Том 37, № 2 (2023)

Neurodegenerative retinal diseases such as age-related macular degeneration, glaucoma, and diabetic retinopathy remain the leading causes of low vision and blindness worldwide. Visual rehabilitation of patients who are visually impaired due to neurodegenerative diseases of the retina requires solving problems associated with a violation of the structure of neural networks and a deficiency of visual functions provided by these networks. Despite certain successes in the application of innovative methods of therapy, it is important to develop new approaches to visual rehabilitation to improve the quality of life of visually impaired patients. In visual rehabilitation, not only medical, but also various non-pharmacological therapy strategies are widely used to protect and restore the structure of the retina and its function. Among them, a separate niche is occupied by the technologies of vision stimulation therapy (phototherapy), the analysis of the main aspects of which is the task of this review. The vector of new research in the field of phototherapy is aimed at developing methods that can maximize the plasticity of the visual system to increase the effectiveness of its protection and recovery in neurodegenerative pathology. In this regard, new technologies of fractal phototherapy have great potential in visual rehabilitation.

The attraction of nocturnal insects to light is a known phenomenon with unknown physiological mechanisms. Moths of the pyralid family are characterized by the most pronounced response to light, but the spectral preferences of these insects have not been studied. The adzuki been borers Ostrinia scapulalis, which live on dicotyledonous plants, are the ancestral form for the Asian and European corn borers, widespread pests of corn. Using a wind tunnel modified to deliver light stimuli, we tested the responses of males and females to light stimuli with wavelengths of 532, 440 and 365 nm at 2 lux, capable of stimulating photoreceptors of compound eyes (with maximum sensitivity of 352, 413, 480 and 530 nm) as well as simple ocelli, whose sensitivity had the main peak in ultraviolet and additional one in the green spectrum (360 and 520 nm). It turned out that ultraviolet was the most attractive stimulus. A small percentage of insects responded to green light, but showed a freezing reaction near the light source. The least attractive was blue light, which also caused freezes. Thus, the flight of O. scapulalis adults is induced by short-wavelength light, the response is more consistent with the sensitivity of the ocelli than the compound eyes; blue and green light leads to a masking effect.

Before and after the 8-month international experiment SIRIUS 20/21, a complex of electrophysiological testing of the visual system was performed, including registration of standard photopic electroretinograms (ERG), flicker ERG response on flickering with a frequency of 8.3, 10, 12 and 24 Hz, photopic negative response, and pattern-ERG. The aim of the work was an objective assessment of changes in the functional activity of retinal neurons in ground station crew members associated with long-term isolation and the influence of a complex of stress factors. The results obtained indicate a moderate activation of the bioelectrical activity of photoreceptors and bipolar cells and a slight decrease in the function of retinal ganglion cells after isolation experiment. The revealed changes may reflect the adaptation of the visual sensory system of the testers to physical and psycho-emotional stress in the experimental conditions. Further study of the specifics of changes in electroretinographic markers with a longer duration of the experiment is necessary to expand the understanding of stress resistance and adaptation of the visual system during prolonged exposure to extreme environmental conditions.

Short-latency auditory brainstem evoked potentials (ABR) to paired sound pulses (the conditioning and test stimuli) were recorded non-invasively in a bottlenose dolphin Tursiops truncatus. The stimuli were played through transducers contacting the left and right acoustic windows at the lower jaw. Two manners of stimulation were used: monaural (the both stimuli played through one and the same transducer) and dichotic (the conditioning and test stimuli played through different transducers, contacting the left and right acoustic window). Thе conditioning and test stimuli were equal in level and duration. The inter-stimulus delay varied from 0.15 to 10 ms. At the monaural stimulation, the suppression of the test stimulus was constant at interstimulus intervals from 0.15 to 0.5 ms; at longer intervals, the test response recovered. At the dichotic stimulation, the deepest suppression of the test response appeared at an interval of 0.5 ms; the test response recovered at both shorter and longer intervals. The complete recovery appeared at intervals as short as 0.15 ms and as long as 2 ms. Implications of the found regularities for the preceding effect and biosonar is discussed.

The paper considers the problem of classification of agricultural crops. As is known, to solve this problem, it is much more efficient to use not instantaneous remote sensing data or calculated vegetation indices, but their historical series. Time series formed by index values for a fixed spatial point at different dates are characterized by a high level of missing values, caused primarily by cloudiness on some dates. A study of known methods of time series approximation has been carried out. The question of whether reducing the dimensionality of the approximated time series can improve the quality of crops classification is also investigated. In the experimental part of the work, NDVI time series calculated from the Sentinel-2 multispectral satellite data were used. The classification of corn, sunflower, wheat and soybeans was studied. The paper shows that UMAP usage for dimensionality reduction leads to 1.5 times increase of classification quality in terms of average the F1-measure compared to using the original dimension data. A new crop classification method based on cubic spline approximation of NDVI time series, extraction of features of low dimension by the UMAP algorithm and their classification by the k nearest neighbors method is proposed.