Algal and cyanobacterial diversity in saline rivers of the Elton Lake Basin (Russia) studied via light microscopy and next-generation sequencing

Naturally saline rivers are known in various regions of the world. Saline rivers with a salinity gradient from the source to the mouth are particularly interesting, because the range of salinity is the structure-forming factor of the hydrobiont assemblage. Such rivers are represented by saline rivers of the Elton Lake Basin in Volgograd region of Russia (the Bolshaya Samoroda River and the Malaya Samoroda River). Herein, we analyzed taxonomic structure and species diversity of microalgae and Cyanobacteria of the saline rivers flowing into the Elton Lake by light microscopy and next-generation sequencing. The differences and possible causes of inconsistencies in the results obtained by these methods are discussed. In total, 91 taxa of microorganisms were identified by integrated approach in the assemblages of microalgae and Cyanobacteria in the middle course of the Bolshaya Samoroda River, and 60 taxa – in the river mouth. The species diversity of those assemblages in the hypersaline Malaya Samoroda River was lower: 27 taxa from the middle course and 23 taxa from the mouth. Next-generation sequencing allowed us to refine and expand the list of microalgae taxa in the studied saline rivers due to detection of species which were hard to identify, low-abundance taxa, as well as extremely small-cell forms. Some discrepancies between the data obtained by light microscopy and next-generation sequencing indicate the advantage of simultaneous use of both methods for study of the algae communities. Such a comprehensive approach provides the most accurate and correct list of taxa added with the morphological descriptions and 18S rRNA and 16S rRNA partial sequences. Generally, 18 taxa have been recorded for the first time in the Bolshaya Samoroda River, belonging to the phyla Chlorophyta (Borodinellopsis sp., Chlorochytrium lemnae Cohn, Caespitella sp., Halochlorococcum sp., Tetraselmis cordiformis (H. J. Carter) F. Stein), Ochrophyta (Pseudocharaciopsis ovalis (Chodat) D. J. Hibberd, Characiopsis sp., Poterioochromonas stipitata Scherffel, Chrysolepidomonas sp.), Euglenozoa (Euglena bucharica I. Kisselev, Lepocinclis tripteris (Dujardin) B. Marin & Melkonian, Phacus orbicularis K. Hübner, P. parvulus G. A. Klebs), Cryptophyta (Hemiselmis cryptochromatica C. E. Lane & J. M. Archibald, Rhodomonas sp., Hanusia phi J. A. Deane), Haptophyta (Pavlova sp.), Cyanobacteria (Johanseninema constrictum (Szafer) Hasler, Dvorák & Poulícková). Seven taxa have been detected for the first time in the algal and cyanobacterial assemblages of the Malaya Samoroda River from the phyla Chlorophyta (Tetraselmis cordiformis, T. arnoldii (Proschkina-Lavrenko) R. E. Norris, Hori & Chihara, T. tetrathele (West) Butcher, Pyrobotrys elongatus Korshikov), Cryptophyta (Hanusia phi), and Cyanobacteria (Synechococcus elongatus (Nägeli) Nägeli, Oscillatoria simplicissima Gomont)

Carst marble on Tyrnyauz deposit

The karst of marbles is considered as the least studied type of karst. Here we have pinpointed the karst area of the ore field of the Tyrnyauz deposit. Lithological and petrographic characteristics of the skarned marbles of Tyrnyauz are given, their chemical activity is determined. Tectonogenic fissure-karst drainage system of the deposit is analyzed. The main factors of karst formation have been determined and the development of the karst marbles of the Tyrnyauz ore field at various depths is predicte

Halotolerant strain of Chlorococcum oleofaciens from the Lake Elton Biosphere Reserve

Chlorococcum oleofaciens is one of the most studied representatives of the Chlorococcum genus, both on the ultrastructural and molecular levels. This alga is very interesting due to its ability to hypersynthetize saturated and unsaturated fatty acids and the possibility of using it as a promising object for biofuel production. This research is devoted to the study of the halotolerant strain of Ch. oleofaciens Ch-1 extracted from the water of the Khara River (Lake Elton Biosphere Reserve, Russia, a UNESCO World Heritage site), mineralization of 14‰. The strain Ch. oleofaciens Ch-1 was studied at the morphological level (light microscopy), as well as using molecular genetics methods (18S rDNA). The objectives of the study included establishing the range of halotolerance of the allocated strain of Ch. oleofaciens as a whole, revealing borders of level of mineralization that are optimum for algae growth, and also tracing features of its morphology and cycle of development in the conditions of various salinity. In the course of the studies performed it was established that the extracted strain of Ch. oleofaciens Ch-1 differed from the typical one by greater variability of some morphological features and had a wide ecological valence: the range of its halotolerance was 0–60‰. The maximum values of quantitative development of Ch. oleofaciens Ch-1 were registered at mineralization of 0–14‰. It is shown that with increasing salinity in the development cycle of the strain, the duration of the adaptation phase increases, the exponential phase decreases, small celled forms are replaced by large celled forms and reproduction features are noted. The obtained results can be used for selection of optimal conditions for cultivation of the halotolerant strain of Ch. oleofaciens for biotechnological purposes

Seismically safe parameters of confined blasting in levelling dry dock bottom

During construction of a dry dock, it became necessary to level the bottom of gneissic granite rock mass to 7 m by blastin

The hyperfine transition in light muonic atoms of odd Z

The hyperfine (hf) transition rates for muonic atoms have been re-measured for select light nuclei, using neutron detectors to evaluate the time dependence of muon capture. For $^{19}$F $\Lambda$$_{h}$ = 5.6 (2) $\mu$s$^{-1}$ for the hf transition rate, a value which is considerably more accurate than previous measurements. Results are also reported for Na, Al, P, Cl, and K; that result for P is the first positive identification.Comment: 12 pages including 5 tables and 4 figures, RevTex, submitted to Phys. Rev.

ECFA Detector R&D Panel, Review Report

Two special calorimeters are foreseen for the instrumentation of the very forward region of an ILC or CLIC detector; a luminometer (LumiCal) designed to measure the rate of low angle Bhabha scattering events with a precision better than 10$^{-3}$ at the ILC and 10$^{-2}$ at CLIC, and a low polar-angle calorimeter (BeamCal). The latter will be hit by a large amount of beamstrahlung remnants. The intensity and the spatial shape of these depositions will provide a fast luminosity estimate, as well as determination of beam parameters. The sensors of this calorimeter must be radiation-hard. Both devices will improve the e.m. hermeticity of the detector in the search for new particles. Finely segmented and very compact electromagnetic calorimeters will match these requirements. Due to the high occupancy, fast front-end electronics will be needed. Monte Carlo studies were performed to investigate the impact of beam-beam interactions and physics background processes on the luminosity measurement, and of beamstrahlung on the performance of BeamCal, as well as to optimise the design of both calorimeters. Dedicated sensors, front-end and ADC ASICs have been designed for the ILC and prototypes are available. Prototypes of sensor planes fully assembled with readout electronics have been studied in electron beams.Comment: 61 pages, 51 figure

Current environmental selection issues: selection of h. annuus l. for herbicide resistance

This article is devoted to the creation of a new material of sunflower fertility reducing agents, having an optimal combination of tribenuron-methyl resistance and a sufficient vegetation period for the production of hybrids in zones with a short frost-free vegetation period. Lines used as a source of tribenuron-methyl resistance were purchased by Sativa LLC at the University of North Dakota Seed Fund (USA). The maximum resistance to aherbicide treatment was demonstrated by plants of hybrid combinations received by using the paternal line B0708VG, which line was significantly superior to the B0707VG lin

Measurement of shower development and its Moli\`ere radius with a four-plane LumiCal test set-up

A prototype of a luminometer, designed for a future e+e- collider detector, and consisting at present of a four-plane module, was tested in the CERN PS accelerator T9 beam. The objective of this beam test was to demonstrate a multi-plane tungsten/silicon operation, to study the development of the electromagnetic shower and to compare it with MC simulations. The Moli\`ere radius has been determined to be 24.0 +/- 0.6 (stat.) +/- 1.5 (syst.) mm using a parametrization of the shower shape. Very good agreement was found between data and a detailed Geant4 simulation.Comment: Paper published in Eur. Phys. J., includes 25 figures and 3 Table

The p(d,p)d and p(d,p)pn reactions as a tool for the study of the short range internal structure of the deuteron

In recent time the deuteron structure at short distances is often treated from the point of view nonnucleonic degrees of freedom. In this paper the measurements of T-odd polarization observables using tensor polarized deuteron beam and polarized proton target or proton polarimeter are proposed to search the quark configurations inside the deuteron.Comment: 12 pages, 8 Postscript figures, submitted in Phys.Atom.Nuc