299 results on '"P.-P. Crépin"'
Search Results
2. Corrected thermodynamics of nonlinear magnetic-charged black hole surrounded by perfect fluid dark matter
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Ndongmo, Ragil Brand Tsafack, Mahamat, Saleh, Bouetou, Thomas, Tabi, Conrad Bertrand, and Kofané, Timoléon Crépin
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General Relativity and Quantum Cosmology - Abstract
In this paper, we investigate the influence of perfect fluid dark matter and quantum corrections on the thermodynamics of non-linear magnetic-charged black hole. We consider the metric of the static non-linear magnetic-charged black hole in the background of perfect fluid dark matter. Starting with the black hole temperature and the corrected entropy, we use the event horizon propriety in order to find the temperature, and based on the surface gravity definition, we find the uncorrected entropy. However, using the definition of the corrected entropy due to thermal fluctuation, we find and plot the entropy of the black hole. We find that the entropy is highly affected for smaller non-linear magnetic-charged black holes. Afterwards, we study the thermodynamic stability of the black hole by computing and plotting the evolution of heat capacity. The results show that second-order phase transition occurs, which appears more later as the dark matter parameter decreases, and leads the black hole to move from the stable phase to the unstable phase. Furthermore, we show that the heat capacity for smaller black holes are also affected, since it appears not being only an increasing function., Comment: 10 pages, 5 figures
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- 2023
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3. Titanic lessons for Spaceship Earth to account for human behavior in institutional design
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Lindahl, Therese, Anderies, John M., Crépin, Anne-Sophie, Jónás, Krisztina, Schill, Caroline, Cárdenas, Juan Camilo, Folke, Carl, Hofstede, Gert Jan, Janssen, Marco A., Mathias, Jean-Denis, and Polasky, Stephen
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- 2024
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4. Effects of psychological stress on the emission of volatile organic compounds from the skin
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Lucchi, Géraldine, Crépin, Marine, Chambaron, Stéphanie, Peltier, Caroline, Gilbert, Laura, Guéré, Christelle, and Vié, Katell
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- 2024
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5. Cesium atoms in cryogenic argon matrix
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Battard, Thomas, Lahs, Sebastian, Crépin, Claudine, and Comparat, Daniel
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Physics - Atomic Physics - Abstract
This paper presents both experimental and theoretical investigations into the spectroscopy of dilute cesium (Cs) atoms within a solid argon (Ar) matrix at cryogenic temperatures. This system is relevant for matrix isolation spectroscopy and in particular for recently proposed methods for investigating phenomena that extend beyond the standard model of particle physics. We record absorption spectra at various deposition temperatures and examine the evolution of these spectra post-deposition with respect to temperature changes. Taking advantage of Cs-Ar and Ar-Ar pairwise interaction potentials, we conduct a stability study of trapping sites, which indicates a preference for T$_{\rm d}$ (tetrahedral, 4 vacancies) and O$_{\rm h}$ (cubic, 6 vacancies) symmetries. By implementing a mean-field analysis of the long-range Cs(6s,6p)-Ar-Ar triple dipole interaction, combined with a temperature-dependent shift in zero point energy, we propose effective Cs(6s,6p)-Ar pairwise potentials. Upon integrating these pairwise potentials with spin-orbit coupling, we achieve a satisfactory agreement between the observed and simulated absorption line positions. The observed line broadening is reasonably well reproduced by a semi-classical thermal Monte Carlo approach based on Mulliken-type differences between excited and ground potential curves. Additionally, we develop a simple, first-order crystal field theory featuring only 6 interaction mode coordinates. It uses the reflection approximation and incorporates quantized (phonon) normal modes. This produces a narrow triplet structure but not the observed amount of splitting.
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- 2023
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6. Dissipative light bullets in a doped and weakly nonlocal optical fiber
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Ngon, Ghislaine Flore Kabadiang, Tabi, Conrad Bertrand, and Kofané, Timoléon Crépin
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Physics - Optics ,Nonlinear Sciences - Pattern Formation and Solitons - Abstract
The letter introduces an extended (3+1)-dimensional [(3+1)D] nonlocal cubic complex Ginzburg-Landau equation describing the dynamics of dissipative light bullets in optical fiber amplifiers under the interplay between dopants and a spatially nonlocal nonlinear response. The model equation includes the effects of fiber dispersion, linear gain, nonlinear loss, fiber nonlinearity, atomic detuning, linear and nonlinear diffractive transverse effects, and nonlocal nonlinear response. A system of coupled ordinary differential equations for the amplitude, temporal, and spatial pulse widths and position of the pulse maximum, unequal wavefront curvatures, chirp parameters, and phase shift is derived using the variational technique. A stability criterion is established, where a domain of dissipative parameters for stable steady-state solutions is found. Direct integration of the proposed nonlocal evolution equation is performed, which allows us to investigate the evolution of the Gaussian beam along a doped nonlocal optical fiber, showing stable self-organized dissipative spatiotemporal light bullets.
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- 2023
7. Titanic lessons for Spaceship Earth to account for human behavior in institutional design
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Therese Lindahl, John M. Anderies, Anne-Sophie Crépin, Krisztina Jónás, Caroline Schill, Juan Camilo Cárdenas, Carl Folke, Gert Jan Hofstede, Marco A. Janssen, Jean-Denis Mathias, and Stephen Polasky
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Meteorology. Climatology ,QC851-999 ,Environmental sciences ,GE1-350 - Abstract
Abstract Combating environmental degradation requires global cooperation. We here argue that institutional designs for such efforts need to account for human behavior. The voyage of the Titanic serves as an analogous case to learn from, and we use behavioral insights to identify critical aspects of human behavior that serve as barriers or opportunities for addressing the challenges we face. We identify a set of public goods that may help us mitigate identified negative aspects of human behavior, while leveraging the positive aspects: standards and best practices, mechanisms for large-scale coordination, and curation of information to raise awareness and promote action. We use existing international organizations, providing at least one of these capacities, as cases to learn from before applying our insights to existing institutional solutions for global environmental protection. We identify institutional design features that, if adapted to better account for human behavior, could lead to more effective institutional solutions.
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- 2024
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8. Supercontinuum generation of Airy pulses in a silicon-on-insulator optical waveguide including third-harmonic generation and negative-frequency Kerr terms
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Boukar, Souang Kemedane, Mandeng Mandeng, Lucien, Heuteu, Crépin, and Tchawoua, Clément
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- 2024
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9. Modulation instability gain and localized waves by modified Frenkel-Kontorova model of higher order nonlinearity
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Houwe, Alphonse, Abbagari, Souleymanou, Akinyemi, Lanre, Doka, Serge Yamigno, and Crepin, Kofane Timoleon
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Nonlinear Sciences - Pattern Formation and Solitons ,Mathematics - Analysis of PDEs ,Mathematics - Numerical Analysis - Abstract
In this paper, modulation instability and nonlinear supratransmission are investigated in a one-dimensional chain of atoms using cubic-quartic nonlinearity coefficients. As a result, we establish the discrete nonlinear evolution equation by using the multi-scale scheme. To calculate the modulation instability gain, we use the linearizing scheme. Particular attention is given to the impact of the higher nonlinear term on the modulation instability. Following that, full numerical integration was performed to identify modulated wave patterns, as well as the appearance of a rogue wave. Through the nonlinear supratransmission phenomenon, one end of the discrete model is driven into the forbidden bandgap. As a result, for driving amplitudes above the supratransmission threshold, the solitonic bright soliton and modulated wave patterns are satisfied. An important behavior is observed in the transient range of time of propagation when the bright solitonic wave turns into a chaotic solitonic wave. These results corroborate our analytical investigations on the modulation instability and show that the one-dimensional chain of atoms is a fruitful medium to generate long-lived modulated waves.
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- 2023
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10. Genome sequences of 36,000- to 37,000-year-old modern humans at Buran-Kaya III in Crimea
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Bennett, E. Andrew, Parasayan, Oğuzhan, Prat, Sandrine, Péan, Stéphane, Crépin, Laurent, Yanevich, Alexandr, Grange, Thierry, and Geigl, Eva-Maria
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- 2023
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11. Effects of psychological stress on the emission of volatile organic compounds from the skin
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Géraldine Lucchi, Marine Crépin, Stéphanie Chambaron, Caroline Peltier, Laura Gilbert, Christelle Guéré, and Katell Vié
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Medicine ,Science - Abstract
Abstract Thirty-five women were included in a clinical study to characterize the volatile organic compounds (VOCs) emitted by the skin during exposure to psychological stress. An original silicon-based polymeric phase was used for VOC sampling on the forehead before and after stress induction. Cognitive stress was induced using specialized software that included a chronometer for semantic and arithmetic tasks. Assessment of stress was monitored using a State-trait anxiety inventory questionnaire, analysis of participants’ verbal expressions and clinical measurements. Identification and relative quantification of VOCs were performed by gas chromatography-mass spectrometry. Stress induction was validated by a significant increase in state-anxiety as indicated by the questionnaire, modifications in electrodermal activity measurements and the expression of stress verbatims. In parallel, a sebum production increase and a skin pH decrease were observed. A total of 198 VOCs with different potential sources were identified. They were categorized in 5 groups: probable cosmetic composition, VOCs produced by the body or its microbiota, environmental origin, and dietary intake. In our qualitative statistical approach, three VOCs were found to be correlated with stress induction and 14 compounds showed significance in the paired Wilcoxon test. Fatty-acyls derived from lipids were predominantly identified as well as ethylbenzenes.
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- 2024
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12. Influence of some environmental variables on the diversity and distribution of aquatic oligochaetes (Clitellata: Annelida) in the Nyong estuary (Atlantic coast, southern Cameroon)
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Paul Alain Nana, Raoul Polycarpe Tuekam Kayo, Fils Mamert Onana, Ernest Ohandja Nomo, Anselme Crépin Mama, and Zéphyrin Fokam
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Oligochaete annelids ,Tubificida ,Haplotaxida ,Lumbriculida ,Abiotic gradients ,Science - Abstract
Tropical estuarine ecosystems are subject to strong anthropogenic pressures, with the direct consequence of declining or lost biodiversity. An essential and little-known biological component of these estuarine ecosystems is the population of oligochaete annelids, which play an indispensable role in energy transfer and the biodegradation of organic and chemical compounds. This study sheds light on the diversity and structure of oligochaetes in the Nyong estuary under the influence of some abiotic parameters. Based on hydrobiological standard techniques, 1016 individuals grouped into 3 orders (Tubificida, Haplotaxida and Lumbriculida), 5 families (Naididae, Tubificidae, Haplotaxidae, Glossoscolecidae and Lumbriculidae) and 5 species were collected and identified. Alma nilotica, positively correlated with dissolved oxygen (P = 0.033; n = 72), was the most abundant species (464 individuals), followed by Tubifex tubifex (216 individuals), positively correlated with salinity (P = 0.029; n = 72), pH (P = 0.037; n = 72) and temperature (P = 0.044; n = 72) Limnodrilus hoffmeisteri and Rhynchemis sp. showed no particular affinity with the abiotic component considered in this study. The Shannon-Weaver's (H') and Pielou's evenness (J) indices coupled with the species richness of all surveyed stations (S1 to S12) showed a greater diversity of taxa only at station S12, located in the lower estuary, 1 km from the mouth; during the dry season. This study shows that the spatial dynamics of oligochaetes in the Nyong estuary are strongly influenced by abiotic parameters and seasonal cycles.
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- 2024
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13. Antiviral activity of intracellular nanobodies targeting the influenza virus RNA-polymerase core.
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Mélissa Bessonne, Jessica Morel, Quentin Nevers, Bruno Da Costa, Allison Ballandras-Colas, Florian Chenavier, Magali Grange, Alain Roussel, Thibaut Crépin, and Bernard Delmas
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Immunologic diseases. Allergy ,RC581-607 ,Biology (General) ,QH301-705.5 - Abstract
Influenza viruses transcribe and replicate their genome in the nucleus of the infected cells, two functions that are supported by the viral RNA-dependent RNA-polymerase (FluPol). FluPol displays structural flexibility related to distinct functional states, from an inactive form to conformations competent for replication and transcription. FluPol machinery is constituted by a structurally-invariant core comprising the PB1 subunit stabilized with PA and PB2 domains, whereas the PA endonuclease and PB2 C-domains can pack in different configurations around the core. To get insights into the functioning of FluPol, we selected single-domain nanobodies (VHHs) specific of the influenza A FluPol core. When expressed intracellularly, some of them exhibited inhibitory activity on type A FluPol, but not on the type B one. The most potent VHH (VHH16) binds PA and the PA-PB1 dimer with an affinity below the nanomolar range. Ectopic intracellular expression of VHH16 in virus permissive cells blocks multiplication of different influenza A subtypes, even when induced at late times post-infection. VHH16 was found to interfere with the transport of the PA-PB1 dimer to the nucleus, without affecting its handling by the importin β RanBP5 and subsequent steps in FluPol assembly. Using FluPol mutants selected after passaging in VHH16-expressing cells, we identified the VHH16 binding site at the interface formed by PA residues with the N-terminus of PB1, overlapping or close to binding sites of two host proteins, ANP32A and RNA-polymerase II RPB1 subunit which are critical for virus replication and transcription, respectively. These data suggest that the VHH16 neutralization is likely due to several activities, altering the import of the PA-PB1 dimer into the nucleus as well as inhibiting specifically virus transcription and replication. Thus, the VHH16 binding site represents a new Achilles' heel for FluPol and as such, a potential target for antiviral development.
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- 2024
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14. Earth stewardship: Shaping a sustainable future through interacting policy and norm shifts
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Chapin, F Stuart, Weber, Elke U, Bennett, Elena M, Biggs, Reinette, van den Bergh, Jeroen, Adger, W Neil, Crépin, Anne-Sophie, Polasky, Stephen, Folke, Carl, Scheffer, Marten, Segerson, Kathleen, Anderies, John M, Barrett, Scott, Cardenas, Juan-Camilo, Carpenter, Stephen R, Fischer, Joern, Kautsky, Nils, Levin, Simon A, Shogren, Jason F, Walker, Brian, Wilen, James, and de Zeeuw, Aart
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Political Science ,Human Society ,Humans ,Policy ,Anthropocene ,Earth stewardship ,Institutions ,Market economy ,Social norms ,Transformation ,Ecology - Abstract
Transformation toward a sustainable future requires an earth stewardship approach to shift society from its current goal of increasing material wealth to a vision of sustaining built, natural, human, and social capital-equitably distributed across society, within and among nations. Widespread concern about earth's current trajectory and support for actions that would foster more sustainable pathways suggests potential social tipping points in public demand for an earth stewardship vision. Here, we draw on empirical studies and theory to show that movement toward a stewardship vision can be facilitated by changes in either policy incentives or social norms. Our novel contribution is to point out that both norms and incentives must change and can do so interactively. This can be facilitated through leverage points and complementarities across policy areas, based on values, system design, and agency. Potential catalysts include novel democratic institutions and engagement of non-governmental actors, such as businesses, civic leaders, and social movements as agents for redistribution of power. Because no single intervention will transform the world, a key challenge is to align actions to be synergistic, persistent, and scalable.
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- 2022
15. Sensitivity of Legionella pneumophila to phthalates and their substitutes
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Alexandre Crépin, Audrey Thiroux, Aurélien Alafaci, Amine M. Boukerb, Izelenn Dufour, Eirini Chrysanthou, Joanne Bertaux, Ali Tahrioui, Alexis Bazire, Sophie Rodrigues, Laure Taupin, Marc Feuilloley, Alain Dufour, Jocelyne Caillon, Olivier Lesouhaitier, Sylvie Chevalier, Jean-Marc Berjeaud, and Julien Verdon
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Medicine ,Science - Abstract
Abstract Phthalates constitute a family of anthropogenic chemicals developed to be used in the manufacture of plastics, solvents, and personal care products. Their dispersion and accumulation in many environments can occur at all stages of their use (from synthesis to recycling). However, many phthalates together with other accumulated engineered chemicals have been shown to interfere with hormone activities. These compounds are also in close contact with microorganisms that are free-living, in biofilms or in microbiota, within multicellular organisms. Herein, the activity of several phthalates and their substitutes were investigated on the opportunistic pathogen Legionella pneumophila, an aquatic microbe that can infect humans. Beside showing the toxicity of some phthalates, data suggested that Acetyl tributyl citrate (ATBC) and DBP (Di-n-butyl phthalate) at environmental doses (i.e. 10–6 M and 10–8 M) can modulate Legionella behavior in terms of motility, biofilm formation and response to antibiotics. A dose of 10–6 M mostly induced adverse effects for the bacteria, in contrast to a dose of 10–8 M. No perturbation of virulence towards Acanthamoeba castellanii was recorded. These behavioral alterations suggest that L. pneumophila is able to sense ATBC and DBP, in a cross-talk that either mimics the response to a native ligand, or dysregulates its physiology.
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- 2023
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16. Critical Resolved Shear Stress and Work Hardening Determination in HCP Metals: Application to Zr Single Crystals
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Jean-Sébastien Lecomte, Jérôme Crépin, and Pierre Barberis
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HCP metals ,work hardening ,in situ tensile test ,CRSS ,zirconium ,Mining engineering. Metallurgy ,TN1-997 - Abstract
Obtaining precise parameters of deformation modes remains a significant challenge in materials science research. Critical resolved shear stresses (CRSS) and work hardening, particularly in hexagonal metals, are crucial parameters for constitutive laws in crystal plasticity. This paper presents a novel approach to determine CRSS and specific hardening matrix coefficients for commercially pure zirconium (α-Zr) at room temperature. In situ methods are employed to measure displacement fields using grids applied to the sample surface, while a comprehensive characterization of the activated deformation systems is performed via SEM and TEM. The CRSS for prismatic ⟨a⟩, pyramidal ⟨a⟩, and 101¯2 and 112¯1 twinning systems, as well as the self-hardening for prismatic slip and several work-hardening coefficients (for prismatic/prismatic and prismatic/pyramidal interactions), are reported in Zr single crystals. Finally, the results are compared with findings from the literature and atomistic simulations.
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- 2024
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17. Thermodynamics of Non-linear magnetic-charged AdS black hole surrounded by quintessence, in the background of perfect fluid dark matter
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Ndongmo, Ragil Brand, Mahamat, Saleh, Bouetou, Thomas Bouetou, Tabi, Conrad Bertrand, and Kofane, Timoleon Crepin
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General Relativity and Quantum Cosmology - Abstract
In this paper, we study the thermodynamic features of a non-linear magnetic-charged AdS black hole surrounded by quintessence, in the background of perfect fluid dark matter(PFDM). After having constructed the corresponding metric, we analyse the structure of the horizon. We find that the existence of inner or outer horizon are constrained by the presence of dark matter. Afterwards, we put out the mass and the temperature of the black hole, in order to get its entropy. Subsequently, we find the expression of the pressure which leads us to get the table of critical values and the isothermal diagram. Especially, we find that the critical values of the temperature and the pressure increase as the dark matter parameter increases. Also, analysing the isothermal diagram, we observe a van der Waals-like behaviour remarked by the presence of a first-order phase transition when we cross the critical temperature. Additionally, we compute and plot the heat capacity and the Hessian matrix of the black hole mass. For the heat capacity, we find that a second-order phase transition occurs, leading the black hole to move from stable phase to unstable one. Furthermore, it comes out that this phase transition point is shifted towards higher values of the horizon radius, as we decrease the dark matter density and increase the quintessence density., Comment: 12 pages, 8 figures
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- 2021
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18. Feasibility study of the Nox-T3 device to detect swallowing and respiration pattern in neurologically impaired patients in the acute phase
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Theytaz, Fanny, Vuistiner, Aline, Schweizer, Valérie, Crépin, Adélie, Sandu, Kishore, Chaouch, Aziz, Piquilloud, Lise, Lecciso, Gianpaolo, Coombes, Kay, and Diserens, Karin
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- 2023
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19. Governance in the Face of Extreme Events: Lessons from Evolutionary Processes for Structuring Interventions, and the Need to Go Beyond
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Levin, Simon A, Anderies, John M, Adger, Neil, Barrett, Scott, Bennett, Elena M, Cardenas, Juan Camilo, Carpenter, Stephen R, Crépin, Anne-Sophie, Ehrlich, Paul, Fischer, Joern, Folke, Carl, Kautsky, Nils, Kling, Catherine, Nyborg, Karine, Polasky, Stephen, Scheffer, Marten, Segerson, Kathleen, Shogren, Jason, van den Bergh, Jeroen, Walker, Brian, Weber, Elke U, and Wilen, James
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Climate Action ,Sustainable Cities and Communities ,Resilience ,Robustness ,Extreme events ,Governance ,Prevention ,Mitigation ,Adaptation ,Environmental Sciences ,Biological Sciences ,Ecology - Abstract
The increasing frequency of extreme events, exogenous and endogenous, poses challenges for our societies. The current pandemic is a case in point; but "once-in-a-century" weather events are also becoming more common, leading to erosion, wildfire and even volcanic events that change ecosystems and disturbance regimes, threaten the sustainability of our life-support systems, and challenge the robustness and resilience of societies. Dealing with extremes will require new approaches and large-scale collective action. Preemptive measures can increase general resilience, a first line of protection, while more specific reactive responses are developed. Preemptive measures also can minimize the negative effects of events that cannot be avoided. In this paper, we first explore approaches to prevention, mitigation and adaptation, drawing inspiration from how evolutionary challenges have made biological systems robust and resilient, and from the general theory of complex adaptive systems. We argue further that proactive steps that go beyond will be necessary to reduce unacceptable consequences.
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- 2022
20. Response diversity as a sustainability strategy
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Walker, Brian, Crépin, Anne-Sophie, Nyström, Magnus, Anderies, John M., Andersson, Erik, Elmqvist, Thomas, Queiroz, Cibele, Barrett, Scott, Bennett, Elena, Cardenas, Juan Camilo, Carpenter, Stephen R., Chapin, III, F. Stuart, de Zeeuw, Aart, Fischer, Joern, Folke, Carl, Levin, Simon, Nyborg, Karine, Polasky, Stephen, Segerson, Kathleen, Seto, Karen C., Scheffer, Marten, Shogren, Jason F., Tavoni, Alessandro, van den Bergh, Jeroen, Weber, Elke U., and Vincent, Jeffrey R.
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- 2023
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21. Modeling and control of 5-DoF boom crane
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Ambrosino, Michele, Berneman, Marc, Carbone, Gianluca, Crépin, Rémi, Dawans, Arnaud, and Garone, Emanuele
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Electrical Engineering and Systems Science - Systems and Control ,Computer Science - Robotics - Abstract
Automation of cranes can have a direct impact on the productivity of construction projects. In this paper, we focus on the control of one of the most used cranes, the boom crane. Tower cranes and overhead cranes have been widely studied in the literature, whereas the control of boom cranes has been investigated only by a few works. Typically, these works make use of simple models making use of a large number of simplifying assumptions (e.g. fixed length cable, assuming certain dynamics are uncoupled, etc.) A first result of this paper is to present a fairly complete nonlinear dynamic model of a boom crane taking into account all coupling dynamics and where the only simplifying assumption is that the cable is considered as rigid. The boom crane involves pitching and rotational movements, which generate complicated centrifugal forces, and consequently, equations of motion highly nonlinear. On the basis of this model, a control law has been developed able to perform position control of the crane while actively damping the oscillations of the load. The effectiveness of the approach has been tested in simulation with realistic physical parameters and tested in the presence of wind disturbances., Comment: the paper was published in 37th International Symposium on Automation and Robotics in Construction (ISARC 2020)
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- 2021
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22. Author Correction: Genome sequences of 36,000- to 37,000-year-old modern humans at Buran-Kaya III in Crimea
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Bennett, E. Andrew, Parasayan, Oğuzhan, Prat, Sandrine, Péan, Stéphane, Crépin, Laurent, Yanevich, Alexandr, Grange, Thierry, and Geigl, Eva-Maria
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- 2024
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23. Emergence of social-psychological barriers to social-ecological resilience: from causes to solutions
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Jean-Denis Mathias, John M Anderies, Anne-Sophie Crépin, Michael Dambrun, Therese Lindahl, and Jon Norberg
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desilience ,resilience ,social-psychological barriers ,sustainability ,Biology (General) ,QH301-705.5 ,Ecology ,QH540-549.5 - Abstract
This study explores social-psychological barriers that may affect resilience in the context of sustainability. These barriers can be understood as unobserved processes that reduce the capacity of a social-ecological system to recover after a perturbation or transformation. Analyzing social-psychological processes enables us to distinguish passive and active processes, at the individual and collective levels. Our work suggests that interacting social and psychological processes should be considered as dynamically evolving determinants of resilience, especially when perturbations can change the psychology of individuals, and thus the underlying dynamics of social-ecological systems. Hence, considering social-psychological barriers and the conditions under which they emerge may provide decision makers with useful insights for coping with ineluctable uncertainties that reduce systems’ transformative capacity and thus their general resilience.
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- 2024
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24. WTO must ban harmful fisheries subsidies
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Sumaila, U Rashid, Skerritt, Daniel J, Schuhbauer, Anna, Villasante, Sebastian, Cisneros-Montemayor, Andrés M, Sinan, Hussain, Burnside, Duncan, Abdallah, Patrízia Raggi, Abe, Keita, Addo, Kwasi A, Adelsheim, Julia, Adewumi, Ibukun J, Adeyemo, Olanike K, Adger, Neil, Adotey, Joshua, Advani, Sahir, Afrin, Zahidah, Aheto, Denis, Akintola, Shehu L, Akpalu, Wisdom, Alam, Lubna, Alava, Juan José, Allison, Edward H, Amon, Diva J, Anderies, John M, Anderson, Christopher M, Andrews, Evan, Angelini, Ronaldo, Anna, Zuzy, Antweiler, Werner, Arizi, Evans K, Armitage, Derek, Arthur, Robert I, Asare, Noble, Asche, Frank, Asiedu, Berchie, Asuquo, Francis, Badmus, Lanre, Bailey, Megan, Ban, Natalie, Barbier, Edward B, Barley, Shanta, Barnes, Colin, Barrett, Scott, Basurto, Xavier, Belhabib, Dyhia, Bennett, Elena, Bennett, Nathan J, Benzaken, Dominique, Blasiak, Robert, Bohorquez, John J, Bordehore, Cesar, Bornarel, Virginie, Boyd, David R, Breitburg, Denise, Brooks, Cassandra, Brotz, Lucas, Campbell, Donovan, Cannon, Sara, Cao, Ling, Cardenas Campo, Juan C, Carpenter, Steve, Carpenter, Griffin, Carson, Richard T, Carvalho, Adriana R, Castrejón, Mauricio, Caveen, Alex J, Chabi, M Nicole, Chan, Kai MA, Chapin, F Stuart, Charles, Tony, Cheung, William, Christensen, Villy, Chuku, Ernest O, Church, Trevor, Clark, Colin, Clarke, Tayler M, Cojocaru, Andreea L, Copeland, Brian, Crawford, Brian, Crépin, Anne-Sophie, Crowder, Larry B, Cury, Philippe, Cutting, Allison N, Daily, Gretchen C, Da-Rocha, Jose Maria, Das, Abhipsita, de la Puente, Santiago, de Zeeuw, Aart, Deikumah, Savior KS, Deith, Mairin, Dewitte, Boris, Doubleday, Nancy, Duarte, Carlos M, Dulvy, Nicholas K, Eddy, Tyler, Efford, Meaghan, Ehrlich, Paul R, Elsler, Laura G, and Fakoya, Kafayat A
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General Science & Technology - Published
- 2021
25. Governance in the Face of Extreme Events: Lessons from Evolutionary Processes for Structuring Interventions, and the Need to Go Beyond.
- Author
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Levin, Simon A, Anderies, John M, Adger, Neil, Barrett, Scott, Bennett, Elena M, Cardenas, Juan Camilo, Carpenter, Stephen R, Crépin, Anne-Sophie, Ehrlich, Paul, Fischer, Joern, Folke, Carl, Kautsky, Nils, Kling, Catherine, Nyborg, Karine, Polasky, Stephen, Scheffer, Marten, Segerson, Kathleen, Shogren, Jason, van den Bergh, Jeroen, Walker, Brian, Weber, Elke U, and Wilen, James
- Subjects
Adaptation ,Extreme events ,Governance ,Mitigation ,Prevention ,Resilience ,Robustness ,Ecology ,Environmental Sciences ,Biological Sciences - Abstract
The increasing frequency of extreme events, exogenous and endogenous, poses challenges for our societies. The current pandemic is a case in point; but "once-in-a-century" weather events are also becoming more common, leading to erosion, wildfire and even volcanic events that change ecosystems and disturbance regimes, threaten the sustainability of our life-support systems, and challenge the robustness and resilience of societies. Dealing with extremes will require new approaches and large-scale collective action. Preemptive measures can increase general resilience, a first line of protection, while more specific reactive responses are developed. Preemptive measures also can minimize the negative effects of events that cannot be avoided. In this paper, we first explore approaches to prevention, mitigation and adaptation, drawing inspiration from how evolutionary challenges have made biological systems robust and resilient, and from the general theory of complex adaptive systems. We argue further that proactive steps that go beyond will be necessary to reduce unacceptable consequences.
- Published
- 2021
26. Staphylococcus aureus nasal colonization level and intracellular reservoir: a prospective cohort study
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Rigaill, Josselin, Gavid, Marie, Fayolle, Martin, Morgene, Mohamed Fedy, Lelonge, Yann, Grattard, Florence, Pozzetto, Bruno, Crépin, Adeline, Prades, Jean-Michel, Laurent, Frédéric, Botelho-Nevers, Elisabeth, Berthelot, Philippe, and Verhoeven, Paul O.
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- 2023
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27. Nonlinear dynamics of inositol 1,4,5-trisphosphate-induced Ca2+ patterns in two-dimensional cell networks with paracrine signaling interaction
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Tiayo, Thierry Kenne, Etémé, Armand Sylvin, Tabi, Conrad Bertrand, Fouda, Henri Paul Ekobena, and Kofané, Timoléon Crépin
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- 2023
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28. Palaeogenomics of Upper Palaeolithic to Neolithic European hunter-gatherers
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Posth, Cosimo, Yu, He, Ghalichi, Ayshin, Rougier, Hélène, Crevecoeur, Isabelle, Huang, Yilei, Ringbauer, Harald, Rohrlach, Adam B., Nägele, Kathrin, Villalba-Mouco, Vanessa, Radzeviciute, Rita, Ferraz, Tiago, Stoessel, Alexander, Tukhbatova, Rezeda, Drucker, Dorothée G., Lari, Martina, Modi, Alessandra, Vai, Stefania, Saupe, Tina, Scheib, Christiana L., Catalano, Giulio, Pagani, Luca, Talamo, Sahra, Fewlass, Helen, Klaric, Laurent, Morala, André, Rué, Mathieu, Madelaine, Stéphane, Crépin, Laurent, Caverne, Jean-Baptiste, Bocaege, Emmy, Ricci, Stefano, Boschin, Francesco, Bayle, Priscilla, Maureille, Bruno, Le Brun-Ricalens, Foni, Bordes, Jean-Guillaume, Oxilia, Gregorio, Bortolini, Eugenio, Bignon-Lau, Olivier, Debout, Grégory, Orliac, Michel, Zazzo, Antoine, Sparacello, Vitale, Starnini, Elisabetta, Sineo, Luca, van der Plicht, Johannes, Pecqueur, Laure, Merceron, Gildas, Garcia, Géraldine, Leuvrey, Jean-Michel, Garcia, Coralie Bay, Gómez-Olivencia, Asier, Połtowicz-Bobak, Marta, Bobak, Dariusz, Le Luyer, Mona, Storm, Paul, Hoffmann, Claudia, Kabaciński, Jacek, Filimonova, Tatiana, Shnaider, Svetlana, Berezina, Natalia, González-Rabanal, Borja, González Morales, Manuel R., Marín-Arroyo, Ana B., López, Belén, Alonso-Llamazares, Carmen, Ronchitelli, Annamaria, Polet, Caroline, Jadin, Ivan, Cauwe, Nicolas, Soler, Joaquim, Coromina, Neus, Rufí, Isaac, Cottiaux, Richard, Clark, Geoffrey, Straus, Lawrence G., Julien, Marie-Anne, Renhart, Silvia, Talaa, Dorothea, Benazzi, Stefano, Romandini, Matteo, Amkreutz, Luc, Bocherens, Hervé, Wißing, Christoph, Villotte, Sébastien, de Pablo, Javier Fernández-López, Gómez-Puche, Magdalena, Esquembre-Bebia, Marco Aurelio, Bodu, Pierre, Smits, Liesbeth, Souffi, Bénédicte, Jankauskas, Rimantas, Kozakaitė, Justina, Cupillard, Christophe, Benthien, Hartmut, Wehrberger, Kurt, Schmitz, Ralf W., Feine, Susanne C., Schüler, Tim, Thevenet, Corinne, Grigorescu, Dan, Lüth, Friedrich, Kotula, Andreas, Piezonka, Henny, Schopper, Franz, Svoboda, Jiří, Sázelová, Sandra, Chizhevsky, Andrey, Khokhlov, Aleksandr, Conard, Nicholas J., Valentin, Frédérique, Harvati, Katerina, Semal, Patrick, Jungklaus, Bettina, Suvorov, Alexander, Schulting, Rick, Moiseyev, Vyacheslav, Mannermaa, Kristiina, Buzhilova, Alexandra, Terberger, Thomas, Caramelli, David, Altena, Eveline, Haak, Wolfgang, and Krause, Johannes
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- 2023
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29. Sanctioned Quotas Versus Information Provisioning for Community Wildlife Conservation in Zimbabwe: A Framed Field Experiment Approach
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Ntuli, Herbert, Crépin, Anne-Sophie, Schill, Caroline, and Muchapondwa, Edwin
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- 2023
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30. Spreading Environmental Economics Worldwide
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Sterner, Thomas, Barbier, Edward B., and Crépin, Anne-Sophie
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- 2023
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31. Phenolic Content, Antioxidant Potential, and Antimicrobial Activity of Uvaria chamae (Annonaceae), a Food Plant from Burkina Faso
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Kayaba Kaboré, Crépin Ibingou Dibala, Hemayoro Sama, Mamounata Diao, Marius K. Somda, and Mamoudou H. Dicko
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Biochemistry ,QD415-436 - Abstract
The study aimed to evaluate phenolic content and antioxidant and antibacterial potentials of the fractions of the hydroethanolic extract of Uvaria chamae leaves, a food plant from Burkina Faso. Thus, the hexane, dichloromethane, ethyl acetate, and butanol fractions of the hydroalcoholic extract after drying were used to determine phenolic compound content, antioxidant activity, and antimicrobial potential on strains of pathogenic bacteria responsible for food contamination. Phytochemical analyses were performed according to standardized methods, while antioxidant activity was evaluated by DPPH and FRAP methods. The antibacterial activity of the fractions was determined by diffusion and microdilution methods on the agar medium with gentamicin as a reference antibiotic. All the six strains, namely, Salmonella typhi ATCC 19430, Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 9027, Bacillus cereus ATCC 13061, and Listeria monocytogenes ATCC 7644, were sensitive to the fractions tested. Minimum inhibitory concentrations ranged from 37 µg·mL−1 to 1.67 mg·mL−1, respectively, gentamicin and butanolic fractions, while minimum bactericidal concentrations of the fractions ranged from 0.037 to 2.500 mg·mL−1 depending on the bacterial strain. Antioxidant activity varied significantly between fractions. For DPPH free radical scavenging activity, the butanol fraction was the most active, with an IC50 of 280 μg/mL, while the lowest activity (705 μg/mL) was recorded by the hexane fraction. Those of trolox and ascorbic acid used as standards were 80 and 100 μg/mL, respectively. Ferric reducing power (FRAP) ranged from 0.34 to 0.40 mmol EAA/g extract for the hexanic and ethyl acetate fractions, respectively. Phenolic compound contents also varied significantly between fractions. Butanoic and ethyl acetate presented the best contents of total phenolics and flavonoids, respectively. Significant and positive correlations were also recorded between phenolics and antioxidant activities. The antibacterial and antioxidant activities of the active fractions would be related to their richness in bioactive compounds, including phenolic, which are powerful natural antioxidants. U. chamae leaf extracts could therefore be used as dietary supplements to boost the immune system and prevent bacterial infections.
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- 2024
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32. Positron production using a 9 MeV electron linac for the GBAR experiment
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Charlton, M., Choi, J. J., Chung, M., Clade, P., Comini, P., Crepin, P-P., Crivelli, P., Dalkarov, O., Debu, P., Dodd, L., Douillet, A., Guellati-Khelifa, S., Hervieux, P-A., Hilico, L., Husson, A., Indelicato, P., Janka, G., Jonsell, S., Karr, J-P., Kim, B. H., Kim, E-S., Kim, S. K., Ko, Y., Kosinski, T., Kuroda, N., Latacz, B., Lee, H., Lee, J., Leite, A. M. M., Leveque, K., Lim, E., Liszkay, L., Lotrus, P., Louvradoux, T., Lunney, D., Manfredi, G., Mansoulie, B., Matusiak, M., Mornacchi, G., Nesvizhevsky, V. V., Nez, F., Niang, S., Nishi, R., Nourbaksh, S., Park, K. H., Paul, N., Perez, P., Procureur, S., Radics, B., Regenfus, C., Rey, J-M., Reymond, J-M., Reynaud, S., Rousse, J-Y., Rousselle, O., Rubbia, A., Rzadkiewicz, J., Sacquin, Y., Schmidt-Kaler, F., Staszczak, M., Tuchming, B., Vallage, B., Voronin, A., Welker, A., van der Werf, D. P., Wolf, S., Won, D., Wronka, S., Yamazaki, Y., and Yoo, K-H.
- Subjects
Physics - Instrumentation and Detectors - Abstract
For the GBAR (Gravitational Behaviour of Antihydrogen at Rest) experiment at CERN's Antiproton Decelerator (AD) facility we have constructed a source of slow positrons, which uses a low-energy electron linear accelerator (linac). The driver linac produces electrons of 9 MeV kinetic energy that create positrons from bremsstrahlung-induced pair production. Staying below 10 MeV ensures no persistent radioactive activation in the target zone and that the radiation level outside the biological shield is safe for public access. An annealed tungsten-mesh assembly placed directly behind the target acts as a positron moderator. The system produces $5\times10^7$ slow positrons per second, a performance demonstrating that a low-energy electron linac is a superior choice over positron-emitting radioactive sources for high positron flux., Comment: published in NIM A. 33 pages 9 figures
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- 2020
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33. Feasibility study of the Nox-T3 device to detect swallowing and respiration pattern in neurologically impaired patients in the acute phase
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Fanny Theytaz, Aline Vuistiner, Valérie Schweizer, Adélie Crépin, Kishore Sandu, Aziz Chaouch, Lise Piquilloud, Gianpaolo Lecciso, Kay Coombes, and Karin Diserens
- Subjects
Medicine ,Science - Abstract
Abstract Dysphagia is a frequent complication in neurologically impaired patients, which can lead to aspiration pneumonia and thus prolonged hospitalization or even death. It is essential therefore, to detect and assess dysphagia early for best patient care. Fiberoptic endoscopic and Videofluoroscopy evaluation of swallowing are the gold standard exams in swallowing studies but neither are perfectly suitable for patients with disorders of consciousness (DOC). In this study, we aimed to find the sensitivity and specificity of the Nox-T3 sleep monitor for detection of swallowing. A combination of submental and peri-laryngeal surface electromyography, nasal cannulas and respiratory inductance plethysmography belts connected to Nox-T 3 allows recording swallowing events and their coordination with breathing, providing time-coordinated patterns of muscular and respiratory activity. We compared Nox-T3 swallowing capture to manual swallowing detection on fourteen DOC patients. The Nox-T3 method identified swallow events with a sensitivity of 95% and a specificity of 99%. In addition, Nox-T3 has qualitative contributions, such as visualization of the swallowing apnea in the respiratory cycle which provide additional information on the swallowing act that is useful to clinicians in the management and rehabilitation of the patient. These results suggest that Nox-T3 could be used for swallowing detection in DOC patients and support its continued clinical use for swallowing disorder investigation.
- Published
- 2023
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34. Optimal phase control in a Remoissenet–Peyrard substrate potential: numerical and analogical investigations
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Kengne, Romanic, Motchongom Tingue, Marceline, Kammogne Souop Tewa, Alain, Djuidjé Kenmoé, Germaine, and Kofane, Timoléon Crépin
- Published
- 2023
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35. Malaria Vaccine Introduction in Cameroon: Early Results 30 Days into Rollout
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Shalom Tchokfe Ndoula, Frank Mboussou, Andreas Ateke Njoh, Raoul Nembot, Simon Franky Baonga, Arnaud Njinkeu, Joseph Biey, Mohamed II Kaba, Adidja Amani, Bridget Farham, Jean-Christian Kouontchou Mimbe, Christian Armel Kouakam, Konstantin Volkmann, Crépin Hilaire Dadjo, Phanuel Habimana, and Benido Impouma
- Subjects
malaria vaccine ,Cameroon ,new vaccine introduction ,Africa ,Medicine - Abstract
Cameroon introduced the malaria vaccine in its routine immunization program on 22 January 2024 in the 42 districts out of 200 that are among the most at risk of malaria. A cross-sectional analysis of the data on key vaccine events in the introduction roadmap and the vaccine uptake during the first 30 days was conducted. In addition to available gray literature related to the introduction of the malaria vaccine, data on the malaria vaccine uptake by vaccination session, collected through a digital platform, were analyzed. A total of 1893 reports were received from 22 January 2024 to 21 February 2024 from 766 health facilities (84% of overall completeness). Two regions out of ten recorded less than 80% completeness. As of 21 February 2024, 13,811 children had received the first dose of the malaria vaccine, including 7124 girls (51.6%) and 6687 boys (48.4%). In total, 36% of the children were vaccinated through outreach sessions, while 61.5% were vaccinated through sessions in fixed posts. The overall monthly immunization coverage with the first dose was 37%. Early results have shown positive attitudes towards and acceptance of malaria vaccines. Suboptimal completeness of data reporting and a low coverage highlight persistent gaps and challenges in the vaccine rollout.
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- 2024
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36. Structural Impact of the Interaction of the Influenza A Virus Nucleoprotein with Genomic RNA Segments
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Erwan Quignon, Damien Ferhadian, Antoine Hache, Valérie Vivet-Boudou, Catherine Isel, Anne Printz-Schweigert, Amélie Donchet, Thibaut Crépin, and Roland Marquet
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influenza A virus ,NP ,nucleoprotein ,vRNA ,RNA structure ,RNA chaperon ,Microbiology ,QR1-502 - Abstract
Influenza A viruses (IAVs) possess a segmented genome consisting of eight viral RNAs (vRNAs) associated with multiple copies of viral nucleoprotein (NP) and a viral polymerase complex. Despite the crucial role of RNA structure in IAV replication, the impact of NP binding on vRNA structure is not well understood. In this study, we employed SHAPE chemical probing to compare the structure of NS and M vRNAs of WSN IAV in various states: before the addition of NP, in complex with NP, and after the removal of NP. Comparison of the RNA structures before the addition of NP and after its removal reveals that NP, while introducing limited changes, remodels local structures in both vRNAs and long-range interactions in the NS vRNA, suggesting a potentially biologically relevant RNA chaperone activity. In contrast, NP significantly alters the structure of vRNAs in vRNA/NP complexes, though incorporating experimental data into RNA secondary structure prediction proved challenging. Finally, our results suggest that NP not only binds single-stranded RNA but also helices with interruptions, such as bulges or small internal loops, with a preference for G-poor and C/U-rich regions.
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- 2024
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37. Effect of endocrine disruptors on bacterial virulence
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Audrey Thiroux, Jean-Marc Berjeaud, Romain Villéger, and Alexandre Crépin
- Subjects
endocrine disruptors ,virulence ,pathogens ,antibiotic tolerance ,biofilm ,Microbiology ,QR1-502 - Abstract
For several decades, questions have been raised about the effects of endocrine disruptors (ED) on environment and health. In humans, EDs interferes with hormones that are responsible for the maintenance of homeostasis, reproduction and development and therefore can cause developmental, metabolic and reproductive disorders. Because of their ubiquity in the environment, EDs can adversely impact microbial communities and pathogens virulence. At a time when bacterial resistance is inevitably emerging, it is necessary to understand the effects of EDs on the behavior of pathogenic bacteria and to identify the resulting mechanisms. Increasing studies have shown that exposure to environmental EDs can affect bacteria physiology. This review aims to highlight current knowledge of the effect of EDs on the virulence of human bacterial pathogens and discuss the future directions to investigate bacteria/EDs interaction. Given the data presented here, extended studies are required to understand the mechanisms by which EDs could modulate bacterial phenotypes in order to understand the health risks.
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- 2023
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38. Thermodynamic of a rotating and Non-linear magnetic-charged black hole in the quintessence field
- Author
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Ndongmo, Ragil Tsafack, Mahamat, Saleh, Bouetou, Thomas Bouetou, and Kofane, Timoleon Crepin
- Subjects
General Relativity and Quantum Cosmology - Abstract
We purpose an approach for the thermodynamic analysis of rotating and non-linear magnetic-charged black hole with quintessence. Accordingly, we compute various thermodynamics quantities of the black hole, such as mass, temperature, potential provided from the magnetic charge, and the heat capacity. Moreover, we study phase transitions of this black hole, analyzing the plot of its heat capacity. Then, we have shown that the black hole mass would have a phase of decrease, while the temperature increases from negative absolute temperatures. From the behavior of the heat capacity, we point out that the black hole undergoes to a second-order phase transition, which is shifted towards the higher values of entropy as we increase the rotating parameter $a$ or the magnetic parameter $Q$., Comment: 8 pages, 12 figures
- Published
- 2019
39. Revisiting photoisomerization in fluorinated analogues of acetylacetone trapped in cryogenic matrices
- Author
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Gutiérrez-Quintanilla, Alejandro, Chevalier, Michèle, Platakyté, Rasa, Ceponkus, Justinas, and Crépin, Claudine
- Published
- 2023
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40. Social dimensions of fertility behavior and consumption patterns in the Anthropocene
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Barrett, Scott, Dasgupta, Aisha, Dasgupta, Partha, Adger, W Neil, Anderies, John, van den Bergh, Jeroen, Bledsoe, Caroline, Bongaarts, John, Carpenter, Stephen, Chapin, F Stuart, Crépin, Anne-Sophie, Daily, Gretchen, Ehrlich, Paul, Folke, Carl, Kautsky, Nils, Lambin, Eric F, Levin, Simon A, Mäler, Karl-Göran, Naylor, Rosamond, Nyborg, Karine, Polasky, Stephen, Scheffer, Marten, Shogren, Jason, Jørgensen, Peter Søgaard, Walker, Brian, and Wilen, James
- Subjects
Contraception/Reproduction ,Behavioral and Social Science ,Basic Behavioral and Social Science ,Africa South of the Sahara ,Conservation of Natural Resources ,Consumer Behavior ,Developed Countries ,Fertility ,Humans ,Income ,Population Growth ,Reproductive Behavior ,Social Change ,Social Conformity ,Sustainable Development ,Technology ,fertility ,consumption ,socially embedded preferences - Abstract
We consider two aspects of the human enterprise that profoundly affect the global environment: population and consumption. We show that fertility and consumption behavior harbor a class of externalities that have not been much noted in the literature. Both are driven in part by attitudes and preferences that are not egoistic but socially embedded; that is, each household's decisions are influenced by the decisions made by others. In a famous paper, Garrett Hardin [G. Hardin, Science 162, 1243-1248 (1968)] drew attention to overpopulation and concluded that the solution lay in people "abandoning the freedom to breed." That human attitudes and practices are socially embedded suggests that it is possible for people to reduce their fertility rates and consumption demands without experiencing a loss in wellbeing. We focus on fertility in sub-Saharan Africa and consumption in the rich world and argue that bottom-up social mechanisms rather than top-down government interventions are better placed to bring about those ecologically desirable changes.
- Published
- 2020
41. Physico-chemical and high frequency monitoring dataset from mesocosm experiments simulating extreme climate events in lakes
- Author
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Viet Tran-Khac, Philippe Quetin, Laurent Espinat, Laura Crépin, Charlotte Cousin, Pascal Perney, Jean-Christophe Hustache, Geneviève Chiapusio, Isabelle Domaizon, and Serena Rasconi
- Subjects
Climate change ,Aquatic ecosystems functioning ,Turbid storms ,Terrestrial subsidies ,Experimental ecology ,Large peri-alpine lakes ,Computer applications to medicine. Medical informatics ,R858-859.7 ,Science (General) ,Q1-390 - Abstract
We present two datasets composed of high frequency sensors data, vertical in situ profiles and laboratory chemical analysis data, acquired during two different aquatic mesocosm experiments performed at the OLA (“Long-term observation and experimentation for lake ecosystems”) facility at the UMR CARRTEL in Thonon les Bains, on the French shore of Lake Geneva. The DOMLAC experiment lasted 3 weeks (4-21 October 2021) and aimed to simulate predicted climate scenarios (i.e. extreme events such as storms and floods) by reproducing changes in quality and composition of lake subsidies and runoff by increased inputs of terrestrial organic matter. The PARLAC experiment lasted 3 weeks (5-23 September 2022) and aimed to simulate turbid storms by light reduction.The experimental setup consisted of nine inland polyester laminated tanks (2.1 m length, 2.1 m width and 1.1 m depth) with a total volume of approximately 4000 L and filled with water directly supplied from the lake at 4m depth. Both experimental design included three treatments each replicated three times. The DOMLAC experiment involved a control treatment (no treatment applied) and two treatments simulating allochthonous inputs from two different dissolved organic matter (DOM) extract from peat moss Sphagnum sp. (Peat-Moss treatment) and Phragmites australis (Phragmite treatment). The PARLAC experiment involved a control treatment (no treatment applied) and two treatments simulating two different intensity of light reduction. In the Medium treatment transmitted light was reduced to 70% and in the High treatment transmitted light was reduced to 15%.The datasets are composed of: 1. In situ measures from automated data loggers of temperature, conductivity, dissolved oxygen and CO2 acquired every 5 minutes at 0.1, 0.5 and 1 m depth (DOMLAC) and 0.5m (PARLAC) for the entire period of the experiment. 2. In situ profiles (0-1 m) of temperature, conductivity, pH, dissolved oxygen (concentration and saturation) acquired twice a week during the experiment. 3. In situ measures of light spectral UV/VIS/IR irradiance (300-950 nm wavelength range) taken in the air and at 0, 0.5 and 1 m twice a week on the same day of the profiles at point 2. 4. Laboratory chemical analysis of integrated samples taken twice a week on the same day of the in situ profiles at point 2 and 3 of conductivity, pH, total alkalinity, NO3, total and particulate nitrogen (Ntot, Npart), PO4, total and particulate phosphorus (Ptot, Ppart), total and particulate organic carbon (TOC, POC), Ca, K, Mg, Na, Cl, SO4 and SiO2. Only for DOMLAC also analyses of NH4, NO2 and dissolved organic carbon (DOC). 5. Laboratory analysis of pigments (Chla, Chlc, carotenoids, phaeopigments) extracted from samples collected at point 4. 6. Only for DOMLAC, specific absorbance on the range 600-200nm of DOM (i.e.
- Published
- 2023
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42. Thermodynamic Phase Transition and global stability of the Regular Hayward Black hole Surrounded by Quintessence
- Author
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Rodrigue, Kamiko Kouemeni Jean, Saleh, Mahamat, Thomas, Bouetou Bouetou, and Kofane, Timoleon Crepin
- Subjects
General Relativity and Quantum Cosmology - Abstract
In this work, we investigate the thermodynamic and the stability of the regular Hayward black hole surrounded by quintessence. Using the metric of the black hole surrounded by quintessence and the new approach of the holographic principle, we derive the expression of the Unruh Verlinde temperature. Hawking temperature and specific heat are derived using the first law of black holes thermodynamics. Gibbs free energy is also evaluated. The behaviors of these quantities show that, the quantum effects represented by the parameter $\beta$ induces a decreasing of the Hawking temperature of the black hole, and that decrease is accentuated when increasing the magnitude of $\beta$ and the normalization factor $a$ related to the density of quintessence. For the lower entropies, the black hole passes from the unstable phase to the stable one by a first order thermodynamics phase transition. When increasing the entropy, a second phase transition occurs. This new phase transition is a second-order thermodynamics phase transition and brings the black hole to unstable state. It results that, when increasing of magnitude of $\beta$, the phase transition points are shifted to the higher entropies. Moreover, the phenomena of phase transitions are preserved by adding the quintessence. Furthermore, when increasing the normalization factor of quintessence, the first order transition point is shifted to higher entropies, while the second-order thermodynamics phase transition point is shifted to lower entropies., Comment: 14 pages, 8 figures
- Published
- 2018
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43. Functional diversity of the fish fauna in the Nyong estuary (Atlantic Coast, Cameroon), and its correlation with environmental variables
- Author
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Paul Alain Nana, Nectaire Lié Nyamsi Tchatcho, Anselme Crépin Mama, Fils Mamert Onana, Delf Kamogne Nono, Hassan Bassirou, and Arnold Roger Bitja Nyom
- Subjects
Diversity ,Environmental variables ,Ichthyofauna ,Nyong estuary ,Sustainable fishing ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
Archaic fishing, anthropogenic pollution linked to demographic and economic growth stand to be a real threat to the richness and abundance of the aquatic fauna of estuaries in Sub-Saharan Africa. The knowledge of the Nyong estuary ichthyofauna's ecology in Cameroon is particularly essential to establish a management plan and sustainable management of this important ecosystem. The Nyong estuary ichthyofauna was composed of 13 families, 20 genera and 22 species, from February to June 2020. Eleven species had a marine affinity while11 others were from the freshwater dirivation. Mormyridae (14%), Cichlidae (14%) and Clupeidae (14%) were the most represented families. Also, Chrysichthys nyongensis was the most abundant species with a frequency of 30.26%. Despite the low diversity in the study area, the specific diversity index showed that Dikobe was the most diverse station (H' = 2.98 and J = 0.46), contrary to Donenda's station (H' = 2.30 and J = 0.22). In general, significant correlations were noted between physico-chemical parameters and the total abundances of the different fish species (P
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- 2023
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44. Spectral and Aggregation Properties of Phenylthio-Substituted Al-Phthalocyanine Molecules in Nanoporous Silicate Matrices
- Author
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Arabei, S. M., Pavich, T. A., Stanishevsky, I. V., and Crépin, C.
- Published
- 2022
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45. Ultrashort self-similar periodic waves and similaritons in an inhomogeneous optical medium with an external source and modulated coefficients
- Author
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Djoptoussia, Calvin, Tiofack, Camus Gaston Latchio, Alim, Mohamadou, Alidou, and Kofané, Timoléon Crépin
- Published
- 2022
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- View/download PDF
46. Digital Volume Correlation analyses to study deformation and damage mechanisms of teak in torsion
- Author
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Valmalle, Malo, Hounlonon, Montcho Crépin, Smaniotto, Benjamin, Kouchadé, Clément A., and Hild, François
- Subjects
Wood ,Crack ,Digital Volume Correlation (DVC) ,In situ test ,Tomography ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
Wood is a material with anisotropic elastic properties at the macroscale. In the present work, a sample made of Beninise teak was subjected to in situ torsion. Digital Volume Correlation (DVC) analyses were run at the mesoscale to measure displacement fields. The corresponding strain fields were obtained at the same scale in addition to the gray level residuals at the voxel scale. The out-of-plane shear modulus could be calibrated at the macroscale and was in good agreement with earlier results of the coauthors (MCH and CAK). The ultimate shear strength was also assessed at the same scale. Last, damage was detected and quantified at the mesoscale thanks to strain fields and at the microscale via gray level residual fields.
- Published
- 2022
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47. Nonlinear dynamics of damped DNA systems with long-range interactions
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Okaly, J. Brizar, Mvogo, Alain, Woulaché, R. Laure, and Kofané, T. Crépin
- Subjects
Physics - Biological Physics - Abstract
We investigate the nonlinear dynamics of a damped Peyrard-Bishop DNA model taking into account long-range interactions with distance dependence |l|^-s on the elastic coupling constant between different DNA base pairs. Considering both Stokes and long-range hydrodynamical damping forces, we use the discrete difference operator technique and show in the short wavelength modes that the lattice equation can be governed by the complex Ginzburg-Landau equation. We found analytically that the technique leads to the correct expression for the breather soliton parameters. We found that the viscosity makes the amplitude of the breather to damp out. We compare the approximate analytic results with numerical simulations for the value s = 3 (dipole-dipole interactions)., Comment: 14 pages, 17 figures, Commun Nonlinear Sci Numer Simulat (2017)
- Published
- 2017
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48. Nonlinear dynamics of DNA systems with inhomogeneity effects
- Author
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Okaly, Joseph Brizar, Mvogo, Alain, Woulache, Rosalie Laure, and Kofane, Timoleon Crepin
- Subjects
Physics - Biological Physics ,Condensed Matter - Soft Condensed Matter ,Nonlinear Sciences - Pattern Formation and Solitons - Abstract
We investigate the nonlinear dynamics of the Peyrard-Bishop DNA model taking into account site dependent inhomogeneities. By means of the multiple-scale expansion in the semi-discrete approximation, the dynamics is governed by the perturbed nonlinear Schrodinger equation. We carry out a multiple-scale soliton perturbation analysis to find the effects of the variety of nonlinear inhomogeneities on the breatherlike soliton solution. During the crossing of the inhomogeneities, the coherent structure of the soliton is found stable. The global shape of the inhomogeneous molecule is merged with the shape of the homogeneous molecule. However, the velocity, the wavenumber and the angular frequency undergo a time-dependent correction that is proportional to initial width of the soliton and depends on the nature of the inhomogeneities., Comment: 21 pages, 20 figures, paper under review
- Published
- 2017
49. Thermodynamics and Phase transition from regular Bardeen black hole
- Author
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Saleh, Mahamat, Thomas, Bouetou Bouetou, and Crépin, Kofané Timoléon
- Subjects
General Relativity and Quantum Cosmology - Abstract
In this paper, thermodynamics and phase transition are investigated for the regular Bardeen black hole. Considering the metric of the Bardeen spacetime, we derived the Unruh-Verlinde temperature. Using the first law of thermodynamics, we derived the expression of the specific heat and plot its behavior. It results that the magnetic monopole charge $\beta$ reduces the temperature and induces a thermodynamics phase transition in the spacetime. Moreover, when increasing $\beta$, the transition point moves to higher entropy., Comment: 8 pages, 4 figures
- Published
- 2017
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50. Signatures of interaction-induced helical gaps in nanowire quantum point contacts
- Author
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Heedt, S., Ziani, N. Traverso, Crépin, F., Prost, W., Trellenkamp, St., Schubert, J., Grützmacher, D., Trauzettel, B., and Schäpers, Th.
- Subjects
Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
Spin-momentum locking in a semiconductor device with strong spin-orbit coupling (SOC) is a fundamental goal of nanoscale spintronics and an important prerequisite for the formation of Majorana bound states. Such a helical state is predicted in one-dimensional (1D) nanowires subject to strong Rashba SOC and spin-mixing, its hallmark being a characteristic reentrant behaviour in the conductance. Here, we report the first direct experimental observations of the reentrant conductance feature, which reveals the formation of a helical liquid, in the lowest 1D subband of an InAs nanowire. Surprisingly, the feature is very prominent also in the absence of magnetic fields. This behaviour suggests that exchange interaction exhibits substantial impact on transport in our device. We attribute the opening of the pseudogap to spin-flipping two-particle backscattering. The all-electric origin of the ideal helical transport bears momentous implications for topological quantum computing., Comment: submitted to Nature Physics in September 2016
- Published
- 2017
- Full Text
- View/download PDF
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