5 research outputs found
<i>Barranca variabilis</i> sp. nov.—A New Terrestrial Alga of the Genus <i>Barranca</i> (Chaetophorales, Chlorophyta) from the Baikal Region (Russia)
No full textFilamentous green chaetophoralean algae are distributed mainly in aquatic ecosystems, less known from terrestrial habitats. Many of them have a complicated thalli and complex life cycles that make it difficult to determine these organisms by morphology. Description of new representatives of the Chaetophorales continues. In this study, we have explored the filamentous green alga IRK–A 341 from soil of the Baikal Region by light and electron microscopy along with molecular phylogeny. Based on the results of morphological, ecological, and molecular phylogenetic analyses (18S–28S rDNA, tufA), we described the studied alga as the new species, Barranca variabilis sp. nov. The study complements the data on the diversity of soils green filamentous algae, and their biogeography. For the first time, the data on the structure of the cell walls and the cell ultrastructure of Barranca were established. The information on the morphology of the reproductive and resting cells is updated
Dates and Rates of Tick-Borne Encephalitis Virus—The Slowest Changing Tick-Borne Flavivirus
No full textWe evaluated the temporal signal and substitution rate of tick-borne encephalitis virus (TBEV) using 276 complete open reading frame (ORF) sequences with known collection dates. According to a permutation test, the TBEV Siberian subtype (TBEV-S) data set has no temporal structure and cannot be applied for substitution rate estimation without other TBEV subtypes. The substitution rate obtained suggests that the common clade of TBEV (TBEV-common), including all TBEV subtypes and louping-ill virus (LIV), is characterized by the lowest rate (1.87 × 10−5 substitutions per site per year (s/s/y) or 1 nucleotide substitution per ORF per 4.9 years; 95% highest posterior density (HPD) interval, 1.3–2.4 × 10−5 s/s/y) among all tick-borne flaviviruses previously assessed. Within TBEV-common, the TBEV European subtype (TBEV-E) has the lowest substitution rate (1.3 × 10−5 s/s/y or 1 nucleotide substitution per ORF per 7.5 years; 95% HPD, 1.0–1.8 × 10−5 s/s/y) as compared with TBEV Far-Eastern subtype (3.0 × 10−5 s/s/y or 1 nucleotide substitution per ORF per 3.2 years; 95% HPD, 1.6–4.5 × 10−5 s/s/y). TBEV-common representing the species tick-borne encephalitis virus diverged 9623 years ago (95% HPD interval, 6373–13,208 years). The TBEV Baikalian subtype is the youngest one (489 years; 95% HPD, 291–697 years) which differs significantly by age from TBEV-E (848 years; 95% HPD, 596–1112 years), LIV (2424 years; 95% HPD, 1572–3400 years), TBEV-FE (1936 years, 95% HPD, 1344–2598 years), and the joint clade of TBEV-S (2505 years, 95% HPD, 1700–3421 years) comprising Vasilchenko, Zausaev, and Baltic lineages
Investigation of Mechanical Engineering Academicians’ Use of Distance Education Technologies
No full textThe aim of this study is to determine the use of distance education technologies, conditions of use and how often they use various computer applications, and also to investigate the use of these applications by academicians who teach in the Department of Mechanical Engineering. In the research carried out with the scanning model, there were 370 volunteers from various universities in Russia, consisting of academicians who teach in the field of mechanical engineering. The research was carried out in the spring term of 2020–2021; before the research, a 6-week online training was given to mechanical engineer academicians. In the study, the ‘distance education technologies’ measurement tool developed by the researchers and compiled by experts in the field was used. The measurement tool was delivered to the academicians via the online method and collected. The analysis of the data was carried out by using the SPSS programme, frequency analysis, t-test and ANOVA test, and the results were added to the research with tables. Accord-ing to the results obtained from the research, although the distance education technologies of the academicians who teach in the field of mechanical engineering are satisfactory, the rate of academicians never using new technologies in the teaching process is quite low and the rate of using them very often is quite high
Genomic Determinants Potentially Associated with Clinical Manifestations of Human-Pathogenic Tick-Borne Flaviviruses
No full textThe tick-borne flavivirus group contains at least five species that are pathogenic to humans, three of which induce encephalitis (tick-borne encephalitis virus, louping-ill virus, Powassan virus) and another two species induce hemorrhagic fever (Omsk hemorrhagic fever virus, Kyasanur Forest disease virus). To date, the molecular mechanisms responsible for these strikingly different clinical forms are not completely understood. Using a bioinformatic approach, we performed the analysis of each amino acid (aa) position in the alignment of 323 polyprotein sequences to calculate the fixation index (Fst) per site and find the regions (determinants) where sequences belonging to two designated groups were most different. Our algorithm revealed 36 potential determinants (Fst ranges from 0.91 to 1.0) located in all viral proteins except a capsid protein. In an envelope (E) protein, most of the determinants were located on the virion surface regions (domains II and III) and one (absolutely specific site 457) was located in the transmembrane region. Another 100% specific determinant site (E63D) with Fst = 1.0 was located in the central hydrophilic domain of the NS2b, which mediates NS3 protease activity. The NS5 protein contains the largest number of determinants (14) and two of them are absolutely specific (T226S, E290D) and are located near the RNA binding site 219 (methyltransferase domain) and the extension structure. We assume that even if not absolutely, highly specific sites, together with absolutely specific ones (Fst = 1.0) can play a supporting role in cell and tissue tropism determination
