estados Unidos Fil: Jourdan, Nathalie. Université Pierre et Marie Curie; Francia Fil: Bouchet, Pierre Etienne. Université Pierre et Marie Curie; Francia Fil: Witczak, Jacques. Université Pierre et Marie Curie; Francia Fil: Castello, Pablo Raul. Universidad de Belgrano. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Université Pierre et Marie Curie; Francia Fil: El-Esawi, Mohamed. Université Pierre et Marie Curie; Francia. Tanta University; Egipto Fil: Corbineau, Francoise. Université Pierre et Marie Curie; Francia Fil: d'Harlingue, Alain. Université Pierre et Marie Curie; Francia Fil: Ahmad, Margaret. Université Pierre et Marie Curie; Francia. Universidad Xavier; Estados Unidos

Published
2014
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