Trends of the major porin gene (ompF) evolution

OmpF is one of the major general porins of Enterobacteriaceae that belongs to the first line of bacterial defense and interactions with the biotic as well as abiotic environments. Porins are surface exposed and their structures strongly reflect the history of multiple interactions with the environmental challenges. Unfortunately, little is known on diversity of porin genes of Enterobacteriaceae and the genus Yersinia especially. We analyzed the sequences of the ompF gene from 73 Yersinia strains covering 14 known species. The phylogenetic analysis placed most of the Yersinia strains in the same line assigned by 16S rDNA-gyrB tree. Very high congruence in the tree topologies was observed for Y. enterocolitica, Y. kristensenii, Y. ruckeri, indicating that intragenic recombination in these species had no effect on the ompF gene. A significant level of intra- and interspecies recombination was found for Y. aleksiciae, Y. intermedia and Y. mollaretii. Our analysis shows that the ompF gene of Yersinia has evolved with nonrandom mutational rate under purifying selection. However, several surface loops in the OmpF porin contain positively selected sites, which very likely reflect adaptive diversification Yersinia to their ecological niches. To our knowledge, this is a first investigation of diversity of the porin gene covering the whole genus of the family Enterobacteriaceae. This study demonstrates that recombination and positive selection both contribute to evolution of ompF, but the relative contribution of these evolutionary forces are different among Yersinia species

Twelve modified figures of merit of 2–2-type composites based on relaxor-ferroelectric single crystals

Twelve modified figures of merit are studied for the first time for 2–2-type composites based on relaxor-ferroelectric single crystals such as [001]-poled (1 – x)Pb(A1/3Nb2/3)O3 – xPbTiO3, where A = Mg or Zn. These modified figures of merit are related to the piezoelectric coefficients d3j* of the composite (j = 1, 2 and 3) and characterise the effectiveness of energy harvesting and transduction along the three co-ordinate axes OXj of a piezoelectric composite under a constant mechanical stress or strain. The volume-fraction dependencies of the modified figures of merit are analysed for parallel-connected 2–2 and 2–2–0 composites, and the effect of porosity (i.e. the volume fraction and shape of air pores in each polymer layer) on these figures of merit is considered for 2–2–0 composites. Linkages between the modified figures of merit and traditional energy-harvesting figures of merit d3j*g3j* are discussed for the studied 2–2-type composites. New diagrams are developed to indicate important volume-fraction ranges that correspond to a large anisotropy of exemplar modified figures of merit. Due to the large effective parameters and large anisotropy of specific figures of merit, the studied composites are of interest in piezoelectric sensor, transducer and energy-harvesting applications

Piezoelectric sensitivity and hydrostatic response of novel lead-free 2–0–2 composites with two single-crystal components

This paper reports the piezoelectric performance and important related hydrostatic parameters of 2–0–2 composites based on lead-free ferroelectric and piezoelectric single crystals with 4mm symmetry. We demonstrate that ferroelectric domain-engineered alkali niobate-tantalate based single crystals provide large values of the piezoelectric coefficients g3j ∗ and related parameters when used in a 2–0–2 composite system with a relatively wide range of volume fractions of single-crystal components. An ‘aspect-ratio effect’ as a result of the presence of inclusions of a piezoelectric Li2B4O7 single crystal in a polymer medium is studied for the first time for a case where the elastic compliance s12 in the single crystal/polymer layer of the composite passes through zero. It is observed that changes in the aspect ratio and volume fraction of the Li2B4O7 inclusions influence the hydrostatic piezoelectric coefficient gh ∗, squared figure of merit dh ∗gh ∗ and electromechanical coupling factor kh ∗ of the composite, and large values of gh ∗∼102 mV·m/N, dh ∗gh ∗∼ (10−11–10−10) Pa−1 and kh ∗≈ 0.6–0.7 are achieved. A link between max kh ∗ and a change in sgns12 is first described for the 2–2-type composite, and a comparison of the hydrostatic parameters of the novel and related composites is made. The present results show the potential of lead-free 2–0–2 composites that are suitable for piezoelectric sensor, energy-harvesting and hydroacoustic applications.</p

Theoretical Study on the Piezoelectric Performance of Lead-Free 1–3-Type Composites

The paper is devoted to the analysis of high-performance piezo-composites based on lead-free ferroelectric single crystals. The composite consists of parallelepiped-shaped single-crystal rods which are surrounded by a laminar polymer matrix, and the composite as a whole is described by 1–2–2 connectivity. Such a composite structure promotes high piezoelectric sensitivity and hydrostatic response. Of particular interest are piezoelectric coefficients g*33 and h*33, squared figure of merit d*33 g*33, electromechanical coupling factor k*t at the thickness-mode oscillation, and hydrostatic parameters g*h and d*h g*h. The influence of the laminar matrix on the aforementioned parameters is studied in a wide volume-fraction range. Examples of maxima and large anisotropy of some effective parameters are discussed for the 1–2–2 composites based on [Lix(K1−yNay)1−x](Nb1−zTaz)O3:Mn single crystals. The role of elastic properties of the laminar matrix in achieving large hydrostatic parameters and piezoelectric anisotropy of these composites is emphasised. Their effective parameters are compared to those of composites based on the lead-containing relaxor-ferroelectric single crystals and to specific parameters of poled textured ceramics. Advantages of the studied composites over the relaxor-ferroelectric-based composites and textured ceramics open up new possibilities to apply the 1–3-type lead-free composites as active elements of piezoelectric sensors, hydrophones, energy-harvesting, and transducer devices.</p

Correction of single error bursts beyond the code correction capability using information sets

The most important method of ensuring data integrity is correcting errors that occur during information storage, processing or transmission. The error-correcting coding methods are used to correct errors. In real systems, noise processes are correlated. However, traditional coding and decoding methods use decorrelation, and it is known that this procedure reduces the maximum achievable characteristics of coding. Thus, constructing computationally efficient decoding methods that would correct grouped errors for a wide class of codes is an actual problem. In this paper the decoding by information sets is used to correct single bursts. This method has exponential complexity when correcting independent errors. The proposed approach uses a number of information sets linearly growing with code length, which provides polynomial decoding complexity. A further reduction of the number of information sets is possible with the proposed method of using dense information sets. It allows evaluating both the set of errors potentially corrected by the code and the characteristics of the decoder. An improvement of the decoding method using an error vector counter is proposed, which allows in some cases to increase the number of corrected error vectors. This method allows significantly reducing the number of information sets or increasing the number of corrected error vectors according to the minimum burst length criterion. The proposed decoders allow correction of single error bursts in polynomial time for arbitrary linear codes. The results of experiments based on standard array show that decoders not only correct all errors within the burst correcting capability of the code, but also a significant number of error vectors beyond of it. Possible directions of further research are the analysis of the proposed decoding algorithms for long codes where the method of analysis based on the standard array is not applicable; the development and analysis of decoding methods for multiple bursts and the joint correction of grouped and random errors

Relationships between piezoelectric and energy-harvesting characteristics of 1–2–2 composites based on domain-engineered single crystals

The paper reports on the piezoelectric performance, electromechanical coupling and related energy-harvesting figures of merit of three forms of 1–2–2 composites based on domain-engineered single crystals. The effect of the single-crystal piezoelectric properties and elastic properties of the laminar polymer matrix on the appropriate figures of merit of the composite is studied. The main active components of the studied composites are [0 0 1]-poled perovskite-type single crystals with chemical compositions: 0.92Pb(Zn1/3Nb2/3)O3–0.08PbTiO3, 0.67Pb(Mg1/3Nb2/3)O3–0.33PbTiO3 and [Li x (K1−y Na y)1−x ](Nb1−z Ta z)O3: Mn, where x = 0.06, y = 0.1–0.3, z = 0.07–0.17, and the level of Mn doping is 0.25 mol. %. Examples of non-monotonic volume-fraction dependences of the piezoelectric properties, figures of merit and anisotropy factors are analysed. New diagrams are first built to demonstrate the volume-fraction regions where a large anisotropy of the piezoelectric coefficients d 3j * and electromechanical coupling factors k 3j * is achieved, and where energy-harvesting figures of merit of the composite are at least five times larger than analogous parameters of single-crystal components. The studied 1–2–2 composites are of interest as anisotropic materials with high piezoelectric sensitivity and large figures of merit which are important for sensor, energy-harvesting and related applications.</p

FEATURES OF IMMUNOCOMPETENT CELLS IN THE PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA AT PRIMARY DIAGNOSIS

Some basic parameters of immune profile have been investigated in 140 patients with chronic lymphocytic leukemia (CLL). There was shown that the cohort of CLL patients is heterogeneous for their immune profile as early as at primary diagnosis stage, showing sufficient differences in the numbers of immunocompetent cells in peripheral blood. In most cases, the interpretation of appropriate quantitative characteristics is quite difficult, if based on the conventional criteria. The numbers of activated T-lymphocytes and NK-cells were proven to be the most informative parameters of cellular immunity in this cohort. Progression of leukemic events shows a close association with only a single parameter under study, i.e., CD4+/CD8+ cell ratio

Hourly average values of solar wing parameters (flow rate and ion temperatures) according to data of measurements of the Venera-9 and Venera-10 automatic interplanetary stations on an Earth-Venus during the period June 1975 - April 1976

Four electrostatic analyzers with channel electron multipliers as detectors were used to measure solar wind ionic flow. The axes of the fields of vision of two of these analyzers were directed along the axis of the automatic interplanetary station, oriented towards the Sun, while the other two were turned in one plane at angles of +15 deg and -15 deg. The full hemisphere of the angular diagram of each analyzer was approximately 5 deg. The energetic resolution was approximately 6%, and the geometric energy was 0.002 sq cm ave. keV. Each analyzer covered an energetic range of approximately 10 in eight energetic intervals. Spectral distributions were processed in order to obtain the velocity and temperature of the protons. Tabular data show the hour interval (universal time) and the average solar wind velocity in kilometers per second

Assessment of the Psychological Well-Being of Russian Youth With the PERMA-Profiler

Received 25 June 2022. Accepted 16 November 2022. Published online 30 December 2022.This article presents the results of a survey of the psychological well-being of Russian youth based on the Russian version of the PERMA-Profiler. The survey was conducted at the beginning of 2021 and covered 11,811 respondents (males = 29.2%, females = 70.8%) aged 18–35 (49.2%, aged 18–22; 22.3%, aged 23–30; and 28.5%, aged 31–35) living in the central part of Russia. The survey’s results indicate that the country perform properly in terms of youth well-being. The scores of Russian respondents are significantly higher than the results reported by Butler and Kern for the UK, Greece, Korea, Italy, and the USA in their study of 2016 (this sample is referred to as a total sample). The Russian respondents scored higher compared to the total sample in the scales of Positive emotions and Relationships. The research data show different indicators of well-being in groups differing by gender, age, education, social, marital and parental status, living conditions, and income level. We also found some peculiar age- and gender-related differences regarding well-being in the Russian sample, which also distinguishes it from the total sample. The research results can be used in programs intended to improve the psychological well-being of Russian youth.This work was supported by the Russian Scientific Foundation (RSF), project No 22-28-20262

Evaluation of commercial traits in the accessions of Medicago sativa L. from Asia Minor

Background. One of the main tasks of the present-day breeding practice is the development of high-yielding intensive-type fodder crop cultivars for indoor feeding of livestock. Alfalfa, as a productive and high-protein crop, deserves special attention. An offer of new breeding sources would enable breeders to broaden the diversity of alfalfa cultivars. Objective. The present study involved 65 local varieties and wild accessions of alfalfa from Turkey preserved in the VIR collection. Material and methods. Yekaterinino Experiment Station of VIR (Tambov Province) was chosen as the research site. Evaluation of the alfalfa collection was carried out in 2015–2017, using the methods developed at VIR for fodder crop research targeted at such traits as green biomass yield, seed productivity, and leafiness. The cultivar ‘Marusinskaya 425’ was used as the reference. Results and conclusions. In 2015, four accessions were identified as promising for their green matter yield and seed productivity: local varieties k-3373 and k-3378 from Konya Province, k-5992 from Isparta Province, and k-6116 from Sivas Province. In 2016, three accessions exceeded the reference in the yield of green matter, and three accessions had higher seed productivity. Eight accessions surpassed the reference in leafiness. In 2017, only one accession, k-6009 (Kayseri Province), significantly exceeded the reference in green matter yield. Nine accessions were selected for their high seed yield. The maximum seed productivity was observed in the accession k-3379 (Konya). Leafiness was notably higher than the reference’s in 15 accessions. The average for three years shows that none of the accessions credibly surpassed the reference in green matter yield. Four accessions had higher seed productivity than the reference. According to the three-year average, 11 accessions exceeded the reference in leafiness. All in all, in the three years of study, the accessions k-3373, k-3378 and k-3379 (Konya) were selected for high green matter yield and seed productivity. High seed productivity and leafiness, with satisfactory green matter yield, were registered in the accession k-5992 (Isparta). The accession k-6009 (Kayseri) significantly exceeded the reference in green matter yield, but demonstrated low seed productivity and poor leafiness. The place of origin for the identified local accessions had been Central Anatolia, with its continental climate. These accessions are valuable breeding sources with noteworthy commercial traits. Alfalfa from Asia Minor can be recommended for use in breeding practice, targeted at the development of new high-yielding intensive-type cultivars