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After their birth a significant fraction of all stars pass through the tidal threshold (prah) of their cluster of origin into the classical tidal tails. The asymmetry between the number of stars in the leading and trailing tails tests gravitational theory. All five open clusters with tail data (Hyades, Praesepe, Coma Berenices, COIN-Gaia 13, NGC 752) have visibly more stars within dcl = 50 pc of their centre in their leading than their trailing tail. Using the Jerabkova-compact-convergent-point (CCP) method, the extended tails have been mapped out for four nearby 600-2000 Myr old open clusters to dcl>50 pc. These are on near-circular Galactocentric orbits, a formula for estimating the orbital eccentricity of an open cluster being derived. Applying the Phantom of Ramses code to this problem, in Newtonian gravitation the tails are near-symmetrical. In Milgromian dynamics (MOND) the asymmetry reaches the observed values for 50 < dcl/pc < 200, being maximal near peri-galacticon, and can slightly invert near apo-galacticon, and the Küpper epicyclic overdensities are asymmetrically spaced. Clusters on circular orbits develop orbital eccentricity due to the asymmetrical spill-out, therewith spinning up opposite to their orbital angular momentum. This positive dynamical feedback suggests Milgromian open clusters to demise rapidly as their orbital eccentricity keeps increasing. Future work is necessary to better delineate the tidal tails around open clusters of different ages and to develop a Milgromian direct n-body code., 28 pages, 19 figures, MNRAS, published

Laser-induced cavitation bubble dynamics at different distances from a rigid boundary is investigated using high-speed synchrotron x-ray phase-contrast imaging. This is achieved through the design of a tailored experimental chamber specifically designed to reduce the x-ray absorption along the path length in water while mitigating boundary effects. The highly resolved undistorted radiographs are able to visualize a sharp bubble interface even upon complex shapes, which can serve as high-quality benchmarks for numerical simulations. Here, the measured bubble shapes are compared to simulations using the incompressible boundary integral method. The direct optical access to the high-speed liquid jet provides accurate measurements of the evolution of the jet speed, which is contrasted to the simulated results. After the jet has impacted the opposite side of the cavitation bubble, the cavity assumes a toroidal shape, the volume of which can be accurately measured from the radiographs and its temporal evolution compared to the bubble-ring model. Thanks to the clear optical access to the cavity lobes throughout the collapse, non-axisymmetric splashing within the bubble resulting from the jet impact, also known as Blake's splashing, is observed and characterized for stand-off parameters of γ < 1. Measurements extracted from the highly resolved visualizations provided herein have been validated against scaling laws for droplet impact on a thin liquid film, which contribute to confirm and elucidate the splashing phenomenon., Physics of Fluids, 35 (1), ISSN:1070-6631, ISSN:1089-7666, ISSN:0031-9171

WEAVE, the new wide-field, massively multiplexed spectroscopic survey facility for the William Herschel Telescope, will see first light in late 2022. WEAVE comprises a new 2-degree field-of-view prime-focus corrector system, a nearly 1000-multiplex fibre positioner, 20 individually deployable 'mini' integral field units (IFUs), and a single large IFU. These fibre systems feed a dual-beam spectrograph covering the wavelength range 366$-$959\,nm at $R\sim5000$, or two shorter ranges at $R\sim20\,000$. After summarising the design and implementation of WEAVE and its data systems, we present the organisation, science drivers and design of a five- to seven-year programme of eight individual surveys to: (i) study our Galaxy's origins by completing Gaia's phase-space information, providing metallicities to its limiting magnitude for $\sim$3 million stars and detailed abundances for $\sim1.5$ million brighter field and open-cluster stars; (ii) survey $\sim0.4$ million Galactic-plane OBA stars, young stellar objects and nearby gas to understand the evolution of young stars and their environments; (iii) perform an extensive spectral survey of white dwarfs; (iv) survey $\sim400$ neutral-hydrogen-selected galaxies with the IFUs; (v) study properties and kinematics of stellar populations and ionised gas in $z1$ million spectra of LOFAR-selected radio sources; (viii) trace structures using intergalactic/circumgalactic gas at $z>2$. Finally, we describe the WEAVE Operational Rehearsals using the WEAVE Simulator., 41 pages, 27 figures, accepted for publication by MNRAS

International audience; The database presented in this study has been acquired during the SOuth west FOGs 3D (SOFOG3D) experiment for processes study. This international campaign led by Météo-France during the winter 2019-2020 aimed at deploying a unique network of both in situ and remote sensing measurements in order to document spatial and temporal variabilities of fog events. To support this scientific objective but also to conduct first data assimilation experiments within the French convective scale model AROME, an unprecedented network of 8 ground-based microwave radiometers (MWR) has been deployed in 7 different locations known to be prone to fog occurrences. The database gives access to vertical profiles of temperature and humidity (both absolute and relative) from the surface up to 10 km altitude as well as integrated water vapor and liquid water path estimates. The retrieved profiles offer a very large database that can be exploited for several scientific purposes: fog process studies at specific location, documentation on the variability of fog properties at the regional scale, better understanding of the atmospheric boundary layer (ABL) height and dynamics during wintertime conditions, development of nowcasting products dedicated to fog alerts, data assimilation experiments to improve fog forecasts, development of synergetical advanced products, and evaluation of new model configurations with advanced parameterization or resolutions. Keywords Microwave radiometer • Brightness temperatures • Fog • Temperature • Humidity • Liquid water path • Integrated water vapor All the authors contributed to the instrumental deployment of microwave radiometers. Pauline Martinet and Vinciane Unger conducted the scientific evaluation, data preparation, and the data delivery on the AERIS portal.

Switch-reference has been analyzed as a reference tracking mechanism, whose main function is to avoid ambiguity of reference. One domain where this function has been argued to manifest itself is referential choice. Kibrik (Kibrik, Andrej. 2011. Reference in discourse. Oxford: Oxford University Press) notably proposed that switch-reference marking plays the role of a referential aid, which helps to prevent referential conflict, thereby enabling the production of reduced referential expressions such as pronouns and zeros. The present study probes this theory through an analysis of the role of switch-reference marking in multifactorial models of referential choice in Mbyá Guaraní. We show that while switch-reference increases the likelihood of mention reduction in Mbyá Guaraní, this effect is marginal relative to other predictors of referential choice. We argue that this result is compatible with the analysis of switch-reference as a referential aid, but also supports analyses that emphasize the multiplicity of its functions, beyond the disambiguation of reference.

Brazilian Portuguese has received much attention in the typology of noun phrases for being a language with a fully-fledged determiner system that also allows generalized bare singular nominals. This paper investigates the use of bare singulars in relative measure constructions, such as um terço de mulher (literally, ‘one third of woman’). We show that Ahn & Sauerland’s (2015, 2017) and Pasternak & Sauerland’s (2020) analysis of relative measure constructions, combined with existing theories of bare singulars, predicts that bare singulars should be attested in relative measure constructions and derives their range of attested interpretations in these constructions. At the same time, we argue that these combined analyses predict that bare singulars should be attested in relative measure constructions in other Romance languages. This prediction is problematic and highlights the need for further research on the interaction of bare singulars and relative measures.

Cavitation has been extensively studied in Newtonian fluids and to a lesser yet significant degree in shear-thinning fluids. However, cavitation has not been previously investigated in shear-thickening fluids, of which a water-cornstarch suspension is perhaps the best-known example. An interesting property of such fluids is that, when subjected to an increase in strain rate, their viscosity increases until they exhibit solidlike behavior and can even fracture. As cavitation bubbles are capable of generating extreme strain rates, they could be affected by shear-thickening fluid behavior. As visual access is limited by opaque or non-index-matched particles present in such fluids, an experimental study of nominally cylindrical spark-induced cavitation bubbles is conducted in a 2 mm gap between two parallel flat and transparent plates, which allows visualization of the bubbles as they contact the boundary. They are theoretically studied through the cylindrical Keller-Miksis equation adapted to a shear-thickening fluid using a Cross model. For volume fractions starting from φ=0.44, the limit between continuous and discontinuous shear-thickening regime, cavitation bubbles deform increasingly until they are replaced by cavitation-induced fracture between φ=0.46 and φ=0.52. Fracture propagation speeds were found to be in the same range as fracture speeds previously reported for pressure-driven cavity expansion, albeit for estimated initial pressures that are now orders of magnitude higher.

In recent decades, mounting evidence has indicated that the expansion of oil palm (OP) plantations at the expense of tropical forest has had a far pernicious effect on ecosystem aspects. While various deforestation-free strategies have been proposed to enhance OP sustainability, field-based evidence still need to be consolidated, in particular with respect to savanna regions where OP expansion has recently occurred and that present large area with potential for OP cultivation. Here we show that the common management practice creating within the plantation the so-called management zones explained nearly five times more variability of soil biogeochemical properties than the savanna land-use change per se. We also found that clayey-soil savanna conversion into OP increased total ecosystem C stocks by 40 ± 13 Mg C ha(−1) during a full OP cultivation cycle, which was due to the higher OP-derived C accumulated in the biomass and in the soil as compared to the loss of savanna-derived C. In addition, application of organic residues in specific management zones enhanced the accumulation of soil organic carbon by up to 1.9 Mg ha(−1) year(−1) over the full cycle. Within plantation, zones subjected to organic amendments sustained similar soil microbial activity as in neighboring savannas. Our findings represent an empirical proof-of-concept that the conversion of non-forested land in parallel with organic matter-oriented management strategies can enhance OP agroecosystems C sink capacity while promoting microbe-mediated soil functioning. Nonetheless, savannas are unique and threatened ecosystems that support a vast biodiversity. Therefore, we suggest to give priority attention to conservation of natural savannas and direct more research toward the impacts of the conversion and subsequent management of degraded savannas., Global Change Biology, 28 (7), ISSN:1354-1013, ISSN:1365-2486

International audience

Climate warming is releasing carbon from soils around the world, constituting a positive climate feedback. Warming is also causing species to expand their ranges into new ecosystems Yet, in most ecosystems, whether range expanding species will amplify or buffer expected soil carbon loss is unknown. Here we used alpine grasslands as a model system to determine whether the establishment of herbaceous lowland plants in alpine ecosystems influences short-term soil carbon storage under warming. We found that warming (

Environmental and Social Impact Assessments or ESIA’s are one of the main project decision-making tools in use to address environmental and social externalities related to project development. They have evolved in response to the ever-growing need to better acknowledge and mitigate negative environmental and social impacts of human development that began with the so-called environmental awakening in the 1960s. This movement led to the first impact assessment tool being developed and implemented in the USA under the National Environmental Policy Act (NEPA) and is known as the Environmental Impact Assessment (EIA). The ESIA today is found in numerous national legislations, international agreements, lending institution requirements and is viewed as key to addressing the problem of sustainable development. This study will try and understand how ESIA has evolved by using hydropower development as a case study. This is particularly relevant as hydropower faces a paradox in that they are viewed as bought merely a renewable source of energy and a source of negative local or regional environmental and social impacts. Through a literature review and interviews with relevant experts in the field, this study will look at the evolution of the ESIA in hydropower to better understand what has made the ESIA what they are today, how they fit into the changing agendas and how they address the issue of sustainability in hydropower. The findings were that the evolution of the ESIA was driven by changing environmental agendas due to growing awareness of the scope of environmental and social issues. Furthermore, the interaction between different actors such as legislators/regulators, developers/investors, practitioners, academics, and civil society is what has shaped the ESIA into what it is today. Despite this long evolution, however, in practice ESIA’s have encountered some limitations due to scoping, cumulative impacts, timing of their intervention and putting them properly into practice in hydropower development projects. This has led to questions in the role of ESIAs regarding the future of sustainable hydropower development. The hydropower industry is evolving into a more integrative approach where Strategic Environmental Assessment (SEA) and Basin Management Plans (MBP’s) are being strongly advocated by key international and regional actors in hydropower such as the International Hydropower Association (IHA) and the Mekong River Commission (MRC). ESIA’s are still an integral part of hydropower development and are developing new methods of valuation to better address some limitations and to address sustainability for better cost-benefit analysis. These two organizations cited above, along with international lenders (World Bank, International Finance Corporation, EIB etc.) have over the past two decades advocated, integrating project-related ESIA’s into a larger-scale assessment that allows for better sustainability assessment of hydropower development on a national or regional scale and thus satisfy their safeguard policies that allows them to confirm or not whether they will lend money to developers or not. This is in line with the growing understanding and acknowledgment that the scope of environmental and social issues is usually beyond what a single project assessment can address. M-IES

Transformer language models have shown remarkable ability in detecting when a word is anomalous in context, but likelihood scores offer no information about the cause of the anomaly. In this work, we use Gaussian models for density estimation at intermediate layers of three language models (BERT, RoBERTa, and XLNet), and evaluate our method on BLiMP, a grammaticality judgement benchmark. In lower layers, surprisal is highly correlated to low token frequency, but this correlation diminishes in upper layers. Next, we gather datasets of morphosyntactic, semantic, and commonsense anomalies from psycholinguistic studies; we find that the best performing model RoBERTa exhibits surprisal in earlier layers when the anomaly is morphosyntactic than when it is semantic, while commonsense anomalies do not exhibit surprisal at any intermediate layer. These results suggest that language models employ separate mechanisms to detect different types of linguistic anomalies., ACL 2021 (Long Paper)

This paper presents the potential of nonlinear and linear versions of an observation operator for simulating polarimetric variables observed by weather radars. These variables, deduced from the horizontally and vertically polarized backscattered radiations, give information about the shape, the phase and the distributions of hydrometeors. Different studies in observation space are presented as a first step toward their inclusion in a variational data assimilation context, which is not treated here. Input variables are prognostic variables forecasted by the AROME-France numerical weather prediction (NWP) model at convective scale, including liquid and solid hydrometeor contents. A nonlinear observation operator, based on the T-matrix method, allows us to simulate the horizontal and the vertical reflectivities (ZHH and ZVV), the differential reflectivity ZDR, the specific differential phase KDP and the co-polar correlation coefficient ρHV. To assess the uncertainty of such simulations, perturbations have been applied to input parameters of the operator, such as dielectric constant, shape and orientation of the scatterers. Statistics of innovations, defined by the difference between simulated and observed values, are then performed. After some specific filtering procedures, shapes close to a Gaussian distribution have been found for both reflectivities and for ZDR, contrary to KDP and ρHV. A linearized version of this observation operator has been obtained by its Jacobian matrix estimated with the finite difference method. This step allows us to study the sensitivity of polarimetric variables to hydrometeor content perturbations, in the model geometry as well as in the radar one. The polarimetric variables ZHH and ZDR appear to be good candidates for hydrometeor initialization, while KDP seems to be useful only for rain contents. Due to the weak sensitivity of ρHV, its use in data assimilation is expected to be very challenging.

International audience; We reported a new strategy to enhance the sensing performances of a commercial microcantilever with optical readout in dynamic mode for the vapor detection of organophosphorus compounds (OPs). In order to increase significantly the surface area accessible to the molecules in the vapor phase, we nanostructured both sides of the microcantilever with ordered, open and vertically oriented amorphous titanium dioxide nanotubes (TiO2-NTs) in one step by an anodization method. However, due to the aggressive conditions of anodization synthesis it remains a real challenge to nanostructure both sides of the microcantilever. Consequently, we developed and optimized a protocol of synthesis to overcome these harsh conditions which can lead to the total destruction of the silicon microcantilever. Moreover, this protocol was also elaborated in order to maintain a good reflection of the laser beam on one side of the microcantilever towards the position sensitive photodiode and limit the light diffusion by the NTs film. The results related to the detection of dimethyl methylphosphonate (DMMP) showed that TiO2 and the nanostructuring on both sides of the microcantilever with NTs indeed improved the response of the sensor to vapors compared to a microcantilever nanostructured on only one side. The dimensions and morphology of NTs guaranteed the access of molecules to the surface of NTs. This approach showed promising prospects to enhance the sensing performances of microcantilevers.

In Mbyá, target state resultative predicates can only be derived from inchoative verbs. This is in contrast with target state adjectival passives in better studied languages such as English, German and Greek, which can be derived from transitive causatives. I argue that the limited distribution of Mbyá resultatives reveals a point of variation in the association between roots and external-argument introducing Voice heads: while roots of non-agentive transitive causatives need not be lexically associated to agent or causer Voice in English and similar languages, they do in Mbyá. Together with the well documented incompatibility of target state resultatives with agent/causer Voice, this difference explains the restricted distribution of Mbyá resultatives. The proposed analysis stresses the importance of the distinction between target states and resultant states in the structure of adjectival passives and related resultative predicates cross-linguistically.

This paper presents the potential of non-linear and linear versions of an observation operator for simulating polarimetric variables observed by weather radars. These variables, deduced from the horizontally and vertically polarised backscattered radiations, give information about the shape, the phase and the distributions of hydrometeors. Different studies in observation space are presented, as a first step toward their inclusion in a variational data assimilation context, which is not treated here. Input variables are prognostic variables forecasted by the AROME-France Numerical Weather Prediction (NWP) model at convective scale, including liquid and solid hydrometeor contents. A non-linear observation operator, based on the T-matrix method, allows to simulate the horizontal and the vertical reflectivities (ZHH and ZVV), the differential reflectivity ZDR, the specific differential phase KDP and the copolar correlation coefficient ρHV. To assess the uncertainty of such simulations, perturbations have been applied on input parameters of the operator, such as dielectric constant, shape and orientation of the scatterers. Statistics of innovations, defined by the difference between simulated and observed values, are then performed. After some specific filtering procedures, shapes close to Gaussian have been found for both reflectivities and for ZDR, contrarily to KDP and ρHV. A linearised version of this observation operator has been obtained by its Jacobian matrix estimated with the finite difference method. This step allows to study the sensitivity of polarimetric variables to hydrometeor content perturbations, in the model geometry as well as in the radar one. The polarimetric variables ZHH and ZDR appear to be good candidates for hydrometeor initialisation, while KDP seems to be useful only for rain contents. Due to the weak sensitivity of ρHV, its use in data assimilation is expected to be very challenging.

Productivity from day one on supercomputers that leverage new technologies requires significant preparation. An institution that procures a novel system architecture often lacks sufficient institutional knowledge and skills to prepare for it. Thus, the "Center of Excellence" (CoE) concept has emerged to prepare for systems such as Summit and Sierra, currently the top two systems in the Top 500. This paper documents CoE experiences that prepared a workload of diverse applications and math libraries for a heterogeneous system. We describe our approach to this preparation, including our management and execution strategies, and detail our experiences with and reasons for using different programming approaches. Our early science and performance results show that the project enabled significant early seismic science with up to a l4X throughput increase over Cori. In addition to our successes, we discuss our challenges and failures so others may benefit from our experience.

Alternatives to ecologically devastating deforestation land use change trajectories are needed to reduce the carbon footprint of oil palm (OP) plantations in the tropics. Although various land use change options have been proposed, so far, there are no empirical data on their long-term ecosystem carbon pools effects. Our results demonstrate that pasture-to-OP conversion in savanna regions does not change ecosystem carbon storage, after 56 years in Colombia. Compared to rainforest conversion, this alternative land use change reduces net ecosystem carbon losses by 99.7 ± 9.6%. Soil organic carbon (SOC) decreased until 36 years after conversion, due to a fast decomposition of pasture-derived carbon, counterbalancing the carbon gains in OP biomass. The recovery of topsoil carbon content, suggests that SOC stocks might partly recover during a third plantation cycle. Hence, greater OP sustainability can be achieved if its expansion is oriented toward pasture land., Science Advances, 5 (11), ISSN:2375-2548

Cet article vise à entreprendre un état des lieux de l’enseignement en anglais dans les facultés de droit en France en partant de l’exemple des cours dispensés en Licence dans les universités de Rennes 1 et de Lyon 3. Après avoir évoqué les principaux enjeux de l’élaboration de cours d’anglais destinés à de futurs juristes, notamment la place à accorder au contenu disciplinaire, les auteurs présentent les programmes et les modalités d’enseignement dans les deux facultés comparées. Les similitudes observées témoignent d’une conscience croissante de la nécessité d’adapter l’enseignement de la langue aux communautés professionnelles dans lesquelles les étudiants seront amenés à évoluer, conformément à ce que préconisent les spécialistes de l’anglais de spécialité. Cet article montre également que les modalités d’enseignement varient sensiblement d'une faculté à l'autre, ce que les auteurs attribuent au fait que les choix pédagogiques sont étroitement liés au contexte socio-économique propre à chaque université. This article aims to provide a first step towards an overview of English teaching practices in French law faculties, through the comparison of how classes are taught in the universities of Rennes 1 and Lyon 3. After discussing the main issues of English courses for law students, such as the place to be given to the specific disciplinary content, the authors present the syllabi and teaching methods used in the two universities of reference. The similarities observed are a sign of the growing awareness that language teaching ought to be adapted to the professional community in which students will eventually work, in accordance with what most specialists of English for specific purposes advocate. This article also demonstrates that teaching practices vary conspicuously from one university to another, which the authors attribute to the fact that pedagogical choices are closely linked to each university’s own socio-economic context.