Étude de la contamination de la côte libanaise par les hydrocarbures aromatiques polycycliques (HAPs) et les éléments traces métalliques (ETMs) : archives sédimentaires et biomonitoring suite à une marée noire

This research project aims at the study of the contamination of the Lebanese coast by PAHs, DDE, Hg and Pb. The research work is divided into two distinct parts concerning two environmental compartments (sedimentary and biological) and it addresses different questions and approaches. In the first part, the study of a dated sediment core raised from the continental shelf in southern Lebanese coast allowed reconstructing the contamination history in the Levantine basin. The contaminants’ analysis as well as 210Pb and 137Cs datation allowed obtaining a reliable record of mercury, lead and PAHs sedimentary deposition in the Lebanese continental margin in the Levantine basin. Although concentrations and fluxes are relatively low, a two-phase increase of concentration is found using C1 core sedimentary profiles. Coal was identified as the main source of Pb, Hg and PAHs in the Levantine basin between the mid 19th and the mid 20th century. Ratios of Pb stable isotopes and PAH diagnostic ratios support this assumption. The studied sedimentary archives provide also information on the deposition of contaminants on a global scale possibly related to atmospheric emissions mainly from Central and Eastern Europe. In the second part of the thesis, the study of contamination by PAHs of the Lebanese coast was undertaken following an oil spill in the south of Lebanon, which occurred after the bombardment by the Israeli military of the electric power plant in Jiyeh in 2006. We have set-up a biomonitoring program with an invasive mussel specie Brachidontes variabilis over a three-year study. Results indicate a progressive decrease of PAH concentrations in the intertidal ecosystem of the Lebanese coast. Contamination of the subtidal zone in 2007 by Jiyeh fuel oil was significantly lower. However, Jiyeh fuel oil signature was still detectable in mussel tissues even three years after the oil spill. Contamination was found to be particularly persistent in some of the highly oiled sites. It appears that pre-spill state was still not reached even three years following the oil spill. Detailed investigation of spatio-temporal changes of intertidal mussels contamination by PAH is also presented in this part of the thesis.Ce projet de recherche porte sur l’étude de la contamination de la côte libanaise par les composés organiques (HAP, DDE) et par les éléments-trace métalliques (Hg, Pb principalement). Les travaux sur les compartiments sédimentaires et biologiques de la côte libanaise constituent deux parties aux problématiques et aux approches distinctes autour desquelles s’articule cette thèse. Dans la première partie, l’analyse d’une carotte sédimentaire datée prélevée sur le plateau continental du Sud du Liban a permis de reconstituer l’historique de contamination dans le bassin Levantin. Les analyses de contaminants dans les sédiments de la carotte C1 combinés à la datation aux 210Pb et 137Cs ont permis d’obtenir un enregistrement fiable des variations du dépôt de mercure, de plomb et de HAP sur le plateau continental libanais, dans le bassin Levantin. Bien que les concentrations et les flux soient relativement faibles, une augmentation en deux phases des concentrations est bien mise en évidence par le profil sédimentaire de C1. Le charbon est identifié comme source principale de Pb, de Hg et de HAP dans le bassin Levantin entre la moitié du 19ème siècle et la moitié du 20ème siècle. Les résultats des ratios isotopiques du Pb et des ratios diagnostiques de HAP appuient ce constat. Les archives sédimentaires dans la carotte C1 fournissent un signal du dépôt de contaminants à l’échelle globale probablement lié aux sources d’émissions atmosphériques en provenance d’Europe Centrale et de l’Est. Dans la seconde partie, une étude de la contamination par les HAP du littoral libanais est menée suite à la marée noire résultant du conflit armé israélo-libanais en 2006. Une approche de biomonitoring sur trois ans utilisant l’espèce de moules invasives Brachidontes variabilis a été développée. Les résultats indiquent une décroissance progressive des concentrations de HAP dans l’écosystème intertidal du littoral libanais. La contamination par les HAP du fioul en zone subtidale en 2007 est nettement plus faible. Cependant la signature des HAP dans les tissus de moules prélevées trois ans après la marée noire indique toujours la présence des composés du fioul de Jiyeh. La contamination est particulièrement persistante dans certaines zones fortement touchées par la nappe de fioul en 2006. Il apparaît que l’état initial pré-marée noire n’a pas été atteint, même trois ans après la marée noire de Jiyeh. L’examen détaillé de l’évolution spatiale et temporelle de la contamination par les HAP de l’environnement intertidal est présenté dans ce volet de notre étude

Lebanese Internal Security Forces (ISF) Reform

The purpose of this study is to develop and implement a model of policing based on partnership with the community aimed at delivering effective policing and increasing trust in the Internal Security Forces of Lebanon (hereinafter ISF), in addition to identifying the challenges facing the reform inside ISF. The research methodology adopted in this study is the qualitative one. We conducted 10 semi-structured interview with 10 top ISF officers, the interviews were one to one interviews, recorded and transcribed. There are a few fundamental ideas that can be implemented that can, by their very nature, enforce ISF reform.  The areas that need attention are officer training, personal characters, better hiring skills, scheduled reviews, monitoring, and an incentives program. Keywords: ISF, Qualitative analysis, Reform, Police corruption, Leadership in Polic

University Image and its Relationship to Student Satisfaction: Case of the Holy Spirit University of Kaslik, Lebanon

This work focuses on the study of the university’s image with the aim of explaining the components of image and attributes of student satisfaction. Our study investigates the relationships between the different components of the university image and to what extent they may affect the students’ satisfaction. Hypotheses were drawn setting the relationships between the affective, cognitive and overall image in relation with satisfaction. The results of the empirical work carried out on a representative sample of 200 students studying at Holy Spirit University of Kaslik (USEK) demonstrate that the cognitive component of image is an antecedent of the affective component. In turn, both of these components influence the formation of the overall image of a university. However, the affective and overall images statistically and significantly affect the overall satisfaction of students with their university. The research could also be extended to cover the area of the Middle East and study the process of formation of the university image by various public universities

Attosecond time-resolved photoelectron holography

Ultrafast strong-field physics provides insight into quantum phenomena that evolve on an attosecond time scale, the most fundamental of which is quantum tunneling. The tunneling process initiates a range of strong field phenomena such as high harmonic generation (HHG), laser-induced electron diffraction, double ionization and photoelectron holography—all evolving during a fraction of the optical cycle. Here we apply attosecond photoelectron holography as a method to resolve the temporal properties of the tunneling process. Adding a weak second harmonic (SH) field to a strong fundamental laser field enables us to reconstruct the ionization times of photoelectrons that play a role in the formation of a photoelectron hologram with attosecond precision. We decouple the contributions of the two arms of the hologram and resolve the subtle differences in their ionization times, separated by only a few tens of attoseconds

On-line PCA with Optimal Regrets

We carefully investigate the on-line version of PCA, where in each trial a learning algorithm plays a k-dimensional subspace, and suffers the compression loss on the next instance when projected into the chosen subspace. In this setting, we analyze two popular on-line algorithms, Gradient Descent (GD) and Exponentiated Gradient (EG). We show that both algorithms are essentially optimal in the worst-case. This comes as a surprise, since EG is known to perform sub-optimally when the instances are sparse. This different behavior of EG for PCA is mainly related to the non-negativity of the loss in this case, which makes the PCA setting qualitatively different from other settings studied in the literature. Furthermore, we show that when considering regret bounds as function of a loss budget, EG remains optimal and strictly outperforms GD. Next, we study the extension of the PCA setting, in which the Nature is allowed to play with dense instances, which are positive matrices with bounded largest eigenvalue. Again we can show that EG is optimal and strictly better than GD in this setting

Perspective Chapter: The Metaverse for Education

Due to ever-evolving teaching methods and technologies, the education sector has undergone and still undergoes several advances. The issue of knowledge creation and application through tutoring has evolved into the primary source of competitive advantage among colleges and a crucial element for success. In a turbulent world full of competitiveness, educational institutions and establishments strive to continuously provide excellence through top-notch education, international partnerships, collaborations, acknowledgments, and accreditations as well as updated technological tools such as e-learning platforms and online labs/workshops, constant investment in each person’s human capital. It is hoped that this would improve people’s knowledge, abilities, experiences, and cultural capital. Our digital lives have advanced quickly over the past two years to the point where living online and offline are now equally important. The purpose of this chapter is to discuss the significance of sustaining education while taking into consideration the undeniable technological advances. This chapter adopts a descriptive/narrative methodology approach. As a result, it can be concluded that, if implemented properly, virtual collaboration and success will become essential skills that professionals across almost all sectors would master. Hence, upcoming research could include the role of the metaverse in education on another aspect of the SGDs like “no poverty.

Does oil price volatility matter for the US transportation industry?

Although the US transport sector is one of the major users of fossil fuel (e.g., crude oil), the impact of energy price volatility on transport stock sector indexes remains under-researched. The present study addresses this research void by investigating the impact of energy implied volatility on transportation stock returns in the US. Using the crude oil volatility index (OVX), as a proxy of energy price volatility, and three Dow Jones indexes tracking the performance of the airlines, marine and trucking stock subsectors, we employ a GARCH-jump model. The main results show that the oil market sends volatility to the US transport subsector stock indexes, suggesting that oil implied volatility plays a role in pricing US transport stocks. The impact of OVX shocks is asymmetric, indicating that increases and decreases in oil implied volatility have a heterogeneous impact on the transport subsector stock markets. Jumps are significant in the three transport subsector stock indexes, and are time-dependent. Notably, the three transportation subsector stock indexes are more sensitive to OVX shocks than the S&P 500 index. These results have important implications for investors, policymakers, academics, and managers of the US transportation industry.© 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).fi=vertaisarvioitu|en=peerReviewed

Direct measurement of Coulomb-laser coupling

The Coulomb interaction between a photoelectron and its parent ion plays an important role in a large range of light-matter interactions. In this paper we obtain a direct insight into the Coulomb interaction and resolve, for the first time, the phase accumulated by the laser-driven electron as it interacts with the Coulomb potential. Applying extreme-ultraviolet interferometry enables us to resolve this phase with attosecond precision over a large energy range. Our findings identify a strong laser-Coulomb coupling, going beyond the standard recollision picture within the strong-field framework. Transformation of the results to the time domain reveals Coulomb-induced delays of the electrons along their trajectories, which vary by tens of attoseconds with the laser field intensity

Nurse’s Wellbeing at Work & Quality Nursing Care: The Case of Hospitals In Lebanon

Our purpose in this research is to find if there is a relationship between the wellbeing at work of nurses in Lebanese hospitals and their quality nursing care. Our study is a correlational study where we will see the correlation between the wellbeing at work and the quality nursing care of nurses at Lebanese hospitals. It is a quantitative study as well. Our sample consists of 160 nurses from 23 hospitals in Lebanon. By using the F test, we showed that there is significance at = 0.05. The quality nursing care Y is dependent on the wellbeing at work of nurses (Xi). Second, while testing for significance using the t Test, we concluded that there is a relationship between the variables Xi. Using the stepwise regression analysis, we kept only two variables (the level of agreement that the work of the nurse has grown more interesting in the last year and the level of agreement that the nurse has enough opportunity to discuss patient problems with colleagues).Finally, using the factor analysis technique (FA), we extracted 4 principal components that explained 78.73% of the variability. The 4 principal components are: Working effectively in a team, Self-image satisfaction, Job satisfaction, and Work Performance.In the last part, we concluded that there is a relationship between the wellbeing at work of nurses in Lebanese hospitals and their quality nursing care. Keywords: Well-being at work, quality-nursing care, Factor Analysis (FA), Principal Component Analysis (PCA), stepwise regression analysis DOI: 10.7176/RHSS/9-24-08 Publication date: December 31st 201

Apatite - Cholesterol Agglomerates in Human Atherosclerotic Lesions

The purpose of this study was to examine the ultrastructural relationships of cholesterol crystals and apatite deposits in human atherosclerotic lesions. Segments of human aortic atherosclerotic lesions were obtained at autopsy , fixed in glutaraldehyde and dehydrated without using any organic solvents. The aortic segments were coated with carbon and subjected to various scanning electron microscope analyses. These included secondary electron imaging, back scattering of primary electrons, energy dispersive X-ray analysis of selected spots followed by area mapping of calcium and phosphorus , and cathodoluminescence. The information gathered from scanning of selected areas in the lesions by all the techniques showed that cholesterol crystals and apatite deposits are close to each other, within 10 μm distance or less. Cholesterol crystals are often surrounded by or adjacent to apatite. The results indicate that cholesterol and apatite crystals form closely linked agglomerates in human atherosclerotic lesions. Further studies are needed to determine whether precipitation of calcium and cholesterol are somehow linked during atherosclerotic lesion development