Spectral and depolarization ratios for atmospheric ice particles of hexagonal and arbitrary shape within the framework of the physical optics and discrete dipoles

The optical characteristics of atmospheric ice particles are usually calculated within the framework of the physical optics approximation, since particle sizes generally vary from 10 to 1000 microns. However, the results of experimental measurements show that ice crystals up to 10 microns in size are observed in cirrus clouds of the upper tier. The report presents a solution to the problem of light scattering for particles, obtained in the framework of the methods of the physical optics and discrete dipoles. Based on the solution, such important optical characteristics as depolarization and spectral ratios were calculated. Two limiting cases are considered: ideal hexagonal particles and randomly shaped particles

Postglacial Expansion Routes and Mitochondrial Genetic Diversification of the Freshwater Pearl Mussel in Europe and North America

The freshwater pearl mussel Margaritifera margaritifera is a unionid species distributed across Northwestern Russia, Fennoscandia, Western and Southwestern Europe, and the Atlantic Coast of North America. In this study, we reconstructed the post-glacial expansion routes of this species based on FST genetic distances and the fact that M. margaritifera distribution is directly connected with salmonid expansion. The freshwater-pearl-mussel populations from North America and Northeastern Europe were the closest groups, judging by FST distances, supporting the concept of the North Atlantic Salmo salar colonization of the Barents and White Sea basins. We also documented that unique haplotypes in the populations of the Baltic and White Sea basins may have originated in isolated glacial refugia in Eastern and Northeastern Europe. The Iberian clade was the most distant group of populations, which is consistent with the previously observed role of the Iberian Peninsula as a glacial refugium. The high genetic diversity in the populations of Northern and Eastern Karelia was facilitated by migrants utilizing complex periglacial hydrological networks and by admixture in the contact zone where the migration flows met. We confirm that this region should be considered as a major center of genetic diversity within the European part of the species’ range

A Record of the Ratan Goby, Ponticola ratan (Gobiidae, Perciformes), in the Dneprodzerzhinsk Reservoir (Dnieper River)

The paper contains new data, which confirms distribution of the ratan goby, Ponticola ratan (Nordmann, 1840), in fresh waters, as well as its diagnosis, description, and brief information on its biology.Приведены новые данные, подтверждающие распространение бычка-ратана, Ponticola ratan (Nordmann, 1840), в пресных водах, а также его диагноз, описание, краткие сведения по биологии

Postglacial Expansion Routes and Mitochondrial Genetic Diversification of the Freshwater Pearl Mussel in Europe and North America

The freshwater pearl mussel Margaritifera margaritifera is a unionid species distributed across Northwestern Russia, Fennoscandia, Western and Southwestern Europe, and the Atlantic Coast of North America. In this study, we reconstructed the post-glacial expansion routes of this species based on FST genetic distances and the fact that M. margaritifera distribution is directly connected with salmonid expansion. The freshwater-pearl-mussel populations from North America and Northeastern Europe were the closest groups, judging by FST distances, supporting the concept of the North Atlantic Salmo salar colonization of the Barents and White Sea basins. We also documented that unique haplotypes in the populations of the Baltic and White Sea basins may have originated in isolated glacial refugia in Eastern and Northeastern Europe. The Iberian clade was the most distant group of populations, which is consistent with the previously observed role of the Iberian Peninsula as a glacial refugium. The high genetic diversity in the populations of Northern and Eastern Karelia was facilitated by migrants utilizing complex periglacial hydrological networks and by admixture in the contact zone where the migration flows met. We confirm that this region should be considered as a major center of genetic diversity within the European part of the species’ range

Using an Inducible Promoter of a Gene Encoding <i>Penicillium verruculosum</i> Glucoamylase for Production of Enzyme Preparations with Enhanced Cellulase Performance

<div><p>Background</p><p><i>Penicillium verruculosum</i> is an efficient producer of highly active cellulase multienzyme system. One of the approaches for enhancing cellulase performance in hydrolysis of cellulosic substrates is to enrich the reaction system with β -glucosidase and/or accessory enzymes, such as lytic polysaccharide monooxygenases (LPMO) displaying a synergism with cellulases.</p><p>Results</p><p>Genes <i>bglI</i>, encoding β-glucosidase from <i>Aspergillus niger</i> (AnBGL), and <i>eglIV</i>, encoding LPMO (formerly endoglucanase IV) from <i>Trichoderma reesei</i> (TrLPMO), were cloned and expressed by <i>P</i>. <i>verruculosum</i> B1-537 strain under the control of the inducible <i>gla1</i> gene promoter. Content of the heterologous AnBGL in the secreted multienzyme cocktails (hBGL1, hBGL2 and hBGL3) varied from 4 to 10% of the total protein, while the content of TrLPMO in the hLPMO sample was ~3%. The glucose yields in 48-h hydrolysis of Avicel and milled aspen wood by the hBGL1, hBGL2 and hBGL3 preparations increased by up to 99 and 80%, respectively, relative to control enzyme preparations without the heterologous AnBGL (at protein loading 5 mg/g substrate for all enzyme samples). The heterologous TrLPMO in the hLPMO preparation boosted the conversion of the lignocellulosic substrate by 10–43%; however, in hydrolysis of Avicel the hLPMO sample was less effective than the control preparations. The highest product yield in hydrolysis of aspen wood was obtained when the hBGL2 and hLPMO preparations were used at the ratio 1:1.</p><p>Conclusions</p><p>The enzyme preparations produced by recombinant <i>P</i>. <i>verruculosum</i> strains, expressing the heterologous AnBGL or TrLPMO under the control of the <i>gla1</i> gene promoter in a starch-containing medium, proved to be more effective in hydrolysis of a lignocellulosic substrate than control enzyme preparations without the heterologous enzymes. The enzyme composition containing both AnBGL and TrLPMO demonstrated the highest performance in lignocellulose hydrolysis, providing a background for developing a fungal strain capable to express both heterologous enzymes simultaneously.</p></div

Progress kinetics of Avicel hydrolysis by different <i>P. verruculosum</i> preparations.

<p>Conditions: substrate concentration 100 mg/mL; protein loading 5 mg/g substrate; CDH loading (when applied) 0.1 mg/g substrate; 50°C; pH 5.0.</p

The scheme of cloning pGA-BGL and pGA-EGIV plasmids.

<p>The scheme of cloning pGA-BGL and pGA-EGIV plasmids.</p

Progress kinetics of hydrolysis of pretreated aspen wood by different <i>P. verruculosum</i> preparations.

<p>Conditions: substrate concentration 100 mg/mL; protein loading 5 mg/g substrate; 50°C; pH 5.0.</p