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Electron polytropic exponent in the plasma plume of a high power Hall thruster firing with xenon and krypton
No full textInternational audienceLangmuir probe measurements were performed in the downstream region of the plasma plume of a high power Hall thruster fired with both xenon and krypton as propellant for input powers from 3 kW up to 6 kW. Our analysis shows that the measured electron energy distribution function is well fitted with a Druyvesteyn distribution, especially for large electron energies. Angular profiles of the electron density and temperature have been determined for many operating conditions. The electron density is larger for xenon while the electron temperature is larger for krypton, as a consequence of the ionization energy difference. Combining density and temperature data, the electron polytropic exponent γ e was computed. In the far-field, the value of the exponent is below the value of an adiabatic expansion (5/3) in agreement with previous works. The exponent is larger for krypton than for xenon. Surprisingly, the value of the exponent remains independent of the angular position in spite of significant variations in electron density and temperature with the angle
On the Design of Interval Observers for Discrete-Time Linear Switched Systems without Using Similarity Transformations
No full textInternational audienceThis paper presents synthesis methods of IntervalObservers (IO) for discrete-time linear switched systems subjectto additive unknown-but-bounded process and measurementnoises. The novelty of the proposed methods consists in thedesigning of IO directly in the original state coordinates ofthe systems. This enables to: (i) mitigating the wrappingeffect related to the classical use of similarity transformations;(ii) avoiding the impulsive behavior of the estimation errordynamics, mostly generated by the use of different similaritytransformation for each mode of the switched system; (iii)reducing online computational effort. In addition, BilinearMatrix Inequalities (BMI) and Linear Matrix Inequalities(LMI) conditions are established to check the existence andto compute stabilizing observer gains. The obtained theoreticalresults are supported by numerical simulations
Multidimensional assessment of the potential of insects for sustainable agri-food systems
No full textInternational audienceThis study presents a multidimensional framework to evaluate the socioecological roles (SER) of insects in agrifood systems. Insects contribute to all four categories of ecosystem services: provisioning, regulating, supporting, and cultural, while also posing context-specific challenges. Using a transdisciplinary approach, we assessed 120 insect species across four dimensions: Productive Potential, Ecosystem Potential, Use, and Challenges. Unsupervised machine learning identified species clusters that provide useful insights for context-specific management strategies, including conservation, pest/vector control, wild gathering, and farming. While some species consistently perform well across dimensions, others require more localised or tailored approaches. Rather than offering definitive answers, this framework provides a starting point to support more adaptive and inclusive decision-making for sustainable insect use. It contributes to balancing productivity, biodiversity, and cultural relevance, while guiding future research and policy efforts aligned with agri-food system transformation and biodiversity goals
Exploring the taxonomic status of the Palearctic cone weevil, Pissodes validirostris, inferred from morphometric and molecular data
No full textInternational audienceThe Scots pine cone weevil, Pissodes validirostris Gyll. (Coleoptera: Curculionidae) widely distributed from Europe, across to North-Eastern China, consumes the cones of Mediterranean pines, as well those of the sylvestris section. The use of multiple host pine species with limited and patchy distributions, combined with low dispersal rates, likely contributed to significant genetic and morphological variation among P. validirostris populations in its native range. P. validirostris is being considered as a biological control agent for wilding pines in the southern hemisphere and for this programme to proceed, elucidating its intraspecific variability is necessary. This study aimed to explore the phylogeography of P. validirostris in its native range in Europe using mitochondrial and nuclear genetic markers as well as morphological characters. The integrative taxonomic analysis revealed high genetic structuring in P. validirostris populations, identifying three main phylogeographic clades: Clade A (Iberian Peninsula, associated with Pinus pinaster and Pinus halepensis ), Clade B (Central Europe), and Clade C (Northern and Eastern Europe), both associated with Pinus species of the sylvestris section. The morphometric data showed that adults of the Iberic Peninsula clade were significantly larger than those of the two others. When compared to other Nearctic and Palearctic congeneric species, P. validirostris formed a monophyletic group, likely consisting of different evolutionary lineages within the sampled distribution. The findings highlight the necessity of genetic confirmation for insect taxonomy across wide distributions or multiple host trees. Clarifying whether host specificity or geography drives P. validirostris population structuring will facilitate the selection of a specific clade for wilding pine biological control
Physiological Mechanisms Underlying the Primary Respiratory Mechanism (PRM) and Cranial Rhythmic Impulse (CRI) in Osteopathy: A Narrative Review of the Literature
No full textInternational audienceCranial Rhythmic Impulse (CRI) or Primary Respiratory Mechanism (PRM), a rhythm felt by Osteopaths at the surface of the skin, is a fundamental concept that some of them in their practice for their diagnosis and treatment. However, the physiological basis of this phenomenon remains unclear. Sutherland, founder of cranial osteopathy, proposed in 1939 a theory that remained dogmatic, despite scientific advances that refuted it. Since 1990, some osteopaths have tried to find better explanations, such as those presented in a previous systematic review. In this narrative review, we first revisit each pillar of Sutherland’s theory, analyzing them in light of the latest scientific studies to assess whether contemporary research supports or challenges his ideas. After showing that this model is inconsistent with current scientific evidence, we explore the current knowledge of the physiological mechanisms underlying the PRM/CRI. The most plausible hypothesis to explain this is based on the variation in extracellular matrix and fascial texture, influenced by rhythmic oscillations in blood pressure (Traube Hering and Mayer waves), and the interplay of other physiological rhythms (ventilation, baroreflex, heart rate variability…). Finally, we discuss the relevance and practical applications of PRM in osteopathy. While Sutherland's model continues to hold sway in mainstream beliefs, the scientific literature has increasingly emphasized autonomic system activity as the leading hypothesis. This narrative analysis underscores the need for a paradigm shift regarding CRI/PRM in osteopathy, arguing for clearer communication of a model aligned with the latest scientific evidence
Corpus medievale. Propos sur le corps dans la littérature médiévale
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FT-IR Analysis Of Aerosols In Microgravity
No full textInternational audienceThis work demonstrates the possibility of analyzing aerosols under microgravity conditions using optical microtomography and FT-IR analysis simultaneously. The combination of these two techniques provides access to both the chemical composition and the size distribution of the droplets, opening up interesting prospects for the description of droplet nucleation and evaporation in gas mixtures
Income Shocks, Bride Price, and Child Marriage in Turkey
No full textInternational audienceAbstract Early marriage persists in many countries in spite of legal prohibition. The role of income shocks and bride price norms is investigated in the context of Turkey. Using data from the Turkey Demographic and Health Surveys 1998 to 2018, rainfall shocks are exploited as an exogenous source of variation of household income. To study the role of marital payments, measures of shocks are interacted with a province-level indicator based on past prevalence of bride price. Estimation results show that girls exposed to a large negative shock during adolescence have a higher probability of being married before 15, if living in provinces with a high prevalence of bride price. More arranged and forced marriages are found after severe shocks in those provinces. Results suggest that daughter marriage, as a response to mitigate negative income shocks, is not limited to the poorest countries, and still contributes to household strategies in Turkey
White Rabbit development on Altera platform
No full textInternational audienceIn this presentation, we will showcase the metrological evaluation of a newly developed electronic architecture—a custom carrier board built around the Altera Arria10 FPGA—which integrates White Rabbit technology. This system is an original platform tailored for high-performance frequency and time distribution, as well as precise timing capture for phased-array detectors. We will present detailed performance results, highlighting outstanding short-term jitter and long-term stability of the generated clock and Pulse-Per-Second signals. These results demonstrate cutting-edge timing precision and spectral purity in FPGA-based time transfer systems, with impactful implications for time-frequency metrology, radio astronomy, particle physics, and distributed instrumentation, particularly in systems relying on optical fiber networks
Aristote, agent de propagande macédonien ?: Lecture critique d'une hypothèse de Hans Kelsen
No full textInternational audiencePar un travail de contextualisation historique et biographique, Hans Kelsen, dans son article « La Politique gréco-macédonienne et la politique d’Aristote » (1933), soutient l’idée que la Métaphysique, la Politique et l’Éthique d’Aristote sont les pièces d’un même puzzle idéologique dont le but était de promouvoir la monarchie héréditaire macédonienne. Ce travail de contextualisation souffre toutefois de certaines faiblesses méthodologiques qu’il n’est pas possible d’ignorer