Early chronology of heat stress-induced alterations in skeletal muscle

Prolonged exposure to elevated environmental temperature can result in heat stress. Heat stress has negative effects on human health, animal health and wellbeing, and brings economic losses related to agricultural production. While clinical symptoms of heat stress are well studied, intracellular mechanisms of heat stress-induced injury require further investigation and are essential for development of etiological treatment of heal illness. Skeletal muscle dysfunction is one of the major pathologies associated with heat stress in both humans and animals. This thesis was aimed to determine changes in major pathways involved in the skeletal muscle response to short-term hyperthermic exposure. It has been established that redox balance plays a crucial role in heat stress injury as an exposure to elevated temperature leads to mitochondrial respiratory dysfunction via disruption of the mitochondrial electron transport chain. Dysfunctional mitochondrial respiration, in turn, leads to increased production of reactive oxygen species and oxidative stress. Further, heat stress activates inflammatory signaling pathways in skeletal muscle. To determine changes in heat stress sensitive pathways, this thesis was divided into three research chapters. The first research chapter includes results from pigs exposed to heat stress for 2 h, 4 h, or 6 h. We found that heat stress resulted in decreased abundance of oxidative stress indicators likely due to elevations in antioxidant activity. These changes were independent of mitochondrial content and mitochondrial biogenesis. In the second research chapter we found activation of AP-1 signaling pathway following 4 h of heat stress, while initial signs of NF-κB activation occurred following 6 h of heat stress. Inflammatory signaling activation was associated with decreased protein abundance of cytokine IL-6. In the final research chapter we aimed to determine the extent to which short-term heat stress altered mitochondrial function and confirm a reductive shift in redox balance in murine skeletal muscle. Mice exposed to elevated temperature for 6 h had mitochondrial function similar to animals kept under thermoneutral conditions. In conclusion, short-term heat stress shifts redox balance and activates inflammatory signaling but has little effect on mitochondrial content, biogenesis, or function

Current State of Heterotrophic Bacterioplankton and Bacteriobenthos in the Northern and Middle Parts of the Caspian Sea

Data on the abundance of heterotrophic bacterioplankton and bacteriobenthos in the northern and middle parts of the Caspian during the period from 2013 to 2017 are presented. In the waters of the northern part of the Caspian, a peak in the number of saprotrophs and crude oil degraders was recorded in 2013. In the middle part of the Caspian and in the region of the Mangyshlak regression, high numbers of heterotrophic bacteria were recorded in 2013 and 2016. The biodiversity of bacterioplankton in the surveyed areas is almost the same; the species composition of saprotrophs and crude oil degraders is identical. In the bottom sediments of the northern and middle parts of the Caspian Sea, two peaks of saprotrophic bacteriobenthos development (in 2013 and 2016) were recorded; in the region of the Mangyshlak threshold, the concentration of saprotrophs remained stable. The number of crude oil degraders was inferior to those of saprotrophs, while the proportion of crude oil degraders to saprotrophs changed annually. The species composition of saprotrophs is relatively stable, the biodiversity of oil-oxidizing bacteriobenthos has changed in the direction of increasing the proportion of non-fermenting bacteria. Constant changes in the ratio of the number of saprotrophs and crude oil degraders, together with the transformations of the dominant groups of the species composition of bacteria, indicated the instability of bacteriobenthos, and, as a result, the vulnerability of the microecosystem of bottom sediments under changing environmental conditions

Situational Communication in Teaching Russian as a Foreign Language to Beginner Learners

The paper presents the results of a study that explores the real teaching experience designing different kinds of speech situations during lessons of Russian as a Foreign Language for beginner learners. The study was carried out at National Research Tomsk Polytechnic University in the 2014-2015 academic year. The primary concern was to discover the most productive set of expressions and speaking turns for situational communication. The outcome is an algorithm of designing speech situations and a typology of speech situations. The paper may be of interest to practising teachers of Russian as a foreign language, students from teacher training colleges and to anyone who is interested in the methodology of teaching Russian as a foreign language

Flt3L-Mediated expansion of plasmacytoid dendritic cells suppresses HIV infection in humanized mice

Plasmacytoid dendritic cells (plasmacytoid DC, pDC) are major IFN-I producers and have been shown to be affected by HIV through ill-defined mechanisms. In this study, we directly assess the role of pDC in early infection, evaluating whether modulating their abundance can alter viral replication. First, HIV infection of humanized mice induces systemic depletion of pDC, and in the presence of soluble FMS-like tyrosine kinase 3 ligand (Flt3L), pDC levels remain elevated. Flt3L significantly delays the onset of viremia and reduces viral replication via a process that is dependent on pDC and mediated through an enhanced early IFN-I response. pDC from Flt3L-treated mice are more prone to express IFN-a following TLR7 stimulation, but this propensity is gradually decreased during infection. In conclusion, maintaining pDC levels and function is key to effective early viral control, and in this context, these findings provide practical insights for anti-HIV strategies and vaccine design

Early chronology of heat stress-induced alterations in skeletal muscle

Prolonged exposure to elevated environmental temperature can result in heat stress. Heat stress has negative effects on human health, animal health and wellbeing, and brings economic losses related to agricultural production. While clinical symptoms of heat stress are well studied, intracellular mechanisms of heat stress-induced injury require further investigation and are essential for development of etiological treatment of heal illness. Skeletal muscle dysfunction is one of the major pathologies associated with heat stress in both humans and animals. This thesis was aimed to determine changes in major pathways involved in the skeletal muscle response to short-term hyperthermic exposure. It has been established that redox balance plays a crucial role in heat stress injury as an exposure to elevated temperature leads to mitochondrial respiratory dysfunction via disruption of the mitochondrial electron transport chain. Dysfunctional mitochondrial respiration, in turn, leads to increased production of reactive oxygen species and oxidative stress. Further, heat stress activates inflammatory signaling pathways in skeletal muscle. To determine changes in heat stress sensitive pathways, this thesis was divided into three research chapters. The first research chapter includes results from pigs exposed to heat stress for 2 h, 4 h, or 6 h. We found that heat stress resulted in decreased abundance of oxidative stress indicators likely due to elevations in antioxidant activity. These changes were independent of mitochondrial content and mitochondrial biogenesis. In the second research chapter we found activation of AP-1 signaling pathway following 4 h of heat stress, while initial signs of NF-κB activation occurred following 6 h of heat stress. Inflammatory signaling activation was associated with decreased protein abundance of cytokine IL-6. In the final research chapter we aimed to determine the extent to which short-term heat stress altered mitochondrial function and confirm a reductive shift in redox balance in murine skeletal muscle. Mice exposed to elevated temperature for 6 h had mitochondrial function similar to animals kept under thermoneutral conditions. In conclusion, short-term heat stress shifts redox balance and activates inflammatory signaling but has little effect on mitochondrial content, biogenesis, or function.</p

Dynamics of physicochemical indicators using various fertilization systems on sod-podzolic sandy loam soil and their Influence on Crop Productivity

As a result of the studies carried out by the Department of Chemistry, Agrochemistry and Agroecology to improve the physicochemical parameters of sod-podzolic soils in the conditions of the Pskov region, positive results were obtained. It was noted that on the sod-podzolic sandy loam soil in the period from 2016 to 2019, in the control option, there was a gradual increase in soil acidity over the years. For 5 years, the exchange acidity increased by 0.1 units, and the hydrolytic acidity of the soil by 0.07 meq/100 g of soil. Against the background with mineral fertilizers, as well as in the control, during the study period there was no decrease in the value of exchangeable acidity, and the increase in hydrolytic acidity was not significant by 0.02 meq/100 g of soil, respectively, in relation to 2016. Application of manure in the amount of 30 and 40 t/ha contributed to a significant improvement in the acid-base state of the soil. During the years under study, exchangeable acidity decreased by 0.7-1.1 units (from 5.8 to 6.1 units), and the hydrolytic acidity of the soil decreased by 0.08 meq/100 g of soil due to the influx of stubble-root residues. Application of manure reduced the negative indicators of the Ca and Mg balance by 564 kg/ha or by 83 %, and in the organomineral and mineral options only by 64 and 39 %, respectively. The results of studies on sandy loamy sod-podzolic soil also showed a high efficiency of the influence of fertilization systems on the productivity of crops in the crop rotation link. The best performance indicators were obtained from the organomineral fertilization system

The Effective Earth Faults Distance Protection Algorithm for Tapped Lines

One of the main problems with distance protection of tapped lines is related to zero sequence infeed from an earthed tap-transformer. For the solution of this problem the distance measuring units algorithms for the tapped lines are developed. The new earth-faults distance protection algorithms are based on the use of numerical optimization methods and the objective function adaptation of to the network configurations. The estimations of new and classical algorithms operation in different earth fault conditions at the end of first protective zone are obtained. It is shown that the effectiveness of the developed earth-fault distance protection algorithms operation during different fault conditions on the tapped lines are higher then effectiveness of the classic algorithms