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The paper presents the results of studying light curves of the star HD 168443 obtained from the ground-based and space photometric observations within the ASAS, KWS surveys, and the Hipparcos mission from 1990 to 2020. During 30 years of observations, the average annual brightness of the star remained constant within the measurement errors, the mean V -value was 6 m .96. Using the dense data series in 2007–2009, the photometric period of 34.7 days was found, and the low-amplitude brightness variability was studied with this period. We determined epochs and amplitude of rotational modulation produced by the development of active regions. These parameters do not change during 2–5 rotations of the star. The amplitude of the rotational modulation increases in 2007 before the epoch of maximum brightness. The star was the brightest in 2009, its V -magnitude was 6 m .92. The location of starspots on the surface of the star during these epochs is also considered.

Exposure to stress activates the hypothalamic–pituitary–adrenal axis and leads to increased levels of glucocorticoid (GC) hormones. Prolonged elevation of GC levels causes neuronal dysfunction, decreases the density of synapses, and impairs neuronal plasticity. Decreased sensitivity to glucocorticoids (glucocorticoid resistance) that develops as a result of chronic stress is one of the characteristic features of stress-induced psychopathologies. In this article, we reviewed the published data on proposed molecular mechanisms that contribute to the development of glucocorticoid resistance in brain, including changes in the expression of the glucocorticoid receptor (GR) gene, biosynthesis of GR isoforms, and GR posttranslational modifications. We also present data on alterations in the expression of the FKBP5 gene encoding the main component of cell ultra-short negative feedback loop of GC signaling regulation. Recent discoveries on stressand GRinduced changes in epigenetic modification patterns as well as normalizing action of antidepressants are discussed. GR and FKBP5 gene polymorphisms associated with stress-induced psychopathologies are described, and their role in glucocorticoid resistance is discussed.

Based on the available photometric data for the star V647 Her, including those obtained from photographic archives, we considered the yearly-mean brightness variability over the time interval 1939–2022. The dense data series obtained in 2019 and 2022 at CrAO as well as the sample for 2004 from the SuperWASP catalog showed changes in light curves and in color indices of the star with a period of 20.69 days. Changes in the V–I color index indicate the presence of cool spots on its surface. The parameters of starspots were calculated within the zonal model for each year and it was found that the temperature of the spots is 500–600 K lower than the temperature of the quiet photosphere with T eff = 3300 K, the spots occupy from 8 to 30% of the entire surface of the star in different years. The spottedness of the star’s photosphere is an indicator of its activity, and according to the interval between the epochs of minimum spottedness, we derived a characteristic time between the minima in activity of V647 Her of about 60 years, and the duration of the maximum of activity of about 5 years.

An analysis of photometric observations of the star V647 Her (M3.5V) obtained at the 1.25-m telescope of the Crimean Astrophysical Observatory in 2022 is presented. The presence of a low-amplitude variability in brightness of the star with a period of 20.69 d, found from observations in 2019 was confirmed. It is shown that as the brightness decreases, the star becomes redder. The observed kind of photometric variability is due to the presence of cool spots on the surface of the star and rotational modulation of brightness with a full amplitude of no more than 0 05. We perform a comparison of the photometric results obtained in 2019, 2022, and 2004. The locations of starspots at different epochs were determined from the analysis of phase curves. The distribution of starspots has been maintained for 40–100 days. Starspot parameters were estimated in the framework of the zonal model. The temperature of starspots is 2700–2800 K. The area they occupied in 2004 is 15% of the total surface area of the star. According to the 2019 and 2022 data, it increases up to 30%. The seasonal redistribution of starspots leads to the difference between the spottedness of hemispheres, which is less than 2%.

The International Geomagnetic Reference Field (IGRF) model is a combination of the several models developed by independent groups of scientists using different approaches for the selection of input data and methods for calculating harmonic coefficients. This approach allows for mutual comparison of individual models and for their combination to obtain the most reliable values of the harmonic coefficients. This letter provides a brief description of methods for building the IZMIRAN Earth’s main magnetic field model, submitted to the IAGA Working Group V-MOD for creating IGRF-13. Special efforts were made to obtain as uniform coverage of the entire Earth’s surface as possible with observations. The surface was divided into a grid of approximately equal cells. Then the data for geomagnetically quiet intervals were placed in the corresponding cells and a median filter was applied to select the data in each cell. Spherical harmonic coefficients up to degree 13 were calculated for the interval 2014-Jan to 2019-Aug with a time step of 10 days and extrapolated to 01.01.2010.

We consider a class of strictly pseudohyperbolic equations with lower order terms. The solvability of the Cauchy problem in Sobolev spaces with special weights is established. The uniqueness of the solution is proven and estimates are obtained.

Photometric data covering 1994–2009, obtained at the Crimean Astrophysical Observatory or retrieved from the ASAS and SuperWASP catalogs, were used to analyze the brightness variations of the rapidly rotating star V833 Tau, whose activity level is close to saturation. Combined with previously published results, these data represent for the first time all stages in the development of the star’s 19- year activity cycle. The photometric period and rotational-modulation amplitude for different epochs are determined, and the qualitative pattern of the spots is considered. The photometric period is close to the orbital period, but always exceeds it, indicating that surface inhomogeneities are located far from the equatorial plane. With the high spottedness of the star, reaching 28% at the cycle maximum, the rotationalmodulation amplitude is 0.05−0.1 m , and increases during the growth and decline phases of the 19-year cycle. The rotational modulation is due to spots with higher latitudes than in the case of the Sun, and concentrating on active longitudes.

We report here studies of the behavior of male mice of the inbred strain C57BL/6 after prolonged exposure to two factors – social stress and infections with Opisthorchis, a combination which is often seen in humans. Mice of four groups were compared: 1) mice with prolonged experience of defeat in intermale confrontations (30 days) (SS); 2) those infected with O. felineus helminths (six months) (OF); 3) animals subjected to both factors (SS + OF); and 4) mice experiencing neither factor (CON). The behavior of all animals was evaluated in an open field test including a box, which was empty for the first 3 min of the test and contained an unfamiliar male of the inbred strain BALB/c during the second 3 min. Social stress had a stronger influence on the behavioral parameters evaluated in this test than infection. SS mice were more active than all others in exploring the box containing an unfamiliar male: they climbed onto it much more frequently and had longer mean durations of time spent close to the box. In addition, during the first 3 min of the test, these animals displayed elevated exploratory activity (number of rearings by the wall), and greater numbers and durations of grooming episodes. Infected mice of the OF group showed no difference in behavior from the CON group in either the first 3 min or the second 3 min of the test. In mice with the combination of factors (SS + OF), nonsocial forms of behavior were also no different from those in controls and reactions to the unfamiliar male were weaker than in SS mice. These data lead to the conclusions that prolonged experience of defeats in intermale confrontations had a stronger influence on social and nonsocial behavior in mice than chronic infection of the animals with O. felineus helminths and that the combination of these factors reduces social interest in mice.

Photoelectric B -band data and calibrated photographic estimates are used to plot a combined light curve of the red dwarf V833 Tau (dK5e) covering 1899–2009. A frequency analysis was applied to the resulting series of yearly mean B magnitudes, yielding possible photospheric activity cycles acting on various timescales. The high-amplitude variations, up to 0.6 m (0.8), follow a cycle with a duration of 78.25 yrs. A 18.8-year cycle with an amplitude of 0.39 m –0.16 m was also detected, and changes of its characteristics for each observing epoch considered. The star becomes redder at epochs of decreased brightness, suggesting that the 18-year cycle is related to spot-formation processes. The existence of the shorter 6.4-year and 2.5-year cycles reported earlier is confirmed.

Purpose. Establishing the dependencies of rational parameters of turbocompressor contact air coolers on the operating mode and initial conditions. Methodology. The methods of analytical research, mathematical modeling, physical modeling, and mathematical statistics were used in the study. Findings. As a result of the research, an optimization mathematical model of the mine turbocompressor air cooler was developed, which allows establishing its rational parameters depending on the initial conditions and operating modes of the turbocompressor. The adequacy of the theoretical studies was proved on a specially designed experimental setup. The obtained dependences make it possible to minimize the theoretical flow rate at the inlet to the uncooled section of the turbocompressor, which reduces the specific energy consumption for the compressed air production. Originality. For the the first time, a method has been developed for determining the rational parameters of contact air coolers when the initial temperature of water, air, and air pressure changes, which allows developing a methodology for the constructive calculation of the contact cooling system of mine turbocompressors. Practical value. Compressed air is widely used in all industries. It is one of the most common energy carriers in industrial enterprises, and the devices associated with its distribution and processing are an energy-intensive complex industrial energy system; the level of its perfection depends on the performance of technological processes that use compressed air. Compressed air is widely used in the mining industry (ore mining and fuel production). Compressed air is produced by turbocompressors. To increase the efficiency of the compressor, compressed air coolers are used. A significant weakness of the standard compressor cooling system is the rapid contamination of the heat exchange surfaces of air coolers with scale layers, which leads to a decrease in their efficiency and an increase in the specific energy consumption for compressed air production. This disadvantage is not found in the Venturi tube – centered droplet separator contact air coolers. As a result of the study, the dependencies were obtained and used to develop a methodology for the constructive calculation of contact air coolers for a mine turbocompressor.