The Functional States of the Participants of a Marine Arctic Expedition with Different Levels of Vitamin D in Blood.

(1) Background: The vitamin D level in blood is one of the markers of the functional reserves of the human body and can contribute to more successful adaptation in the Arctic. (2) Methods: The study involved 38 participants in the project "Arctic Floating University-2021". The determination of vitamin D content was carried out at the beginning of the expedition. A dynamic study was carried out for 20 days in the morning and in the evening. The functional state parameters of the participants were assessed using psychophysiological and questionnaire methods. Statistical methods: Mann-Whitney U-test and correlation analysis. (3) Results: It was found that at the beginning of the expedition, the functional state of participants with more severe vitamin D deficiency is characterized by a shorter average duration of RR intervals (p = 0.050) and reduced SDNN values (p = 0.015). The higher the content of vitamin D, the greater increase in speed (r = 0.510), the higher the increase in projective performance (r = 0.485), and the smaller the increase in projective stress (r = -0.334). Significant relationships between the subjective characteristics of functional states and the vitamin D of participants have not been established. (4) Conclusion: With an increase in the severity of vitamin D deficiency in the blood, the adaptive capabilities of participants decrease during an expedition to the Arctic.

Enhanced Non-Associative Long-Term Potentiation in Immature Granule Cells in the Dentate Gyrus of Adult Rats.

The dentate gyrus is one of the few sites of neurogenesis in the adult brain. Integration of new-generated granule cells into the hippocampal circuitry provides a substrate for structural plasticity, fundamental for normal function of adult hippocampus. However, mechanisms of synaptic plasticity that mediate integration of new-generated granule cells into the existing circuitry remain poorly understood. Especially mechanisms of plasticity at GABA-ergic synapses remain elusive. Here, we show that postsynaptic spiking without presynaptic activation can induce heterosynaptic, non-associative plasticity at GABA-ergic inputs to both immature and mature granule cells. In both immature and mature neurons, plastic changes were bidirectional and individual inputs could express long-term potentiation (LTP) or long-term depression (LTD), or do not change. However, properties of non-associative plasticity dramatically change with maturation of newly generated granule cells: while in immature cells there was a clear predominance of non-associative LTP and net potentiation across the inputs, in mature neurons, potentiation and depression were balanced with no net change on average. We conclude that GABA-ergic inputs to granule cells are plastic, and that the rules for induction of non-associative plasticity change with maturation. We propose that potentiation-biased non-associative plasticity of GABA-ergic transmission might help to counter-balance an increase of excitatory drive that is facilitated by enhanced LTP at glutamatergic synapses in maturating granule cells. Such mechanism might help to build a strong GABA-ergic input to surviving active new cells, necessary for normal function of mature granule cells, which operate under a tight inhibitory control and generate sparse spiking activity.

Job Stress and Working Capacity among Fly-In-Fly-Out Workers in the Oil and Gas Extraction Industries in the Arctic.

(1) Background: the research purpose is to identify and describe the stress and working capacity dynamics of oil and gas fly-in-fly-out (FIFO) workers in the Arctic during the fly-in period using biochemical, psychophysiological and psychological methods with further analysis of the relationship between them using objective, subjective and projective indicators. (2) Methods: The research involved 70 oil and gas FIFO specialists in the Arctic. The study of stress and working capacity was carried out using biochemical (saliva analysis for cortisol), psychophysiological (complex visual-motor reaction and variational cardiointervalometry) and psychological (questionnaire "Well-being. Activity. Mood", M. Luscher's color test and the subjective control level methods. (3) Results: There is a similarity in the dynamic curves of oil and gas FIFO employees' stress and working objective, subjective and projective indicators during the fly-in period. The maximum relationships number was obtained between objective cortisol indicators in saliva (stress), complex visual-motor response indicators (operator working capacity), variational cardiointervalometry (functionality level), and interpretation coefficients (working capacity, stress, vegetative balance) according to M. Luscher's test. (4) Conclusions: The obtained results made it possible to explain the mechanisms underlying the previously developed FIFO workers' adaptation strategies classification, in which emergency and economic adaptation strategies were identified.

Analysis of Psychological Risks in the Professional Activities of Oil and Gas Workers in the Far North of the Russian Federation.

The professional activity in shifts in the Arctic contributes to the development of unfavorable functional status and destructive personal qualities of workers, which leads to a decrease in the level of mental health and efficiency of labor activity. The reference to the risk-oriented approach is conditioned by the need to predict the professional efficiency of shift personnel. The purpose of this study is to determine the psychological risks of oil and gas workers with a shift work organization in the Arctic. The study involved 70 oil and gas workers. The research methods were used as follows: documentation study, work process monitoring, questionnaire survey, psychophysiological and psychological testing, and statistical analysis methods: descriptive statistics-conjugacy tables with calculation of Pearson's criterion, two-stage cluster, dispersion, and discriminant analyzes. As a result of this research, it was established that oil and gas workers characterized by different combinations of character accentuations would have different psychological risks, and, consequently, different approaches to their psychological support are needed.