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The PLATO mission
No full textPLATO (PLAnetary Transits and Oscillations of stars) is ESA’s M3 mission designed to detect and characterise extrasolar planets and perform asteroseismic monitoring of a large number of stars. PLATO will detect small planets (down to <2REarth) around bright stars (<11 mag), including terrestrial planets in the habitable zone of solar-like stars. With the complement of radial velocity observations from the ground, planets will be characterised for their radius, mass, and age with high accuracy (5%, 10%, 10% for an Earth-Sun combination respectively). PLATO will provide us with a large-scale catalogue of well-characterised small planets up to intermediate orbital periods, relevant for a meaningful comparison to planet formation theories and to better understand planet evolution. It will make possible comparative exoplanetology to place our Solar System planets in a broader context. In parallel, PLATO will study (host) stars using asteroseismology, allowing us to determine the stellar properties with high accuracy, substantially enhancing our knowledge of stellar structure and evolution. The payload instrument consists of 26 cameras with 12cm aperture each. For at least four years, the mission will perform high-precision photometric measurements. Here we review the science objectives, present PLATO‘s target samples and fields, provide an overview of expected core science performance as well as a description of the instrument and the mission profile towards the end of the serial production of the flight cameras. PLATO is scheduled for a launch date end 2026. This overview therefore provides a summary of the mission to the community in preparation of the upcoming operational phases.</p
Analyse de pratiques, évaluation et rapport à la (aux) norme (s):quels risques? de déprofessionnalisation(s)?
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From Constituency to Continent? Measuring the Shift of Territorial Representational Focus in MEPs' Parliamentary Activity (1994-2024)
Get PDFAs a supranational legislative institution, the European Parliament (EP) is known to put a particular pressure on its members (MEPs) when fulling their mandates. MEPs are famously known for being “the servants of two masters”, i.e. they must serve the interests of their domestic (s)electorate from the territorial districts they were elected in, while being loyal to their European party groups in the EP. This situation is particularly challenging when MEPs face conflicting interests from competing principals. Yet, this situation is not specific to the EP but rather reflects the inevitable “compounded representation” at the heart of federal political systems. In these systems, there is a trade-off balancing “self-rule” with “shared rule” as federal systems present parliamentarians with a classic representational dilemma: standing up for their specific constituency versus addressing the broader interests of the wider polity. This research note analyses how MEPs balance this compounded representation in their parliamentary activity. Because of the continuous extension of EU policy-making powers over the last decades (Maastricht 1993, Amsterdam 1999, Lisbon 2009), along with the institutionalization and empowerment of the EP in the decision-making processes, this analysis is of particular interest for both scholars of European and legislative studies. Have MEPs been shifting their territorial focus as the influence of the EP was increasing? On the opposite, do they remain foremost representatives of national interests? To answer these questions, we introduce a novel conceptualization of territorial representational focus, operationalizing it as a spectrum ranging from localized (constituency-focused) to polity-wide (supranational European) representation. Drawing on a comprehensive dataset spanning three decades (1994–2024) and encompassing the careers of 3,654 Members of the European Parliament (MEPs) who tabled 187,612 parliamentary questions, we present the first systematic measurement of territorial representational focus in parliamentary activity. For that task, we leverage several natural language processing (NLP) techniques, transformer-based models and Retrieval-Augmented Generation (RAG) capabilities. Our findings reveal how territorial focus in MEPs’ questions evolved over time while varying across policy domains, EPGs, countries and MEPs’ seniority. Overall, our approach lays the groundwork for future research by offering a new empirical tool to study territorial representational tensions in MEPs’ parliamentary behaviour.<br/
Advancing the Spatiotemporal Dimension of Wildlife–Pollution Interactions
Get PDFChemical pollution is one of the fastest-growing agents of global change. Numerous pollutants are known to disrupt animal behavior, alter ecological interactions, and shift evolutionary trajectories. Crucially, both chemical pollutants and individual organisms are nonrandomly distributed throughout the environment. Despite this fact, the current evidence for chemical-induced impacts on wildlife largely stems from tests that restrict organism movement and force homogeneous exposures. While such approaches have provided pivotal ecotoxicological insights, they overlook the dynamic spatiotemporal interactions that shape wildlife–pollution relationships in nature. Indeed, the seemingly simple notion that pollutants and animals move nonrandomly in the environment creates a complex of dynamic interactions, many of which have never been theoretically modeled or experimentally tested. Here, we conceptualize dynamic interactions between spatiotemporal variation in pollutants and organisms and highlight their ecological and evolutionary implications. We propose a three-pronged approach─integrating in silico modeling, laboratory experiments that allow movement, and field-based tracking of free-ranging animals─to bridge the gap between controlled ecotoxicological studies and real-world wildlife exposures. Advances in telemetry, remote sensing, and computational models provide the necessary tools to quantify these interactions, paving the way for a new era of ecotoxicology that accounts for spatiotemporal complexity
Efficient first-principles evaluation of thermodynamic stability, physical properties and photocatalytic performance of alkali-metal tantalates
Get PDFWe report the structure, stability, electronic, optical, and photocatalytic properties of sodium and potassium tantalates (NaTaO3 and KTaO3) by employing meta-GGA level DFT calculations. Our results show that the structural, mechanical, vibrational, and energetic properties computed using SCAN meta-GGA are in excellent agreement with experimental data compared to earlier calculations performed using semi-local and hybrid-DFT calculations. Moreover, we also show that the employment of TB09 meta-GGA with spin-orbit coupling facilitates reliable description of the electronic properties of NaTaO3 and KTaO3. The optical absorption coefficients of orthorhombic NaTaO3 and cubic KTaO3 are also reported and their potential for photocatalytic hydrogen production from overall water molecule splitting has been examined. Our results clearly show that accurate determination of physical properties of NaTaO3 and KTaO3 can be achieved by combining SCAN and TB09 meta-GGAs at a significantly lower computational cost compared to computationally demanding hybrid-DFT and GW calculations.</p
Strategy to control synchronized dynamics in swarmalator systems
Get PDFSynchronization forms the basis of many coordination phenomena in natural systems, enabling them to function cohesively and support their fundamental operations. However, there are scenarios where synchronization disrupts a system's proper functioning, necessitating mechanisms to control or suppress it. While several methods exist for controlling synchronization in nonspatially embedded oscillators, to the best of our knowledge, no such strategies have been developed for swarmalators (oscillators that simultaneously move in space and synchronize in time). In this work, we address this gap by introducing a control strategy based on Hamiltonian control theory to suppress synchronization in a system of swarmalators confined to a one-dimensional space. The numerical investigations we performed demonstrate that the proposed control strategy effectively suppresses synchronized dynamics within the swarmalator population. We studied the impact of the number of controlled swarmalators and the strength of the control term in its original form and a simplified one