[Time perspective, sleep and wellbeing of the elderly during COVID-19 pandemic.]

The purpose of this study was to analyze the association between the time perspective and the psychophysiological state of the elderly during the pandemic COVID-19. 433 residents from 11 Russian cities aged 60,8±9,8 years (range - 50-94 years, women - 78,7%) took part in the study. During the online survey, each participant of the study provided personal data (place of residence, sex, age, height, and weight) and completed the Zimbardo Time Perspective Inventory, the Munich Chronotype Questionnaire, the Beck Depression Inventory and the Yale Food Addiction Scale. It was found that elderly people with a balanced time perspective had the lowest level of depression during the pandemic COVID-19 and less expressed sleep inertia at work days, while those with a past negative time perspective had the highest level of depression, high frequency of detection of food addiction and low sleep efficiency. The other types of time perspective (past positive, present hedonistic, present fatalistic and future) had intermediate values of indicators between these two extreme options. Thus, the conducted studies have shown that elderly people with a balanced time perspective showed the highest level of resistance to psychoemotional stress caused by the pandemic COVID-19.

Association of chronotype and social jetlag with human non-verbal intelligence.

The aim of this study was to evaluate the effects of chronotype and social jetlag (SJL) on intelligence. Subjects were aged 14-25 years (n = 1008). A significant effect of intelligence on academic performance, as measured by the Raven's Standard Progressive Matrices test, was found (F2,917 = 11.75, P < 0.0001, η2 = 0.03). When SJL was less than 2 hours, the intelligence of people with late chronotype was found to be higher than that of subjects with early and intermediate chronotypes (F2,305 = 3.12, P < 0.05, η2 = 0.02). A negative effect of SJL on the results of intelligence testing was noted only in subjects with late chronotype (F2,536 = 2.61, P < 0.05, η2 = 0.02). Our data suggest that people with late chronotype have a higher level of intelligence, but these advantages disappear when SJL ≥2 hours.

[Dynamics of rumenoenteral transport of progesterone in sheep in chronic experiment].

In chronic experiments on pregnant and lactating sheeps with large fistula of rumen the dynamics of progesterone transport in a cavity of temporarily isolated reticulo-rumen depending on a physiological condition of animals, composition of solution filling a cavity of organ, and time of incubation, were studied. On three animals, 24 experiments were carried out. It was established that, during pregnancy, in a cavity of reticulo-rumen more progesterone was transported than during lactation (p < 0.05). Addition of lignin and cellulose to the salt solution increased the progesterone transport in the cavity of reticulo-rumen (p < 0.001). During three-hour incubation of salt solution in the cavity of reticulo-rumen, an increase of progesterone transport was observed in cavity of the organ (p < 0.001). The data obtained confirm the assumption that forestomach of ruminants participates in removing of progesterone from internal environment to enteral one and that carbohydrate polymers facilitate this process.

[Antioxidant status of ewe's blood during pregnancy and lactation].

Antioxidant status of ewe's blood during pregnancy and lactation was studied. It is revealed that the lipid peroxidation in erythrocytes is decreased, whereas in blood plasma is increased in the middle pregnancy, reaching the maximum shortly before peak of progesterone production. The activities of antioxidant enzymes are increased at the end of pregnancy, when the level of progesterone in blood is maximal. The positive correlation between plasma progesterone level and activity of erythrocyte superoxide dismutase (p < 0.01), between plasma cortisol concentration and total antioxidant capacity of blood plasma (p < 0.05) are revealed. It is shown, that the activities of antioxidant enzymes reach a maximum in the critical periods of pregnancy, providing the protection of the maternal organism and the fetus against negative influence of free radicals. The positive correlation between a level of hormones and separate parameters of antioxidant system in blood allows to assume, that progesterone participates in the regulation of enzymatic part of the antioxidant system, while cortisol is implicated in the regulation of the non-enzymatic component of this system in ewes.