17 research outputs found
اختبار القدرة على التنبؤ بعوائد مؤشر سوق الدار البيضاء المالي من 2007 إلى 2011
تهدف هذه الدراسة إلى اختبار ما إذا كانت سلسلة عائد المؤشر العام لسوق الدار البيضاء مستقلة فيما بينها وتتبع السير العشوائي، حيث قمنا بتقدير مدى انحراف سلسلة مؤشر العائد عن الكفاءة على المستوى الضعيف من خلال اختبار القدرة على التنبؤ بالعوائد على المدى القصير، باقتراح نموذج وقد شملت العينة بيانات تاريخية لسعر إغلاق المؤشر العام لسوق الدار البيضاء، خلال الفترة من 2007 إلى 2011، وهي مشاهدات يومية، تبلغ 827 مشاهدة، وقد وجدنا أن النموذج المقترح أفضل من نموذج السير لعشوائي من حيث الجودة التنبؤية، وأن عوائد مؤشر سوق الدار البيضاء المالي قابلة للتنبؤ على المدى القصير، وحركة الأسعار تظهر كنتيجة لصدمة خارجية عابرة ، وبالتالي فالسوق لا يعتبر كفؤا عند المستوى الضعيف.
The study aims to test whether the Casablanca Stock exchange returns are independent and identically distributed (i.i.d.). We use ARIMA(1,1,0)-GARCH(1,1) model to test the forecastability of stock exchange returns series. The empirical study focuses on the logarithmic series of daily Moroccan stock exchange series covering a historical period from 2007 to 2011. We have found that the proposed model is better than the random walk model in terms of predictive quality, and the Casablanca Stock exchange returns is predictable for short-term and the price movements appear as a result of transitory exogenous shock, therefore the weak efficiency assumption of financial markets seems violated
Evaluation of the Acute Toxicity of Dandelion (Taraxacum officinale) Roots
Introduction: Dandelion (Taraxacum officinale) is a medicinal plant used in alternative medicine for its multiple therapeutic and preventive properties. However, insufficient data are available about its toxicity.
Materials and methods: dandelion roots total extract vas prepared by maceration for 24 hours and its toxicity was then assessed on 30 WISTAR male rats divided into four experimental groups receiving the extract at different rates, and one control group treated with the vehicle. Changes in renal, hepatic, lipid, and hematological parameters as well as signs of acute toxicity were noted during 15 days after the one dose extract administration.
Results and discussion: The obtained results reveal a very significant (p<0.01) disruption of transaminases but not renal, lipid and hematological parameters.
The acute toxicity study demonstrated that dendelion roots extract has low intraperitoneal toxicity with a LD50 ranged between 500 and 5000 mg/kg.
Conclusion: Dandelion's richness in secondary metabolites and its low in vivo toxicity make it a good candidate as a source of drugs with anti-inflammatory and anti-cancer properties.
Keywords: Dandelion, Acute toxicity, LD50, Transaminases, lipids, hematolog
EFFECT OF DURUM WHEAT BRAN ON GLUCOSE AND LIPID METABOLISM IN DIABETIC RATS.
Introduction: Durum wheat bran is obtained from wheat milling, it’s considered as an excellent source of insoluble dietary fibre. Objective. The aim of this paper was to evaluate the effect of wheat bran (WB) on glucose and lipid metabolism in normal and diabetic rats. Materials and Methods. Twenty-four female rats of "Wistar" were divided into four groups each containing six rats. The first group (NCR) was fed by a control diet while the second group (NCRE) was fed by the experimental diet based on durum wheat bran. For the third and fourth group after streptozotocin (STZ) injection, they were fed by a control diet (DCR) and experimental diet (DRE) respectively. The Blood Glucose (g/L) and weight (g) of these groups was measured at the end of each week for a period of four weeks, the serum lipid parameters in the fasting condition, such as TC, TG, LDL-C and HDL-C were evaluated at the end of the experience. Results. WB was high in dietary fibre (41%). The results show a significant decrease in blood glucose ( p<0.04) and body weight ( p<0.05 ) in DRE group compared to DCR group and non-diabetic groups. No significant difference was observed for cholesterol and triglyceride levels, a difference of p<0.05 for HDL-C was observed between the diabetic experimental diet group and the non-diabetic control diet group. For LDL-C, the difference was observed between the diabetic experimental group and the non-diabetic experimental group (p<0.001). Conclusion Our results indicated that WB exerting a glycemic and a serum lipid regulation effect in experimental diabetic rats
Epidemiological Approach and Precocious Diagnosis of Precancerous Cervical Lesion in Sidi Bel Abbes Region (North-West of Algeria)
Object: Cervical cancer of the uterine (CCU) is the first cancer of the genital tract. In Algeria, this cancer remains a real public health problem. The diagnosis is still done often with advanced stages which makes the therapeutic results modest and the cost of the high care. Methodology: Our study aims to elucidate the reality of this type of pathology in the region of Sidi Bel Abbes, northwestern Algeria. This retrospective and descriptive study was devoted to the epidemiological and clinical analysis of cervical cancer cases over a period of 3 years. Results: This study shows that out of a total of 500 smears recorded between (2014-2016) at the Ana-pathology laboratory level in Sidi Bel Abbes, we found that 230 smears presented precancerous lesions according to a cytological study, atypical squamous cells of undetermined significance (ASC-US: were 18%; low-grade squamous intraepithelial lesions (LSIL) were 20%, while high-grade squamous intraepithelial lesions (HSIL) were 8%. The results obtained according to the distribution of the patients in relation to the various factors: the most affected age group is late 46-55 years with a total of 40%; precocious age of 1st report 18-20 years is (38.2%); gestation 4-5 pregnancies and parities 4-5 children with a rate of (38.70% and 32.6%) respectively ; the hormonal state in genital activity is estimated at 62.2%; patients on oral contraception (OC) have a rate of 48.9%. Finally, more than half of the patients (57.8%), were able to have a biopsy within three to four months of the last smear.
In histology, the presence of a HPV (Human Papilloma Virus) low grade lesion does not predict the evolution of this lesion. Conclusion: HPV can be oncogenic or non-oncogenic. it is the oncogenic HPV infection that is the main risk factor for developing a high grade lesion and cervical cancers outside the associated cofactors.
Keywords: Pap Smear, Precancerous lesion, Cancer, Cervix, Screenin
ETUDE PHARMACOCHIMIQUE D'UN NOUVEL ANTAGONISTE DE L'ANGIOTENSINE II LE TELMISARTAN OU PRITOR*
AIX-MARSEILLE2-BU Pharmacie (130552105) / SudocSudocFranceF
Research of the Causes and Risk Factors of Autism in the Western Region of Algeria
Introduction Autism is a neurodevelopmental disorder that manifests before 3 years old and affects many areas, communication, social interactions and behaviors. In Algeria, there has not yet been a regional or national epidemiological investigation concerning autism spectrum disorders.
Materials and methods: Our study was carried about 100 patients ( autistic children) in the western region of Algeria, in order to determine the differents risk factors involved in the onset of autism syndrome.
Results and discussion: The obtained results indicate a male predominance with a sex ratio of 4: 1 and the degree of reached is average in 44% of patients. 42% of the patients are youngsters. Parents' worry about their children begins between 24 and 36 months. The parents' advanced age at conception, stress, presence of certain pathologies and drug intake by mothers, as well as fetal distress at birth and children's exposure to screens were the main risk factors. Repetitive movements, lack of social communication, language delay, and lack of visual fixation were the main clinical symptomatology.
Conclusion: This study allowed us to detect the main factors associated with the onset of autism. However, the results obtained cannot be generalized to the entire population.
Keywords: Autism, autism spectrum disorder, risk factors, clinical symptoms, western region of Algeria
Thermal Decomposition, Low Temperature Phase Transitions and Vapor Pressure of Less Common Ionic Liquids Based on the Bis(trifuoromethanesulfonyl)imide Anion
International audienceFour ionic liquids (ILs) based on the bis(trifluoromethanesulfonyl)imide (NTf 2) anion were synthesized and characterized concerning their thermal stability, the occurrence of low temperature phase transitions and their volatility. All these physical quantities are highly important for possible applications. Both monocationic and dicationic ILs were considered. All ILs exhibit thermal stability exceeding 350 • C, an extremely high value, due to the presence of the NTf 2 anion. Monocationic ILs can undergo crystallization, and they melt at 1 and 38 • C. On the contrary, dicationic ILs containing large positively charged ions display only a glass transition around −40 • C, without any crystallization or melting process; this fact is particularly important in view of the possibly low temperature applications of the dication ILs. The vapor pressure, p v , of the four ILs was measured by isothermal thermogravimetry in the temperature range between 250 and 325 • C; the lowest values of p v were obtained for the two dicationic liquids, suggesting that they are particularly well suited for high temperature applications. The vaporization enthalpy was calculated through the Clausius-Clapeyron equation and was found in the range between ~140 and ~180 kJ/mol depending on the specific IL
3D magnetic equivalent circuit model for homopolar hybrid excitation synchronous machines
International audienc
Synthesis, NMR, vibrational spectroscopy, thermal and DFT studies of new DABCO hexafluorophosphate based ionic liquid
International audienceIn this paper, a new ionic liquid; [C8DABCO+][PF6−] was prepared, its structure was well confirmed by 1H, 13C, 19F and 31P–NMR spectroscopies. Besides, thermal behaviour has been discussed through TGA and DTA in the temperature range from [-80 to 200 °C] and [25 to 700 °C] respectively. Theoretical studies were performed by DFT method to investigate the structural, electronic and topological properties. B3LYP/6–31G* calculations support the high solvation energy value of IL in aqueous solution (ΔGc= -122.9 kJ/mol) and it probably explain the high dipole moment value, the volume expansion in this medium (7.3 Å3) and also because the cation-anion interactions still remain in solution. Seven interactions were predicted by AIM calculations but only two cation-anion interactions have short distances. NBO studies reveal that IL is more stable in solution probably due to its higher solvation energy. The DOS spectrum in aqueous solution shows clearly that the orbitals belonging to the atoms of cage-like DABCO structure participle in both HOMO and LUMO and, hence, will confirm that DABCO is engaged in halogen interactions, as suggested from NBO analyses. These studies show that DABCO structure participates in the properties of [C8DABCO+][PF6−]. Complete assignments of IR and Raman spectra were reported
Limiteurs de courant supraconducteurs
50-60 Hz electrical engineering represents a considerable potential market for superconductors. Fault current limitation will probably be the first among the possible applications, to find an industrial opening. Exploited features are very specific of the superconductors, namely the large contrast existing between an on-state with high current density and an off-state with high electrical resistivity, obtained as soon as the current reaches a specified level. It thus becomes possible to warrant the grid from any current excursion over a specified value, with considerable impact on the protection and dimensions of conductors and devices, and increased possibilities of interconnexion. The current limiter technology is rather complex ; different structures have been proposed and tested ; they are resistive or inductive, based on low- or high- superconductors. The most advanced candidate to date is a resistive structure, using conductors made of ultra-fine niobium-titanium filaments in a coppemickel matrix, whose essential features are described hereunder.L'électrotechnique industrielle à 50-60 Hz représente pour les supraconducteurs un marché potentiel considérable. Parmi les applications envisageables, la limitation des courants de défaut sera probablement la première à trouver un essor industriel. Les propriétés mises en jeu sont tout à fait spécifiques des supraconducteurs, à savoir le grand contraste existant entre un état passant à haute densité de courant, et un état bloquant à haute résistivité, obtenu dès que le courant dépasse un seuil donné. Il est ainsi possible de garantir le réseau contre toute excursion du courant au-delà d'une valeur spécifiée, avec un impact important sur sa protection, son dimensionnement, son degré d'interconnexion. La technologie du limiteur de courant est assez complexe ; diverses structures ont été proposées et testées, résistives ou inductives, à base de supraconducteurs BT ou HT. Le candidat le plus avancé à ce jour est une structure de type résistif, utilisant des conducteurs à filaments ultra-fins de niobium-titane et à matrice de cupronickel, dont on donne ici les caractéristiques essentielles