pinecone/core-2020-05-10-deduplication huggingface dataset:
Structural changes induced by heavy ion irradiation in titanium silicon carbide

International audienceCarbide-type ceramics, which have remarkable thermomechanical properties, are sensed to manufacture the fuel cladding of Generation IV reactors that should work at high temperature. The MAX phases, and more particularly titanium silicon carbide, are distinguished from other materials by their ability to have some plasticity, even at room temperature. For this study, polycrystalline Ti3SiC2 was irradiated with ions of different energies, which allow to discriminate the effect of both electronic and nuclear interactions. After characterization by low-incidence X-ray diffraction and cross-sectional transmission electron microscopy, it appears that Ti3SiC2 is not sensitive to electronic excitations while nuclear shocks damage its structure. The results show the creation of many defects and disorder in the structure, an expansion of the hexagonal close-packed lattice along the c axis, and an increase in the microstrain yield
Does Work Pay in France? Monetary Incentives, Hours Constraints and the Guaranteed Minimum Income

International audienceThis paper uses a representative sample of individuals on France's main welfare program (the Revenu Minimum d'Insertion, or RMI) to estimate monetary incentives for employment among welfare recipients. Based on the estimated joint distribution of wages and hours potentially offered to each individual, we compute potential gains from working in a very detailed<br />manner. Relating these gains to observed employment, we then estimate a simple structural labor supply model. We find that potential gains are almost always positive but very small on average, especially for single mothers,<br />because of the high implicit marginal tax rates embedded in the system. Employment rates are sensitive to incentives with extensive margin elasticities<br />for both men and women usually below one. Conditional on these elasticities, simulations indicate that existing policies devoted to reducing marginal tax rates at the bottom of the income distribution, such as the intéressement earnings top-up program, have little impact in this population due to their very limited scope. The recently introduced negative income tax (Prime pour l'emploi), seems to be an exception
Asymptotic and bootstrap inference for inequality and poverty measures

International audienceA random sample drawn from a population would appear to offer an ideal opportunity to use the bootstrap in order to perform accurate inference, since the observations of the sample are IID. In this paper, Monte Carlo results suggest that bootstrapping a commonly used index of inequality leads to inference that is not accurate even in very large samples, although inference with poverty indices is satisfactory. We find that the major cause is the extreme sensitivity of many inequality indices to the exact nature of the upper tail of the income distribution. This leads us to study two non-standard bootstraps, the m out of n bootstrap, which is valid in some situations where the standard bootstrap fails, and a bootstrap in which the upper tail is modelled parametrically. Monte Carlo results suggest that accurate inference can be achieved with this last method in moderately large samples
Messinian evaporite deposition during sea level rise in the Gulf of Lions (Western Mediterranean)

International audienceThe Messinian Salinity Crisis resulted from desiccation of the Mediterranean Sea after its isolation from the Atlantic Ocean at the end of the Miocene. Stratal geometry tied to borehole data in the Gulf of Lions show that the pre-crisis continental shelf has been eroded during a major sea-level fall and that sedi-ments from this erosion have been deposited in the basin. This detrital package is onlapped by high amplitude seismic reflectors overlain by the "Messinian Salt" and the "Upper Evaporites". Towards the shelf, the transition between regressive deposits and overlying onlapping sediments is characterised by a wave-ravinement surface, suggesting that a significant part of the onlapping reflectors and overlying Messinian Evaporites were deposited during a relatively slow landward migration of the shoreline. The clear boundary between the smooth wave-ravinement surface and the subaerial Messinian Erosional Surface observed on the Gulf of Lions shelf and onshore in the Rh^ one valley is interpreted to have resulted from a rapid acceleration of the Mediterranean sea level rise at the end of the Messinian Salinity Crisis. Numerical simulation of this cycle of sea level change during the Messinian Salinity Crisis and of precipitation of thick evaporites during the slow sea level rise shows that this scenario can be modelled assuming a value of evaporation minus precipitation of 1.75 m 3 /m 2 /yr in the deep Mediterranean basins
Experimental simulation of evaporation-driven silica sinter formation and microbial silicification in hot spring systems.

International audienceEvaporation of silica-rich geothermal waters is one of the main abiotic drivers of the formation of silica sinters around hot springs. An important role in sinter structural development is also played by the indigenous microbial communities, which are fossilized and eventually encased in the silica matrix. The combination of these two factors results in a wide variety of sinter structures and fabrics. Despite this, no previous experimental fossilization studies have focused on evaporative-driven silica precipitation. We present here the results of several experiments aimed at simulating the formation of sinters through evaporation. Silica solutions at different concentrations were repeatedly allowed to evaporate in both the presence and absence of the cyanobacterium Synechococcus elongatus. Without microorganisms, consecutive silica additions led to the formation of well-laminated deposits. By contrast, when microorganisms were present, they acted as reactive surfaces for heterogeneous silica particle nucleation; depending on the initial silica concentration, the deposits were then either porous with a mixture of silicified and unmineralized cells, or they formed a denser structure with a complete entombment of the cells by a thick silica crust. The deposits obtained experimentally showed numerous similarities in terms of their fabric to those previously reported for natural hot springs, demonstrating the complex interplay between abiotic and biotic processes during silica sinter growth
Monitoring micrometer-scale collagen organization in rat-tail tendon upon mechanical strain using second harmonic microscopy.

International audienceWe continuously monitored the microstructure of a rat-tail tendon during stretch/relaxation cycles. To that purpose, we implemented a new biomechanical device that combined SHG imaging and mechanical testing modalities. This multi-scale experimental device enabled simultaneous visualization of the collagen crimp morphology at the micrometer scale and measurement of macroscopic strain-stress response. We gradually increased the ultimate strain of the cycles and showed that preconditioning mostly occurs in the first stretching. This is accompanied by an increase of the crimp period in the SHG image. Our results indicate that preconditioning is due to a sliding of microstructures at the scale of a few fibrils and smaller, that changes the resting length of the fascicle. This sliding can reverse on long time scales. These results provide a proof of concept that continuous SHG imaging performed simultaneously with mechanical assay allows analysis of the relationship between macroscopic response and microscopic structure of tissues
Discrete volumetric digital image correlation for the investigation of granular type media at microscale : accuracy assessment

International audienceThe recent development of eﬃcient 3D imaging tools such as X-Rays computed microtomography combined with the extension to volumetric images of Digital Image Correlation (DIC) techniques provide new insights on the analysis of materials and structures. Among many other possible ﬁelds of application, geomaterials are good candidates for such investigations, owing to their relative transparency to X-rays and the presence in many samples of a natural contrast suitable for deformation mapping. However, these materials often deform discontinuously at microscale, for instance in the form of the development of a networks of microcracks. Discontinuity is even the dominant rule in granular-type materials such as sand in which the contribution to overall deformation of the microcontinuous phenomena -elastic strains inside grains- are negligible. To investigate deformation at the scale of these discontinuous mechanisms, speciﬁc DIC algorithms are required, which override the assumption of continuity of the transformation at the scale of the correlation windows. The recent so-called Discrete-DIC procedure (Hall et al, 2010) is a possible answer. We recall here its general principles and focus on its potential accuracy, from both theoretical and practical points of view. We show that the position and the rotation of individual grains with an average diameter of 500µm can be determined from images recorded with a laboratory microCT scanner, with a 15µm voxel size, with an accuracy of the order of 1µm and 0,1 degree, respectively
Recent Results on the Periodic Lorentz Gas

62 pages. Course at the conference ''Topics in PDEs and applications 2008" held in Granada, April 7-11th 2008; figure 13 and a misprint in Theorem 4.6 corrected in the new versionInternational audienceThe Drude-Lorentz model for the motion of electrons in a solid is a classical model in statistical mechanics, where electrons are represented as point particles bouncing on a fixed system of obstacles (the atoms in the solid). Under some appropriate scaling assumption --- known as the Boltzmann-Grad scaling by analogy with the kinetic theory of rarefied gases --- this system can be described in some limit by a linear Boltzmann equation, assuming that the configuration of obstacles is random [G. Gallavotti, [Phys. Rev. (2) {\bf 185} (1969), 308]). The case of a periodic configuration of obstacles (like atoms in a crystal) leads to a completely different limiting dynamics. These lecture notes review several results on this problem obtained in the past decade as joint work with J. Bourgain, E. Caglioti and B. Wennberg
Stochastic Downscaling Method: Application to Wind Refinement

International audienceIn this article, we propose a new stochastic downscaling method: provided a numerical prediction of wind at large scale, we aim to improve the approximation at small scales thanks to a local stochastic model. We first recall the framework of a Lagrangian stochastic model borrowed from S.B. Pope. Then, we adapt it to our meteorological framework, both from the theoretical and numerical viewpoints. Finally, we present some promising numerical results corresponding to the simulation of wind over the Mediterranean Sea
The fate of early Mars' lost water: The role of serpentinization

International audienceThe fate of water which was present on early Mars remains enigmatic. We propose a simple model based on serpentinization, a hydrothermal alteration process which may produce magnetite and store water. Our model invokes serpentinization during about 500 to 800 Myr, while a dynamo is active, which may have continued after the formation of the crustal dichotomy. We show that the present magnetic field measured by MGS in the Southern hemisphere is consistent with a ~500 m thick Global Equivalent Layer of water trapped in serpentine. Serpentinization results in the release of H2. The released H atoms are lost to space through thermal escape, increasing the D/H ratio in water reservoirs exchanging with atmosphere. We show that the value of the D/H ratio in the present atmosphere (~5) is consistent with the serpentinization of a ~500 m thick water GEL. We reassess the role of non-thermal escape in removing water from the planet. By considering an updated solar wind-ionosphere interaction representation, we show that the contribution of oxygen escape to H isotopic fractionation is negligible. Our results suggest that significant amounts of water (up to a ~330-1030 m thick GEL) present at the surface during the Noachian, similar to the quantity inferred from the morphological analysis of valley networks, could be stored today in subsurface serpentine
White organic light-emitting diodes with an ultra-thin premixed emitting layer

International audienceWe described an approach to achieve fine color control of fluorescent White Organic Light-Emitting Diodes (OLED), based on an Ultra-thin Premixed emitting Layer (UPL). The UPL consists of a mixture of two dyes (red-emitting 4-di(4′-tert-butylbiphenyl-4-yl)amino-4′-dicyanovinylbenzene or fvin and green-emitting 4-di(4′-tert-butylbiphenyl-4-yl)aminobenzaldehyde or fcho) premixed in a single evaporation cell: since these two molecules have comparable structures and similar melting temperatures, a blend can be evaporated, giving rise to thin films of identical and reproducible composition compared to those of the pre-mixture. The principle of fine color tuning is demonstrated by evaporating a 1-nm-thick layer of this blend within the hole-transport layer (4,4′-bis[N-(1-naphtyl)-N-phenylamino]biphenyl (α-NPB)) of a standard fluorescent OLED structure. Upon playing on the position of the UPL inside the hole-transport layer, as well as on the premix composition, two independent parameters are available to finely control the emitted color. Combined with blue emission from the heterojunction, white light with Commission Internationale de l'Eclairage 1931 color coordinates (0.34, 0.34) was obtained, with excellent color stability with the injected current. The spectrum reveals that the fcho material does not emit light due to efficient energy transfer to the red-emitting fvin compound but plays the role of a host matrix for fvin, allowing for a very precise adjustment of the red dopant amount in the device
Approximating partial derivatives of first and second order by quadratic spline quasi-interpolants

paru dans la revue sous le titre : Approximating partial derivatives of first and second order by quadratic spline quasi-interpolants on uniform meshesGiven a bivariate function $f$ defined in a rectangular domain $\omega$, we approximate it by a $C^1$ quadratic spline quasi-interpolant (abbr. QI) and we take partial derivatives of this QI as approximations to those of $f$. We give error estimates and asymptotic expansions for these approximations. We also propose a simple algorithm for the determination of stationary points, illustrated by a numerical example
Sol-gel derived mesoporous Pt and Cr-doped WO(3) thin films: the role played by mesoporosity and metal doping in enhancing the gas sensing properties

Mesoporous Cr or Pt-doped WO(3) thin films to be employed as ammonia gas sensors were prepared by a fast one-step sol-gel procedure, based on the use of triblock copolymer as templating agent. The obtained films were constituted by aggregates of interconnected WO(3) nanocrystals (20-50 nm) separated by mesopores with dimensions ranging between 2 and 15 nm. The doping metals, Pt and Cr, resulted differently hosted in the WO(3) mesoporous matrix. Chromium is homogeneously dispersed in the oxide matrix, mainly as Cr(III) and Cr(V) centers, as revealed by EPR spectroscopy; instead platinum segregated as Pt (0) nanoparticles (4 nm) mainly included inside the WO(3) nanocrystals. The semiconductor layers containing Pt nanoclusters revealed, upon exposure to NH(3), remarkable electrical responses, much higher than Cr-doped and undoped layers, particularly at low ammonia concentration (6.2 ppm). This behavior was attributed to the presence of Pt nanoparticles segregated inside the semiconductor matrix, which act as catalysts of the N-H bond cleavage, decreasing the activation barrier in the ammonia dissociation. The role of the mesoporous structure in influencing the chemisorption and the gas diffusion in the WO(3) matrix appeared less decisive than the electronic differences between the two examined doping metals. The overall results suggest that a careful combination between mesoporous architecture and metal doping can really promote the electrical response of WO(3) toward ammonia
The future of interpretive accounting research—A polyphonic debate

In 1997-99 the three of us organised a series of European Commission funded
conferences aimed at building a network of young researchers in the area of
accounting. At the time “young” was defined by the Commission as researchers
under 35 years of age (allowing for maternity leave or national service). Over the
intervening years our network had grown and we wanted to try and take stock of the
field in which we had now been working for a surprising number of years. To that
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end we put together the above email and a broad invitation list of people who had
been at those first meetings, and others of the same generation (or even younger)
whom we had met since.
About half of those originally contacted managed to make the meeting where we
spent a stimulating couple of hours of debate on the topics raised below—so
stimulating that we developed a collective desire to leave a trace of the discussion.
Writing a traditional paper with so many, so widely dispersed authors was not going
to work. Instead we came up with a different form of collective writing that mirrored
the original debate, and that might contribute to ongoing debates in this journal
concerning the nature and status of our research (e.g. Arrington, 2004; Inanga &
Schneider, 2005; Macintosh, 2004). We agreed a process in which each of us in turn
would have one week to add a target of 300 words to a rolling document, going
through the contributors alphabetically. After two rounds we would see what we had
got
TAT-mediated peroxiredoxin 5 and 6 protein transduction protect against high glucose-induced cytotoxicity in retinal pericytes

Aims: Hyperglycemia-induced oxidative stress is implicated to be involved in pericyte
apoptosis seen in diabetic retinopathy. The six mammalian Peroxiredoxins (PRDXs)
comprise a novel family of antioxidative proteins that negatively regulate oxidative
stress-induced apoptosis by controlling reactive oxygen species (ROS) levels.
Main methods: Sprague Dawley rats were used to detect the retinal expressions of
PRDXs1-6. Pig pericytes cultured in high-glucose medium were used to monitor the
protective effect of PRDX5 and 6 against high-glucose- associated change. Recombinant
PRDX5 and 6 proteins were linked to the Trans-Activating Transduction (TAT) domain
from HIV-1 TAT protein for their efficient delivery into cells/tissues.
Key findings: We found higher expression of PRDX5 and 6 mRNAs and PRDX5 and 6
proteins in retina than the other Prdxs (Prdx 1–4). Western blotting affirmed the
intracellular presence of TAT-linked proteins and revealed the efficient transduction of
TAT-HA-PRDX5 and 6 in these cells. Extrinsic supply of TAT-HA-PRDX5 and 6 proteins
inhibited the oxidative stress induced DNA damage after high-glucose exposure in pig
pericytes. The cell survival and apoptosis assay revealed that extrinsic supply of TATHA-
PRDX5 and 6 proteins were responsible for inhibiting hyperglycemia-induced pericyte
2
apoptosis.
Significance: Results suggest that delivery of PRDX5 and 6 might protect hyperglycemiainduced
pericyte loss to inhibit oxidative stress
An optical system for monitoring torsion in a power transmission shaft in realtime

An optical system has been proposed and verified experimentally for monitoring the torsion of a power transmission shaft in realtime.  The system consists of a pair of lasers, mirrors and light receivers as a sensor head, and logic circuit, high-frequency oscillator, and computer as a data processing system.  The smallest measurable angle of torsion can be expressed by ω/ƒ, where ω is the rotational frequency of the power transmission shaft and ƒ is the frequency of the oscillator.  The experimental error was found to be a few percentage points
What can we learn from neutrinoless double beta decay experiments?

We assess how well next-generation neutrinoless double beta decay and normal neutrino beta decay experiments can answer four fundamental questions. (1) If neutrinoless double beta decay searches do not detect a signal, and if the spectrum is known to be inverted hierarchy, can we conclude that neutrinos are Dirac particles? (2) If neutrinoless double beta decay searches are negative and a next-generation ordinary beta decay experiment detects the neutrino mass scale, can we conclude that neutrinos are Dirac particles? (3) If neutrinoless double beta decay is observed with a large neutrino mass element, what is the total mass in neutrinos? (4) If neutrinoless double beta decay is observed, but next-generation beta decay searches for a neutrino mass only set a mass upper limit, can we establish whether the mass hierarchy is normal or inverted? We base our answers on the expected performance of next-generation neutrinoless double beta decay experiments and on simulations of the accuracy of calculations of nuclear matrix elements
Asynchronous Networks and Event Driven Dynamics

Real-world networks in technology, engineering and biology often exhibit dynamics that cannot be adequately reproduced using network models given by smooth dynamical systems and a fixed network topology. Asynchronous networks give a theoretical and conceptual framework for the study of network dynamics where nodes can evolve independently of one another, be constrained, stop, and later restart, and where the interaction between different components of the network may depend on time, state, and stochastic effects. This framework is sufficiently general to encompass a wide range of applications ranging from engineering to neuroscience. Typically, dynamics is piecewise smooth and there are relationships with Filippov systems. In the first part of the paper, we give examples of asynchronous networks, and describe the basic formalism and structure. In the second part, we make the notion of a functional asynchronous network rigorous, discuss the phenomenon of dynamical locks, and present a foundational result on the spatiotemporal factorization of the dynamics for a large class of functional asynchronous networks
Toward automated evaluation of interactive segmentation

We previously described a system for evaluating interactive segmentation by means of user experiments (McGuinness and O’Connor, 2010). This method, while effective, is time-consuming and labor-intensive. This paper aims to make evaluation more practicable by investigating if it is feasible to automate user interactions. To this end, we propose a general algorithm for driving the segmentation that uses the ground truth and current segmentation error to automatically simulate user interactions. We investigate four strategies for selecting which pixels will form the next interaction. The first of these is a simple, deterministic strategy; the remaining three strategies are probabilistic, and focus on more realistically approximating a real user. We evaluate four interactive segmentation algorithms using these strategies, and compare the results with our previous user experiment-based evaluation. The results show that automated evaluation is both feasible and useful
The Oxford Questions on the foundations of quantum physics

The twentieth century saw two fundamental revolutions in physics—relativity and quantum. Daily use of these theories can numb the sense of wonder at their immense empirical success. Does their instrumental effectiveness stand on the rock of secure concepts or the sand of unresolved fundamentals? Does measuring a quantum system probe, or even create, reality, or merely change belief? Must relativity and quantum theory just co-exist or might we find a new theory which unifies the two? To bring such questions into sharper focus, we convened a conference on 'Quantum Physics and the Nature of Reality'. Some issues remain as controversial as ever, but some are being nudged by theory’s secret weapon of experiment