The Effect of Mineral Particulate Matter on the Productive Characteristics of Bacterioplankton and the Degradation of Labile Organic Material

The effect of mineral particulate matter on the population of bacterioplankton, its aggregation, and productive characteristics was studied in model experiments with different concentrations of particulate kaolin and the same concentration of organic substance (sodium humate). It was found that the presence of mineral particulate matter stimulated the aggregation of bacterioplankton, improved bacterial production, and extended the productive period of bacterioplankton. The integral specific production of aggregated bacterioplankton was higher than that of free-swimming bacterioplankton. The energy metabolic coefficient K ₂ of bacterioplankton in the presence of mineral particulate matter was higher than in its absence.     

Polyfluorinated salicylic acid derivatives as analogs of known drugs: Synthesis,molecular docking and biological evaluation

We have developed the convenient methods for synthesis of polyfluorosalicylic acids and their derivatives. For the first time the biological properties of polyfluorosalicylates were investigated in vitro (permeability through the biological membranes, COX-1 inhibitory action) and in vivo (anti-inflammatory, analgesic activities, acute toxicity). Molecular docking of polyfluorinated salicylates confirmed in vitro and in vivo experiments.     

Investigation of bacterioplankton in the loess-containing lake Khanka

Some characteristics of bacterioplankton—generation time, daily (P) and specific (P/B) bacterioplankton production, and bacterial metabolic coefficientK ₂—in the loess-containing Lake Khanka were determined using five modifications of the bacterial-count procedure with the fluorescent dyes fluorescamin and erythrosin. Experiments showed that the organomineral complex (OMC) in this lake is broken down by chemoorganoheterotrophic bacteria. The increase in the loess content of the lake water intensified bacterial growth and the cycles of potassium, silicon, and other biogenic elements. The addition of starch to a loess suspension activated the breakdown of OMC due to the adsorption of starch on the OMC/water interface and stimulation of the metabolism of attached bacteria.     

Pharmacogenomics of multiple sclerosis: Association of immune response gene polymorphisms with copaxone treatment efficacy

A complex association analysis of copaxone (glatiramer acetate) immunotherapy efficacy with allelic polymorphism of the number of immune response genes, including the genes for interferon β (IFNB1), transforming growth factor β1 (TGFB1), interferon γ (IFNG), tumor necrosis factor (TNF), interferon α/β receptor 1 (IFNAR1), CC chemokine receptor 5 (CCR5), interleukin 7 receptor subunit α (IL7RA), cytotoxic T-lymphocyte antigen 4 (CTLA4), and HLA class II histocompatibility antigen β chain (DRB1), was performed using the APSampler algorithm for 285 multiple sclerosis patients of Russian ethnicity. The results demonstrate that the polymorphic variants of CCR5, DRB1, IFNG, TGFB1, IFNAR1, IL7RA, and, possibly, TNF and CTLA4 contribute to the copaxone treatment response. Single alleles of CCR5 and DRB1 genes were reliably associated with treatment efficacy. Allelic variants of the other genes exerted a weaker, though still reliable, effect on the copaxone treatment response, but as part of bi- and triallelic combinations only. The study may provide a basis for a prognostic test allowing an individual choice of immune-modulating treatment for a patient with multiple sclerosis.     

Effect or preliminary filtration on the functional characteristics of bacterioplankton from Lake Khanka]

The dependence of the functional characteristics of bacterioplankton from the loess of Lake Khanka on the pore size of filtering materials was investigated. Soluble organic matter (SOM), bacteria, and bacterial consumers adsorbed on particles suspended in the lake water were found to filter differently depending on the pore size of the filtering material. Filters with pore size 4.5 microns (filters II) retained up to 20% of SOM and 20-30% of bacterial cells. Filters III with pore size 2.87 microns retained almost 50% SOM and about 40% of bacteria. The double layer of gauze no. 72 (referred to as filter I) with pores size 40 microns was unable to completely retain bacterial consumers. In the case of filtrates I and II, the generation time of bacterioplankton decreased with its increasing average daily concentration. In the case of filtrate III, the generation time of bacterioplankton was minimum and did not depend on its concentration. Oxygen consumption rates per one bacterial cell and per unit biomass in filtrates increased with decreasing pore size of the filters through which they had passed. The bacterial biomass and oxygen consumption rate increased exponentially in filtrates III and logarithmically in filtrates I.     

Inferring Adaptive Introgression Using Hidden Markov Models

Adaptive introgression—the flow of adaptive genetic variation between species or populations—has attracted significant interest in recent years and it has been implicated in a number of cases of adaptation, from pesticide resistance and immunity, to local adaptation. Despite this, methods for identification of adaptive introgression from population genomic data are lacking. Here, we present Ancestry_HMM-S, a hidden Markov model-based method for identifying genes undergoing adaptive introgression and quantifying the strength of selection acting on them. Through extensive validation, we show that this method performs well on moderately sized data sets for realistic population and selection parameters. We apply Ancestry_HMM-S to a data set of an admixed Drosophila melanogaster population from South Africa and we identify 17 loci which show signatures of adaptive introgression, four of which have previously been shown to confer resistance to insecticides. Ancestry_HMM-S provides a powerful method for inferring adaptive introgression in data sets that are typically collected when studying admixed populations. This method will enable powerful insights into the genetic consequences of admixture across diverse populations. Ancestry_HMM-S can be downloaded from https://github.com/jesvedberg/Ancestry_HMM-S/.     

Diatoms of some water bodies in northeastern West Siberia. Communication 1. Centrophyceae

In the phytoplankton of northeastern West Siberian water bodies, Bacillariophyta were a dominant group of the 7 most abundant algal divisions, with the occurrence of the members of the class Centrophyceae varying from 27 to 100%. Scanning electron microscopy revealed complete species composition of the class Centrophyceae that dominates the phytoplankton of Lake Delingde, the Delingde and Bol’shaya Kheta rivers (Aulacoseira, 3 species; Cyclostephanos, 1; Cyclotella, 5; Discostella, 1; Melosira, 1; Pliocaenicus, 1; Puncticulata, 1; Stephanodiscus, 6). The phytoplankton of the class Centrophyceae in the Taz River now has a new member, Puncticulata radiosa. New species of the genus Cyclotella in West Siberian algal flora were revealed: C. arctica, C. comensis, and C. vorticosa. The findings helped more precisely define the ranges of the rare taxa and add new diagnostic features to the diagnoses of C. comensis and Stephanodiscus invisitatus.     

VGsim: Scalable viral genealogy simulator for global pandemic

Accurate simulation of complex biological processes is an essential component of developing and validating new technologies and inference approaches. As an effort to help contain the COVID-19 pandemic, large numbers of SARS-CoV-2 genomes have been sequenced from most regions in the world. More than 5.5 million viral sequences are publicly available as of November 2021. Many studies estimate viral genealogies from these sequences, as these can provide valuable information about the spread of the pandemic across time and space. Additionally such data are a rich source of information about molecular evolutionary processes including natural selection, for example allowing the identification of new variants with transmissibility and immunity evasion advantages. To our knowledge, there is no framework that is both efficient and flexible enough to simulate the pandemic to approximate world-scale scenarios and generate viral genealogies of millions of samples. Here, we introduce a new fast simulator VGsim which addresses the problem of simulation genealogies under epidemiological models. The simulation process is split into two phases. During the forward run the algorithm generates a chain of population-level events reflecting the dynamics of the pandemic using an hierarchical version of the Gillespie algorithm. During the backward run a coalescent-like approach generates a tree genealogy of samples conditioning on the population-level events chain generated during the forward run. Our software can model complex population structure, epistasis and immunity escape.     

Effect of suspended mineral matter on production characteristics of bacterio- and phytoplankton

The effect was determined of organo-mineral detritus (OMD), one of the components of suspended mineral matter in aquatic ecosystems, on the production characteristics of bacterioplankton (bacterial production P _b and destruction of organic matter R _b, as well as bacterial growth efficiency BGE). The relation was determined between these parameters and the ratio of the content of suspended mineral matter M to the total organic carbon content (M/TOC). More active utilization of organic matter by bacterioplankton in the presence of OMD resulted in its positive effect on specific production characteristics of the phytoplankton.