pinecone/core-2020-05-10-deduplication huggingface dataset:
Effective theories for Dark Matter interactions and the neutrino portal paradigm

In this article we discuss a general effective-theory description of a multicomponent dark sector with an unspecified non-trivial symmetry and its interactions with the Standard Model generated by the exchange of heavy mediators. We then categorize the relevant effective operators given the current experimental sensistivity where the underlying theory is weakly coupled and renormalizable, with neutral mediators: either scalars or fermions. An interesting scenario resulting from this categorization is the neutrino portal, where only fermion mediators are present, and where the dark sector consists of fermions and scalars such that the lightest dark particle is a fermion, this scenario is characterized by having naturally suppressed couplings of the DM to all SM particles except the neutrinos and has received little attention in the literature. We find that there is a wide region in parameter space allowed by the current experimental constraints (relic abundance, direct and indirect detection limits); the cleanest signature of this paradigm is the presence of monochromatic neutrino lines with energy equal to that of the DM mass, but experimental sensitivity would have to be improved significantly before this can be probed
From local networks of SMEs to virtual districts?

Industrial districts as local networks of small and medium enterprises (SMEs) rooted their competitiveness in a mix of economic relationships and social ties. Recently, network technologies have promised gains of efficiency through a reduction in transaction costs and showed new commercial opportunities for small firms. Despite the morphological similarities between industrial districts and network technologies, a longitudinal analysis of ICT diffusion within Italian districts shows that the foreseen convergence between the district economic model and new technologies should not be taken for granted. The observed specific evolutionary paths concerning technology innovation in local systems also opens-up issues of economic policy
Global linear stability of the boundary-layer flow over a rotating sphere

We consider the linear global stability of the boundary-layer flow over a rotating sphere. Our results suggest that a self-excited linear global mode can exist when the sphere rotates sufficiently fast, with properties fixed by the flow at latitudes between approximately 55°–65° from the pole (depending on the rotation rate). A neutral curve for global linear instabilities is presented with critical Reynolds number consistent with existing experimentally measured values for the appearance of turbulence. The existence of an unstable linear global mode is in contrast to the literature on the rotating disk, where it is expected that nonlinearity is required to prompt the transition to turbulence. Despite both being susceptible to local absolute instabilities, we conclude that the transition mechanism for the rotating-sphere flow may be different to that for the rotating disk.Peer-reviewedPost-prin
Dynamical indicators for the prediction of bursting phenomena in
  high-dimensional systems

Drawing upon the bursting mechanism in slow-fast systems, we propose
indicators for the prediction of such rare extreme events which do not require
a priori known slow and fast coordinates. The indicators are associated with
functionals defined in terms of Optimally Time Dependent (OTD) modes. One such
functional has the form of the largest eigenvalue of the symmetric part of the
linearized dynamics reduced to these modes. In contrast to other choices of
subspaces, the proposed modes are flow invariant and therefore a projection
onto them is dynamically meaningful. We illustrate the application of these
indicators on three examples: a prototype low-dimensional model, a body forced
turbulent fluid flow, and a unidirectional model of nonlinear water waves. We
use Bayesian statistics to quantify the predictive power of the proposed
indicators
mGovernment Services and Adoption: Current Research and Future Direction

Part 5: Research in ProgressInternational audienceWith the unprecedented growth of mobile technologies, governments of both developed and developing countries have started adopting mobile services in the form of m-government. While the vendors and practitioners are heavily engaged in this transformation, the scholarly world is lagging to keep pace with the progress and to provide clear theoretical guidance for successful adoption. This paper takes a stock of scholarly publications on m-government adoption since the year 2000 and reports findings and future directions based on meta-analysis of secondary data. The articles were classified into research themes, delivery mode, theory and methods. The paper identifies the dearth of scholarly work and calls for more in-depth work to make important contribution in this area
The Zero Discounting and Maximin Optimal Paths in a Simple Model of Global Warming

International audienceFollowing Stollery (1998), we extend the Solow-- Dasgupta--Heal model to analyze the effects of global warming The rise of temperature is caused by the use of fossil resources so that the temperature level can be linked to the remaining stock of these resources. The rise of temperature affects both productivity and utility. We characterize optimal solutions for the maximin and zero-discounting cases and present closed form solutions for the case where the production and utility functions are Cobb-Douglas, and the temperature level is an exponential function of the remaining stock of resources. We show that a greater weight of temperature in intratemporal preferences or a larger intertemporal elasticity of substitution both lead to postpone resource use
Testing bibliometric indicators by their prediction of scientists promotions

International audienceWe have developed a method to obtain robust quantitative bibliometric indicators for several thousand scientists. This allows us to study the dependence of bibliometric indicators (such as number of publications, number of citations, Hirsch index...) on the age, position, etc. of CNRS scientists. Our data suggests that the normalized h index (h divided by the career length) is not constant for scientists with the same productivity but differents ages. We also compare the predictions of several bibliometric indicators on the promotions of about 600 CNRS researchers. Contrary to previous publications, our study encompasses most disciplines, and shows that no single indicator is the best predictor for all disciplines. Overall, however, the Hirsch index h provides the least bad correlations, followed by the number of papers published. It is important to realize however that even h is able to recover only half of the actual promotions. The number of citations or the mean number of citations per paper are definitely not good predictors of promotion
Evidence of trophic transfer of microcystins from the gastropod Lymnaea stagnalis to the fish Gasterosteus aculeatus.

International audienceAccording to our previous results the gastropod Lymnaea stagnalis exposed to MC-producing cyanobacteria accumulates microcystins (MCs) both as free and covalently bound forms in its tissues, therefore representing a potential risk of MC transfer through the food web. This study demonstrates in a laboratory experiment the transfer of free and bound MCs from L. stagnalis intoxicated by MC-producing Planktothrix agardhii ingestion to the fish Gasterosteus aculeatus. Fish were fed during five days with digestive glands of L. stagnalis containing various concentrations of free and bound MCs, then with toxin-free digestive glands during a 5-day depuration period. MC accumulation was measured in gastropod digestive gland and in various fish organs (liver, muscle, kidney, and gills). The impact on fish was evaluated through detoxification enzyme (glutathion-S-transferase, glutathion peroxydase and superoxyde dismutase) activities, hepatic histopathology, and modifications in gill ventilation, feeding and locomotion. G. aculeatus ingestion rate was similar with intoxicated and toxin-free diet. Fish accumulated MCs (up to 3.96 ± 0.14 μg g−1 DW) in all organs and in decreasing order in liver, muscle, kidney and gills. Hepatic histopathology was moderate. Glutathion peroxydase was activated in gills during intoxication suggesting a slight reactive oxygen species production, but without any impact on gill ventilation. Intoxication via ingestion of MC-intoxicated snails impacted fish locomotion. Intoxicated fish remained significantly less mobile than controls during the intoxication period possibly due to a lower health condition, whereas they showed a greater mobility during the depuration period that might be related to an acute foraging for food. During depuration, MC elimination was total in gills and kidney, but partial in liver and muscle. Our results assess the MC transfer from gastropods to fish and the potential risk induced by bound MCs in the food web
Climate strategy with CO2 capture from the air

International audienceimmobilize it in geological structures. Air capture differs from conventional mitigation in three key aspects. First, it removes emissions from any part of the economy with equal ease or difficulty, so its cost provides an absolute cap on the cost of mitigation. Second, it permits reduction in concentrations faster than the natural carbon cycle: the effects of irreversibility are thus partly alleviated. Third, because it is less coupled with existing energy infrastructure, air capture may offer stronger economies of scale and smaller adjustment costs than the more conventional mitigation technologies.<br /><br />We assess the ultimate physical limits on the amount of energy and land required for air capture and describe two systems that might achieve air capture at prices under 200 $/tC using current technology.<br /><br />Like geoengineering, air capture limits the cost of a worst-case climate scenario. In an optimal sequential decision framework with uncertainty, existence of air capture decreases the need for near-term precautionary abatement. The long-term abatement effect is the opposite, assuming that marginal cost of mitigation decreases with time, while marginal climate change damage increases. With air capture this implies an environmental Kuznets curve, returning towards preindustrial concentration levels of greenhouse gases.Ce texte porte sur la question de la réversibilité à long terme des émissions de CO2. Il donne un exemple de technologies de capture directe à partir de l'air, qui permet de borner le coût marginal de réduction du CO2 dans toute l'économie. Il exploré les aspects thermodynamiques de la capture du dioxyde de carbone à partir de l'air. Le modèle DIAM a été étendu pour prendre en compte ces options et examiner les conséquences sur les politiques climatiques optimales
Study of a low Mach nuclear core model for two-phase flows with phase transition I: stiffened gas law

International audienceIn this paper, we are interested in modelling the flow of the coolant (water) in a nuclear reactor core. To this end, we use a monodimensional low Mach number model coupled to the stiffened gas law. We take into account potential phase transitions by a single equation of state which describes both pure and mixture phases. In some particular cases, we give analytical steady and/or unsteady solutions which provide qualitative information about the flow. In the second part of the paper, we introduce two variants of a numerical scheme based on the method of characteristics to simulate this model. We study and verify numerically the properties of these schemes. We finally present numerical simulations of a loss of flow accident (LOFA) induced by a coolant pump trip event
Influence of the intrinsic characteristics of mortars on their biofouling by pigmented organisms: Comparison between laboratory and field-scale experiments.

International audienceBiodeterioration of mortars by the photosynthetic microorganisms is affected by their intrinsic properties such as porosity, roughness and surface pH. The influence of these parameters was examined using an accelerated fouling test in laboratory and a natural fouling test in the real-world ( <i>in situ</i>). Based on color measurement and image analysis, the impact of each intrinsic parameter was evaluated. The results differed from a scale to the other one. No influence of porosity was measured on the algal colonization rate in the laboratory test whereas, a high porosity seemed to increase slightly the bioreceptivity of the mortars exposed outdoor. The roughness, in both tests, promoted the microbial colonization. However, the discrimination of roughness grades was better in the laboratory test than in the <i>in situ</i> one. The surface pH influenced remarkably on the accelerated biofouling test but not on the <i>in situ</i> one. These dissimilarities resulted from the differences in experimental configurations of the two tests
Kinematic structure of massive star-forming regions. I. Accretion along filaments

International audienceContext. The mid- and far-infrared view on high-mass star formation, in          particular with the results from the Herschel space observatory, has shed          light on many aspects of massive star formation. However, these continuum studies lack          kinematic information.Aims. We study the kinematics of the molecular gas in high-mass          star-forming regions.Methods. We complemented the PACS and SPIRE far-infrared data of 16          high-mass star-forming regions from the Herschel key project EPoS with            N2H+ molecular line data from the MOPRA and Nobeyama 45 m          telescope. Using the full N2H+ hyperfine structure, we produced column density,          velocity, and linewidth maps. These were correlated with PACS 70 μm images and PACS point          sources. In addition, we searched for velocity gradients. Results. For several regions, the data suggest that the linewidth on the          scale of clumps is dominated by outflows or unresolved velocity gradients. IRDC 18454 and          G11.11 show two velocity components along several lines of sight. We find that all regions          with a diameter larger than 1 pc show either velocity gradients or fragment into          independent structures with distinct velocities. The velocity profiles of three regions          with a smooth gradient are consistent with gas flows along the filament, suggesting          accretion flows onto the densest regions.Conclusions. We show that the kinematics of several regions have a          significant and complex velocity structure. For three filaments, we suggest that gas flows          toward the more massive clumps are present
Efficiency of source control systems for reducing runoff pollutant loads: Feedback on experimental catchments within Paris conurbation.

International audience: Three catchments, equipped with sustainable urban drainage systems (SUDS: vegetated roof, underground pipeline or tank, swale, grassed detention pond) for peak flow mitigation, have been compared to a reference catchment drained by a conventional separate sewer system in terms of hydraulic behaviour and discharged contaminant fluxes (organic matter, organic micropollutants, metals). A runoff and contaminant emission model has been developed in order to overcome land use differences. It has been demonstrated that the presence of peak flow control systems induces flow attenuation even for frequent rain events and reduces water discharges at a rate of about 50% depending on the site characteristics. This research has also demonstrated that this type of SUDS contributes to a significant reduction of runoff pollutant discharges, by 20%-80%. This level of reduction varies depending on the considered contaminant and on the design of the drainage system but is mostly correlated with the decrease in runoff volume. It could be improved if the design of these SUDS focused not only on the control of exceptional events but also targeted more explicitly the interception of frequent rain events
The role of compaction contrasts in sediments in décollement initiation in an accretionary prism

International audienceTo understand how décollements develop into the pristine sedimentary succession entering subduction zones, we have performed mechanical tests on samples from the sediment column entering the Nankai accretionary prism, Japan (ODP site 1173). Both poroelastic compliance and plastic shrinkage upon application of a large effective pressure sharply decrease with depth in a ~ 100 m-thick domain in the upper section of the Lower Shikoku Basin unit, i.e. in a domain stratigraphically close to the actual location of the décollement near the toe of the prism. These property contrasts provide a potential explanation for the outward migration of the décollement into the incoming sediments. When approaching the deformation front, a given material particle is affected by an increase in stress, which has a component of vertical loading due to the deposition of overburden trench sediment, and also a component of lateral compression transmitted from the accretionary wedge. Depending on its initial mechanical state, the amount of lateral shortening in the incoming Nankai sediment column varies with depth and causes horizontal velocity gradients that concentrate into the mechanical transition zone (upper section of the Lower Shikoku Basin at appx. 450-550 m depth) into which the décollement eventually propagates. Future work has to assess the role of this plastic deformation relative to other governing factors such as friction coefficient and excess pore pressure, both at Nankai and along other active margins
Virgo status and commissioning results

International audienceVirgo is a French–Italian collaboration for the construction and operation of a 3 km long interferometric gravitational wave antenna. The construction of the detector is already completed and the commissioning is quite advanced, while the data taking is expected to start in 2005. In this paper, we report on the present status of Virgo and on the results of commissioning activity. In particular, we analyse the first four engineering runs (C1–C4) and discuss the sensitivity obtained in C4
Collision of almost parallel vortex filaments

International audienceWe investigate the occurrence of collisions in the evolution of vortex filaments through a system introduced by Klein, Majda and Damodaran [KMD95] and Zakharov [Z88, Z99]. We first establish rigorously the existence of a pair of almost parallel vortex filaments, with opposite circulation, colliding at some point in finite time. The collision mechanism is based on the one of the self-similar solutions of the model, described in [BFM14]. In the second part of this paper we extend this construction to the case of an arbitrary number of filaments, with poly-gonial symmetry, that are perturbations of a configuration of parallel vortex filaments forming a polygon, with or without its center, rotating with constant angular velocity
Socio-economic and Climate Change Impacts on Agriculture: An Integrated Assessment

A comprehensive assessment of the impacts of climate change on agro- ecosystems over this century is developed, up to 2080 and at a global level,  albeit with significant regional detail. To this end an integrated ecological- economic modelling framework is employed, encompassing climate scenarios, agro-ecological zoning information, socio-economic drivers, as well as world  food trade dynamics. Specifically, global simulations are performed using the  FAO/IIASA agro-ecological zone model, in conjunction with IIASAs global food  system model, using climate variables from five different general circulation  models, under four different socio-economic scenarios from the  intergovernmental panel on climate change. First, impacts of different  scenarios of climate change on bio-physical soil and crop growth determinants of yield are evaluated on a 5?W5? latitude/longitude global grid; second, the  extent of potential agricultural land and related potential crop production is computed. The detailed bio-physical results are then fed into an economic  analysis, to assess how climate impacts may interact with alternative  development pathways, and key trends expected over this century for food  demand and production, and trade, as well as key composite indices such as risk of hunger and malnutrition, are computed. This modelling approach  connects the relevant bio-physical and socio-economic variables within a  unified and coherent framework to produce a global assessment of food production and security under climate change. The results from the study  suggest that critical impact asymmetries due to both climate and socio- economic structures may deepen current production and consumption gaps  between developed and developing world; it is suggested that adaptation of  agricultural techniques will be central to limit potential damages under climate change
Stiffness Analysis of Overconstrained Parallel Manipulators

International audienceThe paper presents a new stiffness modeling method for overconstrained parallel manipulators with flexible links and compliant actuating joints. It is based on a multidimensional lumped-parameter model that replaces the link flexibility by localized 6-dof virtual springs that describe both translational/rotational compliance and the coupling between them. In contrast to other works, the method involves a FEA-based link stiffness evaluation and employs a new solution strategy of the kinetostatic equations for the unloaded manipulator configuration, which allows computing the stiffness matrix for the overconstrained architectures, including singular manipulator postures. The advantages of the developed technique are confirmed by application examples, which deal with comparative stiffness analysis of two translational parallel manipulators of 3-PUU and 3-PRPaR architectures. Accuracy of the proposed approach was evaluated for a case study, which focuses on stiffness analysis of Orthoglide parallel manipulator
The role of atmospheric deposition in the biogeochemistry of the Mediterranean Sea

Estimates of atmospheric inputs to the Mediterranean (MED) and some coastal areas are reviewed, and uncertainities in these estimates considered. Both the magnitude and the mineralogical composition of atmospheric dust inputs indicate that eolian deposition is an important (50%) or prevailing (>80%) contribution to sediments in the offshore waters of the entire Mediterranean (MED) basin. Model data for trace metals and nutrients indicate that the atmosphere delivers more than half the lead and nitrogen, one-third of total phosphorus, and 10% of the zinc entering the entire basin. Measured data in sub-basins, such as the north-western MED and northern Adriatic indicate an even greater proportion of atmospheric versus riverine inputs. When dissolved fluxes are compared (the form most likely to impinge on surface water biogeochemical cycles), the atmosphere is found to be 5 to 50 times more important than rivers for dissolved Zn and 15 to 30 times more important for Pb fluxes. Neglecting co-limitation by other nutrients, new production supported by atmospheric nitrogen deposition ranges from 2-4 g C m-2 yr-1, whereas atmospheric phosphorus deposition appears to support less than 1 g C m-2 yr-1. In spite of the apparently small contribution of atmospheric deposition to overall production in the basin it has been suggested that certain episodes of phytoplankton blooms are triggered by atmospheric deposition of N, P or Fe. Future studies are needed to clarify the extent and causal links between these episodic blooms and atmospheric/oceanographic forcing functions. A scientific program aimed at elucidating the possible biogeochemical effects of Saharan outbreaks in the MED through direct sampling of the ocean and atmosphere before and after such events is therefore highly recommended