La conception d'un quantificateur vectoriel robuste aux erreurs du canal

Nous vivons dans l'ère des télécommunications. Les radio-mobiles, le multimédia et les communications globales font déjà partie de notre langage quotidien. La société devient de plus en plus complexe et les besoins de stockage et de communication s'accroissent rapidement. La course à la compression des données est motivée par la théorie du codage de source de Shannon. Lorsque l'information de source est comprimée et codée de façon très efficace, et qu'elle est transmise sur un canal bruité, les performances prévues par le système de codage de source sont très rapidement dégradées. C'est Shannon lui-même qui vient au secours, dans ce cas, en assurant l'existence de schémas de codage de canal capables d'atteindre le modèle de 'canal sans bruit'. Ce résultat fondamental de la théorie de l'information a permis de traiter le problème de codages de source et de canal de façon complètement séparée, sans aucune perte d'optimalité par rapport à un système globalement optimal. Le travail réalisé au cours de ce projet est motivé par l'augmentation des besoins en codage bas-débit des systèmes basés sur la quantification vectorielle et utilisant des canaux bruités, comme les communications radio-mobiles de la parole. Dans ce mémoire de maîtrise, on présente ainsi les techniques visant à combattre efficacement la dégradation de la performance causée par les canaux bruités

ظاهرة التكتلات الاقتصادية وإشكالية الأزمات الرأسمالية دراسة تحليلية لأثر التكتلات كقوة ممانعة وكمعبر للتدويل

في أعقاب الحرب العالمية الثانيةوعلى إثر الأعطاب التي أفرزتها، تظافرت الجهود في سياق ترميم تلكم الاختلالات المتعددة الصُعد، وقد ارتكزت السياسات الإصلاحية في جوهرها على مرجعيات الفكر الليبرالي، وضمن سياق محاولات الرأسمالية لتجديد نفسها وتجاوز إشكالية تلك الوصمات والأزمات، طفت مذ ذلك الحين ظاهرة التجمعات الاقتصادية (المؤسساتية والجغرافية)، وغزت المشهد الاقتصادي الدولي كطرح جديد لتجاوز مشكلات الرأسمالية الليبرالية الجديدة. لكن الإشك آلية اليوم أن الأزمة تنمطت وبات انتشارها أسرع مما كان عليه، بسبب غير قليل من قنوات التدويل، والتي أقحمت فيها التكتلات الاقتصادية كجدلية بين ذلك وبين النقيض، أي بين اعتبار التكتلات معبرا لتدويل الأزمات وبين تصنيفها كآلية لصد الانتشار الدولي للاختلالات الرأسمالية الراهنة. ومن خلال هذه الدراسة سنحاول التطرق لأهم الأطروحات التي تتعلق بتدويل الأزمات أو ممانعتها ارتكازا على الدور الذي تسهم فيه التكتلات الاقتصادية

ظاهرة التكتلات الاقتصادية وإشكالية الأزمات الرأسمالية دراسة تحليلية لأثر التكتلات كقوة ممانعة وكمعبر للتدويل

في أعقاب الحرب العالمية الثانيةوعلى إثر الأعطاب التي أفرزتها، تظافرت الجهود في سياق ترميم تلكم الاختلالات المتعددة الصُعد، وقد ارتكزت السياسات الإصلاحية في جوهرها على مرجعيات الفكر الليبرالي، وضمن سياق محاولات الرأسمالية لتجديد نفسها وتجاوز إشكالية تلك الوصمات والأزمات، طفت مذ ذلك الحين ظاهرة التجمعات الاقتصادية (المؤسساتية والجغرافية)، وغزت المشهد الاقتصادي الدولي كطرح جديد لتجاوز مشكلات الرأسمالية الليبرالية الجديدة. لكن الإشك آلية اليوم أن الأزمة تنمطت وبات انتشارها أسرع مما كان عليه، بسبب غير قليل من قنوات التدويل، والتي أقحمت فيها التكتلات الاقتصادية كجدلية بين ذلك وبين النقيض، أي بين اعتبار التكتلات معبرا لتدويل الأزمات وبين تصنيفها كآلية لصد الانتشار الدولي للاختلالات الرأسمالية الراهنة. ومن خلال هذه الدراسة سنحاول التطرق لأهم الأطروحات التي تتعلق بتدويل الأزمات أو ممانعتها ارتكازا على الدور الذي تسهم فيه التكتلات الاقتصادية

Nutritional Status and School Achievements in a Rural Area of Anti-Atlas, Morocco

ABSTRAC

Histo-epidemiological aspect of Helicobacter pylori chronic gastritis in a Moroccan population

Helicobacter pylori (H. Pylori) is the best example of the implication of chronical infection in carcinogenesis. The World Health Organization recognized it as a class I carcinogen since it triggers the progression of premalignant gastric lesions. The aim of this study is to define the prevalence of H. Pylori infection, related risk factors, and explore the histological features of the chronic gastritis. This is a retrospective study of 248 gastric specimens, examinated and evaluated according Sydney to system. The prevalence of H. Pylori is 67 %, chronic gastritis is observed in all the biopsies (100%). Age and gender were not a risk factors for the H. Pylori infection. Prevalence of H. Pylori was 71.93% in low socio-economic class. The severity of the chronic gastritis increases if the colonization of H. Pylori increases. In 74, 58% of cases chronic gastritis was active. Glandular atrophy presented 10.37% and in 80% was related to H. Pylori infection (p=0,004) and 12 % related to autoimmune diseases. The prevalence of Intestinal metaplasia is 10.53%, and H. Pylori was observed in 42.31% of cases (p=0.001). The dysplasia is detected in one case, in a 72 years old patient. We also observed one case of gastric adenocarcinoma, of an 80 years. Follicular gastritis are in 32% of cases, and they were more frequent in H. Pylori infected slides (82% of subjects) (p< 0.005).According to this study, H. Pylori Chronic Gastritis is very common in our population, and a coherent relationship exists between H. Pylori colonization and pre-cancerous lesions. An early eradicating should be considered as a health goal

Anemia In A Moroccan Hospital Setting: Case Of Regional Hospital “Idrissi”, Kenitra

Abstract: Anemia remains a public health problem in the World. Nationally, more than one third of the women and under five children are affected. Aim: To assess anemia typology of adults in a hospital setting and study the impact of socio-demographic factors on the occurrence of anemia and make a typology using haemogram. Method: Eighty two adult patients (42 women and 40 men) were observed in an internal medical unit in the Idrissi hospital-Kenitra, Morocco. The only inclusion criteria were anemia status (less than 10g/dl Hemoglobin). Results: Level of instruction of patients varies remarkably with age, sex and area of residency. Poverty and inaccessibility to health facilities have an impact on the apparition of anaemia. At the biological aspect, the microcytic anaemia is the frequent form with 39%, while the macrocytic represents 37.8 % and normocytic one affects 23.2 % of the subjects. According to TCMH levels, hypochromic anemia is found in 63.4 % and normochromic in 36.6%. Severe anemia (HB&lt;6.5 g/dL) is the major prevalent form in old as well as young women. Conclusion: Anemia is a frequent affection in this hospital setting. Its severity is associated with weakness of immunity defense and many inherent diseases

Cellulose polymers with β-amino ester pendant group: design, synthesis, molecular docking and application in adsorption of toxic metals from wastewater

Abstract Background Cellulose polymers with multidentate chelating functionalities that have high efficiency for toxic metal ions present in water were designed, synthesized, and analyzed. The synthesis was carried out by reacting microcrystalline cellulose extracted from the solid waste of the olive industry with tert-Butyl acetoacetate (Cell-AA), produced cellulose with β-ketoester functionality was then reacted with aniline and the amino acid glycine to produce Cell-β-AN and Cell-β-GL, respectively. Results The adsorption efficiency of the three polymers toward Pb(II) and various toxic metal ions present in sewage was evaluated as a function of adsorbent dose, time, temperature, pH value, and initial ion concentration to determine optimum adsorption conditions. The three polymers showed excellent efficiency toward about 20 metal ions present in a sewage sample collected from the sewer. The adsorption process follows the Langmuir adsorption isotherm model with a second-order of adsorption rate, the calculated qe values (2.675, 15.252, 20.856 mg/g) were close to the experimental qe values (2.133, 13.91, 18.786 mg/g) for the three polymers Cell-AA, Cell-β-AG and Cell-β-AN, respectively. Molecular Dynamic (MD) and Monte Carlo (MC) simulations were performed on the three polymers complexed with Pb(II). Conclusion The waste material of the olive industry was used as a precursor for making the target cellulose polymers with β-Amino Ester Pendant Group. The polymer was characterized by SEM, proton NMR, TGA, and FT-IR spectroscopy. The efficacy of adsorption was quantitative for metal ions present in a real sample of wastewater and the efficiency didn’t drop even after 7 cycles of use. The results indicate the existence of strong complexation. The thermodynamic study results showed a spontaneous bonding between of Pb(II) and the polymers pendant groups expressed by the negative value of the Gibbs free energy

Rosmarinus officinalis L. leaf extract improves Anxity impairment induced by tropane alkaloids extracted from Datura stramonium

The alkaloid extract of datura stramonium (rich of atropine, hyoscyamine, scopolamine) is used to evaluate its effect on the central nervous system in rats (locomotion, anxiety). The animals received the alkaloid extract of datura by intraperitoneal injection. However, after the injection a group of rats got an inhibitory treatment contain flavonoids extracted from Rosmarinus officinalis. At the dose of 50 mg/kg/body weight of the alkaloid extract, the female rats have shown a reduction of locomotor activity and an induction of an anxiogenic effect. In the other hand, the mixture of Datura stramonium and Rosmarinus officinalis showed a neuroprotective action with regard to the disorders induced by extracts of Datura stramonium