Influence of positional correlations on the propagation of waves in a complex medium with polydisperse resonant scatterers

We present experimental results on a model system for studying wave propagation in a complex medium exhibiting low frequency resonances. These experiments enable us to investigate a fundamental question that is relevant for many materials, such as metamaterials, where low-frequency scattering resonances strongly influence the effective medium properties. This question concerns the effect of correlations in the positions of the scatterers on the coupling between their resonances, and hence on wave transport through the medium. To examine this question experimentally, we measure the effective medium wave number of acoustic waves in a sample made of bubbles embedded in an elastic matrix over a frequency range that includes the resonance frequency of the bubbles. The effective medium is highly dispersive, showing peaks in the attenuation and the phase velocity as functions of the frequency, which cannot be accurately described using the Independent Scattering Approximation (ISA). This discrepancy may be explained by the effects of the positional correlations of the scatterers, which we show to be dependent on the size of the scatterers. We propose a self-consistent approach for taking this "polydisperse correlation" into account and show that our model better describes the experimental results than the ISA

The choice of the fuel assembly for VVER-1000 in a closed fuel cycle based on REMIX-technology

This paper shows basic features of different fuel assembly (FA) application for VVER-1000 in a closed fuel cycle based on REMIX-technology. This investigation shows how the change in the water–fuel ratio in the VVER FA affects on the fuel characteristics produced by REMIX technology during multiple recycling

Effect of horizontal magnetization reversal of the tips on magnetic force microscopy images

The effect of magnetization reversal of magnetic force microscope (MFM) tips based on low coercive thin-films on MFM images has been studied both experimentally and theoretically. By analyzing the MFM images obtained on structures with high magnetic stray fields we show that during the imaging process the magnetic state of the probe is modified anisotropically: the horizontal component of the magnetization follows the external field, whereas the vertical component of the magnetization stays almost constant. The observed complex magnetic behavior of the tip is explained theoretically based on the shape anisotropy of the tip. The obtained results are important for interpretation of MFM images of structures with high magnetic moment. Moreover, these results can be used for characterization of both laboratory-made and commercially available MFM tips

Dataset: Fauna of Adult Ground Beetles (Coleoptera, Carabidae) of the National Park “Smolny” (Russia)

(1) Background: Protected areas are “hotspots” of biodiversity in many countries. In such areas, ecological systems are preserved in their natural state, which allows them to protect animal populations. In several protected areas, the Coleoptera biodiversity is studied as an integral part of the ecological monitoring of the ecosystem state. This study was aimed to describe the Carabidae fauna in one of the largest protected areas of European Russia, namely National Park “Smolny”. (2) Methods: The study was conducted in April–September 2008, 2009, 2017–2021. A variety of ways was used to collect beetles (by hand, caught in light traps, pitfall traps, and others). Seasonal dynamics of the beetle abundance were studied in various biotopes. Coordinates were fixed for each observation. (3) Results: The dataset contains 1994 occurrences. In total, 32,464 specimens of Carabidae have been studied. The dataset contains information about 131 species of Carabidae beetles. In this study, we have not found two species (Carabus estreicheri and Calathus ambiguus), previously reported in the fauna of National Park “Smolny”. (4) Conclusions: The Carabidae diversity in the National Park “Smolny” is represented by 133 species from 10 subfamilies. Ten species (Carabus cancellatus, Harpalus laevipes, Carabus hortensis, Pterostichus niger, Poecilus versicolor, Pterostichus melanarius, Carabus glabratus, Carabus granulatus, Carabus arvensis baschkiricus, Pterostichus oblongopunctatus) constitute the majority of the Carabidae fauna. Seasonal dynamics are maximal in spring; the number of ground beetles decreases in biotopes by autumn

Biodiversity of Coleoptera (Insecta) in the Middle and Lower Volga Regions (Russia)

(1) Background: The conservation of entomofauna in individual macroregions requires efforts to study the distribution and abundance of insects. For this purpose, databases are created that enumerate this information. Such databases, with the processing of significant factual material, make it possible to objectively assess the status of a species and, if necessary, take measures for its protection. The aim of the paper is to describe the modern Coleoptera fauna in nine regions of Russia on the basis of a recently published dataset. (2) Methods: We conducted our own studies in 1994, 1996, 1998–2003 and 2005–2022. The dataset also includes data from museum specimens from other years. We used a variety of methods, such as sifting through litter, searching under the bark of trees and stumps, trapping by light, soil traps, beer traps, window traps, etc. For each observation, the coordinates of the find, the number of individuals observed and the date were recorded. (3) Results: The dataset contains data on 1469 species and subspecies of Coleoptera from 85 families found in the Volga Region. In total, there are 31,433 samples and 9072 occurrences in the dataset. (4) Conclusions: The largest families in terms of species diversity are Curculionidae (202 species), Carabidae (145 species) and Chrysomelidae (142 species). There are 54 species of Coleoptera with a northern range boundary in the macroregion, two species with a southern range boundary and one species with an eastern range boundary. Twenty-one invasive Coleoptera species have been recorded in the macroregion

Biodiversity of Coleoptera (Insecta) in the Middle and Lower Volga Regions (Russia)

(1) Background: The conservation of entomofauna in individual macroregions requires efforts to study the distribution and abundance of insects. For this purpose, databases are created that enumerate this information. Such databases, with the processing of significant factual material, make it possible to objectively assess the status of a species and, if necessary, take measures for its protection. The aim of the paper is to describe the modern Coleoptera fauna in nine regions of Russia on the basis of a recently published dataset. (2) Methods: We conducted our own studies in 1994, 1996, 1998–2003 and 2005–2022. The dataset also includes data from museum specimens from other years. We used a variety of methods, such as sifting through litter, searching under the bark of trees and stumps, trapping by light, soil traps, beer traps, window traps, etc. For each observation, the coordinates of the find, the number of individuals observed and the date were recorded. (3) Results: The dataset contains data on 1469 species and subspecies of Coleoptera from 85 families found in the Volga Region. In total, there are 31,433 samples and 9072 occurrences in the dataset. (4) Conclusions: The largest families in terms of species diversity are Curculionidae (202 species), Carabidae (145 species) and Chrysomelidae (142 species). There are 54 species of Coleoptera with a northern range boundary in the macroregion, two species with a southern range boundary and one species with an eastern range boundary. Twenty-one invasive Coleoptera species have been recorded in the macroregion

Spectrum and Frequency of the GJB2 Gene Pathogenic Variants in a Large Cohort of Patients with Hearing Impairment Living in a Subarctic Region of Russia (the Sakha Republic).

Pathogenic variants in the GJB2 gene, encoding connexin 26, are known to be a major cause of hearing impairment (HI). More than 300 allelic variants have been identified in the GJB2 gene. Spectrum and allelic frequencies of the GJB2 gene vary significantly among different ethnic groups worldwide. Until now, the spectrum and frequency of the pathogenic variants in exon 1, exon 2 and the flanking intronic regions of the GJB2 gene have not been described thoroughly in the Sakha Republic (Yakutia), which is located in a subarctic region in Russia. The complete sequencing of the non-coding and coding regions of the GJB2 gene was performed in 393 patients with HI (Yakuts-296, Russians-51, mixed and other ethnicities-46) and in 187 normal hearing individuals of Yakut (n = 107) and Russian (n = 80) populations. In the total sample (n = 580), we revealed 12 allelic variants of the GJB2 gene, 8 of which were recessive pathogenic variants. Ten genotypes with biallelic recessive pathogenic variants in the GJB2 gene (in a homozygous or a compound heterozygous state) were found in 192 out of 393 patients (48.85%). We found that the most frequent GJB2 pathogenic variant in the Yakut patients was c.-23+1G>A (51.82%) and that the second most frequent was c.109G>A (2.37%), followed by c.35delG (1.64%). Pathogenic variants с.35delG (22.34%), c.-23+1G>A (5.31%), and c.313_326del14 (2.12%) were found to be the most frequent among the Russian patients. The carrier frequencies of the c.-23+1G>A and с.109G>A pathogenic variants in the Yakut control group were 10.20% and 2.80%, respectively. The carrier frequencies of с.35delG and c.101T>C were identical (2.5%) in the Russian control group. We found that the contribution of the GJB2 gene pathogenic variants in HI in the population of the Sakha Republic (48.85%) was the highest among all of the previously studied regions of Asia. We suggest that extensive accumulation of the c.-23+1G>A pathogenic variant in the indigenous Yakut population (92.20% of all mutant chromosomes in patients) and an extremely high (10.20%) carrier frequency in the control group may indicate a possible selective advantage for the c.-23+1G>A carriers living in subarctic climate

Prevalence of congenital HI caused by biallelic <i>GJB2</i> pathogenic variants in the Sakha Republic.

<p>Note: The territory of the Sakha Republic is shown in blue (bottom map). HI rates were calculated per 10,000 people, and appropriate data are presented only for the districts and cities of the Sakha Republic with population more than 10,000. Detailed data are presented in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0156300#pone.0156300.s001" target="_blank">S1 Table</a>.</p

Spectrum and Frequency of the <i>GJB2</i> Gene Pathogenic Variants in a Large Cohort of Patients with Hearing Impairment Living in a Subarctic Region of Russia (the Sakha Republic) - Fig 1

<p>Detected pathogenic and benign variants in the <i>GJB2</i> gene in patients (A) and control groups (B). Note: Pathogenic variants are shown in red, benign variants are shown in blue; *—unclassified variant, b.p.—base pair.</p