pinecone/core-2020-05-10-deduplication huggingface dataset:
Shear induced structuration of liquid crystalline epoxy thermosets

International audienceLow-molecular weight liquid crystals (LC) have wide technological applications due to their self-assembly in the mesophase. An azomethine nematic monomer based on diglycidyl functionalized mesogenic core and without spacers has been cured with a diamine. The great affinity of LC epoxy to the formation of ordered structures introduces a spatial driving force into the process of curing. Thermal and LC behaviors were investigated by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The nature of the LC phases was confirmed by X-ray diffraction. Rheological experiments were conducted during crosslinking at different shear stresses. The viscosity of the mixture is strongly decreasing by three orders of magnitude when the solid epoxy is melting into a LC phase, and is increasing again due to the curing. Unexpected results were found. Applying a stress during curing had a profound influence on the ordering of the structure. The material becomes isotropic if a small shear stress is applied. Then, the higher the stress is, more ordered the final material is. For the highest stresses, the final material is in a highly ordered, quasi-crystalline, smectic structure
Towards communication-efficient quantum oblivious key distribution

Symmetrically private information retrieval, a fundamental problem in the field of secure multiparty computation, is defined as follows: A database D of N bits held by Bob is queried by a user Alice who is interested in the bit Db in such a way that (1) Alice learns Db and only Db and (2) Bob does not learn anything about Alice's choice b. While solutions to this problem in the classical domain rely largely on unproven computational complexity theoretic assumptions, it is also known that perfect solutions that guarantee both database and user privacy are impossible in the quantum domain. Jakobi et al. [Phys. Rev. A 83, 022301 (2011)] proposed a protocol for oblivious transfer using well-known quantum key device (QKD) techniques to establish an oblivious key to solve this problem. Their solution provided a good degree of database and user privacy (using physical principles like the impossibility of perfectly distinguishing nonorthogonal quantum states and the impossibility of superluminal communication) while being loss-resistant and implementable with commercial QKD devices (due to the use of the Scarani-Acin-Ribordy-Gisin 2004 protocol). However, their quantum oblivious key distribution (QOKD) protocol requires a communication complexity of O(NlogN). Since modern databases can be extremely large, it is important to reduce this communication as much as possible. In this paper, we first suggest a modification of their protocol wherein the number of qubits that need to be exchanged is reduced to O(N). A subsequent generalization reduces the quantum communication complexity even further in such a way that only a few hundred qubits are needed to be transferred even for very large databases
Secondary metabolites of Bagassa guianensis Aubl. wood: A study of the chemotaxonomy of the Moraceae family

International audienceIn order to explain the durability of the Moraceae plant family, phytochemistry of Bagassa guianensis was performed. Ethyl acetate extract was obtained from the heartwood and 18 secondary metabolites were isolated, including 6 moracins [6-O-methyl-moracin M, 6-O-methyl-moracin N and moracin Z; previously identified: moracin M, moracin N and moracin P], 8 stilbenoids [presently identified: ( )-epialboctalol and arachidin 4; previously identified: alboctalol, trans-resveratrol, arachidin 2, trans-oxyresveratrol and artogomezianol], 3 previously identified flavonoids, steppogenin, katuranin and dihydromorin, bsitosterol and resorcinol. Previous studies suggest that stilbenoids are responsible for the natural durability of wood. Our study has determined that B. guianensis is closely related to Morus sp. in phylogeny and should be included in the Moreae sensu stricto tribe of the Moraceae family
Energy Accounting and Control with SLURM Resource and Job Management System

International audienceEnergy consumption has gradually become a very important parameter in High Performance Computing platforms. The Resource and Job Management System (RJMS) is the HPC middleware that is responsible for distributing computing power to applications and has knowledge of both the underlying resources and jobs needs. Therefore it is the best candidate for monitoring and controlling the energy consumption of the computations according to the job specifications. The integration of energy measurment mechanisms on RJMS and the consideration of energy consumption as a new characteristic in accounting seemed primordial at this time when energy has become a bottleneck to scalability. Since Power-Meters would be too expensive, other existing measurement models such as IPMI and RAPL can be exploited by the RJMS in order to track energy consumption and enhance the monitoring of the executions with energy considerations. In this paper we present the design and implementation of a new framework, developed upon SLURM Resource and Job Management System, which allows energy accounting per job with power profiling capabilities along with parameters for energy control features based on static frequency scaling of the CPUs. Since the goal of this work is the deployment of the framework on large petaflopic clusters such as CURIE, its cost and reliability are important issues. We evaluate the overhead of the design choices and the precision of the monitoring modes using different HPC benchmarks (Linpack, IMB, Stream) on a real-scale platform with integrated Power-meters. Our experiments show that the overhead is less than 0.6% in energy consumption and less than 0.2% in execution time while the error deviation compared to Power-meters less than 2% in most cases
Decadal variability of sea surface temperatures off North Iceland over the last 2000 years

International audienceOcean variability at decadal time-scales remains poorly described partly because of the scarcity of high temporal resolution marine records. Here, we present a reconstruction of Sea Surface Temperatures (SSTs) over the past twomillennia at unprecedented temporal resolution (2 to 5 years), from a marine core located off North Iceland. Alkenone paleothermometry was used to infer SST variability, and tephrochronology to build the age model. Spectral analyses of the SSTsignal indicate intermittent 20–25 year oscillations, with periods of strong and weak power, that are likely reflecting the ocean response to wind forcing, presumably the North Atlantic Oscillation (NAO). Warmer SSTs and paleo-magnetic proxy data, between 1000 and 1350 year A.D., overlapping theMedievalWarm Period (MWP), suggest enhanced heat transport across the Denmark Strait by the North Icelandic IrmingerCurrent (NIIC). This is in contrast with the subsequent period, which includes the Little IceAge (LIA), showing continuous cooling towards the 20th century.Reduced NIIC flow through theDenmark Strait likely resulting from higher freshwater and sea ice export from the Arctic would account for the observed colder conditions
Testing the survival of microfossils in artificial martian sedimentary meteorites during entry into Earth's atmosphere: the STONE 6 experiment

International audienceIf life ever appeared on Mars, could we find traces of primitive life embedded in sedimentary meteorites? To answer this question, a 3.5 billion-year-old volcanic sediment containing microfossils was embedded in the heat shield of a space capsule in order to test survival of the rock and the microfossils during entry into the Earth's atmosphere (the STONE 6 experiment). The silicified volcanic sediment from the Kitty's Gap Chert (Pilbara, Australia) is considered to be an excellent analogue for Noachian-age volcanic sediments. The microfossils in the chert are also analogues for potential martian life. An additional goal was to investigate the survival of living microorganisms (Chroococcidiopsis) protected by a 2 cm thick layer of rock in order to test whether living endolithic organisms could survive atmospheric entry when protected by a rocky coating. Mineralogical alteration of the sediment due to shock heating was manifested by the formation of a fusion crust, cracks in the chert due to prograde and retrograde changes of α quartz to β quartz, increase in the size of the fluid inclusions, and dewatering of the hydromuscovite-replaced volcanic protoliths. The carbonaceous microfossils embedded in the chert matrix survived in the rock away from the fusion crust but there was an increase in the maturity index of the kerogen towards the crust. We conclude that this kind of sediment can survive atmospheric entry and, if it contains microfossils, they could also survive. The living microorganisms were, however, completely carbonised by flame leakage to the back of the sample and therefore non-viable. However, using an analytical model to estimate the temperature reached within the sample thickness, we conclude that, even without flame leakage, the living organisms probably need to be protected by at least 5 cm of rock in order to be shielded from the intense heat of entry
Sea spray geoengineering experiments in the geoengineering model intercomparison project (GeoMIP): Experimental design and preliminary results

International audienceMarine cloud brightening through sea spray injection has been proposed as a method of temporarily alleviating some of the impacts of anthropogenic climate change, as part of a set of technologies called geoengineering. We outline here a proposal for three coordinated climate modeling experiments to test aspects of sea spray geoengineering, to be conducted under the auspices of the Geoengineering Model Intercomparison Project (GeoMIP). The first, highly idealized, experiment (G1ocean-albedo) involves a uniform increase in ocean albedo to offset an instantaneous quadrupling of CO2 concentrations from preindustrial levels. Results from a single climate model show an increased land-sea temperature contrast, Arctic warming, and large shifts in annual mean precipitation patterns. The second experiment (G4cdnc) involves increasing cloud droplet number concentration in all low-level marine clouds to offset some of the radiative forcing of an RCP4.5 scenario. This experiment will test the robustness of models in simulating geographically heterogeneous radiative flux changes and their effects on climate. The third experiment (G4sea-salt) involves injection of sea spray aerosols into the marine boundary layer between 30°S and 30°N to offset 2 W m-2 of the effective radiative forcing of an RCP4.5 scenario. A single model study shows that the induced effective radiative forcing is largely confined to the latitudes in which injection occurs. In this single model simulation, the forcing due to aerosol-radiation interactions is stronger than the forcing due to aerosol-cloud interactions. Key Points Outline of three marine cloud brightening experiments Land-sea contrast is an important feature of marine cloud brightening Direct effect of sea salt injection may be greater than indirect effect ©2013. American Geophysical Union. All Rights Reserved
Use of poly(3-hexylthiophene)/poly(methyl methacrylate) (P3HT/PMMA) blends to improve the performance of water-gated organic field-effect transistors

International audiencePoly(3-hexylthiophene)/poly(methyl methacrylate) (P3HT/PMMA) blends were used as the semiconducting layer in water-gated organic field-effect transistors (OFETs), which resulted in improving the electrical performance of the previously reported devices with pure P3HT. Topographic investigations by atomic force microscopy carried out on blends with various PMMA to P3HT ratio reveal a lateral phase separation of the two components. All transistors operate at very low voltage (below 1 V), with a threshold voltage ranging form 0.3 to 0.5 V. An optimum of the composition of the blend is found with 70% of PMMA, leading to a maximum on/off current ratio and a mobility comparable to that of pure P3HT
Uniform and Ergodic Sampling in Unstructured Peer-to-Peer Systems with Malicious Nodes

ISBN: 978-3-642-17652-4International audienceWe consider the problem of uniform sampling in large scale open systems. Uniform sampling is a fundamental schema that guarantees that any individual in a population has the same probability to be selected as sample. An important issue that seriously hampers the feasibility of uniform sampling in open and large scale systems is the inevitable presence of malicious nodes. In this paper we show that restricting the number of requests that malicious nodes can issue and allowing for a full knowledge of the composition of the system is a necessary and sufficient condition to guarantee uniform and ergodic sampling. In a nutshell, a uniform and ergodic sampling guarantees that any node in the system is equally likely to appear as a sample at any non malicious node in the system and that infinitely often any nodes have a non null probability to appear as a sample at any honest nodes
Non injectivity of the q-deformed von Neumann algebra

We prove that the von Neumann algebra generated by q-gaussians is not injective as soon as the dimension of the underlying Hilbert space is greater than 1. Our approach is based on a vector valued Khintchine type inequality for Wick products. The same proof also works for the more general setting of a Yang-Baxter deformation. Our techniques can also be extended to the so called q-Araki-Woods von Neumann algebras recently introduced by Hiai. In this latter case, we obtain the non injectivity under some asssumption on the spectral set of the positive operator associated with the deformation
Atomic layering and related postmelting effects in small liquid metal clusters

Producción CientíficaThe specific heat of Na_25, as obtained by first-principles molecular dynamics simulations, shows interesting
anomalies above the melting phase-change region:  a)  It steadily decreases with increasing temperature, an
effect observed also in bulk liquid metals. This trend is explained in terms of the gradual conversion of
vibrational modes into diffusion modes;  b)  on top of this decreasing trend, the specific heat shows broad
undulations, induced by the temperature-dependent atomic layering in the liquid cluster. Extended liquid metal
surfaces also show atomic layering, but it does not affect the bulk heat capacity. This effect is therefore genuine
of finite atomic systems and should be expected to be quite general in metal clusters
Characterization of Polyphosphoesters by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

FT-ICR mass spectrometry, together with collision-induced dissociation and electron capture dissociation, has been used to characterize the polyphosphoester poly[1,4-bis(hydroxyethyl)terephthalate-alt-ethyloxyphosphate] and its degradation products. Three degradation pathways were elucidated: hydrolysis of the phosphate–[1,4-bis(hydroxyethyl)terephthalate] bonds; hydrolysis of the phosphate–ethoxy bonds; and hydrolysis of the ethyl–terephthalate bonds. The dominant degradation reactions were those that involved the phosphate groups. This work constitutes the first application of mass spectrometry to the characterization of polyphosphoesters and demonstrates the suitability of high mass accuracy FT-ICR mass spectrometry, with CID and ECD, for the structural analysis of polyphosphoesters and their degradation products
Ca2+ Sensitivity of Synaptic Vesicle Dopamine, ?-Aminobutyric Acid, and Glutamate Transport Systems

The effect of Ca2+ on the uptake of neurotransmitters by synaptic vesicles was investigated in a synaptic vesicle enriched fraction isolated from sheep brain cortex. We observed that dopamine uptake, which is driven at expenses of the proton concentration gradient generated across the membrane by the H+-ATPase activity, is strongly inhibited (70%) by 500 µM Ca2+. Conversely, glutamate uptake, which essentially requires the electrical potential in the presence of low Cl- concentrations, is not affected by Ca2+, even when the proton concentration gradient greatly contributes for the proton electrochemical gradient. These observations were checked by adding Ca2+ to dopamine or glutamate loaded vesicles, which promoted dopamine release, whereas glutamate remained inside the vesicles. Furthermore, similar effects were obtained by adding 150 µM Zn2+ that, like Ca2+, dissipates the proton concentration gradient by exchanging with H+. With respect to ?-aminobutyric acid transport, which utilizes either the proton concentration gradient or the electrical potential as energy sources, we observed that Ca2+ or Zn2+ do not induce great alterations in the ?-aminobutyric acid accumulation by synaptic vesicles. These results clarify the nature of the energy source for accumulation of main neurotransmitters and suggest that stressing concentrations of Ca2+ or Zn2+ inhibit the proton concentration gradient-dependent neurotransmitter accumulation by inducing H+ pump uncoupling rather than by interacting with the neurotransmitter transporter molecules.http://dx.doi.org/10.1023/A:100768471696
Invasive plants and their escape from root herbivory: a worldwide comparison of the root-feeding nematode communities of the dune grass Ammophila arenaria in natural and introduced ranges

Invasive plants generally have fewer aboveground pathogens and viruses in their introduced range than in their natural range, and they also have fewer pathogens than do similar plant species native to the introduced range. However, although plant abundance is strongly controlled by root herbivores and soil pathogens, there is very little knowledge on how invasive plants escape from belowground enemies. We therefore investigated if the general pattern for aboveground pathogens also applies to root-feeding nematodes and used the natural foredune grass Ammophila arenariaas a model. In the late 1800s, the European A. arenariawas introduced into southeast Australia (Tasmania), New Zealand, South Africa, and the west coast of the USA to be used for sand stabilization. In most of these regions, it has become a threat to native vegetation, because its excessive capacity to stabilize wind-blown sand has changed the geomorphology of coastal dunes. In stable dunes of most introduced regions, A. arenaria is more abundant and persists longer than in stabilized dunes of the natural range. We collected soil and root samples and used additional literature data to quantify the taxon richness of root-feeding nematodes on A.?arenaria in its natural range and collected samples from the four major regions where it has been introduced. In most introduced regions A. arenaria did not have fewer root-feeding nematode taxa than the average number in its natural range, and native plant species did not have more nematode taxa than the introduced species. However, in the introduced range native plants had more feeding-specialist nematode taxa than A. arenaria and major feeding specialists (the sedentary endoparasitic cyst and root knot nematodes) were not found on A. arenaria in the southern hemisphere. We conclude that invasiveness of A. arenaria correlates with escape from feeding specialist nematodes, so that the pattern of escape from root-feeding nematodes is more alike escape from aboveground insect herbivores than escape from aboveground pathogens and viruses. In the natural range of A. arenaria, the number of specialist-feeding nematode taxa declines towards the margins. Growth experiments are needed to determine the relationship between nematode taxon diversity, abundance, and invasiveness of A. arenaria.http://dx.doi.org/10.1007/s10530-004-1196-
Dublin City University at CLEF 2006: Cross-Language Speech Retrieval (CL-SR) experiments

The Dublin City University participation in the CLEF\ud
2006 CL-SR task concentrated on exploring the combination of the multiple fields associated with the documents. This was based on use of the extended BM25F field combination model originally developed for multi-field text documents. Additionally, we again conducted runs with our existing information retrieval methods based on the Okapi model. This latter method required an approach to determining approximate sentence boundaries within the free-flowing automatic transcription provided, to enable us to use our summary-based pseudo relevance feedback (PRF). Experiments were conducted for the English document collection with topics translated into English using Systran V3.0 machine translation
Philosophical aspects of modern cosmology

This paper is a short introduction to a special issue on philosophy of cosmology, published in the May 2014 issue of Studies in History and Philosophy of Modern Physics. I briefly introduce the philosophy of cosmology, and then provide a short outline of the contents of the papers in the special issue. The contributors are George Ellis, Dominico Giulini, Marc Lachièze-Rey, Helge Kragh, Jeremy Butterfield, Jean-Christophe Hamilton, Martín López-Corredoira, Brigitte Falkenburg, Robert Brandenberger and Chris Smeenk.  I conclude with a few remarks on the relationship between aesthetics and cosmology
Ku Band transmitarray lens for microwave applications

In this document a microstrip constrained lens device for Ku band, for microwave purpose, is presented. This paper offers an overview of artificial lens-type devices and the proposed transmitarray lens is thoroughly studied in terms of design and manufacturing, with architecture discussion and selection, along with the design, manufacturing and validation of all the forming components of the transmitarray (transmission circuits, radiating elements, etc.). Each element is properly characterized and assembled properly in the complete transmitarray prototype. Eventually, radiation pattern measurements as well as gain and directivity values, are provided to show the proper behaviour of the proposed transmitarray lens
A semantical framework for hybrid knowledge bases

In the ongoing discussion about combining rules and ontologies on the Semantic Web a recurring issue is how to combine first-order classical logic with nonmonotonic rule languages. Whereas several modular approaches to define a combined semantics for such hybrid knowledge bases focus mainly on decidability issues, we tackle the matter from a more general point of view. In this paper, we show how Quantified Equilibrium Logic (QEL) can function as a unified framework which embraces classical logic as well as disjunctive logic programs under the (open) answer set semantics. In the proposed variant of QEL, we relax the unique names assumption, which was present in earlier versions of QEL. Moreover, we show that this framework elegantly captures the existing modular approaches for hybrid knowledge bases in a unified way
Mathematical analysis of a model of chemotaxis arising from morphogenesis

We consider non-negative solution of a chemotaxis system with non constant chemotaxis sensitivity function X. This system appears as a limit case of a model formorphogenesis proposed by Bollenbach et al. (Phys. Rev. E. 75, 2007).Under suitable boundary conditions, modeling the presence of a morphogen source at x=0, we prove the existence of a global and bounded weak solution using an approximation by problems where diffusion is introduced in the ordinary differential equation. Moreover,we prove the convergence of the solution to the unique steady state provided that ? is small and ? is large enough. Numerical simulations both illustrate these results and give rise to further conjectures on the solution behavior that go beyond the rigorously proved statements