pinecone/core-2020-05-10-deduplication huggingface dataset:
Impact of climate and land cover changes on snow cover in a small Pyrenean catchment

International audienceThe seasonal snow in the Pyrenees Mountains is an essential source of runoff for hydropower production and crop irrigation in Spain and France. The Pyrenees are expected to undergo strong environmental perturbations over the 21st century because of climate change (rising temperatures) and the abandonment of agro-pastoral areas (reforestation). Both changes are happening at similar timescales and are expected to have an impact on snow cover. The effect of climate change on snow in the Pyrenees is well understood , but the effect of land cover changes is much less documented. Here, we analyze the response of snow cover to a combination of climate and land cover change scenarios in a small Pyrenean catchment (Bassiès, 14.5 km 2 , elevation range 940–2651 m a.s.l.) using a distributed snowpack evolution model. Climate scenarios were constructed from the output of regional climate model projections, whereas land cover scenarios were generated based on past observed changes and an inductive pattern-based model. The model was validated over a snow season using in situ snow depth measurements and high-resolution snow cover maps derived from SPOT (Satellite Pour l'Observation de la Terre – Earth Observation Satellite) satellite images. Model projections indicate that both climate and land cover changes reduce the mean snow depth. However, the impact on the snow cover duration is moderated in reforested areas by the shading effect of trees on the snow surface radiation balance. Most of the significant changes are expected to occur in the transition zone between 1500 m a.s.l. and 2000 m a.s.l. where (i) the projected increase in air temperatures decreases the snow fraction of the precipitation and (ii) the land cover changes are concentrated. However, the consequences on the runoff are limited because most of the meltwater originates from high-elevation areas of the catchment, which are less affected by climate change and reforestation
Poincaré’s Equations for Cosserat Media: Application to Shells

International audienceIn 1901 Henri Poincaré discovered a new set of equations for mechanics. These equations are a generalization of Lagrange's equations for a system whose configuration space is a Lie group which is not necessarily commutative. Since then, this result has been extensively refined through the Lagrangian reduction theory. In the present contribution, we extend these equations from classical mechanical systems to continuous Cosserat media, i.e. media in which the usual point particles are replaced by small rigid bodies, called micro-structures. In particular, we will see how the Shell balance equations used in nonlinear structural dynamics, can be easily derived from this extension of the Poincaré's result
Propagation Engine Prototyping with a Domain Specific Language

International audienceConstraint propagation is at the heart of constraint solvers. Two main trends co-exist for its implementation: variable-oriented propagation engines and constraint-oriented propagation engines. Those two approaches ensure the same level of local consistency but their efficiency (computation time) can be quite different depending on the instance solved. However, it is usually accepted that there is no best approach in general, and modern constraint solvers implement only one. In this paper, we would like to go a step further providing a solver independent language at the modeling stage to enable the design of propagation engines. We validate our proposal with a reference implementation based on the Choco solver and the MiniZinc constraint modeling language
Evaluation of the Effect of Chemical or Enzymatic Synthesis Methods on Biodegradability of Polyesters

International audienceThis work compares the biodegradability of polyesters produced by an esterification reaction between glycerol and oleic di-acid (D 18:1) issued from green chemical pathways, via either classical thermo-chemical methods, or an enzymatic method using the immobilized lipase of Candida antartica B (Novozym 435). An elastomeric polymer synthesized by enzymatic catalysis is more biodegradable than an elastomeric thermo-chemical polyester synthesized by a standard chemical procedure. This difference lies in percentage of the dendritic motifs, in values of the degree of substitution, and certainly in cross-links inducing an hyper-branched structure less accessible to the lipolytic enzymes in a waste treatment plant. However, when the elastomeric polymer synthesized by enzymatic catalysis is processed at high temperature as required for certain industrial applications, it presents an identical rate of biodegradation than the chemical polyester. The advantages of the thermo-chemical methods are greater speed and lower cost. Enzymatic synthesis appears be suited to producing polyesters, devoid of metallic catalysts, which must be used without processing at high temperature to keep a high biodegradability
Nuclear structure studies of $^{24}$F

5 figures, 2 tables, Expérience GANIL/LISEInternational audienceThe structure of the $^{24}$F nucleus has been studied at GANIL using the $\beta$ decay of $^{24}$O and the in-beam $\gamma$-ray spectroscopy from the fragmentation of projectile nuclei. Combining these complementary experimental techniques, the level scheme of $^{24}$F has beenconstructed up to 3.6 Mev by means of particle-$\gamma$ and particle-$\gamma\gamma$ coincidence relations. Experimental results are compared to shell-model calculations using the standard USDA and USDB interactions as well as ab-initio valence-space Hamiltonians calculated from the in-medium similarity renormalization group based on chiral two- and three-nucleon forces.  Both methods reproduce the measured level spacings well, and this close agreement allows unidentified spins and parities to be consistently assigned
Breakdown of the Z = 8 Shell Closure in Unbound $^{12}$O and its Mirror Symmetry

Expérience GANIL, SISSI, MUST2/E537International audienceAn excited state in the proton-rich unbound nucleus 12O was identified at 1.8(4) MeV via missing-mass spectroscopy with the 14Oðp; tÞ reaction at 51 AMeV. The spin-parity of the state was determined to be 0þ or 2þ by comparing the measured differential cross sections with distorted-wave calculations. The lowered location of the excited state in 12O indicates the breakdown of the major shell closure at Z ¼ 8 near the proton drip line. This demonstrates the persistence of mirror symmetry in the disappearance of the magic number 8 between 12O and its mirror partner 12Be
Abrupt climate changes for Iceland during the last millennium: evidence from high resolution sea ice reconstructions

International audienceA high resolution account of Icelandic sea ice over the last millennium has been constructed using a novel proxy based on the presence in sediments of a biomarker (IP25) produced by sea ice algae. Comparison with historical sea ice records demonstrates a strong correlation between documented sea ice occurrences and the IP25 proxy. An excellent agreement is also observed between the IP25 record and a diatom-based sea surface temperature reconstruction obtained from the same core and the Crowley and Lowery Northern Hemisphere temperature reconstruction. Using this approach, we provide new historical sea ice data for periods where records are scarce or absent and evidence for abrupt changes to sea ice and/or climate conditions around Iceland during the Little Ice Age
Strong chemical evidence for high Fe(II)-colloids and low As-bearing colloids (200 nm–10 kDa) contents in groundwater and flooded paddy fields in Bangladesh: A size fractionation approach

International audienceArsenic speciation in groundwater and interstitial waters from soil irrigated with As-rich groundwater in Bangladesh was investigated through a size fractionation approach performed in the field and under con-ditions that allowed the preservation of natural anoxic conditions. Based on a simple chemical character-ization, the presence of Fe(II) in the colloidal fraction (<200 nm–>10 kDa) in anoxic groundwaters and soil waters of flooded paddy fields was assessed. Arsenic was found to be present mainly as a ''solute'' oxy-anion as indicated by the small amount of As associated with the 200 nm–10 kDa colloidal fraction (most of the time, less than 10 ± 5% of total As). When As-colloids were observed, they were linked to high Fe concentration and the As-colloid percentage was relatively well correlated with the total Fe concentra-tion in solution. This study underlined that under natural anoxic conditions, there was no impact of PO 3À 4 , SiO 4À 4 and Mn on the As-bearing colloids, which is not in agreement with results obtained under laboratory controlled conditions. Therefore, it is suspected that the impact of other naturally occurring ligands, such as organic matter, could modify Fe(II) speciation, and, in turn, As speciation. To assess the complexation of Fe(II) by organic matter, the WinHumicV model was used to calculate Fe(II) specia-tion. Using the standard parameters to describe organic matter reactivity, results showed that organi-cally-bound Fe(II) ranges from 5% to 100% and 30% to 100%, for groundwater and soil water, respectively, depending on the pH and the Fe(II) and DOC contents. Evidence for independent speciation of Fe and As under natural anoxic conditions is of great importance for predictive modelling of the mobil-ity, the availability and then the bioavailability of As in As-affected areas
Characterization of Brazilian Peat Samples by Applying a Multi-Method Approach

International audiencePeat is a mixture of compounds formed by the decomposition of plant residues and mineral materials that have accumulated at the bottom of ponds and flooded depressions in riverine areas. Due to their extreme heterogeneity and natural variety, the physical and chemical properties of peat can vary widely within or between deposits, and the characterization of isolated samples is still a challenging task that requires the combination of several chemical and spectroscopic methodologies. In this study, the structural characteristics of two Brazilian peat samples were evaluated using scanning electron microscopy (SEM), elemental (CHNS-O) and thermal (TGA) analysis, X-ray diffraction (XRD), and infrared (FT-IR) and solid-state 13C nuclear magnetic resonance (13C NMR) spectroscopies. Although the samples originated from the same peatland, the data showed that the studied samples have distinct chemical properties and that the stage of decomposition played an important role in the differences observed
In Situ Stabilization of Trace Metals in a Copper-Contaminated Soil using P-Spiked Linz-Donawitz Slag

International audienceP-spiked Linz-Donawitz (LD) slag was used as a soil additive to improve physico-chemical soil properties and in situ stabilize Cu and other trace metals in a sandy Cu-contaminated soil (630 mg kg-1 soil) from a former wood preservation site. The LD slag was incorporated into the contaminated soil to consist four treatments: 0 % (T1), 1 % (T2), 2 % (T3), and 4 % (T4) per air-dried soil weight. A similar uncontaminated soil was used as a control (CTRL). After a one-month reaction period, potted soils (1kg) were used for a 2-week growth experiment with dwarf beans (Phaseolus vulgaris L.). Soil pH increased with the incorporation rate of LD slag from 5.7 in the T1 soil up to 7.9 in the T4 soil. Similarly the soil electrical conductivity (EC, in mS cm- 1) rose from 0.15 (T1 soil) up to 1.17 (T4 soil). Bean plants grown on the T1 soil showed a high phytotoxicity. All incorporation rates of LD slag increased the root and shoot dry weight yields compared to the untreated soil (T1). The foliar Ca concentration of beans was enhanced for all LD slag-amended soils, while the foliar Mg, K, and P concentrations were not increased. Foliar Cu, Zn, and Cr concentrations of beans decreased with the LD slag incorporation rate. The 2% incorporation rate was sufficient to obtain the highest bean growth and foliar Ca concentration, to reduce foliar Cu concentration below its upper critical value, and to avoid an excessive soil EC and Zn deficiency
Phase Properties of Laser High-Order Harmonics Generated on Plasma Mirrors

International audienceAs a high-intensity laser-pulse reflects on a plasma mirror, high-order harmonics of the incident frequency can be generated in the reflected beam. We present a numerical study of the phase properties of these individual harmonics, and demonstrate experimentally that they can be coherently controlled through the phase of the driving laser field. The harmonic intrinsic phase, resulting from the generation process, is directly related to the coherent sub-laser-cycle dynamics of plasma electrons, and thus constitutes a new experimental probe of these dynamics
Entropy and temperature gradients thermomechanics: Dissipation, heat conduction inequality and heat equation

International audienceAn alternative and consistent approach, not appealing to the principle of virtual power and to Coleman-Noll procedure, is used to derive constitutive and governing equations involving temperature or entropy gradients, in thermomechanics of materials. Using the balance of energy, an analysis of the dissipation naturally leads to the definition of the temperature and the entropy as variational derivatives. The approach preserves the classical forms of the equations and yields to consistent form of the second law and heat conduction inequality. The framework of generalized standard materials is then suitable for deriving admissible constitutive laws. The methodology is applied, first using entropy and its gradient as state variables (with internal energy as thermodynamic potential), and second using temperature and its gradient (starting from the free energy)
A re-assessment of aerosol size distributions from Masaya volcano (Nicaragua)

International audienceCascade impactors were used to sample volcanic aerosol from Masaya (Nicaragua) in 2007, 2009 and 2010. Differences were found in the size distributions of volcanic aerosol between these recent campaigns and with a campaign in 2001: (1) SO42− showed modes in both the fine (<1 μm; with low Na+/K+) and coarse (>1 μm; with high Na+/K+) fractions in all of the recent campaigns despite being unimodal in 2001 (<1 μm); (2) The modal diameters for SO42− roughly doubled in 2009, compared to 2007 or 2010; (3) total Cl− was depleted in volcanic aerosol compared to background aerosol in all the more recent campaigns but was enriched in 2001. Other aspects of the volcanic aerosol appear to be persistent, such as a fine SO42−-H+-Na+-K+ mode, which was the most abundant mode in all campaigns, and a coarse Cl−-F−-Mg2+-Ca2+ mode of lower abundance. Water uptake and speciation in the aerosol were investigated using the equilibrium model, ISORROPIA II. Results show that the coarse SO42−-rich mode deliquesces at lower relative humidity (40% RH) than the fine SO42−-rich mode (50% RH) due to increased Na+/K+ in the former. The aerosol was predicted to be dry at ambient relative humidity in 2009 and dominated by NaHSO4, KHSO4, CaSO4 and MgSO4. In contrast, model results predict a liquid aerosol at ambient relative humidity in 2010. These results indicate that aerosol emissions from a volcano can vary in ionic composition and even more so in physical speciation (i.e., salts or solutions). These observations are set against a near-constant magmatic gas composition at Masaya, which highlights the significance of atmospheric and dynamic factors in the formation of volcanic aerosols
Bubble nucleation, growth and coalescence during the 1997 Vulcanian explosions of Soufrière Hills Volcano, Montserrat

International audienceSoufrière Hills Volcano had two periods of repetitive Vulcanian activity in 1997. Each explosion discharged the contents of the upper 0.5–2 km of the conduit as pyroclastic flows and fallout: frothy pumices from a deep, gas-rich zone, lava and breadcrust bombs from a degassed lava plug, and dense pumices from a transition zone. Vesicles constitute 1–66 vol.% of breadcrust bombs and 24–79% of pumices, all those larger than a few tens of µm being interconnected. Small vesicles (< few tens of µm) in all pyroclasts are interpreted as having formed syn-explosively, as shown by their presence in breadcrust bombs formed from originally non-vesicular magma. Most large vesicles (> few hundreds of µm) in pumices are interpreted as pre-dating explosion, implying pre-explosive conduit porosities up to 55%. About a sixth of large vesicles in pumices, and all those in breadcrust bombs, are angular voids formed by syn-explosive fracturing of amphibole phenocrysts. An intermediate-sized vesicle population formed by coalescence of the small syn-explosive bubbles. Bubble nucleation took place heterogeneously on titanomagnetite, number densities of which greatly exceed those of vesicles, and growth took place mainly by decompression. Development of pyroclast vesicle textures was controlled by the time interval between the onset of explosion–decompression and surface quench in contact with air. Lava-plug fragments entered the air quickly after fragmentation (not, vert, similar 10 s), so the interiors continued to vesiculate once the rinds had quenched, forming breadcrust bombs. Deeper, gas-rich magma took longer (not, vert, similar 50 s) to reach the surface, and vesiculation of resulting pumice clasts was essentially complete prior to surface quench. This accounts for the absence of breadcrusting on pumice clasts, and for the textural similarity between pyroclastic flow and fallout pumices, despite different thermal histories after leaving the vent. It also allowed syn-explosive coalescence to proceed further in the pumices than in the breadcrust bombs. Uniaxial boudinage of amphibole phenocrysts in pumices implies significant syn-explosive vesiculation even prior to magma fragmentation, probably in a zone of steep pressure gradient beneath the descending fragmentation front. Syn-explosive decompression rates estimated from vesicle number densities (> 0.3–6.5 MPa s− 1) are consistent with those predicted by previously published numerical models
Maximum Stress Intensity Factor for a Circumferential Crack in a Finite-Length Thin-Walled Cylinder under Transient Radial Temperature Distribution

Transient stress intensity factor of an axisymmetric circumferential crack in a finite-length, thin-walled and edges
	rotation-restrained cylinder, which is suddenly cooled inside from uniform temperature distribution was formulated. Then
	the effects of various structural parameters and heat transfer conditions on the value were studied. The maximum transient
	stress intensity factor in a thermal cycle showed a tendency to decrease monotonously when crack length was varied to
	become longer than a specific value. Furthermore, the maximum transient stress intensity factor for an infinite cylinder
	length was smaller than that for a specific length when cylinder length was varied
Antimuscarinic Drug Inhibits Detrusor Overactivity Induced by Topical Application of Prostaglandin E2 to the Urethra With a Decrease in Urethral Pressure

Purpose: Antimuscarinic drugs increase bladder capacity without prominent side effects such as urinary retention even when administered to patients with mild to moderate BOO. Some mechanisms might exist in the urethra to compensate for the emptying function of the detrusor after administration of antimuscarinic drugs. We investigated the influences of an antimuscarinic drug, propiverine, on urethral function.
	Materials and Methods: Urethral pressure and rhythmic bladder pressure were simultaneously monitored in urethane-anesthetized female Sprague-Dawley rats. PGE2 was continuously administered intravesically or intraurethrally to induce detrusor overactivity. Next, to eliminate the influence of bladder activity and to monitor urethral baseline pressure, isovolumetric pressure of the urethra was recorded after cystectomy and ligation of the external urethral meatus. Furthermore, the in vitro contractile responses of the urethral circular smooth muscle to field stimulation were examined in the presence of propiverine, tamsulosin, verapamil, ω-conotoxin, and atropine.
	Results: The intravesical or intraurethral administration of PGE2 significantly decreased bladder contraction interval (BCI) by 10.7% and 36.0%, respectively. The intraarterial administration of 2x102 nM/kg propiverine significantly increased BCI in rats receiving intraurethral PGE2 by 81.8%, but had no marked effect on rats receiving intravesical PGE2. Significant decreases in urethral baseline pressure were found after propiverine administration. Field stimulation-induced contraction was inhibited by propiverine and verapamil, but not by tamsulosin, ω-conotoxin or atropine.
	Conclusions: These results suggest that inhibitory effects of propiverine are more prominent in rats with detrusor overactivity induced by intraurethral PGE2 than those by intravesical PGE2. Propiverine may compensate for detrusor function by decreasing urethral resistance in the voiding phase
Embryonic Cerebrospinal Fluid Collaborates With the Isthmic Organizer To Regulate Mesencephalic Gene Expression

Producción CientíficaEarly in development, the behavior of neuroepithelial
cells is controlled by several factors acting in a developmentally
regulated manner. Recently it has been
shown that diffusible factors contained within embryonic
cerebrospinal fluid (CSF) promote neuroepithelial
cell survival, proliferation, and neurogenesis in mesencephalic
explants lacking any known organizing center.
In this paper, we show that mesencephalic and mesencephalic
þ isthmic organizer explants cultured only with
basal medium do not express the typically expressed
mesencephalic or isthmic organizer genes analyzed
(otx2 and fgf8, respectively) and that mesencephalic
explants cultured with embryonic CSF-supplemented
medium do effect such expression, although they
exhibit an altered pattern of gene expression, including
ectopic shh expression domains. Other trophic sources
that are able to maintain normal neuroepithelial cell
behavior, i.e., fibroblast growth factor-2, fail to activate
this ectopic shh expression. Conversely, the expression
pattern of the analyzed genes in mesencephalic þ isthmic
organizer explants cultured with embryonic cerebrospinal
fluid-supplemented medium mimics the
pattern for control embryos developed in ovo. We demonstrate
that embryonic CSF collaborates with the isthmic
organizer in regulation of the expression pattern of
some characteristic neuroectodermal genes during
early stages of central nervous system (CNS) development,
and we suggest that this collaboration is not
restricted to the maintenance of neuroepithelial cell
survival. Data reported in this paper corroborate the
hypothesis that factors contained within embryonic
CSF contribute to the patterning of the CNS during
early embryonic development.2015-09-0
Liquid Water through Density-Functional Molecular Dynamics: Plane-Wave
  vs Atomic-Orbital Basis Sets

We determine and compare structural, dynamical, and electronic properties of
liquid water at near ambient conditions through density-functional molecular
dynamics simulations, when using either plane-wave or atomic-orbital basis
sets. In both frameworks, the electronic structure and the atomic forces are
self-consistently determined within the same theoretical scheme based on a
nonlocal density functional accounting for van der Waals interactions. The
overall properties of liquid water achieved within the two frameworks are in
excellent agreement with each other. Thus, our study supports that
implementations with plane-wave or atomic-orbital basis sets yield equivalent
results and can be used indiscriminately in study of liquid water or aqueous
solutions