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Introduction. The key step in agent-based modeling of epidemics, which allows researchers to take into account individual characteristics of people, is the creation of an artificial population. The main difficulty of this procedure is finding a balance between the detail of the population description and the computational efficiency of the calculations. The aim and objectives of the review: Critically analyze and summarize the current evidence on how to create artificial populations; evaluate the limitations and advantages of available approaches in solving various problems in epidemiology. Materials and methods. An analysis of literature sources devoted to agent-based modeling has been performed. The analysis is focused on algorithms for creating an artificial population with a given level of detail for modeling human respiratory infections. Results. The approaches to the creation of artificial populations are generalized. The main principles of realization of interaction between agents are revealed: by means of networks of contacts between agents and on the basis of taking into account the movement of agents between locations. The first approach is the most computationally efficient and simple; the second approach allows to better take into account the change in the behavior of agents during the development of the epidemic process. Conclusion. Agent-based modeling is an optimal tool for selecting the best scenario for epidemic control and investigating the role of individual characteristics of people in the development of epidemics. When creating an artificial population, it is important to include in the model factors that can be targeted for control. A significant limitation is the lack of factual data on population structure, but this can be overcome by using indirect data.

Aim. Compare the lytic efficiency and the kinetics of accumulation of vesicular stomatitis virus serotypes Indiana (VSV-IND) and New Jersey (VSV-NJ) on cell lines of mouse melanoma B16F10, human hepatocellular carcinoma HepG2 and human mammary adenocarcinoma MCF7.Materials and methods. The viability of mouse melanoma B16F10, human hepatocellular carcinoma HepG2 and human mammary adenocarcinoma MCF7 cell lines infected with VSV-IND and VSV-NJ viruses at different multiplicity of infection (10 MOI; 1 MOI; 0.1 MOI) was assessed after 24, 48 and 72 hours, and the half maximal inhibitory concentration (IC50) values were measured using the methyl tetrazolium test. The relationship with virus accumulation in cell culture was determined using reverse transcription – quantitative polymerase chain reaction; 50% tissue culture infectious dose (TCID50) of VSV-IND and VSV-NJ for B16F10, HepG2, MCF7 were calculated using the Reed-Muench method.Results. The most susceptible cell line for both viruses was B16F10: cell viability 72 hours after infection at 10 MOI was only 10.4% and 5.7% for VSV-IND and VSV-NJ, respectively. HepG2 cell viability at 72 hours post-infection at 10 MOI was 10.8% and 9.8% for VSV-IND and VSV-NJ, and for MCF7 adenocarcinoma it was 46.6% and 36.2%, respectively. Moreover, only in the B16F10 culture was a positive statistically significant correlation of medium strength established between the inhibition of cell viability and the accumulation of viral RNA: for VSV-IND r = 0.601 (p < 0.05); for VSV-NJ r = 0.668 (p < 0.05). HepG2 and MCF7 showed no significant correlation.Conclusion. The research results indicate the potential of using oncolytic viruses of the VSV-IND and VSV-NJ as a platform for the development of new recombinant viruses for virotherapy of solid tumors in combination with other types of treatment.

The PetrSU Botanic Garden is situated on the North-West shore of the Petrozavodsk bay of the Onego lake in the limits of the Solomennoye denudative-tectonic ridge on the absolute marks 33—123 m above sea-level. Small moraines of the last Upper Valdai ice accretion form a broken cover on volcanogenous sedimentary rocks of the Proterozoic and they are blocked here and there by sandy-gravel, lake-glacial or lake sediments fixing the grad- ual fall of the Onego basin’s level during the late-glacial and the post-glacial age. Paleoseismic dislocations of the post-glacial period are presented be seismic colluvial screes, by wrecked and deformed rocks. Rugged relief of the territory, the combination of the Quaternary sediments, different by their structure and dampness made for the diversity of the Botanic Garden’s present landscapes.

Orthoflaviviruses are arthropod-borne viruses that are transmitted by mosquitoes or ticks and cause a range of significant human diseases. Among the most important tick-borne orthoflaviviruses (TBFVs) is tick-borne encephalitis virus (TBEV), which is endemic in Eurasia, and Powassan virus, which is endemic in Asia and North America. There is a significant controversy regarding species assignment in the tick-borne encephalitis virus complex due to the complex phylogenetic, serological, ecological, and pathogenetic properties of viruses. Comparing the rate of non-synonymous to synonymous substitutions (dN/dS) over the course of tick-borne orthoflavivirus diversification suggests that there is a very strong stabilizing selection (Nei-Gojobori dN/dS < 0.1) among tick-borne orthoflaviviruses that differ by less than 13.5% amino acid/21.4% nucleotide sequences, and discretely more rapid accumulation of non-synonymous substitutions (dN/dS > 0.13) among more divergent viruses that belong to distinct species. This pattern was similarly observed in genome regions encoding structural (E) and non-structural (NS3) proteins. Below this distance threshold, viruses appear fit and strongly tied to their ecological niche, whereas above the threshold, a greater degree of adaptation appears necessary. This species criterion suggests that all subtypes of TBEV, all related ovine/caprine encephalomyelitis viruses, and Omsk hemorrhagic fever virus (OHFV) together correspond to a single species. Within this species, viruses make up 11 subtypes that are reliably segregated by a 10% nucleotide distance cut-off suggested earlier for TBEV. The same 10% subtype cut-off suggests that Powassan virus includes two subtypes, Powassan and Deer Tick virus.

Abstract Background The Wnt signaling pathway is activated by mutations in the APC and β-catenin genes in many types of human cancer. β-catenin is stabilized by these mutations and activates transcription in part by acting as a bridge between Tcf/LEF proteins and the HD2 domain of the BCL9 coactivator. We have previously described oncolytic adenoviruses with binding sites for Tcf/LEF transcription factors inserted into the early viral promoters. These viruses replicate selectively in cells with activation of the Wnt pathway. To increase the activity of these viruses we have fused the viral transactivator E1A to the BCL9 HD2 domain. Methods Luciferase assays, co-immunoprecipitation and Western blotting, immunofluorescent cell staining and cytopathic effect assays were used to characterize the E1A-HD2 fusion protein and virus in vitro. Growth curves of subcutaneous SW620 colon cancer xenografts were used to characterize the virus in vivo. Results The E1A-HD2 fusion protein binds to β-catenin in vivo and activates a Tcf-regulated luciferase reporter better than wild-type E1A in cells with activated Wnt signaling. Expression of the E1A-HD2 protein promotes nuclear import of β-catenin, mediated by the strong nuclear localization signal in E1A. Tcf-regulated viruses expressing the fusion protein show increased expression of viral proteins and a five-fold increase in cytopathic effect (CPE) in colorectal cancer cell lines. There was no change in viral protein expression or CPE in HeLa cells, indicating that E1A-HD2 viruses retain selectivity for cells with activation of the Wnt signaling pathway. Despite increasing the cytopathic effect of the virus in vitro, fusion of the HD2 domain to E1A did not increase the burst size of the virus in vitro or the anti-tumor effect of the virus in an SW620 xenograft model in vivo. Conclusion Despite an increase in the nuclear pool of β-catenin, the effects on viral activity in colon cancer cells were small, suggesting that factors acting downstream of β-catenin are limiting for viral replication and toxicity in these cells. The approach of fusing E1A to a protein domain implicated in oncogenic signaling could be used to selectively increase the activity of oncolytic viruses targeting several other pathways defective in cancer.

Spin-gapless semiconductor (SGS) is a new class of material that has been studied recently for potential applications in spintronics. This material behaves as an insulator for one spin channel, and as a gapless semiconductor for the opposite spin. In this work, we present results of a computational study of two quaternary Heusler alloys, MnCrNbAl and MnCrTaAl that have been recently reported to exhibit spin-gapless semiconducting electronic structure. In particular, using density functional calculations we analyze the effect of external pressure on electronic and magnetic properties of these compounds. It is shown that while these two alloys exhibit nearly SGS behavior at optimal lattice constants and at negative pressure (expansion), they are half-metals at equilibrium, and magnetic semiconductors at larger lattice constant. At the same time, reduction of the unit cell volume has a detrimental effect on electronic properties of these materials, by modifying the exchange splitting of their electronic structure and ultimately destroying their half-metallic/semiconducting behavior. Thus, our results indicate that both MnCrNbAl and MnCrTaAl may be attractive for practical device applications in spin-based electronics, but a potential compression of the unit cell volume (e.g. in thin-film applications) should be avoided.

The epitranscriptomic modification m6A is a prevalent RNA modification that plays a crucial role in the regulation of various aspects of RNA metabolism. It has been found to be involved in a wide range of physiological processes and disease states. Of particular interest is the role of m6A machinery and modifications in viral infections, serving as an evolutionary marker for distinguishing between self and non-self entities. In this review article, we present a comprehensive overview of the epitranscriptomic modification m6A and its implications for the interplay between viruses and their host, focusing on immune responses and viral replication. We outline future research directions that highlight the role of m6A in viral nucleic acid recognition, initiation of antiviral immune responses, and modulation of antiviral signaling pathways. Additionally, we discuss the potential of m6A as a prognostic biomarker and a target for therapeutic interventions in viral infections.

Hepatitis E virus (HEV; family Hepeviridae) infections cause >40,000 human deaths annually. Zoonotic infections predominantly originate from ungulates and occasionally from rats, highlighting the zoonotic potential of rodent-associated hepeviruses. We conducted host genomic data mining and uncovered two genetically divergent rodent-associated hepeviruses, and two bat-associated hepeviruses genetically related to known bat-associated strains. We thus analyzed 2,565 liver specimens from 108 rodent and shrew species sampled from globally understudied regions and hosts in Africa, Asia, and Latin America during 2011-2018 for hepeviruses by RT-PCR. We detected 63 positive field samples (2.5%, 95% CI 1.9-3.1) from 14 animal species, including two coinfections with genetically divergent strains and significant variation (X², P < 0.001) in detection rates between study sites. Strain-specific qRT-PCR assays showed virus concentrations between 9.2 × 10² and 3.2 × 109 copies/g. We recovered 24 near-complete hepeviral genomes from rodents, shrews, and bats, all showing three partially overlapping open reading frames (ORFs), some including putative late domains that may be associated with quasi-envelopment. Rodent-derived hepeviruses grouped into five clades clustering in basal sister relationship to human-(31 to 84% distance in translatedORF1-3) and rat-associated HEV. Parsimony-based analyses and cophylogenetic reconciliations revealed that rodents were predominant sources of hepeviral cross-order host shifts. Bayesian ancestral state reconstructions substantiated a direct origin of human-associated HEV in ungulates such as swine and camelids (posterior probability 0.8), whereas the nonrecent evolutionary origins of human-and ungulate-associated HEV were projected to rodent hosts (posterior probability > 0.9). Our results elucidate the genealogy of human HEV and warrant increased surveillance and experimental risk assessments for rodent-associated hepeviruses. [ABSTRACT FROM AUTHOR]

Gene therapies hold significant promise for treating previously incurable diseases. A number of gene therapies have already been approved for clinical use. Currently, gene therapies are mostly limited to the use of adeno-associated viruses and the herpes virus. Viral vectors, particularly those derived from human viruses, play a critical role in this therapeutic approach due to their ability to efficiently deliver genetic material to target cells. Despite their advantages, such as stable gene expression and efficient transduction, viral vectors face numerous limitations that hinder their broad application. These limitations include small cloning capacities, immune and inflammatory responses, and risks of insertional mutagenesis. This review explores the current landscape of viral vectors used in gene therapy, discussing the different types of DNA- and RNA-based viral vectors, their characteristics, limitations, and current medical and potential clinical applications. The review also highlights strategies to overcome existing challenges, including optimizing vector design, improving safety profiles, and enhancing transgene expression both using molecular techniques and nanotechnologies, as well as by approved drug formulations. [ABSTRACT FROM AUTHOR]

More than 100 types of non-polio enteroviruses (NPEVs) are ubiquitous in the human population and cause a variety of symptoms ranging from very mild to meningitis and acute flaccid paralysis (AFP). Much of the information regarding diverse pathogenic properties of NPEVs comes from the surveillance of poliovirus, which also yields NPEV. The analysis of 265 NPEV isolations from 10,433 AFP cases over 24 years of surveillance and more than 2500 NPEV findings in patients without severe neurological lesions suggests that types EV-A71, E13, and E25 were significantly associated with AFP. EV-A71 was also significantly more common among AFP patients who had fever at the onset and residual paralysis compared to all AFP cases. In addition, a significant disparity was noticed between types that were common in humans (CV-A2, CVA9, EV-A71, E9, and E30) or in sewage (CVA7, E3, E7, E11, E12, and E19). Therefore, there is significant evidence of non-polio viruses being implicated in severe neurological lesions, but further multicenter studies using uniform methodology are needed for a definitive conclusion.

We present computational results on electronic, magnetic, and structural properties of CoVMnSb, a quaternary Heusler alloy. Our calculations indicate that this material may crystallize in two energetically close structural phases: inverted and regular cubic. The inverted cubic phase is the ground state, with ferrimagnetic alignment, and around 80% spin polarization. Despite having a relatively large bandgap in the minority-spin channel close to the Fermi level, this phase does not undergo a half-metallic transition under pressure. This is explained by the "pinning" of the Fermi level at the minority-spin states at the Γ point. At the same time, the regular cubic phase is half-metallic and retains its perfect spin polarization under a wide range of mechanical strain. Transition to a regular cubic phase may be attained by applying uniform pressure (but not biaxial strain). In practice, this pressure may be realized by an atomic substitution of non-magnetic atoms (Sb) with another non-magnetic atom (Si) of a smaller radius. Our calculations indicate that 25% substitution of Sb with Si results in a half-metallic regular cubic phase being the ground state. In addition, CoVMnSb0.5Si0.5 retains its half-metallic properties under a considerable range of mechanical pressure, as well as exhibits thermodynamic stability, thus making this alloy attractive for potential spintronic applications. We hope that the presented results will stimulate experimental efforts to synthesize this compound. [ABSTRACT FROM AUTHOR]