DNA double-strand breaks induced by high NaCl occur predominantly in gene deserts

High concentration of NaCl increases DNA breaks both in cell culture and in vivo. The breaks remain elevated as long as NaCl concentration remains high and are rapidly repaired when the concentration is lowered. The exact nature of the breaks, and their location, has not been entirely clear, and it has not been evident how cells survive, replicate, and maintain genome integrity in environments like the renal inner medulla in which cells are constantly exposed to high NaCl concentration. Repair of the breaks after NaCl is reduced is accompanied by formation of foci containing phosphorylated H2AX (γH2AX), which occurs around DNA double-strand breaks and contributes to their repair. Here, we confirm by specific comet assay and pulsed-field electrophoresis that cells adapted to high NaCl have increased levels of double-strand breaks. Importantly, γH2AX foci that occur during repair of the breaks are nonrandomly distributed in the mouse genome. By chromatin immunoprecipitation using anti-γH2AX antibody, followed by massive parallel sequencing (ChIP-Seq), we find that during repair of double-strand breaks induced by high NaCl, γH2AX is predominantly localized to regions of the genome devoid of genes (“gene deserts”), indicating that the high NaCl-induced double-strand breaks are located there. Localization to gene deserts helps explain why the DNA breaks are less harmful than are the random breaks induced by genotoxic agents such as UV radiation, ionizing radiation, and oxidants. We propose that the universal presence of NaCl around animal cells has directly influenced the evolution of the structure of their genomes

Application of Laser Radiation for Fabrication of Micromechanical Actuator Based on Two-Way Shape Memory Effect

The work deals with production and research of experimental samples of micromechanical actuator based on the rapidly quenched TiNiCu alloy, in which a two-way shape memory effect is formed as result of impact of the laser radiation. By the technique of focused ion beams an element with thickness of 5 microns, width of 7 microns and 100 microns in length was obtained, bending reversibly to 2.5 microns in the heating-cooling cycle. Keywords: shape-memory alloy, thin ribbon, two-way shape memory effect, laser treatment, micromechanical actuato

A discrete slug population model determined by egg production

Slugs are significant pests in agriculture (as well as a nuisance to gardeners), and it is therefore important to understand their population dynamics for the construction of efficient and effective control measures. Differential equation models of slug populations require the inclusion of large (variable) temporal delays, and strong seasonal forcing results in a non-autonomous system. This renders such models open to only a limited amount of rigorous analysis. In this paper, we derive a novel batch model based purely upon the quantity of eggs produced at different times of the year. This model is open to considerable reduction; from the resulting two variable discrete-time system it is possible to reconstruct the dynamics of the full population across the year and give conditions for extinction or global stability and persistence. Furthermore, the steady state temporal population distribution displays qualitatively different behavior with only small changes in the survival probability of slugs. The model demonstrates how small variations in the favorability of different years may result in widely different slug population fluctuations between consecutive years, and is in good agreement with field data

Geotechnical properties of gullying in Tomsk Oblast

The article deals with causes, conditions and factors of gullying in Tomsk Oblast, the case of site Grodnenskaya. A nuclear-power station was planned to be constructed in Closed Administrative Territorial Unit Seversk, which led to geotechnical investigation of the area to study the geological processes developing there. The investigation included reconnaissance traverse of the area, geological and geomorphic descriptions, and sampling. The area and percentage of the territory affected by the geological processes were estimated. As a result, it was proved that the geological processes of the area are conditioned by surface water activity leading to gullying and river erosion, and by both ground water and surface water activity resulting in bog formation. It appears that gullying is caused not only by natural factors but also by technogenic ones

Microcotyle omanae n. sp. (Monogenea: Microcotylidae), a parasite of Cheimerius nufar (Valenciennes) (Sparidae) from the Arabian Sea

Microcotyle omanae n. sp. (Monogenea: Microcotylidae) is described from the gills of Cheimerius nufar (Valenciennes) (Sparidae) from the Arabian Sea. The new species closely resembles Microcotyle arripis Sandars, 1945, M. helotes Sandars, 1944, M. caudata Goto, 1984 and M. sebastis Goto, 1984, which have also been found in the Indo-Pacific. Microcotyle omanae n. sp. differs from M. arripis, M. helotes and M. caudata by its greater number of testes, from M. arripis, M. helotes by its greater length of the genital atrium, length/width ratio of the genital atrium and length of the eggs, and from M. helotes also in greater width of the clamps, from M. caudata and M. sebastis in its greater number of clamps and additionally from M. sebastis by its smaller genital atrial spines and clamps and by the ratio between length and width of the genital atrium. Moreover, the mature specimens of the new species have greater average body length than all above mentioned species. Correlations between 15 morphometric characters and body length are analysed in the new species, and their significance for species differentiation is discussed

ГАЗОХРОМАТОГРАФИЧЕСКОЕ ОПРЕДЕЛЕНИЕ ФЕНОЛОВ В ПОВЕРХНОСТНЫХ ВОДАХ С ИСПОЛЬЗОВАНИЕМ ПОЛИОКСИЭТИЛЕН БИС АРСЕНАТА

 Current paper is devoted to the determination of phenols in surface waters using the method of gas-liquid chromatography on the nozzle chromatographic columns with different polarities of sorbents, in the capacity of which silicone elastomers, polyethylene glycol with the molecular weight of 1500, and polyoxyethylene bis arsenate obtained by arsenating polyethylene glycol-1500 were studied. It was shown that positional isomers, para - and meta – cresols, which have almost identical boiling points, were separated on polyoxyethylene bis arsenate and on the standard sorbents (SE-30 and PEG-1000) they practically do not separate and come out with a single peak. The logarithmic retention indexes were determined for the analyzed phenols and chromatographic Rorschneider polarity factors on polyoxyethylene bis arsenate, which are extremely high for ethanol (factor y) and are associated with the formation of an intermolecular hydrogen bond in the sorbate-sorbent system. It was found that polyoxyethylene bis arsenate had a linear dependence of the logarithm of the retention time on their boiling point and dipole moments. In the case of dipole moments, there was a deviation from the specified dependence for o-chlorophenol, obviously as a result of a specific substituent effect (ortho effect). Polyoxyethylene bis arsenate was used to determine phenols in the surface waters of the Kuibyshev reservoir. For this purpose, a sample preparation system based on the conversion of phenols into brominated derivatives, which have high volatility and are fairly well analyzed by gas-liquid chromatography, was used. A comparative characteristic of the limit of detection of phenols for flame ionization and thermionic detectors was given. As a result of the determination of phenols in the surface waters of the Kuibyshev reservoir, a high content of phenols was found, which fluctuates during the different seasons of the year.Keywords: Phenols, gas-liquid chromatography, sorbents, sorbates, polarity factors, polyoxyethylene bis arsenates.DOI: http://dx.doi.org/10.15826/analitika.2020.24.4.001 A.V. Taneeva, A.V. Dmitrieva, V.F. Novikov, V.K. IlyinKazan State Power Engineering University,Krasnoselskaya, 51, Kazan, 420066, Russian FederationВ работе рассмотрены вопросы определения фенолов в поверхностных водах с использованием метода газо-жидкостной хроматографии на насадочных хроматографических колонках с различными по полярности сорбентами, в качестве которых исследованы силиконовые эластомеры, полиэтиленгликоль молекулярной массой 1500, а также полиоксиэтилен бис арсенат, полученный путем арсенирования полиэтиленгликоля-1500. Показано, что на полиоксиэтилен бис арсенате разделяются позиционные изомеры, пара- и мета-крезолы, которые имеют практически одинаковые температуры кипения и на стандартных сорбентах (SE-30 и ПЭГ-1000) практически не разделяются и выходят одним пиком. На полиоксиэтилен бис арсенате определены логарифмические индексы удерживания анализируемых фенолов и хроматографические факторы полярности Роршнайдера, которые экстремально высоки для этанола (фактор у), что связывается с образованием межмолекулярной водородной связи в системе сорбат-сорбент. Установлено, что на полиоксиэтилен бис арсенате наблюдается линейная зависимость логарифма времени удерживания от их температуры кипения и дипольных моментов. При этом в случае дипольных моментов наблюдается отклонение от указанной зависимости для о-хлорфенола, очевидно,  в результате специфического эффекта заместителя (орто-эффект). Полиоксиэтилен бис арсенат использовали для определения фенолов в поверхностных водах Куйбышевского водохранилища. С этой целью проводили  пробоподготовку, основанную на переводе фенолов в бромпроизводные, которые обладают высокой летучестью и достаточно хорошо анализируются методом газо-жидкостной хроматографии. Приведена сравнительная характеристика предела обнаружения фенолов для пламенно-ионизационного и термоионного детекторов.  При использовании  разработанной методики анализа поверхностных вод установлено наличие фенолов в бассейне реки Волга, концентрация которых изменяется в различные периоды времени года.Ключевые слова: фенолы, газо-жидкостная хроматография, сорбенты, сорбаты, факторы полярности.DOI: http://dx.doi.org/10.15826/analitika.2020.24.4.00

Measurements of integral muon intensity at large zenith angles

High-statistics data on near-horizontal muons collected with Russian-Italian coordinate detector DECOR are analyzed. Precise measurements of muon angular distributions in zenith angle interval from 60 to 90 degrees have been performed. In total, more than 20 million muons are selected. Dependences of the absolute integral muon intensity on zenith angle for several threshold energies ranging from 1.7 GeV to 7.2 GeV are derived. Results for this region of zenith angles and threshold energies have been obtained for the first time. The dependence of integral intensity on zenith angle and threshold energy is well fitted by a simple analytical formula.Comment: 4 pages, 4 figures, 1 tabl

One-Dimensional Discrete Stark Hamiltonian and Resonance Scattering by Impurities

A one-dimensional discrete Stark Hamiltonian with a continuous electric field is constructed by extension theory methods. In absence of the impurities the model is proved to be exactly solvable, the spectrum is shown to be simple, continuous, filling the real axis; the eigenfunctions, the resolvent and the spectral measure are constructed explicitly. For this (unperturbed) system the resonance spectrum is shown to be empty. The model considering impurity in a single node is also constructed using the operator extension theory methods. The spectral analysis is performed and the dispersion equation for the resolvent singularities is obtained. The resonance spectrum is shown to contain infinite discrete set of resonances. One-to-one correspondence of the constructed Hamiltonian to some Lee-Friedrichs model is established.Comment: 20 pages, Latex, no figure

Assessment of invasive and weed species by hyperspectral imagery in agrocenoses ecosystem

The present study aimed to investigate the possibility of using hyperspectral imaging data to identify the invasive and weed species in agrocenoses ecosyste