The paper reports a search for association between the relative bone tissue mass (percent of total body mass, %BT) and FokI (rs10735810), BsmI (rs1544410), and TaqαI (rs731236) vitamin D receptor gene polymorphisms. The group of apparently healthy young adults born in the central and northern regions of European Russia included 61 men and 60 women aged 16–23 years. No statistical association was detected between the FokI polymorphism and %BT. The carriers of the BsmI *A allele exhibited a higher %BT (p = 0.0172) compared to the subjects bearing the BsmI *G*G allele. The subjects with the *C*C TaqαI genotype were characterized by increased %BT compared to the carriers of the *T allele (p = 0.0018). The data are in good correspondence with the results obtained in the studies involving apparently healthy representatives of Central European and Northern European populations of the corresponding age.
We analyzed published data on the serum level of 25-hydroxyvitamin D (25(OH)D in healthy subjects in Russia, Ukraine and Belarus (lat. 45°–65° N). The primary list included 158 publications. Reports with insufficient sample size and incomplete statistical descriptions were excluded from the analysis. The review covers 41 publications comprising 8569 individual assessments. The meta-analysis showed that the average levels of 25(OH)D were the highest among children under the age of 5 years, varied slightly between the age of 6 and 60 years, and decreased in older adults (60+). Gender differences become apparent at the postpuberty stage. The level of 25(OH)D was higher in men. No correlation between the level of 25(OH)D and latitude was found, but the relationship with the season and the duration of daylight was significant. No differences were revealed between ethnic and social groups.
A mathematical model is proposed to analyze the spinal strain-deformation condition resulting from axial and lateral g-loads that are generated by changes in the gravity field and/or pilot’s actions during high-performance aircraft maneuvering under flight overload conditions. An algorithm of solution has been developed, which takes into account changes in the intervertebral disk pressure and the fibrous ring shape at the time when loading reaches close-to-critical g-values. Calculation of the spinal-strain deformation condition was implemented using the SPLEN computer system (KOMMEK, Russia). Analysis of the spinal straindeformation condition was made for two types of external loads: normal load and unilateral load with the bending moment. Maximum permissible loads on the spinal segment were evaluated, and a pattern of distribution of strain intensity and mean strains, spinal deformation, and the destruction field was described. The developed computer models can be used as a basis for developing a technique of predicting characteristic spinal injuries due to different extreme loads and pathologies.
The review considers the roles cortisol (Crt), dehydroepiandrosterone (DHEA), and DHEA sulfate (DHEAS) play in the stress response. Age-related, sexrelated, and circadian fluctuations in normal conditions and in acute or chronic stress are described for Crt, DHEA, and DHEA-S. The main techniques used to estimate the Crt level in the blood, urine, and saliva are described, and approaches to the interpretation of the results discussed. Special attention is paid to Crt assays in anthropological and psychological studies.
The review considers the roles cortisol (Crt), dehydroepiandrosterone (DHEA), and DHEA sulfate (DHEAS) play in the stress response. Age-related, sex-related, and circadian fluctuations in normal conditions and in acute or chronic stress are described for Crt, DHEA, and DHEA-S. The main techniques used to estimate the Crt level in the blood, urine, and saliva are described, and approaches to the interpretation of the results discussed. Special attention is paid to Crt assays in anthropological and psychological studies
The review considers the roles cortisol (Crt), dehydroepiandrosterone (DHEA), and DHEA sul fate (DHEAS) play in the stress response. Agerelated, sexrelated, and circadian fluctuations in normal conditions and in acute or chronic stress are described for Crt, DHEA, and DHEAS. The main techniques used to estimate the Crt level in the blood, urine, and saliva are described, and approaches to the interpretation of the results discussed. Special attention is paid to Crt assays in anthropological and psychological studies.
We describe use of the Monte Carlo modeling method to specify the parameters of near infrared light propagation though the tissues of the head, which is needed for optimizing the operation of brain–computer interfaces. The studies used a four-layer spherical model of the head consisting of skin, bone, gray matter, and white matter. The relationship between the parameters of the radiation recorded and the distance between the source and detector were obtained.
We investigated cognitive functions of attention and decision-making in 18 healthy subjects and 15 schizophrenia patients using an experimental design with consecutive presentation of two short visual stimuli (double-step). In patients with schizophrenia, an increase in the number of errors and change in the pattern of saccadic responses have been found: an increase of the number of two-saccade responses to each stimulus and a decrease in the number of single-saccade responses to the second stimulus. In schizophrenia patients, the latent period of the first of a pair of saccades has been shorter; and the latent period of single saccade has been increased in comparison with healthy subjects. Opposite lateral differences in latent periods of saccades in healthy subjects and schizophrenia patients have been found. Our results show the deficit of cognitive oculomotor control and a decrease in prognostic processes of saccade programming in schizophrenia patients. © 2015, Pleiades Publishing, Inc.
This study is focused on changes in the brain function throughout the adulthood in healthy men and women performing task switching (TS) in the visual modality. One hundred and forty healthy subjects aged 20 to 65 years (69 men) participated in the experiments. In the fMRI study, the subjects performed a test that required switching attention between two objectives (classifying figures according to their form or number). Using the voxel-based morphometry (VBM), we calculated the volumes of gray and white matter in the whole brain and in selected areas. The results showed that a common feature of different age and sex groups performing the TS was bilateral activation of the dorsolateral prefrontal areas, the inferior parietal lobes and the inferior occipital gyrus. We also found a transition from local to diffuse activation occurring with age. In young men (20 to 30 years of age) compared to women, a greater increase in theBOLD signal was found in the prefrontal areas bilaterally, the right parietal lobe and insula, and, in addition, bilateral activation in the supplementary motor area which were not observed in women. Older men and women (51 to 65 years) had no significant differences. The study of the BOLD signal correlations with age in women at the age from 20 to 40 and men from 20 to 55 years showed no significant changes. With further increase of age in both groups we found a consequent increase in the number of brain areas which are activated. The VBM analysis showed a significant decrease in the volume of gray, but not white, matter with age. No significant correlations between age-related changes in the gray matter volume (both in the whole brain and in the specific areas) and BOLD signal in this age group were detected.
The correlations between the serum concentration of 25-hydroxyvitamin D (25(OH)D) and the blood levels of total cholesterol (TC), high-density lipoprotein cholesterol, triglycerides (TG), and apolipoprotein E were analyzed in young non-overweight men (n = 40) and women (n = 61) aged 14–23 years having no acute or active chronic diseases. The measured variables were standardized within sex and four local groups. Spearman rank correlation was observed between the concentration of 25(OH)D and TC in women (Rsp = 0.306, p = 0.017), and between the concentrations of 25(OH)D and TG in men (Rsp = –0.372, p = 0.018).
A method is described for joint use of electroencephalography and near-infrared spectrography to locate sources of electrophysiological and foci of hemodynamic brain activity during motor execution and imagination. The sources of electrophysiological and foci of hemodynamic brain activity most relevant for controlling a hybrid brain-computer interface based on motor imagery are revealed and discussed.
We analyzed published data on the levels of serum 25(OH)D in apparently healthy individuals from the Russian Far North. The total sample included 2061 subjects of various age and ethnic groups. The serum levels of 25(OH)D and its age dynamics in the northerners living in towns are similar to those of the inhabitants of the temperate climate zone of Russia. Data on the age-related changes in the vitamin D status of the indigenous Arctic people with the traditional lifestyle are scanty. Serum 25(OH)D concentrations in the indigenous and alien population of the high-latitude regions reflect the seasonal changes in the daylight duration. The level of vitamin D decreases in winter and reaches minimum in February, i.e., after the end of the polar night. We compared data on rural Russian and indigenous people and found ethnic differences in the 25(OH)D concentrations; however, the vitamin D status of various indigenous groups of the Russian North is poorly studied. We could not find publications that analyze the 25(OH)D concentrations along with the direct assessment of food consumption. The available data do not contradict the opinion that the traditional food products are beneficial. However, there are no studies to support this opinion. There are little data on the effect of foods from marine mammal catch, marine and freshwater fishery, and venison on the vitamin D status of the indigenous people of the Russian North.
The purpose of the research was to study effect of longterm isolation on night sleep. The data were collected during international ground simulation of an interplanetary manned flight – “Mars500”. The polysomno graphic recordings of six healthy men were performed before, four times during and after 520days confine ment. During the isolation sleep efficiency and deltalatency decreased, while sleep latency increased. Post hoc analysis demonstrate significant differences between background and the last (1.5 months before the end of the experiment) measure during isolation. Frequency of nights with low sleep efficiency rose on the eve of the important for the crew events (simulation of Mars landing and the end of the confinement). Two weeks after the landing simulation, amount of the nights with a low sleep efficiency significantly decreased. There fore, anticipation of significant event under condition of longterm isolation might result in sleep worsening in previously healthy men, predominantly difficulties getting to sleep.
The perception of spatial and successive contexts of auditory information develops during human ontogeny. We compared event-related potentials (ERPs) recorded in 5- to 6-year-old children (N = 15) and adults (N = 15) in response to a digital series with omitted digits to explore age differences in the perception of successive auditory information. In addition, ERPs in response to the sound of falling drops delivered binaurally were obtained to examine the spatial context of auditory information. The ERPs obtained from the omitted digits significantly differed in the amplitude and latency of the N200 and P300 components between adults and children, which supports the hypothesis that the perception of a successive auditory structure is less automated in children compared with adults. Although no significant differences were found in adults, the sound of falling drops presented to the left ears of children elicited ERPs with earlier latencies and higher amplitudes of P300 and N400 components in the right temporal area. Stimulation of the right ear caused increasing amplitude of the N100 component in children. Thus, the observed differences in auditory ERPs of children and adults reflect developmental changes in the perception of spatial and successive auditory information.
The role of cortisol (Crt), dehydroepiandrosterone (DHEA) and DHEAsulfate (DHEAS) in stress responses were shown. The fluctuations in concentration of Crt, DHEA and DHEAS depending on age, sex and time of the day in norm and under acute and chronic stress were quoted. The main techniques of assessment of serum, urine and saliva Crt concentrations were discussed. A special attention had been paid to the use of Crt concentration in anthropological and psychological research. Bibliography comprises 181 works.