Current Issue


Volume 41, Issue 2, 2023



Ecology


RESEARCH MODEL ALGORITHM OF MERCURY POLLUTION IN URBAN AREAS AS A DECISION-MAKING TOOL: CASE STUDY THE CITY OF YEREVAN (ARMENIA)

DOI:10.55841/1728-791X-2023.2.41-4

G. Melkonyan

Pages 4-12

Mercury is the only element to have its own environmental convention, i.e., the Minamata Convention on Mercury, thus Hg has received considerable attention highlighting the importance of the Hg global pollution issue, that are more acute especially in cities. Here, we report the development of a comprehensive Research Model Algorithm (RMA) as a tool to present science-based form for decision makers using easy-to-understand visualized results and recommendations. As a case study was chosen the city of Yerevan. In the frame of RMA concept, according to the results of researches already carried out, environmental risks were identified in urban soils and dust, but a non-carcinogenic risk for urban population has not been detected. Results of potential pollution sources inventory identify insignificant geogenic and predominant anthropogenic Hg pollution sources. Developed recommendations state identification of Hg potential sources, targeted study of landfills, improvement of Hg monitoring system, implementation of targeted surveys of Yerevan.



Geobotany


APPROBATION OF THE AUSTRALIAN METHOD FOR ASSESSING THE RISK OF PLANT INVASION IN ARMENIA

DOI:10.55841/1728-791X-2023.2.41-13

H. Hovhannisyan

Pages 13-17

The article presents the results of an assessment of the invasiveness by 14 plant species (Acer negundo, Cirsium incanum, Ambrosia artemisiifolia, Conyza canadensis, Clematis vitalba, Helianthus tuberosus, Leucanthemum vulgare, Ailanthus altissima, Buddleja davidii, Robinia pseudoacacia, Grindelia squarrosa, Hippophae rhamnoides, Solidago canadensis) in Armenia. The method was developed by Gordon et al. (2010) for Australia and is currently applied in many countries[17,1,18,13]. The aim of this work was to assess the applicability of this method for Armenian conditions. The plant species we studied are already indicated as invasive in Armenia [6,7]. The use of method showed its efficiency for Armenian conditions, allowing us to recommend it for use in assessing the invasion risk for new intruders to Armenia.


Informatics


PROGRESSIVE CROSS-LINGUAL TRANSFER LEARNING

DOI:10.55841/1728-791X-2023.2.41-18

R. Necychev, A. Stepanyan

Pages 18-21

Most models in natural language processing (NLP) are being pretrained on English text. When the parameters’ number in the model gets more, the gap between English and other languages becomes harder to fill, and performance issues in other languages become problematic. To solve this issue, we present a new transfer learning approach that concentrates on knowledge transfer between two languages and makes a possible transfer to model size. After the transfer, we are looking to get a model of the same size as before. To make sure that model’s size doesn’t become a bottleneck in our approach, we train from scratch a model in our target language with a smaller size. After that, we use that model combined with the initial source model to construct token embeddings for the target model (which should be at the same size as source model) by contacting the vocabulary of both languages. The rest of the weights in the target model are same as in source model. This approach achieves the same outperforms standard language transfer method and gets 4 times faster convergence.


Physiology


CARDIAC CORRELATES OF NEURODEGENERATIVE CHANGES IN RATS IN THE FORMATION OF PARKINSON'S AND ALZHEIMER'S DISEASES

DOI:10.55841/1728-791X-2023.2.41-22

J.Sarkissian R. Sargsyan, M. Poghosayn,V. Sargsyan, H. Shahinyan

Pages 22-26

A series of electrophysiological studies showed a significant change in the excitatory-inhibitory reactions of neurons of the substantia nigra and amygdala in response to high-frequency stimulation of Corpus caudatus and hippocampus, respectively, in the process of formation of neurodegenerative changes. It has been shown that neurodegenerative processes in the body do not lead to significant changes in the frequency of the heart. Both in the model of the formation of Parkinson's disease and in the model of Alzheimer's disease, significant changes are observed in the nature of the variability of RR intervals and the spectral power density of RR intervals. In the model of Parkinson's disease, in accordance with the values of both electrophysiological and electrocardiological parameters, a possible protective role of parathyroid hormone in the development of the disease was revealed. For the first time, it was shown that Parkinson's and Alzheimer's diseases have a different effect on the amplitude-time parameters of the QRST electrocardiogram complex. The results obtained indicate the possibility of identifying diagnostically important cardiographic criteria for the formation of neurodegenerative diseases in humans.


Virology


IMMUNOPATHOLOGY OF PORCINE VIRAL HEMORRHAGIC FEVERS

DOI:10.55841/1728-791X-2023.2.41-27

A. Poghosyan

Pages 27-30

Many porcine hemorrhagic fever viruses with various virulence have been isolated worldwide. Their virulence ranges from low virulent strains without causing serious pathogenic effects to highly virulent strains that cause high mortality. Experimental data suggests that the host immune system plays an important role in pathogenesis of viral hemorrhagic fever. Also, these viruses have evolved different strategies to evade host immune responses. This paper summarizes current progress in understanding the pathogenesis and immune responses to porcine hemorrhagic fever viruses: Classical Swine Fever (CSF) virus and African Swine Fever (ASF) virus. CSF and ASF are emerging diseases in pigs that belong to the VHF (viral hemorrhagic fever) category. Despite some differences in clinical presentation, the pathologies of both CSF and ASF exhibit striking similarities, suggesting common underlying mechanisms. This similarity can be linked to the development of Systemic Inflammatory Response Syndrome (SIRS), which is a generalized inflammatory process observed in many generalized infections, including VHFs in humans.


Theoretical Physics


REVIEW ON ANOMALOUS HALL EFFECT IN ULTRACLEAN ELECTRONIC CHANNELS

DOI:10.55841/1728-791X-2023.2.41-31

D.S. Zohrabyan

Pages 31-35

In this review paper, we study normal and anomalous Hall effects for two-dimensional degenerate electron gas in ultraclean electronic channels. The general approach of a semiclassical description using a density matrix is demonstrated. An analysis of the transition from the hydrodynamic regime to the diffusion regime is presented for normal and anomalous contributions in the Hall field and a discussion of the transition from the ballistic regime to the diffusion regime is presented. The sign changing of the Hall voltage for transitions from hydrodynamic and ballistic regimes to diffusion for various magnetic fields was discussed. Key words: anomalous Hall effect, spin-orbit interaction, electron-electron collisions, hydrodynamics of electron liquid, ballistic motion of electrons.




Theoretical Physics


ROLE OF NEAR EDGE REGIONS IN THE ANOMALOUS HALL EFFECT

DOI:10.55841/1728-791X-2023.2.41-36

D.S. Zohrabyan

Pages 36-43

The anomalous Hall effect is theoretically studied in the transition from the diffusion regime to the hydrodynamic regime for two-dimensional degenerate electronic systems. The length of interparticle collisions is considered to be much less than the width of the electronic channel, and the length of electron momentum relaxation is arbitrary. All the main mechanisms of the anomalous Hall effect were taken into account: anomalous velocity, wave packet shift during scattering on impurities, and asymmetric scattering from defects. The main attention is paid to the analysis of contributions to the Hall field and voltage from semiballistic regions near the edges of the sample, the width of which is on the order of the relaxation length of the second angular harmonic of the electron distribution function. It is shown that these contributions always make parametrically small contributions to the difference in the anomalous Hall voltage at the edges of the sample.