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Effect of a Thermomechanical Pretreatment Coupled to Sulfuric Acid or Sodium Hydroxide Catalysis on Physicochemical Properties and Enzymatic Hydrolysis of Alfa Fibers (Stipa tenacissima L.)
No full textInternational audienc
Carbon-13-isotopomics and metabolomics of fatty acids from triacylglycerols: overcoming the limitations of GC-C-IRMS for short- and medium-acyl chains
No full textInternational audienceCarbon-13 isotopomics of triacylglycerol (TAG) fatty acids or free fatty acids in biological matrices holds considerable potential in food authentication, forensic investigations, metabolic studies, and medical research. However, challenges arise in the isotopic analysis of short- and medium-chain (C4 to C10) fatty acid methyl esters (SMCFAMEs) through gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). The high volatility of these esters results in losses during their preparation, leading to isotopic fractionation. Moreover, the methoxy group added to acyl chains requires the correction of δ13C values, thereby increasing the uncertainty of the final results. Analyzing free fatty acids (FFAs) addresses both issues encountered with SMCFAMEs. To achieve this objective, we have developed a new protocol enabling the isotopomics of individual fatty acids (FAs) by GC-C-IRMS. The same experiment also provides the FA profile, i.e., the relative percentage of each FA in the TAG hydrolysate or its concentration in the studied matrix. The method exhibited high precision, as evidenced by the repeatability and within-lab reproducibility of results when tested on TAGs from both animal and vegetal origins. Compared to the analysis of FAMEs by GC-C-IRMS, the current procedure also brings several improvements in alignment with the principles of green analytical chemistry and green sample preparation. Thus, we present a two-in-one method for 13C-isotopomic and metabolomic biomarker quantitation within quasi-universal TAG compounds, encompassing the short- and medium-acyl chains
Genomic insights into epidemic plasmids carrying bla CTX-M and mcr-1 genes in Escherichia coli from Lebanese broiler production
No full textInternational audienceBackground In a previous nationwide survey in the Lebanese broiler production, multidrug-resistant CTX-M-producing E. coli were found to carry the mobile colistin resistance gene mcr-1. Objectives To investigate the mobile genetic supports responsible for the spread of these resistance genes among E. coli in healthy broilers in Lebanon. Methods Thirty-three blaCTX-M and mcr-1 positive E. coli of various sequence types from 17 broilers farms were subjected to conjugation assays. Long-read sequencing (Oxford Nanopore Technologies) and hybrid assembly were performed to determine complete plasmid sequences and their phylogenetic diversity. Results Twenty-nine conjugative IncFII plasmids harboured the extended-spectrum β-lactamase genes blaCTX-M-3 (n = 25) or blaCTX-M-55 (n = 4). Highly related IncF2:A-:B-/blaCTX-M-3 plasmids differing only through IS-mediated genetic rearrangements in antibiotic resistance gene clusters were found in genetically diverse E. coli strains isolated from distant farms. The mobile colistin resistance genes mcr-1.1 and mcr-1.26 were carried by IncX4 and IncI2 plasmids. Worryingly, in one isolate, the ISEcp1-blaCTX-M-55 transposable unit was found integrated in a mcr-1.26-carrying IncX4 plasmid. Beside expanded cephalosporins and colistin resistances, all E. coli isolates were multidrug-resistant with different additional resistances against aminoglycosides, (fluoro)quinolones, fosfomycin, phenicols, sulphonamides, tetracycline and trimethoprim. Conclusions Closely related blaCTX-M-3/55-borne IncF2:A-:B- plasmids harbouring variable MDR regions and mcr-1 carrying IncX4 plasmids are widely disseminated in the E. coli population of healthy broilers in Lebanon. Further surveillance programmes of antimicrobial resistance and interventions to reduce the abusive use of medically important antibiotics are necessary to limit the spread of resistances in food-producing animals in Lebanon
Journées d'études : "Archives, Empreintes, Mémoires", Université Saint-Joseph de Beyrouth, 14-15 décembre 2023
No full textInternational audienceCompte rendu des journées d'étude "Archives, Empreintes, Mémoires", dirigées par Ghada Sayegh et Valérie Vignaux à l'IESAV
Construction et déconstruction des mythes de fondation de l’Ouest américain au cinéma. Sur quatre plans iconiques du Western. Stagecoach , The Ox-Bow Incident , The Searchers , Once Upon a Time in the West
No full textInternational audienceThis study seeks to understand, through analysis of four shots taken from four different westerns, the syntactic and historical evolution of a genre, its discourse and its ideology, via the apparent immutability of its semantic elements — narrative, formal and iconographic. Based on a comparative analysis of four shots taken from Stagecoach (Ford, 1939), The Searchers (Ford, 1957), The Ox-Bow Incident (Wellman, 1942) and Once Upon a Time in the West (Leone, 1968), the study incorporates several approaches: generic, formalist and pragmatic. It starts with the genre and some of its dramatic and aesthetic conventions and determines, its impact in specific sociocultural contexts and the means of its transformations based on what American historiography underwent in terms of radical changes.Cette étude cherche à saisir, à travers l’analyse de quatre plans extraits de quatre westerns différents, l’évolution syntaxique et historique d’un genre, de ses discours et de son idéologie, à travers l’apparente immuabilité de ses éléments sémantiques – narratifs, formels ou iconographiques. À partir de l’analyse comparative de quatre plans tirés de Stagecoach (Ford, 1939), de The Searchers (Ford, 1957), de The Ox-Bow Incident (Wellman, 1942) et de Once Upon a Time in the West (Leone, 1968), l’étude s’inscrit au confluent de plusieurs approches, aussi bien générique, formaliste que pragmatique. Elle part du genre et de certaines de ses conventions dramatiques et esthétiques pour déterminer, à travers les jeux parfois improbables, mais passionnants, de l’interprétation, son impact dans des contextes socioculturels déterminés et les modalités de ses transformations en fonction de ce que l’historiographie américaine a connu de modifications radicales
Kinematic limitations during stair ascent and descent in patients with adult spinal deformity
No full textInternational audienceBackground: Adults with spinal deformity (ASD) are known to have spinal malalignment, which can impact their quality of life and their autonomy in daily life activities. Among these tasks, ascending and descending stairs is a common activity of daily life that might be affected.Research question: What are the main kinematic alterations in ASD during stair ascent and descent?Methods: 112 primary ASD patients and 34 controls filled HRQoL questionnaires and underwent biplanar X-from which spino-pelvic radiographic parameters were calculated. Patients were divided into 3 groups: 44 with sagittal malalignment (ASD-Sag: PT > 25°, SVA>5 cm or PI-LL>10°), 42 with isolated thoracic hyperkyphosis (ASD-HyperTK: TK > 60°), 26 with isolated frontal spine deformity (ASD-Front: Cobb>20°). All participants underwent 3D motion analysis of the whole body while ascending and descending a stair step from which kinematic waveforms were extracted.Results: During stair ascent, ASD-Sag exhibited an increased thorax flexion (20 vs 5°), a decreased lumbar lordosis L1L3-L3L5 (7 vs 14°), and an increased ROM of lumbo-pelvic joint (15 vs 10°, all p < 0.05), compared to controls. Similar compensations were shown while descending the stairstep. ASD-HyperTK had similar kinematic limitations as ASD-Sag but to a lesser extent. ASD-Front had normal kinematic patterns. PCS-SF36 correlated to thorax flexion (r = -0.45) and ODI was correlated to pelvic tilt ROM (r = 0.46).Discussion and conclusion: ASD subjects with sagittal malalignment tend to ascend and descend stairs with increased thorax flexion, making them more prone to falls. Compensation mechanisms occur at the head and lumbo-pelvic levels to maintain balance and avoid falling forward
Comparative Review on the Production and Purification of Bioethanol from Biomass: A Focus on Corn
No full textInternational audienceIn the contemporary era, conventional energy sources like oil, coal, and natural gas overwhelmingly contribute 89.6% to global CO2 emissions, intensifying environmental challenges. Recognizing the urgency of addressing climate concerns, a pivotal shift towards renewable energy, encompassing solar, wind, and biofuels, is crucial for bolstering environmental sustainability. Bioethanol, a globally predominant biofuel, offers a versatile solution, replacing gasoline or integrating into gasoline–ethanol blends while serving as a fundamental building block for various valuable compounds. This review investigates the dynamic landscape of biomass generations, drawing insightful comparisons between the first, second, third, and fourth generations. Amid the drive for sustainability, the deliberate focus on the initial generation of biomass, particularly corn, in bioethanol production is grounded in the current dependence on edible crops. The established utilization of first-generation biomass, exemplified by corn, underscores the necessity for a comprehensive examination of its advantages and challenges, allowing for a nuanced exploration of existing infrastructure and practices. To produce bioethanol from corn feedstock, various milling methods can be employed. Thus, this paper delves into a comparative assessment of dry-milling and wet-milling processes scrutinizing their efficiency, environmental impact, and economic feasibility
3D external shape analysis and barycentremetry can provide early signs of progression in adolescent idiopathic scoliosis
No full textInternational audiencePurposeOur objective was to analysis the barycentremetry, obtained from the external envelope reconstruction of biplanar radiographs, in adolescent idiopathic scoliosis (AIS) and to determine whether assessing would help predict the distinction between progressive and stable AIS at the early stage.MethodsA retrospective study with a multicentre cohort of 205 AIS was conducted. All AIS underwent a biplanar X-ray between 2013 and 2020. Inclusion criteria were Cobb angle between 10° and 25°; Risser sign lower than 3; age higher than 10 years; and no previous treatment. A 3D spine reconstruction was performed, and the barycentremetry parameters were computed, i.e., the center of mass position at the apex and the axial torque at the apex, the upper and lower junction. A severity index, helping to distinguish stable and progressive AIS, was computed on the first radiograph, and weighted according to these parameters. A clinical and radiographic monitoring determined if AIS were classified such a stable or progressive scoliosis.ResultsOne hundred and sixty-two AIS were included (i.e., 87 were classified as stable and 75 as progressive). The apex center of mass position was different between the stable and progressive AIS groups (6 mm, SD = 4 mm for the whole cohort; 5 mm, SD = 4 mm for stable AIS versus 7 mm, SD = 4 mm for progressive AIS; p = 0.02). In AIS thoracic, the specificity and positive predictive value of the severity index increased by 19% and 16%, respectively, by adding the apex vertebral axial torque.ConclusionEarly assessment of the external envelope from biplanar X-ray reconstruction of idiopathic scoliosis showed that the apex centre of mass position was significantly different between progressive and stable scoliosis. The inclusion of the axial torque of the apex vertebra in the severity index is promising to help the clinician distinguish between stable and progressive thoracic AIS at an early stage
A Posteriori Error Estimates for Darcy-Forchheimer’s Problem Coupled with the Convection-Diffusion-Reaction Equation
No full textInternational audienceIn this work we derive a posteriori error estimates for the convection-diffusion-reaction equation coupled with the Darcy-Forchheimer problem by a nonlinear external source depending on the concentration of the fluid. We introduce the variational formulation associated to the problem, and discretize it by using the finite element method. We prove optimal a posteriori errors with two types of calculable error indicators. The first one is linked to the linearization and the second one to the discretization. Then we find upper and lower error bounds under additional regularity assumptions on the exact solutions. Finally, numerical computations are performed to show the effectiveness of the obtained error indicators
Hydrological Characterization of Mediterranean Catchments
No full textThis article is part of the special issue“IAHS2022 – Hydrological sciences in the Anthropocene: Variabil-ity and change across space, time, extremes, and interfaces”. It is a result of the XIth Scientific Assembly of the International Association of Hydrological Sciences (IAHS 2022), Montpellier, France, 29 May–3 June 2022International audienceA climatic, physiographic, and hydrological homogeneity across the Mediterranean has been detected but not yet confirmed. Mediterranean climate is known for its precipitation seasonality and the alternation of humid winters and dry summers which conditions rivers flow regimes, landcover, agriculture and consequently any water resources management plan. Several physiographic traits could be also observed across the Mediterranean, like the elevated and exposed karstic features, and the cultivated and managed areas. Hydrologically, global river regimes were classified based on monthly average flows only, and Mediterranean regimes were identified under 3 of Haines' 15 global classes with a clear relation to Köppen's Mediterranean climate. Thus, we first studied the flow regimes of 55 Mediterranean catchments to verify if Mediterranean rivers fall into same regime class. Second, we characterized the Mediterranean hydrological response through different water balance functional models as advanced by Budyko, L'vovich and elaborated by Ponce & Shetty and Sivapalan. The water balance analysis highlighted the Mediterranean trend following the general climatic setting from the wet Northern region to the arid Southern region; it also showed hydrological homogeneity for mountainous karstic, and snow influenced catchments which yield the highest baseflows and runoff coefficients, especially if located in moderate climate