Mancha3D Code: Multipurpose Advanced Nonideal MHD Code for High-Resolution Simulations in Astrophysics.

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).

The influence of thermal pressure gradients and ionization (im)balance on the ambipolar diffusion and charge-neutral drifts.

Solar partially ionized plasma is frequently modelled using single-fluid (1F) or two-fluid (2F) approaches. In the 1F case, charge-neutral interactions are often described through ambipolar diffusion, while the 2F model fully considers charge-neutral drifts. Here, we expand the definition of the ambipolar diffusion coefficient to include inelastic collisions (ion/rec) in two cases: a VAL3C one-dimensional model and a 2F simulation of the Rayleigh-Taylor instability (RTI) in a solar prominence thread based on [Lukin et al. 2024 Phil. Trans. R. Soc. A 382, 20230417. (doi:10.1098/rsta.2023.0417)]. On one side, we evaluate the relative importance of the inelastic contribution, compared to elastic and charge-exchange collisions. On the other side, we compare the contributions of ion/rec, thermal pressure, viscosity and magnetic forces to the charge-neutral drift velocity of the turbulent flow of the RTI. Our analysis reveals that the contribution of inelastic collisions to the ambipolar diffusion coefficient is negligible across the chromosphere, allowing the classical definition of this coefficient to be safely used in 1F modelling. However, in the transition region, the contribution of inelastic collisions can become as significant as that of elastic collisions. Furthermore, we ascertain that the thermal pressure force predominantly influences the charge-neutral drifts in the RTI model, surpassing the impact of the magnetic force. This article is part of the theme issue 'Partially ionized plasma of the solar atmosphere: recent advances and future pathways'.

Acoustic-gravity wave propagation characteristics in three-dimensional radiation hydrodynamic simulations of the solar atmosphere.

There has been tremendous progress in the degree of realism of three-dimensional radiation magneto-hydrodynamic simulations of the solar atmosphere in the past decades. Four of the most frequently used numerical codes are Bifrost, CO5BOLD, MANCHA3D and MURaM. Here we test and compare the wave propagation characteristics in model runs from these four codes by measuring the dispersion relation of acoustic-gravity waves at various heights. We find considerable differences between the various models. The height dependence of wave power, in particular of high-frequency waves, varies by up to two orders of magnitude between the models, and the phase difference spectra of several models show unexpected features, including ±180° phase jumps. This article is part of the Theo Murphy meeting issue 'High-resolution wave dynamics in the lower solar atmosphere'.

Influence of ambipolar and Hall effects on vorticity in three-dimensional simulations of magneto-convection.

This paper presents the results of the analysis of three-dimensional simulations of solar magneto-convection that include the joint action of the ambipolar diffusion and the Hall effect. Three simulation runs are compared: one including both ambipolar diffusion and the Hall effect; one including only ambipolar diffusion and one without any of these two effects. The magnetic field is amplified from initial field to saturation level by the action of turbulent local dynamo. In each of these cases, we study 2 h of simulated solar time after the local dynamo reaches the saturation regime. We analyse the power spectra of vorticity, of magnetic field fluctuations and of the different components of the magnetic Poynting flux responsible for the transport of vertical or horizontal perturbations. Our preliminary results show that the ambipolar diffusion produces a strong reduction of vorticity in the upper chromospheric layers and that it dissipates the vortical perturbations converting them into thermal energy. The Hall effect acts in the opposite way, strongly enhancing the vorticity. When the Hall effect is included, the magnetic field in the simulations becomes, on average, more vertical and long-lived flux tube-like structures are produced. We trace a single magnetic structure to study its evolution pattern and the magnetic field intensification, and their possible relation to the Hall effect. This article is part of the Theo Murphy meeting issue 'High-resolution wave dynamics in the lower solar atmosphere'.

[Strategy of sinus rhythm restoration after single stage correction of mitral valve defect and maze procedure for improvement of efficacy and safety of anticoagulant therapy].

We analyzed clinical efficacy of a strategy of sinus rhythm (SR) restoration after single stage correction of mitral valve defect and failed radiofrequency maze procedure elaborated and realized in the Research Institute for Complex Issues of Cardiovascular Diseases, and assessed its value for increase of efficacy and safety of anticoagulant therapy. First stage of this strategy--cardiosurgical treatment with maze procedure--resulted in restoration of SR in 61.8% of cases. In case of persistence of tachyarrhythmia external elelectro-impulse therapy was used in 1-1.5 months after cardiac surgery as a second stage of our strategy. Third stage--catheter radiofrequency ablation--was applied to patients with implanted biological cardiac valves. Second and third stages facilitated restoration of SR in 84.8 and 93.2% of patients, respectively, and provided 100% SR restoration in patients with biological valve prostheses. The suggested strategy allowed to withdraw anticoagulant therapy in patients with biological valves and to reduce level of hypocoagulation to lower limit of target range in patients with mechanical prostheses.

Dislocations in magnetohydrodynamic waves in a stellar atmosphere.

We describe the presence of wave front dislocations in magnetohydrodynamic waves in stratified stellar atmospheres. Scalar dislocations such as edges and vortices can appear in Alfvén waves, as well as in general magnetoacoustic waves. We detect those dislocations in observations of magnetohydrodynamic waves in sunspots in the solar chromosphere. Through the measured charge of all the dislocations observed, we can give for the first time estimates of the modal contribution in the waves propagating along magnetic fields in solar sunspots.

Vortex Motions in the Solar Atmosphere: Definitions, Theory, Observations, and Modelling.

Vortex flows, related to solar convective turbulent dynamics at granular scales and their interplay with magnetic fields within intergranular lanes, occur abundantly on the solar surface and in the atmosphere above. Their presence is revealed in high-resolution and high-cadence solar observations from the ground and from space and with state-of-the-art magnetoconvection simulations. Vortical flows exhibit complex characteristics and dynamics, excite a wide range of different waves, and couple different layers of the solar atmosphere, which facilitates the channeling and transfer of mass, momentum and energy from the solar surface up to the low corona. Here we provide a comprehensive review of documented research and new developments in theory, observations, and modelling of vortices over the past couple of decades after their observational discovery, including recent observations in H α , innovative detection techniques, diverse hydrostatic modelling of waves and forefront magnetohydrodynamic simulations incorporating effects of a non-ideal plasma. It is the first systematic overview of solar vortex flows at granular scales, a field with a plethora of names for phenomena that exhibit similarities and differences and often interconnect and rely on the same physics. With the advent of the 4-m Daniel K. Inouye Solar Telescope and the forthcoming European Solar Telescope, the ongoing Solar Orbiter mission, and the development of cutting-edge simulations, this review timely addresses the state-of-the-art on vortex flows and outlines both theoretical and observational future research directions.

[Effect of biopreparations on dynamics of the number of bacteria and phytopathogenic fungi in potato agroecosystem].

Application of biological preparations such as Phytotsid and Planryz favoures the growth of the general number of soil's bacteria population compared with control by 13.0-36.1% in the variant of potato variety Scarbnytsya and by 4.5-24.6% of potato variety Oberig. It also decreases 1.2-1.8 times the number of soil phytopathogens--Fusarium and Alternaria. During the application of Rovral Akvaflo the Shenon's ecological index of species biodiversity was lower than during the bioprepation application. One could observe a decrease of species biodiversity and dominance of dark pigmentation in fungi--Alternaria sp., Cladosporium sp., Phoma sp., Doratomyces sp., and pigmented bacteria.

[Seasonality of Sonne dysentery among organized and unorganized groups of children in years with different morbidity levels]. / Sezonnost' dizenterii Zonne sredi organizovannykh i neorganizovannykh detei v gody s raznymi urovniami zabolevaemosti.

Differences in the monthly distribution of morbidity in Sonne dysentery among children of preschool age in children's institutions and among those not attending such institutions have been revealed. In years characterized by a high morbidity level, the epidemic process develops simultaneously among all children with some prevalence in its activity being observed from January to August among children not attending children's institutions and from September to December among institutionalized children. In years characterized by a low morbidity level, the rise of morbidity among children aged up to 3 years, both seasonal and not connected with the season (in January), is determined by the rise of morbidity among those children who attend children's institutions, while among noninstitutionalized children aged 4-6 years the seasonal rise of morbidity begins and becomes manifest earlier.

[Ethanol stimulates the RNA-polymerase activity of rat liver cell nuclei]. / Etanol stimuliruet aktivnost' RNK-polimeraz iader kletok pecheni krys.

The variation dynamic of the activity of RNA-polymerase fractions II and I + III (EC 2.7.7.6) has been studied after single and long-term ethanol administration. The acute alcoholization of animals caused early stimulation of RNA-polymerase II. Activity of this enzyme remains higher even 24 hours after the ethanol administration. The activity of RNA-polymerase I + III is induced later, however, a day later it does not differ from the control. The effect of chronic ethanol intoxication is characterized by stimulation of all classes of RNA-polymerases half an hour after ethanol cessation and has a stable action. The repeated ethanol injections, compared with the first ethanol administration, induce shorter and less pronounced stimulation of RNA-polymerases against a background of the increased level of the enzymic activity. The comparison of the obtained results and data available in literature supposes that variation of the transcription processes plays an important role in the pathogenesis of the ethanol intoxication.

[Effect of ethanol on the synthesis of chromatin proteins of the nuclei of rat liver cells]. / Vliianie étanola na sintez khromatinovykh belkov iader kletok pecheni krys.

The synthesis of nuclear chromatin proteins of rat liver cells was studied after a momentary and chronic administration of ethanol (3 g/kg). The 14C-acetaldehyde penetration to the nuclei and its binding to chromatin protein components were also studied. The momentary administration of ethanol inhibits the synthesis of histons and reenhances the incorporation of radioactive precursors into DNA labile-bound nonhiston proteins. The reduced level of the synthesis of all the studied chromatin proteins was observed after the chronic administration of ethanol.

[Comparison of ethanol and acetaldehyde interactions with chromatin components of cell nuclei from the rat liver]. / Sravnenie vzaimodeistviia étanola i atsetal'degida s komponentami khromatina iader kletok pecheni krys.

Interaction of ethanol and acetaldehyde with structures of rat liver cells nuclei was studied in vivo and in vitro using labelled compounds. After injection of 14C-ethanol and 14C-acetaldehyde into control and alcohol-consuming animals the radioactivity was found in carioplasm, non-histone proteins and residual DNA-protein complex. Relative value of specific radioactivity of all the chromatin components studied was practically similar after administration of either ethanol or acetaldehyde. The effect of such aldehyde dehydrogenase inhibitor as teturam led to a significant increase of the label incorporation into chromatin proteins. Acetaldehyde was shown to bind intensively with the isolated chromatin matrix. At the same time, radioactivity was not found in chromatin after incubation with labelled ethanol. The data obtained suggest that alterations in structure and functions of genetic cell apparatus under conditions of ethanol intoxication occurred mainly due to the action of acetaldehyde as a result of ethanol reduction.

[Study of visualization quality characteristics for digital X-ray fluorographic complexes]. / Issledovanie kharakteristik kachestva sredstv vizualizatsii dlia tsifrovykh rentgenofliuorograficheskikh kompleksov.

The paper presents a comparative assessment of the quality characteristics of computers available at the market for X-ray image visualization by using by the generally accepted criteria and gives recommendations for choosing these means for completing X-ray fluorographic complexes.

[Degree of lipid peroxidation and vitamin E level during the treatment of peptic ulcer]. / Uroven' perekisnogo okisleniia lipidov i kontsentratsiia vitamina E pri lechenii bol'nykh iazvennoi bolezn'iu.

The study of 468 ulcer patients treated by laser irradiation plus choline blocking agents with adjuvant alpha-tocopherol antioxidants (alpha-tocopherol acetate, wild rose and sea-buckthorn oils) provided evidence in favour of the antioxidants addition. Combination of hyperbaric oxygenation (5-6 sessions) or riboxin with choline blocking agents made antioxidants unnecessary. Biochemical findings (vitamin E and malonic dialdehyde concentrations), electron microscopic, ++histo-enzyme and amino acids studies supported the clinical evidence.

SYNTHETIC OBSERVATIONS OF WAVE PROPAGATION IN A SUNSPOT UMBRA.

Spectropolarimetric temporal series from Fe i λ6301.5 Å and Ca ii infrared triplet lines are obtained by applying the Stokes synthesis code NICOLE to a numerical simulation of wave propagation in a sunspot umbra from MANCHA code. The analysis of the phase difference between Doppler velocity and intensity core oscillations of the Fe i λ6301.5 Å line reveals that variations in the intensity are produced by opacity fluctuations rather than intrinsic temperature oscillations, except for frequencies between 5 and 6.5 mHz. On the other hand, the photospheric magnetic field retrieved from the weak field approximation provides the intrinsic magnetic field oscillations associated to wave propagation. Our results suggest that this is due to the low magnetic field gradient of our sunspot model. The Stokes parameters of the chromospheric Ca ii infrared triplet lines show striking variations as shock waves travel through the formation height of the lines, including emission self-reversals in the line core and highly abnormal Stokes V profiles. Magnetic field oscillations inferred from the Ca ii infrared lines using the weak field approximation appear to be related with the magnetic field strength variation between the photosphere and the chromosphere.

[The component composition of the body in children with progressive obesity].

The aim of the investigation was to determine the major components of body mass in obese children. Two hundred and thirty-four children aged 8-16 years, including 181 healthy children and 53 obese children, were examined. The components of body mass in obese children were comparatively analyzed, by taking into account gender, age, and the disease seventy, which Indicated that the adipose tissue was the major component of the body, greatly dominating over muscular and bony components with its increase in progressive disease (up to 280 and 448% of the normal values in second- and third-degree obesity, respectively). The absolute content of fat as the body's major component in overweight children has no great gender differences. In children, obesity progression is accompanied by a statistically significant reduction in absolute body mass and in the proportion of an osseal component in younger age (8-10 years) groups.

[The epidemiological aspects of a study of hereditary nervous system diseases in Amur Province]. / Epidemiologicheskie aspekty izucheniia nasledstvennykh zabolevanii nervnoi sistemy v Amurskoi oblasti.

The prevalence of neurogenetic diseases per 100,000 was studied in Amur Province [correction of Territory]. Charcot-Marie's neural amyotrophy held the lead, Huntington's chorea ranked next. Among the multinational population, the diseases were detected among the Russians, but they were absent in the Evenki. Out of 225 cases, 138 males were afflicted. The most unfavourable factors that predisposed to the disease proved to be infectious processes, toil, and stresses. Epidemiological studies of neurogenetic diseases provide highly valuable information on the migration of abnormal genes and promote to the timely organization of therapeutical and preventive measures.