798 results on '"Ramond, P"'
Search Results
2. Expansion of the neurodevelopmental phenotype of individuals with EEF1A2 variants and genotype-phenotype study
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Paulet, Alix, Bennett-Ness, Cavan, Ageorges, Faustine, Trost, Detlef, Green, Andrew, Goudie, David, Jewell, Rosalyn, Kraatari-Tiri, Minna, PIARD, Juliette, Coubes, Christine, Lam, Wayne, Lynch, Sally Ann, Groeschel, Samuel, Ramond, Francis, Fluss, Joël, Fagerberg, Christina, Brasch Andersen, Charlotte, Varvagiannis, Konstantinos, Kleefstra, Tjitske, Gérard, Bénédicte, Fradin, Mélanie, Vitobello, Antonio, Tenconi, Romano, Denommé-Pichon, Anne-Sophie, Vincent-Devulder, Aline, Haack, Tobias, Marsh, Joseph A, Laulund, Lone Walentin, Grimmel, Mona, Riess, Angelika, de Boer, Elke, Padilla-Lopez, Sergio, Bakhtiari, Somayeh, Ostendorf, Adam, Zweier, Christiane, Smol, Thomas, Willems, Marjolaine, Faivre, Laurence, Scala, Marcello, Striano, Pasquale, Bagnasco, Irene, Koboldt, Daniel, Iascone, Maria, Suerink, Manon, Kruer, Michael C, Levy, Jonathan, Verloes, Alain, Abbott, Catherine M, and Ruaud, Lyse
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- 2024
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3. Symplectic mechanics of relativistic spinning compact bodies II.: Canonical formalism in the Schwarzschild spacetime
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Ramond, Paul and Isoyama, Soichiro
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General Relativity and Quantum Cosmology ,Nonlinear Sciences - Exactly Solvable and Integrable Systems - Abstract
This work constitutes the second part of a series of studies that aim to utilise tools from Hamiltonian mechanics to investigate the motion of an extended body in general relativity. The first part of this work [Refs. [1, 2]] constructed a ten-dimensional, covariant Hamiltonian framework encompassing all the linear-in-spin corrections to the geodesic motion in arbitrary spacetime. This framework was proven to be integrable in the Schwarzschild and Kerr spacetimes, specifically. The present work translates this abstract integrability result into tangible applications for linear-in-spin Hamiltonian dynamics of a compact object in a Schwarzschild spacetime. In particular, a canonical system of coordinates is constructed explicitly, which exploits the spherical symmetry of the Schwarzschild spacetime. These coordinates are based on a relativistic generalization of the classical Andoyer variables of Newtonian rigid body motion. This canonical setup allows us to derive ready-to-use formulae for action-angle coordinates and gauge-invariant Hamiltonian frequencies, which automatically include all linear-in-spin effects. No external parameters or ad hoc choices are necessary, and the framework can be used to find complete solutions by quadrature of generic (bound or unbound), linear-in-spin orbits, including orbital inclination, precession and eccentricity, as well as spin precession. The efficacy of the formalism is demonstrated here in the context of circular orbits with arbitrary spin and orbital precession, with the results validated against known results in the literature., Comment: 69 pages, 3 figures, 2 tables. V2: minor revisions before submission to PRD. added references
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- 2024
4. On the integrability of extended test body dynamics around black holes
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Ramond, Paul
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General Relativity and Quantum Cosmology ,Nonlinear Sciences - Exactly Solvable and Integrable Systems - Abstract
In general relativity, the motion of an extended test body is influenced by its proper rotation, or spin. We present a covariant and physically self-consistent Hamiltonian framework to study this motion, up to quadratic order in the body's spin, including a spin-induced quadrupole, and in an arbitrary background spacetime. The choice of spin supplementary condition and degeneracies associated with local Lorentz invariance are treated rigorously with adapted tools from Hamiltonian mechanics. Applying the formalism to a background space-time described by the Kerr metric, we prove that the motion of any test compact object around a rotating black hole defines an integrable Hamiltonian system to linear order in the body's spin. Moreover, this integrability still holds at quadratic order in spin when the compact object has the deformability expected for an isolated black hole. Our analytical results shed light on longstanding numerical conjectures regarding spin-induced chaos in the motion of asymmetric compact binaries, and provides a powerful framework to improve current gravitational waveform modelling to account for spin-induced extended body effects., Comment: 6 pages
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- 2024
5. Exploring the Truth and Beauty of Theory Landscapes with Machine Learning
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Matchev, Konstantin T., Matcheva, Katia, Ramond, Pierre, and Verner, Sarunas
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High Energy Physics - Phenomenology ,Computer Science - Machine Learning - Abstract
Theoretical physicists describe nature by i) building a theory model and ii) determining the model parameters. The latter step involves the dual aspect of both fitting to the existing experimental data and satisfying abstract criteria like beauty, naturalness, etc. We use the Yukawa quark sector as a toy example to demonstrate how both of those tasks can be accomplished with machine learning techniques. We propose loss functions whose minimization results in true models that are also beautiful as measured by three different criteria - uniformity, sparsity, or symmetry., Comment: 13 pages, 9 figures. arXiv admin note: text overlap with arXiv:2311.00087
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- 2024
6. Compound Heterozygous WARS2 Variants Including a Hypomorphic Allele Cause a Milder Phenotype of Complex Dopa Responsive Dystonia: Case Report and Review of the Literature
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Schneider, Vincent, Dupont, Gwendoline, Madinier, Guillaume, Ramond, Francis, Lesca, Gaetan, Thauvin-Robinet, Christel, and Thomas, Quentin
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- 2024
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7. Seeking Truth and Beauty in Flavor Physics with Machine Learning
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Matchev, Konstantin T., Matcheva, Katia, Ramond, Pierre, and Verner, Sarunas
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High Energy Physics - Phenomenology ,Computer Science - Machine Learning ,Mathematical Physics - Abstract
The discovery process of building new theoretical physics models involves the dual aspect of both fitting to the existing experimental data and satisfying abstract theorists' criteria like beauty, naturalness, etc. We design loss functions for performing both of those tasks with machine learning techniques. We use the Yukawa quark sector as a toy example to demonstrate that the optimization of these loss functions results in true and beautiful models., Comment: 10 pages, 6 figures; Accepted by "AI for Science" NeurIPS 2023 Workshop
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- 2023
8. Cross-cultural adaptation of the Quebecois Patient-Centered Coordination by a Care Team Questionnaire for use in France
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Arthur Piraux, Marie-Eve Poitras, Sandra Lemarchand, Stephanie Sidorkiewicz, and Aline Ramond-Roquin
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Coordination of care ,Patient-centered care ,Teamwork ,Patient reported experience measure ,Primary care ,Health care organization ,Medicine (General) ,R5-920 - Abstract
Abstract Background The prevalence of chronic disease and multimorbidity is increasing and the associated disease and treatment burden is particularly heavy. Coordinated multidisciplinary, patient-centered care is particularly important for people living with chronic disease or multimorbidity. There was no valid tool to measure the quality of coordinated patient-centered care from the patient’s perspective until the Patient-Centered Coordination by a Care Team (PCCCT) questionnaire was recently developed in Canada (Quebec/Ontario). The Quebecois version has been validated but is not directly transferable to France due to linguistic, cultural and health system differences between the two countries. To perform a cross-cultural adaptation of the Quebecois PCCCT questionnaire is therefore necessary to obtain a questionnaire’s new version adapted for use in France, ensuring item and semantic equivalence. Methods The adaptation process consisted of two stages, both of which were supervised by a scientific committee made up of five healthcare professionals. The first stage was a Delphi consensus involving a multidisciplinary healthcare professional panel to evaluate and harmonize the clarity and appropriateness of the questionnaire for patients in the French health system. During the second stage, adult patients with one or more chronic diseases, from various age, sex, socio-occupational categories, assessed the comprehensibility and conformity of the adapted version of the questionnaire resulting from stage 1 and improved it if necessary. This was achieved using cognitive interviews. Results During Stage 1, two rounds were undertaken with 10 professional experts resulting in consensual reformulation of 10 out of the 14 items. These newly formulated items and the 4 remaining items were submitted to patients in Stage 2. Cognitive interviews were undertaken with 14 patients, testing 3 successively adapted versions of the questionnaire, until three consecutive patients did not find any ambiguity or misunderstanding. The final version resulting from the cross-cultural adaptation process aimed at being used in France, has item and semantic equivalence to the original Quebecois version. Conclusions Measurement equivalence will be addressed in a future study. This French version is intended to be a useful resource for the health system reforms aimed at promoting more integrated and patient-centered care pathways.
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- 2024
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9. Efficacy of a pharmacist care protocol to manage uncomplicated female cystitis in community pharmacies: an open-label, multicenter, randomized, controlled, cluster study: the PharmaCyst’ protocol
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Arthur Piraux, Elsa Parot-Schinkel, Jean-François Hamel, Kurt Naber, Anne-Claire Oger, Alain Guilleminot, Aline Ramond-Roquin, and Sébastien Faure
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Urinary tract infections ,Uncomplicated cystitis ,Dispensing under protocol ,Community pharmacist ,Primary care ,Study protocol ,Medicine (General) ,R5-920 - Abstract
Abstract Background Urinary tract infections are common affections, especially for women. Difficult access to a general practitioner to obtain a prescription has led France to offer dispensing under protocol by community pharmacists. The primary objective of this study is to evaluate the effectiveness of a pharmacist care protocol provided to manage women with urinary tract infection symptoms. This objective will be assessed using the Acute Cystitis Symptom Score. Methods PharmaCyst’ is an open-label, multicenter, controlled, cluster-randomized study conducted in the Loire region, France. Women aged between 18 and 65 years presenting to a pharmacy complaining of at least one symptom of an uncomplicated urinary tract infection present over the last 3 days (including burning pain during micturition, dysuria, pollakiuria, urgent urination) will be considered for inclusion. All patients will be contacted on day 3, 10, and month 3. A total of 480 patients need to be recruited for the 24 clusters participating in the research. The quantitative data will be described using means and standard deviations and compared using Student’s t-test. The qualitative data will be described using numbers and percentages and compared using chi2 test (or Fisher’s exact test if necessary). The primary and secondary outcomes analyses will consider the intention-to-treat population. Discussion PharmaCyst’ is the first clinical trial conducted in France only by community pharmacists. Its results could lead to an extension of the protocol. Trial registration The protocol has been approved by the French ethics committee on 2022/12/02 and is registered under the number 49RC22_0240 on ClinicalTrials.gov.
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- 2024
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10. Adaptation of French general practitioners for the management of nursing home patients during COVID-19 in 2020: a multilevel analysis
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Veronique Orcel, Tiphanie Bouchez, Aline Ramond-Roquin, Yann Bourgueil, Vincent Renard, Sylvain Gautier, and Julien Le Breton
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COVID-19 ,Continuity of patient care ,General practice ,Nursing homes ,Primary care ,Patient care management. ,Medicine (General) ,R5-920 - Abstract
Abstract Background To describe French general practioners’ (GPs) adaptation strategies to ensure follow-up care of nursing home patients during the first wave of COVID-19 (May 2020) and to identify factors associated with each strategy. Methods A national cross-sectional study was conducted with online questionnaires in May 2020 among GPs practicing in France (metropolitan and overseas) and usually providing nursing home visits before pandemic. The outcome was defined as the GPs’ adaptation strategies for managing nursing home patients and was categorized into four groups: Maintenance of Nursing Home Visits NHV (reference), Stopping NHV, Numeric adaptation (teleconsultations only), Mixed adaptation (NHV and teleconsultations). The probability of adaptation strategies was analyzed by multilevel logistic models in which the GPs represented level 1 and the counties level 2. We applied three random-intercept multilevel logistic models with the county of GP’s practice as random effect. Results This analysis included 2,146 responses by GPs coming from 98 French counties. Overall, 40.4% of GPs maintained NHV, while other strategies were: Stopping visits (24.1%), Numeric adaptation (15.4%), Mixed adaptation (20.1%). Several individual (age, training GP, perceived status of being at high risk of severe COVID, compliance with temporary delegation of the patient’s management) and territorial factors (excess mortality rate due to COVID-19, GPs’ density, proportion of over-75s, presence of reinforcement measures for nursing home patients) were identified as associated with each strategy. Conclusions This study highlights a rapid adaptation of general practice to keep supporting nursing home patients. Heterogeneity of adaptation strategies could reflect both the lack of national guidelines and the heterogeneity among GPs’ usual practices. Policymakers should take actions at a territorial level (subnational) to strengthen support to nursing home patients considering adaptations to the local context of the pandemic outbreak and perspective of local actors.
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- 2024
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11. Enhanced train-the-trainer program for registered nurses and social workers to apply the founding principles of primary care in their practice: a pre-post study
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Marie-Eve Poitras, Yves Couturier, Emmauelle Doucet, Vanessa T. Vaillancourt, Gilles Gauthier, Marie-Dominique Poirier, Sylvie Massé, Catherine Hudon, Nathalie Delli-Colli, Dominique Gagnon, Emmanuelle Careau, Arnaud Duhoux, Isabelle Gaboury, Djamal Berbiche, Ali Ben Charif, Rachelle Ashcroft, Julia Lukewich, Aline Ramond-Roquin, Priscilla Beaupré, and Anaëlle Morin
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Train-the-trainer ,Primary care ,Nurse ,Social worker ,Patient-oriented research ,Healthcare ,Medicine (General) ,R5-920 - Abstract
Abstract Background A train-the-trainer approach can effectively support the integration of new practice standards for health and social services professionals. This study describes the effects of an enhanced train-the-trainer program to support registered nurses and social workers working in primary care clinics in their understanding of the fundamental principles of primary care. Methods We implemented an enhanced train-the-trainer program for registered nurses and social workers in six primary care clinics. We conducted a pre-post study using quantitative and qualitative data to assess trainers’ and trainees’ intention, commitment, and confidence in applying acquired knowledge. Results We trained 11 trainers and 33 trainees. All the trainers and trainees were satisfied with the program. Trainers were less confident in their abilities as trainers following the training, especially regarding tailored coaching (p = 0.03). Trainees’ commitment to becoming familiar with the functioning of their clinic (p = 0.05) and becoming part of the team increased significantly (p = 0.01); however, their intention to use their knowledge decreased (p = 0.02). Trainers and trainees identified organizational and professional barriers that may explain the observed decrease. Conclusion An enhanced train-the-trainer program positively impacted registered nurses’ and social workers’ assimilation of the fundamental principles of primary care. Further research is needed to understand the long-term effects of train-the-trainer programs on primary care trainees and how these effects translate into patient care.
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- 2024
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12. Cross-cultural adaptation of the Quebecois Patient-Centered Coordination by a Care Team Questionnaire for use in France
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Piraux, Arthur, Poitras, Marie-Eve, Lemarchand, Sandra, Sidorkiewicz, Stephanie, and Ramond-Roquin, Aline
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- 2024
- Full Text
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13. Efficacy of a pharmacist care protocol to manage uncomplicated female cystitis in community pharmacies: an open-label, multicenter, randomized, controlled, cluster study: the PharmaCyst’ protocol
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Piraux, Arthur, Parot-Schinkel, Elsa, Hamel, Jean-François, Naber, Kurt, Oger, Anne-Claire, Guilleminot, Alain, Ramond-Roquin, Aline, and Faure, Sébastien
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- 2024
- Full Text
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14. Adaptation of French general practitioners for the management of nursing home patients during COVID-19 in 2020: a multilevel analysis
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Orcel, Veronique, Bouchez, Tiphanie, Ramond-Roquin, Aline, Bourgueil, Yann, Renard, Vincent, Gautier, Sylvain, and Breton, Julien Le
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- 2024
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15. Enhanced train-the-trainer program for registered nurses and social workers to apply the founding principles of primary care in their practice: a pre-post study
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Poitras, Marie-Eve, Couturier, Yves, Doucet, Emmauelle, T. Vaillancourt, Vanessa, Gauthier, Gilles, Poirier, Marie-Dominique, Massé, Sylvie, Hudon, Catherine, Delli-Colli, Nathalie, Gagnon, Dominique, Careau, Emmanuelle, Duhoux, Arnaud, Gaboury, Isabelle, Berbiche, Djamal, Ben Charif, Ali, Ashcroft, Rachelle, Lukewich, Julia, Ramond-Roquin, Aline, Beaupré, Priscilla, and Morin, Anaëlle
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- 2024
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16. Correction: Expansion of the neurodevelopmental phenotype of individuals with EEF1A2 variants and genotype-phenotype study
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Paulet, Alix, Bennett-Ness, Cavan, Ageorges, Faustine, Trost, Detlef, Green, Andrew, Goudie, David, Jewell, Rosalyn, Kraatari-Tiri, Minna, PIARD, Juliette, Coubes, Christine, Lam, Wayne, Lynch, Sally Ann, Groeschel, Samuel, Ramond, Francis, Fluss, Joël, Fagerberg, Christina, Brasch Andersen, Charlotte, Varvagiannis, Konstantinos, Kleefstra, Tjitske, Gérard, Bénédicte, Fradin, Mélanie, Vitobello, Antonio, Tenconi, Romano, Denommé-Pichon, Anne-Sophie, Vincent-Devulder, Aline, Haack, Tobias, Marsh, Joseph A, Laulund, Lone Walentin, Grimmel, Mona, Riess, Angelika, de Boer, Elke, Padilla-Lopez, Sergio, Bakhtiari, Somayeh, Ostendorf, Adam, Zweier, Christiane, Smol, Thomas, Willems, Marjolaine, Faivre, Laurence, Scala, Marcello, Striano, Pasquale, Bagnasco, Irene, Koboldt, Daniel, Iascone, Maria, Suerink, Manon, Kruer, Michael C, Levy, Jonathan, Verloes, Alain, Abbott, Catherine M, and Ruaud, Lyse
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- 2024
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17. Modelling soil prokaryotic traits across environments with the trait sequence database ampliconTraits and the R package MicEnvMod
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Jonathan Donhauser, Anna Doménech-Pascual, Xingguo Han, Karen Jordaan, Jean-Baptiste Ramond, Aline Frossard, Anna M. Romaní, and Anders Priemé
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Trait sequence database ,DNA sequencing ,Microbial community ,Cross validation ,Weighted ensemble model ,Information technology ,T58.5-58.64 ,Ecology ,QH540-549.5 - Abstract
We present a comprehensive, customizable workflow for inferring prokaryotic phenotypic traits from marker gene sequences and modelling the relationships between these traits and environmental factors, thus overcoming the limited ecological interpretability of marker gene sequencing data. We created the trait sequence database ampliconTraits, constructed by cross-mapping species from a phenotypic trait database to the SILVA sequence database and formatted to enable seamless classification of environmental sequences using the SINAPS algorithm. The R package MicEnvMod enables modelling of trait – environment relationships, combining the strengths of different model types and integrating an approach to evaluate the models' predictive performance in a single framework. Traits could be accurately predicted even for sequences with low sequence identity (80 %) with the reference sequences, indicating that our approach is suitable to classify a wide range of environmental sequences. Validating our approach in a large trans-continental soil dataset, we showed that trait distributions were robust to classification settings such as the bootstrap cutoff for classification and the number of discrete intervals for continuous traits. Using functions from MicEnvMod, we revealed precipitation seasonality and land cover as the most important predictors of genome size. We found Pearson correlation coefficients between observed and predicted values up to 0.70 using repeated split sampling cross validation, corroborating the predictive ability of our models beyond the training data. Predicting genome size across the Iberian Peninsula, we found the largest genomes in the northern part. Potential limitations of our trait inference approach include dependence on the phylogenetic conservation of traits and limited database coverage of environmental prokaryotes. Overall, our approach enables robust inference of ecologically interpretable traits combined with environmental modelling allowing to harness traits as bioindicators of soil ecosystem functioning.
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- 2024
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18. Soil organic matter properties drive microbial enzyme activities and greenhouse gas fluxes along an elevational gradient
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Xingguo Han, Anna Doménech-Pascual, Joan Pere Casas-Ruiz, Jonathan Donhauser, Karen Jordaan, Jean-Baptiste Ramond, Anders Priemé, Anna M. Romaní, and Aline Frossard
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Greenhouse gas fluxes ,Mountainous soils ,Elevational gradient ,SOM quantity and composition ,Microbial enzyme activities and gene functions ,Science - Abstract
Mountain ecosystems, contributing substantially to the global carbon (C) and nitrogen (N) biogeochemical cycles, are heavily impacted by global changes. Although soil respiration and microbial activities have been extensively studied at different elevation, little is known on the relationships between environmental drivers, microbial functions, and greenhouse gas fluxes (GHGs; carbon dioxide [CO2], methane [CH4] and nitrous oxide [N2O]) in soils of different elevation. Here, we measured how in situ GHG fluxes were linked to soil properties, soil organic matter (SOM) quantity and composition (the proportion of humic-like vs. protein-like OM), microbial biomass, enzyme activities and functional gene abundances in natural soils spanning an elevational gradient of ∼2400 m in Switzerland. Soil CO2 fluxes did not significantly vary from low (lowland zone) to higher (montane and subalpine zones) elevation forests, but decreased significantly (P
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- 2024
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19. Exploring the truth and beauty of theory landscapes with machine learning
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Konstantin T. Matchev, Katia Matcheva, Pierre Ramond, and Sarunas Verner
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Physics ,QC1-999 - Abstract
Theoretical physicists describe nature by i) building a theory model and ii) determining the model parameters. The latter step involves the dual aspect of both fitting to the existing experimental data and satisfying abstract criteria like beauty, naturalness, etc. We use the Yukawa quark sector as a toy example to demonstrate how both of those tasks can be accomplished with machine learning techniques. We propose loss functions whose minimization results in true models that are also beautiful as measured by three different criteria — uniformity, sparsity, or symmetry.
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- 2024
- Full Text
- View/download PDF
20. Symplectic mechanics of relativistic spinning compact bodies I.: Covariant foundations and integrability around black holes
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Ramond, Paul
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General Relativity and Quantum Cosmology ,Mathematical Physics - Abstract
In general relativity, the motion of an extended body moving in a given spacetime can be described by a particle on a (generally non-geodesic) worldline. In first approximation, this worldline is a geodesic of the underlying spacetime, and the resulting dynamics admit a covariant and 4-dimensional Hamiltonian formulation. In the case of a Kerr background spacetime, the Hamiltonian was shown to be integrable by B.~Carter and the now eponymous constant. At the next level of approximation, the particle possesses proper rotation (hereafter \textit{spin}), which couples the curvature of spacetime and drives the representative worldline away from geodesics. In this article, we lay the theoretical foundations of a series of works aiming at exploiting the Hamiltonian nature of the equations governing the motion of a spinning particle, at linear order in spin. Our formalism is covariant and 10-dimensional. It handles the degeneracies inherent to the local Lorentz invariance of general relativity with tools from Poisson geometry, and accounts for the center-of-mass/spin-supplementary-condition using constrained Hamiltonian system theory. As a first application, we consider the linear-in-spin motion in a Kerr background. We show that the resulting Hamiltonian system admits exactly five functionally independent integrals of motion related to Killing symmetries, thereby proving that the system is integrable. We conclude that linear-in-spin corrections to the geodesic motion do not break integrability, and that the resulting trajectories are not chaotic. We explain how this integrability feature can be used to reduce the computational cost of waveform generation schemes for asymmetric binary systems of compact objects., Comment: 52 pages, 3 figures
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- 2022
21. Nambu and the Ising Model
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Brink, Lars and Ramond, Pierre
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High Energy Physics - Theory ,Condensed Matter - Statistical Mechanics ,Mathematical Physics - Abstract
In 2021, to mark the occasion of 2021 was Y\^oichir\^o Nambu's birth centenary, we engaged in writing a historical/scientific description of his most incisive papers. Nambu was the humblest genius we have known, and we expected to find some of his great but forgotten insights. We found one, written in 1947: ``A Note on the Eigenvalue Problem in Crystal Statistics", where he formulates and solves the $(N\times N)$ Ising model in a $2N$-dimensional Hilbert space
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- 2022
22. Tri-Bi-Maximal Mixing in Asymmetric Textures
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Ramond, Pierre
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High Energy Physics - Phenomenology - Abstract
At the occasion of his eighty fifth birthday, I wish to to recognize the crucial role that my advisor, Professor Ayalam Balachandran, played in enabling me to evolve from engineering to physics. So many years later, this student presents his latest efforts: the importance of asymmetry in the Yukawa matrices. We start with a purely phenomenological approach with Tri-Bi-Maximal mixing as input: it predicts the value of the CP-violating angle with the three mixing angles within one sigma of their pdf values. To ensure as much naturalness as possible, a model which starts from $SU_5$ and extends to $E_6$ is discussed, in the context of finite family groups which are subgroups $G_2$.
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- 2022
23. First Law of Mechanics for Spinning Compact Binaries: Dipolar Order
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Ramond, Paul and Tiec, Alexandre Le
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General Relativity and Quantum Cosmology - Abstract
Building upon the Noether charge formalism of Iyer and Wald, we derive a variational formula for spacetimes admitting a Killing vector field, for a generic energy-momentum distribution with compact support. Applying this general result to the particular case of a binary system of spinning compact objects moving along an exactly circular orbit, modelled using the multipolar gravitational skeleton formalism, we derive a first law of compact binary mechanics at dipolar order. We prove the equivalence of this new result with the canonical Hamiltonian first law previously derived for binary systems of spinning compact objects, for spins colinear with the orbital angular momentum. This paper paves the way to an extension of the first law of binary mechanics to the next quadrupolar order, thereby accounting for the spin-induced and tidally-induced deformability of the compact bodies., Comment: 44 pages, 3 figures
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- 2022
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24. Airway environment drives the selection of quorum sensing mutants and promote Staphylococcus aureus chronic lifestyle
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Xiongqi Ding, Catherine Robbe-Masselot, Xiali Fu, Renaud Léonard, Benjamin Marsac, Charlene J. G. Dauriat, Agathe Lepissier, Héloïse Rytter, Elodie Ramond, Marion Dupuis, Daniel Euphrasie, Iharilalao Dubail, Cécile Schimmich, Xiaoquan Qin, Jessica Parraga, Maria Leite-de-Moraes, Agnes Ferroni, Benoit Chassaing, Isabelle Sermet-Gaudelus, Alain Charbit, Mathieu Coureuil, and Anne Jamet
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Science - Abstract
Abstract Staphylococcus aureus is a predominant cause of chronic lung infections. While the airway environment is rich in highly sialylated mucins, the interaction of S. aureus with sialic acid is poorly characterized. Using S. aureus USA300 as well as clinical isolates, we demonstrate that quorum-sensing dysfunction, a hallmark of S. aureus adaptation, correlates with a greater ability to consume free sialic acid, providing a growth advantage in an air-liquid interface model and in vivo. Furthermore, RNA-seq experiment reveals that free sialic acid triggers transcriptional reprogramming promoting S. aureus chronic lifestyle. To support the clinical relevance of our results, we show the co-occurrence of S. aureus, sialidase-producing microbiota and free sialic acid in the airway of patients with cystic fibrosis. Our findings suggest a dual role for sialic acid in S. aureus airway infection, triggering virulence reprogramming and driving S. aureus adaptive strategies through the selection of quorum-sensing dysfunctional strains.
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- 2023
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25. Airway environment drives the selection of quorum sensing mutants and promote Staphylococcus aureus chronic lifestyle
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Ding, Xiongqi, Robbe-Masselot, Catherine, Fu, Xiali, Léonard, Renaud, Marsac, Benjamin, Dauriat, Charlene J. G., Lepissier, Agathe, Rytter, Héloïse, Ramond, Elodie, Dupuis, Marion, Euphrasie, Daniel, Dubail, Iharilalao, Schimmich, Cécile, Qin, Xiaoquan, Parraga, Jessica, Leite-de-Moraes, Maria, Ferroni, Agnes, Chassaing, Benoit, Sermet-Gaudelus, Isabelle, Charbit, Alain, Coureuil, Mathieu, and Jamet, Anne
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- 2023
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26. Assembly processes and functional diversity of marine protists and their rare biosphere
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Ramond, Pierre, Siano, Raffaele, Sourisseau, Marc, and Logares, Ramiro
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- 2023
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27. Factors associated with referral to physiotherapists for adult patients consulting for musculoskeletal disorders in primary care; an ancillary study to ECOGEN
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Peurois, M., Bertin, M., Fouquet, N., Adjeroud, N., Roquelaure, Y., and Ramond-Roquin, A.
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- 2023
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28. Rickettsia felis DNA recovered from a child who lived in southern Africa 2000 years ago
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Rifkin, Riaan F., Vikram, Surendra, Alcorta, Jaime, Ramond, Jean-Baptiste, Cowan, Don A., Jakobsson, Mattias, Schlebusch, Carina M., and Lombard, Marlize
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- 2023
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29. Diel and seasonal methane dynamics in the shallow and turbulent Wadden Sea
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T. R. de Groot, A. M. Mol, K. Mesdag, P. Ramond, R. Ndhlovu, J. C. Engelmann, T. Röckmann, and H. Niemann
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Ecology ,QH540-549.5 ,Life ,QH501-531 ,Geology ,QE1-996.5 - Abstract
The Wadden Sea is a coastal system along the fringe of the land–sea borders of Denmark, Germany and the Netherlands. The Wadden Sea is extremely productive and influenced by strong variations in physical and biological forcing factors that act on timescales of hours to seasons. Productive coastal seas are known to dominate the ocean's methane emission to the atmosphere, but knowledge of controls and temporal variations in methane dynamics in these vastly dynamic systems is scarce. Here we address this knowledge gap by measuring methane inventories and methanotrophic activity at a temporal resolution of 1 h over a period of 2 d, repeatedly during four successive seasons in the central Dutch Wadden Sea. We found that methane dynamics varied between colder and warmer seasons, with generally higher water column methane concentrations and methanotrophic activity in the warmer seasons. The efflux of methane to the atmosphere was, on the other hand, lower in the warmer seasons because of lower wind speeds. On a diel scale, tides controlled methanotrophic activity, which increased ∼40 % at low tide compared to high tide. We estimate that methane oxidizing bacteria reduce the methane budget of the Dutch Wadden Sea by only 2 %, while ∼1/3 escapes to the atmosphere and ∼2/3 are flushed out into the open North Sea at ebb tide. Our findings indicate that tides play a key role in controlling methane dynamics and methanotrophic activity and highlight the importance of high-resolution and repeated sampling strategies to resolve methane dynamics in fast-changing coastal systems.
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- 2023
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30. Water inputs across the Namib Desert: implications for dryland edaphic microbiology
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Bosch, Jason, Marais, Eugene, Maggs-Kölling, Gillian, Ramond, Jean-Baptiste, Lebre, Pedro H., Eckardt, Frank, and Cowan, Don A.
- Subjects
drylands ,hyper-arid ,Namib Desert ,relative humidity ,water availability - Abstract
Microbes have a dominant role in nutrient cycling processes in the world’s deserts, where growth and activity are limited by the availability of water. In order to understand the dynamics of water availability in a desert system and how it may affect the soil microbiome, we analysed soil temperature and relative humidity fluctuations recorded between April 2018 and April 2020 across a precipitation gradient in the Namib Desert and compared them with recorded data from satellites and nearby weather stations. This allowed us to assess the possible impact of fog and rain events in terms of biologically-available water. Using published literature on the water activity limits for various physiological processes in microorganisms, we were able to infer the annual ‘metabolic windows’ for desert microbial communities across the longitudinal precipitation gradient. Specifically, soil surface microbial communities were estimated to have the capacity for active growth for an average of 184- 363 hours per year with the duration heavily dependent on intermittent rainfall events. During the relatively wet period of April 2018 - March 2019, the maximum growth window was found in the hyper-arid central region of the transect (approximately 100 km from the coast). During the dryer 2019- 2020 period, there was almost no predicted growth capacity in the hyper-arid region but substantial metabolic windows both near the coast and for the eastern inland areas, where water input comes in the form of fog and moist coastal air, and higher rainfall, respectively. As the first detailed study of the temperature and relative humidity characteristics of Namib Desert near-surface soils, this study provides valuable insights into the biogeography of microbial communities. In addition, the estimates for organismal functionality calculated in this study offer a baseline for future quantitation of the impacts of climate change on the functional capacity of desert soil microbiomes.
- Published
- 2022
31. New Methods of Isochrone Mechanics
- Author
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Ramond, Paul and Perez, Jérôme
- Subjects
Mathematical Physics ,Astrophysics - Astrophysics of Galaxies ,37N05 - Abstract
Isochrone potentials, as defined by Michel H\'enon in the fifties, are spherically symmetric potentials within which a particle orbits with a radial period that is independent of its angular momentum. Isochrone potentials encompass the Kepler and harmonic potential, along with many other. In this article, we revisit the classical problem of motion in isochrone potentials, from the point of view of Hamiltonian mechanics. First, we use a particularly well-suited set of action-angle coordinates to solve the dynamics, showing that the well-known Kepler equation and eccentric anomaly parametrisation are valid for any isochrone orbit (and not just Keplerian ellipses). Second, by using the powerful machinery of Birkhoff normal forms, we provide a self-consistent proof of the isochrone theorem, that relates isochrone potentials to parabolae in the plane, which is the basis of all literature on the subject. Along the way, we show how some fundamental results of celestial mechanics such as the Bertrand theorem and Kepler's third law are naturally encoded in the formalism., Comment: 36 pages, 5 figures, 1 table
- Published
- 2021
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32. Synthesis of TiO2/SBA-15 Nanocomposites by Hydrolysis of Organometallic Ti Precursors for Photocatalytic NO Abatement
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Ons El Atti, Julie Hot, Katia Fajerwerg, Christian Lorber, Bénédicte Lebeau, Andrey Ryzhikov, Myrtil Kahn, Vincent Collière, Yannick Coppel, Nicolas Ratel-Ramond, Philippe Ménini, and Pierre Fau
- Subjects
mesoporous silica ,titanium(III) amidinate precursor ,TiO2 nanoparticles ,photocatalysis ,NO degradation ,air quality ,Inorganic chemistry ,QD146-197 - Abstract
The development of advanced photocatalysts for air pollution removal is essential to improve indoor air quality. TiO2/mesoporous silica SBA-15 nanocomposites were synthesized using an organometallic decoration method, which leverages the high reactivity of Ti precursors to be hydrolyzed on the surface water groups of silica supports. Both lab-made Ti(III) amidinate and commercial Ti(IV) amino precursors were utilized to react with water-rich SBA-15, obtained through a hydration process. The hydrated SBA-15 and the TiO2/SBA-15 nanocomposites were characterized using TGA, FTIR, 1H and 29Si NMR, TEM, SEM, N2 physisorption, XRD, and WAXS. This one-step TiO2 decoration method achieved a loading of up to 51.5 wt.% of approximately 9 nm anatase particles on the SBA-15 surface. This structuring provided excellent accessibility of TiO2 particles for photocatalytic applications under pollutant gas and UV-A light exposure. The combination with the high specific surface area of SBA-15 resulted in the efficient degradation of 400 ppb of NO pollutant gas. Due to synergistic effects, the best nanocomposite in this study demonstrated a NO abatement performance of 4.0% per used mg of TiO2, which is 40% more efficient than the reference photocatalytic material TiO2 P-25.
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- 2024
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33. Comparison of long-term natural aging to artificial aging in Duralumin
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Brunet, Magali, Malard, Benoit, Ratel-Ramond, Nicolas, Deshayes, Christophe, Warot-Fonrose, Bénédicte, Sciau, Philippe, and Douin, Joël
- Subjects
Condensed Matter - Materials Science - Abstract
The understanding of long-term aging of aeronautical materials, in particular aluminium alloys used in the fuselage and structure of aircraft is of extreme importance for airline fleets. In this work, a plate from an old aircraft (Breguet) was retrieved and studied in terms of microstructure and mechanical properties. A comparison was made between this naturally-aged alloy and a modern alloy on which different artificial aging conditions were applied. The old alloy exhibits a precipitation of $\theta$-Al2Cu at grain boundaries and of $\Omega$-Al2Cu on dispersoids. This non-expected nanostructure for an alloy in T4 state was attributed to the heat that the plate experienced during the aircraft cycles. However, it is shown that this aging is reversible (after a solution treatment). Moreover, the very long time of outdoors exposure seems to have caused intergranular corrosion causing the early failure during tensile tests on some of the specimens. The artificial aging (low temperature, 100{\textdegree}C for up to 10,000h) applied on the modern 2017A alloy did not allow to reproduce the nanostructure of the old plate, meaning that isothermal conditions for artificial aging might not be appropriate in this case.
- Published
- 2020
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34. Effect of ageing on the properties of the W-containing IRIS-TiAl alloy
- Author
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Couret, Alain, Reyes, David, Thomas, Marc, Ratel-Ramond, Nicolas, Deshayes, Christophe, and Monchoux, Jean-Philippe
- Subjects
Condensed Matter - Materials Science ,Physics - Classical Physics - Abstract
The effects of ageing at 800 $^\circ$C on the properties of the IRIS alloy (Ti$_{49.9}$Al$_{48}$W$_2$B$_{0.1}$) are studied. The initial microstructure of this alloy densified by Spark Plasma Sintering (SPS) is mainly composed of lamellar colonies which are surrounded by $\gamma$ grains. The evolutions of the alloy strength and creep resistance resulting from this ageing treatment are measured by the related mechanical tests. The microstructural changes are investigated by scanning and transmission electron microscopies and by X-ray diffraction. The main structural evolutions consist in a shrinkage of the lamellar areas and in a precipitation of $\beta_0$ phase, which is accompanied by a moderate segregation of tungsten and a decrease of the $\alpha_2$ lamellar width. However, these evolutions are relatively limited and the microstructural stability is found to result mainly from the low diffusivity of tungsten. Conversely, a moderate effect of this ageing treatment on mechanical properties, at room and high temperatures, is measured. Such experimental results are interpreted and discussed in terms of the microstructural evolutions and of the deformation mechanisms which are activated at different temperatures under various solicitations.
- Published
- 2020
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- View/download PDF
35. Burden of Pertussis in Adults Aged 50 Years and Older: A Retrospective Database Study in England
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Harrington, Lauriane, Aris, Emmanuel, Bhavsar, Amit, Jamet, Nicolas, Akpo, Essè Ifèbi Hervé, Simeone, Jason C., Ramond, Anna, Lambrelli, Dimitra, Oppenheimer, John, Sergerie, Yan, Mukherjee, Piyali, and Meszaros, Kinga
- Published
- 2023
- Full Text
- View/download PDF
36. Diamonds in the rough: Dryland microorganisms are ecological engineers to restore degraded land and mitigate desertification
- Author
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Ramona Marasco, Jean‐Baptiste Ramond, Marc W. Van Goethem, Federico Rossi, and Daniele Daffonchio
- Subjects
Biotechnology ,TP248.13-248.65 - Abstract
Abstract Our planet teeters on the brink of massive ecosystem collapses, and arid regions experience manifold environmental and climatic challenges that increase the magnitude of selective pressures on already stressed ecosystems. Ultimately, this leads to their aridification and desertification, that is, to simplified and barren ecosystems (with proportionally less microbial load and diversity) with altered functions and food webs and modification of microbial community network. Thus, preserving and restoring soil health in such a fragile biome could help buffer climate change's effects. We argue that microorganisms and the protection of their functional properties and networks are key to fight desertification. Specifically, we claim that it is rational, possible and certainly practical to rely on native dryland edaphic microorganisms and microbial communities as well as dryland plants and their associated microbiota to conserve and restore soil health and mitigate soil depletion in newly aridified lands. Furthermore, this will meet the objective of protecting/stabilizing (and even enhancing) soil biodiversity globally. Without urgent conservation and restoration actions that take into account microbial diversity, we will ultimately, and simply, not have anything to protect anymore.
- Published
- 2023
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37. Assembly processes and functional diversity of marine protists and their rare biosphere
- Author
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Pierre Ramond, Raffaele Siano, Marc Sourisseau, and Ramiro Logares
- Subjects
Community assembly ,Rare biosphere ,Marine protists ,Community ecology ,Functional ecology ,Environmental sciences ,GE1-350 ,Microbiology ,QR1-502 - Abstract
Abstract Background The mechanisms shaping the rare microbial biosphere and its role in ecosystems remain unclear. We developed an approach to study ecological patterns in the rare biosphere and use it on a vast collection of marine microbiomes, sampled in coastal ecosystems at a regional scale. We study the assembly processes, and the ecological strategies constituting the rare protistan biosphere. Using the phylogeny and morpho-trophic traits of these protists, we also explore their functional potential. Results Taxonomic community composition remained stable along rank abundance curves. Conditionally rare taxa, driven by selection processes, and transiently rare taxa, with stochastic distributions, were evidenced along the rank abundance curves of all size-fractions. Specific taxa within the divisions Sagenista, Picozoa, Telonemia, and Choanoflagellida were rare across time and space. The distribution of traits along rank abundance curves outlined a high functional redundancy between rare and abundant protists. Nevertheless, trophic traits illustrated an interplay between the trophic groups of different size-fractions. Conclusions Our results suggest that rare and abundant protists are evolutionary closely related, most notably due to the high microdiversity found in the rare biosphere. We evidenced a succession of assembly processes and strategies of rarity along rank abundance curves that we hypothesize to be common to most microbiomes at the regional scale. Despite high functional redundancy in the rare protistan biosphere, permanently rare protists were evidenced, and they could play critical functions as bacterivores and decomposers from within the rare biosphere. Finally, changes in the composition of the rare protistan biosphere could be influenced by the trophic regime of aquatic ecosystems. Our work contributes to understanding the role of rare protists in microbiomes.
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- 2023
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38. Documenting the diversity of the Namibian Ju|’hoansi intestinal microbiome
- Author
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Mia Truter, Jessica E. Koopman, Karen Jordaan, Leon Oma Tsamkxao, Don A. Cowan, Simon J. Underdown, Jean-Baptiste Ramond, and Riaan F. Rifkin
- Subjects
CP: Microbiology ,Biology (General) ,QH301-705.5 - Abstract
Summary: We investigate the bacterial and fungal composition and functionality of the Ju|’hoansi intestinal microbiome (IM). The Juǀʼhoansi are a hunter-gatherer community residing in northeastern Namibia. They formerly subsisted by hunting and gathering but have been increasingly exposed to industrial dietary sources, medicines, and lifestyle features. They present an opportunity to study the evolution of the human IM in situ, from a predominantly hunter-gatherer to an increasingly Western urban-forager-farmer lifestyle. Their bacterial IM resembles that of typical hunter-gatherers, being enriched for genera such as Prevotella, Blautia, Faecalibacterium, Succinivibrio, and Treponema. Fungal IM inhabitants include animal pathogens and plant saprotrophs such as Fusarium, Issatchenkia, and Panellus. Our results suggest that diet and culture exert a greater influence on Ju|’hoansi IM composition than age, self-identified biological sex, and medical history. The Ju|’hoansi exhibit a unique core IM composition that diverges from the core IMs of other populations.
- Published
- 2024
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39. Abel-Ruffini's Theorem: Complex but Not Complicated!
- Author
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Ramond, Paul
- Subjects
Mathematics - History and Overview ,Mathematics - Algebraic Geometry - Abstract
In this article, using only elementary knowledge of complex numbers, we sketch a proof of the celebrated Abel--Ruffini theorem, which states that the general solution to an algebraic equation of degree five or more cannot be written using radicals, that is, using its coefficients and arithmetic operations $+,-,\times,\div,$ and $\sqrt{\ }$. The present article is written purposely with concise and pedagogical terms and dedicated to students and researchers not familiar with Galois theory, or even group theory in general, which are the usual tools used to prove this remarkable theorem. In particular, the proof is self-contained and gives some insight as to why formulae exist for equations of degree four or less (and how they are constructed), and why they do not for degree five or more., Comment: 9 pages, 6 figures
- Published
- 2020
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40. An example of resonance instability
- Author
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Bony, Jean-Francois, Fujiie, Setsuro, Ramond, Thierry, and Zerzeri, Maher
- Subjects
Mathematics - Spectral Theory ,Mathematical Physics ,Mathematics - Analysis of PDEs ,35B34, 35B35, 81Q20, 37C25, 35J10, 35P20 - Abstract
We construct a semiclassical Schr\"{o}dinger operator such that the imaginary part of its resonances closest to the real axis changes by a term of size $h$ when a real compactly supported potential of size $o ( h )$ is added., Comment: 14 pages, 6 figures
- Published
- 2020
41. Multipolar Particles in Helically Symmetric Spacetimes
- Author
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Ramond, Paul and Tiec, Alexandre Le
- Subjects
General Relativity and Quantum Cosmology - Abstract
We consider a binary system of spinning compact objects with internal structure, moving along an exactly circular orbit, and modelled within the multipolar gravitational skeleton formalism, up to quadrupolar order. We prove that the worldline of each multipolar particle is an integral curve of the helical Killing vector field, and that the 4-velocity, 4-momentum, spin tensor and quadrupole tensor of each particle are Lie-dragged along those worldlines. The geometrical framework developed in this paper paves the way to an extension of the first law of compact-object binary mechanics up to quadrupolar order., Comment: 37 pages, 2 figures
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- 2020
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42. The Geometry of Isochrone Orbits: from Archimedes' parabolae to Kepler's third law
- Author
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Ramond, Paul and Perez, Jérôme
- Subjects
Physics - Classical Physics ,Astrophysics - Astrophysics of Galaxies ,Mathematical Physics - Abstract
In classical mechanics, the Kepler potential and the Harmonic potential share the following remarkable property: in either of these potentials, a bound test particle orbits with a radial period that is independent of its angular momentum. For this reason, the Kepler and Harmonic potentials are called \it{isochrone}. In this paper, we solve the following general problem: are there any other isochrone potentials, and if so, what kind of orbits do they contain? To answer these questions, we adopt a geometrical point of view initiated by Michel H\'enon in 1959, in order to explore and classify exhaustively the set of isochrone potentials and isochrone orbits. In particular, we provide a geometric generalization of Kepler's third law, and give a similar law for the apsidal angle, for any isochrone orbit. We also relate the set of isochrone orbits to the set of parabolae in the plane under linear transformations, and use this to derive an analytical parameterization of any isochrone orbit. Along the way we compare our results to known ones, pinpoint some interesting details of this mathematical physics problem, and argue that our geometrical methods can be exported to more generic orbits in potential theory., Comment: 54 pages, 18 figures
- Published
- 2020
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43. The Freund-Rubin Coset, Textures and Group Theory
- Author
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Ramond, Pierre
- Subjects
High Energy Physics - Theory - Abstract
Contribution to the Peter Freund Memorial volume: a glossary of group-theoretic facts that may relate the seven-dimensional Freund-Rubin coset to Yukawa textures., Comment: 10 pages
- Published
- 2020
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44. Tribimaximal Mixing in the $SU(5) \times \mathcal{T}_{13}$ Texture
- Author
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Pérez, M. Jay, Rahat, Moinul Hossain, Ramond, Pierre, Stuart, Alexander J., and Xu, Bin
- Subjects
High Energy Physics - Phenomenology - Abstract
We extend the recently proposed $SU(5) \times \mathcal{T}_{13}$ model for the asymmetric texture to the up-type quark and seesaw sectors. The hierarchical up-type quark masses are generated from higher-dimensional operators involving family-singlet Higgses, gauge-singlet familons, and vectorlike messengers. The complex-tribimaximal (TBM) seesaw mixing arises from the vacuum structure of a minimal number of familons, resulting in an alignment between the Yukawa and Majorana matrices of the seesaw formula. Introducing four right-handed neutrinos, normal ordering of the light neutrino masses is obtained, with $m_{\nu_1} = 27.6\ \mathrm{meV}$, $m_{\nu_2} = 28.9\ \mathrm{meV}$ and $m_{\nu_3} = 57.8\ \mathrm{meV}$. Their sum almost saturates Planck's cosmological upper bound ($120$ $\text{meV}$). The right-handed neutrino masses are expressed in terms of two parameters for a particular choice of familon vacuum alignment. We predict the $\require{cancel}\cancel{CP}$ Jarlskog-Greenberg invariant to be $|\mathcal{J}| = 0.028$, consistent with the current PDG estimate, and Majorana invariants $|\mathcal{I}_1| = 0.106$ and $|\mathcal{I}_2| = 0.011$. A sign ambiguity in the model parameters leads to two possibilities for the invariant mass parameter $|m_{\beta \beta}|$: $13.02$ or $25.21$ $\text{meV}$, both within an order of magnitude of the most rigorous experimental upper limit ($61$--$165$ $\text{meV}$)., Comment: 36 pages, 2 figures, minor changes to match with the published version
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- 2020
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45. Applications of resonance theory without analyticity assumption
- Author
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Bony, Jean-Francois, Michel, Laurent, and Ramond, Thierry
- Subjects
Mathematics - Analysis of PDEs ,Mathematical Physics ,Mathematics - Spectral Theory ,35B34, 35P25, 81Q20, 35J10, 35S05, 47A10 - Abstract
We prove that the results in scattering theory that involve resonances are still valid for non-analytic potentials, even if the notion of resonance is not defined in this setting. More precisely, we show that if the potential of a semiclassical Schr\"odinger operator is supposed to be smooth and to decrease at infinity, the usual formulas relating scattering quantities and resonances still hold. The main ingredient for the proofs is a resolvent estimate of a new type, relating the resolvent of an operator with the resolvent of its cut-off counterpart., Comment: 49 pages, 12 figures
- Published
- 2019
46. Burden of Pertussis in Adults Aged 50 Years and Older: A Retrospective Database Study in England
- Author
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Lauriane Harrington, Emmanuel Aris, Amit Bhavsar, Nicolas Jamet, Essè Ifèbi Hervé Akpo, Jason C. Simeone, Anna Ramond, Dimitra Lambrelli, John Oppenheimer, Yan Sergerie, Piyali Mukherjee, and Kinga Meszaros
- Subjects
Direct medical costs ,Health care resource utilisation ,Incidence ,Pertussis ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Introduction Pertussis, a highly infectious respiratory disease caused by Bordetella pertussis, affects people of all ages. Older adults are particularly susceptible to its severe outcomes and complications. Methods In this retrospective cohort study, the incidence rate of pertussis among individuals aged ≥ 50 years was assessed during 2009–2018 using Clinical Practice Research Datalink and Hospital Episode Statistics databases, United Kingdom. Health care resource utilisation (HCRU) and direct medical costs (DMCs) were compared between patients with a pertussis diagnosis and propensity score-matched controls (matched on demographic and clinical variables). Results Among 5,222,860 individuals, 1638 had a pertussis diagnosis (incidence rate: 5.8 per 100,000 person-years; 95% confidence interval 5.5–6.0). Baseline (– 18 to – 6 months) HCRU and DMC were similar among 1480 pertussis patients and 1480 matched controls. However, there were increases in HCRU in the pertussis vs. matched cohort around the pertussis diagnosis (from months – 6 to – 1 to 5–11). The most notable increases (pertussis vs. controls) were in the rates of general practitioner (GP)/nurse visits (4.7-fold), clinical assessments (4.1-fold), and accident and emergency visits (3.0-fold) during the month before diagnosis and GP/nurse visits during the 2 months after diagnosis (2.5-fold) (all p
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- 2023
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47. Rickettsia felis DNA recovered from a child who lived in southern Africa 2000 years ago
- Author
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Riaan F. Rifkin, Surendra Vikram, Jaime Alcorta, Jean-Baptiste Ramond, Don A. Cowan, Mattias Jakobsson, Carina M. Schlebusch, and Marlize Lombard
- Subjects
Biology (General) ,QH301-705.5 - Abstract
Ancient genomic evidence for Rickettsia felis presence in human remains from 2000 years ago reframes previous hypotheses of R. felis as a novel or emergent pathogen in modern humans.
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- 2023
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- View/download PDF
48. Stitching an Asymmetric Texture with $\mathcal{T}_{13} \times \mathcal{Z}_5$ Family Symmetry
- Author
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Pérez, M. Jay, Rahat, Moinul Hossain, Ramond, Pierre, Stuart, Alexander J., and Xu, Bin
- Subjects
High Energy Physics - Phenomenology - Abstract
We propose $\mathcal{T}_{13} = \mathcal{Z}_{13} \rtimes \mathcal{Z}_3$ as the underlying non-Abelian discrete family symmetry of the asymmetric texture presented in arXiv:1805.10684 [hep-ph]. Its mod 13 arithmetic distinguishes each Yukawa matrix element of the texture. We construct a model of effective interactions that singles out the asymmetry and equates, without fine-tuning, the products of down-quark and charged-lepton masses at a GUT-like scale., Comment: Major change from previous version: the symmetry $\mathcal{Z}_4$ has been changed to $\mathcal{Z}_5$ to prohibit a new unwanted vertex, 26 pages, version accepted for publication in Physical Review D
- Published
- 2019
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49. Neutrinos and Particle Physics Models
- Author
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Ramond, Pierre
- Subjects
Physics - History and Philosophy of Physics ,High Energy Physics - Phenomenology - Abstract
As in Greek mythology, the neutrino was born in the mind of Wolfgang Pauli to salvage a fundamental principle. Its existence met with universal skepticism by a scientific community used to infer particles from experiment. Its detection in 1956 brought particle physics acceptance; its chirality explained maximal parity violation in $\beta$ decay; its (apparent) masslessness led theorists to imagine new symmetries. Neutrinos are pioneers of mutli-messenger astronomy, from the Sun, from SNA1987, and now through IceCube's blazar. The discovery of neutrino masses opened a new era in particle physics aswell as unexplored windows on the universe. -Tiny neutrino masses suggest new physics at very short distances through the Seesaw. - Neutrinos and quarks, unified by gauge structure, display different mass and mixing patterns: small quark mixing angles and two large neutrino mixing angles. This difference in mass and mixings in the midst of gauge unification may be an important clue towards Yukawa unification. - Neutrino mixings provide a new source of CP-violation, and may solve the riddle of matter-antimatter asymmetry. We present a historical journey of these "enfants terribles" of particle physics and their importance in understanding our universe., Comment: Invited Talk at the "History of the Neutrino" Conference, September 2018, Paris
- Published
- 2019
50. Factors associated with referral to physiotherapists for adult patients consulting for musculoskeletal disorders in primary care; an ancillary study to ECOGEN
- Author
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M. Peurois, M. Bertin, N. Fouquet, N. Adjeroud, Y. Roquelaure, and A. Ramond-Roquin
- Subjects
Physiotherapy ,Musculoskeletal disorder ,Primary health care ,Multilevel analysis ,Medicine (General) ,R5-920 - Abstract
Abstract Background Musculoskeletal disorders (MSD) are multifactorial requiring multidisciplinary treatment including physiotherapy. General practitioners (GP) have a central role in managing MSDs and mostly solicit physiotherapists accounting for 76.1% of physiotherapy referrals in France. Patient, physician, and contextual factors, including healthcare accessibility, can influence physiotherapy referral rates. Objective To identify patient, physician, and contextual factors associated with physiotherapy referral in adult patients with MSDs in general practice. Methods This study is based on the 2011/2012 French cross-sectional ECOGEN study. Analyses included working-age patients consulting their GP for any MSD. Physiotherapy referral was assessed initially, then adjusted multilevel logistic model analysis of patient, physician, geographical area-related factors associated with these referrals was performed. Results Among the 2305 patients included, 456 (19.8%) were referred to a physiotherapist. Following multilevel multivariate analyses, physiotherapist referral was more frequent for female patients (OR 1.28; 95% CI [1.03, 1.59]) with spinal (OR 1.47; 95% CI [1.18, 1.83]) and upper limb disorders (OR 1.66; 95% CI [1.20, 2.29]), and less frequent for patients ≥ 50 years (OR 0.69; 95% CI [0.52, 0.91]), living in deprived geographical areas (OR 0.60; 95% CI [0.40, 0.90]). GPs referred to a physiotherapist less frequently if they were ≥ 50 years (OR 0.50; 95% CI [0.39, 0.63]), had a high number of annual consultations, or were practicing in semi-urban area in a multidisciplinary team. Conclusion This multilevel analysis identifies factors associated with physiotherapy referral for patients with MSDs, including living in deprived geographical areas. This constitutes an original contribution towards addressing healthcare disparities.
- Published
- 2023
- Full Text
- View/download PDF
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