321 research outputs found
Solutions de viscosite des equations de Hamilton-Jacobi en dimension infinie. Cas stationnaire
We show the uniqueness and the existence of viscosity solutions of Hamilton-Jacobi equations on a smooth Banach spaces. The tool used is the variational principle of Deville, Godefroy and Zizler. The existence is given by Perron's method. So we give a comparaison assertion for semicontinuous solutions
Le Sahara marocain : désenclavement et développement durable
The Moroccan Sahara: opening-up and sustainable development. The
enclosing of the Moroccan Sahara results from the inversion and old situation.
Indeed, during a very long time, the area was a way of passage, a platform in the
south of Morocco. In testify the Tran-Saharan commercial routes, which were the
main transportation routes back in time, like the goal of integration of the area in
the country and compared to western Africa. It is with the economic crisis, and
even a political crisis causing a fold on itself of this area until 1975.Since Sahara
belongs to Morocco, it still profits a considerable public effort to carry out its
opening-up and its economic insertion within the country. Massive investments
carried out by the State give to the area the structuring which it missed. Which
are the aspects of the Sahara development? Which role played the State in this
development? The intervention of the State contributes to bring effective
solutions to the problem of the opening-up of this surrounding space
Semiautomated High-Performance Liquid Chromatographic Method for the Determination of Benzodiazepines in Whole Blood
A semiautomated method for the determination of five frequently prescribed benzodiazepines (BZD) (clonazepam, diazepam, flunitrazepam, midazolam, and oxazepam) in whole blood samples by reversed-phase high-performance liquid chromatography following simple online enrichment and clean-up on a short precolumn is described. After precipitation of protein and red cells with a mixture of organic solvents (methanol/acetonitrile, 50:50), the aliquot is centrifuged and the organic upper phase evaporated under a gentle stream of nitrogen. The residue is reconstituted by adding 500 pL of a mixture of phosphate buffer (20mM, pH 2.2) and acetonitrile (70:30, v/v). The sample is then directly introduced into the column-switching column. The precolumn is first washed with phosphate buffer at pH 7.2. Compounds retained on the precolumn are then eluted in the back-flush mode and separated on a C8 semi-microcolumn (Lichrospher select B, 125 × 3 mm). The BZD studied are determined by a diode-array detector at 254 nm. The method shows excellent linearity between 25 and 1000 ng/mL for clonazepam, flunitrazepam, and midazolam and between 25 and 5000 ng/mt for diazepam and oxazepam. The recoveries are around 80% for clonazepam and oxazepam and around 90% for the three others. Coefficients of variation for between-day and within-day assays are < 15% for low concentrations close to the limit of quantitation and < 5% for high concentration
An approximate dynamic programming approach to the admission control of elective patients
In this paper, we propose an approximate dynamic programming (ADP) algorithm
to solve a Markov decision process (MDP) formulation for the admission control
of elective patients. To manage the elective patients from multiple specialties
equitably and efficiently, we establish a waiting list and assign each patient
a time-dependent dynamic priority score. Then, taking the random arrivals of
patients into account, sequential decisions are made on a weekly basis. At the
end of each week, we select the patients to be treated in the following week
from the waiting list. By minimizing the cost function of the MDP over an
infinite horizon, we seek to achieve the best trade-off between the patients'
waiting times and the over-utilization of surgical resources. Considering the
curses of dimensionality resulting from the large scale of realistically sized
problems, we first analyze the structural properties of the MDP and propose an
algorithm that facilitates the search for best actions. We then develop a novel
reinforcement-learning-based ADP algorithm as the solution technique.
Experimental results reveal that the proposed algorithms consume much less
computation time in comparison with that required by conventional dynamic
programming methods. Additionally, the algorithms are shown to be capable of
computing high-quality near-optimal policies for realistically sized problems
Évaluation de la qualité des eaux souterraines pour l’utilisation dans l’eau potable et l’agriculture : plaine de Tadla, Maroc
La plaine de Tadla fait partie du bassin de l’oued Oum Erbia situé au centre du Maroc. Ses ressources en eau souterraine sont développées pour l’approvisionnement en eau potable, industrielle et agricole. Afind'évaluer la qualité des eaux souterraines dans la zone d’ d'étude, 25 échantillons d'eau souterraines ont été prélevés et différents paramètres ont été analysés sur le plan physico-chimique et bactériologique:température, conductivité électrique, pH, TDS, Na+, K+, Ca2+, Mg2+, Cl-, HCO-3, SO2-4, NO-3, NH+4, FeT, streptocoques fécaux, coliformes fécaux et coliformes totaux. L'indice chimique tel que le coefficient d’absorption du sodium (SAR) et l'indice de perméabilité (IP) ont également été déterminés. Les résultats obtenus montrent que les eaux souterraines du bassin sont généralement dure à très à dure. Les concentrations sont classées comme suit : Na+ > Ca2+ > Mg2+ > K+ et Cl- > HCO3- > SO42- > NO-3. Les faciès chimiques trouvés sont le bicarbonaté calcique et le Chloruré sodique avec une prédominance de ce dernier. La qualité des eaux souterraines est liée à la lithologie du secteur. Les valeurs de l'indice de saturation (calculés par le programme PHREEQC) montre que presque tous les échantillons d'eau sont saturés à sous-saturés en carbonate et sous saturés en sulfate. Le rapport d’adsorption du sodium (SAR)nous a permis de qualifier les eaux souterraines destinées à l’irrigation. L’analyse hydrochimique a montré la mauvaise qualité des eaux se traduisant par des valeurs importantes en chlorures, en nitrites et nitrates.Ainsi que la contamination de tous les puits par les germes de la contamination fécale. Il ressort de cette analyse que les eaux souterraines sont chimiquement non appropriées à la consommation humaine et auxusages agricoles.Mots-clés : plaine de Tadla, hydrochimie, qualité des eaux souterraines, hydrogéologie, type d’eau
Radon Concentration in Urban Areas in the North and West of Morocco
Radon is a colorless, odorless radioactive gas produced by the decay of uranium and radium. It is the second cause of cancer of the lungs after smoking. It has been present in Earth's crust since the creation of Earth. Uranium-rich rocks in the deep crust are the main source of radon. Its emanation from the ground surface varies from one point to another depending on the physical characteristics of the terrain crossed as observed in this study between North and West Morocco. A dosimetric study of those emanations was performed by using the LR-115 solid-state nuclear track detector (SSNTD) which was subsequently processed by techniques developed and calibrated in the laboratory. The study revealed high concentrations of this gas in confined spaces at ground level and, in particular, in basements and less-ventilated ground floor rooms. In order to reduce these concentrations of radon and the probability of carcinogenic attacks by these accumulations of this gas, it is recommended to ventilate these premises well. Good air circulation allows the removal of this harmful gas
Antibacterial Activity of Francoeuria crispa, Pulicaria undulata, Ziziphus spina-christi and Cucurbita pepo Against Seven Standard Pathogenic Bacteria
The antibacterial potentials of the medicinal plants Francoeuria crispa (Forssk.) Cass., Pulicaria undulata (L.) Kostel, Ziziphus spina-christi (L.) Desf. and Cucurbita pepo L. Ethanol, petroleum ether, ethyl Acetate, methanol and aqueous extracts, at a concentration of 100 mg/ml, were evaluated against selected bacterial strains: Staphylococcus aureus (ATCC 25923), Bacillus subtilis (NCTC 8236), Escherichia coli (ATCC 25922), Proteus vulgaris (ATCC 6380), Pseudomonas aeruginosa (ATCC 27853), Salmonella para typhi B (0650) and Klebsiella pneumoniae (ATCC 1312) using the Agar Diffusion Technique in vitro. Minimum Inhibitory Concentration (MIC) values were also determined for the most active plant extracts. Of all extracts the ethanolic extract of Pulicaria undulata was the most active, whereas, the aqueous extract of Ziziphus spina – christi stem bark was the most active of all aqueous extracts tested. The ethyl acetate extract of F. crispa showed activity against both Gram positive and Gram negative bacteria. Most susceptible Gram-negative bacteria were E. coli and P. vulgaris and least susceptible was S. para typhi B. In Gram –positive bacteria, most and least susceptible were S. aureus and B. subtilis respectively. The lowest MIC values were \u3c3.125 and 6.25 μg/ml for the crude extracts of ethyl acetate of Pulicaria undulata and crude methanolic extract of Ziziphus spinachristi, respectively. These results provide promising baseline information for the potential use of these crude extracts in the treatment of bacterial infections
L'impact de l'adoption des IFRS sur la divulgation des entreprises canadiennes
Dans ce mémoire, le travail de recherche consiste à analyser l'impact de l'adoption des normes IFRS, par les entreprises publiques canadiennes, sur leurs divulgations d'informations financières. Ainsi, il est organisé en deux grandes parties. La première partie (Chapitre I, II et III) met en évidence l'importance du rôle que joue la divulgation d'informations financières aujourd'hui au sein des entreprises publiques, elle met en relief aussi les différences entre les deux cadres conceptuels : Normes PCGR canadien par rapport aux normes IFRS. À cette étape, nous ne nous contentons pas seulement d'évoquer les arguments théoriques, nous avons analysé également certaines des preuves et évidences, issues d'études empiriques antérieures, qui soutiennent l'hypothèse que l'introduction des normes internationales d'information financière IFRS a eu un impact positif sur la divulgation financière. La deuxième partie du mémoire (chapitre IV et V) décrit la méthodologie retenue pour la mise en œuvre de cette recherche et présente les résultats obtenus. Au niveau méthodologique, nous avons choisi de comparer la quantité de divulgation d'information financière en nous basant sur deux indices. Le premier est simple, il s'agit du nombre de mots publiés, et le deuxième est un peu compliqué, il s'agit d'un score de divulgation par entreprise. Plus particulièrement, l'analyse empirique suggère : (1) que la quantité de divulgation de l'information financière obligatoire a augmenté, pour les entreprises publiques canadiennes, à la suite de l'adoption des normes IFRS; (2) que la quantité d'information obligatoire publiée par les entreprises n'est pas affectée par des contextes particuliers. Deux limites principales ont également été notées. D'une part, notre échantillon est relativement petit. Et d'autre part, nous nous sommes limités seulement aux normes comptables IFRS qui touchent l'actif des entreprises.\ud
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MOTS-CLÉS DE L’AUTEUR : Adoption obligatoire des normes IFRS, divulgation financière, Canada
Effet des extraits de compost sur la croissance mycélienne et l'agressivité du Fusarium oxysporum f. sp. radicis-lycopersici
Effect of compost tea on mycelial growth and disease severity of Fusarium oxysporum f. sp. radicis-lycopersici. Simultaneous addition, on culture media, of Fusarium oxysporum f. sp. radicis-lycopersici and compost teas revealed that the latest induced the inhibition of the mycelial growth of the pathogen. This inhibition, noted after an incubation period of about six days at 25°C, was more important when compost teas were enriched in PDB (Potato Dextrose Broth), where it may reach 70% compared to the control. Transplantation of tomato seedlings, previously inoculated by a conidial suspension of F. oxysporum f. sp. radicis-lycopersici, in a container media (peat, perlite or the mixture of the two substrates) treated by compost teas has signifi cantly reduced Fusarium crown and root rot incidence compared to inoculated and untreated control seedlings. Disease incidence is more reduced when tomato inoculated plants are transplanted in peat treated by compost teas; indeed, these plants donʼt show any wilting and present a vigorous root system and a better vegetative growth
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