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International audience; In this work, we consider a mathematical model of syntrophic relationship between two microbial species of the anaerobic digestion process including mortality (or decay) terms. We focus on the acetogenesis and hydrogenotrophic methanogenesis phases. Our study gives a quite comprehensive analysis of a syntrophic model by analyzing the joined effects of syntrophy relationship, mortality, substrate inhibition and input concentrations that were neglected in previous studies. Using a general class of growth rates, the necessary and sufficient conditions of existence and local stability of all steady states of the four-dimensional system are determined according to the operating parameters. This general model exhibits a rich behavior with the coexistence of two microbial species, the bi-stability, the multiplicity of coexistence steady states, and the existence of two steady states of extinction of the first species. The operating diagram shows how the model behaves by varying the control parameters and illustrates the effect of the inhibition and the new input substrate concentration (hydrogen) on the reduction of the coexistence region and the emergence of a bi-stability region. Similarly to the classical chemostat model, including the substrate inhibition can destabilize a two-tiered microbial 'food chain' where the stability depends on the initial condition.

Bone is a biological tissue characterized by its hierarchical organization. This material has the ability to be continually renewed, which makes it highly adaptative to external loadings. Bone renewing is managed by a dynamic biological process called bone remodeling (BR), where continuous resorption of old bone and formation of new bone permits to change the bone composition and microstructure. Unfortunately, because of several factors, such as age, hormonal imbalance, and a variety of pathologies including cancer metastases, this process can be disturbed leading to various bone diseases. In this study, we have investigated the effect of breast cancer (BC) metastases causing osteolytic bone loss. BC has the ability to affect bone quantity in different ways in each of its primary and secondary stages. Based on a BR mathematical model, we modeled the BC cells' interaction with bone cells to assess their effect on bone volume fraction (BV/TV) evolution during the remodeling process. Some of the parameters used in our model have been determined experimentally using the enzyme-linked immune-sorbent assay (ELISA) and the MTT assay. Our numerical simulations show that primary BC plays a significant role in enhancing bone-forming cells' activity leading to a 6.22% increase in BV/TV over 1 year. On the other hand, secondary BC causes a noticeable decrease in BV/TV reaching 15.74% over 2 years.

The algebra B of bicomplex numbers is viewed as a complexification of the Archimedean f-algebra of hyperbolic numbers D. This lattice-theoretic approach allows us to establish new properties of the so-called D-norms. In particular, we show that D-norms generate the same topology in B. We develop the D-trigonometric form of a bicomplex number which leads us to a geometric interpretation of the nth roots of a bicomplex number in terms of polyhedral tori. We use the concepts developed, in particular that of Riesz subnorm of a D-norm, to study the uniform convergence of the bicomplex zeta and gamma functions. The main result of this paper is the generalization to the bicomplex case of the Riemann functional equation and Euler's reflection formula., 23 pages, 1 figure. Submitted

International audience; This paper aims at presenting an energy management strategy (EMS) based upon optimal control theory for a battery–supercapacitor hybrid power system. The hybrid power system consists of a lithium-ion battery and a supercapacitor with associated bidirectional DC/DC converters. The proposed EMS aims at computing adaptive gains using the salp swarm algorithm and load following control technique to assign the power reference for both the supercapacitor and the battery while achieving optimal performance and stable voltage. The DC/DC converter model is derived utilizing the first-principles method and computes the required gains to achieve the desired power. The fact that the developed algorithm takes disturbances into account increases the power elements’ life expectancies and supplies the power system with the required power.

Formaldehyde has been widely observed in the icy mantle of interstellar grains. H2CO may be formed from successive hydrogenations of CO and may further contribute to the chemical complexity of the Interstellar medium (ISM) participating to heterogeneous reactions with colliding gas phase atoms. Within this context, Eley-Rideal and Langmuir-Hinshelwood rate constants of H2 formation on a formaldehyde doped amorphous water ice grain model of the ISM, were computed over a wide temperature range [15–2000 K]. We used classical molecular dynamics (MD) simulations to build the model of the H2CO doped ice surface. Then we studied theoretically by means of hybrid QM/MM ab initio and molecular mechanics methodology (ONIOM) H atoms abstraction from formaldehyde molecules and the H2 formation. Specifically, we investigate the reactivity of the gas phase H atom toward one formaldehyde molecule lying at one of the slab surfaces. The reaction path and the energetics are predicted, the mechanism is found to be exothermic by 14.89 kcal/mol and the barrier is 6.75 kcal/mol at the QM level CBS/DLPNO-CCSD(T)//ONIOM/aug-cc-pVTZ. We employ two approaches that take into account tunnelling and non-classical reflection effects by means of the Zero Curvature Tunnelling (ZCT), and the Small Curvature Tunnelling (SCT) which all provided comparable results to predict the kinetics of the reaction path. The rate constants show important quantum tunnelling effects at low temperatures when compared to rates obtained from the purely classical transition-state theory (TST) and from the canonical variational transition state theory (CVT). Corner cutting effects are highlighted in the SCT calculations by 4 to 5 orders of magnitude with respect to ZCT rate constants at low temperatures.

International audience; We derive conditional stability estimates for inverse scattering problems related to time harmonic magnetic Schrödinger equation. We prove logarithmic type estimates for retrieving the magnetic (up to a gradient) and electric potentials from near field or far field maps. Our approach combines techniques from similar results obtained in the literature for inhomogeneous inverse scattering problems based on the use of geometrical optics solutions.

International audience; Haemogregarina species are apicomplexan blood parasites infecting vertebrates such as fish, lizards, and turtles. Due to the high morphological similarity of the erythrocytic stages infecting host species, it has always been a challenge to identify the true diversity of these parasites. Therefore, taxonomic studies are presently based on the combination of morphological and molecular data. In Tunisia, two species of Haemogregarina have been reported within the freshwater turtle Mauremys leprosa (Geoemydidae) for more than 40 years. Since M. leprosa occurs in the same aquatic environments as Emys orbicularis (Emydidae) in Tunisia, our objectives were to assess parasite diversity and specificity on the basis of both morphological and molecular approaches. The turtles were surveyed and sampled across six aquatic areas of Tunisia. Among the 39 specimens of M. leprosa and seven of E. orbicularis that were trapped and investigated, the presence of haemogregarines was detected in the blood of turtles only at sites where leeches were observed. Three 18S variants were identified, which corresponded to three distinct Haemogregarina species, among which one was identified as Haemogregarina stepanowi. The two other species that were detected are likely new to science. Because we show the occurrence of more than one blood parasite species within a single host specimen, our study provides the first report of coinfection with molecularly distinct Haemogregarina spp.

Query Expansion (QE) is widely applied to improve the retrieval performance of ad-hoc search, using different techniques and several data sources to find expansion terms. In Information Retrieval literature, selecting expansion terms remains a challenging task that relies on the extraction of term relationships. In this paper, we propose a new learning to rank-based query expansion model. The main idea behind is that, given a query and the set of its related ARs, our model ranks these ARs according to their relevance score regarding to this query and then selects the most suitable ones to be used in the QE process. Experiments are conducted on three test collections, namely: CLEF2003, TREC-Robust and TREC-Microblog, including long, hard and short queries. Results showed that the retrieval performance can be significantly improved when the ARs ranking method is used compared to other state of the art expansion models, especially for hard and long queries.

International audience; Crop diversity is shaped by biological and social processes interacting at different spatiotemporal scales. Here we combined population genetics and ethnobotany to investigate date palm (Phoenix dactylifera L.) diversity in Siwa Oasis, Egypt. Based on interviews with farmers and observation of practices in the field, we collected 149 date palms from Siwa Oasis and 27 uncultivated date palms from abandoned oases in the surrounding desert. Using genotyping data from 18 nuclear and plastid microsatellite loci, we confirmed that some named types each constitute a clonal line, i.e. a true-to-type cultivar. We also found that others are collections of clonal lines, i.e. ethnovarieties, or even unrelated samples, i.e. local categories. This alters current assessments of agrobiodiversity, which are visibly underestimated, and uncovers the impact of low-intensity, but highly effective, farming practices on biodiversity. These hardly observable practices, hypothesized by ethnographic survey and confirmed by genetic analysis, are enabled by the way Isiwans conceive and classify living beings in their oasis, which do not quite match the way biologists do: a classic disparity of etic vs. emic categorizations. In addition, we established that Siwa date palms represent a unique and highly diverse genetic cluster, rather than a subset of North African and Middle Eastern palm diversity. As previously shown, North African date palms display evidence of introgression by the wild relative Phoenix theophrasti Greuter, and we found that the uncultivated date palms from the abandoned oases share even more alleles with this species than cultivated palms in this region. The study of Siwa date palms could hence be a key to the understanding of date palm diversification in North Africa. Integration of ethnography and population genetics promoted the understanding of the interplay between diversity management in the oasis (short-time scale), and the origins and dynamic of diversity through domestication and diversification (long-time scale).; La diversité des plantes cultivées est façonnée par des processus biologiques et sociaux qui interagissent à différentes échelles spatiotemporelles. Nous avons ici combiné la génétique des populations et l’ethnobotanique pour étudier la diversité du palmier-dattier (Phoenix dactylifera L.) dans l’oasis de Siwa, en Égypte. Sur la base d’entretiens avec des agriculteurs et de l’observation des pratiques sur le terrain, nous avons collecté 149 palmiers dattiers de l’oasis de Siwa et 27 palmiers dattiers non cultivés provenant d’oasis abandonnées dans le désert environnant. En utilisant les données de génotypage de 18 loci microsatellites nucléaires et plastidiques, nous avons confirmé que certains types nommés constituent chacun une ligne clonale, c’est-à-dire un « cultivar vrai » (true-to-type). Nous avons également constaté que d’autres sont des collections de lignes clonales, c’est-à-dire des « ethnovariétés », voire même des échantillons non apparentés, c’est-à-dire des « catégories locales ». Cela modifie les évaluations existantes de l’agrobiodiversité, qui sont visiblement sous-estimées, et révèle l’impact des pratiques agricoles de faible intensité, mais très efficaces, sur la biodiversité. Ces pratiques difficilement observables, supposées par l’enquête ethnographique et confirmées par l’analyse génétique, sont rendues possibles par la façon dont les Isiwans conçoivent et classifient les êtres vivants dans leur oasis, qui ne correspond pas tout à fait à la façon dont les biologistes le font : une disparité classique des catégorisations étiques vs. émiques. En outre, nous avons établi que les palmiers dattiers de Siwa représentent un groupe génétique unique et très diversifié, plutôt qu’un sous-ensemble de la diversité des palmiers d’Afrique du Nord et du Moyen-Orient. Comme nous l’avons montré précédemment, les palmiers dattiers d’Afrique du Nord présentent des signes d’introgression par le parent sauvage Phoenix theophrasti Greuter, et nous avons constaté que les palmiers dattiers non cultivés des oasis abandonnées partagent encore plus d’allèles avec cette espèce que les palmiers cultivés de cette région. L’étude des palmiers dattiers de Siwa pourrait donc être une clé pour la compréhension de la diversification des palmiers dattiers en Afrique du Nord. L’intégration de l’ethnographie et de la génétique des populations a permis de comprendre l’interaction entre la gestion de la diversité dans l’oasis (l’échelle du court terme) et les origines et la dynamique de la diversité au travers de la domestication et de la diversification (l’échelle du long terme).

The present study aims to investigate the effect of copper (as CuSO4, 5H2O) supply (0, 25 and 50 μM) on performance of cilantro (Coriandrum sativum L.) plants grown under hydroponic conditions. All applied Cu concentrations drastically reduced the biomass production, length of the shoots and the roots and disturbed the ions (Cu, Ca, Fe, Zn and Mg) homeostasis. Either Cu-starvation (0 μM) or Cu-toxicity (25 and 50 μM) significantly reduced the net photosynthetic rate, stomatal conductance and transpiration rate resulting in reduced water use efficiency. Under Cu-toxicity, the variations in gas exchange parameters were associated with a remarkable decline in the photosynthetic pigments including Chlorophyll a, Chlorophyllb, Chlorophyll (a + b) and carotenoids. Additionally, an enhanced lipid peroxidation (evaluated as Malondialdehyde (MDA) contents) with a concomitant increase in proline, total soluble sugars and melanoidins contents were observed under these conditions. The increased MDA levels resulted in decrease in total lipid content and alteration of the fatty acid profiles in both shoots and roots with a general tendency toward the accumulation of saturated fatty acids that mirrors a decline in the desaturases activity. Although the increased activity of enzymatic antioxidants including catalase (CAT), gaiacol peroxidase (GPX) and ascorbate peroxidase (APX), the oxidative-induced injuries caused by 25 and 50 μM Cu were found to be irreversible and the optimal growth parameters were not achieved.

International audience; The behavior of potential prebiotic species in space is of main concern in the chemistry at the origin of life. Their reactivity or stability in spatial conditions, under strong UV radiations or ion bombardments, remains an open question and needs wide investigations. As protons are by far the most abundant ions in space, we focus presently on proton-induced collisions on imidazole and 2-aminoimidazole evidenced as important prebiotic RNA intermediates. Unconstrained full optimization of the structures was performed with B3LYP/cc-pVTZ model chemistry. The calculations were performed in a wide collision energy range in order to model various astrophysical environments, from eV in the interstellar medium, up to keV for solar winds or supernovae shock-wave protons. Such a study provides for the first time a theoretical insight on the influence of the amino substituent on the proton-induced charge transfer. We evaluated the role of icy grain environments through a cluster approach modeling the effect of a stepwise microhydration on the process. Comparisons with oxygenated and sulfurated analogues address further qualitative trends on the respective stability or reactivity of such heterocycles which may be of tremendous interest in prebiotic chemistry. Charge transfer appears to be quite efficient for imidazole compounds and their sulfurated analogue compared to the oxygenated heterocycle.

The structural parameters of the three most stable isomers with formula Cl2O2, dichlorine peroxide, chloryl chloride and chlorine chlorite, were determined by high-level ab initio theory. The effects of core-valence electronic correlation as well as relativistic corrections were included in the calculations, and vibrational averaging of the so-obtained structures was performed. The bond distances agree with experimental data, where available, to within 0.01 Å, an unprecedented accuracy in particular for the floppy dichlorine peroxide molecule. The UV spectra of the three molecules were computed and decay pathways investigated. Under actinic UV radiation at 248 nm dichlorine peroxide decomposes principally according to ClOOCl → 2Cl + O2, in a synchronous concerted mechanism. In the low-energy tail region of this signal, the decay proceeds in a non-synchronous manner. There is also a low probability of the decay channel towards ClOO + Cl, whereas ClO molecules were not found. Chloryl chloride absorbs strongly around 300 nm. It disintegrates into ClO2 + Cl, where ClO2 seems to be formed mainly in excited electronic states which decompose further into Cl + O2. Hence chloryl chloride, though much less abundant in the stratosphere than dichlorine peroxide, also contributes to ozone depletion.

Iodine oxide (IO) is an important tropospheric molecule. In the present paper, we mapped the potential energy surfaces (PESs) of the doubly degenerate IO(X-2 pi)-Ar van der Waals system using single- and double-excitation coupled cluster approaches with non-iterative perturbation treatment of triple excitations [RCCSD(T)] extrapolated to the complete basis set (CBS) limit. In addition to bent local minima, we identified a linear Ar-IO complex as a global minimum. Afterwards, we performed scattering calculations on these PESs, considering the non-zero spin-orbit contribution and the Renner-Teller effect. The integral cross-sections exhibit an oscillatory structure vs. the final rotational state, as already observed for the NO(X-2 pi)-Ar system. Moreover, computations reveal that the Ar-IO complex is stable toward dissociation into IO and Ar. Therefore, it can be found in the atmosphere and participates in iodine compound physical chemical processes occurring there.

In the Wireless Sensor Networks (WSNs), ensuring long-term survival of the sensor devices is crucial, especially for non-energy harvesting networks where the sensors have to deal with the available limited power. Thus, there is a huge need to efficiently select, in each time-slot, a small set of source nodes to monitor the network area and deliver their data to the sink. Note that there is a trade-off between energy efficiency, achieved through data-compression, and the informative quality received by the sink. Moreover, although applying a high data compression ratio extremely reduces the overall network energy consumption, the network lifetime is not necessarily extended due to the uneven energy depletion of the nodes' batteries. To this end, in this paper, we propose the Energy-Aware Matrix Completion based data gathering approach (EAMC), which designates the active nodes according to their residual energy levels. To collect data readings, the proposed EAMC relies on a nodes clustering phase and a MC based data sampling. Then, the interpolation of all the missing data is performed by the sink thanks to a Three-stage MC based recovery framework. Since we are interested in high data loss scenarios, the limited amount of delivered data must be sufficient in terms of informative quality it holds in order to reach a satisfactory recovery accuracy for the entire data. Hence, the EAMC selects the nodes depending on their inter-correlation as well as the network energy efficiency, with the use of a combined energy-aware and correlation-based metric. This introduced active node cost function changes with the type of application one wants to perform with the intention to reach a longer lifespan for the network. Therewith, the numerical results show that the EAMC achieves an attractive and competitive trade-off between the data reconstruction quality and the network lifetime for all the investigated scenarios.

BackgroundVariants in the Hepatocyte Nuclear Factor 1 Alpha gene (HNF1A) are associated with lipoproteins levels and type 2 diabetes. In this study, we aimed to assess the association ofHNF1Agene and haplotypes with the metabolic syndrome (MetS) and its components through an association study in the Tunisian population as well as by a meta-analysis.MethodsA total of 594 Tunisian individuals were genotyped for three variants (rs1169288, rs2464196 and rs735396) located inHNF1Agene using KASPar technology. Statistical analyses were performed with R software. The association was furthermore evaluated through a meta-analysis of our results with those obtained in a Moroccan population.ResultsOur results showed no association betweenHNF1Avariants and MetS in the Tunisian population. However, a significant association was observed between the variant rs735396 and a higher waist circumference. The stratified analysis according to the sex highlighted a significant association between the variant rs1169288 and high cholesterol levels only in women. Similarly, Haplotype analysis showed an association between theHNF1Aminor haplotype and high total cholesterol mainly in women. Finally, our meta-analysis showed no association betweenHNF1Avariants and MetS.ConclusionsOur findings exclude the involvement of the threeHNF1Avariants rs1169288, rs2464196 and rs735396 in the susceptibility to MetS in our studied Tunisian population but emphasize the role of these variants in the cholesterol homeostasis with sex-specific differences, which may serve to rise clinical consideration to early statin therapy in women carrying these genetic variants.

Leishmaniasis is a protozoal vector-borne disease that affects both humans and animals. In the Mediterranean Basin, the primary reservoir hosts of Leishmania spp. are mainly rodents and canids. Lipidomic approaches have allowed scientists to establish Leishmania spp. lipid profiles for the identification of cell stage specific biomarkers, drug mechanisms of action, and host immune response. Using an in silico approach of global network interaction between genes involved in fatty acid (FA) synthesis followed by the GC-MS approach, we were able to characterize the fatty acid profiles of L. major derived from human and rodent hosts. Our results revealed that the lipid profile of L. major showed similarities and differences with those already reported for other Leishmania species. Phospholipids are the predominant lipid class. FA composition of rodent parasites was characterized by a lower abundance of the precursor C18:2(n-6). One of the rodent clones, which also expressed the lowest lipid abundance in PL and TAG, was the least sensitive clone to the miltefosine drug and has the lowest infection efficiency. Our findings suggest that the lipid composition variation may explain the response of the parasite toward treatment and their ability to infect their host.

In this paper, the author examines the distortion of the past and the perversion of art in works of speculative dystopian fiction. Without history, there is no longer a past or a future; only the present persists as a perpetual replication of the same structures. In “1984”, everything is constantly rewritten in minute detail. In “Globalia”, the system wages a fierce war against history. Art is either recuperated or condemned to burn at the stake of state power (“Fahrenheit 451”). However, discovering art objects from past times and reading literary works signal a change of course which raises conscience and even leads to acts of resistance. In dystopian speculative literature, resistance acquires a symbolic dimension: Despite reigning darkness, there seems to appear a gleam of hope thanks to art and to literature.

We revisit the differential sampling method introduced in (Haddar and Nguyen 2017 Comput. Math. Appl. 74 2831–55) for the identification of a periodic domain and some local perturbation. We provide a theoretical justification of the method that avoids assuming that the local perturbation is also periodic. Our theoretical framework uses functional spaces with continuous dependence with respect to the Floquet–Bloch variable. The corner stone of the analysis is the justification of the generalized linear sampling method in this setting for a single Floquet–Bloch mode.

International audience; In the intelligent transportation system, many challenges have been identified to achieve a fully functional, practical and integrable ITS network. Some of these challenges include the regulation of traffic violations. Therefore, a proposed blockchain smart contract-based method has been formulated to address this challenge. This method includes vehicle speed detection, vehicle information collection through vehicle re-identification technique and a blockchain part containing smart contracts. The smart contract is a conditioned filter that follows regulatory rules from reporting violation points and fines for each violation to penalties. We have implemented the proposed algorithm and presented an evaluation of the proposed method, which gives satisfactory results and finally compare it with other known methods.

The algebra D of hyperbolic numbers is endowed with its standard f-algebra structure [7]. We introduce the ring of hyperbolic integers Z h as a sub f-ring of Z D the ring of integers of D. We prove that Z h is the unique, up to ring isomorphism, Archimedean f-ring of quadratic integers. Our study focuses on arithmetic properties of Z h related to its lattice-ordered structure. We show that many of basic properties of the ring of integers Z such as primes, unique factorization theorem and the notions of floor and ceiling functions can be extended to Z h. In particular, Some properties of the hyperbolic Gaussian integers are obtained. As an application, we discuss the Dirichlet divisor problem using hyperbolic intervals and introduce the notion of toroidal groups.

International audience; Understanding stream runoff generation processes requires distributed stream runoff estimates; however the acquisition of such estimates remains challenging in hydrology, especially in remote areas. In regions with a high spatial density of small reservoirs, those reservoirs could be employed to gauge stream runoff (Liebe et al., 2009). Using a water balance approach, the stream runoff flowing into a reservoir from a drainage catchment could be estimated. Accordingly, this work aims to address the following two questions: i) what is the error in the estimated stream runoff and ii) what are the main estimation uncertainty factors? Based on a case study of the Kamech catchment, Tunisia, stream runoff was estimated at different temporal resolutions (1–32 days), and a global sensitivity analysis was performed to estimate the contributions of the reservoir water balance terms (evaporation, rainfall, percolation, reservoir water level and level-area-volume relations) to the estimated stream runoff uncertainty.The results reveal that stream runoff can be reliably estimated based on small reservoirs using a mass balance approach. The error and global stream runoff estimation uncertainties decrease as the temporal resolution increases. The bathymetric relationships (level-area and level-volume relations) constitute a strong factor of uncertainty for all temporal resolutions, and even the dominant factor for temporal resolutions ranging from 4 to 23 days. The estimation uncertainty for the shortest temporal resolutions (1–8 days) mainly originates from reservoir level uncertainty. As the temporal resolution increases, the contribution of percolation uncertainty increases. The general (not site-specific) conclusions of this study are that stream runoff gauging based on small reservoirs requires the determination of the bathymetric relations and that small reservoirs could be used as reliable stream runoff gauges at short temporal resolutions if the reservoir level is measured with limited uncertainty and at long temporal resolutions as long as the percolation rate from the reservoir is known with limited uncertainty

In this paper, we consider an inverse problem of determining two space dependent ionic parameters of a strongly coupled parabolic-elliptic reaction–diffusion system arising in cardiac electrophysiology modeling when simulating drugs action with multi-electrode array/human induced pluripotent stem cells-cardiomyocytes assays. We use the bidomain model coupled to an ordinary differential equation and we consider the classical phenomenological model in cardiac electrophysiology of FitzHugh–Nagumo to describe the ionic exchanges at the microscopic level. Our main result is the uniqueness and a Lipschitz stability estimate for two ionic parameters ( k , γ ) of the model using sub-boundary observations over an interval of time. The key ingredients are a global Carleman-type estimates with a suitable observations acting on a part of the boundary.

International audience; Photoelectrochemical (PEC) water splitting has drawn great attention of scientists as an appreciated approach for converting solar energy into renewable fuels. So far, semiconductor-based photoanodes are considered as promising candidates for conventional light harvesters due to their chemical robustness, earth abundance and adequate band gap. However, single semiconductor usually suffers from short diffusion length, fast recombination of photogenerated electron-hole pairs, difficulty to accelerate the interfacial charge transfer, poor electrical conductivity and sluggish oxygen evolution reaction kinetics, which limit their efficacy in PEC devices. Transition metal carbides, nitrides and carbonitrides (MXenes) is a new class of two-dimensional materials that has brought new opportunities to design synergistic systems for energy storage and conversion because of their interesting characteristics including rich interlayers groups, functional terminal groups and tunable optical and electronic properties. Therefore, decoration of semiconductors by MXene nanolayers or hybridization of MXene with semiconductor materials may facilitate to overcome the common obstacles including carriers’ separation efficiency, and poor electrochemical properties. MXene/semiconductor hybrid materials can boost the photogenerated carriers’ separation and transport and importantly revealed a significant performance as photoanodes. In fact, the new concept based on exploitation of MXene properties is crucial to generate enough space for accommodating charges (depletion zone, Schottky barriers) and enhance the electrical conductivity. Herein, an overview on MXene/semiconductor photoanodes current challenges and promising technologies for effective water oxidation is provided.

S-type asymptotic giant branch (AGB) stars are thought to be intermediates in the evolution of oxygen- to carbon-rich AGB stars. The chemical compositions of their circumstellar envelopes are also intermediate, but have not been studied in as much detail as their carbon- and oxygen-rich counterparts. We aim to determine the abundances of AlCl and AlF from rotational lines, which have been observed for the first time towards an S-type AGB star, W Aql. In combination with models based on PACS observations, we aim to update our chemical kinetics network based on these results. We analyse ALMA observations towards W Aql of AlCl in the ground and first two vibrationally excited states and AlF in the ground vibrational state. Using radiative transfer models, we determine the abundances and spatial abundance distributions of Al$^{35}$Cl, Al$^{37}$Cl, and AlF. We also model HCl and HF emission and compare these models to PACS spectra to constrain the abundances of these species. AlCl is found in clumps very close to the star, with emission confined within 0.1$^{\prime\prime}$ of the star. AlF emission is more extended, with faint emission extending 0.2$^{\prime\prime}$ to 0.6$^{\prime\prime}$ from the continuum peak. We find peak abundances, relative to H$_2$, of $1.7\times 10^{-7}$ for Al$^{35}$Cl, $7\times 10^{-8}$ for Al$^{37}$Cl and $1\times 10^{-7}$ for AlF. From the PACS spectra, we find abundances of $9.7\times 10^{-8}$ and $\leq 10^{-8}$, relative to H$_2$, for HCl and HF, respectively. The AlF abundance exceeds the solar F abundance, indicating that fluorine synthesised in the AGB star has already been dredged up to the surface of the star and ejected into the circumstellar envelope. From our analysis of chemical reactions in the wind, we conclude that AlF may participate in the dust formation process, but we cannot fully explain the rapid depletion of AlCl seen in the wind., Accepted for publication in Astronomy & Astrophysics

International audience; Optical properties of polymerized polyethylene layers deposited on glass substrates by PECVD technique at different radio frequency powers are studied through transmission and reflection spectra. Analysis of the experimental spectra by using conventional classic models which permit the determination of optical constants as the refractive index n, the dielectric permittivity \epsilon, the extinction k and absorption coefficients α which leads to the optical parameters characterizing the layers such as static refractive index ns,permittivity \epsilons, plasmon frequency ωp, carrier density to effective mass ratio N/m*e,optical conductivity σop, optical band gap Eg and dispersion diffusion energies E0 and Ed. These different values permit to select the suitable power for elaborate layers with performant properties for various applications in the field of communication, electrical isolation, and miniaturized optoelectronics and sensors devices. \textcopyright 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.

Alpha-Mannosidosis (AM) is an ultra-rare storage disorder caused by a deficiency of lysosomal alpha-mannosidase encoded by the MAN2B1 gene. Clinical presentation of AM includes mental retardation, recurrent infections, hearing loss, dysmorphic features, and motor dysfunctions. AM has never been reported in Tunisia. We report here the clinical and genetic study of six patients from two Tunisian families with AM. The AM diagnosis was confirmed by an enzymatic activity assay. Genetic investigation was conducted by Sanger sequencing of the mutational hotspots for the first family and by ES analysis for the second one. In the first family, a frameshift duplication p.(Ser802GlnfsTer129) was identified in the MAN2B1 gene. For the second family, ES analysis led to the identification of a missense mutation p.(Arg229Trp) in the MAN2B1 gene in four affected family members. The p.(Ser802GlnfsTer129) mutation induces a premature termination codon which may trigger RNA degradation by the NMD system. The decrease in the levels of MAN2B1 synthesis could explain the severe phenotype observed in the index case. According to the literature, the p.(Arg229Trp) missense variant does not have an impact on MAN2B1 maturation and transportation, which correlates with a moderate clinical sub-type. To explain the intra-familial variability of cognitive impairment, exome analysis allowed the identification of two likely pathogenic variants in GHR and SLC19A3 genes potentially associated to cognitive decline. The present study raises awareness about underdiagnosis of AM in the region that deprives patients from accessing adequate care. Indeed, early diagnosis is critical in order to prevent disease progression and to propose enzyme replacement therapy.

International audience; Task scheduling and data replication are highly coupled resource management techniques that are widely used by cloud providers to improve the overall system performance and ensure service level agreement (SLA) compliance while preserving their own economic profit. However, balancing the trade-off between system performance and provider profit is very challenging. In this paper, we propose a novel scheduling algorithm called Bottleneck and Cost Value Scheduling (BCVS) algorithm coupled with a novel dynamic data replication strategy called Correlation and Economic Model-based Replication (CEMR). The main goal is to improve data access effectiveness in order to meet service level objectives in terms of response time SLORT and minimum availability SLOMA, while preserving the provider profit. The BCVS algorithm focuses on reducing system bottleneck situations caused by data transfer when the CEMR focuses on preventing future SLA violations and guaranteeing a minimum availability. An economic model is also proposed to estimate the cloud provider profit. Simulation results indicate that the proposed combination of scheduling and replication algorithms offers higher monetary profit for the cloud provider by up to 30% compared to existing strategies. Moreover, it allows better performance.

International audience; Community detection has become an important research direction for data mining in complex networks. It aims to identify topological structures and discover patterns in complex networks, which presents an important problem of great significance. Prediction of communities from Protein-Protein Interaction (PPI) networks is important problem in system biology as they control different cellular functions. These networks represent a set of proteins that collaborate at the same cellular function. With the increment of genome-scale protein-protein interaction data for different species, various computational methods focus on identifying protein community from PPI networks. In this paper, we are interested in evaluating the proposed genetic algorithm GA-PPI-Net and three clustering methods for community detection. In the computational tests carried out in this work, the proposed genetic algorithm achieved excellent results to detect existing or even new communities from PPI networks.

International audience; Vietnam and Tunisia are southern countries, which both knew a tumultuous history, especially marked by the French colonization. But they are different, first from climate viewpoint (tropical for the one, Mediterranean for the other). We intend to compare their landscape dynamics since the beginning of the 20th century. We will based our talk on results, we obtained at local scale: Thua Thien-Hue province in Central Vietnam; the coastal dunes of the Governorate of Bizerte in northern Tunisia. The land use dynamics were mapped thanks to maps, satellite images and aerial photographs. We also conducted field studies and interviews with local people and forest managers.We will show that, beyond climate differences, common points can be identified in terms of anthropogenic pressure and its links with risks. With a time difference, both countries knew a decline of their forest area, due to a strong pressure. The inhabitants, poor, needed forest resources for their survival and forests represented a land reserve. The consequence was an increase of poor ecosystems: spatial extension of savannahs in Vietnam, dunes moving in Tunisia. By destroying their environment, people put themselves at risk. In fact, due to the forests decline, risks increase and threaten the local population. Soil erosion is stronger, floods become more dramatic and fires are more frequent and important. The growth of the exposed population increases more again risks. In Tunisia, these ones were perceived at the beginning of the 20th century and the solution was to reforest dunes. The positive effects are now visible and encourage to continue in this direction. In Vietnam, the main plantation programs were launched from 1990’s. Ambitious, they now concern considerable areas. Today, both countries know an increase of their forest area. They can serve as examples as forest plantations are encouraged worldwide to mitigate climate change.

International audience; In recent years, the decentralized development of ontologies has led to the generation of multiple ontologies of overlapping knowledge. This heterogeneity problem can be tackled by integrating existing ontologies to build a single coherent one. Ontology integration has been investigated during the last two decades, but it is still a challenging task.In this article, we provide a comprehensive survey of all ontology integration aspects. We discuss related notions and scrutinize existing techniques and literature approaches. We also detail the role of ontology matching in the ontology integration process. Indeed, the ontology community has adopted the splitting of the ontology integration problem into matching, merging and repairingsub-tasks, where matching is a necessary preceding step for merging, and repairing can be included in the matching process or performed separately. Ontology matching and merging systems have become quite proficient, however the trickiest part lies in the repairing step. We also focus on the case of a holistic integration of multiple heterogeneous ontologies, which needs further exploration. Finally, we investigate challenges,open issues, and future directions of the ontology integration and matching areas

We consider the coupled inverse problem of data completion and the determination of the best locations of an unknown number of small objects immersed in a stationary viscous fluid. We carefully introduce a novel method to solve this problem based on a game theory approach. A new algorithm is provided to recovering the missing data and the number of these objects and their approximate location simultaneously. The detection problem is formulated as a topological one. We present two test-cases that illustrate the efficiency of our original strategy to deal with the ill-posed problem., Nous étudions le problème de détection des petites inclusions immergées dans un fluide visqueux et incompressible, lorsque le mouvement de celui-ci est régi par les équations de Stokes. Des données du type Cauchy seront ainsi fournies seulement sur une partie frontière de l’écoulement.A cet égard, nous essayons de développer une méthode originale basée sur une approche de théorie des jeux, pour résoudre notre problème inverse. Un nouvel algorithme a été donc présenté traitant simultanément la question de la reconstruction des données manquantes avec celle de détection d’objets. La notion de gradient topologique a été utilisée afin de déterminer le nombre d’objets présents et leurs localisations approximatives. Dans cet objectif, une étude numérique présentée, a été effectuée pour prouver l’efficacité de la méthode.

International audience; Glass-fiber-reinforced concrete (GFRC) has been emerging as a widely used construction material that is suitable for many structural elements and particularly flat slabs. This paper presents mix design proportions of GFRC with 0%, 2% and 3% weight fractions of fibers and experimental tests including the 3-point bending tests (NT 21.123 (NF P18-407)) which are usually used in practice. These tests provide indirect information on tensile behavior. They are completed by an identification of the tensile behavior made by inverse analysis to obtain it from their bending response. For this purpose, an analytical damage model is developed to obtain bending moment–curvature constitutive behavior. The deduction of load–deflection relationship is established using different beam theories. It is shown that the classical beam theory is sufficient to estimate the behavior of short beams having a span to height ratio equal to 3 according to NT 21.123 recommendations. Finally, the developed model is applied in order to determine ultimate bending moment capacity as function of GFRC flat slab and beam thickness.

W-Ni-TiO2 nano-composite layers were electrodeposited on copper surface by both direct (DC) and pulse (PC) currents. The copper substrates are samples from the main electrical cable used for the Renault K-Z (the latest 100% electric vehicle). In order to investigate coating morphology, atomic force microscopy was used, while energy-dispersive x-ray analysis was applied to determine nano-composite composition. Based on surface morphology, the W-Ni-TiO2 (DC) alloy surface was covered by massive agglomerates, especially when the W-Ni-TiO2 (PC) nano-composite coating was more compact, thicker and exhibited smaller grain size. The coated surface revealed different contents such as 43.4 and 65.4% of W in DC and PC coatings, respectively, which are considered to be a novel composition of the W-Ni alloy. XRD studies revealed that the NiW2 phase only occurs in the W-Ni-TiO2 (PC) nano-composite alloy. Electrical and thermal conductivities, microhardness and porosity values are enhanced by the addition of TiO2 to the alloy.

High-resolution Fourier Transform spectra have been recorded at room temperature in the frequency region around 13 µm using a high-resolution Fourier transform spectrometer (Bruker IFS 125-HR). Transitions of both 12CH335Cl and 12CH337Cl isotopologues belonging to the P, Q and R branches of the ν3 and 2ν3-ν3 parallel bands have been analyzed to retrieve self-broadening coefficients using a multispectrum fitting procedure that allowed to fit simultaneously the whole set of the experimental spectra recorded at seven pressures of CH3Cl ranging from 1.02 to 10.24 mbar. Line positions were also derived using a wavenumber calibration performed by the frequencies of OCS transitions. About 2028 lines with 2 ≤ J ≤ 59 and 2 ≤ K ≤ 13 have been studied. The rotational J and K dependencies of the self-broadening coefficients have been clearly observed and modeled using a second-order empirical polynomial. The average accuracy of the line parameters has been estimated to be about 4 and 5% for the ν3 and 2ν3-ν3 bands, respectively. Using the Robert and Bonamy formalism with parabolic and exact trajectory models, these coefficients were calculated, showing the predominance of the dipole-dipole interaction. The J and K rotational dependencies are consistent with the measured data. The predicted values confirm that the use of the exact trajectory model does not improve the predicted linewidths for a molecule with a large dipole moment such as CH3Cl.

International audience; A series of novel ionic liquids (ILs) based on N-allyl-N,N-dimethylethylammonium (N112A+) are synthesized and characterized. Their physical properties and electrochemical stabilities are investigated and discussed toward the anion constituents. Herein, four anions are studied including one planar non-fluorinated anion (DCA−) and three fluorinated anions (TFSI−, OTf−, TFA−). The experimental properties are compared to those predicted by density functional theory (DFT) calculations. All salts are found to be low melting compounds while being liquid at room temperature. N112A-TFSI is the most thermally stable (Td = 329 °C) and N112A-TFA is the least stable (Td = 158 °C). The temperature effect on ILs transport properties is determined and discussed using the ionicity and Angell's fragility concepts. Among the good and fragile prepared ILs, N112A –DCA exhibits outstanding transport properties thanks to the low dynamic viscosity (19.97 mPa·s) and high ionic conductivity (19.20 mS·cm−1) reached at 298 K. These suitable properties are explained, from theoretical calculations, by the lower intermolecular interactions of ion-pairs in N112A –DCA and quantified by the decreased value of dispersion ion-pairs interaction energy (−6 kJ·mol−1). The electrochemical stability window (ESW) of selected ILs is strongly affected by the anion structure. The ESW values are found to decrease in the following order N112A-TFSI (4.40 V) > N112A-OTf (3.80 V) > N112A-DCA (3.00 V) > N112A-TFA (2.18 V). Taking into account the most likely oxidation and reduction reactions, the ESWs are discussed and validated by the density-based solvent model (SMD). The experimental values of ESWs are very close to the predicted ones.

International audience; A R T I C L E I N F O Keywords: Change detection Change analysis Multi-temporal remote sensed images Dempster-Shafer Theory Conflict analysis Change Measure A B S T R A C T Change detection monitoring on multi-temporal remote sensed images is a persistent methodological challenge where the Dempster-Shafer, or evidence, Theory (DST) has been often applied. This paper presents a new method based on the use of DST for mining bi-temporal remotely sensed images change. The main idea is based on the investigation, analysis and interpretation of different types of conflict between two bi-temporal mass distributions. The reasoning process is focused on the conflict significance and its "partial" causes. In fact, the global conflict that occurs during the joint exploitation of multi-temporal images gives general and non-sufficiently concise information. However, the partial conflict provides rich and important information with regards to the disagreement between knowledge sources. For computing the partial conflict between focal elements, the geometric representation of mass distributions is exploited. The obtained conflict measures, caused by change, are analyzed latter by a new algorithm for drifting binary change map and identifying change directions. The effectiveness and reliability of the proposed approach are shown through experimentations on simulated changed images as well as using multi-temporal Landsat satellite images where qualitative criteria as well as quantitative measures are applied. The performances of the proposed approach, in terms of changed area recognition , are compared to three different and widely used conflict measures: the Empty-set mass, the Jousselme's distance and the Cosine measure. It is shown that the developed change detection approach out-performs these conflict measures.

International audience; In this study, Cu2ZnxFe1-xSnS4 (CZFTS) (0 ≤ x ≤ 1) thin films were grown under vacuum evaporation on unheated glass substrates followed by sulfurization at 400 °C. The effects of sulfurization on the structural, morphological and optical properties were investigated for CZFTS material by varying Fe content. Crystal structure and phase of CZFTS thin films were analyzed by X-ray diffraction technique and Raman spectroscopy. In addition, the elemental composition and the stoichiometry of films were studied using energy dispersive spectroscopy. Surface morphology of samples was examined by scanning electron microscopy. Optical properties such as absorption coefficient, and gap energies were determined by the measurement of transmittance and reflectance in the spectral range 300–1800 nm. X-ray analysis indicates that all sulfurized CZFTS films present a polycrystalline nature and exhibit a preferential orientation along (112) plane. Cu2FeSnS4 (x = 0) and Cu2ZnSnS4 (x = 1) crystallize in stannite structure with I-42 m and kesterite structure with I-4 space group, respectively. Raman analysis and elemental composition confirm that only the Cu2ZnSnS4 (x = 1) and CZ0.75F0.25TS (x = 0.75) phases are present with good crystallinity. Transmittance and reflectance spectra revealed that the films are homogenous mostly for x = 0.75 and 1. Structural and optical parameters like crystallite size, absorption coefficient and band gaps were estimated for all the x values.

Among the closed-shell hydrocarbons, the carbenes c- and l-C3H2 are the lightest ones to display a permanent electric dipole moment and be detectable by rotational spectroscopy. The cyclic form, cyclopropenylidene, is ubiquitous in the InterStellar Matter (ISM) of the Milky Way and external galaxies. As such, it serves as a marker to help in characterizing the physical conditions of the ISM. The linear form, propadienylidene, is less abundant. In order to get access to their absolute and relative abundances, it is essential to understand their collisional excitation/quenching schemes. We compute here a precise ab initio potential energy surface for the interaction of c- and l-C3H2 with helium, by means of a CCSD(T)-F12a formalism and a fit onto relevant spherical harmonics functions. We conduct quantum dynamical scattering in order to get precise cross sections using a coupled-channel approach for solving the nuclear motion. We average sections to have rates for rotational quenching from 5 to 150 K. We show that these new rates are vastly different, up to more than an order of magnitude, from the older rates presented in the literature, computed with angular momentum algebra only. We expect large differences in the astrophysical analyses of C3H2, including the chemical history of those ubiquitous carbenes.

International audience; Severe acute respiratory syndrome SARS-CoV-2 virus led to notable challenges amongst researchers in view of development of new and fast detecting techniques. In this regard, surface-enhanced Raman spectroscopy (SERS) technique, providing a fingerprint characteristic for each material, would be an interesting approach. The current study encompasses the fabrication of a SERS sensor to study the SARS-CoV-2 S1 (RBD) spike protein of the SARS-CoV-2 virus family. The SERS sensor consists of a silicon nanowires (SiNWs) substrate decorated with plasmonic silver nanoparticles (AgNPs). Both SiNWs fabrication and AgNPs decoration were achieved by a relatively simple wet chemical processing method. The study deliberately projects the factors that influence the growth of silicon nanowires, uniform decoration of AgNPs onto the SiNWs matrix along with detection of Rhodamine-6G (R6G) to optimize the best conditions for enhanced sensing of the spike protein. Increasing the time period of etching process resulted in enhanced SiNWs’ length from 0.55 to 7.34 µm. Furthermore, the variation of the immersion time in the decoration process of AgNPs onto SiNWs ensued the optimum time period for the enhancement in the sensitivity of detection. Tremendous increase in sensitivity of R6G detection was perceived on SiNWs etched for 2 min (length=0.90 µm), followed by 30s of immersion time for their optimal decoration by AgNPs. These SiNWs/AgNPs SERS-based sensors were able to detect the spike protein at a concentration down to 9.3 × 10−12 M. Strong and dominant peaks at 1280, 1404, 1495, 1541 and 1609 cm−1 were spotted at a fraction of a minute. Moreover, direct, ultra-fast, facile, and affordable optoelectronic SiNWs/AgNPs sensors tuned to function as a biosensor for detecting the spike protein even at a trace level (pico molar concentration). The current findings hold great promise for the utilization of SERS as an innovative approach in the diagnosis domain of infections at very early stages.

International audience; Non-Intrusive Load Monitoring (NILM) refers to the analysis of the aggregated current and voltage measurements of Home Electrical Appliances (HEAs) recorded by the house electrical panel. Such methods aim to identify each HEA for a better control of the energy consumption and for future smart grid applications. Here, we are interested in an event-based NILM pipeline, and particularly in the HEAs’ recognition step. This paper focuses on the selection of relevant and understandable features for efficiently discriminating distinct HEAs. Our contributions are manifold. First, we introduce a new publicly available annotated dataset of individual HEAs described by a large set of electrical features computed from current and voltage measurements in steady-state conditions. Second, we investigate through a comparative evaluation a large number of new methods resulting from the combination of different feature selection techniques with several classification algorithms. To this end, we also investigate an original feature selection method based on a deep neural network architecture. Then, through a machine learning framework, we study the benefits of these methods for improving Home Electrical Appliance (HEA) identification in a supervised classification scenario. Finally, we introduce new transfer learning results, which confirm the relevance and the robustness of the selected features learned from our proposed dataset when they are transferred to a larger dataset. As a result, the best investigated methods outperform the previous state-of-the-art results and reach a maximum recognition accuracy above 99% on the PLAID evaluation dataset.

Adaptive learning is learning that tries to get closer to the learner in order to identify his/her strengths and weaknesses and to provide him/her with a learning that best adapts to his/her needs, thereby increasing his/her chances of success. It is in this spirit that this work was carried out. It is interested in adaptation of learning when using a Learning Management System (LMS). To achieve our goal, we designed different models such as the Learner Model and a multi-agents system, ADOPT, which defines intelligent interactive agents. These agents analyze the traces left by the learner, calculate various indicators and propose the most suitable adaptations for the learner.

In case of fire in a structure, concrete undergoes internal transformations that can alter its durability. It is also important to take into account the effect of the cooling regime after temperature exposure on the phase assemblage of the cementitious matrix. An experimental investigation was carried out to investigate the changes of a cement paste, heated up to various temperature up to 1000 °C then cooled in water or cooled in air for comparison. Quantitative evolution of phase assemblage is obtained by various techniques (TGA, XRD, NMR and ICP-AES). For both cooling regimes, the hydrated crystallised phases tend to become disordered phases for lower exposition temperature. These phases coexist with anhydrous products for intermediate temperature and these new anhydrous phases become the majority for higher temperature. However, the two cooling regimes show differences. Equilibrium of hydrated aluminate phases is modified, (e.g. AFm/AFt ratio). There are structural modifications of the phases in particular for C-S-H. For water cooling regime, beyond 600 °C, a leaching is observed in particular for calcium.

The Internet of Things (IoT) refers to any system where objects are connected to the Internet; it incorporates network connectivity architecture, advanced sensors and devices. According to recent research, about 30 billion objects are now collecting data and performing all sorts of tasks.The aim of this thesis is the development in a small space of a low frequency miniature and super-directive antenna array. Coupling will be taken into account in this work and the optimal weightings necessary to maximize directivity will be determined. Prototypes will also be produced to validate the simulation results. The study and 3D electromagnetic simulation of the antennas will be carried out mainly with commercial software (HFSS, CST, …).In our first study, a switchable beam and super-directive Electrically Small Antenna (ESA) dipole deployed at an IoT network gateway at 868 MHz was presented. Reconfigurability is achieved using PIN diodes to reduce the back radiation and to steer the beam to the desired direction. The proposed structure generates a high directivity of 6.8 dBi in simulation and 6.7 dBi in measurement at 868 MHz for each beam in the azimuth plane.In the second study, we thought about improving the antenna gain previously presented. Getting inspired by the Yagi antenna structure, we added four directors to each element to enhance the directivity and to steer the main bean in two different directions. A simulated directivity of 8.5 dBi in simulation and 8.4 dBi in measurement at 868 MHz for both directions.To maintain low-side lobes, we propose the use of a Non-Foster circuit to convert positive impedance into negative impedance, as a load for the parasitic element to take into account the resistive part of the load and thus maximize the gain of the array. The other advantage with this kind of circuit is that it facilitates reconfigurability in several directions by just varying the load impedance to be converted.; L'Internet des objets (IoT) fait référence à tout système où les objets sont connectés à Internet, il intègre une architecture de connectivité réseau, des capteurs et des appareils intelligents. Selon des recherches récentes, environ 30 milliards d'objets collectent désormais des données et effectuent toutes sortes de tâches. Déployées dans des environnements intelligents, tels que les maisons intelligentes, les villes intelligentes et les transports intelligents.Le but de cette thèse est le développement dans un espace réduit, réseau d'antennes miniatures basse fréquence, en vue d’atteindre une super directivité et reconfigurable pour une communication longue portée et dans des zones difficiles d'accès. Le couplage sera pris en compte dans cette tâche et les pondérations optimales nécessaires pour maximiser la directivité seront déterminées. Des prototypes seront également produits pour valider les résultats de la simulation. L'étude et la simulation électromagnétique 3D des antennes seront réalisées principalement avec des logiciels commerciaux (HFSS, CST,…).Dans notre première étude, un réseau parasite d’antennes formé de deux éléments électriquement petits pour les applications Internet de l’objet, déployé à la fréquence 868 MHz , a été présenté qui est capable de commuter son faisceau suivant deux directions différentes. La reconfigurabilité est obtenue à l'aide de diodes PIN pour réduire le rayonnement arrière et diriger le faisceau dans la direction souhaitée. La structure proposée génère une directivité élevée de 6,8 dBi en simulation et 6,7 dBi en mesure à 868 MHz pour chaque direction dans le plan azimutal.Dans la seconde étude, nous avons tenté d'améliorer le gain de l'antenne présentée précédemment. En nous inspirant de la structure de l'antenne Yagi, nous avons pensé à ajouter quatre directeurs de chaque coté pour améliorer la directivité et orienter le lobe principal dans deux directions différentes. La directivité simulée est d’environ 8,5 dBi en simulation et de 8,4 dBi en mesure à 868 MHz dans deux directions différentes dans le plan azimutal.En vue de réduire le rayonnement arrière, le potentiel de l’électronique active a été exploité. Nous proposons l'utilisation d'un circuit Non-Foster pour convertir une impédance positive en impédance négative, comme charge à appliquer sur l'élément parasite. La partie résistive de la charge a été prise en considération pour maximiser le gain total du réseau. L'autre avantage de ce type de circuit est qu'il facilite la reconfigurabilité dans plusieurs directions en faisant simplement varier l'impédance de charge à convertir.

International audience; We have successfully synthesized and transferred graphene (Gr) monolayers on top of epitaxial mixed valence La0.7Sr0.3CoO3 (LSCO) thin films. Raman spectroscopy reveals that Jahn-Teller (JT) modes associated with the oxygen octahedral distortions usually unobserved for bare LSCO are activated by the deposited graphene. The appearance of these JT modes in the Gr/LSCO heterostructure is attributed to the electronic interactions at the interface between the graphene and the LSCO thin film promoting intermediate spin states of the Co ions. As a result, the magnetic properties of LSCO are affected. Indeed, magnetization measurements show a phase transition at ~135 K which is due to the presence of the graphene while the ferromagnetic transition of bare LSCO films is observed at~200 K. This magnetic phase is confirmed by Raman spectroscopy measurements as a function of temperature revealing a vibrational transition around the same temperature.

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International audience; The Response Surface Methodology (RSM) was used to optimize the air drying of bay leaves (Laurus nobilis). The study focused on different values for the following parameters: temperature, relative humidity and drying air velocity. The responses measured included: leaf quality (color), drying time and mass diffusivity across a leaf. Second-order polynomial equations were used to analyze the effects of drying conditions on these parameters. Optimum drying conditions were identified by minimizing the drying time, the moisture content and variations in color. These optimum conditions were: 59.87 • C, 15.00 % and 1.51 m/s, respectively, for temperature, relative humidity and velocity. These conditions were then validated experimentally.

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This thesis aims to study the ability of theoretic game approaches to deal with ill-posed problems. The first part of the thesis is dedicated to the Stokes system’s linear problem, with the goal of detecting unknown geometric inclusions or pointwise sources in a stationary viscous fluid, using a single compatible pair of Dirichlet and Neumann data, available only on a partially accessible part of the boundary. Inverse geometric-or-source identification for the Cauchy-Stokes problem is severely ill-posed (in the sense of Hadamard) for both the inclusions or sources and the missing data reconstructions, and designing stable and efficient algorithms is challenging. To solve the joint completion/detection problem, we reformulate it as a three players Nash game. The two first players aim at recovering the missing data (Dirichlet and Neumann conditions prescribed over the inaccessible boundary), while the third player seeks to identify the shape and locations of the inclusions (in Chapter 2) or determine the source term (in Chapter 3). We then introduce new algorithms dedicated to the Nash equilibria, which is expected to approximate the original coupled problems’ solutions. We present different numerical experiments to illustrate the efficiency and robustness of our 3- player Nash game strategy. The extension of this work to another situation, such as identifying small objects, has been carried out (in Chapter 4). The second purpose of this thesis is to extend those results to the case of quasi-Newtonian fluid flow whose viscosity is assumed to be a nonlinear function that varies upon the imposed rate of deformation. The considered problem then is a nonlinear Cauchy type because of the non-linearity of the viscosity function. Two different iterative procedures, control-type and Nash game algorithms, are considered to solve it. From a computational point of view, the non-linearity needs some particular algorithms. We propose a novel one-shot algorithm to solve the nonlinear state equations during a recovery process, representing a different idea to treat the nonlinear Cauchy problems. Some numerical experiments are provided to demonstrate our algorithm’s efficiency in the noise-free and noisy data cases. A comparison between the one-shot scheme and the fixed-point method was performed. Finally, we introduce an algorithm to jointly recover the missing boundary data and the location and shape of the inclusions for nonlinear Stokes models based on the Game-Theoretic approach.; Dans cette thèse, on s’intéresse à étudier la capacité de l’approche de la théorie des jeux à traiter certains problèmes inverses ‘mal posé’, gouvernés par les équations de Stokes ou quasi-Stokes. La première partie concerne la détection d’un ou plusieurs objets (Chapitre 2), et l’identification de sources ponctuelles dans un écoulement (Chapitre 3), en utilisant des données du type Cauchy qui seront ainsi fournies seulement sur une partie frontière de l’écoulement. Ce type de problème est mal posé au sens d’Hadamard du fait de l’absence de solution si les données ne sont pas compatibles mais surtout du fait de son extrême sensibilité aux données bruitées, dans le sens où une légère perturbation des données entraine une grande perturbation de la solution. Cette difficulté de stabilité fournit aux chercheurs un défi intéressant pour la mise au point de méthodes numériques permettant d’approcher de la solution du problème inverse original. L’approche développée ici est différente de celles existantes, elle a traité simultanément la question de la reconstruction des données manquantes avec celle de l’identification des inclusions ou de sources ponctuelles dans un fluide visqueux, incompressible et stationnaire. En considérant une méthode de type minimisation de critères, la solution est réinterprétée en termes d’équilibre de Nash entre les deux problèmes complétion/identification. Des nouveaux algorithmes originaux dédiés au calcul d’équilibre de Nash sont présenté et implémenté avec FreeFem ++. Une extension pour le problème d’identification de petits objets de l’approche proposée de jeu de Nash a été réalisé (Chapitre 4). La deuxième partie est consacrée à la résolution des problèmes inverses non linéaires dans le cadre des écoulements de fluide quasi-newtonien (Chapitre 5). La viscosité est supposée une fonction non linéaire, varie en fonction du tenseur des déformations. Un problème inverse non linéaire du type Cauchy est reformulé comme un problème du contrôle optimal, puis comme un jeu de Nash à deux joueurs. Deux algorithmes ont été utilisés et comparés afin de résoudre les problèmes aux limites non linéaires : un algorithme classique de point fixe et un nouveau schéma proposé ‘one-shots’. Enfin, on applique la théorie des jeux pour la résolution du problème de couplage de complétion des données etidentification des inclusions pour le modèle de quasi-Stokes.

Populations in North Africa (NA) are characterized by a high rate of consanguinity. Consequently, the proportion of founder mutations might be higher than expected and could be a major cause for the high prevalence of recessive genetic disorders like Fanconi anemia (FA). We report clinical, cytogenetic, and molecular characterization ofFANCAin 29 North African FA patients from Tunisia, Libya, and Algeria. Cytogenetic tests revealed high rates of spontaneous chromosome breakages for all patients except two of them.FANCAmolecular analysis was performed using three different molecular approaches which allowed us to identify causal mutations as homozygous or compound heterozygous forms. It included a nonsense mutation (c.2749C > T; p.Arg917Ter), one reported missense mutation (c.1304G > A; p.Arg435His), a novel missense variant (c.1258G > A; p.Asp409Glu), and theFANCAmost common reported mutation (c.3788_3790delTCT; p.Phe1263del). Furthermore, three founder mutations were identified in 86.7% of the 22 Tunisian patients: (1) a deletion of exon 15, in 36.4% patients (8/22); (2), a deletion of exons 4 and 5 in 23% (5/22) and (3) an intronic mutation c.2222 + 166G > A, in 27.3% (6/22). Despite the relatively small number of patients studied, our results depict the mutational landscape of FA among NA populations and it should be taken into consideration for appropriate genetic counseling.