RESUMEN
The Mancha3D code is a versatile tool for numerical simulations of magnetohydrodynamic (MHD) processes in solar/stellar atmospheres. The code includes nonideal physics derived from plasma partial ionization, a realistic equation of state and radiative transfer, which allows performing high-quality realistic simulations of magnetoconvection, as well as idealized simulations of particular processes, such as wave propagation, instabilities or energetic events. The paper summarizes the equations and methods used in the Mancha3D (Multifluid (-purpose -physics -dimensional) Advanced Non-ideal MHD Code for High resolution simulations in Astrophysics 3D) code. It also describes its numerical stability and parallel performance and efficiency. The code is based on a finite difference discretization and a memory-saving Runge-Kutta (RK) scheme. It handles nonideal effects through super-time-stepping and Hall diffusion schemes, and takes into account thermal conduction by solving an additional hyperbolic equation for the heat flux. The code is easily configurable to perform different kinds of simulations. Several examples of the code usage are given. It is demonstrated that splitting variables into equilibrium and perturbation parts is essential for simulations of wave propagation in a static background. A perfectly matched layer (PML) boundary condition built into the code greatly facilitates a nonreflective open boundary implementation. Spatial filtering is an important numerical remedy to eliminate grid-size perturbations enhancing the code stability. Parallel performance analysis reveals that the code is strongly memory bound, which is a natural consequence of the numerical techniques used, such as split variables and PML boundary conditions. Both strong and weak scalings show adequate performance up to several thousands of processors (CPUs).
RESUMEN
The genetic control of the traits "plant height", "the number of lateral shoots" and "the number of lateral stems" has been studied in 3 pure lines and 1 variety of linseed according to the model 1 of Hayman method. It has been shown that the traits under investigation are inherited according to the additive-dominant model of genetic control in the absence of any interloci interactions. The higher plant height and numerous lateral shoots are recessive traits controlled by 2 blocks of polymeric genes, whereas the trait of numerous lateral stems is a dominant trait influenced by 1 to 3 blocks of genes. The linseed lines have been ranked according to the number of dominant alleles they have. Suggestions for selection using these parental genotypes have been made.
Asunto(s)
Lino/crecimiento & desarrollo , Lino/genética , Sitios de Carácter Cuantitativo/genética , Carácter Cuantitativo Heredable , Alelos , Cruzamientos Genéticos , Genes Dominantes , Modelos GenéticosRESUMEN
Combining ability for the traits of stem branching and plant height has been studied in ten pure lines of flax under complete and incomplete diallel crosses. High heritability of the traits "plant height", "the number of lateral stems" and "the number of lateral shoots" and essential role of genes with dominant effects of interaction in genetic control of the traits of stem branching and plant height have been shown. On the basis of combining ability indexes the ways for usage of certain genotypes and crossing combinations in flax breeding were defined. As a result of individual selection from hybrid combinations some new complexes of habit traits and agriculturally valuable plant characteristics were obtained.
Asunto(s)
Lino/genética , Brotes de la Planta/genética , Tallos de la Planta/genética , Carácter Cuantitativo Heredable , Selección Genética , Alelos , Biometría , Cruzamientos Genéticos , Lino/anatomía & histología , Genes Dominantes , Genotipo , Fenotipo , Brotes de la Planta/anatomía & histología , Tallos de la Planta/anatomía & histologíaRESUMEN
Influence of selection of F1 high temperature tolerant pollen on the structure of BC1 segregating populations was studied for a number of agronomically important traits in oil flax. It was found that heat treatment of heterogeneous pollen population considerably changed genetic composition of plant population not only for tolerance to drought but for duration of seedling emergence--flowering period and quantity and inclination angle of side shoots as well. It is supposed that genes which confer these traits are at least partially linked to the genes responsible for pollen sensitivity to high temperature.
Asunto(s)
Lino/genética , Adaptación Fisiológica/genética , Lino/fisiología , Polen , Selección GenéticaRESUMEN
The main causes restraining the introduction of computers in medical establishments have been analyzed. It is noted that the most rational way of introducing computers into medical establishments consists in the development of local computer network (LCN). An optimal variant of multicomputer association is represented by LCN based on star topology having a multidrop line as a shunt. Such a solution has some distinct advantages since in this case a multidrop line can operate both as an autonomous mini-LCN and together with other multidrop lines. Besides, heterogenic computers can be grouped into similar multidrop lines.