Université d'Orléans
  • Orléans, Centre, France
Recent publications
The discovery of several machine learning and deep learning techniques has paved the way to extend the reach of humans in various real-world applications. Classical machine learning algorithms assume that training, validation, and testing data come from the same domain, with similar input feature spaces and data distribution characteristics. In some real-world exercises, where data collection has become difficult, the above assumption does not hold true. Even, if possible, the scarcity of rightful data prevents the model from being successfully trained. Compensating for outdated data, reducing the need and hardship of recollecting the training data, avoiding many expensive data labeling efforts, and improving the foreseen accuracy of testing data are some significant contributions of transfer learning in the real-world application. The most cited transfer learning application includes classification, regression, and clustering problems in activity recognition, image and video classification, wi-fi localization, detection and tracking, sentiment analysis and classification, and web-document classification. Human activity recognition plays a cardinal role in human- to-human and human-to-object interaction and interpersonal relations. Pairing with robust deep learning algorithms and improved hardware technologies, automatic recognition of human activity has opened the door in the direction of constructing a smart society. To the best of our knowledge, our survey is the first to link machine learning, transfer learning, and vision sensor-based activity recognition under one roof.. However, this survey exploits the above connection by reviewing around 350 related research articles from 2011 to 2021. Findings indicate an approximate 15% increment in research publications connected to our topic every year. Among these reviewed articles, we have selected around 150 significant ones that give insights into various activity levels, classification techniques, performance measures, challenges, and future directions related to transfer learning enhanced vision sensor-based HAR.
Te valorization of Crocus sativus focuses mainly on the plant's stigma because it is one of the most expensive and valuable spices in the world and has great value in the food, cosmetics, and pharmacological industries. Due to this high stigma value, the other parts of the plant are considered as by-products; our study aimed to evaluate the myorelaxant and antispasmodic activities of the byproducts (tepals and leaves) to compare them with the stigma of the plant. To investigate the myorelaxant and antispasmodic activities of the Crocus sativus on isolated rabbit and rat jejunum, we used an in vitro technic with an organ bath and an isotonic transducer. Our results showed that the STG (hydroethanolic extract of stigmas) and LV (hydroethanolic extract of leaves) had a moderate myorelaxant efect with IC 50 = 6.61 ± 1.5 and 5.08 ± 0.45 mg/ml, respectively. TPL (hydroethanolic extract of tepals) had a signifcant (p˂0.001) inhibitory efect on the amplitude of the rabbit jejunum basic contractions with an IC 50 = 1.36 ± 0.15 mg/ml. TPL also caused a signifcant (p˂0.001) antispasmodic activity depending on the dose of the contraction induced by CCh (10 −6 M) and KCl (25 mM). Te antispasmodic efect of the TPL is slightly altered in the presence of nifedipine by a percentage of 26.8%. Tis diference is statistically signifcant (p˂0.01). Terefore, the extract could induce the inhibitory efect on L-type voltage-dependent Ca 2+ channels, but not on the guanylate cyclase and nitric oxide pathways. Tat confrmed that the TPL has a comparable efect to the verapamil. Te HPLC-DAD analysis of various parts of C. sativus shows that the three extracts contain the kaempferol favanol compound, the STG also was revealed to be rich in carotenoids crocin, and these isomers are trans and cis-crocin, safranal, and picrocrocin. In contrast, the TPL revealed the presence of isorhamnetin and quercetin, but the LV was rich in hesperidin and mangiferin. In conclusion, this study supports the traditional use of this plant to treat digestive problems and will allow us to explore future possibilities for treating bowel spasms using natural molecules derived from safron.
LIM kinase 1 (LIMK1) and LIM kinase 2 (LIMK2) are serine/threonine and tyrosine kinases and the only two members of the LIM kinase family. They play a crucial role in the regulation of cytoskeleton dynamics by controlling actin filaments and microtubule turnover, especially through the phosphorylation of cofilin, an actin depolymerising factor. Thus, they are involved in many biological processes, such as cell cycle, cell migration, and neuronal differentiation. Consequently, they are also part of numerous pathological mechanisms, especially in cancer, where their involvement has been reported for a few years and has led to the development of a wide range of inhibitors. LIMK1 and LIMK2 are known to be part of the Rho family GTPase signal transduction pathways, but many more partners have been discovered over the decades, and both LIMKs are suspected to be part of an extended and various range of regulation pathways. In this review, we propose to consider the different molecular mechanisms involving LIM kinases and their associated signalling pathways, and to offer a better understanding of their variety of actions within the physiology and physiopathology of the cell.
This article examines the particular place of the quintuple canonization of 1622 in the long history of papal canonization. While the papacy gradually imposed its control over the creation of new saints in the Middle Ages, in the Modern Era it faced a double challenge to its practice. On the one hand, Luther condemned the elevation to the altars in 1523 of the Saxon bishop Benno of Meissen, in which he saw the creation of a new idol. And, in fact, a long silence from the Roman Curia followed. On the other hand, when Sixtus V decided to canonize a new saint in 1588 in response to the insistent request of Philip II of Spain, the Roman Curia was confronted with strong pressure from the new orders to have their founder canonized in the context of a multiplication of cults of beati that was beyond its control. The quintuple canonization of 1622 was the triumph of these orders and their founder, but Urban VIII drew radical consequences in the years that followed. He decided to impose new rules of procedure that allowed Rome to extend its monopoly to the cult of the beati and to regain for a few decades the parsimony of medieval canonization.
Owing to the superior thermal insulating attributes of rigid polyurethane foam (RPUF) compared to other insulating materials (expanded and extruded polystyrene, mineral wool), it remains the most dominant insulating material and most studied polymer foam. Like other polyurethane foam, RPUF is highly flammable, necessitating the incorporation of flame retardants (FR) during production to lower combustibility, promoting its continuous use as insulation material in construction, transportation, and others. The popular approaches for correcting the high flammability of RPUF are copolymerization and blending (with FR). The second method has proven to be most effective as there are limited trade-offs in RPUF properties. Meanwhile, the high flammability of RPUF is still a significant hindrance in emerging applications (sensors, space travel, and others), and this has continuously inspired research in the flame retardancy of RPUF. In this study, properties, and preparation methods of RPUF are described, factors responsible for the high flammability of PUF are discussed, and flame retardancy of RPUF is thoroughly reviewed. Notably, most FR for RPUF are inorganic nanoparticles, lignin, intumescent FR systems of expandable graphite (EG), ammonium polyphosphate (APP), and hybridized APP or EG with other FR. These could be due to their ease of processing, low cost, and being environmentally benign. Elaborate discussion on RPUF FR mechanisms were also highlighted. Lastly, a summary and future perspectives in fireproofing RPUF are provided, which could inspire the design of new FR for RPUF.
Cinnamon (Cinnamomum spp.) is one of the oldest spices known to humankind and is used in culinary and traditional medicine practices. It is obtained from the inner bark of cinnamon trees and contains cinnamalde-hyde, cinnamic acid, and cinnamate responsible for its antimicrobial activities. The focus on agri-food industry challenges, such as sustainability, antibiotic-resistant, eco-friendly farming, and the clean label, has been highlighted and increased. Therefore, the review will give a critical snapshot of cinnamon's potential to respond to the agri-food industry challenge. Cinnamon essential oil, obtained from both bark and leave, has been widely used as an antimicrobial ingredient against spoilage microorganisms and foodborne pathogens in the formulations of biodegradative films, edible coating, and adhesive patches. In addition to antibacterial and antifungal activity shown by these packaging, the cinnamon essential oil can improve the barrier, thermal and mechanical properties of films and coatings.
We show that, in any space-time dimension, the on-shell (electric) conformal Carrollian scalar can be interpreted as the flat-space limit of the singleton representation of the conformal algebra. In fact, a recently proposed higher-spin algebra for Minkowski spacetime amounts to the Poincaré enveloping algebra on the corresponding module. This higher-spin algebra is a contraction of that entering Vasiliev's equations, which can be constructed analogously from the singleton representation of the conformal algebra. We also show that the higher-spin extension of the Poincaré algebra we consider is a subalgebra of all symmetries of the conformal Carrollian scalar, given by a higher-spin version of the (extended) BMS algebra.
With the increase in agriculture intensity, associated with the use of nitrogen-based fertilizers, nitrate pollution is starting to be an issue in soils and waters. Therefore, there is a need to find a way to prevent nitrate from leaching from the soils by retaining it into the soil. One of the solutions is to use carbon-based amendments such as activated carbon, which has a good sorption capacity. This study aimed at evaluating the sorption capacities of several activated carbons towards nitrate, and study the effects of different parameters, i.e. initial nitrate concentration, initial solution pH, contact time and co-existing anions, on their sorption capacities. Results showed that among eight tested activated carbons, from different feedstocks, four (L27, 2 K, 5 K, CS) presented a high sorption capacity, between 5.91 and 14.55 mg.g−1, which was affected (p < 0.001) by contact time (maximum sorption occurred within 60 min), solution pH (maximum sorption at pH 2) and the presence of co-existing anions. Moreover, the construction of sorption isotherms showed that sorption occurred mainly through monolayer, while the kinetic model showed a chemical sorption mechanism. Finally, infra-red analysis of the activated carbons revealed that various functional groups were involved in the sorption but also that electrostatic interaction was not the only sorption mechanism. This study demonstrates the importance of feedstock and activation type, as well as particular properties of activated carbon for the sorption of nitrate. It also shows the potential of four materials (L27,2 K, 5 K, CS) for the retention of nitrate in water-soil systems.
Various approaches have been used for the preparation of heterostructured materials based on clay minerals, with numerous potential applications offered by the resulting functional materials. In this study, a fibrous clay mineral (palygorskite) and a tetraethyl orthosilicate reagent were used to obtain silica–palygorskite heterostructures. The aim was to highlight the influence of two factors during the preparation process: the effect of acid activation pre-treatment of the palygorskite with HCl and the effect of varying the length of the amine chains used – dodecylamine and butylamine – on the formation and development of silica nanoparticles on the surface of the palygorskite fibres. The silica–palygorskite heterostructures were obtained after the removal of the organic templates by calcination at 500°C. The textural and structural properties of the silica–palygorskite heterostructured samples were determined using various experimental characterization techniques, such as X-ray diffraction, transmission electron microscopy, gas adsorption and Fourier-transform infrared spectroscopy. The experimental variables targeted in this study appeared to have a significant effect on the textural properties of the silica–palygorskite heterostructure obtained. The great specific surface area and the mesoporous, microporous and ultramicroporous volumes as determined using nitrogen and/or carbon dioxide gas adsorption confirm the benefit of combining the acid activation pre-treatment of the fibrous clay mineral with the use of a long-chain amine co-surfactant (dodecylamine). The resulting silica–palygorskite heterostucture has a great specific surface area (628 m ² g –1 ) and a well-developed total pore network ( V N2 = 0.24 cm ³ g –1 ; V ultra (CO2) = 0.18 cm ³ g –1 ). This material will be tested for the removal of volatile organic compounds at low concentrations.
Designed to increase safety of people and property during their different stages of life (storage, transportation, handling), low-vulnerability ammunitions (LOVA) can lead to ignition issues during their use. Ignition and combustion characteristics of two LOVA RDX-based gun propellants are experimentally investigated in this paper. The ignition is performed by a laser diode, and combustion is studied in a closed-volume reactor for different initial pressures (10–70 bar) and laser powers (1.39 to 10.13 W). The present study especially focuses on the influence of atmosphere nature: new results under synthetic air are compared to results previously obtained under argon and nitrogen. Air appears to have a different effect on combustion properties following the nature of the propellant. For P1, composed of RDX and HTPB, the highest overpressures and propagation rates are obtained under air. On the contrary, similar performances have been encountered under air and argon for the RDX/NC propellant P2. Ignition delays and probabilities, as for them, seem to be more sensitive to laser power than to atmosphere nature.
Binary alkali silicate glasses were synthesized as beads by aerodynamic levitation coupled to laser heating to test the applicability of the method to this compositional range. While bubble‐free lithium disilicate beads could be easily obtained, sodium and potassium silicates proved more challenging to melt without significant alkali evaporation: the final samples contained bubbles and exhibited compositional drifts compared to the starting stoichiometry, especially at high SiO2 content. The risk of volatilization from the melts was evaluated empirically: the volatility of each oxide component scaled to the ratio between its melting temperature Tm and the Tm of the target composition (revap), while the difference between such ratios (Δevap) provided a qualitative estimation of the risk of differential evaporation. The formulated approach enables to evaluate the suitability of aerodynamic levitation synthesis for a given target glass composition: while low melting temperature and low liquidus viscosity (η < 100 Pa s) represent the primary optimal conditions, more viscous materials can still be prepared without major compositional drifts using a more careful melting procedure, especially if revap and Δevap are minimized. This article is protected by copyright. All rights reserved
Citation: Aquino, R.; de Concini, V.; Dhenain, M.; Lam, S.; Gosset, D.; Baquedano, L.; Forero, M.G.; Menuet, A.; Baril, P.; Pichon, C. Intrahippoc-ampal Inoculation of Aβ 1-42 Peptide in Rat as a Model of Alzheimer Model of Alzheimer Disease Identified MicroRNA-146a-5p as Blood Marker with Anti-Inflam-matory Function in Astrocyte Cells. Cells 2023, 12, 694. https://doi. Abstract: Circulating microRNAs (miRNAs) have aroused a lot of interest as reliable blood diagnostic biomarkers of Alzheimer's disease (AD). Here, we investigated the panel of expressed blood miRNAs in response to aggregated Aβ 1-42 peptides infused in the hippocampus of adult rats to mimic events of the early onset of non-familial AD disorder. Aβ 1-42 peptides in the hippocampus led to cognitive impairments associated with an astrogliosis and downregulation of circulating miRNA-146a-5p,-29a-3p,-29c-3p,-125b-5p, and-191-5p. We established the kinetics of expression of selected miRNAs and found differences with those detected in the APP swe /PS1 dE9 transgenic mouse model. Of note, miRNA-146a-5p was exclusively dysregulated in the Aβ-induced AD model. The treatment of primary astrocytes with Aβ 1-42 peptides led to miRNA-146a-5p upregulation though the activation of the NF-κB signaling pathway, which in turn downregulated IRAK-1 but not TRAF-6 expression. As a consequence, no induction of IL-1β, IL-6, or TNF-α was detected. Astrocytes treated with a miRNA-146-5p inhibitor rescued IRAK-1 and changed TRAF-6 steady-state levels that correlated with the induction of IL-6, IL-1β, and CXCL1 production, indicating that miRNA-146a-5p operates anti-inflammatory functions through a NF-κB pathway negative feedback loop. Overall, we report a panel of circulating miRNAs that correlated with Aβ 1-42 peptides' presence in the hippocampus and provide mechanistic insights into miRNA-146a-5p biological function in the development of the early stage of sporadic AD.
Stability and sensitivity of two- and three-dimensional global modes developing on steady spanwise-homogeneous laminar separated flows around NACA 4412 swept wings are numerically investigated for different Reynolds numbers and angles of attack. The wake dynamics are driven by the two-dimensional von Kármán mode whose emergence threshold in the α–Re plane is computed with that of the three-dimensional centrifugal mode. At the critical Reynolds number, the Strouhal number, the streamwise wavenumber of the von Kármán mode and the spanwise wavenumber of the leading three-dimensional centrifugal mode scale as a power law of α. The introduction of a sweep angle attenuates the growth of all unstable modes and entails a Doppler effect in the leading modes' dynamics and a shift towards non-zero frequencies of the three-dimensional centrifugal modes. These are found to be non-dispersive as opposed to the von Kármán modes. Sensitivity of the leading global modes is investigated in the vicinity of the critical conditions through adjoint-based methods. The growth rate sensitivity map displays a region on the suction side of the wing, wherein a streamwise oriented force has a net stabilising effect, comparable to what could have been obtained inside the recirculation bubble. In agreement with the predictions of the sensitivity analysis, a spanwise-homogeneous force suppresses the Hopf bifurcation and stabilises the entire branch of von Kármán modes. In the limit of small amplitudes, passive control via spanwise-wavy forcing produces a stabilising effect similar to that of a spanwise-homogeneous control and results to be more effective than localised spherical forces.
The current work was designed to evaluate the antioxidant activity and antidiabetic effect of Ficus carica L. extracts. For that, the leaves and buds of Ficus carica L. were analyzed to determine their polyphenolic and flavonoid contents and antioxidant activity. Diabetes was induced by a single dose of alloxan monohydrate (65 mg/kg body weight), then diabetic rats were treated with a dose of 200 mg/kg body weight of the methanolic extracts of Ficus carica leaves or buds or their combination for 30 days. Throughout the experiment, blood sugar and body weight were measured every 5 and 7 days respectively. At the end of the experiment, serum and urine were collected for analysis of alanine aminotransferase, aspartate aminotransferase, total cholesterol, triglycerides, creatinine, uric acid, urea, proteins, sodium, potassium, and chloride. Pancreas, liver, and kidney were removed to estimate catalase, glutathione peroxidase, and glutathione activities; lipid peroxidation products were also determined. The results obtained revealed that alloxan has induced hyperglycemia, increased liver and renal biomarkers levels, reduced antioxidative enzymes, and induced lipid peroxidation. However, the treatment with Ficus carica leaf and bud extracts, especially their combination, has attenuated all pharmacological perturbations induced by alloxan.
Nonviral transfection of mammalian cells can be performed with electrostatic complexes (polyplexes) between a plasmid DNA (pDNA) encoding a foreign gene and a cationic polymer. However, an excess of the cationic polymer is required for pDNA condensation and polyplexes formation, which generate in vivo toxicity. Here, we present a new concept of polyplexes preparation aiming to reduce the polymer quantity. pDNA was functionalized with 3,6,9-trioxaundecan-1- {4 - [(2-chloroethyl) ethylamino)] - benzylamino}, 11-azide, and polyethyleneimine (lPEI) with reducible dibenzocyclooctyl (SS-DBCO) groups allowing azide-alkyne cycloaddition between pDNA and lPEI after condensation. The size of polyplexes with DBCO-SS-lPEI was smaller than with lPEI due to a stronger DNA condensation thanks to linkages between polymer and pDNA preventing dissociation until disulfide bridges reduction. In vitro transfection showed that the amount of DBCO-SS-lPEI leading to the most efficient polyplexes was three times lower than lPEI. As expected, toxicity in mice was significantly reduced upon intravenous injection of DBCO-SS-lPEI polyplexes at doses where the lPEI polyplexes killed mice. This is probably due to the high stability of the DBCO-SS-lPEI polyplexes which prevented their aggregation in the pulmonary capillaries. Overall, this new concept of polyplexes with DBCO-SS-lPEI offering the possibility of administering higher doses of polyplexes than lPEI and their ability to pass the pulmonary barrier could be favorably exploited for transfection of distant organs or tissues, such as tumors.
Glucosinolates (GSLs) in Brassica oleracea L. convar. acephala var. viridis (collard) flower, leaf, stem, and root were analyzed qualitatively and quantitatively via their desulfo-counterparts using UHPLC-DAD-MS/MS. Twelve GSLs were identified, including Met-derived GSLs (sinigrin, glucoibervirin, glucoerucin, glucoiberin, glucoraphanin, progoitrin), Trp-derived GSLs (4-hydroxyglucobrassicin, glucobrassicin, 4-methoxyglucobrassicin, and neoglucobrassicin), and Phe-derived GSLs (glucotropaeolin and gluconasturtiin). Total GSL content was highest in the root, having 63.40 μmol/g dried weight (DW), with gluconasturtiin (34.02 μmol/g DW) as the major GSL, followed by sinigrin and glucoibervirin (12.43 and 7.65 μmol/g DW, respectively). Total GSL contents in the flower, leaf, and stem were lower than in root, having 6.27, 2.64, and 1.84 μmol/g DW, respectively, with Trp and/or Met-derived GSLs as the predominant ones. GSL breakdown products were obtained via microwave hydrodiffusion and gravity (MHG) and volatile breakdown products were analyzed using GC-MS techniques. Volatile isolates were tested for their cytotoxic activity using MTT assay. MHG volatile extract from the root demonstrated the best cytotoxic activity against human bladder cancer cell line T24 and breast cancer cell line MDA-MB-231 during an incubation time of 72 h (IC50 21.58, and 11.62 μg/mL, respectively). The activity of the root extract can be attributed to its major volatile, 2-phenylethyl isothiocyanate (gluconasturtiin breakdown product).
As technological innovations gain the capacity to replace human labour, it is increasingly possible that artificial intelligence can lead to higher unemployment rates. This paper is devoted to forecasting unemployment that is based on artificial intelligence as an input of interest by using an artificial neural network learning process. The simulation is performed based on a sample including 23 of the most high-tech and developed economies, over the period from 1998 to 2016. The proposed artificial neural network with one layer and 10 neurons offers good results in terms of unemployment prediction, with an overall coefficient of determination of 0.912. Artificial intelligence input is a top contributor to the prediction of unemployment, along with foreign direct investment, total population, labour productivity, and lagged unemployment. Inflation and government size register a modest contribution. This suggests that forecasts that include this new variable will be more accurate.
Interstellar scattering (ISS) of radio pulsar emission can be used as a probe of the ionised interstellar medium (IISM) and causes corruptions in pulsar timing experiments. Two types of ISS phenomena (intensity scintillation and pulse broadening) are caused by electron density fluctuations on small scales (< 0.01 AU). Theory predicts that these are related, and both have been widely employed to study the properties of the IISM. Larger scales (∼1-100 AU) cause measurable changes in dispersion and these can be correlated with ISS observations to estimate the fluctuation spectrum over a very wide scale range. IISM measurements can often be modeled by a homogeneous power-law spatial spectrum of electron density with the Kolmogorov (−11/3) spectral exponent. Here we aim to test the validity of using the Kolmogorov exponent with PSR J0826+2637. We do so using observations of intensity scintillation, pulse broadening and dispersion variations across a wide fractional bandwidth (20 – 180 MHz). We present that the frequency dependence of the intensity scintillation in the high frequency band matches the expectations of a Kolmogorov spectral exponent but the pulse broadening in the low frequency band does not change as rapidly as predicted with this assumption. We show that this behavior is due to an inhomogeneity in the scattering region, specifically that the scattering is dominated by a region of transverse size ∼40 AU. The power spectrum of the electron density, however, maintains the Kolmogorov spectral exponent from spatial scales of 5× 10−6 AU to ∼100 AU.
The foremost objective of this work is to assess the microcapsules composition (polymer-based and polymer/clay-based) effect, on the release of rosemary essential oil into w/o medium and evaluate their antioxidant activity. Calcium alginate (CA) and calcium alginate/montmorillonite hybrid (CA-MTN) microcapsules were developed following an ionotropic crosslinking gelation and were used as host materials for the encapsulation of rosemary essential oil. The unloaded/loaded CA and hybrid CA-MTN microcapsules were characterized by Fourier transform infra-red (FT-ATR) spectroscopy, thermal analysis (TGA), scanning electron microscopy (SEM) and DPPH assay. The evaluation of the microcapsule's physicochemical properties has shown that the clay filling with montmorillonite improved the microcapsule's properties. The encapsulation efficiency improved significantly in hybrid CA-MTN microcapsules and exhibited higher values ranging from 81 for CA to 83% for hybrid CA-MTN and a loading capacity of 71 for CA and 73% for hybrid CA-MTN, owing to the large adsorption capacity of the sodic clay. Moreover, the hybrid CA-MTN microcapsules showed a time-extended release of rosemary essential oil compared to CA microcapsules. Finally, the DPPH assay displayed a higher reduction of free radicals in hybrid CA-MNT-REO (12.8%) than CA-REO (10%) loaded microcapsules. These results proved that the clay-alginate combination provides microcapsules with enhanced properties compared to the polymer-based microcapsules.
Institution pages aggregate content on ResearchGate related to an institution. The members listed on this page have self-identified as being affiliated with this institution. Publications listed on this page were identified by our algorithms as relating to this institution. This page was not created or approved by the institution. If you represent an institution and have questions about these pages or wish to report inaccurate content, you can contact us here.
2,377 members
Eva Kovacevic
  • Groupe de Recherches sur l'Energétique des Milieux Ionisés (GREMI)
Cem Ertur
  • Laboratoire d'Economie d'Orléans
François Bernard
  • Laboratoire de Physique et Chimie de l'Environnement et de l'Espace LPC2E
sébastien Limet
  • Laboratoire d'Informatique Fondamentale d'Orléans (LIFO)
Gisèle Krysztofiak Tong
  • Département de Chimie
Université d'Orléans - Rue de Chartres BP6759, 45067, Orléans, Centre, France
+33 (0) 2 38 41 71 71
+33 (0) 2 38 41 71 71