The effect of eight weeks of resistance training on activin receptor type II-B and plasma levels of growth differentiation factor 11 and 8 in cardiac physiological hypertrophy in male wistar rats

Background: Exercise training can be effective on cardiac physiological hypertrophy (that is favorable for cardiac function) by changing the concentration of growth factors and their receptors. The aim of this study was to determine the effects of eight weeks of resistance training on activin receptor type II-B (ActRIIβ), as well as plasma levels of growth differentiation factor 11 (GDF11) and growth differentiation factor 8 (GDF8) in cardiac physiological hypertrophy in male Wistar rats. Methods: After the familiarization period, fourteen 3-month-old male Wistar rats were randomly divided into control and training groups (n= 7). Resistance training included 8 weeks and 5 sessions per week climbing from a 1-meter ladder. GDF11 and GDF8 of plasma were measured using enzyme-linked immunosorbent assay (ELISA) method, and ActRIIB of left ventricular myocardium was measured using immunohistochemistry (IHC) method. Data were analyzed using independent t test and Mann-Whitney U at the significance level of P < 0.050. Findings: There was a significant difference between the training and control groups in heart weight (P = 0.004), heart weight/body weight (P =0.045), GDF11 (P = 0.001), and GDF8/GDF11 (P = 0.015). There was not any significant differences between the training and control groups in ActRIIβ (P = 0.768) and GDF8 (P = 0.295) levels. Conclusion: According to the results of the present study, it seems that resistance training with favorable effects on growth factors is an important strategy in cardiac physiological hypertroph

Grid and subgrid-scale interactions in viscoelastic turbulent flow and implications for modeling

Using direct numerical simulations of turbulent plane channelflow of homogeneous polymer solutions, described by the FinitelyExtensible Nonlinear Elastic-Peterlin (FENE-P) rheological constitutive model, a-priori analyses of the filtered momentum and FENE-Pconstitutive equations are performed. The influence of the polymeradditives on the subgrid-scale (SGS) energy is evaluated by comparing the Newtonian and the viscoelastic flows, and a severe suppression of SGS stresses and energy is observed in the viscoelastic flow.All the terms of the transport equation of the SGS kinetic energy forFENE-P fluids are analysed, and an approximated version of this equation for use in future large eddy simulation closures is suggested.The terms responsible for kinetic energy transfer between grid-scale(GS) and SGS energy (split into forward/backward energy transfer) areevaluated in the presence of polymers. It is observed that the probability and intensity of forward scatter events tend to decrease in thepresence of polymer

FLOOD ZONING USING THE HEC-RAS HYDRAULIC MODEL IN A GIS ENVIRONMENT

This research estimates the flood zone and economic damages over an 8.2 km reach of the perennial Laeen Soo River in the northern Khorasan Province, Iran, using HEC-GEORAS, a combination of HEC-RAS with Arcview GIS software. The 1:500 map of the Khorasan water district has been used, and the land use of the region was classified into 16 types. The roughness coefficient of each land use for four seasons of the year was estimated separately, using two general methods of the U.S. Soil Conservation Service (SCS) and standard tables. The flood zones for floods with return periods of 10 to 200 years were calculated. The results showed that the combination of GIS with the HEC-RAS model was very powerful and efficient in flood zone analysis. The studies on the Laeen Soo River showed that the zone of a flood in summer was more extensive than other seasons, and the SCS method gave a higher Manning coefficient. It is recommended that for flood zoning of the Laeen Soo River, that the summer be chosen as the design criterion and the SCS method as the method of Manning coefficient estimation