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This paper aims to provide the elemental composition of particles found in natural gas. Particle sampling is performed on cellulose filters obtained from an industrial gas storage facility, and the qualitative particle composition is determined by scanning electron microscopy and energy dispersive X-ray spectroscopy. Our results establish that natural gas may contain solid particles, with sizes ranging from less than 1 μm to more than 50 μm. The observed particles are composed of numerous elements, such as aluminum (Al), silica (Si), sulphur (S), chloride (Cl), chromium (Cr), zinc (Zn), sodium (Na), manganese (Mg), calcium (Ca), iron (Fe), titanium (Ti), nickel (Ni), vanadium (V), potassium (K), copper (Cu), manganese (Mn), silver (Ag), cobalt (Co), iodine (I), and barium (Ba), with relative occurrences ranging from 1 to 85%. Moreover, metallic elements enable the formation of larger particles as a result of the agglomeration of smaller particles.

Abstract The dihydrogen (H2) sector is undergoing development and will require massive storage solutions. To minimize costs, the conversion of underground geological storage sites, such as deep aquifers, used for natural gas storage into future underground hydrogen storage sites is the favored scenario. However, these sites contain microorganisms capable of consuming H2, mainly sulfate reducers and methanogens. Methanogenesis is, therefore expected but its intensity must be evaluated. Here, in a deep aquifer used for underground geological storage, 17 sites were sampled, with low sulfate concentrations ranging from 21.9 to 197.8 µM and a slow renewal of formation water. H2-selected communities mainly were composed of the families Methanobacteriaceae and Methanothermobacteriaceae and the genera Desulfovibrio, Thermodesulfovibrio, and Desulforamulus. Experiments were done under different conditions, and sulfate reduction, as well as methanogenesis, were demonstrated in the presence of a H2 or H2/CO2 (80/20) gas phase, with or without calcite/site rock. These metabolisms led to an increase in pH up to 10.2 under certain conditions (without CO2). The results suggest competition for CO2 between lithoautotrophs and carbonate mineral precipitation, which could limit microbial H2 consumption. Effects of H2 and CO2 on microbial communities in deep aquifers used as geological gas storage: microbiology and tomorrow’s energy mix.

Acquisitions of the Sentinel-1 satellite are processed and comprehensively analyzed to investigate the ground displacement during a three-year period above a double gas storage site (Lussagnet and Izaute) in Southwestern France. Despite quite low vertical displacements (between 4 and 8 mm) compared to the noise level, the cyclic motion reflects the seasonal variations due to charge and discharge during summer and winter periods, respectively. We can simulate the ground deformation at both storage sites by a simple mechanical model. However, ground movements of low-magnitude may be also induced by natural factors, such as the temperature or the soil moisture. Using a wavelet-based analysis, we show there is a soil expansion in the Lussagnet zone that contrasts both in phase and period with the seasonal deformation and that is linked to the surface soil moisture measured by the SMOS satellite. This other displacement is consistent with the water infiltration in the unsaturated zone followed by the swelling of a clay layer. This work reveals the combination of two different processes driving the ground displacement with the same order of magnitude (about 6 mm), namely the pressure variation of a deep gas reservoir and the swelling/shrinking of the shallow subsurface.

L’aventure spatiale française s’est construite grâce à une jeunesse passionnée qui a fait du rêve une réalité. À l’heure où la Chine relance une course qui s’était essoufflée, la France saura-t-elle renouveler l’exploit ?

The deterioration of sleep in the older population is a prevalent feature that contributes to a decrease in quality of life. Inappropriate entrainment of the circadian clock by light is considered to contribute to the alteration of sleep structure and circadian rhythms in the elderly. The present study investigates the effects of aging on non-visual spectral sensitivity to light and tests the hypothesis that circadian disturbances are related to a decreased light transmittance. In a within-subject design, eight aged and five young subjects were exposed at night to 60 minute monochromatic light stimulations at 9 different wavelengths (420-620 nm). Individual sensitivity spectra were derived from measures of melatonin suppression. Lens density was assessed using a validated psychophysical technique. Although lens transmittance was decreased for short wavelength light in the older participants, melatonin suppression was not reduced. Peak of non-visual sensitivity was, however, shifted to longer wavelengths in the aged participants (494 nm) compared to young (484 nm). Our results indicate that increased lens filtering does not necessarily lead to a decreased non-visual sensitivity to light. The lack of age-related decrease in non-visual sensitivity to light may involve as yet undefined adaptive mechanisms.

Given a dataset with many features observed in a large number of conditions, it is desirable to fuse and aggregate conditions that are similar to ease the interpretation and extract the main characteristics of the data. This article presents a multidimensional fusion penalty framework to address this question when the number of conditions are large. If the fusion penalty is encoded by an ℓ q -norm, we prove for uniform weights that the path of solutions is a tree that is suitable for interpretability. For the ℓ 1 and ℓ ∞ -norms, the path is piecewise linear and we derive a homotopy algorithm to recover exactly the whole tree structure. For weighted ℓ 1 -fusion penalties, we demonstrate that distance-decreasing weights lead to balanced tree structures. For a subclass of these weights that we call \"exponentially adaptive,\" we derive an homotopy algorithm and we prove an asymptotic oracle property. This guarantees that we recover the underlying structure of the data efficiently both from a statistical and a computational point of view. We provide a fast implementation of the homotopy algorithm for the single feature case, as well as an efficient embedded cross-validation procedure that takes advantage of the tree structure of the path of solutions. Our proposal outperforms its competing procedures on simulations both in terms of timings and prediction accuracy. As an example we consider phenotypic data: given one or several traits, we reconstruct a balanced tree structure and assess its agreement with the known taxonomy. Supplementary materials for this article are available online.

PurposeEvaluate short-term intraoperator reproducibility of ultrasonographic measurements of choroidal nevi using 10- and 20-MHz probes, and the efficacy of the high-frequency probes for the diagnosis of choroidal nevi.MethodsDiameters and thicknesses of choroidal nevi were measured using a 10-MHz probe and a high-frequency long focal length 20-MHz probe (Quantel Medical™). The first part of the study evaluated intraoperator reproducibility of measurements of choroidal nevi with 10- and 20-MHz probes and the second part of the study allowed the comparisons of the measurements of largest tumor diameter (LDT) of choroidal nevi of 40 patients between the 10- and 20-MHz probes. The two-way random average agreement intraclass correlation coefficients (ICC), Bland-Altman plot, and a paired t test were used.ResultsThe intraoperator reproducibility of choroidal nevi measurements with 10- and 20-MHz probes was excellent (ICC > 0.9, n = 20). Four flat nevi, not detectable at 10 MHz, could be located with the high-frequency probe (p = 0.12). There was no significant difference in thickness or LTD measurements between the 10- and 20-MHz probes (n = 31). Both techniques showed an excellent agreement (ICC > 0.8) for thickness and LTD measurements. All the choroidal nevi that were not measurable with the 10-MHz probe (n = 7) were measured with the 20-MHz probe.ConclusionThe high-frequency 20-MHz probe allows additional detection and measurements of flat choroidal nevi. When detectable, the ultrasonographic measurements of thickness and diameter of choroidal nevi are similar with both the 10- and the 20-MHz probes.

The increasing availability of expressed sequence tags (ESTs) in wheat (Triticum aestivum) and related cereals provides a valuable resource of non-anonymous DNA molecular markers. We examined 170,746 wheat ESTs from the public (International Triticeae EST Cooperative) and Genoplante databases, previously clustered in contigs, for the presence of di- to hexanucleotide simple sequence repeats (SSRs). Analysis of 46,510 contigs identified 3,530 SSRs, which represented 7.5% of the total number of contigs. Only 74% of the sequences allowed primer pairs to be designed, 70% led to an amplification product, mainly of a high quality (68%), and 53% exhibited polymorphism for at least one cultivar among the eight tested. Even though dinucleotide SSRs were less represented than trinucleotide SSRs (15.5% versus 66.5%, respectively), the former showed a much higher polymorphism level (83% versus 46%). The effect of the number and type of repeats is also discussed. The development of new EST-SSRs markers will have important implications for the genetic analysis and exploitation of the genetic resources of wheat and related species and will provide a more direct estimate of functional diversity.

AimsTo compare effectiveness of subconjunctival triamcinolone acetonide injections and intravitreal injections of dexamethasone 700 µg implants in reducing central macular thickness (CMT) in uveitic and postoperative macular oedema (ME).MethodsWe conducted an open-label, French multicentre randomised comparative trial with a logarithmic CMT non-inferiority margin set at 0.06. Patients were adults with non-infectious inflammatory ME, without any contraindication to the treatments. They were randomised 1:1 to receive either triamcinolone or dexamethasone. The primary endpoint was the difference in CMT among treated eyes between baseline and 2 months, measured with spectral-domain optical coherence tomography. Secondary outcomes included visual acuity, laser flare, vitreous haze, duration of action, tolerance to injections and adverse events.ResultsBetween January 2016 and January 2020, 106 patients were enrolled (54 in the triamcinolone group and 52 in the dexamethasone group). Subconjunctival triamcinolone injections seemed to be non-inferior to intravitreal dexamethasone injections, especially at month 3 (and nearly at month 1). Nevertheless, we could not demonstrate it, with a treatment effect at month 2 of 0.05 (0.01 ; 0.09) (p value=0.001). This was corroborated by post hoc analyses in the postoperative subgroup, for whom the non-inferiority was nearly demonstrated at month 2 with a treatment effect of 0.02 (−0.03 ; 0.08) (p=0.37). There was no significant difference in the occurrence of adverse effects.ConclusionWe could not demonstrate the non-inferiority of triamcinolone injections at month 2. Nevertheless, they showed some efficacity, particularly in treating postoperative ME, being as safe as dexamethasone injections, without any loss of chance if a therapeutic switch is necessary.