Migratory birds are able to choose the appropriate migratory direction under dim yellow narrowband light.

Currently, it is generally assumed that migratory birds are oriented in the appropriate migratory direction under UV, blue and green light (short-wavelength) and are unable to use their magnetic compass in total darkness and under yellow and red light (long-wavelength). However, it has also been suggested that the magnetic compass has two sensitivity peaks: in the short and long wavelengths, but with different intensities. In this project, we aimed to study the orientation of long-distance migrants, pied flycatchers (Ficedula hypoleuca), under different narrowband light conditions during autumn and spring migrations. The birds were tested in the natural magnetic field (NMF) and a changed magnetic field (CMF) rotated counterclockwise by 120° under dim green (autumn) and yellow (spring and autumn) light, which are on the 'threshold' between the short-wavelength and long-wavelength light. We showed that pied flycatchers (i) were completely disoriented under green light both in the NMF and CMF but (ii) showed the migratory direction in the NMF and the appropriate response to CMF under yellow light. Our data contradict the results of previous experiments under narrowband green and yellow light and raise doubts about the existence of only short-wavelength magnetoreception. The parameters of natural light change dramatically in spectral composition and intensity after local sunset, and the avian magnetic compass should be adapted to function properly under such constantly changing light conditions.

Data on the heterotrophic bacterioplankton and concurrent environmental characteristics in the outer shelf and slope area of the Laptev Sea (Arctic Ocean).

In regions close to the continental shelf edge, the transfer of particulate organic carbon (POC) within the food web and with downward fluxes contributes to the long-term storage of carbon in deep basins. The degradation of POC by heterotrophic prokaryotes is one of the key indices of biological productivity and ecosystem functioning. Here we present data on the spatial and vertical distribution of the total bacterial abundance, fraction of high DNA-content and particle-associated bacteria, and POC concentration. Additionally we determined environmental parameters (temperature, salinity, turbidity, fluorescence and dissolved oxygen concentration). The data were collected in the Vilkitsky Strait and along two transects from the outer shelf of the Laptev Sea to the adjacent continental slope region of the Arctic Ocean in August-September 2018. Principal component analysis was used to reveal relationships between environmental factors and bacterial characteristics. Total bacterial abundance (BA) was positively correlated with seawater fluorescence, dissolved oxygen concentration and POC, but negatively linked to depth and salinity. The percentage of both particle-associated bacteria (%PAB) and bacteria with high DNA concentration (%HDNA) were positively linked to depth and salinity. The data obtained may be useful for a comprehensive assessment of the state of ecosystems in the vicinity of the Arctic continental slope under changing environmental conditions, as well as for studying microbial input in the carbon cycle.

Ontogeny of the star compass in birds: pied flycatchers (Ficedula hypoleuca) can establish the star compass in spring.

The star compass of birds, like the sun compass, is not innate. To possess either of them, birds have to observe the rotating sky and determine its centre of rotation (in the case of the star compass) or the sun's movement (for the sun compass). Young birds are believed to learn how to use the star compass before their first migration, even though the evidence of this is lacking. Here, we tested whether hand-raised Pied flycatchers (Ficedula hypoleuca) that had not established the star compass prior to their first autumn migration can gain it later in their ontogeny, in spring. We also attempted to examine whether the observation of diurnal celestial cues (the sun and polarized light) prior to autumn migration would affect the process of star compass learning in spring. When tested in the vertical magnetic field under the natural starry sky, the group of birds that observed the stars in spring as the first celestial cues were able to choose the migratory direction. In contrast, the birds that had never seen the stars were not able to use the nightly celestial cues in the vertical magnetic field. However, birds that had seen the daytime celestial cues till autumn and the stars at spring were disoriented, although this might be due to the small sample size. Our data suggest the possibility that the star compass may be learned in spring and emphasize the necessity for further research into the interaction of celestial compasses.

Redox Regulation of Neutrophils and Monocytes in Different Types of Myocardial Infarction.

The common aspect in pathogenetic mechanism of occurrence of myocardial infarction with presence or absence of pathologic Q-wave on electrocardiogram, is associated with systemic inflammatory process with involvement of activated neutrophils and monocytes, whose increased oxygen radical production may lead to damage of endothelial cells and cardiomyocyte lipid membranes. For neutrophils and monocytes redox regulation study, 58 myocardial infarction patients were examined by means of chemiluminescenne and nitroblue tetrasolium test. Significant increase of phagocyte functional activity in all patients was observed. Substantially higher parameters of neutrophil hydrogen peroxide and hypochloric acid production were revealed in Q-wave myocardial infarction patients. This assumes the prevalence of irreversible lipid peroxidation in cardiomyocytes destruction process because of neutrophil redox metabolism activation. The absence of significant difference in neutrophil superoxide production and plasma superoxide dismutase in both types of myocardial infarction suggests not only the sufficient functional reserve of their membrane NADPH-oxidase, but the presence of an additional source of active oxygen forms, probably associated with xantinoxidase reaction with activated neutrophil protease participation. The evaluated more expressed chemiluminescence activation index in Q-wave myocardial infarction patients reflects the exhaustion of plasma "antiradical potential", associated with the decrease of antioxidant reserve, and creating conditions for uncontrollable lipid peroxidation intensification. Thus, the heterogeneity of redox metabolism of neutrophils and monocytes in non-Q-myocardial infarction and Q-myocardial infarction patients reflects the difference in cardiomyocyte damage mechanisms in both types of ischemic heart disease aggravation.