42 research outputs found
Access of Syrian refugees to COVID-19 testing in Lebanon
Background: Polymerase chain reaction is a well-known method for testing COVID-19 infection, however, refugee populations often face difficulties in accessing testing. Several structural and cultural challenges have hindered access of Syrian refugees to COVID-19 testing in Lebanon, including financial barriers, stigma, and low perception of vulnerability. Aims: To explore barriers to accessing COVID-19 testing by Syrian refugees in Lebanon. Methods: This qualitative study conducted 10 focus group discussions among Syrian refugees and 21 individual semi-structured interviews with healthcare workers. Ethical approval was obtained from the Institutional Review Board of the Lebanese International University, and the study followed the ethical principles of the Declaration of Helsinki. Results: Syrian refugees in Lebanon did not consider COVID-19 testing to be important. Despite the availability of free testing services, psychological, cultural, environmental, and financial barriers hindered them from getting tested. Some of them relied on consultation with pharmacists, who were easy to access and provided symptomatic treatment without the need to test for COVID-19. Fear of stigma, deportation, and isolation were common cultural barriers. Testing was considered unnecessary because of the perception of low disease severity and an attitude of negligence towards preventive practices. The harsh economic and living conditions were of greater concern to the refugees. Conclusion: Findings from this study add to existing literature regarding the social and cultural barriers to COVID-19 testing among Syrian refugees and should be considered when tailoring health promotion campaigns to halt the spread of the COVID-19 pandemic
THE RELATIONSHIP BETWEEN CAFFEINE ADDICTION AND STRESS AMONG LEBANESE MEDICAL STUDENTS IN LEBANON
Stress and behavioral addiction are becoming major health problems growing in strength and prevalence. They are often associated with a large array of debilitating diseases and conditions including psychosocial impairments. Medical students remain a vulnerable territory for developing stress and addiction mainly relating to caffeine consumption. Methods: A cross-sectional design was utilized in this study. Results: The study revealed that academic and learning issues are the most stressful and alarming levels of caffeine dependence. Conclusions: This showed a high impact of academic issues on medical students stress and performance, which mandates thorough actions to be considered by both medical institutions and medical students to fight this stress and maintain a healthier life and academic development
Electromagnetic jet for characterization applications
This comparative study allows to evaluate the performance of an
electromagnetic jet to determine the electromagnetic response of materials,
without being in usual far field conditions. In this work, the reflection
coefficient of a substrate with ground plane, calculated analytically, is
compared with that determined in simulation by the electromagnetic jet. The
results show a satisfactory agreement after calibrating the simulated
reflection coefficient at the focal point of the jet. Thus, we were able to
find, by a local measurement, data consistent with a classical free space type
measurement.Comment: in French language. 17{\`e}mes Journ{\'e}es de Caract{\'e}risation
Microondes et Mat{\'e}riaux, Laboratoire GREMAIN; CEA Le Ripault, Apr 2023,
TOURS, Franc
Knowledge, attitude and practices related to COVID-19 among young Lebanese population
Background: As the world faces the most serious and widespread pandemic in recent history, claiming nearly 1,945,610 lives and infecting over 90 million individuals up to January 13, 2021, controlling the spread of COVID-19 is still limited to efforts done by the general population implementing rules and restrictions passed by world governments and organizations. As we wait for the approved vaccines to become widely distributed, the best approach to fighting the spread of this disease is mostly preventative depending largely on individuals' compliance. This study aimed to determine the knowledge, attitude and practices (KAP) towards COVID-19 in Lebanon. Methods: A descriptive analysis was performed to describe the outcome measures of knowledge, attitudes and practices towards COVID-19 on a convenience sample from the Lebanese population in relation to socio-demographic characteristics and level of concern towards COVID-19. One thousand eight hundred sixty-one participants filled in an online survey (response rate: 18.5%) distributed by social media to social networks of the research team members. Results: Participants were mainly young (49.4% between 18 and 24 years) and males (73.7%). Participants showed an overall appropriate knowledge of COVID-19 (67.1%) and positive attitude (around 90% were optimistic about treatment and vaccination) and had good preventive practices towards COVID-19 (around 75% washed hands and avoided public places). Knowledge and practices correlated positively with marriage, age, education, working in a healthcare field and with the level of concern about getting COVID-19. Conclusions: This study found good overall levels of KAP among the studied Lebanese population. This can help in controlling the spread of COVID-19 if individuals were forced to adhere to social distancing and appropriate preventative practices.Scopu
Assessing the Psychometric Properties of the Internet Addiction Test (IAT) Among Lebanese College Students
Internet addiction is an emergent problem; yet, both a strong conception of the factors precipitating challenging activities and a gold standard tool for evaluating symptoms are deficient. The aim of this study was to carry out a psychometric analysis using the most commonly employed screening tool, the young Internet Addiction Test (IAT), comprising a sample of Lebanese University medical students. Two hundred and fifty-six undergraduate medical students from a university in Beirut, Lebanon were included in our IAT. Exploratory factor analysis was employed, and four factors were extracted. These four factors were named as Lack of Control, Social Withdrawal and Emotional Conflict, Time Management Problems, and Concealing Problematic Behavior. Furthermore, the selected factors explained 56.5% of the total variance. Cronbach's alpha coefficient for the internal reliability of the scale was found to be 0.91. For each subscale, the internal consistency score was approximated and detected as 0.76, 0.74, 0.69, and 0.63 for the first through fourth factor, respectively. Item total correlations were calculated and had a value range from 0.37 to 0.63 for the 20 items. IAT is a proper tool for evaluating internet addiction in Lebanese college students
Therapeutic potential of flavonoids in cancer: ROS-mediated mechanisms
Cancer is a leading cause of morbidity and mortality around the globe. Reactive oxygen species (ROS) play contradicting roles in cancer incidence and progression. Antioxidants have attracted attention as emerging therapeutic agents. Among these are flavonoids, which are natural polyphenols with established anticancer and antioxidant capacities. Increasing evidence shows that flavonoids can inhibit carcinogenesis via suppressing ROS levels. Surprisingly, flavonoids can also trigger excessive oxidative stress, but this can also induce death of malignant cells. In this review, we explore the inherent characteristics that contribute to the antioxidant capacity of flavonoids, and we dissect the scenarios in which they play the contrasting role as pro-oxidants. Furthermore, we elaborate on the pathways that link flavonoid-mediated modulation of ROS to the prevention and treatment of cancer. Special attention is given to the ROS-mediated anticancer functions that (-)-epigallocatechin gallate (EGCG), hesperetin, naringenin, quercetin, luteolin, and apigenin evoke in various cancers. We also delve into the structure-function relations that make flavonoids potent antioxidants. This review provides a detailed perspective that can be utilized in future experiments or trials that aim at utilizing flavonoids or verifying their efficacy for developing new pharmacologic agents. We support the argument that flavonoids are attractive candidates for cancer therapy
Une contribution à la gestion des applications SaaS mutualisées dans le cloud: approche par externalisation
The business model of cloud computing, especially in its application layer of services SaaS, has evolved into a new approach based on the exploitation of scale economies. This could be done by offering at the same time a unique application instance to several customers called tenants, following the multi-tenancy principle. The objective of this principle at the application level is to reduce the operating costs of the proposed service and to capitalize on the cumulative experience thought its sharing. However, the implementation of such principle requires addressing a number of challenges related to its organizational structure, in which each tenant must have the feeling of using a fully dedicated application for his usage. This implies a dynamic management of variability in tenants needs and a strict isolation of their data. In this dissertation, we focus on the principle of multi-tenancy and the main challenges arising before proposing our contributions. These can be summarized in three axes: (i) the first is the specification of a variability meta-model introducing new modeling concepts to better address the variability and outsource its management as a service. For this, we have introduced the concept of VaaS (Variability as a Service) as a new member of the Cloud services family. (ii) The second axis is to extend the management outsourcing policy, initially adopted to manage the variability, in order to apply it at the data level by providing a data isolation system as a service. The main advantage of such system is to isolate tenants’ data in an almost transparent way to developers, without introducing major changes to the architectures of existing applications. (iii) The last axis concerns the combination of the first two contributions and other related services to the administration and security of multi-tenant applications in a dedicated platform, towards a holistic approach of multi-tenancy management by outsourcing.Le modèle économique du Cloud Computing, plus précisément dans sa couche applicative de services SaaS, a évolué vers une nouvelle approche basée sur l’exploitation des économies d’échelle. Ceci a pu être réalisé en offrant en même temps une unique instance d’application à plusieurs clients dénommés locataires, suivant le principe de mutualisation. L’objectif principal de ce principe à un niveau applicatif est de réduire les coûts opérationnels du service proposé et de capitaliser sur l’expérience cumulée à travers son partage. Cependant, sa mise en œuvre nécessite de relever un certain nombre de défis liés à sa structure organisationnelle, au sein de laquelle chaque locataire doit avoir l’impression d’utiliser une application qui lui est pleinement dédiée. Cela implique une gestion dynamique de la variabilité des besoins de locataires et une isolation stricte de leurs données. Dans cette thèse, nous nous intéressons à ce principe de mutualisation et aux principaux défis qui en découlent avant de proposer nos contributions. Celles-ci se résument en trois axes : (i) le premier concerne la spécification d’un méta-modèle de variabilité introduisant de nouveaux concepts de modélisation pour mieux traiter la variabilité et externaliser sa gestion sous forme d’un service. Nous avons pour cela introduit la notion de VaaS (Variability as a Service) comme un nouveau membre de la famille des services du Cloud. (ii) Le second axe consiste à étendre la politique de gestion par externalisation, initialement adoptée pour gérer la variabilité, afin de l’appliquer au niveau des données en proposant un système d’isolation de données sous forme d’un service. Le principal avantage de ce système est d’isoler les données de locataires d’une manière quasi-transparente aux développeurs, sans introduire de changements majeurs sur les architectures des applications existantes. (iii) Le dernier axe concerne le regroupement des deux premières contributions ainsi que d’autres services liés à l’administration et à la sécurité des applications mutualisées dans une plateforme dédiée, vers une approche globale de gestion de ce type d’applications par externalisation
Guidage d'ondes de surface sur des métamatériaux textiles
The works shown in this thesis are devoted to the study of surface waves onto metamaterials produced in textiles by using a conductive yarn. The main objective of these studies is to promote technologies dedicated to surface waves guided onto textiles targeting wireless communications around the human body and operating at 2.45 GHz. The existence of a surface wave is more known in optics by the surface plasmon polariton which propagates naturally on the surface of a metal. It is characterized by an electromagnetic field trapped onto the surface and by a slow wave propagation compared to the propagation in free space. In order to benefit from the electromagnetic confinement property, metamaterials has opened the way for the surface wave development at lower frequency by means of periodic arrangement of metallic patterns. Studies carried out in this thesis are focused on the propagation of a surface wave guided by corrugated lines or meander-shaped lines without ground plane and by two-dimensional metasurfaces. Surface waves were excited in near field by means of dipole antennas. Some lines and metasurfaces were fabricated by Printed Circuit Board (PCB) technology and others on textiles by using conventional manufacturing techniques widely used in textile industry, namely embroidery and 3D spacer knitting. Performances in terms of transmission and dispersion curves of the electromagnetic wave propagating onto the textile structures are precisely analyzed in experiments and simulation. Then, they are compared with performances of the structures fabricated by PCB. The meander-shaped lines and metasurfaces manufactured by embroidery onto a cotton fabric showed good performances with an improvement of the transmission between the antennas compared to the transmission in free space. Performances of the meander-shaped line under curvatures were experimentally evaluated as well with the purpose of applications for body area communications. All the works shown in this thesis is based on simulation studies experimentally validated by determining first the dispersion curves and second the transmission properties.Les travaux présentés dans cette thèse sont consacrés à l’étude du guidage d’ondes de surface sur des métamatériaux fabriqués sur textile à base de fils conducteurs. Ces études ont pour objectif principal de contribuer au développement des technologies dédiées aux ondes de surface sur des textiles pour les applications de communication autour du corps humain fonctionnant à 2.45 GHz. L’existence de l’onde de surface est connue davantage dans le domaine de l’optique par le plasmon polariton de surface qui se propage naturellement sur la surface du métal. L’onde de surface est caractérisée par un champ électromagnétique confiné à la surface du métal et par une vitesse de propagation lente par rapport à la vitesse de propagation en espace libre. Afin de bénéficier de ces propriétés, le domaine des métamatériaux permet d’étendre ce concept vers les basses fréquences grâce à un arrangement périodique de motifs métalliques. Les études présentées dans cette thèse se focalisent sur la propagation d’une onde de surface sur des lignes corruguées ou à méandre sans plan de masse, et sur des métasurfaces à deux dimensions. Les ondes de surface ont été excitées en champ proche par des antennes dipôles. Des lignes et métasurfaces ont été fabriquées en technologie de circuit imprimé PCB, et d’autres sur des textiles à l’aide de techniques de fabrications conventionnelles largement utilisées dans le domaine textile à savoir la broderie et le tricot 3D dit spacer. Les performances en termes de transmission et de diagramme de dispersion de l’onde électromagnétique sur les différentes structures textiles sont analysées en détails expérimentalement et en simulation. Elles sont aussi comparées aux performances des structures sur PCB. Les lignes en méandre et les métasurfaces brodées sur un textile en coton ont révélé de bonnes performances avec une amélioration de la transmission entre les antennes comparativement à la transmission en espace libre. Les performances de transmission d’une ligne en méandre sous courbures ont aussi été évaluées expérimentalement dans l’objectif des communications autour du corps humain. L’ensemble des travaux présentés est basé sur des études de simulation vérifiées expérimentalement en déterminant d’une part les courbes de dispersion et d’autre part les propriétés de transmission
Surface waveguides on textile metamaterials
Les travaux présentés dans cette thèse sont consacrés à l’étude du guidage d’ondes de surface sur des métamatériaux fabriqués sur textile à base de fils conducteurs. Ces études ont pour objectif principal de contribuer au développement des technologies dédiées aux ondes de surface sur des textiles pour les applications de communication autour du corps humain fonctionnant à 2.45 GHz. L’existence de l’onde de surface est connue davantage dans le domaine de l’optique par le plasmon polariton de surface qui se propage naturellement sur la surface du métal. L’onde de surface est caractérisée par un champ électromagnétique confiné à la surface du métal et par une vitesse de propagation lente par rapport à la vitesse de propagation en espace libre. Afin de bénéficier de ces propriétés, le domaine des métamatériaux permet d’étendre ce concept vers les basses fréquences grâce à un arrangement périodique de motifs métalliques. Les études présentées dans cette thèse se focalisent sur la propagation d’une onde de surface sur des lignes corruguées ou à méandre sans plan de masse, et sur des métasurfaces à deux dimensions. Les ondes de surface ont été excitées en champ proche par des antennes dipôles. Des lignes et métasurfaces ont été fabriquées en technologie de circuit imprimé PCB, et d’autres sur des textiles à l’aide de techniques de fabrications conventionnelles largement utilisées dans le domaine textile à savoir la broderie et le tricot 3D dit spacer. Les performances en termes de transmission et de diagramme de dispersion de l’onde électromagnétique sur les différentes structures textiles sont analysées en détails expérimentalement et en simulation. Elles sont aussi comparées aux performances des structures sur PCB. Les lignes en méandre et les métasurfaces brodées sur un textile en coton ont révélé de bonnes performances avec une amélioration de la transmission entre les antennes comparativement à la transmission en espace libre. Les performances de transmission d’une ligne en méandre sous courbures ont aussi été évaluées expérimentalement dans l’objectif des communications autour du corps humain. L’ensemble des travaux présentés est basé sur des études de simulation vérifiées expérimentalement en déterminant d’une part les courbes de dispersion et d’autre part les propriétés de transmission.The works shown in this thesis are devoted to the study of surface waves onto metamaterials produced in textiles by using a conductive yarn. The main objective of these studies is to promote technologies dedicated to surface waves guided onto textiles targeting wireless communications around the human body and operating at 2.45 GHz. The existence of a surface wave is more known in optics by the surface plasmon polariton which propagates naturally on the surface of a metal. It is characterized by an electromagnetic field trapped onto the surface and by a slow wave propagation compared to the propagation in free space. In order to benefit from the electromagnetic confinement property, metamaterials has opened the way for the surface wave development at lower frequency by means of periodic arrangement of metallic patterns. Studies carried out in this thesis are focused on the propagation of a surface wave guided by corrugated lines or meander-shaped lines without ground plane and by two-dimensional metasurfaces. Surface waves were excited in near field by means of dipole antennas. Some lines and metasurfaces were fabricated by Printed Circuit Board (PCB) technology and others on textiles by using conventional manufacturing techniques widely used in textile industry, namely embroidery and 3D spacer knitting. Performances in terms of transmission and dispersion curves of the electromagnetic wave propagating onto the textile structures are precisely analyzed in experiments and simulation. Then, they are compared with performances of the structures fabricated by PCB. The meander-shaped lines and metasurfaces manufactured by embroidery onto a cotton fabric showed good performances with an improvement of the transmission between the antennas compared to the transmission in free space. Performances of the meander-shaped line under curvatures were experimentally evaluated as well with the purpose of applications for body area communications. All the works shown in this thesis is based on simulation studies experimentally validated by determining first the dispersion curves and second the transmission properties
Variability as a Service : Outsourcing Variability Management in Multi-tenant SaaS Applications
International audienceIn order to reduce the overall application expenses and time to market, SaaS (Software as a Service) providers tend to outsource several parts of their IT resources to other services providers. Such outsourcing helps SaaS providers in reducing costs and concentrating on their core competences: software domain expertises, business-processes modeling, implementation technologies and frameworks etc. However, when a SaaS provider offers a single application instance for multiple customers following the multi-tenant model, these customers (or tenants) requirements may differ, generating an important variability management concern. We believe that variability management should also be outsourced and considered as a service. The novelty of our work is to introduce the new concept of Variability as a Service (VaaS) model. It induces the appearance of VaaS providers. The objective is to relieve the SaaS providers looking forward to adopt such attractive multi-tenant solution, from developing a completely new and expensive variability solution beforehand. We present in this paper the first stage of our work: the VaaS meta-model and the VariaS component