14 results on '"Merabet O"'
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2. Hysteretic beam model for the seismic analysis of RC structures
- Author
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Miramontes, D., primary, Merabet, O., additional, and Reynouard, J. M., additional
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- 2022
- Full Text
- View/download PDF
3. Steel-concrete bond model: Finite element analysis of a beam-column joint subjected to cyclic alternate loading
- Author
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Fleury, F., primary, Merabet, O., additional, and Reynouard, J.-M., additional
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- 2022
- Full Text
- View/download PDF
4. MULTICOMPONENT MODEL OF REINFORCED CONCRETE JOINTS FOR CYCLIC LOADING
- Author
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Fleury, F., Reynouard, J.-M., and Merabet, O.
- Subjects
Concrete construction -- Joints ,Reinforced concrete -- Models ,Girders -- Design and construction ,Columns -- Design and construction ,Load factor design -- Evaluation ,Science and technology - Abstract
Efficient simplified models are available for reinforced concrete beams and columns, with the assumption of a perfectly rigid connection. However, interior beam/column joints have been shown to be the area of strong deformation and degradation mechanisms, involving mainly the cyclic behaviors of concrete under shear and of bond under push-pull loading. In this paper, a global component-based model is proposed for the beam/column connections of reinforced concrete frame structures that can be directly connected to beam elements. This model incorporates explicitly the modeling of concrete, steel, and steel/concrete bond. Thus, the key mechanisms of deformation and degradation of the connection, as well as various interactions can be taken into account naturally. In particular, the effect of push-pull-type loading on the flexural steels can be captured. On the basis of a local finite-element modeling of the connection, simplifying assumptions are proposed and implemented leading to the component-based model. Both approaches (local and component-based) are compared on an application example.
- Published
- 2000
5. Steel-concrete interfaces: Damage and plasticity computations
- Author
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Reynouard, J.M., primary, Merabet, O., additional, and Clément, J.L., additional
- Published
- 1995
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6. An Accelerated Aquila Optimizer for Maximum Power Point Tracking of PV Systems under Partial Shading Conditions
- Author
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Belmadani Hamza, Merabet Oussama, Khettab Sofiane, Maindola Meenakshi, Bajaj Mohit, and Oubelaid Adel
- Subjects
Environmental sciences ,GE1-350 - Abstract
In this work, an improved version of the recent Aquila Optimizer was designed for Maximum Power Point Tracking. The new algorithm was tested on a standalone PV system under several complex partial shading scenarios. A comparative study was conducted to evaluate efficiency, robustness, and convergence speed against the PSO, and the standard AO algorithms. The results indicate that the proposed Accelerated Aquila Optimizer (AAO) generally outperformed its competitors, particularly in terms of convergence time.
- Published
- 2024
- Full Text
- View/download PDF
7. Finite element implementation of a steel-concrete bond law for nonlinear analysis of beam-column joints subjected to earthquake type loading
- Author
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Fleury, F., primary, Reynouard, J.M., additional, and Merabet, O., additional
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- 1999
- Full Text
- View/download PDF
8. BEAM GLOBAL MODEL FOR THE SEISMIC ANALYSIS OF RC FRAMES
- Author
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MIRAMONTES, D., primary, MERABET, O., additional, and REYNOUARD, J. M., additional
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- 1996
- Full Text
- View/download PDF
9. Infection of Human Endothelial Cells with Lassa Virus Induces Early but Transient Activation and Low Type I IFN Response Compared to the Closely-Related Nonpathogenic Mopeia Virus.
- Author
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Merabet O, Pietrosemoli N, Perthame E, Armengaud J, Gaillard JC, Borges-Cardoso V, Daniau M, Legras-Lachuer C, Carnec X, and Baize S
- Subjects
- Animals, Endothelial Cells, Humans, Lassa virus, Proteomics, Arenaviridae genetics, Arenavirus, Lassa Fever
- Abstract
Lassa virus (LASV), an Old World arenavirus, is responsible for hemorrhagic fevers in western Africa. The privileged tropism of LASV for endothelial cells combined with a dysregulated inflammatory response are the main cause of the increase in vascular permeability observed during the disease. Mopeia virus (MOPV) is another arenavirus closely related to LASV but nonpathogenic for non-human primates (NHPs) and has never been described in humans. MOPV is more immunogenic than LASV in NHPs and in vitro in human immune cell models, with more intense type I IFN and adaptive cellular responses. Here, we compared the transcriptomic and proteomic responses of human umbilical vein endothelial cells (HUVECs) to infection with the two viruses to further decipher the mechanisms involved in their differences in immunogenicity and pathogenicity. Both viruses replicated durably and efficiently in HUVECs, but the responses they induced were strikingly different. Modest activation was observed at an early stage of LASV infection and then rapidly shut down. By contrast, MOPV induced a late but more intense response, characterized by the expression of genes and proteins mainly associated with the type I IFN response and antigen processing/presentation. Such a response is consistent with the higher immunogenicity of MOPV relative to LASV, whereas the lack of an innate response induced in HUVECs by LASV is consistent with its uncontrolled systemic dissemination through the vascular endothelium.
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- 2022
- Full Text
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10. A single-shot Lassa vaccine induces long-term immunity and protects cynomolgus monkeys against heterologous strains.
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Mateo M, Reynard S, Journeaux A, Germain C, Hortion J, Carnec X, Picard C, Baillet N, Borges-Cardoso V, Merabet O, Vallve A, Barron S, Jourjon O, Lacroix O, Duthey A, Dirheimer M, Jouvion G, Moreau PH, Fellmann L, Carbonnelle C, Raoul H, Tangy F, and Baize S
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- Africa, Western, Animals, Lassa virus, Macaca fascicularis, Nucleoproteins, Lassa Fever prevention & control, Viral Vaccines immunology
- Abstract
A safe and protective Lassa virus vaccine is crucially needed in Western Africa to stem the recurrent outbreaks of Lassa virus infections in Nigeria and the emergence of Lassa virus in previously unaffected countries, such as Benin and Togo. Major challenges in developing a Lassa virus vaccine include the high diversity of circulating strains and their reemergence from 1 year to another. To address each of these challenges, we immunized cynomolgus monkeys with a measles virus vector expressing the Lassa virus glycoprotein and nucleoprotein of the prototypic Lassa virus strain Josiah (MeV-NP). To evaluate vaccine efficacy against heterologous strains of Lassa virus, we challenged the monkeys a month later with heterologous strains from lineage II or lineage VII, finding that the vaccine was protective against these strains. A second cohort of monkeys was challenged 1 year later with the homologous Josiah strain, finding that a single dose of MeV-NP was sufficient to protect all vaccinated monkeys. These studies demonstrate that MeV-NP can generate both long-lasting immune responses and responses that are able to protect against diverse strains of Lassa virus., (Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)
- Published
- 2021
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11. E3 Ligase ITCH Interacts with the Z Matrix Protein of Lassa and Mopeia Viruses and Is Required for the Release of Infectious Particles.
- Author
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Baillet N, Krieger S, Carnec X, Mateo M, Journeaux A, Merabet O, Caro V, Tangy F, Vidalain PO, and Baize S
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- Animals, Arenaviridae genetics, Chlorocebus aethiops, HEK293 Cells, HeLa Cells, Humans, Lassa virus genetics, Repressor Proteins genetics, Two-Hybrid System Techniques, Ubiquitin-Protein Ligases genetics, Vero Cells, Viral Proteins genetics, Arenaviridae physiology, Host Microbial Interactions, Lassa virus physiology, Repressor Proteins metabolism, Ubiquitin-Protein Ligases metabolism, Viral Proteins metabolism, Virus Assembly
- Abstract
Lassa virus (LASV) and Mopeia virus (MOPV) are two closely related, rodent-born mammarenaviruses. LASV is the causative agent of Lassa fever, a deadly hemorrhagic fever endemic in West Africa, whereas MOPV is non-pathogenic in humans. The Z matrix protein of arenaviruses is essential to virus assembly and budding by recruiting host factors, a mechanism that remains partially defined. To better characterize the interactions involved, a yeast two-hybrid screen was conducted using the Z proteins from LASV and MOPV as a bait. The cellular proteins ITCH and WWP1, two members of the Nedd4 family of HECT E3 ubiquitin ligases, were found to bind the Z proteins of LASV, MOPV and other arenaviruses. The PPxY late-domain motif of the Z proteins is required for the interaction with ITCH, although the E3 ubiquitin-ligase activity of ITCH is not involved in Z ubiquitination. The silencing of ITCH was shown to affect the replication of the old-world mammarenaviruses LASV, MOPV, Lymphocytic choriomeningitis virus (LCMV) and to a lesser extent Lujo virus (LUJV). More precisely, ITCH was involved in the egress of virus-like particles and the release of infectious progeny viruses. Thus, ITCH constitutes a novel interactor of LASV and MOPV Z proteins that is involved in virus assembly and release., Competing Interests: The authors declare no conflicts of interest. The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
- Published
- 2019
- Full Text
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12. [Health and drug consumption profile in Cameroon].
- Author
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Commeyras C, Ndo JR, Merabet O, Kone H, and Rakotondrabe FP
- Subjects
- Adolescent, Adult, Aged, Cameroon epidemiology, Child, Child, Preschool, Cross-Sectional Studies, Drug Costs statistics & numerical data, Drug Prescriptions economics, Female, Health Care Surveys, Health Priorities organization & administration, Health Surveys, Hospital Costs statistics & numerical data, Hospitalization economics, Humans, Infant, Male, Middle Aged, Morbidity, Nonprescription Drugs economics, Nonprescription Drugs therapeutic use, Referral and Consultation economics, Socioeconomic Factors, Transportation economics, Drug Utilization statistics & numerical data, Health Care Costs statistics & numerical data, Health Services statistics & numerical data, Health Services Accessibility statistics & numerical data
- Abstract
To begin a renewal of national health policy in Cameroon, a steering committee from the Cameroon Ministry of Health and its partners sought to analyze health demand through a national population survey and supply capacity through a national survey of retail drug stores. A survey of healthcare consumers was also conducted. The present publication describes the results of the consumer survey. Their socioeconomic profile of these consumers was much higher than that of the general population. This indicates that the poorest do not use health facilities or even self-medication. Within the population of healthcare consumers, women and children used private for-profit (60 %) and nonprofit (65 %) private health facilities most often, while men used mainly private pharmacies (60 %) and street drug (medication) sellers (62 %). In all, 85 % of the users of formal drug retailers had had a consultation with a healthcare provider. The average consultation cost was 1,440 CFA Francs, but the 7 % who paid the provider directly had an average cost of 1,794 CFA Francs. In all, 22 % did not pay at all, because of free consultations in some health facilities (40 %), personal relationships with prescribers, or other reasons. Hospitalization costs averaged 4,800 CFA Francs, and medical examinations 4,534 CFA Francs. These two categories had the highest percentage of insured patients (12 % and 5 %). Drug costs were 5,067 CFA Francs from pharmacies and 1,308 CFA Francs in the street. Total healthcare costs per person averaged 14,990 CFA Francs. Weighted, drugs accounted for the largest share, followed by hospitalisation, medical examinations, consultations, and transportation. In the formal sector, less than 10 % reported paying fees directly to the healthcare providers rather than to the HF cashier. Except for consultation in the public sector, paying providers was associated with a lower bill. However, 24 % purchased drugs from the healthcare workers, which indicates that drug sales are an important "sideline" in the formal sector. The average number of drugs per prescription was 4.1, and 24 % contained more than 6 drugs. The leading 50 drugs prescribed accounted for 57 % of the total and so did the top 50 purchased. The leading 40 prescribed, however, were mainly generics, while the top 40 purchased included many more brand-name drugs. Moreover, injectable drugs accounted for 40 % of the 40 most prescribed drugs, 50 % of the 40 most purchased, and 45 % of the 40 most purchased prescribed drugs. These figures show the low quality of prescription and dispensing.
- Published
- 2006
13. [Household behaviour regarding health and drug consumption in Cameroon].
- Author
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Commeyras C, Ndo JR, Merabet O, Kone H, and Rakotondrabe FP
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- Adult, Cameroon epidemiology, Cost of Illness, Female, Health Care Costs statistics & numerical data, Health Care Surveys, Health Status, Health Surveys, Humans, Male, Medicine, African Traditional, Middle Aged, Morbidity, Needs Assessment, Patient Acceptance of Health Care statistics & numerical data, Residence Characteristics statistics & numerical data, Self Care economics, Self Care methods, Self Care psychology, Socioeconomic Factors, Drug Utilization statistics & numerical data, Family Characteristics ethnology, Health Behavior ethnology, Health Services statistics & numerical data, Patient Acceptance of Health Care ethnology
- Abstract
To begin a renewal of national health policy in Cameroon, a steering committee from the Cameroon Ministry of Health and its partners sought to analyze health demand through a national population survey and supply capacity through a national survey of retail drug stores. A survey of healthcare consumers was also conducted. The present publication describes the results of the population survey. It measured perceived, rather than objective (diagnosed), morbidity. The morbidity ratio, defined as the proportion of persons who reported having been ill during the reference period, two weeks before the survey, was measured at 23% and varied with demographic, social, and economic characteristics such as age, sex, poverty, the sex and educational level of the head of the household, and place of residence (urban or rural). We asked about six types of response to illness: modern consultation, traditional consultation, modern self-medication, traditional self-medication, expectant management, and prayer. The approaches of individual therapeutic itineraries fluctuated for each subject, depending first on financial capacity, second on geographic accessibility, and third on socio-cultural perception of the illness, which governed in particular choice of a modern or traditional approach. Thus, less than a quarter of all subjects initially chose consultation in a health care centre, which accounted for only 31% of all approaches, and 37% of the effective health responses (excluding treatment abstention). Half, however, chose it as a second step, and 40% as a third. Globally, 56% of those who reported illness did not seek a modern consultation during this illness, and 23% of those who took three separate steps for the same illness never sought a modern consultation. Half of all household health expenditures were for medication, and this proportion was highest in the poorest population. In 2002, the population spent 366 billion CFA Francs on health care: 170 billion for drugs, 75 billion for medical examinations, 53 billion for hospitalization, 30 billion for consultations; and 22 billion for transportation.
- Published
- 2006
14. [Study of access to health care and drugs in Cameroon: 1. Methods and validation].
- Author
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Commeyras C, Ndo JR, Merabet O, Koné H, and Rakotondrabé FP
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- Adolescent, Adult, Aged, Aged, 80 and over, Cameroon epidemiology, Child, Child, Preschool, Family Characteristics, Fees, Pharmaceutical statistics & numerical data, Female, Health Expenditures statistics & numerical data, Health Services statistics & numerical data, Health Services supply & distribution, Humans, Male, Middle Aged, Needs Assessment statistics & numerical data, Pharmacies statistics & numerical data, Retrospective Studies, Rural Health statistics & numerical data, Socioeconomic Factors, Urban Health statistics & numerical data, Health Services Accessibility statistics & numerical data, Health Services Needs and Demand statistics & numerical data, Pharmaceutical Preparations supply & distribution
- Abstract
During the 1980s, an economic depression and the concomitant decrease in the national health budget modified the population's health behavior. Improvement of the economy since the late 1990s makes it possible to renew the national health policy. To prepare the highly indebted and poor countries' program (HIPC), the Minister of Health and its partners commissioned a survey to measure the population's real access to health care and the factors that determine this accessibility and to propose concrete corrective actions. To fulfill these objectives, the steering committee decided to analyze health care demand, through a national population survey, and supply capacity, through a national survey of pharmacies and other drug dispensers. A survey of persons using medications will also be conducted (Fig.1). Focusing on this component of health care is justified by these findings: 95% of persons feeling ill buy drugs, whereas only 31% consult a physician or other healthcare provider, and half of the average household's health expenditures are for drugs. Financial, geographic, social and quality indicators were defined to measure accessibility and its determining factors (Table 1). The smallest administrative unit, the health area (HA), was chosen as the sampling unit, to enable us to survey together healthcare demand, supply and consumption according to different concentrations of supply and demand . It behaves as a cluster of sampling units of different populations: drug retailers of all sectors, drug users, households, and ill persons within the households. The HA samples include Yaounde and Douala, with urban and rural sub-samples, for which sampling ratios increase with the diversity of supply and demand, according to several pre-defined factors. The study includes 400 HAs, covering more than one third of the population (Table 2). Within these HAs, 900 pharmacies and other formal drug retailers, 709 street vendors, 4,505 households, 2,532 ill persons in these households, 4,121 pharmacy customers and 850 customers of street vendors were surveyed, i.e., more than 13,600 questionnaires. Assessment of data quality shows that the sample is representative of the national population for its socioeconomic characteristics. Its geographic distribution, even after correction, nonetheless favors urban areas, where both supply and demand are high. Generalizing the 3 sub-samples to the national level thus requires caution, especially for the geographic distribution. Other limitations and possible biases are described and evaluated. However, the retrospective demographic and statistic evaluation shows that the samples are representative of their population and that the data quality can be considered good. This article describes the background of this study and justifies its methodological choices. Future publications will analyze the data collected.
- Published
- 2005
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