On the Expedient Solution of the Boltzmann Equation by Modified Time Relaxed Monte Carlo (MTRMC) Method

In the present study, a modified time relaxed Monte Carlo (MTRMC) method is developed for numerical solution of the Boltzmann equation in rarefied regimes. Taylor series expansion is employed to obtain a generalized form of the Wild sum expansion and consequently the modified collision functions with fewer inter-molecular interactions are obtained. The proposed algorithm is applied on the lid-driven micro cavity flow with different lid velocities and the results for velocity and shear stress distributions are compared with those from the standard DSMC and TRMC methods. The comparisons show excellent agreement between the results of the MTRMC method with their counterparts from TRMC and DSMC methods. The present study illustrates appreciable improvement in the computational expense of the MTRMC method compared to those from standard TRMC and DSMC methods. The improvement is more pronounced compared to the standard DSMC method. It is observed that up to 56% reduction in CPU time is obtained in the studied cases

Bursts of activity in collective cell migration

Dense monolayers of living cells display intriguing relaxation dynamics, reminiscent of soft and glassy materials close to the jamming transition, and migrate collectively when space is available, as in wound healing or in cancer invasion. Here we show that collective cell migration occurs in bursts that are similar to those recorded in the propagation of cracks, fluid fronts in porous media and ferromagnetic domain walls. In analogy with these systems, the distribution of activity bursts displays scaling laws that are universal in different cell types and for cells moving on different substrates. The main features of the invasion dynamics are quantitatively captured by a model of interacting active particles moving in a disordered landscape. Our results illustrate that collective motion of living cells is analogous to the corresponding dynamics in driven, but inanimate, systems

Simvastatin attenuates intestinal ischaemia/ /reperfusion-induced injury in rat

Ischaemia/reperfusion (I/R) injury is commonly seen in the fiel

On the hybrid of fourier transform and adomian decomposition method for the solution of nonlinear cauchy problems of the Reaction-Diffusion equation

The physical science importance of the Cauchy problem of the reaction-diffusion equation appears in the modelling of a wide variety of nonlinear systems in physics, chemistry, ecology, biology, and engineering. A hybrid of Fourier transform and Adomian decomposition method (FTADM) is developed for solving the nonlinear non-homogeneous partial differential equations of the Cauchy problem of reaction-diffusion. The results of the FTADM and the ADM are compared with the exact solution. The comparison reveals that for the same components of the recursive sequences, the errors associated with the FTADM are much lesser than those of the ADM. We show that as time increases the results of the FTADM approaches 1 with only six recursive terms. This is in agreement with the physical property of the density-dependent nonlinear diffusion of the Cauchy problem which is also in agreement with the exact solution. The monotonic and very rapid convergence of the results of the FTADM towards the exact solution is shown to be much faster than that of the ADM. © 2012 Verlag der Zeitschrift für Naturforschung, Tübingen

Effects of alcoholic extract of Euphorbia cyparissias on spermatogenesis and serum level of testosterone in streptozotocin-induced diabetic rats

Diabetes mellitus is an endocrine disorder which is considered one of the main causes of mortality in developed countries. Long term use of the majority of synthetic anti-diabetic drugs lead to various side effects therefore the use of medicinal plants has currently become popular. Traditionally, Euphorbia cyparissias has been used for its anti-inflammatory, anti-oxidative and anti-neoplastic properties. In the present study 40 male Wistar rats were studied in four groups (n=10). The groups included: control, diabetic, alcoholic 500, alcoholic 250. The alcoholic groups received 250 and 500 mg/kg of alcoholic extract of Euphorbia cyparissias for 21 days through gastric gavage following induction of diabetes with streptozotocin. In control and diabetes induced groups an identical volume of physiological serum was gavaged. The testicular tissue and blood samples were obtained at the end of the experimental period for histological and blood testosterone concentration purposes, respectively. Results suggested that the serum glucose and testosterone concentrations in the control and alcoholic 500 groups had a significant difference with the other groups (

The HPM Applied to MHD Nanofluid Flow over a Horizontal Stretching Plate

The nonlinear two-dimensional forced-convection boundary-layer magneto hydrodynamic (MHD) incompressible flow of nanofluid over a horizontal stretching flat plate with variable magnetic field including the viscous dissipation effect is solved using the homotopy perturbation method (HPM). In the present work, our results of the HPM are compared with the results of simulation using the finite difference method, Keller's box-scheme. The comparisons of the results show that the HPM has the capability of solving the nonlinear boundary layer MHD flow of nanofluid with sufficient accuracy

Effect of alcoholic extract of Euphorbia cyparissias on the brain antioxidant enzymes in streptozotocin-induced diabetic male rats

Background: Diabetes is a chronic disease characterized by metabolic disorders of proteins, fats and carbohydrates. Long-term use of the blood glucose lowering drugs can cause side effects. The purpose of this study was to examine the effect of the alcoholic extract of E. cyparissias on the level of brain antioxidant enzymes in streptozotocin-induced diabetic male rats. Materials and Methods: In this study, 40 adult male Wistar rats (250±20 gr) were divided randomly into 4 groups: 1) control 2) streptozotocin-induced diabetic 3) treatment1: received 500 mg/kg of the extract and 4) treatment 2: received 250 mg/kg of the extract. The two treatment groups received the alcoholic extract through gastric gavages for 21 days. At the end of the treatment, the blood glucose and levels of brain antioxidant enzymes (TAC, MDA, SOD and GPX) were determined. Results: Results showed that the MDA level was significantly increased in brain tissue in the diabetic group compared to the control group (P=0.001). Furthermore, the levels of TAC, SOD and GPX were significantly decreased in brain tissues in the diabetic group compared to the control group (P=0.001). Similar results were obtained for the blood glucose level. Conclusion: It can be concluded that oral administration of E. cyparissias alcoholic extract has the antidiabetic and antioxidant activities in the streptozotocin-induced diabetic rats