HAL Portal usj Université Saint-Joseph de Beyrouth-Liban
Not a member yet
1220 research outputs found
Sort by
Evapotranspiration in the Amazon Basin: Couplings, hydrological memory and water feedback
No full textInternational audienc
Unveiling the organic chemical composition and sources of organic carbon in PM2.5 at an urban site in Greater Cairo (Egypt): A comprehensive analysis of primary and secondary compounds
No full textInternational audienceThis work presents an exhaustive chemical characterization of the organic fraction of fine particulate matter (PM 2.5 ) collected at an urban site in the Greater Cairo Area, Egypt, one of the most polluted megacities in the world. An intensive 2-month sampling campaign was conducted at an urban site in Giza (Dokki), from November 26, 2019, to January 28, 2020. Daily (24-h integrated) PM 2.5 filter samples were then analyzed for their carbonaceous (OC, EC) and organic fractions including primary (n-alkanes, phthalates, fatty acids, polycyclic aromatic hydrocarbons, hopanes, sugars, and sugar alcohols) and secondary (isoprene and β-caryophyllene oxidation products, and dicarboxylic acids) compounds. Average organic (OC) and elemental carbon (EC) concentrations were 17.8 ± 6.6 μg/m 3 and 4.4 ± 1.5 μg/m 3 , respectively. Biomass burning was confirmed by high daily concentration levels of levoglucosan, mannosan, and galactosan (sum equals to 288 ng/m 3 ). Road traffic was also highlighted by the relative abundance of tetracosane and a carbon preference index close to unity as well as by the concentration ratios of PAHs and hopanes. Moreover, phthalates were identified for the first time in Cairo with high concentrations (654 ng/m 3 ) that might be attributable to open waste burning activities. Fatty acids and sugars were also investigated and assigned to cooking activities and primary biogenic sources, respectively. The average concentration of isoprene and β-caryophyllene oxidation products were 0.89 ± 0.83 ng/m 3 , and 0.01 ± 0.02 ng/m 3 , respectively. These low values are expected since no pine trees or even forests exist in Egypt. The macrotracer approach was employed alongside Monte Carlo simulation to identify sources of primary OC and evaluate the uncertainties associated with source attribution and OC reconstruction. The findings revealed a strong contribution from cooking (31% of observed OC) and biomass burning (18%), with median reconstructed OC levels showing significant uncertainty (64%) as expected.</div
Experimental approach for IR-UWB Radar-Based people detection in Industry 4.0 environments
No full textInternational audienceAn experimental investigation of people detection in Industry 4.0 environments, using impulse radio ultra-wideband signals, is described in this paper. Given the specific characteristics of the considered indoor environment and signals of interest, we first address clutter reduction, and then propose a two-paths signal processing architecture for constant false alarm rate (CFAR) detection of moving and stationary people, using matched filtering and Doppler focusing, respectively. A statistical study of the residual clutter and noise is carried out, and optimal threshold values are derived for these two use cases. The performance of the two CFAR detectors is then assessed using simulated data for different signal-to-noise ratios (SNR) and false alarm probabilities. Finally, their detection capabilities are explored using real data, measured in a heavily cluttered Industry 4.0 indoor environment, for a specially designed scenario with a person alternating between stop and motion phases.</div
Screening for Cognitive Impairment in Bilinguals: What Is the Influence of the Language of Assessment?
No full textInternational audienceBackground: Bilingualism’s impact on cognitive assessment remains underexplored. This study analyzes the efficacy of the Mini-Mental State Examination (MMSE) as a screening tool for bilinguals, specifically examining the influence of language choice on balanced and unbalanced Lebanese bilinguals (Arabic-French) and its implications for diagnosing cognitive impairment. Methods: Ninety-three bilingual healthy controls (mean age = 67.99 ± 9.3) and 29 Alzheimer’s disease patients (mean age = 77.2 ± 5.9), including 26 with mild and 3 with moderate dementia, underwent MMSE assessments in both Arabic and French. The study aimed to assess language impact on cognitive screening outcomes in different bilingual subtypes. Results: Sensitivity in screening for cognitive impairment using the MMSE varied based on language and bilingualism subtype. For unbalanced bilinguals, using the prominent language increased sensitivity. Conversely, in balanced bilinguals, employing the societal majority language enhanced sensitivity. This suggests that the conventional use of the non-prominent language in cognitive screening for foreigners/immigrants may result in a subtle loss of MMSE sensitivity. Conclusion: This study emphasizes the critical role of language choice in cognitive assessment for bilinguals. The MMSE’s sensitivity is influenced by language selection, with clinical implications for screening procedures. Recommendations include using the prominent language for cognitive screening in dominant bilinguals and the societal majority language for balanced bilinguals. This nuanced approach aims to improve the accuracy and cultural sensitivity of cognitive screening in bilingual populations, addressing the gap in current assessment practices.Dépistage des troubles cognitifs chez les individus bilingues : quelle est l’influence de la langue d’évaluation ? Contexte : L’impact du bilinguisme de patients sur leur évaluation cognitive demeure sous-exploré. Cette étude entend donc analyser l’efficacité du test de Folstein (TF ou Mini-Mental State Examination ) en tant qu’outil de dépistage chez des individus bilingues en examinant plus particulièrement l’influence du choix de la langue chez des individus d’origine libanaise dont le bilinguisme (arabe et français) est équilibré et non équilibré de même que les implications sous-jacentes en vue d’un diagnostic de troubles cognitifs. Méthodes : Au total, 93 témoins en santé et bilingues (âge moyen = 67,99 ± 9,3), ainsi que 29 patients atteints de la maladie d’Alzheimer (âge moyen = 77,2 ± 5,9), dont 26 souffraient de démence légère et 3 de démence modérée, ont subi un TF en arabe et en français. Notre étude visait donc à évaluer l’impact de la langue sur les résultats du dépistage cognitif dans différents sous-types d’individus bilingues. Résultats : La sensibilité du dépistage de troubles cognitifs à l’aide du TF a varié en fonction de la langue et du sous-type d’individus bilingues. Chez les individus bilingues « déséquilibrés », l’utilisation de la langue dominante a augmenté le niveau de sensibilité du test. Inversement, chez les bilingues « équilibrés », l’utilisation de la langue majoritaire de la société a augmenté la sensibilité. Cela suggère en somme que l’utilisation conventionnelle de la langue non dominante dans le dépistage cognitif des étrangers ou des immigrants peut entraîner une perte subtile de sensibilité du TF. Conclusion : Cette étude souligne en définitive le rôle essentiel du choix de la langue dans l’évaluation cognitive des individus bilingues. La sensibilité du TF est en effet influencée par le choix de la langue, ce qui a des implications cliniques pour les procédures de dépistage. Voilà pourquoi il est recommandé d’utiliser la langue dominante pour le dépistage cognitif effectué chez des individus bilingues « déséquilibrés » et la langue majoritaire de la société chez des individus bilingues « équilibrés ». En comblant les lacunes des pratiques actuelles d’évaluation, cette approche nuancée entend améliorer la précision et la sensibilité culturelle du dépistage cognitif au sein de populations bilingues
Global Sagittal Angle and T9-tilt seem to be the most clinically and functionally relevant global alignment parameters in patients with Adult Spinal Deformity
No full textInternational audienceIntroductionRadiographic analysis is necessary for the assessment and the surgical planning in adults with spinal deformity (ASD). Restoration of global alignment is key to improving patient's quality of life. However, the large number of existing global alignment parameters can be confusing for surgeons.Research questionTo determine the most clinically and functionally relevant global alignment parameters in ASD.Material and methodsASD and controls underwent full body biplanar X-ray to calculate global alignment parameters: odontoid to hip axis angle (OD-HA), global sagittal angle (GSA), global tilt (GT), SVA, center of auditory meatus to hip axis (CAM-HA), SSA, T1-tilt and T9-tilt. All subjects filled HRQoL questionnaires: ODI, SF-36, VAS for pain and BDI (Beck's Depression Inventory). 3D gait analysis was performed to calculate kinematic and spatio-temporal parameters. A machine learning model predicted gait parameters and HRQoL scores from global alignment parameters.Results124 primary ASD and 47 controls were enrolled. T9 tilt predicted the most BDI (31%), hip flexion/extension during gait (36%), and double support time (39%). GSA predicted the most ODI (26%), thorax flexion/extension during gait (33%), and cadence (36%).Discussion and conclusionAmong all global alignment parameters, GSA, evaluating both trunk shift and knee flexion, and T9 tilt, evaluating the shift of the center of mass, were the best predictors for most of HRQoL scores and gait kinematics. Therefore, we recommend using GSA and T9 tilt in clinical practice when evaluating ASD because they represent the most quality of life and functional kinematic of these patients
Is a White Diet Necessary for Tooth Bleaching Procedures? A Systematic Review and Meta-Analysis
No full textThe aim of this investigation was to conduct a systematic review and meta-analysis to determine the necessity of a white diet during or following a bleaching procedure. This systematic review and meta-analysis followed the PRISMA guidelines meticulously. The research question was: Is a white diet necessary during and/or after a bleaching treatment? In vitro studies or clinical trials reporting the color change in bleached enamel after the use of a free-staining diet were considered for full-text review. For the analyses, a random-effects model was employed. Statistical significance was defined as a p-value < 0.05. A total of 17 documents were eligible for qualitative analysis: 5 clinical trials and 12 in vitro studies. Only data from the clinical trials were included in the meta-analysis. For at-home bleaching, differences in the color among the subjects were not statistically significant during the first (p = 0.64), second (p = 0.26) or third (p = 0.43) weeks of treatment. Also, the color difference one month after finishing the bleaching treatment were not statistically significant (p = 0.27). The color difference one month after finishing an in-office treatment showed that the restrictions on diet did not significantly improve the bleaching outcomes (p = 0.90). According to the findings of this review, dietary restrictions are not necessary during or after bleaching procedures
Investigating the industrial origin of terpenoids in a coastal city in northern France: A source apportionment combining anthropogenic, biogenic, and oxygenated VOC
No full textInternational audienceTerpenoids have long been known to originate from natural sources. However, there is growing evidence for emissions from anthropogenic activities in cities, in particular from the production, manufacturing, and use of household solvents. Here, as part of the DATAbASE (Do Anthropogenic Terpenoids mAtter in AtmoSpheric chEmistry?) project, we investigate for the first time the potential role of industrial activities on the terpenoid burden in the urban atmosphere. This study is based on continuous VOC observations from an intensive field campaign conducted in July 2014 at an industrial-urban background site located in Dunkirk, Northern France. More than 80 VOCs including oxygenated and terpenoid compounds were measured by on-line Thermal Desorption Gas Chromatography with a Flame Ionization Detection (TD-GC-FID) and Proton Transfer Reaction-Time of Flight Mass Spectrometry (PTR-ToFMS). Isoprene, α-pinene, limonene and the sum of monoterpenes were the terpenoids detected at average mixing ratios of 0.02 ± 0.02 ppbv, 0.02 ± 0.02 ppbv, 0.01 ± 0.01 ppbv and 0.03 ± 0.05 ppbv, respectively. Like other anthropogenic VOCs, the mixing ratios of terpenoids significantly increase downwind the industrial plumes by one order of magnitude. Positive Matrix Factorization (PMF) was performed to identify the different emission sources of VOCs and their contribution. Six factors out of the eight factors extracted (r2 = 0.95) are related to industrial emissions such as solvent use, chemical and agrochemical storage, metallurgy, petrochemical, and coal-fired industrial activities. From the correlations between the industrial-type PMF factors, sulfur dioxide, and terpenoids, we determined their emissions ratios and we quantified for the first time their industrial emissions. The highest emission ratio is related to the alkene-dominated factor and is related to petrochemical, metallurgical and coal-fired industrial activities. The industrial emissions of monoterpenes equal 8.1 ± 4.3 tons/year. Those emissions are as significant as the non-industrialized anthropogenic ones estimated for the Paris megacity
A posteriori error estimate for the non-stationary concentration equation coupled with the Darcy system discretized by the Raviart-Thomas finite element
No full textInternational audienceThis article focuses on discretizing the convection-diffusion-reaction equation (concentration or heat), which is time-dependent and coupled with the Darcy equation. The Darcy system is discretized using the Raviart-Thomas finite element, while the concentration equation is discretized using the Lagrange finite element of order one in space and the Euler method in time. We present optimal a posteriori error estimates utilizing two computable error indicators: linearization and discretization indicators. Ultimately, numerical experiments demonstrate and confirm the efficacy of the proposed method, and show comparisons with previous works
Evolution of carbapenemase-producing Enterobacterales over a 5-year period: worrying increase in acquired cases and patients residing abroad
No full textEvolution of the optical scattering properties of blood plasma during clot formation
No full textInternational audienceVenous thromboembolism (VTE) is a common and serious disease which encompasses deep vein thrombosis (DVT) and pulmonary embolism (PE). DVT is created when a blood clot forms in the deep veins of the leg and when the clot migrates through the bloodstream, to lung arteries, it creates a PE. VTE is the third cardiovascular cause of death overall and is responsible for 30000 annual deaths in Europe. After biological and clinical investigation, nearly half of VTE cases have no known origin (idiopathic VTE). Among the patients developing idiopathic VTE, about 30% of them would have a recurrent thromboembolic event, 70% would not be subjected to any recurrence. A balance must be struck between the risks of recurrent thrombosis if anticoagulant treatment is stopped versus the risks of bleeding associated with continued anticoagulation therapy that can go up to the course of decades. The search for new biomarkers allowing to best stear the treatment of patients is thus of major interest. Recent studies seem to link clot's structure to a risk of recurrence. The aim of our work is to develop a sensitive optical method, in order to help with VTE patient's prognosis, measuring the evolution of the scattering coefficient of a plasma during ex vivo clot formation.</div