pinecone/core-2020-05-10-deduplication huggingface dataset:
beta-arrestin 2 oligomerization controls the Mdm2-dependent inhibition of p53.

International audiencebeta-arrestins (beta-arrs), two ubiquitous proteins involved in serpentine heptahelical receptor regulation and signaling, form constitutive homo- and heterooligomers stabilized by inositol 1,2,3,4,5,6-hexakisphosphate (IP6). Monomeric beta-arrs are believed to interact with receptors after agonist activation, and therefore, beta-arr oligomers have been proposed to represent a resting biologically inactive state. In contrast to this, we report here that the interaction with and subsequent titration out of the nucleus of the protooncogene Mdm2 specifically require beta-arr2 oligomers together with the previously characterized nucleocytoplasmic shuttling of beta-arr2. Mutation of the IP6-binding sites impair oligomerization, reduce interaction with Mdm2, and inhibit p53-dependent antiproliferative effects of beta-arr2, whereas the competence for receptor regulation and signaling is maintained. These observations suggest that the intracellular concentration of beta-arr2 oligomers might control cell survival and proliferation
CD4+CD25+ regulatory T cells inhibit natural killer cell functions in a transforming growth factor-beta-dependent manner.

Tumor growth promotes the expansion of CD4+CD25+ regulatory T (T reg) cells that counteract T cell-mediated immune responses. An inverse correlation between natural killer (NK) cell activation and T reg cell expansion in tumor-bearing patients, shown here, prompted us to address the role of T reg cells in controlling innate antitumor immunity. Our experiments indicate that human T reg cells expressed membrane-bound transforming growth factor (TGF)-beta, which directly inhibited NK cell effector functions and down-regulated NKG2D receptors on the NK cell surface. Adoptive transfer of wild-type T reg cells but not TGF-beta-/- T reg cells into nude mice suppressed NK cell-mediated cytotoxicity, reduced NKG2D receptor expression, and accelerated the growth of tumors that are normally controlled by NK cells. Conversely, the depletion of mouse T reg cells exacerbated NK cell proliferation and cytotoxicity in vivo. Human NK cell-mediated tumor recognition could also be restored by depletion of T reg cells from tumor-infiltrating lymphocytes. These findings support a role for T reg cells in blunting the NK cell arm of the innate immune system
Tracking selenium in the Chalk aquifer of northern France: Sr isotope constraints

International audienceGroundwater at the southern and eastern edges of France's Paris Basin has a selenium content that at times exceeds the European Framework Directive's drinking-water limit value of 10 µg/L. To better understand the dynamics of the Chalk groundwater being tapped to supply the city of Lille and the Se origins, we used a combination of geochemical and isotopic tools. Strontium isotopes, coupled with Ca/Sr, Mg/Sr and Se/Sr ratios, were used to identify the main groundwater bodies and their mixings, with the Mg/Sr ratio constraining a ternary system. Groundwater in the agricultural aquifer-recharge zone represents a first end-member and displays the youngest water ages of the catchment along with the highest strontium isotopic signature (0.7084) and low Se contents. Anaerobic groundwater constitutes a second major end-member affected by water-rock interactions over a long residence time, with the lowest strontium isotopic signature (0.7079) and the lowest Se content, its low SF6 content confirming the contribution of old water. Se-rich groundwater containing up to 30 µg/L of Se represents a third major end-member, with an intermediate Sr isotopic ratio, and is mainly constrained by the clayey Se-rich formation overlying the Chalk aquifer. The spatial and temporal Se variability in the groundwater is clearly linked to the presence of this formation identified as Tertiary and also to the hydrological conditions; saturation of the Se-rich clays by oxygenated groundwater enhances Se mobility and also Sr adsorption onto the clays. This multi-tool study including Sr isotopes successfully identified the Se origins in the aquifer and has led to a better understanding of the regional mixing and processes affecting the Chalk groundwater
Can Uncertainty Justify Overlapping Policy Instruments to Mitigate Emissions?

International audienceThis article constitutes a new contribution to the analysis of overlapping instruments to cover the same emission sources. Using both an analytical and a numerical model, we find that if there is a risk that the carbon price drops to zero and if the political unavailability of a CO2 tax (at least in the European Union) is taken into account, it can be socially beneficial to implement an additional instrument encouraging the reduction of emissions, for instance a renewable energy subsidy. Our analysis has both a practical and a theoretical purpose. It aims at giving economic insight to policymakers in a context of increased uncertainty concerning the future stringency of the European Emission Trading Scheme. It also gives another rationale for the use of several instruments to cover the same emission sources, and shows the importance of accounting for corner solutions in the definition of the optimal policy mix
Physiological and biochemical response to photooxidative stress of the fundamental citrus species

International audienceDespite the economic importance of citrus, insights on the genetic response to stress are scarce. The aim of the present study was to compare fundamental citrus species for their response to photooxidative stress. The experiment was conducted under orchard conditions on three fundamental citrus species C. medica L., C. reticulata Blanco and C. maxima (Burm.) Merr., and on Fortunella japonica (Thunb.) Swing. We examined their respective net photosynthesis (Pnet), stomatal conductance (Gs) and chlorophyll fluorescence (Fv/Fm) on sun-acclimated leaves and shade-acclimated leaves returned under natural sunlight irradiance. To compare the respective response mechanism, we analyzed changes in oxidative status (hydrogen peroxide (H2O2) and malondialdehyde (MDA)), reactive oxygen species (ROS)-scavenging enzymes (superoxide dismutase (SOD), catalase, ascorbate peroxidase), recycling enzymes (monodehydroascorbate reductase, dehydroascorbate reductase and glutathione reductase) and antioxidant metabolites (ascorbate and glutathione). Kumquat and pummelo exposed lower down-regulation and full recovery of photosynthetic parameters, lower accumulation of oxidized compounds associated with greater production of reduced glutathione (Gsh) and enhanced activity of the three ROS scavenging enzymes, especially SOD. Citron and mandarin showed a marked decrease and incomplete recovery in photosynthetic performance, mainly in Pnet and Fv/Fm, larger accumulation of oxidative parameters, slighter induction of antioxidant enzymes and down-regulation of reduced ascorbate (Asa) and Gsh synthesis. These results suggest that kumquat and pummelo have a greater tolerance to photooxidative stress than citron and mandarin
Melilite-bearing lavas in Mayotte (France): An insight into the mantle source below the Comores

International audienceOcean island basalts (OIB) from the Comores archipelago (Indian Ocean) display mineralogical and geochemical features different from the other Indian OIB. We present here new geochronological data (40Ar/39Ar), major and trace element compositions and isotopic (Sr, Nd, Pb) ratios of silica-undersaturated alkaline rocks from Mayotte, the oldest island of the Comores. Two trends are defined using major element composition: (1) a highly silica-undersaturated trend which includes basanites, (melilite-bearing) nephelinites, intermediate lavas and phonolites from the southern part of the island and (2) a moderately silica-undersaturated trend which is mainly represented by alkali basalts, basanites, intermediate lavas and phonolites from the northern part of the island. Both trends could be explained, to some extent, by variable degrees of partial melting. Normative larnite-bearing olivine melilitites and nephelinites exhibit, in addition to their high silica-undersaturation, elevated concentrations in CaO (>12wt.%) and P2O5 (up to 1.35wt.%). These exceptional rocks would result from low degree deep partial melting of a CO2-metasomatized source in the presence of carbonate (probably dolomite) and apatite. Igneous rocks from southern and northwestern shield volcanoes are characterized by a radiogenic Pb composition, revealing the existence of a HIMU (high μ=238U/204Pb) component in their source. Its influence decreases from the main building stage (>10.6-~3.0Ma) to the post-shield stage for the benefit of a depleted MORB-mantle (DMM) component, especially in the north central rocks. This feature would reflect increasing melting degrees of the depleted dominant source, bearing small-scale HIMU heterogeneities progressively consumed with time. The HIMU signature might have been introduced in the Comorian lithospheric mantle by thermal erosion or delamination of a continental lithosphere during the Gondwana break-up. The other islands of the Comores archipelago (Moheli, Anjouan and "La Grille" type lavas from Grande Comore) display also a DMM-HIMU mixing trend. Only a few lavas from Grande Comore ("Karthala" type) and one sample from Mayotte show the clear EM1 contribution (87Sr/86Sr>0.7035) of the Comorian plume
Oxidation kinetics and mechanisms of Ni-base alloys in pressurised water reactor primary conditions: Influence of subsurface defects

International audienceOxidation of Alloy 690 in PWR primary water conditions has been investigated, considering particularly the role played by subsurface structural defects. To simulate a defective surface state, Xe implantation has been set up on samples. Corrosion experiments were thereafter performed in a corrosion loop simulating the PWR medium with durations between 24 h and 1000 h. Microstructural observations and NRA measurements underlined the role played by defects on the crystallinity of the continuous oxide spinel layer, on the nucleation of Cr2O3 nodules and on the oxidation rate. The higher defects concentration seemed to modify the oxygen diffusion in the oxide scale
Photoactivated surface grafting from PVDF surfaces

International audienceEconomic and easy methods to tune surface properties of polymers as Poly(vinylidene fluoride) (PVDF) without altering bulk properties are of major interest for different applications as biotechnological devices, medical implant device. . . UV irradiation appears as one of the simplest, easy and safe method to modify surface properties. In the case of self-initiated grafting, it is generally assumed that the pretreatment of the PVDF surface with UV irradiation can yield alkyl and per-oxy radicals originating from breaking bonds and capable of initiating the subsequent surface grafting polymerizations. Surprisingly, the present work shows that it is possible to obtain polymer grafting using low energetic UV-A irradiation (3.1-3.9 eV) without breaking PVDF bonds. An EPR study has been performed in order to investigate the nature of involved species. The ability of the activated PVDF surface to graft different kinds of hydrophilic monomers using the initiated surface polymerization method has been tested and discussed on the basis of ATR FT-IR, XPS and NMR HRMAS results
In situ temperature measurements through i-anvils in diamond anvil cells.

International audienceThis study is devoted to in situ temperature measurement in diamond anvil cells (DAC) with implanted anvils (i-anvils). I-anvils consist of diamonds implanted with B and/or C ions, situated below the diamond's surface at a depth of 1-3 µm; forming sensors which are placed below the culet at the location of the DAC's sample chamber. I-anvils can be employed as temperature or pressure sensors, exploiting their electrical properties. We have tested the sensor's behaviour with temperatures up to 900°C, at ambient pressure and up to 6 GPa in real experimental conditions in two types of DAC. For this purpose, we performed experiments in four different i-anvils at temperatures up to 900°C. We have compared the signal measured by the sensors with the temperature measured by a thermocouple attached to the i-anvil. The temperature gradient between the sample chamber and the thermocouple position was taken into account by phase transition measurements of calibration standards. Reproducible laws of current variation with temperature have been established. We conclude that i-anvils are reliable and sensitive to measure the temperature in situ in diamond anvil cells with an accuracy of better than 1°C
Effect of Sm-, Gd- codoping on structural modifications in aluminoborosilicate glasses under beta-irradiation.

International audienceTwo series of Sm-, Gd-codoped aluminoborosilicate glasses with different total rare earth content have been studied in order to examine the codoping effect on the structural modifications of beta-irradiated glasses. The data obtained by Electron Paramagnetic Resonance spectroscopy indicated that relative amount of Gd3+ ions located in network former position reveals non-linear dependence on Sm/Gd ratio. Besides, codoping leads to the evolution of the EPR signal attributed to defects created by irradiation: superhyperfine structure of boron oxygen hole centres EPR line becomes less noticeable and resolved with increase of Gd amount. This fact manifests that Gd3+ ions are mainly diluted in vicinity of the boron network. By Raman spectroscopy, we showed that the structural changes induced by the irradiation also reveal non-linear behaviour with Sm/Gd ratio. In fact, the shift of the Si-O-Si bending vibration modes has a clear minimum for the samples containing equal amount of Sm and Gd (50:50) in both series of the investigated glasses. In contrast, for single doped glass there is no influence of dopant's content on Si-O-Si shift (in case of Gd) or its diminution (in case of Sm) occurs which is explained by the reduction process influence. At the same time, no noticeable effect of codoping on Sm3+ intensity as well as on Sm2+ emission or on Sm reduction process was observed
A photo-detector for UHECR observation from space

International audienceIt is most likely that the next generation of experiments for the study of the Ultra High-Energy Cosmic Radiation (UHECR), that is cosmic particles reaching the Earth with energies in excess of 10$^{19}$ eV, will consist of space-based experiments. The observation from space of the Extensive Atmospheric Showers (EAS) produced by UHECR is a big challenge, because the faint signal must be extracted from a large background by an experimental apparatus operating in space. The requirements for the photo-detector for such a kind of space missions will be briefly discussed and the solutions adopted for the design of the photo-detector of the EUSO experiment will be presented
A two-phase two-layer model for fluidized granular flows with dilatancy effects

International audienceWe propose a two-phase two-thin-layer model for fluidized debris flows that takes into account dilatancy effects, based on the closure relation proposed by Roux and Radjai (1998). This relation implies that the occurrence of dilation or contraction of the granular material depends on whether the solid volume fraction is respectively higher or lower than a critical value. When dilation occurs, the fluid is sucked into the granular material, the pore pressure decreases and the friction force on the granular phase increases. On the contrary, in the case of contraction, the fluid is expelled from the mixture, the pore pressure increases and the friction force diminishes. To account for this transfer of fluid into and out of the mixture, a two-layer model is proposed with a fluid layer on top of the two-phase mixture layer. Mass and momentum conservation are satisfied for the two phases, and mass and momentum are transferred between the two layers. A thin-layer approximation is used to derive average equations, with accurate asymptotic expansions. Special attention is paid to the drag friction terms that are responsible for the transfer of momentum between the two phases and for the appearance of an excess pore pressure with respect to the hydrostatic pressure. For an appropriate form of dilatancy law we obtain a depth-averaged model with a dissipative energy balance in accordance with the corresponding 3D initial system
Tantalum superconducting tunnel junctions for infrared photon counting

International audienceSuperconducting Tunnel Junctions (STJ) are currently being developed as photon detectors for a wide range of applications. Interest comes from their ability to cumulate photon counting with chromaticity (i.e. energy resolution) from the Near InfraRed (NIR) to the X-rays wavelengths and excellent quantum efficiency up to 80%. Resolving power can reach more than 10 in the visible. Our main goal is to use STJ for astronomical observation at low light level in the near infrared. This paper relates mainly to two points: The improvement of the Tantalum absorber epitaxy and the development of a new version of the fabrication process for making Ta/Al-AlOx-Al/Ta photon counting STJ. The main features of this process are that pixels have aligned electrodes and vias patterned through a protecting SiO2 layer. This vias are then used to contact the top electrode layer. We use a double thin aluminum trapping layer on top of a 150nm thick Ta absorber grown epitaxially
Soil Drainage as an Active Agent of Recent Soil Evolution

International audienceWhile research on pedogenesis mainly focuses on long-term soil formation and most often neglects recent soil evolution in response to human practices or climate changes, this article reviews the impact of artificial subsurface drainage on soil evolution. Artificial drainage is considered as an example of the impact of recent changes in water fluxes on soil evolution over time scales of decades to a century. Results from various classical studies on artificial drainage including hydrological and environmental studies are reviewed and collated with rare studies dealing explicitly with soil morphology changes, in response to artificial drainage. We deduce that soil should react to the perturbations associated with subsurface drainage over time scales that do not exceeding a few decades. Subsurface drainage decreases the intensity of erosion and must i) increase the intensity of the lixiviation and eluviation processes, ii) affect iron and manganese dynamics, and iii) induce heterogeneities in soil evolution at the ten meter scale. Such recent soil evolutions can no longer be neglected as they are mostly irreversible and will probably have unknown, but expectable, feedbacks on crucial soil functions such as the sequestration of soil organic matter or the water available capacity
Ground-based measurements of the solar diameter during the rising phase of solar cycle 24

International audienceFor the past thirty years, modern ground-based time-series of the solar radius have shown different apparent variations according to different instruments. The origins of these variations may result from the observer, the instrument, the atmosphere, or the Sun. Solar radius measurements have been made for a very long time and in different ways. Yet we see inconsistencies in the measurements. Numerous studies of solar radius variation appear in the literature, but with conflicting results. These measurement differences are certainly related to instrumental effects or atmospheric effects. Use of different methods (determination of the solar radius), instruments, and effects of Earth's atmosphere could explain the lack of consistency on the past measurements. A survey of the solar radius has been initiated in 1975 by Francis Laclare, at the Calern site of the Observatoire de la Côte d'Azur (OCA). Several efforts are currently made from space missions to obtain accurate solar astrometric measurements, for example, to probe the long-term variations of solar radius, their link with solar irradiance variations, and their influence on the Earth climate. Aims. The Picard program includes a ground-based observatory consisting of different instruments based at the Calern site (OCA, France). This set of instruments has been named "Picard Sol" and consists of a Ritchey-Chrétien telescope providing full-disk images of the Sun in five narrow-wavelength bandpasses (centered on 393.37, 535.7, 607.1, 782.2, and 1025.0 nm), a Sun-photometer that measures the properties of atmospheric aerosol, a pyranometer for estimating a global sky-quality index, a wide-field camera that detects the location of clouds, and a generalized daytime seeing monitor allowing us to measure the spatio-temporal parameters of the local turbulence. Picard Sol is meant to perpetuate valuable historical series of the solar radius and to initiate new time-series, in particular during solar cycle 24. Methods. We defined the solar radius by the inflection-point position of the solar-limb profiles taken at different angular positions of the image. Our results were corrected for the effects of refraction and turbulence by numerical methods. Results. From a dataset of more than 20 000 observations carried out between 2011 and 2013, we find a solar radius of 959.78 ± 0.19 arcsec (696 113 ± 138 km) at 535.7 nm after making all necessary corrections. For the other wavelengths in the solar continuum, we derive very similar results. The solar radius observed with the Solar Diameter Imager and Surface Mapper II during the period 2011-2013 shows variations shorter than 50 milli-arcsec that are out of phase with solar activity
Numerical Investigations of Polyester Coextrusion Instabilities

International audienceInterfacial instabilities occurring in the coextrusion process of molten polymers have been widely studied. The theoretical work based on the stability of 2D Poiseuille multilayer flows (invariant along the flow motion) have pointed out the convective nature of this instability (it is either amplified or damped in the flow direction). This behaviour has been confirmed by experimental observations. As this instability is purely elastic (the Reynold number in coextrusion process is very small), it is necessary to introduce a viscoelastic constitutive equation for the polymers. Comparisons between experimental observations and theoretical approaches based on the Giesekus or White-Metzner models give good agreements for laboratory simple devices. However, the applicability of this approach for industrial coextrusion process remains an important challenge, because one has to deal with the influence of complex geometries, varying temperature and more realistic constitutive equations. As it is still very costly in computational time to perform 3D instationary computations for viscoelastic fluids, a methodology to analyse the appearance of interfacial instabilities in a complex geometry is proposed within this paper. First, a stationary 3D computation is performed in the real geometry for a single polymer. This computation allows to find zones in which the flow motion is essentially 2D, isotherm and with maximum values of the shear rate and, thus, the Weissenberg number. Instationary 2D finite element computations for two layer flows and a multi-mode differential viscoelastic model are then performed in these zones. Spatio-temporal analyses give information on the spatial behaviour of interfacial disturbances. This methodology is applied to the coextrusion of two polyesters for which experimental observations are available. The simulations predict well the experimental results and show that the outlet zone can amplify low frequencies perturbations. Finally, the influence of processing parameters (temperatures, flow rates, ...) and die geometries has been checked