pinecone/core-2020-05-10-deduplication huggingface dataset:
Reaction of the desulfoferrodoxin from Desulfoarculus baarsii with superoxide anion. Evidence for a superoxide reductase activity.

International audienceDesulfoferrodoxin is a small protein found in sulfate-reducing bacteria that contains two independent mononuclear iron centers, one ferric and one ferrous. Expression of desulfoferrodoxin from Desulfoarculus baarsii has been reported to functionally complement a superoxide dismutase deficient Escherichia coli strain. To elucidate by which mechanism desulfoferrodoxin could substitute for superoxide dismutase in E. coli, we have purified the recombinant protein and studied its reactivity toward O-(2). Desulfoferrodoxin exhibited only a weak superoxide dismutase activity (20 units mg(-1)) that could hardly account for its antioxidant properties. UV-visible and electron paramagnetic resonance spectroscopy studies revealed that the ferrous center of desulfoferrodoxin could specifically and efficiently reduce O-(2), with a rate constant of 6-7 x 10(8) M(-1) s(-1). In addition, we showed that membrane and cytoplasmic E. coli protein extracts, using NADH and NADPH as electron donors, could reduce the O-(2) oxidized form of desulfoferrodoxin. Taken together, these results strongly suggest that desulfoferrodoxin behaves as a superoxide reductase enzyme and thus provide new insights into the biological mechanisms designed for protection from oxidative stresses
Influence of oceanic factors on Anguilla anguilla (L.) over the twentieth century in coastal habitats of the Skagerrak, southern Norway

The European eel (Anguilla anguilla L.) is distributed all over Europe, but reproduction takes place in the Atlantic
Ocean, in the Sargasso Sea. The population has been undergoing a steady decline since the 1980s. The eel is considered as critically endangered on the IUCN (International Union for the Conservation of Nature and Natural Resources) Red List of species. The objective of this study was to study the variation in eel abundance over the 20th century and determine which environmental factors are involved in the changes.
This was done by analyzing data from the Skagerrak beach seine survey from Norway. This dataset constitutes the longest fishery-independent time series on eels (starting in 1904). Results showed that eel fluctuated according to changes in temperature in the Sargasso Sea and that warm temperatures had a negative effect on the number of eel larvae. The number of eels in the Skagerrak region was also dependant on current circulation in the North Sea
The marine myxosporean Sigmomyxa sphaerica (Thélohan, 1895) gen. n., comb. n. (syn. Myxidium sphaericum) from garfish (Belone belone (L.)) uses the polychaete Nereis pelagica L. as invertebrate host

Sigmomyxa sphaerica (Thélohan, 1892) gen. n. (Myxozoa, Myxosporea) with myxosporean stages in the gall bladder of Belone belone (L.) (Teleostei, Belonidae) uses the polychaete Nereis pelagica L. (Nereidae) from shallow water in the northern Øresund, Denmark, as invertebrate host. The nearly spherical tetractinomyxon-type actinospores of S. sphaerica differ from those of two species of Ellipsomyxa which also use Nereis spp. as invertebrate host. Pansporocysts of S. sphaerica were not seen. S. sphaerica is redescribed on the basis of myxospore stages from B. belone and actinospores from N. pelagica, and the phylogenetic affinities examined on the basis of ribosomal small subunit gene sequences. S. sphaerica is closest related to Ellipsomyxa spp., and is not congeneric with morphologically similar Myxidium spp. from gadids. This is the fifth elucidated two-host life cycle of a marine myxozoan
Striola magica. A functional explanation of otolith geometry

International audienceOtolith end organs of vertebrates sense linear accelerations of the head and gravitation. The hair cells on their epithelia are responsible for transduction. In mammals, the striola, parallel to the line where hair cells reverse their polarization, is a narrow region centered on a curve with curvature and torsion. It has been shown that the striolar region is functionally different from the rest, being involved in a phasic vestibular pathway. We propose a mathematical and computational model that explains the necessity of this amazing geometry for the striola to be able to carry out its function. Our hypothesis, related to the biophysics of the hair cells and to the physiology of their afferent neurons, is that striolar afferents collect information from several type I hair cells to detect the jerk in a large domain of acceleration directions. This predicts a mean number of two calyces for afferent neurons, as measured in rodents. The domain of acceleration directions sensed by our striolar model is compatible with the experimental results obtained on monkeys considering all afferents. Therefore, the main result of our study is that phasic and tonic vestibular afferents cover the same geometrical fields, but at different dynamical and frequency domains
Wide-band Simultaneous Observations of Pulsars: Disentangling Dispersion Measure and Profile Variations

20 Pages, 14 Figures, Accepted for publication in Astronomy & AstrophysicsInternational audienceDispersion in the interstellar medium is a well known phenomenon that follows a simple relationship, which has been used to predict the time delay of dispersed radio pulses since the late 1960s. We performed wide-band simultaneous observations of four pulsars with LOFAR (at 40-190 MHz), the 76-m Lovell Telescope (at 1400 MHz) and the Effelsberg 100-m Telescope (at 8000 MHz) to test the accuracy of the dispersion law over a broad frequency range. In this paper we present the results of these observations which show that the dispersion law is accurate to better than 1 part in 100000 across our observing band. We use this fact to constrain some of the properties of the ISM along the line-of-sight and use the lack of any aberration or retardation effects to determine upper limits on emission heights in the pulsar magnetosphere. We also discuss the effect of pulse profile evolution on our observations, and the implications that it could have for precision pulsar timing projects such as the detection of gravitational waves with pulsar timing arrays
Determinants of benzodiazepine use in a representative population of HIV infected individuals: the role of HIV status disclosure (ANRS-EN12-VESPA study)

International audienceObjective: HIV infection may result in stressful situations such as disclosure to others and could be a mediator between seropositivity status and psychiatric illness, depression or anxiety. Several results have shown that anxiolytic use (mainly benzodiazepines) is highly prevalent in HIV-infected individuals, but few studies have highlighted to what extent this use could be associated with HIV disclosure. Design: A national cross-sectional survey representative of people living with HIV and AIDS in France enrolled 2932 individuals in 102 French HIV hospital departments. Methods: Face-to-face interviews and self-administered questions collected information about patients' experience with HIV and HIV care, including use of psychotropic drugs, social support, stigma and disclosure of HIV status. We identified factors associated with regular BDZ use (i.e. more than once a week) using a weighted logistic regression model. Results: Regular BDZ use and anxiety symptoms were reported by 16% and 29% of the patients respectively. After multiple adjustment for known correlates of BDZ use and anxiety symptoms, individuals who had disclosed their HIV status to relatives or friends were found to be more likely (OR[95%CI]= 1.78 [1.02-3.09]) to regularly use BDZ. Conclusions: These results show both to what extent disclosure to others continues to be a stressful step in the course of HIV infection and that disclosure is something which could be identified by BDZ use. They also highlight the need for appropriate case management and psychiatric care to help patients manage the consequences of disclosure
Ultrasonic tomography of green wood using a non-parametric imaging algorithm with reflected waves

International audience• Ultrasonic computed tomography in reflection was used to assess the integrity of green wood. Qualitative reflectivity images were obtained from back-scattered measurements by reflection tomography, like ultrasound in medical applications.<br> • The reconstruction algorithm was designed using, in particular, a linear approximation of the forward problem (Born approximation) and based on the assumption that a transversal cross section of wood is isotropic. The experimental device was composed of only one rotating emitter–receiver transducer to record and compute the projections. In this specific case, a tomographic projection was directly associated with a recorded signal. The qualitative aspect of this imaging technique was validated by performing a numerical simulation and tested on a small diameter green wood (Picea abies) log. <br>• The images obtained were geometrically accurate considering the internal inclusions. It was, however, not possible in the simulation to differentiate the object shape from the background (coupling medium) because the reflectivity value associated with the object was too low. The image obtained with the spruce sample mainly showed the position of the bark as indicated by a very high contrast area. The proportion of transmitted energy was, however, sufficient to reconstruct the artificial inclusion within the sample
Detection of decametre-wavelength pulsed radio emission of 40 known pulsars

International audienceThe study of pulsars at the lowest radio frequencies observable from the ground (10-30 MHz) is complicated by strong interstellar (dispersion, scattering) and ionospheric (scintillation, refraction) propagation effects, as well as intense Galactic background noise and interference. However, it permits us to measure interstellar plasma parameters (the effects of which increase by a power of two to >4 times the wavelength), the spectrum and the pulse profile at low frequencies more accurately. Up to now, only ˜10 pulsars have been successfully detected at these frequencies. The recent upgrade of the receivers at the Ukrainian T-shaped Radio telescope, second modification (UTR-2) has increased its sensitivity and motivated a new search for pulsed radio emissions. In this work we carried out a survey of known pulsars with declination above -10°, period >0.1 s and dispersion measure (DM) < 30 pc cm-3, i.e. a sample of 74 sources. Our goal was either to detect pulsars not recorded before in the decametre range or to identify factors that prevent their detection. As a result, we have detected the radio emission of 40 pulsars, i.e. 55 per cent of the observed sample. For 30 of them, this was a first detection at these frequencies. Parameters of their average profiles have been calculated, including the intrinsic widening of the pulse (not due to interstellar scattering) with decreasing frequency. Furthermore, two pulsars beyond the selected DM (B0138+59 with DM ≈ 35 pc cm-3 and B0525+21 with DM ≈51 pc cm-3) were also detected. Our results indicate that there is still room to detect new transient and pulsed sources with low-frequency observations
SPI instrumental background characteristics

In its space environment the INTEGRAL observatory is subject to an intense irradiation by energetic cosmic-ray particles that leads, via nuclear interactions with the telescope and spacecraft materials, to an important background of false events. In this paper we present the characteristics of the instrumental background that is observed in the spectrometer SPI (SPectrometer of INTEGRAL). We explain the tuning that has been performed on the parameters of the anticoincidence system in order to optimise the telescope sensitivity over the full energy range. Temporal variations of the instrumental background are discussed and methods are proposed that allow for their modelling in first order
How to estimate the differential acceleration in a two-species atom interferometer to test the equivalence principle

International audienceWe propose a scheme for testing the weak equivalence principle (Universality of Free Fall) using an atom-interferometric measurement of the local differential acceleration between two atomic species with a large mass ratio as test masses. A apparatus in free fall can be used to track atomic free-fall trajectories over large distances. We show how the differential acceleration can be extracted from the interferometric signal using Bayesian statistical estimation, even in the case of a large mass and laser wavelength difference. We show that this statistical estimation method does not suffer from acceleration noise of the platform and does not require repeatable experimental conditions. We specialize our discussion to a dual potassium/rubidium interferometer and extend our protocol with other atomic mixtures. Finally, we discuss the performances of the UFF test developed for the free-fall (0-g) airplane in the ICE project (\verb"http://www.ice-space.fr"
Emission-lines calibrations of the Star Formation Rate from the Sloan Digital Sky Survey

International audienceOur goal is to study the existing star formation rate calibrations based on emission-line luminosities and to provide new ones. We use the SDSS data release DR4, which gives star formation rates and emission-line luminosities of more than 100000 star-forming galaxies. We confirm that the best results are obtained with the Halpha calibration. This calibration has an uncertainty of 0.17 dex. We show that one has to check carefully the method used to derive the dust attenuation and to use the adequate calibration: in some cases, the standard scaling law has to be replaced by a more general power law. When data is corrected for dust attenuation but the Halpha emission line not observed, the use of the Hbeta emission line, has to be preferred to the [OII]3727 emission line. In the case of uncorrected data, the correction for dust attenuation can be assumed as a constant value but we show that such method leads to poor results, in terms of dispersion and residual slope. Self-consistent corrections, based e.g. on the absolute magnitude, give better results in terms of dispersion but still suffer from systematic shifts, and/or residual slopes. The best results with data not corrected for dust attenuation are obtained when using the observed [OII]3727 and Hbeta emission lines together. This calibration has an uncertainty of 0.23 dex
Growth of stylolite teeth patterns depends on normal stress and finite compaction

International audienceStylolites are spectacular rough dissolution surfaces that are found in many rock types. Despite many studies, their genesis is still debated, particularly the time scales of their formation and the relationship between this time and their morphology. We developed a new discrete simulation technique to explore the dynamic growth of the stylolite roughness, starting from an initially flat dissolution surface. We demonstrate that the typical steep stylolite teeth geometry can accurately be modelled and reproduce natural patterns. The growth of the roughness takes place in two successive time regimes: i) an initial non-linear increase in roughness amplitude that follows a power-law in time up to ii) a critical time where the roughness amplitude saturates and stays constant
Microfluidic separation of magnetic nanoparticles on an ordered array of magnetized micro-pillars

International audienceMicrofluidic separation of magnetic particles is based on their capture by magnetized micro-collectors while the suspending fluid flows past micro-collectors inside a micro-channel. Separation of nanoparticles is often challenging because of strong Brownian motion. Low capture efficiency of nanoparticles limits their applications in bio-analysis. However, at some conditions, magnetic nanoparticles may undergo field-induced aggregation that amplifies the magnetic attractive force proportionally to the aggregate volume and considerably increases nanoparticle capture efficiency. In this paper, we have demonstrated the role of such aggregation on an efficient capture of magnetic nanoparticles (about 80 nm in diameter) in a microfluidic channel equipped with a nickel micro-pillar array. This array was magnetized by an external uniform magnetic field, of intensity as low as 6-10 kA/m, and experiments were carried out at flow rates ranging between 0.3-30 µL/min. Nanoparticle capture is shown to be mostly governed by Mason number Ma, while the dipolar coupling parameter α does not exhibit a clear effect in the studied range, 1.4 < α < 4.5. The capture efficiency Λ shows a strongly decreasing Mason number behavior, Λ∝Ma-1.78 within the range, 32 ≤ Ma ≤ 3250. We have proposed a simple theoretical model, which considers destructible nanoparticles chains and gives the scaling behavior, Λ∝Ma-1.7 , close to the experimental findings
EPICURE: A partitioning and co-design framework for reconfigurable computing

This paper presents a new design methodology able to bridge the gap between an abstract specification and a heterogeneous reconfigurable architecture. The EPICURE contribution is the result of a joint study on abstraction/refinement methods and a smart reconfigurable architecture within the formal Esterel design tools suite. The original points of this work are: (i) a generic HW/SW interface model, (ii) a specification methodology that handles the control, and includes efficient verification and HW/SW synthesis capabilities, (iii) a method for parallelism exploration based on abstract resources/performance estimation expressed in terms of area/delay tradeoffs, (iv) a HW/SW partitioning approach that refines the specification into explicit HW configurations and the associated SW control. The EPICURE framework shows how a cooperation of complementary methodologies and CAD tools associated with a relevant architecture can signficantly improve the designer productivity, especially in the context of reconfigurable architectures
Coordinating cross-border congestion management through auctions: An experimental approach to European solutions

International audienceCompetition among producers within an integrated electricity system is impeded by any limited transmission capacity there may be at its borders. Two alternative market mechanisms have recently been designed to organize the allocation of scarce transmission capacity at cross-border level: (i) the "implicit auction", already used in some countries, and (ii) the "coordinated explicit auction", proposed by the European Transmission System Operators (ETSO) but not implemented yet. The main advantage of the explicit auction is that it allows each country to keep its own power exchange running. In the European institutional context, this is seen as a factor of success of a market reform, although the explicit auction (not coordinated) is known to be less efficient than the implicit mechanism. The addition of a coordination dimension in the explicit auction is intended to solve problems of international flows. We use an experimental methodology to identify and compare in a laboratory setting the efficiency properties of these two market mechanisms, given a market structure similar to the existing one in continental Europe, i.e. a competitive oligopoly. Our main result highlights the inefficiency of the coordinated explicit auction compared to the performance of the implicit auction, measured in terms of both energy prices and transmission capacity allocation. We suggest that the poor performance of the coordinated explicit auction in the laboratory is due to the level of individual expectations about both energy and transmission prices that the mechanism demands. One solution to resolve this problem when the mechanism is implemented in the field would be to design an additional and secondary market for "used" transmission capacity
2-Substituted vs 4-substituted-9,9′-spirobifluorene host materials for green and blue phosphorescent OLEDs: a structure-property relationship study

Nanotek for organic synthesis, and organic synthesis for nanotekInternational audienceWe report a structure-property relationship study of four 9,9′-spirobifluorene (SBF) derivatives (4-5Pm-SBF, 2-5Pm-SBF, 4-Ph-SBF and 2-Ph-SBF), substituted with either phenyl or pyrimidine at the \C2\ or \C4\ position of the \SBF\ core. Structural, thermal, electrochemical and photophysical properties have been examined and correlated to theoretical calculations in order to study the influence of the nature and the position of the substituent. The emission properties of 4- versus 2-substituted \SBFs\ are noticeably different highlighting, in the excited state, the remarkable effect of substitution in ortho position of SBF. All compounds have been used as host material for green dopant in PhOLEDs with very high performances (2-5Pm-SBF: CE>58 cd/A, PE>35 lm/W, EQE>14%). More importantly, the two 4-substituted \SBFs\ have been used as host materials in blue PhOLEDs, displaying high performance and a decrease of \VTH\ for 4-5Pm-SBF due to the incorporation of the electron-withdrawing pyrimidine
Multiaxial fatigue models for short glass fiber reinforced polyamide - Part I: Nonlinear anisotropic constitutive behavior for cyclic response

WOSInternational audienceComponents made of short glass fiber reinforced (SGFR) thermoplastics are increasingly used in the automotive industry, and more frequently subjected to fatigue loadings during their service life. The determination of a predictive fatigue criterion is therefore a serious issue for the designers, and requires the knowledge of the local mechanical response under a large range of environmental conditions (temperature and relative humidity). As the cyclic behavior of polymeric material is reckoned to be highly nonlinear, even at room temperature, an accurate constitutive model is a preliminary step for confident fatigue design. The injection molding process induces a complex fiber orientation distribution (FOD), which affects both the mechanical response and the fatigue life of SGFR thermoplastics. This paper presents an extension of the constitutive behavior proposed by the authors in a previous work [Launay et al., Int J Plasticity, 2011], in order to take into account the influence of the local FOD on overall anisotropic elastic and viscoplastic properties. The proposed model is written in a general 3D anisotropic framework, and is validated on tensile samples with various FOD and loading histories: monotonic tensions, creep and/or relaxation steps, cyclic loadings. In Part II of this paper [Launay et al., Int J Fatigue, 2012], this constitutive model will be applied to the simulation of different fatigue samples subjected to multiaxial cyclic loadings
Simulation of Laser Beam Propagation With a Paraxial Model in a Tilted Frame

International audienceWe study the Schrödinger equation which comes from the paraxial approximation of the Helmholtz equation in the case where the direction of propagation is tilted with respect to the boundary of the domain. In a first part, a mathematical analysis is made which leads to an analytical formula of the solution in the simple case where the refraction index and the absorption coefficients are constant. Afterwards, we propose a numerical method for solving the initial problem which uses the previous analytical expression. Numerical results are presented. We also sketch an extension to a time dependant model which is relevant for laser plasma interaction