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Search Results: 1 - 10 of 223296 matches for " Jean Stéphane N’dri "
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Studies of the Chemical Reactivity of a Series of Rhodanine Derivatives by Approaches to Quantum Chemistry  [PDF]
Wacothon Karime Coulibaly, Jean Stéphane Ndri, Mamadou Guy-Richard Koné, Camille Déliko Dago, Christelle N’ta Ambeu, Jean-Pierre Bazureau, Nahossé Ziao
Computational Molecular Bioscience (CMB) , 2019, DOI: 10.4236/cmb.2019.93005
Abstract: This theoretical chemical reactivity study was conducted using the Density Functional Theory (DFT) method, at computational level B3LYP/6-31G (d). It involved a series of six (06) 5-arylidene rhodanines and allowed to predict the chemical reactivity of these compounds. DFT global chemical reactivity descriptors (HOMO and LUMO energies, chemical hardness, softness, electronegativity) were examined to predict the relative stability and reactivity of rhodanin derivatives. Thus, the compound 6 which has an energy gap between the orbitals of ΔEgap = 3.004 eV is the most polarizable, the most reactive, the least stable, the best electron donor and the softest molecule. Calculation of the local indices of reactivity as well as dual descriptors revealed that the sulfur heteroatom of the Rhodanine ring is the privileged site of electrophilic attack in a state of sp3 hybridization and privileged site of nucleophilic attack in a state of sp2 hybridization.
Le paysage télévisuel espagnol actuel : un chaos régénérateur ?
Jean-Stéphane Durán?Froix
Cahiers de Civilisation Espagnole Contemporaine , 2011, DOI: 10.4000/ccec.2539
Abstract: El sistema televisivo espa ol es uno de las más complejos de Europa. Su estructura comprende cuatro niveles diferentes, correspondientes a los tipos de público y de mercado a los que ha dado lugar el desmantelamiento del aparato audiovisual y la cultura de masas del franquismo. Cada uno de estos estratos está formado a su vez por un sector público y por un sector privado, cuya importancia respectiva varia en función del tama o de la audiencia que ambos se disputan. El caos mediático resultante obedece también al dinamismo de la más potente industria cultural del país. A pesar de ello, la televisión espa ola da muestras de declive y con ella una de las cultura de masas más influyente y desconocida.
Les professeurs d’université et la transition espagnole
Jean-Stéphane Durán?Froix
Cahiers de Civilisation Espagnole Contemporaine , 2011, DOI: 10.4000/ccec.195
Abstract: Souvent décriés, plus rarement célébrés, les professeurs d’Université furent pourtant l’un des principaux acteurs de la transition politique espagnole. Présents, en cette fin de franquisme, au gouvernement, aux Cortes et au Conseil du Royaume, ils constituaient, comme au temps de la Seconde République, la catégorie socio-professionnelle la mieux représentée au sein de l’élite dirigeante. Celle-là même qui démantela, sans trop d’hésitation et moins encore d’effusion de sang, la plus vieille de...
A Kinematics Scalar Projection Method (KSP) for Incompressible Flows with Variable Density  [PDF]
Jean-Paul Caltagirone, Stéphane Vincent
Open Journal of Fluid Dynamics (OJFD) , 2015, DOI: 10.4236/ojfd.2015.52019
Abstract: A new scalar projection method presented for simulating incompressible flows with variable density is proposed. It reverses conventional projection algorithm by computing first the irrotational component of the velocity and then the pressure. The first phase of the projection is purely kinematics. The predicted velocity field is subjected to a discrete Hodge-Helmholtz decomposition. The second phase of upgrade of pressure from the density uses Stokes’ theorem to explicitly compute the pressure. If all or part of the boundary conditions is then fixed on the divergence free physical field, the system required to be solved for the scalar potential of velocity becomes a Poisson equation with constant coefficients fitted with Dirichlet conditions.
Triangular test applied to the clinical trial of azithromycin against relapses in Plasmodium vivax infections
Stéphane Ranque, Sékéné Badiaga, Jean Delmont, Philippe Brouqui
Malaria Journal , 2002, DOI: 10.1186/1475-2875-1-13
Abstract: To test whether the P. vivax relapse rate was either <12% or ≥ 45% in patients treated with azithromycin, a sequential analysis based on the TT was as used. Patients infected with P. vivax were treated with azithromycin, 1.2 g daily, for 7 days. The onset of a relapse infection was monitored.Five patients presenting with an acute P. vivax infection were included in the study. All the patients were initially cured. Three patients reported mild gastrointestinal adverse effects. When the third patient relapsed, the sample path crossed the upper boundary of the TT, and the trial was stopped.Using the triangular test, with only a small number of patients, we concluded that azithromycin was not effective enough in preventing P. vivax relapses to warrant further evaluation in phase III. It is suggested that a wider use of sequential analysis in phase II anti-infective drugs trials may have financial and ethical benefits.The purpose of phase II trials is to determine whether a drug is effective enough to warrant further evaluation in phase III. For ethical reasons, the smallest number of patients necessary to reach a firm conclusion should be included in a phase II trial. To this end, it is critical to choose decision methods that allows early cessation when effectiveness or ineffectiveness is clear. Sequential methods, such as the triangular test (TT), have the required properties, but although they have been described for many years, few clinical trials have yet made use of them. This paper presents a concrete example of a non-comparative phase II trial design and analysis based on the TT. In section 1, the rationale for using the TT in a phase II trial is examined. In section 2, an application of the TT to study the anti-relapse activity of azithromycin on Plasmodium vivax is described. Finally, in section 3, the impact of using the TT on the design of the present trial is outlined.The standard approach in clinical trials is the fixed-sample analysis. It assumes a single
Modeling the Dynamics of Malaria Transmission with Bed Net Protection Perspective  [PDF]
Jean Claude Kamgang, Vivient Corneille Kamla, Stéphane Yanick Tchoumi
Applied Mathematics (AM) , 2014, DOI: 10.4236/am.2014.519298
Abstract: We propose and analyze an epidemiological model to evaluate the effectiveness of bed nets as a prophylactic measure in malaria-endemic areas. The main purpose in this work is the modeling of the aggressiveness of anopheles mosquitoes relative to the way humans use to protect themselves against bites of mosquitoes. This model is a system of several differential equations: the number of equations depends on the particular assumptions of the model. We compute the basic reproduction number\"\", and show that if\"\", the disease free equilibrium (DFE) is globally asymptotically stable on the non-negative orthant. If\"\", the system admits a unique endemic equilibrium (EE) that is globally and asymptotically stable. Numerical simulations are presented corresponding to scenarios typical of malaria-endemic areas, based on data collected in the literature. Finally, we discuss the relative effectiveness of different kinds of bed nets.
Interactive Multivariate Data Analysis in R with the ade4 and ade4TkGUI Packages
Jean Thioulouse,Stéphane Dray
Journal of Statistical Software , 2007,
Abstract: ade4 is a multivariate data analysis package for the R statistical environment, and ade4TkGUI is a Tcl/Tk graphical user interface for the most essential methods of ade4. Both packages are available on CRAN. An overview of ade4TkGUI is presented, and the pros and cons of this approach are discussed. We conclude that command line interfaces (CLI) and graphical user interfaces (GUI) are complementary. ade4TkGUI can be valuable for biologists and particularly for ecologists who are often occasional users of R. It can spare them having to acquire an in-depth knowledge of R, and it can help first time users in a first approach.
Predictive Factors for Viral B and C Infection in Health Workers in a University Hospital in Ivory Cost  [PDF]
Okon Anassi Jean-Baptiste, Koné Amadou, Diakité Mamadou, Aké Fabrice, Thot’o Amani Sroboua, Ndri N’guessan
Open Journal of Gastroenterology (OJGas) , 2018, DOI: 10.4236/ojgas.2018.810039
Abstract: Purpose: To evaluate the serological status of hepatitis B and C and to identify the risk factors for viral B and C infection in health workers at the university hospital. Material and Method: Mono-centric cross-sectional study carried out at Bouaké University Hospital from March 2nd to May 16th, 2016, concerning the health staff of the Bouaké University Hospital. Cross-sectional study mono-centric concerning the serological status of viral hepatitis B and C from the period from March 2nd to May 16th, 2016 of the health staff of the University Hospital of Bouaké. It has benefited from data from PNLHVi (national program against viral hepatitis) as part of its awareness campaign. The data were analyzed by SPSS software version 20.0. Results: Of the 1107 health workers, 632 had been included, representing a participation rate of 57.1%. The average age of the staff was 37.8 years with extremes ranging from 18 to 66 years. The sex ratio (H/F) was 0.8. Accidents with blood exposure were noted in 52.4% of cases. The maximum vaccine coverage was 16.1%. The prevalence of HBsAg was 8.4%. Contact with HBV was present in 3/4 of the staff. Anti HCV Ab was positive in 1.4% of the staff. Males, age over 50 and over 20 years of seniority were associated with HBV. Also, HBV infection was significantly higher in boys and girls (81.7%), nurses (78.3%) and nursing aides (73.8%), (p = 0.022). HCV infection was significantly correlated with emergency services. Conclusion: Age, gender, seniority, paramedic qualification, and high risk of exposure to body fluids were correlated with viral B infection while emergency department membership was a factor risk of HCV infection.
Mitochondrial DNA Mutations Provoke Dominant Inhibition of Mitochondrial Inner Membrane Fusion
Cécile Sauvanet, Stéphane Duvezin-Caubet,nédicte Salin, Claudine David, Aurélie Massoni-Laporte, Jean-Paul di Rago, Manuel Rojo
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0049639
Abstract: Mitochondria are highly dynamic organelles that continuously move, fuse and divide. Mitochondrial dynamics modulate overall mitochondrial morphology and are essential for the proper function, maintenance and transmission of mitochondria and mitochondrial DNA (mtDNA). We have investigated mitochondrial fusion in yeast cells with severe defects in oxidative phosphorylation (OXPHOS) due to removal or various specific mutations of mtDNA. We find that, under fermentative conditions, OXPHOS deficient cells maintain normal levels of cellular ATP and ADP but display a reduced mitochondrial inner membrane potential. We demonstrate that, despite metabolic compensation by glycolysis, OXPHOS defects are associated to a selective inhibition of inner but not outer membrane fusion. Fusion inhibition was dominant and hampered the fusion of mutant mitochondria with wild-type mitochondria. Inhibition of inner membrane fusion was not systematically associated to changes of mitochondrial distribution and morphology, nor to changes in the isoform pattern of Mgm1, the major fusion factor of the inner membrane. However, inhibition of inner membrane fusion correlated with specific alterations of mitochondrial ultrastructure, notably with the presence of aligned and unfused inner membranes that are connected to two mitochondrial boundaries. The fusion inhibition observed upon deletion of OXPHOS related genes or upon removal of the entire mtDNA was similar to that observed upon introduction of point mutations in the mitochondrial ATP6 gene that are associated to neurogenic ataxia and retinitis pigmentosa (NARP) or to maternally inherited Leigh Syndrome (MILS) in humans. Our findings indicate that the consequences of mtDNA mutations may not be limited to OXPHOS defects but may also include alterations in mitochondrial fusion. Our results further imply that, in healthy cells, the dominant inhibition of fusion could mediate the exclusion of OXPHOS-deficient mitochondria from the network of functional, fusogenic mitochondria.
Sparse representations and convex optimization as tools for LOFAR radio interferometric imaging
Julien N. Girard,Hugh Garsden,Jean Luc Starck,Stéphane Corbel,Arnaud Woiselle,Cyril Tasse,John P. McKean,Jér?me Bobin
Physics , 2015, DOI: 10.1088/1748-0221/10/08/C08013
Abstract: Compressed sensing theory is slowly making its way to solve more and more astronomical inverse problems. We address here the application of sparse representations, convex optimization and proximal theory to radio interferometric imaging. First, we expose the theory behind interferometric imaging, sparse representations and convex optimization, and second, we illustrate their application with numerical tests with SASIR, an implementation of the FISTA, a Forward-Backward splitting algorithm hosted in a LOFAR imager. Various tests have been conducted in Garsden et al., 2015. The main results are: i) an improved angular resolution (super resolution of a factor ~2) with point sources as compared to CLEAN on the same data, ii) correct photometry measurements on a field of point sources at high dynamic range and iii) the imaging of extended sources with improved fidelity. SASIR provides better reconstructions (five time less residuals) of the extended emission as compared to CLEAN. With the advent of large radiotelescopes, there is scope for improving classical imaging methods with convex optimization methods combined with sparse representations.
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