Phylogeny, phylogeography and hybridization of Caucasian barbels of the genus Barbus (Actinopterygii, Cyprinidae)

Phylogenetic relationships and phylogeography of six species of Caucasian barbels, the genus Barbus s. str., were studied based on extended geographic coverage and using mtDNA and nDNA markers. Based on 27 species studied, matrilineal phylogeny of the genus Barbus is composed of two clades ¿ (a) West European clade, (b) Central and East European clade. The latter comprises two subclades: (b1) Balkanian subclade, and (b2) Ponto-Caspian one that includes 11 lineages mainly from Black and Caspian Sea drainages. Caucasian barbels are not monophyletic and subdivided for two groups. The Black Sea group encompasses species from tributaries of Black Sea including re-erected B. rionicus and excluding B. kubanicus. The Caspian group includes B. ciscaucasicus, B. cyri (with B. goktschaicus that might be synonymized with B. cyri), B. lacerta from the Tigris-Euphrates basin and B. kubanicus from the Kuban basin. Genetic structure of Black Sea barbels was influenced by glaciation-deglaciation periods accompanying by freshwater phases, periods of migration and colonization of Black Sea tributaries. Intra- and intergeneric hybridization among Caucasian barbines was revealed. In the present study, we report about finding of B. tauricus in the Kuban basin, where only B. kubanicus was thought to inhabit. Hybrids between these species were detected based on both mtDNA and nDNA markers. Remarkably, Kuban population of B. tauricus is distant to closely located conspecific populations and we consider it as relic. We highlight revealing the intergeneric hybridization between evolutionary tetraploid (2n=100) B. goktschaicus and evolutionary hexaploid (2n=150) Capoeta sevangi in Lake Sevan.The study was supported by Russian Science Foundation (grant no. 15-14-10020); final stage of the study was supported by Russian Foundation for Basic Research (grants nos. 18-54-05003 and 19-04-00719)

Examples of asymptotic solutions obtained by the complex germ method for the one-dimensional nonlocal Fisher–Kolmogorov–Petrovsky–Piskunov equation

The general construction of the Cauchy problem solution for the one-dimensional nonlocal population Fisher– KPP equation is briefly described in terms of semiclassical asymptotics based on the complex WKB-Maslov method. For the particular case of the equation under consideration, a family of leading terms of the semiclassical asymptotics is constructed in an explicit form, and their qualitative behavior is investigated. The behavior of the asymptotic solutions and of the corresponding numerical solutions constructed using the software package Comsol Multiphysics is compared

Pt-Mo/C, Pt-Fe/C and Pt-Mo-Sn/C Nanocatalysts Derived from Cluster Compounds for Proton Exchange Membrane Fuel Cells

Nanosized bimetallic PtMo, PtFe and trimetallic PtMoSn catalysts deposited on highly dispersed carbon black Vulcan XC-72 were synthesized from the cluster complex compounds PtCl(P(C6H5)3)(C3H2N2(CH3)2)Mo(C5H4CH3)(CO)3, Pt(P(C6H5)3)(C3N2H2(CH3)2)Fe(CO)3(COC6H5C2C6H5), and PtCl(P(C6H5)3)(C3N2H2(CH3)2)C5H4CH3Mo(CO)3SnCl2, respectively. Structural characteristics of these catalysts were studied using X-ray diffraction (XRD), microprobe energy dispersive spectroscopy (EDX), and transmission electron microscopy (TEM). The synthesized catalysts were tested in aqueous 0.5 M H2SO4 in a three-electrode electrochemical cells and in single fuel cells. Electrocatalytic activity of PtMo/C and PtFe/C in the oxygen reduction reaction (ORR) and the activity of PtMoSn/C in electrochemical oxidation of ethanol were evaluated. It was shown that specific characteristics of the synthesized catalysts are 1.5–2 times higher than those of a commercial Pt(20%)/C catalyst. The results of experiments indicate that PtFe/C, PtMo/C, and PtMoSn/C catalysts prepared from the corresponding complex precursors can be regarded as promising candidates for application in fuel cells due to their high specific activity

Controlled stripes of ultrafine ferroelectric domains

In the pursuit of ferroic-based (nano) electronics, it is essential to minutely control domain patterns and domain switching. The ability to control domain width, orientation and position is a prerequisite for circuitry based on fine domains. Here, we develop the underlying theory towards growth of ultra-fine domain patterns, substantiate the theory by numerical modelling of practical situations and implement the gained understanding using the most widely applied ferroelectric, Pb(Zr, Ti)O-3, demonstrating controlled stripes of 10 nm wide domains that extend in one direction along tens of micrometres. The observed electrical conductivity along these thin domains embedded in the otherwise insulating film confirms their potential for electronic applications

Small-molecule inhibition of pyruvate phosphate dikinase targeting the nucleotide binding site

Pyruvate phosphate dikinase (PPDK) is an essential enzyme of C4 photosynthesis in plants, catalyzing the ATP-driven conversion of pyruvate to phosphoenolpyruvate (PEP). It is further used by some bacteria and unicellular protists in the reverse, ATP-forming direction. Many weed species use C4 photosynthesis in contrast to world's major crops, which are C3 plants. Hence inhibitors of PPDK may be used as C4-specific herbicides. By screening a library of 80 commercially available kinase inhibitors, we identified compounds derived from bisindolylmaleimide (bisindolylmaleimide IV, IC50 = 0.76 ± 0.13 μM) and indirubin (indirubin-3'-monoxime, IC50 = 4.2 ± 0.9 μM) that showed high inhibitory potency towards PPDK and are among the most effective PPDK inhibitors described today. Physiological studies on leaf tissues of a C4 model plant confirmed in vivo inhibition of C4-driven photosynthesis by these substances. Moreover, comparative docking studies of non-inhibitory bisindolylmaleimide derivatives suggest that the selectivity towards PPDK may be increased by addition of functional groups to the core structure