Abstract: Keeping in mind the applications of the flow through porous medium in geophysics, particularly in the study of earths core, importance of viscoelastic fluids in industry and chemical technology and presence of dust/suspended particles in fluids; the hydromagnetic stability of stratified Rivlin-Ericksen fluid saturating a porous medium in the presence of rotation is presented. The stability of the motionless horizontal layer of the fluid having vertical stratifications of the physical parameters; density, viscosity, viscoelasticity, medium porosity, medium permeability, particle number density and magnetic field is considered. After linearizing the relevant hydromagnetic equations, the perturbed quantities are analysed in terms of normal modes. Dispersion relation governing the effects of viscoelasticity, porosity, medium permeability, suspended particles, rotation and magnetic field on the stability of Rivlin-Ericksen fluid is derived. The system is found to be stable for the case of stable stratification as in the case of Newtonian fluids. For the case of unstable stratification, magnetic field succeeds in stabilizing the otherwise unstable system for certain wave number range. The behavior of growth rates with respect to Alfven velocity, medium permeability, suspended particles and angular velocity are found analytically as well as numerically. It has been found that the growth rate decreases with the increase in Alfven velocity and angular velocity; and it increases with the increase in medium permeability and suspended particles.

Abstract: Thromboxane synthase (CYP5A1) catalyzes the conversion of prostaglandin H2 to thromboxane A2, a potent mediator of platelet aggregation, vasoconstriction and bronchoconstriction. It has been implicated in the patho-physiological process of a variety of diseases, such as atherosclerosis, myocardial infarction, stroke and asthma. Variations of the CYP5A1 gene may play an important role in human diseases, therefore, we performed screening for the prevalence of exon12 polymorphism of the human CYP5A1 gene among Egyptian normal and stroke patients. Using sequence-specific PCR, we examined the allelic prevalence in 70 Egyptian patients with ischemic strokes and in 70 controls. In addition, we compared the CYP5A1 allelic prevalence in 30 patients with stroke recurrence despite Aspirin use, in comparison with patients who have not experienced recurrent stroke while taking Aspirin. The frequencies of the CYP5A1*9 mutant (substitution of guanine by adenine near the hemebinding catalytic domain) and of the wild-type allele were 0.197(19.7%) and 0.803 (80.3%) respectively; they did not differ significantly between stroke patients and controls. The CYP5A119 mutant was significantly more prevalent among stroke patients with history of previous cerebrovascular attacks; even after adjusting for the common risk factors for cardiovascular disease [odds ratio (OR) 1.73, 95%, confidence interval (CI) 1.10?2.73; p=0.017]. Among stroke patients, the presence of the CYP5A1 wild type allele was more frequent among the hypertensives (OR 1.68, 95% CI, 1.01?2.79; p=0.045), and less frequent among the diabetics (OR 0.55, 95%, CI 0.36?0.84; p=0.006). Also, the CYP5A1*9 mutant was significantly more prevalent among those, who failed secondary Aspirin prophylaxis compared to those with successful secondary Aspirin prophylaxis (OR 1.49, 95%, CI 1.06?2.11). This study provides evidence for high prevalence of the CYP5A1*9 mutant among the Egyptian population. The presence of a mutant, affecting the heme-binding site of the enzyme, is possibly associated with recurrent cerebrovascular attacks in patients who fail secondary prophylaxis with Aspirin, an effect independent of the conventional risk factors for cerebrovascular disease.

Abstract: The aim of this work was to study the interactions of methyl-parathion (MP) with human (HSA), bovine (BSA) and fish (FSA) albumins by using the fluorescence quenching technique. The fish species used was the pacu (Piaractus mesopotamicus), a typical inhabitant of Brazilian rivers. MP is a pesticide still used in agriculture and fish hatcheries in many countries. Methods: MP was purified from a commercial grade preparation by thin layer chromatography, using dichloromethane as the mobile phase. HSA and BSA were purchased from chemical company. FSA was isolated from the pacu serum by affinity chromatography. We excited the intrinsic fluorescence of the tryptophan in albumins and observed the quenching by titrating the protein solutions with MP. The Stern-Volmer graphs were plotted and the quenching constants were evaluated. Results: The titration of HSA and BSA at 25?C produced linear Stern-Volmer plots. At 37oC, the plot is still linear for HSA, but not for BSA. The titration of pacu albumin by the pesticide at 20?C, 25?C and 30?C showed relevant slope deviations by the temperature changes. This behavior of Stern-Volmer plot of pacu albumin is analogous to the BSA. Examining the influence of the temperature at low MP concentrations on the plots, we found the occurrence of static quenching for the three albumins. Conclusions: (1) The three studied albumins interact with MP to form complexes. (2) The pprimary binding sites for the pesticide on HSA and BSA are close to tryptophan residues 214 and 212, respectively. (3) Estimated association constants for HSA and BSA were, respectively: 3.07x104 (?1.2x103) M-1 and 1.96x104 (?4.5x102) M-1 at 25?C; 1.08x104 (?2.0x102) M-1 and 8.16x103 (?1.9x102) M-1 at 37?C. (4) For pacu albumin, the Stern-Volmer constants were 1,19x104 (?3,4x102) M-1 at 20?C, 9,73x103 (?4,9x102) M-1 at 25?C, 9,37x103 (?4,4x102) M-1 at 30?C. Small

Abstract: Within the framework of the search for producing thermophilics micro-organisms of xylanases thermostable used in the industry of the paper mill and another can be used in dye industry, nutrition (diabetes) and in the exploration of intestinal permeability (changed to Dxylose, absorbed by the intestine after ingestion, not metabolized, excreted in the urine). The sifting of the xylanolytic activity of some Actinomycetes thermophilics made it possible to select a stock potentially more active and thermostable. Thus, starting from the chicken compost (Annaba, Algeria), three thermophilics stocks of Actinomycetes are insulated and identified by molecular techniques (PCR) while being based on gene ARNr 16S and sequencing of the totality of the fragment (1511 bp) with alignment with the BLAST confirming their membership of the Actinomadura kind. The isolated stocks autochtones are new species from where interest to develop them. Among these three stocks, the secret species Actinomadura keratinilytica Cpt 20 a very active and thermostable xylanase. In addition part of the gene xylanase (probe xylanase) of size 320 bp is isolated and sequenced, which made it possible to genetically attach this enzyme to the family of the beta (1-4) endoxylanases. The totality of gene is isolated in two fragments from sizes respectively 700 bp and 500 bp (cloning) are in the course of work for if required gathering the two fragments (assembly PCR) and characterizing the totality of gene.

Abstract: Angelman syndrome (AS) is a neuro-developmental disorder which arises from molecular genetic defects and is characterized by severe mental retardation, severe speech/ language delays, ataxia, seizures, frequent outbursts of laughter. In addition to a happy/sociable disposition, other characteristics of the behavioral phenotype include hyperactivity, hand-flapping, and fascination with water. Autism is characterized by deficits in communication and reciprocal social interaction, accompanied by repetitive/ stereotypic behaviors. The study reviewed a child diagnosed with Angelman syndrome and Autism Spectrum Disorder (ASD) based on clinical features exhibited at that time. But after intervention for one year, re-assessment was done which showed that ASD features were minimal; highlighting the importance of constantly reviewing the child holistically in terms of diagnosis, present level of performance and progress made.